Simple Measurement Method Research Articles

Temperature-insensitive bending measurement method using optical fiber sensors

This paper presents a new and simple method for indirect bending measurements. The main advantage of the proposed method is its immunity from temperature as well as electromagnetic interference. It uses small and simple-to-fabricate transducer-based fiber Bragg gratings tilted in the fiber core at a small angle. In this work, analysis of the characteristic changes in the transmission of tilted Bragg gratings with different bending treatments are presented. It is shown that selected areas of the spectrum are more or less sensitive to different fiber curvatures. Additionally, the sensitivity of the method to changes in the polarization angle is presented for selected examples. The division of the complete transmission spectrum into more or less sensitive areas provides a development of output parameter dynamics by improving the usable range. This paper shows the difference between the curvature-dependent transmission spectrum changes for 2-degree and 4-degree tilted gratings. The contour length changes in selected divided ranges of the spectrum have a quasi-linear character, which is promising for applications. The influence of changes in the input light polarization direction on changes in the calculated contour length is also investigated. In three boundary polarization cases, the greatest difference in the normalized contour length for a constant curvature radius is 0.01028, which is 1,028% of the maximum. The results for bending radius measurements based on contour changes are presented for the range from 30 to 12 mm, but the proposed system allows for bending radius measurements over a wider range.

Simple method for frequency response measurement of photodetectors based on wavelength-to-time mapping.

A simple method is proposed for measuring frequency responses of photodetectors (PDs) based on wavelength-to-time mapping in this paper. The proposed method is an all-optical scheme, which is simple, fast, accurate and free from any extra calibration. Optical pulses emitted from a mode-locked laser are firstly pre-chirped by a spool of dispersive compensation fiber. In this way, the frequency spectrum of the pulses is mapped into time domain. Then, the pre-chirped pulses beat with a reference continuous wave laser with a fixed wavelength in the PD under test and generate a linearly chirped microwave signal. The frequency response information of the PD can be decoded by analyzing the generated linearly chirped microwave signal. Experimental results show that the frequency response of the PD with 3-dB bandwidth of ∼15GHz has been accurately measured with a resolution of ∼390MHz. The measurement result agrees well with the one measured by the commercial lightwave component analyzer.

Determining Crispness Level of Dry Food through Its Compressive Strain Energy

Crispness is the most appealing characteristic of dry food products. However, the term crispness has different subjective meaning among consumers. This study aims to quantitatively measure the crispness of potato crisp by performing compression test on a single specimen, and analyzing the compressive behavior, i.e., compressive strain energy. The crispness of the specimens were differentiated by changing the moisture exposure durations, which are 0, 1, 2, 3, 6 hours, in a room and ambient condition. The measured load and displacement data were transformed into stress and strain curves. The strain energy for every 1% strain increment was calculated and investigated to determine the crispness. The crispness difference among specimens of 0, 3, and 6 hours groups was significantly perceived at 8% of strain. It was revealed that the 3 and 6 hours of room air exposure could decrease the crispness by 17% and 45%, respectively. This suggests the compressive strain energy at a certain strain can be an indicator of crispness. This experimental study is expected to evolve food engineering by proposing a simple yet precise crispness measurement method for dry food.

720 CONVENTIONAL AND SIMPLE METHODS OF MEASURING MEAN NOCTURNAL BASELINE IMPEDANCE SHOW EXCELLENT AGREEMENT

Abstract Mean nocturnal baseline impedance (MNBI) is a measurement that shows promise in investigating reflux disease by reflecting esophageal mucosal integrity. The conventional method of measuring MNBI is time-consuming and operator-dependent. A new, simple method of measuring MNBI has been suggested. This study aimed to report MNBI measurements by both conventional and simple methods in a cohort of laryngopharyngeal reflux (LPR) and gastro-esophageal reflux disease (GERD) patients to validate the simple measurement method. Methods 187 patients were divided into LPR (n = 105) or GERD (n = 82) groups by predominant symptom profile, and underwent off-therapy impedance-pH monitoring. MNBI was blindly measured by both conventional and simple methods, and values were correlated. Bland–Altman plots were constructed to assess mean differences and to identify bias between the two measurement methods. Results For the two measurement methods, mean difference in the distal esophagus was −89 (±328) ohms, in the proximal esophagus was −6 (±653) ohms, and in the pharynx was 128 (±577) ohms. There was strong correlation between conventional and simple MNBI values, with r = 0.940 in the distal esophagus, r = 0.463 in the proximal esophagus, and r = 0.712 in the pharynx (all p < 0.001). Conclusion There was excellent agreement between conventional and simple methods of measuring MNBI, with no evidence of proportional bias. Conventional and simple MNBI values correlated excellently in the distal esophagus, and moderately well in the proximal esophagus and pharynx. This study supports the use of the simple method of measuring MNBI to enhance diagnosis of reflux disease.

A simple fiber length measurement method with improved accuracy using microwave photonic technology

A simple fiber length measurement method with improved accuracy using microwave photonic technology

Low thermal conductivity measurement using thermoelectric technology - Mathematical modeling and experimental analysis

This study presents a simple, inexpensive and new method for the thermal conductivity measurement of low thermal conductivity materials using thermoelectric technology. The proposed system consists of a thermoelectric cooler, a thermoelectric generator and two heat sinks cooled with two fans. To measure the thermal conductivity, a sample is placed between a thermoelectric cooler and a thermoelectric generator. The heat generated on the hot side of the thermoelectric cooler passes through the sample and enters the thermoelectric generator makes a temperature difference between its two sides. The temperature difference produces an electrical voltage which is a function of the thermal conductivity, thickness of the sample and the power consumption of the thermoelectric cooler. As a result, a mathematical modeling was used to obtain a nonlinear function for estimation of the thermal conductivity as a function of produced electrical voltage, thickness of the sample, electrical voltage and electrical current of the thermoelectric cooler. The proposed method evaluated by testing several materials with known thermal conductivity (0.02 W.m−1. K−1 - 0.05 W.m−1. K−1) and the results showed a good agreement (maximum error of 10%) between the reference values and the experimental data. The measuring time of the system is considerably short and it only took 12 min. Repeatability of the measurement method for different materials showed that the rate of change is between 0.5% - 6%. A linear correlation for thermal conductivity estimation of Polystyrene with density of 8.0 Kg.m−3 to 25 Kg.m−3 has been proposed with a maximum error of 7%. Another linear correlation has been proposed for thermal conductivity estimation of other materials (0.02 W. m−1. K−1 to 0.05 W. m−1. K−1) with a maximum error of 10%.

Low-effort determination of heat capacity and thermal conductivity for cylindrical 18650 and 21700 lithium-ion cells

High-fidelity simulations of lithium-ion cells describing fast charging or safety-critical events often rely on precise thermal parameters. Usually, the determination of cell parameters such as heat capacity or thermal conductivity is time consuming and cost intensive. To streamline this process, a simple yet precise measurement method for determining the specific heat capacity of lithium-ion cells is now extended by an approach that also captures their thermal conductivity. The method presented here was developed using two cylindrical cell formats, each containing a lithium–nickel–manganese–cobalt-oxide (NMC) cathode and a silicon-graphite anode. The extension is based on a two-dimensional finite element (FEM) model, whose geometry is parameterized by computed tomography (CT) scans. To ensure the simplicity of the experimental evaluation, the FEM model is approximated by a rational function. The new measurement method is applied at three different temperatures and states of charge (SOC). The results show that while the specific heat capacity of the jelly roll increases with temperature by 0.2%/K for both cell formats, it is only minimally influenced by the SOC. In contrast, the through-plane thermal conductivity of the electrode-separator-composite decreases by -0.5%/K and is enhanced by up to 9% by increasing the SOC in a window ranging from 10% to 71%.

Coexistence of volatile and non-volatile resistive switching in Ni/SiO2/Pt memristor device controlled from different current compliances

We fabricated a Ni/SiO2/Pt resistive random-access memory device referred to as a memristor, which demonstrates both volatile and non-volatile switching. A reversible transition between volatile and non-volatile switching is achieved by applying different current compliances (CCs). Volatile switching was observed when the CC is 50 nA, whereas volatile switching changed to non-volatile switching when the CC is 100 nA. The switching mechanism model can be explained by the formation and rupture of conducting filaments by electrochemical metallization effects, which are vital in resistive switching. We demonstrate a simple pulse measurement method for both switching behaviors. In a single Ni/SiO2/Pt memristor device, short-term memory for volatile switching and a long-term memory synaptic function for non-volatile switching is observed under repeated stimuli. Owing to the distinctive characteristics of the Ni/SiO2/Pt device, the short-term synaptic function, i.e. paired-pulse facilitation and depression for volatile switching, is successfully mimicked by the memristor. These electrical results indicate that the Ni/SiO2/Pt memristor device with synaptic behavior has potential for use in brain-inspired computing systems.

Simultaneous Determination of Aerosol Inorganic and Organic Nitrogen by Thermal Evolution and Chemiluminescence Detection.

Inorganic nitrogen (IN) and organic nitrogen (ON) molecules constitute a significant part of atmospheric aerosol. Unlike IN, the total ON quantity remains largely unquantified due to a lack of a simple and direct measurement method. This analytical deficiency hinders the quantitative assessment of the various environmental and health effect impacts by aerosol ON. In this work, we developed an analyzer system that utilizes programmed thermal evolution of carbonaceous and nitrogenous aerosols and chemiluminescence detection coupled with the multivariate curve resolution data treatment to achieve simultaneous quantification of IN and ON. The system is capable of detecting IN and ON as low as 96 ng N per sample on a small filter aliquot (1 cm2) without any pretreatment. This method breakthrough opens the door to quantifying an important pool of aerosol N that was analytically inaccessible in the past and holds the promise to quantifying IN and ON in other environmental samples. As a demonstration, quantification of aerosol ON at an urban site in Hong Kong, China, in samples spanning over a year reveals ON constituting a significant fraction (9-52%) of the total aerosol nitrogen and having major source origins in both secondary formation and primary emissions.

A high sensitivity LC-MS/MS method for measurement of 3-methoxytyramine in plasma and associations between 3-methoxytyramine, metanephrines, and dopamine

IntroductionDiagnosis of pheochromocytoma and paraganglioma (PPGL) is aided by the measurement of metanephrine (MN) and normetanephrine (NMN). Research suggests that 3-methoxytyramine (3MT), a dopamine (DA) metabolite, may serve as a biomarker of metastasis in patients with paraganglioma. Considering the very low endogenous plasma 3MT concentrations (<0.1 nM), highly sensitive and specific methods for 3MT are needed. MethodsWe developed a simple method for measurement of 3MT. Sample preparation was performed using solid phase micro-extraction with the eluates injected directly onto the LC-MS/MS. Data acquisition was performed in multiple reaction monitoring mode with an instrumental analysis time of 3 min per sample. We evaluated the method’s performance and analyzed samples from healthy individuals and pathological specimens. ResultsThe limit of quantitation and upper limit of linearity were 0.03 nM and 20 nM, respectively. The intra-/inter-day imprecision for pooled plasma samples at concentrations of 0.04 nM, 0.2 nM, and 2 nM was 10.7%/18.3%, 4.5%/8.9%, and 3.1%/0.9%, respectively. Among samples with MN, NMN, or both MN and NMN above the reference intervals (RIs), 0%, 16% and 46%, respectively, showed 3MT greater than the proposed upper RI value of 0.1 nM; 12% of samples with DA above the RI had 3MT above 0.1 nM. ConclusionsThe developed method allowed accurate quantitation of 3MT in patient samples and would provide valuable information to clinicians diagnosing or monitoring patients with PPGL. High 3MT concentrations in patient samples with MN and NMN within the respective RIs may alert clinicians of the possibility of a DA-producing tumor.

Office hysteroscopic morcellation service: Evaluation of women experience and factors affecting satisfaction

ObjectivesTo evaluate the hysteroscopic morcellation service in office-setting in everyday practice outside the context of clinical trials. The primary objectives were to assess level of acceptability and factors affecting women satisfaction. The secondary objectives included assessment of complete resection rate, complications rate, pain score during the procedure and on discharge, and the correlation between the lesion size as subjectively estimated by the hysteroscopists versus the volume of morcellated tissues as semi-quantitively measured by the laboratory. MethodThe clinical data was compiled for 287 consecutive women undergoing hysteroscopic morcellation in office-setting from 1 January 2017 to 31 March 2021 in a teaching hospital in the UK. A questionnaire, formulated on the Visual Analogue Scale (VAS), was completed immediately after the procedure by the last 110 women undergoing the procedure. ResultsThe mean age of the cohort (n = 278) was 54.5 years (SD ± 12.5). Only 7 (2.4%) women required two-stage procedure because of size (fibroid ≥ 4 cm), vascularity or multiplicity of lesions. No complications were encountered. The majority of women completing the questionnaire (n = 110) found office procedure acceptable (105, 95.5%, VAS ≥ 7), were willing to have it again if indicated (102, 92.7%, VAS ≥ 7), would recommend it to family and friends (105, 95.5%, VAS ≥ 7) and confirmed receiving adequate preoperative information by doctors and nurses (107, 97.3%, VAS ≥ 7). The level of preoperative explanation and information-giving showed significant (p < 0.01) positive correlation with the level of acceptability and recommendation to others and significant (p = .007) negative correlation with the pain experienced on discharge. The median (IQR) estimated size at hysteroscopy was 2 cm (1–6 cm) for polyps and 2.5 cm (1–4 cm) for fibroid. The median (IQR) volume of the morcellated specimens as estimated by laboratory was 2000 mm3 (1100–3800 mm3). The estimated size at hysteroscopy was positively correlated with the specimen’s volume (Spearman’s rho (r) = 0.31, 95% = CI, 0.14–0.45, p < 0.01). ConclusionOffice hysteroscopic morcellation is associated with high satisfaction rate and low pain score on discharge. Good preoperative explanation and information-giving was the crucial factor that increased women satisfaction. Subjective estimation of lesion size by hysteroscopists may be an accurate and simple method of measurement.

Investigation on Mullins effect of rubber materials by spherical indentation method>

Rubber-like soft materials usually experience load-induced softening behavior called the Mullins effect, in which the preloaded material exhibits a significantly more compliant response than the virgin material. However, rare quantitative and simple method of characterizing Mullins effect can be founded and corresponding accurate simulations in practice were severely restricted. In this paper, a simple measurement method was developed to characterize this mechanical response. A comprehensive theoretical, computational, and experimental study of the spherical indentation of rubber materials was undertaken to interpret parameters of the Mullins effect. Neo-Hookean model is used to describe nonlinear hyper-elastic deformation behavior and a pseudo-elastic model originally proposed by Ogden and Roxburgh is applied to interpret load-induced softening effects. Relationships between indentation loads, indentation depths, radius of the spherical indenter, and constitutive parameters of the material are obtained by dimensional analysis. Based on finite-element methods and parameter optimization procedure, a general method for determining the parameters of neo-Hookean and pseudo-elastic models was established. The approach was numerically and experimentally validated. This method provides a simple and accurate way of interpreting load-induced softening of rubber materials from spherical indentation tests, which will enrich the application of pseudo-elastic model using in vary cyclic loading conditions, capturing more new features in rubber-like soft materials and structures.

A virtual-electric-field-based method for distributing sampling points on the free-form surfaces of parts

The sampling process used for on-machine inspections is one of the key factors affecting the efficiency and quality of such inspections. For high-precision contact measurements in particular, a good distribution of sampling points can reduce the time spent on the inspection process and improve the reliability of the test results. However, in practice, most production and test equipment can only provide simple measurement methods and insufficient test functions, resulting in reduced automation of the test process and poor-quality test results when testing complex part surfaces. In this paper, we propose a sampling point distribution method for on-machine inspection based on a virtual electric field, to solve the common problem of unreasonable inspection methods and the need to improve efficiency and quality when inspecting free-form surfaces during on-machine inspection. First, the discrete curvature of each node in the grid model is calculated according to Gauss–Bonnet’s discrete curvature formula, which is used as the original data for the subsequent analysis process. The corresponding spatial search sphere is then constructed in the space where the model is located, and based on this, we propose a search method for extreme curvatures on the model surface. A virtual-electric-field model of the part surface is then constructed, and the searched curvature extremes are used to determine the positive charge of an electrostatic field on the model’s surface. The sampling points are regarded as charged particles, and the repulsion equation between sampling points is given. We then analyze the motion law of the sampling points in the electronic potential field within the sampling region, and also give the step length of each motion iteration process. Finally, the adaptive distribution of the sampling points is experimentally verified using several mechanical models with complex surfaces. The results show that the sampling distribution method proposed in this paper outperforms some traditional or commonly used distribution methods in terms of fitting accuracy.

Evaluation of thermal resistance for metalized ceramic substrates using a microheater chip

AbstractThermal dissipation performance is one of the key technologies in designing power modules because their output power and power density have been increasing year by year. Metalized ceramic substrates are generally used as an insulating material in high output power modules. Designing a proper module structure requires not only each material property but also understanding of the heat transfer in a module structure. An accurate measurement method of precise thermal properties for such metallized ceramic substrates is currently still missing. We had developed a new and simple measurement method for evaluating the heat releasing performance of metallized ceramic substrates in a mounted state. In this investigation, the thermal resistance of several kinds of Cu‐metalized ceramic substrates bearing an SiC microheater chip was evaluated. Si3N4 with thermal conductivity, k, of 90 W/(m·K), AlN with k of 180 W/(m·K), and Al2O3 with k of 30 W/(m·K) were employed. In all cases, the measured thermal resistance had an excellent accuracy within an error range of a few percent. In addition, it was revealed that the measured values had good agreement with the estimated values by finite element method (FEM) analyses.

A field‐friendly method of measuring faecal glucocorticoid metabolite concentration as a simple stress checker in snow leopards

Abstract The hormonal analysis of excrement has been employed to non‐invasively assess the physiological conditions of domestic, experimental, zoo and wild animals to. However, conventional hormone analysis techniques require frozen and refrigerated reagents, and laboratory equipment; therefore, it is almost impossible to obtain the results on‐site. This study attempted to establish a method for the simple and rapid quantitative on‐site analysis of faecal glucocorticoid metabolite (fGM) concentrations; this method involved using hand‐shaking for faecal hormone extraction, and immunochromatography using test strips and a smartphone application. This study focused specifically on snow leopards and developed a new, simple fGM measurement method to evaluate their stress levels on‐site. First, the effects of ultraviolet exposure and bacterial activity on fGM concentration, including sample age, were evaluated using faeces from a captive snow leopard. Second, a field‐friendly hormone extraction method was evaluated; this method does not require storage of faeces in the field because the hormones are extracted by hand‐shaking of faeces in ethanol at the time of collection. In addition, to measure hormone concentrations on‐site, a simple immunochromatography measurement kit was used. The concentrations were measured by quantifying the colour reactions using a smartphone application. There was no consistent increase or decrease in fGM concentration with ultraviolet irradiation time. In addition, a high correlation was observed between concentrations extracted using the conventional method (using a vortex mixer and methanol extraction) and those from the field‐friendly method (r = 0.812, p &lt; 0.05). Changes in fGM concentration measured using immunochromatography were also highly consistent with those measured using the conventional method (enzyme immunoassay; r = 0.825, p &lt; 0.05). The analytical validation of immunochromatography also showed high accuracy, that is parallelism (ANCOVA: F = 0.597, df = 1, p = 0.445) and recovery tests (98.2% ± 5.1% and 107.5% ± 18.7%). Further, for biological validation, the change in fGM concentration was examined before and after the transportation of the snow leopards to another zoo. This field‐friendly hormone analysis method is expected to contribute as a simple and rapid stress evaluation tool to manage conservation and animal welfare by monitoring the stress levels.

Conventional and simple methods of measuring esophageal nocturnal baseline impedance show excellent agreement.

Mean nocturnal baseline impedance (MNBI) shows promise in investigating reflux disease by reflecting esophageal mucosal integrity. This study aimed to measure MNBI by both conventional and simple methods in patients with laryngopharyngeal reflux (LPR) and gastroesophageal reflux disease (GERD) in order to evaluate the efficacy of the simple measurement method. Altogether 187 patients were divided into LPR (n=105) or GERD (n=82) groups according to their predominant symptom profile, and underwent off-therapy impedance-pH monitoring. MNBI was measured by both the conventional and simple methods. The Bland-Altman plots were constructed to assess mean differences and to identify bias in the two measurement methods. For the two measurement methods, mean difference was (-89 ± 328) Ω in the distal esophagus, (-6 ± 653) Ω in the proximal esophagus, and (128 ± 577) Ω in the pharynx, respectively. There was a strong correlation between conventional and simple MNBI values, with the coefficient of 0.940 in the distal esophagus, 0.463 in the proximal esophagus, and 0.712 in the pharynx (all P < 0.001). There was an excellent agreement between the conventional and simple methods of MNBI measurement, with no evidence of proportional bias. Conventional and simple MNBI values correlated excellently in the distal esophagus and moderately well in the proximal esophagus and pharynx. This study supports the use of the simple method of measuring MNBI to enhance diagnoses of reflux disease.

Detection of Unbalanced Voltage Cells in Series-connected Lithium-ion Batteries Using Single-frequency Electrochemical Impedance Spectroscopy

For a battery module where single cells are connected in series, the single cells should each have a similar state of charge (SOC) to prevent them from being exposed to an overcharge or over-discharge during charge–discharge cycling. To detect the existence of unbalanced SOC cells in a battery module, we propose a simple measurement method using a single-frequency response of electrochemical impedance spectroscopy (EIS). For a commercially available graphite/nickel-cobalt-aluminum-oxide lithium-ion cell, the cell impedance increases significantly below SOC20%, while the impedance in the medium SOC region (SOC20%–SOC80%) remains low with only minor changes. This impedance behavior is mostly due to the elementary processes of cathode reactions in the cell. Among the impedance values (Z, Z′, Z″), the imaginary component of Z″ regarding cathode reactions changes heavily as a function of SOC, in particular, when the EIS measurement is performed around 0.1 Hz. Thanks to the significant difference in the time constant of cathode reactions between ≤SOC10% and ≥SOC20%, a single-frequency EIS measurement enlarges the difference in impedance between balanced and unbalanced cells in the module and facilitates an ~80% improvement in the detection signal compared to results with conventional EIS measurements.

Deterministic generation of high-dimensional entanglement between distant atomic memories via multiphoton exchange

Promising access to high-speed quantum networks relies on the creation of high-dimensional entangled memories that provide quantum communication with higher capacity of noisy quantum channels, thereby reducing the transmission time of information. Yet, the distribution of multidimensional entanglement between remote memory nodes is still faintly investigated. We propose an experimentally feasible protocol of deterministic generation of high-dimensional entanglement between distant multilevel atoms confined in high-finesse optical cavities and driven by laser pulses. Three-dimensional entanglement is generated deterministically between remote atoms by triggering a two-photon wave packet, which mediates a superposition of states chosen by the laser pulse parameters. The efficient transfer of atomic states between remote nodes allows the construction of a three-dimensional quantum repeater, where the successful creation of entanglement can be verified by a simple method for reliable measurement of atomic ground Zeeman states.

Capture and recognition of interfacial waves in annular flow based on image analysis technology

<p indent=0mm>Annular flow is often encountered in many industrial applications, which features a circumferential liquid film at the pipe wall and a continuous gas core with entrained droplets in the tube center. One of the most remarkable features of annular flow is the distribution of various scales of interfacial waves in wavelength and amplitude on the liquid film. It is generally known that the generation, movement, and breakup of interfacial waves play an essential role in the heat and mass transfer in annular flow. Thus, complete knowledge of the interfacial waves is of great importance for the characterization of mass, momentum and energy exchange process of the unit process and the system. So far, extensive research has been carried out to investigate the characteristics of interfacial waves. There are two major groups of measurement methods for the capture of the interfacial waves, i.e., the contact measurement method and the non-contact measurement method. The conductivity probe is widely used as a typical contact measurement method to investigate the properties of the interfacial waves. However, it is only suitable for local measurement of the conductive liquid film, and the measured liquid film thickness is the average of the thickness of the liquid film around the probe. It is also worth noting that the accuracy of the probe is restricted to the interference to the flow field, the rod-climbing effect of the fluids, the aging of the probe, and the deposition of impurities. The laser-induced fluorescence technology has become one of the most promising non-contact measurement methods due to its high temporal and spatial resolution and fast response speed. However, strict optical environmental conditions, complex and expensive test systems limit its wide application. Therefore, it is important to develop a simple and economical non-contact measurement method to capture and identify interfacial waves. As a common optical measurement method, high-speed photography technology is often employed to analyze the macroscopic characteristics of flow patterns and their transitions. Due to the superimposition, absorption, and separation of the interfacial waves during their movement, it is almost impossible to extract and distinguish waves from the original images. In the present study, a delicate approach for interfacial wave capture and recognition is developed through analyzing the temporal and spatial evolution of liquid film thickness in the annular flow. According to the difference in size and life span, three main types of interfacial waves are recognized as ripples, disturbance wave, and huge wave in gas-liquid two-phase flow. Compared with the laser-induced fluorescence technology, the proposed image processing method is qualitatively demonstrated to have effective identification abilities. Additionally, the velocity and frequency of the disturbance waves are obtained for quantitative verification. Compared with the experimental data in the literature, the proposed wave capture method is proved to implement a high resolution tracking for the interfacial wave at the millisecond time scale and micron level. Although the proposed image processing method offers a relative dearth of detailed information about interfacial waves compared with the laser-induced fluorescence technology, it provides a simple operation and non-contact measurement for interfacial waves in annular flow.

A simple method for dimensional measurement of ring-shaped objects using image processing technique

A simple method for dimensional measurement of ring-shaped objects using image processing technique