Calibration Tests Research Articles

Calibration test method of capacitance sensor for multiple degrees of freedom based on inertial sensor

Calibration test method of capacitance sensor for multiple degrees of freedom based on inertial sensor

SMART SAFETY HELMET: PENDETEKSI KARBON MONOKSIDA (CO) DI LOKASI PENGGALIAN SUMUR DAN PERTAMBANGAN

The well excavation or drainage process often results in casualties due to the presence of poison gas at the bottom of the well. Workplace accidents caused by toxic gases in mining locations also frequently loss of life. This research aims to create a smart safety helmet, a project helmet for personal protection equipped with an MQ-2 sensor to detect toxic gases, connected to a smartphone application using IoT (Internet of Things) technology. Data collection involves calibration tests and simulation tests. Data analysis employs descriptive statistical analysis in the form of numbers and tables. The creation of the smart safety helmet involves integrating Arduino devices with an MQ-2 sensor, LCD, buzzer, power bank, and IoT technology connected to the mobile phones of operators or project supervisors. This integration enables the helmet to detect and relay information about CO gas and its safety status. Based on the performance test results and calibration tests using Automotive Diagnostic Solutions owned by the Cilacap District Transportation Agency, the smart safety helmet has been proven effective in detecting the presence of carbon monoxide by being worn by mining workers and well diggers, thus detecting CO levels and its safety status. If the CO level reaches 1500 ppm or more, the operator or project manager can immediately prepare rescue measures.

Comparative Study between Thermo-Mechanical and Inherent Strain Method in Analysing Part Distortion of WAAM Component Using Numerical Simulation

This research investigates the part distortion of WAAM process by utilizing advanced numerical simulation. The WAAM component is made of a stainless steel SS316L deposition layer that is deposited on top of a mild steel S235 substrate plate to create a hollow, rectangular structure with a thin wall. In this study, Goldak's double-ellipsoid was used as the heat source model, and an isotropic hardening rule based on the von-Mises yield criterion was used. MSC Marc/Mentat is utilized as the numerical FE software for this research. The commercial S235 mild steel for substrate and the evolved SS316L was scanned by JMATPRO as the input for material modelling. In order to reduce the computational time of the numerical WAAM process, an Inherent Strain Method (ISM) is proposed for a numerical WAAM simulation in Marc. There are two ISM methods proposed for this study, the first is the analytical ISM based on the calculations and second is the calibration-based ISM using Virtual Calibration Test (VCT). On obtaining the ISM value based on the result of VCT, the mathematical software MATLAB were utilized to find the optimized ISM value. This research has a final purpose to determine which numerical simulation model that has a clear advantage on predicting the component deformation result in term of result accuracy as well as computational time. The expected final outcome of this study is the implementation of ISM method on numerical WAAM simulation is able to predict a part distortion in an accurate manner similar to TMM model with significantly faster computational time. Keywords: WAAM, Part Distortion, Numerical Simulation, Inherent Strain Method, Computational Time.

Derivation and Validation of a Scoring System for Predicting Poor Outcome After Posterior Circulation Ischemic Stroke in China.

Guidelines for posterior circulation ischemic stroke (PCIS) treatment are lacking and outcome prediction is crucial for patients and clinicians. We aimed to develop and validate a prognostic score to predict the poor outcome for patients with PCIS. The score was developed from a prospective derivation cohort named the Third China National Stroke Registry (August 2015-March 2018) and validated in a spatiotemporal independent validation cohort (December 2017-March 2023) in China. Patients with PCIS with acute infarctions defined as hyperintense lesions on diffusion-weighted imaging were included in this study. The poor outcome was measured as modified Rankin scale (mRS) score 3-6 at 3 months after PCIS. Multivariable logistic regression analysis was used to identify predictors for poor outcome. The prognostic score, namely PCIS Outcome Score (PCISOS), was developed by assigning points to variables based on their relative β-coefficients in the logistic model. The PCISOS was derived from 3,294 patients (median age 62 [interquartile range (IQR) 55-70] years; 2,250 [68.3%] men) and validated in 501 patients (median age 61 [IQR 53-68] years; 404 [80.6%] men). Among them, 384 (11.7%) and 64 (12.8%) had poor outcome 3 months after stroke in respective cohorts. Age, mRS before admission, NIH Stroke Scale on admission, ischemic stroke history, infarction distribution, basilar artery, and posterior cerebral artery stenosis or occlusion were identified as independent predictors for poor outcome and included in PCISOS. This easy-to-use integer scoring system identified a marked risk gradient between 4 risk groups. PCISOS performed better than previous scores, with an excellent discrimination (C statistic) of 0.80 (95% CI 0.77-0.83) in the derivation cohort and 0.81 (95% CI 0.77-0.84) in the validation cohort. Calibration test showed high agreement between the predicted and observed outcomes in both cohorts. PCISOS can be applied for patients with PCIS with acute infarctions to predict functional outcome at 3 months post-PCIS. This simple tool helps clinicians to identify patients with PCIS with higher risk of poor outcome and provides reliable outcome expectations for patients. This information might be used for personalized rehabilitation plan and patient selection for future clinical trials to reduce disability and mortality.

Numerical simulation method of seed pelletizing: Increasing seed size by powder adhesion

Seed pelletizing can effectively increase the seed size. However, observing the microscopic process of seed pelletizing using physical tests is challenging. This study used the discrete element method (DEM) to simulate the process. Discrete elemental simulation models and contact parameters of seed and powder had been determined by particle scaling theory and parameter calibration tests, respectively. The contact model (modified model) between the seed and powder was established, which could effectively characterize the effect of the water addition on the viscosity. The seed pelletizing numerical simulation test was carried out with the average number of contact particles as the main evaluation index. The results showed that the amount of powder adhering to the surface of individual seeds was 43. Bench test results show that the quality of pelletized seeds met relevant criteria. KeywordsDiscrete element method (DEM)Numerical simulationSeed pelletizingContact modelRepose angle

Development and external validation of a head and neck cancer risk prediction model.

Head and neck cancer (HNC) incidence is on the rise, often diagnosed at late stage and associated with poor prognoses. Risk prediction tools have a potential role in prevention and early detection. The IARC-ARCAGE European case-control study was used as the model development dataset. A clinical HNC risk prediction model using behavioral and demographic predictors was developed via multivariable logistic regression analyses. The model was then externally validated in the UK Biobank cohort. Model performance was tested using discrimination and calibration metrics. 1926 HNC cases and 2043 controls were used for the development of the model. The development dataset model including sociodemographic, smoking, and alcohol variables had moderate discrimination, with an area under curve (AUC) value of 0.75 (95% CI, 0.74-0.77); the calibration slope (0.75) and tests were suggestive of good calibration. 384 616 UK Biobank participants (with 1177 HNC cases) were available for external validation of the model. Upon external validation, the model had an AUC of 0.62 (95% CI, 0.61-0.64). We developed and externally validated a HNC risk prediction model using the ARCAGE and UK Biobank studies, respectively. This model had moderate performance in the development population and acceptable performance in the validation dataset. Demographics and risk behaviors are strong predictors of HNC, and this model may be a helpful tool in primary dental care settings to promote prevention and determine recall intervals for dental examination. Future addition of HPV serology or genetic factors could further enhance individual risk prediction.

Dual-luminophore pressure-sensitive paint measurement using three-gate lifetime method with photodegradation correction.

In this paper, we propose a photodegradation correction method for the dual-luminophore pressure-sensitive paint (PSP) measurement using lifetime-based imaging, which was proposed for correction of the temperature-induced error but has suffered from photodegradation in the previous studies. We introduced a parameter that characterizes the photodegradation of a dual-luminophore PSP as the intensity ratio between the two luminophores. The changes in the calibration coefficients for the pressure and the temperature due to photodegradation were corrected based on this parameter. In this study, a coupon-based calibration test was performed, and the luminescence characteristics of the dual-luminophore PSP including photodegradation were investigated. Then, the proposed method was applied to a coupon-based validation test and a jet impingement test, and the effectiveness of the method was evaluated by comparing results with and without correction. The pressure measurement accuracy was significantly improved by photodegradation correction.

The cumulative plastic deformation demand for buckling restrained braces imposed by the strong motions in the 2023 Türkiye earthquake sequence

The Türkiye earthquake sequence on February 6, 2023, was featured by the closely located earthquake doublet of Mw 7.8 and Mw 7.5. The consequent strong ground motions are supposed to be able to impose high demands on the ultra-low-cycle fatigue performance of metallic dampers in buildings, including the widely used buckling restrained braces. This study evaluates the cumulative plastic deformation (CPD) demands on buckling-restrained braces (BRBs) in multi-story buildings imposed by the strong ground motions in the 2023 Türkiye earthquake doublet. Thirty-two records of the highest peak ground accelerations were selected from the strong motion database. Among them, eight captured the ground motions during both events, and the rest only captured the shaking of either of the events. The CPD demands on the BRBs in reinforced concrete frames with various fundamental periods, brace-to-frame stiffness ratios, and BRB ductility ratio are calculated by nonlinear time history analyses and are summarized in the form of enveloped spectra of CPD ratios at constant ductility. The results show that the CPD demands on BRBs increase with smaller brace-to-frame stiffness ratios and larger BRB ductility ratios. The enveloped CPD demands are several hundreds of times the nominal yield deformation of the BRB, which are much higher than the CPD demands for the calibration tests of BRBs stipulated by AISC 341 in the US.

Development of Sign Language Interpreter Glove for Speech-Impaired Deaf Individuals with Levenshtein Algorithm as an Autotext Correction System.

Assistive technology is technology developed in the form of aids, adaptive tools, and rehabilitation for individuals with disabilities to compensate for their lacking abilities. With assistive technology available to people with special needs, it can help them enhance their independent living skills and reduce their dependence on others, including in communication activities. This research aims to assess the feasibility of developing assistive technology for the speech-impaired, specifically a glove that can translate the SIBI letter sequence into words displayed on a 6 x 12 LCD screen and also produce sound output from the sign language hand movements of speech-impaired individuals when using the glove. The research method used in this study is Research and Development (R&D). The calibration test phase indicated that the prototype was in good condition, as evidenced by an accuracy rate above 90% for voltage at 0◦ and 90◦ angles produced by each finger. Consequently, the next calibration phase, which involves translating sensor readings into SIBI letters through digital data values, can be carried out by taking the ADC values of each finger. Subsequently, the glove was tested to read 7 out of 20 alphabets and achieved a success rate of ≥ 90% for 5 alphabets. The lowest success rate was 70% for the letter E. The average success rate for the 7 alphabet experiments was 91.4%. In the field test phase, the glove was tested on a deaf-mute student to form several words, and the output text displayed on the LCD and audio output matched the readings corrected by the auto-text correction system.

Calibration and metrological test of the RadonEye Plus2 electronic monitor

Consumer-grade electronic radon monitors are increasingly utilized by users and researchers. Fast and cost-effective procedures for their metrological assurance are necessary. The metrological characteristics of 20 RadonEye Plus2 monitors were investigated. The new monitors had low background of 2.5 ± 0.5 Bq/m3. The precision error for the studied group was estimated at about 9 % and the biased error (accuracy) ranged from 3 % to 16 % for activities in the range 280–2900 Bq/m3. An excellent linearity of all monitors was observed in this range. The statistical fluctuations of the RadonEye Plus2 at 300 Bq/m3 were estimated at 9% (relative percent error).A simplified calibration procedure was successfully applied. The exposure was at activity concentration exponentially increasing with a small rate, being almost constant within a single measurement of the RadonEyes. The correction factors obtained with this procedure are in excellent agreement with those obtained through the standard procedure with exposure at different constant radon concentrations. The correction factors of the monitors ranged from 0.70 to 1.06 with an average of 0.880 and a standard deviation of 0.079. Overall, the results show that the metrological characteristics of RadonEye Plus2 are sufficient for measurements in dwellings and workplaces. However, the spread of their correction factors highlights the importance of individual calibration when measurements are made for research, legislation compliance tests or decision making.

Passive Wireless Partial Discharge Sensors with Multiple Resonances.

Partial discharge (PD) is the dominant insulating defect in Gas-Insulated Switchgear (GIS). The existing detection methods are mainly divided into built-in wire-connected disk antennas with destructive drilling and external ultra-high frequency antennas with poor anti-interference ability. This research introduces a passive wireless PD sensor implanted inside GIS on the observation window. The sensor is implemented by a sheeting branch-inductor with multiple resonances which is able to enhance detection sensitivity. A coaxially aligned readout circuit, positioned outside the GIS, interrogates the PD sensor to wirelessly obtain the PD signal. The proposed sensing scheme improves signal-to-noise ratio and ensures minimal disruption to the electric field distribution inside GIS. An experimental setup was established in a controlled laboratory environment to benchmark the multi-resonant sensor against the commercial UHF sensor. A 2.5-times enhancement of signal strength was observed. Since our sensor was implanted inside the GIS, a high signal-to-noise ratio (68.82 dB) was obtained. Moreover, we constructed a wireless calibration test to investigate the accuracy of the proposed sensor. The precision of the signal test was as high as 0.72 pC. The pulse phase distribution information was collected to demonstrate a phase-resolved partial discharge (PRPD) pattern. The experiment results validate the effectiveness of the proposed method and demonstrate excellent performance in PD detection.

A nomogram to predict mortality in patients with severe fever with thrombocytopenia syndrome

Severe fever with thrombocytopenia syndrome (SFTS) is an acute infectious disease caused by a novel Bunyavirus infection with low population immunity and high mortality rate. Lacking specific therapies, the treatment measures vary with the severity of the disease, therefore, a case control study involved 394 SFTS patients was taken to determine risk factors for mortality. Comparative clinical data from the first 24 h after admission was collected through the electronic medical record system. Independent risk factors for death of SFTS were identified through univariate and multivariate binary logistic regression analyses. The results of the logistic regression were visualized using a nomogram which was created by downloading RMS package in the R program. In our study, four independent mortality risk factors were identified: advanced age(mean 70.45 ± 7.76 years), MODS, elevated APTT, and D-dimer. The AUC of the nomogram was 0.873 (0.832, 0.915), and the model passes the calibration test namely Unreliability test with P = 0.958, showing that the model's predictive ability is excellent. The nomogram to determine the risk of death in SFTS efficiently provide a basis for clinical decision-making for treatment.

Characterisation of the neutron sources in use at STUK SSDL through a new transfer instrument with spectrometric capabilities

Characterising neutron sources for calibration or generic testing purposes is a complex task, as the neutron spectrum may depend, to some extent, on the construction characteristics of the source. Bonner spheres (BS) are the traditional spectrometric transfer instruments, but they are very sensitive to room scatter and required measurements are highly time consuming. The recently developed NCT-WES device, belonging to the family of the Single Moderator Neutron Spectrometers, has been proposed as a convenient alternative to BS. This work presents the results of a demonstration campaign organised at the STUK neutron metrology laboratory (Finland) in July 2023, where the spectra from two 252Cf and two 241Am-Be sources were determined. For the 241Am-Be sources, the results were compared to the spectra of two categories recently introduced by ISO 8529-1. Based on the results it was concluded that the “large” source category is an appropriate selection for STUK sources. The campaign also proved the operational advantages of NCT-WES as spectrometric transfer instrument.

Abstract PO5-07-02: AI-assisted interpretation of PD-L1 CPS improves the precision medicine in Triple-negative breast cancer

Abstract Objective: The IMpassion 031 and KEYNOTE-355 clinical trial demonstrated the advantages of atezolizumab and pembrolizumab in the treatment of Triple-negative breast cancer (TNBC). However, the application of CPS in assessing PD-L1 expression is challenging. Pathologists have great variability in interpretation of PD-L1 CPS, the daily diagnostic workload is too heavy and their diagnostic efficiency is low, and they still have deficiencies in terms of accurate enumeration. It is of necessity to establish an objective and effective method which is highly repeatable. Methods: In this study, we established a deep learning-based artificial intelligence-assisted (AI-assisted) model which using cell detection and region segmentation algorithm. Three rounds of ring studies (RSs) were conducted. 12 pathologists of different level evaluate the CPS of PD-L1 (DAKO 22C3) in TNBC patients by visual assessment and AI-assisted model. Compare the difference, consistency and accuracy of the interpretation. Our research evaluated PD-L1 CPS expression with continuous score. Shapiro-Wilk (S-W) method performs normality test, difference analysis using Friedman M and Bonferroni calibration tests, consistency analysis is studied by intraclass correlation coefficient (ICC) and heat maps and box plots. Results: In the visual assessment, the interpretation results of PD-L1 (DAKO 22C3) CPS in different level pathologists have significant differences (P < 0.05), and the consistency of all the pathologists interpretation results was weak. Due to this strong inconsistency, it may result in a number of patients losing the opportunity to use ICIs for treatment. Moreover, the internal consistency of all pathologists in the visual assessment is moderate, in which the repeatability of junior pathologists is the worst, the ICC value is 0.664 (95%CI: 0.564-0.762). Through AI-assisted interpretation, there is no significant difference between all pathologists (P = 0.425), and the ICC value increased to 0.883 (95%CI:0.836-0.922) which improved the consistency of the interpretation results. In addition, through AI-assisted interpretation, the repeatability and accuracy of the interpretation results has been further upgraded. At the same time, the acceptance of AI results by junior pathologists are high, and 80% of the AI results are accepted. Conclusions: With the help of the AI-assisted diagnostic model, different levels of all the pathologists have achieved excellent consistency and repeatability in the interpretation of PD-L1 (DAKO 22C3) CPS. Moreover, the level of interpretation has been sought the rapid enhancement. It can be seen that AI-assisted diagnostic model provides a good approach to strengthen the consistency and repeatability in clinical practice. Our research also shows that PD-L1 CPS can receive precise interpretation from pathologists, so more patients have the opportunity to use ICIs. Therefore, these patients can benefit from treatment and achieve better survival. The interpretation results and system diagram of PD-L1 CPS by AI-assisted model. The consistency and repeatability of the interpretation results. (A)-(C) The consistency of the PD-L1 CPS interpretation among the different level of pathologists in three ring studies. (D)The repeatability of the interpretation results between 12 pathologists in RS1 and RS2. Accuracies and acceptance rates of different experienced pathologists. (A) Boxplots of scoring accuracies for pathologists in different levels. (B) Acceptance rates of all pathologists in total 50 slides. (C) Percent stacked column chart of different levels of pathologists with AI score acceptance. Citation Format: Jinze Li, Xinran Wang, Yueping Liu. AI-assisted interpretation of PD-L1 CPS improves the precision medicine in Triple-negative breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-07-02.

Methodological aspects of using NIR spectroscopy to assess biochemical indicators in barley grain

Background. The possibility of applying near-infrared reflectance (NIR) spectroscopy for rapid assessment of various biochemical parameters in barley varieties and forms is discussed. The data obtained by the Biochemistry and Molecular Biology Department of VIR served to construct calibration models for the content of protein, starch, oil, beta-glucans, and total phenolic compounds (PhC) in grain, facilitating further screening of various barley samples.Materials and methods. The chemical composition of grain was studied in naked and covered spring barley (Hordeum vulgare L.) accessions grown in 2022 in the northwest of Russia. Calibration models were developed to measure the content of protein, oil, starch, beta-glucans, and PhC (80 accessions) in barley grain with the Matrix-I IR analyzer (Bruker Optics, Germany). The models were constructed on the basis of the data obtained by conventional techniques of chemical analysis. The protein/ nitrogen content was assessed using the Kjeldahl method, oil according to the method of defatted dry residue modified by S. V. Ruszkovsky, starch by the polarimetric method according to Evers, beta-glucans by gravimetric analysis, and the total PhC content by the Folin–Ciocâlteu method modified by Singleton and Rossi.Results. Statistical significance of the constructed calibration tests was compared with the results of measuring protein, starch, oil, beta-glucan and PhC levels by chemical methods. It was shown that the data of calibration techniques for protein and starch were significant, while the remaining models required improvement.Conclusion. The proposed method helps to preserve valuable source material, increases labor efficiency, and does not require chemical reagents. Scanning each sample makes it possible to obtain data for several indicators at once, with a specified replication and standard deviation.

Investigating the influence of excitation force on compaction behavior of gravel in granular blends through DEM simulation

During the construction of subgrades, the compaction of granular blends is typically achieved through vibrational techniques at varying the frequencies and excitation forces. This study investigates the impact of excitation forces, within the range of 300-600 kPa, on subgrade compaction by employing the discrete element method (DEM). Calibration tests were conducted to establish the contact parameters for the DEM models, and their reliability was verified via vibration compaction tests. The research further explores the evolution of settlement, particle motion, and contact interactions at both macroscopic and mesoscopic levels as influenced by the excitation forces. Furthermore, the influence of excitation force on the stability of skeleton frameworks was analyzed. The results indicated that the number of contacts in the final state increased consistently with the excitation force, leading to a more uniform distribution. This change contributes to a time-dependent stability within the skeleton framework, which effectively limits the movement of fine particles in the final stages and diminishes the sliding between the coarse particles. Conversely, in the initial phases, a rise in excitation force increases the stress concentration between the contacts, which increases the sliding damage to the skeleton frameworks and leads to greater compaction deformation.

Dynamic modeling of minimum mass of pore-gas for triggering landslide in stable gentle soil slope

This paper presents a dynamic modeling method to test and examine the minimum mass of pressurized pore-gas for triggering landslides in stable gentle soil slopes. A stable gentle soil slope model is constructed with a dry cement powder core, a saturated clay middle layer, and a dry sand upper layer. The test injects H2O2 solution into the cement core to produce new pore-gas. The model test includes three identical H2O2 injections. The small mass of generated oxygen gas (0.07% of slope soil mass and landslide body) from the first injection can build sufficient pore-gas pressure to cause soil upheaval and slide. Meanwhile, despite the first injection causing leak paths in the clay layer, the generated small mass of gas from the second and third injections can further trigger the landslide. A dynamic theoretical analysis of the slope failure is carried out and the required minimum pore-gas pressure for the landslide is calculated. The mass and pressure of generated gas in the model test are also estimated based on the calibration test for oxygen generation from H2O2 solution in cement powder. The results indicate that the minimum mass of the generated gas for triggering the landslide is 2 ppm to 0.07% of the landslide body. Furthermore, the small mass of gas can provide sufficient pressure to cause soil upheaval and soil sliding in dynamic analysis.

The neck structure design of vehicle crash finite element dummy model

Anthropomorphic Test Devices (ATDs) with high biofidelity and compatibility play a crucial role in vehicle safety. This study focuses on enhancing the neck of Hybrid III finite element model by optimising its design and material. The improved Hybrid III model (IH3) is validated through neck calibration tests. Comparing to experimental results,IH3 has a peak torque error of only 1.00% and 5.11%and a 60.04% improvement in calculation efficiency. Then MLH3 with low stiffness and equivalent muscles and ligaments is designed and tested. The results of MLH3 show higher biofidelity than l than Hybrid III. Finally, both IH3 and MLH3 have been tested in a 100% frontal rigid barrier test, with IH3 showing significant accuracy and computational efficiency, indicating that it could replace the current Hybrid III neck for simulation analysis. MLH3 has potential engineering application value in the future, as it improves upon the limitations of the Hybrid III neck’s biofidelity and more closely resembles the real human neck.

Improvement and optimization of coal dust concentration detection technology: Based on the 3σ criterion and the kalman filtering composite algorithm

Due to the inherent time delay in dust concentration data transmission, dust reduction equipment is unable to respond according to the current moment's dust concentration. Hence, the focus of mine dust concentration detection technology extends beyond the current dust concentration to accurately predicting the next moment's dust concentration, allowing a response window for dust reduction equipment, leading to more optimal dust reduction effects. This necessitates the introduction of the Kalman filtering algorithm. Despite the traditional single Kalman filtering algorithm's ability to make certain dust concentration predictions, it is constrained by high-temperature, high-humidity underground environments and electromagnetic pulse signal interference from fan and coal mining machine operations, with an error rate reaching up to 40 %, seriously disrupting underground dust reduction equipment. However, the composite Kalman filtering algorithm incorporating the 3σ rule effectively eliminates bad values and removes instability from the underground environment and noise, rendering it applicable to most complex environments, providing accurate predicted concentrations for dust reduction equipment, and boosting overall universality. This study designed a fusion algorithm based on the Pauta criterion and Kalman filter to further optimize the dust concentration detection technology based on electrostatic induction. The sensor's model and measuring principle were first analyzed, and the initial calibration and precision testing of the sensor using the experimental system were completed. The dust concentration fluctuation characteristics were then modeled with Matlab, and the noise variance was estimated to process and filter the dust concentration data with the Pauta criterion, Kalman filter, and fusion algorithm respectively. The accuracy of the dust concentration sensor was tested again after applying the fusion algorithm, which proved to significantly enhance the stability and accuracy of the electrostatic induction-based dust concentration sensor. This study has critical implications for coal mine dust concentration monitoring and coal miner occupational health protection.

A silicone rubber packaged distributed optical fiber sensing tape for strain-crack monitoring based on OFDR technique

A novel silicone rubber (SR)-packaged distributed optical fiber sensor (DOFS) tape based on optical frequency domain reflectometry (OFDR) technique was developed to effectively monitor substrate cracking. The analytical strain distribution of this sensor tape is derived based on the current strain transfer model and then used to determine the parameter sensitivity to provide a scientific basis for the selection of packing parameters and bond length. A calibration test of the sensor tape on steel plates was performed, and the feasibility of the sensing tape for accurately measuring the substrate strain and crack width was demonstrated. A test is conducted to monitor adjacent double cracks, and the test results show that the sensor tape has the ability to identify crack positions with crack spacings greater than 40 mm. The sensor tape is applied to the monitoring of concrete cracking induced by corrosion, and the test results demonstrate that the DOFS sensing tape has advantages for monitoring large cracks. Both the analytical and experimental results show that the novel SR-packaged DOFS tape is effective and feasible.