Usefulness and limitations of various detector systems for estimation of131I thyroid activity following an RN event.

Following a radiological or nuclear (RN) event, rapid measurement of131I in members of the public is of utmost importance, and much equipment is needed for a high throughput. In this study, three gamma cameras, two thyroid uptake meters and one whole-body counter were calibrated for activity measurements of131I in the thyroid. Minimum detectable activity was derived for the gamma cameras, the thyroid uptake meters and the whole-body counter giving that a committed effective dose (CED) in the interval 2.0-85 µSv, 13-700 µSv and 0.52-6.4 µSv, and thyroid absorbed doses in the interval 0.075-2.1 mGy, 0.48-17 mGy, and 0.020-0.15 mGy, respectively, can be assessed for children, adolescents, and adults. These numbers are based on 10-min measurement, performed at 1, 3 and 7 days after intake, and the CED includes intake by ingestion and inhalation of aerosols Type F, with an activity median aerodynamic diameter (AMAD) of 1 µm. For a fractional signal loss of 63% due to dead time, a CED up to 2.0, 84 and 3.6 Sv and thyroid absorbed dose up to 47 Gy, 2000 Gy and 88 Gy for the three systems, respectively, can be assessed for children and intake by ingestion as a worst-case scenario in terms of CED, measured 7 days after intake. This study demonstrates the potential and limitations of using equipment readily available at larger hospitals for estimation of131I content in thyroid, which could increase the measurement capability following an RN event. .

Antidoping 2.0: Is Adding Power-Output Data to the Antidoping Pool the Next Step? Experts' Viewpoint.

BACKGROUND: Efforts are needed to improve antidoping procedures. The widespread use of power meters among cyclists could help in this regard. However, controversy exists on whether performance monitoring through power-output data could be of help for antidoping purposes. PURPOSE: The objective of the present study was to provide insight into the feasibility and utility of implementing power-based performance monitoring in elite cycling. An expert panel of 15 applied sport scientists and professional cycling coaches were asked for their opinions and perspectives on incorporating power data into the antidoping risk-assessment process. RESULTS: Two different viewpoints were identified from the responses provided by the experts. Some believed that power monitoring could be implemented as an antidoping tool, provided that several surmountable challenges are first addressed. These authors provided suggestions related to the potential practical implementation of such measures. Others, on the contrary, believed that power meters lack sufficient reliability and suggest that the professional cycling world presents conflicts of interest that make this intervention impossible to implement nowadays. CONCLUSIONS: The debate around the utility of power-meter data in the antidoping fight has been ongoing for more than a decade. According to the opinions provided by the experts' panel, there is still no consensus on the real utility and practical implementation of this intervention.

Individualized selection of recent glucose monitoring devices for self-management based on competitive features.

Objective: Goal of the study was to systematically review competitive advantages of medical devices for glucose monitoring in diabetic patients. Method: The review is done systematically according to SALSA criteria and PRISMA guidelines. The search for eligible articles was held from February 16th 2023 to March 1st 2023 in Russian and English languages. The results were synthesized narratively, tabularly, and visually. The search was conducted in the following databases of scientific literature: PubMed, IEEE Xplore, Google Scholar, CyberLeninka, and eLibrary. Results: Twenty-two out of fifty-two manuscripts met the inclusion criteria. The most promising and advantageous characteristics of the evaluated devices, as identified by researchers, include the following: the capability for noninvasive examination; features that facilitate use by patients with fine motor, hearing, and visual impairments; add-ons and software designed to improve patient compliance, including in pediatric populations; and device attributes that enhance the speed and accuracy of analysis while being free of iatrogenic effects. Conclusions: With increasing prevalence of diabetes, glycemic control is crucial for preventing complications. The market offers numerous glucose monitoring devices (GMDs) with varying features, making selection challenging. Our study systematically categorized the strengths of each GMD model for diabetic patients, aiding informed device selection.

Who engages in electricity conservation and to what effect after real-world, high-resolution feedback? An empirical analysis of Korean households with smart meters.

Engagement with households to fully realize the potential of demand-side solutions has attracted policy attention. The potential of feedback has been understudied, especially regarding who engages more in electricity conservation. Furthermore, most studies have been limited to the Western context, with only a few that explore Asia. This study fills these gaps by investigating changes in household hourly electricity consumption patterns after its members receive high-resolution feedback. After data balancing, we partitioned 63 households into distinct groups using K-means clustering and investigated consumption changes after the provision of high-resolution electricity feedback through a mobile application. The results indicate mixed effectiveness of feedback: some households reduced consumption by about 13 %, while others increased it between 7 % and 20 %. In addition, statistical analysis using survey responses revealed that households with greater awareness of electricity costs and a stronger interest in climate change were more receptive to feedback. Demographic and housing attributes such as age, building type, and floor count also influenced the feedback effect. The findings recommend enhancing awareness of electricity costs and climate change and developing a better understanding of individuals' challenges with changing conservation behaviors based on their demographic and housing characteristics.

Exploring the Relationships Between Clinical Examination Findings, Subjective Reported Symptoms and Objective Nasal Patency Measures in Nasal Obstruction: A Baseline NAIROS Sub-Study Analysis.

BACKGROUND: The role of objective nasal airflow measures using peak nasal inspiratory flow (PNIF) and rhinospirometry in supporting clinical examination findings when offering patients septoplasty remain undefined. OBJECTIVE: To explore the baseline relationships between clinical examination findings, subjective reported symptoms and objective nasal patency measures in nasal obstruction. METHODS: This is a sub-study of the NAIROS trial. Participants with nasal obstruction secondary to septal deviation were included in this NAIROS sub-study. The side of septal deviation, enlargement of inferior turbinate (IT), the need for IT reduction if septoplasty was being performed, the area of septum deflecting into the airway and observer rated airway block (ORAB-arbitrarily divided by <50% and >50% blockage) were assessed by clinicians. The subjective score of nasal obstruction was assessed using the Double Ordinal Assessed Subjective Scale (DOASS). Objective nasal patency measures (e.g., nasal partitioning ratio, [NPR] and PNIF) were measured using PNIF and rhinospirometry. RESULTS: The mean NPR for left-sided, both-sided and right-sided septal deviation was -0.35, -0.02 and 0.51, respectively (p < 0.001). There was very weak correlation between the requirement for IT reduction and PNIF change (0.13, p < 0.01). There was no difference in mean PNIF (94 L/min vs. 93 L/min) and mean DOASS (0.33 vs. 0.38) for participants with ORAB rated <50% and >50%. The mean NPR for participants with ORAB >50% was higher than for those with ORAB <50% (0.51 vs. 0.41, p = 0.002). There was strong correlation between the DOASS and NPR (+0.737, p < 0.001). The mean DOASS score for right-sided, both-sided and left-sided septal deviation was 0.32, 0.05 and -0.29, respectively (p < 0.001). CONCLUSION: This study identified strong relationships between the clinician rated side of septal deflection, the patient reported DOASS and the objective NPR measurements. NPR and the clinician rated degree of airway blockage were concordant.

Potential use of Six Sigma metrics in the quality control review of hospital glucose meters.

Background and aim: This study applied Six Sigma metrics to facilitate the quality control (QC) review for hospital glucose meters. Materials and methods: QC data from a period of six months on all hospital glucose meters were extracted from the data management system. Sigma values for each meter at two QC levels were calculated and evaluated each month by combining the imprecision, the absolute bias between the meter mean and all-meter mean, and the standards from ISO 15179:2013. The effectiveness of using Sigma values in identifying meters with possible quality problems for further Levey-Jennings QC chart review was assessed. Results: More than 80 % of the meter's Sigma values within the six months were greater than 4 at either QC level. At the high QC level, twice as many Sigma values were below 4 than the low QC level. Including Sigma values 4, 3.5 or 3 in the criteria for the QC review reduced the number of chart review to 32.8 %, 11.2 % or 3.5 %, respectively. Conclusions: The majority of the glucose meters examined in this study demonstrated optimal Sigma values. The Sigma metrics-based approach could be a valuable tool to guide an effective QC review of glucose meters for quality improvement.

Blood bank quality control: pH assessment methods in platelet concentrates.

Platelet concentrates undergo progressive changes during storage, such as a decrease in pH. Additionally, pH and lactate production showed the strongest correlation with platelet survival in posttransfusion viability studies. pH measurement is a straightforward method for evaluating the quality control of blood components in blood bank practice. Our aim was to compare three pH assessment methods for canine platelet concentrates. The pH values of the canine platelet concentrates were assessed on the first day of storage using a calibrated pH meter, a portable gas analyzer and pH-indicator strips. The results from the pH meter and portable gas analyzer measurements were similar. The pH indicator strips presented higher average values compared to the other more reliable methods evaluated, which could result in the use of inadequate blood components. In conclusion, it is recommended to implement pH measurements using a pH meter for quality control in veterinary blood banks.

Gel instillation sonohysterography (GIS) using Endosgel versus ExEmgel, comparison of pain and image quality and cost benefit analysis: A double blind randomised controlled trial. GISPAIN trial.

INTRODUCTION: Pain experience, physical reaction, image quality and adverse events during Gel Instillation Sonohysterography (GIS) can differ using gels with different compositions. As a result, patient satisfaction can also be affected. The effect of two instillation gels, Endosgel versus ExEmgel, using both the Visual Analogue Scale (VAS) and a Continuous Pain Score Meter (CPSM) was therefore compared. METHODS: This single centre double blind randomised controlled trial included 80 women planned for outpatient GIS, diagnosed with abnormal intrauterine bleeding or fertility disorders and suspicion on an intrauterine abnormality. Patients were randomly allocated to the instillation of Endosgel containing chlorhexidine or ExEmgel without chlorhexidine. Primary outcome was reported pain during the procedure using VAS. Secondary outcomes included pain score measured using CPSM, satisfaction to the procedure and preference at 3 weeks and 3 months after the procedure and image quality. A cost benefit analysis was also performed. RESULTS: The reported median VAS concerning pain during gel instillation was comparable in the Endosgel and ExEmgel group, 2.50 (IQR 0.00-5.00) and 2.00 (IQR 0.00-5.75) respectively (p = 0.69). The median VAS of the entire procedure was also similar: both 2.00 (IQR 0.00-5.00) (p = 0.86). CPSM-scores were not significantly different either. Both groups were similar in image quality (p = 0.83) and patient's satisfaction (p = 0.36). CONCLUSION: Concerning the pain experienced during a GIS procedure and patients' satisfaction, the ExEmgel was not proven to be superior to the Endosgel. Our advice is to use the gel that is available at the lowest costs, as the image quality is the same for both Endosgel and ExEmgel.

Bottle-in-bottle reaction device: Portable gas pressure meter for rapid and on-site analysis of oxalate in spinach and tea beverages.

A gas pressure meter-based portable/miniaturized analytical kit was established for rapid and on-site detection of oxalate. Potassium permanganate (KMnO4) and oxalate solution were mixed together in bottle-in-bottle reaction device, a simple oxidation reaction process occurred within 6 min and carbon dioxide (CO2) was generated, inducing the pressure of the sealed bottle changed, which was measured by a portable gas pressure meter. A detectable range of 0.1-6 µmol mL-1 and a detection limit of 0.064 µmol mL-1 were achieved. The proposed analytical method was further used for the analysis of several real samples (spinach, beverages and water samples), with the recoveries of 89-111%. Considering the interferences from the complicated matrix, calcium chloride (CaCl2) was served as a precipitant, oxalate (C2O4 2-) was precipitated with Ca2+ to form precipitation (CaC2O4), CaC2O4 was then separated from the matrix by centrifuge/filter, eliminating the interferences. It is a rapid, easy-used and interference-free analytical system/device for oxalate on-site and real time analysis.

Wind and mini-hydraulic energy potential in the lower basins of the rivers of the mountain ranges, given their topology.

This document intends to auscultate the potential wind and mini-hydraulic energy in the lower basins of the rivers of the mountain ranges; given its topology, taking as an example the lower basin of the Ocoña river in Arequipa Peru, characterized by the canyoning of the mountain range, from the coast (0 masl) to the highlands (4,500 masl), and by the important flow hydraulic when descending from the highlands to the Pacific Ocean, in an area of 16,045 km2. For this, the wind speed has been recorded in anemometers placed at 6, 12, and 18 m above the surface. The section of the river and its speed have also been determined, the height of the river's water level has been recorded; all with an hourly periodicity. With this information we have determined the potential for wind and mini-hydro energy in this characteristic place. Wind speeds in the order of 10 m/s have been obtained, with a persistence of 8 h a day. As for the mini-hydraulic, with a minimum flow of 50 m3/s there is a persistence greater than 90 %. In conclusion, the potential of wind, mini-hydro, and combined energy of the place is sufficient to satisfy various energy demands, from very small to very large.

Pseudo-Spectral Spatial Feature Extraction and Enhanced Fusion Image for Efficient Meter-Sized Lunar Impact Crater Automatic Detection in Digital Orthophoto Map.

Impact craters are crucial for our understanding of planetary resources, geological ages, and the history of evolution. We designed a novel pseudo-spectral spatial feature extraction and enhanced fusion (PSEF) method with the YOLO network to address the problems encountered during the detection of the numerous and densely distributed meter-sized impact craters on the lunar surface. The illumination incidence edge features, isotropic edge features, and eigen frequency features are extracted by Sobel filtering, LoG filtering, and frequency domain bandpass filtering, respectively. Then, the PSEF images are created by pseudo-spectral spatial techniques to preserve additional details from the original DOM data. Moreover, we conducted experiments using the DES method to optimize the post-processing parameters of the models, thereby determining the parameter ranges for practical deployment. Compared with the Basal model, the PSEF model exhibited superior performance, as indicated by multiple measurement metrics, including the precision, recall, F1-score, mAP, and robustness, etc. Additionally, a statistical analysis of the error metrics of the predicted bounding boxes shows that the PSEF model performance is excellent in predicting the size, shape, and location of impact craters. These advancements offer a more accurate and consistent method to detect the meter-sized craters on planetary surfaces, providing crucial support for the exploration and study of celestial bodies in our solar system.

Evaluation of the Reliability of the CCM-300 Chlorophyll Content Meter in Measuring Chlorophyll Content for Various Plant Functional Types.

Chlorophyll fluorescence is a well-established method to estimate chlorophyll content in leaves. A popular fluorescence-based meter, the Opti-Sciences CCM-300 Chlorophyll Content Meter (CCM-300), utilizes the fluorescence ratio F735/F700 and equations derived from experiments using broadleaf species to provide a direct, rapid estimate of chlorophyll content used for many applications. We sought to quantify the performance of the CCM-300 relative to more intensive methods, both across plant functional types and years of use. We linked CCM-300 measurements of broadleaf, conifer, and graminoid samples in 2018 and 2019 to high-performance liquid chromatography (HPLC) and/or spectrophotometric (Spec) analysis of the same leaves. We observed a significant difference between the CCM-300 and HPLC/Spec, but not between HPLC and Spec. In comparison to HPLC, the CCM-300 performed better for broadleaves (r = 0.55, RMSE = 154.76) than conifers (r = 0.52, RMSE = 171.16) and graminoids (r = 0.32, RMSE = 127.12). We observed a slight deterioration in meter performance between years, potentially due to meter calibration. Our results show that the CCM-300 is reliable to demonstrate coarse variations in chlorophyll but may be limited for cross-plant functional type studies and comparisons across years.

Pointer Meter Reading Method Based on YOLOv8 and Improved LinkNet.

In order to improve the reading efficiency of pointer meter, this paper proposes a reading method based on LinkNet. Firstly, the meter dial area is detected using YOLOv8. Subsequently, the detected images are fed into the improved LinkNet segmentation network. In this network, we replace traditional convolution with partial convolution, which reduces the number of model parameters while ensuring accuracy is not affected. Remove one pair of encoding and decoding modules to further compress the model size. In the feature fusion part of the model, the CBAM (Convolutional Block Attention Module) attention module is added and the direct summing operation is replaced by the AFF (Attention Feature Fusion) module, which enhances the feature extraction capability of the model for the segmented target. In the subsequent rotation correction section, this paper effectively addresses the issue of inaccurate prediction by CNN networks for axisymmetric images within the 0-360° range, by dividing the rotation angle prediction into classification and regression steps. It ensures that the final reading part receives the correct angle of image input, thereby improving the accuracy of the overall reading algorithm. The final experimental results indicate that our proposed reading method has a mean absolute error of 0.20 and a frame rate of 15.

Exploring Cognitive Impairments Associated with Primary Open-Angle Glaucoma and Exfoliation Glaucoma.

This study explored the link between different types of glaucoma and cognitive function in a cohort of 620 Japanese patients. Participants were categorized into primary open-angle glaucoma (PG), exfoliation glaucoma (EG), and non-glaucomatous control groups. The findings revealed a significant decline in cognitive function as indicated by the Mini-Cog test in the EG group (mean ± SD: 4.0 ± 1, 95% CI: 3.9 to 4.2) compared to the PG group (4.4 ± 0.1, 4.3 to 4.5, p < 0.0001). Levels of fingertip measured advanced glycation end-products (AGEs) were significantly higher in the EG group (mean ± SD: 0.45 ± 0.006, 95% CI: 0.44 to 0.46) compared to the PG group (0.43 ± 0.004, 0.42 to 0.44, p = 0.0014). Although the multivariate analysis initially showed no direct association between glaucoma types and Mini-Cog scores, the EG group exhibited higher age and intraocular pressure (IOP) compared to the PG group. Further analysis revealed that high levels of AGEs were associated with cognitive decline and decreased mean visual fields in the EG group. Age was identified as a cofounding factor in these associations. An inverse correlation was observed between the accumulation of AGEs and skin carotenoid levels. Early detection of cognitive decline in glaucoma patients could enable timely intervention to preserve visual fields. Fingertip measurements of skin carotenoids and AGEs offer promising potential as non-invasive, straightforward diagnostic tools that could be widely adopted for monitoring ophthalmic and cognitive health in glaucoma patients.

Functionalized primer initiated signal cycles and personal glucose meter for sensitive and portable miRNA analysis.

MicroRNA (miRNA) has garnered considerable attention due to its diagnostic capabilities, such as in hypoxic cognitive impairment and cancers. However, the existing miRNA detection methods are commonly criticized for the drawbacks of low sensitivity and false-positive detection derived from interfering molecules. Here, we provide a novel, sensitive and portable method for miRNA detection by combining target identification based cyclization of padlocks, immobilized primer-based signal amplification and a personal glucose meter. The proposed method exhibits several advantages, including precise identification of specific sites, exceptional sensitivity and instrument-free feature. These attributes hold great promise for the diagnosis and clinical investigation of various diseases, such as cancer and hypoxic cognitive impairment, enabling a deeper understanding of their pathological and physiological aspects.

With miRNA-155 as detective target, the feasibility of the method has been demonstrated. The padlock sequences are cyclized by miRNA-155, which subsequently hybridize with primer sequence that is immobilized on the surface of a 96-well plate, and the interfering molecules are removed. This DNA polymerase triggers a chain extension process on the terminus of primer sequence, activating DNAzyme based cleavage. Consequently, a multitude of linker sequences are generated to facilitate the formation of the 'e/linker/f/sucrase' on magnetic bead, thereby enabling the catalysis of sucrose into glucose. This enzymatic reaction may be identified and measured using the personal glucose meter.

Design, Development and Application of a Modular Electromagnetic Induction (EMI) Sensor for Near-Surface Geophysical Surveys.

Low-frequency electromagnetic induction (EMI) is a non-invasive geophysical method that is based on the induction of electromagnetic (EM) waves into the subsurface to quantify changes in electrical conductivity. In this study, we present an open (design details and software are accessible) and modular system for the collection of EMI data. The instrument proposed allows for the separations between the transmitter to be adjusted and up to four receiving antennas as well as the acquisition frequency (in the range between 3 and 50 kHz) to permit measurements with variable depth of investigation. The sensor provides access to raw data and the software described in this study allows control of the signal processing chain. The design specifications permit apparent conductivity measurements in the range of between 1 mS/m and 1000 mS/m, with a resolution of 1.0 mS/m and with a sampling rate of up to 10 samples per second. The sensor allows for a synchronous acquisition of a time stamp and a location stamp for each data sample. The sensor has a mass of less than 5 kg, is portable and suitable for one-person operation, provides 4 h of operation time on one battery charge, and provides sufficient rigidity for practical field operations.

Physics Constrained High-Precision Data-Driven Modeling for Multi-Path Ultrasonic Flow Meter in Natural Gas Measurement.

Ultrasonic flow meters are crucial measuring instruments in natural gas transportation pipeline scenarios. The collected flow velocity data, along with the operational conditions data, are vital for the analysis of the metering performance of ultrasonic flow meters and analysis of the flow process. In practical applications, high requirements are placed on the modeling accuracy of ultrasonic flow meters. In response, this paper proposes an ultrasonic flow meter modeling method based on a combination of data learning and industrial physics knowledge. This paper builds ultrasonic flow meter flow velocity prediction models under different working conditions, combining pipeline flow field velocity distribution knowledge for data preprocessing and loss function design. By making full use of the characteristics of the physics and data learning, the prediction results are close to the real acoustic path flow velocity distribution; thus, the model has high accuracy and interpretability. Experiments are conducted to prove that the prediction error of the proposed method can be controlled within 1%, which can meet the needs of ultrasonic flow meter modeling and subsequent performance analysis in actual production.

Association between Skin Carotenoid Levels and Cognitive Impairment Screened by Mini-Cog in Patients with Glaucoma.

Carotenoids, having strong antioxidant properties, have been associated with neurodegenerative conditions like dementia and glaucoma, characterized by neuronal loss leading to cognitive and visual dysfunction. Therefore, carotenoids have attracted attention as factors predictive of the onset and progression of these neurodegenerative diseases. However, the impact of carotenoids on cognitive impairment and glaucomatous visual field defects remains unexplored. We conducted a retrospective, observational clinical study to investigate the association between skin carotenoid (SC) levels and cognitive impairment, as screened by the Mini-Cog test, in glaucoma patients. The study included 406 participants and 812 eyes were examined (average age: 69.7 ± 11.4 years; 228 men, 178 women) with various types of glaucoma: primary open angle (57.6%), exfoliation (18.6%), and other types (23.8%). SC levels were estimated via pressure-mediated reflection spectroscopy. Mixed-effects regression models were utilized to examine the relationship between SC levels, visual field defects, and Mini-Cog results. Of the participants, 28 (6.9%) tested positive on the Mini-Cog, suggesting cognitive impairment. The average SC level in the Mini-Cog positive group was significantly lower than in the negative group (269.5 ± 86.4 A.U. vs. 329.2 ± 120.4 A.U., respectively; p = 0.01). Additionally, the visual field mean deviation (MD) in the Mini-Cog positive group was notably worse than that in the negative group (-19.64 ± 9.07 dB vs. -12.46 ± 9.28 dB, respectively; p < 0.0001). The mixed-effects regression analysis revealed a significant association between Mini-Cog positivity and lower SC levels (p = 0.0006), although SC levels did not significantly correlate with MD (p = 0.3). Our findings suggest that cognitive impairment in glaucoma patients is associated with lower SC levels, underscoring the potential benefits of maintaining carotenoid levels to slow cognitive function decline. The protective role of carotenoids in glaucoma merits further investigation.

Blood pH Changes in Dental Pulp of Patients with Pulpitis.

The severity of pulpitis is a crucial factor in determining the suitable treatment. There are no clear objective indicators to assess the stage of pulp inflammation that could be used in clinical practice. The change in blood pH of the pulp during the inflammatory phase could hypothetically serve as an indicator of the pulp inflammation severity. The aim of this study was to assess the pH values in the pulpal blood of mature teeth in patients with symptomatic pulpitis, in comparison with the healthy controls. The study included patients with symptoms of pulpitis in premolar or molar teeth (Test group; n = 24, mean age 36.04, SD 7.10), and healthy controls (Control group, n = 6, mean age 24.5, SD 5.94) referred for extraction of premolars or third molars, for orthodontic reasons. The pulpal blood was taken at the opening of the endodontic access cavity, and the pH value was measured in both groups. Statistical analysis was performed using the SPSS 27.0 program with a significance level of p ≤ 0.05. The Mann-Whitney test for dependent samples was performed to evaluate the statistical difference between the groups. The patients with symptomatic pulpitis had significantly decreased pulpal blood pH compared to the healthy controls (p ≤ 0.05). The mean pulpal blood pH was 7.27 (SD 0.06) and 7.40 (SD 0.02) in Test and Control groups, respectively. In the Test group, the pulpal blood pH values were significantly lower in the patients who had symptoms for 3 days or more (7.25, SD 0.05) than in those who had symptoms for up to 3 days (7.33, SD 0.03) (p < 0.001). The pH value of the pulpal blood gradually declines in cases of symptomatic pulpitis, along with increasing duration of the symptoms.

Characterization of Gas-Liquid Two-Phase Slug Flow Using Distributed Acoustic Sensing in Horizontal Pipes.

This article discusses the use of distributed acoustic sensing (DAS) for monitoring gas-liquid two-phase slug flow in horizontal pipes, using standard telecommunication fiber optics connected to a DAS integrator for data acquisition. The experiments were performed in a 14 m long, 5 cm diameter transparent PVC pipe with a fiber cable helically wrapped around the pipe. Using mineral oil and compressed air, the system captured various flow rates and gas-oil ratios. New algorithms were developed to characterize slug flow using DAS data, including slug frequency, translational velocity, and the lengths of slug body, slug unit, and the liquid film region that had never been discussed previously. This study employed a high-speed camera next to the fiber cable sensing section for validation purposes and achieved a good correlation among the measurements under all conditions tested. Compared to traditional multiphase flow sensors, this technology is non-intrusive and offers continuous, real-time measurement across long distances and in harsh environments, such as subsurface or downhole conditions. It is cost-effective, particularly where multiple measurement points are required. Characterizing slug flow in real time is crucial to many industries that suffer slug-flow-related issues. This research demonstrated the DAS's potential to characterize slug flow quantitively. It will offer the industry a more optimal solution for facility design and operation and ensure safer operational practices.