Portable Measurement Research Articles

An automatic rebar spacing measuring method based on the YOLOv8-GB model

In engineering construction projects, rebar spacing measurement requires significant manual labor with low efficiency. This paper proposes a new intelligent rebar spacing measurement method based on the YOLOv8-GB model to save the workforce and improve efficiency. This method collects images of rebars to be measured using a binocular camera, utilizes the proposed YOLOv8-GB model to extract rebars from the scene, and achieves spacing measurement. The system is deployed on the NVIDIA Jetson TX2 NX for on-site portable measurement and can run in real-time at 24 frames per second. Experimental results show that the improved YOLOv8-GB network, compared with the YOLOv8n network, increased Recall, Precision, mAP@0.5, and mAP50-95 by 0.6 %, 5.5 %, 2.3 %, and 7.6 %, respectively. The measurement system built with YOLOv8-GB achieved an average absolute error of ± 1.7 mm, ±2.1 mm, and ± 2.7 mm for rebar spacing measurements on three different ground textures, with average relative errors of 0.85 %, 0.93 %, and 1.32 %, meeting engineering requirements. Compared to the measurement system built with YOLOv8n, the average absolute error decreased by 37.0 %, 8.0 %, and 25.0 % under the three different ground textures, while the average relative error decreased by 36.1 %, 8.8 %, and 23.7 %, respectively.

Research on ultra-clean micro gas flow calibration technology of passive piston type with sealing

Aiming at the portable measurement and calibration needs of ultra-clean micro gas flow meters in the semiconductor industry, this paper designs an ultra-clean micro gas flow standard device based on passive piston type with sealing. The device adopts a horizontal structure, using the O-ring on the piston for radial sealing, unlike the traditional mercury and gap sealing, this design avoids the stringent requirements for piston speed and clearance. To increase automation of the calibration process, an automatic calibration system is built. Mathematical modeling and 6DOF dynamic mesh analysis are used to ensure that the piston operates at a stable stage. Through the uncertainty analysis, the extended uncertainty of the device reaches 0.21 % (k = 2). The uncertainty was verified by normalizing the deviation En and the results show that it is feasible to trace the clean gas flow rate with the piston standard device.

Establishment of a measuring unit based on Arduino board for recording vibrations on an agricultural tractor during tillage process

When it comes to agricultural tractor ergonomics, vibration is one of the most important factors to consider. However, little research has been done to evaluate this parameter and its impact on workers’ health. Therefore, the aim of this study was to fabricate a portable vibration measurement unit (PVMU) based on an Arduino microcontroller and a vibration sensor (accelerometer ADXL335). The PVMU performance was tested in combination with a commercially available three-axis USB vibration measurement device (VB10). Furthermore, the vibration measurements were used to calculate the tractor driver’s whole-body vibration load according to ISO 2631-1 along three perpendicular axes (X, Y, and Z) during soil tillage using a disk harrow under different tillage speeds of 4.0, 5.5, and 7.0 km/h at a tillage depth of 15 cm in a sandy loam soil. Performance tests of the PVMU and the commercially available three-axis USB vibration meter (VB10) revealed a highly significant level of agreement based on a correlation coefficient of 0.9822. It was found that the vibration level increases with increasing tillage speed. The highest vibration level, 0.80 m/sec2, was observed in the vertical direction (Z-axis) at a tillage speed of 7.0 km/h. The lowest vibration level, 0.12 m/sec2, was observed in the lateral direction (Y-axis) at a tillage speed of 4.0 km/h. The dominant frequency range of vibration transmitted to the tractor seat was found to be between 2.04 Hz and 20.14 Hz. The daily exposure values that is, A (8) determined during this study to assess the health hazards due to vibration for tractor drivers ranged from 0.01 m/sec2 to 0.06 m/sec2 lower than the recommended exposure action value (EAV) limit that is, 0.5 m/sec2. This means that there is no health risk for the driver during the soil tillage using a disk harrow plow. The PVMU proposed in this study is very reliable and can be used as a vibration assessment tool for other agricultural tractor-implement combinations.

Research on impedance measurement based on Gallium Nitride Transistor

Abstract Impedance measurement has broad applications in fields such as electrochemistry, biology, medicine, and food safety. Typically, frequency response analyzers are used for small signal disturbance measurements, but they come with drawbacks such as high cost, large size, and limited excitation capabilities. To address the need for wide-band, large-signal, and portable impedance measurement in electrochemical applications, a novel scheme based on a Gallium Nitride device excitation circuit and amplitude-phase discrimination module is proposed. A multiphase cascade frequency-doubling buck circuit is used to inject disturbance signals into the impedance under test, and impedance parameters are obtained using discrete fourier transformafter signal sampling. By varying the frequency of the disturbance signal, impedance information across different frequencies can be captured. In this approach, the amplitude-phase discrimination module replaces the frequency response analyzer, reducing the overall size of the measurement system, while the power device-based excitation circuit enables large signal disturbances.

Testing the nightmare cognitive arousal processing model.

Posttrauma nightmares are recurring nightmares that begin after a traumatic experience. Research has only recently begun to identify variables that predict posttrauma nightmare occurrences. Research has identified presleep arousal-cognitive (PSA-C) and presleep arousal physiological (PSA-PHYS), sleep onset latency (SOL), and sleep-disordered breathing (SDB) as potential predictors of posttrauma nightmares. However, previous research includes methodological limitations, such as a lack of physiological measures and a homogeneous sample. To replicate previous findings and increase generalizability, the current study investigated predictors of nightmare occurrences in a sample of male inpatient veterans with mixed-trauma history. Participants (n = 15) completed an initial assessment battery and seven consecutive days of pre and postsleep diaries, including measures of posttrauma nightmare triggers and posttrauma nightmare occurrences. Portable objective measurements of sleep and presleep states were used to examine sleep quality and physical arousal. Analyses revealed that PSA-C and SOL both predicted posttrauma nightmare occurrences and that PSA-PHYS was significantly higher on nights when nightmares occurred. Results replicate earlier research which posits that PSA and SOL play a role in triggering the occurrence of posttrauma nightmares. It should be noted that the sample was relatively small, warranting cautious interpretation of results. However, when taken together with the findings of the replicated study, results could suggest the plausibility of therapies targeting presleep cognitions, SOL, and presleep arousal in the treatment of posttrauma nightmares. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

High-performance machine-learning-based calibration of low-cost nitrogen dioxide sensor using environmental parameter differentials and global data scaling

Accurate tracking of harmful gas concentrations is essential to swiftly and effectively execute measures that mitigate the risks linked to air pollution, specifically in reducing its impact on living conditions, the environment, and the economy. One such prevalent pollutant in urban settings is nitrogen dioxide (NO2), generated from the combustion of fossil fuels in car engines, commercial manufacturing, and food processing. Its elevated levels have adverse effects on the human respiratory system, exacerbating asthma and potentially causing various lung diseases. However, precise monitoring of NO2 requires intricate and costly equipment, prompting the need for more affordable yet dependable alternatives. This paper introduces a new method for reliably calibrating cost-effective NO2 sensors by integrating machine learning with neural network surrogates, global data scaling, and an expanded set of correction model inputs. These inputs encompass differentials of environmental parameters (such as temperature, humidity, atmospheric pressure), as well as readings from both primary and supplementary low-cost NO2 detectors. The methodology was showcased using a purpose-built platform housing NO2 and environmental sensors, electronic control units, drivers, and a wireless communication module for data transmission. Comparative experiments utilized NO2 data acquired during a five-month measurement campaign in Gdansk, Poland, from three independent high-precision reference stations, and low-cost sensor data gathered by the portable measurement platforms at the same locations. The numerical experiments have been carried out using several calibration scenarios using various sets of calibration input, as well as enabling/disabling the use of differentials, global data scaling, and NO2 readings from the primary sensor. The results validate the remarkable correction quality, exhibiting a correlation coefficient exceeding 0.9 concerning reference data, with a root mean squared error below 3.2 µg/m3. This level of performance positions the calibrated sensor as a dependable and cost-effective alternative to expensive stationary equipment for NO2 monitoring.

Exploring ultrafine particle emission characteristics from in-use light-duty diesel trucks in China using a portable measurement system

Diesel vehicle exhaust is one of the major contributors to ultrafine particles (UFPs) in urban areas in China. However, there is still a lack of knowledge about UFPs emission characteristics from current in-use diesel vehicles. This study has carried out an on-road test of 10 in-use Light-duty Diesel Trucks (LDDTs) with different emission control standards in China using a self-established portable measurement system based on the Electronic Low-pressure Impactor (ELPI) and characterized the ultrafine particle number (PN) concentration, particle size distribution and metal element contents. The results revealed a significant reduction of 93.37% in the average PN0.1 emission factor of LDDTs from China III to China VI. Notably, LDDTs compliant with the China VI vehicle emission control standard exhibited the lowest PN0.1 and PM0.1 emission factors, measuring 4.991 × 1014 #/km and 0.627 g/km, respectively. By taking into account emissions under real driving conditions, we found that the PN emission rates grow with the increase of the Vehicle Specific Power (VSP). The cold-start phase had higher PN emissions than the hot-start phase, with 8590, 1890, 477, and 22 times higher than those of the ambient air (1.18 × 105 #/cm3), respectively. The installation of Diesel Particulate Filter (DPF) can decrease UFPs by more than 99.8%, while the PN emission factor during the DPF regeneration stage (1.85 × 1016 #/km) increased by 5 orders of magnitude that of the DPF normal works (7.51 × 1011 #/km). Metal element contents analysis shows that Fe, Ca, Al and Mg are the dominant elements in UFPs of LDDT exhaust gas, but the element of Ni is slightly increasing in a China VI, possibly due to the new automotive engine exhaust manifolds being made of Ni instead of cast iron for the purpose of having more high-temperature resistance. Our study demonstrates the importance of monitoring and routine maintenance of exhaust after-treatment systems.

Fluorescence and colorimetric rapiddual-signal "on-off-on" switching detection of ascorbic acidbased on TSPP/DCIP.

Afluorescence and colorimetric dual-signal sensing system for the determination of ascorbic acid (AA) in complex media was developed by using 5,10,15, 20-tetrakis(4-sulfonyl) porphyrin (TSPP) as a sensing probe and sodium 2,6-dichloroindophenol (DCIP) as a bridge. A fluorescence resonance energy transfer (FRET) effect occurred when DCIP was added to the TSPP solution, resulting in the quenching of the fluorescence signal of TSPP and a change in the color of the solution from pink to blue. The DCIP in the system reacted with AA in a redoxreaction to produce colorless phenol imine, the color of the solution changed from blue to green causing an obvious colorimetric response, and the TSPP/DCIP sensing system's fluorescence signal restored owing to AA introduced. The fluorescence method for AAshowed good linearity in the ranges 0.08mM ~ 1mM and 1mM ~ 43.6mM with a detection limit of 6.4μM. And the colorimetric method for AAshowed excellent linearity in the range 0.46mM ~ 40.2mM with a detection limit of 76.0μM. Theconstructed "dual-signal" probe in the study has been successfully applied to the detection of AA in practical samples. The method proposed has great potential for practical applications and provides new ideas for the visual inspection of portable measurements.

Fundamental study on measurement of soil pH and electrical conductivity in batch tests for the determination of soil-soil solution distribution coefficient

Soil-soil solution distribution coefficient, Kd, is used to understand the mobility of radionuclides in the soil environment. Soil pH and electrical conductivity (EC) are the important factors affecting soil Kd, but existing methods for Kd employed different conditions, as well, standard soil pH and EC methods varied in the test conditions. It would be desirable to measure both pH and EC using the same soil solution for Kd with portable meters (non-glass electrode type) that need only a small liquid volume. In this study, at first, we utilized portable pH and EC meters to examine effects of different conditions on measurements, i.e., the water/soil ratios, contact time and standing time. The results showed that portable meter measurements of soil supernatant after 1 h shaking and 1 h standing could provide comparable pH and EC values with other standard soil tests. Then measurements of pH, and EC up to 168 h were carried out, considering the Kd methods for radiocesium (Cs); only slight differences in these values were observed compared to the standard test method. Considering these results, further analysis was carried out on the correlation between soil Kd-Cs and pH and found a clear decrease of Kd-Cs at pH < 5.

Wireless and Portable Electrochemical Measurement System Integrated With Screen-Printed Immunosensor for VP28 Protein Detection

Wireless and Portable Electrochemical Measurement System Integrated With Screen-Printed Immunosensor for VP28 Protein Detection

Respiratory muscle strength and oxygenation as predictors of length of hospital stay in patients with COVID-19

The aim was to analyze the prognostic value of ventilation/ gas exchange dissociation markers to predict the treatment length in patients with the acute phase of COVID-19.Materials and methods: The analysis was performed using a database of 384 randomly selected patients from December 2021 to May 2022 with a confirmed diagnosis of the acute phase of COVID-19, aged 61±16 years. Spirometry of maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) was performed on 2,2±0,2 day of hospitalization with a portable MicroRPM device (CareFusion, UK) and measurement of surrogate oxygenation index (SpO2/FiO2), ROX index (SpO2/ FiO2)/respiratory rate) was carried out in all patients. Log-regression models were used (STATISTICA 10) to determine cutoff values for these functional variables and their ability to predict the patients length of hospital stay from the date of examination (≤ 7 vs &gt; 7 days).Results: The lowest sensitivity (SE) and specificity (SP) were shown in models using only the respiratory muscle strength markers MIP (SE=54%, SP=70%) and MEP (SE=73%, SP=47%), that were the same in the combination of MIP and MEP (SE=65%, SP=58%). The areas under ROC were equal to 0.6 in all three models. The models based on hypoxia markers had a higher classification power (AUC 0,7) compared to the previous three, and the sensitivity value was higher in the model using the ROX index (SE = 58% and SP = 78%), but the specificity was better in the surrogate oxygenation index model (SE = 48% and SP = 88%). A complex model based on a combination of the two integral hypoxia indices, as well as a diaphragm strength marker (SpO2/FiO2+MIP*ROX+MIP) had the best sensitivity (67%) and specificity (84%), and the area under ROC reached 0.8.Conclusion: Indicators of respiratory muscle strength and oxygenation are suitable markers for combined models and algorithms for predicting hospital length of stay in COVID-19 patients.

Emissions of gaseous nitrous acid (HONO) from diesel trucks: Insights from real-driving emission experiments

Nitrous acid (HONO) serves as a substantial contributor in the atmospheric chemistry of hydroxyl radicals (·OH). Despite its significance, the primary sources of atmospheric HONO, particularly diesel truck emissions, have not been thoroughly examined. This study investigated the factors influencing HONO emissions via on-road exhaust emission tests using a self-developed portable measurement system. The findings show that the HONO emissions measured during on-road testing are higher than those measured during chassis dynamometer testing, highlighting the need for on-road tests to capture HONO emissions. Emission standards and truck types greatly influence HONO emission factors (EFs), with stricter regulations leading to lower emissions. The average fuel consumption-based EFs for light-duty diesel trucks ranged from 0.93 g/kg for China III to 0.08 g/kg for China VI. For medium-duty diesel trucks, the EFs decrease from 1.43 g/kg for China III to 0.19 g/kg for China V. Moreover, the vehicle-specific power demonstrated a stronger correlation with HONO emissions. This research showed that HONO emissions were significantly higher without or before the optimal operation of the SCR device, and the device notably reduced HONO emissions. Future research should focus on the impact of various exhaust after-treatment systems and explore HONO conversion mechanisms.

Estimation of efficacy of a home monitoring and communication platform to prevent frailty among older adults in Sweden- a pilot study with a randomized controlled trial design

BackgroundThe aging population of the world is increasing. Aging leads to risks for frailty and other chronic diseases and health systems must focus more on prevention to guarantee healthy aging. The primary objective was to estimate the efficacy of the POSITIVE-(The Maintaining and imPrOving the intrinSIc capaciTy Involving Primary Care and caregiVErs) system in improving frailty during a 6-month follow-up period. MethodA randomized controlled, assessor-blinded pilot study (RCT) with 50 individual < 70 years, pre-frail or frail was recruited from a primary care center in Stockholm Region. All participants received a drug review, nutritional recommendations, and a Vivifrail physical exercise program. In addition, the intervention group received POSITIVE including a tablet, an application, and portable measurement devices. The intervention group was monitored remotely by a primary care nurse at the primary health care centre during a six-month follow-up period. ResultsAt baseline there was a significance between the groups regarding the FTS-5 scale, and significantly more obese participants in the intervention group. The drug reviews showed that three of 43 participants got a review and new diseases were discovered. The test of interactions showed a tendency for significant differences over time between the groups in frailty measured by Fried Frailty Phenotype's and FTS-5 scales. ConclusionFrailty status over time in the intervention group not differed significantly from the controls. Including individuals to the project even through a pandemic showing that the design is possible for future studies to show effects of new ways of preventing frailty at home. Trial RegistrationClinicalTrials.gov. Registration number: NCT04592146. October 19, 2020. https://clinicaltrials.gov/ct2/show/NCT04592146?term=positive&draw=2&rank=7

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.

Physiological characteristics of ornamental caladiums (Caladium x hortulanum Birdsey, Araceae Juss.) through leaf colour diversity

This work aims to analyze the physiological characteristics of caladium ornamental plants with different leaf colors. Ten leaf colors, i.e., dark maroon, maroon, red, pink, white, pinkish young green, yellow, lime green, pinkish dark green, and dark green, were arranged in a completely randomized design and subjected to colorimetric red–green–blue (RGB) and portable photosynthesis measurement. Caladium leaf color, defined by the colorimetric RGB value, significantly impacted leaf physiological properties. Heatmap analysis apparently clustered caladiums into dark-colored group and light-colored ones. Dark-colored caladiums, as indicated by lower RGB values, exhibited higher photosynthesis rate, stomatal conductance, and water use efficiency (WUE). In contrast, light-colored caladium show a higher RGB, leaf temperature and light use efficiency (LUE) than the dark ones. By considering their leaf color-based physiological adaptability, this work recommends moderate sunlight and adequate water conditions for growing light-colored caladiums, while dark caladiums potentially tolerate excess light and water scarcity. Further research, including quantitative pigment analysis, is necessary to verify this hypothesis.

A nanohybrid-based smartphone-compatible high performance electrochemical glucose sensor

A cost-effective and low-potential smartphone-compatible electrochemical sensor was constructed using a nanohybrid for the sensing of glucose in human and animal serum. The nanohybrid composed of gold nanoparticle (GNP) decorated cobalt hexacyanoferrate (CHCF) modified ZIF-67 (cobalt metal organic framework, CMOF) was synthesized and characterized by FTIR, XRD, and SEM with EDX analysis. The electrochemical characteristics of the nanohybrid were investigated by depositing the nanohybrid over a conventional glassy carbon electrode (GCE) and performing cyclic voltammetry, which revealed a stable redox peak with a formal potential of +0.23 V, corresponding to Co2+/3+ redox couple in GNP–CHCF–CMOF. Thus, developed sensor was utilized for the electrochemical glucose detection, which showed exceptional electrocatalytic activity over a linear detection range from 8.33 to 3793 μM with a low detection limit of 0.96 μM at a low potential of +0.35 V. Furthermore, the GNP–CHCF–CMOF/GCE sensor was employed for the detection of glucose spiked in human and rabbit serum samples, which showed excellent recoveries. A portable measurement device was fabricated which showed the real-time monitoring of glucose in a smartphone. This novel approach paves the way for the design and fabrication of cost-effective, low-potential sensors, which would reduce overall costs and enhance the performance of sensing devices.

Development of a wireless multichannel miniature impedance measurement system and its application for bolt loosening detection

The piezoelectric impedance-based technique is always regarded as one of the most promising structural health monitoring and nondestructive evaluation methods. In recent years, impedance measurement chip AD5933 with the characteristics of high integration and cost-effectiveness makes it possible to address the huge and high-cost problems of the commercialized impedance measurement instrument during the process of structural health monitoring and defect identification. However, it still faces lots of challenges for the chips to be utilized in practical applications due to several limitations, such as short distance for data transmission, single measurement channel and artificial attendant requirement. In this paper, a wireless multichannel miniature impedance measurement system composed by the front-end measurement device and the remote measurement and control platform on the server, is firstly developed and presented with the functions of wireless data transmission, multi-channel acquisition and remote data post-processing. Subsequently, the design concept and composition of the system were introduced in detail. Then, a series of piezoelectric transducers related tests were conducted to validate its impedance measurement performance, especially when comparing with the ones measured by commercialized instruments. In addition, to verify its effectiveness and feasibility of the developed system for the structural damage detection, a bolt loosening detection experiment on the flange connection of a pipeline specimen was investigated for its damage localization and severity quantification. Finally, all the results demonstrated that the developed system provides a great possibility to be used as a convenient and portable impedance measurement tool for the civil structural health monitoring and damage identification in practical applications.

The Development of a Novel Nitrate Portable Measurement System Based on a UV Paired Diode-Photodiode.

Nitrates can cause severe ecological imbalances in aquatic ecosystems, with considerable consequences for human health. Therefore, monitoring this inorganic form of nitrogen is essential for any water quality management structure. This research was conducted to develop a novel Nitrate Portable Measurement System (NPMS) to monitor nitrate concentrations in water samples. NPMS is a reagent-free ultraviolet system developed using low-cost electronic components. Its operation principle is based on the Beer-Lambert law for measuring nitrate concentrations in water samples through light absorption in the spectral range of 295-315 nm. The system is equipped with a ready-to-use ultraviolet sensor, light emission diode (LED), op-amp, microcontroller, liquid crystal display, quartz cuvette, temperature sensor, and battery. All the components are assembled in a 3D-printed enclosure box, which allows a very compact self-contained equipment with high portability, enabling field and near-real-time measurements. The proposed methodology and the developed instrument were used to analyze multiple nitrate standard solutions. The performance was evaluated in comparison to the Nicolet Evolution 300, a classical UV-Vis spectrophotometer. The results demonstrate a strong correlation between the retrieved measurements by both instruments within the investigated spectral band and for concentrations above 5 mg NO3-/L.

Sustainable approaches to analyzing phenolic compounds: a green chemistry perspective.

Innovative and eco-friendly methodologies for the determination of phenolic compounds, showing a paradigm shift in analytical chemistry toward sustainability. Phenolic compounds, valued for their diverse health benefits, have historically been analyzed using methods that often involve hazardous solvents and energy-intensive processes. This review focuses on green analytical chemistry principles, emphasizing sustainability, reduced environmental impact, and analytical efficiency. The use of DES, specifically Ch: Chl-based DES, emerges as a prominent green alternative for extracting phenolic compounds from various sources. The integration of UAE with DES enhances extraction efficiency, contributing to a more sustainable analytical approach. Furthermore, the review highlights the significance of DLLME and SPME in reducing solvent consumption and simplifying extraction procedures. These techniques exemplify the commitment to making phenolic compound analysis environmentally friendly. The incorporation of portable measurement tools, such as smartphones, into analytical methodologies is a notable aspect discussed in the review. Techniques like UA-DLLME leverage portable devices, making phenolic compound determination more accessible and versatile. Anticipating the future, the review foresees ongoing advancements in sustainable analytical approaches, driven by collaborative efforts across diverse disciplines. Novel solvents, extraction techniques, and portable measurement methods are expected to play pivotal roles in the continuous evolution of green analytical methodologies for the analysis of phenolic compounds. The review encapsulates a transformative journey toward environmentally responsible and efficient analytical practices, paving the way for further research and application in diverse analytical settings.

Design and Development of A Portable Conductivity-Based Salinity Measurement System for Coastal Well Water

Design and Development of A Portable Conductivity-Based Salinity Measurement System for Coastal Well Water