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A method for particulate matter 2.5 (PM2.5) biotoxicity assay using luminescent bacterium
摘要： The ability to analyze biotoxicity of atmospheric pollution plays an important role in public health. It provides the potential to directly analyze the health information of at-risk individuals. Although air quality standards have received significant attention in many countries, the potential for better biotoxicity assessment has remained largely unexplored. Here we propose a method using one kind of luminescent bacterium Photobacterium phosphoreum to detect the biotoxicity of atmospheric particulate matter ≤ 2.5 μm (PM2.5). Combined with the results of air pollution data of the year 2013–2014, this method has been proven to have good biotoxicity detection performance, and can evaluate the severity of at least 85% of PM2.5 related biotoxicity in Shanghai during this time period. Based on an established algorithm of this detection system, the biotoxicity of twelve PM2.5 real samples (collected over a month) were tested and divided into different biotoxicity levels. It allows an effective evaluation of biotoxicity of PM2.5 due to the quick and sensitive response of bioluminescence to the concentration of toxic components, which provides a valuable reference to evaluate the biotoxicity of PM2.5. This established method can be easily applied to the analysis and evaluation of any other PM2.5 samples assay by following the steps.
关键词： Atmospheric PM2.5,Public health,Photobacterium phosphoreum,Air pollution,Luminescent bacterium,Biotoxicity detection
更新于2025-09-23 15:23:52
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Toward a new age of patient centricity? The application of eye-tracking to the development of connected self-injection systems
摘要： Background: Increasing interest in digitally enhanced drug delivery tools urges industry and academia to rethink current approaches to product usability. This article introduces mobile eye-tracking, generating detailed contextual data about user engagement with connected self-injection systems as a new methodological approach to formative usability assessment. Methods: A longitudinal case study with a total of 35 injection-na?ve participants was conducted. In three consecutive experiments, eye-tracking was applied to formative usability testing of a novel connected self-injection device. Three eye-tracking derived usability indicators were established to assess product effectiveness, efficiency, and ease of use. Results: Analysis of the data revealed events of user hesitation, process interruption and unintended action, and these occurrences could either be completely eliminated or significantly reduced throughout the process. At the same time, the overall use duration decreased from 86.1 to 58.7 sec. Analysis revealed that product modifications successfully guided user attention to those interface elements most relevant during each task, thereby improving product ease-of-use. Conclusions: The step-wise improvement in the usability indicators demonstrates that iteratively applying eye-tracking methods effectively supports the user-centered design of connected self-injection systems. The results highlight how eye-tracking can be employed to gain an in-depth understanding of patient engagement with novel healthcare technologies.
关键词： smart devices,digital health,eye-tracking,self-injection devices,Connected drug delivery,patient centricity,formative usability
更新于2025-09-23 15:23:52
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Sensitive Damage Detection of Reinforced Concrete Bridge Slab by ``Time-Variant Deconvolution'' of SHF-Band Radar Signal
摘要： In this paper, we focus on ground-penetrating radar (GPR) for infrastructural health monitoring, especially for the monitoring of reinforced concrete (RC) bridge slab. Due to the demand of noncontact and high-speed monitoring technique which can handle vast amounts of aging infrastructures, GPR is a promising tool. However, because radar images consist of many reflected waves, they are usually difficult to interpret. Furthermore, the spatial resolution of system is not enough considering the thickness of target damages, cracks, and segregation are millimeter-to-centimeter order while the wavelength of ordinary GPR ultrahigh-frequency band is over 10 cm. To address these problems, for the purpose of sensitive damage detection, we propose a new algorithm based on deconvolution utilizing a super high-frequency (SHF) band system. First, a distribution of reflection coefficient is inversely estimated by 1-D bridge slab model. Because concrete is found to be a lossy medium at SHF band, we consider the attenuation of signal in deconvolution. The algorithm is called 'time-variant deconvolution' in this paper. After the validation by simulation, the effects of the algorithm and frequency band on damage detection accuracy are evaluated by a field experiment. Though the results show a 1-mm horizontal crack is not detected by measured waves, when it is filled with water, it is detected by time-variant deconvolution. Moreover, the 1-mm dried crack is detected only by time-variant deconvolution at SHF band, which greatly emphasizes the peaks of the reflection coefficient of the crack.
关键词： thin cracks and segregation detection,Ground-penetrating radar (GPR),infrastructural health monitoring,time-variant deconvolution
更新于2025-09-23 15:23:52
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Numerical and experimental investigation of damage severity estimation using Lamb wave–based imaging methods
摘要： In this article, estimation of crack size, shape, and orientation was investigated numerically and experimentally using Lamb waves. A hybrid global–local approach was used in conjunction with the imaging methods for the numerical simulation. The hybrid global–local approach allowed fast and efficient prediction of scattering wave signals for Lamb wave interaction with crack from various incident directions. The simulation results showed the directionality effect of the scattering wave signals and suggested an optimum transmitter–sensor configuration. Two imaging methods were used: one involves the synthetic time reversal concept and the other involves Gaussian distribution function. Both imaging methods show very good agreement during simulations. Experiments were designed and conducted based on the simulated results. A network of eight piezoelectric wafer active sensors was used to capture the scattering waves from the crack. Both the pitch-catch and pulse-echo experimental modes were used. The directionality effect of incident Lamb waves on the imaging results was studied. The effect of summation, multiplication, and combined algorithms for each imaging method was studied. It was found that both methods can successfully predict the crack size and orientation. An attempt was made to use these imaging methods for detecting and sizing smaller sized damage (1- to 3-mm-diameter hole). It was found that these methods can successfully localize the hole, but size estimation was a bit challenging because of the smaller dimensions. The scattering waves for various hole sizes were studied.
关键词： synthetic time reversal,crack sizing,Structural health monitoring,wave propagation,scattering waves
更新于2025-09-23 15:23:52
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Interfacial adhesion between embedded fibre optic sensors and epoxy matrix in composites
摘要： Fibre optic (FO) sensors are becoming increasingly popular for different applications in structural monitoring. Among their excellent properties, a strong interest for this type of sensors are represented by the possibility of embedding FOs inside composite components. In this case, one of the factors that significantly influence the efficiency of the whole Structural Health Monitoring (SHM) system is the interfacial adhesion between FO sensors and the host material. The main objective of this work is to investigate the interfacial adhesion between embedded fibre optic sensors and epoxy matrix to find the best type of optical fibre to be used in epoxy matrices to produce smart composites. Four types of optical fibres with different diameters and coatings (i.e. polyimide, polyacrylate and ormoceramic) were used. Pull-out tests were carried out and different methods were used to obtain the composite/optical fibre interfacial properties. Finally, an optical microscopy and Scanning Electron Microscopy (SEM) analysis were performed to characterize the fibre/matrix interfaces. It was found that the optical fibre that presented the highest energy required for interface rupture and, consequently, less invasiveness to the host material was the ormoceramic fibre with the smallest diameter.
关键词： Structural health monitoring,Pull-out test,interfacial adhesion,fibre optics sensors
更新于2025-09-23 15:23:52
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[IEEE 2018 International Conference on Intelligent and Innovative Computing Applications (ICONIC) - Mon Tresor, Plaine Magnien, Mauritius (2018.12.6-2018.12.7)] 2018 International Conference on Intelligent and Innovative Computing Applications (ICONIC) - Development of an IR-based Device for Wireless Communication in Community Health Centres
摘要： With the increase in implementation of advanced communication equipment, especially in the medical sector, finding solutions to anticipated problems has become paramount. Our envisaged problem is the uneasy procedure of taking patients’ variables frequently in community health centers, where there is usually minimal support staff. This paper indicates that human variables such as body temperature and movement at a special ward in a community health care center are transferable from one computer to another. However, our implementation integrated a temperature sensor (LM35), pyroelectric infrared, and infrared to a low-cost Arduino-generic Lilypad microcontroller (as the transmitter). The developed device was able to communicate with the receiver side (comprised of Arduino Mega, infrared receiver, and a computer). We were able to transfer data seamlessly from Mr. C. E. Ngene to a remote computer for analysis. This project will make up for the unavailability of expensive devices and low workforce in the rural community health centers. This designed device can help patients to be attended to quickly as the patients start to have issues.
关键词： sensors,infrared,health,remote monitoring,optical wireless communication
更新于2025-09-23 15:22:29
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Fibre Bragg grating sensor applications for structural health monitoring
摘要： Purpose – Structural health monitoring (SHM) has become an attractive subject in aerospace engineering ?eld considering the opportunity to avoid catastrophic failures by detecting damage in advance and to reduce maintenance costs. Fibre Bragg Grating (FBG) sensors are denoted as one of the most promising sensors for SHM applications as they are lightweight, immune to electromagnetic effects and able to be embedded between the layers of composite structures. The purpose of this paper is to research on and demonstrate the feasibility of FBG sensors for SHM of composite structures. Design/methodology/approach – Applications on thin composite beams intended for SHM studies are presented. The sensor system, which includes FBG sensors and related interrogator system, and manufacturing of the beams with embedded sensors, are detailed. Static tension and torsion tests are conducted to verify the effectiveness of the system. Strain analysis results obtained from the tests are compared with the ones obtained from the ?nite element analyses conducted using ABAQUS? software. In addition, the comparison between the data obtained from the FBG sensors and from the strain gauges is made by also considering the noise content. Finally, fatigue test under torsion load is conducted to observe the durability of FBG sensors. Findings – The results demonstrated that FBG sensors are feasible for SHM of composite structures as the strain data are accurate and less noisy compared to that obtained from the strain gauges. Furthermore, the convenience of obtaining reliable data between the layers of a composite structure using embedded FBG sensors is observed. Practical implications – Observing the advantages of the FBG sensors for strain measurement will promote using FBG sensors for damage detection related to the SHM applications. Originality/value – This paper presents applications of FBG sensors on thin composite beams, which reveal the suitability of FBG sensors for SHM of lightweight composite structures.
关键词： Torsion test,Tension test,Structural health monitoring,Composite beams,Fibre Bragg grating sensors
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE International Conference on RFID Technology & Application (RFID-TA) - Macau, Macao (2018.9.26-2018.9.28)] 2018 IEEE International Conference on RFID Technology & Application (RFID-TA) - Perfectly Synchronized Streaming from Digitally Modulated Multiple Backscatter Sensor Tags
摘要： This paper proposes a multiple access method, referred to as Multiple Subcarrier Multiple Access (MSMA), for perfectly synchronized concurrent data collection from a group of passive backscatter wireless sensor tags and its experimental evaluation. By achieving less than 128 micro second synchronization error, backscatter communications can be applied to structural health monitoring of artifacts such as civil structures and machineries. In MSMA, each sensor tag uses a dedicated subcarrier frequency to produce a modulated backscatter. The sensor data is superposed onto the subcarrier either with an analog or a digital modulation. The inevitable harmonics among the subcarriers, stemming from the backscatter principle, can be rejected by numerically calculating the harmonic replicas and subtracting them from the observed signal in a software defined receiver. A frame based signal processing in the receiver results in no relative synchronization error among subcarriers even after the interference rejection. Since the interference rejection can be done before the demodulation and decoding, the concurrency can be secured irrespective to the choice of modulation method. We developed a prototype of MSMA using LabVIEW communications Software Defined Radio environment and prototype sensor tags using discrete electrical parts. The performances and limitation of MSMA using digitally modulated subcarriers are evaluated both in wired and wireless environments with up to four backscatter sensors.
关键词： Structural Health Monitoring,Software Defined Radio,Interference Rejection,Passive backscatter
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE International Conference on RFID Technology & Application (RFID-TA) - Macau (2018.9.26-2018.9.28)] 2018 IEEE International Conference on RFID Technology & Application (RFID-TA) - Secondary Near Field RFID Antennas for Wireless Structural Health Monitoring Systems
摘要： In this paper it is shown that a conductive feed used to excite a standing surface wave on a metallic object can be used to reliably power a passive UHF RFID sensor tag mounted to the same. The read rates of this method and that of free space are compared. Findings show that along the metallic bar structure, and for a greater distance, minimum read rates were at least 9 times greater than in free space. The maximum read rates were found to be around 20 times larger than in free space. It is shown that by utilizing the metallic structure itself, as a secondary nearfield antenna, it is possible to read accelerometer sensor data effectively from a passive UHF sensor tag such as the WISP 5.0. Such a technique may provide a low cost alternative to traditional SHM systems.
关键词： structural health monitoring,acceleration,UHF RFID,metal,sensing,WISP
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE 13th Annual International Conference on Nano/Micro Engineered and Molecular Systems (NEMS) - Singapore, Singapore (2018.4.22-2018.4.26)] 2018 IEEE 13th Annual International Conference on Nano/Micro Engineered and Molecular Systems (NEMS) - Self-Powered, High-Sensitive Human Cutaneous Activities Sensor
摘要： A self-powered piezoelectric sensor based on lead-free (K,Na)NbO3 (KNN) thin film for human health monitoring is presented. The sensor is fabricated on a flexible substrate and exhibits high sensitivity and stability. It can detect various physiological signals such as pulse, respiration, and body movement. The results demonstrate its potential for wearable health monitoring applications.
关键词： piezoelectric sensor,KNN thin film,health monitoring,lead-free,flexible substrate,wearable
更新于2025-09-23 15:22:29