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Extracellular vesicles (EVs) are promising tools for the early diagnosis of diseases, and bacterial membrane vesicles (MVs) are especially important in health and environment monitoring. However, detecting EVs or bacterial MVs presents significant challenges for the clinical translation of EV-based diagnostics. In this Review, we provide a comprehensive discussion on the basics of nanoplasmonic sensing and emphasize recent developments in nanoplasmonics-based optical sensors to effectively identify EVs or bacterial MVs. We explore various nanoplasmonic sensors tailored for EV or bacterial MV detection, emphasizing the application of localized surface plasmon resonance through gold nanoparticles and their multimers. Additionally, we highlight advanced EV detection techniques based on surface plasmon polaritons using plasmonic thin film and nanopatterned structures. Furthermore, we evaluate the improved detection capability of surface-enhanced Raman spectroscopy in identifying and classifying these vesicles, aided by plasmonic nanostructures. Nanoplasmonic sensing techniques have remarkable precision and sensitivity, making them a potential tool for accurate EV detection in clinical applications, facilitating point-of-care molecular diagnostics. Finally, we summarize the challenges associated with nanoplasmonic EV or bacterial MV sensors and offer insights into potential future directions for this evolving field. [ABSTRACT FROM AUTHOR]

Accurate hydrological data with high spatial resolution is important for flood risk and water resource management, particularly under the context of climate change. The cost of monitoring networks, as well as the characteristics of the hydrological environment itself, can be a barrier to meeting these data requirements, however. This study covers the design and testing of a low-cost, "build-it-yourself", instream water depth sensor providing an assessment of its potential in future hydrological monitoring projects. The low-cost sensor was built using an Arduino microcontroller, a differential pressure sensor and a thermistor, a real-time clock, and an SD card module. The low-cost logger was deployed in tandem with a factory-calibrated Solinst®LevelLogger® 5 Junior for 6 months in the River Wissey, UK. We found the mean absolute error of the Arduino-based logger relative to the commercial setup to be ±0.69 cm for water depth and ±0.415 °C for water temperature. Economically, the Arduino-based logger offers an advantage, costing a total of £133.35 (USD 168.26 at time of publication) comparative to the industrial comparison's cost of £408 (USD 514.83 at time of publication). This study concludes that the low cost of the Arduino-based logger gives a strong advantage to its incorporation in hydrological data collection, if the trade-offs (i.e., time investment and accuracy) are considered acceptable and appropriate for a project. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The COVID-19 pandemic has changed our common habits and lifestyle. Occupancy information is valued more now due to the restrictions put in place to reduce the spread of the virus. Over the years, several authors have developed methods and algorithms to detect/estimate occupancy in enclosed spaces. Similarly, different types of sensors have been installed in the places to allow this measurement. However, new researchers and practitioners often find it difficult to estimate the number of sensors to collect the data, the time needed to sense, and technical information related to sensor deployment. Therefore, this systematic review provides an overview of the type of environmental sensors used to detect/estimate occupancy, the places that have been selected to carry out experiments, details about the placement of the sensors, characteristics of datasets, and models/algorithms developed. Furthermore, with the information extracted from three selected studies, a technique to calculate the number of environmental sensors to be deployed is proposed. [ABSTRACT FROM AUTHOR]

In this paper we propose an application written in LabVIEW through which a number of transducers or sensors are controlled so that the data from them are taken according to a certain algorithm and also this application realize the data processing. Control consists in selection for each of these transducers, their inputs selection and retrieves information from them. The physical connection between used transducers and master is made through RS-485 bus and the transmission protocol used is Modbus RTU. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to report an insightful portable microfluidic system for rapid and selective sensing of Hg2+ in the picomolar (pM) concentration using microcantilever-based piezoresistive sensor. The detection time for various laboratory-based techniques is generally 12–24 h. The majority of modules used in the proposed platform are battery oriented; therefore, they are portable and handy to carry-out on-field investigations. Design/methodology/approach: In this study, the authors have incorporated the benefit of three technologies, i.e. thin-film, nanoparticles (NPs) and micro-electro-mechanical systems, to selectively capture the Hg2+ at the pM concentration. The morphology and topography of the proposed sensor are characterized using field emission scanning electron microscopy and verification of the experimental results using energy dispersive X-ray. Findings: The proposed portable microfluidic system is able to perform the detection in 5 min with a limit of detection (LOD) of 0.163 ng (0.81 pM/mL) for Hg2+, which perfectly describes its excellent performance over other reported techniques. Research limitations/implications: A microcantilever-based technology is perfect for on-site detection, and a LOD of 0.163 ng (0.81 pM/mL) is outstanding compared to other techniques, but the fabrication of microcantilever sensor is complex. Originality/value: Many researchers used NPs for heavy metal ions sensing, but the excess usage and industrialization of NPs are rapidly expanding harmful consequences on the human life and nature. Also, the LOD of the NPs-based method is limited to nanomolar concentration. The suggested microfluidic system used the benefit of thin-film and microcantilever devices to provide advancement over the NPs-based approach and it has a selective sensing in pM concentration. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is a new thin-film based sensor proposed for sensitive and selective detection of mercury (Hg2+) ions in water. The thin-film platform is easy to use and quick for heavy metal ions (HMIs) detection in the picomolar range. Ion-selective self-assembled monolayer's (SAM) of thiol used for the detection of HMIs above the Au/Ti top surface. Design/methodology/approach: A thin-film based platform is suitable for the on-field experiments and testing of water samples. HMIs (antigen) and thiol-based SAM (antibody) interaction results change in surface morphology and topography. In this study, the authors have used different characterization techniques to check the selectivity of the proposed method. This change in the morphology and topography of thin-film sensor checked with Fourier-transform infrared spectroscopy, surface-enhanced Raman scattering spectroscopy, atomic force microscopy and scanning electron microscopy with energy dispersive x-ray analysis used for high-resolution images. Findings: This thin-film based platform is straightforward to use and suitable for real-time detection of HMIs at the picomolar range. This thin-film based sensor platform capable of achieving a lower limit of detection (LOD) 27.42 ng/mL (136.56 pM) using SAM of Homocysteine-Pyridinedicarboxylic acid to detect Hg2+ ions. Research limitations/implications: A thin-film based technology is perfect for real-time testing and removal of HMIs, but the LOD is higher as compared to microcantilever-based devices. Originality/value: The excessive use and commercialization of nanoparticle (NPs) are quickly expanding their toxic impact on health and the environment. The proposed method used the combination of thin-film and NPs, to overcome the limitation of NPs-based technique and have picomolar (136.56 pM) range of HMIs detection. The proposed thin-film-based sensor shows excellent repeatability and the method is highly reliable for toxic Hg2+ ions detection. The main advantage of the proposed thin-film sensor is its ability to selectively remove the Hg2+ ions from water samples just like a filter and a sensor for detection at picomolar range makes this method best among the other current-state of the art techniques. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to present a study on miniaturized instruments for analytical chemistry with a microplasma as the excitation source. Design/methodology/approach: The atmospheric pressure glow microdischarge could be ignited inside a ceramic structure between a solid anode and a liquid cathode. As a result of the cathode sputtering of the solution, it was possible to determine its chemical composition by analyzing the emission spectra of the discharge. Cathodes with microfluidic channels and two types of anodes were constructed. Both types were tested through experimentation. Impact of the electrodes geometry on the discharge was established. A cathode aperture of various sizes and anodes made from different materials were used. Findings: The spectroscopic properties of the discharge and its usefulness in the analysis depended on the ceramic structure. The surface area of the cathode aperture and the flow rate of the solution influence on the detection limits (DLs) of Zn and Cd. Originality/value: Constructed ceramic structures were able to excite elements and their laboratory-size systems. During the experiments, Zn and Cd were detected with DLs 0.024 and 0.053 mg/L, respectively. [ABSTRACT FROM AUTHOR]

Purpose This paper aims to propose a robust and efficient method for vanishing point detection in unstructured road scenes.Design/methodology/approach The proposed method includes two main stages: drivable region estimation and vanishing point detection. In drivable region estimation stage, the road image is segmented into a set of patches; then the drivable region is estimated by the patch-wise manifold ranking. In vanishing point detection stage, the LSD method is used to extract the straight lines; then a series of principles are proposed to remove the noise lines. Finally, the vanishing point is detected by a novel voting strategy.Findings The proposed method is validated on various unstructured road images collected from the real world. It is more robust and more efficient than the state-of-the-art method and the other three recent methods. Experimental results demonstrate that the detected vanishing point is practical for vision-sensor-based navigation in complex unstructured road scenes.Originality/value This paper proposes a patch-wise manifold ranking method to estimate the drivable region that contains most of the informative clues for vanishing point detection. Based on the removal of the noise lines through a series of principles, a novel voting strategy is proposed to detect the vanishing point. [ABSTRACT FROM AUTHOR]

A hybrid sensor for monitoring volatile organic compounds in air is developed. The device combines two orthogonal sensing principles, selective molecular binding with a microfabricated quartz tuning fork detector and separation of analytes with a column. The tuning fork detector is functionalized with molecular imprinted polymers for selective binding to benzene, toluene, ethylbenzene, and xylenes (BTEX), and the separation column provides further discrimination of the analytes for real world complex sample analysis. The device is wireless, portable, battery-powered, and cell-phone operated, and it allows reliable detection in parts per billion by volume-levels of BTEX in the presence of complex interferents. The hybrid device is suitable for occupational, environmental health, and epidemiological applications. [ABSTRACT FROM PUBLISHER]

Environmental scientists are increasing their capitalization on advancements in technology, computation, and data management. However, the extent of that capitalization is unknown. We analyzed the survey responses of 434 graduate students to evaluate the understanding and use of such advances in the environmental sciences. Two-thirds of the students had not taken courses related to information science and the analysis of complex data. Seventy-four percent of the students reported no skill in programming languages or computational applications. Of the students who had completed research projects, 26% had created metadata for research data sets, and 29% had archived their data so that it was available online. One-third of these students used an environmental sensor. The results differed according to the students' research status, degree type, and university type. Changes may be necessary in the curricula of university programs that seek to prepare environmental scientists for this technologically advanced and data-intensive age. [ABSTRACT FROM AUTHOR]

This work provides a design for two types of sensors, based on the thermal dissipation and heat ratio methods of sap flow calculation, for moderate to large scale deployments for the purpose of monitoring tree transpiration. These designs include a procedure for making these sensors, a quality control method for the final products, and a complete list of components with vendors and pricing information. Both sensor designs were field tested alongside a commercial sap flow sensor to assess their performance and show the importance for quality controlling the sensor outputs. Results show that for roughly 2% of the cost of commercial sensors, self-made sap flow sensors can provide acceptable estimates of the sap flow measurements compared to the commercial sensors. [ABSTRACT FROM AUTHOR]

Abstract: With the advent of new instrumentation and sensors, more diverse types and increasing amounts of data are becoming available to environmental researchers and practitioners. However, accessing and integrating these data into forms usable for environmental analysis and modeling can be highly time-consuming and challenging, particularly in real time. For example, radar-rainfall data are a valuable resource for hydrologic modeling because of their high resolution and pervasive coverage. However, radar-rainfall data from the Next Generation Radar (NEXRAD) system continue to be underutilized outside of the operational environment because of limitations in access and availability of research-quality data products, especially in real time. This paper addresses these issues through the development of a prototype Web-based virtual sensor system at NCSA that creates real-time customized data streams from raw sensor data. These data streams are supported by metadata, including provenance information. The system uses workflow composition and publishing tools to facilitate creation and publication (as Web services) of user-created virtual sensors. To demonstrate the system, two case studies are presented. In the first case study, a network of point-based virtual precipitation sensors is deployed to analyze the relationship between radar-rainfall measurements, and in the second case study, a network of polygon-based virtual precipitation sensors is deployed to be used as input to urban flooding models. These case studies illustrate how, with the addition of some application-specific information, this general-purpose system can be utilized to provide customized real-time access to significant data resources such as the NEXRAD system. Additionally, the creation of new types of virtual sensors is discussed, using the example of virtual temperature sensors. [Copyright &y& Elsevier]

Low-cost networked fluid flow velocity sensors are needed for high-density sampling in environmental research and other applications requiring automated fluid flow velocity mapping. The flow sensor in this paper is the “target” type consisting of a flap that deflects in the flow, changing the resistance of a strain gauge. A highly compliant flexible resistor promises to reduce costs by serving as the flow target and by eliminating the signal amplification circuitry needed for conventional strain gauges. However, we show that the individual calibration of these resistive sensors is critical for recovering the stream flow velocity. A wireless network is used for the mass calibration of multiple sensors in a test flume. After individual sensor calibrations are obtained, the same wireless network can be used to collect flow velocity data in the sensor application. A modular connection system enables the user to reconfigure quickly the system's physical layout for calibration or deployment purposes. The results are reported on an outdoor deployment of the flow sensors for logging stream flow data in environmental research. [ABSTRACT FROM AUTHOR]

This paper discusses the use of environmental sensors, wireless networks and mobile media as technologies of sensation in the city. While these devices enable a ‘digital city,’ in many respects they appear to be immaterial, operating beyond sense. Further, drawing on two case studies presented by the Digital Cities project in Montreal, the paper considers how applications of environmental sensors and mobile media give rise to new conditions and questions for how we configure sense in the ‘digital city.’ The paper ultimately finds that sensors direct us toward new sites, assemblages and practices of sensation within the urban sensorium. [ABSTRACT FROM AUTHOR]

Abstract: The use of polypyrrole (PPy)-based electronic noses (ENs) for environmental and industrial analysis has gained considerable momentum in the past decade. Toxic and non-toxic substances, such as ammonia, nitrogen oxides, carbon monoxide, sulphur dioxide, hydrogen sulphide, methane, oxygen, hydrogen, alcohols, phenol, benzene and water vapours have been successfully determined by PPy-based ENs in materials ranging from water and beverages to waste waters and sewage effluents. This article reviews the various research efforts that have been carried out over the past decade on the development of PPy-based ENs for environmental and industrial analysis. It also provides an overview on future prospects and development of ENs for broader applications in this area. [Copyright &y& Elsevier]

[Display omitted] • A flexible electrochemical sensor with an integrated reference electrode was fabricated. • Cu-chitosan nanoparticles were electrochemically deposited on the working electrode. • Incorporation of chitosan into Cu enhanced performance towards Pb2+ detection due to −OH and -NH 2 functional groups. • The sensor exhibits excellent sensitivity and selectivity with a low limit of detection. • The sensor was successfully applied for mining wastewater and soil leachate. In this work, a novel copper-chitosan (Cu-chitosan) nanocomposite-based flexible electrochemical sensor with an integrated Ag/AgCl reference electrode is fabricated. The electrochemical sensor is fabricated using low-cost screen-printing technology on a flexible substrate, followed by the electrochlorination of silver to form an integrated Ag/AgCl reference electrode and electrochemical deposition of a Cu-chitosan nanocomposite film to produce a working electrode. The surface chemical analysis of the working and reference electrodes using XPS (X-ray photoelectron spectroscopy) shows the formation of functional layers. The fabricated Cu-chitosan nanocomposite-based sensors are used to determine the trace level lead (Pb2+) ions in real-world water samples (i.e., tap water, mining wastewater, and soil leachate) using square wave anodic stripping voltammetry (SWSAV). A noticeable peak for lead ions is observed at ∼0.46 V vs. integrated Ag/AgCl reference electrode. The limit of detection (LOD) of the developed flexible electrochemical sensor in tap water is 0.72 ppb with the relative standard deviations (n = 10) of 0.65 %. The fabricated electrochemical sensor exhibits a higher response to lead ions (Pb2+) than the previously reported copper-based electrochemical sensor. These results show that chitosan's presence on the composite material enhances the sensitivity and mechanical flexibility. [ABSTRACT FROM AUTHOR]

We report on the use of quartz-enhanced photoacoustic spectroscopy for continuous carbon-dioxide measurements in humid air over a period of six days. The presence of water molecules alters the relaxation rate of the target molecules and thus the amplitude of the photoacoustic signal. Prior to the measurements, the photoacoustic sensor system was pre-calibrated using CO2 mole fractions in the range of 0–10−3 (0–1000 ppm) and at different relative humidities between 0% and 45%, while assuming a model hypothesis that allowed the photoacoustic signal to be perturbed linearly by H2O content. This calibration technique was compared against an alternative learning-based method, where sensor data from the first two days of the six-day period were used for self-calibration. A commercial non-dispersive infrared sensor was used as a CO2 reference sensor and provided the benchmark for the two calibration procedures. In our case, the self-calibrated method proved to be both more accurate and precise. [ABSTRACT FROM AUTHOR]

A novel bismuth (Bi)-biopolymer (chitosan) nanocomposite screen-printed carbon electrode was developed using a Bi and chitosan co-electrodepositing technique for detecting multiple heavy metal ions. The developed sensor was fabricated with environmentally benign materials and processes. In real wastewater, heavy metal detection was evaluated by the developed sensor using square wave anodic stripping voltammetry (SWASV). The nanocomposite sensor showed the detection limit of 0.1 ppb Zn2+, 0.1 ppb Cd2+ and 0.2 ppb Pb2+ in stock solutions. The improved sensitivity of the Bi-chitosan nanocomposite sensor over previously reported Bi nanocomposite sensors was attributed to the role of chitosan. When used for real wastewater samples collected from a mining site and soil leachate, similar detection limit values with 0.4 ppb Cd2+ and 0.3 ppb Pb2+ were obtained with relative standard deviations (RSD) ranging from 1.3% to 5.6% (n = 8). Temperature changes (4 and 23 °C) showed no significant impact on sensor performance. Although Zn2+ in stock solutions was well measured by the sensor, the interference observed while detecting Zn2+ in the presence of Cu2+ was possibly due to the presence of Cu-Zn intermetallic species in mining wastewater. Overall, the developed sensor has the capability of monitoring multiple heavy metals in contaminated water samples without the need for complicated sample preparation or transportation of samples to a laboratory. [ABSTRACT FROM AUTHOR]

The emerging field of computational acoustic monitoring aims at retrieving high-level information from acoustic scenes recorded by some network of sensors. These networks gather large amounts of data requiring analysis. To decide which parts to inspect further, we need tools that automatically mine the data, identifying recurring patterns and isolated events. This requires a similarity measure for acoustic scenes that does not impose strong assumptions on the data.The state of the art in audio similarity measurement is the “bag-of-frames” approach, which models a recording using summary statistics of short-term audio descriptors, such as mel-frequency cepstral coefficients (MFCCs). They successfully characterise static scenes with little variability in auditory content, but cannot accurately capture scenes with a few salient events superimposed over static background. To overcome this issue, we propose a two-scale representation which describes a recording using clusters of scattering coefficients. The scattering coefficients capture short-scale structure, while the cluster model captures longer time scales, allowing for more accurate characterization of sparse events. Evaluation within the acoustic scene similarity framework demonstrates the interest of the proposed approach. [ABSTRACT FROM AUTHOR]