Academic literature on the topic 'Long range displacement sensor'
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Journal articles on the topic "Long range displacement sensor"
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Alonso-Murias, Monserrat C., David Monzón-Hernández, Osvaldo Rodríguez-Quiroz, J. Enrique Antonio-Lopez, Axel Schülzgen, Rodrigo Amezcua-Correa, and Joel Villatoro. "Long-range multicore optical fiber displacement sensor." Optics Letters 46, no. 9 (April 30, 2021): 2224. http://dx.doi.org/10.1364/ol.421004.
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Xue, Songtao, Kang Jiang, Shuai Guan, Liyu Xie, Guochun Wan, and Chunfeng Wan. "Long-Range Displacement Meters Based on Chipped Circular Patch Antenna." Sensors 20, no. 17 (August 28, 2020): 4884. http://dx.doi.org/10.3390/s20174884.
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This paper presents a passive wireless long-range displacement sensor that is based on the circular patch antenna, and the detecting range of the sensor can be customized. The sensor consists of a chipped circular antenna with two opened rectangular windows, a substrate, and a ground plate with a sloping channel. No bonding between the antenna and the ground plate allows for the chipped antenna to slide along the sloping channel. The channel will drive the current flow on the plate once the chip is activated, increasing the effective electrical length and, consequently, decreasing the resonant frequency of the circular antenna. The sensing mechanism equates the measuring displacement to the relative movement of the antenna with respect to the ground that achieves the measurement of long-range displacement and, thus, the proposed sensor can avoid stress damage to the antenna due to excessive deformation. Three different range sensors were simulated in the the Ansoft high frequency structure simulator (HFSS). The results show that the resonance frequency of the antenna has a linear relationship with the varying chute depth beneath the chip. Three sensors were fabricated, and the experimental results also validated that the sensitivity of the sensor can be adjusted.
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Khiat, Ali. "Silicon grating microfabrication for long-range displacement sensor." Journal of Micro/Nanolithography, MEMS, and MOEMS 7, no. 2 (April 1, 2008): 021007. http://dx.doi.org/10.1117/1.2909459.
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Bonse, M. H. W., F. Zhu, and H. F. van Beek. "A long-range capacitive displacement sensor having micrometre resolution." Measurement Science and Technology 4, no. 8 (August 1, 1993): 801–7. http://dx.doi.org/10.1088/0957-0233/4/8/001.
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Thomas, Jineesh, T. R. Rajanna, and Sundarrajan Asokan. "Temperature Compensated FBG Displacement Sensor for Long-Range Applications." IEEE Sensors Letters 4, no. 1 (January 2020): 1–4. http://dx.doi.org/10.1109/lsens.2019.2959377.
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Hu, Ye, Qian Hui Zhao, Yong Ming Chen, and Lei Wang. "A Simple and Long-Range Displacement Measurement System." Applied Mechanics and Materials 341-342 (July 2013): 839–42. http://dx.doi.org/10.4028/www.scientific.net/amm.341-342.839.
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This paper introduces a well-used long range displacement measurement system. The advantages of the system are that the sensor's measurement range can be extended by optical linear scale with a simple structure, and the distance between the measured object and the sensor can be automatically adjusted. The feasibility of the measurement system is tested by simulation experiments, and the accuracy performance is evaluated with respect to both repeatability error and linearity error. The experimental results show that the displacement measurement system reaches a level of accuracy which is sufficient for operational requirements.
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Yu, Jian-ping, Wen Wang, Ke-qing Lu, De-qing Mei, and Zi-chen Chen. "A planar capacitive sensor for 2D long-range displacement measurement." Journal of Zhejiang University SCIENCE C 14, no. 4 (April 2013): 252–57. http://dx.doi.org/10.1631/jzus.c12mnt03.
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Liu, Rong Xian, Yong Fa Qin, and Fan Li. "The Research of the Shock Angular Displacement Sensor." Applied Mechanics and Materials 427-429 (September 2013): 1060–63. http://dx.doi.org/10.4028/www.scientific.net/amm.427-429.1060.
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Impact resistance angular displacement sensors are widely used in motion mechanical system, which not only requires the sensor having the advantages of large measurement range, long life, also the sensor need to withstand shock and vibration. We use the finite element analysis on the key structure of the sensor and design the sensor circuit.. The sensor has the advantages of high strength shell and flexible packaging, and it can withstand the impact of the gravitational acceleration 100g on three directions.
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Kim, Moo-Jin, and Won-Kyu Moon. "A new capacitive displacement sensor for high accuracy and long range." Journal of Sensor Science and Technology 14, no. 4 (July 30, 2005): 219–24. http://dx.doi.org/10.5369/jsst.2005.14.4.219.
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Kim, Moojin, Wonkyu Moon, Euisung Yoon, and Kwang-Ryeol Lee. "A new capacitive displacement sensor with high accuracy and long-range." Sensors and Actuators A: Physical 130-131 (August 2006): 135–41. http://dx.doi.org/10.1016/j.sna.2005.12.012.
Full textDissertations / Theses on the topic "Long range displacement sensor"
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Arora, Neha. "Contribution to the concept of micro factory : design of a flexible electromagnetic conveyor system." Thesis, Compiègne, 2017. http://www.theses.fr/2017COMP2347.
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L’objectif de la thèse est de réaliser un système de convoyage flexible permettant de déplacer des micro-objets. Ce système pourra être amené à être intégré dans une micro-usine ce qui nécessite une forte reconfigurabilité et une faible consommation d’énergie. Ces deux critères ont donc été considérés lors de la conception du système de convoyage. Ce dernier est basé sur un actionneur planaire électromagnétique, développé au sein du laboratoire Roberval, et sur une surface intelligente composée de 5 × 5 cellules élémentaires permettant chacune de déplacer la partie mobile dans les deux directions du plan et des rotations autour de l'axe perpendiculaire au plan. Un modèle analytique de l’actionneur a été développé afin de calculer les efforts électromagnétiques ainsi que le déplacement de la partie mobile. Ce modèle a été utilisé lors de la phase de conception du système de convoyage. Un prototype expérimental a ensuite été fabriqué et testé ce qui a permis de valider le principe de fonctionnement proposé. Des tests expérimentaux ont montré la possibilité de réaliser des déplacements de grande étendue dans les deux directions du plan. De multiples tests expérimentaux (pilotage en boucle ouverte, caractérisation des performances telles que rectitude de déplacement, répétabilité de positionnement, charge déplaçable, …) a été réalisée afin de qualifier les performances du système de convoyage. Les points sur la réalisation : - Une modélisation statique sous RADIA a été développée afin de concevoir la surface intelligente notamment la zone de transition entre deux cellules voisines. Une modélisation dynamique réalisée sous MATLAB a permis de simuler le comportement d’un moteur en boucle ouverte et en boucle fermée. - Un prototype de surface intelligente, composé d’un circuit imprimé multicouches (4 couches) de dimensions 130 mm x 130 mm, a été conçu sous EAGLE software. L’influence de la distance entre les deux premières couches a été étudiée à l’aide des modèles développés afin d'assurer un déplacement uniforme dans les deux directions. - Un test expérimental avec LABVIEW interface d'une cellule élémentaire de la surface intelligente avec une partie mobile composée de deux moteurs magnétiques orthogonaux a été réalisé et a permis de valider le fonctionnement du système de convoyage dans les deux directions du plan. - Une autre série de tests avec LABVIEW interface a été réalisée afin de valider expérimentalement le déplacement de la partie mobile avec la surface intelligente au niveau des zones de transition entre les cellules élémentaires. Ces tests expérimentaux ont montré des déplacements de grande étendue dans les deux directions du plan et de rotation autour de l'axe perpendiculaire au plan. Des déplacements de grande étendue et des rotations de la partie mobile ont été mesurés à l’aide d’une méthode de traitement d'image réalisée sous MATLAB. - Parallèlement, on a étudié un capteur à déplacement optique à haute résolution qui peut être intégré dans le convoyeur. Un algorithme robuste pour le traitement du signal de capteur à fibres optiques à haute résolution pour mesurer de déplacement est développé. Dans cet algorithme, la position optimale de la partie mobile est déterminée pour obtenir un basculement sans arrêt entre les sondes et l'algorithme est implémenté sous MATLAB et validée par la mise en œuvre des signaux expérimentaux. Ces travaux de thèse ont été publiés dans une revue internationale (Computers in Industry (COMIND)) et présentés dans des congrès internationaux (IEEE Sensors, REM Mechatronics, AIM, IWMF) pendant les années 2011 à 2016The aim of the thesis is to provide a flexible conveyor system for moving micro-objects. The system may need to be integrated into a micro-factory which requires high reconfigurability and low power consumption. These two criteria have been considered in the design of the conveyor system. The conveyor is based on a planar electromagnetic actuator developed in the Laboratoire Roberval of the UTC, and on smart surface composed of 5 x 5 unit cells; each ceii moves th movable part in the two directions of the plane. An analytical model of the actuator has been developed in order to calculate the electromagnetic forces and the displacement of the mobile part. This modei has been used during the design phase of the conveying system. An experimental prototype is then manufactured and tested which has validated the proposed principle of operation. Experimental tests have shown the ability to perform wide area displacement in both directions of the plane. Numerous experimental tests (control in open loop and closed loop performance characterization as straightness of movement, position repeatability, coupled- decoupled analysis...) have been done to qualify the performance of the conveyor system. Experiments for rotations about the axis perpendicular to the olane have also been performed successfully. Work synthesis: - Static modeling under RADIA was developed in order to design the conveyor surface especially for the transitio zone between two neighboring cells. A dynamic modeling under MATLAB allowed to simulate the behavior of single axis motor in open loop and closed loop control. - A conveyor surface prototype, consisting of a multilayer printed circuit board (4 layers) of dimensions 130 mm x 130 mm, was designed under EAGLE software. The influence of the distance between the first two layers was studied using the developed models to ensure uniform displacement in both the directions. - The experimental tests (with LABVIEW interface) of an elementary cell of the intelligent surface with a moving part composed of two orthogonal magnetic motors has been carried out that allowed to validate the operation of the conveying system in both directions of the plane. - Another series of tests with LABVIEW interface were carried out in order to validate experimentally the displacement of the mobile part with the smart surface at the transition zones between the elementary cells. - These experimental tests showed displacements of great extent in the two directions of the plane and of rotation about the axis perpendicular to the plane. - Long displacements and rotations of the moving part were measured using image processing algorithm developed in MATLAB. - At the same time, a high resolution fiber optic displacement sensor was studied that can be integrated into the conveyor surface locally for the precise positioning. A robust signal processing algorithm for high resolution displacement measurement was developed. In this algorithm, - The optimum position of the movable part is determined in order to obtain a continuous switching betwee the two fiber optic probes ; - The usable parts of the signals obtained from two probes were then filtered to measure the displacement using interpolation method ; The algorithm is implemented under MATLAB and validated by the implementation of the experimental signals. The work have been published in an international journal (Computers in Industry (COMIND)) and presented at international congresses (IEEE Sensors, REM Mechatronics, AIM, IWMF) during the years 2011 to 2016
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McMahill, Dan. "A high dynamic range capacitive displacement sensor." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/12343.
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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1993.Includes bibliographical references (leaves 125-126).
by Daniel Rea McMahill.
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Oliveira, Rúben Pedrosa. "Sensor networks with multiple technologies: short and long range." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/22735.
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Mestrado em Engenharia Eletrónica e TelecomunicaçõesLow-Power Wide Area Networks (LPWANs) are one set of technologies that are growing in the eld of the Internet of Things (IoT). Due to the long range capabilities and low energy consumption, Low-Power Wide Area Networks (LPWANs) are the ideal technologies to send small data occasionally. With their unique characteristics, LPWANs can be used in many applications and in di erent environments such as urban, rural and even indoor. The work developed in this dissertation presents a study on the LPWAN LoRa technology, by testing and evaluate its range, signal quality properties and its performance in delivering data. For this, three distinct scenarios are proposed and tested. The inclusion of LoRa in a multi-technology data gathering platform is the key objective of this dissertation. For this it is proposed: (1) an organization based in clusters of sensor nodes; (2) a Media Access Control (MAC) protocol to provide e cient communications through the LoRa technology; and nally, (3) a Connection Manager that is capable of managing the di erent available technologies in the sensor nodes and that is able to adapt its actions according to the acquired data type is proposed. The performed tests aim to perceive which type of parameters can in uence the performance of the overall proposed solution, as well as the advantages of a multi-technology approach in a data gathering platform.
Low-Power Wide Area Networks (LPWANs) são um conjunto de tecnologias em crescimento na área da Internet of Things (IoT). Devido ás suas capacidades de comunicar a longo alcance e de baixo consumo energético, as LPWANs apresentam-se como a tecnologia ideal para o envio ocasional de pequenas porções de dados. Ao possuírem características únicas, as LPWANs podem ser usadas em diversas aplicações e em diferentes ambientes, sejam eles urbanos, rurais ou interiores. O trabalho desenvolvido nesta dissertação apresenta um estudo acerca da tecnologia Long Range (LoRa), uma LPWAN, testando e avaliando o seu alcance, a qualidade do sinal e o desempenho na entrega de dados. Para isso, três cenários distintos são propostos e testados. A inclusão de LoRa numa plataforma de aquisição de dados com múltiplas tecnologias e um dos objectivos chave desta dissertação. Para isso, são propostas: (1) uma organização baseada em clusters de sensores; (2) um protocolo de controlo de acesso ao meio (MAC) para permitir que as comunicações através de LoRa sejam eficientes; e finalmente, (3) um gestor de conectividade com capacidade de gerir as diferentes tecnologias disponíveis nos sensores e que seja capaz de agir consoante o tipo de dados adquiridos. Os testes efectuados tem como objectivo perceber que tipo de parâmetros podem influenciar o desempenho global da soluçao proposta, bem como as vantagens de usar uma abordagem baseada em múltiplas tecnologias numa plataforma de aquisição de dados.
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Kihlberg, David, and Amir Ebrahimi. "Wireless Gas Sensor Nodes : With focus on Long Range (LoRa) communication." Thesis, Linköpings universitet, Elektroniska Kretsar och System, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-168669.
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Greenhouse gas emissions in indoor or outdoor areas are dangerous and can have short- or long-term effects on people’s health. There are several methods to monitor the air quality in such environments. This thesis project attempts to design and evaluate a wireless sensor network with two main characteristics such as long range and low power consumption. The sensor network is built upon Long Range Wide Area Network (LoRaWAN) protocol and is composed of sensor nodes and gateways. The sensor nodes are built upon a Raspberry Pi model 3B, a LoRa SX1276 transceiver and gas sensors. The sensors are intended to measure CO2, CH4, temperature, pressure and relative humidity. The collected data is then logged and sent to The Things Network (TTN) via a backhaul connection.
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Lin, Ismael. "Combining dense short range sensors and sparse long range sensors for mapping." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-223572.
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Mapping is one of the main components of autonomous robots, and consist in the construction of a model of their environment based on the information gathered by different sensors over time. Those maps will have different attributes depending on the type of sensor used for the reconstruction. In this thesis we focus on RGBD cameras and LiDARs. The acquired data with cameras is dense, but the range is short and the construction of large scale and consistent maps is more challenging. LiDARs are the exact opposite, they give sparse data but can measure long ranges accurately and therefore support large scale mapping better. The thesis presents a method that uses both types of sensors with the purpose of combine their strengths and reduce their weaknesses. The evaluation of the system is done in an indoor environment, and with an autonomous robot. The result of the thesis shows a map that is robust in large environments and has dense information of the surroundings.Kartläggning är en av huvudkomponenterna för autonoma robotar, och består av att bygga en modell av miljön utifrån informationen som samlats in av olika sensorer över tid. Dessa kartor kommer att ha olika attribut beroende på vilken typ av sensor som används för rekonstruktionen. I denna avhandling är fokus på RGBD-kameror och LiDARs. Datan från kameror är kompakt men kan bara mäta korta sträckor och det är utmanande att konstruera storskaliga och konsistenta kartor. LiDARs är exakt motsatta, de ger gles data men kan mäta långa avstånd noggrant och stödjer därför storskalig kartering bättre. Avhandlingen presenterar en metod som använder båda typerna av sensorer i syfte att kombinera deras styrkor och minska svagheterna. Utvärderingen av systemet sker i en inomhusmiljö och med en autonom robot. Resultatet av avhandlingen visar en karta som är robust i stora miljöer och har tät information om omgivningen.
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Abboud, Samira. "Study and improvement of long range communication technologies for wireless sensor networks." Thesis, Université Clermont Auvergne (2017-2020), 2020. http://www.theses.fr/2020CLFAC028.
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Les progrès des technologies de communication à faible consommation d’énergie et à faible cout ont révolutionne les applications de télédétection et de surveillance. L’Internet des objets (IoT) a promis la création d’un écosystème d’appareils connectes à travers un large éventail d’applications, telles que les villes intelligentes. A l’heure actuelle, de nombreuses normes et technologies concurrentes tentent de saisir l’IoT, en particulier dans le domaine des technologies de télédétection et de communication. LoRa (Long Range) est l’une de ces technologies qui gagne en popularité et en attraction dans les réseaux de capteurs sans fil (WSN). La possibilité d’établir des communications longue distance avec des nœuds relativement simples, une infrastructure minimale, des besoins en énergie réduits et l’utilisation de bandes ISM sans licence offre un avantage concurrentiel significatif. Bien que la portée de communication dans LoRa puisse dépasser 15 kilomètres en visibilité directe, le débit binaire maximal pouvant être atteint est limite à quelques kilobits par seconde. De plus, lorsqu’une collision se produit dans LoRa, le débit est encore réduit en raison de pertes de trames et de retransmissions. Les travaux de cette thèse traitent le problème des collisions dans LoRa qui peuvent survenir sous une charge importante et qui dégradent les performances du réseau.Premièrement, nous considérons le contexte des communications en liaison montante dans LoRaWAN. Nous étudions le contexte des signaux LoRa en collision synchronisée, ou chaque appareil terminal doit retransmettre toute sa trame en collision après qu’une collision se produit dans LoRa. Ce comportement diminue le débit global et augmente la consommation d’énergie des terminaux et le délai des trames. Pour cette raison, afin d’atténuer les effets néfastes des collisions, nous avons proposé un algorithme de décodage pour résoudre les signaux LoRa en collision synchronisée, dans un trafic réseau sature et confirme. Nous avons remplacé le modèle de retransmission conventionnel de LoRa en un modèle faisant en sorte que les dispositifs terminaux transmettent des bitmaps au lieu de retransmettre des trames entières pour déterminer les symboles corrects de chaque trame en collision. Notre algorithme a pu améliorer significativement le débit global de la couche LoRaWAN MAC à base de LoRa, et diminuer la consommation d’énergie des émetteurs et le délai des trames.Deuxièmement, nous considérons le contexte des communications en liaison descendante dans LoRaWAN. Nous avons remarqué que la liaison descendante dans LoRa est un goulot d’étranglements. Nous avons donc travaillé sur la sélection de la passerelle par le serveur de réseau et son impact sur le débit, la consommation d’énergie et le délai. Nous avons étudié trois types de déploiement de passerelle et nous avons montre que les performances du système dépendent de ce déploiement. Nous avons montré que l’équilibrage du nombre de terminaux par passerelle (également connu sous le nom de charge) améliore le débit par rapport au choix de la passerelle avec la meilleure qualité de signal. En outre, nous avons montré que la combinaison de la charge et de la qualité du signal n’améliore pas davantage le débit. De plus, nous avons montré que le choix de la passerelle avec la meilleure qualité de signal diminue le délai des trames et la consommation d’énergie des terminaux par rapport au choix de la passerelle avec la charge la plus faibleThe progress in low-energy, low-cost communication technologies have revolutionized remote sensing and monitoring applications. Internet of Things (IoT) has promised an ecosystem of connected devices across a wide range of applications such as in smart cities.Currently, many competing standards and technologies are attempting to seize the IoT, particularly in the area of remote sensing and communication technologies. LoRa (Long Range) is one of those technologies that is gaining popularity and attraction in the Wireless Sensor Networks (WSN) applications. The ability to make long-distance communications with relatively simple nodes, minimal infrastructure, reduced power requirements, and the use of unlicensed ISM bands provides a significant competitive advantage. Although the communication range in LoRa can exceed 15 kilometers in line of sight, the maximum bit rate that can be achieved is limited to few kilobits per second. Additionally, when a collision occurs in LoRa, the throughput is further reduced due to frame losses and retransmissions. The work of this thesis deals with the problem of collisions in LoRa that may occur under heavy load, and which degrade the performance of the network.First, we consider the context for LoRaWAN uplink communications. We study the context of fully synchronized colliding LoRa signals, where each end-device has to retransmit its entire colliding frame after a collision occurs in LoRa. This behavior decreases the overall throughput, and increases the energy consumption of the end-devices, and the delay of the frames. Therefore, in order to mitigate the damaging effects of collisions, we proposed a decoding algorithm to resolve synchronized colliding LoRa signals, in a saturated and confirmed network traffic. We substituted the conventional retransmission model of LoRa by having end-devices transmitting bitmaps instead of retransmitting whole frames to determine the correct symbols of each colliding frame. Our algorithm was able to significantly improve the overall throughput of the LoRaWAN MAC layer based on LoRa, and to decrease the energy consumption of the transmitters and the delay of the frames.Second, we consider the context for LoRaWAN downlink communications. We noticed that the downlink in LoRa is a bottleneck. Hence, we worked on the gateway selection by the network server and its impact on the throughput, the energy consumption and the delay. We studied three types of gateway deployment and we show that the system performance depends on this deployment. We showed that balancing the number of end-devices per gateway (also known as load) improves the throughput compared to choosing the gateway with the highest signal quality. Moreover, we showed that combining load and signal quality does not further improve the throughput. In addition, we showed that choosing the gateway with the highest signal quality decreases the delay and energy consumption compared to choosing the gateway with the lowest load
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Donipudi, Raghunandan K. "Self referencing SPR sensor by simultaneous excitation of long and short range surface plasmon modes." Lexington, Ky. : [University of Kentucky Libraries], 2006. http://lib.uky.edu/ETD/ukyelen2006t00468/RaghunandanDonipudi%5FMSThesis.pdf.
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Thesis (M.S.)--University of Kentucky, 2006.Title from document title page (viewed on August 22, 2006). Document formatted into pages; contains: x, 56 p. : ill. (some col.). Includes abstract and vita. Includes bibliographical references (p. 54-55).
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Ameri, Ahmed Abbas Hussein [Verfasser]. "Long-Range Ultra-Wideband Radar Sensor for Industrial Applications / Ahmed Abbas Hussein Ameri." Kassel : Kassel University Press, 2013. http://d-nb.info/1056897678/34.
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Mitchell, David. "A long-range spectroscopic methane leak sensor system using a high power raman amplifier." Thesis, University of Strathclyde, 2010. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=12841.
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Nassar, Ibrahim. "Long-Range, Passive Wireless Monitoring Using Energy-Efficient, Electrically-Small Sensor Nodes and Harmonic Radar Interrogator." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4923.
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This dissertation investigates the use of the harmonic radar technique for passive wireless sensing applications. Issues of DC power consumption, high RF activation power, large node size, and short communication range associated with the existing passive wireless sensing technologies are addressed by the development of novel, completely passive, high efficiency, compact 3-D harmonic sensor nodes. The node transceiver employs a passive frequency doubler to return the second harmonic of the interrogation signal, and electrically-small 3-D antennas to achieve the compactness and high efficiency. The developed nodes fit inside a sphere with a diameter < 3 cm and achieve communication range > 60 m using a 43 dBm EIRP interrogator. Effective modulation is demonstrated experimentally using low cost commercial vibration sensors. To address major challenges associated with long-range, embedded, passive wireless sensing including sensor node identification and remote channel calibration, a 3-D dual-channel transceiver is developed. To the best of the author's knowledge, the presented dual-channel transceiver is the first completely passive design with built-in passive remote channel calibration and identification capabilities, and the presented nodes have the best overall performance among previously published designs, in terms of conversion efficiency, communication range, and occupied volume. To reduce the cost and weight and improve the manufacturing process of the proposed nodes, the 3-D digital additive manufacturing and conformal direct printing technologies are employed.
The harmonic interrogator antenna design is also an underlying focus of this work. Different interrogator antenna candidates are developed based on different design approaches. The first approach is based on the use of dual-channel antenna array, where one channel is used for transmission and the second channel is used for reception. Two dual-channel harmonic interrogator antennas that consist of 4-element circular patch antenna arrays and 2-element quasi-Yagi dipole antenna arrays are implemented. The second approach employs mechanically reconfigurable antennas to reduce the size and maintain persistent radiation properties over wide frequency bandwidth. Two mechanical reconfiguration methods are developed; the first method is based on the use of Hoberman's planar foldable linkage to vary the operating frequency of planar circular patch antennas and the second mechanical reconfiguration method is based on the use of a rack and pinion mechanism to reconfigure dual-band slot antennas. The third approach employs a single channel multi-octave Vivaldi antenna to provide the capability to interrogate a large number of harmonic tags that are widely spaced in frequency. To improve the antenna radiation performance over a broad frequency range, a new method based on the introduction of a parasitic elliptical patch in the flare aperture is proposed. This method enables gain and bandwidth improvement compared to what has been reported for Vivaldi antennas with a compact size. To provide the interrogator the capability to steer the radiation beam for locating and tracking sensor nodes, a topology to develop a miniature, non-dispersive switchable 4-bit phase shifter is proposed on the basis of composite right/left handed transmission line unit cells.
Book chapters on the topic "Long range displacement sensor"
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Islam, Nabil, Fabien Ferrero, Leonardo Lizzi, Christophe Danchesi, and Stephane Boudaud. "Reconfigurable and Long-Range Wireless Sensor Node for Long Time Operation." In Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, 130–36. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-61563-9_11.
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Eroglu, Abdullah. "Long Range Wireless Data Acquisition Sensor System for Health Care Applications." In Applied Cyber-Physical Systems, 209–27. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-7336-7_16.
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Sun, Xiaoqiang, Yan Xu, Pierre Berini, and Daming Zhang. "Refractive Index Sensor Based on Long-Range Surface Plasmon Polariton Waveguide." In Lecture Notes in Electrical Engineering, 71–75. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-13-3381-1_13.
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Ryu, Bo, and Hua Zhu. "Long-Endurance Scalable Wireless Sensor Networks (LES-WSN) with Long-Range Radios for Green Communications." In Green IT: Technologies and Applications, 401–22. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-22179-8_21.
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Kirichek, Ruslan, and Vyacheslav Kulik. "Long-Range Data Transmission on Flying Ubiquitous Sensor Networks (FUSN) by Using LPWAN Protocols." In Communications in Computer and Information Science, 442–53. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-51917-3_39.
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Ali, Kharudin, Johnny Koh Siaw Paw, Damhuji Rifai, Nur Amalina Awang, Ahmed N. AbdAlla, Abdul Rahim Pazakadin, and Chong Kok Hen. "Long Range Ultrasonic Testing System Based on Lamb Wave Method for Validation an Optimized Piezoelectric Sensor Gap Array." In Proceedings of the 1st International Conference on Electronics, Biomedical Engineering, and Health Informatics, 205–17. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-33-6926-9_19.
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Gierecker, Johann, Daniel Schoepflin, Ole Schmedemann, and Thorsten Schüppstuhl. "Configuration and Enablement of Vision Sensor Solutions Through a Combined Simulation Based Process Chain." In Annals of Scientific Society for Assembly, Handling and Industrial Robotics 2021, 313–24. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-74032-0_26.
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Abstract Machine vision solutions can perform within a wide range of applications and are commonly used to verify the operation of production systems. They offer the potential to automatically record assembly states and derive information, but simultaneously require a high effort of planning, configuration and implementation. This generally leads to an iterative, expert based implementation with long process times and sets major barriers for many companies. Furthermore the implementation is task specific and needs to be repeated with every variation of product, environment or process. Therefore a novel concept of a simulation-based process chain for both—configuration and enablement—of machine vision systems is presented in this paper. It combines related work of sensor planning algorithms with new methods of training data generation and detailed task specific analysis for assembly applications.
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Samaitis, Vykintas, Elena Jasiūnienė, Pawel Packo, and Damira Smagulova. "Ultrasonic Methods." In Structural Health Monitoring Damage Detection Systems for Aerospace, 87–131. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-72192-3_5.
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AbstractUltrasonic inspection is a well recognized technique for non-destructive testing of aircraft components. It provides both local highly sensitive inspection in the vicinity of the sensor and long-range structural assessment by means of guided waves. In general, the properties of ultrasonic waves like velocity, attenuation and propagation characteristics such as reflection, transmission and scattering depend on composition and structural integrity of the material. Hence, ultrasonic inspection is commonly used as a primary tool for active inspection of aircraft components such as engine covers, wing skins and fuselages with the aim to detect, localise and describe delaminations, voids, fibre breakage and ply waviness. This chapter mainly focuses on long range guided wave structural health monitoring, as aircraft components require rapid evaluation of large components preferably in real time without the necessity for grouding of an aircraft. In few upcoming chapters advantages and shortcommings of bulk wave and guided wave ultrasonic inspection is presented, fundamentals of guided wave propagation and damage detection are reviewed, the reliability of guided wave SHM is discussed and some recent examples of guided wave applications to SHM of aerospace components are given.
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Yolcu, Cem, Magnus Herberthson, Carl-Fredrik Westin, and Evren Özarslan. "Magnetic Resonance Assessment of Effective Confinement Anisotropy with Orientationally-Averaged Single and Double Diffusion Encoding." In Mathematics and Visualization, 203–23. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-56215-1_10.
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AbstractPorous or biological materials comprise a multitude of micro-domains containing water. Diffusion-weighted magnetic resonance measurements are sensitive to the anisotropy of the thermal motion of such water. This anisotropy can be due to the domain shape, as well as the (lack of) dispersion in their orientations. Averaging over measurements that span all orientations is a trick to suppress the latter, thereby untangling it from the influence of the domains’ anisotropy on the signal. Here, we consider domains whose anisotropy is modeled as being the result of a Hookean (spring) force, which has the advantage of having a Gaussian diffusion propagator while still confining the spatial range for the diffusing particles. In fact, this confinement model is the effective model of restricted diffusion when diffusion is encoded via gradients of long durations, making the model relevant to a broad range of studies aiming to characterize porous media with microscopic subdomains. In this study, analytical expressions for the powder-averaged signal under this assumption are given for so-called single and double diffusion encoding schemes, which sensitize the MR signal to the diffusive displacement of particles in, respectively, one or two consecutive time intervals. The signal for one-dimensional diffusion is shown to exhibit power-law dependence on the gradient strength while its coefficient bears signatures of restricted diffusion.
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Shanyue Guan and Jennifer A. Bridge. "Continuous-wave radar sensor for structural displacement monitoring." In Short-Range Micro-Motion Sensing with Radar Technology, 245–90. Institution of Engineering and Technology, 2019. http://dx.doi.org/10.1049/pbce125e_ch10.
Full textConference papers on the topic "Long range displacement sensor"
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Khiat, A., F. Lamarque, C. Prelle, Ph Pouille, M. Leester-Schadel, and S. Buttgenbach. "Long-range displacement mini-sensor with submicrometric resolution." In 2006 5th IEEE Conference on Sensors. IEEE, 2006. http://dx.doi.org/10.1109/icsens.2007.355775.
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Arora, N., L. Petit, M. U. Khan, F. Lamarque, and C. Prelle. "Signal processing of a high resolution and long-range displacement sensor." In 2012 IEEE Sensors. IEEE, 2012. http://dx.doi.org/10.1109/icsens.2012.6411266.
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El Rawashdeh, Zeina, Philippe Revel, Christine Prelle, and Frédéric Lamarque. "Cones-assembled Grating for Long-range Fiber-optic Linear Displacement Sensor." In Special Session on Optical Sensors. SCITEPRESS - Science and and Technology Publications, 2015. http://dx.doi.org/10.5220/0005432001470155.
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Arora, N., L. Petit, M. U. Khan, F. Lamarque, and C. Prelle. "Algorithm for signal processing of long-range fiber optic displacement sensor." In 2012 9th France-Japan & 7th Europe-Asia Congress on Mechatronics (MECATRONICS) / 13th Int'l Workshop on Research and Education in Mechatronics (REM). IEEE, 2012. http://dx.doi.org/10.1109/mecatronics.2012.6451039.
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El Rawashdeh, Zeina, Philippe Revel, Christine Prelle, Pierrick Letort, and Frederic Lamarque. "Fiber-optic sensor for long range displacement measurement of a rotating spindle." In 2016 11th France-Japan & 9th Europe-Asia Congress on Mechatronics (MECATRONICS)/17th International Conference on Research and Education in Mechatronics (REM). IEEE, 2016. http://dx.doi.org/10.1109/mecatronics.2016.7547150.
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Rostami, A., M. Noshad, H. Hedayati, A. Ghanbari, and F. Janabi-Sharifi. "Design and modeling of fiber-optic displacement sensor with sub-nanometric resolution and long range." In International Symposium on Optomechatronic Technologies, edited by Sergej Fatikow, Farrokh Janabi-Sharifi, Toshio Fukuda, Hyungsuck Cho, and Heikki N. Koivo. SPIE, 2007. http://dx.doi.org/10.1117/12.754602.
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Chigullapalli, Aarti, and Jason V. Clark. "Towards a Self-Calibratable MEMS Absolute Temperature Sensor: A Theoretical Study." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-89208.
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In this paper, we present a theoretical description of a novel self-calibratable MEMS absolute temperature sensor. Our analysis suggests that the sensor might provide accurate and precise measurements over a large range of temperatures. Due to the high accuracy and precision required for some experiments and devices, such as studies involving fundamental laws or sensor drift due to thermal expansion, accurate temperature sensing is necessary. Conventional temperature sensors require factory calibration, which significantly increases the cost of manufacture. Using the equipartition theorem, nanotechnologists have long determined the stiffness of their atomic force microscope (AFM) cantilevers by measuring temperature and the cantilever’s displacement. Since we have determined how to measure MEMS stiffness, we propose that the reverse can be done, i.e. determine temperature by measuring MEMS stiffness and displacement. In this paper we describe our method for accurately and precisely measuring nonlinear stiffness and expected displacement. We also provide an expression for quantifying the uncertainty in measuring temperature.
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Stubbs, Jack David, and Muhammad Arslan Shahid. "Blade Tip Clearance Measurement Systems for High Speed Turbomachinery Applications and the Potential for Blade Tip Timing Applications." In ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/gt2020-15403.
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Abstract As turbomachinery OEMs focus efforts to further increase reliability, power and efficiencies, the running clearance between blade tips and stator continue to be of the utmost importance. This paper investigates the capability of capacitive tip clearance systems to perform individual blade tip clearance measurements on high speed rotors of up to 90,000rpm. A rotor was designed using finite element analysis; unique blade responses have been predicted. The objective of this investigation was to consider two different approaches to the application of blade tip clearance measurements and the system requirements to accurately measure low levels of radial displacement of a target rotating between 1,000rpm and 90,000rpm. The first uses the standard approach with passive probes and the second, a new technique using active probes that have demonstrated bandwidths of 1.2MHz and increased measuring range with a lower level of measurement uncertainty. Both systems’ approaches are compared, and their capabilities are evaluated for high-speed applications. The higher bandwidth capabilities of the latter system, combined with smaller sensor diameters, produces comparable signal rise times to the optical systems used in blade tip timing measurements. The difference in approach offers the potential of contamination resistant sensors for long term blade tip timing applications and measurement probes that do not require cooling systems to withstand higher temperature applications. The use of different probe configurations, in a number of applications, has demonstrated a two-fold improvement in the measurement range whilst producing lower levels of noise and uncertainty when applied to blade targets made from composites, aluminium and nickel-alloy materials. The measurement data presented includes individual blade’s radial displacement, identified shaft axial displacement, effects of resonance in the test system and the identification of the main drivers of measurement uncertainty along with an achievable value. The capacitive measurement systems’ performance for blade tip clearance is analysed and reported. The capability to perform other measurement techniques such as blade tip timing with a dual use measurement probe is also analysed and reported. This is done by correlating measurement results between the capacitive systems with that of a repeat measurement of the same target using an optical BTT system.
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Nabavi, Mohammad Reza, and Stoyan Nihtianov. "C1.4 - MHz-Range Interface for Inductive Displacement Sensors." In SENSOR+TEST Conferences 2009. AMA Service GmbH, Von-Münchhausen-Str. 49, 31515 Wunstorf, Germany, 2009. http://dx.doi.org/10.5162/sensor09/v1/c1.4.
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Becker, Fabian B., Martin A. Sehr, and Stephan Rinderknecht. "Gain-Scheduled ℋ∞-Control for Active Vibration Isolation of a Gyroscopic Rotor." In ASME 2015 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/smasis2015-9119.
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This paper deals with active vibration isolation of unbalance-induced oscillations in rotors using gain-scheduled H∞-controller via active bearings. Rotating machines are often exposed to gyroscopic effects, which occur due to bending deformations of rotors and the consequent tilting of rotor disks. The underlying gyroscopic moments are proportional to the rotational speed and couple the rotor’s radial degrees of freedom. Accordingly, linear time-varying models are well suited to describe the system dynamics in dependence on changing rotational speeds. In this paper, we design gain-scheduled H∞-controllers guaranteeing both robust stability and performance within a predefined range of operating speeds. The paper is based on a rotor test rig with two unbalance-induced resonances in its operating range. The rotor has two discs and is supported by one active and one passive bearing. The active support consists of two piezoelectric stack actuators and two collocated piezoelectric load washers. In addition, the rig is equipped with four inductive displacement sensors located at the discs. Closed-loop performance is assessed via isolation of unbalance-induced vibrations using both simulation and experimental data. This contribution is the next step on our path to achieving the long-term objective of combined vibration attenuation and isolation.
Reports on the topic "Long range displacement sensor"
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Moser, Paul M. Performance Predictions for a Long-Standoff-Range Infrared Imaging Sensor. Fort Belvoir, VA: Defense Technical Information Center, April 1992. http://dx.doi.org/10.21236/ad1012952.
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Avis, William. Refugee and Mixed Migration Displacement from Afghanistan. Institute of Development Studies (IDS), August 2021. http://dx.doi.org/10.19088/k4d.2022.002.
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This rapid literature review summarises evidence and key lessons that exist regarding previous refugee and mixed migration displacement from Afghanistan to surrounding countries. The review identified a diverse literature that explored past refugee and mixed migration, with a range of quantitative and qualitative studies identified. A complex and fluid picture is presented with waves of mixed migration (both outflow and inflow) associated with key events including the: Soviet–Afghan War (1979–1989); Afghan Civil War (1992–96); Taliban Rule (1996–2001); War in Afghanistan (2001–2021). A contextual picture emerges of Afghans having a long history of using mobility as a survival strategy or as social, economic and political insurance for improving livelihoods or to escape conflict and natural disasters. Whilst violence has been a principal driver of population movements among Afghans, it is not the only cause. Migration has also been associated with natural disasters (primarily drought) which is considered a particular issue across much of the country – this is associated primarily with internal displacement. Further to this, COVID-19 is impacting upon and prompting migration to and from Afghanistan. Data on refugee and mixed migration movement is diverse and at times contradictory given the fluidity and the blurring of boundaries between types of movements. Various estimates exist for numbers of Afghanistan refugees globally. It is also important to note that migratory flows are often fluid involving settlement in neighbouring countries, return to Afghanistan. In many countries, Afghani migrants and refugees face uncertain political situations and have, in recent years, been ‘coerced’ into returning to Afghanistan with much discussion of a ‘return bias’ being evident in official policies. The literature identified in this report (a mix of academic, humanitarian agency and NGO) is predominantly focused on Pakistan and Iran with a less established evidence base on the scale of Afghan refugee and migrant communities in other countries in the region. . Whilst conflict has been a primary driver of displacement, it has intersected with drought conditions and poor adherence to COVID-19 mitigation protocols. Past efforts to address displacement internationally have affirmed return as the primary objective in relation to durable solutions; practically, efforts promoted improved programming interventions towards creating conditions for sustainable return and achieving improved reintegration prospects for those already returned to Afghanistan.
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Collyer, Michael, Dolf te Lintelo, Thabani Mutambasere, and Tahir Zaman. Moving Targets: Social Protection as a Link Between Humanitarianism, Development and Displacement. Institute of Development Studies, June 2022. http://dx.doi.org/10.19088/basic.2022.017.
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Despite the widespread concern with social protection in the field of development, it has had little impact on displacement until very recently. UNHCR has had a Social Protection Unit since 2009, but social protection is barely mentioned in either the Global Compact on Refugees or the Global Compact for Safe, Orderly and Regular Migration, both agreed in 2018. The period since 2018 has seen a growth of research interest and new policy development. This represents the latest appearance of the humanitarian-development nexus in the field of displacement. This nexus is a long-standing one and is inherent in the term ‘durable solution’ as the only effective end of displacement. Unfortunately, there are few recognised successes, and durable solutions are enjoyed by only a tiny proportion of the growing number of displaced people in the world today. This makes renewed attention to the humanitarian-development nexus all the more urgent. In this paper we review the relationship between a humanitarian response to initial displacement and longer-term development planning, as well as the recent range of research and policy responses in this field. These demonstrate significant potential of social protection. We go on to consider six areas of developing theorisation in order to inform what would constitute success in the expanding inclusion of displaced people in social protection programmes or systems. We conclude with four suggestions where further research in this area can help to determine how and if the potential for social protection to offer more sustainable responses to displacement is being realised.
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Upadhyaya, Shrini K., Abraham Shaviv, Abraham Katzir, Itzhak Shmulevich, and David S. Slaughter. Development of A Real-Time, In-Situ Nitrate Sensor. United States Department of Agriculture, March 2002. http://dx.doi.org/10.32747/2002.7586537.bard.
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Although nitrate fertilizers are critical for enhancing crop production, excess application of nitrate fertilizer can result in ground water contamination leading to the so called "nitrate problem". Health and environmental problems related to this "nitrate problem" have led to serious concerns in many parts of the world including the United States and Israel. These concerns have resulted in legislation limiting the amount of nitrate N in drinking water to 10mg/g. Development of a fast, reliable, nitrate sensor for in-situ application can be extremely useful in dynamic monitoring of environmentally sensitive locations and applying site-specific amounts of nitrate fertilizer in a precision farming system. The long range objective of this study is to develop a fast, reliable, real-time nitrate sensor. The specific objective of this one year feasibility study was to explore the possible use of nitrate sensor based on mid-IR spectroscopy developed at UCD along with the silver halide fiber ATR (i.e. attenuated total internal reflection) sensor developed at TAU to detect nitrate content in solution and soil paste in the presence of interfering compounds. Experiments conducted at Technion and UCD clearly demonstrate the feasibility of detecting nitrate content in solutions as well as soil pastes using mid-IR spectroscopy and an ATR technique. When interfering compounds such as carbonates, bicarbonates, organic matter etc. are present special data analysis technique such as singular value decomposition (SYD) or cross correlation was necessary to detect nitrate concentrations successfully. Experiments conducted in Israel show that silver halide ATR fiber based FEWS, particularly flat FEWS, resulted in low standard error and high coefficient of determination (i.e. R² values) indicating the potential of the flat Fiberoptic Evanescent Wave Spectroscopy (FEWS) for direct determinations of nitrate. Moreover, they found that it was possible to detect nitrate and other anion concentrations using anion exchange membranes and M1R spectroscopy. The combination of the ion-exchange membranes with fiberoptices offers one more option to direct determination of nitrate in environmental systems.
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Burks, Thomas F., Victor Alchanatis, and Warren Dixon. Enhancement of Sensing Technologies for Selective Tree Fruit Identification and Targeting in Robotic Harvesting Systems. United States Department of Agriculture, October 2009. http://dx.doi.org/10.32747/2009.7591739.bard.
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The proposed project aims to enhance tree fruit identification and targeting for robotic harvesting through the selection of appropriate sensor technology, sensor fusion, and visual servo-control approaches. These technologies will be applicable for apple, orange and grapefruit harvest, although specific sensor wavelengths may vary. The primary challenges are fruit occlusion, light variability, peel color variation with maturity, range to target, and computational requirements of image processing algorithms. There are four major development tasks in original three-year proposed study. First, spectral characteristics in the VIS/NIR (0.4-1.0 micron) will be used in conjunction with thermal data to provide accurate and robust detection of fruit in the tree canopy. Hyper-spectral image pairs will be combined to provide automatic stereo matching for accurate 3D position. Secondly, VIS/NIR/FIR (0.4-15.0 micron) spectral sensor technology will be evaluated for potential in-field on-the-tree grading of surface defect, maturity and size for selective fruit harvest. Thirdly, new adaptive Lyapunov-basedHBVS (homography-based visual servo) methods to compensate for camera uncertainty, distortion effects, and provide range to target from a single camera will be developed, simulated, and implemented on a camera testbed to prove concept. HBVS methods coupled with imagespace navigation will be implemented to provide robust target tracking. And finally, harvesting test will be conducted on the developed technologies using the University of Florida harvesting manipulator test bed. During the course of the project it was determined that the second objective was overly ambitious for the project period and effort was directed toward the other objectives. The results reflect the synergistic efforts of the three principals. The USA team has focused on citrus based approaches while the Israeli counterpart has focused on apples. The USA team has improved visual servo control through the use of a statistical-based range estimate and homography. The results have been promising as long as the target is visible. In addition, the USA team has developed improved fruit detection algorithms that are robust under light variation and can localize fruit centers for partially occluded fruit. Additionally, algorithms have been developed to fuse thermal and visible spectrum image prior to segmentation in order to evaluate the potential improvements in fruit detection. Lastly, the USA team has developed a multispectral detection approach which demonstrated fruit detection levels above 90% of non-occluded fruit. The Israel team has focused on image registration and statistical based fruit detection with post-segmentation fusion. The results of all programs have shown significant progress with increased levels of fruit detection over prior art.
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Delwiche, Michael, Boaz Zion, Robert BonDurant, Judith Rishpon, Ephraim Maltz, and Miriam Rosenberg. Biosensors for On-Line Measurement of Reproductive Hormones and Milk Proteins to Improve Dairy Herd Management. United States Department of Agriculture, February 2001. http://dx.doi.org/10.32747/2001.7573998.bard.
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The original objectives of this research project were to: (1) develop immunoassays, photometric sensors, and electrochemical sensors for real-time measurement of progesterone and estradiol in milk, (2) develop biosensors for measurement of caseins in milk, and (3) integrate and adapt these sensor technologies to create an automated electronic sensing system for operation in dairy parlors during milking. The overall direction of research was not changed, although the work was expanded to include other milk components such as urea and lactose. A second generation biosensor for on-line measurement of bovine progesterone was designed and tested. Anti-progesterone antibody was coated on small disks of nitrocellulose membrane, which were inserted in the reaction chamber prior to testing, and a real-time assay was developed. The biosensor was designed using micropumps and valves under computer control, and assayed fluid volumes on the order of 1 ml. An automated sampler was designed to draw a test volume of milk from the long milk tube using a 4-way pinch valve. The system could execute a measurement cycle in about 10 min. Progesterone could be measured at concentrations low enough to distinguish luteal-phase from follicular-phase cows. The potential of the sensor to detect actual ovulatory events was compared with standard methods of estrus detection, including human observation and an activity monitor. The biosensor correctly identified all ovulatory events during its testperiod, but the variability at low progesterone concentrations triggered some false positives. Direct on-line measurement and intelligent interpretation of reproductive hormone profiles offers the potential for substantial improvement in reproductive management. A simple potentiometric method for measurement of milk protein was developed and tested. The method was based on the fact that proteins bind iodine. When proteins are added to a solution of the redox couple iodine/iodide (I-I2), the concentration of free iodine is changed and, as a consequence, the potential between two electrodes immersed in the solution is changed. The method worked well with analytical casein solutions and accurately measured concentrations of analytical caseins added to fresh milk. When tested with actual milk samples, the correlation between the sensor readings and the reference lab results (of both total proteins and casein content) was inferior to that of analytical casein. A number of different technologies were explored for the analysis of milk urea, and a manometric technique was selected for the final design. In the new sensor, urea in the sample was hydrolyzed to ammonium and carbonate by the enzyme urease, and subsequent shaking of the sample with citric acid in a sealed cell allowed urea to be estimated as a change in partial pressure of carbon dioxide. The pressure change in the cell was measured with a miniature piezoresistive pressure sensor, and effects of background dissolved gases and vapor pressures were corrected for by repeating the measurement of pressure developed in the sample without the addition of urease. Results were accurate in the physiological range of milk, the assay was faster than the typical milking period, and no toxic reagents were required. A sampling device was designed and built to passively draw milk from the long milk tube in the parlor. An electrochemical sensor for lactose was developed starting with a three-cascaded-enzyme sensor, evolving into two enzymes and CO2[Fe (CN)6] as a mediator, and then into a microflow injection system using poly-osmium modified screen-printed electrodes. The sensor was designed to serve multiple milking positions, using a manifold valve, a sampling valve, and two pumps. Disposable screen-printed electrodes with enzymatic membranes were used. The sensor was optimized for electrode coating components, flow rate, pH, and sample size, and the results correlated well (r2= 0.967) with known lactose concentrations.
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Belkin, Shimshon, Sylvia Daunert, and Mona Wells. Whole-Cell Biosensor Panel for Agricultural Endocrine Disruptors. United States Department of Agriculture, December 2010. http://dx.doi.org/10.32747/2010.7696542.bard.
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Objectives: The overall objective as defined in the approved proposal was the development of a whole-cell sensor panel for the detection of endocrine disruption activities of agriculturally relevant chemicals. To achieve this goal several specific objectives were outlined: (a) The development of new genetically engineered wholecell sensor strains; (b) the combination of multiple strains into a single sensor panel to effect multiple response modes; (c) development of a computerized algorithm to analyze the panel responses; (d) laboratory testing and calibration; (e) field testing. In the course of the project, mostly due to the change in the US partner, three modifications were introduced to the original objectives: (a) the scope of the project was expanded to include pharmaceuticals (with a focus on antibiotics) in addition to endocrine disrupting chemicals, (b) the computerized algorithm was not fully developed and (c) the field test was not carried out. Background: Chemical agents, such as pesticides applied at inappropriate levels, may compromise water quality or contaminate soils and hence threaten human populations. In recent years, two classes of compounds have been increasingly implicated as emerging risks in agriculturally-related pollution: endocrine disrupting compounds (EDCs) and pharmaceuticals. The latter group may reach the environment by the use of wastewater effluents, whereas many pesticides have been implicated as EDCs. Both groups pose a threat in proportion to their bioavailability, since that which is biounavailable or can be rendered so is a priori not a threat; bioavailability, in turn, is mediated by complex matrices such as soils. Genetically engineered biosensor bacteria hold great promise for sensing bioavailability because the sensor is a live soil- and water-compatible organism with biological response dynamics, and because its response can be genetically “tailored” to report on general toxicity, on bioavailability, and on the presence of specific classes of toxicants. In the present project we have developed a bacterial-based sensor panel incorporating multiple strains of genetically engineered biosensors for the purpose of detecting different types of biological effects. The overall objective as defined in the approved proposal was the development of a whole-cell sensor panel for the detection of endocrine disruption activities of agriculturally relevant chemicals. To achieve this goal several specific objectives were outlined: (a) The development of new genetically engineered wholecell sensor strains; (b) the combination of multiple strains into a single sensor panel to effect multiple response modes; (c) development of a computerized algorithm to analyze the panel responses; (d) laboratory testing and calibration; (e) field testing. In the course of the project, mostly due to the change in the US partner, three modifications were introduced to the original objectives: (a) the scope of the project was expanded to include pharmaceuticals (with a focus on antibiotics) in addition to endocrine disrupting chemicals, (b) the computerized algorithm was not fully developed and (c) the field test was not carried out. Major achievements: (a) construction of innovative bacterial sensor strains for accurate and sensitive detection of agriculturally-relevant pollutants, with a focus on endocrine disrupting compounds (UK and HUJ) and antibiotics (HUJ); (b) optimization of methods for long-term preservation of the reporter bacteria, either by direct deposition on solid surfaces (HUJ) or by the construction of spore-forming Bacillus-based sensors (UK); (c) partial development of a computerized algorithm for the analysis of sensor panel responses. Implications: The sensor panel developed in the course of the project was shown to be applicable for the detection of a broad range of antibiotics and EDCs. Following a suitable development phase, the panel will be ready for testing in an agricultural environment, as an innovative tool for assessing the environmental impacts of EDCs and pharmaceuticals. Furthermore, while the current study relates directly to issues of water quality and soil health, its implications are much broader, with potential uses is risk-based assessment related to the clinical, pharmaceutical, and chemical industries as well as to homeland security.