Sensor

Zeptogram sensing from gigahertz vibration: Graphene based nanosensor

by Rajib Chowdhury

Physica E: Low-dimensional Systems and Nanostructures

We develop the mathematical framework for using single layer graphene sheet as nanoscale label-free mass sensors.... more We develop the mathematical framework for using single layer graphene sheet as nanoscale label-free mass sensors. Graphene resonators are assumed to be in the cantilevered configuration. Four types of mass loadings are considered and closed-form equations are derived for the frequency shift due to the added mass. Using the potential and kinetic energy of the mass loaded graphene sheets, generalised non-dimensional calibration constants are proposed for an explicit relationship between the added mass and the frequency shift. These equations in turn are used for sensing the added mass. Numerical results illustrate that the sensitivity of graphene sensors is in the order of gigahertz/zeptogram. We show that the performance of the sensor depends on the spatial distribution of the attached mass on the graphene sheet.

Surface resistance experiments with IPMC sensors and actuators

by Maarja Kruusmaa

Response Surface Models to Detect and Localize Distributed Cracks in a Complex Continuum

by Sara Casciati

Casciati S. (2010). “Response surface models to detect and localize distributed cracks in a complex continuum”. Journal of Engineering Mechanics – ASCE, 136(9), 1131-1142. ISSN: 0733-9399.

DATE AND PLACE OF PUBLICATION: September 2010; ASCE – American Society of Civil Engineers, Reston, VA 20191-4400, USA.

ABSTRACT:Linear response surface
RS models are used to represent the relationship between samples of response time... more ABSTRACT:Linear response surface
RS models are used to represent the relationship between samples of response time histories measured by sensors placed across a structure. Different structural states of a general time-variant system are considered for short intervals capturing a linearized model of each state. Within this framework, the error associated with each RS model is sensitive to a modification of the structural state. A method that relates the changes of the statistical characterization of the error to the occurrence of a structural modification is developed for damage detection. The localization of damage is then pursued by identifying the largest discrepancies resulting from the comparison between the statistics of the sum of the squares of the error obtained at each sensor location. The generality of the method is shown by applying it to the experimental data of a realistic structure, which is representative of a continuous body affected by distributed cracking.

KEYWORDS: Dynamics; Vibration; Structural response; Statistics; Damage; Monitoring; Masonry; Cracking

Study of Water Speed Sensitivity in a Multifunctional Thick-film Sensor by Analytical Thermal Simulations and Experiments

by Paolo Emilio Bagnoli

A multifunctional (temperature, liquid flow, pressure and electrical conductivity) thick film sensor for monitoring... more A multifunctional (temperature, liquid flow, pressure and electrical conductivity) thick film sensor for monitoring water pipelines is here presented. This work is mainly focused on the theoretical and experimental characterization of the water flow sensitivity based on a planar version of the well-known hot-wire anemometer. The simulations of the temperature displacement on the sensor surface under several electrical biases and heat convection conditions were performed by means of the fast analytical thermal simulator DJOSER, thus providing an example of the capability and the utility of this simulation program. The calculated sensitivity curves to the heat convection coefficient and/or to the water speed were found to be in agreement with the experimental data measured on the sensor mounted within a closed pipeline which allows changing the water speed until 1000 liters/hour.

Sensor World: A New Approach to Incorporating Large-Scale Sensor Data into Engineering Learning Environments

by Hanjun Xian

published in 'Computers in Education Journal'

Novel high bandwidth wall shear stress sensor for ultrasonic cleaning applications

by Firdaus Prabowo

Automatic sensation: environmental sensors in the digital city

by Jennifer Gabrys

Published in a special issue of “Senses and the City,” The Senses and Society, edited by Mags Adams and Simon Guy, Vol. 2, Issue 2 (July 2007), 189-200.

This paper discusses the use of environmental sensors, wireless networks and mobile media as technologies of sensation... more 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. 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.

A New Method for Monitoring Ammonium Nitrate Contamination in Natural Water Sources Based on Independent Component Analysis

by Mohd Amri Bin Md Yunus

POSTER:IEEE Sensors 2011Conference, Limerick, Limerick, Ireland 28-3th October.

Application of Independent Component Analysis for Estimating Nitrate Contamination in Natural Water Sources Using Planar Electromagnetic Sensor

by Mohd Amri Bin Md Yunus

M. A. Md Yunus, S. C. Mukhopadhyay, and A. D. Punchihewa “Application of Independent Component Analysis for Estimating Nitrate Contamination in Natural Water Sources Using Planar Electromagnetic Sensor”. ICST2011, Palmerston North, New Zealand. 28th Nov to 1th Dec 2011. (Final paper will be added when the conference commenced)

A system that measures impedance of a planar electromagnetic sensor is described in this paper. It has been used to... more A system that measures impedance of a planar electromagnetic sensor is described in this paper. It has been used to estimate the amount of nitrate contamination in water samples with the assistance of a method based on independent component analysis. Nitrates sample in the form of ammonium nitrates (NH4NO3), each of different concentration between 5 mg and 20 mg dissolved in 1 litre of deionized water (mili-q) was used as one of the main references. A model based on independent component analysis was developed to estimate nitrate contamination. The model was tested with eight sets of mixed NH4NO3 and (NH4)2HPO4 water samples. From the results, the model can acceptably detect the presence of nitrate added in distilled water and capable of distinguishing the concentration level in the presence of other type of contamination. The system and approach presented in this paper has the potential to be used as a useful tool for water sources monitoring.

A New Method for Monitoring Ammonium Nitrate Contamination in Natural Water Sources Based on Independent Component Analysis

by Mohd Amri Bin Md Yunus

M. A. M. Yunus and S. C. Mukhopadhyay . “A New Method for Monitoring Ammonium Nitrate Contamination in Natural Water Sources Based on Independent Component Analysis”. IEEE Sensors 2011, Limerick, Limerick, Ireland 28-3th October.

A system that measures impedance of a novel planar electromagnetic sensor successfully estimated the amount of... more A system that measures impedance of a novel planar electromagnetic sensor successfully estimated the amount of ammonium and nitrate contaminations in natural water sources with the use of independent component analysis. The system employs a planar electromagnetic sensor which is simple to construct, reliable, and low cost. In this paper we have reported the achievement of extending the detecting capabilities of the sensor using independent component analysis to estimate ammonium nitrate contamination in water sources supply with good accuracy. The outcomes show a very good estimation of contamination level with the output response of the sensor and independent component analysis method.

Development of a low-cost system for nitrate and contamination detections in natural water supply based on a planar electromagnetic sensor

by Mohd Amri Bin Md Yunus

M. A. M. Yunus, G. R. Mendez, and S. C. Mukhopadhyay, "Development of a low-cost system for nitrate and contamination detections in natural water supply based on a planar electromagnetic sensor," in Instrumentation and Measurement Technology Conference (I2MTC), 2011 IEEE, Hangzhou, Republic of China, 10-12 Mayth 2011, pp. 1-6.

The main objective of the present work is to develop a low-cost system for detection of nitrate and contamination in... more The main objective of the present work is to develop a low-cost system for detection of nitrate and contamination in natural water resources based on a planar electromagnetic sensor. The functions and attributes of the low cost system based on planar meander and interdigital structure are discussed. The performance of the system was observed where the sensor was tested with two aqueous solutions of nitrates forms namely, sodium nitrates (NaNO3) and ammonium nitrates (NH4NO3 Keywords-component; low cost system; nitrate detection; contamination detection; planar electromagnetic sensors; style;
water supply;), each of different concentration between 5 mg and 20 mg dissolved in 1 litre of mili-q water. Furthermore, it was also tested with various kinds of natural water samples taken from natural sources around New Zealand. The results from the first set of experiments show good linear correlations with the amount of concentration of nitrate forms in mili-q water. Favourably, the second experiment’s outcomes involving the water sample taken from various places around New Zealand also show a good correlation of contamination level as compared with results obtained from Nuclear Magnetic Resonance (NMR) measurement. The improvements for future consideration are also discussed.

Novel Planar Electromagnetic Sensors for Detection of Nitrates and Contamination in Natural Water Sources

by Mohd Amri Bin Md Yunus

M. A. M. Yunus and S. C. Mukhopadhyay, "Novel Planar Electromagnetic Sensors for Detection of Nitrates and Contamination in Natural Water Sources," Sensors Journal, IEEE, vol. 11, pp. 1440-1447, 19th April 2011.

This paper introduces novel sensors based on the combination of planar meander and interdigital electromagnetic... more This paper introduces novel sensors based on the combination of planar meander and interdigital electromagnetic sensors for monitoring the level of contamination in water sources. A series of experiments was conducted to determine the sensors characteristics.Two nitrates forms, namely sodium nitrates and ammonium nitrates, were mixed in several different ratios dissolved in 1 L of distilled water and were used to observe the response of the sensors. Initial results show that the sensors can detect very well the presence of nitrate added in distilled water. Furthermore, the contamination level of water samples which were taken from various sources and locations in New Zealand have been determined using the sensor, and the results was compared with the results obtained using nuclear magnetic resonance (NMR) technique. The outcomes show a very good correlation of contamination level with the output response of the sensor. The work and improvement for future consideration are discussed in this paper.

A Review of Material Properties Estimation Using Eddy Current Testing and Capacitive Imaging

by Mohd Amri Bin Md Yunus

M. A. Md Yunus, S. C. Mukhopadhyay, and G. Sen Gupta, "A Review of Material Properties Estimation Using Eddy Current Testing and Capacitive Imaging," Sensors & Transducers Journal, vol. 100, pp.92-115, January 2009.

The non destructive testing applications based on inductive (eddy current testing) and capacitive sensors are widely... more The non destructive testing applications based on inductive (eddy current testing) and capacitive sensors are widely used for imaging of material properties. The simple structure, safe to use, low cost, non contact application, good response at medium range frequency of the sensors make them preferable to be used in the industries. The aim of this study is to talk about the material properties estimation applications using eddy current testing and capacitive sensing. The basic operations of eddy
current testing and capacitive sensing with example of application in the non destructive testing are discussed. Next, the recent advancements of eddy current testing and capacitive testing in imaging technique are presented in this paper

Planar Electromagnetic Sensor for the Detection of Nitrate and Contamination in Natural Water Sources Using Electrochemical Impedance Spectroscopy Approach

by Mohd Amri Bin Md Yunus

M. A. M. Yunus and S. C. Mukhopadhyay, "Planar Electromagnetic Sensor for the Detection of Nitrate and Contamination in Natural Water Sources Using Electrochemical Impedance Spectroscopy Approach," in New Developments and Applications in Sensing Technology. vol. 83, S. C. Mukhopadhyay, A. Lay-Ekuakille, and A. Fuchs, Eds., ed: Springer Berlin Heidelberg, 2011, pp. 39-63.

This paper highlights the progress of developing a low-cost system for detection of nitrate and contamination in... more This paper highlights the progress of developing a low-cost system for detection of nitrate and contamination in natural water resources based on a planar electromagnetic sensor which consists of meander and interdigital structure. The sensor has been operated and evaluated using electrochemical impedance spectroscopy (EIS) approach, based on estimated electrical model; the results obtained from the experiments were interpreted. The objectives of the present work are to conduct simulation, experiments and analysis of a new nitrate detection method using novel planar electromagnetic sensors by means of electrochemical spectroscopy analysis. The sensor was tested with two aqueous solutions of nitrates forms namely, sodium nitrates (NaNO3) and ammonium nitrates (NH4NO3), each of different concentration between 5 mg and 20 mg dissolved in 1 litre of distilled water to observe their response. Furthermore, the sensor was tested with various kinds of prepared samples and natural water samples taken from natural sources around New Zealand. The simulation results using COMSOL have assisted in understanding the characteristic and response of the sensor to the change of properties in the aqueous solution. The experimental results have authenticated the results obtained from the simulation and show the sensor can well detect the presence of nitrate added in distilled water and distinguish the concentration level from the calculated sensitivities. The experiment results with the water sample taken from various places around New Zealand show a very good correlation of contamination level, translated from the qualitative and quantitative results. The work and improvement for future consideration are also discussed in this chapter.

Imaging of solid flow in a gravity flow rig using infra-red tomography

by Mohd Amri Bin Md Yunus

Sheep skin property estimation using a low-cost planar sensor

by Mohd Amri Bin Md Yunus

Interdigital sensors have been successfully employed in various fields; in this paper we attempted to determine the... more Interdigital sensors have been successfully employed in various fields; in this paper we attempted to determine the looseness in sheep skins using interdigital sensors. Looseness is one of the quality attributes that determines the value of the leather. A low cost interdigital based sensing system with an effective data acquisition system has been designed.

The cephalic median organ of trilobites.

by Rudy Lerosey-Aubril

LEROSEY-AUBRIL R. & MCNAMARA K.J. 2008. The cephalic median organ of trilobites. In: I.Rabano, R. Gozalo and D. Garcia-Bellido (Eds.), Advances in trilobite research, 229-235. Cuadernos del Museo Geominero, 9. Instituto Geologico y Minero de Espana, Madrid.

SensorWorld: Unified Touch-Based Access to Sensors Worldwide

by Hanjun Xian

Dew-based Wireless Mini Module for Respiratory Rate Monitoring

by Laurent Francis

Co authored by Andre, N.;  Druart, S.;  Dupuis, P.;  Rue, B.;  Gerard, P.;  Flandre, D.;  Raskin, J.;  and Francis, L..

Miniaturized humidity sensors combined with ZigBee transceiver and efficient data processing offer a powerful system... more Miniaturized humidity sensors combined with ZigBee transceiver and efficient data processing offer a powerful system for the monitoring of human breath. Every 10 ms, the expiration/inspiration phase is transmitted, allowing a medical diagnosis as efficient as required by the application. For the sensing system, a micro interdigitated capacitor, covered with a dense hydrophilic alumina layer, is connected to a capacitance-to- frequency circuit interface. A customized nasal canulaprototype embeds the microsystem underneath the patient's nostrils while offering cabling until the belt-fixed radio transceiver. The fast data processing, executed in a mini notebook process unit, gives to the medical staff a live broadcast of the patient's respiratory rate. In order to improve the size and the functionality of our sensing module, novel techniques for processing complementary metal oxide semiconductor (CMOS) in Silicon-on-Insulator (SOI) technology now allow for the construction of microsensors and CMOS circuits together on the same chip. These sensors consume extremely low power, of the order of 0.1 ìW, present high sensitivity, occupy small chip area (1.25 mm2) and offer the prerequisite platform for a large variety of new sensors.

Measuring the effectiveness of bad pixel detection algorithms using the ROC curve

by Vittal Premachandran