Search results for "010401 analytical chemistry"
showing 10 items of 1284 documents
Monolithic integration of GMR sensors for standard CMOS-IC current sensing
2017
Abstract In this work we report on the development of Giant Magnetoresistive (GMR) sensors for off-line current measurements in standard integrated circuits. An ASIC has been specifically designed and fabricated in the well-known AMS-0.35 μm CMOS technology, including the electronic circuitry for sensor interfacing. It implements an oscillating circuit performing a voltage-to-frequency conversion. Subsequently, a fully CMOS-compatible low temperature post-process has been applied for depositing the GMR sensing devices in a full-bridge configuration onto the buried current straps. Sensitivity and resolution of these sensors have been investigated achieving experimental results that show a de…
Towards a cyber-physical era: soft computing framework based multi-sensor array for water quality monitoring
2018
Abstract. New concepts and techniques are replacing traditional methods of water quality parameter measurement systems. This paper introduces a cyber-physical system (CPS) approach for water quality assessment in a distribution network. Cyber-physical systems with embedded sensors, processors and actuators can be designed to sense and interact with the water environment. The proposed CPS is comprised of sensing framework integrated with five different water quality parameter sensor nodes and soft computing framework for computational modelling. Soft computing framework utilizes the applications of Python for user interface and fuzzy sciences for decision making. Introduction of multiple sen…
Non-destructive analytical methods to study the conservation state of Apadana Hall of Persepolis.
2015
Atmospheric and biological agents are the main enemies of the building material conservation. In this work an innovative methodological approach, based on Near Infrared Spectroscopy (NIR) and X-Ray Fluorescence Spectroscopy (XRF), has been employed to evaluate the conservation state of Persepolis limestone samples collected both, under a protective shelter and outside the shelter, at Apadana Audience Hall area in Persepolis. The use of NIR spectra permitted to discriminate, by using Principal Component Analysis (PCA), the differences between samples collected inside and outside the protective shelter and we have been able to identify a major degradation state of the out shelter stone sample…
Video-Based Heartbeat Rate Measuring Method Using Ballistocardiography
2017
International audience; Video-based heartbeat rate measurement is a rapidly growing application in remote health monitoring. Video-based heartbeat rate measuring methods operate mainly by estimating photoplethysmography or ballistocardiography signals. These methods operate by estimating the microscopic color change in the face or by estimating the microscopic rigid motion of the head/facial skin. However, the robustness to motion artifacts caused by illumination variance and motion variance of the subject poses main challenge. We present a video-based heartbeat rate measuring framework to overcome these problems by using the principle of ballistocardiography. In this paper, we proposed a b…
Electronic noses and tongues to assess food authenticity and adulteration
2016
Abstract Background There is a growing concern for the problem of food authenticity assessment (and hence the detection of food adulteration), since it cheats the consumer and can pose serious risk to health in some instances. Unfortunately, food safety/integrity incidents occur with worrying regularity, and therefore there is clearly a need for the development of new analytical techniques. Scope and approach In this review, after briefly commenting the principles behind the design of electronic noses and electronic tongues, the most relevant contributions of these sensor systems in food adulteration control and authenticity assessment over the past ten years are discussed. It is also remar…
E-Nose Application to Food Industry Production
2016
Food companies worldwide must constantly engage in product development to stay competitive, cover existing markets, explore new markets, and meet key consumer requirements. This ongoing development places high demands on achieving quality at all levels, particularly in terms of food safety, integrity, quality, nutrition, and other health effects. Food product research is required to convert the initial product idea into a formulation for upscaling production with ensured significant results. Sensory evaluation is an effective component of the whole process. It is especially important in the last step in the development of new products to ensure product acceptance. In that stage, measurement…
Recent advances on intelligent packaging as tools to reduce food waste
2018
[EN] Food waste is one of the main issues for international organisms. It is not only an ethical and economic issue but it also depletes the environment of limited natural resources. Among strategies suitable for fighting such challenge, intelligent packaging is an interesting tool to reduce waste derived from households and retailers. A revision of 45 recent advances in the area of optical systems for freshness monitoring is reported herein. The study covers fruits, vegetables, fish products and meat since they are the most representative fields of application. Furthermore, a discussion about the main research challenges and opportunities that will be faced by intelligent packaging in the …
Aggregated Packet Transmission in Duty-Cycled WSNs: Modeling and Performance Evaluation
2017
[EN] Duty cycling (DC) is a popular technique for energy conservation in wireless sensor networks (WSNs) that allows nodes to wake up and sleep periodically. Typically, a single-packet transmission (SPT) occurs per cycle, leading to possibly long delay. With aggregated packet transmission (APT), nodes transmit a batch of packets in a single cycle. The potential benefits brought by an APT scheme include shorter delay, higher throughput, and higher energy efficiency. In the literature, different analytical models have been proposed to evaluate the performance of SPT schemes. However, no analytical models for the APT mode on synchronous DC medium access control (MAC) mechanisms exist. In this …
Measuring low H field and currents with AMR sensors
2017
The growing demand from the automotive industry for high accuracy magnetic sensors and the need to perform high resolution angular position measurements have been the drivers for the industrial research in magnetic sensing technologies. This paper describes the design and characterization of several experimental devices implementing simple magnetoresistive structures targeting contactless current measurement in the tens to hundreds of milliamps range with sub-mA resolution. The ultimate goal is to extend the application area of magnetoresistive sensors beyond their current niche in automotive into more general applications. The initial set of devices tested to-date has shown a sensitivity o…
A Multi-Position Calibration Method for Consumer-Grade Accelerometers, Gyroscopes, and Magnetometers to Field Conditions
2017
This paper presents a calibration method for consumer-grade accelerometers, gyroscopes, and magnetometers. Considering the calibration of consumer-grade sensors, it is essential that no specialized equipment is required to create reference signals. In addition, the less is required from the reference signals, the more suitable the method is on the field. In the proposed method, the novelty in the calibration of the gyroscopes lies in the exploitation of only the known net rotations between the positions in a multi-position calibration. For accelerometers and magnetometers, the innovation is that the direction of reference signals, the gravity and the magnetic field of the Earth, are estimat…