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JournalISSN: 0924-4247

Sensors and Actuators A-physical 

About: Sensors and Actuators A-physical is an academic journal. The journal publishes majorly in the area(s): Silicon & Actuator. It has an ISSN identifier of 0924-4247. Over the lifetime, 12940 publication(s) have been published receiving 362805 citation(s).
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Journal ArticleDOI
Kyeong-Rak Lee1, Yong-Jun Kim1Institutions (1)
Abstract: Air pollutants can cause a variety of environmental and health problems, and several epidemiological and clinical studies have investigate the association of diseases with air pollution. Air pollutants include fine particles and ultrafine particles, which show complex aspects depending on time and space. Therefore, a portable system for measuring fine particles is required. In this study, we developed a portable system to measure the number concentration, mass concentration, and effective density of PM10, which are important measures of fine particles. Current devices used to measure the effective density of particles are either large or only able to measure target particles at the nanoscale. In this study, an Optical Particle Counter (OPC) and a one-stage Quartz Crystal Microbalance (QCM) impactor were used to compose a PM10 multilateral measurement system to calculate the effective density of PM10. OPC is a small device that measures the number concentration of particles, and the QCM impactor measures the mass concentration of particles. Currently available QCM impactors for particle measurement are large devices. Therefore, we miniaturized it in the form of a one-stage impactor. The QCM was installed on an impaction plate to collect the particles. Through the developed system, the number and mass concentrations of input particles were simultaneously measured, and their effective density was calculated using the measured concentrations. Finally, outdoor air monitoring was performed, and the obtained measurements were validated by comparing them with the measurements of reference devices. A difference of 4.7% and 11% were obtained for mass and number concentrations, respectively. Therefore, the effective density of PM10 was successfully calculated.

Journal ArticleDOI
Debeshi Dutta1, Dwipjyoti Natta2, Soumen Mandal3, Soumen Mandal1  +1 moreInstitutions (3)
Abstract: Continuous activity monitoring of dairy cattle is essential to acquire a comprehensive knowledge on health and well-being of the animals. In this research, we have reported the development and deployment of "MOOnitor", a neck-mounted intelligent IoT device for cattle monitoring. The device facilitates classification of salient activities of cattle through appropriately positioned sensors. MOOnitor is an integration of a temperature sensor, a global positioning system (GPS) module, and a 3-axis accelerometer in a lightweight enclosure, which is attached to a halter that allows transmission of data to an IoT server using a microcontroller and a cellular GSM module. After acquiring the necessary sensory information, the most significant features were strategically extracted for enhanced data interpretation. Thereafter, optimally tuned eXtreme Gradient Boosting (XGBoost) and Random Forests classifiers were implemented to classify activities like ‘standing’, ‘lying’, ‘standing and ruminating’, ‘lying and ruminating’, ‘walking’, and ‘walking and grazing’. The performances of the two classifiers towards identification of different cattle activities were compared in terms of accuracy. Furthermore, the importance of using a temperature sensor and a GPS module in addition to an accelerometer in cattle activity recognition could be justified. An overall classification accuracy as high as ~97% was achieved using the XGBoost based classifier. In addition, accuracy, precision, sensitivity and specificity for standing (0.98, 0.97, 0.97, 0.98), lying (0.97, 0.90, 1, 0.96), standing and ruminating (0.99, 1, 0.97, 1), lying and ruminating (0.99, 1, 0.83, 1), walking (1, 1, 1, 1), and walking and grazing (0.99, 1, 0.75, 1) shows the suitability of the proposed method in effective cattle activity monitoring. Since cattle activity states are indicative of various factors such as estrous and several diseases like mastitis, foot-and-mouth disease, etc, the MOOnitor may be used for early detection of these conditions in addition to general health monitoring.

Journal ArticleDOI
Yongcun Hao1, Chenggang Wang1, Zheng Sun1, Zhao Zhang1  +2 moreInstitutions (1)
Abstract: This paper reports a DC electric field sensor (EFS) based on the mode localization phenomenon. The EFS consists of 3-degrees-of-freedom weakly coupled resonators (WCRs) and two capacitor arrays that are electrostatically coupled with the WCRs. The capacitor arrays sense the electric field and produce a stiffness perturbation that causes an amplitude ratio change of the WCRs. The EFS is fabricated using a silicon-on-insulator process and evaluated in a vacuum chamber. The amplitude ratio of the resonators changes from 2.2 to 7.5 as the electric field strength ranges from 0 to 7 kV/m, with a sensitivity of 0.76 /(kV/m). The noise, resolution, and stability of the mode-localized EFS are 11.5 (V/m)/√Hz, 22.9 V/m, and 9.1 V/m, respectively, which are competitive compared with that of other high-performance micromachined EFS.

Journal ArticleDOI
Abstract: In the present work, we report an excellent gas sensing performance of the unique nanocomposite films prepared with the help of different materials such as semiconductor metal-oxide, polymer and metal for carbon monoxide gas sensing at ambient temperature. The fabrication of SnO2/PANI/Pd nanocomposite film was performed using the hydrothermal route. The fabricated films were characterized with various analytical techniques such as X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM), and Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) etc. Furthermore, DFT results are used to examine the transport and electronic properties of all prepared films. The computing results show that after hybridizing with Pd and SnO2, the response of the fabricated SnO2 and polyaniline (PANI) films to CO gas molecules is considerably improved. At room temperature, sensing characterization of the fabricated sensing films was carried out by using target gas concentrations with varying ppm level of 50–300. At ambient temperature, the SnO2/PANI/Pd film has the maximum sensitivity ~ 400.8% out of all the fabricated films at 0.3% of the target gas. Our findings show that SnO2, SnO2/Pd, PANI, and SnO2/PANI/Pd composite sensing films have a bright future in the gas sensing application with incredibly-higher sensitivity towards CO gas.

3 citations

Journal ArticleDOI
Hussamud Din1, Faisal Iqbal1, Byeungleul Lee1Institutions (1)
Abstract: In this letter, a design technique is presented to reduce the cross-axis sensitivity (CAS) in single-drive multi-axis microelectromechanical systems (MEMS) gyroscope. A design technique based on resonant mode ordering concerning drive-displacement amplitudes ratio and frequency differences ratio was proposed. A simplified single-drive multi-axis MEMS gyroscope, based on the mode-split approach, was analyzed for cross-axis sensitivity. The designed gyroscope utilizing a driving scheme based on a simple folded coupling spring has equal x and y – axes drive-displacement amplitudes of 3.892 μ m respectively. The proposed resonant mode ordering technique was used, and an equal sense-frequency difference of 184 Hz was achieved with respect to drive-mode frequency. The designed gyroscope having common resonant mode order was analyzed, and CAS of x and y – axes was computed to be 0.241% and 0.387% respectively. The proposed resonant mode order technique successfully reduced the cross-axis sensitivity in the designed gyroscope. The reduced cross-axis sensitivities of x and y – axes were 0.025% and 0.076% respectively. Comparison of both designs showed a reduced rate of 89.627% and 80.362% in x and y – axes respectively. The main sensitivities of x and y – axes were computed to be 0.055 nm/dps respectively. Furthermore, the significance of the proposed technique was experimentally verified.

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