scholarly journals Development of a Mobile Device for Odor Identification and Optimization of Its Measurement Protocol Based on the Free-Hand Measurement

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6190
Author(s):  
Gaku Imamura ◽  
Genki Yoshikawa
Keyword(s):  
Measurement Data ◽  
Low Frequency ◽  
Odor Identification ◽  
Practical Implementation ◽  
Detection Mechanism ◽  
Practical Applications ◽  
Machine Learning Classification ◽  
Measurement Protocol ◽  
Comprehensive Development ◽  
Machine Olfaction

Practical applications of machine olfaction have been eagerly awaited. A free-hand measurement, in which a measurement device is manually exposed to sample odors, is expected to be a key technology to realize practical machine olfaction. To implement odor identification systems based on the free-hand measurement, the comprehensive development of a measurement system including hardware, measurement protocols, and data analysis is necessary. In this study, we developed palm-size wireless odor measurement devices equipped with Membrane-type Surface stress Sensors (MSS) and investigated the effect of measurement protocols and feature selection on odor identification. By using the device, we measured vapors of liquids as odor samples through the free-hand measurement in different protocols. From the measurement data obtained with these protocols, datasets of transfer function ratios (TFRs) were created and analyzed by clustering and machine learning classification. It has been revealed that TFRs in the low-frequency range below 1 Hz notably contributed to vapor identification because the frequency components in that range reflect the dynamics of the detection mechanism of MSS. We also showed the optimal measurement protocol for accurate classification. This study has shown a guideline of the free-hand measurement and will contribute to the practical implementation of machine olfaction in society.

scholarly journals Modelling and Practical Implementation of 2-Coil Wireless Power Transfer Systems

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Hong Zhou ◽  
Bin Zhu ◽  
Wenshan Hu ◽  
Zhiwei Liu ◽  
Xingran Gao
Keyword(s):  
Low Frequency ◽  
Wireless Power Transfer ◽  
Practical Implementation ◽  
Prototype System ◽  
Power Transfer ◽  
Wireless Power ◽  
Practical Applications ◽  
Exciting Frequency ◽  
Low Costs ◽  
Frequency Power

Wireless power transfer (WPT) based on inductive coupling could be potentially applied in many practical applications. It has attracted a lot of research interests in the last few years. In this paper, the modelling, design, and implementation of a 2-coil WPT system are represented. The prototype system can be implemented using conventional power electronic devices such as MOSFETs with very low costs as it works in relative low frequency range (less than 1 MHz). In order to find out about the optimal working area for the WPT system, the circuit model based on the practical parameters from the prototype is built. The relationships between the exciting frequency, coupling, and output power are analyzed based on the circuit and magnetic principles. Apart from the theoretic study, the detailed implementation of the WPT prototype including the coil design, digital frequency generation, and high frequency power electronics is also introduced in this paper. Experiments are conducted to verify the effectiveness of the circuit analysis. By carefully tuning the circuit parameters, the prototype is able to deliver 20 W power through 2.2 meter distance with 20–30% efficiency.

scholarly journals Polytetrafluoroethylene Films in Rigid Polyurethane Foams’ Dielectric Permittivity Measurements with a One-Side Access Capacitive Sensor

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1173
Author(s):  
Ilze Beverte ◽  
Ugis Cabulis ◽  
Sergejs Gaidukovs
Keyword(s):  
Dielectric Properties ◽  
Dielectric Permittivity ◽  
Low Frequency ◽  
Capacitive Sensor ◽  
Polyurethane Foams ◽  
Active Area ◽  
Ptfe Film ◽  
Practical Applications ◽  
Permittivity Measurements ◽  
The Impact

As a non-metallic composite material, widely applied in industry, rigid polyurethane (PUR) foams require knowledge of their dielectric properties. In experimental determination of PUR foams’ dielectric properties protection of one-side capacitive sensor’s active area from adverse effects caused by the PUR foams’ test objects has to be ensured. In the given study, the impact of polytetrafluoroethylene (PTFE) films, thickness 0.20 mm and 0.04 mm, in covering or simulated coating the active area of one-side access capacitive sensor’ electrodes on the experimentally determined true dielectric permittivity spectra of rigid PUR foams is estimated. Penetration depth of the low frequency excitation field into PTFE and PUR foams is determined experimentally. Experiments are made in order to evaluate the difference between measurements on single PUR foams’ samples and on complex samples “PUR foams + PTFE film” with two calibration modes. A modification factor and a small modification criterion are defined and values of modifications are estimated in numerical calculations. Conclusions about possible practical applications of PTFE films in dielectric permittivity measurements of rigid PUR foams with one-side access capacitive sensor are made.

Ground Attenuation Factor Based on Measurements

2021 ◽  
Vol 263 (3) ◽  
pp. 3436-3447
Author(s):  
Dan Lin ◽  
Andrew Eng
Keyword(s):  
Near Field ◽  
Attenuation Factor ◽  
Measurement Data ◽  
Low Frequency ◽  
Sound Sources ◽  
Frequency Sound ◽  
Sound Levels ◽  
Different Types ◽  
Noise Measurements ◽  
Field Sound

Assumptions made on the ground types between sound sources and receivers can significantly impact the accuracy of environmental outdoor noise prediction. A guideline is provided in ISO 9613-2 and the value of ground factor ranges from 0 to 1, depending on the coverage of porous ground. For example, a ground absorption factor of 1 is suggested for grass ground covers. However, it is unclear if the suggested values are validated. The purpose of this study is to determine the sound absorption of different types of ground by measurements. Field noise measurements were made using an omnidirectional loudspeaker and two microphones on three different types of ground in a quiet neighborhood. One microphone was located 3ft from the loudspeaker to record near field sound levels in 1/3 and 1 octave bands every second. The other microphone was located a few hundred feet away to record far field sound in the same fashion as the near field microphone. The types of ground tested were concrete, grass, and grass with trees. Based on the measurement data, it was found that grass and trees absorb high frequency sound well and a ground factor of 1 may be used for 500Hz and up when using ISO 9613-2 methodology. However, at lower frequencies (125 Hz octave band and below), grassy ground reflects sound the same as concrete surfaces. Trees absorb more low frequency sound than grass, but less than ISO 9613-2 suggested.

scholarly journals An uncertainty-based protocol for the setup and measurement of soot/black carbon emissions from gas flares using sky-LOSA

2020 ◽  
Author(s):  
Bradley M. Conrad ◽  
Matthew R. Johnson
Keyword(s):  
Open Source ◽  
Black Carbon ◽  
Open Source Software ◽  
Carbon Emissions ◽  
Climate Models ◽  
Optical Measurement ◽  
Measurement Data ◽  
Software Tool ◽  
Measurement Protocol ◽  
Measurement Uncertainties

Abstract. Gas flaring is an important source of atmospheric soot/black carbon, especially in sensitive Arctic regions. However, emissions have traditionally been challenging to measure and remain poorly characterized, confounding international reporting requirements and adding uncertainty to climate models. The sky-LOSA optical measurement technique has emerged as a powerful means to quantify flare black carbon emissions in the field, but broader adoption has been hampered by the complexity of its deployment, where decisions during setup in the field can have profound, non-linear impacts on achievable measurement uncertainties. To address this challenge, this paper presents a prescriptive measurement protocol and associated open-source software tool that simplifies acquisition of sky-LOSA data in the field. Leveraging a comprehensive Monte Carlo-based General Uncertainty Analysis (GUA) to predict measurement uncertainties over the entire breadth of possible measurement conditions, general heuristics are identified to guide a sky-LOSA user toward optimal data collection. These are further extended in the open-source software utility, SetupSkyLOSA, which interprets the GUA results to provide detailed guidance for any specific combination of location, date/time, and flare, plume, and ambient conditions. Finally, a case study of a sky-LOSA measurement at an oil and gas facility in Mexico is used to demonstrate the utility of the software tool, where potentially small region(s) of optimal instrument setup are easily and quickly identified. It is hoped that this work will help increase the accessibility of the sky-LOSA technique and ultimately the availability of field measurement data for flare black carbon emissions.

Wireless Interface Technologies for 3D IC and Module Integration

2021 ◽  
Author(s):  
Tadahiro Kuroda ◽  
Wai-Yeung Yip
Keyword(s):  
Interface Design ◽  
Near Field ◽  
System Level ◽  
Practical Implementation ◽  
Comprehensive Treatment ◽  
3D Ic ◽  
Practical Applications ◽  
Reconfigurable Processors ◽  
Essential Resource ◽  
Wireless Interface

Synthesising fifteen years of research, this authoritative text provides a comprehensive treatment of two major technologies for wireless chip and module interface design, covering technology fundamentals, design considerations and tradeoffs, practical implementation considerations, and discussion of practical applications in neural network, reconfigurable processors, and stacked SRAM. It explains the design principles and applications of two near-field wireless interface technologies for 2.5-3D IC and module integration respectively, and describes system-level performance benefits, making this an essential resource for researchers, professional engineers and graduate students performing research in next-generation wireless chip and module interface design.

scholarly journals Eliminating Phase Drift for Distributed Optical Fiber Acoustic Sensing System with Empirical Mode Decomposition

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5392 ◽  
Author(s):  
Yuejuan Lv ◽  
Pengfei Wang ◽  
Yu Wang ◽  
Xin Liu ◽  
Qing Bai ◽  
...  
Keyword(s):  
Empirical Mode Decomposition ◽  
Low Frequency ◽  
Time Domain Reflectometry ◽  
Coherent Detection ◽  
Characteristic Time Scale ◽  
Phase Drift ◽  
Practical Applications ◽  
Mode Decomposition ◽  
Negative Effect ◽  
Signal Fluctuation

Phase-drift elimination is crucial to vibration recovery in the coherent detection phase-sensitive optical time domain reflectometry system. The phase drift drives the whole phase signal fluctuation as a baseline, and its negative effect is obvious when the detection time is long. In this paper, empirical mode decomposition (EMD) is presented to extract and eliminate the phase drift adaptively. It decomposes the signal by utilizing the characteristic time scale of the data, and the baseline is eventually obtained. It is validated by theory and experiment that the phase drift deteriorates seriously when the length of the vibration region increases. In an experiment, the phase drift was eliminated under the conditions of different vibration frequencies of 1 Hz, 5 Hz, and 10 Hz. The phase drift was also eliminated with different vibration intensities. Furthermore, the linear relationship between phase and vibration intensity is demonstrated with a correlation coefficient of 99.99%. The vibrations at 0.5 Hz and 0.3 Hz were detected with signal-to-noise ratios (SNRs) of 55.58 dB and 64.44 dB. With this method, when the vibration frequency is at the level of Hz or sub-Hz, the phase drift can be eliminated. This contributes to the detection and recovery of low-frequency perturbation events in practical applications.

Molecular coding of olfactory specificity

1975 ◽  
Vol 53 (9) ◽  
pp. 1247-1253 ◽  
Author(s):  
R. H. Wright ◽  
R. E. Burgess
Keyword(s):  
Organic Compounds ◽  
Molecular Basis ◽  
Insect Pests ◽  
Low Frequency ◽  
Olfactory Stimulation ◽  
Primary Process ◽  
Vibrational Modes ◽  
Physiological Mechanisms ◽  
Practical Applications

An analysis of the low-frequency vibrational modes of organic compounds in 19 odor categories indicates that the primary process of olfactory stimulation is common to both vertebrates and insects. Understanding the molecular basis of olfactory specificity may provide a clue to the physiological mechanisms and has immediate practical applications in the control of insect pests.

scholarly journals Rapid Laser Reactive Sintering Synthesis of Colossal Dielectric CCTO Ceramics

2020 ◽  
Vol 10 (10) ◽  
pp. 3510
Author(s):  
Jiayang He ◽  
Yanwei Huang ◽  
Guang Feng ◽  
Si Shen ◽  
Ming Yan ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Dielectric Permittivity ◽  
Laser Power ◽  
Low Frequency ◽  
Reactive Sintering ◽  
Practical Applications ◽  
Dense Microstructure ◽  
Calcium Copper Titanate ◽  
Average Grain Size ◽  
In Series

Calcium copper titanate (CCTO) ceramics were successfully synthesized using a rapid laser reactive sintering method without conventional long heat treatment times. The microstructure, dielectric properties, and impedance spectroscopy results for CCTO sintered at laser power rates of 25–85 W were investigated in detail. The X-ray diffractometry results showed that prepared CCTO is polycrystalline in a cubic structure with high purity. Scanning electron microscopy showed that CCTO sintered at 85 W has a dense microstructure with an average grain size of 30 nm. The dielectric permittivity of CCTO ceramics increased with increasing laser power over the entire frequency range and achieved a value of almost 105 in the low-frequency region. The dielectric permittivity maintained almost constant values from 102 Hz to 107 Hz, with lower dielectric loss (~0.1) from 103 Hz to 106 Hz, demonstrating good frequency stability. The impedance spectroscopy study showed that grain and grain boundary resistance decreased with rising laser power based on two parallel Resistor-Capacitance (RC) equivalent circuits in series. The activation energies for the grain boundaries were calculated from the impedance using the slope of ln σ versus 1/T and were found to be in the range of 0.53–0.63 eV. CCTO synthesized by rapid laser reactive sintering is competitive for practical applications.

On electrical optimisation using a Duffing-type vibrational energy harvester

2014 ◽  
Vol 229 (18) ◽  
pp. 3308-3319 ◽  
Author(s):  
Dongxu Su ◽  
Kimihiko Nakano ◽  
Rencheng Zheng ◽  
Matthew P Cartmell
Keyword(s):  
High Speed ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Electrical Power ◽  
Low Frequency ◽  
Load Resistance ◽  
Ball Screw ◽  
Response Analysis ◽  
Practical Implementation ◽  
Maximum Displacement

There has been much recent interest in the response analysis and optimisation of the linear energy harvester under ambient vibrations. To transfer maximum power to an electrical load in a resonant system, the load resistance should be equal to the sum of the electrical analogue of mechanical damping and internal resistance. However, principally because of the limited bandwidth offered by the linear energy harvester, the potential benefit of nonlinearity has recently been applied to improve the effectiveness of energy harvesting devices. For example, a Duffing-type oscillator can provide a wider bandwidth and greater effectiveness when subject to periodic excitations. The motivating hypothesis has been that the nonlinear Duffing energy harvester can also be optimised to maximise the available electrical power. This paper presents theoretical optimisation and numerical studies under three different conditions with the designed Duffing-type devices. First, the simplest model without any transmission mechanism and optimisation constraints is considered. Second, a device operated under low frequency and large force excitations using a ball screw to convert low-speed linear motion to high-speed rotation is analysed, where the optimum lead and load resistance are derived. Finally, considering the limitation of some dimensions in practical implementation, the constrained optimisation subjected to the maximum displacement of the seismic mass is also shown in this paper.

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