Cylindrical Sensor Research Articles

Adulteration detection in olive oil using dielectric technique and data mining

Olive oil is one of the most important agricultural crops due to its digestive properties and economic status. However, olive oil production is a costly process which causes an expensive price of the final product. The most jobbery ways during olive oil production consist of mixing other oils such as maize, sunflower and soya oil into the olive oil. So, the aim of this study was to develop a dielectric-based system to detect adulteration in olive oil using cylindrical capacitive sensor. For categorizing of fake olive oil by using frequency specification, Linear Discriminant Analysis (LDA) was developed. A set of 15 samples of olive oil, sunflower oil and canola oil which mixed with different ratio of adulteration, were used for calibration and evaluation of developed system. For each sample, 25 iterations were performed. Regarding results, the highest error rate was for a sample containing 60% olive oil-40% canola oil. In general, 7 iterations failed to be properly recognized. Regarding to accuracy indexes, specificity and sensitivity, the system had the minimum error for a mixed sample (60% olive oil-40% canola oil), specificity and sensitivity were obtained as 98% and 100%, respectively and accuracy was obtained as 72%, which was the weakest value. Finally, regarding mean value table for all sample, accuracy reached to 97%. Results showed the developed technique has a good capability of detecting impurities in olive oil. It is concluded from obtained results that the developed system revealed an acceptable adulterated detection in oil production.

수중 환경용 음향 배플의 내구성 연구

Cylindrical array sensor of a surface ship to detect an enemy is normally installed in the sonar dome. Reflected signals by some structures inside the sonar dome make unwanted signals. To minimize unwanted signals, acoustic baffles are used. Acoustic baffles are hard to install and replace, so the durability of acoustic baffles is an important design parameter. To verify the durability of acoustic baffle, accelerated aging tests according to temperature and pressure were performed. Acoustic baffle specimens were made and they are tested the visual and the performance (echo reduction and transmission loss) inspection before and after aging. After the inspection, the effect of accelerated aging of the acoustic baffles were discussed.

Planar Laser-Based QEPAS Trace Gas Sensor.

A novel quartz enhanced photoacoustic spectroscopy (QEPAS) trace gas detection scheme is reported in this paper. A cylindrical lens was employed for near-infrared laser focusing. The laser beam was shaped as a planar line laser between the gap of the quartz tuning fork (QTF) prongs. Compared with a spherical lens-based QEPAS sensor, the cylindrical lens-based QEPAS sensor has the advantages of easier laser beam alignment and a reduction of stringent stability requirements. Therefore, the reported approach is useful in long-term and continuous sensor operation.

Experimental study on a feasibility of using electromagnetic wave cylindrical cavity sensor to monitor the percentage of water fraction in a two phase system

This study proposed a microwave sensor system to monitor single and two phase flow systems. The microwave sensing technology in this study utilises the resonant frequencies that occur in a cylindrical cavity and monitor the changes in the permittivity of the measured phases to differentiate between the volume fractions of air, water and oil. The sensor system used two port configuration S21 (acted as transmitter and receiver) to detect the fluids inside the pipe. In principle, the strong polarity of water molecules results in higher permittivity in comparison to other materials. A tiny change of water fraction will cause a significant frequency shift. Electromagnetic waves in the range of 5–5.7GHz have been used to analyse a two phase air-water and oil-water stratified flow in a pipeline. The results demonstrated the potential of a microwave sensing technique to be used for the two phase systems monitoring. A significant shift in the frequency and change in the amplitude clearly shows the percentage fraction change of water in the pipe. The temperature study of water also demonstrated the independence of microwave analysis technique to the temperature change. This is accounted to overlapping modes negating the affect. Statistical analysis of the amplitude data for two phase systems shows a linear relationship of the change in water percentage to the amplitude. The electromagnetic wave cavity sensor successfully detected the change in the water fraction inside the pipe between 0 and 100%. The results show that the technique can be developed further to reduce the anomalies in the existing microwave sensor.

Multi-band polarization independent cylindrical metamaterial absorber and sensor application

A multi-band perfect metamaterial absorber (MA) based on a cylindrical waveguide with polarization independency is numerically presented and investigated in detail. The proposed absorber has a very simple configuration, and it operates at flexible frequency ranges within the microwave frequency regime by simply tuning the dimensions of the structure. The maximum absorption values are obtained as 99.9%, 97.5%, 85.8%, 68.2% and 40.2% at the frequencies of 1.34 GHz, 2.15 GHz, 3.2 GHz, 4.31 GHz and 5.41 GHz, respectively. The numerical studies verify that the proposed model can provide multi-band perfect absorptions at wide polarization and incident angles due to its rotational symmetry feature. We have also realized sensor and parametric study applications in order to show additional features of the suggested model. The suggested MA enables myriad potential applications in medical technologies, sensors and in defense industry etc.

Analysis of Machine Tool Spindles under Load

This paper deals with a new experimental approach to the analysis of radial, axial, and tilt error movements of machine tool spindles under load. The main focus is on the identification of error spindle movements under different machine operation conditions between 500 - 5000 rev / min and loads in the range of 50 - 500 N. Errors of the spindle movements are measured on the cylindrical workpiece using capacitance sensors for different loads. The analysis of measurements of radial, axial, and tilt error movements of machine tool spindle indicates a dependency of loads and measured errors. The integration of error measurements into novel multi-body dynamic models of machine tool spindles is very important for prediction of machine behaviour during a cutting process and for prediction of workpiece geometric accuracy.

A cylindrical cavity sensor for liquid water content measurement

In this paper, a novel sensor based on microwave resonant method is designed and applied to on-line water content measurement. A cylindrical cavity with both ends open is used as the resonant cavity of the sensor. The water content is obtained by measuring the resonance frequency of the cylindrical cavity. The use of cylindrical cavity offers the advantage of excellent resonant characteristics and, therefore, higher accuracy. Moreover, the cavity size of the sensor can be reduced by the modified measurement method in our paper, making the sensor more economy, and easy to be embedded in the pipes. Simulations and experiments had been conducted for the mixture of water and alcohol. The experimental results are consistent with the simulation results, which indicate the sensitivity of the sensor can reach less than 1%.

Physical limitations on spatial resolution in electrical capacitance tomography

Electrical capacitance tomography (ECT) is an imaging technique providing the distribution of permittivity in a medium by means of electrodes. As for any imaging systems, the accessible spatial resolution is a key parameter. In this paper the physical limitations on the spatial resolution of ECT sensors are analysed in terms of the accuracy of an object’s position and of the ability to distinguish between two close objects for any sensor geometry. Cylindrical geometry sensors are particularly studied and the example of a square geometry sensor is used to show how to apply the calculations to any other geometries. In cylindrical geometries, it is shown that a 50% gap between electrodes is a good compromise and that increasing the number of electrodes improves the spatial resolution near the electrodes but decreases the spatial resolution in the centre. The best spatial resolution at the centre of the sensor is obtained with 3 or 4 electrodes. In the square geometry studied, it is shown that a better distribution of the spatial resolution is obtained when there are electrodes in the corners.

End effects in rotational viscometry II. Pseudoplastic fluids at elevated Reynolds number

Neglecting of end effects in rotational viscometry introduces 10–30 % error in the estimate of shear stress σ R at surface of rotating cylindrical spindle. Actual values of the correction coefficient c L for a real sensor depend on pseudoplasticity level of a given sample (measured by the flow-behavior index n) and inertia level (measured by the Reynolds number Re). The correction coefficients for the real sensors with coaxial cylinders are calculated by solving the related flow problem for Generalized Newtonian Fluid with power-law viscosity function. In addition to the cylindrical sensors according to ISO 3219 CEN Bruxelles 53:019, (1994) , also some clones with different geometry simplex H = h/R are considered. The results on c L (n, Re, H) are presented as a simple empirical formula for easy use in downstream treatment of primary data using the pseudosimilarity approach.

The Langmuir Probe and Waves (LPW) Instrument for MAVEN

We describe the sensors, the sensor biasing and control, the signal-processing unit, and the operation of the Langmuir Probe and Waves (LPW) instrument on the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. The LPW instrument is designed to measure the electron density and temperature in the ionosphere of Mars and to measure spectral power density of waves (DC-2 MHz) in Mars’ ionosphere, including one component of the electric field. Low-frequency plasma waves can heat ions resulting in atmospheric loss. Higher-frequency waves are used to calibrate the density measurement and to study strong plasma processes. The LPW is part of the Particle and Fields (PF) suite on the MAVEN spacecraft. The LPW instrument utilizes two, 40 cm long by 0.635 cm diameter cylindrical sensors with preamplifiers, which can be configured to measure either plasma currents or plasma waves. The sensors are mounted on a pair of ${\sim}7$ meter long stacer booms. The sensors and nearby surfaces are controlled by a Boom Electronics Board (BEB). The Digital Fields Board (DFB) conditions the analog signals, converts the analog signals to digital, processes the digital signals including spectral analysis, and packetizes the data for transmission. The BEB and DFB are located inside of the Particle and Fields Digital Processing Unit (PFDPU).

원통형 배열센서 후면 구조물에 의해 발생하는 허위 표적 감소를 위한 음향 배플 연구

원통형 배열센서 후면 구조물에 의해 발생하는 허위 표적 감소를 위한 음향 배플 연구

Chain-based communication in cylindrical underwater wireless sensor networks.

Appropriate network design is very significant for Underwater Wireless Sensor Networks (UWSNs). Application-oriented UWSNs are planned to achieve certain objectives. Therefore, there is always a demand for efficient data routing schemes, which can fulfill certain requirements of application-oriented UWSNs. These networks can be of any shape, i.e., rectangular, cylindrical or square. In this paper, we propose chain-based routing schemes for application-oriented cylindrical networks and also formulate mathematical models to find a global optimum path for data transmission. In the first scheme, we devise four interconnected chains of sensor nodes to perform data communication. In the second scheme, we propose routing scheme in which two chains of sensor nodes are interconnected, whereas in third scheme single-chain based routing is done in cylindrical networks. After finding local optimum paths in separate chains, we find global optimum paths through their interconnection. Moreover, we develop a computational model for the analysis of end-to-end delay. We compare the performance of the above three proposed schemes with that of Power Efficient Gathering System in Sensor Information Systems (PEGASIS) and Congestion adjusted PEGASIS (C-PEGASIS). Simulation results show that our proposed 4-chain based scheme performs better than the other selected schemes in terms of network lifetime, end-to-end delay, path loss, transmission loss, and packet sending rate.

Structure design and performance analysis of a coaxial cylindrical capacitive sensor for liquid-level measurement

This paper presents the design and fabrication of a liquid-level measurement system based on a grounded cylindrical capacitive sensor for conductive liquids. Fabrication of the cylindrical capacitive sensor is performed with a novel approach of shielded cable. The inner conductor of shielded cable is connected to ground and the outer conductor is used to measure the liquid level. The relationship between the capacitance value of the cylindrical capacitive sensor and the liquid level is deduced by the analysis and calculation of physical parameters. Moreover, a backward difference calculation is adopted in order to offset the effects of the parasitic capacitance. The performance of the system has been experimentally tested in both grounded metallic and plastic containers. The experimental results show that the nonlinear error is smaller than 5mm over a range of 90cm. Over a wide measuring range of 200cm, the liquid-level measurement system has a nonlinear error smaller than 1.35cm.

The Axial Double Probe and Fields Signal Processing for the MMS Mission

The Axial Double Probe (ADP) instrument measures the DC to ∼100 kHz electric field along the spin axis of the Magnetospheric Multiscale (MMS) spacecraft (Burch et al., Space Sci. Rev., 2014, this issue), completing the vector electric field when combined with the spin plane double probes (SDP) (Torbert et al., Space Sci. Rev., 2014, this issue, Lindqvist et al., Space Sci. Rev., 2014, this issue). Two cylindrical sensors are separated by over 30 m tip-to-tip, the longest baseline on an axial DC electric field ever attempted in space. The ADP on each of the spacecraft consists of two identical, 12.67 m graphite coilable booms with second, smaller 2.25 m booms mounted on their ends. A significant effort was carried out to assure that the potential field of the MMS spacecraft acts equally on the two sensors and that photo- and secondary electron currents do not vary over the spacecraft spin. The ADP on MMS is expected to measure DC electric field with a precision of ∼1 mV/m, a resolution of ∼25 μV/m, and a range of ∼±1 V/m in most of the plasma environments MMS will encounter. The Digital Signal Processing (DSP) units on the MMS spacecraft are designed to perform analog conditioning, analog-to-digital (A/D) conversion, and digital processing on the ADP, SDP, and search coil magnetometer (SCM) (Le Contel et al., Space Sci. Rev., 2014, this issue) signals. The DSP units include digital filters, spectral processing, a high-speed burst memory, a solitary structure detector, and data compression. The DSP uses precision analog processing with, in most cases, >100 dB in dynamic range, better that −80 dB common mode rejection in electric field (E) signal processing, and better that −80 dB cross talk between the E and SCM (B) signals. The A/D conversion is at 16 bits with ∼1/4 LSB accuracy and ∼1 LSB noise. The digital signal processing is powerful and highly flexible allowing for maximum scientific return under a limited telemetry volume. The ADP and DSP are described in this article.

Design of an Online Grain Moisture Detection System

To test granular grain moisture, an online detection system is studied. This system uses a cylindrical capacitive sensor as the detection device. Through the signal detection and processing circuit, using SCM system to complete the online testing of grain moisture. As we all know, for the AC voltage signal, the influence of capacitors and inductors is coupled. So there are some errors no matter measures capacitance alone or measures inductance alone. But this design takes into account of both factors. The relationship between the ratio of the capacitance and conductance and the moisture content is studied. The results show that a small error and a high reliability are obtained.

A noncontact detection technique for interfacial bone defects and osseointegration assessment surrounding dental implants

Dental implantation is popular treatment for edentulous and partially dentate patients. Effectively assessing interfacial bone defects and osseointegration requires considerable effort for successful implantation. This study presents the development of a noncontact detection technique that uses a loudspeaker and a noncontact cylindrical capacitive-type displacement sensor to measure and evaluate the severity and location of imperfections surrounding the bone–implant interface through resonance frequency (RF) analysis. To justify the effectiveness, both in vitro and in vivo experiments were performed. The acoustic sweep signal of a loudspeaker was used to excite models, and the vibration response signal from a displacement sensor was detected and transferred to the spectrum. The first RF values of the spectra on each model were subsequently identified and used to assess the interfacial situation. The measuring results show that the RF differences can be identified and applied to evaluate bone defects, as well as osseointegration. The proposed technique is a promising approach to aid dentists in assessing dental implant stability after surgery.

A Long Cylindrical Optical Fiber Sensor Based on Multiple Total Internal Reflections in Heterodyne Interferometry

In this paper, a long cylindrical multimode optical fiber sensor (OFS) based on multiple total internal reflections in heterodyne interferometry is proposed. The cladding of the sensing portions of the fiber sensors is removed, but dont be coated with any metal films. With the OFS the phase shift difference due to the multiple total internal reflections (MTIRs) effect between the p-and s-polarizations can be measured by using the heterodyne interferometry. Substituting the phase shift difference into Fresnels equations, the refractive index for the tested medium can be calculated. According to numerical simulations and experimental results, the long cylindrical OFS is with the best resolution of 0.0000028 refractive index unit (RIU). However, the OFS could be valuable for chemical, biological and biochemical sensing. It has some merits, such as, high sensitivity, high resolution, stability, small size and in real-time measurement.

Acoustic Emission Measurement by Fiber Bragg Grating Glued to Cylindrical Sensor Holder

Fiber Bragg grating (FBG) is an optical fiber sensor and is suitable for acoustic emission (AE) measurements of structures such as chemical plants that require water resistance, explosion proofing, and so forth, However, directionality has been a problem in conventional usage which glues the grating range of an FBG to the inspection surface. This study proposes a cylinder-FBG (C-FBG) sensor with the FBG glued to a cylindrical sensor holder. Effectiveness of the sensor was evaluated by characterizing directionality and frequency sensitivity of the sensor and by comparing the detected AE signals in a 3-point bending test of a carbon fiber reinforced plastic (CFRP) laminate against a conventional wide-band piezoelectric AE sensor. The features of the detected signals were similar to the signals detected by the wide-band AE sensor. These results show that it is possible to produce a wide-band cylindrical sensor without the directionality limitations of the conventional usage of FBG.

20pm3-PM011 多方向圧力検出可能な円筒状の触覚センサ

A cylindrical tactile sensor was developed inspired by the anatomy of a tooth. The sensor was made using two rods; one was plugged into the other, just like a tooth that is plugged into alveolar bone. A piezoresistive conductive polymer composite was used to detect pressure application to the sensor. Pressure was applied to the tip and the sides of the sensor device while the resistances from the composite were measured. When pressure was applied to the tip of the device, the decrease in the relative resistance change can be observed from all six-pair electrode combinations. Applying pressure from the side in between two electrodes and the side that has an electrode caused the relative resistance change at the compressed side to be decreased, but increased at the tension side. The position of the applied pressure can be determined by observing the pattern of relative resistance change in between all pairs of electrode combinations.

The Design of Moisture Content of Lubricating Oil Detecting System Based on AD5933

In order to detect lubricating oil moisture content quickly, and replace lubricating oil of equipment in time , impedance type moisture content of lubricating oil detecting system based on AD5933 and cylindrical coaxial capacitive sensor are explored. The paper selected the excitation voltage amplitude and frequency reasonably, and studied the relationship between water content of lubricating oil and impedance value. The result suggests that when the excitation voltage amplitude is 2V, the frequency ranges from 4 kHz to 6 kHz, moisture content of lubricating oil is closely related to impedance value and lubricating oil resistance value decreases with the increase of its moisture content. In addition, the mathematical model between moisture content of lubricating oil and the impedance value is established, moisture content of lubricating oil can be calculated according to the impedance value.