scholarly journals Development and Application of the Single-Spiral Inductive-Capacitive Resonant Circuit Sensor for Wireless, Real-Time Characterization of Moisture in Sand

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Andrew J. DeRouin ◽  
Zhanping You ◽  
Morgan Hansen ◽  
Aboelkasim Diab ◽  
Keat Ghee Ong
Keyword(s):  
Resonant Frequency ◽  
Parasitic Capacitance ◽  
Sensor Technology ◽  
Resonant Circuit ◽  
Spiral Inductor ◽  
Road Pavement ◽  
Specific Frequency ◽  
Inductive Elements ◽  
Lc Sensors

A wireless, passive embedded sensor was designed and fabricated for monitoring moisture in sand. The sensor, consisted of an inductive-capacitive (LC) resonant circuit, was made of a printed spiral inductor embedded inside sand. When exposed to an electromagnetic field, the sensor resonated at a specific frequency dependent on the inductance of the inductor and its parasitic capacitance. Since the permittivity of water was much higher than dry sand, moisture in sample increased the parasitic capacitance, thus decreasing the sensor’s resonant frequency. Therefore, the internal moisture level of the sample could be easily measured through tracking the resonant frequency using a detection coil. The fabrication process of this sensor is much simpler compared to LC sensors that contain both capacitive and inductive elements, giving it an economical advantage. A study was conducted to investigate the drying rate of sand samples of different grain sizes. The experimental data showed a strong correlation with the actual moisture content in the samples. The described sensor technology can be applied for long term monitoring of localized water content inside soils and sands to understand the environmental health in these media, or monitoring moisture levels within concrete supports and road pavement.

scholarly journals Wireless Passive Temperature Sensor Realized on Multilayer HTCC Tapes for Harsh Environment

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Qiulin Tan ◽  
Zhong Ren ◽  
Ting Cai ◽  
Chen Li ◽  
Tingli Zheng ◽  
...  
Keyword(s):  
High Temperature ◽  
Resonant Frequency ◽  
Temperature Sensor ◽  
Screen Printing ◽  
Resonant Circuit ◽  
Spiral Inductor ◽  
Harsh Environment ◽  
Average Sensitivity ◽  
Temperature Range ◽  
Good Repeatability

A wireless passive temperature sensor is designed on the basis of a resonant circuit, fabricated on multilayer high temperature cofired ceramic (HTCC) tapes, and measured with an antenna in the wireless coupling way. Alumina ceramic used as the substrate of the sensor is fabricated by lamination and sintering techniques, and the passive resonant circuit composed of a planar spiral inductor and a parallel plate capacitor is printed and formed on the substrate by screen-printing and postfiring processes. Since the permittivity of the ceramic becomes higher as temperature rises, the resonant frequency of the sensor decreases due to the increasing capacitance of the circuit. Measurements on the input impedance versus the resonant frequency of the sensor are achieved based on the principle, and discussions are made according to the exacted relative permittivity of the ceramic and quality factor (Q) of the sensor within the temperature range from 19°C (room temperature) to 900°C. The results show that the sensor demonstrates good high-temperature characteristics and wide temperature range. The average sensitivity of the sensor with good repeatability and reliability is up to 5.22 KHz/°C. It can be applied to detect high temperature in harsh environment.

Wireless Passive Sensor for Remote pH Monitoring

2011 ◽  
Vol 2 (1) ◽  
Author(s):  
Sharmistha Bhadra ◽  
Greg E. Bridges ◽  
Douglas J. Thomson ◽  
Michael S. Freund
Keyword(s):  
Resonant Frequency ◽  
Response Time ◽  
Dynamic Range ◽  
Ph Monitoring ◽  
Ph Sensor ◽  
Sensor Technology ◽  
Biomedical Sensing ◽  
Voltage Dependent ◽  
Solution Changes

In this paper we describe a wireless passive pH sensor for high-resolution remote pH monitoring. The sensor is based on a passive LC coil resonator whose resonant frequency is monitored remotely by measuring the change in impedance of an interrogator coil coupled to the sensor coil. The sensor resonator consists of an inductive coil connected in parallel with a voltage dependent capacitor and a pH combination electrode. Change in the electrode potential in response to variations of the pH of the solution changes the capacitance, and therefore the resonant frequency of the sensor. A linear response with a 0.1 pH resolution is achieved over a 4–10 pH dynamic range. The response time of the sensor is demonstrated to be less than 30 s and is limited by the response time of the pH combination electrode. The described sensor technology is suitable for long-term remote pH monitoring in numerous fields such as biomedical sensing, environmental monitoring, industrial and chemical processing, and structural health monitoring.

scholarly journals Designing Incentive Mechanisms for Mobile Crowdsensing with Intermediaries

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Yatong Chen ◽  
Huangxun Chen ◽  
Shuo Yang ◽  
Xiaofeng Gao ◽  
Yunhe Guo ◽  
...  
Keyword(s):  
Network Model ◽  
Large Scale ◽  
Incentive Compatibility ◽  
Rapid Development ◽  
Sensor Technology ◽  
Incentive Mechanisms ◽  
Mobile Crowdsensing ◽  
Network Applications ◽  
Sensing Platform

In the past decade, with the rapid development of wireless communication and sensor technology, ubiquitous smartphones equipped with increasingly rich sensors have more powerful computing and sensing abilities. Thus, mobile crowdsensing has received extensive attentions from both industry and academia. Recently, plenty of mobile crowdsensing applications come forth, such as indoor positioning, environment monitoring, and transportation. However, most existing mobile crowdsensing systems lack vast user bases and thus urgently need appropriate incentive mechanisms to attract mobile users to guarantee the service quality. In this paper, we propose to incorporate sensing platform and social network applications, which already have large user bases to build a three-layer network model. Thus, we can publicize the sensing platform promptly in large scale and provide long-term guarantee of data sources. Based on a three-layer network model, we design incentive mechanisms for both intermediaries and the crowdsensing platform and provide a solution to cope with the problem of user overlapping among intermediaries. We theoretically prove the properties of our proposed incentive mechanisms, including incentive compatibility, individual rationality, and efficiency. Furthermore, we evaluate our incentive mechanisms by extensive simulations. Evaluation results validate the effectiveness and efficiency of our proposed mechanisms.

scholarly journals Microbial biospherics: The experimental study of ecosystem function and evolution

2019 ◽  
Vol 116 (23) ◽  
pp. 11093-11098 ◽  
Author(s):  
Matthias C. Rillig ◽  
Janis Antonovics
Keyword(s):  
Ecosystem Function ◽  
Life Support ◽  
Natural World ◽  
Sensor Technology ◽  
Ecosystem Ecology ◽  
The Past ◽  
Closed Systems ◽  
Reductionist Approach ◽  
Long Term Studies

Awareness that our planet is a self-supporting biosphere with sunlight as its major source of energy for life has resulted in a long-term historical fascination with the workings of self-supporting ecological systems. However, the studies of such systems have never entered the canon of ecological or evolutionary tools and instead, have led a fringe existence connected to life support system engineering and space travel. We here introduce a framework for a renaissance in biospherics based on the study of matter-closed, energy-open ecosystems at a microbial level (microbial biospherics). Recent progress in genomics, robotics, and sensor technology makes the study of closed systems now much more tractable than in the past, and we argue that the time has come to emancipate the study of closed systems from this fringe context and bring them into a mainstream approach for studying ecosystem processes. By permitting highly replicated long-term studies, especially on predetermined and simplified systems, microbial biospheres offer the opportunity to test and develop strong hypotheses about ecosystem function and the ecological and evolutionary determinants of long-term system failure or persistence. Unlike many sciences, ecosystem ecology has never fully embraced a reductionist approach and has remained focused on the natural world in all its complexity. We argue that a reductionist approach to ecosystem ecology, using microbial biospheres, based on a combination of theory and the replicated study of much simpler self-enclosed microsystems could pay huge dividends.

The range of UV upturn strengths in early-type galaxies can be caused by dissolved metal-rich Globular Clusters

2019 ◽  
Vol 14 (S351) ◽  
pp. 112-116
Author(s):  
Paul Goudfrooij
Keyword(s):  
Globular Clusters ◽  
Dynamical Evolution ◽  
Virgo Cluster ◽  
Host Galaxy ◽  
Early Type ◽  
Luminosity Functions ◽  
Central Regions ◽  
Specific Frequency ◽  
Uv Upturn

AbstractI summarize the scenario by Goudfrooij (2018) in which the bulk of the ultraviolet (UV) upturn of giant early-type galaxies (ETGs) is due to helium-rich stellar populations that formed in massive metal-rich globular clusters (GCs) and subsequently dissolved in the strong tidal field in the central regions of the massive host galaxy. These massive GCs are assumed to show UV upturns similar to those observed recently in M87, the central galaxy in the Virgo cluster of galaxies. Data taken from the literature reveals a strong correlation between the strength of the UV upturn and the specific frequency of metal-rich GCs in ETGs. Adopting a Schechter function parametrization of GC mass functions, simulations of long-term dynamical evolution of GC systems show that this correlation can be explained by variations in the characteristic truncation mass Mc such that Mc increases with ETG luminosity in a way that is consistent with observed GC luminosity functions in ETGs. These findings suggest that the nature of the UV upturn in ETGs and the variation of its strength among ETGs are causally related to that of helium-rich populations in massive GCs, rather than intrinsic properties of field stars in ETGs.

scholarly journals Long-Term Home-Monitoring Sensor Technology in Patients with Parkinson’s Disease—Acceptance and Adherence

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5169 ◽  
Author(s):  
Angela Botros ◽  
Narayan Schütz ◽  
Martin Camenzind ◽  
Prabitha Urwyler ◽  
Daniel Bolliger ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Home Monitoring ◽  
The Body ◽  
Sensor Technology ◽  
Patient Acceptance ◽  
System Usability Scale ◽  
Technical Advances ◽  
World Environment

Parkinson’s disease (PD) is characterized by a highly individual disease-profile as well as fluctuating symptoms. Consequently, 24-h home monitoring in a real-world environment would be an ideal solution for precise symptom diagnostics. In recent years, small lightweight sensors which have assisted in objective, reliable analysis of motor symptoms have attracted a lot of attention. While technical advances are important, patient acceptance of such new systems is just as crucial to increase long-term adherence. So far, there has been a lack of long-term evaluations of PD-patient sensor adherence and acceptance. In a pilot study of PD patients (N = 4), adherence (wearing time) and acceptance (questionnaires) of a multi-part sensor set was evaluated over a 4-week timespan. The evaluated sensor set consisted of 3 body-worn sensors and 7 at-home installed ambient sensors. After one month of continuous monitoring, the overall system usability scale (SUS)-questionnaire score was 71.5%, with an average acceptance score of 87% for the body-worn sensors and 100% for the ambient sensors. On average, sensors were worn 15 h and 4 min per day. All patients reported strong preferences of the sensor set over manual self-reporting methods. Our results coincide with measured high adherence and acceptance rate of similar short-term studies and extend them to long-term monitoring.

scholarly journals EVALUATION OF GRADATION VARIATION OF THE GRANITE AGGREGATES USED IN ASPHALT MIXTURES AT THEIR MANUFACTURING PLACE

2020 ◽  
Author(s):  
Mantas Makulavičius ◽  
Henrikas Sivilevičius
Keyword(s):  
Standard Deviation ◽  
Asphalt Mixture ◽  
Quality Parameters ◽  
Key Factors ◽  
Manufacturing Plants ◽  
Road Pavement ◽  
Research Findings ◽  
The Mean ◽  
Mixture Homogeneity

Asphalt mixture gradation homogeneity is one of the key factors for proper laying and compaction during road pavement and its long-term maintenance afterwards. To achieve the good quality asphalt mixture homogeneity of aggregates used in road pavement must be kept in mind. Regarding to this, gradation variation of five different granite aggregates fractions (0/2, 2/5, 5/8, 8/11 and 11/16) from one of the largest manufacturing plants in Lithuania were determined in this paper. Total of 244 samples were taken from conveyer belt at the manufacturing place and all the data was evaluated by statistical methods providing histograms with theoretical curves of normal distribution. After that, the results were compared to each other and the requirements issued by Lithuanian road administration authority. Regression analysis was used to determine the dependence of standard deviation of percent passing and the mean percent passing through the sieves. The obtained research findings revealed that the maximum value of standard deviation of this dependence was equal to mean of 50% percent passing. Further investigations should include other aggregates quality parameters variation and its homogeneity throughout different stages of technological and transportation processes.

scholarly journals PLL-based nanoresonator driving IC with automatic parasitic capacitance cancellation and automatic gain control

2021 ◽  
pp. 002029402110293
Author(s):  
Hyunwoo Heo ◽  
Hyungseup Kim ◽  
Donggeun You ◽  
Yongsu Kwon ◽  
Yil-suk Yang ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Resonant Frequency ◽  
Automatic Gain Control ◽  
Gain Control ◽  
Parasitic Capacitance ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Driving Frequency ◽  
Loop Filter ◽  
Motional Resistance

This paper presents a phase-locked loop (PLL) based resonator driving integrated circuit (IC) with automatic parasitic capacitance cancellation and automatic gain control. The PLL consisting of a phase frequency detector (PFD), a loop filter, and a voltage-controlled oscillator (VCO) makes the driving frequency to be locked at the resonant frequency. The resonator is modeled by Butterworth–Van Dyke equivalent circuit model with motional resistance of 72.8 kΩ, capacitance of 6.19 fF, inductance of 79.4 mH, and parasitic parallel capacitance of 2.59 pF. To mitigate the magnitude and phase distortion in the resonator frequency response, it is necessary to compensate for the parasitic capacitance. The proposed automatic parasitic capacitance cancellation loop is operated in the open-loop mode. In the automatic parasitic capacitance cancellation phase, the outputs of the transimpedance amplifier (TIA) at the lower and higher frequency than the resonant frequency (VH and VL), are compared, and the programmable compensation capacitor array matches the VH and VL using binary-searched algorithm to cancel the parallel parasitic capacitance. The automatic gain control (AGC) loop keeps the oscillation at the suitable amplitude, and the AGC output can be used as a measurement of the motional resistance. The AGC loop is also digitally controlled. The proposed resonator driving IC is designed in a 0.18-μm bipolar complementary metal oxide semiconductor double-diffused metal oxide semiconductor (BCDMOS) process with an active area of 3.2 mm2. The simulated phase noise is −61.1 dBc/Hz at 1 kHz and the quality factor ( Q-factor) is 59,590.

scholarly journals Review of Wearable Devices and Data Collection Considerations for Connected Health

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5589
Author(s):  
Vini Vijayan ◽  
James Connolly ◽  
Joan Condell ◽  
Nigel McKelvey ◽  
Philip Gardiner
Keyword(s):  
Functional Ability ◽  
Wearable Sensors ◽  
Disease Diagnosis ◽  
Self Report ◽  
Sensor Technology ◽  
Self Assessment ◽  
Patient Recall ◽  
Wide Range ◽  
Patient Health

Wearable sensor technology has gradually extended its usability into a wide range of well-known applications. Wearable sensors can typically assess and quantify the wearer’s physiology and are commonly employed for human activity detection and quantified self-assessment. Wearable sensors are increasingly utilised to monitor patient health, rapidly assist with disease diagnosis, and help predict and often improve patient outcomes. Clinicians use various self-report questionnaires and well-known tests to report patient symptoms and assess their functional ability. These assessments are time consuming and costly and depend on subjective patient recall. Moreover, measurements may not accurately demonstrate the patient’s functional ability whilst at home. Wearable sensors can be used to detect and quantify specific movements in different applications. The volume of data collected by wearable sensors during long-term assessment of ambulatory movement can become immense in tuple size. This paper discusses current techniques used to track and record various human body movements, as well as techniques used to measure activity and sleep from long-term data collected by wearable technology devices.

scholarly journals Objectification of Public Bus Stop’s Pavement Surface Morphology

2018 ◽  
Vol 14 (1) ◽  
pp. 44-53 ◽  
Author(s):  
Martin Decký ◽  
Matúš Kováč ◽  
Juraj Mužík ◽  
Lenka Mičechová ◽  
Lukáš Ďuriš
Keyword(s):  
Life Cycle ◽  
Surface Morphology ◽  
The Road ◽  
Bus Stop ◽  
Pavement Surface ◽  
Road Pavement ◽  
Bus Stops

AbstractThe article deals with the road pavement surface morphology objectification in term of the surface unevenness degradation during the life cycle of bus stop pavements. The article presents the results of long-term rut depth measurements performed during 25 years on selected bus stops which were intended to determine correlation dependences of pavement rut depth on a number of design axles. The article also presents different methods for rut depth measurements including the straightedge test, Profilograph GE, TRIMBLE CX, and dynamic Road Scanner.

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