Coherent pulse interrogation system for fiber Bragg grating sensing of strain and pressure in dynamic extremes of materials.

Science.gov (United States)

Rodriguez, George; Jaime, Marcelo; Balakirev, Fedor; Mielke, Chuck H; Azad, Abul; Marshall, Bruce; La Lone, Brandon M; Henson, Bryan; Smilowitz, Laura

2015-06-01

A 100 MHz fiber Bragg grating (FBG) interrogation system is described and applied to strain and pressure sensing. The approach relies on coherent pulse illumination of the FBG sensor with a broadband short pulse from a femtosecond modelocked erbium fiber laser. After interrogation of the FBG sensor, a long multi-kilometer run of single mode fiber is used for chromatic dispersion to temporally stretch the spectral components of the reflected pulse from the FBG sensor. Dynamic strain or pressure induced spectral shifts in the FBG sensor are detected as a pulsed time domain waveform shift after encoding by the chromatic dispersive line. Signals are recorded using a single 35 GHz photodetector and a 50 G Samples per second, 25 GHz bandwidth, digitizing oscilloscope. Application of this approach to high-speed strain sensing in magnetic materials in pulsed magnetic fields to ~150 T is demonstrated. The FBG wavelength shifts are used to study magnetic field driven magnetostriction effects in LaCoO3. A sub-microsecond temporal shift in the FBG sensor wavelength attached to the sample under first order phase change appears as a fractional length change (strain: ΔL/L-4) in the material. A second application used FBG sensing of pressure dynamics to nearly 2 GPa in the thermal ignition of the high explosive PBX-9501 is also demonstrated. Both applications demonstrate the use of this FBG interrogation system in dynamical extreme conditions that would otherwise not be possible using traditional FBG interrogation approaches that are deemed too slow to resolve such events.

BreathSens: A Continuous On-Bed Respiratory Monitoring System With Torso Localization Using an Unobtrusive Pressure Sensing Array.

Science.gov (United States)

Liu, Jason J; Huang, Ming-Chun; Xu, Wenyao; Zhang, Xiaoyi; Stevens, Luke; Alshurafa, Nabil; Sarrafzadeh, Majid

2015-09-01

The ability to continuously monitor respiration rates of patients in homecare or in clinics is an important goal. Past research showed that monitoring patient breathing can lower the associated mortality rates for long-term bedridden patients. Nowadays, in-bed sensors consisting of pressure sensitive arrays are unobtrusive and are suitable for deployment in a wide range of settings. Such systems aim to extract respiratory signals from time-series pressure sequences. However, variance of movements, such as unpredictable extremities activities, affect the quality of the extracted respiratory signals. BreathSens, a high-density pressure sensing system made of e-Textile, profiles the underbody pressure distribution and localizes torso area based on the high-resolution pressure images. With a robust bodyparts localization algorithm, respiratory signals extracted from the localized torso area are insensitive to arbitrary extremities movements. In a study of 12 subjects, BreathSens demonstrated its respiratory monitoring capability with variations of sleep postures, locations, and commonly tilted clinical bed conditions.

Randomized crossover trial of a pressure sensing visual feedback system to improve mask fitting in noninvasive ventilation.

Science.gov (United States)

Brill, Anne-Kathrin; Moghal, Mohammad; Morrell, Mary J; Simonds, Anita K

2017-10-01

A good mask fit, avoiding air leaks and pressure effects on the skin are key elements for a successful noninvasive ventilation (NIV). However, delivering practical training for NIV is challenging, and it takes time to build experience and competency. This study investigated whether a pressure sensing system with real-time visual feedback improved mask fitting. During an NIV training session, 30 healthcare professionals (14 trained in mask fitting and 16 untrained) performed two mask fittings on the same healthy volunteer in a randomized order: one using standard mask-fitting procedures and one with additional visual feedback on mask pressure on the nasal bridge. Participants were required to achieve a mask fit with low mask pressure and minimal air leak (mask fit and staff- confidence were measured. Compared with standard mask fitting, a lower pressure was exerted on the nasal bridge using the feedback system (71.1 ± 17.6 mm Hg vs 63.2 ± 14.6 mm Hg, P mask-fitting training, resulted in a lower pressure on the skin and better mask fit for the volunteer, with increased staff confidence. © 2017 Asian Pacific Society of Respirology.

Pressure pressure-balanced pH sensing system for high temperature and high pressure water

International Nuclear Information System (INIS)

Tachibana, Koji

1995-01-01

As for the pH measurement system for high temperature, high pressure water, there have been the circumstances that first the reference electrodes for monitoring corrosion potential were developed, and subsequently, it was developed for the purpose of maintaining the soundness of metallic materials in high temperature, high pressure water in nuclear power generation. In the process of developing the reference electrodes for high temperature water, it was clarified that the occurrence of stress corrosion cracking in BWRs is closely related to the corrosion potential determined by dissolved oxygen concentration. As the types of pH electrodes, there are metal-hydrogen electrodes, glass electrodes, ZrO 2 diaphragm electrodes and TiO 2 semiconductor electrodes. The principle of pH measurement using ZrO 2 diaphragms is explained. The pH measuring system is composed of YSZ element, pressure-balanced type external reference electrode, pressure balancer and compressed air vessel. The stability and pH response of YSZ elements are reported. (K.I.)

Multiparameter fiber optic sensing system for monitoring enhanced geothermal systems

Energy Technology Data Exchange (ETDEWEB)

Challener, William A

2014-12-04

The goal of this project was to design, fabricate and test an optical fiber cable which supports multiple sensing modalities for measurements in the harsh environment of enhanced geothermal systems. To accomplish this task, optical fiber was tested at both high temperatures and strains for mechanical integrity, and in the presence of hydrogen for resistance to darkening. Both single mode (SM) and multimode (MM) commercially available optical fiber were identified and selected for the cable based on the results of these tests. The cable was designed and fabricated using a tube-within-tube construction containing two MM fibers and one SM fiber, and without supporting gel that is not suitable for high temperature environments. Commercial fiber optic sensing instruments using Raman DTS (distributed temperature sensing), Brillouin DTSS (distributed temperature and strain sensing), and Raleigh COTDR (coherent optical time domain reflectometry) were selected for field testing. A microelectromechanical systems (MEMS) pressure sensor was designed, fabricated, packaged, and calibrated for high pressure measurements at high temperatures and spliced to the cable. A fiber Bragg grating (FBG) temperature sensor was also spliced to the cable. A geothermal well was selected and its temperature and pressure were logged. The cable was then deployed in the well in two separate field tests and measurements were made on these different sensing modalities. Raman DTS measurements were found to be accurate to ±5°C, even with some residual hydrogen darkening. Brillouin DTSS measurements were in good agreement with the Raman results. The Rayleigh COTDR instrument was able to detect some acoustic signatures, but was generally disappointing. The FBG sensor was used to determine the effects of hydrogen darkening, but drift over time made it unreliable as a temperature or pressure sensor. The MEMS sensor was found to be highly stable and accurate to better than its 0.1% calibration.

Acoustic Wave Propagation in Pressure Sense Lines

Science.gov (United States)

Vitarius, Patrick; Gregory, Don A.; Wiley, John; Korman, Valentin

2003-01-01

Sense lines are used in pressure measurements to passively transmit information from hostile environments to areas where transducers can be used. The transfer function of a sense line can be used to obtain information about the measured environment from the protected sensor. Several properties of this transfer function are examined, including frequency dependence, Helmholtz resonance, and time of flight delay.

Demonstration of a Packaged Capacitive Pressure Sensor System Suitable for Jet Turbofan Engine Health Monitoring

Science.gov (United States)

Scardelletti, Maximilian C.; Jordan, Jennifer L.; Meredith, Roger D.; Harsh, Kevin; Pilant, Evan; Usrey, Michael W.; Beheim, Glenn M.; Hunter, Gary W.; Zorman, Christian A.

2016-01-01

In this paper, the development and characterization of a packaged pressure sensor system suitable for jet engine health monitoring is demonstrated. The sensing system operates from 97 to 117 MHz over a pressure range from 0 to 350 psi and a temperature range from 25 to 500 deg. The sensing system consists of a Clapp-type oscillator that is fabricated on an alumina substrate and is comprised of a Cree SiC MESFET, MIM capacitors, a wire-wound inductor, chip resistors and a SiCN capacitive pressure sensor. The pressure sensor is located in the LC tank circuit of the oscillator so that a change in pressure causes a change in capacitance, thus changing the resonant frequency of the sensing system. The chip resistors, wire-wound inductors and MIM capacitors have all been characterized at temperature and operational frequency, and perform with less than 5% variance in electrical performance. The measured capacitive pressure sensing system agrees very well with simulated results. The packaged pressure sensing system is specifically designed to measure the pressure on a jet turbofan engine. The packaged system can be installed by way of borescope plug adaptor fitted to a borescope port exposed to the gas path of a turbofan engine.

Integration of a capacitive pressure sensing system into the outer catheter wall for coronary artery FFR measurements

Science.gov (United States)

Stam, Frank; Kuisma, Heikki; Gao, Feng; Saarilahti, Jaakko; Gomes Martins, David; Kärkkäinen, Anu; Marrinan, Brendan; Pintal, Sebastian

2017-05-01

The deadliest disease in the world is coronary artery disease (CAD), which is related to a narrowing (stenosis) of blood vessels due to fatty deposits, plaque, on the arterial walls. The level of stenosis in the coronary arteries can be assessed by Fractional Flow Reserve (FFR) measurements. This involves determining the ratio between the maximum achievable blood flow in a diseased coronary artery and the theoretical maximum flow in a normal coronary artery. The blood flow is represented by a pressure drop, thus a pressure wire or pressure sensor integrated in a catheter can be used to calculate the ratio between the coronary pressure distal to the stenosis and the normal coronary pressure. A 2 Fr (0.67mm) outer diameter catheter was used, which required a high level of microelectronics miniaturisation to fit a pressure sensing system into the outer wall. The catheter has an eccentric guidewire lumen with a diameter of 0.43mm, which implies that the thickest catheter wall section provides less than 210 microns height for flex assembly integration consisting of two dies, a capacitive MEMS pressure sensor and an ASIC. In order to achieve this a very thin circuit flex was used, and the two chips were thinned down to 75 microns and flip chip mounted face down on the flex. Many challenges were involved in obtaining a flex layout that could wrap into a small tube without getting the dies damaged, while still maintaining enough flexibility for the catheter to navigate the arterial system.

Force Sensing Resistor and Evaluation of Technology for Wearable Body Pressure Sensing

Directory of Open Access Journals (Sweden)

Davide Giovanelli

2016-01-01

Full Text Available Wearable technologies are gaining momentum and widespread diffusion. Thanks to devices such as activity trackers, in form of bracelets, watches, or anklets, the end-users are becoming more and more aware of their daily activity routine, posture, and training and can modify their motor-behavior. Activity trackers are prevalently based on inertial sensors such as accelerometers and gyroscopes. Loads we bear with us and the interface pressure they put on our body also affect posture. A contact interface pressure sensing wearable would be beneficial to complement inertial activity trackers. What is precluding force sensing resistors (FSR to be the next best seller wearable? In this paper, we provide elements to answer this question. We build an FSR based on resistive material (Velostat and printed conductive ink electrodes on polyethylene terephthalate (PET substrate; we test its response to pressure in the range 0–2.7 kPa. We present a state-of-the-art review, filtered by the need to identify technologies adequate for wearables. We conclude that the repeatability is the major issue yet unsolved.

Inline pressure sensing mechanisms enabling scalable range and sensitivity

NARCIS (Netherlands)

Alveringh, Dennis; Groenesteijn, Jarno; Wiegerink, Remco J.; Lötters, Joost Conrad

2015-01-01

We report on two novel capacitive pressure sensing mechanisms that allow measurements inline with other fluidic devices on one chip, without introducing a large internal volume to the fluid path. The first sensing mechanism is based on out-of-plane bending of a U-shaped channel and the same

Integrated pressure sensing using capacitive Coriolis mass flow sensors

NARCIS (Netherlands)

Alveringh, Dennis; Wiegerink, Remco J.; Lötters, Joost Conrad

2017-01-01

The cross-sectional shape of microchannels is, dependent on the fabrication method, never perfectly circular. Consequently, the channels deform with the pressure, which is a non-ideal effect in flow sensors, but may be used for pressure sensing. Multiple suspended channels with different lengths

Fabrication and performance of pressure-sensing device consisting of electret film and organic semiconductor

Science.gov (United States)

Kodzasa, Takehito; Nobeshima, Daiki; Kuribara, Kazunori; Uemura, Sei; Yoshida, Manabu

2017-04-01

We propose a new concept of a pressure-sensitive device that consists of an organic electret film and an organic semiconductor. This device exhibits high sensitivity and selectivity against various types of pressure. The sensing mechanism of this device originates from a modulation of the electric conductivity of the organic semiconductor film induced by the interaction between the semiconductor film and the charged electret film placed face to face. It is expected that a complicated sensor array will be fabricated by using a roll-to-roll manufacturing system, because this device can be prepared by an all-printing and simple lamination process without high-level positional adjustment for printing processes. This also shows that this device with a simple structure is suitable for application to a highly flexible device array sheet for an Internet of Things (IoT) or wearable sensing system.

Mobile Sensing Systems

Science.gov (United States)

Macias, Elsa; Suarez, Alvaro; Lloret, Jaime

2013-01-01

Rich-sensor smart phones have made possible the recent birth of the mobile sensing research area as part of ubiquitous sensing which integrates other areas such as wireless sensor networks and web sensing. There are several types of mobile sensing: individual, participatory, opportunistic, crowd, social, etc. The object of sensing can be people-centered or environment-centered. The sensing domain can be home, urban, vehicular… Currently there are barriers that limit the social acceptance of mobile sensing systems. Examples of social barriers are privacy concerns, restrictive laws in some countries and the absence of economic incentives that might encourage people to participate in a sensing campaign. Several technical barriers are phone energy savings and the variety of sensors and software for their management. Some existing surveys partially tackle the topic of mobile sensing systems. Published papers theoretically or partially solve the above barriers. We complete the above surveys with new works, review the barriers of mobile sensing systems and propose some ideas for efficiently implementing sensing, fusion, learning, security, privacy and energy saving for any type of mobile sensing system, and propose several realistic research challenges. The main objective is to reduce the learning curve in mobile sensing systems where the complexity is very high. PMID:24351637

Mobile sensing systems.

Science.gov (United States)

Macias, Elsa; Suarez, Alvaro; Lloret, Jaime

2013-12-16

Rich-sensor smart phones have made possible the recent birth of the mobile sensing research area as part of ubiquitous sensing which integrates other areas such as wireless sensor networks and web sensing. There are several types of mobile sensing: individual, participatory, opportunistic, crowd, social, etc. The object of sensing can be people-centered or environment-centered. The sensing domain can be home, urban, vehicular… Currently there are barriers that limit the social acceptance of mobile sensing systems. Examples of social barriers are privacy concerns, restrictive laws in some countries and the absence of economic incentives that might encourage people to participate in a sensing campaign. Several technical barriers are phone energy savings and the variety of sensors and software for their management. Some existing surveys partially tackle the topic of mobile sensing systems. Published papers theoretically or partially solve the above barriers. We complete the above surveys with new works, review the barriers of mobile sensing systems and propose some ideas for efficiently implementing sensing, fusion, learning, security, privacy and energy saving for any type of mobile sensing system, and propose several realistic research challenges. The main objective is to reduce the learning curve in mobile sensing systems where the complexity is very high.

Mobile Sensing Systems

Directory of Open Access Journals (Sweden)

Elsa Macias

2013-12-01

Full Text Available Rich-sensor smart phones have made possible the recent birth of the mobile sensing research area as part of ubiquitous sensing which integrates other areas such as wireless sensor networks and web sensing. There are several types of mobile sensing: individual, participatory, opportunistic, crowd, social, etc. The object of sensing can be people-centered or environment-centered. The sensing domain can be home, urban, vehicular… Currently there are barriers that limit the social acceptance of mobile sensing systems. Examples of social barriers are privacy concerns, restrictive laws in some countries and the absence of economic incentives that might encourage people to participate in a sensing campaign. Several technical barriers are phone energy savings and the variety of sensors and software for their management. Some existing surveys partially tackle the topic of mobile sensing systems. Published papers theoretically or partially solve the above barriers. We complete the above surveys with new works, review the barriers of mobile sensing systems and propose some ideas for efficiently implementing sensing, fusion, learning, security, privacy and energy saving for any type of mobile sensing system, and propose several realistic research challenges. The main objective is to reduce the learning curve in mobile sensing systems where the complexity is very high.

The effects of pressure sensor acoustics on airdata derived from a High-angle-of-attack Flush Airdata Sensing (HI-FADS) system

Science.gov (United States)

Whitmore, Stephen A.; Moes, Timothy R.

1991-01-01

The accuracy of a nonintrusive high angle-of-attack flush airdata sensing (HI-FADS) system was verified for quasi-steady flight conditions up to 55 deg angle of attack during the F-18 High Alpha Research Vehicle (HARV) Program. The system is a matrix of nine pressure ports arranged in annular rings on the aircraft nose. The complete airdata set is estimated using nonlinear regression. Satisfactory frequency response was verified to the system Nyquist frequency (12.5 Hz). The effects of acoustical distortions within the individual pressure sensors of the nonintrusive pressure matrix on overall system performance are addressed. To quantify these effects, a frequency-response model describing the dynamics of acoustical distortion is developed and simple design criteria are derived. The model adjusts measured HI-FADS pressure data for the acoustical distortion and quantifies the effects of internal sensor geometries on system performance. Analysis results indicate that sensor frequency response characteristics very greatly with altitude, thus it is difficult to select satisfactory sensor geometry for all altitudes. The solution used presample filtering to eliminate resonance effects, and short pneumatic tubing sections to reduce lag effects. Without presample signal conditioning the system designer must use the pneumatic transmission line to attenuate the resonances and accept the resulting altitude variability.

Implantable electrolyte conductance-based pressure sensing catheter, II. Device construction and testing.

Science.gov (United States)

Tan, Robert; Benharash, Peyman; Schulam, Peter; Schmidt, Jacob J

2013-12-01

Direct measurements of arterial blood pressure most commonly use bulky external instrumentation containing a pressure transducer connected to an ex vivo fluid-filled arterial line, which is subject to several sensing artifacts. In situ blood pressure sensors, typically solid state piezoresistive, capacitive, and interferometric sensors, are unaffected by these artifacts, but can be expensive to produce and miniaturize. We have developed an alternative approach to blood pressure measurement based on deformation of an elastic tube filled with electrolyte solution. Simple measurement of the electrical conductance of this solution as the tube dimensions change allows determination of the external pressure. The sensor is made from inexpensive materials and its miniaturization is straightforward. In vitro static testing of initial sensor prototypes mounted on a catheter tip showed a linear response with applied pressure and a resolution of 1 mmHg. In vivo sensing followed catheterization of the sensor into the femoral artery of a porcine model through a 7F catheter port. The sensor performed comparably to a commercial pressure transducer also connected to the catheter port. Due to its scalability and cost, this sensor has the potential for use in a range of pressure sensing applications, such as measurement of intracranial, spinal, or interstitial pressures.

Using Distributed Fiber-Optic Sensing Systems to Estimate Inflow and Reservoir Properties

NARCIS (Netherlands)

Farshbaf Zinati, F.

2014-01-01

Recent developments in the deployment of distributed fiber-optic sensing systems in horizontal wells carry the promise to lead to a new, cheap and reliable way of monitoring production and reservoir performance. Practical applicability of distributed pressure sensing for quantitative inflow

Sub-bandage sensing system for remote monitoring of chronic wounds in healthcare

Science.gov (United States)

Hariz, Alex; Mehmood, Nasir; Voelcker, Nico

2015-12-01

Chronic wounds, such as venous leg ulcers, can be monitored non-invasively by using modern sensing devices and wireless technologies. The development of such wireless diagnostic tools may improve chronic wound management by providing evidence on efficacy of treatments being provided. In this paper we present a low-power portable telemetric system for wound condition sensing and monitoring. The system aims at measuring and transmitting real-time information of wound-site temperature, sub-bandage pressure and moisture level from within the wound dressing. The system comprises commercially available non-invasive temperature, moisture, and pressure sensors, which are interfaced with a telemetry device on a flexible 0.15 mm thick printed circuit material, making up a lightweight biocompatible sensing device. The real-time data obtained is transmitted wirelessly to a portable receiver which displays the measured values. The performance of the whole telemetric sensing system is validated on a mannequin leg using commercial compression bandages and dressings. A number of trials on a healthy human volunteer are performed where treatment conditions were emulated using various compression bandage configurations. A reliable and repeatable performance of the system is achieved under compression bandage and with minimal discomfort to the volunteer. The system is capable of reporting instantaneous changes in bandage pressure, moisture level and local temperature at wound site with average measurement resolutions of 0.5 mmHg, 3.0 %RH, and 0.2 °C respectively. Effective range of data transmission is 4-5 m in an open environment.

A simple sensing mechanism for wireless, passive pressure sensors.

Science.gov (United States)

Drazan, John F; Wassick, Michael T; Dahle, Reena; Beardslee, Luke A; Cady, Nathaniel C; Ledet, Eric H

2016-08-01

We have developed a simple wireless pressure sensor that consists of only three electrically isolated components. Two conductive spirals are separated by a closed cell foam that deforms when exposed to changing pressures. This deformation changes the capacitance and thus the resonant frequency of the sensors. Prototype sensors were submerged and wirelessly interrogated while being exposed to physiologically relevant pressures from 10 to 130 mmHg. Sensors consistently exhibited a sensitivity of 4.35 kHz/mmHg which is sufficient for resolving physiologically relevant pressure changes in vivo. These simple sensors have the potential for in vivo pressure sensing.

Ring-shaped inductive sensor design and application to pressure sensing

Energy Technology Data Exchange (ETDEWEB)

Noh, Myoung Gyu; Baek, Seong Ki; Park, Young Woo [Dept. of Mechatronics Engineering, Chungnam National University, Daejeon (Korea, Republic of); Kim, Sun Young [Samsung Electro-Mechanics, Busan (Korea, Republic of)

2015-10-15

Inductive sensors are versatile and economical devices that are widely used to measure a wide variety of physical variables, such as displacement, force, and pressure. In this paper, we propose a simple inductive sensor consisting of a thin partial ring and a coil set. The self-inductance of the sensor was estimated using magnetic circuit analysis and validated through finite element analysis (FEA). The natural frequency of the ring was estimated using Castigliano's theorem and the method of equivalent mass. The estimation was validated through experiments and FEA. A prototype sensor with a signal processing circuit is built and applied to noninvasively sense the pressure inside a flexible tube. The obtained sensor outputs show quadratic behavior with respect to the pressure. When fitted to a quadratic equation, the least-square measurement error was less than 2%. The results confirm the feasibility of pressure sensing using the proposed inductive sensor.

Ring-shaped inductive sensor design and application to pressure sensing

International Nuclear Information System (INIS)

Noh, Myoung Gyu; Baek, Seong Ki; Park, Young Woo; Kim, Sun Young

2015-01-01

Inductive sensors are versatile and economical devices that are widely used to measure a wide variety of physical variables, such as displacement, force, and pressure. In this paper, we propose a simple inductive sensor consisting of a thin partial ring and a coil set. The self-inductance of the sensor was estimated using magnetic circuit analysis and validated through finite element analysis (FEA). The natural frequency of the ring was estimated using Castigliano's theorem and the method of equivalent mass. The estimation was validated through experiments and FEA. A prototype sensor with a signal processing circuit is built and applied to noninvasively sense the pressure inside a flexible tube. The obtained sensor outputs show quadratic behavior with respect to the pressure. When fitted to a quadratic equation, the least-square measurement error was less than 2%. The results confirm the feasibility of pressure sensing using the proposed inductive sensor

Spatially digitized tactile pressure sensors with tunable sensitivity and sensing range.

Science.gov (United States)

Choi, Eunsuk; Sul, Onejae; Hwang, Soonhyung; Cho, Joonhyung; Chun, Hyunsuk; Kim, Hongjun; Lee, Seung-Beck

2014-10-24

When developing an electronic skin with touch sensation, an array of tactile pressure sensors with various ranges of pressure detection need to be integrated. This requires low noise, highly reliable sensors with tunable sensing characteristics. We demonstrate the operation of tactile pressure sensors that utilize the spatial distribution of contact electrodes to detect various ranges of tactile pressures. The device consists of a suspended elastomer diaphragm, with a carbon nanotube thin-film on the bottom, which makes contact with the electrodes on the substrate with applied pressure. The electrodes separated by set distances become connected in sequence with tactile pressure, enabling consecutive electrodes to produce a signal. Thus, the pressure is detected not by how much of a signal is produced but by which of the electrodes is registering an output. By modulating the diaphragm diameter, and suspension height, it was possible to tune the pressure sensitivity and sensing range. Also, adding a fingerprint ridge structure enabled the sensor to detect the periodicity of sub-millimeter grating patterns on a silicon wafer.

Self-motion effects on hydrodynamic pressure sensing: part I. Forward–backward motion

International Nuclear Information System (INIS)

Akanyeti, Otar; Chambers, Lily D; Brown, Jennifer; Megill, William M; Ježov, Jaas; Kruusmaa, Maarja; Venturelli, Roberto; Fiorini, Paolo

2013-01-01

In underwater locomotion, extracting meaningful information from local flows is as desirable as it is challenging, due to complex fluid-structure interaction. Sensing and motion are tightly interconnected; hydrodynamic signals generated by the external stimuli are modified by the self-generated flow signals. Given that very little is known about self-generated signals, we used onboard pressure sensors to measure the pressure profiles over the head of a fusiform-shape craft while moving forward and backward harmonically. From these measurements we obtained a second-order polynomial model which incorporates the velocity and acceleration of the craft to estimate the surface pressure within the swimming range up to one body length/second (L s −1 ). The analysis of the model reveals valuable insights into the temporal and spatial changes of the pressure intensity as a function of craft's velocity. At low swimming velocities ( −1 ) the pressure signals are more sensitive to the acceleration of the craft than its velocity. However, the inertial effects gradually become less important as the velocity increases. The sensors on the front part of the craft are more sensitive to its movements than the sensors on the sides. With respect to the hydrostatic pressure measured in still water, the pressure detected by the foremost sensor reaches values up to 300 Pa at 1 L s −1 swimming velocity, whereas the pressure difference between the foremost sensor and the next one is less than 50 Pa. Our results suggest that distributed pressure sensing can be used in a bimodal sensing strategy. The first mode detects external hydrodynamic events taking place around the craft, which requires minimal sensitivity to the self-motion of the craft. This can be accomplished by moving slowly with a constant velocity and by analyzing the pressure gradient as opposed to absolute pressure recordings. The second mode monitors the self-motion of the craft. It is shown here that distributed

Development of a Piezoelectric Vacuum Sensing Component for a Wide Pressure Range

Directory of Open Access Journals (Sweden)

Bing-Yu Wang

2014-11-01

Full Text Available In this study, we develop a clamped–clamped beam-type piezoelectric vacuum pressure sensing element. The clamped–clamped piezoelectric beam is composed of a PZT layer and a copper substrate. A pair of electrodes is set near each end. An input voltage is applied to a pair of electrodes to vibrate the piezoelectric beam, and the output voltage is measured at the other pair. Because the viscous forces on the piezoelectric beam vary at different air pressures, the vibration of the beam depends on the vacuum pressure. The developed pressure sensor can sense a wide range of pressure, from 6.5 × 10−6 to 760 Torr. The experimental results showed that the output voltage is inversely proportional to the gas damping ratio, and thus, the vacuum pressure was estimated from the output voltage.

A novel, intelligent, pressure-sensing colostomy plug for reducing fecal leakage.

Science.gov (United States)

Chen, Fei; Li, Zhi-Chao; Li, Qiang; Liang, Fei-Xue; Guo, Xiong-Bo; Huang, Zong-Hai

2015-06-01

This study aims to describe and report the effectiveness of a novel, pressure-sensing colostomy plug for reducing fecal leakage. Nine miniature Tibetan pigs, aged 6-8 months, were given colostomies and divided into three groups (n = 3 each group). A novel pressure-sensing colostomy plug was placed in each pig and set to indicate when intestinal pressures of either 5, 10, or 15 mm Hg, respectively, were reached. When the pressure thresholds were reached, the animals' bowels were examined for the presence of stool and/or stomal leakage, and the data were recorded at weeks 1, 4, and 8 after surgery. The colostomy plug calibrated to 15 mm Hg pressure demonstrated the greatest accuracy in predicting the presence of stool in the bowels of study animals, averaging >90% sensitivity. In general, the sensitivity for predicting the presence of stool did not vary significantly over time, though there was a slight increase in accuracy in the 5 mm Hg group at later time-points. The sensitivity for predicting stool in the bowel did not change significantly over time in any of the three groups. Stomal leakage was found to be inversely proportional to the pressure-sensor setting, in that the 15 mm Hg group exhibited the greatest amount of leakage. This difference, however, was found to be significant only at week 1 postsurgery. The intelligent, pressure-sensing colostomy plug was able to accurately predict the presence of stool in the bowel and maintain continence, allowing negligible leakage. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

An ultralow power wireless intraocular pressure monitoring system

International Nuclear Information System (INIS)

Liu Demeng; Mei Niansong; Zhang Zhaofeng

2014-01-01

This paper describes an ultralow power wireless intraocular pressure (IOP) monitoring system that is dedicated to sensing and transferring intraocular pressure of glaucoma patients. Our system is comprised of a capacitive pressure sensor, an application-specific integrated circuit, which is designed on the SMIC 180 nm process, and a dipole antenna. The system is wirelessly powered and demonstrates a power consumption of 7.56 μW at 1.24 V during continuous monitoring, a significant reduction in active power dissipation compared to existing work. The input RF sensitivity is −13 dBm. A significant reduction in input RF sensitivity results from the reduction of mismatch time of the ASK modulation caused by FM0 encoding. The system exhibits an average error of ± 1.5 mmHg in measured pressure. Finally, a complete IOP system is demonstrated in the real biological environment, showing a successful reading of the pressure of an eye. (semiconductor integrated circuits)

Low-power wireless micromanometer system for acute and chronic bladder-pressure monitoring.

Science.gov (United States)

Majerus, Steve J A; Fletter, Paul C; Damaser, Margot S; Garverick, Steven L

2011-03-01

This letter describes the design, fabrication, and testing of a wireless bladder-pressure-sensing system for chronic, point-of-care applications, such as urodynamics or closed-loop neuromodulation. The system consists of a miniature implantable device and an external RF receiver and wireless battery charger. The implant is small enough to be cystoscopically implanted within the bladder wall, where it is securely held and shielded from the urine stream. The implant consists of a custom application-specific integrated circuit (ASIC), a pressure transducer, a rechargeable battery, and wireless telemetry and recharging antennas. The ASIC includes instrumentation, wireless transmission, and power-management circuitry, and on an average draws less than 9 μA from the 3.6-V battery. The battery charge can be wirelessly replenished with daily 6-h recharge periods that can occur during the periods of sleep. Acute in vivo evaluation of the pressure-sensing system in canine models has demonstrated that the system can accurately capture lumen pressure from a submucosal implant location.

Optimization of design parameters for bulk micromachined silicon membranes for piezoresistive pressure sensing application

International Nuclear Information System (INIS)

Belwanshi, Vinod; Topkar, Anita

2016-01-01

Finite element analysis study has been carried out to optimize the design parameters for bulk micro-machined silicon membranes for piezoresistive pressure sensing applications. The design is targeted for measurement of pressure up to 200 bar for nuclear reactor applications. The mechanical behavior of bulk micro-machined silicon membranes in terms of deflection and stress generation has been simulated. Based on the simulation results, optimization of the membrane design parameters in terms of length, width and thickness has been carried out. Subsequent to optimization of membrane geometrical parameters, the dimensions and location of the high stress concentration region for implantation of piezoresistors have been obtained for sensing of pressure using piezoresistive sensing technique.

Optimization of design parameters for bulk micromachined silicon membranes for piezoresistive pressure sensing application

Science.gov (United States)

Belwanshi, Vinod; Topkar, Anita

2016-05-01

Finite element analysis study has been carried out to optimize the design parameters for bulk micro-machined silicon membranes for piezoresistive pressure sensing applications. The design is targeted for measurement of pressure up to 200 bar for nuclear reactor applications. The mechanical behavior of bulk micro-machined silicon membranes in terms of deflection and stress generation has been simulated. Based on the simulation results, optimization of the membrane design parameters in terms of length, width and thickness has been carried out. Subsequent to optimization of membrane geometrical parameters, the dimensions and location of the high stress concentration region for implantation of piezoresistors have been obtained for sensing of pressure using piezoresistive sensing technique.

A cylinder pressure based engine management system

Energy Technology Data Exchange (ETDEWEB)

Truscott, A.; Noble, A. [Ricardo Consulting Engineers Ltd. (United Kingdom); Mueller, R.; Hart, M.; Kroetz, G.; Eickhoff, M. [DaimlerChrysler AG (Germany); Cavalloni, C.; Gnielka, M. [Kistler Instrumente AG (Switzerland)

2000-07-01

Worldwide demands on fuel economy and lower emissions from automotive vehicles have led to stringent requirements in the development of Engine Management Systems (EMS). Cylinder Pressure based Engine Management Systems (CPEMS) provide a way forward in EMS technology by combining intelligent control algorithms with innovative sensing techniques. The full utilisation of model-based control and diagnostics to provide improvements in cost, efficiency, emissions and comfort requires the close monitoring of engine conditions. This is made possible with the advent of new inexpensive sensor materials that can withstand the harsh environment of the combustion chamber. AENEAS is a collaborative project undertaken by Ricardo, DaimlerChrysler and Kistler, with financial support from the European Commission and the Swiss Government, aimed at demonstrating the major benefits of CPEMS technology. This paper describes the application of CPEMS technology to a spark ignition (SI) engine. It describes how the combination of model based algorithms, incorporating physical principles, and cylinder pressure sensing can provide an effective means of engine control and diagnostics. Results are presented to demonstrate the benefits of this new technology. (author)

Double-Twisted Conductive Smart Threads Comprising a Homogeneously and a Gradient-Coated Thread for Multidimensional Flexible Pressure-Sensing Devices

KAUST Repository

Tai, Yanlong

2016-03-17

Fiber-based, flexible pressure-sensing systems have attracted attention recently due to their promising application as electronic skins. Here, a new kind of flexible pressure-sensing device based on a polydimethylsiloxane membrane instrumented with double-twisted smart threads (DTSTs) is reported. DTSTs are made of two conductive threads obtained by coating cotton threads with carbon nanotubes. One thread is coated with a homogeneous thickness of single-walled carbon nanotubes (SWCNTs) to detect the intensity of an applied load and the other is coated with a graded thickness of SWCNTs to identify the position of the load along the thread. The mechanism and capacity of DTSTs to accurately sense an applied load are systematically analyzed. Results demonstrate that the fabricated 1D, 2D, and 3D sensing devices can be used to predict both the intensity and the position of an applied load. The sensors feature high sensitivity (between ≈0.1% and 1.56% kPa) and tunable resolution, good cycling resilience (>104 cycles), and a short response time (minimum 2.5 Hz). The presented strategy is a viable alternative for the design of simple, low-cost pressure sensors.

Dielectric elastomer strain and pressure sensing enable reactive soft fluidic muscles

Science.gov (United States)

Veale, Allan J.; Anderson, Iain A.; Xie, Sheng Q.

2016-04-01

Wearable assistive devices are the future of rehabilitation therapy and bionic limb technologies. Traditional electric, hydraulic, and pneumatic actuators can provide the precise and powerful around-the-clock assistance that therapists cannot deliver. However, they do so in the confines of highly controlled factory environments, resulting in actuators too rigid, heavy, and immobile for wearable applications. In contrast, biological skeletal muscles have been designed and proven in the uncertainty of the real world. Bioinspired artificial muscle actuators aim to mimic the soft, slim, and self-sensing abilities of natural muscle that make them tough and intelligent. Fluidic artificial muscles are a promising wearable assistive actuation candidate, sharing the high-force, inherent compliance of their natural counterparts. Until now, they have not been able to self-sense their length, pressure, and force in an entirely soft and flexible system. Their use of rigid components has previously been a requirement for the generation of large forces, but reduces their reliability and compromises their ability to be comfortably worn. We present the unobtrusive integration of dielectric elastomer (DE) strain and pressure sensors into a soft Peano fluidic muscle, a planar alternative to the relatively bulky McKibben muscle. Characterization of these DE sensors shows they can measure the full operating range of the Peano muscle: strains of around 18% and pressures up to 400 kPa with changes in capacitance of 2.4 and 10.5 pF respectively. This is a step towards proprioceptive artificial muscles, paving the way for wearable actuation that can truly feel its environment.

LIGO sensing system performance

CERN Document Server

Landry, M

2002-01-01

The optical sensing subsystem of a LIGO interferometer is described. The system includes two complex interferometric sensing schemes to control test masses in length and alignment. The length sensing system is currently employed on all LIGO interferometers to lock coupled cavities on resonance. Auto-alignment is to be accomplished by a wavefront-sensing scheme which automatically corrects for angular fluctuations of the test masses. Improvements in lock stability and duration are noted when the wavefront auto-alignment system is employed. Preliminary results from the commissioning of the 2 km detector in Washington are shown.

Design of pressure-sensing diaphragm for MEMS capacitance diaphragm gauge considering size effect

Science.gov (United States)

Li, Gang; Li, Detian; Cheng, Yongjun; Sun, Wenjun; Han, Xiaodong; Wang, Chengxiang

2018-03-01

MEMS capacitance diaphragm gauge with a full range of (1˜1000) Pa is considered for its wide application prospect. The design of pressure-sensing diaphragm is the key to achieve balanced performance for this kind of gauges. The optimization process of the pressure-sensing diaphragm with island design of a capacitance diaphragm gauge based on MEMS technique has been reported in this work. For micro-components in micro scale range, mechanical properties are very different from that in the macro scale range, so the size effect should not be ignored. The modified strain gradient elasticity theory considering size effect has been applied to determine the bending rigidity of the pressure-sensing diaphragm, which is then used in the numerical model to calculate the deflection-pressure relation of the diaphragm. According to the deflection curves, capacitance variation can be determined by integrating over the radius of the diaphragm. At last, the design of the diaphragm has been optimized based on three parameters: sensitivity, linearity and ground capacitance. With this design, a full range of (1˜1000) Pa can be achieved, meanwhile, balanced sensitivity, resolution and linearity can be kept.

Bioinspired Infrared Sensing Materials and Systems.

Science.gov (United States)

Shen, Qingchen; Luo, Zhen; Ma, Shuai; Tao, Peng; Song, Chengyi; Wu, Jianbo; Shang, Wen; Deng, Tao

2018-05-11

Bioinspired engineering offers a promising alternative approach in accelerating the development of many man-made systems. Next-generation infrared (IR) sensing systems can also benefit from such nature-inspired approach. The inherent compact and uncooled operation of biological IR sensing systems provides ample inspiration for the engineering of portable and high-performance artificial IR sensing systems. This review overviews the current understanding of the biological IR sensing systems, most of which are thermal-based IR sensors that rely on either bolometer-like or photomechanic sensing mechanism. The existing efforts inspired by the biological IR sensing systems and possible future bioinspired approaches in the development of new IR sensing systems are also discussed in the review. Besides these biological IR sensing systems, other biological systems that do not have IR sensing capabilities but can help advance the development of engineered IR sensing systems are also discussed, and the related engineering efforts are overviewed as well. Further efforts in understanding the biological IR sensing systems, the learning from the integration of multifunction in biological systems, and the reduction of barriers to maximize the multidiscipline collaborations are needed to move this research field forward. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Integrated electrofluidic circuits: pressure sensing with analog and digital operation functionalities for microfluidics.

Science.gov (United States)

Wu, Chueh-Yu; Lu, Jau-Ching; Liu, Man-Chi; Tung, Yi-Chung

2012-10-21

Microfluidic technology plays an essential role in various lab on a chip devices due to its desired advantages. An automated microfluidic system integrated with actuators and sensors can further achieve better controllability. A number of microfluidic actuation schemes have been well developed. In contrast, most of the existing sensing methods still heavily rely on optical observations and external transducers, which have drawbacks including: costly instrumentation, professional operation, tedious interfacing, and difficulties of scaling up and further signal processing. This paper reports the concept of electrofluidic circuits - electrical circuits which are constructed using ionic liquid (IL)-filled fluidic channels. The developed electrofluidic circuits can be fabricated using a well-developed multi-layer soft lithography (MSL) process with polydimethylsiloxane (PDMS) microfluidic channels. Electrofluidic circuits allow seamless integration of pressure sensors with analog and digital operation functions into microfluidic systems and provide electrical readouts for further signal processing. In the experiments, the analog operation device is constructed based on electrofluidic Wheatstone bridge circuits with electrical outputs of the addition and subtraction results of the applied pressures. The digital operation (AND, OR, and XOR) devices are constructed using the electrofluidic pressure controlled switches, and output electrical signals of digital operations of the applied pressures. The experimental results demonstrate the designed functions for analog and digital operations of applied pressures are successfully achieved using the developed electrofluidic circuits, making them promising to develop integrated microfluidic systems with capabilities of precise pressure monitoring and further feedback control for advanced lab on a chip applications.

Glucose Monitoring System Based on Osmotic Pressure Measurements

Directory of Open Access Journals (Sweden)

Alexandra LEAL

2011-02-01

Full Text Available This paper presents the design and development of a prototype sensor unit for implementation in a long-term glucose monitoring system suitable for estimating glucose levels in people suffering from diabetes mellitus. The system utilizes osmotic pressure as the sensing mechanism and consists of a sensor prototype that is integrated together with a pre-amplifier and data acquisition unit for both data recording and processing. The sensor prototype is based on an embedded silicon absolute pressure transducer and a semipermeable nanoporous membrane that is enclosed in the sensor housing. The glucose monitoring system facilitates the integration of a low power microcontroller that is combined with a wireless inductive powered communication link. Experimental verification have proven that the system is capable of tracking osmotic pressure changes using albumin as a model compound, and thereby show a proof of concept for novel long term tracking of blood glucose from remote sensor nodes.

Combustion pressure-based engine management system

Energy Technology Data Exchange (ETDEWEB)

Mueller, R.; Hart, M. [DaimlerChrysler, Stuttart (Germany); Truscott, A.; Noble, A. [Ricardo, Shoreham-by-Sea (United Kingdom); Kroetz, G.; Richter, C. [DaimlerChrysler, Munchen (Germany); Cavalloni, C. [Kistler Instruments AG, Winterthur (Switzerland)

2000-07-01

In order to fulfill future emissions and OBD regulations, whilst meeting increasing demands for driveability and refinement, new technologies for SI engines have to be found in terms of sensors and algorithms for engine control units. One promising way, explored in the AENEAS collaborative project between DaimlerChrysler, Kistler, Ricardo and the European Commission, is to optimize the behavior of the system by using in-cylinder measurements and analysing them with modern control algorithms. In this paper a new engine management system based on combustion pressure sensing is presented. The pressure sensor is designed to give a reliable and accurate signal of the full pressure trace during a working cycle. With the application of new technologies low cost manufacturing appears to be achievable, so that an application in mass production can be considered. Furthermore, model-based algorithms were developed to allow optimal control of the engine based on the in-cylinder measurements. The algorithms incorporate physical principles to improve efficiency, emissions and to reduce the parameterisation effort. In the paper, applications of the combustion pressure signal for air mass estimation, knock detection, ignition control cam phase detection and diagnosis are discussed. (author)

Packaged Capacitive Pressure Sensor System for Aircraft Engine Health Monitoring

Science.gov (United States)

Scardelletti, Maximilian C.; Zorman, Christian A.

2016-01-01

This paper describes the development of a packaged silicon carbide (SiC) based MEMS pressure sensor system designed specifically for a conventional turbofan engine. The electronic circuit is based on a Clapp-type oscillator that incorporates a 6H-SiC MESFET, a SiCN MEMS capacitive pressure sensor, titanate MIM capacitors, wirewound inductors, and thick film resistors. The pressure sensor serves as the capacitor in the LC tank circuit, thereby linking pressure to the resonant frequency of the oscillator. The oscillator and DC bias circuitry were fabricated on an alumina substrate and secured inside a metal housing. The packaged sensing system reliably operates at 0 to 350 psi and 25 to 540C. The system has a pressure sensitivity of 6.8 x 10E-2 MHzpsi. The packaged system shows negligible difference in frequency response between 25 and 400C. The fully packaged sensor passed standard benchtop acceptance tests and was evaluated on a flight-worthy engine.

Initial development and testing of a novel foam-based pressure sensor for wearable sensing

Directory of Open Access Journals (Sweden)

Smyth Barry

2005-03-01

Full Text Available Abstract Background This paper provides an overview of initial research conducted in the development of pressure-sensitive foam and its application in wearable sensing. The foam sensor is composed of polypyrrole-coated polyurethane foam, which exhibits a piezo-resistive reaction when exposed to electrical current. The use of this polymer-coated foam is attractive for wearable sensing due to the sensor's retention of desirable mechanical properties similar to those exhibited by textile structures. Methods The development of the foam sensor is described, as well as the development of a prototype sensing garment with sensors in several areas on the torso to measure breathing, shoulder movement, neck movement, and scapula pressure. Sensor properties were characterized, and data from pilot tests was examined visually. Results The foam exhibits a positive linear conductance response to increased pressure. Torso tests show that it responds in a predictable and measurable manner to breathing, shoulder movement, neck movement, and scapula pressure. Conclusion The polypyrrole foam shows considerable promise as a sensor for medical, wearable, and ubiquitous computing applications. Further investigation of the foam's consistency of response, durability over time, and specificity of response is necessary.

Hierarchical system for autonomous sensing-healing of delamination in large-scale composite structures

International Nuclear Information System (INIS)

Minakuchi, Shu; Sun, Denghao; Takeda, Nobuo

2014-01-01

This study combines our hierarchical fiber-optic-based delamination detection system with a microvascular self-healing material to develop the first autonomous sensing-healing system applicable to large-scale composite structures. In this combined system, embedded vascular modules are connected through check valves to a surface-mounted supply tube of a pressurized healing agent while fiber-optic-based sensors monitor the internal pressure of these vascular modules. When delamination occurs, the healing agent flows into the vascular modules breached by the delamination and infiltrates the damage for healing. At the same time, the pressure sensors identify the damaged modules by detecting internal pressure changes. This paper begins by describing the basic concept of the combined system and by discussing the advantages that arise from its hierarchical nature. The feasibility of the system is then confirmed through delamination infiltration tests. Finally, the hierarchical system is validated in a plate specimen by focusing on the detection and infiltration of the damage. Its self-diagnostic function is also demonstrated. (paper)

PASSIVE WIRELESS MULTI-SENSOR TEMPERATURE AND PRESSURE SENSING SYSTEM USING ACOUSTIC WAVE DEVICES, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This proposal describes the development of passive surface acoustic wave (SAW) sensors and multi-sensor systems for NASA application to remote wireless sensing of...

Real-Time Strap Pressure Sensor System for Powered Exoskeletons

Directory of Open Access Journals (Sweden)

Jesús Tamez-Duque

2015-02-01

Full Text Available Assistive and rehabilitative powered exoskeletons for spinal cord injury (SCI and stroke subjects have recently reached the clinic. Proper tension and joint alignment are critical to ensuring safety. Challenges still exist in adjustment and fitting, with most current systems depending on personnel experience for appropriate individual fastening. Paraplegia and tetraplegia patients using these devices have impaired sensation and cannot signal if straps are uncomfortable or painful. Excessive pressure and blood-flow restriction can lead to skin ulcers, necrotic tissue and infections. Tension must be just enough to prevent slipping and maintain posture. Research in pressure dynamics is extensive for wheelchairs and mattresses, but little research has been done on exoskeleton straps. We present a system to monitor pressure exerted by physical human-machine interfaces and provide data about levels of skin/body pressure in fastening straps. The system consists of sensing arrays, signal processing hardware with wireless transmission, and an interactive GUI. For validation, a lower-body powered exoskeleton carrying the full weight of users was used. Experimental trials were conducted with one SCI and one able-bodied subject. The system can help prevent skin injuries related to excessive pressure in mobility-impaired patients using powered exoskeletons, supporting functionality, independence and better overall quality of life.

Reports in the area sensor technology: Part 2: Dynamic deviations which may appear via the sensing lines in measurement of reactor pressure and level

International Nuclear Information System (INIS)

Bergdahl, Bengt-Goeran

2002-12-01

The sensors are part of the safety system in a nuclear power plant. They are the first link in a chain of components, which affect the safety system. It is therefore of great importance that the sensors fulfil tough requirements on reliability and response time. In practice, the dynamic qualities of the sensors in a BWR are seldom, or never, tested. The static qualities, on the other hand, are controlled every year when the transmitters are calibrated. This is done during the regular outage of the power plant. It is common that several sensors are connected to the same sensing line. This is true especially in old reactors, where only a few pressure taps are available in the reactor pressure vessel. This is a troublesome disadvantage in the design, since a failure in one sensing line will affect all components, which are connected to that sensing line ('Common Cause Failure'). This report focuses on deviations in the measurement system connected to the sensing lines. The deviations are illustrated by examples from Swedish and foreign BWRs. The sensing lines are mechanically passive components. They can reduce a system's response time even if there are now deviations in the static presentation. This report mentions cases in nuclear power plants, where the time constant of the sensing line has changed from 0.1 seconds, which is a normal response time, to 5 seconds. This has happened because of a gradual blockage of the sensing line. Today, signal analysis is the only way to examine the dynamic qualities of sensing lines. Filtrations can be unveiled by measuring and analysing the transmitter signal, regardless the location of the filtration: in the sensing line, in the transmitter or in other instrumentation components. A practical case is presented where pulsation dampers with so-called needles were used at Ringhals 1 in Sweden. Their influence on the response time for the measurement signal corresponds to a time constant = 0.55 s. By eliminating the needles the

Line pressure effects on differential pressure measurements

International Nuclear Information System (INIS)

Neff, G.G.; Evans, R.P.

1982-01-01

The performance of differential pressure transducers in experimental pressurized water reactor (PWR) systems was evaluated. Transient differential pressure measurements made using a simple calibration proportionality relating differential pressure to output voltage could have large measurement uncertainties. A more sophisticated calibration equation was derived to incorporate the effects of zero shifts and sensitivity shifts as pressure in the pressure sensing line changes with time. A comparison made between the original calibration proportionality equation and the derived compensation equation indicates that potential measurement uncertainties can be reduced

Study on cooperative active sensing system

International Nuclear Information System (INIS)

Tsukune, Hideo; Kita, Nobuyuki; Hirai, Shigeoki; Kuniyoshi, Yasuo; Hara, Isao; Matsui, Toshihiro

1999-01-01

In order to realize autonomous type nuclear plant, three-dimensional geometrical modelling method, and a basic technology on information collection and processing system preparation in some nuclear basic technology developments such as 'study on system evaluation of nuclear facility furnished with artificial intelligence for nuclear power' and 'study on adaptability evaluation of information collection and processing system into autonomous type plant' had already been developed. In this study, a study on sensing system required for constructing robot groups capable of conducting autonomously traveling inspection and maintenance in large scale, complicated and diverse plant has been processed by aiming at establishment of dispersed cooperative intelligent system technology. In 1997 fiscal year, integration of cooperative visual sensing technique was attempted. And, at the same time, upgrading of individual element technology and transportation method essential to the integrated system were investigated. As a result, an operative active sensing prototype system due to transportation robot groups furnished with real time processing capacity on diverse informations by integration of cooperative active sensing technique and real time active sensing technique developed independently plural transportation robot. (G.K.)

All-Optical Frequency Modulated High Pressure MEMS Sensor for Remote and Distributed Sensing

DEFF Research Database (Denmark)

Reck, Kasper; Thomsen, Erik Vilain; Hansen, Ole

2011-01-01

We present the design, fabrication and characterization of a new all-optical frequency modulated pressure sensor. Using the tangential strain in a circular membrane, a waveguide with an integrated nanoscale Bragg grating is strained longitudinally proportional to the applied pressure causing...... a shift in the Bragg wavelength. The simple and robust design combined with the small chip area of 1 × 1.8 mm2 makes the sensor ideally suited for remote and distributed sensing in harsh environments and where miniaturized sensors are required. The sensor is designed for high pressure applications up...

Compressive Sensing in Communication Systems

DEFF Research Database (Denmark)

Fyhn, Karsten

2013-01-01

. The need for cheaper, smarter and more energy efficient wireless devices is greater now than ever. This thesis addresses this problem and concerns the application of the recently developed sampling theory of compressive sensing in communication systems. Compressive sensing is the merging of signal...... acquisition and compression. It allows for sampling a signal with a rate below the bound dictated by the celebrated Shannon-Nyquist sampling theorem. In some communication systems this necessary minimum sample rate, dictated by the Shannon-Nyquist sampling theorem, is so high it is at the limit of what...... with using compressive sensing in communication systems. The main contribution of this thesis is two-fold: 1) a new compressive sensing hardware structure for spread spectrum signals, which is simpler than the current state-of-the-art, and 2) a range of algorithms for parameter estimation for the class...

Social Factors in Aesthetics: Social Conformity Pressure and a Sense of Being Watched Affect Aesthetic Judgments.

Science.gov (United States)

Hesslinger, Vera M; Carbon, Claus-Christian; Hecht, Heiko

2017-01-01

The present study is a first attempt to experimentally test the impact of two specific social factors, namely social conformity pressure and a sense of being watched, on participants' judgments of the artistic quality of aesthetic objects. We manipulated conformity pressure with a test form in which a photograph of each stimulus was presented together with unanimously low (downward pressure) or high quality ratings (upward pressure) of three would-be previous raters. Participants' sense of being watched was manipulated by testing each of them in two settings, one of which contained an eyespots stimulus. Both social factors significantly affected the participants' judgments-unexpectedly, however, with conformity pressure only working in the downward direction and eyespots leading to an overall downward shift in participants' judgments. Our findings indicate the relevance of including explicit and implicit social factors in aesthetics research, thus also reminding us of the limitations of overly reductionist approaches to investigating aesthetic perception and experience.

Closed-loop feedback control for microfluidic systems through automated capacitive fluid height sensing.

Science.gov (United States)

Soenksen, L R; Kassis, T; Noh, M; Griffith, L G; Trumper, D L

2018-03-13

Precise fluid height sensing in open-channel microfluidics has long been a desirable feature for a wide range of applications. However, performing accurate measurements of the fluid level in small-scale reservoirs (sensor contact needs to be avoided. In particular, gravity-driven systems used in several microfluidic applications to establish pressure gradients and impose flow remain open-loop and largely unmonitored due to these sensing limitations. Here we present an optimized self-shielded coplanar capacitive sensor design and automated control system to provide submillimeter fluid-height resolution (∼250 μm) and control of small-scale open reservoirs without the need for direct fluid contact. Results from testing and validation of our optimized sensor and system also suggest that accurate fluid height information can be used to robustly characterize, calibrate and dynamically control a range of microfluidic systems with complex pumping mechanisms, even in cell culture conditions. Capacitive sensing technology provides a scalable and cost-effective way to enable continuous monitoring and closed-loop feedback control of fluid volumes in small-scale gravity-dominated wells in a variety of microfluidic applications.

Studying Sensing-Based Systems

DEFF Research Database (Denmark)

Kjærgaard, Mikkel Baun

2013-01-01

Recent sensing-based systems involve a multitude of users, devices, and places. These types of systems challenge existing approaches for conducting valid system evaluations. Here, the author discusses such evaluation challenges and revisits existing system evaluation methodologies....

Modeling low pressure baroreceptors and their contribution to blood pressure control

OpenAIRE

Sánchez de Zambrano, Betsy Mirley; Rojas-Sulbarán, Rubén Darío

2016-01-01

The main mechanism for blood pressure (BP) control is coordinated by the central nervous system through the sympathetic and parasympathetic systems. In order to simulate this mechanism, different mathematical models are available, but they take into account only the high pressure receptors as sensing systems for BP. However, other receptors located in low pressure areas have not, as far as we know, been considered in the models described in the literature, despite their important role in the ...

Affordable dual-sensing proximity sensor for touchless interactive systems

KAUST Repository

Nassar, Joanna M.

2016-09-13

We report an ultra-low cost flexible proximity sensor using only off-the-shelf recyclable materials such as aluminum foil, napkin and double-sided tape. Unlike previous reports, our device structure exhibits two sensing capabilities in one platform, with outstanding long detection range of 20 cm and pressure sensitivity of 0.05 kPa. This is the first ever demonstration of a low-cost, accessible, and batch manufacturing process for pressure and proximity sensing on a singular platform. The mechanical flexibility of the sensor makes it possible to mount on various irregular platforms, which is vital in many areas, such as robotics, machine automation, vehicular technology and inspection tools.

Study on cooperative active sensing system

International Nuclear Information System (INIS)

Tsukune, Hideo; Kita, Nobuyuki; Kuniyoshi, Yasuo; Hara, Isao; Matsui, Toshihiro; Matsushita, Toshio; Nagata, Kazuyuki; Nagakubo, Akihiko

1998-01-01

This study aims to develop a dispersed cooperative intellectualized system technique and a sensing system required for construction of a robot group inspectable in patrol and maintainable in selfish in a plant with large scale and complex variety. In particular, in order to establish a system with flexibility response to environment and soundness durable to abnormal accident, a cooperative active sensing technique and real-time active vision sensing technique were started. On the base of last two years results, in 1996 fiscal year, important and expansion of each element technique was conducted to start a study on movement of focussing point which was an important function of the active vision sensing. (G.K.)

An Enhanced Sensing Application Based on a Flexible Projected Capacitive-Sensing Mattress

Directory of Open Access Journals (Sweden)

Wen-Ying Chang

2014-04-01

Full Text Available This paper presents a cost-effective sensor system for mattresses that can classify the sleeping posture of an individual and prevent pressure ulcers. This system applies projected capacitive sensing to the field of health care. The charge time (CT method was used to sensitively and accurately measure the capacitance of the projected electrodes. The required characteristics of the projected capacitor were identified to develop large-area applications for sensory mattresses. The area of the electrodes, the use of shielding, and the increased length of the transmission line were calibrated to more accurately measure the capacitance of the electrodes in large-size applications. To offer the users comfort in the prone position, a flexible substrate was selected and covered with 16 × 20 electrodes. Compared with the static charge sensitive bed (SCSB, our proposed system-flexible projected capacitive-sensing mattress (FPCSM comes with more electrodes to increase the resolution of posture identification. As for the body pressure system (BPS, the FPCSM has advantages such as lower cost, higher aging-resistance capability, and the ability to sense the capacitance of the covered regions without physical contact. The proposed guard ring design effectively absorbs the noise and interrupts leakage paths. The projected capacitive electrode is suitable for proximity-sensing applications and succeeds at quickly recognizing the sleeping pattern of the user.

Displacement sensing system and method

Science.gov (United States)

VunKannon, Jr., Robert S

2006-08-08

A displacement sensing system and method addresses demanding requirements for high precision sensing of displacement of a shaft, for use typically in a linear electro-dynamic machine, having low failure rates over multi-year unattended operation in hostile environments. Applications include outer space travel by spacecraft having high-temperature, sealed environments without opportunity for servicing over many years of operation. The displacement sensing system uses a three coil sensor configuration, including a reference and sense coils, to provide a pair of ratio-metric signals, which are inputted into a synchronous comparison circuit, which is synchronously processed for a resultant displacement determination. The pair of ratio-metric signals are similarly affected by environmental conditions so that the comparison circuit is able to subtract or nullify environmental conditions that would otherwise cause changes in accuracy to occur.

Continuous blood pressure recordings simultaneously with functional brain imaging: studies of the glymphatic system

Science.gov (United States)

Zienkiewicz, Aleksandra; Huotari, Niko; Raitamaa, Lauri; Raatikainen, Ville; Ferdinando, Hany; Vihriälä, Erkki; Korhonen, Vesa; Myllylä, Teemu; Kiviniemi, Vesa

2017-03-01

The lymph system is responsible for cleaning the tissues of metabolic waste products, soluble proteins and other harmful fluids etc. Lymph flow in the body is driven by body movements and muscle contractions. Moreover, it is indirectly dependent on the cardiovascular system, where the heart beat and blood pressure maintain force of pressure in lymphatic channels. Over the last few years, studies revealed that the brain contains the so-called glymphatic system, which is the counterpart of the systemic lymphatic system in the brain. Similarly, the flow in the glymphatic system is assumed to be mostly driven by physiological pulsations such as cardiovascular pulses. Thus, continuous measurement of blood pressure and heart function simultaneously with functional brain imaging is of great interest, particularly in studies of the glymphatic system. We present our MRI compatible optics based sensing system for continuous blood pressure measurement and show our current results on the effects of blood pressure variations on cerebral brain dynamics, with a focus on the glymphatic system. Blood pressure was measured simultaneously with near-infrared spectroscopy (NIRS) combined with an ultrafast functional brain imaging (fMRI) sequence magnetic resonance encephalography (MREG, 3D brain 10 Hz sampling rate).

Wireless Damage Location Sensing System

Science.gov (United States)

Woodard, Stanley E. (Inventor); Taylor, Bryant Douglas (Inventor)

2012-01-01

A wireless damage location sensing system uses a geometric-patterned wireless sensor that resonates in the presence of a time-varying magnetic field to generate a harmonic response that will experience a change when the sensor experiences a change in its geometric pattern. The sensing system also includes a magnetic field response recorder for wirelessly transmitting the time-varying magnetic field and for wirelessly detecting the harmonic response. The sensing system compares the actual harmonic response to a plurality of predetermined harmonic responses. Each predetermined harmonic response is associated with a severing of the sensor at a corresponding known location thereof so that a match between the actual harmonic response and one of the predetermined harmonic responses defines the known location of the severing that is associated therewith.

Fiber-Optic Etalon Pressure Sensor System with High Thermal and Mechanical Stabilities, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Atmospheric pressure sensing in particular is of critical importance to any attemp of Mars landing. Pressure sensing has traditionally always drawn high interest...

Portable remote sensing image processing system; Kahangata remote sensing gazo shori system

Energy Technology Data Exchange (ETDEWEB)

Fujikawa, S; Uchida, K; Tanaka, S; Jingo, H [Dowa Engineering Co. Ltd., Tokyo (Japan); Hato, M [Earth Remote Sensing Data Analysis Center, Tokyo (Japan)

1997-10-22

Recently, geological analysis using remote sensing data has been put into practice due to data with high spectral resolution and high spatial resolution. There has been a remarkable increase in both software and hardware of personal computer. Software is independent of hardware due to Windows. It has become easy to develop softwares. Under such situation, a portable remote sensing image processing system coping with Window 95 has been developed. Using this system, basic image processing can be conducted, and present location can be displayed on the image in real time by linking with GPS. Accordingly, it is not required to bring printed images for the field works of image processing. This system can be used instead of topographic maps for overseas surveys. Microsoft Visual C++ ver. 2.0 is used for the software. 1 fig.

Elastomeric Sensing of Pressure with Liquid Metal and Wireless Inductive Coupling

Science.gov (United States)

Dick, Jacob; Zou, Xiyue; Hogan, Ben; Tumalle, Jonathan; Etikyala, Sowmith; Fung, Diego; Charles, Watley; Gu, Tianye; Hull, Patrick V.; Mazzeo, Aaron D.

2017-01-01

This project describes resistance-based soft sensors filled with liquid metal, which permit measurements of large strains (0 percent to 110 percent), associated with small forces of less than 30 Newtons. This work also demonstrates a methodology for wireless transfer of these strain measurements without connected electrodes. These sensors allow intermittent detection of pressure on soft membranes with low force. Adapting these sensors for passive wireless pressure sensing will eliminate the need for embedded batteries, and will allow the sensors to transmit pressure data through non-conductive materials including glass and acrylic. The absence of batteries allows us to embed these sensors into materials for long-term use because the sensors only use passive analog circuit elements. We found the oxidation of the liquid metal (eutectic gallium indium) plays a role in the repeatability of the soft sensors. We investigated how the oxidation layer affected the behavior of the sensor by encapsulating materials (silicone, fluorosilicone, and PVC) with varied permeabilities to oxygen. We measured the effects of mechanical loading on the oxidation layer and the effects of wireless inductive coupling on the oxidation layer. We concluded our research by investigating the effects of embedding self-resonant circuits into polydimethylsiloxane (PDMS). Efforts to design engineered systems with soft materials are a growing field with progress in soft robotics, epidermal electronics, and wearable electronics. In the field of soft robotics, PDMS-based grippers are capable of picking up delicate objects because their form-fitting properties allow them to conform to the shape of objects more easily than conventional robotic grippers. Epidermal devices also use PDMS as a substrate to hold electronic components such as radios, sensors, and power supply circuits. Additionally, PDMS-based soft sensors can monitor human motion with liquid metal embedded within micro-channels. Passive

Space remote sensing systems an introduction

CERN Document Server

Chen, H S

1985-01-01

Space Remote Sensing Systems: An Introduction discusses the space remote sensing system, which is a modern high-technology field developed from earth sciences, engineering, and space systems technology for environmental protection, resource monitoring, climate prediction, weather forecasting, ocean measurement, and many other applications. This book consists of 10 chapters. Chapter 1 describes the science of the atmosphere and the earth's surface. Chapter 2 discusses spaceborne radiation collector systems, while Chapter 3 focuses on space detector and CCD systems. The passive space optical rad

Distributed acoustic sensing with Michelson interferometer demodulation

Science.gov (United States)

Liu, Xiaohui; Wang, Chen; Shang, Ying; Wang, Chang; Zhao, Wenan; Peng, Gangding; Wang, Hongzhong

2017-09-01

The distributed acoustic sensing (DAS) has been extensively studied and widely used. A distributed acoustic sensing system based on the unbalanced Michelson interferometer with phase generated carrier (PGC) demodulation was designed and tested. The system could directly obtain the phase, amplitude, frequency response, and location information of sound wave at the same time and measurement at all points along the sensing fiber simultaneously. Experiments showed that the system successfully measured the acoustic signals with a phase-pressure sensitivity about-148 dB (re rad/μPa) and frequency response ripple less than 1.5 dB. The further field experiment showed that the system could measure signals at all points along the sensing fiber simultaneously.

Intelligent hand-portable proliferation sensing system

International Nuclear Information System (INIS)

Dieckman, S.L.; Bostrom, G.A.; Waterfield, L.G.; Jendrzejczyk, J.A.; Ahuja, S.; Raptis, A.C.

1997-01-01

Argonne National Laboratory, with support from DOE's Office of Nonproliferation and National Security, is currently developing an intelligent hand-portable sensor system. This system is designed specifically to support the intelligence community with the task of in-field sensing of nuclear proliferation and related activities. Based upon pulsed laser photo-ionization time-of-flight mass spectrometry technology, this novel sensing system is capable of quickly providing a molecular or atomic analysis of specimens. The system is capable of analyzing virtually any gas phase molecule, or molecule that can be induced into the gas phase by (for example) sample heating. This system has the unique advantages of providing unprecedented portability, excellent sensitivity, tremendous fieldability, and a high performance/cost ratio. The system will be capable of operating in a highly automated manner for on-site inspections, and easily modified for other applications such as perimeter monitoring aboard a plane or drone. The paper describes the sensing system

Sensing performances of ZnO nanostructures grown under different oxygen pressures to hydrogen

International Nuclear Information System (INIS)

Chu, Jin; Peng, Xiaoyan; Wang, Zhenbo; Feng, Peter

2012-01-01

Graphical abstract: Display Omitted Highlights: ► Surface morphology depends on the oxygen pressure. ► Structural degradation was observed for the ZnO samples when oxygen pressure was overhigh. ► The sensitivity of the ZnO-based sensors increase with grown oxygen pressure. -- Abstract: For extensive use in an industrialized process of individual ZnO nanostructures applied in gas sensors, a simple, inexpensive, and safe synthesis process is required. Here, nanostructured ZnO films were grown by a pulsed laser deposition technique under different oxygen pressures. Scanning electron microscopy images show nanopores, nanotips, and nanoparticles are obtained and energy dispersive X-ray spectroscopy data indicate oxygen concentration of the synthesized samples increases monotonously with oxygen pressure. The sensor based on ZnO with high oxygen concentration has high sensitivity, rapid response (9 s) and recovery (80 s) behavior to 500 ppm hydrogen below 150 °C. Experimental data indicate that high oxygen concentration effectively improves the sensing properties of nanostructured ZnO.

Use of a pressure sensing sheath: comparison with standard means of blood pressure monitoring in catheterization procedures.

Science.gov (United States)

Purdy, Phillip D; South, Charles; Klucznik, Richard P; Liu, Kenneth C; Novakovic, Robin L; Puri, Ajit S; Pride, G Lee; Aagaard-Kienitz, Beverly; Ray, Abishek; Elliott, Alan C

2017-08-01

Monitoring of blood pressure (BP) during procedures is variable, depending on multiple factors. Common methods include sphygmomanometer (BP cuff), separate radial artery catheterization, and side port monitoring of an indwelling sheath. Each means of monitoring has disadvantages, including time consumption, added risk, and signal dampening due to multiple factors. We sought an alternative approach to monitoring during procedures in the catheterization laboratory. A new technology involving a 330 µm fiberoptic sensor embedded in the wall of a sheath structure was tested against both radial artery catheter and sphygmomanometer readings obtained simultaneous with readings recorded from the pressure sensing system (PSS). Correlations and Bland-Altman analysis were used to determine whether use of the PSS could substitute for these standard techniques. The results indicated highly significant correlations in systolic, diastolic, and mean arterial pressures (MAP) when compared against radial artery catheterization (p<0.0001), and MAP means differed by <4%. Bland-Altman analysis of the data suggested that the sheath measurements can replace a separate radial artery catheter. While less striking, significant correlations were seen when PSS readings were compared against BP cuff readings. The PSS has competitive functionality to that seen with a dedicated radial artery catheter for BP monitoring and is available immediately on sheath insertion without the added risk of radial catheterization. The sensor is structurally separated from the primary sheath lumen and readings are unaffected by device introduction through the primary lumen. Time delays and potential complications from radial artery catheterization are avoided. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Poster Abstract: Towards a Categorization Framework for Occupancy Sensing Systems

DEFF Research Database (Denmark)

Kjærgaard, Mikkel Baun; Lazarova-Molnar, Sanja; Jradi, Muhyiddine

2015-01-01

on occupancy sensing systems goes beyond basic methods, there is an increasing need for better comparison of proposed occupancy sensing systems. Developers of occupancy sensing systems are also lacking good frameworks for understanding different options when building occupancy sensing systems. This poster...

Battery-Free Smart Sock for Abnormal Relative Plantar Pressure Monitoring.

Science.gov (United States)

Lin, Xiaoyou; Seet, Boon-Chong

2017-04-01

This paper presents a new design of a wearable plantar pressure monitoring system in the form of a smart sock for sensing abnormal relative pressure changes. One advantage of this approach is that with a battery-free design, this system can be powered solely by radio frequency (RF) energy harvested from a radio frequency identification (RFID) reader unit hosted on a smartphone of the wearer. At the same time, this RFID reader can read foot pressure values from an embedded sensor-tag in the sock. A pressure sensing matrix made of conductive fabric and flexible piezo-resistive material is integrated into the sock during the knitting process. Sensed foot pressures are digitized and stored in the memory of a sensor-tag, thus allowing relative foot pressure values to be tracked. The control unit of the smart sock is assembled on a flexible printed circuit board (FPC) that can be strapped to the lower limb and detached easily when it is not in use. Experiments show that the system can operate reliably in both tasks of RF energy harvesting and pressure measurement.

A Three-Dimensional Porous Conducting Polymer Composite with Ultralow Density and Highly Sensitive Pressure Sensing Properties

International Nuclear Information System (INIS)

Su, J. D.; Sun, J.L.; Chen, J.H.; Jia, X.Sh.; Li, J.T.; Yan, X.; Long, Y.Z.; Lou, T.; Yan, X.; Long, Y.Z.

2016-01-01

An ultra light conducting poly aniline/Si C/polyacrylonitrile (PANI/Si C/PAN) composite was fabricated by in situ polymerization of aniline monomer on the surface of fibers in Si C/PAN aerogel. The Si C/PAN aerogel was obtained by electro spinning, freeze-drying, and heat treatment. The ingredient, morphology, structure, and electrical properties of the aerogel before and after in situ polymerization were investigated by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and voltage-current characteristic measurement. The thermostability of PANI/Si C/PAN composite was investigated by thermogravimetric analysis (TGA) and electrical resistance measured at different temperatures. The density of the PANI/SiC/PAN composite was approximately 0.211gcm - 3, the porosity was 76.44%, and the conductivity was 0.013Sm - 1. The pressure sensing properties were evaluated at room temperature. The electrical resistance of as-prepared sample decreased gradually with the increase of pressure. Furthermore, the pressure sensing process was reversible and the response time was short (about 1s). This composite may have application in pressure sensor field

A Three-Dimensional Porous Conducting Polymer Composite with Ultralow Density and Highly Sensitive Pressure Sensing Properties

Directory of Open Access Journals (Sweden)

Jin-Dong Su

2016-01-01

Full Text Available An ultralight conducting polyaniline/SiC/polyacrylonitrile (PANI/SiC/PAN composite was fabricated by in situ polymerization of aniline monomer on the surface of fibers in SiC/PAN aerogel. The SiC/PAN aerogel was obtained by electrospinning, freeze-drying, and heat treatment. The ingredient, morphology, structure, and electrical properties of the aerogel before and after in situ polymerization were investigated by X-ray powder diffraction (XRD, Fourier transform infrared spectroscopy (FT-IR, scanning electron microscope (SEM, and voltage-current characteristic measurement. The thermostability of PANI/SiC/PAN composite was investigated by thermogravimetric analysis (TGA and electrical resistance measured at different temperatures. The density of the PANI/SiC/PAN composite was approximately 0.211 g cm−3, the porosity was 76.44%, and the conductivity was 0.013 S m−1. The pressure sensing properties were evaluated at room temperature. The electrical resistance of as-prepared sample decreased gradually with the increase of pressure. Furthermore, the pressure sensing process was reversible and the response time was short (about 1 s. This composite may have application in pressure sensor field.

Recent Progress of Self-Powered Sensing Systems for Wearable Electronics.

Science.gov (United States)

Lou, Zheng; Li, La; Wang, Lili; Shen, Guozhen

2017-12-01

Wearable/flexible electronic sensing systems are considered to be one of the key technologies in the next generation of smart personal electronics. To realize personal portable devices with mobile electronics application, i.e., wearable electronic sensors that can work sustainably and continuously without an external power supply are highly desired. The recent progress and advantages of wearable self-powered electronic sensing systems for mobile or personal attachable health monitoring applications are presented. An overview of various types of wearable electronic sensors, including flexible tactile sensors, wearable image sensor array, biological and chemical sensor, temperature sensors, and multifunctional integrated sensing systems is provided. Self-powered sensing systems with integrated energy units are then discussed, separated as energy harvesting self-powered sensing systems, energy storage integrated sensing systems, and all-in-on integrated sensing systems. Finally, the future perspectives of self-powered sensing systems for wearable electronics are discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High Sensitivity, Wearable, Piezoresistive Pressure Sensors Based on Irregular Microhump Structures and Its Applications in Body Motion Sensing.

Science.gov (United States)

Wang, Zongrong; Wang, Shan; Zeng, Jifang; Ren, Xiaochen; Chee, Adrian J Y; Yiu, Billy Y S; Chung, Wai Choi; Yang, Yong; Yu, Alfred C H; Roberts, Robert C; Tsang, Anderson C O; Chow, Kwok Wing; Chan, Paddy K L

2016-07-01

A pressure sensor based on irregular microhump patterns has been proposed and developed. The devices show high sensitivity and broad operating pressure regime while comparing with regular micropattern devices. Finite element analysis (FEA) is utilized to confirm the sensing mechanism and predict the performance of the pressure sensor based on the microhump structures. Silicon carbide sandpaper is employed as the mold to develop polydimethylsiloxane (PDMS) microhump patterns with various sizes. The active layer of the piezoresistive pressure sensor is developed by spin coating PSS on top of the patterned PDMS. The devices show an averaged sensitivity as high as 851 kPa(-1) , broad operating pressure range (20 kPa), low operating power (100 nW), and fast response speed (6.7 kHz). Owing to their flexible properties, the devices are applied to human body motion sensing and radial artery pulse. These flexible high sensitivity devices show great potential in the next generation of smart sensors for robotics, real-time health monitoring, and biomedical applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Active Sensing System with In Situ Adjustable Sensor Morphology

Science.gov (United States)

Nurzaman, Surya G.; Culha, Utku; Brodbeck, Luzius; Wang, Liyu; Iida, Fumiya

2013-01-01

Background Despite the widespread use of sensors in engineering systems like robots and automation systems, the common paradigm is to have fixed sensor morphology tailored to fulfill a specific application. On the other hand, robotic systems are expected to operate in ever more uncertain environments. In order to cope with the challenge, it is worthy of note that biological systems show the importance of suitable sensor morphology and active sensing capability to handle different kinds of sensing tasks with particular requirements. Methodology This paper presents a robotics active sensing system which is able to adjust its sensor morphology in situ in order to sense different physical quantities with desirable sensing characteristics. The approach taken is to use thermoplastic adhesive material, i.e. Hot Melt Adhesive (HMA). It will be shown that the thermoplastic and thermoadhesive nature of HMA enables the system to repeatedly fabricate, attach and detach mechanical structures with a variety of shape and size to the robot end effector for sensing purposes. Via active sensing capability, the robotic system utilizes the structure to physically probe an unknown target object with suitable motion and transduce the arising physical stimuli into information usable by a camera as its only built-in sensor. Conclusions/Significance The efficacy of the proposed system is verified based on two results. Firstly, it is confirmed that suitable sensor morphology and active sensing capability enables the system to sense different physical quantities, i.e. softness and temperature, with desirable sensing characteristics. Secondly, given tasks of discriminating two visually indistinguishable objects with respect to softness and temperature, it is confirmed that the proposed robotic system is able to autonomously accomplish them. The way the results motivate new research directions which focus on in situ adjustment of sensor morphology will also be discussed. PMID:24416094

Active sensing system with in situ adjustable sensor morphology.

Science.gov (United States)

Nurzaman, Surya G; Culha, Utku; Brodbeck, Luzius; Wang, Liyu; Iida, Fumiya

2013-01-01

Despite the widespread use of sensors in engineering systems like robots and automation systems, the common paradigm is to have fixed sensor morphology tailored to fulfill a specific application. On the other hand, robotic systems are expected to operate in ever more uncertain environments. In order to cope with the challenge, it is worthy of note that biological systems show the importance of suitable sensor morphology and active sensing capability to handle different kinds of sensing tasks with particular requirements. This paper presents a robotics active sensing system which is able to adjust its sensor morphology in situ in order to sense different physical quantities with desirable sensing characteristics. The approach taken is to use thermoplastic adhesive material, i.e. Hot Melt Adhesive (HMA). It will be shown that the thermoplastic and thermoadhesive nature of HMA enables the system to repeatedly fabricate, attach and detach mechanical structures with a variety of shape and size to the robot end effector for sensing purposes. Via active sensing capability, the robotic system utilizes the structure to physically probe an unknown target object with suitable motion and transduce the arising physical stimuli into information usable by a camera as its only built-in sensor. The efficacy of the proposed system is verified based on two results. Firstly, it is confirmed that suitable sensor morphology and active sensing capability enables the system to sense different physical quantities, i.e. softness and temperature, with desirable sensing characteristics. Secondly, given tasks of discriminating two visually indistinguishable objects with respect to softness and temperature, it is confirmed that the proposed robotic system is able to autonomously accomplish them. The way the results motivate new research directions which focus on in situ adjustment of sensor morphology will also be discussed.

A piezoelectric micro control valve with integrated capacitive sensing for ambulant blood pressure waveform monitoring

Science.gov (United States)

Groen, Maarten S.; Wu, Kai; Brookhuis, Robert A.; van Houwelingen, Marc J.; Brouwer, Dannis M.; Lötters, Joost C.; Wiegerink, Remco J.

2014-12-01

We have designed and characterized a MEMS microvalve with built-in capacitive displacement sensing and fitted it with a miniature piezoelectric actuator to achieve active valve control. The integrated displacement sensor enables high bandwidth proportional control of the gas flow through the valve. This is an essential requirement for non-invasive blood pressure waveform monitoring based on following the arterial pressure with a counter pressure. Using the capacitive sensor, we demonstrate negligible hysteresis in the valve control characteristics. Fabrication of the valve requires only two mask steps for deep reactive ion etching (DRIE) and one release etch.

A piezoelectric micro control valve with integrated capacitive sensing for ambulant blood pressure waveform monitoring

International Nuclear Information System (INIS)

Groen, Maarten S; Wu, Kai; Brookhuis, Robert A; Lötters, Joost C; Wiegerink, Remco J; Van Houwelingen, Marc J; Brouwer, Dannis M

2014-01-01

We have designed and characterized a MEMS microvalve with built-in capacitive displacement sensing and fitted it with a miniature piezoelectric actuator to achieve active valve control. The integrated displacement sensor enables high bandwidth proportional control of the gas flow through the valve. This is an essential requirement for non-invasive blood pressure waveform monitoring based on following the arterial pressure with a counter pressure. Using the capacitive sensor, we demonstrate negligible hysteresis in the valve control characteristics. Fabrication of the valve requires only two mask steps for deep reactive ion etching (DRIE) and one release etch. (paper)

Experimenting with Electrical Load Sensing on a Backhoe Loader

DEFF Research Database (Denmark)

Andersen, Torben Ole; Hansen, Michael Rygaard; Pedersen, Henrik Clemmensen

2005-01-01

Where traditional load sensing is made using hydro-mechanical regulators and load pressure is fed back hydraulically, electrical load sensing employs the usage of electronic sensors and electrically actuated components. This brings forth new possibilities, but also imposes problems concerning...... dynamic performance and stability. In this paper the possibilities for implementing electrical load sensing (ELS) on a backhoe loader is investigated. Major components in the system are modelled and verified, and a linear model of the pump is presented, which is used for designing the pump controller....... By comparing results from linear analyses performed on both the conventional hydraulic load sensing system (HLS) and the modified electrical load sensing system, it is concluded that system performance closely matching the conventional system is obtainable....

Noninvasive blood pressure measurement scheme based on optical fiber sensor

Science.gov (United States)

Liu, Xianxuan; Yuan, Xueguang; Zhang, Yangan

2016-10-01

Optical fiber sensing has many advantages, such as volume small, light quality, low loss, strong in anti-jamming. Since the invention of the optical fiber sensing technology in 1977, optical fiber sensing technology has been applied in the military, national defense, aerospace, industrial, medical and other fields in recent years, and made a great contribution to parameter measurement in the environment under the limited condition .With the rapid development of computer, network system, the intelligent optical fiber sensing technology, the sensor technology, the combination of computer and communication technology , the detection, diagnosis and analysis can be automatically and efficiently completed. In this work, we proposed a noninvasive blood pressure detection and analysis scheme which uses optical fiber sensor. Optical fiber sensing system mainly includes the light source, optical fiber, optical detector, optical modulator, the signal processing module and so on. wavelength optical signals were led into the optical fiber sensor and the signals reflected by the human body surface were detected. By comparing actual testing data with the data got by traditional way to measure the blood pressure we can establish models for predicting the blood pressure and achieve noninvasive blood pressure measurement by using spectrum analysis technology. Blood pressure measurement method based on optical fiber sensing system is faster and more convenient than traditional way, and it can get accurate analysis results in a shorter period of time than before, so it can efficiently reduce the time cost and manpower cost.

Sensitivity enhancement using annealed polymer optical fibre based sensors for pressure sensing applications

DEFF Research Database (Denmark)

Pospori, A.; Marques, C. A. F.; Saez-Rodriguez, D.

2016-01-01

for that investigation was an unexpected behaviour observed in an array of sensors which were used for liquid level monitoring. One sensor exhibited much lower pressure sensitivity and that was the only one that was not annealed. To further investigate the phenomenon, additional sensors were photo...... sensitivity of the devices. This can provide better performing sensors for use in stress, force and pressure sensing applications.......Thermal annealing can be used to induce a permanent negative Bragg wavelength shift for polymer fibre grating sensors and it was originally used for multiplexing purposes. Recently, researchers showed that annealing can also provide additional benefits, such as strain and humidity sensitivity...

Development of airborne remote sensing data assimilation system

International Nuclear Information System (INIS)

Gudu, B R; Bi, H Y; Wang, H Y; Qin, S X; Ma, J W

2014-01-01

In this paper, an airborne remote sensing data assimilation system for China Airborne Remote Sensing System is introduced. This data assimilation system is composed of a land surface model, data assimilation algorithms, observation data and fundamental parameters forcing the land surface model. In this data assimilation system, Variable Infiltration Capacity hydrologic model is selected as the land surface model, which also serves as the main framework of the system. Three-dimensional variation algorithm, four-dimensional variation algorithms, ensemble Kalman filter and Particle filter algorithms are integrated in this system. Observation data includes ground observations and remotely sensed data. The fundamental forcing parameters include soil parameters, vegetation parameters and the meteorological data

Spatially monitoring oxygen level in 3D microfabricated cell culture systems using optical oxygen sensing beads.

Science.gov (United States)

Wang, Lin; Acosta, Miguel A; Leach, Jennie B; Carrier, Rebecca L

2013-04-21

Capability of measuring and monitoring local oxygen concentration at the single cell level (tens of microns scale) is often desirable but difficult to achieve in cell culture. In this study, biocompatible oxygen sensing beads were prepared and tested for their potential for real-time monitoring and mapping of local oxygen concentration in 3D micro-patterned cell culture systems. Each oxygen sensing bead is composed of a silica core loaded with both an oxygen sensitive Ru(Ph2phen3)Cl2 dye and oxygen insensitive Nile blue reference dye, and a poly-dimethylsiloxane (PDMS) shell rendering biocompatibility. Human intestinal epithelial Caco-2 cells were cultivated on a series of PDMS and type I collagen based substrates patterned with micro-well arrays for 3 or 7 days, and then brought into contact with oxygen sensing beads. Using an image analysis algorithm to convert florescence intensity of beads to partial oxygen pressure in the culture system, tens of microns-size oxygen sensing beads enabled the spatial measurement of local oxygen concentration in the microfabricated system. Results generally indicated lower oxygen level inside wells than on top of wells, and local oxygen level dependence on structural features of cell culture surfaces. Interestingly, chemical composition of cell culture substrates also appeared to affect oxygen level, with type-I collagen based cell culture systems having lower oxygen concentration compared to PDMS based cell culture systems. In general, results suggest that oxygen sensing beads can be utilized to achieve real-time and local monitoring of micro-environment oxygen level in 3D microfabricated cell culture systems.

3D printed System-on-Package (SoP) for environmental sensing and localization applications

KAUST Repository

Zhen, Su

2017-12-22

This paper presents for the first time an innovative 3D printed SoP sensor node with temperature, pressure and humidity sensing capabilities. It has an integrated wireless readout through a near isotropic (900MHz) GSM antenna-on-package. This sensor node is connected to the internet for remote monitoring and has the capability of localization. The paper presents the design of antenna-on-package as well as details of the communication and localization system. Fabrication challenges unique to 3D printing and integration of electronics on 3D printed circuit board are also discussed. Finally, the paper presents measurement results of antenna radiation pattern, return loss, localization accuracy and accuracy of sensing parameters.

Closed-loop feedback control for microfluidic systems through automated capacitive fluid height sensing

OpenAIRE

Trumper, David; Kassis, Timothy; Griffith, Linda; Noh, Minkyun; Soenksen, Luis

2018-01-01

Precise fluid height sensing in open-channel microfluidics has long been a desirable feature for a wide range of applications. However, performing accurate measurements of the fluid level in small-scale reservoirs (<1mL) has proven to be an elusive goal, especially if direct fluid-sensor contact needs to be avoided. In particular, gravity-driven systems used in several microfluidic applications to establish pressure gradients and impose flow remain open-loop and largely unmonitored due to ...

Material requirements for bio-inspired sensing systems

Science.gov (United States)

Biggins, Peter; Lloyd, Peter; Salmond, David; Kusterbeck, Anne

2008-10-01

The aim of developing bio-inspired sensing systems is to try and emulate the amazing sensitivity and specificity observed in the natural world. These capabilities have evolved, often for specific tasks, which provide the organism with an advantage in its fight to survive and prosper. Capabilities cover a wide range of sensing functions including vision, temperature, hearing, touch, taste and smell. For some functions, the capabilities of natural systems are still greater than that achieved by traditional engineering solutions; a good example being a dog's sense of smell. Furthermore, attempting to emulate aspects of biological optics, processing and guidance may lead to more simple and effective devices. A bio-inspired sensing system is much more than the sensory mechanism. A system will need to collect samples, especially if pathogens or chemicals are of interest. Other functions could include the provision of power, surfaces and receptors, structure, locomotion and control. In fact it is possible to conceive of a complete bio-inspired system concept which is likely to be radically different from more conventional approaches. This concept will be described and individual component technologies considered.

Ultrahigh Temperature Capacitive Pressure Sensor

Science.gov (United States)

Harsh, Kevin

2014-01-01

Robust, miniaturized sensing systems are needed to improve performance, increase efficiency, and track system health status and failure modes of advanced propulsion systems. Because microsensors must operate in extremely harsh environments, there are many technical challenges involved in developing reliable systems. In addition to high temperatures and pressures, sensing systems are exposed to oxidation, corrosion, thermal shock, fatigue, fouling, and abrasive wear. In these harsh conditions, sensors must be able to withstand high flow rates, vibration, jet fuel, and exhaust. In order for existing and future aeropropulsion turbine engines to improve safety and reduce cost and emissions while controlling engine instabilities, more accurate and complete sensor information is necessary. High-temperature (300 to 1,350 C) capacitive pressure sensors are of particular interest due to their high measurement bandwidth and inherent suitability for wireless readout schemes. The objective of this project is to develop a capacitive pressure sensor based on silicon carbon nitride (SiCN), a new class of high-temperature ceramic materials, which possesses excellent mechanical and electric properties at temperatures up to 1,600 C.

Gait Dynamics Sensing Using IMU Sensor Array System

Directory of Open Access Journals (Sweden)

Slavomir Kardos

2017-01-01

Full Text Available The article deals with a progressive approach in gait sensing. It is incorporated by IMU (Inertia Measurement Unit complex sensors whose field of acting is mainly the motion sensing in medicine, automotive and other industry, self-balancing systems, etc. They allow acquiring the position and orientation of an object in 3D space. Using several IMU units the sensing array for gait dynamics was made. Based on human gait analysis the 7-sensor array was designed to build a gait motion dynamics sensing system with the possibility of graphical interpretation of data from the sensing modules in real-time graphical application interface under the LabVIEW platform. The results of analyses can serve as the information for medical diagnostic purposes. The main control part of the system is microcontroller, whose function is to control the data collection and flow, provide the communication and power management.

Stretchable Dual-Capacitor Multi-Sensor for Touch-Curvature-Pressure-Strain Sensing.

Science.gov (United States)

Jin, Hanbyul; Jung, Sungchul; Kim, Junhyung; Heo, Sanghyun; Lim, Jaeik; Park, Wonsang; Chu, Hye Yong; Bien, Franklin; Park, Kibog

2017-09-07

We introduce a new type of multi-functional capacitive sensor that can sense several different external stimuli. It is fabricated only with polydimethylsiloxane (PDMS) films and silver nanowire electrodes by using selective oxygen plasma treatment method without photolithography and etching processes. Differently from the conventional single-capacitor multi-functional sensors, our new multi-functional sensor is composed of two vertically-stacked capacitors (dual-capacitor). The unique dual-capacitor structure can detect the type and strength of external stimuli including curvature, pressure, strain, and touch with clear distinction, and it can also detect the surface-normal directionality of curvature, pressure, and touch. Meanwhile, the conventional single-capacitor sensor has ambiguity in distinguishing curvature and pressure and it can detect only the strength of external stimulus. The type, directionality, and strength of external stimulus can be determined based on the relative capacitance changes of the two stacked capacitors. Additionally, the logical flow reflected on a tree structure with its branches reaching the direction and strength of the corresponding external stimulus unambiguously is devised. This logical flow can be readily implemented in the sensor driving circuit if the dual-capacitor sensor is commercialized actually in the future.

Fourier analysis for hydrostatic pressure sensing in a polarization-maintaining photonic crystal fiber

International Nuclear Information System (INIS)

Childs, Paul; Wong, Allan C. L.; Fu, H. Y.; Liao, Yanbiao; Tam, Hwayaw; Lu Chao; Wai, P. K. A.

2010-01-01

.We measured the hydrostatic pressure dependence of the birefringence and birefringent dispersion of a Sagnac interferometric sensor incorporating a length of highly birefringent photonic crystal fiber using Fourier analysis. Sensitivity of both the phase and chirp spectra to hydrostatic pressure is demonstrated. Using this analysis, phase-based measurements showed a good linearity with an effective sensitivity of 9.45nm/MPa and an accuracy of ±7.8kPa using wavelength-encoded data and an effective sensitivity of -55.7cm -1 /MPa and an accuracy of ±4.4kPa using wavenumber-encoded data. Chirp-based measurements, though nonlinear in response, showed an improvement in accuracy at certain pressure ranges with an accuracy of ±5.5kPa for the full range of measured pressures using wavelength-encoded data and dropping to within ±2.5kPa in the range of 0.17 to 0.4MPa using wavenumber-encoded data. Improvements of the accuracy demonstrated the usefulness of implementing chirp-based analysis for sensing purposes.

Hydrodynamic pressure sensing with an artificial lateral line in steady and unsteady flows

International Nuclear Information System (INIS)

Venturelli, Roberto; Akanyeti, Otar; Visentin, Francesco; Fiorini, Paolo; Ježov, Jaas; Toming, Gert; Kruusmaa, Maarja; Chambers, Lily D; Brown, Jennifer; Megill, William M

2012-01-01

With the overall goal being a better understanding of the sensing environment from the local perspective of a situated agent, we studied uniform flows and Kármán vortex streets in a frame of reference relevant to a fish or swimming robot. We visualized each flow regime with digital particle image velocimetry and then took local measurements using a rigid body with laterally distributed parallel pressure sensor arrays. Time and frequency domain methods were used to characterize hydrodynamically relevant scenarios in steady and unsteady flows for control applications. Here we report that a distributed pressure sensing mechanism has the capability to discriminate Kármán vortex streets from uniform flows, and determine the orientation and position of the platform with respect to the incoming flow and the centre axis of the Kármán vortex street. It also enables the computation of hydrodynamic features which may be relevant for a robot while interacting with the flow, such as vortex shedding frequency, vortex travelling speed and downstream distance between vortices. A Kármán vortex street was distinguished in this study from uniform flows by analysing the magnitude of fluctuations present in the sensor measurements and the number of sensors detecting the same dominant frequency. In the Kármán vortex street the turbulence intensity was 30% higher than that in the uniform flow and the sensors collectively sensed the vortex shedding frequency as the dominant frequency. The position and orientation of the sensor platform were determined via a comparative analysis between laterally distributed sensor arrays; the vortex travelling speed was estimated via a cross-correlation analysis among the sensors. (paper)

Compressed sensing for distributed systems

CERN Document Server

Coluccia, Giulio; Magli, Enrico

2015-01-01

This book presents a survey of the state-of-the art in the exciting and timely topic of compressed sensing for distributed systems. It has to be noted that, while compressed sensing has been studied for some time now, its distributed applications are relatively new. Remarkably, such applications are ideally suited to exploit all the benefits that compressed sensing can provide. The objective of this book is to provide the reader with a comprehensive survey of this topic, from the basic concepts to different classes of centralized and distributed reconstruction algorithms, as well as a comparison of these techniques. This book collects different contributions on these aspects. It presents the underlying theory in a complete and unified way for the first time, presenting various signal models and their use cases. It contains a theoretical part collecting latest results in rate-distortion analysis of distributed compressed sensing, as well as practical implementations of algorithms obtaining performance close to...

A hydrostatic leak test for water pipeline by using distributed optical fiber vibration sensing system

Science.gov (United States)

Wu, Huijuan; Sun, Zhenshi; Qian, Ya; Zhang, Tao; Rao, Yunjiang

2015-07-01

A hydrostatic leak test for water pipeline with a distributed optical fiber vibration sensing (DOVS) system based on the phase-sensitive OTDR technology is studied in this paper. By monitoring one end of a common communication optical fiber cable, which is laid in the inner wall of the pipe, we can detect and locate the water leakages easily. Different apertures under different pressures are tested and it shows that the DOVS has good responses when the aperture is equal or larger than 4 mm and the inner pressure reaches 0.2 Mpa for a steel pipe with DN 91cm×EN 2cm.

Ultrafast Dynamic Pressure Sensors Based on Graphene Hybrid Structure.

Science.gov (United States)

Liu, Shanbiao; Wu, Xing; Zhang, Dongdong; Guo, Congwei; Wang, Peng; Hu, Weida; Li, Xinming; Zhou, Xiaofeng; Xu, Hejun; Luo, Chen; Zhang, Jian; Chu, Junhao

2017-07-19

Mechanical flexible electronic skin has been focused on sensing various physical parameters, such as pressure and temperature. The studies of material design and array-accessible devices are the building blocks of strain sensors for subtle pressure sensing. Here, we report a new and facile preparation of a graphene hybrid structure with an ultrafast dynamic pressure response. Graphene oxide nanosheets are used as a surfactant to prevent graphene restacking in aqueous solution. This graphene hybrid structure exhibits a frequency-independent pressure resistive sensing property. Exceeding natural skin, such pressure sensors, can provide transient responses from static up to 10 000 Hz dynamic frequencies. Integrated by the controlling system, the array-accessible sensors can manipulate a robot arm and self-rectify the temperature of a heating blanket. This may pave a path toward the future application of graphene-based wearable electronics.

Novel Tactile Sensor Technology and Smart Tactile Sensing Systems: A Review.

Science.gov (United States)

Zou, Liang; Ge, Chang; Wang, Z Jane; Cretu, Edmond; Li, Xiaoou

2017-11-17

During the last decades, smart tactile sensing systems based on different sensing techniques have been developed due to their high potential in industry and biomedical engineering. However, smart tactile sensing technologies and systems are still in their infancy, as many technological and system issues remain unresolved and require strong interdisciplinary efforts to address them. This paper provides an overview of smart tactile sensing systems, with a focus on signal processing technologies used to interpret the measured information from tactile sensors and/or sensors for other sensory modalities. The tactile sensing transduction and principles, fabrication and structures are also discussed with their merits and demerits. Finally, the challenges that tactile sensing technology needs to overcome are highlighted.

Novel Tactile Sensor Technology and Smart Tactile Sensing Systems: A Review

Directory of Open Access Journals (Sweden)

Liang Zou

2017-11-01

Full Text Available During the last decades, smart tactile sensing systems based on different sensing techniques have been developed due to their high potential in industry and biomedical engineering. However, smart tactile sensing technologies and systems are still in their infancy, as many technological and system issues remain unresolved and require strong interdisciplinary efforts to address them. This paper provides an overview of smart tactile sensing systems, with a focus on signal processing technologies used to interpret the measured information from tactile sensors and/or sensors for other sensory modalities. The tactile sensing transduction and principles, fabrication and structures are also discussed with their merits and demerits. Finally, the challenges that tactile sensing technology needs to overcome are highlighted.

Bridge SHM system based on fiber optical sensing technology

Science.gov (United States)

Li, Sheng; Fan, Dian; Fu, Jiang-hua; Huang, Xing; Jiang, De-sheng

2015-09-01

The latest progress of our lab in recent 10 years on the area of bridge structural health monitoring (SHM) based on optical fiber sensing technology is introduced. Firstly, in the part of sensing technology, optical fiber force test-ring, optical fiber vibration sensor, optical fiber smart cable, optical fiber prestressing loss monitoring method and optical fiber continuous curve mode inspection system are developed, which not only rich the sensor types, but also provides new monitoring means that are needed for the bridge health monitoring system. Secondly, in the optical fiber sensing network and computer system platform, the monitoring system architecture model is designed to effectively meet the integration scale and effect requirement of engineering application, especially the bridge expert system proposed integration of sensing information and informatization manual inspection to realize the mode of multi index intelligence and practical monitoring, diagnosis and evaluation. Finally, the Jingyue bridge monitoring system as the representative, the research on the technology of engineering applications are given.

Chemical sensing underclothing system for testing PPE

International Nuclear Information System (INIS)

Slabotinsky, J.; Kralik, L.; Bradka, S.; Castulik, P.

2009-01-01

Personal protective equipment (PPE) when worn is subjected to pressure differentials across the garment due to ambient wind flow, by body movement and breathing creating the bellows effect, which may force hazardous chemicals vapor or aerosol through the closures, joints, outlet valves and/or clothing protective fabric. Thus the design, fit, size or improper donning of the protective garment will influence chemical-agent penetration. In order to determine penetration of chemical-protective garments by chemical vapor or aerosol, it is necessary to test the entire suit system, including seams, closures, outlet valves and areas of transition with other protective equipment, that is, at the ankles, waist, wrists, neck etc. In order to identify penetration of chemical vapor or aerosol through protective assembly, the Man-in-Simulant Test (MIST) with passive adsorptive devices (PADs) is used, when adsorbed challenging agent (simulant) is desorbed from the PAD and quantified. The current MIST method is failing in complexity of leak detection, due to limited number of passive collection points fixed on human body or a mannequin and very labor extensive work associated with allocation of 20-40 PADs and quantification of adsorbed agent. The Czech approach to detect and quantify penetration/permeation of chemical agent is based on chemical sensing underclothing enable to change the color when exposed with simulant or even with real CW agent. Color intensity and shape of stains on sensing fabric are processed with Laboratory Universal Computer Image Analysis (LUCIA) allowing determining the quantity and the allocation of the penetrating noxious agent(s). This method allows for example calculate individual doses of exposure, the breakthrough coefficient of protective garment as whole and uniquely precise allocation of penetration/permeation shortfalls. Presentation is providing detailed description of imaging system with nickname 'LUCY' in combination with testing mannequin

Unmanned Aerial System Aids Dry-season Stream Temperature Sensing

Science.gov (United States)

Chung, M.; Detweiler, C.; Higgins, J.; Ore, J. P.; Dralle, D.; Thompson, S. E.

2016-12-01

In freshwater ecosystems, temperature affects biogeochemistry and ecology, and is thus a primary physical determinant of habitat quality. Measuring temperatures in spatially heterogeneous water bodies poses a serious challenge to researchers due to constraints associated with currently available methods: in situ loggers record temporally continuous temperature measurements but are limited to discrete spatial locations, while distributed temperature and remote sensing provide fine-resolution spatial measurements that are restricted to only two-dimensions (i.e. streambed and surface, respectively). Using a commercially available quadcopter equipped with a 6m cable and temperature-pressure sensor system, we measured stream temperatures at two confluences at the South Fork Eel River, where cold water inputs from the tributary to the mainstem create thermal refugia for juvenile salmonids during the dry season. As a mobile sensing platform, unmanned aerial systems (UAS) can facilitate quick and repeated sampling with minimal disturbance to the ecosystem, and their datasets can be interpolated to create a three-dimensional thermal map of a water body. The UAS-derived data was compared to data from in situ data loggers to evaluate whether the UAS is better able to capture fine-scale temperature dynamics at each confluence. The UAS has inherent limitations defined by battery life and flight times, as well as operational constraints related to maneuverability under wind and streamflow conditions. However, the platform is able to serve as an additional field tool for researchers to capture complex thermal structures in water bodies.

Energy Systems High-Pressure Test Laboratory | Energy Systems Integration

Science.gov (United States)

Facility | NREL Energy Systems High-Pressure Test Laboratory Energy Systems High-Pressure Test Laboratory In the Energy Systems Integration Facility's High-Pressure Test Laboratory, researchers can safely test high-pressure hydrogen components. Photo of researchers running an experiment with a hydrogen fuel

A temperature and pressure controlled calibration system for pressure sensors

Science.gov (United States)

Chapman, John J.; Kahng, Seun K.

1989-01-01

A data acquisition and experiment control system capable of simulating temperatures from -184 to +220 C and pressures either absolute or differential from 0 to 344.74 kPa is developed to characterize silicon pressure sensor response to temperature and pressure. System software is described that includes sensor data acquisition, algorithms for numerically derived thermal offset and sensitivity correction, and operation of the environmental chamber and pressure standard. This system is shown to be capable of computer interfaced cryogenic testing to within 1 C and 34.47 Pa of single channel or multiplexed arrays of silicon pressure sensors.

Flexible Ferroelectric Sensors with Ultrahigh Pressure Sensitivity and Linear Response over Exceptionally Broad Pressure Range.

Science.gov (United States)

Lee, Youngoh; Park, Jonghwa; Cho, Soowon; Shin, Young-Eun; Lee, Hochan; Kim, Jinyoung; Myoung, Jinyoung; Cho, Seungse; Kang, Saewon; Baig, Chunggi; Ko, Hyunhyub

2018-04-24

Flexible pressure sensors with a high sensitivity over a broad linear range can simplify wearable sensing systems without additional signal processing for the linear output, enabling device miniaturization and low power consumption. Here, we demonstrate a flexible ferroelectric sensor with ultrahigh pressure sensitivity and linear response over an exceptionally broad pressure range based on the material and structural design of ferroelectric composites with a multilayer interlocked microdome geometry. Due to the stress concentration between interlocked microdome arrays and increased contact area in the multilayer design, the flexible ferroelectric sensors could perceive static/dynamic pressure with high sensitivity (47.7 kPa -1 , 1.3 Pa minimum detection). In addition, efficient stress distribution between stacked multilayers enables linear sensing over exceptionally broad pressure range (0.0013-353 kPa) with fast response time (20 ms) and high reliability over 5000 repetitive cycles even at an extremely high pressure of 272 kPa. Our sensor can be used to monitor diverse stimuli from a low to a high pressure range including weak gas flow, acoustic sound, wrist pulse pressure, respiration, and foot pressure with a single device.

Temporal compressive sensing systems

Science.gov (United States)

Reed, Bryan W.

2017-12-12

Methods and systems for temporal compressive sensing are disclosed, where within each of one or more sensor array data acquisition periods, one or more sensor array measurement datasets comprising distinct linear combinations of time slice data are acquired, and where mathematical reconstruction allows for calculation of accurate representations of the individual time slice datasets.

Modeling low pressure baroreceptors and their contribution to blood pressure control

Directory of Open Access Journals (Sweden)

Sánchez de Zambrano, Betsy Mirley

2016-10-01

Full Text Available The main mechanism for blood pressure (BP control is coordinated by the central nervous system through the sympathetic and parasympathetic systems. In order to simulate this mechanism, different mathematical models are available, but they take into account only the high pressure receptors as sensing systems for BP. However, other receptors located in low pressure areas have not, as far as we know, been considered in the models described in the literature, despite their important role in the nervous BP control. This paper presents a mathematical model for the representation of low pressure receptors by means of the detection of atrial volume changes, and their contribution to immediate BP control through nervous stimulation of the heart rate. The proposed model was coupled to the sensor mechanism of a larger model. With this model it is possible to analyze the contribution and behavior of low pressure receptors, thus allowing a better understanding of this complex system under normal and pathological conditions, since it includes important variables in the immediate BP control, not included in previous models.

Method and Apparatus for Characterizing Pressure Sensors using Modulated Light Beam Pressure

Science.gov (United States)

Youngquist, Robert C. (Inventor)

2003-01-01

Embodiments of apparatuses and methods are provided that use light sources instead of sound sources for characterizing and calibrating sensors for measuring small pressures to mitigate many of the problems with using sound sources. In one embodiment an apparatus has a light source for directing a beam of light on a sensing surface of a pressure sensor for exerting a force on the sensing surface. The pressure sensor generates an electrical signal indicative of the force exerted on the sensing surface. A modulator modulates the beam of light. A signal processor is electrically coupled to the pressure sensor for receiving the electrical signal.

Multi-source remote sensing data management system

International Nuclear Information System (INIS)

Qin Kai; Zhao Yingjun; Lu Donghua; Zhang Donghui; Wu Wenhuan

2014-01-01

In this thesis, the author explored multi-source management problems of remote sensing data. The main idea is to use the mosaic dataset model, and the ways of an integreted display of image and its interpretation. Based on ArcGIS and IMINT feature knowledge platform, the author used the C# and other programming tools for development work, so as to design and implement multi-source remote sensing data management system function module which is able to simply, conveniently and efficiently manage multi-source remote sensing data. (authors)

ATRAN Terrain Sensing Guidance-The Grand-Daddy System

Science.gov (United States)

Koch, Richard F.; Evans, Donald C.

1980-12-01

ATRAN was the pioneer terrain sensing guidance system developed in the 1950 era and deployed in Europe on the Air Force's mobile, ground launched TM-76A MACE cruise missile in the late 1950's and early 1960's. The background, principles and technology are described for this system which was the forerunner of todays modern autonomous standoff terrain sensing guided weapons.

Feasibility of Locating Leakages in Sewage Pressure Pipes Using the Distributed Temperature Sensing Technology

OpenAIRE

Apperl, Benjamin; Pressl, Alexander; Schulz, Karsten

2017-01-01

The cost effective maintenance of underwater pressure pipes for sewage disposal in Austria requires the detection and localization of leakages. Extrusion of wastewater in lakes can heavily influence the water and bathing quality of surrounding waters. The Distributed Temperature Sensing (DTS) technology is a widely used technique for oil and gas pipeline leakage detection. While in pipeline leakage detection, fiber optic cables are installed permanently at the outside or within the protective...

A software architecture for adaptive modular sensing systems.

Science.gov (United States)

Lyle, Andrew C; Naish, Michael D

2010-01-01

By combining a number of simple transducer modules, an arbitrarily complex sensing system may be produced to accommodate a wide range of applications. This work outlines a novel software architecture and knowledge representation scheme that has been developed to support this type of flexible and reconfigurable modular sensing system. Template algorithms are used to embed intelligence within each module. As modules are added or removed, the composite sensor is able to automatically determine its overall geometry and assume an appropriate collective identity. A virtual machine-based middleware layer runs on top of a real-time operating system with a pre-emptive kernel, enabling platform-independent template algorithms to be written once and run on any module, irrespective of its underlying hardware architecture. Applications that may benefit from easily reconfigurable modular sensing systems include flexible inspection, mobile robotics, surveillance, and space exploration.

Development and applicability estimation of the tire contact pressure measurement system; Tire secchiatsukei no kaihatsu to oyosei hyoka

Energy Technology Data Exchange (ETDEWEB)

Mizutani, Y.; Amago, T.; Takahashi, T.; Sakuma, S.; Mori, N. [Toyota Central R and D Laboratories, Inc., Aichi (Japan); Nagae, A. [Toyota Motor Corp., Aichi (Japan); Yasuoka, M. [Toyo Tire and Rubber Co. Ltd., Osaka (Japan)

1995-04-20

A pressure sensor more reliable than the conventional types and a tire pressure measurement system using a plurality of sensors of the said reliable type have been developed. The sensor is an inverted T in shape, the upper surface of the vertical beam thereof receives the pressure, and the two ends of the horizontal beam are fixed. The load per unit area imposed on the pressure receiving surface is separated into three components, the X and Y components in the tangential direction are sensed by the vertical beam while the Z component in the vertical direction is sensed by a distortion gauge attached to the horizontal beam. For the measurement of the contact pressure distribution for the entire contact surface, a measuring device was developed, comprising a multiple point contact pressure gauge with 30 sensors of the reliable type discussed here embedded therein, a tire rolling tester, and a data processing unit. A tire wear estimation test was conducted using this pressure sensor and a contact probe type slip sensor, and it was found that a tire of a greater friction energy ratio is easier to experience abnormal abrasion and that the new pressure sensor is useful in estimating abnormal abrasion. Further, it was indicated that the present measuring device is applicable to the analysis of the mechanism wherein shaft force results from contact pressure on the soil. 3 refs., 11 figs., 3 tabs.

Feasibility of Locating Leakages in Sewage Pressure Pipes Using the Distributed Temperature Sensing Technology.

Science.gov (United States)

Apperl, Benjamin; Pressl, Alexander; Schulz, Karsten

2017-01-01

The cost effective maintenance of underwater pressure pipes for sewage disposal in Austria requires the detection and localization of leakages. Extrusion of wastewater in lakes can heavily influence the water and bathing quality of surrounding waters. The Distributed Temperature Sensing (DTS) technology is a widely used technique for oil and gas pipeline leakage detection. While in pipeline leakage detection, fiber optic cables are installed permanently at the outside or within the protective sheathing of the pipe; this paper aims at testing the feasibility of detecting leakages with temporary introduced fiber optic cable inside the pipe. The detection and localization were tested in a laboratory experiment. The intrusion of water from leakages into the pipe, producing a local temperature drop, served as indicator for leakages. Measurements were taken under varying measurement conditions, including the number of leakages as well as the positioning of the fiber optic cable. Experiments showed that leakages could be detected accurately with the proposed methodology, when measuring resolution, temperature gradient and measurement time were properly selected. Despite the successful application of DTS for leakage detection in this lab environment, challenges in real system applications may arise from temperature gradients within the pipe system over longer distances and the placement of the cable into the real pipe system.

A Software Architecture for Adaptive Modular Sensing Systems

Directory of Open Access Journals (Sweden)

Andrew C. Lyle

2010-08-01

Full Text Available By combining a number of simple transducer modules, an arbitrarily complex sensing system may be produced to accommodate a wide range of applications. This work outlines a novel software architecture and knowledge representation scheme that has been developed to support this type of flexible and reconfigurable modular sensing system. Template algorithms are used to embed intelligence within each module. As modules are added or removed, the composite sensor is able to automatically determine its overall geometry and assume an appropriate collective identity. A virtual machine-based middleware layer runs on top of a real-time operating system with a pre-emptive kernel, enabling platform-independent template algorithms to be written once and run on any module, irrespective of its underlying hardware architecture. Applications that may benefit from easily reconfigurable modular sensing systems include flexible inspection, mobile robotics, surveillance, and space exploration.

Use of remotely sensed data to evaluate the relationship between living environment and blood pressure.

Science.gov (United States)

Estes, Maurice G; Al-Hamdan, Mohammad Z; Crosson, William; Estes, Sue M; Quattrochi, Dale; Kent, Shia; McClure, Leslie Ain

2009-12-01

Urbanization has been correlated with hypertension (HTN) in developing countries undergoing rapid economic and environmental transitions. We examined the relationships among living environment (urban, suburban, and rural), day/night land surface temperatures (LST), and blood pressure in selected regions from the REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort. Also, the linking of data on blood pressure from REGARDS with National Aeronautics and Space Administration (NASA) science data is relevant to NASA's strategic goals and missions, particularly as a primary focus of the agency's Applied Sciences Program. REGARDS is a national cohort of 30,228 people from the 48 contiguous United States with self-reported and measured blood pressure levels. Four metropolitan regions (Philadelphia, PA; Atlanta, GA; Minneapolis, MN; and Chicago, IL) with varying geographic and health characteristics were selected for study. Satellite remotely sensed data were used to characterize the LST and land cover/land use (LCLU) environment for each area. We developed a method for characterizing participants as living in urban, suburban, or rural living environments, using the LCLU data. These data were compiled on a 1-km grid for each region and linked with the REGARDS data via an algorithm using geocoding information. REGARDS participants in urban areas have higher systolic and diastolic blood pressure than do those in suburban or rural areas, and also a higher incidence of HTN. In univariate models, living environment is associated with HTN, but after adjustment for known HTN risk factors, the relationship was no longer present. Further study regarding the relationship between HTN and living environment should focus on additional environmental characteristics, such as air pollution. The living environment classification method using remotely sensed data has the potential to facilitate additional research linking environmental variables to public health concerns.

Switching strategy between HP (high pressure)- and LPEGR (low pressure exhaust gas recirculation) systems for reduced fuel consumption and emissions

International Nuclear Information System (INIS)

Luján, José Manuel; Guardiola, Carlos; Pla, Benjamín; Reig, Alberto

2015-01-01

EGR (Exhaust gas recirculation) plays a major role in current Diesel internal combustion engines as a cost-effective solution to reduce NO_x emissions. EGR systems will suffer a significant evolution with the introduction of NO_x after-treatment and the proliferation of more complex EGR architectures such as low pressure EGR or dual EGR. In this paper the combination of HPEGR (high pressure EGR) LPEGR (low pressure EGR) is presented as a method to minimise fuel consumption with reduced NO_x emissions. Particularly, the paper proposes to switch between HPEGR and LPEGR architectures depending on the engine operating conditions in order to exploit the potential of both systems. In this sense, given a driving cycle, in the case at hand the NEDC, the proposed strategy seeks the EGR layout to use at each instant of the cycle to minimise the fuel consumption such that NO_x emissions are kept below a certain limit. The experimental results obtained show that combining both EGR systems sequentially along the NEDC allows to keep NO_x emission below a much lower limit with minimum fuel consumption. - Highlights: • The combination of HP–LPEGR reduces the NO_x with a small impact on consumption. • The switching strategy between HP – LPEGR is derived from Optimal Control Theory. • The proposed strategy is validated experimentally.

49 CFR 192.621 - Maximum allowable operating pressure: High-pressure distribution systems.

Science.gov (United States)

2010-10-01

... STANDARDS Operations § 192.621 Maximum allowable operating pressure: High-pressure distribution systems. (a) No person may operate a segment of a high pressure distribution system at a pressure that exceeds the... segment of a distribution system otherwise designed to operate at over 60 p.s.i. (414 kPa) gage, unless...

An Implantable Cardiovascular Pressure Monitoring System with On-Chip Antenna and RF Energy Harvesting

Directory of Open Access Journals (Sweden)

Yu-Chun Liu

2015-08-01

Full Text Available An implantable wireless system with on-chip antenna for cardiovascular pressure monitor is studied. The implantable device is operated in a batteryless manner, powered by an external radio frequency (RF power source. The received RF power level can be sensed and wirelessly transmitted along with blood pressure signal for feedback control of the external RF power. The integrated electronic system, consisting of a capacitance-to-voltage converter, an adaptive RF powering system, an RF transmitter and digital control circuitry, is simulated using a TSMC 0.18 μm CMOS technology. The implanted RF transmitter circuit is combined with a low power voltage-controlled oscillator resonating at 5.8 GHz and a power amplifier. For the design, the simulation model is setup using ADS and HFSS software. The dimension of the antenna is 1 × 0.6 × 4.8 mm3 with a 1 × 0.6 mm2 on-chip circuit which is small enough to place in human carotid artery.

Liquid Level Sensing System

Science.gov (United States)

Korman, Valentin (Inventor); Wiley, John T. (Inventor); Duffell, Amanda G. (Inventor)

2014-01-01

A liquid level sensing system includes waveguides disposed in a liquid and distributed along a path with a gap between adjacent waveguides. A source introduces electromagnetic energy into the waveguides at a first end of the path. A portion of the electromagnetic energy exits the waveguides at a second end of the path. A detector measures the portion of the electromagnetic energy exiting the second end of the path.

Flexible hemispheric microarrays of highly pressure-sensitive sensors based on breath figure method.

Science.gov (United States)

Wang, Zhihui; Zhang, Ling; Liu, Jin; Jiang, Hao; Li, Chunzhong

2018-05-30

Recently, flexible pressure sensors featuring high sensitivity, broad sensing range and real-time detection have aroused great attention owing to their crucial role in the development of artificial intelligent devices and healthcare systems. Herein, highly sensitive pressure sensors based on hemisphere-microarray flexible substrates are fabricated via inversely templating honeycomb structures deriving from a facile and static breath figure process. The interlocked and subtle microstructures greatly improve the sensing characteristics and compressibility of the as-prepared pressure sensor, endowing it a sensitivity as high as 196 kPa-1 and a wide pressure sensing range (0-100 kPa), as well as other superior performance, including a lower detection limit of 0.5 Pa, fast response time (10 000 cycles). Based on the outstanding sensing performance, the potential capability of our pressure sensor in capturing physiological information and recognizing speech signals has been demonstrated, indicating promising application in wearable and intelligent electronics.

A Ground Systems Template for Remote Sensing Systems

Science.gov (United States)

McClanahan, Timothy P.; Trombka, Jacob I.; Floyd, Samuel R.; Truskowski, Walter; Starr, Richard D.; Clark, Pamela E.; Evans, Larry G.

2002-10-01

Spaceborne remote sensing using gamma and X-ray spectrometers requires particular attention to the design and development of reliable systems. These systems must ensure the scientific requirements of the mission within the challenging technical constraints of operating instrumentation in space. The Near Earth Asteroid Rendezvous (NEAR) spacecraft included X-ray and gamma-ray spectrometers (XGRS), whose mission was to map the elemental chemistry of the 433 Eros asteroid. A remote sensing system template, similar to a blackboard systems approach used in artificial intelligence, was identified in which the spacecraft, instrument, and ground system was designed and developed to monitor and adapt to evolving mission requirements in a complicated operational setting. Systems were developed for ground tracking of instrument calibration, instrument health, data quality, orbital geometry, solar flux as well as models of the asteroid's surface characteristics, requiring an intensive human effort. In the future, missions such as the Autonomous Nano-Technology Swarm (ANTS) program will have to rely heavily on automation to collectively encounter and sample asteroids in the outer asteroid belt. Using similar instrumentation, ANTS will require information similar to data collected by the NEAR X-ray/Gamma-Ray Spectrometer (XGRS) ground system for science and operations management. The NEAR XGRS systems will be studied to identify the equivalent subsystems that may be automated for ANTS. The effort will also investigate the possibility of applying blackboard style approaches to automated decision making required for ANTS.

A ground systems template for remote sensing systems

International Nuclear Information System (INIS)

McClanahan, Timothy P.; Trombka, Jacob I.; Floyd, Samuel R.; Truskowski, Walter; Starr, Richard D.; Clark, Pamela E.; Evans, Larry G.

2002-01-01

Spaceborne remote sensing using gamma and X-ray spectrometers requires particular attention to the design and development of reliable systems. These systems must ensure the scientific requirements of the mission within the challenging technical constraints of operating instrumentation in space. The Near Earth Asteroid Rendezvous (NEAR) spacecraft included X-ray and gamma-ray spectrometers (XGRS), whose mission was to map the elemental chemistry of the 433 Eros asteroid. A remote sensing system template, similar to a blackboard systems approach used in artificial intelligence, was identified in which the spacecraft, instrument, and ground system was designed and developed to monitor and adapt to evolving mission requirements in a complicated operational setting. Systems were developed for ground tracking of instrument calibration, instrument health, data quality, orbital geometry, solar flux as well as models of the asteroid's surface characteristics, requiring an intensive human effort. In the future, missions such as the Autonomous Nano-Technology Swarm (ANTS) program will have to rely heavily on automation to collectively encounter and sample asteroids in the outer asteroid belt. Using similar instrumentation, ANTS will require information similar to data collected by the NEAR X-ray/Gamma-Ray Spectrometer (XGRS) ground system for science and operations management. The NEAR XGRS systems will be studied to identify the equivalent subsystems that may be automated for ANTS. The effort will also investigate the possibility of applying blackboard style approaches to automated decision making required for ANTS

Highly Integrated MEMS-ASIC Sensing System for Intracorporeal Physiological Condition Monitoring.

Science.gov (United States)

Xue, Ning; Wang, Chao; Liu, Cunxiu; Sun, Jianhai

2018-01-02

In this paper, a highly monolithic-integrated multi-modality sensor is proposed for intracorporeal monitoring. The single-chip sensor consists of a solid-state based temperature sensor, a capacitive based pressure sensor, and an electrochemical oxygen sensor with their respective interface application-specific integrated circuits (ASICs). The solid-state-based temperature sensor and the interface ASICs were first designed and fabricated based on a 0.18-μm 1.8-V CMOS (complementary metal-oxide-semiconductor) process. The oxygen sensor and pressure sensor were fabricated by the standard CMOS process and subsequent CMOS-compatible MEMS (micro-electromechanical systems) post-processing. The multi-sensor single chip was completely sealed by the nafion, parylene, and PDMS (polydimethylsiloxane) layers for biocompatibility study. The size of the compact sensor chip is only 3.65 mm × 1.65 mm × 0.72 mm. The functionality, stability, and sensitivity of the multi-functional sensor was tested ex vivo. Cytotoxicity assessment was performed to verify that the bio-compatibility of the device is conforming to the ISO 10993-5:2009 standards. The measured sensitivities of the sensors for the temperature, pressure, and oxygen concentration are 10.2 mV/°C, 5.58 mV/kPa, and 20 mV·L/mg, respectively. The measurement results show that the proposed multi-sensor single chip is suitable to sense the temperature, pressure, and oxygen concentration of human tissues for intracorporeal physiological condition monitoring.

Remote shock sensing and notification system

Science.gov (United States)

Muralidharan, Govindarajan; Britton, Charles L.; Pearce, James; Jagadish, Usha; Sikka, Vinod K.

2008-11-11

A low-power shock sensing system includes at least one shock sensor physically coupled to a chemical storage tank to be monitored for impacts, and an RF transmitter which is in a low-power idle state in the absence of a triggering signal. The system includes interference circuitry including or activated by the shock sensor, wherein an output of the interface circuitry is coupled to an input of the RF transmitter. The interface circuitry triggers the RF transmitting with the triggering signal to transmit an alarm message to at least one remote location when the sensor senses a shock greater than a predetermined threshold. In one embodiment the shock sensor is a shock switch which provides an open and a closed state, the open state being a low power idle state.

Remote Sensing Wind and Wind Shear System.

Science.gov (United States)

Contents: Remote sensing of wind shear and the theory and development of acoustic doppler; Wind studies; A comparison of methods for the remote detection of winds in the airport environment; Acoustic doppler system development; System calibration; Airport operational tests.

CYBERNETIC BASIS AND SYSTEM PRACTICE OF REMOTE SENSING AND SPATIAL INFORMATION SCIENCE

Directory of Open Access Journals (Sweden)

X. Tan

2017-09-01

Full Text Available Cybernetics provides a new set of ideas and methods for the study of modern science, and it has been fully applied in many areas. However, few people have introduced cybernetics into the field of remote sensing. The paper is based on the imaging process of remote sensing system, introducing cybernetics into the field of remote sensing, establishing a space-time closed-loop control theory for the actual operation of remote sensing. The paper made the process of spatial information coherently, and improved the comprehensive efficiency of the space information from acquisition, procession, transformation to application. We not only describes the application of cybernetics in remote sensing platform control, sensor control, data processing control, but also in whole system of remote sensing imaging process control. We achieve the information of output back to the input to control the efficient operation of the entire system. This breakthrough combination of cybernetics science and remote sensing science will improve remote sensing science to a higher level.

Cybernetic Basis and System Practice of Remote Sensing and Spatial Information Science

Science.gov (United States)

Tan, X.; Jing, X.; Chen, R.; Ming, Z.; He, L.; Sun, Y.; Sun, X.; Yan, L.

2017-09-01

Cybernetics provides a new set of ideas and methods for the study of modern science, and it has been fully applied in many areas. However, few people have introduced cybernetics into the field of remote sensing. The paper is based on the imaging process of remote sensing system, introducing cybernetics into the field of remote sensing, establishing a space-time closed-loop control theory for the actual operation of remote sensing. The paper made the process of spatial information coherently, and improved the comprehensive efficiency of the space information from acquisition, procession, transformation to application. We not only describes the application of cybernetics in remote sensing platform control, sensor control, data processing control, but also in whole system of remote sensing imaging process control. We achieve the information of output back to the input to control the efficient operation of the entire system. This breakthrough combination of cybernetics science and remote sensing science will improve remote sensing science to a higher level.

Advanced Power Management of a Telehandler using Electronic Load Sensing

DEFF Research Database (Denmark)

Hansen, Rico Hjerm

2009-01-01

New possibilities within electronic control of mobile hydraulic systems are becoming available as hydraulic components are implemented with more electrical sensors and actuators. This paper presents how the traditional hydro-mechanical load sensing (HLS) control of a specific mobile hydraulic...... application, a telehandler, can be replaced with electronic control, i.e. Electronic Load Sensing (ELS). The motivation for ELS is the potentials of better dynamic performance and system utilization, along with reduced mechanical complexity by transferring features as pump pressure control, flow...

High pressure fiber optic sensor system

Science.gov (United States)

Guida, Renato; Xia, Hua; Lee, Boon K; Dekate, Sachin N

2013-11-26

The present application provides a fiber optic sensor system. The fiber optic sensor system may include a small diameter bellows, a large diameter bellows, and a fiber optic pressure sensor attached to the small diameter bellows. Contraction of the large diameter bellows under an applied pressure may cause the small diameter bellows to expand such that the fiber optic pressure sensor may measure the applied pressure.

RSComPro: An Open Communication Protocol for Remote Sensing Systems

DEFF Research Database (Denmark)

Vasiljevic, Nikola; Trujillo, Juan-José

The remote sensing protocol (RSComPro) is a communication protocol, which has been developed for controlling multiple remote sensing systems simultaneously through a UDP/IP and TPC/IP network. This protocol is meant to be open to the remote sensing community. The scope is the implementation of so...

Active Sensing Air Pressure Using Differential Absorption Barometric Radar

Science.gov (United States)

Lin, B.

2016-12-01

Tropical storms and other severe weathers cause huge life losses and property damages and have major impacts on public safety and national security. Their observations and predictions need to be significantly improved. This effort tries to develop a feasible active microwave approach that measures surface air pressure, especially over open seas, from space using a Differential-absorption BArometric Radar (DiBAR) operating at 50-55 GHz O2 absorption band in order to constrain assimilated dynamic fields of numerical weather Prediction (NWP) models close to actual conditions. Air pressure is the most important variable that drives atmospheric dynamics, and currently can only be measured by limited in-situ observations over oceans. Even over land there is no uniform coverage of surface air pressure measurements. Analyses show that with the proposed space radar the errors in instantaneous (averaged) pressure estimates can be as low as 4mb ( 1mb) under all weather conditions. NASA Langley research team has made substantial progresses in advancing the DiBAR concept. The feasibility assessment clearly shows the potential of surface barometry using existing radar technologies. The team has also developed a DiBAR system design, fabricated a Prototype-DiBAR (P-DiBAR) for proof-of-concept, conducted laboratory, ground and airborne P-DiBAR tests. The flight test results are consistent with the instrumentation goals. The precision and accuracy of radar surface pressure measurements are within the range of the theoretical analysis of the DiBAR concept. Observational system simulation experiments for space DiBAR performance based on the existing DiBAR technology and capability show substantial improvements in tropical storm predictions, not only for the hurricane track and position but also for the hurricane intensity. DiBAR measurements will provide us an unprecedented level of the prediction and knowledge on global extreme weather and climate conditions.

49 CFR 192.623 - Maximum and minimum allowable operating pressure; Low-pressure distribution systems.

Science.gov (United States)

2010-10-01

... distribution systems. (a) No person may operate a low-pressure distribution system at a pressure high enough to...) No person may operate a low pressure distribution system at a pressure lower than the minimum... 49 Transportation 3 2010-10-01 2010-10-01 false Maximum and minimum allowable operating pressure...

DEVICE FOR CONTROL OF OXYGEN PARTIAL PRESSURE

Science.gov (United States)

Bradner, H.; Gordon, H.S.

1957-12-24

A device is described that can sense changes in oxygen partial pressure and cause a corresponding mechanical displacement sufficient to actuate meters, valves and similar devices. A piston and cylinder arrangement contains a charge of crystalline metal chelate pellets which have the peculiar property of responding to variations in the oxygen content of the ambient atmosphere by undergoing a change in dimension. A lever system amplifies the relative displacement of the piston in the cylinder, and actuates the controlled valving device. This partial pressure oxygen sensing device is useful in controlled chemical reactions or in respiratory devices such as the oxygen demand meters for high altitude aircraft.

Systematic approach to development of pressure sensors using dielectric electro-active polymer membranes

International Nuclear Information System (INIS)

York, A; Seelecke, S; Dunn, J

2013-01-01

Dielectric electro-active polymers (DEAPs) have become attractive materials for various actuation and sensing applications due to their high energy and power density, high efficiency, light weight, and fast response speed. However, commercial development has been hindered due to a variety of constraints such as reliability, non-linear behavior, cost of driving electronics, and form factor requirements. This paper presents the systematic development from laboratory concept to commercial readiness of a novel pressure sensing system using a DEAP membrane. The pressure sensing system was designed for in-line pressure measurements for low pressure applications such as health systems monitoring. A first generation sensor was designed, built and tested with a focus on the qualitative capabilities of EAP membranes as sensors. Experimental measurements were conducted that demonstrated the capability of the sensor to output a voltage signal proportional to a changing pressure. Several undesirable characteristics were observed during these initial tests such as strong hysteresis, non-linearity, very limited pressure range, and low fatigue life. A second generation prototype was then designed to remove or compensate for these undesirable characteristics. This prototype was then built and tested. The new design showed an almost complete removal of hysteretic non-linear effects and was capable of operating at 10 × the pressure range of the initial generation. This new design is the framework for a novel DEAP based pressure sensor ready for commercial applications. (paper)

Performance of target detection algorithm in compressive sensing miniature ultraspectral imaging compressed sensing system

Science.gov (United States)

Gedalin, Daniel; Oiknine, Yaniv; August, Isaac; Blumberg, Dan G.; Rotman, Stanley R.; Stern, Adrian

2017-04-01

Compressive sensing theory was proposed to deal with the high quantity of measurements demanded by traditional hyperspectral systems. Recently, a compressive spectral imaging technique dubbed compressive sensing miniature ultraspectral imaging (CS-MUSI) was presented. This system uses a voltage controlled liquid crystal device to create multiplexed hyperspectral cubes. We evaluate the utility of the data captured using the CS-MUSI system for the task of target detection. Specifically, we compare the performance of the matched filter target detection algorithm in traditional hyperspectral systems and in CS-MUSI multiplexed hyperspectral cubes. We found that the target detection algorithm performs similarly in both cases, despite the fact that the CS-MUSI data is up to an order of magnitude less than that in conventional hyperspectral cubes. Moreover, the target detection is approximately an order of magnitude faster in CS-MUSI data.

A Novel Bioinspired PVDF Micro/Nano Hair Receptor for a Robot Sensing System

Directory of Open Access Journals (Sweden)

Xin Fu

2010-01-01

Full Text Available This paper describes the concept and design of a novel artificial hair receptor for the sensing system of micro intelligent robots such as a cricket-like jumping mini robot. The concept is inspired from the natural hair receptor of animals, also called cilium or filiform hair by different research groups, which is usually used as a vibration receptor or a flow detector by insects, mammals and fishes. The suspended fiber model is firstly built and the influence of scaling down is analyzed theoretically. The design of this artificial hair receptor is based on aligned suspended PVDF (polyvinylidene fluoride fibers, manufactures with a novel method called thermo-direct drawing technique, and aligned suspended submicron diameter fibers are thus successfully fabricated on a flexible Kapton. In the post process step, some key problems such as separated electrodes deposition along with the fiber drawing direction and poling of micro/nano fibers to impart them with good piezoeffective activity have been presented. The preliminary validation experiments show that the artificial hair receptor has a reliable response with good sensibility to external pressure variation and, medium flow as well as its prospects in the application on sensing system of mini/micro bio-robots.

Characterization of a compliant multi-layer system for tactile sensing with enhanced sensitivity and range

Science.gov (United States)

Chen, Ying; Yu, Miao; Bruck, Hugh A.; Smela, Elisabeth

2018-06-01

To allow robots to interact with humans via touch, new sensing concepts are needed that can detect a wide range of potential interactions and cover the body of a robot. In this paper, a skin-inspired multi-layer tactile sensing architecture is presented and characterized. The structure consists of stretchable piezoresistive strain-sensing layers over foam layers of different stiffness, allowing for both sufficient sensitivity and pressure range for human contacts. Strip-shaped sensors were used in this architecture to produce a deformation response proportional to pressure. The roles of the foam layers were elucidated by changing their stiffness and thickness, allowing the development of a geometric model to account for indenter interactions with the structure. The advantage of this architecture over other approaches is the ability to easily tune performance by adjusting the stiffness or thickness of the foams to tailor the response for different applications. Since viscoelastic materials were used, the temporal effects were also investigated.

In-situ Blockage Monitoring of Sensing Line

Directory of Open Access Journals (Sweden)

Aijaz Ahmed Mangi

2016-02-01

Full Text Available A reactor vessel level monitoring system measures the water level in a reactor during normal operation and abnormal conditions. A drop in the water level can expose nuclear fuel, which may lead to fuel meltdown and radiation spread in accident conditions. A level monitoring system mainly consists of a sensing line and pressure transmitter. Over a period of time boron sediments or other impurities can clog the line which may degrade the accuracy of the monitoring system. The aim of this study is to determine blockage in a sensing line using the energy of the composite signal. An equivalent Pi circuit model is used to simulate blockages in the sensing line and the system's response is examined under different blockage levels. Composite signals obtained from the model and plant's unblocked and blocked channels are decomposed into six levels of details and approximations using a wavelet filter bank. The percentage of energy is calculated at each level for approximations. It is observed that the percentage of energy reduces as the blockage level in the sensing line increases. The results of the model and operational data are well correlated. Thus, in our opinion variation in the energy levels of approximations can be used as an index to determine the presence and degree of blockage in a sensing line.

Soft sensing of system parameters in membrane distillation

KAUST Repository

Laleg-Kirati, Taous-Meriem

2017-01-01

Various examples of methods and systems are provided for soft sensing of system parameters in membrane distillation (MD). In one example, a system includes a MD module comprising a feed side and a permeate side separated by a membrane boundary layer

Pressure sensor based on distributed temperature sensing

NARCIS (Netherlands)

van Baar, J.J.J.; Wiegerink, Remco J.; Berenschot, Johan W.; Lammerink, Theodorus S.J.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt

2002-01-01

A differential pressure sensor has been realized with thermal readout. The thermal readout allows simultaneous measurement of the membrane deflection due to a pressure difference and measurement of the absolute pressure by operating the structure as a Pirani pressure sensor. The measuring of the

High precision relative position sensing system for formation flying spacecraft

Data.gov (United States)

National Aeronautics and Space Administration — We propose to develop and test an optical sensing system that provides high precision relative position sensing for formation flying spacecraft.  A high precision...

Enabling technologies for fiber optic sensing

Science.gov (United States)

Ibrahim, Selwan K.; Farnan, Martin; Karabacak, Devrez M.; Singer, Johannes M.

2016-04-01

In order for fiber optic sensors to compete with electrical sensors, several critical parameters need to be addressed such as performance, cost, size, reliability, etc. Relying on technologies developed in different industrial sectors helps to achieve this goal in a more efficient and cost effective way. FAZ Technology has developed a tunable laser based optical interrogator based on technologies developed in the telecommunication sector and optical transducer/sensors based on components sourced from the automotive market. Combining Fiber Bragg Grating (FBG) sensing technology with the above, high speed, high precision, reliable quasi distributed optical sensing systems for temperature, pressure, acoustics, acceleration, etc. has been developed. Careful design needs to be considered to filter out any sources of measurement drifts/errors due to different effects e.g. polarization and birefringence, coating imperfections, sensor packaging etc. Also to achieve high speed and high performance optical sensing systems, combining and synchronizing multiple optical interrogators similar to what has been used with computer/processors to deliver super computing power is an attractive solution. This path can be achieved by using photonic integrated circuit (PIC) technology which opens the doors to scaling up and delivering powerful optical sensing systems in an efficient and cost effective way.

Contrastive Analysis and Research on Negative Pressure Beam Tube System and Positive Pressure Beam Tube System for Mine Use

Science.gov (United States)

Wang, Xinyi; Shen, Jialong; Liu, Xinbo

2018-01-01

Against the technical defects of universally applicable beam tube monitoring system at present, such as air suction in the beam tube, line clogging, long sampling time, etc., the paper analyzes the current situation of the spontaneous combustion fire disaster forecast of mine in our country and these defects one by one. On this basis, the paper proposes a research thought that improving the positive pressure beam tube so as to substitute the negative pressure beam tube. Then, the paper introduces the beam tube monitoring system based on positive pressure technology through theoretical analysis and experiment. In the comparison with negative pressure beam tube, the paper concludes the advantage of the new system and draws the conclusion that the positive pressure beam tube is superior to the negative pressure beam tube system both in test result and test time. At last, the paper proposes prospect of the beam tube monitoring system based on positive pressure technology.

Sensing pressure for authentication

NARCIS (Netherlands)

Henderson, N.J.; White, N.M.; Veldhuis, Raymond N.J.; Hartel, Pieter H.; Slump, Cornelis H.

The use of signals resulting from tapping a rhythm on a pressure sensor is explored for authentication. The features used for authentication can be divided into rhythm and waveform features. This paper studies the use of waveform features. A verification scheme based on prototype waveforms is

Wavelength modulation spectroscopy near 5 μm for carbon monoxide sensing in a high-pressure kerosene-fueled liquid rocket combustor

Science.gov (United States)

Lee, Daniel D.; Bendana, Fabio A.; Schumaker, S. Alexander; Spearrin, R. Mitchell

2018-05-01

A laser absorption sensor was developed for carbon monoxide (CO) sensing in high-pressure, fuel-rich combustion gases associated with the internal conditions of hydrocarbon-fueled liquid bipropellant rockets. An absorption feature near 4.98 μm, comprised primarily of two rovibrational lines from the P-branch of the fundamental band, was selected to minimize temperature sensitivity and spectral interference with other combustion gas species at the extreme temperatures (> 3000 K) and pressures (> 50 atm) in the combustion chamber environment. A scanned wavelength modulation spectroscopy technique (1 f-normalized 2 f detection) is utilized to infer species concentration from CO absorption, and mitigate the influence of non-absorption transmission losses and noise associated with the harsh sooting combustor environment. To implement the sensing strategy, a continuous-wave distributed-feedback (DFB) quantum cascade laser (QCL) was coupled to a hollow-core optical fiber for remote mid-infrared light delivery to the test article, with high-bandwidth light detection by a direct-mounted photovoltaic detector. The method was demonstrated to measure time-resolved CO mole fraction over a range of oxidizer-to-fuel ratios and pressures (20-70 atm) in a single-element-injector RP-2-GOx rocket combustor.

Pressurized water reactor systems

International Nuclear Information System (INIS)

Meyer, P.J.

1975-01-01

Design and mode of operation of the main PWR components are described: reactor core, pressure vessel and internals, cooling systems with pumps and steam generators, ancillary systems, and waste processing. (TK) [de

Reports in the area sensor technology: Part 2: Dynamic deviations which may appear via the sensing lines in measurement of reactor pressure and level; Rapporter inom omraadet sensorteknik, Del 2: Dynamiska avvikelser som kan uppstaa via impulsledningarna vid maetning av reaktortryck och nivaa

Energy Technology Data Exchange (ETDEWEB)

Bergdahl, Bengt-Goeran [GSE Power Systems AB, Nykoeping (Sweden)

2002-12-01

The sensors are part of the safety system in a nuclear power plant. They are the first link in a chain of components, which affect the safety system. It is therefore of great importance that the sensors fulfil tough requirements on reliability and response time. In practice, the dynamic qualities of the sensors in a BWR are seldom, or never, tested. The static qualities, on the other hand, are controlled every year when the transmitters are calibrated. This is done during the regular outage of the power plant. It is common that several sensors are connected to the same sensing line. This is true especially in old reactors, where only a few pressure taps are available in the reactor pressure vessel. This is a troublesome disadvantage in the design, since a failure in one sensing line will affect all components, which are connected to that sensing line ('Common Cause Failure'). This report focuses on deviations in the measurement system connected to the sensing lines. The deviations are illustrated by examples from Swedish and foreign BWRs. The sensing lines are mechanically passive components. They can reduce a system's response time even if there are now deviations in the static presentation. This report mentions cases in nuclear power plants, where the time constant of the sensing line has changed from 0.1 seconds, which is a normal response time, to 5 seconds. This has happened because of a gradual blockage of the sensing line. Today, signal analysis is the only way to examine the dynamic qualities of sensing lines. Filtrations can be unveiled by measuring and analysing the transmitter signal, regardless the location of the filtration: in the sensing line, in the transmitter or in other instrumentation components. A practical case is presented where pulsation dampers with so-called needles were used at Ringhals 1 in Sweden. Their influence on the response time for the measurement signal corresponds to a time constant = 0.55 s. By eliminating the

[Invasive arterial blood pressure measurement using an aneroid pressure system in cattle].

Science.gov (United States)

Mosing, M; Franz, S; Iff, I; Schwendenwein, I

2009-06-01

The aim of this study was to compare the results of invasive arterial blood pressure measurement using an electronic pressure transducer (EPT) or an aneroid pressure system (APS) in cattle. A catheter was placed in the auricular artery of 11 adult cattle and connected to a pressure transducer via pressure line. The aneroid system was connected to the same catheter using a three-way stop-cock in the pressure line. On five occasions three consecutive measurements were performed with the APS. The mean blood pressure values of the EPT were recorded before each individual measurement. Values from each device were compared using Passing and Bablok regression of agreement and a Bland and Altman difference plot. One hundred and forty-seven paired measurements were analysed. The average bias between the two methods (EPT vs. APS) was -1.6 mmHg (95 % confidence interval [CI]: -3.0 to -0.2 mmHg). The coefficient of correlation was 1.0084. The aneroid system showed an almost perfect agreement with the EPT. This study shows that it can be used in a clinical setting as well as under field conditions to measure arterial blood pressure in cattle.

Revised National Pressure Ulcer Advisory Panel Pressure Injury Staging System: Revised Pressure Injury Staging System.

Science.gov (United States)

Edsberg, Laura E; Black, Joyce M; Goldberg, Margaret; McNichol, Laurie; Moore, Lynn; Sieggreen, Mary

Our understanding of pressure injury etiology and development has grown in recent years through research, clinical expertise, and global interdisciplinary expert collaboration. Therefore, the National Pressure Ulcer Advisory Panel (NPUAP) has revised the definition and stages of pressure injury. The revision was undertaken to incorporate the current understanding of the etiology of pressure injuries, as well as to clarify the anatomical features present or absent in each stage of injury. An NPUAP-appointed Task Force reviewed the literature and created drafts of definitions, which were then reviewed by stakeholders and the public, including clinicians, educators, and researchers around the world. Using a consensus-building methodology, these revised definitions were the focus of a multidisciplinary consensus conference held in April 2016. As a result of stakeholder and public input, along with the consensus conference, important changes were made and incorporated into the new staging definitions. The revised staging system uses the term injury instead of ulcer and denotes stages using Arabic numerals rather than Roman numerals. The revised definition of a pressure injury now describes the injuries as usually occurring over a bony prominence or under a medical or other device. The revised definition of a Stage 2 pressure injury seeks to clarify the difference between moisture-associated skin damage and injury caused by pressure and/or shear. The term suspected has been removed from the Deep Tissue Pressure Injury diagnostic label. Each definition now describes the extent of tissue loss present and the anatomical features that may or may not be present in the stage of injury. These important revisions reflect the methodical and collaborative approach used to examine the available evidence and incorporate current interdisciplinary clinical expertise into better defining the important phenomenon of pressure injury etiology and development.

Intraocular pressure reduction and regulation system

Science.gov (United States)

Baehr, E. F.; Burnett, J. E.; Felder, S. F.; Mcgannon, W. J.

1979-01-01

An intraocular pressure reduction and regulation system is described and data are presented covering performance in: (1) reducing intraocular pressure to a preselected value, (2) maintaining a set minimum intraocular pressure, and (3) reducing the dynamic increases in intraocular pressure resulting from external loads applied to the eye.

Wireless Capacitive Pressure Sensor With Directional RF Chip Antenna for High Temperature Environments

Science.gov (United States)

Scardelletti, M. C.; Jordan, J. L.; Ponchak, G. E.; Zorman, C. A.

2015-01-01

This paper presents the design, fabrication and characterization of a wireless capacitive pressure sensor with directional RF chip antenna that is envisioned for the health monitoring of aircraft engines operating in harsh environments. The sensing system is characterized from room temperature (25 C) to 300 C for a pressure range from 0 to 100 psi. The wireless pressure system consists of a Clapp-type oscillator design with a capacitive MEMS pressure sensor located in the LC-tank circuit of the oscillator. Therefore, as the pressure of the aircraft engine changes, so does the output resonant frequency of the sensing system. A chip antenna is integrated to transmit the system output to a receive antenna 10 m away.The design frequency of the wireless pressure sensor is 127 MHz and a 2 increase in resonant frequency over the temperature range of 25 to 300 C from 0 to 100 psi is observed. The phase noise is less than minus 30 dBcHz at the 1 kHz offset and decreases to less than minus 80 dBcHz at 10 kHz over the entire temperature range. The RF radiation patterns for two cuts of the wireless system have been measured and show that the system is highly directional and the MEMS pressure sensor is extremely linear from 0 to 100 psi.

Microfluidic pressure sensing using trapped air compression.

Science.gov (United States)

Srivastava, Nimisha; Burns, Mark A

2007-05-01

We have developed a microfluidic method for measuring the fluid pressure head experienced at any location inside a microchannel. The principal component is a microfabricated sealed chamber with a single inlet and no exit; the entrance to the single inlet is positioned at the location where pressure is to be measured. The pressure measurement is then based on monitoring the movement of a liquid-air interface as it compresses air trapped inside the microfabricated sealed chamber and calculating the pressure using the ideal gas law. The method has been used to measure the pressure of the air stream and continuous liquid flow inside microfluidic channels (d approximately 50 microm). Further, a pressure drop has also been measured using multiple microfabricated sealed chambers. For air pressure, a resolution of 700 Pa within a full-scale range of 700-100 kPa was obtained. For liquids, pressure drops as low as 70 Pa were obtained in an operating range from 70 Pa to 10 kPa. Since the method primarily uses a microfluidic sealed chamber, it does not require additional fabrication steps and may easily be incorporated in several lab-on-a-chip fluidic applications for laminar as well as turbulent flow conditions.

LAnd surface remote sensing Products VAlidation System (LAPVAS) and its preliminary application

Science.gov (United States)

Lin, Xingwen; Wen, Jianguang; Tang, Yong; Ma, Mingguo; Dou, Baocheng; Wu, Xiaodan; Meng, Lumin

2014-11-01

The long term record of remote sensing product shows the land surface parameters with spatial and temporal change to support regional and global scientific research widely. Remote sensing product with different sensors and different algorithms is necessary to be validated to ensure the high quality remote sensing product. Investigation about the remote sensing product validation shows that it is a complex processing both the quality of in-situ data requirement and method of precision assessment. A comprehensive validation should be needed with long time series and multiple land surface types. So a system named as land surface remote sensing product is designed in this paper to assess the uncertainty information of the remote sensing products based on a amount of in situ data and the validation techniques. The designed validation system platform consists of three parts: Validation databases Precision analysis subsystem, Inter-external interface of system. These three parts are built by some essential service modules, such as Data-Read service modules, Data-Insert service modules, Data-Associated service modules, Precision-Analysis service modules, Scale-Change service modules and so on. To run the validation system platform, users could order these service modules and choreograph them by the user interactive and then compete the validation tasks of remote sensing products (such as LAI ,ALBEDO ,VI etc.) . Taking SOA-based architecture as the framework of this system. The benefit of this architecture is the good service modules which could be independent of any development environment by standards such as the Web-Service Description Language(WSDL). The standard language: C++ and java will used as the primary programming language to create service modules. One of the key land surface parameter, albedo, is selected as an example of the system application. It is illustrated that the LAPVAS has a good performance to implement the land surface remote sensing product

Design and Evaluation of a Pressure and Temperature Monitoring System for Pressure Ulcer Prevention

Directory of Open Access Journals (Sweden)

Farve Daneshvar Fard

2014-08-01

Full Text Available Introduction Pressure ulcers are tissue damages resulting from blood flow restriction, which occurs when the tissue is exposed to high pressure for a long period of time. These painful sores are common in patients and elderly, who spend extended periods of time in bed or wheelchair. In this study, a continuous pressure and temperature monitoring system was developed for pressure ulcer prevention. Materials and Methods The monitoring system consists of 64 pressure and 64 temperature sensors on a 40×50 cm2 sheet. Pressure and temperature data and the corresponding maps were displayed on a computer in real-time. Risk assessment could be performed by monitoring and recording absolute pressure and temperature values, as well as deviations over time. Furthermore, a posture detection procedure was proposed for sitting posture identification. Information about the patient’s movement history may help caregivers make informed decisions about the patient’s repositioning and ulcer prevention strategies. Results Steady temporal behaviour of the designed system and repeatability of the measurements were evaluated using several particular tests. The results illustrated that the system could be utilized for continuous monitoring of interface pressure and temperature for pressure ulcer prevention. Furthermore, the proposed method for detecting sitting posture was verified using a statistical analysis. Conclusion A continuous time pressure and temperature monitoring system was presented in this study. This system may be suited for pressure ulcer prevention given its feasibility for simultaneous monitoring of pressure and temperature and alarming options. Furthermore, a method for detecting different sitting postures was proposed and verified. Pressure ulcers in wheelchair-bound patients may be prevented using this sitting posture detection method.

On-line pressure measurement using scanning systems

International Nuclear Information System (INIS)

Morss, A.G.; Watson, A.P.

1978-08-01

Data collection methods can be improved significantly by using pressure scanning systems in conjunction with transducers for the measurement of pressure distribution in fluid flow rigs. However, the response of pressure transducers to the slight random pressure fluctuations that occur in practice can cause some measurement problems, especially for accurate work. The nature of these pressure fluctuations is examined and suitable analysis techniques are recommended. Results obtained using these techniques are presented. It is concluded that by using the correct techniques pressure transducer systems can be used to measure pressure distributions accurately and are sufficiently sensitive to measure very small systematic effects with great precision. (author)

3D printed System-on-Package (SoP) for environmental sensing and localization applications

KAUST Repository

Zhen, Su; Bilal, Rana Muhammad; Shamim, Atif

2017-01-01

This paper presents for the first time an innovative 3D printed SoP sensor node with temperature, pressure and humidity sensing capabilities. It has an integrated wireless readout through a near isotropic (900MHz) GSM antenna-on-package. This sensor

Advanced feed-through systems for in-well optical fibre sensing

International Nuclear Information System (INIS)

Shiach, G; Nolan, A; McAvoy, S; McStay, D; Prel, C; Smith, M

2007-01-01

A new optical fibre feed-through for use in subsea in-well optical fibre sensing systems is reported. The new feed-through is compatible for use with standard subsea Christmas Tree penetrators and allows multiple re-mating of the feed-through over the lifetime of the device. The system has been extensively tested under in-well conditions and found to conform to the performance requirements. The new feed-through is planned to be used in one of the first subsea optical fibre in-well sensing systems

The organophosphate malathion disturbs gut microbiome development and the quorum-Sensing system.

Science.gov (United States)

Gao, Bei; Chi, Liang; Tu, Pengcheng; Bian, Xiaoming; Thomas, Jesse; Ru, Hongyu; Lu, Kun

2018-02-01

The gut microbiome has tremendous potential to impact health and disease. Various environmental toxicants, including insecticides, have been shown to alter gut microbiome community structures. However, the mechanism that compositionally and functionally regulates gut microbiota remains unclear. Quorum sensing is known to modulate intra- and interspecies gene expression and coordinate population responses. It is unknown whether quorum sensing is disrupted when environmental toxicants cause perturbations in the gut microbiome community structure. To reveal the response of the quorum-sensing system to environmental exposure, we use a combination of Illumina-based 16S rRNA gene amplicon and shotgun metagenome sequencing to examine the impacts of a widely used organophosphate insecticide, malathion, on the gut microbiome trajectory, quorum sensing system and behaviors related to quorum sensing, such as motility and pathogenicity. Our results demonstrated that malathion perturbed the gut microbiome development, quorum sensing and quorum sensing related behaviors. These findings may provide a novel mechanistic understanding of the role of quorum-sensing in the gut microbiome toxicity of malathion. Copyright © 2017. Published by Elsevier B.V.

Turbine airfoil cooling system with cooling systems using high and low pressure cooling fluids

Science.gov (United States)

Marsh, Jan H.; Messmann, Stephen John; Scribner, Carmen Andrew

2017-10-25

A turbine airfoil cooling system including a low pressure cooling system and a high pressure cooling system for a turbine airfoil of a gas turbine engine is disclosed. In at least one embodiment, the low pressure cooling system may be an ambient air cooling system, and the high pressure cooling system may be a compressor bleed air cooling system. In at least one embodiment, the compressor bleed air cooling system in communication with a high pressure subsystem that may be a snubber cooling system positioned within a snubber. A delivery system including a movable air supply tube may be used to separate the low and high pressure cooling subsystems. The delivery system may enable high pressure cooling air to be passed to the snubber cooling system separate from low pressure cooling fluid supplied by the low pressure cooling system to other portions of the turbine airfoil cooling system.

Pressure dynamic characteristics of pressure controlled ventilation system of a lung simulator.

Science.gov (United States)

Shi, Yan; Ren, Shuai; Cai, Maolin; Xu, Weiqing; Deng, Qiyou

2014-01-01

Mechanical ventilation is an important life support treatment of critically ill patients, and air pressure dynamics of human lung affect ventilation treatment effects. In this paper, in order to obtain the influences of seven key parameters of mechanical ventilation system on the pressure dynamics of human lung, firstly, mechanical ventilation system was considered as a pure pneumatic system, and then its mathematical model was set up. Furthermore, to verify the mathematical model, a prototype mechanical ventilation system of a lung simulator was proposed for experimental study. Last, simulation and experimental studies on the air flow dynamic of the mechanical ventilation system were done, and then the pressure dynamic characteristics of the mechanical system were obtained. The study can be referred to in the pulmonary diagnostics, treatment, and design of various medical devices or diagnostic systems.

Pressure equalization systems in pressurized water reactor fuel rods

International Nuclear Information System (INIS)

Steven, J.; Wunderlich, F.

1979-01-01

For the development of a pressure reduction system in PWR fuel rods the capability of charcoal to adsorb Helium, Xenon and Krypton at temperatures of about 300 0 C was investigated. The influence of the adsorption on fuel rod internal pressure and in creep strain on the tube was evaluated in a design study. (orig.) [de

Evaluation of a continuous-positive pressure generating system

Directory of Open Access Journals (Sweden)

Herrera N

2016-03-01

Full Text Available Nestor Herrera,1,2 Roberto Regnícoli,1,2 Mariel Murad1,2 1Neonatology Unit, Italian Hospital Garibaldi, Rosario, Argentina; 2Experimental Medicine and Surgery Unit, Italian University Institute of Rosario, Argentina Abstract: The use of systems that apply continuous-positive airway pressure by means of noninvasive methods is widespread in the neonatal care practice and has been associated with a decrease in the use of invasive mechanical ventilation, less administration of exogenous surfactant, and bronchopulmonary dysplasia. Few experimental studies on the functioning of the neonatology systems that generate continuous-positive airway pressure have been reported. A flow resistor system associated with an underwater seal resistor in a lung test model was described, and it was compared with an underwater seal threshold resistor system. Important differences in the pressures generated in the different systems studied were verified. The generation of pressure was associated with the immersion depth and the diameter of the bubble tubing. The flow resistor associated with an underwater seal, with small bubble tubing, showed no important differences in the evaluated pressures, exerting a stabilizing effect on the generated pressures. The importance of measuring the pressure generated by the different systems studied was verified, due to the differences between the working pressures set and the pressures measured. Keywords: continuous-positive pressure, flow and threshold resistor, BCPAP

Assessment of fiber optic sensors and other advanced sensing technologies for nuclear power plants

International Nuclear Information System (INIS)

Hashemian, H.M.

1996-01-01

As a result of problems such as calibration drift in nuclear plant pressure sensors and the recent oil loss syndrome in some models of Rosemount pressure transmitters, the nuclear industry has become interested in fiber optic pressure sensors. Fiber optic sensing technologies have been considered for the development of advanced instrumentation and control (I ampersand C) systems for the next generation of reactors and in older plants which are retrofitted with new I ampersand C systems. This paper presents the results of a six-month Phase I study to establish the state-of-the-art in fiber optic pressure sensing. This study involved a literature review, contact with experts in the field, an industrial survey, a site visit to a fiber optic sensor manufacturer, and laboratory testing of a fiber optic pressure sensor. The laboratory work involved both static and dynamic performance tests. This initial Phase I study has recently been granted a two-year extension by the U.S. Nuclear Regulatory Commission (NRC). The next phase will evaluate fiber optic pressure sensors in specific nuclear plant applications in addition to other advanced methods for monitoring critical nuclear plant equipment

Soft Active Materials for Actuation, Sensing, and Electronics

OpenAIRE

Kramer, Rebecca Krone

2012-01-01

Future generations of robots, electronics, and assistive medical devices will include systems that are soft and elastically deformable, allowing them to adapt their morphology in unstructured environments. This will require soft active materials for actuation, circuitry, and sensing of deformation and contact pressure. The emerging field of soft robotics utilizes these soft active materials to mimic the inherent compliance of natural soft-bodied systems. As the elasticity of robot components ...

A Privacy-Preserving Incentive Mechanism for Participatory Sensing Systems

Directory of Open Access Journals (Sweden)

Xiaoguang Niu

2018-01-01

Full Text Available The proliferation of mobile devices has facilitated the prevalence of participatory sensing applications in which participants collect and share information in their environments. The design of a participatory sensing application confronts two challenges: “privacy” and “incentive” which are two conflicting objectives and deserve deeper attention. Inspired by physical currency circulation system, this paper introduces the notion of E-cent, an exchangeable unit bearer currency. Participants can use the E-cent to take part in tasks anonymously. By employing E-cent, we propose an E-cent-based privacy-preserving incentive mechanism, called EPPI. As a dynamic balance regulatory mechanism, EPPI can not only protect the privacy of participant, but also adjust the whole system to the ideal situation, under which the rated tasks can be finished at minimal cost. To the best of our knowledge, EPPI is the first attempt to build an incentive mechanism while maintaining the desired privacy in participatory sensing systems. Extensive simulation and analysis results show that EPPI can achieve high anonymity level and remarkable incentive effects.

Pressure Dynamic Characteristics of Pressure Controlled Ventilation System of a Lung Simulator

Directory of Open Access Journals (Sweden)

Yan Shi

2014-01-01

Full Text Available Mechanical ventilation is an important life support treatment of critically ill patients, and air pressure dynamics of human lung affect ventilation treatment effects. In this paper, in order to obtain the influences of seven key parameters of mechanical ventilation system on the pressure dynamics of human lung, firstly, mechanical ventilation system was considered as a pure pneumatic system, and then its mathematical model was set up. Furthermore, to verify the mathematical model, a prototype mechanical ventilation system of a lung simulator was proposed for experimental study. Last, simulation and experimental studies on the air flow dynamic of the mechanical ventilation system were done, and then the pressure dynamic characteristics of the mechanical system were obtained. The study can be referred to in the pulmonary diagnostics, treatment, and design of various medical devices or diagnostic systems.

Pressure Dynamic Characteristics of Pressure Controlled Ventilation System of a Lung Simulator

Science.gov (United States)

Shi, Yan; Ren, Shuai; Cai, Maolin; Xu, Weiqing; Deng, Qiyou

2014-01-01

Mechanical ventilation is an important life support treatment of critically ill patients, and air pressure dynamics of human lung affect ventilation treatment effects. In this paper, in order to obtain the influences of seven key parameters of mechanical ventilation system on the pressure dynamics of human lung, firstly, mechanical ventilation system was considered as a pure pneumatic system, and then its mathematical model was set up. Furthermore, to verify the mathematical model, a prototype mechanical ventilation system of a lung simulator was proposed for experimental study. Last, simulation and experimental studies on the air flow dynamic of the mechanical ventilation system were done, and then the pressure dynamic characteristics of the mechanical system were obtained. The study can be referred to in the pulmonary diagnostics, treatment, and design of various medical devices or diagnostic systems. PMID:25197318

Pressure regulation system for modern gas-filled detectors

International Nuclear Information System (INIS)

McDonald, R.J.

1986-08-01

A gas pressure and flow regulation system has been designed and constructed to service a wide variety of gas-filled detectors which operate at pressures of ∼2 to 1000 Torr and flow rate of ∼5 to 200 standard cubic centimeters per minute (sccm). Pressure regulation is done at the detector input by a pressure transducer linked to a solenoid leak valve via an electronic control system. Gas flow is controlled via a mechanical leak valve at the detector output. Interchangeable transducers, flowmeters, and leak valves allow for different pressure and flow ranges. The differential pressure transducer and control system provide automatic let-up of vacuum chambers to atmospheric pressure while maintaining a controlled overpressure in the detector. The gas system is constructed on a standard 19'' rack-mounted panel from commercially available parts. Five of these systems have been built and are routinely used for both ionization chambers and position-sensitive avalanche detectors

Implementation of Multiple Host Nodes in Wireless Sensing Node Network System for Landslide Monitoring

International Nuclear Information System (INIS)

Bin Abas, Faizulsalihin; Takayama, Shigeru

2015-01-01

This paper proposes multiple host nodes in Wireless Sensing Node Network System (WSNNS) for landslide monitoring. As landslide disasters damage monitoring system easily, one major demand in landslide monitoring is the flexibility and robustness of the system to evaluate the current situation in the monitored area. For various reasons WSNNS can provide an important contribution to reach that aim. In this system, acceleration sensors and GPS are deployed in sensing nodes. Location information by GPS, enable the system to estimate network topology and enable the system to perceive the location in emergency by monitoring the node mode. Acceleration sensors deployment, capacitate this system to detect slow mass movement that can lead to landslide occurrence. Once deployed, sensing nodes self-organize into an autonomous wireless ad hoc network. The measurement parameter data from sensing nodes is transmitted to Host System via host node and ''Cloud'' System. The implementation of multiple host nodes in Local Sensing Node Network System (LSNNS), improve risk- management of the WSNNS for real-time monitoring of landslide disaster

Implementation of Multiple Host Nodes in Wireless Sensing Node Network System for Landslide Monitoring

Science.gov (United States)

Abas, Faizulsalihin bin; Takayama, Shigeru

2015-02-01

This paper proposes multiple host nodes in Wireless Sensing Node Network System (WSNNS) for landslide monitoring. As landslide disasters damage monitoring system easily, one major demand in landslide monitoring is the flexibility and robustness of the system to evaluate the current situation in the monitored area. For various reasons WSNNS can provide an important contribution to reach that aim. In this system, acceleration sensors and GPS are deployed in sensing nodes. Location information by GPS, enable the system to estimate network topology and enable the system to perceive the location in emergency by monitoring the node mode. Acceleration sensors deployment, capacitate this system to detect slow mass movement that can lead to landslide occurrence. Once deployed, sensing nodes self-organize into an autonomous wireless ad hoc network. The measurement parameter data from sensing nodes is transmitted to Host System via host node and "Cloud" System. The implementation of multiple host nodes in Local Sensing Node Network System (LSNNS), improve risk- management of the WSNNS for real-time monitoring of landslide disaster.

Feedback Regulation of Intracellular Hydrostatic Pressure in Surface Cells of the Lens

Science.gov (United States)

Gao, Junyuan; Sun, Xiurong; White, Thomas W.; Delamere, Nicholas A.; Mathias, Richard T.

2015-01-01

In wild-type lenses from various species, an intracellular hydrostatic pressure gradient goes from ∼340 mmHg in central fiber cells to 0 mmHg in surface cells. This gradient drives a center-to-surface flow of intracellular fluid. In lenses in which gap-junction coupling is increased, the central pressure is lower, whereas if gap-junction coupling is reduced, the central pressure is higher but surface pressure is always zero. Recently, we found that surface cell pressure was elevated in PTEN null lenses. This suggested disruption of a feedback control system that normally maintained zero surface cell pressure. Our purpose in this study was to investigate and characterize this feedback control system. We measured intracellular hydrostatic pressures in mouse lenses using a microelectrode/manometer-based system. We found that all feedback went through transport by the Na/K ATPase, which adjusted surface cell osmolarity such that pressure was maintained at zero. We traced the regulation of Na/K ATPase activity back to either TRPV4, which sensed positive pressure and stimulated activity, or TRPV1, which sensed negative pressure and inhibited activity. The inhibitory effect of TRPV1 on Na/K pumps was shown to signal through activation of the PI3K/AKT axis. The stimulatory effect of TRPV4 was shown in previous studies to go through a different signal transduction path. Thus, there is a local two-legged feedback control system for pressure in lens surface cells. The surface pressure provides a pedestal on which the pressure gradient sits, so surface pressure determines the absolute value of pressure at each radial location. We speculate that the absolute value of intracellular pressure may set the radial gradient in the refractive index, which is essential for visual acuity. PMID:26536260

Real-time reactor coolant system pressure/temperature limit system

International Nuclear Information System (INIS)

Newton, D.G.; Schemmel, R.R.; Van Scooter, W.E. Jr.

1991-01-01

This patent describes an system, used in controlling the operating of a nuclear reactor coolant system, which automatically calculates and displays allowable reactor coolant system pressure/temperature limits within the nuclear reactor coolant system based upon real-time inputs. It comprises: means for producing signals representative of real-time operating parameters of the nuclear reactor cooling system; means for developing pressure and temperature limits relating the real-time operating parameters of the nuclear reactor coolant system, for normal and emergency operation thereof; means for processing the signals representative of real-time operating parameters of the nuclear reactor coolant system to perform calculations of a best estimate of signals, check manual inputs against permissible valves and test data acquisition hardware for validity and over/under range; and means for comparing the representative signals with limits for the real-time operating parameters to produce a signal for a real-time display of the pressure and temperature limits and of the real-time operating parameters use an operator in controlling the operation of the nuclear reactor coolant system

Global versus local mechanisms of temperature sensing in ion channels.

Science.gov (United States)

Arrigoni, Cristina; Minor, Daniel L

2018-05-01

Ion channels turn diverse types of inputs, ranging from neurotransmitters to physical forces, into electrical signals. Channel responses to ligands generally rely on binding to discrete sensor domains that are coupled to the portion of the channel responsible for ion permeation. By contrast, sensing physical cues such as voltage, pressure, and temperature arises from more varied mechanisms. Voltage is commonly sensed by a local, domain-based strategy, whereas the predominant paradigm for pressure sensing employs a global response in channel structure to membrane tension changes. Temperature sensing has been the most challenging response to understand and whether discrete sensor domains exist for pressure and temperature has been the subject of much investigation and debate. Recent exciting advances have uncovered discrete sensor modules for pressure and temperature in force-sensitive and thermal-sensitive ion channels, respectively. In particular, characterization of bacterial voltage-gated sodium channel (BacNa V ) thermal responses has identified a coiled-coil thermosensor that controls channel function through a temperature-dependent unfolding event. This coiled-coil thermosensor blueprint recurs in other temperature sensitive ion channels and thermosensitive proteins. Together with the identification of ion channel pressure sensing domains, these examples demonstrate that "local" domain-based solutions for sensing force and temperature exist and highlight the diversity of both global and local strategies that channels use to sense physical inputs. The modular nature of these newly discovered physical signal sensors provides opportunities to engineer novel pressure-sensitive and thermosensitive proteins and raises new questions about how such modular sensors may have evolved and empowered ion channel pores with new sensibilities.

Remote control of Alfven eigenmode sensing system on the large helical device

International Nuclear Information System (INIS)

Ito, T.; Toi, K.; Matsunaga, G.

2008-01-01

An active sensing system of Alfven eigenmodes (AEs), which consists of a set of toroidally distributed loop antennas and several bi-polar power supplies, has been developed in the large helical device (LHD). The power supplies are controlled with a function generator receiving a control pattern of antenna current and the driving frequency from a personal computer (PC) in an LHD control room. This sensing method is based on the analysis of the frequency dependence of a transfer function that is derived by the ratio of the Fourier-transformed magnetic probe signal ('plasma response') to antenna current one ('exciter signal'). Typically, the driving frequency of the antenna current is swept linearly in time from 10 kHz to 500 kHz for 2 s in the LHD experiment. The sensing system is fully controlled through Ethernet LAN with easy extendable GUI. Configuration and control scheme of the active sensing system of AEs are presented in this paper. An initial result of the system operation is also described

Liquid crystalline fiber optic colorimeter for hydrostatic pressure measurement

Science.gov (United States)

Wolinski, Tomasz R.; Bajdecki, Waldemar K.; Domanski, Andrzej W.; Karpierz, Miroslaw A.; Konopka, Witold; Nasilowski, T.; Sierakowski, Marek W.; Swillo, Marcin; Dabrowski, Roman S.; Nowinowski-Kruszelnicki, Edward; Wasowski, Janusz

2001-08-01

This paper presents results of tests performed on a fiber optic system of liquid crystalline transducer for hydrostatic pressure monitoring based on properties of colorimetry. The system employs pressure-induced deformations occurring in liquid crystalline (LC) cells configured in a homogeneous Frederiks geometry. The sensor is compared of a round LC cell placed inside a specially designed pressure chamber. As a light source we used a typical diode operating at red wavelength and modulated using standard techniques. The pressure transducer was connected to a computer with a specially designed interface built on the bas of advanced ADAM modules. Results indicate that the system offers high response to pressure with reduced temperature sensitivity and, depending on the LC cell used, can be adjusted for monitoring of low hydrostatic pressures up to 6 MPa. These studies have demonstrated the feasibility of fiber optic liquid crystal colorimeter for hydrostatic pressure sensing specially dedicated to pipe- lines, mining instrumentation, and process-control technologies.

Dynamic pressure sensor calibration techniques offering expanded bandwidth with increased resolution

Science.gov (United States)

Wisniewiski, David

2015-03-01

Advancements in the aerospace, defense and energy markets are being made possible by increasingly more sophisticated systems and sub-systems which rely upon critical information to be conveyed from the physical environment being monitored through ever more specialized, extreme environment sensing components. One sensing parameter of particular interest is dynamic pressure measurement. Crossing the boundary of all three markets (i.e. aerospace, defense and energy) is dynamic pressure sensing which is used in research and development of gas turbine technology, and subsequently embedded into a control loop used for long-term monitoring. Applications include quantifying the effects of aircraft boundary layer ingestion into the engine inlet to provide a reliable and robust design. Another application includes optimization of combustor dynamics by "listening" to the acoustic signature so that fuel-to-air mixture can be adjusted in real-time to provide cost operating efficiencies and reduced NOx emissions. With the vast majority of pressure sensors supplied today being calibrated either statically or "quasi" statically, the dynamic response characterization of the frequency dependent sensitivity (i.e. transfer function) of the pressure sensor is noticeably absent. The shock tube has been shown to be an efficient vehicle to provide frequency response of pressure sensors from extremely high frequencies down to 500 Hz. Recent development activity has lowered this starting frequency; thereby augmenting the calibration bandwidth with increased frequency resolution so that as the pressure sensor is used in an actual test application, more understanding of the physical measurement can be ascertained by the end-user.

Context Sensing System Analysis for Privacy Preservation Based on Game Theory.

Science.gov (United States)

Wang, Shengling; Li, Luyun; Sun, Weiman; Guo, Junqi; Bie, Rongfang; Lin, Kai

2017-02-10

In a context sensing system in which a sensor-equipped mobile phone runs an unreliable context-aware application, the application can infer the user's contexts, based on which it provides personalized services. However, the application may sell the user's contexts to some malicious adversaries to earn extra profits, which will hinder its widespread use. In the real world, the actions of the user, the application and the adversary in the context sensing system affect each other, so that their payoffs are constrained mutually. To figure out under which conditions they behave well (the user releases, the application does not leak and the adversary does not retrieve the context), we take advantage of game theory to analyze the context sensing system. We use the extensive form game and the repeated game, respectively, to analyze two typical scenarios, single interaction and multiple interaction among three players, from which Nash equilibriums and cooperation conditions are obtained. Our results show that the reputation mechanism for the context-sensing system in the former scenario is crucial to privacy preservation, so is the extent to which the participants are concerned about future payoffs in the latter one.

Unmanned aerial systems for photogrammetry and remote sensing: A review

OpenAIRE

Colomina, Ismael; Molina, Pere

2014-01-01

We discuss the evolution and state-of-the-art of the use of Unmanned Aerial Systems (UAS) in the field of Photogrammetry and Remote Sensing (PaRS). UAS, Remotely-Piloted Aerial Systems, Unmanned Aerial Vehicles or simply, drones are a hot topic comprising a diverse array of aspects including technology, privacy rights, safety and regulations, and even war and peace. Modern photogrammetry and remote sensing identified the potential of UAS-sourced imagery more than thirty years ago. In the last...

Nitrogen pressure in a vacuum system

International Nuclear Information System (INIS)

Edwards, D. Jr.

1977-01-01

Since the N 2 outgassing rate from walls of a vacuum system is generally recognized to be very small, the presence of a N 2 pressure in the system is a useful indication of the presence of real leaks to the atmosphere. A technique of thermal desorption mass spectrometry is introduced which allows the N 2 pressure in the background gas of a baked system to be separated from a CH 4 background to a minimum level of N 2 detectability of approximately 1 percent of the CO background pressure. In typical baked systems (of which an example is given), it is possible to readily determine the sum of all real N 2 leaks to atmosphere at a level of approximately 10 -11 Torr liter/s. This feature makes the technique ideally suited to large complex systems since the leak rate can be evaluated before detailed leak finding procedures are initiated

BOU: Development of a low-cost tethered balloon sensing system for monitoring the lower atmosphere

Science.gov (United States)

Picos, Rodrigo; Lopez-Grifol, Alvaro; Martinez-Villagrassa, Daniel; Simó, Gemma; Wenger, Burkhard; Dünnermann, Jens; Jiménez, Maria Antonia; Cuxart, Joan

2016-04-01

The study of the atmospheric boundary layer, the lowest part of the atmosphere, and the processes that occur therein often requires the observation of vertical profiles of the main meteorological variables, i.e. air temperature and humidity, wind vector and barometric pressure. In particular, when the interest is focused on the air-surface interactions, a high vertical resolution over the first 500 m is required for the observations to describe the physical processes that occur immediately above the surface. Typically, these needs are covered with the use of captive balloons, which are helium-filled balloons tethered to a winch on the ground and a sensor package suspended a short distance below the balloon. Since the commercial version of such instrumental platforms are scarce and expensive, a new low-cost device has been developed in the last years: BOU (tethered Balloon sonde OWL-UIB). In this paper, we focus on the sensor package and data acquisition system part, that is able to fulfill the low-cost requirements. The system uses a low-cost Arduino Mega board as the processor, and stores all the data in a SD card, though an RF connection is also possible but more unreliable. The system has been configured to sample temperature, humidity, air pressure, wind speed, having also a magnetometer and an accelerometer. Sampling time was 1 second, though it was possible to set it faster. It is worth mentioning that the system is easily reconfigurable, and more sensors can be added. The system is powered by a Polymer battery of 1800mA , allowing the system to run continously for more than 6 hours. The temperature is acquired using three different sensors (a HYT 271 calibrated sensor with an accuracy of ±0.2 °C, plus the internal temperature sensors of the wind and pressure sensors, with accuracies around ±0.5 °C). The humidity is also sensed using the calibrated HYT 271 sensor, which features an accuracy of ±1.8%. Air pressure is sensed using a BMP080 sensor, which

Chronically implanted pressure sensors: challenges and state of the field.

Science.gov (United States)

Yu, Lawrence; Kim, Brian J; Meng, Ellis

2014-10-31

Several conditions and diseases are linked to the elevation or depression of internal pressures from a healthy, normal range, motivating the need for chronic implantable pressure sensors. A simple implantable pressure transduction system consists of a pressure-sensing element with a method to transmit the data to an external unit. The biological environment presents a host of engineering issues that must be considered for long term monitoring. Therefore, the design of such systems must carefully consider interactions between the implanted system and the body, including biocompatibility, surgical placement, and patient comfort. Here we review research developments on implantable sensors for chronic pressure monitoring within the body, focusing on general design requirements for implantable pressure sensors as well as specifications for different medical applications. We also discuss recent efforts to address biocompatibility, efficient telemetry, and drift management, and explore emerging trends.

Social sensing building reliable systems on unreliable data

CERN Document Server

Wang, Dong; Kaplan, Lance

2015-01-01

Increasingly, human beings are sensors engaging directly with the mobile Internet. Individuals can now share real-time experiences at an unprecedented scale. Social Sensing: Building Reliable Systems on Unreliable Data looks at recent advances in the emerging field of social sensing, emphasizing the key problem faced by application designers: how to extract reliable information from data collected from largely unknown and possibly unreliable sources. The book explains how a myriad of societal applications can be derived from this massive amount of data collected and shared by average individu

Pressurized subsampling system for pressured gas-hydrate-bearing sediment: Microscale imaging using X-ray computed tomography

International Nuclear Information System (INIS)

Jin, Yusuke; Konno, Yoshihiro; Nagao, Jiro

2014-01-01

A pressurized subsampling system was developed for pressured gas hydrate (GH)-bearing sediments, which have been stored under pressure. The system subsamples small amounts of GH sediments from cores (approximately 50 mm in diameter and 300 mm in height) without pressure release to atmospheric conditions. The maximum size of the subsamples is 12.5 mm in diameter and 20 mm in height. Moreover, our system transfers the subsample into a pressure vessel, and seals the pressure vessel by screwing in a plug under hydraulic pressure conditions. In this study, we demonstrated pressurized subsampling from artificial xenon-hydrate sediments and nondestructive microscale imaging of the subsample, using a microfocus X-ray computed tomography (CT) system. In addition, we estimated porosity and hydrate saturation from two-dimensional X-ray CT images of the subsamples

Intelligent Balanced Device and its Sensing System for Beam Pumping Units

Directory of Open Access Journals (Sweden)

Hangxin WEI

2014-11-01

Full Text Available In order to save the energy of the beam pumping unit, the intelligent balanced device was developed. The device can adjust the position of the balanced-block automatically by the single chip microcomputer controller, and the fuzzy PD control algorithm was used to control the servo motor of the device. Since some signals should be inputted into the intelligent balanced device to calculate the balanced index of the pumping unit, the signals sensing system were designed. The sensing system includes the electric current sensor and voltage sensor of the main motor, the displacement sensor and the force sensor of the horse head. The sensing network has three layers: slave station, relay station and master station. The data transmission between them is based on ZigBee and GPRS method which can adapt the environment of the oil field. The results of application show that the intelligent balanced device and its sensing system can have the effect of reducing the power consumption, working reliability and communication efficiently.

Reducing pressure oscillations in discrete fluid power systems

DEFF Research Database (Denmark)

Hansen, Anders Hedegaard; Pedersen, Henrik Clemmensen

2016-01-01

Discrete fluid power systems featuring transmission lines inherently include pressure oscillations. Experimental verification of a discrete fluid power power take off system for wave energy converters has shown the cylinder pressure to oscillate as force shifts are performed. This article investi...... investigates how cylinder pressure oscillations may be reduced by shaping the valve opening trajectory without the need for closed loop pressure feedback. Furthermore the energy costs of reducing pressure oscillations are investigated....

Virtual sensors for active noise control in acoustic-structural coupled enclosures using structural sensing: robust virtual sensor design.

Science.gov (United States)

Halim, Dunant; Cheng, Li; Su, Zhongqing

2011-03-01

The work was aimed to develop a robust virtual sensing design methodology for sensing and active control applications of vibro-acoustic systems. The proposed virtual sensor was designed to estimate a broadband acoustic interior sound pressure using structural sensors, with robustness against certain dynamic uncertainties occurring in an acoustic-structural coupled enclosure. A convex combination of Kalman sub-filters was used during the design, accommodating different sets of perturbed dynamic model of the vibro-acoustic enclosure. A minimax optimization problem was set up to determine an optimal convex combination of Kalman sub-filters, ensuring an optimal worst-case virtual sensing performance. The virtual sensing and active noise control performance was numerically investigated on a rectangular panel-cavity system. It was demonstrated that the proposed virtual sensor could accurately estimate the interior sound pressure, particularly the one dominated by cavity-controlled modes, by using a structural sensor. With such a virtual sensing technique, effective active noise control performance was also obtained even for the worst-case dynamics. © 2011 Acoustical Society of America

Computerized reactor pressure vessel materials information system

International Nuclear Information System (INIS)

Strosnider, J.; Monserrate, C.; Kenworthy, L.D.; Tether, C.D.

1980-10-01

A computerized information system for storage and retrieval of reactor pressure vessel materials data was established, as part of Task Action Plan A-11, Reactor Vessel Materials Toughness. Data stored in the system are necessary for evaluating the resistance of reactor pressure vessels to flaw-induced fracture. This report includes (1) a description of the information system; (2) guidance on accessing the system; and (3) a user's manual for the system

Actively Perceiving and Responsive Soft Robots Enabled by Self-Powered, Highly Extensible, and Highly Sensitive Triboelectric Proximity- and Pressure-Sensing Skins.

Science.gov (United States)

Lai, Ying-Chih; Deng, Jianan; Liu, Ruiyuan; Hsiao, Yung-Chi; Zhang, Steven L; Peng, Wenbo; Wu, Hsing-Mei; Wang, Xingfu; Wang, Zhong Lin

2018-06-04

Robots that can move, feel, and respond like organisms will bring revolutionary impact to today's technologies. Soft robots with organism-like adaptive bodies have shown great potential in vast robot-human and robot-environment applications. Developing skin-like sensory devices allows them to naturally sense and interact with environment. Also, it would be better if the capabilities to feel can be active, like real skin. However, challenges in the complicated structures, incompatible moduli, poor stretchability and sensitivity, large driving voltage, and power dissipation hinder applicability of conventional technologies. Here, various actively perceivable and responsive soft robots are enabled by self-powered active triboelectric robotic skins (tribo-skins) that simultaneously possess excellent stretchability and excellent sensitivity in the low-pressure regime. The tribo-skins can actively sense proximity, contact, and pressure to external stimuli via self-generating electricity. The driving energy comes from a natural triboelectrification effect involving the cooperation of contact electrification and electrostatic induction. The perfect integration of the tribo-skins and soft actuators enables soft robots to perform various actively sensing and interactive tasks including actively perceiving their muscle motions, working states, textile's dampness, and even subtle human physiological signals. Moreover, the self-generating signals can drive optoelectronic devices for visual communication and be processed for diverse sophisticated uses. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

46 CFR 154.801 - Pressure relief systems.

Science.gov (United States)

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Pressure relief systems. 154.801 Section 154.801 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY... Vent Systems § 154.801 Pressure relief systems. (a) Each cargo tank that has a volume of 20m3 (706 ft.3...

Dynamic Sensing of Cornea Deformation during an Air Puff

Science.gov (United States)

Yamada, Kenji; Yamasaki, Naoyuki; Gosho, Takumi; Kiuchi, Yoshiaki; Takenaka, Jouji; Higashimori, Mitsuru; Kaneko, Makoto

In early diagnosis of glancoma, intraocular pressure measurement is one of an important method. Non-contact method has measured eye pressure through the deformation of cornea during the increase of the force due to air puff. The deformation is influenced by the cornea stiffness as well as the eye internal pressure. Since the cornea stiffness is unknown in general, it is difficult to evaluate the ture eye pressure. The dynamic behavior of cornea under air puff may provide us with a good hint for evaluating the cornea stiffness appropriately. For this purpose, we develop the sensing system composed of a high speed camera, a mirror for producing a virtual camera, a non-contact tonometer and a slit light source. This system enables us to measure the cornea deformation under concave shape. We show the experimental data for human eyes as well as an artificial eye made by transparent material.

Remote control of Alfven eigenmode sensing system on the large helical device

Energy Technology Data Exchange (ETDEWEB)

Ito, T. [Nagoya University, Department of Energy Engineering and Science, Furo-cho, Chikusa-ku, Nagoya City, Aichi (Japan)], E-mail: ito.takafumi@lhd.nifs.ac.jp; Toi, K. [Nagoya University, Department of Energy Engineering and Science, Furo-cho, Chikusa-ku, Nagoya City, Aichi (Japan); National Institute for Fusion Science, 322-6 Oroshicho, Toki, Gifu (Japan); Matsunaga, G. [Japan Atomic Energy Agency, 801-1 Mukouyama, Naka, Ibaraki 311-0193 (Japan)

2008-04-15

An active sensing system of Alfven eigenmodes (AEs), which consists of a set of toroidally distributed loop antennas and several bi-polar power supplies, has been developed in the large helical device (LHD). The power supplies are controlled with a function generator receiving a control pattern of antenna current and the driving frequency from a personal computer (PC) in an LHD control room. This sensing method is based on the analysis of the frequency dependence of a transfer function that is derived by the ratio of the Fourier-transformed magnetic probe signal ('plasma response') to antenna current one ('exciter signal'). Typically, the driving frequency of the antenna current is swept linearly in time from 10 kHz to 500 kHz for 2 s in the LHD experiment. The sensing system is fully controlled through Ethernet LAN with easy extendable GUI. Configuration and control scheme of the active sensing system of AEs are presented in this paper. An initial result of the system operation is also described.

Practical Approach To Building A Mid-Wave Remote Sensing System

Energy Technology Data Exchange (ETDEWEB)

Pyke, Benjamin J. [Univ. of Arizona, Tucson, AZ (United States)

2017-01-01

The purpose of this project, Laser Active Transmitter & Receiver (LATR), was to build a mobile ground based remote sensing system that can detect, identify and quantify a specific gaseous species using Differential Absorption LIDAR (DIAL). This thesis project is concerned with the development and field testing of a mid-wave infrared active remote sensing system, capable of identifying and quantifying emissions in the 3.2 – 3.5 micron range. The goal is to give a brief description of what remote sensing is about and the specific technique used to analyze the collected data. The thesis will discuss the transmitter and the associated subsystems used to create the required wavelength, and the receiver used to collect the returns. And finally, the thesis will discuss the process of collecting the data and some of the results from field and lab collections.

Sapphire-fiber-based distributed high-temperature sensing system.

Science.gov (United States)

Liu, Bo; Yu, Zhihao; Hill, Cary; Cheng, Yujie; Homa, Daniel; Pickrell, Gary; Wang, Anbo

2016-09-15

We present, for the first time to our knowledge, a sapphire-fiber-based distributed high-temperature sensing system based on a Raman distributed sensing technique. High peak power laser pulses at 532 nm were coupled into the sapphire fiber to generate the Raman signal. The returned Raman Stokes and anti-Stokes signals were measured in the time domain to determine the temperature distribution along the fiber. The sensor was demonstrated from room temperature up to 1200°C in which the average standard deviation is about 3.7°C and a spatial resolution of about 14 cm was achieved.

Dynamic tire pressure sensor for measuring ground vibration.

Science.gov (United States)

Wang, Qi; McDaniel, James Gregory; Wang, Ming L

2012-11-07

This work presents a convenient and non-contact acoustic sensing approach for measuring ground vibration. This approach, which uses an instantaneous dynamic tire pressure sensor (DTPS), possesses the capability to replace the accelerometer or directional microphone currently being used for inspecting pavement conditions. By measuring dynamic pressure changes inside the tire, ground vibration can be amplified and isolated from environmental noise. In this work, verifications of the DTPS concept of sensing inside the tire have been carried out. In addition, comparisons between a DTPS, ground-mounted accelerometer, and directional microphone are made. A data analysis algorithm has been developed and optimized to reconstruct ground acceleration from DTPS data. Numerical and experimental studies of this DTPS reveal a strong potential for measuring ground vibration caused by a moving vehicle. A calibration of transfer function between dynamic tire pressure change and ground acceleration may be needed for different tire system or for more accurate application.

An eHealth System for Pressure Ulcer Risk Assessment Based on Accelerometer and Pressure Data

Directory of Open Access Journals (Sweden)

Dieter Hayn

2015-01-01

Full Text Available Pressure ulcers are a common skin disease which is associated with pain, reduced autonomy, social isolation, and reduced quality of life. There are several systems for monitoring of pressure ulcer-related risk factors on the market, but up to now no satisfactory solution is available, especially for people with medium pressure ulcer risk. We present a novel pressure ulcer risk assessment and prevention system, which combines the advantages of accelerometer and pressure sensors for monitoring pressure ulcer risk factors. Sensors are used for detection of repositionings of the person lying on the mattress. Sensor data are sent to a tablet where they are analysed and presented graphically. The system was evaluated in a long-term test at the homes of people of the target group. Results indicate that the system is able to detect movements of persons while lying in bed. Weak correlation in between mobility and Braden pressure ulcer risk was found (correlation factor = 0.31. From our data, long-term trends could be visualized as well as 24 h mobility profiles. Such graphical illustrations might be helpful for caregivers in order to optimize care of people with medium to high pressure ulcer risk.

Analyzing Fourier Transforms for NASA DFRC's Fiber Optic Strain Sensing System

Science.gov (United States)

Fiechtner, Kaitlyn Leann

2010-01-01

This document provides a basic overview of the fiber optic technology used for sensing stress, strain, and temperature. Also, the document summarizes the research concerning speed and accuracy of the possible mathematical algorithms that can be used for NASA DFRC's Fiber Optic Strain Sensing (FOSS) system.

Multilayered gold/silica nanoparticulate bilayer devices using layer-by-layer self organisation for flexible bending and pressure sensing applications

Energy Technology Data Exchange (ETDEWEB)

Shah Alam, Md. [Department of Electrical and Electronic Engineering, Rajshahi University of Engineering and Technology, Rajshahi 6204 (Bangladesh); Center of Excellence in Nanotechnology, Asian Institute of Technology, 12120 Pathumthani (Thailand); Mohammed, Waleed S., E-mail: waleed.m@bu.ac.th [Center of Research in Optoelectronics, Communication and Control System (BU-CROCCS), School of Engineering, Bangkok University, Pathumthani 12120 (Thailand); Dutta, Joydeep, E-mail: dutta@squ.edu.om [Center of Excellence in Nanotechnology, Asian Institute of Technology, 12120 Pathumthani (Thailand); Chair in Nanotechnology, Water Research Center, Sultan Qaboos University, P.O. Box 33, Al Khoud 123 (Oman)

2014-02-17

A pressure and bending sensor was fabricated using multilayer thin films fabricated on a flexible substrate based on layer-by-layer self-organization of 18 nm gold nanoparticles separated by a dielectric layer of 30 nm silica nanoparticles. 50, 75, and 100 gold-silica bi-layered films were deposited and the device characteristics were studied. A threshold voltage was required for electron conduction which increases from 2.4 V for 50 bi-layers to 3.3 V for 100 bi-layers. Upon bending of the device up to about 52°, the threshold voltage and slope of the I-V curves change linearly. Electrical characterization of the multilayer films was carried out under ambient conditions with different pressures and bending angles in the direct current mode. This study demonstrates that the developed multilayer thin films can be used as pressure as well as bending sensing applications.

Advanced 3D Sensing and Visualization System for Unattended Monitoring

Energy Technology Data Exchange (ETDEWEB)

Carlson, J.J.; Little, C.Q.; Nelson, C.L.

1999-01-01

The purpose of this project was to create a reliable, 3D sensing and visualization system for unattended monitoring. The system provides benefits for several of Sandia's initiatives including nonproliferation, treaty verification, national security and critical infrastructure surety. The robust qualities of the system make it suitable for both interior and exterior monitoring applications. The 3D sensing system combines two existing sensor technologies in a new way to continuously maintain accurate 3D models of both static and dynamic components of monitored areas (e.g., portions of buildings, roads, and secured perimeters in addition to real-time estimates of the shape, location, and motion of humans and moving objects). A key strength of this system is the ability to monitor simultaneous activities on a continuous basis, such as several humans working independently within a controlled workspace, while also detecting unauthorized entry into the workspace. Data from the sensing system is used to identi~ activities or conditions that can signi~ potential surety (safety, security, and reliability) threats. The system could alert a security operator of potential threats or could be used to cue other detection, inspection or warning systems. An interactive, Web-based, 3D visualization capability was also developed using the Virtual Reality Modeling Language (VRML). The intex%ace allows remote, interactive inspection of a monitored area (via the Internet or Satellite Links) using a 3D computer model of the area that is rendered from actual sensor data.

Welding wire pressure sensor assembly

Science.gov (United States)

Morris, Timothy B. (Inventor); Milly, Peter F., Sr. (Inventor); White, J. Kevin (Inventor)

1994-01-01

The present invention relates to a device which is used to monitor the position of a filler wire relative to a base material being welded as the filler wire is added to a welding pool. The device is applicable to automated welding systems wherein nonconsumable electrode arc welding processes are utilized in conjunction with a filler wire which is added to a weld pool created by the electrode arc. The invention senses pressure deviations from a predetermined pressure between the filler wire and the base material, and provides electrical signals responsive to the deviations for actuating control mechanisms in an automatic welding apparatus so as to minimize the pressure deviation and to prevent disengagement of the contact between the filler wire and the base material.

A method enabling simultaneous pressure and temperature measurement using a single piezoresistive MEMS pressure sensor

International Nuclear Information System (INIS)

Frantlović, Miloš; Stanković, Srđan; Jokić, Ivana; Lazić, Žarko; Smiljanić, Milče; Obradov, Marko; Vukelić, Branko; Jakšić, Zoran

2016-01-01

In this paper we present a high-performance, simple and low-cost method for simultaneous measurement of pressure and temperature using a single piezoresistive MEMS pressure sensor. The proposed measurement method utilizes the parasitic temperature sensitivity of the sensing element for both pressure measurement correction and temperature measurement. A parametric mathematical model of the sensor was established and its parameters were calculated using the obtained characterization data. Based on the model, a real-time sensor correction for both pressure and temperature measurements was implemented in a target measurement system. The proposed method was verified experimentally on a group of typical industrial-grade piezoresistive sensors. The obtained results indicate that the method enables the pressure measurement performance to exceed that of typical digital industrial pressure transmitters, achieving at the same time the temperature measurement performance comparable to industrial-grade platinum resistance temperature sensors. The presented work is directly applicable in industrial instrumentation, where it can add temperature measurement capability to the existing pressure measurement instruments, requiring little or no additional hardware, and without adverse effects on pressure measurement performance. (paper)

Unmanned aerial systems for photogrammetry and remote sensing: A review

Science.gov (United States)

Colomina, I.; Molina, P.

2014-06-01

We discuss the evolution and state-of-the-art of the use of Unmanned Aerial Systems (UAS) in the field of Photogrammetry and Remote Sensing (PaRS). UAS, Remotely-Piloted Aerial Systems, Unmanned Aerial Vehicles or simply, drones are a hot topic comprising a diverse array of aspects including technology, privacy rights, safety and regulations, and even war and peace. Modern photogrammetry and remote sensing identified the potential of UAS-sourced imagery more than thirty years ago. In the last five years, these two sister disciplines have developed technology and methods that challenge the current aeronautical regulatory framework and their own traditional acquisition and processing methods. Navety and ingenuity have combined off-the-shelf, low-cost equipment with sophisticated computer vision, robotics and geomatic engineering. The results are cm-level resolution and accuracy products that can be generated even with cameras costing a few-hundred euros. In this review article, following a brief historic background and regulatory status analysis, we review the recent unmanned aircraft, sensing, navigation, orientation and general data processing developments for UAS photogrammetry and remote sensing with emphasis on the nano-micro-mini UAS segment.

Wireless, Ultra-Low-Power Implantable Sensor for Chronic Bladder Pressure Monitoring.

Science.gov (United States)

Majerus, Steve J A; Garverick, Steven L; Suster, Michael A; Fletter, Paul C; Damaser, Margot S

2012-06-01

The wireless implantable/intracavity micromanometer (WIMM) system was designed to fulfill the unmet need for a chronic bladder pressure sensing device in urological fields such as urodynamics for diagnosis and neuromodulation for bladder control. Neuromodulation in particular would benefit from a wireless bladder pressure sensor which could provide real-time pressure feedback to an implanted stimulator, resulting in greater bladder capacity while using less power. The WIMM uses custom integrated circuitry, a MEMS transducer, and a wireless antenna to transmit pressure telemetry at a rate of 10 Hz. Aggressive power management techniques yield an average current draw of 9 μ A from a 3.6-Volt micro-battery, which minimizes the implant size. Automatic pressure offset cancellation circuits maximize the sensing dynamic range to account for drifting pressure offset due to environmental factors, and a custom telemetry protocol allows transmission with minimum overhead. Wireless operation of the WIMM has demonstrated that the external receiver can receive the telemetry packets, and the low power consumption allows for at least 24 hours of operation with a 4-hour wireless recharge session.

Sense, decide, act, communicate (SDAC): next generation of smart sensor systems

Science.gov (United States)

Berry, Nina; Davis, Jesse; Ko, Teresa H.; Kyker, Ron; Pate, Ron; Stark, Doug; Stinnett, Regan; Baker, James; Cushner, Adam; Van Dyke, Colin; Kyckelhahn, Brian

2004-09-01

The recent war on terrorism and increased urban warfare has been a major catalysis for increased interest in the development of disposable unattended wireless ground sensors. While the application of these sensors to hostile domains has been generally governed by specific tasks, this research explores a unique paradigm capitalizing on the fundamental functionality related to sensor systems. This functionality includes a sensors ability to Sense - multi-modal sensing of environmental events, Decide - smart analysis of sensor data, Act - response to environmental events, and Communication - internal to system and external to humans (SDAC). The main concept behind SDAC sensor systems is to integrate the hardware, software, and networking to generate 'knowledge and not just data'. This research explores the usage of wireless SDAC units to collectively make up a sensor system capable of persistent, adaptive, and autonomous behavior. These systems are base on the evaluation of scenarios and existing systems covering various domains. This paper presents a promising view of sensor network characteristics, which will eventually yield smart (intelligent collectives) network arrays of SDAC sensing units generally applicable to multiple related domains. This paper will also discuss and evaluate the demonstration system developed to test the concepts related to SDAC systems.

High-Temperature Piezoelectric Sensing

Directory of Open Access Journals (Sweden)

Xiaoning Jiang

2013-12-01

Full Text Available Piezoelectric sensing is of increasing interest for high-temperature applications in aerospace, automotive, power plants and material processing due to its low cost, compact sensor size and simple signal conditioning, in comparison with other high-temperature sensing techniques. This paper presented an overview of high-temperature piezoelectric sensing techniques. Firstly, different types of high-temperature piezoelectric single crystals, electrode materials, and their pros and cons are discussed. Secondly, recent work on high-temperature piezoelectric sensors including accelerometer, surface acoustic wave sensor, ultrasound transducer, acoustic emission sensor, gas sensor, and pressure sensor for temperatures up to 1,250 °C were reviewed. Finally, discussions of existing challenges and future work for high-temperature piezoelectric sensing are presented.

Efficient Lossy Compression for Compressive Sensing Acquisition of Images in Compressive Sensing Imaging Systems

Directory of Open Access Journals (Sweden)

Xiangwei Li

2014-12-01

Full Text Available Compressive Sensing Imaging (CSI is a new framework for image acquisition, which enables the simultaneous acquisition and compression of a scene. Since the characteristics of Compressive Sensing (CS acquisition are very different from traditional image acquisition, the general image compression solution may not work well. In this paper, we propose an efficient lossy compression solution for CS acquisition of images by considering the distinctive features of the CSI. First, we design an adaptive compressive sensing acquisition method for images according to the sampling rate, which could achieve better CS reconstruction quality for the acquired image. Second, we develop a universal quantization for the obtained CS measurements from CS acquisition without knowing any a priori information about the captured image. Finally, we apply these two methods in the CSI system for efficient lossy compression of CS acquisition. Simulation results demonstrate that the proposed solution improves the rate-distortion performance by 0.4~2 dB comparing with current state-of-the-art, while maintaining a low computational complexity.

TMX-U neutral pressure measurement diagnostic systems

International Nuclear Information System (INIS)

Pickles, W.L.; Allen, S.L.; Hill, D.N.; Hunt, A.L.; Simonen, T.C.

1984-01-01

The Tandem Mirror Experiment-Upgrade (TMX-U) has a large and complex system of Baird Alpert, magnetron, and Penning gauges, in addition to mass spectrometers (RGA), all of which measure neutral pressures in the many internal regions of TMX-U. These pressure measurements are used as part of the confinement physics data base as well as for management of the TMX-U vacuum system. Dynamic pressures are modeled by a coupled-volumes simulation code, which includes wall reflus, getter pumping, and plasma pumping

A silicon micromachined resonant pressure sensor

International Nuclear Information System (INIS)

Tang Zhangyang; Fan Shangchun; Cai Chenguang

2009-01-01

This paper describes the design, fabrication and test of a silicon micromachined resonant pressure sensor. A square membrane and a doubly clamped resonant beam constitute a compound structure. The former senses the pressure directly, while the latter changes its resonant frequency according to deformation of the membrane. The final output relation between the resonant frequency and the applied pressure is deducted according to the structure mechanical properties. Sensors are fabricated by micromachining technology, and then sealed in vaccum. These sensors are tested by open-loop and close-loop system designed on purpose. The experiment results demonstrate that the sensor has a sensitivity of 49.8Hz/kPa and repeatability of 0.08%.

Research on distributed optical fiber sensing data processing method based on LabVIEW

Science.gov (United States)

Li, Zhonghu; Yang, Meifang; Wang, Luling; Wang, Jinming; Yan, Junhong; Zuo, Jing

2018-01-01

The pipeline leak detection and leak location problem have gotten extensive attention in the industry. In this paper, the distributed optical fiber sensing system is designed based on the heat supply pipeline. The data processing method of distributed optical fiber sensing based on LabVIEW is studied emphatically. The hardware system includes laser, sensing optical fiber, wavelength division multiplexer, photoelectric detector, data acquisition card and computer etc. The software system is developed using LabVIEW. The software system adopts wavelet denoising method to deal with the temperature information, which improved the SNR. By extracting the characteristic value of the fiber temperature information, the system can realize the functions of temperature measurement, leak location and measurement signal storage and inquiry etc. Compared with traditional negative pressure wave method or acoustic signal method, the distributed optical fiber temperature measuring system can measure several temperatures in one measurement and locate the leak point accurately. It has a broad application prospect.

Root-Contact/Pressure-Plate Assembly For Hydroponic System

Science.gov (United States)

Morris, Carlton E.; Loretan, Philip A.; Bonsi, Conrad K.; Hill, Walter A.

1994-01-01

Hydroponic system includes growth channels equipped with rootcontact/pressure-plate assemblies. Pump and associated plumbing circulate nutrient liquid from reservoir, along bottom of growth channels, and back to reservoir. Root-contact/pressure-plate assembly in each growth channel stimulates growth of roots by applying mild contact pressure. Flat plate and plate connectors, together constitute pressure plate, free to move upward to accommodate growth of roots. System used for growing sweetpotatoes and possibly other tuber and root crops.

[Construction of a low-pH-sensing system in Streptococcus mutans].

Science.gov (United States)

Di, Kang; Yuqing, Li; Xuedong, Zhou

2017-06-01

To construct a low-pH-sensing system in Streptococcus mutans (S. mutans) and to visually detect the pH in situ. Promoter of ureaseⅠ(PureⅠ) and green fluorescence protein (gfp) DNA fragments were amplified by polymerase chain reaction (PCR) from the genome of Streptococcus salivarius 57.I and S. mutans containing the gfp fragment. The two amplified DNA fragments were ligated together and further integrated into pDL278 to construct the recombinant plasmid pDL278-pureⅠ-gfp. This recombinant plasmid was then transformed into S. mutans UA159 cells. Subsequently, the intensity of the optical density per unit area of the low-pH-sensing system was measured and compared under different pH conditions and different processing times. PureⅠ and gfp DNA fragments were amplified successfully with the correct molecule sizes (450 and 717 bp, respectively). The recombinant plasmid pDL278-pureⅠ-gfp was constructed and further verified by PCR and sequencing. The intensity of the optical density per unit area of the low-pH-sensing system increased with decreasing pH and increasing processing time. A low-pH-sensing system was constructed successfully in S. mutans. Our research verified that pureⅠ of Streptococcus salivarius can function well in S. mutans as an acid induced promoter, and provided a new method of detecting the pH of plaque biofilms in situ.

Global Scale Remote Sensing Monitoring of Endorheic Lake Systems

Science.gov (United States)

Scuderi, L. A.

2010-12-01

Semi-arid regions of the world contain thousands of endorheic lakes in large shallow basins. Due to their generally remote locations few are continuously monitored. Documentation of recent variability is essential to assessing how endorheic lakes respond to short-term meteorological conditions and longer-term decadal-scale climatic variability and is critical in determining future disturbance of hydrological regimes with respect to predicted warming and drying in the mid-latitudes. Short- and long-term departures from climatic averages, rapid environmental shifts and increased population pressures may result in significant fluctuations in the hydrologic budgets of these lakes and adversely impact endorheic lake/basin ecosystems. Information on flooding variability is also critical in estimating changes in P/E balances and on the production of exposed and easily deflated surfaces that may impact dust loading locally and regionally. In order to provide information on how these lakes respond we need to understand how entire systems respond hydrologically to different climatic inputs. This requires monitoring and analysis of regional to continental-scale systems. To date, this level of monitoring has not been achieved in an operational system. In order to assess the possibility of creating a global-scale lake inundation database we analyzed two contrasting lake systems in western North America (Mexico and New Mexico, USA) and China (Inner Mongolia). We asked two major questions: 1) is it possible to quickly and accurately quantify current lake inundation events in near real time using remote sensing? and, 2) is it possible to differentiate variable meteorological sources and resultant lake inundation responses using this type of database? With respect to these results we outline an automated lake monitoring approach using MODIS data and real-time processing systems that may provide future global monitoring capabilities.

Adaptive Sensing Based on Profiles for Sensor Systems

Directory of Open Access Journals (Sweden)

Yoshiteru Ishida

2009-10-01

Full Text Available This paper proposes a profile-based sensing framework for adaptive sensor systems based on models that relate possibly heterogeneous sensor data and profiles generated by the models to detect events. With these concepts, three phases for building the sensor systems are extracted from two examples: a combustion control sensor system for an automobile engine, and a sensor system for home security. The three phases are: modeling, profiling, and managing trade-offs. Designing and building a sensor system involves mapping the signals to a model to achieve a given mission.

High Pressure Electrolyzer System Evaluation

Science.gov (United States)

Prokopius, Kevin; Coloza, Anthony

2010-01-01

This report documents the continuing efforts to evaluate the operational state of a high pressure PEM based electrolyzer located at the NASA Glenn Research Center. This electrolyzer is a prototype system built by General Electric and refurbished by Hamilton Standard (now named Hamilton Sunstrand). It is capable of producing hydrogen and oxygen at an output pressure of 3000 psi. The electrolyzer has been in storage for a number of years. Evaluation and testing was performed to determine the state of the electrolyzer and provide an estimate of the cost for refurbishment. Pressure testing was performed using nitrogen gas through the oxygen ports to ascertain the status of the internal membranes and seals. It was determined that the integrity of the electrolyzer stack was good as there were no appreciable leaks in the membranes or seals within the stack. In addition to the integrity testing, an itemized list and part cost estimate was produced for the components of the electrolyzer system. An evaluation of the system s present state and an estimate of the cost to bring it back to operational status was also produced.

Intelligent Vision System for Door Sensing Mobile Robot

Directory of Open Access Journals (Sweden)

Jharna Majumdar

2012-08-01

Full Text Available Wheeled Mobile Robots find numerous applications in the Indoor man made structured environments. In order to operate effectively, the robots must be capable of sensing its surroundings. Computer Vision is one of the prime research areas directed towards achieving these sensing capabilities. In this paper, we present a Door Sensing Mobile Robot capable of navigating in the indoor environment. A robust and inexpensive approach for recognition and classification of the door, based on monocular vision system helps the mobile robot in decision making. To prove the efficacy of the algorithm we have designed and developed a ‘Differentially’ Driven Mobile Robot. A wall following behavior using Ultra Sonic range sensors is employed by the mobile robot for navigation in the corridors.  Field Programmable Gate Arrays (FPGA have been used for the implementation of PD Controller for wall following and PID Controller to control the speed of the Geared DC Motor.

Demonstration of a high speed hybrid electrical and optical sensing system for next generation launcher applications

Science.gov (United States)

Ibrahim, Selwan K.; O'Dowd, John A.; Honniball, Arthur; Bessler, Vivian; Farnan, Martin; O'Connor, Peter; Melicher, Milos; Gleeson, Danny

2017-09-01

The Future Launchers Preparatory Programme (FLPP) supported by the European Space Agency (ESA) has a goal of developing various launch vehicle system concepts and identifying the technologies required for the design of Europe's Next-Generation Launcher (NGL) while maintaining competitiveness on the commercial market. Avionics fiber optic sensing technology was investigated as part of the FLPP programme. Here we demonstrate and evaluate a high speed hybrid electrical/optical data acquisition system based on commercial off the shelf (COTS) technology capable of acquiring data from traditional electrical sensors and optical Fibre Bragg Grating (FBG) sensors. The proposed system consists of the KAM-500 data acquisition system developed by Curtis-Wright and the I4 tunable laser based fiber optic sensor interrogator developed by FAZ Technology. The key objective was to demonstrate the capability of the hybrid system to acquire data from traditional electrical sensors used in launcher applications e.g. strain, temperature and pressure in combination with optical FBG sensors, as well as data delivery to spacecraft avionics systems. The KAM-500 was configured as the main acquisition unit (MAU) and provided a 1 kHz sampling clock to the I4 interrogator that was configured as the secondary acquisition unit (SAU) to synchronize the data acquisition sample rate between both systems. The SAU acquired data from an array of optical FBG sensors, while the MAU data acquisition system acquired data from the electrical sensors. Data acquired from the optical sensors was processed by the FAZ I4 interrogation system and then encapsulated into UDP/IP packets and transferred to the KAM-500. The KAM-500 encapsulated the optical sensor data together with the data acquired from electrical sensors and transmitted the data over MIL-STD-1553 and Ethernet data interface. The temperature measurements resulted in the optical and electrical sensors performing on a par with each other, with all

Mixing height determination using remote sensing systems. General remarks

Energy Technology Data Exchange (ETDEWEB)

Beyrich, F. [BTU Cottbus, LS Umweltmeteorologie, Cottbus (Germany)

1997-10-01

Remote sensing systems can be considered today as a real alternative to classical soundings with respect to the MH (mixing height) determination. They have the basic advantage to allow continuous monitoring of the ABL (atmospheric boundary layer). Some technical issues which limit their operational use at present should be solved in the near future (frequency allocation, eye safety, costs). Taking into account specific operating conditions and the formulated-above requirements of a sounding system to be used for MH determination it becomes obvious that none of the available systems meets all of them, i.e., the `Mixing height-meter` does not exist. Therefore, reliable MH determination under a wide variety of conditions can be achieved only by integrating different instruments into a complex sounding system. The S-profiles provide a suitable data base for MH estimation from all types of remote sensing instruments. The criteria to deduce MH-values from these profiles should consider the structure type and the evolution stage of the ABL as well as the shape of the profiles. A certain kind of harmonization concerning these criteria should be achieved. MH values derived automatically from remote sensing data appear to be not yet reliable enough for direct operational use, they should be in any case critically examined by a trained analyst. Contemporary mathematical methods (wavelet transforms, fuzzy logics) are supposed to allow considerable progress in this field in the near future. (au) 19 refs.

The pressure suppression system

International Nuclear Information System (INIS)

Aust, E.

1985-01-01

Nuclear plants with boiling water reactors have a safety containment with a pressure suppression system (PSS). Proceeding on significant self-developments, today the three PSS-lines of General Electric Co. (GE), Kraftwerk Union AG (KWU) and ASEA-ATOM are predominant, which are currently represented by the MARK III type, the KWU type 72 and the BWR 75 containment. In addition, there are special developments for the nuclear ship propulsion and for the pressurized water reactors in the Soviet Union. Key design values of the PSS allow a first valuation of its loads during a hypothetical loss-of-coolant accident. (orig.) [de

Hard Decision Fusion based Cooperative Spectrum Sensing in Cognitive Radio System

Directory of Open Access Journals (Sweden)

N. Armi N.M. Saad

2013-09-01

Full Text Available Cooperative spectrum sensing was proposed to combat fading, noise uncertainty, shadowing, and even hidden node problem due to primary users (PUs activity that is not spatially localized. It improves the probability of detection by collaborating to detect PUs signal in cognitive radio (CR system as well. This paper studies cooperative spectrum sensing and signal detection in CR system by implementing hard decision combining in data fusion centre. Through computer simulation, we evaluate the performances of cooperative spectrum sensing and signal detection by employing OR and AND rules as decision combining. Energy detector is used to observe the presence of primary user (PU signal. Those results are compared to non-cooperative signal detection for evaluation. They show that cooperative technique has better performance than non-cooperative. Moreover, signal to noise ratio (SNR with greater than or equal 10 dB and 15 collaborated users in CR system has optimal value for probability of detection.

Modeling and Control of a teletruck using electronic load sensing

DEFF Research Database (Denmark)

Hansen, Rico Hjerm; Iversen, Asger Malte; Jensen, Mads Schmidt

2010-01-01

system is most commonly controlled using a hydro-mechanical control scheme called Hydraulic Load Sensing (HLS). However, with the demands for increased efficiency and controllability the HLS solutions are reaching their limits. Motivated by availability of electronic controllable fluid power...... components and the potential of increased dynamic performance and efficiency, this paper investigates how HLS can be replaced with electronic control, i.e. Electronic Load Sensing (ELS). The investigation is performed by taking a specific application, a teletruck, and replace the HLS control with ELS. To aid...... the controller design for the ELS system, a complete model of the teletruck’s articulated arm and fluid power system is developed. To show the feasibility, a preliminary control structure for the ELS system is developed. The controller is tested on the machine, validating that features such as pump pressure...

Optial sensing systems for microfluidic devices: a review

NARCIS (Netherlands)

Kuswandi, Bambang; Nuriman, [Unknown; Huskens, Jurriaan; Verboom, Willem

2007-01-01

This review deals with the application of optical sensing systems for microfluidic devices. In the “off-chip approach” macro-scale optical infrastructure is coupled, while the “on-chip approach” comprises the integration of micro-optical functions into microfluidic devices. The current progress of

Readout Distance Enhancement of the Passive Wireless Multi-Parameter Sensing System Using a Repeater Coil

Directory of Open Access Journals (Sweden)

Lifeng Wang

2018-01-01

Full Text Available A repeater coil is used to extend the detection distance of a passive wireless multi-parameter sensing system. The passive wireless sensing system has the ability of simultaneously monitoring three parameters by using backscatter modulation together with channel multiplexing. Two different repeater coils are designed and fabricated for readout distance enhancement of the sensing system: one is a PCB (printed circuit board repeater coil, and the other is a copper wire repeater coil. Under the conditions of fixed voltage and adjustable voltage, the maximum readout distance of the sensing system with and without a repeater coil is measured. Experimental results show that larger power supply voltage can help further increase the readout distance. The maximum readout distance of the sensing system with a PCB repeater coil has been extended 2.3 times, and the one with a copper wire repeater coil has been extended 3 times. Theoretical analysis and experimental results both indicate that the high Q factor repeater coil can extend the readout distance more. With the copper wire repeater coil as well as a higher power supply voltage, the passive wireless multi-parameter sensing system finally achieves a maximum readout distance of 13.5 cm.

Method for sensing and measuring a concentration or partial pressure of a reactant used in a redox reaction

Science.gov (United States)

Findl, E.

1984-12-21

A method for sensing or measuring the partial pressure or concentration of an electroactive species used in conjunction with an electrolyte, the method being characterized by providing a constant current between an anode and a cathode of an electrolyte-containing cell, while measuring changes in voltage that occur between either the anode and cathode or between a reference electrode and one of the main electrodes of the cell, thereby to determine the concentration or partial pressure of the electro-active species as a function of said measured voltage changes. The method of the invention can be practiced using either a cell having only an anode and a cathode, or using a cell having an anode and a cathode in combination with a reference electrode. Accurate measurements of small concentrations or partial pressures of electro-active species are obtainable with the method of the invention, by using constant currents of only a few microamperes between the anode and cathode of the cell, while the concentration-determining voltage is measured.

Pressure map technology for pressure ulcer patients: can we handle the truth?

Science.gov (United States)

Pompeo, Matthew Q

2013-02-01

Objective. The purpose of this study was to trial new pressure mapping technology for patients with pressure ulcers. Pressure mapping data was recorded during 3 phases of technology implementation, as nurses became increasingly familiar with pressuremapping technology in a 55-bed, long-term acute care (LTAC) facility in North Texas. Forty-three patients with pressure ulcers were selected for the study. Patients with pressure ulcers, or who were considered at high risk for developing pressure ulcers based on a Braden score of ≤ 12, were selected to utilize a pressure-sensing device system. Turning timeliness improved greatly from the baseline phase to the last phase. The average turning after the 2-hour alarm decreased from 120 minutes to 44 minutes, and the median time to turning decreased from 39 minutes to 17 minutes. If time past 2 hours is considered the most damaging time to tissue, these reductions (average and median) represented 63% and 56% less potential tissue damage. Pressure mapping technology is in its infancy and this paper discusses implications for the future, including barriers to implementation and potential advanced applications. While only changes in nursing practice were measured in this study, the changes observed suggest the technology can be instrumental in reducing hospital-acquired pressure ulcers and improving the healing of pressure wounds in the future. .

Wireless Capacitive Pressure Sensor Operating up to 400 Celcius from 0 to 100 psi Utilizing Power Scavenging

Science.gov (United States)

Scardelletti, Maximilian C.; Ponchak, George E.; Harsh, Kevin; Mackey, Jonathan A.; Meredith, Roger D.; Zorman, Christian A.; Beheim, Glenn M.; Dynys, Frederick W.; Hunter, Gary W.

2014-01-01

In this paper, a wireless capacitive pressure sensor developed for the health monitoring of aircraft engines has been demonstrated. The sensing system is composed of a Clapp-type oscillator that operates at 131 MHz. The Clapp oscillator is fabricated on a alumina substrate and consists of a Cree SiC (silicon carbide) MESFET (Metal Semiconductor Field Effect Transistors), this film inductor, Compex chip capacitors and Sporian Microsystem capacitive pressure sensor. The resonant tank circuit within the oscillator is made up of the pressure sensor and a spiral thin film inductor, which is used to magnetically couple the wireless pressure sensor signal to a coil antenna placed over 1 meter away. 75% of the power used to bias the sensing system is generated from thermoelectric power modules. The wireless pressure sensor is operational at room temperature through 400 C from 0 to 100 psi and exhibits a frequency shift of over 600 kHz.

Modal sensing and control of paraboloidal shell structronic system

Science.gov (United States)

Yue, Honghao; Lu, Yifan; Deng, Zongquan; Tzou, Hornsen

2018-02-01

Paraboloidal shells of revolution are commonly used as important components in the field of advanced aerospace structures and aviation mechanical systems. This study is to investigate the modal sensing behavior and the modal vibration control effect of distributed PVDF patches laminated on the paraboloidal shell. A paraboloidal shell sensing and control testing platform is set up first. Frequencies of lower order modes of the shell are obtained with the PVDF sensor and compared with the previous testing results to prove its accuracy. Then sensor patches are laminated on different positions (or different sides) of the shell and tested to reveal the relation between the sensing behaviors and their locations. Finally, a mathematical model of the structronic system is built by parameter identifications and the transfer function is derived. Independent and coupled modal controllers are designed based on the pole placement method and modal vibration control experiments are performed. The amplitude suppression ratio of each mode controlled by the pole placement controller is calculated and compared with the results obtained by using a PPF controller. Advantages of both methods are concluded and suggestions are given on how to choose control algorithm for different purpose.

Fuzzy control applied to nuclear power plant pressurizer system

International Nuclear Information System (INIS)

Oliveira, Mauro V.; Almeida, Jose C.S.

2011-01-01

In a pressurized water reactor (PWR) nuclear power plants (NPPs) the pressure control in the primary loop is very important for keeping the reactor in a safety condition and improve the generation process efficiency. The main component responsible for this task is the pressurizer. The pressurizer pressure control system (PPCS) utilizes heaters and spray valves to maintain the pressure within an operating band during steady state conditions, and limits the pressure changes, during transient conditions. Relief and safety valves provide overpressure protection for the reactor coolant system (RCS) to ensure system integrity. Various protective reactor trips are generated if the system parameters exceed safe bounds. Historically, a proportional-integral derivative (PID) controller is used in PWRs to keep the pressure in the set point, during those operation conditions. The purpose of this study has two main goals: first is to develop a pressurizer model based on artificial neural networks (ANNs); second is to develop a fuzzy controller for the PWR pressurizer pressure, and compare its performance with the P controller. Data from a simulator PWR plant was used to test the ANN and the controllers as well. The reference simulator is a Westinghouse 3-loop PWR plant with a total thermal output of 2785 MWth. The simulation results show that the pressurizer ANN model response are in reasonable agreement with the simulated power plant, and the fuzzy controller built in this study has better performance compared to the P controller. (author)

Fuzzy control applied to nuclear power plant pressurizer system

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Mauro V.; Almeida, Jose C.S., E-mail: mvitor@ien.gov.b, E-mail: jcsa@ien.gov.b [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2011-07-01

In a pressurized water reactor (PWR) nuclear power plants (NPPs) the pressure control in the primary loop is very important for keeping the reactor in a safety condition and improve the generation process efficiency. The main component responsible for this task is the pressurizer. The pressurizer pressure control system (PPCS) utilizes heaters and spray valves to maintain the pressure within an operating band during steady state conditions, and limits the pressure changes, during transient conditions. Relief and safety valves provide overpressure protection for the reactor coolant system (RCS) to ensure system integrity. Various protective reactor trips are generated if the system parameters exceed safe bounds. Historically, a proportional-integral derivative (PID) controller is used in PWRs to keep the pressure in the set point, during those operation conditions. The purpose of this study has two main goals: first is to develop a pressurizer model based on artificial neural networks (ANNs); second is to develop a fuzzy controller for the PWR pressurizer pressure, and compare its performance with the P controller. Data from a simulator PWR plant was used to test the ANN and the controllers as well. The reference simulator is a Westinghouse 3-loop PWR plant with a total thermal output of 2785 MWth. The simulation results show that the pressurizer ANN model response are in reasonable agreement with the simulated power plant, and the fuzzy controller built in this study has better performance compared to the P controller. (author)

[Development of an automatic pneumatic tourniquet system that determines pressures in synchrony with systolic blood pressure].

Science.gov (United States)

Liu, Hongyun; Li, Kaiyuan; Zhang, Zhengbo; Guo, Junyan; Wang, Weidong

2012-11-01

The correlation coefficients between arterial occlusion pressure and systolic blood pressure, diastolic blood pressure, limb circumference, body mass etc were obtained through healthy volunteer experiments, in which tourniquet were applied on upper/lower extremities. The prediction equations were derived from the data of experiments by multiple regression analysis. Based on the microprocessor C8051F340, a new pneumatic tourniquet system that can determine tourniquet pressure in synchrony with systolic blood pressure was developed and verified the function and stability of designed system. Results showed that the pneumatic tourniquet which automatically adjusts occlusion pressure in accordance with systolic blood pressure could stop the flow of blood to get a bloodless field.

Development of a CMOS MEMS pressure sensor with a mechanical force-displacement transduction structure

International Nuclear Information System (INIS)

Cheng, Chao-Lin; Chang, Heng-Chung; Fang, Weileun; Chang, Chun-I

2015-01-01

This study presents a capacitive pressure sensor with a mechanical force-displacement transduction structure based on the commercially available standard CMOS process (the TSMC 0.18 μm 1P6M CMOS process). The pressure sensor has a deformable diaphragm to support a movable plate with an embedded sensing electrode. As the diaphragm is deformed by the ambient pressure, the movable plate and its embedded sensing electrode are displaced. Thus, the pressure is detected from the capacitance change between the movable and fixed electrodes. The undeformed movable electrode will increase the effective sensing area between the sensing electrodes, thereby improving the sensitivity. Experimental results show that the proposed pressure sensor with a force-displacement transducer will increase the sensitivity by 126% within the 20 kPa–300 kPa absolute pressure range. Moreover, this study extends the design to add pillars inside the pressure sensor to further increase its sensing area as well as sensitivity. A sensitivity improvement of 117% is also demonstrated for a pressure sensor with an enlarged sensing electrode (the overlap area is increased two fold). (paper)

A Three-Dimensional Microdisplacement Sensing System Based on MEMS Bulk-Silicon Technology

Science.gov (United States)

Wu, Junjie; Lei, Lihua; Chen, Xin; Cai, Xiaoyu; Li, Yuan; Han, Tao

2014-01-01

For the dimensional measurement and characterization of microsized and nanosized components, a three-dimensional microdisplacement sensing system was developed using the piezoresistive effect in silicon. The sensor was fabricated using microelectromechanical system bulk-silicon technology, and it was validated using the finite element method. A precise data acquisition circuit with an accuracy of 20 μV was designed to obtain weak voltage signals. By calibration, the sensing system was shown to have a sensitivity of 17.29 mV/μm and 4.59 mV/μm in the axial and lateral directions, respectively; the nonlinearity in these directions was 0.8% and 1.0% full scale, respectively. A full range of 4.6 μm was achieved in the axial direction. Results of a resolution test indicated that the sensing system had a resolution of 5 nm in the axial direction and 10 nm in the lateral direction. PMID:25360581

A Three-Dimensional Microdisplacement Sensing System Based on MEMS Bulk-Silicon Technology

Directory of Open Access Journals (Sweden)

Junjie Wu

2014-10-01

Full Text Available For the dimensional measurement and characterization of microsized and nanosized components, a three-dimensional microdisplacement sensing system was developed using the piezoresistive effect in silicon. The sensor was fabricated using microelectromechanical system bulk-silicon technology, and it was validated using the finite element method. A precise data acquisition circuit with an accuracy of 20 μV was designed to obtain weak voltage signals. By calibration, the sensing system was shown to have a sensitivity of 17.29 mV/μm and 4.59 mV/μm in the axial and lateral directions, respectively; the nonlinearity in these directions was 0.8% and 1.0% full scale, respectively. A full range of 4.6 μm was achieved in the axial direction. Results of a resolution test indicated that the sensing system had a resolution of 5 nm in the axial direction and 10 nm in the lateral direction.

Distributed illumination control with local sensing and actuation in networked lighting systems

NARCIS (Netherlands)

Caicedo Fernandez, D.R.; Pandharipande, A.

2013-01-01

We consider the problem of illumination control in a networked lighting system wherein luminaires have local sensing and actuation capabilities. Each luminaire (i) consists of a light emitting diode (LED) based light source dimmable by a local controller, (ii) is actuated based on sensing

Response of Kondo lattice systems to pressure

International Nuclear Information System (INIS)

Thompson, J.D.; Borges, H.A.; Fisk, Z.; Horn, S.; Parks, R.D.; Wells, G.L.

1987-01-01

Yb-based Kondo lattice systems (YbAgCu 4 , YbCu 2 Si 2 , YbRh 2 Si 2 ) represent an interesting class of materials in which it is possible to study systematically the development of heavy electron behavior through the application of pressure. Certainly, additional experiments are required to determine to what extent Yb compounds are mirror images of their Ce counterparts. Finally, pressure reveals the presence of competing interactions for which a simple model exists that qualitatively accounts for the pressure response observed in a large number of Ce, U and Yb-based Kondo lattice systems

Micro-system inertial sensing technology overview.

Energy Technology Data Exchange (ETDEWEB)

Allen, James Joe

2009-02-01

The purpose of this report is to provide an overview of Micro-System technology as it applies to inertial sensing. Transduction methods are reviewed with capacitance and piezoresistive being the most often used in COTS Micro-electro-mechanical system (MEMS) inertial sensors. Optical transduction is the most recent transduction method having significant impact on improving sensor resolution. A few other methods are motioned which are in a R&D status to hopefully allow MEMS inertial sensors to become viable as a navigation grade sensor. The accelerometer, gyroscope and gravity gradiometer are the type of inertial sensors which are reviewed in this report. Their method of operation and a sampling of COTS sensors and grade are reviewed as well.

Remote-sensing imperatives of the Global Ocean Observing System (GOOS)

Digital Repository Service at National Institute of Oceanography (India)

Summerhayes, C.; Desa, E.; Swamy, G.N.

is crucial. The tasks are thus to advance the function of remote-sensing algorithms to encompass those variables which are presently monitored by in situ systems, leaving these systems to act more as sea-truth validators than as in situ data suppliers...

Incorporation of the pressure control system to the classroom simulator

International Nuclear Information System (INIS)

Sanchez J, J.

2004-01-01

In the nucleo electric centrals, the information systems, support for the decisions making and training are every day more complex and important. The present work is a contribution in this sense, specifically, it is part of a tool of training and analysis developed by the Laboratory of Analysis in Engineering of Nuclear Reactors (LAIRN) of the Faculty of Engineering of the UNAM that consists essentially of a simulator of the Laguna Verde Nucleo electric plant; the classroom simulator, understands the physical systems that compose to the power station and graphic interfaces for its operation and the analysis of results. The project of the classroom simulator is carried out in independent modules that are integrated to the total system as these they are developed and proven. The central objective of this work consists on the development, implementation and it proves of a model of the pressure control system according to the characteristics of the Nucleo electric plant of Laguna Verde, as well as the development of the mimic ones and unfolding necessary graphics to make its interactive operation from sensitive monitors to the tact. The pattern of the control system was developed using as tool the nuclear code of simulation RELAP/SCDAP, designed for the analysis of the types of nuclear reactors more common in occident, and it allows the typical maneuvers in the ways of start up, heating and operation to power, showing an appropriate behavior during the more common operational transitoriness. (Author)

Role of pressuriser in enhancing pressure control system capability in primary system of 500 MWe PHWR

Energy Technology Data Exchange (ETDEWEB)

Walia, M P.S.; Misri, Vijay; Bapat, C N; Sharma, V K [Nuclear Power Corporation, Bhabha Atomic Research Centre, Mumbai (India)

1994-06-01

The primary heat transport system of a pressurized heavy water reactor (PHWR) extracts and transports the heat produced in the fuel (located inside coolant channel assemblies) to the steam generators where steam is generated to run the turbo-generator. The heat transport medium (primary coolant) is heavy water which is kept in a pressurized liquid state with the help of a pressure control system. Feed and bleed circuits with associated equipment of PHT main system have traditionally constituted the pressure control system. However, for large size reactors of 500 MWe capacity, a surge tank known as pressurizer was incorporated due to the presence of relatively large inventory in PHT main circuit. The pressurizer acts as a cushion for pressure variations resulting from various transients. This significantly reduces the onerous demand on feed and bleed system, thereby reducing reactor outages on system pressure excursions. The paper describes in detail the pressure control system of 500 MWe PHWR involving pressuriser and feed and bleed system including their functions and instrumentation. The results of mathematical modelling/analysis undertaken to establish the response adequacy of pressure control system, to postulated plant transients vis-a-vis the role of pressurizer are presented. (author). 10 figs.

A Novel RFID Sensing System Using Enhanced Surface Wave Technology for Battery Exchange Stations

Directory of Open Access Journals (Sweden)

Yeong-Lin Lai

2014-01-01

Full Text Available This paper presents a novel radio-frequency identification (RFID sensing system using enhanced surface wave technology for battery exchange stations (BESs of electric motorcycles. Ultrahigh-frequency (UHF RFID technology is utilized to automatically track and manage battery and user information without manual operation. The system includes readers, enhanced surface wave leaky cable antennas (ESWLCAs, coupling cable lines (CCLs, and small radiation patches (SRPs. The RFID sensing system overcomes the electromagnetic interference in the metallic environment of a BES cabinet. The developed RFID sensing system can effectively increase the efficiency of BES operation and promote the development of electric vehicles which solve the problem of air pollution as well as protect the environment of the Earth.

All-optical pressure sensor

DEFF Research Database (Denmark)

2014-01-01

The present invention relates to an all-optical pressure sensor comprising a waveguide accommodating a distributed Bragg reflector. Pressure sensing can then be provided by utilizing effective index modulation of the waveguide and detection of a wavelength shift of light reflected from the Bragg...... reflector. Sound sensing may also be provided thereby having an all-optical microphone. One embodiment of the invention relates to an optical pressure sensor comprising at least one outer membrane and a waveguide, the waveguide comprising at least one core for confining and guiding light,at least one...... distributed Bragg reflector located in said at least one core, and at least one inner deflecting element forming at least a part of the core,wherein the pressure sensor is configured such that the geometry and/or dimension of the at least one core is changed when the at least one outer membrane is submitted...

Integration and road tests of a self-sensing CNT concrete pavement system for traffic detection

Science.gov (United States)

Han, Baoguo; Zhang, Kun; Burnham, Tom; Kwon, Eil; Yu, Xun

2013-01-01

In this paper, a self-sensing carbon nanotube (CNT) concrete pavement system for traffic detection is proposed and tested in a roadway. Pre-cast and cast-in-place self-sensing CNT concrete sensors were simultaneously integrated into a controlled pavement test section at the Minnesota Road Research Facility (MnROAD), USA. Road tests of the system were conducted by using an MnROAD five-axle semi-trailer tractor truck and a van, respectively, both in the winter and summer. Test results show that the proposed self-sensing pavement system can accurately detect the passing of different vehicles under different vehicular speeds and test environments. These findings indicate that the developed self-sensing CNT concrete pavement system can achieve real-time vehicle flow detection with a high detection rate and a low false-alarm rate.

Integration and road tests of a self-sensing CNT concrete pavement system for traffic detection

International Nuclear Information System (INIS)

Han, Baoguo; Zhang, Kun; Yu, Xun; Burnham, Tom; Kwon, Eil

2013-01-01

In this paper, a self-sensing carbon nanotube (CNT) concrete pavement system for traffic detection is proposed and tested in a roadway. Pre-cast and cast-in-place self-sensing CNT concrete sensors were simultaneously integrated into a controlled pavement test section at the Minnesota Road Research Facility (MnROAD), USA. Road tests of the system were conducted by using an MnROAD five-axle semi-trailer tractor truck and a van, respectively, both in the winter and summer. Test results show that the proposed self-sensing pavement system can accurately detect the passing of different vehicles under different vehicular speeds and test environments. These findings indicate that the developed self-sensing CNT concrete pavement system can achieve real-time vehicle flow detection with a high detection rate and a low false-alarm rate. (paper)

A comparison of inferface pressures of three compression bandage systems.

Science.gov (United States)

Hanna, Richard; Bohbot, Serge; Connolly, Nicki

To measure and compare the interface pressures achieved with two compression bandage systems - a four-layer system (4LB) and a two-layer short-stretch system (SSB) - with a new two-layer system (2LB), which uses an etalonnage (performance indicator) to help achieve the correct therapeutic pressure for healing venous leg ulcers - recommended as 40 mmHg. 32 nurses with experience of using compression bandages applied each of the three systems to a healthy female volunteer in a sitting position. The interface pressures and time taken to apply the systems were measured. A questionnaire regarding the concept of the new system and its application in comparison to the existing two systems was then completed by the nurses. The interface pressures achieved show that many nurses applied very high pressures with the 4LB (25% achieving pressures > 50 mmHg) whereas the majority of the nurses (75%) achieved a pressure of pressure of 30-50 mmHg was achieved with the new 2LB. The SSB took the least time to be applied (mean: 1 minute 50 seconds) with the 4LB the slowest (mean: 3 minutes 46 seconds). A mean time of 2 minutes 35 seconds was taken to apply the 2LB. Over 63% of the nurses felt the 2LB was very easy to apply. These results suggest that the 2LB achieves the required therapeutic pressure necessary for the management of venous leg ulcers, is easy to apply and may provide a suitable alternative to other multi-layer bandage systems.

On-Board, Real-Time Preprocessing System for Optical Remote-Sensing Imagery.

Science.gov (United States)

Qi, Baogui; Shi, Hao; Zhuang, Yin; Chen, He; Chen, Liang

2018-04-25

With the development of remote-sensing technology, optical remote-sensing imagery processing has played an important role in many application fields, such as geological exploration and natural disaster prevention. However, relative radiation correction and geometric correction are key steps in preprocessing because raw image data without preprocessing will cause poor performance during application. Traditionally, remote-sensing data are downlinked to the ground station, preprocessed, and distributed to users. This process generates long delays, which is a major bottleneck in real-time applications for remote-sensing data. Therefore, on-board, real-time image preprocessing is greatly desired. In this paper, a real-time processing architecture for on-board imagery preprocessing is proposed. First, a hierarchical optimization and mapping method is proposed to realize the preprocessing algorithm in a hardware structure, which can effectively reduce the computation burden of on-board processing. Second, a co-processing system using a field-programmable gate array (FPGA) and a digital signal processor (DSP; altogether, FPGA-DSP) based on optimization is designed to realize real-time preprocessing. The experimental results demonstrate the potential application of our system to an on-board processor, for which resources and power consumption are limited.

On-Board, Real-Time Preprocessing System for Optical Remote-Sensing Imagery

Science.gov (United States)

Qi, Baogui; Zhuang, Yin; Chen, He; Chen, Liang

2018-01-01

With the development of remote-sensing technology, optical remote-sensing imagery processing has played an important role in many application fields, such as geological exploration and natural disaster prevention. However, relative radiation correction and geometric correction are key steps in preprocessing because raw image data without preprocessing will cause poor performance during application. Traditionally, remote-sensing data are downlinked to the ground station, preprocessed, and distributed to users. This process generates long delays, which is a major bottleneck in real-time applications for remote-sensing data. Therefore, on-board, real-time image preprocessing is greatly desired. In this paper, a real-time processing architecture for on-board imagery preprocessing is proposed. First, a hierarchical optimization and mapping method is proposed to realize the preprocessing algorithm in a hardware structure, which can effectively reduce the computation burden of on-board processing. Second, a co-processing system using a field-programmable gate array (FPGA) and a digital signal processor (DSP; altogether, FPGA-DSP) based on optimization is designed to realize real-time preprocessing. The experimental results demonstrate the potential application of our system to an on-board processor, for which resources and power consumption are limited. PMID:29693585

Current development of UAV sense and avoid system

Science.gov (United States)

Zhahir, A.; Razali, A.; Mohd Ajir, M. R.

2016-10-01

As unmanned aerial vehicles (UAVs) are now gaining high interests from civil and commercialised market, the automatic sense and avoid (SAA) system is currently one of the essential features in research spotlight of UAV. Several sensor types employed in current SAA research and technology of sensor fusion that offers a great opportunity in improving detection and tracking system are presented here. The purpose of this paper is to provide an overview of SAA system development in general, as well as the current challenges facing UAV researchers and designers.

Optical detection system for MEMS-type pressure sensor

International Nuclear Information System (INIS)

Sareło, K; Górecka-Drzazga, A; Dziuban, J A

2015-01-01

In this paper a special optical detection system designed for a MEMS-type (micro-electro-mechanical system) silicon pressure sensor is presented. The main part of the optical system—a detection unit with a perforated membrane—is bonded to the silicon sensor, and placed in a measuring system. An external light source illuminates the membrane of the pressure sensor. Owing to the light reflected from the deflected membrane sensor, the optical pattern consisting of light points is visible, and pressure can be estimated. The optical detection unit (20   ×   20   ×   20.4 mm 3 ) is fabricated using microengineering techniques. Its dimensions are adjusted to the dimensions of the pressure sensor (5   ×   5 mm 2 silicon membrane). Preliminary tests of the optical detection unit integrated with the silicon pressure sensor are carried out. For the membrane sensor from 15 to 60 µm thick, a repeatable detection of the differential pressure in the range of 0 to 280 kPa is achieved. The presented optical microsystem is especially suitable for the pressure measurements in a high radiation environment. (paper)

Strain sensing systems tailored for tensile measurement of fragile wires

Science.gov (United States)

Nyilas, Arman

2005-12-01

Fundamental stress versus strain measurements were completed on superconducting Nb3Sn wires within the framework of IEC/TC90 and VAMAS/TWA16. A key task was the assessment of sensing systems regarding resolution, accuracy, and precision when measuring Young's modulus. Prior to actual Nb3Sn wire measurements metallic wires, consisting of copper and stainless steel having diameters similar to the Nb3Sn wire, were extensively investigated with respect to their elastic line properties using different types of extensometers. After these calibration tests Nb3Sn wire measurements of different companies resulted in several important facts with respect to total size and weight of the used extensometers. The size could be correlated to the initial stage of stress versus strain behaviour. In fact, the effect of wire curls resulting from the production line had a profound effect on Young's modulus measurements. Within this context, the possibility of determining Young's modulus from unloading compliance lines in the plastic regime of the stress-strain curve was considered. The data obtained using this test methodology were discussed under consideration of the composite nature of Nb3Sn wire. In addition, a non-contacting sensing system based on a double-beam laser extensometer was used to investigate the potential of this new sensing system.

Strain sensing systems tailored for tensile measurement of fragile wires

International Nuclear Information System (INIS)

Nyilas, Arman

2005-01-01

Fundamental stress versus strain measurements were completed on superconducting Nb 3 Sn wires within the framework of IEC/TC90 and VAMAS/TWA16. A key task was the assessment of sensing systems regarding resolution, accuracy, and precision when measuring Young's modulus. Prior to actual Nb 3 Sn wire measurements metallic wires, consisting of copper and stainless steel having diameters similar to the Nb 3 Sn wire, were extensively investigated with respect to their elastic line properties using different types of extensometers. After these calibration tests Nb 3 Sn wire measurements of different companies resulted in several important facts with respect to total size and weight of the used extensometers. The size could be correlated to the initial stage of stress versus strain behaviour. In fact, the effect of wire curls resulting from the production line had a profound effect on Young's modulus measurements. Within this context, the possibility of determining Young's modulus from unloading compliance lines in the plastic regime of the stress-strain curve was considered. The data obtained using this test methodology were discussed under consideration of the composite nature of Nb 3 Sn wire. In addition, a non-contacting sensing system based on a double-beam laser extensometer was used to investigate the potential of this new sensing system

A mobile sensing system for structural health monitoring: design and validation

International Nuclear Information System (INIS)

Zhu, Dapeng; Yi, Xiaohua; Wang, Yang; Lee, Kok-Meng; Guo, Jiajie

2010-01-01

This paper describes a new approach using mobile sensor networks for structural health monitoring. Compared with static sensors, mobile sensor networks offer flexible system architectures with adaptive spatial resolutions. The paper first describes the design of a mobile sensing node that is capable of maneuvering on structures built with ferromagnetic materials. The mobile sensing node can also attach/detach an accelerometer onto/from the structural surface. The performance of the prototype mobile sensor network has been validated through laboratory experiments. Two mobile sensing nodes are adopted for navigating on a steel portal frame and providing dense acceleration measurements. Transmissibility function analysis is conducted to identify structural damage using data collected by the mobile sensing nodes. This preliminary work is expected to spawn transformative changes in the use of mobile sensors for future structural health monitoring

A mobile sensing system for structural health monitoring: design and validation

Science.gov (United States)

Zhu, Dapeng; Yi, Xiaohua; Wang, Yang; Lee, Kok-Meng; Guo, Jiajie

2010-05-01

This paper describes a new approach using mobile sensor networks for structural health monitoring. Compared with static sensors, mobile sensor networks offer flexible system architectures with adaptive spatial resolutions. The paper first describes the design of a mobile sensing node that is capable of maneuvering on structures built with ferromagnetic materials. The mobile sensing node can also attach/detach an accelerometer onto/from the structural surface. The performance of the prototype mobile sensor network has been validated through laboratory experiments. Two mobile sensing nodes are adopted for navigating on a steel portal frame and providing dense acceleration measurements. Transmissibility function analysis is conducted to identify structural damage using data collected by the mobile sensing nodes. This preliminary work is expected to spawn transformative changes in the use of mobile sensors for future structural health monitoring.

Pulse mode actuation-readout system based on MEMS resonator for liquid sensing

DEFF Research Database (Denmark)

Tang, Meng; Cagliani, Alberto; Davis, Zachary James

2014-01-01

A MEMS (Micro-Electro-Mechanical Systems) bulk disk resonator is applied for mass sensing under its dynamic mode. The classical readout circuitry involves sophisticated feedback loop and feedthrough compensation. We propose a simple straightforward non-loop pulse mode actuation and capacitive...... readout scheme. In order to verify its feasibility in liquid bio-chemical sensing environment, an experimental measurement is conducted with humidity sensing application. The measured resonant frequency changes 60kHz of 67.7MHz with a humidity change of 0~80%....

Variability of the Quorum Sensing System in Natural Isolates of Bacillus sp.

Directory of Open Access Journals (Sweden)

Ines Mandic-Mulec

2003-01-01

Full Text Available Bacteria communicate with one another by (emitting and/or reacting to chemical signals. These communications, also known as quorum sensing, enable cells to control gene expression in response to cell density at the intra- and inter-species level. While bacteria use common signaling themes, variations in the design of the extracellular signals, the signal detection apparatus, and the biochemical mechanisms of signal relay have allowed quorum sensing systems to be adapted to diverse uses. The quorum sensing systems that govern natural genetic competence in Bacillus subtilis involve the ComX pheromones and the ComP-ComA, two-component regulator. ComX is synthesized as an inactive precursor and is then cleaved and modified by ComQ before export to the extra-cellular environment. The comQXP' loci of a set of natural Bacillus isolates have been sequenced and a striking polymorphism that correlates with specific patterns of activation of the quorum sensing response was shown. The ComX molecules representing different pherotypes were purified and characterized by mass spectroscopy. The analyses revealed that ComX variants also differ at the level of posttranslational modification of a conserved tryptophane residue, which was found to be an isoprenoid. The striking variability found in competence quorum sensing systems might be important for the survival of these bacteria in nature to escape the inappropriate induction of competence by closely related strains, playing the role of a sexual isolation mechanism.

A highly stable electrochemiluminescence sensing system of cadmium sulfide nanowires/graphene hybrid for supersensitive detection of pentachlorophenol

Science.gov (United States)

Deng, Yanan; Chang, Quanying; Yin, Kai; Liu, Chengbin; Wang, Ying

2017-10-01

A highly stable and effective electrochemiluminescence (ECL) sensing system of cadmium sulfide nanowires/reduced graphene oxide (CdS NWS/rGO) hybrid is presented for supersensitive detection of pentachlorophenol (PCP). CdS nanowire is for the first time exploited in ECL sensing. The rGO served as both ECL signal amplifier and immobilization platform, can perfectly enhance the ECL intensity and stability of the sensing system. With S2O82- as coreactant, the ECL signal can be significantly quenched by the addition of PCP. The established ECL sensing system presents a wider linear range from 1.0 × 10-14 to 1.0 × 10-8 M and a much low detection limit of 2 × 10-15 M under the optimum test conditions (e.g., pH 7.0 and 100 mM S2O82-). Furthermore, the ECL sensing system displays a good selectivity for PCP detection. The practicability of the ECL sensing system in real water sample shows that this system could be promisingly applied in the analytical detection of PCP in real water environments.

Chlorine-trapped CVD bilayer graphene for resistive pressure sensor with high detection limit and high sensitivity

Science.gov (United States)

Phuong Pham, Viet; Triet Nguyen, Minh; Park, Jin Woo; Kwak, Sung Soo; Nguyen, Dieu Hien Thi; Kyeom Mun, Mu; Danh Phan, Hoang; San Kim, Doo; Kim, Ki Hyun; Lee, Nae-Eung; Yeom, Geun Young

2017-06-01

Pressure sensing is one of the key functions for smart electronics. Considerably more effort is required to achieve the fabrication of pressure sensors that can imitate and overcome the sophisticated pressure sensing characteristics in nature and industry, especially in the innovation of materials and structures. Almost all of the pressure sensors reported until now have a high sensitivity at a low-pressure detection limit (type chlorine trap doping in the channel graphene with chlorine radicals without damaging the graphene. This work indicates that the ZGClG channel used for the pressure sensing device could also provide a simple and essential sensing platform for chemical-, medical-, and biological-sensing for future smart electronics.

Fuzzy logic control for improved pressurizer systems in nuclear power plants

International Nuclear Information System (INIS)

Brown, Chris; Gabbar, Hossam A.

2014-01-01

Highlights: • Improved performance of the pressurizer system in a CANDU nuclear power plant (NPP). • Inventory control for the pressurizer system in NPP. • Compare fuzzy logic with PID in pressurizer system in NPP. • Develop a fuzzy controller to regulate the pressurizer inventory control. • Compare control performance with current proportional controller used at NPP. - Abstract: The pressurizer system in a CANDU nuclear power plant is responsible for maintaining the pressure of the primary heat transport system to ensure the plant is operated within its safe operating envelope. The inventory control for the pressurizer system use a combination of level sensors, feed valves and bleed valves to ensure that there is adequate room in the pressurizer to accommodate any swell or shrinkage in the PHT system. The Darlington Nuclear Generating Station (DNGS) in Ontario, Canada currently uses a proportional controller for the bleed and feed valves to regulate the pressurizer inventory control which can result in large coolant level overshoot along with excessive settling times. The purpose of this paper is to develop a fuzzy controller to regulate the pressurizer inventory control and compare its performance to the current proportional controller used at DNGS. The simulation of the pressurizer inventory control system shows the fuzzy controller performs better than the proportional controller in terms of settling time and overshoot

Reaction Force/Torque Sensing in a Master-Slave Robot System without Mechanical Sensors

Directory of Open Access Journals (Sweden)

Kyoko Shibata

2010-07-01

Full Text Available In human-robot cooperative control systems, force feedback is often necessary in order to achieve high precision and high stability. Usually, traditional robot assistant systems implement force feedback using force/torque sensors. However, it is difficult to directly mount a mechanical force sensor on some working terminals, such as in applications of minimally invasive robotic surgery, micromanipulation, or in working environments exposed to radiation or high temperature. We propose a novel force sensing mechanism for implementing force feedback in a master-slave robot system with no mechanical sensors. The system consists of two identical electro-motors with the master motor powering the slave motor to interact with the environment. A bimanual coordinated training platform using the new force sensing mechanism was developed and the system was verified in experiments. Results confirm that the proposed mechanism is capable of achieving bilateral force sensing and mirror-image movements of two terminals in two reverse control directions.

Flexible Sensing Electronics for Wearable/Attachable Health Monitoring.

Science.gov (United States)

Wang, Xuewen; Liu, Zheng; Zhang, Ting

2017-07-01

Wearable or attachable health monitoring smart systems are considered to be the next generation of personal portable devices for remote medicine practices. Smart flexible sensing electronics are components crucial in endowing health monitoring systems with the capability of real-time tracking of physiological signals. These signals are closely associated with body conditions, such as heart rate, wrist pulse, body temperature, blood/intraocular pressure and blood/sweat bio-information. Monitoring such physiological signals provides a convenient and non-invasive way for disease diagnoses and health assessments. This Review summarizes the recent progress of flexible sensing electronics for their use in wearable/attachable health monitoring systems. Meanwhile, we present an overview of different materials and configurations for flexible sensors, including piezo-resistive, piezo-electrical, capacitive, and field effect transistor based devices, and analyze the working principles in monitoring physiological signals. In addition, the future perspectives of wearable healthcare systems and the technical demands on their commercialization are briefly discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sensing System for Salinity Testing Using Laser-induced Graphene Sensors

KAUST Repository

Nag, Anindya

2017-08-05

The paper presents the development and implementation of a low-cost salinity sensing system. Commercial polymer films were laser ablated at specific conditions to form graphene-based sensors on flexible Kapton substrates. Sodium chloride was considered as the primary constituent for testing due to its prominent presence in water bodies. The sensor was characterized by testing different concentrations of sodium chloride. A standard curve was developed to perform real-time testing with a sample taken from sea water of unknown concentration. The sensitivity and resolution of these graphene sensors for the experimental solutions were 1.07Ω/ppm and 1ppm respectively. The developed system was validated by testing it with a real sample and cross checking it on the calibration curve. The signal conditioning circuit was further enhanced by embedding a microcontroller to the designed system. The obtained results did provide a platform for implementation of a low-cost salinity sensing system that could be used in marine applications.

Sensing System for Salinity Testing Using Laser-induced Graphene Sensors

KAUST Repository

Nag, Anindya; Mukhopadhyay, Subhas Chandra; Kosel, Jü rgen

2017-01-01

The paper presents the development and implementation of a low-cost salinity sensing system. Commercial polymer films were laser ablated at specific conditions to form graphene-based sensors on flexible Kapton substrates. Sodium chloride was considered as the primary constituent for testing due to its prominent presence in water bodies. The sensor was characterized by testing different concentrations of sodium chloride. A standard curve was developed to perform real-time testing with a sample taken from sea water of unknown concentration. The sensitivity and resolution of these graphene sensors for the experimental solutions were 1.07Ω/ppm and 1ppm respectively. The developed system was validated by testing it with a real sample and cross checking it on the calibration curve. The signal conditioning circuit was further enhanced by embedding a microcontroller to the designed system. The obtained results did provide a platform for implementation of a low-cost salinity sensing system that could be used in marine applications.

Comparative Study on a Solving Model and Algorithm for a Flush Air Data Sensing System

Directory of Open Access Journals (Sweden)

Yanbin Liu

2014-05-01

Full Text Available With the development of high-performance aircraft, precise air data are necessary to complete challenging tasks such as flight maneuvering with large angles of attack and high speed. As a result, the flush air data sensing system (FADS was developed to satisfy the stricter control demands. In this paper, comparative stuides on the solving model and algorithm for FADS are conducted. First, the basic principles of FADS are given to elucidate the nonlinear relations between the inputs and the outputs. Then, several different solving models and algorithms of FADS are provided to compute the air data, including the angle of attck, sideslip angle, dynamic pressure and static pressure. Afterwards, the evaluation criteria of the resulting models and algorithms are discussed to satisfy the real design demands. Futhermore, a simulation using these algorithms is performed to identify the properites of the distinct models and algorithms such as the measuring precision and real-time features. The advantages of these models and algorithms corresponding to the different flight conditions are also analyzed, furthermore, some suggestions on their engineering applications are proposed to help future research.

Self-Sensing Thermal Management System Using Multifunctional Nano-Enhanced Structures

Data.gov (United States)

National Aeronautics and Space Administration — The goal of this project is to develop a thermal management system with self-sensing capabilities using new multifunctional nano-enhanced structures. Currently,...

A system to control low pressure turbine temperatures

International Nuclear Information System (INIS)

1980-01-01

An improved system to control low pressure turbine cycle steam and metal temperatures by governing the heat transfer operation in a moisture separator-reheater is described. The use of the present invention in a pressurized water reactor or a boiling water reactor steam turbine system is demonstrated. (UK)

Pressure transducers

International Nuclear Information System (INIS)

Gomes, A.V.

1975-01-01

Strain gauges pressure transducers types are presented. Models, characteristics and calibration procedures were also analysed. Initially, a theoretical study was accomplished to evaluate metallic alloys behavior on sensing elements manufacturing, and diaphragm was used as deflecting elements. Electrical models for potenciometric transducers were proposed at the beginning and subsequently comproved according our experiments. Concerning bridge transducers, existing models confirmed the conditions of linearity and sensitivity related to the electrical signal. All the work done was of help on the calibration field and pressure measurements employing unbounded strain gauge pressure transducers

High-resolution dynamic pressure sensor array based on piezo-phototronic effect tuned photoluminescence imaging.

Science.gov (United States)

Peng, Mingzeng; Li, Zhou; Liu, Caihong; Zheng, Qiang; Shi, Xieqing; Song, Ming; Zhang, Yang; Du, Shiyu; Zhai, Junyi; Wang, Zhong Lin

2015-03-24

A high-resolution dynamic tactile/pressure display is indispensable to the comprehensive perception of force/mechanical stimulations such as electronic skin, biomechanical imaging/analysis, or personalized signatures. Here, we present a dynamic pressure sensor array based on pressure/strain tuned photoluminescence imaging without the need for electricity. Each sensor is a nanopillar that consists of InGaN/GaN multiple quantum wells. Its photoluminescence intensity can be modulated dramatically and linearly by small strain (0-0.15%) owing to the piezo-phototronic effect. The sensor array has a high pixel density of 6350 dpi and exceptional small standard deviation of photoluminescence. High-quality tactile/pressure sensing distribution can be real-time recorded by parallel photoluminescence imaging without any cross-talk. The sensor array can be inexpensively fabricated over large areas by semiconductor product lines. The proposed dynamic all-optical pressure imaging with excellent resolution, high sensitivity, good uniformity, and ultrafast response time offers a suitable way for smart sensing, micro/nano-opto-electromechanical systems.

Engine control system having pressure-based timing

Science.gov (United States)

Willi, Martin L [Dunlap, IL; Fiveland, Scott B [Metamora, IL; Montgomery, David T [Edelstein, IL; Gong, Weidong [Dunlap, IL

2011-10-04

A control system for an engine having a first cylinder and a second cylinder is disclosed having a first engine valve movable to regulate a fluid flow of the first cylinder and a first actuator associated with the first engine valve. The control system also has a second engine valve movable to regulate a fluid flow of the second cylinder and a sensor configured to generate a signal indicative of a pressure within the first cylinder. The control system also has a controller that is in communication with the first actuator and the sensor. The controller is configured to compare the pressure within the first cylinder with a desired pressure and selectively regulate the first actuator to adjust a timing of the first engine valve independently of the timing of the second engine valve based on the comparison.

Design and Analysis of a New Tuning Fork Structure for Resonant Pressure Sensor

Directory of Open Access Journals (Sweden)

Xiaodong Sun

2016-08-01

Full Text Available This paper presents a micromachined resonant pressure sensor. The sensor is designed to optimize the sensitivity and reduce the cross-talk between the driving electrodes and sensing electrodes. The relationship between the sensitivity of the sensor and the main design parameters is analyzed both theoretically and numerically. The sensing and driving electrodes are optimized to get both high sensing capacitance and low cross-talk. This sensor is fabricated using a micromachining process based on a silicon-on-insulator (SOI wafer. An open-loop measurement system and a closed-loop self-oscillation system is employed to measure the characteristics of the sensor. The experiment result shows that the sensor has a pressure sensitivity of about 29 Hz/kPa, a nonlinearity of 0.02%FS, a hysteresis error of 0.05%FS, and a repeatability error of 0.01%FS. The temperature coefficient is less than 2 Hz/°C in the range of −40 to 80 °C and the short-term stability of the sensor is better than 0.005%FS.

Energy Autonomous Wireless Sensing System Enabled by Energy Generated during Human Walking

Science.gov (United States)

Kuang, Yang; Ruan, Tingwen; Chew, Zheng Jun; Zhu, Meiling

2016-11-01

Recently, there has been a huge amount of work devoted to wearable energy harvesting (WEH) in a bid to establish energy autonomous wireless sensing systems for a range of health monitoring applications. However, limited work has been performed to implement and test such systems in real-world settings. This paper reports the development and real-world characterisation of a magnetically plucked wearable knee-joint energy harvester (Mag-WKEH) powered wireless sensing system, which integrates our latest research progresses in WEH, power conditioning and wireless sensing to achieve high energy efficiency. Experimental results demonstrate that with walking speeds of 3∼7 km/h, the Mag-WKEH generates average power of 1.9∼4.5 mW with unnoticeable impact on the wearer and is able to power the wireless sensor node (WSN) with three sensors to work at duty cycles of 6.6%∼13%. In each active period of 2 s, the WSN is able to measure and transmit 482 readings to the base station.

Methodology for surge pressure evaluation in a water injection system

Energy Technology Data Exchange (ETDEWEB)

Meliande, Patricia; Nascimento, Elson A. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Engenharia Civil; Mascarenhas, Flavio C.B. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Lab. de Hidraulica Computacional; Dandoulakis, Joao P. [SHELL of Brazil, Rio de Janeiro, RJ (Brazil)

2009-07-01

Predicting transient effects, known as surge pressures, is of high importance for offshore industry. It involves detailed computer modeling that attempts to simulate the complex interaction between flow line and fluid in order to ensure efficient system integrity. Platform process operators normally raise concerns whether the water injection system is adequately designed or not to be protected against possible surge pressures during sudden valve closure. This report aims to evaluate the surge pressures in Bijupira and Salema water injection systems due to valve closure, through a computer model simulation. Comparisons among the results from empirical formulations are discussed and supplementary analysis for Salema system were performed in order to define the maximum volumetric flow rate for which the design pressure was able to withstand. Maximum surge pressure values of 287.76 bar and 318.58 bar, obtained in Salema and Bijupira respectively, using empirical formulations have surpassed the operating pressure design, while the computer model results have pointed the greatest surge pressure value of 282 bar in Salema system. (author)

Induced topological pressure for topological dynamical systems

International Nuclear Information System (INIS)

Xing, Zhitao; Chen, Ercai

2015-01-01

In this paper, inspired by the article [J. Jaerisch et al., Stochastics Dyn. 14, 1350016, pp. 1-30 (2014)], we introduce the induced topological pressure for a topological dynamical system. In particular, we prove a variational principle for the induced topological pressure

PRINCIPLE OF VALIDATION OF MULTILEVEL RGB COLORIMETRIC SYSTEMS OF REMOTE SENSING

Directory of Open Access Journals (Sweden)

Lala Rustam Bekirova

2013-12-01

Full Text Available The possibility of development of two-level RGB colorimetric systems of remote sensing is analyzed. The principle of validation in multi-level RGB colorimetric systems taking into account the effect of metamerizm is formulated

Wearable Eating Habit Sensing System Using Internal Body Sound

Science.gov (United States)

Shuzo, Masaki; Komori, Shintaro; Takashima, Tomoko; Lopez, Guillaume; Tatsuta, Seiji; Yanagimoto, Shintaro; Warisawa, Shin'ichi; Delaunay, Jean-Jacques; Yamada, Ichiro

Continuous monitoring of eating habits could be useful in preventing lifestyle diseases such as metabolic syndrome. Conventional methods consist of self-reporting and calculating mastication frequency based on the myoelectric potential of the masseter muscle. Both these methods are significant burdens for the user. We developed a non-invasive, wearable sensing system that can record eating habits over a long period of time in daily life. Our sensing system is composed of two bone conduction microphones placed in the ears that send internal body sound data to a portable IC recorder. Applying frequency spectrum analysis on the collected sound data, we could not only count the number of mastications during eating, but also accurately differentiate between eating, drinking, and speaking activities. This information can be used to evaluate the regularity of meals. Moreover, we were able to analyze sound features to classify the types of foods eaten by food texture.

Parking Sensing and Information System: Sensors, Deployment, and Evaluation

OpenAIRE

Chen, Xiao; Zhen; Qian; Rajagopal, Ram; Stiers, Todd; Flores, Christopher; Kavaler, Robert; Williams III, Floyd

2017-01-01

This paper describes a smart parking sensing and information system that disseminates the parking availability information for public users in a cost-effective and efficient manner. The hardware framework of the system is built on advanced wireless sensor networks and cloud service over the Internet, and the system is highly scalable. The parking information provided to the users is set in the form of occupancy rates and expected cruising time. Both are obtained from our analytical algorithm ...

A Situated Cultural Festival Learning System Based on Motion Sensing

Science.gov (United States)

Chang, Yi-Hsing; Lin, Yu-Kai; Fang, Rong-Jyue; Lu, You-Te

2017-01-01

A situated Chinese cultural festival learning system based on motion sensing is developed in this study. The primary design principle is to create a highly interactive learning environment, allowing learners to interact with Kinect through natural gestures in the designed learning situation to achieve efficient learning. The system has the…

Remote sensing of vegetation fires and its contribution to a fire management information system

Science.gov (United States)

Stephane P. Flasse; Simon N. Trigg; Pietro N. Ceccato; Anita H. Perryman; Andrew T. Hudak; Mark W. Thompson; Bruce H. Brockett; Moussa Drame; Tim Ntabeni; Philip E. Frost; Tobias Landmann; Johan L. le Roux

2004-01-01

In the last decade, research has proven that remote sensing can provide very useful support to fire managers. This chapter provides an overview of the types of information remote sensing can provide to the fire community. First, it considers fire management information needs in the context of a fire management information system. An introduction to remote sensing then...

A system for incubations at high gas partial pressure

Directory of Open Access Journals (Sweden)

Patrick eSauer

2012-02-01

Full Text Available High-pressure is a key feature of deep subsurface environments. High partial pressure of dissolved gasses plays an important role in microbial metabolism, because thermodynamic feasibility of many reactions depends on the concentration of reactants. For gases, this is controlled by their partial pressure, which can exceed one MPa at in-situ conditions. Therefore, high hydrostatic pressure alone is not sufficient to recreate true deep subsurface in-situ conditions, but the partial pressure of dissolved gasses has to be controlled as well.We developed an incubation system that allows for incubations at hydrostatic pressure up to 60 MPa, temperatures up to 120° C and at high gas partial pressure. The composition and partial pressure of gasses can be manipulated during the experiment. The system is mainly made from off-the-shelf components with only very few custom-made parts. A flexible and inert PVDF incubator sleeve, which is almost impermeable for gases, holds the sample and separates it from the pressure fluid. The flexibility of the incubator sleeve allows for sub-sampling of the medium without loss of pressure. Experiments can be run in both static and flow through mode. The incubation system described here is usable for versatile purposes, not only the incubation of microorganisms and determination of growth rates, but also for chemical degradation or extraction experiments under high gas saturation, e.g. fluid-gas-rock-interactions in relation to carbon dioxide sequestration.As an application of the system we extracted organic acids from sub-bituminous coal using H2O as well as a H2O-CO2 mixture at elevated temperature (90°C and pressure (5 MPa. Subsamples were taken during the incubation and analysed by ion chromatography. Furthermore we demonstrated the applicability of the system for studies of microbial activity, using samples from the Isis mud volcano. We could detect an increase in sulphate reduction rate upon the addition of

Fiber-linked interferometric pressure sensor

Science.gov (United States)

Beheim, G.; Fritsch, K.; Poorman, R. N.

1987-01-01

A fiber-optic pressure sensor is described which uses a diaphragm to modulate the mirror separation of a Fabry-Perot cavity (the sensing cavity). A multimode optical fiber delivers broadband light to the sensing cavity and returns the spectrally modulated light which the cavity reflects. The sensor's output spectrum is analyzed using a tunable Fabry-Perot cavity (the reference cavity) to determine the mismatch in the mirror separations of the two cavities. An electronic servo control uses this result to cause the mirror separation of the reference cavity to equal that of the sensing cavity. The displacement of the pressure-sensing diaphragm is then obtained by measuring the capacitance of the reference cavity's metal-coated mirrors. Relative to other fiber-optic sensors, an important advantage of this instrument is its high immunity to the effects of variations in both the transmissivity of the fiber link and the wavelength of the optical source.

Hydrostatic pressure mimics gravitational pressure in characean cells

Science.gov (United States)

Staves, M. P.; Wayne, R.; Leopold, A. C.

1992-01-01

Hydrostatic pressure applied to one end of a horizontal Chara cell induces a polarity of cytoplasmic streaming, thus mimicking the effect of gravity. A positive hydrostatic pressure induces a more rapid streaming away from the applied pressure and a slower streaming toward the applied pressure. In contrast, a negative pressure induces a more rapid streaming toward and a slower streaming away from the applied pressure. Both the hydrostatic pressure-induced and gravity-induced polarity of cytoplasmic streaming respond identically to cell ligation, UV microbeam irradiation, external Ca2+ concentrations, osmotic pressure, neutral red, TEA Cl-, and the Ca2+ channel blockers nifedipine and LaCl3. In addition, hydrostatic pressure applied to the bottom of a vertically-oriented cell can abolish and even reverse the gravity-induced polarity of cytoplasmic streaming. These data indicate that both gravity and hydrostatic pressure act at the same point of the signal transduction chain leading to the induction of a polarity of cytoplasmic streaming and support the hypothesis that characean cells respond to gravity by sensing a gravity-induced pressure differential between the cell ends.

Effect of oxygen partial pressure on the microstructural, optical and gas sensing characterization of nanostructured Gd doped ceria thin films deposited by pulsed laser deposition

Directory of Open Access Journals (Sweden)

Nagaraju P.

2017-12-01

Full Text Available Microstructural properties of 10 mol% gadolinium doped ceria (CeO2 thin films that were deposited on quartz substrate at substrate temperature of 1023 K by using pulsed laser deposition with different oxygen partial pressures in the range of 50–200 mTorr. The influence of oxygen partial pressure on microstructural, morphological, optical and gas sensing characterization of the thin films was systematically studied. The microstructure of the thin films was investigated using X-ray diffraction, atomic force microscopy and Raman spectroscopy. Morphological studies have been carried out using scanning electron microscope. The experimental results confirmed that the films were polycrystalline in nature with cubic fluorite structure. Optical properties of the thin films were examined using UV–vis spectrophotometer. The optical band gap calculated from Tauc’s relation. Gas sensing characterization has been carried at different operating temperatures (room temperature to 523 K for acetone gas. Response and recovery times of the sensor were calculated using transient response plot.

Benchtop evaluation of pressure barrier insufflator and standard insufflator systems.

Science.gov (United States)

Nepple, Kenneth G; Kallogjeri, Dorina; Bhayani, Sam B

2013-01-01

Previous experimental research has reported minimal differences in pressure maintenance between different versions of standard insufflators (SI). However, a recent report identified potential clinical benefits with a valveless pressure barrier insufflator (PBI). We sought to perform a benchtop objective evaluation of SI and PBI systems. A rigid box system with continuous pressure manometry was used to evaluate a PBI (Surgiquest Airseal) and two SIs (SI1 = Stryker PneumoSure High Flow Insufflator and SI2 = Storz SCB Thermoflator). Pressure maintenance of 15 mmHg was evaluated during experimental conditions of leakage from a 5 mm port site, leakage from a 12 mm port site, and continuous suction. With leakage from the 5 mm port site, the PBI maintained pressure of >13 mmHg whereas the pressures dropped moderately with the SI1 (7-13 mmHg) and SI2 insufflators (3-7 mmHg) and did not regain goal pressure until leakage was stopped. With leakage from 12 mm port site, the PBI pressure decreased to 9-11 mmHg, whereas the SI1 and SI2 lost insufflation pressures completely. The PBI maintained pressure of >11 mmHg during continuous suction while the SI1 and SI2 lost pressure entirely, and actually showed negative pressure from air suction into the rigid box system. When evaluated statistically with the mixed model repeated measures ANOVA, the SI1 and SI2 performed similarly while the PBI maintained increased pressure. In the experimental rigid box system, the PBI more successfully maintained pressure in response to leakage and suction than SIs.

A Computer Controlled Precision High Pressure Measuring System

Science.gov (United States)

Sadana, S.; Yadav, S.; Jha, N.; Gupta, V. K.; Agarwal, R.; Bandyopadhyay, A. K.; Saxena, T. K.

2011-01-01

A microcontroller (AT89C51) based electronics has been designed and developed for high precision calibrator based on Digiquartz pressure transducer (DQPT) for the measurement of high hydrostatic pressure up to 275 MPa. The input signal from DQPT is converted into a square wave form and multiplied through frequency multiplier circuit over 10 times to input frequency. This input frequency is multiplied by a factor of ten using phased lock loop. Octal buffer is used to store the calculated frequency, which in turn is fed to microcontroller AT89C51 interfaced with a liquid crystal display for the display of frequency as well as corresponding pressure in user friendly units. The electronics developed is interfaced with a computer using RS232 for automatic data acquisition, computation and storage. The data is acquired by programming in Visual Basic 6.0. This system is interfaced with the PC to make it a computer controlled system. The system is capable of measuring the frequency up to 4 MHz with a resolution of 0.01 Hz and the pressure up to 275 MPa with a resolution of 0.001 MPa within measurement uncertainty of 0.025%. The details on the hardware of the pressure measuring system, associated electronics, software and calibration are discussed in this paper.

Collaboratively Adaptive Vibration Sensing System for High-fidelity Monitoring of Structural Responses Induced by Pedestrians

Directory of Open Access Journals (Sweden)

Shijia Pan

2017-05-01

Full Text Available This paper presents a collaboratively adaptive vibration monitoring system that captures high-fidelity structural vibration signals induced by pedestrians. These signals can be used for various human activities’ monitoring by inferring information about the impact sources, such as pedestrian footsteps, door opening and closing, and dragging objects. Such applications often require high-fidelity (high resolution and low distortion signals. Traditionally, expensive high resolution and high dynamic range sensors are adopted to ensure sufficient resolution. However, for sensing systems that use low-cost sensing devices, the resolution and dynamic range are often limited; hence this type of sensing methods is not well explored ubiquitously. We propose a low-cost sensing system that utilizes (1 a heuristic model of the investigating excitations and (2 shared information through networked devices to adapt hardware configurations and obtain high-fidelity structural vibration signals. To further explain the system, we use indoor pedestrian footstep sensing through ambient structural vibration as an example to demonstrate the system performance. We evaluate the application with three metrics that measure the signal quality from different aspects: the sufficient resolution rate to present signal resolution improvement without clipping, the clipping rate to measure the distortion of the footstep signal, and the signal magnitude to quantify the detailed resolution of the detected footstep signal. In experiments conducted in a school building, our system demonstrated up to 2× increase on the sufficient resolution rate and 2× less error rate when used to locate the pedestrians as they walk along the hallway, compared to a fixed sensing setting.

A high spatial resolution distributed optical fiber grating sensing system based on OFDR

Science.gov (United States)

Dong, Ke; Xiong, Yuchuan; Wen, Hongqiao; Tong, Xinlin; Zhang, Cui; Deng, Chengwei

2017-10-01

A distributed optical fiber grating sensing system with large capacity and high spatial resolution is presented. Since highdensity identical weak grating array was utilized as sensing fiber, the multiplexing number was greatly increased, meanwhile, optical frequency domain reflectometry (OFDR) technology was used to implement high resolution distributed sensing system. In order to eliminate the nonlinear effect of tunable light source, a windowed FFT algorithm based on cubic spline interpolation was applied. The feasibility of the algorithm was experimentally testified, ultimately, the spatial resolution of system can reach mm-level. The influence of the crosstalk signal in the grating array on the OFDR system was analyzed. A method that a long enough delay fiber was added before the first FBG to remove crosstalk signal was proposed. The experiment was verified using an optical fiber with 113 uniform Bragg gratings at an interval of 10cm whose reflectivity are less than 1%. It demonstrates that crosstalk signal and measurement signal can be completely separated in the distance domain after adding a long enough delay fiber. Finally, the temperature experiment of distributed grating sensing system was carried out. The results display that each raster's center wavelength in the fiber link is independent of each other and the center wavelength drift has a good linear relationship with the temperature. The sensitivity of linear fitting is equal to 11.1pm/°C.

An Energy Efficient Cognitive Radio System with Quantized Soft Sensing and Duration Analysis

KAUST Repository

Alabbasi, Abdulrahman

2015-03-09

In this paper, an energy efficient cognitive radio system is proposed. The proposed design optimizes the secondary user transmission power and the sensing duration combined with soft-sensing information to minimize the energy per goodbit. Due to the non-convex nature of the problem we prove its pseudo-convexity to guarantee the optimal solution. Furthermore, a quantization scheme, that discretize the softsensing information, is proposed and analyzed to reduce the overload of the continuously adapted power. Numerical results show that our proposed system outperforms the benchmark systems. The impact of the quantization levels and other system parameters is evaluated in the numerical results.

Sensor and methods of detecting target materials and situations in closed systems

Energy Technology Data Exchange (ETDEWEB)

Mee, David K.; Ripley, Edward B.; Nienstedt, Zachary C.; Nienstedt, Alex W.; Howell, Jr., Layton N.

2018-03-13

Disclosed is a passive, in-situ pressure sensor. The sensor includes a sensing element having a ferromagnetic metal and a tension inducing mechanism coupled to the ferromagnetic metal. The tension inducing mechanism is operable to change a tensile stress upon the ferromagnetic metal based on a change in pressure in the sensing element. Changes in pressure are detected based on changes in the magnetic switching characteristics of the ferromagnetic metal when subjected to an alternating magnetic field caused by the change in the tensile stress. The sensing element is embeddable in a closed system for detecting pressure changes without the need for any penetrations of the system for power or data acquisition by detecting changes in the magnetic switching characteristics of the ferromagnetic metal caused by the tensile stress.

Cryogenic, Absolute, High Pressure Sensor

Science.gov (United States)

Chapman, John J. (Inventor); Shams. Qamar A. (Inventor); Powers, William T. (Inventor)

2001-01-01

A pressure sensor is provided for cryogenic, high pressure applications. A highly doped silicon piezoresistive pressure sensor is bonded to a silicon substrate in an absolute pressure sensing configuration. The absolute pressure sensor is bonded to an aluminum nitride substrate. Aluminum nitride has appropriate coefficient of thermal expansion for use with highly doped silicon at cryogenic temperatures. A group of sensors, either two sensors on two substrates or four sensors on a single substrate are packaged in a pressure vessel.

Cryogenic High Pressure Sensor Module

Science.gov (United States)

Chapman, John J. (Inventor); Shams, Qamar A. (Inventor); Powers, William T. (Inventor)

1999-01-01

A pressure sensor is provided for cryogenic, high pressure applications. A highly doped silicon piezoresistive pressure sensor is bonded to a silicon substrate in an absolute pressure sensing configuration. The absolute pressure sensor is bonded to an aluminum nitride substrate. Aluminum nitride has appropriate coefficient of thermal expansion for use with highly doped silicon at cryogenic temperatures. A group of sensors, either two sensors on two substrates or four sensors on a single substrate are packaged in a pressure vessel.

Integrating remote sensing, geographic information systems and global positioning system techniques with hydrological modeling

Science.gov (United States)

Thakur, Jay Krishna; Singh, Sudhir Kumar; Ekanthalu, Vicky Shettigondahalli

2017-07-01

Integration of remote sensing (RS), geographic information systems (GIS) and global positioning system (GPS) are emerging research areas in the field of groundwater hydrology, resource management, environmental monitoring and during emergency response. Recent advancements in the fields of RS, GIS, GPS and higher level of computation will help in providing and handling a range of data simultaneously in a time- and cost-efficient manner. This review paper deals with hydrological modeling, uses of remote sensing and GIS in hydrological modeling, models of integrations and their need and in last the conclusion. After dealing with these issues conceptually and technically, we can develop better methods and novel approaches to handle large data sets and in a better way to communicate information related with rapidly decreasing societal resources, i.e. groundwater.

Functional systems of a pressurized water reactor

International Nuclear Information System (INIS)

Heinzel, V.

1982-01-01

The main topics, discussed in the present paper, are: - Principle design of the reactor coolant system - reactor pressure vessel with internals - containment design - residual heat removal and emergency cooling systems - nuclear component cooling systems - emergency feed water systems - plant electric power supply system. (orig./RW)

Optimal Remote Sensing with Small Unmanned Aircraft Systems and Risk Management

Science.gov (United States)

Stark, Brandon

Over the past decade, the rapid rise of Unmanned Aircraft Systems (UASs) has blossomed into a new component of the aviation industry. Though regulations within the United States lagged, the promise of the ability of Small Unmanned Aircraft Systems (SUASs), or those UAS that weigh less than 55 lbs, has driven significant advances in small scale aviation technology. The dream of a small, low-cost aerial platform that can fly anywhere and keep humans safely away from the `dull, dangerous and dirty' jobs, has encouraged many to examine the possibilities of utilizing SUAS in new and transformative ways, especially as a new tool in remote sensing. However, as with any new tool, there remains significant challenges in realizing the full potential of SUAS-based remote sensing. Within this dissertation, two specific challenges are addressed: validating the use of SUAS as a remote sensing platform and improving the safety and management of SUAS. The use of SUAS in remote sensing is a relatively new challenge and while it has many similarities to other remote sensing platforms, the dynamic nature of its operation makes it unique. In this dissertation, a closer look at the methodology of using SUAS reveals that while many view SUAS as an alternative to satellite imagery, this is an incomplete view and that the current common implementation introduces a new source of error that has significant implications on the reliability of the data collected. It can also be seen that a new approach to remote sensing with an SUAS can be developed by addressing the spatial, spectral and temporal factors that can now be more finely adjusted with the use of SUAS. However, to take the full advantage of the potential of SUAS, they must uphold the promise of improved safety. This is not a trivial challenge, especially for the integration into the National Airspace System (NAS) and for the safety management and oversight of diverse UAS operations. In this dissertation, the challenge of integrating

Low pressure cooling seal system for a gas turbine engine

Science.gov (United States)

Marra, John J

2014-04-01

A low pressure cooling system for a turbine engine for directing cooling fluids at low pressure, such as at ambient pressure, through at least one cooling fluid supply channel and into a cooling fluid mixing chamber positioned immediately downstream from a row of turbine blades extending radially outward from a rotor assembly to prevent ingestion of hot gases into internal aspects of the rotor assembly. The low pressure cooling system may also include at least one bleed channel that may extend through the rotor assembly and exhaust cooling fluids into the cooling fluid mixing chamber to seal a gap between rotational turbine blades and a downstream, stationary turbine component. Use of ambient pressure cooling fluids by the low pressure cooling system results in tremendous efficiencies by eliminating the need for pressurized cooling fluids for sealing this gap.

Corn silk aqueous extracts and intraocular pressure of systemic and non-systemic hypertensive subjects.

Science.gov (United States)

George, Gladys O; Idu, Faustina K

2015-03-01

Hypotensive properties have been attributed to the stigma/style of Zea mays L (corn silk). Although the effect of corn silk extract on blood pressure has been documented in animal studies, we are not aware of any study on its effect on human blood pressure and intraocular pressure. A randomised study was carried out on the effect of water only, masked doses of corn silk aqueous extract (60, 130, 192.5 and 260 mg/kg body weight) on intraocular pressure and blood pressure of 20 systemic and 20 non-systemic hypertensive subjects. Intraocular pressure and blood pressure were measured at baseline and every hour for eight hours after administering water or a masked dose of corn silk aqueous extract. Each dose was administered at two-week intervals to each subject in the two study groups. The results showed that the last three doses of corn silk aqueous extract gave a statistically significant reduction (p Corn silk aqueous extract has a lowering effect on intraocular pressure in systemic and non-systemic hypertensive subjects. This may have resulted from the fall in blood pressure that is due to potassium-induced natriuresis and diuresis caused by the high potassium content in the high doses of the corn silk extract. © 2015 The Authors. Clinical and Experimental Optometry © 2015 Optometry Australia.

Mechanics of localized slippage in tactile sensing and application to soft sensing systems

CERN Document Server

Ho, Anh-Van

2014-01-01

Localized slippage occurs during any relative sliding of soft contacts, ranging from human fingertips to robotic fingertips. Although this phenomenon is dominant for a very short time prior to gross slippage, localized slippage is a crucial factor for any to-be-developed soft sensing system to respond to slippage before it occurs. The content of this book addresses all aspects of localized slippage, including modeling and simulating it, as well as applying it to the construction of novel sensors with slip tactile perception.

A Flexible and Highly Sensitive Piezoresistive Pressure Sensor Based on Micropatterned Films Coated with Carbon Nanotubes

Directory of Open Access Journals (Sweden)

Jia-lin Yao

2016-01-01

Full Text Available Excellent flexibility, high sensitivity, and low consumption are essential characteristics in flexible microtube pressure sensing occasion, for example, implantable medical devices, industrial pipeline, and microfluidic chip. This paper reports a flexible, highly sensitive, and ultrathin piezoresistive pressure sensor for fluid pressure sensing, whose sensing element is micropatterned films with conductive carbon nanotube layer. The flexible pressure sensor, the thickness of which is 40 ± 10 μm, could be economically fabricated by using biocompatible polydimethylsiloxane (PDMS. Experimental results show that the flexible pressure sensor has high sensitivity (0.047 kPa−1 in gas sensing and 5.6 × 10−3 kPa−1 in liquid sensing and low consumption (<180 μW, and the sensor could be used to measure the pressure in curved microtubes.

Development of a versatile intra-articular pressure sensing array.

Science.gov (United States)

Welcher, J B; Popovich, J M; Hedman, T P

2011-10-01

A new sensor array intended to accurately and directly measure spatial and time-dependent pressures within a highly curved biological intra-articular joint was developed and tested. To evaluate performance of the new sensor array for application within intra-articular joints generally, and specifically to fit within the relatively restrictive space of the lumbar spine facet joint, geometric constraints of length, width, thickness and sensor spatial resolution were evaluated. Additionally, the effects of sensor array curvature, frequency response, linearity, drift, hysteresis, repeatability, and total system cost were assessed. The new sensor array was approximately 0.6mm in thickness, scalable to below the nominal 12 mm wide by 15 high lumbar spine facet joint size, offered no inherent limitations on the number or spacing of the sensors with less than 1.7% cross talk with sensor immediately adjacent to one another. No difference was observed in sensor performance down to a radius of curvature of 7 mm and a 0.66±0.97% change in sensor sensitivity was observed at a radius of 5.5mm. The sensor array had less than 0.07 dB signal loss up to 5.5 Hz, linearity was 0.58±0.13% full scale (FS), drift was less than 0.2% FS at 250 s and less than 0.6% FS at 700 s, hysteresis was 0.78±0.18%. Repeatability was excellent with a coefficient of variation less than 2% at pressures between 0 and 1.000 MPa. Total system cost was relatively small as standard commercially available data acquisition systems could be utilized, with no specialized software, and individual sensors within an array can be replaced as needed. The new sensor array had small and scalable geometry and very acceptable intrinsic performance including minimal to no alteration in performance at physiologically relevant ranges of joint curvature. Copyright © 2011 IPEM. Published by Elsevier Ltd. All rights reserved.

Geographic information systems, remote sensing, and spatial analysis activities in Texas, 2002-07

Science.gov (United States)

Pearson, D.K.; Gary, R.H.; Wilson, Z.D.

2007-01-01

Geographic information system (GIS) technology has become an important tool for scientific investigation, resource management, and environmental planning. A GIS is a computer-aided system capable of collecting, storing, analyzing, and displaying spatially referenced digital data. GIS technology is particularly useful when analyzing a wide variety of spatial data such as with remote sensing and spatial analysis. Remote sensing involves collecting remotely sensed data, such as satellite imagery, aerial photography, or radar images, and analyzing the data to gather information or investigate trends about the environment or the Earth's surface. Spatial analysis combines remotely sensed, thematic, statistical, quantitative, and geographical data through overlay, modeling, and other analytical techniques to investigate specific research questions. It is the combination of data formats and analysis techniques that has made GIS an essential tool in scientific investigations. This document presents information about the technical capabilities and project activities of the U.S. Geological Survey (USGS) Texas Water Science Center (TWSC) GIS Workgroup from 2002 through 2007.

A knitted glove sensing system with compression strain for finger movements

Science.gov (United States)

Ryu, Hochung; Park, Sangki; Park, Jong-Jin; Bae, Jihyun

2018-05-01

Development of a fabric structure strain sensor has received considerable attention due to its broad application in healthcare monitoring and human–machine interfaces. In the knitted textile structure, it is critical to understand the surface structural deformation from a different body motion, inducing the electrical signal characteristics. Here, we report the electromechanical properties of the knitted glove sensing system focusing on the compressive strain behavior. Compared with the electrical response of the tensile strain, the compressive strain shows much higher sensitivity, stability, and linearity via different finger motions. Additionally, the sensor exhibits constant electrical properties after repeated cyclic tests and washing processes. The proposed knitted glove sensing system can be readily extended to a scalable and cost-effective production due to the use of a commercialized manufacturing system.

Advanced Fiber Optic-Based Sensing Technology for Unmanned Aircraft Systems

Science.gov (United States)

Richards, Lance; Parker, Allen R.; Piazza, Anthony; Ko, William L.; Chan, Patrick; Bakalyar, John

2011-01-01

This presentation provides an overview of fiber optic sensing technology development activities performed at NASA Dryden in support of Unmanned Aircraft Systems. Examples of current and previous work are presented in the following categories: algorithm development, system development, instrumentation installation, ground R&D, and flight testing. Examples of current research and development activities are provided.

Making Sense of Alternative Assessment in a Qualitative Evaluation System

Science.gov (United States)

Rojas Serrano, Javier

2017-01-01

In a Colombian private English institution, a qualitative evaluation system has been incorporated. This type of evaluation poses challenges to students who have never been evaluated through a system that eliminates exams or quizzes and, as a consequence, these students have to start making sense of it. This study explores the way students face the…

Characteristics of pressure control system on PWR/PHWR in pile loop facility

International Nuclear Information System (INIS)

Sarwani; Hendro, P.; Suwoto; Sutrisno

1998-01-01

PWR/PHWR in-pile loop facility is used for testing of fuel element bundle which is correspond to the condition of power reactor operation. So, this facility is designed at 150 bar of pressure and 350 o C of temperature. Pressure control system is one of the components of the facility and it is equipped with 6 electrical heaters (30 KW), water spray, pressure and temperature monitors. The characterization test of pressure control system has been carried out with operating of 2 electrical heaters (10 KW). The K eff calculation value is different 5.2% from pressure in the pressure control system can be increased to 160 bar within 27 hours. After the system pressure reached the nominal pressure, the pressure control system was in the steady state condition

Atmospheric pressure microwave plasma system with ring waveguide

International Nuclear Information System (INIS)

Liu Liang; Zhang Guixin; Zhu Zhijie; Luo Chengmu

2007-01-01

Some scientists used waveguide as the cavity to produce a plasma jet, while large volume microwave plasma was relatively hard to get in atmospheric pressure. However, a few research institutes have already developed devices to generate large volume of atmospheric pressure microwave plasma, such as CYRANNUS and SLAN series, which can be widely applied. In this paper, present a microwave plasma system with ring waveguide to excite large volume of atmospheric pressure microwave plasma, plot curves on theoretical disruption electric field of some working gases, emulate the cavity through software, measure the power density to validate and show the appearance of microwave plasma. At present, large volume of argon and helium plasma have already been generated steadily by atmospheric pressure microwave plasma system. This research can build a theoretical basis of microwave plasma excitation under atmospheric pressure and will be useful in study of the device. (authors)

[Development of a continuous blood pressure monitoring and recording system].

Science.gov (United States)

Zhang, Yang; Li, Yong; Gao, Shumei; Song, Yilin

2012-09-01

A small experimental system is constructed with working principle of continuous blood pressure monitoring based on the volume compensation method. The preliminary experimental results show that the system can collect blood pressure signals at the radial artery effectively. The digital PID algorithm can track the variation of blood pressure. And the accuracy of continuous blood pressure detecting achieve the level of same kind of product.

Integration of piezo-capacitive and piezo-electric nanoweb based pressure sensors for imaging of static and dynamic pressure distribution.

Science.gov (United States)

Jeong, Y J; Oh, T I; Woo, E J; Kim, K J

2017-07-01

Recently, highly flexible and soft pressure distribution imaging sensor is in great demand for tactile sensing, gait analysis, ubiquitous life-care based on activity recognition, and therapeutics. In this study, we integrate the piezo-capacitive and piezo-electric nanowebs with the conductive fabric sheets for detecting static and dynamic pressure distributions on a large sensing area. Electrical impedance tomography (EIT) and electric source imaging are applied for reconstructing pressure distribution images from measured current-voltage data on the boundary of the hybrid fabric sensor. We evaluated the piezo-capacitive nanoweb sensor, piezo-electric nanoweb sensor, and hybrid fabric sensor. The results show the feasibility of static and dynamic pressure distribution imaging from the boundary measurements of the fabric sensors.

Crowd Sensing-Enabling Security Service Recommendation for Social Fog Computing Systems.

Science.gov (United States)

Wu, Jun; Su, Zhou; Wang, Shen; Li, Jianhua

2017-07-30

Fog computing, shifting intelligence and resources from the remote cloud to edge networks, has the potential of providing low-latency for the communication from sensing data sources to users. For the objects from the Internet of Things (IoT) to the cloud, it is a new trend that the objects establish social-like relationships with each other, which efficiently brings the benefits of developed sociality to a complex environment. As fog service become more sophisticated, it will become more convenient for fog users to share their own services, resources, and data via social networks. Meanwhile, the efficient social organization can enable more flexible, secure, and collaborative networking. Aforementioned advantages make the social network a potential architecture for fog computing systems. In this paper, we design an architecture for social fog computing, in which the services of fog are provisioned based on "friend" relationships. To the best of our knowledge, this is the first attempt at an organized fog computing system-based social model. Meanwhile, social networking enhances the complexity and security risks of fog computing services, creating difficulties of security service recommendations in social fog computing. To address this, we propose a novel crowd sensing-enabling security service provisioning method to recommend security services accurately in social fog computing systems. Simulation results show the feasibilities and efficiency of the crowd sensing-enabling security service recommendation method for social fog computing systems.

Pressure Fluctuations in a Common-Rail Fuel Injection System

Science.gov (United States)

Rothrock, A M

1931-01-01

This report presents the results of an investigation to determine experimentally the instantaneous pressures at the discharge orifice of a common-rail fuel injection system in which the timing valve and cut-off valve were at some distance from the automatic fuel injection valve, and also to determine the methods by which the pressure fluctuations could be controlled. The results show that pressure wave phenomena occur between the high-pressure reservoir and the discharge orifice, but that these pressure waves can be controlled so as to be advantageous to the injection of the fuel. The results also give data applicable to the design of such an injection system for a high-speed compression-ignition engine.

14 CFR 25.1325 - Static pressure systems.

Science.gov (United States)

2010-01-01

... installation of the static pressure system must be such that— (1) Positive drainage of moisture is provided..., the other is blocked off; and (2) Both sources cannot be blocked off simultaneously. (h) For... other static pressure source being open or blocked. [Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as...

A microfluidic circulatory system integrated with capillary-assisted pressure sensors.

Science.gov (United States)

Chen, Yangfan; Chan, Ho Nam; Michael, Sean A; Shen, Yusheng; Chen, Yin; Tian, Qian; Huang, Lu; Wu, Hongkai

2017-02-14

The human circulatory system comprises a complex network of blood vessels interconnecting biologically relevant organs and a heart driving blood recirculation throughout this system. Recreating this system in vitro would act as a bridge between organ-on-a-chip and "body-on-a-chip" and advance the development of in vitro models. Here, we present a microfluidic circulatory system integrated with an on-chip pressure sensor to closely mimic human systemic circulation in vitro. A cardiac-like on-chip pumping system is incorporated in the device. It consists of four pumping units and passive check valves, which mimic the four heart chambers and heart valves, respectively. Each pumping unit is independently controlled with adjustable pressure and pump rate, enabling users to control the mimicked blood pressure and heartbeat rate within the device. A check valve is located downstream of each pumping unit to prevent backward leakage. Pulsatile and unidirectional flow can be generated to recirculate within the device by programming the four pumping units. We also report an on-chip capillary-assisted pressure sensor to monitor the pressure inside the device. One end of the capillary was placed in the measurement region, while the other end was sealed. Time-dependent pressure changes were measured by recording the movement of the liquid-gas interface in the capillary and calculating the pressure using the ideal gas law. The sensor covered the physiologically relevant blood pressure range found in humans (0-142.5 mmHg) and could respond to 0.2 s actuation time. With the aid of the sensor, the pressure inside the device could be adjusted to the desired range. As a proof of concept, human normal left ventricular and arterial pressure profiles were mimicked inside this device. Human umbilical vein endothelial cells (HUVECs) were cultured on chip and cells can respond to mechanical forces generated by arterial-like flow patterns.

A Review on Applications of Remote Sensing and Geographic Information Systems (GIS in Water Resources and Flood Risk Management

Directory of Open Access Journals (Sweden)

Xianwei Wang

2018-05-01

Full Text Available Water is one of the most critical natural resources that maintain the ecosystem and support people’s daily life. Pressures on water resources and disaster management are rising primarily due to the unequal spatial and temporal distribution of water resources and pollution, and also partially due to our poor knowledge about the distribution of water resources and poor management of their usage. Remote sensing provides critical data for mapping water resources, measuring hydrological fluxes, monitoring drought and flooding inundation, while geographic information systems (GIS provide the best tools for water resources, drought and flood risk management. This special issue presents the best practices, cutting-edge technologies and applications of remote sensing, GIS and hydrological models for water resource mapping, satellite rainfall measurements, runoff simulation, water body and flood inundation mapping, and risk management. The latest technologies applied include 3D surface model analysis and visualization of glaciers, unmanned aerial vehicle (UAV video image classification for turfgrass mapping and irrigation planning, ground penetration radar for soil moisture estimation, the Tropical Rainfall Measuring Mission (TRMM and the Global Precipitation Measurement (GPM satellite rainfall measurements, storm hyetography analysis, rainfall runoff and urban flooding simulation, and satellite radar and optical image classification for urban water bodies and flooding inundation. The application of those technologies is expected to greatly relieve the pressures on water resources and allow better mitigation of and adaptation to the disastrous impact of droughts and flooding.

Energy Autonomous Wireless Sensing System Enabled by Energy Generated during Human Walking

International Nuclear Information System (INIS)

Kuang, Yang; Ruan, Tingwen; Chew, Zheng Jun; Zhu, Meiling

2016-01-01

Recently, there has been a huge amount of work devoted to wearable energy harvesting (WEH) in a bid to establish energy autonomous wireless sensing systems for a range of health monitoring applications. However, limited work has been performed to implement and test such systems in real-world settings. This paper reports the development and real-world characterisation of a magnetically plucked wearable knee-joint energy harvester (Mag-WKEH) powered wireless sensing system, which integrates our latest research progresses in WEH, power conditioning and wireless sensing to achieve high energy efficiency. Experimental results demonstrate that with walking speeds of 3∼7 km/h, the Mag-WKEH generates average power of 1.9∼4.5 mW with unnoticeable impact on the wearer and is able to power the wireless sensor node (WSN) with three sensors to work at duty cycles of 6.6%∼13%. In each active period of 2 s, the WSN is able to measure and transmit 482 readings to the base station. (paper)

Energy-Recovery Pressure-Reducer in District Heating System

Directory of Open Access Journals (Sweden)

Dariusz Borkowski

2018-06-01

Full Text Available Already existing man-made infrastructures that create water flow and unused pressure are interesting energy sources to which micro-hydropower plants can be applied. Apart from water supply systems (WSSs, which are widely described in the literature, significant hydropower potential can also be found in district heating systems (DHSs. In this paper, a prototype, a so-called energy-recovery pressure-reducer (ERPR, utilized for a DHS, is presented. It consisted of a pump as a turbine coupled to a permanent magnet synchronous generator (PMSG. The latter was connected to the power grid through the power electronic unit (PEU. The variable-speed operation allowed one to modify the turbine characteristics to match the substation’s hydraulic conditions. The proposed ERPR device could be installed in series to the existing classic pressure reducing valve (PRV as an independent device that reduces costs and simplifies system installation. The test results of the prototype system located in a substation of Cracow’s DHS are presented. The steady-state curves and regulation characteristics show the prototype’s operating range and efficiency. In this study, the pressure-reducer impact on the electrical and hydraulic systems, and on the environment, were analyzed. The operation tests during the annual heating season revealed an average system’s efficiency of 49%.

Hyperelastic pressure sensing with a liquid-embedded elastomer

International Nuclear Information System (INIS)

Park, Yong-Lae; Wood, Robert J; Majidi, Carmel; Kramer, Rebecca; Bérard, Phillipe

2010-01-01

A hyperelastic pressure transducer is fabricated by embedding silicone rubber with microchannels of conductive liquid eutectic gallium–indium. Pressing the surface of the elastomer with pressures in the range of 0–100 kPa will deform the cross-section of underlying channels and change their electric resistance by as much as 50%. Microchannels with dimensions as small as 25 µm are obtained with a maskless, soft lithography process that utilizes direct laser exposure. Change in electrical resistance is measured as a function of the magnitude and area of the surface pressure as well as the cross-sectional geometry, depth and relative lateral position of the embedded channel. These experimentally measured values closely match closed-form theoretical predictions derived from plane strain elasticity and contact mechanics

Determinants of systemic zero-flow arterial pressure.

Science.gov (United States)

Brunner, M J; Greene, A S; Sagawa, K; Shoukas, A A

1983-09-01

Thirteen pentobarbital-anesthetized dogs whose carotid sinuses were isolated and perfused at a constant pressure were placed on total cardiac bypass. With systemic venous pressure held at 0 mmHg (condition 1), arterial inflow was stopped for 20 s at intrasinus pressures of 50, 125, and 200 mmHg. Zero-flow arterial pressures under condition 1 were 16.2 +/- 1.3 (SE), 13.8 +/- 1.1, and 12.5 +/- 0.8 mmHg, respectively. In condition 2, the venous outflow tube was clamped at the instant of stopping the inflow, causing venous pressure to rise. The zero-flow arterial pressures were 19.7 +/- 1.3, 18.5 +/- 1.4, and 16.4 +/- 1.2 mmHg for intrasinus pressures of 50, 125, and 200 mmHg, respectively. At all levels of intrasinus pressure, the zero-flow arterial pressure in condition 2 was higher (P less than 0.005) than in condition 1. In seven dogs, at an intrasinus pressure of 125 mmHg, epinephrine increased the zero-flow arterial pressure by 3.0 mmHg, whereas hexamethonium and papaverine decreased the zero-flow arterial pressure by 2 mmHg. Reductions in the hematocrit from 52 to 11% resulted in statistically significant changes (P less than 0.01) in zero-flow arterial pressures. Thus zero-flow arterial pressure was found to be affected by changes in venous pressure, hematocrit, and vasomotor tone. The evidence does not support the literally interpreted concept of the vascular waterfall as the model for the finite arteriovenous pressure difference at zero flow.

Rapid deployable global sensing hazard alert system

Science.gov (United States)

Cordaro, Joseph V; Tibrea, Steven L; Shull, Davis J; Coleman, Jerry T; Shuler, James M

2015-04-28

A rapid deployable global sensing hazard alert system and associated methods of operation are provided. An exemplary system includes a central command, a wireless backhaul network, and a remote monitoring unit. The remote monitoring unit can include a positioning system configured to determine a position of the remote monitoring unit based on one or more signals received from one or more satellites located in Low Earth Orbit. The wireless backhaul network can provide bidirectional communication capability independent of cellular telecommunication networks and the Internet. An exemplary method includes instructing at least one of a plurality of remote monitoring units to provide an alert based at least in part on a location of a hazard and a plurality of positions respectively associated with the plurality of remote monitoring units.

DNA-Enabled Integrated Molecular Systems for Computation and Sensing

Science.gov (United States)

2014-05-21

Computational devices can be chemically conjugated to different strands of DNA that are then self-assembled according to strict Watson − Crick binding rules... DNA -Enabled Integrated Molecular Systems for Computation and Sensing Craig LaBoda,† Heather Duschl,† and Chris L. Dwyer*,†,‡ †Department of...guided folding of DNA , inspired by nature, allows designs to manipulate molecular-scale processes unlike any other material system. Thus, DNA can be

Plant-Derived Natural Products as Sources of Anti-Quorum Sensing Compounds

Directory of Open Access Journals (Sweden)

Kok-Gan Chan

2013-05-01

Full Text Available Quorum sensing is a system of stimuli and responses in relation to bacterial cell population density that regulates gene expression, including virulence determinants. Consequently, quorum sensing has been an attractive target for the development of novel anti-infective measures that do not rely on the use of antibiotics. Anti-quorum sensing has been a promising strategy to combat bacterial infections as it is unlikely to develop multidrug resistant pathogens since it does not impose any selection pressure. A number of anti-quorum sensing approaches have been documented and plant-based natural products have been extensively studied in this context. Plant matter is one of the major sources of chemicals in use today in various industries, ranging from the pharmaceutical, cosmetic, and food biotechnology to the textile industries. Just like animals and humans, plants are constantly exposed to bacterial infections, it is therefore logical to expect that plants have developed sophisticated of chemical mechanisms to combat pathogens. In this review, we have surveyed the various types of plant-based natural products that exhibit anti-quorum sensing properties and their anti-quorum sensing mechanisms.

Cryogenic and Gas System Piping Pressure Tests (A Collection of PT Permits)

International Nuclear Information System (INIS)

Rucinski, Russell A.

2002-01-01

This engineering note is a collection of pipe pressure testing documents for various sections of piping for the D-Zero cryogenic and gas systems. High pressure piping must conform with FESHM chapter 5031.1. Piping lines with ratings greater than 150 psig have a pressure test done before the line is put into service. These tests require the use of pressure testing permits. It is my intent that all pressure piping over which my group has responsibility conforms to the chapter. This includes the liquid argon and liquid helium and liquid nitrogen cryogenic systems. It also includes the high pressure air system, and the high pressure gas piping of the WAMUS and MDT gas systems. This is not an all inclusive compilation of test documentation. Some piping tests have their own engineering note. Other piping section test permits are included in separate safety review documents. So if it isn't here, that doesn't mean that it wasn't tested. D-Zero has a back up air supply system to add reliability to air compressor systems. The system includes high pressure piping which requires a review per FESHM 5031.1. The core system consists of a pressurized tube trailer, supply piping into the building and a pressure reducing regulator tied into the air compressor system discharge piping. Air flows from the trailer if the air compressor discharge pressure drops below the regulator setting. The tube trailer is periodically pumped back up to approximately 2000 psig. A high pressure compressor housed in one of the exterior buildings is used for that purpose. The system was previously documented, tested and reviewed for Run I, except for the recent addition of piping to and from the high pressure compressor. The following documents are provided for review of the system: (1) Instrument air flow schematic, drg. 3740.000-ME-273995 rev. H; (2) Component list for air system; (3) Pressure testing permit for high pressure piping; (4) Documentation from Run I contained in D-Zero Engineering note

Limit regulation system for pressurized water nuclear reactors

International Nuclear Information System (INIS)

Aleite, W.; Bock, H.W.

1976-01-01

Described is a limit regulation system for a pressurized water nuclear reactor in combination with a steam generating system connected to a turbine, the nuclear reactor having control rods as well as an operational regulation system and a protective system, which includes reactor power limiting means operatively associated with the control rods for positioning the same and having response values between operating ranges of the operational regulation system, on the one hand, and response values of the protective system, on the other hand, and a live steam-minimal pressure regulation system cooperating with the reactor power limiting means and operatively connected to a steam inlet valve to the turbine for controlling the same

Bioinspired pressure actuated adhesive system

NARCIS (Netherlands)

Paretkar, D.R.; Kamperman, M.M.G.; Schneider, A.S.; Martina, D.; Creton, C.; Arzt, E.

2011-01-01

We developed a dry synthetic adhesive system inspired by gecko feet adhesion that can switch reversibly from adhesion to non-adhesion with applied pressure as external stimulus. Micropatterned polydimethylsiloxane (PDMS) surfaces with pillars of 30 µm length and 10 µm diameter were fabricated using

Code Description for Generation of Meteorological Height and Pressure Level and Layer Profiles

Science.gov (United States)

2016-06-01

defined by user input height or pressure levels. It can process input profiles from sensing systems such as radiosonde, lidar, or wind profiling radar...routine may be required for different input types and formats. meteorological sounding interpolation , integrated mean layer values, US Army Research...or other radiosonde soundings. There are 2 main versions or “methods” that produce output in height- or pressure-based profiles of interpolated level

Flexible and self-powered temperature-pressure dual-parameter sensors using microstructure-frame-supported organic thermoelectric materials.

Science.gov (United States)

Zhang, Fengjiao; Zang, Yaping; Huang, Dazhen; Di, Chong-an; Zhu, Daoben

2015-09-21

Skin-like temperature- and pressure-sensing capabilities are essential features for the next generation of artificial intelligent products. Previous studies of e-skin and smart elements have focused on flexible pressure sensors, whereas the simultaneous and sensitive detection of temperature and pressure with a single device remains a challenge. Here we report developing flexible dual-parameter temperature-pressure sensors based on microstructure-frame-supported organic thermoelectric (MFSOTE) materials. The effective transduction of temperature and pressure stimuli into two independent electrical signals permits the instantaneous sensing of temperature and pressure with an accurate temperature resolution of pressure-sensing sensitivity of up to 28.9 kPa(-1). More importantly, these dual-parameter sensors can be self-powered with outstanding sensing performance. The excellent sensing properties of MFSOTE-based devices, together with their unique advantages of low cost and large-area fabrication, make MFSOTE materials possess promising applications in e-skin and health-monitoring elements.

Linking climate change education through the integration of a kite-borne remote sensing system

Directory of Open Access Journals (Sweden)

Yichun Xie

2014-09-01

Full Text Available A majority of secondary science teachers are found to include the topic of climate change in their courses. However, teachers informally and sporadically discuss climate change and students rarely understand the underlying scientific concepts. The project team developed an innovative pedagogical approach, in which teachers and students learn climate change concepts by analyzing National Aeronautics and Space Administration (NASA global data collected through satellites and by imitating the NASA data collection process through NASA Airborne Earth Research Observation Kites And Tethered Systems (AEROKATS, a kite-borne remote sensing system. Besides AEROKATS, other major components of this system include a web-collection of NASA and remote sensing data and related educational resources, project-based learning for teacher professional development, teacher and student field trips, iOS devices, smart field data collector apps, portable weather stations, probeware, and a virtual teacher collaboratory supported with a GIS-enabled mapping portal. Three sets of research instruments, the NASA Long-Term Experience –Educator End of Event Survey, the Teacher End of Project Survey, and the pre-and-post-Investigating Climate Change and Remote Sensing (ICCARS project student exams, are adapted to study the pedagogical impacts of the NASA AEROKATS remote sensing system. These findings confirm that climate change education is more effective when both teachers and students actively participate in authentic scientific inquiry by collecting and analyzing remote sensing data, developing hypotheses, designing experiments, sharing findings, and discussing results.

Evaluation of anticipatory signal to steam generator pressure control program for 700 MWe Indian pressurized heavy water reactor

International Nuclear Information System (INIS)

Pahari, S.; Hajela, S.; Rammohan, H. P.; Malhotra, P. K.; Ghadge, S. G.

2012-01-01

700 MWe Indian Pressurized Heavy Water Reactor (IPHWR) is horizontal channel type reactor with partial boiling at channel outlet. Due to boiling, it has a large volume of vapor present in the primary loops. It has two primary loops connected with the help of pressurizer surge line. The pressurizer has a large capacity and is partly filled by liquid and partly by vapor. Large vapor volume improves compressibility of the system. During turbine trip or load rejection, pressure builds up in Steam Generator (SG). This leads to pressurization of Primary Heat Transport System (PHTS). To control pressurization of SG and PHTS, around 70% of the steam generated in SG is dumped into the condenser by opening Condenser Steam Dump Valves (CSDVs) and rest of the steam is released to the atmosphere by opening Atmospheric Steam Discharge Valves (ASDVs) immediately after sensing the event. This is accomplished by adding anticipatory signal to the output of SG pressure controller. Anticipatory signal is proportional to the thermal power of reactor and the proportionality constant is set so that SG pressure controller's output jacks up to ASDV opening range when operating at 100% FP. To simulate this behavior for 700 MWe IPHWR, Primary and secondary heat transport system is modeled. SG pressure control and other process control program have also been modeled to capture overall plant dynamics. Analysis has been carried out with 3-D neutron kinetics coupled thermal hydraulic computer code ATMIKA.T to evaluate the effect of the anticipatory signal on PHT pressure and over all plant dynamics during turbine trip in 700 MWe IPHWR. This paper brings out the results of the analysis with and without considering anticipatory signal in SG pressure control program during turbine trip. (authors)

Development of the vacuum system pressure responce analysis code PRAC

International Nuclear Information System (INIS)

Horie, Tomoyoshi; Kawasaki, Kouzou; Noshiroya, Shyoji; Koizumi, Jun-ichi.

1985-03-01

In this report, we show the method and numerical results of the vacuum system pressure responce analysis code. Since fusion apparatus is made up of many vacuum components, it is required to analyze pressure responce at any points of the system when vacuum system is designed or evaluated. For that purpose evaluating by theoretical solution is insufficient. Numerical analysis procedure such as finite difference method is usefull. In the PRAC code (Pressure Responce Analysis Code), pressure responce is obtained solving derivative equations which is obtained from the equilibrium relation of throughputs and contain the time derivative of pressure. As it considers both molecular and viscous flows, the coefficients of the equation depend on the pressure and the equations become non-linear. This non-linearity is treated as piece-wise linear within each time step. Verification of the code is performed for the simple problems. The agreement between numerical and theoretical solutions is good. To compare with the measured results, complicated model of gas puffing system is analyzed. The agreement is well for practical use. This code will be a useful analytical tool for designing and evaluating vacuum systems such as fusion apparatus. (author)

BioRadioTransmitter: a self-powered wireless glucose-sensing system.

Science.gov (United States)

Hanashi, Takuya; Yamazaki, Tomohiko; Tsugawa, Wakako; Ikebukuro, Kazunori; Sode, Koji

2011-09-01

Although an enzyme fuel cell can be utilized as a glucose sensor, the output power generated is too low to power a device such as a currently available transmitter and operating system, and an external power source is required for operating an enzyme-fuel-cell-based biosensing system. We proposed a novel biosensor that we named BioCapacitor, in which a capacitor serves as a transducer. In this study, we constructed a new BioCapacitor-based system with an added radio-transmitter circuit and a miniaturized enzyme fuel cell. A miniaturized direct-electron-transfer-type compartmentless enzyme fuel cell was constructed with flavin adenine dinucleotide-dependent glucose dehydrogenase complex-based anode and a bilirubin-oxidase-based cathode. For construction of a BioRadioTransmitter wireless sensing system, a capacitor, an ultra-low-voltage charge-pump-integrated circuit, and Hartley oscillator circuit were connected to the miniaturized enzyme fuel cell. A radio-receiver circuit, comprising two field-effect transistors and a coil as an antenna, was used to amplify the signal generated from the biofuel cells. Radio wave signals generated by the BioRadioTransmitter were received, amplified, and converted from alternate to direct current by the radio receiver. When the capacitor discharges in the presence of glucose, the BioRadioTransmitter generates a radio wave, which is monitored by a radio receiver connected wirelessly to the sensing device. Magnitude of the radio wave transmission frequency change observed at the radio receiver was correlated to glucose concentration in the fuel cells. We constructed a stand-alone, self-powered, wireless glucose-sensing system called a BioRadioTransmitter by using a radio transmitter in which the radio wave transmission frequency changes with the glucose concentration in the fuel cell. The BioRadioTransmitter is a significant advance toward construction of an implantable continuous glucose monitor. © 2011 Diabetes Technology Society.

Pressure sensor apparatus for indicating pressure in the body

International Nuclear Information System (INIS)

Hittman, F.; Fleischmann, L.W.

1981-01-01

A novel pressure sensor for indicating pressure in the body cavities of humans or animals is described in detail. The pressure sensor apparatus is relatively small and is easily implantable. It consists of a radioactive source (e.g. Pr-145, C-14, Ni-63, Sr-90 and Am-241) and associated radiation shielding and a bellows. The pressure acting upon the sensing tambour causes the bellows to expand and contract. This is turn causes the radiation shielding to move and changes in pressure can then be monitored external to the body using a conventional nuclear detector. The bellows is made of resilient material (e.g. gold plated nickel) and has a wall thickness of approximately 0.0003 inches. The apparatus is essentially insensitive to temperature variations. (U.K.)

Particle-based optical pressure sensors for 3D pressure mapping.

Science.gov (United States)

Banerjee, Niladri; Xie, Yan; Chalaseni, Sandeep; Mastrangelo, Carlos H

2015-10-01

This paper presents particle-based optical pressure sensors for in-flow pressure sensing, especially for microfluidic environments. Three generations of pressure sensitive particles have been developed- flat planar particles, particles with integrated retroreflectors and spherical microballoon particles. The first two versions suffer from pressure measurement dependence on particles orientation in 3D space and angle of interrogation. The third generation of microspherical particles with spherical symmetry solves these problems making particle-based manometry in microfluidic environment a viable and efficient methodology. Static and dynamic pressure measurements have been performed in liquid medium for long periods of time in a pressure range of atmospheric to 40 psi. Spherical particles with radius of 12 μm and balloon-wall thickness of 0.5 μm are effective for more than 5 h in this pressure range with an error of less than 5%.

A wearable 3D motion sensing system integrated with a Bluetooth smart phone application: A system level overview

KAUST Repository

Karimi, Muhammad Akram

2018-01-02

An era of ubiquitous motion sensing has just begun. All electronic gadgets ranging from game consoles to mobile phones have some sort of motion sensors in them. In contrast to rigid motion sensing systems, this paper presents a system level description of a wearable 3D motion sensor. The sensing mechanism is based upon well-established magnetic and inertial measurement unit (MIMU), which integrates accelerometer, gyroscope and magnetometer data. Two sensor boards have been integrated within a wearable arm sleeve to capture 3D orientation of the human arm. The sensors have been interfaced with a Bluetooth transceiver chip, which transmits data to a mobile phone app using standard Bluetooth protocol. An android mobile phone app has been developed to display the human arm motion in real time.

High pressure common rail injection system modeling and control.

Science.gov (United States)

Wang, H P; Zheng, D; Tian, Y

2016-07-01

In this paper modeling and common-rail pressure control of high pressure common rail injection system (HPCRIS) is presented. The proposed mathematical model of high pressure common rail injection system which contains three sub-systems: high pressure pump sub-model, common rail sub-model and injector sub-model is a relative complicated nonlinear system. The mathematical model is validated by the software Matlab and a virtual detailed simulation environment. For the considered HPCRIS, an effective model free controller which is called Extended State Observer - based intelligent Proportional Integral (ESO-based iPI) controller is designed. And this proposed method is composed mainly of the referred ESO observer, and a time delay estimation based iPI controller. Finally, to demonstrate the performances of the proposed controller, the proposed ESO-based iPI controller is compared with a conventional PID controller and ADRC. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Stretchable Triboelectric-Photonic Smart Skin for Tactile and Gesture Sensing.

Science.gov (United States)

Bu, Tianzhao; Xiao, Tianxiao; Yang, Zhiwei; Liu, Guoxu; Fu, Xianpeng; Nie, Jinhui; Guo, Tong; Pang, Yaokun; Zhao, Junqing; Xi, Fengben; Zhang, Chi; Wang, Zhong Lin

2018-04-01

Smart skin is expected to be stretchable and tactile for bionic robots as the medium with the ambient environment. Here, a stretchable triboelectric-photonic smart skin (STPS) is reported that enables multidimensional tactile and gesture sensing for a robotic hand. With a grating-structured metal film as the bioinspired skin stripe, the STPS exhibits a tunable aggregation-induced emission in a lateral tensile range of 0-160%. Moreover, the STPS can be used as a triboelectric nanogenerator for vertical pressure sensing with a maximum sensitivity of 34 mV Pa -1 . The pressure sensing characteristics can remain stable in different stretching conditions, which demonstrates a synchronous and independent sensing property for external stimuli with great durability. By integrating on a robotic hand as a conformal covering, the STPS shows multidimensional mechanical sensing abilities for external touch and different gestures with joints bending. This work has first demonstrated a triboelectric-photonic coupled multifunctional sensing terminal, which may have great applications in human-machine interaction, soft robots, and artificial intelligence. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Self-Evaluation of PANDA-FBG Based Sensing System for Dynamic Distributed Strain and Temperature Measurement.

Science.gov (United States)

Zhu, Mengshi; Murayama, Hideaki; Wada, Daichi

2017-10-12

A novel method is introduced in this work for effectively evaluating the performance of the PANDA type polarization-maintaining fiber Bragg grating (PANDA-FBG) distributed dynamic strain and temperature sensing system. Conventionally, the errors during the measurement are unknown or evaluated by using other sensors such as strain gauge and thermocouples. This will make the sensing system complicated and decrease the efficiency since more than one kind of sensor is applied for the same measurand. In this study, we used the approximately constant ratio of primary errors in strain and temperature measurement and realized the self-evaluation of the sensing system, which can significantly enhance the applicability, as well as the reliability in strategy making.

Application of the FADS system on the Re-entry Module

Science.gov (United States)

Zhen, Huang

2016-07-01

The aerodynamic model for Flush Air Data Sensing System (FADS) is built based on the surface pressure distribution obtained through the pressure orifices laid on specific positions of the surface,and the flight parameters,such as angle of attack,angle of side-slip,Mach number,free-stream static pressure and dynamic pressure are inferred from the aerodynamic model.The flush air data sensing system (FADS) has been used on several flight tests of aircraft and re-entry vehicle,such as,X-15,space shuttle,F-14,X-33,X-43A and so on. This paper discusses the application of the FADS on the re-entry module with blunt body to obtain high-precision aerodynamic parameters.First of all,a basic theory and operating principle of the FADS is shown.Then,the applications of the FADS on typical aircrafts and re-entry vehicles are described.Thirdly,the application mode on the re-entry module with blunt body is discussed in detail,including aerodynamic simulation,pressure distribution,trajectory reconstruction and the hardware shoule be used,such as flush air data sensing system(FADS),inertial navigation system (INS),data acquisition system,data storage system.Finally,ablunt module re-entry flight test from low earth orbit (LEO) is planned to obtain aerodynamic parameters and amend the aerodynamic model with this FADS system data.The results show that FADS system can be applied widely in re-entry module with blunt bodies.

Evaluation to Mitigate Secondary System Peak Pressure for Loss of Condenser Vacuum Event

Energy Technology Data Exchange (ETDEWEB)

Choi, Bong Oh; Park, Jong Cheol; Park, Min Soo; Lee, Gyu Cheon; Kim, Shin Whan [KEPCO E and C, Inc., Daejeon (Korea, Republic of)

2015-10-15

In this paper, countermeasures to compensate the increased secondary pressure are introduced and evaluated. From the standpoint of the secondary system pressurization, consideration of the PPCS may result in a conservative secondary system peak pressure. The control systems are generally credited for the safety analysis if the analysis produces conservative results. However, in most of all non-loss of coolant accident (non-LOCA) events, the control system helps to mitigate a transient state. Accordingly, the safety analysis of non-LOCA assumes the control systems are in the manual mode of operation. The loss of condenser vacuum event (LOCV) is a typical anticipated operational occurrence (AOO) which results in an increase in primary and secondary system pressure. The pressurizer (PZR) pressure control system (PPCS) will function to reduce the primary system pressure increase during the transient. Therefore, it is assumed to be in manual mode and credit is not taken for its functioning. However, crediting the function of PPCS has been found to be more conservative with regard to the secondary system pressure. This is due to the delay of the reactor trip on high pressurizer pressure (HPP) and results in an increase in secondary pressure.

Pressure Systems Stored-Energy Threshold Risk Analysis

Energy Technology Data Exchange (ETDEWEB)

Paulsen, Samuel S.

2009-08-25

Federal Regulation 10 CFR 851, which became effective February 2007, brought to light potential weaknesses regarding the Pressure Safety Program at the Pacific Northwest National Laboratory (PNNL). The definition of a pressure system in 10 CFR 851 does not contain a limit based upon pressure or any other criteria. Therefore, the need for a method to determine an appropriate risk-based hazard level for pressure safety was identified. The Laboratory has historically used a stored energy of 1000 lbf-ft to define a pressure hazard; however, an analytical basis for this value had not been documented. This document establishes the technical basis by evaluating the use of stored energy as an appropriate criterion to establish a pressure hazard, exploring a suitable risk threshold for pressure hazards, and reviewing the methods used to determine stored energy. The literature review and technical analysis concludes the use of stored energy as a method for determining a potential risk, the 1000 lbf-ft threshold, and the methods used by PNNL to calculate stored energy are all appropriate. Recommendations for further program improvements are also discussed

Study on algorithm of process neural network for soft sensing in sewage disposal system

Science.gov (United States)

Liu, Zaiwen; Xue, Hong; Wang, Xiaoyi; Yang, Bin; Lu, Siying

2006-11-01

A new method of soft sensing based on process neural network (PNN) for sewage disposal system is represented in the paper. PNN is an extension of traditional neural network, in which the inputs and outputs are time-variation. An aggregation operator is introduced to process neuron, and it makes the neuron network has the ability to deal with the information of space-time two dimensions at the same time, so the data processing enginery of biological neuron is imitated better than traditional neuron. Process neural network with the structure of three layers in which hidden layer is process neuron and input and output are common neurons for soft sensing is discussed. The intelligent soft sensing based on PNN may be used to fulfill measurement of the effluent BOD (Biochemical Oxygen Demand) from sewage disposal system, and a good training result of soft sensing was obtained by the method.

Crowd Sensing-Enabling Security Service Recommendation for Social Fog Computing Systems

Directory of Open Access Journals (Sweden)

Jun Wu

2017-07-01

Full Text Available Fog computing, shifting intelligence and resources from the remote cloud to edge networks, has the potential of providing low-latency for the communication from sensing data sources to users. For the objects from the Internet of Things (IoT to the cloud, it is a new trend that the objects establish social-like relationships with each other, which efficiently brings the benefits of developed sociality to a complex environment. As fog service become more sophisticated, it will become more convenient for fog users to share their own services, resources, and data via social networks. Meanwhile, the efficient social organization can enable more flexible, secure, and collaborative networking. Aforementioned advantages make the social network a potential architecture for fog computing systems. In this paper, we design an architecture for social fog computing, in which the services of fog are provisioned based on “friend” relationships. To the best of our knowledge, this is the first attempt at an organized fog computing system-based social model. Meanwhile, social networking enhances the complexity and security risks of fog computing services, creating difficulties of security service recommendations in social fog computing. To address this, we propose a novel crowd sensing-enabling security service provisioning method to recommend security services accurately in social fog computing systems. Simulation results show the feasibilities and efficiency of the crowd sensing-enabling security service recommendation method for social fog computing systems.

Crowd Sensing-Enabling Security Service Recommendation for Social Fog Computing Systems

Science.gov (United States)

Wu, Jun; Su, Zhou; Li, Jianhua

2017-01-01

Fog computing, shifting intelligence and resources from the remote cloud to edge networks, has the potential of providing low-latency for the communication from sensing data sources to users. For the objects from the Internet of Things (IoT) to the cloud, it is a new trend that the objects establish social-like relationships with each other, which efficiently brings the benefits of developed sociality to a complex environment. As fog service become more sophisticated, it will become more convenient for fog users to share their own services, resources, and data via social networks. Meanwhile, the efficient social organization can enable more flexible, secure, and collaborative networking. Aforementioned advantages make the social network a potential architecture for fog computing systems. In this paper, we design an architecture for social fog computing, in which the services of fog are provisioned based on “friend” relationships. To the best of our knowledge, this is the first attempt at an organized fog computing system-based social model. Meanwhile, social networking enhances the complexity and security risks of fog computing services, creating difficulties of security service recommendations in social fog computing. To address this, we propose a novel crowd sensing-enabling security service provisioning method to recommend security services accurately in social fog computing systems. Simulation results show the feasibilities and efficiency of the crowd sensing-enabling security service recommendation method for social fog computing systems. PMID:28758943

SENSOR: a tool for the simulation of hyperspectral remote sensing systems

Science.gov (United States)

Börner, Anko; Wiest, Lorenz; Keller, Peter; Reulke, Ralf; Richter, Rolf; Schaepman, Michael; Schläpfer, Daniel

The consistent end-to-end simulation of airborne and spaceborne earth remote sensing systems is an important task, and sometimes the only way for the adaptation and optimisation of a sensor and its observation conditions, the choice and test of algorithms for data processing, error estimation and the evaluation of the capabilities of the whole sensor system. The presented software simulator SENSOR (Software Environment for the Simulation of Optical Remote sensing systems) includes a full model of the sensor hardware, the observed scene, and the atmosphere in between. The simulator consists of three parts. The first part describes the geometrical relations between scene, sun, and the remote sensing system using a ray-tracing algorithm. The second part of the simulation environment considers the radiometry. It calculates the at-sensor radiance using a pre-calculated multidimensional lookup-table taking the atmospheric influence on the radiation into account. The third part consists of an optical and an electronic sensor model for the generation of digital images. Using SENSOR for an optimisation requires the additional application of task-specific data processing algorithms. The principle of the end-to-end-simulation approach is explained, all relevant concepts of SENSOR are discussed, and first examples of its use are given. The verification of SENSOR is demonstrated. This work is closely related to the Airborne PRISM Experiment (APEX), an airborne imaging spectrometer funded by the European Space Agency.

Tandem-Mirror Experiment-Upgrade neutral pressure measurement diagnostic systems

International Nuclear Information System (INIS)

Pickles, W.L.; Allen, S.L.; Hill, D.N.; Hunt, A.L.; Simonen, T.C.

1985-01-01

The Tandem-Mirror Experiment-Upgrade (TMX-U) has a large and complex system of Bayard--Alpert, magnetron, and Penning gauges, in addition to mass spectrometers (RGA), all of which measure neutral pressures in the many internal regions of TMX-U. These pressure measurements are used as part of the confinement physics data base as well as for management of the TMX-U vacuum system. Dynamic pressures are modeled by a coupled-volumes simulation code, which includes wall reflux, getter pumping, and plasma pumping

Famine Early Warning Systems and Their Use of Satellite Remote Sensing Data

Science.gov (United States)

Brown, Molly E.; Essam, Timothy; Leonard, Kenneth

2011-01-01

Famine early warning organizations have experience that has much to contribute to efforts to incorporate climate and weather information into economic and political systems. Food security crises are now caused almost exclusively by problems of food access, not absolute food availability, but the role of monitoring agricultural production both locally and globally remains central. The price of food important to the understanding of food security in any region, but it needs to be understood in the context of local production. Thus remote sensing is still at the center of much food security analysis, along with an examination of markets, trade and economic policies during food security analyses. Technology including satellite remote sensing, earth science models, databases of food production and yield, and modem telecommunication systems contributed to improved food production information. Here we present an econometric approach focused on bringing together satellite remote sensing and market analysis into food security assessment in the context of early warning.

Low-level wind response to mesoscale pressure systems

Science.gov (United States)

Garratt, J. R.; Physick, W. L.

1983-09-01

Observations are presented which show a strong correlation between low-level wind behaviour (e.g., rotation near the surface) and the passage of mesoscale pressure systems. The latter are associated with frontal transition zones, are dominated by a pressure-jump line and a mesoscale high pressure area, and produce locally large horizontal pressure gradients. The wind observations are simulated by specifying a time sequence of perturbation pressure gradient and subsequently solving the vertically-integrated momentum equations with appropriate initial conditions. Very good agreement is found between observed and calculated winds; in particular, (i) a 360 ° rotation in wind on passage of the mesoscale high; (ii) wind-shift lines produced dynamically by the pressure-jump line; (iii) rapid linear increase in wind speed on passage of the pressure jump.

Development and Implementation of an Advanced Power Management Algorithm for Electronic Load Sensing on a Telehandler

DEFF Research Database (Denmark)

Hansen, Rico Hjerm; Andersen, Torben Ole; Pedersen, Henrik C.

2010-01-01

The relevance of electronic control of mobile hydraulic systems is increasing as hydraulic components are implemented with more electrical sensors and actuators. This paper presents how the traditional Hydro-mechanical Load Sensing (HLS) control of a specific mobile hydraulic application......, a telehandler, can be replaced with electronic control, i.e. Electronic Load Sensing (ELS). The motivation is the potential of improved dynamic performance and power utilization, along with reducing the mechanical complexity by moving traditional hydro-mechanical implemented features such as pressure control...

49 CFR 192.197 - Control of the pressure of gas delivered from high-pressure distribution systems.

Science.gov (United States)

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Control of the pressure of gas delivered from high-pressure distribution systems. 192.197 Section 192.197 Transportation Other Regulations Relating to... STANDARDS Design of Pipeline Components § 192.197 Control of the pressure of gas delivered from high...

Kingfisher: a system for remote sensing image database management

Science.gov (United States)

Bruzzo, Michele; Giordano, Ferdinando; Dellepiane, Silvana G.

2003-04-01

At present retrieval methods in remote sensing image database are mainly based on spatial-temporal information. The increasing amount of images to be collected by the ground station of earth observing systems emphasizes the need for database management with intelligent data retrieval capabilities. The purpose of the proposed method is to realize a new content based retrieval system for remote sensing images database with an innovative search tool based on image similarity. This methodology is quite innovative for this application, at present many systems exist for photographic images, as for example QBIC and IKONA, but they are not able to extract and describe properly remote image content. The target database is set by an archive of images originated from an X-SAR sensor (spaceborne mission, 1994). The best content descriptors, mainly texture parameters, guarantees high retrieval performances and can be extracted without losses independently of image resolution. The latter property allows DBMS (Database Management System) to process low amount of information, as in the case of quick-look images, improving time performance and memory access without reducing retrieval accuracy. The matching technique has been designed to enable image management (database population and retrieval) independently of dimensions (width and height). Local and global content descriptors are compared, during retrieval phase, with the query image and results seem to be very encouraging.

Hierarchical fiber-optic-based sensing system: impact damage monitoring of large-scale CFRP structures

International Nuclear Information System (INIS)

Minakuchi, Shu; Banshoya, Hidehiko; Takeda, Nobuo; Tsukamoto, Haruka

2011-01-01

This study proposes a novel fiber-optic-based hierarchical sensing concept for monitoring randomly induced damage in large-scale composite structures. In a hierarchical system, several kinds of specialized devices are hierarchically combined to form a sensing network. Specifically, numerous three-dimensionally structured sensor devices are distributed throughout the whole structural area and connected with an optical fiber network through transducing mechanisms. The distributed devices detect damage, and the fiber-optic network gathers the damage signals and transmits the information to a measuring instrument. This study began by discussing the basic concept of a hierarchical sensing system through comparison with existing fiber-optic-based systems, and an impact damage detection system was then proposed to validate the new concept. The sensor devices were developed based on comparative vacuum monitoring (CVM), and Brillouin-based distributed strain measurement was utilized to identify damaged areas. Verification tests were conducted step-by-step, beginning with a basic test using a single sensor unit, and, finally, the proposed monitoring system was successfully verified using a carbon fiber reinforced plastic (CFRP) fuselage demonstrator. It was clearly confirmed that the hierarchical system has better repairability, higher robustness, and a wider monitorable area compared to existing systems

SU-E-T-258: Development of a New Patient Set-Up Monitoring System Using Force Sensing Resistor (FSR) Sensor for the Radiation Therapy

International Nuclear Information System (INIS)

Cho, M; Kim, T; Kang, S; Kim, D; Kim, K; Shin, D; Suh, T

2015-01-01

Purpose: The purpose of this work is to develop a new patient set-up monitoring system using force sensing resistor (FSR) sensors that can confirm pressure of contact surface and evaluate its feasibility. Methods: In this study, we focused on develop the patient set-up monitoring system to compensate for the limitation of existing optical based monitoring system, so the developed system can inform motion in the radiation therapy. The set-up monitoring system was designed consisting of sensor units (FSR sensor), signal conditioning devices (USB cable/interface electronics), a control PC, and a developed analysis software. The sensor unit was made by attaching FSR sensor and dispersing pressure sponge to prevent error which is caused by concentrating specific point. Measured signal from the FSR sensor was sampled to arduino mega 2560 microcontroller, transferred to control PC by using serial communication. The measured data went through normalization process. The normalized data was displayed through the developed graphic user interface (GUI) software. The software was designed to display a single sensor unit intensity (maximum 16 sensors) and display 2D pressure distribution (using 16 sensors) according to the purpose. Results: Changes of pressure value according to motion was confirmed by the developed set-up monitoring system. Very small movement such as little physical change in appearance can be confirmed using a single unit and using 2D pressure distribution. Also, the set-up monitoring system can observe in real time. Conclusion: In this study, we developed the new set-up monitoring system using FSR sensor. Especially, we expect that the new set-up monitoring system is suitable for motion monitoring of blind area that is hard to confirm existing optical system and compensate existing optical based monitoring system. As a further study, an integrated system will be constructed through correlation of existing optical monitoring system. This work was supported by

SU-E-T-258: Development of a New Patient Set-Up Monitoring System Using Force Sensing Resistor (FSR) Sensor for the Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

Cho, M; Kim, T; Kang, S; Kim, D; Kim, K; Shin, D; Suh, T [The Catholic University of Korea College of Medicine, Seoul (Korea, Republic of)

2015-06-15

Purpose: The purpose of this work is to develop a new patient set-up monitoring system using force sensing resistor (FSR) sensors that can confirm pressure of contact surface and evaluate its feasibility. Methods: In this study, we focused on develop the patient set-up monitoring system to compensate for the limitation of existing optical based monitoring system, so the developed system can inform motion in the radiation therapy. The set-up monitoring system was designed consisting of sensor units (FSR sensor), signal conditioning devices (USB cable/interface electronics), a control PC, and a developed analysis software. The sensor unit was made by attaching FSR sensor and dispersing pressure sponge to prevent error which is caused by concentrating specific point. Measured signal from the FSR sensor was sampled to arduino mega 2560 microcontroller, transferred to control PC by using serial communication. The measured data went through normalization process. The normalized data was displayed through the developed graphic user interface (GUI) software. The software was designed to display a single sensor unit intensity (maximum 16 sensors) and display 2D pressure distribution (using 16 sensors) according to the purpose. Results: Changes of pressure value according to motion was confirmed by the developed set-up monitoring system. Very small movement such as little physical change in appearance can be confirmed using a single unit and using 2D pressure distribution. Also, the set-up monitoring system can observe in real time. Conclusion: In this study, we developed the new set-up monitoring system using FSR sensor. Especially, we expect that the new set-up monitoring system is suitable for motion monitoring of blind area that is hard to confirm existing optical system and compensate existing optical based monitoring system. As a further study, an integrated system will be constructed through correlation of existing optical monitoring system. This work was supported by

Integrated Circuit Design of 3 Electrode Sensing System Using Two-Stage Operational Amplifier

Science.gov (United States)

Rani, S.; Abdullah, W. F. H.; Zain, Z. M.; N, Aqmar N. Z.

2018-03-01

This paper presents the design of a two-stage operational amplifier(op amp) for 3-electrode sensing system readout circuits. The designs have been simulated using 0.13μm CMOS technology from Silterra (Malaysia) with Mentor graphics tools. The purpose of this projects is mainly to design a miniature interfacing circuit to detect the redox reaction in the form of current using standard analog modules. The potentiostat consists of several op amps combined together in order to analyse the signal coming from the 3-electrode sensing system. This op amp design will be used in potentiostat circuit device and to analyse the functionality for each module of the system.

Water cycles in closed ecological systems: effects of atmospheric pressure.

Science.gov (United States)

Rygalov, Vadim Y; Fowler, Philip A; Metz, Joannah M; Wheeler, Raymond M; Bucklin, Ray A

2002-01-01

In bioregenerative life support systems that use plants to generate food and oxygen, the largest mass flux between the plants and their surrounding environment will be water. This water cycle is a consequence of the continuous change of state (evaporation-condensation) from liquid to gas through the process of transpiration and the need to transfer heat (cool) and dehumidify the plant growth chamber. Evapotranspiration rates for full plant canopies can range from ~1 to 10 L m-2 d-1 (~1 to 10 mm m-2 d-1), with the rates depending primarily on the vapor pressure deficit (VPD) between the leaves and the air inside the plant growth chamber. VPD in turn is dependent on the air temperature, leaf temperature, and current value of relative humidity (RH). Concepts for developing closed plant growth systems, such as greenhouses for Mars, have been discussed for many years and the feasibility of such systems will depend on the overall system costs and reliability. One approach for reducing system costs would be to reduce the operating pressure within the greenhouse to reduce structural mass and gas leakage. But managing plant growth environments at low pressures (e.g., controlling humidity and heat exchange) may be difficult, and the effects of low-pressure environments on plant growth and system water cycling need further study. We present experimental evidence to show that water saturation pressures in air under isothermal conditions are only slightly affected by total pressure, but the overall water flux from evaporating surfaces can increase as pressure decreases. Mathematical models describing these observations are presented, along with discussion of the importance for considering "water cycles" in closed bioregenerative life support systems.

Water cycles in closed ecological systems: effects of atmospheric pressure

Science.gov (United States)

Rygalov, Vadim Y.; Fowler, Philip A.; Metz, Joannah M.; Wheeler, Raymond M.; Bucklin, Ray A.; Sager, J. C. (Principal Investigator)

2002-01-01

In bioregenerative life support systems that use plants to generate food and oxygen, the largest mass flux between the plants and their surrounding environment will be water. This water cycle is a consequence of the continuous change of state (evaporation-condensation) from liquid to gas through the process of transpiration and the need to transfer heat (cool) and dehumidify the plant growth chamber. Evapotranspiration rates for full plant canopies can range from 1 to 10 L m-2 d-1 (1 to 10 mm m-2 d-1), with the rates depending primarily on the vapor pressure deficit (VPD) between the leaves and the air inside the plant growth chamber. VPD in turn is dependent on the air temperature, leaf temperature, and current value of relative humidity (RH). Concepts for developing closed plant growth systems, such as greenhouses for Mars, have been discussed for many years and the feasibility of such systems will depend on the overall system costs and reliability. One approach for reducing system costs would be to reduce the operating pressure within the greenhouse to reduce structural mass and gas leakage. But managing plant growth environments at low pressures (e.g., controlling humidity and heat exchange) may be difficult, and the effects of low-pressure environments on plant growth and system water cycling need further study. We present experimental evidence to show that water saturation pressures in air under isothermal conditions are only slightly affected by total pressure, but the overall water flux from evaporating surfaces can increase as pressure decreases. Mathematical models describing these observations are presented, along with discussion of the importance for considering "water cycles" in closed bioregenerative life support systems.

Electrical Pressurization Concept for the Orion MPCV European Service Module Propulsion System

Science.gov (United States)

Meiss, Jan-Hendrik; Weber, Jorg; Ierardo, Nicola; Quinn, Frank D.; Paisley, Jonathan

2015-01-01

The paper presents the design of the pressurization system of the European Service Module (ESM) of the Orion Multi-Purpose Crew Vehicle (MPCV). Being part of the propulsion subsystem, an electrical pressurization concept is implemented to condition propellants according to the engine needs via a bang-bang regulation system. Separate pressurization for the oxidizer and the fuel tank permits mixture ratio adjustments and prevents vapor mixing of the two hypergolic propellants during nominal operation. In case of loss of pressurization capability of a single side, the system can be converted into a common pressurization system. The regulation concept is based on evaluation of a set of tank pressure sensors and according activation of regulation valves, based on a single-failure tolerant weighting of three pressure signals. While regulation is performed on ESM level, commanding of regulation parameters as well as failure detection, isolation and recovery is performed from within the Crew Module, developed by Lockheed Martin Space System Company. The overall design and development maturity presented is post Preliminary Design Review (PDR) and reflects the current status of the MPCV ESM pressurization system.

Selection of Functional Quorum Sensing Systems by Lysogenic Bacteriophages in Pseudomonas aeruginosa

Directory of Open Access Journals (Sweden)

Miguel A. Saucedo-Mora

2017-08-01

Full Text Available Quorum sensing (QS in Pseudomonas aeruginosa coordinates the expression of virulence factors, some of which are used as public goods. Since their production is a cooperative behavior, it is susceptible to social cheating in which non-cooperative QS deficient mutants use the resources without investing in their production. Nevertheless, functional QS systems are abundant; hence, mechanisms regulating the amount of cheating should exist. Evidence that demonstrates a tight relationship between QS and the susceptibility of bacteria against the attack of lytic phages is increasing; nevertheless, the relationship between temperate phages and QS has been much less explored. Therefore, in this work, we studied the effects of having a functional QS system on the susceptibility to temperate bacteriophages and how this affects the bacterial and phage dynamics. We find that both experimentally and using mathematical models, that the lysogenic bacteriophages D3112 and JBD30 select QS-proficient P. aeruginosa phenotypes as compared to the QS-deficient mutants during competition experiments with mixed strain populations in vitro and in vivo in Galleria mellonella, in spite of the fact that both phages replicate better in the wild-type background. We show that this phenomenon restricts social cheating, and we propose that temperate phages may constitute an important selective pressure toward the conservation of bacterial QS.

Real-time combustion control and diagnostics sensor-pressure oscillation monitor

Science.gov (United States)

Chorpening, Benjamin T [Morgantown, WV; Thornton, Jimmy [Morgantown, WV; Huckaby, E David [Morgantown, WV; Richards, George A [Morgantown, WV

2009-07-14

An apparatus and method for monitoring and controlling the combustion process in a combustion system to determine the amplitude and/or frequencies of dynamic pressure oscillations during combustion. An electrode in communication with the combustion system senses hydrocarbon ions and/or electrons produced by the combustion process and calibration apparatus calibrates the relationship between the standard deviation of the current in the electrode and the amplitudes of the dynamic pressure oscillations by applying a substantially constant voltage between the electrode and ground resulting in a current in the electrode and by varying one or more of (1) the flow rate of the fuel, (2) the flow rate of the oxidant, (3) the equivalence ratio, (4) the acoustic tuning of the combustion system, and (5) the fuel distribution in the combustion chamber such that the amplitudes of the dynamic pressure oscillations in the combustion chamber are calculated as a function of the standard deviation of the electrode current. Thereafter, the supply of fuel and/or oxidant is varied to modify the dynamic pressure oscillations.

A new glove-box system for a high-pressure tritium pump

International Nuclear Information System (INIS)

Wilson, S.W.; Borree, R.J.; Chambers, D.I.; Chang, Y.; Merrill, J.T.; Souers, P.C.; Wiggins, R.K.

1988-01-01

A new glove-box system that was designed around a high-pressure tritium pump is described. The system incorporates new containment ideas such as ''burpler'' passive pressure controls, valves that can be turned from outside the box, inflatable door seals, ferro-fluidic motor-shaft seals, and rapid box-to-hood conversion during cryostaging. Currently under construction, the system will contain nine separate sections with automatic pressure-balancing and venting systems. 3 refs., 5 figs

Temperature and pressure dependent osmotic pressure in liquid sodium-cesium alloys

International Nuclear Information System (INIS)

Rashid, R.I.M.A.

1987-01-01

The evaluation of the osmotic pressure in terms of the concentration fluctuations of mixtures and the equations of state of the pure liquids is considered. The temperature and pressure dependent experimentally measured concentration-concentration correlations in the long wavelength limit of liquid sodium-cesium alloys are used to demonstrate the appreciable dependence of the temperature and pressure on the osmotic pressure as a function of concentration. Introducing interchange energies as functions of temperature and pressure, our analysis is consistent with the Flory model. Thus, a formalism for evaluating the state dependent osmotic pressure is developed and our numerical work is considered to be an extension of the calculations of Rashid and March in the sense that a temperature and pressure dependent interchange energy parameter that more closely parameterizes the state dependent concentration fluctuations in the liquid alloys, is used. (author)

Relationship between systemic hemodynamics and ambulatory blood pressure level are sex dependent.

Science.gov (United States)

Alfie, J; Waisman, G D; Galarza, C R; Magi, M I; Vasvari, F; Mayorga, L M; Cámera, M I

1995-12-01

Sex-related differences in systemic hemodynamics were analyzed by means of cardiac index and systemic vascular resistance according to the level of daytime ambulatory blood pressure. In addition, we assessed the relations between ambulatory blood pressure measurements and systemic hemodynamics in male and female patients. We prospectively included 52 women and 53 men referred to our unit for evaluation of arterial hypertension. Women and men were grouped according to the level of daytime mean arterial pressure: or = 110 mm Hg. Patients underwent noninvasive evaluation of resting hemodynamics (impedance cardiography) and 24-hour ambulatory blood pressure monitoring. Compared with women men with lower daytime blood pressure had a 12% higher systemic vascular resistance index (P = NS) and a 14% lower cardiac index (P < .02), whereas men with higher daytime blood pressure had a 25% higher vascular resistance (P < .003) and a 21% lower cardiac index (P < .0004). Furthermore, in men systemic vascular resistance correlated positively with both daytime and nighttime systolic and diastolic blood pressures, whereas cardiac index correlated negatively only with daytime diastolic blood pressure. In contrast, women did not exhibit any significant correlation between hemodynamic parameters and ambulatory blood pressure measurements. In conclusion, sex-related differences in systemic hemodynamics were more pronounced in the group with higher daytime hypertension. The relations between systemic hemodynamics and ambulatory blood pressure level depended on the sex of the patient. In men a progressive circulatory impairment underlies the increasing level of ambulatory blood pressure, but this was not observed in women.

Validity and Usefulness of `Wearable Blood Pressure Sensing' for Detection of Inappropriate Short-Term Blood Pressure Variability in the Elderly

Science.gov (United States)

Iijima, Katsuya; Kameyama, Yumi; Akishita, Masahiro; Ouchi, Yasuyoshi; Yanagimoto, Shintaro; Imai, Yasushi; Yahagi, Naoki; Lopez, Guillaume; Shuzo, Masaki; Yamada, Ichiro

An increase in short-term blood pressure (BP) variability is a characteristic feature in the elderly. It makes the management of hemodynamics more difficult, because it is frequently seen disturbed baro-reflex function and increased arterial stiffness, leading to isolated systolic hypertension. Large BP variability aggravates hypertensive target organ damage and is an independent risk factor for the cardiovascular (CV) events in elderly hypertensive patients. Therefore, appropriate control in BP is indispensable to manage lifestyle-related diseases and to prevent subsequent CV events. In addition, accumulating recent reports show that excessive BP variability is also associated with a decline in cognitive function and fall in the elderly. In the clinical settings, we usually evaluate their health condition, mainly with single point BP measurement using cuff inflation. However, unfortunately we are not able to find the close changes in BP by the traditional way. Here, we can show our advantageous approach of continuous BP monitoring using newly developing device `wearable BP sensing' without a cuff stress in the elderly. The new device could reflect systolic BP and its detailed changes, in consistent with cuff-based BP measurement. Our new challenge suggests new possibility of its clinical application with high accuracy.

Two-Dimensional Fuzzy Sliding Mode Control of a Field-Sensed Magnetic Suspension System

Directory of Open Access Journals (Sweden)

Jen-Hsing Li

2014-01-01

Full Text Available This paper presents the two-dimensional fuzzy sliding mode control of a field-sensed magnetic suspension system. The fuzzy rules include both the sliding manifold and its derivative. The fuzzy sliding mode control has advantages of the sliding mode control and the fuzzy control rules are minimized. Magnetic suspension systems are nonlinear and inherently unstable systems. The two-dimensional fuzzy sliding mode control can stabilize the nonlinear systems globally and attenuate chatter effectively. It is adequate to be applied to magnetic suspension systems. New design circuits of magnetic suspension systems are proposed in this paper. ARM Cortex-M3 microcontroller is utilized as a digital controller. The implemented driver, sensor, and control circuits are simpler, more inexpensive, and effective. This apparatus is satisfactory for engineering education. In the hands-on experiments, the proposed control scheme markedly improves performances of the field-sensed magnetic suspension system.

Tourniquet pressures: strap width and tensioning system widths.

Science.gov (United States)

Wall, Piper L; Coughlin, Ohmar; Rometti, Mary; Birkholz, Sarah; Gildemaster, Yvonne; Grulke, Lisa; Sahr, Sheryl; Buising, Charisse M

2014-01-01

Pressure distribution over tourniquet width is a determinant of pressure needed for arterial occlusion. Different width tensioning systems could result in arterial occlusion pressure differences among nonelastic strap designs of equal width. Ratcheting Medical Tourniquets (RMTs; m2 inc., http://www.ratcheting buckles.com) with a 1.9 cm-wide (Tactical RMT) or 2.3 cm-wide (Mass Casualty RMT) ladder were directly compared (16 recipients, 16 thighs and 16 upper arms for each tourniquetx2). Then, RMTs were retrospectively compared with the windlass Combat Application Tourniquet (C-A-T ["CAT"], http://combattourniquet.com) with a 2.5 cm-wide internal tensioning strap. Pressure was measured with an air-filled No. 1 neonatal blood pressure cuff under each 3.8 cm-wide tourniquet. RMT circumferential pressure distribution was not uniform. Tactical RMT pressures were not higher, and there were no differences between the RMTs in the effectiveness, ease of use ("97% easy"), or discomfort. However, a difference did occur regarding tooth skipping of the pawl during ratchet advancement: it occurred in 1 of 64 Tactical RMT applications versus 27 of 64 Mass Casualty RMT applications. CAT and RMT occlusion pressures were frequently over 300 mmHg. RMT arm occlusion pressures (175-397 mmHg), however, were lower than RMT thigh occlusion pressures (197-562 mmHg). RMT effectiveness was better with 99% reached occlusion and 1% lost occlusion over 1 minute versus the CAT with 95% reached occlusion and 28% lost occlusion over 1 minute. RMT muscle tension changes (up to 232 mmHg) and pressure losses over 1 minute (24±11 mmHg arm under strap to 40±12 mmHg thigh under ladder) suggest more occlusion losses may have occurred if tourniquet duration was extended. The narrower tensioning system Tactical RMT has better performance characteristics than the Mass Casualty RMT. The 3.8 cm-wide RMTs have some pressure and effectiveness similarities and differences compared with the CAT. Clinically

Improvements in irrigation system modelling when using remotely sensed ET for calibration

Science.gov (United States)

van Opstal, J. D.; Neale, C. M. U.; Lecina, S.

2014-10-01

Irrigation system modelling is often used to aid decision-makers in the agricultural sector. It gives insight on the consequences of potential management and infrastructure changes. However, simulating an irrigation district requires a considerable amount of input data to properly represent the system, which is not easily acquired or available. During the simulation process, several assumptions have to be made and the calibration is usually performed only with flow measurements. The advancement of estimating evapotranspiration (ET) using remote sensing is a welcome asset for irrigation system modelling. Remotely-sensed ET can be used to improve the model accuracy in simulating the water balance and the crop production. This study makes use of the Ador-Simulation irrigation system model, which simulates water flows in irrigation districts in both the canal infrastructure and on-field. ET is estimated using an energy balance model, namely SEBAL, which has been proven to function well for agricultural areas. The seasonal ET by the Ador model and the ET from SEBAL are compared. These results determine sub-command areas, which perform well under current assumptions or, conversely, areas that need re-evaluation of assumptions and a re-run of the model. Using a combined approach of the Ador irrigation system model and remote sensing outputs from SEBAL, gives great insights during the modelling process and can accelerate the process. Additionally cost-savings and time-savings are apparent due to the decrease in input data required for simulating large-scale irrigation areas.

Pressure-sensing properties of single-walled carbon nanotubes covered with a corona-poled piezoelectric polymer

Energy Technology Data Exchange (ETDEWEB)

Ikawa, Takeshi; Tabata, Hiroshi, E-mail: tabata@eei.eng.osaka-u.ac.jp; Yoshizawa, Takeshi; Utaka, Ken; Kubo, Osamu; Katayama, Mitsuhiro [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

2016-07-18

Single-walled carbon nanotubes (SWNTs) have been studied extensively as sensing elements for chemical and biochemical sensors because of their excellent electrical properties, their ultrahigh ratio of surface area to volume, and the consequent extremely high sensitivity of their surface to the surrounding environment. The extremely high sensitivity indicates that SWNTs can operate as excellent transducers when combined with piezoelectric materials. In this paper, we present a touch sensor based on SWNT thin-film transistors (SWNT-TFTs) covered with a thin film of the piezoelectric polymer poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)). Devices were fabricated by spin-coating a P(VDF-TrFE) layer on an SWNT-TFT, which was followed by in situ corona poling to polarize the P(VDF-TrFE) layer. We studied the effect of the corona polarity on the device characteristics and revealed that poling with a negative corona discharge induced a large amount of hole doping in the SWNTs and improved the touch-sensing performance of the devices, while a positive discharge had a negligible effect. The poled devices exhibited regular, stable, and positive drain current modulation in response to intermittent pressing, and the response was proportional to the magnitude of the applied pressure, suggesting that it was caused by the piezoelectric effect of the polarized P(VDF-TrFE) layer. Furthermore, we also fabricated a device using horizontally aligned SWNTs with a lower SWNT density as an alternative transducer to an SWNT thin film, which demonstrated sensitivity as high as 70%/MPa.

A Silicon Carbide Wireless Temperature Sensing System for High Temperature Applications

Science.gov (United States)

Yang, Jie

2013-01-01

In this article, an extreme environment-capable temperature sensing system based on state-of-art silicon carbide (SiC) wireless electronics is presented. In conjunction with a Pt-Pb thermocouple, the SiC wireless sensor suite is operable at 450 °C while under centrifugal load greater than 1,000 g. This SiC wireless temperature sensing system is designed to be non-intrusively embedded inside the gas turbine generators, acquiring the temperature information of critical components such as turbine blades, and wirelessly transmitting the information to the receiver located outside the turbine engine. A prototype system was developed and verified up to 450 °C through high temperature lab testing. The combination of the extreme temperature SiC wireless telemetry technology and integrated harsh environment sensors will allow for condition-based in-situ maintenance of power generators and aircraft turbines in field operation, and can be applied in many other industries requiring extreme environment monitoring and maintenance. PMID:23377189

Quorum Sensing of Periodontal Pathogens

Directory of Open Access Journals (Sweden)

Darije Plančak

2015-01-01

Full Text Available The term ‘quorum sensing’ describes intercellular bacterial communication which regulates bacterial gene expression according to population cell density. Bacteria produce and secrete small molecules, named autoinducers, into the intercellular space. The concentration of these molecules increases as a function of population cell density. Once the concentration of the stimulatory threshold is reached, alteration in gene expression occurs. Gram-positive and Gram-negative bacteria possess different types of quorum sensing systems. Canonical LuxI/R-type/acyl homoserine lactone mediated quorum sensing system is the best studied quorum sensing circuit and is described in Gram-negative bacteria which employ it for inter-species communication mostly. Grampositive bacteria possess a peptide-mediated quorum sensing system. Bacteria can communicate within their own species (intra-species but also between species (inter-species, for which they employ an autoinducer-2 quorum sensing system which is called the universal language of the bacteria. Periodontal pathogenic bacteria possess AI-2 quorum sensing systems. It is known that they use it for regulation of biofilm formation, iron uptake, stress response and virulence factor expression. A better understanding of bacterial communication mechanisms will allow the targeting of quorum sensing with quorum sensing inhibitors to prevent and control disease.

Pressure suppression containment system for boiling water reactor

Science.gov (United States)

Gluntz, Douglas M.; Nesbitt, Loyd B.

1997-01-01

A system for suppressing the pressure inside the containment of a BWR following a postulated accident. A piping subsystem is provided which features a main process pipe that communicates the wetwell airspace to a connection point downstream of the guard charcoal bed in an offgas system and upstream of the main bank of delay charcoal beds which give extensive holdup to offgases. The main process pipe is fitted with both inboard and outboard containment isolation valves. Also incorporated in the main process pipe is a low-differential-pressure rupture disk which prevents any gas outflow in this piping whatsoever until or unless rupture occurs by virtue of pressure inside this main process pipe on the wetwell airspace side of the disk exceeding the design opening (rupture) pressure differential. The charcoal holds up the radioactive species in the noncondensable gas from the wetwell plenum by adsorption, allowing time for radioactive decay before the gas is vented to the environs.

Bi-Directional Brillouin Optical Time Domain Analyzer System for Long Range Distributed Sensing

Science.gov (United States)

Guo, Nan; Wang, Liang; Wang, Jie; Jin, Chao; Tam, Hwa-Yaw; Zhang, A. Ping; Lu, Chao

2016-01-01

We propose and experimentally demonstrate a novel scheme of bi-directional Brillouin time domain analyzer (BD-BOTDA) to extend the sensing range. By deploying two pump-probe pairs at two different wavelengths, the Brillouin frequency shift (BFS) distribution over each half of the whole fiber can be obtained with the simultaneous detection of Brillouin signals in both channels. Compared to the conventional unidirectional BOTDA system of the same sensing range, the proposed BD-BOTDA scheme enables distributed sensing with a performance level comparable to the conventional one with half of the sensing range and a spatial resolution of 2 m, while maintaining the Brillouin signal-to-noise ratio (SNR) and the BFS uncertainty. Based on this technique, we have achieved distributed temperature sensing with a measurement range of 81.9 km fiber at a spatial resolution of 2 m and BFS uncertainty of ~0.44 MHz without introducing any complicated components or schemes. PMID:27999250