A New Wide Frequency Band Capacitance Transducer with Application to Measuring Metal Fill Time

Directory of Open Access Journals (Sweden)

Wael DEABES

2009-01-01

Full Text Available A novel low cost, high frequency circuit for measuring capacitance is proposed in this paper. This new capacitance measuring circuit is able to measure small coupling capacitance variations with high stray-immunity. Hence, it could be used in many potential applications such as measuring the metal fill time in the Lost Foam Casting (LFC process and Electrical Capacitive Tomography (ECT system. The proposed circuit is based on differential charging/discharging method using current feedback amplifier and a synchronous demodulation stage. The circuit has a wide high frequency operating range with zero phase shift; hence multiple circuits can work at different frequencies simultaneously to measure the capacitance. The non-ideal characteristic of the circuit has been analyzed and the results verified through LTSpice simulation. Results from the tests on a prototype and a simulation elucidate the practicality of the proposed circuit.

Design and test of a capacitance detection circuit based on a transimpedance amplifier

International Nuclear Information System (INIS)

Mu Linfeng; Zhang Wendong; He Changde; Zhang Rui; Song Jinlong; Xue Chenyang

2015-01-01

This paper presents a transimpedance amplifier (TIA) capacitance detection circuit aimed at detecting micro-capacitance, which is caused by ultrasonic stimulation applied to the capacitive micro-machined ultrasonic transducer (CMUT). In the capacitance interface, a TIA is adopted to amplify the received signal with a center frequency of 400 kHz, and finally detect ultrasound pressure. The circuit has a strong anti-stray property and this paper also studies the calculation of compensation capacity in detail. To ensure high resolution, noise analysis is conducted. After optimization, the detected minimum ultrasound pressure is 2.1 Pa, which is two orders of magnitude higher than the former. The test results showed that the circuit was sensitive to changes in ultrasound pressure and the distance between the CMUT and stumbling block, which also successfully demonstrates the functionality of the developed TIA of the analog-front-end receiver. (paper)

Stray light reduction for Thomson scattering

NARCIS (Netherlands)

Bakker, L.P.; Kroesen, G.M.W.; Doebele, H.F.; Muraoka, K.

1999-01-01

In order to perform Thomson scattering in a gas discharge tube, the reduction of stray light is very important because of the very small Thomson cross-section. By introducing a sodium absorption cell as a notch filter, we can reduce the measured stray light considerably. Then we have to use a dye

Stray light characteristics of the diffractive telescope system

Science.gov (United States)

Liu, Dun; Wang, Lihua; Yang, Wei; Wu, Shibin; Fan, Bin; Wu, Fan

2018-02-01

Diffractive telescope technology is an innovation solution in construction of large light-weight space telescope. However, the nondesign orders of diffractive optical elements (DOEs) may affect the imaging performance as stray light. To study the stray light characteristics of a diffractive telescope, a prototype was developed and its stray light analysis model was established. The stray light characteristics including ghost, point source transmittance, and veiling glare index (VGI) were analyzed. During the star imaging test of the prototype, the ghost images appeared around the star image as the exposure time of the charge-coupled device improving, consistent with the simulation results. The test result of VGI was 67.11%, slightly higher than the calculated value 57.88%. The study shows that the same order diffraction of the diffractive primary lens and correcting DOE is the main factor that causes ghost images. The stray light sources outside the field of view can illuminate the image plane through nondesign orders diffraction of the primary lens and contributes to more than 90% of the stray light flux on the image plane. In summary, it is expected that these works will provide some guidance for optimizing the imaging performance of diffractive telescopes.

CMOS capacitive sensors for lab-on-chip applications a multidisciplinary approach

CERN Document Server

Ghafar-Zadeh, Ebrahim

2010-01-01

The main components of CMOS capacitive biosensors including sensing electrodes, bio-functionalized sensing layer, interface circuitries and microfluidic packaging are verbosely explained in chapters 2-6 after a brief introduction on CMOS based LoCs in Chapter 1. CMOS Capacitive Sensors for Lab-on-Chip Applications is written in a simple pedagogical way. It emphasises practical aspects of fully integrated CMOS biosensors rather than mathematical calculations and theoretical details. By using CMOS Capacitive Sensors for Lab-on-Chip Applications, the reader will have circuit design methodologies,

Modeling and Characterization of Capacitive Elements With Tissue as Dielectric Material for Wireless Powering of Neural Implants.

Science.gov (United States)

Erfani, Reza; Marefat, Fatemeh; Sodagar, Amir M; Mohseni, Pedram

2018-05-01

This paper reports on the modeling and characterization of capacitive elements with tissue as the dielectric material, representing the core building block of a capacitive link for wireless power transfer to neural implants. Each capacitive element consists of two parallel plates that are aligned around the tissue layer and incorporate a grounded, guarded, capacitive pad to mitigate the adverse effect of stray capacitances and shield the plates from external interfering electric fields. The plates are also coated with a biocompatible, insulating, coating layer on the inner side of each plate in contact with the tissue. A comprehensive circuit model is presented that accounts for the effect of the coating layers and is validated by measurements of the equivalent capacitance as well as impedance magnitude/phase of the parallel plates over a wide frequency range of 1 kHz-10 MHz. Using insulating coating layers of Parylene-C at a thickness of and Parylene-N at a thickness of deposited on two sets of parallel plates with different sizes and shapes of the guarded pad, our modeling and characterization results accurately capture the effect of the thickness and electrical properties of the coating layers on the behavior of the capacitive elements over frequency and with different tissues.

Influence of stray light for divertor spectroscopy in ITER

International Nuclear Information System (INIS)

Kajita, Shin; Veshchev, Evgeny; Lisgo, Steve; Barnsley, Robin; Morgan, Philip; Walsh, Michael; Ogawa, Hiroaki; Sugie, Tatsuo; Itami, Kiyoshi

2015-01-01

The influence of stray light in the divertor spectroscopy system in ITER is quantitatively investigated using a ray tracing simulation. Simulation results show that the stray light is negligible at positions in the divertor where the plasma emission is strong. However, it is also shown that the stray light can be significantly greater than the real signal if the plasma intensity is low. Deuterium and beryllium emissions are used for the assessment; for beryllium cases in particular, since the emission profile may be non-uniform in the divertor region, the influence of stray light can be non-negligible at some positions, e.g., above the divertor dome

ON THE INVERSION OF STOKES PROFILES WITH LOCAL STRAY-LIGHT CONTAMINATION

International Nuclear Information System (INIS)

Asensio Ramos, A.; Manso Sainz, R.

2011-01-01

Obtaining the magnetic properties of non-resolved structures in the solar photosphere is always challenging and problems arise because the inversion is carried out through the numerical minimization of a merit function that depends on the proposed model. We investigate the reliability of inversions in which the stray-light contamination is obtained from the same observations as a local average. In this case, we show that it is fundamental to include the covariance between the observed Stokes profiles and the stray-light contamination. The ensuing modified merit function of the inversion process penalizes large stray-light contaminations simply because of the presence of positive correlations between the observables and the stray light, fundamentally produced by spatially variable systematics. We caution that if the wrong merit function is used, artificially large stray-light contaminations might be inferred. Since this effect disappears if the stray-light contamination is obtained as an average over the full field of view, we recommend taking into account stray-light contamination using a global approach.

Energy Harvesting from the Stray Electromagnetic Field around the Electrical Power Cable for Smart Grid Applications.

Science.gov (United States)

Khan, Farid Ullah

For wireless sensor node (WSN) applications, this paper presents the harvesting of energy from the stray electromagnetic field around an electrical power line. Inductive and capacitive types of electrodynamic energy harvesters are developed and reported. For the produced energy harvesters, solid core and split-core designs are adopted. The inductive energy harvester comprises a copper wound coil which is produced on a mild steel core. However, the capacitive prototypes comprise parallel, annular discs separated by Teflon spacers. Moreover, for the inductive energy harvesters' wound coil and core, the parametric analysis is also performed. A Teflon housing is incorporated to protect the energy harvester prototypes from the harsh environmental conditions. Among the inductive energy harvesters, prototype-5 has performed better than the other harvesters and produces a maximum rms voltage of 908 mV at the current level of 155 A in the power line. However, at the same current flow, the capacitive energy harvesters produce a maximum rms voltage of 180 mV. The alternating output of the prototype-5 is rectified, and a super capacitor (1 F, 5.5 V) and rechargeable battery (Nickel-Cadmium, 3.8 V) are charged with it. Moreover, with the utilization of a prototype-5, a self-powered wireless temperature sensing and monitoring system for an electrical transformer is also developed and successfully implemented.

STRAY DOG DETECTION IN WIRED CAMERA NETWORK

Directory of Open Access Journals (Sweden)

C. Prashanth

2013-08-01

Full Text Available Existing surveillance systems impose high level of security on humans but lacks attention on animals. Stray dogs could be used as an alternative to humans to carry explosive material. It is therefore imperative to ensure the detection of stray dogs for necessary corrective action. In this paper, a novel composite approach to detect the presence of stray dogs is proposed. The captured frame from the surveillance camera is initially pre-processed using Gaussian filter to remove noise. The foreground object of interest is extracted utilizing ViBe algorithm. Histogram of Oriented Gradients (HOG algorithm is used as the shape descriptor which derives the shape and size information of the extracted foreground object. Finally, stray dogs are classified from humans using a polynomial Support Vector Machine (SVM of order 3. The proposed composite approach is simulated in MATLAB and OpenCV. Further it is validated with real time video feeds taken from an existing surveillance system. From the results obtained, it is found that a classification accuracy of about 96% is achieved. This encourages the utilization of the proposed composite algorithm in real time surveillance systems.

Prevalence of external ear disorders in Belgian stray cats.

Science.gov (United States)

Bollez, Anouck; de Rooster, Hilde; Furcas, Alessandra; Vandenabeele, Sophie

2018-02-01

Objectives Feline otitis externa is a multifactorial dermatological disorder about which very little is known. The objective of this study was to map the prevalence of external ear canal disorders and the pathogens causing otitis externa in stray cats roaming around the region of Ghent, Belgium. Methods One hundred and thirty stray cats were randomly selected during a local trap-neuter-return programme. All cats were European Shorthairs. This study included clinical, otoscopic and cytological evaluation of both external ears of each cat. Prospective data used as parameters in this study included the sex, age and body condition score of each cat, as well as the presence of nasal and/or ocular discharge, and the results of feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) Snap tests. Results Remarkably, very few (sub)clinical problems of the external ear canal were found in the stray cat population. Malassezia species was by far the most common organism found in the external ear canals of the 130 stray cats. A total of 96/130 (74%) cats were found to have Malassezia species organisms present in one or both ears based on the cytological examination. No correlation was found between the parameters of sex, age, body condition score, the presence of nasal and/or ocular discharge and FIV and FeLV status, and the presence of parasites, bacteria or yeasts. Conclusions and relevance This study provides more information about the normal state of the external ear canal of stray cats. The ears of most stray cats are relatively healthy. The presence of Malassezia species organisms in the external ear canal is not rare among stray cats.

Aerial firing and stray bullet injuries: a rising tide.

Science.gov (United States)

Ali, Syed Asad; Tahir, Syed Mohammad; Makhdoom, Asadullah; Shaikh, Abdul Razaque; Siddique, Akmal Jamal

2015-04-01

Aerial firing is shooting, using fire arm, into the air usually during a celebration. This observational study aimed to quantify magnitude and impact of stray bullet injuries by aerial firing at surgical emergencies of the Liaquat University Hospital (a university hospital), Hyderabad, Sindh, Pakistan from January 2009 to December 2010 (2 years). During the study period, 144 firearm injuries due to stray bullet reported to the A and E departments of the university hospital. All patients referred to surgical unit providing emergency cover on that day irrespective of the severity of the injury for medico-legal reasons. For this study, the cases were divided into those having trivial injury and do not require any active surgical intervention and those having serious injury mandating surgical intervention. One hundred and two cases of stray bullet injury sustained trivial injury and followed as outpatients after an overnight period of indoor hospitalization; however, 42 patients with stray bullet injuries requiring surgical intervention were hospitalized. The most common events leading to aerial firing and stray bullet injuries were marriage ceremonies, followed by a political rallies and New Year celebrations. Stray bullet injury also reported after aerial firing on cricket/hockey team victories, Pakistan Independence Day (14th August), cultural day in Sindh and Basant (Kite) festival in Punjab. The most frequent sites with serious stray bullet injury were chest (15), head and neck (10), abdomen (9) and limbs (8), respectively. Surgical interventions performed included chest intubation, exploration of wound tract to retrieve bullet if lodged superficially and was palpable, laparotomy to managed intra-abdominal injury, reduction of fracture site followed by reconstruction, flap reconstruction and graft for nonhealing wound. The mean duration of hospital stay was 19 days. No mortality was observed in this series of patients. We conclude that the prevalence of aerial

Monitoring dc stray current corrosion at sheet pile structures

NARCIS (Netherlands)

Peelen, W.H.A.; Neeft, E.A.C.; Leegwater, G.; Kanten-Roos, W. van; Courage, W.M.G.

2012-01-01

Steel is discarded by railway owners as a material for underground structures near railway lines, due to uncertainty over increased corrosion by DC stray currents stemming from the traction power system. This paper presents a large scale field test in which stray currents interference of a sheet

Stray light field dependence for large astronomical space telescopes

Science.gov (United States)

Lightsey, Paul A.; Bowers, Charles W.

2017-09-01

Future large astronomical telescopes in space will have architectures that expose the optics to large angular extents of the sky. Options for reducing stray light coming from the sky range from enclosing the telescope in a tubular baffle to having an open telescope structure with a large sunshield to eliminate solar illumination. These two options are considered for an on-axis telescope design to explore stray light considerations. A tubular baffle design will limit the sky exposure to the solid angle of the cone in front of the telescope set by the aspect ratio of the baffle length to Primary Mirror (PM) diameter. Illumination from this portion of the sky will be limited to the PM and structures internal to the tubular baffle. Alternatively, an open structure design will allow a large portion of the sky to directly illuminate the PM and Secondary Mirror (SM) as well as illuminating sunshield and other structure surfaces which will reflect or scatter light onto the PM and SM. Portions of this illumination of the PM and SM will be scattered into the optical train as stray light. A Radiance Transfer Function (RTF) is calculated for the open architecture that determines the ratio of the stray light background radiance in the image contributed by a patch of sky having unit radiance. The full 4π steradian of sky is divided into a grid of patches, with the location of each patch defined in the telescope coordinate system. By rotating the celestial sky radiance maps into the telescope coordinate frame for a given pointing direction of the telescope, the RTF may be applied to the sky brightness and the results integrated to get the total stray light from the sky for that pointing direction. The RTF data generated for the open architecture may analyzed as a function of the expanding cone angle about the pointing direction. In this manner, the open architecture data may be used to directly compare to a tubular baffle design parameterized by allowed cone angle based on the

Fast and accurate modeling of stray light in optical systems

Science.gov (United States)

Perrin, Jean-Claude

2017-11-01

The first problem to be solved in most optical designs with respect to stray light is that of internal reflections on the several surfaces of individual lenses and mirrors, and on the detector itself. The level of stray light ratio can be considerably reduced by taking into account the stray light during the optimization to determine solutions in which the irradiance due to these ghosts is kept to the minimum possible value. Unhappily, the routines available in most optical design software's, for example CODE V, do not permit all alone to make exact quantitative calculations of the stray light due to these ghosts. Therefore, the engineer in charge of the optical design is confronted to the problem of using two different software's, one for the design and optimization, for example CODE V, one for stray light analysis, for example ASAP. This makes a complete optimization very complex . Nevertheless, using special techniques and combinations of the routines available in CODE V, it is possible to have at its disposal a software macro tool to do such an analysis quickly and accurately, including Monte-Carlo ray tracing, or taking into account diffraction effects. This analysis can be done in a few minutes, to be compared to hours with other software's.

The Disturbing Effect of the Stray Magnetic Fields on Magnetoimpedance Sensors

Directory of Open Access Journals (Sweden)

Tao Wang

2016-10-01

Full Text Available The disturbing effect of the stray magnetic fields of Fe-based amorphous ribbons on the giant magnetoimpedance (GMI sensor has been investigated systematically in this paper. Two simple methods were used for examining the disturbing effect of the stray magnetic fields of ribbons on the GMI sensor. In order to study the influence of the stray magnetic fields on the GMI effect, the square-shaped amorphous ribbons were tested in front, at the back, on the left and on the top of a meander-line GMI sensor made up of soft ferromagnetic films, respectively. Experimental results show that the presence of ribbons in front or at the back of GMI sensor shifts the GMI curve to a lower external magnetic field. On the contrary, the presence of ribbons on the left or on the top of the GMI sensor shifts the GMI curve to a higher external magnetic field, which is related to the coupling effect of the external magnetic field and the stray magnetic fields. The influence of the area and angle of ribbons on GMI was also studied in this work. The GMI sensor exhibits high linearity for detection of the stray magnetic fields, which has made it feasible to construct a sensitive magnetometer for detecting the typical stray magnetic fields of general soft ferromagnetic materials.

The quality of stray radiation in the ovarian region in diagnostic X-ray examinations

International Nuclear Information System (INIS)

Ewen, K.; Fiebach, B.J.O.; Fischer, P.G.; Loehr, E.

1976-01-01

Dose measurements (LiF-TLD) and recordings of stray radiation spectra (Ge(Li)-Detectors) in a phantom show that shielding of the ovaries against stray radiation is advisable even though the effectivity of this measure decreases at higher tube voltages. The exposure of the ovaries to stray radiation increases with increasing tube voltage; the radiation quality of the stray radiation is, for the most part, independent of the filter value. (orig./AK) [de

Usage of ray tracing transfer matrix to mitigate the stray light for ITER spectroscopy

International Nuclear Information System (INIS)

Kajita, S.; Veshchev, E.; Barnsley, R.; Walsh, M.

2016-01-01

Stray light formed by the reflection of photons on inner wall from a bright divertor region can be a serious issue in spectroscopic measurement systems in ITER. In this study, we propose a method to mitigate the influence of stray light using a ray tracing analysis. Usually, a ray tracing simulation requires a time consuming runs. We constructed transfer matrices based on the ray tracing simulation results and used them to demonstrate the influence of stray light. It is shown that the transfer matrix can be used to reconstruct the emission profile by considering the influence of the stray light without any additional ray tracing runs. Mitigation of the stray light in ITER divertor impurity monitor was demonstrated, and a method of prediction of the stray light level for the scrape off layer spectroscopy from divertor region was proposed. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Conceptual design of Dump resistor for Superconducting CS of SST-1

Science.gov (United States)

Roy, Swati; Raj, Piyush; Panchal, Arun; Pradhan, Subrata

2017-04-01

Under upgradation activities for SST-1, the existing resistive central solenoid (CS) coil will be replaced with Nb3Sn based superconducting coil. Design of Central solenoid had been completed and some of the initiative has already taken for its manufacturing. The superconducting CS will store upto 3 MJ of magnetic energy per operation cycle with operating current upto 14 kA. During quench, energy stored in the coils has to be extracted rapidly with a time constant of 1.5 s by inserting a 20 mΩ dump resistor in series with the superconducting CS which is normally shorted by circuit breakers. As a critical part of the superconducting CS quench protection system, a conceptual design of the 20 mΩ dump resistor has been proposed. The required design aspects and a dimensional layout of the dump resistor for the new superconducting CS has been presented and discussed. The basic structure of the proposed dump resistor comprises of stainless steel grids connected in series in the form of meander to minimize the stray inductance and increase the surface area for cooling. Such an array of grids connected in series and parallel will cater to the electrical as well as thermal parameters. It will be cooled by natural convection. During operation, the estimated maximum temperature of the proposed dump resistor will raise upto 600 K.

Identification and mitigation of stray laser light in the Thomson scattering system on the Madison Symmetric Torus (MST)

Energy Technology Data Exchange (ETDEWEB)

Jacobson, C. M., E-mail: cjacobson@wisc.edu; Borchardt, M. T.; Den Hartog, D. J.; Falkowski, A. F.; Morton, L. A.; Thomas, M. A. [Department of Physics, University of Wisconsin–Madison, 1150 University Avenue, Madison, Wisconsin 53706 (United States)

2016-11-15

The Thomson scattering diagnostic on the Madison Symmetric Torus (MST) records excessive levels of stray Nd:YAG laser light. Stray light saturates the 1064 nm spectral channel in all polychromators, which prevents absolute electron density measurements via Rayleigh scattering calibration. Furthermore, stray light contaminates adjacent spectral channels for r/a ≥ 0.75, which renders the diagnostic unable to make electron temperature measurements at these radii. In situ measurements of stray light levels during a vacuum vessel vent are used to identify stray light sources and strategies for reduction of stray light levels. Numerical modeling using Zemax OpticStudio supports these measurements. The model of the vacuum vessel and diagnostic includes synthetic collection optics to enable direct comparison of measured and simulated stray light levels. Modeling produces qualitatively similar stray light distributions to MST measurements, and quantifies the mitigation effects of stray light mitigation strategies prior to implementation.

Identification and mitigation of stray laser light in the Thomson scattering system on the Madison Symmetric Torus (MST)

International Nuclear Information System (INIS)

Jacobson, C. M.; Borchardt, M. T.; Den Hartog, D. J.; Falkowski, A. F.; Morton, L. A.; Thomas, M. A.

2016-01-01

The Thomson scattering diagnostic on the Madison Symmetric Torus (MST) records excessive levels of stray Nd:YAG laser light. Stray light saturates the 1064 nm spectral channel in all polychromators, which prevents absolute electron density measurements via Rayleigh scattering calibration. Furthermore, stray light contaminates adjacent spectral channels for r/a ≥ 0.75, which renders the diagnostic unable to make electron temperature measurements at these radii. In situ measurements of stray light levels during a vacuum vessel vent are used to identify stray light sources and strategies for reduction of stray light levels. Numerical modeling using Zemax OpticStudio supports these measurements. The model of the vacuum vessel and diagnostic includes synthetic collection optics to enable direct comparison of measured and simulated stray light levels. Modeling produces qualitatively similar stray light distributions to MST measurements, and quantifies the mitigation effects of stray light mitigation strategies prior to implementation.

Anomalous effects on radiation detectors and capacitance measurements inside a modified Faraday cage

Science.gov (United States)

Milián-Sánchez, V.; Mocholí-Salcedo, A.; Milián, C.; Kolombet, V. A.; Verdú, G.

2016-08-01

We present experimental results showing certain anomalies in the measurements performed inside a modified Faraday cage of decay rates of Ra-226, Tl-204 and Sr-90/I-90, of the gamma spectrum of a Cs-137 preparation, and of the capacitance of both a class-I multilayer ceramic capacitor and of the interconnection cable between the radiation detector and the scaler. Decay rates fluctuate significantly up to 5% around the initial value and differently depending on the type of nuclide, and the spectrum photopeak increases in 4.4%. In the case of the capacitor, direct capacitance measurements at 100 Hz, 10 kHz and 100 kHz show variations up to 0.7%, the most significant taking place at 100 Hz. In the case of the interconnection cable, the capacitance varies up to 1%. Dispersion also tends to increase inside the enclosure. However, the measured capacitance variations do not explain the variations observed in decay rates.

Stray energy transfer during endoscopy.

Science.gov (United States)

Jones, Edward L; Madani, Amin; Overbey, Douglas M; Kiourti, Asimina; Bojja-Venkatakrishnan, Satheesh; Mikami, Dean J; Hazey, Jeffrey W; Arcomano, Todd R; Robinson, Thomas N

2017-10-01

Endoscopy is the standard tool for the evaluation and treatment of gastrointestinal disorders. While the risk of complication is low, the use of energy devices can increase complications by 100-fold. The mechanism of increased injury and presence of stray energy is unknown. The purpose of the study was to determine if stray energy transfer occurs during endoscopy and if so, to define strategies to minimize the risk of energy complications. A gastroscope was introduced into the stomach of an anesthetized pig. A monopolar generator delivered energy for 5 s to a snare without contacting tissue or the endoscope itself. The endoscope tip orientation, energy device type, power level, energy mode, and generator type were varied to mimic in vivo use. The primary outcome (stray current) was quantified as the change in tissue temperature (°C) from baseline at the tissue closest to the tip of the endoscope. Data were reported as mean ± standard deviation. Using the 60 W coag mode while changing the orientation of the endoscope tip, tissue temperature increased by 12.1 ± 3.5 °C nearest the camera lens (p energy transfer (p = 0.04 and p = 0.002, respectively) as did utilizing the low-voltage cut mode (6.6 ± 0.5 °C, p energy transfer compared to a standard generator (1.5 ± 3.5 °C vs. 9.5 ± 0.8 °C, p energy is transferred within the endoscope during the activation of common energy devices. This could result in post-polypectomy syndrome, bleeding, or perforation outside of the endoscopist's view. Decreasing the power, utilizing low-voltage modes and/or an impedance-monitoring generator can decrease the risk of complication.

A method to measure internal stray radiation of cryogenic infrared imaging systems under various ambient temperatures

Science.gov (United States)

Tian, Qijie; Chang, Songtao; Li, Zhou; He, Fengyun; Qiao, Yanfeng

2017-03-01

The suppression level of internal stray radiation is a key criterion for infrared imaging systems, especially for high-precision cryogenic infrared imaging systems. To achieve accurate measurement for internal stray radiation of cryogenic infrared imaging systems under various ambient temperatures, a measurement method, which is based on radiometric calibration, is presented in this paper. First of all, the calibration formula is deduced considering the integration time, and the effect of ambient temperature on internal stray radiation is further analyzed in detail. Then, an approach is proposed to measure the internal stray radiation of cryogenic infrared imaging systems under various ambient temperatures. By calibrating the system under two ambient temperatures, the quantitative relation between the internal stray radiation and the ambient temperature can be acquired, and then the internal stray radiation of the cryogenic infrared imaging system under various ambient temperatures can be calculated. Finally, several experiments are performed in a chamber with controllable inside temperatures to evaluate the effectiveness of the proposed method. Experimental results indicate that the proposed method can be used to measure internal stray radiation with high accuracy at various ambient temperatures and integration times. The proposed method has some advantages, such as simple implementation and the capability of high-precision measurement. The measurement results can be used to guide the stray radiation suppression and to test whether the internal stray radiation suppression performance meets the requirement or not.

Anomalous effects on radiation detectors and capacitance measurements inside a modified Faraday cage

Energy Technology Data Exchange (ETDEWEB)

Milián-Sánchez, V., E-mail: vicmisan@iqn.upv.es [Institute for Industrial, Radiophysical and Environmental Safety, Universitat Politècnica de València, Camino de Vera, s/n, Valencia (Spain); Mocholí-Salcedo, A., E-mail: amocholi@eln.upv.es [Traffic Control Systems Group, ITACA Institute, Universitat Politécnica de, Camino de Vera, s/n, Valencia (Spain); Milián, C., E-mail: carles.milian@cpht.polytechnique.fr [Centre de Physique Théorique, CNRS, École Polytechnique, F-91128 Palaiseau (France); Kolombet, V.A., E-mail: kolombet@iteb.ru [Institute of Theoretical and Experimental Biophysics, Russian Academy of Science, Moscow Region, Pushchino 142290 (Russian Federation); Verdú, G., E-mail: gverdu@iqn.upv.es [Institute for Industrial, Radiophysical and Environmental Safety, Universitat Politècnica de València, Camino de Vera, s/n, Valencia (Spain); Chemical and Nuclear Engineering Department, Universitat Politécnica de Valencia, Camino de Vera, s/n, Valencia (Spain)

2016-08-21

We present experimental results showing certain anomalies in the measurements performed inside a modified Faraday cage of decay rates of Ra-226, Tl-204 and Sr-90/I-90, of the gamma spectrum of a Cs-137 preparation, and of the capacitance of both a class-I multilayer ceramic capacitor and of the interconnection cable between the radiation detector and the scaler. Decay rates fluctuate significantly up to 5% around the initial value and differently depending on the type of nuclide, and the spectrum photopeak increases in 4.4%. In the case of the capacitor, direct capacitance measurements at 100 Hz, 10 kHz and 100 kHz show variations up to 0.7%, the most significant taking place at 100 Hz. In the case of the interconnection cable, the capacitance varies up to 1%. Dispersion also tends to increase inside the enclosure. However, the measured capacitance variations do not explain the variations observed in decay rates. - Highlights: • Background counts and decay rates changes of different nuclides are described. • Those changes are observed inside a multilayer modified Faraday cage. • Noise in a multichannel analyzer increases inside the multilayer enclosure. • Capacitance of a class-I multilayer ceramic capacitor varies inside the enclosure. • Capacitance changes depend on the used frequency.

Anomalous effects on radiation detectors and capacitance measurements inside a modified Faraday cage

International Nuclear Information System (INIS)

Milián-Sánchez, V.; Mocholí-Salcedo, A.; Milián, C.; Kolombet, V.A.; Verdú, G.

2016-01-01

We present experimental results showing certain anomalies in the measurements performed inside a modified Faraday cage of decay rates of Ra-226, Tl-204 and Sr-90/I-90, of the gamma spectrum of a Cs-137 preparation, and of the capacitance of both a class-I multilayer ceramic capacitor and of the interconnection cable between the radiation detector and the scaler. Decay rates fluctuate significantly up to 5% around the initial value and differently depending on the type of nuclide, and the spectrum photopeak increases in 4.4%. In the case of the capacitor, direct capacitance measurements at 100 Hz, 10 kHz and 100 kHz show variations up to 0.7%, the most significant taking place at 100 Hz. In the case of the interconnection cable, the capacitance varies up to 1%. Dispersion also tends to increase inside the enclosure. However, the measured capacitance variations do not explain the variations observed in decay rates. - Highlights: • Background counts and decay rates changes of different nuclides are described. • Those changes are observed inside a multilayer modified Faraday cage. • Noise in a multichannel analyzer increases inside the multilayer enclosure. • Capacitance of a class-I multilayer ceramic capacitor varies inside the enclosure. • Capacitance changes depend on the used frequency.

Conceptual design of dump resistor for superconducting CS of SST-1

International Nuclear Information System (INIS)

Roy, Swati; Pradhan, Subrata; Panchal, Arun

2015-01-01

During the upgradation of SST-1, the resistive central solenoid (CS) coil has been planned to be replaced with Nb 3 Sn based superconducting coil. The superconducting CS will store upto 3.5MJ of magnetic energy per operation cycle with operating current upto 14kA. In case of coil quench, the energy stored in the coils is to be extracted rapidly with a time constant of 1.5s. This will be achieved by inserting a 20m Ohm dump resistor in series with the superconducting CS which is normally shorted by circuit breakers. As a vital part of the superconducting CS quench protection system, a conceptual design of the 20m Ohm dump resistor has been proposed. In this paper, the required design aspects and a dimensional layout of the dump resistor for the new superconducting CS has been presented. Natural air circulation is proposed as cooling method for this dump resistor. The basic structure of the proposed dump resistor comprises of stainless steel grids connected in series in the shape of meander to minimize the stray inductance and increase the surface area for cooling. The entire dump resistor will be an array of such grids connected in series and parallel to meet electrical as well as thermal parameters. The maximum temperature of the proposed dump resistor is upto 350 °C during dump 3.5MJ energy. The proposed design permits indigenous fabrication of the dump resistor using commercially available welding techniques. (author)

A novel capacitive micro-accelerometer with grid strip capacitances and sensing gap alterable capacitances

International Nuclear Information System (INIS)

Dong Linxi; Chen Jindan; Huo Weihong; Li Yongjie; Sun Lingling; Yan Haixia

2009-01-01

The comb capacitances fabricated by deep reactive ion etching (RIE) process have high aspect ratio which is usually smaller than 30: 1 for the complicated process factors, and the combs are usually not parallel due to the well-known micro-loading effect and other process factors, which restricts the increase of the seismic mass by increasing the thickness of comb to reduce the thermal mechanical noise and the decrease of the gap of the comb capacitances for increasing the sensitive capacitance to reduce the electrical noise. Aiming at the disadvantage of the deep RIE, a novel capacitive micro-accelerometer with grid strip capacitances and sensing gap alterable capacitances is developed. One part of sensing of inertial signal of the micro-accelerometer is by the grid strip capacitances whose overlapping area is variable and which do not have the non-parallel plate's effect caused by the deep RIE process. Another part is by the sensing gap alterable capacitances whose gap between combs can be reduced by the actuators. The designed initial gap of the alterable comb capacitances is relatively large to depress the effect of the maximum aspect ratio (30 : 1) of deep RIE process. The initial gap of the capacitance of the actuator is smaller than the one of the comb capacitances. The difference between the two gaps is the initial gap of the sensitive capacitor. The designed structure depresses greatly the requirement of deep RIE process. The effects of non-parallel combs on the accelerometer are also analyzed. The characteristics of the micro-accelerometer are discussed by field emission microscopy (FEM) tool ANSYS. The tested devices based on slide-film damping effect are fabricated, and the tested quality factor is 514, which shows that grid strip capacitance design can partly improve the resolution and also prove the feasibility of the designed silicon-glass anodically bonding process.

The impact of microwave stray radiation to in-vessel diagnostic components

Energy Technology Data Exchange (ETDEWEB)

Hirsch, M.; Laqua, H. P.; Hathiramani, D.; Baldzuhn, J.; Biedermann, C.; Cardella, A.; Erckmann, V.; König, R.; Köppen, M.; Zhang, D. [Max-Planck-Institut für Plasmaphysik, Teilinstitut Greifswald, EURATOM Association, D-17489 Greifswald (Germany); Oosterbeek, J.; Brand, H. von der; Parquay, S. [Technische Universiteit Eindhoven, department Technische Natuurkunde, working group for Plasma Physics and Radiation Technology, Den Doelch 2, 5612 AZ Eindhoven (Netherlands); Jimenez, R. [Centro de Investigationes Energeticas, Medioambientales y Technológicas, Association EURATOM/CIEMAT, Avenida Complutense 22, Madrid 28040 (Spain); Collaboration: W7-X Teasm

2014-08-21

Microwave stray radiation resulting from unabsorbed multiple reflected ECRH / ECCD beams may cause severe heating of microwave absorbing in-vessel components such as gaskets, bellows, windows, ceramics and cable insulations. In view of long-pulse operation of WENDELSTEIN-7X the MIcrowave STray RAdiation Launch facility, MISTRAL, allows to test in-vessel components in the environment of isotropic 140 GHz microwave radiation at power load of up to 50 kW/m{sup 2} over 30 min. The results show that both, sufficient microwave shielding measures and cooling of all components are mandatory. If shielding/cooling measures of in-vessel diagnostic components are not efficient enough, the level of stray radiation may be (locally) reduced by dedicated absorbing ceramic coatings on cooled structures.

Stray current monitoring at Nuremberg subway; Streustromueberwachung bei der U-Bahn Nuernberg

Energy Technology Data Exchange (ETDEWEB)

Altmann, M.; Halfmann, U.; Schneider, E. [Siemens AG, Erlangen (Germany). TS EL EN 2; Roesch, N. [VAG Verkehrs-AG Nuernberg, FA/SA - Starkstromanlagen, Nuernberg (Germany)

2004-05-01

Operating DC traction systems requires protective measures against the effects of stray currents. Damage by corrosion could occur both at railway and third party installations. The continuous effectiveness of protective measures needs to be monitored and recorded during revenue operation, and shall be capable to be demonstrated to supervising authorities. Measuring the rail-to-earth potential within the traction network under operational conditions, combined with centralized analysis, visualization, signaling and archiving is a straightforward and efficient method of stray current monitoring. For more than one year, the stray current monitoring system SITRAS SMS {sup registered} has been undergoing successful field application at the Nuremberg Subway. (orig.)

[Influence of different multifocal intraocular lens concepts on retinal stray light parameters].

Science.gov (United States)

Ehmer, A; Rabsilber, T M; Mannsfeld, A; Sanchez, M J; Holzer, M P; Auffarth, G U

2011-10-01

Multifocal intraocular lenses (MIOL) are known to induce various photic phenomena depending on the optical principle. The aim of this study was to investigate the correlation between stray light measurements performed with the C-Quant (Oculus, Germany) and the results of a subjective patient questionnaire. In this study three different MIOLs were compared: AMO ReZoom (refractive design, n=10), AMO ZM900 (diffractive design, n=10) and Oculentis Mplus (near segment design, n=10). Cataract and refractive patients were enrolled in the study. Functional results were evaluated at least 3 months postoperatively followed by stray light measurements and a subjective questionnaire. Surgery was performed for all patients without complications. The three groups were matched for age, IOL power and corrected distance visual acuity (CDVA). Significantly different stray light (median) values log(s) were found (Kruskal-Wallis test, p<0.05): 1.12 log (refractive), 1.13 log (segment) and 1.28 log (diffractive). The subjective questionnaire did not show differences in glare perception but refractive MIOL patients noticed more halos surrounding light sources than the diffractive and segment MIOL patients. Stray light and subjective photopic phenomena do not show any basic correlation. Measurements in patients with refractive MIOLs showed less stray light than near segment or diffractive MIOLs. However, refractive MIOLs induced more halos compared to the other groups analyzed.

A degradation model for stray current induced corrosion in underground reinforced concrete structures

NARCIS (Netherlands)

Polder, R.B.; Peelen, W.H.A.

2003-01-01

This paper describes the effects of stray currents on durability and reinforcement corrosion of underground concrete structures. Cathodic protection of underground pipelines are stationary sources of stray current interference with concrete, and rail traction systems are non-stationary sources. The

Electrolytic corrosion of water pipeline system in the remote distance from stray currents—Case study

Directory of Open Access Journals (Sweden)

Krzysztof Zakowski​

2016-06-01

Full Text Available Case study of corrosion failure of urban water supply system caused by the harmful effects of stray currents was presented. The failure occurred at a site distant from the sources of these currents namely the tramway and railway traction systems. Diagnosis revealed the stray currents flow to pipeline over a remote distance of 800/1000 m from the point of failure. At the point of failure stray currents flowed from the pipeline to the ground through external insulation defects, causing the process of electrolytic corrosion of the metal. Long distance between the affected section of the pipeline and the sources of stray currents excludes the typical protection against stray currents in the form of electrical polarized drainage. Corrosion protection at this point can be achieved by using the earthing electrodes made of magnesium, which will also provide cathodic current protection as galvanic anode.

Stray radiation and the Infrared Astronomical Satellite /IRAS/ telescope

Science.gov (United States)

Noll, R. J.; Harned, R.; Breault, R. P.; Malugin, R.

1981-01-01

Stray light control is a major consideration in the design of infrared cryogenically cooled telescopes such as the Infrared Astronomical Satellite (IRAS). The basic design of the baffle system, and the placement, shape, and coating of the secondary support struts for the telescope subsystem are described. The intent of this paper is to highlight the stray light problems encountered while designing the system, and to illustrate how computer analysis can be a useful design aid. Scattering measurements of the primary mirror, and a full system level scatter measurement are presented. Comparisons of predicted performance with the measured results are also presented.

A survey of gastrointestinal helminth of stray dogs in Zabol city, southeastern of Iran

Directory of Open Access Journals (Sweden)

Geraili, A.

2016-03-01

Full Text Available Canids are reservoir for some zoonoses helminthic disease. They are one of main public health problem. The aim of this study was to ascertain frequency of gastrointestinal helminthic infection of stray dogs in Zabol city, southeaster of Iran. In this descriptive study, 30 stray dogs were euthanized, intestine was removed by necropsy. Then, the intestines was opened by scalpel and their contents passed through mesh sieve. The helminth were collected. The nematodes were preserved in 70% ethanol with 5% glycerin and cestodes were preserved in 70% ethanol. The cestodes were stained by acetocarmine. The nematodes were cleared by lactophenol. The genus and species of helminth were identified by identification keys. Twenty two (73.3% of stray dogs had at least one intestinal helminthic infection. Recovered helminth from stray dogs include: Taenia hydatigena (53.3%, Taenia ovis (20%, Taenia multiceps (6.6%, Mesocestoides spp (10%, Toxocara canis (23.3%, Toxocara cati (3.3%. Data showed that the stray dogs in Zabol city harbor some important zoonoses helminth parasite like Toxocara.

Detecting stray microwaves and nonequilibrium quasiparticles in thin films by single-electron tunneling

Science.gov (United States)

Saira, Olli-Pentti; Maisi, Ville; Kemppinen, Antti; Möttönen, Mikko; Pekola, Jukka

2013-03-01

Superconducting thin films and tunnel junctions are the building blocks of many state-of-the-art technologies related to quantum information processing, microwave detection, and electronic amplification. These devices operate at millikelvin temperatures, and - in a naive picture - their fidelity metrics are expected to improve as the temperature is lowered. However, very often one finds in the experiment that the device performance levels off around 100-150 mK. In my presentation, I will address three common physical mechanisms that can cause such saturation: stray microwaves, nonequilibrium quasiparticles, and sub-gap quasiparticle states. The new experimental data I will present is based on a series of studies on quasiparticle transport in Coulomb-blockaded normal-insulator-superconductor tunnel junction devices. We have used a capacitively coupled SET electrometer to detect individual quasiparticle tunneling events in real time. We demonstrate the following record-low values for thin film aluminum: quasiparticle density nqp < 0 . 033 / μm3 , normalized density of sub-gap quasiparticle states (Dynes parameter) γ < 1 . 6 ×10-7 . I will also discuss some sample stage and chip designs that improve microwave shielding.

Stray-electron accumulation and effects in HIF accelerators

International Nuclear Information System (INIS)

Cohen, R.H.; Friedman, A.; Furman, M.A.; Lund, S.M.; Molvik, A.W.; Stoltz, P.; Vay, J.-L.

2003-01-01

Stray electrons can be introduced in positive-charge accelerators for heavy ion fusion (or other applications) as a result of ionization of ambient gas or gas released from walls due to halo-ion impact, or as a result of secondary-electron emission. Electron accumulation is impacted by the ion beam potential, accelerating fields, multipole magnetic fields used for beam focus, and the pulse duration. We highlight the distinguishing features of heavy-ion accelerators as they relate to stray-electron issues, and present first results from a sequence of simulations to characterize the electron cloud that follows from realistic ion distributions. Also, we present ion simulations with prescribed random electron distributions, undertaken to begin to quantify the effects of electrons on ion beam quality

Experimental observations of stray current effects on steel fibres embedded in mortar

DEFF Research Database (Denmark)

Solgaard, A.O.S.; Carsana, M.; Geiker, M.R.

2013-01-01

It is known that stray direct current can cause corrosive damage over time to bar reinforced concrete, but knowledge on the consequences to steel fibre reinforced concrete is limited. This paper presents analyses and corresponding results from an experimental program (parametric study) investigat......It is known that stray direct current can cause corrosive damage over time to bar reinforced concrete, but knowledge on the consequences to steel fibre reinforced concrete is limited. This paper presents analyses and corresponding results from an experimental program (parametric study......) investigating the conditions required for current to be picked up by embedded steel fibres or reinforcement (rebars). The experiments showed that there is a clear ‘length effect’ related to the susceptibility of stray current being picked up by embedded steel (fibres or rebars): the shorter the reinforcement...

Stray dog and cat laws and enforcement in Czech Republic and in Italy

Directory of Open Access Journals (Sweden)

Eva Voslářvá

2012-01-01

Full Text Available The growing numbers of stray dogs and cats have posed serious public-health, socioeconomic, political and animal-welfare problems in many EU countries. Stray animal population control is a complex issue and there are no easy solutions. Recognising the importance of the issue the European Commission has, since 2007, actively contributed to the elaboration of the first global welfare standards for the control of dog populations in the framework of the World Organisation for Animal Health (OIE. Problem-solving approaches vary in different countries as there is no common European Community legislation dealing with stray animal control. In this paper the authors describe the characteristics of the stray dog and cat problem in general and focus on existing European legislation. A comparative overview of policies and measures in place in the Czech Republic and in Italy is made to observe the differences between the two countries and understand the different needs in each, considering their historical and social differences (i.e. a post-communist eastern country vs a western country and founder member of what is now the European Union.

Searching for O-X-B mode-conversion window with monitoring of stray microwave radiation in LHD

International Nuclear Information System (INIS)

Igami, H.; Kubo, S.; Laqua, H. P.; Nagasaki, K.; Inagaki, S.; Notake, T.; Shimozuma, T.; Yoshimura, Y.; Mutoh, T.; LHD Experimental Group

2006-01-01

In the Large Helical Device, the stray microwave radiation is monitored by using so-called sniffer probes during electron cyclotron heating. In monitoring the stray radiation, we changed the microwave beam injection angle and search the O-X-B mode-conversion window to excite electron Bernstein waves (EBWs). When the microwave beam is injected toward the vicinity of the predicted O-X-B mode-conversion window, the electron temperature rises in the central part of overdense plasmas. In that case, the stray radiation level near the injection antenna becomes low. These results indicate that monitoring the stray radiation near the injection antenna is helpful in confirming the effectiveness of excitation of EBWs simply without precise analysis

Experimental validation of a method for removing the capacitive leakage artifact from electrical bioimpedance spectroscopy measurements

International Nuclear Information System (INIS)

Buendia, R; Seoane, F; Gil-Pita, R

2010-01-01

Often when performing electrical bioimpedance (EBI) spectroscopy measurements, the obtained EBI data present a hook-like deviation, which is most noticeable at high frequencies in the impedance plane. The deviation is due to a capacitive leakage effect caused by the presence of stray capacitances. In addition to the data deviation being remarkably noticeable at high frequencies in the phase and the reactance spectra, the measured EBI is also altered in the resistance and the modulus. If this EBI data deviation is not properly removed, it interferes with subsequent data analysis processes, especially with Cole model-based analyses. In other words, to perform any accurate analysis of the EBI spectroscopy data, the hook deviation must be properly removed. Td compensation is a method used to compensate the hook deviation present in EBI data; it consists of multiplying the obtained spectrum, Z meas (ω), by a complex exponential in the form of exp(–jωTd). Although the method is well known and accepted, Td compensation cannot entirely correct the hook-like deviation; moreover, it lacks solid scientific grounds. In this work, the Td compensation method is revisited, and it is shown that it should not be used to correct the effect of a capacitive leakage; furthermore, a more developed approach for correcting the hook deviation caused by the capacitive leakage is proposed. The method includes a novel correcting expression and a process for selecting the proper values of expressions that are complex and frequency dependent. The correctness of the novel method is validated with the experimental data obtained from measurements from three different EBI applications. The obtained results confirm the sufficiency and feasibility of the correcting method

Seroepidemiological survey of helminthic parasites of stray dogs in Sari City, northern Iran.

Science.gov (United States)

Gholami, Ishirzad; Daryani, Ahmad; Sharif, Mehdi; Amouei, Afsaneh; Mobedi, Iraj

2011-01-15

The objective of this study was to determine the prevalence rate of helminthic parasites in stray dogs' population especially zoonotic infections and to identify potential risk factors in the different areas of Sari city in Caspian area, north of Iran. During the period from April to September 2007, 50 stray dogs were collected from urban areas of Sari city. Recovered parasites were fixed in alcohol and stained by carmine then observed by microscope. The taxonomic study was carried out by measuring different parts of the body of helminthes and statistical tests were performed using the Chi-square test. A total of 27 adult and 23 juvenile stray dogs were collected and the overall prevalence rate of infection was 90%. The three most common helminthes were Toxocara canis (60%), Ancylostoma caninum (46%) and Dipylidium caninum (36%). Other parasites were Uncinaria stenocephala (12%), Taenia hydatigena (6%), Spirocerca lupi (6%), Dirofilaria immitis (6%), Toxascaris leonina (2%), Rictularia sp. (2%), Taenia ovis (2%) and Taenia taeniformis (2%). Five species of zoonotic helminthes recovered were T. canis, A. caninum, U. stenocephala, D. caninum and D. immitis. Hookworm infections (58%) were more common significantly in the young stray dogs (p caninum, T. canis and U. stenocephala, there was significant difference between juvenile and adult dogs (p < 0.05). The results highlight the potential role of stray dogs for transmission of helminthic parasites particularly zoonotic parasites that are a significant risk to human health.

WIDESPREAD OF STRAY DOGS: METHODS FOR SOLVING THE PROBLEM IN CERTAIN REGIONS OF BOSNIA AND HERZEGOVINA

OpenAIRE

Muhamed Katica; Nedzad Gradascevic; Nejra Hadzimusic; Zarema Obradovic; Ramo Mujkanovic; Esad Mestric; Senad Coloman; Muhamed Dupovac

2017-01-01

Stray dogs are the ones not microchipped, which live across the streets and other public surfaces unattended, and so represent a serious public-health problem. Lack of human support for the stray dogs causes a range of problems - from territorial status to ensuring food. Such conditions force them to activate a self-preservation mechanism and return to natural behavioral patterns. Regarding the fact that several thousands of stray dogs were recorded in observed regions of Bosnia and Herze...

Pitfalls and artifacts in measuring absorption spectra and kinetics: the effect of stray light in the UV and red regions

International Nuclear Information System (INIS)

Czapski, Gideon; Ozeri, Yair; Goldstein, Sara

2005-01-01

Effects of stray light on absorption spectrum and kinetics are discussed. The extent of the stray light depends on the light source, monochromator, wavelength set by the instrument and the absorption of the sample at this wavelength. Effects of the stray light on the shape of the spectrum and the extinction coefficients are shown. Methods for determining the existence and extent of stray light are suggested and are especially relevant for studies using pulse radiolysis, flash photolysis, and stopped-flow techniques. The literature examples for artifacts due to stray light are presented for kinetics and absorption spectra

Monitoring millimeter wave stray radiation during ECRH operation at ASDEX Upgrade

Science.gov (United States)

Schubert, M.; Honecker, F.; Monaco, F.; Schmid-Lorch, D.; Schütz, H.; Stober, J.; Wagner, D.

2012-09-01

Due to imperfection of the single path absorption, ECRH at ASDEX Upgrade (AUG) is always accompanied by stray radiation in the vacuum vessel. New ECRH scenarios with O2 and X3 heating schemes extend the operational space, but they have also the potential to increase the level of stray radiation. There are hazards for invessel components. Damage on electric cables has already been encountered. It is therefore necessary to monitor and control the ECRH with respect to the stray radiation level. At AUG a system of Sniffer antennas equipped with microwave detection diodes is installed. The system is part of the ECRH interlock circuit. We notice, however, that during plasma operation the variations of the Sniffer antenna signal are very large. In laboratory measurements we see variations of up to 20 dB in the directional sensitivity and we conclude that an interference pattern is formed inside the copper sphere of the antenna. When ECRH is in plasma operation at AUG, the plasma is acting as a phase and mode mixer for the millimeter waves and thus the interference pattern inside the sphere changes with the characteristic time of the plasma dynamics. In order to overcome the difficulty of a calibrated measurement of the average stray radiation level, we installed bolometer and pyroelectric detectors, which intrinsically average over interference structures due to their large active area. The bolometer provides a robust calibration but with moderate temporal resolution. The pyroelectric detector provides high sensitivity and a good temporal resolution, but it raises issues of possible signal drifts in long pulses.

Monitoring millimeter wave stray radiation during ECRH operation at ASDEX Upgrade

Directory of Open Access Journals (Sweden)

Wagner D.

2012-09-01

Full Text Available Due to imperfection of the single path absorption, ECRH at ASDEX Upgrade (AUG is always accompanied by stray radiation in the vacuum vessel. New ECRH scenarios with O2 and X3 heating schemes extend the operational space, but they have also the potential to increase the level of stray radiation. There are hazards for invessel components. Damage on electric cables has already been encountered. It is therefore necessary to monitor and control the ECRH with respect to the stray radiation level. At AUG a system of Sniffer antennas equipped with microwave detection diodes is installed. The system is part of the ECRH interlock circuit. We notice, however, that during plasma operation the variations of the Sniffer antenna signal are very large. In laboratory measurements we see variations of up to 20 dB in the directional sensitivity and we conclude that an interference pattern is formed inside the copper sphere of the antenna. When ECRH is in plasma operation at AUG, the plasma is acting as a phase and mode mixer for the millimeter waves and thus the interference pattern inside the sphere changes with the characteristic time of the plasma dynamics. In order to overcome the difficulty of a calibrated measurement of the average stray radiation level, we installed bolometer and pyroelectric detectors, which intrinsically average over interference structures due to their large active area. The bolometer provides a robust calibration but with moderate temporal resolution. The pyroelectric detector provides high sensitivity and a good temporal resolution, but it raises issues of possible signal drifts in long pulses.

Simplified magnetic circuit for the calculation of the stray magnetic flux through the shell gaps

Energy Technology Data Exchange (ETDEWEB)

Collarin, P.; Piovan, R. [Associazioni EURATOM-ENEA-CNR-Univ. di Padova (Italy). Gruppo di Padova per Ricerche sulla Fusione

1995-12-31

Significant toroidal magnetic field perturbations, stray flux at the shell gaps and current mismatching in the coils of the toroidal field winding are measured during the start-up and the flat-top phases of RFX. These phenomena are consistent with large and wall locked MHD modes: at first some m = 1 modes evolve separately one after the other, afterwards they concur to a wide and localized plasma perturbation that persists during the flat-top. These perturbations are heavily influenced by the stray magnetic flux through the shell gaps. Hence a magnetic circuit that mainly considers the magnetic reluctance of the conducting shell gaps has been developed in order to estimate this stray flux and, therefore, to evaluate the stabilizing capability of the shell. The observation of the MHD modes, the description of the equivalent magnetic network, the estimation of the stray flux and the comparison with the experimental measurements are reported in the paper.

Simplified magnetic circuit for the calculation of the stray magnetic flux through the shell gaps

International Nuclear Information System (INIS)

Collarin, P.; Piovan, R.

1995-01-01

Significant toroidal magnetic field perturbations, stray flux at the shell gaps and current mismatching in the coils of the toroidal field winding are measured during the start-up and the flat-top phases of RFX. These phenomena are consistent with large and wall locked MHD modes: at first some m = 1 modes evolve separately one after the other, afterwards they concur to a wide and localized plasma perturbation that persists during the flat-top. These perturbations are heavily influenced by the stray magnetic flux through the shell gaps. Hence a magnetic circuit that mainly considers the magnetic reluctance of the conducting shell gaps has been developed in order to estimate this stray flux and, therefore, to evaluate the stabilizing capability of the shell. The observation of the MHD modes, the description of the equivalent magnetic network, the estimation of the stray flux and the comparison with the experimental measurements are reported in the paper

Seroprevalence of Ehrlichia canis infection in stray dogs from Serbia

Directory of Open Access Journals (Sweden)

Nataša Bogićević

2017-03-01

Full Text Available Canine Monocytic Ehrlichiosis is a zoonotic bacterial disease with worldwide distribution. With regards to the population of stray dogs, the disease is facilitated due to their lifestyle and the lack of anti-parasitic protection. The aim of this study was to provide serological data on the presence of a specific Ehrlichia canis IgG antibodies in stray dogs, originating from 7 municipalities in Serbia. During the period from April 2013 to June 2014, 217 canine sera were submitted to the laboratory of the Department of Infectious Diseases of Animals and Bees, Faculty of Veterinary Medicine in Belgrade. An immunofluorescent antibody test (IFAT was performed to detect antibodies to Ehrlichia canis (cut off, 1:50. Seropositive dogs were found in 5 out of 7 counties with a seroprevalence varying from 3.57% to 20% and an overall seroprevalence of 11.06% (24/217. There was no statistically significant difference between the prevalence of infection and the host age or gender. Results showed that stray dogs contribute to maintaining and spreading of Ehrlichia canis in Serbia. Due to the close relationship between people and dogs, it is of great importance to constantly monitor and improve prevention of this disease.

PCR-Based Molecular Characterization of Toxocara spp. Using Feces of Stray Cats: A Study from Southwest Iran

OpenAIRE

Khademvatan, Shahram; Rahim, Fakher; Tavalla, Mahdi; Abdizadeh, Rahman; Hashemitabar, Mahmoud

2013-01-01

Feces of stray cat are potential sources of gastrointestinal parasites and play a crucial role in spreading and transmitting parasite eggs, larvae, and oocysts through contamination of soil, food, or water. In this study, we investigated the prevalence of Toxocara spp. infection in stray cats in Ahvaz city, southwest Iran. Eggs of Toxocara spp. in feces of stray cats were detected by the sucrose flotation method, and identification was conducted by polymerase chain reaction (PCR) and DNA sequ...

Convergence of highly parallel stray field calculation using the fast multipole method on irregular meshes

Science.gov (United States)

Palmesi, P.; Abert, C.; Bruckner, F.; Suess, D.

2018-05-01

Fast stray field calculation is commonly considered of great importance for micromagnetic simulations, since it is the most time consuming part of the simulation. The Fast Multipole Method (FMM) has displayed linear O(N) parallelization behavior on many cores. This article investigates the error of a recent FMM approach approximating sources using linear—instead of constant—finite elements in the singular integral for calculating the stray field and the corresponding potential. After measuring performance in an earlier manuscript, this manuscript investigates the convergence of the relative L2 error for several FMM simulation parameters. Various scenarios either calculating the stray field directly or via potential are discussed.

Implementasi Analog Front End Pada Sensor Kapasitif Untuk Pengaturan Kelembaban Menggunakan Mikrokontroller STM32

Directory of Open Access Journals (Sweden)

Rendy Setiawan

2017-01-01

Full Text Available Sensor kapasitif merupakan jenis sensor yang mengubah stimulus fisik menjadi perubahan kapasitansi. Pada sensor kapasitif, adanya stray capacitance atau kapasitansi parasitik pada sensor dapat menyebabkan kesalahan dalam pengukuran. Dalam aplikasi pengaturan kelembaban, dibutuhkan sistem pengukuran kelembaban dengan kesalahan minimum untuk mendapatkan nilai setting point dengan galat minimum. Maka diperlukan implementasi analog front end yang dapat meminimalisir kesalahan akibat stray capacitance pada sensor kapasitif untuk pengukuran kelembaban relatif. Pada sistem pengukuran sensor kapasitif ini, sensor dieksitasi dengan sinyal AC yang dihasilkan oleh generator sinyal pada frekuensi 10 KHz, kemudian diimplementasikan analog front end untuk mengondisikan sinyal dari sensor. Keluaran dari analog front end dikonversi menjadi sinyal DC menggunakan demodulator sinkron dan filter low pass lalu dikonversi menjadi data digital menggunakan ADC di mikrokontroller STM32. Hasil pengukuran yang didapatkan dengan implementasi analog front end kemudian kemudian gunakan untuk mengatur kelembaban pada sebuah plant growth chamber. Berdasarkan hasil dari pengujian, rangkaian analog front end dapat mengompensasi stray capacitance dengan kesalahan pembacaan nilai kapasitansi maksimal sebesar 4.2% pada kondisi stray capacitance sebesar 236,6pF, 174,3pF dan 115,7pF. Implementasi analog front end pada pengaturan kelembaban menghasilkan galat pada setting point maksimal sebesar 8.8% untuk nilai RH 75% dan 33%.

Accurate Measurement of ‘Q’ Factor of An Inductive Coil Using a Modified Maxwell Wein Bridge Network

Directory of Open Access Journals (Sweden)

Subrata CHATTOPADHYAY

2009-06-01

Full Text Available The Q factor of a coil can be measured by measuring accurately the inductance and effective resistance of the coil for a specific signal. The inductance of an inductive coil is generally measured by usual inductive circuit like Maxwell-Wein Bridge, Hay Bridge etc. which suffer from error due to stray capacitance between bridge nodal point and ground and stray inductance of the inductive coil. The conventional Wagner Earth Technique is not suitable for continuous measurement. In the present paper, a modified operational amplifier based Maxwell-Wein Bridge measurement technique has been proposed in which stray capacitance and stray inductance are minimized. The experiment is done for different value of known inductance & Q factor for a specific signal. The linear characteristic with a good repeatability, linearity and variable sensitivity has been described.

A study on protozoan infections (Giardia, Entamoeba, Isoapora and Cryptosporidium in stray dogs in Ilam province

Directory of Open Access Journals (Sweden)

S Kakekhani

2011-11-01

Full Text Available Giardia, Entamoeba, Isospora and Cryptosporidium are important protozoan parastites that caused diarrhea in human and animals. In the present study, fecal samples were collected fresh, directly from the rectum of 112 stray dogs in Ilam province. Giardia and Entamoeba were concentrated by using the formalin ether sedimentation method followed by the trichrome and iodine staining technique andCryptosporidium  oocysts  were  concentrated  by  using  the  formalin  ether  sedimentation  method  followed by the modified Ziehl-Neelsen staining technique. Of 112 stray dogs, protozoan infections were detected from feces of 46 dogs (41.07% that Giardia infection was detected from feces of 21 dogs (18.75%, Isospora 17 (15.17%, Cryptosporidium 8 (7.14% and synchronization infection to 2 protozoan in 9 dogs (8.03% and to 3 protozoan in 3 (2.67%. In the present study not observed to Entamoeba. No statistically significant differences in prevalence of protozoan parasites occurred between female (34.21 % and male (55.5 % stray dogs (p>0/05. But statistically significant differences in prevalence occurred between 1≥0 and 0 ≥1 stray dogs (p>0/05. So that stray dogs of Ilam province can cause infection of human water and food sources.

False capacitance of supercapacitors

OpenAIRE

Ragoisha, G. A.; Aniskevich, Y. M.

2016-01-01

Capacitance measurements from cyclic voltammetry, galvanostatic chronopotentiometry and calculation of capacitance from imaginary part of impedance are widely used in investigations of supercapacitors. The methods assume the supercapacitor is a capacitor, while real objects correspond to different equivalent electric circuits and show various contributions of non-capacitive currents to the current which is used for calculation of capacitance. Specific capacitances which are presented in F g-1...

Internal stray radiation measurement for cryogenic infrared imaging systems using a spherical mirror.

Science.gov (United States)

Tian, Qijie; Chang, Songtao; He, Fengyun; Li, Zhou; Qiao, Yanfeng

2017-06-10

Internal stray radiation is a key factor that influences infrared imaging systems, and its suppression level is an important criterion to evaluate system performance, especially for cryogenic infrared imaging systems, which are highly sensitive to thermal sources. In order to achieve accurate measurement for internal stray radiation, an approach is proposed, which is based on radiometric calibration using a spherical mirror. First of all, the theory of spherical mirror design is introduced. Then, the calibration formula considering the integration time is presented. Following this, the details regarding the measurement method are presented. By placing a spherical mirror in front of the infrared detector, the influence of internal factors of the detector on system output can be obtained. According to the calibration results of the infrared imaging system, the output caused by internal stray radiation can be acquired. Finally, several experiments are performed in a chamber with controllable inside temperatures to validate the theory proposed in this paper. Experimental results show that the measurement results are in good accordance with the theoretical analysis, and demonstrate that the proposed theories are valid and can be employed in practical applications. The proposed method can achieve accurate measurement for internal stray radiation at arbitrary integration time and ambient temperatures. The measurement result can be used to evaluate whether the suppression level meets the system requirement.

Detection of Hepatozoon canis in stray dogs and cats in Bangkok, Thailand.

Science.gov (United States)

Jittapalapong, Sathaporn; Rungphisutthipongse, Opart; Maruyama, Soichi; Schaefer, John J; Stich, Roger W

2006-10-01

A rapidly increasing stray animal population in Bangkok has caused concern regarding transmission of vector-borne and zoonotic diseases. The purpose of this study was to determine if stray animals in Bangkok are a potential reservoir of Hepatozoon, a genus of tick-borne parasites that has received little attention in Thailand. Blood samples were collected from stray companion animals near monasteries in 42 Bangkok metropolitan districts. Both dogs and cats were sampled from 26 districts, dogs alone from 4 districts and cats alone from 12 districts. Samples were collected from a total of 308 dogs and 300 cats. Light microscopy and an 18 S rRNA gene-based PCR assay were used to test these samples for evidence of Hepatozoon infection. Gamonts were observed in blood smears for 2.6% of dogs and 0.7% of cats by microscopy. The PCR assay detected Hepatozoon in buffy coats from 11.4% of dogs and 32.3% of cats tested. The prevalence of infection was the same between male and female dogs or cats, and PCR-positive dogs and cats were found in 36.6% and 36.8% of the districts surveyed, respectively. There was an association between the percentages of PCR-positive dogs and cats in districts where both host species were sampled. Sequences of representative amplicons were closest to those reported for H. canis. These results represent the first molecular confirmation that H. canis is indigenous to Thailand. The unexpectedly high prevalence of Hepatozoon among stray cats indicates that their role in the epizootiology of hepatozoonosis should be investigated.

A new interface weak-capacitance detection ASIC of capacitive liquid level sensor in the rocket

Science.gov (United States)

Yin, Liang; Qin, Yao; Liu, Xiao-Wei

2017-11-01

A new capacitive liquid level sensing interface weak-capacitance detection ASIC has been designed. This ASIC realized the detection of the output capacitance of the capacitive liquid level sensor, which converts the output capacitance of the capacitive liquid level sensor to voltage. The chip is fabricated in a standard 0.5μm CMOS process. The test results show that the linearity of capacitance detection of the ASIC is 0.05%, output noise is 3.7aF/Hz (when the capacitance which will be detected is 40 pF), the stability of capacitance detection is 7.4 × 10-5pF (1σ, 1h), the output zero position temperature coefficient is 4.5 uV/∘C. The test results prove that this interface ASIC can meet the requirement of high accuracy capacitance detection. Therefore, this interface ASIC can be applied in capacitive liquid level sensing and capacitive humidity sensing field.

It’s a Dog’s Life: International Tourists’ Perceptions of the Stray Dog Population of Bhutan.

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Paul C Strickland

2015-12-01

Full Text Available This study investigates the international tourists’ perception of the stray dog population of Bhutan as little or no mention of the increasing stray dog population and their impact on tourism has been documented. After personally visiting the Kingdom on many occasions, it is evident that the stray dog population is increasing in dog numbers in major cities. The problems arising are negative comments by tourists relating to the stray dog population that are starting to appear in social media that may impact the visitor experience and the perception of Bhutan’s tourism industry. Veterinary science is aware of both increasing dog populations and the control of diseases such as Rabies however the author can find no evidence regarding challenges for the tourism industry. The problem is aided by no local veterinary clinics, no laws regarding dog governance, little funding for sterilization programs and being predominately a Buddhist country that cannot ‘cull’ animals. Using qualitative analysis from international tourist focus groups who were visiting Bhutan, this study highlights the perceptions of tourists regarding the stray dog population and how it may impact on visitor expectations. The paper suggests options that local government, Bhutanese nationals and visitors can do to assist the issue based on visitor feedback. Future research may include comparisons with other cities or countries to examine if it is a global issue or unique to Bhutan.

Identification of Zoonotic Parasites isolated from Stray Dogs in Bojnurd County Located in North-East of Iran

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Kourosh Arzamani

2016-10-01

Full Text Available Dog can represent as an important source of zoonotic disease and important health problem for human. They can carry dangerous parasitic diseases such as hydatidosis, toxocariasis and Coenurus cerebralis to humans and animals. This study was performed in order to determine the prevalence and intensity of zoonotic parasites among stray dogs from Bojnurd, the capital city of North Khorasan province in North West of Iran. During a program performing by Bojnurd municipal on the slow killing of stray dogs, 32 dogs from Jun 2013 till March 2015 were selected. At necropsy their alimentary canals were removed and to identify the species of helminthes, the nematodes were cleared in lactophenol and cestodes were stained using carmine acid. Intestinal protozoan parasites were detected with parasitological methods. 28 (87.5% of 32 stray dogs infected at least with one helminth. Seven species of cestodes were isolated from examined dogs and three species of nematode were detected. Giardia sp. and Cryptosporidium sp. detected from fecal samples. This is the first study of the prevalence of intestinal zoonotic parasites in dogs in this area. It seems control of bearing stray dogs can help human health and reduction economic losses caused by stray dog’s zoonotic parasites.

Carbon Nanotubes on Titanium Substrates for Stray Light Suppression

Science.gov (United States)

Hagopian, John; Getty, Stephanie; Quijada, Manuel

2011-01-01

A method has been developed for growing carbon nanotubes on a titanium substrate, which makes the nano tubes ten times blacker than the current state-of-the-art paints in the visible to near infrared. This will allow for significant improvement of stray light performance in scientific instruments, or any other optical system. Because baffles, stops, and tubes used in scientific observations often undergo loads such as vibration, it is critical to develop this surface treatment on structural materials. This innovation optimizes the carbon nano - tube growth for titanium, which is a strong, lightweight structural material suitable for spaceflight use. The steps required to grow the nanotubes require the preparation of the surface by lapping, and the deposition of an iron catalyst over an alumina stiction layer by e-beam evaporation. In operation, the stray light controls are fabricated, and nanotubes (multi-walled 100 microns in length) are grown on the surface. They are then installed in the instruments or other optical devices.

Bartonella and Toxoplasma Infections in Stray Cats from Iraq

Science.gov (United States)

Switzer, Alexandra D.; McMillan-Cole, Audrey C.; Kasten, Rickie W.; Stuckey, Matthew J.; Kass, Philip H.; Chomel, Bruno B.

2013-01-01

Because of overpopulation, stray/feral cats were captured on military bases in Iraq as part of the US Army Zoonotic Disease Surveillance Program. Blood samples were collected from 207 cats, mainly in Baghdad but also in North and West Iraq, to determine the prevalence of Bartonella and Toxoplasma infections. Nine (4.3%) cats, all from Baghdad, were bacteremic with B. henselae type I. Seroprevalence was 30.4% for T. gondii, 15% for B. henselae, and 12.6% for B. clarridgeiae. Differences in Bartonella prevalence by location were statistically significant, because most of the seropositive cats were from Baghdad. There was no association between T. gondii seropositivity and either of the two Bartonella species surveyed. This report is the first report on the prevalence of Bartonella and T. gondii among stray cats in Iraq, which allows for better evaluation of the zoonotic risk potential to the Iraqi people and deployed military personnel by feral cat colonies. PMID:24062480

Problems Associated with the Microchip Data of Stray Dogs and Cats Entering RSPCA Queensland Shelters

Science.gov (United States)

Lancaster, Emily; Rand, Jacquie; Collecott, Sheila; Paterson, Mandy

2015-01-01

Simple Summary Microchip identification has become an important tool to reunite stray dogs and cats with their owners, and is now compulsory in most states of Australia. Improvement of the microchipping system in Australia is limited by a lack of published Australian data documenting the problems experienced by shelter staff when using microchip data to contact the owner of a stray animal. In this study we determine the character and frequency of inaccurate microchip data to identify weaknesses in the current microchipping system. This information could be used to develop strategies that increase the accuracy of microchip data that will increase the reclaiming of stray animals. Abstract A lack of published information documenting problems with the microchip data for the reclaiming of stray animals entering Australian shelters limits improvement of the current microchipping system. A retrospective study analysing admission data for stray, adult dogs (n = 7258) and cats (n = 6950) entering the Royal Society for the Prevention of Cruelty to Animals (RSPCA) Queensland between January 2012 and December 2013 was undertaken to determine the character and frequency of microchip data problems and their impact on outcome for the animal. Only 28% of dogs and 9% of cats were microchipped, and a substantial proportion (37%) had problems with their data, including being registered to a previous owner or organisation (47%), all phone numbers incorrect/disconnected (29%), and the microchip not registered (14%). A higher proportion of owners could be contacted when the microchip had no problems, compared to those with problems (dogs, 93% vs. 70%; cats, 75% vs. 41%). The proportion of animals reclaimed declined significantly between microchipped animals with no data problems, microchipped animals with data problems and non-microchipped animals—87%, 69%, and 37%, respectively, for dogs and 61%, 33%, and 5%, respectively, for cats. Strategies are needed to increase the accuracy of

Feline immunodeficiency virus testing in stray, feral, and client-owned cats of Ottawa

OpenAIRE

Little, Susan E.

2005-01-01

Feline immunodeficiency virus (FIV) seroprevalence is evaluated in 3 groups of cats. Seventy-four unowned urban strays were tested, as well as 20 cats from a small feral cat colony, and 152 client-owned cats. Of the 246 cats tested, 161 (65%) were male and 85 (35%) were female. Seroprevalence for FIV was 23% in the urban strays, 5% in the feral cat colony, and 5.9% in the client-owned cats. Ten cats (4%) were also positive for Feline leukemia virus (FeLV) antigen, including 2 cats coinfected ...

Stray current vs anodic polarization in reinforced mortar: a comparative study on steel corrosion behaviour in both regimes

NARCIS (Netherlands)

Chen, Zhipei; Koleva, D.A.; van Breugel, K.

2015-01-01

Stray current arising from direct current electrified traction systems and then circulat-ing in reinforced concrete structures may initiate corrosion or even accelerate existing corrosion processes on embedded reinforcement. Therefore, stray-current induced corrosion of nearby reinforced concrete

Residual stress characterization of steel TIG welds by neutron diffraction and by residual magnetic stray field mappings

Energy Technology Data Exchange (ETDEWEB)

Stegemann, Robert, E-mail: Robert.Stegemann@bam.de [Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, 12200 Berlin (Germany); Cabeza, Sandra; Lyamkin, Viktor; Bruno, Giovanni; Pittner, Andreas [Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, 12200 Berlin (Germany); Wimpory, Robert; Boin, Mirko [HZB Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Kreutzbruck, Marc [Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, 12200 Berlin (Germany); IKT, University of Stuttgart, Pfaffenwaldring 32, 70569 Stuttgart (Germany)

2017-03-15

The residual stress distribution of tungsten inert gas welded S235JRC+C plates was determined by means of neutron diffraction (ND). Large longitudinal residual stresses with maxima around 600 MPa were found. With these results as reference, the evaluation of residual stress with high spatial resolution GMR (giant magneto resistance) sensors was discussed. The experiments performed indicate a correlation between changes in residual stresses (ND) and the normal component of local residual magnetic stray fields (GMR). Spatial variations in the magnetic field strength perpendicular to the welds are in the order of the magnetic field of the earth. - Highlights: • Comparison of magnetic microstructure with neutron diffraction stress analysis. • High spatial resolution magnetic stray field images of hypereutectoid TIG welds. • Spatial variations of the stray fields are below the magnetic field of the earth. • GMR spin valve gradiometer arrays adapted for the evaluation of magnetic microstructures. • Magnetic stray fields are closely linked to microstructure of the material.

Stray light correction on array spectroradiometers for optical radiation risk assessment in the workplace

International Nuclear Information System (INIS)

Barlier-Salsi, A

2014-01-01

The European directive 2006/25/EC requires the employer to assess and, if necessary, measure the levels of exposure to optical radiation in the workplace. Array spectroradiometers can measure optical radiation from various types of sources; however poor stray light rejection affects their accuracy. A stray light correction matrix, using a tunable laser, was developed at the National Institute of Standards and Technology (NIST). As tunable lasers are very expensive, the purpose of this study was to implement this method using only nine low power lasers; other elements of the correction matrix being completed by interpolation and extrapolation. The correction efficiency was evaluated by comparing CCD spectroradiometers with and without correction and a scanning double monochromator device as reference. Similar to findings recorded by NIST, these experiments show that it is possible to reduce the spectral stray light by one or two orders of magnitude. In terms of workplace risk assessment, this spectral stray light correction method helps determine exposure levels, with an acceptable degree of uncertainty, for the majority of workplace situations. The level of uncertainty depends upon the model of spectroradiometers used; the best results are obtained with CCD detectors having an enhanced spectral sensitivity in the UV range. Thus corrected spectroradiometers require a validation against a scanning double monochromator spectroradiometer before using them for risk assessment in the workplace. (paper)

Stray light correction on array spectroradiometers for optical radiation risk assessment in the workplace.

Science.gov (United States)

Barlier-Salsi, A

2014-12-01

The European directive 2006/25/EC requires the employer to assess and, if necessary, measure the levels of exposure to optical radiation in the workplace. Array spectroradiometers can measure optical radiation from various types of sources; however poor stray light rejection affects their accuracy. A stray light correction matrix, using a tunable laser, was developed at the National Institute of Standards and Technology (NIST). As tunable lasers are very expensive, the purpose of this study was to implement this method using only nine low power lasers; other elements of the correction matrix being completed by interpolation and extrapolation. The correction efficiency was evaluated by comparing CCD spectroradiometers with and without correction and a scanning double monochromator device as reference. Similar to findings recorded by NIST, these experiments show that it is possible to reduce the spectral stray light by one or two orders of magnitude. In terms of workplace risk assessment, this spectral stray light correction method helps determine exposure levels, with an acceptable degree of uncertainty, for the majority of workplace situations. The level of uncertainty depends upon the model of spectroradiometers used; the best results are obtained with CCD detectors having an enhanced spectral sensitivity in the UV range. Thus corrected spectroradiometers require a validation against a scanning double monochromator spectroradiometer before using them for risk assessment in the workplace.

Theoretical study of the Cs isotope exchange reaction of CsI + Cs' → Cs + ICs' (Contract research)

International Nuclear Information System (INIS)

Kobayashi, Takanori; Hashimoto, Masashi; Yokoyama, Keiichi

2015-12-01

To discuss the exchange reaction of Cs isotope by CsI + Cs' → Cs + ICs', the structure and chemical properties of Cs 2 I intermediate and potential energy surface of the entrance reaction are calculated using M06/def2-TZVPPD density functional calculation. The calculation shows that the reaction to the intermediate has no barrier and the two Cs-I bonds of Cs 2 I are chemically equivalent. These results suggest that the rate of the Cs exchange reaction of CsI + Cs' → Cs + ICs' is as high as the collision rate. (author)

Study of Intestinal Helminthes of Stray Dogs and Thir Public Heath Importance in Hamadan City

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Kh. Rahmati

2016-11-01

Full Text Available Introduction: Intestinal helminthesof dogs are a serious threat to human health and may cause dangerous diseases such as: hydatidosis and visceral larva migrans, that which cause severe complications in human. Th aim of this study was to determine the prevalenceof intestinal helminthes of stray dogs in Hamadan city, Iran.. Methods: A total of 103 stray dogswere shot in the inner and around of the city in year 2015. Following necropsy, the intestines' contents of dogs were examined for helminthes macroscopically. Thn, the collected worms, aftr washing with saline,were counted and identifid according to being Nematode, Cestodeor Acantcephala. Thn, collected Nematodes were put in glass containers containing 70% ethanol-glycerine and Cestodes aftr processing on slides were put in the 10% formalin. To identify the species of helminthes, the Cestodes were stained using carmine acid and Nematodes were cleared in lacto-phenol. Results: Result indicated that, 74(71.8%stray dogs were infected at least by one species of intestinal helminthes. Th species of parasites were as follows: Echinococcus granulosus 37.9%, Dipylidium caninum 51.5%, Toxocara canis 19.4%, Taenia hydatigena 24.3%, T. multiceps 2.9%, T. ovis 1.9%, Mesocest oideslineatus 4.9%, and Acantho cephala 5.8%. Thre was no association between insex, season and region with prevalence of intestinal helminthes (P 0.05 between the prevalence of intestinal helminthes and dogs' age. Conclusions: Ths study indicatesd that,infection rate of helminthes in stray dogs is washigh in Hamadan city. Thse parasites are important in terms of human health and economic aspects. Threfore, it is more essential that public health authoritiesto develop control strategies for stray dogs population.

Gastrointestinal parasites in stray and shelter cats in the municipality of Rio de Janeiro, Brazil

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Pâmela Figueiredo Pereira

Full Text Available Abstract The increasingly urban nature of the population has led many people to choose independent pets, such as cats. This situation has also made it possible for these animals to be abandoned, thus increasing the numbers of cats on the streets and in shelters. These animals can act as a source of infection for other hosts. Between 2014 and 2015, the frequency of gastrointestinal parasites in captive and stray cats in the municipality of Rio de Janeiro was analyzed. Ninety-one fecal samples were collected from captive cats and 172 from stray cats. Centrifugal sedimentation and flotation techniques were used. The frequency of parasites among the stray cats was 77.3%, and this was significantly higher than the frequency observed in captive cats (49.5%. Helminths were detected more frequently, and hookworms were the parasites most detected. Toxocara cati, Cystoisospora sp. and Dipylidium caninum were also detected. No statistical difference in the frequency of parasites was observed between the sexes among the captive cats. However, among the stray cats, males (85.5% presented higher positivity than females (71.8%. The high frequency of hookworms, which are the agent for “cutaneous larva migrans” in humans, shows the need to control parasitic infections among the cats studied.

PCR-based molecular characterization of Toxocara spp. using feces of stray cats: a study from Southwest Iran.

Science.gov (United States)

Khademvatan, Shahram; Rahim, Fakher; Tavalla, Mahdi; Abdizadeh, Rahman; Hashemitabar, Mahmoud

2013-01-01

Feces of stray cat are potential sources of gastrointestinal parasites and play a crucial role in spreading and transmitting parasite eggs, larvae, and oocysts through contamination of soil, food, or water. In this study, we investigated the prevalence of Toxocara spp. infection in stray cats in Ahvaz city, southwest Iran. Eggs of Toxocara spp. in feces of stray cats were detected by the sucrose flotation method, and identification was conducted by polymerase chain reaction (PCR) and DNA sequencing. Of the 140 fecal samples that were randomly collected from public environments during the months of January to May 2012, 45% were found to harbour Toxocara spp. eggs. The highest prevalence of Toxocara spp. eggs was found in the central area of Ahvaz city (28.6%). T. canis eggs were found in 4 (6.34%) of the 63 positive samples. Stray cats are found in parks, playgrounds, and other public places and may be a potential contamination risk. Identification of Toxocara spp. using molecular methods is sufficiently sensitive to detect low levels of parasites and identify the different Toxocara spp. in feces. The relatively high prevalence of Toxocara spp. infection may continue to increase due to lack of effective environmental hygiene control in Iran. Consequently, there is a need to plan adequate programs to detect, identify, and control this infection as well as stray cats in the region.

PCR-based molecular characterization of Toxocara spp. using feces of stray cats: a study from Southwest Iran.

Directory of Open Access Journals (Sweden)

Shahram Khademvatan

Full Text Available Feces of stray cat are potential sources of gastrointestinal parasites and play a crucial role in spreading and transmitting parasite eggs, larvae, and oocysts through contamination of soil, food, or water. In this study, we investigated the prevalence of Toxocara spp. infection in stray cats in Ahvaz city, southwest Iran. Eggs of Toxocara spp. in feces of stray cats were detected by the sucrose flotation method, and identification was conducted by polymerase chain reaction (PCR and DNA sequencing. Of the 140 fecal samples that were randomly collected from public environments during the months of January to May 2012, 45% were found to harbour Toxocara spp. eggs. The highest prevalence of Toxocara spp. eggs was found in the central area of Ahvaz city (28.6%. T. canis eggs were found in 4 (6.34% of the 63 positive samples. Stray cats are found in parks, playgrounds, and other public places and may be a potential contamination risk. Identification of Toxocara spp. using molecular methods is sufficiently sensitive to detect low levels of parasites and identify the different Toxocara spp. in feces. The relatively high prevalence of Toxocara spp. infection may continue to increase due to lack of effective environmental hygiene control in Iran. Consequently, there is a need to plan adequate programs to detect, identify, and control this infection as well as stray cats in the region.

A review on stray current-induced steel corrosion in infrastructure

NARCIS (Netherlands)

Chen, Zhipei; Koleva, D.A.; van Breugel, K.

2017-01-01

Metallic corrosion can cause substantial damage at various levels and in almost all types of infrastructure. For metallic corrosion to occur, a certain external environment and the presence of corrodents are the prerequisites. Stray current-induced corrosion, however, is a rather underestimated

Experimental Study on the Influence of AC Stray Current on the Cathodic Protection of Buried Pipe

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Qingmiao Ding

2016-01-01

Full Text Available The size of the damaged area of the coating and its position on the pipeline impacted the cathodic protection potential, and there was a damaged area of the greatest impact value. When damaged area was 300 mm2, the IR drop was the largest, and this situation could easily lead to inadequate protection; when the parallel spacing between pipeline and interference source was unchanged, the measured value curves of cathodic protection potential presented “U” shaped trend with the increasing stray current interference intensity. Under certain parallel spacing between pipeline and interference source, high alternating stray current intensity would cause serious negative offsets, so that the overprotection of the pipeline occurred, and make the coating crack; there was a parallel threshold length. When less than the threshold, the pipe-ground potential increases rapidly with the parallel length increasing. In order to judge whether a pipeline was interference by AC stray current and the risk of stray current corrosion, we should make a comprehensive analysis of the cathodic protection energizing potential, the switch-off potential, AC pipe-soil potential, IR drops, and so on.

What's in a name? Perceptions of stray and feral cat welfare and control in Aotearoa, New Zealand.

Science.gov (United States)

Farnworth, Mark J; Campbell, Joanna; Adams, Nigel J

2011-01-01

New Zealanders (n = 354) rated the acceptability of lethal and nonlethal cat control methods and the importance of conservation and welfare. Lethal control was more acceptable for feral cats than strays; for nonlethal control, the inverse was true. More than concern for the welfare of cats subjected to control, perceived conservation benefits, risk of disease transfer, and companion cat welfare dictated the acceptability of control measures. Similarly, the welfare consideration for groups of cats differed, transitioning from companion (highest) to feral (lowest). Differences in attitudes toward acceptability of control methods were evident. In particular, nonhuman animal professionals ranked lethal control as more acceptable than did nonanimal professionals. Cat caregivers (owners) considered both conservation and welfare issues of greater importance than did nonowners. Owners ranked the acceptability of nonlethal control methods higher for stray cats, but not feral, than did nonowners. This research indicates that the use of the terms stray and feral may have significant impact on cats in New Zealand. There is also a greater consideration of conservation values than of welfare in stray and feral cat control.

Molecular detection of blood pathogens and their impacts on levels of packed cell volume in stray dogs from Thailand

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Supawadee Piratae

2017-04-01

Full Text Available Objective: To evaluate the prevalence of blood parasite infection in stray dogs by PCR technique and the association between levels of packed cell volume (PCV and blood parasitic infection in stray dogs. Methods: A total of 65 blood samples were collected from stray dogs in animal quarantine station from Mahasarakham, Thailand to evaluate the levels of PCV before molecular screening for tick-borne pathogens infection. Results: Stray dogs were positive with one or more pathogens in 44 (67.69% out of 65 blood samples. Ehrlichia canis [43.1%, 95% confidence interval (CI: 38.1–48.1] was the most common blood pathogen found infecting in stray dogs in Mahasarakham Province, followed by Anaplasma platys (29.2%, 95% CI: 24.2–34.2, Hepatozoon canis (12.3%, 95% CI: 7.3–17.3 and Babesia canis vogeli (6.2%, 95% CI: 1.2–11.2, respectively. Moreover, co-infections with two pathogens were identified in 11 (16.9% of dogs examined and two (2.9% dogs were coinfections with three pathogens. Statistically significant relationship between the PCV levels and Ehrlichia canis infection was found (P < 0.05. Conclusions: This study indicated that blood pathogens are spreading in stray dogs and they are potentially high risk of agent transmission to human via exposure with tick vectors. It was also the first report of Anaplasma platys infection in dogs in north-eastern part of Thailand.

Detection of Helminth Eggs and Identification of Hookworm Species in Stray Cats, Dogs and Soil from Klang Valley, Malaysia.

Science.gov (United States)

Tun, Sandee; Ithoi, Init; Mahmud, Rohela; Samsudin, Nur Izyan; Kek Heng, Chua; Ling, Lau Yee

2015-01-01

The present study was conducted to determine the prevalence of helminth eggs excreted in the faeces of stray cats, dogs and in soil samples. A total of 505 fresh samples of faeces (from 227 dogs and 152 cats) and soil were collected. The egg stage was detected via microscopy after the application of formalin-ether concentration technique. Genomic DNA was extracted from the samples containing hookworm eggs and used for further identification to the species level using real-time polymerase chain reaction coupled with high resolution melting analysis. Microscopic observation showed that the overall prevalence of helminth eggs among stray cats and dogs was 75.7% (95% CI = 71.2%-79.9%), in which 87.7% of dogs and 57.9% of cats were infected with at least one parasite genus. Five genera of heliminth eggs were detected in the faecal samples, including hookworms (46.4%), Toxocara (11.1%), Trichuris (8.4%), Spirometra (7.4%) and Ascaris (2.4%). The prevalence of helminth infections among stray dogs was significantly higher than that among stray cats (p dog hookworm, Ancylostoma caninum, was also detected among cats, which is the first such occurrence reported in Malaysia till date. This finding indicated that there was a cross-infection of A. caninum between stray cats and dogs because of their coexistent within human communities. Taken together, these data suggest the potential role of stray cats and dogs as being the main sources of environmental contamination as well as for human infections.

Counteracting Animal Homelessness and Providing Care for Stray Animals as a Task of a Commune

OpenAIRE

Szalewska, Małgorzata

2017-01-01

The analysis of Polish binding law acts allows one to assume that, on normative level, the obligation of public administration to provide care for stray animals is deeply embedded. Both the Animal Protection Act, as well as the Act on Maintaining Cleanliness, indicate the tasks of a commune in the scope of providing care for stray animals, catching homeless animals and counteracting their homelessness. Simultaneously, the analysis of jurisdiction, and inquiries as well as considerations emerg...

Stray dog meat consumption and rabies | Wiwanitkit | African Health ...

African Journals Online (AJOL)

Stray dog meat consumption and rabies. V Wiwanitkit. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/ahs.v14i3.41 · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians ...

Individual monitoring in high-energy stray radiation fields

International Nuclear Information System (INIS)

Hoefert, M.; Stevenson, G.R.

1995-01-01

Due to the lack of passive or active devices that could be considered as personal dosemeters in high-energy stray fields one can at present only perform individual monitoring around high energy accelerators. Of all detectors currently available it is shown that the NTA film is the most suitable method for individually monitoring the neutron exposure of more than 3000 persons regularly, reliably, and cost effectively like at CERN. (author)

Capacitive chemical sensor

Science.gov (United States)

Manginell, Ronald P; Moorman, Matthew W; Wheeler, David R

2014-05-27

A microfabricated capacitive chemical sensor can be used as an autonomous chemical sensor or as an analyte-sensitive chemical preconcentrator in a larger microanalytical system. The capacitive chemical sensor detects changes in sensing film dielectric properties, such as the dielectric constant, conductivity, or dimensionality. These changes result from the interaction of a target analyte with the sensing film. This capability provides a low-power, self-heating chemical sensor suitable for remote and unattended sensing applications. The capacitive chemical sensor also enables a smart, analyte-sensitive chemical preconcentrator. After sorption of the sample by the sensing film, the film can be rapidly heated to release the sample for further analysis. Therefore, the capacitive chemical sensor can optimize the sample collection time prior to release to enable the rapid and accurate analysis of analytes by a microanalytical system.

CS Informativeness Governs CS-US Associability

Science.gov (United States)

Ward, Ryan D.; Gallistel, C. R.; Jensen, Greg; Richards, Vanessa L.; Fairhurst, Stephen; Balsam, Peter D

2012-01-01

In a conditioning protocol, the onset of the conditioned stimulus (CS) provides information about when to expect reinforcement (the US). There are two sources of information from the CS in a delay conditioning paradigm in which the CS-US interval is fixed. The first depends on the informativeness, the degree to which CS onset reduces the average expected time to onset of the next US. The second depends only on how precisely a subject can represent a fixed-duration interval (the temporal Weber fraction). In three experiments with mice, we tested the differential impact of these two sources of information on rate of acquisition of conditioned responding (CS-US associability). In Experiment 1, we show that associability (the inverse of trials to acquisition) increases in proportion to informativeness. In Experiment 2, we show that fixing the duration of the US-US interval or the CS-US interval or both has no effect on associability. In Experiment 3, we equated the increase in information produced by varying the C̅/T̅ ratio with the increase produced by fixing the duration of the CS-US interval. Associability increased with increased informativeness, but, as in Experiment 2, fixing the CS-US duration had no effect on associability. These results are consistent with the view that CS-US associability depends on the increased rate of reward signaled by CS onset. The results also provide further evidence that conditioned responding is temporally controlled when it emerges. PMID:22468633

CONCENTRATION DEPENDENCE OF STERN LAYER CAPACITANCES AND SURFACE EQUILIBRIUM CONSTANTS IN SILICA-BASED NANOFLUIDIC CHANNELS

DEFF Research Database (Denmark)

Andersen, Mathias Bækbo; Frey, J.; Bruus, Henrik

2010-01-01

Fundamental understanding of the unique physics at the solid-liquid interface in nanofluidic channels is essential for the advancement of basic scientific knowledge and the development of novel applications for pharmaceuticals, environmental health and safety, energy harvesting and biometrics [1......]. The current models used to describe surface phenomena in nanofluidics can differ by orders of magnitude from experimentally measured values [2]. To mitigate the discrepancies, we hypothesize that the Stern-layer capacitance Cs and the surface equilibrium constants pKa, vary with the composition of the solid...

Controlling stray electric fields on an atom chip for experiments on Rydberg atoms

Science.gov (United States)

Davtyan, D.; Machluf, S.; Soudijn, M. L.; Naber, J. B.; van Druten, N. J.; van Linden van den Heuvell, H. B.; Spreeuw, R. J. C.

2018-02-01

Experiments handling Rydberg atoms near surfaces must necessarily deal with the high sensitivity of Rydberg atoms to (stray) electric fields that typically emanate from adsorbates on the surface. We demonstrate a method to modify and reduce the stray electric field by changing the adsorbate distribution. We use one of the Rydberg excitation lasers to locally affect the adsorbed dipole distribution. By adjusting the averaged exposure time we change the strength (with the minimal value less than 0.2 V /cm at 78 μ m from the chip) and even the sign of the perpendicular field component. This technique is a useful tool for experiments handling Rydberg atoms near surfaces, including atom chips.

Feline immunodeficiency virus testing in stray, feral, and client-owned cats of Ottawa.

Science.gov (United States)

Little, Susan E

2005-10-01

Feline immunodeficiency virus (FIV) seroprevalence is evaluated in 3 groups of cats. Seventy-four unowned urban strays were tested, as well as 20 cats from a small feral cat colony, and 152 client-owned cats. Of the 246 cats tested, 161 (65%) were male and 85 (35%) were female. Seroprevalence for FIV was 23% in the urban strays, 5% in the feral cat colony, and 5.9% in the client-owned cats. Ten cats (4%) were also positive for Feline leukemia virus (FeLV) antigen, including 2 cats coinfected with FeLV and FIV. Seroprevalence for FIV in cats from Ottawa is similar to that found in other nonrandom studies of cats in North America.

Measurement of stray EC radiation on W7-AS

Science.gov (United States)

Gandini, F.; Hirsch, M.; Cirant, S.; Erckmann, V.; Granucci, G.; Kasparek, W.; Laqua, H. P.; Muzzini, V.; Nowak, S.; Radau, S.

2001-10-01

In the framework of a collaboration between IFP-CNR Milano, IPP Garching/Greifswald and IPF Stuttgart, a set of four millimeterwave probes has been installed in W7-AS stellarator at selected positions of the inner vessel wall. Their purpose is to observe RF stray radiation during operation in presence of strong level of Electron Cyclotron (EC) waves, used for plasma start-up, heating and current drive. The aim of these measurements is to benchmark two complementary theoretical models for the distribution of the stray radiation in the vessel. From these codes, quantitative predictions are expected for the spatial distribution of the RF wall load and the RF-impact on in-vessel components in large future devices such as W7-X and, possibly, ITER. This input is important to optimize the wall armour and select rf-compatible in-vessel materials. We present first measurements from different heating and startup scenarios, with up to 800 kW of injected power at 140 GHz and different launching geometries. An analysis of measurements performed on FTU using a previous version of sniffer probe is also presented.

Measurement of stray EC radiation on W7-AS

International Nuclear Information System (INIS)

Gandini, F.; Cirant, S.; Granucci, G.; Muzzini, V.; Nowak, S.; Hirsch, M.; Erckmann, V.; Laqua, H.P.; Radau, S.; Kasparek, W.

2001-01-01

In the framework of a collaboration between IFP-CNR Milano, IPP Garching/Greifswald and IPF Stuttgart, a set of four millimeterwave probes has been installed in W7-AS stellarator at selected positions of the inner vessel wall. Their purpose is to observe RF stray radiation during operation in presence of strong level of Electron Cyclotron (EC) waves, used for plasma start-up, heating and current drive. The aim of these measurements is to benchmark two complementary theoretical models for the distribution of the stray radiation in the vessel. From these codes, quantitative predictions are expected for the spatial distribution of the RF wall load and the RF-impact on in-vessel components in large future devices such as W7-X and, possibly, ITER. This input is important to optimize the wall armour and select rf-compatible in-vessel materials. We present first measurements from different heating and startup scenarios, with up to 800 kW of injected power at 140 GHz and different launching geometries. An analysis of measurements performed on FTU using a previous version of sniffer probe is also presented

Prevalence of intestinal helminth parasites in stray dogs in urban ...

African Journals Online (AJOL)

A total of 246 faecal samples were collected between October 2015 to February 2016, 154 from stray dogs in Harare and 92 from rural dogs in Arcturas, Goromonzi and Christon Bank. The samples were examined by flotation and sedimentation methods and helminth eggs identified and EPG counted. Of the 246 samples, ...

MRI-related static magnetic stray fields and postural body sway: a double-blind randomized crossover study.

Science.gov (United States)

van Nierop, Lotte E; Slottje, Pauline; Kingma, Herman; Kromhout, Hans

2013-07-01

We assessed postural body sway performance after exposure to movement induced time-varying magnetic fields in the static magnetic stray field in front of a 7 Tesla (T) magnetic resonance imaging scanner. Using a double blind randomized crossover design, 30 healthy volunteers performed two balance tasks (i.e., standing with eyes closed and feet in parallel and then in tandem position) after standardized head movements in a sham, low exposure (on average 0.24 T static magnetic stray field and 0.49 T·s(-1) time-varying magnetic field) and high exposure condition (0.37 T and 0.70 T·s(-1)). Personal exposure to static magnetic stray fields and time-varying magnetic fields was measured with a personal dosimeter. Postural body sway was expressed in sway path, area, and velocity. Mixed-effects model regression analysis showed that postural body sway in the parallel task was negatively affected (P < 0.05) by exposure on all three measures. The tandem task revealed the same trend, but did not reach statistical significance. Further studies are needed to investigate the possibility of independent or synergetic effects of static magnetic stray field and time-varying magnetic field exposure. In addition, practical safety implications of these findings, e.g., for surgeons and others working near magnetic resonance imaging scanners need to be investigated. Copyright © 2012 Wiley Periodicals, Inc.

Molecular structures and thermodynamic properties of 12 gaseous cesium-containing species of nuclear safety interest: Cs 2, CsH, CsO, Cs 2O, CsX, and Cs 2X 2 (X = OH, Cl, Br, and I)

Science.gov (United States)

Badawi, Michael; Xerri, Bertrand; Canneaux, Sébastien; Cantrel, Laurent; Louis, Florent

2012-01-01

Ab initio electronic structure calculations at the coupled cluster level with a correction for the triples extrapolated to the complete basis set limit have been made for the estimation of the thermochemical properties of Cs 2, CsH, CsO, Cs 2O, CsX, and Cs 2X 2 (X = OH, Cl, Br, and I). The standard enthalpies of formation and standard molar entropies at 298 K, and the temperature dependence of the heat capacities at constant pressure were evaluated. The calculated thermochemical properties are in good agreement with their literature counterparts. For Cs 2, CsH, CsOH, Cs 2(OH) 2, CsCl, Cs 2Cl 2, CsBr, CsI, and Cs 2I 2, the calculated ΔfH298K∘ values are within chemical accuracy of the most recent experimental values. Based on the excellent agreement observed between our calculated ΔfH298K∘ values and their literature counterparts, the standard enthalpies of formation at 298 K are estimated to be the following: ΔfH298K∘ (CsO) = 17.0 kJ mol -1 and ΔfH298K∘ (Cs 2Br 2) = -575.4 kJ mol -1.

An approach to evaluate capacitance, capacitive reactance and resistance of pivoted pads of a thrust bearing

Science.gov (United States)

Prashad, Har

1992-07-01

A theoretical approach is developed for determining the capacitance and active resistance between the interacting surfaces of pivoted pads and thrust collar, under different conditions of operation. It is shown that resistance and capacitive reactance of a thrust bearing decrease with the number of pads times the values of these parameters for an individual pad, and that capacitance increases with the number of pads times the capacitance of an individual pad. The analysis presented has a potential to diagnose the behavior of pivoted pad thrust bearings with the angle of tilt and the ratio of film thickness at the leading to trailing edge, by determining the variation of capacitance, resistance, and capacitive reactance.

Detection of Helminth Eggs and Identification of Hookworm Species in Stray Cats, Dogs and Soil from Klang Valley, Malaysia.

Directory of Open Access Journals (Sweden)

Sandee Tun

Full Text Available The present study was conducted to determine the prevalence of helminth eggs excreted in the faeces of stray cats, dogs and in soil samples. A total of 505 fresh samples of faeces (from 227 dogs and 152 cats and soil were collected. The egg stage was detected via microscopy after the application of formalin-ether concentration technique. Genomic DNA was extracted from the samples containing hookworm eggs and used for further identification to the species level using real-time polymerase chain reaction coupled with high resolution melting analysis. Microscopic observation showed that the overall prevalence of helminth eggs among stray cats and dogs was 75.7% (95% CI = 71.2%-79.9%, in which 87.7% of dogs and 57.9% of cats were infected with at least one parasite genus. Five genera of heliminth eggs were detected in the faecal samples, including hookworms (46.4%, Toxocara (11.1%, Trichuris (8.4%, Spirometra (7.4% and Ascaris (2.4%. The prevalence of helminth infections among stray dogs was significantly higher than that among stray cats (p < 0.001. Only three genera of helminths were detected in soil samples with the prevalence of 23% (95% CI = 15.1%-31%, consisting of hookworms (16.6%, Ascaris (4% and Toxocara (2.4%. The molecular identification of hookworm species revealed that Ancylostoma ceylanicum was dominant in both faecal and soil samples. The dog hookworm, Ancylostoma caninum, was also detected among cats, which is the first such occurrence reported in Malaysia till date. This finding indicated that there was a cross-infection of A. caninum between stray cats and dogs because of their coexistent within human communities. Taken together, these data suggest the potential role of stray cats and dogs as being the main sources of environmental contamination as well as for human infections.

PENGARUH PEMBELAJARAN KOOPERATIF TWO STAY TWO STRAY BERPENDEKAT AN SETS TERHADAP HASIL BELAJAR KIMIA SISWA SMA NEGERI 1 COMAL

Directory of Open Access Journals (Sweden)

A. T. Setiawan

2016-07-01

Full Text Available Penelitian ini bertujuan untuk mengetahui pengaruh pembelajaran kooperatif two stay two stray berpendekatan SETS terhadap hasil belajar siswa. Desain eksperimen yang digunakan dalam penelitian ini adalah quasi experimental design. Hasil penelitian menunjukkan bahwa pembelajaran kooperatif two stay two stray berpendekatan SETS berpengaruh signitikan terhadap hasil belajar pada materi pokok teori asam basa dengan kontribusi koefisien determinasi sebesar 25%. Selain itu, pembelajaran juga mencapai ketuntasan belajar klasikal sebesar 37 dari 43 siswa, sehingga pembelajaran tersebut termasuk efektif.This study aimed to determine the effect of two stay two stray cooperative learning with SETS approach on student learning outcomes. Experimental design used in this study is a quasi experimental design. The results showed that two stay two stray cooperative learning with SETS approach have a significant effect on learning outcomes in acid-base theory of the subject matter with the contribution of the determination coefficient of 25%. In addition, the study also achieved mastery learning classical by 37 of the 43 students, so that it includes effective learning.

Ferroelectric negative capacitance domain dynamics

Science.gov (United States)

Hoffmann, Michael; Khan, Asif Islam; Serrao, Claudy; Lu, Zhongyuan; Salahuddin, Sayeef; Pešić, Milan; Slesazeck, Stefan; Schroeder, Uwe; Mikolajick, Thomas

2018-05-01

Transient negative capacitance effects in epitaxial ferroelectric Pb(Zr0.2Ti0.8)O3 capacitors are investigated with a focus on the dynamical switching behavior governed by domain nucleation and growth. Voltage pulses are applied to a series connection of the ferroelectric capacitor and a resistor to directly measure the ferroelectric negative capacitance during switching. A time-dependent Ginzburg-Landau approach is used to investigate the underlying domain dynamics. The transient negative capacitance is shown to originate from reverse domain nucleation and unrestricted domain growth. However, with the onset of domain coalescence, the capacitance becomes positive again. The persistence of the negative capacitance state is therefore limited by the speed of domain wall motion. By changing the applied electric field, capacitor area or external resistance, this domain wall velocity can be varied predictably over several orders of magnitude. Additionally, detailed insights into the intrinsic material properties of the ferroelectric are obtainable through these measurements. A new method for reliable extraction of the average negative capacitance of the ferroelectric is presented. Furthermore, a simple analytical model is developed, which accurately describes the negative capacitance transient time as a function of the material properties and the experimental boundary conditions.

Stray light suppression in the Goddard IRAM 2-Millimeter Observer (GISMO)

Science.gov (United States)

Sharp, E. H.; Benford, D. J.; Fixsen, D. J.; Moseley, S. H.; Staguhn, J. G.; Wollack, E. J.

2012-09-01

The Goddard-IRAM Superconducting 2 Millimeter Observer (GISMO) is an 8x16 Transition Edge Sensor (TES) array of bolometers built as a pathfinder for TES detector development efforts at NASA Goddard Space Flight Center. GISMO has been used annually at the Institut de Radioastronomie Millimétrique (IRAM) 30 meter telescope since 2007 under engineering time and was opened in the spring of 2012 to the general astronomical community. The spring deployment provided an opportunity to modify elements of the room temperature optics before moving the instrument to its new permanent position in the telescope receiver cabin. This allowed for the possibility to extend the cryostat, introduce improved cold baffling and thus further optimize the stray light performance for final astronomical use of the instrument, which has been completed and validated. We will demonstrate and discuss several of the methods used to quantify and limit the influence of stray light in the GISMO camera.

Aspheric surface measurement using capacitive probes

Science.gov (United States)

Tao, Xin; Yuan, Daocheng; Li, Shaobo

2017-02-01

With the application of aspheres in optical fields, high precision and high efficiency aspheric surface metrology becomes a hot research topic. We describe a novel method of non-contact measurement of aspheric surface with capacitive probe. Taking an eccentric spherical surface as the object of study, the averaging effect of capacitive probe measurement and the influence of tilting the capacitive probe on the measurement results are investigated. By comparing measurement results from simultaneous measurement of the capacitive probe and contact probe of roundness instrument, this paper indicates the feasibility of using capacitive probes to test aspheric surface and proposes the compensation method of measurement error caused by averaging effect and the tilting of the capacitive probe.

Gastrointestinal Helminths and Ectoparasites in the Stray Cats (Felidae: Felis catus) of Ahar Municipality, Northwestern Iran

Science.gov (United States)

YAKHCHALI, Mohammad; HAJIPOUR, Nasser; MALEKZADEH-VIAYEH, Reza; ESMAEILNEJAD, Bijan; NEMATI-HARAVANI, Taher; FATHOLLAHZADEH, Mohammad; JAFARI, Rasool

2017-01-01

Background: The stray cats are considered as the sources of emerging humans and domestic livestock pathogens and the zoonoses of public health importance. The present study was aimed to elucidate intestinal helminth infections and infestation with ectoparasites of the stray cats of Ahar City, northwestern Iran. Methods: Totally, 51 stray cats were randomly trapped from different parts of the city between Mar and Nov 2013. The cats were assessed for ectoparasites by hair brushing, skin scraping, acetate tape preparation and othic swabs. They were euthanized and inspected for helminths infection. Results: Overall prevalence of helminths and flea were 44/51 (86.3%) and 31/51 (60.78%), respectively. The infection rates were significantly different among different age groups (PDipylidium caninum (29.41%), T. hydatigena (19.6%)) were identified. The predominant infectious helminths in all the infected cats were T. cati (86.3% with egg per gram of feces 27.75±9). Of the 270 collected fleas, two species of Ctenocephalides felis (80%) and C. canis (20%) were notably frequent in the cats aged 2-3-year-old. The average number of fleas per each infected cat was recorded as 5.29, with no incidence of cross-infection. Conclusion: The results indicated the high rate of helminths infections and flea infestation in the urban stray cats of which Toxocara cati and Ctenocephalides felis may play important roles as zoonotic agents in the region. PMID:28761492

Molecular CsF 5 and CsF 2 +

KAUST Repository

Rogachev, Andrey Yu.; Miao, Mao-sheng; Merino, Gabriel; Hoffmann, Roald

2015-01-01

D5h star-like CsF5, formally isoelectronic with known XeF5− ion, is computed to be a local minimum on the potential energy surface of CsF5, surrounded by reasonably large activation energies for its exothermic decomposition to CsF+2 F2, or to CsF3 (three isomeric forms)+F2, or for rearrangement to a significantly more stable isomer, a classical Cs+ complex of F5−. Similarly the CsF2+ ion is computed to be metastable in two isomeric forms. In the more symmetrical structures of these molecules there is definite involvement in bonding of the formally core 5p levels of Cs.

Molecular CsF 5 and CsF 2 +

KAUST Repository

Rogachev, Andrey Yu.

2015-06-03

D5h star-like CsF5, formally isoelectronic with known XeF5− ion, is computed to be a local minimum on the potential energy surface of CsF5, surrounded by reasonably large activation energies for its exothermic decomposition to CsF+2 F2, or to CsF3 (three isomeric forms)+F2, or for rearrangement to a significantly more stable isomer, a classical Cs+ complex of F5−. Similarly the CsF2+ ion is computed to be metastable in two isomeric forms. In the more symmetrical structures of these molecules there is definite involvement in bonding of the formally core 5p levels of Cs.

Gastrointestinal helminth parasites of pet and stray dogs as a potential risk for human health in Bahir Dar town, north-western Ethiopia

Directory of Open Access Journals (Sweden)

Tadiwos Abere

Full Text Available Aim: A cross-sectional study was carried out from November 2011 to April 2012 to determine the prevalence and species of gastrointestinal (GI helminth parasites in pet and stray dogs as a potential risk for human health in Bahir Dar town, northwestern Ethiopia. Materials and Methods: A total of 384 and 46 faecal samples were collected from pet and stray dogs, respectively and xamined by using standard coprologic techniques. Results: The overall prevalence of GI helminth infection in pet and stray dogs was 75.26 and 84.78%, respectively. The detected parasites with their frequencies in pet dogs were Ancylostoma caninum (78.89%, Toxocara canis (39.79%, Dipylidium caninum (29.75%, Strongyloides stercoralis (29.06%, Taeniidae (23.87% and Trichuris vulpis (7.95%. Stray dogs were found more likely to be polyparasitized and presented higher prevalence of A. caninum, T. canis, S. stercoralis, Trichuris vulpis and Taeniidae (P < 0.05 than domiciled ones. Diphyllobothrium latum was detected only in 10.25% of stray dogs. Toxocara canis and A. caninum (P < 0.05 were detected more frequently in dogs with less than 6 months of age (P <0.05 than old age dogs. The sex or breed groups didn't significantly affect the prevalence of parasites. A significant variation was recorded (P < 0.05 between different feeding systems where higher prevalence was observed in uncontrolled feeding group (82.18% compared to controlled feeding (32.08%. Conclusion: Different gastrointestinal parasites in pet and stray dogs were identified in the study area that can potentially infect humans and cause serious public-health problems. Thus, concerted efforts should therefore be made to educate dog owners to embrace modern dog disease control programs and measures have to be taken on stray dogs. [Vet World 2013; 6(7.000: 388-392

THE SOCIETY’S PERCEPTION OF THE LIFE QUALITY AND POPULATION CONTROL OF STRAY DOGS

Directory of Open Access Journals (Sweden)

Flavio Fernando Batista Moutinho

2015-10-01

Full Text Available In most Brazilian municipalities there is an overpopulation of stray dogs, which causes problems to the urban order, the environment and the public health, in addition to mistreatment to these dogs. In such context we foresee the need of developing actions targeting the population control of these animals. This essay aims at knowing the perception of social actors, such as managers of entities responsible for control actions, managers of NGOs working with animal protection and population in general with respect to the life quality and population control of stray dogs. Questionnaires were used on samples of individuals of these three groups and the data thereof were analyzed with descriptive statistics techniques and frequency comparison. The results allowed us to conclude that the society’s perception of population control and life quality of these animals bear important differences under the viewpoint of the three evaluated groups; however, they also bear significant similarities, especially with respect to the perception of the responsibility for the development of population control actions, the acceptance of using public funds intended to public health in control actions, the classification of such population density as large and the poor life quality of these animals. population control, social perception, stray dog.,

Effect of stray current on corrosion behavior of reinforcing steel: importance of cell geometry and orientation with respect to the electrical field

NARCIS (Netherlands)

Chen, Zhipei; Koleva, D.A.

2016-01-01

Stray current circulating in reinforced concrete structures may initiate corrosion or accelerate existing corrosion processes on embedded reinforcement. In some cases, the range of dangerous or unwanted interactions of stray currents under favorable conditions (environment), is much broader than is

IMPLEMENTASI MODEL PEMBELAJARAN TWO STAY TWO STRAY DALAM PEMBELAJARAN BERBASIS KEMAMPUAN BERPIKIR KRITIS KELAS V SD

Directory of Open Access Journals (Sweden)

M. Yusuf Setia Wardana

2017-04-01

Full Text Available Benefits of mathematics are to equip students with the ability to think logically, analytical, systematically, critically, and creatively, as well as the ability to cooperate. Based on observations in elementary school, there are 40% of students have not reached KKM and students have lack of critical abilities to understand math problems, and they have low activity of the study. One of models that can be applied is Two Stay Two Stray. The study used True Experimental Design with Posttest-Only Control Design. The population in this study was all fifth grade students of SD Negeri Semarang Rejosari 03. Data of critical thinking skills of the students in average on test of critical thinking skills mastery was 3.31 ≥ 2.67, it can be said to have a complete description. The conclusion is a model of Two Stay Two Stray being effective for critical thinking skills and mathematics learning outcomes of fifth grade students in SD Negeri Rejosari 03 Semarang. Keywords: two stay two stray model, critical thinking ability.

Efficiency of Capacitively Loaded Converters

DEFF Research Database (Denmark)

Andersen, Thomas; Huang, Lina; Andersen, Michael A. E.

2012-01-01

This paper explores the characteristic of capacitance versus voltage for dielectric electro active polymer (DEAP) actuator, 2kV polypropylene film capacitor as well as 3kV X7R multi layer ceramic capacitor (MLCC) at the beginning. An energy efficiency for capacitively loaded converters...... is introduced as a definition of efficiency. The calculated and measured efficiency curves for charging DEAP actuator, polypropylene film capacitor and X7R MLCC are provided and compared. The attention has to be paid for the voltage dependent capacitive load, like X7R MLCC, when evaluating the charging...... polypropylene film capacitor can be the equivalent capacitive load. Because of the voltage dependent characteristic, X7R MLCC cannot be used to replace the DEAP actuator. However, this type of capacitor can be used to substitute the capacitive actuator with voltage dependent property at the development phase....

Capacitance of circular patch resonator

International Nuclear Information System (INIS)

Miano, G.; Verolino, L.; Naples Univ.; Panariello, G.; Vaccaro, V.G.; Naples Univ.

1995-11-01

In this paper the capacitance of the circular microstrip patch resonator is computed. It is shown that the electrostatic problem can be formulated as a system of dual integral equations, and the most interesting techniques of solutions of these systems are reviewed. Some useful approximated formulas for the capacitance are derived and plots of the capacitance are finally given in a wide range of dielectric constants

Symptoms and Cognitive Effects of Exposure to Magnetic Stray Fields of MRI Scanners

NARCIS (Netherlands)

Vocht, Frank Gérard de

2006-01-01

People working routinely with magnetic resonance imaging (MRI) systems report a number of symptoms related to their presence in the inhomogeneous static magnetic fields (the stray field) surrounding these scanners. Experienced symptoms and neurobehavioral performance among engineers manufacturing

Stray cats are more frequently infected with zoonotic protists than pet cats.

Science.gov (United States)

Kvac, Martin; Hofmannova, Lada; Ortega, Ynes; Holubova, Nikola; Horcickova, Michaela; Kicia, Marta; Hlaskova, Lenka; Kvetonova, Dana; Sak, Bohumil; McEvoy, John

2017-12-06

Faecal samples were collected from cats kept as pets (n = 120) and stray cats (n = 135) in Central Europe (Czech Republic, Poland and Slovakia) and screened for the presence of Cryptosporidium spp., Giardia intestinalis (Kunstler, 1882), Encephalitozoon spp. and Enterocytozoon bieneusi Desportes, Le Charpentier, Galian, Bernard, Cochand-Priollet, Lavergne, Ravisse et Modigliani, 1985 by PCR analysis of the small-subunit of rRNA (Cryptosporidium spp. and G. intestinalis) and ITS (microsporidia) genes. Sequence analysis of targeted genes revealed the presence of C. felis Iseki, 1979, G. intestinalis assemblage F, E. cuniculi Levaditi, Nicolau et Schoen, 1923 genotype II, and E. bieneusi genotype D. There was no correlation between the occurrence of detected parasites and sex, presence of diarrhoea or drug treatment (drug containing pyrantel and praziquantel). Compared to pet cats (7%), stray cats (30%) were statistically more frequently infected with protist parasites and overall may present a greater risk to human health.

Stray Cats Gastrointestinal Parasites and its Association With Public Health in Ahvaz City, South Western of Iran

Science.gov (United States)

Khademvatan, Shahram; Abdizadeh, Rahman; Rahim, Fakher; Hashemitabar, Mahamoud; Ghasemi, Mohammad; Tavalla, Mahdi

2014-01-01

Background: Cats are the hosts for some zoonotic parasites such as Toxoplasma gondii and Toxocara spp. which are important in medicine and veterinary. Studies on the prevalence of intestinal parasites of cats have received little attention in south west of Iran. Objectives: The current study aimed to investigate the prevalence of parasites in stray cats in Ahvaz. Materials and Methods: Random sampling was carried out from January to May 2012. One hundred and forty fecal samples from stray cats were examined using sucrose flotation method. Results: Gastrointestinal parasites were found in 121 of the 140 (86.4%) examined samples. The parasites detected in stray cats were Toxocara spp. (45%, 63/140), Isospora spp. (21.4%, 30/140), nematode larvae (21.4%, 30/140), Taenia spp. (18.6%, 26/140), Sarcocystis spp. (17.1%, 24/140), Eimeria spp. (15%, 21/140), Blastocystis spp. (14.3%, 20/140), Giardia spp, (10.7%, 15/140), Physaloptera spp. (7.1%, 10/140), and amoeba cyst (5.7%, 8/140) respectively. The prevalence of infection by Joyexiella spp. and hook worms (4.3%, 6/140), for example, Dipylidium caninum (2.9%, 4/140) was similar; and the prevalence of infection by T. gondii and Dicrocoelium dendriticum was similar (1.4%, 2/140). Conclusions: Since the prevalence of zoonotic gastrointestinal parasites such as Toxocara spp. in stray cats is high, there is a need to plan adequate programs to control these zoonotic parasites. PMID:25485047

Highly sensitive micromachined capacitive pressure sensor with reduced hysteresis and low parasitic capacitance

DEFF Research Database (Denmark)

Pedersen, Thomas; Fragiacomo, Giulio; Hansen, Ole

2009-01-01

This paper describes the design and fabrication of a capacitive pressure sensor that has a large capacitance signal and a high sensitivity of 76 pF/bar in touch mode operation. Due to the large signal, problems with parasitic capacitances are avoided and hence it is possible to integrate the sensor...... bonding to create vacuum cavities. The exposed part of the sensor is perfectly flat such that it can be coated with corrosion resistant thin films. Hysteresis is an inherent problem in touch mode capacitive pressure sensors and a technique to significantly reduce it is presented....... with a discrete components electronics circuit for signal conditioning. Using an AC bridge electronics circuit a resolution of 8 mV/mbar is achieved. The large signal is obtained due to a novel membrane structure utilizing closely packed hexagonal elements. The sensor is fabricated in a process based on fusion...

Stray dogs and cats as potential sources of soil contamination with zoonotic parasites

Directory of Open Access Journals (Sweden)

Katarzyna Szwabe

2017-03-01

Cat faeces represent a more important potential source of environmental contamination with zoonotic parasites than dog faeces. Among the detected parasites of stray dogs and cats, Toxocara present an important zoonotic risk for the local human population, especially children.

Evaluation of stray radiofrequency radiation emitted by electrosurgical devices

International Nuclear Information System (INIS)

De Marco, M; Maggi, S

2006-01-01

Electrosurgery refers to the passage of a high-frequency, high-voltage electrical current through the body to achieve the desired surgical effects. At the same time, these procedures are accompanied by a general increase of the electromagnetic field in an operating room that may expose both patients and personnel to relatively high levels of radiofrequency radiation. In the first part of this study, we have taken into account the radiation emitted by different monopolar electrosurgical devices, evaluating the electromagnetic field strength delivered by an electrosurgical handle and straying from units and other electrosurgical accessories. As a summary, in the worst case a surgeon's hands are exposed to a continuous and pulsed RF wave whose magnetic field strength is 0.75 A m -1 (E-field 400 V m -1 ). Occasionally stray radiation may exceed ICNIRP's occupational exposure guidelines, especially close to the patient return plate. In the second part of this paper, we have analysed areas of particular concern to prevent electromagnetic interference with some life-support devices (ventilators and electrocardiographic devices), which have failed to operate correctly. Most clinically relevant interference occurred when an electrosurgery device was used within 0.3 m of medical equipment. In the appendix, we suggest some practical recommendations intended to minimize the potential for electromagnetic hazards due to therapeutic application of RF energy

Gastrointestinal and ectoparasites from urban stray dogs in Fortaleza (Brazil): high infection risk for humans?

Science.gov (United States)

Klimpel, Sven; Heukelbach, Jörg; Pothmann, David; Rückert, Sonja

2010-08-01

Dogs are important definite or reservoir hosts for zoonotic parasites. However, only few studies on the prevalence of intestinal parasites in urban areas in Brazil are available. We performed a comprehensive study on parasites of stray dogs in a Brazilian metropolitan area. We included 46 stray dogs caught in the urban areas of Fortaleza (northeast Brazil). After euthanization, dogs were autopsied. Ectoparasites were collected, and the intestinal content of dogs were examined for the presence of parasites. Faecal samples were collected and analysed using merthiolate iodine formaldehyde concentration method. A total of nine different parasite species were found, including five endoparasite (one protozoan, one cestode and three nematode species) and four ectoparasite species (two flea, one louse and one tick species). In the intestinal content, 3,162 specimens of four helminth species were found: Ancylostoma caninum (prevalence, 95.7%), Dipylidium caninum (45.7%), Toxocara canis (8.7%) and Trichuris vulpis (4.3%). A total of 394 ectoparasite specimens were identified, including Rhipicephalus sanguineus (prevalence, 100.0%), Heterodoxus spiniger (67.4%), Ctenocephalides canis (39.1%) and Ctenocephalides felis (17.4%). In the faeces, intestinal parasites were detected in 38 stray dogs (82.6%), including oocysts of Giardia sp. (2.2%) and eggs of the nematode A. caninum (82.6%). Neither eggs nor larval stages of D. caninum, T. canis or T. vulpis were detected in dog faeces. Sensitivity of faecal examination for A. caninum was 86.4% (95% confidence interval, 72.0-94.3) but zero percentage for the other intestinal helminth species. Our data show that stray dogs in northeast Brazil carry a multitude of zoonotic ecto- and endoparasites, posing a considerable risk for humans. With the exception of A. caninum, sensitivity of faecal examination was negligible.

Capacitive Biosensors and Molecularly Imprinted Electrodes.

Science.gov (United States)

Ertürk, Gizem; Mattiasson, Bo

2017-02-17

Capacitive biosensors belong to the group of affinity biosensors that operate by registering direct binding between the sensor surface and the target molecule. This type of biosensors measures the changes in dielectric properties and/or thickness of the dielectric layer at the electrolyte/electrode interface. Capacitive biosensors have so far been successfully used for detection of proteins, nucleotides, heavy metals, saccharides, small organic molecules and microbial cells. In recent years, the microcontact imprinting method has been used to create very sensitive and selective biorecognition cavities on surfaces of capacitive electrodes. This chapter summarizes the principle and different applications of capacitive biosensors with an emphasis on microcontact imprinting method with its recent capacitive biosensor applications.

Molecular detection of Ehrlichia canis, Hepatozoon canis and Babesia canis vogeli in stray dogs in Mahasarakham province, Thailand.

Science.gov (United States)

Piratae, Supawadee; Pimpjong, Kiattisak; Vaisusuk, Kotchaphon; Chatan, Wasupon

2015-01-01

Canine tick borne diseases showing distribution worldwide have caused morbidity and mortality in dogs. This study observed the mainly tick borne pathogens described for dogs in Thailand, Ehrlichia canis, Hepatozoon canis and Babesia canis vogeli. From May to July 2014, blood samples were collected from 79 stray dogs from 7 districts of Mahasarakham province to molecular surveyed for 16s rRNA gene of E. canis and 18s rRNA gene of H. canis and B. canis vogeli. Twenty eight (35.44%) of stray dogs showed the infection with tick borne pathogens. The prevalence of E. canis infection was the highest with 21.5% (17/79). DNA of H. canis and B. canis vogeli were detected at the prevalence of 10.1% (8/79) and 6.3% (5/79), respectively. Co-infection between E. canis and B. canis vogeli were identified in 2 (2.5%) dogs. The results indicated that a wide range of tick borne pathogens are circulation in the canine population in Mahasarakham province. This study is the first report on prevalence of E. canis, H. canis and B. canis vogeli in stray dogs in Mahasarakham, a province in northern part of Thailand. This data providing is important to understand the prevalence of E. canis, H. canis and B. canis vogeli infection in stray dogs in this region, which will assist in the management of these blood parasite.

An estimate of the radiation-induced cancer risk from the whole-body stray radiation exposure in neutron radiotherapy

International Nuclear Information System (INIS)

Geraci, J.P.; Jackson, K.L.; Mariano, M.S.

1982-01-01

1980 BEIR III risk factors have been used to estimate the secondary cancer risks from the whole-body stray radiation exposures occurring in neutron radiotherapy. Risks were calculated using linear, linear-quadratic and quadratic dose-response models for the gamma component of the stray radiation. The linear dose-response model was used to calculate risk for the neutron component of the stray radiation. These estimates take into consideration for the first time the age and sex distribution of patients undergoing neutron therapy. Changes in risk as a function of the RBE (10-100) assigned to the stray neutron radiation component have also been assessed. Excess risks in neutron-treated patients have been compared with excess risks for photon-treated patients and with the expected incidence of cancer in a normal population having the same age and sex distribution. Results indicate that it will be necessary to tolerate a higher incidence of secondary cancers in patients undergoing fast neutron therapy than is the case with conventional photon therapy. For neutron RBEs of less than 50 the increased risk is only a fraction of the normal expected incidence of cancer in this population. Comparison of the radiation-induced risk with reported normal tissue complication rates in the treatment volume indicates that the excess cancer risk is substantially lower than the risk from other late normal tissue effects. (author)

Shielding of the NBI boxes against W7-X magnetic stray fields

Energy Technology Data Exchange (ETDEWEB)

Kick, Manfred [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany)], E-mail: Kick@arcor.de; Sielanko, Juliusz [Maria Curie Sklodowska University, Pl. M. C. Sklodowskie 1, 20-031 Lublin (Poland); Heinemann, Bernd; Riedl, Rudolf; Speth, Eckehart; Staebler, Albrecht [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany)

2009-06-15

Neutral Beam Injection (NBI), besides ECRH, is foreseen as one of the main heating devices at the W7-X stellarator currently under construction at IPP Greifswald, Germany. In a final stage 20 MW of NBI heating power will be installed generated by two NBI boxes of the ASDEX Upgrade (AUG) type. Since magnetic fields generally affect the trajectories of charged particles, essentially all the NBI boxes - including ion sources, acceleration sections, neutralisers and deflection magnets - must be shielded against the stray fields of W7-X. In the magnetic stray fields of W7-X there exist significant radial and toroidal components whereas at tokamaks the vertical components are dominant. The power loads on the ion dump and the protecting structures of the deflecting magnets and the beam lines caused by residual beam ions, therefore, will be strongly different. Thus the shielding concept of AUG cannot simply be taken over, but must be carefully redesigned in order to remain below the critical power limits. New modelling calculations of the magnetic shielding, the ion trajectories and the resulting power loads have been carried out for the 'high iota' and 'low shear' experimental scenarios of W7-X. The fields taken for these calculations are modelled by averaging the calculated W7-X stray fields on the one hand, and by fields generated by two-hypothetical-planar coils perpendicular to the x-y plane, on the other hand. The shielding concept for W7-X mainly consist of iron plates in the outer side regions of the boxes and as little magnetic material as possible inside the boxes.

Stray animal populations and public health in the South Mediterranean and the Middle East regions

Directory of Open Access Journals (Sweden)

Aristarhos Seimenis

2014-06-01

Full Text Available Uncontrolled urban growth in South Mediterranean and the Middle East regions involves city dwellers and stray animals (mainly dogs and cats creating a dense and downgraded environment, in which irregular street garbage collection disposes sufficient food for survival and proliferation of stray animals. Under such conditions serious public health hazards are expected due to the increase of animal bites, the multiplication of insects and rodents vectors of different viral, bacterial, fungal and parasitic agents to which humans are exposed. Traditional national stray animal eradication programs and occasional small animals' humane elimination campaigns are insufficient to avert human and veterinary health risks when not coupled with modern technologies. In such environments, multiple foci of emerging and re‑emerging zoonoses easily spread, i.e. rabies, hydatidosis, leishmaniasis and toxoplasmosis. Upgrading urban and peri-urban situations requires integrated/coordinated management programmes, in which public and animal health services as well as municipalities have a crucial role. Control and upgrading programmes should be flexible and able to adapt to the specific conditions of the given country/region. In this context, intersectoral/interprofessional collaborations and community participation are crucial for any national and regional development strategies. In this respect, a global approach considering both public health and socio-economic problems shows to be extremely adequate and effective.

Problems Associated with the Microchip Data of Stray Dogs and Cats Entering RSPCA Queensland Shelters

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Emily Lancaster

2015-05-01

Full Text Available A lack of published information documenting problems with the microchip data for the reclaiming of stray animals entering Australian shelters limits improvement of the current microchipping system. A retrospective study analysing admission data for stray, adult dogs (n = 7258 and cats (n = 6950 entering the Royal Society for the Prevention of Cruelty to Animals (RSPCA Queensland between January 2012 and December 2013 was undertaken to determine the character and frequency of microchip data problems and their impact on outcome for the animal. Only 28% of dogs and 9% of cats were microchipped, and a substantial proportion (37% had problems with their data, including being registered to a previous owner or organisation (47%, all phone numbers incorrect/disconnected (29%, and the microchip not registered (14%. A higher proportion of owners could be contacted when the microchip had no problems, compared to those with problems (dogs, 93% vs. 70%; cats, 75% vs. 41%. The proportion of animals reclaimed declined significantly between microchipped animals with no data problems, microchipped animals with data problems and non-microchipped animals—87%, 69%, and 37%, respectively, for dogs and 61%, 33%, and 5%, respectively, for cats. Strategies are needed to increase the accuracy of microchip data to facilitate the reclaiming of stray dogs and cats.

Nanoscale capacitance: A quantum tight-binding model

Science.gov (United States)

Zhai, Feng; Wu, Jian; Li, Yang; Lu, Jun-Qiang

2017-01-01

Landauer-Buttiker formalism with the assumption of semi-infinite electrodes as reservoirs has been the standard approach in modeling steady electron transport through nanoscale devices. However, modeling dynamic electron transport properties, especially nanoscale capacitance, is a challenging problem because of dynamic contributions from electrodes, which is neglectable in modeling macroscopic capacitance and mesoscopic conductance. We implement a self-consistent quantum tight-binding model to calculate capacitance of a nano-gap system consisting of an electrode capacitance C‧ and an effective capacitance Cd of the middle device. From the calculations on a nano-gap made of carbon nanotube with a buckyball therein, we show that when the electrode length increases, the electrode capacitance C‧ moves up while the effective capacitance Cd converges to a value which is much smaller than the electrode capacitance C‧. Our results reveal the importance of electrodes in modeling nanoscale ac circuits, and indicate that the concepts of semi-infinite electrodes and reservoirs well-accepted in the steady electron transport theory may be not applicable in modeling dynamic transport properties.

Gastrointestinal Helminths and Ectoparasites in the Stray Cats (Felidae: Felis catus of Ahar Municipality, Northwestern Iran

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Mohammad YAKHCHALI

2017-06-01

Full Text Available Background: The stray cats are considered as the sources of emerging humans and domestic livestock pathogens and the zoonoses of public health importance. The present study was aimed to elucidate intestinal helminth infections and infestation with ectoparasites of the stray cats of Ahar City, northwestern Iran.Methods: Totally, 51 stray cats were randomly trapped from different parts of the city between Mar and Nov 2013. The cats were assessed for ectoparasites by hair brushing, skin scraping, acetate tape preparation and othic swabs. They were euthanized and inspected for helminths infection.Results: Overall prevalence of helminths and flea were 44/51 (86.3% and 31/51 (60.78%, respectively. The infection rates were significantly different among different age groups (P<0.05. Of the 282 isolated helminths, three species of nematodes (Toxocara cati (86.3%, T. leonina (11.77%, Ancylostoma tubaeforme (5.9% and four species of cestodes (Taenia taeniaeformis (64.7%, Mesocestoides lineatus (49.02%, Dipylidium caninum (29.41%, T. hydatigena (19.6% were identified. The predominant infectious helminths in all the infected cats were T. cati (86.3% with egg per gram of feces 27.75±9. Of the 270 collected fleas, two species of Ctenocephalides felis (80% and C. canis (20% were notably frequent in the cats aged 2-3-year-old. The average number of fleas per each infected cat was recorded as 5.29, with no incidence of cross-infection.Conclusion: The results indicated the high rate of helminths infections and flea infestation in the urban stray cats of which Toxocara cati and Ctenocephalides felis may play important roles as zoonotic agents in the region.

Capacitive Sensing of Glucose in Electrolytes Using Graphene Quantum Capacitance Varactors.

Science.gov (United States)

Zhang, Yao; Ma, Rui; Zhen, Xue V; Kudva, Yogish C; Bühlmann, Philippe; Koester, Steven J

2017-11-08

A novel graphene-based variable capacitor (varactor) that senses glucose based on the quantum capacitance effect was successfully developed. The sensor utilizes a metal-oxide-graphene varactor device structure that is inherently compatible with passive wireless sensing, a key advantage for in vivo glucose sensing. The graphene varactors were functionalized with pyrene-1-boronic acid (PBA) by self-assembly driven by π-π interactions. Successful surface functionalization was confirmed by both Raman spectroscopy and capacitance-voltage characterization of the devices. Through glucose binding to the PBA, the glucose concentration in the buffer solutions modulates the level of electrostatic doping of the graphene surface to different degrees, which leads to capacitance changes and Dirac voltage shifts. These responses to the glucose concentration were shown to be reproducible and reversible over multiple measurement cycles, suggesting promise for eventual use in wireless glucose monitoring.

Monitoring DC stray current interference of steel sheet pile structures in railway environment

NARCIS (Netherlands)

Peelen, W.H.A.; Neeft, E.A.C.; Leegwater, G.; Kanten-Roos, W. van; Courage, W.M.G.

2011-01-01

Steel structures near DC powered railways are expected to be affected by stray current interference. This causes accelerated corrosion rates. Therefore steel is often not used as a building material in these cases, although certain advantages over the alternative material concrete exist. These

Seroprevalence and Risk Factors Associated with Seropositivity to Toxoplasma gondii among Stray and Domestic Cats (Felis silvestris catus

Directory of Open Access Journals (Sweden)

Christel Bohn T. Garcia

2014-12-01

Full Text Available Toxoplasma gondii is a protozoan parasite that causes toxoplasmosis. It is widespread in the environment and infects a variety of warm-blooded animals, causing miscarriages and birth problems. Previous studies in the Philippines have determined the seropositivity of T. gondii in humans. However, the seroprevalence of the parasite among household pets, par ticularly its feline def initive host, remains insufficient . This study aimed to: (1 determine the seroprevalence of T. gondii antibodies among domestic and stray cats in the Philippines; and, (2 to analyze the risk factors associated with seropositivity. Blood samples from 59 domestic and stray cats were collected and tested for T. gondii seropositivity using a commercially available indirect ELISA kit, while pet owners and handlers were given questionnaires about their cats. Thirteen or 22.03% of the cats were seropositive to T. gondii, and risk factor analysis revealed a significant difference between domestic and stray cats with regard to diet (p = 0.026, OR = 8.333, c = 0.299 and domestication (p = 0.039, OR = 5.000, c = 0.276. Cats fed with table food tested 31.43% seropositive compared to the 4.35% of those fed with cat food, whereas 33.33% of the stray cats were seropositive compared to 7.69% for domestic cats. Odds ratio test showed that the risk factors studied were associated with higher likelihood of T. gondii seropositivity. These results implicate diet and environment in the transmission dynamics of T. gondii among cats.

Effects of different levels of intraocular stray light on kinetic perimetry findings.

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Kazunori Hirasawa

Full Text Available To evaluate the effect of different levels of intraocular stray light on kinetic perimetry findings.Twenty-five eyes of 25 healthy young participants were examined by automated kinetic perimetry (Octopus 900 using Goldmann stimuli III4e, I4e, I3e, I2e, and I1e. Each stimulus was presented with a velocity of 3°/s at 24 meridians with 15° intervals. Four levels of intraocular stray light were induced using non-white opacity filter (WOF filters and WOFs applied to the clear plastic eye covers of the participants. The visual acuity, pupil diameter, isopter area, and kinetic sensitivity of each meridian were analyzed for each WOF density.Visual acuity deteriorated with increasing WOF densities (p < 0.01. With a visual acuity of 0.1 LogMAR units, the isopter areas for III4e, I4e, I3e, I2e, and I1e decreased by -32.7 degree2 (-0.2%, -255.7 degree2 (-2.6%, -381.2 degree2 (-6.2%, -314.8 degree2 (-12.8%, and -59.2 degree2 (-15.2%, respectively; kinetic sensitivity for those stimuli decreased by -0.1 degree (-0.1%, -0.8 degree (-1.4%, -1.6 degree (-3.7%, -2.7 degree (-9.7%, and -1.7 degree (-16.2%, respectively. The pupil diameter with each WOF density was not significantly different.Kinetic perimetry measurements with a high-intensity stimulus (i.e., III4e were unaffected by intraocular stray light. In contrast, measurements with the I4e, I3e, I2e, and I1e stimuli, especially I2e and I1e, were affected. Changes in the shape of the isopter resulting from opacity must be monitored, especially in cases of smaller and lower-intensity stimuli.

Carbon flow electrodes for continuous operation of capacitive deionization and capacitive mixing energy generation

NARCIS (Netherlands)

Porada, S.; Hamelers, H.V.M.; Bryjak, M.; Presser, V.; Biesheuvel, P.M.; Weingarth, D.

2014-01-01

Capacitive technologies, such as capacitive deionization and energy harvesting based on mixing energy (“capmix” and “CO2 energy”), are characterized by intermittent operation: phases of ion electrosorption from the water are followed by system regeneration. From a system application point of view,

Decoding of digital magnetic recording with longitudinal magnetization of a tape from a magneto-optical image of stray fields

Science.gov (United States)

Lisovskii, F. V.; Mansvetova, E. G.

2017-05-01

For digital magnetic recording of encoded information with longitudinal magnetization of the tape, the connection between the domain structure of a storage medium and magneto-optical image of its stray fields obtained using a magnetic film with a perpendicular anisotropy and a large Faraday rotation has been studied. For two-frequency binary code without returning to zero, an algorithm is developed, that allows uniquely decoding of the information recorded on the tape based on analysis of an image of stray fields.

An epidemiological survey on intestinal helminths of stray dogs in Mashhad, North-east of Iran.

Science.gov (United States)

Emamapour, Seyed Rasoul; Borji, Hassan; Nagibi, Abolghasem

2015-06-01

This research was conducted to determine the prevalence of gastrointestinal helminths in stray dogs in the northeast of Iran, with special attention to those parasites that can be transmitted to human. In this experiment, a total of 72 adult and 18 juvenile stray dogs were collected and necropsied for the presence of helminth parasites from October 2011 to August 2012. The overall prevalence of gastrointestinal helminths was 86 % (95 % CI: 79.2-92.8 %). The observed helminths of the gastrointestinal tract were listed as follows: Toxocara canis (29 %), Toxascaris leonina (7 %), Ancylostoma caninum (2 %), Taenia hydatigena (43 %), Dipylidium caninum (39 %), Echinococcus granulosus (38 %), Mesocestoides lineatus (16 %), Taenia multiceps (11 %), Taenia ovis (3 %). There were no significant differences for the prevalence of gastrointestinal helminths between female (83.6 %) and male (89.7 %) and between young (89 %) and adult (72.2 %) animals. However, the prevalence of E. granulosus, T. hydatigena and D. caninum showed an increasing trend with increasing host age, significantly. Based on our data, it is important to point out the presence of zoonotic agents, namely E. granulosus and T. canis in stray dogs in the investigated area. Due to its impact on public health, appropriate control measures should be taken and it is recommended to determine the most appropriate preventive methods.

Experimental investigation of the ECRH stray radiation during the start-up phase in Wendelstein 7-X

Science.gov (United States)

Moseev, Dmitry; Laqua, Heinrich; Marsen, Stefan; Stange, Torsten; Braune, Harald; Erckmann, Volker; Gellert, Florian; Oosterbeek, Johann Wilhelm; Wenzel, Uwe

2017-07-01

Electron cyclotron resonance heating (ECRH) is the main heating mechanism in the Wendelstein 7-X stellarator (W7-X). W7-X is equipped with five absolutely calibrated sniffer probes that are installed in each of the five modules of the device. The sniffer probes monitor energy flux of unabsorbed ECRH radiation in the device and interlocks are fed with the sniffer probe signals. The stray radiation level in the device changes significantly during the start-up phase: plasma is a strong microwave absorber and during its formation the stray radiation level in sniffer probes reduces by more than 95%. In this paper, we discuss the influence of neutral gas pressure and gyrotron power on plasma breakdown processes.

Comparison of stray light in spectrometer systems using a low cost monochromatic light source

DEFF Research Database (Denmark)

Thorseth, Anders; Lindén, Johannes; Dam-Hansen, Carsten

2014-01-01

We present an experimental setup that is under development for automated stray light characterization of spectrometers. The setup uses a tuneable monochromator which enables this characterization on relatively cost low equipment. We present the measured line spread functions for two spectrometers...

Prevalence of Protozoa and Gastrointestinal Helminthes in Stray Cats in Zanjan Province, North-West of Iran

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SA Altome

2009-07-01

Full Text Available Background: Cats and other felines act as definitive hosts for many intestinal parasites, some of which are responsible for several zoonotic diseases.  The aim of this study was to determine the type and prevalence of protozoa and gastrointestinal helminthes among stray cats. Methods: A cross sectional study was conducted. Digestive tracts of 100 stray cats in Zanjan Province, north-west of Iran were autopsied in order to recognize gastrointestinal helminthes and intestinal protozoan parasites. These cats were collected by baited cage trapped from October 2007 to September 2008. Gender and species of helminthes and protozoa were rec­ognized using authentic diagnostic criteria. Statistical evaluation was performed by SPSS version 14. Results: Forty-two percent of cats were infected with intestinal protozoan parasites, 33% were infected with cestodes and 39% infected with gastrointestinal nematodes. Four species protozoan parasites and eight gastrointestinal helminthes were recovered from the animals, including Taenia taeniaeformis, Dipylidium spp., Joyeuxiella pasqaulei, Toxocara cati, Phy­saloptera praeputialis, Rectalaria spp., Onicolla, Cystoisospora spp., Toxoplasma gondii, and Sarcocystis spp . Conclusions: The high infection rate of Toxoplasma and some gastrointestinal helminthes in stray cats is considered to be critical from the viewpoint of public health importance.

Prevalence of zoonotic intestinal parasites in household and stray dogs in rural areas of Hamadan, Western Iran.

Science.gov (United States)

Sardarian, K; Maghsood, A H; Ghiasian, S A; Zahirnia, A H

2015-06-01

Zoonotic parasitic infections are a major global public and veterinary health problem and widespread among dogs. The objective of this study was to assess the prevalence of intestinal parasites in stray and household dogs in the rural areas of Hamadan district. During 2012, 1,500 fresh fecal samples from 243 household and 1,257 stray dogs were examined by using direct wet mount, simple zinc sulfate flotation, and Lugol's solution staining. Of 1,500 dogs, 20.4% were positive for intestinal parasites. Helminthes eggs were more frequently found in fecal samples than protozoan cysts or trophozoites (15.9% vs. 4.5%, respectively). Toxocara canis was the most frequently detected parasite, with a prevalence of 6.3%, followed by Taenia/Echinococcus spp. (2.9%), Isospora spp. (2.7%), and Toxascaris leonina (2.6%). Helminthes and protozoa were significantly more prevalent in household dogs than in stray dogs (Pparasites indicated that people residing in this area are at risk of exposure to these potentially hazardous zoonotic pathogens. Mass education of the general population is highly recommended to increase awareness of the potential for horizontal transmission of these parasitic infections from dogs to humans.

The Capacitive Magnetic Field Sensor

Science.gov (United States)

Zyatkov, D. O.; Yurchenko, A. V.; Balashov, V. B.; Yurchenko, V. I.

2016-01-01

The results of a study of sensitive element magnetic field sensor are represented in this paper. The sensor is based on the change of the capacitance with an active dielectric (ferrofluid) due to the magnitude of magnetic field. To prepare the ferrofluid magnetic particles are used, which have a followingdispersion equal to 50 brand 5BDSR. The dependence of the sensitivity of the capacitive element from the ferrofluid with different dispersion of magnetic particles is considered. The threshold of sensitivity and sensitivity of a measuring cell with ferrofluid by a magnetic field was determined. The experimental graphs of capacitance change of the magnitude of magnetic field are presented.

Virtual electrical capacitance tomography sensor

International Nuclear Information System (INIS)

Li, Y; Yang, W Q

2005-01-01

Electrical capacitance tomography (ECT) is an effective technique for elucidating the distribution of dielectric materials inside closed pipes or vessels. This paper describes a virtual electrical capacitance tomography (VECT) system, which can simulate a range of sensor and hardware configurations and material distributions. A selection of popular image reconstruction algorithms has been made available and image error and capacitance error tools enable their performance to be evaluated and compared. Series of frame-by-frame results can be stored for simulating real-time dynamic flows. The system is programmed in Matlab with DOS functions. It is convenient to use and low-cost to operate, providing an effective tool for engineering experiment

Flexible PVDF ferroelectric capacitive temperature sensor

KAUST Repository

Khan, Naveed

2015-08-02

In this paper, a capacitive temperature sensor based on polyvinylidene fluoride (PVDF) capacitor is explored. The PVDF capacitor is characterized below its Curie temperature. The capacitance of the PVDF capacitor changes vs temperature with a sensitivity of 16pF/°C. The linearity measurement of the capacitance-temperature relation shows less than 0.7°C error from a best fit straight line. An LC oscillator based temperature sensor is demonstrated based on this capacitor.

Generation of strong inhomogeneous stray fields by high-anisotropy permanent magnets

Energy Technology Data Exchange (ETDEWEB)

Samofalov, V.N. [National Technical University Kharkov Polytechnical Institute, 21 Frunze St., 61002 Kharkov (Ukraine)]. E-mail: samofalov@kpi.kharkov.ua; Ravlik, A.G. [National Technical University Kharkov Polytechnical Institute, 21 Frunze St., 61002 Kharkov (Ukraine); Belozorov, D.P. [National Scientific Center Kharkov Institute of Physics and Techonology, NAS of Ukraine, 1 Akademicheskaja St., 61108 Kharkov (Ukraine); Avramenko, B.A. [National Technical University Kharkov Polytechnical Institute, 21 Frunze St., 61002 Kharkov (Ukraine)

2004-10-01

Magnetic stray fields for systems of permanent magnets with high magnetic anisotropy are calculated and measured. It is shown that intensity of these fields exceeds value of an induction of a material of magnets in some time. Besides, these fields are characterized by high gradients, and size H-bar H can reach values up to10{sup 10}-10{sup 11}Oe{sup 2}/cm. Estimations of extremely achievable fields and their gradients are made.

Detailed Electrochemical Characterisation of Large SOFC Stacks

DEFF Research Database (Denmark)

Mosbæk, Rasmus Rode; Hjelm, Johan; Barfod, R.

2012-01-01

application of advanced methods for detailed electrochemical characterisation during operation. An operating stack is subject to steep compositional gradients in the gaseous reactant streams, and significant temperature gradients across each cell and across the stack, which makes it a complex system...... Fuel Cell A/S was characterised in detail using electrochemical impedance spectroscopy. An investigation of the optimal geometrical placement of the current probes and voltage probes was carried out in order to minimise measurement errors caused by stray impedances. Unwanted stray impedances...... are particularly problematic at high frequencies. Stray impedances may be caused by mutual inductance and stray capacitance in the geometrical set-up and do not describe the fuel cell. Three different stack geometries were investigated by electrochemical impedance spectroscopy. Impedance measurements were carried...

Stray-field-induced Faraday contributions in wide-field Kerr microscopy and -magnetometry

International Nuclear Information System (INIS)

Markó, D.; Soldatov, I.; Tekielak, M.; Schäfer, R.

2015-01-01

The magnetic domain contrast in wide-field Kerr microscopy on bulk specimens can be substantially distorted by non-linear, field-dependent Faraday rotations in the objective lens that are caused by stray-field components emerging from the specimen. These Faraday contributions, which were detected by Kerr-magnetometry on grain-oriented iron–silicon steel samples, are thoroughly elaborated and characterized. They express themselves as a field-dependent gray-scale offset to the domain contrast and in highly distorted surface magnetization curves if optically measured in a wide field Kerr microscope. An experimental method to avoid such distortions is suggested. In the course of these studies, a low-permeability part in the surface magnetization loop of slightly misoriented (110)-surfaces in iron–silicon sheets was discovered that is attributed to demagnetization effects in direction perpendicular to the sheet surface. - Highlights: • Magnetizing a finite sample in a Kerr microscope leads to sample-generated stray-fields. • They cause non-linear, field- and position-dependent Faraday rotations in the objective. • This leads to a modulation of the Kerr contrast and to distorted MOKE loops. • A method to compensate these Faraday rotations is presented

Antibodies derived from an enterotoxigenic Escherichia coli (ETEC) adhesin tip MEFA (multiepitope fusion antigen) against adherence of nine ETEC adhesins: CFA/I, CS1, CS2, CS3, CS4, CS5, CS6, CS21 and EtpA.

Science.gov (United States)

Nandre, Rahul M; Ruan, Xiaosai; Duan, Qiangde; Sack, David A; Zhang, Weiping

2016-06-30

Diarrhea continues to be a leading cause of death in children younger than 5 years in developing countries. Enterotoxigenic Escherichia coli (ETEC) is a leading bacterial cause of children's diarrhea and travelers' diarrhea. ETEC bacteria initiate diarrheal disease by attaching to host receptors at epithelial cells and colonizing in small intestine. Therefore, preventing ETEC attachment has been considered the first line of defense against ETEC diarrhea. However, developing vaccines effectively against ETEC bacterial attachment encounters challenge because ETEC strains produce over 23 immunologically heterogeneous adhesins. In this study, we applied MEFA (multiepitope fusion antigen) approach to integrate epitopes from adhesin tips or adhesive subunits of CFA/I, CS1, CS2, CS3, CS4, CS5, CS6, CS21 and EtpA adhesins and to construct an adhesin tip MEFA peptide. We then examined immunogenicity of this tip MEFA in mouse immunization, and assessed potential application of this tip MEFA for ETEC vaccine development. Data showed that mice intraperitoneally immunized with this adhesin tip MEFA developed IgG antibody responses to all nine ETEC adhesins. Moreover, ETEC and E. coli bacteria expressing these nine adhesins, after incubation with serum of the immunized mice, exhibited significant reduction in attachment to Caco-2 cells. These results indicated that anti-adhesin antibodies induced by this adhesin tip MEFA blocked adherence of the most important ETEC adhesins, suggesting this multivalent tip MEFA may be useful for developing a broadly protective anti-adhesin vaccine against ETEC diarrhea. Copyright © 2016 Elsevier Ltd. All rights reserved.

Molecular CsF{sub 5} and CsF{sub 2}{sup +}

Energy Technology Data Exchange (ETDEWEB)

Rogachev, Andrey Yu. [Illinois Institute of Technology, IL (United States). Dept. of Biological and Chemical Sciences; Miao, Mao-sheng [California State Univ., Northridge, CA (United States). Dept. of Chemistry and Biochemistry; Beijing Computational Science Research Center (China); Merino, Gabriel [Centro de Investigacion y de Estudios Avanzados, Unidad Merida (Mexico). Dept. de Fisica Aplicada; Hoffmann, Roald [Cornell Univ., Ithaca, NY (United States). Dept. of Chemistry and Chemical Biology

2015-07-06

D{sub 5h} star-like CsF{sub 5}, formally isoelectronic with known XeF{sub 5}{sup -} ion, is computed to be a local minimum on the potential energy surface of CsF{sub 5}, surrounded by reasonably large activation energies for its exothermic decomposition to CsF + 2F{sub 2}, or to CsF{sub 3} (three isomeric forms) + F{sub 2}, or for rearrangement to a significantly more stable isomer, a classical Cs{sup +} complex of F{sub 5}{sup -}. Similarly the CsF{sub 2}{sup +} ion is computed to be metastable in two isomeric forms. In the more symmetrical structures of these molecules there is definite involvement in bonding of the formally core 5p levels of Cs.

Analysis of 137Cs radionuclides activities in Cs-zeolite using gamma spectrometry

International Nuclear Information System (INIS)

Noviarty; Ginting, Aslina Br; Anggraini, Dian; Rosika K

2013-01-01

137 Cs Radionuclide activity analysis has been carried out. The objective is to determine the activity of the 137 Cs radionuclide in Cs-zeolite are packaged in the form of point source. Analysis of 137 Cs Radionuclide activities in Cs zeolite samples was determined by measuring intensity of the isotope 137 Cs gamma energy at 661.7 keV use-y spectrometer. Before measurement the sample, was first carried out measurements of 137 Cs radionuclide in certified point standards from Amersham, to determine the efficiency value. Result the standard sample measurement obtained the efficiency value of 43.98%. Efficiency values obtained are used in the calculation of sample activity. On the measurement of the intensity of the sample obtained results dose rate 196.4537 cps with a standard deviation of 0.5274. By using standard measurement efficiency values obtained by the calculation of the average activity of the radionuclide 137 Cs in Cs-zeolite 524.9082 Bq. Deviation measurements were below 5% (0.27% ) so that the analysis of the activity of radionuclide 137 Cs in Cs-zeolite samples using gamma spectrometer can be accepted with a 95% confidence level. (author)

Investigations of prevalence of antibodies to B.canis in stray dogs in territory of Belgrade

Directory of Open Access Journals (Sweden)

Radojičić Sonja

2006-01-01

Full Text Available The paper covers investigations of stray dogs in the territory of the city of Belgrade. A total of 184 blood serum samples were examined for the presence of antibodies specific to Brucella canis. The method of slow agglutination in a test tube with 2- mercaptoethanol was used in the diagnostic procedure. Of the 184 examined serums, 49 (26.63% had a titer of 1/50, 25 serums had a titer of 1/100 (13.58%, while 20 serums had a titer equal to or bigger than 1/200 (10.87%. Furthermore, 15 samples of full blood from serologiclly negative animals were also presented for isolation. The bacteriological finding for these samples was negative. The obtained results indicate that the number of seropositive stray dogs in the territory of Belgrade is extremely high and that 10.87% of the testes animals are definitely infected with Brucella canis.

The Design, Construction and Test of stray light suppression baffles for the CHAMP satellite

DEFF Research Database (Denmark)

Jørgensen, John Leif

1997-01-01

The Advanced Stellar Compass, to be delivered from IAU to the CHAMP project, requires some kind of stray-light suppressing shade to be mounted in front of the lens, in order to minimize the thermal impact and to maximize the performance envelope when subjected to non-stellar external light sources...

Dosimeter charging and/or reading apparatus

International Nuclear Information System (INIS)

Fine, L.T.; Jackson, T.P.

1980-01-01

A device is disclosed for charging and/or reading a capacitor associated with an electrometer incorporated in a radiation dosimeter for the purpose of initializing or ''zeroing'', the dosimeter at the commencement of a radiation measurement cycle or reading it at any time thereafter. The dosimeter electrometer has a movable electrode the position of which is indicative of the charge remaining on the dosimeter capacitor and in turn the amount of radiation incident on the dosimeter since it was zeroed. The charging device also includes means for discharging, immediately upon conclusion of the dosimeter capacitor charging operation, stray capacitance inherent in the dosimeter by reason of its mechanical construction. The charge on the stray capacitance, if not discharged at the conclusion of the dosimeter capacitor charging operation, leaks off during the measurement cycle, introducing measurement errors. A light source and suitable switch means are provided for automatically illuminating the movable electrode of the dosimeter electrometer as an incident to charging the dosimeter capacitor to facilitate reading the initial, or ''zero'', position of the movable electrometer electrode after the dosimeter capacitor has been charged and the stray capacitance discharged. Also included is a manually actuatable switch means, which is operable independently of the aforementioned automatic switch means, to energize the lamp and facilitate reading of the dosimeter without charging

Helminth Infections of Stray Dogs from Garmsar, Semnan Province, Central Iran

Science.gov (United States)

Eslami, A; Ranjbar-Bahadori, Sh; Meshgi, B; Dehghan, M; Bokaie, S

2010-01-01

Background The aim was to study the gastro-intestinal helminths of stray dogs of Garmsar, Semnan Province, Central Iran, and its impacts on human health and animal production. Methods During 2006, the alimentary tracts of 50 stray dogs at necropsy, selected from villages around Garmsar, were removed, and examined for helminth infections. Subsequently helminths were collected from the contents of each part and scraped sample of small intestines of washed materials in a 100-mesh sieve. To identify the species of helminths, the nematodes were cleared in lactophenol and cestodes were stained using carmine acid. Results Mixed infection was the rule and 40 dogs (80%) harbored more than one species of helminth. Taenia hydatigena was the most prevalent species (80%) followed by Echinococcus granulosus (64%), Toxocara canis (22%), Mesocestoides lineatus (12%), Taenia multiceps (10%) and Dipylidium caninum (4%). The mean intensity of worm infection was low (1–3) except for that of E. granulosus (645). No significant difference was noticed between sex, age and most helminth infections except for that of sex and T. hydatigena (P=0.001) as well as age and T. canis (P=0.001). Conclusion Although human infection with T. hydatigena is unlikely, but other helminths reported in this study are of zoonotic importance, and may pose a threat to community health, and reduce the productions of ruminants harboring taeniid metacestodes. PMID:22347264

Fast space-varying convolution using matrix source coding with applications to camera stray light reduction.

Science.gov (United States)

Wei, Jianing; Bouman, Charles A; Allebach, Jan P

2014-05-01

Many imaging applications require the implementation of space-varying convolution for accurate restoration and reconstruction of images. Here, we use the term space-varying convolution to refer to linear operators whose impulse response has slow spatial variation. In addition, these space-varying convolution operators are often dense, so direct implementation of the convolution operator is typically computationally impractical. One such example is the problem of stray light reduction in digital cameras, which requires the implementation of a dense space-varying deconvolution operator. However, other inverse problems, such as iterative tomographic reconstruction, can also depend on the implementation of dense space-varying convolution. While space-invariant convolution can be efficiently implemented with the fast Fourier transform, this approach does not work for space-varying operators. So direct convolution is often the only option for implementing space-varying convolution. In this paper, we develop a general approach to the efficient implementation of space-varying convolution, and demonstrate its use in the application of stray light reduction. Our approach, which we call matrix source coding, is based on lossy source coding of the dense space-varying convolution matrix. Importantly, by coding the transformation matrix, we not only reduce the memory required to store it; we also dramatically reduce the computation required to implement matrix-vector products. Our algorithm is able to reduce computation by approximately factoring the dense space-varying convolution operator into a product of sparse transforms. Experimental results show that our method can dramatically reduce the computation required for stray light reduction while maintaining high accuracy.

'Wash-out' of Cs-134 and Cs-137 from river sediment; 'Ispiranja' Cs-134 i Cs-137 iz recnog sedimenta

Energy Technology Data Exchange (ETDEWEB)

Skrbic, Z; Conkic, Lj; Bikit, I; Veskovic, M; Slivka, J; Marinkov, L [Institut za Fiziku, Novi Sad Univ. (Yugoslavia)

1988-07-01

Natural elimination and 'wash out' period of the Cs-134 and Cs-137 from the river sediment has been investigated. Obtained results suggest the possibility to describe these processes by exponential low and determination of the corresponding half lives. (author)

Calculation of secondary capacitance of compact Tesla pulse transformer

International Nuclear Information System (INIS)

Yu Binxiong; Liu Jinliang

2013-01-01

An analytic expression of the secondary capacitance of a compact Tesla pulse transformer is derived. Calculated result by the expression shows that two parts contribute to the secondary capacitance, namely the capacitance between inner and outer magnetic cores and the attached capacitance caused by the secondary winding. The attached capacitance equals to the capacitance of a coaxial line which is as long as the secondary coil, and whose outer and inner diameters are as large as the inner diameter of the outer magnetic and the outer diameter of the inner magnetic core respectively. A circuital model for analyzing compact Tesla transformer is built, and numeric calculation shows that the expression of the secondary capacitance is correct. Besides, a small compact Tesla transformer is developed, and related test is carried out. Test result confirms the calculated results by the expression derived. (authors)

Quantum capacitance of the armchair-edge graphene nanoribbon

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics; Volume 81; Issue 2. Quantum capacitance of the ... Abstract. The quantum capacitance, an important parameter in the design of nanoscale devices, is derived for armchair-edge single-layer graphene nanoribbon with semiconducting property. The quantum capacitance ...

Uptake and distribution of 137Cs, stable Cs and K in rice plants

International Nuclear Information System (INIS)

Tsukada, Hirofumi; Hasegawa, Hidenao

2003-01-01

The uptake and distributions of 137 Cs, stable Cs and K were determined for rice plant components, including polished rice, rice bran, hulls, leaves, stems, and roots. The distribution of 137 Cs in polished rice and rice bran was similar to that of stable Cs, while that of K was different. The concentration ratios of Cs/K in leaves increased in older leaf blade positions, which meant that the translocation rate of stable Cs, was slower than that of K. At harvest the dry weight of polished rice accounted for 34% of the entire rice plant, while the distributions of stable Cs in the polished rice and the non-edible parts were 7 and 93%, respectively. These findings suggest that the transfer and distribution of stable Cs in rice plants are different from those of K, and the behavior of stable Cs provides a useful analogue in predicting the fate of 137 Cs in an agricultural environment. (author)

Resistive and Capacitive Based Sensing Technologies

Directory of Open Access Journals (Sweden)

Winncy Y. Du

2008-04-01

Full Text Available Resistive and capacitive (RC sensors are the most commonly used sensors. Their applications span homeland security, industry, environment, space, traffic control, home automation, aviation, and medicine. More than 30% of modern sensors are direct or indirect applications of the RC sensing principles. This paper reviews resistive and capacitive sensing technologies. The physical principles of resistive sensors are governed by several important laws and phenomena such as Ohm’s Law, Wiedemann-Franz Law; Photoconductive-, Piezoresistive-, and Thermoresistive Effects. The applications of these principles are presented through a variety of examples including accelerometers, flame detectors, pressure/flow rate sensors, RTDs, hygristors, chemiresistors, and bio-impedance sensors. The capacitive sensors are described through their three configurations: parallel (flat, cylindrical (coaxial, and spherical (concentric. Each configuration is discussed with respect to its geometric structure, function, and application in various sensor designs. Capacitance sensor arrays are also presented in the paper.

A PARASITOLOGIC AND MOLECULAR SURVEY OF HEPATOZOON CANIS INFECTION IN STRAY DOGS IN NORTHEAST OF IRAN.

Science.gov (United States)

Barati, Ali; Razmi, Gholamreza

2018-05-15

Canine hepatozoonosis, caused by H. canis, is a tick-borne disease in domestic and wild dogs that is transmitted by ingestion of Rhipicephalus sanguineus ticks. The aim of the study was to detect H. canis in stray dogs in Iran using blood smear examination and molecular techniques. From October 2014 to September 2015, 150 EDTA blood samples were collected from stray dogs in the northeast region of Iran. Blood smears were microscopically examined for the presence of Hepatozoon gamonts; whole blood was evaluated by PCR, with subsequent sequencing and phylogenetic analysis. Hepatozoon spp. Gamonts were observed in the neutrophils of 5/150 (3.3%) blood smears, whereas Hepatozoon spp. 18S rDNA was detected in 12/150 (8.0%) blood samples from stray dogs. There was a good agreement between microscopy and PCR methods. (Kappa= 0.756). The highest rate of infection was seasonally detected in the summer (pHepatozoon spp infection was not significant by gender and age factors (p>0.05). The alignment analysis of the sequenced samples showed ≥99% similarity with other nucleotide sequences of Hepatozoon spp. in GenBank. The phylogenetic tree also revealed that the nucleotide sequences in this study were clustered in the H. canis clade and different from the H. felis and H. americanum clades. According to the results, it is concluded that H. canis infection is present among dogs in northeastern region of Iran.

Capacitance of carbon-based electrical double-layer capacitors.

Science.gov (United States)

Ji, Hengxing; Zhao, Xin; Qiao, Zhenhua; Jung, Jeil; Zhu, Yanwu; Lu, Yalin; Zhang, Li Li; MacDonald, Allan H; Ruoff, Rodney S

2014-01-01

Experimental electrical double-layer capacitances of porous carbon electrodes fall below ideal values, thus limiting the practical energy densities of carbon-based electrical double-layer capacitors. Here we investigate the origin of this behaviour by measuring the electrical double-layer capacitance in one to five-layer graphene. We find that the capacitances are suppressed near neutrality, and are anomalously enhanced for thicknesses below a few layers. We attribute the first effect to quantum capacitance effects near the point of zero charge, and the second to correlations between electrons in the graphene sheet and ions in the electrolyte. The large capacitance values imply gravimetric energy storage densities in the single-layer graphene limit that are comparable to those of batteries. We anticipate that these results shed light on developing new theoretical models in understanding the electrical double-layer capacitance of carbon electrodes, and on opening up new strategies for improving the energy density of carbon-based capacitors.

135Cs activity and 135Cs/137Cs atom ratio in environmental samples before and after the Fukushima Daiichi Nuclear Power Plant accident.

Science.gov (United States)

Yang, Guosheng; Tazoe, Hirofumi; Yamada, Masatoshi

2016-04-07

(135)Cs/(137)Cs is a potential tracer for radiocesium source identification. However, due to the challenge to measure (135)Cs, there were no (135)Cs data available for Japanese environmental samples before the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. It was only 3 years after the accident that limited (135)Cs values could be measured in heavily contaminated environmental samples. In the present study, activities of (134)Cs, (135)Cs, and (137)Cs, along with their ratios in 67 soil and plant samples heavily and lightly contaminated by the FDNPP accident were measured by combining γ spectrometry with ICP-MS/MS. The arithmetic means of the (134)Cs/(137)Cs activity ratio (1.033 ± 0.006) and (135)Cs/(137)Cs atom ratio (0.334 ± 0.005) (decay corrected to March 11, 2011), from old leaves of plants collected immediately after the FDNPP accident, were confirmed to represent the FDNPP derived radiocesium signature. Subsequently, for the first time, trace (135)Cs amounts before the FDNPP accident were deduced according to the contribution of global and FDNPP accident-derived fallout. Apart from two soil samples with a tiny global fallout contribution, contributions of global fallout radiocesium in other soil samples were observed to be 0.338%-52.6%. The obtained (135)Cs/(137)Cs database will be useful for its application as a geochemical tracer in the future.

Gastrointestinal Helminthic Parasites in Stray Cats (Felis catus from North of Iran

Directory of Open Access Journals (Sweden)

A Rezaei-Doust

2007-08-01

Full Text Available Background: Cats play a crucial role in the epidemiology of gastrointestinal helminthic parasites and also play a major role in transmitting of these parasites through faecal contamination of soil, food or water. The aim of this study was to determine the species of gastrointestinal helminthes parasites in stray cats from a rural area of Bandar-e-Anzali, Iran.Method: Gastrointestinal helminthes were collected from 50 necropsied stray cats (Felis catus after capturing them by trapping from different regions of the city and humanely euthanatized in Bandar-e-Anzali, a port in the Caspian Sea in northern Iran, from March to November 2003. Results: The prevalence of infection was 90%, with those of individual parasites being Diplopylidium nolleri 54%, Phy­saloptera praeputialis 32%, Ancylostoma tubaeforme 20%, Joyeuxiella pasqualei 10%, Toxocara cati 8%, Pterygoderma­tites affinis 6%, Ancylostoma caninum 4%, and Taenia taeniaeformis 2%. Concurrent infections with two or more parasites were recorded in 34% of the individuals. In relation to the sex, the differences were not significant. Conclusion: P. praeputialis, T. cati, D. nolleri and sometime J. pasqualei are the commonest Helminthes in cats. This is the first reported isolation of P. affinis and A. caninum infections from cats in Iran.

Novel RF-MEMS capacitive switching structures

NARCIS (Netherlands)

Rottenberg, X.; Jansen, Henricus V.; Fiorini, P.; De Raedt, W.; Tilmans, H.A.C.

2002-01-01

This paper reports on novel RF-MEMS capacitive switching devices implementing an electrically floating metal layer covering the dielectric to ensure intimate contact with the bridge in the down state. This results in an optimal switch down capacitance and allows optimisation of the down/up

The Pyramidal Capacitated Vehicle Routing Problem

DEFF Research Database (Denmark)

Lysgaard, Jens

This paper introduces the Pyramidal Capacitated Vehicle Routing Problem (PCVRP) as a restricted version of the Capacitated Vehicle Routing Problem (CVRP). In the PCVRP each route is required to be pyramidal in a sense generalized from the Pyramidal Traveling Salesman Problem (PTSP). A pyramidal...

The pyramidal capacitated vehicle routing problem

DEFF Research Database (Denmark)

Lysgaard, Jens

2010-01-01

This paper introduces the pyramidal capacitated vehicle routing problem (PCVRP) as a restricted version of the capacitated vehicle routing problem (CVRP). In the PCVRP each route is required to be pyramidal in a sense generalized from the pyramidal traveling salesman problem (PTSP). A pyramidal...

Activity standardization of 134Cs and 137Cs

International Nuclear Information System (INIS)

Sochorová, Jana; Auerbach, Pavel

2014-01-01

The paper presents the results from a primary standardization of 137 Cs using two independent methods – efficiency tracing using PC-NaI coincidence and the TDCR method. The nuclides 60 Co and 134 Cs were used as the tracers. Primary standardization of the 134 Cs is also discussed. The efficiency extrapolation was carried out by measuring samples of varying mass and using the wet extrapolation method. The results obtained are in good agreement; the differences did not exceed 0.5%. The advantages, pitfalls and also possibilities for improvement of the procedures are discussed

Determination of Cs-134 and Cs-137 rain water samples

International Nuclear Information System (INIS)

Lima, M.F.; Mazzilli, B.

1988-01-01

In order to setting an environmental monitoring program at IPEN, was developed a fast and simple methodology for concentration of Cs-134 and Cs-137 in rain water. This procedure consists in the precipitation of cesium and others cathions of its family (NH 4 + , K + and Rb + ) by ammonium molybdophosphate. The measures of the desintegration rates of Cs-134 and Cs-137 was done by gamma spectrometry in a Ge(Li) detector. After setting up the ideal experimental conditions, the procedure was used to analyze four samples of rain water. (author) [pt

Comment on "Density functional theory is straying from the path toward the exact functional"

DEFF Research Database (Denmark)

Kepp, Kasper Planeta

2017-01-01

Medvedev et al (Reports, 6 January 2017, p. 49) argue that recent density functionals stray from the path toward exactness. This conclusion rests on very compact 1s2 and 1s22s2 systems favored by the Hartree-Fock picture. Comparison to actual energies for the same systems indicates that the "stra...

Scanning Capacitance Microscopy | Materials Science | NREL

Science.gov (United States)

obtained using scanning capacitance microscopy. Top Right: Image of p-type and n-type material, obtained 'fingers' of light-colored n-type material on a yellow and blue background representing p-type material material, obtained using scanning capacitance microscopy, in a sample semiconductor device; the image shows

Determination of {sup 135}Cs and {sup 137}Cs in environmental samples: A review

Energy Technology Data Exchange (ETDEWEB)

Russell, B.C., E-mail: ben.russell@npl.co.uk [GAU-Radioanalytical, Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH (United Kingdom); National Physical Laboratory, Hampton Road, Teddington, Middlesex, TW11 0LW (United Kingdom); Croudace, Ian W.; Warwick, Phil E. [GAU-Radioanalytical, Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH (United Kingdom)

2015-08-26

Radionuclides of caesium are environmentally important since they are formed as significant high yield fission products ({sup 135}Cs and {sup 137}Cs) and activation products ({sup 134}Cs and {sup 136}Cs) during nuclear fission. They originate from a range of nuclear activities such as weapons testing, nuclear reprocessing and nuclear fuel cycle discharges and nuclear accidents. Whilst {sup 137}Cs, {sup 134}Cs and {sup 136}Cs are routinely measurable at high sensitivity by gamma spectrometry, routine detection of long-lived {sup 135}Cs by radiometric methods is challenging. This measurement is, however, important given its significance in long-term nuclear waste storage and disposal. Furthermore, the {sup 135}Cs/{sup 137}Cs ratio varies with reactor, weapon and fuel type, and accurate measurement of this ratio can therefore be used as a forensic tool in identifying the source(s) of nuclear contamination. The shorter-lived activation products {sup 134}Cs and {sup 136}Cs have a limited application but provide useful early information on fuel irradiation history and have importance in health physics. Detection of {sup 135}Cs (and {sup 137}Cs) is achievable by mass spectrometric techniques; most commonly inductively coupled plasma mass spectrometry (ICP-MS), as well as thermal ionisation (TIMS), accelerator (AMS) and resonance ionisation (RIMS) techniques. The critical issues affecting the accuracy and detection limits achievable by this technique are effective removal of barium to eliminate isobaric interferences arising from {sup 135}Ba and {sup 137}Ba, and elimination of peak tailing of stable {sup 133}Cs on {sup 135}Cs. Isobaric interferences can be removed by chemical separation, most commonly ion exchange chromatography, and/or instrumental separation using an ICP-MS equipped with a reaction cell. The removal of the peak tailing interference is dependent on the instrument used for final measurement. This review summarizes and compares the analytical procedures

Capacitance densitometer for flow regime identification

International Nuclear Information System (INIS)

Shipp, R.L. Jr.

1978-01-01

This invention relates to a capacitance densitometer for determining the flow regime of a two-phase flow system. A two-element capacitance densitometer is used in conjunction with a conventional single-beam gamma densitometer to unambiguously identify the prevailing flow regime and the average density of a flowing fluid

Voltage Dependence of Supercapacitor Capacitance

Directory of Open Access Journals (Sweden)

Szewczyk Arkadiusz

2016-09-01

Full Text Available Electronic Double-Layer Capacitors (EDLC, called Supercapacitors (SC, are electronic devices that are capable to store a relatively high amount of energy in a small volume comparing to other types of capacitors. They are composed of an activated carbon layer and electrolyte solution. The charge is stored on electrodes, forming the Helmholtz layer, and in electrolyte. The capacitance of supercapacitor is voltage- dependent. We propose an experimental method, based on monitoring of charging and discharging a supercapacitor, which enables to evaluate the charge in an SC structure as well as the Capacitance-Voltage (C-V dependence. The measurement setup, method and experimental results of charging/discharging commercially available supercapacitors in various voltage and current conditions are presented. The total charge stored in an SC structure is proportional to the square of voltage at SC electrodes while the charge on electrodes increases linearly with the voltage on SC electrodes. The Helmholtz capacitance increases linearly with the voltage bias while a sublinear increase of total capacitance was found. The voltage on SC increases after the discharge of electrodes due to diffusion of charges from the electrolyte to the electrodes. We have found that the recovery voltage value is linearly proportional to the initial bias voltage value.

Barged/In-river steelhead migrant data - Evaluation of methods to reduce straying rates of barged juvenile steelhead

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The goals of this study are to develop methods to reduce wandering and straying of steelhead (Oncorhynchus mykiss) that are collected and barged from the Snake River...

Laboratory data on Snake River steelhead - Evaluation of methods to reduce straying rates of barged juvenile steelhead

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The goals of this study are to develop methods to reduce wandering and straying of steelhead (Oncorhynchus mykiss) that are collected and barged from the Snake River...

A survey study on gastrointestinal parasites of stray cats in northern region of Nile delta, Egypt.

Directory of Open Access Journals (Sweden)

Reda E Khalafalla

Full Text Available A survey study on gastrointestinal parasites in 113 faecal samples from stray cats collected randomly from Kafrelsheikh province, northern region of Nile delta of Egypt; was conducted in the period between January and May 2010. The overall prevalence was 91%. The results of this study reported seven helminth species: Toxocara cati (9%, Ancylostoma tubaeforme (4%, Toxascaris leonina (5%, Dipylidium caninum (5%, Capillaria spp. (3%, Taenia taeniformis (22% and Heterophyes heterophyes (3%, four protozoal species: Toxoplasma gondii (9%, Sarcocyst spp. (1%, Isospora spp. (2% and Giardia spp. (2% and two arthropod species; Linguatula serrata (2% and mites eggs (13%. The overall prevalence of intestinal parasites may continue to rise due to lack of functional veterinary clinics for cat care in Egypt. Therefore, there is a need to plan adequate control programs to diagnose, treat and control gastrointestinal parasites of companion as well as stray cats in the region.

A Survey Study on Gastrointestinal Parasites of Stray Cats in Northern Region of Nile Delta, Egypt

Science.gov (United States)

Khalafalla, Reda E.

2011-01-01

A survey study on gastrointestinal parasites in 113 faecal samples from stray cats collected randomly from Kafrelsheikh province, northern region of Nile delta of Egypt; was conducted in the period between January and May 2010. The overall prevalence was 91%. The results of this study reported seven helminth species: Toxocara cati (9%), Ancylostoma tubaeforme (4%), Toxascaris leonina (5%), Dipylidium caninum (5%), Capillaria spp. (3%), Taenia taeniformis (22%) and Heterophyes heterophyes (3%), four protozoal species: Toxoplasma gondii (9%), Sarcocyst spp. (1%), Isospora spp. (2%) and Giardia spp. (2%) and two arthropod species; Linguatula serrata (2%) and mites eggs (13%). The overall prevalence of intestinal parasites may continue to rise due to lack of functional veterinary clinics for cat care in Egypt. Therefore, there is a need to plan adequate control programs to diagnose, treat and control gastrointestinal parasites of companion as well as stray cats in the region. PMID:21760884

Helminth Infections of Stray Dogs from Garmsar, Semnan Province, Central Iran

Directory of Open Access Journals (Sweden)

A Eslami

2010-12-01

Full Text Available Background: The aim was to study the gastro-intestinal helminths of stray dogs of Garmsar, Sem­nan Province, Central Iran, and its impacts on human health and animal production.Methods: During 2006, the alimentary tracts of 50 stray dogs at necropsy, selected from villages around Garmsar, were removed, and examined for helminth infections. Subsequently helminths were collected from the contents of each part and scraped sample of small intestines of washed materials in a 100-mesh sieve. To identify the species of helminths, the nematodes were cleared in lactophenol and cestodes were stained using carmine acid.Results: Mixed infection was the rule and 40 dogs (80% harbored more than one species of helminth. Taenia hydatigena was the most prevalent species (80% followed by Echinococcus granulosus (64%, Toxocara canis (22%, Mesocestoides lineatus (12%, Taenia multiceps (10% and Dipylidium caninum (4%. The mean intensity of worm infection was low (1-3 ex­cept for that of E. granulosus (645. No significant difference was noticed between sex, age and most helminth infections except for that of sex and T. hydatigena (P=0.001 as well as age and T. canis (P=0.001.Conclusion: Although human infection with T. hydatigena is unlikely, but other helminths re­ported in this study are of zoonotic importance, and may pose a threat to community health, and reduce the productions of ruminants harboring taeniid metacestodes.

Highly Compressible Carbon Sponge Supercapacitor Electrode with Enhanced Performance by Growing Nickel-Cobalt Sulfide Nanosheets.

Science.gov (United States)

Liang, Xu; Nie, Kaiwen; Ding, Xian; Dang, Liqin; Sun, Jie; Shi, Feng; Xu, Hua; Jiang, Ruibin; He, Xuexia; Liu, Zonghuai; Lei, Zhibin

2018-03-28

The development of compressible supercapacitor highly relies on the innovative design of electrode materials with both superior compression property and high capacitive performance. This work reports a highly compressible supercapacitor electrode which is prepared by growing electroactive NiCo 2 S 4 (NCS) nanosheets on the compressible carbon sponge (CS). The strong adhesion of the metallic conductive NCS nanosheets to the highly porous carbon scaffolds enable the CS-NCS composite electrode to exhibit an enhanced conductivity and ideal structural integrity during repeated compression-release cycles. Accordingly, the CS-NCS composite electrode delivers a specific capacitance of 1093 F g -1 at 0.5 A g -1 and remarkable rate performance with 91% capacitance retention in the range of 0.5-20 A g -1 . Capacitance performance under the strain of 60% shows that the incorporation of NCS nanosheets in CS scaffolds leads to over five times enhancement in gravimetric capacitance and 17 times enhancement in volumetric capacitance. These performances enable the CS-NCS composite to be one of the promising candidates for potential applications in compressible electrochemical energy storage devices.

Ferroelectric Negative Capacitance Domain Dynamics

OpenAIRE

Hoffmann, Michael; Khan, Asif Islam; Serrao, Claudy; Lu, Zhongyuan; Salahuddin, Sayeef; Pešić, Milan; Slesazeck, Stefan; Schroeder, Uwe; Mikolajick, Thomas

2017-01-01

Transient negative capacitance effects in epitaxial ferroelectric Pb(Zr$_{0.2}$Ti$_{0.8}$)O$_3$ capacitors are investigated with a focus on the dynamical switching behavior governed by domain nucleation and growth. Voltage pulses are applied to a series connection of the ferroelectric capacitor and a resistor to directly measure the ferroelectric negative capacitance during switching. A time-dependent Ginzburg-Landau approach is used to investigate the underlying domain dynamics. The transien...

Distribution of coronary arterial capacitance in a canine model.

Science.gov (United States)

Lader, A S; Smith, R S; Phillips, G C; McNamee, J E; Abel, F L

1998-03-01

The capacitative properties of the major left coronary arteries, left main (LM), left anterior descending (LAD), and left circumflex (LCX), were studied in 19 open-chest isolated dog hearts. Capacitance was determined by using ramp perfusion and a left ventricular-to-coronary shunt diastolic decay method; both methods gave similar results, indicating a minimal systolic capacitative component. Increased pericardial pressure (PCP), 25 mmHg, was used to experimentally alter transmural wall pressure. The response to increased PCP was different in the LAD vs. LCX; increasing PCP decreased capacitance in the LCX but increased capacitance in the LAD. This may have been due to the different intramural vs. epicardial volume distribution of these vessels and a decrease in intramural tension during increased PCP. Increased PCP decreased LCX capacitance by approximately 13%, but no changes in conductance or zero flow pressure intercept occurred in any of the three vessels, i. e., evidence against the waterfall theory of vascular collapse at these levels of PCP. Coronary arterial capacitance was also linearly related to perfusion pressure.

A Preliminary Study on the Helminth Fauna in Necropsied Stray Cats (Felis catus in Beni-Suef, Egypt

Directory of Open Access Journals (Sweden)

Khaled Mohamed El-Dakhly

2017-10-01

Full Text Available Stray cats play a crucial role in the epidemiology of endoparasites, particularly helminths, due to predating a wide range of both vertebrate and invertebrate hosts, often of veterinary and zoonotic importance. Therefore, a total of 62 stray cats were necropsied in Beni-Suef province, Egypt and examined for helminth parasites. The overall prevalence of infection was 87.0%. The recovered helminths consisted of 10 species of trematodes (Heterophyes heterophyes, Pygidiopsis summa, H. nocens, Echinochasmus liliputanus, Alaria sp., Procerovum varium, Ascocotyle sp., Haplorchis sp., Prohemistomum vivax, Euparadistomum herpestesi, five cestodes (Dipylidium caninum, Diplopylidium acanthoterta, D. nolleri, Joyeuxiella sp. and Taenia taeniaeformis, and two nematodes (Toxascaris leonina and larvae of Anisakis simplex. The most prevalent helminths were Dipylidium caninum (62.9%, Toxascaris leonina (33.8%, Diplopylidium nolleri (22.5% and Echinochasmus liliputanus (6.45%. Thirty (48.39% cats were co-infected by one species, 22 (35.48% by two and three (4.84% by more than two species. It has been found that cats aged more than 3 years were the most infected. Both male and female cats were parasitized. The infection was the most prevalent in both summer and autumn. In conclusion, veterinarians must highlight more attention towards both stray and domestic cats, as they are considered reservoir hosts for a wide host range of parasites, particularly helminths, and the zoonotic importance of such parasites should be taken on consideration.

Solar Cell Capacitance Determination Based on an RLC Resonant Circuit

Directory of Open Access Journals (Sweden)

Petru Adrian Cotfas

2018-03-01

Full Text Available The capacitance is one of the key dynamic parameters of solar cells, which can provide essential information regarding the quality and health state of the cell. However, the measurement of this parameter is not a trivial task, as it typically requires high accuracy instruments using, e.g., electrical impedance spectroscopy (IS. This paper introduces a simple and effective method to determine the electric capacitance of the solar cells. An RLC (Resistor Inductance Capacitor circuit is formed by using an inductor as a load for the solar cell. The capacitance of the solar cell is found by measuring the frequency of the damped oscillation that occurs at the moment of connecting the inductor to the solar cell. The study is performed through simulation based on National Instruments (NI Multisim application as SPICE simulation software and through experimental capacitance measurements of a monocrystalline silicon commercial solar cell and a photovoltaic panel using the proposed method. The results were validated using impedance spectroscopy. The differences between the capacitance values obtained by the two methods are of 1% for the solar cells and of 9.6% for the PV panel. The irradiance level effect upon the solar cell capacitance was studied obtaining an increase in the capacitance in function of the irradiance. By connecting different inductors to the solar cell, the frequency effect upon the solar cell capacitance was studied noticing a very small decrease in the capacitance with the frequency. Additionally, the temperature effect over the solar cell capacitance was studied achieving an increase in capacitance with temperature.

Electrosorption capacitance of nanostructured carbon-based materials.

Science.gov (United States)

Hou, Chia-Hung; Liang, Chengdu; Yiacoumi, Sotira; Dai, Sheng; Tsouris, Costas

2006-10-01

The fundamental mechanism of electrosorption of ions developing a double layer inside nanopores was studied via a combination of experimental and theoretical studies. A novel graphitized-carbon monolithic material has proven to be a good electrical double-layer capacitor that can be applied in the separation of ions from aqueous solutions. An extended electrical double-layer model indicated that the pore size distribution plays a key role in determining the double-layer capacitance in an electrosorption process. Because of the occurrence of double-layer overlapping in narrow pores, mesopores and micropores make significantly different contributions to the double-layer capacitance. Mesopores show good electrochemical accessibility. Micropores present a slow mass transfer of ions and a considerable loss of double-layer capacitance, associated with a shallow potential distribution inside pores. The formation of the diffuse layer inside the micropores determines the magnitude of the double-layer capacitance at low electrolyte concentrations and at conditions close to the point of zero charge of the material. The effect of the double-layer overlapping on the electrosorption capacitance can be reduced by increasing the pore size, electrolyte concentration, and applied potential. The results are relevant to water deionization.

A 45.8fJ/Step, energy-efficient, differential SAR capacitance-to-digital converter for capacitive pressure sensing

KAUST Repository

Alhoshany, Abdulaziz

2016-05-03

An energy-efficient readout circuit for a capacitive sensor is presented. The capacitive sensor is digitized by a 12-bit energy efficient capacitance-to-digital converter (CDC) that is based on a differential successive-approximation architecture. This CDC meets extremely low power requirements by using an operational transconductance amplifier (OTA) that is based on a current-starved inverter. It uses a charge-redistribution DAC that involves coarse-fine architecture. We split the DAC into a coarse-DAC and a fine-DAC to allow a wide capacitance range in a compact area. It covers a wide range of capacitance of 16.14 pF with a 4.5 fF absolute resolution. An analog comparator is implemented by cross-coupling two 3-input NAND gates to enable power and area efficient operation. The prototype CDC was fabricated using a standard 180 nm CMOS technology. The 12-bit CDC has a measurement time of 42.5 μs, and consumes 3.54 μW and 0.29 μW from analog and digital supplies, respectively. This corresponds to a state-of-the-art figure-of-merit (FoM) of 45.8 fJ/conversion-step. © 2016 Elsevier B.V. All rights reserved.

A 45.8fJ/Step, energy-efficient, differential SAR capacitance-to-digital converter for capacitive pressure sensing

KAUST Repository

Alhoshany, Abdulaziz; Omran, Hesham; Salama, Khaled N.

2016-01-01

An energy-efficient readout circuit for a capacitive sensor is presented. The capacitive sensor is digitized by a 12-bit energy efficient capacitance-to-digital converter (CDC) that is based on a differential successive-approximation architecture. This CDC meets extremely low power requirements by using an operational transconductance amplifier (OTA) that is based on a current-starved inverter. It uses a charge-redistribution DAC that involves coarse-fine architecture. We split the DAC into a coarse-DAC and a fine-DAC to allow a wide capacitance range in a compact area. It covers a wide range of capacitance of 16.14 pF with a 4.5 fF absolute resolution. An analog comparator is implemented by cross-coupling two 3-input NAND gates to enable power and area efficient operation. The prototype CDC was fabricated using a standard 180 nm CMOS technology. The 12-bit CDC has a measurement time of 42.5 μs, and consumes 3.54 μW and 0.29 μW from analog and digital supplies, respectively. This corresponds to a state-of-the-art figure-of-merit (FoM) of 45.8 fJ/conversion-step. © 2016 Elsevier B.V. All rights reserved.

Improving CS regulations.

Energy Technology Data Exchange (ETDEWEB)

Nesse, R.J.; Scheer, R.M.; Marasco, A.L.; Furey, R.

1980-10-01

President Carter issued Executive Order 12044 (3/28/78) that required all Federal agencies to distinguish between significant and insignificant regulations, and to determine whether a regulation will result in major impacts. This study gathered information on the impact of the order and the guidelines on the Office of Conservation and Solar Energy (CS) regulatory practices, investigated problems encountered by the CS staff when implementing the order and guidelines, and recommended solutions to resolve these problems. Major tasks accomplished and discussed are: (1) legislation, Executive Orders, and DOE Memoranda concerning Federal administrative procedures relevant to the development and analysis of regulations within CS reviewed; (2) relevant DOE Orders and Memoranda analyzed and key DOE and CS staff interviewed in order to accurately describe the current CS regulatory process; (3) DOE staff from the Office of the General Counsel, the Office of Policy and Evaluation, the Office of the Environment, and the Office of the Secretary interviewed to explore issues and problems encountered with current CS regulatory practices; (4) the regulatory processes at five other Federal agencies reviewed in order to see how other agencies have approached the regulatory process, dealt with specific regulatory problems, and responded to the Executive Order; and (5) based on the results of the preceding four tasks, recommendations for potential solutions to the CS regulatory problems developed. (MCW)

Bidirectional reflectance distribution function /BRDF/ measurements of stray light suppression coatings for the Space Telescope /ST/

Science.gov (United States)

Griner, D. B.

1979-01-01

The paper considers the bidirectional reflectance distribution function (BRDF) of black coatings used on stray light suppression systems for the Space Telescope (ST). The ST stray light suppression requirement is to reduce earth, moon, and sun light in the focal plane to a level equivalent to one 23 Mv star per square arcsecond, an attenuation of 14 orders of magnitude. It is impractical to verify the performance of a proposed baffle system design by full scale tests because of the large size of the ST, so that a computer analysis is used to select the design. Accurate computer analysis requires a knowledge of the diffuse scatter at all angles from the surface of the coatings, for all angles of incident light. During the early phases of the ST program a BRDF scanner was built at the Marshall Space Flight Center to study the scatter from black materials; the measurement system is described and the results of measurements on samples proposed for use on the ST are presented.

Some aspects of stray losses in large power transformers

International Nuclear Information System (INIS)

Valkovic, Zvonimir

2002-01-01

The paper presents some results of the investigation of stray losses in power transformers that are caused by high-current loops. The investigation was focused on: a) additional losses in tank cover around high-current bushings and the way of their reduction, b) extra leakage flux and additional losses due to high current delta-connections. The insertion of nonmagnetic gaps between the phase bushings reduces the extra cover losses more than three times. A nonmagnetic plate around the high-current bushings reduces these extra losses practically to zero. The extra losses due to the high-current delta-connections could be significant for the transformer loss level. These extra losses could be controlled (reduced) by the design layout of the delta-connections. (Author)

Design of double capacitances infrasonic receiver

International Nuclear Information System (INIS)

Wang Changhai; Han Kuixia; Wang Fei

2003-01-01

The article introduces the theory of infrasonic generation and reception of nuclear explosion. An idea of the design of double capacitances infrasonic receiver using CPLD technology is given in it. Compare with the single capacitance infrasonic receiver, sensitivity of the improved receiver can be improved scores of times, dynamic range can be improved largely, and the whole performance gets improvement a lots

Radiation damage in undoped CsI and CsI(Tl)

International Nuclear Information System (INIS)

Woody, C.L.; Kierstead, J.A.; Levy, P.W.; Stoll, S.

1992-01-01

Radiation damage has been studied in undoped CsI and CsI(TI) crystals using 60 Co gamma radiation for doses up to ∼ 4.2 x 10 6 . Samples from various manufacturers were measured ranging in size from 2.54 cm long cylinders to a 30 cm long block. Measurements were made on the change in optical transmission and scintillation light output as a function of dose. Although some samples showed a small change in transmission, a significant change in light output was observed for all samples. Recovery from damage was also studied as a function of time and exposure to UV light. A short lived phosphorescence was observed in undoped CsI, similar to the phosphorescence seen in CsI(TI)

Interdigitated electrodes as impedance and capacitance biosensors: A review

Science.gov (United States)

Mazlan, N. S.; Ramli, M. M.; Abdullah, M. M. A. B.; Halin, D. S. C.; Isa, S. S. M.; Talip, L. F. A.; Danial, N. S.; Murad, S. A. Z.

2017-09-01

Interdigitated electrodes (IDEs) are made of two individually addressable interdigitated comb-like electrode structures. IDEs are one of the most favored transducers, widely utilized in technological applications especially in the field of biological and chemical sensors due to their inexpensive, ease of fabrication process and high sensitivity. In order to detect and analyze a biochemical molecule or analyte, the impedance and capacitance signal need to be obtained. This paper investigates the working principle and influencer of the impedance and capacitance biosensors. The impedance biosensor depends on the resistance and capacitance while the capacitance biosensor influenced by the dielectric permittivity. However, the geometry and structures of the interdigitated electrodes affect both impedance and capacitance biosensor. The details have been discussed in this paper.

Effects of stray lights on Faraday rotation measurement for polarimeter-interferometer system on EAST.

Science.gov (United States)

Zou, Z Y; Liu, H Q; Ding, W X; Chen, J; Brower, D L; Lian, H; Wang, S X; Li, W M; Yao, Y; Zeng, L; Jie, Y X

2018-01-01

A double-pass radially view 11 chords polarimeter-interferometer system has been operated on the experimental advanced superconducting tokamak and provides important current profile information for plasma control. Stray light originating from spurious reflections along the optical path (unwanted reflections from various optical components/mounts and transmissive optical elements such as windows, waveplates, and lens as well as the detectors) and also direct feedback from the retro-reflector used to realize the double-pass configuration can both contribute to contamination of the Faraday rotation measurement accuracy. Modulation of the Faraday rotation signal due to the interference from multiple reflections is observable when the interferometer phase (plasma density) varies with time. Direct reflection from the detector itself can be suppressed by employing an optical isolator consisting of a λ/4-waveplate and polarizer positioned in front of the mixer. A Faraday angle oscillation during the density ramping up (or down) can be reduced from 5°-10° to 1°-2° by eliminating reflections from the detector. Residual modulation arising from misalignment and stray light from other sources must be minimized to achieve accurate measurements of Faraday rotation.

Regeneration of Used Frying Palm Oil with Coffee Silverskin (CS), CS Ash (CSA) and Nanoparticles of CS (NCS).

Science.gov (United States)

Ismail, Samir Abd-Elmonem A; El-Anany, Ayman Mohammed; Ali, Rehab Farouk M

2017-01-01

The present investigation aimed to evaluate the efficiency of coffee silverskin (CS), CS ash (CSA) and nanoparticles of CS (NCS) in regeneration the quality of used frying palm oil. The adsorbents were mixed individually with used frying palm oil at level 4% (w/v) for 60 min. The properties of CS, CSA and NCS adsorbents were studied using (SEM) scanning electron microscopy technique. Some of physico-chemical characteristics of used frying palm oil (UFPO) and UFPO treated with adsorbents were determined. The results showed that the CS ash particles composed of irregular spherical and semispherical grains with deep cavities. The size of particles of CS ash ranged in diameter from 1.1 to 1.7 µm. The morphology of NCS consisted of cluster-type spherical nanoparticles and flakes. The particle size of NCS varies from 0.9 to 1.7 µm. Purification treatments caused marked (poil compared to untreated oil. The treatment of UFPO with 4% of adsorbents caused significant reductions in the content of free fatty acids ranged from 51.2 to 65.0%. The lowest level of peroxide (2.1 meq/kg) was recorded for UFPO treated with 4% of NCS. The highest reductions (72.8; 70.0%) in p-anisidine value were observed in UFPO treated with 4% of CSA and NCS, respectively. Treatment of UFPO with 4% of CS, CSA and NCS significantly lowered the polar content from 13.9% to 6.3, 4.8 and 3.9%, respectively. The results also indicate that CSA and NCS have nearly the same adsorption efficiency in lowering polymer content of UFPO. Filtration treatment of UFPO with 4% of CS, CSA and NCS markedly lowered the viscosity and colour values of treated UFPO.

Multi-Channel Capacitive Sensor Arrays

Directory of Open Access Journals (Sweden)

Bingnan Wang

2016-01-01

Full Text Available In this paper, multi-channel capacitive sensor arrays based on microstrip band-stop filters are studied. The sensor arrays can be used to detect the proximity of objects at different positions and directions. Each capacitive sensing structure in the array is connected to an inductive element to form resonance at different frequencies. The resonances are designed to be isolated in the frequency spectrum, such that the change in one channel does not affect resonances at other channels. The inductive element associated with each capacitive sensor can be surface-mounted inductors, integrated microstrip inductors or metamaterial-inspired structures. We show that by using metamaterial split-ring structures coupled to a microstrip line, the quality factor of each resonance can be greatly improved compared to conventional surface-mounted or microstrip meander inductors. With such a microstrip-coupled split-ring design, more sensing elements can be integrated in the same frequency spectrum, and the sensitivity can be greatly improved.

Bioenergetics of mammalian sperm capacitation.

Science.gov (United States)

Ferramosca, Alessandra; Zara, Vincenzo

2014-01-01

After ejaculation, the mammalian male gamete must undergo the capacitation process, which is a prerequisite for egg fertilization. The bioenergetics of sperm capacitation is poorly understood despite its fundamental role in sustaining the biochemical and molecular events occurring during gamete activation. Glycolysis and mitochondrial oxidative phosphorylation (OXPHOS) are the two major metabolic pathways producing ATP which is the primary source of energy for spermatozoa. Since recent data suggest that spermatozoa have the ability to use different metabolic substrates, the main aim of this work is to present a broad overview of the current knowledge on the energy-producing metabolic pathways operating inside sperm mitochondria during capacitation in different mammalian species. Metabolism of glucose and of other energetic substrates, such as pyruvate, lactate, and citrate, is critically analyzed. Such knowledge, besides its obvious importance for basic science, could eventually translate into the development of novel strategies for treatment of male infertility, artificial reproduction, and sperm selection methods.

A robust parasitic-insensitive successive approximation capacitance-to-digital converter

KAUST Repository

Omran, Hesham

2014-09-01

In this paper, we present a capacitive sensor digital interface circuit using true capacitance-domain successive approximation that is independent of supply voltage. Robust operation is achieved by using a charge amplifier stage and multiple comparison technique. The interface circuit is insensitive to parasitic capacitances, offset voltages, and charge injection, and is not prone to noise coupling. The proposed design achieves very low temperature sensitivity of 25ppm/oC. A coarse-fine programmable capacitance array allows digitizing a wide capacitance range of 16pF with 12.5-bit quantization limited resolution in a compact area of 0.07mm2. The fabricated prototype is experimentally verified using on-chip sensor and off-chip MEMS capacitive pressure sensor. © 2014 IEEE.

A robust parasitic-insensitive successive approximation capacitance-to-digital converter

KAUST Repository

Omran, Hesham; Arsalan, Muhammad; Salama, Khaled N.

2014-01-01

In this paper, we present a capacitive sensor digital interface circuit using true capacitance-domain successive approximation that is independent of supply voltage. Robust operation is achieved by using a charge amplifier stage and multiple comparison technique. The interface circuit is insensitive to parasitic capacitances, offset voltages, and charge injection, and is not prone to noise coupling. The proposed design achieves very low temperature sensitivity of 25ppm/oC. A coarse-fine programmable capacitance array allows digitizing a wide capacitance range of 16pF with 12.5-bit quantization limited resolution in a compact area of 0.07mm2. The fabricated prototype is experimentally verified using on-chip sensor and off-chip MEMS capacitive pressure sensor. © 2014 IEEE.

A reciprocity-based formula for the capacitance with quadrupolar electrodes

Energy Technology Data Exchange (ETDEWEB)

Cho, Sungbo [Gachon University of Medicine and Science, Incheon (Korea, Republic of)

2011-11-15

A new capacitance formula for the practical design and characterization of quadrupolar electrode arrays with capacitive structures was derived based on the reciprocal theorem. The reciprocity-based capacitance formula agreed with the empirical equations established to estimate the capacitance of a single strip line or disk electrode compensating for the fringing field effect that occurs at the electrode edge. The reciprocity-based formula was applied to compute the capacitance measurable by using a quadrupolar square electrode array with a symmetric dipole-dipole configuration and was compared with the analytical equation established based on the image method assuming that the electrodes were points. The results showed that the capacitance of the quadrupolar electrodes was determined by the size of the quadrupolar electrodes relative to the separation distance between the electrodes and that the reciprocity-based capacitance formula was in agreement with the established analytical equation if the separated distance between the electrodes relative to the electrode size was large enough.

A reciprocity-based formula for the capacitance with quadrupolar electrodes

International Nuclear Information System (INIS)

Cho, Sungbo

2011-01-01

A new capacitance formula for the practical design and characterization of quadrupolar electrode arrays with capacitive structures was derived based on the reciprocal theorem. The reciprocity-based capacitance formula agreed with the empirical equations established to estimate the capacitance of a single strip line or disk electrode compensating for the fringing field effect that occurs at the electrode edge. The reciprocity-based formula was applied to compute the capacitance measurable by using a quadrupolar square electrode array with a symmetric dipole-dipole configuration and was compared with the analytical equation established based on the image method assuming that the electrodes were points. The results showed that the capacitance of the quadrupolar electrodes was determined by the size of the quadrupolar electrodes relative to the separation distance between the electrodes and that the reciprocity-based capacitance formula was in agreement with the established analytical equation if the separated distance between the electrodes relative to the electrode size was large enough.

Properties of CsI and CsI-TMAE photocathodes

International Nuclear Information System (INIS)

Anderson, D.F.; Kwan, S.; Peskov, V.; Hoeneisen, B.

1992-06-01

The importance of heating the CsI or CsI-TMAE photocathodes during preparation, as well as the importance of the gas environment on the quantum efficiency is presented. The dependence of the aging characteristics of these photocathodes on the operating temperature, on the presence of gas, and on the charge amplification of the chamber is also discussed. For CsI photocathodes charges in excess of 2x10 14 e - /mm 2 can be collected with little degradation of performance. A timing resolution of 0.55 ns is also achieved for single photoelectrons suggesting a possible time-of-flight detector

Possibility of reducing stray losses and parasitic torques in two-phase emergency feeding of induction motors

Czech Academy of Sciences Publication Activity Database

Schreier, Luděk; Bendl, Jiří; Chomát, Miroslav; Klíma, J.

2006-01-01

Roč. 51, č. 2 (2006), s. 109-131 ISSN 0001-7043 R&D Projects: GA ČR(CZ) GA102/04/0215 Institutional research plan: CEZ:AV0Z20570509 Keywords : induction motor * emergency operation of electrical drives * stray losses Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

Measurement Error Estimation for Capacitive Voltage Transformer by Insulation Parameters

Directory of Open Access Journals (Sweden)

Bin Chen

2017-03-01

Full Text Available Measurement errors of a capacitive voltage transformer (CVT are relevant to its equivalent parameters for which its capacitive divider contributes the most. In daily operation, dielectric aging, moisture, dielectric breakdown, etc., it will exert mixing effects on a capacitive divider’s insulation characteristics, leading to fluctuation in equivalent parameters which result in the measurement error. This paper proposes an equivalent circuit model to represent a CVT which incorporates insulation characteristics of a capacitive divider. After software simulation and laboratory experiments, the relationship between measurement errors and insulation parameters is obtained. It indicates that variation of insulation parameters in a CVT will cause a reasonable measurement error. From field tests and calculation, equivalent capacitance mainly affects magnitude error, while dielectric loss mainly affects phase error. As capacitance changes 0.2%, magnitude error can reach −0.2%. As dielectric loss factor changes 0.2%, phase error can reach 5′. An increase of equivalent capacitance and dielectric loss factor in the high-voltage capacitor will cause a positive real power measurement error. An increase of equivalent capacitance and dielectric loss factor in the low-voltage capacitor will cause a negative real power measurement error.

Development trends of combined inductance-capacitance electromechanical energy converters

Directory of Open Access Journals (Sweden)

Karayan Hamlet

2018-01-01

Full Text Available In the article the modern state of completely new direction of electromechanical science such as combined inductive-capacitive electromechanics is considered. The wide spectra of its possible practical applications and prospects for further development are analyzed. A new approach for mathematical description of transients in dualcon jugate dynamic systems is proposed. On the basis of the algorithm differential equations for inductive-capacitive compatible electromechanical energy converters are derived. The generalized Lagrangian theory of combined inductively-capacitive electric machines was developed as a union of generalized Lagrangian models of inductive and capacitive electro-mechanical energy converters developed on the basis of the basic principles of binary-conjugate electrophysics. The author gives equations of electrodynamics and electromechanics of combined inductive-capacitive electric machines in case there are active electrotechnical materials of dual purpose (ferroelectromagnets in the structure of their excitation system. At the same time, the necessary Lagrangian for combined inductive-capacitive forces was built using new technologies of interaction between inductive and capacitive subsystems. The joint solution of these equations completely determines the dynamic behavior and energy characteristics of the generalized model of combined machines of any design and in any modes of interaction of their functional elements

Concentration of 134Cs and 137Cs in Malaysian palm products

International Nuclear Information System (INIS)

Yii Mei Wo; Nor Aza Hassan; Narizan Sanusi

2008-08-01

Until today, countries importing food products from Malaysia, in region such as Indian Continental, Middle East, Central Europe and Central America still require the products to be tested for the radioactive contamination particularly for 134 Cs and 137 Cs. Information extracted from 3371 analytical results observed on isotopic concentration for 134 Cs and 137 Cs in the exported Malaysia origins palm products between years 2002 until 2007 had been summarized and reported in this work. Data shown that the concentration level of the concerned radio nuclides are below the minimum detectable activity and also well below maximum permissible limits adopted by Malaysian Government and also the international bodies. (Author)

Magnetic charge distribution and stray field landscape of asymmetric néel walls in a magnetically patterned exchange bias layer system

Science.gov (United States)

Zingsem, Norbert; Ahrend, Florian; Vock, Silvia; Gottlob, Daniel; Krug, Ingo; Doganay, Hatice; Holzinger, Dennis; Neu, Volker; Ehresmann, Arno

2017-12-01

The 3D stray field landscape above an exchange bias layer system with engineered domain walls has been fully characterized by quantitative magnetic force microscopy (qMFM) measurements. This method is based on a complete quantification of the MFM tip’s imaging properties and the subtraction of its contribution from the measured MFM data by deconvolution in Fourier space. The magnetically patterned Ir17Mn83/Co70Fe30-exchange-bias-multilayers have been designed to contain asymmetric head-to-head (hh)/tail-to-tail (tt) Néel walls between domains of different magnetic anisotropies for potential use in guided particle transport. In the current application, qMFM reveals the effective magnetic charge profile on the surface of the sample—with high spatial resolution and in an absolute quantitative manner. These data enable to calculate the magnetostatic potential and the full stray field landscape above the sample surface. It has been successfully tested against: (i) micromagnetic simulations of the magnetization structure of a comparable exchange-bias layer system, (ii) measurements of the magnetization profile across the domain boundary with x-ray photoemission electron microscopy, and (iii) direct stray field measurements obtained by scanning Hall probe microscopy at elevated scan heights. This approach results in a quantitative determination of the stray field landscape at close distances to the sample surface, which will be of importance for remote magnetic particle transport applications in lab-on-a-chip devices. Furthermore, the highly resolving and quantitative MFM approach reveals details of the domain transition across the artificially structured phase boundary, which have to be attributed to a continuous change in the materials parameters across this boundary, rather than an abrupt one.

Separation of 134Cs and 137Cs from 125I solution for medical applications

International Nuclear Information System (INIS)

Ram, Ramu; Dash, Ashutosh; Banerjee, Dayamoy

2015-01-01

While neutron irradiation of natural Xe gas followed by wet chemical dissolution of activation products constitutes a successful paradigm for the small scale production 125 I, the concomitant production of 134 Cs and 137 Cs emerged as the primary impediment which necessitates purification of 125 I solution. This paper describes an ion-exchange chromatographic technique using Resorcinol Formaldehyde (RF) resin to purify 125 I solution from 134 Cs and 137 Cs impurities. A thorough investigation of the adsorption parameters of RF resin was carried out to arrive at the experimental conditions resulting optimum retention of 134 Cs and 137 Cs impurities. Based on the experimental findings, an optimized separation procedure was developed in which the neutron irradiated dissolved products at pH ∝ 13 was passed through a chromatography column containing RF resin where in 134 Cs and 137 Cs impurities gets adsorbed leaving behind 125 I to appear in the effluent. The overall recovery of 125 I was >90% with acceptable purity amenable for clinical applications.

Capacitance-Power-Hysteresis Trilemma in Nanoporous Supercapacitors

Directory of Open Access Journals (Sweden)

Alpha A. Lee

2016-06-01

Full Text Available Nanoporous supercapacitors are an important player in the field of energy storage that fill the gap between dielectric capacitors and batteries. The key challenge in the development of supercapacitors is the perceived trade-off between capacitance and power delivery. Current efforts to boost the capacitance of nanoporous supercapacitors focus on reducing the pore size so that they can only accommodate a single layer of ions. However, this tight packing compromises the charging dynamics and hence power density. We show via an analytical theory and Monte Carlo simulations that charging is sensitively dependent on the affinity of ions to the pores, and that high capacitances can be obtained for ionophobic pores of widths significantly larger than the ion diameter. Our theory also predicts that charging can be hysteretic with a significant energy loss per cycle for intermediate ionophilicities. We use these observations to explore the parameter regimes in which a capacitance-power-hysteresis trilemma may be avoided.

A capacitive ECG array with visual patient feedback.

Science.gov (United States)

Eilebrecht, Benjamin; Schommartz, Antje; Walter, Marian; Wartzek, Tobias; Czaplik, Michael; Leonhardt, Steffen

2010-01-01

Capacitive electrocardiogram (ECG) sensing is a promising technique for less constraining vital signal measurement and close to a commercial application. Even bigger trials testing the diagnostic significance were already done with single lead systems. Anyway, most applications to be found in research are limited to one channel and thus limited in its diagnostic relevance as only diseases coming along with a change of the heart rate can be diagnosed adequately. As a consequence the need for capacitive multi-channel ECGs combining the diagnostic relevance and the advantages of capacitive ECG sensing emerges. This paper introduces a capacitive ECG measurement system which allows the recording of standardized ECG leads according to Einthoven and Goldberger by means of an electrode array with nine electrodes.

Negative capacitance in a ferroelectric capacitor.

Science.gov (United States)

Khan, Asif Islam; Chatterjee, Korok; Wang, Brian; Drapcho, Steven; You, Long; Serrao, Claudy; Bakaul, Saidur Rahman; Ramesh, Ramamoorthy; Salahuddin, Sayeef

2015-02-01

The Boltzmann distribution of electrons poses a fundamental barrier to lowering energy dissipation in conventional electronics, often termed as Boltzmann Tyranny. Negative capacitance in ferroelectric materials, which stems from the stored energy of a phase transition, could provide a solution, but a direct measurement of negative capacitance has so far been elusive. Here, we report the observation of negative capacitance in a thin, epitaxial ferroelectric film. When a voltage pulse is applied, the voltage across the ferroelectric capacitor is found to be decreasing with time--in exactly the opposite direction to which voltage for a regular capacitor should change. Analysis of this 'inductance'-like behaviour from a capacitor presents an unprecedented insight into the intrinsic energy profile of the ferroelectric material and could pave the way for completely new applications.

[Energy pooling collisions for K(4P) + Cs(5D) in a K-Cs mixture].

Science.gov (United States)

Aihemaiti, Pulati; Dai, Kang; Lu, Xin-hong; Shen, Yi-fan

2005-04-01

The rate coefficients for energy-pooling collisions K(4P) + Cs(5D) --> Cs(6S) + K(4D, 6S) in the K-Cs vapor mixture were measured relative to a known energy-pooling rate coefficient of a homonuclear reaction [i. e., Cs(6P) + Cs(5D) --> Cs(6S) + Cs (7D(J))]. Populations of the Cs(6P, 5D) and K(4P) states were produced by photodissociation of K2 and Cs2 molecules through the use of a dye laser radiation. The resulting fluorescence included the direct components emitted in the decay of the excited states produced by photodissociation and the induced components arising from the collisionally populated states. By combining relative intensities of the components with the effective lifetimes of Cs(6P) and K(4P) states, the rate coefficients (in units of 10(-9) cm3 x s(-1)) for the heteronuclear energy-pooling were found to be 2.6 and 3.6, respectively. The contribution to the rate coefficients from other processes are discussed.

Membrane capacitive deionization

NARCIS (Netherlands)

Biesheuvel, P.M.; Wal, van der A.

2010-01-01

Membrane capacitive deionization (MCDI) is an ion-removal process based on applying an electrical potential difference across an aqueous solution which flows in between oppositely placed porous electrodes, in front of which ion-exchange membranes are positioned. Due to the applied potential, ions

3D Printing of Polymer-Bonded Rare-Earth Magnets With a Variable Magnetic Compound Fraction for a Predefined Stray Field.

Science.gov (United States)

Huber, Christian; Abert, Claas; Bruckner, Florian; Groenefeld, Martin; Schuschnigg, Stephan; Teliban, Iulian; Vogler, Christoph; Wautischer, Gregor; Windl, Roman; Suess, Dieter

2017-08-25

Additive manufacturing of polymer-bonded magnets is a recently developed technique, for single-unit production, and for structures that have been impossible to manufacture previously. Also, new possibilities to create a specific stray field around the magnet are triggered. The current work presents a method to 3D print polymer-bonded magnets with a variable magnetic compound fraction distribution. This means the saturation magnetization can be adjusted during the printing process to obtain a required external field of the manufactured magnets. A low-cost, end-user 3D printer with a mixing extruder is used to mix permanent magnetic filaments with pure polyamide (PA12) filaments. The magnetic filaments are compounded, extruded, and characterized for the printing process. To deduce the quality of the manufactured magnets with a variable magnetic compound fraction, an inverse stray field framework is developed. The effectiveness of the printing process and the simulation method is shown. It can also be used to manufacture magnets that produce a predefined stray field in a given region. This opens new possibilities for magnetic sensor applications. This setup and simulation framework allows the design and manufacturing of polymer-bonded permanent magnets, which are impossible to create with conventional methods.

Toxocara nematodes in stray cats from shiraz, southern iran: intensity of infection and molecular identification of the isolates.

Directory of Open Access Journals (Sweden)

Fattaneh Mikaeili

2013-12-01

Full Text Available Toxocara is a common nematode of cats in different parts of Iran. Despite the close association of cats with human, no attempt has been done so far for molecular identification of this nematode in the country. Therefore, current study was performed on identification of some isolates of Toxocara from stray cats in Shiraz, Fars Province, Southern Iran, based on morphological and molecular approaches, and also determination of intensity of infection.This cross-sectional study was carried out on 30 stray cats trapped from different geographical areas of Shiraz in 2011. Adult male and female worms were recovered from digestive tract after dissection of cats. Morphological features using existing keys and PCR-sequencing of ITS-rDNA region and pcox1 mitochondrial l gene were applied for the delineating the species of the parasites.Eight out of 30 cats (26.7% were found infected with Toxocara nematodes. All the isolates were confirmed as Toxocara cati based on morphological features and the sequence of ribosomal and mitochondrial targets. Intensity of infection ranged from one to a maximum of 39 worms per cat, with a mean of 10.25±12.36, and higher abundance of female nematodes.The most prevalent ascaridoid nematode of stray cats in the study area was T. cati and female nematodes were more abundant than that of males. This issue has important role in spreading of eggs in the environment and impact on human toxocariasis.

cLite – A Capacitive Signal Conditioning IC

Directory of Open Access Journals (Sweden)

Krauss Gudrun

2009-12-01

Full Text Available The ZMD31210 cLite™ – a new member of the ZMDI’s Lite™ family of low-cost sensor signal conditioner (SSC integrated circuits – is described in this paper. The cLite™ is the first conditioner for capacitive sensors. Supporting sensor capacitances from 2 pF up to 260 pF, the new sensor signal conditioner covers a wide range of applications. An important aspect of conditioning a capacitance sensor input signal is the adaptation of the capacitive-to-digital converter (CDC input range to the sensor signal span and offset values in order to maximize accuracy. All typical features of the Lite™ family including the digital calibration math based on EEPROM-stored coefficients and a variety of outputs (I2C™, SPI, PDM, and programmable alarms are integrated in the cLite™ as well. Additional features including a sleep mode and low supply voltage range (down to 2.3 V support the low power concept. The paper focuses in particular on the capacitance sensor adaptation and high precision sensor conditioning.

Study on effective MOSFET channel length extracted from gate capacitance

Science.gov (United States)

Tsuji, Katsuhiro; Terada, Kazuo; Fujisaka, Hisato

2018-01-01

The effective channel length (L GCM) of metal-oxide-semiconductor field-effect transistors (MOSFETs) is extracted from the gate capacitances of actual-size MOSFETs, which are measured by charge-injection-induced-error-free charge-based capacitance measurement (CIEF CBCM). To accurately evaluate the capacitances between the gate and the channel of test MOSFETs, the parasitic capacitances are removed by using test MOSFETs having various channel sizes and a source/drain reference device. A strong linear relationship between the gate-channel capacitance and the design channel length is obtained, from which L GCM is extracted. It is found that L GCM is slightly less than the effective channel length (L CRM) extracted from the measured MOSFET drain current. The reason for this is discussed, and it is found that the capacitance between the gate electrode and the source and drain regions affects this extraction.

Changing US Attributes After CS-US Pairings Changes CS-Attribute-Assessments: Evidence for CS-US Associations in Attribute Conditioning.

Science.gov (United States)

Förderer, Sabine; Unkelbach, Christian

2016-03-01

Attribute Conditioning (AC) refers to people's changed assessments of stimuli's (CSs) attributes due to repeated pairing with stimuli (USs) possessing these attributes; for example, when an athletic person (US) is paired with a neutral person (CS), the neutral person is judged to be more athletic after the pairing. We hypothesize that this AC effect is due to CSs' associations with USs rather than direct associations with attributes. Three experiments test this hypothesis by changing US attributes after CS-US pairings. Experiments 1 and 2 conditioned athleticism by pairing neutral men (CSs) with athletic and non-athletic USs. Post-conditioning, USs' athleticism was reversed, which systematically influenced participants' assessment of CS athleticism. Experiment 3 conditioned athleticism and changed USs' musicality after CS-US pairings. This post-conditioning change affected musicality assessments of CSs but did not influence athleticism-assessments. The results indicate that AC effects are based on an associative CS-US-attribute structure. © 2016 by the Society for Personality and Social Psychology, Inc.

A novel vanadosilicate with hexadeca-coordinated Cs+ ions as a highly effective Cs+ remover

International Nuclear Information System (INIS)

Datta, Shuvo Jit; Moon, Won Kyung; Choi, Do Young; Hwang, In Chul; Yoon, Kyung Byung

2014-01-01

The effective removal of 137 Cs + ions from contaminated groundwater and seawater and from radioactive nuclear waste solutions is crucial for public health and for the continuous operation of nuclear power plants. Various 137 Cs + removers have been developed, but more effective 137 Cs + removers are still needed. A novel microporous vanadosilicate with mixed-valence vanadium (V 4+ and V 5+ ) ions is now reported, which shows an excellent ability for Cs + capture and immobilization from groundwater, seawater, and nuclear waste solutions. This material is superior to other known materials in terms of selectivity, capacity, and kinetics, and at very low Cs + concentrations, it was found to be the most effective material for the removal of radioactive Cs + ions under the test conditions. This novel vanadosilicate also contains hexadeca-coordinated Cs + ions, which corresponds to the highest coordination number ever described.

Reducing the capacitance of piezoelectric film sensors

Energy Technology Data Exchange (ETDEWEB)

González, Martín G., E-mail: mggonza@fi.uba.ar [Grupo de Láser, Óptica de Materiales y Aplicaciones Electromagnéticas (GLOMAE), Departamento de Física, Facultad de Ingeniería, Universidad de Buenos Aires, Paseo Colón 850, C1063ACV Buenos Aires (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), C1425FQB Buenos Aires (Argentina); Sorichetti, Patricio A.; Santiago, Guillermo D. [Grupo de Láser, Óptica de Materiales y Aplicaciones Electromagnéticas (GLOMAE), Departamento de Física, Facultad de Ingeniería, Universidad de Buenos Aires, Paseo Colón 850, C1063ACV Buenos Aires (Argentina)

2016-04-15

We present a novel design for large area, wideband, polymer piezoelectric sensor with low capacitance. The large area allows better spatial resolution in applications such as photoacoustic tomography and the reduced capacitance eases the design of fast transimpedance amplifiers. The metalized piezoelectric polymer thin film is segmented into N sections, electrically connected in series. In this way, the total capacitance is reduced by a factor 1/N{sup 2}, whereas the mechanical response and the active area of the sensor are not modified. We show the construction details for a two-section sensor, together with the impedance spectroscopy and impulse response experimental results that validate the design.

Reducing the capacitance of piezoelectric film sensors

International Nuclear Information System (INIS)

González, Martín G.; Sorichetti, Patricio A.; Santiago, Guillermo D.

2016-01-01

We present a novel design for large area, wideband, polymer piezoelectric sensor with low capacitance. The large area allows better spatial resolution in applications such as photoacoustic tomography and the reduced capacitance eases the design of fast transimpedance amplifiers. The metalized piezoelectric polymer thin film is segmented into N sections, electrically connected in series. In this way, the total capacitance is reduced by a factor 1/N"2, whereas the mechanical response and the active area of the sensor are not modified. We show the construction details for a two-section sensor, together with the impedance spectroscopy and impulse response experimental results that validate the design.

Capacitive-discharge-pumped copper bromide vapour laser

International Nuclear Information System (INIS)

Sukhanov, V B; Fedorov, V F; Troitskii, V O; Gubarev, F A; Evtushenko, Gennadii S

2007-01-01

A copper bromide vapour laser pumped by a high-frequency capacitive discharge is developed. It is shown that, by using of a capacitive discharge, it is possible to built a sealed off metal halide vapour laser of a simple design allowing the addition of active impurities into the working medium. (letters)

Measurement of stray neutron doses inside the treatment room from a proton pencil beam scanning system

Czech Academy of Sciences Publication Activity Database

Mojzeszek, N.; Farah, J.; Klodowska, M.; Ploc, Ondřej; Stolarczyk, L.; Waligorski, M. P. R.; Olko, P.

2017-01-01

Roč. 34, č. 2 (2017), s. 80-84 ISSN 1120-1797 Institutional support: RVO:61389005 Keywords : secondary neutrons * proton therapy * pencil beam scanning systtems * out-of-field doses * stray neutron doses * TEPC Subject RIV: FP - Other Medical Disciplines OBOR OECD: Radiology, nuclear medicine and medical imaging Impact factor: 1.990, year: 2016

Hybridization of Single Nanocrystals of Cs4PbBr6 and CsPbBr3.

Science.gov (United States)

Weerd, Chris de; Lin, Junhao; Gomez, Leyre; Fujiwara, Yasufumi; Suenaga, Kazutomo; Gregorkiewicz, Tom

2017-09-07

Nanocrystals of all-inorganic cesium lead halide perovskites (CsPbX 3 , X = Cl, Br, I) feature high absorption and efficient narrow-band emission which renders them promising for future generation of photovoltaic and optoelectronic devices. Colloidal ensembles of these nanocrystals can be conveniently prepared by chemical synthesis. However, in the case of CsPbBr 3 , its synthesis can also yield nanocrystals of Cs 4 PbBr 6 and the properties of the two are easily confused. Here, we investigate in detail the optical characteristics of simultaneously synthesized green-emitting CsPbBr 3 and insulating Cs 4 PbBr 6 nanocrystals. We demonstrate that, in this case, the two materials inevitably hybridize, forming nanoparticles with a spherical shape. The actual amount of these Cs 4 PbBr 6 nanocrystals and nanohybrids increases for synthesis at lower temperatures, i.e., the condition typically used for the development of perovskite CsPbBr 3 nanocrystals with smaller sizes. We use state-of-the-art electron energy loss spectroscopy to characterize nanoparticles at the single object level. This method allows distinguishing between optical characteristics of a pure Cs 4 PbBr 6 and CsPbBr 3 nanocrystal and their nanohybrid. In this way, we resolve some of the recent misconceptions concerning possible visible absorption and emission of Cs 4 PbBr 6 . Our method provides detailed structural characterization, and combined with modeling, we conclusively identify the nanospheres as CsPbBr 3 /Cs 4 PbBr 6 hybrids. We show that the two phases are independent of each other's presence and merge symbiotically. Herein, the optical characteristics of the parent materials are preserved, allowing for an increased absorption in the UV due to Cs 4 PbBr 6 , accompanied by the distinctive efficient green emission resulting from CsPbBr 3 .

Properties of Cs-intercalated single wall carbon nanotubes investigated by 133Cs Nuclear Magnetic resonance

KAUST Repository

Schmid, Marc R.

2012-11-01

In the present study, we investigated Cs-intercalated single wall carbon nanotubes (SWCNTs) using 133Cs Nuclear Magnetic resonance. We show that there are two types of Cs cations depending on the insertion level. Indeed, at low concentrations, Static spectra analysis shows that the Cs (α)+ species are fully ionized, i.e. α equal ca.1, while at higher concentrations a second paramagnetically shifted line appears, indicating the formation of Cs (β)+ ions with β < α ∼ +1. At low concentrations and low temperatures the Cs (α)+ ions exhibit a weak hyperfine coupling to the SWCNT conduction electrons, whereas, at higher temperatures, a thermally activated slow-motion diffusion process of the Cs (α)+ ions occurs along the interstitial channels present within the carbon nanotube bundles. At high concentrations, the Cs (β)+ ions seem to occupy well defined positions relative to the carbon lattice. As a matter of fact, the Korringa relaxation behavior suggests a strong hyperfine coupling between Cs nuclei and conduction electrons in the carbon nanotubes and a partial charge transfer, which suggest a plausible Cs(6s)-C(2p) hybridization. © 2012 Elsevier Ltd. All rights reserved.

Humoral immune response to Dipylidium caninum infection of stray dogs in Taiwan.

Science.gov (United States)

Shin, J W; Liao, W T

2002-04-02

Two kinds of homogeneous proglottid, mature and gravid, of Dipylidium caninum were used as the antigens for immunodiagnosis of canine dipylidiosis in stray dogs in Tainan, Taiwan. The ELISA was performed on 30 serum samples; 24 from dipylidiosis, four from ancylostomosis and two from toxocariosis. The ELISA have specificity and sensitive of 100 and 50% for mature proglottid extract, and 75 and 100%, respectively, for gravid proglottid extract. EITB technique showed two major peptide bands of 94.8 and 97.9kDa were recognized in the sera pool of infected dogs.

Induced radioactivity of materials by stray radiation fields at an electron accelerator

CERN Document Server

Rokni, S H; Gwise, T; Liu, J C; Roesler, S

2002-01-01

Samples of soil, water, aluminum, copper and iron were irradiated in the stray radiation field generated by the interaction of a 28.5 GeV electron beam in a copper-dump in the Beam Dump East facility at the Stanford Linear Accelerator Center. The specific activity induced in the samples was measured by gamma spectroscopy and other techniques. In addition, the isotope production in the samples was calculated with detailed Monte Carlo simulations using the FLUKA code. The calculated activities are compared to the experimental values and differences are discussed.

The split delivery capacitated team orienteering problem

NARCIS (Netherlands)

Archetti, C.; Bianchessi, N.; Speranza, M. G.; Hertz, A.

2014-01-01

In this article, we study the capacitated team orienteering problem where split deliveries are allowed. A set of potential customers is given, each associated with a demand and a profit. The set of customers to be served by a fleet of capacitated vehicles has to be identified in such a way that the

Percoll gradient-centrifuged capacitated mouse sperm have increased fertilizing ability and higher contents of sulfogalactosylglycerolipid and docosahexaenoic acid-containing phosphatidylcholine compared to washed capacitated mouse sperm.

Science.gov (United States)

Furimsky, Anna; Vuong, Ngoc; Xu, Hongbin; Kumarathasan, Premkumari; Xu, Min; Weerachatyanukul, Wattana; Bou Khalil, Maroun; Kates, Morris; Tanphaichitr, Nongnuj

2005-03-01

Although Percoll gradient centrifugation has been used routinely to prepare motile human sperm, its use in preparing motile mouse sperm has been limited. Here, we showed that Percoll gradient-centrifuged (PGC) capacitated mouse sperm had markedly higher fertilizing ability (sperm-zona pellucida [ZP] binding and in vitro fertilization) than washed capacitated mouse sperm. We also showed that the lipid profiles of PGC capacitated sperm and washed capacitated sperm differed significantly. The PGC sperm had much lower contents of cholesterol and phospholipids. This resulted in relative enrichment of male germ cell-specific sulfogalactosylglycerolipid (SGG), a ZP-binding ligand, in PGC capacitated sperm, and this would explain, in part, their increased ZP-binding ability compared with that of washed capacitated sperm. Analyses of phospholipid fatty acyl chains revealed that PGC capacitated sperm were enriched in phosphatidylcholine (PC) molecular species containing highly unsaturated fatty acids (HUFAs), with docosahexaenoic acid (DHA; C22: 6n-3) being the predominant HUFA (42% of total hydrocarbon chains of PC). In contrast, the level of PC-HUFAs comprising arachidonic acid (20:4n-6), docosapentaenoic acid (C22:5n-6), and DHA in washed capacitated sperm was only 27%. Having the highest unsaturation degree among all HUFAs in PC, DHA would enhance membrane fluidity to the uppermost. Therefore, membranes of PGC capacitated sperm would undergo fertilization-related fusion events at higher rates than washed capacitated sperm. These results suggested that PGC mouse sperm should be used in fertilization experiments and that SGG and DHA should be considered to be important biomarkers for sperm fertilizing ability.

Electrochemical capacitance performance of titanium nitride nanoarray

Energy Technology Data Exchange (ETDEWEB)

Xie, Yibing, E-mail: ybxie@seu.edu.cn [School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); Suzhou Research Institute of Southeast University, Suzhou 215123 (China); Wang, Yong [School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); Du, Hongxiu [School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); Suzhou Research Institute of Southeast University, Suzhou 215123 (China)

2013-12-01

Highlights: • TiN nanoarray is formed by a nitridation process of TiO{sub 2} in ammonia atmosphere. • TiN nanoarray exhibits much higher EDLC capacitance than TiO{sub 2} nanoarray. • The specific capacitance of TiN nanoarray achieves a high level of 99.7 mF cm{sup −2}. • A flexible solid-state supercapacitor is constructed by TiN nanoarray and PVA gel. -- Abstract: In this study, titanium nitride (TiN) nanoarrays with a short nanotube and long nanopore structure have been prepared by an anodization process of ultra thin titanium foil in ethylene glycol (EG) solution containing ammonium fluoride, subsequent calcination process in an air atmosphere, and final nitridation process in an ammonia atmosphere. The morphology and microstructure characterization has been conducted using field emission scanning electron microscope and X-ray diffraction. The electrochemical properties have been investigated through cyclic voltammetry and electrochemical impedance spectrum measurements. The electrochemical capacitance performance has been investigated by galvanostatic charge–discharge measurements in the acidic, neural and alkali electrolyte solution. Well-defined TiN nanoarrays contribute a much higher capacitance performance than titania (TiO{sub 2}) in the supercapacitor application due to the extraordinarily improved electrical conductivity. Such an electrochemical capacitance can be further enhanced by increasing aspect ratio of TiN nanoarray from short nanotubes to long nanopores. A flexible supercapacitor has been constructed using two symmetrical TiN nanoarray electrodes and a polyvinyl alcohol (PVA) gel electrolyte with H{sub 2}SO{sub 4}–KCl–H{sub 2}O–EG. Such a supercapacitor has a highly improved potential window and still keeps good electrochemical energy storage. TiN nanoarray with a high aspect ratio can act well as an ultra thin film electrode material of flexible supercapacitor to contribute a superior capacitance performance.

Factors affecting the prevalence of mange-mite infestations in stray dogs of Yucatán, Mexico.

Science.gov (United States)

Rodriguez-Vivas, R I; Ortega-Pacheco, A; Rosado-Aguilar, J A; Bolio, G M E

2003-07-10

The aim of the present study was to determine the factors affecting the prevalence of mange-mite infestations in stray dogs of Yucatán, Mexico. The study was carried out in 200 stray dogs of Mérida capital city of Yucatán, Mexico. Four samples (head, thoracic-abdominal area, extremities and ear) were taken from each animal by skin scraping and examined microscopically in 10% KOH solution to detect the presence of mites. Mites were also collected from the external ear canal of dogs using cotton-tipped swabs. The prevalence of different mite species was calculated. A primary screening was performed using 2xK contingency tables of exposure variables. All variables with PDemodex canis (23.0%) was the most frequent mite, followed by Sarcoptes scabei var. canis (7.0%) and Otodectes cynotis (3.5%). The following factors were found: body condition (bad, OR: 5.35, CI 95%: 1.66-17.3; regular, OR: 3.72, CI 95%: 1.39-9.99) and the presence of macroscopic lesions of dermatosis (OR: 42.80, CI 95%: 13.65-134.24).

Can root electrical capacitance be used to predict root mass in soil?

Science.gov (United States)

Dietrich, R C; Bengough, A G; Jones, H G; White, P J

2013-07-01

Electrical capacitance, measured between an electrode inserted at the base of a plant and an electrode in the rooting substrate, is often linearly correlated with root mass. Electrical capacitance has often been used as an assay for root mass, and is conventionally interpreted using an electrical model in which roots behave as cylindrical capacitors wired in parallel. Recent experiments in hydroponics show that this interpretation is incorrect and a new model has been proposed. Here, the new model is tested in solid substrates. The capacitances of compost and soil were determined as a function of water content, and the capacitances of cereal plants growing in sand or potting compost in the glasshouse, or in the field, were measured under contrasting irrigation regimes. Capacitances of compost and soil increased with increasing water content. At water contents approaching field capacity, compost and soil had capacitances at least an order of magnitude greater than those of plant tissues. For plants growing in solid substrates, wetting the substrate locally around the stem base was both necessary and sufficient to record maximum capacitance, which was correlated with stem cross-sectional area: capacitance of excised stem tissue equalled that of the plant in wet soil. Capacitance measured between two electrodes could be modelled as an electrical circuit in which component capacitors (plant tissue or rooting substrate) are wired in series. The results were consistent with the new physical interpretation of plant capacitance. Substrate capacitance and plant capacitance combine according to standard physical laws. For plants growing in wet substrate, the capacitance measured is largely determined by the tissue between the surface of the substrate and the electrode attached to the plant. Whilst the measured capacitance can, in some circumstances, be correlated with root mass, it is not a direct assay of root mass.

Antibody Detection to Feline Immunodeficiency virus (FIV in stray cats in Ahvaz, southwestern Iran

Directory of Open Access Journals (Sweden)

Mosallanejad, B.

2010-01-01

Full Text Available The present study was performed to determine the prevalence of FIV in stray cat's population of Ahvaz different area. Serum samples were collected from 90 cats from 2005 to 2007. The studied cats were divided into two age groups (3 years and based on clinical signs (such as lymphadenopathy, periodontal diseases, gingivitis, abscess and cashecsi into two groups also. The results were analyzed using Fischer's exact test and Chi-square analysis. Prevalence to FIV antibodies in these cats was 15.55% (14 of 90 by means of ELISA Test Kit, indicating that this virus is present in the ecosystem. The infection had more prevalence in cats above 3 years (78.6%; 11 of 14 compared with cats less than 3 years (21.4%; 3 of 14. Statistical analysis showed significant difference between different age groups (P0.05. Three out of 12 cases (25% which had clinical signs and 11 out of 78 cases (14.1% which hadn’t clinical signs were seropositive. There was no significant difference between the two groups also (P>0.05. This study showed that FIV exist among cat's population of Ahvaz area and separation of companion and stray cats is very important for prevention of disease transmission to companion cats.

Community perception regarding rabies prevention and stray dog control in urban slums in India.

Science.gov (United States)

Herbert, Mrudu; Riyaz Basha, S; Thangaraj, Selvi

2012-12-01

The lack of community awareness about rabies control is a major issue that thwarts efforts to prevent human deaths caused by rabies. The objectives of this study were (1) to assess community knowledge and attitudes about rabies, rabies prevention and stray dog control in an urban slum community and (2) to determine the factors that influence rabies awareness in urban slums. Using a systematic random sampling strategy, 185 participants were selected from 8 urban slums. The data were collected by direct interview using a pre-tested, structured questionnaire. In the study population, 74.1% of the participants had heard about rabies, and 54.1% knew that rabies is a fatal disease. Only 33.5% of the interviewees felt that people in the community had a role to play in controlling the stray dog population. Gender, age and educational status were significantly associated with rabies awareness. Our study indicates that there are gaps in the knowledge and attitudes of individuals living in urban slums regarding rabies prevention and control. Efforts to promote awareness should be targeted at men, older people and uneducated individuals. Copyright © 2012 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

Carbon nanofiber supercapacitors with large areal capacitances

KAUST Repository

McDonough, James R.

2009-01-01

We develop supercapacitor (SC) devices with large per-area capacitances by utilizing three-dimensional (3D) porous substrates. Carbon nanofibers (CNFs) functioning as active SC electrodes are grown on 3D nickel foam. The 3D porous substrates facilitate a mass loading of active electrodes and per-area capacitance as large as 60 mg/ cm2 and 1.2 F/ cm2, respectively. We optimize SC performance by developing an annealing-free CNF growth process that minimizes undesirable nickel carbide formation. Superior per-area capacitances described here suggest that 3D porous substrates are useful in various energy storage devices in which per-area performance is critical. © 2009 American Institute of Physics.

Thermal gravimetric analysis of the CsCuCl3, Cs2CuCl4 and Cs2CuCl4x2H2O crystals

International Nuclear Information System (INIS)

Soboleva, L.V.; Vasil'eva, M.G.

1977-01-01

The thermal characteristics of crystals of Cs 2 CuCl 4 , Cs 2 CuCl 4 x2H 2 O, and CsCuCl 3 were investigated thermogravimetrically. The derivatogram of the Cs 2 CuCl 4 crystal is characterized by the presence of a single endothermal effect at 505 deg C. The derivatogram of the Cs 2 CuCl 4 x2H 2 O crystal contains three endothermal effects: at 40, 135, and 480 deg C. The derivatogram of the CsCuCl 3 crystal shows the presence of two endothermal effects at 142 and 455 deg C. The thermogravimetric data on Cs 2 CuCl 4 and CsCuCl 3 crystals reveal crystal decomposition on melting; hence, these crystals cannot be grown from melts

Capacitive behavior of highly-oxidized graphite

Science.gov (United States)

Ciszewski, Mateusz; Mianowski, Andrzej

2014-09-01

Capacitive behavior of a highly-oxidized graphite is presented in this paper. The graphite oxide was synthesized using an oxidizing mixture of potassium chlorate and concentrated fuming nitric acid. As-oxidized graphite was quantitatively and qualitatively analyzed with respect to the oxygen content and the species of oxygen-containing groups. Electrochemical measurements were performed in a two-electrode symmetric cell using KOH electrolyte. It was shown that prolonged oxidation causes an increase in the oxygen content while the interlayer distance remains constant. Specific capacitance increased with oxygen content in the electrode as a result of pseudo-capacitive effects, from 0.47 to 0.54 F/g for a scan rate of 20 mV/s and 0.67 to 1.15 F/g for a scan rate of 5 mV/s. Better cyclability was observed for the electrode with a higher oxygen amount.

135Cs/137Cs isotopic composition of environmental samples across Europe: Environmental transport and source term emission applications

International Nuclear Information System (INIS)

Snow, Mathew S.; Snyder, Darin C.

2016-01-01

135 Cs/ 137 Cs isotopic analyses represent an important tool for studying the fate and transport of radiocesium in the environment; in this work the 135 Cs/ 137 Cs isotopic composition in environmental samples taken from across Europe is reported. Surface soil and vegetation samples from western Russia, Ukraine, Austria, and Hungary show consistent aged thermal fission product 135 Cs/ 137 Cs isotope ratios of 0.58 ± 0.01 (age corrected to 1/1/15), with the exception of one sample of soil-moss from Hungary which shows an elevated 135 Cs/ 137 Cs ratio of 1.78 ± 0.12. With the exception of the outlier sample from Hungary, surface soil/vegetation data are in quantitative agreement with values previously reported for soils within the Chernobyl exclusion zone, suggesting that radiocesium at these locations is primarily composed of homogenous airborne deposition from Chernobyl. Seawater samples taken from the Irish Sea show 135 Cs/ 137 Cs isotope ratios of 1.22 ± 0.11 (age corrected to 1/1/15), suggesting aged thermal fission product Cs discharged from Sellafield. The differences in 135 Cs/ 137 Cs isotope ratios between Sellafield, Chernobyl, and global nuclear weapons testing fallout indicate that 135 Cs/ 137 Cs isotope ratios can be utilized to discriminate between and track radiocesium transport from different nuclear production source terms, including major emission sources in Europe. - Highlights: • 135 Cs/ 137 Cs useful for tracking anthropogenic environmental radiocesium releases. • European surface soils/vegetation have uniform ratio consistent with Chernobyl. • 135 Cs/ 137 Cs in Irish sea represents thermal fission ratio distinct from Chernobyl. • Can distinguish between major source terms in Europe based on 135 Cs/ 137 Cs.

Reactive barriers for 137Cs retention

International Nuclear Information System (INIS)

Krumhansl, James L.; Brady, Patrick V.; Anderson, Howard L.

2000-01-01

137 Cs was dispersed globally by cold war activities and, more recently, by the Chernobyl accident. Engineered extraction of 137 Cs from soils and groundwaters is exceedingly difficult. Because the half life of 137 Cs is only 30.2 years, remediation might be more effective (and less costly) if 137 Cs bioavailability could be demonstrably limited for even a few decades by use of a reactive barrier. Essentially permanent isolation must be demonstrated in those few settings where high nuclear level wastes contaminated the environment with 135 Cs (half life 2.3x10 6 years) in addition to 137 Cs. Clays are potentially a low-cost barrier to Cs movement, though their long-term effectiveness remains untested. To identify optimal clays for Cs retention Cs resorption was measured for five common clays: Wyoming Montmorillonite (SWy-1), Georgia Kaolinites (KGa-1 and KGa-2), Fithian Illite (F-Ill), and K-Metabentonite (K-Mbt). Exchange sites were pre-saturated with 0.16 M CsCl for 14 days and readily exchangeable Cs was removed by a series of LiNO 3 and LiCl washes. Washed clay were then placed into dialysis bags and the Cs release to the deionized water outside the bags measured. Release rates from 75 to 139 days for SWy-1, K-Mbt and F- 111 were similar; 0.017 to 0.021% sorbed Cs released per day. Both kaolinites released Cs more rapidly (0.12 to 0.05% of the sorbed Cs per day). In a second set of experiments, clays were doped for 110 days and subjected to an extreme and prolonged rinsing process. All the clays exhibited some capacity for irreversible Cs uptake so most soils have some limited ability to act as a natural barrier to Cs migration. However, the residual loading was greatest on K-Mbt (∼ 0.33 wt% Cs). Thus, this clay would be the optimal material for constructing artificial reactive barriers

137Cs in man organism

International Nuclear Information System (INIS)

Marej, A.N.; Barkhudarov, R.M.

1980-01-01

Considered are the levels of 137 Cs content in the organism of adult urban population of the USSR and the main regularities of their alterations during 1962-1974. The non-uniform distribution of levels of 137 Cs buildup in adult population is shown to be connected with soil and geographic conditions. Food stuffs of local production have a noticeable effect on the levels of 137 Cs buildup in the organism of urban population. Calculation methods are used to study 137 Cs administration in a human organism. No significant difference is found between the indexes of 137 Cs content in the organism of rural and urban population. Presented are the levels of 137 Cs content in the organisms of inhabitants of such regions as Far North and Byelorussian-Ukrainian woodlands. Given are the reasons for the increased content of 137 Cs in the organism of rural population of these zones

Carrier Statistics and Quantum Capacitance Models of Graphene Nanoscroll

Directory of Open Access Journals (Sweden)

M. Khaledian

2014-01-01

schematic perfect scroll-like Archimedes spiral. The DOS model was derived at first, while it was later applied to compute the carrier concentration and quantum capacitance model. Furthermore, the carrier concentration and quantum capacitance were modeled for both degenerate and nondegenerate regimes, along with examining the effect of structural parameters and chirality number on the density of state and carrier concentration. Latterly, the temperature effect on the quantum capacitance was studied too.

Programmable differential capacitance-to-voltage converter for MEMS accelerometers

Science.gov (United States)

Royo, G.; Sánchez-Azqueta, C.; Gimeno, C.; Aldea, C.; Celma, S.

2017-05-01

Capacitive MEMS sensors exhibit an excellent noise performance, high sensitivity and low power consumption. They offer a huge range of applications, being the accelerometer one of its main uses. In this work, we present the design of a capacitance-to-voltage converter in CMOS technology to measure the acceleration from the capacitance variations. It is based on a low-power, fully-differential transimpedance amplifier with low input impedance and a very low input noise.

Exploring Polaronic, Excitonic Structures and Luminescence in Cs4PbBr6/CsPbBr3.

Science.gov (United States)

Kang, Byungkyun; Biswas, Koushik

2018-02-15

Among the important family of halide perovskites, one particular case of all-inorganic, 0-D Cs 4 PbBr 6 and 3-D CsPbBr 3 -based nanostructures and thin films is witnessing intense activity due to ultrafast luminescence with high quantum yield. To understand their emissive behavior, we use hybrid density functional calculations to first compare the ground-state electronic structure of the two prospective compounds. The dispersive band edges of CsPbBr 3 do not support self-trapped carriers, which agrees with reports of weak exciton binding energy and high photocurrent. The larger gap 0-D material Cs 4 PbBr 6 , however, reveals polaronic and excitonic features. We show that those lattice-coupled carriers are likely responsible for observed ultraviolet emission around ∼375 nm, reported in bulk Cs 4 PbBr 6 and Cs 4 PbBr 6 /CsPbBr 3 composites. Ionization potential calculations and estimates of type-I band alignment support the notion of quantum confinement leading to fast, green emission from CsPbBr 3 nanostructures embedded in Cs 4 PbBr 6 .

Carrier accumulation and depletion in point-contact capacitance-voltage measurements

Science.gov (United States)

Naitou, Yuichi

2017-11-01

Scanning capacitance microscopy (SCM) is a variation of atomic force microscopy in which a conductive probe tip detects the bias modulated capacitance for the purpose of measuring the nanoscale semiconductor carrier concentration. SCM can be regarded as a point-contact capacitance-voltage system, and its capacitance-voltage properties are different from those of a conventional parallel-plate capacitor. In this study, the charge accumulation and depletion behavior of a semiconductor sample were closely investigated by SCM. By analyzing the tip-sample approach curve, the effective probe tip area and charge depletion depth could be quantitatively determined.

Capacitance-based frequency adjustment of micro piezoelectric vibration generator.

Science.gov (United States)

Mao, Xinhua; He, Qing; Li, Hong; Chu, Dongliang

2014-01-01

Micro piezoelectric vibration generator has a wide application in the field of microelectronics. Its natural frequency is unchanged after being manufactured. However, resonance cannot occur when the natural frequencies of a piezoelectric generator and the source of vibration frequency are not consistent. Output voltage of the piezoelectric generator will sharply decline. It cannot normally supply power for electronic devices. In order to make the natural frequency of the generator approach the frequency of vibration source, the capacitance FM technology is adopted in this paper. Different capacitance FM schemes are designed by different locations of the adjustment layer. The corresponding capacitance FM models have been established. Characteristic and effect of the capacitance FM have been simulated by the FM model. Experimental results show that the natural frequency of the generator could vary from 46.5 Hz to 42.4 Hz when the bypass capacitance value increases from 0 nF to 30 nF. The natural frequency of a piezoelectric vibration generator could be continuously adjusted by this method.

Capacitance-Based Frequency Adjustment of Micro Piezoelectric Vibration Generator

Directory of Open Access Journals (Sweden)

Xinhua Mao

2014-01-01

Full Text Available Micro piezoelectric vibration generator has a wide application in the field of microelectronics. Its natural frequency is unchanged after being manufactured. However, resonance cannot occur when the natural frequencies of a piezoelectric generator and the source of vibration frequency are not consistent. Output voltage of the piezoelectric generator will sharply decline. It cannot normally supply power for electronic devices. In order to make the natural frequency of the generator approach the frequency of vibration source, the capacitance FM technology is adopted in this paper. Different capacitance FM schemes are designed by different locations of the adjustment layer. The corresponding capacitance FM models have been established. Characteristic and effect of the capacitance FM have been simulated by the FM model. Experimental results show that the natural frequency of the generator could vary from 46.5 Hz to 42.4 Hz when the bypass capacitance value increases from 0 nF to 30 nF. The natural frequency of a piezoelectric vibration generator could be continuously adjusted by this method.

Temperature and Pressure Dependence of the Reaction S plus CS (+M) -> CS2 (+M)

DEFF Research Database (Denmark)

Glarborg, Peter; Marshall, Paul; Troe, Juergen

2015-01-01

Experimental data for the unimolecular decomposition of CS2 from the literature are analyzed by unimolecular rate theory with the goal of obtaining rate constants for the reverse reaction S + CS (+M) -> CS2 (+M) over wide temperature and pressure ranges. The results constitute an important input...

A simple method for the deconvolution of 134 Cs/137 Cs peaks in gamma-ray scintillation spectrometry

International Nuclear Information System (INIS)

Darko, E.O.; Osae, E.K.; Schandorf, C.

1998-01-01

A simple method for the deconvolution of 134 Cs / 137 Cs peaks in a given mixture of 134 Cs and 137 Cs using Nal(TI) gamma-ray scintillation spectrometry is described. In this method the 795 keV energy of 134 Cs is used as a reference peak to calculate the activity of the 137 Cs directly from the measured peaks. Certified reference materials were measured using the method and compared with a high resolution gamma-ray spectrometry measurements. The results showed good agreement with the certified values. The method is very simple and does not need any complicated mathematics and computer programme to de- convolute the overlapping 604.7 keV and 661.6 keV peaks of 134 Cs and 137 Cs respectively. (author). 14 refs.; 1 tab., 2 figs

The capacitated team orienteering problem with incomplete service

NARCIS (Netherlands)

Archetti, Claudia; Bianchessi, Nicola; Speranza, M. Grazia

2013-01-01

In this paper we study the capacitated version of the Team Orienteering Problem (TOP), that is the Capacitated TOP (CTOP) and the impact of relaxing the assumption that a customer, if served, must be completely served. We prove that the profit collected by the CTOP with Incomplete Service (CTOP-IS)

Capacitance for carbon capture

International Nuclear Information System (INIS)

Landskron, Kai

2018-01-01

Metal recycling: A sustainable, capacitance-assisted carbon capture and sequestration method (Supercapacitive Swing Adsorption) can turn scrap metal and CO 2 into metal carbonates at an attractive energy cost. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Tunable CsPbBr3/Cs4PbBr6 phase transformation and their optical spectroscopic properties.

Science.gov (United States)

Chen, Xiao; Chen, Daqin; Li, Junni; Fang, Gaoliang; Sheng, Hongchao; Zhong, Jiasong

2018-04-24

As a novel type of promising materials, metal halide perovskites are a rising star in the field of optoelectronics. On this basis, a new frontier of zero-dimensional perovskite-related Cs4PbBr6 with bright green emission and high stability has attracted an enormous amount of attention, even though its photoluminescence still requires to clarification. Herein, the controllable phase transformation between three-dimensional CsPbBr3 and zero-dimensional Cs4PbBr6 is easily achieved in a facile ligand-assisted supersaturated recrystallization synthesis procedure via tuning the amount of surfactants, and their unique optical properties are investigated and compared in detail. Both Cs4PbBr6 and CsPbBr3 produce remarkably intense green luminescence with quantum yields up to 45% and 80%, respectively; however, significantly different emitting behaviors are observed. The fluorescence lifetime of Cs4PbBr6 is much longer than that of CsPbBr3, and photo-blinking is easily detected in the Cs4PbBr6 product, proving that the zero-dimensional Cs4PbBr6 is indeed a highly luminescent perovskite-related material. Additionally, for the first time, tunable emissions over the visible-light spectral region are demonstrated to be achievable via halogen composition modulations in the Cs4PbX6 (X = Cl, Br, I) samples. Our study brings a simple method for the phase control of CsPbBr3/Cs4PbBr6 and demonstrates the intrinsic luminescence nature of the zero-dimensional perovskite-related Cs4PbX6 products.

Automatic Power Factor Correction Using Capacitive Bank

OpenAIRE

Mr.Anant Kumar Tiwari,; Mrs. Durga Sharma

2014-01-01

The power factor correction of electrical loads is a problem common to all industrial companies. Earlier the power factor correction was done by adjusting the capacitive bank manually [1]. The automated power factor corrector (APFC) using capacitive load bank is helpful in providing the power factor correction. Proposed automated project involves measuring the power factor value from the load using microcontroller. The design of this auto-adjustable power factor correction is ...

Electrostatic capacitance and Faraday cage behavior of carbon nanotube forests

Energy Technology Data Exchange (ETDEWEB)

Ya' akobovitz, A. [Mechanosynthesis Group, Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Department of Mechanical Engineering, Faculty of Engineering Sciences, Ben-Gurion University, Beer-Sheva (Israel); Bedewy, M. [Mechanosynthesis Group, Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Hart, A. J. [Mechanosynthesis Group, Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Department of Mechanical Engineering and Laboratory for Manufacturing and Productivity, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2015-02-02

Understanding of the electrostatic properties of carbon nanotube (CNT) forests is essential to enable their integration in microelectronic and micromechanical devices. In this study, we sought to understand how the hierarchical geometry and morphology of CNT forests determines their capacitance. First, we find that at small gaps, solid micropillars have greater capacitance, yet at larger gaps the capacitance of the CNT forests is greater. The surface area of the CNT forest accessible to the electrostatic field was extracted by analysis of the measured capacitance, and, by relating the capacitance to the average density of CNTs in the forest, we find that the penetration depth of the electrostatic field is on the order of several microns. Therefore, CNT forests can behave as a miniature Faraday cage. The unique electrostatic properties of CNT forests could therefore enable their use as long-range proximity sensors and as shielding elements for miniature electronic devices.

Electrostatic capacitance and Faraday cage behavior of carbon nanotube forests

International Nuclear Information System (INIS)

Ya'akobovitz, A.; Bedewy, M.; Hart, A. J.

2015-01-01

Understanding of the electrostatic properties of carbon nanotube (CNT) forests is essential to enable their integration in microelectronic and micromechanical devices. In this study, we sought to understand how the hierarchical geometry and morphology of CNT forests determines their capacitance. First, we find that at small gaps, solid micropillars have greater capacitance, yet at larger gaps the capacitance of the CNT forests is greater. The surface area of the CNT forest accessible to the electrostatic field was extracted by analysis of the measured capacitance, and, by relating the capacitance to the average density of CNTs in the forest, we find that the penetration depth of the electrostatic field is on the order of several microns. Therefore, CNT forests can behave as a miniature Faraday cage. The unique electrostatic properties of CNT forests could therefore enable their use as long-range proximity sensors and as shielding elements for miniature electronic devices

Electrostatic capacitance and Faraday cage behavior of carbon nanotube forests

Science.gov (United States)

Ya'akobovitz, A.; Bedewy, M.; Hart, A. J.

2015-02-01

Understanding of the electrostatic properties of carbon nanotube (CNT) forests is essential to enable their integration in microelectronic and micromechanical devices. In this study, we sought to understand how the hierarchical geometry and morphology of CNT forests determines their capacitance. First, we find that at small gaps, solid micropillars have greater capacitance, yet at larger gaps the capacitance of the CNT forests is greater. The surface area of the CNT forest accessible to the electrostatic field was extracted by analysis of the measured capacitance, and, by relating the capacitance to the average density of CNTs in the forest, we find that the penetration depth of the electrostatic field is on the order of several microns. Therefore, CNT forests can behave as a miniature Faraday cage. The unique electrostatic properties of CNT forests could therefore enable their use as long-range proximity sensors and as shielding elements for miniature electronic devices.

EFFECT OF DIESEL CONTAMINATION ON CAPACITANCE VALUES OF CRUDE PALM OIL

Directory of Open Access Journals (Sweden)

C. H. FIZURA

2014-06-01

Full Text Available Measurement of crude palm oil (CPO contamination is a major concern in CPO quality monitoring. In this study, capacitive sensing technique was used to monitor diesel contamination levels in CPO. A low cost capacitive sensing system was developed by using AD7746 capacitance to digital converter. The capacitance value of CPO samples with different contamination levels (v/v% ranged from 0% to 50% was collected at a room temperature (25°C. The objective of this study is to find a relationship between capacitance values and diesel contamination levels in CPO. The results showed that capacitance value decreased as the diesel contamination levels increased. For the 0% to 50% contamination range, the regression equation was y = 0.0002x2 - 0.0125x + 0.936 with R2 value of 0.96. For the 0% to 10% contamination range (where the percentage was the representative of potential contaminations levels found in CPO the correlation equation was y = -0.02x + 0.95 with R2 value of 0.95. These results indicated that capacitive sensing technique has potential for CPO quality monitoring.

A survey of ectoparasite infestations in stray dogs of Gwang-ju City, Republic of Korea.

Science.gov (United States)

Chee, Jeong Hyun; Kwon, Jung Kee; Cho, Ho Seong; Cho, Kyoung Oh; Lee, Yu Jin; Abd El-Aty, A M; Abdel-Aty, A M; Shin, Sung Shik

2008-03-01

This study was designed to investigate the incidence of ectoparasite infestation among stray dogs in Gwang-ju City, Republic of Korea. A total of 103 stray dogs collected in the Animal Shelter of Gwang-ju City from November 2003 to August 2005 were investigated in this study. Ectoparasites of one or more genera were detected in 45.6% (47 / 103) of the dogs examined for dermatologic lesions and/or skin scrapings (from 3-5 affected areas). Otodectes cynotis was found to be the most frequent parasite (22.3%, 23 / 103), followed by Sarcoptes scabiei var canis (19.4%, 20 / 103), Ctenocephalides canis (6.8%, 7 / 103), Demodex canis (4.9%, 5 / 103), and Trichodectes canis (1.0%, 1 / 103). Monospecific infestation was found in 83.0% (39 / 47) of the affected dogs, whereas concurrent infestations with 2 or more ectoparasites per animal were found in 17.0% (8 / 47) of the affected dogs. Trichodectes canis is reported for the first time in the Republic of Korea. Dogs less than 1 yr old were more heavily infected than other age groups (66.7%), and small-sized dogs of less than 3 kg body weight were more heavily infected than larger dogs (41.7%).

Microhydration of caesium compounds: Cs, CsOH, CsI and Cs₂I₂ complexes with one to three H₂O molecules of nuclear safety interest.

Science.gov (United States)

Sudolská, Mária; Cantrel, Laurent; Cernušák, Ivan

2014-04-01

Structure and thermodynamic properties (standard enthalpies of formation and Gibbs free energies) of hydrated caesium species of nuclear safety interest, Cs, CsOH, CsI and its dimer Cs₂I₂, with one up to three water molecules, are calculated to assess their possible existence in severe accident occurring to a pressurized water reactor. The calculations were performed using the coupled cluster theory including single, double and non-iterative triple substitutions (CCSD(T)) in conjunction with the basis sets (ANO-RCC) developed for scalar relativistic calculations. The second-order spin-free Douglas-Kroll-Hess Hamiltonian was used to account for the scalar relativistic effects. Thermodynamic properties obtained by these correlated ab initio calculations (entropies and thermal capacities at constant pressure as a function of temperature) are used in nuclear accident simulations using ASTEC/SOPHAEROS software. Interaction energies, standard enthalpies and Gibbs free energies of successive water molecules addition determine the ordering of the complexes. CsOH forms the most hydrated stable complexes followed by CsI, Cs₂I₂, and Cs. CsOH still exists in steam atmosphere even at quite high temperature, up to around 1100 K.

High Voltage Bi-directional Flyback Converter for Capacitive Actuator

DEFF Research Database (Denmark)

Thummala, Prasanth; Zhang, Zhe; Andersen, Michael A. E.

2013-01-01

in the converter, including the most dominating parameters of the high voltage transformer viz., self-capacitance and leakage inductance. The specific capacitive load for this converter is a dielectric electro active polymer (DEAP) actuator, which can be used as an effective replacement for conventional actuators...... in a number of applications. In this paper, the discharging energy efficiency definition is introduced. The proposed converter has been experimentally tested with the film capacitive load and the DEAP actuator, and the experimental results are shown together with the efficiency measurements....

1+ collective states of 124Cs and 126Cs nuclei

International Nuclear Information System (INIS)

Ivanova, S.P.; Kuliev, A.A.; Salamov, D.I.

1977-01-01

Within the framework of the random phase approximation β-decay properties of the 1 + states of 124 Cs and 126 Cs have been investigated. Greatly collectivized 1 + states in odd-odd nuclei are produced by the spin-dependent charge-exchange nucleon interaction. For numerical calculations the scheme of single-particle levels in the deformed Saxon-Woods potential has been used

Cesium platinide hydride 4Cs{sub 2}Pt.CsH: an intermetallic double salt featuring metal anions

Energy Technology Data Exchange (ETDEWEB)

Smetana, Volodymyr [Ames Laboratory, US Department of Energy, and Critical Materials Institute, Ames, Iowa, 50011-3020 (United States); Mudring, Anja-Verena [Ames Laboratory, US Department of Energy, and Critical Materials Institute, Ames, Iowa, 50011-3020 (United States); Department of Materials Sciences and Engineering, Iowa State University, Ames, Iowa, 50011-3111 (United States)

2016-11-14

With Cs{sub 9}Pt{sub 4}H a new representative of ionic compounds featuring metal anions can be added to this rare-membered family. Cs{sub 9}Pt{sub 4}H exhibits a complex crystal structure containing Cs{sup +} cations, Pt{sup 2-} and H{sup -} anions. Being a red, transparent compound its band gap is in the visible range of the electromagnetic spectrum and the ionic type of bonding is confirmed by quantum chemical calculations. This cesium platinide hydride can formally be considered as a double salt of the ''alloy'' cesium-platinum, or better cesium platinide, Cs{sub 2}Pt, and the salt cesium hydride CsH according to Cs{sub 9}Pt{sub 4}H≡4 Cs{sub 2}Pt.CsH. (copyright 2016 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Measurement of stray radiation within a scanning proton therapy facility: EURADOS WG9 intercomparison exercise of active dosimetry systems

Czech Academy of Sciences Publication Activity Database

Farah, J.; Mares, V.; Romero-Exposito, M.; Trinkl, S.; Domingo, C.; Dufek, V.; Klodowska, M.; Kubančák, Ján; Knezevic, Z.; Ploc, Ondřej

2015-01-01

Roč. 42, č. 5 (2015), s. 2572-2584 ISSN 0094-2405 Institutional support: RVO:61389005 Keywords : scanning proton therapy * measurement of stray neutrons * spectrometry * ambient dose eyuivalent * intercomparison Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 2.496, year: 2015

Capacitance for carbon capture

Energy Technology Data Exchange (ETDEWEB)

Landskron, Kai [Department of Chemistry, Lehigh University, Bethlehem, PA (United States)

2018-03-26

Metal recycling: A sustainable, capacitance-assisted carbon capture and sequestration method (Supercapacitive Swing Adsorption) can turn scrap metal and CO{sub 2} into metal carbonates at an attractive energy cost. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Capacitance probe for detection of anomalies in non-metallic plastic pipe

Science.gov (United States)

Mathur, Mahendra P.; Spenik, James L.; Condon, Christopher M.; Anderson, Rodney; Driscoll, Daniel J.; Fincham, Jr., William L.; Monazam, Esmail R.

2010-11-23

The disclosure relates to analysis of materials using a capacitive sensor to detect anomalies through comparison of measured capacitances. The capacitive sensor is used in conjunction with a capacitance measurement device, a location device, and a processor in order to generate a capacitance versus location output which may be inspected for the detection and localization of anomalies within the material under test. The components may be carried as payload on an inspection vehicle which may traverse through a pipe interior, allowing evaluation of nonmetallic or plastic pipes when the piping exterior is not accessible. In an embodiment, supporting components are solid-state devices powered by a low voltage on-board power supply, providing for use in environments where voltage levels may be restricted.

Knudsen cell--mass spectrometer studies of cesium--urania interactions. [Cs/sub 2/CO/sub 3/ or CsOH

Energy Technology Data Exchange (ETDEWEB)

Collins, J.L.; Osborne, M.F.; Malinauskas, A.P.; Lorenz, R.A.; Manning, S.R.

1976-06-01

Limited Knudsen cell--mass spectrometer studies were made of the partial pressures of cesium-containing species (assumed to be primarily Cs(g)) over Cs/sub 2/CO/sub 3/ and over phase equilibria involving UO/sub 2/ and probable Cs-U-O compounds formed from mixtures that initially contained either Cs/sub 2/CO/sub 3/-UO/sub 2/ or CsOH-UO/sub 2/. Although additional work is required to further define the equilibria involved, the data demonstrate unambiguously a significant reduction in cesium partial pressures due to probable Cs-U-O compound formation and indicate essentially identical behavior with either CsOH or Cs/sub 2/CO/sub 3/ as the starting material with UO/sub 2/.

Development of certified matrix reference materials for quality assurance of screening 134Cs and 137Cs in food

International Nuclear Information System (INIS)

Ishizu, H.; Yamada, T.

2013-01-01

A certified reference material using activated alumina powder certified for activity of 134 Cs and 137 Cs was developed. The results of the verification and the certification are described. The certified reference material can be used for quality assurance of screening activity measurements of 134 Cs and 137 Cs in food/foodstuffs. Commercially available equipments were experimentally tested using the CRM and another CRM including 40 K. The results of these tests are also shown. - Highlights: • CRM of 134 Cs and 137 Cs using activated alumina was developed. • CRM including 134 Cs, 137 Cs and 40 K was also developed. • Results of experimental performance test of commercial inspection equipments using CRMs were shown

Low Power/Low Voltage Interface Circuitry for Capacitive Sensors

DEFF Research Database (Denmark)

Furst, Claus Efdmann

This thesis focuses mainly on low power/low voltage interface circuits, implemented in CMOS, for capacitive sensors. A brief discussion of demands and possibilities for analog signal processing in the future is presented. Techniques for low power design is presented. This is done by analyzing power...... power consumption. It is shown that the Sigma-Delta modulator is advantageous when embedded in a feedback loop with a mechanical sensor. Here a micro mechanical capacitive microphone. Feedback and detection circuitry for a capacitive microphone is presented. Practical implementations of low power....../low voltage interface circuitry is presented. It is demonstrated that an amplifier optimized for a capacitive microphone implemented in a standard 0.7 micron CMOS technology competes well with a traditional JFET amplifier. Furthermore a low power/low voltage 3rd order Sigma-Delta modulator is presented...

Development of electrical capacitance sensor for tomography

International Nuclear Information System (INIS)

Rasif Mohd Zain; Jaafar Abdullah; Ismail Mustapha; Sazrol Azizee Ariff; Susan Maria Sipaun; Lojius Lombigit

2004-01-01

Electrical capacitance tomography (ECT) is one of the successful methods for imaging 2-phase liquid/gas mixture in oil pipelines and solids/gas mixture in fluidized bed and pneumatic conveying system for improvement of process plants. This paper presents the design development of an electrical capacitance sensor for use with an ECT system. This project is aimed at developing a demonstration ECT unit to be used in the oil pipe line. (Author)

Capacitance-Power-Hysteresis Trilemma in Nanoporous Supercapacitors

OpenAIRE

Lee, Alpha A; Vella, Dominic; Goriely, Alain; Kondrat, Svyatoslav

2015-01-01

Nanoporous supercapacitors are an important player in the field of energy storage that fill the gap between dielectric capacitors and batteries. The key challenge in the development of supercapacitors is the perceived trade-off between capacitance and power delivery. Current efforts to boost the capacitance of nanoporous supercapacitors focus on reducing the pore size so that they can only accommodate a single layer of ions. However, this tight packing compromises the charging dynamics and he...

Capacitance and surface of carbons in supercapacitors

OpenAIRE

Lobato Ortega, Belén; Suárez Fernández, Loreto; Guardia, Laura; Álvarez Centeno, Teresa

2017-01-01

This research is focused in the missing link between the specific surface area of carbons surface and their electrochemical capacitance. Current protocols used for the characterization of carbons applied in supercapacitors electrodes induce inconsistencies in the values of the interfacial capacitance (in F m−2), which is hindering the optimization of supercapacitors. The constraints of both the physisorption of N2 at 77 K and the standard methods used for the isotherm analysis frequently lead...

Ab Initio investigation of cesium monoxide of CsO and CsO+

International Nuclear Information System (INIS)

Zialenina, M.; Kelloe, V.; Cernusak, I.

2015-01-01

Cesium is material with a low work function and, accordingly, atomic Cs has a low value of ionization energy. Therefore cesium is regarded as a good source material for electrons in plasma heating module. One of plasma heating technologies using Cs grid is foreseen as a candidate for the tokamak within the framework of project ITER. Among the possible impurities that can coexist in this module are CsO or CsO + , due to presence of oxygen traces in the heating chamber. We conducted CCSD(T) energy calculations of the cesium oxide (X 2 Σ + ) and its cation (X 3 Σ - ). Here are presented the bond lengths and spectroscopic parameters of both species and ionization energy (IE). Our IE (6.88 eV) is in good agreement with previous theoretical results, experiment indicates substantially lower value (6.22 eV). (authors)

Luminescence properties of undoped CsCaCl3 and CsSrCl3 crystalline scintillators

International Nuclear Information System (INIS)

Fujimoto, Yutaka; Saeki, Keiichiro; Koshimizu, Masanori; Asai, Keisuke; Yanagida, Takayuki

2015-01-01

Intrinsic luminescence properties of undoped CsCaCl 3 and CsSrCl 3 crystalline scintillators were studied. The crystal samples were grown by a vertical Bridgman method. Photoluminescence spectra of the crystals showed Auger-free luminescence (AFL) at 310 nm and self-trapped emission (STE) at 400 nm for CsCaCl 3 and 465 nm for CsSrCl 3 , when vacuum ultraviolet (VUV) light at 84 nm and 160 nm excited the crystals. X-ray excited radioluminescence spectra of the crystals showed some emission bands in the 280-600 nm wavelength range, which are owing to AFL, STE, and other origins such as lattice defects and impurities. Scintillation light yield was 400-300 ph/MeV, and the principal scintillation decay time about 2.5 ns and 12 ns for CsCaCl 3 and 1.8 ns and 13 ns for CsSrCl 3 . (author)

Fast CsI-phoswich detector

International Nuclear Information System (INIS)

Langenbrunner, J.R.

1996-01-01

An improved phoswich radiation detector used pure CsI crystal and a fast plastic scintillator and a single photomultiplier tube. The plastic is arranged to receive incident radiation, and that which passed through then strikes the CsI crystal. Scintillation light from both the plastic and CsI crystal are applied to the photomultiplier tube, with the light from the plastic passing through the crystal without absorption therein. Electronics are provided for analyzing the output of the photomultiplier tube to discriminate responses due to the plastic and the CsI crystal, through short gate and long gate integration, to produce results which are indicative of the characteristics of the different types of incident radiation, even in the presence of large amounts of radiation. The phoswich detector has excellent timing resolution. The scintillators of the CsI- phoswich were chosen for their fast risetimes, of about 3 ns for NE102A, and 30 ns for the pure CsI. 5 figs

Rapid determination of {sup 135}Cs and precise {sup 135}Cs/{sup 137}Cs atomic ratio in environmental samples by single-column chromatography coupled to triple-quadrupole inductively coupled plasma-mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Yang, Guosheng [Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564 (Japan); Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Beijing Engineering Research Center of Radiographic Techniques and Equipment, Beijing 100049 (China); Tazoe, Hirofumi [Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564 (Japan); Yamada, Masatoshi, E-mail: myamada@hirosaki-u.ac.jp [Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564 (Japan)

2016-02-18

For source identification, measurement of {sup 135}Cs/{sup 137}Cs atomic ratio not only provides information apart from the detection of {sup 134}Cs and {sup 137}Cs, but it can also overcome the application limit that measurement of the {sup 134}Cs/{sup 137}Cs ratio has due to the short half-life of {sup 134}Cs (2.06 y). With the recent advancement of ICP-MS, it is necessary to improve the corresponding separation method for rapid and precise {sup 135}Cs/{sup 137}Cs atomic ratio analysis. A novel separation and purification technique was developed for the new generation of triple-quadrupole inductively coupled plasma-mass spectrometry (ICP-MS/MS). The simple chemical separation, incorporating ammonium molybdophosphate selective adsorption of Cs and subsequent single cation-exchange chromatography, removes the majority of isobaric and polyatomic interference elements. Subsequently, the ICP-MS/MS removes residual interference elements and eliminates the peak tailing effect of stable {sup 133}Cs, at m/z 134, 135, and 137. The developed analytical method was successfully applied to measure {sup 135}Cs/{sup 137}Cs atomic ratios and {sup 135}Cs activities in environmental samples (soil and sediment) for radiocesium source identification. - Highlights: • A simple {sup 135}Cs/{sup 137}Cs analytical method was developed. • The separation procedure was based on AMP adsorption and one column chromatography. • {sup 135}Cs/{sup 137}Cs was measured by ICP-MS/MS. • Decontamination factors for Ba, Mo, Sb, and Sn were improved. • {sup 135}Cs/{sup 137}Cs atomic ratios of 0.341–0.351 were found in Japanese soil samples.

Dispersion capacitive de l'interface H2SO4/Pt Capacitive dispersion ...

African Journals Online (AJOL)

Administrateur

Département de Physique, Faculté des Sciences Exactes. Université des .... d'un comportement idéal de la capacité. Au vu .... Figure 2 : Photographie de la cellule Pt/0,5 MH2SO4 (fabriquée par Verre-Lab Constantine) plongée dans un bain.

A novel vanadosilicate with hexadeca-coordinated Cs{sup +} ions as a highly effective Cs{sup +} remover

Energy Technology Data Exchange (ETDEWEB)

Datta, Shuvo Jit; Moon, Won Kyung; Choi, Do Young; Hwang, In Chul; Yoon, Kyung Byung [Sogang Univ., Seoul (Korea, Republic of). Korea Center for Artificial Photosynthesis

2014-07-07

The effective removal of {sup 137}Cs{sup +} ions from contaminated groundwater and seawater and from radioactive nuclear waste solutions is crucial for public health and for the continuous operation of nuclear power plants. Various {sup 137}Cs{sup +} removers have been developed, but more effective {sup 137}Cs{sup +} removers are still needed. A novel microporous vanadosilicate with mixed-valence vanadium (V{sup 4+} and V{sup 5+}) ions is now reported, which shows an excellent ability for Cs{sup +} capture and immobilization from groundwater, seawater, and nuclear waste solutions. This material is superior to other known materials in terms of selectivity, capacity, and kinetics, and at very low Cs{sup +} concentrations, it was found to be the most effective material for the removal of radioactive Cs{sup +} ions under the test conditions. This novel vanadosilicate also contains hexadeca-coordinated Cs{sup +} ions, which corresponds to the highest coordination number ever described.

Capacitance level probe, Type FSK 88

International Nuclear Information System (INIS)

Vogt, W.

2001-01-01

The aim of the capacitive level probe, Type FSK 88, is to supervise the level within vessels continuously and to signalize alterations immediately. Since 1987 the level probe is installed in the pool for burn up fuel elements and in the reactor containment sump of BWRs, PWRs and WWERs. The capacitive level probe of type FSK 88 was qualified for Loss of Coolant Accidents and seismic events according to international rules. The measuring principle takes credit from the fact that the dielectric with different dielectric constants in a condensator changes the capacity of the condensator. (Authors)

Clean energy generation using capacitive electrodes in reverse electrodialysis

NARCIS (Netherlands)

Vermaas, David; Bajracharya, S.; Bastos Sales, B.; Saakes, Michel; Hamelers, B.; Nijmeijer, Dorothea C.

2013-01-01

Capacitive reverse electrodialysis (CRED) is a newly proposed technology to generate electricity from mixing of salt water and fresh water (salinity gradient energy) by using a membrane pile as in reverse electrodialysis (RED) and capacitive electrodes. The salinity difference between salt water and

Accurate sizing of supercapacitors storage system considering its capacitance variation.

OpenAIRE

Trieste , Sony; Bourguet , Salvy; Olivier , Jean-Christophe; Loron , Luc; Le Claire , Jean-Claude

2011-01-01

International audience; This paper highlights the energy errors made for the design of supercapacitors used as a main energy source. First of all, the paper presents the two definitions of capacitance of a capacitance-voltage dependent material. The number of supercapacitors is important for the application purchasing cost. That is why the paper introduces an analytical model and an electrical model along with an identification method for the capacitance variation. This variation is presented...

The behavior of radioactive 137Cs and stable Cs at the isolated undisturbed mountain pond in Fukui, Japan

International Nuclear Information System (INIS)

Iwamoto, Kazumi; Kimura, Makio; Ando, Kenji; Amano, Hikaru

2003-01-01

The behavior of radioactive 137 Cs and stable Cs at the isolated undisturbed mountain pond in Fukui, Japan was studied for the pond water, the sedimentary grains and the soil near the pond. The concentrations of 137 Cs and stable Cs in the pond water ranged from 0.23 to 0.85 Bq/m 3 and from 0.005 to 0.018 mg/m 3 , respectively. The sedimentary grains were sorted by sieving into fractions with diameter from 2 mm to less than 38 μm. The concentrations of 137 Cs and stable Cs in the sorted grains were measured, and those of the adsorbed state were determined by subtracting the concentration of the grain matrix. The adsorbed concentrations increased with decrease in particle diameter and depended less on the kind of samples. The in-situ distribution coefficient Kd depended largely on particle diameter and increased with the decrease in diameter. The values of Kd ranged from about 20 to 1200 m 3 /kg for stable Cs and about 15 to 1000 m 3 /kg for 137 Cs, and the Kd of 137 Cs seemed to be slightly smaller than that of stable Cs. The concentration of stable Cs in the sedimentary mud was found to be close to that of the fine grains. The concentrations of stable Cs in the soil near the pond was about 7.7 mg/kg, and that of 137 Cs was about 0.6 kBq/kg for the surface layer soil and decreased with increase in soil depth. (author)

The Godparent Plan: A Pedagogical Strategy for CS1 Accompaniment and CS2 Pedagogical Enhancement

Directory of Open Access Journals (Sweden)

Pedro Guillermo Feijóo-García

2018-02-01

Full Text Available Courses such as CS1 and CS2 can present an interesting pedagogical challenge when it comes to the theory-practice relationship, along with aspects that involve the course's logistics, the programming language used, and the characteristics of the students involved in the process. This study presents an innovative didactic approach, oriented towards the accompaniment of CS1 students by CS2 students at Universidad El Bosque, Colombia, seeking with this Godparent Plan, to provide a personalized accompaniment to first semester students, whereby CS2 students enhance their domain over concepts and skills while accompanying, explaining and teaching younger peers. The results of this study are favorable, outlining a didactic scheme that can be adapted and replicated in other curricular scenarios.

Design of capacitance measurement module for determining critical cold temperature of tea leaves

Directory of Open Access Journals (Sweden)

Yongzong Lu

2016-12-01

Full Text Available Critical cold temperature is one of the most crucial control factors for crop frost protection. Tea leaf's capacitance has a significant response to cold injury and appears as a peak response to a typical low temperature which is the critical temperature. However, the testing system is complex and inconvenient. In view of these, a tea leaf's critical temperature detector based on capacitance measurement module was designed and developed to measure accurately and conveniently the capacitance. Software was also designed to measure parameters, record data, query data as well as data deletion module. The detector utilized the MSP430F149 MCU as the control core and ILI9320TFT as the display module, and its software was compiled by IAR5.3. Capacitance measurement module was the crucial part in the overall design which was based on the principle of oscillator. Based on hardware debugging and stability analysis of capacitance measurement module, it was found that the output voltage of the capacitance measurement circuit is stable with 0.36% average deviation. The relationship between capacitance and 1/Uc2 was found to be linear distribution with the determination coefficient above 0.99. The result indicated that the output voltage of capacitance measurement module well corresponded to the change in value of the capacitance. The measurement error of the circuit was also within the required range of 0 to 100 pF which meets the requirement of tea leaf's capacitance. Keywords: Tea leaves, Critical cold temperature, Capacitance peak response, Frost protection, Detector

Measurement of gas-liquid two-phase flow in micro-pipes by a capacitance sensor.

Science.gov (United States)

Ji, Haifeng; Li, Huajun; Huang, Zhiyao; Wang, Baoliang; Li, Haiqing

2014-11-26

A capacitance measurement system is developed for the measurement of gas-liquid two-phase flow in glass micro-pipes with inner diameters of 3.96, 2.65 and 1.56 mm, respectively. As a typical flow regime in a micro-pipe two-phase flow system, slug flow is chosen for this investigation. A capacitance sensor is designed and a high-resolution and high-speed capacitance measurement circuit is used to measure the small capacitance signals based on the differential sampling method. The performance and feasibility of the capacitance method are investigated and discussed. The capacitance signal is analyzed, which can reflect the voidage variation of two-phase flow. The gas slug velocity is determined through a cross-correlation technique using two identical capacitance sensors. The simulation and experimental results show that the presented capacitance measurement system is successful. Research work also verifies that the capacitance sensor is an effective method for the measurement of gas liquid two-phase flow parameters in micro-pipes.

Electric field theory and the fallacy of void capacitance

DEFF Research Database (Denmark)

McAllister, Iain Wilson

1991-01-01

The concept of the capacitance of a gaseous void is discussed as applied to electrical insulation science. The most pertinent aspect of the capacitance definition is that of reference to a single-valued potential difference between surfaces. This implies that these surfaces must be surfaces...

Inhibition of calcineurin phosphatase promotes exocytosis of renin from juxtaglomerular cells

DEFF Research Database (Denmark)

Madsen, Kirsten; Friis, Ulla Glenert; Gooch, Jennifer L

2010-01-01

. Simultaneous exposure to EGTA and CsA had no additive effect. The protein kinase A (PKA) blocker RpcAMPs had no effect on the CsA-induced increase in membrane capacitance. Intra- and extracellular application of tacrolimus did not alter membrane capacitance. A calmodulin antagonist (calmidazolium) and Cs...... after CsA treatment of the A-alpha knockout, while renin mRNA was suppressed. We conclude that calcineurin and calcium/calmodulin suppress exocytosis of renin from juxtaglomerular cells independent of PKA....

Correlations between potassium, rubidium and cesium (133Cs and 137Cs) in sporocarps of Suillus variegatus in a Swedish boreal forest

International Nuclear Information System (INIS)

Vinichuk, M.; Rosen, K.; Johanson, K.J.; Dahlberg, A.

2011-01-01

An analysis of sporocarps of ectomycorrhizal fungi Suillus variegatus assessed whether cesium ( 133 Cs and 137 Cs) uptake was correlated with potassium (K) or rubidium (Rb) uptake. The question was whether intraspecific correlations of Rb, K and 133 Cs mass concentrations with 137 Cs activity concentrations in sporocarps were higher within, rather than among, different fungal species, and if genotypic origin of sporocarps within a population affected uptake and correlation. Sporocarps (n = 51) from a Swedish forest population affected by the fallout after the Chernobyl accident were studied. The concentrations were 31.9 ± 6.79 g kg -1 for K (mean ± SD, dwt), 0.40 ± 0.09 g kg -1 for Rb, 8.7 ± 4.36 mg kg -1 for 133 Cs and 63.7 ± 24.2 kBq kg -1 for 137 Cs. The mass concentrations of 133 Cs correlated with 137 Cs activity concentrations (r = 0.61). There was correlation between both 133 Cs concentrations (r = 0.75) and 137 Cs activity concentrations (r = 0.44) and Rb, but the 137 Cs/ 133 Cs isotopic ratio negatively correlated with Rb concentration. Concentrations of K and Rb were weakly correlated (r = 0.51). The 133 Cs mass concentrations, 137 Cs activity concentrations and 137 Cs/ 133 Cs isotopic ratios did not correlate with K concentrations. No differences between, within or, among genotypes in S. variegatus were found. This suggested the relationships between K, Rb, 133 Cs and 137 Cs in sporocarps of S. variegatus is similar to other fungal species. - Highlights: → We studied uptake of Cs ( 133 Cs and 137 Cs), K and Rb by Suillus variegates sporocarps. → Genotypic origin of fungus did not affect uptake of studied elements (isotopes). → Genotypic origin did not affect correlation between Cs ( 133 Cs and 137 Cs), K and Rb.

Measurement of thermal neutron cross section and resonance integral of the reaction {sup 135}Cs(n,{gamma}){sup 136}Cs

Energy Technology Data Exchange (ETDEWEB)

Katoh, Toshio; Nakamura, Shoji; Harada, Hideo [Power Reactor and Nuclear Fuel Development Corp., Tokyo (Japan); Hatsukawa, Yuichi; Shinohara, Nobuo; Hata, Kentaro; Kobayashi, Katsutoshi; Motoishi, Shoji; Tanase, Masakazu

1997-03-01

The thermal neutron(2,200 m/s neutron) capture cross section({sigma}{sub 0}) and the resonance integral(I{sub 0}) of the reaction {sup 135}Cs(n,{gamma}){sup 136}Cs were measured by an activation method. Targets of radioactive cesium, which include {sup 135}Cs, {sup 137}Cs and stable {sup 133}Cs, were irradiated with reactor neutrons within or without a Cd shield case. The ratio of the number of nuclei of {sup 135}Cs to that of {sup 137}Cs was measured with a quadrupole mass spectrometer. This ratio and the ratio of activity of {sup 136}Cs to that of {sup 137}Cs were used for deduction of the {sigma}{sub 0} and the I{sub 0} of {sup 135}Cs. The {sigma}{sub 0} and the I{sub 0} of the reaction {sup 135}Cs(n,{sigma}){sup 136}Cs were 8.3 {+-} 0.3 barn and 38.1 {+-} 2.6 barn, respectively. (author)

Cs/CsPbX3 (X = Br, Cl) epitaxial heteronanocrystals with magic-angle stable/metastable grain boundary

Science.gov (United States)

Zhang, Yumeng; Fan, Baolu; Wu, Wenhui; Fan, Jiyang

2017-05-01

Metal-semiconductor heteronanostructures are crucial building blocks of nanoscale electronic and optoelectronic devices. However, the lattice misfit remains a challenge in constructing heteronanostructures. Perovskite nanocrystals are superior candidates for constructing nanodevices owing to excellent optical, ferroelectric, and superconducting properties. We report the epitaxial growth of lattice-matched Cs/CsPbBr3 metal-semiconductor heteronanocrystals in a liquid medium. The well-crystallized ultrathin Cs layers grow epitaxially on the surfaces of colloidal CsPbBr3 nanocrystals, forming heteronanocrystals with interface diameters of several nanometers. Most of them are pseudomorphic with coherent interfaces free from dislocations, and the others exhibit discrete high-angle grain boundaries. The model based on the calculation of the elastic potential energy of the epilayer and analysis of the near-coincidence sites explains well the experimental result. The analysis shows that the excellent lattice match between the metal and the semiconductor ensures the ideal epitaxial-growth of both Cs/CsPbBr3 and Cs/CsPbCl3 heteronanocrystals. Such metal/semiconductor heteronanocrystals pave the way for developing perovskite-based nanodevices.

Phase Transitions in CsSnCl3 and CsPbBr3 An NMR and NQR Study

Science.gov (United States)

Sharma, Surendra; Weiden, Norbert; Weiss, Alarich

1991-04-01

The phase transitions in CsSnCl3 and CsPbBr3 have been studied by X-ray powder diffraction, by 81Br-NQR and by 'H-, 119Sn-, and 113Cs-NMR. At room temperature in air CsSnCl3 forms a hydrate which can be dehydrated to the monoclinic phase II of CsSnCl3. The high temperature phase I has the Perovskite structure, as the X-ray and NMR experiments show. The three phases of CsPbBr3, known from literature, have been corroborated. The results are discussed in the framework of the group ABX3, A = alkalimetal ion, B = IV main group ion, and X = Halogen ion

Stray dogs as indicators of Toxoplasma gondii distributed in the environment: the first report across an urban-rural gradient in China

Directory of Open Access Journals (Sweden)

Yan Chao

2012-01-01

Full Text Available Abstract Background Toxoplasmosis is an important parasitic zoonosis caused by the protozoan Toxoplasma gondii that is distributed world-wide and infects a variety of hosts. However, the prevalence of T. gondii in the environment (such as soil, water and food is largely unknown. Due to the technical difficulty in oocyst counting directly, an alternative assay using the serologic status of T. gondii in free-living animals, such as stray or free-living dogs, as an indicator, can be used to evaluate environmental contamination indirectly, as they are exposed to the same risk of infection as humans and other animals. Results In the present study, 231 stray or free-living dogs across an urban-rural gradient were examined to assess the frequency of T. gondii in the environment. Specific antibodies to T. gondii were found in 93 dogs (40.3% by enzyme-linked immunosorbent assay (ELISA, and no statistically significant differences were observed in seroprevalences of T. gondii between urban dogs (38.7% and rural dogs (41% (p > 0.05. Conclusions A high seroprevalence of T. gondii in stray or free-living dogs in the present study indicates that there would be a wide distribution and a constant infection pressure of T. gondii across an urban-rural gradient, and the oocysts of T. gondii in the environment would be an important source of infection for humans and other animals both in urban and rural areas in China.

Capacitive Coupling in Double-Circuit Transmission Lines

Directory of Open Access Journals (Sweden)

Zdenka Benesova

2004-01-01

Full Text Available The paper describes an algorithm for calculation of capacitances and charges on conductors in systems with earth wires and in double-circuit overhead lines with respect to phase arrangement. A balanced voltage system is considered. A suitable transposition of individual conductors enables to reduce the electric and magnetic fields in vicinity of overhead lines and to limit the inductive and capacitive linkage. The procedure is illustrated on examples the results of which lead to particular recommendations for designers.

VERA-CS Verification & Validation Plan

Energy Technology Data Exchange (ETDEWEB)

Downar, Thomas [Univ. of Michigan, Ann Arbor, MI (United States)

2017-02-01

This report summarizes the current status of VERA-CS Verification and Validation for PWR Core Follow operation and proposes a multi-phase plan for continuing VERA-CS V&V in FY17 and FY18. The proposed plan recognizes the hierarchical nature of a multi-physics code system such as VERA-CS and the importance of first achieving an acceptable level of V&V on each of the single physics codes before focusing on the V&V of the coupled physics solution. The report summarizes the V&V of each of the single physics codes systems currently used for core follow analysis (ie MPACT, CTF, Multigroup Cross Section Generation, and BISON / Fuel Temperature Tables) and proposes specific actions to achieve a uniformly acceptable level of V&V in FY17. The report also recognizes the ongoing development of other codes important for PWR Core Follow (e.g. TIAMAT, MAMBA3D) and proposes Phase II (FY18) VERA-CS V&V activities in which those codes will also reach an acceptable level of V&V. The report then summarizes the current status of VERA-CS multi-physics V&V for PWR Core Follow and the ongoing PWR Core Follow V&V activities for FY17. An automated procedure and output data format is proposed for standardizing the output for core follow calculations and automatically generating tables and figures for the VERA-CS Latex file. A set of acceptance metrics is also proposed for the evaluation and assessment of core follow results that would be used within the script to automatically flag any results which require further analysis or more detailed explanation prior to being added to the VERA-CS validation base. After the Automation Scripts have been completed and tested using BEAVRS, the VERA-CS plan proposes the Watts Bar cycle depletion cases should be performed with the new cross section library and be included in the first draft of the new VERA-CS manual for release at the end of PoR15. Also, within the constraints imposed by the proprietary nature of plant data, as many as possible of the FY17

Epiphytic fruticose lichens as biomonitors for retrospective evaluation of the 134Cs/137Cs ratio in Fukushima fallout

International Nuclear Information System (INIS)

Ramzaev, V.; Barkovsky, A.; Gromov, A.; Ivanov, S.; Kaduka, M.

2014-01-01

In 2011–2013, sampling of epiphytic fruticose lichens of the genera Usnea, Bryoria and Alectoria was carried out on Sakhalin and Kuril Islands (the Sakhalin region, Russia) to investigate contamination of these organisms with the Fukushima-derived 134 Cs and 137 Cs. Activities of the radionuclides were determined in all 56 samples of lichens taken for the analysis. After correction for radioactive decay (on 15 March 2011), the activity concentrations ranged from 2.1 Bq kg −1 (d.w.) to 52 Bq kg −1 for 134 Cs and from 2.3 Bq kg −1 to 52 Bq kg −1 for 137 Cs. Cesium-134 and 137 Cs activities for the whole set of lichens (n = 56) were strongly positively correlated; Spearman's rank correlation coefficient was calculated as 0.991 (P < 0.01). The activity concentrations of 134 Cs and 137 Cs in Usnea lichens from the Sakhalin and Kunashir islands declined with a factor of three in the period from 2011 to 2013. The average biological half-time for both cesium radionuclides in lichens of the genus Usnea is estimated as 1.3 y. The mean of 0.99 ± 0.10 and median of 0.99 were calculated for the decay corrected 134 Cs/ 137 Cs activities ratios in the lichens (n = 56). The radionuclides ratio in the lichens did not depend on location of sampling site, species and the time that had passed after the Fukushima accident. The regression analysis has shown the background pre-Fukushima level of 137 Cs of 0.4 ± 0.3 Bq kg −1 , whereas the ratio between the Fukushima-borne 134 Cs and 137 Cs in the lichens was estimated as 1.04. The 134 Cs/ 137 Cs activities ratio in lichens from the Sakhalin region is consistent with the ratios reported by others for the heavy contaminated areas on Honshu Island in Japan following the Fukushima accident. The activity concentrations of natural 7 Be in lichens from the Sakhalin region varied between 100 Bq kg −1 and 600 Bq kg −1 ; the activity concentrations did not exhibit temporal variations during a 2y-period of observations. The

An integrated energy-efficient capacitive sensor digital interface circuit

KAUST Repository

Omran, Hesham

2014-06-19

In this paper, we propose an energy-efficient 13-bit capacitive sensor interface circuit. The proposed design fully relies on successive approximation algorithm, which eliminates the need for oversampling and digital decimation filtering, and thus low-power consumption is achieved. The proposed architecture employs a charge amplifier stage to acheive parasitic insensitive operation and fine absolute resolution. Moreover, the output code is not affected by offset voltages or charge injection. The successive approximation algorithm is implemented in the capacitance-domain using a coarse-fine programmable capacitor array, which allows digitizing wide capacitance range in compact area. Analysis for the maximum achievable resolution due to mismatch is provided. The proposed design is insensitive to any reference voltage or current which translates to low temperature sensitivity. The operation of a prototype fabricated in a standard CMOS technology is experimentally verified using both on-chip and off-chip capacitive sensors. Compared to similar prior work, the fabricated prototype achieves and excellent energy efficiency of 34 pJ/step.

Concentration Fluctuations and Capacitive Response in Dense Ionic Solutions.

Science.gov (United States)

Uralcan, Betul; Aksay, Ilhan A; Debenedetti, Pablo G; Limmer, David T

2016-07-07

We use molecular dynamics simulations in a constant potential ensemble to study the effects of solution composition on the electrochemical response of a double layer capacitor. We find that the capacitance first increases with ion concentration following its expected ideal solution behavior but decreases upon approaching a pure ionic liquid in agreement with recent experimental observations. The nonmonotonic behavior of the capacitance as a function of ion concentration results from the competition between the independent motion of solvated ions in the dilute regime and solvation fluctuations in the concentrated regime. Mirroring the capacitance, we find that the characteristic decay length of charge density correlations away from the electrode is also nonmonotonic. The correlation length first decreases with ion concentration as a result of better electrostatic screening but increases with ion concentration as a result of enhanced steric interactions. When charge fluctuations induced by correlated ion-solvent fluctuations are large relative to those induced by the pure ionic liquid, such capacitive behavior is expected to be generic.

Conjugate Image Theory Applied on Capacitive Wireless Power Transfer

Directory of Open Access Journals (Sweden)

Ben Minnaert

2017-01-01

Full Text Available Wireless power transfer using a magnetic field through inductive coupling is steadily entering the market in a broad range of applications. However, for certain applications, capacitive wireless power transfer using electric coupling might be preferable. In order to obtain a maximum power transfer efficiency, an optimal compensation network must be designed at the input and output ports of the capacitive wireless link. In this work, the conjugate image theory is applied to determine this optimal network as a function of the characteristics of the capacitive wireless link, as well for the series as for the parallel topology. The results are compared with the inductive power transfer system. Introduction of a new concept, the coupling function, enables the description of the compensation network of both an inductive and a capacitive system in two elegant equations, valid for the series and the parallel topology. This approach allows better understanding of the fundamentals of the wireless power transfer link, necessary for the design of an efficient system.

All-Ambient Processed Binary CsPbBr3-CsPb2Br5 Perovskites with Synergistic Enhancement for High-Efficiency Cs-Pb-Br-Based Solar Cells.

Science.gov (United States)

Zhang, Xisheng; Jin, Zhiwen; Zhang, Jingru; Bai, Dongliang; Bian, Hui; Wang, Kang; Sun, Jie; Wang, Qian; Liu, Shengzhong Frank

2018-02-28

All-inorganic CsPbBr 3 perovskite solar cells display outstanding stability toward moisture, light soaking, and thermal stressing, demonstrating great potential in tandem solar cells and toward commercialization. Unfortunately, it is still challenging to prepare high-performance CsPbBr 3 films at moderate temperatures. Herein, a uniform, compact CsPbBr 3 film was fabricated using its quantum dot (QD)-based ink precursor. The film was then treated using thiocyanate ethyl acetate (EA) solution in all-ambient conditions to produce a superior CsPbBr 3 -CsPb 2 Br 5 composite film with a larger grain size and minimal defects. The achievement was attributed to the surface dissolution and recrystallization of the existing SCN - and EA. More specifically, the SCN - ions were first absorbed on the Pb atoms, leading to the dissolution and stripping of Cs + and Br - ions from the CsPbBr 3 QDs. On the other hand, the EA solution enhances the diffusion dynamics of surface atoms and the surfactant species. It is found that a small amount of CsPb 2 Br 5 in the composite film gives the best surface passivation, while the Br-rich surface decreases Br vacancies (V Br ) for a prolonged carrier lifetime. As a result, the fabricated device gives a higher solar cell efficiency of 6.81% with an outstanding long-term stability.

The distribution of 137Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden

International Nuclear Information System (INIS)

Vinichuk, M.; Johanson, K.J.; Rydin, H.; Rosen, K.

2010-01-01

We record the distribution of 137 Cs, K, Rb and Cs within individual Sphagnum plants (down to 20 cm depth) as well as 137 Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris 137 Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher 137 Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of 137 Cs within the plants. The patterns of 137 Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The 137 Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10 cm) of the plant (r = 0.50). The strongest correlations were revealed between 137 Cs and Rb (r = 0.89), and between 137 Cs and stable Cs (r = 0.84). This suggests similarities between 137 Cs and Rb in uptake and relocation within the Sphagnum, but that 137 Cs differs from K.

The distribution of (137)Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden.

Science.gov (United States)

Vinichuk, M; Johanson, K J; Rydin, H; Rosén, K

2010-02-01

We record the distribution of (137)Cs, K, Rb and Cs within individual Sphagnum plants (down to 20cm depth) as well as (137)Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris(137)Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher (137)Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of (137)Cs within the plants. The patterns of (137)Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The (137)Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10cm) of the plant (r=0.50). The strongest correlations were revealed between (137)Cs and Rb (r=0.89), and between (137)Cs and stable Cs (r=0.84). This suggests similarities between (137)Cs and Rb in uptake and relocation within the Sphagnum, but that (137)Cs differs from K. Copyright 2009 Elsevier Ltd. All rights reserved.

SU-E-T-598: Parametric Equation for Quick and Reliable Estimate of Stray Neutron Doses in Proton Therapy and Application for Intracranial Tumor Treatments

Energy Technology Data Exchange (ETDEWEB)

Bonfrate, A; Farah, J; Sayah, R; Clairand, I [Institut de Radioprotection et de Surete Nucleaire (IRSN), Fontenay-aux-roses (France); De Marzi, L; Delacroix, S [Institut Curie Centre de Protontherapie d Orsay (CPO), Orsay (France); Herault, J [Centre Antoine Lacassagne (CAL) Cyclotron biomedical, Nice (France); Lee, C [National Cancer Institute, Rockville, MD (United States); Bolch, W [Univ Florida, Gainesville, FL (United States)

2015-06-15

Purpose: Development of a parametric equation suitable for a daily use in routine clinic to provide estimates of stray neutron doses in proton therapy. Methods: Monte Carlo (MC) calculations using the UF-NCI 1-year-old phantom were exercised to determine the variation of stray neutron doses as a function of irradiation parameters while performing intracranial treatments. This was done by individually changing the proton beam energy, modulation width, collimator aperture and thickness, compensator thickness and the air gap size while their impact on neutron doses were put into a single equation. The variation of neutron doses with distance from the target volume was also included in it. Then, a first step consisted in establishing the fitting coefficients by using 221 learning data which were neutron absorbed doses obtained with MC simulations while a second step consisted in validating the final equation. Results: The variation of stray neutron doses with irradiation parameters were fitted with linear, polynomial, etc. model while a power-law model was used to fit the variation of stray neutron doses with the distance from the target volume. The parametric equation fitted well MC simulations while establishing fitting coefficients as the discrepancies on the estimate of neutron absorbed doses were within 10%. The discrepancy can reach ∼25% for the bladder, the farthest organ from the target volume. Finally, the validation showed results in compliance with MC calculations since the discrepancies were also within 10% for head-and-neck and thoracic organs while they can reach ∼25%, again for pelvic organs. Conclusion: The parametric equation presents promising results and will be validated for other target sites as well as other facilities to go towards a universal method.

Controlling trapping potentials and stray electric fields in a microfabricated ion trap through design and compensation

International Nuclear Information System (INIS)

Charles Doret, S; Amini, Jason M; Wright, Kenneth; Volin, Curtis; Killian, Tyler; Ozakin, Arkadas; Denison, Douglas; Hayden, Harley; Pai, C-S; Slusher, Richart E; Harter, Alexa W

2012-01-01

Recent advances in quantum information processing with trapped ions have demonstrated the need for new ion trap architectures capable of holding and manipulating chains of many (>10) ions. Here we present the design and detailed characterization of a new linear trap, microfabricated with scalable complementary metal-oxide-semiconductor (CMOS) techniques, that is well-suited to this challenge. Forty-four individually controlled dc electrodes provide the many degrees of freedom required to construct anharmonic potential wells, shuttle ions, merge and split ion chains, precisely tune secular mode frequencies, and adjust the orientation of trap axes. Microfabricated capacitors on dc electrodes suppress radio-frequency pickup and excess micromotion, while a top-level ground layer simplifies modeling of electric fields and protects trap structures underneath. A localized aperture in the substrate provides access to the trapping region from an oven below, permitting deterministic loading of particular isotopic/elemental sequences via species-selective photoionization. The shapes of the aperture and radio-frequency electrodes are optimized to minimize perturbation of the trapping pseudopotential. Laboratory experiments verify simulated potentials and characterize trapping lifetimes, stray electric fields, and ion heating rates, while measurement and cancellation of spatially-varying stray electric fields permits the formation of nearly-equally spaced ion chains. (paper)

Improving accuracy of electrochemical capacitance and solvation energetics in first-principles calculations

Science.gov (United States)

Sundararaman, Ravishankar; Letchworth-Weaver, Kendra; Schwarz, Kathleen A.

2018-04-01

Reliable first-principles calculations of electrochemical processes require accurate prediction of the interfacial capacitance, a challenge for current computationally efficient continuum solvation methodologies. We develop a model for the double layer of a metallic electrode that reproduces the features of the experimental capacitance of Ag(100) in a non-adsorbing, aqueous electrolyte, including a broad hump in the capacitance near the potential of zero charge and a dip in the capacitance under conditions of low ionic strength. Using this model, we identify the necessary characteristics of a solvation model suitable for first-principles electrochemistry of metal surfaces in non-adsorbing, aqueous electrolytes: dielectric and ionic nonlinearity, and a dielectric-only region at the interface. The dielectric nonlinearity, caused by the saturation of dipole rotational response in water, creates the capacitance hump, while ionic nonlinearity, caused by the compactness of the diffuse layer, generates the capacitance dip seen at low ionic strength. We show that none of the previously developed solvation models simultaneously meet all these criteria. We design the nonlinear electrochemical soft-sphere solvation model which both captures the capacitance features observed experimentally and serves as a general-purpose continuum solvation model.

Contribution of Dielectric Screening to the Total Capacitance of Few-Layer Graphene Electrodes.

Science.gov (United States)

Zhan, Cheng; Jiang, De-en

2016-03-03

We apply joint density functional theory (JDFT), which treats the electrode/electrolyte interface self-consistently, to an electric double-layer capacitor (EDLC) based on few-layer graphene electrodes. The JDFT approach allows us to quantify a third contribution to the total capacitance beyond quantum capacitance (CQ) and EDL capacitance (CEDL). This contribution arises from the dielectric screening of the electric field by the surface of the few-layer graphene electrode, and we therefore term it the dielectric capacitance (CDielec). We find that CDielec becomes significant in affecting the total capacitance when the number of graphene layers in the electrode is more than three. Our investigation sheds new light on the significance of the electrode dielectric screening on the capacitance of few-layer graphene electrodes.

Electrochemical and Capacitive Properties of Carbon Dots/Reduced Graphene Oxide Supercapacitors.

Science.gov (United States)

Dang, Yong-Qiang; Ren, Shao-Zhao; Liu, Guoyang; Cai, Jiangtao; Zhang, Yating; Qiu, Jieshan

2016-11-14

There is much recent interest in graphene-based composite electrode materials because of their excellent mechanical strengths, high electron mobilities, and large specific surface areas. These materials are good candidates for applications in supercapacitors. In this work, a new graphene-based electrode material for supercapacitors was fabricated by anchoring carbon dots (CDs) on reduced graphene oxide (rGO). The capacitive properties of electrodes in aqueous electrolytes were systematically studied by galvanostatic charge-discharge measurements, cyclic voltammetry, and electrochemical impedance spectroscopy. The capacitance of rGO was improved when an appropriate amount of CDs were added to the material. The CD/rGO electrode exhibited a good reversibility, excellent rate capability, fast charge transfer, and high specific capacitance in 1 M H₂SO₄. Its capacitance was as high as 211.9 F/g at a current density of 0.5 A/g. This capacitance was 74.3% higher than that of a pristine rGO electrode (121.6 F/g), and the capacitance of the CD/rGO electrode retained 92.8% of its original value after 1000 cycles at a CDs-to-rGO ratio of 5:1.

Electrochemical and Capacitive Properties of Carbon Dots/Reduced Graphene Oxide Supercapacitors

Directory of Open Access Journals (Sweden)

Yong-Qiang Dang

2016-11-01

Full Text Available There is much recent interest in graphene-based composite electrode materials because of their excellent mechanical strengths, high electron mobilities, and large specific surface areas. These materials are good candidates for applications in supercapacitors. In this work, a new graphene-based electrode material for supercapacitors was fabricated by anchoring carbon dots (CDs on reduced graphene oxide (rGO. The capacitive properties of electrodes in aqueous electrolytes were systematically studied by galvanostatic charge-discharge measurements, cyclic voltammetry, and electrochemical impedance spectroscopy. The capacitance of rGO was improved when an appropriate amount of CDs were added to the material. The CD/rGO electrode exhibited a good reversibility, excellent rate capability, fast charge transfer, and high specific capacitance in 1 M H2SO4. Its capacitance was as high as 211.9 F/g at a current density of 0.5 A/g. This capacitance was 74.3% higher than that of a pristine rGO electrode (121.6 F/g, and the capacitance of the CD/rGO electrode retained 92.8% of its original value after 1000 cycles at a CDs-to-rGO ratio of 5:1.

The Design of Phase-Locked-Loop Circuit for Precision Capacitance Micrometer

Directory of Open Access Journals (Sweden)

Li Shujie

2016-01-01

Full Text Available High precision non-contact micrometer is normally divided into three categories: inductance micrometer, capacitance micrometer and optical interferometer micrometer. The capacitance micrometer is widely used because it has high performance to price ratio. With the improvement of automation level, precision of capacitance micrometer is required higher and higher. Generally, capacitance micrometer consists of the capacitance sensor, capacitance/voltage conversion circuit, and modulation and demodulation circuits. However, due to the existing of resistors, capacitors and other components in the circuit, the phase shift of the carrier signal and the modulated signal might occur. In this case, the specific value of phase shift cannot be determined. Therefore, error caused by the phase shift cannot be eliminated. This will reduce the accuracy of micrometer. In this design, in order to eliminate the impact of the phase shift, the phase-locked-loop (PLL circuit is employed. Through the experiment, the function of tracking the input signal phase and frequency is achieved by the phase-locked-loop circuit. This signal processing method can also be applied to tuber electrical resistance tomography system and other precision measurement circuit.

Uptake and accumulation of 137Cs by upland grassland soil fungi: a potential pool of Cs immobilization

International Nuclear Information System (INIS)

Dighton, J.; Clint, G.M.; Poskitt, J.

1991-01-01

Reports of high concentrations of fallout radiocaesium in basidiomycete fruit bodies after the Chernobyl nuclear reactor accident and speculation that fungi could be long-term 137 Cs accumulators led us to ask if fungi could be long-term 137 Cs accumulators. We used six common upland grassland species to try to estimate their importance in the immobilization of 137 Cs. Uptake of Cs by these species ranged from 44 to 235 nmol Cs g − 1d.w. h − 1. Efflux studies indicate that more than 40% of the Cs taken up is bound within the hyphae. We estimate that the fungal component of the soil could immobilize the total radiocaesium fallout received in upland grasslands following the Chernobyl accident

Capacitive sensing of droplets for microfluidic devices based on thermocapillary actuation.

Science.gov (United States)

Chen, Jian Z; Darhuber, Anton A; Troian, Sandra M; Wagner, Sigurd

2004-10-01

The design and performance of a miniaturized coplanar capacitive sensor is presented whose electrode arrays can also function as resistive microheaters for thermocapillary actuation of liquid films and droplets. Optimal compromise between large capacitive signal and high spatial resolution is obtained for electrode widths comparable to the liquid film thickness measured, in agreement with supporting numerical simulations which include mutual capacitance effects. An interdigitated, variable width design, allowing for wider central electrodes, increases the capacitive signal for liquid structures with non-uniform height profiles. The capacitive resolution and time response of the current design is approximately 0.03 pF and 10 ms, respectively, which makes possible a number of sensing functions for nanoliter droplets. These include detection of droplet position, size, composition or percentage water uptake for hygroscopic liquids. Its rapid response time allows measurements of the rate of mass loss in evaporating droplets.

Calculating and optimizing inter-electrode capacitances of charge division microchannel plate detectors

Energy Technology Data Exchange (ETDEWEB)

Xing, Yan [Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Chen, Bo, E-mail: chenb@ciomp.ac.cn [Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Zhang, Hong-Ji; Wang, Hai-Feng; He, Ling-Ping [Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Jin, Fang-Yuan [Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); University of Chinese Academy of Sciences, Beijing 100049 (China)

2016-04-01

Based on the principle of charge division microchannel plate detectors, the inter-electrode capacitances of charge division anodes which are related to electronic noise of the charge sensitive amplifier and crosstalk effect of the anode are presented. Under all the requirements of charge division microchannel plate detectors such as the imaging linearity and spatial resolution, decreasing the inter-electrode capacitances is one way to improve the imaging performance. In this paper, we illustrate the simulation process of calculating the inter-electrode capacitances. Moreover, a Wedge and Strip (WSZ) anode is fabricated with the picosecond laser micromachining process. Comparing the simulated capacitances and measured capacitances, the three-dimensional finite element method is proved to be valid. Furthermore, by adjusting the design parameters of the anode, the effects of the substrate permittivity, insulation width and the size of pitch on the inter-electrode capacitances have been analysed. The structure of the charge division anode has been optimized based on the simulation data.

3D capacitive tactile sensor using DRIE micromachining

Science.gov (United States)

Chuang, Chiehtang; Chen, Rongshun

2005-07-01

This paper presents a three dimensional micro capacitive tactile sensor that can detect normal and shear forces which is fabricated using deep reactive ion etching (DRIE) bulk silicon micromachining. The tactile sensor consists of a force transmission plate, a symmetric suspension system, and comb electrodes. The sensing character is based on the changes of capacitance between coplanar sense electrodes. High sensitivity is achieved by using the high aspect ratio interdigital electrodes with narrow comb gaps and large overlap areas. The symmetric suspension mechanism of this sensor can easily solve the coupling problem of measurement and increase the stability of the structure. In this paper, the sensor structure is designed, the capacitance variation of the proposed device is theoretically analyzed, and the finite element analysis of mechanical behavior of the structures is performed.

Capacitive sensing of droplets for microfluidic devices based on thermocapillary actuation

OpenAIRE

Chen, Jian Z.; Darhuber, Anton A.; Troian, Sandra M.; Wagner, Sigurd

2004-01-01

The design and performance of a miniaturized coplanar capacitive sensor is presented whose electrode arrays can also function as resistive microheaters for thermocapillary actuation of liquid films and droplets. Optimal compromise between large capacitive signal and high spatial resolution is obtained for electrode widths comparable to the liquid film thickness measured, in agreement with supporting numerical simulations which include mutual capacitance effects. An interdigitated, variable wi...

Photoresponse of CsPbBr3 and Cs4PbBr6 Perovskite Single Crystals.

Science.gov (United States)

Cha, Ji-Hyun; Han, Jae Hoon; Yin, Wenping; Park, Cheolwoo; Park, Yongmin; Ahn, Tae Kyu; Cho, Jeong Ho; Jung, Duk-Young

2017-02-02

High-quality and millimeter-sized perovskite single crystals of CsPbBr 3 and Cs 4 PbBr 6 were prepared in organic solvents and studied for correlation between photocurrent generation and photoluminescence (PL) emission. The CsPbBr 3 crystals, which have a 3D perovskite structure, showed a highly sensitive photoresponse and poor PL signal. In contrast, Cs 4 PbBr 6 crystals, which have a 0D perovskite structure, exhibited more than 1 order of magnitude higher PL intensity than CsPbBr 3 , which generated an ultralow photoresponse under illumination. Their contrasting optoelectrical characteristics were attributed to different exciton binding energies, induced by coordination geometry of the [PbBr 6 ] 4- octahedron sublattices. This work correlated the local structures of lead in the primitive perovskite and its derivatives to PL spectra as well as photoconductivity.

Stray field signatures of Néel textured skyrmions in Ir/Fe/Co/Pt multilayer films

Science.gov (United States)

Yagil, A.; Almoalem, A.; Soumyanarayanan, Anjan; Tan, Anthony K. C.; Raju, M.; Panagopoulos, C.; Auslaender, O. M.

2018-05-01

Skyrmions are nanoscale spin configurations with topological properties that hold great promise for spintronic devices. Here, we establish their Néel texture, helicity, and size in Ir/Fe/Co/Pt multilayer films by constructing a multipole expansion to model their stray field signatures and applying it to magnetic force microscopy images. Furthermore, the demonstrated sensitivity to inhomogeneity in skyrmion properties, coupled with a unique capability to estimate the pinning force governing dynamics, portend broad applicability in the burgeoning field of topological spin textures.

Pulmonary Mycobacterium tuberculosis (Beijing strain infection in a stray dog : clinical communication

Directory of Open Access Journals (Sweden)

S.D.C. Parsons

2008-05-01

Full Text Available Mycobacterium tuberculosis infection in dogs is rarely reported and has not previously been documented in South Africa. A case of a stray Maltese crossbreed dog with extensive multifocal pulmonary tuberculosis due to M. tuberculosis is described. Pulmonary granulomas in this case were poorly encapsulated and contained large numbers of acid-fast bacteria, highlighting the potential for infected companion animals to excrete the pathogen. Treatment of canine tuberculosis is generally not advised, and for this reason, euthanasia of diseased animals must be advocated in most instances. Physicians and veterinarians must be aware that companion animals with active disease caused by M. tuberculosis could act as a potential source of infection.

Postsynthesis Transformation of Insulating Cs4PbBr6 Nanocrystals into Bright Perovskite CsPbBr3 through Physical and Chemical Extraction of CsBr.

Science.gov (United States)

Palazon, Francisco; Urso, Carmine; De Trizio, Luca; Akkerman, Quinten; Marras, Sergio; Locardi, Federico; Nelli, Ilaria; Ferretti, Maurizio; Prato, Mirko; Manna, Liberato

2017-10-13

Perovskite-related Cs 4 PbBr 6 nanocrystals present a "zero-dimensional" crystalline structure where adjacent [PbBr 6 ] 4- octahedra do not share any corners. We show in this work that these nanocrystals can be converted into "three-dimensional" CsPbBr 3 perovskites by extraction of CsBr. This conversion drastically changes the optoelectronic properties of the nanocrystals that become highly photoluminescent. The extraction of CsBr can be achieved either by thermal annealing (physical approach) or by chemical reaction with Prussian Blue (chemical approach). The former approach can be simply carried out on a dried film without addition of any chemicals but does not yield a full transformation. Instead, reaction with Prussian Blue in solution achieves a full transformation into the perovskite phase. This transformation was also verified on the iodide counterpart (Cs 4 PbI 6 ).

Molecular and serological surveillance of canine enteric viruses in stray dogs from Vila do Maio, Cape Verde.

Science.gov (United States)

Castanheira, Pedro; Duarte, Ana; Gil, Solange; Cartaxeiro, Clara; Malta, Manuel; Vieira, Sara; Tavares, Luis

2014-04-23

Infections caused by canine parvovirus, canine distemper virus and canine coronavirus are an important cause of mortality and morbidity in dogs worldwide. Prior to this study, no information was available concerning the incidence and prevalence of these viruses in Cape Verde archipelago. To provide information regarding the health status of the canine population in Vila do Maio, Maio Island, Cape Verde, 53 rectal swabs were collected from 53 stray dogs during 2010 and 93 rectal swabs and 88 blood samples were collected from 125 stray dogs in 2011. All rectal swabs (2010 n = 53; 2011 n = 93) were analysed for the presence of canine parvovirus, canine distemper virus and canine coronavirus nucleic acids by quantitative PCR methods. Specific antibodies against canine distemper virus and canine parvovirus were also assessed (2011 n = 88).From the 2010 sampling, 43.3% (23/53) were positive for canine parvovirus DNA, 11.3% (6/53) for canine distemper virus RNA and 1.9% (1/53) for canine coronavirus RNA. In 2011, the prevalence values for canine parvovirus and canine coronavirus were quite similar to those from the previous year, respectively 44.1% (41/93), and 1.1% (1/93), but canine distemper virus was not detected in any of the samples analysed (0%, 0/93). Antibodies against canine parvovirus were detected in 71.6% (63/88) blood samples and the seroprevalence found for canine distemper virus was 51.1% (45/88). This study discloses the data obtained in a molecular and serological epidemiological surveillance carried out in urban populations of stray and domestic animals. Virus transmission and spreading occurs easily in large dog populations leading to high mortality rates particularly in unvaccinated susceptible animals. In addition, these animals can act as disease reservoirs for wild animal populations by occasional contact. Identification of susceptible wildlife of Maio Island is of upmost importance to evaluate the risk of pathogen spill over from

Enabling Junction Temperature Estimation via Collector-Side Thermo-Sensitive Electrical Parameters through Emitter Stray Inductance in High-Power IGBT Modules

DEFF Research Database (Denmark)

Luo, Haoze; Li, Wuhua; Iannuzzo, Francesco

2018-01-01

This paper proposes the adoption of the inherent emitter stray inductance LeE in high-power insulated gate bipolar transistor (IGBT) modules as a new dynamic thermo-sensitive electrical parameter (d-TSEP). Furthermore, a family of 14 derived dynamic TSEP candidates has been extracted and classified...

3D printed biomimetic whisker-based sensor with co-planar capacitive sensing

NARCIS (Netherlands)

Delamare, John; Sanders, Remco G.P.; Krijnen, Gijsbertus J.M.

2016-01-01

This paper describes the development of a whisker sensor for tactile purposes and which is fabricated by 3D printing. Read-out consists of a capacitive measurement of a co-planar capacitance which is affected by a dielectric that is driven into the electric field of the capacitance. The current

Capacitance-voltage characteristics of GaAs ion-implanted structures

Directory of Open Access Journals (Sweden)

Privalov E. N.

2008-08-01

Full Text Available A noniterative numerical method is proposed to calculate the barrier capacitance of GaAs ion-implanted structures as a function of the Schottky barrier bias. The features of the low- and high-frequency capacitance-voltage characteristics of these structures which are due to the presence of deep traps are elucidated.

A new recontruction algorithm for use with capacitance-based tomography

Directory of Open Access Journals (Sweden)

Ø. Isaksen

1994-01-01

Full Text Available A new reconstruction algorithm for use with capacitance-based process tomography is proposed. A numerical simulator, capable of calculating the capacitances for a particular sensor configuration and flow regime is used together with a parameter representation of the dielectric distribution and an optimization algorithm. The algorithm calculates these parameters and hence the dielectric distribution, by minimizing a function defined as a weighted sum of square differences between the measured and estimated capacitances. The method is tested by using both synthetic and experimental data, and the results are compared with results from the commonly used Linear Back Projection (LBP algorithm. The method is capable of obtaining the correct parameter values for all the flow regimes tested, and does provide a better estimate than the LBP method. The method proves to be very promising, and is a step towards quantitative capacitance tomography.

Preparation and electrochemical capacitance performances of super-hydrophilic conducting polyaniline

Energy Technology Data Exchange (ETDEWEB)

Li, Xingwei; Li, Xiaohan; Dai, Na; Wang, Gengchao; Wang, Zhun [Shanghai Key Laboratory of Advanced Polymeric Materials, Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Meilong Road 130, Shanghai 200237 (China)

2010-08-15

Super-hydrophilic conducting polyaniline was prepared by surface modification of polyaniline using tetraethyl orthosilicate in water/ethanol solution, whereas its conductivity was 4.16 S cm{sup -1} at 25 C. And its electrochemical capacitance performances as an electrode material were evaluated by the cyclic voltammetry and galvanostatic charge/discharge test in 0.1 M H{sub 2}SO{sub 4} aqueous solution. Its initial specific capacitance was 500 F g{sup -1} at a constant current density of 1.5 A g{sup -1}, and the capacitance still reached about 400 F g{sup -1} after 5000 consecutive cycles. Moreover, its capacitance retention ratio was circa 70% with the growth of current densities from 1.5 to 20 A g{sup -1}, indicating excellent rate capability. It would be a promising electrode material for aqueous redox supercapacitors. (author)

Elucidation and functional characterization of CsPSY and CsUGT promoters in Crocus sativus L.

Science.gov (United States)

Bhat, Archana; Mishra, Sonal; Kaul, Sanjana; Dhar, Manoj K

2018-01-01

The dried stigmas of Crocus sativus constitute the saffron, which is considered to be the costliest spice of the world. Saffron is valuable for its constituents, which are mainly apocarotenoids. In order to enhance the production of apocarotenoids, it is imperative to understand the regulation of apocarotenoid biosynthetic pathway. In C. sativus, although the pathway has been elucidated, the information regarding the regulation of the pathwaygenes is scanty. During the present investigation, the characterization of promoters regulating the expression of two important genes i.e. CsPSY and CsUGT was performed. We successfully cloned the promoters of both the genes, which were functionally characterized in Crocus sativus and Nicotiana tabaccum. In silico analysis of the promoters demonstrated the presence of several important cis regulatory elements responding tolight, hormonesand interaction with transcription factors (TFs). Further analysis suggested the regulation of CsPSY promoter by Abscisic acid (ABA) and that of CsUGT by Gibberellic acid (GA). In addition, we also observed ABA and GA mediated modulation in the expression of significant TFs and CsPSY and CsUGT transcripts. Overall, the study addresses issues related to regulation of key genes of apocarotenoid pathway in C.sativus.

Optimal Design and Tradeoffs Analysis for Planar Transformer in High Power DC-DC Converters

DEFF Research Database (Denmark)

Ouyang, Ziwei; Thomsen, Ole Cornelius; Andersen, Michael A. E.

2010-01-01

with optimal behaviors is proposed, which constructs the top layer paralleling with the bottom layer and then in series with the other turns of the primary so that a lower magneto motive force (MMF) ratio m can be obtained as well as minimized AC resistance, leakage inductance and even stray capacitance. A 1...

Transfer of Chernobyl-derived 134Cs, 137Cs, 131I and 103Ru from flowers to honey and pollen

International Nuclear Information System (INIS)

Bunzl, K.; Kracke, W.

1988-01-01

The activity concentrations of 137 Cs, 134 Cs, 131 I and 103 Ru were determined separately in honey and pollen samples collected from a single bee colony during several months after the deposition of Chernobyl fallout. The source of each honey and pollen sample was determined by pollen analysis. Although the activity concentrations in honey and pollen varied with time, the concentrations of 137 Cs and 134 Cs were, in general, higher in pollen than in honey. For 103 Ru and 131 I, these differences were comparatively small. The mean 131 I/ 137 Cs and 103 Ru/ 137 Cs ratios were about one order of magnitude higher in honey than in pollen. The mean 131 I/ 103 Ru ratio was about the same for honey and pollen. This observation, in the light of the corresponding nuclide ratios found in the deposition, suggests that 137 Cs, 134 Cs, 131 I and 103 Ru were taken up by the plant leaves and transported to nectar and pollen. The higher activity concentrations of 137 Cs and 134 Cs in pollen, relative to honey, indicate that these radionuclides behave analogously to potassium, which is also found in higher quantities in pollen. (author)

Relative injectivity and CS-modules

Directory of Open Access Journals (Sweden)

Mahmoud Ahmed Kamal

1994-01-01

Full Text Available In this paper we show that a direct decomposition of modules M⊕N, with N homologically independent to the injective hull of M, is a CS-module if and only if N is injective relative to M and both of M and N are CS-modules. As an application, we prove that a direct sum of a non-singular semisimple module and a quasi-continuous module with zero socle is quasi-continuous. This result is known for quasi-injective modules. But when we confine ourselves to CS-modules we need no conditions on their socles. Then we investigate direct sums of CS-modules which are pairwise relatively inective. We show that every finite direct sum of such modules is a CS-module. This result is known for quasi-continuous modules. For the case of infinite direct sums, one has to add an extra condition. Finally, we briefly discuss modules in which every two direct summands are relatively inective.

Effect of Plasma Membrane Semipermeability in Making the Membrane Electric Double Layer Capacitances Significant.

Science.gov (United States)

Sinha, Shayandev; Sachar, Harnoor Singh; Das, Siddhartha

2018-01-30

Electric double layers (or EDLs) formed at the membrane-electrolyte interface (MEI) and membrane-cytosol interface (MCI) of a charged lipid bilayer plasma membrane develop finitely large capacitances. However, these EDL capacitances are often much larger than the intrinsic capacitance of the membrane, and all of these capacitances are in series. Consequently, the effect of these EDL capacitances in dictating the overall membrane-EDL effective capacitance C eff becomes negligible. In this paper, we challenge this conventional notion pertaining to the membrane-EDL capacitances. We demonstrate that, on the basis of the system parameters, the EDL capacitance for both the permeable and semipermeable membranes can be small enough to influence C eff . For the semipermeable membranes, however, this lowering of the EDL capacitance can be much larger, ensuring a reduction of C eff by more than 20-25%. Furthermore, for the semipermeable membranes, the reduction in C eff is witnessed over a much larger range of system parameters. We attribute such an occurrence to the highly nonintuitive electrostatic potential distribution associated with the recently discovered phenomena of charge-inversion-like electrostatics and the attainment of a positive zeta potential at the MCI for charged semipermeable membranes. We anticipate that our findings will impact the quantification and the identification of a large number of biophysical phenomena that are probed by measuring the plasma membrane capacitance.

Density Functional Theory Calculations of the Quantum Capacitance of Graphene Oxide as a Supercapacitor Electrode.

Science.gov (United States)

Song, Ce; Wang, Jinyan; Meng, Zhaoliang; Hu, Fangyuan; Jian, Xigao

2018-03-31

Graphene oxide has become an attractive electrode-material candidate for supercapacitors thanks to its higher specific capacitance compared to graphene. The quantum capacitance makes relative contributions to the specific capacitance, which is considered as the major limitation of graphene electrodes, while the quantum capacitance of graphene oxide is rarely concerned. This study explores the quantum capacitance of graphene oxide, which bears epoxy and hydroxyl groups on its basal plane, by employing density functional theory (DFT) calculations. The results demonstrate that the total density of states near the Fermi level is significantly enhanced by introducing oxygen-containing groups, which is beneficial for the improvement of the quantum capacitance. Moreover, the quantum capacitances of the graphene oxide with different concentrations of these two oxygen-containing groups are compared, revealing that more epoxy and hydroxyl groups result in a higher quantum capacitance. Notably, the hydroxyl concentration has a considerable effect on the capacitive behavior. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nonlinear dynamics of capacitive charging and desalination by porous electrodes

NARCIS (Netherlands)

Biesheuvel, P.M.; Bazant, M.Z.

2010-01-01

The rapid and efficient exchange of ions between porous electrodes and aqueous solutions is important in many applications, such as electrical energy storage by supercapacitors, water desalination and purification by capacitive deionization, and capacitive extraction of renewable energy from a

A Review of High Voltage Drive Amplifiers for Capacitive Actuators

DEFF Research Database (Denmark)

Huang, Lina; Zhang, Zhe; Andersen, Michael A. E.

2012-01-01

This paper gives an overview of the high voltage amplifiers, which are used to drive capacitive actuators. The amplifiers for both piezoelectric and DEAP (dielectric electroactive polymer) actuator are discussed. The suitable topologies for driving capacitive actuators are illustrated in detail...

Capacitance Regression Modelling Analysis on Latex from Selected Rubber Tree Clones

International Nuclear Information System (INIS)

Rosli, A D; Baharudin, R; Hashim, H; Khairuzzaman, N A; Mohd Sampian, A F; Abdullah, N E; Kamaru'zzaman, M; Sulaiman, M S

2015-01-01

This paper investigates the capacitance regression modelling performance of latex for various rubber tree clones, namely clone 2002, 2008, 2014 and 3001. Conventionally, the rubber tree clones identification are based on observation towards tree features such as shape of leaf, trunk, branching habit and pattern of seeds texture. The former method requires expert persons and very time-consuming. Currently, there is no sensing device based on electrical properties that can be employed to measure different clones from latex samples. Hence, with a hypothesis that the dielectric constant of each clone varies, this paper discusses the development of a capacitance sensor via Capacitance Comparison Bridge (known as capacitance sensor) to measure an output voltage of different latex samples. The proposed sensor is initially tested with 30ml of latex sample prior to gradually addition of dilution water. The output voltage and capacitance obtained from the test are recorded and analyzed using Simple Linear Regression (SLR) model. This work outcome infers that latex clone of 2002 has produced the highest and reliable linear regression line with determination coefficient of 91.24%. In addition, the study also found that the capacitive elements in latex samples deteriorate if it is diluted with higher volume of water. (paper)

The distribution of {sup 137}Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden

Energy Technology Data Exchange (ETDEWEB)

Vinichuk, M., E-mail: mykhailo.vinichuk@mark.slu.s [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Department of Ecology, Zhytomyr State Technological University, 103 Chernyakhovsky Street, 10005 Zhytomyr (Ukraine); Johanson, K.J. [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Rydin, H. [Department of Plant Ecology, Evolutionary Biology Centre, Uppsala University, Norbyvaegen 18D, SE-752 36 Uppsala (Sweden); Rosen, K. [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden)

2010-02-15

We record the distribution of {sup 137}Cs, K, Rb and Cs within individual Sphagnum plants (down to 20 cm depth) as well as {sup 137}Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris{sup 137}Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher {sup 137}Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of {sup 137}Cs within the plants. The patterns of {sup 137}Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The {sup 137}Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10 cm) of the plant (r = 0.50). The strongest correlations were revealed between {sup 137}Cs and Rb (r = 0.89), and between {sup 137}Cs and stable Cs (r = 0.84). This suggests similarities between {sup 137}Cs and Rb in uptake and relocation within the Sphagnum, but that {sup 137}Cs differs from K.

Radiation protection measurements with the variance-covariance method in the stray radiation fields from photon and proton therapy facilities

DEFF Research Database (Denmark)

Lillhök, J.; Persson, L.; Andersen, Claus E.

2017-01-01

, the dose-average lineal energy, the dose-average quality factor and the dose equivalent. The neutron component measured by the detectors at the proton beam was studied through Monte Carlo simulations using the code MCNP6. In the photon beam the stray absorbed dose ranged between 0.3 and 2.4 μGy per monitor...

Capacitive Imaging For Skin Characterization and Solvent Penetration

OpenAIRE

Xiao, P; Zhang, X; Bontozoglou, C

2016-01-01

Capacitive contact imaging has shown potential in measuring skin properties including hydration, micro relief analysis, as well as solvent penetration measurements . Through calibration we can also measure the absolute permittivity of the skin, and from absolute permittivity we then work out the absolute water content (or solvent content) in skin. In this paper, we present our latest study of capacitive contact imaging for skin characterization, i.e. skin hydration and skin damages etc. The r...

Introducing radiality constraints in capacitated location-routing problems

Directory of Open Access Journals (Sweden)

Eliana Mirledy Toro Ocampo

2017-03-01

Full Text Available In this paper, we introduce a unified mathematical formulation for the Capacitated Vehicle Routing Problem (CVRP and for the Capacitated Location Routing Problem (CLRP, adopting radiality constraints in order to guarantee valid routes and eliminate subtours. This idea is inspired by formulations already employed in electric power distribution networks, which requires a radial topology in its operation. The results show that the proposed formulation greatly improves the convergence of the solver.

A Choice Experiment Analysis of the Management of the Stray Dog Population in the UK.

OpenAIRE

Siettou, Christina; Fraser, Iain; Fraser, Rob

2013-01-01

In this paper we present the results of a pilot study investigating the public’s view on the pet overpopulation problem. The Choice Experiment aims to understand the UK public’s awareness of the issue, its views and its willingness to participate and pay for a reduction in the rate of animals being “put to sleep”. Our preliminary results indicate that the public are willing to pay to keep healthy stray dogs alive for longer in Local Authority kennels beyond the current seven day statutory per...

Derivation of 137Cs deposition density from measurement of 137Cs inventories in undisturbed soils

International Nuclear Information System (INIS)

Hien, P.D.; Hiep, H.T.; Quang, N.H.; Huy, N.Q.; Binh, N.T.; Hai, P.S.; Long, N.Q.; Bac, V.T

2012-01-01

The 137 Cs inventories in undisturbed soils were measured for 292 locations across the territory of Vietnam. the logarithmic inventory values were regressed against characteristics of sampling sites, such as geographical coordinates, annual rainfall and physico-chemical parameters of soil. The regression model containing latitude and annual rainfall as determinants could explain 76% of the variations in logarithmic inventory values across the territory. The model part was interpreted as the logarithmic 137 Cs deposition density. At the 95% confidence level, 137 Cs deposition density could be predicted be the model ± 7% relative uncertainty. the latitude mean 137 Cs deposition density increases northward from 237 Bq m -2 to 1097 Bq m -2 , while the corresponding values derived from the UNSCEAR (1969) global pattern are 300 Bq m -2 and 600 Bq m -2 . High 137 Cs inputs were found in high-rainfall areas in northern and central parts of the territory. (author)

Quantum decrease of capacitance in a nanometer-sized tunnel junction

Science.gov (United States)

Untiedt, C.; Saenz, G.; Olivera, B.; Corso, M.; Sabater, C.; Pascual, J. I.

2013-03-01

We have studied the capacitance of the tunnel junction defined by the tip and sample of a Scanning Tunnelling Microscope through the measurement of the electrostatic forces and impedance of the junction. A decrease of the capacitance when a tunnel current is present has shown to be a more general phenomenon as previously reported in other systems. On another hand, an unexpected reduction of the capacitance is also observed when increasing the applied voltage above the work function energy of the electrodes to the Field Emission (FE) regime, and the decrease of capacitance due to a single FE-Resonance has been characterized. All these effects should be considered when doing measurements of the electronic characteristics of nanometer-sized electronic devices and have been neglected up to date. Spanish government (FIS2010-21883-C02-01, CONSOLIDER CSD2007-0010), Comunidad Valenciana (ACOMP/2012/127 and PROMETEO/2012/011)

Examination of the role of CS{sub 2} in the CS{sub 2}/NMP mixed solvents to coal extraction

Energy Technology Data Exchange (ETDEWEB)

Shui, Hengfu; Wang, Zhicai [School of Chemistry and Chemical Engineering, Anhui University of Technology, 243002 Maanshan Anhui (China); Gao, Jinsheng [Department of Energy Resources and Chemical Engineering, East China University of Science & amp; Technology, 200237 Shanghai (China)

2006-02-15

The roles of CS{sub 2} in the CS{sub 2}/NMP mixed solvent to coal extraction and solubilization were investigated in this study. There was little effect of removing of CS{sub 2} from the solutions on the solubilities of UF coal extract and pyridine insoluble (PI) of the extract in the NMP/CS{sub 2} mixed solvent, suggesting that NMP has high enough solubilities to the UF coal extract and PI. Six Argonne different rank coals were extracted with the CS{sub 2}/NMP mixed solvent and NMP, respectively. It was found that the extraction yield difference between NMP and CS{sub 2}/NMP mixed solvent for UF coal is largely deviated from the curve obtained for the other 5 coals, suggesting that the pre-swelling of CS{sub 2} in the mixed solvent may be one of important roles for high extraction yield of UF coal in the CS{sub 2}/NMP mixed solvent. FTIR indicated that there was a strong interaction between CS{sub 2} and NMP in the CS{sub 2}/NMP mixed solvent of 1:1 volume ratio, which made the strong absorbance at 2156 cm{sup -1} in the FTIR spectra, and this interaction may disrupt the dipole based association of NMP thus making the CS{sub 2}/NMP mixed solvent lower viscosity, to penetrate more quickly into the network structure of coal, resulting in the larger solvent partner (NMP) to enter and break the stronger coal-coal interactions. (author)

Measurements of the Effects of Smoke on Active Circuits

International Nuclear Information System (INIS)

Tanaka, T.J.

1999-01-01

Smoke has long been recognized as the most common source of fire damage to electrical equipment; however, most failures have been analyzed after the fire was out and the smoke vented. The effects caused while the smoke is still in the air have not been explored. Such effects have implications for new digital equipment being installed in nuclear reactors. The U.S. Nuclear Regulatory Commission is sponsoring work to determine the impact of smoke on digital instrumentation and control. As part of this program, Sandia National Laboratories has tested simple active circuits to determine how smoke affects them. These tests included the study of three possible failure modes on a functional board: (1) circuit bridging, (2) corrosion (metal loss), and (3) induction of stray capacitance. The performance of nine different circuits was measured continuously on bare and conformably coated boards during smoke exposures lasting 1 hour each and continued for 24 hours after the exposure started. The circuit that was most affected by smoke (100% change in measured values) was the one most sensitive to circuit bridging. Its high impedance (50 MOmega) was shorted during the exposure, but in some cases recovered after the smoke was vented. The other two failure modes, corrosion and induced stray capacitance, caused little change in the function of the circuits. The smoke permanently increased resistance of the circuit tested for corrosion, implying that the cent acts were corroded. However, the change was very small (< 2%). The stray-capacitance test circuit showed very little change after a smoke exposure in either the short or long term. The results of the tests suggest that conformal coatings and type of circuit are major considerations when designing digital circuitry to be used in critical control systems

Measurements of the effects of smoke on active circuits

International Nuclear Information System (INIS)

Tanaka, T.J.

1998-01-01

Smoke has long been recognized as the most common source of fire damage to electrical equipment; however, most failures have been analyzed after the fire was out and the smoke vented. The effects caused while the smoke is still in the air have not been explored. Such effects have implications for new digital equipment being installed in nuclear reactors. The US Nuclear Regulatory Commission is sponsoring work to determine the impact of smoke on digital instrumentation and control. As part of this program, Sandia National Laboratories has tested simple active circuits to determine how smoke affects them. These tests included the study of three possible failure modes on a functional board: (1) circuit bridging, (2) corrosion (metal loss), and (3) induction of stray capacitance. The performance of nine different circuits was measured continuously on bare and conformally coated boards during smoke exposures lasting 1 hour each and continued for 24 hours after the exposure started. The circuit that was most affected by smoke (100% change in measured values) was the one most sensitive to circuit bridging. Its high impedance (50 Mohm) was shorted during the exposure, but in some cases recovered after the smoke was vented. The other two failure modes, corrosion and induced stray capacitance, caused little change in the function of the circuits. The smoke permanently increased resistance of the circuit tested for corrosion, implying that the contacts were corroded. However, the change was very small (< 2%). The stray capacitance test circuit showed very little change after a smoke exposure in either the short or long term. The results of the tests suggest that conformal coatings and type of circuit are major considerations when designing digital circuitry to be used in critical control systems

Transformation of Sintered CsPbBr3 Nanocrystals to Cubic CsPbI3 and Gradient CsPbBrxI3-x through Halide Exchange.

Science.gov (United States)

Hoffman, Jacob B; Schleper, A Lennart; Kamat, Prashant V

2016-07-13

All-inorganic cesium lead halide (CsPbX3, X = Br(-), I(-)) perovskites could potentially provide comparable photovoltaic performance with enhanced stability compared to organic-inorganic lead halide species. However, small-bandgap cubic CsPbI3 has been difficult to study due to challenges forming CsPbI3 in the cubic phase. Here, a low-temperature procedure to form cubic CsPbI3 has been developed through a halide exchange reaction using films of sintered CsPbBr3 nanocrystals. The reaction was found to be strongly dependent upon temperature, featuring an Arrhenius relationship. Additionally, film thickness played a significant role in determining internal film structure at intermediate reaction times. Thin films (50 nm) showed only a small distribution of CsPbBrxI3-x species, while thicker films (350 nm) exhibited much broader distributions. Furthermore, internal film structure was ordered, featuring a compositional gradient within film. Transient absorption spectroscopy showed the influence of halide exchange on the excited state of the material. In thicker films, charge carriers were rapidly transferred to iodide-rich regions near the film surface within the first several picoseconds after excitation. This ultrafast vectorial charge-transfer process illustrates the potential of utilizing compositional gradients to direct charge flow in perovskite-based photovoltaics.

A new capacitive/resistive probe method for studying magnetic surfaces

International Nuclear Information System (INIS)

Kitajima, Sumio; Takayama, Masakazu; Zama, Tatsuya; Takaya, Kazuhiro; Takeuchi, Nobunao; Watanabe, Hiroshige

1991-01-01

A new capacitive/resistive probe method for mapping the magnetic surfaces from resistance or capacitance between a magnetic surface and a vacuum vessel was developed and tested. Those resistances and capacitances can be regarded as components of a simple electrical bridge circuit. This method exploits electrical transient response of the bridge circuit for a square pulse. From equiresistance or equicapacitance points, the magnetic surface structure can be deduced. Measurements on the Tohoku University Heliac, which is a small-size standard heliac, show good agreement with numerical calculations. This method is particularly useful for pulse-operated machines. (author)

Some observations on stray magnetic fields and power outputs from short-wave diathermy equipment

Energy Technology Data Exchange (ETDEWEB)

Lau, R.W.M.; Dunscombe, P.B.

1984-04-01

Recent years have seen increasing interest in the possible hazards arising from the use of nonionizing electromagnetic radiation. Relatively large and potentially hazardous fields are to be found in the vicinity of short-wave and microwave equipment used in physiotherapy departments to produce therapeutic temperature rises. This note reports the results of measurements of the stray magnetic field and power output of a conventional short-wave diathermy unit when applied to tissue-equivalent phantoms. The dependence of these quantities on the variables, i.e. power setting of the unit, capacitor plate size, phantom size and phantom-capacitor plate separation, are discussed.

Enhanced Capacitance of Hybrid Layered Graphene/Nickel Nanocomposite for Supercapacitors

Science.gov (United States)

Mohd Zaid, Norsaadatul Akmal; Idris, Nurul Hayati

2016-08-01

In this work, Ni nanoparticles were directly decorated on graphene (G) nanosheets via mechanical ball milling. Based on transmission electron microscopy observations, the Ni nanoparticles were well dispersed and attached to the G nanosheet without any agglomerations. Electrochemical results showed that the capacitance of a G/Ni nanocomposite was 275 F g-1 at a current density of 2 A g-1, which is higher than the capacitance of bare G (145 F g-1) and bare Ni (3 F g-1). The G/Ni electrode also showed superior performance at a high current density, exhibiting a capacitance of 190 F g-1 at a current density of 5 A g-1 and a capacitance of 144 F g-1 at a current density of 10 A g-1. The equivalent series resistance for G/Ni nanocomposites also decreased. The enhanced performance of this hybrid supercapacitor is best described by the synergistic effect, i.e. dual charge-storage mechanism, which is demonstrated by electrical double layer and pseudocapacitance materials. Moreover, a high specific surface area and electrical conductivity of the materials enhanced the capacitance. These results indicate that the G/Ni nanocomposite is a potential supercapacitor.

New Type Multielectrode Capacitance Sensor for Liquid Level

Energy Technology Data Exchange (ETDEWEB)

Zhao, Y R [China University of Petroleum (Huadong), Qingdao (China); Shi, A P [Shandong University of Science and Technology, Qingdao (China); Chen, G Q [Shandong University of Science and Technology, Qingdao (China); Chang, Y Y [Shandong University of Science and Technology, Qingdao (China); Hang, Z [Shandong University of Science and Technology, Qingdao (China); Liu, B M [Binzhou University, Binzhou (China)

2006-10-15

This paper introduces the design of a new type multielectrode capacitance sensor for liquid level. The system regards electric field sensor MC33794 as the core and applies microcontroller MC9S12DJ128 to realize intelligent liquid level monitoring system, which overcomes the disadvantages of the traditional capacitance sensor, improves on the anti-jamming ability and the measurement precision and simplifies the system structure. Finally, the paper sums up the design of the system.

Detecting size and shape of bodies capacitatively

International Nuclear Information System (INIS)

Walton, H.

1980-01-01

The size and shape of a body is determined by rolling it between the plates of capacitors and measuring the capacitance changes. A capacitor comprising two parallel, spaced wires inclined to the rolling direction and above and below the rolling body scans sections of the body along its longitudinal axis, another determines the body's lengths and a third comprising two non-parallel wires determines the position of the body. The capacitance changes are compared with those produced by a body of known size and shape so that the size and shape of the body can be determined. (author)

Prevalence of Echinococcus granulosus taeniasis in stray dogs in the region of Constantine (North-East Algeria).

Science.gov (United States)

Kohil, K; Benchikh El Fegoun, M C; Gharbi, M

2017-10-01

In North Africa, the domestic dog is regarded as the main reservoir for infection by Echinococcus granulosus of domestic livestock and man. In Algeria, there is very little data on the rate of infestation of dogs, while the prevalence of E. granulosus in the definitive host is a very reliable marker of the potential risk of transmission of cystic tapeworm to humans and livestock. To find out this information, a survey was conducted to assess the prevalence of infection with E. granulosus in stray dogs in the region of Constantine (North-East Algeria). We autopsied and examined 120 stray dogs, 22 (18.3%) of which were infected with E. granulosus, with an average intensity of infestation of 249 worms. The prevalence in the area of survey was evaluated: 15.5% (14/90) and 26.6% (8/30) dogs were parasitized by E. granulosus in urban and rural areas respectively. The influence of age on the rate of infection was very marked. In addition, the appreciation of the prevalence of parasitism by cestodes as a whole showed that 56 (46.6%) animals out of 120 were infected. Facing such a situation of endemic tapeworm parasitism, with a potential risk of transmission to humans, there is an urgent need to take measures to control and break the epidemiological cycles of the parasite.

Classic and Quantum Capacitances in Bernal Bilayer and Trilayer Graphene Field Effect Transistor

Directory of Open Access Journals (Sweden)

Hatef Sadeghi

2013-01-01

Full Text Available Our focus in this study is on characterizing the capacitance voltage (C-V behavior of Bernal stacking bilayer graphene (BG and trilayer graphene (TG as the channel of FET devices. The analytical models of quantum capacitance (QC of BG and TG are presented. Although QC is smaller than the classic capacitance in conventional devices, its contribution to the total metal oxide semiconductor capacitor in graphene-based FET devices becomes significant in the nanoscale. Our calculation shows that QC increases with gate voltage in both BG and TG and decreases with temperature with some fluctuations. However, in bilayer graphene the fluctuation is higher due to its tunable band structure with external electric fields. In similar temperature and size, QC in metal oxide BG is higher than metal oxide TG configuration. Moreover, in both BG and TG, total capacitance is more affected by classic capacitance as the distance between gate electrode and channel increases. However, QC is more dominant when the channel becomes thinner into the nanoscale, and therefore we mostly deal with quantum capacitance in top gate in contrast with bottom gate that the classic capacitance is dominant.

Contamination of current-clamp measurement of neuron capacitance by voltage-dependent phenomena

Science.gov (United States)

White, William E.

2013-01-01

Measuring neuron capacitance is important for morphological description, conductance characterization, and neuron modeling. One method to estimate capacitance is to inject current pulses into a neuron and fit the resulting changes in membrane potential with multiple exponentials; if the neuron is purely passive, the amplitude and time constant of the slowest exponential give neuron capacitance (Major G, Evans JD, Jack JJ. Biophys J 65: 423–449, 1993). Golowasch et al. (Golowasch J, Thomas G, Taylor AL, Patel A, Pineda A, Khalil C, Nadim F. J Neurophysiol 102: 2161–2175, 2009) have shown that this is the best method for measuring the capacitance of nonisopotential (i.e., most) neurons. However, prior work has not tested for, or examined how much error would be introduced by, slow voltage-dependent phenomena possibly present at the membrane potentials typically used in such work. We investigated this issue in lobster (Panulirus interruptus) stomatogastric neurons by performing current clamp-based capacitance measurements at multiple membrane potentials. A slow, voltage-dependent phenomenon consistent with residual voltage-dependent conductances was present at all tested membrane potentials (−95 to −35 mV). This phenomenon was the slowest component of the neuron's voltage response, and failure to recognize and exclude it would lead to capacitance overestimates of several hundredfold. Most methods of estimating capacitance depend on the absence of voltage-dependent phenomena. Our demonstration that such phenomena make nonnegligible contributions to neuron responses even at well-hyperpolarized membrane potentials highlights the critical importance of checking for such phenomena in all work measuring neuron capacitance. We show here how to identify such phenomena and minimize their contaminating influence. PMID:23576698

Lightweight linear alternators with and without capacitive tuning

Science.gov (United States)

Niedra, Janis M.

1993-06-01

Permanent magnet excited linear alternators rated tens of kW and coupled to free-piston Stirling engines are presently viewed as promising candidates for long term generation of electric power in both space and terrestrial applications. Series capacitive cancellation of the internal inductive reactance of such alternators was considered a viable way to both increase power extraction and to suppress unstable modes of the thermodynamic oscillation. Idealized toroidal and cylindrical alternator geometries are used for a comparative study of the issues of specific mass and capacitive tuning, subject to stability criteria. The analysis shows that the stator mass of an alternator designed to be capacitively tuned is always greater than the minimum achievable stator mass of an alternator designed with no capacitors, assuming equal utilization of materials ratings and the same frequency and power to a resistive load. This conclusion is not substantially altered when the usually lesser masses of the magnets and of any capacitors are added. Within the reported stability requirements and under circumstances of normal materials ratings, this study finds no clear advantage to capacitive tuning. Comparative plots of the various constituent masses are presented versus the internal power factor taken as a design degree of freedom. The explicit formulas developed for stator core, coil, capacitor, and magnet masses and for the degree of magnet utilization provide useful estimates of scaling effects.

Mechanical strain can switch the sign of quantum capacitance from positive to negative.

Science.gov (United States)

Hanlumyuang, Yuranan; Li, Xiaobao; Sharma, Pradeep

2014-11-14

Quantum capacitance is a fundamental quantity that can directly reveal many-body interactions among electrons and is expected to play a critical role in nanoelectronics. One of the many tantalizing recent physical revelations about quantum capacitance is that it can possess a negative value, hence allowing for the possibility of enhancing the overall capacitance in some particular material systems beyond the scaling predicted by classical electrostatics. Using detailed quantum mechanical simulations, we found an intriguing result that mechanical strains can tune both signs and values of quantum capacitance. We used a small coaxially gated carbon nanotube as a paradigmatical capacitor system and showed that, for the range of mechanical strain considered, quantum capacitance can be adjusted from very large positive to very large negative values (in the order of plus/minus hundreds of attofarads), compared to the corresponding classical geometric value (0.31035 aF). This finding opens novel avenues in designing quantum capacitance for applications in nanosensors, energy storage, and nanoelectronics.

Correlations between potassium, rubidium and cesium ({sup 133}Cs and {sup 137}Cs) in sporocarps of Suillus variegatus in a Swedish boreal forest

Energy Technology Data Exchange (ETDEWEB)

Vinichuk, M., E-mail: Mykhailo.Vinichuk@slu.s [Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Department of Ecology, Zhytomyr State Technological University, 103 Cherniakhovsky Str., 10005 Zhytomyr (Ukraine); Rosen, K.; Johanson, K.J. [Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Dahlberg, A. [Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences, P.O. Box 7026, 750 07 Uppsala (Sweden)

2011-04-15

An analysis of sporocarps of ectomycorrhizal fungi Suillus variegatus assessed whether cesium ({sup 133}Cs and {sup 137}Cs) uptake was correlated with potassium (K) or rubidium (Rb) uptake. The question was whether intraspecific correlations of Rb, K and {sup 133}Cs mass concentrations with {sup 137}Cs activity concentrations in sporocarps were higher within, rather than among, different fungal species, and if genotypic origin of sporocarps within a population affected uptake and correlation. Sporocarps (n = 51) from a Swedish forest population affected by the fallout after the Chernobyl accident were studied. The concentrations were 31.9 {+-} 6.79 g kg{sup -1} for K (mean {+-} SD, dwt), 0.40 {+-} 0.09 g kg{sup -1} for Rb, 8.7 {+-} 4.36 mg kg{sup -1} for {sup 133}Cs and 63.7 {+-} 24.2 kBq kg{sup -1} for {sup 137}Cs. The mass concentrations of {sup 133}Cs correlated with {sup 137}Cs activity concentrations (r = 0.61). There was correlation between both {sup 133}Cs concentrations (r = 0.75) and {sup 137}Cs activity concentrations (r = 0.44) and Rb, but the {sup 137}Cs/{sup 133}Cs isotopic ratio negatively correlated with Rb concentration. Concentrations of K and Rb were weakly correlated (r = 0.51). The {sup 133}Cs mass concentrations, {sup 137}Cs activity concentrations and {sup 137}Cs/{sup 133}Cs isotopic ratios did not correlate with K concentrations. No differences between, within or, among genotypes in S. variegatus were found. This suggested the relationships between K, Rb, {sup 133}Cs and {sup 137}Cs in sporocarps of S. variegatus is similar to other fungal species. - Highlights: {yields} We studied uptake of Cs ({sup 133}Cs and {sup 137}Cs), K and Rb by Suillus variegates sporocarps. {yields} Genotypic origin of fungus did not affect uptake of studied elements (isotopes). {yields} Genotypic origin did not affect correlation between Cs ({sup 133}Cs and {sup 137}Cs), K and Rb.

Negative quantum capacitance induced by midgap states in single-layer graphene.

Science.gov (United States)

Wang, Lin; Wang, Yang; Chen, Xiaolong; Zhu, Wei; Zhu, Chao; Wu, Zefei; Han, Yu; Zhang, Mingwei; Li, Wei; He, Yuheng; Xiong, Wei; Law, Kam Tuen; Su, Dangsheng; Wang, Ning

2013-01-01

We demonstrate that single-layer graphene (SLG) decorated with a high density of Ag adatoms displays the unconventional phenomenon of negative quantum capacitance. The Ag adatoms act as resonant impurities and form nearly dispersionless resonant impurity bands near the charge neutrality point (CNP). Resonant impurities quench the kinetic energy and drive the electrons to the Coulomb energy dominated regime with negative compressibility. In the absence of a magnetic field, negative quantum capacitance is observed near the CNP. In the quantum Hall regime, negative quantum capacitance behavior at several Landau level positions is displayed, which is associated with the quenching of kinetic energy by the formation of Landau levels. The negative quantum capacitance effect near the CNP is further enhanced in the presence of Landau levels due to the magnetic-field-enhanced Coulomb interactions.

137Cs in northern Adriatic sediments

International Nuclear Information System (INIS)

Barisic, D.; Lulic, S.; Vdovic, N.; Vertacnik, A.; Juracic, M.

1996-01-01

The activity of 137 Cs in shallow northern Adriatic sediments was obtained on the basis of measurement results from 25 sediment box cores, sampled during the Adriatic Scientific COoperation Program (ASCOP) 16 cruise in the summer 1990. 137 Cs was determined in surface sediments (0-3 cm) and 12-15 cm-deep sediment. It was found that the lowest caesium concentrations correspond to sands, which are spread along the Croatian coast. Parallel to the Italian coast, 137 Cs concentrations in pelites are the highest. It seems that the influence of Po River is significant for 137 Cs activities in recent marine sediments along Italian coast south of Po River delta. Significantly higher 137 Cs activities in 0-3 cm sediment layer can be attributed to the deposition caused by Chernobyl accident. (author)

The interfacial capacitance of an oxidised polycrystalline gold electrode in an aqueous HClO4 electrolyte

International Nuclear Information System (INIS)

Grdeń, M.

2013-01-01

The interfacial capacitance of a polycrystalline gold electrode electrochemically oxidised in an aqueous 0.1 M HClO 4 electrolyte has been investigated by means of the electrochemical impedance spectroscopy. From 1.3 to 3 monolayers of Au atoms were oxidised under constant potential conditions and for various oxidation times. The capacitance of the oxidised layers was analysed as a function of the electrode potential and the extent of the surface oxidation. It was found that the interfacial capacitance decreases upon surface oxidation. The components of the interfacial capacitance of the oxidised layer: the double layer capacitance and the capacitance of the oxidised layer; have been separated. The capacitance of the double layer of the oxidised surface was found to be comparable to the capacitance measured for the metallic surface. - Highlights: • The impedance spectra for thin layers of Au oxides/hydroxides were acquired. • Separate determination of the double layer and the oxide capacitances of oxidised Au • The double layer capacitances of oxidised and non-oxidised Au surfaces are comparable

Low Capacitive Inductors for Fast Switching Devices in Active Power Factor Correction Applications

DEFF Research Database (Denmark)

Hernandez Botella, Juan Carlos; Petersen, Lars Press; Andersen, Michael A. E.

2014-01-01

This paper examines different winding strategies for reduced capacitance inductors in active power factor correction circuits (PFC). The effect of the parasitic capacitance is analyzed from an electro magnetic compatibility (EMI) and efficiency point of views. The purpose of this work is to inves......This paper examines different winding strategies for reduced capacitance inductors in active power factor correction circuits (PFC). The effect of the parasitic capacitance is analyzed from an electro magnetic compatibility (EMI) and efficiency point of views. The purpose of this work...... is to investigate different winding approaches and identify suitable solutions for high switching frequency/high speed transition PFC designs. A low parasitic capacitance PCB based inductor design is proposed to address the challenges imposed by high switching frequency PFC Boost converters....

Development of a Capacitive Ice Sensor to Measure Ice Growth in Real Time

Directory of Open Access Journals (Sweden)

Xiang Zhi

2015-03-01

Full Text Available This paper presents the development of the capacitive sensor to measure the growth of ice on a fuel pipe surface in real time. The ice sensor consists of pairs of electrodes to detect the change in capacitance and a thermocouple temperature sensor to examine the ice formation situation. In addition, an environmental chamber was specially designed to control the humidity and temperature to simulate the ice formation conditions. From the humidity, a water film is formed on the ice sensor, which results in an increase in capacitance. Ice nucleation occurs, followed by the rapid formation of frost ice that decreases the capacitance suddenly. The capacitance is saturated. The developed ice sensor explains the ice growth providing information about the icing temperature in real time.

Development of a capacitive ice sensor to measure ice growth in real time.

Science.gov (United States)

Zhi, Xiang; Cho, Hyo Chang; Wang, Bo; Ahn, Cheol Hee; Moon, Hyeong Soon; Go, Jeung Sang

2015-03-19

This paper presents the development of the capacitive sensor to measure the growth of ice on a fuel pipe surface in real time. The ice sensor consists of pairs of electrodes to detect the change in capacitance and a thermocouple temperature sensor to examine the ice formation situation. In addition, an environmental chamber was specially designed to control the humidity and temperature to simulate the ice formation conditions. From the humidity, a water film is formed on the ice sensor, which results in an increase in capacitance. Ice nucleation occurs, followed by the rapid formation of frost ice that decreases the capacitance suddenly. The capacitance is saturated. The developed ice sensor explains the ice growth providing information about the icing temperature in real time.

137Cs metabolism in pregnant women

International Nuclear Information System (INIS)

Melo, D.R.; Lipsztein, J.L.; Oliveira, C.A.N.; Bertelli, L.

2000-01-01

Data from two pregnant women contaminated with 137 Cs, body burdens of 0.2 and 300 MBq, respectively at the time of the Goiania accident, were compared. The first one, with lower body burden was exposed during the fourth month of pregnancy, while the second became pregnant three years and eight months after 137 Cs intake. For the first woman 137 Cs concentrations were equal for the mother, infant and placenta, indicating an easy and homogeneous transport of 137 Cs from mother to foetus. The whole body monitoring data from the second woman, who became pregnant four years after intake, did not show a reduction in biological half-life during the pregnancy. Cs concentration in the mother was found to be 13 times higher than in the infant. One possible reason for this result is that four years after intake, Cs is supposed to be concentrated mainly in skeletal muscle tissue. During the pregnancy the blood flux becomes higher in most of the organs and tissues except brain, liver and skeletal muscle tissue. (author)

Estimation of average burnup of damaged fuels loaded in Fukushima Dai-ichi reactors by using the 134Cs/137Cs ratio method

International Nuclear Information System (INIS)

Endo, T.; Sato, S.; Yamamoto, A.

2012-01-01

Average burnup of damaged fuels loaded in Fukushima Dai-ichi reactors is estimated, using the 134 Cs/ 137 Cs ratio method for measured radioactivities of 134 Cs and 137 Cs in contaminated soils within the range of 100 km from the Fukushima Dai-ichi nuclear power plants. As a result, the measured 134 Cs/ 137 Cs ratio from the contaminated soil is 0.996±0.07 as of March 11, 2011. Based on the 134 Cs/ 137 Cs ratio method, the estimated burnup of damaged fuels is approximately 17.2±1.5 [GWd/tHM]. It is noted that the numerical results of various calculation codes (SRAC2006/PIJ, SCALE6.0/TRITON, and MVP-BURN) are almost the same evaluation values of 134 Cs/ 137 Cs ratio with same evaluated nuclear data library (ENDF-B/VII.0). The void fraction effect in depletion calculation has a major impact on 134 Cs/ 137 Cs ratio compared with the differences between JENDL-4.0 and ENDF-B/VII.0. (authors)

Stray dogs and cats as potential sources of soil contamination with zoonotic parasites.

Science.gov (United States)

Szwabe, Katarzyna; Blaszkowska, Joanna

2017-03-22

The main source of many zoonoses is soil contaminated with feline and canine faeces. Thus, the aim of this study was to estimate the prevalence of intestinal parasites in stray dogs and cats adopted in Lodz shelter (Poland). In total, 163 faecal samples were collected from 95 dogs and 68 cats from 2011 to 2012. The samples were processed by sedimentation techniques using Mini Parasep®SF. Six parasite genera belonging to protozoa, cestoda, and nematoda, were found in dogs, while eight were found in cats. Out of the 163 fecal samples, 37.4% were positive for the presence at least one species of intestinal parasites. The majority of positive dog samples contained eggs from Toxocara and Trichuris genera, and the family Ancylostomatidae, while Toxocara and Taenia eggs, as well as Cystoisospora oocysts, predominated in cat faeces. A significantly higher prevalence of parasites was noted in cats (48.5%) than in dogs (29.5%) (χ2=6.15, P=0.013). The Toxocara genus was the most prevalent parasite in both populations; eggs were found in 27.9% and 16.8% of cats and dogs, respectively. Animals younger than 12 months of age showed higher infection rates with Toxocara, but differences were not statistically significant. The average numbers of Toxocara eggs/gram of faeces in positive puppy and kitten samples were over 5 and 7 times higher than in older dogs and cats, respectively. Mixed infection were found in dogs (5.3%) and cats (8.8%). Cat faeces represent a more important potential source of environmental contamination with zoonotic parasites than dog faeces. Among the detected parasites of stray dogs and cats, Toxocara present an important zoonotic risk for the local human population, especially children.

Waste forms based on Cs-loaded silicotitanates

International Nuclear Information System (INIS)

Balmer, M.L.; Bunker, B.C.

1995-04-01

Silicotitanate ion exchange materials are being considered for removal of radioactive Cs and Sr from tank wastes at the Hanford site. The phase evolution as a function of heat treatment temperature for several sol gel derived compositions within the Cs 2 O-SiO 2 -TiO 2 system was investigated, in order to determine if an adequate waste form can be achieved by direct thermal conversion. The Cs leach rates and Cs loss during heat treatment of select materials were measured. Some compositions which contain large amounts of Ti melt to form a glass with reasonably low aqueous leach rates. A new Cs-silicotitanate material with a structure isomorphous to pollucite was discovered. This material forms at low temperatures (700--800 C) where Cs volatility is negligible. The silicotitanate-pollucite exhibits extremely low leach rates (1.42 g/m 2 day ) at 90 C, and has been identified as a promising waste form for Cs containment

Hybridization of Single Nanocrystals of Cs4PbBr6 and CsPbBr3

OpenAIRE

Weerd, Chris de; Lin, Junhao; Gomez, Leyre; Fujiwara, Yasufumi; Suenaga, Kazutomo; Gregorkiewicz, Tom

2017-01-01

Nanocrystals of all-inorganic cesium lead halide perovskites (CsPbX3, X = Cl, Br, I) feature high absorption and efficient narrow-band emission which renders them promising for future generation of photovoltaic and optoelectronic devices. Colloidal ensembles of these nanocrystals can be conveniently prepared by chemical synthesis. However, in the case of CsPbBr3, its synthesis can also yield nanocrystals of Cs4PbBr6 and the properties of the two are easily confused. Here, we investigate in de...

CMOS capacitive biosensors for highly sensitive biosensing applications.

Science.gov (United States)

Chang, An-Yu; Lu, Michael S-C

2013-01-01

Magnetic microbeads are widely used in biotechnology and biomedical research for manipulation and detection of cells and biomolecules. Most lab-on-chip systems capable of performing manipulation and detection require external instruments to perform one of the functions, leading to increased size and cost. This work aims at developing an integrated platform to perform these two functions by implementing electromagnetic microcoils and capacitive biosensors on a CMOS (complementary metal oxide semiconductor) chip. Compared to most magnetic-type sensors, our detection method requires no externally applied magnetic fields and the associated fabrication is less complicated. In our experiment, microbeads coated with streptavidin were driven to the sensors located in the center of microcoils with functionalized anti-streptavidin antibody. Detection of a single microbead was successfully demonstrated using a capacitance-to-frequency readout. The average capacitance changes for the experimental and control groups were -5.3 fF and -0.2 fF, respectively.

Micromachined capacitive ultrasonic immersion transducer array

Science.gov (United States)

Jin, Xuecheng

Capacitive micromachined ultrasonic transducers (cMUTs) have emerged as an attractive alternative to conventional piezoelectric ultrasonic transducers. They offer performance advantages of wide bandwidth and sensitivity that have heretofore been attainable. In addition, micromachining technology, which has benefited from the fast-growing microelectronics industry, enables cMUT array fabrication and electronics integration. This thesis describes the design and fabrication of micromachined capacitive ultrasonic immersion transducer arrays. The basic transducer electrical equivalent circuit is derived from Mason's theory. The effects of Lamb waves and Stoneley waves on cross coupling and acoustic losses are discussed. Electrical parasitics such as series resistance and shunt capacitance are also included in the model of the transducer. Transducer fabrication technology is systematically studied. Device dimension control in both vertical and horizontal directions, process alternatives and variations in membrane formation, via etch and cavity sealing, and metalization as well as their impact on transducer performance are summarized. Both 64 and 128 element 1-D array transducers are fabricated. Transducers are characterized in terms of electrical input impedance, bandwidth, sensitivity, dynamic range, impulse response and angular response, and their performance is compared with theoretical simulation. Various schemes for cross coupling reduction is analyzed, implemented, and verified with both experiments and theory. Preliminary results of immersion imaging are presented using 64 elements 1-D array transducers for active source imaging.

Energy-Efficient Capacitance-to-Digital Converters for Smart Sensor Applications

KAUST Repository

Alhoshany, Abdulaziz

2017-12-01

One of the key requirements in the design of wireless sensor nodes and miniature biomedical devices is energy efficiency. For a sensor node, which is a sensor and readout circuit, to survive on limited energy sources such as a battery or harvested energy, its energy consumption should be minimized. Capacitive sensors are candidates for use in energy-constrained applications, as they do not consume static power and can be used in a wide range of applications to measure different physical, chemical or biological quantities. However, the energy consumption is dominated by the capacitive interface circuit, i.e. the capacitance-to-digital converter (CDC). Several energy-efficient CDC architectures are introduced in this dissertation to meet the demand for high resolution and energy efficiency in smart capacitive sensors. First, we propose an energy-efficient CDC based on a differential successive-approximation data converter. The proposed differential CDC employs an energy-efficient operational transconductance amplifier (OTA) based on an inverter. A wide capacitance range with fine absolute resolution is implemented in the proposed coarse-fine DAC architecture which saves 89% of silicon area. The proposed CDC achieves an energy efficiency figure-of-merit () of 45.8fJ/step, which is the best reported energy efficiency to date. Second, we propose an energy efficient CDC for high-precision capacitive resolution by using oversampling and noise shaping. The proposed CDC achieves 150 aF absolute resolution and an energy efficiency of 187fJ/conversion-step which outperforms state of the art high-precision differential CDCs. In the third and last part, we propose an in-vitro cancer diagnostic biosensor-CMOS platform for low-power, rapid detection, and low cost. The introduced platform is the first to demonstrate the ability to screen and quantify the spermidine/spermine N1 acetyltransferase (SSAT) enzyme which reveals the presence of early-stage cancer, on the surface of a

Inside-out electrical capacitance tomography

DEFF Research Database (Denmark)

Kjærsgaard-Rasmussen, Jimmy; Meyer, Knud Erik

2011-01-01

In this work we demonstrate the construction of an ‘inside-out’ sensor geometry for electrical capacitance tomography (ECT). The inside-out geometry has the electrodes placed around a tube, as usual, but measuring ‘outwards’. The flow between the electrodes and an outer tube is reconstructed...

Behaviour of 134Cs in the aquatic ecosystems

International Nuclear Information System (INIS)

Xu Yinliang; Chen Chuanqun

1992-07-01

The diminution of 134 Cs in the aquatic phases and the absorption of 134 Cs by aquatic lives observe the exponential expression. i.e. Y Ae be . The relationships between the enrichment factor of 134 Cs(K) and the time(t) in the aquatic lives can be represented by a linear equation, K A + Bt. The value of K in the Alternanthera philoxeroides was about 560. That can be used for monitoring and purifying the water phase contaminated by 134 Cs. Fish can absorb 134 Cs from water phase and store it in liver and kidney. The specific activity of 134 Cs in fish flesh was low but the percentage of radioactivity was high that was about 30% of total radioactivity in the fish. River mud can strongly absorb 134 Cs and reduce the absorption by aquatic lives. It is a good adsorbent and purifying agent with low cost for treatment of 134 Cs. The K + can prevent aquatic lives from absorbing Cs + because of antagonistic function

Triboelectricity in capacitive biopotential measurements.

Science.gov (United States)

Wartzek, Tobias; Lammersen, Thomas; Eilebrecht, Benjamin; Walter, Marian; Leonhardt, Steffen

2011-05-01

Capacitive biopotential measurements suffer from strong motion artifacts, which may result in long time periods during which a reliable measurement is not possible. This study examines contact electrification and triboelectricity as possible reasons for these artifacts and discusses local triboelectric effects on the electrode-body interface as well as global electrostatic effects as common-mode interferences. It will be shown that most probably the triboelectric effects on the electrode-body interface are the main reason for artifacts, and a reduction of artifacts can only be achieved with a proper design of the electrode-body interface. For a deeper understanding of the observed effects, a mathematical model for triboelectric effects in highly isolated capacitive biopotential measurements is presented and verified with experiments. Based on these analyses of the triboelectric effects on the electrode-body interface, different electrode designs are developed and analyzed in order to minimize artifacts due to triboelectricity on the electrode-body interface. © 2011 IEEE

Countering the stray magnetic field of the CUSP trap by using additional coils

CERN Document Server

Thole, Jelle

2016-01-01

The ASACUSA experiment at the Antiproton Decelerator (AD) at CERN tries to measure the Hyperfine Structure (HFS) of Antihydrogen (H ̄) using a Rabi spectroscopy set-up. In measuring this HFS it will yield a very precise test of CPT-symmetry. For this set-up to work a homogeneous magnetic field is needed in the cavity where the Hyperfine transition of H ̄ occurs. Due to the stray fields from the CUSP trap, where H ̄ is produced, additional coils are needed to counter these fields. It is found, using COMSOL simulations, that two coils are suitable for this. Leading to a relative standard deviation of the magnetic field of σB/B = 1.06%.

Nonlinear dynamics of capacitive charging and desalination by porous electrodes

Science.gov (United States)

Biesheuvel, P. M.; Bazant, M. Z.

2010-03-01

The rapid and efficient exchange of ions between porous electrodes and aqueous solutions is important in many applications, such as electrical energy storage by supercapacitors, water desalination and purification by capacitive deionization, and capacitive extraction of renewable energy from a salinity difference. Here, we present a unified mean-field theory for capacitive charging and desalination by ideally polarizable porous electrodes (without Faradaic reactions or specific adsorption of ions) valid in the limit of thin double layers (compared to typical pore dimensions). We illustrate the theory for the case of a dilute, symmetric, binary electrolyte using the Gouy-Chapman-Stern (GCS) model of the double layer, for which simple formulae are available for salt adsorption and capacitive charging of the diffuse part of the double layer. We solve the full GCS mean-field theory numerically for realistic parameters in capacitive deionization, and we derive reduced models for two limiting regimes with different time scales: (i) in the “supercapacitor regime” of small voltages and/or early times, the porous electrode acts like a transmission line, governed by a linear diffusion equation for the electrostatic potential, scaled to the RC time of a single pore, and (ii) in the “desalination regime” of large voltages and long times, the porous electrode slowly absorbs counterions, governed by coupled, nonlinear diffusion equations for the pore-averaged potential and salt concentration.

Quality assessment of MOZAIC and IAGOS capacitive hygrometers: insights from airborne field studies

Directory of Open Access Journals (Sweden)

Patrick Neis

2015-10-01

Full Text Available In 2011, the MOZAIC (Measurement of Ozone by AIRBUS In-Service Aircraft successor programme IAGOS (In-service Aircraft for a Global Observing System started to equip their long-haul passenger aircraft with the modified capacitive hygrometer Vaisala HUMICAP® of type H. The assurance of the data quality and the consistency of the data set during the transition from MOZAIC Capacitive Hygrometers to IAGOS Capacitive Hygrometers were evaluated within the CIRRUS-III and AIRTOSS-ICE field studies. During these performance tests, the capacitive hygrometers were operated aboard a Learjet 35A aircraft together with a closed-cell Lyman-α fluorescence hygrometer, an open-path tunable diode laser (TDL system and a closed-cell, direct TDL absorption hygrometer for water vapour measurement. For MOZAIC-typical operation conditions, the comparison of relative humidity (RH data from the capacitive hygrometers and reference instruments yielded remarkably good agreement with an uncertainty of 5% RH. The temperature dependence of the sensor's response time was derived from the cross-correlation of capacitive hygrometer data and smoothed data from the fast-responding reference instruments. The resulting exponential moving average function could explain the major part of the observed deviations between the capacitive hygrometers and the reference instruments.

New technology of CRDM-CS

International Nuclear Information System (INIS)

Yasushi Nozaki; Hiroyuki Ukon; Toshiaki Matsumura; Yoshihiro Sakurai; Sigenori Hatazawa; Hitoshi Yamagishi; Katsuji Kaneizumi; Hisashi Yasuda

2005-01-01

Control Rod Drive Mechanism Control System (CRDM-CS) for PWR Nuclear Power Plant was developed as a domestic product in 1975 and it has been applied to the commercial power plants. Since then, the CRDM-CS has been continuously improved through applying a double-hold-system, an intensified monitoring system, etc. As the result of these modifications unexpected rod drops have never occurred more than ten years in Japanese PWR plants. The system is still so high reliable, however, the technologies of employed devices are old-fashioned and we face on the difficulty to keep spare-parts these days. On the other hand, there are new movements to seek after the plant life extension of 60 years. These situations require a modernized CRDM-CS to accomplish the reliability in accordance to the plant life extension. to comply the above-mentioned object we developed a new CRDM-CS applied with following technologies; 1) Digitalized logic cabinet, 2) I.G.B.T in the main circuit of power cabinet, 3) Standardized cabinet by employing the unit structure, 4) Unnecessary DC hold power cabinet. These measures can play an important role in cost cutting and space reduction in replacing CRDM-CS. The concepts in developing the new CRDM-CS, the applied technologies to the power cabinet, the system structure and characteristics of the logic cabinet and the outline of verification test and result are discussed in this paper. (authors)

Coefficients of distribution and accumulation of K, Rb, Cs and 137Cs in the intensive poultry breeding cycle

International Nuclear Information System (INIS)

Djuric, G.; Ajdacic, N.; Institut za Nuklearne Nauke Boris Kidric, Belgrade

1984-01-01

The concentration of K,Rb,Cs and the activity level of Cs-137 in samples from the intensive poultry breeding cycle (feed, meat, eggs), under the condition of chronic alimentary contamination is presented. Concentrations of Cs and Rb were determined by non-destructive neutron activation analysis, concentration of K by atomic absorption flame photometry and activity of Cs-137 by gamma spectrometric analysis. On the basis of these results, coefficients of distribution and accumulation were calculated. The distribution coefficients of the analysed stable isotopes in meat have values close to 1, whereas for various parts of egg these coefficients vary between 0.5 and 1.5. Significant differences in Cs-137 distribution in various parts of egg were established. The values of accumulation coefficients indicate that all analysed elements selectively accumulate in the meat of young birds (broilers), and Cs-137 accumulates in the egg white as well. (orig.)

Intermittent-contact scanning capacitance microscopy imaging and modeling for overlay metrology

International Nuclear Information System (INIS)

Mayo, S.; Kopanski, J. J.; Guthrie, W. F.

1998-01-01

Overlay measurements of the relative alignment between sequential layers are one of the most critical issues for integrated circuit (IC) lithography. We have implemented on an AFM platform a new intermittent-contact scanning capacitance microscopy (IC-SCM) mode that is sensitive to the tip proximity to an IC interconnect, thus making it possible to image conductive structures buried under planarized dielectric layers. Such measurements can be used to measure IC metal-to-resist lithography overlay. The AFM conductive cantilever probe oscillating in a vertical plane was driven at frequency ω, below resonance. By measuring the tip-to-sample capacitance, the SCM signal is obtained as the difference in capacitance, ΔC(ω), at the amplitude extremes. Imaging of metallization structures was obtained with a bars-in-bars aluminum structure embedded in a planarized dielectric layer 1 μm thick. We have also modeled, with a two-dimensional (2D) electrostatic field simulator, IC-SCM overlay data of a metallization structure buried under a planarized dielectric having a patterned photoresist layer deposited on it. This structure, which simulates the metal-to-resist overlay between sequential IC levels, allows characterization of the technique sensitivity. The capacitance profile across identical size electrically isolated or grounded metal lines embedded in a dielectric was shown to be different. The floating line shows capacitance enhancement at the line edges, with a minimum at the line center. The grounded line shows a single capacitance maximum located at the line center, with no edge enhancement. For identical line dimensions, the capacitance is significantly larger for grounded lines making them easier to image. A nonlinear regression algorithm was developed to extract line center and overlay parameters with approximately 3 nm resolution at the 95% confidence level, showing the potential of this technique for sub-micrometer critical dimension metrology. Symmetric test

Integrated microelectronic capacitive readout subsystem for lab-on-a-chip applications

International Nuclear Information System (INIS)

Spathis, Christos; Georgakopoulou, Konstantina; Petrellis, Nikos; Efstathiou, Konstantinos; Birbas, Alexios

2014-01-01

A mixed-signal capacitive biosensor readout system is presented with its main readout functionality embedded in an integrated circuit, compatible with complementary metal oxide semiconductor-type biosensors. The system modularity allows its usage as a consumable since it eventually leads to a system-on-chip where sensor and readout circuitry are hosted on the same die. In this work, a constant current source is used for measuring the input capacitance. Compared to most capacitive biosensor readout circuits, this method offers the convenience of adjusting both the range and the resolution, depending on the requirements dictated by the application. The chip consumes less than 5 mW of power and the die area is 0.06 mm 2 . It shows a broad input capacitance range (capable of measuring bio-capacitances from 6 pF to 9.8 nF), configurable resolution (down to 1 fF), robustness to various biological experiments and good linearity. The integrated nature of the readout system is proven to be sufficient both for one-time in situ (consumable-type) bio-measurements and its incorporation into a point-of-care system. (paper)

Fully integrated low-noise readout circuit with automatic offset cancellation loop for capacitive microsensors.

Science.gov (United States)

Song, Haryong; Park, Yunjong; Kim, Hyungseup; Cho, Dong-Il Dan; Ko, Hyoungho

2015-10-14

Capacitive sensing schemes are widely used for various microsensors; however, such microsensors suffer from severe parasitic capacitance problems. This paper presents a fully integrated low-noise readout circuit with automatic offset cancellation loop (AOCL) for capacitive microsensors. The output offsets of the capacitive sensing chain due to the parasitic capacitances and process variations are automatically removed using AOCL. The AOCL generates electrically equivalent offset capacitance and enables charge-domain fine calibration using a 10-bit R-2R digital-to-analog converter, charge-transfer switches, and a charge-storing capacitor. The AOCL cancels the unwanted offset by binary-search algorithm based on 10-bit successive approximation register (SAR) logic. The chip is implemented using 0.18 μm complementary metal-oxide-semiconductor (CMOS) process with an active area of 1.76 mm². The power consumption is 220 μW with 3.3 V supply. The input parasitic capacitances within the range of -250 fF to 250 fF can be cancelled out automatically, and the required calibration time is lower than 10 ms.

Fully Integrated Low-Noise Readout Circuit with Automatic Offset Cancellation Loop for Capacitive Microsensors

Directory of Open Access Journals (Sweden)

Haryong Song

2015-10-01

Full Text Available Capacitive sensing schemes are widely used for various microsensors; however, such microsensors suffer from severe parasitic capacitance problems. This paper presents a fully integrated low-noise readout circuit with automatic offset cancellation loop (AOCL for capacitive microsensors. The output offsets of the capacitive sensing chain due to the parasitic capacitances and process variations are automatically removed using AOCL. The AOCL generates electrically equivalent offset capacitance and enables charge-domain fine calibration using a 10-bit R-2R digital-to-analog converter, charge-transfer switches, and a charge-storing capacitor. The AOCL cancels the unwanted offset by binary-search algorithm based on 10-bit successive approximation register (SAR logic. The chip is implemented using 0.18 μm complementary metal-oxide-semiconductor (CMOS process with an active area of 1.76 mm2. The power consumption is 220 μW with 3.3 V supply. The input parasitic capacitances within the range of −250 fF to 250 fF can be cancelled out automatically, and the required calibration time is lower than 10 ms.

Large Capacitance Measurement by Multiple Uses of MBL Charge Sensor

Science.gov (United States)

Lee, Jung Sook; Chae, Min; Kim, Jung Bog

2010-01-01

A recent article by Morse described interesting electrostatics experiments using an MBL charge sensor. In this application, the charge sensor has a large capacitance compared to the charged test object, so nearly all charges can be transferred to the sensor capacitor from the capacitor to be measured. However, the typical capacitance of commercial…

Using Multiple Paths in NoCs for Guaranteed Resource Allocation and Improved Best Effort Performance in NoCs.

NARCIS (Netherlands)

Ovadia, I.; Ha, Y.; Corporaal, H.

2005-01-01

Networks-on-Chips (NoCs) provide communication platforms to Systems-on-Chips (SoCs). In NoCs, channels are generally shared between traffic flows, resulting in contention. However, certain flows require delivery guarantees. Differentiated quality-of-service (QoS) is achieved by providing guaranteed

Capacitors and Resistance-Capacitance Networks.

Science.gov (United States)

Balabanian, Norman; Root, Augustin A.

This programed textbook was developed under a contract with the United States Office of Education as Number 5 in a series of materials for use in an electrical engineering sequence. It is divided into three parts--(1) capacitors, (2) voltage-current relationships, and (3) simple resistance-capacitance networks. (DH)

Extrinsic and Intrinsic Frequency Dispersion of High-k Materials in Capacitance-Voltage Measurements

Directory of Open Access Journals (Sweden)

S. Taylor

2012-06-01

Full Text Available In capacitance-voltage (C-V measurements, frequency dispersion in high-k dielectrics is often observed. The frequency dependence of the dielectric constant (k-value, that is the intrinsic frequency dispersion, could not be assessed before suppressing the effects of extrinsic frequency dispersion, such as the effects of the lossy interfacial layer (between the high-k thin film and silicon substrate and the parasitic effects. The effect of the lossy interfacial layer on frequency dispersion was investigated and modeled based on a dual frequency technique. The significance of parasitic effects (including series resistance and the back metal contact of the metal-oxide-semiconductor (MOS capacitor on frequency dispersion was also studied. The effect of surface roughness on frequency dispersion is also discussed. After taking extrinsic frequency dispersion into account, the relaxation behavior can be modeled using the Curie-von Schweidler (CS law, the Kohlrausch-Williams-Watts (KWW relationship and the Havriliak-Negami (HN relationship. Dielectric relaxation mechanisms are also discussed.

Prevalence and Potential Risk Factors for Bartonella Infection in Tunisian Stray Dogs.

Science.gov (United States)

Belkhiria, Jaber; Chomel, Bruno B; Ben Hamida, Taoufik; Kasten, Rickie W; Stuckey, Matthew J; Fleischman, Drew A; Christopher, Mary M; Boulouis, Henri-Jean; Farver, Thomas B

2017-06-01

Bartonellae are blood-borne and vector-transmitted pathogens, some are zoonotic, which have been reported in several Mediterranean countries. Transmission from dogs to humans is suspected, but has not been clearly demonstrated. Our objectives were to determine the seroprevalence of Bartonella henselae, Bartonella vinsonii subsp. berkhoffii, Bartonella clarridgeiae, and Bartonella bovis (as a proxy for Candidatus Bartonella merieuxii) in stray dogs from Tunisia, identify the Bartonella species infecting the dogs and evaluate potential risk factors for canine infection. Blood samples were collected between January and November 2013 from 149 dogs in 10 Tunisian governorates covering several climatic zones. Dog-specific and geographic variables were analyzed as potential risk factors for Bartonella spp. seropositivity and PCR-positivity. DNA was extracted from the blood of all dogs and tested by PCR for Bartonella, targeting the ftsZ and rpoB genes. Partial sequencing was performed on PCR-positive dogs. Twenty-nine dogs (19.5%, 95% confidence interval: 14-27.4) were seropositive for one or more Bartonella species, including 17 (11.4%) for B. vinsonii subsp. berkhoffii, 14 (9.4%) for B. henselae, 13 (8.4%) for B. clarridgeiae, and 7 (4.7%) for B. bovis. Statistical analysis revealed a few potential risk factors, mainly dog's age and breed, latitude and average winter temperature. Twenty-two (14.8%) dogs, including 8 of the 29 seropositive dogs, were PCR-positive for Bartonella based on the ftsZ gene, with 18 (81.8%) of these 22 dogs also positive for the rpoB gene. Partial sequencing showed that all PCR-positive dogs were infected with Candidatus B. merieuxii. Dogs from arid regions and regions with cold average winter temperatures were less likely to be PCR-positive than dogs from other climatic zones. The widespread presence of Bartonella spp. infection in Tunisian dogs suggests a role for stray dogs as potential reservoirs of Bartonella species in Tunisia.

A new normalization method based on electrical field lines for electrical capacitance tomography

International Nuclear Information System (INIS)

Zhang, L F; Wang, H X

2009-01-01

Electrical capacitance tomography (ECT) is considered to be one of the most promising process tomography techniques. The image reconstruction for ECT is an inverse problem to find the spatially distributed permittivities in a pipe. Usually, the capacitance measurements obtained from the ECT system are normalized at the high and low permittivity for image reconstruction. The parallel normalization model is commonly used during the normalization process, which assumes the distribution of materials in parallel. Thus, the normalized capacitance is a linear function of measured capacitance. A recently used model is a series normalization model which results in the normalized capacitance as a nonlinear function of measured capacitance. The newest presented model is based on electrical field centre lines (EFCL), and is a mixture of two normalization models. The multi-threshold method of this model is presented in this paper. The sensitivity matrices based on different normalization models were obtained, and image reconstruction was carried out accordingly. Simulation results indicate that reconstructed images with higher quality can be obtained based on the presented model

Effect of hysteretic and non-hysteretic negative capacitance on tunnel FETs DC performance

Science.gov (United States)

Saeidi, Ali; Jazaeri, Farzan; Stolichnov, Igor; Luong, Gia V.; Zhao, Qing-Tai; Mantl, Siegfried; Ionescu, Adrian M.

2018-03-01

This work experimentally demonstrates that the negative capacitance effect can be used to significantly improve the key figures of merit of tunnel field effect transistor (FET) switches. In the proposed approach, a matching condition is fulfilled between a trained-polycrystalline PZT capacitor and the tunnel FET (TFET) gate capacitance fabricated on a strained silicon-nanowire technology. We report a non-hysteretic switch configuration by combining a homojunction TFET and a negative capacitance effect booster, suitable for logic applications, for which the on-current is increased by a factor of 100, the transconductance by 2 orders of magnitude, and the low swing region is extended. The operation of a hysteretic negative capacitance TFET, when the matching condition for the negative capacitance is fulfilled only in a limited region of operation, is also reported and discussed. In this late case, a limited improvement in the device performance is observed. Overall, the paper demonstrates the main beneficial effects of negative capacitance on TFETs are the overdrive and transconductance amplification, which exactly address the most limiting performances of current TFETs.

Large area, low capacitance Si(Li) detectors for high rate x-ray applications

International Nuclear Information System (INIS)

Rossington, C.S.; Fine, P.M.; Madden, N.W.

1992-10-01

Large area, single-element Si(Li) detectors have been fabricated using a novel geometry which yields detectors with reduced capacitance and hence reduced noise at short amplifier pulse-processing times. A typical device employing the new geometry with a thickness of 6 mm and an active area of 175 mm 2 has a capacitance of only 0.5 pf, compared to 2.9 pf for a conventional planar device with equivalent dimensions. These new low capacitance detectors, used in conjunction with low capacitance field effect transistors, will result in x-ray spectrometers capable of operating at very high count rates while still maintaining excellent energy resolution. The spectral response of the low capacitance detectors to a wide range of x-ray energies at 80 K is comparable to typical state-of-the-art conventional Si(Li) devices. In addition to their low capacitance, the new devices offer other advantages over conventional detectors. Detector fabrication procedures, I-V and C-V characteristics, noise performance, and spectral response to 2-60 keV x-rays are described

Modeling radionuclide Cs and C dynamics in an artificial forest ecosystem in Japan -FoRothCs ver1.0-

Directory of Open Access Journals (Sweden)

Kazuya eNishina

2015-09-01

Full Text Available Predicting the environmental fate of Cs radionuclides in forest ecosystems is important for the effective management and assessment of radioactively contaminated forest areas. A large proportion of the radioactively contaminated areas in Japan consist of forest ecosystems, and most of these areas are artificial forests that are used for timber production (e.g., Japanese cedar (Cryptomeria japonica and red pine (Pinus densiflora. Determining the long-term redistribution of 137Cs in forest ecosystems is important for estimating human doses and understanding the ecological impacts and challenges associated with managing contaminated forests. To facilitate the management and 137Cs decontamination of these forests, we developed a new open-source 137Cs cycling model, ForRothCs, that considers C cycling within forests, as well as biomass production and soil decomposition processes. For the 137Cs inventory, this model estimates the dynamics (Bq m−2 and activity (Bq kg−2 of 137Cs on a decadal time scale, primarily in the leaves, branches, stems, litter layer, and the soil. This model is based on the biomass production and the dynamics of the C cycle models. We tested the model by considering a simple scenario of forest management, i.e., thinning and harvesting, for the first five years following a fallout event. The results showed that these activities have a limited impact on the 137Cs inventory due to the rapid migration of 137Cs from vegetation to soil. Our projections also showed the examined forest management practices resulted in reduced litterfall, which in turn reduced C input to the forest floor and increased the concentration of 137Cs in the litterfall and soil organic layer. Although further validation of the ForRothCs model is required using field observation data, the model can be used to evaluate long-term 137Cs dynamics associated with commonly used forest and decontamination management scenarios.

Capacitance enhancement via electrode patterning

International Nuclear Information System (INIS)

Ho, Tuan A.; Striolo, Alberto

2013-01-01

The necessity of increasing the energy density in electric double layer capacitors to meet current demand is fueling fundamental and applied research alike. We report here molecular dynamics simulation results for aqueous electrolytes near model electrodes. Particular focus is on the effect of electrode patterning on the structure of interfacial electrolytes, and on the potential drop between the solid electrodes and the bulk electrolytes. The latter is estimated by numerically integrating the Poisson equation using the charge densities due to water and ions accumulated near the interface as input. We considered uniform and patterned electrodes, both positively and negatively charged. The uniformly charged electrodes are modeled as graphite. The patterned ones are obtained by removing carbon atoms from the top-most graphene layer, yielding nanoscopic squares and stripes patterns. For simplicity, the patterned electrodes are effectively simulated as insulators (the charge remains localized on the top-most layer of carbon atoms). Our simulations show that the patterns alter the structure of water and the accumulation of ions at the liquid-solid interfaces. Using aqueous NaCl solutions, we found that while the capacitance calculated for three positively charged electrodes did not change much, that calculated for the negatively charged electrodes significantly increased upon patterning. We find that both water structure and orientation, as well as ion accumulation affect the capacitance. As electrode patterning affects differently water structure and ion accumulation, it might be possible to observe ion-specific effects. These results could be useful for advancing our understanding of electric double layer capacitors, capacitive desalination processes, as well as of fundamental interfacial electrolytes properties

Capacitive Cells for Dielectric Constant Measurement

Science.gov (United States)

Aguilar, Horacio Munguía; Maldonado, Rigoberto Franco

2015-01-01

A simple capacitive cell for dielectric constant measurement in liquids is presented. As an illustrative application, the cell is used for measuring the degradation of overheated edible oil through the evaluation of their dielectric constant.

Capacitive sensing of droplets for microfluidic devices based on thermocapillary actuation

NARCIS (Netherlands)

Chen, J.-Z.; Darhuber, A.A.; Troian, S.M.; Wagner, S.

2004-01-01

The design and performance of a miniaturized coplanar capacitive sensor is presented whose electrode arrays can also function as resistive microheaters for thermocapillary actuation of liquid films and droplets. Optimal compromise between large capacitive signal and high spatial resolution is

Luminescent CsPbI.sub.3./sub. and Cs.sub.4./sub.PbI.sub.6./sub. aggregates in annealed CsI:Pb crystals

Czech Academy of Sciences Publication Activity Database

Babin, V.; Fabeni, P.; Nikl, Martin; Nitsch, Karel; Pazzi, G.P.; Zazubovich, S.

2001-01-01

Roč. 226, č. 2 (2001), s. 419-428 ISSN 0370-1972 Institutional research plan: CEZ:AV0Z1010914 Keywords : CsPbI 3 * Cs 4 PbI 6 * nanoaggregates * luminescence Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.873, year: 2001

Cs2UPd3Se6

Directory of Open Access Journals (Sweden)

George N. Oh

2011-02-01

Full Text Available Dicaesium uranium(IV tripalladium(II hexaselenide, Cs2UPd3Se6, crystallizes in the space group Fmmm in the Ba2NaCu3O6 structure type. The asymmetric unit comprises the following atoms with site symmetries as shown: U1 (mm2, Cs1 (222, Cs2 (m2m, Pd1 (.m., Pd2 (2mm, Se1 (m.., and Se2 (1. This layered structure contains six edge-sharing square-planar [PdSe4] units that form a hexagon. These, in turn, edge-share with [USe6] trigonal–prismatic units, forming an extended layer parallel to (010. The layers are stacked along [010]. They are staggered, and are separated by the Cs atoms. The Cs atoms are either coordinated in a square antiprism of Se atoms or are ten-coordinate, with one square face and the opposite face hexagonal.

A Flexible Capacitive Sensor with Encapsulated Liquids as Dielectrics

Directory of Open Access Journals (Sweden)

Yasunari Hotta

2012-03-01

Full Text Available Flexible and high-sensitive capacitive sensors are demanded to detect pressure distribution and/or tactile information on a curved surface, hence, wide varieties of polymer-based flexible MEMS sensors have been developed. High-sensitivity may be achieved by increasing the capacitance of the sensor using solid dielectric material while it deteriorates the flexibility. Using air as the dielectric, to maintain the flexibility, sacrifices the sensor sensitivity. In this paper, we demonstrate flexible and highly sensitive capacitive sensor arrays that encapsulate highly dielectric liquids as the dielectric. Deionized water and glycerin, which have relative dielectric constants of approximately 80 and 47, respectively, could increase the capacitance of the sensor when used as the dielectric while maintaining flexibility of the sensor with electrodes patterned on flexible polymer substrates. A reservoir of liquids between the electrodes was designed to have a leak path, which allows the sensor to deform despite of the incompressibility of the encapsulated liquids. The proposed sensor was microfabricated and demonstrated successfully to have a five times greater sensitivity than sensors that use air as the dielectric.

Probing 2D black phosphorus by quantum capacitance measurements

International Nuclear Information System (INIS)

Kuiri, Manabendra; Kumar, Chandan; Chakraborty, Biswanath; Gupta, Satyendra N; Naik, Mit H; Jain, Manish; Sood, A K; Das, Anindya

2015-01-01

Two-dimensional materials and their heterostructures have emerged as a new class of materials, not only for fundamental physics but also for electronic and optoelectronic applications. Black phosphorus (BP) is a relatively new addition to this class of materials. Its strong in-plane anisotropy makes BP a unique material for making conceptually new types of electronic devices. However, the global density of states (DOS) of BP in device geometry has not been measured experimentally. Here, we report the quantum capacitance measurements together with the conductance measurements on an hBN-protected few-layer BP (∼six layers) in a dual-gated field effect transistor (FET) geometry. The measured DOS from our quantum capacitance is compared with density functional theory (DFT). Our results reveal that the transport gap for quantum capacitance is smaller than that in conductance measurements due to the presence of localized states near the band edge. The presence of localized states is confirmed by the variable range hopping seen in our temperature dependence conductivity. A large asymmetry is observed between the electron and hole side. This asymmetric nature is attributed to the anisotropic band dispersion of BP. Our measurements establish the uniqueness of quantum capacitance in probing the localized states near the band edge, hitherto not seen in conductance measurements. (paper)

A Micro Dynamically Tuned Gyroscope with Adjustable Static Capacitance

Directory of Open Access Journals (Sweden)

Lun Kong

2013-02-01

Full Text Available This paper presents a novel micro dynamically tuned gyroscope (MDTG with adjustable static capacitance. First, the principle of MDTG is theoretically analyzed. Next, some simulations under the optimized structure parameters are given as a reference for the mask design of the rotor wafer and electrode plates. As two key components, the process flows of the rotor wafer and electrode plates are described in detail. All the scanning electron microscopy (SEM photos show that the fabrication process is effective and optimized. Then, an assembly model is designed for the static capacitance adjustable MDTG, whose static capacitance can be changed by rotating the lower electrode plate support and substituting gasket rings of different thicknesses. Thus, the scale factor is easily changeable. Afterwards, the digitalized closed-loop measurement circuit is simulated. The discrete correction and decoupling modules are designed to make the closed-loop stable and cross-coupling effect small. The dual axis closed-loop system bandwidths can reach more than 60 Hz and the dual axis scale factors are completely symmetrical. All the simulation results demonstrate the proposed fabrication of the MDTG can meet the application requirements. Finally, the paper presents the test results of static and dynamic capacitance values which are consistent with the simulation values.

Properties of Cs-intercalated single wall carbon nanotubes investigated by 133Cs Nuclear Magnetic resonance

KAUST Repository

Schmid, Marc R.; Mahfouz, Remi; Bouhrara, Mohamed; Saih, Youssef; Mehring, Michael; Basset, Jean-Marie; Goze-Bac, Christophe; Abou-Hamad, Edy

2012-01-01

present within the carbon nanotube bundles. At high concentrations, the Cs (β)+ ions seem to occupy well defined positions relative to the carbon lattice. As a matter of fact, the Korringa relaxation behavior suggests a strong hyperfine coupling between Cs

Fabrication of a printed capacitive air-gap touch sensor

Science.gov (United States)

Lee, Sang Hoon; Seo, Hwiwon; Lee, Sangyoon

2018-05-01

Unlike lithography-based processes, printed electronics does not require etching, which makes it difficult to fabricate electronic devices with an air gap. In this study, we propose a method to fabricate capacitive air-gap touch sensors via printing and coating. First, the bottom electrode was fabricated on a flexible poly(ethylene terephthalate) (PET) substrate using roll-to-roll gravure printing with silver ink. Then poly(dimethylsiloxane) (PDMS) was spin coated to form a sacrificial layer. The top electrode was fabricated on the sacrificial layer by spin coating with a stretchable silver ink. The sensor samples were then put in a tetrabutylammonium (TBAF) bath to generate the air gap by removing the sacrificial layer. The capacitance of the samples was measured for verification, and the results show that the capacitance increases in proportion to the applied force from 0 to 2.5 N.

A microcontroller-based interface circuit for lossy capacitive sensors

International Nuclear Information System (INIS)

Reverter, Ferran; Casas, Òscar

2010-01-01

This paper introduces and analyses a low-cost microcontroller-based interface circuit for lossy capacitive sensors, i.e. sensors whose parasitic conductance (G x ) is not negligible. Such a circuit relies on a previous circuit also proposed by the authors, in which the sensor is directly connected to a microcontroller without using either a signal conditioner or an analogue-to-digital converter in the signal path. The novel circuit uses the same hardware, but it performs an additional measurement and executes a new calibration technique. As a result, the sensitivity of the circuit to G x decreases significantly (a factor higher than ten), but not completely due to the input capacitances of the port pins of the microcontroller. Experimental results show a relative error in the capacitance measurement below 1% for G x x ) shows the effectiveness of the circuit

A high-power spatial filter for Thomson scattering stray light reduction

Science.gov (United States)

Levesque, J. P.; Litzner, K. D.; Mauel, M. E.; Maurer, D. A.; Navratil, G. A.; Pedersen, T. S.

2011-03-01

The Thomson scattering diagnostic on the High Beta Tokamak-Extended Pulse (HBT-EP) is routinely used to measure electron temperature and density during plasma discharges. Avalanche photodiodes in a five-channel interference filter polychromator measure scattered light from a 6 ns, 800 mJ, 1064 nm Nd:YAG laser pulse. A low cost, high-power spatial filter was designed, tested, and added to the laser beamline in order to reduce stray laser light to levels which are acceptable for accurate Rayleigh calibration. A detailed analysis of the spatial filter design and performance is given. The spatial filter can be easily implemented in an existing Thomson scattering system without the need to disturb the vacuum chamber or significantly change the beamline. Although apertures in the spatial filter suffer substantial damage from the focused beam, with proper design they can last long enough to permit absolute calibration.

Potential value of Cs-137 capsules

Energy Technology Data Exchange (ETDEWEB)

Bloomster, C.H.; Brown, D.R.; Bruno, G.A.; Hazelton, R.F.; Hendrickson, P.L.; Lezberg, A.J.; Tingey, G.L.; Wilfert, G.L.

1985-04-01

We determined the value of Cs-137 compared to Co-60 as a source for the irradiation of fruit (apples and cherries), pork and medical supplies. Cs-137, in the WESF capsule form, had a value of approximately $0.40/Ci as a substitute for Co-60 priced at approximately $1.00/Ci. The comparison was based on the available curies emitted from the surface of each capsule. We developed preliminary designs for fourteen irradiation facilities; seven were based on Co-60 and seven were based on Cs-137. These designs provided the basis for estimating capital and operating costs which, in turn, provided the basis for determining the value of Cs-137 relative to Co-60 in these applications. We evaluated the effect of the size of the irradiation facility on the value of Cs-137. The cost of irradiation is low compared to the value of the product. Irradiation of apples for disinfestation costs $.01 to .02 per pound. Irradiation for trichina-safe pork costs $.02 per pound. Irradiation of medical supplies for sterilization costs $.07 to .12 per pound. The cost of the irradiation source, either Co-60 or Cs-137, contributed only a minor amount to the total cost of irradiation, about 5% for the fruit and hog cases and about 20% for the medical supply cases. We analyzed the sensitivity of the irradiation costs and Cs-137 value to several key assumptions.

Potential value of Cs-137 capsules

International Nuclear Information System (INIS)

Bloomster, C.H.; Brown, D.R.; Bruno, G.A.; Hazelton, R.F.; Hendrickson, P.L.; Lezberg, A.J.; Tingey, G.L.; Wilfert, G.L.

1985-04-01

We determined the value of Cs-137 compared to Co-60 as a source for the irradiation of fruit (apples and cherries), pork and medical supplies. Cs-137, in the WESF capsule form, had a value of approximately $0.40/Ci as a substitute for Co-60 priced at approximately $1.00/Ci. The comparison was based on the available curies emitted from the surface of each capsule. We developed preliminary designs for fourteen irradiation facilities; seven were based on Co-60 and seven were based on Cs-137. These designs provided the basis for estimating capital and operating costs which, in turn, provided the basis for determining the value of Cs-137 relative to Co-60 in these applications. We evaluated the effect of the size of the irradiation facility on the value of Cs-137. The cost of irradiation is low compared to the value of the product. Irradiation of apples for disinfestation costs $.01 to .02 per pound. Irradiation for trichina-safe pork costs $.02 per pound. Irradiation of medical supplies for sterilization costs $.07 to .12 per pound. The cost of the irradiation source, either Co-60 or Cs-137, contributed only a minor amount to the total cost of irradiation, about 5% for the fruit and hog cases and about 20% for the medical supply cases. We analyzed the sensitivity of the irradiation costs and Cs-137 value to several key assumptions

Conjugate Image Theory Applied on Capacitive Wireless Power Transfer

OpenAIRE

Ben Minnaert; Nobby Stevens

2017-01-01

Wireless power transfer using a magnetic field through inductive coupling is steadily entering the market in a broad range of applications. However, for certain applications, capacitive wireless power transfer using electric coupling might be preferable. In order to obtain a maximum power transfer efficiency, an optimal compensation network must be designed at the input and output ports of the capacitive wireless link. In this work, the conjugate image theory is applied to determine this opti...

Structural, electronic properties, and quantum capacitance of B, N and P-doped armchair carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Mousavi-Khoshdel, S. Morteza, E-mail: mmousavi@iust.ac.ir [Department of Chemistry, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Jahanbakhsh-bonab, Parisa [Department of Chemistry, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Targholi, Ehsan [Young Researchers and Elite Club, Abhar Branch, Islamic Azad University, Abhar (Iran, Islamic Republic of)

2016-10-07

Using DFT calculations, we study the structural parameters, electronic properties and quantum capacitance of N, B, and P-doped armchair carbon nanotubes (CNTs). Fermi level shifts towards conduction band and valence band in N- and B-doped CNTs, respectively. While in the case of P atom, despite having an extra valence electron than carbon, there is no shift in Fermi level. The results revealed from a symmetric capacitance enhancement in P-doped CNT and an asymmetric capacitance enhancement in B and N-doped CNTs. The greatest amount of quantum capacitance of N-doped (6, 6) CNT could be achieved at the concentration range of 0.1–0.15. - Highlights: • Exploration of variation in quantum capacitance of CNTs through doping N, B and P atoms. • Quantum capacitance of CNTs is sensitive to impurities entered in carbon nanotubes. • Maximum quantum capacitance of N-doped CNTs is achieved at the concentration range of 0.1–0.15.

Water culture of the rice containing Cs-137

International Nuclear Information System (INIS)

Choi, Yong Ho; Keum, Dong Kwon; Lim, Kwang Muk; Jun, In; Park, Doo Won

2008-10-01

Pot experiments were carried out in a greenhouse in order to produce Cs-137-containing rice seeds as a source material for use in manufacturing reference rice samples of a high Cs-137 activity. Two kinds of soil were used and two pots were prepared for each kind of soil. Rice plants were water-cultured in the pots and Cs-137 was applied to the surface water to induce a Cs-137 contamination of rice seeds via a plant uptake of Cs-137. Mature rice plants were harvested and Cs-137-containing rice seeds were obtained after some treatment of the harvested plants. These produced rice seeds are going to be provided for the KRISS so as to be used in manufacturing reference rice samples for Cs-137

Thermal, conductivity, NMR, and Raman spectroscopic measurements and phase diagram of the Cs2S2O7-CsHSO4 system

DEFF Research Database (Denmark)

Rasmussen, Søren Birk; Hama, Hind; Lapina, Olga

2003-01-01

The conductivity of the binary system CS2S2O7-CsHSO4 has been measured at 20 different molten compositions in the full composition range and in the temperature range 430-750 K. From the obtained liquidus-solidus phase transition temperatures, the phase diagram has been constructed. It is of the s......The conductivity of the binary system CS2S2O7-CsHSO4 has been measured at 20 different molten compositions in the full composition range and in the temperature range 430-750 K. From the obtained liquidus-solidus phase transition temperatures, the phase diagram has been constructed...... from the NMR measurements on CsHSO4, CS2S2O7, and Cs2S2O7-CsHSO4 mixtures. For 11 selected compositions covering the entire composition range of the CS2S2O7-CsHSO4 binary system, the conductivity of the molten state has been expressed by equations of the form k(X) = A(X) + B(X)(T - T-m) + C(X)(T - T...

A report on the alimentary canal helminthic infestation of stray and pet dogs in Tabriz

Directory of Open Access Journals (Sweden)

Y Gharedaghi

2008-08-01

Full Text Available From September to December 2007, fecal specimens of 100 stray and pet dogs in Tabriz were examined by saturated salt flotation and Telmann sedimentation methods to determine the prevalence of gastrointestinal helminth infestation. Helminth infestation was encountered in 31 (31% of the fecal samples examined. The eggs of two different cestodes and three different nematodes were identified in the contaminated fecal samples. The helminth eggs found were identified as Taenia hydatigena (4%, Dipylidium caninum (6%, Toxocara canis (10%, Ancylostoma caninum (6% and Trichuris vulpis (5%. No trematoda eggs and nematode larvae were found in this study.

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.

Determination of /sup 131/I, /sup 134/Cs, /sup 137/Cs in grass and cheese after Chernobyl accident in Austria

Energy Technology Data Exchange (ETDEWEB)

Teherani, D K

1987-09-14

Various samples from Styria (grass) and Salzburg (cheese) were analyzed for /sup 131/I, /sup 134/Cs and /sup 137/Cs concentration during April - July 1986 by ..gamma..-ray spectroscopy. The concentrations are reported in nCi kg/sup -1/ wet weight. The values found for /sup 131/I were 0.2-17.2 (grass), 0.1-0.5 (cheese), for /sup 134/Cs 1.1-6.2 (grass), 0.2-1.3 (cheese), for /sup 137/Cs 1.6-15.7 (grass), 0.3-2.2 (cheese). While radioactivity of /sup 131/I, /sup 134/Cs and /sup 137/Cs in cheese samples increased from May to June, it decreased in grass samples from May to July. (author) 5 refs

Capacitive Sensors for Feedback Control of Microfluidic Devices

Science.gov (United States)

Chen, J. Z.; Darhuber, A. A.; Troian, S. M.; Wagner, S.

2003-11-01

Automation of microfluidic devices based on thermocapillary flow [1] requires feedback control and detection techniques for monitoring the location, and ideally also composition and volume of liquid droplets. For this purpose we have developed a co-planar capacitance technique with a sensitivity of 0.07 pF at a frequency of 370 kHz. The variation in capacitance due to the presence of a droplet is monitored by the output frequency of an RC relaxation oscillator consisting of two inverters, one resistor and one capacitor. We discuss the performance of this coplanar sensor as a function of the electrode dimensions and geometry. These geometric variables determine the electric field penetration depth within the liquid, which in our studies ranged from 30 to 450 microns. Numerical solutions for the capacitance corresponding to the exact fabricated geometry agree very well with experimental data. An approximate analytic solution, which ignores fringe field effects, provides a simple but excellent guide for design development. [1] A. A. Darhuber et al., Appl. Phys. Lett. 82, 657 (2003).

A branch-and-cut-and-price algorithm for the mixed capacitated general routing problem

DEFF Research Database (Denmark)

Bach, Lukas; Wøhlk, Sanne; Lysgaard, Jens

2016-01-01

In this paper, we consider the Mixed Capacitated General Routing Problem which is a combination of the Capacitated Vehicle Routing Problem and the Capacitated Arc Routing Problem. The problem is also known as the Node, Edge, and Arc Routing Problem. We propose a Branch-and-Cut-and-Price algorithm...

Capacitive properties of polypyrrole/activated carbon composite

Directory of Open Access Journals (Sweden)

Porjazoska-Kujundziski Aleksandra

2014-01-01

Full Text Available Electrochemical synthesis of polypyrrole (PPy and polypyrrole / activated carbon (PPy / AC - composite films, with a thickness between 0.5 and 15 μm were performed in a three electrode cell containing 0.1 mol dm-3 Py, 0.5 mol dm-3 NaClO4 dissolved in ACN, and dispersed particles of AC (30 g dm-3. Electrochemical characterization of PPy and PPy / AC composites was performed using cyclic voltammetry (CV and electrochemical impedance spectroscopy (EIS techniques. The linear dependences of the capacitance (qC, redox capacitance (qred, and limiting capacitance (CL of PPy and PPy / AC - composite films on their thickness (L, obtained by electrochemical and impedance analysis, indicate a nearly homogeneous distribution of the incorporated AC particles in the composite films (correlation coefficient between 0.991 and 0.998. The significant enhancement of qC, qred, and CL, was observed for composite films (for ∼40 ± 5% in respect to that of the “pure” PPy. The decreased values of a volume resistivity in the reduced state of the composite film, ρ = 1.3 ⋅ 106 Ω cm (for L = 7.5 μm, for two orders of magnitude, compared to that of PPy - film with the same thickness, ρ ∼ 108 Ω cm, was also noticed.

Calculation of inelastic cross sections for H+ + Cs → H(n=2) + Cs+

International Nuclear Information System (INIS)

Valance, A.; Spiess, G.

1975-01-01

The cross sections for the processes H + +Cs → H(2p and 2s) +Cs + were calculated in the center of mass energy range 250--2400 eV using a simple pseudopotential formalism for the potential curves and coupling matrix elements and a perturbed stationary state (pss) formulation for the calculation of the cross sections. The results are found to be in reasonable agreement with experiment. (auth)

Flexible PVDF ferroelectric capacitive temperature sensor

KAUST Repository

Khan, Naveed; Omran, Hesham; Yao, Yingbang; Salama, Khaled N.

2015-01-01

sensitivity of 16pF/°C. The linearity measurement of the capacitance-temperature relation shows less than 0.7°C error from a best fit straight line. An LC oscillator based temperature sensor is demonstrated based on this capacitor.

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.

Capacitive Feedthroughs for Medical Implants.

Science.gov (United States)

Grob, Sven; Tass, Peter A; Hauptmann, Christian

2016-01-01

Important technological advances in the last decades paved the road to a great success story for electrically stimulating medical implants, including cochlear implants or implants for deep brain stimulation. However, there are still many challenges in reducing side effects and improving functionality and comfort for the patient. Two of the main challenges are the wish for smaller implants on one hand, and the demand for more stimulation channels on the other hand. But these two aims lead to a conflict of interests. This paper presents a novel design for an electrical feedthrough, the so called capacitive feedthrough, which allows both reducing the size, and increasing the number of included channels. Capacitive feedthroughs combine the functionality of a coupling capacitor and an electrical feedthrough within one and the same structure. The paper also discusses the progress and the challenges of the first produced demonstrators. The concept bears a high potential in improving current feedthrough technology, and could be applied on all kinds of electrical medical implants, even if its implementation might be challenging.

A Possible Minimum Toy Model with Negative Differential Capacitance for Self-sustained Current Oscillation

International Nuclear Information System (INIS)

Xiong Gang; Sun Zhouzhou; Wang Xiangrong

2007-01-01

We generalize a simple model for superlattices to include the effect of differential capacitance. It is shown that the model always has a stable steady-state solution (SSS) if all differential capacitances are positive. On the other hand, when negative differential capacitance is included, the model can have no stable SSS and be in a self-sustained current oscillation behavior. Therefore, we find a possible minimum toy model with both negative differential resistance and negative differential capacitance which can include the phenomena of both self-sustained current oscillation and I-V oscillation of stable SSSs.

Influence of water management and fertilizer application on "1"3"7Cs and "1"3"3Cs uptake in paddy rice fields

International Nuclear Information System (INIS)

Wakabayashi, Shokichi; Itoh, Sumio; Kihou, Nobuharu; Matsunami, Hisaya; Hachinohe, Mayumi; Hamamatsu, Shioka; Takahashi, Shigeru

2016-01-01

Cesium-137 derived from the Tokyo Electric Power Company's Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident contaminated large areas of agricultural land in Eastern Japan. Previous studies before the accident have indicated that flooding enhances radiocesium uptake in rice fields. We investigated the influence of water management in combination with fertilizers on "1"3"7Cs concentrations in rice plants at two fields in southern Ibaraki Prefecture. Stable Cs ("1"3"3Cs) in the plants was also determined as an analogue for predicting "1"3"7Cs behavior after long-term aging of soil "1"3"7Cs. The experimental periods comprised 3 y starting from 2012 in one field, and 2 y from 2013 in another field. These fields were divided into three water management sections: a long-flooding section without midsummer drainage, and medial-flooding, and short-flooding sections with one- or two-week midsummer drainage and earlier end of flooding than the long-flooding section. Six or four types of fertilizer subsections (most differing only in potassium application) were nested in each water management section. Generally, the long-flooding treatment led to higher "1"3"7Cs and "1"3"3Cs concentrations in both straw and brown rice than medial- and short-flooding treatments, although there were some notable exceptions in the first experimental year at each site. Effects of differing potassium fertilizer treatments were cumulative; the effects on "1"3"7Cs and "1"3"3Cs concentrations in rice plants were not obvious in 2012 and 2013, but in 2014, these concentrations were highest where potassium fertilizer had been absent and lowest where basal dressings of K had been tripled. The relationship between "1"3"7Cs and "1"3"3Cs in rice plants was not correlative in the first experimental year at each site, but correlation became evident in the subsequent year(s). This study demonstrates a novel finding that omitting midsummer drainage and/or delaying drainage during the grain-filling period

Intrinsic Low Hysteresis Touch Mode Capacitive Pressure Sensor

DEFF Research Database (Denmark)

Fragiacomo, Giulio; Pedersen, Thomas; Hansen, Ole

2011-01-01

Hysteresis has always been one of the main concerns when fabricating touch mode capacitive pressure sensors (TMCPS). This phenomenon can be fought at two different levels: during fabrication or after fabrication with the aid of a dedicated signal conditioning circuit. We will describe...... a microfabrication step that can be introduced in order to reduce drastically the hysteresis of this type of sensors without compromising their sensitivity. Medium-high range (0 to 10 bar absolute pressure) TMCPS with a capacitive signal span of over 100pF and less than 1 % hysteresis in the entire pressure range...

A multichannel portable ECG system with capacitive sensors

International Nuclear Information System (INIS)

Oehler, M; Schilling, M; Ling, V; Melhorn, K

2008-01-01

Capacitive sensors can be employed for measuring the electrocardiogram of a human heart without electric contact with the skin. This configuration avoids contact problems experienced by conventional electrocardiography. In our studies, we integrated these capacitive electrocardiogram electrodes in a 15-sensor array and combined this array with a tablet personal computer. By placing the system on the patient's body, we can measure a 15-channel electrocardiogram even through clothes and without any preparation. The goal of this development is to provide a new diagnostic tool that offers the user a reproducible, easy access to a fast and spatially resolved diagnostic 'heart view'

Study of Cs recovery by extraction chromatography (2)

International Nuclear Information System (INIS)

Hoshi, Harutaka; Zhang, Anyun; Uchida, Hiromi; Kuraoka, Etsushu

2005-02-01

In order to apply CalixR14 extractant to extraction chromatography for Cs separation, basic characteristics of CalixR14 adsorbent were studied. CalixR14 impregnated resin and CalixR14 + TBP impregnated resin were prepared. CalixR14 extractant showed no adsorption for Cs by liquid-liquid extraction and CalixR14 impregnated resin also showed no adsorption for Cs. Therefore, it is concluded that CalixR14 itself has no affinity for Cs. On the other hand, Cs was adsorbed onto CalixR14-TBP impregnated resin from a concentrated nitric acid solution. The distribution coefficients of Cs were more than 10 cm 3 /g from 2 to 6 M nitric acid. While Rb showed week adsorption, Na, K, Sr and La showed no adsorption and separation factor was over 100. A slight amount of CalixR14 and TBP was leaked from impregnated resin into the aqueous phase. Separation from simulated liquid waste was carried out by using a column packed with CalixR14-TBP adsorbent. Na, K, Sr and La were not adsorbed onto the column, however, Cs and Rb were adsorbed onto the column. Cs and Rb were eluted from the column by water. Cs and Rb were quantitatively recovered. (author)

Vertical profile of 137Cs in soil.

Science.gov (United States)

Krstić, D; Nikezić, D; Stevanović, N; Jelić, M

2004-12-01

In this paper, a vertical distribution of 137Cs in undisturbed soil was investigated experimentally and theoretically. Soil samples were taken from the surroundings of the city of Kragujevac in central Serbia during spring-summer of 2001. The sampling locations were chosen in such a way that the influence of soil characteristics on depth distribution of 137Cs in soil could be investigated. Activity of 137Cs in soil samples was measured using a HpGe detector and multi-channel analyzer. Based on vertical distribution of 137Cs in soil which was measured for each of 10 locations, the diffusion coefficient of 137Cs in soil was determined. In the next half-century, 137Cs will remain as the source of the exposure. Fifteen years after the Chernobyl accident, and more than 30 years after nuclear probes, the largest activity of 137Cs is still within 10 cm of the upper layer of the soil. This result confirms that the penetration of 137Cs in soil is a very slow process. Experimental results were compared with two different Green functions and no major differences were found between them. While both functions fit experimental data well in the upper layer of soil, the fitting is not so good in deeper layers. Although the curves obtained by these two functions are very close to each other, there are some differences in the values of parameters acquired by them.

The 134Cs uptake by sunflower (Helianthus anuus, Less) cultivated on soil contaminated with 134Cs

International Nuclear Information System (INIS)

Poppy Intan Tjahaja; Putu Sukmabuana

2008-01-01

One of the methods for remediation of contaminated environment is phytoremediation techniques, i.e. the environmental remediation using plants. In this research the bioavailability of sunflower plant (Helianthus anuus, Less) in radiocaesium uptake from soil was studied for being considered as a phytoremediator later. Sunflower plants were cultivated on soil contaminated with 134 Cs with the concentrations of 29,3 kBq/kg ; 117,2 kBq/kg ; 557 kBq/kg for 45 days. As control the sunflowers were also cultivated on non contaminated soil. Observation was carried out every 5 days by sampling 3 plants and soils. The plant and soil samples were dried using infra red lamp for 24 hours, and then counted using gamma spectrometer. The counting results i.e. 134 Cs concentration on soil and plant parts were then analyzed to obtain transfer factor (TF) values. The highest TF values was reached on 26 th day, i.e. 0,87; 1,89 ; 2,82 for initial soil 134 Cs concentrations of 29,3 Bq/g ; 117,2 Bq/g ; 557 Bq/g, respectively. The TF values obtained expressed the capability of plants to accumulate 134 Cs from soils. The observation to the plants growth showed that the plants grew normally on the 134 Cs contaminated soil until the concentration of 557 Bq/g. The sunflower can be considered to be phytoremediator of andosol soil contaminated with Cs radionuclides. (author)

Capacitive sensor for continuous monitoring of high-volume droplet microfluidic generation

KAUST Repository

Conchouso Gonzalez, David

2016-12-19

This paper presents a capacitive sensor for monitoring parallel microfluidic droplet generation. The great electric permittivity difference between common droplet microfluidic fluids such as air, oil and water (ϵoil ≈ 2–3 and ϵwater ≈ 80.4), allows for accurate detection of water in oil concentration changes. Capacitance variations as large as 10 pF between a channel filled with water or dodecane, are used to continuously monitor the output of a parallelization system producing 150 µl/min of water in dodecane emulsions. We also discuss a low cost fabrication process to manufacture these capacitive sensors, which can be integrated to different substrates.

Performance relations in Capacitive Deionization systems

NARCIS (Netherlands)

Limpt, van B.

2010-01-01

Capacitive Deionization (CDI) is a relatively new deionization technology based on the temporary storage of ions on an electrically charged surface. By directing a flow between two oppositely charged surfaces, negatively charged ions will adsorb onto the positively charged surface, and positively

Comparison of gate capacitance extraction methodologies

NARCIS (Netherlands)

Kazmi, S.N.R.; Schmitz, Jurriaan

2008-01-01

In recent years, many new capacitance-voltage measurement approaches have been presented in literature. New approaches became necessary with the rapidly increasing gate current density in newer CMOS generations. Here we present a simulation platform using Silvaco software, to describe the full chain

Current Progress of Capacitive Deionization for Removal of Pollutant Ions

Science.gov (United States)

Gaikwad, Mahendra S.; Balomajumder, Chandrajit

2016-08-01

A mini review of a recently developing water purification technology capacitive deionization (CDI) applied for removal of pollutant ions is provided. The current progress of CDI for removal of different pollutant ions such as arsenic, fluoride, boron, phosphate, lithium, copper, cadmium, ferric, and nitrate ions is presented. This paper aims at motivating new research opportunities in capacitive deionization technology for removal of pollutant ions from polluted water.

Design and testing of a magnetic shield for the Thomson scattering photomultiplier tubes in the stray fields of the ERASMUS tokamak

International Nuclear Information System (INIS)

Desoppere, E.; Van Oost, G.

1983-01-01

A multiple coaxial shield system has been designed for the photomultiplier tubes of the ERASMUS tokamak Thomson scattering diagnostic. A stray field of 75 x 10 -4 T was reduced to 0.01 x 10 -4 T for a field parallel to the tube axis, and to 0.03 x 10 -4 T for a perpendicular field

SR-XRF imaging of Cs highly accumulated in vegetables

International Nuclear Information System (INIS)

Nakai, Izumi; Oda, Nahoko; Terada, Yasuko

2011-01-01

Accumulation of Cs in vegetables was studied with regard to the remediation of radioactive Cs from a nuclear plant accident in Fukushima. It was found that Brassica oleracea var. capitata, Brassica campestris var. perviridis, and Lactuca sativa accumulated Cs to a level of more than 10000 ppm (dry weight) when they were cultivated in 1 mM Cs solution. Two-dimensional distributions of Cs were revealed by SR-XRF imaging showing a homogeneous distribution of Cs in the plant bodies. (author)

Radioecological studies of 137Cs in limnological ecosystems. Biochemical states of 137Cs accumulated in killifish (Medaka, Oryzias latipes) meat

International Nuclear Information System (INIS)

Miyake, Sadaaki; Motegi, Misako; Oosawa, Takashi; Nakazawa, Kiyoaki; Izumo, Yoshiro; Nakamura, Fumio.

1997-01-01

Biochemical states of 137 Cs accumulated in killifish's (Medaka, Oryzias latipes) meat were investigated in order to elucidate the accumulation mechanism of the radionuclide in goldfish, Carassius auratus auratus, examined in our preceding report. Most of 137 Cs radioactivity in the killifish's raw meat accumulated this radionuclide in the radioactive freshwater, were found in the non-protein nitrogenous compound (NPNC) fraction (>92%), also in the killifish's control raw meat mixed with 137 Cs, the difference between both meat samples was not clear. As the results of gel filtration profiles on Sephadex G-25 for the NPNC fraction of these meats, each only one radioactive peak was shown, also similar to 137 CsCl solution. Moreover, these peaks appeared at the same position. On the other hand, the peak positions absorbed at OD 280nm in the samples were different from those of each radioactive peak. It was so suggested that 137 Cs accumulated in the killifish's meat was shown not to be binding to protein's composition. Furthermore, as the results on thin-layer chromatography, ion-exchange resin chromatography and reaction with 137 Cs in samples and ammonium phosphomolybdate, 137 Cs in the NPNC fraction of the killifish's meat was not almost different from those of each control and 137 CsCl solution. (author)

Locating Depots for Capacitated Vehicle Routing

DEFF Research Database (Denmark)

Gørtz, Inge Li; Nagarajan, Viswanath

2016-01-01

We study a location-routing problem in the context of capacitated vehicle routing. The input to the k-location capacitated vehicle routing problem (k-LocVRP) consists of a set of demand locations in a metric space and a fleet of k identical vehicles, each of capacity Q. The objective is to locate k...... depots, one for each vehicle, and compute routes for the vehicles so that all demands are satisfied and the total cost is minimized. Our main result is a constant-factor approximation algorithm for k-LocVRP. In obtaining this result, we introduce a common generalization of the k-median and minimum...... spanning tree problems (called k median forest), which might be of independent interest. We give a local-search based (3+ε)-approximation algorithm for k median forest, which leads to a (12+ε)-approximation algorithm for k-LocVRP, for any constant ε>0....

Locating Depots for Capacitated Vehicle Routing

DEFF Research Database (Denmark)

Gørtz, Inge Li; Nagarajan, Viswanath

2016-01-01

depots, one for each vehicle, and compute routes for the vehicles so that all demands are satisfied and the total cost is minimized. Our main result is a constant-factor approximation algorithm for k-LocVRP. In obtaining this result, we introduce a common generalization of the k-median and minimum...... spanning tree problems (called k median forest), which might be of independent interest. We give a local-search based (3+ε)-approximation algorithm for k median forest, which leads to a (12+ε)-approximation algorithm for k-LocVRP, for any constant ε>0.......We study a location-routing problem in the context of capacitated vehicle routing. The input to the k-location capacitated vehicle routing problem (k-LocVRP) consists of a set of demand locations in a metric space and a fleet of k identical vehicles, each of capacity Q. The objective is to locate k...

Comparison of CsI(Tl) and CsI(Na) partially slotted crystals for high-resolution SPECT imaging

International Nuclear Information System (INIS)

Giokaris, N.; Loudos, G.; Maintas, D.; Karabarbounis, A.; Lembesi, M.; Spanoudaki, V.; Stiliaris, E.; Boukis, S.; Sakellios, N.; Karakatsanis, N.; Gektin, A.; Boyarintsev, A.; Pedash, V.; Gayshan, V.

2006-01-01

Dedicated systems based on Position Sensitive Photomultiplier Tubes (PSPMTs) coupled to scintillators, have been used over the past years for the construction of compact systems, suitable for applications such as small animal imaging and small organs imaging. Most of the proposed systems are based on fully pixelized scintillators. Previous studies have shown that partially slotted scintillators offer a good compromise between cost, energy resolution and spatial resolution. In this work, the performance of two sets of CsI(Tl) and CsI(Na) partially slotted crystals is compared. Initial results show that CsI(Tl) scintillators are more suitable for gamma-ray detection, since their performance in terms of sensitivity, spatial and energy resolution is superior than that of CsI(Na)

Effect of noncovalent basal plane functionalization on the quantum capacitance in graphene.

Science.gov (United States)

Ebrish, Mona A; Olson, Eric J; Koester, Steven J

2014-07-09

The concentration-dependent density of states in graphene allows the capacitance in metal-oxide-graphene structures to be tunable with the carrier concentration. This feature allows graphene to act as a variable capacitor (varactor) that can be utilized for wireless sensing applications. Surface functionalization can be used to make graphene sensitive to a particular species. In this manuscript, the effect on the quantum capacitance of noncovalent basal plane functionalization using 1-pyrenebutanoic acid succimidyl ester and glucose oxidase is reported. It is found that functionalized samples tested in air have (1) a Dirac point similar to vacuum conditions, (2) increased maximum capacitance compared to vacuum but similar to air, (3) and quantum capacitance "tuning" that is greater than that in vacuum and ambient atmosphere. These trends are attributed to reduced surface doping and random potential fluctuations as a result of the surface functionalization due to the displacement of H2O on the graphene surface and intercalation of a stable H2O layer beneath graphene that increases the overall device capacitance. The results are important for future application of graphene as a platform for wireless chemical and biological sensors.

Design, Development and Testing of a Semicircular Type Capacitive Angular Position Sensor

Directory of Open Access Journals (Sweden)

Nikhil GAURAV

2011-06-01

Full Text Available A low cost semicircular type capacitive angular position sensor has been designed, developed and tested. It is made of two semicircular parallel plates where one plate is fixed and another plate is connected with the rotor whose angular position is to be measured. When the angular position of the rotor changes with respect to the fixed plate, the overlapping area between the two plates of the capacitor is varied causing a change in capacitance value. Capacitance variation obtained due to the change in angular position is in the nano farad range. For signal conditioning, series R-L-C resonating circuit instead of conventional bridge circuit has been used to convert the sensor capacitance variation in to voltage. Experimental result shows that the capacitance for change in angular position 0º-180º increases linearly and for 180º-360º it decreases linearly. To get a linearly increasing response of same slope for the full scale of 0º-360º, a suitable linearising circuit has been designed, developed and tested. Sensor output along with the signal conditioning shows good linearity and repeatability.

Electric double-layer capacitance between an ionic liquid and few-layer graphene.

Science.gov (United States)

Uesugi, Eri; Goto, Hidenori; Eguchi, Ritsuko; Fujiwara, Akihiko; Kubozono, Yoshihiro

2013-01-01

Ionic-liquid gates have a high carrier density due to their atomically thin electric double layer (EDL) and extremely large geometrical capacitance Cg. However, a high carrier density in graphene has not been achieved even with ionic-liquid gates because the EDL capacitance CEDL between the ionic liquid and graphene involves the series connection of Cg and the quantum capacitance Cq, which is proportional to the density of states. We investigated the variables that determine CEDL at the molecular level by varying the number of graphene layers n and thereby optimising Cq. The CEDL value is governed by Cq at n 4. This transition with n indicates a composite nature for CEDL. Our finding clarifies a universal principle that determines capacitance on a microscopic scale, and provides nanotechnological perspectives on charge accumulation and energy storage using an ultimately thin capacitor.

Development and analysis of a capacitive touch sensor using a liquid metal droplet

International Nuclear Information System (INIS)

Baek, Seungbum; Won, Dong-Joon; Kim, Joong Gil; Kim, Joonwon

2015-01-01

In this paper, we introduce a small-sized capacitive touch sensor with large variations in its capacitance. This sensor uses the changes in capacitance caused by the variation of the overlap area between a liquid metal (LM) droplet and a flat electrode while keeping the gap between the droplet and the bottom electrode at a small constant value (i.e. thickness of dielectric layer). Initially, the droplet is placed inside a polydimethylsiloxane (PDMS) chamber, and a thin silicon dioxide film separates the droplet and the electrode. Owing to the high surface tension of the LM, the droplet retains its spherical shape and the overlap area remains small, which means that the capacitance between the droplet and the electrode also remains small. When normal force is applied, the pressure on the membrane pushes the droplet downward, thus spreading the droplet to the bottom of the chamber and increasing the capacitance. To verify our concept, we performed theoretical analyses and experiments using a 2 mm  ×  2 mm  ×  2 mm 1-cell touch sensor. Finally, we obtained a capacitance variation of ∼30 pF by applying forces between 0 N and 1 N. (paper)

Stray current induced corrosion in lightning rod cables of 525 kV power lines towers: a case study

OpenAIRE

Wojcicki, F. R.; Negrisoli, M. E. M.; Franco, C. V.

2003-01-01

With the growth of several areas in modem society, the necessity to generate and carry electrical energy to big cities has greatly increased. Cables supported by power towers with galvanized steel foundation usually carry energy. As the foundations are underground they may cause high rates of corrosion. These are usually detected by a conventional potential measurement using a Cu/CuSO₄ reference electrode. It is believed that corrosion results from stray currents that f...

Manganese oxide micro-supercapacitors with ultra-high areal capacitance

Science.gov (United States)

Wang, Xu; Myers, Benjamin D.; Yan, Jian; Shekhawat, Gajendra; Dravid, Vinayak; Lee, Pooi See

2013-05-01

A symmetric micro-supercapacitor is constructed by electrochemically depositing manganese oxide onto micro-patterned current collectors. High surface-to-volume ratio of manganese oxide and short diffusion distance between electrodes give an ultra-high areal capacitance of 56.3 mF cm-2 at a current density of 27.2 μA cm-2.A symmetric micro-supercapacitor is constructed by electrochemically depositing manganese oxide onto micro-patterned current collectors. High surface-to-volume ratio of manganese oxide and short diffusion distance between electrodes give an ultra-high areal capacitance of 56.3 mF cm-2 at a current density of 27.2 μA cm-2. Electronic supplementary information (ESI) available: Experimental procedures; optical images of micro-supercapacitors; areal capacitances of samples M-0.3C, M-0.6C and M-0.9C; illustration of interdigital finger electrodes; Nyquist plot of Co(OH)2 deposited on micro-electrodes. See DOI: 10.1039/c3nr00210a

CsI and some new photocathodes

International Nuclear Information System (INIS)

Anderson, D.F.; Kwan, S.; Peskov, V.

1993-06-01

A discussion of the possible sources of discrepancies in the measurements of the quantum efficiency of CsI photocathodes is presented. We propose that the major causes for disagreements in QE are due to the QE dependence on the current density extracted from the photocathode, on the electric field, and on the temperature of the photocathode. Preliminary results on TMAE enhanced GaAs and Si, plus TMAE protected CsTe and SbCs photocathodes, operated in gas, are also presented

137Cs distribution in guava trees

International Nuclear Information System (INIS)

Mosquera, B.; Veiga, R.; Mangia, L.; Carvalho, C.; Estellita, L.; Uzeda, D.; Facure, A.; Violini, B.; Anjos, R.M.

2004-01-01

This paper presents results of 137 Cs concentration measured from a guava tree cultivated after the first decontamination work of one of the sites where the worst Brazilian radiological accident occurred. The present work aims to verify how the 137 Cs is transported and distributed along the tropical trees. Bi-dimensional analyses of the radial distribution of 137 Cs in the main trunk are also presented. Neither symmetrical nor homogeneous behaviors of the specific activity distribution in the tree rings were observed. (author)

Coordination polyhedra CsCln in crystals

International Nuclear Information System (INIS)

Serezhkin, V.N.; Serezhkina, L.B.

1999-01-01

Characteristics of the Voronoi-Dirichlet polyhedrons are estimated for 133 crystallographic cesium atoms in chlorides Cs x M y Cl z (M=Cd, Sc, V, Nb, Mo, W, Ru, Re, etc.). It is found that cesium atoms have coordination numbers 6,8,9,10, 11 and 12 as regards the chlorine atoms. The results of cesium atom coordination sphere examination by the crossing spheres method are presented. Metal-metal interactions (including Cs-Cs) in the structure of certain chlorides are revealed

CMOS MEMS capacitive absolute pressure sensor

International Nuclear Information System (INIS)

Narducci, M; Tsai, J; Yu-Chia, L; Fang, W

2013-01-01

This paper presents the design, fabrication and characterization of a capacitive pressure sensor using a commercial 0.18 µm CMOS (complementary metal–oxide–semiconductor) process and postprocess. The pressure sensor is capacitive and the structure is formed by an Al top electrode enclosed in a suspended SiO 2 membrane, which acts as a movable electrode against a bottom or stationary Al electrode fixed on the SiO 2 substrate. Both the movable and fixed electrodes form a variable parallel plate capacitor, whose capacitance varies with the applied pressure on the surface. In order to release the membranes the CMOS layers need to be applied postprocess and this mainly consists of four steps: (1) deposition and patterning of PECVD (plasma-enhanced chemical vapor deposition) oxide to protect CMOS pads and to open the pressure sensor top surface, (2) etching of the sacrificial layer to release the suspended membrane, (3) deposition of PECVD oxide to seal the etching holes and creating vacuum inside the gap, and finally (4) etching of the passivation oxide to open the pads and allow electrical connections. This sensor design and fabrication is suitable to obey the design rules of a CMOS foundry and since it only uses low-temperature processes, it allows monolithic integration with other types of CMOS compatible sensors and IC (integrated circuit) interface on a single chip. Experimental results showed that the pressure sensor has a highly linear sensitivity of 0.14 fF kPa −1 in the pressure range of 0–300 kPa. (paper)

Beating of magnetic oscillations in a graphene device probed by quantum capacitance

KAUST Repository

Tahir, M.; Schwingenschlö gl, Udo

2012-01-01

We report the quantum capacitance of a monolayergraphene device in an external perpendicular magnetic field including the effects of Rashba spin-orbit interaction(SOI). The SOI mixes the spin up and spin down states of neighbouring Landau levels into two (unequally spaced) energy branches. In order to investigate the role of the SOI for the electronic transport, we study the density of states to probe the quantum capacitance of monolayergraphene.SOIeffects on the quantum magnetic oscillations (Shubnikov de Haas and de Hass-van Alphen) are deduced from the quantum capacitance.

Beating of magnetic oscillations in a graphene device probed by quantum capacitance

KAUST Repository

Tahir, M.

2012-07-05

We report the quantum capacitance of a monolayergraphene device in an external perpendicular magnetic field including the effects of Rashba spin-orbit interaction(SOI). The SOI mixes the spin up and spin down states of neighbouring Landau levels into two (unequally spaced) energy branches. In order to investigate the role of the SOI for the electronic transport, we study the density of states to probe the quantum capacitance of monolayergraphene.SOIeffects on the quantum magnetic oscillations (Shubnikov de Haas and de Hass-van Alphen) are deduced from the quantum capacitance.

A capacitive level shifter for high voltage (2.5kV)

DEFF Research Database (Denmark)

Andersen, Thomas; Andersen, Michael A. E.; Thomsen, Ole Cornelius

2012-01-01

with focus on low power consumption as well as low capacitive load between the floating half-bridge node and ground (output capacitance). The operation of the level-shifter is tested and verified by measurements on a prototype half-bridge gate driver. Results conclude stabile operation at 2.44kV, 50k...

CS EMISSION NEAR MIR-BUBBLES

International Nuclear Information System (INIS)

Watson, C.; Devine, Kathryn; Quintanar, N.; Candelaria, T.

2016-01-01

We survey 44 young stellar objects located near the edges of mid-IR-identified bubbles in CS (1–0) using the Green Bank Telescope. We detect emission in 18 sources, indicating young protostars that are good candidates for being triggered by the expansion of the bubble. We calculate CS column densities and abundances. Three sources show evidence of infall through non-Gaussian line-shapes. Two of these sources are associated with dark clouds and are promising candidates for further exploration of potential triggered star formation. We obtained on-the-fly maps in CS (1–0) of three sources, showing evidence of significant interactions between the sources and the surrounding environment

CS EMISSION NEAR MIR-BUBBLES

Energy Technology Data Exchange (ETDEWEB)

Watson, C. [Manchester University, Department of Physics, 604 E. College Ave., North Manchester, IN 46962 (United States); Devine, Kathryn [College of Idaho, Department of Physics, 2112 Cleveland Blvd, Caldwell, ID 83605 (United States); Quintanar, N. [Texas A and M University, Department of Nuclear Engineering, 401 Joe Routt Blvd, College Station, TX 77843 (United States); Candelaria, T., E-mail: cwatson@manchester.edu, E-mail: KDevine@collegeofidaho.edu, E-mail: nrquintanar@tamu.edu, E-mail: tcandela@nmt.edu [New Mexico Institute of Mining and Technology, Department of Physics, 801 Leroy Place, Socorro, NM 87801 (United States)

2016-02-10

We survey 44 young stellar objects located near the edges of mid-IR-identified bubbles in CS (1–0) using the Green Bank Telescope. We detect emission in 18 sources, indicating young protostars that are good candidates for being triggered by the expansion of the bubble. We calculate CS column densities and abundances. Three sources show evidence of infall through non-Gaussian line-shapes. Two of these sources are associated with dark clouds and are promising candidates for further exploration of potential triggered star formation. We obtained on-the-fly maps in CS (1–0) of three sources, showing evidence of significant interactions between the sources and the surrounding environment.

Fractionation of 137Cs and Pu in natural peatland

International Nuclear Information System (INIS)

Mihalík, Ján; Bartusková, Miluše; Hölgye, Zoltán; Ježková, Tereza; Henych, Ondřej

2014-01-01

High Cs-137 concentrations in plants growing on peatland inspired us to investigate the quantity of its bioavailable fraction in natural peat. Our investigation aims to: a) estimate the quantity of bioavailable Cs-137 and Pu present in peat, b) verify the similarity of Cs-137 and K-40 behaviours, and c) perform a quantification of Cs-137 and Pu transfer from peat to plants. We analysed the vertical distribution of Cs-137 and Pu isotopes in the peat and their concentrations in plants growing on these places. Bioavailability of radionuclides was investigated by sequential extraction. Sequential analyses revealed that it was the upper layer which contained the majority of Cs-137 in an available form while deeper layers retained Cs-137 in immobile fractions. We can conclude that 18% of all Cs-137 in the peat is still bioavailable. Despite of the low quantity of bioavailable fraction of Cs-137 its transfer factor reached extremely high values. In the case of Pu, 64% of its total amount was associated with fulvic/humic acids which resulted in the high transfer factor from peat to plants. 27 years after the Chernobyl nuclear accident, the significant part of radionuclides deposited in peatland is still bioavailable. - Highlights: • Decrease of exchangeable 137 Cs and its increase in residual fraction with depth. • High 137 Cs transfer factor contrary to its low quantity in bioavailable fractions. • Fulvic/humic acids are a more effective carrier for Pu than for Cs

Thermodynamic cycle analysis for capacitive deionization

NARCIS (Netherlands)

Biesheuvel, P.M.

2009-01-01

Capacitive deionization (CDI) is an ion removal technology based on temporarily storing ions in the polarization layers of two oppositely positioned electrodes. Here we present a thermodynamic model for the minimum work required for ion separation in the fully reversible case by describing the ionic

Profiling of barrier capacitance and spreading resistance using a transient linearly increasing voltage technique.

Science.gov (United States)

Gaubas, E; Ceponis, T; Kusakovskij, J

2011-08-01

A technique for the combined measurement of barrier capacitance and spreading resistance profiles using a linearly increasing voltage pulse is presented. The technique is based on the measurement and analysis of current transients, due to the barrier and diffusion capacitance, and the spreading resistance, between a needle probe and sample. To control the impact of deep traps in the barrier capacitance, a steady state bias illumination with infrared light was employed. Measurements of the spreading resistance and barrier capacitance profiles using a stepwise positioned probe on cross sectioned silicon pin diodes and pnp structures are presented.

Capacitive MEMS-based sensors : thermo-mechanical stability and charge trapping

OpenAIRE

van Essen, M.C.

2009-01-01

Micro-Electro Mechanical Systems (MEMS) are generally characterized as miniaturized systems with electrostatically driven moving parts. In many cases, the electrodes are capacitively coupled. This basic scheme allows for a plethora of specifications and functionality. This technology has presently matured and is widely employed in industry. A voltage across the electrodes will attract the movable part. This relation between electric field and separation (or capacitance) can be conveniently em...

Compensation of the detector capacitance presented to charge-sensitive preamplifiers using the Miller effect

Energy Technology Data Exchange (ETDEWEB)

Kwon, Inyong, E-mail: iykwon@umich.edu [University of Michigan, Ann Arbor, MI (United States); Kang, Taehoon, E-mail: thnkang@umich.edu [University of Michigan, Ann Arbor, MI (United States); Wells, Byron T., E-mail: wells@galtresearch.com [Galt LLC, Ypsilanti, MI (United States); D’Aries, Lawrence J., E-mail: lawrence.j.daries.civ@mail.mil [Picatinny Arsenal, Rockaway Township, NJ (United States); Hammig, Mark D., E-mail: hammig@umich.edu [University of Michigan, Ann Arbor, MI (United States)

2015-06-01

This paper describes an integrated circuit design for a modified charge-sensitive amplifier (CSA) that compensates for the effect of capacitance presented by nuclear radiation detectors and other sensors. For applications that require large area semiconductor detectors or for those semiconductor sensors derived from high permittivity materials such as PbSe, the detector capacitance can degrade the system gain and bandwidth of a front-end preamplifier, resulting in extended rise times and attenuated output voltage signals during pulse formation. In order to suppress the effect of sensor capacitance, we applied a bootstrap technique into a traditional CSA. The technique exploits the Miller effect by reducing the effective voltage difference between the two sides of a radiation detector which minimizes the capacitance presented to the differential common-source amplifier. This new configuration is successfully designed to produce effective gain even at high detector capacitance. The entire circuit, including a core CSA with feedback components and a bootstrap amplifier, are implemented in a 0.18 μm CMOS process with a 3.3 V supply voltage. - Highlights: • A modified CSA was implemented for detector capacitance compensation. • Increasing detector capacitance degrades gain and rise time. • A bootstrap amplifier exploiting the Miller effect is described. • It allows using large area radiation sensors for high radiation-interaction rates. • Intensive noise analyses show that SNR is much better with the technique.

Capacitive performance of molybdenum nitride/titanium nitride nanotube array for supercapacitor

Energy Technology Data Exchange (ETDEWEB)

Xie, Yibing, E-mail: ybxie@seu.edu.cn; Tian, Fang

2017-01-15

Highlights: • MoN{sub x}/TiN NTA is fully converted from MoO{sub 2}/TiO{sub 2} NTA by one-step nitridation process. • MoN{sub x}/TiN NTA is used as feasible electrode material of high-performance supercapacitor. • MoN{sub x}/TiN NTA shows high capacitance, rate capability and cycling stability. - Abstract: Molybdenum nitride (MoN{sub x}) depositing on titanium nitride nanotube array (TiN NTA) was designed as MoN{sub x}/TiN NTA for supercapacitor electrode material. MoN{sub x}/TiN NTA was fabricated by electrodepositing molybdenum oxide onto titanium dioxide NTA and one-step nitridation treatment in ammonia. MoN{sub x}/TiN NTA involved top-surface layer of MoN{sub x} nanoparticles and underlying layer of TiN NTA, which contributed to electric double layer capacitance in aqueous lithium-ion electrolyte solution. The specific capacitance was increased from 69.05 mF cm{sup −2} for TiN NTA to 121.50 mF cm{sup −2} for MoN{sub x}/TiN NTA at 0.3 mA cm{sup −2}, presenting the improved capacitance performance. MoN{sub x} exhibited the capacitance of 174.83 F g{sup −1} at 1.5 A g{sup −1} and slightly declined to 109.13 F g{sup −1} at 30 A g{sup −1}, presenting high rate capability. MoN{sub x}/TiN NTA exhibited the capacitance retention ratio of 93.8% at 3.0 mA cm{sup −2} after 1000 cycles, presenting high cycling stability. MoN{sub x}/TiN NTA could act as a promising electrode material of supercapacitor.

DNA Nucleotides Detection via capacitance properties of Graphene

Science.gov (United States)

Khadempar, Nahid; Berahman, Masoud; Yazdanpanah, Arash

2016-05-01

In the present paper a new method is suggested to detect the DNA nucleotides on a first-principles calculation of the electronic features of DNA bases which chemisorbed to a graphene sheet placed between two gold electrodes in a contact-channel-contact system. The capacitance properties of graphene in the channel are surveyed using non-equilibrium Green's function coupled with the Density Functional Theory. Thus, the capacitance properties of graphene are theoretically investigated in a biological environment, and, using a novel method, the effect of the chemisorbed DNA nucleotides on electrical charges on the surface of graphene is deciphered. Several parameters in this method are also extracted including Electrostatic energy, Induced density, induced electrostatic potential, Electron difference potential and Electron difference density. The qualitative and quantitative differences among these parameters can be used to identify DNA nucleotides. Some of the advantages of this approach include its ease and high accuracy. What distinguishes the current research is that it is the first experiment to investigate the capacitance properties of gaphene changes in the biological environment and the effect of chemisorbed DNA nucleotides on the surface of graphene on the charge.

{sup 137}Cs in northern Adriatic sediments

Energy Technology Data Exchange (ETDEWEB)

Barisic, D; Lulic, S; Vdovic, N; Vertacnik, A [Center for Marine Research - Department Zagreb, ' Ruder Boskovic' Institute, Zagreb (Croatia); Juracic, M [Department of Geology, Faculty of Natural Sciences, University of Zagreb, Zagreb (Croatia)

1996-01-01

The activity of {sup 137}Cs in shallow northern Adriatic sediments was obtained on the basis of measurement results from 25 sediment box cores, sampled during the Adriatic Scientific COoperation Program (ASCOP) 16 cruise in the summer 1990. {sup 137}Cs was determined in surface sediments (0-3 cm) and 12-15 cm-deep sediment. It was found that the lowest caesium concentrations correspond to sands, which are spread along the Croatian coast. Parallel to the Italian coast, {sup 137}Cs concentrations in pelites are the highest. It seems that the influence of Po River is significant for {sup 137}Cs activities in recent marine sediments along Italian coast south of Po River delta. Significantly higher {sup 137}Cs activities in 0-3 cm sediment layer can be attributed to the deposition caused by Chernobyl accident. (author)

Role of Catecholamine in Tumor Angiogenesis Linked to Capacitance Relaxation Phenomenon

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Guangyue SHI

2010-08-01

Full Text Available The present paper deals with the CgA level during metastasis linked with Capacitance relaxation phenomenon in cancer cell. CgA co-stored and correlated by exocytosis with catecholamines is a precursor to peptides that exert feedback regulatory control on catecholamine secretion. It is to be noted that CgA was the most sensitive marker for detecting patients with tumor angiogenesis. The progressive rise in CgA increases with the tumor size and this fact has been correlated with the Capacitance relaxation phenomenon (T. K. Basak, US patent No. 5691178, 1997 in different stages. The experimental results of Capacitance relaxation phenomenon were given as inputs to a model for correlation with the CgA level. This model is a control system model, the output of which is the CgA level. It is to be noted that the model is simulated in MATLAB. The expression of tumorogenisis in prostate and liver is also linked to Capacitance relaxation phenomenon in respect of its correlation with the CgA level.

Transfer of 137Cs to wild vegetables

International Nuclear Information System (INIS)

Ito, Nobuhiko; Natsuhori, Masahiro; Mezawa, Akane; Kawakami, Akira

1998-01-01

For the evaluation of internal radiation dose, it is needed to estimate the amount of radionuclide incorporated to human body using a simulation model. 137 Cesium (Cs) is easily transferred associating with food intake as well as potassium and so, Cs is an important nuclide for evaluation of internal radiation. 137 Cs concentrations in wild vegetables are higher than those of cultured vegetables and milk. Therefore, the transfer coefficients of 137 Cs from soil to wild vegetables were estimated in this study. Wild vegetables and soils of their farms were collected in the Hakkoda Mountain range of Aomori Prefecture. The levels of 137 Cs in wild vegetables were 0.42-18.35 (Bq/kg), whereas those in cabbage and spinach were 0.08 and 0.01 (Bq/kg), respectively, indicating that the Cs level is dozens to several hundreds times higher in wild vegetables than cultured ones. And the transfer coefficient was estimated as 0.003-0.94 for the former and 0.001-0.8 for the latter. On the other hand, 1 37 Cs levels of the soils on which wild vegetables grew was 28.0 Bq/kg and it was 3.9 Bq/kg for the farm soil. Furthermore, the effects of water content and pH of the soil on the transfer coefficient were studied. (M.N.)

Imbedded Nanocrystals of CsPbBr3 in Cs4 PbBr6 : Kinetics, Enhanced Oscillator Strength, and Application in Light-Emitting Diodes.

Science.gov (United States)

Xu, Junwei; Huang, Wenxiao; Li, Peiyun; Onken, Drew R; Dun, Chaochao; Guo, Yang; Ucer, Kamil B; Lu, Chang; Wang, Hongzhi; Geyer, Scott M; Williams, Richard T; Carroll, David L

2017-11-01

Solution-grown films of CsPbBr 3 nanocrystals imbedded in Cs 4 PbBr 6 are incorporated as the recombination layer in light-emitting diode (LED) structures. The kinetics at high carrier density of pure (extended) CsPbBr 3 and the nanoinclusion composite are measured and analyzed, indicating second-order kinetics in extended and mainly first-order kinetics in the confined CsPbBr 3 , respectively. Analysis of absorption strength of this all-perovskite, all-inorganic imbedded nanocrystal composite relative to pure CsPbBr 3 indicates enhanced oscillator strength consistent with earlier published attribution of the sub-nanosecond exciton radiative lifetime in nanoprecipitates of CsPbBr 3 in melt-grown CsBr host crystals and CsPbBr 3 evaporated films. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Inverter-based successive approximation capacitance-to-digital converter

KAUST Repository

Omran, Hesham

2017-03-23

An energy-efficient capacitance-to-digital converter (CDC) is provided that utilizes a capacitance-domain successive approximation (SAR) technique. Unlike SAR analog- to-digital converters (ADCs), analysis shows that for SAR CDCs, the comparator offset voltage will result in signal-dependent and parasitic-dependent conversion errors, which necessitates an op-amp-based implementation. The inverter-based SAR CDC contemplated herein provides robust, energy-efficient, and fast operation. The inverter- based SAR CDC may include a hybrid coarse-fine programmable capacitor array. The design of example embodiments is insensitive to analog references, and thus achieves very low temperature sensitivity without the need for calibration. Moreover, this design achieves improved energy efficiency.

Actuatable capacitive transducer for quantitative nanoindentation combined with transmission electron microscopy

Science.gov (United States)

Warren, Oden L.; Asif, S. A. Syed; Cyrankowski, Edward; Kounev, Kalin

2010-09-21

An actuatable capacitive transducer including a transducer body, a first capacitor including a displaceable electrode and electrically configured as an electrostatic actuator, and a second capacitor including a displaceable electrode and electrically configured as a capacitive displacement sensor, wherein the second capacitor comprises a multi-plate capacitor. The actuatable capacitive transducer further includes a coupling shaft configured to mechanically couple the displaceable electrode of the first capacitor to the displaceable electrode of the second capacitor to form a displaceable electrode unit which is displaceable relative to the transducer body, and an electrically-conductive indenter mechanically coupled to the coupling shaft so as to be displaceable in unison with the displaceable electrode unit.-

A Capacitive Humidity Sensor Based on Multi-Wall Carbon Nanotubes (MWCNTs

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