WorldWideScience

Sample records for reported capacitance images

  1. Image Reconstruction Using a Genetic Algorithm for Electrical Capacitance Tomography

    Institute of Scientific and Technical Information of China (English)

    MOU Changhua; PENG Lihui; YAO Danya; XIAO Deyun

    2005-01-01

    Electrical capacitance tomography (ECT) has been used for more than a decade for imaging dielectric processes. However, because of its ill-posedness and non-linearity, ECT image reconstruction has always been a challenge. A new genetic algorithm (GA) developed for ECT image reconstruction uses initial results from a linear back-projection, which is widely used for ECT image reconstruction to optimize the threshold and the maximum and minimum gray values for the image. The procedure avoids optimizing the gray values pixel by pixel and significantly reduces the search space dimension. Both simulations and static experimental results show that the method is efficient and capable of reconstructing high quality images. Evaluation criteria show that the GA-based method has smaller image error and greater correlation coefficients. In addition, the GA-based method converges quickly with a small number of iterations.

  2. Sugar Cube Purity: Capacitive Sensing and Image Processing Approach

    Science.gov (United States)

    Madhumitha, S.; Rajath, R.; Venkatanathan, N.; Raajan, N. R.; Sridharan, M.

    2016-12-01

    Several methods have been implemented to find out if impurity is present in sugar cubes or powders so far. Several high end imaging techniques with X-ray scanners have been used to check the quality of the sugar. In this present study, without disturbing the physical nature of sugar, we have simply used the dielectric property analysis to check the purity of the sugar. This method can detect even infinitesimal amounts of impurity present in sugar with good accuracy. The positional accuracy is derived using artificial neural networks, which is been trained with various capacitance values when the impurity is present and gives the details on the change in capacitance value as the impurity position changes.

  3. An FPGA-based ultrasound imaging system using capacitive micromachined ultrasonic transducers.

    Science.gov (United States)

    Wong, Lawrence L P; Chen, Albert I; Logan, Andrew S; Yeow, John T W

    2012-07-01

    We report the design and experimental results of a field-programmable gate array (FPGA)-based real-time ultrasound imaging system that uses a 16-element phased-array capacitive micromachined ultrasonic transducer fabricated using a fusion bonding process. The imaging system consists of the transducer, discrete analog components situated on a custom-made circuit board, the FPGA, and a monitor. The FPGA program consists of five functional blocks: a main counter, transmit and receive beamformer, receive signal pre-processing, envelope detection, and display. No dedicated digital signal processor or personal computer is required for the imaging system. An experiment is carried out to obtain the sector B-scan of a 4-wire target. The ultrasound imaging system demonstrates the possibility of an integrated system-in-a-package solution.

  4. In vivo skin capacitive imaging analysis by using grey level co-occurrence matrix (GLCM).

    Science.gov (United States)

    Ou, Xiang; Pan, Wei; Xiao, Perry

    2014-01-02

    We present our latest work on in vivo skin capacitive imaging analysis by using grey level co-occurrence matrix (GLCM). The in vivo skin capacitive images were taken by a capacitance based fingerprint sensor, the skin capacitive images were then analysed by GLCM. Four different GLCM feature vectors, angular second moment (ASM), entropy (ENT), contrast (CON) and correlation (COR), are selected to describe the skin texture. The results show that angular second moment increases as age increases, and entropy decreases as age increases. The results also suggest that the angular second moment values and the entropy values reflect more about the skin texture, whilst the contrast values and the correlation values reflect more about the topically applied solvents. The overall results shows that the GLCM is an effective way to extract and analyse the skin texture information, which can potentially be a valuable reference for evaluating effects of medical and cosmetic treatments.

  5. A nonlinear fuzzy assisted image reconstruction algorithm for electrical capacitance tomography.

    Science.gov (United States)

    Deabes, W A; Abdelrahman, M A

    2010-01-01

    A nonlinear method based on a Fuzzy Inference System (FIS) to improve the images obtained from Electrical Capacitance Tomography (ECT) is proposed. Estimation of the molten metal characteristic in the Lost Foam Casting (LFC) process is a novel application in the area of the tomography process. The convergence rate of iterative image reconstruction techniques is dependent on the accuracy of the first image. The possibility of the existence of metal in the first image is computed by the proposed fuzzy system. This first image is passed to an iterative image reconstruction technique to get more precise images and to speed up the convergence rate. The proposed technique is able to detect the position of the metal on the periphery of the imaging area by using just eight capacitive sensors. The final results demonstrate the advantage of using the FIS compared to the performance of the iterative back projection image reconstruction technique.

  6. Modeling of Potential Distribution of Electrical Capacitance Tomography Sensor for Multiphase Flow Image

    Directory of Open Access Journals (Sweden)

    S. Sathiyamoorthy

    2007-09-01

    Full Text Available Electrical Capacitance Tomography (ECT was used to develop image of various multi phase flow of gas-liquid-solid in a closed pipe. The principal difficulties to obtained real time image from ECT sensor are permittivity distribution across the plate and capacitance is nonlinear; the electric field is distorted by the material present and is also sensitive to measurement errors and noise. This work present a detailed description is given on method employed for image reconstruction from the capacitance measurements. The discretization and iterative algorithm is developed for improving the predictions with minimum error. The author analyzed eight electrodes square sensor ECT system with two-phase water-gas and solid-gas.

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

    Science.gov (United States)

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

    1998-11-01

    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

  8. Application of electrical capacitance tomography for imaging industrial processes

    Institute of Scientific and Technical Information of China (English)

    DYAKOWSKI Tom

    2005-01-01

    Electrical tomography is, in certain cases, the most attractive method for real imaging of industrial processes, because of its inherent simplicity, rugged cons truction of the tomographer and high-speed capability. This paper presents examples illustrating applications of electrical tomography for imaging fluidized beds, bubble columns and pneumatic conveyors. Electrical tomography opens up new ways for processing, imaging and modelling multi-phase flows as shown by 2D and 3D images illustrating the various types of flow morphology.

  9. Imaging wet gas separation process by capacitance tomography

    Science.gov (United States)

    Yang, Wuqiang; Nguyen, Van T.; Betting, Marco; Chondronasios, Athanasios; Nattras, Steve; Okimoto, Fred; McCann, Hugh

    2002-03-01

    Natural gas from a well contains water and hydrocarbons. It is necessary to separate the liquid components from such gas streams before use. An innovative type of separation facility, called Twister, has been developed for this purpose, and CFD models have been developed to assist in the design of Twister. However, it is difficult to verify the mathematical models directly and experimentally. To investigate the behavior of Twister and to verify the CFD models, a simulator using air and water vapor was set up in the laboratory. This simulator was instrumented with a highly sensitive electrical capacitance tomography (ECT) system based on an HP LCR meter and a purpose-designed multiplexer. Two ECT sensors, each with 8 measurement electrodes, were built taking into consideration the demanding operational conditions, such as sensitivity, temperature, pressure, geometry and location. This paper presents the first experimental results, showing that water droplets distributions in a flowing gas can be visualized using ECT, and the tomography system developed is robust and offers the possibility for further development to field operations.

  10. Skin capacitance imaging and corneosurfametry. A comparative assessment of the impact of surfactants on stratum corneum.

    Science.gov (United States)

    Xhauflaire-Uhoda, Emmanuelle; Loussouarn, Geneviève; Haubrechts, Christelle; Léger, Didier Saint; Piérard, Gérald E

    2006-05-01

    Silicon image sensor (SIS) technology was recently introduced as an innovative tool (SkinChip, L'Oréal) providing sensitive imaging of the skin capacitance. This method can detect discrete focal variations in skin surface hydration, and thus early discrete manifestations of skin irritation induced by surfactants. In the present in vivo study, 2 neat and diluted shampoos, and 5% and 10% sodium laurylsulfate solutions were tested on human skin. Each surfactant solution was gently rubbed on the skin using wet hair wicks mimicking the casual use of a shampoo on the scalp. Clinical and SIS evaluations were carried out. In addition, the same products were tested using the ex vivo corneosurfametry bioassay performed on human stratum corneum (SC) harvested by cyanoacrylate skin surface strippings. The colourimetric index of mildness (CIM) was measured on these samples. The product reactivity with the SC was recognized by darker skin capacitance images, and by both lowered SkinChip-generated values and lowered CIM values. The extent in changes varied according to the nature of the test products and their concentrations. The SkinChip image changes likely corresponded to the acute surfactant-induced water swelling of the corneocytes. Skin capacitance imaging and corneosurfametry allow to disclose discrete surfactant-induced alterations of corneocytes.

  11. An image reconstruction algorithm for electrical capacitance tomography based on simulated annealing particle swarm optimization

    Directory of Open Access Journals (Sweden)

    P. Wang

    2015-04-01

    Full Text Available In this paper, we introduce a novel image reconstruction algorithm with Least Squares Support Vector Machines (LS-SVM and Simulated Annealing Particle Swarm Optimization (APSO, named SAP. This algorithm introduces simulated annealing ideas into Particle Swarm Optimization (PSO, which adopts cooling process functions to replace the inertia weight function and constructs the time variant inertia weight function featured in annealing mechanism. Meanwhile, it employs the APSO procedure to search for the optimized resolution of Electrical Capacitance Tomography (ECT for image reconstruction. In order to overcome the soft field characteristics of ECT sensitivity field, some image samples with typical flow patterns are chosen for training with LS-SVM. Under the training procedure, the capacitance error caused by the soft field characteristics is predicted, and then is used to construct the fitness function of the particle swarm optimization on basis of the capacitance error. Experimental results demonstrated that the proposed SAP algorithm has a quick convergence rate. Moreover, the proposed SAP outperforms the classic Landweber algorithm and Newton-Raphson algorithm on image reconstruction.

  12. Imaging metallic samples using electrical capacitance tomography: forward modelling and reconstruction algorithms

    Science.gov (United States)

    Hosani, E. Al; Zhang, M.; Abascal, J. F. P. J.; Soleimani, M.

    2016-11-01

    Electrical capacitance tomography (ECT) is an imaging technology used to reconstruct the permittivity distribution within the sensing region. So far, ECT has been primarily used to image non-conductive media only, since if the conductivity of the imaged object is high, the capacitance measuring circuit will be almost shortened by the conductivity path and a clear image cannot be produced using the standard image reconstruction approaches. This paper tackles the problem of imaging metallic samples using conventional ECT systems by investigating the two main aspects of image reconstruction algorithms, namely the forward problem and the inverse problem. For the forward problem, two different methods to model the region of high conductivity in ECT is presented. On the other hand, for the inverse problem, three different algorithms to reconstruct the high contrast images are examined. The first two methods are the linear single step Tikhonov method and the iterative total variation regularization method, and use two sets of ECT data to reconstruct the image in time difference mode. The third method, namely the level set method, uses absolute ECT measurements and was developed using a metallic forward model. The results indicate that the applications of conventional ECT systems can be extended to metal samples using the suggested algorithms and forward model, especially using a level set algorithm to find the boundary of the metal.

  13. A novel STM-assisted microwave microscope with capacitance and loss imaging capability.

    Science.gov (United States)

    Imtiaz, Atif; Anlage, Steven M

    2003-04-01

    We report a new technique of scanning capacitance microscopy at microwave frequencies. A near field scanning microwave microscope probe is kept at a constant height of about 1 nm above the sample with the help of scanning tunneling microscope (STM) feedback. The microwaves are incident onto the sample through a coaxial resonator that is terminated at one end with a sharp tip (the same tip is used to conduct STM), and capacitively coupled to a feedback circuit and microwave source at the other end. The feedback circuit keeps the source locked onto the resonance frequency of the resonator and outputs the frequency shift and quality factor change due to property variations of the sample. The spatial resolution due to capacitance variations is congruent with 2.5 nm. The microwave microscope is sensitive to sample sheet resistance, as demonstrated through measurements on a doped silicon sample. We develop a quantitative transmission line model treating the tip to sample interaction as a series combination of capacitance and sheet resistance in the sample.

  14. Image reconstruction algorithms for electrical capacitance tomography based on ROF model using new numerical techniques

    Science.gov (United States)

    Chen, Jiaoxuan; Zhang, Maomao; Liu, Yinyan; Chen, Jiaoliao; Li, Yi

    2017-03-01

    Electrical capacitance tomography (ECT) is a promising technique applied in many fields. However, the solutions for ECT are not unique and highly sensitive to the measurement noise. To remain a good shape of reconstructed object and endure a noisy data, a Rudin–Osher–Fatemi (ROF) model with total variation regularization is applied to image reconstruction in ECT. Two numerical methods, which are simplified augmented Lagrangian (SAL) and accelerated alternating direction method of multipliers (AADMM), are innovatively introduced to try to solve the above mentioned problems in ECT. The effect of the parameters and the number of iterations for different algorithms, and the noise level in capacitance data are discussed. Both simulation and experimental tests were carried out to validate the feasibility of the proposed algorithms, compared to the Landweber iteration (LI) algorithm. The results show that the SAL and AADMM algorithms can handle a high level of noise and the AADMM algorithm outperforms other algorithms in identifying the object from its background.

  15. Processing-optimised imaging of analog geological models by electrical capacitance tomography

    Science.gov (United States)

    Ortiz Alemán, C.; Espíndola-Carmona, A.; Hernández-Gómez, J. J.; Orozco Del Castillo, MG

    2017-06-01

    In this work, the electrical capacitance tomography (ECT) technique is applied in monitoring internal deformation of geological analog models, which are used to study structural deformation mechanisms, in particular for simulating migration and emplacement of allochtonous salt bodies. A rectangular ECT sensor was used for internal visualization of analog geologic deformation. The monitoring of analog models consists in the reconstruction of permittivity images from the capacitance measurements obtained by introducing the model inside the ECT sensor. A simulated annealing (SA) algorithm is used as a reconstruction method, and is optimized by taking full advantage of some special features in a linearized version of this inverse approach. As a second part of this work our SA image reconstruction algorithm is applied to synthetic models, where its performance is evaluated in comparison to other commonly used algorithms such as linear back-projection and iterative Landweber methods. Finally, the SA method is applied to visualise two simple geological analog models. Encouraging results were obtained in terms of the quality of the reconstructed images, as interfaces corresponding to main geological units in the analog model were clearly distinguishable in them. We found reliable results quite useful for real time non-invasive monitoring of internal deformation of analog geological models.

  16. Multiphase permittivity imaging using absolute value electrical capacitance tomography data and a level set algorithm.

    Science.gov (United States)

    Al Hosani, E; Soleimani, M

    2016-06-28

    Multiphase flow imaging is a very challenging and critical topic in industrial process tomography. In this article, simulation and experimental results of reconstructing the permittivity profile of multiphase material from data collected in electrical capacitance tomography (ECT) are presented. A multiphase narrowband level set algorithm is developed to reconstruct the interfaces between three- or four-phase permittivity values. The level set algorithm is capable of imaging multiphase permittivity by using one set of ECT measurement data, so-called absolute value ECT reconstruction, and this is tested with high-contrast and low-contrast multiphase data. Simulation and experimental results showed the superiority of this algorithm over classical pixel-based image reconstruction methods. The multiphase level set algorithm and absolute ECT reconstruction are presented for the first time, to the best of our knowledge, in this paper and critically evaluated. This article is part of the themed issue 'Supersensing through industrial process tomography'. © 2016 The Author(s).

  17. Imaging wet granules with different flow patterns by electrical capacitance tomography and microwave tomography

    Science.gov (United States)

    Wang, H. G.; Zhang, J. L.; Ramli, M. F.; Mao, M. X.; Ye, J. M.; Yang, W. Q.; Wu, Z. P.

    2016-11-01

    The moisture content of granules in fluidised bed drying, granulation and coating processes can typically be between 1%~25%, resulting in the change of permittivity and conductivity during the processes. Electrical capacitance tomography (ECT) has been used for this purpose, but has a limit because too much water can cause a problem in capacitance measurement. Considering that microwave tomography (MWT) has a wide range of frequency (1~2.5 GHz) and can be used to measure materials with high permittivity and conductivity, the objective of this research is to combine ECT and MWT together to investigate the solids concentration with different moisture content and different flow patterns. The measurement results show that both ECT and MWT are functions of moisture content as well as flow patterns, and their measurements are complementary to each other. This is the first time that these two tomography modalities have been combined together and applied to image the complex solids distribution. The obtained information may be used for the process control of fluidised bed drying, granulation and coating to improve operation efficiency.

  18. Preliminary evaluation of cryogenic two-phase flow imaging using electrical capacitance tomography

    Science.gov (United States)

    Xie, Huangjun; Yu, Liu; Zhou, Rui; Qiu, Limin; Zhang, Xiaobin

    2017-09-01

    The potential application of the 2-D eight-electrode electrical capacitance tomography (ECT) to the inversion imaging of the liquid nitrogen-vaporous nitrogen (LN2-VN2) flow in the tube is theoretically evaluated. The phase distribution of the computational domain is obtained using the simultaneous iterative reconstruction technique with variable iterative step size. The detailed mathematical derivations for the calculations are presented. The calculated phase distribution for the two detached LN2 column case shows the comparable results with the water-air case, regardless of the much reduced dielectric permittivity of LN2 compared with water. The inversion images of total eight different LN2-VN2 flow patterns are presented and quantitatively evaluated by calculating the relative void fraction error and the correlation coefficient. The results demonstrate that the developed reconstruction technique for ECT has the capacity to reconstruct the phase distribution of the complex LN2-VN2 flow, while the accuracy of the inversion images is significantly influenced by the size of the discrete phase. The influence of the measurement noise on the image quality is also considered in the calculations.

  19. Second harmonic and subharmonic for non-linear wideband contrast imaging using a capacitive micromachined ultrasonic transducer array.

    Science.gov (United States)

    Novell, Anthony; Escoffre, Jean-Michel; Bouakaz, Ayache

    2013-08-01

    When insonified with suitable ultrasound excitation, contrast microbubbles generate various non-linear scattered components, such as the second harmonic (2H) and the subharmonic (SH). In this study, we exploit the wide frequency bandwidth of capacitive micromachined ultrasonic transducers (CMUTs) to enhance the response from ultrasound contrast agents by selective imaging of both the 2H and SH components simultaneously. To this end, contrast images using the pulse inversion method were recorded with a 64-element CMUT linear array connected to an open scanner. In comparison to imaging at 2H alone, the wideband imaging including both the 2H and SH contributions provided up to 130% and 180% increases in the signal-to-noise and contrast-to-tissue ratios, respectively. The wide-frequency band of CMUTs offers new opportunities for improved ultrasound contrast agent imaging.

  20. First in vivo use of a capacitive micromachined ultrasound transducer array-based imaging and ablation catheter.

    Science.gov (United States)

    Stephens, Douglas N; Truong, Uyen T; Nikoozadeh, Amin; Oralkan, Omer; Seo, Chi Hyung; Cannata, Jonathan; Dentinger, Aaron; Thomenius, Kai; de la Rama, Alan; Nguyen, Tho; Lin, Feng; Khuri-Yakub, Pierre; Mahajan, Aman; Shivkumar, Kalyanam; O'Donnell, Matt; Sahn, David J

    2012-02-01

    The primary objective was to test in vivo for the first time the general operation of a new multifunctional intracardiac echocardiography (ICE) catheter constructed with a microlinear capacitive micromachined ultrasound transducer (ML-CMUT) imaging array. Secondarily, we examined the compatibility of this catheter with electroanatomic mapping (EAM) guidance and also as a radiofrequency ablation (RFA) catheter. Preliminary thermal strain imaging (TSI)-derived temperature data were obtained from within the endocardium simultaneously during RFA to show the feasibility of direct ablation guidance procedures. The new 9F forward-looking ICE catheter was constructed with 3 complementary technologies: a CMUT imaging array with a custom electronic array buffer, catheter surface electrodes for EAM guidance, and a special ablation tip, that permits simultaneous TSI and RFA. In vivo imaging studies of 5 anesthetized porcine models with 5 CMUT catheters were performed. The ML-CMUT ICE catheter provided high-resolution real-time wideband 2-dimensional (2D) images at greater than 8 MHz and is capable of both RFA and EAM guidance. Although the 24-element array aperture dimension is only 1.5 mm, the imaging depth of penetration is greater than 30 mm. The specially designed ultrasound-compatible metalized plastic tip allowed simultaneous imaging during ablation and direct acquisition of TSI data for tissue ablation temperatures. Postprocessing analysis showed a first-order correlation between TSI and temperature, permitting early development temperature-time relationships at specific myocardial ablation sites. Multifunctional forward-looking ML-CMUT ICE catheters, with simultaneous intracardiac guidance, ultrasound imaging, and RFA, may offer a new means to improve interventional ablation procedures.

  1. First In Vivo Use of a Capacitive Micromachined Ultrasound Transducer Array–Based Imaging and Ablation Catheter

    Science.gov (United States)

    Stephens, Douglas N.; Truong, Uyen T.; Nikoozadeh, Amin; Oralkan, Ömer; Seo, Chi Hyung; Cannata, Jonathan; Dentinger, Aaron; Thomenius, Kai; de la Rama, Alan; Nguyen, Tho; Lin, Feng; Khuri-Yakub, Pierre; Mahajan, Aman; Shivkumar, Kalyanam; O’Donnell, Matt; Sahn, David J.

    2012-01-01

    Objectives The primary objective was to test in vivo for the first time the general operation of a new multifunctional intracardiac echocardiography (ICE) catheter constructed with a microlinear capacitive micromachined ultrasound transducer (ML-CMUT) imaging array. Secondarily, we examined the compatibility of this catheter with electroanatomic mapping (EAM) guidance and also as a radiofrequency ablation (RFA) catheter. Preliminary thermal strain imaging (TSI)-derived temperature data were obtained from within the endocardium simultaneously during RFA to show the feasibility of direct ablation guidance procedures. Methods The new 9F forward-looking ICE catheter was constructed with 3 complementary technologies: a CMUT imaging array with a custom electronic array buffer, catheter surface electrodes for EAM guidance, and a special ablation tip, that permits simultaneous TSI and RFA. In vivo imaging studies of 5 anesthetized porcine models with 5 CMUT catheters were performed. Results The ML-CMUT ICE catheter provided high-resolution real-time wideband 2-dimensional (2D) images at greater than 8 MHz and is capable of both RFA and EAM guidance. Although the 24-element array aperture dimension is only 1.5 mm, the imaging depth of penetration is greater than 30 mm. The specially designed ultrasound-compatible metalized plastic tip allowed simultaneous imaging during ablation and direct acquisition of TSI data for tissue ablation temperatures. Postprocessing analysis showed a first-order correlation between TSI and temperature, permitting early development temperature-time relationships at specific myocardial ablation sites. Conclusions Multifunctional forward-looking ML-CMUT ICE catheters, with simultaneous intracardiac guidance, ultrasound imaging, and RFA, may offer a new means to improve interventional ablation procedures. PMID:22298868

  2. Real-time model-based image reconstruction with a prior calculated database for electrical capacitance tomography

    Science.gov (United States)

    Rodriguez Frias, Marco A.; Yang, Wuqiang

    2017-04-01

    Image reconstruction for electrical capacitance tomography is a challenging task due to the severely underdetermined nature of the inverse problem. A model-based algorithm tackles this problem by reducing the number of unknowns to be calculated from the limited number of independent measurements. The conventional model-based algorithm is implemented with a finite element method to solve the forward problem at each iteration and can produce good results. However, it is time-consuming and hence the algorithm can be used for off-line image reconstruction only. In this paper, a solution to this limitation is proposed. The model-based algorithm is implemented with a database containing a set of prior solved forward problems. In this way, the time required to perform image reconstruction is drastically reduced without sacrificing accuracy, and real-time image reconstruction achieved with up to 100 frames s‑1. Further enhancement in speed may be accomplished by implementing the reconstruction algorithm in a parallel processing general purpose graphics process unit.

  3. Development of Image Reconstruction Algorithms in electrical Capacitance Tomography; Desarrollo de algoritmos de reconstruccion de imagenes en tomografia de capacitancia electrica

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Marron, J. L.; Alberdi Primicia, J.; Barcala Riveira, J. M.

    2007-12-28

    The Electrical Capacitance Tomography (ECT) has not obtained a good development in order to be used at industrial level. That is due first to difficulties in the measurement of very little capacitances (in the range of femto farads) and second to the problem of reconstruction on- line of the images. This problem is due also to the small numbers of electrodes (maximum 16), that made the usual algorithms of reconstruction has many errors. In this work it is described a new purely geometrical method that could be used for this purpose. (Author) 4 refs.

  4. Capacitive label reader

    Science.gov (United States)

    Arlowe, H. Duane

    1985-01-01

    A capacitive label reader includes an outer ring transmitting portion, an inner ring transmitting portion, and a plurality of insulated receiving portions. A label is the mirror-image of the reader except that identifying portions corresponding to the receiving portions are insulated from only one of two coupling elements. Positive and negative pulses applied, respectively, to the two transmitting rings biased a CMOS shift register positively to either a 1 or 0 condition. The output of the CMOS may be read as an indication of the label.

  5. Fort Monroe Historic Image Report

    Science.gov (United States)

    2010-08-01

    ERDC/CERL SR-10-8 August 2010 Fort Monroe Historic Image Report Adam Smith , Megan Weaver Tooker, Meghan Roller, and Rory Nicholson Construction... Adam Smith was the CERL Project Manager and lead architectural historian, Megan Weaver Tooker was the lead land- scape architect, and Meghan Roller...5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S). Adam Smith , Megan Weaver Tooker, Meghan Roller and Rory Nicholson 5d. PROJECT NUMBER 5e. TASK

  6. Reconstruction of electrical capacitance tomography images based on fast linearized alternating direction method of multipliers for two-phase flow system

    Institute of Scientific and Technical Information of China (English)

    Chongkun Xia; Chengli Su⁎; Jiangtao Cao; Ping Li

    2016-01-01

    Electrical capacitance tomography (ECT) has been applied to two-phase flow measurement in recent years. Image reconstruction algorithms play an important role in the successful applications of ECT. To solve the il-posed and nonlinear inverse problem of ECT image reconstruction, a new ECT image reconstruction method based on fast lin-earized alternating direction method of multipliers (FLADMM) is proposed in this paper. On the basis of theoretical analysis of compressed sensing (CS), the data acquisition of ECT is regarded as a linear measurement process of permittivity distribution signal of pipe section. A new measurement matrix is designed and L1 regularization method is used to convert ECT inverse problem to a convex relaxation problem which contains prior knowledge. A new fast alternating direction method of multipliers which contained linearized idea is employed to minimize the objective function. Simulation data and experimental results indicate that compared with other methods, the quality and speed of reconstructed images are markedly improved. Also, the dynamic experimental results in-dicate that the proposed algorithm can fulfil the real-time requirement of ECT systems in the application.

  7. Novel RF-MEMS capacitive switching structures

    NARCIS (Netherlands)

    Rottenberg, X.; Jansen, H.; 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 capacitan

  8. MRI Reporter Genes for Noninvasive Molecular Imaging

    Directory of Open Access Journals (Sweden)

    Caixia Yang

    2016-05-01

    Full Text Available Magnetic resonance imaging (MRI is one of the most important imaging technologies used in clinical diagnosis. Reporter genes for MRI can be applied to accurately track the delivery of cell in cell therapy, evaluate the therapy effect of gene delivery, and monitor tissue/cell-specific microenvironments. Commonly used reporter genes for MRI usually include genes encoding the enzyme (e.g., tyrosinase and β-galactosidase, the receptor on the cells (e.g., transferrin receptor, and endogenous reporter genes (e.g., ferritin reporter gene. However, low sensitivity limits the application of MRI and reporter gene-based multimodal imaging strategies are common including optical imaging and radionuclide imaging. These can significantly improve diagnostic efficiency and accelerate the development of new therapies.

  9. Development and Implementation of 3-D, High Speed Capacitance Tomography for Imaging Large-Scale, Cold-Flow Circulating Fluidized Bed

    Energy Technology Data Exchange (ETDEWEB)

    Marashdeh, Qussai [Tech4imaging LLC, Columbus, OH (United States)

    2013-02-01

    A detailed understanding of multiphase flow behavior inside a Circulating Fluidized Bed (CFB) requires a 3-D technique capable of visualizing the flow field in real-time. Electrical Capacitance Volume Tomography (ECVT) is a newly developed technique that can provide such measurements. The attractiveness of the technique is in its low profile sensors, fast imaging speed and scalability to different section sizes, low operating cost, and safety. Moreover, the flexibility of ECVT sensors enable them to be designed around virtually any geometry, rendering them suitable to be used for measurement of solid flows in exit regions of the CFB. Tech4Imaging LLC has worked under contract with the U.S. Department of Energy's National Energy Technology Laboratory (DOE NETL) to develop an ECVT system for cold flow visualization and install it on a 12 inch ID circulating fluidized bed. The objective of this project was to help advance multi-phase flow science through implementation of an ECVT system on a cold flow model at DOE NETL. This project has responded to multi-phase community and industry needs of developing a tool that can be used to develop flow models, validate computational fluid dynamics simulations, provide detailed real-time feedback of process variables, and provide a comprehensive understating of multi-phase flow behavior. In this project, a complete ECVT system was successfully developed after considering different potential electronics and sensor designs. The system was tested at various flow conditions and with different materials, yielding real-time images of flow interaction in a gas-solid flow system. The system was installed on a 12 inch ID CFB of the US Department of Energy, Morgantown Labs. Technical and economic assessment of Scale-up and Commercialization of ECVT was also conducted. Experiments conducted with larger sensors in conditions similar to industrial settings are very promising. ECVT has also the potential to be developed for imaging multi

  10. Intelligent image retrieval based on radiology reports

    Energy Technology Data Exchange (ETDEWEB)

    Gerstmair, Axel; Langer, Mathias; Kotter, Elmar [University Medical Center Freiburg, Department of Diagnostic Radiology, Freiburg (Germany); Daumke, Philipp; Simon, Kai [Averbis GmbH, Freiburg (Germany)

    2012-12-15

    To create an advanced image retrieval and data-mining system based on in-house radiology reports. Radiology reports are semantically analysed using natural language processing (NLP) techniques and stored in a state-of-the-art search engine. Images referenced by sequence and image number in the reports are retrieved from the picture archiving and communication system (PACS) and stored for later viewing. A web-based front end is used as an interface to query for images and show the results with the retrieved images and report text. Using a comprehensive radiological lexicon for the underlying terminology, the search algorithm also finds results for synonyms, abbreviations and related topics. The test set was 108 manually annotated reports analysed by different system configurations. Best results were achieved using full syntactic and semantic analysis with a precision of 0.929 and recall of 0.952. Operating successfully since October 2010, 258,824 reports have been indexed and a total of 405,146 preview images are stored in the database. Data-mining and NLP techniques provide quick access to a vast repository of images and radiology reports with both high precision and recall values. Consequently, the system has become a valuable tool in daily clinical routine, education and research. (orig.)

  11. Intelligent image retrieval based on radiology reports.

    Science.gov (United States)

    Gerstmair, Axel; Daumke, Philipp; Simon, Kai; Langer, Mathias; Kotter, Elmar

    2012-12-01

    To create an advanced image retrieval and data-mining system based on in-house radiology reports. Radiology reports are semantically analysed using natural language processing (NLP) techniques and stored in a state-of-the-art search engine. Images referenced by sequence and image number in the reports are retrieved from the picture archiving and communication system (PACS) and stored for later viewing. A web-based front end is used as an interface to query for images and show the results with the retrieved images and report text. Using a comprehensive radiological lexicon for the underlying terminology, the search algorithm also finds results for synonyms, abbreviations and related topics. The test set was 108 manually annotated reports analysed by different system configurations. Best results were achieved using full syntactic and semantic analysis with a precision of 0.929 and recall of 0.952. Operating successfully since October 2010, 258,824 reports have been indexed and a total of 405,146 preview images are stored in the database. Data-mining and NLP techniques provide quick access to a vast repository of images and radiology reports with both high precision and recall values. Consequently, the system has become a valuable tool in daily clinical routine, education and research. Radiology reports can now be analysed using sophisticated natural language-processing techniques. Semantic text analysis is backed by terminology of a radiological lexicon. The search engine includes results for synonyms, abbreviations and compositions. Key images are automatically extracted from radiology reports and fetched from PACS. Such systems help to find diagnoses, improve report quality and save time.

  12. 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.

  13. Imaging in plague. Case report

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, A.J.; Rodriguez, A.A.; Turnbull, G.L.; Reeves, T.A.

    1987-09-01

    An 8-year-old boy presented with elevated temperature, malaise, hepatosplenomegaly, mesenteric adenitis, and septic shock. Cultures of biopsied abdominal lymph nodes as well as the blood grew Yersinia pestes. The boy's condition improved after two weeks of chloramphenicol and cefotaxime (Claforan). Two days after stopping intravenous antibiotic therapy, the patient again became febrile and complained of abdominal pain. Abdominal imaging with /sup III/In labeled leukocytes did not show any abnormalities, however, /sup 67/Ge-citrate scintigraphy demonstrated an abnormal focus of increased radiopharmaceutical uptake within a confluence of necrosed lymph nodes with the right upper quadrant of the abdomen. In addition, abnormal /sup 67/Ga uptake was seen within the left hip region. Correlative imaging with computed tomography is also presented.

  14. Quantum Capacitance in Topological Insulators

    Science.gov (United States)

    Xiu, Faxian; Meyer, Nicholas; Kou, Xufeng; He, Liang; Lang, Murong; Wang, Yong; Yu, Xinxin; Fedorov, Alexei V.; Zou, Jin; Wang, Kang L.

    2012-01-01

    Topological insulators show unique properties resulting from massless, Dirac-like surface states that are protected by time-reversal symmetry. Theory predicts that the surface states exhibit a quantum spin Hall effect with counter-propagating electrons carrying opposite spins in the absence of an external magnetic field. However, to date, the revelation of these states through conventional transport measurements remains a significant challenge owing to the predominance of bulk carriers. Here, we report on an experimental observation of Shubnikov-de Haas oscillations in quantum capacitance measurements, which originate from topological helical states. Unlike the traditional transport approach, the quantum capacitance measurements are remarkably alleviated from bulk interference at high excitation frequencies, thus enabling a distinction between the surface and bulk. We also demonstrate easy access to the surface states at relatively high temperatures up to 60 K. Our approach may eventually facilitate an exciting exploration of exotic topological properties at room temperature. PMID:22993694

  15. Reporter Gene Imaging in Therapy and Diagnosis

    Directory of Open Access Journals (Sweden)

    Pritha Ray, Abhijit De

    2012-01-01

    Full Text Available Noninvasive molecular imaging using reporter genes is a relatively recent field in biomedical imaging that holds great promises for disease diagnosis and therapy. As modern medicine is moving towards personalized medicine, targeted biomolecule based therapies is gaining popularity that requires careful and systematic validation. Reporter genes have emerged as important generalizable tools to overcome the shortcomings of direct evaluation of individual biomolecules and are being applied in various fields such as cell therapy, stem cell therapy, immune therapy, viral gene delivery through optical, radionuclide, magnetic resonance imaging techniques. New approaches to image protein-protein interaction, protein phosphorylation, protein folding that are crucial parameters for theranostic study using reporter genes are being developed. All these new technologies and relevant preclinical and clinical researches will determine the success of early detection and personalized therapy in the future.

  16. Breast imaging and reporting data system (BIRADS): magnetic resonance imaging.

    Science.gov (United States)

    Tardivon, Anne A; Athanasiou, Alexandra; Thibault, Fabienne; El Khoury, Carl

    2007-02-01

    This article reviews the technical aspects and interpretation criteria in breast MR imaging based on the first edition of breast imaging and reporting data system (BIRADS) published by the American College of Radiology (ACR) in 2003. In a second article, practical cases will be proposed for training the readers. The major aims of using this lexicon are: first to use a logical and standardized description of MR lesions, secondly to obtain a structured MR report with a clear final impression (BIRADS assessment categories), and thirdly to help comparison between different clinical studies based on similar breast MRI terminology.

  17. Breast imaging and reporting data system (BIRADS): Magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Tardivon, Anne A. [Department of Radiology, Institut Curie, 26 rue d' Ulm, 75248 Paris Cedex 05 (France)]. E-mail: anne.tardivon@curie.net; Athanasiou, Alexandra [Department of Radiology, Institut Curie, 26 rue d' Ulm, 75248 Paris Cedex 05 (France); Thibault, Fabienne [Department of Radiology, Institut Curie, 26 rue d' Ulm, 75248 Paris Cedex 05 (France); El Khoury, Carl [Department of Radiology, Institut Curie, 26 rue d' Ulm, 75248 Paris Cedex 05 (France)

    2007-02-15

    This article reviews the technical aspects and interpretation criteria in breast MR imaging based on the first edition of breast imaging and reporting data system (BIRADS) published by the American College of Radiology (ACR) in 2003. In a second article, practical cases will be proposed for training the readers. The major aims of using this lexicon are: first to use a logical and standardized description of MR lesions, secondly to obtain a structured MR report with a clear final impression (BIRADS assessment categories), and thirdly to help comparison between different clinical studies based on similar breast MRI terminology.

  18. Molecular Imaging with Activatable Reporter Systems

    Directory of Open Access Journals (Sweden)

    Gang Niu, Xiaoyuan Chen

    2012-01-01

    Full Text Available Molecular imaging is a newly emerged multiple disciplinary field that aims to visualize, characterize and quantitatively measure biological processes at cellular and molecular levels in humans and other living systems. A reporter gene is a piece of DNA encoding reporter protein, which presents as a readily measurable phenotype that can be distinguished easily from the background of endogenous protein. After being transferred into cells of organ systems (transgenes, the reporter gene can be utilized to visualize transcriptional and posttranscriptional regulation of gene expression, protein-protein interactions, or trafficking of proteins or cells in living subjects. Herein, we review previous classification of reporter genes and regroup the reporter gene based imaging as basic, inducible and activatable, based on the regulation of reporter gene transcription and post-translational modification of reporter proteins. We then focus on activatable reporters, in which the signal can be activated at the posttranslational level for visualizing protein-protein interactions, protein phosphorylation or tertiary structure changes. The applications of several types of activatable reporters will also be summarized. We conclude that activatable reporter imaging can benefit both basic biomedical research and drug development.

  19. ``Zeptofarad'' (10-21 F) resolution capacitance sensor for scanning capacitance microscopy

    Science.gov (United States)

    Tran, T.; Oliver, D. R.; Thomson, D. J.; Bridges, G. E.

    2001-06-01

    We describe a sensor for use in a scanning capacitance microscope (SCM) that is capable of "zeptofarad" (10-21 F) capacitance measurement resolution in a 1 Hz bandwidth with a peak-to-peak sense voltage on the probe tip of no more than 300 mV. This sensitivity is based on experimental data and simulation results that are in excellent agreement. The complete sensor incorporates an oscillator (phase locked to a 10 MHz crystal oscillator), a coupled transmission line resonator, an amplifier, and a peak detector. The resonator is fabricated from copper-clad, low-loss dielectric material and its size is such that it is easily incorporated with a scanning probe microscope. The sensor's use in the SCM enables capacitance resolution that has not previously been possible while retaining the instrumental advantages of imaging at low sense voltages. The performance of this sensor is discussed and compared to alternative scanning capacitance microscopy methodologies.

  20. Ion channels, phosphorylation and mammalian sperm capacitation.

    Science.gov (United States)

    Visconti, Pablo E; Krapf, Dario; de la Vega-Beltrán, José Luis; Acevedo, Juan José; Darszon, Alberto

    2011-05-01

    Sexually reproducing animals require an orchestrated communication between spermatozoa and the egg to generate a new individual. Capacitation, a maturational complex phenomenon that occurs in the female reproductive tract, renders spermatozoa capable of binding and fusing with the oocyte, and it is a requirement for mammalian fertilization. Capacitation encompasses plasma membrane reorganization, ion permeability regulation, cholesterol loss and changes in the phosphorylation state of many proteins. Novel tools to study sperm ion channels, image intracellular ionic changes and proteins with better spatial and temporal resolution, are unraveling how modifications in sperm ion transport and phosphorylation states lead to capacitation. Recent evidence indicates that two parallel pathways regulate phosphorylation events leading to capacitation, one of them requiring activation of protein kinase A and the second one involving inactivation of ser/thr phosphatases. This review examines the involvement of ion transporters and phosphorylation signaling processes needed for spermatozoa to achieve capacitation. Understanding the molecular mechanisms leading to fertilization is central for societies to deal with rising male infertility rates, to develop safe male gamete-based contraceptives and to preserve biodiversity through better assisted fertilization strategies.

  1. Ion channels, phosphorylation and mammalian sperm capacitation

    Institute of Scientific and Technical Information of China (English)

    Pablo E Visconti; Dario Krapf; José Luis de la Vega-Beltrán; Juan José Acevedo; Alberto Darszon

    2011-01-01

    Sexually reproducing animals require an orchestrated communication between spermatozoa and the egg to generate a new individual. Capacitation, a maturational complex phenomenon that occurs in the female reproductive tract, renders spermatozoa capable of binding and fusing with the oocyte, and it is a requirement for mammalian fertilization. Capacitation encompasses plasma membrane reorganization, ion permeability regulation, cholesterol loss and changes in the phosphorylation state of many proteins. Novel tools to study sperm ion channels, image intracellular ionic changes and proteins with better spatial and temporal resolution, are unraveling how modifications in sperm ion transport and phosphorylation states lead to capacitation. Recent evidence indicates that two parallel pathways regulate phosphorylation events leading to capacitation, one of them requiring activation of protein kinase A and the second one involving inactivation of ser/thr phosphatases. This review examines the involvement of ion transporters and phosphorylation signaling processes needed for spermatozoa to achieve capacitation. Understanding the molecular mechanisms leading to fertilization is central for societies to deal with rising male infertility rates, to develop safe male gamete-based contraceptives and to preserve biodiversity through better assisted fertilization strategies.

  2. Image reconstruction algorithm based on NSSN for Electrical Capacitance Tomography%类支集神经网络在ECT图像重建中的研究与应用

    Institute of Scientific and Technical Information of China (English)

    李岩; 冯莉; 朱艳丹; 张礼勇

    2011-01-01

    Aiming at improvement of image reconstruction algorithm in 12-Electrical Capacitance Tomography system,this paper conducts an experimental study on closed containers gas/solid two phase flow,which mainly depend on the stability and the speed of image reconstruction algorithm.To keep the stability of solving process and the computational performance, the image reconstruction algorithm based on a new set of neural network types supported algorithm (NSSN) is first applied to the ECT image reconstruction system.Large-scale training of neural network algorithm puts forward a slow sub-division of the network enhancement.The system uses 12-electrode capacitance tomography system for gas-solid flow tube closure data detection, the use of the improved neural network algorithm for image reconstruction.The obtained experimental results fully show that the image reconstruction method has high precision imaging,computing speed and so on.This method can simplify the use of neural network structure, reducing the size of neurons for image reconstruction of electrical capacitance tomography system and providing a new way of thinking.%以12电极电容阵列传感器ECT系统为背景,从图像重建的稳定性和速度两方面对密闭容器中气-固两相流场的图像重建算法优化进行实验室研究.将基于新型类支集函数的神经网络算法(NSSN),应用于ECT系统图像重建算法中,使得图像重建算法的求解过程稳定并具有良好的计算性能.针对大规模神经网络算法训练速度较慢的问题提出了划分子网络的改进方法.通过对封闭管道的气固两相流进行数据检测,并采用改进后的神经网络算法进行图像重建,实验结果验证了改进后的方法弥补了大规模神经网络运算速度慢的不足,可以简化神经网络的结构,减少神经元的规模,为电容层析成像系统图像重建提供了新的思路.

  3. Steerable Capacitive Proximity Sensor

    Science.gov (United States)

    Jenstrom, Del T.; Mcconnell, Robert L.

    1994-01-01

    Steerable capacitive proximity sensor of "capaciflector" type based partly on sensing units described in GSC-13377 and GSC-13475. Position of maximum sensitivity adjusted without moving sensor. Voltage of each driven shield adjusted separately to concentrate sensing electric field more toward one side or other.

  4. 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 ar

  5. MOS Capacitance-Voltage Characteristics:V.Methods to Enhance the Trapping Capacitance

    Institute of Scientific and Technical Information of China (English)

    揭斌斌; 薩支唐

    2012-01-01

    Low-frequency and High-frequency Capacitance-Voltage (C-V) curves of Silicon Metal-Oxide-Semiconductor Capacitors,showing electron and hole trapping at shallow-level dopant and deep-level generationrecombination-trapping impurities,are presented to illustrate the enhancement of the giant trapping capacitances by physical means via device and circuit designs,in contrast to chemical means via impurity characteristics previously reported.Enhancement is realized by masking the electron or/and hole storage capacitances to make the trapping capacitances dominant at the terminals.Device and materials properties used in the computed CV curves are selected to illustrate experimental realizations for fundamental trapping parameter characterizations and for electrical and optical signal processing applications.

  6. Capacitance enhancement via electrode patterning

    Science.gov (United States)

    Ho, Tuan A.; Striolo, Alberto

    2013-11-01

    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.

  7. Capacitance enhancement via electrode patterning

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Tuan A.; Striolo, Alberto, E-mail: a.striolo@ucl.ac.uk [School of Chemical, Biological and Materials Engineering, The University of Oklahoma, Norman, Oklahoma 73019 (United States); Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom)

    2013-11-28

    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.

  8. Capacitive deionization of seawater

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J.C.; Fix, D.V.; Mack, G.V. [and others

    1995-10-01

    Capacitive deionization with carbon aerogel electrodes is an efficient and economical new process for removing salt and impurities from water. Carbon aerogel is a material that enables the successful purification of water because of its high surface area, optimum pore size, and low electrical resistivity. The electrodes are maintained at a potential difference of about one volt; ions are removed from the water by the imposed electrostatic field and retained on the electrode surface until the polarity is reversed. The capacitive deionization of water with a stack of carbon aerogel electrodes has been successfully demonstrated. The overall process offers advantages when compared to conventional water-purification methods, requiring neither pumps, membranes, distillation columns, nor thermal heaters. Consequently, the overall process is both robust and energy efficient. The current state of technology development, commercialization, and potential applications of this process are reviewed.

  9. Induced Charge Capacitive Deionization

    CERN Document Server

    Rubin, S; Biesheuvel, P M; Bercovici, M

    2016-01-01

    We demonstrate the phenomenon of induced-charge capacitive deionization (ICCDI) that occurs around a porous and conducting particle immersed in an electrolyte, under the action of an external electrostatic field. The external electric field induces an electric dipole in the porous particle, leading to capacitive charging of its volume by both cations and anions at opposite poles. This regime is characterized both by a large RC charging time and a small electrochemical charge relaxation time, which leads to rapid and significant deionization of ionic species from a volume which is on the scale of the particle. We show by theory and experiment that the transient response around a cylindrical particle results in spatially non-uniform charging and non-steady growth of depletion regions which emerge around the particle's poles. Potentially, ICCDI can be useful in applications where fast concentration changes of ionic species are required over large volumes.

  10. 15 CFR 743.3 - Thermal imaging camera reporting.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Thermal imaging camera reporting. 743... REPORTING § 743.3 Thermal imaging camera reporting. (a) General requirement. Exports of thermal imaging cameras must be reported to BIS as provided in this section. (b) Transactions to be reported. Exports...

  11. Markov chain Monte Carlo(MCMC)based image reconstruction algorithm for electrical capacitance tomography%基于MCMC方法的电容成像图像重构算法

    Institute of Scientific and Technical Information of China (English)

    叶佳敏; 彭黎辉

    2012-01-01

    研究基于概率统计的电容成像图像重构算法,以马尔科夫随机场的方式给出介电常数分布的先验概率,利用电容成像(electrical capacitance tomography,ECT)线性模型得到似然函数,通过马尔科夫链蒙特卡罗(Markov chain Monte Carlo,MCMC)方法对介电常数分布的后验概率密度进行采样,马尔科夫链的转移核利用Metropolis-Hastings方法得到,结合嵌套迭代提高计算效率.仿真结果表明,嵌套迭代-MCMC方法在正则化参数设置合适的条件下,可以得到较好的图像质量,基于MCMC方法图像重构算法为解决ECT图像重构问题提供一种新思路.%An image reconstruction algorithm based on statistical model for electrical capacitance tomography (ECT) is proposed. The prior probability and likelihood function are obtained using multi-level Markov random field and ECT liner model. Using MCMC sampling, the posterior distribution of permittivity is estimated. Meanwhile, nested iteration is introduced to improve the calculation efficiency. Simulation results show that the nested iteration-MCMC can enhance the calculation speed significantly and provide reconstruction images with higher quality if a proper regu-larization parameter is used. The MCMC based method provides a new way for ECT image reconstruction.

  12. Capacitance of circular patch resonator

    Energy Technology Data Exchange (ETDEWEB)

    Miano, G.; Verolino, L. [Dip. di Ingegneria Elettrica, Ist. Nazionale di Fisica Nucleare, Naples (Italy); Panariello, G. [Dip. di Ingegneria Elettronica, Naples (Italy); Vaccaro, V.G. [Ist. Nazionale di Fisica Nucleare, Naples (Italy). Dipt. di Scienze Fisiche

    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.

  13. Small space object imaging : LDRD final report.

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, Mark R.; Valley, Michael T.; Kearney, Sean Patrick

    2009-10-01

    We report the results of an LDRD effort to investigate new technologies for the identification of small-sized (mm to cm) debris in low-earth orbit. This small-yet-energetic debris presents a threat to the integrity of space-assets worldwide and represents significant security challenge to the international community. We present a nonexhaustive review of recent US and Russian efforts to meet the challenges of debris identification and removal and then provide a detailed description of joint US-Russian plans for sensitive, laser-based imaging of small debris at distances of hundreds of kilometers and relative velocities of several kilometers per second. Plans for the upcoming experimental testing of these imaging schemes are presented and a preliminary path toward system integration is identified.

  14. Magnetosphere imager science definition team interim report

    Science.gov (United States)

    Armstrong, T. P.; Johnson, C. L.

    1995-01-01

    For three decades, magnetospheric field and plasma measurements have been made by diverse instruments flown on spacecraft in may different orbits, widely separated in space and time, and under various solar and magnetospheric conditions. Scientists have used this information to piece together an intricate, yet incomplete view of the magnetosphere. A simultaneous global view, using various light wavelengths and energetic neutral atoms, could reveal exciting new data nd help explain complex magnetospheric processes, thus providing a clear picture of this region of space. This report documents the scientific rational for such a magnetospheric imaging mission and provides a mission concept for its implementation.

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

    Institute of Scientific and Technical Information of China (English)

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

    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.

  16. Evaluation of a Capacitance Scaling System

    Science.gov (United States)

    2007-01-01

    2009 at 11:32 from IEEE Xplore . Restrictions apply. Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the...Downloaded on January 30, 2009 at 11:32 from IEEE Xplore . Restrictions apply. 2162 IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, VOL. 56, NO. 6...30, 2009 at 11:32 from IEEE Xplore . Restrictions apply. AVRAMOV-ZAMUROVIC et al.: EVALUATION OF A CAPACITANCE SCALING SYSTEM 2163 measured to vary by

  17. Arctic Clouds Infrared Imaging Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, J. A. [Montana State Univ., Bozeman, MT (United States)

    2016-03-01

    The Infrared Cloud Imager (ICI), a passive thermal imaging system, was deployed at the North Slope of Alaska site in Barrow, Alaska, from July 2012 to July 2014 for measuring spatial-temporal cloud statistics. Thermal imaging of the sky from the ground provides high radiometric contrast during night and polar winter when visible sensors and downward-viewing thermal sensors experience low contrast. In addition to demonstrating successful operation in the Arctic for an extended period and providing data for Arctic cloud studies, a primary objective of this deployment was to validate novel instrument calibration algorithms that will allow more compact ICI instruments to be deployed without the added expense, weight, size, and operational difficulty of a large-aperture onboard blackbody calibration source. This objective was successfully completed with a comparison of the two-year data set calibrated with and without the onboard blackbody. The two different calibration methods produced daily-average cloud amount data sets with correlation coefficient = 0.99, mean difference = 0.0029 (i.e., 0.29% cloudiness), and a difference standard deviation = 0.054. Finally, the ICI instrument generally detected more thin clouds than reported by other ARM cloud products available as of late 2015.

  18. Comparison of piezoresistive and capacitive ultrasonic transducers

    Science.gov (United States)

    Neumann, John J.; Greve, David W.; Oppenheim, Irving J.

    2004-07-01

    MEMS ultrasonic transducers for flaw detection have heretofore been built as capacitive diaphragm-type devices. A diaphragm forms a moveable electrode, placed at a short gap from a stationary electrode, and diaphragm movement has been detected by capacitance change. Although several research teams have successfully demonstrated that technology, the detection of capacitance change is adversely affected by stray and parasitic capacitances, limiting the sensitivity of such transducers and typically requiring relatively large diaphragm areas. We describe the design and fabrication of what to our knowledge is the first CMOS-MEMS ultrasonic phased array transducer using piezoresistive strain sensing. Piezoresistors have been patterned within the diaphragms, and diaphragm movement creates bending strain which is detected by a bridge circuit, for which conductor losses will be less significant. The prospective advantage of such piezoresistive transducers is that sufficient sensitivity may be achieved with very small diaphragms. We compare transducer response under fluid-coupled ultrasonic excitation and report the experimental gauge factor for the piezoresistors. We also discuss the phased array performance of the transducer in sensing the direction of an incoming wave.

  19. Negative capacitance in multidomain ferroelectric superlattices

    Science.gov (United States)

    Zubko, Pavlo; Wojdeł, Jacek C.; Hadjimichael, Marios; Fernandez-Pena, Stéphanie; Sené, Anaïs; Luk'Yanchuk, Igor; Triscone, Jean-Marc; Íñiguez, Jorge

    2016-06-01

    The stability of spontaneous electrical polarization in ferroelectrics is fundamental to many of their current applications, which range from the simple electric cigarette lighter to non-volatile random access memories. Research on nanoscale ferroelectrics reveals that their behaviour is profoundly different from that in bulk ferroelectrics, which could lead to new phenomena with potential for future devices. As ferroelectrics become thinner, maintaining a stable polarization becomes increasingly challenging. On the other hand, intentionally destabilizing this polarization can cause the effective electric permittivity of a ferroelectric to become negative, enabling it to behave as a negative capacitance when integrated in a heterostructure. Negative capacitance has been proposed as a way of overcoming fundamental limitations on the power consumption of field-effect transistors. However, experimental demonstrations of this phenomenon remain contentious. The prevalent interpretations based on homogeneous polarization models are difficult to reconcile with the expected strong tendency for domain formation, but the effect of domains on negative capacitance has received little attention. Here we report negative capacitance in a model system of multidomain ferroelectric-dielectric superlattices across a wide range of temperatures, in both the ferroelectric and paraelectric phases. Using a phenomenological model, we show that domain-wall motion not only gives rise to negative permittivity, but can also enhance, rather than limit, its temperature range. Our first-principles-based atomistic simulations provide detailed microscopic insight into the origin of this phenomenon, identifying the dominant contribution of near-interface layers and paving the way for its future exploitation.

  20. Optimal pricing of capacitated networks

    NARCIS (Netherlands)

    Grigoriev, Alexander; Loon, van Joyce; Sitters, René; Uetz, Marc

    2009-01-01

    We address the algorithmic complexity of a profit maximization problem in capacitated, undirected networks. We are asked to price a set of $m$ capacitated network links to serve a set of $n$ potential customers. Each customer is interested in purchasing a network connection that is specified by a si

  1. 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....

  2. CAPACITIVE TOMOGRAPHY FOR THE LOCATION OF PLASTIC PIPE

    Energy Technology Data Exchange (ETDEWEB)

    Brian J. Huber

    2002-07-15

    Throughout the utility industry, there is high interest in subsurface imaging of plastic, ceramic, and metallic objects because of the cost, reliability, and safety benefits available in avoiding impacts with the existing infrastructure and in reducing inappropriate excavations. Industry interest in locating plastic pipe has resulted in funding available for the development of technologies that enable this imaging. Gas Technology Institute (GTI) proposes to develop a compact and inexpensive capacitive tomography imaging sensor that takes the form of a flat plate or flexible mat that can be placed on the ground to image objects embedded in the soil. A compact, low-cost sensor that can image objects through soil could be applied to multiple operations and will produce a number of cost savings for the gas industry. In a stand-alone mode, it could be used to survey an area prior to excavation. The technology would improve the accuracy and reliability of any operation that involves excavation by locating or avoiding buried objects. An accurate subsurface image of an area will enable less costly keyhole excavations and other cost-saving techniques. Ground penetrating radar (GPR) has been applied to this area with limited success. Radar requires a high-frequency carrier to be injected into the soil: the higher the frequency, the greater the image resolution. Unfortunately, high-frequency radio waves are more readily absorbed by soil. Also, high-frequency operation raises the cost of the associated electronics. By contrast, the capacitive tomography sensor uses low frequencies with a multiple-element antenna to obtain good resolution. Low-frequency operation lowers the cost of the associated electronics while improving depth of penetration. The objective of this project is to combine several existing techniques in the area of capacitive sensing to quickly produce a demonstrable prototype. The sensor itself will take the form of a flat array of electrodes that can be

  3. Circuit analysis and simulation of an ultrahigh-frequency capacitance sensor for scanning capacitance microscopy

    Science.gov (United States)

    Yang, Jing; Postula, A.; Bialkowski, M.

    2004-03-01

    Quantitative two-dimensional dopant profiling tools are urgently needed for nowadays semiconductor industry. Scanning Capacitance Microscopy (SCM) holds most promise to become such a tool. The key component of SCM is an ultra high frequency (UHF) capacitance sensor. The output of the sensor has been approximately regarded as dC/dV, the derivative of the capacitance between the SCM tip and the sample versus the applied bias voltage. The SCM dopant profiling involves extracting the dopant profile from the SCM signal using analytic or numerical simulation models of Metal-Oxide-Semiconductor physics. To achieve a quantitative SCM dopant profiling, the operational principle of the whole SCM measurement has to be well understood and correctly included in those models. Recently, experimental evidences show the SCM signal is dramatically affected by many SCM experimental factors, including the behavior of the UHF capacitance sensor. However, till now, very little research has been reported on the behavior of the sensor in SCM measurement of semiconductors. In this paper, we derive an analytic expression of the sensor output, a circuit simulation model of the sensor is established using Advanced Design System 2003, and the dependences of the sensor output on the SCM operational factors are simulated.

  4. Automated Image Data Exploitation Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Kamath, C; Poland, D; Sengupta, S K; Futterman, J H

    2004-01-26

    The automated production of maps of human settlement from recent satellite images is essential to detailed studies of urbanization, population movement, and the like. Commercial satellite imagery is becoming available with sufficient spectral and spatial resolution to apply computer vision techniques previously considered only for laboratory (high resolution, low noise) images. In this project, we extracted the boundaries of human settlements from IKONOS 4-band and panchromatic images using spectral segmentation together with a form of generalized second-order statistics and detection of edges and corners.

  5. [Integrating information about imaging biomarkers into structured radiology reports].

    Science.gov (United States)

    Pomar-Nadal, A; Pérez-Castillo, C; Alberich-Bayarri, A; García-Martí, G; Sanz Requena, R; Martí-Bonmatí, L

    2013-01-01

    Imaging biomarkers describe objective characteristics that are related to normal biological processes, diseases, or the response to treatment. They enable radiologists to incorporate into their reports data about structure, function, and tissue components. With the aim of taking maximum advantage of the quantification of medical images, we present a procedure to integrate imaging biomarkers into radiological reports, bringing the new paradigm of personal medicine closer to radiological workflow. In this manner, the results of quantification can complement traditional radiological diagnosis, improving accuracy and the evaluation of the efficacy of treatments. A more personalized, standardized, structured radiological report should include quantitative analyses to complement conventional qualitative reporting in selected cases.

  6. Bioenergetics of Mammalian Sperm Capacitation

    Directory of Open Access Journals (Sweden)

    Alessandra Ferramosca

    2014-01-01

    Full Text Available 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.

  7. Unified capacitance modelling of MOSFETs

    Science.gov (United States)

    Johannessen, O. G.; Fjeldly, T. A.; Ytterdal, T.

    1994-01-01

    A unified physics based capacitance model for MOSFETs suitable for implementation in circuit simulators is presented. This model is based on the charge conserving, so-called Meyer-like approach proposed by Turchetti et al., and utilizes a unified charge control model to assure a continuous description of the MOSFET capacitances both above and below threshold. The capacitances associated with the model are comparable to those of the well-known BSIM model in the above-threshold regime, but it is more precise in the description of near-threshold and subthreshold behaviour. Moreover, the discontinuities at the transitions between the various regimes of operation are removed. The present modelling scheme was implemented in our circuit simulator AIM-Spice, and simulations of the dynamic behaviour of various demanding benchmark circuits clearly reveal its superiority over simulations using the simple Meyer model.

  8. Micromachined capacitive transducer arrays for intravascular ultrasound

    Science.gov (United States)

    Degertekin, F. Levent; Guldiken, R. Oytun; Karaman, Mustafa

    2005-01-01

    Intravascular ultrasound (IVUS) imaging has become an essential imaging modality for the effective diagnosis and treatment of cardiovascular diseases during the past decade enabled by innovative applications of piezoelectric transducer technology. The limitations in the manufacture and performance of the same piezoelectric transducers have also impeded the improvement of IVUS for emerging clinically important applications such as forward viewing arrays for guiding interventions and high resolution imaging of arterial structure such as vulnerable plaque and fibrous cap, and also implementation of techniques such as harmonic imaging of the tissue and of the contrast agents. Capacitive micromachined ultrasonic transducer (CMUT) technology shows great potential for transforming IVUS not only to satisfy these clinical needs but also to open up possibilities for low-cost imaging devices integrated to therapeutic tools. We have developed manufacturing processes with a maximum process temperature of 250°C to build CMUTs on the same silicon chip with integrated electronics. Using these processes we fabricated CMUT arrays suitable for forward viewing IVUS in the 10-20MHz range. We characterized these array elements in terms of pulse-echo response, radiation pattern measurements and demonstrated its volumetric imaging capabilities on various imaging targets.

  9. Comparison of Algebraic Reconstruction Technique and Simultaneous Iterative Reconstruction Technique in Electrical Capacitance Tomography Image Reconstruction%代数重建和同步迭代重建在电容层析成像中的比较研究

    Institute of Scientific and Technical Information of China (English)

    陈夏; 胡红利; 高享想; 方天驰

    2011-01-01

    针对电容层析成像技术(ECT)中的逆问题--图像重建算法的非线性和病态性问题,以12电极电容层析成像系统为对象,研究了代数重建算法(ART)与同步迭代重建算法(SIRT).分别对仿真电容值和实测电容值进行图像重建的实验验证,从成像效果、相对误差及重建时间3个方面对这两种算法进行了评估与分析.结果表明,ART算法和SIRT算法均能有效地实现ECT图像重建,其中SIRT算法能够在100次迭代内达到高精度,在收敛速度和成像效果上更具有优势.%To solve the nonlinear and ill-posed inverse problems in electrical capacitance tomography(ECT) , algebraic reconstruction technique (ART) and simultaneous iterative reconstruction technique (SIRT) were put forward to meet the requirement of image reconstruction. 12-electrode ECT system was set up to acquire real measurement capacitances under annular flow and stratified flow. The imaging results of the two algorithms in simulated capacitances and measured capacitances were evaluated and analyzed respectively for the imaging quality, relative error and reconstruction time. The experiments indicated that ART and SIRT for the presented ECT system perform effectively. Compared with ART, the convergence rate and the quality of SIRT are more advantageous with higher accuracy within 100 iterations.

  10. Water desalination via capacitive deionization

    NARCIS (Netherlands)

    Suss, M.E.; Porada, S.; Sun, X.; Biesheuvel, P.M.; Yoon, J.; Presser, V.

    2015-01-01

    Capacitive deionization (CDI) is an emerging technology for the facile removal of charged ionic species from aqueous solutions, and is currently being widely explored for water desalination applications. The technology is based on ion electrosorption at the surface of a pair of electrically charg

  11. Water desalination via capacitive deionization

    NARCIS (Netherlands)

    Suss, M.E.; Porada, S.; Sun, X.; Biesheuvel, P.M.; Yoon, J.; Presser, V.

    2015-01-01

    Capacitive deionization (CDI) is an emerging technology for the facile removal of charged ionic species from aqueous solutions, and is currently being widely explored for water desalination applications. The technology is based on ion electrosorption at the surface of a pair of electrically charg

  12. 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.

  13. Interfacial capacitance effects in magnetic tunneling junctions

    CERN Document Server

    Landry, G; Du, J; Xiao, J Q

    2001-01-01

    We have investigated the AC transport properties of magnetic tunnel junctions (MTJ) in order to characterize interfacial properties. One such property is interfacial charge accumulation, which leads to a voltage drop in the electrodes of the MTJ and the measured capacitance differing from the geometrical capacitance. Through measurement of capacitance spectra, we have extracted an interfacial capacitance of 16 mu F/cm sup 2 per interface and a screening length of 0.55 A for FeNi electrodes.

  14. Feasibility study of simultaneous capacitance detection during STM of silicon

    Science.gov (United States)

    Kim, Hyun; Dwyer, Kevin; Pomeroy, Joshua

    2015-03-01

    We are examining the feasibility of capacitance detection during STM to image buried metal nanostructures in silicon. As the hydrogen STM lithography for quantum information enables us to fabricate the atomically precise devices such as single atom qubits, the accurate alignment of metal contacts such as electrodes to the buried nanostructures on the surface becomes very challenging. Using SCM with STM gives benefits to locate the buried nanostructures and image the surface morphology simultaneously.

  15. Cerenkov ring imaging detector development: Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Aston, D.; Bienz, T.; Bird, F.; Dasu, S.; Dunwoodie, W.; Hallewell, G.; Kawahara, H.; Kwon, Y.; Leith, D.; Ratcliff, B.

    1988-10-01

    We present recent progress on the construction and testing of the first drift boxes and single electron detectors as they come from the production line. These detectors will be used for particle identification using the Ring Imaging technique in the SLD experiment at SLAC. Various experimental results are presented, including single electron pulse height measurements as a function of gas gain, detector gating capability, uniformity of response across the wire plane, charge division performance of a single electron signal, average pulse shape and its comparison with predicted shape, and cross-talk. 14 refs., 11 figs.

  16. Advanced Imaging Catheter: Final Project Report

    Energy Technology Data Exchange (ETDEWEB)

    Krulevitch, P; Colston, B; DaSilva, L; Hilken, D; Kluiwstra, J U; Lee, A P; London, R; Miles, R; Schumann, D; Seward, K; Wang, A

    2001-07-20

    Minimally invasive surgery (MIS) is an approach whereby procedures conventionally performed with large and potentially traumatic incisions are replaced by several tiny incisions through which specialized instruments are inserted. Early MIS, often called laparoscopic surgery, used video cameras and laparoscopes to visualize and control the medical devices, which were typically cutting or stapling tools. More recently, catheter-based procedures have become a fast growing sector of all surgeries. In these procedures, small incisions are made into one of the main arteries (e.g. femoral artery in the thigh), and a long thin hollow tube is inserted and positioned near the target area. The key advantage of this technique is that recovery time can be reduced from months to a matter of days. In the United States, over 700,000 catheter procedures are performed annually representing a market of over $350 million. Further growth in this area will require significant improvements in the current catheter technology. In order to effectively navigate a catheter through the tortuous vessels of the body, two capabilities must exist: imaging and positioning. In most cases, catheter procedures rely on radiography for visualization and manual manipulation for positioning of the device. Radiography provides two-dimensional, global images of the vasculature and cannot be used continuously due to radiation exposure to both the patient and physician. Intravascular ultrasound devices are available for continuous local imaging at the catheter tip, but these devices cannot be used simultaneously with therapeutic devices. Catheters are highly compliant devices, and manipulating the catheter is similar to pushing on a string. Often, a guide wire is used to help position the catheter, but this procedure has its own set of problems. Three characteristics are used to describe catheter maneuverability: (1) pushability -- the amount of linear displacement of the distal end (inside body) relative to

  17. Gemini Planet Imager: Preliminary Design Report

    Energy Technology Data Exchange (ETDEWEB)

    Macintosh, B

    2007-05-10

    For the first time in history, direct and indirect detection techniques have enabled the exploration of the environments of nearby stars on scales comparable to the size of our solar system. Precision Doppler measurements have led to the discovery of the first extrasolar planets, while high-contrast imaging has revealed new classes of objects including dusty circumstellar debris disks and brown dwarfs. The ability to recover spectrophotometry for a handful of transiting exoplanets through secondary-eclipse measurements has allowed us to begin to study exoplanets as individual entities rather than points on a mass/semi-major-axis diagram and led to new models of planetary atmospheres and interiors, even though such measurements are only available at low SNR and for a handful of planets that are automatically those most modified by their parent star. These discoveries have galvanized public interest in science and technology and have led to profound new insights into the formation and evolution of planetary systems, and they have set the stage for the next steps--direct detection and characterization of extrasolar Jovian planets with instruments such as the Gemini Planet Imager (GPI). As discussed in Volume 1, the ability to directly detect Jovian planets opens up new regions of extrasolar planet phase space that in turn will inform our understanding of the processes through which these systems form, while near-IR spectra will advance our understanding of planetary physics. Studies of circumstellar debris disks using GPI's polarimetric mode will trace the presence of otherwise-invisible low-mass planets and measure the build-up and destruction of planetesimals. To accomplish the science mission of GPI will require a dedicated instrument capable of achieving contrast of 10{sup -7} or more. This is vastly better than that delivered by existing astronomical AO systems. Currently achievable contrast, about 10{sup -5} at separations of 1 arc second or larger, is

  18. Capacitive Power Transfer

    Science.gov (United States)

    2010-12-15

    PD3S160 C = 38 pF, VF = 0.58 V @ 0.7 A Table 6: Suggested LED driver components. 28 KVCORF KT vf f KI Measured Current it IOUT IREF + Loop Filter VCO ...presented in Figure 15. A voltage controlled oscillator ( VCO ) with gain KV CO in Hertz per volt is used to synthesize the frequency f (ω = 2πf) that...error signal is approximately 50µs. The simulated loop gain is 60. The simulated VCO frequency is 3.3 MHz. The discrepancy between the reported error

  19. A Novel Reporting System to Improve Accuracy in Appendicitis Imaging

    Science.gov (United States)

    Godwin, Benjamin D.; Drake, Frederick T.; Simianu, Vlad V.; Shriki, Jabi E.; Hippe, Daniel S.; Dighe, Manjiri; Bastawrous, Sarah; Cuevas, Carlos; Flum, David; Bhargava, Puneet

    2015-01-01

    OBJECTIVE The purpose of this study was to ascertain if standardized radiologic reporting for appendicitis imaging increases diagnostic accuracy. MATERIALS AND METHODS We developed a standardized appendicitis reporting system that includes objective imaging findings common in appendicitis and a certainty score ranging from 1 (definitely not appendicitis) through 5 (definitely appendicitis). Four radiologists retrospectively reviewed the preoperative CT scans of 96 appendectomy patients using our reporting system. The presence of appendicitis-specific imaging findings and certainty scores were compared with final pathology. These comparisons were summarized using odds ratios (ORs) and the AUC. RESULTS The appendix was visualized on CT in 89 patients, of whom 71 (80%) had pathologically proven appendicitis. Imaging findings associated with appendicitis included appendiceal diameter (odds ratio [OR] = 14 [> 10 vs appendicitis. In this initially indeterminate group, using the standardized reporting system, radiologists assigned higher certainty scores (4 or 5) in 21 of the 28 patients with appendicitis (75%) and lower scores (1 or 2) in five of the seven patients without appendicitis (71%) (AUC = 0.90; p = 0.001). CONCLUSION Standardized reporting and grading of objective imaging findings correlated well with postoperative pathology and may decrease the number of CT findings reported as indeterminate for appendicitis. Prospective evaluation of this reporting system on a cohort of patients with clinically suspected appendicitis is currently under way. PMID:26001230

  20. Muscular cysticercosis: Case report and imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Olmo, Neide Regina Simoes; Fiorio, Ulysses Ferreira; Clemente, Marcel Andreazza, E-mail: neideolmo@yahoo.com.br [Clinica Mult Imagem, Santos, SP (Brazil); Bastos, Eder Amaral [Universidade Metropolitana de Santos (UNIMES), Santos, SP (Brazil); Mendes, Gustavo Gomes [AC Camargo Cancer Center, Sao Paulo, SP (Brazil)

    2016-11-15

    Cysticercosis is a parasitic disease caused by a worm of the Cestoda class. The most prevalent form affects the nervous system. This case report is from a 78-year old female patient evaluated at Clinica Mult Imagem, in the city of Santos, Brazil, who presented a form of the disease that differed from the classic neurocysticercosis, in this case muscular cysticercosis. This and other forms of manifestation justify further studies to ensure adequate recognition, diagnosis and treatment of this parasitic disease. (author)

  1. Imaging findings of cerebellopontine angle cistern melanocytoma : a case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Mi; Choi, Jin Ok; Joo, Myung Jin [Presbyterian Medical Center, Chunju (Korea, Republic of)

    2000-03-01

    Because melanocytes are found throughout the leptomeninges, primary melanotic pigmented tumors such as pigmented meningioma, malignant melanoma, melanoblastosis, and melanocytoma can arise from this region. Melanocytomas have been described in the literature as isodense or hyperdense compared with brain parenchyme, as seen on noncontrast-enhanced CT, and as showing relatively homogeneous enhancement MR imaging demonstrates a high signal on T1-weighted images, and an iso to hypointense signal on T2-weighted images. We report the imaging findings of a melanocytoma that showed hyperdense attenuation on precontrast CT with homogeneous enhancement and hyperintense signal intensity on T1-weighted images and dark signal intensity enhancement on T2-weighted images, and also review the literature. (author)

  2. Muscular cysticercosis: Case report and imaging findings

    Directory of Open Access Journals (Sweden)

    Neide Regina Simões Olmo

    Full Text Available Summary Cysticercosis is a parasitic disease caused by a worm of the Cestoda class. The most prevalent form affects the nervous system. This case report is from a 78-year-old female patient evaluated at Clínica Mult Imagem, in the city of Santos, Brazil, who presented a form of the disease that differed from the classic neurocysticercosis, in this case muscular cysticercosis. This and other forms of manifestation justify further studies to ensure adequate recognition, diagnosis and treatment of this parasitic disease.

  3. SPECT imaging of cardiac reporter gene expression in living rabbits

    Institute of Scientific and Technical Information of China (English)

    LIU Ying; LAN Xiaoli; ZHANG Liang; WU Tao; JIANG Rifeng; ZHANG Yongxue

    2009-01-01

    This work is to demonstrate feasibility of imaging the expression of herpes simplex virus 1-thymidine ki-nase (HSV1-tk) reporter gene in rabbits myocardium by using the reporter probe 131I-2'-fluoro-2'-deoxy-1-β-D- arabi-nofuranosyl-5-iodouracil (131I-FIAU) and SPECT. Rabbits of the study group received intramyocardial injection of Ad5-tk and control group received aseptic saline injection. Two sets of experiments were performed on the study group. Rabbits of the 1st set were injected with 131I-FIAU 600 μCi at Day 2 after intramyocardial transfection of Ad5-tk in 1×109, 5×108, 1×108, 5×107 and 1×107 pfu, and heart SPECT imaging was done at different hours. Rabbits of the 2nd were transferred various titers of Ad5-tk (1×109, 5×108, 1×108, 5×107, 1×107 pfu) to determine the threshold and optimal viral titer needed for detection of gene expression. Two days later, 131I-FIAU was injected and heart SPECT imaging was performed at 6, 24 and 48 h, before killing them for gamma counting of the hearts. Reverse tran-scription-polymerase chain reaction (RT-PCR) was used to verify the transferred HSV1-tk gene expression. Semi-quantitative analysis derived of region of interest (ROI) of SPECT images and RT-PCR images was performed and the relationship of SPECT images with ex vivo gamma counting and mRNA level were evaluated. SPECT images conformed 131I-FIAU accumulation in rabbits injected with Ad5-tk in the anterolateral wall. The optimal images qual-ity was obtained at 24~48 h for different viral titers. The highest radioactivity in the focal myocardium was seen at 6 h, and then declined with time. The threshold was 5×107 pfu of virus titer. The result could be set better in 1~5×108 pfu by SPECT analysis and gamma counting. ROI-derived semi-quantitative study on SPECT images correlated well with ex vivo gamma counting and mRNA levels from RT-PCR analysis. The HSV1-tk/131I-FIAU reporter gene/reporter probe system is feasible for cardiac SPECT reporter gene imaging

  4. Imaging Diagnosis of Neonatal Anemia: Report of Two Unusual Etiologies

    Directory of Open Access Journals (Sweden)

    Shabnam Bhandari Grover

    2013-01-01

    Full Text Available Anemia in neonatal period is rare, with the common causes being Rh and ABO blood group incompatibility, hemorrhagic disease of newborn, congenital hemolytic anemia, hemoglobinopathies, and TORCH (toxoplasmosis, rubella, cytomegalovirus, herpes virus infections. Congenital leukemia and infantile osteopetrosis (OP are among the rare causes of neonatal anemia. A review of the literature shows approximately 200 reported cases of congenital leukemia. Articles describing the imaging features of congenital leukemia are still rarer. Infantile OP, another rare disorder with a reported incidence of 1 in 250,000 has characteristic imaging features, which are diagnostic of the disease. We report a case each, of two rare diseases: Congenital leukemia and infantile osteopetrosis. Additionally, our report highlights the radiological and imaging features of congenital leukemia and infantile OP and their crucial role in arriving at an early diagnosis.

  5. High bandwidth on-chip capacitive tuning of microtoroid resonators

    CERN Document Server

    Baker, Christopher G; McAuslan, David L; Sheridan, Eoin; Bowen, Warwick P

    2016-01-01

    We report on the design, fabrication and characterization of silica microtoroid based cavity opto-electromechanical systems (COEMS). Electrodes patterned onto the microtoroid resonators allow for rapid capacitive tuning of the optical whispering gallery mode resonances while maintaining their ultrahigh quality factor, enabling applications such as efficient radio to optical frequency conversion, optical routing and switching applications.

  6. A Low-Cost Universal Integrated Interface for Capacitive Sensors

    NARCIS (Netherlands)

    Heidary, A.

    2010-01-01

    This thesis reports the results of research on features, options and limitations of low-cost, high-performance, universal integrated interface for capacitive sensors. It concerns development-driven research, where the objectives of the research focus upon possible realization and application of the

  7. Stray capacitances in the watt balance operation: electrostatic forces

    CERN Document Server

    Quagliotti, Danilo

    2014-01-01

    In a watt balance, stray capacitances exist between the coil and the magnet. Since the electric current flowing in the coil originates a difference between the coil and magnet electric-potentials, their electrostatic interactions must be taken into account. This paper reports the results of a finite element analysis of the forces acting on the coil.

  8. Stray capacitances in the watt balance operation: electrostatic forces

    DEFF Research Database (Denmark)

    Quagliotti, Danilo; Mana, G.

    2014-01-01

    In a watt balance, stray capacitances exist between the coil and the magnet. Since the electric current flowing in the coil creates a difference in electric potentials between the coil and magnet, their electrostatic interactions must be taken into account. This paper reports the results of a fin...

  9. Capacitance variation measurement method with a continuously variable measuring range for a micro-capacitance sensor

    Science.gov (United States)

    Lü, Xiaozhou; Xie, Kai; Xue, Dongfeng; Zhang, Feng; Qi, Liang; Tao, Yebo; Li, Teng; Bao, Weimin; Wang, Songlin; Li, Xiaoping; Chen, Renjie

    2017-10-01

    Micro-capacitance sensors are widely applied in industrial applications for the measurement of mechanical variations. The measurement accuracy of micro-capacitance sensors is highly dependent on the capacitance measurement circuit. To overcome the inability of commonly used methods to directly measure capacitance variation and deal with the conflict between the measurement range and accuracy, this paper presents a capacitance variation measurement method which is able to measure the output capacitance variation (relative value) of the micro-capacitance sensor with a continuously variable measuring range. We present the principles and analyze the non-ideal factors affecting this method. To implement the method, we developed a capacitance variation measurement circuit and carried out experiments to test the circuit. The result shows that the circuit is able to measure a capacitance variation range of 0–700 pF linearly with a maximum relative accuracy of 0.05% and a capacitance range of 0–2 nF (with a baseline capacitance of 1 nF) with a constant resolution of 0.03%. The circuit is proposed as a new method to measure capacitance and is expected to have applications in micro-capacitance sensors for measuring capacitance variation with a continuously variable measuring range.

  10. Imaging systems for biomedical applications. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Radparvar, M.

    1995-06-06

    Many of the activities of the human body manifest themselves by the presence of a very weak magnetic field outside the body, a field that is so weak that an ultra-sensitive magnetic sensor is needed for specific biomagnetic measurements. Superconducting QUantum Interference Devices (SQUIDs) are extremely sensitive detectors of magnetic flux and have been used extensively to detect the human magnetocardiogram, and magnetoencephalogram. and other biomagnetic signals. In order to utilize a SQUID as a magnetometer, its transfer characteristics should be linearized. This linearization requires extensive peripheral electronics, thus limiting the number of SQUID magnetometer channels in a practical system. The proposed digital SQUID integrates the processing circuitry on the same cryogenic chip as the SQUID magnetometer and eliminates the sophisticated peripheral electronics. Such a system is compact and cost effective, and requires minimal support electronics. Under a DOE-sponsored SBIR program, we designed, simulated, laid out, fabricated, evaluated, and demonstrated a digital SQUID magnetometer. This report summarizes the accomplishments under this program and clearly demonstrates that all of the tasks proposed in the phase II application were successfully completed with confirmed experimental results.

  11. Redox regulation of mammalian sperm capacitation

    Directory of Open Access Journals (Sweden)

    Cristian O′Flaherty

    2015-01-01

    Full Text Available Capacitation is a series of morphological and metabolic changes necessary for the spermatozoon to achieve fertilizing ability. One of the earlier happenings during mammalian sperm capacitation is the production of reactive oxygen species (ROS that will trigger and regulate a series of events including protein phosphorylation, in a time-dependent fashion. The identity of the sperm oxidase responsible for the production of ROS involved in capacitation is still elusive, and several candidates are discussed in this review. Interestingly, ROS-induced ROS formation has been described during human sperm capacitation. Redox signaling during capacitation is associated with changes in thiol groups of proteins located on the plasma membrane and subcellular compartments of the spermatozoon. Both, oxidation of thiols forming disulfide bridges and the increase on thiol content are necessary to regulate different sperm proteins associated with capacitation. Reducing equivalents such as NADH and NADPH are necessary to support capacitation in many species including humans. Lactate dehydrogenase, glucose-6-phospohate dehydrogenase, and isocitrate dehydrogenase are responsible in supplying NAD (P H for sperm capacitation. Peroxiredoxins (PRDXs are newly described enzymes with antioxidant properties that can protect mammalian spermatozoa; however, they are also candidates for assuring the regulation of redox signaling required for sperm capacitation. The dysregulation of PRDXs and of enzymes needed for their reactivation such as thioredoxin/thioredoxin reductase system and glutathione-S-transferases impairs sperm motility, capacitation, and promotes DNA damage in spermatozoa leading to male infertility.

  12. Contrast distortion induced by modulation voltage in scanning capacitance microscopy

    Science.gov (United States)

    Chang, M. N.; Hu, C. W.; Chou, T. H.; Lee, Y. J.

    2012-08-01

    With a dark-mode scanning capacitance microscopy (SCM), we directly observed the influence of SCM modulation voltage (MV) on image contrasts. For electrical junctions, an extensive modulated area induced by MV may lead to noticeable changes in the SCM signal phase and intensity, resulting in a narrowed junction image and a broadened carrier concentration profile. This contrast distortion in SCM images may occur even if the peak-to-peak MV is down to 0.3 V. In addition, MV may shift the measured electrical junction depth. The balance of SCM signals components explain these MV-induced contrast distortions.

  13. pn-Junction Delineation in Si Devices Using Scanning Capacitance Spectroscopy

    Science.gov (United States)

    Edwards, Hal

    2000-03-01

    The scanning capacitance microscope (SCM) is a carrier-sensitive imaging tool based upon the well-known scanning-probe microscope (SPM). Scanning capacitance spectroscopy (SCS) is a new way to utilize an SCM to delineate pn junctions in Si devices. SCS produces two-dimensional pn-junction maps that show features as small as 10 nm. SCS also provides an estimate of the pn-junction depletion width and hence the doping level near the pn junction. We report SCS measurements of deep-submicron field-effect transistors, showing the source-drain extender profile. We show SCM and SCS data in a failure-analysis application, in which we determined the cause of a leaky field-effect transistor. SCM and SCS are powerful tools for Si bipolar transistors, in which the doping-related structures are quite complex. We show microscopic evidence of the narrow-emitter effect, and image the width of the pn junction to explain an electric field-induced hot-carrier reliability issue. We show a comparison of top-view and cross-sectional SCS measurements of nwell-nwell shallow-trench isolation structures, to reveal the effects of photoresist scumming in sub-design-rule isolation widths. We show initial results on a method to delineate constant-potential contours within the depletion region. We discuss the limits to our present understanding of SCM and SCS and some potential sources of error.

  14. Dual Cryogenic Capacitive Density Sensor

    Science.gov (United States)

    Youngquist, Robert; Mata, Carlos; Vokrot, Peter; Cox, Robert

    2009-01-01

    A dual cryogenic capacitive density sensor has been developed. The device contains capacitive sensors that monitor two-phase cryogenic flow density to within 1% accuracy, which, if temperature were known, could be used to determine the ratio of liquid to gas in the line. Two of these density sensors, located a known distance apart, comprise the sensor, providing some information on the velocity of the flow. This sensor was constructed as a proposed mass flowmeter with high data acquisition rates. Without moving parts, this device is capable of detecting the density change within a two-phase cryogenic flow more than 100 times a second. Detection is enabled by a series of two sets of five parallel plates with stainless steel, cryogenically rated tubing. The parallel plates form the two capacitive sensors, which are measured by electrically isolated digital electronics. These capacitors monitor the dielectric of the flow essentially the density of the flow and can be used to determine (along with temperature) the ratio of cryogenic liquid to gas. Combining this information with the velocity of the flow can, with care, be used to approximate the total two-phase mass flow. The sensor can be operated at moderately high pressures and can be lowered into a cryogenic bath. The electronics have been substantially improved over the older sensors, incorporating a better microprocessor, elaborate ground loop protection and noise limiting circuitry, and reduced temperature sensitivity. At the time of this writing, this design has been bench tested at room temperature, but actual cryogenic tests are pending

  15. 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.

  16. Compact monolithic capacitive discharge unit

    Science.gov (United States)

    Roesler, Alexander W.; Vernon, George E.; Hoke, Darren A.; De Marquis, Virginia K.; Harris, Steven M.

    2007-06-26

    A compact monolithic capacitive discharge unit (CDU) is disclosed in which a thyristor switch and a flyback charging circuit are both sandwiched about a ceramic energy storage capacitor. The result is a compact rugged assembly which provides a low-inductance current discharge path. The flyback charging circuit preferably includes a low-temperature co-fired ceramic transformer. The CDU can further include one or more ceramic substrates for enclosing the thyristor switch and for holding various passive components used in the flyback charging circuit. A load such as a detonator can also be attached directly to the CDU.

  17. Photoacoustic imaging using genetically encoded reporters: a review

    Science.gov (United States)

    Brunker, Joanna; Yao, Junjie; Laufer, Jan; Bohndiek, Sarah E.

    2017-07-01

    Genetically encoded contrast in photoacoustic imaging (PAI) is complementary to the intrinsic contrast provided by endogenous absorbing chromophores such as hemoglobin. The use of reporter genes expressing absorbing proteins opens the possibility of visualizing dynamic cellular and molecular processes. This is an enticing prospect but brings with it challenges and limitations associated with generating and detecting different types of reporters. The purpose of this review is to compare existing PAI reporters and signal detection strategies, thereby offering a practical guide, particularly for the nonbiologist, to choosing the most appropriate reporter for maximum sensitivity in the biological and technological system of interest.

  18. MIST Final Report: Multi-sensor Imaging Science and Technology

    Energy Technology Data Exchange (ETDEWEB)

    Lind, Michael A.; Medvick, Patricia A.; Foley, Michael G.; Foote, Harlan P.; Heasler, Patrick G.; Thompson, Sandra E.; Nuffer, Lisa L.; Mackey, Patrick S.; Barr, Jonathan L.; Renholds, Andrea S.

    2008-03-15

    The Multi-sensor Imaging Science and Technology (MIST) program was undertaken to advance exploitation tools for Long Wavelength Infra Red (LWIR) hyper-spectral imaging (HSI) analysis as applied to the discovery and quantification of nuclear proliferation signatures. The program focused on mitigating LWIR image background clutter to ease the analyst burden and enable a) faster more accurate analysis of large volumes of high clutter data, b) greater detection sensitivity of nuclear proliferation signatures (primarily released gasses) , and c) quantify confidence estimates of the signature materials detected. To this end the program investigated fundamental limits and logical modifications of the more traditional statistical discovery and analysis tools applied to hyperspectral imaging and other disciplines, developed and tested new software incorporating advanced mathematical tools and physics based analysis, and demonstrated the strength and weaknesses of the new codes on relevant hyperspectral data sets from various campaigns. This final report describes the content of the program and the outlines the significant results.

  19. A High-Stability Capacitance Sensor System and Its Evaluation

    Science.gov (United States)

    2008-12-01

    15:45 from IEEE Xplore . Restrictions apply. Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of...45 from IEEE Xplore . Restrictions apply. AVRAMOV-ZAMUROVIC AND LEE: HIGH-STABILITY CAPACITANCE SENSOR SYSTEM AND ITS EVALUATION 957 Fig. 4...Authorized licensed use limited to: US Naval Academy. Downloaded on May 13, 2009 at 15:45 from IEEE Xplore . Restrictions apply. 958 IEEE TRANSACTIONS

  20. Repetitive Imaging of Reporter Gene Expression in the Lung

    Directory of Open Access Journals (Sweden)

    Jean-Christophe Richard

    2003-10-01

    Full Text Available Positron emission tomographic imaging is emerging as a powerful technology to monitor reporter transgene expression in the lungs and other organs. However, little information is available about its usefulness for studying gene expression over time. Therefore, we infected 20 rats with a replication-deficient adenovirus containing a fusion gene encoding for a mutant Herpes simplex virus type-1 thymidine kinase and an enhanced green fluorescent protein. Five additional rats were infected with a control virus. Pulmonary gene transfer was performed via intratracheal administration of vector using a surfactant-based method. Imaging was performed 4–6 hr, and 4, 7, and 10 days after gene transfer, using 9-(4-[18F]-fluoro-3-hydroxymethylbutylguanine, an imaging substrate for the mutant kinase. Lung tracer uptake assessed with imaging was moderately but significantly increased 4–6 hr after gene transfer, was maximal after 4 days, and was no longer detectable by 10 days. The temporal pattern of transgene expression measured ex vivo with in vitro assays of thymidine kinase activity and green fluorescent protein was similar to imaging. In conclusion, positron emission tomography is a reliable new tool to evaluate the onset and duration of reporter gene expression noninvasively in the lungs of intact animals.

  1. Myocardial Perfusion Spect Imaging in Dextrocardia: A Case Report

    Directory of Open Access Journals (Sweden)

    Semra Özdemir

    2013-08-01

    Full Text Available The myocardial perfusion scintigraphy acquisition and analysis present some technical differences in the rare dextrocardia cases. Here we report a case of a 38 year-old woman with dextrocardia who had been applied myocardial perfusion scintigraphy. Presented case showed that the thoracic and abdominal organs had a mirror image with situs inversus totalis type dextrocardia. The incidence of coronary heart disease and life span of people with situs inversus totalis are the same as the normal population. So we may apply myocardial perfusion scintigraphy to this patient group. The current case is presented in order to remind the special applications of myocardial perfusion SPECT imaging in patients with dextrocardia.

  2. 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...

  3. Characterization of Textile-Insulated Capacitive Biosensors

    Directory of Open Access Journals (Sweden)

    Charn Loong Ng

    2017-03-01

    Full Text Available Capacitive biosensors are an emerging technology revolutionizing wearable sensing systems and personal healthcare devices. They are capable of continuously measuring bioelectrical signals from the human body while utilizing textiles as an insulator. Different textile types have their own unique properties that alter skin-electrode capacitance and the performance of capacitive biosensors. This paper aims to identify the best textile insulator to be used with capacitive biosensors by analysing the characteristics of 6 types of common textile materials (cotton, linen, rayon, nylon, polyester, and PVC-textile while evaluating their impact on the performance of a capacitive biosensor. A textile-insulated capacitive (TEX-C biosensor was developed and validated on 3 subjects. Experimental results revealed that higher skin-electrode capacitance of a TEX-C biosensor yields a lower noise floor and better signal quality. Natural fabric such as cotton and linen were the two best insulating materials to integrate with a capacitive biosensor. They yielded the lowest noise floor of 2 mV and achieved consistent electromyography (EMG signals measurements throughout the performance test.

  4. Energy-Efficient Capacitive-Sensor Interfaces

    NARCIS (Netherlands)

    Tan, Z.

    2013-01-01

    This thesis describes the theory, design and realization of energy-efficient capacitive-sensor interfaces that are dedicated to energy-constrained applications. The goal of this work is to explore energy-efficient capacitive-sensor interface design techniques both at the system and the circuit level

  5. hNIS-IRES-eGFP Dual Reporter Gene Imaging

    Directory of Open Access Journals (Sweden)

    Jiantu Che

    2005-04-01

    Full Text Available The human and rodent sodium iodide symporters (NIS have recently been cloned and are being investigated as potential therapeutic and reporter genes. We have extended this effort by constructing an internal ribosomal entry site (IRES-linked human NIS (hNIS-enhanced green fluorescent protein (eGFP hybrid reporter gene for both nuclear and optical imaging. A self-inactivating retroviral vector, termed pQCNIG, containing hNIS-IRES-eGFP dual reporter gene, driven by a constitutive CMV promoter, was constructed and used to generate RG2-pQCNIG cells and RG2-pQCNIG tumors. 131I-iodide and 99mTcO4-pertechnetate accumulation studies plus fluorescence microscopy and intensity assays were performed in vitro, and gamma camera imaging studies in RG2-pQCNIG and RG2 tumor-bearing athymic rats were performed. RG2-pQCNIG cells expressed high levels of hNIS protein and showed high intensity of eGFP fluorescence compared with RG2 wild-type cells. RG2-pQCNIG cells accumulated Na131I and 99mTcO4– to a 50:1 and a 170:1 tissue/medium ratio at 10 min, compared with 0.8:1.2 tissue/medium ratio in wild-type RG2 cells. A significant correlation between radiotracer accumulation and eGFP fluorescence intensity was demonstrated. RG2-pQCNIG and RG2 tumors were readily differentiated by in vivo gamma camera imaging; radiotracer uptake increased in RG2-pQCNIG but declined in RG2 tumors over the 50-min imaging period. Stomach and thyroid were the major organs of radionuclide accumulation. The IRES-linked hNIS-eGFP dual reporter gene is functional and stable in transduced RG2-pQCNIG cells. Optical and nuclear imaging of tumors produced from these cell lines provides the opportunity to monitor tumor growth and response to therapy. These studies indicate the potential for a wider application of hNIS reporter imaging and translation into patient studies using radioisotopes that are currently available for human use for both SPECT and PET imaging.

  6. Capacitance Measurement Methods for Integrated Sensor Applications

    Directory of Open Access Journals (Sweden)

    Alireza Hassanzadeh

    2013-09-01

    Full Text Available In this paper different measurement methods that have been used for integrated capacitance measurement are reviewed and their advantage and disadvantages are discussed. For the designers of high accuracy on chip integrated circuits for capacitive sensors, it is important to know which method will provide the best approach for high accuracy, small chip area and power consumption especially for array sensors. These methods include on chip capacitive sensor and transducer measurement techniques that have been implemented for low value capacitance evaluations using CMOS technology. After the best structure is known the designer can optimize the chip for specific application. Voltage mode and current mode, linear and switched mode techniques are reviewed and a useful comparison table comparing all figures of merit including accuracy, range of measurement, chip area, speed and complexity is provided. The provided comparison table can be used as a reference for analog designers in the design of high accuracy integrated capacitive sensor interface

  7. Capacitively-coupled chopper amplifiers

    CERN Document Server

    Fan, Qinwen; Huijsing, Johan H

    2017-01-01

    This book describes the concept and design of the capacitively-coupled chopper technique, which can be used in precision analog amplifiers. Readers will learn to design power-efficient amplifiers employing this technique, which can be powered by regular low supply voltage such as 2V and possibly having a +\\-100V input common-mode voltage input. The authors provide both basic design concepts and detailed design examples, which cover the area of both operational and instrumentation amplifiers for multiple applications, particularly in power management and biomedical circuit designs. Discusses basic working principles and details of implementation for proven designs; Includes a diverse set of applications, along with measurement results to demonstrate the effectiveness of the technique; Explains advantages and drawbacks of the technique, given particular circumstances.

  8. Parameter optimization of temperature field in RF-capacitive hyperthermia

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    To realize a certain target temperature distribution in tumor tissues and avoid over-heating in normal tissues in radio frequency (RF)-capacitive hyperthermia, an objective function and some weight coefficients are introduced. Then using the 2-D finite element method, the electromagnetic and bio-heat transfer equations are solved, and using the genetic algorithm the heating configurations are recursively modified to minimize the objective function. Finally an optimum solution of the expected heating field distribution in hyperthermia is achieved. And with a human heterogeneous tissue model extracted from X-ray CT images, satisfactory optimization results are obtained in the simulations on a biplate RF-capacitive hyperthermia device. This optimization technique for controlling the body temperature field has shown scientific importance and practical values in the research of hyperthermia.

  9. On the interfacial capacitance of an electrolyte at a metallic electrode around zero surface charge

    Science.gov (United States)

    Bari Bhuiyan, Lutful; Lamperski, Stanisław

    2013-03-01

    The behaviour of the capacitance of a planar double layer containing a restricted primitive model electrolyte (equi-sized rigid ions moving in a continuum dielectric) at and around zero surface charge is examined for a polarizable electrode with particular emphasis on a metallic surface. Capacitance results are reported for symmetric valency (1:1) salts encompassing a range of concentrations and temperatures covering both electrolyte solution and ionic liquid regimes. Although the modified Poisson-Boltzmann theory is principally employed, at higher concentrations the theoretical calculations have been supplemented by Monte Carlo simulations. Capacitance anomaly, that is, increase of capacitance with temperature at low temperatures, is seen to occur when the electrode is an insulator with a low dielectric constant or when it is unpolarized. No capacitance anomaly is, however, seen for a metallic electrode with an infinite dielectric constant and in this situation the capacitance increases (a) dramatically at low temperatures (strong coupling) at a given concentration, and (b) as concentration increases at a given temperature. These capacitance trends are consistent with earlier works in the presence or absence of surface polarization and, in particular, the results for a conducting electrode at ionic liquid concentrations are consistent with that recently reported by Loth et al. [Phys. Rev. E, 82, 056102 (2010)]. Overall the theoretical predictions are qualitative to semi-quantitative with the simulations.

  10. Imaging of Isotopically Enhanced Molecular Targeting Agents Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Quong, J N

    2004-02-19

    The goal of this project is to develop experimental and computational protocols to use SIMS to image the chemical composition of biological samples, focusing on optimizing sample preparation protocols and developing multivariate data analysis methods. Our results on sample preparation, molecular imaging, and multivariate analysis have been presented at several meeting abstracts (UCRL151797ABS, UCRL151797ABSREV1, UCRL151426ABS, UCRL201277, UCRL154757). A refereed paper describing our results for sample preparation and molecular imaging of various endogenous biomolecules as well as the mutagen PhIP has been accepted for publication (UCRL-JC-151797). We are also preparing two additional papers describing our multivariate analysis methods to analyze spectral data. As these papers have not been submitted, their content is included in this final report.

  11. Optimal imaging for treaty verification FY2014 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Hilton, Nathan R. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Johnson, William C. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Brubaker, Erik M. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Kupinski, Matthew Alan [Univ. of Arizona, Tucson, AZ (United States); MacGahan, Christopher Jonathan [Univ. of Arizona, Tucson, AZ (United States)

    2014-10-01

    FY2014 technical report of our project funded by DNN R&D that leverages advanced inference methods developed for medical and adaptive imaging to address arms control applications. We seek a method to acquire and analyze imaging data of declared treaty-accountable items without creating an image of those objects or otherwise storing or revealing any classified information. Such a method would avoid the use of classified-information barriers. We present our progress on FY2014 tasks defined in our life-cycle plan. We also describe some future work that is part of the continuation of this project in FY2015 and beyond as part of a venture that joins ours with a related PNNL project.

  12. The Shuttle Imaging Radar B (SIR-B) experiment report

    Science.gov (United States)

    Cimino, Jo Bea; Holt, Benjamin; Richardson, Annie

    1988-01-01

    The primary objective of the SIR-B experiment was to acquire multiple-incidence-angle radar imagery of a variety of Earth's surfaces to better understand the effects of imaging geometry on radar backscatter. A complementary objective was to map extensive regions of particular interest. Under these broad objectives, many specific scientific experiments were defined by the 43 SIR-B Science Team members, including studies in the area of geology, vegetation, radar penetration, oceanography, image analysis, and calibration technique development. Approximately 20 percent of the planned digital data were collected, meeting 40 percent of the scientific objectives. This report is an overview of the SIR-B experiment and includes the science investigations, hardware design, mission scenario, mission operations, events of the actual missions, astronaut participation, data products (including auxiliary data), calibrations, and a summary of the actual coverage. Also included are several image samples.

  13. 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.

  14. 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.

  15. Magnetic resonance imaging of the ductus arteriosus - case report

    Energy Technology Data Exchange (ETDEWEB)

    Yousry, T.; Bacherler, B.; Tiling, R.; Fink, U.; Werdan, K.

    1989-03-01

    In a female patient suffering from renal insufficiency in whom angiography could not be performed, it was possible to confirm the diagnosis of a ductus arteriosus (ductus of Botalli) by magnetic resonance imaging. The present case report shows that it is possible to visualise this congenital heart disease by MRI. This can be of importance especially if angiography cannot be performed (as in this case) because of renal insufficiency or because of contrast medium allergy.

  16. Imaging Diagnosis of Neonatal Anemia: Report of Two Unusual Etiologies

    OpenAIRE

    2013-01-01

    Anemia in neonatal period is rare, with the common causes being Rh and ABO blood group incompatibility, hemorrhagic disease of newborn, congenital hemolytic anemia, hemoglobinopathies, and TORCH (toxoplasmosis, rubella, cytomegalovirus, herpes virus) infections. Congenital leukemia and infantile osteopetrosis (OP) are among the rare causes of neonatal anemia. A review of the literature shows approximately 200 reported cases of congenital leukemia. Articles describing the imaging features of c...

  17. Fluorogen-based reporters for fluorescence imaging: a review

    Science.gov (United States)

    Jullien, Ludovic; Gautier, Arnaud

    2015-12-01

    Fluorescence bioimaging has recently jumped into a new area of spatiotemporal resolution and sensitivity thanks to synergistic advances in both optical physics and probe/biosensor design. This review focuses on the recent development of genetically encodable fluorescent reporters that bind endogenously present or exogenously applied fluorogenic chromophores (so-called fluorogens) and activate their fluorescence. We highlight the innovative engineering and design that gave rise to these new natural and synthetic fluorescent reporters, and describe some of the emerging applications in imaging and biosensing.

  18. Capacitance Variation of Electrolyte-Gated Bilayer Graphene Based Transistors

    Directory of Open Access Journals (Sweden)

    Hediyeh Karimi

    2013-01-01

    Full Text Available Quantum capacitance of electrolyte-gated bilayer graphene field-effect transistors is investigated in this paper. Bilayer graphene has received huge attention due to the fact that an energy gap could be opened by chemical doping or by applying external perpendicular electric field. So, this extraordinary property can be exploited to use bilayer graphene as a channel in electrolyte-gated field-effect transistors. The quantum capacitance of bi-layer graphene with an equivalent circuit is presented, and also based on the analytical model a numerical solution is reported. We begin by modeling the DOS, followed by carrier concentration as a function V in degenerate and nondegenerate regimes. To further confirm this viewpoint, the presented analytical model is compared with experimental data, and acceptable agreement is reported.

  19. Sperm capacitation in the porcine oviduct.

    Science.gov (United States)

    Tienthai, P; Johannisson, A; Rodriguez-Martinez, H

    2004-01-01

    In vitro studies suggests that sperm capacitation occurs in the sperm reservoir (SR) of the pig, with spermatozoa progressing towards the ampullary-isthmic junction (AIJ) around ovulation as a consequence of capacitation/hyperactivation. In contrast, in vivo studies are scarce. Consequently, we determined the degree of capacitation in boar spermatozoa that were retrieved from the SR of sows at well-defined periods of spontaneous standing oestrus, namely pre-, peri- and post-ovulation, using flow cytometry of Merocyanine-540/Yo-Pro-1-loaded spermatozoa. SR-spermatozoa retrieved and incubated in non-capacitating medium (bicarbonate-free mBO [mBO-]) were largely viable (70-85%) and uncapacitated (69-73%), irrespective of the stage of oestrus considered. Those undergoing capacitation were a minor proportion (1-5%) during pre- and peri-ovulation, but they significantly increased (14%) in post-ovulation oestrus. To clarify whether these SR-spermatozoa were able to undergo capacitation under stimuli, sperm aliquots were challenged in vitro either by incubation in a bicarbonate-rich medium (capacitation medium, mBO+), then further in mBO+ with 20% (v/v) of in vivo collected homologous pre-ovulatory isthmic oviductal fluid (IOF), or incubation with hyaluronan (HA, 500 microg/ml). Exposure to mBO+ significantly increased the sub-population of capacitated spermatozoa from the pre- and peri-ovulation SR, indicating that the uncapacitated SR-spermatozoa were responsive to the effector/inducer bicarbonate at levels recorded in peri-ovulatory AIJ/ampulla in vivo. While addition of IOF or HA to SR-spermatozoa incubated in capacitating medium (mBO+) maintained sperm viability without obviously inducing capacitation in pre- or peri-ovulatory SR-spermatozoa, they significantly increased these percentages during post-ovulation, when compared to baseline values of control incubations (mBO-). The results suggest that massive sperm capacitation does not occur in vivo in the porcine SR

  20. 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.

  1. Approaching the theoretical capacitance of graphene through copper foam integrated three-dimensional graphene networks

    DEFF Research Database (Denmark)

    Dey, Ramendra Sundar; Hjuler, Hans Aage; Chi, Qijin

    2015-01-01

    We report a facile and low-cost approach for the preparation of all-in-one supercapacitor electrodes using copper foam (CuF) integrated three-dimensional (3D) reduced graphene oxide (rGO) networks. The binderfree 3DrGO@CuF electrodes are capable of delivering high specific capacitance approaching...... the theoretical capacitance of graphene and exhibiting high charge–discharge cycling stability....

  2. Imaging features of intraosseous ganglia: a report of 45 cases

    Energy Technology Data Exchange (ETDEWEB)

    Williams, H.J.; Davies, A.M.; Allen, G.; Evans, N. [Royal Orthopaedic Hospital, Department of Radiology, Birmingham (United Kingdom); Mangham, D.C. [Royal Orthopaedic Hospital, Department of Pathology, Birmingham (United Kingdom)

    2004-10-01

    The aim of this study is to report the spectrum of imaging findings of intraosseous ganglia (IG) with particular emphasis on the radiographic and magnetic resonance (MR) features. Forty-five patients with a final diagnosis of IG were referred to a specialist orthopaedic oncology service with the presumptive diagnosis of either a primary or secondary bone tumour. The diagnosis was established by histology in 25 cases. In the remainder, the imaging features were considered characteristic and the lesion was stable on follow-up radiographic examination. Radiographs were available for retrospective review in all cases and MR imaging in 29. There was a minor male preponderance with a wide adult age range. Three quarters were found in relation to the weight-bearing long bones of the lower limb, particularly round the knee. On radiographs all were juxta-articular and osteolytic; 74% were eccentric in location, 80% had a sclerotic endosteal margin and 60% of cases showed a degree of trabeculation. Periosteal new bone formation and matrix mineralization were not present. Of the 29 cases that underwent MR imaging, 66% were multiloculated. On T1-weighted images the IG contents were isointense or mildly hypointense in 90% cases. Forty-one per cent of the cases showed a slightly hyperintense rim lining that enhanced with a gadolinium chelate. Thirty-eight per cent were associated with soft tissue extension and 17% with a defect of the adjacent articular cortex. Fifty-five per cent showed surrounding marrow oedema on T2-weighted or STIR images and two cases (7%) a fluid-fluid level prior to any surgical intervention. The authors contend that it is semantics to differentiate between an IG and a degenerate subchondral cyst as, while the initial pathogenesis may vary, the histological endpoint is identical, as are the imaging features apart from the degree of associated degenerative joint disease. IGs, particularly when large, may be mistaken for a bone tumour. Correlation of the

  3. Guideline report. Medical ultrasound imaging: progress and opportunities.

    Science.gov (United States)

    Burns, M

    1989-01-01

    use. Ultrasound is one of the safest and least invasive of any of the imaging modalities. It provides a high diagnostic yield relative to its cost. It is comfortable for the patient and can be performed in almost any setting. The equipment is mobile and is relatively easy to use for most examinations. All of these factors have encouraged its increased use. This report examines trends in the ultrasound field from both a technological and economic standpoint and should help end-users in understanding the potentials of this important imaging modality.

  4. Effect of surface asperities on the capacitances of capacitive RF MEMS switches

    Science.gov (United States)

    Chen, Zhiqiang; Tian, Wenchao; Zhang, Xiaotong

    2017-03-01

    The effects of surface asperities on the up- and down-state capacitances of the capacitive radio frequency (RF) micro electromechanical system (MEMS) switches were studied in this paper based on the single asperity model and statics. The research results demonstrated that surface asperities effects on the up-state capacitance could be neglected, whereas surface asperities must be taken into consideration at the down-state position in the RF MEMS switches because the surface asperities significantly affected the down-state capacitance. The down-state capacitance typically decreased as the root mean square (RMS) roughness and asperity radius increased. The down-state capacitance was approximately 26% of the theoretical value when the RMS roughness was 20 nm, and 32% of the theoretical value when the asperity radius was 100 nm. The experimental results were in good agreement with the simulation results.

  5. Complementary surface charge for enhanced capacitive deionization

    NARCIS (Netherlands)

    Gao, X.; Porada, S.; Omosebi, A.; Liu, K.L.; Biesheuvel, P.M.; Landon, J.

    2016-01-01

    Commercially available activated carbon cloth electrodes are treated using nitric acid and ethylenediamine solutions, resulting in chemical surface charge enhanced carbon electrodes for capacitive deionization (CDI) applications. Surface charge enhanced electrodes are then configured in a CDI cel

  6. 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.

  7. 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.

  8. 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 sens...... 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....

  9. Ring VCO Design with Variable Capacitance XNOR Delay Cell

    Science.gov (United States)

    Kumar, Manoj; Arya, Sandeep; Pandey, Sujata

    2015-12-01

    This paper presents the new designs of voltage controlled oscillator (VCO) with three transistors XNOR gate as variable capacitive load. Design of three, five and seven stage VCO have been reported using single ended ring topology. CMOS inverter based delay cell is modified with addition of XNOR capacitive load. Output frequency has been controlled by applied voltage to variable capacitive load. Control voltage of VCO has been varied from 1.3 to 2.1 V. Three stage VCO provides output frequency variation in the range of 3.52-3.34 GHz with power consumption variation from 0.81 to 1.76 mW. Five stage VCO shows frequency variation from 2.06 to 1.98 GHz with power consumption varying from 1.35 to 2.94 mW. Moreover, frequency of seven stage VCO varies from 1.47 to 1.41 GHz with varying power from 1.89 to 4.12 mW. Power consumption and output frequency of proposed VCO circuits have been compared with earlier reported circuits and present approach shows considerable improvements.

  10. Protein phosphatases decrease their activity during capacitation: a new requirement for this event.

    Directory of Open Access Journals (Sweden)

    Janetti R Signorelli

    Full Text Available There are few reports on the role of protein phosphatases during capacitation. Here, we report on the role of PP2B, PP1, and PP2A during human sperm capacitation. Motile sperm were resuspended in non-capacitating medium (NCM, Tyrode's medium, albumin- and bicarbonate-free or in reconstituted medium (RCM, NCM plus 2.6% albumin/25 mM bicarbonate. The presence of the phosphatases was evaluated by western blotting and the subcellular localization by indirect immunofluorescence. The function of these phosphatases was analyzed by incubating the sperm with specific inhibitors: okadaic acid, I2, endothall, and deltamethrin. Different aliquots were incubated in the following media: 1 NCM; 2 NCM plus inhibitors; 3 RCM; and 4 RCM plus inhibitors. The percent capacitated sperm and phosphatase activities were evaluated using the chlortetracycline assay and a phosphatase assay kit, respectively. The results confirm the presence of PP2B and PP1 in human sperm. We also report the presence of PP2A, specifically, the catalytic subunit and the regulatory subunits PR65 and B. PP2B and PP2A were present in the tail, neck, and postacrosomal region, and PP1 was present in the postacrosomal region, neck, middle, and principal piece of human sperm. Treatment with phosphatase inhibitors rapidly (≤1 min increased the percent of sperm depicting the pattern B, reaching a maximum of ∼40% that was maintained throughout incubation; after 3 h, the percent of capacitated sperm was similar to that of the control. The enzymatic activity of the phosphatases decreased during capacitation without changes in their expression. The pattern of phosphorylation on threonine residues showed a sharp increase upon treatment with the inhibitors. In conclusion, human sperm express PP1, PP2B, and PP2A, and the activity of these phosphatases decreases during capacitation. This decline in phosphatase activities and the subsequent increase in threonine phosphorylation may be an important

  11. Multimodality imaging of reporter gene expression using a novel fusion vector in living cells and animals

    Science.gov (United States)

    Gambhir; Sanjiv , Pritha; Ray

    2009-04-28

    Novel double and triple fusion reporter gene constructs harboring distinct imageable reporter genes are provided, as well as applications for the use of such double and triple fusion constructs in living cells and in living animals using distinct imaging technologies.

  12. CAPACITIVE TOMOGRAPHY FOR THE LOCATION OF PLASTIC PIPE

    Energy Technology Data Exchange (ETDEWEB)

    Brian J. Huber

    2002-10-30

    Throughout the utility industry, there is high interest in subsurface imaging of plastic, ceramic, and metallic objects because of the cost, reliability, and safety benefits available in avoiding impacts with the existing infrastructure and in reducing inappropriate excavations. Industry interest in locating plastic pipe has resulted in funding available for the development of technologies that enable this imaging. Gas Technology Institute (GTI) proposes to develop a compact and inexpensive capacitive tomography imaging sensor that takes the form of a flat plate or flexible mat that can be placed on the ground to image objects embedded in the soil. A compact, low-cost sensor that can image objects through soil could be applied to multiple operations and will produce a number of cost savings for the gas industry. In a stand-alone mode, it could be used to survey an area prior to excavation. The technology would improve the accuracy and reliability of any operation that involves excavation by locating or avoiding buried objects. An accurate subsurface image of an area will enable less costly keyhole excavations and other cost-saving techniques. Ground penetrating radar (GPR) has been applied to this area with limited success. Radar requires a high-frequency carrier to be injected into the soil: the higher the frequency, the greater the image resolution. Unfortunately, high-frequency radio waves are more readily absorbed by soil. Also, high-frequency operation raises the cost of the associated electronics. By contrast, the capacitive tomography sensor uses low frequencies with a multiple-element antenna to obtain good resolution. Low-frequency operation lowers the cost of the associated electronics while improving depth of penetration. The objective of this project is to combine several existing techniques in the area of capacitive sensing to quickly produce a demonstrable prototype. The sensor itself will take the form of a flat array of electrodes that can be

  13. Electrical Capacitance Volume Tomography with High-Contrast Dielectrics

    Science.gov (United States)

    Nurge, Mark

    2010-01-01

    The Electrical Capacitance Volume Tomography (ECVT) system has been designed to complement the tools created to sense the presence of water in nonconductive spacecraft materials, by helping to not only find the approximate location of moisture but also its quantity and depth. The ECVT system has been created for use with a new image reconstruction algorithm capable of imaging high-contrast dielectric distributions. Rather than relying solely on mutual capacitance readings as is done in traditional electrical capacitance tomography applications, this method reconstructs high-resolution images using only the self-capacitance measurements. The image reconstruction method assumes that the material under inspection consists of a binary dielectric distribution, with either a high relative dielectric value representing the water or a low dielectric value for the background material. By constraining the unknown dielectric material to one of two values, the inverse math problem that must be solved to generate the image is no longer ill-determined. The image resolution becomes limited only by the accuracy and resolution of the measurement circuitry. Images were reconstructed using this method with both synthetic and real data acquired using an aluminum structure inserted at different positions within the sensing region. The cuboid geometry of the system has two parallel planes of 16 conductors arranged in a 4 4 pattern. The electrode geometry consists of parallel planes of copper conductors, connected through custom-built switch electronics, to a commercially available capacitance to digital converter. The figure shows two 4 4 arrays of electrodes milled from square sections of copper-clad circuit-board material and mounted on two pieces of glass-filled plastic backing, which were cut to approximately square shapes, 10 cm on a side. Each electrode is placed on 2.0-cm centers. The parallel arrays were mounted with the electrode arrays approximately 3 cm apart. The open ends

  14. 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)

  15. Enhanced capacitive properties of commercial activated carbon by re-activation in molten carbonates

    Science.gov (United States)

    Lu, Beihu; Xiao, Zuoan; Zhu, Hua; Xiao, Wei; Wu, Wenlong; Wang, Dihua

    2015-12-01

    Simple, affordable and green methods to improve capacitive properties of commercial activated carbon (AC) are intriguing since ACs possess a predominant role in the commercial supercapacitor market. Herein, we report a green reactivation of commercial ACs by soaking ACs in molten Na2CO3-K2CO3 (equal in mass ratios) at 850 °C combining the merits of both physical and chemical activation strategies. The mechanism of molten carbonate treatment and structure-capacitive activity correlations of the ACs are rationalized. Characterizations show that the molten carbonate treatment increases the electrical conductivity of AC without compromising its porosity and wettability of electrolytes. Electrochemical tests show the treated AC exhibited higher specific capacitance, enhanced high-rate capability and excellent cycle performance, promising its practical application in supercapacitors. The present study confirms that the molten carbonate reactivation is a green and effective method to enhance capacitive properties of ACs.

  16. Hysteretic self-oscillating bandpass current mode control for Class D audio amplifiers driving capacitive transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2013-01-01

    A hysteretic self-oscillating bandpass current mode control (BPCM) scheme for Class D audio amplifiers driving capacitive transducers are presented. The scheme provides excellent stability margins and low distortion over a wide range of operating conditions. Small-signal behavior of the amplifier...... the rules of electrostatics have been known as very interesting alternatives to the traditional inefficient electrodynamic transducers. When driving capacitive transducers from a Class D audio amplifier the high impedance nature of the load represents a key challenge. The BPCM control scheme ensures a flat...... is analysis through transfer function based linear control methodology. Measurements are performed on a single-ended ± 300 V half-bridge amplifier driving a capacitive load of 100 nF. Total Harmonic Distortion plus noise (THD+N) below 0.1 % are reported. Transducers representing a capacitive load and obeying...

  17. Capacitance-modulated transistor detects odorant binding protein chiral interactions

    Science.gov (United States)

    Mulla, Mohammad Yusuf; Tuccori, Elena; Magliulo, Maria; Lattanzi, Gianluca; Palazzo, Gerardo; Persaud, Krishna; Torsi, Luisa

    2015-01-01

    Peripheral events in olfaction involve odorant binding proteins (OBPs) whose role in the recognition of different volatile chemicals is yet unclear. Here we report on the sensitive and quantitative measurement of the weak interactions associated with neutral enantiomers differentially binding to OBPs immobilized through a self-assembled monolayer to the gate of an organic bio-electronic transistor. The transduction is remarkably sensitive as the transistor output current is governed by the small capacitance of the protein layer undergoing minute changes as the ligand-protein complex is formed. Accurate determination of the free-energy balances and of the capacitance changes associated with the binding process allows derivation of the free-energy components as well as of the occurrence of conformational events associated with OBP ligand binding. Capacitance-modulated transistors open a new pathway for the study of ultra-weak molecular interactions in surface-bound protein-ligand complexes through an approach that combines bio-chemical and electronic thermodynamic parameters.

  18. 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, c

  19. MR Imaging in a Child with Survey: a Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seung Woo; Park, Sun Won; Kwon, Young Se; Oh, In Suk; Lim, Myung Kwan; Kim, Won Hong; Suh, Chang Hae [College of Medicine, Inha University, Incheon (Korea, Republic of)

    2007-10-15

    Scurvy is very rare disease in industrialized societies. Nevertheless, it still exists in higher risk groups including economically disadvantaged populations with poor nutrition, such as the elderly and chronic alcoholics. The incidence of scurvy in the pediatric population is very low. This study reports a case of scurvy in a 5-year-old girl with cerebral palsy and developmental delay based on MRI findings. curvy results from a deficiency of ascorbic acid (vitamin C). A marked reduction in the occurrence of scurvy has occurred over the last 100 years due to improved knowledge about the pathophysiology and treatment of scurvy. However, the disease still exists even in industrialized countries. Because scurvy is rare in modern society, reported magnetic resonance imaging (MRI) findings associated with scurvy are very rare. We report a case of scurvy in a 5-year-old girl with associated MRI findings. The diagnosis of scurvy is made by clinical and radiographic findings and may be supported by additional findings such as reduced levels of vitamin C in the serum or Buffy-coat of leukocytes. The MRI findings of scurvy are not well known; however, when the MRI findings include subperiosteal hematoma with periostitis, metaphyseal changes, and heterogeneous bone marrow signal intensity, scurvy should be included in the differential diagnosis. Clinicians and radiologists must be aware of this extremely rare but still present condition, because it is potentially fatal and easily cured with vitamin C supplementation.

  20. Score cards for standardized comparison of myocardial perfusion imaging reports

    DEFF Research Database (Denmark)

    Jensen, Julie D; Hoff, Camilla; Bouchelouche, Kirsten

    Background: When optimizing scan protocols or comparing modalities in myocardial perfusion imaging, it is necessary to compare the current method to the new method This can be achieved by a comparison based on hard numbers such as MBF, summed rest and stress scores, total perfusion deficit etc....... However, what is of importance to the patient is the total evaluation of these scores and the weight and confidence ascribed to each by the reporting physician. We suggest a standardized method summarizing the observations and the confidence of the physician in simple scores. We tested the developed score...... cards in a pilotproject using a training scenario where 3 observers with varying experience (1 month, 5 months and 3 years, respectively) scored static rest/stress Rb-82 PET scans. Method: 10 patients with known ischemic heart disease were included. Using the 17-segment AHA cardiac model, each patient...

  1. Final Technical Report for SISGR: Ultrafast Molecular Scale Chemical Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Hersam, Mark C. [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering; Guest, Jeffrey R. [Argonne National Lab. (ANL), Argonne, IL (United States). Center for Nanoscale Materials; Guisinger, Nathan P. [Argonne National Lab. (ANL), Argonne, IL (United States). Center for Nanoscale Materials; Hla, Saw Wai [Argonne National Lab. (ANL), Argonne, IL (United States). Center for Nanoscale Materials; Schatz, George C. [Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry; Seideman, Tamar [Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry; Van Duyne, Richard P. [Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry

    2017-04-10

    The Northwestern-Argonne SISGR program utilized newly developed instrumentation and techniques including integrated ultra-high vacuum tip-enhanced Raman spectroscopy/scanning tunneling microscopy (UHV-TERS/STM) and surface-enhanced femtosecond stimulated Raman scattering (SE-FSRS) to advance the spatial and temporal resolution of chemical imaging for the study of photoinduced dynamics of molecules on plasmonically active surfaces. An accompanying theory program addressed modeling of charge transfer processes using constrained density functional theory (DFT) in addition to modeling of SE-FSRS, thereby providing a detailed description of the excited state dynamics. This interdisciplinary and highly collaborative research resulted in 62 publications with ~ 48% of them being co-authored by multiple SISGR team members. A summary of the scientific accomplishments from this SISGR program is provided in this final technical report.

  2. Liver Imaging Reporting and Data System: an expert consensus statement

    Directory of Open Access Journals (Sweden)

    Elsayes KM

    2017-02-01

    Full Text Available Khaled M Elsayes,1 Ania Z Kielar,2 Michelle M Agrons,3 Janio Szklaruk,1 An Tang,4 Mustafa R Bashir,5 Donald G Mitchell,6 Richard K Do,7 Kathryn J Fowler,8 Victoria Chernyak,9 Claude B Sirlin10 1Department of Diagnostic Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; 2Department of Diagnostic Radiology, University of Ottawa, Ottawa, ON, Canada; 3Department of Diagnostic Radiology, Baylor College of Medicine, Houston, TX, USA; 4Department of Radiology, Radio-Oncology and Nuclear Medicine, Université de Montréal, Montreal, QC, Canada; 5Department of Diagnostic Radiology, Duke University School of Medicine, Durham, NC, 6Department of Diagnostic Radiology, Thomas Jefferson University, Philadelphia, PA, 7Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, 8Mallinckrodt Institute of Radiology, Washington University in Saint Louis, Saint Louis, MO, 9Department of Radiology Albert Einstein College of Medicine, Bronx, New York, NY, 10Department of Diagnostic Radiology, University of California, San Diego, CA, USA Abstract: The increasing incidence and high morbidity and mortality of hepatocellular carcinoma (HCC have inspired the creation of the Liver Imaging Reporting and Data System (LI-RADS. LI-RADS aims to reduce variability in exam interpretation, improve communication, facilitate clinical therapeutic decisions, reduce omission of pertinent information, and facilitate the monitoring of outcomes. LI-RADS is a dynamic process, which is updated frequently. In this article, we describe the LI-RADS 2014 version (v2014, which marks the second update since the initial version in 2011. Keywords: hepatocellular carcinoma, imaging, reporting, cirrhosis, hyperenhancement washout

  3. Cross-section imaging and p-type doping assessment of ZnO/ZnO:Sb core-shell nanowires by scanning capacitance microscopy and scanning spreading resistance microscopy

    Science.gov (United States)

    Wang, Lin; Sallet, Vincent; Sartel, Corinne; Brémond, Georges

    2016-08-01

    ZnO/ZnO:Sb core-shell structured nanowires (NWs) were grown by the metal organic chemical vapor deposition method where the shell was doped with antimony (Sb) in an attempt to achieve ZnO p-type conduction. To directly investigate the Sb doping effect in ZnO, scanning capacitance microscopy (SCM) and scanning spreading resistance microscopy (SSRM) were performed on the NWs' cross-sections mapping their two dimensional (2D) local electrical properties. Although no direct p-type inversion in ZnO was revealed, a lower net electron concentration was pointed out for the Sb-doped ZnO shell layer with respect to the non-intentionally doped ZnO core, indicating an evident compensating effect as a result of the Sb incorporation, which can be ascribed to the formation of Sb-related acceptors. The results demonstrate SCM/SSRM investigation being a direct and effective approach for characterizing radial semiconductor one-dimensional (1D) structures and, particularly, for the doping study on the ZnO nanomaterial towards its p-type realization.

  4. Cross-section imaging and p-type doping assessment of ZnO/ZnO:Sb core-shell nanowires by scanning capacitance microscopy and scanning spreading resistance microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lin, E-mail: lin.wang@insa-lyon.fr; Brémond, Georges [Institut des Nanotechnologies de Lyon (INL), Université de Lyon, CNRS UMR 5270, INSA Lyon, Bat. Blaise Pascal, 7 Avenue, Jean Capelle, 69621 Villeurbanne (France); Sallet, Vincent; Sartel, Corinne [Groupe d' étude de la Matière Condensée (GEMaC), CNRS - Université de Versailles St Quentin en Yvelines, Université Paris-Saclay, 45 Avenue des Etats-Unis, 78035 Versailles (France)

    2016-08-29

    ZnO/ZnO:Sb core-shell structured nanowires (NWs) were grown by the metal organic chemical vapor deposition method where the shell was doped with antimony (Sb) in an attempt to achieve ZnO p-type conduction. To directly investigate the Sb doping effect in ZnO, scanning capacitance microscopy (SCM) and scanning spreading resistance microscopy (SSRM) were performed on the NWs' cross-sections mapping their two dimensional (2D) local electrical properties. Although no direct p-type inversion in ZnO was revealed, a lower net electron concentration was pointed out for the Sb-doped ZnO shell layer with respect to the non-intentionally doped ZnO core, indicating an evident compensating effect as a result of the Sb incorporation, which can be ascribed to the formation of Sb-related acceptors. The results demonstrate SCM/SSRM investigation being a direct and effective approach for characterizing radial semiconductor one-dimensional (1D) structures and, particularly, for the doping study on the ZnO nanomaterial towards its p-type realization.

  5. Evaluation of electrical capacitance tomography sensor based on the coupling of fluid field and electrostatic field

    Science.gov (United States)

    Ye, Jiamin; Wang, Haigang; Yang, Wuqiang

    2016-07-01

    Electrical capacitance tomography (ECT) is based on capacitance measurements from electrode pairs mounted outside of a pipe or vessel. The structure of ECT sensors is vital to image quality. In this paper, issues with the number of electrodes and the electrode covering ratio for complex liquid-solids flows in a rotating device are investigated based on a new coupling simulation model. The number of electrodes is increased from 4 to 32 while the electrode covering ratio is changed from 0.1 to 0.9. Using the coupling simulation method, real permittivity distributions and the corresponding capacitance data at 0, 0.5, 1, 2, 3, 5, and 8 s with a rotation speed of 96 rotations per minute (rpm) are collected. Linear back projection (LBP) and Landweber iteration algorithms are used for image reconstruction. The quality of reconstructed images is evaluated by correlation coefficient compared with the real permittivity distributions obtained from the coupling simulation. The sensitivity for each sensor is analyzed and compared with the correlation coefficient. The capacitance data with a range of signal-to-noise ratios (SNRs) of 45, 50, 55 and 60 dB are generated to evaluate the effect of data noise on the performance of ECT sensors. Furthermore, the SNRs of experimental data are analyzed for a stationary pipe with permittivity distribution. Based on the coupling simulation, 16-electrode ECT sensors are recommended to achieve good image quality.

  6. Capacitive Substrate Coupling of Row–Column-Addressed 2-D CMUT Arrays

    DEFF Research Database (Denmark)

    Engholm, Mathias; Bouzari, Hamed; Jensen, Jørgen Arendt;

    2016-01-01

    of the semiconductor substrate can be sustained for at least 10 minutes making it applicable for row–column-addressed CMUT arrays for ultrasonic imaging. Theoretically the reduced parasitic capacitance indicates that the receive sensitivity of the bottom elements can be increased by a factor of 2:1....

  7. Microphonics in biopotential measurements with capacitive electrodes.

    Science.gov (United States)

    Luna-Lozano, Pablo S; Pallas-Areny, Ramon

    2010-01-01

    Biopotential measurements with capacitive electrodes do not need any direct contact between electrode and skin, which saves the time devoted to expose and prepare the contact area when measuring with conductive electrodes. However, mechanical vibrations resulting from physiological functions such as respiration and cardiac contraction can change the capacitance of the electrode and affect the recordings. This transformation of mechanical vibrations into undesired electric signals is termed microphonics. We have evaluated microphonics in capacitive ECG recordings obtained from a dressed subject seated on a common chair with electrodes placed on the front side of the backrest of the chair. Depending on the softness of the backrest, the recordings may be clearly affected by the displacement of the thorax back wall due to the respiration and to the heart's mechanical activity.

  8. 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.

  9. Role of the oviduct in sperm capacitation.

    Science.gov (United States)

    Rodriguez-Martinez, H

    2007-09-01

    Following insemination of spermatozoa pre-ovulation, the mammalian oviduct ensures, by the formation of a functional sperm reservoir (SR), that suitable (low) numbers of viable and potentially fertile spermatozoa are available for fertilization at the ampullary isthmic junction (AIJ). As ovulation approaches, a proportion of the SR-stored spermatozoa is continuously distributed towards the AIJ and individually activated leading to step-wise capacitation and the attainment of hyperactivated motility. This paper reviews in vivo changes in the intra-luminal milieu of the oviduct of pigs and cows, in particular the SR and the AIJ which relate to the modulation of sperm capacitation around spontaneous ovulation. In vivo, most viable spermatozoa in the pre-ovulatory SR are uncapacitated. Capacitation rates significantly increase after ovulation, apparently not massively but concurrent with the individual, continuous sperm dislocation from the SR. Bicarbonate, whose levels differ between the SR and the AIJ, appears as the common primary effector of the membrane destabilizing changes that encompasses the first stages of capacitation. Sperm activation can be delayed or even reversed by co-incubation with membrane proteins of the tubal lining, isthmic fluid or specific tubal glycosaminoglycans, such as hyaluronan. Although the pattern of response to in vitro induction of sperm activation - capacitation in particular - is similar for all spermatozoa, the capacity and speed of the response is very individual. Such diversity in responsiveness among spermatozoa insures full sperm viability before ovulation and the presence of spermatozoa at different stages of capacitation at the AIJ, thus maximizing the chances of normal fertilization.

  10. National Land Imaging Requirements (NLIR) Pilot Project summary report: summary of moderate resolution imaging user requirements

    Science.gov (United States)

    Vadnais, Carolyn; Stensaas, Gregory

    2014-01-01

    Under the National Land Imaging Requirements (NLIR) Project, the U.S. Geological Survey (USGS) is developing a functional capability to obtain, characterize, manage, maintain and prioritize all Earth observing (EO) land remote sensing user requirements. The goal is a better understanding of community needs that can be supported with land remote sensing resources, and a means to match needs with appropriate solutions in an effective and efficient way. The NLIR Project is composed of two components. The first component is focused on the development of the Earth Observation Requirements Evaluation System (EORES) to capture, store and analyze user requirements, whereas, the second component is the mechanism and processes to elicit and document the user requirements that will populate the EORES. To develop the second component, the requirements elicitation methodology was exercised and refined through a pilot project conducted from June to September 2013. The pilot project focused specifically on applications and user requirements for moderate resolution imagery (5–120 meter resolution) as the test case for requirements development. The purpose of this summary report is to provide a high-level overview of the requirements elicitation process that was exercised through the pilot project and an early analysis of the moderate resolution imaging user requirements acquired to date to support ongoing USGS sustainable land imaging study needs. The pilot project engaged a limited set of Federal Government users from the operational and research communities and therefore the information captured represents only a subset of all land imaging user requirements. However, based on a comparison of results, trends, and analysis, the pilot captured a strong baseline of typical applications areas and user needs for moderate resolution imagery. Because these results are preliminary and represent only a sample of users and application areas, the information from this report should only

  11. Capacitance sensor for automatic soil retreat measurements

    Institute of Scientific and Technical Information of China (English)

    GU Jun; YANG Juan; YIN Wu-liang; WANG Chao; WANG Hua-xiang; LIU Ze; CHENG Su-sen

    2008-01-01

    To continuously monitor the soil retreat due to erosion in field, provide valuable information about the erosion processes and overcome the disadvantages of inefficiency, high time-consumption and labor-intensity of existing methods, this paper describes a novel capacitance sensor for measuring the soil retreat. A capaci-tance sensor based probe is proposed, which can measure the depth of the soil around it automatically and the data can be recorded by a data logger. Experimental results in the lab verify its usefulness.

  12. Experimental study of negative capacitance in LEDs

    Institute of Scientific and Technical Information of China (English)

    FENG Lie-feng; WANG Jun; ZHU Chuan-yun; CONG Hong-xia; CHEN Yong; WANG Cun-da

    2005-01-01

    The experimental study on negative capacitance(NC) of various light-emitting diodes(LEDs) is presented.Experimental result shows that all LEDs display the NC phenomenon.The voltage modulated electroluminescence(VMEL) experiment confirms that the reason of negative capacitance is the strong recombination of the injected carriers in the active region of luminescence.The measures also verify that the dependence of NC on voltage and frequency in different LEDs is similar: NC phenomenon is more obvious with higher voltage or lower frequency.

  13. Quantum capacitance of the armchair-edge graphene nanoribbon

    Indian Academy of Sciences (India)

    Ling-Feng Mao

    2013-08-01

    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 oscillations are found and these capacitance oscillations originate from the lateral quantum confinement in graphene nanoribbon. Detailed studies of the capacitance oscillations demonstrate that the local channel electrostatic potential at the capacitance peak, the height and the number of the capacitance peak strongly depend on the width, especially a few nanometres, of the armchair-edge graphene nanoribbon. It implies that the capacitance oscillations observed in the experiments can be utilized to measure the width of graphene nanoribbon. The results also show that the capacitance oscillations are not seen when the width is larger than 30 nm.

  14. Investigation on a Novel Capacitive Electrode for Geophysical Surveys

    Directory of Open Access Journals (Sweden)

    Zhiyu Wang

    2016-01-01

    Full Text Available Nonpolarizable electrodes are applied widely in the electric field measurement for geophysical surveys. However, there are two major problems: (1 systematic errors caused by poor electrical contact in the high resistive terrains and (2 environmental damage associated with using nonpolarizable electrodes. A new alternative structure of capacitive electrode, which is capable of sensing surface potential through weak capacitive coupling, is presented to solve the above problems. A technique is introduced to neutralize distributed capacitance and input capacitance of the detection circuit. With the capacitance neutralization technique, the transmission coefficient of capacitive electrode remains stable when environmental conditions change. The simulation and field test results indicate that the new capacitive electrode has an operating bandwidth range from 0.1 Hz to 1 kHz. The capacitive electrodes have a good prospect of the applications in geophysical prospecting, especially in resistive terrains.

  15. 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...

  16. Constant capacitance in nanopores of carbon monoliths.

    Science.gov (United States)

    García-Gómez, Alejandra; Moreno-Fernández, Gelines; Lobato, Belén; Centeno, Teresa A

    2015-06-28

    The results obtained for binder-free electrodes made of carbon monoliths with narrow micropore size distributions confirm that the specific capacitance in the electrolyte (C2H5)4NBF4/acetonitrile does not depend significantly on the micropore size and support the foregoing constant result of 0.094 ± 0.011 F m(-2).

  17. 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

  18. Final Report - DOE Center for Laser Imaging and Cancer Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Alfano, Robert R.; Koutcher, Jason A.

    2002-10-31

    This Final Report summarizes the significant progress made by the researchers, students and staff of the Center for Laser Imaging and Cancer Diagnostics (CLICD) from January 1998 through May 2002. During this period, the Center supported several projects. Most projects were proposed initially, some were added subsequently as their relevance and importance to the DOE mission became evident. DOE support has been leveraged to obtain continuing funding for some projects. Leveraged funds come from various sources, including NIH, Army, NSF and the Air Force. The goal of the Center was to develop laser-based instruments for use in the detection and diagnosis of major diseases, with an emphasis on detection and diagnosis of various cancers. Each of the supported projects is a collaborative effort between physicists and laser scientists and the City College of New York and noted physicians, surgeons, pathologists, and biologists located at medical centers in the Metropolitan area. The participating institutions were: City College of New York Institute for Ultrafast Lasers and Spectroscopy, Hackensack University Medical Center, Lawrence Livermore National Laboratory, Memorial Sloan Kettering Cancer Center, and New York Eye and Ear Institute. Each of the projects funded by the Center is grouped into one of four research categories: a) Disease Detection, b) Non-Disease Applications, c) New Diagnostic Tools, and, d) Education, Training, Outreach and Dissemination. The progress achieved by the multidisciplinary teams was reported in 51 publications and 32 presentations at major national conferences. Also, one U.S. patent was obtained and six U.S. patent applications have been filed for innovations resulting from the projects sponsored by the Center.

  19. Winding Capacitance Dividing Method for Powerformer

    Institute of Scientific and Technical Information of China (English)

    TIAN Qing; LIN Xiang-ning; LI Jian-jian; TAO Yong-hong

    2008-01-01

    It presents a method which can equivalently arrange the capacitance distribution along with the winding ofthe generator on the terminal and neutral respectively in a reasonable partition, particularly for a type of high-voltagegraded insulated cable wound generator, Powerformer. The winding of the Powerformer adopts graded insulation,which leads to the various cable thicknesses in different portion of the winding, and thus, the uneven capacitancedistribution. The large capacitive currents and large transient outrush currents resulting from the cable consisting ofthe stator winding of Powerformer may cause problems to the generator differential protection. Most of literatures a-vailable in the field of compensated differential protection focus on the charging current compensation for long trans-mission line, instead of for generator. The authors give a method which can be used to compensate the capacitivecurrent wholly to improve the reliability of the differential protection of Powerformer. It is proved that the distribu-ted capacitance can be equivalent as the lump circuit with a capacitance partition coefficient p, and p is proved as aconstant no matter whether the generator experiences the normal operation, external phase(s) fault or internal phase(s) fault. The formula of the partition coefficient is provided and the corresponding equivalent circuit of the Power-former cable to calculate capacitance currents is given. An analysis programming resolving the minimum value of thecoefficient p is written in MATLAB 7. 0/m according to this formula, using the function fmincon() which can workin any type of constraint condition. The program always gets the same global minimum points under the different in-itial values condition which proves our point by mathematical test. With this new approach to winding capacitancedividing method, the protection scheme used for Powerformer can be validated and improved accordingly.

  20. Direct in situ measurement of specific capacitance, monolayer tension, and bilayer tension in a droplet interface bilayer.

    Science.gov (United States)

    Taylor, Graham J; Venkatesan, Guru A; Collier, C Patrick; Sarles, Stephen A

    2015-10-14

    Thickness and tension are important physical parameters of model cell membranes. However, traditional methods to measure these quantities require multiple experiments using separate equipment. This work introduces a new multi-step procedure for directly accessing in situ multiple physical properties of droplet interface bilayers (DIB), including specific capacitance (related to thickness), lipid monolayer tension in the Plateau-Gibbs border, and bilayer tension. The procedure employs a combination of mechanical manipulation of bilayer area followed by electrowetting of the capacitive interface to examine the sensitivities of bilayer capacitance to area and contact angle to voltage, respectively. These data allow for determining the specific capacitance of the membrane and surface tension of the lipid monolayer, which are then used to compute bilayer thickness and tension, respectively. The use of DIBs affords accurate optical imaging of the connected droplets in addition to electrical measurements of bilayer capacitance, and it allows for reversibly varying bilayer area. After validating the accuracy of the technique with diphytanoyl phosphatidylcholine (DPhPC) DIBs in hexadecane, the method is applied herein to quantify separately the effects on membrane thickness and tension caused by varying the solvent in which the DIB is formed and introducing cholesterol into the bilayer. Because the technique relies only on capacitance measurements and optical images to determine both thickness and tension, this approach is specifically well-suited for studying the effects of peptides, biomolecules, natural and synthetic nanoparticles, and other species that accumulate within membranes without altering bilayer conductance.

  1. Capacitive Bioanodes Enable Renewable Energy Storage in Microbial Fuel Cells

    NARCIS (Netherlands)

    Deeke, A.; Sleutels, T.H.J.A.; Hamelers, H.V.M.; Buisman, C.J.N.

    2012-01-01

    We developed an integrated system for storage of renewable electricity in a microbial fuel cell (MFC). The system contained a capacitive electrode that was inserted into the anodic compartment of an MFC to form a capacitive bioanode. This capacitive bioanode was compared with a noncapacitive

  2. Electropolymerized Star-Shaped Benzotrithiophenes Yield π-Conjugated Hierarchical Networks with High Areal Capacitance

    KAUST Repository

    Ringk, Andreas

    2016-03-30

    High-surface-area π-conjugated polymeric networks have the potential to lend outstanding capacitance to supercapacitors because of the pronounced faradaic processes that take place across the dense intimate interface between active material and electrolytes. In this report, we describe how benzo[1,2-b:3,4-b’:5,6-b’’]trithiophene (BTT) and tris-EDOT-benzo[1,2-b:3,4-b’:5,6-b’’]trithiophene (TEBTT) can serve as 2D (trivalent) building blocks in the development of electropolymerized hierarchical π-conjugated frameworks with particularly high areal capacitance. In comparing electropolymerized networks of BTT, TEBTT, and their copolymers with EDOT, we show that P(TEBTT/EDOT)-based frameworks can achieve higher areal capacitance (e.g., as high as 443.8 mF cm-2 at 1 mA cm-2) than those achieved by their respective homopolymers (PTEBTT and PEDOT) in the same experimental conditions of electrodeposition (PTEBTT: 271.1 mF cm-2 (at 1 mA cm-2) and PEDOT: 12.1 mF cm-2 (at 1 mA cm-2)). For example, P(TEBTT/EDOT)-based frameworks synthesized in a 1:1 monomer-to-comonomer ratio show a ca. 35x capacitance improvement over PEDOT. The high areal capacitance measured for P(TEBTT/EDOT) copolymers can be explained by the open, highly porous hierarchical morphologies formed during the electropolymerization step. With >70% capacitance retention over 1,000 cycles (up to 89% achieved), both PTEBTT- and P(TEBTT/EDOT)-based frameworks are resilient to repeated electrochemical cycling and can be considered promising systems for high life cycle capacitive electrode applications.

  3. Tensor-based dynamic reconstruction method for electrical capacitance tomography

    Science.gov (United States)

    Lei, J.; Mu, H. P.; Liu, Q. B.; Li, Z. H.; Liu, S.; Wang, X. Y.

    2017-03-01

    Electrical capacitance tomography (ECT) is an attractive visualization measurement method, in which the acquisition of high-quality images is beneficial for the understanding of the underlying physical or chemical mechanisms of the dynamic behaviors of the measurement objects. In real-world measurement environments, imaging objects are often in a dynamic process, and the exploitation of the spatial-temporal correlations related to the dynamic nature will contribute to improving the imaging quality. Different from existing imaging methods that are often used in ECT measurements, in this paper a dynamic image sequence is stacked into a third-order tensor that consists of a low rank tensor and a sparse tensor within the framework of the multiple measurement vectors model and the multi-way data analysis method. The low rank tensor models the similar spatial distribution information among frames, which is slowly changing over time, and the sparse tensor captures the perturbations or differences introduced in each frame, which is rapidly changing over time. With the assistance of the Tikhonov regularization theory and the tensor-based multi-way data analysis method, a new cost function, with the considerations of the multi-frames measurement data, the dynamic evolution information of a time-varying imaging object and the characteristics of the low rank tensor and the sparse tensor, is proposed to convert the imaging task in the ECT measurement into a reconstruction problem of a third-order image tensor. An effective algorithm is developed to search for the optimal solution of the proposed cost function, and the images are reconstructed via a batching pattern. The feasibility and effectiveness of the developed reconstruction method are numerically validated.

  4. Phosphorimager and PD densitometer imaging system network. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    This document discusses the research projects undertaken as a result of the availability of the PhosphorImager and PD Densitometer Imaging System Network, at the University of Georgia`s Complex Carbohydrate Research Center. The benefit gained from the equipment is described for each project.

  5. Current source enhancements in Electrical Impedance Spectroscopy (EIS) to cancel unwanted capacitive effects

    Science.gov (United States)

    Zarafshani, Ali; Bach, Thomas; Chatwin, Chris; Xiang, Liangzhong; Zheng, Bin

    2017-03-01

    Electrical Impedance Spectroscopy (EIS) has emerged as a non-invasive imaging modality to detect and quantify functional or electrical properties related to the suspicious tumors in cancer screening, diagnosis and prognosis assessment. A constraint on EIS systems is that the current excitation system suffers from the effects of stray capacitance having a major impact on the hardware subsystem as the EIS is an ill-posed inverse problem which depends on the noise level in EIS measured data and regularization parameter in the reconstruction algorithm. There is high complexity in the design of stable current sources, with stray capacitance reducing the output impedance and bandwidth of the system. To confront this, we have designed an EIS current source which eliminates the effect of stray capacitance and other impacts of the capacitance via a variable inductance. In this paper, we present a combination of operational CCII based on a generalized impedance converter (OCCII-GIC) with a current source. The aim of this study is to use the EIS system as a biomedical imaging technique, which is effective in the early detection of breast cancer. This article begins with the theoretical description of the EIS structure, current source topologies and proposes a current conveyor in application of a Gyrator to eliminate the current source limitations and its development followed by simulation and experimental results. We demonstrated that the new design could achieve a high output impedance over a 3MHz frequency bandwidth when compared to other types of GIC circuits combined with an improved Howland topology.

  6. Holey graphene hydrogel with in-plane pores for high-performance capacitive desalination

    Institute of Scientific and Technical Information of China (English)

    Weiqing Kong; Xidong Duan; Yongjie Ge; Hongtao Liu; Jiawen Hu; Xiangfeng Duan

    2016-01-01

    Capacitive deionization is an attractive approach to water desalination and treatment.To achieve efficient capacitative desalination,rationally designed electrodes with high specific capacitances,conductivities,and stabilities are necessary.Here we report the construction of a three-dimensional (3D) holey graphene hydrogel (HGH).This material contains abundant in-plane pores,offering efficient ion transport pathways.Furthermore,it forms a highly interconnected network of graphene sheets,providing efficient electron transport pathways,and its 3D hierarchical porous structure can provide a large specific surface area for the adsorption and storage of ions.Consequently,HGH serves as a binder-free electrode material with excellent electrical conductivity.Cyclic voltammetry (CV) measurements indicate that the optimized HGH can achieve specific capacitances of 358.4 F.g-1 in 6 M KOH solution and 148 F.g-1 in 0.5 M NaC1 solution.Because of these high capacitances,HGH has a desalination capacity as high as 26.8 mg.g-1 (applied potential:1.2 V;initial NaCl concentration:~5,000 mg.L-1).

  7. CAPACITIVE TOMOGRAPHY FOR THE LOCATION OF PLASTIC PIPE

    Energy Technology Data Exchange (ETDEWEB)

    Brian J. Huber

    2003-07-29

    Throughout the utility industry, there is high interest in subsurface imaging of plastic, ceramic, and metallic objects because of the cost, reliability, and safety benefits available in avoiding impacts with the existing infrastructure and in reducing inappropriate excavations. Industry interest in locating plastic pipe has resulted in funding available for the development of technologies that enable this imaging. Gas Technology Institute (GTI) proposes to develop a compact and inexpensive capacitive tomography imaging sensor that takes the form of a flat plate or flexible mat that can be placed on the ground to image objects embedded in the soil. A compact, low-cost sensor that can image objects through soil could be applied to multiple operations and will produce a number of cost savings for the gas industry. In a stand-alone mode, it could be used to survey an area prior to excavation. The technology would improve the accuracy and reliability of any operation that involves excavation by locating or avoiding buried objects. An accurate subsurface image of an area will enable less costly keyhole excavations and other cost-saving techniques. Ground penetrating radar (GPR) has been applied to this area with limited success. Radar requires a high-frequency carrier to be injected into the soil: the higher the frequency, the greater the image resolution. Unfortunately, high-frequency radio waves are more readily absorbed by soil. Also, high-frequency operation raises the cost of the associated electronics. By contrast, the capacitive tomography sensor uses low frequencies with a multiple-element antenna to obtain good resolution. Low-frequency operation lowers the cost of the associated electronics while improving depth of penetration. The objective of this project is to combine several existing techniques in the area of capacitive sensing to quickly produce a demonstrable prototype. The sensor itself will take the form of a flat array of electrodes that can be

  8. Porous Alumina Based Capacitive MEMS RH Sensor

    CERN Document Server

    Juhasz, L; Timar-Horvath, Veronika; Desmulliez, Marc; Dhariwal, Resh

    2008-01-01

    The aim of a joint research and development project at the BME and HWU is to produce a cheap, reliable, low-power and CMOS-MEMS process compatible capacitive type relative humidity (RH) sensor that can be incorporated into a state-of-the-art, wireless sensor network. In this paper we discuss the preparation of our new capacitive structure based on post-CMOS MEMS processes and the methods which were used to characterize the thin film porous alumina sensing layer. The average sensitivity is approx. 15 pF/RH% which is more than a magnitude higher than the values found in the literature. The sensor is equipped with integrated resistive heating, which can be used for maintenance to reduce drift, or for keeping the sensing layer at elevated temperature, as an alternative method for temperature-dependence cancellation.

  9. CMOS Integrated Capacitive DC-DC Converters

    CERN Document Server

    Van Breussegem, Tom

    2013-01-01

    This book provides a detailed analysis of all aspects of capacitive DC-DC converter design: topology selection, control loop design and noise mitigation. Readers will benefit from the authors’ systematic overview that starts from the ground up, in-depth circuit analysis and a thorough review of recently proposed techniques and design methodologies.  Not only design techniques are discussed, but also implementation in CMOS is shown, by pinpointing the technological opportunities of CMOS and demonstrating the implementation based on four state-of-the-art prototypes.  Provides a detailed analysis of all aspects of capacitive DC-DC converter design;  Analyzes the potential of this type of DC-DC converter and introduces a number of techniques to unleash their full potential; Combines system theory with practical implementation techniques; Includes unique analysis of CMOS technology for this application; Provides in-depth analysis of four fabricated prototypes.

  10. Automatic Power Factor Correction Using Capacitive Bank

    Directory of Open Access Journals (Sweden)

    Mr.Anant Kumar Tiwari,

    2014-02-01

    Full Text Available 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 to ensure the entire power system always preserving unity power factor. The software and hardware required to implement the suggested automatic power factor correction scheme are explained and its operation is described. APFC thus helps us to decrease the time taken to correct the power factor which helps to increase the efficiency.

  11. 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...... found in many optimal solutions to CVRP instances. An optimal solution to the PCVRP may therefore be useful in itself as a heuristic solution to the CVRP. Further, an attempt can be made to find an even better CVRP solution by solving a TSP, possibly leading to a non-pyramidal route, for each...... of the routes in the PCVRP solution. This paper develops an exact branch-and-cut-and-price (BCP) algorithm for the PCVRP. At the pricing stage, elementary routes can be computed in pseudo-polynomial time in the PCVRP, unlike in the CVRP. We have therefore implemented pricing algorithms that generate only...

  12. 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....

  13. A Versatile Prototyping System for Capacitive Sensing

    Directory of Open Access Journals (Sweden)

    Daniel HRACH

    2008-04-01

    Full Text Available This paper presents a multi-purpose and easy to handle rapid prototyping platform that has been designed for capacitive measurement systems. The core of the prototype platform is a Digital Signal Processor board that allows for the entire data acquisition, data (pre- processing and storage, and communication with any host computer. The platform is running on uCLinux operating system and features the possibility of a fast design and evaluation of capacitive sensor developments. To show the practical benefit of the prototyping platform, three exemplary applications are presented. For all applications, the platform is just plugged to the electrode structure of the sensor front-end without the need for analogue signal pre-conditioning.

  14. In vivo SPECT reporter gene imaging of regulatory T cells.

    Directory of Open Access Journals (Sweden)

    Ehsan Sharif-Paghaleh

    Full Text Available Regulatory T cells (Tregs were identified several years ago and are key in controlling autoimmune diseases and limiting immune responses to foreign antigens, including alloantigens. In vivo imaging techniques including intravital microscopy as well as whole body imaging using bioluminescence probes have contributed to the understanding of in vivo Treg function, their mechanisms of action and target cells. Imaging of the human sodium/iodide symporter via Single Photon Emission Computed Tomography (SPECT has been used to image various cell types in vivo. It has several advantages over the aforementioned imaging techniques including high sensitivity, it allows non-invasive whole body studies of viable cell migration and localisation of cells over time and lastly it may offer the possibility to be translated to the clinic. This study addresses whether SPECT/CT imaging can be used to visualise the migratory pattern of Tregs in vivo. Treg lines derived from CD4(+CD25(+FoxP3(+ cells were retrovirally transduced with a construct encoding for the human Sodium Iodide Symporter (NIS and the fluorescent protein mCherry and stimulated with autologous DCs. NIS expressing self-specific Tregs were specifically radiolabelled in vitro with Technetium-99m pertechnetate ((99mTcO(4(- and exposure of these cells to radioactivity did not affect cell viability, phenotype or function. In addition adoptively transferred Treg-NIS cells were imaged in vivo in C57BL/6 (BL/6 mice by SPECT/CT using (99mTcO(4(-. After 24 hours NIS expressing Tregs were observed in the spleen and their localisation was further confirmed by organ biodistribution studies and flow cytometry analysis. The data presented here suggests that SPECT/CT imaging can be utilised in preclinical imaging studies of adoptively transferred Tregs without affecting Treg function and viability thereby allowing longitudinal studies within disease models.

  15. Quality factor enhancement of Nano electromechanical systems by capacitive driving beyond the resonance

    CERN Document Server

    Barois, T; Poncharal, P; Vincent, Philippe; Ayari, A

    2016-01-01

    Nano electromechanical systems are considered as ultra sensitive devices for mass and force detection. Capacitive actuation is widely used in these devices but is known to degrade the quality factor of the resonator due to DC electrostatic damping. We report the enhancement of the quality factor of SiC vibrating nanowires detected nano optomechanically and electrically by applying an AC capacitive driving at a frequency above both the resonance frequency and the electrical cutoff frequency. Self-oscillations are demonstrated for optimal conditions. We developed an analytical model of the phenomenon and showed that it can lead to an improvement of the force sensitivity. * anthony.ayari@univ-lyon1.fr 1

  16. A nafion coated capacitive humidity sensor on a flexible PET substrate

    KAUST Repository

    Sapsanis, Christos

    2017-03-07

    This paper reports a simple and low-cost technique for fabricating low-power capacitive humidity sensors without the use of a cleanroom environment. A maskless laser engraving system was utilized to fabricate two different gold electrode structures, interdigitated electrodes and Hilbert\\'s fifth-order fractal. The capacitive structures were implemented on a flexible PET substrate. The usage of Nafion, a well-known polymer for its hydrophilic properties as a sensing film, was attempted on the PET and outperformed the current efforts in flexible substrates. Its humidity sensing properties were evaluated in an automated gas setup with a relative humidity (RH %) ranging from 15% to 95 %.

  17. THERMAL DRIFT CHARACTERISTICS OF CAPACITIVE PRESSURE SENSORS

    OpenAIRE

    2016-01-01

    The capacitive pressure sensors based on silicon are characterized by their very high sensitivities and their low power consumption. Nevertheless, their thermal behavior remains more or less unpredictable because they can indicate very high thermal coefficients. The study of the thermal behavior of these sensors is essential to define the parameters that cause the output characteristics drift. In this study, we modeled the thermal behavior of this sensors, using Finite Element Analysis (FE...

  18. Negative capacitance switching via VO2 band gap engineering driven by electric field

    Science.gov (United States)

    He, Xinfeng; Xu, Jing; Xu, Xiaofeng; Gu, Congcong; Chen, Fei; Wu, Binhe; Wang, Chunrui; Xing, Huaizhong; Chen, Xiaoshuang; Chu, Junhao

    2015-03-01

    We report the negative capacitance behavior of an energy band gap modulation quantum well with a sandwich VO2 layer structure. The phase transition is probed by measuring its capacitance. With the help of theoretical calculations, it shows that the negative capacitance changes of the quantum well device come from VO2 band gap by continuously tuning the temperature or voltage. Experiments reveal that as the current remains small enough, joule heating can be ignored, and the insulator-metal transition of VO2 can be induced by the electric field. Our results open up possibilities for functional devices with phase transitions induced by external electric fields other than the heating or electricity-heat transition.

  19. Application of a novel electrosynthesized polydopamine-imprinted film to the capacitive sensing of nicotine.

    Science.gov (United States)

    Liu, Kai; Wei, Wan-Zhi; Zeng, Jin-Xiang; Liu, Xiao-Ying; Gao, Yan-Ping

    2006-06-01

    The application of novel electrosynthesized polydopamine (PDA)-imprinted film as a recognition element for the capacitive sensing of nicotine is reported. The PDA-imprinted film was electropolymerized directly on the gold electrode surface in the presence of nicotine without an additional self-assembled thiol sublayer. The compact PDA film has various functional groups that aid the imprinting procedure. Furthermore, the film shows good capacitive response since it is insulating in nature and ultrathin. The sensor's linear response range for nicotine was between 1-25 micromol L(-1), with a detection limit of 0.5 micromol L(-1). The proposed molecularly imprinted polymer capacitive (MIPC) sensor exhibited good selectivity for nicotine. The reproducibility and repeatability of the MIPC sensor were all found to be satisfactory. The results from sample analysis confirmed the applicability of the MIPC sensor to quantitative analysis.

  20. Attractive forces in microporous carbon electrodes for capacitive deionization

    CERN Document Server

    Biesheuvel, P M; Levi, M; Bazant, M Z

    2013-01-01

    The recently developed modified Donnan (mD) model provides a simple and useful description of the electrical double layer in microporous carbon electrodes, suitable for incorporation in porous electrode theory. By postulating an attractive excess chemical potential for each ion in the micropores that is inversely proportional to the total ion concentration, we show that experimental data for capacitive deionization (CDI) can be accurately predicted over a wide range of applied voltages and salt concentrations. Since the ion spacing and Bjerrum length are each comparable to the micropore size (few nm), we postulate that the attraction results from fluctuating bare Coulomb interactions between individual ions and the metallic pore surfaces (image forces) that are not captured by meanfield theories, such as the Poisson-Boltzmann-Stern model or its mathematical limit for overlapping double layers, the Donnan model. Using reasonable estimates of the micropore permittivity and mean size (and no other fitting parame...

  1. Evaluation of EHD films by electrical capacitance

    Science.gov (United States)

    Jablonka, Karolina; Glovnea, Romeo; Bongaerts, Jeroen

    2012-09-01

    The elastohydrodynamic (EHD) lubrication regime occurs in many machine elements where a combination of hydrodynamic effect, elastic deformation of the loaded surfaces and increase in the viscosity of the lubricant with pressure ensures the formation of a very thin, but continuous film of lubricant separating the contacting surfaces. Electrical methods to determine this film's thickness have preceded optical methods, which are widely used today. Although they generally give more qualitative thickness information, electrical methods have the main advantage that they can be applied to metallic contacts in machines, which makes them useful tools in the study of elastohydrodynamically lubricated contacts. This paper is part of a larger study on the application of electrical capacitance for the evaluation of film formation in EHD contacts. The main focus is on the quantitative measurements of film thickness using electrical capacitance. A new approach allowing the lubricant film thickness to be extracted from the measured capacitance is developed using a chromium-coated glass disc and subsequently applied to a steel-on-steel contact. The results show good agreement with optical measurements and theoretical models over a range of film thickness.

  2. Effect of Astaxanthin on Human Sperm Capacitation

    Directory of Open Access Journals (Sweden)

    Luciana Bordin

    2013-06-01

    Full Text Available In order to be able to fertilize oocytes, human sperm must undergo a series of morphological and structural alterations, known as capacitation. It has been shown that the production of endogenous sperm reactive oxygen species (ROS plays a key role in causing cells to undergo a massive acrosome reaction (AR. Astaxanthin (Asta, a photo-protective red pigment belonging to the carotenoid family, is recognized as having anti-oxidant, anti-cancer, anti-diabetic and anti-inflammatory properties and is present in many dietary supplements. This study evaluates the effect of Asta in a capacitating buffer which induces low ROS production and low percentages of acrosome-reacted cells (ARC. Sperm cells were incubated in the presence or absence of increasing concentrations of Asta or diamide (Diam and analyzed for their ROS production, Tyr-phosphorylation (Tyr-P pattern and percentages of ARC and non-viable cells (NVC. Results show that Asta ameliorated both sperm head Tyr-P and ARC values without affecting the ROS generation curve, whereas Diam succeeded in enhancing the Tyr-P level but only of the flagellum without increasing ARC values. It is suggested that Asta can be inserted in the membrane and therefore create capacitation-like membrane alteration which allow Tyr-P of the head. Once this has occurred, AR can take place and involves a higher numbers of cells.

  3. A new desalination technique using capacitive deionization

    Science.gov (United States)

    Rostamy, Mohammad Sajjad; Khashechi, Morteza; Pipelzadeh, Ehsan; desalination Team

    2016-11-01

    Capacitive deionization (CDI) is an emerging energy efficient, low pressure and low capital intensive desalination process where ions are separated by a pure electrostatic force imposed by a small bias potential as low as 1 V That funded by an external Renewable (Solar) power supply to materials with high specific surface area. The main objective of this configuration is to separate the cation and anions on oppositely charged electrodes. Various electrode materials have been developed in the past, which have suffered from instability and lack of performance. Preliminary experimental results using carbon black, graphite powder, graphene ∖graphite ∖PTFE (Active ∖Conductive ∖binder), show that the graphene reduced via urea method is a suitable method to develop CDI electrode materials with capacitance as high as 52.2 mg/g for free standing graphene electrode. The focus of these studies has been mainly on developing electrodes with high specific surface area, high capacitance, excellent electronic conductivity and fast charge discharge cycles for desalination. Although some progress has been made, production of efficient and stable carbon based electrode materials for large scale desalination has not been fully realized.

  4. Capacitive Structures for Gas and Biological Sensing

    KAUST Repository

    Sapsanis, Christos

    2015-04-01

    The semiconductor industry was benefited by the advances in technology in the last decades. This fact has an impact on the sensors field, where the simple transducer was evolved into smart miniaturized multi-functional microsystems. However, commercially available gas and biological sensors are mostly bulky, expensive, and power-hungry, which act as obstacles to mass use. The aim of this work is gas and biological sensing using capacitive structures. Capacitive sensors were selected due to its design simplicity, low fabrication cost, and no DC power consumption. In the first part, the dominant structure among interdigitated electrodes (IDEs), fractal curves (Peano and Hilbert) and Archimedean spiral was investigated from capacitance density perspective. The investigation consists of geometrical formula calculations, COMSOL Multiphysics simulations and cleanroom fabrication of the capacitors on a silicon substrate. Moreover, low-cost fabrication on flexible plastic PET substrate was conducted outside cleanroom with rapid prototyping using a maskless laser etching. The second part contains the humidity, Volatile Organic compounds (VOCs) and Ammonia sensing of polymers, Polyimide and Nafion, and metal-organic framework (MOF), Cu(bdc)2.xH2O using IDEs and tested in an automated gas setup for experiment control and data extraction. The last part includes the biological sensing of C - reactive protein (CRP) quantification, which is considered as a biomarker of being prone to cardiac diseases and Bovine serum albumin (BSA) protein quantification, which is used as a reference for quantifying unknown proteins.

  5. MR imaging of dural sinus thrombosis: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Si Kyung; Han, Chun Hwan; Lee, Moon Ok; Park, Kyung Joo; Lee, Joo Hyuk [Kang Nam General HosPital, Public Corporation, Seoul (Korea, Republic of)

    1993-01-15

    We present a case of angiographically confirmed transverse and sigmoid sinus thrombosis, image with MR, in a 20 year old male with a history of otitis media and maxillary sinusitis. T1-weighted image demonstrated an iso signal intensity mass with tubular-shaped low signal intensity in right transverse and sigmoid sinus. The thrombus had high signal intensity on T2-weighted image. The signal intensity of the thrombus on Gd-DTPA enhanced T1-weighted image was unusually high similar to that of transverse sinus. Although dural sinus thrombosis has a non-specific MR signal intensity, findings of MRI in this case may serve as an aid in future evaluation of venous thrombosis.

  6. A Branch-and-Price Algorithm for the Capacitated Arc Routing Problem with Stochastic Demands

    DEFF Research Database (Denmark)

    Christiansen, Christian Holk; Lysgaard, Jens; Wøhlk, Sanne

    2009-01-01

    We address the Capacitated Arc Routing Problem with Stochastic Demands (CARPSD), which we formulate as a Set Partitioning Problem. The CARPSD is solved by a Branch-and-Price algorithm, which we apply without graph transformation. The demand's stochastic nature is incorporated into the pricing...... problem. Computational results are reported....

  7. A novel capacitive detection principle for Coriolis mass flow sensors enabling range/sensitivity tuning

    NARCIS (Netherlands)

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

    2015-01-01

    We report on a novel capacitive detection principle for Coriolis mass flow sensors which allows for one order of magnitude increased sensitivity. The detection principle consists of two pairs of comb-structures: one pair produces two signals with a phase shift directly dependent on the mass flow,

  8. Polymer−metal organic framework composite films as affinity layer for capacitive sensor devices

    NARCIS (Netherlands)

    Sachdeva, S.; Gravesteijn, Dirk J; Soccol, D.; Kapteijn, F.; Sudhölter, E.J.R.; Gascon, J.; Smet, de L.C.P.M.

    2016-01-01

    We report a simple method for sensor development using polymer-MOF composite films. Nanoparticles of NH2-MIL-53(Al) dispersed in a Matrimid polyimide were applied as a thin film on top of capacitive sensor devices with planar electrodes. These drop-cast films act as an affinity layer. Sensing

  9. High capacitance of coarse-grained carbide derived carbon electrodes

    Science.gov (United States)

    Dyatkin, Boris; Gogotsi, Oleksiy; Malinovskiy, Bohdan; Zozulya, Yuliya; Simon, Patrice; Gogotsi, Yury

    2016-02-01

    We report exceptional electrochemical properties of supercapacitor electrodes composed of large, granular carbide-derived carbon (CDC) particles. Using a titanium carbide (TiC) precursor, we synthesized 70-250 μm sized particles with high surface area and a narrow pore size distribution. Electrochemical cycling of these coarse-grained powders defied conventional wisdom that a small particle size is strictly required for supercapacitor electrodes and allowed high charge storage densities, rapid transport, and good rate handling ability. The material showcased capacitance above 100 F g-1 at sweep rates as high as 250 mV s-1 in organic electrolyte. 250-1000 micron thick dense CDC films with up to 80 mg cm-2 loading showed superior areal capacitances. The material significantly outperformed its activated carbon counterpart in organic electrolytes and ionic liquids. Furthermore, large internal/external surface ratio of coarse-grained carbons allowed the resulting electrodes to maintain high electrochemical stability up to 3.1 V in ionic liquid electrolyte. In addition to presenting novel insights into the electrosorption process, these coarse-grained carbons offer a pathway to low-cost, high-performance implementation of supercapacitors in automotive and grid-storage applications.

  10. Improved electronic interfaces for AT-cut quartz crystal microbalance sensors under variable damping and parallel capacitance conditions.

    Science.gov (United States)

    Arnau, A; García, J V; Jimenez, Y; Ferrari, V; Ferrari, M

    2008-07-01

    A new configuration of automatic capacitance compensation (ACC) technique based on an oscillatorlike working interface, which permits the tracking of the series resonant frequency and the monitoring of the motional resistance and the parallel capacitance of a thickness-shear mode quartz crystal microbalance sensor, is introduced. The new configuration permits an easier calibration of the system which, in principle, improves the accuracy. Experimental results are reported with 9 and 10 MHz crystals in liquids with different parallel capacitances which demonstrate the effectiveness of the capacitance compensation. Some frequency deviations from the exact series resonant frequency, measured by an impedance analyzer, are explained by the specific nonideal behavior of the circuit components. A tentative approach is proposed to solve this problem that is also common to previous ACC systems.

  11. FY05 LDRD Final Report, A Revolution in Biological Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, H N; Bajt, S; Balhorn, R; Barty, A; Barsky, D; Bogan, M; Chung, S; Frank, M; Hau-Riege, S; Ishii, H; London, R; Marchesini, S; Noy, A; Segelke, B; Szoke, A; Szoke, H; Trebes, J; Wootton, A; Hajdu, J; Bergh, M; Caleman, C; Huldt, G; Lejon, S; der Spoel, D v; Howells, M; He, H; Spence, J; Nugent, K; Ingerman, E

    2006-01-20

    X-ray free-electron lasers (XFELs) are currently under development and will provide a peak brightness more than 10 orders of magnitude higher than modern synchrotrons. The goal of this project was to perform the fundamental research to evaluate the possibility of harnessing these unique x-ray sources to image single biological particles and molecules at atomic resolution. Using a combination of computational modeling and experimental verification where possible, they showed that it should indeed be possible to record coherent scattering patterns from single molecules with pulses that are shorter than the timescales for the degradation of the structure due to the interaction with those pulses. They used these models to determine the effectiveness of strategies to allow imaging using longer XFEL pulses and to design validation experiments to be carried out at interim ultrafast sources. They also developed and demonstrated methods to recover three-dimensional (3D) images from coherent diffraction patterns, similar to those expected from XFELs. The images of micron-sized test objects are the highest-resolution 3D images of any noncrystalline material ever formed with x-rays. The project resulted in 14 publications in peer-reviewed journals and four records of invention.

  12. Endorectal MRI of the prostate gland. Report of representative images

    Energy Technology Data Exchange (ETDEWEB)

    Sugimura, Yoshiki; Arima, Kiminobu; Hayashi, Norio; Hioki, Takuichi; Ogawa, Kazuhiko; Kinbara, Hiroyuki; Yanagawa, Makoto; Tochigi, Hiromi; Kawamura, Juichi [Mie Univ., Tsu (Japan). School of Medicine

    1997-02-01

    Endorectal magnetic resonance imaging (MRI) by endorectal surface coil has been recently introduced for visualizing the prostate gland. Thirty patients with benign or malignant prostate disease were examined by this new modality. The intra-glandular zonal anatomy (Transition zone, TZ; Peripheral Zone, PZ) can be clearly visualized on T2-weighted images in normal prostate glands. Benign prostatic hypertrophy is shown as a low heterogeneous signal area in the TZ on T2-weighted imaging. Prostate cancer is shown as a low-signal area within the PZ on T2-weighted imaging. Clear images of the prostatic capsule and the neurovascular bundle seen on the surface coil may contribute to the local staging of prostate cancer. Invasion of the seminal vesicle by prostate cancer is displayed as an enhanced septal pattern with enriched gadolinium. However, localization of the cancer lesion within the prostate gland could not be clearly detected by gadolinium enhancement. Prospective tumor staging by the endorectal surface coil MRI was 75% accurate, this being confirmed by histopathological examinations of 8 prostate glands obtained during radical prostatectomies. We concluded that endorectal MRI can greatly contribute to diagnosing the pathological condition of the prostate gland. (author)

  13. HDlive rendering images of the fetal stomach: a preliminary report.

    Science.gov (United States)

    Inubashiri, Eisuke; Abe, Kiyotaka; Watanabe, Yukio; Akutagawa, Noriyuki; Kuroki, Katumaru; Sugawara, Masaki; Maeda, Nobuhiko; Minami, Kunihiro; Nomura, Yasuhiro

    2015-01-01

    This study aimed to show reconstruction of the fetal stomach using the HDlive rendering mode in ultrasound. Seventeen healthy singleton fetuses at 18-34 weeks' gestational age were observed using the HDlive rendering mode of ultrasound in utero. In all of the fetuses, we identified specific spatial structures, including macroscopic anatomical features (e.g., the pyrous, cardia, fundus, and great curvature) of the fetal stomach, using the HDlive rendering mode. In particular, HDlive rendering images showed remarkably fine details that appeared as if they were being viewed under an endoscope, with visible rugal folds after 27 weeks' gestational age. Our study suggests that the HDlive rendering mode can be used as an additional method for evaluating the fetal stomach. The HDlive rendering mode shows detailed 3D structural images and anatomically realistic images of the fetal stomach. This technique may be effective in prenatal diagnosis for examining detailed information of fetal organs.

  14. Imaging Finding of Multiple Endocrine Neoplasia Type 1: Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Yum, Tae Jun; Cho, Hee Woo [Dept. of Radiology, Yonsei University, College of Medicine, Seoul (Korea, Republic of)

    2012-08-15

    Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant inherited syndrome with characteristic clinical and radiological manifestations. Many reports on MEN1 have been published; however, no cases of radiologically diagnosed MEN1 have been reported. Therefore, we report on a radiologically diagnosed case of MEN1 with clinical symptoms of gastroduodenal ulcer.

  15. Chloride Is Essential for Capacitation and for the Capacitation-associated Increase in Tyrosine Phosphorylation*

    Science.gov (United States)

    Wertheimer, Eva V.; Salicioni, Ana M.; Liu, Weimin; Trevino, Claudia L.; Chavez, Julio; Hernández-González, Enrique O.; Darszon, Alberto; Visconti, Pablo E.

    2008-01-01

    After epididymal maturation, sperm capacitation, which encompasses a complex series of molecular events, endows the sperm with the ability to fertilize an egg. This process can be mimicked in vitro in defined media, the composition of which is based on the electrolyte concentration of the oviductal fluid. It is well established that capacitation requires Na+, \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\usepackage[Euler]{upgreek} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{HCO}}_{3}^{-}\\end{equation*}\\end{document}, Ca2+, and a cholesterol acceptor; however, little is known about the function of Cl– during this important process. To determine whether Cl–, in addition to maintaining osmolarity, actively participates in signaling pathways that regulate capacitation, Cl– was replaced by either methanesulfonate or gluconate two nonpermeable anions. The absence of Cl– did not affect sperm viability, but capacitation-associated processes such as the increase in tyrosine phosphorylation, the increase in cAMP levels, hyperactivation, the zona pellucidae-induced acrosome reaction, and most importantly, fertilization were abolished or significantly reduced. Interestingly, the addition of cyclic AMP agonists to sperm incubated in Cl–-free medium rescued the increase in tyrosine phosphorylation and hyperactivation suggesting that Cl– acts upstream of the cAMP/protein kinase A signaling pathway. To investigate Cl– transport, sperm incubated in complete capacitation medium were exposed to a battery of anion transport inhibitors. Among them, bumetanide and furosemide, two blockers of Na+/K+/Cl– cotransporters (NKCC), inhibited all capacitation-associated events, suggesting that these transporters may mediate Cl– movements in sperm. Consistent with these results, Western blots

  16. Final Project Report: Imaging Fault Zones Using a Novel Elastic Reverse-Time Migration Imaging Technique

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Lianjie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chen, Ting [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tan, Sirui [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lin, Youzuo [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gao, Kai [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-10

    Imaging fault zones and fractures is crucial for geothermal operators, providing important information for reservoir evaluation and management strategies. However, there are no existing techniques available for directly and clearly imaging fault zones, particularly for steeply dipping faults and fracture zones. In this project, we developed novel acoustic- and elastic-waveform inversion methods for high-resolution velocity model building. In addition, we developed acoustic and elastic reverse-time migration methods for high-resolution subsurface imaging of complex subsurface structures and steeply-dipping fault/fracture zones. We first evaluated and verified the improved capabilities of our newly developed seismic inversion and migration imaging methods using synthetic seismic data. Our numerical tests verified that our new methods directly image subsurface fracture/fault zones using surface seismic reflection data. We then applied our novel seismic inversion and migration imaging methods to a field 3D surface seismic dataset acquired at the Soda Lake geothermal field using Vibroseis sources. Our migration images of the Soda Lake geothermal field obtained using our seismic inversion and migration imaging algorithms revealed several possible fault/fracture zones. AltaRock Energy, Inc. is working with Cyrq Energy, Inc. to refine the geologic interpretation at the Soda Lake geothermal field. Trenton Cladouhos, Senior Vice President R&D of AltaRock, was very interested in our imaging results of 3D surface seismic data from the Soda Lake geothermal field. He planed to perform detailed interpretation of our images in collaboration with James Faulds and Holly McLachlan of University of Nevada at Reno. Using our high-resolution seismic inversion and migration imaging results can help determine the optimal locations to drill wells for geothermal energy production and reduce the risk of geothermal exploration.

  17. Advanced Computer Image Generation Techniques Exploiting Perceptual Characteristics. Final Report.

    Science.gov (United States)

    Stenger, Anthony J.; And Others

    This study suggests and identifies computer image generation (CIG) algorithms for visual simulation that improve the training effectiveness of CIG simulators and identifies areas of basic research in visual perception that are significant for improving CIG technology. The first phase of the project entailed observing three existing CIG simulators.…

  18. Adaptive optics instrument for long-range imaging. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, T.M.

    1998-06-01

    The science and history of imaging through a turbulent atmosphere is reviewed in detail. Traditional methods for reducing the effects of turbulence are presented. A simplified method for turbulence reduction called the Sheared Coherent Interferometric Photography (SCIP) method is presented. Implementation of SCIP is discussed along with experimental results. Limitations in the use of this method are discussed along with recommendations for future improvements.

  19. MR imaging finding of xanthogranulomatous cholecystitis: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Gyee; Kang, Heoung Keun; Jeong, Yong Yeon; Cho, Yong Ho; Jang, Nam Kyu [Chonnam Univ. Medical School, Kwangju (Korea, Republic of)

    1999-07-01

    We describe a case of xanthogranulomatous cholecystitis in which there was close correlation between MR and histopathological finding and review the previous literature. On both T1- and T2-weighted MR images, multiple gallstones and diffuse wall thickening of the gallbladder were seen, with multiple hyperintense intramural nodules. The nodules were pathologically confirmed as xanthogranuloma.

  20. The role of actin in capacitation-related signaling: an in silico and in vitro study

    Directory of Open Access Journals (Sweden)

    Lucidi Pia

    2011-03-01

    Full Text Available Abstract Background The signalling cascades involved in many biological processes require the coordination of different subcellular districts. It is the case of the pathways involved in spermatozoa acquisition of fertilizing ability (the so called "capacitation". In the present work the coordination of subcellular signalling, during the boar sperm capacitation, was studied by a computational and experimental approach. As first the biological network representing all the molecular interactions involved in capacitation was build and analyzed, then, an experimental set up was carried out to confirm the computational model-based prediction. Results The analysis of computational model pointed out that the "actin polymerization" node had some important and unique features: - it is one of the most connected nodes, - it links in a specific manner all the intracellular compartments, - its removal from the network did not affect the global network topology but caused the loss of five important nodes (and among them the "plasma membrane" and "outer acrosome membrane" fusion. Thus, it was suggested that actin polymerization could be involved in the signaling coordination of different subcellular districts, and that its functional ablation could compromise spermatozoa ability to complete the capacitation (while the main signaling pathway remained unaffected. The experiments, carried out inhibiting the actin polymerization in capacitating boar spermatozoa by the administration of cytocalasin D (CD, demonstrated that the CD treatment inhibited spermatozoa ability to reach the full fertilizing ability, while, the examined signaling pathways (membrane acquisition of chlortetracicline pattern C, protein tyrosine phosphorylation, phospholipase C-γ1 relocalization, intracellular calcium response to zonae pellucidae remained effective, thus, confirming the model-based hypothesis. Conclusions The model based-hypothesis was confirmed by the reported data obtained

  1. The BSA-induced Ca(2+ influx during sperm capacitation is CATSPER channel-dependent

    Directory of Open Access Journals (Sweden)

    Ren Dejian

    2009-10-01

    Full Text Available Abstract Background Serum albumin is a key component in mammalian sperm capacitation, a functional maturation process by which sperm become competent to fertilize oocytes. Capacitation is accompanied by several cellular and molecular changes including an increased tyrosine phosphorylation of sperm proteins and a development of hyperactivated sperm motility. Both of these processes require extracellular calcium, but how calcium enters sperm during capacitation is not well understood. Methods BSA-induced changes in intracellular calcium concentration were studied using Fluo-4 and Fura-2 calcium imaging with wild-type and Catsper1 knockout mouse sperm. Results We found that the fast phase of the BSA-induced rises in intracellular calcium concentration was absent in the Catsper1 knockout sperm and could be restored by an EGFP-CATSPER1 fusion protein. The calcium concentration increases were independent of G-proteins and phospholipase C but could be partially inhibited when intracellular pH was clamped. The changes started in the principal piece and propagated toward the sperm head. Conclusion We conclude that the initial phase of the increases in intracellular calcium concentration induced by BSA requires the CATSPER channel, but not the voltage-gated calcium channel. Our findings identify the molecular conduit responsible for the calcium entry required for the sperm motility changes that occur during capacitation.

  2. SERS imaging of cell-surface biomolecules metabolically labeled with bioorthogonal Raman reporters.

    Science.gov (United States)

    Xiao, Ming; Lin, Liang; Li, Zefan; Liu, Jie; Hong, Senlian; Li, Yaya; Zheng, Meiling; Duan, Xuanming; Chen, Xing

    2014-08-01

    Live imaging of biomolecules with high specificity and sensitivity as well as minimal perturbation is essential for studying cellular processes. Here, we report the development of a bioorthogonal surface-enhanced Raman scattering (SERS) imaging approach that exploits small Raman reporters for visualizing cell-surface biomolecules. The cells were cultured and imaged by SERS microscopy on arrays of Raman-enhancing nanoparticles coated on silicon wafers or glass slides. The Raman reporters including azides, alkynes, and carbondeuterium bonds are small in size and spectroscopically bioorthogonal (background-free). We demonstrated that various cell-surface biomolecules including proteins, glycans, and lipids were metabolically incorporated with the corresponding precursors bearing a Raman reporter and visualized by SERS microscopy. The coupling of SERS microscopy with bioorthogonal Raman reporters expands the capabilities of live-cell microscopy beyond the modalities of fluorescence and label-free imaging.

  3. Stray Capacitances of an Air-Cored Eddy Current Sensor

    Directory of Open Access Journals (Sweden)

    Yi Jia

    2009-12-01

    Full Text Available Stray capacitance of an air-cored eddy current sensor is one of the most crucial issues for successful development of an eddy current based residual stress assessment technology at frequency above 50 MHz. A two dimensional finite element model and an equivalent lumped capacitance network have been developed to accurately quantify overall stray capacitances of an air-cored eddy current sensor with specimen being tested. A baseline model was used to evaluate sensor design parameters, including the effects of pitch distance, trace width, trace thickness, number of turns, inner diameter, substrate thickness, lift-off distance, and dielectric constant of shim on the stray capacitances of the sensor. The results clearly indicate that an appropriate sensor design parameters could reduce the stray capacitance and improve the sensor performance. This research opens up a new design space to minimize stray capacitance effect and improve the sensor sensitivity and its lift-off uncertainty at elevated high frequencies.

  4. Tunable Lowpass Filter with RF MEMS Capacitance and Transmission Line

    Directory of Open Access Journals (Sweden)

    Shimul C. Saha

    2012-01-01

    Full Text Available We have presented an RF MEMS tuneable lowpass filter. Both distributed transmission lines and RF MEMS capacitances were used to replace the lumped elements. The use of RF MEMS capacitances gives the flexibility of tuning the cutoff frequency of the lowpass filter. We have designed a low-pass filter at 9–12 GHz cutoff frequency using the theory of stepped impedance transmission lines. A prototype of the filter has been fabricated using parallel plate capacitances. The variable shunt capacitances are formed by a combination of a number of parallel plate RF MEMS capacitances. The cutoff frequency is tuned from C to X band by actuating different combinations of parallel capacitive bridges. The measurement results agree well with the simulation result.

  5. Numerical analysis of capacitive pressure micro-sensors

    Institute of Scientific and Technical Information of China (English)

    WANG; Xiaomin; LI; Mingxuan; WANG; Chenghao

    2005-01-01

    Pseudo-spectral method is used to numerically model the diaphragm deflection of capacitive pressure micro-sensor under uniform load. The relationship between the capacitance of the micro-sensor and the load is then analyzed after the description of the computational principle. For normal mode micro-sensor, the tensile force on the diaphragm can be ignored and thereby the capacitance increases linearly with the load increase only when the load is so small that the resultant deflection is less than the diaphragm thickness. The linear relationship between the capacitance and the load turns to be nonlinear thereafter and the capacitance rises dramatically with the constant increase of the load. For touch mode micro-sensor, an algorithm to determine the touch radius of the diaphragm and substrate is presented and the curve of capacitance versus load is shown on the numerical results laying a theoretical foundation for micro-sensor design.

  6. Dynamic Characteristics of X-pinch Experiments Conducted in a Small Capacitive Generator:Refractive Optical Observations.

    Science.gov (United States)

    Sepúlveda, Adolfo; Pavez, Cristian; Pedreros, José; Avaria, Gonzalo; San Martín, Patricio; Soto, Leopoldo

    2016-05-01

    Among the dense plasmas configurations of interest for applications as a portable intense source of X-rays, the X-pinches are the most attractive by their brightness, source size, short duration and space localization, being particularly reproducible when they are conducted with fast pulsed power generators. In recent time, several characteristics of the dynamics and emission have been reproduced in compact generators (typically capacitive generators) of low current rise-rate (less than 0.5 kA/ns). In this work, a preliminary characterization of the dynamic of X-pinch plasma conducted in a small capacitive generator is reported. In order to obtain the plasma dynamics and quantitative information of the plasma density, the dark field Schlieren technique and interferometry were implemented. The experiments were carried out on the multipurpose generator (1.2 μF, 345 J, 47.5 nH, T/4=375 ns and Z = 0.2 Ω in short circuit) capable to produce currents up to 122 kA with 500 ns quarter period, when a charging voltage of 24 kV and metallic X-pinches are used as load. The electrical behavior of the discharge and the X-ray emission are monitored with a Rogowski coil and filtered PIN diodes respectively. For the refractive optical diagnostics a 532 nm frequency- doubled Nd-YAG laser was used. As from a single Schlieren record per shot, a sequence with the time evolution of the plasma is constructed. From the images, a similar dynamic of X- pinches conducted in fast generators of high current is observed, where structures such as coronal plasma, plasma flares and plasma jets are identified. The plasma dynamics observed from a VUV gated pinhole image system is compared with registered dynamic with refractive optical techniques.

  7. Using NLP to identify cancer cases in imaging reports drawn from radiology information systems.

    Science.gov (United States)

    Patrick, Jon; Asgari, Pooyan; Li, Min; Nguyen, Dung

    2013-01-01

    A Natural Language processing (NLP) classifier has been developed for the Victorian and NSW Cancer Registries with the purpose of automatically identifying cancer reports from imaging services, transmitting them to the Registries and then extracting pertinent cancer information. Large scale trials conducted on over 40,000 reports show the sensitivity for identifying reportable cancer reports is above 98% with a specificity above 96%. Detection of tumour stream, report purpose, and a variety of extracted content is generally above 90% specificity. The differences between report layout and authoring strategies across imaging services appear to require different classifiers to retain this high level of accuracy. Linkage of the imaging data with existing registry records (hospital and pathology reports) to derive stage and recurrence of cancer has commenced and shown very promising results.

  8. CMOS MEMS capacitive absolute pressure sensor

    Science.gov (United States)

    Narducci, M.; Yu-Chia, L.; Fang, W.; Tsai, J.

    2013-05-01

    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 SiO2 membrane, which acts as a movable electrode against a bottom or stationary Al electrode fixed on the SiO2 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.

  9. 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.

  10. Magnetic field tunable capacitive dielectric:ionic-liquid sandwich composites

    Science.gov (United States)

    Wu, Ye; Bhalla, Amar; Guo, Ruyan

    2016-03-01

    We examined the tunability of the capacitance for GaFeO3-ionic liquid-GaFeO3 composite material by external magnetic and electric field. Up to 1.6 folds of capacitance tunability could be achieved at 957 kHz with voltage 4 V and magnetic field 0.02 T applied. We show that the capacitance enhancement is due to the polarization coupling between dielectric layer and ionic liquid layer.

  11. 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.

  12. In vivo imaging agents: an international market report

    Energy Technology Data Exchange (ETDEWEB)

    1990-03-01

    The purpose of this study is to provide a global perspective of the in vivo imaging agents business to market planning executives who are working for companies that develop, produce and distribute various types of in vivo imaging agents. Others that could find this study useful include investment bankers, regulatory and governmental authorities and purchasers of these products. The study attempts to diligently provide market data by type for important geographic markets - Western Europe, the U.S.A., and Japan. A competitive intelligence section which discusses companies involved in these markets constitutes the last part of this study. These profiles are not intended to extensively evaluate each company's marketing strengths or strategies but to provide a general idea of the market presence and prospects. A combination of primary and secondary research is used for all findings. (author).

  13. Imaging of Primary Liver Carcinosarcoma Scintigraphically; A Case Report

    Directory of Open Access Journals (Sweden)

    Ümmühan Abdulrezzak

    2014-02-01

    Full Text Available Primary liver carcinosarcoma is a very rare disease. There have been only a few cases described to date, none of which has been imaged by bone scintigraphy. A 69-year-old man who developed right back pain and weight loss was admitted to our hospital. Tenderness of the right upper abdomen, hepatomegaly, and a giant mass were the main physical examination signs. Abdominal ultrasonography showed a large lobulated heterogeneous echogenic solid mass with multiple cystic areas of varying size and a highly echogenic region that had posterior acoustic shadowing within the mass in the right lobe of the liver. Labeled erythrocyte imaging and 99mTc-nanocolloid liver-spleen scan were performed to exclude hemangioma, showing a large intrahepatic photon deficient area. 99mTcmethylene diphosphonate (MDP bone scintigraphy revealed heterogeneous, irregular and dense activity accumulation thought to be osteoblastic activity in the liver mass. Postsurgical pathological diagnosis revealed “carcinosarcoma”.

  14. Capacitive tool standoff sensor for dismantlement tasks

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, D.J.; Weber, T.M. [Sandia National Labs., Albuquerque, NM (United States); Liu, J.C. [Univ. of Illinois, Urbana, IL (United States)

    1996-12-31

    A capacitive sensing technology has been applied to develop a Standoff Sensor System for control of robotically deployed tools utilized in Decontamination and Dismantlement (D and D) activities. The system combines four individual sensor elements to provide non-contact, multiple degree-of-freedom control of tools at distances up to five inches from a surface. The Standoff Sensor has been successfully integrated to a metal cutting router and a pyrometer, and utilized for real-time control of each of these tools. Experiments demonstrate that the system can locate stationary surfaces with a repeatability of 0.034 millimeters.

  15. Evaluation of the contribution of radiological imaging to the final diagnosis in medical case reports.

    Science.gov (United States)

    Wiesinger, Isabel; Scharf, Gregor; Platz, Natascha; Dendl, Lena M; Pawlik, Michael T; Stroszczynski, Christian; Schreyer, Andreas G

    2015-05-01

    To evaluate the clinical value and impact of radiological imaging in published medial case reports. We analysed 671 consecutively published case reports of a peer-reviewed medical journal for case reports. The general use of radiological imaging as well as the specific imaging modality used in each case (ultrasound, x-ray, fluoroscopy, CT, MRI) was documented, and most importantly the 'final problem solver', i.e. the diagnostic modality giving the final clue to the patient's diagnosis, was identified. In 511 of 671 (76.1 %) analysed case reports at least one radiological modality was used in the diagnostic cascade. In 28.6% of all cases the final diagnosis was achieved by radiological imaging. All other cases were solved by the patient's history and physical examination (15.2%), histology (12.4%), and blood analysis (9.6%). When radiology was the 'final problem solver', it was mainly CT (51.6%) and MRI (30.6%). In 52.2% of the case reports the radiological image was included in the article. In case reports published in a prominent general medical journal radiological imaging is an important key player in the diagnostic process. In many cases, it is also the diagnostic tool which ultimately leads to determining the final diagnosis. • Radiology was the most important specialty for finding the final diagnosis. • CT was the most successful problem-solving imaging modality followed by MRI. • MRI and CT had the best solution rates of more than 30%.

  16. Automated semantic indexing of imaging reports to support retrieval of medical images in the multimedia electronic medical record.

    Science.gov (United States)

    Lowe, H J; Antipov, I; Hersh, W; Smith, C A; Mailhot, M

    1999-12-01

    This paper describes preliminary work evaluating automated semantic indexing of radiology imaging reports to represent images stored in the Image Engine multimedia medical record system at the University of Pittsburgh Medical Center. The authors used the SAPHIRE indexing system to automatically identify important biomedical concepts within radiology reports and represent these concepts with terms from the 1998 edition of the U.S. National Library of Medicine's Unified Medical Language System (UMLS) Metathesaurus. This automated UMLS indexing was then compared with manual UMLS indexing of the same reports. Human indexing identified appropriate UMLS Metathesaurus descriptors for 81% of the important biomedical concepts contained in the report set. SAPHIRE automatically identified UMLS Metathesaurus descriptors for 64% of the important biomedical concepts contained in the report set. The overall conclusions of this pilot study were that the UMLS metathesaurus provided adequate coverage of the majority of the important concepts contained within the radiology report test set and that SAPHIRE could automatically identify and translate almost two thirds of these concepts into appropriate UMLS descriptors. Further work is required to improve both the recall and precision of this automated concept extraction process.

  17. Imaging findings of desmoplastic fibroma rarely involoving the clavicle: Case report

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Dong Min; Juhng, Seon Kwan; Sohn, Young Jun; Kim, Hun Soo [Wonkwang University School of Medicine and Hospital, Iksan (Korea, Republic of)

    2014-02-15

    Desmoplastic fibroma of bone is a rare locally aggressive, but non-metastatic tumor. In this case report, we present a desmoplastic fibroma in an unusual location, the clavicle. Desmoplastic fibroma involving the clavicle is extremely rare, with only 2 reported cases before 1985. We report the imaging findings of a desmoplastic fibroma of the clavicle with a review of the relevant literature.

  18. Evaluation of excitation strategy with multi-plane electrical capacitance tomography sensor

    Science.gov (United States)

    Mao, Mingxu; Ye, Jiamin; Wang, Haigang; Zhang, Jiaolong; Yang, Wuqiang

    2016-11-01

    Electrical capacitance tomography (ECT) is an imaging technique for measuring the permittivity change of materials. Using a multi-plane ECT sensor, three-dimensional (3D) distribution of permittivity may be represented. In this paper, three excitation strategies, including single-electrode excitation, dual-electrode excitation in the same plane, and dual-electrode excitation in different planes are investigated by numerical simulation and experiment for two three-plane ECT sensors with 12 electrodes in total. In one sensor, the electrodes on the middle plane are in line with the others. In the other sensor, they are rotated 45° with reference to the other two planes. A linear back projection algorithm is used to reconstruct the images and a correlation coefficient is used to evaluate the image quality. The capacitance data and sensitivity distribution with each measurement strategy and sensor model are analyzed. Based on simulation and experimental results using noise-free and noisy capacitance data, the performance of the three strategies is evaluated.

  19. Design and Test of Capacitive Micromachined Ultrasonic Transducer

    National Research Council Canada - National Science Library

    Hongliang Wang; Xiangjun Wang; Changde He; Chenyang Xue; Jijun Xiong; Wendong Zhang; Jing Miao; Yuping Li

    2014-01-01

      Currently, most capacitive micromachined ultrasound transducers, adopting surface sacrificial technology encounter various problems such as difficult cavity etch, low controllability of membrane thickness etc...

  20. A capacitive biosensor based on an interdigitated electrode with nanoislands.

    Science.gov (United States)

    Jung, Ha-Wook; Chang, Young Wook; Lee, Ga-yeon; Cho, Sungbo; Kang, Min-Jung; Pyun, Jae-Chul

    2014-09-24

    A capacitive biosensor based on an interdigitated electrode (IDE) with nanoislands was developed for label-free detection of antigen-antibody interactions. To enable sensitive capacitive detection of protein adsorption, the nanoislands were fabricated between finger electrodes of the IDE. The effect of the nanoislands on the sensitive capacitive measurement was estimated using horseradish peroxidase (HRP) as a model protein. Additionally, a parylene-A film was coated on the IDE with nanoislands to improve the efficiency of protein immobilization. By using HRP and hepatitis B virus surface antigen (HBsAg) as model analytes, the effect of the parylene-A film on the capacitive detection of protein adsorption was demonstrated.

  1. Dental Implant Placement using C-arm CT Real Time Imaging System: A Case Report.

    Science.gov (United States)

    Rajkumar, B; Boruah, Lalit C; Thind, Amandeep; Jain, Gaurav; Gupta, Shilpi

    2014-12-01

    C-arm computed tomography (CT) is a new and innovative imaging technique. In combination with two-dimensional fluoroscopic or radiographic imaging, information provided by three-dimensional C-arm real time imaging can be valuable for therapy planning, guidance and outcome assessment in dental implant placement. This paper reports a case of two dental implant placement using Artis zee C-arm CT system first time in field of implantology.

  2. Ultrahigh-rate supercapacitors with large capacitance based on edge oriented graphene coated carbonized cellulous paper as flexible freestanding electrodes

    Science.gov (United States)

    Ren, Guofeng; Li, Shiqi; Fan, Zhao-Xia; Hoque, Md Nadim Ferdous; Fan, Zhaoyang

    2016-09-01

    Large-capacitance and ultrahigh-rate electrochemical supercapacitors (UECs) with frequency response up to kilohertz (kHz) range are reported using light, thin, and flexible freestanding electrodes. The electrode is formed by perpendicularly edge oriented multilayer graphene/thin-graphite (EOG) sheets grown radially around individual fibers in carbonized cellulous paper (CCP), with cellulous carbonization and EOG deposition implemented in one step. The resulted ∼10 μm thick EOG/CCP electrode is light and flexible. The oriented porous structure of EOG with large surface area, in conjunction with high conductivity of the electrode, ensures ultrahigh-rate performance of the fabricated cells, with large areal capacitance of 0.59 mF cm-2 and 0.53 mF cm-2 and large phase angle of -83° and -80° at 120 Hz and 1 kHz, respectively. Particularly, the hierarchical EOG/CCP sheet structure allows multiple sheets stacked together for thick electrodes with almost linearly increased areal capacitance while maintaining the volumetric capacitance nearly no degradation, a critical merit for developing practical faraday-scale UECs. 3-layers of EOG/CCP electrode achieved an areal capacitance of 1.5 mF cm-2 and 1.4 mF cm-2 at 120 Hz and 1 kHz, respectively. This demonstration moves a step closer to the goal of bridging the frequency/capacitance gap between supercapacitors and electrolytic capacitors.

  3. Facile preparation of polypyrrole/graphene oxide nanocomposites with large areal capacitance using electrochemical codeposition for supercapacitors

    Science.gov (United States)

    Zhou, Haihan; Han, Gaoyi; Xiao, Yaoming; Chang, Yunzhen; Zhai, Hua-Jin

    2014-10-01

    A simple and low-cost electrochemical codeposition method has been introduced to fabricate polypyrrole/graphene oxide (PPy/GO) nanocomposites and the areal capacitance of conducting polymer/GO composites is reported for the first time. Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) are implemented to determine the PPy/GO nanocomposites are successfully prepared and the interaction between PPy and GO. The as-prepared PPy/GO nanocomposites show the curly sheet-like morphology, superior capacitive behaviors and cyclic stability. Furthermore, the varying deposition time is implemented to investigate the impact of the loading amount on electrochemical behavior of the composites, and a high areal capacitance of 152 mF cm-2 is achieved at 10 mV s-1 CV scan. However, the thicker films caused by the long deposition time would result in larger diffusion resistance of electrolyte ions, consequently exhibit the relatively lower capacitance value at the high current density. The GCD tests indicate moderate deposition time is more suitable for the fast charge/discharge. Considering the very simple and effective synthetic process, the PPy/GO nanocomposites with relatively high areal capacitance are competitive candidate for supercapacitor application, and its capacitive performances can be easily tuned by varying the deposition time.

  4. Capacitive immunosensor for C-reactive protein quantification

    KAUST Repository

    Sapsanis, Christos

    2015-08-02

    We report an agglutination-based immunosensor for the quantification of C-reactive protein (CRP). The developed immunoassay sensor requires approximately 15 minutes of assay time per sample and provides a sensitivity of 0.5 mg/L. We have measured the capacitance of interdigitated electrodes (IDEs) and quantified the concentration of added analyte. The proposed method is a label free detection method and hence provides rapid measurement preferable in diagnostics. We have so far been able to quantify the concentration to as low as 0.5 mg/L and as high as 10 mg/L. By quantifying CRP in serum, we can assess whether patients are prone to cardiac diseases and monitor the risk associated with such diseases. The sensor is a simple low cost structure and it can be a promising device for rapid and sensitive detection of disease markers at the point-of-care stage.

  5. Improved Circuits with Capacitive Feedback for Readout Resistive Sensor Arrays

    Directory of Open Access Journals (Sweden)

    Óscar Oballe-Peinado

    2016-01-01

    Full Text Available One of the most suitable ways of distributing a resistive sensor array for reading is an array with M rows and N columns. This allows reduced wiring and a certain degree of parallelism in the implementation, although it also introduces crosstalk effects. Several types of circuits can carry out the analogue-digital conversion of this type of sensors. This article focuses on the use of operational amplifiers with capacitive feedback and FPGAs for this task. Specifically, modifications of a previously reported circuit are proposed to reduce the errors due to the non-idealities of the amplifiers and the I/O drivers of the FPGA. Moreover, calibration algorithms are derived from the analysis of the proposed circuitry to reduce the crosstalk error and improve the accuracy. Finally, the performances of the proposals is evaluated experimentally on an array of resistors and for different ranges.

  6. Fabricating Capacitive Micromachined Ultrasonic Transducers with Wafer Bonding Technique

    Directory of Open Access Journals (Sweden)

    Anil ARORA

    2008-06-01

    Full Text Available We report the fabrication of capacitive micromachined ultrasonic transducer by wafer bonding technique. Membrane is transferred from SOI wafer to the prime wafer having silicon dioxide cavity. The thickness of cavity height depends on silicon dioxide grown on prime wafer by dry/wet oxidation. Thinning of device wafer of SOI by oxidation, controls membrane thickness. Two wafers are bonded in vacuum under optimized controlled parameters. Using this method, we can get single crystal silicon as membrane, whose mechanical and electrical parameters are well known. Silicon membrane is free from stress and density variation. Focused Ion Beam etching and laser Doppler Vibrometer were used to do structural and electrical characterization respectively. The measured resonance frequency of fabricated device i.e. 2.24 MHz is much closer to the designed value i.e. 2.35 MHz.

  7. Anodic bonding using SOI wafer for fabrication of capacitive micromachined ultrasonic transducers

    Science.gov (United States)

    Bellaredj, M.; Bourbon, G.; Walter, V.; Le Moal, P.; Berthillier, M.

    2014-02-01

    In medical ultrasound imaging, mostly piezoelectric crystals are used as ultrasonic transducers. Capacitive micromachined ultrasonic transducers (CMUTs) introduced around 1994 have been shown to be a good alternative to conventional piezoelectric transducers in various aspects, such as sensitivity, transduction efficiency or bandwidth. This paper focuses on a fabrication process for CMUTs using anodic bonding of a silicon on insulator wafer on a glass wafer. The processing steps are described leading to a good control of the mechanical response of the membrane. This technology makes possible the fabrication of large membranes and can extend the frequency range of CMUTs to lower frequencies of operation. Silicon membranes having radii of 50, 70, 100 and 150 µm and a 1.5 µm thickness are fabricated and electromechanically characterized using an auto-balanced bridge impedance analyzer. Resonant frequencies from 0.6 to 2.3 MHz and an electromechanical coupling coefficient around 55% are reported. The effects of residual stress in the membranes and uncontrolled clamping conditions are clearly responsible for the discrepancies between experimental and theoretical values of the first resonance frequency. The residual stress in the membranes is determined to be between 90 and 110 MPa. The actual boundary conditions are between the clamped condition and the simply supported condition and can be modeled with a torsional stiffness of 2.10-7 Nm rad-1 in the numerical model.

  8. Magnetic resonance imaging findings in Lhermitte-Duclos disease: reports of three cases

    Institute of Scientific and Technical Information of China (English)

    XU Lei; GAO Pei-yi; LIN Yan; TIAN Tong-de; LEI Jing; MA Li

    2005-01-01

    @@ Lhermitte-Duclos disease (LDD), or dysplastic gangliocytoma of the cerebellum, is a rare hamartomatous lesion characterized by a slowly enlarging mass within the cerebellar cortex. The disease reveals unique appearance on magnetic resonance imaging (MRI). Recognition of the imaging features makes the correct diagnosis possible even without a pathological examination. Three cases are presented and analyzed in this report.

  9. Medical imaging findings in Cobb syndrome: two case reports

    Institute of Scientific and Technical Information of China (English)

    WANG Guang-bin; XU Lei; ZHAO Bin; CAI Shi-feng; SHI Hao; LI Hui-hua; QU Lei

    2005-01-01

    @@ Cobb syndrome, also known as cutaneomeningospinal angiomatosis, is a rare clinical entity characterized by the combination of a vascular skin nevus and an angioma in the spinal canal at the same metamere.1 It was first described by Berenbruch in 1890 and did not receive recognition until Cobb's description2 in 1915. Only few documents about this disease had been reported.1 We present two cases here and review the other reported cases.

  10. Rational use of diagnostic imaging in paediatrics. The report of a World Health Organization study group

    Energy Technology Data Exchange (ETDEWEB)

    Merten, D.F.; Palmer, P.E.S.; Sweet, E.M.; Fendel, H.; Faure, C.; Fujioka, M.

    1989-05-01

    The purpose of WHO Technical Report 757 is to provide guidance to physicians who must decide what imaging techniques are best suited to specific clinical problems in paediatric practice, and to those who perform these various diagnostic procedures.

  11. Dark Energy Studies with LSST Image Simulations, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, John Russell [Purdue Univ., West Lafayette, IN (United States)

    2016-07-26

    This grant funded the development and dissemination of the Photon Simulator (PhoSim) for the purpose of studying dark energy at high precision with the upcoming Large Synoptic Survey Telescope (LSST) astronomical survey. The work was in collaboration with the LSST Dark Energy Science Collaboration (DESC). Several detailed physics improvements were made in the optics, atmosphere, and sensor, a number of validation studies were performed, and a significant number of usability features were implemented. Future work in DESC will use PhoSim as the image simulation tool for data challenges used by the analysis groups.

  12. Facial nerve neuromas: MR imaging. Report of four cases

    Energy Technology Data Exchange (ETDEWEB)

    Martin, N. (G.H. Pitie-Salpetriere, 75 - Paris (France). Dept. of Neuroradiology); Sterkers, O. (Hospital Beaujon, Clichy (France). Dept. of Otorhinolaryngology); Mompoint, D.; Nahum, H. (Hopital Beaujon, Clichy (France). Dept. of Radiology)

    1992-02-01

    Four cases of facial nerve neuroma were evaluated by computed tomographic (CT) scan and magnetic resonance imaging (MRI). The extension of the tumor in the petrous bone or the parotid gland was well defined by MRI in all cases. CT scan was useful to demonstrate bone erosions and the relation of the tumor to inner ear structures. In cases of progressive facial palsy, CT and MRI should be combined to detect a facial neuroma and to plan the surgical approach for tumor removal and nerve grafting. (orig.).

  13. The Osiris Tunable Imager and Spectrograph: a 2004 Status Report

    Directory of Open Access Journals (Sweden)

    J. Cepa

    2005-01-01

    Full Text Available OSIRIS (Optical System for Imaging and low Resolution Integrated Spectroscopy constituye el instrumento óptico de Día Uno del GTC y el único instrumento de Día a Uno español. Dado que los calendarios del telescopio y del instrumento van paralelos y sincronizados, OSIRIS estará disponible en cuanto el GTC esté preparado para empezar su operación científica. En el presente artículo se pasa revista al estado del instrumento a mediados de 2004.

  14. Nanostructured conducting polymer based reagentless capacitive immunosensor.

    Science.gov (United States)

    Bandodkar, Amay Jairaj; Dhand, Chetna; Arya, Sunil K; Pandey, M K; Malhotra, Bansi D

    2010-02-01

    Nanostructured polyaniline (PANI) film electrophoretically fabricated onto indium-tin-oxide (ITO) coated glass plate has been utilized for development of an immunosensor based on capacitance change of a parallel plate capacitor (PPC) by covalently immobilizing anti-human IgG (Anti-HIgG) using N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide chemistry. These fabricated PANI/ITO and Anti-HIgG/PANI/ITO plates have been characterized using scanning electron microscopy, cyclic voltammetry, differential pulse voltammetry and Fourier transform infra-red studies. The capacitance measurements indicate that dielectric medium of this biologically modified PPC (Anti-HIgG/PANI/ITO) is sensitive to HIgG in 5 - 5 x 10(5) ng mL(-1) range and has lower detection limit of 1.87 ng mL(-1). The observed results reveal that this Anti-HIgG modified PPC can be used as a robust, easy-to-use, reagentless, sensitive and selective immunosensor for estimation of human IgG.

  15. THERMAL DRIFT CHARACTERISTICS OF CAPACITIVE PRESSURE SENSORS

    Directory of Open Access Journals (Sweden)

    ABDELAZIZ BEDDIAF

    2016-03-01

    Full Text Available The capacitive pressure sensors based on silicon are characterized by their very high sensitivities and their low power consumption. Nevertheless, their thermal behavior remains more or less unpredictable because they can indicate very high thermal coefficients. The study of the thermal behavior of these sensors is essential to define the parameters that cause the output characteristics drift. In this study, we modeled the thermal behavior of this sensors, using Finite Element Analysis (FEA made in COMSOL. The model solved by COMSOL environment takes into account the entire sensor and thermal effects due to the temperature considering the materials’ properties, the geometric shape and also the heat transfer mechanisms. By COMSOL we determine how the temperature affects the sensor during the manufacturing process. For that end, we calculated the thermal drift of capacitance at rest, the thermal coefficients and we compared them with experimental results to validate our model. Further, we studied the thermal drift of sensor characteristics both at rest and under constant and uniform pressure. Further, our study put emphasis on the geometric influence parameters on these characteristics to optimize the sensor performance. Finally, this study allows us to predict the sensor behavior against temperature and to minimize this effect by optimizing the geometrical parameters.

  16. MR diffusion imaging and 1H spectroscopy in a child with medulloblastoma: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Wilke, M. [Max-Planck-Institute of Psychiatry, Muenchen (Germany). NMR Study Group; Eidenschink, A.; Mueller-Weihrich, S. [Technical Univ. of Muenchen, (Germany). Childrens' Hospital; Auer, D.P. [Max-Planck-Institute of Psychiatry, Muenchen (Germany). NMR Study Group

    2000-01-01

    We report on a child with a metastasising medulloblastoma which was assessed by MR diffusion imaging and 1H MR spectroscopy (MRS). Reduced mean apparent diffusion coefficients and a high amount of taurine could be demonstrated. This is the first reported case of high taurine in medulloblastoma in vivo and confirms earlier in vitro findings. It is suggested that the changes on diffusion imaging, possibly reflecting the small-cell histology of the tumour and high taurine in MRS, are indicative of medulloblastoma.

  17. Imaging of Primary Liver Carcinosarcoma Scintigraphically; A Case Report

    Science.gov (United States)

    Abdulrezzak, Ümmühan; Kula, Mustafa; Erdoğan, Zeynep; Tutuş, Ahmet

    2014-01-01

    Primary liver carcinosarcoma is a very rare disease. There have been only a few cases described to date, none of which has been imaged by bone scintigraphy. A 69-year-old man who developed right back pain and weight loss was admitted to our hospital. Tenderness of the right upper abdomen, hepatomegaly, and a giant mass were the main physical examination signs. Abdominal ultrasonography showed a large lobulated heterogeneous echogenic solid mass with multiple cystic areas of varying size and a highly echogenic region that had posterior acoustic shadowing within the mass in the right lobe of the liver. Labeled erythrocyte imaging and 99mTc-nanocolloid liver-spleen scan were performed to exclude hemangioma, showing a large intrahepatic photon deficient area. 99mTc-methylene diphosphonate (MDP) bone scintigraphy revealed heterogeneous, irregular and dense activity accumulation thought to be osteoblastic activity in the liver mass. Postsurgical pathological diagnosis revealed “carcinosarcoma”. Conflict of interest:None declared. PMID:24653934

  18. Evaluation of the contribution of radiological imaging to the final diagnosis in medical case reports

    Energy Technology Data Exchange (ETDEWEB)

    Wiesinger, Isabel; Scharf, Gregor; Platz, Natascha; Dendl, Lena M.; Stroszczynski, Christian; Schreyer, Andreas G. [University Hospital Regensburg, Institute of Radiology, Regensburg (Germany); Pawlik, Michael T. [Intensive Care and Emergency Medicine, Institute of Anaesthesiology, Regensburg (Germany)

    2015-05-01

    To evaluate the clinical value and impact of radiological imaging in published medial case reports. We analysed 671 consecutively published case reports of a peer-reviewed medical journal for case reports. The general use of radiological imaging as well as the specific imaging modality used in each case (ultrasound, x-ray, fluoroscopy, CT, MRI) was documented, and most importantly the 'final problem solver', i.e. the diagnostic modality giving the final clue to the patient's diagnosis, was identified. In 511 of 671 (76.1 %) analysed case reports at least one radiological modality was used in the diagnostic cascade. In 28.6 % of all cases the final diagnosis was achieved by radiological imaging. All other cases were solved by the patient's history and physical examination (15.2 %), histology (12.4 %), and blood analysis (9.6 %). When radiology was the 'final problem solver', it was mainly CT (51.6 %) and MRI (30.6 %). In 52.2 % of the case reports the radiological image was included in the article. In case reports published in a prominent general medical journal radiological imaging is an important key player in the diagnostic process. In many cases, it is also the diagnostic tool which ultimately leads to determining the final diagnosis. (orig.)

  19. Enhanced capacitive deionization of graphene/mesoporous carbon composites

    Science.gov (United States)

    Zhang, Dengsong; Wen, Xiaoru; Shi, Liyi; Yan, Tingting; Zhang, Jianping

    2012-08-01

    well retained and the composites display improved specific surface area and pore size distribution, as well as pore volume. Well dispersed GE nanosheets are deduced to be beneficial for enhanced electrical conductivity. The electrochemical performance of electrodes in an NaCl aqueous solution was characterized by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy measurements. The composite electrodes perform better on the capacitance values, conductive behaviour, rate performance and cyclic stability. The desalination capacity of the electrodes was evaluated by a batch mode electrosorptive experiment and the amount of adsorbed ions can reach 731 μg g-1 for the GE/MC composite electrode with a GE content of 5 wt%, which is much higher than that of MC alone (590 μg g-1). The enhanced CDI performance of the composite electrodes can be attributed to the better conductive behaviour and higher specific surface area. Electronic supplementary information (ESI) available: Experimental details. XRD patterns, TEM image and nitrogen adsorption-desorption isotherms of the samples. Cyclic voltammograms and galvanostatic charge-discharge curves of the GE/MC electrodes. See DOI: 10.1039/c2nr31154b

  20. Novel graphene-like electrodes for capacitive deionization.

    Science.gov (United States)

    Li, Haibo; Zou, Linda; Pan, Likun; Sun, Zhuo

    2010-11-15

    Capacitive deionization (CDI) is a novel technology that has been developed for removal of charged ionic species from salty water, such as salt ions. The basic concept of CDI, as well as electrosorption, is to force charged ions toward oppositely polarized electrodes through imposing a direct electric field to form a strong electrical double layer and hold the ions. Once the electric field disappears, the ions are instantly released back to the bulk solution. CDI is an alternative low-energy consumption desalination technology. Graphene-like nanoflakes (GNFs) with relatively high specific surface area have been prepared and used as electrodes for capacitive deionization. The GNFs were synthesized by a modified Hummers' method using hydrazine for reduction. They were characterized by atomic force microscopy, N2 adsorption at 77 K and electrochemical workstation. It was found that the ratio of nitric acid and sulfuric acid plays a vital role in determining the specific surface area of GNFs. Its electrosorption performance was much better than commercial activated carbon (AC), suggesting a great potential in capacitive deionisation application. Further, the electrosorptive performance of GNFs electrodes with different bias potentials, flow rates and ionic strengths were measured and the electrosorption isotherm and kinetics were investigated. The results showed that GNFs prepared by this process had the specific surface area of 222.01 m²/g. The specific electrosorptive capacity of the GNFs was 23.18 µmol/g for sodium ions (Na+) when the initial concentration was at 25 mg/L, which was higher than that of previously reported data using graphene and AC under the same experimental condition. In addition, the equilibrium electrosorption capacity was determined as 73.47 µmol/g at 2.0 V by fitting data through the Langmuir isotherm, and the rate constant was found to be 1.01 min⁻¹ by fitting data through pseudo first-order adsorption. The results suggested that the

  1. Scanning Capacitance Force Microscopy and Kelvin Probe Force Microscopy of Nanostructures Embedded in SiO2

    Science.gov (United States)

    Tallarida, G.; Spiga, S.; Fanciulli, M.

    Scanning capacitance force microscopy and Kelvin probe force microscopy are used to image Sn nanometer sized structures embedded in silicon oxide thin films. The capacitance variation occurring between probe and sample in presence of a metallic cluster modifies the oscillation amplitude of the AFM probe at twice the frequency of the applied voltage. The extreme localisation of the interaction due to the small geometries involved allows a lateral resolution of few nm. Issues related to the contrast mechanism and the spatial resolution are discussed with the support 2D finite element calculation of the electrostatic field distribution between probe and sample.

  2. "The Rush of Images": A Research Report into Digital Editing and the Moving Image.

    Science.gov (United States)

    Burn, Andrew; Brindley, Sue; Durran, James; Kelsall, Carol; Sweetlove, Jane; Tuohey, Caroline

    2001-01-01

    Describes an action research project on digital editing being carried out by a group of teachers. Evaluates a conceptual framework for editing digitized moving images, under three headings: literacies and communicative practices; creativity; and social roles and learning styles. Presents three teacher accounts of student projects involving digital…

  3. Imaging presentation of complicated diabetic ketoacidosis: a case report.

    Science.gov (United States)

    Escobar, Eduardo; Mullenix, Philip S; Sapp, Jason E

    2012-12-01

    Spontaneous pneumomediastinum is a fairly uncommon complication of diabetic ketoacidosis. Knowledge of the clinical and radiographic manifestation is important for the proper management of patients since the disease usually follows a benign evolution. We report a case of a 20-year-old soldier who presented with a pneumomediastinum that was initially falsely attributed to a motor vehicular crash.

  4. Exoplanet Community Report on Direct Infrared Imaging of Exoplanets

    Science.gov (United States)

    Danchi, William C.; Lawson, Peter R.

    2009-01-01

    Direct infrared imaging and spectroscopy of exoplanets will allow for detailed characterization of the atmospheric constituents of more than 200 nearby Earth-like planets, more than is possible with any other method under consideration. A flagship mission based on larger passively cooled infrared telescopes and formation flying technologies would have the highest angular resolution of any concept under consideration. The 2008 Exoplanet Forum committee on Direct Infrared Imaging of Exoplanets recommends: (1) a vigorous technology program including component development, integrated testbeds, and end-to-end modeling in the areas of formation flying and mid-infrared nulling; (2) a probe-scale mission based on a passively cooled structurally connected interferometer to be started within the next two to five years, for exoplanetary system characterization that is not accessible from the ground, and which would provide transformative science and lay the engineering groundwork for the flagship mission with formation flying elements. Such a mission would enable a complete exozodiacal dust survey (<1 solar system zodi) in the habitable zone of all nearby stars. This information will allow for a more efficient strategy of spectral characterization of Earth-sized planets for the flagship missions, and also will allow for optimization of the search strategy of an astrometric mission if such a mission were delayed due to cost or technology reasons. (3) Both the flagship and probe missions should be pursued with international partners if possible. Fruitful collaboration with international partners on mission concepts and relevant technology should be continued. (4) Research and Analysis (R&A) should be supported for the development of preliminary science and mission designs. Ongoing efforts to characterize the the typical level of exozodiacal light around Sun-like stars with ground-based nulling technology should be continued.

  5. Exoplanet Community Report on Direct Infrared Imaging of Exoplanets

    Science.gov (United States)

    Danchi, William C.; Lawson, Peter R.

    2009-01-01

    Direct infrared imaging and spectroscopy of exoplanets will allow for detailed characterization of the atmospheric constituents of more than 200 nearby Earth-like planets, more than is possible with any other method under consideration. A flagship mission based on larger passively cooled infrared telescopes and formation flying technologies would have the highest angular resolution of any concept under consideration. The 2008 Exoplanet Forum committee on Direct Infrared Imaging of Exoplanets recommends: (1) a vigorous technology program including component development, integrated testbeds, and end-to-end modeling in the areas of formation flying and mid-infrared nulling; (2) a probe-scale mission based on a passively cooled structurally connected interferometer to be started within the next two to five years, for exoplanetary system characterization that is not accessible from the ground, and which would provide transformative science and lay the engineering groundwork for the flagship mission with formation flying elements. Such a mission would enable a complete exozodiacal dust survey (<1 solar system zodi) in the habitable zone of all nearby stars. This information will allow for a more efficient strategy of spectral characterization of Earth-sized planets for the flagship missions, and also will allow for optimization of the search strategy of an astrometric mission if such a mission were delayed due to cost or technology reasons. (3) Both the flagship and probe missions should be pursued with international partners if possible. Fruitful collaboration with international partners on mission concepts and relevant technology should be continued. (4) Research and Analysis (R&A) should be supported for the development of preliminary science and mission designs. Ongoing efforts to characterize the the typical level of exozodiacal light around Sun-like stars with ground-based nulling technology should be continued.

  6. Breast Imaging in the Era of Big Data: Structured Reporting and Data Mining

    Science.gov (United States)

    Margolies, Laurie R.; Pandey, Gaurav; Horowitz, Eliot R.; Mendelson, David S.

    2016-01-01

    OBJECTIVE The purpose of this article is to describe structured reporting and the development of large databases for use in data mining in breast imaging. CONCLUSION The results of millions of breast imaging examinations are reported with structured tools based on the BI-RADS lexicon. Much of these data are stored in accessible media. Robust computing power creates great opportunity for data scientists and breast imagers to collaborate to improve breast cancer detection and optimize screening algorithms. Data mining can create knowledge, but the questions asked and their complexity require extremely powerful and agile databases. New data technologies can facilitate outcomes research and precision medicine. PMID:26587797

  7. Conductive two-dimensional titanium carbide `clay' with high volumetric capacitance

    Science.gov (United States)

    Ghidiu, Michael; Lukatskaya, Maria R.; Zhao, Meng-Qiang; Gogotsi, Yury; Barsoum, Michel W.

    2014-12-01

    Safe and powerful energy storage devices are becoming increasingly important. Charging times of seconds to minutes, with power densities exceeding those of batteries, can in principle be provided by electrochemical capacitors--in particular, pseudocapacitors. Recent research has focused mainly on improving the gravimetric performance of the electrodes of such systems, but for portable electronics and vehicles volume is at a premium. The best volumetric capacitances of carbon-based electrodes are around 300 farads per cubic centimetre; hydrated ruthenium oxide can reach capacitances of 1,000 to 1,500 farads per cubic centimetre with great cyclability, but only in thin films. Recently, electrodes made of two-dimensional titanium carbide (Ti3C2, a member of the `MXene' family), produced by etching aluminium from titanium aluminium carbide (Ti3AlC2, a `MAX' phase) in concentrated hydrofluoric acid, have been shown to have volumetric capacitances of over 300 farads per cubic centimetre. Here we report a method of producing this material using a solution of lithium fluoride and hydrochloric acid. The resulting hydrophilic material swells in volume when hydrated, and can be shaped like clay and dried into a highly conductive solid or rolled into films tens of micrometres thick. Additive-free films of this titanium carbide `clay' have volumetric capacitances of up to 900 farads per cubic centimetre, with excellent cyclability and rate performances. This capacitance is almost twice that of our previous report, and our synthetic method also offers a much faster route to film production as well as the avoidance of handling hazardous concentrated hydrofluoric acid.

  8. Conductive two-dimensional titanium carbide 'clay' with high volumetric capacitance.

    Science.gov (United States)

    Ghidiu, Michael; Lukatskaya, Maria R; Zhao, Meng-Qiang; Gogotsi, Yury; Barsoum, Michel W

    2014-12-04

    Safe and powerful energy storage devices are becoming increasingly important. Charging times of seconds to minutes, with power densities exceeding those of batteries, can in principle be provided by electrochemical capacitors--in particular, pseudocapacitors. Recent research has focused mainly on improving the gravimetric performance of the electrodes of such systems, but for portable electronics and vehicles volume is at a premium. The best volumetric capacitances of carbon-based electrodes are around 300 farads per cubic centimetre; hydrated ruthenium oxide can reach capacitances of 1,000 to 1,500 farads per cubic centimetre with great cyclability, but only in thin films. Recently, electrodes made of two-dimensional titanium carbide (Ti3C2, a member of the 'MXene' family), produced by etching aluminium from titanium aluminium carbide (Ti3AlC2, a 'MAX' phase) in concentrated hydrofluoric acid, have been shown to have volumetric capacitances of over 300 farads per cubic centimetre. Here we report a method of producing this material using a solution of lithium fluoride and hydrochloric acid. The resulting hydrophilic material swells in volume when hydrated, and can be shaped like clay and dried into a highly conductive solid or rolled into films tens of micrometres thick. Additive-free films of this titanium carbide 'clay' have volumetric capacitances of up to 900 farads per cubic centimetre, with excellent cyclability and rate performances. This capacitance is almost twice that of our previous report, and our synthetic method also offers a much faster route to film production as well as the avoidance of handling hazardous concentrated hydrofluoric acid.

  9. Electrical Capacitance Volume Tomography for the Packed Bed Reactor ISS Flight Experiment

    Science.gov (United States)

    Marashdeh, Qussai; Motil, Brian; Wang, Aining; Liang-Shih, Fan

    2013-01-01

    Fixed packed bed reactors are compact, require minimum power and maintenance to operate, and are highly reliable. These features make this technology a highly desirable unit operation for long duration life support systems in space. NASA is developing an ISS experiment to address this technology with particular focus on water reclamation and air revitalization. Earlier research and development efforts funded by NASA have resulted in two hydrodynamic models which require validation with appropriate instrumentation in an extended microgravity environment. To validate these models, the instantaneous distribution of the gas and liquid phases must be measured.Electrical Capacitance Volume Tomography (ECVT) is a non-invasive imaging technology recently developed for multi-phase flow applications. It is based on distributing flexible capacitance plates on the peripheral of a flow column and collecting real-time measurements of inter-electrode capacitances. Capacitance measurements here are directly related to dielectric constant distribution, a physical property that is also related to material distribution in the imaging domain. Reconstruction algorithms are employed to map volume images of dielectric distribution in the imaging domain, which is in turn related to phase distribution. ECVT is suitable for imaging interacting materials of different dielectric constants, typical in multi-phase flow systems. ECVT is being used extensively for measuring flow variables in various gas-liquid and gas-solid flow systems. Recent application of ECVT include flows in risers and exit regions of circulating fluidized beds, gas-liquid and gas-solid bubble columns, trickle beds, and slurry bubble columns. ECVT is also used to validate flow models and CFD simulations. The technology is uniquely qualified for imaging phase concentrations in packed bed reactors for the ISS flight experiments as it exhibits favorable features of compact size, low profile sensors, high imaging speed, and

  10. Negative capacitance in optically sensitive metal-insulator-semiconductor-metal structures

    Science.gov (United States)

    Mikhelashvili, V.; Padmanabhan, R.; Meyler, B.; Yofis, S.; Eisenstein, G.

    2016-12-01

    We report a strong negative capacitance effect in back to back combination of a metal-insulator-semiconductor (MIS) structure and a metal-semiconductor junction, which is fabricated on an n type Silicon-on-Insulator substrate. The MIS capacitor comprises a SiO2-HfO2 insulator stack with embedded Pt nanoparticles. The capacitor undergoes a voltage stress process and thereby turns into a varactor and a photodetector. The negative capacitance is observed only under illumination in structures that employ a Schottky back contact. A symmetric double or an asymmetric single negative capacitance peak is observed depending on the nature of illumination. The phenomenon is attributed to the modulation of the semiconductor conductance due to photo generated carriers and their incorporation in trapping/de-trapping processes on interfacial and post filamentation induced defects in the insulator stack. The frequency range of the observed effect is limited to 100 kHz. Large ratios of light to dark and maximum to minimum of negative capacitances as well as of the obtained sensitivity to the applied voltage are, respectively, 105, more than 100, and 10-15. These were measured at 10 kHz under illumination at 365 nm with a power of 2.5 × 10-6 W.

  11. Effects of multiple heteroatom species and topographic defects on electrocatalytic and capacitive performances of graphene

    Science.gov (United States)

    Fan, Mengmeng; Huang, Yang; Yuan, Fanshu; Hao, Qingli; Yang, Jiazhi; Sun, Dongping

    2017-10-01

    N-doped graphene has been widely researched as metal-free electrocatalyst and electrode material of energy storage devices but the effect of heteroatom species and topographic defects on these applications was rarely reported. We successfully prepared dual (N, S) or ternary heteroatoms (N, S, P)-doped graphene by simple hydrothermal and then carbonization treatment. Compared to singly N doping, multiple heteroatom species dopant is beneficial to positively move onset potential, approach four electron catalytic pathway in oxygen reduction reaction (ORR) due to the synergistic effect. The emerging topographic defects induced by removing heteroatoms and oxygen at high temperature also act as efficient active sites for positively shifting onset potential. Meanwhile, the porous ternary heteroatoms-doped graphene possesses a good capacitive performance such as high gravimetric capacitance (196.4 Fg-1 at 1 Ag-1), high retained rate (92.7%), 98% retention over 2000 recycling. The excellent capacitive properties derive from large specific surface area (943.5 m2 g-1), mesoporous structure, particularly the important role of abundant dopants of multiple heteroatom species. Therefore, we demonstrated the effect of heteroatom species and topographic defects on electrocatalyzing ORR and capacitive performance.

  12. Distributed Capacitance of Coaxial Line With Perturbed Walls

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Perturbation method of boundary geometry(PMOBG) used in Laplacian problems is dealt with and the three-term perturbation expression of distributed capacitance of a coaxial line with perturbed walls is obtained. As an example,four-order expression of distributed capacitance of a elliptic coaxial line with small eccentricity is given.

  13. Capacitance tuning of nanoscale split-ring resonators

    DEFF Research Database (Denmark)

    Jeppesen, Claus; Xiao, Sanshui; Mortensen, Niels Asger;

    2010-01-01

    In this paper, we investigate the capacitance tuning of nanoscale split-ring resonators. Based on a simple LC circuit model (LC-model), we derive an expression where the inductance is proportional to the area while the capacitance reflects the aspect ratio of the slit. The resonance frequency may...

  14. Capacitance tuning of nanoscale split-ring resonators

    DEFF Research Database (Denmark)

    Jeppesen, Claus; Mortensen, Asger; Kristensen, Anders

    2009-01-01

    We investigate the capacitance tuning of nanoscale split-ring resonators. Based on a simple inductor-capacitor circuit model, we derive an expression, where the inductance is proportional to the area while the capacitance reflects the aspect ratio of the slit. The resonance frequency may thus be ...

  15. 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 salin

  16. 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...

  17. 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.

  18. Capacitive bioanodes enable renewable energy storage in microbial fuel cells.

    Science.gov (United States)

    Deeke, Alexandra; Sleutels, Tom H J A; Hamelers, Hubertus V M; Buisman, Cees J N

    2012-03-20

    We developed an integrated system for storage of renewable electricity in a microbial fuel cell (MFC). The system contained a capacitive electrode that was inserted into the anodic compartment of an MFC to form a capacitive bioanode. This capacitive bioanode was compared with a noncapacitive bioanode on the basis of performance and storage capacity. The performance and storage capacity were investigated during polarization curves and charge-discharge experiments. During polarization curves the capacitive electrode reached a maximum current density of 1.02 ± 0.04 A/m(2), whereas the noncapacitive electrode reached a current density output of only 0.79 ± 0.03 A/m(2). During the charge-discharge experiment with 5 min of charging and 20 min of discharging, the capacitive electrode was able to store a total of 22,831 C/m(2), whereas the noncapacitive electrode was only able to store 12,195 C/m(2). Regarding the charge recovery of each electrode, the capacitive electrode was able to recover 52.9% more charge during each charge-discharge experiment compared with the noncapacitive electrode. The capacitive electrode outperformed the noncapacitive electrode throughout each charge-discharge experiment. With a capacitive electrode it is possible to use the MFC simultaneously for production and storage of renewable electricity.

  19. 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…

  20. Characterizing Inductive and Capacitive Nonlinear RLC Circuits : A Passivity Test

    NARCIS (Netherlands)

    García-Canseco, Eloísa; Jeltsema, Dimitri; Ortega, Romeo; Scherpen, Jacquelien M.A.

    2004-01-01

    Linear time-invariant RLC circuits are said to be inductive (capacitive) if the current waveform in sinusoidal steady-state has a negative (resp., positive) phase shift with respect to the voltage. Furthermore, it is known that the circuit is inductive (capacitive) if and only if the magnetic energy

  1. Non-invasive imaging using reporter genes altering cellular water permeability

    Science.gov (United States)

    Mukherjee, Arnab; Wu, Di; Davis, Hunter C.; Shapiro, Mikhail G.

    2016-12-01

    Non-invasive imaging of gene expression in live, optically opaque animals is important for multiple applications, including monitoring of genetic circuits and tracking of cell-based therapeutics. Magnetic resonance imaging (MRI) could enable such monitoring with high spatiotemporal resolution. However, existing MRI reporter genes based on metalloproteins or chemical exchange probes are limited by their reliance on metals or relatively low sensitivity. Here we introduce a new class of MRI reporters based on the human water channel aquaporin 1. We show that aquaporin overexpression produces contrast in diffusion-weighted MRI by increasing tissue water diffusivity without affecting viability. Low aquaporin levels or mixed populations comprising as few as 10% aquaporin-expressing cells are sufficient to produce MRI contrast. We characterize this new contrast mechanism through experiments and simulations, and demonstrate its utility in vivo by imaging gene expression in tumours. Our results establish an alternative class of sensitive, metal-free reporter genes for non-invasive imaging.

  2. New imaging probes to track cell fate: reporter genes in stem cell research.

    Science.gov (United States)

    Jurgielewicz, Piotr; Harmsen, Stefan; Wei, Elizabeth; Bachmann, Michael H; Ting, Richard; Aras, Omer

    2017-07-03

    Cell fate is a concept used to describe the differentiation and development of a cell in its organismal context over time. It is important in the field of regenerative medicine, where stem cell therapy holds much promise but is limited by our ability to assess its efficacy, which is mainly due to the inability to monitor what happens to the cells upon engraftment to the damaged tissue. Currently, several imaging modalities can be used to track cells in the clinical setting; however, they do not satisfy many of the criteria necessary to accurately assess several aspects of cell fate. In recent years, reporter genes have become a popular option for tracking transplanted cells, via various imaging modalities in small mammalian animal models. This review article examines the reporter gene strategies used in imaging modalities such as MRI, SPECT/PET, Optoacoustic and Bioluminescence Imaging. Strengths and limitations of the use of reporter genes in each modality are discussed.

  3. Hepatic adenomatosis: rapid sequence MR imaging following gadolinium enhancement: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Brummett, D. [Dept. of Radiology, Medical College of Georgia, Augusta (United States); Burton, E.M. [Dept. of Radiology, Medical College of Georgia, Augusta (United States)]|[Dept. of Pediatrics, Medical College of Georgia, Augusta (United States); Sabio, H. [Dept. of Pediatrics, Medical College of Georgia, Augusta (United States)

    1999-04-01

    Hepatic adenomas are primary liver tumors usually associated with underlying metabolic disease or with anabolic steroid or oral contraceptive use. Hepatic adenomatosis (HA) is defined as the presence of more than four adenomas. Only 13 cases of HA have been reported in patients without glycogen storage disease or steroid use. We report a case of HA imaged by postcontrast T1-weighted images obtained during a breath-holding series. The lesions were most conspicuous 3-4 min after contrast administration; 4 of the 5 tumors were not identified on T2-weighted images. Unlike previous reports of HA in which the lesions remained hyperintense during sequential postcontrast imaging, the smaller lesions in this case demonstrated contrast washout, thereby distinguishing them from hemangiomata. (orig.) With 3 figs., 10 refs.

  4. Rational Design of a Triple Reporter Gene for Multimodality Molecular Imaging

    Directory of Open Access Journals (Sweden)

    Ya-Ju Hsieh

    2014-01-01

    Full Text Available Multimodality imaging using noncytotoxic triple fusion (TF reporter genes is an important application for cell-based tracking, drug screening, and therapy. The firefly luciferase (fl, monomeric red fluorescence protein (mrfp, and truncated herpes simplex virus type 1 thymidine kinase SR39 mutant (ttksr39 were fused together to create TF reporter gene constructs with different order. The enzymatic activities of TF protein in vitro and in vivo were determined by luciferase reporter assay, H-FEAU cellular uptake experiment, bioluminescence imaging, and micropositron emission tomography (microPET. The TF construct expressed in H1299 cells possesses luciferase activity and red fluorescence. The tTKSR39 activity is preserved in TF protein and mediates high levels of H-FEAU accumulation and significant cell death from ganciclovir (GCV prodrug activation. In living animals, the luciferase and tTKSR39 activities of TF protein have also been successfully validated by multimodality imaging systems. The red fluorescence signal is relatively weak for in vivo imaging but may expedite FACS-based selection of TF reporter expressing cells. We have developed an optimized triple fusion reporter construct DsRedm-fl-ttksr39 for more effective and sensitive in vivo animal imaging using fluorescence, bioluminescence, and PET imaging modalities, which may facilitate different fields of biomedical research and applications.

  5. Effect of estrogens on boar sperm capacitation in vitro

    Directory of Open Access Journals (Sweden)

    Ded Lukas

    2010-07-01

    Full Text Available Abstract Background Mammalian sperm must undergo a series of controlled molecular processes in the female reproductive tract called capacitation before they are capable of penetrating and fertilizing the egg. Capacitation, as a complex biological process, is influenced by many molecular factors, among which steroidal hormone estrogens play their role. Estrogens, present in a high concentration in the female reproductive tract are generally considered as primarily female hormones. However, there is increasing evidence of their important impact on male reproductive parameters. The purpose of this study is to investigate the effect of three natural estrogens such as estrone (E1, 17beta-estradiol (E2 and estriol (E3 as well as the synthetical one, 17alpha-ethynylestradiol (EE2 on boar sperm capacitation in vitro. Methods Boar sperm were capacitated in vitro in presence of estrogens. Capacitation progress in control and experimental samples was analyzed by flow cytometry with the anti-acrosin monoclonal antibody (ACR.2 at selected times of incubation. Sperm samples were analyzed at 120 min of capacitation by CTC (chlortetracycline assay, immunocytochemistry and flow cytometry with anti-acrosin ACR.2 antibody. Furthermore, sperm samples and capacitating media were analyzed by immunocytochemistry, ELISA with the ACR.2 antibody, and the acrosin activity assay after induced acrosomal reaction (AR. Results Estrogens stimulate sperm capacitation of boar sperm collected from different individuals. The stimulatory effect depends on capacitation time and is highly influenced by differences in the response to estrogens such as E2 by individual animals. Individual estrogens have relatively same effect on capacitation progress. In the boar samples with high estrogen responsiveness, estrogens stimulate the capacitation progress in a concentration-dependent manner. Furthermore, estrogens significantly increase the number of acrosome-reacted sperm after zona

  6. Study of High Capacitance Ratios CPW MEMS Shunt Switches

    Institute of Scientific and Technical Information of China (English)

    Jianhai Sun; Dafu Cui

    2006-01-01

    This paper describes a fixed-fixed beam ohmic switch in series with a fixed capacitor as a replacement for a capacitive switch. In this switch, a metal plate deposited on the dielectric ensures perfectly contact with the dielectric layer in the down state. The area size of the metal plate directly influences the capacitance ratio of the switch, as the area size of the metal cap decreases, the capacitance ratio dramatically rises up. The down/up capacitance ratio can exceed 800 times over the conventional designs using the same materials and the equal size. Measurement results show that high capacitance ratio of the switches has a large effect on the isolation, and can actually improve the performance of the switches.

  7. Study of CMOS integrated signal processing circuit in capacitive sensors

    Institute of Scientific and Technical Information of China (English)

    CAO Yi-jiang; YU Xiang; WANG Lei

    2007-01-01

    A CMOS integrated signal processing circuit based on capacitance resonance principle whose structure is simple in capacitive sensors is designed. The waveform of output voltage is improved by choosing bootstrap reference current mirror with initiate circuit, CMOS analogy switch and positive feedback of double-stage inverter in the circuit. Output voltage of this circuit is a symmetric square wave signal. The variation of sensitive capacitance, which is part of the capacitive sensors, can be denoted by the change of output voltage's frequency. The whole circuit is designed with 1.5 μm P-well CMOS process and simulated by PSpice software.Output frequency varies from 261.05 kHz to 47.93 kHz if capacitance varies in the range of 1PF~15PF. And the variation of frequency can be easily detected using counter or SCU.

  8. Nonlinear Dynamics of Capacitive Charging and Desalination by Porous Electrodes

    CERN Document Server

    Biesheuvel, P M

    2009-01-01

    The rapid and efficient exchange of ions between porous electrodes and aqueous solutions is important in many applications, such as electrical energy storage by super-capacitors, water desalination and purification by capacitive deionization (or desalination), 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) in the limit of thin double layers (compared to typical pore dimensions). We illustrate the theory in 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 wi...

  9. Engineering Dark Chromoprotein Reporters for Photoacoustic Microscopy and FRET Imaging

    Science.gov (United States)

    Li, Yan; Forbrich, Alex; Wu, Jiahui; Shao, Peng; Campbell, Robert E.; Zemp, Roger

    2016-03-01

    A subset of the family of fluorescent proteins are the non-fluorescent chromoproteins which are promising probe molecules for use in photoacoustic imaging and as acceptor chromophores in Förster resonance energy transfer (FRET)-based biosensors. Typical approaches for fluorescent protein optimization by screening of large libraries of variants cannot be effectively applied to chromoproteins due to their characteristic lack of fluorescence. To address this challenge, we have developed a directed evolution method to iteratively screen large libraries of protein variants on the basis of their photoacoustic signal levels. By applying this procedure to the promising Ultramarine and cjBlue chromoprotein templates, we were able to identify improved variants with a 02-04 fold increase in photoacoustic signal-to-noise ratio after only a few evolutionary steps. These improved variants enable more accurate spectral de-mixing and localization of protein-producing bacteria in vivo and serve as effective FRET acceptors for both fluorescence- and photoacoustic-based detection of protease activity.

  10. The ESO Imaging Survey Status Report and Preliminary Results

    CERN Document Server

    Da Costa, L N; Deul, E; Erben, T; Freudling, W; Guarnieri, M D; Hook, I; Hook, R N; Méndez, R; Nonino, M; Olsen, L; Prandoni, I; Renzini, A; Savaglio, S; Scodeggio, M; Silva, D; Slijkhuis, R; Wicenec, A; Wichmann, R; Benoist, C

    1998-01-01

    The ESO Imaging Survey (EIS) presented in early issues of the Messenger, and with up-to-date information on the ongoing observations available on the Web (http://www.eso.org/eis), is a concerted effort by ESO and the Member State community to provide targets for the first year of operation of the VLT. It consists of two parts: a relatively wide-angle survey (EIS-WIDE) to cover four pre-selected patches of sky, 6 square degrees each, spread in right ascension to search for distant clusters and quasars and a deep, multicolor survey of four optical (SUSI-2) and two infrared (SOFI) covering the HST/Hubble Deep Field South (HDFS) and its flanking fields (EIS-DEEP). From the start, the main challenge has been to carry out a public survey in a limited amount of time requiring observations, software development and data reduction with the goal of distributing the survey data products before the call for proposal for the VLT. To cope with this one-year timetable, a novel type of collaboration between ESO and the commu...

  11. Creatinine Diffusion Modeling in Capacitive Sensors

    Science.gov (United States)

    Mohabbati-Kalejahi, Elham; Azimirad, Vahid; Bahrami, Manouchehr

    2016-12-01

    In this paper, creatinine diffusion in capacitive sensors is discussed. The factors influencing the response time of creatinine biosensors are mathematically formulated and then three novel approaches for decreasing the response time are presented. At first, a piezoelectric actuator is used to vibrate the microtube that contains the blood sample, in order to reduce the viscosity of blood, and thus to increase the coefficient of diffusion. Then, the blood sample is assumed to be pushed through a porous medium, and the relevant conditions are investigated. Finally, the effect of the dentate shape of dielectric on response time is studied. The algorithms and the mathematical models are presented and discussed, and the results of simulations are illustrated. The response times for the first, second and third method are 60, 0.036 and about 31 s, respectively. It is also found that pumping results in very fast responses.

  12. Fund allocation using capacitated vehicle routing problem

    Science.gov (United States)

    Mamat, Nur Jumaadzan Zaleha; Jaaman, Saiful Hafizah; Ahmad, Rokiah Rozita; Darus, Maslina

    2014-09-01

    In investment fund allocation, it is unwise for an investor to distribute his fund into several assets simultaneously due to economic reasons. One solution is to allocate the fund into a particular asset at a time in a sequence that will either maximize returns or minimize risks depending on the investor's objective. The vehicle routing problem (VRP) provides an avenue to this issue. VRP answers the question on how to efficiently use the available fleet of vehicles to meet a given service demand, subjected to a set of operational requirements. This paper proposes an idea of using capacitated vehicle routing problem (CVRP) to optimize investment fund allocation by employing data of selected stocks in the FTSE Bursa Malaysia. Results suggest that CRVP can be applied to solve the issue of investment fund allocation and increase the investor's profit.

  13. Capacitated dynamic lot sizing with capacity acquisition

    DEFF Research Database (Denmark)

    Li, Hongyan; Meissner, Joern

    2011-01-01

    batch, along with inventory carrying costs. The production per period is limited by a capacity restriction. The underlying capacity must be purchased up front for the upcoming season and remains constant over the entire season. We assume that the capacity acquisition cost is smooth and convex......One of the fundamental problems in operations management is determining the optimal investment in capacity. Capacity investment consumes resources and the decision, once made, is often irreversible. Moreover, the available capacity level affects the action space for production and inventory...... planning decisions directly. In this article, we address the joint capacitated lot-sizing and capacity-acquisition problems. The firm can produce goods in each of the finite periods into which the production season is partitioned. Fixed as well as variable production costs are incurred for each production...

  14. [Wireless ECG measurement system with capacitive coupling].

    Science.gov (United States)

    Aleksandrowicz, Adrian; Walter, Marian; Leonhardt, Steffen

    2007-04-01

    This paper describes a measurement system that captures an electrocardiogram (ECG) using capacitively coupled electrodes. The measurement system was integrated into an off-the-shelf office chair (so-called "Aachen SmartChair"). Whereas for classical ECG measurement adhesive is used to attach conductively coupled electrodes to bare skin, the system presented allows ECG measurement through clothing without direct skin contact. Furthermore, a ZigBee communication module was integrated to allow wireless transmission of ECG data to a PC or an ICU patient monitor. For system validation, classical ECG using conductive electrodes was obtained simultaneously. First measurement results, including variations of cloth thickness and material, are presented and some of the system-specific problems of this approach are discussed.

  15. MOS Capacitance-Voltage Characteristics Ⅲ.Trapping Capacitance from 2-Charge-State Impurities

    Institute of Scientific and Technical Information of China (English)

    Jie Binbin; Sah Chihtang

    2011-01-01

    Low-frequency and high-frequency capacitance-voltage curves of Metal-Oxide-Semiconductor Capacitors are presented to illustrate giant electron and hole trapping capacitances at many simultaneously present two-charge-state and one-trapped-carrier,or one-energy-level impurity species.Models described include a donor electron trap and an acceptor hole trap,both donors,both acceptors,both shallow energy levels,both deep,one shallow and one deep,and the identical donor and acceptor.Device and material parameters are selected to simulate chemically and physically realizable capacitors for fundamental trapping parameter characterizations and for electrical and optical signal processing applications.

  16. MR imaging and ultrasonographic findings of tensor fasciae suralis muscle: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Keun Ho; Shim, Jae Chan; Lee, Ghi Jai; Lee, Kyoung Eun; Kim, Ho Kyun; Suh, Jung Ho [Dept. of Radiology, Seoul Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of)

    2015-10-15

    The tensor fasciae suralis muscle is a very rare anomalous muscle located in the popliteal region. This anatomic variation has been reported often through cadaver studies. However, there are only a few radiologic reports of this entity. We presented a case of tensor fasciae suralis muscle detected as an incidental finding in magnetic resonance imaging and ultrasound.

  17. Imaging findings of perirenal epithelioid angiomyolipoma mimicking a malignant retroperitoneal tumor: A case report with imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Youn; Woo, Ji Young; Shin, Mi Kyoung; Lee, Yul; Hwang, Ji Young; Kim, Hee Yeong [Hallym University College of Medicine, Kangnam Sacred Heart Hospital, Seoul (Korea, Republic of); Park, Sung Bae [Dept. of Surgery, Kangwon National University Hospital, Chuncheon (Korea, Republic of)

    2016-09-15

    Epithelioid angiomyolipoma (EAML) is an uncommon, variant type of angiomyolipoma with a possibility of metastatic transformation and distant spread. Angiomyolipomas, including epithelioid variant type, are mostly renal in origin. EAML originating from extrarenal location is very rare and imaging findings are not well described. Herein, we reported a very rare case of EAML arising from the perirenal space that mimicked a malignant retroperitoneal tumor, in a 39-year-old female.

  18. Geophysical data fusion for subsurface imaging. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    This report contains the results of a three year, three-phase project whose long-range goal has been to create a means for the more detailed and accurate definition of the near-surface (0--300 ft) geology beneath a site that had been subjected to environmental pollution. The two major areas of research and development have been: improved geophysical field data acquisition techniques; and analytical tools for providing the total integration (fusion) of all site data. The long-range goal of this project has been to mathematically, integrate the geophysical data that could be derived from multiple sensors with site geologic information and any other type of available site data, to provide a detailed characterization of thin clay layers and geological discontinuities at hazardous waste sites.

  19. Expression, cellular localization, and involvement of the pentose phosphate pathway enzymes in the regulation of ram sperm capacitation.

    Science.gov (United States)

    Luna, C; Serrano, E; Domingo, J; Casao, A; Pérez-Pé, R; Cebrián-Pérez, J A; Muiño-Blanco, T

    2016-08-01

    Spermatozoa require substantially more ATP than other cells, not only for sustaining sperm motility but also for regulating protein phosphorylation during capacitation. In this study, we have reported for the first time the presence of the two key enzymes of the pentose phosphate pathway (PPP), glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase in ovine spermatozoa by indirect immunofluorescence, Western blotting, in-gel activity, and reverse transcription polymerase chain reaction analysis. We found that the activity of both enzymes significantly increased after in vitro capacitation in the presence of high-cAMP levels, with a concomitant increase in protein tyrosine phosphorylation and in the proportion of sperm-capacitated pattern assessed by the chlortetracycline staining. These results suggest that PPP is related with the progress of capacitation and that a relationship between calcium compartmentalization, protein tyrosine phosphorylation and PPP seems to exist. This is the first report that shows a connection between the PPP, cAMP/PKA signaling pathways and sperm capacitation. These findings can be of high-biological importance to improve our knowledge of the biochemical mechanisms involved in the acquisition of mammalian sperm functional competence and, ultimately, fertility.

  20. Multimodality imaging of bilateral pheochromocytoma. A case report.

    Science.gov (United States)

    Paladino, Nunzia Cinzia; Lowery, Aoife; Guérin, Carole; Taïeb, David; Sebag, Frédéric

    2015-06-22

    . La TEP alla 18 FDG, grazie all’uso della metodica qualitativa e quantitativa nell’analisi della lesione, è stata molto utile nello svelarne la natura. Veniva pertanto eseguita una surrenalectomia sinistra per via laparoscopica. L’esame istologico per entrambe le lesioni era in favore di feocromocitoma, Pass score 0. Nella fase post-operatoria la paziente veniva trattata con idrocortisone a dosi decrescenti fino ad un dosaggio giornaliero di 30 mg in associazione a 50 mg di fludrocortisone. Questo caso clinico dimostra ancora una volta la possibilità di falsi negativi da parte di tecniche di imaging funzionale specifiche. In questa esperienza, la TEP alla 18 FDG è stata molto utile. La RMN ha senza dubbio mostrato un valore incontestabile. In questa paziente non è stata trovata nessuna mutazione germinale a carico dei geni RET, VHL, SDHx.

  1. Ambient-processable high capacitance hafnia-organic self-assembled nanodielectrics.

    Science.gov (United States)

    Everaerts, Ken; Emery, Jonathan D; Jariwala, Deep; Karmel, Hunter J; Sangwan, Vinod K; Prabhumirashi, Pradyumna L; Geier, Michael L; McMorrow, Julian J; Bedzyk, Michael J; Facchetti, Antonio; Hersam, Mark C; Marks, Tobin J

    2013-06-19

    Ambient and solution-processable, low-leakage, high capacitance gate dielectrics are of great interest for advances in low-cost, flexible, thin-film transistor circuitry. Here we report a new hafnium oxide-organic self-assembled nanodielectric (Hf-SAND) material consisting of regular, alternating π-electron layers of 4-[[4-[bis(2-hydroxyethyl)amino]phenyl]diazenyl]-1-[4-(diethoxyphosphoryl) benzyl]pyridinium bromide) (PAE) and HfO2 nanolayers. These Hf-SAND multilayers are grown from solution in ambient with processing temperatures ≤150 °C and are characterized by AFM, XPS, X-ray reflectivity (2.3 nm repeat spacing), X-ray fluorescence, cross-sectional TEM, and capacitance measurements. The latter yield the largest capacitance to date (1.1 μF/cm(2)) for a solid-state solution-processed hybrid inorganic-organic gate dielectric, with effective oxide thickness values as low as 3.1 nm and have gate leakage 0.2 mm(2)) on Hf-SAND (6.5 nm thick) achieve mA on currents at ultralow gate voltages (nanodielectric. High-temperature annealing in ambient (400 °C) has limited impact on Hf-SAND leakage densities (<10(-6) A/cm(2) at ±2 V) and enhances Hf-SAND multilayer capacitance densities to nearly 1 μF/cm(2), demonstrating excellent compatibility with device postprocessing methodologies. These results represent a significant advance in hybrid organic-inorganic dielectric materials and suggest synthetic routes to even higher capacitance materials useful for unconventional electronics.

  2. Flexible Fiber-Optic High-Speed Imaging of Vocal Fold Vibration: A Preliminary Report.

    Science.gov (United States)

    Woo, Peak; Baxter, Peter

    2017-03-01

    High-speed video (HSV) imaging of vocal fold vibration has been possible only through the rigid endoscope. This study reports that a fiberscope-based high-speed imaging system may allow HSV imaging of naturalistic voicing. Twenty-two subjects were recorded using a commercially available black and white high-speed camera (Photron Motion Tools, 256 × 120 pixel, 2000 frames per second, 8 second acquisition time). The camera gain is set to +6 db. The camera is coupled to a standard fiber-optic laryngoscope (Olympus ENF P-4) with a 300-W Xenon light. Image acquisition was done by asking the subject to perform repeated phonation at modal phonation. Video images were processed using commercial video editing and video noise reduction software (After effects, Magix, and Neat Video 4.1). After video processing, the video images were analyzed using digital kymography (DKG). The HSV black and white video acquired by the camera is gray and lacks contrast. By adjustment of image contrast, brightness, and gamma and using noise reduction software, the flexible laryngoscopy image can be converted to video image files suitable for DKG and waveform analysis. The increased noise still makes edge tracking for objective analysis difficult, but subjective analysis of DKG plot is possible. This is the first report of HSV acquisition in an unsedated patient using a fiberscope. Image enhancement and noise reduction can enhance the HSV to allow extraction of the digital kymogram. Further image enhancement may allow for objective analysis of the vibratory waveform. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  3. NCRP report 160 and what it means for medical imaging and nuclear medicine.

    Science.gov (United States)

    Bolus, Norman E

    2013-12-01

    The purpose of this paper is to briefly explain report 160 of the National Council on Radiation Protection and Measurement and the significance of the report to medical imaging as a whole and nuclear medicine specifically. The implications of the findings of report 160 have had repercussions and will continue to affect all of ionizing radiation medical imaging. The nuclear medicine community should have an understanding of why and how report 160 is important. After reading this article, the nuclear medicine technologist will be familiar with the main focus of report 160, the significant change that has occurred since the 1980s in the ionizing radiation exposure of people in the United States, the primary background source of ionizing radiation in the United States, the primary medical exposure to ionizing radiation in the United States, trends in nuclear medicine procedures and patient exposure, and a comparison of population doses between 2006 and the early 1980s as outlined in report 160.

  4. EFFECT OF AMBIENT AIR CONDITIONS ON LOW FREQUENCY NEGATIVE CAPACITANCE OF NC-TIO2/P3HT HETEROJUNCTION SOLAR CELLS

    Directory of Open Access Journals (Sweden)

    H. Al-Dmour

    2014-01-01

    Full Text Available We report the negative capacitance of nanocrystalline titanium dioxide/poly (3-hexyl thiophene, nc-TiO2/P3HT, heterojunction solar cells. In air, a low frequency negative capacitance has been observed under forward bias condition associated with high values of conductance. Interestingly, the negative capacitance disappear when the device is placed in vacuum chamber. These results are attributed to affect the ambient condition on the charge carrier concentration in materials used to fabricated solar cells and increase bulk region resistance.

  5. Chordoid glioma with intraventricular dissemination: A case report with perfusion MR imaging features

    Energy Technology Data Exchange (ETDEWEB)

    Ki, So Yeon; Kim, Seul Kee; Heo, Tae Wook; Baek, Byung Hyun; Kim, Hyung Seok; Yoon, Woong [Chonnam National University Medical School, Chonnam National University Hospital, Gwangju (Korea, Republic of)

    2016-02-15

    Chordoid glioma is a rare low grade tumor typically located in the third ventricle. Although a chordoid glioma can arise from ventricle with tumor cells having features of ependymal differentiation, intraventricular dissemination has not been reported. Here we report a case of a patient with third ventricular chordoid glioma and intraventricular dissemination in the lateral and fourth ventricles. We described the perfusion MR imaging features of our case different from a previous report.

  6. Characterization of electrical and mechanical activities of rabbit uterus associated with the presence of capacitated and non-capacitated spermatozoa

    Directory of Open Access Journals (Sweden)

    J.F. Lazcano-Reyes

    2013-12-01

    Full Text Available To investigate the effects capacitated spermatozoa may exert upon motility of the rabbit uterus, both contractility and electrical activity (frequency and intensity were measured in 3 distinctive uterine segments of anaesthetized does: horn (UH, uterotubal junction (UTJ and tube (UT after 1 natural mating, 2 infusion of either seminal plasma or PBS, 3 infusion of either capacitated or non-capacitated spermatozoa. Basal values were: 17.1, 15.7, 16.4 g (contractility, P>0.05; 3.5, 3.5, 3.4 Hz (frequency, P>0.05; 0.49, 0.50, 0.57 μV (intensity, P>0.05 for UH, UTJ, UT, respectively. Seminal plasma caused an increase (P<0.05 in the UH contractility: 26.3 vs. 11.7 (natural mating and 17.0 g (PBS; it also caused a decrease (P<0.05 in electrical intensity at the UTJ: 0.24 vs. 0.67 (natural mating and 0.58 μV (PBS. The presence of either capacitated or non-capacitated spermatozoa caused no changes in contractility and electrical frequency in any of the uterine segments. However, there was a change in electrical intensity at UTJ (0.37 vs. 0.57 μV for non-capacitated and capacitated spermatozoa, respectively; P<0.05. There were also differences between segments by treatment: UTJ (0.37 vs. UT (0.59 μV for non-capacitated; UH (0.46 vs. UT (0.71 μV for capacitated spermatozoa (P<0.05. In conclusion, use of this experimental model showed that uterine electrical activity was slightly modified by the presence of capacitated spermatozoa.

  7. Improving knowledge management through the support of image examination and data annotation using DICOM structured reporting.

    Science.gov (United States)

    Torres, José Salavert; Damian Segrelles Quilis, J; Espert, Ignacio Blanquer; García, Vicente Hernandez

    2012-12-01

    An important effort has been invested on improving the image diagnosis process in different medical areas using information technologies. The field of medical imaging involves two main data types: medical imaging and reports. Developments based on the DICOM standard have demonstrated to be a convenient and widespread solution among the medical community. The main objective of this work is to design a Web application prototype that will be able to improve diagnosis and follow-on of breast cancer patients. It is based on TRENCADIS middleware, which provides a knowledge-oriented storage model composed by federated repositories of DICOM image studies and DICOM-SR medical reports. The full structure and contents of the diagnosis reports are used as metadata for indexing images. The TRENCADIS infrastructure takes full advantage of Grid technologies by deploying multi-resource grid services that enable multiple views (reports schemes) of the knowledge database. The paper presents a real deployment of such Web application prototype in the Dr. Peset Hospital providing radiologists with a tool to create, store and search diagnostic reports based on breast cancer explorations (mammography, magnetic resonance, ultrasound, pre-surgery biopsy and post-surgery biopsy), improving support for diagnostics decisions. A technical details for use cases (outlining enhanced multi-resource grid services communication and processing steps) and interactions between actors and the deployed prototype are described. As a result, information is more structured, the logic is clearer, network messages have been reduced and, in general, the system is more resistant to failures.

  8. Reporter gene imaging of targeted T cell immunotherapy in recurrent glioma.

    Science.gov (United States)

    Keu, Khun Visith; Witney, Timothy H; Yaghoubi, Shahriar; Rosenberg, Jarrett; Kurien, Anita; Magnusson, Rachel; Williams, John; Habte, Frezghi; Wagner, Jamie R; Forman, Stephen; Brown, Christine; Allen-Auerbach, Martin; Czernin, Johannes; Tang, Winson; Jensen, Michael C; Badie, Behnam; Gambhir, Sanjiv S

    2017-01-18

    High-grade gliomas are aggressive cancers that often become rapidly fatal. Immunotherapy using CD8(+) cytotoxic T lymphocytes (CTLs), engineered to express both herpes simplex virus type 1 thymidine kinase (HSV1-TK) and interleukin-13 (IL-13) zetakine chimeric antigen receptor (CAR), is a treatment strategy with considerable potential. To optimize this and related immunotherapies, it would be helpful to monitor CTL viability and trafficking to glioma cells. We show that noninvasive positron emission tomography (PET) imaging with 9-[4-[(18)F]fluoro-3-(hydroxymethyl)butyl]guanine ([(18)F]FHBG) can track HSV1-tk reporter gene expression present in CAR-engineered CTLs. [(18)F]FHBG imaging was safe and enabled the longitudinal imaging of T cells stably transfected with a PET reporter gene in patients. Further optimization of this imaging approach for monitoring in vivo cell trafficking should greatly benefit various cell-based therapies for cancer.

  9. Venous infraction of developmental venous anomaly: A case report with perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Youn; Kim, Hye Jeong; Hyun, Su Jeong; Kim, Hee Yeong; Kim, Han Myun; Hwang, Ji Young; Hong, Hye Suk; Woo, Ji Young; Yang, Ik [Dept. of Radiology, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul (Korea, Republic of); Kim, Eun Soo [Dept. of Radiology, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang (Korea, Republic of)

    2017-06-15

    Developmental venous anomaly (DVA) is a common congenital venous malformation characterized by dilated medullary veins in caput medusa configuration and a draining vein. Despite the high incidence of DVAs, they are benign anatomic variations and rarely cause symptoms. Here, we report computed tomography and magnetic resonance imaging findings with perfusion images of acute infarction from underlying DVA in a 63-year-old female patient who presented with acute onset of neurologic symptoms and recovered without any neurologic deficit.

  10. Acceptance test report for the Tank 241-C-106 in-tank imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, L.T.

    1998-05-22

    This document presents the results of Acceptance Testing of the 241-C-106 in-tank video camera imaging system. The purpose of this imaging system is to monitor the Project W-320 sluicing of Tank 241-C-106. The objective of acceptance testing of the 241-C-106 video camera system was to verify that all equipment and components function in accordance with procurement specification requirements and original equipment manufacturer`s (OEM) specifications. This document reports the results of the testing.

  11. Validating tyrosinase homologue melA as a photoacoustic reporter gene for imaging Escherichia coli

    Science.gov (United States)

    Paproski, Robert J.; Li, Yan; Barber, Quinn; Lewis, John D.; Campbell, Robert E.; Zemp, Roger

    2015-10-01

    To understand the pathogenic processes for infectious bacteria, appropriate research tools are required for replicating and characterizing infections. Fluorescence and bioluminescence imaging have primarily been used to image infections in animal models, but optical scattering in tissue significantly limits imaging depth and resolution. Photoacoustic imaging, which has improved depth-to-resolution ratio compared to conventional optical imaging, could be useful for visualizing melA-expressing bacteria since melA is a bacterial tyrosinase homologue which produces melanin. Escherichia coli-expressing melA was visibly dark in liquid culture. When melA-expressing bacteria in tubes were imaged with a VisualSonics Vevo LAZR system, the signal-to-noise ratio of a 9× dilution sample was 55, suggesting that ˜20 bacteria cells could be detected with our system. Multispectral (680, 700, 750, 800, 850, and 900 nm) analysis of the photoacoustic signal allowed unmixing of melA-expressing bacteria from blood. To compare photoacoustic reporter gene melA (using Vevo system) with luminescent and fluorescent reporter gene Nano-lantern (using Bruker Xtreme In-Vivo system), tubes of bacteria expressing melA or Nano-lantern were submerged 10 mm in 1% Intralipid, spaced between bioluminescence and fluorescence imaging could not resolve the two tubes of Nano-lantern-expressing bacteria even when the tubes were spaced 10 mm from each other. After injecting 100-μL of melA-expressing bacteria in the back flank of a chicken embryo, photoacoustic imaging allowed visualization of melA-expressing bacteria up to 10-mm deep into the embryo. Photoacoustic signal from melA could also be separated from deoxy- and oxy-hemoglobin signal observed within the embryo and chorioallantoic membrane. Our results suggest that melA is a useful photoacoustic reporter gene for visualizing bacteria, and further work incorporating photoacoustic reporters into infectious bacterial strains is warranted.

  12. Data from: Dispenser printed capacitive proximity sensor on fabric for applications in the creative industries

    OpenAIRE

    2016-01-01

    This paper reports a planar capacitive proximity sensor fully dispenser printed on a standard polyester woven fabric using conductive ink. Dispenser printing is a new digital printing technique offering the advantages of complete geometric design flexibility and the ability to direct write multilayer devices without requiring bespoke tooling. A dispenser printer is also capable of printing a wide range of ink viscosities encompassing those of inkjet and screen printable inks. Previous researc...

  13. Dispenser printed capacitive proximity sensor on fabric for applications in the creative industries

    OpenAIRE

    2016-01-01

    This paper reports a planar capacitive proximity sensor fully dispenser printed on a standard polyester woven fabric using conductive ink. Dispenser printing is a new digital printing technique offering the advantages of complete geometric design flexibility and the ability to direct write multilayer devices without requiring bespoke tooling. A dispenser printer is also capable of printing a wide range of ink viscosities encompassing those of inkjet and screen printable inks. Previous researc...

  14. Breast imaging and reporting data system (BIRADS) magnetic resonance imaging illustrated cases.

    Science.gov (United States)

    Tardivon, Anne A; Athanasiou, Alexandra; Thibault, Fabienne; El Khoury, Carl

    2007-02-01

    Illustrated cases are presented here, for training the reader to BIRADS MRI. This article offers guidance in integrating findings from the different MR sequences, morphology and kinetics of an abnormal enhancement: report organization, use of lexicon for describing the detected lesion, final assessment with BI-RADS assessment categories.

  15. Breast imaging and reporting data system (BIRADS) magnetic resonance imaging illustrated cases

    Energy Technology Data Exchange (ETDEWEB)

    Tardivon, Anne A. [Department of Radiology, Institut CURIE, 26 rue d' Ulm, 75248 Paris Cedex 05 (France)]. E-mail: anne.tardivon@curie.net; Athanasiou, Alexandra [Department of Radiology, Institut CURIE, 26 rue d' Ulm, 75248 Paris Cedex 05 (France); Thibault, Fabienne [Department of Radiology, Institut CURIE, 26 rue d' Ulm, 75248 Paris Cedex 05 (France); El Khoury, Carl [Department of Radiology, Institut CURIE, 26 rue d' Ulm, 75248 Paris Cedex 05 (France)

    2007-02-15

    Illustrated cases are presented here, for training the reader to BIRADS MRI. This article offers guidance in integrating findings from the different MR sequences, morphology and kinetics of an abnormal enhancement: report organization, use of lexicon for describing the detected lesion, final assessment with BI-RADS assessment categories.

  16. Computed Tomography and Magnetic Resonance Imaging of Myoepitheliloma in the Soft Palate: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Hun Cheol; Yu, In Kyu [Dept. of Radiology, Eulji University Hospital, Daejeon (Korea, Republic of); Park, Mi Ja [Dept. of Pathology, Eulji University Hospital, Daejeon (Korea, Republic of); Jang, Dong Sik [Dept. of Otorthinolaryngology, Eulji University Hospital, Daejeon (Korea, Republic of)

    2011-07-15

    We report the appearance of myoepithelioma arising from minor salivary glands in the soft palate observed on computed tomography (CT) and magnetic resonance imaging (MRI). CT, the tumor was round with a smooth and partial lobulating contour, and slightly marginal contrast enhancement. On T1-weighted images, the mass had heterogeneous iso-signal intensity compared to the pharyngeal muscle. Additionally, the tumor had heterogeneously high T2 signal intensity with heterogeneously strong enhancement on the Gd-enhanced T1-weighted image. Radiologists should consider myoepithelioma in the radiological differential diagnosis of soft palate tumors.

  17. Novel diffusion-weighted magnetic resonance imaging findings in leptomeningeal carcinomatosis: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Y.F.; Chang, F.C.; Hu, H.H.; Hsu, L.C. [Taipei Veterans General Hospital, Taiwan (China). Depts. of Internal Medicine and Radiology, and Neurological Inst.

    2006-12-15

    This report presents a rare case of leptomeningeal carcinomatosis initially presenting with mental impairment and rapidly progressing to coma without any history of malignancy. In addition to highlighting the diagnostic difficulties, the linear high signal intensity along the cortex on the diffusion-weighted imaging (DWI) sequence of magnetic resonance (MR) imaging was identified accidentally. High signal change in the corresponding areas was also noted on unenhanced fluid-attenuated inversion recovery (FLAIR) MR imaging, which may be a novel method of diagnosing leptomeningeal carcinomatosis, which should be studied further.

  18. Magnetic resonance imaging findings in primary lymphoma of the liver: a case report

    Directory of Open Access Journals (Sweden)

    Bilaj Fatmir

    2012-09-01

    Full Text Available Abstract Introduction Primary lymphoma of the liver is an extremely rare finding, with the few such cases reported in the literature to date describing indeterminate imaging findings, being focused more on computed tomography. To the best of our knowledge, there is no prior report describing magnetic resonance imaging scan findings with such a lesion. In the case reported here, magnetic resonance imaging gave us the opportunity to ascertain the correct diagnosis, confirmed by histopathology, thus avoiding unnecessary surgery or other treatments. Although this condition is rare, knowledge of magnetic resonance imaging findings will be invaluable for radiologists and other medical subspecialties that may face such cases in the future in helping to provide adequate management for affected patients. Case presentation A focal lesion was incidentally detected by ultrasound in a 75-year-old asymptomatic Albanian man being treated for benign hypertrophy of prostate. Chest and abdomen computed tomography scans did not reveal any abnormal findings besides a solid focal lesion on the right lobe of the liver and a mild homogenous enlargement of the prostate gland. Subsequently, magnetic resonance imaging of the upper abdomen was performed for better characterization of this lesion. Our patient was free of symptoms and his laboratory test results were normal. Conclusions The magnetic resonance imaging scan results showed some distinctive features that helped us to make the correct diagnosis, and were thus very important in helping us provide the correct treatment for our patient.

  19. Pleomorphic adenoma: Choice of radiographic imaging modality - Computed tomography or magnetic resonance imaging? Illustration through a case report

    Directory of Open Access Journals (Sweden)

    Shalu Rai

    2013-01-01

    Full Text Available Introduction: Pleomorphic adenoma (PA is the most common benign neoplasm of the major salivary glands arising primarily from the parotid gland. Computed tomography (CT is one of the primary imaging modalities used to assess the tumors of salivary glands. However, magnetic resonance imaging (MRI may provide additional information over CT. Case Report: We report the case of a 60-year-old male with a slowly enlarging, well-defined, round, painless, non-fixated, rubber-like swelling over the left ramus region below the ear, measuring about 4 × 4.5 cm, covering the lower border of the mandible near the angle. A provisional diagnosis of PA was given and CT and MRI were used to study the lesion. Discussion: Through this case, which was suspected to have undergone malignant transformation because of indistinct margins and focal hypodense areas on CT but was later confirmed to be a benign salivary gland tumor on MRI, we illustrate the role of CT and MRI as diagnostic aids in PA and emphasize on what should be the choice of imaging modality for parotid tumors.

  20. Mutual capacitance of liquid conductors in deformable tactile sensing arrays

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bin [Electrical and Computer Engineering Department, Drexel University, Philadelphia, Pennsylvania 19104 (United States); Fontecchio, Adam K. [Electrical and Computer Engineering and Materials Science and Engineering Departments, Drexel University, Philadelphia, Pennsylvania 19104 (United States); Visell, Yon [Electrical and Computer Engineering Department, Media Arts and Technology, California NanoSystems Institute, University of California, Santa Barbara, California 93106 (United States)

    2016-01-04

    Advances in highly deformable electronics are needed in order to enable emerging categories of soft computing devices ranging from wearable electronics, to medical devices, and soft robotic components. The combination of highly elastic substrates with intrinsically stretchable conductors holds the promise of enabling electronic sensors that can conform to curved objects, reconfigurable displays, or soft biological tissues, including the skin. Here, we contribute sensing principles for tactile (mechanical image) sensors based on very low modulus polymer substrates with embedded liquid metal microfluidic arrays. The sensors are fabricated using a single-step casting method that utilizes fine nylon filaments to produce arrays of cylindrical channels on two layers. The liquid metal (gallium indium alloy) conductors that fill these channels readily adopt the shape of the embedding membrane, yielding levels of deformability greater than 400%, due to the use of soft polymer substrates. We modeled the sensor performance using electrostatic theory and continuum mechanics, yielding excellent agreement with experiments. Using a matrix-addressed capacitance measurement technique, we are able to resolve strain distributions with millimeter resolution over areas of several square centimeters.

  1. The Impact of Interpixel Capacitance on WFIRST PSFs

    CERN Document Server

    Kannawadi, Arun; Mandelbaum, Rachel; Hirata, Christopher M; Kruk, Jeffrey W; Rhodes, Jason D

    2015-01-01

    Unlike optical CCDs, near-infrared detectors, which are based on CMOS hybrid readout technology, typically suffer from electrical crosstalk between the pixels. The interpixel capacitance (IPC) responsible for the crosstalk affects the point-spread function (PSF) of the telescope, increasing the size and modifying the shape of all objects in the images while correlating the Poisson noise. Upcoming weak lensing surveys that use these detectors, such as WFIRST, place stringent requirements on the PSF size and shape (and the level at which these are known), which in turn must be translated into requirements on IPC. To facilitate this process, we present a first study of the effect of IPC on WFIRST PSF sizes and shapes. Realistic PSFs are forward-simulated from physical principles for each WFIRST bandpass. We explore how the PSF size and shape depends on the range of IPC coupling with pixels that are connected along an edge or corner; for the expected level of IPC in WFIRST, IPC increases the PSF sizes by $\\sim$5\\...

  2. Bloch inductance in small-capacitance Josephson junctions.

    Science.gov (United States)

    Zorin, A B

    2006-04-28

    We show that the electrical impedance of a small-capacitance Josephson junction also includes, in addition to the capacitive term -i/(omega)CB, an inductive term i(omega)LB. Similar to the known Bloch capacitance CB(q), the Bloch inductance LB(q) also depends periodically on the quasicharge, q, and its maximum value achieved at q=e(mod 2e) always exceeds the value of the Josephson inductance of this junction LJ(phi) at fixed phi=0. The effect of the Bloch inductance on the dynamics of a single junction and a one-dimensional array is described.

  3. Human body capacitance: static or dynamic concept? [ESD

    DEFF Research Database (Denmark)

    Jonassen, Niels M

    1998-01-01

    A standing human body insulated from ground by footwear and/or floor covering is in principle an insulated conductor and has, as such, a capacitance, i.e. the ability to store a charge and possibly discharge the stored energy in a spark discharge. In the human body, the human body capacitance (HBC...... when a substantial part of the flux extends itself through badly defined stray fields. Since the concept of human body capacitance is normally used in a static (electric) context, it is suggested that the HBC be determined by a static method. No theoretical explanation of the observed differences...

  4. DLTS and capacitance transients study of defects induced by neutron irradiation in MOS structures CCD process; Etude des defauts induits par irradiation neutron dans des structures MOS par spectroscopie DLTS et reponses transitoires de capacite en fonction du temps

    Energy Technology Data Exchange (ETDEWEB)

    Ahaitouf, A.; Losson, E.; Charles, J.P. [Metz Univ., Lab. Interfaces Composants et Microelectronique, LICM/CLOES/ Supelec, 57 (France)

    1999-07-01

    The aim of this paper is to study neutron irradiation effects on PMOS capacitors and NMOSFETs transistors. The characterization of induced defects was made by capacitance transients C(t) measurements, DLTS spectroscopy, and optical DLTS (ODLTS). DLTS spectra present three peaks due to deep levels created in the semiconductor and two peaks due to minority carrier generation. Two levels are reported in the literature. Two other minority carrier traps have been observed on ODLTS spectra after irradiation. This can explain the decrease of the minority carrier generation lifetime observed by capacitance transients measurements. (authors)

  5. Bipartite Medial Cuneiform: Case Report and Retrospective Review of 1000 Magnetic Resonance (MR Imaging Studies

    Directory of Open Access Journals (Sweden)

    Geraldine H. Chang

    2014-01-01

    Full Text Available Objective. To present a unique case report of a Lisfranc fracture in a patient with a bipartite medial cuneiform and to evaluate the prevalence of the bipartite medial cuneiform in a retrospective review of 1000 magnetic resonance (MR imaging studies of the foot. Materials and Methods. Case report followed by a retrospective review of 1000 MR imaging studies of the foot for the presence or absence of a bipartite medial cuneiform. Results. The incidence of the bipartite medial cuneiform is 0.1%. Conclusion. A bipartite medial cuneiform is a rare finding but one with both clinical and surgical implications.

  6. Congenital gluteus maximus contracture syndrome - a case report with review of imaging findings

    Science.gov (United States)

    Kotha, Vamshi Krishna; Reddy, Rajasekhar; Reddy, M. Venkateshwar; Moorthy, Rangubatla Sathyanrayana; Kishan, Tatikonda Venkat

    2014-01-01

    Although the clinical features of gluteus maximus contracture syndrome have been frequently described, imaging features have been seldom described. Most commonly reported cases are those following intramuscular injection in the gluteal region although congenital contracture is an uncommon but important occurrence. This condition has most often been reported in children of school going age. These patients often present with difficulty in squatting, limitation of hip motion or specific deformities and often require surgical correction. We describe the plain radiography, ultrasonography (USG) and magnetic resonance imaging (MRI) features of this condition in a patient with no previous known history of intramuscular injections. PMID:24967033

  7. Congenital gluteus maximus contracture syndrome--a case report with review of imaging findings.

    Science.gov (United States)

    Kotha, Vamshi Krishna; Reddy, Rajasekhar; Reddy, M Venkateshwar; Moorthy, Rangubatla Sathyanrayana; Kishan, Tatikonda Venkat

    2014-04-01

    Although the clinical features of gluteus maximus contracture syndrome have been frequently described, imaging features have been seldom described. Most commonly reported cases are those following intramuscular injection in the gluteal region although congenital contracture is an uncommon but important occurrence. This condition has most often been reported in children of school going age. These patients often present with difficulty in squatting, limitation of hip motion or specific deformities and often require surgical correction. We describe the plain radiography, ultrasonography (USG) and magnetic resonance imaging (MRI) features of this condition in a patient with no previous known history of intramuscular injections.

  8. Reporter gene imaging of immune responses to cancer: progress and challenges.

    Science.gov (United States)

    Dubey, Purnima

    2012-01-01

    Immune responses to cancer are dynamic processes which take place through the concerted activity of innate and adaptive cell populations. In order to fully understand the efficacy of immune therapies for cancer, it is critical to understand how the treatment modulates the function of each cell type involved in the anti-tumor immune response. Molecular imaging is a versatile method for longitudinal studies of cellular localization and function. The development of reporter genes for tracking cell movement and function was a powerful addition to the immunologist's toolbox. This review will highlight the advances and challenges in the use of reporter gene imaging to track immune cell localization and function in cancer.

  9. Images

    Data.gov (United States)

    National Aeronautics and Space Administration — Images for the website main pages and all configurations. The upload and access points for the other images are: Website Template RSW images BSCW Images HIRENASD...

  10. Energy-Efficient Capacitance-to-Digital Converters for Low-Energy Sensor Nodes

    KAUST Repository

    Omran, Hesham

    2015-11-01

    Energy efficiency is a key requirement for wireless sensor nodes, biomedical implants, and wearable devices. The energy consumption of the sensor node needs to be minimized to avoid battery replacement, or even better, to enable the device to survive on energy harvested from the ambient. Capacitive sensors do not consume static power; thus, they are attractive from an energy efficiency perspective. In addition, they can be employed in a wide range of sensing applications. However, the sensor readout circuit–i.e., the capacitance-to-digital converter (CDC)–can be the dominant source of energy consumption in the system. Thus, the development of energy-efficient CDCs is crucial to minimizing the energy consumption of capacitive sensor nodes. In the first part of this dissertation, we propose several energy-efficient CDC architectures for low-energy sensor nodes. First, we propose a digitally-controlled coarsefine multislope CDC that employs both current and frequency scaling to achieve significant improvement in energy efficiency. Second, we analyze the limitations of successive approximation (SAR) CDC, and we address these limitations by proposing a robust parasitic-insensitive opamp-based SAR CDC. Third, we propose an inverter-based SAR CDC that achieves an energy efficiency figure-of-merit (FoM) of 31fJ/Step, which is the best energy efficiency FoM reported to date. Fourth, we propose a differential SAR CDC with quasi-dynamic operation to maintain excellent energy efficiency for a scalable sample rate. In the second part of this dissertation, we study the matching properties of small integrated capacitors, which are an integral component of energy-efficient CDCs. Despite conventional wisdom, we experimentally illustrate that the mismatch of small capacitors can be directly measured, and we report mismatch measurements for subfemtofarad integrated capacitors. We also correct the common misconception that lateral capacitors match better than vertical capacitors

  11. Capacitive, deionization with carbon aerogel electrodes: Carbonate, sulfate, and phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J.C.; Fix, D.V.; Mack, G.V.; Pekala, R.W.; Poco, J.F.

    1995-07-24

    A process for the capacitive deionization (CDI) of water with a stack of carbon aerogel electrodes has been developed by Lawrence Livermore National Laboratory. Unlike ion exchange, one of the more conventional deionization processes, no chemicals are required for regeneration of the system. Electricity is used instead. Water with various anions and cations is pumped through the electrochemical cell. After polarization, ions are electrostatically removed from the water and held in the electric double layers formed at the surfaces of electrodes. The water leaving the cell is purified, as desired. The effects of cell voltage on the electrosorption capacities for Na{sub 2}SO{sub 4}, Na{sub 3}PO{sub 4}, and Na{sub 2}CO{sub 3} have been investigated and are reported here. Results for NaCl and NaNO{sub 3} have been reported previously. Possible applications for CDI are as a replacement for ion exchange processes which remove heavy metals and radioisotopes from process and waste water in various industries, as well as to remove inorganic ions from feedwater for fossil and nuclear power plants.

  12. 电容层析成像系统中传感器状态监控和检测量在线修正%Sensor monitoring and online measurement correction in electric capacitance tomography system

    Institute of Scientific and Technical Information of China (English)

    张惠良; 荣冈

    2005-01-01

    The recalibration of electrical capacitance tomography (ECT) system is one of the key problems in keeping the system running steadily.However, for engineering application in solids/gas transport,online calibration can not be implemented and the data from this sensor may be unreliable due to the sensor pipe interior wall abrasion during pneumatic transport,so the solids concentration calculated from the reconstructed image based on these data will be highly inaccurate.The simulations show that, the inter-electrode relative capacitance variation of electrode pair spacing 1 is the most sensitive to the abrasion of sensor pipe interior wall, so this relative capacitance variation when the sensor is filled with air can be used as an indicator demanding offline system recalibration when the wall abrasion goes significant.Furthermore, while the pipe interior wall abrasion is not very serious, online correcting measured inter-electrode capacitance with wall capacitance variation can improve the accuracy of concentration calculation.

  13. TOPICAL REVIEW: Capacitive micromachined ultrasonic transducer arrays for minimally invasive medical ultrasound

    Science.gov (United States)

    Chen, Jingkuang

    2010-02-01

    This paper reviews the minimally invasive capacitive micromachined ultrasonic transducer (CMUT) arrays for medical diagnosis and therapy. While piezoelectric transducers dominate today's medical ultrasound market, the capacitive micromachined ultrasonic transducer has recently emerged as a promising alternative which delivers a comparable device performance to its piezoelectric counterparts, is compatible with front-end circuit integration, allows high-density imager integration and is relative easy in miniaturization. Utilizing MEMS technology, the substrate of CMUT arrays can be micromachined into miniature platforms with various geometrical shapes, which include needles, three-dimensional prisms, as well as other flexible-substrate configurations. These arrays are useful for reaching deep inside the tissue or an organ with a minimally invasive approach. Due to the close proximity of the transducers to the target organ/tissue, a higher resolution/accuracy of diagnostic information can be achieved. In addition to pulse-echo and photoacoustic imaging, high-power CMUT devices capable of delivering ultrasounds with a pressure greater than 1.0 MPa have been monolithically integrated with imager CMUTs for image-guided therapy (IGT). Such miniature devices would facilitate diagnostic and therapy interventions not possible with conventional piezoelectric transducers.

  14. Locating Depots for Capacitated Vehicle Routing

    CERN Document Server

    Goertz, Inge Li

    2011-01-01

    We study a location-routing problem in the context of capacitated vehicle routing. The input is a set of demand locations in a metric space and a fleet of k 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 this problem. To achieve this result, we reduce to the k-median-forest problem, which generalizes both k-median and minimum spanning tree, and which might be of independent interest. We give a (3+c)-approximation algorithm for k-median-forest, which leads to a (12+c)-approximation algorithm for the above location-routing problem, for any constant c>0. The algorithm for k-median-forest is just t-swap local search, and we prove that it has locality gap 3+2/t; this generalizes the corresponding result known for k-median. Finally we consider the "non-uniform" k-median-forest problem which has different cost ...

  15. Instabilities in a capacitively coupled oxygen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Küllig, C., E-mail: kuellig@physik.uni-greifswald.de; Wegner, Th., E-mail: physics@thwegner.com; Meichsner, J., E-mail: meichsner@physik.uni-greifswald.de [Institute of Physics, University of Greifswald, Felix-Hausdorff-Str. 6, 17489 Greifswald (Germany)

    2015-04-15

    Periodic fluctuations in the frequency range from 0.3 to 3 kHz were experimentally investigated in capacitively coupled radio frequency (13.56 MHz) oxygen plasma. The Gaussian beam microwave interferometry directly provides the line integrated electron density fluctuations. A system of two Langmuir probes measured the floating potential spatially (axial, radial) and temporally resolved. Hence, the floating potential fluctuation development is mapped within the discharge volume and provides a kind of discharge breathing and no wave propagation. Finally, it was measured the optical emission pattern of atomic oxygen during the fluctuation as well as the RF phase resolved optical emission intensity at selected phase position of the fluctuation by an intensified charge-coupled device camera. The deduced excitation rate pattern reveals the RF sheath dynamics and electron heating mechanisms, which is changing between low and high electronegativity during a fluctuation cycle. A perturbation calculation was taken into account using a global model with 15 elementary collision processes in the balance equations for the charged plasma species (O{sub 2}{sup +}, e, O{sup −}, O{sub 2}{sup −}) and a harmonic perturbation. The calculated frequencies agree with the experimentally observed frequencies. Whereby, the electron attachment/detachment processes are important for the generation of this instability.

  16. An uncooled capacitive sensor for IR detection

    Science.gov (United States)

    Siebke, Georg; Gerngroß, Kathrin; Holik, Peter; Schmitz, Sam; Rohloff, Markus; Tätzner, Simon; Steltenkamp, Siegfried

    2014-06-01

    The beetle Melanophila acuminata detects forest fires from distances as far as 80 miles away. To accomplish this, the beetle uses highly specific IR receptors with a diameter of approximately 15 μm. These receptors are mechanoreceptors that detect deformations induced by the absorption of radiation. Although the detection mechanism is understood in principle, it is still unclear how the beetle reaches such high sensitivity. In this work, we present the biomimetic approach of an uncooled IR sensor based on the beetle's receptors. This sensor is based on a fluid-filled pressure cell and operates at room temperature. Upon absorbing IR radiation, the fluid heats up and expands. The expanding fluid deflects one electrode of a plate capacitor. By measuring the change in capacitance, the volume increase and the absorbed energy can be inferred. To prevent the risk of damage at high energy absorption, a compensation mechanism is presented in this work. The mechanism prevents large but slow volume changes inside the pressure cell by a microfluidic connection of the pressure cell with a compensation chamber. The channel and the compensation chamber act as a microfluidic low-pass filter and do not affect the overall sensitivity above an appropriate cut-off frequency. Using MEMS technology, we are able to incorporate the complete system into a silicon chip with an area of a few mm2. Here, we show a proof-of-concept and first measurements of the sensor.

  17. Design Considerations in Capacitively Coupled Plasmas

    Science.gov (United States)

    Song, Sang-Heon; Ventzek, Peter; Ranjan, Alok

    2015-11-01

    Microelectronics industry has driven transistor feature size scaling from 10-6 m to 10-9 m during the past 50 years, which is often referred to as Moore's law. It cannot be overstated that today's information technology would not have been so successful without plasma material processing. One of the major plasma sources for the microelectronics fabrication is capacitively coupled plasmas (CCPs). The CCP reactor has been intensively studied and developed for the deposition and etching of different films on the silicon wafer. As the feature size gets to around 10 nm, the requirement for the process uniformity is less than 1-2 nm across the wafer (300 mm). In order to achieve the desired uniformity, the hardware design should be as precise as possible before the fine tuning of process condition is applied to make it even better. In doing this procedure, the computer simulation can save a significant amount of resources such as time and money which are critical in the semiconductor business. In this presentation, we compare plasma properties using a 2-dimensional plasma hydrodynamics model for different kinds of design factors that can affect the plasma uniformity. The parameters studied in this presentation include chamber accessing port, pumping port, focus ring around wafer substrate, and the geometry of electrodes of CCP.

  18. Hydrogen atom kinetics in capacitively coupled plasmas

    Science.gov (United States)

    Nunomura, Shota; Katayama, Hirotaka; Yoshida, Isao

    2017-05-01

    Hydrogen (H) atom kinetics has been investigated in capacitively coupled very high frequency (VHF) discharges at powers of 16-780 mW cm-2 and H2 gas pressures of 0.1-2 Torr. The H atom density has been measured using vacuum ultra violet absorption spectroscopy (VUVAS) with a micro-discharge hollow cathode lamp as a VUV light source. The measurements have been performed in two different electrode configurations of discharges: conventional parallel-plate diode and triode with an intermediate mesh electrode. We find that in the triode configuration, the H atom density is strongly reduced across the mesh electrode. The H atom density varies from ˜1012 cm-3 to ˜1010 cm-3 by crossing the mesh with 0.2 mm in thickness and 36% in aperture ratio. The fluid model simulations for VHF discharge plasmas have been performed to study the H atom generation, diffusion and recombination kinetics. The simulations suggest that H atoms are generated in the bulk plasma, by the electron impact dissociation (e + H2 \\to e + 2H) and the ion-molecule reaction (H2 + + H2 \\to {{{H}}}3+ + H). The diffusion of H atoms is strongly limited by a mesh electrode, and thus the mesh geometry influences the spatial distribution of the H atoms. The loss of H atoms is dominated by the surface recombination.

  19. Locating Depots for Capacitated Vehicle Routing

    DEFF Research Database (Denmark)

    Gørtz, Inge Li; Nagarajan, Viswanath

    2011-01-01

    We study a location-routing problem in the context of capacitated vehicle routing. The input to k-LocVRP is a set of demand locations in a metric space and a fleet of k 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. To achieve this result, we reduce k-LocVRP to the following generalization of k median, which might be of independent interest. Given a metric (V, d), bound k...... median forest, which leads to a (12+E)-approximation algorithm for k-LocVRP, for any constant E > 0. The algorithm for k median forest is t-swap local search, and we prove that it has locality gap 3 + 2 t ; this generalizes the corresponding result for k median [3]. Finally we consider the k median...

  20. Leaf thermal and hydraulic capacitances - structural safeguards for rapid ambient fluctuations

    Science.gov (United States)

    Schymanski, S. J.; Or, D.; Zwieniecki, M.

    2011-12-01

    Leaves may be subjected to rapidly fluctuating irradiation or thermal conditions due to motion of sun flecks and clouds or passage of warm and dry wind gusts. Given a stomatal characteristic time scale (~5 min) for adjusting transpiration flux, fluctuations of environmental conditions at shorter time scales (~1 min) could push leaf hydraulic and thermal status beyond its operational limits resulting in xylem cavitation or overheating. As active stomatal protection may not be adequate, we propose that leaf thermal and hydraulic capacitances and hence leaf specific mass (hydrated thickness) provide passive protection and play a critical role for autonomous and intrinsic capacitive-based responses to rapid fluctuations. For example, a simple variable leaf mass per unit area can affect both thermal and hydraulic capacitances. Thus a thin leaf (0.2 mm) exposed to a sunfleck can experience an increase in leaf temperature by 20K in the order of 3 minutes, i.e. before stomata can activate evaporative cooling. Increasing leaf thickness can be an effective measure to increase the buffer for such environmental fluctuations, so that slower regulatory measures such as stomatal adjustments can take over before detrimental effects take place. Systematic measurements of thermal changes in response to step changes in radiation conditions were obtained using laser illumination and infra-red thermal imaging of leaf laser-illuminated area across a wide range of leaf morphologies from major plant divisions (ferns, gymnosperms and angiosperms). Results confirm inverse relationships between leaf thickness and temperature rise (measured as steady state temperature increase). Hydraulic impacts of such structural capacitance on xylem function will be discussed.

  1. Uremic encephalopathy with isolated brainstem involvement revealed by magnetic resonance image: a case report.

    Science.gov (United States)

    Jia, Li-Jing; Qu, Zhen-Zhen; Zhang, Xue-Qian; Tian, Yu-Juan; Wang, Ying

    2017-08-08

    Uremic Encephalopathy (UE) is a neurological complication associated with acute or chronic renal failure. Imaging findings of UE may present involvement of the basal ganglia, cortical or subcortical regions, and white matter. We report a rare case of UE caused by neurogenic bladder with isolated brainstem involvement revealed by magnetic resonance imaging (MRI). Immediate therapy resulted in full recovery of neurological signs and changes on MRI. A 14-year-old Han Chinese woman with a history of chronic renal failure caused by neurogenic bladder. On admission, she was unconscious and her pupils presented different sizes, while her vital signs were normal. MRI showed high signal in the dorsal pontine base and in the mid brain on fluid-attenuated inversion-recovery (FLAIR) imaging and on T2-weighted imaging while the signal was normal on diffusion-weighted images (DWI). Blood analysis revealed renal failure and acidosis. After urinary retention treatment and acidosis correction, the patient soon recovered. Follow-up MRI 2 months after the discharge revealed complete resolution of UE in the brainstem. We reported a rare case of a patient with UE that had unusual imaging manifestations for whom timely diagnosis and treatment assured recovery.

  2. An imaging checklist for pre-FESS CT: framing a surgically relevant report

    Energy Technology Data Exchange (ETDEWEB)

    Vaid, S., E-mail: vaids@vsnl.co [Department of Radiology and Imaging, Grant Medical Foundation, Pune (India); Vaid, N. [Department of Otorhinolaryngology, K.E.M. Hospital, Pune (India); Rawat, S. [Department of Radiology and Imaging, Grant Medical Foundation, Pune (India); Ahuja, A.T. [Department of Diagnostic Radiology and Organ Imaging, The Chinese University of Hong Kong (Hong Kong)

    2011-05-15

    The reference standard for preoperative imaging in functional endoscopic sinus surgery (FESS) is multiplanar high-resolution computed tomography (HRCT). Surgeons require a precise preoperative anatomical road map, and hence it is essential for radiologists to be familiar with the normal three-dimensional sinonasal anatomy and the normal variants encountered in this region. Sagittal imaging has recently emerged as an important tool to visualize additional details in this critical anatomical region. Radiologists also need to report these examinations with special focus on the surgeon's expectations. Constant communication between the radiologist and the surgeon helps to resolve specific issues and improve the overall quality of reports. This results in better preoperative patient counselling and in predicting postoperative improvement in clinical status. This review provides a basic structured format for reporting pre-FESS CT, which can be tailored to meet individual requirements. The CT reporting format follows the order in which the sinonasal structures are approached during surgery.

  3. Fringe Capacitance of a Parallel-Plate Capacitor.

    Science.gov (United States)

    Hale, D. P.

    1978-01-01

    Describes an experiment designed to measure the forces between charged parallel plates, and determines the relationship among the effective electrode area, the measured capacitance values, and the electrode spacing of a parallel plate capacitor. (GA)

  4. Integration of Capacitive Micromachined Ultrasound Transducers to Microfluidic Devices

    KAUST Repository

    Viržonis, Darius

    2013-10-22

    The design and manufacturing flexibility of capacitive micromachined ultrasound transducers (CMUT) makes them attractive option for integration with microfluidic devices both for sensing and fluid manipulation. CMUT concept is introduced here by presentin

  5. Voidage measurement based on genetic algorithm and electrical capacitance tomography

    Institute of Scientific and Technical Information of China (English)

    WANG Wei-wei; WANG Bao-liang; HUANG Zhi-yao; LI Hai-qing

    2005-01-01

    A new voidage measurement method based on electrical capacitance tomography (ECT) technique, Genetic Algorithm (GA) and Partial Least Square (PLS) method was proposed. The voidage measurement model, linear capacitance combination, was developed to measure on-line voidage. GA and PLS method were used to determine the coefficients of the voidage measurement model. GA was used to explore the optimal capacitance combination which gave significant contribution to the voidage measurement. PLS method was applied to determine the weight coefficient of the contribution of each capacitance to the voidage measurement. Flow pattern identification result was introduced to improve the voidage measurement accuracy. Experimental results showed that the proposed voidage measurement method is effective and that the measurement accuracy is satisfactory.

  6. 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.

  7. High Voltage Bi-directional Flyback Converter for Capacitive Actuator

    DEFF Research Database (Denmark)

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

    2013-01-01

    This paper presents a high voltage DC-DC converter topology for bi-directional energy transfer between a low voltage DC source and a high voltage capacitive load. The topology is a bi-directional flyback converter with variable switching frequency control during the charge mode, and constant...... switching frequency control during the discharge mode. The converter is capable of charging the capacitive load from 24 V DC source to 2.5 kV, and discharges it to 0 V. The flyback converter has been analyzed in detail during both charge and discharge modes, by considering all the parasitic elements...... 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...

  8. 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, ......, including linear as well as switched mode amplifiers. In the past much attention has been paid on the driver for piezoelectric actuator. As DEAP is a type of new material, there is not much literature reference for it.......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...

  9. Quantum Capacitance of a Topological Insulator-Ferromagnet Interface.

    Science.gov (United States)

    Siu, Zhuo Bin; Chowdhury, Debashree; Jalil, Mansoor B A; Basu, Banasri

    2017-03-24

    We study the quantum capacitance in a topological insulator thin film system magnetized in the in-plane direction in the presence of an out-of-plane magnetic field and hexagonal warping. To first order, the modification in quantum capacitance due to hexagonal warping compared to the clean case, where both the in-plane magnetization and hexagonal warping are absent, is always negative, and increases in magnitude monotonically with the energy difference from the charge neutrality point. In contrast, the change in the quantum capacitance due to in-plane magnetization oscillates with the energy in general, except when a certain relation between the inter-surface coupling, out of plane Zeeman energy splitting and magnetic field strength is satisfied. In this special case, the quantum capacitance remains unchanged by the in-plane magnetization for all energies.

  10. development and testing of a capacitive digital soil moisture metre

    African Journals Online (AJOL)

    user

    moisture affects crop growth, seed development, root development and agricultural ... benefits, capacitive sensor techniques are applied in precision agriculture [3]. ..... lentil moisture content using dielectric properties. Journal of Agricultural ...

  11. Prostaglandin modulation of mouse and human sperm capacitation.

    Science.gov (United States)

    Herrero, M B; Viggiano, J M; Boquet, M; Gimeno, M A

    1997-09-01

    To determine whether prostaglandins produce a capacitation and/or acrosome reaction, the effect of prostaglandins on capacitated mouse spermatozoa and the effect of prostaglandin pre-incubation on human and mouse spermatozoa were studied. Prostaglandins did not induce an acrosome reaction in capacitated mouse sperm. PGE1 pre-incubation in a protein-free medium enhanced acrosome loss of mouse sperm challenged with A-23187 or solubilized mouse zona pellucida. Human sperm were pre-incubated in media containing prostaglandins, and an acrosome reaction was induced with calcium ionophore or human follicular fluid. PGE1 pre-incubation enhanced acrosome loss by human sperm when the action was induced with calcium ionophore, but had no effect on follicular fluid induction. We conclude that PGE1 acts as a capacitating factor in vitro for mouse spermatozoa, and enhances acrosome-reaction induction with calcium ionophore in human spermatozoa.

  12. Structure and Capacitance of Electrical Double Layers inside Micropores

    Science.gov (United States)

    Feng, Guang; Qiao, Rui; Huang, Jingsong; Sumpter, Bobby G.; Meunier, Vincent

    2010-03-01

    Recent experiments indicate that the specific capacitance of micropores (diameter less than 2nm) increases anomalously as the pore size decreases^[1]. To understand the physical origin of this discovery, we performed a series of molecular dynamics simulations to study the electrical double layers (EDLs) in micropores with different shapes (tube vs slit) and pore sizes (0.668nm - 3.342nm). Several different aqueous electrolytes (K^+, Na^+, Cl^-, and F^- in water) were used in these micropores. We quantified the structure of EDLs inside the pores, and computed the capacitance of EDLs. The scaling of capacitance shows a qualitative agreement with the experimental observations. We attribute the anomalous enhancement of capacitance in micropores to the short-range ionelectrode and ionsolvent interactions.[1] J. Chmiola, G. Yushin, Y. Gogotsi, C. Portet, P. Simon, and P.L. Taberna, Science 2006, 313, 1760.

  13. MEMS variable capacitance devices utilizing the substrate: I. Novel devices with a customizable tuning range

    KAUST Repository

    Elshurafa, Amro M.

    2010-03-22

    This paper, the first in a series of two, presents a paradigm shift in the design of MEMS parallel plate PolyMUMPS variable capacitance devices by proposing two structures that utilize the substrate and are able to provide predetermined, customizable, tuning ranges and/or ratios. The proposed structures can provide theoretical tuning ranges anywhere from 4.9 to 35 and from 3.4 to 26 respectively with a simple, yet effective, layout modification as opposed to the previously reported devices where the tuning range is fixed and cannot be varied. Theoretical analysis is carried out and verified with measurements of fabricated devices. The first proposed device possessed initially a tuning range of 4.4. Two variations of the structure having tuning ranges of 3 and 3.4, all at 1 GHz, were also successfully developed and tested. The second proposed variable capacitance device behaved as a switch. © 2010 IOP Publishing Ltd.

  14. Deep trap levels in CdS solar cells observed by capacitance measurements

    Science.gov (United States)

    Hmurcik, L.; Ketelsen, L.; Serway, R. A.

    1982-05-01

    Capacitance measurements have been carried out as a function of reverse bias voltage and signal frequency on thin-film and single-crystal CdS solar cells. It is shown that such measurements can reveal abrupt changes in C-V plots which are attributed to the presence of deep trapping states. The anomalous change in capacitance occurs when the bias voltage raises a trapping state above the Fermi level; the strength of the anomalies depends on several factors including temperature, signal frequency, and junction properties. Measurements taken on the CdS cells indicate that at least two deep trapping states are present in the partially formed i layer of CdS, which is consistent with results reported by other workers.

  15. Hepatic Angiomyolipoma Demonstrating Similar Imaging Characteristics as Hepatocellular Carcinoma: One Case Report

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Angiomyolipoma (AML) is a benign mesenchymal tumor that has been frequently reported in the kidney but rarely in the liver[1]. AML is composed of fat, vascular, and smooth muscle elements. Because the proportion of the constituents composed of AML are varied, hepatic AML may be clinically, radiologically and morphologically difficult to distinguish from hepatocellular carcinoma (HCC) or other hepatic lesions. Here we report a case with pathologically confirmed hepatic AML who was previously diagnosed as HCC based on imaging examinations.

  16. Imaging findings of cavernous hemangioma arising from the transverse colon: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Hwan; Kim, Ho Kyun; Lee, Hye Kyung; Shim, Jae Chan; Lee, Ghi Jai; Lee, Kyoung Eun; Suh, Jung Ho [Seoul Paik Hospital, Inje University College of Medicine, Seoul, (Korea, Republic of)

    2013-12-15

    Diffuse cavernous hemangioma (DCH) of the large bowel is a rare disease and usually involves the rectosigmoid colon. There have been only a few reports on the CT and MR imaging findings of DCH of the large bowel which are helpful in its correct diagnosis. We report herein an asymptomatic patient with DCH of the transverse colon and describe the CT and MRI features of the colon.

  17. Negative capacitance for various electrode materials in organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Roesch, Roland; Hoppe, Harald [Institute of Physics, TU Ilmenau (Germany); Pivrikas, Almantas; Sariciftci, Niyazi Serdar [LIOS, Johannes Kepler University Linz (Austria)

    2009-07-01

    Electrical behaviour of bulk heterojunction polymer solar cells is strongly influenced by their contacts. Charge carrier injection/extraction at contact-active layer interface depends on type of contact. In the literature different models - Schottky-contact, thermionic injection and injection via hopping processes - for the cathode contact are discussed. We use different contact materials and investigate the resulting capacitance via impedance spectroscopy, a non-invasive technique for electrical analysis. We observe a dependence of Negative Capacitance on contact type.

  18. Modeling high-frequency capacitance in SOI MOS capacitors

    Science.gov (United States)

    Łukasiak, Lidia; Jasiński, Jakub; Beck, Romuald B.; Ikraiam, Fawzi A.

    2016-12-01

    This paper presents a model of high frequency capacitance of a SOI MOSCAP. The capacitance in strong inversion is described with minority carrier redistribution in the inversion layer taken into account. The efficiency of the computational process is significantly improved. Moreover, it is suitable for the simulation of thin-film SOI structures. It may also be applied to the characterization of non-standard SOI MOSCAPS e.g. with nanocrystalline body.

  19. Capacitance Variation of Electrolyte-Gated Bilayer Graphene Based Transistors

    OpenAIRE

    Hediyeh Karimi; Rubiyah Yusof; Mohammad Taghi Ahmadi; Mehdi Saeidmanesh; Meisam Rahmani; Elnaz Akbari; Wong King Kiat

    2013-01-01

    Quantum capacitance of electrolyte-gated bilayer graphene field-effect transistors is investigated in this paper. Bilayer graphene has received huge attention due to the fact that an energy gap could be opened by chemical doping or by applying external perpendicular electric field. So, this extraordinary property can be exploited to use bilayer graphene as a channel in electrolyte-gated field-effect transistors. The quantum capacitance of bi-layer graphene with an equivalent circuit is presen...

  20. 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.

  1. 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.

  2. Comment on “Carbon nanotube/graphene composite for enhanced capacitive deionization performance” by Y. Wimalasiri and L. Zou

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Porada, S.; Presser, V.

    2013-01-01

    In a recent study, Wimalasiri and Zou [1] have reported the use and performance of composite electrodes of carbon nanotubes (CNT) and graphene for application as porous electrodes in capacitive deionization (CDI). While CDI is emerging as an attractive technology for water desalination, and novel

  3. Comment on “Carbon nanotube/graphene composite for enhanced capacitive deionization performance” by Y. Wimalasiri and L. Zou

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Porada, S.; Presser, V.

    2013-01-01

    In a recent study, Wimalasiri and Zou [1] have reported the use and performance of composite electrodes of carbon nanotubes (CNT) and graphene for application as porous electrodes in capacitive deionization (CDI). While CDI is emerging as an attractive technology for water desalination, and novel el

  4. Imaging findings of a primary paraganglioma of the liver: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Seung Woo; Kang, Ung Rae; Park, Jae Bok [Daegu Catholic University Medical Center, Catholic University of Daegu College of Medicine, Daegu (Korea, Republic of)

    2016-11-15

    Primary hepatic paraganglioma is an extremely rare type of tumor originating from extra-adrenal chromaffin cells. We report a case of primary intrahepatic paraganglioma in a 52-year-old man, with pathologic confirmation through right hepatectomy. An imaging study indicated a predominately hemorrhagic septated cystic mass and peripheral marked enhancement of the solid portions, which showed persistent enhancement.

  5. [The Thyroid Imaging Reporting and Data System (TIRADS) for ultrasound of the thyroid].

    Science.gov (United States)

    Russ, G; Bigorgne, C; Royer, B; Rouxel, A; Bienvenu-Perrard, M

    2011-01-01

    To develop a standardized system for analyzing and reporting thyroid ultrasound, or Thyroid Imaging Reporting and Data System (TIRADS), in order to improve the management of patients with thyroid nodules. An atlas of imaging features, a standardized vocabulary, a report template and TIRADS categories 0 to 6 were defined, based on the BI-RADS system used for mammography. The diagnostic efficacy of the system was tested by a retrospective review of 500 nodules (159 cancers and 341 benign nodules) and comparing US imaging features to histological findings. Five signs allow accurate detection of 90% of thyroid cancers. The score of a nodule can be easily defined by using an organigram. Sensitivity, specificity and odds-ratio of the score were respectively 95%, 68% and 40. TIRADS is a quality assurance tool for thyroid ultrasound. It contains an image atlas, a standardized report and categories to evaluate thyroid nodules to easily assess the risk of individual nodules being cancers and facilitate patient management. Copyright © 2011 Elsevier Masson SAS and Éditions françaises de radiologie. All rights reserved.

  6. The "Penumbra Sign" on Magnetic Resonance Images of Brodie's Abscess: A Case Report.

    Science.gov (United States)

    Afshar, Ahmadreza; Mohammadi, Afshin

    2011-12-01

    This report presents the "penumbra sign" of a Brodie's abscess in a 69-year-old male patient. The lesion was located in the proximal metaphysis of the left tibia. Histopathology confirmed the diagnosis of subacute osteomyelitis. The penumbra sign on magnetic resonance (MR) images is a helpful sign for the diagnosis of Brodie's abscess.

  7. Simulation Study on Quantum Capacitances of Graphene Nanoribbon VLSI Interconnects

    Science.gov (United States)

    Dutta, Arin; Rahman, Silvia; Nandy, Turja; Mahmood, Zahid Hasan

    2016-03-01

    In this paper, study on the capacitive effects of Graphene nanoribbon (GNR) in VLSI interconnect has been studied as a function of GNR width, Fermi function and gate voltage. The quantum capacitance of GNR has been simulated in terms of Fermi function for three different values of insulator thickness — 1.5nm, 2nm and 2.5nm. After that, quantum capacitance is studied in both degenerate and nondegenerate region with respect to Fermi function and gate voltage of range 1-5V. Then, the total capacitance of GNR is studied as a function of gate voltage of -2-5V range at degenerate and nondegenerate regions, where width of GNR is considered 4nm. Finally, the total capacitance of GNR is studied in both regions with varying GNR width, considering fixed gate voltage of 3V. After analyzing these simulations, it has been found that GNR in degenerate region shows nearly steady capacitance under a certain applied gate voltage.

  8. Optimizing the Materials Response in Humidity Capacitive Sensors

    Directory of Open Access Journals (Sweden)

    Elham Noroozi Afshar

    2015-10-01

    Full Text Available The number of humidity outputs on the cap of a cylindrical capacitance sensor is optimized by designing three different probes with direct and indirect windows. The time interval is measured within which 30-70 % humidity can influence the dielectric constant and conductivity of the capacitance when exposed to a range of relative humidity. It is then compared with a simple set-up including a simplified equivalent circuit. The direct probes had four and double outputs on the window of the cylindrical capacitive sensor while the indirect probe had a thin plastic layer only. We observed that the dielectric constant and its conductivity depend closely to the humidity outgoing pathway and also to the increasing rate of humidity between the capacitance plates. The final variation in the materials properties alters the capacitance of the sensor which is measured simply by a LCR. This technique presents a simple method for tracking the recovery and reliability of the humidity sensors over time and assists in optimizing and controlling the materials response to the relative environment humidity. As a result, by controlling the environment humidity rate (0.02 %/s., we could measure the increment rate of capacitance with accuracy of 0.01 pf/%.

  9. Osteopontin improves sperm capacitation and in vitro fertilization efficiency in buffalo (Bubalus bubalis).

    Science.gov (United States)

    Boccia, Lucia; Di Francesco, Serena; Neglia, Gianluca; De Blasi, Marina; Longobardi, Valentina; Campanile, Giuseppe; Gasparrini, Bianca

    2013-08-01

    The aim of this study was to evaluate the effect of osteopontin (OPN), an ubiquitous acid glycoprotein, on in vitro sperm capacitation and on in vitro embryo production (IVEP) efficiency in buffalo. In experiment 1, after swim-up separation the sperm were incubated in Tyrode albumin lactate pyruvate medium in the absence of capacitating agents (control), with the standard concentration of heparin (0.01 mM) and three different concentrations of OPN (0.1, 1, and 10 mcg/mL), both in the presence and absence of heparin, for 2 and 4 hours. Capacitation was assessed indirectly by estimating the percentage of acrosome-reacted sperm after incubation with lysophosphatidylcholine. In order to determine the effect of OPN, in the presence of heparin, on fertilization (Experiment 2) and in vitro embryo development (experiment 3), in vitro-matured buffalo oocytes were fertilized in the presence of 0, 0.1, 1, and 10 mcg/mL of OPN. After IVF, the presumptive zygotes were dezonated, fixed, stained, and then evaluated microscopically. At Days 5 and 7 of culture, the cleavage and blastocyst rates were evaluated, respectively. Two hours of treatment with OPN at the two higher concentrations (1 and 10 mcg/mL) promoted in vitro capacitation of buffalo sperm (experiment 1). A synergic action of OPN with heparin was also done for all OPN concentrations tested. At 4 hours incubation, all treatments, including heparin (20.4%), improved (P < 0.01) capacitation compared with the control (16.2%). Interestingly, the best results were reported in all groups treated with OPN + heparin (40.8%, 38.6%, and 33.8%, respectively; P < 0.01). The addition of OPN to the IVF medium had a positive influence on total penetration, synchronous pronuclei formation (experiment 2), and IVEP efficiency (experiment 3). In particular, the two lower concentrations of OPN (0.1 and 1 mcg/mL), compared with the control, gave higher synchronous pronuclei formation (73.5%, 75.0%, and 46.5%, respectively; P < 0.01) and

  10. Electrochemical capacitance of iron oxide nanotube (Fe-NT): effect of annealing atmospheres

    Science.gov (United States)

    Sarma, Biplab; Jurovitzki, Abraham L.; Ray, Rupashree S.; Smith, York R.; Mohanty, Swomitra K.; Misra, Mano

    2015-07-01

    The effect of annealing atmosphere on the supercapacitance behavior of iron oxide nanotube (Fe-NT) electrodes has been explored and reported here. Iron oxide nanotubes were synthesized on a pure iron substrate through an electrochemical anodization process in an ethylene glycol solution containing 3% H2O and 0.5 wt.% NH4F. Subsequently, the annealing of the nanotubes was carried out at 500 °C for 2 h in various gas atmospheres such as air, oxygen (O2), nitrogen (N2), and argon (Ar). The morphology and crystal phases evolved after the annealing processes were examined via field emission scanning electron microscopy, x-ray diffraction, Raman spectroscopy, and x-ray photoelectron spectroscopy. The electrochemical capacitance properties of the annealed Fe-NT electrodes were evaluated by conducting cyclic voltammetry (CV), galvanostatic charge-discharge, and electrochemical impedance spectroscopy tests in the Li2SO4 electrolyte. Based on these experiments, it was found that the capacitance of the Fe-NT electrodes annealed in air and O2 atmospheres shows mixed behavior comprising both the electric double layer and pseudocapacitance. However, annealing in N2 and Ar environments resulted in well-defined redox peaks in the CV profiles of the Fe-NT electrodes, which are therefore attributed to the relatively higher pseudonature of the capacitance in these electrodes. Based on the galvanostatic charge-discharge studies, the specific capacitance achieved in the Fe-NT electrode after annealing in Ar was about 300 mF cm-2, which was about twice the value obtained for N2-annealed Fe-NTs and three times higher than those annealed in air and O2. The experiments also demonstrated excellent cycle stability for the Fe-NT electrodes with 83%-85% capacitance retention, even after many charge-discharge cycles, irrespective of the gas atmospheres used during annealing. The increase in the specific capacitance was discussed in terms of increased oxygen vacancies as a result of the

  11. Validating tyrosinase homologue melA as a photoacoustic reporter gene for imaging Escherichia coli.

    Science.gov (United States)

    Paproski, Robert J; Li, Yan; Barber, Quinn; Lewis, John D; Campbell, Robert E; Zemp, Roger

    2015-10-01

    To understand the pathogenic processes for infectious bacteria, appropriate research tools are required for replicating and characterizing infections. Fluorescence and bioluminescence imaging have primarily been used to image infections in animal models, but optical scattering in tissue significantly limits imaging depth and resolution. Photoacoustic imaging, which has improved depth-to-resolution ratio compared to conventional optical imaging, could be useful for visualizing melA-expressing bacteria since melA is a bacterial tyrosinase homologue which produces melanin. Escherichia coli-expressing melA was visibly dark in liquid culture. When melA-expressing bacteria in tubes were imaged with a VisualSonics Vevo LAZR system, the signal-to-noise ratio of a 9×dilution sample was 55, suggesting that ∼20 bacteria cells could be detected with our system. Multispectral (680, 700, 750, 800, 850, and 900 nm) analysis of the photoacoustic signal allowed unmixing of melA-expressing bacteria from blood. To compare photoacoustic reporter gene melA (using Vevo system) with luminescent and fluorescent reporter gene Nano-lantern (using Bruker Xtreme In-Vivo system), tubes of bacteria expressing melA or Nano-lantern were submerged 10 mm in 1% Intralipid, spaced between Photoacoustic imaging could resolve the two tubes of melA-expressing bacteria even when the tubes were less than 1 mm from each other, while bioluminescence and fluorescence imaging could not resolve the two tubes of Nano-lantern-expressing bacteria even when the tubes were spaced 10 mm from each other. After injecting 100-μL of melA-expressing bacteria in the back flank of a chicken embryo, photoacoustic imaging allowed visualization of melA-expressing bacteria up to 10-mm deep into the embryo. Photoacoustic signal from melA could also be separated from deoxy- and oxy-hemoglobin signal observed within the embryo and chorioallantoic membrane. Our results suggest that melA is a useful photoacoustic reporter gene

  12. MEMS variable capacitance devices utilizing the substrate: II. Zipping varactors

    KAUST Repository

    Elshurafa, Amro M.

    2010-03-22

    This paper, the second and last in this series, introduces PolyMUMPS zipping varactors that exploit the substrate and provide a high tuning range and a high quality factor. Building on the important findings of part I of this paper, the substrate was utilized effectively once again in the design and fabrication of zipping varactors to attain devices with very good performance. Two zipping varactors are proposed, analysed theoretically, simulated, fabricated and tested successfully. The tuning range, quality factor and actuation voltage of those varactors are 4.5, 16.4, 55 V and 4.2, 17, 55 V respectively. Finally, and based on one of the proposed zipping varactors, a very large capacitance value varactor array, with a tuning range of 5.3, was designed and tested. To the best of our knowledge, these zipping varactors exhibit the best reported characteristics in PolyMUMPS to date within their category in terms of tuning range, quality factor, required actuation voltage and total area consumed. © 2010 IOP Publishing Ltd.

  13. A simple capacitive method to evaluate ethanol fuel samples

    Science.gov (United States)

    Vello, Tatiana P.; de Oliveira, Rafael F.; Silva, Gustavo O.; de Camargo, Davi H. S.; Bufon, Carlos C. B.

    2017-01-01

    Ethanol is a biofuel used worldwide. However, the presence of excessive water either during the distillation process or by fraudulent adulteration is a major concern in the use of ethanol fuel. High water levels may cause engine malfunction, in addition to being considered illegal. Here, we describe the development of a simple, fast and accurate platform based on nanostructured sensors to evaluate ethanol samples. The device fabrication is facile, based on standard microfabrication and thin-film deposition methods. The sensor operation relies on capacitance measurements employing a parallel plate capacitor containing a conformational aluminum oxide (Al2O3) thin layer (15 nm). The sensor operates over the full range water concentration, i.e., from approximately 0% to 100% vol. of water in ethanol, with water traces being detectable down to 0.5% vol. These characteristics make the proposed device unique with respect to other platforms. Finally, the good agreement between the sensor response and analyses performed by gas chromatography of ethanol biofuel endorses the accuracy of the proposed method. Due to the full operation range, the reported sensor has the technological potential for use as a point-of-care analytical tool at gas stations or in the chemical, pharmaceutical, and beverage industries, to mention a few. PMID:28240312

  14. Novel nitrogen doped graphene sponge with ultrahigh capacitive deionization performance

    Science.gov (United States)

    Xu, Xingtao; Sun, Zhuo; Chua, Daniel H. C.; Pan, Likun

    2015-06-01

    As water shortage has become a serious global problem, capacitive deionization (CDI) with high energy efficiency and low cost, is considered as a promising desalination technique to solve this problem. To date, CDI electrodes are mainly made up of porous carbon materials. However, the electrosorption performance obtained by now still cannot meet the demand of practical application. Therefore, a rationally designed structure of electrode materials has been an urgent need for CDI application. Here, a novel nitrogen-doped graphene sponge (NGS), with high specific surface area and rationally designed structure was fabricated, and used as CDI electrodes for the first time. The results show that NGS exhibits an ultrahigh electrosorption capacity of 21.0 mg g-1 in ˜500 mg L-1 NaCl solution, and to our knowledge, it is the highest value reported for carbon electrodes in similar experimental conditions by now. NGS in this work is expected to be a promising candidate as CDI electrode material.

  15. A simple capacitive method to evaluate ethanol fuel samples

    Science.gov (United States)

    Vello, Tatiana P.; de Oliveira, Rafael F.; Silva, Gustavo O.; de Camargo, Davi H. S.; Bufon, Carlos C. B.

    2017-02-01

    Ethanol is a biofuel used worldwide. However, the presence of excessive water either during the distillation process or by fraudulent adulteration is a major concern in the use of ethanol fuel. High water levels may cause engine malfunction, in addition to being considered illegal. Here, we describe the development of a simple, fast and accurate platform based on nanostructured sensors to evaluate ethanol samples. The device fabrication is facile, based on standard microfabrication and thin-film deposition methods. The sensor operation relies on capacitance measurements employing a parallel plate capacitor containing a conformational aluminum oxide (Al2O3) thin layer (15 nm). The sensor operates over the full range water concentration, i.e., from approximately 0% to 100% vol. of water in ethanol, with water traces being detectable down to 0.5% vol. These characteristics make the proposed device unique with respect to other platforms. Finally, the good agreement between the sensor response and analyses performed by gas chromatography of ethanol biofuel endorses the accuracy of the proposed method. Due to the full operation range, the reported sensor has the technological potential for use as a point-of-care analytical tool at gas stations or in the chemical, pharmaceutical, and beverage industries, to mention a few.

  16. Digitally controlled oscillator design with a variable capacitance XOR gate

    Institute of Scientific and Technical Information of China (English)

    Manoj Kumar; Sandeep K. Arya; Sujata Pandey

    2011-01-01

    A digitally controlled oscillator (DCO) using a three-transistor XOR gate as the variable load has been presented.A delay cell using an inverter and a three-transistor XOR gate as the variable capacitance is also proposed.Three-,five- and seven-stage DCO circuits have been designed using the proposed delay cell.The output frequency is controlled digitally with bits applied to the delay cells.The three-bit DCO shows output frequency and power consumption variation in the range of 3.2486-4.0267 GHz and 0.6121-0.3901 mW,respectively,with a change in the control word 1 1 1-000.The five-bit DCO achieves frequency and power of 1.8553-2.3506 GHz and 1.0202-0.6501 mW,respectively,with a change in the control word 11111-00000.Moreover,the seven-bit DCO shows a frequency and power consumption variation of 1.3239-1.6817 GHz and 1.4282-0.9102 m W,respectively,with a varying control word 1111111-0000000.The power consumption and output frequency of the proposed circuits have been compared with earlier reported circuits and the present approaches show significant improvements.

  17. Deep in vivo photoacoustic imaging of mammalian tissues using a tyrosinase-based genetic reporter

    Science.gov (United States)

    Jathoul, Amit P.; Laufer, Jan; Ogunlade, Olumide; Treeby, Bradley; Cox, Ben; Zhang, Edward; Johnson, Peter; Pizzey, Arnold R.; Philip, Brian; Marafioti, Teresa; Lythgoe, Mark F.; Pedley, R. Barbara; Pule, Martin A.; Beard, Paul

    2015-04-01

    Photoacoustic imaging allows absorption-based high-resolution spectroscopic in vivo imaging at a depth beyond that of optical microscopy. Until recently, photoacoustic imaging has largely been restricted to visualizing the vasculature through endogenous haemoglobin contrast, with most non-vascularized tissues remaining invisible unless exogenous contrast agents are administered. Genetically encodable photoacoustic contrast is attractive as it allows selective labelling of cells, permitting studies of, for example, specific genetic expression, cell growth or more complex biological behaviours in vivo. In this study we report a novel photoacoustic imaging scanner and a tyrosinase-based reporter system that causes human cell lines to synthesize the absorbing pigment eumelanin, thus providing strong photoacoustic contrast. Detailed three-dimensional images of xenografts formed of tyrosinase-expressing cells implanted in mice are obtained in vivo to depths approaching 10 mm with a spatial resolution below 100 μm. This scheme is a powerful tool for studying cellular and genetic processes in deep mammalian tissues.

  18. Expressiveness of the Breast Imaging Reporting and Database System (BI-RADS).

    OpenAIRE

    Starren, J.; Johnson, S.M.

    1997-01-01

    The Breast Imaging Reporting and Database System (BI-RADS) was developed by the American College of Radiology and is used by a number of computerized mammography tracking systems. The ability of BI-RADS to encode the data contained in 300 mammography reports at the Columbia-Presbyterian Medical Center was examined. BI-RADS was able to encode normal reports and "special masses" (such as lymph nodes) without difficulty. However, none of the general masses and only 17% of the calcifications coul...

  19. Expressiveness of the Breast Imaging Reporting and Database System (BI-RADS).

    OpenAIRE

    Starren, J.; Johnson, S.M.

    1997-01-01

    The Breast Imaging Reporting and Database System (BI-RADS) was developed by the American College of Radiology and is used by a number of computerized mammography tracking systems. The ability of BI-RADS to encode the data contained in 300 mammography reports at the Columbia-Presbyterian Medical Center was examined. BI-RADS was able to encode normal reports and "special masses" (such as lymph nodes) without difficulty. However, none of the general masses and only 17% of the calcifications coul...

  20. Column flotation monitoring based on electrical capacitance volume tomography: A preliminary study

    Science.gov (United States)

    Haryono, Didied; Harjanto, Sri; Nugraha, Harisma; Huda, Mahfudz Al; Taruno, Warsito Purwo

    2017-01-01

    A preliminary study of column flotation monitoring process using electrical capacitance volume tomography (ECVT) was conducted. ECVT was one of the monitoring systems which based on the capacitance measurement. It was used to understand the phenomenon that occurs inside the column in a three-dimensional (3-D) image. A linear back projection (LBP) algorithm technique was used to reconstruct the 3-D ECVT images from all measurement data obtained in this study. As a preliminary study, the effect of gas injection in the two-phase (liquid and gas) system was conducted. This study is conducted to assess the possibility of ECVT system in the monitoring of column flotation process. The experiments were conducted by using column flotation with 5 cm diameter and 150 cm height in which a sparger was installed at the bottom of column to inject air inside the column. 32-CH rectangular ECVT sensor was installed at 13 cm above the sparger and placed around the column. The gas injection variations used were 2-7 l/min with interval 1 l/min and all experiments were conducted at room temperature. Based on the signal and image analysis, the signals and 3-D ECVT images showed differences when the gas injection was varied. An increase in gas injection will decrease the fluctuation of signal intensity which correlates to the 3-D ECVT images. Average signals obtained by ECVT when given gas injection variations were in the range of 440.09 to 453.62 mV from high to low gas injection. Based on these results, ECVT has a prospect as an imaging tool to monitor the column flotation process. And also, hopefully, based on the analysis of 3-D images generated by ECVT system, the metallurgical performance would be analyzed in the further researches.

  1. Dengue encephalitis with predominant cerebellar involvement: Report of eight cases with MR and CT imaging features

    Energy Technology Data Exchange (ETDEWEB)

    Hegde, Vinay; Bhat, Maya; Prasad, Chandrajit; Gupta, A.K.; Saini, Jitender [National Institute of Mental Health and Neurosciences, Department of Neuroimaging and Interventional Radiology, Bangalore, Karnataka (India); Aziz, Zarina [Sri Sathya Sai Institute of Medical Science, Department of Radiology, Bangalore (India); Kumar, Sharath [Apollo Hospital, Department of Neuroradiology, Bangalore (India); Netravathi, M. [National Institute of Mental Health and Neurosciences, Department of Neurology, Bangalore (India)

    2014-11-01

    CNS dengue infection is a rare condition and the pattern of brain involvement has not been well described. We report the MR imaging (MRI) features in eight cases of dengue encephalitis. We retrospectively searched cases of dengue encephalitis in which imaging was performed. Eight cases (three men, five women; age range: 8-42 years) diagnosed with dengue encephalitis were included in the study. MR studies were performed on 3-T and 1.5-T MR clinical systems. Two neuroradiologists retrospectively reviewed the MR images and analysed the type of lesions, as well as their distribution and imaging features. All eight cases exhibited MRI abnormalities and the cerebellum was involved in all cases. In addition, MRI signal changes were also noted in the brainstem, thalamus, basal ganglia, internal capsule, insula, mesial temporal lobe, and cortical and cerebral white matter. Areas of susceptibility, diffusion restriction, and patchy post-contrast enhancement were the salient imaging features in our cohort of cases. A pattern of symmetrical cerebellar involvement and presence of microbleeds/haemorrhage may serve as a useful imaging marker and may help in the diagnosis of dengue encephalitis. (orig.)

  2. [The use of magnetic resonance imaging in the diagnosis of plantar fibromatosis: a case report].

    Science.gov (United States)

    Halefoğlu, Ahmet Mesrur

    2005-01-01

    Plantar fibromatosis is a benign but infiltrative neoplasm, presenting as a slow-growing nodular thickening most often within the central band of the plantar aponeurosis. In this case report, we presented a 43-year-old male patient who had a tender nodule in the sole of the right foot for two years. On magnetic resonance images, the location and signal intensity characteristics of the lesion were suggestive of plantar fibromatosis, which was histologically confirmed following an incisional biopsy. Magnetic resonance imaging is a noninvasive method for confirmation of the clinical diagnosis of plantar fibromatosis and also has an important role in planning surgical treatment by delineating the extent of the lesion.

  3. Fetal MR Imaging Analysis of Sirenomelia with Clinico Radiographic Correlation: A Case Report.

    Science.gov (United States)

    Nori, Madhavi; Prasad, Raghavendra G; Reddy, Arvind K; Cheguri, Sandeep Reddy

    2016-06-01

    Sirenomelia is a social curiosity, a medical and diagnostic challenge prenatally compounded by varied diagnostic difficulties. Prenatal diagnosis of sirenomelia was and continues to be a challenge although von klippel et al., described a case at 10 weeks of gestational age. However, they needed a second imaging at 12(th) week for confirmation. First trimester or early second trimester anatomic survey on ultrasound and MRI is accurate for the diagnosis thereby avoiding unnecessary complex pregnancy. We report a case of second trimester diagnosed sirenomelia, with detailed analysis of image findings on ultrasound and fetal MRI.

  4. MR imaging of mucinous carcinoma of the breast associated with ductal carcinoma in situ: case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Youn Jeong; Kim, Mi Young; Cho, Young Up; Kim, Sei Joong; Kim, Won Hong; Suh, Chang Hae; Han, Jee Young [Inha University Hospital, Incheon (Korea, Republic of)

    2007-01-15

    A mucinous carcinoma of the breast is an uncommon carcinoma containing mucin that is associated with a mucocele-like tumor or other malignant tumors. We report the MR imaging findings of two cases, a mucinous carcinoma and ductal carcinoma in situ (DCIS), associated with mucocele-like tumor. The mucinous carcinoma showed a gradually enhancing kinetic pattern on the dynamic MR and high signal intensity on the T2-weighted images. The MR findings were indistinguishable from a common benign mass of the breast.

  5. Imaging B. anthracis heme catabolism in mice using the IFP1.4 gene reporter

    Science.gov (United States)

    Zhu, Banghe; Robinson, Holly; Wilganowski, Nathaniel; Nobles, Christopher L.; Sevick-Muraca, Eva; Maresso, Anthony

    2012-03-01

    B. anthracis is a gram-positive, spore-forming bacterium which likes all pathogenic bacteria, survive by sequestering heme from its host. To image B. anthracis heme catabolism in vivo, we stably transfect new red excitable fluorescent protein, IFP1.4, that requires the heme catabolism product biliverdin (BV). IFP1.4 reporter has favorable excitation and emission characteristics, which has an absorption peak at 685 nm and an emission peak at 708 nm. Therefore, IFP1.4 reporter can be imaged deeply into the tissue with less contamination from tissue autofluorescence. However, the excitation light "leakage" through optical filters can limit detection and sensitivity of IFP1.4 reporter due to the small Stoke's shift of IFP1.4 fluorescence. To minimize the excitation light leakage, an intensified CCD (ICCD) based infrared fluorescence imaging device was optimized using two band pass filters separated by a focus lens to increase the optical density at the excitation wavelength. In this study, a mouse model (DBA/J2) was first injected with B. anthracis bacteria expressing IFP1.4, 150 μl s.c., on the ventral side of the left thigh. Then mouse was given 250 μl of a 1mM BV solution via I.V. injection. Imaging was conducted as a function of time after infection under light euthanasia, excised tissues were imaged and IFP1.4 fluorescence correlated with standard culture measurements of colony forming units (CFU). The work demonstrates the use of IFP1.4 as a reporter of bacterial utilization of host heme and may provide an important tool for understanding the pathogenesis of bacterial infection and developing new anti-bacterial therapeutics.

  6. Emphasis on the MR imaging findings of brown tumor: a report of five cases

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Won Sun; Sung, Mi Sook; Chun, Kyung-Ah; Kim, Jee-Young; Lim, Hyun Wook; Lim, Yeon Soo; Yoo, Won Jong; Chung, Myung Hee [The Catholic University of Korea, College of Medicine, Bucheon St. Mary' s Hospital, Department of Radiology, Sosa-dong, Bucheon, Kyunggi-do (Korea, Republic of); Park, Sun-Won [Seoul National University, College of Medicine, Boramae Medical Center, Department of Radiology, Dongjak-gu, Seoul (Korea, Republic of); Lee, Kee-Haeng [The Catholic University of Korea, Department of Orthopaedic Surgery, Bucheon St. Mary' s Hospital, Sosa-dong, Bucheon, Kyunggi-do (Korea, Republic of)

    2011-02-15

    Brown tumors are focal reactive osteolytic lesions that are encountered in patients with primary or secondary hyperparathyroidism, and these tumors have nonspecific magnetic resonance (MR) imaging findings. However, there are only a few reports on MR imaging of brown tumors. The purpose of this study is to describe the spectrum of MR imaging findings of brown tumors. The MR imaging features of five patients with clinical and pathological evidence of brown tumor were retrospectively reviewed by two radiologists. The patients had primary hyperparathyroidism, which was confirmed as parathyroid adenoma (n = 2) and parathyroid carcinoma (n = 3). The MR images were evaluated for the presence of solid or cystic portions, the signal intensity of the lesions, the contrast enhancement pattern and the presence of cortex destruction and fluid-fluid levels. Twelve bone lesions were detected on the MR images of five patients; three lesions in two patients, four lesions in one patient, and one lesion in two patients. The tumor was solid in three lesions, mixed solid and cystic in four, and cystic in five. All the solid lesions were accompanied by mixed lesions. Discontinuity of the cortex and adjacent soft-tissue enhancement were seen in all the solid lesions. Fluid-fluid levels were seen in two cases within the cystic component of the mixed lesions and cystic lesions. The five patients with brown tumor demonstrated a wide spectrum of MR imaging findings. There are few lesions that are osteolytic on the radiographs and that show a short T2 on MR imaging, such as brown tumor. Multiple cystic or mixed lesions are the expected findings of brown tumors. (orig.)

  7. Optical characteristics for capacitively and inductively radio frequency discharge and post-discharge of helium

    Energy Technology Data Exchange (ETDEWEB)

    Tanışlı, Murat, E-mail: mtanisli@anadolu.edu.tr; Şahin, Neslihan [Department of Physics, Anadolu University, Yunusemre Campus 26470 Eskişehir (Turkey)

    2016-01-15

    The optical properties for radiofrequency (RF) post-discharge of pure helium (He) with two different methods as capacitively and inductively have been presented using the modified Boltzmann method in comparison. Optical emission spectroscopy (OES) is often used in the diagnosis of laboratory plasma, such as gas discharge plasma. OES is a very useful method for calculating of the electron temperature in the plasma and the determination of different atoms and molecules. In this study, OES is applied for characterizations of capacitively and inductively RF He plasma at pressures between 0.62 and 2.2 mbar for newly reactor type. Plasmas are generated with an RF power generator at a frequency of 13.56 MHz and output powers of 100, 160, and 200 W. Spectra have been evaluated in the range 200–1200 nm by an optical spectrometer. At low pressure, the main spectral features reported are the wavelengths of the atomic He transitions at 388.87 and 728.13 nm. The atomic emission intensities showed a maximum in inductive system when the pressure is about 0.62 mbar. OES of capacitive discharge and inductive discharge is compared in detail. The transition for 587.56 nm is shown to be increased in time.

  8. An associative capacitive network based on nanoscale complementary resistive switches for memory-intensive computing.

    Science.gov (United States)

    Kavehei, Omid; Linn, Eike; Nielen, Lutz; Tappertzhofen, Stefan; Skafidas, Efstratios; Valov, Ilia; Waser, Rainer

    2013-06-07

    We report on the implementation of an Associative Capacitive Network (ACN) based on the nondestructive capacitive readout of two Complementary Resistive Switches (2-CRSs). ACNs are capable of performing a fully parallel search for Hamming distances (i.e. similarity) between input and stored templates. Unlike conventional associative memories where charge retention is a key function and hence, they require frequent refresh cycles, in ACNs, information is retained in a nonvolatile resistive state and normal tasks are carried out through capacitive coupling between input and output nodes. Each device consists of two CRS cells and no selective element is needed, therefore, CMOS circuitry is only required in the periphery, for addressing and read-out. Highly parallel processing, nonvolatility, wide interconnectivity and low-energy consumption are significant advantages of ACNs over conventional and emerging associative memories. These characteristics make ACNs one of the promising candidates for applications in memory-intensive and cognitive computing, switches and routers as binary and ternary Content Addressable Memories (CAMs) and intelligent data processing.

  9. The capacitive sensor for liquid level measurement, fabricated with the inkjet printing technology

    Science.gov (United States)

    Paczesny, Daniel; Tarapata, Grzegorz; Marzecki, Michał; Woyke, Michał; Jachowicz, Ryszard

    2016-11-01

    The paper reports a capacitive multisection sensor for measuring level of various liquids. Presented sensor was fully fabricated with the inkjet printing technology on thin Kapton substrate. The measurement of liquids level based on capacitive sensing is already well known technique, however the novelty of presented sensor is the technology of fabrication that was used, approach to the pattern design which combines analog and digital capacitive section and obtained self-calibration feature of whole system independently on measured liquid type. Fabricated sensor structure has dimension of 210 mm x 12 mm and the thickness approximately of 27 μm. It contains 8 digital-like sections along the sensor and one analog section which allows to fine measurements. The sensor was tested in a vessel during filling and emptying with various liquids. Performed tests exhibited the linearity of the sensor characteristic and the lack of hysteresis. Obtained sensitivity of the sensor prototype was approximately 6.8 pF/mm, but it could be easily modify on the design stage due to the fast prototyping feature of inkjet printing technology. Thanks to the flexibility of the substrate, the sensor structure can be applied to any shape of vessel. Furthermore, the sensor construction is fairly simple and costs in mass production could be extremely low. This type of sensor was design especially for autonomous cleaning and washing robots for large areas operation.

  10. Aqueous manganese dioxide ink for paper-based capacitive energy storage devices.

    Science.gov (United States)

    Qian, Jiasheng; Jin, Huanyu; Chen, Bolei; Lin, Mei; Lu, Wei; Tang, Wing Man; Xiong, Wei; Chan, Lai Wa Helen; Lau, Shu Ping; Yuan, Jikang

    2015-06-01

    We report a simple approach based on a chemical reduction method to synthesize aqueous inorganic ink comprised of hexagonal MnO2 nanosheets. The MnO2 ink exhibits long-term stability and continuous thin films can be formed on various substrates without using any binder. To obtain a flexible electrode for capacitive energy storage, the MnO2 ink was printed onto commercially available A4 paper pretreated with multiwalled carbon nanotubes. The electrode exhibited a maximum specific capacitance of 1035 F g(-1) (91.7 mF cm(-2)). Paper-based symmetric and asymmetric capacitors were assembled, which gave a maximum specific energy density of 25.3 Wh kg(-1) and a power density of 81 kW kg(-1). The device could maintain a 98.9% capacitance retention over 10 000 cycles at 4 A g(-1). The MnO2 ink could be a versatile candidate for large-scale production of flexible and printable electronic devices for energy storage and conversion.

  11. Capacitance of Ti3C2Tx MXene in ionic liquid electrolyte

    Science.gov (United States)

    Lin, Zifeng; Barbara, Daffos; Taberna, Pierre-Louis; Van Aken, Katherine L.; Anasori, Babak; Gogotsi, Yury; Simon, Patrice

    2016-09-01

    Ti3C2Tx MXene, a two-dimensional (2D) early transition metal carbide, has shown an extremely high volumetric capacitance in aqueous electrolytes, but in a narrow voltage window (less than 1.23 V). The utilization of MXene materials in ionic liquid electrolytes with a large voltage window has never been addressed. Here, we report the preparation of the Ti3C2Tx MXene ionogel film by vacuum filtration for use as supercapacitor electrodes operating in 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMI-TFSI) neat ionic liquid electrolyte. Due to the disordered structure of the Ti3C2Tx hydrogel film and a stable spacing after vacuum drying, achieved through ionic liquid electrolyte immersion of the Ti3C2Tx hydrogel film, the Ti3C2Tx surface became accessible to EMI+ and TFSI- ions. A capacitance of 70 F g-1 together with a large voltage window of 3 V was obtained at a scan rate of 20 mV s-1 in neat EMI-TFSI electrolyte. The electrochemical signature indicates a capacitive behavior even at a high scan rate (500 mV s-1) and a high power performance. This work opens up the possibilities of using MXene materials with various ionic liquid electrolytes.

  12. Capacitive charge storage at an electrified interface investigated via direct first-principles simulations

    Science.gov (United States)

    Radin, Maxwell D.; Ogitsu, Tadashi; Biener, Juergen; Otani, Minoru; Wood, Brandon C.

    2015-03-01

    Understanding the impact of interfacial electric fields on electronic structure is crucial to improving the performance of materials in applications based on charged interfaces. Supercapacitors store energy directly in the strong interfacial field between a solid electrode and a liquid electrolyte; however, the complex interplay between the two is often poorly understood, particularly for emerging low-dimensional electrode materials that possess unconventional electronic structure. Typical descriptions tend to neglect the specific electrode-electrolyte interaction, approximating the intrinsic "quantum capacitance" of the electrode in terms of a fixed electronic density of states. Instead, we introduce a more accurate first-principles approach for directly simulating charge storage in model capacitors using the effective screening medium method, which implicitly accounts for the presence of the interfacial electric field. Applying this approach to graphene supercapacitor electrodes, we find that results differ significantly from the predictions of fixed-band models, leading to improved consistency with experimentally reported capacitive behavior. The differences are traced to two key factors: the inhomogeneous distribution of stored charge due to poor electronic screening and interfacial contributions from the specific interaction with the electrolyte. Our results are used to revise the conventional definition of quantum capacitance and to provide general strategies for improving electrochemical charge storage, particularly in graphene and similar low-dimensional materials.

  13. Focal length measurement of a varifocal liquid lens with capacitance detection

    Science.gov (United States)

    Noda, Kentaro; Binh-Khiem, Nguyen; Takei, Yusuke; Takahata, Tomoyuki; Matsumoto, Kiyoshi; Shimoyama, Isao

    2014-04-01

    This paper reports on a detailed deformation model of varifocal liquid lenses fabricated by Parylene-on-liquid-deposition (POLD), which can be applied to measure and adjust the focal length of such lenses without using extra sensors or sensing mechanisms. The lens was fabricated by encapsulating a liquid between a transparent electrode and a polymer film that was covered with a metal electrode. When voltage is applied to the two electrodes, the lens deforms due to the electrostatic force, and its focal length and the capacitance between the two electrodes change simultaneously. This characteristic enables the focal length of the lens to be adjusted and detected by measuring the capacitance change. The focal length of the fabricated varifocal liquid lens changed from 153.6 to 82.6 mm by applying 150-V. The focal length change of the liquid lens was calculated from the change in its capacitance. Finally, to confirm the efficiency of this varifocal liquid lens, we fabricated a confocal distance sensor using the lens for laser scanning and demonstrated that this system can be used to measure distances of 94-140 mm with an average error of 0.83 mm and a standard deviation of 0.77 mm.

  14. Investigation of the capacitive performance of tobacco solution reduced graphene oxide

    Energy Technology Data Exchange (ETDEWEB)

    Jana, Milan [Surface Engineering and Tribology Division, Council of Scientific and Industrial Research – Central Mechanical Engineering Research Institute, Durgapur 713209 (India); Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi 110001 (India); Saha, Sanjit; Samanta, Pranab; Murmu, Naresh Chandra [Surface Engineering and Tribology Division, Council of Scientific and Industrial Research – Central Mechanical Engineering Research Institute, Durgapur 713209 (India); Lee, Joong Hee, E-mail: jhl@jbnu.ac.kr [Advanced Materials Research Institute for BIN Fusion Technology (BK Plus Global, Program), Department of BIN Fusion Technology, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Kuila, Tapas, E-mail: tkuila@gmail.com [Surface Engineering and Tribology Division, Council of Scientific and Industrial Research – Central Mechanical Engineering Research Institute, Durgapur 713209 (India)

    2015-02-01

    A facile and green approach for the reduction of graphene oxide (GO) using tobacco leaves solution was reported. The benefits of this approach were the use of green and cheap reducing agent as compared to the commercially available toxic and hazardous chemicals. Moreover, the purification of reduced GO (rGO) sheets can be avoided by using naturally occurring reducing agents. The obtained rGO sheets were characterised by Ultra violet visible, Fourier transform infrared, Raman and X-ray photo electron spectroscopy analysis. The morphologies were recorded by transmission electron and field emission scanning electron microscopy analysis and these showed the formation of a few layer rGO sheets. The electrical conductivity of rGO was found to be ∼410 S m{sup −1} at room temperature. Electrochemical performances were characterised by cyclic voltammetry, charge–discharge and electrochemical impedance spectroscopy analysis. A two electrode symmetric supercapacitor device was designed using nickel foam as current collector. The specific capacitance of the two-electrode device reached to 206 F g{sup −1} at a current density of 0.16 A g{sup −1}. The retention in specific capacitance was found to be ∼112% after 1000 charge–discharge cycles. - Highlights: • Reduced graphene has been prepared by bio-reduction of graphene oxide. • Few layers of graphene has been synthesised as observed by Raman spectra. • Two electrode based supercapacitors are fabricated. • Highest specific capacitance is found to be 206 F g{sup −1}. • Retention in specific capacitance is 112% after 1000 charge–discharge cycles.

  15. Electrical Capacitance Tomography Measurement of Flow Patterns and Film Thickness in a Thermosyphon

    Institute of Scientific and Technical Information of China (English)

    Jingtao LI; Qi CHEN; Xiangyuan DONG; Shi LIU

    2005-01-01

    An experimental study was performed to evaluate the suitability of using an electrical capacitance tomography (ECT) system to visualize the flow patterns, and to measure the film thickness of the annular flow in a two-phase closed thermosyphon (TPCT). The performance of the ECT system was examined over a range of flow conditions.The experimental data were compared with the visual observations and existing correlations. Results indicated that the ECT system, with the linear back projection (LBP) algorithm, could be used to give an on-line qualitative image of the flow patterns. The Landweber iteration algorithm with optimal step length was implemented off-line to reconstruct high-resolution images. Then, the images were analyzed to obtain the film thickness of the annular flow. The experimental data compared well with the Nusselt's equation in low vapor velocity range, but showed an increasing deficiency with the increase of vapor velocity.

  16. Design and Performance Analysis of Capacitive Micromachined Ultrasonic Transducer Linear Array

    Directory of Open Access Journals (Sweden)

    Hongliang Wang

    2014-07-01

    Full Text Available An ultrasonic transducer is a key component to achieve ultrasonic imaging. This paper designs a new type of Microelectromechanical Systems (MEMS based capacitive ultrasonic transducer and a linear array based on the transducer. Through directivity analysis, it can be found that its directivity is weak due to the small size of the designed transducer, but the directivity of the designed linear array is very strong. In order to further suppress the sidelobe interference and improve the resolution of the imaging system and imaging quality, the Dolph-Chebyshev weighting method and the Taylor weighting method are used to process −40dB sidelobe suppression, and satisfactory results are obtained, which can meet actual requirements.

  17. Mobile phone imaging and cloud-based analysis for standardized malaria detection and reporting

    Science.gov (United States)

    Scherr, Thomas F.; Gupta, Sparsh; Wright, David W.; Haselton, Frederick R.

    2016-06-01

    Rapid diagnostic tests (RDTs) have been widely deployed in low-resource settings. These tests are typically read by visual inspection, and accurate record keeping and data aggregation remains a substantial challenge. A successful malaria elimination campaign will require new strategies that maximize the sensitivity of RDTs, reduce user error, and integrate results reporting tools. In this report, an unmodified mobile phone was used to photograph RDTs, which were subsequently uploaded into a globally accessible database, REDCap, and then analyzed three ways: with an automated image processing program, visual inspection, and a commercial lateral flow reader. The mobile phone image processing detected 20.6 malaria parasites/microliter of blood, compared to the commercial lateral flow reader which detected 64.4 parasites/microliter. Experienced observers visually identified positive malaria cases at 12.5 parasites/microliter, but encountered reporting errors and false negatives. Visual interpretation by inexperienced users resulted in only an 80.2% true negative rate, with substantial disagreement in the lower parasitemia range. We have demonstrated that combining a globally accessible database, such as REDCap, with mobile phone based imaging of RDTs provides objective, secure, automated, data collection and result reporting. This simple combination of existing technologies would appear to be an attractive tool for malaria elimination campaigns.

  18. Field-effect and capacitive properties of water-gated transistors based on polythiophene derivatives

    Directory of Open Access Journals (Sweden)

    R. Porrazzo

    2015-01-01

    Full Text Available Recently, water-gated organic field-effect transistors (WGOFET have been intensively studied for their application in the biological field. Surprisingly, a very limited number of conjugated polymers have been reported so far. Here, we systematically explore a series of polythiophene derivatives, presenting different alkyl side chains lengths and orientation, and characterized by various morphologies: comparative evaluation of their performances allows highlighting the critical role played by alkyl side chains, which significantly affects the polymer/water interface capacitance. Reported results provide useful guidelines towards further development of WGOFETs and represent a step forward in the understanding of the polymer/water interface phenomena.

  19. MR imaging and ultrasonography findings of early myositis ossificans: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung Ryeol [Jeju National University Hospital, Department of Radiology, Jeju-si, Jeju Special Self-Governing Province (Korea, Republic of); Park, So Young; Jin, Wook [Kyung Hee University Hospital at Gangdong, Department of Radiology, Seoul (Korea, Republic of); Won, Kyu Yeoun [Kyung Hee University Hospital at Gangdong, Department of Pathology, Seoul (Korea, Republic of)

    2016-10-15

    Myositis ossificans (MO) is a benign soft tissue lesion with non-neoplastic heterotopic bone formation. MO in the intermediate and mature stages can be easily diagnosed if characteristic imaging findings such as a peripheral zonal pattern of ossification with variable thickness is observed. However, it is difficult to correctly diagnose early MO because it can mimic malignancy clinically, radiologically, and histopathologically. We report a case of early pseudosarcomatous phase of non-traumatic MO with atypical imaging findings. A 59-year-old woman presented with pain followed by a mass in the left thigh within a week. MR imaging and ultrasonography showed an intramuscular lesion with preserved muscle fascicles in the vastus lateralis muscle. Intralesional ossification or calcification was not seen on ultrasonography. A diagnosis of myositis ossificans was made by ultrasonographically guided biopsy. (orig.)

  20. MR imaging findings of lower extremity sepsis caused by vibro vulnificus: A report of three cases

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jihyun; Koh, Sung Hye; Min, Soo Kee; Lee, Jeong A; Lee, Kwan Seop [Hallym University College of Medicine, Hallym University Sacred Heart Hospital, Anyang (Korea, Republic of)

    2017-01-15

    Lower extremity infection caused by Vibrio vulnificus sepsis is a rapidly progressing fatal condition. Prompt diagnosis followed by early and aggressive treatment with antibiotics and fasciotomy is crucial. In this report, we described lower extremity magnetic resonance (MR) images of three patients with Vibrio vulnificus sepsis. In our cases, MR imaging of lower extremity with Vibrio vulnificus sepsis showed three common findings. First, the MR signal abnormalities appeared simultaneously in all layers, including skin, subcutaneous fat, muscles, and deep fasciae. Second, the inflammation showed symmetry on both legs. Third, none of our cases was accompanied by abscess formation. These imaging features may represent rapid progression of Vibrio vulnificus sepsis and could be helpful for accurate diagnosis, and prompt and aggressive treatment.

  1. Autoradiography study and SPECT imaging of reporter gene HSV1-tk expression in heart

    Energy Technology Data Exchange (ETDEWEB)

    Lan Xiaoli [Department of Nuclear Medicine, Union Hospital, Tongji Medical College of Huazhong University of Science and Technology, Hubei Province Key Laboratory of Molecular Imaging, Wuhan, Hubei Province, 430022 (China)], E-mail: LXL730724@hotmail.com; Liu Ying; He Yong; Wu Tao; Zhang Binqing; Gao Zairong; An Rui [Department of Nuclear Medicine, Union Hospital, Tongji Medical College of Huazhong University of Science and Technology, Hubei Province Key Laboratory of Molecular Imaging, Wuhan, Hubei Province, 430022 (China); Zhang Yongxue [Department of Nuclear Medicine, Union Hospital, Tongji Medical College of Huazhong University of Science and Technology, Hubei Province Key Laboratory of Molecular Imaging, Wuhan, Hubei Province, 430022 (China)], E-mail: zhyx1229@163.com

    2010-04-15

    Aim: To demonstrate the feasibility and optimal conditions of imaging herpes simplex virus 1-thymidine kinase (HSV1-tk) gene transferred into hearts with {sup 131}I-2'-fluoro-2'-deoxy-1-{beta}-D-arabinofuranosyl-5-iodouracil ({sup 131}I-FIAU) using autoradiography (ARG) and single photon emission computed tomography (SPECT) in animal models. Methods: HSV1-tk inserted into adenovirus vector (Ad5-tk) and adenovirus (Ad5-null) was prepared. Rats or rabbits were divided into a study group receiving intramyocardial injection of Ad5-tk, and a control group receiving Ad-null injection. In the study group of rats, two sets of experiments, time-course study and dose-dependence study, were performed. In time-course experiments, rats were injected with {sup 131}I-FIAU on Days 1, 2, 3, 5 and 7, after transfection of 1x10{sup 8} pfu Ad5-tk, to study the feasibility and suitable time course for reporter gene imaging. In dose-dependence study, various titers of Ad5-tk (5x10{sup 8}, 1x10{sup 8}, 5x10{sup 7} and 1x10{sup 7} pfu) were used to determine the threshold and optimal viral titer needed for detection of gene expression. The gamma counts of hearts were measured. The rat myocardium was analyzed by ARG and reverse transcriptase-polymerase chain reaction (RT-PCR). SPECT whole-body planar imaging and cardiac tomographic imaging were performed in the rabbit models. Results: From the ARG images, rats injected with Ad5-tk showed significant {sup 131}I-FIAU activity in the anterolateral wall compared with background signals seen in the control Ad5-null rats. In time-course study, the highest radioactivity in the focal myocardium could be seen on Day 1, and then progressively declined with time. In dose-dependence study, the level of {sup 131}I-FIAU accumulation in the transfected myocardium declined with the decrease of Ad viral titers. From the ARG analysis and gamma counting, the threshold viral titer was 5x10{sup 7} pfu, and the optimal Ad titer was 1x10{sup 8} pfu

  2. Negative capacitance for ultra-low power computing

    Science.gov (United States)

    Khan, Asif Islam

    Owing to the fundamental physics of the Boltzmann distribution, the ever-increasing power dissipation in nanoscale transistors threatens an end to the almost-four-decade-old cadence of continued performance improvement in complementary metal-oxide-semiconductor (CMOS) technology. It is now agreed that the introduction of new physics into the operation of field-effect transistors---in other words, "reinventing the transistor'"--- is required to avert such a bottleneck. In this dissertation, we present the experimental demonstration of a novel physical phenomenon, called the negative capacitance effect in ferroelectric oxides, which could dramatically reduce power dissipation in nanoscale transistors. It was theoretically proposed in 2008 that by introducing a ferroelectric negative capacitance material into the gate oxide of a metal-oxide-semiconductor field-effect transistor (MOSFET), the subthreshold slope could be reduced below the fundamental Boltzmann limit of 60 mV/dec, which, in turn, could arbitrarily lower the power supply voltage and the power dissipation. The research presented in this dissertation establishes the theoretical concept of ferroelectric negative capacitance as an experimentally verified fact. The main results presented in this dissertation are threefold. To start, we present the first direct measurement of negative capacitance in isolated, single crystalline, epitaxially grown thin film capacitors of ferroelectric Pb(Zr0.2Ti0.8)O3. By constructing a simple resistor-ferroelectric capacitor series circuit, we show that, during ferroelectric switching, the ferroelectric voltage decreases, while the stored charge in it increases, which directly shows a negative slope in the charge-voltage characteristics of a ferroelectric capacitor. Such a situation is completely opposite to what would be observed in a regular resistor-positive capacitor series circuit. This measurement could serve as a canonical test for negative capacitance in any novel

  3. Capacitance and compressibility of heterostructures with strong electronic correlations

    Science.gov (United States)

    Steffen, Kevin; Frésard, Raymond; Kopp, Thilo

    2017-01-01

    Strong electronic correlations related to a repulsive local interaction suppress the electronic compressibility in a single-band model, and the capacitance of a corresponding metallic film is directly related to its electronic compressibility. Both statements may be altered significantly when two extensions to the system are implemented which we investigate here: (i) we introduce an attractive nearest-neighbor interaction V as antagonist to the repulsive onsite repulsion U , and (ii) we consider nanostructured multilayers (heterostructures) assembled from two-dimensional layers of these systems. We determine the respective total compressibility κ and capacitance C of the heterostructures within a strong coupling evaluation, which builds on a Kotliar-Ruckenstein slave-boson technique. Whereas the capacitance C (n ) for electronic densities n close to half-filling is suppressed, illustrated by a correlation induced dip in C (n ) , it may be appreciably enhanced close to a van Hove singularity. Moreover, we show that the capacitance may be a nonmonotonic function of U close to half-filling for both attractive and repulsive V . The compressibility κ can differ from C substantially, as κ is very sensitive to internal electrostatic energies which in turn depend on the specific setup of the heterostructure. In particular, we show that a capacitor with a polar dielectric has a smaller electronic compressibility and is more stable against phase separation than a standard nonpolar capacitor with the same capacitance.

  4. 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.

  5. Recent advances in understanding the capacitive storage in microporous carbons

    Energy Technology Data Exchange (ETDEWEB)

    Daffos, B.; Taberna, P.L. [Universite de Toulouse, CIRIMAT, UMR-CNRS 5085, Toulouse (France); Gogotsi, Y. [Department of Materials Science and Engineering, A.J. Drexel Nanotechnology Institute, Drexel University, Philadelphia, PA (United States); Simon, P.

    2010-10-15

    This paper presents a review of our recent work on capacitance of carbide-derived carbons (CDCs). Specific capacitance as high as 14 {mu}F cm{sup -2} or 160 F g{sup -1} was achieved using CDCs with tailored subnanometer pore size, which is significantly higher than 6 {mu}F cm{sup -2} or 100 F g{sup -1} for conventional activated carbons. Such high capacitance was obtained in several types of organic electrolytes with or without solvent. A maximum is obtained for the carbons with the mean pore size close to the bare ion size, ruling out the traditional point of view that mesoporosity is highly required for maximum capacitance. Surprisingly, carbons with subnanometer porosity exhibit high capacitance retention, since only a 10% loss is measured when 6 A g{sup -1} discharge is drawn. These findings show the importance of fitting the ion size with the mean pore size. The double layer theory falls short to explain such charge storage mechanisms at the nanometer scale; thus atomistic modelling is required to find out an alternative charge storage model. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  6. Ultrasound plays a key role in imaging and management of genital angiomyofibroblastoma: a case report.

    Science.gov (United States)

    Wolf, Benjamin; Horn, Lars-Christian; Handzel, Romy; Einenkel, Jens

    2015-10-28

    Angiomyofibroblastoma is a benign, rare mesenchymal tumor arising from the genital tract of both men and women and was first described by Fletcher and colleagues in 1992. The tumor needs to be distinguished from other, similar lesions, such as deep and superficial aggressive angiomyxoma and cellular angiofibroma, because aggressive angiomyxoma demands much more extensive treatment. The vast majority of angiomyofibroblastomas arise from the vulva and appear as solid cystic masses on ultrasound images. We report a case of a 35-year-old Caucasian woman with an angiomyofibroblastoma arising from the vagina. She presented with a painless mass of about 5cm in diameter that had a rather homogeneous, hypoechoic appearance on ultrasound images. The patient underwent surgical resection of the mass, which was subsequently diagnosed as angiomyofibroblastoma. We present sonographic and magnetic resonance imaging findings, intraoperative and histologic images, and a thorough review of the literature. In our opinion, ultrasonography is the most valuable tool to establish a preoperative diagnosis of this tumor entity, differentiate it from other lesions of the female genital tract, and plan surgery accordingly. Even though it is a rare tumor, gynecologists should be able to recognize it and to differentiate it from other tumor entities that demand more aggressive treatment. We describe a different sonographic appearance of this tumor than previously reported.

  7. Giant cell tumor of soft tissue: a case report with emphasis on MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Moon Young; Jee, Won-Hee [The Catholic University of Korea, Department of Radiology, Seoul St. Mary' s Hospital, School of Medicine, Seocho-gu, Seoul (Korea, Republic of); Jung, Chan Kwon [The Catholic University of Korea, Department of Pathology, Seoul St. Mary' s Hospital, College of Medicine, Seocho-gu, Seoul (Korea, Republic of); Yoo, Ie Ryung [The Catholic University of Korea, Department of Nuclear Medicine, Seoul St. Mary' s Hospital, College of Medicine, Seocho-gu, Seoul (Korea, Republic of); Chung, Yang-Guk [The Catholic University of Korea, Department of Orthopedic Surgery, Seoul St. Mary' s Hospital, College of Medicine, Seocho-gu, Seoul (Korea, Republic of)

    2015-04-03

    Giant cell tumor of soft tissue is a rare neoplasm, histologically resembling giant cell tumor of bone. In this report, we describe a deep and solid giant cell tumor of soft tissue interpreted as a benign soft tissue tumor based on magnetic resonance (MR) findings with hypointense to intermediate signals on T2-weighted images and impeded diffusivity (water movement) on diffusion-weighted imaging (DWI), which could suggest a giant-cell-containing benign soft tissue tumor, despite the malignancy suggested by {sup 18}F-fluorodeoxyglucose positron emission tomography-computed tomography in a 35-year-old male. To our knowledge, this report introduces the first deep, solid giant cell tumor of soft tissue with MR features of a giant-cell-containing benign soft tissue tumor, despite the malignancy-mimicking findings on {sup 18}F-FDG PET-CT. (orig.)

  8. Three-dimensional x-ray stereometry from paired coplanar images: a progress report.

    Science.gov (United States)

    Baumrind, S; Moffitt, F H; Curry, S

    1983-10-01

    More than fifty years ago, Broadbent reported the development of a three-dimensional cephalometric method which complexed information from pairs of x-ray images oriented in two planes at right angles to each other. Empirical problems have prevented the routine clinical use of this "biplanar" method, notwithstanding its obvious conceptual brilliance. The present article reports on recent work toward the development of an alternative method of three-dimensional cephalometry in which the two images of each x-ray pair are positioned in the same plane rather than being at right angles to each other. It is believed that this "coplanar" method avoids many of the technical problems that have limited the use of the Broadbent method.

  9. Association Between Echocardiography Laboratory Accreditation and the Quality of Imaging and Reporting for Valvular Heart Disease.

    Science.gov (United States)

    Thaden, Jeremy J; Tsang, Michael Y; Ayoub, Chadi; Padang, Ratnasari; Nkomo, Vuyisile T; Tucker, Stephen F; Cassidy, Cynthia S; Bremer, Merri; Kane, Garvan C; Pellikka, Patricia A

    2017-08-01

    It is presumed that echocardiographic laboratory accreditation leads to improved quality, but there are few data. We sought to compare the quality of echocardiographic examinations performed at accredited versus nonaccredited laboratories for the evaluation of valvular heart disease. We enrolled 335 consecutive valvular heart disease subjects who underwent echocardiography at our institution and an external accredited or nonaccredited institution within 6 months. Completeness and quality of echocardiographic reports and images were assessed by investigators blinded to the external laboratory accreditation status and echocardiographic results. Compared with nonaccredited laboratories, accredited sites more frequently reported patient sex (94% versus 78%; Pheart disease. Future quality improvement initiatives should highlight the importance of high-quality color Doppler imaging and echocardiographic quantification to improve the accuracy, reproducibility, and quality of echocardiographic studies for valvular heart disease. © 2017 American Heart Association, Inc.

  10. Simulating Capacitances to Silicon Quantum Dots: Breakdown of the Parallel Plate Capacitor Model

    Science.gov (United States)

    Thorbeck, Ted; Fujiwara, Akira; Zimmerman, Neil M.

    2012-09-01

    Many electrical applications of quantum dots rely on capacitively coupled gates; therefore, to make reliable devices we need those gate capacitances to be predictable and reproducible. We demonstrate in silicon nanowire quantum dots that gate capacitances are reproducible to within 10% for nominally identical devices. We demonstrate the experimentally that gate capacitances scale with device dimensions. We also demonstrate that a capacitance simulator can be used to predict measured gate capacitances to within 20%. A simple parallel plate capacitor model can be used to predict how the capacitances change with device dimensions; however, the parallel plate capacitor model fails for the smallest devices because the capacitances are dominated by fringing fields. We show how the capacitances due to fringing fields can be quickly estimated.

  11. Estimation of Transformer Winding Capacitances through Frequency Response Analysis - An Experimental Investigation

    Science.gov (United States)

    Shah, Krupa; Ragavan, K.

    2013-10-01

    This article focuses on developing a non-invasive method for determining capacitances using frequency response data. The proposed methodology involves acquiring driving-point impedance of the winding under consideration over wide frequency range. With certain terminal conditions and using the terminal impedance measured at specific frequencies, input and shunt capacitances are determined. For the purpose of estimating series capacitance of the winding, an algorithm is proposed. To demonstrate the capability of the method, initially model coils that have provisions for connecting external capacitances are considered. Then, it is found that the estimated values of capacitances are nearly same as those of connected capacitances. The method is, then, extended to transformer winding, and a capacitive ladder network is constructed. To assess the accuracy of estimation, capacitive voltage distribution is utilized. That is, the voltage distribution in the winding is compared with that of synthesized circuit. A good agreement between those data reveals that the estimated capacitance values are accurate.

  12. Ongoing quality control in digital radiography: Report of AAPM Imaging Physics Committee Task Group 151.

    Science.gov (United States)

    Jones, A Kyle; Heintz, Philip; Geiser, William; Goldman, Lee; Jerjian, Khachig; Martin, Melissa; Peck, Donald; Pfeiffer, Douglas; Ranger, Nicole; Yorkston, John

    2015-11-01

    Quality control (QC) in medical imaging is an ongoing process and not just a series of infrequent evaluations of medical imaging equipment. The QC process involves designing and implementing a QC program, collecting and analyzing data, investigating results that are outside the acceptance levels for the QC program, and taking corrective action to bring these results back to an acceptable level. The QC process involves key personnel in the imaging department, including the radiologist, radiologic technologist, and the qualified medical physicist (QMP). The QMP performs detailed equipment evaluations and helps with oversight of the QC program, the radiologic technologist is responsible for the day-to-day operation of the QC program. The continued need for ongoing QC in digital radiography has been highlighted in the scientific literature. The charge of this task group was to recommend consistency tests designed to be performed by a medical physicist or a radiologic technologist under the direction of a medical physicist to identify problems with an imaging system that need further evaluation by a medical physicist, including a fault tree to define actions that need to be taken when certain fault conditions are identified. The focus of this final report is the ongoing QC process, including rejected image analysis, exposure analysis, and artifact identification. These QC tasks are vital for the optimal operation of a department performing digital radiography.

  13. Ongoing quality control in digital radiography: Report of AAPM Imaging Physics Committee Task Group 151

    Energy Technology Data Exchange (ETDEWEB)

    Jones, A. Kyle, E-mail: kyle.jones@mdanderson.org; Geiser, William [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Heintz, Philip [Department of Radiology, University of New Mexico, Albuquerque, New Mexico 87104 (United States); Goldman, Lee [Hartford Hospital, Hartford, Connecticut 06102 (United States); Jerjian, Khachig [Hoag Memorial Hospital, Newport Beach, California 92658 (United States); Martin, Melissa [Therapy Physics, Inc., Gardena, California 90248 (United States); Peck, Donald [Henry Ford Health System, Detroit, Michigan 48202 (United States); Pfeiffer, Douglas [Boulder Community Foothills Hospital, Boulder, Colorado 80303 (United States); Ranger, Nicole [Landauer, Inc., Glenwood, Illinois 60425 (United States); Yorkston, John [Carestream Health, Inc., Rochester, New York 14615 (United States)

    2015-11-15

    Quality control (QC) in medical imaging is an ongoing process and not just a series of infrequent evaluations of medical imaging equipment. The QC process involves designing and implementing a QC program, collecting and analyzing data, investigating results that are outside the acceptance levels for the QC program, and taking corrective action to bring these results back to an acceptable level. The QC process involves key personnel in the imaging department, including the radiologist, radiologic technologist, and the qualified medical physicist (QMP). The QMP performs detailed equipment evaluations and helps with oversight of the QC program, the radiologic technologist is responsible for the day-to-day operation of the QC program. The continued need for ongoing QC in digital radiography has been highlighted in the scientific literature. The charge of this task group was to recommend consistency tests designed to be performed by a medical physicist or a radiologic technologist under the direction of a medical physicist to identify problems with an imaging system that need further evaluation by a medical physicist, including a fault tree to define actions that need to be taken when certain fault conditions are identified. The focus of this final report is the ongoing QC process, including rejected image analysis, exposure analysis, and artifact identification. These QC tasks are vital for the optimal operation of a department performing digital radiography.

  14. Calcific myonecrosis and the role of imaging in the diagnosis: A case report

    Science.gov (United States)

    Okada, Atsushi; Hosaka, Masami; Watanuki, Munenori; Itoi, Eiji

    2009-01-01

    Calcific myonecrosis is a rare posttraumatic complication characterized by the replacement of muscles of one or more compartments with central liquefaction and peripheral calcification. We report magnetic resonance imaging (MRI) and CT imaging features of calcific myonecrosis arising 43 years after trauma. A 62-year-old man presented with a slowly enlarging mass in the left lower leg. Plain radiographs revealed a soft tissue mass with extensive amorphous calcification. The middle third of the tibia and fibula were eroded. MRI demonstrated peripheral ring enhancement on postcontrast fat-suppressed T1-weighted images. Volume-rendered images extracting only the images of bone and vessels also showed many branches from the tibialis posterior and peroneal arteries around the bone defect. During the operation, bleeding continued heavily from the vessels penetrating the cortical bone of the tibia, from the posterior compartment, and from the branches of tibialis posterior artery. The total blood loss was approximately 2,400 milliliters. There may be a causal relationship between massive bleeding and the hypervascularity of this tumor as evidenced by MRI and volume-rendering CT studies. PMID:19736609

  15. MR imaging findings in subacute combined degeneration of the spinal cord: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Jun; Lee, Jae Hee; Lee, Sung Yong; Chung, Sung Woo [Our Lady of Mercy Hospital, The Catholic University of Korea, Incheon (Korea, Republic of)

    2000-09-01

    Vitamin B12 deficiency can cause neurologic complications in the spinal cord, brain, and optic and peripheral nerves. Subacute combined degeneration is a rare disease of demyelinating lesions of the spinal cord, affecting mainly the posterior and lateral columns of the thoracic cord. We report the MR imaging findings of a case of subacute combined degeneration of the spinal cord in a patient with vitamin B12 deficiency and mega loblastic anemia. (author)

  16. Imaging Findings of Sonography and Computed Tomography for a Penile Leiomyosarcoma: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Jin; Chung, Jae Joon; Yu, Jeong Sik; Kim, Joo Hee [Gangnam Severance Hospital, Seoul (Korea, Republic of)

    2009-12-15

    We report the ultrasonographic and computed tomography (CT) findings of a deep type of penile leiomyosarcoma that helped characterize a penile mass along with a review of the published literature. Leiomyosarcoma of the penis is a very rare disease characterized by a lobulated, expansile, soft tissue mass in CT images, with peripheral rim enhancement and internal homogeneous low density. The ultrasonographic findings revealed a lobulated and heterogeneously hypoechoic solid mass at the distal tip of the penis.

  17. Parry-Romberg syndrome: findings in advanced magnetic resonance imaging sequences - case report

    Energy Technology Data Exchange (ETDEWEB)

    Paula, Rafael Alfenas de; Ribeiro, Bruno Niemeyer de Freitas, E-mail: alfenas85@gmail.com [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Hospital Universitario Clementino Fraga Filho; Bahia, Paulo Roberto Valle [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Dept. de radiologia; Ribeiro, Renato Niemeyer de Freitas [Hospital de Clinica de Jacarepagua, Rio de Janeiro, RJ (Brazil); Carvalho, Lais Balbi de [Universidade Presidente Antonio Carlos (Unipac), Juiz de Fora, MG (Brazil)

    2014-05-15

    Parry-Romberg syndrome is a rare disease characterized by progressive hemifacial atrophy associated with other systemic changes, including neurological symptoms. Currently, there are few studies exploring the utilization of advanced magnetic resonance sequences in the investigation of this disease. The authors report the case of a 45-year-old patient and describe the findings at structural magnetic resonance imaging and at advanced sequences, correlating them with pathophysiological data. (author)

  18. US and MR imaging of candidiasis of the nervous system in premature infants: two case reports

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyo Nam; Woo, Joung Joo; Bahk, Yong Whee; Kim, Soon Yong; Kim, Eun Ryoung [Sungae Hospital, Seoul (Korea, Republic of)

    2001-07-01

    Candidiasis of central nervous system (CNS) is rare condition and like other opportunistic fungal infections, most commonly occurs in immune-compromised patients. Because of the increasing use of antibiotics and the improving survival rate of premature infants requiring intensive care, the incidence of fungal infection in the brain has increased. We report the findings of ultrasonography and MR imaging in two cases of candidiasis of the CNS in premature infants.

  19. Imaging appearance of benign multicystic peritoneal mesothelioma: a case report and review of the literature.

    Science.gov (United States)

    Mehta, Varun; Chowdhary, Varun; Sharma, Richa; Golia Pernicka, Jennifer S

    Benign multicystic peritoneal mesothelioma (BMPM) is a rare entity with fewer than 150 reported cases in the literature. Here we discuss a case of BMPM in a 22-year old female as presented to our urban community hospital, review epidemiology and clinical presentations of this entity, and perform a comprehensive literature review of various CT, US, and MR imaging features of BMPM. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Nasolabial Cyst: A Case Report with Ultrasonography and Magnetic Resonance Imaging Findings

    Directory of Open Access Journals (Sweden)

    Ali Ocak

    2017-01-01

    Full Text Available Nasolabial cysts are uncommon nonodontogenic lesions that occur in the nasal alar region. These lesions usually present with asymptomatic swelling but can cause pain if infected. In this case report, we describe the inadequacy of conventional radiography in a nasolabial cyst case, as well as the magnetic resonance imaging (MRI and ultrasonography (US findings in a 54-year-old female patient.

  1. Magnetic resonance imaging findings of solitary infantile myofibromatosis of the skull: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Eun; Cho, Kil Ho; Suh, Jang Ho; Choi, Joon Hyuk [College of Medicine, Yeungnam University, Daegu (Korea, Republic of)

    2016-11-15

    Infantile myofibromatosis is a rare, benign mesenchymal disorder of early childhood characterized by solitary or multiple benign myofibroblastic tumors. The tumors may involve the skin, subcutaneous tissue, muscle, bone and visceral organs. We report magnetic resonance imaging findings of solitary infantile myofibromatosis arising in the temporal bone of a ten-month-old boy, and the diagnosis was confirmed by surgical excision and histopathological examination.

  2. How I report breast magnetic resonance imaging studies for breast cancer staging and screening.

    Science.gov (United States)

    Vinnicombe, Sarah

    2016-07-25

    Magnetic resonance imaging (MRI) of the breast is the most sensitive imaging technique for the diagnosis and local staging of primary breast cancer and yet, despite the fact that it has been in use for 20 years, there is little evidence that its widespread uncritical adoption has had a positive impact on patient-related outcomes.This has been attributed previously to the low specificity that might be expected with such a sensitive modality, but with modern techniques and protocols, the specificity and positive predictive value for malignancy can exceed that of breast ultrasound and mammography. A more likely explanation is that historically, clinicians have acted on MRI findings and altered surgical plans without prior histological confirmation. Furthermore, modern adjuvant therapy for breast cancer has improved so much that it has become a very tall order to show a an improvement in outcomes such as local recurrence rates.In order to obtain clinically useful information, it is necessary to understand the strengths and weaknesses of the technique and the physiological processes reflected in breast MRI. An appropriate indication for the scan, proper patient preparation and good scan technique, with rigorous quality assurance, are all essential prerequisites for a diagnostically relevant study.The use of recognised descriptors from a standardised lexicon is helpful, since assessment can then dictate subsequent recommendations for management, as in the American College of Radiology BI-RADS (Breast Imaging Reporting and Data System) lexicon (Morris et al., ACR BI-RADS® Atlas, Breast Imaging Reporting and Data System, 2013). It also enables audit of the service. However, perhaps the most critical factor in the generation of a meaningful report is for the reporting radiologist to have a thorough understanding of the clinical question and of the findings that will influence management. This has never been more important than at present, when we are in the throes of a

  3. Imaging in tuberculosis of the skull and skull-base: case report

    Energy Technology Data Exchange (ETDEWEB)

    Sencer, S.; Aydin, K.; Poyanli, A.; Minareci, O. [Dept. of Radiology, Istanbul School of Medicine, Istanbul Univ., Istanbul (Turkey); Sencer, A.; Hepguel, K. [Dept. of Neurological Surgery, Istanbul School of Medicine, Istanbul Univ., Istanbul (Turkey)

    2003-03-01

    We report a 19-year-old girl, who presented with headache and tonic/clonic seizures. Imaging revealed a lytic parietal skull lesion with an adjacent epidural mass, masses in the right parietal lobe and a posterior skull-base mass. The diagnosis of tuberculosis was made after resection of the extradural mass and later verified with culture of Mycobacterium tuberculosis. The parenchymal and skull-base lesions resolved following antituberculous treatment. We present CT, scintigraphic, angiographic and MRI findings. (orig.)

  4. Multi-Modal Imaging with a Toolbox of Influenza A Reporter Viruses.

    Science.gov (United States)

    Tran, Vy; Poole, Daniel S; Jeffery, Justin J; Sheahan, Timothy P; Creech, Donald; Yevtodiyenko, Aleksey; Peat, Andrew J; Francis, Kevin P; You, Shihyun; Mehle, Andrew

    2015-10-13

    Reporter viruses are useful probes for studying multiple stages of the viral life cycle. Here we describe an expanded toolbox of fluorescent and bioluminescent influenza A reporter viruses. The enhanced utility of these tools enabled kinetic studies of viral attachment, infection, and co-infection. Multi-modal bioluminescence and positron emission tomography-computed tomography (PET/CT) imaging of infected animals revealed that antiviral treatment reduced viral load, dissemination, and inflammation. These new technologies and applications will dramatically accelerate in vitro and in vivo influenza virus studies.

  5. Imaging features of gastric invasive aspergillosis: A report of two cases

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Dong Jin; Cho, Seung Hyun; Kim, Seong Hoon; Shin, Ji Yeol; Lee, Yil Gi [Daegu Fatima Hospital, Daegu (Korea, Republic of)

    2012-05-15

    Invasive aspergillosis is an opportunistic infection that usually occurs in immunocompromised patients. Although there are a few rare reports of isolated invasive aspergillosis affecting the small intestine, isolated or disseminated gastric invasive aspergillosis is extremely rare. Herein, we report 2 cases of gastric invasive aspergillosis in a 72 year old woman and a 43 year old man; the woman had been recovering from ruptured left posterior communicating artery aneurysm, which presented as emphysematous gastritis and the man from acute subdural haemorrhage in the intensive care unit, which presented as a pseudoaneurysm on CT imaging.

  6. Unusual presentations of child abuse: A report of two cases and the role of imaging

    Directory of Open Access Journals (Sweden)

    Olubukola Titilayo Abeni Omidiji

    2016-01-01

    Full Text Available Insufficient attention has been paid to child abuse in Nigeria, where corporal punishment is still acceptable both at home and in the wider public including schools. This is notlimited to the parents; these punitive measures can also be undertaken by the extended family, caregivers, and neighbors. Mild to extreme force is allowed particularly when the crime involves tarnishing the family image. We hereby report two cases of extreme discipline that can be termed as a form of child abuse to draw the attention of clinicians and radiologists to other possible findings aside from those already reported in literature.

  7. Unusual presentations of child abuse: A report of two cases and the role of imaging

    Science.gov (United States)

    Omidiji, Olubukola Titilayo Abeni; Atalabi, Omolola Mojisola; Evbuomwan, Ogbeide Ejeordamen; Okwuegbuna, Francis Ikechukwu; Oluseyi, Olugbenga

    2016-01-01

    Insufficient attention has been paid to child abuse in Nigeria, where corporal punishment is still acceptable both at home and in the wider public including schools. This is not limited to the parents; these punitive measures can also be undertaken by the extended family, caregivers, and neighbors. Mild to extreme force is allowed particularly when the crime involves tarnishing the family image. We hereby report two cases of extreme discipline that can be termed as a form of child abuse to draw the attention of clinicians and radiologists to other possible findings aside from those already reported in literature. PMID:28051056

  8. First Report of Preoperative Imaging Diagnosis of a Surgically Confirmed Case of Valentino′s Syndrome

    Directory of Open Access Journals (Sweden)

    Parag Suresh Mahajan

    2014-01-01

    Full Text Available Perforation of a duodenal ulcer (DU into the retroperitoneal space presenting with clinical features of acute appendicitis is known as Valentino′s syndrome. Post duodenal perforation, the gastric and duodenal fluids tend to settle in the right paracolic gutter causing peritonitis and clinically mimicking acute appendicitis. Only three cases of Valentino′s syndrome have been reported till date in the published literature and there is only one previous report of its preoperative imaging diagnosis. To our knowledge, this is the first reported case of preoperative imaging diagnosis in a surgically confirmed case of Valentino′s syndrome. In most cases, patients with undiagnosed Valentino′s syndrome are operated for acute appendicitis, and on finding a normal appendix, search is made for the cause of peritonitis, which then leads to retroperitoneal perforation of duodenum. The diagnosis of Valentino′s syndrome by computed tomography (CT imaging is easy and can help in avoiding the surgery or directing the surgeon directly to the repair of the duodenal perforation. It is, therefore, essential for emergency physicians, surgeons, and radiologists to know about this entity and consider it in the differential diagnosis.

  9. Interoperative fundus image and report sharing in compliance with integrating the healthcare enterprise conformance and web access todigital imaging and communication in medicinepersistent object protocol

    Directory of Open Access Journals (Sweden)

    Hui-Qun Wu

    2013-12-01

    Full Text Available AIM:To address issues in interoperability between different fundus image systems, we proposed a web eye-picture archiving and communication system (PACS framework in conformance with digital imaging and communication in medicine (DICOM and health level 7 (HL7 protocol to realize fundus images and reports sharing and communication through internet.METHODS: Firstly, a telemedicine-based eye care work flow was established based on integrating the healthcare enterprise (IHE Eye Care technical framework. Then, a browser/server architecture eye-PACS system was established in conformance with the web access to DICOM persistent object (WADO protocol, which contains three tiers.RESULTS:In any client system installed with web browser, clinicians could log in the eye-PACS to observe fundus images and reports. Multipurpose internet mail extensions (MIME type of a structured report is saved as pdf/html with reference link to relevant fundus image using the WADO syntax could provide enough information for clinicians. Some functions provided by open-source Oviyam could be used to query, zoom, move, measure, view DICOM fundus images.CONCLUSION:Such web eye-PACS in compliance to WADO protocol could be used to store and communicate fundus images and reports, therefore is of great significance for teleophthalmology.

  10. Last-passage Monte Carlo algorithm for mutual capacitance.

    Science.gov (United States)

    Hwang, Chi-Ok; Given, James A

    2006-08-01

    We develop and test the last-passage diffusion algorithm, a charge-based Monte Carlo algorithm, for the mutual capacitance of a system of conductors. The first-passage algorithm is highly efficient because it is charge based and incorporates importance sampling; it averages over the properties of Brownian paths that initiate outside the conductor and terminate on its surface. However, this algorithm does not seem to generalize to mutual capacitance problems. The last-passage algorithm, in a sense, is the time reversal of the first-passage algorithm; it involves averages over particles that initiate on an absorbing surface, leave that surface, and diffuse away to infinity. To validate this algorithm, we calculate the mutual capacitance matrix of the circular-disk parallel-plate capacitor and compare with the known numerical results. Good agreement is obtained.

  11. Noise and mismatch optimization for capacitive MEMS readout

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Chong; Wu Qisong; Yin Tao; Yang Haigang, E-mail: yanghg@mail.ie.ac.c [Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China)

    2009-11-15

    This paper presents a high precision CMOS readout circuit for a capacitive MEMS gyroscope. A continuous time topology is employed as well as the chopper noise cancelling technique. A detailed analysis of the noise and mismatch of the capacitive readout circuit is given. The analysis and measurement results have shown that thermal noise dominates in the proposed circuit, and several approaches should be used for both noise and mismatch optimization. The circuit chip operates under a single 5 V supply, and has a measured capacitance resolution of 0.2 aF/sq rootHz. With such a readout circuit, the gyroscope can accurately measure the angular rate with a sensitivity of 15.3 mV/{sup 0}/s. (semiconductor integrated circuits)

  12. Noise and mismatch optimization for capacitive MEMS readout

    Institute of Scientific and Technical Information of China (English)

    Zhang Chong; Wu Qisong; Yin Tao; Yang Haigang

    2009-01-01

    This paper presents a high precision CMOS readout circuit for a capacitive MEMS gyroscope. A continuous time topology is employed as well as the chopper noise cancelling technique. A detailed analysis of the noise and mismatch of the capacitive readout circuit is given. The analysis and measurement results have shown that thermal noise dominates in the proposed circuit, and several approaches should be used for both noise and mismatch optimization. The circuit chip operates under a single 5 V supply, and has a measured capacitance resolution of 0.2 aF/√Hz. With such a readout circuit, the gyroscope can accurately measure the angular rate with a sensitivity of 15.3 mV/°/s.

  13. 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 microfabr......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...

  14. Extracting Impurity Locations using Scanning Capacitance Microscopy Measurements

    Directory of Open Access Journals (Sweden)

    AGHAEI, S.

    2016-08-01

    Full Text Available In this article we investigate the possibility to use scanning capacitance microscopy (SCM for the 2-D and 3-D "atomistic" dopant profiling of semiconductor materials. For this purpose, we first analyze the effects of random dopant fluctuations (RDF on SCM measurements with nanoscale probes and show that the discrete and random locations of dopant impurities significantly affect the differential capacitance measured in SCM experiments if the dimension of the probe is below 50 nm. Then, we present an algorithm to compute the x, y, and z coordinates of the ionized impurities in the semiconductor material using a set of SCM measurements. The algorithm is based on evaluating the doping sensitivity functions of the differential capacitance and uses a gradient-based iterative method to compute the locations of dopants. Finally, we discuss a standard simulation case and show that we are able to successfully retrieve the locations of the ionized impurities using the proposed algorithm.

  15. Preamplifiers for non-contact capacitive biopotential measurements*

    Science.gov (United States)

    Peng, GuoChen; Ignjatovic, Zeljko; Bocko, Mark F.

    2014-01-01

    Non-contact biopotential sensing is an attractive measurement strategy for a number of health monitoring applications, primarily the ECG and the EEG. In all such applications a key technical challenge is the design of a low-noise trans-impedance preamplifier for the typically low-capacitance, high source impedance sensing electrodes. In this paper, we compare voltage and charge amplifier designs in terms of their common mode rejection ratio, noise performance, and frequency response. Both amplifier types employ the same operational-transconductance amplifier (OTA), which was fabricated in a 0.35um CMOS process. The results show that a charge amplifier configuration has advantages for small electrode-to-subject coupling capacitance values (less than 10 pF - typical of noncontact electrodes) and that the voltage amplifier configuration has advantages for electrode capacitances above 10 pF. PMID:24109979

  16. Preamplifiers for non-contact capacitive biopotential measurements.

    Science.gov (United States)

    Peng, GuoChen; Ignjatovic, Zeljko; Bocko, Mark F

    2013-01-01

    Non-contact biopotential sensing is an attractive measurement strategy for a number of health monitoring applications, primarily the ECG and the EEG. In all such applications a key technical challenge is the design of a low-noise trans-impedance preamplifier for the typically low-capacitance, high source impedance sensing electrodes. In this paper, we compare voltage and charge amplifier designs in terms of their common mode rejection ratio, noise performance, and frequency response. Both amplifier types employ the same operational-transconductance amplifier (OTA), which was fabricated in a 0.35 um CMOS process. The results show that a charge amplifier configuration has advantages for small electrode-to-subject coupling capacitance values (less than 10 pF--typical of noncontact electrodes) and that the voltage amplifier configuration has advantages for electrode capacitances above 10 pF.

  17. A Wearable Capacitive Sensor for Monitoring Human Respiratory Rate

    Science.gov (United States)

    Kundu, Subrata Kumar; Kumagai, Shinya; Sasaki, Minoru

    2013-04-01

    Realizing an untethered, low-cost, and comfortably wearable respiratory rate sensor for long-term breathing monitoring application still remains a challenge. In this paper, a conductive-textile-based wearable respiratory rate sensing technique based on the capacitive sensing approach is proposed. The sensing unit consists of two conductive textile electrodes that can be easily fabricated, laminated, and integrated in garments. Respiration cycle is detected by measuring the capacitance of two electrodes placed on the inner anterior and posterior sides of a T-shirt at either the abdomen or chest position. A convenient wearable respiratory sensor setup with a capacitance-to-voltage converter has been devised. Respiratory rate as well as breathing mode can be accurately identified using the designed sensor. The sensor output provides significant information on respiratory flow. The effectiveness of the proposed system for different breathing patterns has been evaluated by experiments.

  18. Quantum Capacitance Modifies Interionic Interactions in Semiconducting Nanopores

    CERN Document Server

    Lee, Alpha A; Goriely, Alain

    2016-01-01

    Nanopores made with low dimensional semiconducting materials, such as carbon nanotubes and graphene slit pores, are used in supercapacitors. In theories and simulations of their operation, it is often assumed that such pores screen ion-ion interactions like metallic pores, i.e. that screening leads to an exponential decay of the interaction potential with ion separation. By introducing a quantum capacitance that accounts for the density of states in the material, we show that ion-ion interactions in carbon nanotubes and graphene slit pores actually decay algebraically with ion separation. This result suggests a new avenue of capacitance optimization based on tuning the electronic structure of a pore: a marked enhancement in capacitance might be achieved by developing nanopores made with metallic materials or bulk semimetallic materials.

  19. 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.

  20. Extraction method for parasitic capacitances and inductances of HEMT models

    Science.gov (United States)

    Zhang, HengShuang; Ma, PeiJun; Lu, Yang; Zhao, BoChao; Zheng, JiaXin; Ma, XiaoHua; Hao, Yue

    2017-03-01

    A new method to extract parasitic capacitances and inductances for high electron-mobility transistors (HEMTs) is proposed in this paper. Compared with the conventional extraction method, the depletion layer is modeled as a physically significant capacitance model and the extrinsic values obtained are much closer to the actual results. In order to simulate the high frequency behaviour with higher precision, series parasitic inductances are introduced into the cold pinch-off model which is used to extract capacitances at low frequency and the reactive elements can be determined simultaneously over the measured frequency range. The values obtained by this method can be used to establish a 16-elements small-signal equivalent circuit model under different bias conditions. The results show good agreements between the simulated and measured scattering parameters up to 30 GHz.

  1. On Machine Capacitance Dimensional and Surface Profile Measurement System

    Science.gov (United States)

    Resnick, Ralph

    1993-01-01

    A program was awarded under the Air Force Machine Tool Sensor Improvements Program Research and Development Announcement to develop and demonstrate the use of a Capacitance Sensor System including Capacitive Non-Contact Analog Probe and a Capacitive Array Dimensional Measurement System to check the dimensions of complex shapes and contours on a machine tool or in an automated inspection cell. The manufacturing of complex shapes and contours and the subsequent verification of those manufactured shapes is fundamental and widespread throughout industry. The critical profile of a gear tooth; the overall shape of a graphite EDM electrode; the contour of a turbine blade in a jet engine; and countless other components in varied applications possess complex shapes that require detailed and complex inspection procedures. Current inspection methods for complex shapes and contours are expensive, time-consuming, and labor intensive.

  2. 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...... consumption of different amplifier topologies. Next, low power features of different amplifier types are analyzed on transistor level. A brief comparison of SI circuits for low power applications vs. SC circuits is presented. Methodologies for low voltage design is presented. This is followed by a collection...... 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...

  3. SEMICONDUCTOR DEVICES Multi-bias capacitance voltage characteristic of AlGaN/GaN HEMT

    Science.gov (United States)

    Yan, Pu; Liang, Wang; Tingting, Yuan; Sihua, Ouyang; Lei, Pang; Guoguo, Liu; Weijun, Luo; Xinyu, Liu

    2010-10-01

    The method of multi-bias capacitance voltage measurement is presented. The physical meaning of gate—source and gate—drain capacitances in AlGaN/GaN HEMT and the variations in them with different bias conditions are discussed. A capacitance model is proposed to reflect the behaviors of the gate—source and gate—drain capacitances, which shows a good agreement with the measured capacitances, and the power performance obtains good results compared with the measured data from the capacitance model.

  4. Penicillamine prevents ram sperm agglutination in media that support capacitation.

    Science.gov (United States)

    Leahy, T; Rickard, J P; Aitken, R J; de Graaf, S P

    2016-02-01

    Ram spermatozoa are difficult to capacitate in vitro. Here we describe a further complication, the unreported phenomenon of head-to-head agglutination of ram spermatozoa following dilution in the capacitation medium Tyrodes plus albumin, lactate and pyruvate (TALP). Sperm agglutination is immediate, specific and persistent and is not associated with a loss of motility. Agglutination impedes in vitro sperm handling and analysis. So the objectives of this study were to investigate the cause of sperm agglutination and potential agents which may reduce agglutination. The percentage of non-agglutinated, motile spermatozoa increased when bicarbonate was omitted from complete TALP suggesting that bicarbonate ions stimulate the agglutination process. d-penicillamine (PEN), a nucleophilic thiol, was highly effective at reducing agglutination. The inclusion of 250 μM PEN in TALP reduced the incidence of motile, agglutinated spermatozoa from 76.7 ± 2.7% to 2.8 ± 1.4%. It was then assessed if PEN (1 mM) could be included in existing ram sperm capacitation protocols (TALP +1 mM dibutyryl cAMP, caffeine and theophylline) to produce spermatozoa that were simultaneously capacitated and non-agglutinated. This protocol resulted in a sperm population which displayed high levels of tyrosine phosphorylated proteins and lipid disordered membranes (merocyanine-540) while remaining motile, viable, acrosome-intact and non-agglutinated. In summary, PEN (1 mM) can be included in ram sperm capacitation protocols to reduce sperm agglutination and allow for the in vitro assessment of ram sperm capacitation.

  5. Breast Imaging Reporting and Data System (BI-RADS) breast composition descriptors: Automated measurement development for full field digital mammography

    OpenAIRE

    Fowler, E. E.; Sellers, T.A.; Lu, B.; Heine, J.J.

    2013-01-01

    Purpose: The Breast Imaging Reporting and Data System (BI-RADS) breast composition descriptors are used for standardized mammographic reporting and are assessed visually. This reporting is clinically relevant because breast composition can impact mammographic sensitivity and is a breast cancer risk factor. New techniques are presented and evaluated for generating automated BI-RADS breast composition descriptors using both raw and calibrated full field digital mammography (FFDM) image data.

  6. Comprehensive measurements of GaAs pixel detectors capacitance

    CERN Document Server

    Caria, M; D'Auria, S; Lai, A; Randaccio, P; Cadeddu, S

    2002-01-01

    We have studied GaAs pixel detectors on semi-insulating wafers with Schottky contacts. We performed comprehensive measurements on the inter-pixel and capacitance to back plane. Being semi-insulating, the behaviour is totally different with respect to other common semiconductors, such as high resistivity silicon. Non-homogeneities are also an issue, due to both the contacts and the crystal bulk. In order to detect them and their influence on capacitance, we undertook systematic measurements with different configurations of the measuring electrodes.

  7. Capacitive Touch User Interface and Implementation with Virtual Refrigerator

    Directory of Open Access Journals (Sweden)

    MIT Academy of Engineering Global Technology and Engineering centre, Whirlpool of India

    2014-05-01

    Full Text Available The proposed User Interface incorporates 14 Touch keys, including slider and wheeler functionality using self capacitance technology, 24 side throw LED with intensity controlled Fade-IN, Fade-OUT effects, Buzzer chime, Voltage regulator circuit, and communication circuitry for the control board. The major advantage that this User Interface is that the entire assembly is less than 10mm thick including PCB, components, light guide and graphics sticker. In this project the mentioned capacitive touch user Interface is interfaced with a Lab view system simulating a virtual refrigerator capable of responding to the commands from the User Interface.

  8. Quantum capacitance in monolayers of silicene and related buckled materials

    Science.gov (United States)

    Nawaz, S.; Tahir, M.

    2016-02-01

    Silicene and related buckled materials are distinct from both the conventional two dimensional electron gas and the famous graphene due to strong spin orbit coupling and the buckled structure. These materials have potential to overcome limitations encountered for graphene, in particular the zero band gap and weak spin orbit coupling. We present a theoretical realization of quantum capacitance which has advantages over the scattering problems of traditional transport measurements. We derive and discuss quantum capacitance as a function of the Fermi energy and temperature taking into account electron-hole puddles through a Gaussian broadening distribution. Our predicted results are very exciting and pave the way for future spintronic and valleytronic devices.

  9. [Impact of sperm capacitation on various populations of human spermatozoa].

    Science.gov (United States)

    Villanueva Díaz, C; Suárez Juárez, M; Díaz, M A; Ayala Ruiz, A

    1989-02-01

    With the purpose of evaluating the impact of spermatic capacitation on different spermatozooa populations, 49 samples of semen, before and after in vitro spermatic capacitation with Ham F-10 medium, were studied; motility of cells was evaluated according to WHO criteria. There was diminution of percentage of immobile cells, 27.8 to 20.0, as well as increase in population of cells with more mobility, 28.6% to 39.1%. Both difference were statistically significant (p = less than 0.05 and p = less than 0.005, respectively). These data suggest that spermatic capacitacion activates "in cascade" all groups of gametes.

  10. Nickel Oxide/Carbon Nanotubes Nanocomposite for Electrochemical Capacitance

    Institute of Scientific and Technical Information of China (English)

    Kui LIANG; Kayhyeok AN; Younghee LEE

    2005-01-01

    A nanocomposite of nickel oxide/carbon nanotubes was prepared through a simple chemical precipitation followed by thermal annealing. The electrochemical capacitance of this electrode material was studied. When the mass fraction of CNTs (carbon nanotubes) in NiO/CNT composites increases, the electrical resistivity of nanocomposites decreases and becomes similar to that of pure CNTs when it reaches 30%. The specific surface area of composites increases with increasing CNT mass fraction and the specific capacitance reaches 160 F/g under 10 mA/g discharge current density at CNT mass fraction of 10%.

  11. Micromachined capacitive pressure sensor with signal conditioning electronics

    DEFF Research Database (Denmark)

    Fragiacomo, Giulio

    Micromachined capacitive pressure sensors for harsh environment together with interfacing electronic circuits have been studied in this project. Micro-electromechanical systems (MEMS) have been proposed as substitutes for macro scale sensor’s systems in many different fields and are the only...... a great deal of sensors are used. Pressure sensors are among the most successful MEMS and are used in a huge variety of applications. In this project an absolute capacitive pressure sensor has been developed with the aim to integrate it in pump control systems to improve the efficiency of the pump...

  12. Skin Capacitance Mapping of Eccrine Sweat Gland Activity during Pregnancy

    Directory of Open Access Journals (Sweden)

    Claudine Piérard-Franchimont

    2016-02-01

    Full Text Available Skin capacitance mapping is a real-time non-invasive method useful in the assessment of eccrine gland activity. We presently revisit and explore the sweat gland production in pregnant women. Sprouts of sweat vapour are progressively increased during pregnancy by recruiting increasing numbers of active sweat pores. An overall moisturization of the stratum corneum ensues in absence of increased liquid sweat production. These aspects are conveniently assessed using skin capacitance mapping. The sweat duct opening could represent an increased way for percutaneous penetration of some xenobiotics during pregnancy.

  13. An Effective Hybrid Optimization Algorithm for Capacitated Vehicle Routing Problem

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Capacitated vehicle routing problem (CVRP) is an important combinatorial optimization problem. However, it is quite difficult to achieve an optimal solution with the traditional optimization methods owing to the high computational complexity. A hybrid algorithm was developed to solve the problem, in which an artificial immune clonal algorithm (AICA) makes use of the global search ability to search the optimal results and simulated annealing (SA) algorithm employs certain probability to avoid becoming trapped in a local optimum. The results obtained from the computational study show that the proposed algorithm is a feasible and effective method for capacitated vehicle routing problem.

  14. Analysis of Capacitive Parasitism in PWM Inverter-Fed Motor

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The effects of parasitic capacitance in induction motor system are unnoticed when it is fed from the AC line. but they are obvious when supplied directly from a PWM inverter. Consequently. many parasitic problems occur, such as motor-to-earth leakage current, bearing current, incoming line current distortion and uneven distribution of electrical stresses along the winding. On the ba sis of the uniform transmission line principle, a complete equivalent circuit of the PWM inverter-fed motor system is presented, based on which all the capacitive parasitic problems mentioned above are analyzed and simulated by means of PSPICE. All the results are consistent with the existing ones.

  15. Flexible Capacitive Electrodes for Minimizing Motion Artifacts in Ambulatory Electrocardiograms

    Directory of Open Access Journals (Sweden)

    Jeong Su Lee

    2014-08-01

    Full Text Available This study proposes the use of flexible capacitive electrodes for reducing motion artifacts in a wearable electrocardiogram (ECG device. The capacitive electrodes have conductive foam on their surface, a shield, an optimal input bias resistor, and guarding feedback. The electrodes are integrated in a chest belt, and the acquired signals are transmitted wirelessly for ambulatory heart rate monitoring. We experimentally validated the electrode performance with subjects standing and walking on a treadmill at speeds of up to 7 km/h. The results confirmed the highly accurate heart rate detection capacity of the developed system and its feasibility for daily-life ECG monitoring.

  16. The modelling of a capacitive microsensor for biosensing applications

    Science.gov (United States)

    Bezuidenhout, P. H.; Schoeman, J.; Joubert, T. H.

    2014-06-01

    Microsensing is a leading field in technology due to its wide application potential, not only in bio-engineering, but in other fields as well. Microsensors have potentially low-cost manufacturing processes, while a single device type can have various uses, and this consequently helps with the ever-growing need to provide better health conditions in rural parts of the world. Capacitive biosensors detect a change in permittivity (or dielectric constant) of a biological material, usually within a parallel plate capacitor structure which is often implemented with integrated electrodes of an inert metal such as gold or platinum on a microfluidic substrate typically with high dielectric constant. There exist parasitic capacitance components in these capacitive sensors, which have large influence on the capacitive measurement. Therefore, they should be considered for the development of sensitive and accurate sensing devices. An analytical model of a capacitive sensor device is discussed, which accounts for these parasitic factors. The model is validated with a laboratory device of fixed geometry, consisting of two parallel gold electrodes on an alumina (Al2O3) substrate mounted on a glass microscope slide, and with a windowed cover layer of poly-dimethyl-siloxane (PDMS). The thickness of the gold layer is 1μm and the electrode spacing is 300μm. The alumina substrate has a thickness of 200μm, and the high relative permittivity of 11.5 is expected to be a significantly contributing factor to the total device capacitance. The 155μm thick PDMS layer is also expected to contribute substantially to the total device capacitance since the relative permittivity for PDMS is 2.7. The wideband impedance analyser evaluation of the laboratory device gives a measurement result of 2pF, which coincides with the model results; while the handheld RLC meter readout of 4pF at a frequency of 10kHz is acceptable within the measurement accuracy of the instrument. This validated model will

  17. A Walkthrough of Nonlinear Capacitance Measurement of Outer Hair Cells.

    Science.gov (United States)

    Song, Lei; Santos-Sacchi, Joseph

    2016-01-01

    Nonlinear capacitance (NLC) measures are often used as surrogate measures of outer hair cell (OHC) electromotility (eM), since the two are commonly thought to share many biophysical features. The measurement of NLC is simpler than direct measurements of eM and, therefore, many investigators have adopted it. A standard patch-clamp hardware configuration is sufficient for recording NLC, given the proper software interface. Thus, the approach is cost effective. We use the software jClamp since it is tailored to capacitance measurement. Here we detail steps that we use to measure NLC. The walk through includes isolation of guinea pig OHCs, building voltage commands, recording, and analysis.

  18. Touch mode micromachined capacitive pressure sensor with signal conditioning electronics

    DEFF Research Database (Denmark)

    Fragiacomo, Giulio; Eriksen, Gert F.; Christensen, Carsten

    2010-01-01

    is one of the key challenges nowadays. In this context, house heating is a priority for environmental issues. For this reason, the possibilities of using a low power consumption technique, such as capacitive pressure sensing, in harsh environments is a concrete market opportunity. Our aim is therefore....... A measurement setup was arranged and tested for accuracy and reliability with respect to hysteresis. Finally, designs with different radii of the top plate were characterized by a capacitance versus pressure curve at different frequencies and temperatures (Fig. 3). Industrial possibilities Energy saving systems...

  19. Current Kink and Capacitance Frequency Dispersion in Silicon PIN Photodiodes

    Science.gov (United States)

    Guo, Xia; Feng, Yajie; Liu, Qiaoli; Wang, Huaqiang; Li, Chong; Hu, Zonghai; He, Xiaoying

    2017-09-01

    Silicon PIN photodiodes in the visible wavelength range have been widely applied in aerospace, defense, security, medical, and scientific instruments because of their high sensitivity and low cost. In this paper, the phenomena of the current kink and the capacitance frequency dispersion are observed. Contamination at the p-type Ohmic contact interface is proposed to explain the current kink effect and capacitance frequency dispersion, according to the temperature-dependent I-V measurement results in which trap-assisted tunneling process demonstrated.

  20. Automated Outcome Classification of Computed Tomography Imaging Reports for Pediatric Traumatic Brain Injury.

    Science.gov (United States)

    Yadav, Kabir; Sarioglu, Efsun; Choi, Hyeong Ah; Cartwright, Walter B; Hinds, Pamela S; Chamberlain, James M

    2016-02-01

    The authors have previously demonstrated highly reliable automated classification of free-text computed tomography (CT) imaging reports using a hybrid system that pairs linguistic (natural language processing) and statistical (machine learning) techniques. Previously performed for identifying the outcome of orbital fracture in unprocessed radiology reports from a clinical data repository, the performance has not been replicated for more complex outcomes. To validate automated outcome classification performance of a hybrid natural language processing (NLP) and machine learning system for brain CT imaging reports. The hypothesis was that our system has performance characteristics for identifying pediatric traumatic brain injury (TBI). This was a secondary analysis of a subset of 2,121 CT reports from the Pediatric Emergency Care Applied Research Network (PECARN) TBI study. For that project, radiologists dictated CT reports as free text, which were then deidentified and scanned as PDF documents. Trained data abstractors manually coded each report for TBI outcome. Text was extracted from the PDF files using optical character recognition. The data set was randomly split evenly for training and testing. Training patient reports were used as input to the Medical Language Extraction and Encoding (MedLEE) NLP tool to create structured output containing standardized medical terms and modifiers for negation, certainty, and temporal status. A random subset stratified by site was analyzed using descriptive quantitative content analysis to confirm identification of TBI findings based on the National Institute of Neurological Disorders and Stroke (NINDS) Common Data Elements project. Findings were coded for presence or absence, weighted by frequency of mentions, and past/future/indication modifiers were filtered. After combining with the manual reference standard, a decision tree classifier was created using data mining tools WEKA 3.7.5 and Salford Predictive Miner 7

  1. Functional Brain Imaging in Cornelia de Lange Syndrome: Case Report and Literature review.

    Science.gov (United States)

    Silva-Hernández, Frieda; Rodríguez-Cuadrado, Gloria I; Martin-Ruaigip, Ralph J; Barreras-Ávila, Lourdes; González-Chevere, Brenda; Valentin-Rivera, Roberto; Labat-Alvarez, Eduardo

    2015-01-01

    Functional brain imaging with brain single photon emission computer tomography (Brain SPECT) has been used for many years in the evaluation of multiple neuro-degenerative and neuro-developmental disorders. Brain SPECT is a nuclear medicine tomographic study performed with a lipophilic radiopharmaceutical labeled with 99mTc-pertechnetate. It is a cerebral perfusion agent that depicts the global and regional perfusion patterns in the cortical gray matter and subcortical structures. Cornelia de Lange syndrome (CdLS) is a rare neuro-developmental and genetic condition, associated to several malformations. There are a limited number of cases reported in the medical literature and few of them report neuro-radiological and/or neuro-pathologic abnormalities. We report a case of a 15 year old patient, clinically diagnosed at birth with CdLS, who presents limited anatomical findings on Computed Tomography and Magnetic Resonance Imaging. To the best of our knowledge, this is the first report of the Brain SPECT findings in this syndrome.

  2. Label-free RNA aptamer-based capacitive biosensor for the detection of C-reactive protein.

    Science.gov (United States)

    Qureshi, Anjum; Gurbuz, Yasar; Kallempudi, Saravan; Niazi, Javed H

    2010-08-28

    In this study, we report a novel aptamer-based capacitive label-free biosensor for monitoring transducing aptamer-protein recognition events, based on charge distribution under the applied frequency by non-Faradaic impedance spectroscopy (NFIS). This approach to capacitive biosensors is reported for the first time in this study, is reagent-less in processing and is developed using gold interdigitated (GID) capacitor arrays functionalized with synthetic RNA aptamers. The RNA atpamers served as biorecognition elements for C-reactive protein (CRP), a biomarker for cardiovascular disease risk (CVR). The signal is generated as a result of the change in relative capacitance occurring as a result of the formation of an RNA-CRP complex on GID capacitors with the applied AC electrical frequency (50-350 MHz). The dispersion peak of the capacitance curve was dependent on the CRP concentration and tends to shift toward lower frequencies, accompanied by the increase in relaxation time due to the increased size of the aptamer-CRP complex. The dissociation constant (K(d)) calculated from the non-linear regression analysis of the relative capacitance change with the applied frequency showed that strong binding of CRP occurred at 208 MHz (K(d) = 1.6 microM) followed by 150 MHz (K(d) = 4.2 microM) and 306 MHz (K(d) = 3.4 microM) frequencies. The dynamic detection range for CRP is determined to be within 100-500 pg ml(-1). Our results demonstrates the behavior of an RNA-protein complex on GID capacitors under an applied electric field, which can be extended to other pairs of affinity biomolecules as well as for the development of electrical biosensor systems for different applications, including the early diagnosis of diseases.

  3. Novel capacitance-type humidity sensor based on multi-wall carbon nanotube/SiO2 composite films

    Institute of Scientific and Technical Information of China (English)

    Liu Xiaowei; Zhao Zhengang; Li Tuo; Wang Xin

    2011-01-01

    A novel capacitance-type relative humidity (RH) sensor based on multi-wall carbon nanotubc/SiO2 (MWCNTs/SiO2) composite film is reported.Details of the fabrication process,possible sensing mechanism and sensing characteristics,such as linearity and sensitivity,are described.The capacitance of the MWCNTs/SiO2 composite film shows typical concentration percolation behavior with increasing MWCNT loading.At loadings below the percolation threshold (1.842wt%),the sensor capacitance increases obviously with increasing MWCNTs.The water condensed in the MWCNTs/SiO2 layer can lower the percolation threshold and increase the sensor capacitance.The sensor with MWCNT concentration of 1 wt% has the best properties.The sensor has a humidity sensitivity of about 673 pF/% RH and a linearity correlation of 0.98428.The response time of the sensor to RH is about 40 s and the recovery time is about 2 s.

  4. Chemical vapor detection using a capacitive micromachined ultrasonic transducer.

    Science.gov (United States)

    Lee, Hyunjoo J; Park, Kwan Kyu; Kupnik, Mario; Oralkan, O; Khuri-Yakub, Butrus T

    2011-12-15

    Distributed sensing of gas-phase chemicals using highly sensitive and inexpensive sensors is of great interest for many defense and consumer applications. In this paper we present ppb-level detection of dimethyl methylphosphonate (DMMP), a common simulant for sarin gas, with a ppt-level resolution using an improved capacitive micromachined ultrasonic transducer (CMUT) as a resonant chemical sensor. The improved CMUT operates at a higher resonant frequency of 47.7 MHz and offers an improved mass sensitivity of 48.8 zg/Hz/μm(2) by a factor of 2.7 compared to the previous CMUT sensors developed. A low-noise oscillator using the CMUT resonant sensor as the frequency-selective device was developed for real-time sensing, which exhibits an Allan deviation of 1.65 Hz (3σ) in the presence of a gas flow; this translates into a mass resolution of 80.5 zg/μm(2). The CMUT resonant sensor is functionalized with a 50-nm thick DKAP polymer developed at Sandia National Laboratory for dimethyl methylphosphonate (DMMP) detection. To demonstrate ppb-level detection of the improved chemical sensor system, the sensor performance was tested at a certified lab (MIT Lincoln Laboratory), which is equipped with an experimental chemical setup that reliably and accurately delivers a wide range of low concentrations down to 10 ppb. We report a high volume sensitivity of 34.5 ± 0.79 pptv/Hz to DMMP and a good selectivity of the polymer to DMMP with respect to dodecane and 1-octanol.

  5. Mirror imaging of impacted and supernumerary teeth in dizygotic twins: A case report.

    Science.gov (United States)

    Cassetta, Michele; Altieri, Federica; Giordano, Alessandra

    2015-02-01

    Mesiodens is the most common type of supernumerary tooth found in the premaxilla. It might be discovered by the clinical examination by chance on a radiograph or as the cause of an unerupted maxillary central incisor. The genetic transmission of supernumerary and impacted teeth is poorly understood. Mirror imaging in twins has been reported frequently in relation to several unilateral dental anomalies including mesiodens. This phenomenon is the appearance of an asymmetrical feature or anomaly occurring on the right side of one twin but on the left side of the other twin. The event of mesiodens mirror imaging in monozygotic twins has been described in literature. This is the first reported case of mesiodens mirror images in dizygotic twins. The de-scribed mesiodens caused the eruption failure of maxillary permanent incisors. The super-numerary teeth were removed to facilitate the spontaneous eruption of the impacted perma-nent maxillary incisors. Studies related to supernumerary teeth can be useful to clinicians in the early diagnosis of this anomaly. Clinical and radiographic examinations provide a correct therapeutic approach. Key words:Supernumerary teeth, twins, dental development.

  6. Two-dimensional dopant profiling of gallium nitride p–n junctions by scanning capacitance microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lamhamdi, M. [GREMAN UMR 7347-Université de Tours, 10 Rue Thales de Milet, BP 7155, 37071 Tours (France); Ecole national des sciences appliquées khouribga, Université Hassan 1er, 26000 Settat (Morocco); Cayrel, F. [GREMAN UMR 7347-Université de Tours, 10 Rue Thales de Milet, BP 7155, 37071 Tours (France); Frayssinet, E. [CRHEA-CNRS, Rue Bernard Grégory, Sophia Antipolis, 06560 Valbonne (France); Bazin, A.E.; Yvon, A.; Collard, E. [STMicroelectronics, 16 Rue Pierre et Marie Curie, BP 7155, 37071 Tours (France); Cordier, Y. [CRHEA-CNRS, Rue Bernard Grégory, Sophia Antipolis, 06560 Valbonne (France); Alquier, D. [GREMAN UMR 7347-Université de Tours, 10 Rue Thales de Milet, BP 7155, 37071 Tours (France)

    2016-04-01

    Two-dimensional imaging of dopant profiles for n and p-type regions are relevant for the development of new power semiconductors, especially for gallium nitride (GaN) for which classical profiling techniques are not adapted. This is a challenging task since it needs a technique with simultaneously good sensitivity, high spatial resolution and high dopant gradient resolution. To face these challenges, scanning capacitance microscopy combined with Atomic Force Microscopy is a good candidate, presenting reproducible results, as demonstrated in literature. In this work, we attempt to distinguish reliably and qualitatively the various doping concentrations and type at p–n and unipolar junctions. For both p–n and unipolar junctions three kinds of samples were prepared and measured separately. The space-charge region of the p–n metallurgical junction, giving rise to different contrasts under SCM imaging, is clearly observed, enlightening the interest of the SCM technique.

  7. Rotator cuff disorders: How to write a surgically relevant magnetic resonance imaging report?

    Science.gov (United States)

    Tawfik, Ahmed M; El-Morsy, Ahmad; Badran, Mohamed Aboelnour

    2014-06-28

    Evaluation of rotator cuff is a common indication for magnetic resonance imaging (MRI) scanning of the shoulder. Conventional MRI is the most commonly used technique, while magnetic resonance (MR) arthrography is reserved for certain cases. Rotator cuff disorders are thought to be caused by a combination of internal and external mechanisms. A well-structured MRI report should comment on the relevant anatomic structures including the acromial type and orientation, the presence of os acromiale, acromio-clavicular degenerative spurs and fluid in the subacromial subdeltoid bursa. In addition, specific injuries of the rotator cuff tendons and the condition of the long head of biceps should be accurately reported. The size and extent of tendon tears, tendon retraction and fatty degeneration or atrophy of the muscles are all essential components of a surgically relevant MRI report.

  8. Idiopathic Acute Isolated Lateral Compartment Syndrome of a Lower Leg: A Magnetic Resonance Imaging Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Yeom, Dong Heon; Lee, Ji Hae; Cho, Woo Ho; Kim, Jae Hyung; Jeong, Myeong Ja; Kim, Soung Hee; Kim, Ji Young; Kim, Soo Hyun; Kang, Mi Jin; Lee, Han Bee [Dept. of Radiology, Sanggye Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of); Bae, Kyung Eun [Dept. of Radiology, Seoul Asan Hospital, Ulsan University College of Medicine, Seoul (Korea, Republic of)

    2013-01-15

    Acute compartment syndrome of the lower leg is usually associated with major trauma such as fracture, and most commonly occurs in the anterior or deep posterior compartments. Isolated lateral compartment syndrome is less typical and usually associated with minor trauma or exertion. There are a few reports of the acute compartment syndrome which develops without an obvious cause. However, there are few reports of idiopathic acute isolated lateral compartment syndrome, and there are no reports of the radiologic findings. This study presents a radiologic finding of idiopathic acute isolated lateral compartment of lower leg, which shows localized enlargement of the peroneal muscles with peripheral convex bowing and change of their signal intensity with fluid signal along the adjacent fascial planes on magnetic resonance imaging.

  9. 3D capacitive vibrational micro harvester using isotropic charging of electrets deposited on vertical sidewalls

    Science.gov (United States)

    Nimo, Antwi; Mescheder, Ulrich; Müller, Bernhard; Saad Abou Elkeir, Awad

    2011-06-01

    In this paper the design and fabrication of an integrated micro energy harvester capable of harvesting electrical energy from low amplitude mechanical vibrations is presented. A specific feature of the presented energy harvester is its capability to harvest vibrational energy from different directions (3D). This is done through an innovative approach for electrets placed on vertical sidewalls and thereby allowing for miniaturization of 3D capacitive energy harvester on monolithic CMOS substrates. A new simple electret charging method using ionic hair-dryers/hair ionizers is reported and shown that it can be effectively used for electrets-based micro energy harvesters.

  10. ac electrokinetic micropumps: The effect of geometrical confinement, Faradaic current injection, and nonlinear surface capacitance

    DEFF Research Database (Denmark)

    Olesen, Laurits Højgaard; Bruus, Henrik; Ajdari, A.

    2006-01-01

    Recent experiments have demonstrated that ac electrokinetic micropumps permit integrable, local, and fast pumping (velocities similar to mm/s) with low driving voltage of a few volts only. However, they also displayed many quantitative and qualitative discrepancies with existing theories. We...... therefore extend the latter theories to account for three experimentally relevant effects: (i) vertical confinement of the pumping channel, (ii) Faradaic currents from electrochemical reactions at the electrodes, and (iii) nonlinear surface capacitance of the Debye layer. We report here that these effects...... indeed affect the pump performance in a way that we can rationalize by physical arguments....

  11. A highly elastic, capacitive strain gauge based on percolating nanotube networks.

    Science.gov (United States)

    Cohen, Daniel J; Mitra, Debkishore; Peterson, Kevin; Maharbiz, Michel M

    2012-04-11

    We present a highly elastic strain gauge based on capacitive sensing of parallel, carbon nanotube-based percolation electrodes separated by a dielectric elastomer. The fabrication, relying on vacuum filtration of single-walled carbon nanotubes and hydrophobic patterning of silicone, is both rapid and inexpensive. We demonstrate reliable, linear performance over thousands of cycles at up to 100% strain with less than 3% variability and the highest reported gauge factor for a device of this class (0.99). We further demonstrate use of this sensor in a robotics context to transduce joint angles.

  12. Osteoblastoma of the rib with CT and MR imaging: a case report and literature review

    Directory of Open Access Journals (Sweden)

    Ye Jing

    2012-03-01

    Full Text Available Abstract Osteoblastoma is a rare bone tumor which is mostly found in the vertebral column and long bone. We describe a 59-year-old woman with osteoblastoma in the right fifth posterior segment of the rib, whose presenting symptoms were right back pain for two years and awakened at night. Chest computer tomography (CT and thoracic spine magnetic resonance (MR imaging findings included an expansile lesion of the right fifth rib and an ossified matrix. Surgical resection of the lesion confirmed a benign osteoblastoma. 12 months follow-up revealed disappearance of right back pain. Rib osteoblastoma in plain film has been described previously; however, to our knowledge this is the only case report emphasized in CT and MR imaging.

  13. Computed tomographic and magnetic resonance imaging of ameloblastoma: 2 case reports

    Energy Technology Data Exchange (ETDEWEB)

    Oder, P.; Royster, A. [Boston Medical Center, Dept. of Radiology, Boston, Massachusetts (United States); Gibbons, D. [Boston Medical Center, Dept. of Pathology, Boston, Massachusetts (United States); Mulligan, N.; Kavanagh, P.; Eustace, S. [Boston Medical Center, Dept. of Radiology, Boston, Massachusetts (United States)

    1999-12-01

    Cysts of the mandible are uncommon. Most arise from epithelium lining the alveolus or root of the tooth (tooth derivatives), and the rest arise from the cortical and cancellous osseous matrix of the mandible. Of cysts arising from the alveolus (odontogenic epithelium), radicular cysts are the most common, accounting for almost 90% of cases. They are almost always found either in association with a dental cavity or at the base of a devitalized, amalgam-filled tooth. Of the remaining 10% of cases, most are dentigerous cysts, arising from the outer epithelial lining of the developing tooth, which is displaced to the base of the cyst as the lesion grows. Ameloblastoma, which also arises from odontogenic epithelium, accounts for less than 1% of cases. In this case report, we review the imaging appearance, histology and management of this uncommon tumour. In doing so, we highlight signal characteristics on magnetic resonance imaging (MRI) that may allow noninvasive characterization of ameloblastoma before surgical resection. (author)

  14. Is pre-surgical imaging required for an asymptomatic posterior vertex subcutaneous dermoid? A case report

    Directory of Open Access Journals (Sweden)

    Simon Ho

    2016-09-01

    Full Text Available Scalp dermoid cysts are common etiologies of subcutaneous lump and bump lesions in the pediatric population, with incidence ranging from 15 to 22% (Crawford, 1990; McAvoy & Zuckerbraun, 1976. Midline scalp dermoid cysts have high risk for intracranial extension, with incidence reported to be 39–57% of cases (Wood, Couture, & David, 2012; Posnick, Bortoluzzi, Armstrong, & Drake, 1994. The following case illustrates a healthy thirteen-year-old boy who presented with asymptomatic enlarging subcutaneous posterior scalp mass who was consented for excision of the mass without pre-operative imaging, and was found to have an intracranial dermoid sinus tract intra-operatively. Post-operative imaging found an intracranial dermoid nodule which entailed an otherwise avoidable second-stage surgery to achieve complete resection.

  15. Transverse testicular ectopia diagnosed by US and MR imaging: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Hye Sun; Kim, Yong Woo; Choi, Seok Jin; Cha, Seong Sook [Inje University, Busan Paik Hospital, Busan (Korea, Republic of)

    2007-01-15

    Transverse testicular ectopia (TTE) is a rare congenital anomaly in which both testes migrate toward the same hemiscrotum. In most cases, the correct diagnosis is not made preoperatively, but it's made during an inguinal herniotomy or during surgical exploration for an undescended testis because TTE is clinically misdiagnosed as an symptomatic inguinal hernia or as a tumor of the testis on the side to which the ectopic testis has migrated or as an undescended testis on the contralateral side. US and MR imaging can detect the transverse testicular ectopia by its characteristic appearance and so provide useful information about any associated anomalies. We report here on a case of transverse testicular ectopia that was diagnosed by US and MR imaging in a 10-month-old boy, and we review the relevant literature.

  16. The report of the investigation concerning the image quality and dose of digital mammography

    Energy Technology Data Exchange (ETDEWEB)

    Takeshita, Masanori [Osaka Prefectural Center for Adult Diseases (Japan); Kuma, Koji [Kagoshima Municipal Hospital (Japan); Takekawa, Naoya [Osaka Kosei-Nenkin Hospital (Japan); Tanaka, Isamu [Hakuaikai Hospital, Fukuoka (Japan); Tanaka, Atsushi [Osaka Police Hospital (Japan); Hatada, Toshikazu [Kitakyushu Municipal Medical Center, Fukuoka (Japan); Higashida, Yoshiharu [Kyushu Univ., Fukuoka (Japan). Faculty of Medicine

    2002-11-01

    For the sake of good quality control (QC) of mammography by computed radiography (CR) using the imaging plate (IP), the investigation in the title was conducted on 43 and 47 facilities in Kyushu and Kinki areas, respectively. Those facilities were using Fuji CR system of 6 kinds of CR apparatus and 3 sorts of IP. Experimental equipments were QC phantoms of RMI-156 and 165, fluoro-glass dosimeter GD 403 and mdh dosimeter for mammography, which were previously sent to the facilities. Data concerning the mean dose of mammary gland, concentration of the phantom center, and contrast and particle characteristics of images were sent back to the working investigators and analyzed in this report. Comparison of the CR method with the film method was presented. (K.H.)

  17. Report on the Imaging Workshop for the Genomes to Life Program, April 16-18, 2002

    Energy Technology Data Exchange (ETDEWEB)

    Colson, STEVEN

    2003-08-04

    This report is a result of the Imaging Workshop for the Genomes to Life (GTL) program held April 16-19, 2002, in Charlotte, North Carolina. The meeting was sponsored by the Office of Biological and Environmental Research and the Office of Advanced Scientific Computing Research of the U.S. Department of Energy's (DOE) Office of Science. The purpose of the workshop was to project a broad vision for future needs and determine the value of imaging to GTL program research. The workshop included four technical sessions with plenary lectures on biology and technology perspectives and technical presentations on needs and approaches as they related to the following areas of the GTL program: (1) Molecular machines (protein complexes); (2) Intracellular and cellular structure, function, and processes; (3) Multicellular: Monoclonal and heterogeneous multicellular systems, cell-cell signaling, and model systems; and (4) Cells in situ and in vivo: Bacteria in the natural environment, microenvironment, and in vivo systems.

  18. Experimental Evaluation of the Applicability of Capacitive and Optical Measurement Methods for the Determination of Liquid Hydrogen Volume Flow

    Directory of Open Access Journals (Sweden)

    Gert HOLLER

    2009-08-01

    Full Text Available This paper presents a capacitive and a vision-based method for measuring the velocity of cryogenic hydrogen flows. The capacitive sensing principle exploits the spatial frequency signature of perturbations moving through a multi-electrode structure. This setup increases the sensitivity to dielectric permittivity variations compared to a simple two-electrode structure while preserving the ability to detect small perturbations. The vision-based method relies on a high-speed camera system that monitors the liquid hydrogen flow through an optical window yielding the flow velocity by cross-correlating subsequent images of the flow. Although a comprehensive analysis of the obtainable measurement uncertainty was not performed yet, current measurement results show the applicability of both principles for the non-invasive measurement of the volume flow of cryogenic fuels inside conveyor pipes.

  19. Finite-element simulations of coupling capacitances in capacitively coupled pixel detectors

    CERN Document Server

    AUTHOR|(SzGeCERN)755510

    2017-01-01

    Capacitively coupled hybrid silicon pixel-detector assemblies are under study for the vertex detector at the proposed future CLIC linear electron-positron collider. The assemblies consist of active CCPDv3 sensors, with 25 μm pixel pitch implemented in a 180 nm High- Voltage CMOS process, which are glued to the CLICpix readout ASIC, with the same pixel pitch and processed in a commercial 65 nm CMOS technology. The signal created in the silicon bulk of the active sensors passes a two-stage amplifier, in each pixel, and gets transferred as a voltage pulse to metal pads facing the readout chip (ROC). The coupling of the signal to the metal pads on the ROC side proceeds through the capacitors formed between the two chips by a thin layer of epoxy glue. The coupling strength and the amount of unwanted cross coupling to neighbouring pixels depends critically on the uniformity of the glue layer, its thickness and on the alignment precision during the flip-chip assembly process. Finite-element calculations of the coup...

  20. Performance analysis of a digital capacitance measuring circuit.

    Science.gov (United States)

    Xu, Lijun; Sun, Shijie; Cao, Zhang; Yang, Wuqiang

    2015-05-01

    This paper presents the design and study of a digital capacitance measuring circuit with theoretical analysis, numerical simulation, and experimental evaluation. The static and dynamic performances of the capacitance measuring circuit are first defined, including signal-to-noise ratio (SNR), standard deviation, accuracy, linearity, sensitivity, and response time, within a given measurement range. Then numerical simulation is carried out to analyze the SNR and standard deviation of the circuit, followed by experiments to validate the overall performance of the circuit. The simulation results show that when the standard deviation of noise is 0.08 mV and the measured capacitance decreases from 6 pF to 3 fF, the SNR decreases from 90 dB to 22 dB and the standard deviation is between 0.17 fF and 0.24 fF. The experimental results show that when the measured capacitance decreases from 6 pF to 40 fF and the data sampled in a single period are used for demodulation, the SNR decreases from 88 dB to 40 dB and the standard deviation is between 0.18 fF and 0.25 fF. The maximum absolute error and relative error are 5.12 fF and 1.26%, respectively. The SNR and standard deviation can be further improved if the data sampled in more than one period are used for demodulation by the circuit.

  1. Capacitive technology for energy extraction from chemical potential differences

    NARCIS (Netherlands)

    Bastos Sales, B.

    2013-01-01

    This thesis introduces the principle of Capacitive energy extraction based on Donnan Potential (CDP) to exploit salinity gradients. It also shows the fundamental characterization and improvements of CDP. An alternative application of this technology aimed at thermal gradients was tested.  

  2. An Approximation Algorithm for the Capacitated Arc Routing Problem

    DEFF Research Database (Denmark)

    Wøhlk, Sanne

    2008-01-01

    In this paper we consider approximation of the Capacitated Arc Routing Problem, which is the problem of servicing a set of edges in a graph using a fleet of capacity constrained vehicles. We present a 7/2 - 3/W-approximation algorithm for the problem and prove that this algorithm outperforms...

  3. Production of pulsed electric fields using capacitively coupled electrodes

    Science.gov (United States)

    Kendall, B. R. F.; Schwab, F. A. S.

    1980-01-01

    It is shown that pulsed electric fields can be produced over extended volumes by taking advantage of the internal capacitances in a stacked array of electrodes. The design, construction, and performance of practical arrays are discussed. The prototype arrays involved fields of 100-1000 V/cm extending over several centimeters. Scaling to larger physical dimensions is straightforward.

  4. Simple and economical capacitive displacement system for UHV operation.

    Science.gov (United States)

    Chow, R; Tiller, W A

    1979-12-01

    A parallel plate capacitor was assembled as a displacement transducer for operation in an UHV environment. The capacitive displacement system was linear over a 2.5 mum range with a resolution of 0.051 mum. Components in the electric circuit were common laboratory instruments.

  5. 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.

  6. Water Desalination Using Capacitive Deionization with Microporous Carbon Electrodes

    NARCIS (Netherlands)

    Porada, S.; Weinstein, L.; Dash, R.; Wal, van der A.F.; Bryjak, M.; Gogotsi, Y.; Biesheuvel, P.M.

    2012-01-01

    Capacitive deionization (CDI) is a water desalination technology in which salt ions are removed from brackish water by flowing through a spacer channel with porous electrodes on each side. Upon applying a voltage difference between the two electrodes, cations move to and are accumulated in electrost

  7. Optimization of salt adsorption rate in membrane capacitive deionization

    NARCIS (Netherlands)

    Zhao, R.; Satpradit, O.A.; Rijnaarts, H.; Biesheuvel, P.M.; Wal, van der A.

    2013-01-01

    Membrane capacitive deionization (MCDI) is a water desalination technique based on applying a cell voltage between two oppositely placed porous electrodes sandwiching a spacer channel that transports the water to be desalinated. In MCDI, ion-exchange membranes are positioned in front of each porous

  8. Topology Optimization of Stressed Capacitive RF MEMS Switches

    DEFF Research Database (Denmark)

    Philippine, Mandy A.; Sigmund, Ole; Rebeiz, Gabriel M.

    2013-01-01

    Geometry design can improve a capacitive radio-frequency microelectromechanical system switch's reliability by reducing the impacts of intrinsic biaxial stresses and stress gradients on the switch's membrane. Intrinsic biaxial stresses cause stress stiffening, whereas stress gradients cause out-o...

  9. Characterization of dielectric charging in RF MEMS capacitive switches

    NARCIS (Netherlands)

    Herfst, R.W.; Huizing, H.G.A.; Steeneken, P.G.; Schmitz, Jurriaan

    2006-01-01

    RF MEMS capacitive switches show great promise for use in wireless communication devices such as mobile phones, but the successful application of these switches is hindered by reliability concerns: charge injection in the dielectric layer (SiN) can cause irreversible stiction of the moving part of

  10. Microfluidic desalination. Capacitive deionization on chip for microfluidic sample preparation

    NARCIS (Netherlands)

    Roelofs, Susan Helena

    2015-01-01

    The main aim of the work described in this thesis is to implement the desalination technique capacitive deionization (CDI) on a microfluidic chip to improve the reproducibility in the analysis of biological samples for drug development. Secondly, microfluidic CDI allows for the in situ study of ion

  11. Resistance identification and rational process design in Capacitive Deionization

    NARCIS (Netherlands)

    Dijkstra, J.E.; Zhao, R.; Biesheuvel, P.M.; Wal, van der A.

    2016-01-01

    Capacitive Deionization (CDI) is an electrochemical method for water desalination employing porous carbon electrodes. To enhance the performance of CDI, identification of electronic and ionic resistances in the CDI cell is important. In this work, we outline a method to identify these resistances. W

  12. Capacitive pressure sensor in post-processing on LTCC substrates

    NARCIS (Netherlands)

    Meijerink, M.G.H.; Nieuwkoop, E.; Veninga, E.P.; Meuwissen, M.H.H.; Tijdink, M.W.W.J.

    2005-01-01

    A capacitive pressure sensor was realized by means of a post-processing step on a low temperature co-fired ceramics (LTCC) substrate. The new sensor fabrication technology allows for integration of the sensor with interface circuitry and possibly also wireless transmission circuits on LTCC substrate

  13. Carbon nanotube yarns as strong flexible conductive capacitive electrodes

    NARCIS (Netherlands)

    Liu, F.; Wagterveld, R.M.; Gebben, B.; Otto, M.J.; Biesheuvel, P.M.; Hamelers, H.V.M.

    2015-01-01

    Carbon nanotube (CNT) yarn, consisting of 23 µm diameter CNT filaments, can be used as capacitive electrodes that are long, flexible, conductive and strong, for applications in energy and electrochemical water treatment. We measure the charge storage capacity as function of salt concentration, and u

  14. 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.

  15. A micro dynamically tuned gyroscope with adjustable static capacitance.

    Science.gov (United States)

    Xia, Dunzhu; Yu, Cheng; Kong, Lun

    2013-02-06

    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.

  16. An organic integrated capacitive DC-DC up-converter

    NARCIS (Netherlands)

    Marien, H.; Steyaert, M.; Steudel, S.; Vicca, P.; Smout, S.; Gelinck, G.H.; Heremans, P.L.

    2010-01-01

    In this paper a fully integrated organic DC-DC upconverter is presented in a pentacene p-type only technology. This 3-stage Dickson converter reaches a voltage conversion factor of 3 for a purely capacitive load and 2.5 for a 10 μA load current. The maximal output voltage goes up to 75 V and the Dic

  17. RF-MEMS capacitive switches with high reliability

    Science.gov (United States)

    Goldsmith, Charles L.; Auciello, Orlando H.; Carlisle, John A.; Sampath, Suresh; Sumant, Anirudha V.; Carpick, Robert W.; Hwang, James; Mancini, Derrick C.; Gudeman, Chris

    2013-09-03

    A reliable long life RF-MEMS capacitive switch is provided with a dielectric layer comprising a "fast discharge diamond dielectric layer" and enabling rapid switch recovery, dielectric layer charging and discharging that is efficient and effective to enable RF-MEMS switch operation to greater than or equal to 100 billion cycles.

  18. Energy consumption and constant current operation in membrane capacitive deionization

    NARCIS (Netherlands)

    Zhao, R.; Biesheuvel, P.M.; Wal, van der A.F.

    2012-01-01

    Membrane capacitive deionization (MCDI) is a water desalination technology based on applying a cell voltage between two oppositely placed porous electrodes sandwiching a spacer channel that transports the water to be desalinated. In the salt removal step, ions are adsorbed at the carbon–water interf

  19. Micro coriolis mass flow sensor with integrated capacitive readout

    NARCIS (Netherlands)

    Haneveld, J.; Lammerink, T.S.J.; Boer, de M.J.; Wiegerink, R.J.

    2009-01-01

    We have realized a micromachined micro Coriolis mass flow sensor with integrated capacitive readout to detect the extremely small Coriolis vibration of the sensor tube. A special comb-like detection electrode design eliminates the need for multiple metal layers and sacrificial layer etching methods.

  20. A Multifunction Low-Power Preamplifier for MEMS Capacitive Microphones

    DEFF Research Database (Denmark)

    Jawed, Syed Arsalan; Nielsen, Jannik Hammel; Gottardi, Massimo;

    2009-01-01

    A multi-function two-stage chopper-stabilized preamplifier (PAMP) for MEMS capacitive microphones (MCM) is presented. The PAMP integrates digitally controllable gain, high-pass filtering and offset control, adding flexibility to the front-end readout of MCMs. The first stage of the PAMP consists...

  1. Waterproof, Ultrahigh Areal-Capacitance, Wearable Supercapacitor Fabrics.

    Science.gov (United States)

    Yang, Yu; Huang, Qiyao; Niu, Liyong; Wang, Dongrui; Yan, Casey; She, Yiyi; Zheng, Zijian

    2017-02-24

    High-performance supercapacitors (SCs) are promising energy storage devices to meet the pressing demand for future wearable applications. Because the surface area of a human body is limited to 2 m(2) , the key challenge in this field is how to realize a high areal capacitance for SCs, while achieving rapid charging, good capacitive retention, flexibility, and waterproofing. To address this challenge, low-cost materials are used including multiwall carbon nanotube (MWCNT), reduced graphene oxide (RGO), and metallic textiles to fabricate composite fabric electrodes, in which MWCNT and RGO are alternatively vacuum-filtrated directly onto Ni-coated cotton fabrics. The composite fabric electrodes display typical electrical double layer capacitor behavior, and reach an ultrahigh areal capacitance up to 6.2 F cm(-2) at a high areal current density of 20 mA cm(-2) . All-solid-state fabric-type SC devices made with the composite fabric electrodes and water-repellent treatment can reach record-breaking performance of 2.7 F cm(-2) at 20 mA cm(-2) at the first charge-discharge cycle, 3.2 F cm(-2) after 10 000 charge-discharge cycles, zero capacitive decay after 10 000 bending tests, and 10 h continuous underwater operation. The SC devices are easy to assemble into tandem structures and integrate into garments by simple sewing.

  2. Dynamic Adsorption/Desorption Process Model of Capacitive Deionization

    NARCIS (Netherlands)

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

    2009-01-01

    In capacitive deionization (CDI), an electrical potential difference is applied across oppositely placed electrodes, resulting in the adsorption of ions from aqueous solution and a partially ion-depleted product stream. CDI is a dynamic process which operates in a sequential mode; i.e., after a cert

  3. Capacitive sensor probe to assess frying oil degradation

    Directory of Open Access Journals (Sweden)

    Alfadhl Yahya Khaled

    2015-09-01

    Full Text Available The repeated usage of frying oil has been proven hazardous due to the degradation process by chemical reactions that lead to changes in the quality of the oil. Currently, the degree of frying oil degradation is indicated by the percentage of its total polar compounds (TPC. In this study, a capacitive sensor was designed to assess frying oil degradation at several heating time intervals by measuring changes on its electrical capacitance. The sensor was designed using interdigitated electrode structure. A total of 30 samples of 130 ml palm oil were heated at 180 °C up to 30 h. For each one hour interval, one sample was moved out from the laboratory oven. The electrical capacitance, total polar compound (TPC and viscosity of the samples were measured for analysis. Preliminary results demonstrated significant correlation between oil electrical capacitance with TPC and viscosity with R2 ranged from 0.83 to 0.90. The designed sensor has good potential for simple and inexpensive way of determining frying oil quality.

  4. Multilevel inverter based class D audio amplifier for capacitive transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    The reduced semiconductor voltage stress makes the multilevel inverters especially interesting, when driving capacitive transducers for audio applications. A ± 300 V flying capacitor class D audio amplifier driving a 100 nF load in the midrange region of 0.1-3.5 kHz with Total Harmonic Distortion...

  5. Parasitic capacitance characteristics of deep submicrometre grooved gate MOSFETs

    Science.gov (United States)

    Sreelal, S.; Lau, C. K.; Samudra, G. S.

    2002-03-01

    Grooved gate metal-oxide-semiconductor field-effect transistors (MOSFETs) are known to alleviate many of the short channel and hot carrier effects that arise when MOSFET devices are scaled down to very short channel lengths. However, they exhibit much higher parasitic capacitance with stronger bias dependence when compared to conventional planar devices. In this paper, we present a model for gate-to-drain and gate-to-source capacitance characteristics of a deep submicrometre grooved gate MOSFET. Both the intrinsic and extrinsic parts of the capacitance are modelled separately. In particular, the model presents a novel but simple way to account for the accumulation layer formation in the source/drain region of MOSFETs due to the application of the gate voltage. The results are compared with those obtained from a two-dimensional device simulator. The close match between the modelled and simulated data establishes the validity of the model. The model is then used to account for the superiority of capacitance characteristics of planar device structures and to arrive at optimization guidelines for grooved gate devices to match these characteristics.

  6. Interpretation and Diplomacy Aspects of Authority and Care in Imaging Reports.

    Science.gov (United States)

    Golder, Werner A

    2017-08-14

    Whereas the creativity and intellectual power of the radiologist are measured against his/her written report, the value of the message will not only be judged by the precision of the medical statement. The same result can be attributed to different words. Numerous common and accidental factors exert influence on the decision on what is said and what is not said, how it is assessed and what is ignored. The less certain a diagnosis is and the less favourable its possible consequences are, the more subtleties and periphrases are to be expected within the report. The decision on the nature and the volume of the written report will not only be taken by the time of recording, but is likewise prepared by the knowledge of the patient's history and symptoms, the personal relationship to him/her as well as by a set of conditions throughout the inspection of the images. The intuition that accompanies the information transfer in imaging diagnostics does not only explain the differences in volume and depth of diagnosis and differential diagnosis, but also the range of diagnostic and therapeutic recommendations.

  7. Deep-Hole Inner Diameter Measuring System Based on Non-contact Capacitance Sensor

    Institute of Scientific and Technical Information of China (English)

    于永新; 张恒; 王宗超; 常以哲

    2010-01-01

    A precise aperture measuring system of small deep holes with capacitance sensors is presented. Based on the working principle of non-contact capacitance sensors, influence of the edge effect of gauge head is studied, and one capacitance sensor for measuring the aperture of the small blind holes or through holes is introduced. The system is composed of one positioning device, one aperture measuring capacitance sensor, one measuring circuit, and software. This system employs visual CCD and two-dimensional mic...

  8. Nylon-Graphene Composite Nonwovens as Monolithic Conductive or Capacitive Fabrics.

    Science.gov (United States)

    Pan, Qin; Shim, Eunkyoung; Pourdeyhimi, Behnam; Gao, Wei

    2017-03-08

    Here we describe a nylon-graphene nonwoven (NGN) composite, prepared via melt-blowing of nylon-6 into nonwoven fabrics and infiltrate those with graphene oxide (GO) in aqueous dispersions, which were further chemically reduced into graphene to offer electrical conductivity. The correlation between the conductivity and the graphene loading is described by the percolation scaling law σ = (p - pc)(t), with an exponent t of 1.2 and a critical concentration pc of 0.005 wt %, the lowest among all the nylon composites reported. Monolithic supercapacitors have been further developed on the nylon-GO nonwoven composites (NGO), via a programed CO2-laser patterning process. The nylon nonwoven works as an efficient matrix, providing high capacity to GO and ensuring enough electrode materials generated via the subsequent laser patterning processes. Our best monolithic supercapacitors exhibited an areal capacitance of 10.37 mF cm(-2) in PVA-H2SO4 electrolyte, much higher than the 1-3 mF cm(-2) reported for typical microsupercapacitors. Moreover, our supercapacitors were able to retain a capacitance density of 5.07 mF cm(-2) at an ultrahigh scan rate (1 V s(-1)), probably due to the facilitated ion migration within the highly porous nonwoven framework. This is the first report of highly functional nylon-6 nonwovens, fabricated via industrially scalable pathways into low-cost conductive polymer matrices and disposable energy storage systems.

  9. Radiologic Imaging Findings of Bilateral Infiltrating Pseudoangiomatous Stromal Hyperplasia of the Breasts:A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Go, Hee Sun; Jeh, Su Kyung [Dept. of Radiology, Kangnam Sacred Heart Hospital, College of Medicine, Hallym University, Seoul (Korea, Republic of)

    2013-04-15

    Pseudoangiomatous stromal hyperplasia (PASH), a rare benign lesion, shows the proliferation of the breast stromal tissue mimicking the low grade angiosarcoma (1-7). The most common mammographic and ultrasound finding of PASH is a circumscribed mass without calcification and it is difficult to distinguish from the phyllodes tumor and fibroadenoma (1-4, 8). Up to our knowledge, PASH presenting as rapid bilateral breast enlargement, as seen in our case, is very rare. In addition, several English medical literature were reported in this kind of manifestation of PASH (3, 4, 8). We described imaging findings of diffuse, infiltrating, and bilateral manifectation of PASH.

  10. Influence of Arm Movement on Lesion Detection in PET/CT Imaging: Case Report

    Directory of Open Access Journals (Sweden)

    Yasemin Parlak

    2015-06-01

    Full Text Available Arm movement after the CT scan is a common artifact in PET/CT scanning. Motion artifacts may lead to difficulties in interpreting PET/CT images accurately. We report a 66 year old male patient with gastric cancer who underwent PET/CT for primary staging. He had a previous history of papillary thyroid cancer. In PET scan, there were striking cold artifacts at the level of arms. This is a classical sign of an accidental arm motion. A second scan was performed with the arms down due to the history of papillary thyroid cancer. The results were discussed.

  11. Primary melanoma of the breast: A case report with imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Yeom, Yoo Kyung; Cha, Joo Hee; Kim, Hak Hee; Shin, Hee Jung; Chae, Eun Young; Choi, Woo Jung; Song, In Hye [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2015-11-15

    Primary breast melanoma is extremely rare, and as such, there are no established radiologic findings in the literature. This report describes a case of primary malignant melanoma with mammography, ultrasonography, and magnetic resonance imaging findings. Our case study demonstrates a well-circumscribed heterogeneous rim-enhancing mass, with an internal cystic or necrotic portion seen using three modalities. Thus, although rare, this condition should be included in the differential diagnosis of a well-demarcated heterogeneous breast mass, and further pathological confirmation is needed.

  12. Imaging manifestations of von Hippel-Lindau disease: a report of 3 cases

    Institute of Scientific and Technical Information of China (English)

    GONG Jing-shan; XU Jian-min

    2005-01-01

    @@ Von Hippel-Lindau (VHL) disease is an autosomal-dominant hereditary familial neoplasm syndrome characterized by development of a variety of benign and malignant tumors in multiple organ systems, such as the brain, kidney, pancreas, adrenal gland, and epididymis, with a prevalence of one in 39000-53000.1-4 Hallmarks of the condition include retinal angiomas, hemangioblastomas of the cerebellum and the spinal cord, renal cell carcinoma and cysts, and pheochromocytomas. In this article, we report imaging findings in three cases of VHL disease.

  13. Magnetic resonance imaging correlates of bee sting induced multiple organ dysfunction syndrome: A case report

    Institute of Scientific and Technical Information of China (English)

    Sushant; K; Das; Li-Chuan; Zeng; Bing; Li; Xiang-Ke; Niu; Jing-Liang; Wang; Anup; Bhetuwal; Han-Feng; Yang

    2014-01-01

    Occasionally systemic complications with high risk of death,such as multiple organ dysfunction syndrome(MODS),can occur following multiple bee stings.This case study reports a patient who presented with MODS,i.e.,acute kidney injury,hepatic and cardiac dysfunc-tion,after multiple bee stings.The standard clinical findings were then correlated with magnetic resonance imaging(MRI)findings,which demonstrates that MRI may be utilized as a simpler tool to use than other mul-tiple diagnostics.

  14. Internal auditory canal meningocele-perilabyrinthine/translabyrinthine fistula: Case report and imaging.

    Science.gov (United States)

    Truesdale, Carl M; Peterson, Ryan B; Hudgins, Patricia A; Vivas, Esther X

    2016-08-01

    The case of a 17-year-old patient with progressive unilateral sensorineural hearing loss and temporal bone malformations concerning for internal auditory canal meningocele with translabyrinthine/perilabyrinthine cerebrospinal fluid fistula is presented with associated computed tomography and magnetic resonance imaging. As the second reported case of an unruptured internal auditory canal meningocele with translabyrinthine/perilabyrinthine fistula, the case presents several clinically relevant points for otologists, neurotologists, and neuroradiologists. Although rare, it is an additional entity to consider as a cause of unilateral sensorineural hearing loss and may pose a risk for developing meningitis and possible "gushing" of cerebrospinal fluid should surgical intervention be attempted. Laryngoscope, 126:1931-1934, 2016.

  15. Imaging of unilateral adrenal hemorrhages in patients after blunt abdominal trauma: Report of two cases

    Directory of Open Access Journals (Sweden)

    Asli Tanrivermis Sayit

    2017-02-01

    Full Text Available Adrenal hemorrhage following blunt abdominal trauma is extremely rare. Most of the lesions are unilateral and right sided. Although often asymptomatic, life-threatening adrenal insufficiency may develop in the bilateral adrenal gland hemorrhage. Isolated adrenal injuries are very rare. They are often associated with other organ injuries. The mortality rates of patients range from 7% to 32%. In this report, we present the computed tomography and magnetic resonance imaging findings of unilateral adrenal hemorrhages in two patients with a history of fall from a height.

  16. Prenatal diagnosis of choledochal cyst using magnetic resonance imaging: A case report

    Institute of Scientific and Technical Information of China (English)

    Alex Mun-Ching Wong; Yun-Chung Cheung; Yu-Hung Liu; Koon-Kwan Ng; Siu-Cheung Chan; Shu-Hang Ng

    2005-01-01

    Choledochal cysts are congenital anomalies of the biliary ducts, characterized by cystic dilatation of the ducts.Prenatal diagnosis of this anomaly using ultrasonography (US) has been well documented. Magnetic resonance imaging (MRI) has recently become an important complement to US in prenatal diagnosis of fetal anomalies. We herein report a patient in whom at 24 wk' gestation US suggested a right upper quadrant abdominal cyst and in whom at 26 wk' gestation MRI more clearly delineated the cyst and its surrounding structures and suggested a choledochal cyst, which was confirmed at postnatal surgery and histopathology.

  17. Imaging Finding of Malignant Melanoma of Eustachian Tube with Extension to Middle Ear Cavity: Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Km Hong Chul [Dept. of Radiology, Yeungnam University College of Medicine, Daegu (Korea, Republic of); Jang, Han Won [Daekyung Radiologic Clinics, Daegu (Korea, Republic of); Lee, Hui Joong [Dept. of Radiology, Kyungpook National University Hospital, Daegu (Korea, Republic of)

    2012-11-15

    We report a case of malignant melanoma of Eustachian tube with extension to the middle ear cavity and nasopharynx in a 51-year-old woman who presented with right ear fullness. Computed tomography showed a soft tissue mass in the middle ear cavity and caused the widening and eroding of the bony eustachian tube. Magnetic resonance imaging showed well enhancing mass in eustachian tube extending nasopharynx to middle ear cavity. A biopsy of the middle ear cavity mass revealed a malignant amelanotic melanoma.

  18. Imaging Finding of Malignant Melanoma of Eustachian Tube with Extension to Middle Ear Cavity: Case Report

    Science.gov (United States)

    Kim, Hong Chul; Jang, Han Won

    2012-01-01

    We report a case of malignant melanoma of Eustachian tube with extension to the middle ear cavity and nasopharynx in a 51-year-old woman who presented with right ear fullness. Computed tomography showed a soft tissue mass in the middle ear cavity and causedthe widening and eroding of the bony eustachian tube. Magnetic resonance imaging showed well enhancing mass in eustachian tube extending nasopharynx to middle ear cavity. A biopsy of the middle ear cavity mass revealed a malignant amelanotic melanoma. PMID:23118582

  19. Recording intracellular molecular events from the outside: glycosylphosphatidylinositol-anchored avidin as a reporter protein for in vivo imaging.

    NARCIS (Netherlands)

    Lehmann, S.A.; Garayoa, E.G.; Blanc, A.; Keist, R.; Schibli, R.; Rudin, M.

    2011-01-01

    With the emergence of multimodal imaging strategies, genetically encoded reporters that can be flexibly combined with any imaging modality become highly attractive. Here we describe the use of glycosylphosphatidylinositol (GPI)-anchored avidin, an avidin moiety targeted to the extracellular side of

  20. Multimodality Molecular Imaging of Cardiac Cell Transplantation: Part I. Reporter Gene Design, Characterization, and Optical in Vivo Imaging of Bone Marrow Stromal Cells after Myocardial Infarction.

    Science.gov (United States)

    Parashurama, Natesh; Ahn, Byeong-Cheol; Ziv, Keren; Ito, Ken; Paulmurugan, Ramasamy; Willmann, Jürgen K; Chung, Jaehoon; Ikeno, Fumiaki; Swanson, Julia C; Merk, Denis R; Lyons, Jennifer K; Yerushalmi, David; Teramoto, Tomohiko; Kosuge, Hisanori; Dao, Catherine N; Ray, Pritha; Patel, Manishkumar; Chang, Ya-Fang; Mahmoudi, Morteza; Cohen, Jeff Eric; Goldstone, Andrew Brooks; Habte, Frezghi; Bhaumik, Srabani; Yaghoubi, Shahriar; Robbins, Robert C; Dash, Rajesh; Yang, Phillip C; Brinton, Todd J; Yock, Paul G; McConnell, Michael V; Gambhir, Sanjiv S

    2016-09-01

    Purpose To use multimodality reporter-gene imaging to assess the serial survival of marrow stromal cells (MSC) after therapy for myocardial infarction (MI) and to determine if the requisite preclinical imaging end point was met prior to a follow-up large-animal MSC imaging study. Materials and Methods Animal studies were approved by the Institutional Administrative Panel on Laboratory Animal Care. Mice (n = 19) that had experienced MI were injected with bone marrow-derived MSC that expressed a multimodality triple fusion (TF) reporter gene. The TF reporter gene (fluc2-egfp-sr39ttk) consisted of a human promoter, ubiquitin, driving firefly luciferase 2 (fluc2), enhanced green fluorescent protein (egfp), and the sr39tk positron emission tomography reporter gene. Serial bioluminescence imaging of MSC-TF and ex vivo luciferase assays were performed. Correlations were analyzed with the Pearson product-moment correlation, and serial imaging results were analyzed with a mixed-effects regression model. Results Analysis of the MSC-TF after cardiac cell therapy showed significantly lower signal on days 8 and 14 than on day 2 (P = .011 and P = .001, respectively). MSC-TF with MI demonstrated significantly higher signal than MSC-TF without MI at days 4, 8, and 14 (P = .016). Ex vivo luciferase activity assay confirmed the presence of MSC-TF on days 8 and 14 after MI. Conclusion Multimodality reporter-gene imaging was successfully used to assess serial MSC survival after therapy for MI, and it was determined that the requisite preclinical imaging end point, 14 days of MSC survival, was met prior to a follow-up large-animal MSC study. (©) RSNA, 2016 Online supplemental material is available for this article.