WorldWideScience

Sample records for subscale filter elements

  1. Assessment of high-temperature filtering elements

    Energy Technology Data Exchange (ETDEWEB)

    Monica Lupion; Francisco J. Gutierrez Ortiz; Benito Navarrete; Vicente J. Cortes [University of Seville, Seville (Spain). E.T.S. Ingenieros

    2008-07-01

    A complete experimental campaign has been carried out in a hot gas filtration test facility so as to test several filtering elements and configurations, particularly, three different types of bag filters and one ceramic candle. The facility was designed to operate under a wide range of conditions, thus providing an excellent tool for the investigation of hot gas filtration applications for the advanced electrical power generation industry such as IGCC, PFBC or fuel cell technologies. Relevant parameters for the characterization and optimization of the performance of the filters have been studied for a variety of operation conditions such as filtration velocity, particle concentration, pressure and temperature among others. Pressure drop across the filter, cleaning pulse interval, baseline pressure drop, filtration efficiency and durability of the filter have been investigated for each type considered and dependences on parameters have been established. On top of that, optimal operating conditions and cleaning strategies were determined. The tests results show that bag filters are a suitable alternative for the hot gas filtration due to the better performance and the high efficiency observed, which makes them suitable for industrial applications operating under high temperature high pressure conditions considered within the study (200-370{degree}C and 4-7.5 barg respectively). 7 refs., 7 figs., 10 tabs.

  2. Active pixel sensors with substantially planarized color filtering elements

    Science.gov (United States)

    Fossum, Eric R. (Inventor); Kemeny, Sabrina E. (Inventor)

    1999-01-01

    A semiconductor imaging system preferably having an active pixel sensor array compatible with a CMOS fabrication process. Color-filtering elements such as polymer filters and wavelength-converting phosphors can be integrated with the image sensor.

  3. Bessel smoothing filter for spectral-element mesh

    Science.gov (United States)

    Trinh, P. T.; Brossier, R.; Métivier, L.; Virieux, J.; Wellington, P.

    2017-06-01

    Smoothing filters are extremely important tools in seismic imaging and inversion, such as for traveltime tomography, migration and waveform inversion. For efficiency, and as they can be used a number of times during inversion, it is important that these filters can easily incorporate prior information on the geological structure of the investigated medium, through variable coherent lengths and orientation. In this study, we promote the use of the Bessel filter to achieve these purposes. Instead of considering the direct application of the filter, we demonstrate that we can rely on the equation associated with its inverse filter, which amounts to the solution of an elliptic partial differential equation. This enhances the efficiency of the filter application, and also its flexibility. We apply this strategy within a spectral-element-based elastic full waveform inversion framework. Taking advantage of this formulation, we apply the Bessel filter by solving the associated partial differential equation directly on the spectral-element mesh through the standard weak formulation. This avoids cumbersome projection operators between the spectral-element mesh and a regular Cartesian grid, or expensive explicit windowed convolution on the finite-element mesh, which is often used for applying smoothing operators. The associated linear system is solved efficiently through a parallel conjugate gradient algorithm, in which the matrix vector product is factorized and highly optimized with vectorized computation. Significant scaling behaviour is obtained when comparing this strategy with the explicit convolution method. The theoretical numerical complexity of this approach increases linearly with the coherent length, whereas a sublinear relationship is observed practically. Numerical illustrations are provided here for schematic examples, and for a more realistic elastic full waveform inversion gradient smoothing on the SEAM II benchmark model. These examples illustrate well the

  4. Assessment performance of high-temperature filtering elements

    Energy Technology Data Exchange (ETDEWEB)

    Monica Lupion; Francisco J. Gutierrez Ortiz; Benito Navarrete; Vicente J. Cortes [University of Seville, Seville (Spain). E.T.S. Ingenieros

    2010-04-15

    An extensive experimental campaign has been carried out in a hot gas filtration test facility so as to test several filtering elements and configurations, particularly, three different types of bag filters and one ceramic candle. The facility was designed to operate under a wide range of conditions, thus providing an excellent tool for the investigation of hot gas filtration applications for the advanced electrical power generation industry such as IGCC, PFBC or fuel cell technologies. Relevant parameters for the characterisation and optimization of the performance of the filters have been studied for a variety of operating conditions such as filtration velocity, particle concentration, pressure and temperature among others. Pressure drop across the filter, cleaning pulse interval, baseline pressure drop, filtration efficiency and durability of the filter have been investigated for each type considered and dependences on parameters have been established. On top of that, optimal operating conditions and cleaning strategies were determined. The tests results show that bag filters are a suitable alternative for the hot gas filtration due to the better performance and the high efficiency observed, which makes them suitable for industrial applications operating under high temperature high pressure conditions considered within the study (200-370{sup o}C and 4-7.5 barg, respectively). 8 refs., 7 figs., 10 tabs.

  5. International Space Station (ISS) Bacterial Filter Elements (BFEs): Filter Efficiency and Pressure Testing of Returned Units

    Science.gov (United States)

    Green, Robert D.; Agui, Juan H.; Vijayakumar, R.

    2017-01-01

    The air revitalization system aboard the International Space Station (ISS) provides the vital function of maintaining a clean cabin environment for the crew and the hardware. This becomes a serious challenge in pressurized space compartments since no outside air ventilation is possible, and a larger particulate load is imposed on the filtration system due to lack of sedimentation due to the microgravity environment in Low Earth Orbit (LEO). The ISS Environmental Control and Life Support (ECLS) system architecture in the U.S. Segment uses a distributed particulate filtration approach consisting of traditional High-Efficiency Particulate Adsorption (HEPA) media filters deployed at multiple locations in each U.S. Segment module; these filters are referred to as Bacterial Filter Elements, or BFEs. These filters see a replacement interval, as part of maintenance, of 2-5 years dependent on location in the ISS. In this work, we present particulate removal efficiency, pressure drop, and leak test results for a sample set of 8 BFEs returned from the ISS after filter replacement. The results can potentially be utilized by the ISS Program to ascertain whether the present replacement interval can be maintained or extended to balance the on-ground filter inventory with extension of the lifetime of ISS beyond 2024. These results can also provide meaningful guidance for particulate filter designs under consideration for future deep space exploration missions.

  6. Nitinol Embolic Protection Filters: Design Investigation by Finite Element Analysis

    Science.gov (United States)

    Conti, Michele; de Beule, Matthieu; Mortier, Peter; van Loo, Denis; Verdonck, Pascal; Vermassen, Frank; Segers, Patrick; Auricchio, Ferdinando; Verhegghe, Benedict

    2009-08-01

    The widespread acceptance of carotid artery stenting (CAS) to treat carotid artery stenosis and its effectiveness compared with surgical counterpart, carotid endarterectomy (CEA), is still a matter of debate. Transient or permanent neurological deficits may develop in patients undergoing CAS due to distal embolization or hemodynamic changes. Design, development, and usage of embolic protection devices (EPDs), such as embolic protection filters, appear to have a significant impact on the success of CAS. Unfortunately, some drawbacks, such as filtering failure, inability to cross tortuous high-grade stenoses, malpositioning and vessel injury, still remain and require design improvement. Currently, many different designs of such devices are available on the rapidly growing dedicated market. In spite of such a growing commercial interest, there is a significant need for design tools as well as for careful engineering investigations and design analyses of such nitinol devices. The present study aims to investigate the embolic protection filter design by finite element analysis. We first developed a parametrical computer-aided design model of an embolic filter based on micro-CT scans of the Angioguard™ XP (Cordis Endovascular, FL) EPD by means of the open source pyFormex software. Subsequently, we used the finite element method to simulate the deployment of the nitinol filter as it exits the delivery sheath. Comparison of the simulations with micro-CT images of the real device exiting the catheter showed excellent correspondence with our simulations. Finally, we evaluated circumferential basket-vessel wall apposition of a 4 mm size filter in a straight vessel of different sizes and shape. We conclude that the proposed methodology offers a useful tool to evaluate and to compare current or new designs of EPDs. Further simulations will investigate vessel wall apposition in a realistic tortuous anatomy.

  7. Filter Efficiency and Pressure Testing of Returned ISS Bacterial Filter Elements (BFEs)

    Science.gov (United States)

    Green, Robert D.; Agui, Juan H.; Berger, Gordon M.; Vijayakumar, R.; Perry, Jay L.

    2017-01-01

    The air quality control equipment aboard the International Space Station (ISS) and future deep space exploration vehicles provide the vital function of maintaining a clean cabin environment for the crew and the hardware. This becomes a serious challenge in pressurized space compartments since no outside air ventilation is possible, and a larger particulate load is imposed on the filtration system due to lack of sedimentation. The ISS Environmental Control and Life Support (ECLS) system architecture in the U.S. Segment uses a distributed particulate filtration approach consisting of traditional High-Efficiency Particulate Air (HEPA) filters deployed at multiple locations in each U.S. Seg-ment module; these filters are referred to as Bacterial Filter Elements, or BFEs. In our previous work, we presented results of efficiency and pressure drop measurements for a sample set of two returned BFEs with a service life of 2.5 years. In this follow-on work, we present similar efficiency, pressure drop, and leak tests results for a larger sample set of six returned BFEs. The results of this work can aid the ISS Program in managing BFE logistics inventory through the stations planned lifetime as well as provide insight for managing filter element logistics for future exploration missions. These results also can provide meaningful guidance for particulate filter designs under consideration for future deep space exploration missions.

  8. Single Active Element Based Voltage-Mode Multifunction Filter

    Directory of Open Access Journals (Sweden)

    Jitendra Mohan

    2014-01-01

    Full Text Available The paper presents a new voltage-mode multifunction filter. The proposed filter employs single modified fully differential second generation current conveyor (FDCCII, two grounded capacitors, and three resistors. The proposed circuit enjoys the employment of two grounded capacitors (attractive for absorbing shunt parasitic capacitance and ideal for IC implementation. The proposed circuit provides all five generic filter responses (low pass (LP, high pass (HP, band pass (BP, notch (NH, and all pass (AP filter responses simultaneously with single input. The novel proposed filter has low active and passive sensitivities. A number of time domain and frequency domain simulation results depicted through PSPICE using 0.18 µm TSMC process parameters are included to validate the theory. The proposed circuit is expected to enhance the existing knowledge on the subject.

  9. Miniature wideband filter based on coupled-line sections and quasi-lumped element resonator

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Krozer, Viktor; Meincke, Peter

    2007-01-01

    A new design of a wideband bandpass filter is proposed, based on coupled-line sections and quasi-lumped element resonator, taking advantage of the last one to introduce two transmission zeros and suppress a spurious response. The proposed filter demonstrates significantly improved characteristics...

  10. International Space Station (ISS) Bacterial Filter Elements (BFEs): Filter Efficiency and Pressure Drop Testing of Returned Units

    Science.gov (United States)

    Green, Robert D.; Agui, Juan H.; Vijayakumar, R.; Berger, Gordon M.; Perry, Jay L.

    2017-01-01

    The air quality control equipment aboard the International Space Station (ISS) and future deep space exploration vehicles provide the vital function of maintaining a clean cabin environment for the crew and the hardware. This becomes a serious challenge in pressurized space compartments since no outside air ventilation is possible, and a larger particulate load is imposed on the filtration system due to lack of sedimentation. The ISS Environmental Control and Life Support (ECLS) system architecture in the U.S. Segment uses a distributed particulate filtration approach consisting of traditional High-Efficiency Particulate Air (HEPA) filters deployed at multiple locations in each U.S. Seg-ment module; these filters are referred to as Bacterial Filter Elements, or BFEs. In our previous work, we presented results of efficiency and pressure drop measurements for a sample set of two returned BFEs with a service life of 2.5 years. In this follow-on work, we present similar efficiency, pressure drop, and leak tests results for a larger sample set of six returned BFEs. The results of this work can aid the ISS Program in managing BFE logistics inventory through the stations planned lifetime as well as provide insight for managing filter element logistics for future exploration missions. These results also can provide meaningful guidance for particulate filter designs under consideration for future deep space exploration missions.

  11. Improvement of Stopband Performance in Parallel-Coupled Bandpass Filters Using Quasi-Lumped Elements

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Krozer, Viktor; Meincke, Peter

    2008-01-01

    , with adjustable locations of transmission zeros for desired performance. The device is fabricated in standard thick-film manufacturing technology. Based on parallel-coupled line theory, the impedance inverter model for this device is developed. The passband filter centered at 5.5 GHz with a 3 dB relative......This paper is aimed at improving the rejection level as well as overcoming the bandwidth limitations for classical coupled-line filters. A planar microwave coupled-line filter employing a quasi-lumped element resonator considerably improving the stopband characteristics is presented. The proposed...... bandpass filter has a compact footprint, and exhibits good stopband rejection with no repeated passband at twice the center frequency in comparison with the traditional coupled-line filter. By introducing the quasi-lumped element resonator, two transmission zeros at upper and lower stopbands are created...

  12. Supplementary First-Order All-Pass Filters with Two Grounded Passive Elements Using FDCCII

    Directory of Open Access Journals (Sweden)

    K. Pal

    2011-06-01

    Full Text Available In this study, two novel first-order all-pass filters are proposed using only one grounded resistor and one grounded capacitor along with a fully differential current conveyor (FDCCII. There is no element-matching restriction. The presented all-pass filter circuits can be made electronically tunable due to the electronic resistors. Furthermore, the presented circuits enjoy high-input impedance for easy cascadability. The theoretical results are verified with SPICE simulations.

  13. Switched-capacitor elements for VIS-SC-filters with reduced influences of parasitic capacitances

    Science.gov (United States)

    Pandel, J.

    1981-03-01

    A number of switched-capacitor elements for SC-filters based on voltage inverter switches will be described. All of them are insensitive to the main parasitics occurring in MOS integrated circuits, i.e. the parasitic capacitances between the bottom plates of the implemented capacitors and substrate. The reduction of parasitic effects does not lead to an increasing of the very low attenuation sensitivity with respect to element variations when simulating lossless ladder circuits between resistive terminations. Experimental results of a seventh order low-pass filter built with discrete components are in good agreement with theory.

  14. Image search engine with selective filtering and feature-element-based classification

    Science.gov (United States)

    Li, Qing; Zhang, Yujin; Dai, Shengyang

    2001-12-01

    With the growth of Internet and storage capability in recent years, image has become a widespread information format in World Wide Web. However, it has become increasingly harder to search for images of interest, and effective image search engine for the WWW needs to be developed. We propose in this paper a selective filtering process and a novel approach for image classification based on feature element in the image search engine we developed for the WWW. First a selective filtering process is embedded in a general web crawler to filter out the meaningless images with GIF format. Two parameters that can be obtained easily are used in the filtering process. Our classification approach first extract feature elements from images instead of feature vectors. Compared with feature vectors, feature elements can better capture visual meanings of the image according to subjective perception of human beings. Different from traditional image classification method, our classification approach based on feature element doesn't calculate the distance between two vectors in the feature space, while trying to find associations between feature element and class attribute of the image. Experiments are presented to show the efficiency of the proposed approach.

  15. Methodology of water quality index (WQI) development for filtrated water using irradiated basic filter elements

    Science.gov (United States)

    Anuar, Nuraslinda; Muhamad Pauzi, Anas; Abu Bakar, Asyraf Arif

    2017-01-01

    Clean water production can be achieved by using common simple water filtration system that consists of an empty bottle and the filter elements such as cotton/coffee filter, sands, and gravels, which can be easily assembled and used. To reduce the time to get an acceptably clean water using the common water filtration, this paper will discuss on a solution to increase the filtration effectiveness of the filter elements by irradiating gossypium (or commonly known as cotton), and silica oxide which is the main composition material for sand and gravel from various scale based on the Wentworth scale. There were few studies regarding gamma and neutron irradiation of silica based materials that proves that gamma and neutron irradiation introduce defects, hence, we expect that it may lead to the formation of micropores and alter the water filtration effectiveness. It was established that higher amount of irradiation results in higher concentration of defects. This paper will firstly review literatures on the effect of gamma and neutron irradiation effect on filter elements such as sands and papers, and then develops a water quality index (WQI) that reflects the water appearance quality of the filtrated water. The WQI focuses on the physical appearance such as smells and color of the filtered water.

  16. A high-order spatial filter for a cubed-sphere spectral element model

    Science.gov (United States)

    Kang, Hyun-Gyu; Cheong, Hyeong-Bin

    2017-04-01

    A high-order spatial filter is developed for the spectral-element-method dynamical core on the cubed-sphere grid which employs the Gauss-Lobatto Lagrange interpolating polynomials (GLLIP) as orthogonal basis functions. The filter equation is the high-order Helmholtz equation which corresponds to the implicit time-differencing of a diffusion equation employing the high-order Laplacian. The Laplacian operator is discretized within a cell which is a building block of the cubed sphere grid and consists of the Gauss-Lobatto grid. When discretizing a high-order Laplacian, due to the requirement of C0 continuity along the cell boundaries the grid-points in neighboring cells should be used for the target cell: The number of neighboring cells is nearly quadratically proportional to the filter order. Discrete Helmholtz equation yields a huge-sized and highly sparse matrix equation whose size is N*N with N the number of total grid points on the globe. The number of nonzero entries is also almost in quadratic proportion to the filter order. Filtering is accomplished by solving the huge-matrix equation. While requiring a significant computing time, the solution of global matrix provides the filtered field free of discontinuity along the cell boundaries. To achieve the computational efficiency and the accuracy at the same time, the solution of the matrix equation was obtained by only accounting for the finite number of adjacent cells. This is called as a local-domain filter. It was shown that to remove the numerical noise near the grid-scale, inclusion of 5*5 cells for the local-domain filter was found sufficient, giving the same accuracy as that obtained by global domain solution while reducing the computing time to a considerably lower level. The high-order filter was evaluated using the standard test cases including the baroclinic instability of the zonal flow. Results indicated that the filter performs better on the removal of grid-scale numerical noises than the explicit

  17. Second Order Low-Pass and High-Pass Filter Designs Using Method of Synthetic Immitance Elements

    Directory of Open Access Journals (Sweden)

    Pavel Brandstetter

    2013-01-01

    Full Text Available The paper briefly describes the basics of frequency filter design method using synthetic immittance elements with current conveyors. An introduction of the paper explains the advantages and also disadvantages of using this method. Other chapters briefly introduce a design process of simple second order low-pass and high-pass filter. A theory of current conveyors is discussed too, because they are the basic building blocs of proposed synthetic element and also active frequency filters. Finally, the particular solutions of low-pass and high-pass filters are given and verified by OrCAD PSpice simulations.

  18. Energy-filtering transmission electron microscopy (EFTEM) in the elemental analysis of pseudoexfoliative material.

    Science.gov (United States)

    Schlötzer-Schrehardt, U; Körtje, K H; Erb, C

    2001-02-01

    To obtain more information on the basic nature of the pathological matrix product accumulating in pseudoexfoliation (PEX) syndrome by analyzing its elemental composition at the subcellular level. Energy-filtering transmission electron microscopy (EFTEM), combining the two microanalytical techniques of electron spectroscopic imaging (ESI) and energy-loss spectroscopy (EELS), were performed on ultrathin sections of lens specimens with PEX syndrome using a transmission electron microscope equipped with an integrated electron energy filter. EFTEM is based on inner shell ionization of elements present in the sample giving rise to characteristic signals in well-defined energy-loss regions. The EEL-spectra, demonstrating the presence of a particular element by its specific electron energy-loss edge, were recorded with an integrated scintillator-photomultiplier-system. ESI generated graphic images of elemental localization in the sections after a process of background correction with an IBAS image analysis program. Energy-dispersive X-ray (EDX) analysis of PEX deposits on hydrated lenses was conducted by variable pressure scanning electron microscopy. The ESI element distribution images of both intracapsular and supracapsular PEX material displayed high signals for nitrogen, sulfur, calcium, chlorine, and zinc in clear association with the PEX fibrils. The corresponding EEL-spectra confirmed the data obtained by ESI and showed the presence of the element-specific energy-loss edges. The presence of these elements in PEX fibrils was further confirmed by EDX analysis. No specific signals were obtained for phosphorus, oxygen, or aluminum. This study demonstrates the presence of nitrogen, sulfur, chlorine, zinc, and calcium both in mature and in aggregating PEX fibrils of the lens capsule. EFTEM proved to be a highly sensitive method for the microanalytical study of biological material with unknown composition, such as PEX material, at the subcellular level.

  19. Spectral element filtering techniques for large eddy simulation with dynamic estimation

    CERN Document Server

    Blackburn, H M

    2003-01-01

    Spectral element methods have previously been successfully applied to direct numerical simulation of turbulent flows with moderate geometrical complexity and low to moderate Reynolds numbers. A natural extension of application is to large eddy simulation of turbulent flows, although there has been little published work in this area. One of the obstacles to such application is the ability to deal successfully with turbulence modelling in the presence of solid walls in arbitrary locations. An appropriate tool with which to tackle the problem is dynamic estimation of turbulence model parameters, but while this has been successfully applied to simulation of turbulent wall-bounded flows, typically in the context of spectral and finite volume methods, there have been no published applications with spectral element methods. Here, we describe approaches based on element-level spectral filtering, couple these with the dynamic procedure, and apply the techniques to large eddy simulation of a prototype wall-bounded turb...

  20. Elemental mapping in achromatic atomic-resolution energy-filtered transmission electron microscopy.

    Science.gov (United States)

    Forbes, B D; Houben, L; Mayer, J; Dunin-Borkowski, R E; Allen, L J

    2014-12-01

    We present atomic-resolution energy-filtered transmission electron microscopy (EFTEM) images obtained with the chromatic-aberration-corrected FEI Titan PICO at the Ernst-Ruska Centre, Jülich, Germany. We find qualitative agreement between experiment and simulation for the background-subtracted EFTEM images of the Ti-L2,3 and O-K edges for a specimen of SrTiO3 oriented down the [110] zone axis. The simulations utilize the transition potential formulation for inelastic scattering, which permits a detailed investigation of contributions to the EFTEM image. We find that energy-filtered images of the Ti-L2,3 and O-K edges are lattice images and that the background-subtracted core-loss maps may not be directly interpretable as elemental maps. Simulations show that this is a result of preservation of elastic contrast, whereby the qualitative details of the image are determined primarily by elastic, coherent scattering. We show that this effect places a constraint on the range of specimen thicknesses which could theoretically yield directly useful elemental maps. In general, interpretation of EFTEM images is ideally accompanied by detailed simulations. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Effects of floral metal accumulation on floral visitor communities: introducing the elemental filter hypothesis.

    Science.gov (United States)

    Meindl, George A; Ashman, Tia-Lynn

    2015-03-01

    • For plant species that occur in heavy-metal-rich soil, floral metal accumulation may produce an "elemental filter" that reduces pollinator visitation rate and species richness and changes pollinator species composition relative to closely related species growing on normal soils. Consequently, metal hyperaccumulation may contribute to pollinator-mediated reproductive isolation between closely related plant species that differ in metal accumulation.• To test these ideas, we characterized plant-pollinator interactions in a sympatric pair of species that differ in metal accumulation (Streptanthus polygaloides, a nickel (Ni) hyperaccumulator, and S. tortuosus, a nonaccumulator). To test the elemental filter hypothesis, we presented arrays of S. polygaloides that were grown in either Ni-treated or control soils to insects at both S. polygaloides and S. tortuosus sites and recorded visitation.• Naturally occurring S. polygaloides hyperaccumulated Ni in anthers and accumulated Ni in nectar, while S. tortuosus did not. Floral visitation rates in natural populations were higher to S. tortuosus than S. polygaloides. In addition, while floral visitor richness was similar, few pollinator taxa were shared between the two plant species. Nickel-treatment of S. polygaloides reduced visits by bees, but only for arrays presented at S. tortuosus sites.• We show that the Ni hyperaccumulator S. polygaloides hosts a distinct floral visitor community, indicating that metal accumulation creates a filter for pollinators, similar to that documented for herbivores. Our study highlights a novel mechanism by which the abiotic environment can alter plant-pollinator interactions, and consequently plant reproduction and speciation. © 2015 Botanical Society of America, Inc.

  2. Elemental mapping in achromatic atomic-resolution energy-filtered transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Forbes, B.D. [School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia); Houben, L. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Gruenberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Mayer, J. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Gruenberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Central Facility for Electron Microscopy, RWTH Aachen University, D-52074 Aachen (Germany); Dunin-Borkowski, R.E. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Gruenberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Allen, L.J., E-mail: lja@unimelb.edu.au [School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia)

    2014-12-15

    We present atomic-resolution energy-filtered transmission electron microscopy (EFTEM) images obtained with the chromatic-aberration-corrected FEI Titan PICO at the Ernst-Ruska Centre, Jülich, Germany. We find qualitative agreement between experiment and simulation for the background-subtracted EFTEM images of the Ti–L{sub 2,3} and O–K edges for a specimen of SrTiO{sub 3} oriented down the [110] zone axis. The simulations utilize the transition potential formulation for inelastic scattering, which permits a detailed investigation of contributions to the EFTEM image. We find that energy-filtered images of the Ti–L{sub 2,3} and O–K edges are lattice images and that the background-subtracted core-loss maps may not be directly interpretable as elemental maps. Simulations show that this is a result of preservation of elastic contrast, whereby the qualitative details of the image are determined primarily by elastic, coherent scattering. We show that this effect places a constraint on the range of specimen thicknesses which could theoretically yield directly useful elemental maps. In general, interpretation of EFTEM images is ideally accompanied by detailed simulations. - Highlights: • Achromatic atomic-resolution EFTEM images were obtained for STO 〈110〉. • Simulations were in qualitative agreement with Ti–L{sub 2,3} and O–K edge maps. • The experimental EFTEM maps are not directly interpretable as elemental maps. • Image intensities are strongly determined by preservation of elastic contrast. • Interpretation of EFTEM images is ideally accompanied by detailed simulations.

  3. An efficient implementation of a high-order filter for a cubed-sphere spectral element model

    Science.gov (United States)

    Kang, Hyun-Gyu; Cheong, Hyeong-Bin

    2017-03-01

    A parallel-scalable, isotropic, scale-selective spatial filter was developed for the cubed-sphere spectral element model on the sphere. The filter equation is a high-order elliptic (Helmholtz) equation based on the spherical Laplacian operator, which is transformed into cubed-sphere local coordinates. The Laplacian operator is discretized on the computational domain, i.e., on each cell, by the spectral element method with Gauss-Lobatto Lagrange interpolating polynomials (GLLIPs) as the orthogonal basis functions. On the global domain, the discrete filter equation yielded a linear system represented by a highly sparse matrix. The density of this matrix increases quadratically (linearly) with the order of GLLIP (order of the filter), and the linear system is solved in only O (Ng) operations, where Ng is the total number of grid points. The solution, obtained by a row reduction method, demonstrated the typical accuracy and convergence rate of the cubed-sphere spectral element method. To achieve computational efficiency on parallel computers, the linear system was treated by an inverse matrix method (a sparse matrix-vector multiplication). The density of the inverse matrix was lowered to only a few times of the original sparse matrix without degrading the accuracy of the solution. For better computational efficiency, a local-domain high-order filter was introduced: The filter equation is applied to multiple cells, and then the central cell was only used to reconstruct the filtered field. The parallel efficiency of applying the inverse matrix method to the global- and local-domain filter was evaluated by the scalability on a distributed-memory parallel computer. The scale-selective performance of the filter was demonstrated on Earth topography. The usefulness of the filter as a hyper-viscosity for the vorticity equation was also demonstrated.

  4. MODELING REFLECTANCE AND TRANSMITTANCE OF QUARTZ-FIBER FILTER SAMPLES CONTAINING ELEMENTAL CARBON PARTICLES: IMPLICATIONS FOR THERMAL/OPTICAL ANALYSIS. (R831086)

    Science.gov (United States)

    A radiative transfer scheme that considers absorption, scattering, and distribution of light-absorbing elemental carbon (EC) particles collected on a quartz-fiber filter was developed to explain simultaneous filter reflectance and transmittance observations prior to and during...

  5. A3 Subscale Diffuser Test Article Design

    Science.gov (United States)

    Saunders, G. P.

    2009-01-01

    This paper gives a detailed description of the design of the A3 Subscale Diffuser Test (SDT) Article Design. The subscale diffuser is a geometrically accurate scale model of the A3 altitude rocket facility. It was designed and built to support the SDT risk mitigation project located at the E3 facility at Stennis Space Center, MS (SSC) supporting the design and construction of the A3 facility at SSC. The subscale test article is outfitted with a large array of instrumentation to support the design verification of the A3 facility. The mechanical design of the subscale diffuser and test instrumentation are described here

  6. Conversion of elemental mercury to the oxidized form in a fabric filter baghouse

    Energy Technology Data Exchange (ETDEWEB)

    McManus, T.J.; Agbede, R.O.; Khosah, R.P. [Advanced Technology Systems, Inc., Monroeville, PA (United States)

    1998-12-31

    The US Department of Energy`s Federal Energy Technology Center (DOE-FETC) has in the last several years funded efforts on identifying a sampling and analytical method to differentiate and quantify the chemical forms of mercury emitted from coal-fired electric utility boilers. DOE-FETC requested Advanced Technology Systems, Inc. (ATS) to develop new methodologies for determining the chemical species of mercury in coal flue gas, either by the modification of existing ones or by the introduction of novel methods. Through the efforts of ATS and others, this goal was attained and demonstrated by the final validation of the Ontario-Hydro Method. Also, in these mercury method comparison studies performed by ATS, conversion of elemental mercury to oxidized mercury in a fabric filter baghouse was observed. Investigation of this type of phenomenon was a step beyond mercury species measurement in that this had an impact on the design of mercury control devices for coal-fired power plants which must be mercury species-specific. Moreover, long and short term transport and deposition into the ecosystem with the resulting human and animal toxicity are the ultimate concerns and are all dependent upon the mercury species involved. Results will be reported from a five day study in which mercury species were measured and identified utilizing the Ontario-Hydro Method at the outlet of a baghouse accepting natural gas flue gas spiked with various mercury species.

  7. Production of porous filter elements from PEUAPM nanocomposites and silver nanoparticles; Producao de elementos filtrantes porosos a partir de nanocompositos de PEUAPM e nanoparticulas de prata

    Energy Technology Data Exchange (ETDEWEB)

    Bizzo, M.A.; Hui, W.S., E-mail: mbizzo@usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Escola Politecnica. Departamento de Engenharia Metalurgica e de Materiais

    2014-07-01

    The production of filter elements for water based in polymers is widespread in the market, but has an undesirable characteristic: they are not efficient and able to retain or eliminate microorganisms at all times. This paper proposes to produce nanocomposite filters with biocidal properties composed of ultra-high molecular weight polyethylene(UHMWPE) and silver nanoparticles, the UHMWPE is responsible for the uniform porous structure of the filters and the silver nanoparticles incorporated on the polymer are responsible for the biocide action. Particulate polymer that presents a different particle size curve was used for sintering the filters. Samples of filter elements obtained in this work were characterized by the techniques of X-ray diffraction, scanning electron microscopy and EDS microanalysis. The results indicated a porosity of approximately 49% in the filter, and the formation of the nanocomposite. key-words: nanocomposites, silver, UHMWPE, filter elements. (author)

  8. Accumulation of Elements in Salix and Other Species Used in Vegetation Filters with Focus on Wood Fuel Quality

    Energy Technology Data Exchange (ETDEWEB)

    Adler, Anneli

    2007-07-01

    Woody or herbaceous perennials used as vegetation filters for treatment of different types of wastes can be suitable for production of solid biofuels when their above ground harvestable biomass yield is sufficiently high and when biomass contains appropriate concentrations of minerals with regard to fuel combustion processes. The concentrations of nitrogen (N), potassium (K) and heavy metals (especially Zn and Cd) in fuel should be low and calcium (Ca) concentrations high to avoid technical problems and environmentally harmful emissions during combustion. Since soil supplementation with essential elements improves biomass yield, a conflict might arise between yield and quality aims. There are various possibilities to influence fuel quality during the growing phase of the life cycle of perennial biomass crops. This study assessed the suitability of two deciduous woody perennials (Salix and Populus) and two summer green herbaceous perennials (Phragmites and Urtica) for phytoremediation in terms of growth and nutrient allocation patterns. Salix and Populus proved suitable as vegetation filters when nutrients were available to plants in near-optimal proportions, but when unbalanced nutrient solutions (wastewater) were applied, stem biomass fraction was strongly reduced. Phragmites was more tolerant to wastewater treatment in terms of plant biomass production and nutrient allocation patterns, so if the N:P ratio of the wastewater is suboptimal, a vegetation filter using Phragmites could be considered. In further studies, a method was developed to determine the proportions of nutrient-rich bark in coppiced Salix, while heavy metal phytoextraction capacity was assessed in two Salix vegetation filters. The relevance of proportion of bark on wood fuel quality and element removal from vegetation filters was also investigated. The concentrations of the elements studied in harvestable Salix shoot biomass were higher, meaning lower wood fuel quality, in plantations where

  9. Microwave Filters

    OpenAIRE

    Zhou, Jiafeng

    2010-01-01

    The general theory of microwave filter design based on lumped-element circuit is described in this chapter. The lowpass prototype filters with Butterworth, Chebyshev and quasielliptic characteristics are synthesized, and the prototype filters are then transformed to bandpass filters by lowpass to bandpass frequency mapping. By using immitance inverters ( J - or K -inverters), the bandpass filters can be realized by the same type of resonators. One design example is given to verify the theory ...

  10. Subscale Test Program for the Orion Conical Ribbon Drogue Parachute

    Science.gov (United States)

    Sengupta, Anita; Stuart, Phil; Machin, Ricardo; Bourland, Gary; Schwing, Allen; Longmire, Ellen; Henning, Elsa; Sinclair, Rob

    2011-01-01

    A subscale wind tunnel test program for Orion's conical ribbon drogue parachute is under development. The desired goals of the program are to quantify aerodynamic performance of the parachute in the wake of the entry vehicle, including understanding of the coupling of the parachute and command module dynamics, and an improved understanding of the load distribution within the textile elements of the parachute. The test program is ten percent of full scale conducted in a 3x2.1 m (10x7 ft) closed loop subsonic wind tunnel. The subscale test program is uniquely suited to probing the aerodynamic and structural environment in both a quantitative and qualitative manner. Non-intrusive diagnostics, including Particle Image Velocimetry for wake velocity surveys, high speed pressure transducers for canopy pressure distribution, and a high speed photogrammetric reconstruction, will be used to quantify the parachute's performance.

  11. Atomic resolution elemental mapping using energy-filtered imaging scanning transmission electron microscopy with chromatic aberration correction.

    Science.gov (United States)

    Krause, F F; Rosenauer, A; Barthel, J; Mayer, J; Urban, K; Dunin-Borkowski, R E; Brown, H G; Forbes, B D; Allen, L J

    2017-10-01

    This paper addresses a novel approach to atomic resolution elemental mapping, demonstrating a method that produces elemental maps with a similar resolution to the established method of electron energy-loss spectroscopy in scanning transmission electron microscopy. Dubbed energy-filtered imaging scanning transmission electron microscopy (EFISTEM) this mode of imaging is, by the quantum mechanical principle of reciprocity, equivalent to tilting the probe in energy-filtered transmission electron microscopy (EFTEM) through a cone and incoherently averaging the results. In this paper we present a proof-of-principle EFISTEM experimental study on strontium titanate. The present approach, made possible by chromatic aberration correction, has the advantage that it provides elemental maps which are immune to spatial incoherence in the electron source, coherent aberrations in the probe-forming lens and probe jitter. The veracity of the experiment is supported by quantum mechanical image simulations, which provide an insight into the image-forming process. Elemental maps obtained in EFTEM suffer from the effect known as preservation of elastic contrast, which, for example, can lead to a given atomic species appearing to be in atomic columns where it is not to be found. EFISTEM very substantially reduces the preservation of elastic contrast and yields images which show stability of contrast with changing thickness. The experimental application is demonstrated in a proof-of-principle study on strontium titanate. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. External calibration strategy for trace element quantification in botanical samples by LA-ICP-MS using filter paper

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Matheus A.G.; Voss, Mônica; Corazza, Gabriela; Flores, Erico M.M.; Dressler, Valderi L., E-mail: vdressler@gmail.com

    2016-01-28

    The use of reference solutions dispersed on filter paper discs is proposed for the first time as an external calibration strategy for matrix matching and determination of As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sr, V and Zn in plants by laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS). The procedure is based on the use of filter paper discs as support for aqueous reference solutions, which are further evaporated, resulting in solid standards with concentrations up to 250 μg g{sup −1} of each element. The use of filter paper for calibration is proposed as matrix matched standards due to the similarities of this material with botanical samples, regarding to carbon concentration and its distribution through both matrices. These characteristics allowed the use of {sup 13}C as internal standard (IS) during the analysis by LA-ICP-MS. In this way, parameters as analyte signal normalization with {sup 13}C, carrier gas flow rate, laser energy, spot size, and calibration range were monitored. The calibration procedure using solution deposition on filter paper discs resulted in precision improvement when {sup 13}C was used as IS. The method precision was calculated by the analysis of a certified reference material (CRM) of botanical matrix, considering the RSD obtained for 5 line scans and was lower than 20%. Accuracy of LA-ICP-MS determinations were evaluated by analysis of four CRM pellets of botanical composition, as well as by comparison with results obtained by ICP-MS using solution nebulization after microwave assisted digestion. Plant samples of unknown elemental composition were analyzed by the proposed LA method and good agreement were obtained with results of solution analysis. Limits of detection (LOD) established for LA-ICP-MS were obtained by the ablation of 10 lines on the filter paper disc containing 40 μL of 5% HNO{sub 3} (v v{sup −1}) as calibration blank. Values ranged from 0.05 to 0.81  μg g{sup −1}. Overall, the use of filter

  13. Compact planar microwave blocking filters

    Science.gov (United States)

    U-Yen, Kongpop (Inventor); Wollack, Edward J. (Inventor)

    2012-01-01

    A compact planar microwave blocking filter includes a dielectric substrate and a plurality of filter unit elements disposed on the substrate. The filter unit elements are interconnected in a symmetrical series cascade with filter unit elements being organized in the series based on physical size. In the filter, a first filter unit element of the plurality of filter unit elements includes a low impedance open-ended line configured to reduce the shunt capacitance of the filter.

  14. Oxidation subscale of gamma-titanium aluminide

    NARCIS (Netherlands)

    Beye, R.; Verwerft, Marc; de Hosson, J.T.M.; Gronsky, R.

    1996-01-01

    The subscale formed during high temperature rapid oxidation of gamma-titanium aluminum is revealed by transmission electron microscopy and microanalysis to consist of two phases: one hexagonal with unit cell dimensions a = 0.58 nm, c = 0.47 nm (+/- 0.005 nm), and a composition close to Ti6Al3O4; the

  15. Ethical Perspectives: Leadership Subscales Applied to Education.

    Science.gov (United States)

    Gable, Sherry K.; Kavich, Larry L.

    Ethical perspectives are needed to gain insight into the history of leader behavior, especially as related to the current emphasis on contingency and Path-Goal Theories. An instrument to help select professionals who reflect ethical traits is the Leadership Behavior Description Questionnaire with 12 leadership subscales (LBDQ, Form XII). Selected…

  16. Wind Turbine Blade Design for Subscale Testing

    Science.gov (United States)

    Hassanzadeh, Arash; Naughton, Jonathan W.; Kelley, Christopher L.; Maniaci, David C.

    2016-09-01

    Two different inverse design approaches are proposed for developing wind turbine blades for sub-scale wake testing. In the first approach, dimensionless circulation is matched for full scale and sub-scale wind turbine blades for equal shed vorticity in the wake. In the second approach, the normalized normal and tangential force distributions are matched for large scale and small scale wind turbine blades, as these forces determine the wake dynamics and stability. The two approaches are applied for the same target full scale turbine blade, and the shape of the blades are compared. The results show that the two approaches have been successfully implemented, and the designed blades are able to produce the target circulation and target normal and tangential force distributions.

  17. Nonlinear tracking in a diffusion process with a Bayesian filter and the finite element method

    DEFF Research Database (Denmark)

    Pedersen, Martin Wæver; Thygesen, Uffe Høgsbro; Madsen, Henrik

    2011-01-01

    become complicated using SMC because Monte Carlo randomness is introduced. The finite element (FE) method solves the Kolmogorov equations of the SDE numerically on a triangular unstructured mesh for which boundary conditions to the state-space are simple to incorporate. The FE approach to nonlinear state...... estimation is suited for off-line data analysis because the computed smoothed state densities, maximum a posteriori parameter estimates and state sequence are deterministic conditional on the finite element mesh and the observations. The proposed method is conceptually similar to existing point...... on the state-space do not in general provide analytical solutions. A widely used numerical approach is the sequential Monte Carlo (SMC) method which relies on stochastic simulations to approximate state densities. For offline analysis, however, accurate smoothed state density and parameter estimation can...

  18. SCANNING ELECTRON MICROSCOPY OF “ROSA” FILTER ELEMENTS FROM HEMOFENIX APPARATUS, AND OF BLOOD IN MEMBRANE PLASMAPHERESIS AND LASER IRRADIATION

    Directory of Open Access Journals (Sweden)

    I. M. Baybekov

    2013-01-01

    Full Text Available Aim. To study with scanning electron microscopy an interaction between structural elements of “Rosa” filters (a component of HEMOFENIХ with erythrocytes during membrane plasmapheresis and under the effect of la- ser irradiation performed during plasmapheresis. Materials and methods. Using scanning electron microscopy and morphometry, blood cells and plasma-filter components were studied in patients with myasthenia gravis. Results. It has been revealed that the percentage of pathologic forms of erythrocytes increased in peripheral blood of patients with myasthenia gravis. Plasmapheresis leads to an increase in the number of pathologic forms of erythrocytes in peripheral blood as well as on plasma-filter components. Conclusion. Laser irradiation, in turn, promotes the significant reduction of pathological forms of erythrocytes number in peripheral blood and on plasma-filter components. 

  19. Results of subscale MTF compression experiments

    Science.gov (United States)

    Howard, Stephen; Mossman, A.; Donaldson, M.; Fusion Team, General

    2016-10-01

    In magnetized target fusion (MTF) a magnetized plasma torus is compressed in a time shorter than its own energy confinement time, thereby heating to fusion conditions. Understanding plasma behavior and scaling laws is needed to advance toward a reactor-scale demonstration. General Fusion is conducting a sequence of subscale experiments of compact toroid (CT) plasmas being compressed by chemically driven implosion of an aluminum liner, providing data on several key questions. CT plasmas are formed by a coaxial Marshall gun, with magnetic fields supported by internal plasma currents and eddy currents in the wall. Configurations that have been compressed so far include decaying and sustained spheromaks and an ST that is formed into a pre-existing toroidal field. Diagnostics measure B, ne, visible and x-ray emission, Ti and Te. Before compression the CT has an energy of 10kJ magnetic, 1 kJ thermal, with Te of 100 - 200 eV, ne 5x1020 m-3. Plasma was stable during a compression factor R0/R >3 on best shots. A reactor scale demonstration would require 10x higher initial B and ne but similar Te. Liner improvements have minimized ripple, tearing and ejection of micro-debris. Plasma facing surfaces have included plasma-sprayed tungsten, bare Cu and Al, and gettering with Ti and Li.

  20. A medical risk attitude subscale for DOSPERT

    Directory of Open Access Journals (Sweden)

    Shoshana Butler

    2012-03-01

    Full Text Available Background: The Domain-Specific Risk Taking scale (DOSPERT is a widely used instrument that measures perceived risk and benefit and attitude toward risk for activities in several domains, but does not include medical risks. Objective: To develop a medical risk domain subscale for DOSPERT. Methods: Sixteen candidate risk items were developed through expert discussion. We conducted cognitive telephone interviews, an online survey, and a random-digit dialing (RDD telephone survey to reduce and refine the scale, explore its factor structure, and obtain estimates of reliability. Participants: Eight patients recruited from UIC medical center waiting rooms participated in 45-60 minute cognitive interviews. Thirty Amazon Mechanical Turk workers completed the online survey. One hundred Chicago-area residents completed the RDD telephone survey. Results: On the basis of cognitive interviews, we eliminated five items due to poor variance or participant misunderstanding. The online survey suggested that two additional items were negatively correlated with the scale, and we considered them candidates for removal. Factor analysis of the responses in the RDD telephone survey and non-statistical factors led us to recommend a final set of 6 items to represent the medical risk domain. The final set of items included blood donation, kidney donation, daily medication use for allergies, knee replacement surgery, general anesthesia in dentistry, and clinical trial participation. The interitem reliability (Cronbach's alpha of the final set of 6 items ranged from 0.57-0.59 depending on the response task. Older respondents gave lower overall ratings of expected benefit from the activities. Conclusion: We refined a set of items to measure risk and benefit perceptions for medical activities. Our next step will be to add these items to the complete DOSPERT scale, confirm the scale's psychometric properties, determine whether medical risks constitute a psychologically

  1. Spatial filters for high average power lasers

    Science.gov (United States)

    Erlandson, Alvin C

    2012-11-27

    A spatial filter includes a first filter element and a second filter element overlapping with the first filter element. The first filter element includes a first pair of cylindrical lenses separated by a first distance. Each of the first pair of cylindrical lenses has a first focal length. The first filter element also includes a first slit filter positioned between the first pair of cylindrical lenses. The second filter element includes a second pair of cylindrical lenses separated by a second distance. Each of the second pair of cylindrical lenses has a second focal length. The second filter element also includes a second slit filter positioned between the second pair of cylindrical lenses.

  2. Simulation of a GOX-kerosene subscale rocket combustion chamber

    Science.gov (United States)

    Höglauer, Christoph; Kniesner, Björn; Knab, Oliver; Kirchberger, Christoph; Schlieben, Gregor; Kau, Hans-Peter

    2011-12-01

    In view of future film cooling tests at the Institute for Flight Propulsion (LFA) at Technische Universität München, the Astrium in-house spray combustion CFD tool Rocflam-II was validated against first test data gained from this rocket test bench without film cooling. The subscale rocket combustion chamber uses GOX and kerosene as propellants which are injected through a single double swirl element. Especially the modeling of the double swirl element and the measured wall roughness were adapted on the LFA hardware. Additionally, new liquid kerosene fluid properties were implemented and verified in Rocflam-II. Also the influences of soot deposition and hot gas radiation on the wall heat flux were analytically and numerically estimated. In context of reviewing the implemented evaporation model in Rocflam-II, the binary diffusion coefficient and its pressure dependency were analyzed. Finally simulations have been performed for different load points with Rocflam-II showing a good agreement compared to test data.

  3. Implicit filtered P{sub N} for high-energy density thermal radiation transport using discontinuous Galerkin finite elements

    Energy Technology Data Exchange (ETDEWEB)

    Laboure, Vincent M., E-mail: vincent.laboure@tamu.edu [Nuclear Engineering Department, Texas A& M University, College Station, TX 77843 (United States); McClarren, Ryan G., E-mail: rgm@tamu.edu [Nuclear Engineering Department, Texas A& M University, College Station, TX 77843 (United States); Hauck, Cory D., E-mail: hauckc@ornl.gov [Computational and Applied Mathematics Group, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Department of Mathematics, University of Tennessee Knoxville, TN 37996-1320 (United States)

    2016-09-15

    In this work, we provide a fully-implicit implementation of the time-dependent, filtered spherical harmonics (FP{sub N}) equations for non-linear, thermal radiative transfer. We investigate local filtering strategies and analyze the effect of the filter on the conditioning of the system, showing in particular that the filter improves the convergence properties of the iterative solver. We also investigate numerically the rigorous error estimates derived in the linear setting, to determine whether they hold also for the non-linear case. Finally, we simulate a standard test problem on an unstructured mesh and make comparisons with implicit Monte Carlo (IMC) calculations.

  4. Longitudinal Construct Validity of Brief Symptom Inventory Subscales in Schizophrenia

    Science.gov (United States)

    Long, Jeffrey D.; Harring, Jeffrey R.; Brekke, John S.; Test, Mary Ann; Greenberg, Jan

    2007-01-01

    Longitudinal validity of Brief Symptom Inventory subscales was examined in a sample (N = 318) with schizophrenia-related illness measured at baseline and every 6 months for 3 years. Nonlinear factor analysis of items was used to test graded response models (GRMs) for subscales in isolation. The models varied in their within-time and between-times…

  5. Development of filter element from nanocomposites of ultra high molar mass polyethylene having silver nanoparticles; Desenvolvimento de elemento filtrante a partir de nanocompositos de polietileno de ultra-alta massa molar contendo nanoparticulas de prata

    Energy Technology Data Exchange (ETDEWEB)

    Bizzo, Maurizio A.; Wang, S. Hui, E-mail: mbizzo@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Escola Politecnica de Engenharia Metalurgica e de Materiais

    2015-07-01

    The production of polymer based filter elements for water is widespread in the market but has an undesirable characteristic, they are not always efficient and capable of retaining or eliminating microorganisms. This paper proposes the production of filters with biocidal activity, comprised by nanocomposites of ultra-high molar mass polyethylene (UHMMPE) containing silver nanoparticles. The polymer is responsible for the uniform porous structure of the filter element and the Ag nanoparticles for its biocidal action. The filter elements were produced from two kinds of UHMMPE particles with different particle size distributions, one in the range of 150 to 200μm and the other of 300 to 400μm. Samples were collected from the obtained filter elements and characterized by X-ray diffractometry, scanning electron microscopy and microanalysis. The results indicated the formation of nanocomposite containing silver nanoparticles. (author)

  6. A technique for monitoring SO2 in combustion exhausts: Use of a non-Nernstian sensing element in combination with an upstream catalytic filter

    Energy Technology Data Exchange (ETDEWEB)

    West, David L [ORNL; Montgomery, Fred C [ORNL; Armstrong, Timothy R. [ORNL

    2009-01-01

    Detection of sulfur dioxide (SO2) at high temperature (600 750 oC) in the presence of some interferents found in typical combustion exhausts (oxides of nitrogen (NO2 and NO, "NOx"), CO2, CO, and hydrocarbon (C3H6)) is described. The detection scheme involves use of a catalytic filter in front of a non-Nernstian sensing element. The catalytic filter was a Ni:Cr powder bed operating at 850 oC and the sensing elements were pairs of platinum (Pt) and oxide (Ba-promoted copper chromite ((Ba,Cu)xCryOz) and Sr-modified lanthanum ferrite (LSF)) electrodes on yttria-stabilized zirconia. The Ni:Cr powder bed was capable of reducing the sensing element response to NOx, CO, and C3H6, but the presence of NOx (100 ppm by volume) still interfered with the SO2 response of the Pt-(Ba,Cu)xCryOz sensing element at 600 oC, causing approximately a 7 mV (20%) reduction in the response to 120 ppm SO2 and a response equivalent to about 20 ppm SO2 in the in the absence of SO2. The Pt-LSF sensing element, operated at 750 oC, did not suffer from this NOx interference but at the cost of a reduced SO2 response magnitude (120 ppm SO2 yielded ~10 mV, in contrast to ~30 mV for the Pt-(Ba,Cu)xCryOz sensing element). The powder bed and Pt-LSF sensing element were operated continuously over approximately 350 hours, and the response to SO2 drifted downward by about 7%, with most of this change occurring during the initial 100 hours of operation.

  7. A Nonlinear Dynamic Subscale Model for Partially Resolved Numerical Simulation (PRNS)/Very Large Eddy Simulation (VLES) of Internal Non-Reacting Flows

    Science.gov (United States)

    Shih, Tsan-Hsing; Liu, nan-Suey

    2010-01-01

    A brief introduction of the temporal filter based partially resolved numerical simulation/very large eddy simulation approach (PRNS/VLES) and its distinct features are presented. A nonlinear dynamic subscale model and its advantages over the linear subscale eddy viscosity model are described. In addition, a guideline for conducting a PRNS/VLES simulation is provided. Results are presented for three turbulent internal flows. The first one is the turbulent pipe flow at low and high Reynolds numbers to illustrate the basic features of PRNS/VLES; the second one is the swirling turbulent flow in a LM6000 single injector to further demonstrate the differences in the calculated flow fields resulting from the nonlinear model versus the pure eddy viscosity model; the third one is a more complex turbulent flow generated in a single-element lean direct injection (LDI) combustor, the calculated result has demonstrated that the current PRNS/VLES approach is capable of capturing the dynamically important, unsteady turbulent structures while using a relatively coarse grid.

  8. Airspace Simulation Through Indoor Operation of Subscale Flight Vehicles Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An indoor environment for simulating airspace operations will be designed. Highly maneuverable subscale vehicles can be used to simulate the dynamics of full-scale...

  9. Functional autonomy measurement system: development of a social subscale.

    Science.gov (United States)

    Pinsonnault, E; Desrosiers, J; Dubuc, N; Kalfat, H; Colvez, A; Delli-Colli, N

    2003-01-01

    The purpose of this study was to develop a subscale assessing social functioning for the functional autonomy measurement system (SMAF). The development of this new dimension was based on consultations (focus groups and nominal groups) of experts from different health care disciplines in Quebec, Canada, and France. Two interrater reliability studies were carried out with older people presenting a loss of functional autonomy and living either in an institution or at home. With the focus groups, the experts clarified the definition of social functioning and identified the factors involved. The nominal groups were used to construct a subscale composed of six items. The results of the first interrater reliability study showed a mean agreement percentage of 60% for the subscale and an intraclass correlation coefficient (ICC) of 0.70 (CI: 0.57-0.80). The results of the second interrater reliability study showed higher coefficients with an agreement percentage of 74% for the subscale and an ICC of 0.83 (CI: 0.61-0.93). These preliminary results demonstrate that the new social functioning subscale has good reliability, but more studies are needed to show its validity. The new SMAF, including the social functioning subscale, should help clinicians and researchers to obtain a comprehensive profile of functional autonomy. It could also contribute to the improvement of health care for older people.

  10. Filter service system

    Science.gov (United States)

    Sellers, Cheryl L [Peoria, IL; Nordyke, Daniel S [Arlington Heights, IL; Crandell, Richard A [Morton, IL; Tomlins, Gregory [Peoria, IL; Fei, Dong [Peoria, IL; Panov, Alexander [Dunlap, IL; Lane, William H [Chillicothe, IL; Habeger, Craig F [Chillicothe, IL

    2008-12-09

    According to an exemplary embodiment of the present disclosure, a system for removing matter from a filtering device includes a gas pressurization assembly. An element of the assembly is removably attachable to a first orifice of the filtering device. The system also includes a vacuum source fluidly connected to a second orifice of the filtering device.

  11. Finite Element Modelling of a Field-Sensed Magnetic Suspended System for Accurate Proximity Measurement Based on a Sensor Fusion Algorithm with Unscented Kalman Filter.

    Science.gov (United States)

    Chowdhury, Amor; Sarjaš, Andrej

    2016-09-15

    The presented paper describes accurate distance measurement for a field-sensed magnetic suspension system. The proximity measurement is based on a Hall effect sensor. The proximity sensor is installed directly on the lower surface of the electro-magnet, which means that it is very sensitive to external magnetic influences and disturbances. External disturbances interfere with the information signal and reduce the usability and reliability of the proximity measurements and, consequently, the whole application operation. A sensor fusion algorithm is deployed for the aforementioned reasons. The sensor fusion algorithm is based on the Unscented Kalman Filter, where a nonlinear dynamic model was derived with the Finite Element Modelling approach. The advantage of such modelling is a more accurate dynamic model parameter estimation, especially in the case when the real structure, materials and dimensions of the real-time application are known. The novelty of the paper is the design of a compact electro-magnetic actuator with a built-in low cost proximity sensor for accurate proximity measurement of the magnetic object. The paper successively presents a modelling procedure with the finite element method, design and parameter settings of a sensor fusion algorithm with Unscented Kalman Filter and, finally, the implementation procedure and results of real-time operation.

  12. Finite Element Modelling of a Field-Sensed Magnetic Suspended System for Accurate Proximity Measurement Based on a Sensor Fusion Algorithm with Unscented Kalman Filter

    Science.gov (United States)

    Chowdhury, Amor; Sarjaš, Andrej

    2016-01-01

    The presented paper describes accurate distance measurement for a field-sensed magnetic suspension system. The proximity measurement is based on a Hall effect sensor. The proximity sensor is installed directly on the lower surface of the electro-magnet, which means that it is very sensitive to external magnetic influences and disturbances. External disturbances interfere with the information signal and reduce the usability and reliability of the proximity measurements and, consequently, the whole application operation. A sensor fusion algorithm is deployed for the aforementioned reasons. The sensor fusion algorithm is based on the Unscented Kalman Filter, where a nonlinear dynamic model was derived with the Finite Element Modelling approach. The advantage of such modelling is a more accurate dynamic model parameter estimation, especially in the case when the real structure, materials and dimensions of the real-time application are known. The novelty of the paper is the design of a compact electro-magnetic actuator with a built-in low cost proximity sensor for accurate proximity measurement of the magnetic object. The paper successively presents a modelling procedure with the finite element method, design and parameter settings of a sensor fusion algorithm with Unscented Kalman Filter and, finally, the implementation procedure and results of real-time operation. PMID:27649197

  13. Regenerative particulate filter development

    Science.gov (United States)

    Descamp, V. A.; Boex, M. W.; Hussey, M. W.; Larson, T. P.

    1972-01-01

    Development, design, and fabrication of a prototype filter regeneration unit for regenerating clean fluid particle filter elements by using a backflush/jet impingement technique are reported. Development tests were also conducted on a vortex particle separator designed for use in zero gravity environment. A maintainable filter was designed, fabricated and tested that allows filter element replacement without any leakage or spillage of system fluid. Also described are spacecraft fluid system design and filter maintenance techniques with respect to inflight maintenance for the space shuttle and space station.

  14. Subscale Water Based Phase Change Material Heat Exchanger Development

    Science.gov (United States)

    Sheth, Rubik; Hansen, Scott

    2016-01-01

    Supplemental heat rejection devices are required in many spacecraft as the radiators are not sized to meet the full heat rejection demand. One means of obtaining additional heat rejection is through the use of phase change material heat exchangers (PCM HX's). PCM HX's utilize phase change to store energy in unfavorable thermal environments (melting) and reject the energy in favorable environments (freezing). Traditionally, wax has been used as a PCM on spacecraft. However, water is an attractive alternative because it is capable of storing about 40% more energy per unit mass due to its higher latent heat of fusion. The significant problem in using water as a PCM is its expansion while freezing, leading to structural integrity concerns when housed in an enclosed heat exchanger volume. Significant investigation and development has taken place over the past five years to understand and overcome the problems associated with water PCM HX's. This paper reports on the final efforts by Johnson Space Center's Thermal Systems Branch to develop a water based PCM HX. The test article developed and reported on is a subscale version of the full-scale water-based PCM HX's constructed by Mezzo Technologies. The subscale unit was designed by applying prior research on freeze front propagation and previous full-scale water PCM HX development. Design modifications to the subscale unit included use of urethane bladder, decreased aspect ratio, perforated protection sheet, and use of additional mid-plates. Testing of the subscale unit was successful and 150 cycles were completed without fail.

  15. The use of cation exchange matrix separation coupled with ICP-MS to directly determine platinum group element (PGE) and other trace element emissions from passenger cars equipped with diesel particulate filters (DPF)

    Energy Technology Data Exchange (ETDEWEB)

    Cairns, Warren R.L.; Cozzi, Giulio [Institute for the Dynamics of Environmental Processes-CNR, Venice (Italy); De Boni, Antonella; Gabrieli, Jacopo [University of Venice, Department of Environmental Science, Venice (Italy); Asti, Massimo; Merlone Borla, Edoardo; Parussa, Flavio [Centro Ricerche Fiat, Orbassano (Italy); Moretto, Ezio [FIAT Powertrain Technologies S.p.A, Turin (Italy); Cescon, Paolo; Barbante, Carlo [University of Venice, Department of Environmental Science, Venice (Italy); Institute for the Dynamics of Environmental Processes-CNR, Venice (Italy); Boutron, Claude [Laboratoire de Glaciologie et Geophysique de l' Environnement, UMR CNRS 5183, B.P. 96, Saint Martin d' Heres Cedex (France)

    2011-03-15

    Inductively coupled plasma-mass spectrometry coupled with cation exchange matrix separation has been optimised for the direct determination of platinum group element (PGE) and trace element emissions from a diesel engine car. After matrix separation method detection limits of 1.6 ng g{sup -1} for Pd, 0.4 ng g{sup -1} for Rh and 4.3 ng g{sup -1} for Pt were achieved, the method was validated against the certified reference material BCR 723, urban road dust. The test vehicle was fitted with new and aged catalytic converters with and without diesel particulate filters (DPF). Samples were collected after three consecutive New European Driving Cycle (NEDC) of the particulate and ''soluble'' phases using a home-made sampler optimised for trace element analysis. Emission factors for the PGEs ranged from 0.021 ng km{sup -1} for Rh to 70.5 ng km{sup -1} for Pt; when a DPF was fitted, the emission factors for the PGEs actually used in the catalysts dropped by up to 97% (for Pt). Trace element emission factors were found to drop by a maximum of 92% for Ni to a minimum of 18% for Y when a DPF was fitted; a new DPF was also found to cause a reduction of up to 86% in the emission of particulate matter. (orig.)

  16. The use of cation exchange matrix separation coupled with ICP-MS to directly determine platinum group element (PGE) and other trace element emissions from passenger cars equipped with diesel particulate filters (DPF).

    Science.gov (United States)

    Cairns, Warren R L; De Boni, Antonella; Cozzi, Giulio; Asti, Massimo; Borla, Edoardo Merlone; Parussa, Flavio; Moretto, Ezio; Cescon, Paolo; Boutron, Claude; Gabrieli, Jacopo; Barbante, Carlo

    2011-03-01

    Inductively coupled plasma-mass spectrometry coupled with cation exchange matrix separation has been optimised for the direct determination of platinum group element (PGE) and trace element emissions from a diesel engine car. After matrix separation method detection limits of 1.6 ng g(-1) for Pd, 0.4 ng g(-1) for Rh and 4.3 ng g(-1) for Pt were achieved, the method was validated against the certified reference material BCR 723, urban road dust. The test vehicle was fitted with new and aged catalytic converters with and without diesel particulate filters (DPF). Samples were collected after three consecutive New European Driving Cycle (NEDC) of the particulate and "soluble" phases using a home-made sampler optimised for trace element analysis. Emission factors for the PGEs ranged from 0.021 ng km(-1) for Rh to 70.5 ng km(-1) for Pt; when a DPF was fitted, the emission factors for the PGEs actually used in the catalysts dropped by up to 97% (for Pt). Trace element emission factors were found to drop by a maximum of 92% for Ni to a minimum of 18% for Y when a DPF was fitted; a new DPF was also found to cause a reduction of up to 86% in the emission of particulate matter.

  17. Investigation of pseudo bi-polar nickel-cadmium batteries as filter elements for pulsed power loads. Master's thesis

    Energy Technology Data Exchange (ETDEWEB)

    Cimino, M.B.; Gearing, G.M.

    1984-12-01

    This investigation consisted of several tests of specially fabricated nickel-cadmium batteries having circular disk-type electrodes. These batteries were evaluated as filter elements between a constant-current power supply and a 5-Hz pulsed load demanding approximately twice the power-supply current during the load on portion of the cycle. Short tests lasting 10,000 cycles were conducted at up to 21 C rate and an equivalent energy density of over 40 Joules per pound. In addition, two batteries were subjected to 10,000,000 charge/discharge cycles, one at a 6.5 C rate and the other at a 13 C rate. Assuming an electrode-to-battery weight ratio of 0.5, these tests represent an energy density of about 7 and 14 Joules per pound, respectively. Energy density, efficiency, capacitance, average voltage, and available capacity were tracked during these tests.

  18. Experimental formulation of a kinetic model describing the nitrification process in biological aerated filters filled with plastic elements.

    Science.gov (United States)

    Siciliano, Alessio; De Rosa, Salvatore

    2015-01-01

    The present work reports the results of a series of experimental tests performed on cylindrically shaped biological aerated filters (BAFs) to define a new model for reactors design. The nitrification performance was analysed by monitoring a laboratory pilot plant over a six-month period; the dependence of the nitrification rate from the biomass surface density, from ammonia nitrogen concentration and dissolved oxygen concentration was determined using kinetic batch tests. The controls performed on the pilot plant exhibited a nitrification efficiency of approximately 98% at loadings up to [Formula: see text]. Over this value, the pilot plant performance decreased without a correlation with the applied loads. In response to the inlet ammonia loading increase, the bacterial surface density showed a logistic growing trend. The results of kinetic tests proved that the nitrification rate was not affected by the ammonia nitrogen concentration; instead, a first-order kinetic with respect to the dissolved oxygen concentration was detected. Moreover, it was observed that a minimum oxygen concentration, which was proportional to the bacterial surface density, was necessary to initiate the nitrification process. The reaction rate related to bacterial surface density exhibited an increasing trend that was followed by a subsequent decreasing behaviour. The results of kinetic tests and the identification of the relationship between bacterial surface density and ammonia loading permitted the formulation of a mathematical model to predict BAFs' nitrification efficiency.

  19. Subscale Acoustic Testing: Comparison of ALAT and ASMAT

    Science.gov (United States)

    Houston, Janice D.; Counter, Douglas

    2014-01-01

    The liftoff phase induces acoustic loading over a broad frequency range for a launch vehicle. These external acoustic environments are then used in the prediction of internal vibration responses of the vehicle and components which result in the qualification levels. Thus, predicting these liftoff acoustic environments is critical to the design requirements of any launch vehicle. If there is a significant amount of uncertainty in the predictions or if acoustic mitigation options must be implemented, a subscale acoustic test is a feasible pre-launch test option. This paper compares the acoustic measurements of two different subscale tests: the 2% Ares Liftoff Acoustic Test conducted at Stennis Space Center and the 5% Ares I Scale Model Acoustic Test conducted at Marshall Space Flight Center.

  20. Energy Cascade Analysis: from Subscale Eddies to Mean Flow

    Science.gov (United States)

    Cheikh, Mohamad Ibrahim; Wonnell, Louis; Chen, James

    2017-11-01

    Understanding the energy transfer between eddies and mean flow can provide insights into the energy cascade process. Much work has been done to investigate the energy cascade at the level of the smallest eddies using different numerical techniques derived from the Navier-Stokes equations. These methodologies, however, prove to be computationally inefficient when producing energy spectra for a wide range of length scales. In this regard, Morphing Continuum Theory (MCT) resolves the length-scales issues by assuming the fluid continuum to be composed of inner structures that play the role of subscale eddies. The current study show- cases the capabilities of MCT in capturing the dynamics of energy cascade at the level of subscale eddies, through a supersonic turbulent flow of Mach 2.93 over an 8× compression ramp. Analysis of the results using statistical averaging procedure shows the existence of a statistical coupling of the internal and translational kinetic energy fluctuations with the corresponding rotational kinetic energy of the subscale eddies, indicating a multiscale transfer of energy. The results show that MCT gives a new characterization of the energy cascade within compressible turbulence without the use of excessive computational resources. This material is based upon work supported by the Air Force Office of Scientific Research under Award Number FA9550-17-1-0154.

  1. Spatial filters for high power lasers

    Science.gov (United States)

    Erlandson, Alvin Charles; Bayramian, Andrew James

    2014-12-02

    A spatial filter includes a first filter element and a second filter element overlapping with the first filter element. The first filter element includes a first pair of cylindrical lenses separated by a first distance. Each of the first pair of cylindrical lenses has a first focal length. The first filter element also includes a first longitudinal slit filter positioned between the first pair of cylindrical lenses. The second filter element includes a second pair of cylindrical lenses separated by a second distance. Each of the second pair of cylindrical lenses has a second focal length. The second filter element also includes a second longitudinal slit filter positioned between the second pair of cylindrical lenses.

  2. Subscale Validation of the Subsurface Active Filtration of Exhaust (SAFE) Approach to the NTP Ground Testing

    Science.gov (United States)

    Marshall, William M.; Borowski, Stanley K.; Bulman, Mel; Joyner, Russell; Martin, Charles R.

    2015-01-01

    Nuclear thermal propulsion (NTP) has been recognized as an enabling technology for missions to Mars and beyond. However, one of the key challenges of developing a nuclear thermal rocket is conducting verification and development tests on the ground. A number of ground test options are presented, with the Sub-surface Active Filtration of Exhaust (SAFE) method identified as a preferred path forward for the NTP program. The SAFE concept utilizes the natural soil characteristics present at the Nevada National Security Site to provide a natural filter for nuclear rocket exhaust during ground testing. A validation method of the SAFE concept is presented, utilizing a non-nuclear sub-scale hydrogen/oxygen rocket seeded with detectible radioisotopes. Additionally, some alternative ground test concepts, based upon the SAFE concept, are presented. Finally, an overview of the ongoing discussions of developing a ground test campaign are presented.

  3. Water Filter

    Science.gov (United States)

    1982-01-01

    A compact, lightweight electrolytic water sterilizer available through Ambassador Marketing, generates silver ions in concentrations of 50 to 100 parts per billion in water flow system. The silver ions serve as an effective bactericide/deodorizer. Tap water passes through filtering element of silver that has been chemically plated onto activated carbon. The silver inhibits bacterial growth and the activated carbon removes objectionable tastes and odors caused by addition of chlorine and other chemicals in municipal water supply. The three models available are a kitchen unit, a "Tourister" unit for portable use while traveling and a refrigerator unit that attaches to the ice cube water line. A filter will treat 5,000 to 10,000 gallons of water.

  4. Description and Operation of the A3 Subscale Facility

    Science.gov (United States)

    Saunders, G. P.; Varner, D. G.; Grover, J. B.

    2010-01-01

    The purpose of this paper is to give an overview of the general design and operation of the A3 Subscale test facility. The goal is to provide the reader with a general understanding of what the major facility systems are, where they are located, and how they are used to meet the objectives supporting the design of the A3 altitude rocket test facility. This paper also provides the reader with the background information prior to reading the subsequent papers detailing the design and test results of the various systems described herein.

  5. Contactor/filter improvements

    Science.gov (United States)

    Stelman, David

    1989-01-01

    A contactor/filter arrangement for removing particulate contaminants from a gaseous stream includes a housing having a substantially vertically oriented granular material retention member with upstream and downstream faces, a substantially vertically oriented microporous gas filter element, wherein the retention member and the filter element are spaced apart to provide a zone for the passage of granular material therethrough. The housing further includes a gas inlet means, a gas outlet means, and means for moving a body of granular material through the zone. A gaseous stream containing particulate contaminants passes through the gas inlet means as well as through the upstream face of the granular material retention member, passing through the retention member, the body of granular material, the microporous gas filter element, exiting out of the gas outlet means. Disposed on the upstream face of the filter element is a cover screen which isolates the filter element from contact with the moving granular bed and collects a portion of the particulates so as to form a dust cake having openings small enough to exclude the granular material, yet large enough to receive the dust particles. In one embodiment, the granular material is comprised of prous alumina impregnated with CuO, with the cover screen cleaned by the action of the moving granular material as well as by backflow pressure pulses.

  6. The Mechanical Performance of Subscale Candidate Elastomer Docking Seals

    Science.gov (United States)

    Bastrzyk, Marta B.; Daniels, Christopher C.

    2010-01-01

    The National Aeronautics and Space Administration is developing a Low Impact Docking System (LIDS) for future exploration missions. The mechanism is a new state-of-the-art device for in-space assembly of structures and rendezvous of vehicles. At the interface between two pressurized modules, each with a version of the LIDS attached, a composite elastomer-metal seal assembly prevents the breathable air from escaping into the vacuum of space. Attached to the active LIDS, this seal mates against the passive LIDS during docking operation. The main interface seal assembly must exhibit low leak and outgas values, must be able to withstand various harsh space environments, must remain operational over a range of temperatures from -50 C to 75 C, and perform after numerous docking cycles. This paper presents results from a comprehensive study of the mechanical performance of four candidate subscale seal assembly designs at -50, 23, 50, and 75 C test temperatures. In particular, the force required to fully compress the seal during docking, and that which is required for separation during the undocking operation were measured. The height of subscale main interface seal bulbs, as well as the test temperature, were shown to have a significant effect on the forces the main interface seal of the LIDS may experience during docking and undocking operations. The average force values required to fully compress each of the seal assemblies were shown to increase with test temperature by approximately 50% from -50 to 75 C. Also, the required compression forces were shown to increase as the height of the seal bulb was increased. The seal design with the tallest elastomer seal bulb, which was 31% taller than that with the shortest bulb, required force values approximately 45% higher than those for the shortest bulb, independent of the test temperature. The force required to separate the seal was shown to increase with decreasing temperature after 15 hours of simulated docking. No adhesion

  7. Evaluation of the ICET Test Stand to Assess the Performance of a Range of Ceramic Media Filter Elements in Support of ASME AG-1 Subsection FO

    Energy Technology Data Exchange (ETDEWEB)

    Schemmel, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-04-26

    High Efficiency Particulate Air (HEPA) filters are defined as extended-medium, dry-type filters with: (1) a minimum particle removal efficiency of no less than 99.97 percent for 0.3 micrometer particles, (2) a maximum, clean resistance of 1.0 inch water column (in. WC) when operated at 1,000 cubic feet per minute (CFM), and (3) a rigid casing that extends the full depth of the medium. Specifically, ceramic media HEPA filters provide better performance at elevated temperatures, are moisture resistant and nonflammable, can perform their function if wetted and exposed to greater pressures, and can be cleaned and reused. This paper describes the modification and design of a large scale test stand which properly evaluates the filtration characteristics of a range of ceramic media filters challenged with a nuclear aerosol agent in order to develop Section FO of ASME AG-1.

  8. SPE5 Sub-Scale Test Series Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Vandersall, Kevin S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reeves, Robert V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); DeHaven, Martin R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Strickland, Shawn L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-01-14

    A series of 2 SPE5 sub-scale tests were performed to experimentally confirm that a booster system designed and evaluated in prior tests would properly initiate the PBXN-110 case charge fill. To conduct the experiments, a canister was designed to contain the nominally 50 mm diameter booster tube with an outer fill of approximately 150 mm diameter by 150 mm in length. The canisters were filled with PBXN-110 at NAWS-China Lake and shipped back to LLNL for testing in the High Explosives Applications Facility (HEAF). Piezoelectric crystal pins were placed on the outside of the booster tube before filling, and a series of piezoelectric crystal pins along with Photonic Doppler Velocimetry (PDV) probes were placed on the outer surface of the canister to measure the relative timing and magnitude of the detonation. The 2 piezoelectric crystal pins integral to the booster design were also utilized along with a series of either piezoelectric crystal pins or piezoelectric polymer pads on the top of the canister or outside case that utilized direct contact, gaps, or different thicknesses of RTV cushions to obtain time of arrival data to evaluate the response in preparation for the large-scale SPE5 test. To further quantify the margin of the booster operation, the 1st test (SPE5SS1) was functioned with both detonators and the 2nd test (SPE5SS2) was functioned with only 1 detonator. A full detonation of the material was observed in both experiments as observed by the pin timing and PDV signals. The piezoelectric pads were found to provide a greater measured signal magnitude during the testing with an RTV layer present, and the improved response is due to the larger measurement surface area of the pad. This report will detail the experiment design, canister assembly for filling, final assembly, experiment firing, presentation of the diagnostic results, and a discussion of the results.

  9. Water Filters

    Science.gov (United States)

    1993-01-01

    The Aquaspace H2OME Guardian Water Filter, available through Western Water International, Inc., reduces lead in water supplies. The filter is mounted on the faucet and the filter cartridge is placed in the "dead space" between sink and wall. This filter is one of several new filtration devices using the Aquaspace compound filter media, which combines company developed and NASA technology. Aquaspace filters are used in industrial, commercial, residential, and recreational environments as well as by developing nations where water is highly contaminated.

  10. Applying posttraumatic stress disorder MMPI subscale to World War II POW veterans.

    Science.gov (United States)

    Query, W T; Megran, J; McDonald, G

    1986-03-01

    In order to determine whether the MMPI-PTSD subscale has application for assessing DSM-III diagnosed PTSD among populations other than Vietnam veterans, a group of WWII POWs (N = 69) were given the subscale. Results indicated that the use of the PTSD subscale can be generalized to older veterans; in a small sample of Pacific POWs, PTSD is more common among those from the Pacific theater than those from Europe. However, the subscale fails to distinguish between Pacific and European POW veterans. Difficulties in sampling and confounding stressors are discussed, as well as implications for treatment of WWII veterans.

  11. Water Filters

    Science.gov (United States)

    1987-01-01

    A compact, lightweight electrolytic water filter generates silver ions in concentrations of 50 to 100 parts per billion in the water flow system. Silver ions serve as effective bactericide/deodorizers. Ray Ward requested and received from NASA a technical information package on the Shuttle filter, and used it as basis for his own initial development, a home use filter.

  12. Optimal filtering

    CERN Document Server

    Anderson, Brian D O

    1979-01-01

    This graduate-level text augments and extends beyond undergraduate studies of signal processing, particularly in regard to communication systems and digital filtering theory. Vital for students in the fields of control and communications, its contents are also relevant to students in such diverse areas as statistics, economics, bioengineering, and operations research.Topics include filtering, linear systems, and estimation; the discrete-time Kalman filter; time-invariant filters; properties of Kalman filters; computational aspects; and smoothing of discrete-time signals. Additional subjects e

  13. Image Filtering with Field Programmable Gate Array

    Directory of Open Access Journals (Sweden)

    Arūnas Šlenderis

    2013-05-01

    Full Text Available The research examined the use of field programmable gate arrays (FPGA in image filtering. Experimental and theoretical researches were reviewed. Experiments with Cyclone III family FPGA chip with implemented NIOS II soft processor were considered. Image filtering was achieved with symmetrical and asymmetrical finite impulse response filters with convolution kernel. The system, which was implemented with 3×3 symmetrical filter, which was implemented using the hardware description language, uses 59% of logic elements of the chip and 10 multiplication elements. The system with asymmetrical filter uses the same amount of logic elements and 13 multiplication elements. Both filter systems consume approx. 545 mW of power. The system, which is designed for filter implementation in C language, uses 65% of all logical elements and consumes 729 mW of power.Article in Lithuanian

  14. Increasing the Precision of Subscale Scores by Using Out-of-Scale Information

    Science.gov (United States)

    Kahraman, Nilufer; Kamata, Akihito

    2004-01-01

    In this study, the precision of subscale score estimates was evaluated when out-of-scale information was incorporated. Procedures that incorporated out-of-scale information and only information within a subscale were compared through a series of simulations. It was revealed that more information (i.e., more precision) was always provided for…

  15. Flight prototype regenerative particulate filter system development

    Science.gov (United States)

    Green, D. C.; Garber, P. J.

    1974-01-01

    The effort to design, fabricate, and test a flight prototype Filter Regeneration Unit used to regenerate (clean) fluid particulate filter elements is reported. The design of the filter regeneration unit and the results of tests performed in both one-gravity and zero-gravity are discussed. The filter regeneration unit uses a backflush/jet impingement method of regenerating fluid filter elements that is highly efficient. A vortex particle separator and particle trap were designed for zero-gravity use, and the zero-gravity test results are discussed. The filter regeneration unit was designed for both inflight maintenance and ground refurbishment use on space shuttle and future space missions.

  16. Analysis of the Thermal Load of Structural Elements High-Power DC Supply with the Transformer of Ripple Filter with Current Overload

    Directory of Open Access Journals (Sweden)

    Jaroslav Lokvenc

    2017-01-01

    Full Text Available Design of the high-power DC supply quite logically based on the required electrical parameters and expected or defined operating conditions. A prerequisite trouble-free operation is also the correct choice of construction materials. Both in terms of mechanical strength and stability, and in terms of thermal load. The article deals with thermal conditions in the high-power DC supply with the transformer of ripple filter for long-term current overload.

  17. High flow ceramic pot filters

    NARCIS (Netherlands)

    van Halem, D.; van der Laan, H.; Soppe, A. I.A.; Heijman, S.G.J.

    2017-01-01

    Ceramic pot filters are considered safe, robust and appropriate technologies, but there is a general consensus that water revenues are limited due to clogging of the ceramic element. The objective of this study was to investigate the potential of high flow ceramic pot filters to produce more

  18. Planetary Airplane Extraction System Development and Subscale Testing

    Science.gov (United States)

    Teter, John E., Jr.

    2006-01-01

    The Aerial Regional-scale Environmental Survey (ARES) project will employ an airplane as the science platform from which to collect science data in the previously inaccessible, thin atmosphere of Mars. In order for the airplane to arrive safely in the Martian atmosphere, a number of sequences must occur. A critical element in the entry sequence at Mars is an extraction maneuver to separate the airplane quickly (in less than a second) from its protective backshell to reduce the possibility of re-contact, potentially leading to mission failure. This paper describes the development, testing, and lessons learned from building a 1/3 scale model of this airplane extraction system. This design, based on the successful Mars Exploration Rover (MER) extraction mechanism, employs a series of trucks rolling along tracks located on the surface of the central parachute can. Numerous tests using high speed video were conducted at the Langley Research Center to validate this concept. One area of concern was that that although the airplane released cleanly, a pitching moment could be introduced. While targeted for a Mars mission, this concept will enable environmental surveys by aircraft in other planetary bodies with a sensible atmosphere such as Venus or Saturn's moon, Titan.

  19. Filter unit for use at high temperatures

    Science.gov (United States)

    Ciliberti, David F.; Lippert, Thomas E.

    1988-01-01

    A filtering unit for filtering particulates from high temperature gases uses a spiral ceramic spring to bias a ceramic, tubular filter element into sealing contact with a flange about an aperture of a metallic tube sheet. The ceramic spiral spring may contact the upper edge of the filter element and be restrained by a stop member spaced from one end of the tube sheet, or the spring may contact the bottom of the filter element and be restrained by a support member spaced from the opposite end of the tube sheet. The stop member and support member are adjustably secured to the tube sheet. A filtering system uses the ceramic spiral spring to bias a plurality of ceramic, tubular filter elements in a respective plurality of apertures in a tube sheet which divides a vessel into upper and lower enclosed sections.

  20. Properties of ceramic candle filters

    Energy Technology Data Exchange (ETDEWEB)

    Pontius, D.H.

    1995-06-01

    The mechanical integrity of ceramic filter elements is a key issue for hot gas cleanup systems. To meet the demands of the advanced power systems, the filter components must sustain the thermal stresses of normal operations (pulse cleaning), of start-up and shut-down conditions, and of unanticipated process upsets such as excessive ash accumulation without catastrophic failure. They must also survive the various mechanical loads associated with handling and assembly, normal operation, and process upsets. For near-term filter systems, these elements must survive at operating temperatures of 1650{degrees}F for three years.

  1. Filters in topology optimization

    DEFF Research Database (Denmark)

    Bourdin, Blaise

    1999-01-01

    In this article, a modified (``filtered'') version of the minimum compliance topology optimization problem is studied. The direct dependence of the material properties on its pointwise density is replaced by a regularization of the density field using a convolution operator. In this setting...... it is possible to establish the existence of solutions. Moreover, convergence of an approximation by means of finite elements can be obtained. This is illustrated through some numerical experiments. The ``filtering'' technique is also shown to cope with two important numerical problems in topology optimization...

  2. "Moved by the spirit": does spirituality moderate the interrelationships between subjective well-being subscales?

    Science.gov (United States)

    Schuurmans-Stekhoven, James

    2010-07-01

    Despite the recent escalation of research into the spirituality and well-being link, past efforts have been plagued by methodological problems. However, the potential for measurement error within psychometric instruments remains largely unexplored. After reviewing theory and evidence suggesting spirituality might represent an affective misattribution, moderation modeling-with each subjective well-being (SWB) subscale as a dependent variable as predicted by the remaining SWB subscales-is utilized to test the assumption of scale invariance. These interrelationships were shown to vary in conjunction with spirituality; that is the analysis revealed significant spirituality x subscale interactions. Importantly, in all models the spirituality main effect was either nonsignificant or accounted for by other predictors. In combination, the findings suggest the interrelationship between the subscales rather than the level of SWB varies systematically with spirituality and casts considerable doubt on the previously reported "belief-as-benefit" effect.

  3. Acidity of precipitation as influenced by the filtering of atmospheric sulphur and nitrogen compounds - its role in the element balance and effect on soil

    Science.gov (United States)

    Robert Mayer; Bernhard Ulrich

    1976-01-01

    The data presented here are based upon element balance investigations in a beech forest in Central Germany (Ellenberg 1971). Being located in an altitude of about 500 m above sea level with an annual precipitation of about 1000 mm, and an acid soil with loess as the main constituent, the test site represents a typical environment for many Central European forests....

  4. The Correlation of SCL-90-R Anxiety, Depression, Somatization Subscale Scores with Chronic Low Back Pain.

    Science.gov (United States)

    Adilay, Utku; Guclu, Bulent; Goksel, Murat; Keskil, Semih

    2017-02-07

    The aim of this study was to investigate the correlation of the Symptom Checklist-90-R (SCL-90-R) anxiety, depression, and somatization subscale scores with chronic low back pain. In this study, 75 patients admitted with the complaint of chronic low back pain (patient group) and 75 healthy persons (control group) were evaluated. SCL-90-R anxiety, depression, and somatization subscale scores of patients having chronic low back pain and healthy persons were measured. The mean values were paired and using two tailed t test they were statistically evaluated. The difference between SCL-90-R anxiety subscale subscores of patients having choronic low back pain and healthy persons was statistically non significant (p 0.05).The difference betweenSCL-90-R depression subscale subscores of patients having chronic low back pain and healthy persons was statistically non significant (p 0.05). The difference between SCL-90-R somatization subscale subscores of patients having chronic low back pain and healthy persons was statistically significant (p 0.05). Our data show that SCL-90-R somatization subscale subscores were higher in patients with low back pain. The treatment of low back pain can be more successful when combined with the treatment of somatization.

  5. The Subjective Index for Physical and Social Outcome (SIPSO in Stroke: investigation of its subscale structure

    Directory of Open Access Journals (Sweden)

    George Steve

    2010-04-01

    Full Text Available Abstract Background Short and valid measures of the impact of a stroke on integration are required in health and social settings. The Subjective Index of Physical and Social Outcome (SIPSO is one such measure. However, there are questions whether scores can be summed into a total score or whether subscale scores should be calculated. This paper aims to provide clarity on the internal construct validity of the subscales and the total scale. Methods SIPSO data were collected as part of two parallel surveys of the met and unmet needs of 445 younger people (aged 18-65 with non-recent stroke (at least one year and living at home. Factor, Mokken and Rasch analysis were used. Results Factor analysis supported a two factor structure (explaining 68% of the variance as did the Mokken analysis (overall Loevinger coefficient 0.77 for the Physical Integration subscale; 0.51 for the Social Integration subscale. Both subscales fitted the Rasch model (P > 0.01 after adjusting for some observed differential item functioning. The 10-items together did not fit the Rasch model. Conclusions The SIPSO subscales are valid for use with stroke patients of working age but the total SIPSO is not. The conversion table can be used by clinicians and researchers to convert ordinal data to interval level prior to mathematical operations and other parametric procedures. Further work is required to explore the occurrence of bias by gender for some of the items.

  6. HF filter design and computer simulation

    CERN Document Server

    Rhea, Randall W

    1994-01-01

    A book for engineers who design and build filters of all types, including lumped element, coaxial, helical, dielectric resonator, stripline and microstrip types. A thorough review of classic and modern filter design techniques, containing extensive practical design information of passband characteristics, topologies and transformations, component effects and matching. An excellent text for the design and construction of microstrip filters.

  7. Photographic filters

    Science.gov (United States)

    Rodigues, Jose Eduardo; Santosdealmeida, Wagner

    1987-12-01

    Some of the main aspects related to photographic filters are examined and prepared as a reference for researchers and students of remote sensing. A large range of information about the filters including their basic fundamentals, classification, and main types is presented. The theme cannot be exhausted in this or any other individual publication because of its great complexity, profound theoretical publication, and dynmaic technological development. The subject does not deal only with filter applications in remote sensing. As much as possible, additional information about the utilization of these products in other professional areas, as pictorial photography, photographic processing, and optical engineering, were included.

  8. Assessment of trace elements, POPs, (210)Po and stable isotopes ((15)N and (13)C) in a rare filter-feeding shark: The megamouth.

    Science.gov (United States)

    Moura, Jailson Fulgencio de; Merico, Agostino; Montone, Rosalinda Carmela; Silva, Josilene; Seixas, Tércia Guedes; Godoy, José Marcus de Oliveira; Saint'Pierre, Tatiana Dillenburg; Hauser-Davis, Rachel Ann; Di Beneditto, Ana Paula Madeira; Reis, Estéfane Cardinot; Tavares, Davi Castro; Lemos, Leila Soledade; Siciliano, Salvatore

    2015-06-15

    With less than 60 records being reported worldwide, the megamouth (Megachasma pelagios) is today one of the least known shark species inhabiting our oceans. Therefore, information concerning the biology and ecology of this enigmatic organism is very scarce and limited to feeding behaviour and preferred habitat. The present work reports new data on the concentrations of trace elements, organic mercury, POPs and (210)Po in hepatic and muscular tissues of a specimen found stranded in the southeastern coast of Brazil. Additionally, we provide new evidence based on stable isotope analysis (δ(15)N and δ(13)C) confirming the preference for the pelagic habitat and the zooplanktivorous feeding behaviour of the megamouth. These results are consistent with the low concentrations of organic pollutant compounds and other elements measured in our samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. High flow ceramic pot filters.

    Science.gov (United States)

    van Halem, D; van der Laan, H; Soppe, A I A; Heijman, S G J

    2017-11-01

    Ceramic pot filters are considered safe, robust and appropriate technologies, but there is a general consensus that water revenues are limited due to clogging of the ceramic element. The objective of this study was to investigate the potential of high flow ceramic pot filters to produce more water without sacrificing their microbial removal efficacy. High flow pot filters, produced by increasing the rice husk content, had a higher initial flow rate (6-19 L h-1), but initial LRVs for E. coli of high flow filters was slightly lower than for regular ceramic pot filters. This disadvantage was, however, only temporarily as the clogging in high flow filters had a positive effect on the LRV for E. coli (from below 1 to 2-3 after clogging). Therefore, it can be carefully concluded that regular ceramic pot filters perform better initially, but after clogging, the high flow filters have a higher flow rate as well as a higher LRV for E. coli. To improve the initial performance of new high flow filters, it is recommended to further utilize residence time of the water in the receptacle, since additional E. coli inactivation was observed during overnight storage. Although a relationship was observed between flow rate and LRV of MS2 bacteriophages, both regular and high flow filters were unable to reach over 2 LRV. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Subscales of the vestibular activities and participation questionnaire could be applied across cultures.

    Science.gov (United States)

    Mueller, Martin; Whitney, Susan L; Alghwiri, Alia; Alshebber, Kefah; Strobl, Ralf; Alghadir, Ahmad; Al-momani, Murad O; Furman, Joseph M; Grill, Eva

    2015-02-01

    The objective of this study was to assess the objectivity, cross-cultural validity, and convergent validity of the Vestibular Activities and Participation (VAP) questionnaire among four countries, Germany, United States, Jordan, and Saudi Arabia. This was a cross-sectional study conducted in four specialized outpatient dizziness clinics in Germany, United States, Jordan, and Saudi Arabia. A total of 453 participants were included in the study. The Rasch analysis revealed two separate subscales. Subscale 1 items included focusing attention, lying down, standing, bending, lifting and carrying objects, and sports. Subscale 2 items included walking long distances, climbing, running, moving around within buildings other than home, using transportation, and driving. The Pearson product-moment correlation between the Dizziness Handicap Inventory and the summary score of the VAP subscale 1 was 0.66 and was 0.64 for subscale 2. Owing to its shortness and intercultural adaptability, the new two-scale version of the VAP questionnaire lends itself to clinical practice and research across countries to estimate the effect of vertigo and dizziness on activity limitation and participation restrictions. Psychometrically sound summary scores can be calculated. More extended versions of the VAP can be used for comprehensive clinical assessment where summary scores are not needed or a more detailed documentation is warranted. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Effects of zinc supplementation on subscales of anorexia in children: A randomized controlled trial.

    Science.gov (United States)

    Khademian, Majid; Farhangpajouh, Neda; Shahsanaee, Armindokht; Bahreynian, Maryam; Mirshamsi, Mehran; Kelishadi, Roya

    2014-01-01

    This study aims to assess the effects of zinc supplementation on improving the appetite and its subscales in children. This study was conducted in 2013 in Isfahan, Iran. It had two phases. At the first step, after validation of the Child Eating Behaviour Questionaire (CEBQ), it was completed for 300 preschool children, who were randomly selected. The second phase was conducted as a randomized controlled trial. Eighty of these children were randomly selected, and were randomly assigned to two groups of equal number receiving zinc (10 mg/day) or placebo for 12 weeks. Overall 77 children completed the trial (39 in the case and 3 in the control group).The results showed that zinc supplement can improve calorie intake in children by affecting some CEBQ subscales like Emotional over Eating and Food Responsible. Zinc supplementation had positive impact in promoting the calorie intake and some subscales of anorexia.

  12. The patellofemoral pain and osteoarthritis subscale of the KOOS (KOOS-PF)

    DEFF Research Database (Denmark)

    Crossley, Kay M; Macri, Erin M; Cowan, Sallie M

    2017-01-01

    for patellofemoral pain have methodological limitations. This study aimed to develop a new subscale of the Knee injury and Osteoarthritis Outcome Score for patellofemoral pain and osteoarthritis (KOOS-PF), and evaluate its measurement properties. METHODS: Items were generated using input from 50 patients...... and interpretability of the final version of KOOS-PF and other KOOS subscales. RESULTS: From an initial 80 generated items, the final subscale included 11 items. KOOS-PF items loaded predominantly on one factor, pain during activities that load the patellofemoral joint. KOOS-PF had good internal consistency (Cronbach......'s α 0.86) and adequate test-retest reliability (intraclass correlation coefficient 0.86). Hypothesis testing supported convergent, divergent and known-groups validity. Responsiveness was confirmed, with KOOS-PF demonstrating a moderate correlation with Global Rating of Change scores (r 0.52) and large...

  13. Validation of the 4DSQ somatization subscale in the occupational health care setting as a screener.

    Science.gov (United States)

    de Vroege, Lars; Emons, Wilco H M; Sijtsma, Klaas; Hoedeman, Rob; van der Feltz-Cornelis, Christina M

    2015-03-01

    Somatoform disorders (physical symptoms without medical explanation that cause dysfunction) are prevalent in the occupational health (OH) care setting and are associated with functional impairment and absenteeism. Availability of psychometric instruments aimed at assessing somatoform disorders is limited. In the OH setting, so far only the Patient-Health-Questionnaire 15 has been validated as screener for somatoform disorder, and has been shown to have moderate validity. The Four-Dimensional Symptom Questionnaire (4DSQ) is frequently used in the OH setting but the Somatization subscale is not validated yet. The aim of this study is to validate the 4DSQ Somatization subscale as screener for DSM-IV somatoform disorder in the OH setting by using the MINI interview as gold standard. Employees absent from work due to physical symptoms, for a period longer than 6 weeks and shorter than 2 years, were asked to participate in this study. They filled out the 4DSQ and underwent a MINI interview by telephone for DSM-IV classification. Specificity and sensitivity scores were calculated for all possible cut-off scores and a receiver operator curve was computed for the Somatization subscale. 95 % confidence intervals (95 % CIs) were calculated for sensitivity and specificity. The Somatization subscale of the 4DSQ has an optimal cut point of 9, with specificity and sensitivity equal to 64.3 % [95 % CI (53.6; 73.7 %)] and 60.9 % [95 % CI (40.8; 77.8 %)], respectively. Receiver operator curves showed an area under the curve equal to 0.61 [SE = 0.07; 95 % CI (0.48; 0.75)] for the Somatization subscale of the 4DSQ. The 4DSQ Somatization subscale is a questionnaire of moderate sensitivity and specificity.

  14. Water Filters

    Science.gov (United States)

    1988-01-01

    Seeking to find a more effective method of filtering potable water that was highly contaminated, Mike Pedersen, founder of Western Water International, learned that NASA had conducted extensive research in methods of purifying water on board manned spacecraft. The key is Aquaspace Compound, a proprietary WWI formula that scientifically blends various types of glandular activated charcoal with other active and inert ingredients. Aquaspace systems remove some substances; chlorine, by atomic adsorption, other types of organic chemicals by mechanical filtration and still others by catalytic reaction. Aquaspace filters are finding wide acceptance in industrial, commercial, residential and recreational applications in the U.S. and abroad.

  15. Filter apparatus

    Science.gov (United States)

    Kuban, D.P.; Singletary, B.H.; Evans, J.H.

    A plurality of holding tubes are respectively mounted in apertures in a partition plate fixed in a housing receiving gas contaminated with particulate material. A filter cartridge is removably held in each holding tube, and the cartridges and holding tubes are arranged so that gas passes through apertures therein and across the the partition plate while particulate material is collected in the cartridges. Replacement filter cartridges are respectively held in holding canisters mounted on a support plate which can be secured to the aforesaid housing, and screws mounted on said canisters are arranged to push replacement cartridges into the cartridge holding tubes and thereby eject used cartridges therefrom.

  16. Method of silicon filter refining from harmful impurities

    Directory of Open Access Journals (Sweden)

    A. D. Mekhtiyev

    2016-10-01

    Full Text Available In the article there are considered the types of filters used for silicon refinement, the possibilities of mechanical separation of inclusions when the melt is through the filter, the efficiency of silicon refinement from impurities. There are also considered the advantages of bulk granular filters which consist of the lumpy or granulated elements. There are described the methods of obtaining filtering elements, the functions executed by the filters depending on their type. There are presented the analysis results obtained in filter refinement of silicon which show the impact of different filters materials on the content of impurities.

  17. Removal of residual particulate matter from filter media

    Energy Technology Data Exchange (ETDEWEB)

    Almlie, Jay C.; Miller, Stanley J.

    2018-01-09

    A method for removing residual filter cakes that remain adhered to a filter after typical particulate removal methodologies have been employed, such as pulse-jet filter element cleaning, for all cleanable filters used for air pollution control, dust control, or powder control.

  18. Filter This

    Directory of Open Access Journals (Sweden)

    Audrey Barbakoff

    2011-03-01

    Full Text Available In the Library with the Lead Pipe welcomes Audrey Barbakoff, a librarian at the Milwaukee Public Library, and Ahniwa Ferrari, Virtual Experience Manager at the Pierce County Library System in Washington, for a point-counterpoint piece on filtering in libraries. The opinions expressed here are those of the authors, and are not endorsed by their employers. [...

  19. Carbon and nitrogen elemental and isotopic ratios of filter-feeding bivalves along the French coasts: An assessment of specific, geographic, seasonal and multi-decadal variations.

    Science.gov (United States)

    Briant, Nicolas; Savoye, Nicolas; Chouvelon, Tiphaine; David, Valérie; Rodriguez, Samuel; Charlier, Karine; Sonke, Jeroen E; Chiffoleau, Jean François; Brach-Papa, Christophe; Knoery, Joël

    2018-02-01

    Primary consumers play a key role in coastal ecosystems by transferring organic matter from primary producers to predators. Among them, suspension-feeders, like bivalve molluscs are widely used in trophic web studies. The main goal of this study was to investigate variations of C and N elemental and isotopic ratios in common bivalves (M. edulis, M. galloprovincialis, and C. gigas) at large spatial (i.e. among three coastal regions) and different temporal (i.e. from seasonal to multi-decadal) scales in France, in order to identify potential general or specific patterns and speculate on their drivers. The observed spatial variability was related to the trophic status of the coastal regions (oligotrophic Mediterranean Sea versus meso- to eutrophic English Channel and Atlantic ocean), but not to ecosystem typology (estuaries, versus lagoons versus bays versus littoral systems). Furthermore, it highlighted local specificities in terms of the origin of the POM assimilated by bivalves (e.g., mainly continental POM vs. marine phytoplankton vs. microphytobenthic algae). Likewise, seasonal variability was related both to the reproduction cycle for C/N ratios of Mytilus spp. and to changes in trophic resources for δ(13)C of species located close to river mouth. Multi-decadal evolution exhibited shifts and trends for part of the 30-year series with decreases in δ(13)C and δ(15)N. Specifically, shifts appeared in the early 2000's, likely linking bivalve isotopic ratios to a cascade of processes affected by local drivers. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Comparison of Child Behavior Checklist subscales in screening for obsessive-compulsive disorder

    DEFF Research Database (Denmark)

    Andersen, Pia Aaron Skovby; Bilenberg, Niels

    2012-01-01

    Obsessive-compulsive disorder (OCD) is a prevalent psychiatric disorder in children and adolescents associated with significant functional impairment. Early and correct diagnosis is essential for an optimal treatment outcome. The purpose of this study was to determine which of four subscales...... derived from the Child Behavior Checklist best discriminates OCD patients from clinical and population-based controls....

  1. Analysis of the Subscales of the Tennessee Self-Concept Scale.

    Science.gov (United States)

    Gellen, Murray I.; Hoffman, Roy A.

    1984-01-01

    Factor analyzed the item responses comprising each of the five external dimensions and the three internal dimensions of the Tennessee Self-Concept Scale. The results indicated that seven of the eight subscales are essentially single-factor scales. Implications for counseling are discussed. (Author)

  2. Evaluation of the Construction of the Subscales for the Piers-Harris and Tennessee Inventories.

    Science.gov (United States)

    Thomas, Julia Anne

    A sample of 234 fifth- and 259 sixth-grade students scaled the items of the Piers-Harris, Tennessee, Coopersmith, and Lipsett self-concept measures. The scaling of the Piers-Harris and the Tennessee inventories was examined in reference to their subscales. The present technique placed items on a bivariate plane of two orthogonal dimensions…

  3. Development and validation of the functional assessment of cancer therapy-antiangiogenesis subscale.

    Science.gov (United States)

    Kaiser, Karen; Beaumont, Jennifer L; Webster, Kimberly; Yount, Susan E; Wagner, Lynne I; Kuzel, Timothy M; Cella, David

    2015-05-01

    The Functional Assessment of Cancer Therapy (FACT)-Antiangiogenesis (AntiA) Subscale was developed and validated to enhance treatment decision-making and side effect management for patients receiving anti-angiogenesis therapies. Side effects related to anti-angiogenesis therapies were identified from the literature, clinician input, and patient input. Fifty-nine possible patient expressions of side effects were generated. Patient and clinician ratings of the importance of these expressions led us to develop a 24-item questionnaire with clinical and research potential. To assess the scale's reliability and validity, 167 patients completed the AntiA Subscale, the Functional Assessment of Cancer Therapy-general (FACT-G), the FACT-Kidney Symptom Index (FKSI), the FACIT-Fatigue Subscale, the Global Rating of Change Scale (GRC), and the PROMIS Global Health Scale. Patient responses to the AntiA were analyzed for internal consistency, test-retest reliability, convergent and discriminant validity, and responsiveness to change in clinical status. All tested scales were found to have good internal consistency reliability (Cronbach's alpha 0.70-0.92). Test-retest reliability was also good (0.72-0.88) for total and subscale scores and lower for individual items. The total score, subscale scores, and all single items (except nosebleeds) significantly differentiated between groups defined by level of side effect bother. Evaluation of responsiveness to change in this study was not conclusive, suggesting an area for further research. The AntiA is a reliable and valid measure of side effects from anti-angiogenesis therapy. © 2014 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  4. Development and validation of the functional assessment of cancer therapy–antiangiogenesis subscale

    Science.gov (United States)

    Kaiser, Karen; Beaumont, Jennifer L; Webster, Kimberly; Yount, Susan E; Wagner, Lynne I; Kuzel, Timothy M; Cella, David

    2015-01-01

    The Functional Assessment of Cancer Therapy (FACT)–Antiangiogenesis (AntiA) Subscale was developed and validated to enhance treatment decision-making and side effect management for patients receiving anti-angiogenesis therapies. Side effects related to anti-angiogenesis therapies were identified from the literature, clinician input, and patient input. Fifty-nine possible patient expressions of side effects were generated. Patient and clinician ratings of the importance of these expressions led us to develop a 24-item questionnaire with clinical and research potential. To assess the scale's reliability and validity, 167 patients completed the AntiA Subscale, the Functional Assessment of Cancer Therapy-general (FACT-G), the FACT-Kidney Symptom Index (FKSI), the FACIT-Fatigue Subscale, the Global Rating of Change Scale (GRC), and the PROMIS Global Health Scale. Patient responses to the AntiA were analyzed for internal consistency, test–retest reliability, convergent and discriminant validity, and responsiveness to change in clinical status. All tested scales were found to have good internal consistency reliability (Cronbach's alpha 0.70–0.92). Test–retest reliability was also good (0.72–0.88) for total and subscale scores and lower for individual items. The total score, subscale scores, and all single items (except nosebleeds) significantly differentiated between groups defined by level of side effect bother. Evaluation of responsiveness to change in this study was not conclusive, suggesting an area for further research. The AntiA is a reliable and valid measure of side effects from anti-angiogenesis therapy. PMID:25619758

  5. Space Launch System Base Heating Test: Sub-Scale Rocket Engine/Motor Design, Development and Performance Analysis

    Science.gov (United States)

    Mehta, Manish; Seaford, Mark; Kovarik, Brian; Dufrene, Aaron; Solly, Nathan; Kirchner, Robert; Engel, Carl D.

    2014-01-01

    The Space Launch System (SLS) base heating test is broken down into two test programs: (1) Pathfinder and (2) Main Test. The Pathfinder Test Program focuses on the design, development, hot-fire test and performance analyses of the 2% sub-scale SLS core-stage and booster element propulsion systems. The core-stage propulsion system is composed of four gaseous oxygen/hydrogen RS-25D model engines and the booster element is composed of two aluminum-based model solid rocket motors (SRMs). The first section of the paper discusses the motivation and test facility specifications for the test program. The second section briefly investigates the internal flow path of the design. The third section briefly shows the performance of the model RS-25D engines and SRMs for the conducted short duration hot-fire tests. Good agreement is observed based on design prediction analysis and test data. This program is a challenging research and development effort that has not been attempted in 40+ years for a NASA vehicle.

  6. Digital filters

    CERN Document Server

    Hamming, Richard W

    1997-01-01

    Digital signals occur in an increasing number of applications: in telephone communications; in radio, television, and stereo sound systems; and in spacecraft transmissions, to name just a few. This introductory text examines digital filtering, the processes of smoothing, predicting, differentiating, integrating, and separating signals, as well as the removal of noise from a signal. The processes bear particular relevance to computer applications, one of the focuses of this book.Readers will find Hamming's analysis accessible and engaging, in recognition of the fact that many people with the s

  7. Thermodynamic analysis and subscale modeling of space-based orbit transfer vehicle cryogenic propellant resupply

    Science.gov (United States)

    Defelice, David M.; Aydelott, John C.

    1987-01-01

    The resupply of the cryogenic propellants is an enabling technology for spacebased orbit transfer vehicles. As part of the NASA Lewis ongoing efforts in microgravity fluid management, thermodynamic analysis and subscale modeling techniques were developed to support an on-orbit test bed for cryogenic fluid management technologies. Analytical results have shown that subscale experimental modeling of liquid resupply can be used to validate analytical models when the appropriate target temperature is selected to relate the model to its prototype system. Further analyses were used to develop a thermodynamic model of the tank chilldown process which is required prior to the no-vent fill operation. These efforts were incorporated into two FORTRAN programs which were used to present preliminary analyticl results.

  8. Filtered or Unfiltered?

    Science.gov (United States)

    Curry, Ann; Haycock, Ken

    2001-01-01

    Discusses results of a survey questionnaire of public and school libraries that investigated the use of Internet filtering software. Considers filter alternatives; reasons for filtering or not filtering; brand names; satisfaction with site blocking; satisfaction with the decision to install filter software; and guidelines for considering filters.…

  9. Electronically Tunable Resistorless Mixed Mode Biquad Filters

    OpenAIRE

    Yesil, A.; Kacar, F.

    2013-01-01

    This paper presents a new realization of elec¬tronically tunable mixed mode (including transadmittance- and voltage-modes) biquad filter with single input, three outputs or three inputs, single output using voltage differ-encing transconductance amplifier (VDTA), a recently introduced active element. It can simultaneously realize standard filtering signals: low-pass, band-pass and high-pass or by selecting input terminals, it can realize all five different filtering signals: low-pass, band-pa...

  10. Exploring measurement invariance by gender in the profile of mood states depression subscale among cancer survivors.

    Science.gov (United States)

    Kim, Jihye; Smith, Tenbroeck

    2017-01-01

    The Profile of Mood States-Short Form (POMS-SF) is a well-validated tool commonly used in medical/clinical research. Less attention has been paid to the measurement invariance of the POMS-the degree to which the structure and items behave similarly for different groups (e.g., women and men). This study investigated the measurement invariance of the POMS Depression subscale across gender groups in a sample of cancer survivors. The POMS Depression subscale has 8 items (Unhappy, Sad, Blue, Hopeless, Discouraged, Miserable, Helpless, and Worthless). Invariance was measured using multigroup confirmatory factor analysis. This study used data from American Cancer Society Studies of Cancer Survivors-II, a population-based survey of adult cancer survivors (n = 9170). We found factor structures and factor loadings were invariant for gender groups, but moderate differential item functioning (DIF) in the question containing the word blue. With regard to cancer survivors' gender, we found the Depression subscale of the POMS-SF had configural invariance, and partial metric and scalar invariance. This suggests that results should be interpreted with caution, especially when gender is considered important. More broadly, our finding suggests that questions with the word blue may introduce DIF into other measures of depressive mood. More research is needed to replicate these findings in other samples and with other instruments.

  11. Qualification Lab Testing on M1 Abrams Engine Oil Filters

    Science.gov (United States)

    2016-11-01

    TEST SYSTEM P/N: Flow Rate: GPM Element ID: Initial Volume: L Housing ID: Final Volume: L Element Type: Min. Element Bubble Point: in. H2O UPSTREAM...assemblies were assessed for qualification using the already qualified Purolator oil filter assembly as a baseline. 15. SUBJECT TERMS M-1, oil...HF28202 oil filter assemblies were assessed for qualification using the already qualified Purolator oil filter assembly as a baseline. The Donaldson

  12. Childhood depression subscales using repeated sessions on Children's Depression Rating Scale - revised (CDRS-R) scores.

    Science.gov (United States)

    Isa, Ameena; Bernstein, Ira; Trivedi, Madhukar; Mayes, Taryn; Kennard, Betsy; Emslie, Graham

    2014-08-01

    Although acute treatments have been shown to be effective in treating early-onset depression, only one-third or thereabouts reach a remission within 3 months. Unfortunately, delayed time to remission in early-onset depression leads to poorer therapeutic outcomes. Clearly, there is a need to identify, diagnose, and provide effective treatment of a depressed patient quickly. A sophisticated understanding of depression subscales and their change over time with treatment could enhance pathways to individualized treatment approaches for childhood depression. Previous studies have found that the clinician-measured instrument, Children's Depression Rating Scale-Revised (CDRS-R) measures multiple subscales (or components) of depression. The aim of this study was to see how these subscales may change over the course of a 12-week study. This knowledge will help determine if dimensions/subscales of childhood depression (paralleling the adult literature) using the subscales derived from factor analysis procedure is useful. We examined two clinical trials in which youth (n=234) with major depressive disorder (MDD) were treated openly with fluoxetine for eight sessions spread over 12 weeks. The CDRS-R was completed based on clinician interviews with parent and child at each session. Classical test theory and component analysis with associated parallel analysis (oblique rotation) were conducted on each week's scores. Although more factors were needed for the baseline and first two therapy sessions, a two-factor solution sufficed thereafter. Depressed facial affect, listless speech, and hypoactivity best defined Factor I, whereas sleep problems, appetite disturbance, physical symptoms, irritability, guilt, and weeping best defined Factor II. All other symptoms cross-loaded almost equally on the two factors. The scale's reliability (internal consistency) improved from baseline to exit sessions (α=0.65-0.91). As a result, the clinicians' assessments of the various symptoms became

  13. The Novel Microwave Stop-Band Filter

    Directory of Open Access Journals (Sweden)

    R. E. Chernobrovkin

    2008-01-01

    Full Text Available The stop-band filter with the new band-rejection element is proposed. The element is a coaxial waveguide with the slot in the centre conductor. In the frame of this research, the numerical and experimental investigations of the amplitude-frequency characteristics of the filter are carried out. It is noted that according to the slot parameters the two typical resonances (half-wave and quarter-wave can be excited. The rejection band of the single element is defined by the width, depth, and dielectric filling of the slot. Fifth-order Chebyshev filter utilizing the aforementioned element is also synthesized, manufactured, and tested. The measured and simulated results are in good agreement. The experimental filter prototype exhibits the rejection band 0.86 GHz at the level −40 dB.

  14. Relating Unidimensional IRT Parameters to a Multidimensional Response Space: A Review of Two Alternative Projection IRT Models for Scoring Subscales

    Science.gov (United States)

    Kahraman, Nilufer; Thompson, Tony

    2011-01-01

    A practical concern for many existing tests is that subscore test lengths are too short to provide reliable and meaningful measurement. A possible method of improving the subscale reliability and validity would be to make use of collateral information provided by items from other subscales of the same test. To this end, the purpose of this article…

  15. Nonlinear Filtering

    Science.gov (United States)

    1975-07-01

    ELEMENT, PPOJECT. TASK AREA 4 WORK UNIT NUMBERS 61102F 9769-01 tZ. REPORT DATE July 1975 U. NUMBER OF PAGES IS. SECURITY CLASS , (ol Ulli...461. This s t udy used a serial nachin~ to simulate a contemporary h· tlrl d system with 1·lOBSSL as the sirnulcttion langu •ge. The results

  16. Structured filtering

    Science.gov (United States)

    Granade, Christopher; Wiebe, Nathan

    2017-08-01

    A major challenge facing existing sequential Monte Carlo methods for parameter estimation in physics stems from the inability of existing approaches to robustly deal with experiments that have different mechanisms that yield the results with equivalent probability. We address this problem here by proposing a form of particle filtering that clusters the particles that comprise the sequential Monte Carlo approximation to the posterior before applying a resampler. Through a new graphical approach to thinking about such models, we are able to devise an artificial-intelligence based strategy that automatically learns the shape and number of the clusters in the support of the posterior. We demonstrate the power of our approach by applying it to randomized gap estimation and a form of low circuit-depth phase estimation where existing methods from the physics literature either exhibit much worse performance or even fail completely.

  17. Item-level and subscale-level factoring of Biggs' Learning Process Questionnaire (LPQ) in a mainland Chinese sample.

    Science.gov (United States)

    Sachs, J; Gao, L

    2000-09-01

    The learning process questionnaire (LPQ) has been the source of intensive cross-cultural study. However, an item-level factor analysis of all the LPQ items simultaneously has never been reported. Rather, items within each subscale have been factor analysed to establish subscale unidimensionality and justify the use of composite subscale scores. It was of major interest to see if the six logically constructed items groups of the LPQ would be supported by empirical evidence. Additionally, it was of interest to compare the consistency of the reliability and correlational structure of the LPQ subscales in our study with those of previous cross-cultural studies. Confirmatory factor analysis was used to fit the six-factor item level model and to fit five representative subscale level factor models. A total of 1070 students between the ages of 15 to 18 years was drawn from a representative selection of 29 classes from within 15 secondary schools in Guangzhou, China. Males and females were almost equally represented. The six-factor item level model of the LPQ seemed to fit reasonably well, thus supporting the six dimensional structure of the LPQ and justifying the use of composite subscale scores for each LPQ dimension. However, the reliability of many of these subscales was low. Furthermore, only two subscale-level factor models showed marginally acceptable fit. Substantive considerations supported an oblique three-factor model. Because the LPQ subscales often show low internal consistency reliability, experimental and correlational studies that have used these subscales as dependent measures have been disappointing. It is suggested that some LPQ items should be revised and other items added to improve the inventory's overall psychometric properties.

  18. Solc filters in a reflective geometry

    Science.gov (United States)

    Messaadi, Abdelghafour; Vargas, Asticio; Sánchez-López, María M.; García-Martínez, Pascuala; Kula, Przemysław; Bennis, Noureddine; Moreno, Ignacio

    2017-04-01

    We present the realization of a bulk optics birefringent Solc filter in a reflective geometry. This geometry reduces by half the number of required retarders, ensures the same spectral retardance function in pairs of retarders, and helps to make more compact filters. The key element is a quarter-wave Fresnel rhomb located in between the set of retarders and a mirror. Two cases are considered: the first Solc filter uses multiple-order quartz retarders, and the second one uses two liquid-crystal retarders. The latter has the advantage of being tunable via an applied voltage. Experimental results show how to filter the spectral content of a supercontinuum laser.

  19. Bites of Lists - mapping and filtering sublists

    DEFF Research Database (Denmark)

    Nørmark, Kurt

    The idea of applying map and filter functions on consecutive sublists instead of on individual list elements is discussed and developed in this paper. A non-empty, consecutive sublist is called a bite. Both map and filter functions accept a function parameter - a bite function - which...... is responsible for returning a prefix bite of a list. We develop families of bite functions via a collection of higher-order bite generators. On top of the bite generators, a number of bite mapping and bite filtering functions are introduced. We illustrate the usefulness of bite mapping and filtering via...

  20. Subscales of the Barratt Impulsiveness Scale differentially relate to the Big Five factors of personality.

    Science.gov (United States)

    Lange, Florian; Wagner, Adina; Müller, Astrid; Eggert, Frank

    2017-06-01

    The place of impulsiveness in multidimensional personality frameworks is still unclear. In particular, no consensus has yet been reached with regard to the relation of impulsiveness to Neuroticism and Extraversion. We aim to contribute to a clearer understanding of these relationships by accounting for the multidimensional structure of impulsiveness. In three independent studies, we related the subscales of the Barratt Impulsiveness Scale (BIS) to the Big Five factors of personality. Study 1 investigated the associations between the BIS subscales and the Big Five factors as measured by the NEO Five-Factor Inventory (NEO-FFI) in a student sample (N = 113). Selective positive correlations emerged between motor impulsiveness and Extraversion and between attentional impulsiveness and Neuroticism. This pattern of results was replicated in Study 2 (N = 132) using a 10-item short version of the Big Five Inventory. In Study 3, we analyzed BIS and NEO-FFI data obtained from a sample of patients with pathological buying (N = 68). In these patients, the relationship between motor impulsiveness and Extraversion was significantly weakened when compared to the non-clinical samples. At the same time, the relationship between attentional impulsiveness and Neuroticism was substantially stronger in the clinical sample. Our studies highlight the utility of the BIS subscales for clarifying the relationship between impulsiveness and the Big Five personality factors. We conclude that impulsiveness might occupy multiple places in multidimensional personality frameworks, which need to be specified to improve the interpretability of impulsiveness scales. © 2017 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  1. Convergent Filter Bases

    Directory of Open Access Journals (Sweden)

    Coghetto Roland

    2015-09-01

    Full Text Available We are inspired by the work of Henri Cartan [16], Bourbaki [10] (TG. I Filtres and Claude Wagschal [34]. We define the base of filter, image filter, convergent filter bases, limit filter and the filter base of tails (fr: filtre des sections.

  2. Using data from Multidimensional Pain Inventory subscales to assess functioning in pain rehabilitation

    DEFF Research Database (Denmark)

    Harlacher, Uwe; Persson, Ann L; Rivano-Fischer, Marcelo

    2011-01-01

    The aim of this study was to examine whether Multidimensional Pain Inventory (MPI) subscale score changes can be used for monitoring interdisciplinary cognitive behavioural pain rehabilitation programmes, using the Psychological General Well-Being (PGWB) index as an independent variable...... of rehabilitation outcome. Data from 434 consecutively referred patients disabled by chronic pain were analysed. The intervention was a 4-week interdisciplinary pain rehabilitation group programme (5 h/day), based on biopsychosocial and cognitive behavioural principles. Mean PGWB total scores improved after...... rehabilitation (P...

  3. ADVANCED HOT GAS FILTER DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    E.S. Connolly; G.D. Forsythe

    2000-09-30

    DuPont Lanxide Composites, Inc. undertook a sixty-month program, under DOE Contract DEAC21-94MC31214, in order to develop hot gas candle filters from a patented material technology know as PRD-66. The goal of this program was to extend the development of this material as a filter element and fully assess the capability of this technology to meet the needs of Pressurized Fluidized Bed Combustion (PFBC) and Integrated Gasification Combined Cycle (IGCC) power generation systems at commercial scale. The principal objective of Task 3 was to build on the initial PRD-66 filter development, optimize its structure, and evaluate basic material properties relevant to the hot gas filter application. Initially, this consisted of an evaluation of an advanced filament-wound core structure that had been designed to produce an effective bulk filter underneath the barrier filter formed by the outer membrane. The basic material properties to be evaluated (as established by the DOE/METC materials working group) would include mechanical, thermal, and fracture toughness parameters for both new and used material, for the purpose of building a material database consistent with what is being done for the alternative candle filter systems. Task 3 was later expanded to include analysis of PRD-66 candle filters, which had been exposed to actual PFBC conditions, development of an improved membrane, and installation of equipment necessary for the processing of a modified composition. Task 4 would address essential technical issues involving the scale-up of PRD-66 candle filter manufacturing from prototype production to commercial scale manufacturing. The focus would be on capacity (as it affects the ability to deliver commercial order quantities), process specification (as it affects yields, quality, and costs), and manufacturing systems (e.g. QA/QC, materials handling, parts flow, and cost data acquisition). Any filters fabricated during this task would be used for product qualification tests

  4. Acoustic bandpass filters employing shaped resonators

    Science.gov (United States)

    Červenka, M.; Bednařík, M.

    2016-11-01

    This work deals with acoustic bandpass filters realized by shaped waveguide-elements inserted between two parts of an acoustic transmission line with generally different characteristic impedance. It is shown that the formation of a wide passband is connected with the eigenfrequency spectrum of the filter element which acts as an acoustic resonator and that the required filter shape substantially depends on whether the filter characteristic impedance is higher or lower than the characteristic impedance of the waveguide. It is further shown that this class of filters can be realized even without the need of different characteristic impedance. A heuristic technique is proposed to design filter shapes with required transmission properties; it is employed for optimization of low-frequency bandpass filters as well as for design of bandpass filters with wide passband surrounded by wide stopbands as it is typical for phononic crystals, however, in this case the arrangement is much simpler as it consists of only one simple-shaped homogeneous element.

  5. Digital notch filter based active damping for LCL filters

    DEFF Research Database (Denmark)

    Yao, Wenli; Yang, Yongheng; Zhang, Xiaobin

    2015-01-01

    LCL filters are widely used in Pulse Width Modulation (PWM) inverters. However, it also introduces a pair of unstable resonant poles that may challenge the controller stability. The passive damping is a convenient possibility to tackle the resonance problem at the cost of system overall efficiency....... In contrast, the active damping does not require any dissipation elements, and thus has become of increasing interest. As a result, a vast of active damping solutions have been reported, among which multi-loop control systems and additional sensors are necessary, leading to increased cost and complexity....... In this paper, a notch filter based active damping without the requirement of additional sensors is proposed, where the inverter current is employed as the feedback variable. Firstly, a design method of the notch filter for active damping is presented. The entire system stability has then been investigated...

  6. Optimal Gaussian Filter for Effective Noise Filtering

    OpenAIRE

    Kopparapu, Sunil; Satish, M

    2014-01-01

    In this paper we show that the knowledge of noise statistics contaminating a signal can be effectively used to choose an optimal Gaussian filter to eliminate noise. Very specifically, we show that the additive white Gaussian noise (AWGN) contaminating a signal can be filtered best by using a Gaussian filter of specific characteristics. The design of the Gaussian filter bears relationship with the noise statistics and also some basic information about the signal. We first derive a relationship...

  7. Numerical Simulations of Subscale Wind Turbine Rotor Inboard Airfoils at Low Reynolds Number

    Energy Technology Data Exchange (ETDEWEB)

    Blaylock, Myra L. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Thermal/ Fluid Sciences & Engineering Dept.; Maniaci, David Charles [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Wind Energy Technologies Dept.; Resor, Brian R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Wind Energy Technologies Dept.

    2015-04-01

    New blade designs are planned to support future research campaigns at the SWiFT facility in Lubbock, Texas. The sub-scale blades will reproduce specific aerodynamic characteristics of utility-scale rotors. Reynolds numbers for megawatt-, utility-scale rotors are generally above 2-8 million. The thickness of inboard airfoils for these large rotors are typically as high as 35-40%. The thickness and the proximity to three-dimensional flow of these airfoils present design and analysis challenges, even at the full scale. However, more than a decade of experience with the airfoils in numerical simulation, in the wind tunnel, and in the field has generated confidence in their performance. Reynolds number regimes for the sub-scale rotor are significantly lower for the inboard blade, ranging from 0.7 to 1 million. Performance of the thick airfoils in this regime is uncertain because of the lack of wind tunnel data and the inherent challenge associated with numerical simulations. This report documents efforts to determine the most capable analysis tools to support these simulations in an effort to improve understanding of the aerodynamic properties of thick airfoils in this Reynolds number regime. Numerical results from various codes of four airfoils are verified against previously published wind tunnel results where data at those Reynolds numbers are available. Results are then computed for other Reynolds numbers of interest.

  8. Changes to the subscales of two vision-related quality of life questionnaires are proposed.

    Science.gov (United States)

    de Boer, Michiel R; de Vet, Henrica C W; Terwee, Caroline B; Moll, Annette C; Völker-Dieben, Hennie J M; van Rens, Ger H M B

    2005-12-01

    Psychometrically sound questionnaires for the assessment of vision-related quality of life (QOL) are scarce. Therefore, the objective was to further validate two vision-related QOL questionnaires in a Dutch population of visually impaired elderly. A total of 329 visually impaired older persons referred to low vision services completed the low vision QOL (LVQOL) and Vision-Related Quality of Life Core Measure (VCM1) questionnaires at baseline, after 1-4 weeks (retest), and after 5 months. Confirmatory factor analyses were performed on baseline data. The smallest detectable change (SDC) was assessed, based on the standard error of measurement (SEM). Change scores between the baseline and 5 months follow-up data were related to a general transition question to assess the minimal important change (MIC). Furthermore, the MIC was related to the SDC, to examine whether the MICs were detectable beyond measurement error. The original factor structures could not be confirmed. After omitting items and remodeling, adequate fits were obtained. SDCs comprised at least one quarter of the scale for all scales and subscales on the individual level and exceeded the MICs on every occasion. We propose MICs of 5-10 points for the scales and subscales of the LVQOL and VCM1. The questionnaires are not useful in the follow-up of individual patients.

  9. Practical Application of a Subscale Transport Aircraft for Flight Research in Control Upset and Failure Conditions

    Science.gov (United States)

    Cunningham, Kevin; Foster, John V.; Morelli, Eugene A.; Murch, Austin M.

    2008-01-01

    Over the past decade, the goal of reducing the fatal accident rate of large transport aircraft has resulted in research aimed at the problem of aircraft loss-of-control. Starting in 1999, the NASA Aviation Safety Program initiated research that included vehicle dynamics modeling, system health monitoring, and reconfigurable control systems focused on flight regimes beyond the normal flight envelope. In recent years, there has been an increased emphasis on adaptive control technologies for recovery from control upsets or failures including damage scenarios. As part of these efforts, NASA has developed the Airborne Subscale Transport Aircraft Research (AirSTAR) flight facility to allow flight research and validation, and system testing for flight regimes that are considered too risky for full-scale manned transport airplane testing. The AirSTAR facility utilizes dynamically-scaled vehicles that enable the application of subscale flight test results to full scale vehicles. This paper describes the modeling and simulation approach used for AirSTAR vehicles that supports the goals of efficient, low-cost and safe flight research in abnormal flight conditions. Modeling of aerodynamics, controls, and propulsion will be discussed as well as the application of simulation to flight control system development, test planning, risk mitigation, and flight research.

  10. The use of Spielberger's State-Trait Personality Inventory (trait anxiety subscale) with naval subaquatic specialists.

    Science.gov (United States)

    Van Wijk, Charles H

    2014-12-01

    Panic behavior poses a particular threat to the health and safety of subaquatic occupational specialists. Trait anxiety has previously been identified as a marker of panic behavior under water, and Spielberger's State-Trait Personality Inventory (trait anxiety subscale) has been previously used to measure trait anxiety among subaquatic specialists. Using archived data, the trait anxiety scores of subaquatic specialists were analyzed to meet 3 objectives: 1stly - to develop a trait anxiety profile of subaquatic specialists; 2ndly - to investigate the predictive value of trait anxiety measures upon entering an occupational field; and 3rdly - to establish the reliability of these scores over time. Archival trait-anxiety data from 322 subjects were analyzed statistically. Analysis of the available scores revealed a highly homogenous as well as a very low trait anxiety profile for the investigated occupational group. Additionally, low trait anxiety was somewhat associated with success during specialist training: fewer candidates with high trait anxiety scores completed their qualification. Moreover, measurement of trait anxiety was stable over time, which suggests that when scores for this occupational group are screened, deviations from previous scores could signify a potential need for referral to an intervention from health professionals. Using the trait anxiety subscale as part of occupational health surveillance of subaquatic specialists could support prevention of accidents by identifying high-risk candidates during their annual health assessments, and referral for timeous intervention.

  11. Topographic effect of Sub-scale Mountains around the main Tibetan Plateau on Asian climate

    Science.gov (United States)

    Sha, Yingying; Shi, Zhengguo

    2017-04-01

    As one of the most important tectonic events in Cenozoic, the uplift of the Tibetan Plateau (TP) is considered to have profound influences on the evolution of Asian climate.However, the potential influence from the sub-scale mountains around the main TP is largely neglected. In actual, these sub-scale mountains may affect some climate systems, which facilitates from their sensitive locations. Taking the Mongolian Plateau (MP) and Yunnan-Guizhou Plateau (YGP, SW China) as examples, they are located at the core paths of mid-latitude winter westerly and Indian summer southwesterly monsoon, respectively, and seem to significantly block the eastward propagation of these systems from modern climatological data. In this study, general circulation model experiments with and without mountains are employed to evaluate the topographic effect of MP and YGP on the Asian climate. The results show that, the MP, despite its smaller size, exerts a great influence on the strengthened winter climate over East Asia, including the East Asian trough, the subtropical westerly jet and the winter monsoon. The YGP, however, plays an opposite role in the Indian monsoon change, compared to the main TP. It weakens the Indian summer monsoon circulation and associated precipitation. Thus, the response of Asian climate to the mountain uplift depends closely on the actual distributions of topography rather than a simplified bulk of main TP.

  12. Interdigital filter design

    CSIR Research Space (South Africa)

    Du Plessis, WP

    2009-10-01

    Full Text Available flexible, and allows design tradeoffs to be evaluated in an intuitive way. Keywords: Cavity resonator filters, microwave filters, coupled transmission lines. 1 Introduction Interdigital filters are popular at the higher microwave frequencies for a... number of reasons. Ideal interdigital filters have perfect symmetry which means that they have better phase and delay characteristics than combline filters [1]. The couplings between the resonators of interdigital filters are also lower than those...

  13. FILTSoft: A computational tool for microstrip planar filter design

    Science.gov (United States)

    Elsayed, M. H.; Abidin, Z. Z.; Dahlan, S. H.; Cholan N., A.; Ngu, Xavier T. I.; Majid, H. A.

    2017-09-01

    Filters are key component of any communication system to control spectrum and suppress interferences. Designing a filter involves long process as well as good understanding of the basic hardware technology. Hence this paper introduces an automated design tool based on Matlab-GUI, called the FILTSoft (acronym for Filter Design Software) to ease the process. FILTSoft is a user friendly filter design tool to aid, guide and expedite calculations from lumped elements level to microstrip structure. Users just have to provide the required filter specifications as well as the material description. FILTSoft will calculate and display the lumped element details, the planar filter structure, and the expected filter's response. An example of a lowpass filter design was calculated using FILTSoft and the results were validated through prototype measurement for comparison purposes.

  14. Change of International Restless Legs Syndrome Study Group Rating Scale subscales with treatment and placebo: a pilot study

    Directory of Open Access Journals (Sweden)

    Mitchell UH

    2014-02-01

    Full Text Available Ulrike H Mitchell,1 Sterling C Hilton2 1Brigham Young University, Department of Exercise Sciences, 2Department of Educational Leadership and Foundations, Provo, UT, USA Background: In 2003, the 10-question International Restless Legs Syndrome Study Group Rating Scale (IRLS was developed as a means of assessing the severity of restless legs syndrome. Two subscales were identified: symptom severity (SS 1 and symptom impact (SS 2. Only one study has investigated the subscales' responsiveness to a 12-week treatment with ropinirole. This current study was undertaken to assess the impact of a 4-week, non-pharmaceutical treatment on the two subscales and to explore whether or not both subscales were impacted by the observed placebo effect. Methods: The pooled data from questionnaires of 58 patients (41 from both treatment groups and 17 from the sham treatment control group, who participated in two clinical studies, were reviewed. Their change in score over a 4-week trial was computed. The average change in both subscales in both groups was computed and t-tests were performed. Results: In the treatment group, the average scores of both subscales changed significantly from baseline to week 4 (P<0.005 for both. Compared to the control, SS 1 changed (P<0.001, but not SS 2 (P=0.18. In the sham treatment group, the scores for SS 1 changed significantly (P=0.002, but not for SS 2 (P=0.2. Conclusion: This study corroborated findings from an earlier study in which both subscales changed with a 12-week drug treatment. It also showed that the observed placebo effect is attributed to a small but significant change in symptom severity, but not symptom impact. Keywords: restless legs syndrome, RLS severity scale, IRLS subscales, symptom impact, symptom severity

  15. DOE standard: Quality assurance inspection and testing of HEPA filters

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-02-01

    This standard establishes essential elements for the quality assurance inspection and testing of HEPA filters by US Department of Energy (DOE)-accepted Filter Test Facilities (FTF). The standard specifies HEPA filter quality assurance inspection and testing practices established in DOE-STD-3022-98, DOE HEPA Filter Test Program, and provides a basis for the preparation of written operating procedures for primary FTF functions.

  16. Reconfigurable Ring Filter with Controllable Frequency Response

    Directory of Open Access Journals (Sweden)

    Norfishah Ab Wahab

    2014-01-01

    Full Text Available Reconfigurable ring filter based on single-side-access ring topology is presented. Using capacitive tuning elements, the electrical length of the ring can be manipulated to shift the nominal center frequency to a desired position. A synthesis is developed to determine the values of the capacitive elements. To show the advantage of the synthesis, it is applied to the reconfigurable filter design using RF lumped capacitors. The concept is further explored by introducing varactor-diodes to continuously tune the center frequency of the ring filter. For demonstration, two prototypes of reconfigurable ring filters are realized using microstrip technology, simulated, and measured to validate the proposed concept. The reconfigured filter using lumped elements is successfully reconfigured from 2 GHz to 984.4 MHz and miniaturized by 71% compared to the filter directly designed at the same reconfigured frequency, while, for the filter using varactor-diodes, the frequency is chosen from 1.10 GHz to 1.38 GHz spreading over 280 MHz frequency range. Both designs are found to be compact with acceptable insertion loss and high selectivity.

  17. Stability of memories of parental rearing among psychiatric inpatients: a replication based on EMBU subscales.

    Science.gov (United States)

    Richter, J; Eisemann, M

    2001-01-01

    With regard to information about parental rearing, retrospective data are exclusively available among adults. These data are vulnerable due to various biases. This study was performed in order to replicate the findings of overall stability of three perceived parental rearing factors of the EMBU (Swedish acronym for 'own memories of childhood upbringing') based on 14 rather detailed subscales. A consecutive sample of 220 depressive inpatients were investigated on admission and at discharge by means of the EMBU, the Beck Depression Inventory and the Dysfunctional Attitude Scale. Perceived parental rearing scores showed high stability despite clinically significant changes in the severity of depression, except for 'tolerance', 'guilt engendering', 'performance orientation' and 'shaming' parenting with probable gender-specific effects which were found to covary with dysfunctional attitudes. Recall of parenting should be taken as a subjective truth when it is assessed by standardised behaviour-oriented questionnaires like the EMBU. Copyright 2002 S. Karger AG, Basel

  18. Anxiety Sensitivity Index (ASI-3) subscales predict unique variance in anxiety and depressive symptoms.

    Science.gov (United States)

    Olthuis, Janine V; Watt, Margo C; Stewart, Sherry H

    2014-03-01

    Anxiety sensitivity (AS) has been implicated in the development and maintenance of a range of mental health problems. The development of the Anxiety Sensitivity Index - 3, a psychometrically sound index of AS, has provided the opportunity to better understand how the lower-order factors of AS - physical, psychological, and social concerns - are associated with unique forms of psychopathology. The present study investigated these associations among 85 treatment-seeking adults with high AS. Participants completed measures of AS, anxiety, and depression. Multiple regression analyses controlling for other emotional disorder symptoms revealed unique associations between AS subscales and certain types of psychopathology. Only physical concerns predicted unique variance in panic, only cognitive concerns predicted unique variance in depressive symptoms, and social anxiety was predicted by only social concerns. Findings emphasize the importance of considering the multidimensional nature of AS in understanding its role in anxiety and depression and their treatment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. The technology - activities of daily living questionnaire: a version with a technology-related subscale.

    Science.gov (United States)

    Muñoz-Neira, Carlos; López, Oscar L; Riveros, Rodrigo; Núñez-Huasaf, Javier; Flores, Patricia; Slachevsky, Andrea

    2012-01-01

    Information and communication technology (ICT) has become an increasingly important part of daily life. The ability to use technology is becoming essential for autonomous functioning in society. Current functional scales for patients with cognitive impairment do not evaluate the use of technology. The objective of this study was to develop and validate a new version of the Activities of Daily Living Questionnaire (ADLQ) that incorporates an ICT subscale. A new technology-based subscale was incorporated into the Spanish version of the ADLQ (SV-ADLQ), entitled the Technology version of the ADLQ (T-ADLQ). The T-ADLQ was administered to 63 caregivers of dementia patients, 21 proxies of mild cognitive impairment patients and 44 proxies of normal elderly subjects (mean age of the sample ± SD: 73.5 ± 8.30 years). We analysed the convergent validity, internal consistency, reliability cut-off point, sensitivity and specificity of the T-ADLQ. The results of the T-ADLQ were compared to the SV-ADLQ. The T-ADLQ showed significant correlations with the Mini-Mental State Examination (MMSE), the Frontal Assessment Battery (FAB) as well as other measures of functional impairment and dementia severity (MMSE: r = -0.70; FAB: r = -0.65; Functional Assessment Questionnaire: r = 0.77; Instrumental Activities of Daily Living Scale: r = -0.75; Clinical Dementia Rating Scale: r = 0.72; p questions to the ADLQ, our experience suggested that this has to be done cautiously, since the sensitivity of these additional items could vary in different populations. The T-ADLQ needs to be validated in a different population of dementia subjects. Copyright © 2012 S. Karger AG, Basel.

  20. Vertical equilibrium with sub-scale analytical methods for geological CO2 sequestration

    KAUST Repository

    Gasda, S. E.

    2009-04-23

    Large-scale implementation of geological CO2 sequestration requires quantification of risk and leakage potential. One potentially important leakage pathway for the injected CO2 involves existing oil and gas wells. Wells are particularly important in North America, where more than a century of drilling has created millions of oil and gas wells. Models of CO 2 injection and leakage will involve large uncertainties in parameters associated with wells, and therefore a probabilistic framework is required. These models must be able to capture both the large-scale CO 2 plume associated with the injection and the small-scale leakage problem associated with localized flow along wells. Within a typical simulation domain, many hundreds of wells may exist. One effective modeling strategy combines both numerical and analytical models with a specific set of simplifying assumptions to produce an efficient numerical-analytical hybrid model. The model solves a set of governing equations derived by vertical averaging with assumptions of a macroscopic sharp interface and vertical equilibrium. These equations are solved numerically on a relatively coarse grid, with an analytical model embedded to solve for wellbore flow occurring at the sub-gridblock scale. This vertical equilibrium with sub-scale analytical method (VESA) combines the flexibility of a numerical method, allowing for heterogeneous and geologically complex systems, with the efficiency and accuracy of an analytical method, thereby eliminating expensive grid refinement for sub-scale features. Through a series of benchmark problems, we show that VESA compares well with traditional numerical simulations and to a semi-analytical model which applies to appropriately simple systems. We believe that the VESA model provides the necessary accuracy and efficiency for applications of risk analysis in many CO2 sequestration problems. © 2009 Springer Science+Business Media B.V.

  1. Active Optical Lattice Filters

    Directory of Open Access Journals (Sweden)

    Gary Evans

    2005-06-01

    Full Text Available Optical lattice filter structures including gains are introduced and analyzed. The photonic realization of the active, adaptive lattice filter is described. The algorithms which map between gains space and filter coefficients space are presented and studied. The sensitivities of filter parameters with respect to gains are derived and calculated. An example which is relevant to adaptive signal processing is also provided.

  2. Filter replacement lifetime prediction

    Science.gov (United States)

    Hamann, Hendrik F.; Klein, Levente I.; Manzer, Dennis G.; Marianno, Fernando J.

    2017-10-25

    Methods and systems for predicting a filter lifetime include building a filter effectiveness history based on contaminant sensor information associated with a filter; determining a rate of filter consumption with a processor based on the filter effectiveness history; and determining a remaining filter lifetime based on the determined rate of filter consumption. Methods and systems for increasing filter economy include measuring contaminants in an internal and an external environment; determining a cost of a corrosion rate increase if unfiltered external air intake is increased for cooling; determining a cost of increased air pressure to filter external air; and if the cost of filtering external air exceeds the cost of the corrosion rate increase, increasing an intake of unfiltered external air.

  3. Preconditioning Filter Bank Decomposition Using Structured Normalized Tight Frames

    Directory of Open Access Journals (Sweden)

    Martin Ehler

    2015-01-01

    Full Text Available We turn a given filter bank into a filtering scheme that provides perfect reconstruction, synthesis is the adjoint of the analysis part (so-called unitary filter banks, all filters have equal norm, and the essential features of the original filter bank are preserved. Unitary filter banks providing perfect reconstruction are induced by tight generalized frames, which enable signal decomposition using a set of linear operators. If, in addition, frame elements have equal norm, then the signal energy is spread through the various filter bank channels in some uniform fashion, which is often more suitable for further signal processing. We start with a given generalized frame whose elements allow for fast matrix vector multiplication, as, for instance, convolution operators, and compute a normalized tight frame, for which signal analysis and synthesis still preserve those fast algorithmic schemes.

  4. Fatigue life prediction of liquid rocket engine combustor with subscale test verification

    Science.gov (United States)

    Sung, In-Kyung

    Reusable rocket systems such as the Space Shuttle introduced a new era in propulsion system design for economic feasibility. Practical reusable systems require an order of magnitude increase in life. To achieve this improved methods are needed to assess failure mechanisms and to predict life cycles of rocket combustor. A general goal of the research was to demonstrate the use of subscale rocket combustor prototype in a cost-effective test program. Life limiting factors and metal behaviors under repeated loads were surveyed and reviewed. The life prediction theories are presented, with an emphasis on studies that used subscale test hardware for model validation. From this review, low cycle fatigue (LCF) and creep-fatigue interaction (ratcheting) were identified as the main life limiting factors of the combustor. Several life prediction methods such as conventional and advanced viscoplastic models were used to predict life cycle due to low cycle thermal stress, transient effects, and creep rupture damage. Creep-fatigue interaction and cyclic hardening were also investigated. A prediction method based on 2D beam theory was modified using 3D plate deformation theory to provide an extended prediction method. For experimental validation two small scale annular plug nozzle thrusters were designed, built and tested. The test article was composed of a water-cooled liner, plug annular nozzle and 200 psia precombustor that used decomposed hydrogen peroxide as the oxidizer and JP-8 as the fuel. The first combustor was tested cyclically at the Advanced Propellants and Combustion Laboratory at Purdue University. Testing was stopped after 140 cycles due to an unpredicted failure mechanism due to an increasing hot spot in the location where failure was predicted. A second combustor was designed to avoid the previous failure, however, it was over pressurized and deformed beyond repair during cold-flow test. The test results are discussed and compared to the analytical and numerical

  5. Separating the Domains of Oppositional Behavior: Comparing Latent Models of the Conners’ Oppositional Subscale

    Science.gov (United States)

    Kuny, Ana V.; Althoff, Robert R.; Copeland, William; Bartels, Meike; Beijsterveldt, Van; Baer, Julie; Hudziak, James J.

    2012-01-01

    OBJECTIVE Although Oppositional Defiant Disorder (ODD) is usually considered the mildest of the disruptive behavior disorders, it is a key factor in predicting young adult anxiety and depression and is distinguishable from normal childhood behavior. In an effort to understand possible subsets of oppositional defiant behavior (ODB) which may differentially predict outcome, we used Latent Class Analysis (LCA) of mother’s report on the Conners’ Parent Rating Scales Revised Short Forms (CPRS-R:S). METHOD Data were obtained from mother’s report for Dutch twins (7 year-old [n = 7,597], 10 year-old [n = 6,548], and 12 year-old [n = 5,717]) from the Netherlands Twin Registry. Samples partially overlapped at ages 7 and 10 (19% overlapping) and at ages 10 and 12 (30% overlapping), but not at ages 7 and 12. Oppositional defiant behavior was measured using the 6-item Oppositional subscale of the CPRS-R:S. Multilevel LCA with robust standard error estimates was performed using Latent Gold to control for twin-twin dependence in the data. Class assignment across ages was determined and an estimate of heritability for each class was calculated. Comparisons to maternal report Child Behavior Checklist (CBCL) scores were examined using linear mixed models at each age, corrected for multiple comparisons. RESULTS The LCA identified an optimal solution of 4-classes across age groups: Class 1 was associated with no or low symptom endorsement (69–75% of the children), class 2 was characterized by defiance (11–12%), class 3 was characterized by irritability (9–11%), and class 4 was associated with elevated scores on all symptoms (5–8%). Odds ratios for twins being in the same class at each successive age point were higher within classes across ages than between classes. Heritability within the two “intermediate” classes was nearly as high as for the class with all symptoms, except for boys at age 12. Children in the Irritable Class were more likely to have mood symptoms

  6. Sensory Pollution from Bag Filters, Carbon Filters and Combinations

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Clausen, Geo; Weschler, Charles J.

    2008-01-01

    by an upstream pre-filter (changed monthly), an EU7 filter protected by an upstream activated carbon (AC) filter, and EU7 filters with an AC filter either downstream or both upstream and downstream. In addition, two types of stand-alone combination filters were evaluated: a bag-type fiberglass filter...

  7. The Pattern Element Scale: A Brief Tool of Traditional Medical Subtyping for Dementia

    Directory of Open Access Journals (Sweden)

    Jing Shi

    2013-01-01

    Full Text Available Background. Syndromes are defined by traditional Chinese medicine as consisting of different pattern elements. Few scales have been designed for differentiating pattern elements of dementia and have shown major flaws. Thus, a new pattern element scale (PES was developed. This study aimed to evaluate the utility of the PES in dementia patients. Methods. A total of 171 dementia patients were enrolled, and their pattern elements were ascertained, first by clinicians using the PES, then compared with results by two experts to be used as a standard criterion independently. Reliability of the subscales of the PES was assessed by receiver operator characteristic curves. Correlations between the subscales of the PES and cognition were calculated by canonical correlation analysis. Results. The PES consisted of 11 pattern element subscales. The area under the curves of all subscales was 0.7 or above. Phlegm muddiness, blood stasis, and yang hyperactivity subscales showed optimal sensitivity and specificity in discriminating pattern elements. Other subscales showed relatively lower sensitivity but higher specificity. Memory and language were significantly correlated to qi deficiency and the blood stasis pattern element. Conclusion. The PES can accurately and easily discriminate pattern elements and is a helpful tool for traditional medical subtyping of dementia.

  8. Subscale and Full-Scale Testing of Buckling-Critical Launch Vehicle Shell Structures

    Science.gov (United States)

    Hilburger, Mark W.; Haynie, Waddy T.; Lovejoy, Andrew E.; Roberts, Michael G.; Norris, Jeffery P.; Waters, W. Allen; Herring, Helen M.

    2012-01-01

    New analysis-based shell buckling design factors (aka knockdown factors), along with associated design and analysis technologies, are being developed by NASA for the design of launch vehicle structures. Preliminary design studies indicate that implementation of these new knockdown factors can enable significant reductions in mass and mass-growth in these vehicles and can help mitigate some of NASA s launch vehicle development and performance risks by reducing the reliance on testing, providing high-fidelity estimates of structural performance, reliability, robustness, and enable increased payload capability. However, in order to validate any new analysis-based design data or methods, a series of carefully designed and executed structural tests are required at both the subscale and full-scale level. This paper describes recent buckling test efforts at NASA on two different orthogrid-stiffened metallic cylindrical shell test articles. One of the test articles was an 8-ft-diameter orthogrid-stiffened cylinder and was subjected to an axial compression load. The second test article was a 27.5-ft-diameter Space Shuttle External Tank-derived cylinder and was subjected to combined internal pressure and axial compression.

  9. A scaling method for combustion stability rating of coaxial gas liquid injectors in a subscale chamber

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Chae Hoon; Kim, Young Jun [Sejong Univ., Seoul (Korea, Republic of); Kim, Young Mog [Korea Aerospace Research Institute, Daejeon (Korea, Republic of); Pikalov, Valery P. [Research Institute of Chemical Machine Building, Sergiev Posad (Russian Federation)

    2012-11-15

    A scaling method to examine combustion stability characteristics of a coaxial injector is devised based on the acoustics and combustion dynamics in a chamber. The method is required for a subscale test of stability rating with a model chamber, which is cost effective compared with an actual full scale test. First, scaling and similarity rules are considered for stability rating and thereby, three conditions of acoustic, hydrodynamic, and flame condition similarities are proposed. That is, for acoustic similarity, the natural or resonant frequencies in the actual chamber should be maintained in the model chamber. And, two parameters of density ratio and velocity ratio are derived for the requirement of hydrodynamic and flame condition similarities between the actual and the model conditions. Next, one example of an actual combustion chamber with high performance is selected and the proposed scaling method is applied to the chamber for understanding of the method. The design operating condition for a model test is presented by mass flow rates of propellants. Stability boundaries can be identified on the coordinate plane of chamber pressure and mixture ratio of fuel and oxidizer by applying the scaling method.

  10. Static Aeroelastic Scaling and Analysis of a Sub-Scale Flexible Wing Wind Tunnel Model

    Science.gov (United States)

    Ting, Eric; Lebofsky, Sonia; Nguyen, Nhan; Trinh, Khanh

    2014-01-01

    This paper presents an approach to the development of a scaled wind tunnel model for static aeroelastic similarity with a full-scale wing model. The full-scale aircraft model is based on the NASA Generic Transport Model (GTM) with flexible wing structures referred to as the Elastically Shaped Aircraft Concept (ESAC). The baseline stiffness of the ESAC wing represents a conventionally stiff wing model. Static aeroelastic scaling is conducted on the stiff wing configuration to develop the wind tunnel model, but additional tailoring is also conducted such that the wind tunnel model achieves a 10% wing tip deflection at the wind tunnel test condition. An aeroelastic scaling procedure and analysis is conducted, and a sub-scale flexible wind tunnel model based on the full-scale's undeformed jig-shape is developed. Optimization of the flexible wind tunnel model's undeflected twist along the span, or pre-twist or wash-out, is then conducted for the design test condition. The resulting wind tunnel model is an aeroelastic model designed for the wind tunnel test condition.

  11. Wideband Lithium Niobate FBAR Filters

    Directory of Open Access Journals (Sweden)

    Thomas Baron

    2013-01-01

    Full Text Available Filters based on film bulk acoustic resonators (FBARs are widely used for mobile phone applications, but they can also address wideband aerospace requirements. These devices need high electromechanical coupling coefficients to achieve large band pass filters. The piezoelectric material LiNbO3 complies with such specifications and is compatible with standard fabrication processes. In this work, simple metal—LiNbO3—metal structures have been developed to fabricate single FBAR elements directly connected to each other on a single chip. A fabrication process based on LiNbO3/silicon Au-Au bonding and LiNbO3 lapping/polishing has been developed and is proposed in this paper. Electrical measurements of these FBAR filters are proposed and commented exhibiting filters with 8% of fractional bandwidth and 3.3 dB of insertion losses. Electrical measurements show possibilities to obtain 14% of fractional bandwidth. These devices have been packaged, allowing for power handling, thermal, and ferroelectric tests, corresponding to spatial conditions.

  12. In Defense of Filtering.

    Science.gov (United States)

    Burt, David

    1997-01-01

    Presents responses to 10 common arguments against the use of Internet filters in libraries. Highlights include keyword blocking; selection of materials; liability of libraries using filters; users' judgments; Constitutional issues, including First Amendment rights; and censorship. (LRW)

  13. HEPA filter monitoring program

    Science.gov (United States)

    Kirchner, K. N.; Johnson, C. M.; Aiken, W. F.; Lucerna, J. J.; Barnett, R. L.; Jensen, R. T.

    1986-07-01

    The testing and replacement of HEPA filters, widely used in the nuclear industry to purify process air, are costly and labor-intensive. Current methods of testing filter performance, such as differential pressure measurement and scanning air monitoring, allow determination of overall filter performance but preclude detection of incipient filter failure such as small holes in the filters. Using current technology, a continual in-situ monitoring system was designed which provides three major improvements over current methods of filter testing and replacement. The improvements include: cost savings by reducing the number of intact filters which are currently being replaced unnecessarily; more accurate and quantitative measurement of filter performance; and reduced personnel exposure to a radioactive environment by automatically performing most testing operations.

  14. Novel Backup Filter Device for Candle Filters

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, B.; Goldsmith, R.; Dunham, G.; Henderson, A.

    2002-09-18

    The currently preferred means of particulate removal from process or combustion gas generated by advanced coal-based power production processes is filtration with candle filters. However, candle filters have not shown the requisite reliability to be commercially viable for hot gas clean up for either integrated gasifier combined cycle (IGCC) or pressurized fluid bed combustion (PFBC) processes. Even a single candle failure can lead to unacceptable ash breakthrough, which can result in (a) damage to highly sensitive and expensive downstream equipment, (b) unacceptably low system on-stream factor, and (c) unplanned outages. The U.S. Department of Energy (DOE) has recognized the need to have fail-safe devices installed within or downstream from candle filters. In addition to CeraMem, DOE has contracted with Siemens-Westinghouse, the Energy & Environmental Research Center (EERC) at the University of North Dakota, and the Southern Research Institute (SRI) to develop novel fail-safe devices. Siemens-Westinghouse is evaluating honeycomb-based filter devices on the clean-side of the candle filter that can operate up to 870 C. The EERC is developing a highly porous ceramic disk with a sticky yet temperature-stable coating that will trap dust in the event of filter failure. SRI is developing the Full-Flow Mechanical Safeguard Device that provides a positive seal for the candle filter. Operation of the SRI device is triggered by the higher-than-normal gas flow from a broken candle. The CeraMem approach is similar to that of Siemens-Westinghouse and involves the development of honeycomb-based filters that operate on the clean-side of a candle filter. The overall objective of this project is to fabricate and test silicon carbide-based honeycomb failsafe filters for protection of downstream equipment in advanced coal conversion processes. The fail-safe filter, installed directly downstream of a candle filter, should have the capability for stopping essentially all particulate

  15. MST Filterability Tests

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Burket, P. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Duignan, M. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-03-12

    The Savannah River Site (SRS) is currently treating radioactive liquid waste with the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Extraction Unit (MCU). The low filter flux through the ARP has limited the rate at which radioactive liquid waste can be treated. Recent filter flux has averaged approximately 5 gallons per minute (gpm). Salt Batch 6 has had a lower processing rate and required frequent filter cleaning. Savannah River Remediation (SRR) has a desire to understand the causes of the low filter flux and to increase ARP/MCU throughput. In addition, at the time the testing started, SRR was assessing the impact of replacing the 0.1 micron filter with a 0.5 micron filter. This report describes testing of MST filterability to investigate the impact of filter pore size and MST particle size on filter flux and testing of filter enhancers to attempt to increase filter flux. The authors constructed a laboratory-scale crossflow filter apparatus with two crossflow filters operating in parallel. One filter was a 0.1 micron Mott sintered SS filter and the other was a 0.5 micron Mott sintered SS filter. The authors also constructed a dead-end filtration apparatus to conduct screening tests with potential filter aids and body feeds, referred to as filter enhancers. The original baseline for ARP was 5.6 M sodium salt solution with a free hydroxide concentration of approximately 1.7 M.3 ARP has been operating with a sodium concentration of approximately 6.4 M and a free hydroxide concentration of approximately 2.5 M. SRNL conducted tests varying the concentration of sodium and free hydroxide to determine whether those changes had a significant effect on filter flux. The feed slurries for the MST filterability tests were composed of simple salts (NaOH, NaNO2, and NaNO3) and MST (0.2 – 4.8 g/L). The feed slurry for the filter enhancer tests contained simulated salt batch 6 supernate, MST, and filter enhancers.

  16. CCII based fractional filters of different orders

    Directory of Open Access Journals (Sweden)

    Ahmed Soltan

    2014-03-01

    Full Text Available This paper aims to generalize the design of continuous-time filters to the fractional domain with different orders and validates the theoretical results with two different CCII based filters. In particular, the proposed study introduces the generalized formulas for the previous fractional-order analysis of equal orders. The fractional-order filters enhance the design flexibility and prove that the integer-order performance is a very narrow subset from the fractional-order behavior due to the extra degrees of freedom. The general fundamentals of these filters are presented by calculating the maximum and minimum frequencies, the half power frequency and the right phase frequency which are considered a critical issue for the filter design. Different numerical solutions for the generalized fractional order low pass filters with two different fractional order elements are introduced and verified by the circuit simulations of two fractional-order filters: Kerwin–Huelsman–Newcomb (KHN and Tow-Tomas CCII-based filters, showing great matching.

  17. Oriented Fiber Filter Media

    OpenAIRE

    R. Bharadwaj; A. Patel, S. Chokdeepanich, Ph.D.; G.G. Chase, Ph.D.

    2008-01-01

    Coalescing filters are widely used throughout industry and improved performance will reduce droplet emissions and operating costs. Experimental observations show orientation of micro fibers in filter media effect the permeability and the separation efficiency of the filter media. In this work two methods are used to align the fibers to alter the filter structure. The results show that axially aligned fiber media improve quality factor on the order of 20% and cutting media on an angle from a t...

  18. Bias aware Kalman filters

    DEFF Research Database (Denmark)

    Drecourt, J.-P.; Madsen, H.; Rosbjerg, Dan

    2006-01-01

    This paper reviews two different approaches that have been proposed to tackle the problems of model bias with the Kalman filter: the use of a colored noise model and the implementation of a separate bias filter. Both filters are implemented with and without feedback of the bias into the model sta...

  19. HEPA filter encapsulation

    Science.gov (United States)

    Gates-Anderson, Dianne D.; Kidd, Scott D.; Bowers, John S.; Attebery, Ronald W.

    2003-01-01

    A low viscosity resin is delivered into a spent HEPA filter or other waste. The resin is introduced into the filter or other waste using a vacuum to assist in the mass transfer of the resin through the filter media or other waste.

  20. Measuring Neuroticism in Nepali: Reliability and Validity of the Neuroticism Subscale of the Eysenck Personality Questionnaire.

    Science.gov (United States)

    Manandhar, K; Risal, A; Linde, M; Koju, R; Steiner, T J; Holen, A

    2015-01-01

    The Neuroticism subscale of the Eysenck Personality Questionnaire Revised Short Form (12 items) (EPQRS-N) has proven to be a reliable and valid measure in multiple languages. To develop a single-factor Nepali-language version of the EPQRS-N for use in the adult population of Nepal. The original English version of EPQRS-N was translated into Nepali using a forward-backward translation protocol. The first set of translated items was modified after testing by factor analysis with principal component extraction in an outpatient sample. Items with low factor correlations or poor semantic consistencies were reworded to fit the gist of the original items in a Nepali cultural context; the revised version was then tested in a representative random sample from the general population. Again, the same statistical procedures were applied. The first trial gave three factors. Based on the factor distribution of the items or their semantic quality, five were reworded. In the second trial, a two-factor solution emerged; the second factor had only one item with high correlation, which also had modest correlation with the first factor. Accordingly, a forced one-factor solution was chosen. This gave an internal consistency (Cronbach's alpha) of 0.80, with item-to-factor correlations from 0.40 to 0.73, and item-to-sum correlations from 0.31 to 0.61. The final Nepali version of EPQRS-N achieved satisfactory internal consistency. The item distribution coincided with the original English version, providing acceptable construct validity. It is psychometrically adequate for use in capturing the personality trait of neuroticism, and has broad applicability to the adult population of Nepal because of the diversity of the participant samples in which it was developed.

  1. Confirmatory Factor Analysis of the PKBS-2 Subscales for Assessing Social Skills and Behavioral Problems in Preschool Education

    Science.gov (United States)

    Fernandez, Maria; Benitez, Juan L.; Pichardo, M. Carmen; Fernandez, Eduardo; Justicia, Fernando; Garcia, Trinidad; Garcia-Berben, Ana; Justicia, Ana; Alba, Guadalupe

    2010-01-01

    Introduction: Different research studies point out the importance of social competence as a protective factor against antisocial behavior. They likewise alert us of the importance of having valid, reliable instruments that measure these constructs in early childhood. Method: The objective of this research is to validate the subscales of the…

  2. The development of the items-easy (Ie) and items-difficult (Id) subscales for the MMPI-A.

    Science.gov (United States)

    Krakauer, S Y; Archer, R P; Gordon, R A

    1993-06-01

    This research involves the development, validation, and cross-validation of the Items-Easy (Ie) and Items-Difficult (Id) subscales for the Minnesota Multiphasic Personality Inventory-Adolescent (MMPI-A; Butcher et al., 1992). These subscales were designed to assess the degree to which reading comprehension deficits may be responsible for significant elevations of validity Scale F and the standard clinical scales on adolescents' MMPI-A profiles. A difference score, bared on the two 13-item subscales, was created in order to compare subjects' responses to subsets of the more comprehensible (Ie) and less comprehensible (Id) items within the test. Hit rate, sensitivity, specificity, positive predictive power, and negative predictive power were calculated on the basis of simple (Id - Ie) and weighted (3Id - 1Ie) difference scores for the validation (N = 495) and cross-validation (N = 264) samples, and for specific high-F profile subsamples. Although some of the indices reflected classification accuracy as high as 95%, none of the indices yielded consistently high results across the various samples and subsamples. It has been concluded that the Ie and Id subscales should be used only for research purposes at this time.

  3. Validity of the Sleep Subscale of the Diagnostic Assessment for the Severely Handicapped-II (DASH-II)

    Science.gov (United States)

    Matson, Johnny L.; Malone, Carrie J.

    2006-01-01

    Currently there are no available sleep disorder measures for individuals with severe and profound intellectual disability. We, therefore, attempted to establish the external validity of the "Diagnostic Assessment for the Severely Handicapped-II" (DASH-II) sleep subscale by comparing daily observational sleep data with the responses of…

  4. Comparison of behavioral activation subscales of Gray’s original reinforcement sensitivity theory in opioid and methamphetamine dependent patients

    Directory of Open Access Journals (Sweden)

    Amir Ghaderi

    2017-10-01

    Results: The methamphetamine-dependents group had a higher BAS-DR subscale score than the opioid dependent group (P0.05. The BAS-RR scores of the methamphetamine-dependents group were higher than the other two groups (P

  5. Design of Microwave Multibandpass Filters with Quasilumped Resonators

    Directory of Open Access Journals (Sweden)

    Dejan Miljanović

    2015-01-01

    Full Text Available Design of RF and microwave filters has always been the challenging engineering field. Modern filter design techniques involve the use of the three-dimensional electromagnetic (3D EM solvers for predicting filter behavior, yielding the most accurate filter characteristics. However, the 3D EM simulations are time consuming. In this paper, we propose electric-circuit models, instead of 3D EM models, suitable for design of RF and microwave filters with quasilumped coupled resonators. Using the diakoptic approach, the 3D filter structure is decomposed into domains that are modeled by electric networks. The coupling between these domains is modeled by capacitors and coupled inductors. Furthermore, we relate the circuit-element values to the physical dimensions of the 3D filter structure. We propose the filter design procedure that is based on the circuit models and fast circuit-level simulations, yielding the element values from which the physical dimensions can be obtained. The obtained dimensions should be slightly refined for achieving the desired filter characteristics. The mathematical problems encountered in the procedure are solved by numerical and symbolic computations. The procedure is exemplified by designing a triple-bandpass filter and validated by measurements on the fabricated filter. The simulation and experimental results are in good agreement.

  6. Ceramic fiber filter technology

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, B.L.; Janney, M.A.

    1996-06-01

    Fibrous filters have been used for centuries to protect individuals from dust, disease, smoke, and other gases or particulates. In the 1970s and 1980s ceramic filters were developed for filtration of hot exhaust gases from diesel engines. Tubular, or candle, filters have been made to remove particles from gases in pressurized fluidized-bed combustion and gasification-combined-cycle power plants. Very efficient filtration is necessary in power plants to protect the turbine blades. The limited lifespan of ceramic candle filters has been a major obstacle in their development. The present work is focused on forming fibrous ceramic filters using a papermaking technique. These filters are highly porous and therefore very lightweight. The papermaking process consists of filtering a slurry of ceramic fibers through a steel screen to form paper. Papermaking and the selection of materials will be discussed, as well as preliminary results describing the geometry of papers and relative strengths.

  7. Electronically Tunable Resistorless Mixed Mode Biquad Filters

    Directory of Open Access Journals (Sweden)

    A. Yesil

    2013-12-01

    Full Text Available This paper presents a new realization of elec¬tronically tunable mixed mode (including transadmittance- and voltage-modes biquad filter with single input, three outputs or three inputs, single output using voltage differ-encing transconductance amplifier (VDTA, a recently introduced active element. It can simultaneously realize standard filtering signals: low-pass, band-pass and high-pass or by selecting input terminals, it can realize all five different filtering signals: low-pass, band-pass, high-pass, band-stop and all-pass. The proposed filter circuit offers the following attractive feature: no requirement of invert-ing type input signal which is require no addition circuit, critical component matching conditions are not required in the design, the circuit parameters ω0 and Q can be set orthogonally or independently through adjusting the bias currents of the VDTAs, the proposed circuit employs two active and minimum numbers of passive components. Fur-thermore, this filter was investigated from the point of view of limited frequency range, stability conditions, effects of parasitic elements and effects of non-ideal and sensitivity. Thus, taking these effects and conditions into considera¬tion, working conditions and boundaries of this filter are determined. We also performed Monte Carlo, THD and noise analyses. Simulation results are given to confirm theoretical analyses.

  8. [Turkish expressive and receptive language test: I. Standardization, reliability and validity study of the receptive vocabulary sub-scale].

    Science.gov (United States)

    Kazak Berument, Sibel; Güven, Ayşe Gül

    2013-01-01

    A reliable, valid and original test to assess the receptive vocabulary skills of children in Turkey was not available. Thus, the purpose of the current study was to develop a receptive vocabulary test for Turkish children based on the Turkish language. For the Receptive Vocabulary Sub-Scale (TIFALDI-RT) 242 concrete and abstract words were chosen from word frequency lists and a comprehensive Turkish Dictionary. Pilot data were collected from 648 children aged 2 to 13 from Ankara, and norm data were collected from a nationally representative sample of 3755 children. Item analysis (item difficulty, discrimination and distractor) was carried out on the pilot data and based on the results, the total item number was reduced to 157. Further, three parameter item analyses (IRT) were carried out on the norm data by using BILOG-MG (SSI, 2002), and the results indicated that the TIFALDI Receptive Vocabulary Sub-Scale could be reduced to 104 items to assess 2 to 12 year-old children's receptive vocabulary. Test-retest and internal consistency reliabilities were calculated for the whole sample and age groups separately, and all the coefficients were high. For the validity, the relationship between the WISC-R and Ankara Developmental Screening Inventory (AGTE) and Receptive Vocabulary Sub-Scale were investigated. Once again, the TIFALDI Receptive Vocabulary Sub-Scale scores were found to be significantly related to WISC-R and AGTE scores. The TIFALDI Receptive Vocabulary Sub-Scale was developed on the basis of the Turkish Language and norm data were collected from a nationally representative sample. The TIFALDI-RT also had a high reliability and validity. Thus, the TIFALDI-RT can be used to assess 2 to 12 year-old children's receptive vocabulary skills.

  9. The genetic and environmental structure of the character sub-scales of the temperament and character inventory in adolescence.

    Science.gov (United States)

    Lester, Nigel; Garcia, Danilo; Lundström, Sebastian; Brändström, Sven; Råstam, Maria; Kerekes, Nóra; Nilsson, Thomas; Cloninger, C Robert; Anckarsäter, Henrik

    2016-01-01

    The character higher order scales (self-directedness, cooperativeness, and self-transcendence) in the temperament and character inventory are important general measures of health and well-being [Mens Sana Monograph 11:16-24 (2013)]. Recent research has found suggestive evidence of common environmental influence on the development of these character traits during adolescence. The present article expands earlier research by focusing on the internal consistency and the etiology of traits measured by the lower order sub-scales of the character traits in adolescence. The twin modeling analysis of 423 monozygotic pairs and 408 same sex dizygotic pairs estimated additive genetics (A), common environmental (C), and non-shared environmental (E) influences on twin resemblance. All twins were part of the on-going longitudinal Child and Adolescent Twin Study in Sweden (CATSS). The twin modeling analysis suggested a common environmental contribution for two out of five self-directedness sub-scales (0.14 and 0.23), for three out of five cooperativeness sub-scales (0.07-0.17), and for all three self-transcendence sub-scales (0.10-0.12). The genetic structure at the level of the character lower order sub-scales in adolescents shows that the proportion of the shared environmental component varies in the trait of self-directedness and in the trait of cooperativeness, while it is relatively stable across the components of self-transcendence. The presence of this unique shared environmental effect in adolescence has implications for understanding the relative importance of interventions and treatment strategies aimed at promoting overall maturation of character, mental health, and well-being during this period of the life span.

  10. A tool for filtering information in complex systems

    Science.gov (United States)

    Tumminello, M.; Aste, T.; Di Matteo, T.; Mantegna, R. N.

    2005-07-01

    We introduce a technique to filter out complex data sets by extracting a subgraph of representative links. Such a filtering can be tuned up to any desired level by controlling the genus of the resulting graph. We show that this technique is especially suitable for correlation-based graphs, giving filtered graphs that preserve the hierarchical organization of the minimum spanning tree but containing a larger amount of information in their internal structure. In particular in the case of planar filtered graphs (genus equal to 0), triangular loops and four-element cliques are formed. The application of this filtering procedure to 100 stocks in the U.S. equity markets shows that such loops and cliques have important and significant relationships with the market structure and properties. This paper was submitted directly (Track II) to the PNAS office.Abbreviations: MST, minimum spanning tree; PMFG, Planar Maximally Filtered Graph; r-clique, clique of r elements.

  11. System Verilog modelling of FIR filters

    Science.gov (United States)

    Pawlus, Łukasz; Wegrzyn, Marek

    2006-02-01

    In the paper modelling of FIR filters by means of Verilog and SystemVerilog is presented. Hardware/software co-design approach for such systems is applied in the presented design. As a final technology for a FIR filters system implementation, a FPSLIC device is considered. Filters system demonstrates example methods of communication between FPGA and AVR microcontroller in a FPSLIC structure, i.e. the communication through SRAM memory, addressing lines, data bus, interrupts. It also demonstrates how to serve peripheral elements in FPSLIC device by means of DPI interface. FIR filters model contains also interface which implements a FPSLIC cache logic and gives opportunity to a dynamical reconfiguration of FPGA in a FPSLIC structure.

  12. Plasma Mass Filters For Nuclear Waste Reprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Fetterman, Abraham J. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Fisch, Nathaniel J. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

    2011-05-01

    Practical disposal of nuclear waste requires high-throughput separation techniques. The most dangerous part of nuclear waste is the fission product, which contains the most active and mobile radioisotopes and produces most of the heat. We suggest that the fission products could be separated as a group from nuclear waste using plasma mass filters. Plasmabased processes are well suited to separating nuclear waste, because mass rather than chemical properties are used for separation. A single plasma stage can replace several stages of chemical separation, producing separate streams of bulk elements, fission products, and actinoids. The plasma mass filters may have lower cost and produce less auxiliary waste than chemical processing plants. Three rotating plasma configurations are considered that act as mass filters: the plasma centrifuge, the Ohkawa filter, and the asymmetric centrifugal trap.

  13. Plasma Mass Filters For Nuclear Waste Reprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Abraham J. Fetterman and Nathaniel J. Fisch

    2011-05-26

    Practical disposal of nuclear waste requires high-throughput separation techniques. The most dangerous part of nuclear waste is the fission product, which contains the most active and mobile radioisotopes and produces most of the heat. We suggest that the fission products could be separated as a group from nuclear waste using plasma mass filters. Plasmabased processes are well suited to separating nuclear waste, because mass rather than chemical properties are used for separation. A single plasma stage can replace several stages of chemical separation, producing separate streams of bulk elements, fission products, and actinoids. The plasma mass filters may have lower cost and produce less auxiliary waste than chemical processing plants. Three rotating plasma configurations are considered that act as mass filters: the plasma centrifuge, the Ohkawa filter, and the asymmetric centrifugal trap.

  14. Distortion mechanisms in varactor diode-tuned microwave filters

    OpenAIRE

    Carey-Smith, BE; Warr, PA

    2006-01-01

    This paper examines the broadband distortion behavior in flexible filters employing varactor-diode tuning elements. Series- and parallel-resonant varactor-loaded transmission-lines, both commonly used in bandpass and bandstop microwave filters, are analyzed. Nonlinear Volterra-series analysis is employed to determine the second- and third-order distortion ratios dependent on the frequencies of the incident signals. It is shown that in a bandpass filter (employing parallel tuned resonators), m...

  15. The role of optical filtering in microwave phase shifting.

    Science.gov (United States)

    O Dúill, Seán; Shumakher, Evgeny; Eisenstein, Gadi

    2010-07-01

    We highlight the importance of the delay arising from optical filters in slow-light-based microwave phase shifting systems. We calculate the filter delay numerically from the measured amplitude response by using the well-known Kramers-Kronig relations. The complex filter transmission response is then incorporated within a numerical model with which we explain phase shifting results obtained from experiments employing semiconductor optical amplifiers as slow light elements.

  16. The diffuse ensemble filter

    Directory of Open Access Journals (Sweden)

    X. Yang

    2009-07-01

    Full Text Available A new class of ensemble filters, called the Diffuse Ensemble Filter (DEnF, is proposed in this paper. The DEnF assumes that the forecast errors orthogonal to the first guess ensemble are uncorrelated with the latter ensemble and have infinite variance. The assumption of infinite variance corresponds to the limit of "complete lack of knowledge" and differs dramatically from the implicit assumption made in most other ensemble filters, which is that the forecast errors orthogonal to the first guess ensemble have vanishing errors. The DEnF is independent of the detailed covariances assumed in the space orthogonal to the ensemble space, and reduces to conventional ensemble square root filters when the number of ensembles exceeds the model dimension. The DEnF is well defined only in data rich regimes and involves the inversion of relatively large matrices, although this barrier might be circumvented by variational methods. Two algorithms for solving the DEnF, namely the Diffuse Ensemble Kalman Filter (DEnKF and the Diffuse Ensemble Transform Kalman Filter (DETKF, are proposed and found to give comparable results. These filters generally converge to the traditional EnKF and ETKF, respectively, when the ensemble size exceeds the model dimension. Numerical experiments demonstrate that the DEnF eliminates filter collapse, which occurs in ensemble Kalman filters for small ensemble sizes. Also, the use of the DEnF to initialize a conventional square root filter dramatically accelerates the spin-up time for convergence. However, in a perfect model scenario, the DEnF produces larger errors than ensemble square root filters that have covariance localization and inflation. For imperfect forecast models, the DEnF produces smaller errors than the ensemble square root filter with inflation. These experiments suggest that the DEnF has some advantages relative to the ensemble square root filters in the regime of small ensemble size, imperfect model, and copious

  17. Generic Kalman Filter Software

    Science.gov (United States)

    Lisano, Michael E., II; Crues, Edwin Z.

    2005-01-01

    The Generic Kalman Filter (GKF) software provides a standard basis for the development of application-specific Kalman-filter programs. Historically, Kalman filters have been implemented by customized programs that must be written, coded, and debugged anew for each unique application, then tested and tuned with simulated or actual measurement data. Total development times for typical Kalman-filter application programs have ranged from months to weeks. The GKF software can simplify the development process and reduce the development time by eliminating the need to re-create the fundamental implementation of the Kalman filter for each new application. The GKF software is written in the ANSI C programming language. It contains a generic Kalman-filter-development directory that, in turn, contains a code for a generic Kalman filter function; more specifically, it contains a generically designed and generically coded implementation of linear, linearized, and extended Kalman filtering algorithms, including algorithms for state- and covariance-update and -propagation functions. The mathematical theory that underlies the algorithms is well known and has been reported extensively in the open technical literature. Also contained in the directory are a header file that defines generic Kalman-filter data structures and prototype functions and template versions of application-specific subfunction and calling navigation/estimation routine code and headers. Once the user has provided a calling routine and the required application-specific subfunctions, the application-specific Kalman-filter software can be compiled and executed immediately. During execution, the generic Kalman-filter function is called from a higher-level navigation or estimation routine that preprocesses measurement data and post-processes output data. The generic Kalman-filter function uses the aforementioned data structures and five implementation- specific subfunctions, which have been developed by the user on

  18. Generalized Design Method for Voltage-Controlled Current-Mode Multifunction Filters

    Directory of Open Access Journals (Sweden)

    I. Lattenberg

    2009-11-01

    Full Text Available In the article, the Generalized Current Follower Transconductance Amplifier (GCFTA element for generalized frequency filter design and a novel active element, the Programmable Current Amplifier (PCA for the realization of the current-mode analog blocks, are presented. The paper also presents a method of general frequency filter design, whereas the basic circuit is a general autonomous circuit using GCFTA, PCA elements and general admittances. The properties of the proposed filter have been verified using PSPICE simulations.

  19. Towards the simulation of manufacturing effects on multi-layered filter media

    OpenAIRE

    Kabel, Matthias; Kirsch, Ralf; Staub, Sarah

    2016-01-01

    Over the years, specialized simulation software for filter elements has proven to be an effective tool for the optimization of the design of filter elements. The complex interplay of fluid flow, dust transport and deposition and flow-induced deformation of the media has to be described in terms of mathematical models and treated with appropriate numerical algorithms. The center of these considerations is the final filter element and therefore, the approach relies on material and model paramet...

  20. A Self-commissioning Notch Filter for Active Damping in a Three-Phase LCL -Filter-Based Grid-Tie Converter

    DEFF Research Database (Denmark)

    Pena-Alzola, Rafael; Liserre, Marco; Blaabjerg, Frede

    2014-01-01

    LCL-filters are a cost-effective solution to mitigate harmonic current content in grid-tie converters. In order to avoid stability problems, the resonance frequency of LCL-filters can be damped with active techniques that remove dissipative elements but increase control complexity. A notch filter...

  1. Spot- Zombie Filtering System

    OpenAIRE

    Arathy Rajagopal; B. Geethanjali; Arulprakash P

    2015-01-01

    A major security challenge on the Internet is the existence of the large number of compromised machines. Such machines have been increasingly used to launch various security attacks including spamming and spreading malware, DDoS, and identity theft. These compromised machines are called "Zombies". In general E-mail applications and providers uses spam filters to filter the spam messages. Spam filtering is a technique for discriminating the genuine message from the spam messages. The attackers...

  2. Hybrid Filter Membrane

    Science.gov (United States)

    Laicer, Castro; Rasimick, Brian; Green, Zachary

    2012-01-01

    Cabin environmental control is an important issue for a successful Moon mission. Due to the unique environment of the Moon, lunar dust control is one of the main problems that significantly diminishes the air quality inside spacecraft cabins. Therefore, this innovation was motivated by NASA s need to minimize the negative health impact that air-suspended lunar dust particles have on astronauts in spacecraft cabins. It is based on fabrication of a hybrid filter comprising nanofiber nonwoven layers coated on porous polymer membranes with uniform cylindrical pores. This design results in a high-efficiency gas particulate filter with low pressure drop and the ability to be easily regenerated to restore filtration performance. A hybrid filter was developed consisting of a porous membrane with uniform, micron-sized, cylindrical pore channels coated with a thin nanofiber layer. Compared to conventional filter media such as a high-efficiency particulate air (HEPA) filter, this filter is designed to provide high particle efficiency, low pressure drop, and the ability to be regenerated. These membranes have well-defined micron-sized pores and can be used independently as air filters with discreet particle size cut-off, or coated with nanofiber layers for filtration of ultrafine nanoscale particles. The filter consists of a thin design intended to facilitate filter regeneration by localized air pulsing. The two main features of this invention are the concept of combining a micro-engineered straight-pore membrane with nanofibers. The micro-engineered straight pore membrane can be prepared with extremely high precision. Because the resulting membrane pores are straight and not tortuous like those found in conventional filters, the pressure drop across the filter is significantly reduced. The nanofiber layer is applied as a very thin coating to enhance filtration efficiency for fine nanoscale particles. Additionally, the thin nanofiber coating is designed to promote capture of

  3. ADVANCED HOT GAS FILTER DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    E.S. Connolly; G.D. Forsythe

    1998-12-22

    Advanced, coal-based power plants will require durable and reliable hot gas filtration systems to remove particulate contaminants from the gas streams to protect downstream components such as turbine blades from erosion damage. It is expected that the filter elements in these systems will have to be made of ceramic materials to withstand goal service temperatures of 1600 F or higher. Recent demonstration projects and pilot plant tests have indicated that the current generation of ceramic hot gas filters (cross-flow and candle configurations) are failing prematurely. Two of the most promising materials that have been extensively evaluated are clay-bonded silicon carbide and alumina-mullite porous monoliths. These candidates, however, have been found to suffer progressive thermal shock fatigue damage, as a result of rapid cooling/heating cycles. Such temperature changes occur when the hot filters are back-pulsed with cooler gas to clean them, or in process upset conditions, where even larger gas temperature changes may occur quickly and unpredictably. In addition, the clay-bonded silicon carbide materials are susceptible to chemical attack of the glassy binder phase that holds the SiC particles together, resulting in softening, strength loss, creep, and eventual failure.

  4. Fundamentals of Stochastic Filtering

    CERN Document Server

    Crisan, Dan

    2008-01-01

    The objective of stochastic filtering is to determine the best estimate for the state of a stochastic dynamical system from partial observations. The solution of this problem in the linear case is the well known Kalman-Bucy filter which has found widespread practical application. The purpose of this book is to provide a rigorous mathematical treatment of the non-linear stochastic filtering problem using modern methods. Particular emphasis is placed on the theoretical analysis of numerical methods for the solution of the filtering problem via particle methods. The book should provide sufficient

  5. Stripe delay filters

    OpenAIRE

    Zakharov, Alexander V.; Ilchenko, Mykhailo Ye.; Trubarov, Igor V.; Pinchuk, Ludmila S.

    2016-01-01

    There are considered constructions of microsized stripe delay filters, which are realized on a basis of ceramic materials with high dielectric permittivity. Delay time of non-minimal phase filters is 7–12 ns at frequencies of 1900 MHz with relative bandwidth of 3.6–3.85%. Filters dimensions are comparable with ones used in portable communication devices. Dimensions of researched three-resonator filter at frequency of 1900 MHz are 8.4×5×2 mm with material dielectric permittivity εr = 92, and 5...

  6. Nanofiber Filters Eliminate Contaminants

    Science.gov (United States)

    2009-01-01

    With support from Phase I and II SBIR funding from Johnson Space Center, Argonide Corporation of Sanford, Florida tested and developed its proprietary nanofiber water filter media. Capable of removing more than 99.99 percent of dangerous particles like bacteria, viruses, and parasites, the media was incorporated into the company's commercial NanoCeram water filter, an inductee into the Space Foundation's Space Technology Hall of Fame. In addition to its drinking water filters, Argonide now produces large-scale nanofiber filters used as part of the reverse osmosis process for industrial water purification.

  7. Ground Testing a Nuclear Thermal Rocket: Design of a sub-scale demonstration experiment

    Energy Technology Data Exchange (ETDEWEB)

    David Bedsun; Debra Lee; Margaret Townsend; Clay A. Cooper; Jennifer Chapman; Ronald Samborsky; Mel Bulman; Daniel Brasuell; Stanley K. Borowski

    2012-07-01

    In 2008, the NASA Mars Architecture Team found that the Nuclear Thermal Rocket (NTR) was the preferred propulsion system out of all the combinations of chemical propulsion, solar electric, nuclear electric, aerobrake, and NTR studied. Recently, the National Research Council committee reviewing the NASA Technology Roadmaps recommended the NTR as one of the top 16 technologies that should be pursued by NASA. One of the main issues with developing a NTR for future missions is the ability to economically test the full system on the ground. In the late 1990s, the Sub-surface Active Filtering of Exhaust (SAFE) concept was first proposed by Howe as a method to test NTRs at full power and full duration. The concept relied on firing the NTR into one of the test holes at the Nevada Test Site which had been constructed to test nuclear weapons. In 2011, the cost of testing a NTR and the cost of performing a proof of concept experiment were evaluated.

  8. Development of a Low-Cost, Subscale Test System to Evaluate Particle Impingement Erosion in Nozzle Ablative Materials

    Science.gov (United States)

    Lansing, Matthew D.; Lawrence, Timothy W.; Gordon, Gail H. (Technical Monitor)

    2001-01-01

    This viewgraph presentation gives an overview on the development of a low-cost, subscale test system to evaluate particle impingement erosion in nozzle ablative materials. Details are given on the need for a new test bed, solid fuel torch components, solid fuel torch test, additional uses for the solid fuel torch, the development of a supersonic blast tube (SSBT), and particle impingement material discrimination.

  9. The use of Spielberger’s State-Trait Personality Inventory (trait anxiety subscale) with naval subaquatic specialists

    OpenAIRE

    Van Wijk, Charles H

    2014-01-01

    Objectives: Panic behavior poses a particular threat to the health and safety of subaquatic occupational specialists. Trait anxiety has previously been identified as a marker of panic behavior under water, and Spielberger’s State-Trait Personality Inventory (trait anxiety subscale) has been previously used to measure trait anxiety among subaquatic specialists. Using archived data, the trait anxiety scores of subaquatic specialists were analyzed to meet 3 objectives: 1stly – to develop a trait...

  10. NONDESTRUCTIVE EVALUATION OF CERAMIC CANDLE FILTERS

    Energy Technology Data Exchange (ETDEWEB)

    Roger H.L. Chen, Ph.D.; Alejandro Kiriakidis

    1999-09-01

    Nondestructive evaluation (NDE) techniques have been used to reduce the potential mechanical failures and to improve the reliability of a structure. Failure of a structure is usually initiated at some type of flaw in the material. NDE techniques have been developed to determine the presence of flaws larger than an acceptable size and to estimate the remaining stiffness of a damaged structure (Chen, et. al, 1995). Ceramic candle filters have been tested for use in coal-fueled gas turbine systems. They protect gas turbine components from damage due to erosion. A total of one hundred and one candle filters were nondestructively evaluated in this study. Ninety-eight ceramic candle filters and three ceramic composite filters have been nondestructively inspected using dynamic characterization technique. These ceramic filters include twelve unused Coors alumina/mullite, twenty-four unused and fifteen used Schumacher-Dia-Schumalith TF-20, twenty-five unused and nine used Refractron 326, eight unused and three used Refractron 442T, one new Schumacher-T 10-20, and one used Schumacher-Dia-Schumalith F-40. All filters were subjected to a small excitation and the dynamic response was picked up by a piezoelectric accelerometer. The evaluation of experimental results was processed using digital signal analysis technique including various forms of data transformation. The modal parameters for damage assessment for the unexposed (unused) vs. exposed (used) specimen were based on two vibration parameters: natural frequencies and mode shapes. Finite Element models were built for each specimen type to understand its dynamic response. Linear elastic modal analysis was performed using eight nodes, three-dimensional isotropic solid elements. Conclusions based on our study indicate that dynamic characterization is a feasible NDE technique in studying structural properties of ceramic candle filters. It has been shown that the degradation of the filters due to long working hours (or

  11. The Child Behavior Checklist-Obsessive-Compulsive Subscale Detects Severe Psychopathology and Behavioral Problems Among School-Aged Children.

    Science.gov (United States)

    Saad, Laura O; do Rosario, Maria C; Cesar, Raony C; Batistuzzo, Marcelo C; Hoexter, Marcelo Q; Manfro, Gisele G; Shavitt, Roseli G; Leckman, James F; Miguel, Eurípedes C; Alvarenga, Pedro G

    2017-05-01

    The aims of this study were (1) to assess obsessive-compulsive symptoms (OCS) dimensionally in a school-aged community sample and to correlate them with clinical and demographical variables; (2) to determine a subgroup with significant OCS ("at-risk for OCD") using the Child Behavior Checklist (CBCL-OCS) and (3) to compare it with the rest of the sample; (4) To review the CBCL-OCS subscale properties as a screening tool for pediatric OCD. Data from the Brazilian High Risk Cohort were analyzed. The presence and severity of OCS were assessed through the CBCL-OCS subscale. DSM-IV psychiatric diagnoses were obtained by the Developmental and Well-Being Assessment. Behavioral problems were assessed using the Strengths and Difficulties Questionnaire, the Youth Strengths Inventory, and the CBCL internalizing and externalizing behavior subscales. A total of 2512 (mean age: 8.86 ± 1.84 years; 55.0% male) children were included. Moderate correlations were found between OCS severity and functional impairment (r = 0.36, p behavioral problems (p behavioral patterns and psychiatric comorbidities (e.g., tics [odds ratios, OR = 6.41, p approach suggests that the presence of OCS in children is associated with higher rates of comorbidity, behavioral problems, and impairment. The "at-risk for OCD" group defined by the CBCL revealed a group of patients phenotypically similar to full blown OCD.

  12. Randomized Filtering Algorithms

    DEFF Research Database (Denmark)

    Katriel, Irit; Van Hentenryck, Pascal

    2008-01-01

    of AllDifferent and is generalization, the Global Cardinality Constraint. The first delayed filtering scheme is a Monte Carlo algorithm: its running time is superior, in the worst case, to that of enforcing are consistency after every domain event, while its filtering effectiveness is analyzed...

  13. Multilevel ensemble Kalman filter

    KAUST Repository

    Chernov, Alexey

    2016-01-06

    This work embeds a multilevel Monte Carlo (MLMC) sampling strategy into the Monte Carlo step of the ensemble Kalman filter (EnKF). In terms of computational cost vs. approximation error the asymptotic performance of the multilevel ensemble Kalman filter (MLEnKF) is superior to the EnKF s.

  14. Updating the OMERACT filter

    DEFF Research Database (Denmark)

    Wells, George; Beaton, Dorcas E; Tugwell, Peter

    2014-01-01

    The "Discrimination" part of the OMERACT Filter asks whether a measure discriminates between situations that are of interest. "Feasibility" in the OMERACT Filter encompasses the practical considerations of using an instrument, including its ease of use, time to complete, monetary costs, and inter...

  15. Fast Anisotropic Gauss Filtering

    NARCIS (Netherlands)

    Geusebroek, J.M.; Smeulders, A.W.M.; van de Weijer, J.; Heyden, A.; Sparr, G.; Nielsen, M.; Johansen, P.

    2002-01-01

    We derive the decomposition of the anisotropic Gaussian in a one dimensional Gauss filter in the x-direction followed by a one dimensional filter in a non-orthogonal direction phi. So also the anisotropic Gaussian can be decomposed by dimension. This appears to be extremely efficient from a

  16. Vena cava filter; Vena-cava-Filter

    Energy Technology Data Exchange (ETDEWEB)

    Helmberger, T. [Klinikum Bogenhausen, Institut fuer Diagnostische und Interventionelle Radiologie und Nuklearmedizin, Muenchen (Germany)

    2007-05-15

    Fulminant pulmonary embolism is one of the major causes of death in the Western World. In most cases, deep leg and pelvic venous thrombosis are the cause. If an anticoagulant/thrombotic therapy is no longer possible or ineffective, a vena cava filter implant may be indicated if an embolism is threatening. Implantation of the filter is a simple and safe intervention. Nevertheless, it is necessary to take into consideration that the data base for determining the indications for this treatment are very limited. Currently, a reduction in the risk of thromboembolism with the use of filters of about 30%, of recurrences of almost 5% and fatal pulmonary embolism of 1% has been reported, with a risk of up to 20% of filter induced vena cava thrombosis. (orig.) [German] Die fulminante Lungenembolie zaehlt zu den Haupttodesursachen in der westlichen Welt. In der Mehrzahl der Faelle sind tiefe Bein- und Beckenvenenthrombosen ursaechlich verantwortlich. Ist eine antikoagulative/-thrombotische Therapie nicht (mehr) moeglich oder unwirksam, kann bei drohender Emboliegefahr die Vena-cava-Filterimplantation indiziert sein. Die Filterimplantation ist eine einfache und sehr sichere Intervention. Dennoch muss bei der Indikationsstellung beruecksichtigt werden, dass die Datenlage zur Wirksamkeit sehr limitiert ist. So wird aktuell ueber eine Reduktion des Thrombembolierisikos um 30% bei Embolierezidiven von knapp 5% und fatalen Lungenembolien von 1% unter Filterprophylaxe berichtet, bei einem Risiko von bis zu 20% fuer die filterinduzierte Vena-cava-Thrombose. (orig.)

  17. Evaluation of mechanical properties and structural changes of ceramic filter materials for hot gas cleaning under simulated process conditions

    OpenAIRE

    Westerheide, R.; Wehd, C. von der; Rehak, P.; Adler, J.

    2002-01-01

    In the combined cycle technology for advanced coal fired power plants at high temperatures up to 950 °C the removal of particles from the stream to the gas turbine is carried out with ceramic filter elements. These elements consist often of siliceous bonded coarse grained silicon carbide. A stable long term operation of the filter elements leads to the demands on good resistance towards thermal, mechanical and chemical loading. The structure of ceramic filter elements consists usually of a hi...

  18. Analog active filters

    Science.gov (United States)

    Ghausi, M. S.

    1984-01-01

    The evolution of active filters during the time from 1920 to 1980 is considered, taking into account the hardware used to implement a filtering network for voice frequency over 60 years. From 1920 to 1960 the majority of voice-frequency filters was realized as discrete RLC networks. After the development of transistors, it was realized that size and cost reductions could be achieved by replacing the inductors with active networks. In the early 1970's, batch-processed thin-film hybrid integrated circuits began to be employed. The synthesis of transfer functions which are predominantly input/output types is considered. Attention is given to direct realizations, synthesis using component simulation, cascade synthesis, multiple-loop feedback design, active-R and active-C filters, aspects of sensitivity, and switched-capacitor filters.

  19. Learning Separable Filters.

    Science.gov (United States)

    Sironi, Amos; Tekin, Bugra; Rigamonti, Roberto; Lepetit, Vincent; Fua, Pascal

    2015-01-01

    Learning filters to produce sparse image representations in terms of over-complete dictionaries has emerged as a powerful way to create image features for many different purposes. Unfortunately, these filters are usually both numerous and non-separable, making their use computationally expensive. In this paper, we show that such filters can be computed as linear combinations of a smaller number of separable ones, thus greatly reducing the computational complexity at no cost in terms of performance. This makes filter learning approaches practical even for large images or 3D volumes, and we show that we significantly outperform state-of-the-art methods on the curvilinear structure extraction task, in terms of both accuracy and speed. Moreover, our approach is general and can be used on generic convolutional filter banks to reduce the complexity of the feature extraction step.

  20. Development and validation of subscales to assess perceived support for self-management of mood or emotional problems: Results from a randomized trial.

    Science.gov (United States)

    McCusker, Jane; Haggerty, Jeannie; De Raad, Manon; Belzile, Eric; Bouharaoui, Fatima; Beaulieu, Christine; Yaffe, Mark; Ciampi, Antonio

    2017-06-10

    To validate 2 new patient-reported measures of self-management support from health professionals for mood and emotional problems. The sample comprised primary care patients with chronic physical conditions and co-morbid depressive symptoms enrolled in a randomized trial of telephone coaching of a depression self-care intervention (n=120). At 6-month follow-up, patients completed 2 subscales with respect to support for self-management of their chronic physical condition(s): 1) Self-Management Information (SMInfo-Phys); and 2) Care Plan (CP-Phys) and equivalent subscales adapted to assess self-management support for mood and emotional problems: SMInfo-Mood and CP-Mood. Subscale scoring was assessed with Item Response Theory (IRT) analysis. Convergent validity of the mood subscales was assessed. The sensitivity of the mood and physical condition subscales to mental health interventions was assessed with generalized estimating equations (GEE). The mood subscales were associated with relevant measures of perceived unmet mental health needs. Both SMInfo-Mood and CP-Mood were sensitive to the coaching intervention; CP-Mood was also sensitive to receipt of depression treatment outside the trial. This study provides preliminary evidence for the validity of the 2 new subscales. The subscales may be used to assess perceived health professional support for self-management of mood and emotional problems. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. A Simple Candle Filter Safeguard Device

    Energy Technology Data Exchange (ETDEWEB)

    Hurley, J.P.; Henderson, A.K.; Swanson, M.L.

    2002-09-18

    In order to reach the highest possible efficiencies in a coal-fired turbine-based power system, the turbine should be directly fired with the products of coal utilization. Two main designs employ these turbines: those based on pressurized fluidized-bed combustors (PFBCs) and those based on integrated gasification combined cycles (IGCCs). In both designs, the suspended particulates, or dust, must be cleaned from the gas before it enters the turbine to prevent fouling and erosion of the blades. To produce the cleanest gas, barrier filters are being developed and are in commercial use. Barrier filters are composed of porous, high-temperature materials that allow the hot gas to pass but collect the dust on the surface. The three main configurations are candle, cross-flow, and tube. Both candle and tube filters have been tested extensively. They are primarily composed of coarsely porous ceramic that serves as a structural support, overlain with a thin, microporous ceramic layer o n the dirty gas side that serves as the primary filter surface. They are highly efficient at removing particulate matter from the gas stream and, because of their ceramic construction, are resistant to gas and ash corrosion. However, ceramics are brittle, and individual elements can fail, allowing the particulates to pass through the hole left by the filter element and erode the turbine. Because of the possibility of occasional filter breakage, safeguard devices (SGDs) must be employed to prevent the dust streaming through broken filters from reaching the turbine. The Energy & Environmental Research Center (EERC) safeguard device is composed of three main parts: the ceramic substrate, the adhesive coating, and the safeguard device housing. This report describes the development and laboratory testing of each of those parts as well as the bench-scale performance of both types of complete SGDs.

  2. Current Mode Biquad Filter with Minimum Component Count

    Directory of Open Access Journals (Sweden)

    Bhartendu Chaturvedi

    2011-01-01

    Full Text Available The paper presents a new current mode biquadratic filter with one input and three outputs using differential voltage current conveyor (DVCC and four passive components. The proposed circuit can simultaneously realize low-pass, band-pass, and high-pass filter functions without changing the circuit topology and passive elements. The circuit exhibits a good frequency performance and low-sensitivity figures. PSPICE simulation using 0.5 μm CMOS parameters are given to validate the proposed circuit. The circuit provides a simple yet novel solution to the current-mode filtering after appropriate incorporation of current sensing elements in form of current buffers.

  3. 3-D woven, mullite matrix, composite filter

    Energy Technology Data Exchange (ETDEWEB)

    Lane, J.E.; Painter, C.J.; Radford, K.C. LeCostaouec, J.F.

    1995-12-01

    Westinghouse, with Techniweave as a major subcontractor, is conducting a three-phase program aimed at providing advanced candle filters for a 1996 pilot scale demonstration in one of the two hot gas filter systems at Southern Company Service`s Wilsonville PSD Facility. The Base Program (Phases I and II) objective is to develop and demonstrate the suitability of the Westinghouse/Techniweave next generation composite candle filter for use in Pressurized Fluidized Bed Combustion (PFBC) and/or Integrated Gasification Combined Cycle (IGCC) power generation systems. The Optional Task (Phase M, Task 5) objective is to fabricate, inspect and ship to Wilsonville Hot gas particulate filters are key components for the successful commercializaion of advanced coal-based power-generation systems such as Pressurized Fluidized-bed Combustion (PFBC), including second-generation PFBC, and Integrated Gasification Combined Cycles (IGCC). Current generation monolithic ceramic filters are subject to catastrophic failure because they have very low resistance to crack propagation. To overcome this problem, a damage-tolerant ceramic filter element is needed.

  4. Transient Heating and Thermomechanical Stress Modeling of Ceramic HEPA Filters

    Energy Technology Data Exchange (ETDEWEB)

    Bogle, Brandon [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kelly, James [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Haslam, Jeffrey [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-29

    The purpose of this report is to showcase an initial finite-element analysis model of a ceramic High-Efficiency Particulate (HEPA) Air filter design. Next generation HEPA filter assemblies are being developed at LLNL to withstand high-temperature fire scenarios by use of ceramics and advanced materials. The filters are meant for use in radiological and nuclear facilities, and are required to survive 500°C fires over an hour duration. During such conditions, however, collecting data under varying parameters can be challenging; therefore, a Finite Element Analysis model of the filter was conducted using COMSOL ® Multiphysics to analyze the effects of fire. Finite Element Analysis (FEA) modelling offers several opportunities: researchers can quickly and easily consider impacts of potential design changes, material selection, and flow characterization on filter performance. Specifically, this model provides stress references for the sealant at high temperatures. Modeling of full filter assemblies was deemed inefficient given the computational requirements, so a section of three tubes from the assembly was modeled. The model looked at the transient heating and thermomechanical stress development during a 500°C air flow at 6 CFM. Significant stresses were found at the ceramic-metal interfaces of the filter, and conservative temperature profiles at locations of interest were plotted. The model can be used for the development of sealants that minimize stresses at the ceramic-metal interface. Further work on the model would include the full filter assembly and consider heat losses to make more accurate predictions.

  5. Plasma filtering techniques for nuclear waste remediation.

    Science.gov (United States)

    Gueroult, Renaud; Hobbs, David T; Fisch, Nathaniel J

    2015-10-30

    Nuclear waste cleanup is challenged by the handling of feed stocks that are both unknown and complex. Plasma filtering, operating on dissociated elements, offers advantages over chemical methods in processing such wastes. The costs incurred by plasma mass filtering for nuclear waste pretreatment, before ultimate disposal, are similar to those for chemical pretreatment. However, significant savings might be achieved in minimizing the waste mass. This advantage may be realized over a large range of chemical waste compositions, thereby addressing the heterogeneity of legacy nuclear waste. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Dust removal and filter technology. Entstaubungs- und Filtertechnik

    Energy Technology Data Exchange (ETDEWEB)

    Stockmann, H.W. (DMT-Gesellschaft fuer Forschung und Pruefung mbH, Essen (Germany). DMT-Institut fuer Staubbekaempfung, Gefahrstoffe und Ergonomie); Henke, B. (DMT-Gesellschaft fuer Forschung und Pruefung mbH, Essen (Germany). DMT-Institut fuer Staubbekaempfung, Gefahrstoffe und Ergonomie)

    1991-01-01

    New approaches were adopted in filter technology to respond to technological changes in mechanized mining and to allow perfect dust removal in keeping with occupational hygiene requirements. Self-supporting filter materials based on ceramic fibres and synthetic granulates were taken to develop filter elements allowing lamination to enhance their separation-active surface area. Filter materials made from thermally fixed fibre nonwovens were processed to form plicated filter bags of the same structural volume but with a surface area increased by a factor of 2.5. Integrated inlet nozzles were developed to allow these elements to be cleaned of dust deposits. These nozzles were also studied in basic filter-technology tests. A test rig supplied design findings which were included in a study to develop new generations of dedusters. A reduction of design volume and an increase of through-put rate greater than 20% could be predicted. Service tests with modified filter materials were run for ventilation-air dust dust removal both for whole faces and for face segments. The benefits of filter technology for face, face opening and drifting were highlighted. New methods for wetting and transport of the dust removed from the dedusters were developed. New concepts of exhaust-air filter separators allow flat storage bunkers to be used in pneumatic conveyance of building materials at the face. (orig.)

  7. Ceramic fiber reinforced filter

    Science.gov (United States)

    Stinton, David P.; McLaughlin, Jerry C.; Lowden, Richard A.

    1991-01-01

    A filter for removing particulate matter from high temperature flowing fluids, and in particular gases, that is reinforced with ceramic fibers. The filter has a ceramic base fiber material in the form of a fabric, felt, paper of the like, with the refractory fibers thereof coated with a thin layer of a protective and bonding refractory applied by chemical vapor deposition techniques. This coating causes each fiber to be physically joined to adjoining fibers so as to prevent movement of the fibers during use and to increase the strength and toughness of the composite filter. Further, the coating can be selected to minimize any reactions between the constituents of the fluids and the fibers. A description is given of the formation of a composite filter using a felt preform of commercial silicon carbide fibers together with the coating of these fibers with pure silicon carbide. Filter efficiency approaching 100% has been demonstrated with these filters. The fiber base material is alternately made from aluminosilicate fibers, zirconia fibers and alumina fibers. Coating with Al.sub.2 O.sub.3 is also described. Advanced configurations for the composite filter are suggested.

  8. Far infrared interference filters.

    Science.gov (United States)

    Varma, S P; Möller, K D

    1969-08-01

    Capacitive meshes for far ir, low pass filters are prepared from Cu layers on 2.5 micro plastic film. The properties of these meshes of different mesh constants g with their different combinations in two-mesh, fourmesh, and eight-mesh filters are studied in the spectral region 160 cm(-1) to 10 cm(-1) by the use of a grating spectrometer. The applications of these meshes as low pass filters in the far ir spectral region in a grating spectrometer are described.

  9. Circuits and filters handbook

    CERN Document Server

    Chen, Wai-Kai

    2003-01-01

    A bestseller in its first edition, The Circuits and Filters Handbook has been thoroughly updated to provide the most current, most comprehensive information available in both the classical and emerging fields of circuits and filters, both analog and digital. This edition contains 29 new chapters, with significant additions in the areas of computer-aided design, circuit simulation, VLSI circuits, design automation, and active and digital filters. It will undoubtedly take its place as the engineer's first choice in looking for solutions to problems encountered in the design, analysis, and behavi

  10. EMI filter design

    CERN Document Server

    Ozenbaugh, Richard Lee

    2011-01-01

    With today's electrical and electronics systems requiring increased levels of performance and reliability, the design of robust EMI filters plays a critical role in EMC compliance. Using a mix of practical methods and theoretical analysis, EMI Filter Design, Third Edition presents both a hands-on and academic approach to the design of EMI filters and the selection of components values. The design approaches covered include matrix methods using table data and the use of Fourier analysis, Laplace transforms, and transfer function realization of LC structures. This edition has been fully revised

  11. DC-pass filter design with notch filters superposition for CPW rectenna at low power level

    Science.gov (United States)

    Rivière, J.; Douyère, A.; Alicalapa, F.; Luk, J.-D. Lan Sun

    2016-03-01

    In this paper the challenging coplanar waveguide direct current (DC) pass filter is designed, analysed, fabricated and measured. As the ground plane and the conductive line are etched on the same plane, this technology allows the connection of series and shunt elements to the active devices without via holes through the substrate. Indeed, this study presents the first step in the optimization of a complete rectenna in coplanar waveguide (CPW) technology: key element of a radio frequency (RF) energy harvesting system. The measurement of the proposed filter shows good performance in the rejection of F0=2.45 GHz and F1=4.9 GHz. Additionally, a harmonic balance (HB) simulation of the complete rectenna is performed and shows a maximum RF-to-DC conversion efficiency of 37% with the studied DC-pass filter for an input power of 10 µW at 2.45 GHz.

  12. Very High Speed Discrete Time Optical Signal Generation and Filtering

    Science.gov (United States)

    Narayan, Vishwa

    Optical lattice filters constitute a class of devices that generate and operate upon high bandwidth optical signals. This dissertation describes the design, analysis, construction and testing of such devices. We derive elegant z-transform based filter transfer functions and develop a convenient state variable based scattering matrix filter description. A variety of filters are designed and analyzed. We also design locally optimal optical lattice filters with mirror imperfections such as losses and finite reflectivity round-off error. We conduct a quantitative sensitivity analysis of the degrading effects of these imperfections on system performance, and study the distorting effects of phase error on pulse train shape. Experimentally, we use mirror based optical lattice filters to generate 667 GHz repetition rate pulse bursts with step and ramp envelopes, and coded pulse bursts. We also demonstrate the quadrupling and octupling of the 76 MHz repetition rate of a mode-locked laser. We demonstrate the low pass filtering property of optical lattice filters by realizing a high speed discrete time optical integrator. Step functions are integrated to ramps, and ramps to quadratics, at 667 GHz. We also constructed a mechanical variable repetition rate filter with a tuning range of 2.14 to 100 GHz. We design and analyze a gain based mirror filter with active gain elements. Small signal linear constant gain tends to improve filter performance by increasing the output, and reducing fluctuations in the frequency response. We study the behavior of these filters at the stability limit, characterized by large fluctuations in the frequency response. Optical lattice filters may be used as wavelength multiplexers/demultiplexers in lightwave systems, as variable repetition rate pulse train generators for tunable repetition rate optical spectroscopy, as optical clock generators, and as discrete time/analog optical signal filters.

  13. DEVELOPMENT OF AN ADHESIVE CANDLE FILTER SAFEGUARD DEVICE

    Energy Technology Data Exchange (ETDEWEB)

    John P. Hurley; Ann K. Henderson; Jan W. Nowok; Michael L. Swanson

    2002-01-01

    In order to reach the highest possible efficiencies in a coal-fired turbine-based power system, the turbine should be directly fired with the products of coal conversion. Two main types of systems employ these turbines: those based on pressurized fluidized-bed combustors and those based on integrated gasification combined cycles. In both systems, suspended particulates must be cleaned from the gas stream before it enters the turbine so as to prevent fouling and erosion of the turbine blades. To produce the cleanest gas, barrier filters are being developed and are in use in several facilities. Barrier filters are composed of porous, high-temperature materials that allow the hot gas to pass but collect the particulates on the surface. The three main configurations of the barrier filters are candle, cross-flow, and tube filters. Both candle and tube filters have been tested extensively. They are composed of coarsely porous ceramic that serves as a structural support, overlain with a thin, microporous ceramic layer on the dirty gas side that serves as the primary filter surface. They are highly efficient at removing particulate matter from the gas stream and, because of their ceramic construction, are resistant to gas and ash corrosion. However, ceramics are brittle and individual elements can fail, allowing particulates to pass through the hole left by the filter element and erode the turbine. Preventing all failure of individual ceramic filter elements is not possible at the present state of development of the technology. Therefore, safeguard devices (SGDs) must be employed to prevent the particulates streaming through occasional broken filters from reaching the turbine. However, the SGD must allow for the free passage of gas when it is not activated. Upon breaking of a filter, the SGD must either mechanically close or quickly plug with filter dust to prevent additional dust from reaching the turbine. Production of a dependable rapidly closing autonomous mechanical

  14. Paul Rodgersi filter Kohilas

    Index Scriptorium Estoniae

    2000-01-01

    28. I Kohila keskkoolis kohaspetsiifiline skulptuur ja performance "Filter". Kooli 130. aastapäeva tähistava ettevõtmise eesotsas oli skulptor Paul Rodgers ja kaks viimase klassi noormeest ئ Marko Heinmäe, Hendrik Karm.

  15. Perspectives on Nonlinear Filtering

    KAUST Repository

    Law, Kody

    2015-01-07

    The solution to the problem of nonlinear filtering may be given either as an estimate of the signal (and ideally some measure of concentration), or as a full posterior distribution. Similarly, one may evaluate the fidelity of the filter either by its ability to track the signal or its proximity to the posterior filtering distribution. Hence, the field enjoys a lively symbiosis between probability and control theory, and there are plenty of applications which benefit from algorithmic advances, from signal processing, to econometrics, to large-scale ocean, atmosphere, and climate modeling. This talk will survey some recent theoretical results involving accurate signal tracking with noise-free (degenerate) dynamics in high-dimensions (infinite, in principle, but say d between 103 and 108 , depending on the size of your application and your computer), and high-fidelity approximations of the filtering distribution in low dimensions (say d between 1 and several 10s).

  16. Updating the OMERACT filter

    DEFF Research Database (Denmark)

    D'Agostino, Maria-Antonietta; Boers, Maarten; Kirwan, John

    2014-01-01

    OBJECTIVE: The Outcome Measures in Rheumatology (OMERACT) Filter provides a framework for the validation of outcome measures for use in rheumatology clinical research. However, imaging and biochemical measures may face additional validation challenges because of their technical nature. The Imagin...

  17. Compact photonic spin filters

    Science.gov (United States)

    Ke, Yougang; Liu, Zhenxing; Liu, Yachao; Zhou, Junxiao; Shu, Weixing; Luo, Hailu; Wen, Shuangchun

    2016-10-01

    In this letter, we propose and experimentally demonstrate a compact photonic spin filter formed by integrating a Pancharatnam-Berry phase lens (focal length of ±f ) into a conventional plano-concave lens (focal length of -f). By choosing the input port of the filter, photons with a desired spin state, such as the right-handed component or the left-handed one, propagate alone its original propagation direction, while the unwanted spin component is quickly diverged after passing through the filter. One application of the filter, sorting the spin-dependent components of vector vortex beams on higher-order Poincaré sphere, is also demonstrated. Our scheme provides a simple method to manipulate light, and thereby enables potential applications for photonic devices.

  18. ADVANCED SECOND GENERATION CERAMIC CANDLE FILTERS

    Energy Technology Data Exchange (ETDEWEB)

    M.A. Alvin

    2002-01-31

    Through sponsorship from the Department of Energy's National Energy Technology Laboratory (DOE/NETL), development and manufacture of advanced second generation candle filters was undertaken in the early 1990's. Efforts were primarily focused on the manufacture of fracture toughened, 1.5 m, continuous fiber ceramic composite (CFCC) and filament wound candle filters by 3M, McDermott, DuPont Lanxide Composites, and Techniweave. In order to demonstrate long-term thermal, chemical, and mechanical stability of the advanced second generation candle filter materials, Siemens Westinghouse initiated high temperature, bench-scale, corrosion testing of 3M's CVI-SiC and DuPont's PRD-66 mini-candles, and DuPont's CFCC SiC-SiC and IF&P Fibrosic{sup TM} coupons under simulated, pressurized fluidized-bed combustion (PFBC) conditions. This effort was followed by an evaluation of the mechanical and filtration performance of the advanced second generation filter elements in Siemens Westinghouse's bench-scale PFBC test facility in Pittsburgh, Pennsylvania. Arrays of 1.4-1.5 m 3M CVI-SiC, DuPont PRD-66, DuPont SiC-SiC, and IF&P Fibrosic{sup TM} candles were subjected to steady state process operating conditions, increased severity thermal transients, and accelerated pulse cycling test campaigns which represented {approx}1760 hours of equivalent filter operating life. Siemens Westinghouse subsequently participated in early material surveillance programs which marked entry of the 3M CVI-SiC and DuPont PRD-66 candle filters in Siemens Westinghouse Advanced Particulate Filtration (APF) system at the American Electric Power (AEP) Tidd Demonstration Plant in Brilliant, Ohio. Siemens Westinghouse then conducted an extended, accelerated life, qualification program, evaluating the performance of the 3M, McDermott, and Techniweave oxide-based CFCC filter elements, modified DuPont PRD-66 elements, and the Blasch, Scapa Cerafil{sup TM}, and Specific Surface monolithic

  19. Filtered stochastic calculus

    OpenAIRE

    Lenczewski, Romuald

    2001-01-01

    By introducing a color filtration to the multiplicity space, we extend the quantum Ito calculus on multiple symmetric Fock space to the framework of filtered adapted biprocesses. In this new notion of adaptedness,``classical'' time filtration makes the integrands similar to adapted processes, whereas ``quantum'' color filtration produces their deviations from adaptedness. An important feature of this calculus, which we call filtered stochastic calculus, is that it provides an explicit interpo...

  20. Inorganic UV filters

    Directory of Open Access Journals (Sweden)

    Eloísa Berbel Manaia

    2013-06-01

    Full Text Available Nowadays, concern over skin cancer has been growing more and more, especially in tropical countries where the incidence of UVA/B radiation is higher. The correct use of sunscreen is the most efficient way to prevent the development of this disease. The ingredients of sunscreen can be organic and/or inorganic sun filters. Inorganic filters present some advantages over organic filters, such as photostability, non-irritability and broad spectrum protection. Nevertheless, inorganic filters have a whitening effect in sunscreen formulations owing to the high refractive index, decreasing their esthetic appeal. Many techniques have been developed to overcome this problem and among them, the use of nanotechnology stands out. The estimated amount of nanomaterial in use must increase from 2000 tons in 2004 to a projected 58000 tons in 2020. In this context, this article aims to analyze critically both the different features of the production of inorganic filters (synthesis routes proposed in recent years and the permeability, the safety and other characteristics of the new generation of inorganic filters.

  1. Toxic Elements

    DEFF Research Database (Denmark)

    Hajeb, Parvaneh; Shakibazadeh, Shahram; Sloth, Jens Jørgen

    2016-01-01

    Food is considered the main source of toxic element (arsenic, cadmium, lead, and mercury) exposure to humans, and they can cause major public health effects. In this chapter, we discuss the most important sources for toxic element in food and the foodstuffs which are significant contributors...... to human exposure. The occurrence of each element in food classes from different regions is presented. Some of the current toxicological risk assessments on toxic elements, the human health effect of each toxic element, and their contents in the food legislations are presented. An overview of analytical...... techniques and challenges for determination of toxic elements in food is also given....

  2. Low exhaust temperature electrically heated particulate matter filter system

    Science.gov (United States)

    Gonze, Eugene V [Pinckney, MI; Paratore, Jr., Michael J.; Bhatia, Garima [Bangalore, IN

    2012-02-14

    A system includes a particulate matter (PM) filter, a sensor, a heating element, and a control module. The PM filter includes with an upstream end that receives exhaust gas, a downstream end and multiple zones. The sensor detects a temperature of the exhaust gas. The control module controls current to the heating element to convection heat one of the zones and initiate a regeneration process. The control module selectively increases current to the heating element relative to a reference regeneration current level when the temperature is less than a predetermined temperature.

  3. Classification of quality of life subscales within the ICF framework in burn research: identifying overlaps and gaps.

    Science.gov (United States)

    Meirte, J; van Loey, N E E; Maertens, K; Moortgat, P; Hubens, G; Van Daele, U

    2014-11-01

    Quality of life (QOL) is one of the leading outcomes in burn care research. This study classifies subscales of common QOL measures within the International Classification of Functioning disability and health (ICF) framework to determine to which extent the measures are complementary or overlapping and to investigate whether the instruments are able to describe the full spectrum of patients' functioning. A literature search was performed to determine the most frequently used questionnaires in burn research. The subscales of the three mostly used questionnaires were classified within the ICF framework. Two generic measures, the Short Form-36 items (SF-36) and the European Quality of Life 5 Dimensions (EQ-5D), and a disease specific measure, the Burn Specific Health Scale-Brief (BSHS-B), were analyzed. The BSHS-B covered most domains and was the only scale that included personal factors. The SF-36 included only one domain in the activity limitations and similar to the EQ-5D no contextual factors were included. Environmental factors were not addressed in the questionnaires, even though these may have an impact on the quality of life in patients with burns. To capture the full spectrum of dysfunctioning a combination of the BSHS-B with a generic questionnaire seems obligatory. However still some domains of functioning remain uncovered. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  4. Large scale finite element solvers for the large eddy simulation of incompressible turbulent flows

    OpenAIRE

    Colomés Gené, Oriol

    2016-01-01

    In this thesis we have developed a path towards large scale Finite Element simulations of turbulent incompressible flows. We have assessed the performance of residual-based variational multiscale (VMS) methods for the large eddy simulation (LES) of turbulent incompressible flows. We consider VMS models obtained by different subgrid scale approximations which include either static or dynamic subscales, linear or nonlinear multiscale splitting, and different choices of the subscale space. W...

  5. Varactor-tuned Substrate Integrated Evanescent Filter

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Acar, Öncel; Dong, Yunfeng

    Evanescent mode waveguides allow for more compact microwave component design in comparison to the traditional fundamental mode waveguide technology. Evanescent waveguides can be integrated into a dielectric substrate in order to further reduce the mass and volume. Unfortunately, traditional reali......, fabricated and tested in order to validate the developed filter models as well as the implemented realization method. The filter structure as well as its tuning are shown in Figure 1....... is considered. In contrast to other methods described in the literature, it avoids etching split ring resonators in the metal layer of the SIW. The filters presented here use varactors as tuning elements. The varactors (as well as DC decoupling circuits) are mounted on the surface of PCB bringing the lower...... metal layer of the waveguide to the top layer with metalized via holes. The present filters are analyzed using models based on impedance matrix representation. The developed models allow computationally efficient and relatively accurate prediction of the filter behavior in a wide frequency range (at...

  6. Choosing and using astronomical filters

    CERN Document Server

    Griffiths, Martin

    2014-01-01

    As a casual read through any of the major amateur astronomical magazines will demonstrate, there are filters available for all aspects of optical astronomy. This book provides a ready resource on the use of the following filters, among others, for observational astronomy or for imaging: Light pollution filters Planetary filters Solar filters Neutral density filters for Moon observation Deep-sky filters, for such objects as galaxies, nebulae and more Deep-sky objects can be imaged in much greater detail than was possible many years ago. Amateur astronomers can take

  7. Spatial filters for focusing ultrasound images

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt; Gori, Paola

    2001-01-01

    Traditionally focusing is done by taking out one sample in the received signal from each transducer element and then sum these signals. This method does not take into account the temporal or spatial spread of the received signal from a point scatterer and does not make an optimal focus of the data...... for beamforming the received RF signals from the individual transducer elements. The matched filter is applied on RF signals from individual transducer elements, thus properly taking into account the spatial spread of the received signal. The method can be applied to any transducer and can also be used...... for synthetic aperture imaging for single element transducers. It is evaluated using the Field II program. Data from a single 3 MHz transducer focused at a distance of 80 mm is processed. Far from the transducer focal region, the processing greatly improves the image resolution: the lateral slice...

  8. Filters for cathodic arc plasmas

    Science.gov (United States)

    Anders, Andre; MacGill, Robert A.; Bilek, Marcela M. M.; Brown, Ian G.

    2002-01-01

    Cathodic arc plasmas are contaminated with macroparticles. A variety of magnetic plasma filters has been used with various success in removing the macroparticles from the plasma. An open-architecture, bent solenoid filter, with additional field coils at the filter entrance and exit, improves macroparticle filtering. In particular, a double-bent filter that is twisted out of plane forms a very compact and efficient filter. The coil turns further have a flat cross-section to promote macroparticle reflection out of the filter volume. An output conditioning system formed of an expander coil, a straightener coil, and a homogenizer, may be used with the magnetic filter for expanding the filtered plasma beam to cover a larger area of the target. A cathodic arc plasma deposition system using this filter can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

  9. Sensory pollution from bag filters, carbon filters and combinations.

    Science.gov (United States)

    Bekö, G; Clausen, G; Weschler, C J

    2008-02-01

    Used ventilation filters are a major source of sensory pollutants in air handling systems. The objective of the present study was to evaluate the net effect that different combinations of filters had on perceived air quality after 5 months of continuous filtration of outdoor suburban air. A panel of 32 subjects assessed different sets of used filters and identical sets consisting of new filters. Additionally, filter weights and pressure drops were measured at the beginning and end of the operation period. The filter sets included single EU5 and EU7 fiberglass filters, an EU7 filter protected by an upstream pre-filter (changed monthly), an EU7 filter protected by an upstream activated carbon (AC) filter, and EU7 filters with an AC filter either downstream or both upstream and downstream. In addition, two types of stand-alone combination filters were evaluated: a bag-type fiberglass filter that contained AC and a synthetic fiber cartridge filter that contained AC. Air that had passed through used filters was most acceptable for those sets in which an AC filter was used downstream of the particle filter. Comparable air quality was achieved with the stand-alone bag filter that contained AC. Furthermore, its pressure drop changed very little during the 5 months of service, and it had the added benefit of removing a large fraction of ozone from the airstream. If similar results are obtained over a wider variety of soiling conditions, such filters may be a viable solution to a long recognized problem. The present study was designed to address the emission of sensory offending pollutants from loaded ventilation filters. The goal was to find a low-polluting solution from commercially available products. The results indicate that the use of activated carbon (AC) filters downstream of fiberglass bag filters can reduce the degradation of air quality that occurs with increasing particle loading. A more practical solution, yet comparably effective, is a stand-alone particle

  10. A comparative validation of the abbreviated Apathy Evaluation Scale (AES-10) with the Neuropsychiatric Inventory apathy subscale against diagnostic criteria of apathy.

    NARCIS (Netherlands)

    Leontjevas, R.; Evers-Stephan, A.; Smalbrugge, M.; Pot, A.M.; Thewissen, V.; Gerritsen, D.L.; Koopmans, R.T.C.M.

    2012-01-01

    OBJECTIVE: To compare the Neuropsychiatric Inventory apathy subscale (NPIa) with the abbreviated Apathy Evaluation Scale (AES-10) on discriminant validity and on their performance to distinguish residents as apathetic or nonapathetic. DESIGN: Cross-sectional design. SETTING: Nursing home.

  11. Multilevel ensemble Kalman filtering

    KAUST Repository

    Hoel, Haakon

    2016-01-08

    The ensemble Kalman filter (EnKF) is a sequential filtering method that uses an ensemble of particle paths to estimate the means and covariances required by the Kalman filter by the use of sample moments, i.e., the Monte Carlo method. EnKF is often both robust and efficient, but its performance may suffer in settings where the computational cost of accurate simulations of particles is high. The multilevel Monte Carlo method (MLMC) is an extension of classical Monte Carlo methods which by sampling stochastic realizations on a hierarchy of resolutions may reduce the computational cost of moment approximations by orders of magnitude. In this work we have combined the ideas of MLMC and EnKF to construct the multilevel ensemble Kalman filter (MLEnKF) for the setting of finite dimensional state and observation spaces. The main ideas of this method is to compute particle paths on a hierarchy of resolutions and to apply multilevel estimators on the ensemble hierarchy of particles to compute Kalman filter means and covariances. Theoretical results and a numerical study of the performance gains of MLEnKF over EnKF will be presented. Some ideas on the extension of MLEnKF to settings with infinite dimensional state spaces will also be presented.

  12. Multilevel Mixture Kalman Filter

    Directory of Open Access Journals (Sweden)

    Xiaodong Wang

    2004-11-01

    Full Text Available The mixture Kalman filter is a general sequential Monte Carlo technique for conditional linear dynamic systems. It generates samples of some indicator variables recursively based on sequential importance sampling (SIS and integrates out the linear and Gaussian state variables conditioned on these indicators. Due to the marginalization process, the complexity of the mixture Kalman filter is quite high if the dimension of the indicator sampling space is high. In this paper, we address this difficulty by developing a new Monte Carlo sampling scheme, namely, the multilevel mixture Kalman filter. The basic idea is to make use of the multilevel or hierarchical structure of the space from which the indicator variables take values. That is, we draw samples in a multilevel fashion, beginning with sampling from the highest-level sampling space and then draw samples from the associate subspace of the newly drawn samples in a lower-level sampling space, until reaching the desired sampling space. Such a multilevel sampling scheme can be used in conjunction with the delayed estimation method, such as the delayed-sample method, resulting in delayed multilevel mixture Kalman filter. Examples in wireless communication, specifically the coherent and noncoherent 16-QAM over flat-fading channels, are provided to demonstrate the performance of the proposed multilevel mixture Kalman filter.

  13. Filters for Submillimeter Electromagnetic Waves

    Science.gov (United States)

    Berdahl, C. M.

    1986-01-01

    New manufacturing process produces filters strong, yet have small, precise dimensions and smooth surface finish essential for dichroic filtering at submillimeter wavelengths. Many filters, each one essentially wafer containing fine metal grid made at same time. Stacked square wires plated, fused, and etched to form arrays of holes. Grid of nickel and tin held in brass ring. Wall thickness, thickness of filter (hole depth) and lateral hole dimensions all depend upon operating frequency and filter characteristics.

  14. Adaptive digital filters

    CERN Document Server

    Kovačević, Branko; Milosavljević, Milan

    2013-01-01

    “Adaptive Digital Filters” presents an important discipline applied to the domain of speech processing. The book first makes the reader acquainted with the basic terms of filtering and adaptive filtering, before introducing the field of advanced modern algorithms, some of which are contributed by the authors themselves. Working in the field of adaptive signal processing requires the use of complex mathematical tools. The book offers a detailed presentation of the mathematical models that is clear and consistent, an approach that allows everyone with a college level of mathematics knowledge to successfully follow the mathematical derivations and descriptions of algorithms.   The algorithms are presented in flow charts, which facilitates their practical implementation. The book presents many experimental results and treats the aspects of practical application of adaptive filtering in real systems, making it a valuable resource for both undergraduate and graduate students, and for all others interested in m...

  15. Stack filter classifiers

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Reid B [Los Alamos National Laboratory; Hush, Don [Los Alamos National Laboratory

    2009-01-01

    Just as linear models generalize the sample mean and weighted average, weighted order statistic models generalize the sample median and weighted median. This analogy can be continued informally to generalized additive modeels in the case of the mean, and Stack Filters in the case of the median. Both of these model classes have been extensively studied for signal and image processing but it is surprising to find that for pattern classification, their treatment has been significantly one sided. Generalized additive models are now a major tool in pattern classification and many different learning algorithms have been developed to fit model parameters to finite data. However Stack Filters remain largely confined to signal and image processing and learning algorithms for classification are yet to be seen. This paper is a step towards Stack Filter Classifiers and it shows that the approach is interesting from both a theoretical and a practical perspective.

  16. Automated electronic filter design

    CERN Document Server

    Banerjee, Amal

    2017-01-01

    This book describes a novel, efficient and powerful scheme for designing and evaluating the performance characteristics of any electronic filter designed with predefined specifications. The author explains techniques that enable readers to eliminate complicated manual, and thus error-prone and time-consuming, steps of traditional design techniques. The presentation includes demonstration of efficient automation, using an ANSI C language program, which accepts any filter design specification (e.g. Chebyschev low-pass filter, cut-off frequency, pass-band ripple etc.) as input and generates as output a SPICE(Simulation Program with Integrated Circuit Emphasis) format netlist. Readers then can use this netlist to run simulations with any version of the popular SPICE simulator, increasing accuracy of the final results, without violating any of the key principles of the traditional design scheme.

  17. A PC Controlled Filter

    Directory of Open Access Journals (Sweden)

    M. Van Looy

    1998-12-01

    Full Text Available In this paper we present a switched capacitor filter design using the SC22324 1C, which is fitted with an E2PROM. It contains four digitally programmable switched-capacitor filter sections, in order to obtain different responses. The SC22324 also contains the on-chip RAM. We'd like to explain, how could the on-chip RAM controlled via a PC. In this way the chip may be used afterwards with a menu where the user may select the wanted parameters.

  18. Parzen Particle Filters

    DEFF Research Database (Denmark)

    Lehn-Schiøler, Tue; Erdogmus, Deniz; Principe, Jose C.

    2004-01-01

    Using a Parzen density estimator any distribution can be approximated arbitrarily close by a sum of kernels. In particle filtering this fact is utilized to estimate a probability density function with Dirac delta kernels; when the distribution is discretized it becomes possible to solve an otherw......Using a Parzen density estimator any distribution can be approximated arbitrarily close by a sum of kernels. In particle filtering this fact is utilized to estimate a probability density function with Dirac delta kernels; when the distribution is discretized it becomes possible to solve...

  19. Space Launch System Base Heating Test: Sub-Scale Rocket Engine/Motor Design, Development & Performance Analysis

    Science.gov (United States)

    Mehta, Manish; Seaford, Mark; Kovarik, Brian; Dufrene, Aaron; Solly, Nathan

    2014-01-01

    ATA-002 Technical Team has successfully designed, developed, tested and assessed the SLS Pathfinder propulsion systems for the Main Base Heating Test Program. Major Outcomes of the Pathfinder Test Program: Reach 90% of full-scale chamber pressure Achieved all engine/motor design parameter requirements Reach steady plume flow behavior in less than 35 msec Steady chamber pressure for 60 to 100 msec during engine/motor operation Similar model engine/motor performance to full-scale SLS system Mitigated nozzle throat and combustor thermal erosion Test data shows good agreement with numerical prediction codes Next phase of the ATA-002 Test Program Design & development of the SLS OML for the Main Base Heating Test Tweak BSRM design to optimize performance Tweak CS-REM design to increase robustness MSFC Aerosciences and CUBRC have the capability to develop sub-scale propulsion systems to meet desired performance requirements for short-duration testing.

  20. Design and Analysis of Subscale and Full-Scale Buckling-Critical Cylinders for Launch Vehicle Technology Development

    Science.gov (United States)

    Hilburger, Mark W.; Lovejoy, Andrew E.; Thornburgh, Robert P.; Rankin, Charles

    2012-01-01

    NASA s Shell Buckling Knockdown Factor (SBKF) project has the goal of developing new analysis-based shell buckling design factors (knockdown factors) and design and analysis technologies for launch vehicle structures. Preliminary design studies indicate that implementation of these new knockdown factors can enable significant reductions in mass and mass-growth in these vehicles. However, in order to validate any new analysis-based design data or methods, a series of carefully designed and executed structural tests are required at both the subscale and full-scale levels. This paper describes the design and analysis of three different orthogrid-stiffeNed metallic cylindrical-shell test articles. Two of the test articles are 8-ft-diameter, 6-ft-long test articles, and one test article is a 27.5-ft-diameter, 20-ft-long Space Shuttle External Tank-derived test article.

  1. Diabetes fatalism and its emotional distress subscale are independent predictors of glycemic control among Lebanese patients with type 2 diabetes.

    Science.gov (United States)

    Sukkarieh-Haraty, Ola; Egede, Leonard E; Abi Kharma, Joelle; Bassil, Maya

    2017-09-04

    Achieving and sustaining optimal glycemic control in type 2 diabetes (T2DM) is difficult because of socio-cultural and psychosocial factors including diabetes fatalism. Diabetes fatalism is 'a complex psychological cycle characterized by perceptions of despair, hopelessness, and powerlessness'. The purpose of this paper is to explore whether diabetes fatalism and other psychosocial and socio-cultural variables are correlates of glycemic control in Lebanese population with T2DM. A convenience sample of 280 adult participants with T2DM were recruited from a major hospital in greater Beirut-Lebanon area and from the community. Diabetes fatalism was assessed using the Arabic version of 12-item Diabetes Fatalism Scale. Multiple linear regression models were used to assess the relationship between HbA1c and psychosocial and socio-cultural characteristics including diabetes fatalism. Four models were run to examine the independent association between HbA1c and diabetes fatalism and to identify which of the 3 subscales (emotional distress, spiritual coping and perceived self-efficacy) were associated with HbA1c. The mean age of the participants was 58.24(SD = 13.48) and the majority were females (53.76%), while 32.73% of the sample had diabetes for more than 10 years. Fully adjusted multiple linear regression models showed that higher scores on diabetes fatalism and the emotional distress subscale (P = 0.018) were significantly associated with higher HbA1c values. In addition, having diabetes for more than 11 years (P = 0.05) and a higher number of diabetes complications (P fatalism as an independent predictor of glycemic control among Lebanese. Future studies should further investigate this construct to guide interventions that can address it for better diabetes outcomes.

  2. DIGITAL FILTERS IMPLEMENTATION IN MICROPROCESSOR-BASED RELAY PROTECTION

    Directory of Open Access Journals (Sweden)

    Yu. V. Rumiantsev

    2016-01-01

    Full Text Available This article presents the implementation of digital filters used in digital relay protection current measuring elements. Mathematical descriptions of the considered digital filters as well as the computer programs for their coefficients calculation are described. It has been shown that in order to reliable estimate the digital filter performance its input signals waveforms must be close to the actual secondary current waveform of the current transformer to which the digital protection with the estimated digital filter is connected. For these purposes in MatLab–Simulink dynamic simulation environment the power system and the current measuring element models were developed. Performed calculations allowed to reveal that the exponentially decaying DC component which in some cases contains in primary fault current drives the current transformer core into saturation even when its nominal parameters are not exceeded. This results in distortion of the current transformer secondary current which in this case contains higher and inter-harmonics. Moreover, such harmonic content is not completely taking into account during coefficients calculation of the considered digital filters what results in signal magnitude estimation inaccuracy. Comparison of the digital filters response to the above-mentioned input signals allowed to find out such digital filter implementations which enable signal magnitude estimation with a minimum error. Ways of filtering quality improvement concerned with the window functions are proposed. Thus, the joint usage of digital filter and Hamming window allows to achieve the zero value of the signal magnitude gain factor in high-frequency range and substantially suppress all spectral components above 100 Hz. The increasing of the signal magnitude settling time in this case can be reduced by choosing the most optimal parameters of the all components of the current measuring element.

  3. The concurrent validity of the Problem Oriented Screening Instrument for Teenagers (POSIT) substance use/abuse subscale in adolescent patients in an urban federally qualified health center.

    Science.gov (United States)

    Kelly, Sharon M; O'Grady, Kevin E; Gryczynski, Jan; Mitchell, Shannon Gwin; Kirk, Arethusa; Schwartz, Robert P

    2017-01-01

    The Problem Oriented Screening Instrument for Teenagers (POSIT) substance use/abuse subscale has been validated with high school students, adolescents with criminal justice involvement, and adolescent substance use treatment samples using the Diagnostic and Statistical Manual of Mental Disorders (DSM)-III-R and DSM-IV. This study examines the concurrent validity of the POSIT's standard 17-item substance use/abuse subscale and a revised, shorter 11-item version using DSM-5 substance use disorder diagnoses. Adolescents (N = 525; 93% African American, 55% female) 12-17 years of age awaiting primary care appointments at a Federally Qualified Health Center in Baltimore, Maryland completed the 17-item POSIT substance use/abuse subscale and items from a modified World Mental Health Composite International Diagnostic Interview corresponding to DSM-5 alcohol use disorder (AUD) and cannabis use disorder (CUD). Receiver operating characteristic curves, sensitivities, and specificities were examined with DSM-5 AUD, CUD, and a diagnosis of either or both disorders for the standard and revised subscales using risk cutoffs of either 1 or 2 POSIT "yes" responses. For the 17-item subscale, sensitivities were generally high using either cutoff (range: 0.79-1.00), although a cutoff of 1 was superior (sensitivities were 1.00 for AUD, CUD, and for either disorder). Specificities were also high using either cutoff (range: 0.81-0.95) but were higher using a cutoff of 2. For the 11-item subscale, a cutoff of 1 yielded higher sensitivities than a cutoff of 2 (ranges for 1 and 2: 0.96-1.00 and 0.79-0.86, respectively). Specificities for this subscale were higher using a cutoff of 2 (ranges for 1 and 2: 0.82-0.89 and 0.89-0.96, respectively). Findings suggest that the POSIT's substance use/abuse subscale is a potentially useful tool for screening adolescents in primary care for AUD or CUD using a cutoff of 1 or 2. The briefer, revised subscale may be preferable to the standard subscale in

  4. Enhanced Optical Filter Design

    CERN Document Server

    Cushing, David

    2011-01-01

    This book serves as a supplement to the classic texts by Angus Macleod and Philip Baumeister, taking an intuitive approach to the enhancement of optical coating (or filter) performance. Drawing from 40 years of experience in thin film design, Cushing introduces the basics of thin films, the commonly used materials and their deposition, the major coatings and their applications, and improvement methods for each.

  5. The ATLAS event filter

    CERN Document Server

    Beck, H P; Boissat, C; Davis, R; Duval, P Y; Etienne, F; Fede, E; Francis, D; Green, P; Hemmer, F; Jones, R; MacKinnon, J; Mapelli, Livio P; Meessen, C; Mommsen, R K; Mornacchi, Giuseppe; Nacasch, R; Negri, A; Pinfold, James L; Polesello, G; Qian, Z; Rafflin, C; Scannicchio, D A; Stanescu, C; Touchard, F; Vercesi, V

    1999-01-01

    An overview of the studies for the ATLAS Event Filter is given. The architecture and the high level design of the DAQ-1 prototype is presented. The current status if the prototypes is briefly given. Finally, future plans and milestones are given. (11 refs).

  6. Sand Filter Technology

    Science.gov (United States)

    2016-08-01

    EXWC) performed the evaluation at the Naval Air Station Lemoore, CA . The two year evaluation period began with one year of sand filter operation...appear dirty? If you answered “ yes ” to the first question and “ yes ” to either of the other questions, investigate this technology for your

  7. Fast Anisotropic Gauss Filters

    NARCIS (Netherlands)

    Geusebroek, J.M.; Smeulders, A.W.M.; van de Weijer, J.

    2003-01-01

    We derive the decomposition of the anisotropic Gaussian in a one dimensional Gauss filter in the x-direction phi. So also the anisotropic Gaussian can be decomposed by dimension. This appears to be extremely efficient from a computing perspective. An implementation scheme for normal covolution and

  8. Ceramic HEPA Filter Program

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, M A; Bergman, W; Haslam, J; Brown, E P; Sawyer, S; Beaulieu, R; Althouse, P; Meike, A

    2012-04-30

    Potential benefits of ceramic filters in nuclear facilities: (1) Short term benefit for DOE, NRC, and industry - (a) CalPoly HTTU provides unique testing capability to answer questions for DOE - High temperature testing of materials, components, filter, (b) Several DNFSB correspondences and presentations by DNFSB members have highlighted the need for HEPA filter R and D - DNFSB Recommendation 2009-2 highlighted a nuclear facility response to an evaluation basis earthquake followed by a fire (aka shake-n-bake) and CalPoly has capability for a shake-n-bake test; (2) Intermediate term benefit for DOE and industry - (a) Filtration for specialty applications, e.g., explosive applications at Nevada, (b) Spin-off technologies applicable to other commercial industries; and (3) Long term benefit for DOE, NRC, and industry - (a) Across industry, strong desire for better performance filter, (b) Engineering solution to safety problem will improve facility safety and decrease dependence on associated support systems, (c) Large potential life-cycle cost savings, and (d) Facilitates development and deployment of LLNL process innovations to allow continuous ventilation system operation during a fire.

  9. Underwater Sound Filtering

    NARCIS (Netherlands)

    Rutger van Aalst; Ines Simic

    2015-01-01

    This paper describes a possible solution to the underwater sound filtering problem, using Blind Source Separation. The problem regards splitting sound from a boat engine and the water waves to prove the possibility to extract one sound fragment from the other on the open sea. The illustrations shown

  10. MOS switched-capacitor filters using voltage inverter switches

    Science.gov (United States)

    Fettweis, A.; Pandel, J.; Herbst, D.; Hoefflinger, B.; Schweer, R.

    1980-06-01

    The paper examines MOS switched-capacitor filters which use voltage inverter switches. Low-sensitivity switched-capacitor filters imitating LC and LC/unit-element structures can be built by means of capacitances, ordinary switches, and voltage inverter switches; the latter are simply realizable by electronic means. It was found that there are no restrictions on the operating rate (other than those resulting from the Nyquist theorem), or on the location of the attenuation poles; it was also found that the effects of parasitic capacitances can be overcome by proper design techniques. The experimental results of an integrated third-order low-pass filter are in agreement with theory.

  11. Design and development of high performance panel air filter with experimental evaluation and analysis of filter media pleats

    Directory of Open Access Journals (Sweden)

    Sagar R. Patil

    2015-11-01

    Full Text Available In automobile vehicles mostly plastic molded panel filters used for the purpose of engine air filtration. Fibrous structured cellulose media were being used with different permeability’s according to requirement of rated air flow rate required for the engine. To optimize the filter pleat design of automotive panel air filter, it is important to study correlation of pressure drop, dust holding capacity & efficiency. The main role of a filter is to provide least pressure drop with high dust holding and efficiency. A channel made for the testing of different pleat designs. This research comprises of experimental design & evaluation of filter element with variable pleat depth and pleat density. This assessment offers the selection of pleat design according to the performance requirements.

  12. DEMONSTRATION BULLETIN: COLLOID POLISHING FILTER METHOD - FILTER FLOW TECHNOLOGY, INC.

    Science.gov (United States)

    The Filter Flow Technology, Inc. (FFT) Colloid Polishing Filter Method (CPFM) was tested as a transportable, trailer mounted, system that uses sorption and chemical complexing phenomena to remove heavy metals and nontritium radionuclides from water. Contaminated waters can be pro...

  13. Numerical study of canister filters with alternatives filter cap configurations

    Science.gov (United States)

    Mohammed, A. N.; Daud, A. R.; Abdullah, K.; Seri, S. M.; Razali, M. A.; Hushim, M. F.; Khalid, A.

    2017-09-01

    Air filtration system and filter play an important role in getting a good quality air into turbo machinery such as gas turbine. The filtration system and filter has improved the quality of air and protect the gas turbine part from contaminants which could bring damage. During separation of contaminants from the air, pressure drop cannot be avoided but it can be minimized thus helps to reduce the intake losses of the engine [1]. This study is focused on the configuration of the filter in order to obtain the minimal pressure drop along the filter. The configuration used is the basic filter geometry provided by Salutary Avenue Manufacturing Sdn Bhd. and two modified canister filter cap which is designed based on the basic filter model. The geometries of the filter are generated by using SOLIDWORKS software and Computational Fluid Dynamics (CFD) software is used to analyse and simulates the flow through the filter. In this study, the parameters of the inlet velocity are 0.032 m/s, 0.063 m/s, 0.094 m/s and 0.126 m/s. The total pressure drop produce by basic, modified filter 1 and 2 is 292.3 Pa, 251.11 Pa and 274.7 Pa. The pressure drop reduction for the modified filter 1 is 41.19 Pa and 14.1% lower compared to basic filter and the pressure drop reduction for modified filter 2 is 17.6 Pa and 6.02% lower compared to the basic filter. The pressure drops for the basic filter are slightly different with the Salutary Avenue filter due to limited data and experiment details. CFD software are very reliable in running a simulation rather than produces the prototypes and conduct the experiment thus reducing overall time and cost in this study.

  14. FPGA implementation of filtered image using 2D Gaussian filter

    OpenAIRE

    Leila kabbai; Anissa Sghaier; Ali Douik; Mohsen Machhout

    2016-01-01

    Image filtering is one of the very useful techniques in image processing and computer vision. It is used to eliminate useless details and noise from an image. In this paper, a hardware implementation of image filtered using 2D Gaussian Filter will be present. The Gaussian filter architecture will be described using a different way to implement convolution module. Thus, multiplication is in the heart of convolution module, for this reason, three different ways to implement multiplication opera...

  15. Generalized Selection Weighted Vector Filters

    Directory of Open Access Journals (Sweden)

    Rastislav Lukac

    2004-09-01

    Full Text Available This paper introduces a class of nonlinear multichannel filters capable of removing impulsive noise in color images. The here-proposed generalized selection weighted vector filter class constitutes a powerful filtering framework for multichannel signal processing. Previously defined multichannel filters such as vector median filter, basic vector directional filter, directional-distance filter, weighted vector median filters, and weighted vector directional filters are treated from a global viewpoint using the proposed framework. Robust order-statistic concepts and increased degree of freedom in filter design make the proposed method attractive for a variety of applications. Introduced multichannel sigmoidal adaptation of the filter parameters and its modifications allow to accommodate the filter parameters to varying signal and noise statistics. Simulation studies reported in this paper indicate that the proposed filter class is computationally attractive, yields excellent performance, and is able to preserve fine details and color information while efficiently suppressing impulsive noise. This paper is an extended version of the paper by Lukac et al. presented at the 2003 IEEE-EURASIP Workshop on Nonlinear Signal and Image Processing (NSIP '03 in Grado, Italy.

  16. Scientific Bases of Innovation Technology of Drill-Hole Equipment by Cryogenic-Gravel Filters

    Directory of Open Access Journals (Sweden)

    Коzhevnikov, А.А.

    2015-05-01

    Full Text Available Manufacturing technologies of cryogenic-gravel filter element and equipment of drill-hole water receiving part by a cryogenic-gravel filter are described. Compoundings of mineral binder and cryogenically-gravel composition are substantiated. Patterns of physical fields influence on the change of their properties and technological operations of equipping drill-hole water receiving part on changes of physical, mechanical, thermal and technological properties of experimental cryogenic gravel filter element are established. Parameters of delivery technology of cryogenicgravel filter to drill-hole water receiving part are theoretically and experimentally worked out.

  17. Distance Sensitive Bloom Filters Without False Negatives

    DEFF Research Database (Denmark)

    Goswami, Mayank; Pagh, Rasmus; Silvestri, Francesco

    2017-01-01

    A Bloom filter is a widely used data-structure for representing a set S and answering queries of the form “Is x in S?”. By allowing some false positive answers (saying ‘yes’ when the answer is in fact ‘no’) Bloom filters use space significantly below what is required for storing S. In the distance...... sensitive setting we work with a set S of (Hamming) vectors and seek a data structure that offers a similar trade-off, but answers queries of the form “Is x close to an element of S?” (in Hamming distance). Previous work on distance sensitive Bloom filters have accepted false positive and false negative...... answers. Absence of false negatives is of critical importance in many applications of Bloom filters, so it is natural to ask if this can be also achieved in the distance sensitive setting. Our main contributions are upper and lower bounds (that are tight in several cases) for space usage in the distance...

  18. Microbinary element for optical wavelet transform

    Science.gov (United States)

    Huang, Gaogui; Feng, Wenyi; Yan, Yingbai; Jin, Guofan

    1997-09-01

    In order to simplify an opto-electronic hybrid system for texture segmentation based on the multi-channel filtering framework in the human visual theory, a micro-binary optical element (BOE) is designed and fabricated. The BOE has the functions of splitting, filtering and imaging simultaneously. The focal length of the BOE is 150mm and the diameter is 4mm. It contains sixteen Gabor wavelet filters with scales decreased by 2 orders and with our orientations separated every 45 degree, which can be used to perform a nearly complete decomposition with wavelet transform. The relief surface structure with minimum feature scale of 1.5micrometers is fabricated by using the photolithography and ion etching technique. In this paper, the functions of the BOE and the simulation of the filtering are described in detail, the experimental results and improvement of the element are given.

  19. Hydrodynamics of microbial filter feeding

    DEFF Research Database (Denmark)

    Nielsen, Lasse Tor; Asadzadeh, Seyed Saeed; Dölger, Julia

    2017-01-01

    Microbial filter feeders are an important group of grazers, significant to the microbial loop, aquatic food webs, and biogeochemical cycling. Our understanding of microbial filter feeding is poor, and, importantly, it is unknown what force microbial filter feeders must generate to process adequate...... amounts of water. Also, the trade-off in the filter spacing remains unexplored, despite its simple formulation: A filter too coarse will allow suitably sized prey to pass unintercepted, whereas a filter too fine will cause strong flow resistance. We quantify the feeding flow of the filter......-feeding choanoflagellate Diaphanoeca grandis using particle tracking, and demonstrate that the current understanding of microbial filter feeding is inconsistent with computational fluid dynamics (CFD) and analytical estimates. Both approaches underestimate observed filtration rates by more than an order of magnitude...

  20. Analog filters in nanometer CMOS

    CERN Document Server

    Uhrmann, Heimo; Zimmermann, Horst

    2014-01-01

    Starting from the basics of analog filters and the poor transistor characteristics in nanometer CMOS 10 high-performance analog filters developed by the authors in 120 nm and 65 nm CMOS are described extensively. Among them are gm-C filters, current-mode filters, and active filters for system-on-chip realization for Bluetooth, WCDMA, UWB, DVB-H, and LTE applications. For the active filters several operational amplifier designs are described. The book, furthermore, contains a review of the newest state of research on low-voltage low-power analog filters. To cover the topic of the book comprehensively, linearization issues and measurement methods for the characterization of advanced analog filters are introduced in addition. Numerous elaborate illustrations promote an easy comprehension. This book will be of value to engineers and researchers in industry as well as scientists and Ph.D students at universities. The book is also recommendable to graduate students specializing on nanoelectronics, microelectronics ...

  1. Development of Test Protocols for International Space Station Particulate Filters

    Science.gov (United States)

    Green, Robert D.; Vijayakumar, R.; Agui, Juan H.

    2014-01-01

    Air quality control on the International Space Station (ISS) is a vital requirement for maintaining a clean environment for the crew and the hardware. This becomes a serious challenge in pressurized space compartments since no outside air ventilation is possible, and a larger particulate load is imposed on the filtration system due to lack of gravitational settling. The ISS Environmental Control and Life Support System (ECLSS) uses a filtration system that has been in use for over 14 years and has proven to meet this challenge. The heart of this system is a traditional High- Efficiency Particulate Air (HEPA) filter configured to interface with the rest of the life support elements and provide effective cabin filtration. Over the years, the service life of these filters has been re-evaluated based on limited post-flight tests of returned filters and risk factors. On earth, a well designed and installed HEPA filter will last for several years, e.g. in industrial and research clean room applications. Test methods for evaluating these filters are being developed on the basis of established test protocols used by the industry and the military. This paper will discuss the test methods adopted and test results on prototypes of the ISS filters. The results will assist in establishing whether the service life can be extended for these filters. Results from unused filters that have been in storage will also be presented to ascertain the shelf life and performance deterioration, if any and determine if the shelf life may be extended.

  2. Confirmatory Factor Analysis and Multiple Linear Regression of the Neck Disability Index: Assessment If Subscales Are Equally Relevant in Whiplash and Nonspecific Neck Pain.

    Science.gov (United States)

    Croft, Arthur C; Milam, Bryce; Meylor, Jade; Manning, Richard

    2016-06-01

    Because of previously published recommendations to modify the Neck Disability Index (NDI), we evaluated the responsiveness and dimensionality of the NDI within a population of adult whiplash-injured subjects. The purpose of the present study was to evaluate the responsiveness and dimensionality of the NDI within a population of adult whiplash-injured subjects. Subjects who had sustained whiplash injuries of grade 2 or higher completed an NDI questionnaire. There were 123 subjects (55% female, of which 36% had recovered and 64% had chronic symptoms. NDI subscales were analyzed using confirmatory factor analysis, considering only the subscales and, secondly, using sex as an 11th variable. The subscales were also tested with multiple linear regression modeling using the total score as a target variable. When considering only the 10 NDI subscales, only a single factor emerged, with an eigenvalue of 5.4, explaining 53.7% of the total variance. Strong correlation (> .55) (P Multiple linear regression modeling revealed high internal consistency with all coefficients reaching significance (P < .0001). The 4 NDI subscales exerting the greatest effect were, in decreasing order, Sleeping, Lifting, Headaches, and Pain Intensity. A 2-factor model of the NDI is not justified based on our results, and in this population of whiplash subjects, the NDI was unidimensional, demonstrating high internal consistency and supporting the original validation study of Vernon and Mior.

  3. Comparison of Deconvolution Filters for Photoacoustic Tomography.

    Directory of Open Access Journals (Sweden)

    Dominique Van de Sompel

    Full Text Available In this work, we compare the merits of three temporal data deconvolution methods for use in the filtered backprojection algorithm for photoacoustic tomography (PAT. We evaluate the standard Fourier division technique, the Wiener deconvolution filter, and a Tikhonov L-2 norm regularized matrix inversion method. Our experiments were carried out on subjects of various appearances, namely a pencil lead, two man-made phantoms, an in vivo subcutaneous mouse tumor model, and a perfused and excised mouse brain. All subjects were scanned using an imaging system with a rotatable hemispherical bowl, into which 128 ultrasound transducer elements were embedded in a spiral pattern. We characterized the frequency response of each deconvolution method, compared the final image quality achieved by each deconvolution technique, and evaluated each method's robustness to noise. The frequency response was quantified by measuring the accuracy with which each filter recovered the ideal flat frequency spectrum of an experimentally measured impulse response. Image quality under the various scenarios was quantified by computing noise versus resolution curves for a point source phantom, as well as the full width at half maximum (FWHM and contrast-to-noise ratio (CNR of selected image features such as dots and linear structures in additional imaging subjects. It was found that the Tikhonov filter yielded the most accurate balance of lower and higher frequency content (as measured by comparing the spectra of deconvolved impulse response signals to the ideal flat frequency spectrum, achieved a competitive image resolution and contrast-to-noise ratio, and yielded the greatest robustness to noise. While the Wiener filter achieved a similar image resolution, it tended to underrepresent the lower frequency content of the deconvolved signals, and hence of the reconstructed images after backprojection. In addition, its robustness to noise was poorer than that of the Tikhonov

  4. The Rao-Blackwellized Particle Filter: A Filter Bank Implementation

    Directory of Open Access Journals (Sweden)

    Karlsson Rickard

    2010-01-01

    Full Text Available For computational efficiency, it is important to utilize model structure in particle filtering. One of the most important cases occurs when there exists a linear Gaussian substructure, which can be efficiently handled by Kalman filters. This is the standard formulation of the Rao-Blackwellized particle filter (RBPF. This contribution suggests an alternative formulation of this well-known result that facilitates reuse of standard filtering components and which is also suitable for object-oriented programming. Our RBPF formulation can be seen as a Kalman filter bank with stochastic branching and pruning.

  5. Multilevel particle filter

    KAUST Repository

    Law, Kody

    2016-01-06

    This talk will pertain to the filtering of partially observed diffusions, with discrete-time observations. It is assumed that only biased approximations of the diffusion can be obtained, for choice of an accuracy parameter indexed by l. A multilevel estimator is proposed, consisting of a telescopic sum of increment estimators associated to the successive levels. The work associated to O( 2) mean-square error between the multilevel estimator and average with respect to the filtering distribution is shown to scale optimally, for example as O( 2) for optimal rates of convergence of the underlying diffusion approximation. The method is illustrated on some toy examples as well as estimation of interest rate based on real S&P 500 stock price data.

  6. Particle flow superpositional GLMB filter

    Science.gov (United States)

    Saucan, Augustin-Alexandru; Li, Yunpeng; Coates, Mark

    2017-05-01

    In this paper we propose a Superpositional Marginalized δ-GLMB (SMδ-GLMB) filter for multi-target tracking and we provide bootstrap and particle flow particle filter implementations. Particle filter implementations of the marginalized δ-GLMB filter are computationally demanding. As a first contribution we show that for the specific case of superpositional observation models, a reduced complexity update step can be achieved by employing a superpositional change of variables. The resulting SMδ-GLMB filter can be readily implemented using the unscented Kalman filter or particle filtering methods. As a second contribution, we employ particle flow to produce a measurement-driven importance distribution that serves as a proposal in the SMδ-GLMB particle filter. In high-dimensional state systems or for highly- informative observations the generic particle filter often suffers from weight degeneracy or otherwise requires a prohibitively large number of particles. Particle flow avoids particle weight degeneracy by guiding particles to regions where the posterior is significant. Numerical simulations showcase the reduced complexity and improved performance of the bootstrap SMδ-GLMB filter with respect to the bootstrap Mδ-GLMB filter. The particle flow SMδ-GLMB filter further improves the accuracy of track estimates for highly informative measurements.

  7. Manipulation Robustness of Collaborative Filtering

    OpenAIRE

    Benjamin Van Roy; Xiang Yan

    2010-01-01

    A collaborative filtering system recommends to users products that similar users like. Collaborative filtering systems influence purchase decisions and hence have become targets of manipulation by unscrupulous vendors. We demonstrate that nearest neighbors algorithms, which are widely used in commercial systems, are highly susceptible to manipulation and introduce new collaborative filtering algorithms that are relatively robust.

  8. Popping the filter bubble

    OpenAIRE

    Hughes, Katie; Cronin, G; Welch, L

    2017-01-01

    So-called “fake news” is everywhere and is having a major impact on daily life from politics to education. The rapid growth of information and the numbers of people who can create it means that we need more sophisticated tools to process the news we receive. Join us to learn about different methods you can use to be your own fact checker and pop your filter bubble.

  9. Offsetting the Affective Filter

    Directory of Open Access Journals (Sweden)

    Barry Chametzky, PhD

    2017-06-01

    Full Text Available When forced to deal with a stressful, unfamiliar situation, how do people react? People are familiar, in a traditional setting, with sensory overload. But in an online environment, when learners are anxious, they exhibit different behaviors to help mediate their anxiety. Additionally, in an online environment, since visual clues are often lacking, how do these behaviors manifest themselves? People navigate stressful and/or unfamiliar situations by offsetting their affective filter.

  10. Filter Bank Fusion Frames

    OpenAIRE

    Chebira, Amina; Fickus, Matthew; Mixon, Dustin G.

    2010-01-01

    In this paper we characterize and construct novel oversampled filter banks implementing fusion frames. A fusion frame is a sequence of orthogonal projection operators whose sum can be inverted in a numerically stable way. When properly designed, fusion frames can provide redundant encodings of signals which are optimally robust against certain types of noise and erasures. However, up to this point, few implementable constructions of such frames were known; we show how to construct them using ...

  11. Mechanical design and qualification of IR filter mounts and filter wheel of INSAT-3D sounder for low temperature

    Science.gov (United States)

    Vora, A. P.; Rami, J. B.; Hait, A. K.; Dewan, C. P.; Subrahmanyam, D.; Kirankumar, A. S.

    2017-11-01

    Next generation Indian Meteorological Satellite will carry Sounder instrument having subsystem of filter wheel measuring Ø260mm and carrying 18 filters arranged in three concentric rings. These filters made from Germanium, are used to separate spectral channels in IR band. Filter wheel is required to be cooled to 214K and rotated at 600 rpm. This Paper discusses the challenges faced in mechanical design of the filter wheel, mainly filter mount design to protect brittle germanium filters from failure under stresses due to very low temperature, compactness of the wheel and casings for improved thermal efficiency, survival under vibration loads and material selection to keep it lighter in weight. Properties of Titanium, Kovar, Invar and Aluminium materials are considered for design. The mount has been designed to accommodate both thermal and dynamic loadings without introducing significant aberrations into the optics or incurring permanent alignment shifts. Detailed finite element analysis of mounts was carried out for stress verification. Results of the qualification tests are discussed for given temperature range of 100K and vibration loads of 12g in Sine and 11.8grms in Random at mount level. Results of the filter wheel qualification as mounted in Electro Optics Module (EOM) are also presented.

  12. Wide-Stopband Aperiodic Phononic Filters

    Science.gov (United States)

    Rostem, Karwan; Chuss, David; Denis, K. L.; Wollack, E. J.

    2016-01-01

    We demonstrate that a phonon stopband can be synthesized from an aperiodic structure comprising a discrete set of phononic filter stages. Each element of the set has a dispersion relation that defines a complete bandgap when calculated under a Bloch boundary condition. Hence, the effective stopband width in an aperiodic phononic filter (PnF) may readily exceed that of a phononic crystal with a single lattice constant or a coherence scale. With simulations of multi-moded phononic waveguides, we discuss the effects of finite geometry and mode-converting junctions on the phonon transmission in PnFs. The principles described may be utilized to form a wide stopband in acoustic and surface wave media. Relative to the quantum of thermal conductance for a uniform mesoscopic beam, a PnF with a stopband covering 1.6-10.4 GHz is estimated to reduce the thermal conductance by an order of magnitude at 75 mK.

  13. Clinical utility of the MMPI-A content scales and Harris-Lingoes subscales in the assessment of suicidal risk factors in psychiatric adolescents.

    Science.gov (United States)

    Kopper, B A; Osman, A; Osman, J R; Hoffman, J

    1998-02-01

    This study of 143 inpatient adolescents (68 boys and 75 girls) investigated the clinical utility of the MMPI-A in assessing suicidal risk factors by examining the unique contribution of the content scales and Harris-Lingoes subscales beyond what is provided by the basic clinical scales. The results of the regression analyses indicated that for boys, the Depression, Psychopathic Deviate and Hypomania scales; Alienation and Anxiety content scales: and Subjective Depression. Self Alienation, Imperturbability, and Amorality Harris-Lingoes subscales contributed significantly to the prediction of suicide probability. For girls, the Depression, Psychopathic Deviate, and Hypomania scales; Family Problems, Conduct Problems, School Problems, Depression, and Social Discomfort content scales; and the Subjective Depression, Self Alienation, Psychomotor Acceleration, and Imperturbability Harris-Lingoes subscales contributed significantly to the prediction of suicide probability.

  14. Chilean experimental version of the State-Trait Depression Questionnaire (ST-DEP: Trait sub-scale (T-DEP

    Directory of Open Access Journals (Sweden)

    Pablo Vera-Villarroel

    2008-01-01

    Full Text Available This instrumental study presents the first validity and reliability data for the Trait subscale (T-DEP of the Chilean experimental version of the State and Trait Depression Inventory (ST-DEP: Euthymia and Dysthymia. The data were obtained from a sample of 300 university students. The internal consistency values for the TDEP were high (.90. The test-retest values from eight weeks time interval (fifty six days were elevated (.78. A factorial analysis of the principal components revealed a principal factor for all of the constructed items in this experimental version of the TDEP. The last, promax rotation showed two clear main factors similar in size: negative affectivity (Dysthymia and positive affectivity (Euthymia. The convergent validity indexes for the Beck Depression Inventory and the Zung Self Rating Depression Scale, were also high, with indexes ranging from .64 to .71. The correlation between State- Trait Anxiety Inventory and the depression scales used in this study was high (between .63 and .78, once again indicating the usual overlapping between anxiety and depression seen in most depression inventories.

  15. The X-40 sub-scale technology demonstrator and its U.S. Army CH-47 Chinook helicopter mothership fly

    Science.gov (United States)

    2000-01-01

    The X-40 sub-scale technology demonstrator and its U.S. Army CH-47 Chinook helicopter mothership fly over a dry lakebed runway during a captive-carry test flight from NASA's Dryden Flight Research Center, Edwards, California. The X-40 is attached to a sling which is suspended from the CH-47 by a 110-foot-long cable during the tests, while a small parachute trails behind to provide stability. The captive carry flights are designed to verify the X-40's navigation and control systems, rigging angles for its sling, and stability and control of the helicopter while carrying the X-40 on a tether. Following a series of captive-carry flights, the X-40 made free flights from a launch altitude of about 15,000 feet above ground, gliding to a fully autonomous landing. The X-40 is an unpowered 82 percent scale version of the X-37, a Boeing-developed spaceplane designed to demonstrate various advanced technologies for development of future lower-cost access to space vehicles. The X-37 will be carried into space aboard a space shuttle and then released to perform various maneuvers and a controlled re-entry through the Earth's atmosphere to an airplane-style landing on a runway, controlled entirely by pre-programmed computer software.

  16. Development of a sub-scale dynamics model for pressure relaxation of multi-material cells in Lagrangian hydrodynamics

    Directory of Open Access Journals (Sweden)

    Canfield T.R.

    2011-01-01

    Full Text Available We have extended the Sub-Scale Dynamics (SSD closure model for multi-fluid computational cells. Volume exchange between two materials is based on the interface area and a notional interface translation velocity, which is derived from a linearized Riemann solution. We have extended the model to cells with any number of materials, computing pressure-difference-driven volume and energy exchange as the algebraic sum of pairwise interactions. In multiple dimensions, we rely on interface reconstruction to provide interface areas and orientations, and centroids of material polygons. In order to prevent unphysically large or unmanageably small material volumes, we have used a flux-corrected transport (FCT approach to limit the pressure-driven part of the volume exchange. We describe the implementation of this model in two dimensions in the FLAG hydrodynamics code. We also report on Lagrangian test calculations, comparing them with others made using a mixed-zone closure model due to Tipton, and with corresponding calculations made with only single-material cells. We find that in some cases, the SSD model more accurately predicts the state of material in mixed cells. By comparing the algebraic forms of both models, we identify similar dependencies on state and dynamical variables, and propose explanations for the apparent higher fidelity of the SSD model.

  17. Comparative Responsiveness of the PROMIS Pain Interference Short Forms, Brief Pain Inventory, PEG, and SF-36 Bodily Pain Subscale.

    Science.gov (United States)

    Kean, Jacob; Monahan, Patrick O; Kroenke, Kurt; Wu, Jingwei; Yu, Zhangsheng; Stump, Tim E; Krebs, Erin E

    2016-04-01

    To compare the sensitivity to change and the responsiveness to intervention of the PROMIS Pain Interference short forms, Brief Pain Inventory (BPI), 3-item PEG scale, and SF-36 Bodily Pain subscale in a sample of patients with persistent musculoskeletal pain of moderate severity. Standardized response means, standardized effect sizes, and receiver operating curve analyses were used to assess change between baseline and 3-month assessments in 250 participants who participated in a randomized clinical effectiveness trial of collaborative telecare management for moderate to severe and persistent musculoskeletal pain. The BPI, PEG, and SF-36 Bodily Pain measures were more sensitive to patient-reported global change than the PROMIS Pain Interference short forms, especially for the clinically improved group, for which the change detected by the PROMIS short forms was not statistically significant. The BPI was more responsive to the clinical intervention than the SF-36 Bodily Pain and PROMIS Pain Interference measures. Post hoc analyses exploring these findings did not suggest that differences in content or rating scale structure (number of response options or anchoring language) adequately explained the observed differences in the detection of change. In this clinical trial, the BPI and PEG measures were better able to detect change than the SF-36 Bodily Pain and PROMIS Pain Interference measures.

  18. Psychometric properties of the existence subscale of the purpose in life questionnaire for Chinese adolescents in Hong Kong.

    Science.gov (United States)

    Law, Ben M F

    2012-01-01

    The current study aims to test the psychometric properties of the Existence Subscale of the Purpose in Life Questionnaire (EPIL) for early adolescence. The Purpose in Life Questionnaire (PIL), originally created by Craumbaugh and Maholick, is a 20-item scale measuring different dimensions of life purposes. The current study selected seven items representative of the existence dimension to form another scale, the EPIL. The analysis was based on 2842 early adolescents, ranging from 11 to 14 years old. Principal axis factoring found one factor, with 60% variance being explained. Cronbach's alpha for the EPIL was 0.89, which was high. The factor structure was stable across genders. Criterion-related validity was determined when the scale was used to differentiate volunteers and nonvolunteers. Construct validity was found when the scale was associated with life satisfaction. The results give support to the fact that the EPIL could be used alone to measure the psychological well-being of early adolescents and the appropriateness of the EPIL in adolescent research.

  19. Analysis of the laser ignition of methane/oxygen mixtures in a sub-scale rocket combustion chamber

    Science.gov (United States)

    Wohlhüter, Michael; Zhukov, Victor P.; Sender, Joachim; Schlechtriem, Stefan

    2017-06-01

    The laser ignition of methane/oxygen mixtures in a sub-scale rocket combustion chamber has been investigated numerically and experimentally. The ignition test case used in the present paper was generated during the In-Space Propulsion project (ISP-1), a project focused on the operation of propulsion systems in space, the handling of long idle periods between operations, and multiple reignitions under space conditions. Regarding the definition of the numerical simulation and the suitable domain for the current model, 2D and 3D simulations have been performed. Analysis shows that the usage of a 2D geometry is not suitable for this type of simulation, as the reduction of the geometry to a 2D domain significantly changes the conditions at the time of ignition and subsequently the flame development. The comparison of the numerical and experimental results shows a strong discrepancy in the pressure evolution and the combustion chamber pressure peak following the laser spark. The detailed analysis of the optical Schlieren and OH data leads to the conclusion that the pressure measurement system was not able to capture the strong pressure increase and the peak value in the combustion chamber during ignition. Although the timing in flame development following the laser spark is not captured appropriately, the 3D simulations reproduce the general ignition phenomena observed in the optical measurement systems, such as pressure evolution and injector flow characteristics.

  20. Development of a sub-scale dynamics model for pressure relaxation of multi-material cells in Lagrangian hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, Alan K [Los Alamos National Laboratory; Shashkov, Mikhail J [Los Alamos National Laboratory; Fung, Jimmy [Los Alamos National Laboratory; Canfield, Thomas R [Los Alamos National Laboratory; Kamm, James R [SNLA

    2010-10-14

    We have extended the Sub-Scale Dynamics (SSD) closure model for multi-fluid computational cells. Volume exchange between two materials is based on the interface area and a notional interface translation velocity, which is derived from a linearized Riemann solution. We have extended the model to cells with any number of materials, computing pressure-difference-driven volume and energy exchange as the algebraic sum of pairwise interactions. In multiple dimensions, we rely on interface reconstruction to provide interface areas and orientations, and centroids of material polygons. In order to prevent unphysically large or unmanageably small material volumes, we have used a flux-corrected transport (FCT) approach to limit the pressure-driven part of the volume exchange. We describe the implementation of this model in two dimensions in the FLAG hydrodynamics code. We also report on Lagrangian test calculations, comparing them with others made using a mixed-zone closure model due to Tipton, and with corresponding calculations made with only single-material cells. We find that in some cases, the SSD model more accurately predicts the state of material in mixed cells. By comparing the algebraic forms of both models, we identify similar dependencies on state and dynamical variables, and propose explanations for the apparent higher fidelity of the SSD model.

  1. Differential Item Functioning in the SF-36 Physical Functioning and Mental Health Sub-Scales: A Population-Based Investigation in the Canadian Multicentre Osteoporosis Study.

    Science.gov (United States)

    Lix, Lisa M; Wu, Xiuyun; Hopman, Wilma; Mayo, Nancy; Sajobi, Tolulope T; Liu, Juxin; Prior, Jerilynn C; Papaioannou, Alexandra; Josse, Robert G; Towheed, Tanveer E; Davison, K Shawn; Sawatzky, Richard

    2016-01-01

    Self-reported health status measures, like the Short Form 36-item Health Survey (SF-36), can provide rich information about the overall health of a population and its components, such as physical, mental, and social health. However, differential item functioning (DIF), which arises when population sub-groups with the same underlying (i.e., latent) level of health have different measured item response probabilities, may compromise the comparability of these measures. The purpose of this study was to test for DIF on the SF-36 physical functioning (PF) and mental health (MH) sub-scale items in a Canadian population-based sample. Study data were from the prospective Canadian Multicentre Osteoporosis Study (CaMos), which collected baseline data in 1996-1997. DIF was tested using a multiple indicators multiple causes (MIMIC) method. Confirmatory factor analysis defined the latent variable measurement model for the item responses and latent variable regression with demographic and health status covariates (i.e., sex, age group, body weight, self-perceived general health) produced estimates of the magnitude of DIF effects. The CaMos cohort consisted of 9423 respondents; 69.4% were female and 51.7% were less than 65 years. Eight of 10 items on the PF sub-scale and four of five items on the MH sub-scale exhibited DIF. Large DIF effects were observed on PF sub-scale items about vigorous and moderate activities, lifting and carrying groceries, walking one block, and bathing or dressing. On the MH sub-scale items, all DIF effects were small or moderate in size. SF-36 PF and MH sub-scale scores were not comparable across population sub-groups defined by demographic and health status variables due to the effects of DIF, although the magnitude of this bias was not large for most items. We recommend testing and adjusting for DIF to ensure comparability of the SF-36 in population-based investigations.

  2. Monolithic integrated filters - An overview

    Science.gov (United States)

    Entenmann, W.

    1981-04-01

    An overview of the state of the art in monolithic integrated filter design is given. The close mutual influence of technology and network theory and the continuing development of filter designs with higher integration, higher reliability, lower costs and lower space demands are examined. The fundamental concepts of circuit theory and MOS technology are described and the principal construction of the components of the three major classes of MOS filter circuits examined, namely the change-transfer filter, the switched-capacitor filter and the digital filter. The most important properties, such as the periodicity of the spectra, the impulse response, as well as recursive, nonrecursive, linear and minimal phase filters are covered. Some methods for calculating filter circuits by using classical reactance filter synthesis with the aid of suitable transformations from analog time-continuous reference circuits are discussed. The obtainable signal frequency ranges and filter grades are shown in order to compare the efficiency and operating range of monolithic integrated filter circuits with each other and with other concepts.

  3. Wiener filter for filtered back projection in digital breast tomosynthesis

    Science.gov (United States)

    Wang, Xinying; Mainprize, James G.; Wu, Gang; Yaffe, Martin J.

    2012-03-01

    Conventional filtered back projection (FBP) reconstruction for digital breast tomosynthesis (DBT) can suffer from a low signal to noise ratio. Because of the strong amplification by the reconstruction filters (ramp, apodization and slice thickness), noise at high spatial frequencies can be greatly increased. Image enhancement by Wiener filtering is investigated as a possible method to improve image quality. A neighborhood wavelet coefficient window technique is used to estimate the noise content of projection images and a Wiener filter is applied to the projection images. The neighborhood wavelet coefficient window is a non-linear technique, which may cause the Wiener filters estimated before and after the application of the reconstruction filters to be different. Image quality of a FBP reconstruction with and without Wiener filtering is investigated using a Fourier-based observer detectability metric ( d' ) for evaluation. Simulations of tomosynthesis are performed in both homogeneous and anatomic textured backgrounds containing lowcontrast masses or small microcalcifications. Initial results suggest that improvements in detectability can be achieved when the Wiener filter is applied, especially when the Wiener filter is estimated for the reconstruction filtered projections.

  4. Superconducting notch filter

    Energy Technology Data Exchange (ETDEWEB)

    Pang, C S; Falco, C M; Kampwirth, R T; Schuller, I K; Hudak, J J; Anastasio, T A

    1979-01-01

    Results of a preliminary investigation of a superconducting notch filter for possible application in the 2 to 30 MHz high frequency (HF) communication band are presented. The circuit was successfully implemented using planar geometry so that closed cycle refrigeration could be used to cool circuits fabricated from high T/sub c/ Nb/sub 3/Sn or Nb/sub 3/Ge thin films. In the present design, circuit Q's of about 2 x 10/sup 3/ were obtained with 50-ohm source and output impedance. (TFD)

  5. Spindoktorer et politisk filter

    OpenAIRE

    Talic, Elvedin; Bernt, Rune; Mortensen, Mass Holmegård

    2015-01-01

    Through the TV and other media, many rumors about what a spin-doctor does and the nature of his services have spread. We would like to clarify the function; role and influence the spin-doctor have on Danish politics. We will look specifically at the relationship of power between the Ministers and spin-doctors, and the spin-doctors and media, as some believe that the spin-doctor sometimes will rise to power. We will also take look at the filter function between spin-doctors and media, as it is...

  6. Advances in Collaborative Filtering

    Science.gov (United States)

    Koren, Yehuda; Bell, Robert

    The collaborative filtering (CF) approach to recommenders has recently enjoyed much interest and progress. The fact that it played a central role within the recently completed Netflix competition has contributed to its popularity. This chapter surveys the recent progress in the field. Matrix factorization techniques, which became a first choice for implementing CF, are described together with recent innovations. We also describe several extensions that bring competitive accuracy into neighborhood methods, which used to dominate the field. The chapter demonstrates how to utilize temporal models and implicit feedback to extend models accuracy. In passing, we include detailed descriptions of some the central methods developed for tackling the challenge of the Netflix Prize competition.

  7. Multilevel ensemble Kalman filtering

    KAUST Repository

    Hoel, Hakon

    2016-06-14

    This work embeds a multilevel Monte Carlo sampling strategy into the Monte Carlo step of the ensemble Kalman filter (EnKF) in the setting of finite dimensional signal evolution and noisy discrete-time observations. The signal dynamics is assumed to be governed by a stochastic differential equation (SDE), and a hierarchy of time grids is introduced for multilevel numerical integration of that SDE. The resulting multilevel EnKF is proved to asymptotically outperform EnKF in terms of computational cost versus approximation accuracy. The theoretical results are illustrated numerically.

  8. Charcoal filter testing

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, J. [Nuclear Regulatory Commission, Washington, DC (United States)

    1997-08-01

    In this very brief, informal presentation, a representative of the US Nuclear Regulatory Commission outlines some problems with charcoal filter testing procedures and actions being taken to correct the problems. Two primary concerns are addressed: (1) the process to find the test method is confusing, and (2) the requirements of the reference test procedures result in condensation on the charcoal and causes the test to fail. To address these problems, emergency technical specifications were processed for three nuclear plants. A generic or an administrative letter is proposed as a more permanent solution. 1 fig.

  9. The optimum sunglass filter?

    Science.gov (United States)

    Soederberg, Per G.; Michael, Ralph; Ayala, Marcelo; Wu, Jiangmei; Loefgren, Stefan; Merriam, John; Chen, Enping

    1999-06-01

    It is concluded that sunglasses shall block UVR and toxic blue light, allow transmittance of signal light and bring luminous intensity behind the filters to a comfortable level. It was found that some commercially available sunglasses, apart from one pair of photochromatic dark state lenses tested, block ultraviolet radiation (UVR) adequately. Further, it was found that it is possible to block the toxic blue radiation without interfering substantially on blue signal light perception. However, none of the sunglasses tested blocked the toxic blue light enough.

  10. Digital Filters for Low Frequency Equalization

    DEFF Research Database (Denmark)

    Tyril, Marni; Abildgaard, J.; Rubak, Per

    2001-01-01

    Digital filters with high resolution in the low-frequency range are studied. Specifically, for a given computational power, traditional IIR filters are compared with warped FIR filters, warped IIR filters, and modified warped FIR filters termed warped individual z FIR filters (WizFIR). The results...

  11. Filter Media Tests Under Simulated Martian Atmospheric Conditions

    Science.gov (United States)

    Agui, Juan H.

    2016-01-01

    Human exploration of Mars will require the optimal utilization of planetary resources. One of its abundant resources is the Martian atmosphere that can be harvested through filtration and chemical processes that purify and separate it into its gaseous and elemental constituents. Effective filtration needs to be part of the suite of resource utilization technologies. A unique testing platform is being used which provides the relevant operational and instrumental capabilities to test articles under the proper simulated Martian conditions. A series of tests were conducted to assess the performance of filter media. Light sheet imaging of the particle flow provided a means of detecting and quantifying particle concentrations to determine capturing efficiencies. The media's efficiency was also evaluated by gravimetric means through a by-layer filter media configuration. These tests will help to establish techniques and methods for measuring capturing efficiency and arrestance of conventional fibrous filter media. This paper will describe initial test results on different filter media.

  12. Adverse learning strategy: the Adelaide Diagnostic Learning Inventory and its subscale replicability in a medical student population.

    Science.gov (United States)

    Welch, G; Pearce, K; Lewis, M; Mellsop, G

    1990-03-01

    The Adelaide Diagnostic Learning Inventory (ADLIMS) is a measure of learning styles and learning pathologies that was designed to investigate the impact of traditional approaches to learning versus problem-based learning and to identify students whose approach to learning tasks predicted poor academic performance. In this study, some important psychometric properties of the ADLIMS were examined, including its factor structure. In this study, factor replicability across samples was argued to provide a more robust and psychologically meaningful factor solution than that which can be obtained using traditional mathematical criteria. The results of the factor analysis did not confirm the presence of the four factor solution earlier reported for the ADLIMS, but did identify three clear factors that had very high replicability. An inspection of the items comprising these three factors showed that factor 1 tapped subjective distress related to poor study habits, lack of motivation to study, and distraction from social activities. Factor 2 tapped distress arising from high achievement expectations that were hampered by superficial or disorganized study habits that did not enable the student to grasp the relationships between concepts and ideas. Factor 3 tapped positive feelings and a sense of satisfaction associated with a problem-based approach to the learning of new study material. Although the internal reliability of the ADLIMS subscales met the requirements of a measure to be used in general research such as in the investigation of correlates among groups of medical students, they did not meet the higher requirements of a measure to be used to identify or predict individuals with pathological learning styles.

  13. Subscale Carbon-Carbon Nozzle Extension Development and Hot Fire Testing in Support of Upper Stage Liquid Rocket Engines

    Science.gov (United States)

    Gradl, Paul; Valentine, Peter; Crisanti, Matthew; Greene, Sandy Elam

    2016-01-01

    Upper stage and in-space liquid rocket engines are optimized for performance through the use of high area ratio nozzles to fully expand combustion gases to low exit pressures increasing exhaust velocities. Due to the large size of such nozzles and the related engine performance requirements, carbon-carbon (C/C) composite nozzle extensions are being considered for use in order to reduce weight impacts. NASA and industry partner Carbon-Carbon Advanced Technologies (C-CAT) are working towards advancing the technology readiness level of large-scale, domestically-fabricated, C/C nozzle extensions. These C/C extensions have the ability to reduce the overall costs of extensions relative to heritage metallic and composite extensions and to decrease weight by 50%. Material process and coating developments have advanced over the last several years, but hot fire testing to fully evaluate C/C nozzle extensions in relevant environments has been very limited. NASA and C-CAT have designed, fabricated and hot fire tested multiple subscale nozzle extension test articles of various C/C material systems, with the goal of assessing and advancing the manufacturability of these domestically producible materials as well as characterizing their performance when subjected to the typical environments found in a variety of liquid rocket and scramjet engines. Testing at the MSFC Test Stand 115 evaluated heritage and state-of-the-art C/C materials and coatings, demonstrating the capabilities of the high temperature materials and their fabrication methods. This paper discusses the design and fabrication of the 1.2k-lbf sized carbon-carbon nozzle extensions, provides an overview of the test campaign, presents results of the hot fire testing, and discusses potential follow-on development work.

  14. Less Is More: Using Static-2002R Subscales to Predict Violent and General Recidivism Among Sexual Offenders.

    Science.gov (United States)

    Babchishin, Kelly M; Hanson, R Karl; Blais, Julie

    2016-04-01

    Given that sexual offenders are more likely to reoffend with a nonsexual offense than a sexual offense, it is useful to have risk scales that predict general recidivism among sexual offenders. In the current study, we examined the extent to which two commonly used risk scales for sexual offenders (Static-99R and Static-2002R) predict violent and general recidivism, and whether it would be possible to improve predictive accuracy for these outcomes by revising their items. Based on an aggregated sample of 3,536 adult male sex offenders from Canada, the United States, and Europe (average age of 39 years), we found that a scale created from the Age at Release item and the General Criminality subscale of Static-2002R predicted nonsexual violent, any violent, and general recidivism significantly better than Static-99R or Static-2002R total scores. The convergent validity of this new scale (Brief Assessment of Recidivism Risk-2002R [BARR-2002R]) was examined in a new, independent data set of Canadian high-risk adult male sex offenders (N = 360) where it was found to be highly correlated with other risk assessment tools for general recidivism and the Psychopathy Checklist-Revised (PCL-R), as well as demonstrated similar discrimination and calibration as in the development sample. Instead of using total scores from the Static-99R or Static-2002R, we recommend that evaluators use the BARR-2002R for predicting violent and general recidivism among sex offenders, and for screening for the psychological dimension of antisocial orientation. © The Author(s) 2015.

  15. From Microwave Filter to Digital Filter and Back Again

    DEFF Research Database (Denmark)

    Dalby, Arne Brejning

    1989-01-01

    A new very simple state variable flow graph representation for interdigital transmission line bandpass filters is presented, which has led to two important results: 1) A new type of digital filter with properties, that surpass the properties of most other (all pole) digital filtertypes. 2......) The study of the new digital filtertype has led to design formulas for interdigital transmission line filters that are very simple compared to the hitherto known formulas. The accuracy is the same or better....

  16. Modal and Vibration Analysis of Filter System in Petrochemical Plant

    Directory of Open Access Journals (Sweden)

    Zhongchi Liu

    2017-01-01

    Full Text Available Filter systems are widely used in petrochemical plants for removing solid impurities from hydrocarbon oils. The backwash is the cleaning process used to remove the impurities on the sieves of the filters without a need to interrupt the operation of the entire system. This paper presents a case study based on the actual project of a filter system in a petrochemical plant, to demonstrate the significant effect of vibration on the structural integrity of piping. The induced vibration had led to the structural fatigue failure of the pipes connecting the filter system. A preliminary assessment suggested that the vibrations are caused by the operation of backwashing of the filter system. A process for solving the vibration problem based on the modal analysis of the filter system using the commercial finite element software for simulation is therefore proposed. The computed natural frequencies of the system and the vibration data measured on site are assessed based on the resonance effect of the complete system including the piping connected to the filters. Several approaches are proposed to adjust the natural frequencies of the system in such a way that an optimal and a reasonable solution for solving the vibration problem is obtained.

  17. Element 115

    OpenAIRE

    Forsberg, Ulrika

    2016-01-01

    This thesis is devoted to detailed studies of element 115 decay chains using the highly efficient multi-coincidence alpha, electron, gamma and X-ray detector setup TASISpec at the gas-filled separator TASCA at GSI, Darmstadt, Germany. In a three-week long experiment thirty new decay chains assumed to stem from element 115 isotopes were observed together with the very first detections of gamma rays and potential X-rays from these nuclei. Paper I describes preparations in terms of optimisations...

  18. DSP Control of Line Hybrid Active Filter

    DEFF Research Database (Denmark)

    Dan, Stan George; Benjamin, Doniga Daniel; Magureanu, R.

    2005-01-01

    Active Power Filters have been intensively explored in the past decade. Hybrid active filters inherit the efficiency of passive filters and the improved performance of active filters, and thus constitute a viable improved approach for harmonic compensation. In this paper a parallel hybrid filter ...... active filter. Simulation and experimental results obtained in laboratory confirmed the validity and effectiveness of the control.......Active Power Filters have been intensively explored in the past decade. Hybrid active filters inherit the efficiency of passive filters and the improved performance of active filters, and thus constitute a viable improved approach for harmonic compensation. In this paper a parallel hybrid filter...... is studied for current harmonic compensation. The hybrid filter is formed by a single tuned Le filter and a small-rated power active filter, which are directly connected in series without any matching transformer. Thus the required rating of the active filter is much smaller than a conventional standalone...

  19. Filter and Filter Bank Design for Image Texture Recognition

    Energy Technology Data Exchange (ETDEWEB)

    Randen, Trygve

    1997-12-31

    The relevance of this thesis to energy and environment lies in its application to remote sensing such as for instance sea floor mapping and seismic pattern recognition. The focus is on the design of two-dimensional filters for feature extraction, segmentation, and classification of digital images with textural content. The features are extracted by filtering with a linear filter and estimating the local energy in the filter response. The thesis gives a review covering broadly most previous approaches to texture feature extraction and continues with proposals of some new techniques. 143 refs., 59 figs., 7 tabs.

  20. Leukodepletion blood filters: filter design and mechanisms of leukocyte removal.

    Science.gov (United States)

    Dzik, S

    1993-04-01

    Modern leukocyte removal filters have been developed after years of refinement in design. Current filters are composite filters in which synthetic microfiber material is prepared as a nonwoven web. The filter material may be surface modified to alter surface tension or charge to improve performance. The housing design promotes effective contact of blood with the filter material and decreases shear forces. The exact mechanisms by which these filters remove leukocytes from blood components are uncertain, but likely represent a combination of both physical and biological processes whose contributions to leukocyte removal are interdependent. Small-pore microfiber webs result in barrier phenomena that permit retention of individual cells and increase the total adsorptive area of the filter. Modifications in surface charge can increase or decrease cell attraction to the fibers. Optimum interfacial surface tensions between blood cells, plasma, and filter fibers not only permit effective blood flow through small fiber pores, but also facilitate cell contact with the material. Barrier retention is a common mechanism for all modern leukocyte-removal filters and applies to all leukocyte subtypes. Because barrier retention does not depend on cell viability, it is operative for cells of any age and will retain any nondeformable cell, including whole nuclei from lymphocytes or monocytes. Barrier retention is supplemented by retention by adhesion. RBCs, lymphocytes, monocytes, granulocytes, and platelets differ in their relative adhesiveness to filter fibers. Different adhesive mechanisms are used in filters designed for RBCs compared with filters designed for platelets. Although lymphocytes, monocytes, and granulocytes can adhere directly to filter fibers, the biological mechanisms underlying cell adhesion may differ for these cell types. These differences may depend on expression of cell adhesion molecules. In the case of filtration of fresh RBCs, platelet-leukocyte interaction

  1. Stabilizing an optoelectronic microwave oscillator with photonic filters

    Science.gov (United States)

    Strekalov, D.; Aveline, D.; Yu, N.; Thompson, R.; Matsko, A. B.; Maleki, L.

    2003-01-01

    This paper compares methods of active stabilization of an optoelectronic microwave oscillator (OEO) based on insertion of a source of optical group delay into an OEO loop. The performance of an OEO stabilized with either a high- optical cavity or an atomic cell is analyzed. We show that the elements play a role of narrow-band microwave filters improving an OEO stability.

  2. Self Control of Chaotic Dynamics using LTI Filters

    CERN Document Server

    Mitra, P

    1997-01-01

    In this brief, an algorithm for controlling chaotic systems using small, continuous time perturbations is presented. Stabilisation is achieved by self controlling feedback using low order LTI filters. The algorithm alleviates the need of complex calculati ons or costly delay elements, and can be implemented in a wide variety of systems using simple circuit elments only.

  3. Tandem HEPA filter tests.

    Science.gov (United States)

    Schuster, B G; Osetek, D J

    1978-02-01

    Current methods for evaluating the performance and reliability of high-efficiency air cleaning systems use forward light-scattering photometers and DOP aerosol. This method is limited to measuring protection factors of 10(4) or 10(5) and has poor sensitivity to particles less than .3 micron. More accurate determination of system performance could be made by measuring two filter stages with a single test. Because of the large protection factors of a two-stage system, it is necessary to use high challenge aerosol concentrations and long downstream sampling times. Concentrations were measured using an intra-cavity laser light-scattering aerosol spectrometer which is capable of detection of single particles ranging in size from 0.07 to 3.00 micron diameter. The results of several tests with challenge aerosols of both NaCl and DOP yielded protection factors ranging from 1.4 x 10(7) to 3.0 x 10(9) for two HEPA filters in series.

  4. Measurement of aggressive behaviors in dementia: comparison of the physical aggression subscales of the Cohen-Mansfield Agitation Inventory and the Ryden Aggression Scale.

    Science.gov (United States)

    Whall, Ann L; Kim, Hyojeong; Colling, Kathleen Byrne; Hong, Gwi-Ryung; DeCicco, Barry; Antonakos, Cathy

    2013-07-01

    One of the central issues in the development of research-based interventions for aggressive behavior (AB) in late-stage dementia is the provision of precise measurement of the major dependent variable, in this case, AB levels. To advance the nursing goal of evidence-based practice, this article presents the characteristics of two research instruments: the Cohen-Mansfield Agitation Inventory (CMAI) aggressive behavior subscale (CMAI-ABS) and the Ryden Aggression Scale (RAS) physically aggressive behavior subscale (RAS-PABS). A total of 282 shower bath events (which are most associated with AB) were observed for 107 nursing home residents with dementia in nine randomly selected nursing homes. Then, we compared the psychometric properties of the CMAI-ABS and the RAS-PABS. Moderate to substantial agreements between the two instruments were identified using Cohen's Kappa. A similar percentage of AB was found on both subscales. Similar items on both subscales, such as hitting and pushing, were moderately correlated. Overall, the study results support that the CMAI-ABS and RAS-PABS measure a single but multifaceted construct-physically aggressive behavior in dementia. Copyright 2013, SLACK Incorporated.

  5. Complex Relationships Among Masculine Norms and Health/Well-Being Outcomes: Correlation Patterns of the Conformity to Masculine Norms Inventory Subscales.

    Science.gov (United States)

    Gerdes, Zachary T; Levant, Ronald F

    2018-03-01

    The Conformity to Masculine Norms Inventory (CMNI) is a widely used multidimensional scale. Studies using the CMNI most often report only total scale scores, which are predominantly associated with negative outcomes. Various studies since the CMNI's inception in 2003 using subscales have reported both positive and negative outcomes. The current content analysis examined studies ( N = 17) correlating the 11 subscales with 63 criterion variables across 7 categories. Most findings were consistent with past research using total scale scores that reported negative outcomes. For example, conformity to masculine norms has been inversely related to help-seeking and positively correlated with concerning health variables, such as substance use. Nonetheless, past reliance on total scores has obscured the complexity of associations with the CMNI in that 30% of the findings in the present study reflected positive outcomes, particularly for health promotion. Subscales differed in their relationships with various outcomes: for one subscale they were predominantly positive, but six others were mostly negative. The situational and contextual implications of conformity to masculine norms and their relationships to positive and negative outcomes are discussed.

  6. Toward defining a cutoff score for elevated fear of hypoglycemia on the hypoglycemia fear survey worry subscale in patients with type 2 diabetes

    DEFF Research Database (Denmark)

    Hajós, Tibor R S; Polonsky, William H; Pouwer, Frans

    2014-01-01

    OBJECTIVE To determine a cutoff score for clinically meaningful fear of hypoglycemia (FoH) on the Hypoglycemia Fear Survey Worry subscale (HFS-W). RESEARCH DESIGN AND METHODS Data on the HFS-W, history of hypoglycemia, emotional well-being (World Health Organization-5 well-being index...

  7. Computer-generated optical multiwavelet filters for hybrid image-classification systems.

    Science.gov (United States)

    Stollfuss, A; Teiwes, S; Wyrowski, F

    1995-08-10

    Optical coherent Fourier correlators are applicable in real-time image analysis such as image classification. The functionality of Fourier correlators can be increased by use of multifunctional filters, which have many spatially multiplexed impulse responses. The concept of multiresolution analysis on the basis of wavelet theory offers profitable methods to design multifunctional filters for image analysis. The applicability of such filters is demonstrated by an example in which different characteristic textures of medical images are extracted. The physical implementation of multiwavelet filters is restricted by modulation-domain constraints imposed by the use of spatial-light-modulator or of diffractive-element fabrication technology. Coding methods of diffractive optics are shown to be helpful to transform the original complex-valued distributions of multiwavelet filters into light-efficient quantized phase-only distributions by preservation of the original filter functionality. The quality of the designed diffractive phase filters is documented by computer experiments.

  8. Rancang Bangun Bandpass Filter untuk aplikasi Long Term Evolution (LTE Frekuensi 1,8 GHz

    Directory of Open Access Journals (Sweden)

    Teguh Firmansyah

    2018-01-01

    Full Text Available Filter is a device to pass a particular frequency by passing wanted frequency and reduce unwanted frequencies. The frequency that used is depend on the applications used. Based on the frequency regions that are passed, the filter is divideed into several type: Lowpass Filter (LPF, Bandpass Filter (BPF, Highpass Filter (HPF, and Bandstop Filter (BSF. This script was aimed to realized Bandpass Filter (BPF at frequency 1,8 GHz for long term evolution (LTE. The filter is a hairpin filter, which is one method of designing a distributed element filter with λg/2 length of resonators that is parallel coupled and have resonators topology as ‘U’ shape. Realization of this filters was using microstrip with FR4-Epoxy material as a transmission channel. The information filter performance was measured by using network analyzer. In this BPF designing and realizing, some of the parameters measured are frequency respone, bandwidth, insertion loss, return loss, Voltage Standing Wave Ratio (VSWR. The result of BPF characteristics measurements are: center frequency at 1,8 GHz with 360 MHz bandwidth, insertion loss 8,4 dB, return loss 11,42 dB, VSWR 1,14.

  9. Experimental studies of flax-containing nonwoven fabric properties as a filter material

    Science.gov (United States)

    Nemirova, L. F.; Shtabnova, V. L.; Litunov, S. N.; Filkin, N. Yu.

    2017-08-01

    Nonwoven fabric (it consists of 50 % of modified flax fiber and a structure obtained by knitting the fabric with the scrim fibers) was examined. Air permeability, dust permeability, wind resistance and tensile strength at parameter range characteristic for industrial premises were determined. Findings support the use of the fabric as a filter material for filter elements.

  10. Efficiency of Deposit Dissolution in Water Well Filters by Acid Reagents

    Directory of Open Access Journals (Sweden)

    V. V. Ivashechkin

    2006-01-01

    Full Text Available The paper considers some problems of efficient dissolution of contaminative deposits by acid reagents which are accumulated in the pores of gravelling and water well filters.Tests of reagents in terms of their corrosive effect on the elements of a well filter have been carried out.

  11. Optical filtering techniques

    Science.gov (United States)

    Psaltis, D.

    1986-03-01

    The purpose of this study was to examine the potential of using optical information processing technology for adaptive antenna beamforming and null steering. The adaptive beamforming/null steering problem consists of estimation of the covariance matrix of the noise field and inversion of the covariance matrix to obtain the antenna element weights which optimize the antennas of the covariance matrix to obtain the antenna element weights which optimize the antenna's directional characteristics (gain pattern). This report examines the adaptive beamforming/nulling problem in view of the capabilities of optics and identifies areas where optics can be used to benefit.

  12. Note: cryogenic coaxial microwave filters.

    Science.gov (United States)

    Tancredi, G; Schmidlin, S; Meeson, P J

    2014-02-01

    The careful filtering of microwave electromagnetic radiation is critical for controlling the electromagnetic environment for experiments in solid-state quantum information processing and quantum metrology at millikelvin temperatures. We describe the design and fabrication of a coaxial filter assembly and demonstrate that its performance is in excellent agreement with theoretical modelling. We further perform an indicative test of the operation of the filters by making current-voltage measurements of small, underdamped Josephson junctions at 15 mK.

  13. Multi-filter spectrophotometry simulations

    Science.gov (United States)

    Callaghan, Kim A. S.; Gibson, Brad K.; Hickson, Paul

    1993-01-01

    To complement both the multi-filter observations of quasar environments described in these proceedings, as well as the proposed UBC 2.7 m Liquid Mirror Telescope (LMT) redshift survey, we have initiated a program of simulated multi-filter spectrophotometry. The goal of this work, still very much in progress, is a better quantitative assessment of the multiband technique as a viable mechanism for obtaining useful redshift and morphological class information from large scale multi-filter surveys.

  14. Faraday anomalous dispersion optical filters

    Science.gov (United States)

    Shay, T. M.; Yin, B.; Alvarez, L. S.

    1993-01-01

    The effect of Faraday anomalous dispersion optical filters on infrared and blue transitions of some alkali atoms is calculated. A composite system is designed to further increase the background noise rejection. The measured results of the solar background rejection and image quality through the filter are presented. The results show that the filter may provide high transmission and high background noise rejection with excellent image quality.

  15. Assessment of exhaust emissions from carbon nanotube production and particle collection by sampling filters.

    Science.gov (United States)

    Tsai, Candace Su-Jung; Hofmann, Mario; Hallock, Marilyn; Ellenbecker, Michael; Kong, Jing

    2015-11-01

    This study performed a workplace evaluation of emission control using available air sampling filters and characterized the emitted particles captured in filters. Characterized particles were contained in the exhaust gas released from carbon nanotube (CNT) synthesis using chemical vapor deposition (CVD). Emitted nanoparticles were collected on grids to be analyzed using transmission electron microscopy (TEM). CNT clusters in the exhaust gas were collected on filters for investigation. Three types of filters, including Nalgene surfactant-free cellulose acetate (SFCA), Pall A/E glass fiber, and Whatman QMA quartz filters, were evaluated as emission control measures, and particles deposited in the filters were characterized using scanning transmission electron microscopy (STEM) to further understand the nature of particles emitted from this CNT production. STEM analysis for collected particles on filters found that particles deposited on filter fibers had a similar morphology on all three filters, that is, hydrophobic agglomerates forming circular beaded clusters on hydrophilic filter fibers on the collecting side of the filter. CNT agglomerates were found trapped underneath the filter surface. The particle agglomerates consisted mostly of elemental carbon regardless of the shapes. Most particles were trapped in filters and no particles were found in the exhaust downstream from A/E and quartz filters, while a few nanometer-sized and submicrometer-sized individual particles and filament agglomerates were found downstream from the SFCA filter. The number concentration of particles with diameters from 5 nm to 20 µm was measured while collecting particles on grids at the exhaust piping. Total number concentration was reduced from an average of 88,500 to 700 particle/cm(3) for the lowest found for all filters used. Overall, the quartz filter showed the most consistent and highest particle reduction control, and exhaust particles containing nanotubes were successfully

  16. Adaptive filtering and change detection

    CERN Document Server

    Gustafsson, Fredrik

    2003-01-01

    Adaptive filtering is a classical branch of digital signal processing (DSP). Industrial interest in adaptive filtering grows continuously with the increase in computer performance that allows ever more conplex algorithms to be run in real-time. Change detection is a type of adaptive filtering for non-stationary signals and is also the basic tool in fault detection and diagnosis. Often considered as separate subjects Adaptive Filtering and Change Detection bridges a gap in the literature with a unified treatment of these areas, emphasizing that change detection is a natural extensi

  17. Limits of search filter development.

    Science.gov (United States)

    Wilczynski, Nancy L; Lokker, Cynthia; McKibbon, Kathleen Ann; Hobson, Nicholas; Haynes, R Brian

    2016-01-01

    The research attempted to develop search filters for biomedical literature databases that improve retrieval of studies of clinical relevance for the nursing and rehabilitation professions. Diagnostic testing framework compared machine-culled and practitioner-nominated search terms with a hand-tagged clinical literature database. We were unable to: (1) develop filters for nursing, likely because of the overlapping and expanding scope of practice for nurses in comparison with medical professionals, or (2) develop filters for rehabilitation, because of its broad scope and the profession's multifaceted understanding of "health and ability." We found limitations on search filter development for these health professions: nursing and rehabilitation.

  18. Apparatus comprising trace element dosage and method for treating raw water in biofilter

    DEFF Research Database (Denmark)

    2015-01-01

    elements such as certain metals (Cu, Co, Cr, Mo, Ni, W, Zn or a mixture thereof). The apparatus comprising - a volume provided with an inlet (2) for raw water and an outlet (3) for water having been subjected to microbial activity, a filter and a trace element dosage device (13) are placed in this volume...... the inlet (2) to the outlet (3) or in the reverse direction, - the trace element dosage device (13) is positioned upstream of the porous filter material and microbial biomass and is configured to dose trace element(s) to the water flowing through the filter. A method for treating raw water by microbial...

  19. The intractable cigarette 'filter problem'.

    Science.gov (United States)

    Harris, Bradford

    2011-05-01

    When lung cancer fears emerged in the 1950s, cigarette companies initiated a shift in cigarette design from unfiltered to filtered cigarettes. Both the ineffectiveness of cigarette filters and the tobacco industry's misleading marketing of the benefits of filtered cigarettes have been well documented. However, during the 1950s and 1960s, American cigarette companies spent millions of dollars to solve what the industry identified as the 'filter problem'. These extensive filter research and development efforts suggest a phase of genuine optimism among cigarette designers that cigarette filters could be engineered to mitigate the health hazards of smoking. This paper explores the early history of cigarette filter research and development in order to elucidate why and when seemingly sincere filter engineering efforts devolved into manipulations in cigarette design to sustain cigarette marketing and mitigate consumers' concerns about the health consequences of smoking. Relevant word and phrase searches were conducted in the Legacy Tobacco Documents Library online database, Google Patents, and media and medical databases including ProQuest, JSTOR, Medline and PubMed. 13 tobacco industry documents were identified that track prominent developments involved in what the industry referred to as the 'filter problem'. These reveal a period of intense focus on the 'filter problem' that persisted from the mid-1950s to the mid-1960s, featuring collaborations between cigarette producers and large American chemical and textile companies to develop effective filters. In addition, the documents reveal how cigarette filter researchers' growing scientific knowledge of smoke chemistry led to increasing recognition that filters were unlikely to offer significant health protection. One of the primary concerns of cigarette producers was to design cigarette filters that could be economically incorporated into the massive scale of cigarette production. The synthetic plastic cellulose acetate

  20. Development of a practicable measuring method for continuous determination of the concentration and particle size distribution of dusts in air filter elements. Part project: Development of the scientific groundwork. Final report; Entwicklung eines feldtauglichen Messverfahrens zur kontinuierlichen Bestimmung der Konzentration und Groessenverteilung von Staeuben an Luftfiltereinsaetzen. Teilprojekt: Erarbeitung der wissenschaftlichen Grundlagen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Weichert, R.; Rulik, O.

    1997-06-01

    Filters may be used for reducing emissions of particulate pollutants from processing plants or for air cleaning in ventilation plants. The efficiency of a filter depends on its material, design, and operating conditions, notably the concentration and size of partciles, and on its load, i.e., its working hours. The purpose of the present project was to develop an inexpensive, easy-to-use, practicable measuring method for on-line measurement of the concentration and particle size distribution of dusts upstream (raw gas) and downstream (clean gas) of filters installed in processing plants, thus providing a means of continuously monitoring filter efficiency. The measuring principle of the developed method is based on the light scatter produced by individual particles passing through the measuring zone. The particle size measuring range is from 0.3 to 30 {mu}m, thus providing for the majority of all respirable dusts. The concentration measuring range is from a few mg/m{sup 3} on the clean gas side up to several g/m{sup 3} on the raw gas side. Special measures were needed to accomodate such a wide concentration range in a single measuring device. One of tasks of the study was to develop the technology required for this. (orig./SR) [Deutsch] Zur Minderung von Emissionen partikelfoermiger Schadstoffe aus verfahrenstechnischen Anlagen sowie zur Reinhaltung der Luft in Lueftungsanlagen werden Filter eingesetzt. Die Wirksamkeit dieser Filter haengt ab - von Material und Aufbau des Filters, von den Betriebsbedingungen des Filters, insbesondere von der Konzentration und der Groesse der Partikel und - von der Beladung des Filters, d.h. von seiner Betriebsdauer. Ziel des Vorhabens ist es, ein kostenguenstiges, handliches und feldtaugliches Messgeraet zu entwickeln, mit dem in technischen Anlagen die Konzentration und Groessenverteilung von Staeuben sowohl vor dem Filter (Rohgas) als auch hinter dem Filter (Reingas) on-line gemessen und so die Wirksamkeit des Filters

  1. Construct Validity and Reliability of the SARA Gait and Posture Sub-scale in Early Onset Ataxia

    Directory of Open Access Journals (Sweden)

    Tjitske F. Lawerman

    2017-12-01

    Full Text Available Aim: In children, gait and posture assessment provides a crucial marker for the early characterization, surveillance and treatment evaluation of early onset ataxia (EOA. For reliable data entry of studies targeting at gait and posture improvement, uniform quantitative biomarkers are necessary. Until now, the pediatric test construct of gait and posture scores of the Scale for Assessment and Rating of Ataxia sub-scale (SARA is still unclear. In the present study, we aimed to validate the construct validity and reliability of the pediatric (SARAGAIT/POSTURE sub-scale.Methods: We included 28 EOA patients [15.5 (6–34 years; median (range]. For inter-observer reliability, we determined the ICC on EOA SARAGAIT/POSTURE sub-scores by three independent pediatric neurologists. For convergent validity, we associated SARAGAIT/POSTURE sub-scores with: (1 Ataxic gait Severity Measurement by Klockgether (ASMK; dynamic balance, (2 Pediatric Balance Scale (PBS; static balance, (3 Gross Motor Function Classification Scale -extended and revised version (GMFCS-E&R, (4 SARA-kinetic scores (SARAKINETIC; kinetic function of the upper and lower limbs, (5 Archimedes Spiral (AS; kinetic function of the upper limbs, and (6 total SARA scores (SARATOTAL; i.e., summed SARAGAIT/POSTURE, SARAKINETIC, and SARASPEECH sub-scores. For discriminant validity, we investigated whether EOA co-morbidity factors (myopathy and myoclonus could influence SARAGAIT/POSTURE sub-scores.Results: The inter-observer agreement (ICC on EOA SARAGAIT/POSTURE sub-scores was high (0.97. SARAGAIT/POSTURE was strongly correlated with the other ataxia and functional scales [ASMK (rs = -0.819; p < 0.001; PBS (rs = -0.943; p < 0.001; GMFCS-E&R (rs = -0.862; p < 0.001; SARAKINETIC (rs = 0.726; p < 0.001; AS (rs = 0.609; p = 0.002; and SARATOTAL (rs = 0.935; p < 0.001]. Comorbid myopathy influenced SARAGAIT/POSTURE scores by concurrent muscle weakness, whereas comorbid myoclonus predominantly influenced

  2. TARGET/CRYOCHIL - THERMODYNAMIC ANALYSIS AND SUBSCALE MODELING OF SPACE-BASED ORBIT TRANSFER VEHICLE CRYOGENIC PROPELLANT RESUPPLY

    Science.gov (United States)

    Defelice, D. M.

    1994-01-01

    The resupply of the cryogenic propellants is an enabling technology for space-based transfer vehicles. As part of NASA Lewis's ongoing efforts in micro-gravity fluid management, thermodynamic analysis and subscale modeling techniques have been developed to support an on-orbit test bed for cryogenic fluid management technologies. These efforts have been incorporated into two FORTRAN programs, TARGET and CRYOCHIL. The TARGET code is used to determine the maximum temperature at which the filling of a given tank can be initiated and subsequently filled to a specified pressure and fill level without venting. The main process is the transfer of the energy stored in the thermal mass of the tank walls into the inflowing liquid. This process is modeled by examining the end state of the no-vent fill process. This state is assumed to be at thermal equilibrium between the tank and the fluid which is well mixed and saturated at the tank pressure. No specific assumptions are made as to the processes or the intermediate thermodynamic states during the filling. It is only assumed that the maximum tank pressure occurs at the final state. This assumption implies that, during the initial phases of the filling, the injected liquid must pass through the bulk vapor in such a way that it absorbs a sufficient amount of its superheat so that moderate tank pressures can be maintained. It is believed that this is an achievable design goal for liquid injection systems. TARGET can be run with any fluid for which the user has a properties data base. Currently it will only run for hydrogen, oxygen, and nitrogen since pressure-enthalpy data sets have been included for these fluids only. CRYOCHIL's primary function is to predict the optimum liquid charge to be injected for each of a series of charge-hold-vent chilldown cycles. This information can then be used with specified mass flow rates and valve response times to control a liquid injection system for tank chilldown operations. This will

  3. Bridging the ensemble Kalman filter and particle filters

    Energy Technology Data Exchange (ETDEWEB)

    Stordal, Andreas Stoerksen; Karlsen, Hans A.; Naevdal, Geir; Skaug, Hans J.; Valles, Brice

    2009-12-15

    The nonlinear filtering problem occurs in many scientific areas. Sequential Monte Carlo solutions with the correct asymptotic behavior such as particle filters exist but they are computationally too expensive when working with high-dimensional systems. The ensemble Kalman filter is a more robust method that has shown promising results with a small sample size but the samples are not guaranteed to come from the true posterior distribution. By approximating the model error with Gaussian kernels we get the advantage of both a Kalman correction and a weighting step. The resulting Gaussian mixture filter has the advantage of both a local Kalman type correction and the weighting/re sampling step of a particle filter. The Gaussian mixture approximation relies on a tunable bandwidth parameter which often has to be kept quite large in order to avoid weight collapse in high dimensions. As a result, the Kalman correction is too large to capture highly non-Gaussian posterior distributions. In this paper we have extended the Gaussian mixture filter (Hoteit et al., 2008b) and also made the connection to particle filters more transparent. In particular we introduce a tuning parameter for the importance weights. In the last part of the paper we have performed a simulation experiment with the Lorenz40 model where our method has been compared to the EnKF and a full implementation of a particle filter. The results clearly indicate that the new method has advantages compared to the standard EnKF. (Author)

  4. Magnetic filtration process, magnetic filtering material, and methods of forming magnetic filtering material

    Science.gov (United States)

    Taboada-Serrano, Patricia; Tsouris, Constantino; Contescu, Cristian I; McFarlane, Joanna

    2013-10-08

    The present invention provides magnetically responsive activated carbon, and a method of forming magnetically responsive activated carbon. The method of forming magnetically responsive activated carbon typically includes providing activated carbon in a solution containing ions of ferrite forming elements, wherein at least one of the ferrite forming elements has an oxidation state of +3 and at least a second of the ferrite forming elements has an oxidation state of +2, and increasing pH of the solution to precipitate particles of ferrite that bond to the activated carbon, wherein the activated carbon having the ferrite particles bonded thereto have a positive magnetic susceptibility. The present invention also provides a method of filtering waste water using magnetic activated carbon.

  5. Kalman Filter Desing, Smoothing and Analysis

    OpenAIRE

    Cederkvist, Henrik Rene

    2001-01-01

    Thesis is based on three different aspects of Kalman filtering. >Kalman filters for navigation. Investigate the difference between a Extended Kalman Filter and a Linearized Kalman Filter with feedback. And show how different system models relate to these Kalman Filters when implemented in a filter. >Smoothing. Investigate how much there is to be gained from smoothing. We will only look at the fixed-interval smoother, using the method of forward and backward filtering. ...

  6. Particle Kalman Filtering: A Nonlinear Framework for Ensemble Kalman Filters

    KAUST Repository

    Hoteit, Ibrahim

    2010-09-19

    Optimal nonlinear filtering consists of sequentially determining the conditional probability distribution functions (pdf) of the system state, given the information of the dynamical and measurement processes and the previous measurements. Once the pdfs are obtained, one can determine different estimates, for instance, the minimum variance estimate, or the maximum a posteriori estimate, of the system state. It can be shown that, many filters, including the Kalman filter (KF) and the particle filter (PF), can be derived based on this sequential Bayesian estimation framework. In this contribution, we present a Gaussian mixture‐based framework, called the particle Kalman filter (PKF), and discuss how the different EnKF methods can be derived as simplified variants of the PKF. We also discuss approaches to reducing the computational burden of the PKF in order to make it suitable for complex geosciences applications. We use the strongly nonlinear Lorenz‐96 model to illustrate the performance of the PKF.

  7. Differential Item Functioning in the SF-36 Physical Functioning and Mental Health Sub-Scales: A Population-Based Investigation in the Canadian Multicentre Osteoporosis Study.

    Directory of Open Access Journals (Sweden)

    Lisa M Lix

    Full Text Available Self-reported health status measures, like the Short Form 36-item Health Survey (SF-36, can provide rich information about the overall health of a population and its components, such as physical, mental, and social health. However, differential item functioning (DIF, which arises when population sub-groups with the same underlying (i.e., latent level of health have different measured item response probabilities, may compromise the comparability of these measures. The purpose of this study was to test for DIF on the SF-36 physical functioning (PF and mental health (MH sub-scale items in a Canadian population-based sample.Study data were from the prospective Canadian Multicentre Osteoporosis Study (CaMos, which collected baseline data in 1996-1997. DIF was tested using a multiple indicators multiple causes (MIMIC method. Confirmatory factor analysis defined the latent variable measurement model for the item responses and latent variable regression with demographic and health status covariates (i.e., sex, age group, body weight, self-perceived general health produced estimates of the magnitude of DIF effects.The CaMos cohort consisted of 9423 respondents; 69.4% were female and 51.7% were less than 65 years. Eight of 10 items on the PF sub-scale and four of five items on the MH sub-scale exhibited DIF. Large DIF effects were observed on PF sub-scale items about vigorous and moderate activities, lifting and carrying groceries, walking one block, and bathing or dressing. On the MH sub-scale items, all DIF effects were small or moderate in size.SF-36 PF and MH sub-scale scores were not comparable across population sub-groups defined by demographic and health status variables due to the effects of DIF, although the magnitude of this bias was not large for most items. We recommend testing and adjusting for DIF to ensure comparability of the SF-36 in population-based investigations.

  8. Tunable Multiband Microwave Photonic Filters

    Directory of Open Access Journals (Sweden)

    Mable P. Fok

    2017-11-01

    Full Text Available The increasing demand for multifunctional devices, the use of cognitive wireless technology to solve the frequency resource shortage problem, as well as the capabilities and operational flexibility necessary to meet ever-changing environment result in an urgent need of multiband wireless communications. Spectral filter is an essential part of any communication systems, and in the case of multiband wireless communications, tunable multiband RF filters are required for channel selection, noise/interference removal, and RF signal processing. Unfortunately, it is difficult for RF electronics to achieve both tunable and multiband spectral filtering. Recent advancements of microwave photonics have proven itself to be a promising candidate to solve various challenges in RF electronics including spectral filtering, however, the development of multiband microwave photonic filtering still faces lots of difficulties, due to the limited scalability and tunability of existing microwave photonic schemes. In this review paper, we first discuss the challenges that were facing by multiband microwave photonic filter, then we review recent techniques that have been developed to tackle the challenge and lead to promising developments of tunable microwave photonic multiband filters. The successful design and implementation of tunable microwave photonic multiband filter facilitate the vision of dynamic multiband wireless communications and radio frequency signal processing for commercial, defense, and civilian applications.

  9. Derivative free filtering using Kalmtool

    DEFF Research Database (Denmark)

    Bayramoglu, Enis; Hansen, Søren; Ravn, Ole

    2010-01-01

    In this paper we present a toolbox enabling easy evaluation and comparison of different filtering algorithms. The toolbox is called Kalmtool 4 and is a set of MATLAB tools for state estimation of nonlinear systems. The toolbox contains functions for extended Kalman filtering as well as for DD1 fi...

  10. Sample-whitened matched filters

    DEFF Research Database (Denmark)

    Andersen, Ib

    1973-01-01

    A sample-whitened matched filter (SWMF) for a channel with intersymbol interference and additive white Gaussian noise is defined as a linear filter with the properties that its output samples are a sufficient statistic for the MAP estimation of the transmitted sequence and have uncorrelated noise...

  11. Filter-radiometer-based realization of candela and establishment of photometric scale at UME

    Science.gov (United States)

    Samedov, Farhad; Durak, Murat; Bazkır, Özcan

    2005-11-01

    The luminous intensity unit of candela was realized based on filter-radiometer, which is traceable to detector-based primary standard electrical substitution cryogenic radiometer (ESCR). In that realization the traditional Osram Wi41/G-type incandescent lamp and filter-radiometer consisting of an aperture, a V(λ) filter and a silicon photodiode based trap detector were used as light source and detection element, respectively. Measurement techniques of effective aperture area, spectral transmittance of V(λ) filter and absolute responsivity of trap detector are also presented.

  12. A Review of Passive Filters for Grid-Connected Voltage Source Converters

    DEFF Research Database (Denmark)

    Beres, Remus Narcis; Wang, Xiongfei; Blaabjerg, Frede

    2014-01-01

    LCL filter is the common interface between the Pulse Width Modulated Voltage Source Converter (PWM VSC) and the utility grid due to high harmonic attenuation capability and reduced size of the passive elements. The present paper investigates the most promising passive damping methods for the LCL...... of the filter also is decreased. Thus, a comparison of the filter features including the robustness towards grid impedance variation, harmonic attenuation capability and losses in the damping circuit became interesting from a practical implementation point of view. The design of the proposed filters...

  13. Comparative analysis of the selective resonant LCL and LCL plus trap filters

    DEFF Research Database (Denmark)

    Beres, Remus Narcis; Wang, Xiongfei; Blaabjerg, Frede

    2014-01-01

    is to minimize the damping losses by bypassing the resistor at the fundamental and switching frequencies while preserving high attenuation at higher frequencies. A new design procedure is proposed for the selective resonant LCL filter. The presence of multi-tuned traps in the second topology aims to decrease...... the total size of the filter reactive elements while meeting current harmonic standards. It is found that selective resonant LCL filter provide much lower damping losses compared to the LCL filter with simple resistor topology. Additionally, for the trap topology a minimum switching frequency is determined...

  14. Mercury Oxidation via Catalytic Barrier Filters Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Wayne Seames; Michael Mann; Darrin Muggli; Jason Hrdlicka; Carol Horabik

    2007-09-30

    In 2004, the Department of Energy National Energy Technology Laboratory awarded the University of North Dakota a Phase II University Coal Research grant to explore the feasibility of using barrier filters coated with a catalyst to oxidize elemental mercury in coal combustion flue gas streams. Oxidized mercury is substantially easier to remove than elemental mercury. If successful, this technique has the potential to substantially reduce mercury control costs for those installations that already utilize baghouse barrier filters for particulate removal. Completed in 2004, Phase I of this project successfully met its objectives of screening and assessing the possible feasibility of using catalyst coated barrier filters for the oxidation of vapor phase elemental mercury in coal combustion generated flue gas streams. Completed in September 2007, Phase II of this project successfully met its three objectives. First, an effective coating method for a catalytic barrier filter was found. Second, the effects of a simulated flue gas on the catalysts in a bench-scale reactor were determined. Finally, the performance of the best catalyst was assessed using real flue gas generated by a 19 kW research combustor firing each of three separate coal types.

  15. Integrated photonic filters based on SiC multilayer structures

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, M.A., E-mail: mv@isel.ipl.pt [Electronics Telecommunication and Computer Dept. ISEL, R. Conselheiro Emídio Navarro, 1949-014, Lisboa (Portugal); CTS-UNINOVA, Quinta da Torre, Monte da Caparica, 2829-516, Caparica (Portugal); Vieira, M. [Electronics Telecommunication and Computer Dept. ISEL, R. Conselheiro Emídio Navarro, 1949-014, Lisboa (Portugal); CTS-UNINOVA, Quinta da Torre, Monte da Caparica, 2829-516, Caparica (Portugal); DEE-FCT-UNL, Quinta da Torre, Monte da Caparica, 2829-516, Caparica (Portugal); Louro, P.; Silva, V.; Fantoni, A. [Electronics Telecommunication and Computer Dept. ISEL, R. Conselheiro Emídio Navarro, 1949-014, Lisboa (Portugal); CTS-UNINOVA, Quinta da Torre, Monte da Caparica, 2829-516, Caparica (Portugal)

    2013-06-15

    Combined tunable WDM converters based on SiC multilayer photonic active filters are analyzed. The operation combines the properties of active long-pass and short-pass wavelength filter sections into a capacitive active band-pass filter. The sensor element is a multilayered heterostructure produced by PE-CVD. The configuration includes two stacked SiC p–i–n structures sandwiched between two transparent contacts. Transfer function characteristics are studied both theoretically and experimentally. Results show that optical bias activated photonic device combines the demultiplexing operation with the simultaneous photodetection and self amplification of an optical signal acting the device as an integrated photonic filter in the visible range. Depending on the wavelength of the external background and irradiation side, the device acts either as a short- or a long-pass band filter or as a band-stop filter. The output waveform presents a nonlinear amplitude-dependent response to the wavelengths of the input channels. A numerical simulation and a two building-blocks active circuit are presented and give insight into the physics of the device.

  16. Examining the Role of Predictor Variables of Mental Health and Personality Subscales in Internet Addiction of Students in Medical and non-Medical Universities of Sanandaj in 2014

    Directory of Open Access Journals (Sweden)

    Afshin Salahian

    2015-12-01

    Full Text Available Background and objective: According to the high and increasing prevalence of internet addiction, and the fact that little research has been done on the predictors of internet addiction in Iran, the purpose of this study was to examine the role of predictor variables of mental health and personality subscales in internet addiction of students in medical and non-medical universities of Sanandaj in 2014. Methods: The Method of this research was correlation and the statistical population were all of medical and non-medical students of Sanandaj Universities in 2014. In this study, 250 students (125 female and 125 male, were randomly selected, and completed the checklist of mental health symptoms, NEO personality questionnaire, and internet addiction questionnaire. Data were analyzed using Pearson Correlation, stepwise regression, and T test by SPSS software version 20. Results: The results indicated that obsession-compulsion, openness, consciousness, aggression and somatization subscales had predictor roles in internet addiction, and totally 51 percent of variances predicted the internet addiction (F=29.97; P=0.001. Conclusion: The internet addiction of university students is dependent upon their mental health and personality, and one can predict the internet addiction of students via subscales of mental health and personality.

  17. Advanced Filtering Techniques Applied to Spaceflight Project

    Data.gov (United States)

    National Aeronautics and Space Administration — IST-Rolla developed two nonlinear filters for spacecraft orbit determination during the Phase I contract. The theta-D filter and the cost based filter, CBF, were...

  18. [Baseline drift of electrocardiograph dealt with mathematical morphology filter in real-time].

    Science.gov (United States)

    Zhu, Xianglin; Yang, Jianning; Tang, Ping; Ling, Xin

    2010-02-01

    We have done a research on mathematical morphology filter in order to eliminate baseline drift in the wave of electrocardiograph (ECG). Marago morphology filter type was chosen and flat structuring element filtering was found to be the best morphology filter modality for eliminating baseline drift, and the ratio of "signal numerical frequency to length of structuring element" determined the attenuation magnitude of the signal eliminated. We have come to the conclusion that the length of flat structuring element ought to be greater than or equal to the width of the signal component to be eliminated. The arithmetical algorithm was simulated with Matlab software, and was transplanted to DSP hardware platform. The result of experiment has shown that the arithmetic operation is simple and the method spends a short time (less than 1 ms) in eliminating the baseline drift of ECG effectively and instantly.

  19. Face Recognition using Gabor Filters

    Directory of Open Access Journals (Sweden)

    Sajjad MOHSIN

    2011-01-01

    Full Text Available An Elastic Bunch Graph Map (EBGM algorithm is being proposed in this research paper that successfully implements face recognition using Gabor filters. The proposed system applies 40 different Gabor filters on an image. As aresult of which 40 images with different angles and orientation are received. Next, maximum intensity points in each filtered image are calculated and mark them as Fiducial points. The system reduces these points in accordance to distance between them. The next step is calculating the distances between the reduced points using distance formula. At last, the distances are compared with database. If match occurs, it means that the image is recognized.

  20. Pragmatic circuits signals and filters

    CERN Document Server

    Eccles, William

    2006-01-01

    Pragmatic Circuits: Signals and Filters is built around the processing of signals. Topics include spectra, a short introduction to the Fourier series, design of filters, and the properties of the Fourier transform. The focus is on signals rather than power. But the treatment is still pragmatic. For example, the author accepts the work of Butterworth and uses his results to design filters in a fairly methodical fashion. This third of three volumes finishes with a look at spectra by showing how to get a spectrum even if a signal is not periodic. The Fourier transform provides a way of dealing wi

  1. Simplified design of filter circuits

    CERN Document Server

    Lenk, John

    1999-01-01

    Simplified Design of Filter Circuits, the eighth book in this popular series, is a step-by-step guide to designing filters using off-the-shelf ICs. The book starts with the basic operating principles of filters and common applications, then moves on to describe how to design circuits by using and modifying chips available on the market today. Lenk's emphasis is on practical, simplified approaches to solving design problems.Contains practical designs using off-the-shelf ICsStraightforward, no-nonsense approachHighly illustrated with manufacturer's data sheets

  2. Domestic sewage and secondary effluent treatment using vertical submerged biological filter

    Science.gov (United States)

    Yang, X. J.; Tong, Y. M.; Song, Y.; Qi, W. K.; Li, Y. Y.; Guo, Y. L.

    2017-08-01

    Biological filter (bio-filter) exhibits a high potential for sustainability because construction and maintenance cost are low. When bio-filters are used as pre-treatment or post-treatment technology, other treat steps in the combined treat process could prevent clogging and get better process stability and performance efficiency. This study considered bio-filters for reducing the amounts of various wastewaters, i.e., high-strength sewage, municipal wastewater and secondary effluent water, using five kinds of media. The results obtained indicate significant improvement in organics removal when influent COD are 1500 mg/L and 2500 mg/L for anaerobic and aerobic biofilters, respectively. Sufficient alkalinity would obviously improve the substrate removal in an anaerobic bio-filter, when treating high-strength wastewater. The performances of bio-filters are adequate for further removal of the residual organic material and nutrient elements for tertiary domestic wastewater treatment.

  3. Filters in topology optimization based on Helmholtz‐type differential equations

    DEFF Research Database (Denmark)

    Lazarov, Boyan Stefanov; Sigmund, Ole

    2011-01-01

    The aim of this paper is to apply a Helmholtz‐type partial differential equation as an alternative to standard density filtering in topology optimization problems. Previously, this approach has been successfully applied as a sensitivity filter. The usual filtering techniques in topology...... from the neighbor subdomains is an expensive operation. The proposed filter technique requires only mesh information necessary for the finite element discretization of the problem. The main idea is to define the filtered variable implicitly as a solution of a Helmholtz‐type differential equation...... with homogeneous Neumann boundary conditions. The properties of the filter are demonstrated for various 2D and 3D topology optimization problems in linear elasticity, solved on serial and parallel computers. Copyright © 2010 John Wiley & Sons, Ltd....

  4. A Gaussian mixture ensemble transform filter

    OpenAIRE

    Reich, Sebastian

    2011-01-01

    We generalize the popular ensemble Kalman filter to an ensemble transform filter where the prior distribution can take the form of a Gaussian mixture or a Gaussian kernel density estimator. The design of the filter is based on a continuous formulation of the Bayesian filter analysis step. We call the new filter algorithm the ensemble Gaussian mixture filter (EGMF). The EGMF is implemented for three simple test problems (Brownian dynamics in one dimension, Langevin dynamics in two dimensions, ...

  5. Monolithic integrated switched-capacitor filters. I

    Science.gov (United States)

    Rienecker, W.

    1980-06-01

    The historical background of switched-capacitor filters is reviewed, and advanced design techniques for such filters are considered with reference to filter implementation in integrated systems. It is shown that basic equivalences between the components of time-invariant and time-variant networks make it possible to construct switched-capacitor filters that imitate classic filter types. Some examples of commercial switched-capacitor filters show the advantages of this technology.

  6. MATLAB Based Digital IIR Filter Design

    OpenAIRE

    Samarjeet Singh; Uma Sharma

    2012-01-01

    a fundamental aspect of signal processing is filtering. Filtering involves the manipulation of the spectrum of a signal by passing or blocking certain portions of the spectrum, depending on the frequency of those portions. In this paper, Digital filters are designed using frequency specifications. Matlab provides different options for digital filter design, which includes function, calls to filter algorithms and a graphical user interface called Sptool. A variety of filter design algorithms ...

  7. Respiratory-Induced Haemodynamic Changes: A Contributing Factor to IVC Filter Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Laborda, Alicia, E-mail: alaborda@unizar.es [Universidad de Zaragoza, Minimally Invasive Techniques Research Group (GITMI) (Spain); Kuo, William T., E-mail: wkuo@stanford.edu [Stanford University Medical Center, Division of Vascular and Interventional Radiology (United States); Ioakeim, Ignatios, E-mail: ignacio.ioakim@hotmail.es [Universidad de Zaragoza, Minimally Invasive Techniques Research Group (GITMI) (Spain); De Blas, Ignacio, E-mail: deblas@unizar.es [Universidad de Zaragoza, Unit of Infectious Diseases and Epidemiology, Department of Animal Pathology (Spain); Malvè, Mauro, E-mail: mauro.malve@unavarra.es [Universidad Pública de Navarra, Department of Mechanical, Energy and Materials Engineering (Spain); Lahuerta, Celia, E-mail: celialahuerta@gmail.com; De Gregorio, Miguel A., E-mail: mgregori@unizar.es [Universidad de Zaragoza, Minimally Invasive Techniques Research Group (GITMI) (Spain)

    2015-10-15

    PurposeThe purpose of the study is to evaluate the influence of respiratory-induced vena caval hemodynamic changes on filter migration/penetration.Materials and MethodsAfter placement of either a Gunther Tulip or Celect IVC filter, 101 consecutive patients scheduled for filter retrieval were prospectively enrolled in this study. Pre-retrieval CT scans were used to assess filter complications and to calculate cross-sectional area in three locations: at level of filter strut fixation, 3 cm above and 3 cm below. A 3D finite element simulation was constructed on these data and direct IVC pressure was recorded during filter retrieval. Cross-sectional areas and pressures of the vena cava were measured during neutral breathing and in Valsalva maneuver and identified filter complications were recorded. A statistical analysis of these variables was then performed.ResultsDuring Valsalva maneuvers, a 60 % decrease of the IVC cross-sectional area and a fivefold increase in the IVC pressure were identified (p < 0.001). There was a statistically significant difference in the reduction of the cross-sectional area at the filter strut level (p < 0.001) in patient with filter penetration. Difficulty in filter retrieval was higher in penetrated or tilted filters (p < 0.001; p = 0.005). 3D computational models showed significant IVC deformation around the filter during Valsalva maneuver.ConclusionCaval morphology and hemodynamics are clearly affected by Valsalva maneuvers. A physiological reduction of IVC cross-sectional area is associated with higher risk of filter penetration, despite short dwell times. Physiologic data should be used to improve future filter designs to remain safely implanted over longer dwell times.

  8. Kalman Filter Estimation of Spinning Spacecraft Attitude using Markley Variables

    Science.gov (United States)

    Sedlak, Joseph E.; Harman, Richard

    2004-01-01

    There are several different ways to represent spacecraft attitude and its time rate of change. For spinning or momentum-biased spacecraft, one particular representation has been put forward as a superior parameterization for numerical integration. Markley has demonstrated that these new variables have fewer rapidly varying elements for spinning spacecraft than other commonly used representations and provide advantages when integrating the equations of motion. The current work demonstrates how a Kalman filter can be devised to estimate the attitude using these new variables. The seven Markley variables are subject to one constraint condition, making the error covariance matrix singular. The filter design presented here explicitly accounts for this constraint by using a six-component error state in the filter update step. The reduced dimension error state is unconstrained and its covariance matrix is nonsingular.

  9. Two Integrator Loop Filters: Generation Using NAM Expansion and Review

    Directory of Open Access Journals (Sweden)

    Ahmed M. Soliman

    2010-01-01

    Full Text Available Systematic synthesis method to generate a family of two integrator loop filters based on nodal admittance matrix (NAM expansion is given. Eight equivalent circuits are obtained; six of them are new. Each of the generated circuits uses two grounded capacitors and employs two current conveyors (CCII or two inverting current conveyors (ICCII or a combination of both. The NAM expansion is also used to generate eight equivalent grounded passive elements two integrator loop filters using differential voltage current conveyor (DVCC; six of them are new. Changing the input port of excitation, two new families of eight unity gain lowpass filter circuits each using two CCII or ICCII or combination of both or two DVCC are obtained.

  10. Matched Spectral Filter Imager Project

    Data.gov (United States)

    National Aeronautics and Space Administration — OPTRA proposes the development of an imaging spectrometer for greenhouse gas and volcanic gas imaging based on matched spectral filtering and compressive imaging....

  11. Buffers and vegetative filter strips

    Science.gov (United States)

    Matthew J. Helmers; Thomas M. Isenhart; Michael G. Dosskey; Seth M. Dabney

    2008-01-01

    This chapter describes the use of buffers and vegetative filter strips relative to water quality. In particular, we primarily discuss the herbaceous components of the following NRCS Conservation Practice Standards.

  12. Integrated Spatial Filter Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To address the NASA Earth Science Division need for spatial filter arrays for amplitude and wavefront control, Luminit proposes to develop a novel Integrated Spatial...

  13. Filter-extruded liposomes revisited

    DEFF Research Database (Denmark)

    Hinna, Askell; Steiniger, Frank; Hupfeld, Stefan

    2016-01-01

    (pore-size, number of filter passages, and flow-rate), flow field-flow fractionation in conjunction with multi-angle laser light scattering (AF4-MALLS, Wyatt Technology Corp., Santa Barbara, CA) was employed. Liposome size-distributions determined by AF4-MALLS were compared with those of dynamic light...... scattering and correlated with cryo-transmission electron microscopy and 31P-NMR-analysis of lamellarity. Both the mean size of liposome and the width of size distribution were found to decrease with sequential extrusion through smaller pore size filters, starting at a size range of &70–415nm upon repeated...... extrusion through 400nm pore-filters, eventually ending with a size range from &30 to 85nm upon extrusion through 30nm pore size filters. While for small pores sizes (50 nm), increased flow rates resulted in smaller vesicles, no significant influence of flow rate on mean vesicle size was seen with larger...

  14. Adaptive optical filtering techniques

    Science.gov (United States)

    Psaltis, D.

    1985-05-01

    The purpose of this study was to examine the potential of using optical information processing technology for adaptive antenna beamforming and null steering. The adaptive beamforming/null steering problem consists of estimation of the covariance matrix of the noise field and inversion of the covariance matrix to obtain the antenna element weights which optimize the antenna's directional characteristics (gain pattern). This report examines the adaptive beamforming/nulling problem in view of the capabilities of optics and identifies areas where optics can be used to benefit. Benefits and drawbacks of various optical implementations of open and closed loop adaptive algorithms are discussed as well as the issues involved with optically processing digital binary numbers.

  15. Aquatic Plants Aid Sewage Filter

    Science.gov (United States)

    Wolverton, B. C.

    1985-01-01

    Method of wastewater treatment combines micro-organisms and aquatic plant roots in filter bed. Treatment occurs as liquid flows up through system. Micro-organisms, attached themselves to rocky base material of filter, act in several steps to decompose organic matter in wastewater. Vascular aquatic plants (typically, reeds, rushes, cattails, or water hyacinths) absorb nitrogen, phosphorus, other nutrients, and heavy metals from water through finely divided roots.

  16. Current Conveyor Based Multifunction Filter

    OpenAIRE

    Manish Kumar; Srivastava, M. C.; Umesh Kumar

    2010-01-01

    The paper presents a current conveyor based multifunction filter. The proposed circuit can be realized as low pass, high pass, band pass and elliptical notch filter. The circuit employs two balanced output current conveyors, four resistors and two grounded capacitors, ideal for integration. It has only one output terminal and the number of input terminals may be used. Further, there is no requirement for component matching in the circuit. The parameter resonance frequency (\\omega_0) and bandw...

  17. Stochastic processes and filtering theory

    CERN Document Server

    Jazwinski, Andrew H

    1970-01-01

    This unified treatment of linear and nonlinear filtering theory presents material previously available only in journals, and in terms accessible to engineering students. Its sole prerequisites are advanced calculus, the theory of ordinary differential equations, and matrix analysis. Although theory is emphasized, the text discusses numerous practical applications as well.Taking the state-space approach to filtering, this text models dynamical systems by finite-dimensional Markov processes, outputs of stochastic difference, and differential equations. Starting with background material on probab

  18. Filter Fabrics for Airport Drainage.

    Science.gov (United States)

    1979-09-01

    pneumatically filling a woven polypropylene stocking with sand and vibrating it into a prebored hole, while another method uses a polyester nonwoven fabric...Selected Nonwoven Filter Fabrics," Letter Report, June 1977, U. S. Army Engineer Waterways Experiment Station, CE, Vicksburg, Miss. 18. BalL, J. E...woven and nonwoven plastic filter fabric. It has been developed based on limited field performance observations and the laboratory test evaluation of

  19. Blind Identification of Graph Filters

    Science.gov (United States)

    Segarra, Santiago; Mateos, Gonzalo; Marques, Antonio G.; Ribeiro, Alejandro

    2017-03-01

    Network processes are often represented as signals defined on the vertices of a graph. To untangle the latent structure of such signals, one can view them as outputs of linear graph filters modeling underlying network dynamics. This paper deals with the problem of joint identification of a graph filter and its input signal, thus broadening the scope of classical blind deconvolution of temporal and spatial signals to the less-structured graph domain. Given a graph signal $\\mathbf{y}$ modeled as the output of a graph filter, the goal is to recover the vector of filter coefficients $\\mathbf{h}$, and the input signal $\\mathbf{x}$ which is assumed to be sparse. While $\\mathbf{y}$ is a bilinear function of $\\mathbf{x}$ and $\\mathbf{h}$, the filtered graph signal is also a linear combination of the entries of the lifted rank-one, row-sparse matrix $\\mathbf{x} \\mathbf{h}^T$. The blind graph-filter identification problem can thus be tackled via rank and sparsity minimization subject to linear constraints, an inverse problem amenable to convex relaxations offering provable recovery guarantees under simplifying assumptions. Numerical tests using both synthetic and real-world networks illustrate the merits of the proposed algorithms, as well as the benefits of leveraging multiple signals to aid the blind identification task.

  20. A quantum extended Kalman filter

    Science.gov (United States)

    Emzir, Muhammad F.; Woolley, Matthew J.; Petersen, Ian R.

    2017-06-01

    In quantum physics, a stochastic master equation (SME) estimates the state (density operator) of a quantum system in the Schrödinger picture based on a record of measurements made on the system. In the Heisenberg picture, the SME is a quantum filter. For a linear quantum system subject to linear measurements and Gaussian noise, the dynamics may be described by quantum stochastic differential equations (QSDEs), also known as quantum Langevin equations, and the quantum filter reduces to a so-called quantum Kalman filter. In this article, we introduce a quantum extended Kalman filter (quantum EKF), which applies a commutative approximation and a time-varying linearization to systems of nonlinear QSDEs. We will show that there are conditions under which a filter similar to a classical EKF can be implemented for quantum systems. The boundedness of estimation errors and the filtering problem with ‘state-dependent’ covariances for process and measurement noises are also discussed. We demonstrate the effectiveness of the quantum EKF by applying it to systems that involve multiple modes, nonlinear Hamiltonians, and simultaneous jump-diffusive measurements.

  1. An analytical filter design method for guided wave phased arrays

    Science.gov (United States)

    Kwon, Hyu-Sang; Kim, Jin-Yeon

    2016-12-01

    This paper presents an analytical method for designing a spatial filter that processes the data from an array of two-dimensional guided wave transducers. An inverse problem is defined where the spatial filter coefficients are determined in such a way that a prescribed beam shape, i.e., a desired array output is best approximated in the least-squares sense. Taking advantage of the 2π-periodicity of the generated wave field, Fourier-series representation is used to derive closed-form expressions for the constituting matrix elements. Special cases in which the desired array output is an ideal delta function and a gate function are considered in a more explicit way. Numerical simulations are performed to examine the performance of the filters designed by the proposed method. It is shown that the proposed filters can significantly improve the beam quality in general. Most notable is that the proposed method does not compromise between the main lobe width and the sidelobe levels; i.e. a narrow main lobe and low sidelobes are simultaneously achieved. It is also shown that the proposed filter can compensate the effects of nonuniform directivity and sensitivity of array elements by explicitly taking these into account in the formulation. From an example of detecting two separate targets, how much the angular resolution can be improved as compared to the conventional delay-and-sum filter is quantitatively illustrated. Lamb wave based imaging of localized defects in an elastic plate using a circular array is also presented as an example of practical applications.

  2. Dislocation filtering in GaN nanostructures.

    Science.gov (United States)

    Colby, Robert; Liang, Zhiwen; Wildeson, Isaac H; Ewoldt, David A; Sands, Timothy D; García, R Edwin; Stach, Eric A

    2010-05-12

    Dislocation filtering in GaN by selective area growth through a nanoporous template is examined both by transmission electron microscopy and numerical modeling. These nanorods grow epitaxially from the (0001)-oriented GaN underlayer through the approximately 100 nm thick template and naturally terminate with hexagonal pyramid-shaped caps. It is demonstrated that for a certain window of geometric parameters a threading dislocation growing within a GaN nanorod is likely to be excluded by the strong image forces of the nearby free surfaces. Approximately 3000 nanorods were examined in cross-section, including growth through 50 and 80 nm diameter pores. The very few threading dislocations not filtered by the template turn toward a free surface within the nanorod, exiting less than 50 nm past the base of the template. The potential active region for light-emitting diode devices based on these nanorods would have been entirely free of threading dislocations for all samples examined. A greater than 2 orders of magnitude reduction in threading dislocation density can be surmised from a data set of this size. A finite element-based implementation of the eigenstrain model was employed to corroborate the experimentally observed data and examine a larger range of potential nanorod geometries, providing a simple map of the different regimes of dislocation filtering for this class of GaN nanorods. These results indicate that nanostructured semiconductor materials are effective at eliminating deleterious extended defects, as necessary to enhance the optoelectronic performance and device lifetimes compared to conventional planar heterostructures.

  3. On a multiscale approach for filter efficiency simulations

    KAUST Repository

    Iliev, Oleg

    2014-07-01

    Filtration in general, and the dead end depth filtration of solid particles out of fluid in particular, is intrinsic multiscale problem. The deposition (capturing of particles) essentially depends on local velocity, on microgeometry (pore scale geometry) of the filtering medium and on the diameter distribution of the particles. The deposited (captured) particles change the microstructure of the porous media what leads to change of permeability. The changed permeability directly influences the velocity field and pressure distribution inside the filter element. To close the loop, we mention that the velocity influences the transport and deposition of particles. In certain cases one can evaluate the filtration efficiency considering only microscale or only macroscale models, but in general an accurate prediction of the filtration efficiency requires multiscale models and algorithms. This paper discusses the single scale and the multiscale models, and presents a fractional time step discretization algorithm for the multiscale problem. The velocity within the filter element is computed at macroscale, and is used as input for the solution of microscale problems at selected locations of the porous medium. The microscale problem is solved with respect to transport and capturing of individual particles, and its solution is postprocessed to provide permeability values for macroscale computations. Results from computational experiments with an oil filter are presented and discussed.

  4. Sensory pollution from bag-type fiberglass ventilation filters: Conventional filter compared with filters containing various amounts of activated carbon

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Fadeyi, M.O.; Clausen, Geo

    2009-01-01

    (100 g/m(2)). Each filter was weighed at the beginning of the soiling period and after 3 and 6 months of service. Additionally, up- and down-stream ozone concentrations and filter pressure drops were measured monthly. Following 6 months of service, the air downstream of each of the combination filters...... to an equivalent filter without carbon. The aim of the present study was to examine how the amount of activated carbon (AC) used in combination filters affects their ability to remove both sensory offending pollutants and ozone. A panel evaluated the air downstream of four different filters after each had...... was judged to be significantly better than the air downstream of the 6-month-old F7 filter, and was comparable to that from an unused F7 filter. Additionally, the combination filters removed more ozone from the air than the F7 filter, with their respective fractional removal efficiencies roughly scaling...

  5. Spectral and Wavefront Error Performance of WFIRST/AFTA Prototype Filters

    Science.gov (United States)

    Quijada, Manuel; Seide, Laurie; Marx, Cathy; Pasquale, Bert; McMann, Joseph; Hagopian, John; Dominguez, Margaret; Gong, Qian; Morey, Peter

    2016-01-01

    The Cycle 5 design baseline for the Wide-Field Infrared Survey Telescope Astrophysics Focused Telescope Assets (WFIRSTAFTA) instrument includes a single wide-field channel (WFC) instrument for both imaging and slit-less spectroscopy. The only routinely moving part during scientific observations for this wide-field channel is the element wheel (EW) assembly. This filter-wheel assembly will have 8 positions that will be populated with 6 bandpass filters, a blank position, and a Grism that will consist of a three-element assembly to disperse the full field with an undeviated central wavelength for galaxy redshift surveys. All filter elements in the EW assembly will be made out of fused silica substrates (110 mm diameter) that will have the appropriate bandpass coatings according to the filter designations (Z087, Y106, J129, H158, F184, W149 and Grism). This paper presents and discusses the performance (including spectral transmission and reflectedtransmitted wavefront error measurements) of a subset of bandpass filter coating prototypes that are based on the WFC instrument filter compliment. The bandpass coating prototypes that are tested in this effort correspond to the Z087, W149, and Grism filter elements. These filter coatings have been procured from three different vendors to assess the most challenging aspects in terms of the in-band throughput, out of band rejection (including the cut-on and cutoff slopes), and the impact the wavefront error distortions of these filter coatings will have on the imaging performance of the de-field channel in the WFIRSTAFTA observatory.

  6. Spectral and Wavefront Error Performance of WFIRST-AFTA Bandpass Filter Coating Prototypes

    Science.gov (United States)

    Quijada, Manuel A.; Seide, Laurie; Pasquale, Bert A.; McMann, Joseph C.; Hagopian, John G.; Dominguez, Margaret Z.; Gong, Quian; Marx, Catherine T.

    2016-01-01

    The Cycle 5 design baseline for the Wide-Field Infrared Survey Telescope Astrophysics Focused Telescope Assets (WFIRST/AFTA) instrument includes a single wide-field channel (WFC) instrument for both imaging and slit-less spectroscopy. The only routinely moving part during scientific observations for this wide-field channel is the element wheel (EW) assembly. This filter-wheel assembly will have 8 positions that will be populated with 6 bandpass filters, a blank position, and a Grism that will consist of a three-element assembly to disperse the full field with an undeviated central wavelength for galaxy redshift surveys. All filter elements in the EW assembly will be made out of fused silica substrates (110 mm diameter) that will have the appropriate bandpass coatings according to the filter designations (Z087, Y106, J129, H158, F184, W149 and Grism). This paper presents and discusses the performance (including spectral transmission and reflected/transmitted wavefront error measurements) of a subset of bandpass filter coating prototypes that are based on the WFC instrument filter compliment. The bandpass coating prototypes that are tested in this effort correspond to the Z087, W149, and Grism filter elements. These filter coatings have been procured from three different vendors to assess the most challenging aspects in terms of the in-band throughput, out of band rejection (including the cut-on and cutoff slopes), and the impact the wavefront error distortions of these filter coatings will have on the imaging performance of the wide-field channel in the WFIRST/AFTA observatory.

  7. Thermal and structural analysis of a filter vessel ceramic tubesheet

    Energy Technology Data Exchange (ETDEWEB)

    Mallett, R.H. [Mallett Technology, Inc., Research Triangle Park, NC (United States); Swindeman, R.W. [Oak Ridge National Lab., TN (United States); Zievers, J.F. [Industrial Filter & Pump Mfg. Co., Cicero, IL (United States)

    1995-08-01

    A ceramic tubesheet assembly for a hot gas filter vessel is analyzed using the finite element method to determine stresses under differential pressure loading. The stresses include local concentration effects. Selection of the stress measures for evaluation of structural integrity is discussed. Specification of stress limits based upon limited data is considered. Stress results from this ongoing design analysis technology project are shown for one design concept.

  8. INVERSE FILTERING TECHNIQUES IN SPEECH ANALYSIS

    African Journals Online (AJOL)

    Dr Obe

    particular system filter being inverted and in the manner of realisation. provide a basis for the classification adopted in the paper which is as follows: (1) inverse vocal tract analogue filtering. (2) inverse vocal tract digital filtering. (3) direct inverse glottal filtering. (4) linear predictive coding. An assessment of the comparative ...

  9. Water washable stainless steel HEPA filter

    Science.gov (United States)

    Phillips, Terrance D.

    2001-01-01

    The invention is a high efficiency particulate (HEPA) filter apparatus and system, and method for assaying particulates. The HEPA filter provides for capture of 99.99% or greater of particulates from a gas stream, with collection of particulates on the surface of the filter media. The invention provides a filter system that can be cleaned and regenerated in situ.

  10. An Item Response Analysis of the Motor and Behavioral Subscales of the Unified Huntington's Disease Rating Scale in Huntington Disease Gene Expansion Carriers

    Science.gov (United States)

    Vaccarino, Anthony L.; Anderson, Karen; Borowsky, Beth; Duff, Kevin; Giuliano, Joseph; Guttman, Mark; Ho, Aileen K.; Orth, Michael; Paulsen, Jane S.; Sills, Terrence; van Kammen, Daniel P.; Evans, Kenneth R.

    2011-01-01

    Although the Unified Huntington's Disease Rating Scale (UHDRS) is widely used in the assessment of Huntington disease (HD), the ability of individual items to discriminate individual differences in motor or behavioral manifestations has not been extensively studied in HD gene expansion carriers without a motor-defined clinical diagnosis (i.e., prodromal-HD or prHD). To elucidate the relationship between scores on individual motor and behavioral UHDRS items and total score for each subscale, a non-parametric item response analysis was performed on retrospective data from two multicentre, longitudinal studies. Motor and Behavioral assessments were supplied for 737 prHD individuals with data from 2114 visits (PREDICT-HD) and 686 HD individuals with data from 1482 visits (REGISTRY). Option characteristic curves were generated for UHDRS subscale items in relation to their subscale score. In prHD, overall severity of motor signs was low and participants had scores of 2 or above on very few items. In HD, motor items that assessed ocular pursuit, saccade initiation, finger tapping, tandem walking, and to a lesser extent saccade velocity, dysarthia, tongue protrusion, pronation/supination, Luria, bradykinesia, choreas, gait and balance on the retropulsion test were found to discriminate individual differences across a broad range of motor severity. In prHD, depressed mood, anxiety, and irritable behavior demonstrated good discriminative properties. In HD, depressed mood demonstrated a good relationship with the overall behavioral score. These data suggest that at least some UHDRS items appear to have utility across a broad range of severity, although many items demonstrate problematic features. PMID:21370269

  11. Self-Harm Subscale of the Schedule for Nonadaptive and Adaptive Personality (SNAP): Predicting Suicide Attempts Over 8 Years of Follow-Up

    Science.gov (United States)

    Yen, Shirley; Shea, M. Tracie; Walsh, Zach; Edelen, Maria O.; Hopwood, Christopher J.; Markowitz, John C.; Ansell, Emily B.; Morey, Leslie C.; Grilo, Carlos M.; Sanislow, Charles A.; Skodol, Andrew E.; Gunderson, John G.; Zanarini, Mary C.; McGlashan, Thomas H.

    2013-01-01

    Objective We examined the predictive power of the self-harm subscale of the Schedule for Nonadaptive and Adaptive Personality (SNAP) to identify suicide attempters in the Collaborative Longitudinal Study of Personality Disorders (CLPS). Method The SNAP, a self-report personality inventory, was administered to 733 CLPS participants at baseline, of whom 701 (96%) had at least 6 months of follow-up data. Cox proportional hazards regression analyses were performed to examine the SNAP–self-harm subscale (SNAP-SH) in predicting the 129 suicide attempters over 8 years of follow-up. Possible moderators of prediction were examined, including borderline personality disorder, major depressive disorder (MDD), and substance use disorder. We also compared baseline administration of the SNAP-SH to subsequent administrations more proximal to the suicide attempt, and to a higher-order SNAP-negative temperament (SNAP-NT) subscale. Receiver operating characteristic analyses were conducted using suicide attempts (n = 58) over the first year of follow-up to provide reference points for sensitivity and specificity. Results The SNAP-SH demonstrated good predictive power for suicide attempts (hazard ratio = 1.28, P < .001) and appeared relatively consistent across borderline personality disorder, MDD, and substance use disorder diagnoses. Using more proximal scores did not increase predictive power. The SNAP-SH compared favorably to the predictive power of the higher-order SNAP-NT. Receiver operating characteristic analyses indicate several cutoff scores on the SNAP-SH that yield moderate to high sensitivity and specificity for predicting suicide attempts over the first year of follow-up. Conclusions The SNAP-SH may be a useful screening instrument for risk of suicide attempts in nonpsychotic psychiatric patients. PMID:21294991

  12. An experimental investigation of offshore gas turbine intake air filter performance

    Energy Technology Data Exchange (ETDEWEB)

    Brekke, Olaf

    2011-07-01

    Efficient intake air filtration is a key element for limiting fouling, erosion, and corrosion in the compressor section and hot corrosion in the host section of offshore gas turbine installations. Current intake air systems on the Norwegian Continental Shelf(NCS) are normally able to prevent serious corrosion and erosion problems in the compressor section and ensure acceptable service intervals for the hot section of the gas turbines, but compressor fouling remains a challenge. This compressor fouling occurs despite the presence of 'state-of-the-art' intake air filtration systems. The performance deterioration caused by compressor fouling increases fuels consumption and emissions and has a particularly severe economic impact when it reduces the maximum available power from the gas turbine and consequently reduces oil and gas production. The main objective of this work is to determine the performance of current intake a air filters offshore and their influence on gas turbine performance. The work is empirical, and the empirical data have been obtained from offshore installations, from tests performed on a GE J85-13 jet engine at Kjeller, Norway, and from experimental tests on filter elements in a test rig at the Norwegian University of Science and Technology (NTNU). The filter test rig vas designed and built as part of this work. The work has confirmed that considerable amounts of contaminants build ut in the compressor section of offshore gas turbine engines that sodium-based salts are the dominant component of the fouling, and the influence of the observed contamination levels on gas turbine performance has been determined. The extensive test program on different types of deteriorated filter elements from offshore service has revealed that accumulated salt and other contaminants are shed from the filters and re-entrained into the airflow on the downstream side of the filters when they are exposed to wet/humid operating conditions. The relationship

  13. Evaluation of Neuropsychiatric Function in Phenylketonuria: Psychometric Properties of the ADHD Rating Scale-IV and Adult ADHD Self-Report Scale Inattention Subscale in Phenylketonuria.

    Science.gov (United States)

    Wyrwich, Kathleen W; Auguste, Priscilla; Yu, Ren; Zhang, Charlie; Dewees, Benjamin; Winslow, Barbara; Yu, Shui; Merilainen, Markus; Prasad, Suyash

    2015-06-01

    Previous qualitative research among adults and parents of children with phenylketonuria (PKU) has identified inattention as an important psychiatric aspect of this condition. The parent-reported ADHD Rating Scale-IV (ADHD RS-IV) and the Adult ADHD Self-Report Scale (ASRS) have been validated for measuring inattention symptoms in persons with attention-deficit/hyperactivity disorder (ADHD); however, their psychometric attributes for measuring PKU-related inattention have not been established. The primary objective of this investigation was to demonstrate the reliability, validity, and responsiveness of the ADHD RS-IV and ASRS inattention symptoms subscales in a randomized controlled trial of patients with PKU aged 8 years or older. A post hoc analysis investigated the psychometric properties (Rasch model fit, reliability, construct validity, and responsiveness) of the ADHD RS-IV and ASRS inattention subscales using data from a phase 3b, double-blind, placebo-controlled clinical trial in those with PKU aged 8 years or older. The Rasch results revealed good model fit, and reliability analyses revealed strong internal consistency reliability (α ≥ 0.87) and reproducibility (intraclass correlation coefficient ≥ 0.87) for both measures. Both inattention measures demonstrated the ability to discriminate between known groups (P < 0.001) created by the Clinical Global Impression-Severity scale. Correlations between the ADHD RS-IV and the ASRS with the Clinical Global Impression-Severity scale and the age-appropriate Behavior Rating Inventory of Executive Function Working Memory subscale were consistently moderate to strong (r ≥ 0.56). Similarly, results of the change score correlations were of moderate magnitude (r ≥ 0.43) for both measures when compared with changes over time in Behavior Rating Inventory of Executive Function Working Memory subscales. These findings of reliability, validity, and responsiveness of both the ADHD RS-IV and the ASRS inattention scales

  14. Possibility of applying memristors in microwave filters

    Directory of Open Access Journals (Sweden)

    Marković Ivo Lj.

    2016-01-01

    Full Text Available This paper discusses the possibility of applying memristors in microwave passive circuits such as filters. Basic information about memristor like theoretical assumptions, realisation, structure, and physical properties of the component are presented. We analyze behavior of two microwave filters: end-coupled bandpass filter and hairpin filter. They are both bandpass filters, where the end-coupled filter is designed to operate at the center frequency of 6 GHz, and the hairpin filter is designed at the center frequency of 1 GHz. We analyze these filters with LTspice. The filters are realized in two ways, namely when using resistors, and when using memristors. Ideal memristors are used, and idealized circuits are analyzed in order to confirm functionality of implementations. The results show that the application is possible, without losing the quality of the filter characteristics.

  15. Uncertainty quantification of acoustic emission filtering techniques

    Science.gov (United States)

    Zárate, Boris A.; Caicedo, Juan M.; Ziehl, Paul

    2012-04-01

    This paper compares six different filtering protocols used in Acoustic Emission (AE) monitoring of fatigue crack growth. The filtering protocols are combination of three different filtering techniques which are based on Swansong-like filters and load filters. The filters are compared deterministically and probabilistically. The deterministic comparison is based on the coefficient of determination of the resulting AE data, while the probabilistic comparison is based on the quantification of the uncertainty of the different filtering protocols. The uncertainty of the filtering protocols is quantified by calculating the entropy of the probability distribution of some AE and fracture mechanics parameters for the given filtering protocol. The methodology is useful in cases where several filtering protocols are available and there is no reason to choose one over the others. Acoustic Emission data from a compact tension specimen tested under cyclic load is used for the comparison.

  16. Shielded multi-stage EMI noise filter

    Science.gov (United States)

    Kisner, Roger Allen; Fugate, David Lee

    2016-11-08

    Electromagnetic interference (EMI) noise filter embodiments and methods for filtering are provided herein. EMI noise filters include multiple signal exclusion enclosures. The multiple signal exclusion enclosures contain filter circuit stages. The signal exclusion enclosures can attenuate noise generated external to the enclosures and/or isolate noise currents generated by the corresponding filter circuits within the enclosures. In certain embodiments, an output of one filter circuit stage is connected to an input of the next filter circuit stage. The multiple signal exclusion enclosures can be chambers formed using conductive partitions to divide an outer signal exclusion enclosure. EMI noise filters can also include mechanisms to maintain the components of the filter circuit stages at a consistent temperature. For example, a metal base plate can distribute heat among filter components, and an insulating material can be positioned inside signal exclusion enclosures.

  17. Spectral filtering for plant production

    Energy Technology Data Exchange (ETDEWEB)

    Young, R.E.; McMahon, M.J.; Rajapakse, N.C.; Becoteau, D.R.

    1994-12-31

    Research to date suggests that spectral filtering can be an effective alternative to chemical growth regulators for altering plant development. If properly implemented, it can be nonchemical and environmentally friendly. The aqueous CuSO{sub 4}, and CuCl{sub 2} solutions in channelled plastic panels have been shown to be effective filters, but they can be highly toxic if the solutions contact plants. Some studies suggest that spectral filtration limited to short EOD intervals can also alter plant development. Future research should be directed toward confirmation of the influence of spectral filters and exposure times on a broader range of plant species and cultivars. Efforts should also be made to identify non-noxious alternatives to aqueous copper solutions and/or to incorporate these chemicals permanently into plastic films and panels that can be used in greenhouse construction. It would also be informative to study the impacts of spectral filters on insect and microbal populations in plant growth facilities. The economic impacts of spectral filtering techniques should be assessed for each delivery methodology.

  18. A biological oil adsorption filter

    Energy Technology Data Exchange (ETDEWEB)

    Pasila, A. [University of Helsinki (Finland). Dept. of Agricultural Engineering and Household Technology

    2005-12-01

    A new oil adsorption method called adsorption filtration (AF) has been developed. It is a technology where by oil residues can be cleaned from water by running it through a simple filter made from freeze treated, dried, milled and then fragmented plant material. By choosing suitable plants and fragmentation sizes it is possible to produce filters, which pass water but adsorb oil. The aim of this study was to investigate the possibilities of manufacturing oil adsorbing filter materials from reed canary grass (Phalaris arundinacea), flax (Linum usitatissimum L.) or hemp fibre (Cannabis sativa L.). The oil (80 ml) was mixed with de-ionised water (200 ml) and this mixture was filtered through 10 or 20 g adsorption filters. Fine spring harvested hemp fibre (diameter less than 1 mm) and reed canary grass fragments adsorb 2-4 g of oil per gram of adsorption material compared to 1-3 g of water. Adsorption filtration is thus a novel way of gathering spilled oil in shallow coastal waters before the oil reaches the shore. (author)

  19. GPU Accelerated Vector Median Filter

    Science.gov (United States)

    Aras, Rifat; Shen, Yuzhong

    2011-01-01

    Noise reduction is an important step for most image processing tasks. For three channel color images, a widely used technique is vector median filter in which color values of pixels are treated as 3-component vectors. Vector median filters are computationally expensive; for a window size of n x n, each of the n(sup 2) vectors has to be compared with other n(sup 2) - 1 vectors in distances. General purpose computation on graphics processing units (GPUs) is the paradigm of utilizing high-performance many-core GPU architectures for computation tasks that are normally handled by CPUs. In this work. NVIDIA's Compute Unified Device Architecture (CUDA) paradigm is used to accelerate vector median filtering. which has to the best of our knowledge never been done before. The performance of GPU accelerated vector median filter is compared to that of the CPU and MPI-based versions for different image and window sizes, Initial findings of the study showed 100x improvement of performance of vector median filter implementation on GPUs over CPU implementations and further speed-up is expected after more extensive optimizations of the GPU algorithm .

  20. Evaluation of the composition of filters additional of equipment radiological intraoral by energy dispersive x-ray fluorescence (EDXRF)

    Energy Technology Data Exchange (ETDEWEB)

    Franca, Alana Caroline; Torres, Catarina A.M.P.; Rocha, Ana S.S.; Deniak, Valeriy; Lara, Alessandro L.; Paschuk, Sergei A., E-mail: alanacarolinef@gmail.com, E-mail: sergei@utfpr.edu.br [Universidade Tecnologica Federal do Parana (CPGEI/UTFPR), Curitiba, PR (Brazil). Programa de Pos-Graduacao em Engenharia Eletrica e Informatica Industrial; Fernandes, Angela; Westphalen, Fernando Henrique, E-mail: angelafernandes@ufpr.br [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Setor de Ciencias da Saude

    2013-07-01

    The need for high quality standards for radiographic images in order to make a diagnosis assertive, and being the additional filtration required in the intraoral X-ray equipment show the need of evaluating these filters. This study aims to examine the influence of the elemental composition of the filters of X-ray of dental intraoral equipment in the radiographic images quality. The filters analysis were performed by using the energy dispersive X-ray fluorescence method (EDXRF). Ten conventional filters were analysed. In this study, 33 radiographic exposures were performed using films: twenty radiographs in the incisor region and ten in the molar region, three exposures were also made in the same regions with same conditions without using filter. After radiographs development, optical density was measure and all radiographs were submitted to subjective evaluation by dental radiologists. Data obtained were correlated to effects evaluation of the elemental composition of all filters in the quality of the radiographic images. The elements found were: aluminum, cobalt, copper, sulfur, iron, manganese, titanium, zinc, and zirconium. The images obtained were identified in groups: Molars to 0.3 s; Incisors to 0.2 s; Incisors to 0.3 s, and for the group without filters. From the results obtained it was concluded that both unclear radiographs and ideal radiographs were produced by using filters of elementary common. Therefore, conventional filters evaluated were an acceptable option to produce quality images in dental radiology, despite differences in the composition of the alloys. (author)

  1. A temperature-independent filter based on a surface plasmon polariton resonator

    Science.gov (United States)

    Lang, Peilin; Zong, Yan; Yu, Li; Duan, Gaoyan; Pan, Zijuan

    2017-06-01

    Both the size and the refractive index of the materials which form the optical element are influenced by the temperature. So the characteristics of a surface plasmon polariton (SPP) element are always affected by the temperature. In this paper, we show that the deformation can be used to compensate the influence of the temperature. A temperature-independent filter based on SPP resonator is presented and this method can be used to develop novel nano-optical elements in the future.

  2. Framed primal elements

    OpenAIRE

    Debongnie, Jean-François

    1986-01-01

    Framed primal finite elements may be viewed as a generalized class of elements including conforming elements, primal hybrids, and non concorming elements passing the patch test. This systematization is illustrated on a lot of examples.

  3. Sensitivity to changes during antidepressant treatment: a comparison of unidimensional subscales of the Inventory of Depressive Symptomatology (IDS-C) and the Hamilton Depression Rating Scale (HAMD) in patients with mild major, minor or subsyndromal depression.

    Science.gov (United States)

    Helmreich, Isabella; Wagner, Stefanie; Mergl, Roland; Allgaier, Antje-Kathrin; Hautzinger, Martin; Henkel, Verena; Hegerl, Ulrich; Tadić, André

    2012-06-01

    In the efficacy evaluation of antidepressant treatments, the total score of the Hamilton Depression Rating Scale (HAMD) is still regarded as the 'gold standard'. We previously had shown that the Inventory of Depressive Symptomatology (IDS) was more sensitive to detect depressive symptom changes than the HAMD17 (Helmreich et al. 2011). Furthermore, studies suggest that the unidimensional subscales of the HAMD, which capture the core depressive symptoms, outperform the full HAMD regarding the detection of antidepressant treatment effects. The aim of the present study was to compare several unidimensional subscales of the HAMD and the IDS regarding their sensitivity to changes in depression symptoms in a sample of patients with mild major, minor or subsyndromal depression (MIND). Biweekly IDS-C28 and HAMD17 data from 287 patients of a 10-week randomised, placebo-controlled trial comparing the effectiveness of sertraline and cognitive-behavioural group therapy in patients with MIND were converted to subscale scores and analysed during the antidepressant treatment course. We investigated sensitivity to depressive change for all scales from assessment-to-assessment, in relation to depression severity level and placebo-verum differences. The subscales performed similarly during the treatment course, with slight advantages for some subscales in detecting treatment effects depending on the treatment modality and on the items included. Most changes in depressive symptomatology were detected by the IDS short scale, but regarding the effect sizes, it performed worse than most subscales. Unidimensional subscales are a time- and cost-saving option in judging drug therapy outcomes, especially in antidepressant treatment efficacy studies. However, subscales do not cover all facets of depression (e.g. atypical symptoms, sleep disturbances), which might be important for comprehensively understanding the nature of the disease depression. Therefore, the cost-to-benefit ratio must be

  4. Trace Elements in River Waters

    Science.gov (United States)

    Gaillardet, J.; Viers, J.; Dupré, B.

    2003-12-01

    satisfactorily model and predict the behavior of most of the trace elements in hydrosystems?An impressive literature has dealt with experimental works on aqueous complexation, uptake of trace elements by surface complexation (inorganic and organic), uptake by living organisms (bioaccumulation) that we have not reported here, except when the results of such studies directly explain natural data. As continental waters encompass a greater range of physical and chemical conditions, we focus on river waters and do not discuss trace elements in groundwaters, lakes, and the ocean. In lakes and in the ocean, the great importance of life processes in regulating trace elements is probably the major difference from rivers.Section 5.09.2 of this chapter reports data. We will review the present-day literature on trace elements in rivers to show that our knowledge is still poor. By comparing with the continental abundances, a global mobility index is calculated for each trace element. The spatial and temporal variability of trace-element concentrations in rivers will be shown to be important. In Section 5.09.3, sources of trace elements in river waters are indicated. We will point out the great diversity of sources and the importance of global anthropogenic contamination for a number of elements. The question of inorganic and organic speciation of trace elements in river water will then be addressed in Section 5.09.4, considering some general relationships between speciation and placement in the periodic table. In Section 5.09.5, we will show that studies on organic-rich rivers have led to an exploration of the "colloidal world" in rivers. Colloids are small particles, passing through the conventional filters used to separate dissolved and suspended loads in rivers. They appear as major carriers of trace elements in rivers and considerably complicate aqueous-speciation calculation. Finally, in Section 5.09.6, the significance of interactions between solutes and solid surfaces in river waters

  5. Attitude estimation by divided difference filter in quaternion space

    Science.gov (United States)

    Ahmadi, Mohammad; Khayatian, Alireza; Karimaghaee, Paknoush

    2012-06-01

    This article considers the application of Divided Difference Filter (DDF) to the orientation estimation, based on a quaternion-error continuous-discrete time model. DDF is a nonlinear estimator that in contrast to Taylor's expansion of extended Kalman Filter (EKF), exploit the polynomial approximations as a multivariable extension of Stirling's interpolation formula and require no derivatives. The DDF can be based on 1st and 2nd order Stirling's interpolation, which is named the divided difference filter-1st order (DDF1) and the divided difference filter-2nd order (DDF2). The orientation kinematics is defined in a quaternion vector space that unlike the Euler angle representation does not have any singularity problem. The presented nonlinear orientation model is an exact error model and is independent of the rigid body dynamics. The nonlinear process model includes six error-states in which only non-scalar elements of quaternion error vector are included in the error-state equations. The fourth element of quaternion error vector, which obeys unit norm constraint, is removed from system states to alleviate the estimated error covariance matrix divergence. The measurement system is a MARG sensor, which consists of a tri-axial rate gyro, a tri-axial accelerometer and a tri-axial magnetometer. The nonlinear measurement model is obtained based on the principals of magnetometer and accelerometer and the properties of the quaternion vector space. For the presented nonlinear orientation model, the performance of three filters namely DDF, EKF and Unscented Kalman Filter (UKF) is compared for different sampling frequencies in terms of the rms error, the captured area under the error norm curve, the estimated state variance and the computational cost. It is shown that under the same initial angle-error conditions, DDFs and UKF are more robust than EKF. The DDFs perform better than unscented Kalman filter (UKF) although the computational load for UKF is less. Among DDF1 and

  6. Gaussian particle flow implementation of PHD filter

    Science.gov (United States)

    Zhao, Lingling; Wang, Junjie; Li, Yunpeng; Coates, Mark J.

    2016-05-01

    Particle filter and Gaussian mixture implementations of random finite set filters have been proposed to tackle the issue of jointly estimating the number of targets and their states. The Gaussian mixture PHD (GM-PHD) filter has a closed-form expression for the PHD for linear and Gaussian target models, and extensions using the extended Kalman filter or unscented Kalman Filter have been developed to allow the GM-PHD filter to accommodate mildly nonlinear dynamics. Errors resulting from linearization or model mismatch are unavoidable. A particle filter implementation of the PHD filter (PF-PHD) is more suitable for nonlinear and non-Gaussian target models. The particle filter implementations are much more computationally expensive and performance can suffer when the proposal distribution is not a good match to the posterior. In this paper, we propose a novel implementation of the PHD filter named the Gaussian particle flow PHD filter (GPF-PHD). It employs a bank of particle flow filters to approximate the PHD; these play the same role as the Gaussian components in the GM-PHD filter but are better suited to non-linear dynamics and measurement equations. Using the particle flow filter allows the GPF-PHD filter to migrate particles to the dense regions of the posterior, which leads to higher efficiency than the PF-PHD. We explore the performance of the new algorithm through numerical simulations.

  7. Filter Bubble vs. Preference Bubble

    OpenAIRE

    Lindström, Hanna-Stiina; Soliman, Gabriela

    2016-01-01

    Tämän opinnäytetyön aiheena oli internetin personointi ja siitä aiheutuva filter bubble –ilmiö. Tarkoituksena oli tutkia kuluttajien suhtautumista ilmiöön, jota Suomessa ei vielä tunnisteta laajasti. Suhtautuminen haluttiin tuoda esiin vastakkainasettelun avulla. Filter bubble –näkökulma edusti tässä työssä ilmiön negatiivista suhtautumistapaa ja preference bubble –näkökulma positiivista. Opinnäytetyö oli tietopaketti yrityksille Filter bubble –ilmiön ominaisuuksista sekä sen käyttäytymisestä...

  8. Design of wind shear filters

    Science.gov (United States)

    Joerck, H.

    1984-01-01

    A number of aircraft accidents are caused by the effects of wind shear. In connection with efforts to eliminate or reduce hazards leading to such accidents, the possibility was considered to improve aircraft control systems. However, the effective implementation of the considered approaches will only be possible if suitable filters can be designed for a separation of gusts, which involve higher frequencies from low-frequency wind shear components. Filters of appropriate design should be suited for an employment in connection with all flight conditions. Feasible approaches for obtaining such filters are discussed. A survey is provided regarding the order of magnitude of the improvements which can be achieved, taking into account the performance characteristics of the A300 controller.

  9. Adaptive filtering primer with Matlab

    CERN Document Server

    Poularikas, Alexander D

    2006-01-01

    INTRODUCTIONSignal ProcessingAn ExampleOutline of the TextDISCRETE-TIME SIGNAL PROCESSINGDiscrete Time SignalsTransform-Domain Representation of Discrete-Time SignalsThe Z-TransformDiscrete-Time SystemsProblemsHints-Solutions-SuggestionsRANDOM VARIABLES, SEQUENCES, AND STOCHASTIC PROCESSESRandom Signals and DistributionsAveragesStationary ProcessesSpecial Random Signals and Probability Density FunctionsWiener-Khinchin RelationsFiltering Random ProcessesSpecial Types of Random ProcessesNonparametric Spectra EstimationParametric Methods of power Spectral EstimationProblemsHints-Solutions-SuggestionsWIENER FILTERSThe Mean-Square ErrorThe FIR Wiener FilterThe Wiener SolutionWiener Filtering ExamplesProblemsHints-Solutions-SuggestionsEIGENVALUES OF RX - PROPERTIES OF THE ERROR SURFACEThe Eigenvalues of the Correlation MatrixGeometrical Properties of the Error SurfaceProblemsHints-Solutions-SuggestionsNEWTON AND STEEPEST-DESCENT METHODOne-Dimensional Gradient Search MethodSteepest-Descent AlgorithmProblemsHints-Sol...

  10. Applications of nonwoven filter media

    Energy Technology Data Exchange (ETDEWEB)

    1988-11-01

    The multi-client technical and marketing report, Nonwovens in Filtration (1987) World Wide, has been completed by Filter Media Consulting, Inc. According to this 450-page report, $818 million in sales worldwide in nonwoven filter media represents a substantial segment of the entire nonwoven market. This total is mainly roll goods with a few exceptions. Meltblown composites represent $108 million, 13% of the total, and is the fastest growing segment as compared to needled felts, dry formed, thermobonded, spunbonded, wet laid and other unique processes, all extensively covered in this report. Included are 20 filtration applications covered in 190 pages, such as baghouse and dust filtration, Torit-type cartridge filters, HEPA/ULPA filtration, and heating, ventilation and air conditioning. Major markets are addressed, and trends in different fields are highlighted throughout the report.

  11. Design and analysis of a photonic crystal fiber based polarization filter using surface plasmon resonance

    Science.gov (United States)

    Yogalakshmi, S.; Selvendran, S.; Sivanantha Raja, A.

    2016-05-01

    A photonic crystal fiber with an active metal nanowire is proposed to act as a polarization filter based on the principle of plasmonic resonance. The light launched into the silica core gets coupled to gold wire inducing surface plasmon resonance, filtering one of the two orthogonally polarized light waves in the third optical communication window. This polarization filtering characteristic is analyzed using the finite element method. The change in the performance behaviour of the proposed filter is investigated by increasing the number of embedded gold wires, altering their positions and varying the diameter of gold wire. It is found that enhanced absorption of the core guided mode is achieved by replacing the filled metal nanowire with a metal coating around the air hole. Filtering of any or both polarizations can be attained by suitably positioning the metal wires. Confinement loss as high as 348.55 and 302 dB cm-1 for y-polarized and x-polarized lights respectively are attained at 1.52 and 1.56 μm respectively for single gold wire. The filter acts as a single polarization filter filtering x-polarized light with a confinement loss value of 187.67 dB cm-1 when two gold nanowires are placed adjacently. The same structure acts as the filter for y-polarized light by employing gold coating exhibiting an increased confinement loss of 406.34 dB cm-1 at 1.64 μm.

  12. Association between somatization subscale score and serotonin transporter availability in healthy volunteers--a single photon emission computed tomography study with [¹²³I] ADAM.

    Science.gov (United States)

    Chou, Ming Hui; Chen, Kao Chin; Yeh, Tzung Lieh; Lee, I Hui; Yao, Wei Jen; Chen, Po See; Chang, Kang-Wei; Liao, Mei-Hsiu; Yang, Yen Kuang

    2012-02-01

    Serotonin is one of the key neuromodulators involved in fundamental cerebral functions and behaviors. Previous study has demonstrated that somatization symptoms are probably associated with central serotonergic circuits, which are implicated in anxiety and nociception regulation. This study aims to examine the correlation between somatization subscale score and serotonin transporter (SERT) availability in healthy volunteers. Sixty-four healthy participants, 26 males and 38 females, were enrolled from the community and were administered the single somatization subscale of the Chinese symptom checklist 90 revised (SCL90-R). Single photon emission computed tomography with [(123)I] 2-((2-((dimethylamino)methyl)phenyl)thio)-5-iodophenylamine was also performed to examine SERT availability. The somatization scores were negatively correlated with SERT availability (Spearman's ρ = -0.35, p = 0.005), particularly in males (Spearman's ρ = -0.54, p = 0.004). This result reconfirmed the correlation between central serotonergic activity and the intensity of somatization symptoms, even in healthy participants. However, a gender difference exists in this correlation.

  13. Observed Agreement Problems between Sub-Scales and Summary Components of the SF-36 Version 2 - An Alternative Scoring Method Can Correct the Problem

    Science.gov (United States)

    Tucker, Graeme; Adams, Robert; Wilson, David

    2013-01-01

    Purpose A number of previous studies have shown inconsistencies between sub-scale scores and component summary scores using traditional scoring methods of the SF-36 version 1. This study addresses the issue in Version 2 and asks if the previous problems of disagreement between the eight SF-36 Version 1 sub-scale scores and the Physical and Mental Component Summary persist in version 2. A second study objective is to review the recommended scoring methods for the creation of factor scoring weights and the effect on producing summary scale scores Methods The 2004 South Australian Health Omnibus Survey dataset was used for the production of coefficients. There were 3,014 observations with full data for the SF-36. Data were analysed in LISREL V8.71. Confirmatory factor analysis models were fit to the data producing diagonally weighted least squares estimates. Scoring coefficients were validated on an independent dataset, the 2008 South Australian Health Omnibus Survey. Results Problems of agreement were observed with the recommended orthogonal scoring methods which were corrected using confirmatory factor analysis. Conclusions Confirmatory factor analysis is the preferred method to analyse SF-36 data, allowing for the correlation between physical and mental health. PMID:23593428

  14. Examining unidimensionality and improving reliability for the eight subscales of the SF-36 in opioid-dependent patients using Rasch analysis.

    Science.gov (United States)

    Hsiao, Yu-Yu; Shih, Ching-Lin; Yu, Wan-Hui; Hsieh, Cheng-Hsi; Hsieh, Ching-Lin

    2015-02-01

    The Medical Outcome Study Short Form 36 (SF-36) is one of the most commonly used questionnaires for monitoring the Health-Related Quality of Life (HRQOL) of opioid-dependent patients. However, the unidimensionality and reliability of the SF-36 have not been verified in opioid-dependent patients. The aim of this study was to examine the unidimensionality and to improve the test reliability of the SF-36 for use in opioid-dependent patients. A total of 583 opioid-dependent patients were recruited in the study. Unidimensionality was examined by conducting unidimensional Rasch analysis. Item fit statistics and principle component analysis were used to check the item-model fit in each of the eight subscales of the SF-36. Reliability was evaluated by applying both unidimensional and multidimensional Rasch analyses. After three misfitting items were excluded, the remaining items of each subscale in the SF-36 represented a single construct. The test reliabilities (0.80-0.87) yielded by the multidimensional approach were much higher than those (0.68-0.82) produced by the unidimensional approach. The remaining 32 items of the SF-36 are appropriate for evaluating the HRQOL in opioid-dependent patients in terms of unidimensionality. Additionally, the test scores produced by the multidimensional approach were more accurate than those obtained by the unidimensional approach.

  15. Towards parsimony in habit measurement: Testing the convergent and predictive validity of an automaticity subscale of the Self-Report Habit Index

    Science.gov (United States)

    2012-01-01

    Background The twelve-item Self-Report Habit Index (SRHI) is the most popular measure of energy-balance related habits. This measure characterises habit by automatic activation, behavioural frequency, and relevance to self-identity. Previous empirical research suggests that the SRHI may be abbreviated with no losses in reliability or predictive utility. Drawing on recent theorising suggesting that automaticity is the ‘active ingredient’ of habit-behaviour relationships, we tested whether an automaticity-specific SRHI subscale could capture habit-based behaviour patterns in self-report data. Methods A content validity task was undertaken to identify a subset of automaticity indicators within the SRHI. The reliability, convergent validity and predictive validity of the automaticity item subset was subsequently tested in secondary analyses of all previous SRHI applications, identified via systematic review, and in primary analyses of four raw datasets relating to energy‐balance relevant behaviours (inactive travel, active travel, snacking, and alcohol consumption). Results A four-item automaticity subscale (the ‘Self-Report Behavioural Automaticity Index’; ‘SRBAI’) was found to be reliable and sensitive to two hypothesised effects of habit on behaviour: a habit-behaviour correlation, and a moderating effect of habit on the intention-behaviour relationship. Conclusion The SRBAI offers a parsimonious measure that adequately captures habitual behaviour patterns. The SRBAI may be of particular utility in predicting future behaviour and in studies tracking habit formation or disruption. PMID:22935297

  16. Clinical meaningfulness of Alzheimer's Disease Assessment Scale-Cognitive subscale change in relation to goal attainment in patients on cholinesterase inhibitors.

    Science.gov (United States)

    Rockwood, Kenneth; Howlett, Susan E; Hoffman, Deborah; Schindler, Rachel; Mitnitski, Arnold

    2017-10-01

    The clinical meaningfulness of Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog) subscale change is disputed. We compared 2- to 4-point ADAS-Cog changes with changes in Goal Attainment Scaling (GAS) and everyday function across initial ADAS-Cog scores and treatment responses. This exploratory analysis evaluated mild-moderate Alzheimer's disease patients treated with donepezil (12 months) or galantamine (8 months). Clinical meaningfulness was defined as concomitant ADAS-Cog and GAS changes of ±3 points and/or functional improvement. Patients with ≥3-point ADAS-Cog improvement significantly improved on GAS but not on standard tests of everyday function. ADAS-Cog "no change" (≤±3 points) was seen with mean GAS improvement. Initial ADAS-Cog improvement made endpoint improvement (ADAS-Cog 3 points and GAS 1 point) more likely (odds ratio = 6.9; 95% confidence interval = 2.5-19.5). In contrast, initial deterioration made endpoint improvement unlikely (0.33; 0.14-0.64). ADAS-Cog improvement and no change were each associated with GAS improvement. Initial ADAS-Cog worsening was unlikely to result in later improvement. ISRCTN26167328. Copyright © 2017. Published by Elsevier Inc.

  17. The brain-derived neurotrophic factor (BDNF val66met polymorphism differentially affects performance on subscales of the Wechsler memory scale – third edition (WMS-III

    Directory of Open Access Journals (Sweden)

    Yvette Nicole Lamb

    2015-08-01

    Full Text Available Single nucleotide polymorphisms in the brain-derived neurotrophic factor (BDNF gene and the catechol-O-methyltransferase (COMT gene influence brain structure and function, as well as cognitive abilities. They are most influential in the hippocampus and prefrontal cortex (PFC, respectively. Recall and recognition are forms of memory proposed to have different neural substrates, with recall having a greater dependence on the PFC and hippocampus. This study aimed to determine whether the BDNF val66met or COMT val158met polymorphisms differentially affect recall and recognition, and whether these polymorphisms interact. A sample of 100 healthy adults was assessed on recall and familiarity-based recognition using the Faces and Family Pictures subscales of the Wechsler Memory Scale – Third Edition (WMS-III. COMT genotype did not affect performance on either task. The BDNF polymorphism (i.e. met carriers relative to val homozygotes was associated with poorer recall ability, while not influencing recognition. Combining subscale scores in memory tests such as the WMS might obscure gene effects. Our results demonstrate the importance of distinguishing between recall and familiarity-based recognition in neurogenetics research.

  18. Towards parsimony in habit measurement: testing the convergent and predictive validity of an automaticity subscale of the Self-Report Habit Index.

    Science.gov (United States)

    Gardner, Benjamin; Abraham, Charles; Lally, Phillippa; de Bruijn, Gert-Jan

    2012-08-30

    The twelve-item Self-Report Habit Index (SRHI) is the most popular measure of energy-balance related habits. This measure characterises habit by automatic activation, behavioural frequency, and relevance to self-identity. Previous empirical research suggests that the SRHI may be abbreviated with no losses in reliability or predictive utility. Drawing on recent theorising suggesting that automaticity is the 'active ingredient' of habit-behaviour relationships, we tested whether an automaticity-specific SRHI subscale could capture habit-based behaviour patterns in self-report data. A content validity task was undertaken to identify a subset of automaticity indicators within the SRHI. The reliability, convergent validity and predictive validity of the automaticity item subset was subsequently tested in secondary analyses of all previous SRHI applications, identified via systematic review, and in primary analyses of four raw datasets relating to energy-balance relevant behaviours (inactive travel, active travel, snacking, and alcohol consumption). A four-item automaticity subscale (the 'Self-Report Behavioural Automaticity Index'; 'SRBAI') was found to be reliable and sensitive to two hypothesised effects of habit on behaviour: a habit-behaviour correlation, and a moderating effect of habit on the intention-behaviour relationship. The SRBAI offers a parsimonious measure that adequately captures habitual behaviour patterns. The SRBAI may be of particular utility in predicting future behaviour and in studies tracking habit formation or disruption.

  19. Adaptive filtering prediction and control

    CERN Document Server

    Goodwin, Graham C

    2009-01-01

    Preface1. Introduction to Adaptive TechniquesPart 1. Deterministic Systems2. Models for Deterministic Dynamical Systems3. Parameter Estimation for Deterministic Systems4. Deterministic Adaptive Prediction5. Control of Linear Deterministic Systems6. Adaptive Control of Linear Deterministic SystemsPart 2. Stochastic Systems7. Optimal Filtering and Prediction8. Parameter Estimation for Stochastic Dynamic Systems9. Adaptive Filtering and Prediction10. Control of Stochastic Systems11. Adaptive Control of Stochastic SystemsAppendicesA. A Brief Review of Some Results from Systems TheoryB. A Summary o

  20. Optical Filtering and Correlator Evaluation

    Science.gov (United States)

    1992-06-01

    of an SDF, called a filter SDF ( fSDF ), has been introduced that includes the function modulation characteristics of the device onto which the filter... fSDF -BPOFs, the coefficients an can be iterated based on the formula i+1 O(Ma. an+03 cn-CO, o)] S(3) where i is the iteration number, fl is a damping...experi- ments described in this paper, the initial solution vector was taken to be the desired correlation response vector, a0 = c = 1. The initial fSDF

  1. Performance of efficient digital filters

    OpenAIRE

    Agbonogieva, Osazee

    2009-01-01

    An efficient digital signal uses an 8-bit embedded processor on a DSP platform, which was developed to design the technical specifications in this final year project. The goal was to design a program that counts maximum bits time of 8, 16, 32 and 64 on a Matlab platform, specify the filter design and generate the C header as an export bit integer signed or unsigned, copy the filter coefficients to a platform called PSoC, and initialize with the coefficients generated by Matlab. The prop...

  2. Sensitivity Filters In Topology Optimisation As A Solution To Helmholtz Type Differential Equation

    DEFF Research Database (Denmark)

    Lazarov, Boyan Stefanov; Sigmund, Ole

    2009-01-01

    The focus of the study in this article is on the use of a Helmholtz type differential equation as a filter for topology optimisation problems. Until now various filtering schemes have been utilised in order to impose mesh independence in this type of problems. The usual techniques require topology...... equation with homogeneous Neumann boundary conditions. The properties of the filter are demonstrated for various 2D and 3D topology optimisation problems in linear elasticity, solved on sequential and parallel computers....... information about the neighbour sub-domains is an expensive operation. The proposed filtering technique requires only mesh information necessary for the finite element discretisation of the problem. The main idea is to define the filtered variable implicitly as a solution of a Helmholtz type differential...

  3. The effect of compression on tuning estimates in a simple nonlinear auditory filter model

    DEFF Research Database (Denmark)

    Marschall, Marton; MacDonald, Ewen; Dau, Torsten

    2013-01-01

    consists of a compressor between two bandpass filters. The BPNL forms the basis of the dual-resonance nonlinear (DRNL) filter that has been used in a number of modeling studies. The location of the nonlinear element and its effect on estimated tuning in the two measurement paradigms was investigated......, there is evidence that human frequency-selectivity estimates depend on whether an iso-input or an iso-response measurement paradigm is used (Eustaquio-Martin et al., 2011). This study presents simulated tuning estimates using a simple compressive auditory filter model, the bandpass nonlinearity (BPNL), which....... The results show that compression leads to (i) a narrower tuning estimate in the iso-response paradigm when a compressor precedes a filter, and (ii) a wider tuning estimate in the iso-input paradigm when a compressor follows a filter. The results imply that if the DRNL presents a valid cochlear model...

  4. Robust Design of LCL-Filters for Active Damping in Grid Converters

    DEFF Research Database (Denmark)

    Alzola, Rafael Pena; Liserre, Marco; Blaabjerg, Frede

    2013-01-01

    Grid converters require a simple inductor or an LCL-filter to limit the current ripples. The LCL-filter is nowadays the preferred solution as it allows lower inductance values. In order to solve the stability concerns, active damping is preferred to passive damping since it does not use dissipative...... elements. However, large variations in the grid inductance and resonances arising from parallel converters may still compromise the system stability. This calls for a robust design of LCL-filters with active damping. This paper proposes a design flow with little iteration for two well-known methods, namely...... lead-lag network and current capacitor feedback. The proposed formulas for the resonance frequency, grid and converter inductance ratio, and capacitance of the LCL-filter allow calculating all the LCL-filter parameters. An estimation for the achieved Total Harmonic Distortion (THD) of the grid current...

  5. Combined Particle Filter and Selective Catalytic Reduction Catalyst for Diesel Engines

    DEFF Research Database (Denmark)

    Hvam, Jeanette

    them ideal for multiple applications like high power electronic devices, heating elements, abrasive materials and cutting tools. Porous silicon carbide is suitable for electrode and catalyst support material as well as hot gas filter units or a combination of these. The automotive industry demands new...... for exhaust gas purification. By combining the particulate filtration application with the application as catalyst support for NOx reduction, the low emissions standards can be met. This project was initiated as a result of the need for new and improved filters with characteristics making it suitable...... here. A new and improved filter was developed on the basis of the research results concerning copper as partner additive. In comparison to filters produced with aluminium as sole additive, these new filters exhibit enhanced mechanical stability, enhanced microstructure and controllable surface...

  6. Comparison of the structure and composition of the branchial filters in suspension feeding elasmobranchs.

    Science.gov (United States)

    Misty Paig-Tran, E W; Summers, A P

    2014-04-01

    The four, evolutionarily independent, lineages of suspension feeding elasmobranchs have two types of branchial filters. The first is a robust, flattened filter pad akin to a colander (e.g., whale sharks, mantas and devil rays) while the second more closely resembles the comb-like gill raker structure found in bony fishes (e.g., basking and megamouth sharks). The structure and the presence of mucus on the filter elements will determine the mechanical function of the filter and subsequent particle transport. Using histology and scanning electron microscopy, we investigated the anatomy of the branchial filters in 12 of the 14 species of Chondrichthyian filter-feeding fishes. We hypothesized that mucus producing cells would be abundant along the filter epithelium and perform as a sticky mechanism to retain and transport particles; however, we found that only three species had mucus producing goblet cells. Two of these (Mobula kuhlii and Mobula tarapacana) also had branchial cilia, indicating sticky retention and transport. The remaining filter-feeding elasmobranchs did not have a sticky surface along the filter for particles to collect and instead must employ alternative mechanisms of filtration (e.g., direct sieving, inertial impaction or cross-flow). With the exception of basking sharks, the branchial filter is composed of a hyaline cartilage skeleton surrounded by a layer of highly organized connective tissue that may function as a support. Megamouth sharks and most of the mobulid rays have denticles along the surface of the filter, presumably to protect against damage from large particle impactions. Basking sharks have branchial filters that lack a cartilaginous core; instead they are composed entirely of smooth keratin. Copyright © 2014 Wiley Periodicals, Inc.

  7. Spatial filtering velocimetry for real-time out-of-plane displacement measurements

    DEFF Research Database (Denmark)

    Olesen, Anders Sig; Yura, H.T.; Jakobsen, Michael Linde

    2016-01-01

    We probe the dynamics of objective laser speckles as the axial distance between the object and the observation plane changes. With the purpose of measuring out-of-plane motion in real time, we apply optical spatial filtering velocimetry to the speckle dynamics. To achieve this, a rotationally sym...... element which implements the spatial filter and experimentally demonstrate the ability of the technology to obtain displacement measurements of a vibrating object in real-time....

  8. Kalman Filtering with Real-Time Applications

    CERN Document Server

    Chui, Charles K

    2009-01-01

    Kalman Filtering with Real-Time Applications presents a thorough discussion of the mathematical theory and computational schemes of Kalman filtering. The filtering algorithms are derived via different approaches, including a direct method consisting of a series of elementary steps, and an indirect method based on innovation projection. Other topics include Kalman filtering for systems with correlated noise or colored noise, limiting Kalman filtering for time-invariant systems, extended Kalman filtering for nonlinear systems, interval Kalman filtering for uncertain systems, and wavelet Kalman filtering for multiresolution analysis of random signals. Most filtering algorithms are illustrated by using simplified radar tracking examples. The style of the book is informal, and the mathematics is elementary but rigorous. The text is self-contained, suitable for self-study, and accessible to all readers with a minimum knowledge of linear algebra, probability theory, and system engineering.

  9. Nonlinear Filtering in High Dimension

    Science.gov (United States)

    2014-06-02

    Dan Crisan , Ajay Jasra, and Nick Whiteley. Error bounds and normalizing constants for sequential Monte Carlo in high dimensions, 2012. Preprint arxiv... Crisan and Boris Rozovskĭı, editors. The Oxford handbook of nonlinear filtering. Oxford University Press, Oxford, 2011. [14] T. de la Rue, R

  10. ISEE-3 Microwave Filter Requirements

    Science.gov (United States)

    Galvez, J. L.; Marlin, H.; Stanton, P.

    1984-01-01

    The 64 m subnet is committed to support the International Sun Earth Explorer (ISEE-3) spacecraft. The uplink and one of the downlink frequencies will be respectively, 2090 and 2217 MHz. As these two frequencies fall outside the normal DSN transmit and receive bands, the 64-m antennas present new filter requirements, which are analyzed.

  11. Conflict-Induced Perceptual Filtering

    Science.gov (United States)

    Wendt, Mike; Luna-Rodriguez, Aquiles; Jacobsen, Thomas

    2012-01-01

    In a variety of conflict paradigms, target and distractor stimuli are defined in terms of perceptual features. Interference evoked by distractor stimuli tends to be reduced when the ratio of congruent to incongruent trials is decreased, suggesting conflict-induced perceptual filtering (i.e., adjusting the processing weights assigned to stimuli…

  12. Dealing with the Filtering Stigma.

    Science.gov (United States)

    Minkel, Walter

    2000-01-01

    Discusses how to, or whether to, limit access to objectionable material available through the Internet in public and school libraries. Topics include the American Library Association's position; intellectual freedom; filters; personal responsibility; parental responsibility; censorship; creating choices; and policies and staff training to help…

  13. Conversion and matched filter approximations for serial minimum-shift keyed modulation

    Science.gov (United States)

    Ziemer, R. E.; Ryan, C. R.; Stilwell, J. H.

    1982-01-01

    Serial minimum-shift keyed (MSK) modulation, a technique for generating and detecting MSK using series filtering, is ideally suited for high data rate applications provided the required conversion and matched filters can be closely approximated. Low-pass implementations of these filters as parallel inphase- and quadrature-mixer structures are characterized in this paper in terms of signal-to-noise ratio (SNR) degradation from ideal and envelope deviation. Several hardware implementation techniques utilizing microwave devices or lumped elements are presented. Optimization of parameter values results in realizations whose SNR degradation is less than 0.5 dB at error probabilities of .000001.

  14. Nonlinear performance characterization in an eight-pole quasi-elliptic bandpass filter

    Energy Technology Data Exchange (ETDEWEB)

    Mateu, J [Centre Tecnologic de Telecomunicacions de Catalunya, Edifici Nexus, Gran Capita, 2nd Floor, Room 202-203, 08034 Barcelona (Spain); Collado, C [Universitat Politecnica de Catalunya, Department of Signal Theory and Communications, Campus Nord UPC, D3-Jordi Girona, 1-3, 08034 Barcelona (Spain); Menendez, O [Universitat Politecnica de Catalunya, Department of Signal Theory and Communications, Campus Nord UPC, D3-Jordi Girona, 1-3, 08034 Barcelona (Spain); O' Callaghan, J M [Universitat Politecnica de Catalunya, Department of Signal Theory and Communications, Campus Nord UPC, D3-Jordi Girona, 1-3, 08034 Barcelona (Spain)

    2004-05-01

    In this work we predict the nonlinear behaviour of an eight-pole quasi-elliptic bandpass high temperature superconducting (HTS) filter with an equivalent circuit extracted from intermodulation measurements performed at the centre of the filter passband. We present measurements that show that the equivalent circuit is able to predict the intermodulation products produced by the filter when driven by two in-band or out-of-band sinusoidal signals. Numerical techniques based on harmonic balance are used to extract the elements of the equivalent circuit and to simulate its nonlinear performance.

  15. A pseudo-matched filter for chaos

    OpenAIRE

    Cohen, Seth D.; Gauthier, Daniel J.

    2012-01-01

    A matched filter maximizes the signal-to-noise ratio of a signal. In the recent work of Corron et al. [Chaos 20, 023123 (2010)], a matched filter is derived for the chaotic waveforms produced by a piecewise-linear system. Motivated by these results, we describe a pseudo-matched filter, which removes noise from the same chaotic signal. It consists of a notch filter followed by a first-order, low-pass filter. We compare quantitatively the matched filter's performance to that of our pseudo-match...

  16. Performance comparison of various time variant filters

    Energy Technology Data Exchange (ETDEWEB)

    Kuwata, M. [JEOL Engineering Co. Ltd., Akishima, Tokyo (Japan); Husimi, K.

    1996-07-01

    This paper describes the advantage of the trapezoidal filter used in semiconductor detector system comparing with the other time variant filters. The trapezoidal filter is the compose of a rectangular pre-filter and a gated integrator. We indicate that the best performance is obtained by the differential-integral summing type rectangular pre-filter. This filter is not only superior in performance, but also has the useful feature that the rising edge of the output waveform is linear. We introduce an example of this feature used in a high-energy experiment. (author)

  17. A pseudo-matched filter for chaos.

    Science.gov (United States)

    Cohen, Seth D; Gauthier, Daniel J

    2012-09-01

    A matched filter maximizes the signal-to-noise ratio of a signal. In the recent work of Corron et al. [Chaos 20, 023123 (2010)], a matched filter is derived for the chaotic waveforms produced by a piecewise-linear system. This system produces a readily available binary symbolic dynamics that can be used to perform correlations in the presence of large amounts of noise using the matched filter. Motivated by these results, we describe a pseudo-matched filter, which operates similarly to the original matched filter. It consists of a notch filter followed by a first-order, low-pass filter. We compare quantitatively the matched filter's performance to that of our pseudo-matched filter using correlation functions. On average, the pseudo-matched filter performs with a correlation signal-to-noise ratio that is 2.0 dB below that of the matched filter. Our pseudo-matched filter, though somewhat inferior in comparison to the matched filter, is easily realizable at high speed (>1 GHz) for potential radar applications.

  18. Marginalized Particle Filtering Framework for Tuning of Ensemble Filters

    Czech Academy of Sciences Publication Activity Database

    Šmídl, Václav; Hofman, Radek

    2011-01-01

    Roč. 139, č. 11 (2011), s. 3589-3599 ISSN 0027-0644 R&D Projects: GA MV VG20102013018; GA ČR GP102/08/P250 Institutional research plan: CEZ:AV0Z10750506 Keywords : ensemble finter * marginalized particle filter * data assimilation Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 2.688, year: 2011 http://library.utia.cas.cz/separaty/2011/AS/smidl-0367533.pdf

  19. A Study of Parallel Operation of an active Filter and passive Filters

    DEFF Research Database (Denmark)

    Chen, Zhe; Blaabjerg, Frede; Pedersen, John Kim

    2002-01-01

    This paper reports investigations of the parallel operations of a current controlled active filter and passive filters in a system with current harmonic sources. The task of reactive power and harmonic compensation is shared by the active filter and passive filters. The passive filters are used...... arrangements of the active and passive filters can operate relatively independently, also the compensation flexibility of the active filter can be fully exploited, such as one active filter for several harmonic sources.The simulation studies on various systems have been performed to evaluate the effectiveness...... for supplying reactive power to the connected ac system and eliminating some harmonics, the active filter is used to cancel out the other harmonics. This can be achieved by taking the suitable reference current of the active filter and signal processing filters in the control loop.In parallel combination...

  20. Digital Filter Performance for the ATLAS Level-1 Calorimeter Trigger

    CERN Document Server

    Hadley, D R; The ATLAS collaboration

    2010-01-01

    The ATLAS Level-1 Calorimeter Trigger is a hardware-based system designed to identify high-pT jets, electron/photon and tau candidates, and to measure total and missing ET in the ATLAS Liquid Argon and Tile calorimeters. It is a pipelined processor system, with a new set of inputs being evaluated every 25ns. The overall trigger decision has a latency budget of 2µs, including all transmission delays. The calorimeter trigger uses about 7200 reduced granularity analogue signals, which are first digitized at the 40 MHz LHC bunch-crossing frequency, before being passed to a digital Finite Impulse Response (FIR) filter. Due to latency and chip real-estate constraints, only a simple 5-element filter with limited precision can be used. Nevertheless this filter achieves a significant reduction in noise, along with improving the bunch-crossing assignment and energy resolution for small signals. The context in which digital filters are used for the ATLAS Level-1 Calorimeter Trigger will be presented, before describing ...

  1. Damage visualization enhancement by the wave field filtering and processing

    Science.gov (United States)

    Kudela, Pawel; Radzienski, Maciej; Ostachowicz, Wieslaw

    2012-04-01

    The aim of this paper is to present methods for enhancing damage visualization in structures based on wave propagation phenomenon. The method utilizes filtering and processing of full wavefield acquired by the laser vibrometer. Laser vibrometer allows to register full wavefield in elements of a structure instead of single point measurements acquired by e.g. piezoelectric sensor. In this way new possibilities for Nondestructive Evaluation arise enabling visualization of elastic waves interacting with various types of damages. Measurements obtained with a scanning laser vibrometer can be combined with effective signal and imaging processing algorithms to support damage identification. In this paper new method for wave filtering of propagating waves is tested on both numerical results and experimental data obtained from laser vibrometry measurements of composite plates. Processing of signals registered at a rectangular grid of measurement points covering inspected area of the plate involve 2D DFFT (Discrete Fast Fourier Transform), wavenumber filtering and inverse DFFT. As a result new damage index is proposed and compared with other methods like RMS and frequency-wavenumber filtering.

  2. A new deblurring morphological filter for hyperspectral images

    Science.gov (United States)

    Abdelkawy, Ezz Eldin F.; Mahmoud, Tarek A.; Hussein, Wesam M.

    2011-06-01

    Hyperspectral imaging becomes an important technique that increases the valuable information enclosed within the image. Spectral cube produced by this type of imaging introduces a new material signature known as "spectral signature". This signature is unique for each material as it depends on the molecular composition of the material surface. To produce the spectral cube, a spectrometer should be used in the imagery device to split the electromagnetic energy at different wavelengths before its projection on the imaging array. This spectrometer may be a dispersive element, such as prism and grating, or an electronically tuneable filter. Some of dispersive spectrometers, such as Fourier transform interferometer (FTIR) and image multi-spectral imaging (IMSS), are based on sliding the lenses, or mirrors, along the optical axis which may result in a slightly out-of-focus blurring. Blind deconvolution techniques have been successfully used to decrease this blurring but at the expense of edge sharpening which may be a problem in some applications such as target detection and recognition. In this paper, we introduce a new method to deblurr the hyperspectral images keeping edges as sharp as possible. This is done by firstly detecting the edges locations and then applying a class of morphological filtering. Motivated by the success of threshold decomposition, gradient-based operators are used to detect the locations of these edges followed by an adaptive morphological filter to sharpen these detected edges. Experimental results demonstrate that the performance of the proposed deblurring filter is superior to that of the blind deconvolution methods.

  3. Comparative, validity and responsiveness of the HOOS-PS and KOOS-PS to the WOMAC physical function subscale in total joint replacement for osteoarthritis

    DEFF Research Database (Denmark)

    Davis, A M; Perruccio, A V; Canizares, M

    2009-01-01

    OBJECTIVE: To evaluate the internal consistency of the Hip disability and Osteoarthritis Outcome Score-Physical Function Short-form (HOOS-PS) and the Knee injury and Osteoarthritis Outcome Score-Physical Function Short-form (KOOS-PS) in total hip replacement (THR) and total knee (TKR) replacement....... Construct validity and responsiveness were compared to the Western Ontario McMaster Universities' Osteoarthritis Index (WOMAC) Likert 3.0 physical function (PF) subscale and the PF excluding the items in the short measures (PF-exclusions). METHODS: Participants completed the full HOOS or KOOS, measures...... of fatigue, anxiety, depression and the Chronic Pain Grade (CPG) pre-surgery and the HOOS or KOOS 6 months post-surgery. Internal consistency for the HOOS-PS and KOOS-PS was calculated using Cronbach's alpha. For construct validity, it was hypothesized that correlations between the HOOS-PS or KOOS-PS and PF...

  4. Validity of the definite and semidefinite questionnaire version of the Hamilton Depression Scale, the Hamilton subscale and the Melancholia Scale. Part I

    DEFF Research Database (Denmark)

    Hansen, Jesper Bent; Bech, Per

    2011-01-01

    , and their corresponding definite versions of the self-rating questionnaires DMQ and DHAM6 were accepted by the Rasch analysis, and only these four valid scales discriminated significantly between the effect of citalopram and placebo treatment. Our results are limited to patients with moderate depression. Two new self......-reporting versions (definitely and semidefinitely anchored) corresponding to the Hamilton Depression Scale (HAMD), the Hamilton Subscale (HAM6), and the Bech-Rafaelsen Melancholia Scale (MES) were compared to each other and the clinician-rated version. The unidimensional property of the sum score in each scale...... was tested by the item-response theory model ad modum Rasch. The scales were also tested for their sensitivity to discriminate between placebo and citalopram therapy. The sum scores and the sum score variances of the definite self-rating versions did not differ significantly from the sum scores...

  5. Evidence That the Clinical Impairment Assessment (CIA) Subscales Should Not Be Scored: Bifactor Modelling, Reliability, and Validity in Clinical and Community Samples.

    Science.gov (United States)

    Raykos, Bronwyn; Erceg-Hurn, David; McEvoy, Peter; Byrne, Susan M

    2017-09-01

    The Clinical Impairment Assessment (CIA 3.0) is the most widely used instrument assessing psychosocial impairment secondary to eating disorder symptoms. However, there is conflicting advice regarding the dimensionality and optimal method of scoring the CIA. We sought to resolve this confusion by conducting a comprehensive factor analytic study of the CIA in a community sample ( N = 301) and clinical sample comprising patients with a diagnosed eating disorder ( N = 209). Convergent and discriminant validity were also assessed. The CIA and measures of eating disorder symptoms were administered to both samples. Factor analyses indicated there is a general impairment factor underlying all items on the CIA that is reliably measured by the CIA Global score. CIA Global demonstrated good convergent and discriminant validity. CIA Global is a reliable and valid measure of psychosocial impairment secondary to eating disorder symptoms; however, subscale scores should not be computed.

  6. ELECTROSTATICALLY ENHANCED BARRIER FILTER COLLECTION

    Energy Technology Data Exchange (ETDEWEB)

    John Erjavec; Michael D. Mann; Ryan Z. Knutson; Michael L. Swanson; Michael E. Collings

    2003-06-01

    This work was performed through the University of North Dakota (UND) Chemical Engineering Department with assistance from UND's Energy & Environmental Research Center. This research was undertaken in response to the U.S. Department of Energy Federal Technology Center Program Solicitation No. DE-PS26-99FT40479, Support of Advanced Coal Research at U.S. Universities and Colleges. Specifically, this research was in support of the UCR Core Program and addressees Topic 1, Improved Hot-Gas Contaminant and Particulate Removal Techniques, introducing an advanced design for particulate removal. Integrated gasification combined cycle (IGCC) offers the potential for very high efficiency and clean electric generation. In IGCC, the product gas from the gasifier needs to be cleaned of particulate matter to avoid erosion and high-temperature corrosion difficulties arising with the turbine blades. Current methods involve cooling the gases to {approx}100 C to condense alkalis and remove sulfur and particulates using conventional scrubber technology. This ''cool'' gas is then directed to a turbine for electric generation. While IGCC has the potential to reach efficiencies of over 50%, the current need to cool the product gas for cleaning prior to firing it in a turbine is keeping IGCC from reaching its full potential. The objective of the current project was to develop a highly reliable particulate collector system that can meet the most stringent turbine requirements and emission standards, can operate at temperatures above 1500 F, is applicable for use with all U.S. coals, is compatible with various sorbent injection schemes for sulfur and alkali control, can be integrated into a variety of configurations for both pressurized gasification and combustion, increases allowable face velocity to reduce filter system capital cost, and is cost-competitive with existing technologies. The collector being developed is a new concept in particulate control called

  7. Kalman filtering with real-time applications

    CERN Document Server

    Chui, Charles K

    2017-01-01

    This new edition presents a thorough discussion of the mathematical theory and computational schemes of Kalman filtering. The filtering algorithms are derived via different approaches, including a direct method consisting of a series of elementary steps, and an indirect method based on innovation projection. Other topics include Kalman filtering for systems with correlated noise or colored noise, limiting Kalman filtering for time-invariant systems, extended Kalman filtering for nonlinear systems, interval Kalman filtering for uncertain systems, and wavelet Kalman filtering for multiresolution analysis of random signals. Most filtering algorithms are illustrated by using simplified radar tracking examples. The style of the book is informal, and the mathematics is elementary but rigorous. The text is self-contained, suitable for self-study, and accessible to all readers with a minimum knowledge of linear algebra, probability theory, and system engineering. Over 100 exercises and problems with solutions help de...

  8. Deep Ultraviolet Macroporous Silicon Filters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I proposal describes a novel method to make deep and far UV optical filters from macroporous silicon. This type of filter consists of an array of...

  9. Detecting recursive and nonrecursive filters using chaos.

    Science.gov (United States)

    Carroll, T L

    2010-03-01

    Filtering a chaotic signal through a recursive [or infinite impulse response (IIR)] filter has been shown to increase the dimension of chaos under certain conditions. Filtering with a nonrecursive [or finite impulse response (FIR)] filter should not increase dimension, but it has been shown that if the FIR filter has a long tail, measurements of actual signals may appear to show a dimension increase. I simulate IIR and FIR filters that correspond to naturally occurring resonant objects, and I show that using dimension measurements, I can distinguish the filter type. These measurements could be used to detect resonances using radar, sonar, or laser signals, or to determine if a resonance is due to an IIR or an FIR filter.

  10. Internet Filters: Censorship by Any Other Name?

    Science.gov (United States)

    Johnson, Doug

    1998-01-01

    Discusses whether libraries should limit access to the Internet by the use of filtering devices or blockers. Topics include censorship issues; access to information; filtering software; intellectual freedom; costs; acceptable-use policies; and self-regulation. (LRW)

  11. Blocking Detection Based on Synoptic Filters

    Directory of Open Access Journals (Sweden)

    Bernd Schalge

    2011-01-01

    minimum zonal width, and (iii a persistence filter to extract events with a minimum duration. Practical filter application is analysed in two case studies and the blocking climatologies for the Northern and the Southern Hemisphere.

  12. A new martingale approach to Kalman Filtering

    NARCIS (Netherlands)

    Bagchi, Arunabha

    1976-01-01

    A new derivation of continuous-time Kalman Filter equations is presented. The underlying idea has been previously used to derive the smoothing equations. A unified approach to filtering and smoothing problems has thus been achieved.

  13. On filter boundary conditions in topology optimization

    DEFF Research Database (Denmark)

    Clausen, Anders; Andreassen, Erik

    2017-01-01

    Most research papers on topology optimization involve filters for regularization. Typically, boundary effects from the filters are ignored. Despite significant drawbacks the inappropriate homogeneous Neumann boundary conditions are used, probably because they are trivial to implement. In this paper...

  14. LMS filter for noise cancellation using Simulink

    Science.gov (United States)

    Talele, K. T.; Shrivastav, Ashish; Utekar, Kunal; Deshpande, Abhishek

    2011-06-01

    In this paper we have proposed the simplified implementation of adaptive noise cancellation using LMS filter. The LMS algorithm belongs to the family of stochastic gradient algorithms. It is one of the efficient algorithms in adaptive filtering.

  15. Could 'Safer' Filtered Cigarettes Be More Deadly?

    Science.gov (United States)

    ... gov/news/fullstory_165825.html Could 'Safer' Filtered Cigarettes Be More Deadly? New report suggests they're ... 2017 MONDAY, May 22, 2017 (HealthDay News) -- Filtered cigarettes might be even more lethal than unfiltered ones, ...

  16. Media filter drain : modified design evaluation.

    Science.gov (United States)

    2014-09-01

    The media filter drain (MFD), a stormwater water quality treatment best management practice, consists of media made up of : aggregate, perlite, gypsum and dolomite in a trench located along roadway shoulders with gravel and vegetative pre-filtering f...

  17. A comparative validation of the abbreviated Apathy Evaluation Scale (AES-10) with the Neuropsychiatric Inventory apathy subscale against diagnostic criteria of apathy.

    Science.gov (United States)

    Leontjevas, Ruslan; Evers-Stephan, Alexandra; Smalbrugge, Martin; Pot, Anne Margriet; Thewissen, Viviane; Gerritsen, Debby L; Koopmans, Raymond T C M

    2012-03-01

    To compare the Neuropsychiatric Inventory apathy subscale (NPIa) with the abbreviated Apathy Evaluation Scale (AES-10) on discriminant validity and on their performance to distinguish residents as apathetic or nonapathetic. Cross-sectional design. Nursing home. 100 residents of 4 dementia special care units (n = 58) and 3 somatic units (n = 42). Primary professional caregivers were interviewed to score the AES-10 and NPIa. The elderly care physician and the psychologist of each unit examined residents for clinical apathy using diagnostic criteria. The AES-10 and NPIa correlated moderately with each other (r(s) = 0.62, P AES-10 correlated weakly (r(s) = 0.27, P = .024) and the NPIa moderately (r(s) = 0.46, P = .001) with the Cornell Scale for Depression in Dementia. Receiver operating characteristic analysis showed an area under the curve (AUC) of 0.72 (P AES-10 and 0.67 (P AES-10 produced higher sums of sensitivity and negative predictive value than the NPIa. Explorative analyses revealed that both instruments produced higher scores in dementia independently of having an apathy diagnosis, whereas AUCs were significant in nondementia (AES-10: AUC = 0.88, P AES-10 and NPIa may be used to distinguish apathetic from nonapathetic residents in a heterogeneous sample with and without dementia, or in residents without dementia. The AES-10 may be preferable to the NPIa apathy subscale when ruling out or screening for apathy. The performance of the scales against diagnostic criteria of apathy in dementia need to be further examined. Copyright © 2012 American Medical Directors Association, Inc. Published by Elsevier Inc. All rights reserved.

  18. Nonlinear Vibration Signal Tracking of Large Offshore Bridge Stayed Cable Based on Particle Filter

    Directory of Open Access Journals (Sweden)

    Ye Qingwei

    2015-12-01

    Full Text Available The stayed cables are key stress components of large offshore bridge. The fault detection of stayed cable is very important for safe of large offshore bridge. A particle filter model and algorithm of nonlinear vibration signal are used in this paper. Firstly, the particle filter model of stayed cable of large offshore bridge is created. Nonlinear dynamic model of the stayed-cable and beam coupling system is dispersed in temporal dimension by using the finite difference method. The discrete nonlinear vibration equations of any cable element are worked out. Secondly, a state equation of particle filter is fitted by least square algorithm from the discrete nonlinear vibration equations. So the particle filter algorithm can use the accurate state equations. Finally, the particle filter algorithm is used to filter the vibration signal of bridge stayed cable. According to the particle filter, the de-noised vibration signal can be tracked and be predicted for a short time accurately. Many experiments are done at some actual bridges. The simulation experiments and the actual experiments on the bridge stayed cables are all indicating that the particle filter algorithm in this paper has good performance and works stably.

  19. Investigation of Dual-Mode Microstrip Bandpass Filter Based on SIR Technique.

    Directory of Open Access Journals (Sweden)

    Yaqeen S Mezaal

    Full Text Available In this paper, a new bandpass filter design has been presented using simple topology of stepped impedance square loop resonator. The proposed bandpass filter has been simulated and fabricated using a substrate with an insulation constant of 10.8, thickness of 1.27mm and loss tangent of 0.0023 at center frequency of 5.8 GHz. The simulation results have been evaluated using Sonnet simulator that is extensively adopted in microwave analysis and implementation. The output frequency results demonstrated that the proposed filter has high-quality frequency responses in addition to isolated second harmonic frequency. Besides, this filter has very small surface area and perceptible narrow band response features that represent the conditions of recent wireless communication systems. Various filter specifications have been compared with different magnitudes of perturbation element dimension. Furthermore, phase scattering response and current intensity distribution of the proposed filter have been discussed. The simulated and experimental results are well-matched. Lastly, the features of the proposed filter have been compared with other designed microstrip filters in the literature.

  20. Novel Resistorless First-Order Current-Mode Universal Filter Employing a Grounded Capacitor

    Directory of Open Access Journals (Sweden)

    R. Arslanalp

    2011-09-01

    Full Text Available In this paper, a new bipolar junction transistor (BJT based configuration for providing first-order resistorless current-mode (CM all-pass, low-pass and high-pass filter responses from the same configuration is suggested. The proposed circuit called as a first-order universal filter possesses some important advantages such as consisting of a few BJTs and a grounded capacitor, consuming very low power and having electronic tunability property of its pole frequency. Additionally, types of filter response can be obtained only by changing the values of current sources. The suggested circuit does not suffer from disadvantages of use of the resistors in IC process. The presented first-order universal filter topology does not need any passive element matching constraints. Moreover, as an application example, a second-order band-pass filter is obtained by cascading two proposed filter structures which are operating as low-pass filter and high-pass one. Simulations by means of PSpice program are accomplished to demonstrate the performance and effectiveness of the developed first-order universal filter.

  1. Investigation of Dual-Mode Microstrip Bandpass Filter Based on SIR Technique

    Science.gov (United States)

    Mezaal, Yaqeen S.; Ali, Jawad K.

    2016-01-01

    In this paper, a new bandpass filter design has been presented using simple topology of stepped impedance square loop resonator. The proposed bandpass filter has been simulated and fabricated using a substrate with an insulation constant of 10.8, thickness of 1.27mm and loss tangent of 0.0023 at center frequency of 5.8 GHz. The simulation results have been evaluated using Sonnet simulator that is extensively adopted in microwave analysis and implementation. The output frequency results demonstrated that the proposed filter has high-quality frequency responses in addition to isolated second harmonic frequency. Besides, this filter has very small surface area and perceptible narrow band response features that represent the conditions of recent wireless communication systems. Various filter specifications have been compared with different magnitudes of perturbation element dimension. Furthermore, phase scattering response and current intensity distribution of the proposed filter have been discussed. The simulated and experimental results are well-matched. Lastly, the features of the proposed filter have been compared with other designed microstrip filters in the literature. PMID:27798675

  2. Improving Bloom Filter Performance on Sequence Data Using k-mer Bloom Filters.

    Science.gov (United States)

    Pellow, David; Filippova, Darya; Kingsford, Carl

    2017-06-01

    Using a sequence's k-mer content rather than the full sequence directly has enabled significant performance improvements in several sequencing applications, such as metagenomic species identification, estimation of transcript abundances, and alignment-free comparison of sequencing data. As k-mer sets often reach hundreds of millions of elements, traditional data structures are often impractical for k-mer set storage, and Bloom filters (BFs) and their variants are used instead. BFs reduce the memory footprint required to store millions of k-mers while allowing for fast set containment queries, at the cost of a low false positive rate (FPR). We show that, because k-mers are derived from sequencing reads, the information about k-mer overlap in the original sequence can be used to reduce the FPR up to 30 × with little or no additional memory and with set containment queries that are only 1.3 - 1.6 times slower. Alternatively, we can leverage k-mer overlap information to store k-mer sets in about half the space while maintaining the original FPR. We consider several variants of such k-mer Bloom filters (kBFs), derive theoretical upper bounds for their FPR, and discuss their range of applications and limitations.

  3. The filter pads and filtration mechanisms of the devil rays: Variation at macro and microscopic scales.

    Science.gov (United States)

    Paig-Tran, E W Misty; Kleinteich, Thomas; Summers, Adam P

    2013-09-01

    Three lineages of cartilaginous fishes have independently evolved filter feeding (Lamniformes: Megachasma and Cetorhinus, Orectolobiformes: Rhincodon, and Mobulidae: Manta and Mobula); and the structure of the branchial filters is different in each group. The filter in Rhincodon typus has been described; species within the Lamniformes have simple filamentous filters, but the anatomy and ultrastructure of the branchial filter in the mobulid rays varies and is of functional interest. In most fishes, branchial gill rakers are elongated structures located along the anterior ceratobranchial and/or epibranchial arches; however, mobulid gill rakers are highly modified, flattened, lobe-like structures located on the anterior and posterior epibranchial elements as well as the ceratobranchials. The ultrastructure of the filter lobes can be smooth or covered by a layer of microcilia, and some are denticulated along the dorsal and ventral lobe surface. Flow through the mobulid oropharyngeal cavity differs from other filter-feeding fishes in that water must rapidly deviate from the free stream direction. There is an abrupt 90° turn from the initial inflowing path to move through the laterally directed branchial filter pores, over the gill tissue, and out the ventrally located gill slits. The deviation in the flow must result in tangential shearing stress across the filter surface. This implies that mobulids can use cross-flow filtration in which this shearing force serves as a mechanism to resuspend food particles initially caught by sieving or another capture mode. These particles will be transported by the cross filter flow toward the esophagus. We propose that species with cilia on the rakers augment the shear mediated movement of particles along the filter with ciliary transport. Copyright © 2013 Wiley Periodicals, Inc.

  4. Practical investigations on monolithic integrated microwave filters

    OpenAIRE

    Stephan, R; Möhring, J.

    1996-01-01

    Filters at microwave frequencies today normally are built in hybrid technology. In this paper principles for the monolit­hic integration of frequency selective structures without any external component are investigated. Monolithic Filters at frequencies about 10 GHz based on lumped LC-structures and about 30 GHz in coplanar waveguide technology are presented. Both filter concepts need active components to compensate the insertion loss of the filters. All components are interconnected by copla...

  5. Mixtures of skewed Kalman filters

    KAUST Repository

    Kim, Hyoungmoon

    2014-01-01

    Normal state-space models are prevalent, but to increase the applicability of the Kalman filter, we propose mixtures of skewed, and extended skewed, Kalman filters. To do so, the closed skew-normal distribution is extended to a scale mixture class of closed skew-normal distributions. Some basic properties are derived and a class of closed skew. t distributions is obtained. Our suggested family of distributions is skewed and has heavy tails too, so it is appropriate for robust analysis. Our proposed special sequential Monte Carlo methods use a random mixture of the closed skew-normal distributions to approximate a target distribution. Hence it is possible to handle skewed and heavy tailed data simultaneously. These methods are illustrated with numerical experiments. © 2013 Elsevier Inc.

  6. Ceramic hot-gas filter

    Science.gov (United States)

    Connolly, Elizabeth Sokolinski; Forsythe, George Daniel; Domanski, Daniel Matthew; Chambers, Jeffrey Allen; Rajendran, Govindasamy Paramasivam

    1999-01-01

    A ceramic hot-gas candle filter having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during backpulse cleaning and is resistant to chemical degradation at high temperatures.

  7. Quantification of multiple elements in dried blood spot samples.

    Science.gov (United States)

    Pedersen, Lise; Andersen-Ranberg, Karen; Hollergaard, Mads; Nybo, Mads

    2017-08-01

    Dried blood spots (DBS) is a unique matrix that offers advantages compared to conventional blood collection making it increasingly popular in large population studies. We here describe development and validation of a method to determine multiple elements in DBS. Elements were extracted from punches and analyzed using inductively coupled plasma-mass spectrometry (ICP-MS). The method was evaluated with quality controls with defined element concentration and blood spiked with elements to assess accuracy and imprecision. DBS element concentrations were compared with concentrations in venous blood. Samples with different hematocrit were spotted onto filter paper to assess hematocrit effect. The established method was precise and accurate for measurement of most elements in DBS. There was a significant but relatively weak correlation between measurement of the elements Mg, K, Fe, Cu, Zn, As and Se in DBS and venous whole blood. Hematocrit influenced the DBS element measurement, especially for K, Fe and Zn. Trace elements can be measured with high accuracy and low imprecision in DBS, but contribution of signal from the filter paper influences measurement of some elements present at low concentrations. Simultaneous measurement of K and Fe in DBS extracts may be used to estimate sample hematocrit. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  8. 27 CFR 24.243 - Filtering aids.

    Science.gov (United States)

    2010-04-01

    ... OF THE TREASURY LIQUORS WINE Storage, Treatment and Finishing of Wine § 24.243 Filtering aids. Inert fibers, pulps, earths, or similar materials, may be used as filtering aids in the cellar treatment and... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Filtering aids. 24.243...

  9. 21 CFR 211.72 - Filters.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Filters. 211.72 Section 211.72 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR FINISHED PHARMACEUTICALS Equipment § 211.72 Filters. Filters for liquid...

  10. Cryptosporidium: A Guide to Water Filters

    Science.gov (United States)

    ... for cyst reduction Filters labeled only with these words may NOT be designed to remove Crypto Nominal pore size of 1 micron or smaller One micron filter Effective against Giardia Effective against parasites Carbon filter Water purifier EPA approved ( Caution: EPA does not approve ...

  11. z-transform DFT filters and FFT's

    DEFF Research Database (Denmark)

    Bruun, G.

    1978-01-01

    The paper shows how discrete Fourier transformation can be implemented as a filter bank in a way which reduces the number of filter coefficients. A particular implementation of such a filter bank is directly related to the normal complex FFT algorithm. The principle developed further leads to typ...

  12. Measurement and expression of granular filter cleanliness

    African Journals Online (AJOL)

    2013-09-23

    Sep 23, 2013 ... The problem of dirty filter media at water treatment plants, despite having good backwash systems, is a serious challenge that requires ... of problem filters, this paper firstly proposes a standard procedure for quantification of the specific deposit on filter media, ..... 14-18 November, 2004, San Antonio, Texas.

  13. Electrically heated particulate filter restart strategy

    Science.gov (United States)

    Gonze, Eugene V [Pinckney, MI; Ament, Frank [Troy, MI

    2011-07-12

    A control system that controls regeneration of a particulate filter is provided. The system generally includes a propagation module that estimates a propagation status of combustion of particulate matter in the particulate filter. A regeneration module controls current to the particulate filter to re-initiate regeneration based on the propagation status.

  14. Distortion invariant pattern recognition with phase filters

    Science.gov (United States)

    Rosen, Joseph; Shamir, Joseph

    1987-01-01

    A recently developed approach for pattern recognition using spatial filters with reduced tolerance requirements is employed for the generation of filters containing mainly phase information. As anticipated, the recognition levels were decreased, but they remain adequate for unambiguous identification together with appreciable amounts of distortion immunity. Furthermore, the information content of the filters is compatible with low devices like spatial light modulators.

  15. Filters: It's Not about Porn, Stupid!

    Science.gov (United States)

    Schuyler, Michael

    1997-01-01

    Discusses libraries' uses of filters to prevent access to objectionable sites on the Internet. Highlights include the American Library Association's resolution against filters as a violation of First Amendment rights; patron's use of terminals for e-mail or games; using filters for collection management; and listservs and online resources…

  16. Scale and weight consideration of emi filters

    NARCIS (Netherlands)

    Roc'h, A.; Zhao, D.; Ferreira, B.; Leferink, Frank Bernardus Johannes

    2009-01-01

    Amongst the main constraints faced by the designer of EMI filters is the performance sensitivity to system weight. The design of the common mode filter is an important aspect of the weight and space management of an aerospace system. Designable parameters of this filter and its material properties

  17. Implementation of Spatial Domain Homomorphic Filtering on ...

    African Journals Online (AJOL)

    This paper describes the analysis of the Homomorphic filtering algorithm, the equivalency between the frequency and spatial-domain methods and the implementation of low-pass and high-pass spatial domain Homomorphic filter in low power embedded devices. It is shown that the Homomorphic filter in the spatial domain ...

  18. Notch filters for port-Hamiltonian systems

    NARCIS (Netherlands)

    Dirksz, D.A.; Scherpen, J.M.A.; van der Schaft, A.J.; Steinbuch, M.

    2012-01-01

    In this paper a standard notch filter is modeled in the port-Hamiltonian framework. By having such a port-Hamiltonian description it is proven that the notch filter is a passive system. The notch filter can then be interconnected with another (nonlinear) port-Hamiltonian system, while preserving the

  19. RETENTION OF SULFUR DIOXIDE BY NYLON FILTERS

    Science.gov (United States)

    Based on laboratory studies, recovery efficiencies of sulfur dioxide (SO2) were determined for nylon filters. The nylon filters used in these experiments were found to retain SO2. A relatively uniform amount (1.7%) was recoverable from each nylon filter, independent of relative...

  20. Filtering algorithm for dotted interferences

    Energy Technology Data Exchange (ETDEWEB)

    Osterloh, K., E-mail: kurt.osterloh@bam.de [Federal Institute for Materials Research and Testing (BAM), Division VIII.3, Radiological Methods, Unter den Eichen 87, 12205 Berlin (Germany); Buecherl, T.; Lierse von Gostomski, Ch. [Technische Universitaet Muenchen, Lehrstuhl fuer Radiochemie, Walther-Meissner-Str. 3, 85748 Garching (Germany); Zscherpel, U.; Ewert, U. [Federal Institute for Materials Research and Testing (BAM), Division VIII.3, Radiological Methods, Unter den Eichen 87, 12205 Berlin (Germany); Bock, S. [Technische Universitaet Muenchen, Lehrstuhl fuer Radiochemie, Walther-Meissner-Str. 3, 85748 Garching (Germany)

    2011-09-21

    An algorithm has been developed to remove reliably dotted interferences impairing the perceptibility of objects within a radiographic image. This particularly is a major challenge encountered with neutron radiographs collected at the NECTAR facility, Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II): the resulting images are dominated by features resembling a snow flurry. These artefacts are caused by scattered neutrons, gamma radiation, cosmic radiation, etc. all hitting the detector CCD directly in spite of a sophisticated shielding. This makes such images rather useless for further direct evaluations. One approach to resolve this problem of these random effects would be to collect a vast number of single images, to combine them appropriately and to process them with common image filtering procedures. However, it has been shown that, e.g. median filtering, depending on the kernel size in the plane and/or the number of single shots to be combined, is either insufficient or tends to blur sharp lined structures. This inevitably makes a visually controlled processing image by image unavoidable. Particularly in tomographic studies, it would be by far too tedious to treat each single projection by this way. Alternatively, it would be not only more comfortable but also in many cases the only reasonable approach to filter a stack of images in a batch procedure to get rid of the disturbing interferences. The algorithm presented here meets all these requirements. It reliably frees the images from the snowy pattern described above without the loss of fine structures and without a general blurring of the image. It consists of an iterative, within a batch procedure parameter free filtering algorithm aiming to eliminate the often complex interfering artefacts while leaving the original information untouched as far as possible.

  1. Radar data smoothing filter study

    Science.gov (United States)

    White, J. V.

    1984-01-01

    The accuracy of the current Wallops Flight Facility (WFF) data smoothing techniques for a variety of radars and payloads is examined. Alternative data reduction techniques are given and recommendations are made for improving radar data processing at WFF. A data adaptive algorithm, based on Kalman filtering and smoothing techniques, is also developed for estimating payload trajectories above the atmosphere from noisy time varying radar data. This algorithm is tested and verified using radar tracking data from WFF.

  2. Design rules for dislocation filters

    OpenAIRE

    Ward, Tom; Sánchez, Ana M; Tang, Mingchu; Wu, Jiang; Liu, Huiyun; Dunstan, David J.; Beanland, Richard

    2014-01-01

    The efficacy of strained layer threading dislocation filter structures in single crystal epitaxial layers is evaluated using numerical modeling for (001) face-centred cubic materials, such as GaAs or Si(1-x)Ge(x), and (0001) hexagonal materials such as GaN. We find that threading dislocation densities decay exponentially as a function of the strain relieved, irrespective of the fraction of threading dislocations that are mobile. Reactions between threading dislocations tend to produce a popul...

  3. Social Collaborative Filtering by Trust.

    Science.gov (United States)

    Yang, Bo; Lei, Yu; Liu, Jiming; Li, Wenjie

    2017-08-01

    Recommender systems are used to accurately and actively provide users with potentially interesting information or services. Collaborative filtering is a widely adopted approach to recommendation, but sparse data and cold-start users are often barriers to providing high quality recommendations. To address such issues, we propose a novel method that works to improve the performance of collaborative filtering recommendations by integrating sparse rating data given by users and sparse social trust network among these same users. This is a model-based method that adopts matrix factorization technique that maps users into low-dimensional latent feature spaces in terms of their trust relationship, and aims to more accurately reflect the users reciprocal influence on the formation of their own opinions and to learn better preferential patterns of users for high-quality recommendations. We use four large-scale datasets to show that the proposed method performs much better, especially for cold start users, than state-of-the-art recommendation algorithms for social collaborative filtering based on trust.

  4. Performance testing of HEPA filters: Progress towards a European standard procedure

    Energy Technology Data Exchange (ETDEWEB)

    Dyment, J.

    1997-08-01

    Proposals for a future European testing procedure for {open_quotes}High Efficiency Particulate Air Filters (HEPA and ULPA){close_quotes} are being developed by CEN (Comite Europeen de Normalisation). The new standard will be given the status of national standard in participating countries, conflicting national standards being withdrawn. The standard will comprise 5 parts covering the grouping and classification of HEPA and ULPA filters according to their efficiency, fundamental principles of testing, marking etc (in part 1). Part 2 will cover aerosol production, measurement principles, counting equipment and statistics. Parts 3-5 will cover testing flat sheet media, leak testing of filter elements and the efficiency testing of filter elements respectively. The efficiency test methods allow the use of either homogeneous monodisperse or polydisperse aerosols for the determination of particulate filtration efficiencies as a function of particle size. The particle size at which maximum penetration occurs is first determined in flat sheet media tests; tests on filter elements (constructed using the same filter medium) may be carried out using either a homogeneous monodisperse aerosol of the size at which maximum penetration occurs (MPPS) or a polydisperse aerosol whose median size is close to the MPPS. Tests with monodisperse aerosols may be conducted using condensation nucleus counting equipment; tests using polydisperse test aerosols require the use of optical sizing particle counters. When determining the efficiency of filter elements the downstream aerosol concentrations may be determined from air samples obtained using either an overall method (single point sampling after mixing) or a scan method. The scan method also allows {open_quotes}local{close_quotes} efficiency values to be determined. 1 ref., 1 fig., 1 tab.

  5. Photoshop Elements 12 all-in-one for dummies

    CERN Document Server

    Obermeier, Barbara

    2013-01-01

    9 books in 1 Getting Started with ElementsOrganizer FundamentalsImage EssentialsSelectionsPainting, Drawing, and TypingWorking with Layers and MasksFilters, Effects, Styles, and DistortionsRetouching and EnhancingCreating and Sharing with Elements Create extraordinary photos with Photoshop Elements 12 and this friendly guide! These days, we're practically never without a camera at hand - even if it's just a cellphone. Whatever you shoot with, Photoshop Elements can help you make your shots look their best. The nine easy-to-follow minibooks in this guide will help you organize, edit, create, a

  6. Filter bed systems treating domestic wastewater in the Nordic countries - Performance and reuse of filter media

    DEFF Research Database (Denmark)

    Jenssen, Petter D.; Krogstad, T.; Paruch, A.M.

    2010-01-01

    Nine filter beds have been constructed in the Nordic countries, Denmark, Finland, Norway and Sweden. Filter beds consist of a septic tank followed by an aerobic pre-treatment biofilter and a subsequent saturated flow grass-covered filter. Thus, filter beds are similar to subsurface flow construct...

  7. Switchable microwave photonic filter between high Q bandpass filter and notch filter with flat passband based on phase modulation.

    Science.gov (United States)

    Yu, Yuan; Xu, Enming; Dong, Jianji; Zhou, Lina; Li, Xiang; Zhang, Xinliang

    2010-11-22

    We propose and demonstrate a novel switchable microwave photonic filter based on phase modulation. Both a microwave high Q bandpass filter and a microwave notch filter with flat passband are achieved respectively. And the switchability between them by tuning the two tunable optical bandpass filters is demonstrated. We also present a theoretical model and analytical expression for the proposed scheme. A frequency response of a high Q bandpass filter with a Q factor of 327 and a rejection ratio of exceeding 42 dB, and a frequency response of a notch filter with flat passband with a rejection ratio exceeding 34 dB are experimentally obtained. The operation frequency of microwave photonic filter is around 20 GHz.

  8. Compact tunable microwave filter using retroreflective acousto-optic filtering and delay controls.

    Science.gov (United States)

    Riza, Nabeel A; Ghauri, Farzan N

    2007-03-01

    Programmable broadband rf filters are demonstrated using a compact retroreflective optical design with an acousto-optic tunable filter and a chirped fiber Bragg grating. This design enables fast 34 micros domain analog-mode control of rf filter time delays and weights. Two proof-of-concept filters are demonstrated including a two-tap notch filter with >35 dB notch depth and a four-tap bandpass filter. Both filters have 2-8 GHz tunability and a 34 micros reset time.

  9. The use of cyclone filters to reduce the foreign matter insertion into the reactor pressure vessel; Einsatz von Zyklonabscheidern zur Verringerung eines Fremdkoerpereintrags in den Reaktordruckbehaelter

    Energy Technology Data Exchange (ETDEWEB)

    Widmann, W. [Westinghouse Electric Germany GmbH, Mannheim (Germany)

    2010-05-15

    Fuel element damage can induce a significant disturbance of the normal NPP operation. Foreign matter insertion into the reactor pressure vessel by the feed water pipes is supposed to be the main cause for fuel element damage in boiling water reactors. Vattenfall AB and Westinghouse Electric Sweden AB have developed a cyclone filter for nuclear facilities. The operational experience of cyclone filters in the feedwater line have reduced the fuel element damages significantly. Westinghouse Electric Germany is performing a feasibility study for the implementation of cyclone filter in the NPP Kruemmel.

  10. The digital TV filter and nonlinear denoising.

    Science.gov (United States)

    Chan, T F; Osher, S; Shen, J

    2001-01-01

    Motivated by the classical TV (total variation) restoration model, we propose a new nonlinear filter-the digital TV filter for denoising and enhancing digital images, or more generally, data living on graphs. The digital TV filter is a data dependent lowpass filter, capable of denoising data without blurring jumps or edges. In iterations, it solves a global total variational (or L(1)) optimization problem, which differs from most statistical filters. Applications are given in the denoising of one dimensional (1-D) signals, two-dimensional (2-D) data with irregular structures, gray scale and color images, and nonflat image features such as chromaticity.

  11. Topology optimization of microwave waveguide filters

    DEFF Research Database (Denmark)

    Aage, Niels; Johansen, Villads Egede

    2017-01-01

    We present a density based topology optimization approach for the design of metallic microwave insert filters. A two-phase optimization procedure is proposed in which we, starting from a uniform design, first optimize to obtain a set of spectral varying resonators followed by a band gap...... little resemblance to standard filter layouts and hence the proposed design method offers a new design tool in microwave engineering....... optimization for the desired filter characteristics. This is illustrated through numerical experiments and comparison to a standard band pass filter design. It is seen that the carefully optimized topologies can sharpen the filter characteristics and improve performance. Furthermore, the obtained designs share...

  12. Topology optimization of microwave waveguide filters

    Science.gov (United States)

    Aage, N.; Egede Johansen, V.

    2017-10-01

    We present a density based topology optimization approach for the design of metallic microwave insert filters. A two-phase optimization procedure is proposed in which we, starting from a uniform design, first optimize to obtain a set of spectral varying resonators followed by a band gap optimization for the desired filter characteristics. This is illustrated through numerical experiments and comparison to a standard band pass filter design. It is seen that the carefully optimized topologies can sharpen the filter characteristics and improve performance. Furthermore, the obtained designs share little resemblance to standard filter layouts and hence the proposed design method offers a new design tool in microwave engineering.

  13. Adaptable Iterative and Recursive Kalman Filter Schemes

    Science.gov (United States)

    Zanetti, Renato

    2014-01-01

    Nonlinear filters are often very computationally expensive and usually not suitable for real-time applications. Real-time navigation algorithms are typically based on linear estimators, such as the extended Kalman filter (EKF) and, to a much lesser extent, the unscented Kalman filter. The Iterated Kalman filter (IKF) and the Recursive Update Filter (RUF) are two algorithms that reduce the consequences of the linearization assumption of the EKF by performing N updates for each new measurement, where N is the number of recursions, a tuning parameter. This paper introduces an adaptable RUF algorithm to calculate N on the go, a similar technique can be used for the IKF as well.

  14. An overview on hybrid active filters

    Energy Technology Data Exchange (ETDEWEB)

    Libano, Fausto B.; Uceda, Javier [Universidad Politecnica de Madrid (Spain). Division de Ingenieria Electronica; Simonetti, Domingos S.L. [Espirito Santo Univ., Vitoria, ES (Brazil). Dept. de Engenharia Eletrica

    1995-12-31

    This paper summarizes the main hybrid filter methods. A special attention is given to series active filter associations. Nowadays, an hybrid filtering is the preferred choice to improve line performance when feeding high-power non-linear loads. In addition, the use of an independent reference frame leads to a better response comparing to the initial proposition of p-q theory. A comparison of possible filter associations is given, presenting the expected function of each one. The work represents an interesting overview on the state-of-the-art of hybrid filters. (author) 16 refs., 8 figs., 2 tabs.

  15. Tunable Bragg filters based on polymer swelling.

    Science.gov (United States)

    Mönch, Wolfgang; Dehnert, Jan; Prucker, Oswald; Rühe, Jürgen; Zappe, Hans

    2006-06-20

    We report on the optical properties of Bragg mirrors and filters fabricated from photo-cross-linked standard optical polymers. The transmittance spectra of these devices in the visible to near-infrared spectral range were measured. We demonstrate efficient tuning of the filter peak of the polymer Bragg filters over several hundred nanometers by adding organic solvents to the surrounding atmosphere of the filter. This represents what we believe to be a novel tuning principle for Bragg filters relying on the use of polymeric materials.

  16. Tunable electro-optic filter stack

    Energy Technology Data Exchange (ETDEWEB)

    Fontecchio, Adam K.; Shriyan, Sameet K.; Bellingham, Alyssa

    2017-09-05

    A holographic polymer dispersed liquid crystal (HPDLC) tunable filter exhibits switching times of no more than 20 microseconds. The HPDLC tunable filter can be utilized in a variety of applications. An HPDLC tunable filter stack can be utilized in a hyperspectral imaging system capable of spectrally multiplexing hyperspectral imaging data acquired while the hyperspectral imaging system is airborne. HPDLC tunable filter stacks can be utilized in high speed switchable optical shielding systems, for example as a coating for a visor or an aircraft canopy. These HPDLC tunable filter stacks can be fabricated using a spin coating apparatus and associated fabrication methods.

  17. Linear Regression Based Real-Time Filtering

    Directory of Open Access Journals (Sweden)

    Misel Batmend

    2013-01-01

    Full Text Available This paper introduces real time filtering method based on linear least squares fitted line. Method can be used in case that a filtered signal is linear. This constraint narrows a band of potential applications. Advantage over Kalman filter is that it is computationally less expensive. The paper further deals with application of introduced method on filtering data used to evaluate a position of engraved material with respect to engraving machine. The filter was implemented to the CNC engraving machine control system. Experiments showing its performance are included.

  18. Grating lobe reduction in transducer arrays through structural filtering of supercritical plates

    Science.gov (United States)

    Anderson, Brian Eric

    The effect of placing a structural acoustic filter between the water medium and the transducer elements of an array is investigated, in this thesis, to help reduce undesirable grating lobes. A plate is mounted to transducer elements with a thin decoupling polyurethane layer between the transducers and the plate. The plate acts as a radiation/incidence angle filter to pass energy at angles near normal incidence, but suppress energy at large incidence angles. The plate must possess a very high bending stiffness while maintaining low mass to achieve optimal results. Grating lobe reduction is achieved at the expense of limiting the available steering of the main lobe. Within this steer angle limit the main lobe beams can be steered as normal while the grating lobe level is reduced by the plate's angular filtering. The insertion of a plate structural filter provides an inexpensive and easily implemented approach to extend usable frequency bandwidth with reduced level grating lobes, without increasing the number of array elements. Even though some data matches theory well, a practical material has yet to be found that possesses optimal material properties. To the author's knowledge, this thesis represents the first attempt to advantageously utilize a plate to provide angular dependent sound transmission filtering above the plate's critical frequency (the supercritical frequency region). Theoretical analysis, numerical analysis, and extensive experimental results have been performed and a comparison will be presented in this thesis. The angular dependence of sound transmission through a plate is reviewed, followed by design considerations to optimize a plate for angular filtering. The optimal thickness for a plate depends on the plate's material properties. Equivalent circuit modeling and finite element modeling was applied, and is compared to. Extensive experimental results conducted with bars and a plate will be shown. Good agreement with theory and modeling is achieved

  19. Copper deficiency can limit nitrification in biological rapid sand filters for drinking water production.

    Science.gov (United States)

    Wagner, Florian B; Nielsen, Peter Borch; Boe-Hansen, Rasmus; Albrechtsen, Hans-Jørgen

    2016-05-15

    Incomplete nitrification in biological filters during drinking water treatment is problematic, as it compromises drinking water quality. Nitrification problems can be caused by a lack of nutrients for the nitrifying microorganisms. Since copper is an important element in one of the essential enzymes in nitrification, we investigated the effect of copper dosing on nitrification in different biological rapid sand filters treating groundwater. A lab-scale column assay with filter material from a water works demonstrated that addition of a trace metal mixture, including copper, increased ammonium removal compared to a control without addition. Subsequently, another water works was investigated in full-scale, where copper influent concentrations were below 0.05 μg Cu L(-1) and nitrification was incomplete. Copper dosing of less than 5 μg Cu L(-1) to a full-scale filter stimulated ammonium removal within one day, and doubled the filter's removal from 0.22 to 0.46 g NH4-N m(-3) filter material h(-1) within 20 days. The location of ammonium and nitrite oxidation shifted upwards in the filter, with an almost 14-fold increase in ammonium removal rate in the filter's top 10 cm, within 57 days of dosing. To study the persistence of the stimulation, copper was dosed to another filter at the water works for 42 days. After dosing was stopped, nitrification remained complete for at least 238 days. Filter effluent concentrations of up to 1.3 μg Cu L(-1) confirmed that copper fully penetrated the filters, and determination of copper content on filter media revealed a buildup of copper during dosing. The amount of copper stored on filter material gradually decreased after dosing stopped; however at a slower rate than it accumulated. Continuous detection of copper in the filter effluent confirmed a release of copper to the bulk phase. Overall, copper dosing to poorly performing biological rapid sand filters increased ammonium removal rates significantly, achieving effluent

  20. Trace Elements and Residual Elements in Superalloys,

    Science.gov (United States)

    Trace elements , *Superalloys, Impurities, Nickel alloys, Refining, Refractory materials, Gases, Residuals, Porosity, Nonmetals, Metals, Metalloids, Segregation(Metallurgy), Auger electron spectroscopy, Fracture(Mechanics), Symposia

  1. Analog Electronic Filters Theory, Design and Synthesis

    CERN Document Server

    Dimopoulos, Hercules G

    2012-01-01

    Filters are essential subsystems in a huge variety of electronic systems. Filter applications are innumerable; they are used for noise reduction, demodulation, signal detection, multiplexing, sampling, sound and speech processing, transmission line equalization and image processing, to name just a few. In practice, no electronic system can exist without filters. They can be found in everything from power supplies to mobile phones and hard disk drives and from loudspeakers and MP3 players to home cinema systems and broadband Internet connections. This textbook introduces basic concepts and methods and the associated mathematical and computational tools employed in electronic filter theory, synthesis and design.  This book can be used as an integral part of undergraduate courses on analog electronic filters. Includes numerous, solved examples, applied examples and exercises for each chapter. Includes detailed coverage of active and passive filters in an independent but correlated manner. Emphasizes real filter...

  2. UV filters for lighting of plants

    Energy Technology Data Exchange (ETDEWEB)

    Doehring, T.; Koefferlein, M.; Thiel, S.; Seidlitz, H.K.; Payer, H.D. [GSF-Forschungszentrum fuer Umwelt und Gesundheit GmbH, Oberschleissheim (Germany)

    1994-12-31

    Different filter glasses are available which provide absorption properties suitable for gradual changes of the spectral UV-B illumination of artificial lighting. Using a distinct set of lamps and filter glasses an acceptable simulation of the UV-B part of natural global radiation can be achieved. The ageing of these and other filter materials under the extreme UV radiation in the lamphouse of a solar simulator is presently unavoidable. This instability can be dealt with only by a precise spectral monitoring and by replacing the filters accordingly. For this reason attempts would be useful to develop real ozone filters which can replace glass filters. In any case chamber experiments require a careful selection of the filter material used and must be accompanied by a continuous UV-B monitoring.

  3. Signal enhancement with variable span linear filters

    CERN Document Server

    Benesty, Jacob; Jensen, Jesper R

    2016-01-01

    This book introduces readers to the novel concept of variable span speech enhancement filters, and demonstrates how it can be used for effective noise reduction in various ways. Further, the book provides the accompanying Matlab code, allowing readers to easily implement the main ideas discussed. Variable span filters combine the ideas of optimal linear filters with those of subspace methods, as they involve the joint diagonalization of the correlation matrices of the desired signal and the noise. The book shows how some well-known filter designs, e.g. the minimum distortion, maximum signal-to-noise ratio, Wiener, and tradeoff filters (including their new generalizations) can be obtained using the variable span filter framework. It then illustrates how the variable span filters can be applied in various contexts, namely in single-channel STFT-based enhancement, in multichannel enhancement in both the time and STFT domains, and, lastly, in time-domain binaural enhancement. In these contexts, the properties of ...

  4. Filter for isotopic alteration of mercury vapor

    Science.gov (United States)

    Grossman, Mark W.; George, William A.

    1989-01-01

    A filter for enriching the .sup.196 Hg content of mercury, including a reactor, a low pressure electric discharge lamp containing a fill of mercury and an inert gas. A filter is arranged concentrically around the lamp. The reactor is arranged around said filter, whereby radiation from said lamp passes through the filter and into said reactor. The lamp, the filter and the reactor are formed of quartz, and are transparent to ultraviolet light. The .sup.196 Hg concentration in the mercury fill is less than that which is present in naturally occurring mercury, that is less than about 0.146 atomic weight percent. Hydrogen is also included in the fill and serves as a quenching gas in the filter, the hydrogen also serving to prevent disposition of a dark coating on the interior of the filter.

  5. Signal Enhancement with Variable Span Linear Filters

    DEFF Research Database (Denmark)

    Benesty, Jacob; Christensen, Mads Græsbøll; Jensen, Jesper Rindom

    This book introduces readers to the novel concept of variable span speech enhancement filters, and demonstrates how it can be used for effective noise reduction in various ways. Further, the book provides the accompanying Matlab code, allowing readers to easily implement the main ideas discussed....... Variable span filters combine the ideas of optimal linear filters with those of subspace methods, as they involve the joint diagonalization of the correlation matrices of the desired signal and the noise. The book shows how some well-known filter designs, e.g. the minimum distortion, maximum signal......-to-noise ratio, Wiener, and tradeoff filters (including their new generalizations) can be obtained using the variable span filter framework. It then illustrates how the variable span filters can be applied in various contexts, namely in single-channel STFT-based enhancement, in multichannel enhancement in both...

  6. Merging particle filter for sequential data assimilation

    Directory of Open Access Journals (Sweden)

    S. Nakano

    2007-07-01

    Full Text Available A new filtering technique for sequential data assimilation, the merging particle filter (MPF, is proposed. The MPF is devised to avoid the degeneration problem, which is inevitable in the particle filter (PF, without prohibitive computational cost. In addition, it is applicable to cases in which a nonlinear relationship exists between a state and observed data where the application of the ensemble Kalman filter (EnKF is not effectual. In the MPF, the filtering procedure is performed based on sampling of a forecast ensemble as in the PF. However, unlike the PF, each member of a filtered ensemble is generated by merging multiple samples from the forecast ensemble such that the mean and covariance of the filtered distribution are approximately preserved. This merging of multiple samples allows the degeneration problem to be avoided. In the present study, the newly proposed MPF technique is introduced, and its performance is demonstrated experimentally.

  7. A New Formulation of the Filter-Error Method for Aerodynamic Parameter Estimation in Turbulence

    Science.gov (United States)

    Grauer, Jared A.; Morelli, Eugene A.

    2015-01-01

    A new formulation of the filter-error method for estimating aerodynamic parameters in nonlinear aircraft dynamic models during turbulence was developed and demonstrated. The approach uses an estimate of the measurement noise covariance to identify the model parameters, their uncertainties, and the process noise covariance, in a relaxation method analogous to the output-error method. Prior information on the model parameters and uncertainties can be supplied, and a post-estimation correction to the uncertainty was included to account for colored residuals not considered in the theory. No tuning parameters, needing adjustment by the analyst, are used in the estimation. The method was demonstrated in simulation using the NASA Generic Transport Model, then applied to the subscale T-2 jet-engine transport aircraft flight. Modeling results in different levels of turbulence were compared with results from time-domain output error and frequency- domain equation error methods to demonstrate the effectiveness of the approach.

  8. Direct quantification of airborne nanoparticles composition by TXRF after collection on filters

    Energy Technology Data Exchange (ETDEWEB)

    Motellier, S; Lhaute, K; Guiot, A; Golanski, L; Tardif, F [CEA Grenoble, DRT, LITEN, DTNM, Laboratory of Nanochemistry and Nanosafety, 17 Avenue des Martyrs, Cedex 9, F-38054 Grenoble (France); Geoffroy, C, E-mail: sylvie.motellier@cea.fr [Elexience, 9 rue des petits ruisseaux, BP 61, 91371 Verrieres-le-Buisson Cedex (France)

    2011-07-06

    Direct TXRF analysis of nanoparticles deposited on filters was evaluated. Standard filters spiked with known amounts of NP were produced using an atomizer which generates an aerosol from a NP containing-liquid suspension. Polycarbonate filters provided the highest fluorescence signals and black polycarbonate filters containing chromium were further selected, Cr being used as internal standard for elemental quantification of the filter contaminants. Calibration curves were established for various NP (TiO{sub 2}, ZnO, CeO{sub 2}, Al{sub 2}O{sub 3}). Good linearity was observed. Low limits of detection were in the tens to the hundreds of ngs per filter, the method being less adapted to Al{sub 2}O{sub 3} due to the poor TXRF sensitivity for light elements. The analysis of MW-CNTs was attempted by quantification of their metal (Fe) catalyst impurities. Problems like CNT dispersion in liquids, quantification of the deposited quantity and high Fe-background contamination.

  9. A novel 2nd-order bandpass MFSS filter with miniaturized structure

    Directory of Open Access Journals (Sweden)

    C. Y. Fang

    2015-08-01

    Full Text Available In order to effectively obtain a miniaturized structure and good filtering properties, we propose a novel 2nd-order bandpass metamaterial frequency selective surface (MFSS filter which contains two capacitive layers and one inductive layer, where there are multi-loop metallic patches as shunt capacitor C and planar wire grids as series inductor L respectively. Unlike the traditional operation way—the tuned elements used in resonant surface approximately equal to one wavelength in circumference and the structure thickness with a spacing of a quarter wavelength apart, by changing the value of L and C and matching multilayer dielectric to adjust the LC coupling resonance and the resonance impedance respectively, the proposed MFSS filter can achieves a miniatured structure with ideal bandpass properties. Measurement results of the fabricated prototype of the bandpass filter (BPF indicate that the dimension of the tuned element on resonant surface is approximately 0.025 wavelength, i.e., 0.025λ. At the same time, the filter has the stable center frequency of f0 = 1.53GHz and the transmittance of T ⩾ 96.3% and high Q-value for the TE/TM wave polarization at various incidence angles. The novel 2nd-order bandpass MFSS filter with miniaturized structure not only can decrease structure dimension, but also has a wide range of applications to microwave and infrared band.

  10. Adaptive noise Wiener filter for scanning electron microscope imaging system.

    Science.gov (United States)

    Sim, K S; Teh, V; Nia, M E

    2016-01-01

    Noise on scanning electron microscope (SEM) images is studied. Gaussian noise is the most common type of noise in SEM image. We developed a new noise reduction filter based on the Wiener filter. We compared the performance of this new filter namely adaptive noise Wiener (ANW) filter, with four common existing filters as well as average filter, median filter, Gaussian smoothing filter and the Wiener filter. Based on the experiments results the proposed new filter has better performance on different noise variance comparing to the other existing noise removal filters in the experiments. © Wiley Periodicals, Inc.

  11. Multivariate localization methods for ensemble Kalman filtering

    KAUST Repository

    Roh, S.

    2015-12-03

    In ensemble Kalman filtering (EnKF), the small number of ensemble members that is feasible to use in a practical data assimilation application leads to sampling variability of the estimates of the background error covariances. The standard approach to reducing the effects of this sampling variability, which has also been found to be highly efficient in improving the performance of EnKF, is the localization of the estimates of the covariances. One family of localization techniques is based on taking the Schur (element-wise) product of the ensemble-based sample covariance matrix and a correlation matrix whose entries are obtained by the discretization of a distance-dependent correlation function. While the proper definition of the localization function for a single state variable has been extensively investigated, a rigorous definition of the localization function for multiple state variables that exist at the same locations has been seldom considered. This paper introduces two strategies for the construction of localization functions for multiple state variables. The proposed localization functions are tested by assimilating simulated observations experiments into the bivariate Lorenz 95 model with their help.

  12. A nonlinear filter for high order discontinuous Galerkin discretizations with discontinuity resolution within the cell

    Science.gov (United States)

    Panourgias, Konstantinos T.; Ekaterinaris, John A.

    2016-12-01

    The nonlinear filter introduced by Yee et al. (1999) [27] and extensively used in the development of low dissipative well-balanced high order accurate finite-difference schemes is adapted to the finite element context of discontinuous Galerkin (DG) discretizations. The filter operator is constructed in the canonical computational domain for the standard cubical element where it is applied to the computed conservative variables in a direction per direction basis. Filtering becomes possible for all element types in unstructured meshes using collapsed coordinate transformations. The performance of the proposed nonlinear filter for DG discretizations is demonstrated and evaluated for different orders of expansions for one-dimensional and multidimensional problems with exact solutions. It is shown that for higher order discretizations discontinuity resolution within the cell is achieved and the design order of accuracy is preserved. The filter is applied for a number of standard inviscid flow test problems including strong shocks interactions to demonstrate that the proposed dissipative mechanism for DG discretizations yields superior results compared to the results obtained with the total variation bounded (TVB) limiter and high-order hierarchical limiting. The proposed approach is suitable for p-adaptivity in order to locally enhance resolution of three-dimensional flow simulations that include discontinuities and complex flow features.

  13. Infinte Periodic Structure of Lightweight Elements

    DEFF Research Database (Denmark)

    Domadiya, Parthkumar Gandalal; Andersen, Lars Vabbersgaard; Sorokin, Sergey

    2013-01-01

    . Furthermore, lightweight building elements are typically periodic structures that behave as filters for sound propagation within certain frequency ranges (stop bands), thus only allowing transmission within the pass bands. Hence, traditional methods based on statistical energy analysis cannot be used...... for proper dynamic assessment of lightweight buildings. Instead, this paper discusses and compares the use of finite element analysis and a wave approach based on Floquet theory. The present analysis has focus on the effect of periodicity on vibration transmission within semi-infinite beam structures. Two...... models of a semi-infinite Euler-Bernoulli and Timoshenko beam structure with periodic variation of the cross-sectional properties are analyzed. In case of the Euler-Bernoulli beam, vibrational behavior is studied in two dimensions by finite element analysis and Floquet theory. Wave propagation within...

  14. Split quaternion nonlinear adaptive filtering.

    Science.gov (United States)

    Ujang, Bukhari Che; Took, Clive Cheong; Mandic, Danilo P

    2010-04-01

    A split quaternion learning algorithm for the training of nonlinear finite impulse response adaptive filters for the processing of three- and four-dimensional signals is proposed. The derivation takes into account the non-commutativity of the quaternion product, an aspect neglected in the derivation of the existing learning algorithms. It is shown that the additional information taken into account by a rigorous treatment of quaternion algebra provides improved performance on hypercomplex processes. A rigorous analysis of the convergence of the proposed algorithms is also provided. Simulations on both benchmark and real-world signals support the approach. Copyright 2009 Elsevier Ltd. All rights reserved.

  15. ADVANCED HOT GAS FILTER DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    Matthew R. June; John L. Hurley; Mark W. Johnson

    1999-04-01

    Iron aluminide hot gas filters have been developed using powder metallurgy techniques to form seamless cylinders. Three alloys were short-term corrosion tested in simulated IGCC atmospheres with temperatures between 925 F and 1200 F with hydrogen sulfide concentrations ranging from 783 ppm{sub v} to 78,300 ppm{sub v}. Long-term testing was conducted for 1500 hours at 925 F with 78,300 ppm{sub v}. The FAS and FAL alloys were found to be corrosion resistant in the simulated environments. The FAS alloy has been commercialized.

  16. Visualizing the application of filters

    DEFF Research Database (Denmark)

    Rasmussen, Rasmus; Hertzum, Morten

    2013-01-01

    Through a mixed-design experiment we compare how emergency-department clinicians perform when solving realistic work tasks with an electronic whiteboard where the application of information filters is visualized either by blocking, colour-coding or blurring information. We find that clinicians...... perform significantly faster and with less effort and temporal demand when using the blocking interface. However, we also find that the colour-coding interface provides clinicians with a better overview of the information displayed by the electronic whiteboard. The blurring interface did not perform...

  17. Multi-elemental analysis of atmospheric pollutants and determination of particle size using the PIXE method, a cascade impactor and a filter unit constructed in Mexico; Analisis multielemental de contaminantes atmosfericos y determinacion de tamano de particula utilizando el metodo PIXE, un impactor de cascada y una unidad de filtro construidos en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Aldape U, F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1989-01-15

    This work presents: 1) The methodology and the experimental conditions of the PIXE technique so that it is used as a better option inside the analytical methods in aerosols studies, 2) The development, tests and applications of a cascade impactor of the Batelle type built to determine particle size to use it jointly with the mentioned technique in the determination of the elements concentration according to its size.By this way is fulfilled with the first goal of this extensive project. (Author)

  18. Copper deficiency can limit nitrification in biological rapid sand filters for drinking water production

    DEFF Research Database (Denmark)

    Wagner, Florian Benedikt; Nielsen, Peter Borch; Boe-Hansen, Rasmus

    2016-01-01

    Incomplete nitrification in biological filters during drinking water treatment is problematic, as it compromises drinking water quality. Nitrification problems can be caused by a lack of nutrients for the nitrifying microorganisms. Since copper is an important element in one of the essential...... enzymes in nitrification, we investigated the effect of copper dosing on nitrification in different biological rapid sand filters treating groundwater. A lab-scale column assay with filter material from a water works demonstrated that addition of a trace metal mixture, including copper, increased ammonium...... removal compared to a control without addition. Subsequently, another water works was investigated in full-scale, where copper influent concentrations were below 0.05 μg Cu L-1 and nitrification was incomplete. Copper dosing of less than 5 μg Cu L-1 to a full-scale filter stimulated ammonium removal...

  19. Research on the method of information system risk state estimation based on clustering particle filter

    Science.gov (United States)

    Cui, Jia; Hong, Bei; Jiang, Xuepeng; Chen, Qinghua

    2017-05-01

    With the purpose of reinforcing correlation analysis of risk assessment threat factors, a dynamic assessment method of safety risks based on particle filtering is proposed, which takes threat analysis as the core. Based on the risk assessment standards, the method selects threat indicates, applies a particle filtering algorithm to calculate influencing weight of threat indications, and confirms information system risk levels by combining with state estimation theory. In order to improve the calculating efficiency of the particle filtering algorithm, the k-means cluster algorithm is introduced to the particle filtering algorithm. By clustering all particles, the author regards centroid as the representative to operate, so as to reduce calculated amount. The empirical experience indicates that the method can embody the relation of mutual dependence and influence in risk elements reasonably. Under the circumstance of limited information, it provides the scientific basis on fabricating a risk management control strategy.

  20. Dye and pigment-free structural colors and angle-insensitive spectrum filters

    Science.gov (United States)

    Guo, Lingjie Jay; Hollowell, Andrew E.; Wu, Yi-Kuei

    2017-01-17

    Optical spectrum filtering devices displaying minimal angle dependence or angle insensitivity are provided. The filter comprises a localized plasmonic nanoresonator assembly having a metal material layer defining at least one nanogroove and a dielectric material disposed adjacent to the metal material layer. The dielectric material is disposed within the nanogroove(s). The localized plasmonic nanoresonator assembly is configured to funnel and absorb a portion of an electromagnetic spectrum in the at least one nanogroove via localized plasmonic resonance to generate a filtered output having a predetermined range of wavelengths that displays angle insensitivity. Thus, flexible, high efficiency angle independent color filters having very small diffraction limits are provided that are particularly suitable for use as pixels for various display devices or for use in anti-counterfeiting and cryptography applications. The structures can also be used for colored print applications and the elements can be rendered as pigment-like particles.