WorldWideScience

Sample records for based inert matrix

  1. Reprocessability of molybdenum and magnesia based inert matrix fuels

    Directory of Open Access Journals (Sweden)

    Ebert Elena L.

    2015-12-01

    Full Text Available This work focuses on the reprocessability of metallic 92Mo and ceramic MgO, which is under investigation for (Pu,MA-oxide (MA = minor actinide fuel within a metallic 92Mo matrix (CERMET and a ceramic MgO matrix (CERCER. Magnesium oxide and molybdenum reference samples have been fabricated by powder metallurgy. The dissolution of the matrices was studied as a function of HNO3 concentration (1-7 mol/L and temperature (25-90°C. The rate of dissolution of magnesium oxide and metallic molybdenum increased with temperature. While the MgO rate was independent of the acid concentration (1-7 mol/L, the rate of dissolution of Mo increased with acid concentration. However, the dissolution of Mo at high temperatures and nitric acid concentrations was accompanied by precipitation of MoO3. The extraction of uranium, americium, and europium in the presence of macro amounts of Mo and Mg was studied by three different extraction agents: tri-n-butylphosphate (TBP, N,Nʹ-dimethyl-N,Nʹ-dioctylhexylethoxymalonamide (DMDOHEMA, and N,N,N’,N’- -tetraoctyldiglycolamide (TODGA. With TBP no extraction of Mo and Mg occurred. Both matrix materials are partly extracted by DMDOHEMA. Magnesium is not extracted by TODGA (D < 0.1, but a weak extraction of Mo is observed at low Mo concentration.

  2. Fabrication and characterization of dysprosia and alumina based inert matrix neutron absorbers

    International Nuclear Information System (INIS)

    D Ovidio, C.; Oliber, E.; Leiva, S.; Malachevsky, M. T; Taboada, H

    2009-01-01

    Among the elements of the lanthanides series, dysprosium has interesting nuclear properties. Its high thermal neutron absorption cross-section makes it a good neutron absorber. The best ceramic compound apt for nuclear use is its oxide, the disprosia (Dy 2 O 3 ). In order to fabricate neutron absorbers diluted in an inert matrix, it is relevant to study the preparation of a ceramic compound based on alumina (Al 2 O 3 ) and disprosia. In this work, we characterize a particular composition (44,5wt% Dy 2 O 3 , 55,5wt% Al 2 O 3 ) by determining the geometrical density, microstructure and phase formation. The chosen composition corresponds to the lowest temperature eutectic of the alumina-disprosia system, allowing the sintering to proceed at 1700 oC in air. Comparing the data of the green and sinterized pellets, the relative shrinking is of about 17 %, in the same proportion both for diameter and length. The corresponding volumetric reduction is of about 43 %, indicating an increase of the relative geometric density of ∼ 70 %. X-ray diffraction analysis shows the existence of two phases corresponding to the lower eutectic: Dy 3 Al 5 O 1 2 and Al 2 O 3 . The calculated theoretical density is ∼ 5.2 g/cm3. Consequently, the relative density of the pellets is 92 %, indicating the feasibility for the fabrication of the proposed material. In a near future, samples will be irradiated to evaluate their behavior for nuclear use. [es

  3. The Optimum Plutonium Inert Matrix Fuel Form for Reactor-Based Plutonium Disposition

    International Nuclear Information System (INIS)

    Tulenko, J.S.; Wang, J.; Acosta, C.

    2004-01-01

    The University of Florida has underway an ongoing research program to validate the economic, operational and performance benefits of developing an inert matrix fuel (IMF) for the disposition of the U.S. weapons plutonium (Pu) and for the recycle of reprocessed Pu. The current fuel form of choice for Pu disposition for the Department of Energy is as a mixed oxide (MOX) (PuO2/UO2). We will show analyses that demonstrate that a Silicon Carbide (SiC) IMF offers improved performance capabilities as a fuel form for Pu recycle and disposition. The reason that UF is reviewing various materials to serve as an inert matrix fuel is that an IMF fuel form can offer greatly reduced Pu and transuranic isotope (TRU) production and also improved thermal performance characteristics. Our studies showed that the Pu content is reduced by an order of magnitude while centerline fuel temperatures are reduced approximately 380 degrees centigrade compared to MOX. These reduced temperatures result in reduced stored heat and thermal stresses in the pellet. The reduced stored heat reduces the consequences of the loss of coolant accident, while the reduced temperatures and thermal stresses yield greatly improved fuel performance. Silicon Carbide is not new to the nuclear industry, being a basic fuel material in gas cooled reactors

  4. Kinetic Modelling of Drug Release from Pentoxifylline Matrix Tablets based on Hydrophilic, Lipophilic and Inert Polymers

    Directory of Open Access Journals (Sweden)

    Mircia Eleonora

    2015-12-01

    Full Text Available Pentoxifylline is a xanthine derivative used in the treatment of peripheral vascular disease, which because of its pharmacokinetic and pharmacologic profile is an ideal candidate for the development of extended release formulations. The aim of this study is to present a kinetic analysis of the pentoxifylline release from different extended release tablets formulations, using mechanistic and empirical kinetic models. A number of 28 formulations were prepared and analysed; the analysed formulations differed in the nature of the matrix forming polymers (hydrophilic, lipophilic, inert and in their concentrations. Measurements were conducted in comparison with the reference product Trental 400 mg (Aventis Pharma. The conditions for the dissolution study were according to official regulations of USP 36: apparatus no. 2, dissolution medium water, volume of dissolution medium is 1,000 mL, rotation speed is 50 rpm, spectrophotometric assay at 274 nm. Six mathematical models, five mechanistic (0 orders, 1st-order release, Higuchi, Hopfenberg, Hixson-Crowell and one empirical (Peppas, were fitted to pentoxifylline dissolution profile from each pharmaceutical formulation. The representative model describing the kinetics of pentoxifylline release was the 1st-order release, and its characteristic parameters were calculated and analysed.

  5. Reducing Actinide Production Using Inert Matrix Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Deinert, Mark [Colorado School of Mines, Golden, CO (United States)

    2017-08-23

    The environmental and geopolitical problems that surround nuclear power stem largely from the longlived transuranic isotopes of Am, Cm, Np and Pu that are contained in spent nuclear fuel. New methods for transmuting these elements into more benign forms are needed. Current research efforts focus largely on the development of fast burner reactors, because it has been shown that they could dramatically reduce the accumulation of transuranics. However, despite five decades of effort, fast reactors have yet to achieve industrial viability. A critical limitation to this, and other such strategies, is that they require a type of spent fuel reprocessing that can efficiently separate all of the transuranics from the fission products with which they are mixed. Unfortunately, the technology for doing this on an industrial scale is still in development. In this project, we explore a strategy for transmutation that can be deployed using existing, current generation reactors and reprocessing systems. We show that use of an inert matrix fuel to recycle transuranics in a conventional pressurized water reactor could reduce overall production of these materials by an amount that is similar to what is achievable using proposed fast reactor cycles. Furthermore, we show that these transuranic reductions can be achieved even if the fission products are carried into the inert matrix fuel along with the transuranics, bypassing the critical separations hurdle described above. The implications of these findings are significant, because they imply that inert matrix fuel could be made directly from the material streams produced by the commercially available PUREX process. Zirconium dioxide would be an ideal choice of inert matrix in this context because it is known to form a stable solid solution with both fission products and transuranics.

  6. Status of the inert matrix fuel program at PSI

    International Nuclear Information System (INIS)

    Ledergerber, G.; Degueldre, C.; Kasemeyer, U.; Stanculescu, A.; Paratte, J.M.; Chawla, R.

    1997-01-01

    Incineration of plutonium by a once-through cycle in LWRs utilising an inert matrix based fuel may prove to be an attractive way of making use of the energy of fissile plutonium and reducing both the hazard potential and the volumes of the waste. Yttria stabilised zirconia forms a solid solution with oxides of rare earth elements (e.g. erbium, cerium) and some actinides. The small absorption cross section, the excellent stability under irradiation, and the insolubility in acids and water recommends this material as an inert matrix. Neutronics calculations with erbium as burnable poison show that these compositions would be optimal from the reactivity point of view. A fuel element with an improved reactivity behaviour over its life cycle has been designed for possible introduction into a heterogeneous LWR core. (author). 16 refs., 1 tab., 10 figs

  7. Inert matrix advantages in the transmutation balance of minor actinides

    Energy Technology Data Exchange (ETDEWEB)

    Prunier, C.; Guerin, Y. [CEA Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. d`Etudes des Combustibles; Zaetta, A.; Tommasi, J. [CEA Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. d`Etudes des Reacteurs

    1995-12-31

    The results of experimental irradiation in relation to the homogeneous concept (UO{sub 2} fuel) with a limited burn-up of 4.5 atom. % have shown that the percentage of the minor actinides Am and Np incinerated reached values of around 25% to 30% - values confirmed by calculations - for irradiation in the Phenix reactor (FR). The calculation and analysis of the quantity of nuclides formed by transmutation, especially plutonium isotopes, are also in close agreement. Using these experimental results, which are supported by the calculations, research on the incineration of minor actinides has been extended to compare the production of plutonium isotopes. Two minor actinide supports are used for this comparison: - a fuel (UO{sub 2} oxide), - an inert matrix (magnesia MgO). In both cases, a content of 45% of minor actinides (Np or Am) by weight is used to represent the heterogeneous recycling mode. Comparison shows the advantage of inert matrices relative to UO{sub 2} fuel to greatly reduce the production of plutonium for the same consumption of minor actinides. A particularly interesting case is that of heterogeneous recycling, which implements americium-based targets (magnesia with 45% americium in the form of AmO{sub 2}), placed on the periphery of the FR core (first row of blankets). (authors). 9 refs., 2 figs., 11 tabs.

  8. Separation of Nuclear Fuel Surrogates from Silicon Carbide Inert Matrix

    International Nuclear Information System (INIS)

    Baney, Ronald

    2008-01-01

    The objective of this project has been to identify a process for separating transuranic species from silicon carbide (SiC). Silicon carbide has become one of the prime candidates for the matrix in inert matrix fuels, (IMF) being designed to reduce plutonium inventories and the long half-lives actinides through transmutation since complete reaction is not practical it become necessary to separate the non-transmuted materials from the silicon carbide matrix for ultimate reprocessing. This work reports a method for that required process

  9. Chromium liquid waste inertization in an inorganic alkali activated matrix: Leaching and NMR multinuclear approach

    Energy Technology Data Exchange (ETDEWEB)

    Ponzoni, Chiara, E-mail: chiara.ponzoni@unimore.it [University of Modena and Reggio Emilia, Department of Engineering “Enzo Ferrari”, Modena (Italy); Lancellotti, Isabella; Barbieri, Luisa [University of Modena and Reggio Emilia, Department of Engineering “Enzo Ferrari”, Modena (Italy); Spinella, Alberto; Saladino, Maria Luisa [University of Palermo CGA-UniNetLab, Palermo (Italy); Martino, Delia Chillura [University of Palermo, Department STEBICEF, Palermo (Italy); Caponetti, Eugenio [University of Palermo CGA-UniNetLab, Palermo (Italy); University of Palermo, Department STEBICEF, Palermo (Italy); Armetta, Francesco [University of Palermo, Department STEBICEF, Palermo (Italy); Leonelli, Cristina [University of Modena and Reggio Emilia, Department of Engineering “Enzo Ferrari”, Modena (Italy)

    2015-04-09

    Highlights: • Inertization of chromium liquid waste in aluminosilicate matrix. • Water less inertization technique exploiting the waste water content. • Liquid waste inertization without drying step. • Long term stabilization study through leaching test. • SEM analysis and {sup 29}Si and {sup 27}Al MAS NMR in relation with long curing time. - Abstract: A class of inorganic binders, also known as geopolymers, can be obtained by alkali activation of aluminosilicate powders at room temperature. The process is affected by many parameters (curing time, curing temperature, relative humidity etc.) and leads to a resistant matrix usable for inertization of hazardous waste. In this study an industrial liquid waste containing a high amount of chromium (≈2.3 wt%) in the form of metalorganic salts is inertized into a metakaolin based geopolymer matrix. One of the innovative aspects is the exploitation of the water contained in the waste for the geopolymerization process. This avoided any drying treatment, a common step in the management of liquid hazardous waste. The evolution of the process - from the precursor dissolution to the final geopolymer matrix hardening - of different geopolymers containing a waste amount ranging from 3 to 20% wt and their capability to inertize chromium cations were studied by: i) the leaching tests, according to the EN 12,457 regulation, at different curing times (15, 28, 90 and 540 days) monitoring releases of chromium ions (Cr(III) and Cr(VI)) and the cations constituting the aluminosilicate matrix (Na, Si, Al); ii) the humidity variation for different curing times (15 and 540 days); iii) SEM characterization at different curing times (28 and 540 days); iv) the trend of the solution conductivity and pH during the leaching test; v) the characterization of the short-range ordering in terms of T−O−T bonds (where T is Al or Si) by {sup 29}Si and {sup 27}Al solid state magic-angle spinning nuclear magnetic resonance (ss MAS NMR) for

  10. Viability of inert matrix fuel in reducing plutonium amounts in reactors

    International Nuclear Information System (INIS)

    2006-08-01

    Reactors worldwide have produced more than 2000 tonnes of plutonium, contained in spent fuel or as separated forms through reprocessing. Disposition of fissile materials has become a primary concern of nuclear non-proliferation efforts. There is a significant interest in IAEA Member States to develop proliferation resistant nuclear fuel cycles for incineration of plutonium such as inert matrix fuels (IMFs). The present report summarises R and D work on inert matrix fuel for plutonium and (to a lesser extent) minor actinide stock-pile reduction, and discusses the possible strategies to include inert matrix fuel approaches to the nuclear fuel cycle. The publication reviews the status of potential IMF candidates and describes several identified candidate materials for both fast and thermal reactors: MgO, ZrO2, SiC, Zr alloy, SiAl, ZrN; some of these have undergone test irradiations and post-irradiation examination. Also discussed are modelling of IMF fuel performance and safety analysis. System studies have identified strategies for both implementation of IMF fuel as homogeneous or heterogeneous phases, as assemblies or core loadings and in existing reactors in the shorter term, as well as in new reactors in the longer term

  11. Zirconium carbonitride pellets by internal sol gel and spark plasma sintering as inert matrix fuel material

    Science.gov (United States)

    Hedberg, Marcus; Cologna, Marco; Cambriani, Andrea; Somers, Joseph; Ekberg, Christian

    2016-10-01

    Inert matrix fuel is a fuel type where the fissile material is blended with a solid diluent material. In this work zirconium carbonitride microspheres have been produced by internal sol gel technique, followed by carbothermal reduction. Material nitride purities in the produced materials ranged from Zr(N0.45C0.55) to Zr(N0.74C0.26) as determined by X-ray diffraction and application of Vegard's law. The zirconium carbonitride microspheres have been pelletized by spark plasma sintering (SPS) and by conventional cold pressing and sintering. In all SPS experiments cohesive pellets were formed. Maximum final density reached by SPS at 1700 °C was 87% theoretical density (TD) compared to 53% TD in conventional sintering at 1700 °C. Pore sizes in all the produced pellets were in the μm scale and no density gradients could be observed by computer tomography.

  12. Inert matrix fuel performance during the first two irradiation cycles in a test reactor: comparison with modelling results

    Science.gov (United States)

    Hellwig, Ch.; Kasemeyer, U.

    2003-06-01

    In the inert matrix fuel (IMF) type investigated at Paul Scherrer Institut, plutonium is dissolved in the yttrium stabilised zirconium oxide (YSZ), a highly radiation resistant cubic phase with additions of erbium as burnable poison for reactivity control. A first irradiation experiment of YSZ based IMF is ongoing in the OECD Material Test Reactor in Halden together with mixed oxide fuel. The results of the first two cycles for IMF to a burnup of some 105 kW d cm -3 are presented and the modelling results in comparison with the experimental results are shown. A first approximation for a simple swelling model for this YSZ based IMF can be given. Possible fission gas release mechanisms are briefly discussed. The implications of the modelling results are discussed.

  13. An electromagnetic inerter-based vibration suppression device

    International Nuclear Information System (INIS)

    Gonzalez-Buelga, A; Clare, L R; Neild, S A; Jiang, J Z; Inman, D J

    2015-01-01

    This paper describes how an inerter-based device for structural vibration suppression can be realized using an electromagnetic transducer such as a linear motor. When the motor shaft moves, a difference of voltage is generated across the transducer coil. The voltage difference is proportional to the relative velocity between its two terminals. The electromagnetic transducer will exert a force proportional to current following the Lorentz principle if the circuit is closed around the transducer coil. If an electronic circuit consisting of a capacitor, an inductance and a resistance with the appropriate configuration is connected, the resulting force reflected back into the mechanical domain is equivalent to that achieved by a mechanical inerter-based device. The proposed configuration is easy to implement and very versatile, provided a high quality conversion system with negligible losses. With the use of electromagnetic devices, a new generation of vibration absorbers can be realized, for example in the electrical domain it would be relatively uncomplicated to synthesize multi-frequency or real time tunable vibration absorbers by adding electrical components in parallel. In addition by using resistance emulators in the electrical circuits, part of the absorbed vibration energy can be converted into usable power. Here an electromagnetic tuned inerter damper (E-TID) is tested experimentally using real time dynamic substructuring. A voltage compensation unit was developed in order to compensate for coil losses. This voltage compensation unit requires power, which is acquired through harvesting from the vibration energy using a resistance emulator. A power balance analysis was developed in order to ensure the device can be self sufficient. Promising experimental results, using this approach, have been obtained and are presented in this paper. The ultimate goal of this research is the development of autonomous electromagnetic vibration absorbers, able to harvest energy

  14. Comparative Study between Two Schemes of Active-Control-Based Mechatronic Inerter

    Directory of Open Access Journals (Sweden)

    He Lingduo

    2017-01-01

    Full Text Available Based on force-current analogy and velocity-voltage analogy in the theory of electromechanical analogy, the inerter is a device that corresponded to the capacitor completely where conquers the nature restriction of mass, what’s more, it is significant to improve the ratio of the inerter’s inertance to its mass for mechanical networks synthesis. And according to the principle of active-control-based mechatronic inerter, we present two implementation schemes. One was based on linear motor, and the other was based on the ball screw and rotary motor. We introduced the implementation methods and established theoretical model of the two schemes, then compared the ratio of the inerter’s inertance to its mass for the two schemes. Finally, we consider the scheme is better which was based on the ball screw and rotary motor.

  15. A new method for municipal solid waste incinerator (MSWI) fly ash inertization, based on colloidal silica.

    Science.gov (United States)

    Bontempi, E; Zacco, A; Borgese, L; Gianoncelli, A; Ardesi, R; Depero, L E

    2010-11-01

    Municipal solid waste incineration (MSWI) is a straightforward way to manage waste, however the disposal of process byproducts, mainly bottom and fly ash, is still a problem, because of their hazardous contents. Fly ash is a byproduct of many other processes that involve combustion to produce energy. In this paper we present and discuss a new method for MSWI fly ash inertization, mainly based on the use of colloidal silica as a stabilization agent for metals. In the patented procedure, fly ash of different provenance can be used to produce an inert and non-hazardous material, that can be reused. In fact to make the recovery process more efficient, landfilling should be totally avoided. For this reason, to enhance the possibility of reuse, a washing process, for salts recovery, is proposed as a final step of the inertization procedure. The obtained inert material is called COSMOS (COlloidal Silica Medium to Obtain Safe inert), and it is composed of calcium carbonate, calcium sulfate, silicon oxide and a wide quantity of non-soluble amorphous compounds. COSMOS does not contain any corrosive salts. This makes it extremely interesting for cement industry applications with several other advantages, and environmental benefits. The new proposed inertization procedure appears very promising, because it allows MSWI fly ash to be considered a valuable resource. Thanks to the obtained results, a demonstration project, in the frame of LIFE+, has been funded by the European Commission (LIFE+ 2008 project ENV/IT/000434, ).

  16. NERI FINAL TECHNICAL REPORT, DE-FC07-O5ID14647, OPTIMIZATION OF OXIDE COMPOUNDS FOR ADVANCED INERT MATRIX MATERIALS

    Energy Technology Data Exchange (ETDEWEB)

    PI: JUAN C. NINO, ASSOCIATE PROFESSOR

    2009-01-11

    In order to reduce the current excesses of plutonium (both weapon grade and reactor grade) and other transuranium elements, a concept of inert matrix fuel (IMF) has been proposed for an uranium free transmutation of fissile actinides which excludes continuous uranium-plutonium conversion in thermal reactors and advanced systems. Magnesium oxide (MgO) is a promising candidate for inert matrix (IM) materials due to its high melting point (2827 C), high thermal conductivity (13 W/K {center_dot} m at 1000 C), good neutronic properties, and irradiation stability However, MgO reacts with water and hydrates easily, which prevents it from being used in light water reactors (LWRs) as an IM. To improve the hydration resistance of MgO-based inert matrix materials, Medvedev and coworkers have recently investigated the introduction of a secondary phase that acts as a hydration barrier. An MgO-ZrO{sub 2} composite was specifically studied and the results showed that the composite exhibited improved hydration resistance than pure MgO. However, ZrO{sub 2} is insoluble in most acids except HF, which is undesirable for fuel reprocessing. Moreover, the thermal conductivity of ZrO{sub 2} is low and typically less than 3 W {center_dot} m{sup -1} {center_dot} K{sup -1} at 1000 C. In search for an alternative composite strategy, Nd{sub 2}Zr{sub 2}O{sub 7}, an oxide compound with pyrochlore structure, has been proposed recently as a corrosion resistant phase, and MgO-Nd{sub 2}Zr{sub 2}O{sub 7} composites have been investigated as potential IM materials. An adequate thermal conductivity of 6 W {center_dot} m{sup -} 1 {center_dot} K{sup -1} at 1000 C for the MgO-Nd{sub 2}Zr{sub 2}O{sub 7} composite with 90 vol% MgO was recently calculated and reported. Other simulations proposed that the MgO-pyrochlore composites could exhibit higher radiation stability than previously reported. Final optimization of the composite microstructure was performed on the 70 vol% MgO-Nd{sub 2}Zr{sub 2}O{sub 7

  17. NERI FINAL TECHNICAL REPORT, DE-FC07-O5ID14647. OPTIMIZATION OF OXIDE COMPOUNDS FOR ADVANCED INERT MATRIX MATERIALS

    International Nuclear Information System (INIS)

    Nino, Juan C.

    2009-01-01

    In order to reduce the current excesses of plutonium (both weapon grade and reactor grade) and other transuranium elements, a concept of inert matrix fuel (IMF) has been proposed for an uranium free transmutation of fissile actinides which excludes continuous uranium-plutonium conversion in thermal reactors and advanced systems. Magnesium oxide (MgO) is a promising candidate for inert matrix (IM) materials due to its high melting point (2827 C), high thermal conductivity (13 W/K · m at 1000 C), good neutronic properties, and irradiation stability However, MgO reacts with water and hydrates easily, which prevents it from being used in light water reactors (LWRs) as an IM. To improve the hydration resistance of MgO-based inert matrix materials, Medvedev and coworkers have recently investigated the introduction of a secondary phase that acts as a hydration barrier. An MgO-ZrO 2 composite was specifically studied and the results showed that the composite exhibited improved hydration resistance than pure MgO. However, ZrO 2 is insoluble in most acids except HF, which is undesirable for fuel reprocessing. Moreover, the thermal conductivity of ZrO 2 is low and typically less than 3 W · m -1 · K -1 at 1000 C. In search for an alternative composite strategy, Nd 2 Zr 2 O 7 , an oxide compound with pyrochlore structure, has been proposed recently as a corrosion resistant phase, and MgO-Nd 2 Zr 2 O 7 composites have been investigated as potential IM materials. An adequate thermal conductivity of 6 W · m - 1 · K -1 at 1000 C for the MgO-Nd 2 Zr 2 O 7 composite with 90 vol% MgO was recently calculated and reported. Other simulations proposed that the MgO-pyrochlore composites could exhibit higher radiation stability than previously reported. Final optimization of the composite microstructure was performed on the 70 vol% MgO-Nd 2 Zr 2 O 7 composite that burnup calculations had shown to have the closest profile to that of MOX fuel. Theoretical calculations also indicated that

  18. The effect of mixing methods and polymer infiltration and pyrolysis (PIP) cycles on the densification of silicon carbide inert matrix fuel through a polymer precursor route

    International Nuclear Information System (INIS)

    Shih Chunghao; Tulenko, J.S.; Baney, R.H.

    2011-01-01

    Highlights: ► A pre-ceramic polymer precursor route was utilized to fabricate SiC based inert matrix fuel (IMF). ► The effect of mixing and polymer infiltration and pyrolysis (PIP) cycles on the fabrication of the SiC IMF was investigated. ► A theoretical density of ∼86% has been achieved after one PIP cycle. ► Pore size distributions before and after PIP cycles have been determined. ► SEM images showed a “springback” effect for 600 MPa pressed pellets. - Abstract: The effect of mixing methods on the fabrication of silicon carbide (SiC) inert matrix fuel through a polymer precursor route was investigated in order to break up the agglomerates of the SiC particles observed in earlier studies. It was found that a high energy shaker mill could effectively break up the agglomerates and thereby achieve a higher pellet density. Moreover, it was found that the pellet density depended less on the pressing pressure, when the particles are well mixed. SEM images showed cracks caused by the springback effect on pellets with a high cold pressing pressure of 600 MPa, but no signs of springback effect were observed for the 200 MPa pressed pellets. The polymer infiltration and pyrolysis (PIP) cycles were used to further increase the pellet density and close the open pores. The first PIP cycle was found to increase the theoretical density of the pellets from 81.2% to 86.0% and close ∼50% of the open pores. The pore size distribution showed that most of the remaining open pores had diameters smaller than 10 nm. The successive second PIP cycle is not as effective on either the density or the pore size distribution because the small pores present before the second PIP cycle made the infiltration process difficult.

  19. Neutronic analysis of U-free inert matrix and thoria fuels for plutonium disposition in pressurised water reactors

    Science.gov (United States)

    Lombardi, C.; Mazzola, A.; Padovani, E.; Ricotti, M. E.

    1999-08-01

    Inserting reactor-grade (RG) or weapons-grade (WG) plutonium in uranium-free matrices and burning it in light water reactors (LWRs) is an option gaining a wider consensus in the nuclear community. The main results of our neutronic studies performed in the last few years on this subject are reported. Our attention was mainly concentrated on two kinds of matrices: inert matrix in the form of calcia-stabilised zirconia, and thoria. Both materials are likely to exhibit excellent behaviour under irradiation (already demonstrated for thoria fuels) and high chemical stability. Direct disposal of spent fuel should be made feasible and attractive. A preliminary neutronic analysis was performed on these U-free fuels, imposing the constraint of maintaining the same assembly design and cycle length of a standard enriched-uranium fuel. In particular inert matrix fuel (IMF) showed a high plutonium burning capability, but associated with unacceptable feedback coefficients. Therefore, a whole IMF core results unfeasible, and only a partial core loading is possible. The solution then studied consists in replacing ≈21% of the pins of a standard enriched-U subassembly with IMF pins. Detailed assembly and core calculations were performed. A crucial aspect is the choice of a suitable burnable poison, which has to dampen the power peaks in the different fuel pin types without life penalisation. Among the considered poisons, a thin boron coating on the IMF pellets resulted the only effective one. Preliminary IMF pin cell calculations and the detailed ones gave similar results in terms of burnt plutonium fractions: 90% of fissile and 73% of total plutonium is burnt when RG plutonium is used. The main drawbacks of this fuel are the limited core loading capability and the lack of in-pile technological validation. In the case of Pu-Th fuels, pin cell calculations showed that increasing the plutonia content, decreasing the thoria content, and decreasing the pellet diameter are all possible

  20. Effect of Burnable Absorbers on Inert Matrix Fuel Performance and Transuranic Burnup in a Low Power Density Light-Water Reactor

    Directory of Open Access Journals (Sweden)

    Geoff Recktenwald

    2013-04-01

    Full Text Available Zirconium dioxide has received particular attention as a fuel matrix because of its ability to form a solid solution with transuranic elements, natural radiation stability and desirable mechanical properties. However, zirconium dioxide has a lower coefficient of thermal conductivity than uranium dioxide and this presents an obstacle to the deployment of these fuels in commercial reactors. Here we show that axial doping of a zirconium dioxide based fuel with erbium reduces power peaking and fuel temperature. Full core simulations of a modified AP1000 core were done using MCNPX 2.7.0. The inert matrix fuel contained 15 w/o transuranics at its beginning of life and constituted 28% of the assemblies in the core. Axial doping reduced power peaking at startup by more than ~23% in the axial direction and reduced the peak to average power within the core from 1.80 to 1.44. The core was able to remain critical between refueling while running at a simulated 2000 MWth on an 18 month refueling cycle. The results show that the reactor would maintain negative core average reactivity and void coefficients during operation. This type of fuel cycle would reduce the overall production of transuranics in a pressurized water reactor by 86%.

  1. Demand-Based Optimal Design of Storage Tank with Inerter System

    Directory of Open Access Journals (Sweden)

    Shiming Zhang

    2017-01-01

    Full Text Available A parameter optimal design method for a tank with an inerter system is proposed in this study based on the requirements of tank vibration control to improve the effectiveness and efficiency of vibration control. Moreover, a response indicator and a cost control indicator are selected based on the control targets for liquid storage tanks for simultaneously minimizing the dynamic response and controlling costs. These indicators are reformulated through a random vibration analysis under virtual excitation. The problem is then transformed from a multiobjective optimization problem to a single-objective nonlinear problem using the ε-constraint method, which is consistent with the demand-based method. White noise excitation can be used to design the tank with the inerter system under seismic excitation to simplify the calculation. Subsequently, a MATLAB-based calculation program is compiled, and several optimization cases are examined under different excitation conditions. The effectiveness of the demand-based method is proven through a time history analysis. The results show that specific vibration control requirements can be met at the lowest cost with a simultaneous reduction in base shears and overturning base moments.

  2. Correntropy Based Matrix Completion

    Directory of Open Access Journals (Sweden)

    Yuning Yang

    2018-03-01

    Full Text Available This paper studies the matrix completion problems when the entries are contaminated by non-Gaussian noise or outliers. The proposed approach employs a nonconvex loss function induced by the maximum correntropy criterion. With the help of this loss function, we develop a rank constrained, as well as a nuclear norm regularized model, which is resistant to non-Gaussian noise and outliers. However, its non-convexity also leads to certain difficulties. To tackle this problem, we use the simple iterative soft and hard thresholding strategies. We show that when extending to the general affine rank minimization problems, under proper conditions, certain recoverability results can be obtained for the proposed algorithms. Numerical experiments indicate the improved performance of our proposed approach.

  3. Heavy ion induced damage in MgAl sub 2 O sub 4 , an inert matrix candidate for the transmutation of minor actinides

    CERN Document Server

    Wiss, T

    1999-01-01

    Magnesium aluminum spinel (MgAl sub 2 O sub 4) is a material selected as a possible matrix for transmutation of minor actinides by neutron capture or fission in nuclear reactors. To study the radiation stability of this inert matrix, especially against fission product impact, irradiations with heavy energetic ions or clusters have been performed. The high electronic energy losses of the heavy ions in this material led to the formation of visible tracks as evidenced by transmission electron microscopy for 30 MeV C sub 6 sub 0 -Buckminster fullerenes and for ions of energy close to or higher than fission energy ( sup 2 sup 0 sup 9 Bi with 120 MeV and 2.38 GeV energy). The irradiations at high energies showed a pronounced degradation of the spinel. Additionally, MgAl sub 2 O sub 4 exhibited a large swelling for irradiation at high fluences with fission products of fission energy (here I-ions of 72 MeV) and at temperatures <= 500 deg. C. These observations are discussed from the technological point of view in ...

  4. Preparation of tunable-sized iron nanoparticles based on magnetic manipulation in inert gas condensation (IGC)

    NARCIS (Netherlands)

    Xing, Lijuan; ten Brink, Gert H.; Kooi, Bart J.; Palasantzas, George

    2017-01-01

    Iron nanoparticles (NPs) prepared by inert gas condensation were studied using high resolution transmission electron microscopy and Wulff construction shape analysis. The NP size and shape show strong dependence on the magnetic field above the target surface. The effect of the magnetic field could

  5. Parameter optimization of an inerter-based isolator for passive vibration control of Michelangelo's Rondanini Pietà

    Science.gov (United States)

    Siami, A.; Karimi, H. R.; Cigada, A.; Zappa, E.; Sabbioni, E.

    2018-01-01

    Preserving cultural heritage against earthquake and ambient vibrations can be an attractive topic in the field of vibration control. This paper proposes a passive vibration isolator methodology based on inerters for improving the performance of the isolation system of the famous statue of Michelangelo Buonarroti Pietà Rondanini. More specifically, a five-degree-of-freedom (5DOF) model of the statue and the anti-seismic and anti-vibration base is presented and experimentally validated. The parameters of this model are tuned according to the experimental tests performed on the assembly of the isolator and the structure. Then, the developed model is used to investigate the impact of actuation devices such as tuned mass-damper (TMD) and tuned mass-damper-inerter (TMDI) in vibration reduction of the structure. The effect of implementation of TMDI on the 5DOF model is shown based on physical limitations of the system parameters. Simulation results are provided to illustrate effectiveness of the passive element of TMDI in reduction of the vibration transmitted to the statue in vertical direction. Moreover, the optimal design parameters of the passive system such as frequency and damping coefficient will be calculated using two different performance indexes. The obtained optimal parameters have been evaluated by using two different optimization algorithms: the sequential quadratic programming method and the Firefly algorithm. The results prove significant reduction in the transmitted vibration to the structure in the presence of the proposed tuned TMDI, without imposing a large amount of mass or modification to the structure of the isolator.

  6. Inerting ballast tanks

    Energy Technology Data Exchange (ETDEWEB)

    Baes, Gabriel L.; Bronneberg, Jos [SBM Offshore, AA Schiedam (Netherlands); Barros, Maria A.S.D. de [Universidade Estadual de Maringa (UEM), PR (Brazil)

    2012-07-01

    This report expands upon the work conducted by SBM Offshore to develop a tank preservation treatment, which is intended to achieve a service life of 30 years. This work focuses on the corrosion problems, in the ballast tanks, based on new built hulls, both for the Gas Exploration Market, the FLNG - Floating Liquefied Natural Gas, and for the Oil Exploration market - FPSO's - Floating Production Storage and offloading Units. Herein, the corrosion rate input comes from the various references related to the process of nitrogen injection, which is expected to extend the vessel's time life. The essential elements of this solution comprise the deoxygenation process, corrosion models, coating effects, tests from laboratory, shipboard tests, corrosion institutes and regulations applicable to the operation. The best corrosion protection system for ballast tanks area combines a coating system and an inert gas system. The condition of the tanks will be dependent upon the level of protection applied to the steel structure, including, but not limited to coating, cathodic protection, etc. There is a need for products which extend the life time. It is not sufficient, only have good theoretical base for the corrosion and an excellent treatment system. In addition, the design of the ships structure must also eliminate the presence of local stress concentrations which can result in fatigue cracking and rupture of the protective coating barrier starting the corrosion. As a direct result of this, more problems in corrosion can be mitigated, vessels can have a better corrosion performance with less maintenance and repairs to coating systems in ballast tanks. Furthermore ships will be positively impacted operationally due to less frequent dry docking. There is a huge potential in the application of inert gas to combat the corrosion rate inside the ballast tanks, one of the most corrosive environments on earth. This application can have a direct impact on vessel structure

  7. Electrolysis of metal oxides in MgCl2 based molten salts with an inert graphite anode.

    Science.gov (United States)

    Yuan, Yating; Li, Wei; Chen, Hualin; Wang, Zhiyong; Jin, Xianbo; Chen, George Z

    2016-08-15

    Electrolysis of solid metal oxides has been demonstrated in MgCl2-NaCl-KCl melt at 700 °C taking the electrolysis of Ta2O5 as an example. Both the cathodic and anodic processes have been investigated using cyclic voltammetry, and potentiostatic and constant voltage electrolysis, with the cathodic products analysed by XRD and SEM and the anodic products by GC. Fast electrolysis of Ta2O5 against a graphite anode has been realized at a cell voltage of 2 V, or a total overpotential of about 400 mV. The energy consumption was about 1 kW h kgTa(-1) with a nearly 100% Ta recovery. The cathodic product was nanometer Ta powder with sizes of about 50 nm. The main anodic product was Cl2 gas, together with about 1 mol% O2 gas and trace amounts of CO. The graphite anode was found to be an excellent inert anode. These results promise an environmentally-friendly and energy efficient method for metal extraction by electrolysis of metal oxides in MgCl2 based molten salts.

  8. Development of an accumulation-based system for cost-effective chamber measurements of inert trace gas fluxes

    DEFF Research Database (Denmark)

    Ambus, Per; Skiba, U.; Drewer, J.

    2010-01-01

    sampling with low-frequency chemical analysis. The System for Inert Gas Monitoring by Accumulation (SIGMA) is suited particularly for stand-alone observations in remote locations. The SIGMA is connected to an automated chamber with headspace sampling several times per day. Air samples are aggregated...

  9. Deghosting based on the transmission matrix method

    Science.gov (United States)

    Wang, Benfeng; Wu, Ru-Shan; Chen, Xiaohong

    2017-12-01

    As the developments of seismic exploration and subsequent seismic exploitation advance, marine acquisition systems with towed streamers become an important seismic data acquisition method. But the existing air-water reflective interface can generate surface related multiples, including ghosts, which can affect the accuracy and performance of the following seismic data processing algorithms. Thus, we derive a deghosting method from a new perspective, i.e. using the transmission matrix (T-matrix) method instead of inverse scattering series. The T-matrix-based deghosting algorithm includes all scattering effects and is convergent absolutely. Initially, the effectiveness of the proposed method is demonstrated using synthetic data obtained from a designed layered model, and its noise-resistant property is also illustrated using noisy synthetic data contaminated by random noise. Numerical examples on complicated data from the open SMAART Pluto model and field marine data further demonstrate the validity and flexibility of the proposed method. After deghosting, low frequency components are recovered reasonably and the fake high frequency components are attenuated, and the recovered low frequency components will be useful for the subsequent full waveform inversion. The proposed deghosting method is currently suitable for two-dimensional towed streamer cases with accurate constant depth information and its extension into variable-depth streamers in three-dimensional cases will be studied in the future.

  10. Alternative inerting agents

    CSIR Research Space (South Africa)

    Du Plessis, JJL

    1997-08-01

    Full Text Available This project was launched to determine whether other inert material might be suitable to replace or complement the stone dust. The materials investigated were two different types of fly ash, two types of stone dust, water and calcium sulphate...

  11. Inert Anode Report

    Energy Technology Data Exchange (ETDEWEB)

    none,

    1999-07-01

    This ASME report provides a broad assessment of open literature and patents that exist in the area of inert anodes and their related cathode systems and cell designs, technologies that are relevant for the advanced smelting of aluminum. The report also discusses the opportunities, barriers, and issues associated with these technologies from a technical, environmental, and economic viewpoint.

  12. QUEUEING DISCIPLINES BASED ON PRIORITY MATRIX

    Directory of Open Access Journals (Sweden)

    Taufik I. Aliev

    2014-11-01

    Full Text Available The paper deals with queueing disciplines for demands of general type in queueing systems with multivendor load. A priority matrix is proposed to be used for the purpose of mathematical description of such disciplines, which represents the priority type (preemptive priority, not preemptive priority or no priority between any two demands classes. Having an intuitive and simple way of priority assignment, such description gives mathematical dependencies of system operation characteristics on its parameters. Requirements for priority matrix construction are formulated and the notion of canonical priority matrix is given. It is shown that not every matrix, constructed in accordance with such requirements, is correct. The notion of incorrect priority matrix is illustrated by an example, and it is shown that such matrixes do not ensure any unambiguousness and determinacy in design of algorithm, which realizes corresponding queueing discipline. Rules governing construction of correct matrixes are given for canonical priority matrixes. Residence time for demands of different classes in system, which is the sum of waiting time and service time, is considered as one of the most important characteristics. By introducing extra event method Laplace transforms for these characteristics are obtained, and mathematical dependencies are derived on their basis for calculation of two first moments for corresponding characteristics of demands queueing

  13. Inert and stable erbium(III)-cored complexes based on metalloporphyrins bearing aryl-ether dendron for optical amplification: synthesis and emission enhancement

    International Nuclear Information System (INIS)

    Oh, Jae Buem; Kim, Yong Hee; Nah, Min Kook; Kim, Hwan Kyu

    2005-01-01

    We have developed novel inert and stable erbium (Er)(III)-cored complexes based on metalloporphyrins for optical amplification. The functionalized metalloporphyrin ligands have been designed and synthesized to provide enough coordination sites for the formation of inert and stable 9-coordinated Er(III)-cored complexes. Er 3+ ions were encapsulated by the metalloporphyrin ligands, such as Zn(II)- and Pt(II)-porphyrins. The near-infrared (IR) emission intensity of Er 3+ ion is much stronger in the Er(III)-cored complex based on Pt(II)-porphyrin than Er(III)-cored complex based on Zn(II)-porphyrin. Furthermore, we have incorporated a G2-aryl-ether functionalized dendron into the Er(III)-cored complex, yielding an Er(III)-cored dendrimer complex bearing the Pt(II)-porphyrin. The Er(III)-cored dendrimer complex shows the stronger near-IR emission intensity than the corresponding complex based on Pt(II)-porphyrin by seven times in solid state. The lifetimes of the emission band of Pt(II)-porphyrin ligands in the visible region were found to be 30 and 40 μs for the Er(III)-cored complex and the Er(III)-cored dendrimer complex based on Pt(II)-porphyrin in deoxygenated THF solution samples, respectively. Also, in both cases, the sensitized luminescence intensity is increased in deoxygenated solution. Therefore, it indicates that the energy transfer from the metalloporphyrins to Er 3+ ions takes places through the triplet state. In this paper, the synthesis and photophysical properties of novel Er(III)-cored complexes based on metalloporphyrins and Er(III)-cored dendrimer complex based on metalloporphyrin will be discussed

  14. Intelligent data analysis based on rough correlativity matrix

    Science.gov (United States)

    Geng, Zhiqiang; Zhu, Qunxiong

    2003-09-01

    This paper proposes a new data analysis method based on rough sets by rough correlativity matrix. In rough set theory, a table called information system or database is used as a special kind of formal language to represent knowledge, a rough correlativity matrix (RCM) can be seen as an internal representation of equivalence relations. Furthermore, this paper provides a new heuristic attributes reduction algorithm based on matrix computing, such as using matrix correlative implements to replace the relations computing between sets. Finally the paper adopts information transition matrix (ITM) of information theory to represent the certainty or uncertainty decision rules based on probability theory, namely, the information matrix composed of certainty factors gives the degree of belief of decision rules, on the contrary the "invert" ITM composed of coverage factor gives the interpretation of decision rules. The result of instance analysis is shown that it is an efficient and feasible method to deal with decision information table.

  15. OD Matrix Acquisition Based on Mobile Phone Positioning Data

    Directory of Open Access Journals (Sweden)

    Xiaoqing ZUO

    2014-06-01

    Full Text Available Dynamic OD matrix is basic data of traffic travel guidance, traffic control, traffic management and traffic planning, and reflects the basic needs of travelers on the traffic network. With the rising popularity of positioning technology and the communication technology and the generation of huge mobile phone users, the mining and use of mobile phone positioning data, can get more traffic intersections and import and export data. These data will be integrated into obtaining the regional OD matrix, which is bound to bring convenience. In this article, mobile phone positioning data used in the data acquisition of intelligent transportation system, research a kind of regional dynamic OD matrix acquisition method based on the mobile phone positioning data. The method based on purpose of transportation, using time series similarity classification algorithm based on piecewise linear representation of the corner point (CP-PLR, mapping each base station cell to traffic zone of different traffic characteristics, and through a series of mapping optimization of base station cell to traffic zone to realize city traffic zone division based on mobile phone traffic data, on the basis, adjacency matrix chosen as the physical data structure of OD matrix storage, the principle of obtaining regional dynamic OD matrix based on the mobile phone positioning data are expounded, and the algorithm of obtaining regional dynamic OD matrix based on mobile phone positioning data are designed and verified.

  16. Origins of inert Higgs doublets

    Directory of Open Access Journals (Sweden)

    Thomas W. Kephart

    2016-05-01

    Full Text Available We consider beyond the standard model embedding of inert Higgs doublet fields. We argue that inert Higgs doublets can arise naturally in grand unified theories where the necessary associated Z2 symmetry can occur automatically. Several examples are discussed.

  17. Equation of state for inert gas solids

    Indian Academy of Sciences (India)

    Srimath

    Keywords. Equation of state; inert gas solids; thermal expansion; bulk modulus. PACS Nos 64.10.+h; 64.30.+t. 1. Introduction. Much of the physical world around us and a large part of modern technology are based on solid materials. So it is interesting to study the behavior and thermophys- ical properties of different solids.

  18. Geometric deviation modeling by kinematic matrix based on Lagrangian coordinate

    Science.gov (United States)

    Liu, Weidong; Hu, Yueming; Liu, Yu; Dai, Wanyi

    2015-09-01

    Typical representation of dimension and geometric accuracy is limited to the self-representation of dimension and geometric deviation based on geometry variation thinking, yet the interactivity affection of geometric variation and gesture variation of multi-rigid body is not included. In this paper, a kinematic matrix model based on Lagrangian coordinate is introduced, with the purpose of unified model for geometric variation and gesture variation and their interactive and integrated analysis. Kinematic model with joint, local base and movable base is built. The ideal feature of functional geometry is treated as the base body; the fitting feature of functional geometry is treated as the adjacent movable body; the local base of the kinematic model is fixed onto the ideal geometry, and the movable base of the kinematic model is fixed onto the fitting geometry. Furthermore, the geometric deviation is treated as relative location or rotation variation between the movable base and the local base, and it's expressed by the Lagrangian coordinate. Moreover, kinematic matrix based on Lagrangian coordinate for different types of geometry tolerance zones is constructed, and total freedom for each kinematic model is discussed. Finally, the Lagrangian coordinate library, kinematic matrix library for geometric deviation modeling is illustrated, and an example of block and piston fits is introduced. Dimension and geometric tolerances of the shaft and hole fitting feature are constructed by kinematic matrix and Lagrangian coordinate, and the results indicate that the proposed kinematic matrix is capable and robust in dimension and geometric tolerances modeling.

  19. Matrix-based introduction to multivariate data analysis

    CERN Document Server

    Adachi, Kohei

    2016-01-01

    This book enables readers who may not be familiar with matrices to understand a variety of multivariate analysis procedures in matrix forms. Another feature of the book is that it emphasizes what model underlies a procedure and what objective function is optimized for fitting the model to data. The author believes that the matrix-based learning of such models and objective functions is the fastest way to comprehend multivariate data analysis. The text is arranged so that readers can intuitively capture the purposes for which multivariate analysis procedures are utilized: plain explanations of the purposes with numerical examples precede mathematical descriptions in almost every chapter. This volume is appropriate for undergraduate students who already have studied introductory statistics. Graduate students and researchers who are not familiar with matrix-intensive formulations of multivariate data analysis will also find the book useful, as it is based on modern matrix formulations with a special emphasis on ...

  20. Link prediction based on non-negative matrix factorization

    Science.gov (United States)

    Chen, Bolun; Li, Fenfen; Hu, Ronglin; Chen, Ling

    2017-01-01

    With the rapid expansion of internet, the complex networks has become high-dimensional, sparse and redundant. Besides, the problem of link prediction in such networks has also obatined increasingly attention from different types of domains like information science, anthropology, sociology and computer sciences. It makes requirements for effective link prediction techniques to extract the most essential and relevant information for online users in internet. Therefore, this paper attempts to put forward a link prediction algorithm based on non-negative matrix factorization. In the algorithm, we reconstruct the correlation between different types of matrix through the projection of high-dimensional vector space to a low-dimensional one, and then use the similarity between the column vectors of the weight matrix as the scoring matrix. The experiment results demonstrate that the algorithm not only reduces data storage space but also effectively makes the improvements of the prediction performance during the process of sustaining a low time complexity. PMID:28854195

  1. Link prediction based on non-negative matrix factorization.

    Science.gov (United States)

    Chen, Bolun; Li, Fenfen; Chen, Senbo; Hu, Ronglin; Chen, Ling

    2017-01-01

    With the rapid expansion of internet, the complex networks has become high-dimensional, sparse and redundant. Besides, the problem of link prediction in such networks has also obatined increasingly attention from different types of domains like information science, anthropology, sociology and computer sciences. It makes requirements for effective link prediction techniques to extract the most essential and relevant information for online users in internet. Therefore, this paper attempts to put forward a link prediction algorithm based on non-negative matrix factorization. In the algorithm, we reconstruct the correlation between different types of matrix through the projection of high-dimensional vector space to a low-dimensional one, and then use the similarity between the column vectors of the weight matrix as the scoring matrix. The experiment results demonstrate that the algorithm not only reduces data storage space but also effectively makes the improvements of the prediction performance during the process of sustaining a low time complexity.

  2. Model-based OPC using the MEEF matrix

    Science.gov (United States)

    Cobb, Nicolas B.; Granik, Yuri

    2002-12-01

    This paper covers the topic of matrix-OPC. In matrix-OPC, we perform OPC edge movements, considering the cross-MEEF of all edges which affect the edge placement error (EPE) at each simulation site. This contrasts with standard model-based OPC methods. In the standard methods a simulation site is placed on each edge fragment. The EPE is monitored by simulation along all sites. The EPE is assumed to be controllable for each site by moving the position of its edge fragment. In matrix OPC, not just one fragment, but all fragments which influence the EPE are used to control the EPE for a given site. Matrix OPC has application to the following areas: (1) OPC on PSM where non-adjacent edges can have larger impact than adjacent edges, (2) dipole and other complex illumination schemes, and (3) when the assumption that the self-MEEF terms are dominant starts to break down or when MEEF becomes negative.

  3. Construction of Kostka matrix at the level of bases

    International Nuclear Information System (INIS)

    Jakubczyk, P; Lulek, T; Jakubczyk, D; Lulek, B

    2008-01-01

    We develop a method of construction of transformation matrix between two bases of the model of Heisenberg magnet. The first one is a natural basis of magnetic configurations while the second is adjusted to the irreducible basis of the duality of Weyl. Proposed method allows us to calculate each matrix element separately, so it does not depend on the dimension of the system. Calculation of a matrix elements is given by ladder construction of consecutive letters of magnetic configurations along the well known Robinson-Schensted algorithm. In this way we obtain a graph with vertices given by Gelfand patterns and edges labelled by insertion algorithm. This graph allows us to read off all Clebsch-Gordan coefficients for a unitary group U(n) and then to calculate the matrix element

  4. Trigonometric bases for matrix weighted Lp-spaces

    DEFF Research Database (Denmark)

    Nielsen, Morten

    2010-01-01

    We give a complete characterization of 2π-periodic matrix weights W for which the vector-valued trigonometric system forms a Schauder basis for the matrix weighted space Lp(T;W). Then trigonometric quasi-greedy bases for Lp(T;W) are considered. Quasi-greedy bases are systems for which the simple...... thresholding approximation algorithm converges in norm. It is proved that such a trigonometric basis can be quasi-greedy only for p=2, and whenever the system forms a quasi-greedy basis, the basis must actually be a Riesz basis....

  5. Matrix-based image reconstruction methods for tomography

    International Nuclear Information System (INIS)

    Llacer, J.; Meng, J.D.

    1984-10-01

    Matrix methods of image reconstruction have not been used, in general, because of the large size of practical matrices, ill condition upon inversion and the success of Fourier-based techniques. An exception is the work that has been done at the Lawrence Berkeley Laboratory for imaging with accelerated radioactive ions. An extension of that work into more general imaging problems shows that, with a correct formulation of the problem, positron tomography with ring geometries results in well behaved matrices which can be used for image reconstruction with no distortion of the point response in the field of view and flexibility in the design of the instrument. Maximum Likelihood Estimator methods of reconstruction, which use the system matrices tailored to specific instruments and do not need matrix inversion, are shown to result in good preliminary images. A parallel processing computer structure based on multiple inexpensive microprocessors is proposed as a system to implement the matrix-MLE methods. 14 references, 7 figures

  6. Fabrication of Completely Polymer-Based Solar Cells with p- and n-Type Semiconducting Block Copolymers with Electrically Inert Polystyrene.

    Science.gov (United States)

    Tomita, Eri; Kanehashi, Shinji; Ogino, Kenji

    2018-02-27

    It is widely recognized that fullerene derivatives show several advantages as n-type materials in photovoltaic applications. However, conventional [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) exhibits weak absorption in the visible region, and poor morphological stability, due to the facile aggregation. For further improvement of the device performance and durability, utilization of n-type polymeric materials instead of PCBM is considered to be a good way to solve the problems. In this study, we fabricated completely polymer-based solar cells utilizing p- and n-type block copolymers consisting of poly(3-hexylthiophene) (P3HT) and poly{[ N , N' -bis(2-octyldodecyl)naphthalene-1,4,5,8- bis (dicarboximide)-2,6-diyl]- alt -5,5'-(2,2'-bithiophene)} [P(NDI2OD-T2)], respectively, containing common polystyrene (PSt) inert blocks, which decreased the size of phase separated structures. Electron mobility in synthesized P(NDI2OD-T2)- b -PSt film enhanced by a factor of 8 compared with homopolymer. The root mean square roughness of the blend film of two block copolymers (12.2 nm) was decreased, compared with that of the simple homopolymers blend (18.8 nm). From the current density-voltage characteristics, it was confirmed that the introduction of PSt into both P3HT and P(NDI2OD-T2) improves short-circuit current density (1.16 to 1.73 mA cm -2 ) and power-conversion efficiency (0.24% to 0.32%). Better performance is probably due to the uniformity of the phase separation, and the enhancement of charge mobility.

  7. Fabrication of Completely Polymer-Based Solar Cells with p- and n-Type Semiconducting Block Copolymers with Electrically Inert Polystyrene

    Directory of Open Access Journals (Sweden)

    Eri Tomita

    2018-02-01

    Full Text Available It is widely recognized that fullerene derivatives show several advantages as n-type materials in photovoltaic applications. However, conventional [6,6]-phenyl-C61-butyric acid methyl ester (PCBM exhibits weak absorption in the visible region, and poor morphological stability, due to the facile aggregation. For further improvement of the device performance and durability, utilization of n-type polymeric materials instead of PCBM is considered to be a good way to solve the problems. In this study, we fabricated completely polymer-based solar cells utilizing p- and n-type block copolymers consisting of poly(3-hexylthiophene (P3HT and poly{[N,N′-bis(2-octyldodecylnaphthalene-1,4,5,8-bis(dicarboximide-2,6-diyl]-alt-5,5′-(2,2′-bithiophene} [P(NDI2OD-T2], respectively, containing common polystyrene (PSt inert blocks, which decreased the size of phase separated structures. Electron mobility in synthesized P(NDI2OD-T2-b-PSt film enhanced by a factor of 8 compared with homopolymer. The root mean square roughness of the blend film of two block copolymers (12.2 nm was decreased, compared with that of the simple homopolymers blend (18.8 nm. From the current density-voltage characteristics, it was confirmed that the introduction of PSt into both P3HT and P(NDI2OD-T2 improves short-circuit current density (1.16 to 1.73 mA cm−2 and power-conversion efficiency (0.24% to 0.32%. Better performance is probably due to the uniformity of the phase separation, and the enhancement of charge mobility.

  8. Fabrication of Completely Polymer-Based Solar Cells with p- and n-Type Semiconducting Block Copolymers with Electrically Inert Polystyrene

    Science.gov (United States)

    Tomita, Eri; Kanehashi, Shinji; Ogino, Kenji

    2018-01-01

    It is widely recognized that fullerene derivatives show several advantages as n-type materials in photovoltaic applications. However, conventional [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) exhibits weak absorption in the visible region, and poor morphological stability, due to the facile aggregation. For further improvement of the device performance and durability, utilization of n-type polymeric materials instead of PCBM is considered to be a good way to solve the problems. In this study, we fabricated completely polymer-based solar cells utilizing p- and n-type block copolymers consisting of poly(3-hexylthiophene) (P3HT) and poly{[N,N′-bis(2-octyldodecyl)naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-bithiophene)} [P(NDI2OD-T2)], respectively, containing common polystyrene (PSt) inert blocks, which decreased the size of phase separated structures. Electron mobility in synthesized P(NDI2OD-T2)-b-PSt film enhanced by a factor of 8 compared with homopolymer. The root mean square roughness of the blend film of two block copolymers (12.2 nm) was decreased, compared with that of the simple homopolymers blend (18.8 nm). From the current density-voltage characteristics, it was confirmed that the introduction of PSt into both P3HT and P(NDI2OD-T2) improves short-circuit current density (1.16 to 1.73 mA cm−2) and power-conversion efficiency (0.24% to 0.32%). Better performance is probably due to the uniformity of the phase separation, and the enhancement of charge mobility. PMID:29495464

  9. Development of an evaluation matrix for a community-based ...

    African Journals Online (AJOL)

    ... matrix based on the Concept-Indicator-Method, which served as the organising framework for the evaluation. The focus of the evaluation was on assessing the perceived effectiveness and impact on the stakeholders of the course so as to direct the teaching and learning of health promotion at higher education institutions.

  10. A Spreadsheet-Based, Matrix Formulation Linear Programming Lesson

    DEFF Research Database (Denmark)

    Harrod, Steven

    2009-01-01

    The article focuses on the spreadsheet-based, matrix formulation linear programming lesson. According to the article, it makes a higher level of theoretical mathematics approachable by a wide spectrum of students wherein many may not be decision sciences or quantitative methods majors. Moreover...

  11. Stochastic-Strength-Based Damage Simulation Tool for Ceramic Matrix and Polymer Matrix Composite Structures

    Science.gov (United States)

    Nemeth, Noel N.; Bednarcyk, Brett A.; Pineda, Evan J.; Walton, Owen J.; Arnold, Steven M.

    2016-01-01

    Stochastic-based, discrete-event progressive damage simulations of ceramic-matrix composite and polymer matrix composite material structures have been enabled through the development of a unique multiscale modeling tool. This effort involves coupling three independently developed software programs: (1) the Micromechanics Analysis Code with Generalized Method of Cells (MAC/GMC), (2) the Ceramics Analysis and Reliability Evaluation of Structures Life Prediction Program (CARES/ Life), and (3) the Abaqus finite element analysis (FEA) program. MAC/GMC contributes multiscale modeling capabilities and micromechanics relations to determine stresses and deformations at the microscale of the composite material repeating unit cell (RUC). CARES/Life contributes statistical multiaxial failure criteria that can be applied to the individual brittle-material constituents of the RUC. Abaqus is used at the global scale to model the overall composite structure. An Abaqus user-defined material (UMAT) interface, referred to here as "FEAMAC/CARES," was developed that enables MAC/GMC and CARES/Life to operate seamlessly with the Abaqus FEA code. For each FEAMAC/CARES simulation trial, the stochastic nature of brittle material strength results in random, discrete damage events, which incrementally progress and lead to ultimate structural failure. This report describes the FEAMAC/CARES methodology and discusses examples that illustrate the performance of the tool. A comprehensive example problem, simulating the progressive damage of laminated ceramic matrix composites under various off-axis loading conditions and including a double notched tensile specimen geometry, is described in a separate report.

  12. Carbon Nano tubes Based Mixed Matrix Membrane for Gas Separation

    International Nuclear Information System (INIS)

    Sanip, S.M.; Ismail, A.F.; Goh, P.S.; Norrdin, M.N.A.; Soga, T.; Tanemura, M.; Yasuhiko, H.

    2011-01-01

    Carbon nano tubes based mixed matrix membrane (MMM) was prepared by the solution casting method in which the functionalized multi walled carbon nano tubes (f-MWNTs) were embedded into the polyimide membrane and the resulting membranes were characterized. The effect of nominal MWNTs content between 0.5 and 1.0 wt % on the gas separation properties were looked into. The morphologies of the MMM also indicated that at 0.7 % loading of f- MWNTs, the structures of the MMM showed uniform finger-like structures which have facilitated the fast gas transport through the polymer matrix. It may also be concluded that addition of open ended and shortened MWNTs to the polymer matrix can improve its permeability by increasing diffusivity through the MWNTs smooth cavity. (author)

  13. The Inert and the Noble

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 3. The Inert and the Noble. A G Samuelson. Article-in-a-Box Volume 4 Issue 3 March 1999 pp 3-5 ... Author Affiliations. A G Samuelson1. Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore, India.

  14. Matrix-Vector Based Fast Fourier Transformations on SDR Architectures

    Directory of Open Access Journals (Sweden)

    Y. He

    2008-05-01

    Full Text Available Today Discrete Fourier Transforms (DFTs are applied in various radio standards based on OFDM (Orthogonal Frequency Division Multiplex. It is important to gain a fast computational speed for the DFT, which is usually achieved by using specialized Fast Fourier Transform (FFT engines. However, in face of the Software Defined Radio (SDR development, more general (parallel processor architectures are often desirable, which are not tailored to FFT computations. Therefore, alternative approaches are required to reduce the complexity of the DFT. Starting from a matrix-vector based description of the FFT idea, we will present different factorizations of the DFT matrix, which allow a reduction of the complexity that lies between the original DFT and the minimum FFT complexity. The computational complexities of these factorizations and their suitability for implementation on different processor architectures are investigated.

  15. Hybrid materials based on organic luminophores in inorganic glass matrix

    Science.gov (United States)

    Petrova, O. B.; Avetisov, R. I.; Avetisov, I. Kh.; Mushkalo, O. A.; Khomyakov, A. V.; Cherednichenko, A. G.

    2013-06-01

    Hybrid materials were synthesized based on borate glass matrix and the tris(8-hydroxyquinoline) aluminum (Alq3) organic luminophore, which is used as a green luminophore in OLED devices. The luminescent properties of hybrid materials with 0.02-0.1 wt % of Alq3 in glass were studied. The luminescence peak of the hybrid material is significantly shifted to shorter wavelengths (443 nm versus 518 nm in pure Alq3 powder).

  16. A Spreadsheet-Based, Matrix Formulation Linear Programming Lesson

    DEFF Research Database (Denmark)

    Harrod, Steven

    2009-01-01

    The article focuses on the spreadsheet-based, matrix formulation linear programming lesson. According to the article, it makes a higher level of theoretical mathematics approachable by a wide spectrum of students wherein many may not be decision sciences or quantitative methods majors. Moreover......, it is consistent with the Arganbright Principles because the arrays and functions are clear in their operation and easily manipulated by the user....

  17. Radiochemical and inert gas analyses

    International Nuclear Information System (INIS)

    Andrews, J.N.

    1985-01-01

    The subject is discussed under the headings: introduction (radioelement solution in groundwaters; U and Th; Ra and Rn; atmospheric and radiogenic solution in groundwaters; atmosphere derived gases; radiogenic helium; radiogenic argon; biogenic gases); analytical methods (sampling; U-content and 234 U/ 238 U activity ratio; 222 Ru; 226 Ra; dissolved inert gases; 4 He in core samples); the gamma spectrometric determination of U,Th and K. Results are presented and discussed. (U.K.)

  18. High strain carbon nanotubes based epoxy matrix nanocomposite

    Science.gov (United States)

    Manocha, L. M.; Basak, Arpana; Bhandari, T.; Baishya, T.; Manocha, S.

    2013-06-01

    Multiwalled carbon nanotubes, synthesized by catalytic chemical vapour deposition using xylene as the carbon precursor and ferrocene as the catalyst source, were used as reinforcements for the preparation of carbon nanotubes based epoxy matrix composites. For higher degree of dispersion in the matrix system, oxygen containing groups (C=O, COOH) were attached to the surface of carbon nanotubes by acid treatment followed by rigorous sonication of reinforcement in the matrix system. FTIR confirms the formation of oxygen containing groups on the surface of the carbon nanotubes. Tensile strength and glass transition temperature of the epoxy resin as well as nanocomposite samples have been determined. Carbon nanotubes reinforced composites exhibited ten times higher elongation than as such epoxy mainly due to the strengthening effect of the dispersed nanotubes and the development of moderate interfacial bonding between the resin and the reinforcing agent. A noticeable increase in the glass transition temperature of ˜20°C in the nanocomposites is attributable to the restricted movement of the polymeric chains on account of addition of carbon nanotubes.

  19. Configuration control based on risk matrix for radiotherapy treatment

    International Nuclear Information System (INIS)

    Montes de Oca Quinnones, Joe; Torres Valle, Antonio

    2015-01-01

    The incorporation of the science and technique breakthroughs in the application of the radiotherapy represents a challenge so that, the appearance of equipment failure or human mistakes that triggers unfavorable consequences for patients, public, or the occupationally exposed workers; it is also diversified forcing to incorporate besides, as part of the efforts, new techniques for the evaluation of risk and the detection of the weak points that can lead to these consequences. In order to evaluate the risks of the radiotherapy practices there is the SEVRRA code, based on the method of Risk Matrix. The system SEVRRA is the most frequently used code in the applications of risk studies in radiotherapy treatment. On the other hand, starting from the development of tools to control the dangerous configurations in nuclear power plants, it has been developed the SECURE code, which in its application variant of Risk Matrix, has gain a comfortable interface man-machine to make risk analyses to the radiotherapy treatment, molding in this way a lot of combinations of scenarios. These capacities outstandingly facilitate the studies and risk optimization applications in these practices. In the system SECURE-Risk Matrix are incorporated graphic and analytical capacities, which make more flexible the analyses and the subsequent documentation of all the results. The paper shows the the application of the proposed system to an integral risk study for the process of radiotherapy treatment with linear accelerator. (Author)

  20. Aluminothermic Reduction-Molten Salt Electrolysis Using Inert Anode for Oxygen and Al-Base Alloy Extraction from Lunar Soil Simulant

    Science.gov (United States)

    Xie, Kaiyu; Shi, Zhongning; Xu, Junli; Hu, Xianwei; Gao, Bingliang; Wang, Zhaowen

    2017-10-01

    Aluminothermic reduction-electrolysis using an inert anode process is proposed to extract oxygen and metals from Minnesota Lunar Simulant-1 (MLS-1). Effective aluminothermic reduction between dissolved MLS-1 and dissolved metal aluminum was achieved in cryolite salt media. The product phases obtained by aluminothermic reduction at 980°C for 4 h were Al, Si, and Al5FeSi, while the chemical components were 79.71 mass% aluminum, 12.03 mass% silicon, 5.91 mass% iron, and 2.35 mass% titanium. The cryolite salt containing Al2O3 was subsequently electrolyzed with Fe0.58-Ni0.42 inert anode at 960°C for 4 h. Oxygen was evolved at the anode with an anodic current efficiency of 78.28%. The results demonstrate that this two-step process is remarkably feasible for the extraterrestrial extraction of oxygen and metals. This process will help expand the existing in situ resource utilization methods.

  1. Compact optical multipass matrix system design based on slicer mirrors.

    Science.gov (United States)

    Guo, Yin; Sun, Liqun

    2018-02-10

    High path-to-volume ratio (PVR) and low-aberration-output beams are the two main criteria to assess the performance of multipass absorption cells. However, no substantial progress has been reported for large-numerical-aperture-coupled multipass cells, which is due to the accumulated aberrations caused by a large number of off-axis reflections. Based on Chernin's design, in this study, we modified Chernin's four-objective multipass matrix cell by using slicer mirrors to eliminate alignment difficulty and decrease the system volume. A generalized design routine based on user requirements is also proposed. Based on the automatic modeling tool package (Pyzdde) connected with Zemax and boundary conditions of the parameters selection proposed, a low-aberration-output beam and a high PVR are easily obtained compared with other multipass cells schemes. In one demo design, 108 passes (5×7 matrix spots) in a base length of 300 mm are presented. The PVR and peak-to-valley value wavefront errors are 67.5 m/L and 0.92 μm, respectively. Finally, a tolerance analysis of this optical multipass system is also presented. This work may provide better broadband optical absorption cells in terms of response time and a better detection sensitivity in versatile applications.

  2. Development and characterization of ceramic composites alumina-titania based reinforced with lanthanum oxide for fabrication of inert coatings for metallic tanks of the oil industry

    International Nuclear Information System (INIS)

    Bandeira, J.M.; Yadava, Y.P.; Silva, N.D.G.; Ferreira, R.A.S.

    2016-01-01

    Crude petroleum is highly corrosive causing superficial degradation in metallic tanks used for storage and transportation of this material, which causes a serious problem in the oil industry. An alternative to solve this problem is to use some kind of coating that is inert to this kind of corrosion. Alumina and titania are interesting materials for several engineering applications because, when compared with other ceramic materials, they present superior mechanical properties, e.g. high mechanical strength, good chemical stability and high fracture toughness combined with good wear resistance and a coefficient of thermal expansion close to the iron's, which makes them fit to use in ceramic hardening process and coating. In this paper, alumina-titania ceramic composites with 5%, 10%, 15% and 20% of titania (TiO2) and reinforced with 2% of lanthanum oxide of were produced by thermo-mechanical processing and sintering techniques at 1350 deg C. In these composites, microstructure and mechanical properties were analyzed using X-ray spectroscopy, optical microscopy, scanning electron microscopy and Vickers hardness in order to evaluate their applicability. X-ray spectroscopy showed the formation of composite without the presence of other phases. Optical microscopy and scanning electron microscopy showed a homogeneous microstructure in terms of particle size and distribution. Vickers hardness test showed a gradual decrease in hardness with the addition of titania. The composite with 5% of titania and 2% of lanthanum oxide is the best choice for structural applications. The composites were submerged in crude petroleum for 30 days to study their stability in such environment. Through the analysis of X-ray spectroscopy, optical microscopy and Vickers hardness before and after the submersion in crude petroleum, it was not observed structural or microstructural degradation nether alterations in mechanical properties. This way, it was concluded that these composites have

  3. Matrix converter based SICAM using an LC-network

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.

    2003-01-15

    In this internal report an analysis of the Matrix converter (MC) based SICAM using an LC-network for producing a second phase voltage is presented. It is shown that in order to allow proper operation of the MC using an LC-network, the latter must be properly loaded in some way. Topologies resulting from this constraint are analyzed in the beginning sections, where the load resistance emerges paralleled to the capacitor C or to the inductor L. Switching the MC at high frequency for creating the output audio voltage is presented using the state-space averaging principle. Design parameters are introduced and design considerations presented, which lead to easier construction of an MC-based SICAM. Design example is developed for supporting the design principle and extensive simulation is undertaken. Control issues and the influence of the output low-pass filter are separately investigated. (au)

  4. SKILLS-BASED ECLECTIC TECHNIQUES MATRIX FOR ELT MICROTEACHINGS

    Directory of Open Access Journals (Sweden)

    İskender Hakkı Sarıgöz

    2016-10-01

    Full Text Available Foreign language teaching undergoes constant changes due to the methodological improvement. This progress may be examined in two parts. They are the methods era and the post-methods era. It is not pragmatic today to propose a particular language teaching method and its techniques for all purposes. The holistic inflexibility of mid-century methods has long gone. In the present day, constructivist foreign language teaching trends attempt to see the learner as a whole person and an individual who may be different from the other students in many respects. At the same time, the individual differences should not keep the learners away from group harmony. For this reason, current teacher training programs require eclectic teaching matrixes for unit design considering the mixed ability student groups. These matrixes can be prepared in a multidimensional fashion because there are many functional techniques in different methods and other new techniques to be created by instructors freely in accordance with the teaching aims. The hypothesis in this argument is that the collection of foreign language teaching techniques compiled in ELT microteachings for a particular group of learners has to be arranged eclectically in order to update the teaching process. Nevertheless, designing a teaching format of this sort is a demanding and highly criticized task. This study briefly argues eclecticism in language-skills based methodological struggle from the perspective of ELT teacher education.

  5. Development and characterization of ceramic composites based on alumina-titania reinforced with rare earth oxide (holmium oxide) for the production of inert coatings in metal tanks of petroleum industry; Desenvolvimento e caracterizacao de compositos ceramicos baseados em alumina-titania reforcados com oxido de terra rara (oxido de holmio) para fabricacao de revestimentos inertes em tanques metalicos da industria petrolifera

    Energy Technology Data Exchange (ETDEWEB)

    Silva, N.D.G.; Pontual, J.O.; Ferreira, R.A.S.; Yadava, Y.P., E-mail: nokaa_demery@hotmail.com, E-mail: yadava@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Engenharia Mecanica

    2014-07-01

    Due to the importance of petroleum and its derivatives for modern society, it is necessary to develop technologies that improve processes and transports of petroleum. The crude oil creates hostile environments and in the process of transport and storage of petroleum are used metallic materials, which corrode becoming a critical problem in this industry. One way of solving this problem is the use of ceramics based on alumina as inert coating on hostile environments. In this work was studied a structure, microstructure and mechanical properties of ceramic composite based on Al2O3 - TiO2 reinforced Ho2O3. The composites were produced by a thermomechanical process, sintered at 1350°C, were analyzed by x-ray diffraction, optical microscopy, scanning electron microscopy, and microhardness. Analyses were performed before and after immersion in earth and offshore crude petroleum to study stability of the developed composites and concluded that the ceramic composites immersed in petroleum show stable in hostile environments. (author)

  6. [Continuum, the continuing education platform based on a competency matrix].

    Science.gov (United States)

    Ochoa Sangrador, C; Villaizán Pérez, C; González de Dios, J; Hijano Bandera, F; Málaga Guerrero, S

    2016-04-01

    Competency-Based Education is a learning method that has changed the traditional teaching-based focus to a learning-based one. Students are the centre of the process, in which they must learn to learn, solve problems, and adapt to changes in their environment. The goal is to provide learning based on knowledge, skills (know-how), attitude and behaviour. These sets of knowledge are called competencies. It is essential to have a reference of the required competencies in order to identify the need for them. Their acquisition is approached through teaching modules, in which one or more skills can be acquired. This teaching strategy has been adopted by Continuum, the distance learning platform of the Spanish Paediatric Association, which has developed a competency matrix based on the Global Paediatric Education Consortium training program. In this article, a review will be presented on the basics of Competency-Based Education and how it is applied in Continuum. Copyright © 2015 Asociación Española de Pediatría. Published by Elsevier España, S.L.U. All rights reserved.

  7. In-situ formation of nanoparticles within a silicon-based matrix

    Science.gov (United States)

    Thoma, Steven G [Albuquerque, NM; Wilcoxon, Jess P [Albuquerque, NM; Abrams, Billie L [Albuquerque, NM

    2008-06-10

    A method for encapsulating nanoparticles with an encapsulating matrix that minimizes aggregation and maintains favorable properties of the nanoparticles. The matrix comprises silicon-based network-forming compounds such as ormosils and polysiloxanes. The nanoparticles are synthesized from precursors directly within the silicon-based matrix.

  8. Mechanisms of inert gas narcosis

    Science.gov (United States)

    1973-01-01

    Experiments describing the mechanism of inert gas narcosis are reported. A strain of mice, genetically altered to increase susceptibility to botulin poisoning (synaptic response) appears to increase metabolic rates while breathing argon; this infers a genetically altered synaptic response to both botulin toxin and narcotic gases. Studies of metabolic depression in human subjects breathing either air or a 30% mixture of nitrous oxide indicate that nitrous oxide narcosis does not produce pronounced metabolic depression. Tests on mice for relative susceptibilities to narcosis and oxygen poisoning as a function of fatty membrane composition show that alteration of the fatty acid composition of phospholipids increases resistance to metabolically depressant effects of argon but bas no effect on nitrous oxide narcosis. Another study suggests that acclimatization to low tension prior to high pressure oxygen treatment enhances susceptibility of mice to convulsions and death; developing biochemical lesions cause CNS metabolite reductions and pulmonary damage.

  9. Image Jacobian Matrix Estimation Based on Online Support Vector Regression

    Directory of Open Access Journals (Sweden)

    Shangqin Mao

    2012-10-01

    Full Text Available Research into robotics visual servoing is an important area in the field of robotics. It has proven difficult to achieve successful results for machine vision and robotics in unstructured environments without using any a priori camera or kinematic models. In uncalibrated visual servoing, image Jacobian matrix estimation methods can be divided into two groups: the online method and the offline method. The offline method is not appropriate for most natural environments. The online method is robust but rough. Moreover, if the images feature configuration changes, it needs to restart the approximating procedure. A novel approach based on an online support vector regression (OL-SVR algorithm is proposed which overcomes the drawbacks and combines the virtues just mentioned.

  10. Wax-based sustained release matrix pellets prepared by a novel freeze pelletization technique I. Formulation and process variables affecting pellet characteristics.

    Science.gov (United States)

    Cheboyina, Sreekhar; Wyandt, Christy M

    2008-07-09

    A novel freeze pelletization technique was evaluated for the preparation of wax-based matrix pellets. Pellets containing either theophylline or diltiazem HCl were prepared using various waxes. In this technique, molten waxes along with a dispersed active ingredient were introduced as droplets into an inert and immiscible column of liquid to form pellets. An 80% (w/w) aqueous glycerol solution was found to be the most suitable column liquid for preparing spherical wax pellets. The physical stability of the molten wax suspensions was substantially improved by the addition of a 5% (w/w) colloidal silica gel. Pellet size obtained was directly proportional to the cubic root of the outer radius of the needle tip used to form pellets. Pellet size increased as the ratio of interfacial tension (gamma(LL)) to the density difference (Deltarho) between the molten matrix and the column liquid increased. Moreover, an increase in the drug load of theophylline increased the pellet size. However, an addition of a surfactant to the matrix slightly decreased the pellet size. Microscopic studies indicated that theophylline was homogenously dispersed throughout the matrix and existed in a crystalline state at higher drug loads. The percent drug recoveries ranged from 90.7 to 102.3% with acceptable drug loads up to 20% (w/w). Therefore, wax pellets containing drugs of varying aqueous solubility were successfully prepared using this technique.

  11. Newborn screening by matrix-assisted laser desorption/ionization mass spectrometry based on parylene-matrix chip.

    Science.gov (United States)

    Kim, Jo-Il; Noh, Joo-Yoon; Kim, Mira; Park, Jong-Min; Song, Hyun-Woo; Kang, Min-Jung; Pyun, Jae-Chul

    2017-08-01

    Newborn screening for diagnosis of phenylketonuria, homocystinuria, and maple syrup urine disease have been conducted by analyzing the concentration of target amino acids using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS) based on parylene-matrix chip. Parylene-matrix chip was applied to MALDI-ToF MS analysis reducing the matrix peaks significantly at low mass-to-charge ratio range (m/z  0.98) and the LODs were ranging from 9.0 to 22.9 μg/mL. Effect of proteins in serum was estimated by comparing MALDI-ToF mass spectra of amino acids-spiked serum before and after the methanol extraction. Interference of other amino acids on analysis of target analyte was determined to be insignificant. From these results, MALDI-ToF MS based on parylene-matrix chip could be applicable to medical diagnosis of neonatal metabolic disorders. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Observability of inert scalars at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Hashemi, Majid [Shiraz University, Physics Department, College of Sciences, Shiraz (Iran, Islamic Republic of); Najjari, Saereh [University of Warsaw, Faculty of Physics, Warsaw (Poland)

    2017-09-15

    In this work we investigate the observability of inert doublet model scalars at the LHC operating at the center of mass energy of 14 TeV. The signal production process is pp → AH{sup ±} → ZHW{sup ±}H leading to two different final states of l{sup +}l{sup -}HjjH and l{sup +}l{sup -}Hl{sup ±}νH based on the hadronic and leptonic decay channels of the W boson. All the relevant background processes are considered and an event selection is designed to distinguish the signal from the large Standard Model background. We found that signals of the selected search channels are well observable at the LHC with an integrated luminosity of 300 fb{sup -1}. (orig.)

  13. 46 CFR 154.904 - Inert gas system: Controls.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Inert gas system: Controls. 154.904 Section 154.904... Atmospheric Control in Cargo Containment Systems § 154.904 Inert gas system: Controls. The inert gas system... the inert gas system, or another means specially approved by the Commandant (CG-522); (b) If the inert...

  14. Random matrix-based dimensionality reduction for bioluminescence tomography reconstruction

    Science.gov (United States)

    Styles, Iain B.; Basevi, Hector R. A.; Guggenheim, James A.; Dehghani, Hamid

    2013-06-01

    We show how a random matrix can be used to reduce the dimensionality of the bioluminescence tomography reconstruction problem. A randomised low-rank approximation for the sensitivity matrix is computed, and we show how this can be used to reconstruct the bioluminescence source distribution on a randomised basis for the mesh nodes. The distribution on the original mesh can be found easily via a simple matrix multiplication. The majority of the computation required can be performed in advance of the reconstruction, and the reconstruction time itself is of the order milliseconds. This could allow for high frame rate real-time reconstructions to be performed.

  15. Milling of Nanoparticles Reinforced Al-Based Metal Matrix Composites

    Directory of Open Access Journals (Sweden)

    Alokesh Pramanik

    2018-03-01

    Full Text Available This study investigated the face milling of nanoparticles reinforced Al-based metal matrix composites (nano-MMCs using a single insert milling tool. The effects of feed and speed on machined surfaces in terms of surface roughness, surface profile, surface appearance, chip surface, chip ratio, machining forces, and force signals were analyzed. It was found that surface roughness of machined surfaces increased with the increase of feed up to the speed of 60 mm/min. However, at the higher speed (100–140 mm/min, the variation of surface roughness was minor with the increase of feed. The machined surfaces contained the marks of cutting tools, lobes of material flow in layers, pits and craters. The chip ratio increased with the increase of feed at all speeds. The top chip surfaces were full of wrinkles in all cases, though the bottom surfaces carried the evidence of friction, adhesion, and deformed material layers. The effect of feed on machining forces was evident at all speeds. The machining speed was found not to affect machining forces noticeably at a lower feed, but those decreased with the increase of speed for the high feed scenario.

  16. A new understanding of inert gas narcosis

    International Nuclear Information System (INIS)

    Zhang Meng; Gao Yi; Fang Haiping

    2016-01-01

    Anesthetics are extremely important in modern surgery to greatly reduce the patient’s pain. The understanding of anesthesia at molecular level is the preliminary step for the application of anesthetics in clinic safely and effectively. Inert gases, with low chemical activity, have been found to cause anesthesia for centuries, but the mechanism is unclear yet. In this review, we first summarize the progress of theories about general anesthesia, especially for inert gas narcosis, and then propose a new hypothesis that the aggregated rather than the dispersed inert gas molecules are the key to trigger the narcosis to explain the steep dose-response relationship of anesthesia. (topical review)

  17. Degenerated-Inverse-Matrix-Based Channel Estimation for OFDM Systems

    Directory of Open Access Journals (Sweden)

    Makoto Yoshida

    2009-01-01

    Full Text Available This paper addresses time-domain channel estimation for pilot-symbol-aided orthogonal frequency division multiplexing (OFDM systems. By using a cyclic sinc-function matrix uniquely determined by Nc transmitted subcarriers, the performance of our proposed scheme approaches perfect channel state information (CSI, within a maximum of 0.4 dB degradation, regardless of the delay spread of the channel, Doppler frequency, and subcarrier modulation. Furthermore, reducing the matrix size by splitting the dispersive channel impulse response into clusters means that the degenerated inverse matrix estimator (DIME is feasible for broadband, high-quality OFDM transmission systems. In addition to theoretical analysis on normalized mean squared error (NMSE performance of DIME, computer simulations over realistic nonsample spaced channels also showed that the DIME is robust for intersymbol interference (ISI channels and fast time-invariant channels where a minimum mean squared error (MMSE estimator does not work well.

  18. Liquid Fuel Combustion Using Porous Inert Media

    National Research Council Canada - National Science Library

    Agrawal, Ajay K; Gollahalli, Subramanayam R

    2006-01-01

    Combustion using porous inert media (PIM) offers benefits such as high power density, stable operation over a wider turndown ratio, homogeneous product gases, lower combustion noise and reduced emissions of NOx, CO, particulates, etc...

  19. Discriminatory Data Mapping by Matrix-Based Supervised Learning Metrics

    NARCIS (Netherlands)

    Strickert, M.; Schneider, P.; Keilwagen, J.; Villmann, T.; Biehl, M.; Hammer, B.

    2008-01-01

    Supervised attribute relevance detection using cross-comparisons (SARDUX), a recently proposed method for data-driven metric learning, is extended from dimension-weighted Minkowski distances to metrics induced by a data transformation matrix Ω for modeling mutual attribute dependence. Given class

  20. Network Coding Parallelization Based on Matrix Operations for Multicore Architectures

    DEFF Research Database (Denmark)

    Wunderlich, Simon; Cabrera, Juan; Fitzek, Frank

    2015-01-01

    such as the Raspberry Pi2 with four cores in the order of up to one full magnitude. The speed increase gain is even higher than the number of cores of the Raspberry Pi2 since the newly introduced approach exploits the cache architecture way better than by-the-book matrix operations. Copyright © 2015 by the Institute...

  1. Structured matrix based methods for approximate polynomial GCD

    CERN Document Server

    Boito, Paola

    2011-01-01

    Defining and computing a greatest common divisor of two polynomials with inexact coefficients is a classical problem in symbolic-numeric computation. The first part of this book reviews the main results that have been proposed so far in the literature. As usual with polynomial computations, the polynomial GCD problem can be expressed in matrix form: the second part of the book focuses on this point of view and analyses the structure of the relevant matrices, such as Toeplitz, Toepliz-block and displacement structures. New algorithms for the computation of approximate polynomial GCD are presented, along with extensive numerical tests. The use of matrix structure allows, in particular, to lower the asymptotic computational cost from cubic to quadratic order with respect to polynomial degree. .

  2. Spatio-Temporal Audio Enhancement Based on IAA Noise Covariance Matrix Estimates

    DEFF Research Database (Denmark)

    Nørholm, Sidsel Marie; Jensen, Jesper Rindom; Christensen, Mads Græsbøll

    2014-01-01

    A method for estimating the noise covariance matrix in a mul- tichannel setup is proposed. The method is based on the iter- ative adaptive approach (IAA), which only needs short seg- ments of data to estimate the covariance matrix. Therefore, the method can be used for fast varying signals. The m...

  3. Fast matrix factorization algorithm for DOSY based on the eigenvalue decomposition and the difference approximation focusing on the size of observed matrix

    International Nuclear Information System (INIS)

    Tanaka, Yuho; Uruma, Kazunori; Furukawa, Toshihiro; Nakao, Tomoki; Izumi, Kenya; Utsumi, Hiroaki

    2017-01-01

    This paper deals with an analysis problem for diffusion-ordered NMR spectroscopy (DOSY). DOSY is formulated as a matrix factorization problem of a given observed matrix. In order to solve this problem, a direct exponential curve resolution algorithm (DECRA) is well known. DECRA is based on singular value decomposition; the advantage of this algorithm is that the initial value is not required. However, DECRA requires a long calculating time, depending on the size of the given observed matrix due to the singular value decomposition, and this is a serious problem in practical use. Thus, this paper proposes a new analysis algorithm for DOSY to achieve a short calculating time. In order to solve matrix factorization for DOSY without using singular value decomposition, this paper focuses on the size of the given observed matrix. The observed matrix in DOSY is also a rectangular matrix with more columns than rows, due to limitation of the measuring time; thus, the proposed algorithm transforms the given observed matrix into a small observed matrix. The proposed algorithm applies the eigenvalue decomposition and the difference approximation to the small observed matrix, and the matrix factorization problem for DOSY is solved. The simulation and a data analysis show that the proposed algorithm achieves a lower calculating time than DECRA as well as similar analysis result results to DECRA. (author)

  4. Chemical Stability of the Fiber Coating/Matrix Interface in Silicon-Based Ceramic Matrix Composites

    Science.gov (United States)

    Lee, Kang N.; Jacobson, Nathan S.

    1995-01-01

    Carbon and boron nitride are used as fiber coatings in silicon-based composites. In order to assess the long-term stability of these materials, reactions of carbon/Si3N4 and BN/SiC were studied at high temperatures with Knudsen effusion, coupon tests, and microstructural examination. In the carbon/Si3N4 system, carbon reacted with Si3N4 to form gaseous N2 and SiC. The formation of SiC limited further reaction by physically separating the carbon and Si3N4. Consequently, the development of high p(N2) at the interface, predicted from thermochemical calculations, did not occur, thus limiting the potential deleterious effects of the reaction on the composite. Strong indications of a reaction between BN and SiC were shown by TEM and SIMS analysis of the BN/SiC interface. In long-term exposures, this reaction can lead to a depletion of a BN coating and/or an unfavorable change of the interfacial properties, limiting the beneficial effects of the coating.

  5. Inert gas effects on embryonic development.

    Science.gov (United States)

    Weiss, H. S.; Grimard, M.

    1972-01-01

    It had been found in previous investigations that hatchability of fertile chicken eggs is reduced to 50% or less of controls if incubation takes place in a low nitrogen atmosphere containing He. Although these results suggest some role for nitrogen in embryogenesis, it is possible that a requirement exists for an inert molecule closer in physical characteristics to nitrogen than is He. An investigation is conducted involving incubation at ground level pressure in a gas mixture in which the 79% inert component was either neon or argon. The effect of varying combinations of nitrogen, helium, and oxygen was also studied.

  6. A purification process for an inert gas system

    International Nuclear Information System (INIS)

    Raj, S.S.; Samanta, S.K.; Jain, N.G.; Deshingkar, D.S.; Ramaswamy, M.

    1984-01-01

    Special inert atmosphere is desired inside hot cells used for handling radioactive materials. In this report, details of experiments conducted to generate data required for the design of a system for maintaining very low levels of organic and acid vapours, oxygen and moisture in a nitrogen gas inert atmosphere, are described. Several grades of activated charcoals impregnated with 1% KOH were studied for the adsorption of acidic and organic vapours. A Pd/Al 2 O 3 catalyst was developed to remove oxygen with greater than 90% efficiency. For the removal of moisture, a regenerable molecular sieve 4A dual-bed was provided. Based on the performance data thus generated, an integrated purification system for nitrogen gas is proposed. (author)

  7. Wear behaviour of Zr-based in situ bulk metallic glass matrix ...

    Indian Academy of Sciences (India)

    based bulk metallic glass (BMG) and its in situ BMG matrix composites with diameter of 3 mm were fabricated by conventional Cu-mould casting method and ... The composites showed lower friction coefficient and wear rate than the pure BMG.

  8. An enhanced matrix-free edge-based finite volume approach to model structures

    CSIR Research Space (South Africa)

    Suliman, Ridhwaan

    2010-01-01

    Full Text Available This paper presents the formulation, implementation and evaluation of an enhanced matrix free edge-based finite volume approach to model the mechanics of solids undergoing large non-linear deformations. The developed technology is evaluated via...

  9. Evaluation of roll compaction as a preparation method for hydroxypropyl cellulose-based matrix tablets

    Directory of Open Access Journals (Sweden)

    Imjak Jeon

    2011-01-01

    Full Text Available Roll compaction was applied for the preparation of hydroxypropyl cellulose (HPC-based sustained-release matrix tablets. Matrix tablets made via roll compaction exhibited higher dosage uniformity and faster drug release than direct-compacted tablets. HPC viscosity grade, roll pressure, and milling speed affected tablet properties significantly. Roll compaction seems to be an adequate granulation method for the preparation of HPC-based matrix tablets due to the simplicity of the process, less handling difficulty from HPC tackiness as well as easier particle size targeting. Selecting the optimum ratio of plastic excipients and the particle size of starting materials can however be critical issues in this method.

  10. Mechanical properties of aluminium based metal matrix composites reinforced with graphite nanoplatelets

    Energy Technology Data Exchange (ETDEWEB)

    Alam, Syed Nasimul, E-mail: syedn@nitrkl.ac.in; Kumar, Lailesh

    2016-06-14

    In this work Al-matrix composites reinforced by exfoliated graphite nanoplatelets (xGnP) is fabricated by powder metallurgy route and their microstructure, mechanical properties and sliding wear behaviour were investigated. Here, xGnP has been synthesized from the thermally exfoliated graphite produced from a graphite intercalation compound (GIC) through rapid evaporation of the intercalant at an elevated temperature. The xGnP synthesized was characterized using scanning electron microscope (SEM), high-resolution transmission electron microscope (HRTEM), x-ray diffraction (XRD), atomic force microscopy (AFM), x-ray photoelectron spectroscopy (XPS), differential scanning calorimetry and thermogravimetric analysis (DSC/TGA), Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR). The Al and xGnP powder mixtures were consolidated under a load of 565 MPa followed by sintering at 550 °C for 2 h in an inert atmosphere. Al-1, 2, 3 and 5 wt% xGnP nanocomposites were developed. Results of the wear test show that there was a significant improvement in the wear resistance of the composites up to the addition of 3 wt% of xGnP in the Al matrix. The hardness of the various Al-xGnP composites also shows improvement upto the addition of 1 wt% xGnP beyond which there was a decrease in the hardness of the composites. The tensile strength of the Al-xGnP composites continuously reduced with the addition of xGnP due to the formation of Al{sub 4}C{sub 3} particles at the interface of the Al and xGnP in the composite.

  11. temperature fluctuation inside inert atmosphere silos

    African Journals Online (AJOL)

    user

    gas until the residual oxygen content is reduced to almost 0%. The preference of nitrogen to other inert ... and the surrounding, material of construction and grain agitation. Temperature differential is higher in ... hazards to operators and toxic chemical residues on crops; it reduces grain respiration; it reduces oxidative ...

  12. 7 CFR 201.51 - Inert matter.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Inert matter. 201.51 Section 201.51 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... other sclerotia. (2) Soil particles, sand, stone, chaff, stems, leaves, flowers, loose coating material...

  13. Equation of state for inert gas solids

    Indian Academy of Sciences (India)

    The equation of state is a fundamental relation to analyse the thermophysical properties of different class of solids and it plays a key role in basic and applied condensed matter physics research. A lot of work has been done in the field of ionic solids, minerals and metals but a very little work is done in the field of inert gas ...

  14. temperature fluctuation inside inert atmosphere silos

    African Journals Online (AJOL)

    This research was conducted to study temperature fluctuation inside the inert atmosphere silos loaded with wheat, compare the temperature fluctuation across the top, middle and bottom part of the silo in relation to the ambient temperature. Temperature readings of the ambient and at the top, middle and bottom part of the ...

  15. Biomimetic Mineralization on a Macroporous Cellulose-Based Matrix for Bone Regeneration

    Directory of Open Access Journals (Sweden)

    Odeta Petrauskaite

    2013-01-01

    Full Text Available The aim of this study is to investigate the biomimetic mineralization on a cellulose-based porous matrix with an improved biological profile. The cellulose matrix was precalcified using three methods: (i cellulose samples were treated with a solution of calcium chloride and diammonium hydrogen phosphate; (ii the carboxymethylated cellulose matrix was stored in a saturated calcium hydroxide solution; (iii the cellulose matrix was mixed with a calcium silicate solution in order to introduce silanol groups and to combine them with calcium ions. All the methods resulted in a mineralization of the cellulose surfaces after immersion in a simulated body fluid solution. Over a period of 14 days, the matrix was completely covered with hydroxyapatite crystals. Hydroxyapatite formation depended on functional groups on the matrix surface as well as on the precalcification method. The largest hydroxyapatite crystals were obtained on the carboxymethylated cellulose matrix treated with calcium hydroxide solution. The porous cellulose matrix was not cytotoxic, allowing the adhesion and proliferation of human osteoblastic cells. Comparatively, improved cell adhesion and growth rate were achieved on the mineralized cellulose matrices.

  16. Extracellular matrix-based biomaterial scaffolds and the host response.

    Science.gov (United States)

    Aamodt, Joseph M; Grainger, David W

    2016-04-01

    Extracellular matrix (ECM) collectively represents a class of naturally derived proteinaceous biomaterials purified from harvested organs and tissues with increasing scientific focus and utility in tissue engineering and repair. This interest stems predominantly from the largely unproven concept that processed ECM biomaterials as natural tissue-derived matrices better integrate with host tissue than purely synthetic biomaterials. Nearly every tissue type has been decellularized and processed for re-use as tissue-derived ECM protein implants and scaffolds. To date, however, little consensus exists for defining ECM compositions or sources that best constitute decellularized biomaterials that might better heal, integrate with host tissues and avoid the foreign body response (FBR). Metrics used to assess ECM performance in biomaterial implants are arbitrary and contextually specific by convention. Few comparisons for in vivo host responses to ECM implants from different sources are published. This review discusses current ECM-derived biomaterials characterization methods including relationships between ECM material compositions from different sources, properties and host tissue response as implants. Relevant preclinical in vivo models are compared along with their associated advantages and limitations, and the current state of various metrics used to define material integration and biocompatibility are discussed. Commonly applied applications of these ECM-derived biomaterials as stand-alone implanted matrices and devices are compared with respect to host tissue responses. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. A new Expert Finding model based on Term Correlation Matrix

    Directory of Open Access Journals (Sweden)

    Ehsan Pornour

    2015-09-01

    Full Text Available Due to the enormous volume of unstructured information available on the Web and inside organization, finding an answer to the knowledge need in a short time is difficult. For this reason, beside Search Engines which don’t consider users individual characteristics, Recommender systems were created which use user’s previous activities and other individual characteristics to help users find needed knowledge. Recommender systems usage is increasing every day. Expert finder systems also by introducing expert people instead of recommending information to users have provided this facility for users to ask their questions form experts. Having relation with experts not only causes information transition, but also with transferring experiences and inception causes knowledge transition. In this paper we used university professors academic resume as expert people profile and then proposed a new expert finding model that recommends experts to users query. We used Term Correlation Matrix, Vector Space Model and PageRank algorithm and proposed a new hybrid model which outperforms conventional methods. This model can be used in internet environment, organizations and universities that experts have resume dataset.

  18. Development and characterization of ceramic composites alumina-titania based reinforced with lanthanum oxide for fabrication of inert coatings for metallic tanks of the oil industry; Desenvolvimento e caracterizacao de compositos ceramicos baseados em alumina-titania reforcados com oxido de lantanio para fabricacao de revestimentos inertes em tanques metalicos da industria petrolifera

    Energy Technology Data Exchange (ETDEWEB)

    Bandeira, J.M.; Yadava, Y.P.; Silva, N.D.G.; Ferreira, R.A.S., E-mail: julianamb91@gmail.com, E-mail: yadava@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Centro de Tecnologia e Geociencias. Departamento de Engenharia Mecanica

    2016-07-01

    Crude petroleum is highly corrosive causing superficial degradation in metallic tanks used for storage and transportation of this material, which causes a serious problem in the oil industry. An alternative to solve this problem is to use some kind of coating that is inert to this kind of corrosion. Alumina and titania are interesting materials for several engineering applications because, when compared with other ceramic materials, they present superior mechanical properties, e.g. high mechanical strength, good chemical stability and high fracture toughness combined with good wear resistance and a coefficient of thermal expansion close to the iron's, which makes them fit to use in ceramic hardening process and coating. In this paper, alumina-titania ceramic composites with 5%, 10%, 15% and 20% of titania (TiO2) and reinforced with 2% of lanthanum oxide of were produced by thermo-mechanical processing and sintering techniques at 1350 deg C. In these composites, microstructure and mechanical properties were analyzed using X-ray spectroscopy, optical microscopy, scanning electron microscopy and Vickers hardness in order to evaluate their applicability. X-ray spectroscopy showed the formation of composite without the presence of other phases. Optical microscopy and scanning electron microscopy showed a homogeneous microstructure in terms of particle size and distribution. Vickers hardness test showed a gradual decrease in hardness with the addition of titania. The composite with 5% of titania and 2% of lanthanum oxide is the best choice for structural applications. The composites were submerged in crude petroleum for 30 days to study their stability in such environment. Through the analysis of X-ray spectroscopy, optical microscopy and Vickers hardness before and after the submersion in crude petroleum, it was not observed structural or microstructural degradation nether alterations in mechanical properties. This way, it was concluded that these composites have

  19. Iterative reconstruction using a Monte Carlo based system transfer matrix for dedicated breast positron emission tomography

    International Nuclear Information System (INIS)

    Saha, Krishnendu; Straus, Kenneth J.; Glick, Stephen J.; Chen, Yu.

    2014-01-01

    To maximize sensitivity, it is desirable that ring Positron Emission Tomography (PET) systems dedicated for imaging the breast have a small bore. Unfortunately, due to parallax error this causes substantial degradation in spatial resolution for objects near the periphery of the breast. In this work, a framework for computing and incorporating an accurate system matrix into iterative reconstruction is presented in an effort to reduce spatial resolution degradation towards the periphery of the breast. The GATE Monte Carlo Simulation software was utilized to accurately model the system matrix for a breast PET system. A strategy for increasing the count statistics in the system matrix computation and for reducing the system element storage space was used by calculating only a subset of matrix elements and then estimating the rest of the elements by using the geometric symmetry of the cylindrical scanner. To implement this strategy, polar voxel basis functions were used to represent the object, resulting in a block-circulant system matrix. Simulation studies using a breast PET scanner model with ring geometry demonstrated improved contrast at 45% reduced noise level and 1.5 to 3 times resolution performance improvement when compared to MLEM reconstruction using a simple line-integral model. The GATE based system matrix reconstruction technique promises to improve resolution and noise performance and reduce image distortion at FOV periphery compared to line-integral based system matrix reconstruction

  20. Iterative reconstruction using a Monte Carlo based system transfer matrix for dedicated breast positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Krishnendu [Ohio Medical Physics Consulting, Dublin, Ohio 43017 (United States); Straus, Kenneth J.; Glick, Stephen J. [Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655 (United States); Chen, Yu. [Department of Radiation Oncology, Columbia University, New York, New York 10032 (United States)

    2014-08-28

    To maximize sensitivity, it is desirable that ring Positron Emission Tomography (PET) systems dedicated for imaging the breast have a small bore. Unfortunately, due to parallax error this causes substantial degradation in spatial resolution for objects near the periphery of the breast. In this work, a framework for computing and incorporating an accurate system matrix into iterative reconstruction is presented in an effort to reduce spatial resolution degradation towards the periphery of the breast. The GATE Monte Carlo Simulation software was utilized to accurately model the system matrix for a breast PET system. A strategy for increasing the count statistics in the system matrix computation and for reducing the system element storage space was used by calculating only a subset of matrix elements and then estimating the rest of the elements by using the geometric symmetry of the cylindrical scanner. To implement this strategy, polar voxel basis functions were used to represent the object, resulting in a block-circulant system matrix. Simulation studies using a breast PET scanner model with ring geometry demonstrated improved contrast at 45% reduced noise level and 1.5 to 3 times resolution performance improvement when compared to MLEM reconstruction using a simple line-integral model. The GATE based system matrix reconstruction technique promises to improve resolution and noise performance and reduce image distortion at FOV periphery compared to line-integral based system matrix reconstruction.

  1. Development of a parametric matrix based on GSCM literature

    Directory of Open Access Journals (Sweden)

    M. B. Nidhi

    2016-11-01

    Full Text Available Today Green Supply Chain Management (GSCM still remains as an attempt alone. For more than a decade, supply chain evolution to be a low carbon chain in an energy and resource constrained world has been posing greater challenges. Though environmental policies remain without much variation towards green operations in an industry, the implantation strategies and stages vary. There have been a number of studies by researchers and a lot of endeavors by organizations to build a green supply chain, mainly because of pressure from the professional bodies like EPA, WEEE, OECD, and Clean Air Act to reduce emissions with growing concerns over climate change issues, global warming, and requirements from policy makers, end users, stake holders and others. But, at the implementation level there lacked a proper framework on GSCM which suggests guidelines for proper planning and coordination, and the practices to be adopted. This indicates the need for a complete strategic approach on the part of decision makers across the supply chain to have sustainability as a corporate social responsibility. The research gap exists in a holistic perception with regard to a product when supply chain stages are mapped for sustainability due to diverse environmental issues. Also, to build a holistic approach, we must know how the stages and levels interact. Thus, in this work, a Parametric Matrix demarking various level and stages of a supply chain related to a product, in general, is developed from various literatures till date. Such a metric will be useful for the industries to identify the bottleneck areas in their supply chain towards sustainability. Hence, the desired and relevant level of factors to be considered at each stage to become green can easily be decided.

  2. Comparative Studies of Different Control Strategies of a Dynamic Voltage Restorer Based on Matrix Converter

    Directory of Open Access Journals (Sweden)

    Amin Shabanpour

    2012-01-01

    Full Text Available A dynamic voltage restorer (DVR with no energy storage is studied. By using a matrix converter instead of the conventional AC/DC/AC converters, elimination of the DC-link capacitor is possible. The switching algorithm of matrix converter is the space vector modulation. There are different compensation algorithms to control the conventional DVR. These methods have been analyzed in this paper for the proposed matrix-converter-based DVR. A deep analysis through different diagrams would show the advantages or disadvantages of each compensation method. Equations for all methods are derived, and the characteristics of algorithms are compared with each other.

  3. Risk Matrix-Based Method for Critical Infrastructure Safety Assessment Taking into Account Interdependencies

    Directory of Open Access Journals (Sweden)

    Brezhnev Eugene

    2016-01-01

    Full Text Available This paper is devoted to development of method for critical infrastructure (CI safety assessment taking into account the different types of interdependencies: logical, physical, geographical, etc. There are many existing approaches for CI safety assessment. But the limited number of them consider the interdependencies focused on safety. Only few of them focus on interdependencies formalization. The suggested approach is based on application of risk matrixes built for each CI systems. Criticality of state is considered as safety value. The risk matrixes are developed for each CI life stage. The initial risk matrix is developed during CI design stage. All operational risk matrixes are built based on fuzzy logic and system field data.

  4. Characteristic analysis on UAV-MIMO channel based on normalized correlation matrix.

    Science.gov (United States)

    Gao, Xi jun; Chen, Zi li; Hu, Yong Jiang

    2014-01-01

    Based on the three-dimensional GBSBCM (geometrically based double bounce cylinder model) channel model of MIMO for unmanned aerial vehicle (UAV), the simple form of UAV space-time-frequency channel correlation function which includes the LOS, SPE, and DIF components is presented. By the methods of channel matrix decomposition and coefficient normalization, the analytic formula of UAV-MIMO normalized correlation matrix is deduced. This formula can be used directly to analyze the condition number of UAV-MIMO channel matrix, the channel capacity, and other characteristic parameters. The simulation results show that this channel correlation matrix can be applied to describe the changes of UAV-MIMO channel characteristics under different parameter settings comprehensively. This analysis method provides a theoretical basis for improving the transmission performance of UAV-MIMO channel. The development of MIMO technology shows practical application value in the field of UAV communication.

  5. Characteristic Analysis on UAV-MIMO Channel Based on Normalized Correlation Matrix

    Science.gov (United States)

    Xi jun, Gao; Zi li, Chen; Yong Jiang, Hu

    2014-01-01

    Based on the three-dimensional GBSBCM (geometrically based double bounce cylinder model) channel model of MIMO for unmanned aerial vehicle (UAV), the simple form of UAV space-time-frequency channel correlation function which includes the LOS, SPE, and DIF components is presented. By the methods of channel matrix decomposition and coefficient normalization, the analytic formula of UAV-MIMO normalized correlation matrix is deduced. This formula can be used directly to analyze the condition number of UAV-MIMO channel matrix, the channel capacity, and other characteristic parameters. The simulation results show that this channel correlation matrix can be applied to describe the changes of UAV-MIMO channel characteristics under different parameter settings comprehensively. This analysis method provides a theoretical basis for improving the transmission performance of UAV-MIMO channel. The development of MIMO technology shows practical application value in the field of UAV communication. PMID:24977185

  6. Synthesis and Characterization of Pine Needles Reinforced RF Matrix Based Biocomposites

    OpenAIRE

    Singha, A. S.; Thakur, Vijay Kumar

    2008-01-01

    Synthesis and characterization of pine needles reinforced thermosetting resin (Resorcinol-Formaldehyde) which is most suitable as composite matrix has been reported. The polycondensation reaction between resorcinol and formaldehyde (RF) in different molar ratios has been applied to the synthesis of RF polymer matrix. A thermosetting resin based composite, containing approximately 10, 20, 30 and 40% of natural fiber by weight, has been obtained by adding pine needles to the Resorcinol-Formalde...

  7. NEW METHODS FOR IMPLANT MATRIX FORMATION BASED ON ELECTROSPINNING AND BIOPRINTING TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    V. N. Vasilets

    2009-01-01

    Full Text Available New implant materials for regenerative and replacement surgery based on biodegradable polymers like collagens and polyoxybutirates are developed. Porous structures with controllable morphology were formed from biodegradable polymers using electrospinning and bioprinting technologies. The matrixes were studied by visible and electron scanning microscopy as well as INTEGRA Tomo scanning probe platform making possible the restoration of inner 3D structure of polymer matrix

  8. The Visual Matrix Method: Imagery and Affect in a Group-Based Research Setting

    Directory of Open Access Journals (Sweden)

    Lynn Froggett

    2015-07-01

    Full Text Available The visual matrix is a method for researching shared experience, stimulated by sensory material relevant to a research question. It is led by imagery, visualization and affect, which in the matrix take precedence over discourse. The method enables the symbolization of imaginative and emotional material, which might not otherwise be articulated and allows "unthought" dimensions of experience to emerge into consciousness in a participatory setting. We describe the process of the matrix with reference to the study "Public Art and Civic Engagement" (FROGGETT, MANLEY, ROY, PRIOR & DOHERTY, 2014 in which it was developed and tested. Subsequently, examples of its use in other contexts are provided. Both the matrix and post-matrix discussions are described, as is the interpretive process that follows. Theoretical sources are highlighted: its origins in social dreaming; the atemporal, associative nature of the thinking during and after the matrix which we describe through the Deleuzian idea of the rhizome; and the hermeneutic analysis which draws from object relations theory and the Lorenzerian tradition of scenic understanding. The matrix has been conceptualized as a "scenic rhizome" to account for its distinctive quality and hybrid origins in research practice. The scenic rhizome operates as a "third" between participants and the "objects" of contemplation. We suggest that some of the drawbacks of other group-based methods are avoided in the visual matrix—namely the tendency for inter-personal dynamics to dominate the event. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs150369

  9. Advanced On Board Inert Gas Generation System (OBBIGS), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Valcor Engineering Corporation proposes to develop an advanced On Board Inert Gas Generation System, OBIGGS, for aircraft fuel tank inerting to prevent hazardous...

  10. Advanced On Board Inert Gas Generation System (OBBIGS), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Valcor Engineering Corporation proposes to develop an advanced On Board Inert Gas Generation System, OBIGGS, for aircraft fuel tank inerting to prevent hazardous...

  11. Fast near infra-red ferroelectric liquid crystal based Mueller matrix system for imaging and spectroscopy

    Directory of Open Access Journals (Sweden)

    Lindgren M.

    2010-06-01

    Full Text Available The science and optical engineering of imaging Mueller Matrix Ellipsometry (MME and Spectroscopic MME is currently being revitalized based on an efficient optimal design method, and through the use of the so-called Eig envalue Calibration Technique (ECT. Through the ECT one may efficiently measure the details of the polarization state generator (PSG matrix, and the polarization state analyzer (PSA matrix, and hence avoid modeling of any unknown polarizing components in the system, and in particular the exact response of complex polarizing elements such as liquid crystal retarders. We here start up with presenting a detailed an alysis of the dynamic response of a near infrared Ferroelectric Liquid Crystal based Mueller matrix ellipsometer (NIR FLC- MME [1] . A time dependent simulation model, using the measured time response of the individual FLCs, is used to describe the measured temporal response. Furthermore, the impulse response of the detector and the pre-amplifier is characterized and in cluded in the simulation model. The measured time dependent intensity response of the MME is well explained by simulations. A FLC based NIRMME system is here shown to be able to operate accurately at the maximum speed of approximately 16 ms per Mueller matrix measurement (steady state response. We demonstrate here time dependent Mueller Matrix measurements of a dynamically changing sample, with even down to 8 ms sampling time of each complete Mueller Matrix (with some loss of accuracy. We secondly briefly present the NIR-FLC- MME imaging system, and show applications to strain imaging of a crystal subjected to an external pressure. Furthermore, we present near-infra-red Mueller matrix images and corresponding polar decomposition images of thin slices of bio-tissue [2].

  12. Uniformity Masks Design Method Based on the Shadow Matrix for Coating Materials with Different Condensation Characteristics

    Directory of Open Access Journals (Sweden)

    Lichao Zhang

    2013-01-01

    Full Text Available An intuitionistic method is proposed to design shadow masks to achieve thickness profile control for evaporation coating processes. The proposed method is based on the concept of the shadow matrix, which is a matrix that contains coefficients that build quantitive relations between shape parameters of masks and shadow quantities of substrate directly. By using the shadow matrix, shape parameters of shadow masks could be derived simply by solving a matrix equation. Verification experiments were performed on a special case where coating materials have different condensation characteristics. By using the designed mask pair with complementary shapes, thickness uniformities of better than 98% are demonstrated for MgF2 ( and LaF3 ( simultaneously on a 280 mm diameter spherical substrate with the radius curvature of 200 mm.

  13. Mechanical and corrosion behaviors of developed copper-based metal matrix composites

    Science.gov (United States)

    Singh, Manvandra Kumar; Gautam, Rakesh Kumar; Prakash, Rajiv; Ji, Gopal

    2018-03-01

    This work investigates mechanical properties and corrosion resistances of cast copper-tungsten carbide (WC) metal matrix composites (MMCs). Copper matrix composites have been developed by stir casting technique. Different sizes of micro and nano particles of WC particles are utilized as reinforcement to prepare two copper-based composites, however, nano size of WC particles are prepared by high-energy ball milling. XRD (X-rays diffraction) characterize the materials for involvement of different phases. The mechanical behavior of composites has been studied by Vickers hardness test and compression test; while the corrosion behavior of developed composites is investigated by electrochemical impedance spectroscopy in 0.5 M H2SO4 solutions. The results show that hardness, compressive strength and corrosion resistance of copper matrix composites are very high in comparison to that of copper matrix, which attributed to the microstructural changes occurred during composite formation. SEM (Scanning electron microscopy) reveals the morphology of the corroded surfaces.

  14. Aroma behaviour during steam cooking within a potato starch-based model matrix.

    Science.gov (United States)

    Descours, Emilie; Hambleton, Alicia; Kurek, Mia; Debeaufort, Fréderic; Voilley, Andrée; Seuvre, Anne-Marie

    2013-06-05

    To help understand the organoleptic qualities of steam cooked foods, the kinetics of aroma release during cooking in a potato starch based model matrix was studied. Behaviour of components having a major impact in potato flavour were studied using solid phase micro extraction-gas chromatography (SPME-GC). Evolution of microstructure of potato starch model-matrix during steam cooking process was analyzed using environmental scanning electron microscopy (ESEM). Both aroma compounds that are naturally present in starch matrix and those that were added were analyzed. Both the aroma compounds naturally presented and those added had different behaviour depending on their physico-chemical properties (hydrophobicity, saturation vapour pressure, molecular weight, etc.). The physical state of potato starch influences of the retention of aromatized matrix with Starch gelatinization appearing to be the major phenomenon influencing aroma release. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. A new understanding of inert gas narcosis

    Science.gov (United States)

    Meng, Zhang; Yi, Gao; Haiping, Fang

    2016-01-01

    Anesthetics are extremely important in modern surgery to greatly reduce the patient’s pain. The understanding of anesthesia at molecular level is the preliminary step for the application of anesthetics in clinic safely and effectively. Inert gases, with low chemical activity, have been found to cause anesthesia for centuries, but the mechanism is unclear yet. In this review, we first summarize the progress of theories about general anesthesia, especially for inert gas narcosis, and then propose a new hypothesis that the aggregated rather than the dispersed inert gas molecules are the key to trigger the narcosis to explain the steep dose-response relationship of anesthesia. Project supported by the Supercomputing Center of Chinese Academy of Sciences in Beijing, China, the Shanghai Supercomputer Center, China, the National Natural Science Foundation of China (Grant Nos. 21273268, 11290164, and 11175230), the Startup Funding from Shanghai Institute of Applied Physics, Chinese Academy of Sciences (Grant No. Y290011011), “Hundred People Project” from Chinese Academy of Sciences, and “Pu-jiang Rencai Project” from Science and Technology Commission of Shanghai Municipality, China (Grant No. 13PJ1410400).

  16. 46 CFR 154.910 - Inert gas piping: Location.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Inert gas piping: Location. 154.910 Section 154.910 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY... Atmospheric Control in Cargo Containment Systems § 154.910 Inert gas piping: Location. Inert gas piping must...

  17. 46 CFR 154.908 - Inert gas generator: Location.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Inert gas generator: Location. 154.908 Section 154.908... Atmospheric Control in Cargo Containment Systems § 154.908 Inert gas generator: Location. (a) Except as allowed in paragraph (b) of this section, an inert gas generator must be located in the main machinery...

  18. PET image reconstruction with rotationally symmetric polygonal pixel grid based highly compressible system matrix

    International Nuclear Information System (INIS)

    Yu Yunhan; Xia Yan; Liu Yaqiang; Wang Shi; Ma Tianyu; Chen Jing; Hong Baoyu

    2013-01-01

    To achieve a maximum compression of system matrix in positron emission tomography (PET) image reconstruction, we proposed a polygonal image pixel division strategy in accordance with rotationally symmetric PET geometry. Geometrical definition and indexing rule for polygonal pixels were established. Image conversion from polygonal pixel structure to conventional rectangular pixel structure was implemented using a conversion matrix. A set of test images were analytically defined in polygonal pixel structure, converted to conventional rectangular pixel based images, and correctly displayed which verified the correctness of the image definition, conversion description and conversion of polygonal pixel structure. A compressed system matrix for PET image recon was generated by tap model and tested by forward-projecting three different distributions of radioactive sources to the sinogram domain and comparing them with theoretical predictions. On a practical small animal PET scanner, a compress ratio of 12.6:1 of the system matrix size was achieved with the polygonal pixel structure, comparing with the conventional rectangular pixel based tap-mode one. OS-EM iterative image reconstruction algorithms with the polygonal and conventional Cartesian pixel grid were developed. A hot rod phantom was detected and reconstructed based on these two grids with reasonable time cost. Image resolution of reconstructed images was both 1.35 mm. We conclude that it is feasible to reconstruct and display images in a polygonal image pixel structure based on a compressed system matrix in PET image reconstruction. (authors)

  19. Acellular dermal matrix based nipple reconstruction: A modified technique

    Directory of Open Access Journals (Sweden)

    Raghavan Vidya

    2017-09-01

    Full Text Available Nipple areolar reconstruction (NAR has evolved with the advancement in breast reconstruction and can improve self-esteem and, consequently, patient satisfaction. Although a variety of reconstruction techniques have been described in the literature varying from nipple sharing, local flaps to alloplastic and allograft augmentation, over time, loss of nipple projection remains a major problem. Acellular dermal matrices (ADM have revolutionised breast reconstruction more recently. We discuss the use of ADM to act as a base plate and strut to give support to the base and offer nipple bulk and projection in a primary procedure of NAR with a local clover shaped dermal flap in 5 breasts (4 patients. We used 5-point Likert scales (1 = highly unsatisfied, 5 = highly satisfied to assess patient satisfaction. Median age was 46 years (range: 38–55 years. Nipple projection of 8 mm, 7 mm, and 7 mms were achieved in the unilateral cases and 6 mm in the bilateral case over a median 18 month period. All patients reported at least a 4 on the Likert scale. We had no post-operative complications. It seems that nipple areolar reconstruction [NAR] using ADM can achieve nipple projection which is considered aesthetically pleasing for patients.

  20. Radar Target Detection Method of Aircraft Wake Vortices Based on Matrix Information Geometry

    Directory of Open Access Journals (Sweden)

    Liu Junkai

    2017-12-01

    Full Text Available The application of matrix information geometry to radar signal processing and target detection is a new and interesting subject. Wake vortices are Doppler-spread after Fourier transform. The traditional Moving Target Detection (MTD method cannot adequately accumulate returns power of the whole spectrum. Based on matrix information geometry, a matrix Constant False Alarm Rate (CFAR detection method is proposed to improve the detection performance of a weak wake target. In this method, covariance matrices of the observed data can be constructed into a matrix manifold; compared with CFAR detection, the geodesic distance between the covariance matrix in the detection cell and the mean of covariance matrices in the secondary cell is regarded as the detection statistics. Using simulated wake vortices, the return data in background noise and the iterative estimation performance of Riemannian mean are analyzed; the geodesic distance of covariance matrices of target return and noise with varying signal-noise rate is analyzed; and the detection performance of the matrix CFAR and the conventional MTD method is compared.

  1. Recognition and defect detection of dot-matrix text via variation-model based learning

    Science.gov (United States)

    Ohyama, Wataru; Suzuki, Koushi; Wakabayashi, Tetsushi

    2017-03-01

    An algorithm for recognition and defect detection of dot-matrix text printed on products is proposed. Extraction and recognition of dot-matrix text contains several difficulties, which are not involved in standard camera-based OCR, that the appearance of dot-matrix characters is corrupted and broken by illumination, complex texture in the background and other standard characters printed on product packages. We propose a dot-matrix text extraction and recognition method which does not require any user interaction. The method employs detected location of corner points and classification score. The result of evaluation experiment using 250 images shows that recall and precision of extraction are 78.60% and 76.03%, respectively. Recognition accuracy of correctly extracted characters is 94.43%. Detecting printing defect of dot-matrix text is also important in the production scene to avoid illegal productions. We also propose a detection method for printing defect of dot-matrix characters. The method constructs a feature vector of which elements are classification scores of each character class and employs support vector machine to classify four types of printing defect. The detection accuracy of the proposed method is 96.68 %.

  2. Impact of change of matrix crystallinity and polymorphism on ovalbumin release from lipid-based implants.

    Science.gov (United States)

    Duque, Luisa; Körber, Martin; Bodmeier, Roland

    2018-02-13

    The objectives of this study were to prepare lipid-based implants by hot melt extrusion (HME) for the prolonged release of ovalbumin (OVA), and to relate protein release to crystallinity and polymorphic changes of the lipid matrix. Two lipids, glycerol tristearate and hydrogenated palm oil, with different composition and degree of crystallinity were studied. Solid OVA was dispersed within the lipid matrixes, which preserved its stability during extrusion. This was partially attributed to a protective effect of the lipidic matrix. The incorporation of OVA decreased the mechanical strength of the implants prepared with the more crystalline matrix, glycerol tristearate, whereas it remained comparable for the hydrogenated palm oil because of stronger physical and non-covalent interactions between the protein and this lipid. This was also the reason for the faster release of OVA from the glycerol tristearate matrix when compared to the hydrogenated palm oil (8 vs. 28 weeks). Curing induced and increased crystallinity, and changes in the release rate, especially for the more crystalline matrix. In this case, both an increase and a decrease in release, were observed depending on the tempering condition. Curing at higher temperatures induced a melt-mediated crystallization and solid state transformation of the glycerol tristearate matrix and led to rearrangements of the inner structure with the formation of larger pores, which accelerated the release. In contrast, changes in the hydrogenated palm oil under the same curing conditions were less noticeable leading to a more robust formulation, because of less polymorphic changes over time. This study helps to understand the effect of lipid matrix composition and crystallinity degree on the performance of protein-loaded implants, and to establish criteria for the selection of a lipid carrier depending on the release profile desired. Copyright © 2018. Published by Elsevier B.V.

  3. Uranium and thorium based phosphate matrix: synthesis, characterizations and lixiviation

    International Nuclear Information System (INIS)

    Dacheux, N.

    1995-03-01

    In the framework of the search for a ceramic material usable in the radioactive waste storage, uranium and thorium phosphates have been investigated. Their experimental synthesis conditions have been entirely reviewed, they lead to the preparation of four new compounds: U(UO 2 )(PO 4 ) 2 , U 2 O(PO 4 ) 2 , UCIPO 4 , 4H 2 O, and Th 4 (PO 4 ) 4 P 2 O 7 . Experimental evidenced are advanced for non existent compounds such as: U 3 (PO 4 ) 4 , U 2 O 3 P 2 O 7 and Th 3 (PO 4 ) 4 . Characterization by several techniques (X-rays and neutron powder diffractions, UV-Visible and Infra-red spectroscopies, XPS,...) were performed. The ab initio structure determination of U(UO 2 )(PO 4 ) 2 has been achieved by X-rays and refined by neutron diffractions. Through its physico-chemical analysis, we found that this compound was a new mixed valence uranium phosphate in which U 4+ and UO 2 2+ ions are ordered in pairs along parallel chains according to a new type of arrangement. Reaction mechanism, starting from UCIPO 4 , 4H 2 O and based on redox processes of uranium in solid state was set up. From two main matrices U(UO 2 )(PO 4 ) 2 and Th 4 (PO 4 ) 4 P 2 O 7 , solid solutions were studied. They consist of replacement of U(IV) by Th(IV) and reversely. The leaching tests on pure, loaded and doped matrices were performed in terms of storage time, pH of solutions, and determined by the use of solids labelled with 230 U or by the measurement of uranyl concentration by Laser-Induced Time-Resolved Spectro-fluorimetry. Average concentration of uranium in the liquid phase is around 10 -4 M to 10 -6 M. Taking into account the very low solubilities of the studied phosphate ceramics, we estimated their chemical performances promising as an answer to the important nuclear waste problem, if we compare them to the glasses used at the present time. (author)

  4. Global exponential stability of neural networks with time-varying delay based on free-matrix-based integral inequality.

    Science.gov (United States)

    He, Yong; Ji, Meng-Di; Zhang, Chuan-Ke; Wu, Min

    2016-05-01

    This paper is concerned with global exponential stability problem for a class of neural networks with time-varying delays. Using a new proposed inequality called free-matrix-based integral inequality, a less conservative criterion is proposed, which is expressed by linear matrix inequalities. Two numerical examples are given to show the effectiveness and superiority of the obtained criterion. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. An optimization algorithm based on Eigen-matrix in interference alignment for relay

    Directory of Open Access Journals (Sweden)

    YUAN Lili

    2015-02-01

    Full Text Available For MIMO two-way relay network system,the data flow is asymmetric among users,bystudying the users with antenna distribution relationship between the relay,this paper propose optimization algorithm based on Eigen-matrix and the feasibility of the scheme.At first,this algorithm use rule of Eigen-matrix,it design optimization scheme of interference alignment for each user,at second,based on the distributed iterative algorithm to deduce the optimum matrix of interference suppression.In order to achieve the effect that in the purpose of each client to eliminate interference with other users.Through the simulation results show that the proposed algorithm than the traditional relay forced zero method on the system total rate has increased significantly.

  6. Sparse Non-negative Matrix Factorization (SNMF) based color unmixing for breast histopathological image analysis.

    Science.gov (United States)

    Xu, Jun; Xiang, Lei; Wang, Guanhao; Ganesan, Shridar; Feldman, Michael; Shih, Natalie Nc; Gilmore, Hannah; Madabhushi, Anant

    2015-12-01

    Color deconvolution has emerged as a popular method for color unmixing as a pre-processing step for image analysis of digital pathology images. One deficiency of this approach is that the stain matrix is pre-defined which requires specific knowledge of the data. This paper presents an unsupervised Sparse Non-negative Matrix Factorization (SNMF) based approach for color unmixing. We evaluate this approach for color unmixing of breast pathology images. Compared to Non-negative Matrix Factorization (NMF), the sparseness constraint imposed on coefficient matrix aims to use more meaningful representation of color components for separating stained colors. In this work SNMF is leveraged for decomposing pure stained color in both Immunohistochemistry (IHC) and Hematoxylin and Eosin (H&E) images. SNMF is compared with Principle Component Analysis (PCA), Independent Component Analysis (ICA), Color Deconvolution (CD), and Non-negative Matrix Factorization (NMF) based approaches. SNMF demonstrated improved performance in decomposing brown diaminobenzidine (DAB) component from 36 IHC images as well as accurately segmenting about 1400 nuclei and 500 lymphocytes from H & E images. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Robust Face Recognition via Multi-Scale Patch-Based Matrix Regression.

    Directory of Open Access Journals (Sweden)

    Guangwei Gao

    Full Text Available In many real-world applications such as smart card solutions, law enforcement, surveillance and access control, the limited training sample size is the most fundamental problem. By making use of the low-rank structural information of the reconstructed error image, the so-called nuclear norm-based matrix regression has been demonstrated to be effective for robust face recognition with continuous occlusions. However, the recognition performance of nuclear norm-based matrix regression degrades greatly in the face of the small sample size problem. An alternative solution to tackle this problem is performing matrix regression on each patch and then integrating the outputs from all patches. However, it is difficult to set an optimal patch size across different databases. To fully utilize the complementary information from different patch scales for the final decision, we propose a multi-scale patch-based matrix regression scheme based on which the ensemble of multi-scale outputs can be achieved optimally. Extensive experiments on benchmark face databases validate the effectiveness and robustness of our method, which outperforms several state-of-the-art patch-based face recognition algorithms.

  8. Dry boxes and inert atmosphere techniques

    International Nuclear Information System (INIS)

    Bartak, D.E.

    1987-01-01

    Practitioners need to conduct experiments with molten salts in an inert atmosphere owing to the chemical reactivity of these media. Most fused salt solvent systems show reactivity to water and/or oxygen, which results in significant chemical changes in the properties of these solvents. Although several studies on the nature of an oxygen/oxide electrode in this melt have been reported, the reactions have not been fully understood because of apparent water contamination in many cases. Nitrate melt systems are also hygroscopic; for example, the LiNO 3 -KNO 3 eutectic (177 0 C) absorbs water to at least 0.2% by weight. The result is that the electrochemistry of heavier, electropositive metal ions has been significantly altered. In addition, trace amounts of water have been shown to significantly affect the oxygen-oxide redox chemistry in NaNO 3 -KNO 3 melts (250 0 C). The haloaluminates, which include AlCl 3 -NaCl (175 0 C), as well as AlCl 3 -organic salt binaries are particularly sensitive to the presence of both oxygen and moisture. Oxygen is a strong oxidant in the fused hydroxide systems with formation of superoxide ion from either oxide or water. This chapter describes general, inert atmosphere techniques which can be used by the molten salt experimentalist. Because of the limitations of volatility, vacuum manipulations are not considered. Rather, the use of glove boxes, glove bags, and inert bench-top techniques are discussed. The areas covered are: glove box and bag equipment, operation and maintenance of glove boxes and glove bags, and common operations conducted inside glove boxes

  9. NARCOSIS AND EMULSION REVERSAL BY INERT GASES

    Science.gov (United States)

    Sears, Dewey F.; Fenn, Wallace O.

    1957-01-01

    Investigations of the effect of high pressures of Na (100 to 130 atmospheres) and of Ar (60 to 80 atmospheres) showed that these gases are effective in reversing the phases of an oil in water emulsion. Nitrous oxide did not cause reversal at pressures as high as 53 atmospheres nor did helium as high as 107 atmospheres. We found CO2 most effective in reversing the emulsions and attributed this to its chemical properties. It is suggested that these observations may help to explain the narcotic effects of inert gases. PMID:13416527

  10. High performance matrix inversion based on LU factorization for multicore architectures

    KAUST Repository

    Dongarra, Jack

    2011-01-01

    The goal of this paper is to present an efficient implementation of an explicit matrix inversion of general square matrices on multicore computer architecture. The inversion procedure is split into four steps: 1) computing the LU factorization, 2) inverting the upper triangular U factor, 3) solving a linear system, whose solution yields inverse of the original matrix and 4) applying backward column pivoting on the inverted matrix. Using a tile data layout, which represents the matrix in the system memory with an optimized cache-aware format, the computation of the four steps is decomposed into computational tasks. A directed acyclic graph is generated on the fly which represents the program data flow. Its nodes represent tasks and edges the data dependencies between them. Previous implementations of matrix inversions, available in the state-of-the-art numerical libraries, are suffer from unnecessary synchronization points, which are non-existent in our implementation in order to fully exploit the parallelism of the underlying hardware. Our algorithmic approach allows to remove these bottlenecks and to execute the tasks with loose synchronization. A runtime environment system called QUARK is necessary to dynamically schedule our numerical kernels on the available processing units. The reported results from our LU-based matrix inversion implementation significantly outperform the state-of-the-art numerical libraries such as LAPACK (5x), MKL (5x) and ScaLAPACK (2.5x) on a contemporary AMD platform with four sockets and the total of 48 cores for a matrix of size 24000. A power consumption analysis shows that our high performance implementation is also energy efficient and substantially consumes less power than its competitors. © 2011 ACM.

  11. Fisher Matrix-based Predictions for Measuring the z= 3.35 Binned ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy; Volume 38; Issue 1. Fisher Matrix-based Predictions for Measuring the z = 3.35 Binned 21-cm Power Spectrum using the Ooty Wide Field Array (OWFA). Anjan Kumar Sarkar Somnath Bharadwaj Sk. Saiyad Ali. Review Article Volume 38 Issue 1 March 2017 Article ID ...

  12. Wear behaviour of Zr-based in situ bulk metallic glass matrix ...

    Indian Academy of Sciences (India)

    Zr-based bulk metallic glass (BMG) and its in situ BMG matrix composites with diameter of 3 mm were fabricated by conventional .... with no evidence of any crystalline Bragg peaks, indicating that the as-cast sample is fully ..... Acknowledgements. Funding by education fund item of Liaoning Province under grant no.

  13. GoDec+: Fast and Robust Low-Rank Matrix Decomposition Based on Maximum Correntropy.

    Science.gov (United States)

    Guo, Kailing; Liu, Liu; Xu, Xiangmin; Xu, Dong; Tao, Dacheng

    2017-04-24

    GoDec is an efficient low-rank matrix decomposition algorithm. However, optimal performance depends on sparse errors and Gaussian noise. This paper aims to address the problem that a matrix is composed of a low-rank component and unknown corruptions. We introduce a robust local similarity measure called correntropy to describe the corruptions and, in doing so, obtain a more robust and faster low-rank decomposition algorithm: GoDec+. Based on half-quadratic optimization and greedy bilateral paradigm, we deliver a solution to the maximum correntropy criterion (MCC)-based low-rank decomposition problem. Experimental results show that GoDec+ is efficient and robust to different corruptions including Gaussian noise, Laplacian noise, salt & pepper noise, and occlusion on both synthetic and real vision data. We further apply GoDec+ to more general applications including classification and subspace clustering. For classification, we construct an ensemble subspace from the low-rank GoDec+ matrix and introduce an MCC-based classifier. For subspace clustering, we utilize GoDec+ values low-rank matrix for MCC-based self-expression and combine it with spectral clustering. Face recognition, motion segmentation, and face clustering experiments show that the proposed methods are effective and robust. In particular, we achieve the state-of-the-art performance on the Hopkins 155 data set and the first 10 subjects of extended Yale B for subspace clustering.

  14. Development of a Problem-Based Learning Matrix for Data Collection

    Science.gov (United States)

    Sipes, Shannon M.

    2017-01-01

    Few of the papers published in journals and conference proceedings on problem-based learning (PBL) are empirical studies, and most of these use self-report as the measure of PBL (Beddoes, Jesiek, & Borrego, 2010). The current study provides a theoretically derived matrix for coding and classifying PBL that was objectively applied to official…

  15. A Predictive-Control-Based Over-Modulation Method for Conventional Matrix Converters

    DEFF Research Database (Denmark)

    Zhang, Guanguan; Yang, Jian; Sun, Yao

    2018-01-01

    to further enhance the system performance promptly. This method has advantages like the maximum voltage transfer ratio can reach 0.987 in the experiments; the total harmonic distortion of the input and output current are reduced, and the losses in the matrix converter are decreased. Moreover, the specific......To increase the voltage transfer ratio of the matrix converter and improve the input/output current performance simultaneously, an over-modulation method based on predictive control is proposed in this paper, where the weighting factor is selected by an automatic adjusting mechanism, which is able...

  16. Cloud-Based DDoS HTTP Attack Detection Using Covariance Matrix Approach

    Directory of Open Access Journals (Sweden)

    Abdulaziz Aborujilah

    2017-01-01

    Full Text Available In this era of technology, cloud computing technology has become essential part of the IT services used the daily life. In this regard, website hosting services are gradually moving to the cloud. This adds new valued feature to the cloud-based websites and at the same time introduces new threats for such services. DDoS attack is one such serious threat. Covariance matrix approach is used in this article to detect such attacks. The results were encouraging, according to confusion matrix and ROC descriptors.

  17. Novel Direction Of Arrival Estimation Method Based on Coherent Accumulation Matrix Reconstruction

    Directory of Open Access Journals (Sweden)

    Li Lei

    2015-04-01

    Full Text Available Based on coherent accumulation matrix reconstruction, a novel Direction Of Arrival (DOA estimation decorrelation method of coherent signals is proposed using a small sample. First, the Signal to Noise Ratio (SNR is improved by performing coherent accumulation operation on an array of observed data. Then, according to the structure characteristics of the accumulated snapshot vector, the equivalent covariance matrix, whose rank is the same as the number of array elements, is constructed. The rank of this matrix is proved to be determined just by the number of incident signals, which realize the decorrelation of coherent signals. Compared with spatial smoothing method, the proposed method performs better by effectively avoiding aperture loss with high-resolution characteristics and low computational complexity. Simulation results demonstrate the efficiency of the proposed method.

  18. Image restoration via patch orientation-based low-rank matrix approximation and nonlocal means

    Science.gov (United States)

    Zhang, Di; He, Jiazhong; Du, Minghui

    2016-03-01

    Low-rank matrix approximation and nonlocal means (NLM) are two popular techniques for image restoration. Although the basic principle for applying these two techniques is the same, i.e., similar image patches are abundant in the image, previously published related algorithms use either low-rank matrix approximation or NLM because they manipulate the information of similar patches in different ways. We propose a method for image restoration by jointly using low-rank matrix approximation and NLM in a unified minimization framework. To improve the accuracy of determining similar patches, we also propose a patch similarity measurement based on curvelet transform. Extensive experiments on image deblurring and compressive sensing image recovery validate that the proposed method achieves better results than many state-of-the-art algorithms in terms of both quantitative measures and visual perception.

  19. A perturbation-based framework for link prediction via non-negative matrix factorization.

    Science.gov (United States)

    Wang, Wenjun; Cai, Fei; Jiao, Pengfei; Pan, Lin

    2016-12-15

    Many link prediction methods have been developed to infer unobserved links or predict latent links based on the observed network structure. However, due to network noises and irregular links in real network, the performances of existed methods are usually limited. Considering random noises and irregular links, we propose a perturbation-based framework based on Non-negative Matrix Factorization to predict missing links. We first automatically determine the suitable number of latent features, which is inner rank in NMF, by Colibri method. Then, we perturb training set of a network by perturbation sets many times and get a series of perturbed networks. Finally, the common basis matrix and coefficients matrix of these perturbed networks are obtained via NMF and form similarity matrix of the network for link prediction. Experimental results on fifteen real networks show that the proposed framework has competitive performances compared with state-of-the-art link prediction methods. Correlations between the performances of different methods and the statistics of networks show that those methods with good precisions have similar consistence.

  20. Matrix-based system reliability method and applications to bridge networks

    International Nuclear Information System (INIS)

    Kang, W.-H.; Song Junho; Gardoni, Paolo

    2008-01-01

    Using a matrix-based system reliability (MSR) method, one can estimate the probabilities of complex system events by simple matrix calculations. Unlike existing system reliability methods whose complexity depends highly on that of the system event, the MSR method describes any general system event in a simple matrix form and therefore provides a more convenient way of handling the system event and estimating its probability. Even in the case where one has incomplete information on the component probabilities and/or the statistical dependence thereof, the matrix-based framework enables us to estimate the narrowest bounds on the system failure probability by linear programming. This paper presents the MSR method and applies it to a transportation network consisting of bridge structures. The seismic failure probabilities of bridges are estimated by use of the predictive fragility curves developed by a Bayesian methodology based on experimental data and existing deterministic models of the seismic capacity and demand. Using the MSR method, the probability of disconnection between each city/county and a critical facility is estimated. The probability mass function of the number of failed bridges is computed as well. In order to quantify the relative importance of bridges, the MSR method is used to compute the conditional probabilities of bridge failures given that there is at least one city disconnected from the critical facility. The bounds on the probability of disconnection are also obtained for cases with incomplete information

  1. A Matrix-Free Posterior Ensemble Kalman Filter Implementation Based on a Modified Cholesky Decomposition

    Directory of Open Access Journals (Sweden)

    Elias D. Nino-Ruiz

    2017-07-01

    Full Text Available In this paper, a matrix-free posterior ensemble Kalman filter implementation based on a modified Cholesky decomposition is proposed. The method works as follows: the precision matrix of the background error distribution is estimated based on a modified Cholesky decomposition. The resulting estimator can be expressed in terms of Cholesky factors which can be updated based on a series of rank-one matrices in order to approximate the precision matrix of the analysis distribution. By using this matrix, the posterior ensemble can be built by either sampling from the posterior distribution or using synthetic observations. Furthermore, the computational effort of the proposed method is linear with regard to the model dimension and the number of observed components from the model domain. Experimental tests are performed making use of the Lorenz-96 model. The results reveal that, the accuracy of the proposed implementation in terms of root-mean-square-error is similar, and in some cases better, to that of a well-known ensemble Kalman filter (EnKF implementation: the local ensemble transform Kalman filter. In addition, the results are comparable to those obtained by the EnKF with large ensemble sizes.

  2. Image Retrieval Based on Multiview Constrained Nonnegative Matrix Factorization and Gaussian Mixture Model Spectral Clustering Method

    Directory of Open Access Journals (Sweden)

    Qunyi Xie

    2016-01-01

    Full Text Available Content-based image retrieval has recently become an important research topic and has been widely used for managing images from repertories. In this article, we address an efficient technique, called MNGS, which integrates multiview constrained nonnegative matrix factorization (NMF and Gaussian mixture model- (GMM- based spectral clustering for image retrieval. In the proposed methodology, the multiview NMF scheme provides competitive sparse representations of underlying images through decomposition of a similarity-preserving matrix that is formed by fusing multiple features from different visual aspects. In particular, the proposed method merges manifold constraints into the standard NMF objective function to impose an orthogonality constraint on the basis matrix and satisfy the structure preservation requirement of the coefficient matrix. To manipulate the clustering method on sparse representations, this paper has developed a GMM-based spectral clustering method in which the Gaussian components are regrouped in spectral space, which significantly improves the retrieval effectiveness. In this way, image retrieval of the whole database translates to a nearest-neighbour search in the cluster containing the query image. Simultaneously, this study investigates the proof of convergence of the objective function and the analysis of the computational complexity. Experimental results on three standard image datasets reveal the advantages that can be achieved with the proposed retrieval scheme.

  3. Assessment of Matrix Multiplication Learning with a Rule-Based Analytical Model--"A Bayesian Network Representation"

    Science.gov (United States)

    Zhang, Zhidong

    2016-01-01

    This study explored an alternative assessment procedure to examine learning trajectories of matrix multiplication. It took rule-based analytical and cognitive task analysis methods specifically to break down operation rules for a given matrix multiplication. Based on the analysis results, a hierarchical Bayesian network, an assessment model,…

  4. Inert carriers for column extraction chromatography

    International Nuclear Information System (INIS)

    Katykhin, G.S.

    1978-01-01

    Inert carriers used in column extraction chromatography are reviewed. Such carriers are devided into two large groups: hydrophilic carriers which possess high surface energy and are well wetted only with strongly polar liquids (kieselguhrs, silica gels, glasses, cellulose, Al 2 O 3 ) and water-repellent carriers which possess low surface energy and are well wetted with various organic solvents (polyethylene, polytetrafluorethylene polytrifluorochlorethylene). Properties of various carriers are presented: structure, chemical and radiation stability, adsorption properties, extracting agent capacity. The effect of structure and sizes of particles on the efficiency of chromatography columns is considered. Ways of immovable phase deposition on the carrier and the latter's regeneration. Peculiarities of column packing for preparative and continuous chromatography are discussed

  5. Seeded inert gas driven disk generator

    International Nuclear Information System (INIS)

    Joshi, N.K.; Venkatramani, N.; Rohatgi, V.K.

    1987-01-01

    This report outlines the present status of work being carried out in closed cycle MHD and disk generators. It gives the basic principles and discusses a proposal for setting up an experimental facility to study nonequilibrium plasmas using an inert gas driven disk generator. Disk geometry is a near ideal geometry for plasma studies since it has single or few pair electrodes combined with near perfect insulating walls. The proposed outlay of facility with components and subsystem is given. The facility may also be used to study the concept of fully ionized seed and to develop advanced diagnostic techniques. The absic equation describing the working parameters of such a system is also given in the Appendix. (author). 57 refs

  6. Inert gas atomization of chemical grade silicon

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, D.; Ferreira Neto, J.B.; Salgado, L.; Nogueira, P.F.; Poco, J.G.R. [Metallurgy Div. Cidade Univ., Inst. for Technological Research, Sao Paulo, SP (Brazil)

    2001-07-01

    The use of inert gas atomization to obtain chemical grade silicon particles was investigated. Both cooling rate and chemical composition are very important regarding a tailored microstructure, related with silicon performance during the synthesis of the silanos, an intermediary raw material in the silicone production. Previously refined silicon was used as raw material. Silicon with different aluminum contents were atomized and analyzed. The atomization temperature was set around 1520 C, and it was used a confined atomization nozzle. It was necessary to use a long atomization chamber to allow the cooling of the coarse silicon particles. After atomization, the powder was characterized and classified. The coarse fraction was milled. Two different particle size groups (different cooling rates) and the as atomized particles were investigated. The chemical behavior during the synthesis of the silanos was analyzed in a laboratory reactor. The relationship between cooling rate, aluminum content and silicon performance during the silanos synthesis is discussed. (orig.)

  7. Characterising shock propagation through inert beds

    Science.gov (United States)

    Edgeley, James; Braithwaite, Christopher

    2017-06-01

    Optical velocimetry methods have been used extensively to measure the detonation wave velocity in explosives. The reaction zone length can subsequently be inferred using one of several methods, most involving transmitting the shock into an acceptor component made of another material and observing the wave's attenuation. The ultimate aim of this investigation is to develop a method optimised for characterising the reaction zone in low density PETN. The initial procedure involves a shock imparted by a gas gun into an inert bed in otherwise similar conditions. The design of the acceptor component is varied, and in each case an appropriate calculation is done to determine the size and profile of the shock. Laser interferometry is used to take velocity measurements where necessary. The results are compared against the input shock from the gun to assess the suitability of the apparatus.

  8. Spatial and thematic assessment of object-based forest stand delineation using an OFA-matrix

    Science.gov (United States)

    Hernando, A.; Tiede, D.; Albrecht, F.; Lang, S.

    2012-10-01

    The delineation and classification of forest stands is a crucial aspect of forest management. Object-based image analysis (OBIA) can be used to produce detailed maps of forest stands from either orthophotos or very high resolution satellite imagery. However, measures are then required for evaluating and quantifying both the spatial and thematic accuracy of the OBIA output. In this paper we present an approach for delineating forest stands and a new Object Fate Analysis (OFA) matrix for accuracy assessment. A two-level object-based orthophoto analysis was first carried out to delineate stands on the Dehesa Boyal public land in central Spain (Avila Province). Two structural features were first created for use in class modelling, enabling good differentiation between stands: a relational tree cover cluster feature, and an arithmetic ratio shadow/tree feature. We then extended the OFA comparison approach with an OFA-matrix to enable concurrent validation of thematic and spatial accuracies. Its diagonal shows the proportion of spatial and thematic coincidence between a reference data and the corresponding classification. New parameters for Spatial Thematic Loyalty (STL), Spatial Thematic Loyalty Overall (STLOVERALL) and Maximal Interfering Object (MIO) are introduced to summarise the OFA-matrix accuracy assessment. A stands map generated by OBIA (classification data) was compared with a map of the same area produced from photo interpretation and field data (reference data). In our example the OFA-matrix results indicate good spatial and thematic accuracies (>65%) for all stand classes except for the shrub stands (31.8%), and a good STLOVERALL (69.8%). The OFA-matrix has therefore been shown to be a valid tool for OBIA accuracy assessment.

  9. Investigation of optical properties of anthocyanin doped into sol-gel based matrix

    Science.gov (United States)

    Hashim, Hasrina; Abdul Aziz, Nik Mohd Azmi Nik; Isnin, Aishah

    2012-06-01

    Anthocyanin dye was extracted from petal of Hibiscus rosasinensis (Bunga Raya) and doped into sol-gel based matrix to investigate an effect of pH change on its optical properties. Sol-gel matrix based on Vinyl triethoxysilene (VTES) as a precursor was prepared through Sol-gel process at pH 7. The sol was doped with 0.1% of Anthocyanin and the same amount of dye was also dissolved in ethanol as a comparative sample. Hydrochloric Acid, HCl and Tetramethylammonium Hydroxide, TMAH were used to change the pH value by adding them at various concentrations into each sample. The emission spectra and chemical structures of the samples were measured by Spectrofluorometer and Fourier Transform Infrared (FTIR) respectively. When excited at 410 nm, two emission peaks at about 492 and 574 nm were observed for Anthocyanin in acidic environment both in ethanol and VTES sol. In base environment however, only Anthocyanin dissolved in ethanol produced emission peak with a single peak at about 539 nm. The sensitivity of Anthocyanin dye toward pH changes in VTES open a possibility to use it as sensing element in which sol-gel based matrix are known to have higher mechanical strength and thermal stability.

  10. Hessian regularization based symmetric nonnegative matrix factorization for clustering gene expression and microbiome data.

    Science.gov (United States)

    Ma, Yuanyuan; Hu, Xiaohua; He, Tingting; Jiang, Xingpeng

    2016-12-01

    Nonnegative matrix factorization (NMF) has received considerable attention due to its interpretation of observed samples as combinations of different components, and has been successfully used as a clustering method. As an extension of NMF, Symmetric NMF (SNMF) inherits the advantages of NMF. Unlike NMF, however, SNMF takes a nonnegative similarity matrix as an input, and two lower rank nonnegative matrices (H, H T ) are computed as an output to approximate the original similarity matrix. Laplacian regularization has improved the clustering performance of NMF and SNMF. However, Laplacian regularization (LR), as a classic manifold regularization method, suffers some problems because of its weak extrapolating ability. In this paper, we propose a novel variant of SNMF, called Hessian regularization based symmetric nonnegative matrix factorization (HSNMF), for this purpose. In contrast to Laplacian regularization, Hessian regularization fits the data perfectly and extrapolates nicely to unseen data. We conduct extensive experiments on several datasets including text data, gene expression data and HMP (Human Microbiome Project) data. The results show that the proposed method outperforms other methods, which suggests the potential application of HSNMF in biological data clustering. Copyright © 2016. Published by Elsevier Inc.

  11. Influence of the inert and active ion bombardment on structure of the transition metal thin films

    CERN Document Server

    Blazhevich, S; Martynov, I; Neklyudov, I

    2002-01-01

    The results of the experimental research of the inert (He, Ne, Ar, Kr, Xe) and active (O, N) ion impact on the transition metal structure are presented. Thin high-purity (99.999 at.%) films of nickel, chrome and iron were used in the experiment. The bombardment was realized under room temperature at high vacuum (P<1x10 sup - sup 7 Pa) by a separated ion beam of 10-10 sup 3 keV. As a main result of the experiment, the full absence of crystal matrix changes was ascertained for all the transition metals irradiated by inert gas ions. The chemical nature of the crystal structure changes observed in transition metals being under active ion bombardment was found out too.

  12. Network synthesis and parameter optimization for vehicle suspension with inerter

    Directory of Open Access Journals (Sweden)

    Long Chen

    2016-12-01

    Full Text Available In order to design a comfortable-oriented vehicle suspension structure, the network synthesis method was utilized to transfer the problem into solving a timing robust control problem and determine the structure of “inerter–spring–damper” suspension. Bilinear Matrix Inequality was utilized to obtain the timing transfer function. Then, the transfer function of suspension system can be physically implemented by passive elements such as spring, damper, and inerter. By analyzing the sensitivity and quantum genetic algorithm, the optimized parameters of inerter–spring–damper suspension were determined. A quarter-car model was established. The performance of the inerter–spring–damper suspension was verified under random input. The simulation results manifested that the dynamic performance of the proposed suspension was enhanced in contrast with traditional suspension. The root mean square of vehicle body acceleration decreases by 18.9%. The inerter–spring–damper suspension can inhibit the vertical vibration within the frequency of 1–3 Hz effectively and enhance the performance of ride comfort significantly.

  13. A Hybrid Algorithm for Non-negative Matrix Factorization Based on Symmetric Information Divergence.

    Science.gov (United States)

    Devarajan, Karthik; Ebrahimi, Nader; Soofi, Ehsan

    2015-11-01

    The objective of this paper is to provide a hybrid algorithm for non-negative matrix factorization based on a symmetric version of Kullback-Leibler divergence, known as intrinsic information . The convergence of the proposed algorithm is shown for several members of the exponential family such as the Gaussian, Poisson, gamma and inverse Gaussian models. The speed of this algorithm is examined and its usefulness is illustrated through some applied problems.

  14. A Matrix Method Based on the Fibonacci Polynomials to the Generalized Pantograph Equations with Functional Arguments

    Directory of Open Access Journals (Sweden)

    Ayşe Betül Koç

    2014-01-01

    Full Text Available A pseudospectral method based on the Fibonacci operational matrix is proposed to solve generalized pantograph equations with linear functional arguments. By using this method, approximate solutions of the problems are easily obtained in form of the truncated Fibonacci series. Some illustrative examples are given to verify the efficiency and effectiveness of the proposed method. Then, the numerical results are compared with other methods.

  15. A current controlled matrix converter for wind energy conversion systems based on permanent magnet synchronous generator

    OpenAIRE

    Naggar H. Saad; Ahmed A. El-Sattar; Mohamed I. Marei

    2016-01-01

    The main challenges of wind energy conversion systems (WECS) are to maximize the energy capture from the wind and injecting reactive power during the fault. This paper presents a current controlled matrix converter to interface Permanent Magnet Synchronous Generators (PMSG) based WECS with the grid. To achieve fast dynamic response with reduced current ripples, a hysteresis current control is utilized. The proposed control system decouples the active and reactive components of the PMSG curren...

  16. A reverberation-ray matrix method for guided wave-based non-destructive evaluation.

    Science.gov (United States)

    Zhu, Kaige; Qing, Xinlin P; Liu, Bin

    2017-05-01

    The paper presents an application of the reverberation-ray matrix (RRM) method for guided wave-based non-destructive evaluation (NDE). An exact analytical model for elastic wave propagation in multilayered anisotropic composites is developed with the RRM method. Dispersion curves, namely phase and group velocities varying with frequencies, can be calculated based on the analytical model, which are critical to the guided wave-based NDE. In addition, the characteristics of the guided wave propagation along different directions in laminated composites with different anisotropic degrees are investigated. Finally, the results obtained from the model are verified by finite element simulations. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Nine-Phase Induction Motor Dynamic Model Based On 3x9 Transformation Matrix

    Directory of Open Access Journals (Sweden)

    Mauridhi Heri Purnomo

    2013-07-01

    Full Text Available A dynamic model of multi-phase induction motors in term qdn is used to simplify analysis and separate armature and field of the motor. However, to generate dynamic model qdn, square matrices are always applied to all the analysis and based on two reference frames and a circuit of magnetically coupled transformer. In order to gain the qdn dynamic model of the nine-phase induction motors in easy, simple, quick and consistent way, the analysis is done through the equivalent circuit T model until it obtains the equations in matrix form. The 3x9 transformation matrix qdn is substituted into the equation form abc so that the matrix equation of qdn is obtained. Then qdn equation results a similar qd equivalent circuit, which has different methods n that is, based the circuit of magnetically coupled transformer. Simulation results show that the two-bases circuit is magnetically coupled into the transformer model and has similar angular speed and torque response to the motor though the load changes.

  18. Link predication based on matrix factorization by fusion of multi class organizations of the network.

    Science.gov (United States)

    Jiao, Pengfei; Cai, Fei; Feng, Yiding; Wang, Wenjun

    2017-08-21

    Link predication aims at forecasting the latent or unobserved edges in the complex networks and has a wide range of applications in reality. Almost existing methods and models only take advantage of one class organization of the networks, which always lose important information hidden in other organizations of the network. In this paper, we propose a link predication framework which makes the best of the structure of networks in different level of organizations based on nonnegative matrix factorization, which is called NMF 3 here. We first map the observed network into another space by kernel functions, which could get the different order organizations. Then we combine the adjacency matrix of the network with one of other organizations, which makes us obtain the objective function of our framework for link predication based on the nonnegative matrix factorization. Third, we derive an iterative algorithm to optimize the objective function, which converges to a local optimum, and we propose a fast optimization strategy for large networks. Lastly, we test the proposed framework based on two kernel functions on a series of real world networks under different sizes of training set, and the experimental results show the feasibility, effectiveness, and competitiveness of the proposed framework.

  19. Laboratory evaluation of the effect of inert dust formulations on the poultry red mite, Dermanyssus gallinae

    DEFF Research Database (Denmark)

    Kilpinen, Ole; Steenberg, Tove

    In the EU-project SAFEHOUSE one objective is to develop alternative control methods against poultry red mites based on a combination of inert dusts and mite-pathogenic fungal isolates. Both components have some pathogenicity to the mites. However, the question is whether a combination of the two...... components might produce a synergistic effect as seen in other arthropods. As a first step, the effects of a range of inert dust formulations were evaluated in the laboratory at different doses and at different levels of air humidity. The results have shown major variations in the speed of kill but also...

  20. A Practical Method ‘Discussion using Matrix Diagram’ , ConnectingHuman Base-Liberal-and Engineering Base-Professional-

    Science.gov (United States)

    Shimada, Wataru

    In order to bring up talented people, it is a most important subject how to awake ‘Emotional Human Power’ , which is the origin of Autonomy and Creativity. A Practical Method ‘Discussion using Matrix Diagram’ developed for improving ‘Emotional Human Power’ including ‘Communication Skill’ , is confirmed to be useful for connecting Human Base-Liberal-and Engineering Base-Professional-.

  1. Method of producing hydrogen, and rendering a contaminated biomass inert

    Science.gov (United States)

    Bingham, Dennis N [Idaho Falls, ID; Klingler, Kerry M [Idaho Falls, ID; Wilding, Bruce M [Idaho Falls, ID

    2010-02-23

    A method for rendering a contaminated biomass inert includes providing a first composition, providing a second composition, reacting the first and second compositions together to form an alkaline hydroxide, providing a contaminated biomass feedstock and reacting the alkaline hydroxide with the contaminated biomass feedstock to render the contaminated biomass feedstock inert and further producing hydrogen gas, and a byproduct that includes the first composition.

  2. The implementation of matrix free Newton /Krylov methods based on a fixed point iteration

    International Nuclear Information System (INIS)

    Downar, Y.X.T.

    2005-01-01

    A generalized approach is presented for coupling subsystems with Matrix Free Newton /Krylov (MFNK) methods. A system of nonlinear equations is defined based on a Fixed Point Iteration (FPI) scheme which does not require the reformulation of the coupled subsystems into a larger system of equations. This makes it possible for each of the subsystems to retain their respective solvers for the individual field equations. The MFNK method is applied to the new nonlinear system related to the FPI in order to find the fixed point. Convergence of both the FPI and the MFNK were analyzed and the convergence of the MFNK was shown to be dominated by the residual of linearized system. The residuals for the solution of the Newton linear system with the Matrix Free Krylov method consist of two parts, the residual due to the iteration which can be easily monitored and controlled in the Krylov iteration, and the residual introduced by the finite difference approximation of the matrix fee method. An algorithm is proposed to estimate the optimal perturbation size for MFNK which is based on balance of the truncation error and the round off error introduced by the finite difference approximation. It is shown that even for the cases in which the corresponding FPI diverges, the MFNK can achieve at least local q-linear and even q-quadratic convergence for most problems. (authors)

  3. Nanobody-based enzyme immunoassay for ochratoxin A in cereal with high resistance to matrix interference.

    Science.gov (United States)

    Liu, Xing; Tang, Zongwen; Duan, Zhenhua; He, Zhenyun; Shu, Mei; Wang, Xianxian; Gee, Shirley J; Hammock, Bruce D; Xu, Yang

    2017-03-01

    A sensitive indirect competitive nanobody-based enzyme linked immunosorbent assay (Nb-ELISA) for ochratoxin A (OTA) with high resistance to cereal matrix interference was developed. Nanobodies against OTA (Nb15, Nb28, Nb32, Nb36) were expressed in E. coli cells and their thermal stabilities were compared with that of an OTA-specific monoclonal antibody 6H8. All nanobodies could still retain their antigen-binding activity after exposure to temperature 95°C for 5min or to 90°C for 75min. Nb28 that exhibited the highest sensitivity in ELISA was selected for further research. An indirect competitive ELISA based on Nb28 was developed for OTA, with an IC 50 of 0.64ng/mL and a linear range (IC 20 -IC 80 ) of 0.27-1.47ng/mL. Cereal samples were analyzed following a 2.5 fold dilution of sample extracts, showing the good resistance to matrix interference of the Nb-ELSIA. The recovery of spiked cereal samples (rice, oats, barley) ranged from 80% to 105% and the Nb-ELISA results of OTA content in naturally contamined samples were in good agreement with those determined by a commercial ELISA kit. The results indicated the reliablity of nanobody as a promising immunoassay reagent for detection of mycotoxins in food matrix and its potential in biosensor development. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Entangled-photons compressive ghost imaging based on spatial correlation of sensing matrix

    Science.gov (United States)

    Liu, Dawei; Li, Lifei; Geng, Yixing; Kang, Yan; Zhang, Tongyi; Zhao, Wei; Dong, Weibin; Shi, Kunlin

    2017-12-01

    Using the entangled photons generated by the spontaneous parametric down conversion as a light source, we demonstrate the first quantum ghost imaging system with a modified compressive sensing technique based on the spatial correlation of sensing matrix (SCCS). The ghost image is achieved at 16.27% sampling ratio of raster scanning and 0.65 photons/pixel at each measurement on average. Our results show that image quality and photon-utilization efficiency are remarkably enhanced in comparison with the traditional compressive imaging technique, due to the sensing matrix and noise-free measurement vector rebuilt by SCCS technique. It suggests the great potential of SCCS technique applied in quantum imaging and other quantum optics fields, such as quantum charactering and quantum state tomography to use the information loaded in each photon with high efficiency.

  5. Analysis of a wavelength selectable cascaded DFB laser based on the transfer matrix method

    International Nuclear Information System (INIS)

    Xie Hongyun; Chen Liang; Shen Pei; Sun Botao; Wang Renqing; Xiao Ying; You Yunxia; Zhang Wanrong

    2010-01-01

    A novel cascaded DFB laser, which consists of two serial gratings to provide selectable wavelengths, is presented and analyzed by the transfer matrix method. In this method, efficient facet reflectivity is derived from the transfer matrix built for each serial section and is then used to simulate the performance of the novel cascaded DFB laser through self-consistently solving the gain equation, the coupled wave equation and the current continuity equations. The simulations prove the feasibility of this kind of wavelength selectable laser and a corresponding designed device with two selectable wavelengths of 1.51 μm and 1.53 μm is realized by experiments on InP-based multiple quantum well structure. (semiconductor devices)

  6. Performances of continuous dryer with inert medium fluidized bed

    Directory of Open Access Journals (Sweden)

    Arsenijević Zorana Lj.

    2008-01-01

    Full Text Available A fluid bed dryer with inert particles represents a very attractive alternative to other drying technologies according to the main efficiency criteria, i.e. specific water evaporation rate, specific heat consumption and speci­fic air consumption. A high drying efficiency results from the large con­tact area and from the large temperature difference between the inlet and outlet air. A rapid mixing of the particles leads to nearly isothermal conditions throughout the bed. A fluid bed dryer with inert particles was used for drying of slurries. Experiments were performed in a cylindrical column 215 mm in diameter with glass spheres as inert particles. In this paper, results of drying experi­ments with slurries of Zineb fungicide, copper hydroxide, calcium carbo­nate and pure water used as the feed material are presented. In our fluidized bed we successfully dried a number of other materials such as: fungicides and pesticides (Ziram, Propineb, Mangozeb, copper oxy-chloride, copper oxy-sulphate, Bordeaux mixture, other inorganic compounds (calcium sulphate, cobalt carbonate, electrolytic copper, sodium chloride, and a complex compound (organo-bentonite. The effects of operating conditions on dryer throughput and product quality were investigated. Main performance criteria, i.e. specific water evaporation rate, specific heat consumption and specific air consumption, were quantified. Temperature profile along the bed was mapped, and nearly isothermal conditions were found due to thorough mixing of the particles. Analysis of drying and energy efficiencies as a function of inlet and outlet air temperature difference was performed for deeper insight in dryer behavior and for optimizing dryer design and operation from an energy point of view. A simple mathematical model based on an overall heat balance predicts the dryer performance quite well. The industrial prototype with fluid bed of 0.8 m in diameter and capacity 650 kg of evaporated moisture per

  7. Least Squares Based Iterative Algorithm for the Coupled Sylvester Matrix Equations

    Directory of Open Access Journals (Sweden)

    Hongcai Yin

    2014-01-01

    Full Text Available By analyzing the eigenvalues of the related matrices, the convergence analysis of the least squares based iteration is given for solving the coupled Sylvester equations AX+YB=C and DX+YE=F in this paper. The analysis shows that the optimal convergence factor of this iterative algorithm is 1. In addition, the proposed iterative algorithm can solve the generalized Sylvester equation AXB+CXD=F. The analysis demonstrates that if the matrix equation has a unique solution then the least squares based iterative solution converges to the exact solution for any initial values. A numerical example illustrates the effectiveness of the proposed algorithm.

  8. Subspace-Based Noise Reduction for Speech Signals via Diagonal and Triangular Matrix Decompositions

    DEFF Research Database (Denmark)

    Hansen, Per Christian; Jensen, Søren Holdt

    2007-01-01

    We survey the definitions and use of rank-revealing matrix decompositions in single-channel noise reduction algorithms for speech signals. Our algorithms are based on the rank-reduction paradigm and, in particular, signal subspace techniques. The focus is on practical working algorithms, using both...... diagonal (eigenvalue and singular value) decompositions and rank-revealing triangular decompositions (ULV, URV, VSV, ULLV and ULLIV). In addition we show how the subspace-based algorithms can be evaluated and compared by means of simple FIR filter interpretations. The algorithms are illustrated...... with working Matlab code and applications in speech processing....

  9. Subspace-Based Noise Reduction for Speech Signals via Diagonal and Triangular Matrix Decompositions

    DEFF Research Database (Denmark)

    Hansen, Per Christian; Jensen, Søren Holdt

    We survey the definitions and use of rank-revealing matrix decompositions in single-channel noise reduction algorithms for speech signals. Our algorithms are based on the rank-reduction paradigm and, in particular, signal subspace techniques. The focus is on practical working algorithms, using both...... diagonal (eigenvalue and singular value) decompositions and rank-revealing triangular decompositions (ULV, URV, VSV, ULLV and ULLIV). In addition we show how the subspace-based algorithms can be evaluated and compared by means of simple FIR filter interpretations. The algorithms are illustrated...... with working Matlab code and applications in speech processing....

  10. A parton shower based on factorization of the quantum density matrix

    International Nuclear Information System (INIS)

    Nagy, Zoltan; Soper, Davison E.

    2014-01-01

    We present rst results from a new parton shower event generator, DEDUCTOR. Anticipating a need for an improved treatment of parton color and spin, the structure of the generator is based on the quantum density matrix in color and spin space. So far, DEDUCTOR implements only a standard spin-averaged treatment of spin in parton splittings. Although DEDUCTOR implements an improved treatment of color, in this paper we present results in the standard leading color approximation so that we can compare to the generator PYTHIA. The algorithms used incorporate a virtuality based shower ordering parameter and massive initial state bottom and charm quarks.

  11. SENSITIVITY TEMPERATURE DEPENDENCE RESEARCH OF TV-CAMERAS BASED ON SILICON MATRIXES

    Directory of Open Access Journals (Sweden)

    Alexey N. Starchenko

    2017-07-01

    Full Text Available Subject of Research. The research is dedicated to the analysis of sensitivity change patterns of the cameras based on silicon CMOS-matrixes in various ambient temperatures. This information is necessary for the correct camera application for photometric measurements in-situ. The paper deals with studies of sensitivity variations of two digital cameras with different silicon CMOS matrixes in visible and near IR regions of the spectrum at temperature change. Method. Due to practical restrictions the temperature changes were recorded in separate spectral intervals important for practical use of the cameras. The experiments were carried out with the use of a climatic chamber, providing change and keeping the temperature range from minus 40 to plus 50 °C at a pitch of 10 о С. Two cameras were chosen for research: VAC-135-IP with OmniVision OV9121 matrix and VAC-248-IP with OnSemiconductor VITA2000 matrix. The two tested devices were placed in a climatic chamber at the same time and illuminated by one radiation source with a color temperature about 3000 K in order to eliminate a number of methodological errors. Main Results. The temperature dependence of the signals was shown to be linear and the matrixes sensitivities were determined. The results obtained are consistent with theoretical views, in general. The coefficients of thermal sensitivity were computed by these dependencies. It is shown that the greatest affect of temperature on the sensitivity occurs in the area (0.7–1.1 mkm. Temperature coefficients of sensitivity increase with the downward radiation wavelength increase. The experiments carried out have shown that it is necessary to take into account the changes in temperature sensitivity of silicon matrixes in the red and near in IR regions of the spectrum. The effect reveals itself in a clearly negative way in cameras with an amplitude resolution of 10-12 bits used for aerospace and space spectrozonal photography. Practical Relevance

  12. Mn nanoparticles produced by inert gas condensation

    International Nuclear Information System (INIS)

    Ward, M B; Brydson, R; Cochrane, R F

    2006-01-01

    The results from experiments using the inert gas condensation method to produce nanoparticles of manganese are presented. Structural and compositional data have been collected through electron diffraction, EDX (energy dispersive X-ray) and EELS (electron energy loss spectroscopy). Both Mn 3 O 4 and pure Mn particles have been produced. Moisture in untreated helium gas causes the particles to oxidize, whereas running the helium through a liquid nitrogen trap removes the moisture and produces β-Mn particles in a metastable state. The particle sizes and the size distribution have been determined. Particle sizes range from 2nm to above 100 nm, however the majority of particles lie in the range below 20 nm with a modal particle size of 6 nm. As well as the modal particle size of 6 nm, there is another peak in the frequency curve at 16 nm that represents another group particles that lie in the range 12 to 20 nm. The smaller particles are single crystals, but the larger particles appear to have a dense region around their edge with a less dense centre. Determination of their exact nature is ongoing

  13. Additive Manufacturing of Silicon Carbide-Based Ceramic Matrix Composites: Technical Challenges and Opportunities

    Science.gov (United States)

    Singh, Mrityunjay; Halbig, Michael C.; Grady, Joseph E.

    2016-01-01

    Advanced SiC-based ceramic matrix composites offer significant contributions toward reducing fuel burn and emissions by enabling high overall pressure ratio (OPR) of gas turbine engines and reducing or eliminating cooling air in the hot-section components, such as shrouds, combustor liners, vanes, and blades. Additive manufacturing (AM), which allows high value, custom designed parts layer by layer, has been demonstrated for metals and polymer matrix composites. However, there has been limited activity on additive manufacturing of ceramic matrix composites (CMCs). In this presentation, laminated object manufacturing (LOM), binder jet process, and 3-D printing approaches for developing ceramic composite materials are presented. For the laminated object manufacturing (LOM), fiber prepreg laminates were cut into shape with a laser and stacked to form the desired part followed by high temperature heat treatments. For the binder jet, processing optimization was pursued through silicon carbide powder blending, infiltration with and without SiC nano powder loading, and integration of fibers into the powder bed. Scanning electron microscopy was conducted along with XRD, TGA, and mechanical testing. Various technical challenges and opportunities for additive manufacturing of ceramics and CMCs will be presented.

  14. A Low Complexity Subspace-Based DOA Estimation Algorithm with Uniform Linear Array Correlation Matrix Subsampling

    Directory of Open Access Journals (Sweden)

    Do-Sik Yoo

    2015-01-01

    Full Text Available We propose a low complexity subspace-based direction-of-arrival (DOA estimation algorithm employing a direct signal space construction method (DSPCM by subsampling the autocorrelation matrix of a uniform linear array (ULA. Three major contributions of this paper are as follows. First of all, we introduce the method of autocorrelation matrix subsampling which enables us to employ a low complexity algorithm based on a ULA without computationally complex eigenvalue decomposition or singular-value decomposition. Secondly, we introduce a signal vector separation method to improve the distinguishability among signal vectors, which can greatly improve the performance, particularly, in low signal-to-noise ratio (SNR regime. Thirdly, we provide a root finding (RF method in addition to a spectral search (SS method as the angle finding scheme. Through simulations, we illustrate that the performance of the proposed scheme is reasonably close to computationally much more expensive MUSIC- (MUltiple SIgnal Classification- based algorithms. Finally, we illustrate that the computational complexity of the proposed scheme is reduced, in comparison with those of MUSIC-based schemes, by a factor of O(N2/K, where K is the number of sources and N is the number of antenna elements.

  15. Prepare and characterization of nanocomposite - mixed matrix membranes based on polycarbonate

    International Nuclear Information System (INIS)

    Paranhos, Caio M.; Pessan, Luiz A.; Gomes, Ana C. de O.

    2009-01-01

    Mixed matrix membranes based on polycarbonate with different content of sepiolite were prepared by casting. The obtained membranes were characterized by wide-angle X-ray diffraction, thermal analysis, optical transparency and permeation to oxygen. The presence of sepiolite leads to the formation of a polymer-clay interface. The presence of the interface causes the increase in O 2 permeation. Increasing content of sepiolite results in aggregates of sepiolite, which forms preferential channels to the O 2 molecules. This fact is directly related to the strong increasing observed in O 2 permeability. (author)

  16. Renewable energy selection Matrix based on multi-attribute analysis for fish preservation

    International Nuclear Information System (INIS)

    Vega-Clavijo, Lili Tatiana; Prías-Caicedo, Omar Fredy; Sierra-Vargas, Fabio Emiro

    2016-01-01

    The article presents the application of the methodology of multi attribute utility theory validated by a matrix system established by researchers, to identify the best alternative of energy supply to 10 kwe in the generation of ice for preservation of fish in coastal and rural areas of the Chocó. The comparison between the potentials of different renewable energy sources and diesel, natural gas and propane fuels took place, based on economic, technological, environmental and social criteria, being validated by experts and the community on field work. It was concluded that the best alternative is diesel followed by biomass. (author)

  17. Bioactive and inert dental glass-ceramics.

    Science.gov (United States)

    Montazerian, Maziar; Zanotto, Edgar Dutra

    2017-02-01

    The global market for dental materials is predicted to exceed 10 billion dollars by 2020. The main drivers for this growth are easing the workflow of dentists and increasing the comfort of patients. Therefore, remarkable research projects have been conducted and are currently underway to develop improved or new dental materials with enhanced properties or that can be processed using advanced technologies, such as CAD/CAM or 3D printing. Among these materials, zirconia, glass or polymer-infiltrated ceramics, and glass-ceramics (GCs) are of great importance. Dental glass-ceramics are highly attractive because they are easy to process and have outstanding esthetics, translucency, low thermal conductivity, high strength, chemical durability, biocompatibility, wear resistance, and hardness similar to that of natural teeth, and, in certain cases, these materials are bioactive. In this review article, we divide dental GCs into the following two groups: restorative and bioactive. Most restorative dental glass-ceramics (RDGCs) are inert and biocompatible and are used in the restoration and reconstruction of teeth. Bioactive dental glass-ceramics (BDGCs) display bone-bonding ability and stimulate positive biological reactions at the material/tissue interface. BDGCs are suggested for dentin hypersensitivity treatment, implant coating, bone regeneration and periodontal therapy. Throughout this paper, we elaborate on the history, processing, properties and applications of RDGCs and BDGCs. We also report on selected papers that address promising types of dental glass-ceramics. Finally, we include trends and guidance on relevant open issues and research possibilities. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 619-639, 2017. © 2016 Wiley Periodicals, Inc.

  18. A Novel Silicon-based Wideband RF Nano Switch Matrix Cell and the Fabrication of RF Nano Switch Structures

    Directory of Open Access Journals (Sweden)

    Yi Xiu YANG

    2011-12-01

    Full Text Available This paper presents the concept of RF nano switch matrix cell and the fabrication of RF nano switch. The nano switch matrix cell can be implemented into complex switch matrix for signal routing. RF nano switch is the decision unit for the matrix cell; in this research, it is fabricated on a tri-layer high-resistivity-silicon substrate using surface micromachining approach. Electron beam lithography is introduced to define the pattern and IC compatible deposition process is used to construct the metal layers. Silicon-based nano switch fabricated by IC compatible process can lead to a high potential of system integration to perform a cost effective system-on-a-chip solution. In this paper, simulation results of the designed matrix cell are presented; followed by the details of the nano structure fabrication and fabrication challenges optimizations; finally, measurements of the fabricated nano structure along with analytical discussions are also discussed.

  19. [The design and experiment of complementary S coding matrix based on digital micromirror spectrometer].

    Science.gov (United States)

    Zhang, Zhi-Hai; Gao, Ling-Xiao; Guo, Yuan-Jun; Wang, Wei; Mo, Xiang-Xia

    2012-12-01

    The template selection is essential in the application of digital micromirror spectrometer. The best theoretical coding H-matrix is not widely used due to acyclic, complex coding and difficult achievement. The noise ratio of best practical S-matrix for improvement is slightly inferior to matrix H. So we designed a new type complementary S-matrix. Through studying its noise improvement theory, the algorithm is proved to have the advantages of both H-matrix and S-matrix. The experiments proved that the SNR can be increased 2.05 times than S-template.

  20. A flexible matrix-based human exposure assessment framework suitable for LCA and CAA

    DEFF Research Database (Denmark)

    Jolliet, Olivier; Ernstoff, Alexi; Huang, Lei

    2016-01-01

    use or exchange between near-and far-field compartments until sub -fractions reach humans via inhalation, ingestion or dermal uptake. Currently, however, multimedia exposure models mainly focus on far-field exposure pathways. Metrics and modeling approaches used in far-field, emission-based models...... are not applicable to all types of near-field chemical releases from consumer products, e.g. direct dermal application. A consistent near-and far-field framework is needed for life cycle assessment (LCA) and chemical alternative assessment (CAA) to inform mitigation of human exposure to harmful chemicals. To close...... the current research gaps, we (i) define a near-and far-field matrix-based exposure pathways framework that builds on a quantitative metric based on chemical mass in products, (ii) rovide input data for the framework, e.g. chemical concentrations in products linked to functional use categories, and (iii...

  1. A suppository-base-matrix tablet for time-dependent colon-specific delivery system

    Directory of Open Access Journals (Sweden)

    Meijuan Zou

    2014-09-01

    Full Text Available Our research has focused on the main design features and release performances of time-dependent colon-specific (TDCS delivery tablets, which relies on the relative constancy that is observed in the small intestinal transit time of dosage forms. But inflammatory bowel disease(IBD)can affect the transit time, and usually results in watery stool. Compared to the TDCS and wax-matrix TDCS tablet, a promising time-dependent colon-specific delivery system was investigated. In our study, a suppository-base-matrix coated tablet was evaluated. Water soluble suppository-base helps the expansion of tablet, facilitates uniform film dissolution and achives high osmotic pressure. Combining the expansion of carboxymethyl starch sodium (CMS-Na and the moisture absorption of NaCl, the coated TDCS tablet obtained a burst and targeted drug delivery system. A very good correlation between in vitro drug release and in vivo outcome was observed. This TDCS coated tablet provides a promising strategy to control drug release to the desired lower gastrointestinal region.

  2. A modelling of AC voltage stabilizer based on a hybrid transformer with matrix converter

    Directory of Open Access Journals (Sweden)

    Szcześniak Paweł

    2017-06-01

    Full Text Available This article presents a study of an AC voltage stabilizer based on a three-phase hybrid transformer combined with a matrix converter. The proposed solution is used to control AC voltage amplitude and phase shift. By adjustment of these voltage parameters we can reduce the effects of overvoltage, voltage dips or lamp flicker. Such negative phenomena are very significant, particularly from the perspective of the final consumer and sensitive loads connected to the power network. Often the voltage in the power system can be adjusted using a mechanical or thyristor controlled regulator, which in a stepwise manner switches the taps of the electromagnetic transformer. The method for obtaining continuous control of the voltage magnitude and phase shift with the use of a conventional transformer with two output windings and a matrix converter is presented in this paper. The operating principles, mathematical model and properties of the proposed voltage stabilizers are discussed in this paper. The main part of the article will be devoted to the mathematical model which is based on an averaged equation. Computer simulation results are presented and compared with the results of a mathematical study.

  3. Twinning-induced plasticity (TWIP) and work hardening in Ti-based metallic glass matrix composites.

    Science.gov (United States)

    Fan, J; Qiao, J W; Wang, Z H; Rao, W; Kang, G Z

    2017-05-12

    The present study demonstrates that Ti-based metallic glass matrix composites (MGMCs) with a normal composition of Ti 43 Zr 32 Ni 6 Ta 5 Be 14 containing ductile dendrites dispersed in the glass matrix has been developed, and deformation mechanisms about the tensile property have been investigated by focusing on twinning-induced plasticity (TWIP) effect. The Ti-based MGMC has excellent tensile properties and pronounced tensile work-hardening capacity, with a yield strength of 1100 MPa and homogeneous elongation of 4%. The distinguished strain hardening is ascribed to the formation of deformation twinning within the dendrites. Twinning generated in the dendrites works as an obstacle for the rapid propagation of shear bands, and then, the localized necking is avoided, which ensures the ductility of such kinds of composites. Besides, a finite-element model (FEM) has been established to explain the TWIP effect which brings out a work-hardening behavior in the present MGMC instead of a localized strain concentration. According to the plasticity theory of traditional crystal materials and some new alloys, TWIP effect is mainly controlled by stacking fault energy (SFE), which has been analyzed intensively in the present MGMC.

  4. Cellular morphology of organic-inorganic hybrid foams based on alkali alumino-silicate matrix

    Science.gov (United States)

    Verdolotti, Letizia; Liguori, Barbara; Capasso, Ilaria; Caputo, Domenico; Lavorgna, Marino; Iannace, Salvatore

    2014-05-01

    Organic-inorganic hybrid foams based on an alkali alumino-silicate matrix were prepared by using different foaming methods. Initially, the synthesis of an inorganic matrix by using aluminosilicate particles, activated through a sodium silicate solution, was performed at room temperature. Subsequently the viscous paste was foamed by using three different methods. In the first method, gaseous hydrogen produced by the oxidization of Si powder in an alkaline media, was used as blowing agent to generate gas bubbles in the paste. In the second method, the porous structure was generated by mixing the paste with a "meringue" type of foam previously prepared by whipping, under vigorous stirring, a water solution containing vegetal proteins as surfactants. In the third method, a combination of these two methods was employed. The foamed systems were consolidated for 24 hours at 40°C and then characterized by FTIR, X-Ray diffraction, scanning electron microscopy (SEM) and compression tests. Low density foams (˜500 Kg/m3) with good cellular structure and mechanical properties were obtained by combining the "meringue" approach with the use of the chemical blowing agent based on Si.

  5. An Analytical Model of Thermal Conductivity for Carbon/Carbon Composites with Pitch-Based Matrix

    Directory of Open Access Journals (Sweden)

    Zhi-Hai Feng

    2015-01-01

    Full Text Available The carbon/carbon (C/C composites are composed of carbon fibers, carbon matrix, and pores and cracks, which have been successfully used in various aerospace applications. In this paper, nanoscale submodel is proposed to describe the thermal conductivity of the matrix based on its microscopic structure, and then the submodel is incorporated into a microscale model to analytically predict the equivalent thermal conductivities of the composites by equivalent circuit approach. The results predicted by the present model agree well with those from the experimental measurements. Based on the model, the effects of the composite porosity as well as the thickness and porosity of the interface phase on the thermal performance of five composites are studied. It is found that the thermal conductivities show decreasing trends in responding to an increase in each of the three parameters. The composite porosity has a significant effect on the thermal conductivities both parallel and transverse to the fiber axis, while the thickness and the porosity of the interface phase remarkably affect the thermal conductivity only transverse to the fiber axis.

  6. Relationships among ventilation-perfusion distribution, multiple inert gas methodology and metabolic blood-gas tensions.

    Science.gov (United States)

    Lee, A S; Patterson, R W; Kaufman, R D

    1987-12-01

    The retention equations upon which the Multiple Inert Gas Method is based are derived from basic principles using elementary algebra. It is shown that widely disparate distributions produce indistinguishable sets of retentions. The limits of resolution of perfused compartments in the VA/Q distribution obtainable by the use of the multiple inert gas method are explored mathematically, and determined to be at most shunt and two alveolar compartments ("tripartite" distribution). Every continuous distribution studied produced retentions indistinguishable from those of its unique "matching" tripartite distribution. When a distribution is minimally specified, it is unique. Any additional specification (increased resolution--more compartments) of the distribution results in the existence of an infinitude of possible distributions characterized by indistinguishable sets of retention values. No further increase in resolution results from the use of more tracers. When sets of retention values were extracted from published multiple inert gas method continuous distributions, and compared with the published "measured" retention sets, substantial differences were found. This illustrates the potential errors incurred in the practical, in vivo application of the multiple inert gas method. In preliminary studies, the tripartite distribution could be determined with at least comparable accuracy by blood-gas (oxygen, carbon dioxide) measurements.

  7. Fog inerting criteria for hydrogen/air mixtures

    International Nuclear Information System (INIS)

    Tsai, S.S.; Liparulo, N.J.

    1982-01-01

    A distributed ignition system has been proposed to ignite hydrogen at low concentration in the ice condenser containment during severe accidents. The post-accident containment atmosphere could be misty due to fog generation from the break flow and condensation in the ice bed. Thus it is important to establish a fog inerting criterion for effective performance of the ignition system. This paper presents such a criterion that specifies the necessary fogging conditions, i.e., fog concentration and drop size, for inerting a hydrogen/air mixture. The criterion shows that the minimum fog inerting concentration varies with the square of the volume mean fog drop size. The present fog inerting criterion is shown to be in general agreement with the Factory Mutual test data

  8. effects of metal inert gas welding parameters on some mechanical ...

    African Journals Online (AJOL)

    EFFECTS OF METAL INERT GAS WELDING PARAMETERS ON SOME MECHANICAL PROPERTIES OF AUSTENITIC STAINLESS STEEL IN ACIDIC ... Design Expert Software, Scanning Electron Microscopy (SEM), Rockwell Hardness Test, Monsanto Tensometer and Izod Impact Test were used to determine the ...

  9. Recent study of nanomaterials prepared by inert gas condensation ...

    Indian Academy of Sciences (India)

    Ultra high vacuum chamber; inert gas condensation technique; nanocrystalline materials; lead fluoride; Mn2+-doped lead fluoride; indium tin oxide; zinc oxide; tin oxide; copper oxide; PMN-PT; high resolution transmission electron microscopy; nuclear magnetic resonance; electron paramagnetic resonance.

  10. TIG (Tungsten Inert Gas) welding; Le soudage TIG

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2010-09-15

    After having recalled the Tungsten Inert Gas process principle and the different alternative TIG processes, the author explains the advantages and limits of this process. The applications and recent developments are given. (O.M.)

  11. Evaluating changes in matrix based, recovery-adjusted concentrations in paired data for pesticides in groundwater

    Science.gov (United States)

    Zimmerman, Tammy M.; Breen, Kevin J.

    2012-01-01

    Pesticide concentration data for waters from selected carbonate-rock aquifers in agricultural areas of Pennsylvania were collected in 1993–2009 for occurrence and distribution assessments. A set of 30 wells was visited once in 1993–1995 and again in 2008–2009 to assess concentration changes. The data include censored matched pairs (nondetections of a compound in one or both samples of a pair). A potentially improved approach for assessing concentration changes is presented where (i) concentrations are adjusted with models of matrix-spike recovery and (ii) area-wide temporal change is tested by use of the paired Prentice-Wilcoxon (PPW) statistical test. The PPW results for atrazine, simazine, metolachlor, prometon, and an atrazine degradate, deethylatrazine (DEA), are compared using recovery-adjusted and unadjusted concentrations. Results for adjusted compared with unadjusted concentrations in 2008–2009 compared with 1993–1995 were similar for atrazine and simazine (significant decrease; 95% confidence level) and metolachlor (no change) but differed for DEA (adjusted, decrease; unadjusted, increase) and prometon (adjusted, decrease; unadjusted, no change). The PPW results were different on recovery-adjusted compared with unadjusted concentrations. Not accounting for variability in recovery can mask a true change, misidentify a change when no true change exists, or assign a direction opposite of the true change in concentration that resulted from matrix influences on extraction and laboratory method performance. However, matrix-based models of recovery derived from a laboratory performance dataset from multiple studies for national assessment, as used herein, rather than time- and study-specific recoveries may introduce uncertainty in recovery adjustments for individual samples that should be considered in assessing change.

  12. Stochastic-Strength-Based Damage Simulation of Ceramic Matrix Composite Laminates

    Science.gov (United States)

    Nemeth, Noel N.; Mital, Subodh K.; Murthy, Pappu L. N.; Bednarcyk, Brett A.; Pineda, Evan J.; Bhatt, Ramakrishna T.; Arnold, Steven M.

    2016-01-01

    The Finite Element Analysis-Micromechanics Analysis Code/Ceramics Analysis and Reliability Evaluation of Structures (FEAMAC/CARES) program was used to characterize and predict the progressive damage response of silicon-carbide-fiber-reinforced reaction-bonded silicon nitride matrix (SiC/RBSN) composite laminate tensile specimens. Studied were unidirectional laminates [0] (sub 8), [10] (sub 8), [45] (sub 8), and [90] (sub 8); cross-ply laminates [0 (sub 2) divided by 90 (sub 2),]s; angled-ply laminates [plus 45 (sub 2) divided by -45 (sub 2), ]s; doubled-edge-notched [0] (sub 8), laminates; and central-hole laminates. Results correlated well with the experimental data. This work was performed as a validation and benchmarking exercise of the FEAMAC/CARES program. FEAMAC/CARES simulates stochastic-based discrete-event progressive damage of ceramic matrix composite and polymer matrix composite material structures. It couples three software programs: (1) the Micromechanics Analysis Code with Generalized Method of Cells (MAC/GMC), (2) the Ceramics Analysis and Reliability Evaluation of Structures Life Prediction Program (CARES/Life), and (3) the Abaqus finite element analysis program. MAC/GMC contributes multiscale modeling capabilities and micromechanics relations to determine stresses and deformations at the microscale of the composite material repeating-unit-cell (RUC). CARES/Life contributes statistical multiaxial failure criteria that can be applied to the individual brittle-material constituents of the RUC, and Abaqus is used to model the overall composite structure. For each FEAMAC/CARES simulation trial, the stochastic nature of brittle material strength results in random, discrete damage events that incrementally progress until ultimate structural failure.

  13. Comparison of inert supports in laser desorption/ionization mass spectrometry of peptides: pencil lead, porous silica gel, DIOS-chip and NALDI target.

    Science.gov (United States)

    Shenar, Nawar; Cantel, Sonia; Martinez, Jean; Enjalbal, Christine

    2009-08-01

    In the search for alternative inert surfaces replacing silicon chips in Desorption/Ionization On porous Silicon (DIOS)-like mass spectrometry analyses, nanostructured silicon-based NALDI chips were evaluated in Laser Desorption/Ionization (LDI) of peptides. Comparisons were made using commercially available DIOS chips (MassPREP-DIOS-target), amorphous carbon powder from lead pencil and porous silica gel used for chromatographic purposes as reference supports. A set of synthetic model peptides presenting variable amino acid sequences of various lengths was analyzed under all conditions. The LDI responses of the four 'matrix-free' techniques were compared, especially in terms of peptide detection sensitivity and overall experiment robustness. Copyright (c) 2009 John Wiley & Sons, Ltd.

  14. Extracellular matrix elasticity and topography: material-based cues that affect cell function via conserved mechanisms

    Science.gov (United States)

    Janson, Isaac A.; Putnam, Andrew J.

    2014-01-01

    Chemical, mechanical, and topographic extracellular matrix (ECM) cues have been extensively studied for their influence on cell behavior. These ECM cues alter cell adhesion, cell shape, and cell migration, and activate signal transduction pathways to influence gene expression, proliferation, and differentiation. ECM elasticity and topography, in particular, have emerged as material properties of intense focus based on strong evidence these physical cue can partially dictate stem cell differentiation. Cells generate forces to pull on their adhesive contacts, and these tractional forces appear to be a common element of cells’ responses to both elasticity and topography. This review focuses on recently published work that links ECM topography and mechanics and their influence on differentiation and other cell behaviors, We also highlight signaling pathways typically implicated in mechanotransduction that are (or may be) shared by cells subjected to topographic cues. Finally, we conclude with a brief discussion of the potential implications of these commonalities for cell based therapies and biomaterial design. PMID:24910444

  15. Application of Transfer Matrix Approach to Modeling and Decentralized Control of Lattice-Based Structures

    Science.gov (United States)

    Cramer, Nick; Swei, Sean Shan-Min; Cheung, Kenny; Teodorescu, Mircea

    2015-01-01

    This paper presents a modeling and control of aerostructure developed by lattice-based cellular materials/components. The proposed aerostructure concept leverages a building block strategy for lattice-based components which provide great adaptability to varying ight scenarios, the needs of which are essential for in- ight wing shaping control. A decentralized structural control design is proposed that utilizes discrete-time lumped mass transfer matrix method (DT-LM-TMM). The objective is to develop an e ective reduced order model through DT-LM-TMM that can be used to design a decentralized controller for the structural control of a wing. The proposed approach developed in this paper shows that, as far as the performance of overall structural system is concerned, the reduced order model can be as e ective as the full order model in designing an optimal stabilizing controller.

  16. DOA Estimation Based on Real-Valued Cross Correlation Matrix of Coprime Arrays.

    Science.gov (United States)

    Li, Jianfeng; Wang, Feng; Jiang, Defu

    2017-03-20

    A fast direction of arrival (DOA) estimation method using a real-valued cross-correlation matrix (CCM) of coprime subarrays is proposed. Firstly, real-valued CCM with extended aperture is constructed to obtain the signal subspaces corresponding to the two subarrays. By analysing the relationship between the two subspaces, DOA estimations from the two subarrays are simultaneously obtained with automatic pairing. Finally, unique DOA is determined based on the common results from the two subarrays. Compared to partial spectral search (PSS) method and estimation of signal parameter via rotational invariance (ESPRIT) based method for coprime arrays, the proposed algorithm has lower complexity but achieves better DOA estimation performance and handles more sources. Simulation results verify the effectiveness of the approach.

  17. Investigation of the microcrack evolution in a Ti-based bulk metallic glass matrix composite

    Directory of Open Access Journals (Sweden)

    Yongsheng Wang

    2014-04-01

    Full Text Available The initiation and evolution behavior of the shear-bands and microcracks in a Ti-based metallic-glass–matrix composite (MGMC were investigated by using an in-situ tensile test under transmission electron microscopy (TEM. It was found that the plastic deformation of the Ti-based MGMC related with the generation of the plastic deformation zone in crystalline and shear deformation zone in glass phase near the crack tip. The dendrites can suppress the propagation of the shear band effectively. Before the rapid propagation of cracks, the extending of plastic deformation zone and shear deformation zone ahead of crack tip is the main pattern in the composite.

  18. Parameters Identification of Interface Friction Model for Ceramic Matrix Composites Based on Stress-Strain Response

    Science.gov (United States)

    Han, Xiao; Gao, Xiguang; Song, Yingdong

    2017-10-01

    An approach to identify parameters of interface friction model for Ceramic Matrix composites based on stress-strain response was developed. The stress distribution of fibers in the interface slip region and intact region of the damaged composite was determined by adopting the interface friction model. The relation between maximum strain, secant moduli of hysteresis loop and interface shear stress, interface de-bonding stress was established respectively with the method of symbolic-graphic combination. By comparing the experimental strain, secant moduli of hysteresis loop with computation values, the interface shear stress and interface de-bonding stress corresponding to first cycle were identified. Substituting the identification of parameters into interface friction model, the stress-strain curves were predicted and the predicted results fit experiments well. Besides, the influence of number of data points on identifying the value of interface parameters was discussed. And the approach was compared with the method based on the area of hysteresis loop.

  19. Investigation of materials for inert electrodes in aluminum electrodeposition cells

    Energy Technology Data Exchange (ETDEWEB)

    Haggerty, J. S.; Sadoway, D. R.

    1987-09-14

    Work was divided into major efforts. The first was the growth and characterization of specimens; the second was Hall cell performance testing. Cathode and anode materials were the subject of investigation. Preparation of specimens included growth of single crystals and synthesis of ultra high purity powders. Special attention was paid to ferrites as they were considered to be the most promising anode materials. Ferrite anode corrosion rates were studied and the electrical conductivities of a set of copper-manganese ferrites were measured. Float Zone, Pendant Drop Cryolite Experiments were undertaken because unsatisfactory choices of candidate materials were being made on the basis of a flawed set of selection criteria applied to an incomplete and sometimes inaccurate data base. This experiment was then constructed to determine whether the apparatus used for float zone crystal growth could be adapted to make a variety of important based melts and their interactions with candidate inert anode materials. The third major topic was Non Consumable Anode (Data Base, Candidate Compositions), driven by our perception that the basis for prior selection of candidate materials was inadequate. Results are presented. 162 refs., 39 figs., 18 tabs.

  20. THz spectral data analysis and components unmixing based on non-negative matrix factorization methods

    Science.gov (United States)

    Ma, Yehao; Li, Xian; Huang, Pingjie; Hou, Dibo; Wang, Qiang; Zhang, Guangxin

    2017-04-01

    In many situations the THz spectroscopic data observed from complex samples represent the integrated result of several interrelated variables or feature components acting together. The actual information contained in the original data might be overlapping and there is a necessity to investigate various approaches for model reduction and data unmixing. The development and use of low-rank approximate nonnegative matrix factorization (NMF) and smooth constraint NMF (CNMF) algorithms for feature components extraction and identification in the fields of terahertz time domain spectroscopy (THz-TDS) data analysis are presented. The evolution and convergence properties of NMF and CNMF methods based on sparseness, independence and smoothness constraints for the resulting nonnegative matrix factors are discussed. For general NMF, its cost function is nonconvex and the result is usually susceptible to initialization and noise corruption, and may fall into local minima and lead to unstable decomposition. To reduce these drawbacks, smoothness constraint is introduced to enhance the performance of NMF. The proposed algorithms are evaluated by several THz-TDS data decomposition experiments including a binary system and a ternary system simulating some applications such as medicine tablet inspection. Results show that CNMF is more capable of finding optimal solutions and more robust for random initialization in contrast to NMF. The investigated method is promising for THz data resolution contributing to unknown mixture identification.

  1. THz spectral data analysis and components unmixing based on non-negative matrix factorization methods.

    Science.gov (United States)

    Ma, Yehao; Li, Xian; Huang, Pingjie; Hou, Dibo; Wang, Qiang; Zhang, Guangxin

    2017-04-15

    In many situations the THz spectroscopic data observed from complex samples represent the integrated result of several interrelated variables or feature components acting together. The actual information contained in the original data might be overlapping and there is a necessity to investigate various approaches for model reduction and data unmixing. The development and use of low-rank approximate nonnegative matrix factorization (NMF) and smooth constraint NMF (CNMF) algorithms for feature components extraction and identification in the fields of terahertz time domain spectroscopy (THz-TDS) data analysis are presented. The evolution and convergence properties of NMF and CNMF methods based on sparseness, independence and smoothness constraints for the resulting nonnegative matrix factors are discussed. For general NMF, its cost function is nonconvex and the result is usually susceptible to initialization and noise corruption, and may fall into local minima and lead to unstable decomposition. To reduce these drawbacks, smoothness constraint is introduced to enhance the performance of NMF. The proposed algorithms are evaluated by several THz-TDS data decomposition experiments including a binary system and a ternary system simulating some applications such as medicine tablet inspection. Results show that CNMF is more capable of finding optimal solutions and more robust for random initialization in contrast to NMF. The investigated method is promising for THz data resolution contributing to unknown mixture identification. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Evaluating the environmental sustainability of biomass-based energy strategy: Using an impact matrix framework

    International Nuclear Information System (INIS)

    Weldu, Yemane W.; Assefa, Getachew

    2016-01-01

    A roadmap for a more sustainable energy strategy is complex, as its development interacts critically with the economic, social, and environmental dimensions of sustainable development. This paper applied an impact matrix method to evaluate the environmental sustainability and to identify the desirable policy objectives of biomass-based energy strategy for the case of Alberta. A matrix with the sustainability domains on one axis and areas of environmental impact on the other was presented to evaluate the nexus effect of policy objectives and bioenergy production. As per to our analysis, economic diversification, technological innovation, and resource conservation came up as the desirable policy objectives of sustainable development for Alberta because they demonstrated environmental benefits in all environmental impact categories, namely climate change, human health, and ecosystem. On the other hand, human health and ecosystem impacts were identified as trade-offs when the policy objectives for sustainability were energy security, job creation, and climate change. Thus, bioenergy can mitigate climate change but may impact human health and ecosystem which then in turn can become issues of concern. Energy strategies may result in shifting of risks from one environmental impact category to another, and from one sustainable domain to another if the technical and policy-related issues are not identified.

  3. Toward transparent nanocomposites based on polystyrene matrix and PMMA-grafted CeO2 nanoparticles.

    Science.gov (United States)

    Parlak, Onur; Demir, Mustafa M

    2011-11-01

    The association of transparent polymer and nanosized pigment particles offers attractive optical materials for various potential and existing applications. However, the particles embedded into polymers scatter light due to refractive index (RI) mismatch and reduce transparency of the resulting composite material. In this study, optical composites based on polystyrene (PS) matrix and poly(methyl methacrylate) (PMMA)-grafted CeO(2) hybrid particles were prepared. CeO(2) nanoparticles with an average diameter of 18 ± 8 nm were precipitated by treating Ce(NO(3))·6H(2)O with urea in the presence of a polymerizable surfactant, 3-methacyloxypropyltrimethoxy silane. PMMA chains were grafted on the surface of the nanoparticles upon free radical in situ solution polymerization. While blending of unmodified CeO(2) particles with PS resulted in opaque films, the transparency of the composite films was remarkably enhanced when prepared by PMMA-grafted CeO(2) hybrid particles, particularly those having a PMMA thickness of 9 nm. The improvement in transparency is presumably due to the reduction in RI mismatch between CeO(2) particles and the PS matrix when using PMMA chains at the interface.

  4. Management of investment-construction projects basing on the matrix of key events

    Directory of Open Access Journals (Sweden)

    Morozenko Andrey Aleksandrovich

    2016-11-01

    Full Text Available The article considers the current problematic issues in the management of investment-construction projects, examines the questions of efficiency increase of construction operations on the basis of the formation of a reflex-adaptive organizational structure. The authors analyzed the necessity of forming a matrix of key events in the investment-construction project (ICP, which will create the optimal structure of the project, basing on the work program for its implementation. For convenience of representing programs of the project implementation in time the authors make recommendations to consolidate the works into separate, economically independent functional blocks. It is proposed to use an algorithm of forming the matrix of an investment-construction project, considering the economic independence of the functional blocks and stages of the ICP implementation. The use of extended network model is justified, which is supplemented by organizational and structural constraints at different stages of the project, highlighting key events fundamentally influencing the further course of the ICP implementation.

  5. Improved Asymmetric Cipher Based on Matrix Power Function with Provable Security

    Directory of Open Access Journals (Sweden)

    Eligijus Sakalauskas

    2017-01-01

    Full Text Available The improved version of the author’s previously declared asymmetric cipher protocol based on matrix power function (MPF is presented. Proposed modification avoids discrete logarithm attack (DLA which could be applied to the previously declared protocol. This attack allows us to transform the initial system of MPF equations to so-called matrix multivariate quadratic (MMQ system of equations, which is a system representing a subclass of multivariate quadratic (MQ systems of equations. We are making a conjecture that avoidance of DLA in protocol, presented here, should increase its security, since an attempt to solve the initial system of MPF equations would appear to be no less complex than solving the system of MMQ equations. No algorithms are known to solve such a system of equations. Security parameters and their secure values are defined. Security analysis against chosen plaintext attack (CPA and chosen ciphertext attack (CCA is presented. Measures taken to prevent DLA attack increase the security of this protocol with respect to the previously declated protocol.

  6. Fast EEMD Based AM-Correntropy Matrix and Its Application on Roller Bearing Fault Diagnosis

    Directory of Open Access Journals (Sweden)

    Yunxiao Fu

    2016-06-01

    Full Text Available Roller bearing plays a significant role in industrial sectors. To improve the ability of roller bearing fault diagnosis under multi-rotating situation, this paper proposes a novel roller bearing fault characteristic: the Amplitude Modulation (AM based correntropy extracted from the Intrinsic Mode Functions (IMFs, which are decomposed by Fast Ensemble Empirical mode decomposition (FEEMD and employ Least Square Support Vector Machine (LSSVM to implement intelligent fault identification. Firstly, the roller bearing vibration acceleration signal is decomposed by FEEMD to extract IMFs. Secondly, IMF correntropy matrix (IMFCM as the fault feature matrix is calculated from the AM-correntropy model of the primary vibration signal and IMFs. Furthermore, depending on LSSVM, the fault identification results of the roller bearing are obtained. Through the bearing identification experiments in stationary rotating conditions, it was verified that IMFCM generates more stable and higher diagnosis accuracy than conventional fault features such as energy moment, fuzzy entropy, and spectral kurtosis. Additionally, it proves that IMFCM has more diagnosis robustness than conventional fault features under cross-mixed roller bearing operating conditions. The diagnosis accuracy was more than 84% for the cross-mixed operating condition, which is much higher than the traditional features. In conclusion, it was proven that FEEMD-IMFCM-LSSVM is a reliable technology for roller bearing fault diagnosis under the constant or multi-positioned operating conditions, and as such, it possesses potential prospects for a broad application of uses.

  7. Synthesis and Characterization of Pine Needles Reinforced RF Matrix Based Biocomposites

    Directory of Open Access Journals (Sweden)

    A. S. Singha

    2008-01-01

    Full Text Available Synthesis and characterization of pine needles reinforced thermosetting resin (Resorcinol-Formaldehyde which is most suitable as composite matrix has been reported. The polycondensation reaction between resorcinol and formaldehyde (RF in different molar ratios has been applied to the synthesis of RF polymer matrix. A thermosetting resin based composite, containing approximately 10, 20, 30 and 40% of natural fiber by weight, has been obtained by adding pine needles to the Resorcinol-Formaldehyde (RF resin. The mechanical properties of randomly oriented intimately mixed particle reinforced (Pine needles composites were determined. Effect of fiber loading in terms of weight % on mechanical properties such as tensile, compressive, and flexural and wear properties have also been evaluated. The reinforcing of the resin with Pine needles was accomplished in particle size of 200 micron by employing optimized resin. Present work reveals that mechanical properties of the RF resin increases to extensive extent when reinforced with Pine needles. Thermal (TGA/DTA and morphological studies (SEM of the resin, fiber and polymer composites thus synthesized have also been carried out.

  8. [Lake algae chemotaxonomy technology based on fluorescence excitation emission matrix and parallel factor analysis].

    Science.gov (United States)

    Chen, Xiao-Na; Han, Xiu-Rong; Su, Rong-Guo; Shi, Xiao-Yong

    2014-03-01

    An in vivo three-dimensional fluorescence method for the determination of algae community structure was developed by parallel factor (PARAFAC) analysis and CHEMTAX. The PARAFAC model was applied to fluorescence excitation-emission matrix (EEM) of 23 algae species and 12 fluorescent components were identified according to the residual sum of squares and specificity of the composition profiles of fluorescent. Based on the 12 fluorescent components, the algae species at different growth stages were correctly classified at the division level using Bayesian discriminant analysis (BDA). Then the reference fluorescent component ratio matrix was constructed for CHEMTAX, and the EEM-PARAFAC-CHEMTAX method was developed to differentiate taxonomic groups of algae. When the fluorometric method was used for 531 single-species samples, the average correct discrimination ratio (CDR) was 99.1% and the correct discrimination ratios (CDRs) were 100% at the division level except Chlorophyta, the CDR of which was 97.5%. The CDRs for 95 mixtures were above 98.5% for the dominant algae species and above 90.5% for the subdominant algae species, with average relative contents of 69.7% and 26.4%, respectively. This technique would be of great aid when low-cost and rapid analysis is needed for samples in a large batch.

  9. Shunt Active and Series Active Filters-Based Power Quality Conditioner for Matrix Converter

    Directory of Open Access Journals (Sweden)

    P. Jeno Paul

    2011-01-01

    Full Text Available This paper proposes a series active filter and shunt active filter to minimize the power quality impact present in matrix converters instead of passive filter. A matrix converter produces significant harmonics and nonstandard frequency components into load. The proposed system compensates the sag and swell problems efficiently in matrix converter. The proposed system has been tested and validated on the matrix converter using MATLAB/Simulink software. Simulated results confirm that the active power filters can maintain high performance for matrix converter.

  10. Early resumption of physical activities leads to inferior clinical outcomes after matrix-based autologous chondrocyte implantation in the knee.

    Science.gov (United States)

    Niethammer, Thomas R; Müller, Peter E; Safi, Elem; Ficklscherer, Andreas; Roßbach, Björn P; Jansson, Volkmar; Pietschmann, Matthias F

    2014-06-01

    Matrix-based autologous chondrocyte implantation is a well-established operation procedure for full cartilage defects. When to resume physical activity after matrix-based autologous chondrocyte implantation is controversial. Our hypothesis was that early resumption of physical activity leads to a worse clinical outcome after matrix-based autologous chondrocyte implantation in the knee two years post-operatively. Physical activity is defined as any kind of impact sport. Forty-four patients with cartilage defects of the knee were treated with matrix-based autologous chondrocyte implantation (Novocart3D). All patients were assessed preoperatively and after a period of 24 months with the University of California Los Angeles (UCLA) Activity score. The return to physical activities or sports after matrix-based autologous chondrocyte implantation was documented. Patients were evaluated using the International Knee Documentation Committee Knee Examination Form and visual analogue scale for pain after 6, 12 and 24 months. Fifty-five percent showed an unchanged level of physical activity in the UCLA Activity score post-operatively. About 35% showed a lower level and 10% a higher level of physical activity. The average return to physical activities or sports after matrix-based autologous chondrocyte implantation procedure was 10.2 months. Patients with a later return of sports after 12 months showed significantly better clinical results after two years. In particular, patients who started practicing impact sport after 12 months post-operatively showed significantly better results. Resuming physical activity including impact sports without waiting at least 12 months after the operation leads to inferior outcomes up to 24 months after matrix-based autologous chondrocyte implantation. Level IV.

  11. Organic matrix based slow release fertilizer enhances plant growth, nitrate assimilation and seed yield of Indian mustard (Brassica juncea L.).

    Science.gov (United States)

    Sharma, Vinod K; Singh, Rana P

    2011-09-01

    Field experiments were conducted to study the effect of organic matrix based slow release fertilizers (SRFs) on plant growth, nitrate assimilation and seed yield of Brassica juncea L. cv, pusa bold. The agro-waste materials like cow dung, clay soil, neem leaves and rice bran were mixed together in 2:2:1:1 ratio and used as organic matrix for the immobilization of chemical fertilizer nutrients with commercial grade saresh (Acacia gum, 15% solution) as binder. Different fertilizer treatments were organic matrix based slow release fertilizers, SRF-I (542.0 kg ha(-1)); SRF-II (736.5 kg ha(-1)) and chemical fertilizer combinations, boron (3 kg ha(-1))+sulphur (15 kg ha(-1))+nitrogen (80 kg ha(-1)) and boron (3 kg ha(-1)) + sulphur (15 kg ha(-1))+nitrogen (80 kg ha(-1))+phosphorus (15 kg ha(-1))+potassium (100 kg ha(-1)). Organic matrix based SRF-II released ammonium up to 50-d in wetsoil under laboratory conditions which showed maximum retention of the nutrients. Avery significant increase in plant growth, nitrate assimilation and seed yield was recorded in organic matrix based SRF-II applied plants. The maximum percent increase in biomass production was observed with organic matrix based SRF-II (increase of 65.8% in root fresh weight, 38.0% in root dry weight, 45.9% in leaf fresh weight plant(-1) and 27.5 % in leaf dry weight plant(-1) in 60-d old plants). It also increased the acquisition and assimilation of nitrate from the plant's rhizosphere which was evident by 45.6% increase in nitrate, 27.5% in nitrite and 11.7% in nitrate reductase activity (NRA) in leaves of 45-d old plants over control. The organic matrix based SRF-II significantly increased the seed yield by 28% in Indian mustard. Cost analysis revealed thatthis formulation is cost effective as it is based on agro waste materials.

  12. A matrix model for valuing anesthesia service with the resource-based relative value system

    Science.gov (United States)

    Sinclair, David R; Lubarsky, David A; Vigoda, Michael M; Birnbach, David J; Harris, Eric A; Behrens, Vicente; Bazan, Richard E; Williams, Steve M; Arheart, Kristopher; Candiotti, Keith A

    2014-01-01

    Background The purpose of this study was to propose a new crosswalk using the resource-based relative value system (RBRVS) that preserves the time unit component of the anesthesia service and disaggregates anesthesia billing into component parts (preoperative evaluation, intraoperative management, and postoperative evaluation). The study was designed as an observational chart and billing data review of current and proposed payments, in the setting of a preoperative holing area, intraoperative suite, and post anesthesia care unit. In total, 1,195 charts of American Society of Anesthesiology (ASA) physical status 1 through 5 patients were reviewed. No direct patient interventions were undertaken. Results Spearman correlations between the proposed RBRVS billing matrix payments and the current ASA relative value guide methodology payments were strong (r=0.94–0.96, P<0.001 for training, test, and overall). The proposed RBRVS-based billing matrix yielded payments that were 3.0%±1.34% less than would have been expected from commercial insurers, using standard rates for commercial ASA relative value units and RBRVS relative value units. Compared with current Medicare reimbursement under the ASA relative value guide, reimbursement would almost double when converting to an RBRVS billing model. The greatest increases in Medicare reimbursement between the current system and proposed billing model occurred as anesthetic management complexity increased. Conclusion The new crosswalk correlates with existing evaluation and management and intensive care medicine codes in an essentially revenue neutral manner when applied to the market-based rates of commercial insurers. The new system more highly values delivery of care to more complex patients undergoing more complex surgery and better represents the true value of anesthetic case management. PMID:25336964

  13. Light weight polymer matrix composite material

    Science.gov (United States)

    Bowles, Kenneth J. (Inventor); Lowell, Carl E. (Inventor)

    1991-01-01

    A graphite fiber reinforced polymer matrix is layed up, cured, and thermally aged at about 750.degree. F. in the presence of an inert gas. The heat treatment improves the structural integrity and alters the electrical conductivity of the materials. In the preferred embodiment PMR-15 polyimides and Celion-6000 graphite fibers are used.

  14. Scattering matrix analysis for evaluating the photocurrent in hydrogenated-amorphous-silicon-based thin film solar cells.

    Science.gov (United States)

    Shin, Myunghun; Lee, Seong Hyun; Lim, Jung Wook; Yun, Sun Jin

    2014-11-01

    A scattering matrix (S-matrix) analysis method was developed for evaluating hydrogenated amorphous silicon (a-Si:H)-based thin film solar cells. In this approach, light wave vectors A and B represent the incoming and outgoing behaviors of the incident solar light, respectively, in terms of coherent wave and incoherent intensity components. The S-matrix determines the relation between A and B according to optical effects such as reflection and transmission, as described by the Fresnel equations, scattering at the boundary surfaces, or scattering within the propagation medium, as described by the Beer-Lambert law and the change in the phase of the propagating light wave. This matrix can be used to evaluate the behavior of angle-incident coherent and incoherent light simultaneously, and takes into account not only the light scattering process at material boundaries (haze effects) but also nonlinear optical processes within the material. The optical parameters in the S-matrix were determined by modeling both a 2%-gallium-doped zinc oxide transparent conducting oxide and germanium-compounded a-Si:H (a-SiGe:H). Using the S-matrix equations, the photocurrent for an a-Si:H/a-SiGe:H tandem cell and the optical loss in semitransparent a-Si:H solar cells for use in building-integrated photovoltaic applications were analyzed. The developed S-matrix method can also be used as a general analysis tool for various thin film solar cells.

  15. A Numerical Matrix-Based method in Harmonic Studies in Wind Power Plants

    DEFF Research Database (Denmark)

    Dowlatabadi, Mohammadkazem Bakhshizadeh; Hjerrild, Jesper; Kocewiak, Łukasz Hubert

    2016-01-01

    In the low frequency range, there are some couplings between the positive- and negative-sequence small-signal impedances of the power converter due to the nonlinear and low bandwidth control loops such as the synchronization loop. In this paper, a new numerical method which also considers...... these couplings will be presented. The numerical data are advantageous to the parametric differential equations, because analysing the high order and complex transfer functions is very difficult, and finally one uses the numerical evaluation methods. This paper proposes a numerical matrix-based method, which...... is not only able to deal with those mentioned numerical data, but also it is able to consider all couplings between the positive and negative sequences....

  16. Design of Electronic Medical Record User Interfaces: A Matrix-Based Method for Improving Usability

    Directory of Open Access Journals (Sweden)

    Kushtrim Kuqi

    2013-01-01

    Full Text Available This study examines a new approach of using the Design Structure Matrix (DSM modeling technique to improve the design of Electronic Medical Record (EMR user interfaces. The usability of an EMR medication dosage calculator used for placing orders in an academic hospital setting was investigated. The proposed method captures and analyzes the interactions between user interface elements of the EMR system and groups elements based on information exchange, spatial adjacency, and similarity to improve screen density and time-on-task. Medication dose adjustment task time was recorded for the existing and new designs using a cognitive simulation model that predicts user performance. We estimate that the design improvement could reduce time-on-task by saving an average of 21 hours of hospital physicians’ time over the course of a month. The study suggests that the application of DSM can improve the usability of an EMR user interface.

  17. Matrix- and tensor-based recommender systems for the discovery of currently unknown inorganic compounds

    Science.gov (United States)

    Seko, Atsuto; Hayashi, Hiroyuki; Kashima, Hisashi; Tanaka, Isao

    2018-01-01

    Chemically relevant compositions (CRCs) and atomic arrangements of inorganic compounds have been collected as inorganic crystal structure databases. Machine learning is a unique approach to search for currently unknown CRCs from vast candidates. Herein we propose matrix- and tensor-based recommender system approaches to predict currently unknown CRCs from database entries of CRCs. Firstly, the performance of the recommender system approaches to discover currently unknown CRCs is examined. A Tucker decomposition recommender system shows the best discovery rate of CRCs as the majority of the top 100 recommended ternary and quaternary compositions correspond to CRCs. Secondly, systematic density functional theory (DFT) calculations are performed to investigate the phase stability of the recommended compositions. The phase stability of the 27 compositions reveals that 23 currently unknown compounds are newly found to be stable. These results indicate that the recommender system has great potential to accelerate the discovery of new compounds.

  18. Peptide-Based Selective Inhibitors of Matrix Metalloproteinase-Mediated Activities

    Directory of Open Access Journals (Sweden)

    Margaret W. Ndinguri

    2012-11-01

    Full Text Available The matrix metalloproteinases (MMPs exhibit a broad array of activities, some catalytic and some non-catalytic in nature. An overall lack of selectivity has rendered small molecule, active site targeted MMP inhibitors problematic in execution. Inhibitors that favor few or individual members of the MMP family often take advantage of interactions outside the enzyme active site. We presently focus on peptide-based MMP inhibitors and probes that do not incorporate conventional Zn2+ binding groups. In some cases, these inhibitors and probes function by binding only secondary binding sites (exosites, while others bind both exosites and the active site. A myriad of MMP mediated-activities beyond selective catalysis can be inhibited by peptides, particularly cell adhesion, proliferation, motility, and invasion. Selective MMP binding peptides comprise highly customizable, unique imaging agents. Areas of needed improvement for MMP targeting peptides include binding affinity and stability.

  19. An infrared small target detection method based on nonnegative matrix factorization and compressed sensing

    Science.gov (United States)

    Chen, Qiwei; Wang, Yiming

    2017-07-01

    According to the low rank property of the background and the sparse features of the target in infrared image, a novel infrared small target detection method based on the nonnegative matrix factorization (NMF) and compressed sensing technology was presented in this paper. This method trained background model through NMF, and then sampled the infrared image sequences directly using the block compressed sensing technology. Through the alternating direction method of multipliers (ADMM), the infrared small target was extracted and the background was recovered from the image. At the same time, the background was updated by the update algorithm, to adapt to the changes in the background. The simulation results show that the proposed method can detect the infrared target precisely and efficiently.

  20. Automated morphological classification of galaxies based on projection gradient nonnegative matrix factorization algorithm

    Science.gov (United States)

    Selim, I. M.; Abd El Aziz, Mohamed

    2017-04-01

    The development of automated morphological classification schemes can successfully distinguish between morphological types of galaxies and can be used for studies of the formation and subsequent evolution of galaxies in our universe. In this paper, we present a new automated machine supervised learning astronomical classification scheme based on the Nonnegative Matrix Factorization algorithm. This scheme is making distinctions between all types roughly corresponding to Hubble types such as elliptical, lenticulars, spiral, and irregular galaxies. The proposed algorithm is performed on two examples with different number of image (small dataset contains 110 image and large dataset contains 700 images). The experimental results show that galaxy images from EFIGI catalog can be classified automatically with an accuracy of ˜93% for small and ˜92% for large number. These results are in good agreement when compared with the visual classifications.

  1. Optical Fibre NO₂ Sensor Based on Lutetium Bisphthalocyanine in a Mesoporous Silica Matrix.

    Science.gov (United States)

    Debliquy, Marc; Lahem, Driss; Bueno-Martinez, Antonio; Caucheteur, Christophe; Bouvet, Marcel; Recloux, Isaline; Raskin, Jean-Pierre; Olivier, Marie-Georges

    2018-03-01

    In this article, we describe a NO₂ sensor consisting of a coating based on lutetium bisphthalocyanine (LuPc₂) in mesoporous silica. The sensor exploits the absorption spectrum change of this material which strongly and reversibly decreases in contact with NO₂. NO₂ is measured by following the amplitude change in the reflected spectrum of the coating deposited on the tip of a silica fibre. As diffusion of NO₂ in LuPc₂ is slow, the response time could be slow. To reduce it, the active molecules are dispersed in a mesoporous silica matrix deposited by a sol-gel process (Evaporation Induced Self Assembly) avoiding the formation of large crystals. Doing so, the response is fairly fast. As the recovery is slow at room temperature, the recovery time is reduced by exposure to UV light at 365 nm. This UV light is directly introduced in the fibre yielding a practical sensor sensitive to NO₂ in the ppm range suitable for pollution monitoring.

  2. Matrix pencil method-based reference current generation for shunt active power filters

    DEFF Research Database (Denmark)

    Terriche, Yacine; Golestan, Saeed; Guerrero, Josep M.

    2018-01-01

    response and works well under distorted and unbalanced voltage. Moreover, the proposed method can estimate the voltage phase accurately; this property enables the algorithm to compensate for both power factor and current unbalance. The effectiveness of the proposed method is verified using simulation...... are using the discrete Fourier transform (DFT) in the frequency domain or the instantaneous p–q theory and the synchronous reference frame in the time domain. The DFT, however, suffers from the picket-fence effect and spectral leakage. On the other hand, the DFT takes at least one cycle of the nominal...... frequency. The time-domain methods show a weakness under voltage distortion, which requires prior filtering techniques. The aim of this study is to present a fast yet effective method for generating the RCC for SAPFs. The proposed method, which is based on the matrix pencil method, has a fast dynamic...

  3. Preparation of Al-based metal matrix composites reinforced by Cu coated SiC particles

    Energy Technology Data Exchange (ETDEWEB)

    Wang Hailong; Zhang Rui; Xu Hongliang; Lu Hongxia; Guan Shaokang [Coll. of Materials Engineering, Zhengzhou Univ., HEN (China)

    2005-07-01

    In order to improve the interfacial behavior between SiC and Al, a surface layer of Cu was coated on SiC particles. The influence of pH value on the coating process was analyzed. A powder metallurgy method was used to prepare the Al-based metal matrix composites (MMCs). SEM, XRD techniques were used to characterize the sintered compacts. It was found that the optimized pH value during the coating process was 1{proportional_to}2. The specimen showed the maximum density when sintered at 750 C. Inter-metallic compound of Al{sub 3.21}Si{sub 0.47} was detected which contributed to the enhancement at the interface between SiC and Al. The hardness of the composites is improved to 90 MPa. (orig.)

  4. Micromechanical modeling of tungsten-based bulk metallic glass matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Li Hao [Department of Mechanical Engineering-Engineering Mechanics, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931 (United States); Li Ke [Department of Mechanical Engineering, Texas A and M University, TAMU 3123, College Station, TX 77843 (United States)]. E-mail: keli@tamu.edu; Subhash, Ghatu [Department of Mechanical Engineering-Engineering Mechanics, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931 (United States); Kecskes, Laszlo J. [Weapons and Materials Research Directorate, US Army Research Laboratory, Aberdeen Proving Ground, MD 21005 (United States); Dowding, Robert J. [Weapons and Materials Research Directorate, US Army Research Laboratory, Aberdeen Proving Ground, MD 21005 (United States)

    2006-08-15

    Micromechanics models are developed for tungsten (W)-based bulk metallic glass (BMG) matrix composites employing the Voronoi tessellation technique and the finite element (FE) method. The simulation results indicate that the computed elastic moduli are close to those measured in the experiments. The predicted stress-strain curves agree well with their experimentally obtained counterparts in the early stage of the plastic deformation. An increase in the W volume fraction leads to a decrease in the yield stress and an increase in the Young's modulus of the composite. In addition, contours of equivalent plastic strain for increasing applied strains provide an explanation why shear bands were observed in the glassy phase, along the W/BMG interface, and in the W phase of failed W/BMG composite specimens.

  5. A current controlled matrix converter for wind energy conversion systems based on permanent magnet synchronous generator

    Directory of Open Access Journals (Sweden)

    Naggar H. Saad

    2016-05-01

    Full Text Available The main challenges of wind energy conversion systems (WECS are to maximize the energy capture from the wind and injecting reactive power during the fault. This paper presents a current controlled matrix converter to interface Permanent Magnet Synchronous Generators (PMSG based WECS with the grid. To achieve fast dynamic response with reduced current ripples, a hysteresis current control is utilized. The proposed control system decouples the active and reactive components of the PMSG current to extract the maximum power from the wind at a given wind velocity and to inject reactive power to the grid. Reactive power injection during the fault satisfying the grid-codes requirement. The proposed WECS has been modeled and simulated using PSCAD/EMTDC software package.

  6. A matrix model for valuing anesthesia service with the resource-based relative value system.

    Science.gov (United States)

    Sinclair, David R; Lubarsky, David A; Vigoda, Michael M; Birnbach, David J; Harris, Eric A; Behrens, Vicente; Bazan, Richard E; Williams, Steve M; Arheart, Kristopher; Candiotti, Keith A

    2014-01-01

    The purpose of this study was to propose a new crosswalk using the resource-based relative value system (RBRVS) that preserves the time unit component of the anesthesia service and disaggregates anesthesia billing into component parts (preoperative evaluation, intraoperative management, and postoperative evaluation). The study was designed as an observational chart and billing data review of current and proposed payments, in the setting of a preoperative holing area, intraoperative suite, and post anesthesia care unit. In total, 1,195 charts of American Society of Anesthesiology (ASA) physical status 1 through 5 patients were reviewed. No direct patient interventions were undertaken. Spearman correlations between the proposed RBRVS billing matrix payments and the current ASA relative value guide methodology payments were strong (r=0.94-0.96, Pbilling matrix yielded payments that were 3.0%±1.34% less than would have been expected from commercial insurers, using standard rates for commercial ASA relative value units and RBRVS relative value units. Compared with current Medicare reimbursement under the ASA relative value guide, reimbursement would almost double when converting to an RBRVS billing model. The greatest increases in Medicare reimbursement between the current system and proposed billing model occurred as anesthetic management complexity increased. The new crosswalk correlates with existing evaluation and management and intensive care medicine codes in an essentially revenue neutral manner when applied to the market-based rates of commercial insurers. The new system more highly values delivery of care to more complex patients undergoing more complex surgery and better represents the true value of anesthetic case management.

  7. Theory and implementation of H-matrix based iterative and direct solvers for Helmholtz and elastodynamic oscillatory kernels

    Science.gov (United States)

    Chaillat, Stéphanie; Desiderio, Luca; Ciarlet, Patrick

    2017-12-01

    In this work, we study the accuracy and efficiency of hierarchical matrix (H-matrix) based fast methods for solving dense linear systems arising from the discretization of the 3D elastodynamic Green's tensors. It is well known in the literature that standard H-matrix based methods, although very efficient tools for asymptotically smooth kernels, are not optimal for oscillatory kernels. H2-matrix and directional approaches have been proposed to overcome this problem. However the implementation of such methods is much more involved than the standard H-matrix representation. The central questions we address are twofold. (i) What is the frequency-range in which the H-matrix format is an efficient representation for 3D elastodynamic problems? (ii) What can be expected of such an approach to model problems in mechanical engineering? We show that even though the method is not optimal (in the sense that more involved representations can lead to faster algorithms) an efficient solver can be easily developed. The capabilities of the method are illustrated on numerical examples using the Boundary Element Method.

  8. MOORA-Based Tribological Studies on Red Mud Reinforced Aluminum Metal Matrix Composites

    Directory of Open Access Journals (Sweden)

    S. Rajesh

    2013-01-01

    Full Text Available This paper presents the findings of an experimental investigation on the effects of applied load, sliding velocity, wt.% of reinforcement and hardness of the counterface material in dry sliding wear studies performed on red mud-based aluminum metal matrix composites (MMC. The specific wear rate and the coefficient of friction are considered as the output quality characteristics. Taguchi-based L9 orthogonal array has been used to accomplish the objective of the experimental study. Analysis of variance (ANOVA is employed to find the optimal setting and the effect of each parameter on the output performance characteristics. It has been observed that optimal factor setting for each output performance is different. In order to minimize the two responses simultaneously, multiobjective optimization based on ratio analysis (MOORA is adopted. MOORA revealed that the optimal combination of the dry sliding wear parameters for the multiperformance characteristics of the red mud based aluminium is the set normal load at 20 N, sliding velocity 3 m/s, % of reinforcement 20%, and counterface hardness of the material 58 HRC.

  9. Transformation Matrix for Time Discretization Based on Tustin’s Method

    Directory of Open Access Journals (Sweden)

    Yiming Jiang

    2014-01-01

    Full Text Available This paper studies rules in transformation of transfer function through time discretization. A method of using transformation matrix to realize bilinear transform (also known as Tustin’s method is presented. This method can be described as the conversion between the coefficients of transfer functions, which are expressed as transform by certain matrix. For a polynomial of degree n, the corresponding transformation matrix of order n exists and is unique. Furthermore, the transformation matrix can be decomposed into an upper triangular matrix multiplied with another lower triangular matrix. And both have obvious regularity. The proposed method can achieve rapid bilinear transform used in automatic design of digital filter. The result of numerical simulation verifies the correctness of the theoretical results. Moreover, it also can be extended to other similar problems. Example in the last throws light on this point.

  10. Method of making molten carbonate fuel cell ceramic matrix tape

    Science.gov (United States)

    Maricle, Donald L.; Putnam, Gary C.; Stewart, Jr., Robert C.

    1984-10-23

    A method of making a thin, flexible, pliable matrix material for a molten carbonate fuel cell is described. The method comprises admixing particles inert in the molten carbonate environment with an organic polymer binder and ceramic particle. The composition is applied to a mold surface and dried, and the formed compliant matrix material removed.

  11. Thermal Analysis of Solid Fuels in an Inert Atmosphere

    Science.gov (United States)

    Kijo-Kleczkowska, Agnieszka; Szumera, Magdalena; Środa, Katarzyna

    2017-12-01

    The paper takes the analysis of thermal studies of different types of fuels. It allowed diversification of fuels depending on their composition and origin. Consideration of coal, biomass and waste (coal mule, sewage sludge) as fuel is nowadays an important aspect of energy in our country. It should be emphasized that Poland power engineering is based up to 95% on coal - the primary fuel. Mining industry, forced to deliver power engineering more and better fuel, must however, use a deeper cleaning of coal. This results in a continuous increase waste in the form of mule flotation. The best method of disposing these mule is combustion and co-combustion with other fuels. On the other hand, commonly increasing awareness state of the environment and the need to reduce CO2 emissions energy industry have committed to implement alternative solutions in order to gain power, through, i.a.: development technologies use of biomass, which is one of the most promising renewable energy sources in Poland. The paper presents the results of research TG-DTA fuels made in an inert atmosphere.

  12. Extending the trend vector: The trend matrix and sample-based partial least squares

    Science.gov (United States)

    Sheridan, Robert P.; Nachbar, Robert B.; Bush, Bruce L.

    1994-06-01

    Trend vector analysis [Carhart, R.E. et al., J. Chem. Inf. Comput. Sci., 25 (1985) 64], in combination with topological descriptors such as atom pairs, has proved useful in drug discovery for ranking large collections of chemical compounds in order of predicted biological activity. The compounds with the highest predicted activities, upon being tested, often show a several-fold increase in the fraction of active compounds relative to a randomly selected set. A trend vector is simply the one-dimensional array of correlations between the biological activity of interest and a set of properties or `descriptors' of compounds in a training set. This paper examines two methods for generalizing the trend vector to improve the predicted rank order. The trend matrix method finds the correlations between the residuals and the simultaneous occurrence of descriptors, which are stored in a two-dimensional analog of the trend vector. The SAMPLS method derives a linear model by partial least squares (PLS), using the `sample-based' formulation of PLS [Bush, B.L. and Nachbar, R.B., J. Comput.-Aided Mol. Design, 7 (1993) 587] for efficiency in treating the large number of descriptors. PLS accumulates a predictive model as a sum of linear components. Expressed as a vector of prediction coefficients on properties, the first PLS component is proportional to the trend vector. Subsequent components adjust the model toward full least squares. For both methods the residuals decrease, while the risk of overfitting the training set increases. We therefore also describe statistical checks to prevent overfitting. These methods are applied to two data sets, a small homologous series of disubstituted piperidines, tested on the dopamine receptor, and a large set of diverse chemical structures, some of which are active at the muscarinic receptor. Each data set is split into a training set and a test set, and the activities in the test set are predicted from a fit on the training set. Both the trend

  13. Matrix Factorisation-based Calibration For Air Quality Crowd-sensing

    Science.gov (United States)

    Dorffer, Clement; Puigt, Matthieu; Delmaire, Gilles; Roussel, Gilles; Rouvoy, Romain; Sagnier, Isabelle

    2017-04-01

    sensors share some information using the APISENSE® crowdsensing platform and we aim to calibrate the sensor responses from the data directly. For that purpose, we express the sensor readings as a low-rank matrix with missing entries and we revisit self-calibration as a Matrix Factorization (MF) problem. In our proposed framework, one factor matrix contains the calibration parameters while the other is structured by the calibration model and contains some values of the sensed phenomenon. The MF calibration approach also uses the precise measurements from ATMO—the French public institution—to drive the calibration of the mobile sensors. MF calibration can be improved using, e.g., the mean calibration parameters provided by the sensor manufacturers, or using sparse priors or a model of the physical phenomenon. All our approaches are shown to provide a better calibration accuracy than matrix-completion-based and robust-regression-based methods, even in difficult scenarios involving a lot of missing data and/or very few accurate references. When combined with a dictionary of air quality patterns, our experiments suggest that MF is not only able to perform sensor network calibration but also to provide detailed maps of air quality.

  14. Mobile inert gas generator for attic oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Owens, H.B. Jr.; Mosby, J.; Anson, R.H.

    1969-01-01

    Attic oil is usually defined as that oil which is trapped upstructure of the structurally highest producible well in a reservoir. If it is not economically feasible to drill a well for this oil accumulation, attic oil recovery by gas displacement is a possible secondary recovery method. The mechanics of the method are that gas is injected into the structurally highest well, the gas migrating up dip into the attic, forcing the oil downdip where it can be produced from the injection well or other wells in the reservoir. Where natural gas is in short supply or if injected gas cannot be recovered, inert gas generators for gas injection have a practical application. Oil accumulations found over and around piercement-type salt domes, such as the Bayou Des Allemands field, are usually excellent prospects for attic oil recovery by inert gas injection. After an economical comparison between recovery by natural gas or inert gas injection, it was found that the inert gas generator would be advantageous; therefore, an inert gas generator mounted on a cement barge was purchased. This study deals with this equipment which has now been in operation for one yr.

  15. Computational Screening of MOF-Based Mixed Matrix Membranes for CO2/N2 Separations

    Directory of Open Access Journals (Sweden)

    Zeynep Sumer

    2016-01-01

    Full Text Available Atomically detailed simulations were used to examine CO2/N2 separation potential of metal organic framework- (MOF- based mixed matrix membranes (MMMs in this study. Gas permeability and selectivity of 700 new MMMs composed of 70 different MOFs and 10 different polymers were calculated for CO2/N2 separation. This is the largest number of MOF-based MMMs for which computational screening is done to date. Selecting the appropriate MOFs as filler particles in polymers resulted in MMMs that have higher CO2/N2 selectivities and higher CO2 permeabilities compared to pure polymer membranes. We showed that, for polymers that have low CO2 permeabilities but high CO2 selectivities, the identity of the MOF used as filler is not important. All MOFs enhanced the CO2 permeabilities of this type of polymers without changing their selectivities. Several MOF-based MMMs were identified to exceed the upper bound established for polymers. The methods we introduced in this study will create many opportunities to select the MOF/polymer combinations with useful properties for CO2 separation applications.

  16. A Novel CSR-Based Sparse Matrix-Vector Multiplication on GPUs

    Directory of Open Access Journals (Sweden)

    Guixia He

    2016-01-01

    Full Text Available Sparse matrix-vector multiplication (SpMV is an important operation in scientific computations. Compressed sparse row (CSR is the most frequently used format to store sparse matrices. However, CSR-based SpMVs on graphic processing units (GPUs, for example, CSR-scalar and CSR-vector, usually have poor performance due to irregular memory access patterns. This motivates us to propose a perfect CSR-based SpMV on the GPU that is called PCSR. PCSR involves two kernels and accesses CSR arrays in a fully coalesced manner by introducing a middle array, which greatly alleviates the deficiencies of CSR-scalar (rare coalescing and CSR-vector (partial coalescing. Test results on a single C2050 GPU show that PCSR fully outperforms CSR-scalar, CSR-vector, and CSRMV and HYBMV in the vendor-tuned CUSPARSE library and is comparable with a most recently proposed CSR-based algorithm, CSR-Adaptive. Furthermore, we extend PCSR on a single GPU to multiple GPUs. Experimental results on four C2050 GPUs show that no matter whether the communication between GPUs is considered or not PCSR on multiple GPUs achieves good performance and has high parallel efficiency.

  17. Carbon fiber polymer-matrix structural composites for electrical-resistance-based sensing

    Science.gov (United States)

    Wang, Daojun

    This dissertation has advanced the science and technology of electrical-resistance-based sensing of strain/stress and damage using continuous carbon fiber epoxy-matrix composites, which are widely used for aircraft structures. In particular, it has extended the technology of self-sensing of carbon fiber polymer-matrix composites from uniaxial longitudinal loading and flexural loading to uniaxial through-thickness loading and has extended the technology from structural composite self-sensing to the use of the composite (specifically a one-lamina composite) as an attached sensor. Through-thickness compression is encountered in the joining of composite components by fastening. Uniaxial through-thickness compression results in strain-induced reversible decreases in the through-thickness and longitudinal volume resistivities, due to increase in the fiber-fiber contact in the through-thickness direction, and minor-damage-induced irreversible changes in these resistivities. The Poisson effect plays a minor role. The effects in the longitudinal resistivity are small compared to those in the through-thickness direction, but longitudinal resistance measurement is more amenable to practical implementation in structures than through-thickness resistance measurement. The irreversible effects are associated with an increase in the through-thickness resistivity and a decrease in the longitudinal resistivity. The through-thickness gage factor is up to 5.1 and decreases with increasing compressive strain above 0.2%. The reversible fractional change in through-thickness resistivity per through-thickness strain is up to 4.0 and decreases with increasing compressive strain. The irreversible fractional change in through-thickness resistivity per unit through-thickness strain is around -1.1 and is independent of the strain. The sensing is feasible by measuring the resistance away from the stressed region, though the effectiveness is less than that at the stressed region. A one

  18. Generalized canonical analysis based on optimizing matrix correlations and a relation with IDIOSCAL

    NARCIS (Netherlands)

    Kiers, Henk A.L.; Cléroux, R.; Ten Berge, Jos M.F.

    1994-01-01

    Carroll's method for generalized canonical analysis of two or more sets of variables is shown to optimize the sum of squared inner-product matrix correlations between a consensus matrix and matrices with canonical variates for each set of variables. In addition, the method that analogously optimizes

  19. Development of an integrated system for activity-based profiling of matrix metallo-proteases

    NARCIS (Netherlands)

    Freije, Jan Robert

    2006-01-01

    Matrix metallo-proteases constitute a family of extracellular zinc-dependent endopeptidases that are involved in degradation of extracellular matrix (ECM) components and other bioactive non-ECM molecules. A plethora of studies have implicated important roles for MMPs in many diseases (including

  20. Disturbance Observer-Based Simple Nonlinearity Compensation for Matrix Converter Drives

    DEFF Research Database (Denmark)

    Lee, Kyo-Beum; Blaabjerg, Frede

    2009-01-01

    This paper presents a new method to compensate the nonlinearity for matrix converter drives using disturbance observer. The nonlinearity of matrix converter drives such as commutation delay, turn-on and turn-off time of switching device, and on-state switching device voltage drop is modeled...

  1. A matrix model for valuing anesthesia service with the resource-based relative value system

    Directory of Open Access Journals (Sweden)

    Sinclair DR

    2014-10-01

    Full Text Available David R Sinclair,1 David A Lubarsky,1 Michael M Vigoda,1 David J Birnbach,1 Eric A Harris,1 Vicente Behrens,1 Richard E Bazan,1 Steve M Williams,1 Kristopher Arheart,2 Keith A Candiotti1 1Department of Anesthesiology, Perioperative Medicine and Pain Management, 2Department of Public Health Sciences, Division of Biostatistics, University of Miami Miller School of Medicine, Miami, FL, USA Background: The purpose of this study was to propose a new crosswalk using the resource-based relative value system (RBRVS that preserves the time unit component of the anesthesia service and disaggregates anesthesia billing into component parts (preoperative evaluation, intraoperative management, and postoperative evaluation. The study was designed as an observational chart and billing data review of current and proposed payments, in the setting of a preoperative holing area, intraoperative suite, and post anesthesia care unit. In total, 1,195 charts of American Society of Anesthesiology (ASA physical status 1 through 5 patients were reviewed. No direct patient interventions were undertaken. Results: Spearman correlations between the proposed RBRVS billing matrix payments and the current ASA relative value guide methodology payments were strong (r=0.94–0.96, P<0.001 for training, test, and overall. The proposed RBRVS-based billing matrix yielded payments that were 3.0%±1.34% less than would have been expected from commercial insurers, using standard rates for commercial ASA relative value units and RBRVS relative value units. Compared with current Medicare reimbursement under the ASA relative value guide, reimbursement would almost double when converting to an RBRVS billing model. The greatest increases in Medicare reimbursement between the current system and proposed billing model occurred as anesthetic management complexity increased. Conclusion: The new crosswalk correlates with existing evaluation and management and intensive care medicine codes in an

  2. Hessian regularization based non-negative matrix factorization for gene expression data clustering.

    Science.gov (United States)

    Liu, Xiao; Shi, Jun; Wang, Congzhi

    2015-01-01

    Since a key step in the analysis of gene expression data is to detect groups of genes that have similar expression patterns, clustering technique is then commonly used to analyze gene expression data. Data representation plays an important role in clustering analysis. The non-negative matrix factorization (NMF) is a widely used data representation method with great success in machine learning. Although the traditional manifold regularization method, Laplacian regularization (LR), can improve the performance of NMF, LR still suffers from the problem of its weak extrapolating power. Hessian regularization (HR) is a newly developed manifold regularization method, whose natural properties make it more extrapolating, especially for small sample data. In this work, we propose the HR-based NMF (HR-NMF) algorithm, and then apply it to represent gene expression data for further clustering task. The clustering experiments are conducted on five commonly used gene datasets, and the results indicate that the proposed HR-NMF outperforms LR-based NMM and original NMF, which suggests the potential application of HR-NMF for gene expression data.

  3. Two-Link Flexible Manipulator Control Using Sliding Mode Control Based Linear Matrix Inequality

    Science.gov (United States)

    Zulfatman; Marzuki, Mohammad; Alif Mardiyah, Nur

    2017-04-01

    Two-link flexible manipulator is a manipulator robot which at least one of its arms is made of lightweight material and not rigid. Flexible robot manipulator has some advantages over the rigid robot manipulator, such as lighter, requires less power and costs, and to result greater payload. However, suitable control algorithm to maintain the two-link flexible robot manipulator in accurate positioning is very challenging. In this study, sliding mode control (SMC) was employed as robust control algorithm due to its insensitivity on the system parameter variations and the presence of disturbances when the system states are sliding on a sliding surface. SMC algorithm was combined with linear matrix inequality (LMI), which aims to reduce the effects of chattering coming from the oscillation of the state during sliding on the sliding surface. Stability of the control algorithm is guaranteed by Lyapunov function candidate. Based on simulation works, SMC based LMI resulted in better performance improvements despite the disturbances with significant chattering reduction. This was evident from the decline of the sum of squared tracking error (SSTE) and the sum of squared of control input (SSCI) indexes respectively 25.4% and 19.4%.

  4. The link between employee attitudes and employee effectiveness: Data matrix of meta-analytic estimates based on 1161 unique correlations

    Directory of Open Access Journals (Sweden)

    Michael M. Mackay

    2016-09-01

    Full Text Available This article offers a correlation matrix of meta-analytic estimates between various employee job attitudes (i.e., Employee engagement, job satisfaction, job involvement, and organizational commitment and indicators of employee effectiveness (i.e., Focal performance, contextual performance, turnover intention, and absenteeism. The meta-analytic correlations in the matrix are based on over 1100 individual studies representing over 340,000 employees. Data was collected worldwide via employee self-report surveys. Structural path analyses based on the matrix, and the interpretation of the data, can be found in “Investigating the incremental validity of employee engagement in the prediction of employee effectiveness: a meta-analytic path analysis” (Mackay et al., 2016 [1].

  5. Detonation Velocity-Diameter Relation in Gelled Explosive with Inert Inclusions

    Science.gov (United States)

    Higgins, Andrew; Loiseau, Jason; Mi, Xiaocheng

    2017-06-01

    The detonation velocity is measured in a gelled explosive that has been sensitized via the addition of glass microballoons (GMBs) and additionally diluted via the inclusion of large scale (300-700 micron) inert inclusions. The base explosive is nitromethane that has been gelled via the addition of poly(methyl methacrylate) and then sensitized via hot-spot inducing glass microballoons. Inert inclusions (e.g., glass, steel beads) are then added to the explosive to make a heterogeneous explosive with heterogeneities that are at a scale disparate from those of the microballoons. This system has the potential to be a synthetic explosive that can be tuned to have the properties of more complex commercial blasting agents. The velocity-diameter relation is studied using weak confinement (polyvinyl chloride) and time-of-arrival gages. The results are also used to further explore the phenomenon of anomalous scaling between axisymmetric charges (cylinders) and two-dimensional (slab) charges.

  6. Experimental Study of Matrix Permeability of Gas Shale: An Application to CO2-Based Shale Fracturing

    Directory of Open Access Journals (Sweden)

    Chengpeng Zhang

    2018-03-01

    Full Text Available Because the limitations of water-based fracturing fluids restrict their fracturing efficiency and scope of application, liquid CO2 is regarded as a promising substitute, owing to its unique characteristics, including its greater environmental friendliness, shorter clean-up time, greater adsorption capacity than CH4 and less formation damage. Conversely, the disadvantage of high leak-off rate of CO2 fracturing due to its very low viscosity determines its applicability in gas shales with ultra-low permeability, accurate measurement of shale permeability to CO2 is therefore crucial to evaluate the appropriate injection rate and total consumption of CO2. The main purpose of this study is to accurately measure shale permeability to CO2 flow during hydraulic fracturing, and to compare the leak-off of CO2 and water fracturing. A series of permeability tests was conducted on cylindrical shale samples 38 mm in diameter and 19 mm long using water, CO2 in different phases and N2 considering multiple influencing factors. According to the experimental results, the apparent permeability of shale matrix to gaseous CO2 or N2 is greatly over-estimated compared with intrinsic permeability or that of liquid CO2 due to the Klinkenberg effect. This phenomenon explains that the permeability values measured under steady-state conditions are much higher than those under transient conditions. Supercritical CO2 with higher molecular kinetic energy has slightly higher permeability than liquid CO2. The leak-off rate of CO2 is an order of magnitude higher than that of water under the same injection conditions due to its lower viscosity. The significant decrease of shale permeability to gas after water flooding is due to the water block effect, and much longer clean-up time and deep water imbibition depth greatly impede the gas transport from the shale matrix to the created fractures. Therefore, it is necessary to substitute water-based fracturing fluids with liquid or super

  7. Beyond "Inert" Ideas to Teaching General Chemistry from Rich Contexts: Visualizing the Chemistry of Climate Change (VC3)

    Science.gov (United States)

    Mahaffy, Peter G.; Holme, Thomas A.; Martin-Visscher, Leah; Martin, Brian E.; Versprille, Ashley; Kirchhoff, Mary; McKenzie, Lallie; Town, Marcy

    2017-01-01

    As one approach to moving beyond transmitting "inert" ideas to chemistry students, we use the term "teaching from rich contexts" to describe implementations of case studies or context-based learning based on systems thinking that provide deep and rich opportunities for learning crosscutting concepts through contexts. This…

  8. Highly scalable ZIF-based mixed-matrix hollow fiber membranes for advanced hydrocarbon separations

    KAUST Repository

    Zhang, Chen

    2014-05-29

    ZIF-8/6FDA-DAM, a proven mixed-matrix material that demonstrated remarkably enhanced C3H6/C3H8 selectivity in dense film geometry, was extended to scalable hollow fiber geometry in the current work. We successfully formed dual-layer ZIF-8/6FDA-DAM mixed-matrix hollow fiber membranes with ZIF-8 nanoparticle loading up to 30 wt % using the conventional dry-jet/wet-quench fiber spinning technique. The mixed-matrix hollow fibers showed significantly enhanced C3H6/C3H8 selectivity that was consistent with mixed-matrix dense films. Critical variables controlling successful formation of mixed-matrix hollow fiber membranes with desirable morphology and attractive transport properties were discussed. Furthermore, the effects of coating materials on selectivity recovery of partially defective fibers were investigated. To our best knowledge, this is the first article reporting successful formation of high-loading mixed-matrix hollow fiber membranes with significantly enhanced selectivity for separation of condensable olefin/paraffin mixtures. Therefore, it represents a major step in the research area of advanced mixed-matrix membranes. © 2014 American Institute of Chemical Engineers.

  9. The two faces of Eve: gaseous anaesthesia and inert gas narcosis.

    Science.gov (United States)

    Smith, Cameron R; Spiess, Bruce D

    2010-06-01

    Gaseous anaesthesia has been a great boon for medicine. These drugs form a foundation from which modern surgery has sprung, yet their mechanism(s) of actions remains poorly understood. Inert gas narcosis is a limitation of deep sea diving, and its mechanisms also remain poorly understood. In this review article we summarise what is known about the mechanisms of both gaseous anaesthesia and inert gas narcosis, including both lipid-based biophysical models and protein-based biochemical models, as well as explore some striking similarities between the two. These two phenomena may, in reality, be gradations of the same underlying mechanism. Recent findings include biochemical evidence suggesting that both gaseous anaesthesia and inert gas narcosis may be mediated by the occupation of minute spaces within the structure of many biologically important proteins, impairing their ability to undergo conformational changes and biological actions. This is exemplified by exploring the effects of the noble gas xenon, which can behave as either a narcotic gas or gaseous anaesthetic, depending on the partial pressure in which it is present.

  10. Technical basis for storage of Zircaloy-clad spent fuel in inert gases

    International Nuclear Information System (INIS)

    Johnson, A.B. Jr.; Gilbert, E.R.

    1983-09-01

    The technical bases to establish safe conditions for dry storage of Zircaloy-clad fuel are summarized. Dry storage of fuel with zirconium alloy cladding has been licensed in Canada, the Federal Republic of Germany, and Switzerland. Dry storage demonstrations, hot cell tests, and modeling have been conducted using Zircaloy-clad fuel. The demonstrations have included irradiated boiling water reactor, pressurized heavy-water reactor, and pressurized water reactor fuel assemblies. Irradiated fuel has been emplaced in and retrieved from metal casks, dry wells, silos, and a vault. Dry storage tests and demonstrations have involved about 15,000 fuel rods, and about 5600 rods have been monitored during dry storage in inert gases with maximum cladding temperatures ranging from 50 to 570 0 C. Although some tests and demonstrations are still in progress, there is currently no evidence that any rods exposed to inert gases have failed (one PWR rod exposed to an air cover gas failed at about 270 0 C). Based on this favorable experience, it is concluded that there is sufficient information on fuel rod behavior, storage conditions, and potential cladding failure mechanisms to support licensing of dry storage in the US. This licensing position includes a requirement for inert cover gases and a maximum cladding temperature guideline of 380 0 C for Zircaloy-clad fuel. Using an inert cover gas assures that even if fuel with cladding defects were placed in dry storage, or if defects develop during storage, the defects would not propagate. Tests and demonstrations involving Zircaloy-clad rods and assemblies with maximum cladding temperatures above 400 0 C are in progress. When the results from these tests have been evaluated, the viability of higher temperature limits should be examined. Acceptable conditions for storage in air and dry storage of consolidated fuel are issues yet to be resolved

  11. Technical basis for storage of Zircaloy-clad spent fuel in inert gases

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, A.B. Jr.; Gilbert, E.R.

    1983-09-01

    This report summarizes the technical bases to establish safe conditions for dry storage of Zircaloy-clad fuel. Dry storage of fuel with zirconium alloy cladding has been licensed in Canada, the Federal Republic of Germany, and Switzerland. In addition, dry storage demonstrations, hot cell tests, and modeling have been conducted using Zircaloy-clad fuel. The demonstrations have included irradiated boiling water reactor, pressurized heavy-water reactor, and pressurized water reactor (PWR) fuel assemblies. Irradiated fuel has been emplaced in and retrieved from metal casks, dry wells, silos, and a vault. Dry storage tests and demonstrations have involved {similar_to}5,000 fuel rods, and {similar_to}600 rods have been monitored during dry storage in inert gases with maximum cladding temperatures ranging from 50 to 570{sup 0}C. Although some tests and demonstrations are still in progress, there is currently no evidence that any rods exposed to inert gases have failed (one PWR rod exposed to an air cover gas failed at {similar_to}70{sup 0}C). Based on this favorable experience, it is concluded that there is sufficient information on fuel rod behavior, storage conditions, and potential cladding failure mechanisms to support licensing of dry storage in the United States. This licensing position includes a requirement for inert cover gases and a maximum cladding temperature guideline of 380{sup 0}C for Zircaloy-clad fuel. Using an inert cover gas assures that even if fuel with cladding defects were placed in dry storage, or if defects develop during storage, the defects would not propagate. Tests and demonstrations involving Zircaloy-clad rods and assemblies with maximum cladding temperatures above 400{sup 0}C are in progress. When the results from these tests have been evaluated, the viability of higher temperature limits should be examined. Acceptable conditions for storage in air and dry storage of consolidated fuel are issues yet to be resolved.

  12. Disturbance Observer-Based Simple Nonlinearity Compensation for Matrix Converter Drives

    Directory of Open Access Journals (Sweden)

    Kyo-Beum Lee

    2009-01-01

    Full Text Available This paper presents a new method to compensate the nonlinearity for matrix converter drives using disturbance observer. The nonlinearity of matrix converter drives such as commutation delay, turn-on and turn-off time of switching device, and on-state switching device voltage drop is modeled by disturbance observer and compensated. The proposed method does not need any additional hardware and offline experimental measurements. The proposed compensation method is applied for high-performance induction motor drives using a 3 kW matrix converter system without a speed sensor. Simulation and experimental results show that the proposed method using disturbance observer provides good compensating characteristics.

  13. Health monitoring of Ceramic Matrix Composites from waveform-based analysis of Acoustic Emission

    Directory of Open Access Journals (Sweden)

    Maillet Emmanuel

    2015-01-01

    Full Text Available Ceramic Matrix Composites (CMCs are anticipated for use in the hot section of aircraft engines. Their implementation requires the understanding of the various damage modes that are involved and their relation to life expectancy. Acoustic Emission (AE has been shown to be an efficient technique for monitoring damage evolution in CMCs. However, only a waveform-based analysis of AE can offer the possibility to validate and precisely examine the recorded AE data with a view to damage localization and identification. The present work fully integrates wave initiation, propagation and acquisition in the analysis of Acoustic Emission waveforms recorded at various sensors, therefore providing more reliable information to assess the relation between Acoustic Emission and damage modes. The procedure allows selecting AE events originating from damage, accurate determination of their location as well as the characterization of effects of propagation on the recorded waveforms. This approach was developed using AE data recorded during tensile tests on carbon/carbon composites. It was then applied to melt-infiltrated SiC/SiC composites.

  14. Multidimensional entropic uncertainty relation based on a commutator matrix in position and momentum spaces

    Science.gov (United States)

    Hertz, Anaelle; Vanbever, Luc; Cerf, Nicolas J.

    2018-01-01

    The uncertainty relation for continuous variables due to Byałinicki-Birula and Mycielski [I. Białynicki-Birula and J. Mycielski, Commun. Math. Phys. 44, 129 (1975), 10.1007/BF01608825] expresses the complementarity between two n -tuples of canonically conjugate variables (x1,x2,...,xn) and (p1,p2,...,pn) in terms of Shannon differential entropy. Here we consider the generalization to variables that are not canonically conjugate and derive an entropic uncertainty relation expressing the balance between any two n -variable Gaussian projective measurements. The bound on entropies is expressed in terms of the determinant of a matrix of commutators between the measured variables. This uncertainty relation also captures the complementarity between any two incompatible linear canonical transforms, the bound being written in terms of the corresponding symplectic matrices in phase space. Finally, we extend this uncertainty relation to Rényi entropies and also prove a covariance-based uncertainty relation which generalizes the Robertson relation.

  15. Response matrix Monte Carlo based on a general geometry local calculation for electron transport

    International Nuclear Information System (INIS)

    Ballinger, C.T.; Rathkopf, J.A.; Martin, W.R.

    1991-01-01

    A Response Matrix Monte Carlo (RMMC) method has been developed for solving electron transport problems. This method was born of the need to have a reliable, computationally efficient transport method for low energy electrons (below a few hundred keV) in all materials. Today, condensed history methods are used which reduce the computation time by modeling the combined effect of many collisions but fail at low energy because of the assumptions required to characterize the electron scattering. Analog Monte Carlo simulations are prohibitively expensive since electrons undergo coulombic scattering with little state change after a collision. The RMMC method attempts to combine the accuracy of an analog Monte Carlo simulation with the speed of the condensed history methods. Like condensed history, the RMMC method uses probability distributions functions (PDFs) to describe the energy and direction of the electron after several collisions. However, unlike the condensed history method the PDFs are based on an analog Monte Carlo simulation over a small region. Condensed history theories require assumptions about the electron scattering to derive the PDFs for direction and energy. Thus the RMMC method samples from PDFs which more accurately represent the electron random walk. Results show good agreement between the RMMC method and analog Monte Carlo. 13 refs., 8 figs

  16. A fault diagnosis method based on signed directed graph and matrix for nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yong-Kuo, E-mail: LYK08@126.com [Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin 150001 (China); Wu, Guo-Hua [Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin 150001 (China); Institute of Nuclear Energy Technology, Tsinghua University, Beijing 100084 (China); Xie, Chun-Li [Traffic College, Northeast Forestry University, Harbin, 150040 (China); Duan, Zhi-Yong; Peng, Min-Jun; Li, Meng-Kun [Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin 150001 (China)

    2016-02-15

    Highlights: • “Rules matrix” is proposed for FDD. • “State matrix” is proposed to solve SDG online inference. • SDG inference and search method are combined for FDD. - Abstract: In order to solve SDG online fault diagnosis and inference, matrix diagnosis and inference methods are proposed for fault detection and diagnosis (FDD). Firstly, “rules matrix” based on SDG model is used for FDD. Secondly, “status matrix” is proposed to achieve SDG online inference. According to different diagnosis results, “status matrix” is applied for the depth-first search and the breadth-first search respectively to find the propagation paths of each fault. Finally, the SDG model of the secondary-loop system in pressurized water reactor (PWR) is built to verify the effectiveness of the proposed method. The simulation experiment results indicate that the “status matrix” used for online inference can be used to find the fault propagation paths and to explain the causes for fault. Therefore, it can be concluded that the proposed method is one of the fault diagnosis for nuclear power plants (NPPs), which can be used to facilitate the development of fault diagnostic system.

  17. Nonnegative Matrix Factorization-Based Spatial-Temporal Clustering for Multiple Sensor Data Streams

    Directory of Open Access Journals (Sweden)

    Di-Hua Sun

    2014-01-01

    Full Text Available Cyber physical systems have grown exponentially and have been attracting a lot of attention over the last few years. To retrieve and mine the useful information from massive amounts of sensor data streams with spatial, temporal, and other multidimensional information has become an active research area. Moreover, recent research has shown that clusters of streams change with a comprehensive spatial-temporal viewpoint in real applications. In this paper, we propose a spatial-temporal clustering algorithm (STClu based on nonnegative matrix trifactorization by utilizing time-series observational data streams and geospatial relationship for clustering multiple sensor data streams. Instead of directly clustering multiple data streams periodically, STClu incorporates the spatial relationship between two sensors in proximity and integrates the historical information into consideration. Furthermore, we develop an iterative updating optimization algorithm STClu. The effectiveness and efficiency of the algorithm STClu are both demonstrated in experiments on real and synthetic data sets. The results show that the proposed STClu algorithm outperforms existing methods for clustering sensor data streams.

  18. Research on Improved Control Strategy for STATCOM Based on Virtual Matrix Method

    Directory of Open Access Journals (Sweden)

    Wang Xudong

    2016-01-01

    Full Text Available Fast and accurate detection of reactive current is the precondition for the realization of static synchronous compensator (STATCOM reactive power compensation and harmonic suppression. Aiming at deviation and delay of the traditional reactive current detection algorithm with phase-locked loop (PLL and low-pass filter (LPF of STATCOM, a novel improved reactive current detection algorithm without PLL is proposed, in which the virtual matrix (VM is built to replace the original PLL, and improved current average value filter is used to realize the function of LPF, so as to improve the real-time performance and robustness of reactive current detection. The realization process of VM detection method is derived in this paper, and improved control strategy for STATCOM is designed based on the VM detection method. Simulation analysis of the proposed detection algorithm and control strategy is conducted in Matlab platform so as to verify the correctness and effectiveness of the control strategy. The VM detection has the advantages of simple structure, fast response and easy for digital realization, which provides reference for the improvement of reactive power compensation precision for STATCOM.

  19. Antimicrobial thin films based on ayurvedic plants extracts embedded in a bioactive glass matrix

    Science.gov (United States)

    Floroian, L.; Ristoscu, C.; Candiani, G.; Pastori, N.; Moscatelli, M.; Mihailescu, N.; Negut, I.; Badea, M.; Gilca, M.; Chiesa, R.; Mihailescu, I. N.

    2017-09-01

    Ayurvedic medicine is one of the oldest medical systems. It is an example of a coherent traditional system which has a time-tested and precise algorithm for medicinal plant selection, based on several ethnopharmacophore descriptors which knowledge endows the user to adequately choose the optimal plant for the treatment of certain pathology. This work aims for linking traditional knowledge with biomedical science by using traditional ayurvedic plants extracts with antimicrobial effect in form of thin films for implant protection. We report on the transfer of novel composites from bioactive glass mixed with antimicrobial plants extracts and polymer by matrix-assisted pulsed laser evaporation into uniform thin layers onto stainless steel implant-like surfaces. The comprehensive characterization of the deposited films was performed by complementary analyses: Fourier transformed infrared spectroscopy, glow discharge optical emission spectroscopy, scanning electron microscopy, atomic force microscopy, electrochemical impedance spectroscopy, UV-VIS absorption spectroscopy and antimicrobial tests. The results emphasize upon the multifunctionality of these coatings which allow to halt the leakage of metal and metal oxides into the biological fluids and eventually to inner organs (by polymer use), to speed up the osseointegration (due to the bioactive glass use), to exert antimicrobial effects (by ayurvedic plants extracts use) and to decrease the implant price (by cheaper stainless steel use).

  20. Probing matrix and tumor mechanics with in situ calibrated optical trap based active microrheology

    Science.gov (United States)

    Staunton, Jack Rory; Vieira, Wilfred; Tanner, Kandice; Tissue Morphodynamics Unit Team

    Aberrant extracellular matrix deposition and vascularization, concomitant with proliferation and phenotypic changes undergone by cancer cells, alter mechanical properties in the tumor microenvironment during cancer progression. Tumor mechanics conversely influence progression, and the identification of physical biomarkers promise improved diagnostic and prognostic power. Optical trap based active microrheology enables measurement of forces up to 0.5 mm within a sample, allowing interrogation of in vitro biomaterials, ex vivo tissue sections, and small organisms in vivo. We fabricated collagen I hydrogels exhibiting distinct structural properties by tuning polymerization temperature Tp, and measured their shear storage and loss moduli at frequencies 1-15k Hz at multiple amplitudes. Lower Tp gels, with larger pore size but thicker, longer fibers, were stiffer than higher Tp gels; decreasing strain increased loss moduli and decreased storage moduli at low frequencies. We subcutanously injected probes with metastatic murine melanoma cells into mice. The excised tumors displayed storage and loss moduli 40 Pa and 10 Pa at 1 Hz, increasing to 500 Pa and 1 kPa at 15 kHz, respectively.

  1. Low-rank and sparse matrix decomposition-based anomaly detection for hyperspectral imagery

    Science.gov (United States)

    Sun, Weiwei; Liu, Chun; Li, Jialin; Lai, Yenming Mark; Li, Weiyue

    2014-01-01

    A low-rank and sparse matrix decomposition (LRaSMD) detector has been proposed to detect anomalies in hyperspectral imagery (HSI). The detector assumes background images are low-rank while anomalies are gross errors that are sparsely distributed throughout the image scene. By solving a constrained convex optimization problem, the LRaSMD detector separates the anomalies from the background. This protects the background model from corruption. An anomaly value for each pixel is calculated using the Euclidean distance, and anomalies are determined by thresholding the anomaly value. Four groups of experiments on three widely used HSI datasets are designed to completely analyze the performances of the new detector. Experimental results show that the LRaSMD detector outperforms the global Reed-Xiaoli (GRX), the orthogonal subspace projection-GRX, and the cluster-based detectors. Moreover, the results show that LRaSMD achieves equal or better detection performance than the local support vector data description detector within a shorter computational time.

  2. Attribute Reduction Algorithm Based on Structure Discernibility Matrix in Composite Information Systems

    Directory of Open Access Journals (Sweden)

    Ge Mei-Jun

    2017-01-01

    Full Text Available Attribute reduction, as an important preprocessing step for knowledge acquiring in data mining, is one of the key issues in rough set theory. It can only deal with attributes of a specific type in the information system by using a specific binary relation. However, there may be attributes of multiple different types in information systems in real-life applications. A composite relation is proposed to process attributes of multiple different types simultaneously in composite information systems. In order to solve the time-consuming problem of traditional heuristic attribute reduction algorithms, a novel attribute reduction algorithm based on structure discernibility matrix was proposed in this paper. The proposed algorithms can choose the same attribute reduction as its previous version, but it can be used to accelerate a heuristic process of attribute reduction by avoiding the process of intersection and adopting the forward greedy attribute reduction approach. The theoretical analysis and experimental results with UCI data sets show that the proposed algorithm can accelerate the heuristic process of attribute reduction.

  3. Micro-strain Evolution and Toughening Mechanisms in a Trimodal Al-Based Metal Matrix Composite

    Science.gov (United States)

    Zhang, Yuzheng; Topping, Troy D.; Yang, Hanry; Lavernia, Enrique J.; Schoenung, Julie M.; Nutt, Steven R.

    2015-03-01

    A trimodal metal matrix composite (MMC) based on AA (Al alloy) 5083 (Al-4.4Mg-0.7Mn-0.15Cr wt pct) was synthesized by cryomilling powders followed by compaction of blended powders and ceramic particles using two successive dual mode dynamic forgings. The microstructure consisted of 66.5 vol pct ultrafine grain (UFG) region, 30 vol pct coarse grain (CG) region and 3.5 vol pct reinforcing boron carbide particles. The microstructure imparted high-tensile yield strength (581 MPa) compared to a conventional AA 5083 (242 MPa) and enhanced ductility compared to 100 pct UFG Al MMC. The deformation behavior of the heterogeneous structure and the effects of CG regions on crack propagation were investigated using in situ scanning electron microscopy micro-tensile tests. The micro-strain evolution measured using digital image correlation showed early plastic strain localization in CG regions. Micro-voids due to the strain mismatch at CG/UFG interfaces were responsible for crack initiation. CG region toughening was realized by plasticity-induced crack closure and zone shielding of disconnected micro-cracks. However, these toughening mechanisms did not effectively suppress its brittle behavior. Further optimization of the CG distribution (spacing and morphology) is required to achieve toughness levels required for structural applications.

  4. ABOUT THE INFORMATIZATION MANAGING OF THE PRODUCTION SYSTEM BASED ON THE MATRIX MODEL

    Directory of Open Access Journals (Sweden)

    Aleksandr V. Romanenko

    2016-06-01

    Full Text Available Introduction. The problem of formation and information management systems management of manufacturing system businesses is analyzed in the article. Existing schemes of the Russian economy increased demands for its efficiency. Stability integrative model business entity lifecycle requires a search for solutions based on new technologies in the organization and operation of information management systems. Results. On the basis of the analysis of their importance for sustainability of the entity components of its life cycle conclusions are made about the applicability of the matrix model to the production system management. Contradiction in the application of this management model are solved by separating the information on the basis of the state of product and process state. This division contributes to a better organization of the distribution of responsibility between the profit centers and cost centers. As an indicator of the efficiency of profit centers, it is proposed to use the ratio revenue net from the sale of products to the current value of the planned costs of its production. To assess the effectiveness of cost centers used index that is similar to profitability of fixed assets taking into account the cost of resources utilized by each cost center separately. Discussion and Conclusions. We analyze the relationship between goals management of the production system with the role of profit centers and cost centers. The proposed basis of the formation model information ensures the management of the production system, contributing to improve the quality of managerial decisions in implementing the competitive advantages of business entity.

  5. A fault diagnosis method based on signed directed graph and matrix for nuclear power plants

    International Nuclear Information System (INIS)

    Liu, Yong-Kuo; Wu, Guo-Hua; Xie, Chun-Li; Duan, Zhi-Yong; Peng, Min-Jun; Li, Meng-Kun

    2016-01-01

    Highlights: • “Rules matrix” is proposed for FDD. • “State matrix” is proposed to solve SDG online inference. • SDG inference and search method are combined for FDD. - Abstract: In order to solve SDG online fault diagnosis and inference, matrix diagnosis and inference methods are proposed for fault detection and diagnosis (FDD). Firstly, “rules matrix” based on SDG model is used for FDD. Secondly, “status matrix” is proposed to achieve SDG online inference. According to different diagnosis results, “status matrix” is applied for the depth-first search and the breadth-first search respectively to find the propagation paths of each fault. Finally, the SDG model of the secondary-loop system in pressurized water reactor (PWR) is built to verify the effectiveness of the proposed method. The simulation experiment results indicate that the “status matrix” used for online inference can be used to find the fault propagation paths and to explain the causes for fault. Therefore, it can be concluded that the proposed method is one of the fault diagnosis for nuclear power plants (NPPs), which can be used to facilitate the development of fault diagnostic system.

  6. Rotation Matrix Method Based on Ambiguity Function for GNSS Attitude Determination

    Directory of Open Access Journals (Sweden)

    Yingdong Yang

    2016-06-01

    Full Text Available Global navigation satellite systems (GNSS are well suited for attitude determination. In this study, we use the rotation matrix method to resolve the attitude angle. This method achieves better performance in reducing computational complexity and selecting satellites. The condition of the baseline length is combined with the ambiguity function method (AFM to search for integer ambiguity, and it is validated in reducing the span of candidates. The noise error is always the key factor to the success rate. It is closely related to the satellite geometry model. In contrast to the AFM, the LAMBDA (Least-squares AMBiguity Decorrelation Adjustment method gets better results in solving the relationship of the geometric model and the noise error. Although the AFM is more flexible, it is lack of analysis on this aspect. In this study, the influence of the satellite geometry model on the success rate is analyzed in detail. The computation error and the noise error are effectively treated. Not only is the flexibility of the AFM inherited, but the success rate is also increased. An experiment is conducted in a selected campus, and the performance is proved to be effective. Our results are based on simulated and real-time GNSS data and are applied on single-frequency processing, which is known as one of the challenging case of GNSS attitude determination.

  7. Rotation Matrix Method Based on Ambiguity Function for GNSS Attitude Determination.

    Science.gov (United States)

    Yang, Yingdong; Mao, Xuchu; Tian, Weifeng

    2016-06-08

    Global navigation satellite systems (GNSS) are well suited for attitude determination. In this study, we use the rotation matrix method to resolve the attitude angle. This method achieves better performance in reducing computational complexity and selecting satellites. The condition of the baseline length is combined with the ambiguity function method (AFM) to search for integer ambiguity, and it is validated in reducing the span of candidates. The noise error is always the key factor to the success rate. It is closely related to the satellite geometry model. In contrast to the AFM, the LAMBDA (Least-squares AMBiguity Decorrelation Adjustment) method gets better results in solving the relationship of the geometric model and the noise error. Although the AFM is more flexible, it is lack of analysis on this aspect. In this study, the influence of the satellite geometry model on the success rate is analyzed in detail. The computation error and the noise error are effectively treated. Not only is the flexibility of the AFM inherited, but the success rate is also increased. An experiment is conducted in a selected campus, and the performance is proved to be effective. Our results are based on simulated and real-time GNSS data and are applied on single-frequency processing, which is known as one of the challenging case of GNSS attitude determination.

  8. Coordinated Control for Flywheel Energy Storage Matrix Systems for Wind Farm Based on Charging/Discharging Ratio Consensus Algorithms

    DEFF Research Database (Denmark)

    Cao, Qian; Song, Y. D.; Guerrero, Josep M.

    2016-01-01

    This paper proposes a distributed algorithm for coordination of flywheel energy storage matrix system (FESMS) cooperated with wind farm. A simple and distributed ratio consensus algorithm is proposed to solve FESMS dispatch problem. The algorithm is based on average consensus for both undirected...

  9. The improved Apriori algorithm based on matrix pruning and weight analysis

    Science.gov (United States)

    Lang, Zhenhong

    2018-04-01

    This paper uses the matrix compression algorithm and weight analysis algorithm for reference and proposes an improved matrix pruning and weight analysis Apriori algorithm. After the transactional database is scanned for only once, the algorithm will construct the boolean transaction matrix. Through the calculation of one figure in the rows and columns of the matrix, the infrequent item set is pruned, and a new candidate item set is formed. Then, the item's weight and the transaction's weight as well as the weight support for items are calculated, thus the frequent item sets are gained. The experimental result shows that the improved Apriori algorithm not only reduces the number of repeated scans of the database, but also improves the efficiency of data correlation mining.

  10. Comparative evaluation of tungsten inert gas and laser beam ...

    Indian Academy of Sciences (India)

    In this study, the bead-on-plate welds were made on AA5083-H321 alloy plates using both tungsten inert gas (TIG) welding and laser beam (LB) welding processes to study the enhancement of mechanical properties such as weld yield strength and hardness. The low heat input of laser beam welding effectively reduced the ...

  11. An investigation of the microstructures and properties of metal inert ...

    Indian Academy of Sciences (India)

    Friction stir welding; metal inert gas welding; aluminum alloy 5083; ... alloys. Recently, friction stir welding (FSW) technique has overcome many problems encoun- tered in the conventional welding of aluminum alloys as it is a ... considered as an important structural material with a high degree of corrosion resistance and.

  12. effects of metal inert gas welding parameters on some mechanical

    African Journals Online (AJOL)

    HOD

    Surface corrosion deposit composition was analyzed with the SEM paired with energy dispersive spectrometer (EDS) to ascertain microstructural behavior of the material. Keywords- MIG, Mechanical Destructive tests, Current, Speed, ASS, SEM, HCl. 1. INTRODUCTION. Metal Inert Gas (MIG) welding is a process that has ...

  13. An investigation of the microstructures and properties of metal inert ...

    Indian Academy of Sciences (India)

    Abstract. Two different types of welds, Metal Inert Gas (MIG) and Friction Stir. Welding (FSW), have been used to weld aluminum alloy 5083. The microstructure of the welds, including the nugget zone and heat affected zone, has been compared in these two methods using optical microscopy. The mechanical properties of ...

  14. 46 CFR 153.500 - Inert gas systems.

    Science.gov (United States)

    2010-10-01

    ...; (b) Has a pressure control system that: (1) Prevents the inert gas system from raising the cargo tank pressure to more than the relief valve setting; and (2) Maintains at least a 3.5 kPa gauge (approx. 0.5... BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Special...

  15. Inert Electrodes Program fiscal year 1988 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Strachan, D.M.; Marschman, S.C.; Davis, N.C.; Friley, J.R.; Schilling, C.H.

    1989-10-01

    The Inert Electrodes Program, being conducted by Pacific Northwest Laboratory (PNL), involves improving the Hall-Heroult cells used by the Aluminum Industry for the electrochemical production of aluminum. The PNL research centers on developing more energy efficient, longer-lasting anodes and cathodes and ancillary equipment. Major accomplishments for Fiscal Year 1988 are summarized below. 14 refs., 56 figs., 9 tabs.

  16. The effect of dietary protein degradability and rumen inert fat ...

    African Journals Online (AJOL)

    Unknown

    A study was undertaken to investigate the effect of dietary protein degradability and supplemental rumen-inert fats on body mass gain, feed intake and feed conversion ratios in veal calves, as well as digestibility coefficients, carcass masses and meat characteristics. Results on meat characteristics and fatty acid profiles are, ...

  17. The Influence of Suspended Inert Solid Particles on Zinc Corrosion

    DEFF Research Database (Denmark)

    Bech-Nielsen, Gregers

    1996-01-01

    The rate of corrosion of electroplated zinc in near-neutral chloride solutions can be lowered by as much as 75% by adding fine, inert particles of substances such as MnO2, Fe3O4, SiC and TiN to the well-stirred solution. Spreading of local areas of etching is also stopped. Copyright (C) 1996...

  18. 33 CFR 157.164 - Use of inert gas system.

    Science.gov (United States)

    2010-07-01

    ...) POLLUTION RULES FOR THE PROTECTION OF THE MARINE ENVIRONMENT RELATING TO TANK VESSELS CARRYING OIL IN BULK... oxygen content of 8 percent or less by volume. (ii) A positive atmospheric pressure. (5) During COW... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Use of inert gas system. 157.164...

  19. Comparative evaluation of tungsten inert gas and laser beam ...

    Indian Academy of Sciences (India)

    Abstract. In this study, the bead-on-plate welds were made on AA5083-H321 alloy plates using both tungsten inert gas (TIG) welding and laser beam (LB) welding pro- cesses to study the enhancement of mechanical properties such as weld yield strength and hardness. The low heat input of laser beam welding effectively ...

  20. A H2O2 Biosensor Based on Immobilization of HorseradishPeroxidase in a Gelatine Network Matrix

    Directory of Open Access Journals (Sweden)

    Jun-Jie Zhu

    2005-05-01

    Full Text Available A simple and promising H2O2 biosensor has been developed by successfulentrapment of horseradish peroxidase (HRP in a gelatine matrix which was cross-linkedwith formaldehyde. The large microscopic surface area and porous morphology of thegelatine matrix lead to high enzyme loading and the enzyme entrapped in this matrix canretain its bioactivity. This biosensor exhibited a fast amperometric response to hydrogenperoxide (H2O2. The linear range for H2O2 determination was from 2.5×10-5 to2.5×10-3 M, with a detection limit of 2.0×10-6 M based on S / N = 3. This biosensorpossessed very good reproducibility.

  1. Effects of radiative heat transfer on the turbulence structure in inert and reacting mixing layers

    International Nuclear Information System (INIS)

    Ghosh, Somnath; Friedrich, Rainer

    2015-01-01

    We use large-eddy simulation to study the interaction between turbulence and radiative heat transfer in low-speed inert and reacting plane temporal mixing layers. An explicit filtering scheme based on approximate deconvolution is applied to treat the closure problem arising from quadratic nonlinearities of the filtered transport equations. In the reacting case, the working fluid is a mixture of ideal gases where the low-speed stream consists of hydrogen and nitrogen and the high-speed stream consists of oxygen and nitrogen. Both streams are premixed in a way that the free-stream densities are the same and the stoichiometric mixture fraction is 0.3. The filtered heat release term is modelled using equilibrium chemistry. In the inert case, the low-speed stream consists of nitrogen at a temperature of 1000 K and the highspeed stream is pure water vapour of 2000 K, when radiation is turned off. Simulations assuming the gas mixtures as gray gases with artificially increased Planck mean absorption coefficients are performed in which the large-eddy simulation code and the radiation code PRISSMA are fully coupled. In both cases, radiative heat transfer is found to clearly affect fluctuations of thermodynamic variables, Reynolds stresses, and Reynolds stress budget terms like pressure-strain correlations. Source terms in the transport equation for the variance of temperature are used to explain the decrease of this variance in the reacting case and its increase in the inert case

  2. Effects of radiative heat transfer on the turbulence structure in inert and reacting mixing layers

    Science.gov (United States)

    Ghosh, Somnath; Friedrich, Rainer

    2015-05-01

    We use large-eddy simulation to study the interaction between turbulence and radiative heat transfer in low-speed inert and reacting plane temporal mixing layers. An explicit filtering scheme based on approximate deconvolution is applied to treat the closure problem arising from quadratic nonlinearities of the filtered transport equations. In the reacting case, the working fluid is a mixture of ideal gases where the low-speed stream consists of hydrogen and nitrogen and the high-speed stream consists of oxygen and nitrogen. Both streams are premixed in a way that the free-stream densities are the same and the stoichiometric mixture fraction is 0.3. The filtered heat release term is modelled using equilibrium chemistry. In the inert case, the low-speed stream consists of nitrogen at a temperature of 1000 K and the highspeed stream is pure water vapour of 2000 K, when radiation is turned off. Simulations assuming the gas mixtures as gray gases with artificially increased Planck mean absorption coefficients are performed in which the large-eddy simulation code and the radiation code PRISSMA are fully coupled. In both cases, radiative heat transfer is found to clearly affect fluctuations of thermodynamic variables, Reynolds stresses, and Reynolds stress budget terms like pressure-strain correlations. Source terms in the transport equation for the variance of temperature are used to explain the decrease of this variance in the reacting case and its increase in the inert case.

  3. Origins and Evolution of Inorganic-Based and MOF-Based Mixed-Matrix Membranes for Gas Separations

    Directory of Open Access Journals (Sweden)

    Edson V. Perez

    2016-09-01

    Full Text Available Gas separation for industrial, energy, and environmental applications requires low energy consumption and small footprint technology to minimize operating and capital costs for the processing of large volumes of gases. Among the separation methods currently being used, like distillation, amine scrubbing, and pressure and temperature swing adsorption, membrane-based gas separation has the potential to meet these demands. The key component, the membrane, must then be engineered to allow for high gas flux, high selectivity, and chemical and mechanical stability at the operating conditions of feed composition, pressure, and temperature. Among the new type of membranes studied that show promising results are the inorganic-based and the metal-organic framework-based mixed-matrix membranes (MOF-MMMs. A MOF is a unique material that offers the possibility of tuning the porosity of a membrane by introducing diffusional channels and forming a compatible interface with the polymer. This review details the origins of these membranes and their evolution since the first inorganic/polymer and MOF/polymer MMMs were reported in the open literature. The most significant advancements made in terms of materials, properties, and testing conditions are described in a chronological fashion.

  4. Reactive fillers based on SWCNTs functionalized with matrix-based moieties for the production of epoxy composites with superior and tunable properties.

    Science.gov (United States)

    González-Domínguez, Jose M; Martínez-Rubí, Yadienka; Díez-Pascual, Ana M; Ansón-Casaos, A; Gómez-Fatou, Marian; Simard, Benoit; Martínez, M Teresa

    2012-07-20

    Composite materials based on epoxy matrix and single-walled carbon nanotubes (SWCNTs) are able to exhibit outstanding improvements in physical properties when using a tailored covalent functionalization with matrix-based moieties containing terminal amines or epoxide rings. The proper choice of grafted moiety and integration protocol makes it feasible to tune the composite physical properties. At 0.5 wt% SWCNT loading, these composites exhibit up to 65% improvement in storage modulus, 91% improvement in tensile strength, and 65% improvement in toughness. A 15 °C increase in the glass transition temperature relative to the parent matrix was also achieved. This suggests that a highly improved interfacial bonding between matrix and filler, coupled to improved dispersion, are achieved. The degradation temperatures show an upshift in the range of 40-60 °C, which indicates superior thermal performance. Electrical conductivity ranges from ~10(-13) to ~10(-3) S cm(-1), which also shows the possibility of tuning the insulating or conductive behaviour of the composites. The chemical affinity of the functionalization moieties with the matrix and the unchanged molecular structure at the SWCNT/matrix interface are responsible for such improvements.

  5. Accurate and efficient velocity estimation using Transmission matrix formalism based on the domain decomposition method

    Science.gov (United States)

    Wang, Benfeng; Jakobsen, Morten; Wu, Ru-Shan; Lu, Wenkai; Chen, Xiaohong

    2017-03-01

    Full waveform inversion (FWI) has been regarded as an effective tool to build the velocity model for the following pre-stack depth migration. Traditional inversion methods are built on Born approximation and are initial model dependent, while this problem can be avoided by introducing Transmission matrix (T-matrix), because the T-matrix includes all orders of scattering effects. The T-matrix can be estimated from the spatial aperture and frequency bandwidth limited seismic data using linear optimization methods. However the full T-matrix inversion method (FTIM) is always required in order to estimate velocity perturbations, which is very time consuming. The efficiency can be improved using the previously proposed inverse thin-slab propagator (ITSP) method, especially for large scale models. However, the ITSP method is currently designed for smooth media, therefore the estimation results are unsatisfactory when the velocity perturbation is relatively large. In this paper, we propose a domain decomposition method (DDM) to improve the efficiency of the velocity estimation for models with large perturbations, as well as guarantee the estimation accuracy. Numerical examples for smooth Gaussian ball models and a reservoir model with sharp boundaries are performed using the ITSP method, the proposed DDM and the FTIM. The estimated velocity distributions, the relative errors and the elapsed time all demonstrate the validity of the proposed DDM.

  6. Shrinkage covariance matrix approach based on robust trimmed mean in gene sets detection

    Science.gov (United States)

    Karjanto, Suryaefiza; Ramli, Norazan Mohamed; Ghani, Nor Azura Md; Aripin, Rasimah; Yusop, Noorezatty Mohd

    2015-02-01

    Microarray involves of placing an orderly arrangement of thousands of gene sequences in a grid on a suitable surface. The technology has made a novelty discovery since its development and obtained an increasing attention among researchers. The widespread of microarray technology is largely due to its ability to perform simultaneous analysis of thousands of genes in a massively parallel manner in one experiment. Hence, it provides valuable knowledge on gene interaction and function. The microarray data set typically consists of tens of thousands of genes (variables) from just dozens of samples due to various constraints. Therefore, the sample covariance matrix in Hotelling's T2 statistic is not positive definite and become singular, thus it cannot be inverted. In this research, the Hotelling's T2 statistic is combined with a shrinkage approach as an alternative estimation to estimate the covariance matrix to detect significant gene sets. The use of shrinkage covariance matrix overcomes the singularity problem by converting an unbiased to an improved biased estimator of covariance matrix. Robust trimmed mean is integrated into the shrinkage matrix to reduce the influence of outliers and consequently increases its efficiency. The performance of the proposed method is measured using several simulation designs. The results are expected to outperform existing techniques in many tested conditions.

  7. Experimental investigation for graphene and carbon fibre in polymer-based matrix for structural applications

    Directory of Open Access Journals (Sweden)

    Shankar A. Hallad

    2017-06-01

    Full Text Available The present paper investigates the behaviour of a polymer matrix beam reinforced with graphene and carbon fibres at nano and micro level reinforcements, respectively, to study mainly the strength aspects for structural applications. However an attempt has also been made to use a combination of both micro and nano level fillers in both individual and combined forms as reinforcements. The addition of graphene and carbon fibres in the control beams was varied from 0.1 to 0.4% percent by weight of polymer matrix. Dispersion of graphene was carried out using ultrasonic energy. Composite beams were tested under flexural in order to evaluate their mechanical property such as load-deflection criteria. These results were then compared with those obtained from plain polymer beams. The present work also investigates the optimum percentage of graphene and carbon fibres as individual and combination fillers that gave the best results in terms of enhanced mechanical properties and economical aspects as well. Scanning electron microscopy and energy dispersion X-ray spectroscopy was conducted to examine the interfacial surface adhesion between the fillers and the polymer matrix. Reinforcement of polymer beams with graphene alone by weight of the polymer matrix showed enhanced results when compared to carbon fibres alone while the use of combined nano and micro reinforcements showed performance lying in between nano and micro fillers in the polymer. Flexural strength is enhanced by 35% compared to plain control beams when graphene was used as reinforcement fillers in the polymer matrix.

  8. A sensitive glucose biosensor based on Ag@C core–shell matrix

    International Nuclear Information System (INIS)

    Zhou, Xuan; Dai, Xingxin; Li, Jianguo; Long, Yumei; Li, Weifeng; Tu, Yifeng

    2015-01-01

    Nano-Ag particles were coated with colloidal carbon (Ag@C) to improve its biocompatibility and chemical stability for the preparation of biosensor. The core–shell structure was evidenced by transmission electron microscope (TEM) and the Fourier transfer infrared (FTIR) spectra revealed that the carbon shell is rich of function groups such as − OH and − COOH. The as-prepared Ag@C core–shell structure can offer favorable microenvironment for immobilizing glucose oxidase and the direct electrochemistry process of glucose oxidase (GOD) at Ag@C modified glassy carbon electrode (GCE) was realized. The modified electrode exhibited good response to glucose. Under optimum experimental conditions the biosensor linearly responded to glucose concentration in the range of 0.05–2.5 mM, with a detection limit of 0.02 mM (S/N = 3). The apparent Michaelis–Menten constant (K M app ) of the biosensor is calculated to be 1.7 mM, suggesting high enzymatic activity and affinity toward glucose. In addition, the GOD-Ag@C/Nafion/GCE shows good reproducibility and long-term stability. These results suggested that core–shell structured Ag@C is an ideal matrix for the immobilization of the redox enzymes and further the construction of the sensitive enzyme biosensor. - Highlights: • Enhanced direct electrochemistry of GOD was achieved at Ag@C modified electrode. • A novel glucose biosensor based on Ag@C core–shell structure was developed. • The designed GOD-Ag@C/Nafion/GCE biosensor showed favorable analysis properties. • The biosensor is easy to prepare and can be applied for real sample assay

  9. Regulation of human mesenchymal stem cells differentiation into chondrocytes in extracellular matrix-based hydrogel scaffolds.

    Science.gov (United States)

    Du, Mingchun; Liang, Hui; Mou, Chenchen; Li, Xiaoran; Sun, Jie; Zhuang, Yan; Xiao, Zhifeng; Chen, Bing; Dai, Jianwu

    2014-02-01

    To induce human mesenchymal stem cells (hMSCs) to differentiate into chondrocytes in three-dimensional (3D) microenvironments, we developed porous hydrogel scaffolds using the cartilage extracellular matrix (ECM) components of chondroitin sulfate (CS) and collagen (COL). The turbidity and viscosity experiments indicated hydrogel could form through pH-triggered co-precipitation when pH=2-3. Enzyme-linked immunosorbent assay (ELISA) confirmed the hydrogel scaffolds could controllably release growth factors as envisaged. Transforming growth factor-β (TGF-β) was released to stimulate hMSCs differentiation into chondrocytes; and then collagen binding domain-basic fibroblast growth factor (CBD-bFGF) was released to improve the differentiation and preserve the chondrocyte phenotype. In in vitro cell culture experiments, the differentiation processes were compared in different microenvironments: 2D culture in culture plate as control, 3D culture in the fabricated scaffolds without growth factors (CC), the samples with CBD-bFGF (CC-C), the samples with TGF-β (CC-T), the samples with CBD-bFGF/TGF-β (CC-CT). Real-time polymerase chain reaction (RT-PCR) revealed the hMSC marker genes of CD44 and CD105 decreased; at the same time the chondrocyte marker genes of collagen type II and aggrecan increased, especially in the CC-CT sample. Immunostaining results further confirmed the hMSC marker protein of CD 44 disappeared and the chondrocyte marker protein of collagen type II emerged over time in the CC-CT sample. These results imply the ECM-based hydrogel scaffolds with growth factors can supply suitable 3D cell niches for hMSCs differentiation into chondrocytes and the differentiation process can be regulated by the controllably released growth factors. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Influence of the polymer matrix on the efficiency of hybrid solar cells based on silicon nanowires

    International Nuclear Information System (INIS)

    Ben Dkhil, S.; Bourguiga, R.; Davenas, J.; Cornu, D.

    2012-01-01

    Highlights: ► Hybrid solar cells based on silicon nanowires have been fabricated. ► The relation between the morphology of the composite thin films and the charge transfer between the polymer matrices and SiNWs has been examined. ► We have investigated the effect of the polymer matrix on the photovoltaic characteristics. - Abstract: Poly (N-vinylcarbazole) (PVK):SiNWs and poly (2-methoxy, 5-(2-ethyl-hexyloxy)-p-phenyl vinylene) (MEH-PPV):SiNWs bulk-heterojunctions (BHJ) have been elaborated from blends of SiNWs and the polymer in solution from a common solvent. Optical properties of these nanocomposites have been investigated by UV–vis absorption and photoluminescence (PL) spectral measurements. We have studied the charge transfer between SiNWs and the two polymers using the photoluminescence quenching of PVK and MEH-PPV which is a convenient signature of the reduced radiative recombination of the generated charge pairs upon exciton dissociation. We found that PVK and SiNWs constitutes the better donor–acceptor system. In order to understand the difference between PVK:SiNWs or MEH-PPV:SiNWs behaviours, photoluminescence responses were correlated with the topography (SEM) of the thin films. The photovoltaic effect of ITO/PEDOT:PSS/SiNWs:PVK/Al and ITO/PEDOT:PSS/SiNWs:MEH-PPV/Al structures was studied by current–voltage (I–V) measurements in dark and under illumination and interpreted on the basis of the charge transfer differences resulting from the morphologies.

  11. Influence of the polymer matrix on the efficiency of hybrid solar cells based on silicon nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Ben Dkhil, S., E-mail: sadok.bendekhil@gmail.com [Laboratoire Physique des Materiaux: Structures et Proprietes Groupe Physique des Composants et Dispositifs Nanometriques, 7021 Jarzouna, Bizerte (Tunisia); Ingenierie des Materiaux Polymeres: IMP, UMR CNRS 5223, Universite Claude Bernard Lyon 1, 15 boulevard Latarjet, 69622 Villeurbanne (France); Bourguiga, R. [Laboratoire Physique des Materiaux: Structures et Proprietes Groupe Physique des Composants et Dispositifs Nanometriques, 7021 Jarzouna, Bizerte (Tunisia); Davenas, J. [Ingenierie des Materiaux Polymeres: IMP, UMR CNRS 5223, Universite Claude Bernard Lyon 1, 15 boulevard Latarjet, 69622 Villeurbanne (France); Cornu, D. [Institut Europeen des Membranes, UMR CNRS 5635, Ecole Nationale superieure de Chimie, Universite de Montpellier, 1919 route de Mende, 34000 Montpellier (France)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Hybrid solar cells based on silicon nanowires have been fabricated. Black-Right-Pointing-Pointer The relation between the morphology of the composite thin films and the charge transfer between the polymer matrices and SiNWs has been examined. Black-Right-Pointing-Pointer We have investigated the effect of the polymer matrix on the photovoltaic characteristics. - Abstract: Poly (N-vinylcarbazole) (PVK):SiNWs and poly (2-methoxy, 5-(2-ethyl-hexyloxy)-p-phenyl vinylene) (MEH-PPV):SiNWs bulk-heterojunctions (BHJ) have been elaborated from blends of SiNWs and the polymer in solution from a common solvent. Optical properties of these nanocomposites have been investigated by UV-vis absorption and photoluminescence (PL) spectral measurements. We have studied the charge transfer between SiNWs and the two polymers using the photoluminescence quenching of PVK and MEH-PPV which is a convenient signature of the reduced radiative recombination of the generated charge pairs upon exciton dissociation. We found that PVK and SiNWs constitutes the better donor-acceptor system. In order to understand the difference between PVK:SiNWs or MEH-PPV:SiNWs behaviours, photoluminescence responses were correlated with the topography (SEM) of the thin films. The photovoltaic effect of ITO/PEDOT:PSS/SiNWs:PVK/Al and ITO/PEDOT:PSS/SiNWs:MEH-PPV/Al structures was studied by current-voltage (I-V) measurements in dark and under illumination and interpreted on the basis of the charge transfer differences resulting from the morphologies.

  12. Aqueous zymography screening of matrix metalloproteinase activity and inhibition based on colorimetric gold nanoparticles.

    Science.gov (United States)

    Chuang, Yao-Chen; Huang, Wei-Ting; Chiang, Pin-Hsuan; Tang, Meng-Che; Lin, Chih-Sheng

    2012-02-15

    An optical gold nanoparticles (AuNPs)-based method was fabricated for the rapid detection of matrix metalloproteinase (MMP) activity and screening potential MMP inhibitors without sophisticated instruments. The diagnosis platform was composed of AuNPs, particular MMP substrates and 6-mercapto-1-hexanol (MCH). The functionalized AuNPs were subjected to specific MMP digestion, and the MMP found the substrate on AuNPs, such that the AuNPs lost shelter and MCH increased the attraction force between AuNPs. Consequently, AuNPs aggregation and a color change from red to purple with increasing MMP concentration were observed. The surface plasmon resonance (SPR) of the formed AuNPs allowed for the quantitative detection of MMP activity. A sensitive linear correlation existed between the absorbance and the activity of the MMPs, which ranged from 10 ng/mL to 700 ng/mL in NTTC buffer and plasma samples. The proposed colorimetric method could be accomplished in a homogeneous solution with one-step operation in 30 min and has been successfully applied to the determination of particular MMP activity in plasma samples, in which the results are consistent with substrate zymography. This technology may become a simple platform for parallel screening a number of inhibitors and offer an alternative method to studying the efficiency of inhibitors for suppressing MMP activity. The absorbance ratio at 625 nm and 525 nm (A(625)/A(525)) confirmed the efficiency of the inhibitors as observed in substrate zymography. The IC(50) of ONO-4817 and galardin for MMP-1, MMP-2 and MMP-7 determined by the proposed colorimetric method was similar to the results of substrate zymography. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  13. Three-Dimensional-Bioprinted Dopamine-Based Matrix for Promoting Neural Regeneration.

    Science.gov (United States)

    Zhou, Xuan; Cui, Haitao; Nowicki, Margaret; Miao, Shida; Lee, Se-Jun; Masood, Fahed; Harris, Brent T; Zhang, Lijie Grace

    2018-03-14

    Central nerve repair and regeneration remain challenging problems worldwide, largely because of the extremely weak inherent regenerative capacity and accompanying fibrosis of native nerves. Inadequate solutions to the unmet needs for clinical therapeutics encourage the development of novel strategies to promote nerve regeneration. Recently, 3D bioprinting techniques, as one of a set of valuable tissue engineering technologies, have shown great promise toward fabricating complex and customizable artificial tissue scaffolds. Gelatin methacrylate (GelMA) possesses excellent biocompatible and biodegradable properties because it contains many arginine-glycine-aspartic acids (RGD) and matrix metalloproteinase sequences. Dopamine (DA), as an essential neurotransmitter, has proven effective in regulating neuronal development and enhancing neurite outgrowth. In this study, GelMA-DA neural scaffolds with hierarchical structures were 3D-fabricated using our custom-designed stereolithography-based printer. DA was functionalized on GelMA to synthesize a biocompatible printable ink (GelMA-DA) for improving neural differentiation. Additionally, neural stem cells (NSCs) were employed as the primary cell source for these scaffolds because of their ability to terminally differentiate into a variety of cell types including neurons, astrocytes, and oligodendrocytes. The resultant GelMA-DA scaffolds exhibited a highly porous and interconnected 3D environment, which is favorable for supporting NSC growth. Confocal microscopy analysis of neural differentiation demonstrated that a distinct neural network was formed on the GelMA-DA scaffolds. In particular, the most significant improvements were the enhanced neuron gene expression of TUJ1 and MAP2. Overall, our results demonstrated that 3D-printed customizable GelMA-DA scaffolds have a positive role in promoting neural differentiation, which is promising for advancing nerve repair and regeneration in the future.

  14. A sensitive glucose biosensor based on Ag@C core–shell matrix

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xuan; Dai, Xingxin; Li, Jianguo [College of Chemistry, Chemical engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215123 (China); Long, Yumei, E-mail: yumeilong@suda.edu.cn [College of Chemistry, Chemical engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215123 (China); The Key Lab of Health Chemistry and Molecular Diagnosis of Suzhou (China); Li, Weifeng, E-mail: liweifeng@suda.edu.cn [College of Chemistry, Chemical engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215123 (China); Tu, Yifeng [College of Chemistry, Chemical engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215123 (China); The Key Lab of Health Chemistry and Molecular Diagnosis of Suzhou (China)

    2015-04-01

    Nano-Ag particles were coated with colloidal carbon (Ag@C) to improve its biocompatibility and chemical stability for the preparation of biosensor. The core–shell structure was evidenced by transmission electron microscope (TEM) and the Fourier transfer infrared (FTIR) spectra revealed that the carbon shell is rich of function groups such as − OH and − COOH. The as-prepared Ag@C core–shell structure can offer favorable microenvironment for immobilizing glucose oxidase and the direct electrochemistry process of glucose oxidase (GOD) at Ag@C modified glassy carbon electrode (GCE) was realized. The modified electrode exhibited good response to glucose. Under optimum experimental conditions the biosensor linearly responded to glucose concentration in the range of 0.05–2.5 mM, with a detection limit of 0.02 mM (S/N = 3). The apparent Michaelis–Menten constant (K{sub M}{sup app}) of the biosensor is calculated to be 1.7 mM, suggesting high enzymatic activity and affinity toward glucose. In addition, the GOD-Ag@C/Nafion/GCE shows good reproducibility and long-term stability. These results suggested that core–shell structured Ag@C is an ideal matrix for the immobilization of the redox enzymes and further the construction of the sensitive enzyme biosensor. - Highlights: • Enhanced direct electrochemistry of GOD was achieved at Ag@C modified electrode. • A novel glucose biosensor based on Ag@C core–shell structure was developed. • The designed GOD-Ag@C/Nafion/GCE biosensor showed favorable analysis properties. • The biosensor is easy to prepare and can be applied for real sample assay.

  15. Development of a poly(dimethylacrylamide) based matrix material for solid phase high density peptide array synthesis employing a laser based material transfer

    Energy Technology Data Exchange (ETDEWEB)

    Ridder, Barbara [Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Institute of Organic Chemistry (IOC), Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe (Germany); Foertsch, Tobias C. [Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Welle, Alexander [Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Mattes, Daniela S. [Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Institute of Organic Chemistry (IOC), Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe (Germany); Bojnicic-Kninski, Clemens M. von; Loeffler, Felix F.; Nesterov-Mueller, Alexander [Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Meier, Michael A.R., E-mail: m.a.r.meier@kit.edu [Institute of Organic Chemistry (IOC), Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe (Germany); Breitling, Frank, E-mail: frank.breitling@kit.edu [Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2016-12-15

    Highlights: • New matrix material for peptide array synthesis from a ‘solid solvent’. • Resolution was increased with possible spot densities of up to 20.000 spots per cm{sup 2}. • The coupling depth and the effectiveness of washing steps analyzed by ToF-SIMS. • Adaptations and custom changes of the matrix material are possible. - Abstract: Poly(dimethylacrylamide) (PDMA) based matrix materials were developed for laser-based in situ solid phase peptide synthesis to produce high density arrays. In this specific array synthesis approach, amino acid derivatives are embedded into a matrix material, serving as a “solid” solvent material at room temperature. Then, a laser pulse transfers this mixture to the target position on a synthesis slide, where the peptide array is synthesized. Upon heating above the glass transition temperature of the matrix material, it softens, allowing diffusion of the amino acid derivatives to the synthesis surface and serving as a solvent for peptide bond formation. Here, we synthesized PDMA six-arm star polymers, offering the desired matrix material properties, using atom transfer radical polymerization. With the synthesized polymers as matrix material, we structured and synthesized arrays with combinatorial laser transfer. With densities of up to 20,000 peptide spots per cm{sup 2}, the resolution could be increased compared to the commercially available standard matrix material. Time-of-Flight Secondary Ion Mass Spectrometry experiments revealed the penetration behavior of an amino acid derivative into the prepared acceptor synthesis surface and the effectiveness of the washing protocols.

  16. Aesthetic outcomes of acellular dermal matrix in tissue expander/implant-based breast reconstruction.

    Science.gov (United States)

    Forsberg, Clay G; Kelly, David A; Wood, Benjamin C; Mastrangelo, Stephanie L; DeFranzo, Anthony J; Thompson, James T; David, Lisa R; Marks, Malcolm W

    2014-01-01

    Tissue expander and implant-based breast reconstruction after mastectomy is the most common method of breast reconstruction. Modifications of the traditional total submuscular reconstruction (TSR) have been made using acellular dermal matrix (ADM) to create an inferolateral sling and a more natural implant pocket for superior aesthetic results. The objective of this study was to assess aesthetic outcomes when using ADM in breast reconstruction. A retrospective chart review identified all patients who underwent implant-based breast reconstruction from 2005 to 2009 at our institution. Demographic information, complications, reoperations, and aesthetic outcome data were collected for all patients meeting inclusion criteria related to adequate follow-up and postoperative photographs. Five aesthetic outcomes were evaluated for all study patients by 18 blinded evaluators using postoperative photographs. Outcomes were scored on a scale of 1 to 5, with 5 representing the best possible aesthetic score. A total of 122 patients underwent 183 tissue expander-based reconstructions (ADM, n = 58; TSR, n = 125). The infection rate in patients with ADM was 16.2% compared to 5.9% in TSR patients, but this was not statistically significant (P = 0.09). Capsular contracture was more common in TSR patients (23.5%), compared to those with ADM (8.1%), P = 0.048. Aesthetic scores from the attending plastic surgeons were as follows: natural contour (ADM, 3.36; TSR, 3.02; P = 0.0001), symmetry of shape (ADM, 3.57; TSR, 3.27; P = 0.005), symmetry of size (ADM, 3.68; TSR, 3.42; P = 0.002), position on chest wall (ADM, 3.75; TSR, 3.45; P = 0.004), and overall aesthetic appearance (ADM, 3.56; TSR, 3.20; P = 0.0001). For all 5 aesthetic parameters evaluated, the ADM group scored significantly higher than the TSR group by 18 blinded evaluators. These consistent findings suggest that the use of ADM in breast reconstruction does confer a significant advantage in aesthetic outcomes for breast

  17. Quantitative characterization of carbon/carbon composites matrix texture based on image analysis using polarized light microscope.

    Science.gov (United States)

    Li, Yixian; Qi, Lehua; Song, Yongshan; Hou, Xianghui; Li, Hejun

    2015-10-01

    A quantitative characteristic method was proposed for characterizing the matrix texture of carbon/carbon(C/C) composites, which determined the mechanical and physical properties of C/C composites. Based on the cloud theory that was commonly used for uncertain reasoning and the transformation between quantitative and qualitative characterization, so the relationship between the extinction angle and texture types was built by the cloud models for describing the texture of microstructure, moreover, linguistic controllers were established to analyze the matrix texture in accordance with the features of the polarized light microscope (PLM) image. On this basis, the extinction angle could be calculated from the PLM image of the C/C composites. In contrast to the results of measurement, the errors between calculative values and measured values were maintained 1-2° in basically. Meanwhile, the PLM image of C/C composites was segmented by the component, in particular, the matrix with mixed textures was further segmented by the difference of texture. It means that the quantitative characterization of C/C composites matrix based on single PLM image has been realized. © 2015 Wiley Periodicals, Inc.

  18. A Unique Mathematical Derivation of the Fundamental Laws of Nature Based on a New Algebraic-Axiomatic (Matrix Approach ‡

    Directory of Open Access Journals (Sweden)

    Ramin Zahedi

    2017-09-01

    Full Text Available In this article, as a new mathematical approach to origin of the laws of nature, using a new basic algebraic axiomatic (matrix formalism based on the ring theory and Clifford algebras (presented in Section 2, “it is shown that certain mathematical forms of fundamental laws of nature, including laws governing the fundamental forces of nature (represented by a set of two definite classes of general covariant massive field equations, with new matrix formalisms, are derived uniquely from only a very few axioms.” In agreement with the rational Lorentz group, it is also basically assumed that the components of relativistic energy-momentum can only take rational values. In essence, the main scheme of this new mathematical axiomatic approach to the fundamental laws of nature is as follows: First, based on the assumption of the rationality of D-momentum and by linearization (along with a parameterization procedure of the Lorentz invariant energy-momentum quadratic relation, a unique set of Lorentz invariant systems of homogeneous linear equations (with matrix formalisms compatible with certain Clifford and symmetric algebras is derived. Then by an initial quantization (followed by a basic procedure of minimal coupling to space-time geometry of these determined systems of linear equations, a set of two classes of general covariant massive (tensor field equations (with matrix formalisms compatible with certain Clifford, and Weyl algebras is derived uniquely as well.

  19. Multi-Path OD-Matrix Estimation (MPME) based on Stochastic User Equilibrium Traffic Assignment

    DEFF Research Database (Denmark)

    Nielsen, Otto Anker

    1997-01-01

    Most conventional methods for estimating trip matrices from traffic counts assume either that the counts are error-free, determin-istic variables or they use a simplified traffic assignment model. Without these assumptions, the methods often demand prohibitive calculation times. The paper presents...... a matrix-estimation method, 'Multiple Path Matrix Estimation' (MPME), that is able to handle traffic counts with inconsistencies and uncertainties. In addition, the matrix reflects the route choice patterns given by traffic assignment models following the Method of Successive Averages (MSA). Actually...... million inhabitants). In all cases, the method gave lower deviations between traffic counts and estimated traffic than other tested methods. The method converged smoothly within calculation times of a few hours....

  20. Genetic Algorithm and Graph Theory Based Matrix Factorization Method for Online Friend Recommendation

    Directory of Open Access Journals (Sweden)

    Qu Li

    2014-01-01

    Full Text Available Online friend recommendation is a fast developing topic in web mining. In this paper, we used SVD matrix factorization to model user and item feature vector and used stochastic gradient descent to amend parameter and improve accuracy. To tackle cold start problem and data sparsity, we used KNN model to influence user feature vector. At the same time, we used graph theory to partition communities with fairly low time and space complexity. What is more, matrix factorization can combine online and offline recommendation. Experiments showed that the hybrid recommendation algorithm is able to recommend online friends with good accuracy.

  1. Adsorption and desorption of radioactive inert gases in various materials

    International Nuclear Information System (INIS)

    Butkus, D.

    1999-01-01

    Peculiarities of the 85 Kr and 133 Xe adsorption and desorption processes in active carbon and paraffin are considered in the work. During the desorption process, the distribution of 85 Kr and 133 Xe atoms in active carbon particles is uneven: atoms in narrow micropores desorb the last. It is shown that by changing adsorption conditions the presence time of radioactive inert gases in an active carbon can be prolonged. The adsorption and desorption processes change in the adsorbent, which changes its aggregation state: adsorption occurs in a liquid absorbent and desorption - in a solid absorbent. Paraffin is just such an absorbent changing its aggregation state with low energy losses. It has been obtained that 133 Xe accumulates less in liquid paraffin that in an active carbon. The absorption of 85 Kr in paraffin is larger than in an active carbon (at 18-20 degrees Celsius), while desorption is slower. The velocity of radioactive inert gas atom motion in different places of a solid paraffin sample is different - it increases approaching the borders of the sample. Prolongation of the desorption time of radioactive inert gases from adsorbents and adsorbents in many cases is of a practical importance. In this work, it has been shown by model experiments that the intensity of adsorption and desorption processes for the same sorbents can be changed. Desorption intensity changes are related to the distribution of gas atoms on the surface of particles and in micropores. Desorption velocity decreases if inert gas atoms having entered micropores are 'closed' by condensed liquids in the environment. In this case an inert gas atom diffuses within the whole particle volume or through the condensed liquid. Radioactive inert gases 85 Kr and 133 Xe are absorbed not only in liquid paraffin but in solid one as well. Therefore, after a paraffin sample is hermetically closed in a glass dish, 85 Kr (gas) having diffused from this sample is repeatedly absorbed in it. The 85 Kr

  2. Fabrication of targets for transmutation of americium : synthesis of inertial matrix by sol-gel method. Procedure study on the infiltration of a radioactive solutions; Fabricacion de blancos para la transmutacion de americio: sintesis de matrices inertes por el metodo sol-gel. Estudio del procedimiento de infiltracion de disoluciones radiactivas

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Carretero, A. [Universidad Complutense de Madrid (Spain)

    2002-07-01

    Transmutation and incineration are innovative options in the management and disposal of fission products and actinides. nevertheless, the fabrication of targets for transmutation and incineration of actinides and fission products require a reconsideration of conventional processes (mechanical blending) and the development of new procedures compatible with the high activity of these materials. This work presents th R and D of a new fabrication method called INRAM (Infiltration of Radioactive Materials) based on the infiltration of an actinide solution in a porous non radiotoxic material in the form of a pellet (up to 12% An), or beads (up to 40% An) produced by sol-gel. The first method have been used for the fabrication of spinel (MgAl{sub 2}O{sub 4}) targets containing 11% Am, which have been irradiated in HFR-Petten (358.4 full power days). Post-test burn-up calculations showed that at the end of the irradiation the initial Am-241 concentration was reduced to 4%. The fraction of the initial americum atoms that have been fissioned is 28%. The main advantage of the INRAM method is that matrices with low or zero activity can be fabricated and formed into the required shape in an unshielded facility. This method offers other advantages over conventional ones, such as the active wastes are reduced, is easy to automate, adoptable to telemanipulation and dust free, which facilitate operator intervention and minimise radiation exposure to the personal. In addition, the infiltrant needs only be present in liquid form, i. e. it could be transferred directly from the reprocessing plant for fabrication into targets without conversion into-solid form. In order to optimise the infiltration process in depth investigations of all important process parameters, e. g. infiltration kinetics and metal (pu, Am) concentration in the feed solution, and also on extensive study or powder metallurgy parameters for the preparation of high quality fuel pellets with a high density, have been

  3. PUBLIC PERCEPTION ON GOVERNMENT SPENDING IN ACEH: AN ANALYSIS BASED ON MAQASID PERFORMANCE PAIRWISE MATRIX (MPPM

    Directory of Open Access Journals (Sweden)

    Muhammad Dayyan

    2014-12-01

    Full Text Available Governments provide a host of goods and services to their citizens to achieve various socio-economic objectives. Such spending is done through various programs that include social security, education, infrastructure, health and economic. Several conventional approaches for measuring efficiency of government expenditure have been proposed in the literature. Most of these measures are quantitative in nature. For government spending based on Shari’ah oriented public policy (al-Siyasah al-Shar’iyyah, which is value loaded, there is a need for complementary qualitative yardstick to measure whether such spending achieves Maqasid al-Shari’ah. The present study has made use of content analysis to develop a Maqasid Performance Pairwise Matrix (MPPM, as one of the tools of Islamic oriented public policy (al-Siyasah al-Shar’iyyah; to measure the public perception on government expenditure in Aceh in eight areas and the extent to which the expenditure conforms to Maqasid al-Shari’ah. MPPM was used as an instrument to survey 233 respondents in Aceh. The data from the survey were validated analyzed using SPSS version 18.0. The findings from the study are mixed. Government spending in Aceh in Education and health achieved results at the level of Complements (Hajiyat, beyond the basic need (Daruriyat. Whereas in the other six areas, which include economics, public services and housing, government spending is only able to satisfy the basic needs of the Acehnese. The study concludes with recommendations and suggestions for future research. =========================================== Pemerintah menyediakan tempat barang dan jasa untuk warga negara mereka untuk mencapai berbagai tujuan sosial-ekonomi. Seperti pengeluaran, yang dilakukan melalui berbagai program termasuk jaminan sosial, pendidikan infrastruktur, kesehatan dan ekonomi. Beberapa pendekatan konvensional untuk mengukur efisiensi pengeluaran pemerintah telah ada dalam sejumlah literatur

  4. Linear matrix inequality-based nonlinear adaptive robust control with application to unmanned aircraft systems

    Science.gov (United States)

    Kun, David William

    Unmanned aircraft systems (UASs) are gaining popularity in civil and commercial applications as their lightweight on-board computers become more powerful and affordable, their power storage devices improve, and the Federal Aviation Administration addresses the legal and safety concerns of integrating UASs in the national airspace. Consequently, many researchers are pursuing novel methods to control UASs in order to improve their capabilities, dependability, and safety assurance. The nonlinear control approach is a common choice as it offers several benefits for these highly nonlinear aerospace systems (e.g., the quadrotor). First, the controller design is physically intuitive and is derived from well known dynamic equations. Second, the final control law is valid in a larger region of operation, including far from the equilibrium states. And third, the procedure is largely methodical, requiring less expertise with gain tuning, which can be arduous for a novice engineer. Considering these facts, this thesis proposes a nonlinear controller design method that combines the advantages of adaptive robust control (ARC) with the powerful design tools of linear matrix inequalities (LMI). The ARC-LMI controller is designed with a discontinuous projection-based adaptation law, and guarantees a prescribed transient and steady state tracking performance for uncertain systems in the presence of matched disturbances. The norm of the tracking error is bounded by a known function that depends on the controller design parameters in a known form. Furthermore, the LMI-based part of the controller ensures the stability of the system while overcoming polytopic uncertainties, and minimizes the control effort. This can reduce the number of parameters that require adaptation, and helps to avoid control input saturation. These desirable characteristics make the ARC-LMI control algorithm well suited for the quadrotor UAS, which may have unknown parameters and may encounter external

  5. Mixed matrix membranes based on polyamide/montmorillonite for pervaporation of methanol-toluene mixture

    Czech Academy of Sciences Publication Activity Database

    Avagimova, N.; Polotskaya, G.; Saprykina, N.; Toikka, A.; Pientka, Zbyněk

    2013-01-01

    Roč. 48, č. 17 (2013), s. 2513-2523 ISSN 0149-6395 R&D Projects: GA ČR GA104/09/1165 Institutional support: RVO:61389013 Keywords : membranes * pervaporation * mixed matrix Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.200, year: 2013

  6. Wear behaviour of Zr-based in situ bulk metallic glass matrix ...

    Indian Academy of Sciences (India)

    ... wear debris, which exhibited the characteristic of a mild abrasive wear. The improvement of the wear resistance of the composite with the proper amount of β -Zr crystalline phase is attributed to the fact that the β -Zr crystalline phase distributed in the amorphous matrix has some effective load bearing, plastic deformation ...

  7. MIMO-OFDM Chirp Waveform Diversity Design and Implementation Based on Sparse Matrix and Correlation Optimization

    Directory of Open Access Journals (Sweden)

    Wang Wen-qin

    2015-02-01

    Full Text Available The waveforms used in Multiple-Input Multiple-Output (MIMO Synthetic Aperture Radar (SAR should have a large time-bandwidth product and good ambiguity function performance. A scheme to design multiple orthogonal MIMO SAR Orthogonal Frequency Division Multiplexing (OFDM chirp waveforms by combinational sparse matrix and correlation optimization is proposed. First, the problem of MIMO SAR waveform design amounts to the associated design of hopping frequency and amplitudes. Then a iterative exhaustive search algorithm is adopted to optimally design the code matrix with the constraints minimizing the block correlation coefficient of sparse matrix and the sum of cross-correlation peaks. And the amplitudes matrix are adaptively designed by minimizing the cross-correlation peaks with the genetic algorithm. Additionally, the impacts of waveform number, hopping frequency interval and selectable frequency index are also analyzed. The simulation results verify the proposed scheme can design multiple orthogonal large time-bandwidth product OFDM chirp waveforms with low cross-correlation peak and sidelobes and it improves ambiguity performance.

  8. Optimization of dielectric matrix for ZnO nanowire based nanogenerators

    Science.gov (United States)

    Kannan, Santhosh; Parmar, Mitesh; Tao, Ran; Ardila, Gustavo; Mouis, Mireille

    2016-11-01

    This paper reports the role of selection of suitable dielectric layer in nanogenerator (NG) structure and its influence on the output performance. The basic NG structure is a composite material integrating hydrothermally grown vertical piezoelectric zinc oxide (ZnO) nanowires (NWs) into a dielectric matrix. To accomplish this study, three materials - poly methyl methacrylate (PMMA), silicon nitride (Si3N4) and aluminium oxide (Al2O3) are selected, processed and used as matrix dielectric in NGs. Scanning electron microscopy (SEM) analysis shows the well-aligned NWs with a diameter of 200±50 nm and length of 3.5±0.3 μm. This was followed by dielectric material deposition as a matrix material. After fabricating NG devices, the output generated voltage under manual and automatic bending were recorded, observed and analyzed for the selection of the best dielectric material to obtain an optimum output. The maximum peak-to-peak open-circuit voltage output for PMMA, Si3N4 and Al2O3 under manual bending was recorded as approximately 880 mV, 1.2 V and 2.1 V respectively. These preliminary results confirm the predicted effect of using more rigid dielectrics as matrix material for the NGs. The generated voltage is increased by about 70% using Si3N4 or Al2O3, instead of a less rigid material as PMMA.

  9. A Rank-Constrained Matrix Representation for Hypergraph-Based Subspace Clustering

    Directory of Open Access Journals (Sweden)

    Yubao Sun

    2015-01-01

    Full Text Available This paper presents a novel, rank-constrained matrix representation combined with hypergraph spectral analysis to enable the recovery of the original subspace structures of corrupted data. Real-world data are frequently corrupted with both sparse error and noise. Our matrix decomposition model separates the low-rank, sparse error, and noise components from the data in order to enhance robustness to the corruption. In order to obtain the desired rank representation of the data within a dictionary, our model directly utilizes rank constraints by restricting the upper bound of the rank range. An alternative projection algorithm is proposed to estimate the low-rank representation and separate the sparse error from the data matrix. To further capture the complex relationship between data distributed in multiple subspaces, we use hypergraph to represent the data by encapsulating multiple related samples into one hyperedge. The final clustering result is obtained by spectral decomposition of the hypergraph Laplacian matrix. Validation experiments on the Extended Yale Face Database B, AR, and Hopkins 155 datasets show that the proposed method is a promising tool for subspace clustering.

  10. A general X-ray fluorescence spectrometric technique based on simple corrections for matrix effects

    International Nuclear Information System (INIS)

    Kruidhof, H.

    1978-01-01

    The method reported, which is relatively simple and generally applicable for most materials, involves a combination of borax fusion with matrix effect corrections. The latter are done with algorithms, which are derived from the intensity formulae, together with empirical coefficients. (Auth.)

  11. Models based on multichannel R-matrix theory for evaluating light element reactions

    International Nuclear Information System (INIS)

    Dodder, D.C.; Hale, G.M.; Nisley, R.A.; Witte, K.; Young, P.G.

    1975-01-01

    Multichannel R-matrix theory has been used as a basis for models for analysis and evaluation of light nuclear systems. These models have the characteristic that data predictions can be made utilizing information derived from other reactions related to the one of primary interest. Several examples are given where such an approach is valid and appropriate. (auth.)

  12. Review Fisher Matrix-based Predictions for Measuring the z = 3.35 ...

    Indian Academy of Sciences (India)

    Abstract. We use the Fisher matrix formalism to predict the prospects of measuring the redshifted 21- cm power spectrum in different k-bins using observations with the upcoming Ooty Wide Field Array. (OWFA) which will operate at 326.5MHz. This corresponds to neutral hydrogen (HI) at z = 3.35, and a measurement of the ...

  13. Microstructure characterization of laser-deposited titanium carbide and zirconium-based titanium metal matrix composites

    CSIR Research Space (South Africa)

    Ochonogor, OF

    2012-09-01

    Full Text Available . In this work, the technique is used to fabricate metal matrix composites (MMCs) by using an elementally blended feedstock combining metal and ceramic powders in the melt pool, which melt and solidify to create the required morphology. Ti6Al4V + TiC MMCs were...

  14. Comparison of linear and non-linear monotonicity-based shape reconstruction using exact matrix characterizations

    DEFF Research Database (Denmark)

    Garde, Henrik

    2018-01-01

    . For a fair comparison, exact matrix characterizations are used when probing the monotonicity relations to avoid errors from numerical solution to PDEs and numerical integration. Using a special factorization of the Neumann-to-Dirichlet map also makes the non-linear method as fast as the linear method...

  15. Acid-base-driven matrix-assisted mass spectrometry for targeted metabolomics

    Czech Academy of Sciences Publication Activity Database

    Shroff, R.; Rulíšek, Lubomír; Doubský, J.; Svatoš, Aleš

    2009-01-01

    Roč. 106, č. 25 (2009), s. 10092-10096 ISSN 0027-8424 R&D Projects: GA MŠk LC512 Institutional research plan: CEZ:AV0Z40550506 Keywords : clinical diagnostic * matrix design * positive /negative ions * MALDI Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 9.432, year: 2009

  16. Effects of surface water on the adsorption of inert gases

    International Nuclear Information System (INIS)

    Gammage, R.B.; Holmes, H.F.

    1976-01-01

    Molecular water on mildly outgassed open oxide surfaces can, under special circumstances, significantly reduce the monolayer capacity for inert gas molecules. Non-porous thoria and cubic europia are two examples. The special proviso is that the surface be sufficiently uniform to permit the formation of a well structured, ice-like surface with non-polar character. This type of behavior reaches an extreme for a non-porous ground calcite; surface water converts a Type II isotherm for krypton into a Type III. These structured layers of adsorbed water adsorb nitrogen in a manner very similar to that found for various types of ice. For open oxide surface in a more thoroughly outgassed condition, the BET specific surface area does not generally vary with outgassing temperature at and above 150 0 C. The area occupied by an inert gas molecule does not change, therefore, with varying hydroxyl ion content of the surface

  17. The electroweak phase transition in the Inert Doublet Model

    Energy Technology Data Exchange (ETDEWEB)

    Blinov, Nikita [Department of Physics, University of California Santa Cruz,1156 High St, Santa Cruz, CA 95064 (United States); Santa Cruz Institute for Particle Physics,1156 High St, Santa Cruz, CA 95064 (United States); Theory Department, TRIUMF,4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Department of Physics and Astronomy, University of British Columbia,Vancouver, BC V6T 1Z1 (Canada); Profumo, Stefano; Stefaniak, Tim [Department of Physics, University of California Santa Cruz,1156 High St, Santa Cruz, CA 95064 (United States); Santa Cruz Institute for Particle Physics,1156 High St, Santa Cruz, CA 95064 (United States)

    2015-07-21

    We study the strength of a first-order electroweak phase transition in the Inert Doublet Model (IDM), where particle dark matter (DM) is comprised of the lightest neutral inert Higgs boson. We improve over previous studies in the description and treatment of the finite-temperature effective potential and of the electroweak phase transition. We focus on a set of benchmark models inspired by the key mechanisms in the IDM leading to a viable dark matter particle candidate, and illustrate how to enhance the strength of the electroweak phase transition by adjusting the masses of the yet undiscovered IDM Higgs states. We argue that across a variety of DM masses, obtaining a strong enough first-order phase transition is a generic possibility in the IDM. We find that due to direct dark matter searches and collider constraints, a sufficiently strong transition and a thermal relic density matching the universal DM abundance is possible only in the Higgs funnel regime.

  18. The electroweak phase transition in the Inert Doublet Model

    Energy Technology Data Exchange (ETDEWEB)

    Blinov, Nikita; Profumo, Stefano; Stefaniak, Tim, E-mail: nblinov@triumf.ca, E-mail: profumo@ucsc.edu, E-mail: tistefan@ucsc.edu [Department of Physics, University of California Santa Cruz, 1156 High St, Santa Cruz, CA 95064 (United States)

    2015-07-01

    We study the strength of a first-order electroweak phase transition in the Inert Doublet Model (IDM), where particle dark matter (DM) is comprised of the lightest neutral inert Higgs boson. We improve over previous studies in the description and treatment of the finite-temperature effective potential and of the electroweak phase transition. We focus on a set of benchmark models inspired by the key mechanisms in the IDM leading to a viable dark matter particle candidate, and illustrate how to enhance the strength of the electroweak phase transition by adjusting the masses of the yet undiscovered IDM Higgs states. We argue that across a variety of DM masses, obtaining a strong enough first-order phase transition is a generic possibility in the IDM. We find that due to direct dark matter searches and collider constraints, a sufficiently strong transition and a thermal relic density matching the universal DM abundance is possible only in the Higgs funnel regime.

  19. A Fast Reactive Power Optimization in Distribution Network Based on Large Random Matrix Theory and Data Analysis

    Directory of Open Access Journals (Sweden)

    Wanxing Sheng

    2016-05-01

    Full Text Available In this paper, a reactive power optimization method based on historical data is investigated to solve the dynamic reactive power optimization problem in distribution network. In order to reflect the variation of loads, network loads are represented in a form of random matrix. Load similarity (LS is defined to measure the degree of similarity between the loads in different days and the calculation method of the load similarity of load random matrix (LRM is presented. By calculating the load similarity between the forecasting random matrix and the random matrix of historical load, the historical reactive power optimization dispatching scheme that most matches the forecasting load can be found for reactive power control usage. The differences of daily load curves between working days and weekends in different seasons are considered in the proposed method. The proposed method is tested on a standard 14 nodes distribution network with three different types of load. The computational result demonstrates that the proposed method for reactive power optimization is fast, feasible and effective in distribution network.

  20. DFT-Based Closed-form Covariance Matrix and Direct Waveforms Design for MIMO Radar to Achieve Desired Beampatterns

    KAUST Repository

    Bouchoucha, Taha

    2017-01-23

    In multiple-input multiple-out (MIMO) radar, for desired transmit beampatterns, appropriate correlated waveforms are designed. To design such waveforms, conventional MIMO radar methods use two steps. In the first step, the waveforms covariance matrix, R, is synthesized to achieve the desired beampattern. While in the second step, to realize the synthesized covariance matrix, actual waveforms are designed. Most of the existing methods use iterative algorithms to solve these constrained optimization problems. The computational complexity of these algorithms is very high, which makes them difficult to use in practice. In this paper, to achieve the desired beampattern, a low complexity discrete-Fourier-transform based closed-form covariance matrix design technique is introduced for a MIMO radar. The designed covariance matrix is then exploited to derive a novel closed-form algorithm to directly design the finite-alphabet constant-envelope waveforms for the desired beampattern. The proposed technique can be used to design waveforms for large antenna array to change the beampattern in real time. It is also shown that the number of transmitted symbols from each antenna depends on the beampattern and is less than the total number of transmit antenna elements.

  1. Passive and active vibration isolation systems using inerter

    Science.gov (United States)

    Alujević, N.; Čakmak, D.; Wolf, H.; Jokić, M.

    2018-03-01

    This paper presents a theoretical study on passive and active vibration isolation schemes using inerter elements in a two degree of freedom (DOF) mechanical system. The aim of the work is to discuss basic capabilities and limitations of the vibration control systems at hand using simple and physically transparent models. Broad frequency band dynamic excitation of the source DOF is assumed. The purpose of the isolator system is to prevent vibration transmission to the receiving DOF. The frequency averaged kinetic energy of the receiving mass is used as the metric for vibration isolation quality. It is shown that the use of inerter element in the passive vibration isolation scheme can enhance the isolation effect. In the active case, a feedback disturbance rejection scheme is considered. Here, the error signal is the receiving body absolute velocity which is directly fed to a reactive force actuator between the source and the receiving bodies. In such a scheme, the so-called subcritical vibration isolation problems exist. These problems are characterised by the uncoupled natural frequency of the receiving body larger than the uncoupled natural frequency of the source body. In subcritical vibration isolation problems, the performance of the active control is limited by poor stability margins. This is because the stable feedback gain is restricted in a narrow range between a minimum and a maximum. However, with the inclusion of an inerter in the isolator, one of the two stability margins can be opened. This enables large, theoretically unlimited negative feedback gains and large active damping of the receiving body vibration. A simple expression for the required inertance is derived.

  2. Inert blanketing of a hydride bed using typical grade protium

    Energy Technology Data Exchange (ETDEWEB)

    Klein, J.E. [Savannah River National Laboratory, Aiken (United States)

    2015-03-15

    This paper describes the impact of 500 ppm (0.05%) impurities in protium on the absorption rate of a 9.66 kg LaNi{sub 4.25}Al{sub 0.75} (LANA0.75) metal hydride bed. The presence of 500 ppm or less inerts (i.e. non-hydrogen isotopes) can significantly impact hydrogen bed absorption rates. The impact on reducing absorption rates is significantly greater than predicted assuming uniform temperature, pressure, and compositions throughout the bed. Possible explanations are discussed. One possibility considered was the feed gas contained impurity levels higher than 500 ppm. It was shown that a level of 5000 ppm of inerts would have been necessary to fit the experimental result so this possibility wa dismissed. Another possibility is that the impurities in the protium supply reacted with the hydride material and partially poisoned the hydride. If the hydride were poisoned with CO or another impurity, the removal of the over-pressure gas in the bed would not be expected to allow the hydride loading of the bed to continue as the experimental results showed, so this possibility was also dismissed. The last possibility questions the validity of the calculations. It is assumed in all the calculations that the gas phase composition, temperature, and pressure are uniform throughout the bed. These assumptions are less valid for large beds where there can be large temperature, pressure, and composition gradients throughout the bed. Eventually the impact of 0.05% inerts in protium on bed absorption rate is shown and explained in terms of an increase in inert partial pressure as the bed was loaded.

  3. Arc melting in inert gas atmosphere of zirconium sponge

    International Nuclear Information System (INIS)

    Julio Junior, O.; Andrade, A.H.P. de

    1991-01-01

    The obtainment of metallic zirconium in laboratory scale with commercial and nuclear quality is the objective of the Metallurgy Department of IEN/CNEN - Brazil, so a melting procedure of zirconium sponge in laboratory scale using an arc furnace in inert atmosphere is developed. The effects of atmosphere operation, and the use of gas absorber and the sponge characteristics over the quality of button in as-cast reporting with hardness measures are described. (C.G.C.)

  4. METHOD OF OBTAINING AN IMPROVED WELD IN INERT ARC WELDING

    Science.gov (United States)

    Correy, T.B.

    1962-12-11

    A method is reported for inert arc welding. An a-c welding current is applied to the workpiece and welding electrode such that the positive portion of each cycle thereof, with the electrode positive, has only sufficient energy to clean the surface of the workpiece and the negative portion of each cycle thereof, with the electrode negative, contains the energy required to weld. (AEC)

  5. Heterogeneous ion-selective membranes: the infuence of the inert matrix polymer on the membrane properties

    Czech Academy of Sciences Publication Activity Database

    Bouzek, K.; Moravcová, S.; Schauer, Jan; Brožová, Libuše; Pientka, Zbyněk

    2010-01-01

    Roč. 40, č. 5 (2010), s. 1005-1018 ISSN 0021-891X R&D Projects: GA ČR GA203/05/0080; GA MPO 2A-1TP1/116 Institutional research plan: CEZ:AV0Z40500505 Keywords : ion-exchange membrane * heterogeneous membrane * ion-exchange capacity Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.496, year: 2010

  6. Elements of comparison between different inert matrix fuels towards plutonium use and safety coefficients

    International Nuclear Information System (INIS)

    Baldi, St.; Porta, J.

    2000-08-01

    This work deals with the CERMET fuels, chosen for their good behaviour under irradiation and their high thermal conductivity. The kinetic coefficients have been particularly studied. Comparisons have been made with other solutions using other composite fuels in particular the solid solutions and the ROX solution. The core control requiring an heterogeneous assembly, we propose an assembly whose characteristics are compared with those of the APA reference. (O.M.)

  7. Multi-Mode Estimation for Small Fixed Wing Unmanned Aerial Vehicle Localization Based on a Linear Matrix Inequality Approach.

    Science.gov (United States)

    Elzoghby, Mostafa; Li, Fu; Arafa, Ibrahim I; Arif, Usman

    2017-04-18

    Information fusion from multiple sensors ensures the accuracy and robustness of a navigation system, especially in the absence of global positioning system (GPS) data which gets degraded in many cases. A way to deal with multi-mode estimation for a small fixed wing unmanned aerial vehicle (UAV) localization framework is proposed, which depends on utilizing a Luenberger observer-based linear matrix inequality (LMI) approach. The proposed estimation technique relies on the interaction between multiple measurement modes and a continuous observer. The state estimation is performed in a switching environment between multiple active sensors to exploit the available information as much as possible, especially in GPS-denied environments. Luenberger observer-based projection is implemented as a continuous observer to optimize the estimation performance. The observer gain might be chosen by solving a Lyapunov equation by means of a LMI algorithm. Convergence is achieved by utilizing the linear matrix inequality (LMI), based on Lyapunov stability which keeps the dynamic estimation error bounded by selecting the observer gain matrix (L). Simulation results are presented for a small UAV fixed wing localization problem. The results obtained using the proposed approach are compared with a single mode Extended Kalman Filter (EKF). Simulation results are presented to demonstrate the viability of the proposed strategy.

  8. Topology Optimization of 3-DOF Peristaltic Structure Robot Based on Vector Continuous Mapping Matrix

    Directory of Open Access Journals (Sweden)

    Gao Wang

    2016-01-01

    Full Text Available A mechanism for topology optimization of 3-DOF parallel peristaltic structure robot with vector continuous mapping matrix using Solid Isotropic Material with Penalization (SIMP method is presented in this paper. We focus on how to prevent the differential motion consistency between parallel prototype mechanisms with peristaltic structure. As the conventional parallel robot joints/hinges are no longer needed after topology optimization, therefore, we renamed this kind of 3-DOF robot structures as peristaltic structure. In the proposed method, the vector continuous mapping matrix is built as stress/strain transfer direction conditions for topology optimization of peristaltic structure, and SIMP method is used for multi-inputs and multioutputs decided by parallel prototype mechanisms. Some numerical examples are presented to illustrate the validity of the proposed method.

  9. Multidisciplinary Product Decomposition and Analysis Based on Design Structure Matrix Modeling

    DEFF Research Database (Denmark)

    Habib, Tufail

    2014-01-01

    Design structure matrix (DSM) modeling in complex system design supports to define physical and logical configuration of subsystems, components, and their relationships. This modeling includes product decomposition, identification of interfaces, and structure analysis to increase the architectural...... interactions across subsystems and components. For this purpose, Cambridge advanced modeler (CAM) software tool is used to develop the system matrix. The analysis of the product (printer) architecture includes clustering, partitioning as well as structure analysis of the system. The DSM analysis is helpful...... understanding of the system. Since product architecture has broad implications in relation to product life cycle issues, in this paper, mechatronic product is decomposed into subsystems and components, and then, DSM model is developed to examine the extent of modularity in the system and to manage multiple...

  10. FPGA design and implementation of a matrix multiplier based accelerator for 3D EKF SLAM

    OpenAIRE

    Tortei, Daniel; Piat, Jonathan; Devy, Michel

    2014-01-01

    International audience; In hw/sw co-design FPGAs are being used in order to accelerate existing solutions so they meet real-time constraints. As they consume less power than a standard microprocessor and provide powerful parallel data processing capabilities, they remain a highly optimizable tool and object of research within an embedded system. In this paper we present an efficient architecture for matrix multiplication accelerator conceived as a systolic array co-processor to IBM's PPC440 p...

  11. Correlation density matrices for one-dimensional quantum chains based on the density matrix renormalization group

    International Nuclear Information System (INIS)

    Muender, W; Weichselbaum, A; Holzner, A; Delft, Jan von; Henley, C L

    2010-01-01

    A useful concept for finding numerically the dominant correlations of a given ground state in an interacting quantum lattice system in an unbiased way is the correlation density matrix (CDM). For two disjoint, separated clusters, it is defined to be the density matrix of their union minus the direct product of their individual density matrices and contains all the correlations between the two clusters. We show how to extract from the CDM a survey of the relative strengths of the system's correlations in different symmetry sectors and the nature of their decay with distance (power law or exponential), as well as detailed information on the operators carrying long-range correlations and the spatial dependence of their correlation functions. To achieve this goal, we introduce a new method of analysing the CDM, termed the dominant operator basis (DOB) method, which identifies in an unbiased fashion a small set of operators for each cluster that serve as a basis for the dominant correlations of the system. We illustrate this method by analysing the CDM for a spinless extended Hubbard model that features a competition between charge density correlations and pairing correlations, and show that the DOB method successfully identifies their relative strengths and dominant correlators. To calculate the ground state of this model, we use the density matrix renormalization group, formulated in terms of a variational matrix product state (MPS) approach within which subsequent determination of the CDM is very straightforward. In an extended appendix, we give a detailed tutorial introduction to our variational MPS approach for ground state calculations for one-dimensional quantum chain models. We present in detail how MPSs overcome the problem of large Hilbert space dimensions in these models and describe all the techniques needed for handling them in practice.

  12. Optimization of Carboxymethyl-Xyloglucan-Based Tramadol Matrix Tablets Using Simplex Centroid Mixture Design

    Directory of Open Access Journals (Sweden)

    Ashwini R. Madgulkar

    2013-01-01

    Full Text Available The aim was to determine the release-modifying effect of carboxymethyl xyloglucan for oral drug delivery. Sustained release matrix tablets of tramadol HCl were prepared by wet granulation method using carboxymethyl xyloglucan as matrix forming polymer. HPMC K100M was used in a small amount to control the burst effect which is most commonly seen with natural hydrophilic polymers. A simplex centroid design with three independent variables and two dependent variables was employed to systematically optimize drug release profile. Carboxymethyl xyloglucan , HPMC K100M , and dicalcium phosphate were taken as independent variables. The dependent variables selected were percent of drug release at 2nd hour and at 8th hour . Response surface plots were developed, and optimum formulations were selected on the basis of desirability. The formulated tablets showed anomalous release mechanism and followed matrix drug release kinetics, resulting in regulated and complete release from the tablets within 8 to 10 hours. The polymer carboxymethyl xyloglucan and HPMC K100M had significant effect on drug release from the tablet (. Polynomial mathematical models, generated for various response variables using multiple regression analysis, were found to be statistically significant (. The statistical models developed for optimization were found to be valid.

  13. Matrix coatings based on anodic alumina with carbon nanostructures in the pores

    Science.gov (United States)

    Gorokh, G. G.; Pashechko, M. I.; Borc, J. T.; Lozovenko, A. A.; Kashko, I. A.; Latos, A. I.

    2018-03-01

    The nanoporous anodic alumina matrixes thickness of 1.5 mm and pore sizes of 45, 90 and 145 nm were formed on Si substrates. The tubular carbon nanostructures were synthesized into the matrixes pores by pyrolysis of fluid hydrocarbon xylene with 1% ferrocene. The structure and composition of the matrix coatings were examined by scanning electron microscopy, Auger analysis and Raman spectroscopy. The carbon nanostructures completely filled the pores of templates and uniformly covered the tops. The structure of carbon nanostructures corresponded to the structure of multiwall carbon nanotubes. Investigations of mechanical and tribological properties of nanostructured oxide-carbon composite performed by scratching and nanoindentation showed nonlinear dependencies of the frictional force, penetration depth of the cantilever, hardness and plane strain modulus on the load. It was found that the microhardness of the samples increases with reduced of alumina pore diameter, and the penetration depth of the cantilever into the film grows with carbon nanostructures size. The results showed the high mechanical strength of nanostructured oxide-carbon composite.

  14. Matrix theory

    CERN Document Server

    Franklin, Joel N

    2003-01-01

    Mathematically rigorous introduction covers vector and matrix norms, the condition-number of a matrix, positive and irreducible matrices, much more. Only elementary algebra and calculus required. Includes problem-solving exercises. 1968 edition.

  15. Active flux tungsten inert gas welding of austenitic stainless steel AISI 304

    OpenAIRE

    Klobčar, D.; Tušek; Bizjak, M.; Simončič, S.; Lešer, V.

    2016-01-01

    The paper presents the effects of flux assisted tungsten inert gas (A-TIG) welding of 4 (10) mm thick austenitic stainless steel EN X5CrNi1810 (AISI 304) in the butt joint. The sample dimensions were 300 ´ 50 mm, and commercially available active flux QuickTIG was used for testing. In the planned study the influence of welding position and weld groove shape was analysed based on the penetration depth. A comparison of microstructure formation, grain size and ferrit number between TIG welding a...

  16. A method for calculating regional cerebral blood flow from emission computed tomography of inert gas concentrations

    DEFF Research Database (Denmark)

    Celsis, P; Goldman, T; Henriksen, L

    1981-01-01

    Emission tomography of positron or gamma emitting inert gases allows calculation of regional cerebral blood flow (rCBF) in cross-sectional slices of human brain. An algorithm is presented for rCBF calculations from a sequence of time averaged tomograms using inhaled 133Xe. The approach is designed...... of four 1 min pictures and using a fixed value for the brain:blood partition coefficient, lambda. The method is essentially based on the bolus distribution principle, and it allows the estimation of blood flow in ischemic areas. Application to positron emission tomography is discussed....

  17. The influence of reinforcement size on the microstructure and mechanical behavior of a nanostructured aluminum-based metal matrix composite

    Science.gov (United States)

    Behm, Nathan Adam

    With increased availability and growing commercial applications, aluminum-based metal matrix composites show promise as high specific strength structural materials. Before they can be implemented however, they require thorough characterization and testing. A novel nanostructured aluminum-based metal matrix composite (MMC) was characterized through a combination of microstructural analysis and mechanical testing. Two composites were studied, an aluminum MMC reinforced with 50 nm boron carbide, (B4C) and an aluminum MMC reinforced with 500 nm boron carbide. Transmission electron microscopy (TEM) analysis revealed an ultra-fine grained matrix with grains on the order of 100--300 nm. The quasi-static and dynamic response of the composites was compared with the behavior of the unreinforced aluminum alloy, and it was found that the reinforcement resulted in a 30% improvement in strength. The decrease in the reinforcement size from 500 to 50 nm activated an additional strengthening mechanism, which further improved the strength of the MMC reinforced with the 50 nm B4C. Dynamic compression tests were performed at elevated temperatures up 400°C on the composites, and it was found that they exhibited impressive strengths considering the thermal softening prevalent in aluminum. The reinforcement size was found to play an important role in the strain softening exhibited at elevated temperature, fracture mechanism, and composite strength. Models to describe the composite behavior are presented.

  18. Study on the Seismic Response of a Portal Frame Structure Based on the Transfer Matrix Method of Multibody System

    Directory of Open Access Journals (Sweden)

    Jianguo Ding

    2014-11-01

    Full Text Available Portal frame structures are widely used in industrial building design but unfortunately are often damaged during an earthquake. As a result, a study on the seismic response of this type of structure is important to both human safety and future building designs. Traditionally, finite element methods such as the ANSYS and MIDAS have been used as the primary methods of computing the response of such a structure during an earthquake; however, these methods yield low calculation efficiencies. In this paper, the mechanical model of a single-story portal frame structure with two spans is constructed based on the transfer matrix method of multibody system (MS-TMM; both the transfer matrix of the components in the model and the total transfer matrix equation of the structure are derived, and the corresponding MATLAB program is compiled to determine the natural period and seismic response of the structure. The results show that the results based on the MS-TMM are similar to those obtained by ANSYS, but the calculation time of the MS-TMM method is only 1/20 of that of the ANSYS method. Additionally, it is shown that the MS-TMM method greatly increases the calculation efficiency while maintaining accuracy.

  19. Histopathological Image Classification With Color Pattern Random Binary Hashing-Based PCANet and Matrix-Form Classifier.

    Science.gov (United States)

    Shi, Jun; Wu, Jinjie; Li, Yan; Zhang, Qi; Ying, Shihui

    2017-09-01

    The computer-aided diagnosis for histopathological images has attracted considerable attention. Principal component analysis network (PCANet) is a novel deep learning algorithm for feature learning with the simple network architecture and parameters. In this study, a color pattern random binary hashing-based PCANet (C-RBH-PCANet) algorithm is proposed to learn an effective feature representation from color histopathological images. The color norm pattern and angular pattern are extracted from the principal component images of R, G, and B color channels after cascaded PCA networks. The random binary encoding is then performed on both color norm pattern images and angular pattern images to generate multiple binary images. Moreover, we rearrange the pooled local histogram features by spatial pyramid pooling to a matrix-form for reducing the dimension of feature and preserving spatial information. Therefore, a C-RBH-PCANet and matrix-form classifier-based feature learning and classification framework is proposed for diagnosis of color histopathological images. The experimental results on three color histopathological image datasets show that the proposed C-RBH-PCANet algorithm is superior to the original PCANet and other conventional unsupervised deep learning algorithms, while the best performance is achieved by the proposed feature learning and classification framework that combines C-RBH-PCANet and matrix-form classifier.

  20. Structure and Transport Properties of Mixed-Matrix Membranes Based on Polyimides with ZrO2 Nanostars

    Directory of Open Access Journals (Sweden)

    Maria P. Sokolova

    2016-11-01

    Full Text Available Mixed-matrix membranes based on amorphous and semi-crystalline polyimides with zirconium dioxide (ZrO2 nanostars were synthesized. Amorphous poly(4,4′-oxydiphenylenepyromellitimide and semi-crystalline polyimide prepared from 1,4-bis(4-aminophenoxybenzene and 4,4’-oxydiphthalic anhydride were used. The effect of ZrO2 nanostars on the structure and morphology of nanocomposite membranes was studied by wide-angle X-ray scattering, scanning electron microscopy, atomic force microscopy, and contact angle measurements. Thermal properties and stability were investigated by thermogravimetric analysis and differential scanning calorimetry. Transport properties of hybrid membranes containing 5 wt % ZrO2 were tested for pervaporation of a mixture of butanol–water with 10 wt % H2O content. It was found that a significant amount of the ZrO2 added to the semi-crystalline polyimide is encapsulated inside spherulites. Therefore, the beneficial influence of inorganic filler on the selectivity of mixed-matrix membrane with respect to water was hampered. Mixed-matrix membranes based on amorphous polymer demonstrated the best performance, because water molecules had higher access to inorganic particles.

  1. Synthesis and physical properties of new layered double hydroxides based on ionic liquids: Application to a polylactide matrix

    KAUST Repository

    Livi, Sébastien

    2012-12-01

    Ionic liquids based on tetraalkylphosphonium salts combined with different anions (decanoate and dodecylsulfonate) have been used as intercalating agents of layered double hydroxides (LDHs) by ion exchange. The synthesized phosphonium-treated LDHs display a dramatically improved thermal degradation and a significant increase in the interlayer distance as confirmed by thermogravimetric analysis (TGA) and X-ray Diffraction (XRD), respectively. To highlight the effect of thermostable ionic liquids, a very low amount of LDHs has been introduced within a polylactide (PLA) matrix and PLA/LDHs nanocomposites have been processed in melt by twin-screw extrusion. Then, transmission electron microscopy (TEM) analysis has been used to investigate the influence of ILs on the different morphologies of these nanocomposites. Even though the thermal stability of PLA matrix decreased, an excellent stiffness-toughness compromise has been obtained. © 2012 Elsevier Inc.

  2. High-Performance Cementitious Matrix using Carbon Nanofibers

    Directory of Open Access Journals (Sweden)

    Muhammad Maqbool Sadiq Awan

    2017-03-01

    Full Text Available Graphite nanomaterials would realize their reinforcement potential within cement-based materials when they are thoroughly dispersed and effectively bonded to cement hydrates. Thorough dispersion of graphite nanomaterials in the fresh cementitious matrix encounters challenges associated with the hydrophobic nature of nanomaterial surfaces and their strong tendency towards agglomeration via attractive van der Waals forces. Effective interfacial interactions with cement hydrates are further challenged by the relatively inert nature of nanomaterial surfaces. An experimental program was conducted with the objective of effectively utilizing both acid-oxidized and pristine carbon nanofibers towards reinforcement of high-performance cementitious pastes. Hybrid reinforcement systems comprising optimum volume fraction of carbon nanofibers and micro-scale fibers were also evaluated in cementitious matrices. The improvements in nanofiber dispersion and interfacial interactions resulting from acid-oxidation and use of proper dispersion techniques were found to bring about significant gains in the engineering properties of high-performance cementitious materials.

  3. Subspace-Based Noise Reduction for Speech Signals via Diagonal and Triangular Matrix Decompositions: Survey and Analysis

    Directory of Open Access Journals (Sweden)

    Søren Holdt Jensen

    2007-01-01

    Full Text Available We survey the definitions and use of rank-revealing matrix decompositions in single-channel noise reduction algorithms for speech signals. Our algorithms are based on the rank-reduction paradigm and, in particular, signal subspace techniques. The focus is on practical working algorithms, using both diagonal (eigenvalue and singular value decompositions and rank-revealing triangular decompositions (ULV, URV, VSV, ULLV, and ULLIV. In addition, we show how the subspace-based algorithms can be analyzed and compared by means of simple FIR filter interpretations. The algorithms are illustrated with working Matlab code and applications in speech processing.

  4. Matrix analysis

    CERN Document Server

    Bhatia, Rajendra

    1997-01-01

    A good part of matrix theory is functional analytic in spirit. This statement can be turned around. There are many problems in operator theory, where most of the complexities and subtleties are present in the finite-dimensional case. My purpose in writing this book is to present a systematic treatment of methods that are useful in the study of such problems. This book is intended for use as a text for upper division and gradu­ ate courses. Courses based on parts of the material have been given by me at the Indian Statistical Institute and at the University of Toronto (in collaboration with Chandler Davis). The book should also be useful as a reference for research workers in linear algebra, operator theory, mathe­ matical physics and numerical analysis. A possible subtitle of this book could be Matrix Inequalities. A reader who works through the book should expect to become proficient in the art of deriving such inequalities. Other authors have compared this art to that of cutting diamonds. One first has to...

  5. Matrix completion by deep matrix factorization.

    Science.gov (United States)

    Fan, Jicong; Cheng, Jieyu

    2018-02-01

    Conventional methods of matrix completion are linear methods that are not effective in handling data of nonlinear structures. Recently a few researchers attempted to incorporate nonlinear techniques into matrix completion but there still exists considerable limitations. In this paper, a novel method called deep matrix factorization (DMF) is proposed for nonlinear matrix completion. Different from conventional matrix completion methods that are based on linear latent variable models, DMF is on the basis of a nonlinear latent variable model. DMF is formulated as a deep-structure neural network, in which the inputs are the low-dimensional unknown latent variables and the outputs are the partially observed variables. In DMF, the inputs and the parameters of the multilayer neural network are simultaneously optimized to minimize the reconstruction errors for the observed entries. Then the missing entries can be readily recovered by propagating the latent variables to the output layer. DMF is compared with state-of-the-art methods of linear and nonlinear matrix completion in the tasks of toy matrix completion, image inpainting and collaborative filtering. The experimental results verify that DMF is able to provide higher matrix completion accuracy than existing methods do and DMF is applicable to large matrices. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Unidirectional fibers and polyurethane elastomer matrix based composites synthesis and properties. Ph.D. Thesis

    Science.gov (United States)

    Chakar, A.

    1984-01-01

    A study of the properties and manufacturing techniques for long-fiber reinforced elastomeric composites for flexible and damping structural materials is presented. Attention is given to the usage of polyurethane in the matrix to obtain plastic elastomeric matrices and vitreous transition temperatures which vary from -80 C to 10 C, as well as assure good fiber adhesion. Various polyurethane formulations synthesized from diisocyanate prepolymers are examined in terms of mechanical and thermal properties. The principal reinforcing fiber selected is a unidirectional glass cloth.

  7. A new approach based on transfer matrix formalism to characterize porous silicon layers by reflectometry

    Energy Technology Data Exchange (ETDEWEB)

    Pirasteh, P. [RESO Laboratory (EA 3380), ENIB, CS 73862, 29238 Brest Cedex 3 (France); Optronics Laboratory, ENSSAT, UMR 6082, BP 80518, 6 rue de Kerampont, 22305 Lannion Cedex (France); Boucher, Y.G. [RESO Laboratory (EA 3380), ENIB, CS 73862, 29238 Brest Cedex 3 (France); Charrier, J.; Dumeige, Y. [Optronics Laboratory, ENSSAT, UMR 6082, BP 80518, 6 rue de Kerampont, 22305 Lannion Cedex (France)

    2007-07-01

    We use reflectometry coupled to transfer matrix formalism in order to investigate the comparative effect of surface (localized) and volume (distributed) losses inside a porous silicon monolayer. Both are modeled as fictive absorption. Surface losses are described as a Dirac-like singularity of permittivity localized at an interface whereas volume losses are described trough the imaginary part of the porous silicon complex permittivity. A good agreement with experimental data is determined by this formalism. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. A spectral method to detect community structure based on distance modularity matrix

    Science.gov (United States)

    Yang, Jin-Xuan; Zhang, Xiao-Dong

    2017-08-01

    There are many community organizations in social and biological networks. How to identify these community structure in complex networks has become a hot issue. In this paper, an algorithm to detect community structure of networks is proposed by using spectra of distance modularity matrix. The proposed algorithm focuses on the distance of vertices within communities, rather than the most weakly connected vertex pairs or number of edges between communities. The experimental results show that our method achieves better effectiveness to identify community structure for a variety of real-world networks and computer generated networks with a little more time-consumption.

  9. Creep-fatigue behaviour of aluminum alloy-based metal matrix composite

    International Nuclear Information System (INIS)

    Barbera, Daniele; Chen, Haofeng; Liu, Yinghua

    2016-01-01

    Metal Matrix Composite (MMC) represents a valuable option as structural material for different type of structures and components. Despite this they struggle to become widely adopted due to expensive manufacturing process and complex microstructural behaviour. When subjected to cyclic load conditions the structural response of MMC is not trivial, and becomes even more difficult when high temperature load is involved. Different failure mechanisms would happen and they are originated by the different material properties between the fibre and surrounding matrix. Among all, the mismatch of thermal expansion coefficient is recognized to be the dominant one. The significantly differing coefficients of thermal expansion between ceramic and metal give rise to micro thermal stresses, which enhance the initiation of matrix micro cracks. Their performance under varying load and high temperature is complex, and hence it is difficult to have a clear understanding of the structural responses, especially when fatigue and creep damages become the main failures of MMCs. To improve current understanding of the relationship between creep fatigue interaction of MMCs, the history of thermal and mechanical loading, and the creep dwell period, a highly accurate but robust direct simulation technique on the basis of the Linear Matching Method (LMM) framework has been proposed in this paper, and been applied to model the fatigue and creep behaviour of MMCs. A homogenised FE model is considered in all analyses, which consist of continuous silicon carbide fibres embedded in a square 2024T3 aluminium alloy matrix array. Various factors that affect creep and fatigue behaviours of composites are analysed and discussed, including effects of the applied load level, dwell period and temperature on the MMC's performance. The effects of reversed plasticity on stress relaxation and creep deformation of MMC are investigated, and the behaviours of cyclically enhanced creep and elastic follow-up are

  10. Spatially dependent burnup implementation into the nodal program based on the finite element response matrix method

    International Nuclear Information System (INIS)

    Yoriyaz, H.

    1986-01-01

    In this work a spatial burnup scheme and feedback effects has been implemented into the FERM ( 'Finite Element Response Matrix' )program. The spatially dependent neutronic parameters have been considered in three levels: zonewise calculation, assembly wise calculation and pointwise calculation. Flux and power distributions and the multiplication factor were calculated and compared with the results obtained by CITATIOn program. These comparisons showed that processing time in the Ferm code has been hundred of times shorter and no significant difference has been observed in the assembly average power distribution. (Author) [pt

  11. Synergization of silicone with developed crosslinking to soy-based polyurethane foam matrix

    Science.gov (United States)

    Elvistia Firdaus, Flora

    2014-06-01

    Flexible polyurethane foam obtained from reaction of soybased polyol with TDI:MDI (80:20), and surfactant. The goal of this research is to determine the synergization effect of silicone with low molecular alcohols; methanol and ethylene glycol (EG) in soy-polyurethane formula on holding moisture of foams to density, foam solutions capacity, and cellular morphology. The optimized of polyol was achieved by ratio of epoxide/methanol 1:6 (mol/mol), and epoxide/EG 1:3 (mol/mol). It was found silicone surfactant can minimize solution absorbency in polyurethane foam matrix.

  12. Research on Modified Root-MUSIC Algorithm of DOA Estimation Based on Covariance Matrix Reconstruction

    Directory of Open Access Journals (Sweden)

    Changgan SHU

    2014-09-01

    Full Text Available In the standard root multiple signal classification algorithm, the performance of direction of arrival estimation will reduce and even lose effect in circumstances that a low signal noise ratio and a small signals interval. By reconstructing and weighting the covariance matrix of received signal, the modified algorithm can provide more accurate estimation results. The computer simulation and performance analysis are given next, which show that under the condition of lower signal noise ratio and stronger correlation between signals, the proposed modified algorithm could provide preferable azimuth estimating performance than the standard method.

  13. A New Real Time Lyapunov Based Controller for Power Quality Improvement in Unified Power Flow Controllers Using Direct Matrix Converters

    Directory of Open Access Journals (Sweden)

    Joaquim Monteiro

    2017-06-01

    Full Text Available This paper proposes a Direct Matrix Converter operating as a Unified Power Flow Controller (DMC-UPFC with an advanced control method for UPFC, based on the Lyapunov direct method, presenting good results in power quality assessment. This control method is used for real-time calculation of the appropriate matrix switching state, determining which switching state should be applied in the following sampling period. The control strategy takes into account active and reactive power flow references to choose the vector converter closest to the optimum. Theoretical principles for this new real-time vector modulation and control applied to the DMC-UPFC with input filter are established. The method needs DMC-UPFC dynamic equations to be solved just once in each control cycle, to find the required optimum vector, in contrast to similar control methods that need 27 vector estimations per control cycle. The designed controller’s performance was evaluated using Matlab/Simulink software. Controllers were also implemented using a digital signal processing (DSP system and matrix hardware. Simulation and experimental results show decoupled transmission line active (P and reactive (Q power control with zero theoretical error tracking and fast response. Output currents and voltages show small ripple and low harmonic content.

  14. A Novel Pre-Processing Technique for Original Feature Matrix of Electronic Nose Based on Supervised Locality Preserving Projections

    Directory of Open Access Journals (Sweden)

    Pengfei Jia

    2016-06-01

    Full Text Available An electronic nose (E-nose consisting of 14 metal oxide gas sensors and one electronic chemical gas sensor has been constructed to identify four different classes of wound infection. However, the classification results of the E-nose are not ideal if the original feature matrix containing the maximum steady-state response value of sensors is processed by the classifier directly, so a novel pre-processing technique based on supervised locality preserving projections (SLPP is proposed in this paper to process the original feature matrix before it is put into the classifier to improve the performance of the E-nose. SLPP is good at finding and keeping the nonlinear structure of data; furthermore, it can provide an explicit mapping expression which is unreachable by the traditional manifold learning methods. Additionally, some effective optimization methods are found by us to optimize the parameters of SLPP and the classifier. Experimental results prove that the classification accuracy of support vector machine (SVM combined with the data pre-processed by SLPP outperforms other considered methods. All results make it clear that SLPP has a better performance in processing the original feature matrix of the E-nose.

  15. Novel porous separator based on PVdF and PE non-woven matrix for rechargeable lithium batteries

    Science.gov (United States)

    Lee, Yong Min; Kim, Jun-Woo; Choi, Nam-Soon; Lee, Je An; Seol, Wan-Ho; Park, Jung-Ki

    The novel porous separator based on PVdF (poly(vinylidene fluoride)) and a PE (polyethylene) non-woven matrix is prepared by coating PVdF/NMP solution on the matrix (NMP: N-methyl-2-pyrrolidone). The pore structure is generated in the PVdF region by phase inversion of the polymer solution. The PE non-woven matrix imparts mechanical strength and a thermal shut-down property to the separator, while the PVdF component provides a hydrophilic ionic conducting phase. The physical properties of the separator, such as morphology, pore size and its distribution, porosity and mechanical strength, are measured. The ionic conductivity of the separator is 8.9 × 10 -4 S cm -1 at 25 °C. The capacity at the C/2 rate is maintained at about 86% of the initial value on the 100th cycle at the room temperature. The electrolyte is stable up to 4.5 V in the presence of the novel separator.

  16. Mitochondrial matrix delivery using MITO-Porter, a liposome-based carrier that specifies fusion with mitochondrial membranes

    Energy Technology Data Exchange (ETDEWEB)

    Yasuzaki, Yukari; Yamada, Yuma [Laboratory for Molecular Design of Pharmaceutics, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812 (Japan); Harashima, Hideyoshi, E-mail: harasima@pharm.hokudai.ac.jp [Laboratory for Molecular Design of Pharmaceutics, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812 (Japan)

    2010-06-25

    Mitochondria are the principal producers of energy in cells of higher organisms. It was recently reported that mutations and defects in mitochondrial DNA (mtDNA) are associated with various mitochondrial diseases including a variety of neurodegenerative and neuromuscular diseases. Therefore, an effective mitochondrial gene therapy and diagnosis would be expected to have great medical benefits. To achieve this, therapeutic agents need to be delivered into the innermost mitochondrial space (mitochondrial matrix), which contains the mtDNA pool. We previously reported on the development of MITO-Porter, a liposome-based carrier that introduces macromolecular cargos into mitochondria via membrane fusion. In this study, we provide a demonstration of mitochondrial matrix delivery and the visualization of mitochondrial genes (mtDNA) in living cells using the MITO-Porter. We first prepared MITO-Porter containing encapsulated propidium iodide (PI), a fluorescent dye used to stain nucleic acids to detect mtDNA. We then confirmed the emission of red-fluorescence from PI by conjugation with mtDNA, when the carriers were incubated in the presence of isolated rat liver mitochondria. Finally, intracellular observation by confocal laser scanning microscopy clearly verified that the MITO-Porter delivered PI to the mitochondrial matrix.

  17. Spectral analysis of the UFBG-based acousto—optical modulator in V-I transmission matrix formalism

    Science.gov (United States)

    Wu, Liang-Ying; Pei, Li; Liu, Chao; Wang, Yi-Qun; Weng, Si-Jun; Wang, Jian-Shuai

    2014-11-01

    In this study, the V-I transmission matrix formalism (V-I method) is proposed to analyze the spectrum characteristics of the uniform fiber Bragg grating (FBG)-based acousto—optic modulators (UFBG-AOM). The simulation results demonstrate that both the amplitude of the acoustically induced strain and the frequency of the acoustic wave (AW) have an effect on the spectrum. Additionally, the wavelength spacing between the primary reflectivity peak and the secondary reflectivity peak is proportional to the acoustic frequency with the ratio 0.1425 nm/MHz. Meanwhile, we compare the amount of calculation. For the FBG whose period is M, the calculation of the V-I method is 4 × (2M-1) in addition/subtraction, 8 × (2M - 1) in multiply/division and 2M in exponent arithmetic, which is almost a quarter of the multi-film method and transfer matrix (TM) method. The detailed analysis indicates that, compared with the conventional multi-film method and transfer matrix (TM) method, the V-I method is faster and less complex.

  18. Spectral analysis of the UFBG-based acousto—optical modulator in V–I transmission matrix formalism

    International Nuclear Information System (INIS)

    Wu Liang-Ying; Pei Li; Liu Chao; Wang Yi-Qun; Weng Si-Jun; Wang Jian-Shuai

    2014-01-01

    In this study, the V–I transmission matrix formalism (V–I method) is proposed to analyze the spectrum characteristics of the uniform fiber Bragg grating (FBG)-based acousto—optic modulators (UFBG-AOM). The simulation results demonstrate that both the amplitude of the acoustically induced strain and the frequency of the acoustic wave (AW) have an effect on the spectrum. Additionally, the wavelength spacing between the primary reflectivity peak and the secondary reflectivity peak is proportional to the acoustic frequency with the ratio 0.1425 nm/MHz. Meanwhile, we compare the amount of calculation. For the FBG whose period is M, the calculation of the V–I method is 4 × (2M–1) in addition/subtraction, 8 × (2M – 1) in multiply/division and 2M in exponent arithmetic, which is almost a quarter of the multi-film method and transfer matrix (TM) method. The detailed analysis indicates that, compared with the conventional multi-film method and transfer matrix (TM) method, the V–I method is faster and less complex. (general)

  19. Mitochondrial matrix delivery using MITO-Porter, a liposome-based carrier that specifies fusion with mitochondrial membranes

    International Nuclear Information System (INIS)

    Yasuzaki, Yukari; Yamada, Yuma; Harashima, Hideyoshi

    2010-01-01

    Mitochondria are the principal producers of energy in cells of higher organisms. It was recently reported that mutations and defects in mitochondrial DNA (mtDNA) are associated with various mitochondrial diseases including a variety of neurodegenerative and neuromuscular diseases. Therefore, an effective mitochondrial gene therapy and diagnosis would be expected to have great medical benefits. To achieve this, therapeutic agents need to be delivered into the innermost mitochondrial space (mitochondrial matrix), which contains the mtDNA pool. We previously reported on the development of MITO-Porter, a liposome-based carrier that introduces macromolecular cargos into mitochondria via membrane fusion. In this study, we provide a demonstration of mitochondrial matrix delivery and the visualization of mitochondrial genes (mtDNA) in living cells using the MITO-Porter. We first prepared MITO-Porter containing encapsulated propidium iodide (PI), a fluorescent dye used to stain nucleic acids to detect mtDNA. We then confirmed the emission of red-fluorescence from PI by conjugation with mtDNA, when the carriers were incubated in the presence of isolated rat liver mitochondria. Finally, intracellular observation by confocal laser scanning microscopy clearly verified that the MITO-Porter delivered PI to the mitochondrial matrix.

  20. Methanol Droplet Combustion in Oxygen-Inert Environments in Microgravity

    Science.gov (United States)

    Nayagam, Vedha; Dietrich, Daniel L.; Hicks, Michael C.; Williams, Forman A.

    2013-01-01

    The Flame Extinguishment (FLEX) experiment that is currently underway in the Combustion Integrated Rack facility onboard the International Space Station is aimed at understanding the effects of inert diluents on the flammability of condensed phase fuels. To this end, droplets of various fuels, including alkanes and alcohols, are burned in a quiescent microgravity environment with varying amounts of oxygen and inert diluents to determine the limiting oxygen index (LOI) for these fuels. In this study we report experimental observations of methanol droplets burning in oxygen-nitrogen-carbon dioxide and oxygen-nitrogen-helium gas mixtures at 0.7 and 1 atmospheric pressures. The initial droplet size varied between approximately 1.5 mm and 4 mm to capture both diffusive extinction brought about by insufficient residence time at the flame and radiative extinction caused by excessive heat loss from the flame zone. The ambient oxygen concentration varied from a high value of 30% by volume to as low as 12%, approaching the limiting oxygen index for the fuel. The inert dilution by carbon dioxide and helium varied over a range of 0% to 70% by volume. In these experiments, both freely floated and tethered droplets were ignited using symmetrically opposed hot-wire igniters and the burning histories were recorded onboard using digital cameras, downlinked later to the ground for analysis. The digital images yielded droplet and flame diameters as functions of time and subsequently droplet burning rate, flame standoff ratio, and initial and extinction droplet diameters. Simplified theoretical models correlate the measured burning rate constant and the flame standoff ratio reasonably well. An activation energy asymptotic theory accounting for time-dependent water dissolution or evaporation from the droplet is shown to predict the measured diffusive extinction conditions well. The experiments also show that the limiting oxygen index for methanol in these diluent gases is around 12% to

  1. Multi-matrix loop equations: algebraic and differential structures and an approximation based on deformation quantization

    International Nuclear Information System (INIS)

    Krishnaswami, Govind S.

    2006-01-01

    Large-N multi-matrix loop equations are formulated as quadratic difference equations in concatenation of gluon correlations. Though non-linear, they involve highest rank correlations linearly. They are underdetermined in many cases. Additional linear equations for gluon correlations, associated to symmetries of action and measure are found. Loop equations aren't differential equations as they involve left annihilation, which doesn't satisfy the Leibnitz rule with concatenation. But left annihilation is a derivation of the commutative shuffle product. Moreover shuffle and concatenation combine to define a bialgebra. Motivated by deformation quantization, we expand concatenation around shuffle in powers of q, whose physical value is 1. At zeroth order the loop equations become quadratic PDEs in the shuffle algebra. If the variation of the action is linear in iterated commutators of left annihilations, these quadratic PDEs linearize by passage to shuffle reciprocal of correlations. Remarkably, this is true for regularized versions of the Yang-Mills, Chern-Simons and Gaussian actions. But the linear equations are underdetermined just as the loop equations were. For any particular solution, the shuffle reciprocal is explicitly inverted to get the zeroth order gluon correlations. To go beyond zeroth order, we find a Poisson bracket on the shuffle algebra and associative q-products interpolating between shuffle and concatenation. This method, and a complementary one of deforming annihilation rather than product are shown to give over and underestimates for correlations of a gaussian matrix model

  2. Conditioning of inorganic ion exchangers based on cerium (IV) antimonate in cement matrix. Vol. 3

    International Nuclear Information System (INIS)

    Aly, H.F.; Zakareia, N.; El-Dessouky, M.I.; Abo-Mosallem, N.M.; EL-Naggar, I.M.

    1996-01-01

    The use of inorganic adsorbents for treatment of aqueous radioactive waste has many advantages; namely; better resistance to chemical action, thermal stability, compatibility with immobilization matrices and resistance to radiation. Inorganic ion exchangers process many properties which make them more suitable for rad waste treatment than organic exchange resins. Inorganic ion exchange materials can be immobilized using cement matrix to obtain good solidified waste form. In this work, the removal of radioactive nuclides from radioactive waste is carried out by chemical in-situ precipitation. The addition of cerium (IV) antimonate (cesb) to cement mixture enhances the compressive strength more than plain cement. Waste package containing cesb increased the compressive strength relative to original ordinary portland cement (OPC) matrix for waste products immersed in tap water for one month. The compressive strength increases in the order; st Ce Sb> mix Ce Sb> Na Ce Sb> Co Ce Sb> Cs Ce Sb> OPC> Eu Ce Sb> Ce Sb; (mix refers to all the radionuclides used here). The cumulative leached fractions of 60 Co and 134 Cs decreased for solidified waste products containing Ce Sb in comparison to plain cement. 2 figs., 9 tabs

  3. Designing of hydroxyapatite-gelatin based porous matrix as bone substitute: Correlation with biocompatibility aspects

    Directory of Open Access Journals (Sweden)

    2008-03-01

    Full Text Available In the present study polyacrylamide (PAm-gelatin-hydroxyapatite (HA composites have been synthesized by suspension polymerization method. The prepared composites were characterized by Fourier transform spectroscopy (FTIR which revealed the presence of functional groups in the composite. The X-ray diffraction (XRD studies indicated that HA powder was present in nano size. Thermogravimetric analysis (TGA revealed that composite is more thermally stable than the polymer matrix alone. The morphology of composite studied by optical microscopy (OPM and scanning electron microscopy (SEM suggested that pore size was between 3–20 µm. The composites showed adequately good mechanical properties as evident from the varying compressive strength and modulus in the range 31.57±8.16 MPa and 745±388 MPa, respectively. The water sorption behavior was found to be dependent on the chemical composition of the matrix and the sorption data were used to calculate network parameters. The porosity of composite varied between 4 to 30.66%.The in vitro blood compatibility indicated that the adsorption of bovine serum albumin (BSA varied from 0.11 to 0.24 mg•g–1, the percentage haemolysis was between 2.4 to 6.9% and the weight of blood clot formed on the composite surfaces were found in the range 11 to 52 mg.

  4. Cathodic Polarization Coats Titanium Based Implant Materials with Enamel Matrix Derivate (EMD

    Directory of Open Access Journals (Sweden)

    Matthias J. Frank

    2014-03-01

    Full Text Available The idea of a bioactive surface coating that enhances bone healing and bone growth is a strong focus of on-going research for bone implant materials. Enamel matrix derivate (EMD is well documented to support bone regeneration and activates growth of mesenchymal tissues. Thus, it is a prime candidate for coating of existing implant surfaces. The aim of this study was to show that cathodic polarization can be used for coating commercially available implant surfaces with an immobilized but functional and bio-available surface layer of EMD. After coating, XPS revealed EMD-related bindings on the surface while SIMS showed incorporation of EMD into the surface. The hydride layer of the original surface could be activated for coating in an integrated one-step process that did not require any pre-treatment of the surface. SEM images showed nano-spheres and nano-rods on coated surfaces that were EMD-related. Moreover, the surface roughness remained unchanged after coating, as it was shown by optical profilometry. The mass peaks observed in the matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF MS analysis confirmed the integrity of EMD after coating. Assessment of the bioavailability suggested that the modified surfaces were active for osteoblast like MC3M3-E1 cells in showing enhanced Coll-1 gene expression and ALP activity.

  5. Nuclear Technology. Course 28: Welding Inspection. Module 28-3, Tungsten Inert Gas (TIG), Metal Inert Gas (MIG) and Submerged Arc Welding.

    Science.gov (United States)

    Espy, John

    This third in a series of ten modules for a course titled Welding Inspection presents the apparatus, process techniques, procedures, applications, associated defects, and inspection for the tungsten inert gas, metal inert gas, and submerged arc welding processes. The module follows a typical format that includes the following sections: (1)…

  6. Magnetoresponsive Poly(ether sulfone)-Based Iron Oxide cum Hydrogel Mixed Matrix Composite Membranes for Switchable Molecular Sieving.

    Science.gov (United States)

    Lin, Xi; Nguyen Quoc, Bao; Ulbricht, Mathias

    2016-10-26

    Stimuli-responsive membranes that can adjust mass transfer and interfacial properties "on demand" have drawn large interest over the last few decades. Here, we designed and prepared a novel magnetoresponsive separation membrane with remote switchable molecular sieving effect by simple one-step and scalable nonsolvent induced phase separation (NIPS) process. Specifically, poly(ether sulfone) (PES) as matrix for an anisotropic membrane, prefabricated poly(N-isopropylacrylamide) (PNIPAAm) nanogel (NG) particles as functional gates, and iron oxide magnetic nanoparticles (MNP) as localized heaters were combined in a synergistic way. Before membrane casting, the properties of the building blocks, including swelling property and size distribution for NG, and magnetic property and heating efficiency for MNP, were investigated. Further, to identify optimal film casting conditions for membrane preparation by NIPS, in-depth rheological study of the effects of composition and temperature on blend dope solutions was performed. At last, a composite membrane with 10% MNP and 10% NG blended in a porous PES matrix was obtained, which showed a large, reversible, and stable magneto-responsivity. It had 9 times higher water permeability at the "on" state of alternating magnetic field (AMF) than at the "off"-state. Moreover, the molecular weight cutoff of such membrane could be reversibly shifted from ∼70 to 1750 kDa by switching off or on the external AMF, as demonstrated in dextran ultrafiltration tests. Overall, it has been proved that the molecular sieving performance of the novel mixed matrix composite membrane can be controlled by the swollen/shrunken state of PNIPAAm NG embedded in the nanoporous barrier layer of a PES-based anisotropic porous matrix, via the heat generation of nearby MNP. And the structure of such membrane can be tailored by the NIPS process conditions. Such membrane has potential as enabling material for remote-controlled drug release systems or devices for

  7. Participants' evaluation of a group-based organisational assessment tool in Danish general practice: the Maturity Matrix.

    Science.gov (United States)

    Buch, Martin Sandberg; Edwards, Adrian; Eriksson, Tina

    2009-01-01

    The Maturity Matrix is a group-based formative self-evaluation tool aimed at assessing the degree of organisational development in general practice and providing a starting point for local quality improvement. Earlier studies of the Maturity Matrix have shown that participants find the method a useful way of assessing their practice's organisational development. However, little is known about participants' views on the resulting efforts to implement intended changes. To explore users' perspectives on the Maturity Matrix method, the facilitation process, and drivers and barriers for implementation of intended changes. Observation of two facilitated practice meetings, 17 semi-structured interviews with participating general practitioners (GPs) or their staff, and mapping of reasons for continuing or quitting the project. General practices in Denmark Main outcomes: Successful change was associated with: a clearly identified anchor person within the practice, a shared and regular meeting structure, and an external facilitator who provides support and counselling during the implementation process. Failure to implement change was associated with: a high patient-related workload, staff or GP turnover (that seemed to affect small practices more), no clearly identified anchor person or anchor persons who did not do anything, no continuous support from an external facilitator, and no formal commitment to working with agreed changes. Future attempts to improve the impact of the Maturity Matrix, and similar tools for quality improvement, could include: (a) attention to matters of variation caused by practice size, (b) systematic counselling on barriers to implementation and support to structure the change processes, (c) a commitment from participants that goes beyond participation in two-yearly assessments, and (d) an anchor person for each identified goal who takes on the responsibility for improvement in practice.

  8. Nucleosynthesis confronts an unstable inert 17 keV state

    International Nuclear Information System (INIS)

    Enqvist, K.; Kainulainen, K.; Thomson, M.

    1991-01-01

    We study the cosmological consequences of an inert 17 keV state mixing with the electron neutrino. We find that the nucleosynthesis upper bound on the primordial helium abundance prohibits the existence of such a state, unless its lifetime falls into the range 6x10 -4 s vac -2 s. In this range the decay occurs after the chemical decoupling of the electron neutrinos and before the beginning of the nucleosynthesis, with the result that the predicted helium abundance can be lower than what it would be in the standard scenario. (orig.)

  9. Vector boson fusion in the inert doublet model

    Science.gov (United States)

    Dutta, Bhaskar; Palacio, Guillermo; Restrepo, Diego; Ruiz-Álvarez, José D.

    2018-03-01

    In this paper we probe the inert Higgs doublet model at the LHC using vector boson fusion (VBF) search strategy. We optimize the selection cuts and investigate the parameter space of the model and we show that the VBF search has a better reach when compared with the monojet searches. We also investigate the Drell-Yan type cuts and show that they can be important for smaller charged Higgs masses. We determine the 3 σ reach for the parameter space using these optimized cuts for a luminosity of 3000 fb-1 .

  10. Inert Anode Life in Low Temperature Reduction Process

    Energy Technology Data Exchange (ETDEWEB)

    Bradford, Donald R.

    2005-06-30

    The production of aluminum metal by low temperature electrolysis utilizing metal non-consumable anodes and ceramic cathodes was extensively investigated. Tests were performed with traditional sodium fluoride--aluminum fluoride composition electrolytes, potassium fluoride-- aluminum fluoride electrolytes, and potassium fluoride--sodium fluoride--aluminum fluoride electrolytes. All of the Essential First-Tier Requirements of the joint DOE-Aluminum Industry Inert Anode Road Map were achieved and those items yet to be resolved for commercialization of this technology were identified. Methods for the fabrication and welding of metal alloy anodes were developed and tested. The potential savings of energy and energy costs were determined and potential environmental benefits verified.

  11. Ecological risk assessment of agricultural soils for the definition of soil screening values: A comparison between substance-based and matrix-based approaches.

    Science.gov (United States)

    Pivato, Alberto; Lavagnolo, Maria Cristina; Manachini, Barbara; Vanin, Stefano; Raga, Roberto; Beggio, Giovanni

    2017-04-01

    The Italian legislation on contaminated soils does not include the Ecological Risk Assessment (ERA) and this deficiency has important consequences for the sustainable management of agricultural soils. The present research compares the results of two ERA procedures applied to agriculture (i) one based on the "substance-based" approach and (ii) a second based on the "matrix-based" approach. In the former the soil screening values (SVs) for individual substances were derived according to institutional foreign guidelines. In the latter, the SVs characterizing the whole-matrix were derived originally by the authors by means of experimental activity. The results indicate that the "matrix-based" approach can be efficiently implemented in the Italian legislation for the ERA of agricultural soils. This method, if compared to the institutionalized "substance based" approach is (i) comparable in economic terms and in testing time, (ii) is site specific and assesses the real effect of the investigated soil on a battery of bioassays, (iii) accounts for phenomena that may radically modify the exposure of the organisms to the totality of contaminants and (iv) can be considered sufficiently conservative.

  12. An Inert Continuous Microreactor for the Isolation and Analysis of a Single Microbial Cell

    Directory of Open Access Journals (Sweden)

    Katrin Rosenthal

    2015-11-01

    Full Text Available Studying biological phenomena of individual cells is enabled by matching the scales of microbes and cultivation devices. We present a versatile, chemically inert microfluidic lab-on-a-chip (LOC device for biological and chemical analyses of isolated microorganisms. It is based on the Envirostat concept and guarantees constant environmental conditions. A new manufacturing process for direct fusion bonding chips with functional microelectrodes for selective and gentle cell manipulation via negative dielectrophoresis (nDEP was generated. The resulting LOC system offered a defined surface chemistry and exceptional operational stability, maintaining its structural integrity even after harsh chemical treatment. The microelectrode structures remained fully functional after thermal bonding and were proven to be efficient for single-cell trapping via nDEP. The microfluidic network consisted solely of glass, which led to enhanced chip reusability and minimized interaction of the material with chemical and biological compounds. We validated the LOC for single-cell studies with the amino acid secreting bacterium Corynebacterium glutamicum. Intracellular l-lysine production dynamics of individual bacteria were monitored based on a genetically encoded fluorescent nanosensor. The results demonstrate the applicability of the presented LOC for pioneering chemical and biological studies, where robustness and chemically inert surfaces are crucial parameters for approaching fundamental biological questions at a single-cell level.

  13. Formation of a memristor matrix based on titanium oxide and investigation by probe-nanotechnology methods

    Energy Technology Data Exchange (ETDEWEB)

    Avilov, V. I.; Ageev, O. A.; Kolomiitsev, A. S.; Konoplev, B. G., E-mail: kbg@sfedu.ru; Smirnov, V. A.; Tsukanova, O. G. [Southern Federal University, Institute of Nanotechnologies, Electronics, and Electronic Equipment Engineering (Russian Federation)

    2014-12-15

    The results of investigation of a memristor-matrix model on the basis of titanium-oxide nanoscale structures (ONSs) fabricated by methods of focused ion beams and atomic-force microscopy (AFM) are presented. The effect of the intensity of interaction between the AFM probe and the sample surface on the memristor effect in the titanium ONS is shown. The memristor effect in the titanium ONS is investigated by an AFM in the mode of spreading-resistance map. The possibility of the recording and erasure of information in the submicron cells is shown on the basis of using the memristor effect in the titanium ONS, which is most promising for developing the technological processes of the formation of resistive operation memory cells.

  14. Spark plasma sintering of ceramic matrix composite based on alumina, reinforced by carbon nanotubes

    Science.gov (United States)

    Leonov, A. A.; Khasanov, A. O.; Danchenko, V. A.; Khasanov, O. L.

    2017-12-01

    Alumina composites reinforced with 3 vol.% multi-walled carbon nanotubes (MWCNTs) were prepared by spark plasma sintering (SPS). The influence of sintering temperature (1400-1600 °C) on the composites microstructure and mechanical properties was investigated. Microstructure observations of the composite shows that some CNTs site along alumina grains boundary, while others embed into the alumina grains and shows that CNTs bonded strongly with the alumina matrix contributing to fracture toughness and microhardness increase. MWCNTs reinforcing mechanisms including CNT pull-out and crack deflection were directly observed by scanning electron microscope (SEM). For Al2O3/CNT composite sintered at 1600 °C, fracture toughness and microhardness are 4.93 MPa·m1/2 and 23.26 GPa respectively.

  15. Fabrication of omentum-based matrix for engineering vascularized cardiac tissues.

    Science.gov (United States)

    Shevach, Michal; Soffer-Tsur, Neta; Fleischer, Sharon; Shapira, Assaf; Dvir, Tal

    2014-06-01

    Fabricating three-dimensional, biocompatible microenvironments to support functional tissue assembly remains a key challenge in cardiac tissue engineering. We hypothesized that since the omentum can be removed from patients by minimally invasive procedures, the obtained underlying matrices can be manipulated to serve as autologous scaffolds for cardiac patches. Here we initially characterized the structural, biochemical and mechanical properties of the obtained matrix, and demonstrated that cardiac cells cultivated within assembled into elongated and aligned tissues, generating a strong contraction force. Co-culture with endothelial cells resulted in the formation of blood vessel networks in the patch without affecting its function. Finally, we have validated that omental scaffolds can support mesenchymal and induced pluripotent stem cells culture, thus may serve as a platform for engineering completely autologous tissues. We envision that this approach may be suitable for treating the infarcted heart and may open up new opportunities in the broader field of tissue engineering and personalized regenerative medicine.

  16. Matrix based method for synthesis of main intensified and integrated distillation sequences

    International Nuclear Information System (INIS)

    Khalili-Garakani, Amirhossein; Kasiri, Norollah; Ivakpour, Javad

    2016-01-01

    The objective of many studies in this area has involved access to a column-sequencing algorithm enabling designers and researchers alike to generate a wide range of sequences in a broad search space, and be as mathematically and as automated as possible for programing purposes and with good generality. In the present work an algorithm previously developed by the authors, called the matrix method, has been developed much further. The new version of the algorithm includes thermally coupled, thermodynamically equivalent, intensified, simultaneous heat and mass integrated and divided-wall column sequences which are of gross application and provide vast saving potential both on capital investment, operating costs and energy usage in industrial applications. To demonstrate the much wider searchable space now accessible, a three component separation has been thoroughly examined as a case study, always resulting in an integrated sequence being proposed as the optimum.

  17. Stability Analysis of Wireless Measurement and Control System Based on Dynamic Matrix

    Directory of Open Access Journals (Sweden)

    Yongxian SONG

    2014-01-01

    Full Text Available Focus on data packet loss and time delay problems in wireless greenhouse measurement and control system, and temperature and humidity were taken as the research objects, the model of temperature and humidity information transmission was set up by decoupling technology according to the characteristics of wireless greenhouse measurement and control system. According to related theory of exponential stability in network control system, the stability conditions judgment of temperature and humidity control model was established, the linear matrix inequality that time delay and packet loss should satisfy was obtained when wireless measurement and control system was stable operation. The feasibility analysis of linear matrix inequality (LMI was implemented Using LMI toolbox in MATLAB, and the critical values of time delay and packet loss rate were obtained when the system was stable operation. The wireless sensor network control system simulation model with time delay and packet loss was set up using TrueTime toolbox. The simulation results have shown that the system was in a stable state when time delay and packet loss rate obtained were less than the critical values in wireless greenhouse sensor network measurement and control system; With the increase of time delay and packet loss rate, and stable performance drops; When time delay and packet loss rate obtained were more than the critical values, the measurement and control system would be in a state of flux, and when it was serious, even can lead to collapse of the whole system. As a result, the critical values determination of time delay and packet loss rate provided a theoretical basis for establishing stable greenhouse wireless sensor network (WSN measurement and control system in practical application.

  18. Observability Analysis of a Matrix Kalman Filter-Based Navigation System Using Visual/Inertial/Magnetic Sensors

    Directory of Open Access Journals (Sweden)

    Guohu Feng

    2012-06-01

    Full Text Available A matrix Kalman filter (MKF has been implemented for an integrated navigation system using visual/inertial/magnetic sensors. The MKF rearranges the original nonlinear process model in a pseudo-linear process model. We employ the observability rank criterion based on Lie derivatives to verify the conditions under which the nonlinear system is observable. It has been proved that such observability conditions are: (a at least one degree of rotational freedom is excited, and (b at least two linearly independent horizontal lines and one vertical line are observed. Experimental results have validated the correctness of these observability conditions.

  19. Safety and Serological Response to a Matrix Gene-deleted Rabies Virus-based Vaccine Vector in Dogs

    OpenAIRE

    McGettigan, James P.; David, Frederic; Figueiredo, Monica Dias; Minke, Jules; Mebatsion, Teshome; Schnell, Matthias J.

    2014-01-01

    Dogs account for the majority of human exposures and deaths due to rabies virus (RABV) worldwide. In this report, we show that a replication-deficient RABV-based vaccine in which the matrix gene is deleted (RABV- M) is safe and induces rapid and potent VNA titers after a single inoculation in dogs. Average VNA titers peaked at 3.02 or 5.11 International Units (IU/ml) by 14 days post-immunization with a single dose of 106 or 107 focus forming units (ffu), respectively, of RABV- M. By day 70 po...

  20. Central nucleus-nucleus collisions at relativistic energies with a new method based on Random Matrix Theory

    Science.gov (United States)

    Wazir, Z.; G. Nazmitdinov, R.; I. Shahaliev, E.; K. Suleymanov, M.

    2010-08-01

    Using the method based on Random Matrix Theory (RMT), the results for the nearest-neighbor distributions obtained from the experimental data on 12C-C collisions at 4.2 AGeV/c have been discussed and compared with the simulated data on 12C-C collisions at 4.2 AGeV/c produced with the aid of the Dubna Cascade Model. The results show that the correlation of secondary particles decreases with an increasing number of charged particles Nch. These observed changes in the nearest-neighbor distributions of charged particles could be associated with the centrality variation of the collisions.

  1. Moving in extreme environments: inert gas narcosis and underwater activities.

    Science.gov (United States)

    Clark, James E

    2015-01-01

    Exposure to the underwater environment for pleasure or work poses many challenges on the human body including thermal stress, barotraumas, decompression sickness as well as the acute effects of breathing gases under pressure. With the popularity of recreational self-contained underwater breathing apparatus (SCUBA) diving on the increase and deep inland dive sites becoming more accessible, it is important that we understand the effects of breathing pressurised gas at depth can have on the body. One of the common consequences of hyperbaric gas is the narcotic effect of inert gas. Nitrogen (a major component of air) under pressure can impede mental function and physical performance at depths of as little as 10 m underwater. With increased depth, symptoms can worsen to include confusion, disturbed coordination, lack of concentration, hallucinations and unconsciousness. Narcosis has been shown to contribute directly to up to 6% of deaths in divers and is likely to be indirectly associated with other diving incidents at depth. This article explores inert gas narcosis, the effect on divers' movement and function underwater and the proposed physiological mechanisms. Also discussed are some of the factors that affect the susceptibility of divers to the condition. In conclusion, understanding the cause of this potentially debilitating problem is important to ensure that safe diving practices continue.

  2. The Gaseous Explosive Reaction : The Effect of Inert Gases

    Science.gov (United States)

    Stevens, F W

    1928-01-01

    Attention is called in this report to previous investigations of gaseous explosive reactions carried out under constant volume conditions, where the effect of inert gases on the thermodynamic equilibrium was determined. The advantage of constant pressure methods over those of constant volume as applied to studies of the gaseous explosive reaction is pointed out and the possibility of realizing for this purpose a constant pressure bomb mentioned. The application of constant pressure methods to the study of gaseous explosive reactions, made possible by the use of a constant pressure bomb, led to the discovery of an important kinetic relation connecting the rate of propagation of the zone of explosive reaction within the active gases, with the initial concentrations of those gases: s = K(sub 1)(A)(sup n1)(B)(sup n2)(C)(sup n3)------. By a method analogous to that followed in determining the effect of inert gases on the equilibrium constant K, the present paper records an attempt to determine their kinetic effect upon the expression given above.

  3. IDMS: inert dark matter model with a complex singlet

    Science.gov (United States)

    Bonilla, Cesar; Sokolowska, Dorota; Darvishi, Neda; Diaz-Cruz, J. Lorenzo; Krawczyk, Maria

    2016-06-01

    We study an extension of the inert doublet model (IDM) that includes an extra complex singlet of the scalars fields, which we call the IDMS. In this model there are three Higgs particles, among them a SM-like Higgs particle, and the lightest neutral scalar, from the inert sector, remains a viable dark matter (DM) candidate. We assume a non-zero complex vacuum expectation value for the singlet, so that the visible sector can introduce extra sources of CP violation. We construct the scalar potential of IDMS, assuming an exact Z 2 symmetry, with the new singlet being Z 2-even, as well as a softly broken U(1) symmetry, which allows a reduced number of free parameters in the potential. In this paper we explore the foundations of the model, in particular the masses and interactions of scalar particles for a few benchmark scenarios. Constraints from collider physics, in particular from the Higgs signal observed at the Large Hadron Collider with {M}h≈ 125 {{GeV}}, as well as constraints from the DM experiments, such as relic density measurements and direct detection limits, are included in the analysis. We observe significant differences with respect to the IDM in relic density values from additional annihilation channels, interference and resonance effects due to the extended Higgs sector.

  4. Probing the inert doublet dark matter model with Cherenkov telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Cely, Camilo [Service de Physique Théorique, CP225, Université Libre de Bruxelles, Bld du Triomphe, Brussels, 1050 Belgium (Belgium); Gustafsson, Michael [Institute for theoretical Physics—Faculty of Physics, Georg-August University Göttingen, Friedrich-Hund-Platz 1, Göttingen, D-37077 Germany (Germany); Ibarra, Alejandro, E-mail: cgarciac@ulb.ac.be, E-mail: michael.gustafsson@theorie.physik.uni-goettingen.de, E-mail: alejandro.ibarra@ph.tum.de [Physik-Department T30d, Technische Universität München, James-Franck-Straße, Garching, D-85748 Germany (Germany)

    2016-02-01

    We present a detailed study of the annihilation signals of the inert dark matter doublet model in its high mass regime. Concretely, we study the prospects to observe gamma-ray signals of the model in current and projected Cherenkov telescopes taking into account the Sommerfeld effect and including the contribution to the spectrum from gamma-ray lines as well as from internal bremsstrahlung. We show that present observations of the galactic center by the H.E.S.S. instrument are able to exclude regions of the parameter space that give the correct dark matter relic abundance. In particular, models with the charged and the neutral components of the inert doublet nearly degenerate in mass have strong gamma-ray signals. Furthermore, for dark matter particle masses above 1 TeV, we find that the non-observation of the continuum of photons generated by the hadronization of the annihilation products typically give stronger constraints on the model parameters than the sharp spectral features associated to annihilation into monochromatic photons and the internal bremsstrahlung process. Lastly, we also analyze the interplay between indirect and direct detection searches for this model, concluding that the prospects for the former are more promising. In particular, we find that the upcoming Cherenkov Telescope Array will be able to probe a significant part of the high mass regime of the model.

  5. A matrix-based approach to solving the inverse Frobenius-Perron problem using sequences of density functions of stochastically perturbed dynamical systems.

    Science.gov (United States)

    Nie, Xiaokai; Coca, Daniel

    2018-01-01

    The paper introduces a matrix-based approach to estimate the unique one-dimensional discrete-time dynamical system that generated a given sequence of probability density functions whilst subjected to an additive stochastic perturbation with known density.

  6. Analysis of Island Land Use Change Based on Transfer Matrix'a Case Study of Dongtou Island in Zhejiang Province

    Science.gov (United States)

    Wang, Liang; Tao, Kunwang; Qian, Xinlin

    2015-04-01

    With the increasing developments of islands, the protection and management of island's natural resources are imperative. The core of islands' protection and management is to acquire the information of changes of the land use and land cover. What's more, the purpose of the islands' land use change information analysis is to plan the effective protection of land resource, achieve scientific management and sustainable utilization. Based on the improved calculation method of land use change and the computational model of change rate of the land use, an analysis of land use transfer matrix and transfer probability matrix is presented, and the method of land use change analysis based on the transfer matrix is proposed in this paper. And then the comparative analysis of all types of land use transfer is introduced. Taken the island of Dongtou in Zhejiang Province as the case, with the SPOT-5 satellite image in 2005 and the aerial image in 2011 as the data source, the current situation of land utilization of Dongtou Island and its land use change are analyzed. The experiment results show that, from 2005 to 2011, the greatest changes are the structures and water, followed by the forest land, grassland, cultivated land and others. The major change of structure and forest is the net change, while the major change of the water and grassland is the swap change. From the perspective of increment, the conversion from waters to structure has the most advantage, followed by water converted to grassland and road. To see from the loss, structures converted into roads and buildings have the most superiority transformation, followed by structures converted to grassland. The analysis of the case proves that the proposed process and method in this paper could achieve better results in the practical application. The experiment results also demonstrate that the proposed method could effectively obtain the dynamic change information of land use which is much helpful for land management and

  7. An in vitro lung model to assess true shunt fraction by multiple inert gas elimination.

    Directory of Open Access Journals (Sweden)

    Balamurugan Varadarajan

    Full Text Available The Multiple Inert Gas Elimination Technique, based on Micropore Membrane Inlet Mass Spectrometry, (MMIMS-MIGET has been designed as a rapid and direct method to assess the full range of ventilation-to-perfusion (V/Q ratios. MMIMS-MIGET distributions have not been assessed in an experimental setup with predefined V/Q-distributions. We aimed (I to construct a novel in vitro lung model (IVLM for the simulation of predefined V/Q distributions with five gas exchange compartments and (II to correlate shunt fractions derived from MMIMS-MIGET with preset reference shunt values of the IVLM. Five hollow-fiber membrane oxygenators switched in parallel within a closed extracorporeal oxygenation circuit were ventilated with sweep gas (V and perfused with human red cell suspension or saline (Q. Inert gas solution was infused into the perfusion circuit of the gas exchange assembly. Sweep gas flow (V was kept constant and reference shunt fractions (IVLM-S were established by bypassing one or more oxygenators with perfusate flow (Q. The derived shunt fractions (MM-S were determined using MIGET by MMIMS from the retention data. Shunt derived by MMIMS-MIGET correlated well with preset reference shunt fractions. The in vitro lung model is a convenient system for the setup of predefined true shunt fractions in validation of MMIMS-MIGET.

  8. Design and validation of inert homemade explosive simulants for ground penetrating radar

    Science.gov (United States)

    VanderGaast, Brian W.; McFee, John E.; Russell, Kevin L.; Faust, Anthony A.

    2015-05-01

    The Canadian Armed Forces (CAF) identified a requirement for inert simulants to act as improvised, or homemade, explosives (IEs) when training on, or evaluating, ground penetrating radar (GPR) systems commonly used in the detection of buried landmines and improvised explosive devices (IEDs). In response, Defence R and D Canada (DRDC) initiated a project to develop IE simulant formulations using commonly available inert materials. These simulants are intended to approximate the expected GPR response of common ammonium nitrate-based IEs, in particular ammonium nitrate/fuel oil (ANFO) and ammonium nitrate/aluminum (ANAl). The complex permittivity over the range of electromagnetic frequencies relevant to standard GPR systems was measured for bulk quantities of these three IEs that had been fabricated at DRDC Suffield Research Centre. Following these measurements, published literature was examined to find benign materials with both a similar complex permittivity, as well as other physical properties deemed desirable - such as low-toxicity, thermal stability, and commercial availability - in order to select candidates for subsequent simulant formulation. Suitable simulant formulations were identified for ANFO, with resulting complex permittivities measured to be within acceptable limits of target values. These IE formulations will now undergo end-user trials with CAF operators in order to confirm their utility. Investigations into ANAl simulants continues. This progress report outlines the development program, simulant design, and current validation results.

  9. Impact Strength of Composite Materials Based on EN AC-44200 Matrix Reinforced with Al2O3 Particles

    Directory of Open Access Journals (Sweden)

    Kurzawa A.

    2017-09-01

    Full Text Available The paper presents the results of research of impact strength of aluminum alloy EN AC-44200 based composite materials reinforced with alumina particles. The research was carried out applying the materials produced by the pressure infiltration method of ceramic preforms made of Al2O3 particles of 3-6μm with the liquid EN AC-44200 Al alloy. The research was aimed at determining the composite resistance to dynamic loads, taking into account the volume of reinforcing particles (from 10 to 40% by volume at an ambient of 23°C and at elevated temperatures to a maximum of 300°C. The results of this study were referred to the unreinforced matrix EN AC-44200 and to its hardness and tensile strength. Based on microscopic studies, an analysis and description of crack mechanics of the tested materials were performed. Structural analysis of a fracture surface, material structures under the crack surfaces of the matrix and cracking of the reinforcing particles were performed.

  10. Property-based design: optimization and characterization of polyvinyl alcohol (PVA) hydrogel and PVA-matrix composite for artificial cornea.

    Science.gov (United States)

    Jiang, Hong; Zuo, Yi; Zhang, Li; Li, Jidong; Zhang, Aiming; Li, Yubao; Yang, Xiaochao

    2014-03-01

    Each approach for artificial cornea design is toward the same goal: to develop a material that best mimics the important properties of natural cornea. Accordingly, the selection and optimization of corneal substitute should be based on their physicochemical properties. In this study, three types of polyvinyl alcohol (PVA) hydrogels with different polymerization degree (PVA1799, PVA2499 and PVA2699) were prepared by freeze-thawing techniques. After characterization in terms of transparency, water content, water contact angle, mechanical property, root-mean-square roughness and protein adsorption behavior, the optimized PVA2499 hydrogel with similar properties of natural cornea was selected as a matrix material for artificial cornea. Based on this, a biomimetic artificial cornea was fabricated with core-and-skirt structure: a transparent PVA hydrogel core, surrounding by a ringed PVA-matrix composite skirt that composed of graphite, Fe-doped nano hydroxyapatite (n-Fe-HA) and PVA hydrogel. Different ratio of graphite/n-Fe-HA can tune the skirt color from dark brown to light brown, which well simulates the iris color of Oriental eyes. Moreover, morphologic and mechanical examination showed that an integrated core-and-skirt artificial cornea was formed from an interpenetrating polymer network, no phase separation appeared on the interface between the core and the skirt.

  11. Investigate the plant biomass response to climate warming in permafrost ecosystem using matrix-based data assimilation

    Science.gov (United States)

    Lu, X.; Du, Z.; Schuur, E.; Luo, Y.

    2017-12-01

    Permafrost is one of the most vulnerable regions on the earth with over 40% world soil C represented in this region. Future climate warming potentially has a great impact on this region. On one hand, rising temperature accelerates permafrost soil thaw and release more C from land. On the other hand, warming may also increase the plant growing season length and therefore negatively feedback to climate change by increasing annual land C uptake. However, whether permafrost vegetation biomass change in response to warming can sequester more C has not been well understood. Manipulated air warming experiments reported that air warming has very limited impacts on grass land productivity and biomass growth in permafrost region [Mauritz et al., 2017]. It is hard to reveal the mechanisms behind the limited air warming response directly from experiment data. We employ a vegetation C cycle matrix model based on Community land model 4.5 (CLM4.5) and data assimilation technique to investigate how much do phenology and physiology processes contribute to the response respectively. Our results indicate phenology contributes the most in response to warming. The shift of vegetation parameter distributions after 2012 indicate vegetation acclimation may explain the modest response in plant biomass to air warming. The results suggest future model development need to take vegetation acclimation more seriously. The novel matrix-based model allows data assimilation to be conducted more efficiently. It provides more functional understanding of the models as well as the mechanism behind experiment data.

  12. A 2D/1D coupling neutron transport method based on the matrix MOC and NEM methods

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H.; Zheng, Y.; Wu, H.; Cao, L. [School of Nuclear Science and Technology, Xi' an Jiaotong University, No. 28, Xianning West Road, Xi' an, Shaanxi 710049 (China)

    2013-07-01

    A new 2D/1D coupling method based on the matrix MOC method (MMOC) and nodal expansion method (NEM) is proposed for solving the three-dimensional heterogeneous neutron transport problem. The MMOC method, used for radial two-dimensional calculation, constructs a response matrix between source and flux with only one sweep and then solves the linear system by using the restarted GMRES algorithm instead of the traditional trajectory sweeping process during within-group iteration for angular flux update. Long characteristics are generated by using the customization of commercial software AutoCAD. A one-dimensional diffusion calculation is carried out in the axial direction by employing the NEM method. The 2D and ID solutions are coupled through the transverse leakage items. The 3D CMFD method is used to ensure the global neutron balance and adjust the different convergence properties of the radial and axial solvers. A computational code is developed based on these theories. Two benchmarks are calculated to verify the coupling method and the code. It is observed that the corresponding numerical results agree well with references, which indicates that the new method is capable of solving the 3D heterogeneous neutron transport problem directly. (authors)

  13. Brain Mapping-Based Model of Δ(9)-Tetrahydrocannabinol Effects on Connectivity in the Pain Matrix.

    Science.gov (United States)

    Walter, Carmen; Oertel, Bruno G; Felden, Lisa; Kell, Christian A; Nöth, Ulrike; Vermehren, Johannes; Kaiser, Jochen; Deichmann, Ralf; Lötsch, Jörn

    2016-05-01

    Cannabinoids receive increasing interest as analgesic treatments. However, the clinical use of Δ(9)-tetrahydrocannabinol (Δ(9)-THC) has progressed with justified caution, which also owes to the incomplete mechanistic understanding of its analgesic effects, in particular its interference with the processing of sensory or affective components of pain. The present placebo-controlled crossover study therefore focused on the effects of 20 mg oral THC on the connectivity between brain areas of the pain matrix following experimental stimulation of trigeminal nocisensors in 15 non-addicted healthy volunteers. A general linear model (GLM) analysis identified reduced activations in the hippocampus and the anterior insula following THC administration. However, assessment of psychophysiological interaction (PPI) revealed that the effects of THC first consisted in a weakening of the interaction between the thalamus and the secondary somatosensory cortex (S2). From there, dynamic causal modeling (DCM) was employed to infer that THC attenuated the connections to the hippocampus and to the anterior insula, suggesting that the reduced activations in these regions are secondary to a reduction of the connectivity from somatosensory regions by THC. These findings may have consequences for the way THC effects are currently interpreted: as cannabinoids are increasingly considered in pain treatment, present results provide relevant information about how THC interferes with the affective component of pain. Specifically, the present experiment suggests that THC does not selectively affect limbic regions, but rather interferes with sensory processing which in turn reduces sensory-limbic connectivity, leading to deactivation of affective regions.

  14. Trivalent metal ions based on inorganic compounds with in vitro inhibitory activity of matrix metalloproteinase 13.

    Science.gov (United States)

    Wen, Hanyu; Qin, Yuan; Zhong, Weilong; Li, Cong; Liu, Xiang; Shen, Yehua

    2016-10-01

    Collagenase-3 (MMP-13) inhibitors have attracted considerable attention in recent years and have been developed as a therapeutic target for a variety of diseases, including cancer. Matrix metalloproteinases (MMPs) can be inhibited by a multitude of compounds, including hydroxamic acids. Studies have shown that materials and compounds containing trivalent metal ions, particularly potassium hexacyanoferrate (III) (K3[Fe(CN)6]), exhibit cdMMP-13 inhibitory potential with a half maximal inhibitory concentration (IC50) of 1.3μM. The target protein was obtained by refolding the recombinant histidine-tagged cdMMP-13 using size exclusion chromatography (SEC). The secondary structures of the refolded cdMMP-13 with or without metal ions were further analyzed via circular dichroism and the results indicate that upon binding with metal ions, an altered structure with increased domain stability was obtained. Furthermore, isothermal titration calorimetry (ITC) experiments demonstrated that K3[Fe(CN)6]is able to bind to MMP-13 and endothelial cell tube formation tests provide further evidence for this interaction to exhibit anti-angiogenesis potential. To the best of our knowledge, no previous report of an inorganic compound featuring a MMP-13 inhibitory activity has ever been reported in the literature. Our results demonstrate that K3[Fe(CN)6] is useful as a new effective and specific inhibitor for cdMMP-13 which may be of great potential for future drug screening applications. Copyright © 2016. Published by Elsevier Inc.

  15. Analysis method of beam pointing stability based on optical transmission matrix

    Science.gov (United States)

    Wang, Chuanchuan; Huang, PingXian; Li, Xiaotong; Cen, Zhaofen

    2016-10-01

    Quite a lot of factors will make effects on beam pointing stability of an optical system, Among them, the element tolerance is one of the most important and common factors. In some large laser systems, it will make final micro beams spot on the image plane deviate obviously. So it is essential for us to achieve effective and accurate analysis theoretically on element tolerance. In order to make the analysis of beam pointing stability convenient and theoretical, we consider transmission of a single chief ray rather than beams approximately to stand for the whole spot deviation. According to optical matrix, we also simplify this complex process of light transmission to multiplication of many matrices. So that we can set up element tolerance model, namely having mathematical expression to illustrate spot deviation in an optical system with element tolerance. In this way, we can realize quantitative analysis of beam pointing stability theoretically. In second half of the paper, we design an experiment to get the spot deviation in a multipass optical system caused by element tolerance, then we adjust the tolerance step by step and compare the results with the datum got from tolerance model, finally prove the correction of tolerance model successfully.

  16. A Global Sampling Based Image Matting Using Non-Negative Matrix Factorization

    Directory of Open Access Journals (Sweden)

    NAVEED ALAM

    2017-10-01

    Full Text Available Image matting is a technique in which a foreground is separated from the background of a given image along with the pixel wise opacity. This foreground can then be seamlessly composited in a different background to obtain a novel scene. This paper presents a global non-parametric sampling algorithm over image patches and utilizes a dimension reduction technique known as NMF (Non-Negative Matrix Factorization. Although some existing non-parametric approaches use large nearby foreground and background regions to sample patches but these approaches fail to take the whole image to sample patches. It is because of the high memory and computational requirements. The use of NMF in the proposed algorithm allows the dimension reduction which reduces the computational cost and memory requirement. The use of NMF also allow the proposed approach to use the whole foreground and background region in the image and reduces the patch complexity and help in efficient patch sampling. The use of patches not only allows the incorporation of the pixel colour but also the local image structure. The use of local structures in the image is important to estimate a high-quality alpha matte especially in the images which have regions containing high texture. The proposed algorithm is evaluated on the standard data set and obtained results are comparable to the state-of-the-art matting techniques

  17. A global sampling based image matting using non-negative matrix factorization

    International Nuclear Information System (INIS)

    Alam, N.; Sarim, M.; Shaikh, A.B.

    2017-01-01

    Image matting is a technique in which a foreground is separated from the background of a given image along with the pixel wise opacity. This foreground can then be seamlessly composited in a different background to obtain a novel scene. This paper presents a global non-parametric sampling algorithm over image patches and utilizes a dimension reduction technique known as NMF (Non-Negative Matrix Factorization). Although some existing non-parametric approaches use large nearby foreground and background regions to sample patches but these approaches fail to take the whole image to sample patches. It is because of the high memory and computational requirements. The use of NMF in the proposed algorithm allows the dimension reduction which reduces the computational cost and memory requirement. The use of NMF also allow the proposed approach to use the whole foreground and background region in the image and reduces the patch complexity and help in efficient patch sampling. The use of patches not only allows the incorporation of the pixel colour but also the local image structure. The use of local structures in the image is important to estimate a high-quality alpha matte especially in the images which have regions containing high texture. The proposed algorithm is evaluated on the standard data set and obtained results are comparable to the state-of-the-art matting techniques. (author)

  18. Carbon capture from natural gas using multi-walled CNTs based mixed matrix membranes.

    Science.gov (United States)

    Hussain, Abid; Farrukh, Sarah; Hussain, Arshad; Ayoub, Muhammad

    2017-12-05

    Most of the polymers and their blends, utilized in carbon capture membranes, are costly, but cellulose acetate (CA) being inexpensive is a lucrative choice. In this research, pure and mixed matrix membranes (MMMs) have been fabricated to capture carbon from natural gas. Polyethylene glycol (PEG) has been utilized in the fabrication of membranes to modify the chain flexibility of polymers. Multi-walled carbon nanotubes (MWCNTs) provide mechanical strength, thermal stability, an extra free path for CO 2 molecules and augment CO 2 /CH 4 selectivity. Membranes of pure CA, CA/PEG blend of different PEG concentrations (5%, 10%, 15%) and CA/PEG/MWCNTs blend of 10% PEG with different MWCNTs concentrations (5%, 10%, 15%) were prepared in acetone using solution casting techniques. Fabricated membranes were characterized using SEM, TGA and tensile testing. Permeation results revealed remarkable improvement in CO 2 /CH 4 selectivity. In single gas experiments, CO 2 /CH 4 selectivity is enhanced 8 times for pure membranes containing 10% PEG and 14 times for MMMs containing 10% MWCNTs. In mix gas experiments, the CO 2 /CH 4 selectivity is increased 13 times for 10% PEG and 18 times for MMMs with 10% MWCNTs. Fabricated MMMs have a tensile strength of 13 MPa and are more thermally stable than CA membranes.

  19. Dictionary Learning Based on Nonnegative Matrix Factorization Using Parallel Coordinate Descent

    Directory of Open Access Journals (Sweden)

    Zunyi Tang

    2013-01-01

    Full Text Available Sparse representation of signals via an overcomplete dictionary has recently received much attention as it has produced promising results in various applications. Since the nonnegativities of the signals and the dictionary are required in some applications, for example, multispectral data analysis, the conventional dictionary learning methods imposed simply with nonnegativity may become inapplicable. In this paper, we propose a novel method for learning a nonnegative, overcomplete dictionary for such a case. This is accomplished by posing the sparse representation of nonnegative signals as a problem of nonnegative matrix factorization (NMF with a sparsity constraint. By employing the coordinate descent strategy for optimization and extending it to multivariable case for processing in parallel, we develop a so-called parallel coordinate descent dictionary learning (PCDDL algorithm, which is structured by iteratively solving the two optimal problems, the learning process of the dictionary and the estimating process of the coefficients for constructing the signals. Numerical experiments demonstrate that the proposed algorithm performs better than the conventional nonnegative K-SVD (NN-KSVD algorithm and several other algorithms for comparison. What is more, its computational consumption is remarkably lower than that of the compared algorithms.

  20. Additive Manufacturing of SiC Based Ceramics and Ceramic Matrix Composites

    Science.gov (United States)

    Halbig, Michael Charles; Singh, Mrityunjay

    2015-01-01

    Silicon carbide (SiC) ceramics and SiC fiber reinforcedSiC ceramic matrix composites (SiCSiC CMCs) offer high payoff as replacements for metals in turbine engine applications due to their lighter weight, higher temperature capability, and lower cooling requirements. Additive manufacturing approaches can offer game changing technologies for the quick and low cost fabrication of parts with much greater design freedom and geometric complexity. Four approaches for developing these materials are presented. The first two utilize low cost 3D printers. The first uses pre-ceramic pastes developed as feed materials which are converted to SiC after firing. The second uses wood containing filament to print a carbonaceous preform which is infiltrated with a pre-ceramic polymer and converted to SiC. The other two approaches pursue the AM of CMCs. The first is binder jet SiC powder processing in collaboration with rp+m (Rapid Prototyping+Manufacturing). Processing optimization was pursued through SiC powder blending, infiltration with and without SiC nano powder loading, and integration of nanofibers into the powder bed. The second approach was laminated object manufacturing (LOM) in which fiber prepregs and laminates are cut to shape by a laser and stacked to form the desired part. Scanning electron microscopy was conducted on materials from all approaches with select approaches also characterized with XRD, TGA, and bend testing.

  1. Battery available power prediction of hybrid electric vehicle based on improved Dynamic Matrix Control algorithms

    Science.gov (United States)

    Wang, Limei; Cheng, Yong; Zou, Ju

    2014-09-01

    The core technology to any hybrid engine vehicle (HEV) is the design of energy management strategy (EMS). To develop a reasonable EMS, it is necessary to monitor the state of capacity, state of health and instantaneous available power of battery packs. A new method that linearizes RC equivalent circuit model and predicts battery available power according to original Dynamic Matrix Control algorithm is proposed. To verify the validity of the new algorithm, a bench test with lithium-ion battery cell and a HEV test with lithium-ion battery packs are carried out. The bench test results indicate that a single RC block equivalent circuit model could be used to describe the dynamic and the steady state characteristics of a battery under testing conditions. However, lacking of long time constant of RC modules, there is a sample deviation in the open-circuit voltage identified and that measured. The HEV testing results show that the battery voltage predicted is in good agreement with that measured, the maximum difference is within 3.7%. Fixing the time constant to a numeric value, satisfactory results can still be achieved. After setting a battery discharge cut-off voltage, the instantaneous available power of the battery can be predicted.

  2. A Mathematica-based CAL matrix-theory tutor for scientists and engineers

    Directory of Open Access Journals (Sweden)

    M. A. Kelmanson

    1993-12-01

    Full Text Available Under the TLTP initiative, the Mathematics Departments at Imperial College and Leeds University are jointly developing a CAL method directed at supplementing the level of mathematics of students entering science and engineering courses from diverse A-level (or equivalent backgrounds. The aim of the joint project is to maintain – even increase - the number of students enrolling on such first-year courses without lowering the courses' existing mathematical standards. A CAL tutor for matrix theory is presented in this paper, in the form of Mathematica Notebooks. This constitutes one of a list of specific A-level mathematics core options required by science and engineering departments. The module has been written so as to recognize students' errors and advise accordingly. Questions are generated randomly, at run time, in order to preclude copying between users. The module incorporates automated performance indicators so as to impinge minimally on existing staff resources. As an aid to other CAL authors considering the use of Mathematica Notebooks, idiosyncratic difficulties encountered within Mathematica Notebooks are catalogued and discussed in detail.

  3. Porous SiO{sub 2} nanofiber grafted novel bioactive glass–ceramic coating: A structural scaffold for uniform apatite precipitation and oriented cell proliferation on inert implant

    Energy Technology Data Exchange (ETDEWEB)

    Das, Indranee [Nano-Structured Materials Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata 700032 (India); De, Goutam, E-mail: gde@cgcri.res.in [Nano-Structured Materials Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata 700032 (India); Hupa, Leena [Johan Gadolin Process Chemistry Centre, Åbo Akademi University, FI-20500 Åbo (Finland); Vallittu, Pekka K. [Turku Clinical Biomaterials Centre—TCBC, University of Turku, FI-20520 Turku (Finland); Institute of Dentistry, University of Turku, Department of Biomaterials Science and City of Turku, Welfare Division, Turku (Finland)

    2016-05-01

    A composite bioactive glass–ceramic coating grafted with porous silica nanofibers was fabricated on inert glass to provide a structural scaffold favoring uniform apatite precipitation and oriented cell proliferation. The coating surfaces were investigated thoroughly before and after immersion in simulated body fluid. In addition, the proliferation behavior of fibroblast cells on the surface was observed for several culture times. The nanofibrous exterior of this composite bioactive coating facilitated homogeneous growth of flake-like carbonated hydroxyapatite layer within a short period of immersion. Moreover, the embedded porous silica nanofibers enhanced hydrophilicity which is required for proper cell adhesion on the surface. The cells proliferated well following a particular orientation on the entire coating by the assistance of nanofibrous scaffold-like structural matrix. This newly engineered composite coating was effective in creating a biological structural matrix favorable for homogeneous precipitation of calcium phosphate, and organized cell growth on the inert glass surface. - Highlights: • Fabricated porous SiO{sub 2} nanofibers grafted composite bioactive glass–ceramic coating on inert glass. • The newly engineered coating facilitates uniformly dense apatite precipitation. • Embedded porous silica nanofibers enhance hydrophilicity of the coated surface. • Cells proliferate well on the entire coating following a particular orientation by the assistance of nanofibers. • The coatings have potential to be used as biological scaffold on the surface of implants.

  4. Porous SiO2 nanofiber grafted novel bioactive glass–ceramic coating: A structural scaffold for uniform apatite precipitation and oriented cell proliferation on inert implant

    International Nuclear Information System (INIS)

    Das, Indranee; De, Goutam; Hupa, Leena; Vallittu, Pekka K.

    2016-01-01

    A composite bioactive glass–ceramic coating grafted with porous silica nanofibers was fabricated on inert glass to provide a structural scaffold favoring uniform apatite precipitation and oriented cell proliferation. The coating surfaces were investigated thoroughly before and after immersion in simulated body fluid. In addition, the proliferation behavior of fibroblast cells on the surface was observed for several culture times. The nanofibrous exterior of this composite bioactive coating facilitated homogeneous growth of flake-like carbonated hydroxyapatite layer within a short period of immersion. Moreover, the embedded porous silica nanofibers enhanced hydrophilicity which is required for proper cell adhesion on the surface. The cells proliferated well following a particular orientation on the entire coating by the assistance of nanofibrous scaffold-like structural matrix. This newly engineered composite coating was effective in creating a biological structural matrix favorable for homogeneous precipitation of calcium phosphate, and organized cell growth on the inert glass surface. - Highlights: • Fabricated porous SiO 2 nanofibers grafted composite bioactive glass–ceramic coating on inert glass. • The newly engineered coating facilitates uniformly dense apatite precipitation. • Embedded porous silica nanofibers enhance hydrophilicity of the coated surface. • Cells proliferate well on the entire coating following a particular orientation by the assistance of nanofibers. • The coatings have potential to be used as biological scaffold on the surface of implants.

  5. Multi-objective parametric optimization of Inertance type pulse tube refrigerator using response surface methodology and non-dominated sorting genetic algorithm

    Science.gov (United States)

    Rout, Sachindra K.; Choudhury, Balaji K.; Sahoo, Ranjit K.; Sarangi, Sunil K.

    2014-07-01

    The modeling and optimization of a Pulse Tube Refrigerator is a complicated task, due to its complexity of geometry and nature. The aim of the present work is to optimize the dimensions of pulse tube and regenerator for an Inertance-Type Pulse Tube Refrigerator (ITPTR) by using Response Surface Methodology (RSM) and Non-Sorted Genetic Algorithm II (NSGA II). The Box-Behnken design of the response surface methodology is used in an experimental matrix, with four factors and two levels. The diameter and length of the pulse tube and regenerator are chosen as the design variables where the rest of the dimensions and operating conditions of the ITPTR are constant. The required output responses are the cold head temperature (Tcold) and compressor input power (Wcomp). Computational fluid dynamics (CFD) have been used to model and solve the ITPTR. The CFD results agreed well with those of the previously published paper. Also using the results from the 1-D simulation, RSM is conducted to analyse the effect of the independent variables on the responses. To check the accuracy of the model, the analysis of variance (ANOVA) method has been used. Based on the proposed mathematical RSM models a multi-objective optimization study, using the Non-sorted genetic algorithm II (NSGA-II) has been performed to optimize the responses.

  6. Prediction of extracellular matrix stiffness in engineered heart valve tissues based on nonwoven scaffolds.

    Science.gov (United States)

    Engelmayr, George C; Sacks, Michael S

    2008-08-01

    The in vitro development of tissue engineered heart valves (TEHV) exhibiting appropriate structural and mechanical characteristics remains a significant challenge. An important step yet to be addressed is establishing the relationship between scaffold and extracellular matrix (ECM) mechanical properties. In the present study, a composite beam model accounting for nonwoven scaffold-ECM coupling and the transmural collagen concentration distribution was developed, and utilized to retrospectively estimate the ECM effective stiffness in TEHV specimens incubated under static and cyclic flexure conditions (Engelmayr Jr et~al. in Biomaterials 26(2):175-187 2005). The ECM effective stiffness was expressed as the product of the local collagen concentration and the collagen specific stiffness (i.e., stiffness/concentration), and was related to the overall TEHV effective stiffness via an empirically determined scaffold-ECM coupling parameter and measured transmural collagen concentration distributions. The scaffold-ECM coupling parameter was determined by flexural mechanical testing of polyacrylamide gels (i.e., ECM analogs) of variable stiffness and associated scaffold-polyacrylamide gel composites (i.e., engineered tissue analogs). The transmural collagen concentration distributions were quantified from fluorescence micrographs of picro-sirius red stained TEHV sections. As suggested by a previous structural model of the nonwoven scaffold (Engelmayr Jr and Sacks in J Biomech Eng 128(4):610-622, 2006), nonwoven scaffold-ECM composites did not follow a traditional rule of mixtures. The present study provided further evidence that the primary mode of reinforcement in nonwoven scaffold-ECM composites is an increase in the number fiber-fiber bonds with a concomitant increase in the effective stiffness of the spring-like fiber segments. Simulations of potential ECM deposition scenarios using the current model indicated that the present approach is sensitive to the specific time

  7. Valine-based biphenylsulphonamide matrix metalloproteinase inhibitors as tumor imaging agents

    Energy Technology Data Exchange (ETDEWEB)

    Oltenfreiter, Ruth [Faculty of Pharmaceutical Sciences, Department of Radiopharmacy, Ghent University, Harelbekestraat 72, 9000 Ghent (Belgium)]. E-mail: ruth.oltenfreiter@ugent.be; Staelens, Ludovicus [Faculty of Pharmaceutical Sciences, Department of Radiopharmacy, Ghent University, Harelbekestraat 72, 9000 Ghent (Belgium); Kersemans, Veerle [Faculty of Pharmaceutical Sciences, Department of Radiopharmacy, Ghent University, Harelbekestraat 72, 9000 Ghent (Belgium); Cornelissen, Bart [Faculty of Pharmaceutical Sciences, Department of Radiopharmacy, Ghent University, Harelbekestraat 72, 9000 Ghent (Belgium); Frankenne, Francis [Laboratory of Tumor and Developmental Biology, University of Liege, Sart-Tilman, Liege (Belgium); Foidart, Jean-Michel [Laboratory of Tumor and Developmental Biology, University of Liege, Sart-Tilman, Liege (Belgium); Wiele, Christophe van de [Division of Nuclear Medicine, Gent University Hospital, De Pintelaan 185, 9000 Gent (Belgium); Slegers, Guido [Faculty of Pharmaceutical Sciences, Department of Radiopharmacy, Ghent University, Harelbekestraat 72, 9000 Ghent (Belgium)

    2006-06-15

    Among matrix metalloproteinases (MMPs), the subfamily of gelatinases (MMP-2, MMP-9) is of particular interest due to their ability to degrade type IV collagen and other non-fibrillar collagen domains and proteins such as fibronectin and laminin. Whilst malignant cells often over-express various MMPs, the gelatinases have been most consistently detected in malignant tissues and associated with tumor growth, metastatic potential and angiogenesis. Radiosynthesis of carboxylic (1') and hydroxamic (2') MMPIs resulted in radiochemical yields of 70+/-5% (n=6) and 60+/-5% (n=4), respectively. Evaluation in A549-inoculated athymic mice showed a tumor uptake of 2.0+/-0.7%ID/g (3h p.i.), a tumor/blood ratio of 0.5 and a tumor/muscle ratio of 4.6 at 48hp.i. for 1'. For compound 2' a tumor uptake of 0.7+/-0.2%ID/g (3hp.i.), a tumor/blood ratio of 1.2 and a tumor/muscle ratio of 1.8 at 24hp.i. were observed. HPLC analysis of the blood (plasma) showed no dehalogenation or other metabolites of 1' 2hp.i. For compound 2', 65.4% of intact compound was found in the blood (plasma) and one polar metabolite (31%) was detected whereas in the tumor 91.8% of the accumulated activity was caused by intact compound and only 8.1% by the metabolite. Planar imaging, using a Toshiba GCA-9300A/hg SPECT camera, showed that tumor tissue could be visualized and that image quality improved by decreasing specific activity resulting in lower liver uptake, indicating some degree of saturable binding in the liver. In vivo evaluation of these radioiodinated carboxylic and hydroxamic MMP inhibitor tracers revealed that MMP inhibitors could have potential as tumor imaging agents, but that further research is necessary.

  8. Valine-based biphenylsulphonamide matrix metalloproteinase inhibitors as tumor imaging agents

    International Nuclear Information System (INIS)

    Oltenfreiter, Ruth; Staelens, Ludovicus; Kersemans, Veerle; Cornelissen, Bart; Frankenne, Francis; Foidart, Jean-Michel; Wiele, Christophe van de; Slegers, Guido

    2006-01-01

    Among matrix metalloproteinases (MMPs), the subfamily of gelatinases (MMP-2, MMP-9) is of particular interest due to their ability to degrade type IV collagen and other non-fibrillar collagen domains and proteins such as fibronectin and laminin. Whilst malignant cells often over-express various MMPs, the gelatinases have been most consistently detected in malignant tissues and associated with tumor growth, metastatic potential and angiogenesis. Radiosynthesis of carboxylic (1') and hydroxamic (2') MMPIs resulted in radiochemical yields of 70+/-5% (n=6) and 60+/-5% (n=4), respectively. Evaluation in A549-inoculated athymic mice showed a tumor uptake of 2.0+/-0.7%ID/g (3h p.i.), a tumor/blood ratio of 0.5 and a tumor/muscle ratio of 4.6 at 48hp.i. for 1'. For compound 2' a tumor uptake of 0.7+/-0.2%ID/g (3hp.i.), a tumor/blood ratio of 1.2 and a tumor/muscle ratio of 1.8 at 24hp.i. were observed. HPLC analysis of the blood (plasma) showed no dehalogenation or other metabolites of 1' 2hp.i. For compound 2', 65.4% of intact compound was found in the blood (plasma) and one polar metabolite (31%) was detected whereas in the tumor 91.8% of the accumulated activity was caused by intact compound and only 8.1% by the metabolite. Planar imaging, using a Toshiba GCA-9300A/hg SPECT camera, showed that tumor tissue could be visualized and that image quality improved by decreasing specific activity resulting in lower liver uptake, indicating some degree of saturable binding in the liver. In vivo evaluation of these radioiodinated carboxylic and hydroxamic MMP inhibitor tracers revealed that MMP inhibitors could have potential as tumor imaging agents, but that further research is necessary

  9. Water fog inerting of hydrogen-air mixtures

    International Nuclear Information System (INIS)

    Zalosh, R.G.; Bajpai, S.N.

    1982-01-01

    Laboratory tests have been conducted to determine the effects of water fog density, droplet diameter and temperature on the lower flammable limit (LFL) of hydrogen-air-steam mixtures. Five different fog nozzles were used to generate dense fogs with volume mean drop diameters ranging from 20 micro-meters to 115 micro-meters. At 20 0 C, these nozzles marginally raised the hydrogen LFL from 4.0 vol.% hydrogen to typically 4.8%, with one exceptional nozzle producing an LFL of 7.2%. At 50 0 C, the LFL in the presence of dense fog ranged from 5.0 to 7.9%, while at 70 0 C, the range was 5.9 to 8.5%. Fog densities required to achieve a given level of partial inerting increased with approximately the second power of average drop diameter, as predicted by a theoretical flame quenching analysis

  10. Crystallization of silicon nanoclusters with inert gas temperature control

    Science.gov (United States)

    Zhao, Junlei; Singh, Vidyadhar; Grammatikopoulos, Panagiotis; Cassidy, Cathal; Aranishi, Kengo; Sowwan, Mukhles; Nordlund, Kai; Djurabekova, Flyura

    2015-01-01

    We analyze the fundamental process of crystallization of silicon nanoclusters by means of molecular dynamics simulations, complemented by magnetron-sputter inert gas condensation, which was used to synthesize polycrystalline silicon nanoclusters with good size control. We utilize two well-established Si interatomic potentials: the Stillinger-Weber and the Tersoff III. Both the simulations and experiments show that upon cooling down by an Ar gas thermal bath, initially liquid, free-standing Si nanocluster can grow multiple crystal nuclei, which drive their transition into polycrystalline solid nanoclusters. The simulations allow detailed analysis of the mechanism, and show that the crystallization temperature is size-dependent and that the probability of crystalline phase nucleation depends on the highest temperature the cluster reaches during the initial condensation and the cooling rate after it.

  11. Wigner's infinite spin representations and inert matter

    Energy Technology Data Exchange (ETDEWEB)

    Schroer, Bert [CBPF, Rio de Janeiro (Brazil); Institut fuer Theoretische Physik FU-Berlin, Berlin (Germany)

    2017-06-15

    Positive energy ray representations of the Poincare group are naturally subdivided into three classes according to their mass and spin content: m > 0, m = 0 finite helicity and m = 0 infinite spin. For a long time the localization properties of the massless infinite spin class remained unknown, until it became clear that such matter does not permit compact spacetime localization and its generating covariant fields are localized on semi-infinite space-like strings. Using a new perturbation theory for higher spin fields we present arguments which support the idea that infinite spin matter cannot interact with normal matter and we formulate conditions under which this also could happen for finite spin s > 1 fields. This raises the question of a possible connection between inert matter and dark matter. (orig.)

  12. Inert scalars and vacuum metastability around the electroweak scale

    Energy Technology Data Exchange (ETDEWEB)

    Świeżewska, Bogumiła [Faculty of Physics, University of Warsaw,Pasteura 5, 02-093 Warsaw (Poland)

    2015-07-22

    We analyse effective potential around the electroweak (EW) scale in the Standard Model (SM) extended with a heavy scalar doublet. We show that the additional scalars can have a strong impact on vacuum stability. Although the additional heavy scalars may improve the behaviour of running Higgs self-coupling at large field values, we prove that they can destabilise the vacuum due to EW-scale effects. A new EW symmetry conserving minimum of the effective potential can appear rendering the electroweak symmetry breaking (EWSB) minimum meta- or unstable. However, for the case of the inert doublet model (IDM) with a 125 GeV Higgs boson we demonstrate that the parameter space region where the vacuum is meta- or unstable cannot be reconciled with the constraints from perturbative unitarity, electroweak precision tests (EWPT) and dark matter relic abundance measurements.

  13. Effective Factors in Severity of Traffic Accident-Related Traumas; an Epidemiologic Study Based on the Haddon Matrix

    Directory of Open Access Journals (Sweden)

    Kambiz Masoumi

    2016-04-01

    Full Text Available Introduction: Traffic accidents are the 8th cause of mortality in different countries and are expected to rise to the 3rd rank by 2020. Based on the Haddon matrix numerous factors such as environment, host, and agent can affect the severity of traffic-related traumas. Therefore, the present study aimed to evaluate the effective factors in severity of these traumas based on Haddon matrix. Methods: In the present 1-month cross-sectional study, all the patients injured in traffic accidents, who were referred to the ED of Imam Khomeini and Golestan Hospitals, Ahvaz, Iran, during March 2013 were evaluated. Based on the Haddon matrix, effective factors in accident occurrence were defined in 3 groups of host, agent, and environment. Demographic data of the patients and data regarding Haddon risk factors were extracted and analyzed using SPSS version 20. Results: 700 injured people with the mean age of 29.66 ± 12.64 years (3-82 were evaluated (92.4% male. Trauma mechanism was car-pedestrian in 308 (44% of the cases and car-motorcycle in 175 (25%. 610 (87.1% cases were traffic accidents and 371 (53% occurred in the time between 2 pm and 8 pm. Violation of speed limit was the most common violation with 570 (81.4% cases, followed by violation of right-of-way in 57 (8.1% patients. 59.9% of the severe and critical injuries had occurred on road accidents, while 61.3% of the injuries caused by traffic accidents were mild to moderate (p < 0.001. The most common mechanisms of trauma for critical injuries were rollover (72.5%, motorcycle-pedestrian (23.8%, and car-motorcycle (13.14% accidents (p < 0.001. Conclusion: Based on the results of the present study, the most important effective factors in severity of traffic accident-related traumas were age over 50, not using safety tools, and undertaking among host-related factors; insufficient environment safety, road accidents and time between 2 pm and 8 pm among environmental factors; and finally, rollover, car

  14. Structural Characteristics and Magnetic Properties of Al2O3 Matrix-Based Co-Cermet Nanogranular Films

    Directory of Open Access Journals (Sweden)

    Giap Van Cuong

    2015-01-01

    Full Text Available Magnetic micro- and nanogranular materials prepared by different methods have been used widely in studies of magnetooptical response. However, among them there seems to be nothing about magnetic nanogranular thin films prepared by a rf cosputtering technique for both metals and insulators till now. This paper presented and discussed preparation, structural characteristics, and magnetic properties of alumina (Al2O3 matrix-based granular Co-cermet thin films deposited by means of the cosputtering technique for both Co and Al2O3. By varying the ferromagnetic (Co atomic fraction, x, from 0.04 to 0.63, several dominant features of deposition for these thin films were shown. Structural characteristics by X-ray diffraction confirmed a cermet-type structure for these films. Furthermore, magnetic behaviours presented a transition from paramagnetic- to superparamagnetic- and then to ferromagnetic-like properties, indicating agglomeration and growth following Co components of Co clusters or nanoparticles. These results show a typical granular Co-cermet feature for the Co-Al2O3 thin films prepared, in which Co magnetic nanogranules are dispersed in a ceramic matrix. Such nanomaterials can be applied suitably for our investigations in future on the magnetooptical responses of spinplasmonics.

  15. Design of an optimized biomixture for the degradation of carbofuran based on pesticide removal and toxicity reduction of the matrix.

    Science.gov (United States)

    Chin-Pampillo, Juan Salvador; Ruiz-Hidalgo, Karla; Masís-Mora, Mario; Carazo-Rojas, Elizabeth; Rodríguez-Rodríguez, Carlos E

    2015-12-01

    Pesticide biopurification systems contain a biologically active matrix (biomixture) responsible for the accelerated elimination of pesticides in wastewaters derived from pest control in crop fields. Biomixtures have been typically prepared using the volumetric composition 50:25:25 (lignocellulosic substrate/humic component/soil); nonetheless, formal composition optimization has not been performed so far. Carbofuran is an insecticide/nematicide of high toxicity widely employed in developing countries. Therefore, the composition of a highly efficient biomixture (composed of coconut fiber, compost, and soil, FCS) for the removal of carbofuran was optimized by means of a central composite design and response surface methodology. The volumetric content of soil and the ratio coconut fiber/compost were used as the design variables. The performance of the biomixture was assayed by considering the elimination of carbofuran, the mineralization of (14)C-carbofuran, and the residual toxicity of the matrix, as response variables. Based on the models, the optimal volumetric composition of the FCS biomixture consists of 45:13:42 (coconut fiber/compost/soil), which resulted in minimal residual toxicity and ∼99% carbofuran elimination after 3 days. This optimized biomixture considerably differs from the standard 50:25:25 composition, which remarks the importance of assessing the performance of newly developed biomixtures during the design of biopurification systems.

  16. Performance optimization of Sparse Matrix-Vector Multiplication for multi-component PDE-based applications using GPUs

    KAUST Repository

    Abdelfattah, Ahmad

    2016-05-23

    Simulations of many multi-component PDE-based applications, such as petroleum reservoirs or reacting flows, are dominated by the solution, on each time step and within each Newton step, of large sparse linear systems. The standard solver is a preconditioned Krylov method. Along with application of the preconditioner, memory-bound Sparse Matrix-Vector Multiplication (SpMV) is the most time-consuming operation in such solvers. Multi-species models produce Jacobians with a dense block structure, where the block size can be as large as a few dozen. Failing to exploit this dense block structure vastly underutilizes hardware capable of delivering high performance on dense BLAS operations. This paper presents a GPU-accelerated SpMV kernel for block-sparse matrices. Dense matrix-vector multiplications within the sparse-block structure leverage optimization techniques from the KBLAS library, a high performance library for dense BLAS kernels. The design ideas of KBLAS can be applied to block-sparse matrices. Furthermore, a technique is proposed to balance the workload among thread blocks when there are large variations in the lengths of nonzero rows. Multi-GPU performance is highlighted. The proposed SpMV kernel outperforms existing state-of-the-art implementations using matrices with real structures from different applications. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  17. Structure of Composite Based on Polyheteroarylene Matrix and ZrO2 Nanostars Investigated by Quantitative Nanomechanical Mapping

    Directory of Open Access Journals (Sweden)

    Maria P. Sokolova

    2017-07-01

    Full Text Available It is known that structure of the interface between inorganic nanoparticles and polymers significantly influences properties of a polymer–inorganic composite. At the same time, amount of experimental researches on the structure and properties of material near the inorganic-polymer interface is low. In this work, we report for the first time the investigation of nanomechanical properties and maps of adhesion of material near the inorganic-polymer interface for the polyheteroarylene nanocomposites based on semi-crystalline poly[4,4′-bis (4″-aminophenoxydiphenyl]imide 1,3-bis (3′,4-dicarboxyphenoxy benzene, modified by ZrO2 nanostars. Experiments were conducted using quantitative nanomechanical mapping (QNM mode of atomic force microscopy (AFM at the surface areas where holes were formed after falling out of inorganic particles. It was found that adhesion of AFM cantilever to the polymer surface is higher inside the hole than outside. This can be attributed to the presence of polar groups near ZrO2 nanoparticle. QNM measurements revealed that polymer matrix has increased rigidity in the vicinity of the nanoparticles. Influence of ZrO2 nanoparticles on the structure and thermal properties of semi-crystalline polyheteroarylene matrix was studied with wide-angle X-ray scattering, scanning electron microscopy, and differential scanning calorimetry.

  18. Super-resolution reconstruction of 4D-CT lung data via patch-based low-rank matrix reconstruction

    Science.gov (United States)

    Fang, Shiting; Wang, Huafeng; Liu, Yueliang; Zhang, Minghui; Yang, Wei; Feng, Qianjin; Chen, Wufan; Zhang, Yu

    2017-10-01

    Lung 4D computed tomography (4D-CT), which is a time-resolved CT data acquisition, performs an important role in explicitly including respiratory motion in treatment planning and delivery. However, the radiation dose is usually reduced at the expense of inter-slice spatial resolution to minimize radiation-related health risk. Therefore, resolution enhancement along the superior-inferior direction is necessary. In this paper, a super-resolution (SR) reconstruction method based on a patch low-rank matrix reconstruction is proposed to improve the resolution of lung 4D-CT images. Specifically, a low-rank matrix related to every patch is constructed by using a patch searching strategy. Thereafter, the singular value shrinkage is employed to recover the high-resolution patch under the constraints of the image degradation model. The output high-resolution patches are finally assembled to output the entire image. This method is extensively evaluated using two public data sets. Quantitative analysis shows that the proposed algorithm decreases the root mean square error by 9.7%-33.4% and the edge width by 11.4%-24.3%, relative to linear interpolation, back projection (BP) and Zhang et al’s algorithm. A new algorithm has been developed to improve the resolution of 4D-CT. In all experiments, the proposed method outperforms various interpolation methods, as well as BP and Zhang et al’s method, thus indicating the effectivity and competitiveness of the proposed algorithm.

  19. Study on the Dynamics of Laser Gyro Strapdown Inertial Measurement Unit System Based on Transfer Matrix Method for Multibody System

    Directory of Open Access Journals (Sweden)

    Gangli Chen

    2013-01-01

    Full Text Available The dynamic test precision of the strapdown inertial measurement unit (SIMU is the basis of estimating accurate motion of various vehicles such as warships, airplanes, spacecrafts, and missiles. So, it is paid great attention in the above fields to increase the dynamic precision of SIMU by decreasing the vibration of the vehicles acting on the SIMU. In this paper, based on the transfer matrix method for multibody system (MSTMM, the multibody system dynamics model of laser gyro strapdown inertial measurement unit (LGSIMU is developed; the overall transfer equation of the system is deduced automatically. The computational results show that the frequency response function of the LGSIMU got by the proposed method and Newton-Euler method have good agreements. Further, the vibration reduction performance and the attitude error responses under harmonic and random excitations are analyzed. The proposed method provides a powerful technique for studying dynamics of LGSIMU because of using MSTMM and its following features: without the global dynamics equations of the system, high programming, low order of system matrix, and high computational speed.

  20. Rigorous proof of fuzzy error propagation with matrix-based LCI

    NARCIS (Netherlands)

    Heijungs, Reinout; Tan, Raymond R.

    2010-01-01

    Background, aim, and scope: Propagation of parametric uncertainty in life cycle inventory (LCI) models is usually performed based on probabilistic Monte Carlo techniques. However, alternative approaches using interval or fuzzy numbers have been proposed based on the argument that these provide a

  1. Matrix calculus

    CERN Document Server

    Bodewig, E

    1959-01-01

    Matrix Calculus, Second Revised and Enlarged Edition focuses on systematic calculation with the building blocks of a matrix and rows and columns, shunning the use of individual elements. The publication first offers information on vectors, matrices, further applications, measures of the magnitude of a matrix, and forms. The text then examines eigenvalues and exact solutions, including the characteristic equation, eigenrows, extremum properties of the eigenvalues, bounds for the eigenvalues, elementary divisors, and bounds for the determinant. The text ponders on approximate solutions, as well

  2. Multiple inert gas elimination technique by micropore membrane inlet mass spectrometry--a comparison with reference gas chromatography.

    Science.gov (United States)

    Kretzschmar, Moritz; Schilling, Thomas; Vogt, Andreas; Rothen, Hans Ulrich; Borges, João Batista; Hachenberg, Thomas; Larsson, Anders; Baumgardner, James E; Hedenstierna, Göran

    2013-10-15

    The mismatching of alveolar ventilation and perfusion (VA/Q) is the major determinant of impaired gas exchange. The gold standard for measuring VA/Q distributions is based on measurements of the elimination and retention of infused inert gases. Conventional multiple inert gas elimination technique (MIGET) uses gas chromatography (GC) to measure the inert gas partial pressures, which requires tonometry of blood samples with a gas that can then be injected into the chromatograph. The method is laborious and requires meticulous care. A new technique based on micropore membrane inlet mass spectrometry (MMIMS) facilitates the handling of blood and gas samples and provides nearly real-time analysis. In this study we compared MIGET by GC and MMIMS in 10 piglets: 1) 3 with healthy lungs; 2) 4 with oleic acid injury; and 3) 3 with isolated left lower lobe ventilation. The different protocols ensured a large range of normal and abnormal VA/Q distributions. Eight inert gases (SF6, krypton, ethane, cyclopropane, desflurane, enflurane, diethyl ether, and acetone) were infused; six of these gases were measured with MMIMS, and six were measured with GC. We found close agreement of retention and excretion of the gases and the constructed VA/Q distributions between GC and MMIMS, and predicted PaO2 from both methods compared well with measured PaO2. VA/Q by GC produced more widely dispersed modes than MMIMS, explained in part by differences in the algorithms used to calculate VA/Q distributions. In conclusion, MMIMS enables faster measurement of VA/Q, is less demanding than GC, and produces comparable results.

  3. [The randomized controlled trial of the prison-based Japanese Matrix Program (J-MAT) for methamphetamine abusers].

    Science.gov (United States)

    Harada, Takayuki

    2012-12-01

    Methamphetamine use is subject to severe criminal punishment in Japan and approximately 22% of the prison population were confined for violations of the stimulants control law in 2009. Although the high recidivism rate is also a problem, no systematic treatment has been conducted in prison. Therefore, the development of the prison-based treatment program is necessary. In this study, the prison-based program was developed based on the Matrix Model, which is the cognitive-behavioral treatment for amphetamine users developed in the US. The program was tailored in order to address the treatment needs of the Japanese amphetamine users considering Japanese culture and the prison climate. The randomized controlled trial was conducted in order to evaluate the effectiveness the Japanese Matrix program (J-MAT). 60 prisoners were randomly assigned either to the J-MAT or the control groups and those who in the J-MAT group received the program once a week for 12 weeks. The abstinence rate could not be used as the outcome measure because the participants could not be followed after the release from prison due to the legal reasons. Therefore, the psychological variables including coping skills, self-efficacy and motivation were used as outcome measures, which are considered as the important predictive factors of abstinence. 93.3% of the J-MAT participants completed the program. The coping skills of the treated prisoners were improved significantly after treatment comparing to the control (F (1, 27) = 9.03, p < .001), however other psychological variables were not significantly improved. The results suggested the effectiveness of the J-MAT because both treatment completion and coping skills are powerful predictors of abstinence. Further study is required and in which the participants should be followed after the completion of treatment in order to compare the relapse rates between the groups and to measure the long-term treatment gain.

  4. Asymptotic analysis of stationary adiabatic premixed flames in porous inert media

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Fernando M.; Oliveira, Amir A.M. [Departamento de Engenharia Mecanica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis, SC (Brazil); Fachini, Fernando F. [Instituto Nacional de Pesquisas Espaciais, 12630-000 Cachoeira Paulista, SP (Brazil)

    2009-01-15

    The structure of adiabatic premixed flames within porous inert media is investigated using the asymptotic expansion method. For this, the flame structure is divided into three characteristic length scales. The two innermost length scales, the gas-phase diffusion length scale and the reaction length scale, are the same scales defined in the classical premixed flame structure analysis. The outermost length scale, the solid-phase diffusion length scale, is related to the heat conduction in the porous matrix. The differences among these three characteristic length-scales result in large temperature differences between the phases and justify the application of asymptotic expansions to determine an approximate (analytical) solution. Since the main focus of this work is the examination of the processes in the outer and the first inner regions, the simplest kinetic mechanism of one global step is adopted to represent the fuel and oxygen consumption. Then, the description of the reaction zone is obtained using the large activation energy asymptotic method. The description of the problem of the order of the gas-phase length scale is obtained using the boundary layer expansion. This work evaluates the influence of the equivalence ratio, the ratio of the solid to the gas thermal conductivities, the porosity of the medium and the fuel Lewis number on such flames. A parameter that universalizes the flame properties is then identified and discussed. (author)

  5. Asymptotic analysis of stationary adiabatic premixed flames in porous inert media

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Fernando M.; Oliveira, Amir A.M. [Departamento de Engenharia Mecanica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis, SC (Brazil); Fachini, Fernando F. [Instituto Nacional de Pesquisas Espaciais, 12630-000 Cachoeira Paulista, SP (Brazil)

    2008-11-15

    The structure of adiabatic premixed flames within porous inert media is investigated using the asymptotic expansion method. For this, the flame structure is divided into three characteristic length scales. The two innermost length scales, the gas-phase diffusion length scale and the reaction length scale, are the same scales defined in the classical premixed flame structure analysis. The outermost length scale, the solid-phase diffusion length scale, is related to the heat conduction in the porous matrix. The differences among these three characteristic length-scales result in large temperature differences between the phases and justify the application of asymptotic expansions to determine an approximate (analytical) solution. Since the main focus of this work is the examination of the processes in the outer and the first inner regions, the simplest kinetic mechanism of one global step is adopted to represent the fuel and oxygen consumption. Then, the description of the reaction zone is obtained using the large activation energy asymptotic method. The description of the problem of the order of the gas-phase length scale is obtained using the boundary layer expansion. This work evaluates the influence of the equivalence ratio, the ratio of the solid to the gas thermal conductivities, the porosity of the medium and the fuel Lewis number on such flames. A parameter that universalizes the flame properties is then identified and discussed. (author)

  6. Sparse matrix decompositions for clustering

    OpenAIRE

    Blumensath, Thomas

    2014-01-01

    Clustering can be understood as a matrix decomposition problem, where a feature vector matrix is represented as a product of two matrices, a matrix of cluster centres and a matrix with sparse columns, where each column assigns individual features to one of the cluster centres. This matrix factorisation is the basis of classical clustering methods, such as those based on non-negative matrix factorisation but can also be derived for other methods, such as k-means clustering. In this paper we de...

  7. Physics-based Modeling of Foreign Object Damage in Ceramic Matrix Composites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this Phase I SBIR, Firehole Technologies will develop proof-of-concept modeling framework for a multiscale physics-based modeling tool for predicting foreign...

  8. Matrix removal in state of the art sample preparation methods for serum by charged aerosol detection and metabolomics-based LC-MS.

    Science.gov (United States)

    Schimek, Denise; Francesconi, Kevin A; Mautner, Anton; Libiseller, Gunnar; Raml, Reingard; Magnes, Christoph

    2016-04-07

    Investigations into sample preparation procedures usually focus on analyte recovery with no information provided about the fate of other components of the sample (matrix). For many analyses, however, and particularly those using liquid chromatography-mass spectrometry (LC-MS), quantitative measurements are greatly influenced by sample matrix. Using the example of the drug amitriptyline and three of its metabolites in serum, we performed a comprehensive investigation of nine commonly used sample clean-up procedures in terms of their suitability for preparing serum samples. We were monitoring the undesired matrix compounds using a combination of charged aerosol detection (CAD), LC-CAD, and a metabolomics-based LC-MS/MS approach. In this way, we compared analyte recovery of protein precipitation-, liquid-liquid-, solid-phase- and hybrid solid-phase extraction methods. Although all methods provided acceptable recoveries, the highest recovery was obtained by protein precipitation with acetonitrile/formic acid (amitriptyline 113%, nortriptyline 92%, 10-hydroxyamitriptyline 89%, and amitriptyline N-oxide 96%). The quantification of matrix removal by LC-CAD showed that the solid phase extraction method (SPE) provided the lowest remaining matrix load (48-123 μg mL(-1)), which is a 10-40 fold better matrix clean-up than the precipitation- or hybrid solid phase extraction methods. The metabolomics profiles of eleven compound classes, comprising 70 matrix compounds showed the trends of compound class removal for each sample preparation strategy. The collective data set of analyte recovery, matrix removal and matrix compound profile was used to assess the effectiveness of each sample preparation method. The best performance in matrix clean-up and practical handling of small sample volumes was showed by the SPE techniques, particularly HLB SPE. CAD proved to be an effective tool for revealing the considerable differences between the sample preparation methods. This detector can

  9. Matrix superpotentials

    Science.gov (United States)

    Nikitin, Anatoly G.; Karadzhov, Yuri

    2011-07-01

    We present a collection of matrix-valued shape invariant potentials which give rise to new exactly solvable problems of SUSY quantum mechanics. It includes all irreducible matrix superpotentials of the generic form W=kQ+\\frac{1}{k} R+P, where k is a variable parameter, Q is the unit matrix multiplied by a real-valued function of independent variable x, and P and R are the Hermitian matrices depending on x. In particular, we recover the Pron'ko-Stroganov 'matrix Coulomb potential' and all known scalar shape invariant potentials of SUSY quantum mechanics. In addition, five new shape invariant potentials are presented. Three of them admit a dual shape invariance, i.e. the related Hamiltonians can be factorized using two non-equivalent superpotentials. We find discrete spectrum and eigenvectors for the corresponding Schrödinger equations and prove that these eigenvectors are normalizable.

  10. The Effect of Sterile Acellular Dermal Matrix Use on Complication Rates in Implant-Based Immediate Breast Reconstructions

    Directory of Open Access Journals (Sweden)

    Jun Ho Lee

    2016-11-01

    Full Text Available BackgroundThe use of acellular dermal matrix (ADM in implant-based immediate breast reconstruction has been increasing. The current ADMs available for breast reconstruction are offered as aseptic or sterile. No published studies have compared aseptic and sterile ADM in implant-based immediate breast reconstruction. The authors performed a retrospective study to evaluate the outcomes of aseptic versus sterile ADM in implant-based immediate breast reconstruction.MethodsImplant-based immediate breast reconstructions with ADM conducted between April 2013 and January 2016 were included. The patients were divided into 2 groups: the aseptic ADM (AlloDerm group and the sterile ADM (MegaDerm group. Archived records were reviewed for demographic data and postoperative complication types and frequencies. The complications included were infection, flap necrosis, capsular contracture, seroma, hematoma, and explantation for any cause.ResultsTwenty patients were reconstructed with aseptic ADM, and 68 patients with sterile ADM. Rates of infection (15.0% vs. 10.3%, flap necrosis (5.0% vs. 7.4%, capsular contracture (20.0% vs. 14.7%, seroma (10.0% vs. 14.7%, hematoma (0% vs. 1.5%, and explantation (10.0% vs. 8.8% were not significantly different in the 2 groups.ConclusionsSterile ADM did not provide better results regarding infectious complications than aseptic ADM in implant-based immediate breast reconstruction.

  11. General beam position controlling method for 3D optical systems based on the method of solving ray matrix equations

    Science.gov (United States)

    Chen, Meixiong; Yuan, Jie; Long, Xingwu; Kang, Zhenglong; Wang, Zhiguo; Li, Yingying

    2013-12-01

    A general beam position controlling method for 3D optical systems based on the method of solving ray matrix equations has been proposed in this paper. As a typical 3D optical system, nonplanar ring resonator of Zero-Lock Laser Gyroscopes has been chosen as an example to show its application. The total mismatching error induced by Faraday-wedge in nonplanar ring resonator has been defined and eliminated quite accurately with the error less than 1 μm. Compared with the method proposed in Ref. [14], the precision of the beam position controlling has been improved by two orders of magnitude. The novel method can be used to implement automatic beam position controlling in 3D optical systems with servo circuit. All those results have been confirmed by related alignment experiments. The results in this paper are important for beam controlling, ray tracing, cavity design and alignment in 3D optical systems.

  12. Electrochemical effect of coating layer on the separator based on PVdF and PE non-woven matrix

    Science.gov (United States)

    Lee, Yong Min; Choi, Nam-Soon; Lee, Je An; Seol, Wan-Ho; Cho, Ki-Yun; Jung, Ho-Young; Kim, Jun-Woo; Park, Jung-Ki

    The coated separator was prepared by coating poly(vinyl acetate) (PVAc) on the surface of the novel separator based on poly(vinylidene fluoride) (PVdF) and polyethylene (PE) non-woven matrix. The ionic conductivity of the coated separator was 1.1 × 10 -3 S cm -1 at 25 °C, a little higher than that of bare separator. The coated separator showed smoother surface morphology and better adhesion property toward electrodes, and thereby it resulted in lower total resistance than the bare separator. The discharge capacity of the unit cell with coated separator at C/2 rate was maintained at about 84% of the theoretical capacity, which is quite higher than that of the unit cell with the bare separator.

  13. Noise-immune complex correlation for optical coherence angiography based on standard and Jones matrix optical coherence tomography.

    Science.gov (United States)

    Makita, Shuichi; Kurokawa, Kazuhiro; Hong, Young-Joo; Miura, Masahiro; Yasuno, Yoshiaki

    2016-04-01

    This paper describes a complex correlation mapping algorithm for optical coherence angiography (cmOCA). The proposed algorithm avoids the signal-to-noise ratio dependence and exhibits low noise in vasculature imaging. The complex correlation coefficient of the signals, rather than that of the measured data are estimated, and two-step averaging is introduced. Algorithms of motion artifact removal based on non perfusing tissue detection using correlation are developed. The algorithms are implemented with Jones-matrix OCT. Simultaneous imaging of pigmented tissue and vasculature is also achieved using degree of polarization uniformity imaging with cmOCA. An application of cmOCA to in vivo posterior human eyes is presented to demonstrate that high-contrast images of patients' eyes can be obtained.

  14. Hyaluronic acid based hydroxamate and conjugates with biologically active amines: In vitro effect on matrix metalloproteinase-2.

    Science.gov (United States)

    Ponedel'kina, Irina Yu; Gaskarova, Aigul R; Khaybrakhmanova, Elvira A; Lukina, Elena S; Odinokov, Victor N

    2016-06-25

    In this study, water soluble hyaluronic acid (HA) based hydroxamate and conjugates with biologically active amines and hydrazides such as p- and o-aminophenols, anthranilic, 4- and 5-aminosalicylic acids, nicotinic, N-benzylnicotinic and isonicotinic hydrazides, p-aminobenzenesulfonamide (Streptocide), p-aminobenzoic acid diethylaminoethyl ester (Procaine), and 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one (4-aminoantipyrene) were examined as matrix metalloproteinase-2 inhibitors (MMPIs). In a dose of 0.27-270μM, the most efficient MMPIs were HA conjugates with o-aminophenol=4-aminoantipyrine>4-aminosalicylic acid>5-aminosalicylic acid. Conjugates with Streptocide, Procaine and HA hydroxamate showed 40-50% inhibitory effect at all used concentrations. Conjugates with anthranilic acid and isonicotinic hydrazide (Isoniazid) in a dose of 0.27μM inhibited enzyme activity by ∼70%, but with the concentration increase their inhibitory effect was decreased. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. An expert-based job exposure matrix for large scale epidemiologic studies of primary hip and knee osteoarthritis

    DEFF Research Database (Denmark)

    Rubak, Tine Steen; Svendsen, Susanne Wulff; Andersen, Johan Hviid

    2014-01-01

    in population studies of the work-relatedness of hip and knee osteoarthritis. METHODS: Based on all 2227 occupational titles in the Danish version of the International Standard Classification of Occupations (D-ISCO 88), we constructed 121 job groups comprising occupational titles with expected homogeneous......BACKGROUND: When conducting large scale epidemiologic studies, it is a challenge to obtain quantitative exposure estimates, which do not rely on self-report where estimates may be influenced by symptoms and knowledge of disease status. In this study we developed a job exposure matrix (JEM) for use...... exposure patterns in addition to a minimally exposed job group, which was not included in the JEM. The job groups were allocated the mean value of five experts' ratings of daily duration (hours/day) of standing/walking, kneeling/squatting, and whole-body vibration as well as total load lifted (kg...

  16. Electrochemical study of oxidation process of promethazine using sensor based on carbon nanotubes paste containing immobilized DNA on inorganic matrix

    Directory of Open Access Journals (Sweden)

    João Paulo Marco

    2014-10-01

    Full Text Available In the present work the voltammetric behavior and the oxidation process of promethazine (PHZ in electrochemical sensor based on carbon nanotubes paste containing DNA immobilized on the inorganic matrix prepared by sol-gel process (SiO2/Al2O3/Nb2O5. The method of Laviron verified that the system is irreversible and high speed of electron transfer between the electrode and DNA. The study of the oxidation of PHZ and influence of pH showed slope of 0.054 V / pH (near the nernstian system: 0.0592 V / pH suggesting that it involves the transfer of two protons and two electrons.

  17. Power Decoupling Method Based on the Diagonal Compensating Matrix for VSG-Controlled Parallel Inverters in the Microgrid

    Directory of Open Access Journals (Sweden)

    Bin Li

    2017-12-01

    Full Text Available The thought of the virtual synchronous generator (VSG for controlling the grid-connected inverters and providing virtual inertia to the microgrid is emerging as a wide extension of the droop control, power coupling that always exists in the low-voltage microgrid, which may deteriorate the dynamic response and the stability of the system. In this paper, the principle of VSG control is introduced first. As an important issue of VSG control, the mechanism of the power coupling in the low-voltage microgrid is analyzed and the small-signal equivalent model of the power transmission loop is established. Subsequently, a power decoupling method based on the diagonal compensating matrix for VSG is proposed, which can realize the power decoupling with no impact on the original control channel. Meanwhile, the feasibility analysis of the decoupling method and the improved approach for reactive power sharing are also discussed. Simulation results verify the effectiveness of the decoupling strategy for VSGs.

  18. Efficient real time OD matrix estimation based on principal component analysis

    NARCIS (Netherlands)

    Djukic, T.; Flötteröd, G.; Van Lint, H.; Hoogendoorn, S.P.

    2012-01-01

    In this paper we explore the idea of dimensionality reduction and approximation of OD demand based on principal component analysis (PCA). First, we show how we can apply PCA to linearly transform the high dimensional OD matrices into the lower dimensional space without significant loss of accuracy.

  19. School Television: For Arts Education, Grades K-12. A Competency-Based Matrix.

    Science.gov (United States)

    North Carolina State Dept. of Public Instruction, Raleigh. Media and Technology Services.

    This manual keys school television programs to the Arts Education portion of the North Carolina "Teacher Handbook: Competency-Based Curriculum," and provides teachers with a guide to educational television programming according to competencies specified by the State of North Carolina in the area of arts education. Materials are divided into five…

  20. [Matrix transdermal systems for caffeine delivery based on polymer and emulsion compounds].

    Science.gov (United States)

    Kuznetsova, E G; Kuryleva, O M; Salomatina, L A; Sevast'ianov, V I

    2008-01-01

    The goal of this work was to develop and test transdermal therapeutic systems for caffeine delivery. In vitro experiments showed that the rate of caffeine diffusion through untreated rabbit skin from a transdermal therapeutic systems based on polymer compound containing 50 mg medicine was 67.2 (9.1 microg/cm2h; for a system based on emulsion compound it was 173 (19 microg/cm2h. Methods for studying the caffeine release rate and quantitative measurement of caffeine content in the emulsion-based transdermal therapeutic system were developed. These methods are required to obtain data for standard drug documentation. The results of in vivo experiments in rabbits showed the absence of irritating effect of the emulsion-based transdermal therapeutic system. The obtained data on the specific efficiency of the transdermal therapeutic systems for caffeine delivery (50 mg) in healthy volunteers showed that this medicine could be used as a nonnarcotic psychoactivator for improving mental and physical activities and attention concentration.

  1. The Integration of EIS parameters and bulk matrix characterization in studying reinforced cement-based materials

    NARCIS (Netherlands)

    Koleva, D.A.; Van Breugel, K.

    2012-01-01

    Corrosion in reinforced concrete is a major and costly concern, arising from the higher complexity of involved phenomena on different levels of material science (e.g. electrochemistry, concrete material science) and material properties (macro/micro/ nano). Reinforced cement-based systems (e.g.

  2. The integration of eis parameters and bulk matrix characteristics in studying reinforced cement-based materials

    NARCIS (Netherlands)

    Koleva, D.A.; Van Breugel, K.

    2011-01-01

    Corrosion in reinforced concrete is a major and costly concern, arising from the higher complexity of involved phenomena on different levels of material science (e.g. electrochemistry, concrete material science) and material properties (macro/micro/ nano). Reinforced cement-based systems (e.g.

  3. GPCR-drug interactions prediction using random forest with drug-association-matrix-based post-processing procedure.

    Science.gov (United States)

    Hu, Jun; Li, Yang; Yang, Jing-Yu; Shen, Hong-Bin; Yu, Dong-Jun

    2016-02-01

    G-protein-coupled receptors (GPCRs) are important targets of modern medicinal drugs. The accurate identification of interactions between GPCRs and drugs is of significant importance for both protein function annotations and drug discovery. In this paper, a new sequence-based predictor called TargetGDrug is designed and implemented for predicting GPCR-drug interactions. In TargetGDrug, the evolutionary feature of GPCR sequence and the wavelet-based molecular fingerprint feature of drug are integrated to form the combined feature of a GPCR-drug pair; then, the combined feature is fed to a trained random forest (RF) classifier to perform initial prediction; finally, a novel drug-association-matrix-based post-processing procedure is applied to reduce potential false positive or false negative of the initial prediction. Experimental results on benchmark datasets demonstrate the efficacy of the proposed method, and an improvement of 15% in the Matthews correlation coefficient (MCC) was observed over independent validation tests when compared with the most recently released sequence-based GPCR-drug interactions predictor. The implemented webserver, together with the datasets used in this study, is freely available for academic use at http://csbio.njust.edu.cn/bioinf/TargetGDrug. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Automatic annotation of histopathological images using a latent topic model based on non-negative matrix factorization.

    Science.gov (United States)

    Cruz-Roa, Angel; Díaz, Gloria; Romero, Eduardo; González, Fabio A

    2011-01-01

    Histopathological images are an important resource for clinical diagnosis and biomedical research. From an image understanding point of view, the automatic annotation of these images is a challenging problem. This paper presents a new method for automatic histopathological image annotation based on three complementary strategies, first, a part-based image representation, called the bag of features, which takes advantage of the natural redundancy of histopathological images for capturing the fundamental patterns of biological structures, second, a latent topic model, based on non-negative matrix factorization, which captures the high-level visual patterns hidden in the image, and, third, a probabilistic annotation model that links visual appearance of morphological and architectural features associated to 10 histopathological image annotations. The method was evaluated using 1,604 annotated images of skin tissues, which included normal and pathological architectural and morphological features, obtaining a recall of 74% and a precision of 50%, which improved a baseline annotation method based on support vector machines in a 64% and 24%, respectively.

  5. Automatic annotation of histopathological images using a latent topic model based on non-negative matrix factorization

    Directory of Open Access Journals (Sweden)

    Angel Cruz-Roa

    2011-01-01

    Full Text Available Histopathological images are an important resource for clinical diagnosis and biomedical research. From an image understanding point of view, the automatic annotation of these images is a challenging problem. This paper presents a new method for automatic histopathological image annotation based on three complementary strategies, first, a part-based image representation, called the bag of features, which takes advantage of the natural redundancy of histopathological images for capturing the fundamental patterns of biological structures, second, a latent topic model, based on non-negative matrix factorization, which captures the high-level visual patterns hidden in the image, and, third, a probabilistic annotation model that links visual appearance of morphological and architectural features associated to 10 histopathological image annotations. The method was evaluated using 1,604 annotated images of skin tissues, which included normal and pathological architectural and morphological features, obtaining a recall of 74% and a precision of 50%, which improved a baseline annotation method based on support vector machines in a 64% and 24%, respectively.

  6. Mechanical behaviour and diffusion of gas during neutron irradiation of actinides in ceramic inert matrices

    NARCIS (Netherlands)

    Neeft, E.A.C.

    2004-01-01

    Fission of actinides from nuclear waste in inert matrices (materials without uranium) can reduce the period in time that nuclear waste is more radiotoxic than uranium ore that is the rock from which ordinary reactor fuel is made. A pioneering study is performed with the inert matrices: MgO, MgAl2O4,

  7. Inerting of a Vented Aircraft Fuel Tank Test Article with Nitrogen-Enriched Air

    National Research Council Canada - National Science Library

    Burns, Michael

    2001-01-01

    ...) required to inert a vented aircraft fuel tank. NEA, generated by a hollow fiber membrane gas separation system, was used to inert a laboratory fuel tank with a single vent on top designed to simulate a transport category airplane fuel tank...

  8. Fog inerting effects on hydrogen combustion in a PWR ice condenser contaminant

    International Nuclear Information System (INIS)

    Luangdilok, W.; Bennett, R.B.

    1995-01-01

    A mechanistic fog inerting model has been developed to account for the effects of fog on the upward lean flammability limits of a combustible mixture based on the thermal theory of flame propagation. Benchmarking of this model with test data shows reasonably good agreement between the theory and the experiment. Applications of the model and available fog data to determine the upward lean flammability limits of the H 2 -air-steam mixture in the ice condenser upper plenum region of a pressurized water reactor (PWR) ice condenser contaminant during postulated large loss of coolant accident (LOCA) conditions indicate that combustion may be suppressed beyond the downward flammability limit (8 percent H 2 by volume). 18 refs., 3 tabs

  9. Active flux tungsten inert gas welding of austenitic stainless steel AISI 304

    Directory of Open Access Journals (Sweden)

    D. Klobčar

    2016-10-01

    Full Text Available The paper presents the effects of flux assisted tungsten inert gas (A-TIG welding of 4 (10 mm thick austenitic stainless steel EN X5CrNi1810 (AISI 304 in the butt joint. The sample dimensions were 300 ´ 50 mm, and commercially available active flux QuickTIG was used for testing. In the planned study the influence of welding position and weld groove shape was analysed based on the penetration depth. A comparison of microstructure formation, grain size and ferrit number between TIG welding and A-TIG welding was done. The A-TIG welds were subjected to bending test. A comparative study of TIG and A-TIG welding shows that A-TIG welding increases the weld penetration depth.

  10. One-loop contributions to neutral minima in the inert doublet model

    International Nuclear Information System (INIS)

    Ferreira, P.M.; Świeżewska, Bogumiła

    2016-01-01

    The vacuum structure of the inert doublet model is analysed at the one-loop level using the effective potential formalism, to verify the validity of tree-level predictions for the properties of the global minimum. An inert minimum (with massive fermions) and an inert-like minimum (with massless fermions) can coexist at tree level. But the one-loop analysis reveals that the allowed parameter space for the coexistence of more than one minimum is larger than the tree-level expected one. It is also shown that for some choices of parameters, the global minimum found at the one-loop level may be inert (or inert-like), contrary to what the tree-level analysis indicates.

  11. Effect of phosphate-based glass fibre surface properties on thermally produced poly(lactic acid) matrix composites.

    Science.gov (United States)

    Mohammadi, Maziar Shah; Ahmed, Ifty; Muja, Naser; Rudd, Christopher D; Bureau, Martin N; Nazhat, Showan N

    2011-12-01

    Incorporation of soluble bioactive glass fibres into biodegradable polymers is an interesting approach for bone repair and regeneration. However, the glass composition and its surface properties significantly affect the nature of the fibre-matrix interface and composite properties. Herein, the effect of Si and Fe on the surface properties of calcium containing phosphate based glasses (PGs) in the system (50P(2)O(5)-40CaO-(10-x)SiO(2)-xFe(2)O(3), where x = 0, 5 and 10 mol.%) were investigated. Contact angle measurements revealed a higher surface energy, and surface polarity as well as increased hydrophilicity for Si doped PG which may account for the presence of surface hydroxyl groups. Two PG formulations, 50P(2)O(5)-40CaO-10Fe(2)O(3) (Fe10) and 50P(2)O(5)-40CaO-5Fe(2)O(3)-5SiO(2) (Fe5Si5), were melt drawn into fibres and randomly incorporated into poly(lactic acid) (PLA) produced by melt processing. The ageing in deionised water (DW), mechanical property changes in phosphate buffered saline (PBS) and cytocompatibility properties of these composites were investigated. In contrast to Fe10 and as a consequence of the higher surface energy and polarity of Fe5Si5, its incorporation into PLA led to increased inorganic/organic interaction indicated by a reduction in the carbonyl group of the matrix. PLA chain scission was confirmed by a greater reduction in its molecular weight in PLA-Fe5Si5 composites. In DW, the dissolution rate of PLA-Fe5Si5 was significantly higher than that of PLA-Fe10. Dissolution of the glass fibres resulted in the formation of channels within the matrix. Initial flexural strength was significantly increased through PGF incorporation. After PBS ageing, the reduction in mechanical properties was greater for PLA-Fe5Si5 compared to PLA-Fe10. MC3T3-E1 preosteoblasts seeded onto PG discs, PLA and PLA-PGF composites were evaluated for up to 7 days indicating that the materials were generally cytocompatible. In addition, cell alignment along the PGF

  12. Investigation of He-induced swelling behaviour of inert matrices by 10B: the Bodex irradiation experiment

    International Nuclear Information System (INIS)

    Den Exter, M.; Klaassen, F.; Haas, G.J. de

    2007-01-01

    The BODEX experiment, part of the FP6 integrated project EUROTRANS, assesses the behaviour of inert matrices, envisaged for americium transmutation; magnesium oxide, yttrium-stabilised zirconium dioxide and 95 Mo-depleted molybdenum. More specific: the swelling behaviour due to He formation will be studied and compared for each matrix material. The work comprises the fabrication of the targets, doped with 10 B for fast He production and doped with 11 B as reference material, and subsequent irradiation and post-irradiation Examination (PIE) in the High Flux Reactor in Petten, The Netherlands. Though the work is still in progress, some preliminary results of the target production are presented together with the irradiation proposal. (authors)

  13. Stochastic-Strength-Based Damage Simulation Tool for Ceramic Matrix Composite

    Science.gov (United States)

    Nemeth, Noel; Bednarcyk, Brett; Pineda, Evan; Arnold, Steven; Mital, Subodh; Murthy, Pappu

    2015-01-01

    Reported here is a coupling of two NASA developed codes: CARES (Ceramics Analysis and Reliability Evaluation of Structures) with the MAC/GMC (Micromechanics Analysis Code/ Generalized Method of Cells) composite material analysis code. The resulting code is called FEAMAC/CARES and is constructed as an Abaqus finite element analysis UMAT (user defined material). Here we describe the FEAMAC/CARES code and an example problem (taken from the open literature) of a laminated CMC in off-axis loading is shown. FEAMAC/CARES performs stochastic-strength-based damage simulation response of a CMC under multiaxial loading using elastic stiffness reduction of the failed elements.

  14. FEAMAC/CARES Stochastic-Strength-Based Damage Simulation Tool for Ceramic Matrix Composites

    Science.gov (United States)

    Nemeth, Noel; Bednarcyk, Brett; Pineda, Evan; Arnold, Steven; Mital, Subodh; Murthy, Pappu; Bhatt, Ramakrishna

    2016-01-01

    Reported here is a coupling of two NASA developed codes: CARES (Ceramics Analysis and Reliability Evaluation of Structures) with the MAC/GMC (Micromechanics Analysis Code/ Generalized Method of Cells) composite material analysis code. The resulting code is called FEAMAC/CARES and is constructed as an Abaqus finite element analysis UMAT (user defined material). Here we describe the FEAMAC/CARES code and an example problem (taken from the open literature) of a laminated CMC in off-axis loading is shown. FEAMAC/CARES performs stochastic-strength-based damage simulation response of a CMC under multiaxial loading using elastic stiffness reduction of the failed elements.

  15. Boolean Matching Filters Based on Row and Column Weights of Reed–Muller Polarity Coefficient Matrix

    Directory of Open Access Journals (Sweden)

    Chip-Hong Chang

    2002-01-01

    Full Text Available In this article, we have shown, by means of the EXOR Ternary Decision Diagram that the number of literals and product terms of the Fixed Polarity Reed–Muller (FPRM expansions can be used to fully classify all Boolean functions in NP equivalent class and NPN equivalent class, respectively. Efficient graph based algorithms to compute the complete weight vectors have been presented. The proof and computation method has led to the derivation of a set of characteristic signatures that has low probability of aliasing when used as the Boolean matching filters in library mapping.

  16. Dynamic Regulatory Network Reconstruction for Alzheimer’s Disease Based on Matrix Decomposition Techniques

    Directory of Open Access Journals (Sweden)

    Wei Kong

    2014-01-01

    Full Text Available Alzheimer’s disease (AD is the most common form of dementia and leads to irreversible neurodegenerative damage of the brain. Finding the dynamic responses of genes, signaling proteins, transcription factor (TF activities, and regulatory networks of the progressively deteriorative progress of AD would represent a significant advance in discovering the pathogenesis of AD. However, the high throughput technologies of measuring TF activities are not yet available on a genome-wide scale. In this study, based on DNA microarray gene expression data and a priori information of TFs, network component analysis (NCA algorithm is applied to determining the TF activities and regulatory influences on TGs of incipient, moderate, and severe AD. Based on that, the dynamical gene regulatory networks of the deteriorative courses of AD were reconstructed. To select significant genes which are differentially expressed in different courses of AD, independent component analysis (ICA, which is better than the traditional clustering methods and can successfully group one gene in different meaningful biological processes, was used. The molecular biological analysis showed that the changes of TF activities and interactions of signaling proteins in mitosis, cell cycle, immune response, and inflammation play an important role in the deterioration of AD.

  17. New Cu-Free Ti-Based Composites with Residual Amorphous Matrix

    Directory of Open Access Journals (Sweden)

    Mircea Nicoara

    2016-04-01

    Full Text Available Titanium-based bulk metallic glasses (BMGs are considered to have potential for biomedical applications because they combine favorable mechanical properties and good biocompatibility. Copper represents the most common alloying element, which provides high amorphization capacity, but reports emphasizing cytotoxic effects of this element have risen concerns about possible effects on human health. A new copper-free alloy with atomic composition Ti42Zr10Pd14Ag26Sn8, in which Cu is completely replaced by Ag, was formulated based on Morinaga’s d-electron alloy design theory. Following this theory, the actual amount of alloying elements, which defines the values of covalent bond strength Bo and d-orbital energy Md, situates the newly designed alloy inside the BMG domain. By mean of centrifugal casting, cylindrical rods with diameters between 2 and 5 mm were fabricated from this new alloy. Differential scanning calorimetry (DSC and X-rays diffraction (XRD, as well as microstructural analyses using optical and scanning electron microscopy (OM/SEM revealed an interesting structure characterized by liquid phase-separated formation of crystalline Ag, as well as metastable intermetallic phases embedded in residual amorphous phases.

  18. Radiation defects in solid matrix as a physical base of EPR-dosimetry. The results of international experiment 'Intercomparison'

    International Nuclear Information System (INIS)

    Pivovarov, S.P.; Rukhin, A.B.; Seredavina, T.A.

    2004-01-01

    Full text: The very high sensitivity of EPR method at radiation defects in solid matrixes registration caused for last decade an intensive development of a new field - EPR-dosimetry. The suitable work substances had been found in a result of prolonged wide investigations, that allowed successful development both an operative dosimetry, and, that is especially important, the retrospective one. Nowadays the retrospective dosimetry on tooth enamel is adopted by IAEA and WHO as the main method of the radiation accidents consequences analysis for suffered population. In the report the methodical peculiarities of EPR-dosimetry are reviewed, the possible sources of the dose characteristics nonlinearity occurrence are analyzed as well other sources of errors and the ways of their elimination are considered. The review of the results of the international experiments 'Intercomparison' on EPR-dosimetry on tooth enamel series, held for last years under IAEA aegis is given. Practically all leading worldwide labs, including NMR laboratory of the INP NNC RK, took part in these experiments. The main goal was estimation of accuracy, sensitivity and reproducibility of summary dose values, having been reconstructed on base of EPR-signal of radiation defects in tooth enamel. The last experiment 'Intercomparison 3' has shown a considerable progress achieved lately in this area. Now the Japanese scientists from Hiroshima are preparing a further continuation of these Intercomparisons. Researches of radiation-induced EPR signals, stabilized in solid matrix, have been found out also rather useful and productive for the purposes of geological and archaeological dating, in criminalistics, in radiation chemistry and so on. Probably, this method will be rather perspective and at identification of radiation-sterilized food-stuffs, which come up now on world markets more and more often, however, studies in this direction are still on an incipient stage only

  19. Kinetics of the development of a nonchromate conversion coating for magnesium alloys and magnesium-based metal matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Nunez, M.A.; Skeldon, P.; Thompson, G.E.; Karimzadeh, H.

    1999-12-01

    Kinetics of the development of a conversion coating from a stannate bath on commercial purity magnesium (Mg{sup comm}), magnesium-based alloys ZC71 and WE43, and a metal matrix composite (MMC), comprising a ZC71 alloy matrix and 12 vol% silicon carbide (SiC) particles were studied using linear polarization resistance, potential-time, potentiodynamic polarization, x-ray diffraction, Rutherford backscattering spectroscopy, and microscopic examination. The coating, typically {approximately}3 {micro}m to 5 {micro}m thick, was composed largely of crystalline magnesium tin oxide (MgSnO{sub 3} {center{underscore}dot} 3H{sub 2}O), and developed by a nucleation and growth process through an initial corrosion film on the substrate. Nucleation probably occurred on regions where a critical concentration of magnesium ions was reached for coating crystals to form. Specific sites of nucleation, such as particles of eutectic phase and of reinforcement, were revealed in some cases, but frequently the precise sites of nucleation were not disclosed. A longer treatment time (at least 35 min) was suggested by polarization resistance data for improved coverage of the substrate than the previously recommended time of 20 min. The coating continuity on the substrates, after a particular time of treatment, depends upon ally composition increasing in order: Mg{sup comm}, 12% (SiC)p/ZC71 alloy MMC, ZC71 alloy, and WE43 alloy. Polarization resistance (R{sub p}) changed systematically with coating development, showing a decrease in R{sub p} in the early stages of the coating process, related to the initial corrosion.

  20. Construction of Uranyl Selective Electrode Based on Complex of Uranyl Ion with New Ligand Carboxybenzotriazole in PVC Matrix Membrane

    Science.gov (United States)

    Abu-Dalo, M. A.; Al-Rawashdeh, N. A. F.; Al-Mheidat, I. R.; Nassory, N. S.

    2015-10-01

    In the present study uranyl selective electrodes in polyvinyl chloride (PVC) matrix membrane were prepared based on a complex of uranyl ion (UO2) with carboxybenzotriazole (CBT) as ligand. The effect of the nature of plasticizer in PVC matrix were evaluated using three different plasticizers, these are dibutyl phthalate (DBP), dioctyl phthalate (DOP) and bis(2-ethylhexyl) sebacate (BHS). The results of this study indicated that the best plasticizer could be used is the DBP, which may be attributed to its lowest viscosity value compared to DOP and BHS. The electrodes with DBP as plasticizer exhibits a Nernstian response with a slope of 28.0 mV/ decade, over a wide range of concentration from 3.0×10-5-6.0×10-2 M and a detection limit of 4.0×10-6 M. It can be used in the pH range of 4.0-10.0 with a response time of less than 10 s for DBP and 25 s for both DOP and BHS. The effects of ions interferences on the electrode response were evaluated. The di- and tri-valent cations were found to interfere less than univalent cations, which was attributed to the high diffusion and the exchange rate between the univalent ions and the uranyl ion solution. The electrodes were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron microscopy (SEM). The results of the standard addition method were satisfactory with errors less than 7%. The developed electrode was found to be fast, sensitive and reliable indicated its potential use in measuring the uranly ion concentration in the field.

  1. Electrically conductive composites based on an elastomeric matrix filled with expanded graphite as a potential oil sensing material

    Science.gov (United States)

    Krupa, Igor; Prostredný, Martin; Špitalský, Zdenko; Krajči, Juraj; AlMaadeed, Mariam Ali S.

    2014-12-01

    The preparation and properties of electrically conductive polymeric composites based on an elastomer matrix (styrene-isoprene styrene block copolymer) filled with expanded graphite are reported in this paper. The developed materials were tested as oil sensors in various modes. The operation of this sensor is based on changes in the electrical resistance R of the composites when exposed to oil. This phenomenon involves both simple geometrical changes and changes in inherent material characteristics such as the specific electrical conductivity (resistivity). An original method for the improvement of the sensors’ response rate based on the application of stretched sensing films was developed. Slightly stretched films (by 4% of the original length) showed a response that was 12.5 times faster with respect to oil absorption than an un-stretched film. The specific electrical conductivity of a material strongly depends on the extent to which it is stretched. For a composite filled with 10 wt.% of the filler, it was found that the electrical conductivity remained constant up to 11% of the sample extension before sharply decreasing. It was also found that an increase in the filler content reduced the response rate of the sensors.

  2. Application of feal intermetallic phase matrix based alloys in the turbine components of a turbocharger

    Directory of Open Access Journals (Sweden)

    J. Cebulski

    2015-01-01

    Full Text Available This paper presents a possible application of the state-of-the-art alloys based on the FeAl intermetallic phases as materials for the manufacture of heat-proof turbine components in an automobile turbocharger. The research was aimed at determining the resistance to corrosion of Fe40Al5CrTiB alloy in a gaseous environment containing 9 % O2 + 0,2 % HCl + 0,08 % SO2 + N2. First the kinetics of corrosion processes for the considered alloy were determined at the temperatures of 900 °C, 1 000 °C and 1 100 °C, which was followed by validation under operating conditions. To do so, the tests were carried out over a distance of 20 000 km. The last stage involved examination of the surfaces after the test drive. The obtained results are the basis for further research in this field.

  3. Promising psyllium-based composite containing TiO2 nanoparticles as aspirin-carrier matrix

    Directory of Open Access Journals (Sweden)

    Marcela-Corina Rosu

    2014-06-01

    Full Text Available Composite nanomaterials represent a new trend in the biomedical field. Coupling inorganic/organic constituents with non-toxicity/biocompatibility properties leads to develop the new systems having special characteristics that can be used in various bio-applications. This paper describes the preparation and characterization of psyllium-based composites containing TiO2 nanoparticles in order to develop new therapeutic strategies for aspirin drug delivery. The structural characteristics of obtained materials were investigated by FTIR spectroscopy. The UV–vis spectrophotometric analysis was performed to evaluate the aspirin release behavior under different pH conditions at 37 °C. Combining psyllium (as an excellent source of fiber with TiO2 inorganic unit (as vehicle of aspirin it was found that polymeric-TiO2 networks have promising potential for controlled aspirin release as therapeutic agent.

  4. A review of recent neurochemical data on inert gas narcosis.

    Science.gov (United States)

    Rostain, J C; Lavoute, C; Risso, J J; Vallée, N; Weiss, M

    2011-01-01

    Nitrogen narcosis occurs in humans at around 0.4 MPa (4 ATA). Hydrogen narcosis occurs between 2.6 and 3.0 MPa. In rats, nitrogen disturbances occur from 1 MPa and a loss of righting reflex around 4 MPa. Neurochemical studies in striatum of rats with nitrogen at 3 MPa (75% of anesthesia threshold) with differential pulse voltammetry have demonstrated a decrease in dopamine (DA) release by neurons originated from the substantia nigra pars compacta (SNc). Such a decrease is found also with compressed argon, which is more narcotic than nitrogen and with the anesthetic gas nitrous oxide. Inversely, compressed helium with its very low narcotic potency induces DA increase. Microdialysis studies in the striatum have indicated that nitrogen also induces a decrease of glutamate concentration. Nitrogen pressure did not modify NMDA glutamate receptor activities in SNc or striatum but enhanced GABAA receptors activities in SNc. Repetitive exposures to nitrogen narcosis suppressed the DA decrease and induced an increase. This fact and the lack of improvement of motor disturbances did not support the hypothesis of a physiological adaptation. The desensitization of the GABAA receptors on DA cells during recurrent exposures and the parallel long-lasting decrease of glutamate coupled to the increase in NMDA receptor sensitivity suggest a nitrogen neurotoxicity or addiction induced by recurrent exposures. The differential changes produced by inert gases indifferent neurotransmitter receptors would support the binding protein theory.

  5. Classical scale invariance in the inert doublet model

    Energy Technology Data Exchange (ETDEWEB)

    Plascencia, Alexis D. [Institute for Particle Physics Phenomenology, Department of Physics,Durham University, Durham DH1 3LE (United Kingdom)

    2015-09-04

    The inert doublet model (IDM) is a minimal extension of the Standard Model (SM) that can account for the dark matter in the universe. Naturalness arguments motivate us to study whether the model can be embedded into a theory with dynamically generated scales. In this work we study a classically scale invariant version of the IDM with a minimal hidden sector, which has a U(1){sub CW} gauge symmetry and a complex scalar Φ. The mass scale is generated in the hidden sector via the Coleman-Weinberg (CW) mechanism and communicated to the two Higgs doublets via portal couplings. Since the CW scalar remains light, acquires a vacuum expectation value and mixes with the SM Higgs boson, the phenomenology of this construction can be modified with respect to the traditional IDM. We analyze the impact of adding this CW scalar and the Z{sup ′} gauge boson on the calculation of the dark matter relic density and on the spin-independent nucleon cross section for direct detection experiments. Finally, by studying the RG equations we find regions in parameter space which remain valid all the way up to the Planck scale.

  6. Vapor-liquid phase behavior of a size-asymmetric model of ionic fluids confined in a disordered matrix: The collective-variables-based approach

    Science.gov (United States)

    Patsahan, O. V.; Patsahan, T. M.; Holovko, M. F.

    2018-02-01

    We develop a theory based on the method of collective variables to study the vapor-liquid equilibrium of asymmetric ionic fluids confined in a disordered porous matrix. The approach allows us to formulate the perturbation theory using an extension of the scaled particle theory for a description of a reference system presented as a two-component hard-sphere fluid confined in a hard-sphere matrix. Treating an ionic fluid as a size- and charge-asymmetric primitive model (PM) we derive an explicit expression for the relevant chemical potential of a confined ionic system which takes into account the third-order correlations between ions. Using this expression, the phase diagrams for a size-asymmetric PM are calculated for different matrix porosities as well as for different sizes of matrix and fluid particles. It is observed that general trends of the coexistence curves with the matrix porosity are similar to those of simple fluids under disordered confinement, i.e., the coexistence region gets narrower with a decrease of porosity and, simultaneously, the reduced critical temperature Tc* and the critical density ρi,c * become lower. At the same time, our results suggest that an increase in size asymmetry of oppositely charged ions considerably affects the vapor-liquid diagrams leading to a faster decrease of Tc* and ρi,c * and even to a disappearance of the phase transition, especially for the case of small matrix particles.

  7. Electrical Resistance Based Damage Modeling of Multifunctional Carbon Fiber Reinforced Polymer Matrix Composites

    Science.gov (United States)

    Hart, Robert James

    In the current thesis, the 4-probe electrical resistance of carbon fiber-reinforced polymer (CFRP) composites is utilized as a metric for sensing low-velocity impact damage. A robust method has been developed for recovering the directionally dependent electrical resistivities using an experimental line-type 4-probe resistance method. Next, the concept of effective conducting thickness was uniquely applied in the development of a brand new point-type 4-probe method for applications with electrically anisotropic materials. An extensive experimental study was completed to characterize the 4-probe electrical resistance of CFRP specimens using both the traditional line-type and new point-type methods. Leveraging the concept of effective conducting thickness, a novel method was developed for building 4-probe electrical finite element (FE) models in COMSOL. The electrical models were validated against experimental resistance measurements and the FE models demonstrated predictive capabilities when applied to CFRP specimens with varying thickness and layup. These new models demonstrated a significant improvement in accuracy compared to previous literature and could provide a framework for future advancements in FE modeling of electrically anisotropic materials. FE models were then developed in ABAQUS for evaluating the influence of prescribed localized damage on the 4-probe resistance. Experimental data was compiled on the impact response of various CFRP laminates, and was used in the development of quasi- static FE models for predicting presence of impact-induced delamination. The simulation-based delamination predictions were then integrated into the electrical FE models for the purpose of studying the influence of realistic damage patterns on electrical resistance. When the size of the delamination damage was moderate compared to the electrode spacing, the electrical resistance increased by less than 1% due to the delamination damage. However, for a specimen with large

  8. Matrix thermalization

    Energy Technology Data Exchange (ETDEWEB)

    Craps, Ben [Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB), and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Evnin, Oleg [Department of Physics, Faculty of Science, Chulalongkorn University, Thanon Phayathai, Pathumwan, Bangkok 10330 (Thailand); Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB), and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Nguyen, Kévin [Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB), and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium)

    2017-02-08

    Matrix quantum mechanics offers an attractive environment for discussing gravitational holography, in which both sides of the holographic duality are well-defined. Similarly to higher-dimensional implementations of holography, collapsing shell solutions in the gravitational bulk correspond in this setting to thermalization processes in the dual quantum mechanical theory. We construct an explicit, fully nonlinear supergravity solution describing a generic collapsing dilaton shell, specify the holographic renormalization prescriptions necessary for computing the relevant boundary observables, and apply them to evaluating thermalizing two-point correlation functions in the dual matrix theory.

  9. Microcapsules Filled with a Palm Oil-Based Alkyd as Healing Agent for Epoxy Matrix

    Directory of Open Access Journals (Sweden)

    Nurshafiza Shahabudin

    2016-04-01

    Full Text Available One of the approaches to prolong the service lifespan of polymeric material is the development of self-healing ability by means of embedded microcapsules containing a healing agent. In this work, poly(melamine-urea-formaldehyde (PMUF microcapsules containing a palm oil-based alkyd were produced by polymerization of melamine resin, urea and formaldehyde that encapsulated droplets of the suspended alkyd particles. A series of spherical and free-flowing microcapsules were obtained. The chemical properties of core and shell materials were characterized by Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR and proton nuclear magnetic resonance spectroscopy (1H-NMR. Differential scanning calorimetry (DSC analysis showed a glass transition around −15 °C due to the alkyd, and a melting temperature at around 200 °C due to the shell. Thermogravimetric analysis (TGA results showed that the core and shell thermally degraded within the temperature range of 200–600 °C. Field emission scanning electron microscope (FESEM examination of the ruptured microcapsule showed smooth inner and rough outer surfaces of the shell. Flexural strength and microhardness (Vickers of the cured epoxy compound were not affected with the incorporation of 1%–3% of the microcapsules. The viability of the healing reactions was demonstrated by blending small amounts of alkyd with epoxy and hardener at different ratios. The blends could readily cure to non-sticky hard solids at room temperature and the reactions could be verified by ATR-FTIR.

  10. Preparation and characterization of a novel magnetorheological elastomer based on polyurethane/epoxy resin IPNs matrix

    Science.gov (United States)

    Yu, M.; Qi, S.; Fu, J.; Yang, P. A.; Zhu, M.

    2015-04-01

    This paper proposes the preparation of a novel magnetorheological elastomer (MRE) with improved damping and mechanical properties. This MRE is based on polyurethane (PU)/epoxy resin (EP) graft interpenetrating polymer networks (IPNs). The tensile strengths, thermal stability, magnetorhelogical behavior, and damping properties of the MRE are studied systematically in terms of composition. The Fourier transform infrared (FTIR) spectra verifies the formation of IPN structures, and thermogravimetric analysis (TGA) revealed that the thermal decomposition temperature was raised by the addition of IPN structures. The test results from the materials test machine and the rheometer show that the presence of IPN can significantly improve the tensile strength and damping properties of the MRE. In addition, the mechanism for enhancing tensile strength and damping properties is proposed. The experiment results suggest that the damping performance of the MRE has a significant correlation with the magnetic strength, content of EP, and temperature. As the thermal endurance properties, tensile strength, and loss factor are improved by incorporating EP/PU IPN structure, it is expected that the PU/EP IPN MRE can be used as an intelligent structural damping material.

  11. Structural and magnetic properties of the nanocomposite materials based on a mesoporous silicon dioxide matrix

    Energy Technology Data Exchange (ETDEWEB)

    Grigor’eva, N. A., E-mail: natali@lns.pnpi.spb.ru [St. Petersburg State University (Russian Federation); Eckerlebe, H. [Helmholtz-Zentrum Geesthacht (Germany); Eliseev, A. A.; Lukashin, A. V.; Napol’skii, K. S. [Moscow State University (Russian Federation); Kraje, M. [Reactor Institute Delft (Netherlands); Grigor’ev, S. V. [St. Petersburg State University (Russian Federation)

    2017-03-15

    The structural and magnetic properties of the mesoporous systems based on silicon dioxide with a regular hexagonal arrangement of pores several microns in length and several nanometers in diameter, which are filled with iron compound nanofilaments in various chemical states, are studied in detail. The studies are performed using the following mutually complementary methods: transmission electron microscopy, SQUID magnetometry, electron spin resonance, Mössbauer spectroscopy, polarized neutron small-angle diffraction, and synchrotron radiation diffraction. It is shown that the iron nanoparticles in pores are mainly in the γ phase of Fe{sub 2}O{sub 3} with a small addition of the α phase and atomic iron clusters. The effective magnetic field acting on a nanofilament from other nanofilaments is 11 mT and has a dipole nature, the ferromagnetic–paramagnetic transition temperature is in the range 76–94 K depending on the annealing temperature of the samples, and the temperature that corresponds to the change in the magnetic state of the iron oxide nanofilaments is T ≈ 50–60 K at H = 0 and T ≈ 80 K at H = 300 mT. It is also shown that the magnetization reversal of an array of nanofilaments is caused by the magnetostatic interaction between nanofilaments at the fields that are lower than the saturation field.

  12. Chromatographic matrix based on hydrogel-coated reticulated polyurethane foams, prepared by gamma irradiation

    Science.gov (United States)

    Sánchez, Mirna L.; Giménez, Claudia Y.; Delgado, Juan F.; Martínez, Leandro J.; Grasselli, Mariano

    2017-12-01

    Novel chromatographic materials for protein purification with high adsorption capacity and fouling resistance are highly demanded to improve downstream processes. Here, we describe a novel adsorptive material based on reticulated polyurethane foam (rPUF) coated with a functional hydrogel layer. rPUF provides physical rigidity through its macroscopic structure, whereas the hydrogel layer provides capacity to adsorb proteins by specific interactions. The hydrogel coating process was performed by the dip-coating method, using a polyvinyl alcohol (PVA) solution. The PVA hydrogel was linked to the rPUF material by using a radiation-induced crosslinking process in aqueous ethanol solution. The ethanol in the solvent mixture allowed a balance between PVA swelling and PVA dissolution during the irradiation step. The resulting material showed higher thermal stability than the non-irradiated one. In addition, a simultaneous radiation-induced grafting polymerization (SRIGP) was done by simple addition of glycidyl methacrylate monomer into the irradiation solution. In a further step, sulfonic ligands were included specifically in the hydrogel layer, which contained around 200% of PVA respect to the original rPUF. Materials were characterized by FT-IR, thermogravimetric analysis, SEM microscopy and EDX analysis. The cation-exchange rPUF material was functionally characterized by the Langmuir isotherm and a dynamic adsorption experiment to analyze the chromatographic properties for protein purification processes.

  13. Joint Dictionary Learning-Based Non-Negative Matrix Factorization for Voice Conversion to Improve Speech Intelligibility After Oral Surgery.

    Science.gov (United States)

    Fu, Szu-Wei; Li, Pei-Chun; Lai, Ying-Hui; Yang, Cheng-Chien; Hsieh, Li-Chun; Tsao, Yu

    2017-11-01

    Objective: This paper focuses on machine learning based voice conversion (VC) techniques for improving the speech intelligibility of surgical patients who have had parts of their articulators removed. Because of the removal of parts of the articulator, a patient's speech may be distorted and difficult to understand. To overcome this problem, VC methods can be applied to convert the distorted speech such that it is clear and more intelligible. To design an effective VC method, two key points must be considered: 1) the amount of training data may be limited (because speaking for a long time is usually difficult for postoperative patients); 2) rapid conversion is desirable (for better communication). Methods: We propose a novel joint dictionary learning based non-negative matrix factorization (JD-NMF) algorithm. Compared to conventional VC techniques, JD-NMF can perform VC efficiently and effectively with only a small amount of training data. Results: The experimental results demonstrate that the proposed JD-NMF method not only achieves notably higher short-time objective intelligibility (STOI) scores (a standardized objective intelligibility evaluation metric) than those obtained using the original unconverted speech but is also significantly more efficient and effective than a conventional exemplar-based NMF VC method. Conclusion: The proposed JD-NMF method may outperform the state-of-the-art exemplar-based NMF VC method in terms of STOI scores under the desired scenario. Significance: We confirmed the advantages of the proposed joint training criterion for the NMF-based VC. Moreover, we verified that the proposed JD-NMF can effectively improve the speech intelligibility scores of oral surgery patients. Objective: This paper focuses on machine learning based voice conversion (VC) techniques for improving the speech intelligibility of surgical patients who have had parts of their articulators removed. Because of the removal of parts of the articulator, a patient

  14. Molecular surface area based predictive models for the adsorption and diffusion of disperse dyes in polylactic acid matrix.

    Science.gov (United States)

    Xu, Suxin; Chen, Jiangang; Wang, Bijia; Yang, Yiqi

    2015-11-15

    Two predictive models were presented for the adsorption affinities and diffusion coefficients of disperse dyes in polylactic acid matrix. Quantitative structure-sorption behavior relationship would not only provide insights into sorption process, but also enable rational engineering for desired properties. The thermodynamic and kinetic parameters for three disperse dyes were measured. The predictive model for adsorption affinity was based on two linear relationships derived by interpreting the experimental measurements with molecular structural parameters and compensation effect: ΔH° vs. dye size and ΔS° vs. ΔH°. Similarly, the predictive model for diffusion coefficient was based on two derived linear relationships: activation energy of diffusion vs. dye size and logarithm of pre-exponential factor vs. activation energy of diffusion. The only required parameters for both models are temperature and solvent accessible surface area of the dye molecule. These two predictive models were validated by testing the adsorption and diffusion properties of new disperse dyes. The models offer fairly good predictive ability. The linkage between structural parameter of disperse dyes and sorption behaviors might be generalized and extended to other similar polymer-penetrant systems. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Safety and serological response to a matrix gene-deleted rabies virus-based vaccine vector in dogs.

    Science.gov (United States)

    McGettigan, James P; David, Frederic; Figueiredo, Monica Dias; Minke, Jules; Mebatsion, Teshome; Schnell, Matthias J

    2014-03-26

    Dogs account for the majority of human exposures and deaths due to rabies virus (RABV) worldwide. In this report, we show that a replication-deficient RABV-based vaccine in which the matrix gene is deleted (RABV-ΔM) is safe and induces rapid and potent VNA titers after a single inoculation in dogs. Average VNA titers peaked at 3.02 or 5.11 international units (IU/ml) by 14 days post-immunization with a single dose of 10(6) or 10(7) focus forming units (ffu), respectively, of RABV-ΔM. By day 70 post immunization, all dogs immunized with either dose of vaccine showed VNA titers >0.5IU/ml, the level indicative of a satisfactory immunization. Importantly, no systemic or local reactions were noted in any dog immunized with RABV-ΔM. The elimination of dog rabies through mass vaccination is hindered by limited resources, requirement for repeat vaccinations often for the life of a dog, and in some parts of the world, inferior vaccine quality. Our preliminary safety and immunogenicity data in dogs suggest that RABV-ΔM might complement currently used inactivated RABV-based vaccines in vaccination campaigns by helping to obtain 100% response in vaccinated dogs, thereby increasing overall vaccination coverage. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Surface modification of carbon fibers and its effect on the fiber–matrix interaction of UHMWPE based composites

    International Nuclear Information System (INIS)

    Chukov, D.I.; Stepashkin, A.A.; Gorshenkov, M.V.; Tcherdyntsev, V.V.; Kaloshkin, S.D.

    2014-01-01

    Highlights: • Both chemical and thermal treatments of UKN 5000 carbon fibers allow one to obtain well-developed surface. • The changes of structure and properties of VMN-4 fibers after both thermal and chemical oxidation are insignificant due to more perfect initial structure of these fibers. • The oxidative treatment of carbon fibers allows one to improve the interfacial interaction in the UHMWPE-based composites. • The oxidative treatment of the fibers allows one to a triple increase of Young’s modulus of the modified fibers reinforced UHMWPE composites. -- Abstract: The PAN-based carbon fibers (CF) were subjected to thermal and chemical oxidation under various conditions. The variation in the surface morphology of carbon fibers after surface treatment was analyzed by scanning electron microscopy (SEM). It was found that the tensile strength of carbon fibers changed after surface modification. The interaction between the fibers and the matrix OF ultra-high molecular weight polyethylene (UHMWPE) was characterized by the Young modulus of produced composites. It was shown that the Young modulus of composites reinforced with modified carbon fibers was significantly higher than that of composites reinforced with non-modified fibers

  17. Evaluation of Matrix Metalloproteinase Inhibition by Peptide Microarray-Based Fluorescence Assay on Polymer Brush Substrate and in Vivo Assessment.

    Science.gov (United States)

    Lei, Zhen; Chen, Hongda; Zhang, Hua; Wang, Yaoqi; Meng, Xianying; Wang, Zhenxin

    2017-12-20

    Matrix metalloproteinases (MMPs) are important biomarkers and potential therapeutic targets of tumor. In this report, a peptide microarray-based fluorescence assay is developed for MMPs inhibitors evaluation through immobilization of biotin-modified peptides on the poly(glycidyl methacrylate-co-2-hydroxyethyl methacrylate) (P(GMA-HEMA)) brush-modified glass slides. After biotin is recognized with cyanine 3 (Cy3)-modified avidin (Cy3-avidin), the microarrays can produce strong fluorescence signal. The biotin moieties detach from microarray, when the biotin-modified peptide substrates are specially cleaved by a MMP, resulting in decreased fluorescence intensity of the microarray. The decreasing level of fluorescence intensity is correlated with the MMP inhibition. Nine known MMP inhibitors against MMP-2 and MMP-9 are evaluated by the assay, and the quantitative determination of inhibitory potencies (half maximal inhibitory concentration) are obtained, which are comparable with the literatures. Two biocompatible fluorogenic peptides containing MMP-specific recognition sequences and FAM/Dabcyl fluorophore-quencher pair are designed as activatable reporter probes for sensing MMP-2 and MMP-9 activities in cell and in vivo. The peptide microarray-based results are well verified by the cell inhibition assay and in vitro fluorescence imaging, and further confirmed by the in vivo imaging of HT-1080 tumor-bearing mice.

  18. Influence of vegetable based cutting fluids on cutting force and vibration signature during milling of aluminium metal matrix composites

    Directory of Open Access Journals (Sweden)

    S. Shankar

    2017-03-01

    Full Text Available Due to the environmental and health issues, there is an enormous requirement for developing the novel cutting fluids (CFs. The vegetable based cutting fluid (VBCFs doesn’t affect the environment, diminish the harmful effects to the operator and also enhance the machining performances such as surface roughness, tool life, minimum vibration and cutting forces. In this work, the performances of four different VBCFs like palm, coconut, sunflower, soya bean oils, and a commercial type of CFs were considered to analyze the influence of cutting fluids while measuring the cutting force and vibration signatures during milling of 7075–T6 hybrid aluminium metal matrix composite with carbide insert tool. The experiments were conducted in CNC L-MILL 55 vertical machining center, with milling tool dynamometer to measure the cutting force and a tri-axial accelerometer to measure the vibration signals. The flow rate of the VBCFs were maintained at a constant rate and the results were compared with a commercial cutting fluid. The obtained result shows that palm oil suits better than the other vegetable based cutting fluids in terms of minimum cutting force requirement and minimum vibration. Also, the experimental result shows that the cutting fluid was one of the important parameter needs to be considered which influences the cutting force and vibration signals.

  19. Safety and Serological Response to a Matrix Gene-deleted Rabies Virus-based Vaccine Vector in Dogs

    Science.gov (United States)

    McGettigan, James P.; David, Frederic; Figueiredo, Monica Dias; Minke, Jules; Mebatsion, Teshome; Schnell, Matthias J.

    2014-01-01

    Dogs account for the majority of human exposures and deaths due to rabies virus (RABV) worldwide. In this report, we show that a replication-deficient RABV-based vaccine in which the matrix gene is deleted (RABV- M) is safe and induces rapid and potent VNA titers after a single inoculation in dogs. Average VNA titers peaked at 3.02 or 5.11 International Units (IU/ml) by 14 days post-immunization with a single dose of 106 or 107 focus forming units (ffu), respectively, of RABV- M. By day 70 post immunization, all dogs immunized with either dose of vaccine showed VNA titers >0.5 IU/ml, the level indicative of a satisfactory immunization. Importantly, no systemic or local reactions were noted in any dog immunized with RABV- M. The elimination of dog rabies through mass vaccination is hindered by limited resources, requirement for repeat vaccinations often for the life of a dog, and in some parts of the world, inferior vaccine quality. Our preliminary safety and immunogenicity data in dogs suggest that RABV- M might complement currently used inactivated RABV-based vaccines in vaccination campaigns by helping to obtain 100% response in vaccinated dogs, thereby increasing overall vaccination coverage. PMID:24508037

  20. A QSAR study on the inhibition mechanism of matrix metalloproteinase-12 by arylsulfone analogs based on molecular orbital calculations.

    Science.gov (United States)

    Hitaoka, Seiji; Chuman, Hiroshi; Yoshizawa, Kazunari

    2015-01-21

    A binding mechanism between human matrix metalloproteinase-12 (MMP-12) and eight arylsulfone analogs having two types of carboxylic and hydroxamic acids as the most representative zinc binding group is investigated using a quantitative structure-activity relationship (QSAR) analysis based on a linear expression by representative energy terms (LERE). The LERE-QSAR analysis quantitatively reveals that the variation in the observed (experimental) inhibitory potency among the arylsulfone analogs is decisively governed by those in the intrinsic binding and dispersion interaction energies. The results show that the LERE-QSAR analysis not only can excellently reproduce the observed overall free-energy change but also can determine the contributions of representative free-energy changes. An inter-fragment interaction energy difference (IFIED) analysis based on the fragment molecular orbital (FMO) method (FMO-IFIED) leads to the identification of key residues governing the variation in the inhibitory potency as well as to the understanding of the difference between the interactions of the carboxylic and hydroxamic acid zinc binding groups. The current results that have led to the optimization of the inhibitory potency of arylsulfone analogs toward MMP-12 to be used in the treatment of chronic obstructive pulmonary disease may be useful for the development of a new potent MMP-12 inhibitor.

  1. Efficient detection of total cholesterol using (ChEt–ChOx/ZnO/Pt/Si) bioelectrode based on ZnO matrix

    Energy Technology Data Exchange (ETDEWEB)

    Batra, Neha; Sharma, Anjali [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Tomar, Monika [Department of Physics, Miranda House, University of Delhi, Delhi 110007 (India); Gupta, Vinay, E-mail: drguptavinay@gmail.com [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

    2014-07-01

    Present study highlights the importance of ZnO matrix prepared by vapour phase transport technique on platinum coated Si platform (ZnO/Pt/Si) as a potential matrix for the realization of highly sensitive and selective bioelectrode for detection of total cholesterol. Bienzymes cholesterol esterase (ChEt) and cholesterol oxidase (ChOx) have been immobilized onto the surface of ZnO thin film matrix by physical adsorption technique. The prepared bioelectrode (ChEt–ChOx/ZnO/Pt/Si) is utilized for detection of total cholesterol using the cyclic voltammetry technique. The bioelectrode (ChEt–ChOx/ZnO/Pt/Si) is found to exhibit efficient sensing response characteristics with high sensitivity of 190 μA mM{sup −1} cm{sup −2}; good linearity in the range of 0.5–12 mM total cholesterol concentration, and a very low Michaelis–Menten constant of 0.68 mM which indicates high affinity of bienzymes immobilized on ZnO towards the analyte (total cholesterol). The enhanced response is attributed to the development of ZnO thin film based matrix having good electron transport property and nanoporous morphology for effective loading of enzymes with favourable orientation. - Highlights: • Fabrication of a ZnO nanostructured thin film based efficient matrix • Utilizing prepared matrix for detection of total cholesterol (free + esterified) • Cholesterol oxidase and cholesterol esterase are the corresponding selective enzymes. • Vapour phase transport technique, for the fabrication of nanostructured ZnO matrix • The bioelectrode exhibits enhanced response characteristics towards total cholesterol detection.

  2. Development of a composite large-size SiPM (assembled matrix) based modular detector cluster for MAGIC

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, A., E-mail: ahahn@mpp.mpg.de [Max Planck Institute for Physics (Werner-Heisenberg-Institut), Föhringer Ring 6, 80805 München (Germany); Mazin, D., E-mail: mazin@mpp.mpg.de [Max Planck Institute for Physics (Werner-Heisenberg-Institut), Föhringer Ring 6, 80805 München (Germany); Institute for Cosmic Ray Research, The University of Tokyo, 5-1-5 Kashiwa-no-Ha, Kashiwa City, Chiba 277–8582 (Japan); Bangale, P., E-mail: priya@mpp.mpg.de [Max Planck Institute for Physics (Werner-Heisenberg-Institut), Föhringer Ring 6, 80805 München (Germany); Dettlaff, A., E-mail: todettl@mpp.mpg.de [Max Planck Institute for Physics (Werner-Heisenberg-Institut), Föhringer Ring 6, 80805 München (Germany); Fink, D., E-mail: fink@mpp.mpg.de [Max Planck Institute for Physics (Werner-Heisenberg-Institut), Föhringer Ring 6, 80805 München (Germany); Grundner, F., E-mail: grundner@mpp.mpg.de [Max Planck Institute for Physics (Werner-Heisenberg-Institut), Föhringer Ring 6, 80805 München (Germany); Haberer, W., E-mail: haberer@mpp.mpg.de [Max Planck Institute for Physics (Werner-Heisenberg-Institut), Föhringer Ring 6, 80805 München (Germany); Maier, R., E-mail: rma@mpp.mpg.de [Max Planck Institute for Physics (Werner-Heisenberg-Institut), Föhringer Ring 6, 80805 München (Germany); and others

    2017-02-11

    The MAGIC collaboration operates two 17 m diameter Imaging Atmospheric Cherenkov Telescopes (IACTs) on the Canary Island of La Palma. Each of the two telescopes is currently equipped with a photomultiplier tube (PMT) based imaging camera. Due to the advances in the development of Silicon Photomultipliers (SiPMs), they are becoming a widely used alternative to PMTs in many research fields including gamma-ray astronomy. Within the Otto-Hahn group at the Max Planck Institute for Physics, Munich, we are developing a SiPM based detector module for a possible upgrade of the MAGIC cameras and also for future experiments as, e.g., the Large Size Telescopes (LST) of the Cherenkov Telescope Array (CTA). Because of the small size of individual SiPM sensors (6 mm×6 mm) with respect to the 1-inch diameter PMTs currently used in MAGIC, we use a custom-made matrix of SiPMs to cover the same detection area. We developed an electronic circuit to actively sum up and amplify the SiPM signals. Existing non-imaging hexagonal light concentrators (Winston cones) used in MAGIC have been modified for the angular acceptance of the SiPMs by using C++ based ray tracing simulations. The first prototype based detector module includes seven channels and was installed into the MAGIC camera in May 2015. We present the results of the first prototype and its performance as well as the status of the project and discuss its challenges. - Highlights: • The design of the first SiPM large-size IACT pixel is described. • The simulation of the light concentrators is presented. • The temperature stability of the detector module is demonstrated. • The calibration procedure of SiPM device in the field is described.

  3. The propulsive capability of explosives heavily loaded with inert materials

    Science.gov (United States)

    Loiseau, J.; Georges, W.; Frost, D. L.; Higgins, A. J.

    2018-01-01

    The effect of inert dilution on the accelerating ability of high explosives for both grazing and normal detonations was studied. The explosives considered were: (1) neat, amine-sensitized nitromethane (NM), (2) packed beds of glass, steel, or tungsten particles saturated with amine-sensitized NM, (3) NM gelled with PMMA containing dispersed glass microballoons, (4) NM gelled with PMMA containing glass microballoons and steel particles, and (5) C-4 containing varying mass fractions of glass or steel particles. Flyer velocity was measured via photonic Doppler velocimetry, and the results were analysed using a Gurney model augmented to include the influence of the diluent. Reduction in accelerating ability with increasing dilution for the amine-sensitized NM, gelled NM, and C-4 was measured experimentally. Variation of flyer terminal velocity with the ratio of flyer mass to charge mass (M/C) was measured for both grazing and normally incident detonations in gelled NM containing 10% microballoons by mass and for steel beads saturated with amine-sensitized NM. Finally, flyer velocity was measured in grazing versus normal loading for a number of explosive admixtures. The augmented Gurney model predicted the effect of dilution on accelerating ability and the scaling of flyer velocity with M/C for mixtures containing low-density diluents. The augmented Gurney model failed to predict the scaling of flyer velocity with M/C for mixtures heavily loaded with dense diluents. In all cases, normally incident detonations propelled flyers to higher velocity than the equivalent grazing detonations because of material velocity imparted by the incident shock wave and momentum/energy transfer from the slapper used to uniformly initiate the charge.

  4. Inertization of galvanic sludges by its incorporation in ceramic products

    Directory of Open Access Journals (Sweden)

    Ferreira, J. M. F.

    1999-04-01

    Full Text Available Sludges produced by the physico-chemical treatments of waste waters generated by electroplating plants were physically and chemically characterised and incorporated in ceramic pastes. The influence of the amount of sludges added to a typical brick composition on the various processing steps and on the green and fired properties was studied. The environmental risks of the incorporation of these sludges rich in heavy metals such as Cr, Pb, Zn, Cu, Ni, etc. were evaluated by performing leaching tests on the fired products. The results showed that sludge contents up to 15 % could be incorporated without affecting significantly the physical characteristics of the ceramic products. Furthermore, a successful inertization of the pollutants was achieved.

    Se han caracterizado desde el punto de vista químico y físico lodos procedentes de las aguas residuales de procesos de galvanizado. Posteriormente se han incorporado a pastas cerámicas, convencionales de la industria ladrillera, estudiándose la influencia de las cantidades añadidas sobre las propiedades de los materiales tanto en verde como en el producto final y durante las distintas etapas de fabricación. Se evaluaron los riesgos medioambientales derivados de la incorporación de los metales pesados, tales como Cr, Pb, Zn, Cu, Ni etc, presentes en los lodos, mediante la realización de ensayos de lixiviado. Los resultados indican que puede incorporarse hasta un 15% en peso de dichos lodos, sin que se produzcan cambios significativos en las propiedades físicas de los materiales cerámicos obtenidos. Se ha obtenido, asimismo, un procedimiento viable de inertización de los agentes contaminantes.

  5. The Reciprocal Pascal Matrix

    OpenAIRE

    Richardson, Thomas M.

    2014-01-01

    The reciprocal Pascal matrix is the Hadamard inverse of the symmetric Pascal matrix. We show that the ordinary matrix inverse of the reciprocal Pascal matrix has integer elements. The proof uses two factorizations of the matrix of super Catalan numbers.

  6. [Cost of intensive care in a German hospital: cost-unit accounting based on the InEK matrix].

    Science.gov (United States)

    Martin, J; Neurohr, C; Bauer, M; Weiss, M; Schleppers, A

    2008-05-01

    The aim of this study was to determine the actual cost per intensive care unit (ICU) day in Germany based on routine data from an electronic patient data management system as well as analysis of cost-driving factors. A differentiation between days with and without mechanical ventilation was performed. On the ICU of a German focused-care hospital (896 beds, 12 anesthesiology ICU beds), cost per treatment day was calculated with or without mechanical ventilation from the perspective of the hospital. Costs were derived retrospectively with respect to the period between January and October 2006 by cost-unit accounting based on routine data collected from the ICU patients. Patients with a length of stay of at least 2 days on the ICU were included. Demographic, clinical and economical data were analyzed for patient characterization. Data of 407 patients (217 male and 190 female) were included in the analysis, of which 159 patients (100 male, 59 female) were completely or partially mechanically ventilated. The mean simplified acute physiology (SAPS) II score at the onset of ICU stay was 28.2. Average cost per ICU day was 1,265 EUR and costs for ICU days with and without mechanical ventilation amounted to 1,426 EUR and 1,145 EUR, respectively. Personnel costs (50%) showed the largest cost share followed by drugs plus medicinal products (18%) and infrastructure (16%). For the first time, a cost analysis of intensive care in Germany was performed with routine data based on the matrix of the institute for reimbursement in hospitals (InEK). The results revealed a higher resource use on the ICU than previously expected. The large share of personnel costs on the ICU was evident but is comparable to other medical departments in the hospital. The need for mechanical ventilation increases the daily costs of resources by approximately 25%.

  7. Development of Certified Matrix-Based Reference Material as a Calibrator for Genetically Modified Rice G6H1 Analysis.

    Science.gov (United States)

    Yang, Yu; Li, Liang; Yang, Hui; Li, Xiaying; Zhang, Xiujie; Xu, Junfeng; Zhang, Dabing; Jin, Wujun; Yang, Litao

    2018-04-03

    The accurate monitoring and quantification of genetically modified organisms (GMOs) are key points for the implementation of labeling regulations, and a certified reference material (CRM) acts as the scaleplate for quantifying the GM contents of foods/feeds and evaluating a GMO analytical method or equipment. Herein we developed a series of CRMs for transgenic rice event G6H1, which possesses insect-resistant and herbicide-tolerant traits. Three G6H1 CRMs were produced by mixing seed powders obtained from homozygous G6H1 and its recipient cultivar Xiushui 110 at mass ratios of 49.825%, 9.967%, and 4.986%. The between-bottle homogeneity and within-bottle homogeneity were thoroughly evaluated with consistent results. The potential DNA degradation in transportation and shelf life were evaluated with an expiration period of at least 12 months. The property values of three CRMs (G6H1 a , G6H1 b , G6H1 c ) were given as (49.825 ± 0.448) g/kg, (9.967 ± 1.757) g/kg, and (4.986 ± 1.274 g/kg based on mass fraction ratio, respectively. Furthermore, the three CRMs were characterized with values of (5.01 ± 0.08)%, (1.06 ± 0.22)%, and (0.53 ± 0.11)% based on the copy number ratio using the droplet digital PCR method. All results confirmed that the produced G6H1 matrix-based CRMs are of high quality with precise characterization values and can be used as calibrators in GM rice G6H1 inspection and monitoring and in evaluating new analytical methods or devices targeting the G6H1 event.

  8. Nanofiber-based hydrogels with extracellular matrix-based synthetic peptides for the prevention of capsular opacification

    NARCIS (Netherlands)

    Nibourg, Lisanne M.; Gelens, Edith; de Jong, Menno R.; Kuijer, Roel; van Kooten, Theo G.; Koopmans, Steven A.

    Nanofiber-based hydrogels (nanogels) with different, covalently bound peptides were used as an extracellular environment for lens epithelial cells (LECs) in order to modulate the capsular opacification (CO) response after lens surgery in a porcine eye model. Lenses were divided into 15 groups (n = 4

  9. Polymer-based matrix composites in general industries. Ippan sangyo bun'ya ni okeru kobunshiki fukugo zairyo

    Energy Technology Data Exchange (ETDEWEB)

    Kenmochi, K. (National Institute of Materials and Chemical Research, Tsukuba (Japan))

    1994-02-15

    This paper summarizes the course of development of polymer-based matrix composites (PMC) begun in the 1950's, their future problems, and prospects. Because of PMC being a petroleum product, the changing period before and after the first and second oil crises (1974-1983) has seen even a negative growth from the declined product price out of increased material cost. However, the materials have been continuing expansion in such applications year after year for two decades since then as plant, marine vessel, and housing materials. The course of their development to date has included such proliferation impeding factors as unproved reliability, high production cost, and legal regulations because of being new materials. However, the ardent technical development efforts having produced a number of products including hybrid FRP, particularly the fundamental technology development studies sponsored by the Ministry of International Trade and Industry, have improved properties and reliability and contributed largely to expanding practical applications. Sought in different functions expected in PMC in the future would be application of bionic designs, transfer from functional quality to sensitive quality, and development of material recycling techniques. 8 refs., 11 figs., 1 tab.

  10. Calculating systems-scale energy efficiency and net energy returns: A bottom-up matrix-based approach

    International Nuclear Information System (INIS)

    Brandt, Adam R.; Dale, Michael; Barnhart, Charles J.

    2013-01-01

    In this paper we expand the work of Brandt and Dale (2011) on ERRs (energy return ratios) such as EROI (energy return on investment). This paper describes a “bottom-up” mathematical formulation which uses matrix-based computations adapted from the LCA (life cycle assessment) literature. The framework allows multiple energy pathways and flexible inclusion of non-energy sectors. This framework is then used to define a variety of ERRs that measure the amount of energy supplied by an energy extraction and processing pathway compared to the amount of energy consumed in producing the energy. ERRs that were previously defined in the literature are cast in our framework for calculation and comparison. For illustration, our framework is applied to include oil production and processing and generation of electricity from PV (photovoltaic) systems. Results show that ERR values will decline as system boundaries expand to include more processes. NERs (net energy return ratios) tend to be lower than GERs (gross energy return ratios). External energy return ratios (such as net external energy return, or NEER (net external energy ratio)) tend to be higher than their equivalent total energy return ratios. - Highlights: • An improved bottom-up mathematical method for computing net energy return metrics is developed. • Our methodology allows arbitrary numbers of interacting processes acting as an energy system. • Our methodology allows much more specific and rigorous definition of energy return ratios such as EROI or NER

  11. Tensor decomposition-based unsupervised feature extraction applied to matrix products for multi-view data processing

    Science.gov (United States)

    2017-01-01

    In the current era of big data, the amount of data available is continuously increasing. Both the number and types of samples, or features, are on the rise. The mixing of distinct features often makes interpretation more difficult. However, separate analysis of individual types requires subsequent integration. A tensor is a useful framework to deal with distinct types of features in an integrated manner without mixing them. On the other hand, tensor data is not easy to obtain since it requires the measurements of huge numbers of combinations of distinct features; if there are m kinds of features, each of which has N dimensions, the number of measurements needed are as many as Nm, which is often too large to measure. In this paper, I propose a new method where a tensor is generated from individual features without combinatorial measurements, and the generated tensor was decomposed back to matrices, by which unsupervised feature extraction was performed. In order to demonstrate the usefulness of the proposed strategy, it was applied to synthetic data, as well as three omics datasets. It outperformed other matrix-based methodologies. PMID:28841719

  12. Tensor decomposition-based unsupervised feature extraction applied to matrix products for multi-view data processing.

    Directory of Open Access Journals (Sweden)

    Y-H Taguchi

    Full Text Available In the current era of big data, the amount of data available is continuously increasing. Both the number and types of samples, or features, are on the rise. The mixing of distinct features often makes interpretation more difficult. However, separate analysis of individual types requires subsequent integration. A tensor is a useful framework to deal with distinct types of features in an integrated manner without mixing them. On the other hand, tensor data is not easy to obtain since it requires the measurements of huge numbers of combinations of distinct features; if there are m kinds of features, each of which has N dimensions, the number of measurements needed are as many as Nm, which is often too large to measure. In this paper, I propose a new method where a tensor is generated from individual features without combinatorial measurements, and the generated tensor was decomposed back to matrices, by which unsupervised feature extraction was performed. In order to demonstrate the usefulness of the proposed strategy, it was applied to synthetic data, as well as three omics datasets. It outperformed other matrix-based methodologies.

  13. Matrix-algebra-based calculations of the time evolution of the binary spin-bath model for magnetization transfer.

    Science.gov (United States)

    Müller, Dirk K; Pampel, André; Möller, Harald E

    2013-05-01

    Quantification of magnetization-transfer (MT) experiments are typically based on the assumption of the binary spin-bath model. This model allows for the extraction of up to six parameters (relative pool sizes, relaxation times, and exchange rate constants) for the characterization of macromolecules, which are coupled via exchange processes to the water in tissues. Here, an approach is presented for estimating MT parameters acquired with arbitrary saturation schemes and imaging pulse sequences. It uses matrix algebra to solve the Bloch-McConnell equations without unwarranted simplifications, such as assuming steady-state conditions for pulsed saturation schemes or neglecting imaging pulses. The algorithm achieves sufficient efficiency for voxel-by-voxel MT parameter estimations by using a polynomial interpolation technique. Simulations, as well as experiments in agar gels with continuous-wave and pulsed MT preparation, were performed for validation and for assessing approximations in previous modeling approaches. In vivo experiments in the normal human brain yielded results that were consistent with published data. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Effect of the Green/Blue Flicker Matrix for P300-Based Brain-Computer Interface: An EEG-fMRI Study.

    Science.gov (United States)

    Ikegami, Shiro; Takano, Kouji; Wada, Makoto; Saeki, Naokatsu; Kansaku, Kenji

    2012-01-01

    The visual P300-brain-computer interface, a popular system for EEG-based BCI, utilizes the P300 event-related potential to select an icon arranged in a flicker matrix. In the conventional P300-BCI speller paradigm, white/gray luminance intensification of each row/column in the matrix is used. In an earlier study, we applied green/blue luminance and chromatic change in the P300-BCI system and reported that this luminance and chromatic flicker matrix was associated with better performance and greater subject comfort compared with the conventional white/gray luminance flicker matrix. In this study, we used simultaneous EEG-functional magnetic resonance imaging (fMRI) recordings to identify brain areas that were more enhanced in the green/blue flicker matrix than in the white/gray flicker matrix, as these may highlight areas devoted to improved P300-BCI performance. The peak of the positive wave in the EEG data was detected under both conditions, and the peak amplitudes were larger at the parietal and occipital electrodes, particularly in the late components, under the green/blue condition than under the white/gray condition. fMRI data showed activation in the bilateral parietal and occipital cortices, and these areas, particularly those in the right hemisphere, were more activated under the green/blue condition than under the white/gray condition. The parietal and occipital regions more involved in the green/blue condition were part of the areas devoted to conventional P300s. These results suggest that the green/blue flicker matrix was useful for enhancing the so-called P300 responses.

  15. Silica-based ionic liquid coating for 96-blade system for extraction of aminoacids from complex matrixes

    Energy Technology Data Exchange (ETDEWEB)

    Mousavi, Fatemeh; Pawliszyn, Janusz, E-mail: janusz@uwaterloo.ca

    2013-11-25

    Graphical abstract: -- Highlights: •Silica-based 1-vinyl-3-octadecylimidazolium bromide ionic liquid was synthesized and characterized. •The synthesized polymer was immobilized on the stainless steel blade using polyacrylonitrile glue. •SiImC{sub 18}-PAN 96-blade SPME was applied as an extraction phase for extraction of highly polar compounds in grape matrix. •This system provides high extraction efficiency and reproducibility for up to 50 extractions from tartaric buffer and 20 extractions from grape pulp. -- Abstract: 1-Vinyl-3-octadecylimidazolium bromide ionic liquid [C{sub 18}VIm]Br was prepared and used for the modification of mercaptopropyl-functionalized silica (Si-MPS) through surface radical chain-transfer addition. The synthesized octadecylimidazolium-modified silica (SiImC{sub 18}) was characterized by thermogravimetric analysis (TGA), infrared spectroscopy (IR), {sup 13}C NMR and {sup 29}Si NMR spectroscopy and used as an extraction phase for the automated 96-blade solid phase microextraction (SPME) system with thin-film geometry using polyacrylonitrile (PAN) glue. The new proposed extraction phase was applied for extraction of aminoacids from grape pulp, and LC–MS–MS method was developed for separation of model compounds. Extraction efficiency, reusability, linearity, limit of detection, limit of quantitation and matrix effect were evaluated. The whole process of sample preparation for the proposed method requires 270 min for 96 samples simultaneously (60 min preconditioning, 90 min extraction, 60 min desorption and 60 min for carryover step) using 96-blade SPME system. Inter-blade and intra-blade reproducibility were in the respective ranges of 5–13 and 3–10% relative standard deviation (RSD) for all model compounds. Limits of detection and quantitation of the proposed SPME-LC–MS/MS system for analysis of analytes were found to range from 0.1 to 1.0 and 0.5 to 3.0 μg L{sup −1}, respectively. Standard addition calibration was

  16. Predicting the required number of training samples. [for remotely sensed image data based on covariance matrix estimate quality criterion of normal distribution

    Science.gov (United States)

    Kalayeh, H. M.; Landgrebe, D. A.

    1983-01-01

    A criterion which measures the quality of the estimate of the covariance matrix of a multivariate normal distribution is developed. Based on this criterion, the necessary number of training samples is predicted. Experimental results which are used as a guide for determining the number of training samples are included. Previously announced in STAR as N82-28109

  17. A novel matrix derivatized from hydrophilic gigaporous polystyrene-based microspheres for high-speed immobilized-metal affinity chromatography.

    Science.gov (United States)

    Qu, Jian-Bo; Huang, Yong-Dong; Jing, Guang-Lun; Liu, Jian-Guo; Zhou, Wei-Qing; Zhu, Hu; Lu, Jian-Ren

    2011-05-01

    Agarose coated gigaporous polystyrene microspheres were evaluated as a novel matrix for immobilized-metal affinity chromatography (IMAC). With four steps, nickel ions were successfully immobilized on the microspheres. The gigaporous structure and chromatographic properties of IMAC medium were characterized. A column packed with the matrix showed low column backpressure and high column efficiency at high flow velocity. Furthermore, this matrix was used for purifying superoxide dismutase (SOD), which was expressed in Escherichia coli (E. coli) in submerged fermentation, on an Äkta purifier 100 system under different flow velocities. The purity of the SOD from this one-step purification was 79% and the recovery yield was about 89.6% under the superficial flow velocity of 3251 cm/h. In conclusion, all the results suggested that the gigaporous matrix has considerable advantages for high-speed immobilized-metal affinity chromatography. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. System management model based on the design SWOT-matrix and quality management system for energy complex enterprise

    OpenAIRE

    Novikov, Vladimir

    2010-01-01

    The article deals with categorical apparatus of information management systems to build a model pairing SWOT-matrix and the quality management system, which is especially important for the energytion industry.

  19. Matrix inequalities

    CERN Document Server

    Zhan, Xingzhi

    2002-01-01

    The main purpose of this monograph is to report on recent developments in the field of matrix inequalities, with emphasis on useful techniques and ingenious ideas. Among other results this book contains the affirmative solutions of eight conjectures. Many theorems unify or sharpen previous inequalities. The author's aim is to streamline the ideas in the literature. The book can be read by research workers, graduate students and advanced undergraduates.

  20. HREM study of the matrix-pirecipitate interface structure and deformation mechanisms in a cobalt based superalloy

    OpenAIRE

    Penisson, J.-M.

    1991-01-01

    The structure of a Co-Ni-Cr-Nb superalloy has been studied using high resolution electron microscopy. An ordered hexagonal phase precipitates during annealing at temperatures from 700 to 850 °C. The compact planes and compact directions of the fcc matrix and precipitates are mutually parallel. The matrix precipitate interface is constituted by 3 sets of edge dislocations in a triangular distribution. The dislocation strain field has been calculated using the formalism of the Somigliana disloc...