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Sample records for system algainassb properties

  1. Comprehensive analysis of the internal losses in 2.0μm (AlGaIn)(AsSb) quantum-well diode lasers

    NASA Astrophysics Data System (ADS)

    Rattunde, M.; Schmitz, J.; Kiefer, R.; Wagner, J.

    2004-06-01

    We have fabricated and characterized high-power 2.0 μm-wavelength (AlGaIn)(AsSb) quantum-well diode lasers emitting a power of 1.7 W in continuous-wave operation and over 9 W in pulsed operation at 300 K heat sink temperature. For potential further improvement of laser performance, the different contribution to the internal losses αi has been analyzed in detail for the present laser structure. Consistent results have been obtained for a series of samples, for which different design parameters were varied systematically: As expected, the losses in the cladding layers are dominated by free carrier absorption in the p-doped cladding. The cross section for free-hole absorption in Al0.84Ga0.16As0.06Sb0.94 is determined to σP=4.6×10-17 cm2, which is comparable to values reported in the literature for (AlGaIn)(AsP)-based lasers emitting at 1.5 μm. The losses in the active region were found to increase linearly with increasing number of quantum wells at a rate of 1.5 cm-1 per quantum well, whereas the losses in the separate confinement layers are negligible.

  2. Property Information System

    Energy Science and Technology Software Center (ESTSC)

    1998-01-28

    Provides cradle to grave tracking of DOE property (capital, accountable, etc.). Major functional areas include Acquisitions, Management, Inventory, Accounting, Agreements, Excessing, Dispositions, and Reporting. The Accounting module is not used at this time and may not be operational. A major enhancement added here at Lockheed Martin Energy Systems is the Web-based portion of the system, which allows custodians of property to record location and custodial changes, and to provide inventory confirmations. PLEASE NOTE: Customer mustmore » contact Ben McMurry, (865) 576-5906, Lockheed Martin Energy Ssytems, for help with installation of package. The fee for this installation help will be coordinated by customer and Lockheed Martin and is in addition to the cost of the package from ESTSC. Customer should contact Cheri Cross, (865) 574-6046, for user help.« less

  3. Arsenic incorporation in molecular beam epitaxy (MBE) grown (AlGaIn)(AsSb) layers for 2.0-2.5 μm laser structures on GaSb substrates

    NASA Astrophysics Data System (ADS)

    Simanowski, S.; Walther, M.; Schmitz, J.; Kiefer, R.; Herres, N.; Fuchs, F.; Maier, M.; Mermelstein, C.; Wagner, J.; Weimann, G.

    1999-05-01

    The incorporation of As and In during MBE growth in (AlGaIn)/(AsSb) layers used for the fabrication of diode lasers in the 2.0-2.5 μm wavelength range has been investigated. The As content was found to depend linearly on the beam equivalent pressure for As mole fractions between y=0.05 and y=0.20. Broad area AlGaAsSb/GaInAsSb single-quantum well laser diodes with quasi-cw output at room temperature at an emission wavelength of 2.03 μm and a threshold current density of 515 A/cm 2 for 1370 μm long and 70 μm wide devices have been fabricated. In order to shift the emission wavelength of the laser structures to longer wavelengths, the growth of lattice matched AlGaAsSb/GaInAsSb laser core structures with different In and As mole fractions in the quantum wells has been investigated.

  4. Division 1137 property control system

    SciTech Connect

    Pastor, D.J.

    1982-01-01

    An automated data processing property control system was developed by Mobile and Remote Range Division 1137. This report describes the operation of the system and examines ways of using it in operational planning and control.

  5. Mass properties measurement system dynamics

    NASA Technical Reports Server (NTRS)

    Doty, Keith L.

    1993-01-01

    The MPMS mechanism possess two revolute degrees-of-freedom and allows the user to measure the mass, center of gravity, and the inertia tensor of an unknown mass. The dynamics of the Mass Properties Measurement System (MPMS) from the Lagrangian approach to illustrate the dependency of the motion on the unknown parameters.

  6. 48 CFR 45.105 - Contractors' property management system compliance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ACQUISITION REGULATION CONTRACT MANAGEMENT GOVERNMENT PROPERTY General 45.105 Contractors' property management... the contractor's property management policies, procedures, practices, and systems. This analysis shall... property administrator shall notify the contractor in writing when the contractor's property...

  7. 48 CFR 45.105 - Contractors' property management system compliance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ACQUISITION REGULATION CONTRACT MANAGEMENT GOVERNMENT PROPERTY General 45.105 Contractors' property management... the contractor's property management policies, procedures, practices, and systems. This analysis shall... property administrator shall notify the contractor in writing when the contractor's property...

  8. 48 CFR 45.105 - Contractors' property management system compliance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ACQUISITION REGULATION CONTRACT MANAGEMENT GOVERNMENT PROPERTY General 45.105 Contractors' property management... the contractor's property management policies, procedures, practices, and systems. This analysis shall... property administrator shall notify the contractor in writing when the contractor's property...

  9. 48 CFR 45.105 - Contractors' property management system compliance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... ACQUISITION REGULATION CONTRACT MANAGEMENT GOVERNMENT PROPERTY General 45.105 Contractors' property management... the contractor's property management policies, procedures, practices, and systems. This analysis shall... property administrator shall notify the contractor in writing when the contractor's property...

  10. 48 CFR 45.105 - Contractors' property management system compliance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ACQUISITION REGULATION CONTRACT MANAGEMENT GOVERNMENT PROPERTY General 45.105 Contractors' property management... the contractor's property management policies, procedures, practices, and systems. This analysis shall... property administrator shall notify the contractor in writing when the contractor's property...

  11. Thermodynamic properties of Heisenberg magnetic systems

    NASA Astrophysics Data System (ADS)

    Qin, Wei; Wang, Huai-Yu; Long, Gui-Lu

    2014-03-01

    In this paper, we present a comprehensive investigation of the effects of the transverse correlation function (TCF) on the thermodynamic properties of Heisenberg antiferromagnetic (AFM) and ferromagnetic (FM) systems with cubic lattices. The TCF of an FM system is positive and increases with temperature, while that of an AFM system is negative and decreases with temperature. The TCF lowers internal energy, entropy and specific heat. It always raises the free energy of an FM system but raises that of an AFM system only above a specific temperature when the spin quantum number is S >= 1. Comparisons between the effects of the TCFs on the FM and AFM systems are made where possible.

  12. Optical properties of Chern-Simons systems

    NASA Astrophysics Data System (ADS)

    Huerta, Luis

    2016-05-01

    Chern-Simons (CS) systems interacting with electromagnetic radiation are described by a term f FɅF added to the Maxwell action. In (3+1)D, this CS term is a boundary term affecting the system behaviour in its borders. We study the consequences of the above in the properties of electromagnetic radiation, in particular, by considering the interplay between magneto-electric properties and topology. Apart from a modified Kerr polarization rotation, compared to that found for the particular case of topological insulators, we also found two Brewster angles, for s and p polarization of reflected radiation, respectively. Energy distribution between reflected and transmitted radiation is also studied in terms of the magneto-electric properties and topological condition of the system.

  13. Quantum optical properties in plasmonic systems

    SciTech Connect

    Ooi, C. H. Raymond

    2015-04-24

    Plasmonic metallic particle (MP) can affect the optical properties of a quantum system (QS) in a remarkable way. We develop a general quantum nonlinear formalism with exact vectorial description for the scattered photons by the QS. The formalism enables us to study the variations of the dielectric function and photon spectrum of the QS with the particle distance between QS and MP, exciting laser direction, polarization and phase in the presence of surface plasmon resonance (SPR) in the MP. The quantum formalism also serves as a powerful tool for studying the effects of these parameters on the nonclassical properties of the scattered photons. The plasmonic effect of nanoparticles has promising possibilities as it provides a new way for manipulating quantum optical properties of light in nanophotonic systems.

  14. The thermoelectric properties of strongly correlated systems

    NASA Astrophysics Data System (ADS)

    Cai, Jianwei

    Strongly correlated systems are among the most interesting and complicated systems in physics. Large Seebeck coefficients are found in some of these systems, which highlight the possibility for thermoelectric applications. In this thesis, we study the thermoelectric properties of these strongly correlated systems with various methods. We derived analytic formulas for the resistivity and Seebeck coefficient of the periodic Anderson model based on the dynamic mean field theory. These formulas were possible as the self energy of the single impurity Anderson model could be given by an analytic ansatz derived from experiments and numerical calculations instead of complicated numerical calculations. The results show good agreement with the experimental data of rare-earth compound in a restricted temperature range. These formulas help to understand the properties of periodic Anderson model. Based on the study of rare-earth compounds, we proposed a design for the thermoelectric meta-material. This manmade material is made of quantum dots linked by conducting linkers. The quantum dots act as the rare-earth atoms with heavier mass. We set up a model similar to the periodic Anderson model for this new material. The new model was studied with the perturbation theory for energy bands. The dynamic mean field theory with numerical renormalization group as the impurity solver was used to study the transport properties. With these studies, we confirmed the improved thermoelectric properties of the designed material.

  15. 32 CFR 34.23 - Property management system.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 1 2014-07-01 2014-07-01 false Property management system. 34.23 Section 34.23... Requirements Property Standards § 34.23 Property management system. The recipient's property management system shall include the following, for property that is Federally owned, and for equipment that is acquired...

  16. 32 CFR 34.23 - Property management system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 1 2013-07-01 2013-07-01 false Property management system. 34.23 Section 34.23... Requirements Property Standards § 34.23 Property management system. The recipient's property management system shall include the following, for property that is Federally owned, and for equipment that is acquired...

  17. 32 CFR 34.23 - Property management system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Property management system. 34.23 Section 34.23... Requirements Property Standards § 34.23 Property management system. The recipient's property management system... maintained, to include the following information: (1) A description of the property. (2)...

  18. 10 CFR 600.323 - Property management system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Property management system. 600.323 Section 600.323 Energy....323 Property management system. The recipient's property management system must include the following: (a) Property records must be maintained, to include the following information for property that...

  19. Relaxation properties of weakly coupled classical systems

    SciTech Connect

    Romero-Rochin, V.; Oppenheim, I.

    1988-10-01

    The relaxation properties of a small classical system weakly coupled to a large classical system which acts as a heat bath are described using a generalized Fokker-Planck equation. The Fokker-Planck equation is derived in general using a modification of the elimination of fast variables techniques previously described. The specific example in which the small system is a harmonic oscillator linearly coupled to the heat bath is treated in detail and it is demonstrated that there is a dynamic frequency shift as well as a statistical shift of the oscillator frequency.

  20. 48 CFR 245.105 - Contractors' property management system compliance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT GOVERNMENT PROPERTY General 245.105 Contractors' property management system compliance. (a) Definitions— (1) Acceptable property management system and property management system are defined in the clause at 252.245-7003, Contractor...

  1. 48 CFR 245.105 - Contractors' property management system compliance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT GOVERNMENT PROPERTY General 245.105 Contractors' property management system compliance. (a) Definitions— (1) Acceptable property management system and property management system are defined in the clause at 252.245-7003, Contractor...

  2. 48 CFR 245.105 - Contractors' property management system compliance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT GOVERNMENT PROPERTY General 245.105 Contractors' property management system compliance. (a) Definitions— (1) Acceptable property management system and property management system are defined in the clause at 252.245-7003, Contractor...

  3. 48 CFR 245.105 - Contractors' property management system compliance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT GOVERNMENT PROPERTY General 245.105 Contractors' property management system compliance. (a) Definitions— (1) Acceptable property management system and property management system are defined in the clause at 252.245-7003, Contractor...

  4. Bioferroelectricity and optical properties of biological systems

    NASA Astrophysics Data System (ADS)

    Bystrov, Vladimir; Bystrova, Natalia

    2003-08-01

    A bioferroelectric approach to analysis of ferroelectric behavior of biological systems is presented. The optical properties of nerve fibers, biomembrane ion channels, and purple membrane films containing bacteriorhodopsin are analyzed. The features, influence of the proton subsystem and proton transfer on the hydrogen-bonded biomolecular structures are analyzed within the ferroelectric liquid-crystal model and possible biomedical applications discussed. The ferroelectric behavior of biological systems and the set of various bioferroelectric effects are considered within the limits of phenomenological theory of ferroelectrics. The nonlinear response to weak actions under conditions critical to human organism is one of specific features characterizing biological objects on molecular, cell and organism levels.

  5. 48 CFR 1245.511 - Audit of property control system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Audit of property control... 1245.511 Audit of property control system. (a) The property administrator (or other Government official authorized by the contracting officer) shall audit the contractor's property control system whenever...

  6. 48 CFR 1245.511 - Audit of property control system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Audit of property control... 1245.511 Audit of property control system. (a) The property administrator (or other Government official authorized by the contracting officer) shall audit the contractor's property control system whenever...

  7. 32 CFR 34.23 - Property management system.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 1 2011-07-01 2011-07-01 false Property management system. 34.23 Section 34.23... Requirements Property Standards § 34.23 Property management system. The recipient's property management system... differences between quantities determined by the physical inspection and those shown in the accounting...

  8. 32 CFR 34.23 - Property management system.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 1 2012-07-01 2012-07-01 false Property management system. 34.23 Section 34.23... Requirements Property Standards § 34.23 Property management system. The recipient's property management system... differences between quantities determined by the physical inspection and those shown in the accounting...

  9. Efficient hydraulic properties of root systems

    NASA Astrophysics Data System (ADS)

    Bechmann, Marcel; Schneider, Christoph; Carminati, Andrea; Hildebrandt, Anke

    2013-04-01

    Understanding the mechanisms of ecosystem root water uptake (RWU) is paramount for parameterizing hydrological models. With the increase in computational power it is possible to calculate RWU explicitly up to the single plant scale using physical models. However, application of these models for increasing our understanding of ecosystem root water uptake is hindered by the deficit in knowledge about the detailed hydraulic parameter distribution within root systems. However, those physical models may help us to identify efficient parameterizations and to describe the influence of these hydraulic parameters on RWU profiles. In this research, we investigated the combined influence of root hydraulic parameters and different root topologies on shaping efficient root water uptake. First, we use a conceptual model of simple branching structures to understand the influence of branching location and transitions in root hydraulic properties on the RWU patterns in typical sub root structures. Second, we apply a physical model called "aRoot" to test our conclusions on complex root system architectures of single plants. aRoot calculates the distribution of xylem potential within arbitrary root geometries to satisfy a given water demand depending on the available water in the soil. Redistribution of water within the bulk soil is calculated using the Richards equation. We analyzed results using a measure of uptake efficiency, which describes the effort necessary for transpiration. Simulations with the conceptual model showed that total transpiration in sub root structures is independent of root hydraulic properties over a wide range of hydraulic parameters. On the other hand efficiency of root water uptake depends crucially on distribution hydraulic parameters in line with root topology. At the same time, these parameters shape strongly the distribution of RWU along the roots, and its evolution in time, thus leading to variable individual root water uptake profiles. Calculating

  10. Erythropoiesis: from molecular pathways to system properties.

    PubMed

    Koulnis, Miroslav; Porpiglia, Ermelinda; Hidalgo, Daniel; Socolovsky, Merav

    2014-01-01

    Erythropoiesis is regulated through a long-range negative feedback loop, whereby tissue hypoxia stimulates erythropoietin (Epo) secretion, which promotes an increase in erythropoietic rate. However, this long-range feedback loop, by itself, cannot account for the observed system properties of erythropoiesis, namely, a wide dynamic range, stability in the face of random perturbations, and a rapid stress response. Here, we show that three Epo-regulated erythroblast survival pathways each give rise to distinct system properties. The induction of Bcl-xL by signal transducer and activator of transcription 5 (Stat5) is responsive to the rate of change in Epo levels, rather than to its absolute level, and is therefore maximally but transiently activated in acute stress. By contrast, Epo-mediated suppression of the pro-survival Fas and Bim pathways is proportional to the levels of stress/Epo and persists throughout chronic stress. Together, these elements operate in a manner reminiscent of a "proportional-integral-derivative (PID)" feedback controller frequently found in engineering applications. A short-range negative autoregulatory loop within the early erythroblast compartment, operated by Fas/FasL, filters out random noise and controls a reserve pool of early erythroblasts that is poised to accelerate the response to acute stress. Both these properties have previously been identified as inherent to negative regulatory motifs. Finally, we show that signal transduction by Stat5 combines binary and graded modalities, thereby increasing signaling fidelity over the wide dynamic range of Epo found in health and disease. PMID:25480636

  11. 10 CFR 600.323 - Property management system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Property management system. 600.323 Section 600.323 Energy....323 Property management system. The recipient's property management system must include the following... determined by the physical inspection and those shown in the accounting records must be investigated...

  12. 10 CFR 600.323 - Property management system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Property management system. 600.323 Section 600.323 Energy....323 Property management system. The recipient's property management system must include the following... determined by the physical inspection and those shown in the accounting records must be investigated...

  13. 10 CFR 600.323 - Property management system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Property management system. 600.323 Section 600.323 Energy....323 Property management system. The recipient's property management system must include the following... determined by the physical inspection and those shown in the accounting records must be investigated...

  14. 48 CFR 245.105 - Contractor's property management system compliance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT GOVERNMENT PROPERTY General 245.105 Contractor's property management system compliance. The assigned property administrator shall perform... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Contractor's...

  15. Systems and methods for predicting materials properties

    DOEpatents

    Ceder, Gerbrand; Fischer, Chris; Tibbetts, Kevin; Morgan, Dane; Curtarolo, Stefano

    2007-11-06

    Systems and methods for predicting features of materials of interest. Reference data are analyzed to deduce relationships between the input data sets and output data sets. Reference data includes measured values and/or computed values. The deduced relationships can be specified as equations, correspondences, and/or algorithmic processes that produce appropriate output data when suitable input data is used. In some instances, the output data set is a subset of the input data set, and computational results may be refined by optionally iterating the computational procedure. To deduce features of a new material of interest, a computed or measured input property of the material is provided to an equation, correspondence, or algorithmic procedure previously deduced, and an output is obtained. In some instances, the output is iteratively refined. In some instances, new features deduced for the material of interest are added to a database of input and output data for known materials.

  16. Surface properties of functional polymer systems

    NASA Astrophysics Data System (ADS)

    Wong, Derek

    Polymer surface modification typically involves blending with other polymers or chemical modification of the parent polymer. Such strategies inevitably result in polymer systems that are spatially and chemically heterogeneous, and which exhibit the phenomenon of surface segregation. This work investigates the effects of chain architecture on the surface segregation behavior of such functionally modified polymers using a series of end- and center-fluorinated poly(D,L-lactide). Surface segregation of the fluorinated functional groups was observed in both chain architectures via AMPS and water contact angle. Higher surface segregation was noted for functional groups located at the chain end as opposed to those in the middle of the chain. A self-consistent mean-field lattice theory was used to model the composition depth profiles of functional groups and excellent agreement was found between the model predictions and the experimental AMPS data in both chain architectures. Polymer properties are also in general dependent on both time and temperature, and exhibit a range of relaxation times in response to environmental stimuli. This behavior arises from the characteristic frequencies of molecular motions of the polymer chain and the interrelationship between time and temperature has been widely established for polymer bulk properties. There is evidence that surface properties also respond in a manner that is time and temperature dependent and that this dependence may not be the same as that observed for bulk properties. AMPS and water contact angle experiments were used to investigate the surface reorganization behavior of functional groups using a series of anionically synthesized end-fluorinated and end-carboxylated poly(styrene). It was found that both types of functional end-groups reorganized upon a change in the polarity of the surface environment in order to minimize the surface free energy. ADXPS and contact angle results suggest that the reorganization depth was

  17. 18 CFR 367.58 - Property record system required for service company property.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Property record system required for service company property. 367.58 Section 367.58 Conservation of Power and Water Resources... POWER ACT AND NATURAL GAS ACT Service Company Property Instructions § 367.58 Property record...

  18. 18 CFR 367.58 - Property record system required for service company property.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Property record system required for service company property. 367.58 Section 367.58 Conservation of Power and Water Resources... POWER ACT AND NATURAL GAS ACT Service Company Property Instructions § 367.58 Property record...

  19. 18 CFR 367.58 - Property record system required for service company property.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Property record system required for service company property. 367.58 Section 367.58 Conservation of Power and Water Resources... POWER ACT AND NATURAL GAS ACT Service Company Property Instructions § 367.58 Property record...

  20. 18 CFR 367.58 - Property record system required for service company property.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Property record system required for service company property. 367.58 Section 367.58 Conservation of Power and Water Resources... POWER ACT AND NATURAL GAS ACT Service Company Property Instructions § 367.58 Property record...

  1. 25 CFR 900.52 - What type of property is the property management system required to track?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false What type of property is the property management system... Property Management System Standards § 900.52 What type of property is the property management system required to track? The property management system of the Indian tribe or tribal organization shall...

  2. 25 CFR 900.52 - What type of property is the property management system required to track?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false What type of property is the property management system... Property Management System Standards § 900.52 What type of property is the property management system required to track? The property management system of the Indian tribe or tribal organization shall...

  3. 25 CFR 900.52 - What type of property is the property management system required to track?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 2 2014-04-01 2014-04-01 false What type of property is the property management system... Property Management System Standards § 900.52 What type of property is the property management system required to track? The property management system of the Indian tribe or tribal organization shall...

  4. 25 CFR 900.52 - What type of property is the property management system required to track?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 2 2012-04-01 2012-04-01 false What type of property is the property management system... Property Management System Standards § 900.52 What type of property is the property management system required to track? The property management system of the Indian tribe or tribal organization shall...

  5. 48 CFR 3045.511 - Audit of property control system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 7 2011-10-01 2011-10-01 false Audit of property control... Government Property in the Possession of Contractors 3045.511 Audit of property control system. (a) The... CFR 3045.505-14; (3) Failure of the contractor to reconcile its physical inventory with its...

  6. 48 CFR 3045.511 - Audit of property control system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Audit of property control... Government Property in the Possession of Contractors 3045.511 Audit of property control system. (a) The... CFR 3045.505-14; (3) Failure of the contractor to reconcile its physical inventory with its...

  7. Determines the Thermal and Optical Properties of Fenestration Systems

    Energy Science and Technology Software Center (ESTSC)

    1995-01-27

    WINDOW4.1 computes the thermal properties of windows and other fenestration elements used in typical residential and commercial buildings. Manufactures, specifiers, architects, consumers, and the energy code specialists all need to know these properties (U-values, Solar Heat Gain Coefficients, optical properties). The use of this program to calculate these properties is typically much more cost effective than laboratory test procedures. Properties of complete window systems are based on libraries (or user input) component data.

  8. Mechanical properties of thermal protection system materials.

    SciTech Connect

    Hardy, Robert Douglas; Bronowski, David R.; Lee, Moo Yul; Hofer, John H.

    2005-06-01

    An experimental study was conducted to measure the mechanical properties of the Thermal Protection System (TPS) materials used for the Space Shuttle. Three types of TPS materials (LI-900, LI-2200, and FRCI-12) were tested in 'in-plane' and 'out-of-plane' orientations. Four types of quasi-static mechanical tests (uniaxial tension, uniaxial compression, uniaxial strain, and shear) were performed under low (10{sup -4} to 10{sup -3}/s) and intermediate (1 to 10/s) strain rate conditions. In addition, split Hopkinson pressure bar tests were conducted to obtain the strength of the materials under a relatively higher strain rate ({approx}10{sup 2} to 10{sup 3}/s) condition. In general, TPS materials have higher strength and higher Young's modulus when tested in 'in-plane' than in 'through-the-thickness' orientation under compressive (unconfined and confined) and tensile stress conditions. In both stress conditions, the strength of the material increases as the strain rate increases. The rate of increase in LI-900 is relatively small compared to those for the other two TPS materials tested in this study. But, the Young's modulus appears to be insensitive to the different strain rates applied. The FRCI-12 material, designed to replace the heavier LI-2200, showed higher strengths under tensile and shear stress conditions. But, under a compressive stress condition, LI-2200 showed higher strength than FRCI-12. As far as the modulus is concerned, LI-2200 has higher Young's modulus both in compression and in tension. The shear modulus of FRCI-12 and LI-2200 fell in the same range.

  9. 10 CFR 600.323 - Property management system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Property management system. 600.323 Section 600.323 Energy DEPARTMENT OF ENERGY (CONTINUED) ASSISTANCE REGULATIONS FINANCIAL ASSISTANCE RULES Administrative Requirements for Grants and Cooperative Agreements With For-Profit Organizations Post-Award Requirements § 600.323 Property management system....

  10. Response properties of self-improving systems

    NASA Astrophysics Data System (ADS)

    Krakovsky, Andrey

    2016-04-01

    We observe that a sustained positivity (or negativity) of a system's second-order response will result in a directional change of the system's characteristics under the corresponding random exposure. We identify these changes with improvement (or decline) in the state of a system and introduce the concept of self-improving systems as systems which characteristics can sustainably improve under a random exposure. The resulting framework is of a general phenomenological nature and can be applied to complex systems across different areas of knowledge.

  11. Response properties of self-improving systems.

    PubMed

    Krakovsky, Andrey

    2016-04-01

    We observe that a sustained positivity (or negativity) of a system's second-order response will result in a directional change of the system's characteristics under the corresponding random exposure. We identify these changes with improvement (or decline) in the state of a system and introduce the concept of self-improving systems as systems which characteristics can sustainably improve under a random exposure. The resulting framework is of a general phenomenological nature and can be applied to complex systems across different areas of knowledge. PMID:27059562

  12. Fuel system design concepts for broad property fuels

    NASA Technical Reports Server (NTRS)

    Versaw, E. F.

    1984-01-01

    The results of a study assessing the impact of using jet fuel with relaxed specification properties on an aircraft fuel system are given. The study objectives were to identify credible values for specific fuel properties which might be relaxed, to evolve advanced fuel system designs for airframe and engines which would permit use of the specified relaxed properties fuels, and to evaluate performance of the candidate advanced fuel systems and the relaxed property fuels in a typical transport aircraft. The study used, as a baseline, the fuel system incorporated in the Lockheed Tristar. This aircraft is powered by three RB.211-524 Rolls-Royce engines and incorporates a Pratt and Whitney ST6C-421 auxiliary power unit for engine starting and inflight emergency electrical power. The fuel property limits examined are compared with commercial Jet A kerosene and the NASA RFP fuel properties. A screening of these properties established that a higher freezing point and a lower thermal stability would impact fuel system design more significantly than any of the other property changes. Three candidate fuel systems which combine the ability to operate with fuels having both a high freeze point and a low thermal stability are described. All candidates employ bleed air to melt fuel freeze-out prior to starting the APU or an inoperable engine. The effects of incorporating these systems on aircraft weight and engine specific fuel consumption are given.

  13. Analysis of fuel system technology for broad property fuels

    NASA Technical Reports Server (NTRS)

    Coffinberry, G. A.

    1984-01-01

    An analytical study was performed in order to assess relative performance and economic factors involved with alternative advanced fuel systems for future commercial aircraft operating with broad property fuels. Significant results, with emphasis on design practicality from the engine manufacturer' standpoint, are highlighted. Several advanced fuel systems were modeled to determine as accurately as possible the relative merits of each system from the standpoint of compatibility with broad property fuel. Freezing point, thermal stability, and lubricity were key property issues. A computer model was formulated to determine the investment incentive for each system. Results are given.

  14. Tillage system affects microbiological properties of soil

    NASA Astrophysics Data System (ADS)

    Delgado, A.; de Santiago, A.; Avilés, M.; Perea, F.

    2012-04-01

    Soil tillage significantly affects organic carbon accumulation, microbial biomass, and subsequently enzymatic activity in surface soil. Microbial activity in soil is a crucial parameter contributing to soil functioning, and thus a basic quality factor for soil. Since enzymes remain soil after excretion by living or disintegrating cells, shifts in their activities reflect long-term fluctuations in microbial biomass. In order to study the effects of no-till on biochemical and microbiological properties in comparison to conventional tillage in a representative soil from South Spain, an experiment was conducted since 1982 on the experimental farm of the Institute of Agriculture and Fisheries Research of Andalusia (IFAPA) in Carmona, SW Spain (37o24'07''N, 5o35'10''W). The soil at the experimental site was a very fine, montomorillonitic, thermic Chromic Haploxerert (Soil Survey Staff, 2010). A randomized complete block design involving three replications and the following two tillage treatments was performed: (i) Conventional tillage, which involved mouldboard plowing to a depth of 50 cm in the summer (once every three years), followed by field cultivation to a depth of 15 cm before sowing; crop residues being burnt, (ii) No tillage, which involved controlling weeds before sowing by spraying glyphosate and sowing directly into the crop residue from the previous year by using a planter with double-disk openers. For all tillage treatments, the crop rotation (annual crops) consisted of winter wheat, sunflower, and legumes (pea, chickpea, or faba bean, depending on the year), which were grown under rainfed conditions. Enzymatic activities (ß-glucosidase, dehydrogenase, aryl-sulphatase, acid phosphatase, and urease), soil microbial biomass by total viable cells number by acridine orange direct count, the density of cultivable groups of bacteria and fungi by dilution plating on semi-selective media, the physiological profiles of the microbial communities by BiologR, and the

  15. System for testing properties of a network

    DOEpatents

    Rawle, Michael; Bartholomew, David B.; Soares, Marshall A.

    2009-06-16

    A method for identifying properties of a downhole electromagnetic network in a downhole tool sting, including the step of providing an electromagnetic path intermediate a first location and a second location on the electromagnetic network. The method further includes the step of providing a receiver at the second location. The receiver includes a known reference. The analog signal includes a set amplitude, a set range of frequencies, and a set rate of change between the frequencies. The method further includes the steps of sending the analog signal, and passively modifying the signal. The analog signal is sent from the first location through the electromagnetic path, and the signal is modified by the properties of the electromagnetic path. The method further includes the step of receiving a modified signal at the second location and comparing the known reference to the modified signal.

  16. Fatigue properties of shuttle thermal protection system

    NASA Technical Reports Server (NTRS)

    Sawyer, J. W.; Cooper, P. A.

    1980-01-01

    Static and cyclic load tests were conducted to determine the static and fatigue strength of the RIS tile/SIP thermal protection system used on the orbiter of the space shuttle. The material systems investigated include the densified and undensified LI-900 tile system on the .40 cm thick SIP and the densified and undensified LI-2200 tile system on the .23 cm (.090 inch) thick SIP. The tests were conducted at room temperature with a fully reversed uniform cyclic loading at 1 Hertz. Cyclic loading causes a relatively large reduction in the stress level that each of the SIP/tile systems can withstand for a small number of cycles. For example, the average static strength of the .40 cm thick SIP/LI-900 tile system is reduced from 86 kPa to 62 kPa for a thousand cycles. Although the .23 cm thick SIP/LI-2200 tile system has a higher static strength, similar reductions in the fatigue strength are noted. Densifying the faying surface of the RSI tile changes the failure mode from the SIP/tile interface to the parent RSI or the SIP and thus greatly increases the static strength of the system. Fatigue failure for the densified tile system, however, occurs due to complete separation or excessive elongation of the SIP and the fatigue strength is only slightly greater than that for the undensified tile system.

  17. Systems of HESS-APPEL'ROT Type and Zhukovskii Property

    NASA Astrophysics Data System (ADS)

    Dragović, Vladimir; Gajić, Borislav; Jovanović, Božidar

    We start with a review of a class of systems with invariant relations, so called {\\it systems of Hess--Appel'rot type} that generalizes the classical Hess--Appel'rot rigid body case. The systems of Hess-Appel'rot type carry an interesting combination of both integrable and non-integrable properties. Further, following integrable line, we study partial reductions and systems having what we call the {\\it Zhukovskii property}: these are Hamiltonian systems with invariant relations, such that partially reduced systems are completely integrable. We prove that the Zhukovskii property is a quite general characteristic of systems of Hess-Appel'rote type. The partial reduction neglects the most interesting and challenging part of the dynamics of the systems of Hess-Appel'rot type - the non-integrable part, some analysis of which may be seen as a reconstruction problem. We show that an integrable system, the magnetic pendulum on the oriented Grassmannian $Gr^+(4,2)$ has natural interpretation within Zhukovskii property and it is equivalent to a partial reduction of certain system of Hess-Appel'rot type. We perform a classical and an algebro-geometric integration of the system, as an example of an isoholomorphic system. The paper presents a lot of examples of systems of Hess-Appel'rot type, giving an additional argument in favor of further study of this class of systems.

  18. 18 CFR 367.58 - Property record system required for service company property.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Property record system required for service company property. 367.58 Section 367.58 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE PUBLIC UTILITY HOLDING COMPANY ACT OF 2005, FEDERAL POWER ACT...

  19. Groups graded by root systems and property (T)

    PubMed Central

    Ershov, Mikhail; Jaikin-Zapirain, Andrei; Kassabov, Martin; Zhang, Zezhou

    2014-01-01

    We establish property (T) for a large class of groups graded by root systems, including elementary Chevalley groups and Steinberg groups of rank at least 2 over finitely generated commutative rings with 1. We also construct a group with property (T) which surjects onto all finite simple groups of Lie type and rank at least two. PMID:25425669

  20. General Properties of Overlap Operators in Disordered Quantum Spin Systems

    NASA Astrophysics Data System (ADS)

    Itoi, C.

    2016-04-01

    We study short-range quantum spin systems with Gaussian disorder. We obtain quantum mechanical extensions of the Ghirlanda-Guerra identities. We discuss properties of overlap spin operators with these identities.

  1. Advanced fuel system technology for utilizing broadened property aircraft fuels

    NASA Technical Reports Server (NTRS)

    Reck, G. M.

    1980-01-01

    Possible changes in fuel properties are identified based on current trends and projections. The effect of those changes with respect to the aircraft fuel system are examined and some technological approaches to utilizing those fuels are described.

  2. Thermodynamic properties of a polydisperse system.

    PubMed

    Tutschka, C; Kahl, G

    2001-09-01

    We use the virial theorem to derive a closed analytic form of the Helmholtz free energy for a polydisperse system of sticky hard spheres (SHS) within the mean spherical model (MSM). To this end we calculate the free energy of the MSM for an N-component mixture of SHS via the virial route and apply to it-after imposing a Lorentz-Berthelot type rule on the interactions-the stochastic (i.e., polydisperse) limit. The resulting excess free energy of this polydisperse system is of the truncatable moment free energy format. We also discuss the compressibility and the energy routes. PMID:11580316

  3. Coupled chemical oscillators and emergent system properties.

    PubMed

    Epstein, Irving R

    2014-09-25

    We review recent work on a variety of systems, from the nanometre to the centimetre scale, including microemulsions, microfluidic droplet arrays, gels and flow reactors, in which chemical oscillators interact to generate novel spatiotemporal patterns and/or mechanical motion. PMID:24835430

  4. Automated electronic system for measuring thermophysical properties

    NASA Technical Reports Server (NTRS)

    Creel, T. R., Jr.; Jones, R. A.; Corwin, R. R.; Kramer, J. S.

    1975-01-01

    Phase-charge coatings are used to measure surface temperature accurately under transient heating conditions. Coating melts when surface reaches calibrated phase-charge temperature. Temperature is monitored by infrared thermometer, and corresponding elapsed time is recorded by electronic data-handling system.

  5. Extension of Generalized Fluid System Simulation Program's Fluid Property Database

    NASA Technical Reports Server (NTRS)

    Patel, Kishan

    2011-01-01

    This internship focused on the development of additional capabilities for the General Fluid Systems Simulation Program (GFSSP). GFSSP is a thermo-fluid code used to evaluate system performance by a finite volume-based network analysis method. The program was developed primarily to analyze the complex internal flow of propulsion systems and is capable of solving many problems related to thermodynamics and fluid mechanics. GFSSP is integrated with thermodynamic programs that provide fluid properties for sub-cooled, superheated, and saturation states. For fluids that are not included in the thermodynamic property program, look-up property tables can be provided. The look-up property tables of the current release version can only handle sub-cooled and superheated states. The primary purpose of the internship was to extend the look-up tables to handle saturated states. This involves a) generation of a property table using REFPROP, a thermodynamic property program that is widely used, and b) modifications of the Fortran source code to read in an additional property table containing saturation data for both saturated liquid and saturated vapor states. Also, a method was implemented to calculate the thermodynamic properties of user-fluids within the saturation region, given values of pressure and enthalpy. These additions required new code to be written, and older code had to be adjusted to accommodate the new capabilities. Ultimately, the changes will lead to the incorporation of this new capability in future versions of GFSSP. This paper describes the development and validation of the new capability.

  6. Mechanical properties of hybrid polymer nanotube systems

    NASA Astrophysics Data System (ADS)

    Coleman, Jonathan N.; Cadek, Martin; Dalton, Alan B.; Munoz, Edgar; Razal, Joselito; Baughman, Ray H.; Blau, Werner J.

    2003-04-01

    In this work, mechanical properties of hybrid materials fabricated from nanotubes and commercially available polymers were investigated. It was found that, by adding various concentrations of arc discharge multiwall nanotubes, both Young"s modulus and hardness increased by factors of 1.8 and 1.6 at 1wt% in PVA and 2.8 and 2.0 at 8wt% in PVK, in reasonable agreement with the Halpin-Tsai theory. Furthermore, the presence of the nanotubes was found to nucleate crystallization of the PVA. This crystal growth is thought to enhance matrix-nanotube stress transfer. In addition, microscopy studies suggest extremely strong interfacial bonding in the PVA-based composite. This is manifested by the fracture of the polymer rather that the polymer-nanotube interface. The dependence of the polymer nanotube interfacial interaction on host polymer was studied by intercalating various polymers (PVA, PVP and PS) into single wall nanotube buckypaper. Even for short soak times, significant polymer intercalation into existing free volume was observed. Depending on the polymer and the level of intercalation tensile tests on intercalated sheets showed that the Young"s modulus, strength and toughness increased by factors of 3, 9 and 28, respectively. This indicates that the intercalated polymer enhances load transmission between nanotubes due the significant stress transfer. The level of stress transfer was observed to scale with polymer hydrophobicity as expected.

  7. Magnetic Properties of Diluted Fcc System Nickel

    NASA Astrophysics Data System (ADS)

    Feng, Zhen

    Starting from Ni and Mg nitrates, about 20 samples of Ni_{rm p}Mg _{rm 1-p}O (0.06 <=q p <=q 0.86) were prepared and X-ray diffraction studies showed the samples to have the NaCl structure with the lattice constant fitting the equation a(p) = 4.2115 - 0.0340p A. Temperature dependent dc magnetic susceptibility (chi ) studies of the samples were carried out between 1.8K and 600K using a SQUID magnetometer and the Neel temperature T_{rm N} were determined from the peak in partial(chiT)/ partialT. The variation of t = T _{rm N}(p)/T _{rm N}(1) versus p is compared with that in Co_{rm p}Mg _{rm 1-p}O. For both systems, the variations for p > 0.31 are found to fit the predicted values for a simple cubic Heisenberg antiferromagnet and a theoretical basis for this anomalous results is advanced. The experimental percolation threshold p_{rm c} = 0.15 +/- 0.01. For p_ {rm c} <=q p <=q 0.33, chi below T_{rm N} shows irreversible behavior for the zero-field-cooled and field -cooled cases, suggestive of spin-glass-like behavior, also observed in other diluted fcc antiferromagnets such as Co_{rm p}Mg _{rm 1-p}O and Eu _{rm p}Sr_ {rm 1-p}Te. It is suggested that the differences in the t vs p variations for p < 0.33 in Ni_{rm p} Mg_{rm 1-p}O, Co_{rm p}Mg _{rm 1-p}O and Eu _{rm p}Sr_ {rm 1-p}Te may be related to the differences in the ratio of the next-nearest-neighbor to nearest-neighbor exchange constants in these systems. A higher order correction to Curie-Weiss law was applied for sample with 0.19 <=q p <=q 0.59 which explains why 1/ chi curve versus T bends downward with decreasing temperatures. For the sample Ni_{0.33} Mg_{0.67}O, the magnetization M versus magnetic field H (0 to 0.2T) are measured with temperature ranging from 5.2K to 13.4K at intervals of 0.2K. The magnitude of the non-linear susceptibility, a_3, is determined from the M versus H data at different temperatures. The divergence of a _3 around 9.4 +/- 0.6K indicates spin-glass behavior in this system.

  8. New Strategies for Teaching Properties of Number Systems

    ERIC Educational Resources Information Center

    Creswell, John L.; Wiscamb, Margaret

    1970-01-01

    Presents techniques and materials for instruction at secondary school and upper elementary grades in mathematical concepts of number systems structure. Grouping is used as a simple algebraic system to illustrate structure. Closure, inverse, identity, commutative and associative properties are examines relative to manipulation of geometric figureS.…

  9. Chemosensory Properties of the Trigeminal System

    PubMed Central

    2010-01-01

    The capacity of cutaneous, including trigeminal endings, to detect chemicals is known as chemesthesis or cutaneous chemosensation. This sensory function involves the activation of nociceptor and thermoreceptor endings and has a protective or defensive function, as many of these substances are irritants or poisonous. However, humans have also developed a liking for the distinct sharpness or pungency of many foods, beverages, and spices following activation of the same sensory afferents. Our understanding of the cellular and molecular mechanisms of chemosensation in the trigeminal system has experienced enormous progress in the past decade, following the cloning and functional characterization of several ion channels activated by physical and chemical stimuli. This brief review attempts to summarize our current knowledge in this field, including a functional description of various sensory channels, especially TRP channels, involved in trigeminal chemosensitivy. Finally, some of these new findings are discussed in the context of the pathophysiology of trigeminal chemosensation, including pain, pruritus, migraine, cough, airway inflammation, and ophthalmic diseases. PMID:22778855

  10. Cryogenic compressive properties of basic epoxy resin systems

    SciTech Connect

    Markley, F.W.; Hoffman, J.A.; Muniz, D.P.

    1985-09-01

    The compressive properties of short cylindrical samples of many different epoxy resin systems have been measured at ambient temperature and at 77/sup 0/K. These are pure resin systems of known chemistry, without the inorganic fillers or fibrous reinforcements needed in final cryogenic systems. Of course, chemically incorporated modifiers such as flexibilizing resins have been included. This data should make possible inferences about cryogenic properties from molecular structures and provide specific data useful to formulators and end users. Measurements on some other plastics such as PTFE, Polyimides, and UHMWPE have been made for comparison purposes.

  11. New entanglement properties in systems of higher-spin particles

    NASA Astrophysics Data System (ADS)

    Lawrence, Jay; Gaeta, Mario; Klimov, Andrei

    2012-02-01

    We describe a new entanglement property of four-qutrit states that is inaccessable to any number of qubits. In such states, every particle is equally entangled with all others, as in GHZ states, but the entanglement is more robust than that of any four-qubit state. We describe the entanglement properties of related generalized graph states of three-state and five-state particles, and show how these suggest that new entanglement properties will emerge more generally for systems of p+1 particles, each having p states, where p is a prime number.

  12. Scaling properties of force networks for compressed particulate systems

    NASA Astrophysics Data System (ADS)

    Kovalcinova, L.; Goullet, A.; Kondic, L.

    2016-04-01

    We consider, computationally and experimentally, the scaling properties of force networks in the systems of circular particles exposed to compression in two spatial dimensions. The simulations consider polydisperse and monodisperse particles, both frictional and frictionless, and in experiments we use monodisperse and bidisperse frictional particles. While for some of the considered systems we observe consistent scaling exponents describing the behavior of the force networks, we find that this behavior is not universal. In particular, we find that frictionless systems, independently of whether they partially crystallize under compression or not, show scaling properties that are significantly different compared to the frictional disordered ones. The findings of nonuniversality are confirmed by explicitly computing fractal dimension for the considered systems. The results of the physical experiments are consistent with the results obtained in simulations of frictional disordered systems.

  13. Electronic properties of graphene-based bilayer systems

    NASA Astrophysics Data System (ADS)

    Rozhkov, A. V.; Sboychakov, A. O.; Rakhmanov, A. L.; Nori, Franco

    2016-08-01

    This article reviews the theoretical and experimental work related to the electronic properties of bilayer graphene systems. Three types of bilayer stackings are discussed: the AA, AB, and twisted bilayer graphene. This review covers single-electron properties, effects of static electric and magnetic fields, bilayer-based mesoscopic systems, spin-orbit coupling, dc transport and optical response, as well as spontaneous symmetry violation and other interaction effects. The selection of the material aims to introduce the reader to the most commonly studied topics of theoretical and experimental research in bilayer graphene.

  14. "TPSX: Thermal Protection System Expert and Material Property Database"

    NASA Technical Reports Server (NTRS)

    Squire, Thomas H.; Milos, Frank S.; Rasky, Daniel J. (Technical Monitor)

    1997-01-01

    The Thermal Protection Branch at NASA Ames Research Center has developed a computer program for storing, organizing, and accessing information about thermal protection materials. The program, called Thermal Protection Systems Expert and Material Property Database, or TPSX, is available for the Microsoft Windows operating system. An "on-line" version is also accessible on the World Wide Web. TPSX is designed to be a high-quality source for TPS material properties presented in a convenient, easily accessible form for use by engineers and researchers in the field of high-speed vehicle design. Data can be displayed and printed in several formats. An information window displays a brief description of the material with properties at standard pressure and temperature. A spread sheet window displays complete, detailed property information. Properties which are a function of temperature and/or pressure can be displayed as graphs. In any display the data can be converted from English to SI units with the click of a button. Two material databases included with TPSX are: 1) materials used and/or developed by the Thermal Protection Branch at NASA Ames Research Center, and 2) a database compiled by NASA Johnson Space Center 9JSC). The Ames database contains over 60 advanced TPS materials including flexible blankets, rigid ceramic tiles, and ultra-high temperature ceramics. The JSC database contains over 130 insulative and structural materials. The Ames database is periodically updated and expanded as required to include newly developed materials and material property refinements.

  15. Medicinal chemical properties of successful central nervous system drugs.

    PubMed

    Pajouhesh, Hassan; Lenz, George R

    2005-10-01

    Fundamental physiochemical features of CNS drugs are related to their ability to penetrate the blood-brain barrier affinity and exhibit CNS activity. Factors relevant to the success of CNS drugs are reviewed. CNS drugs show values of molecular weight, lipophilicity, and hydrogen bond donor and acceptor that in general have a smaller range than general therapeutics. Pharmacokinetic properties can be manipulated by the medicinal chemist to a significant extent. The solubility, permeability, metabolic stability, protein binding, and human ether-ago-go-related gene inhibition of CNS compounds need to be optimized simultaneously with potency, selectivity, and other biological parameters. The balance between optimizing the physiochemical and pharmacokinetic properties to make the best compromises in properties is critical for designing new drugs likely to penetrate the blood brain barrier and affect relevant biological systems. This review is intended as a guide to designing CNS therapeutic agents with better drug-like properties. PMID:16489364

  16. How Do I Start a Property Records System?

    ERIC Educational Resources Information Center

    Whyman, Wynne

    2003-01-01

    A property records system organizes data to be utilized by a camp's facilities department and integrated into other areas. Start by deciding what records to keep and allotting the time. Then develop consistent procedures, including organizing data, creating a catalog, making back-up copies, and integrating procedures. Use software tools. A good…

  17. Mass properties measurement system: Dynamics and statics measurements

    NASA Technical Reports Server (NTRS)

    Doty, Keith L.

    1993-01-01

    This report presents and interprets experimental data obtained from the Mass Properties Measurement System (MPMS). Statics measurements yield the center-of-gravity of an unknown mass and dynamics measurements yield its inertia matrix. Observations of the MPMS performance has lead us to specific design criteria and an understanding of MPMS limitations.

  18. Needed: a new system of intellectual property rights.

    PubMed

    Thurow, L C

    1997-01-01

    The world's current system of intellectual property rights has in recent years become unworkable and ineffective. Designed more than 100 years ago to meet the needs of an industrial era, it is inadequate to handle the ownership and distribution of intellectual property generated by the brainpower industries that have come to dominate the world's economy. The prevailing wisdom is that minor tweaking can remedy the problem. But MIT economist Lester Thurow challenges such thinking and calls instead for a new system--one redesigned from the ground up. In making his case for why the old system doesn't work anymore, Thurow lays out the challenges the new system must meet. It must offer incentives to inventors that are strong enough to offset the decline in publicly funded research. At the same time, it must protect the public interest by keeping some intellectual property--basic scientific knowledge, for example--in the public domain. The new system must be flexible enough to deal with the fact that new technologies have created new potential forms of intellectual property rights (Can pieces of a human being be patented?) and have made old rights unenforceable (When books can be downloaded from an electronic library, what does a copyright mean?). And in an increasingly global economy, a new system must meet the needs of both "catch-up" states and "keep-ahead" states. A system that ignores the lesson of history--that every country that has caught up has done so by copying--will be an unenforceable one. PMID:10170334

  19. Soil properties mapping with the DIGISOIL multi-sensor system

    NASA Astrophysics Data System (ADS)

    Grandjean, G.

    2012-04-01

    The multidisciplinary DIGISOIL project aimed to integrate and improve in situ and proximal measurement technologies for the assessment of soil properties and soil degradation indicators, going from the sensing technologies to their integration and their application in (digital) soil mapping (DSM). In order to assess and prevent soil degradation and to benefit from the different ecological, economical and historical functions of the soil in a sustainable way, high resolution and quantitative maps of soil properties are needed. The core objective of the project is to explore and exploit new capabilities of advanced geophysical technologies for answering this societal demand. To this aim, DIGISOIL addresses four issues covering technological, soil science and economic aspects: (i) the validation of geophysical (in situ, proximal and airborne) technologies and integrated pedo-geophysical inversion techniques (mechanistic data fusion) (ii) the relation between the geophysical parameters and the soil properties, (iii) the integration of the derived soil properties for mapping soil functions and soil threats, (iv) the pre-evaluation, standardisation and sub-industrialization of the proposed methodologies, including technical and economical studies related to the societal demand. With respect to these issues, the DIGISOIL project allows to develop, test and validate the most relevant geophysical technologies for mapping soil properties. The system was tested on different field tests, and validated the proposed technologies and solutions for each of the identified methods: geoelectric, GPR, EMI, seismics, magnetic and hyperspectral. After data acquisition systems, sensor geometry, and advanced data processing techniques have been developed and validated, we present now the solutions for going from geophysical data to soil properties maps. For two test sites, located respectively in Luxembourg (LU) and Mugello (IT) a set of soil properties maps have been produced. They give

  20. A system for recording physical properties of clouds

    NASA Technical Reports Server (NTRS)

    Purgold, G. C.; Whitlock, C. H.

    1990-01-01

    Characterization of the physical properties of clouds is an important objective of the FIRE Project intensive field operations (IFO) planned for 1990 thru 1992. Physical properties observed from satellites will be directly compared to ground based observations during this period. The technical information is provided which is required to record local cloud parameters such as type of clouds, direction of travel, layering, and cloud fraction data. Such information should be very useful in analyzing other cloud and meteorological data. A system of the type described was deployed as part of the First Global Surface Radiation Budget Experiment in April 1989.

  1. Carbon-atom wires: 1-D systems with tunable properties

    NASA Astrophysics Data System (ADS)

    Casari, C. S.; Tommasini, M.; Tykwinski, R. R.; Milani, A.

    2016-02-01

    This review provides a discussion of the current state of research on linear carbon structures and related materials based on sp-hybridization of carbon atoms (polyynes and cumulenes). We show that such systems have widely tunable properties and thus represent an intriguing and mostly unexplored field for both fundamental and applied sciences. We discuss the rich interplay between the structural, vibrational, and electronic properties focusing on recent advances and the future perspectives of carbon-atom wires and novel hybrid sp-sp2-carbon architectures.

  2. Carbon-atom wires: 1-D systems with tunable properties.

    PubMed

    Casari, C S; Tommasini, M; Tykwinski, R R; Milani, A

    2016-02-28

    This review provides a discussion of the current state of research on linear carbon structures and related materials based on sp-hybridization of carbon atoms (polyynes and cumulenes). We show that such systems have widely tunable properties and thus represent an intriguing and mostly unexplored field for both fundamental and applied sciences. We discuss the rich interplay between the structural, vibrational, and electronic properties focusing on recent advances and the future perspectives of carbon-atom wires and novel hybrid sp-sp(2)-carbon architectures. PMID:26847474

  3. The properties of the Neckel-Chini VRI system

    NASA Technical Reports Server (NTRS)

    Taylor, Benjamin J.; Joner, Michael D.; Johnson, Scott B.

    1989-01-01

    Cousins (1980) data for 54 of the standard stars of Neckel and Chini (1980) and published measurements are used to investigate the properties of the Neckel-Chini VRI system. For red stars, this system diverges from the Johnson (1962) system, despite frequent claims of identity between the two. The Neckel-Chini and Cousins systems, however, are closely comparable. Both of these conclusions were previously reached in a paper by Bessell (1983); fair to good quantitative agreement with his results are obtained. Reddening ratios, the scatter in the Neckel-Chini standard-star data, and the effect of this scatter on published measurements for program stars, are discussed. Transformations from the Neckel-Chini system to the Cousins system are given.

  4. Volume-controlled hydrologic property measurements in triaxial systems

    USGS Publications Warehouse

    Olsen, Harold W.; Willden, Arthur T.; Kiusalaas, Nicholas J.; Nelson, Karl R.; Poeter, Eileen P.

    1994-01-01

    New capabilities for hydrologic property measurements in triaxial systems include: (1) volume-controlled and simultaneous measurements of hydraulic conductivity and one-dimensional consolidation (or specific storage) of a saturated test specimen; and (2) volume-controlled measurements of hydraulic conductivity, matric potential, and the variation of these properties with the moisture content of an unsaturated test specimen. Data on saturated kaolinite demonstrate simultaneous hydraulic-conductivity and one-dimensional consolidation tests with continuous monitoring of both vertical and horizontal effective stresses. Data on well-graded silty sand demonstrate the feasibility of concurrent constant-flow hydraulic conductivity and mattic potential measurements, and the variation of these properties with moisture content, for undisturbed and unsaturated specimens mounted in triaxial cells. Refinements needed to realize the full potential of these capabilities include a more rigid triaxial cell to minimize compliance, and an improved technique for measuring hydraulic-head differences within an unsaturated test specimen.

  5. Numerical analysis of nonlinear properties of rail fastening systems

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Luo, Y.; Yin, H. P.

    2014-10-01

    Higher demand on vibration isolation of track structure in nowadays leads to a trend of lower stiffness of rail fastening system accompanied with larger deformation of its rubber component. Nonlinear properties of rubber material under large deformation thus should be taken into account. Uniaxial tension, uniaxial compression and planar tension experiments of a rubber material were carried out to defined mathematical material models by using Abaqus. Accuracy of the material model and model coefficients were supported by good agreement between measured and simulated results. A shear type and a bonded compressed type of rail fastening system are designed and produced with the same rubber material. Quasi-static experiment of these two rail fastening systems were performed and simulated as well. Predictions of the preload dependent nonlinear properties of the two different rail fastening systems by Abaqus were found to be in good agreement with experiments. Nonlinearities of the two specimens, due both to the intrinsic rubber material properties and the geometric characteristics, were well analyzed and explained. This is believed to contribute to product designing and geometrical optimization with rubber component under general or local large deformation.

  6. Synthesis and physical properties of some composite systems

    NASA Astrophysics Data System (ADS)

    Pu, Zhengcai

    There are four major parts in this dissertation: (1) investigation of filler-matrix interactions in poly(dimethylsiloxane)/zeolite (PDMS/zeolite) composites, (2) characterization of mechanical and thermal properties of 3-(trimethoxysilyl)propyl methacrylate coated silica (TPM-Si) filled poly(methyl acrylate) (PMA), (3) small angle x-ray scattering studies of chain penetration into cavities of a zeolite in poly(ethyl acrylate)/zeolite (PEA/zeolite) hybrid material, (4) study of hydrolysis kinetics and stability of bis(triethoxysilyl)ethane (BTESE) in water-ethanol solutions by Fourier transform infrared (FTIR) spectroscopy. In the first part of this study, two types of PDMS/zeolite composites with physically or chemically crosslinked networks were prepared through two different approaches: (1) blending hydroxyl-terminated linear PDMS with zeolite and crosslinking PDMS with tetraethylorthosilicate (TEOS); (2) mixing dichlorodimethylsilane with zeolite, and then hydrolyzing and polymerizing the dichlorodimethylsilane with water. The physical properties of the resulting composites, including mechanical properties, swelling properties, and small angle X-ray (SAXS), were measured and compared. It was shown that the PDMS/zeolite composites having PDMS networks differently crosslinked behave differently in many aspects. In the second part of the study, composites of PMA and of TPM-Si with randomly dispersed, regularly dispersed, and aggregated silica were prepared by blending methyl acrylate and TPM-Si, followed by free radical polymerization. Simple tension properties, equibiaxial extension properties, dynamic mechanical properties, and differential scanning calorimetry (DSC) properties of the resulting composites were investigated. It was shown that well-defined relationships exist between the physical properties of the composites and the preparation processes. In the third part of this study, small angle X-ray scattering (SAXS) intensities of PEA/zeolite hybrids were

  7. Engineering Biomaterial Properties for Central Nervous System Applications

    NASA Astrophysics Data System (ADS)

    Rivet, Christopher John

    Biomaterials offer unique properties that are intrinsic to the chemistry of the material itself or occur as a result of the fabrication process; iron oxide nanoparticles are superparamagnetic, which enables controlled heating in the presence of an alternating magnetic field, and a hydrogel and electrospun fiber hybrid material provides minimally invasive placement of a fibrous, artificial extracellular matrix for tissue regeneration. Utilization of these unique properties towards central nervous system disease and dysfunction requires a thorough definition of the properties in concert with full biological assessment. This enables development of material-specific features to elicit unique cellular responses. Iron oxide nanoparticles are first investigated for material-dependent, cortical neuron cytotoxicity in vitro and subsequently evaluated for alternating magnetic field stimulation induced hyperthermia, emulating the clinical application for enhanced chemotherapy efficacy in glioblastoma treatment. A hydrogel and electrospun fiber hybrid material is first applied to a rat brain to evaluate biomaterial interface astrocyte accumulation as a function of hybrid material composition. The hybrid material is then utilized towards increasing functional engraftment of dopaminergic progenitor neural stem cells in a mouse model of Parkinson's disease. Taken together, these two scenarios display the role of material property characterization in development of biomaterial strategies for central nervous system repair and regeneration.

  8. 41 CFR 101-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 41 Public Contracts and Property Management 2 2012-07-01 2012-07-01 false Federal Property Management Regulations System. 101-1.101 Section 101-1.101 Public Contracts and Property Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS GENERAL 1-INTRODUCTION...

  9. 41 CFR 109-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Federal Property Management Regulations System. 109-1.101 Section 109-1.101 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF ENERGY PROPERTY MANAGEMENT REGULATIONS GENERAL 1-INTRODUCTION 1.1-Regulation...

  10. 41 CFR 109-1.5205 - Personal property management system changes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false Personal property management system changes. 109-1.5205 Section 109-1.5205 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF ENERGY PROPERTY MANAGEMENT...

  11. 41 CFR 109-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false Federal Property Management Regulations System. 109-1.101 Section 109-1.101 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF ENERGY PROPERTY MANAGEMENT...

  12. 41 CFR 109-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false Federal Property Management Regulations System. 109-1.101 Section 109-1.101 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF ENERGY PROPERTY MANAGEMENT...

  13. 41 CFR 109-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false Federal Property Management Regulations System. 109-1.101 Section 109-1.101 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF ENERGY PROPERTY MANAGEMENT...

  14. 41 CFR 109-1.5205 - Personal property management system changes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false Personal property management system changes. 109-1.5205 Section 109-1.5205 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF ENERGY PROPERTY MANAGEMENT...

  15. 41 CFR 101-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 41 Public Contracts and Property Management 2 2014-07-01 2012-07-01 true Federal Property Management Regulations System. 101-1.101 Section 101-1.101 Public Contracts and Property Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS GENERAL 1-INTRODUCTION...

  16. 41 CFR 101-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 2 2013-07-01 2012-07-01 true Federal Property Management Regulations System. 101-1.101 Section 101-1.101 Public Contracts and Property Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS GENERAL 1-INTRODUCTION...

  17. 41 CFR 109-1.5205 - Personal property management system changes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false Personal property management system changes. 109-1.5205 Section 109-1.5205 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF ENERGY PROPERTY MANAGEMENT...

  18. 41 CFR 109-1.5205 - Personal property management system changes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false Personal property management system changes. 109-1.5205 Section 109-1.5205 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF ENERGY PROPERTY MANAGEMENT...

  19. 41 CFR 101-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Federal Property Management Regulations System. 101-1.101 Section 101-1.101 Public Contracts and Property Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS GENERAL 1-INTRODUCTION...

  20. 41 CFR 109-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false Federal Property Management Regulations System. 109-1.101 Section 109-1.101 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF ENERGY PROPERTY MANAGEMENT...

  1. 41 CFR 101-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 41 Public Contracts and Property Management 2 2011-07-01 2007-07-01 true Federal Property Management Regulations System. 101-1.101 Section 101-1.101 Public Contracts and Property Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS GENERAL 1-INTRODUCTION...

  2. 41 CFR 109-1.5205 - Personal property management system changes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Personal property management system changes. 109-1.5205 Section 109-1.5205 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF ENERGY PROPERTY MANAGEMENT REGULATIONS GENERAL 1-INTRODUCTION 1.52-Personal...

  3. Statistical analysis of the modal properties of large structural systems.

    NASA Technical Reports Server (NTRS)

    Collins, J. D.; Kennedy, B.; Hart, G. C.

    1971-01-01

    A theory is developed to predict eigenvalue and eigenvector uncertainty in large dynamic models. The uncertainty is based on physical property uncertainty and should not be confused with numerical roundoff, although the method can be extended to include the latter. The theory, when implemented on a computer, is used to analyze the uncertainties in frequencies and mode shapes based on uncertainties in mass, stiffness, modulus of elasticity, etc. The method incorporates a linear statistical model which is quite adequate for handling property uncertainties of 10% or more. The model is not limited to small systems but uses certain statistical assumptions as well as selective matrix manipulations to keep the size of all matrix operations to within the number of degrees of freedom of the system. Examples are given for two longitudinal vibration problems, and the results are supported by a Monte Carlo analysis.

  4. Thermodynamic properties of alloys of the vanadium-nitrogen system

    SciTech Connect

    Lukashenko, G.M.; Khaenko, B.V.; Sidorko, V.R.

    1985-08-01

    This paper discusses the results of work on the thermodynamic properties of alloys of the V-N system studied by measuring the electromotive forces of galvanic concentration cells in KC1NaC1 melts in the range, 953 - 1123/sup 0/K, at nitrogen concentrations in the alloys of less than 50 at.%. As a result of this investigation, partial thermodynamic functions for both components and integral functions of alloy formation in a wide range of compositions have been obtained.

  5. Gouy Interferometry: Properties of Multicomponent System Omega Graphs

    SciTech Connect

    Miller, D G

    2007-01-24

    We consider the properties of {Omega} graphs ({Omega} vs f(z)) obtained from Gouy interferometry on multicomponent systems with constant diffusion coefficients. We show that they must have (a) either a maximum or else a minimum between f(z)=0 and f(z)=1 and (b) an inflection point between the f(z) value at the extremum and f(z)=1. Consequently, an {Omega} graph cannot have both positive and negative {Omega} values.

  6. Hybrid soft computing systems for reservoir PVT properties prediction

    NASA Astrophysics Data System (ADS)

    Khoukhi, Amar

    2012-07-01

    In reservoir engineering, the knowledge of Pressure-Volume-Temperature (PVT) properties is of great importance for many uses, such as well test analyses, reserve estimation, material balance calculations, inflow performance calculations, fluid flow in porous media and the evaluation of new formations for the potential development and enhancement oil recovery projects. The determination of these properties is a complex problem because laboratory-measured properties of rock samples ("cores") are only available from limited and isolated well locations and/or intervals. Several correlation models have been developed to relate these properties to other measures which are relatively abundant. These models include empirical correlations, statistical regression and artificial neural networks (ANNs). In this paper, a comprehensive study is conducted on the prediction of the bubble point pressure and oil formation volume factor using two hybrid of soft computing techniques; a genetically optimised neural network and a genetically enhanced subtractive clustering for the parameter identification of an adaptive neuro-fuzzy inference system. Simulation experiments are provided, showing the performance of the proposed techniques as compared with commonly used regression correlations, including standard artificial neural networks.

  7. Thermophysical and Thermomechanical Properties of Thermal Barrier Coating Systems

    NASA Technical Reports Server (NTRS)

    Zhu, Dongming; Miller, Robert A.

    2000-01-01

    Thermal barrier coatings have been developed for advanced gas turbine and diesel engine applications to improve engine reliability and fuel efficiency. However, the issue of coating durability under high temperature cyclic conditions is still of major concern. The coating failure is closely related to thermal stresses and oxidation in the coating systems. Coating shrinkage cracking resulting from ceramic sintering and creep at high temperatures can further accelerate the coating failure process. The purpose of this paper is to address critical issues such as ceramic sintering and creep, thermal fatigue and their relevance to coating life prediction. Novel test approaches have been established to obtain critical thermophysical and thermomechanical properties of the coating systems under near-realistic temperature and stress gradients encountered in advanced engine systems. Emphasis is placed on the dynamic changes of the coating thermal conductivity and elastic modulus, fatigue and creep interactions, and resulting failure mechanisms during the simulated engine tests. Detailed experimental and modeling results describing processes occurring in the thermal barrier coating systems provide a framework for developing strategies to manage ceramic coating architecture, microstructure and properties.

  8. SCREEN photometric property detection system based on area CCD

    NASA Astrophysics Data System (ADS)

    Yan, Fu-cai; Ye, Wei; Xu, Yu; Wang, Chao; Zhang, Yu-wei

    2011-08-01

    The photometric property detection of screen display is crucial for screen display quality test. Traditional photometry detection technologies were based on photoelectric sensors such as silicon photocell, photo-electric multiplier and CdS, which can detect only some isolated points. To break the limitation of randomness, incompleteness and detection accuracy in current technologies, we designed a screen photometric detection system based on area CCD. The system consists of photometric image sensor, photometric image acquisition hardware and photometric image analyzing software. The photometric image sensor, which adopts optical lens, optical filters and area CCD, adapts its spectrum response property to fit the spectrum luminous efficiency curve V (λ) by adjusting the thickness and quantity of appropriate optical filters. photometric image acquisition hardware adopts the DSP as a core processor to drive the area CCD, to sample, acquire , process and save the image from image sensor, to transmit the image to computer. For real-time performance of transmitting, the hardware system adopts the transmission protocol of USB2.0. The uploaded image will be processed by photometric image analyzing software, and then displayed in real time with detection results. The screen photometric detection technology based on area CCD can detect specifications of the whole screen such as luminance, contrast, onoff ratio and uniformity, breaks the limitation of randomness and incompleteness in current detection technology, exactly and fully reflects the integrated display quality of the whole screen. According to the test results, the accuracy of this system has reached the accuracy level one in China.

  9. Temperature of a small quantum system as an internal property

    NASA Astrophysics Data System (ADS)

    Wang, Jiaozi; Wang, Wenge

    Equilibration of small quantum systems is a topic of current interest both theoretically and experimentally. In this work, we study the extent to which a temperature can be assigned to a small quantum (chaotic) system as an internal property, but not as a property of any large environment. Specifically, we study a total system, which is composed of an Ising chain in a nonhomogeneous transverse field and an additional spin coupled to one of the spins in the chain. The additional spin can be used as a probe to detect local temperature of the chain. The total system lies in a pure state under unitary evolution and initial state of the chain is prepared in a typical state within an energy shell. Our numerical simulations show that the reduced density matrix of the probe spin approaches canonical states with similar temperatures at different locations of the chain beyond a relaxation time, and the results are close to the theoretical prediction given by the statistical mechanics in the thermodynamic limit, namely β =∂lnρ/(E) ∂E with ρ (E) being the density of states. We also study effects due to finite size of the chain, including the dependence on initial state of the probe and difference of numerically-obtain temperature from theoretical results.

  10. Fractal variability: An emergent property of complex dissipative systems

    NASA Astrophysics Data System (ADS)

    Seely, Andrew J. E.; Macklem, Peter

    2012-03-01

    The patterns of variation of physiologic parameters, such as heart and respiratory rate, and their alteration with age and illness have long been under investigation; however, the origin and significance of scale-invariant fractal temporal structures that characterize healthy biologic variability remain unknown. Quite independently, atmospheric and planetary scientists have led breakthroughs in the science of non-equilibrium thermodynamics. In this paper, we aim to provide two novel hypotheses regarding the origin and etiology of both the degree of variability and its fractal properties. In a complex dissipative system, we hypothesize that the degree of variability reflects the adaptability of the system and is proportional to maximum work output possible divided by resting work output. Reductions in maximal work output (and oxygen consumption) or elevation in resting work output (or oxygen consumption) will thus reduce overall degree of variability. Second, we hypothesize that the fractal nature of variability is a self-organizing emergent property of complex dissipative systems, precisely because it enables the system's ability to optimally dissipate energy gradients and maximize entropy production. In physiologic terms, fractal patterns in space (e.g., fractal vasculature) or time (e.g., cardiopulmonary variability) optimize the ability to deliver oxygen and clear carbon dioxide and waste. Examples of falsifiability are discussed, along with the need to further define necessary boundary conditions. Last, as our focus is bedside utility, potential clinical applications of this understanding are briefly discussed. The hypotheses are clinically relevant and have potential widespread scientific relevance.

  11. Fractal variability: an emergent property of complex dissipative systems.

    PubMed

    Seely, Andrew J E; Macklem, Peter

    2012-03-01

    The patterns of variation of physiologic parameters, such as heart and respiratory rate, and their alteration with age and illness have long been under investigation; however, the origin and significance of scale-invariant fractal temporal structures that characterize healthy biologic variability remain unknown. Quite independently, atmospheric and planetary scientists have led breakthroughs in the science of non-equilibrium thermodynamics. In this paper, we aim to provide two novel hypotheses regarding the origin and etiology of both the degree of variability and its fractal properties. In a complex dissipative system, we hypothesize that the degree of variability reflects the adaptability of the system and is proportional to maximum work output possible divided by resting work output. Reductions in maximal work output (and oxygen consumption) or elevation in resting work output (or oxygen consumption) will thus reduce overall degree of variability. Second, we hypothesize that the fractal nature of variability is a self-organizing emergent property of complex dissipative systems, precisely because it enables the system's ability to optimally dissipate energy gradients and maximize entropy production. In physiologic terms, fractal patterns in space (e.g., fractal vasculature) or time (e.g., cardiopulmonary variability) optimize the ability to deliver oxygen and clear carbon dioxide and waste. Examples of falsifiability are discussed, along with the need to further define necessary boundary conditions. Last, as our focus is bedside utility, potential clinical applications of this understanding are briefly discussed. The hypotheses are clinically relevant and have potential widespread scientific relevance. PMID:22462984

  12. Interfacial and mechanical properties of self-assembling systems

    NASA Astrophysics Data System (ADS)

    Carvajal, Daniel

    Self-assembly is a fascinating phenomena where interactions between small subunits allow them to aggregate and form complex structures that can span many length scales. These self-assembled structures are especially important in biology where they are necessary for life as we know it. This dissertation is a study of three very different self-assembling systems, all of which have important connections to biology and biological systems. Drop shape analysis was used to study the interfacial assembly of amphiphilic block copolymers at the oil/water interface. When biologically functionalyzed copolymers are used, this system can serve as a model for receptor-ligand interactions that are used by cells to perform many activities, such as interact with their surroundings. The physical properties of a self-assembling membrane system were quantified using membrane inflation and swelling experiments. These types of membranes may have important applications in medicine such as drug eluting (growth factor eluting) scaffolds to aid in wound healing. The factors affecting the properties of bis(leucine) oxalamide gels were also explored. We believe that this particular system will serve as an appropriate model for biological gels that are made up of fiber-like and/or rod-like structures. During the course of the research presented in this dissertation, many new techniques were developed specifically to allow/aid the study of these distinct self-assembling systems. For example, numerical methods were used to predict drop stability for drop shape analysis experiments and the methods used to create reproducibly create self-assembling membranes were developed specifically for this purpose. The development of these new techniques is an integral part of the thesis and should aid future students who work on these projects. A number ongoing projects and interesting research directions for each one of the projects is also presented.

  13. 25 CFR 900.54 - Should the property management system prescribe internal controls?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 2 2014-04-01 2014-04-01 false Should the property management system prescribe internal... EDUCATION ASSISTANCE ACT Standards for Tribal or Tribal Organization Management Systems Property Management System Standards § 900.54 Should the property management system prescribe internal controls?...

  14. 25 CFR 900.53 - What kind of records shall the property management system maintain?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 2 2014-04-01 2014-04-01 false What kind of records shall the property management system... EDUCATION ASSISTANCE ACT Standards for Tribal or Tribal Organization Management Systems Property Management System Standards § 900.53 What kind of records shall the property management system maintain?...

  15. 25 CFR 900.54 - Should the property management system prescribe internal controls?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 2 2012-04-01 2012-04-01 false Should the property management system prescribe internal... EDUCATION ASSISTANCE ACT Standards for Tribal or Tribal Organization Management Systems Property Management System Standards § 900.54 Should the property management system prescribe internal controls?...

  16. 25 CFR 900.54 - Should the property management system prescribe internal controls?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Should the property management system prescribe internal... EDUCATION ASSISTANCE ACT Standards for Tribal or Tribal Organization Management Systems Property Management System Standards § 900.54 Should the property management system prescribe internal controls?...

  17. On the Orthocomplementation of State-Property of Contextual Systems

    NASA Astrophysics Data System (ADS)

    D'Hooghe, Bart

    2014-03-01

    We describe a model in which the maximal change of state of the system due to interaction with the measurement context is controlled by a parameter which corresponds with the number N of possible outcomes in an experiment. In the limit N = 2 the system reduces to a model for the spin measurements on a quantum spin-frac{1}{2} particle. This model fits in the hidden measurement approach to quantum mechanics in which quantum probabilities are explained as due to an uncontrollable fluctuation in the measurement process. In the limit N → ∞ the system is classical, i.e. the experiments are deterministic and its set of properties is a Boolean lattice. For intermediate situations the change of state due to measurement is neither `maximal' (i.e. quantum) nor `zero' (i.e. classical). We show that two of the axioms used in Piron's representation theorem for quantum mechanics are violated, namely the covering law and weak modularity. Next, we discuss a modified version of the model for which it is even impossible to define an orthocomplementation on the set of properties. Another interesting feature for the intermediate situations of this model is that the probability of a state transition in general not only depends on the angular distance between the two states but also on the measurement context which induces the state transition. Therefore our models also shed new light on Gleason's theorem and suggest that transition probability maybe is not a secondary concept which can be derived from the structure on the set of states and properties, but instead should be regarded as a primitive concept by its own right for which the measurement context is crucial.

  18. Control System Upgrade for a Mass Property Measurement Facility

    NASA Technical Reports Server (NTRS)

    Chambers, William; Hinkle, R. Kenneth (Technical Monitor)

    2002-01-01

    The Mass Property Measurement Facility (MPMF) at the Goddard Space Flight Center has undergone modifications to ensure the safety of Flight Payloads and the measurement facility. The MPMF has been technically updated to improve reliability and increase the accuracy of the measurements. Modifications include the replacement of outdated electronics with a computer based software control system, the addition of a secondary gas supply in case of a catastrophic failure to the gas supply and a motor controlled emergency stopping feature instead of a hard stop.

  19. Dielectric properties, screening and compressibility for bilayer systems

    NASA Astrophysics Data System (ADS)

    Kyrkos, Stamatios

    We examine the dielectric properties, screening and compressibility for charged particle bilayer systems. In the process, we first review the screening problem of a charged impurity in a one component plasma in 3D, 2D and bilayer systems within the framework of the linear response theory, both for weak and strong coupling. In the weakly coupled domain, the approach is based on the RPA response matrix. The behavior that emerges is marked by an unexpected nonmonotonic dependence of the screened charges and potential on the layer separation. In the strong coupling domain we use the link provided by the classical fluctuation dissipation theorem between the response matrix and the structure function matrix that was independently calculated by W. L. Slattery, et al. and S. Chakravatry et al . What emerges is a screening scenario where one layer exhibits an overscreening and the other an antiscreening behavior. To go beyond the linear response approximation, we also examine, within the RPA approach, higher order (quadratic) contributions to the screening both in 2D and 3D, based on the quadratic density response previously calculated by J. M. Rommel. These contributions are expected to play an important role at higher coupling or higher Z values. Finally, since the response function and the screening behavior are intimately linked to the isothermal compressibility of the system, we examine the inverse compressibility matrix and its properties for a bilayer system, both within the Debye approximation and for strongly coupled systems. The later as based on previously obtained hypernetted chain (HNC) and molecular dynamics results by G. D. Doolen and Z. Donko.

  20. Effects of carbon nanoparticles on properties of thermoset polymer systems

    NASA Astrophysics Data System (ADS)

    Movva, Siva Subramanyam

    Polymer nanocomposites are novel materials in which at least one of the dimensions of the reinforcing material is on the order of 100 nm or less. While thermoplastic nanocomposites have been studied very widely, there are fewer studies concerning the effect of nanoparticles on thermoset systems. Low temperature cure thermoset systems are very important for many important applications. In this study, the processing, mechanical and thermal properties and reaction kinetics of carbon nanofiber (CNF) and/or carbon nanotubes (CNT) reinforced low temperature vinyl ester and epoxy nanocomposites were studied. In the first part, the processing challenge of incorporating CNFs into conventional fiber reinforced composites made by Vacuum infusion resin transfer molding (VARTM) was addressed by a new technique. The CNFs are pre-bound on the long fiber mats, instead of mixing them in the polymer resin, thereby eliminating several processing drawbacks. The resulting hybrid nanocomposites showed significant improvements in tensile, flexural and thermal properties. The effect of CNFs on the mold filling in VARTM was also studied and shown to follow the Darcy's law. In the second part, the effect of CNFs on the low temperature cure kinetics of vinyl ester and epoxy resins is studied using a thermal analysis technique, namely Differential scanning calorimetry (DSC). The effect of CNFs on the free radical polymerization of vinyl esters was found to be very complex as the CNFs interact with the various curing ingredients in the formulation. Specifically, the interaction effects of CNFs and the inhibitor were studied and a reaction mechanism was proposed to explain the observed phenomenon. The effect of surface modification of the carbon nanoparticles on the cure kinetics of wind-blade epoxy was studied. The surface functionalization reduced the activation energy of the epoxy reaction and was found to have an acceleration effect on the cure kinetics of epoxy resin at room temperature

  1. A PET system design by using mixed detectors: resolution properties

    NASA Astrophysics Data System (ADS)

    Liu, Jingjing; Kao, Chien-Min; Gu, Shuguo; Xiao, Peng; Xie, Qingguo

    2014-07-01

    We investigate a cylindrical positron emission tomography (PET) system design strategy that employs two groups of detectors with different resolutions. The reason for considering this strategy is the observation that in many tasks one would want a higher resolution in a targeted region, which contains lesions or organs of interest, than that in the rest of the subject. Although one can design a PET system to meet the highest resolution required by the imaging task, this is not cost efficient because the superior resolution outside the target region is not needed. To address this issue, investigators have proposed the concept of an insert, in which a high-resolution detector (HRD) is inserted into a parent PET system to locally increase the image resolution. In this paper, we examine an alternative strategy in which the system is made of one arc of normal-resolution detectors with respect to, for example, whole-body imaging and one arc of HRDs. By using Monte Carlo simulations, we study the resolution properties of this system design and examine how they are affected by the location and size of the HRD arc. Our results show that the region obtained by connecting the edges of the HRD arc to the center of the field-of-view (FOV) can have significantly better resolution than that in the rest of the FOV, as well as better resolution uniformity.

  2. A PET system design by using mixed detectors: resolution properties.

    PubMed

    Liu, Jingjing; Kao, Chien-Min; Gu, Shuguo; Xiao, Peng; Xie, Qingguo

    2014-07-01

    We investigate a cylindrical positron emission tomography (PET) system design strategy that employs two groups of detectors with different resolutions. The reason for considering this strategy is the observation that in many tasks one would want a higher resolution in a targeted region, which contains lesions or organs of interest, than that in the rest of the subject. Although one can design a PET system to meet the highest resolution required by the imaging task, this is not cost efficient because the superior resolution outside the target region is not needed. To address this issue, investigators have proposed the concept of an insert, in which a high-resolution detector (HRD) is inserted into a parent PET system to locally increase the image resolution. In this paper, we examine an alternative strategy in which the system is made of one arc of normal-resolution detectors with respect to, for example, whole-body imaging and one arc of HRDs. By using Monte Carlo simulations, we study the resolution properties of this system design and examine how they are affected by the location and size of the HRD arc. Our results show that the region obtained by connecting the edges of the HRD arc to the center of the field-of-view (FOV) can have significantly better resolution than that in the rest of the FOV, as well as better resolution uniformity. PMID:24910321

  3. Machine learning strategies for systems with invariance properties

    SciTech Connect

    Ling, Julia; Jones, Reese E.; Templeton, Jeremy Alan

    2016-01-01

    Here, in many scientific fields, empirical models are employed to facilitate computational simulations of engineering systems. For example, in fluid mechanics, empirical Reynolds stress closures enable computationally-efficient Reynolds-Averaged Navier-Stokes simulations. Likewise, in solid mechanics, constitutive relations between the stress and strain in a material are required in deformation analysis. Traditional methods for developing and tuning empirical models usually combine physical intuition with simple regression techniques on limited data sets. The rise of high-performance computing has led to a growing availability of high-fidelity simulation data, which open up the possibility of using machine learning algorithms, such as random forests or neural networks, to develop more accurate and general empirical models. A key question when using data-driven algorithms to develop these models is how domain knowledge should be incorporated into the machine learning process. This paper will specifically address physical systems that possess symmetry or invariance properties. Two different methods for teaching a machine learning model an invariance property are compared. In the first , a basis of invariant inputs is constructed, and the machine learning model is trained upon this basis, thereby embedding the invariance into the model. In the second method, the algorithm is trained on multiple transformations of the raw input data until the model learns invariance to that transformation. Results are discussed for two case studies: one in turbulence modeling and one in crystal elasticity. It is shown that in both cases embedding the invariance property into the input features yields higher performance with significantly reduced computational training costs.

  4. Machine learning strategies for systems with invariance properties

    NASA Astrophysics Data System (ADS)

    Ling, Julia; Jones, Reese; Templeton, Jeremy

    2016-08-01

    In many scientific fields, empirical models are employed to facilitate computational simulations of engineering systems. For example, in fluid mechanics, empirical Reynolds stress closures enable computationally-efficient Reynolds Averaged Navier Stokes simulations. Likewise, in solid mechanics, constitutive relations between the stress and strain in a material are required in deformation analysis. Traditional methods for developing and tuning empirical models usually combine physical intuition with simple regression techniques on limited data sets. The rise of high performance computing has led to a growing availability of high fidelity simulation data. These data open up the possibility of using machine learning algorithms, such as random forests or neural networks, to develop more accurate and general empirical models. A key question when using data-driven algorithms to develop these empirical models is how domain knowledge should be incorporated into the machine learning process. This paper will specifically address physical systems that possess symmetry or invariance properties. Two different methods for teaching a machine learning model an invariance property are compared. In the first method, a basis of invariant inputs is constructed, and the machine learning model is trained upon this basis, thereby embedding the invariance into the model. In the second method, the algorithm is trained on multiple transformations of the raw input data until the model learns invariance to that transformation. Results are discussed for two case studies: one in turbulence modeling and one in crystal elasticity. It is shown that in both cases embedding the invariance property into the input features yields higher performance at significantly reduced computational training costs.

  5. Machine learning strategies for systems with invariance properties

    DOE PAGESBeta

    Ling, Julia; Jones, Reese E.; Templeton, Jeremy Alan

    2016-05-06

    Here, in many scientific fields, empirical models are employed to facilitate computational simulations of engineering systems. For example, in fluid mechanics, empirical Reynolds stress closures enable computationally-efficient Reynolds-Averaged Navier-Stokes simulations. Likewise, in solid mechanics, constitutive relations between the stress and strain in a material are required in deformation analysis. Traditional methods for developing and tuning empirical models usually combine physical intuition with simple regression techniques on limited data sets. The rise of high-performance computing has led to a growing availability of high-fidelity simulation data, which open up the possibility of using machine learning algorithms, such as random forests or neuralmore » networks, to develop more accurate and general empirical models. A key question when using data-driven algorithms to develop these models is how domain knowledge should be incorporated into the machine learning process. This paper will specifically address physical systems that possess symmetry or invariance properties. Two different methods for teaching a machine learning model an invariance property are compared. In the first , a basis of invariant inputs is constructed, and the machine learning model is trained upon this basis, thereby embedding the invariance into the model. In the second method, the algorithm is trained on multiple transformations of the raw input data until the model learns invariance to that transformation. Results are discussed for two case studies: one in turbulence modeling and one in crystal elasticity. It is shown that in both cases embedding the invariance property into the input features yields higher performance with significantly reduced computational training costs.« less

  6. Thermo-optical properties of gold nanoparticles in colloidal systems

    NASA Astrophysics Data System (ADS)

    Ortega, M. A.; Rodriguez, L.; Castillo, J.; Piscitelli, V.; Fernandez, A.; Echevarria, L.

    2008-10-01

    In this work, we report the thermo-optical properties of nanoparticles in colloidal suspensions. Spherical gold nanoparticles obtained by laser ablation in condensed media were characterized using thermal lens spectroscopy pumping at 532 nm with a 10 ns pulse laser-Nd-YAG system. The obtained nanoparticles were stabilized in the time by surfactants (sodium dodecyl sulfate or SDS) in water with different molar concentrations. The morphology and size of the gold nanoparticles were determined by transmission electron microscopy (TEM) and UV-visible techniques. The plasmonic resonance bands in gold nanoparticles are responsible for the light optical absorption, and the positions of the absorption maximum and bandwidth in the UV-visible spectra are given by the morphological characteristics of these systems. The thermo-optical constants such as thermal diffusion, thermal diffusivity, and (dn/dT) are functions of the nanoparticle sizes and the dielectric function of the media. For these reasons, the thermal lens (TL) signal is also dependent on nanoparticle sizes. An analysis of the TL signal of the nanoparticles reveals the existence of an inverse dependence between the thermo-optical functions and the size. This methodology can be used in order to evaluate these systems and characterize nanoparticles in different media. These results are expected to have an impact in bioimaging, biosensors, and other technological applications such as cooling systems.

  7. 48 CFR 252.245-7003 - Contractor Property Management System Administration.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... AND CONTRACT CLAUSES Text of Provisions And Clauses 252.245-7003 Contractor Property Management System Administration. As prescribed in 245.107(4), insert the following clause: Contractor Property Management System Administration (APR 2012) (a) Definitions. As used in this clause— Acceptable property management system means...

  8. 48 CFR 652.245-70 - Status of Property Management System.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Status of Property Management System. As prescribed in 645.107-70(a), insert the following provision: Status of Property Management System (DEC 2013) (a) When used in this provision, government-furnished... shall include in their quote or offer: (1) Whether the offeror's property management system that will...

  9. 48 CFR 252.245-7003 - Contractor Property Management System Administration.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... AND CONTRACT CLAUSES Text of Provisions And Clauses 252.245-7003 Contractor Property Management System Administration. As prescribed in 245.107(4), insert the following clause: Contractor Property Management System Administration (APR 2012) (a) Definitions. As used in this clause— Acceptable property management system means...

  10. 48 CFR 252.245-7003 - Contractor Property Management System Administration.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... AND CONTRACT CLAUSES Text of Provisions And Clauses 252.245-7003 Contractor Property Management System Administration. As prescribed in 245.107, insert the following clause: CONTRACTOR PROPERTY MANAGEMENT SYSTEM ADMINISTRATION (MAY 2011) (a) Definitions. As used in this clause— Acceptable property management system means...

  11. 48 CFR 252.245-7003 - Contractor Property Management System Administration.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... AND CONTRACT CLAUSES Text of Provisions And Clauses 252.245-7003 Contractor Property Management System Administration. As prescribed in 245.107(4), insert the following clause: Contractor Property Management System Administration (APR 2012) (a) Definitions. As used in this clause— Acceptable property management system means...

  12. 25 CFR 900.53 - What kind of records shall the property management system maintain?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... EDUCATION ASSISTANCE ACT Standards for Tribal or Tribal Organization Management Systems Property Management System Standards § 900.53 What kind of records shall the property management system maintain? The... 25 Indians 2 2011-04-01 2011-04-01 false What kind of records shall the property management...

  13. 25 CFR 900.53 - What kind of records shall the property management system maintain?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... EDUCATION ASSISTANCE ACT Standards for Tribal or Tribal Organization Management Systems Property Management System Standards § 900.53 What kind of records shall the property management system maintain? The... 25 Indians 2 2012-04-01 2012-04-01 false What kind of records shall the property management...

  14. 25 CFR 900.53 - What kind of records shall the property management system maintain?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... EDUCATION ASSISTANCE ACT Standards for Tribal or Tribal Organization Management Systems Property Management System Standards § 900.53 What kind of records shall the property management system maintain? The... 25 Indians 2 2010-04-01 2010-04-01 false What kind of records shall the property management...

  15. Impact of fuel properties on advanced power systems

    SciTech Connect

    Sondreal, E.A.; Jones, M.L.; Hurley, J.P.; Benson, S.A.; Willson, W.G.

    1995-12-01

    Advanced coal-fired combined-cycle power systems currently in development and demonstration have the goal of increasing generating efficiency to a level approaching 50% while reducing the cost of electricity from new plants by 20% and meeting stringent standards on emissions of SO{sub x} NO{sub x} fine particulates, and air toxic metals. Achieving these benefits requires that clean hot gas be delivered to a gas turbine at a temperature approaching 1350{degrees}C, while minimizing energy losses in the gasification, combustion, heat transfer, and/or gas cleaning equipment used to generate the hot gas. Minimizing capital cost also requires that the different stages of the system be integrated as simply and compactly as possible. Second-generation technologies including integrated gasification combined cycle (IGCC), pressurized fluidized-bed combustion (PFBC), externally fired combined cycle (EFCC), and other advanced combustion systems rely on different high-temperature combinations of heat exchange, gas filtration, and sulfur capture to meet these requirements. This paper describes the various properties of lignite and brown coals.

  16. Metabolic Compartmentation – A System Level Property of Muscle Cells

    PubMed Central

    Saks, Valdur; Beraud, Nathalie; Wallimann, Theo

    2008-01-01

    Problems of quantitative investigation of intracellular diffusion and compartmentation of metabolites are analyzed. Principal controversies in recently published analyses of these problems for the living cells are discussed. It is shown that the formal theoretical analysis of diffusion of metabolites based on Fick's equation and using fixed diffusion coefficients for diluted homogenous aqueous solutions, but applied for biological systems in vivo without any comparison with experimental results, may lead to misleading conclusions, which are contradictory to most biological observations. However, if the same theoretical methods are used for analysis of actual experimental data, the apparent diffusion constants obtained are orders of magnitude lower than those in diluted aqueous solutions. Thus, it can be concluded that local restrictions of diffusion of metabolites in a cell are a system-level properties caused by complex structural organization of the cells, macromolecular crowding, cytoskeletal networks and organization of metabolic pathways into multienzyme complexes and metabolons. This results in microcompartmentation of metabolites, their channeling between enzymes and in modular organization of cellular metabolic networks. The perspectives of further studies of these complex intracellular interactions in the framework of Systems Biology are discussed. PMID:19325782

  17. Processing and Properties of a Phenolic Composite System

    NASA Technical Reports Server (NTRS)

    Hou, Tan-Hung; Bai, J. M.; Baughman, James M.

    2006-01-01

    Phenolic resin systems generate water as a reaction by-product via condensation reactions during curing at elevated temperatures. In the fabrication of fiber reinforced phenolic resin matrix composites, volatile management is crucial in producing void-free quality laminates. A commercial vacuum-bag moldable phenolic prepreg system was selected for this study. The traditional single-vacuum-bag (SVB) process was unable to manage the volatiles effectively, resulting in inferior voidy laminates. However, a double vacuum bag (DVB) process was shown to afford superior volatile management and consistently yielded void-free quality parts. The DVB process cure cycle (temperature /pressure profiles) for the selected composite system was designed, with the vacuum pressure application point carefully selected, to avoid excessive resin squeeze-outs and achieve the net shape and target resin content in the final consolidated laminate parts. Laminate consolidation quality was characterized by optical photomicrography for the cross sections and measurements of mechanical properties. A 40% increase in short beam shear strength, 30% greater flexural strength, 10% higher tensile and 18% higher compression strengths were obtained in composite laminates fabricated by the DVB process.

  18. Understanding and Exploiting Spatial Properties of System Failures on Extreme-Scale HPC Systems

    SciTech Connect

    Tiwari, Devesh; Rogers, James H; Maxwell, Don E

    2015-01-01

    As we approach exascale, the scientific simulations are expected to experience more interruptions due to increased system failures. Designing better HPC resilience techniques requires understanding the key characteristics of system failures on these systems. While temporal properties of system failures on HPC systems have been well-investigated, there is limited understanding about the spatial characteristics of system failures and its impact on the resilience mechanisms. Therefore, we examine the spatial characteristics and behavior of system failures. We investigate the interaction between spatial and temporal characteristics of failures and its implications for system operations and resilience mechanisms on large-scale HPC systems. We show that system failures have spatial locality at different granularity in the system; study impact of different failure-types; and investigate the correlation among different failure-types. Finally, we propose a novel scheme that exploits the spatial locality in failures to improve application and system performance. Our evaluation shows that the proposed scheme significantly improves the system performance in a dynamic and production-level HPC system.

  19. Investigation of structural and electrical properties of mixed ferrite system

    SciTech Connect

    Astik, Nidhi M. Jha, Prafulla K.

    2015-05-15

    In the present work, structural and electrical properties of mixed ferrite systems are studied. As prepared compound of Co{sub 0.85}Ca{sub 0.15-y}Cd{sub y}Fe{sub 2}O{sub 4} (y=0.10, 0.15) is synthesized in polycrystalline form, using the stoichiometric mixture of oxides with conventional standard ceramic route with double sintering at 950°C and 1100°C and characterized by X-ray diffraction. The X-ray diffraction pattern confirms the presence of cubic (FCC) structure. The sharp intensified peaks in X-ray diffraction pattern clearly indicate the completeness of reaction.

  20. Room temperature mechanical properties of shuttle thermal protection system materials

    NASA Technical Reports Server (NTRS)

    Sawyer, J. W.; Rummler, D. R.

    1980-01-01

    Tests were conducted at room temperature to determine the mechanical properties and behavior of materials used for the thermal protection system of the space shuttle. The materials investigated include the LI-900 RSI tiles, the RTV-560 adhesive and the .41 cm (.16 thick) strain isolator pad (SIP). Tensile and compression cyclic loading tests were conducted on the SIP material and stress-strain curves obtained for various proof loads and load cyclic conditioning. Ultimate tensile and shear tests were conducted on the RSI, RTV, and SIP materials. The SIP material exhibits highly nonlinear stress-strain behavior, increased tangent modulus and ultimate tensile strength with increased loading rate, and large short time load relaxation and moderate creep behavior. Proof and cyclic load conditioning of the SIP results in permanent deformation of the material, hysteresis effects, and much higher tensile tangent modulus values at large strains.

  1. Exploring the properties of the DDO system using synthetic colors

    NASA Astrophysics Data System (ADS)

    Tripicco, Michael J.; Bell, R. A.

    1991-08-01

    The properties of the David Dunlap Observatory (DDO) system (which uses bandpasses centered at about 3450, 3800, 4180, 4250, 4500, 4850, and 5150 A, referred to as 35, 38, 41, 42, 45, 48, and 51 filters) are explored by applying synthetic colors. Using DDO colors for a sample of stars for which spectrophotometric data were reported by Gunn and Stryker (1983), the correctness of the transmission profiles of the filters was established. It is shown that the presence of MgH lines in the 48 bandpass is an important reason why cool dwarfs and giants are separated in the C(45-48) vs C(42-45) diagram. It was found that including SiH lines in the spectra improved the agreement between observed and computed C(41-45) colors for dwarfs.

  2. 25 CFR 900.52 - What type of property is the property management system required to track?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false What type of property is the property management system required to track? 900.52 Section 900.52 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR, AND INDIAN HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES CONTRACTS UNDER THE INDIAN SELF-DETERMINATION AND EDUCATION ASSISTANCE...

  3. 7 CFR 1955.56 - Real property located in Coastal Barrier Resources System (CBRS).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 14 2013-01-01 2013-01-01 false Real property located in Coastal Barrier Resources... SERVICE AGENCY, DEPARTMENT OF AGRICULTURE (CONTINUED) PROGRAM REGULATIONS (CONTINUED) PROPERTY MANAGEMENT Management of Property § 1955.56 Real property located in Coastal Barrier Resources System (CBRS)....

  4. 7 CFR 1955.56 - Real property located in Coastal Barrier Resources System (CBRS).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 14 2011-01-01 2011-01-01 false Real property located in Coastal Barrier Resources... SERVICE AGENCY, DEPARTMENT OF AGRICULTURE (CONTINUED) PROGRAM REGULATIONS (CONTINUED) PROPERTY MANAGEMENT Management of Property § 1955.56 Real property located in Coastal Barrier Resources System (CBRS)....

  5. 7 CFR 1955.56 - Real property located in Coastal Barrier Resources System (CBRS).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 14 2010-01-01 2009-01-01 true Real property located in Coastal Barrier Resources... SERVICE AGENCY, DEPARTMENT OF AGRICULTURE (CONTINUED) PROGRAM REGULATIONS (CONTINUED) PROPERTY MANAGEMENT Management of Property § 1955.56 Real property located in Coastal Barrier Resources System (CBRS)....

  6. System Report for the Optical Properties Monitor (OPM) Experiment

    NASA Technical Reports Server (NTRS)

    Hummer, L.

    2001-01-01

    This systems report describes how the Optical Properties Monitor (OPM) experiment was developed. Pertinent design parameters are discussed, along with mission information and system requirements to successfully complete the mission. Environmental testing was performed on the OPM to certify it for spaceflight. This testing included vibration, thermal vacuum, electromagnetic interference and conductance, and toxicity tests. Instrument and monitor subsystem performances, including the reflectometer, vacuum ultraviolet, total integrated scatter, atomic oxygen monitor, irradiance monitor, and molecular contamination monitor during the mission are discussed. The OPM experiment was launched aboard the Space Shuttle on mission STS-81 in January 1997 and transferred to the Mir space station. An extravehicular activity (EVA) was performed in April 1997 to attach the OPM experiment to the outside of the Mir/Shuttle Docking Module for space environment exposure. The OPM conducted in situ measurements of a number of material samples. These data may be found in the OPM Science Report. OPM was retrieved during an EVA in January 1998 and was returned to Earth on board the Space Shuttle on mission STS-89.

  7. Integrability properties of a coupled KdV system and its supersymmetric extension

    NASA Astrophysics Data System (ADS)

    Sotomayor, Adrián; Restuccia, Alvaro

    2016-05-01

    We discuss several integrability properties of a coupled KdV system. We obtain a new generalization of the already known static solutions for the system. We then consider the supersymmetric extension of the coupled KdV system, it is a new integrable system. We show that for particular Grassmann algebras the system is the limit of a Clifford algebra valued system with nice stability properties. We briefly discuss the hamiltonian structures of this supersymmetric integrable system.

  8. On the Orthocomplementation of State-Property-Systems of Contextual Systems

    NASA Astrophysics Data System (ADS)

    D'Hooghe, Bart

    2010-12-01

    We adopt an operational approach to quantum mechanics in which a physical system is defined by the mathematical structure of its set of states and properties. We present a model in which the maximal change of state of the system due to interaction with the measurement context is controlled by a parameter which corresponds with the number N of possible outcomes in an experiment. In the case N=2 the system reduces to a model for the spin measurements on a quantum spin-1/2 particle. In the limit N→∞ the system is classical, i.e. the experiments are deterministic and its set of properties is a Boolean lattice. For intermediate situations the change of state due to measurement is neither ‘maximal’ (i.e. quantum) nor ‘zero’ (i.e. classical). We show that two of the axioms used in Piron’s representation theorem for quantum mechanics are violated, namely the covering law and weak modularity. Next, we discuss a modified version of the model for which it is even impossible to define an orthocomplementation on the set of properties. Another interesting feature for the intermediate situations of this model is that the probability of a state transition in general not only depends on the two states involved, but also on the measurement context which induces the state transition.

  9. Test system accurately determines tensile properties of irradiated metals at cryogenic temperatures

    NASA Technical Reports Server (NTRS)

    Levine, P. J.; Skalka, R. J.; Vandergrift, E. F.

    1967-01-01

    Modified testing system determines tensile properties of irradiated brittle-type metals at cryogenic temperatures. The system includes a lightweight cryostat, split-screw grips, a universal joint, and a special temperature control system.

  10. Periodic properties of the histaminergic system of the mouse brain.

    PubMed

    Rozov, Stanislav V; Zant, Janneke C; Karlstedt, Kaj; Porkka-Heiskanen, Tarja; Panula, Pertti

    2014-01-01

    Brain histamine is involved in the regulation of the sleep-wake cycle and alertness. Despite the widespread use of the mouse as an experimental model, the periodic properties of major markers of the mouse histaminergic system have not been comprehensively characterized. We analysed the daily levels of histamine and its first metabolite, 1-methylhistamine, in different brain structures of C57BL/6J and CBA/J mouse strains, and the mRNA level and activity of histidine decarboxylase and histamine-N-methyltransferase in C57BL/6J mice. In the C57BL/6J strain, histamine release, assessed by in vivo microdialysis, underwent prominent periodic changes. The main period was 24 h peaking during the activity period. Additional 8 h periods were also observed. The release was highly positively correlated with active wakefulness, as shown by electroencephalography. In both mouse strains, tissue histamine levels remained steady for 24 h in all structures except for the hypothalamus of CBA/J mice, where 24-h periodicity was observed. Brain tissue 1-methylhistamine levels in both strains reached their maxima in the periods of activity. The mRNA level of histidine decarboxylase in the tuberomamillary nucleus and the activities of histidine decarboxylase and histamine-N-methyltransferase in the striatum and cortex did not show a 24-h rhythm, whereas in the hypothalamus the activities of both enzymes had a 12-h periodicity. These results show that the activities of histamine-metabolizing enzymes are not under simple direct circadian regulation. The complex and non-uniform temporal patterns of the histaminergic system of the mouse brain suggest that histamine is strongly involved in the maintenance of active wakefulness. PMID:24438489

  11. Properties of the stimulus router system, a novel neural prosthesis.

    PubMed

    Gan, Liu Shi; Prochazka, Arthur

    2010-02-01

    Various types of neural prostheses (NPs) have been developed to restore motor function after neural injury. Surface NPs are noninvasive and inexpensive, but are often poorly selective, activating nontargeted muscles and cutaneous sensory nerves that can cause discomfort or pain. Implantable NPs are highly selective, but invasive and costly. The stimulus router system (SRS) is a novel NP consisting of fully implanted leads that "capture" and route some of the current flowing between a pair of surface electrodes to the vicinity of a target nerve. An SRS lead consists of a "pick-up" terminal that is implanted subcutaneously under one of the surface electrodes and a "delivery" terminal that is secured on or near the target nerve. We have published a preliminary report on the basic properties of the SRS [L. S. Gan , "A new means of transcutaneous coupling for neural prostheses," IEEE Trans. Biomed. Eng., vol. 54, no. 3, pp. 509-517, Mar. 2007]. Here, we further characterize the SRS and identify aspects that maximize its performance as a motor NP. The surface current needed to activate nerves with an SRS, was found to depend on the proximity of the delivery terminal(s) to the nerve, electrode configurations, contact areas of the surface electrodes and implanted terminals, and the distance between the surface anode and the delivery terminal. PMID:19770087

  12. Optical properties of polymer microtips investigated with workshop tomographic system

    NASA Astrophysics Data System (ADS)

    Dudek, Michał; Kujawińska, Małgorzata; Makowski, Piotr; Jaroszewicz, Leszek R.; Parat, Vincent

    2016-04-01

    We present a novel methodology for optical fiber polymer microtip manufacturing ant testing, which supports the structure optimization process through utilization of an optical diffraction tomography system based on the lateral shear digital holographic microscope. The most important functional parameter of an optical fiber microtip is the output beam distribution in the far-field region, which depends on geometrical properties and refractive index distribution within the microtip. These factors, in turn, are determined by the optical power distribution of the actinic light and the exposition time during the photopolymerization process. In order to obtain a desired light field distribution we propose to govern the manufacturing process by a hybrid opto-numerical methodology, which constitutes a convenient feedback loop for modification of the fabrication parameters. A single cycle of the proposed scheme includes numerical modeling, tomographic measurements and modifications of fabrication process. We introduced the real values of three-dimensional refractive index distribution of microtips into the finite-difference time-domain (FDTD) simulations, which leaded to controlled modification of technology parameters and finally to improvement of a functional parameter of microtips.

  13. Properties of train traffic flow in a moving block system

    NASA Astrophysics Data System (ADS)

    Wang, Min; Zeng, Jun-Wei; Qian, Yong-Sheng; Li, Wen-Jun; Yang, Fang; Jia, Xin-Xin

    2012-07-01

    The development direction of railways is toward the improvement of capacity and service quality, where the service quality includes safety, schedule, high speed, and comfort. In light of the existing cellular automaton models, in this paper, we develop a model to analyze the mixed running processes of trains with maximal speeds of 500 km/h and 350 km/h respectively in the moving block system. In the proposed model, we establish some sound rules to control the running processes of a train, where the rules include the departure rules in the intermediate stations, the overtaking rules, and the conditions of speed limitation for a train stopping at a station or passing through a station. With the consideration of the mixed ratio and the distance between two adjacent stations, the properties of the train traffic flow (including capacity and average speed) are simulated. The numerical results show that the interactions among different trains will affect the capacity, and a proper increase of the spatial distance between two adjacent stations can enhance the capacity and the average speed under the moving block.

  14. Geothermal aquaculture project: Real Property Systems Inc. , Harney Basin, Oregon

    SciTech Connect

    Not Available

    1981-08-14

    Real Property Systems Inc., (RPS) owns two parcels in the vicinity of Harney Lake, Oregon. One parcel is 120 acres in size, the other is 200 acres. A study concludes that the 200 acre parcel has the greater potential for geothermal development. RPS is interested in an aquaculture operation that produces fresh water prawns, (Macrobrachium rosenbergii) for the market. To supply the heat necessary to maintain the ideal temperature of 82/sup 0/F desired for these prawns, a geothermal resource having a 150/sup 0/F temperature or higher, is needed. The best estimate is that 150/sup 0/F water can be found from a minimum 1090 feet depth to 2625 feet, with no absolute assurances that sufficient quantities of geothermal waters exist without drilling for the same. This study undertakes the preliminary determination of project economics so that a decision can be made whether or not to proceed with exploratory drilling. The study is based on 10 acres of ponds, with a peak requirement of 2500 gpm of 150/sup 0/F geothermal water.

  15. Levitation properties of maglev systems using soft ferromagnets

    NASA Astrophysics Data System (ADS)

    Huang, Chen-Guang; Zhou, You-He

    2015-03-01

    Soft ferromagnets are widely used as flux-concentration materials in the design of guideways for superconducting magnetic levitation transport systems. In order to fully understand the influence of soft ferromagnets on the levitation performance, in this work we apply a numerical model based on the functional minimization method and the Bean’s critical state model to study the levitation properties of an infinitely long superconductor immersed in the magnetic field created by a guideway of different sets of infinitely long parallel permanent magnets with soft ferromagnets between them. The levitation force, guidance force, magnetic stiffness and magnetic pole density are calculated considering the coupling between the superconductor and soft ferromagnets. The results show that the levitation performance is closely associated with the permanent magnet configuration and with the location and dimension of the soft ferromagnets. Introducing the soft ferromagnet with a certain width in a few configurations always decreases the levitation force. However, for most configurations, the soft ferromagnets contribute to improve the levitation performance only when they have particular locations and dimensions in which the optimized location and thickness exist to increase the levitation force the most. Moreover, if the superconductor is laterally disturbed, the presence of soft ferromagnets can effectively improve the lateral stability for small lateral displacement and reduce the degradation of levitation force.

  16. Texture and magnetic properties of exchange bias systems

    NASA Astrophysics Data System (ADS)

    Aley, N. P.; Bowes, M.; Kröger, R.; O'Grady, K.

    2010-05-01

    We report on the magnetic and structural properties of IrMn/CoFe exchange bias systems deposited onto a dual seed layer of NiCr(X)/Ru(5 nm), with X=2, 6, and 20 nm. Samples with the structure NiCr (Xnm)/IrMn (7 nm)/CoFe (3 nm)/Ta (10 nm) with X=2, 6, and 20 nm were prepared by dc sputtering for magnetic characterization. A second set of samples with structure NiCr (Xnm)/IrMn (10 nm) with X=2, 6, and 20 nm were deposited onto TEM grids for structural characterization by TEM. A method of manipulating of the TEM grid to allow a qualitative analysis of the in-plane texture of the samples is described and used to analyze the microstructure of these samples. The microstructure and particularly the texture are correlated with the anisotropy constant (KAF) of the antiferromagnet (AF) layer, with an optimum NiCr seed layer of 6 nm to give a maximum value of KAF of 1.2×107 ergs/cc.

  17. Dust in the Solar System - Properties and Origins

    NASA Technical Reports Server (NTRS)

    Messenger, Scott; Keller, Lindsay; Nakamura-Messenger, Keiko

    2013-01-01

    include both amorphous and crystalline silicates. The organic matter in these samples also exhibits highly anomalous H, C, and N isotopic compositions that are consistent with formation in low temperature environments at the outermost regions of the solar nebula or presolar cold molecular cloud. The scientific frontiers for these samples include working toward a better understanding of the origins of the solar system amorphous and crystalline grains in IDPs and the very challenging task of determining the chemical composition of sub-micron organic grains. Laboratory studies of ancient and present-day dust in the Solar System thus reveal in exquisite detail the chemistry, mineralogy and isotopic properties of materials that derive from a range of astrophysical environments. These studies are an important complement to astronomical observations that help to place the laboratory observations into broader context.

  18. 25 CFR 900.54 - Should the property management system prescribe internal controls?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Should the property management system prescribe internal... System Standards § 900.54 Should the property management system prescribe internal controls? Yes. Effective internal controls should include procedures: (a) For the conduct of periodic inventories; (b)...

  19. Organic cotton systems improved soil properties vis-a-vis the modern systems

    NASA Astrophysics Data System (ADS)

    Blaise, D.; Venugopalan, M. V.; Singh, J. V.; Narkhedkar, N. G.; Velmourougane, K.

    2012-04-01

    India is the largest cotton growing country in the world. Traditionally, cotton in India was grown with minimal inputs and resources available on farm were put to efficient use. Advent of hybrids and Bt cotton revolutionized cotton production in the country and lead to heavy reliance on external inputs. However, there is a growing awareness of the detrimental effects of excessive use of pesticides and fertilizers. This is leading to growing interest in organic cultivation of crops. An organic system (OS) was compared with the modern systems (MS) for changes in the soil physical, chemical and biological properties in field experiments conducted both on station and farmers fields in Maharashtra, India on rain dependent cotton grown on Vertisols. Soil samples of the organic plots had significantly greater C content than the MS plots relying on mineral fertilizers and pesticides. Similarly, other nutrients were also greater in the OS than the MS across locations. Most of the increases were noticed in the top 30 cm of the soil profile. Interestingly, enrichment of the soil at lower depths was noticed in the OS which could be due to the surface creep of soils through the cracks in the Vertisols. With regard to the physical properties, water-stable aggregates and mean weight diameter in the MS were significantly lesser than the OS. Differences were restricted to the top 20 cm. Soil biological properties of the two systems were compared through the enzyme assays such as the dehydrogenase, glucosidase, phosphatase, sulfatase periodically during the crop growing season. All the enzyme assays indicated greater activities in the OS than the MS. Further, microfauna (nematodes) monitored indicated less of plant parasitic nematodes in the OS than the MS. Excessive tillage followed in the MS did bring about a reduction in the nematode numbers. But the systems had more parasitic nematodes.

  20. 25 CFR 900.51 - What is an Indian tribe or tribal organization's property management system expected to do?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Systems Property Management System Standards § 900.51 What is an Indian tribe or tribal organization's property management system expected to do? An Indian tribe or tribal organization's property management...-determination contract or acquired with contract funds. The property management system shall...

  1. 25 CFR 900.51 - What is an Indian tribe or tribal organization's property management system expected to do?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Systems Property Management System Standards § 900.51 What is an Indian tribe or tribal organization's property management system expected to do? An Indian tribe or tribal organization's property management...-determination contract or acquired with contract funds. The property management system shall...

  2. 25 CFR 900.51 - What is an Indian tribe or tribal organization's property management system expected to do?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Systems Property Management System Standards § 900.51 What is an Indian tribe or tribal organization's property management system expected to do? An Indian tribe or tribal organization's property management...-determination contract or acquired with contract funds. The property management system shall...

  3. 25 CFR 900.51 - What is an Indian tribe or tribal organization's property management system expected to do?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Systems Property Management System Standards § 900.51 What is an Indian tribe or tribal organization's property management system expected to do? An Indian tribe or tribal organization's property management...-determination contract or acquired with contract funds. The property management system shall...

  4. Users guide for the shuttle mass properties automated system

    NASA Technical Reports Server (NTRS)

    Hamil, R. G.

    1975-01-01

    A set of programs developed for use on the JSC Univac 1100 series computers and designed to automate the collection and processing of data into the mass properties section of the shuttle operational data book is described.

  5. Property.

    ERIC Educational Resources Information Center

    Goldblatt, Steven M.

    In this chapter on decisions made by federal and state courts during 1983 concerning school property it is noted that no new trends emerged during the year. Among the topics addressed are the extent of school board authority over property use and other property matters; the attachment and detachment of land from school district holdings; school…

  6. Property.

    ERIC Educational Resources Information Center

    Piele, Philip K.

    Several court cases involving acquisition, use, and disposal of property by institutions of higher education are briefly summarized in this chapter. Cases discussed touch on such topics as municipal annexation of university property; repurchase of properties temporarily allocated to faculty members; implications of zoning laws and zoning board…

  7. ORBITAL DEPENDENCE OF GALAXY PROPERTIES IN SATELLITE SYSTEMS OF GALAXIES

    SciTech Connect

    Hwang, Ho Seong; Park, Changbom E-mail: cbp@kias.re.k

    2010-09-01

    We study the dependence of satellite galaxy properties on the distance to the host galaxy and the orbital motion (prograde and retrograde orbits) using the Sloan Digital Sky Survey (SDSS) data. From SDSS Data Release 7, we find 3515 isolated satellite systems of galaxies at z < 0.03 that contain 8904 satellite galaxies. Using this sample, we construct a catalog of 635 satellites associated with 215 host galaxies whose spin directions are determined by our inspection of the SDSS color images and/or by spectroscopic observations in the literature. We divide satellite galaxies into prograde and retrograde orbit subsamples depending on their orbital motion with respect to the spin direction of the host. We find that the number of galaxies in prograde orbit is nearly equal to that of retrograde orbit galaxies: the fraction of satellites in prograde orbit is 50% {+-} 2%. The velocity distribution of satellites with respect to their hosts is found to be almost symmetric: the median bulk rotation of satellites is -1 {+-} 8 km s{sup -1}. It is found that the radial distribution of early-type satellites in prograde orbit is strongly concentrated toward the host while that of retrograde ones shows much less concentration. We also find the orbital speed of late-type satellites in prograde orbit increases as the projected distance to the host (R) decreases while the speed decreases for those in retrograde orbit. At R less than 0.1 times the host virial radius (R < 0.1r{sub vir,host}), the orbital speed decreases in both prograde and retrograde orbit cases. Prograde satellites are on average fainter than retrograde satellites for both early and late morphological types. The u - r color becomes redder as R decreases for both prograde and retrograde orbit late-type satellites. The differences between prograde and retrograde orbit satellite galaxies may be attributed to their different origin or the different strength of physical processes that they have experienced through

  8. Discrepancies between Ideal Characteristics of a Property Tax System and Current Practice in New York.

    ERIC Educational Resources Information Center

    Netzer, Dick; Berne, Robert

    1995-01-01

    Ideally, voters' and state legislatures' policy choices should underlie a property tax system that is straightforward, comprehensible, systematic, and reasonably related to policy objectives. Administration should be uniform and fair. New York State's property tax system lacks a uniform valuation standard and "circuit breaker" and has deficiencies…

  9. Mechanical and wear properties of PMMA/PVDF microfilled systems

    SciTech Connect

    Garcia, J.L.; Koelling, K.W.; Seghi, R.R.

    1996-12-31

    There is a clinical need in fixed prosthodontics for aesthetic materials that are biologically compatible. Polymethylmethacrylate (PMMA) has been used extensively in dental applications. Blends of PMMA and polyvinylidene fluoride (PVDF) are a new class of materials that might perform as aesthetic restorative materials. The fracture properties of PMMA have been intensively studied because it is an amorphous glass below 110{degrees}C, thus exhibiting brittle fracture under normal testing conditions below about 85{degrees}C. However, this brittle behavior leads to poor wear resistance. The properties of the matrix can be tailored by blending with PVDF. The blends are composed of homogeneous mixtures of the two polymers at the molecular level. Polyvinylidene fluoride molecules do not contribute to the mechanical yield behavior of the blend but do act as plasticizers. Improvements in the mechanical properties may be achieved by incorporating a filler into the polymer matrix.

  10. Mixed 2D molecular systems: Mechanic, thermodynamic and dielectric properties

    NASA Astrophysics Data System (ADS)

    Beňo, Juraj; Weis, Martin; Dobročka, Edmund; Haško, Daniel

    2008-08-01

    Study of Langmuir monolayers consisting of stearic acid (SA) and dipalmitoylphosphatidylcholine (DPPC) molecules was done by surface pressure-area isotherms ( π- A), the Maxwell displacement current (MDC) measurement, X-ray reflectivity (XRR) and atomic force microscopy (AFM) to investigate the selected mechanic, thermodynamic and dielectric properties based on orientational structure of monolayers. On the base of π- A isotherms analysis we explain the creation of stable structures and found optimal monolayer composition. The dielectric properties represented by MDC generated monolayers were analyzed in terms of excess dipole moment, proposing the effect of dipole-dipole interaction. XRR and AFM results illustrate deposited film structure and molecular ordering.

  11. Structure-Property Characterization of the Crinkle-Leaf Peach Wood Phenotype: A Future Model System for Wood Properties Research?

    NASA Astrophysics Data System (ADS)

    Wiedenhoeft, Alex C.; Arévalo, Rafael; Ledbetter, Craig; Jakes, Joseph E.

    2016-08-01

    Nearly 400 million years of evolution and field-testing by the natural world has given humans thousands of wood types, each with unique structure-property relationships to study, exploit, and ideally, to manipulate, but the slow growth of trees makes them a recalcitrant experimental system. Variations in wood features of two genotypes of peach (Prunus persica L.) trees, wild-type and crinkle-leaf, were examined to elucidate the nature of weak wood in crinkle-leaf trees. Crinkle-leaf is a naturally-occurring mutation in which wood strength is altered in conjunction with an easily observed `crinkling' of the leaves' surface. Trees from three vigor classes (low growth rate, average growth rate, and high growth rate) of each genotype were sampled. No meaningful tendency of dissimilarities among the different vigor classes was found, nor any pattern in features in a genotype-by-vigor analysis. Wild-type trees exhibited longer vessels and fibers, wider rays, and slightly higher specific gravity. Neither cell wall mechanical properties measured with nanoindentation nor cell wall histochemical properties were statistically or observably different between crinkle-leaf and wild-type wood. The crinkle-leaf mutant has the potential to be a useful model system for wood properties investigation and manipulation if it can serve as a field-observable vegetative marker for altered wood properties.

  12. Property.

    ERIC Educational Resources Information Center

    Piele, Philip K.; Johnson, Margaret M.

    This chapter deals with 1981 cases involving disputes over property. Cases involving the detachment and attachment of land continue to dominate the property chapter with 11 cases reported, the same number summarized in last year's chapter. One case involving school board referenda raised the interesting question of whether or not a state could…

  13. Property.

    ERIC Educational Resources Information Center

    Bickel, Robert D.; Zeller, Trisha A.

    A number of cases related to property issues involving institutions of higher education are examined in this chapter. Cases discussed touch on such topics as funding for property and equipment acquisition; opposition to building construction or demolition; zoning issues; building construction and equipment contracts; and lease agreements. Current…

  14. Property.

    ERIC Educational Resources Information Center

    Goldblatt, Steven M.; Piele, Philip K.

    This chapter reviews 1982 cases related to school property. Cases involving citizen efforts to overturn school board decisions to close schools dominate the property chapter, and courts continue to uphold school board authority to close schools, transfer students, and sell or lease the buildings. Ten cases involving detachment and attachment of…

  15. Property.

    ERIC Educational Resources Information Center

    Piele, Philip K.

    Chapter 7 of a book on school law, this chapter deals with 1979 cases involving disputes over property. Cases involving taxpayer attempts to prevent the construction of school buildings dominate this year's property chapter, as they did last year's. Yet, paradoxically, there is also a significant increase in cases in which taxpayers tried to…

  16. Computer modeling of properties of complex molecular systems

    SciTech Connect

    Kulkova, E.Yu.; Khrenova, M.G.; Polyakov, I.V.

    2015-03-10

    Large molecular aggregates present important examples of strongly nonhomogeneous systems. We apply combined quantum mechanics / molecular mechanics approaches that assume treatment of a part of the system by quantum-based methods and the rest of the system with conventional force fields. Herein we illustrate these computational approaches by two different examples: (1) large-scale molecular systems mimicking natural photosynthetic centers, and (2) components of prospective solar cells containing titan dioxide and organic dye molecules. We demonstrate that modern computational tools are capable to predict structures and spectra of such complex molecular aggregates.

  17. Common computational properties found in natural sensory systems

    NASA Astrophysics Data System (ADS)

    Brooks, Geoffrey

    2009-05-01

    Throughout the animal kingdom there are many existing sensory systems with capabilities desired by the human designers of new sensory and computational systems. There are a few basic design principles constantly observed among these natural mechano-, chemo-, and photo-sensory systems, principles that have been proven by the test of time. Such principles include non-uniform sampling and processing, topological computing, contrast enhancement by localized signal inhibition, graded localized signal processing, spiked signal transmission, and coarse coding, which is the computational transformation of raw data using broadly overlapping filters. These principles are outlined here with references to natural biological sensory systems as well as successful biomimetic sensory systems exploiting these natural design concepts.

  18. Thermodynamic properties of some metal oxide-zirconia systems

    NASA Technical Reports Server (NTRS)

    Jacobson, Nathan S.

    1989-01-01

    Metal oxide-zirconia systems are a potential class of materials for use as structural materials at temperatures above 1900 K. These materials must have no destructive phase changes and low vapor pressures. Both alkaline earth oxide (MgO, CaO, SrO, and BaO)-zirconia and some rare earth oxide (Y2O3, Sc2O3, La2O3, CeO2, Sm2O3, Gd2O3, Yb2O3, Dy2O3, Ho2O3, and Er2O3)-zirconia system are examined. For each system, the phase diagram is discussed and the vapor pressure for each vapor species is calculated via a free energy minimization procedure. The available thermodynamic literature on each system is also surveyed. Some of the systems look promising for high temperature structural materials.

  19. System and method to determine thermophysical properties of a multi-component gas

    DOEpatents

    Morrow, Thomas B.; Behring, II, Kendricks A.

    2003-08-05

    A system and method to characterize natural gas hydrocarbons using a single inferential property, such as standard sound speed, when the concentrations of the diluent gases (e.g., carbon dioxide and nitrogen) are known. The system to determine a thermophysical property of a gas having a first plurality of components comprises a sound velocity measurement device, a concentration measurement device, and a processor to determine a thermophysical property as a function of a correlation between the thermophysical property, the speed of sound, and the concentration measurements, wherein the number of concentration measurements is less than the number of components in the gas. The method includes the steps of determining the speed of sound in the gas, determining a plurality of gas component concentrations in the gas, and determining the thermophysical property as a function of a correlation between the thermophysical property, the speed of sound, and the plurality of concentrations.

  20. Advanced fuel system technology for utilizing broadened property aircraft fuels

    NASA Technical Reports Server (NTRS)

    Reck, G. M.

    1980-01-01

    Factors which will determine the future supply and cost of aviation turbine fuels are discussed. The most significant fuel properties of volatility, fluidity, composition, and thermal stability are discussed along with the boiling ranges of gasoline, naphtha jet fuels, kerosene, and diesel oil. Tests were made to simulate the low temperature of an aircraft fuel tank to determine fuel tank temperatures for a 9100-km flight with and without fuel heating; the effect of N content in oil-shale derived fuels on the Jet Fuel Thermal Oxidation Tester breakpoint temperature was measured. Finally, compatibility of non-metallic gaskets, sealants, and coatings with increased aromatic content jet fuels was examined.

  1. Electrokinetic Properties of Lubricin Antiadhesive Coatings in Microfluidic Systems.

    PubMed

    Greene, George W; Duffy, Emer; Shallan, Aliaa; Wuethrich, Alain; Paull, Brett

    2016-02-23

    Lubricin is a glycoprotein found in articular joints which has long been recognized as being an important biological boundary lubricant molecule and, more recently, an impressive antiadhesive that readily self-assembles into a well ordered, polymer brush layer on virtually any substrate. The lubricin molecule possesses an overabundance of anionic charge, a property that is atypical among antiadhesive molecules, that enables its use as a coating for applications involving electrokinetic processes such as electrophoresis and electroosmosis. Coating the surfaces of silica and polymeric microfluidic devices with self-assembled lubricin coatings affords a unique combination of excellent fouling resistance and high charge density that enables notoriously "sticky" biomolecules such as proteins to be used and controlled electrokinetically in the device without complications arising from nonspecific adsorption. Using capillary electrophoresis, we characterized the stability, uniformity, and electrokinetic properties of lubricin coatings applied to silica and PTFE capillaries over a range of run buffer pHs and when exposed to concentrated solutions of protein. In addition, we demonstrate the effectiveness of lubricin as a coating to minimize nonspecific protein adsorption in an electrokinetically controlled polydimethylsiloxane/silica microfluidic device. PMID:26814794

  2. Flight control systems properties and problems, volume 1

    NASA Technical Reports Server (NTRS)

    Mcruer, D. T.; Johnston, D. E.

    1975-01-01

    This volume contains a delineation of fundamental and mechanization-specific flight control characteristics and problems gleaned from many sources and spanning a period of over two decades. It is organized to present and discuss first some fundamental, generic problems of closed-loop flight control systems involving numerator characteristics (quadratic dipoles, non-minimum phase roots, and intentionally introduced zeros). Next the principal elements of the largely mechanical primary flight control system are reviewed with particular emphasis on the influence of nonlinearities. The characteristics and problems of augmentation (damping, stability, and feel) system mechanizations are then dealt with. The particular idiosyncracies of automatic control actuation and command augmentation schemes are stressed, because they constitute the major interfaces with the primary flight control system and an often highly variable vehicle response.

  3. Low temperature thermal properties of composite insulation systems

    NASA Astrophysics Data System (ADS)

    Fabian, P. E.; Bauer-McDaniel, T. S.; Reed, R. P.

    The thermal contraction and thermal conductivity of candidate composite insulation systems for the International Thermonuclear Experimental Reactor toroidal field coils were measured from 295 to 4 K. Matrix materials consisted of a diglycidyl ether of bisphenol-A epoxy suitable for vacuum impregnation, a tetrafunctional epoxy suitable for pre-impregnation, a polyimide system produced by a high-pressure laminating process, and a bismaleimide system. These matrix materials were combined with S-2 glass fabric and various barrier systems, such as ceramic and organic coatings, polyimide film and mica/glass. Thermal contraction was measured by the strain gauge method in which strain gauges are attached directly to the specimen. The thermal contraction in the through-thickness direction was different at 4 K for each resin system and changed slightly with the addition of electrical barriers. The thermal conductivity of the materials, with and without the electrical barriers, was similar at 4 K, but more distinctive at higher temperatures. The systems with the ceramic coatings exhibited the highest thermal conductivities at all temperatures.

  4. Property Accounting for Local and State School Systems. State Educational Records and Reports Series--Handbook III.

    ERIC Educational Resources Information Center

    Reason, Paul L.; Tankard, George G., Jr.

    This handbook serves as a basic guide to property accounting for local and state school systems in the U.S. Information and guidelines are presented regarding--(1) classification of property accounts, (2) definitions of property accounts, (3) measures of school property, (4) supplies and equipment, (5) individual property records, and (6) summary…

  5. Impacts of an integrated crop-livestock system on soil properties to enhance precipitation capture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cropping/Livestock systems alter soil properties that are important in enhancing capture of precipitation by developing and maintaining water infiltration and storage. In this paper we will relate soil hydraulic conductivity and other physical properties on managed Old World Bluestem grassland, whea...

  6. A Variational Property of the Velocity Distribution in a System of Material Particles

    ERIC Educational Resources Information Center

    Siboni, S.

    2009-01-01

    A simple variational property concerning the velocity distribution of a set of point particles is illustrated. This property provides a full characterization of the velocity distribution which minimizes the kinetic energy of the system for prescribed values of linear and angular momentum. Such a characterization is applied to discuss the kinetic…

  7. 41 CFR 109-1.5204 - Review and approval of a designated contractor's personal property management system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false Review and approval of a designated contractor's personal property management system. 109-1.5204 Section 109-1.5204 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT...

  8. 41 CFR 109-1.5204 - Review and approval of a designated contractor's personal property management system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false Review and approval of a designated contractor's personal property management system. 109-1.5204 Section 109-1.5204 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT...

  9. 41 CFR 109-1.5204 - Review and approval of a designated contractor's personal property management system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false Review and approval of a designated contractor's personal property management system. 109-1.5204 Section 109-1.5204 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT...

  10. Propagation properties of Bessel and Bessel-Gaussian beams in a fractional Fourier transform optical system

    NASA Astrophysics Data System (ADS)

    Zhao, Chengliang; Huang, Kaikai; Lu, Xuanhui

    2010-03-01

    The properties of Bessel-Gaussian beams (BGBs) and Bessel beams (BBs) propagating through a fractional Fourier transform (FRT) optical system have been investigated. The analytical transformation formulae for BBs and BGBs propagation through a FRT optical system are derived based on definition of the FRT in the cylindrical coordinate system. By using the derived formula, numerical examples are illustrated.

  11. Markov property and strong additivity of von Neumann entropy for graded quantum systems

    SciTech Connect

    Moriya, Hajime

    2006-03-15

    The quantum Markov property is equivalent to the strong additivity of von Neumann entropy for graded quantum systems. The additivity of von Neumann entropy for bipartite graded systems implies the statistical independence of states. However, the structure of Markov states for graded systems is different from that for tensor-product systems which have trivial grading. For three-composed graded systems we have U(1)-gauge invariant Markov states whose restriction to the marginal pair of subsystems is nonseparable.

  12. Thermal properties of composite materials: a complex systems approximation

    NASA Astrophysics Data System (ADS)

    Carrillo, J. L.; Bonilla, Beatriz; Reyes, J. J.; Dossetti, Victor

    We propose an effective media approximation to describe the thermal diffusivity of composite samples made of polyester resin and magnetite inclusions. By means of photoacoustic spectroscopy, the thermal diffusivity of the samples were experimentally measured. The volume fraction of the inclusions was systematically varied in order to study the changes in the effective thermal diffusivity of the composites. For some samples, a static magnetic field was applied during the polymerization process, resulting in anisotropic inclusion distributions. Our results show a significant difference in the thermal properties of the anisotropic samples, compared to the isotropic randomly distributed. We correlate some measures of the complexity of the inclusion structure with the observed thermal response through a multifractal analysis. In this way, we are able to describe, and at some extent predict, the behavior of the thermal diffusivity in terms of the lacunarity and other measures of the complexity of these samples Partial Financial Support by CONACyT México and VIEP-BUAP.

  13. Adaptive mechanical properties of topologically interlocking material systems

    NASA Astrophysics Data System (ADS)

    Khandelwal, S.; Siegmund, T.; Cipra, R. J.; Bolton, J. S.

    2015-04-01

    Topologically interlocked material systems are two-dimensional granular crystals created as ordered and adhesion-less assemblies of unit elements of the shape of platonic solids. The assembly resists transverse forces due to the interlocking geometric arrangement of the unit elements. Topologically interlocked material systems yet require an external constraint to provide resistance under the action of external load. Past work considered fixed and passive constraints only. The objective of the present study is to consider active and adaptive external constraints with the goal to achieve variable stiffness and energy absorption characteristics of the topologically interlocked material system through an active control of the in-plane constraint conditions. Experiments and corresponding model analysis are used to demonstrate control of system stiffness over a wide range, including negative stiffness, and energy absorption characteristics. The adaptive characteristics of the topologically interlocked material system are shown to solve conflicting requirements of simultaneously providing energy absorption while keeping loads controlled. Potential applications can be envisioned in smart structure enhanced response characteristics as desired in shock absorption, protective packaging and catching mechanisms.

  14. Asymmetric effects on the optical properties of double-quantum well systems

    NASA Astrophysics Data System (ADS)

    Silotia, Poonam; Batra, Kriti; Prasad, Vinod

    2014-02-01

    Linear, nonlinear, and total absorption coefficient and refractive index changes of double-quantum well (DQW) systems are studied theoretically in the presence of external static electric field applied along the growth direction. The analytical expression for the linear and nonlinear optical properties is obtained using density matrix method. Emphasis is laid on the effect of asymmetry in the shapes of DQW system on optical properties. Some interesting results are obtained and explained.

  15. System and methods to determine and monitor changes in microstructural properties

    DOEpatents

    Turner, Joseph A

    2014-11-18

    A system and methods with which changes in microstructure properties such as grain size, grain elongation, texture, and porosity of materials can be determined and monitored over time to assess conditions such as stress and defects. An example system includes a number of ultrasonic transducers configured to transmit ultrasonic waves towards a target region on a specimen, a voltage source configured to excite the first and second ultrasonic transducers, and a processor configured to determine one or more properties of the specimen.

  16. Broiler litter fertilization and cropping system impacts on soil properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A 3-year study was conducted at the Mississippi Agricultural and Forestry Experiment Station, Verona, MS, in a Catalpa silty clay loam soil (Fine, smectitic, thermic Fluvaquentic Hapludolls) to evaluate soil chemical, physical, and biological changes resulting from cropping systems along with broile...

  17. An ultrasonic system for determining papaya physiological properties

    NASA Astrophysics Data System (ADS)

    Ibrahim, Sallehuddin; Ramli, Azlin; Yunus, Mohd Amri Md

    2015-05-01

    There is an increasing need for high quality fruit. As such it is important to have a fast, accurate and reliable method for measuring and monitoring the quality of fruit from the field to the consumer. This paper presents an investigation on the use of a non-destructive ultrasonic system which can be used to measure the quality of papaya.

  18. Intriguing emission properties of triphenylamine-carborane systems.

    PubMed

    Kim, So-Yoen; Cho, Yang-Jin; Jin, Guo Fan; Han, Won-Sik; Son, Ho-Jin; Cho, Dae Won; Kang, Sang Ook

    2015-06-28

    Electron donor-acceptor (D-A) systems with a triphenylamino moiety (D) and ortho-carborane (A) show three kinds of intriguing emissions that can be attributed to the local excited state, the intramolecular charge-transfer state, and the aggregation-induced emission state. The emission behaviors depend on which positions of the carborane are substituted. PMID:26013604

  19. Metallurgical and tensile property analysis of several silicon carbide/titanium composite systems

    NASA Technical Reports Server (NTRS)

    Brewer, W. D.; Unnam, J.

    1983-01-01

    Several silicon-carbide fiber reinforced titanium matrix composite systems were investigated to determine composite degradation mechanisms and to develop techniques to minimize loss of mechanical properties during fabrication and in service. Emphasis was on interface control by fiber or matrix coatings. Fibers and matrix materials were sputter coated with various metals to determine the effects of the coatings on basic fiber properties, fiber-matrix interactions, and on composite properties. The effects of limited variations in fabrication temperature on composite properties were determined for composites consolidated by standard press-diffusion-bonding techniques.

  20. Coal properties and system operating parameters for underground coal gasification

    SciTech Connect

    Yang, L.

    2008-07-01

    Through the model experiment for underground coal gasification, the influence of the properties for gasification agent and gasification methods on underground coal gasifier performance were studied. The results showed that pulsating gasification, to some extent, could improve gas quality, whereas steam gasification led to the production of high heating value gas. Oxygen-enriched air and backflow gasification failed to improve the quality of the outlet gas remarkably, but they could heighten the temperature of the gasifier quickly. According to the experiment data, the longitudinal average gasification rate along the direction of the channel in the gasifying seams was 1.212 m/d, with transverse average gasification rate 0.069 m/d. Experiment indicated that, for the oxygen-enriched steam gasification, when the steam/oxygen ratio was 2:1, gas compositions remained stable, with H{sub 2} + CO content virtually standing between 60% and 70% and O{sub 2} content below 0.5%. The general regularities of the development of the temperature field within the underground gasifier and the reasons for the changes of gas quality were also analyzed. The 'autopneumatolysis' and methanization reaction existing in the underground gasification process were first proposed.

  1. Biogeochemical properties of eddies in the California Current System

    NASA Astrophysics Data System (ADS)

    Chenillat, Fanny; Franks, Peter J. S.; Combes, Vincent

    2016-06-01

    The California Current System (CCS) has intense mesoscale activity that modulates and exports biological production from the coastal upwelling system. To characterize and quantify the ability of mesoscale eddies to affect the local and regional planktonic ecosystem of the CCS, we analyzed a 10 year-long physical-biological model simulation, using eddy detection and tracking to isolate the dynamics of cyclonic and anticyclonic eddies. As they propagate westward across the shelf, cyclonic eddies efficiently transport coastal planktonic organisms and maintain locally elevated production for up to 1 year (800 km offshore). Anticyclonic eddies, on the other hand, have a limited impact on local production over their ~6 month lifetime as they propagate 400 km offshore. At any given time ~8% of the model domain was covered by eddy cores. Though the eddies cover a small area, they explain ~50 and 20% of the transport of nitrate and plankton, respectively.

  2. Evaluation of the electromechanical properties of the cardiovascular system

    NASA Technical Reports Server (NTRS)

    Bergman, S. A., Jr.; Hoffler, G. W.; Johnson, R. L.

    1974-01-01

    Cardiovascular electromechanical measurements were collected on returning Skylab crewmembers at rest and during both lower body negative pressure and exercise stress testing. These data were compared with averaged responses from multiple preflight tests. Systolic time intervals and first heart sound amplitude changes were measured. Clinical cardiovascular examinations and clinical phonocardiograms were evaluated. All changes noted returned to normal within 30 days postflight so that the processes appear to be transient and self limited. The cardiovascular system seems to adapt quite readily to zero-g, and more importantly it is capable of readaptation to one-g after long duration space flight. Repeated exposures to zero-g also appear to have no detrimental effects on the cardiovascular system.

  3. Property.

    ERIC Educational Resources Information Center

    Piele, Philip K.

    Reflecting widespread unhappiness with the growing tax burdens in this country, the most active area of litigation reported in the property chapter this year involves various attempts by taxpayers to prevent the construction or remodeling of public school facilities. While some taxpayers fought to keep schools from being built, others in New York…

  4. Structural Properties and Estimation of Delay Systems. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Kwong, R. H. S.

    1975-01-01

    Two areas in the theory of delay systems were studied: structural properties and their applications to feedback control, and optimal linear and nonlinear estimation. The concepts of controllability, stabilizability, observability, and detectability were investigated. The property of pointwise degeneracy of linear time-invariant delay systems is considered. Necessary and sufficient conditions for three dimensional linear systems to be made pointwise degenerate by delay feedback were obtained, while sufficient conditions for this to be possible are given for higher dimensional linear systems. These results were applied to obtain solvability conditions for the minimum time output zeroing control problem by delay feedback. A representation theorem is given for conditional moment functionals of general nonlinear stochastic delay systems, and stochastic differential equations are derived for conditional moment functionals satisfying certain smoothness properties.

  5. Measurement system and precision analysis for bending and twisting properties evaluation of textile fabrics

    NASA Astrophysics Data System (ADS)

    Yao, Bao-guo; Zhang, Shan; Yang, Yun-juan; Zhang, De-pin

    2016-01-01

    A new test method and a measurement system was proposed and developed to evaluate the bending and twisting properties of textile fabrics. The measurement system and the test method is based on the mechanical device, sensors and microelectronics and simulates the dynamic process during the fabric is bent and twisted. The virtual instrument based system can measure the dynamic changes of the signals due to the bending and twisting loads. Derived from the test data, a series of indices are defined to characterize the bending and twisting properties. The test and evaluation method, the experiments and the test results are reported. The analysis of the variance for intra-laboratory test was performed to determine the precisions of the test method and the measurement system. The measurement system provides a method for objective measurement and evaluation of bending and twisting properties of textile fabrics.

  6. Fluency Profiling System: an automated system for analyzing the temporal properties of speech.

    PubMed

    Little, Daniel R; Oehmen, Raoul; Dunn, John; Hird, Kathryn; Kirsner, Kim

    2013-03-01

    The temporal characteristics of speech can be captured by examining the distributions of the durations of measurable speech components, namely speech segment durations and pause durations. However, several barriers prevent the easy analysis of pause durations: The first problem is that natural speech is noisy, and although recording contrived speech minimizes this problem, it also discards diagnostic information about cognitive processes inherent in the longer pauses associated with natural speech. The second issue concerns setting the distribution threshold, and consists of the problem of appropriately classifying pause segments as either short pauses reflecting articulation or long pauses reflecting cognitive processing, while minimizing the overall classification error rate. This article describes a fully automated system for determining the locations of speech-pause transitions and estimating the temporal parameters of both speech and pause distributions in natural speech. We use the properties of Gaussian mixture models at several stages of the analysis, in order to identify theoretical components of the data distributions, to classify speech components, to compute durations, and to calculate the relevant statistics. PMID:22718287

  7. Double-integrating-sphere system for measuring the optical properties of tissue.

    PubMed

    Pickering, J W; Prahl, S A; van Wieringen, N; Beek, J F; Sterenborg, H J; van Gemert, M J

    1993-02-01

    A system is described and evaluated for the simultaneous measurement of the intrinsic optical properties of tissue: the scattering coefficient, the absorption coefficient, and the anisotropy factor. This system synthesizes the theory of two integrating spheres and an intervening scattering sample with the inverse adding-doubling algorithm, which employs the adding-doubling solution of the radiative transfer equation to determine the optical properties from the measurement of the light flux within each sphere and of the unscattered transmission. The optical properties may be determined simultaneously, which allows for measurements to be made while the sample undergoes heating, chemical change, or some otherexternal stimulus. An experimental validation of the system with tissue phantoms resulted in the determination of the optical properties with a < 5% deviation when the optical density was between 1 and 10 and the albedo was between 0.4 and 0.95. PMID:20802704

  8. Site-specific analysis of dielectric properties of finite systems.

    SciTech Connect

    Jackson, K.; Yang, M.; Jellinek, J.; Chemistry; Central Michigan Univ.

    2007-12-06

    A new scheme for decomposing the total dipole moment and polarizability of a system into site-specific contributions is presented. The scheme is based on partitioning the system volume into cells associated with its atoms or groups of atoms. The site-specific dipole moments and polarizabilities are computed from the charge densities within the individual cells and the responses of these densities to an external electric field. These dipole moments and polarizabilities are further partitioned into local/dipole and charge-transfer components. The utility of the scheme is illustrated through analysis of the structure-/shape- and size-specific aspects of the dipole moments and polarizabilities of silicon clusters. It is shown that the polarizabilities associated with the individual constituent Si atoms vary considerably with the structure/shape of the cluster and the location of the atom or site within a given structure. Surface atoms, and especially those at edges, have larger polarizabilities than interior atoms. The overall contribution of the charge-transfer components to the total cluster polarizability increases with the cluster size. Finally, the anisotropy of the total polarizability correlates with the anisotropy of the cluster shape, and the charge-transfer component is the part dominantly responsible for the polarizability anisotropy.

  9. Health as a property of engineered living systems.

    PubMed

    Holm, Sune

    2013-10-01

    This article considers naturalistic analyses of the concepts of health and disease in light of the possibility of constructing novel living systems. The article begins by introducing the vision of synthetic biology as the application of engineering principles to the construction of biological systems, the main analyses of the concepts of health and disease, and the standard theories of function in artefacts and organisms. The article then suggests that reflection on the possibility of artefactual organisms amounts to a challenge to the functional theories of health and disease proposed by Wakefield and Boorse. More specifically, Wakefield and Boorse's theories are reconstructed as responses to a dilemma concerning how to allow for the ascription of health and disease to artefactual organisms without at the same time opening up the possibility of diseased nonliving artefacts such as cars and computers. It is argued that neither response will enable us to ascribe health and disease to artefactual organisms, because both theories, in order to rule out the possibility of ascribing health and disease to nonliving artefacts, make such ascriptions conditional on having a natural-selection history or being part of a species which has been designed by evolution. PMID:24010853

  10. Transport and optical properties of low-dimensional complex systems

    NASA Astrophysics Data System (ADS)

    Iurov, Andrii

    Over the last five years of my research work, I, my research was mainly concerned with certain crucial tunneling, transport and optical properties of novel low-dimensional graphitic and carbon-based materials as well as topological insulators. Both single-electron and many-body problems were addressed. We investigated the Dirac electrons transmission through a potential barrier in the presence of circularly polarized light. An anomalous photon-assisted enhanced transmission is predicted and explained in a comparison with the well-known Klein paradox. It is demonstrated that the perfect transmission for nearly-head-on collision in an infinite graphene is suppressed in gapped dressed states of electrons, which is further accompanied by shift of peaks as a function of the incident angle away from the head-on collision. We calculate the energy bands for graphene monolayers when electrons move through a periodic electrostatic potential in the presence of a uniform perpendicular magnetic field. We clearly demonstrate the quantum fractal nature of the energy bands at reasonably low magnetic fields. We present results for the energy bands as functions of both wave number and magnetic flux through the unit cells of the resulting moiŕe superlattice. This feature is also observed at extremely high magnetic fields. We have discovered a novel feature in the plasmon excitations for a pair of Coulomb-coupled non-concentric spherical two-dimensional electron gases (S2DEGs). Our results show that the plasmon excitations for such pairs depend on the orientation with respect to the external electromagnetic probe field. The origin of this anisotropy of the inter-sphere Coulomb interaction is due to the directional asymmetry of the electrostatic coupling of electrons in excited states which depend on both the angular momentum quantum number L and its projection M on the axis of quantization taken as the probe E-field direction. Such an effect from the plasmon spatial correlation is

  11. Glass formation and properties in the gallia-calcia system

    NASA Technical Reports Server (NTRS)

    Whichard, G.; Day, D. E.

    1984-01-01

    The critical cooling rate for glass formation was measured for five compositions in the Ga2O3-CaO system and varied from a low of (315 + or - 85) C/s for a eutectic melt containing 37.5 mol pct Ga2O3 to a high of (840 + or - 60) C/s for a melt containing 52 mol pct Ga2O3. The density and refractive index both increased with increasing Ga2O3 content, but the crystallization temperature and microhardness varied only slightly. The IR spectra of these glasses suggest that both GaO4 tetrahedra and GaO6 octahedra are present.

  12. Fuel property effects on Navy aircraft fuel systems

    NASA Technical Reports Server (NTRS)

    Moses, C. A.

    1984-01-01

    Problems of ensuring compatibility of Navy aircraft with fuels that may be different than the fuels for which the equipment was designed and qualified are discussed. To avoid expensive requalification of all the engines and airframe fuel systems, methodologies to qualify future fuels by using bench-scale and component testing are being sought. Fuel blends with increasing JP5-type aromatic concentration were seen to produce less volume swell than an equivalent aromatic concentration in the reference fuel. Futhermore, blends with naphthenes, decalin, tetralin, and naphthalenes do not deviate significantly from the correlation line of aromatic blends, Similar results are found with tensile strenth and elongation. Other elastomers, sealants, and adhesives are also being tested.

  13. Thermodynamic properties of mesoscale convective systems observed during BAMEX

    SciTech Connect

    Correia, James; Arritt, R.

    2008-11-01

    Dropsonde observations from the Bow-echo and Mesoscale convective vortex EXperiment (BAMEX) are used to document the spatio-temporal variability of temperature, moisture and wind within mesoscale convective systems (MCSs). Onion type sounding structures are found throughout the stratiform region of MCSs but the temperature and moisture variability is large. Composite soundings were constructed and statistics of thermodynamic variability were generated within each sub-region of the MCS. The calculated air vertical velocity helped identify subsaturated downdrafts. We found that lapse rates within the cold pool varied markedly throughout the MCS. Layered wet bulb potential temperature profiles seem to indicate that air within the lowest several km comes from a variety of source regions. We also found that lapse rate transitions across the 0 C level were more common than isothermal, melting layers. We discuss the implications these findings have and how they can be used to validate future high resolution numerical simulations of MCSs.

  14. System for throttling and compensation for variable feedstock properties

    DOEpatents

    Meyer, J. W.

    1981-05-05

    Apparatus is shown for adjusting the feed rate of pulverized feed material into a pressurized container. The apparatus also has utility for compensating for variations in the permeability of the feed material. A rotor that includes sprues with provision for controlling the pressure distribution along the sprues is located within the pressurized container. The rotor hub is connected to a drive means and a material supply means which extend through the wall of the container. A line for controlling pressure along the sprues by gas injection is connected to a chamber between sections of the sprue for controlling gas pressure at that point. The gas pressure control line is connected to a pressurized gas source and a control system external to the rotor. 10 figs.

  15. System for throttling and compensation for variable feedstock properties

    DOEpatents

    Meyer, John W.

    1981-01-01

    Apparatus is shown for adjusting the feed rate of pulverized feed material into a pressurized container. The apparatus also has utility for compensating for variations in the permeability of the feed material. A rotor that includes sprues with provision for controlling the pressure distribution along the sprues is located within the pressurized container. The rotor hub is connected to a drive means and a material supply means which extend through the wall of the container. A line for controlling pressure along the sprues by gas injection is connected to a chamber between sections of the sprue for controlling gas pressure at that point. The gas pressure control line is connected to a pressurized gas source and a control system external to the rotor.

  16. LDA++ Approach to Electronic And Magnetic Properties of Correlated Systems

    NASA Astrophysics Data System (ADS)

    Katsnelson, Mikhail

    2000-03-01

    A general approach to the realistic calculations of electronic structure of correlated systems, starting from the Local Density Approximation (so-called LDA++) is discussed. In this technique the interatomic electron interactions of Hubbard type is taken into account with the only an assumption about the locality of the electron self-energy, i.e. the latter is considered to be energy- but not momentum-dependent. In such LDA++ method, in contrast with the density functional (DF) approaches, the thermodynamic potential is considered as a Baym-Kadanoff generating functional of the Green function but not of electron density. Analogs of some useful general theorems of DF method, such as local force theorem, are proven for this method and general expressions for effective magnetic interactions in LDA++ approach are obtained. Multiband generalization of the dynamical mean-field theory (DMFT) with the Quantum Monte Carlo (QMC) solution of effective multielectron impurity problem is shown to be the most rigorous form of LDA++. Electron and magnon spectra of iron are calculated within QMC-DMFT scheme starting from the LDA band structure. Spin-polarized photoelectron, thermoemission and other spectra of iron-group metals demonstrate good agreement with experimental data including such features which are caused by the damping of quasiparticles or incoherent (spin-polaron) contributions to the Green function. The latter cannot be considered in the LDA, or LDA+U ``mean-field'' like approximations. We discuss the applications of LDA++ scheme to the different systems including high-Tc superconductors and f-electron compounds.

  17. Property Accounting for State and Local School Systems. Bulletin, 1959, No. 22

    ERIC Educational Resources Information Center

    Reason, Paul L., Comp.; Tankard, George G., Jr., Comp.

    1959-01-01

    This handbook is a guide to property accounting for local and State school systems. It classifies and defines the specific items of information about land, buildings, and equipment that need to be comparable among local school systems and among States, and presents additional terminology essential to their effective use. As such, it is concerned…

  18. The Equity, Adequacy and Educational Effects of a Property Tax Redistribution Finance System: Vermont's Act 60.

    ERIC Educational Resources Information Center

    Mathis, William J.; Fleming, Brenda L.

    Vermont's Act 60 is arguably the most equitable school funding system in the nation. However, it is also one of the most controversial. The disputes are primarily focused on the recapture provision that sends excess revenues from property-rich towns to the state's education trust fund. After a 4-year implementation period, the system is now in its…

  19. Landscape variation in soil properties and potential impacts on biofuel cropping systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Goals: •Compare perennial grass systems v. a continuous corn (Zea mays) system in terms of soil inputs, soil property changes and yield •Potential benefits of perennials: can be grown on marginal crop land, potentially lower input levels, potentially higher biomass yield, and potentially increased s...

  20. Soil physical properties of agricultural systems in a large-scale study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A large-scale field study was performed to determine the effects of agricultural management systems on soil physical properties, including their spatial and temporal variations. Replicates were established in 1998 at the Center for Environmental Farming Systems, Goldsboro, North Carolina; replicates...

  1. Conservation properties and potential systems of vorticity-type equations

    SciTech Connect

    Cheviakov, Alexei F.

    2014-03-15

    Partial differential equations of the form divN=0, N{sub t}+curl M=0 involving two vector functions in R{sup 3} depending on t, x, y, z appear in different physical contexts, including the vorticity formulation of fluid dynamics, magnetohydrodynamics (MHD) equations, and Maxwell's equations. It is shown that these equations possess an infinite family of local divergence-type conservation laws involving arbitrary functions of space and time. Moreover, it is demonstrated that the equations of interest have a rather special structure of a lower-degree (degree two) conservation law in R{sup 4}(t,x,y,z). The corresponding potential system has a clear physical meaning. For the Maxwell's equations, it gives rise to the scalar electric and the vector magnetic potentials; for the vorticity equations of fluid dynamics, the potentialization inverts the curl operator to yield the fluid dynamics equations in primitive variables; for MHD equations, the potential equations yield a generalization of the Galas-Bogoyavlenskij potential that describes magnetic surfaces of ideal MHD equilibria. The lower-degree conservation law is further shown to yield curl-type conservation laws and determined potential equations in certain lower-dimensional settings. Examples of new nonlocal conservation laws, including an infinite family of nonlocal material conservation laws of ideal time-dependent MHD equations in 2+1 dimensions, are presented.

  2. Optomechanical properties of a particle-waveguide system

    NASA Astrophysics Data System (ADS)

    Maslov, A. V.

    2014-09-01

    The balances of the electromagnetic powers and momentum flows for the system of a dielectric particle and a dielectric slab waveguide are studied. The emphasis is made on the regime when whispering gallery resonances in the particle are excited. The excitation is achieved by a guided mode that has either transverse electric or magnetic polarization. The scattering problem is solved by using an analytical representation of the solution with subsequent numerical approach to find the scattered fields with high accuracy. It accounts rigorously for the interaction between the particle and the waveguide. It is found that the propelling force on the particle can be comparable to or even exceed the value of the momentum flow of the incident mode. This is related to a highly anisotropic angular distribution of the bulk radiation that can carry some noticeable momentum in the longitudinal direction. The bulk radiation carries also nonvanishing momentum in the transverse direction giving rise to a difference in the transverse forces experienced by the particle and by the waveguide. The strong coupling between the particle and the waveguide operating in the single-mode regime is shown to upshift slightly the resonant frequencies with decreasing gap between the particle and the waveguide.

  3. Connecting the Silicate Dust and Gas Properties of Distant Galaxies Using Quasar Absorption Systems

    NASA Astrophysics Data System (ADS)

    Aller, Monique C.; Kulkarni, Varsha P.; York, Donald G.; Welty, Daniel E.; Vladilo, Giovanni; Som, Debopam; Lackey, Kyle; Dwek, Eli; Beiranvand, Nassim; Morrison, Sean

    2016-01-01

    We present recent results from our program investigating the silicate dust properties in distant galaxies using quasar absorption systems. The dust and gas properties of distant galaxies can be characterized by studying the absorption features produced by them along the sightlines to luminous background quasars. Based on our prior finding that silicate dust absorption in z<1.5 quasar absorption systems exhibits a range of optical depths and absorption feature substructures, suggestive of silicate grain property variations, we are investigating silicate dust absorption in quasar absorption systems toward quasars with archival Spitzer Space Telescope Infrared Spectrograph (IRS) spectra. We present our measurements of the 10 and/or 18 micron silicate dust absorption feature(s) in these systems, and discuss constraints on the grain properties, such as composition and crystallinity, based on the shape and substructure present in these features. We also investigate the correlations between the silicate dust properties and the reddening. Connections between the silicate dust and gas phase metal absorption properties can also be probed for some of our targets with archival ground-based spectra. These relationships will yield valuable insights into the star formation history and evolution of metals and dust. This work is supported by NASA through ADAP grant NNX14AG74G and by an award issued by JPL/Caltech, and from US-NSF grant AST-1108830 to the University of South Carolina.

  4. On the suitability of Yule process to stochastically model some properties of object-oriented systems

    NASA Astrophysics Data System (ADS)

    Concas, Giulio; Marchesi, Michele; Pinna, Sandro; Serra, Nicola

    2006-10-01

    We present a study of three large object-oriented software systems-VisualWorks Smalltalk, Java JDK and Eclipse-searching for scaling laws in some of their properties. We study four system properties related to code production, namely the inheritance hierarchies, the naming of variables and methods, and the calls to methods. We systematically found power-law distributions in these properties, most of which have never been reported before. We were also able to statistically model the programming activities leading to the studied properties as Yule processes, with very good correspondence between empirical data and the prediction of Yule model. The fact that a design and optimization process like software development can be modeled on the large with the laws of statistical physics poses intriguing issues to software engineers, and could be exploited for finding new metrics and quality measures.

  5. Interstellar Silicate Dust Grain Properties in Distant Galaxies Probed by Quasar Absorption Systems

    NASA Astrophysics Data System (ADS)

    Aller, Monique C.; Kulkarni, Varsha P.; York, Donald G.; Welty, Daniel E.; Vladilo, Giovanni; Som, Debopam

    2015-01-01

    Dust grains are a fundamental component of the interstellar medium, and significantly impact many of the physical processes driving galaxy evolution, including star formation, and the heating, cooling and ionization of interstellar material. Using the absorption features produced by dust in the spectra of luminous background quasars, it is possible to study the properties of extragalactic interstellar dust grains. We will present results from an ongoing program utilizing existing Spitzer Space Telescope infrared quasar spectra to probe silicate dust grain properties in z<1.4 quasar absorption systems. In combination with complementary ground-based data on associated gas-phase metal absorption lines, we explore connections between the interstellar dust and gas in the quasar absorption systems. Our project yields clear detections of the 10 micron silicate dust absorption feature in the studied systems, as well as detections of the 18 micron silicate dust absorption feature in sources with adequate spectral coverage. Based on measured variations in the breath, peak wavelength, and substructure of the 10 micron absorption features, there appear to be differences in the silicate dust grain properties from system-to-system. We also show indications of trends between the gas-phase metal properties, such as metallicity and gas velocity spread, with the silicate dust grain absorption properties. Support for this work is provided by NASA through an award issued by JPL/Caltech and through NASA grant NNX14AG74G, and from National Science Foundation grants AST-0908890 and AST-1108830 to the University of South Carolina.

  6. The study of dielectric, pyroelectric and piezoelectric properties on hot pressed PZT-PMN systems

    SciTech Connect

    Srivastava, Geetika; Umarji, A. M.; Maglione, Mario

    2012-12-15

    Hot uniaxial pressing technique has been adopted for the densification of PZT-PMN system with an aim to yield dense ceramics and to lower the sintering temperature and time for achieving better and reproducible electronic properties. The ceramics having >97% theoretical density and micron size grains are investigated for their dielectric, pyroelectric and piezoelectric properties. The effect of Li and Mn addition has also been studied.

  7. Modelling and properties of a nonlinear autonomous switching system in fed-batch culture of glycerol

    NASA Astrophysics Data System (ADS)

    Wang, Juan; Sun, Qingying; Feng, Enmin

    2012-11-01

    A nonlinear autonomous switching system is proposed to describe the coupled fed-batch fermentation with the pH as the feedback parameter. We prove the non-Zeno behaviors of the switching system and some basic properties of its solution, including the existence, uniqueness, boundedness and regularity. Numerical simulation is also carried out, which reveals that the proposed system can describe the factual fermentation process properly.

  8. Development of a MSW classification system for the evaluation of mechanical properties.

    PubMed

    Dixon, Neil; Langer, Ulrich

    2006-01-01

    To date, sparse information is available on the mechanical properties of municipal solid waste and the results of published work are often hard to compare due to differences in waste composition and therefore properties. To allow comparison, a unified classification system for waste is deemed crucial. Existing classification systems are presented and discussed. For a geotechnical classification, mechanical properties, size, shape and degradability potential of waste components have to be taken into account. A new and improved classification system for waste components is proposed, which complies with the requirements of a geotechnical classification system. It classifies waste components based on: (1) their material engineering properties (e.g., shear, compressive and tensile strength), (2) a size distribution of the components, (3) the component shape (reinforcing, compressible and incompressible), and (4) the degree of degradability. The proposed classification system is applied to data from the literature and methods for presenting classification information are demonstrated. Further work required to develop a full classification system for waste bodies is highlighted. PMID:15908195

  9. A Measure-Theoretic Proof of the Markov Property for Hybrid Systems with Markovian Inputs

    NASA Technical Reports Server (NTRS)

    Tejada, Arturo; Gonzalez, Oscar R.; Gray, W. Steven

    2006-01-01

    The behavior of a general hybrid system in discrete time can be represented by a non-linear difference equation x(k+1) = Fk(x(k), theta(k)), where theta(k) is assumed to be a finite state Markov chain. An important step in the stability analysis of these systems is to establish the Markov property of (x(k), theta(k)). There are, however, no complete proofs of this property which are simple to understand. This paper aims to correct this problem by presenting a complete and explicit proof, which uses only basic measure-theoretical concepts.

  10. On the Markov Property for Nonlinear Discrete-Time Systems with Markovian Inputs

    NASA Technical Reports Server (NTRS)

    Tejada, Arturo; Gonzalez, Oscar R.; Gray, W. Steven

    2006-01-01

    The behavior of a general hybrid system in discrete-time can be represented by a non-linear difference equation x(k + 1) = Fk(x(k), theta(k)), where theta(k) is assumed to be a finite-state Markov chain. An important step in the stability analysis of these systems is to establish the Markov property of (x(k), theta(k)). There are, however, no complete proofs of this property which are simple to understand. This paper aims to correct this problem by presenting a complete and explicit proof, which uses only fundamental measure-theoretical concepts.

  11. Apollo Soyuz Test Project Weights and Mass Properties Operational Management System

    NASA Technical Reports Server (NTRS)

    Collins, M. A., Jr.; Hischke, E. R.

    1975-01-01

    The Apollo Soyuz Test Project (ASTP) Weights and Mass Properties Operational Management System was established to assure a timely and authoritative method of acquiring, controlling, generating, and disseminating an official set of vehicle weights and mass properties data. This paper provides an overview of the system and its interaction with the various aspects of vehicle and component design, mission planning, hardware and software simulations and verification, and real-time mission support activities. The effect of vehicle configuration, design maturity, and consumables updates is discussed in the context of weight control.

  12. Properties of low-redshift QSO absorption systems - QSO-galaxy pairs

    NASA Technical Reports Server (NTRS)

    Womble, Donna S.

    1993-01-01

    The chance proximity of QSOs and galaxies provides unique opportunities to probe the extent and content of gas in the foreground galaxies through evaluation of the incidence and strength of absorption lines in the spectra of the background QSOs. Recent results on the observed properties of these low-redshift, heavy-element absorption systems are summarized. These results are discussed in the context of the galaxy morphologies and environments and are briefly compared with Galactic absorption and with the inferred properties of higher-redshift QSO absorption systems.

  13. Simple display system of mechanical properties of cells and their dispersion.

    PubMed

    Shimizu, Yuji; Kihara, Takanori; Haghparast, Seyed Mohammad Ali; Yuba, Shunsuke; Miyake, Jun

    2012-01-01

    The mechanical properties of cells are unique indicators of their states and functions. Though, it is difficult to recognize the degrees of mechanical properties, due to small size of the cell and broad distribution of the mechanical properties. Here, we developed a simple virtual reality system for presenting the mechanical properties of cells and their dispersion using a haptic device and a PC. This system simulates atomic force microscopy (AFM) nanoindentation experiments for floating cells in virtual environments. An operator can virtually position the AFM spherical probe over a round cell with the haptic handle on the PC monitor and feel the force interaction. The Young's modulus of mesenchymal stem cells and HEK293 cells in the floating state was measured by AFM. The distribution of the Young's modulus of these cells was broad, and the distribution complied with a log-normal pattern. To represent the mechanical properties together with the cell variance, we used log-normal distribution-dependent random number determined by the mode and variance values of the Young's modulus of these cells. The represented Young's modulus was determined for each touching event of the probe surface and the cell object, and the haptic device-generating force was calculated using a Hertz model corresponding to the indentation depth and the fixed Young's modulus value. Using this system, we can feel the mechanical properties and their dispersion in each cell type in real time. This system will help us not only recognize the degrees of mechanical properties of diverse cells but also share them with others. PMID:22479595

  14. Property-Based Monitoring of Analog and Mixed-Signal Systems

    NASA Astrophysics Data System (ADS)

    Havlicek, John; Little, Scott; Maler, Oded; Nickovic, Dejan

    In the recent past, there has been a steady growth of the market for consumer embedded devices such as cell phones, GPS and portable multimedia systems. In embedded systems, digital, analog and software components are combined on a single chip, resulting in increasingly complex designs that introduce richer functionality on smaller devices. As a consequence, the potential insertion of errors into a design becomes higher, yielding an increasing need for automated analog and mixed-signal validation tools. In the purely digital setting, formal verification based on properties expressed in industrial specification languages such as PSL and SVA is nowadays successfully integrated in the design flow. On the other hand, the validation of analog and mixed-signal systems still largely depends on simulation-based, ad-hoc methods. In this tutorial, we consider some ingredients of the standard verification methodology that can be successfully exported from digital to analog and mixed-signal setting, in particular property-based monitoring techniques. Property-based monitoring is a lighter approach to the formal verification, where the system is seen as a "black-box" that generates sets of traces, whose correctness is checked against a property, that is its high-level specification. Although incomplete, monitoring is effectively used to catch faults in systems, without guaranteeing their full correctness.

  15. Measuring the electrical properties of soil using a calibrated ground-coupled GPR system

    USGS Publications Warehouse

    Oden, C.P.; Olhoeft, G.R.; Wright, D.L.; Powers, M.H.

    2008-01-01

    Traditional methods for estimating vadose zone soil properties using ground penetrating radar (GPR) include measuring travel time, fitting diffraction hyperbolae, and other methods exploiting geometry. Additional processing techniques for estimating soil properties are possible with properly calibrated GPR systems. Such calibration using ground-coupled antennas must account for the effects of the shallow soil on the antenna's response, because changing soil properties result in a changing antenna response. A prototype GPR system using ground-coupled antennas was calibrated using laboratory measurements and numerical simulations of the GPR components. Two methods for estimating subsurface properties that utilize the calibrated response were developed. First, a new nonlinear inversion algorithm to estimate shallow soil properties under ground-coupled antennas was evaluated. Tests with synthetic data showed that the inversion algorithm is well behaved across the allowed range of soil properties. A preliminary field test gave encouraging results, with estimated soil property uncertainties (????) of ??1.9 and ??4.4 mS/m for the relative dielectric permittivity and the electrical conductivity, respectively. Next, a deconvolution method for estimating the properties of subsurface reflectors with known shapes (e.g., pipes or planar interfaces) was developed. This method uses scattering matrices to account for the response of subsurface reflectors. The deconvolution method was evaluated for use with noisy data using synthetic data. Results indicate that the deconvolution method requires reflected waves with a signal/noise ratio of about 10:1 or greater. When applied to field data with a signal/noise ratio of 2:1, the method was able to estimate the reflection coefficient and relative permittivity, but the large uncertainty in this estimate precluded inversion for conductivity. ?? Soil Science Society of America.

  16. Barium titanate tape properties for MLCC application using different binder systems

    NASA Astrophysics Data System (ADS)

    Yoon, Dang-Hyok

    Most of multilayer ceramic capacitor (MLCC) industries are currently using solvent-based slip systems, although water-based slips have been receiving increasing attention due to reduced health and environmental hazards. The current work focuses on two main fields to meet the challenges in MLCC processing in aqueous media. One is the comparison between water- and solvent-based slip systems using design of experiments (DOE). The other is the understanding of Ba2+ ion leaching behavior in water and its effect on tape properties. For the first part, twenty four kinds of BaTiO3 slips were investigated using three different binder systems: one solvent-based, and two water-based systems. Tape casting, sintering and characterization were conducted. Slip viscosity and tape strength of the green tape depended significantly on the binder type. It was possible to achieve a higher green density for water-based system than that for a solvent-based one. Most of the green body properties from solvent-based system depended on the ceramic powder. On the other hand, the dispersant was the most significant factor for the green body properties of two water-based systems. Sintered properties such as microstructure and dielectric permittivity for three systems depended significantly on the type of ceramic powder. An optimization was performed for each system by means of a scorecard. By choosing the optimum condition, comparable results were drawn for the water-based system compared to a solvent-based one for MLCC application. For the second part, the amount of Ba2+ ion leaching from BaTiO3 in water was determined by an EDTA titration method. The greater extent and the faster rate of Ba2+ leaching were found at the lower solution pH. The excess free barium ions expressed by means of the Ba/Ti ratio adversely affected most tape properties. To passivate BaTiO 3 surface from Ba2+ ion leaching in water, passivation agent layer (PAL) was formed by drying the slurry after adding a commercial

  17. Impact of Organic and Conventional Systems of Coffee Farming on Soil Properties and Culturable Microbial Diversity.

    PubMed

    Velmourougane, Kulandaivelu

    2016-01-01

    A study was undertaken with an objective of evaluating the long-term impacts of organic (ORG) and conventional (CON) methods of coffee farming on soil physical, chemical, biological, and microbial diversity. Electrical conductivity and bulk density were found to increase by 34% and 21%, respectively, in CON compared to ORG system, while water holding capacity was found decreased in both the systems. Significant increase in organic carbon was observed in ORG system. Major nutrients, nitrogen and potassium, levels showed inclination in both ORG and CON system, but the trend was much more pronounced in CON system. Phosphorus was found to increase in both ORG and CON system, but its availability was found to be more with CON system. In biological attributes, higher soil respiration and fluorescein diacetate activity were recorded in ORG system compared to CON system. Higher soil urease activity was observed in CON system, while dehydrogenase activity does not show significant differences between ORG and CON systems. ORG system was found to have higher macrofauna (31.4%), microbial population (34%), and microbial diversity indices compared to CON system. From the present study, it is accomplished that coffee soil under long-term ORG system has better soil properties compared to CON system. PMID:27042378

  18. Impact of Organic and Conventional Systems of Coffee Farming on Soil Properties and Culturable Microbial Diversity

    PubMed Central

    2016-01-01

    A study was undertaken with an objective of evaluating the long-term impacts of organic (ORG) and conventional (CON) methods of coffee farming on soil physical, chemical, biological, and microbial diversity. Electrical conductivity and bulk density were found to increase by 34% and 21%, respectively, in CON compared to ORG system, while water holding capacity was found decreased in both the systems. Significant increase in organic carbon was observed in ORG system. Major nutrients, nitrogen and potassium, levels showed inclination in both ORG and CON system, but the trend was much more pronounced in CON system. Phosphorus was found to increase in both ORG and CON system, but its availability was found to be more with CON system. In biological attributes, higher soil respiration and fluorescein diacetate activity were recorded in ORG system compared to CON system. Higher soil urease activity was observed in CON system, while dehydrogenase activity does not show significant differences between ORG and CON systems. ORG system was found to have higher macrofauna (31.4%), microbial population (34%), and microbial diversity indices compared to CON system. From the present study, it is accomplished that coffee soil under long-term ORG system has better soil properties compared to CON system. PMID:27042378

  19. Glass formation and physical properties of chalcogenide glasses in Ge-S-Pb system

    NASA Astrophysics Data System (ADS)

    Qu, Guoshun; Lin, Changgui; Li, Zhuobin; Zhai, Sumin; Gu, Shaoxuan; Tao, Haizheng; Xu, Tiefeng

    2014-03-01

    Chalcogenide glasses based on Ge-S-Pb system were prepared, and the compositional dependence of their physic-chemical properties and glass structure were investigated. Up to 23 mol% Pb can be dissolved in this glass system and the glass-formation region like a small isolated island was found. The effect of the introduction of Pb on the glass structure is discussed by employing Raman spectra. It is shown that the substitution of Pb for Ge decreases the number of [GeS4] and [S3Ge-GeS3] units, leading to the variation of properties, such as Tg, H‧, and Hv. The knowledge of this structure-properties relationship of Ge-S-Pb glasses would be of significance to select or to design suitable host glass for optoelectronic applications.

  20. Atomistic Modeling of Surface and Bulk Properties of Cu, Pd and the Cu-Pd System

    NASA Technical Reports Server (NTRS)

    Bozzolo, Guillermo; Garces, Jorge E.; Noebe, Ronald D.; Abel, Phillip; Mosca, Hugo O.; Gray, Hugh R. (Technical Monitor)

    2002-01-01

    The BFS (Bozzolo-Ferrante-Smith) method for alloys is applied to the study of the Cu-Pd system. A variety of issues are analyzed and discussed, including the properties of pure Cu or Pd crystals (surface energies, surface relaxations), Pd/Cu and Cu/Pd surface alloys, segregation of Pd (or Cu) in Cu (or Pd), concentration dependence of the lattice parameter of the high temperature fcc CuPd solid solution, the formation and properties of low temperature ordered phases, and order-disorder transition temperatures. Emphasis is made on the ability of the method to describe these properties on the basis of a minimum set of BFS universal parameters that uniquely characterize the Cu-Pd system.

  1. The Intrinsic Electrophysiological Properties of Mammalian Neurons: Insights into Central Nervous System Function

    NASA Astrophysics Data System (ADS)

    Llinas, Rodolfo R.

    1988-12-01

    This article reviews the electroresponsive properties of single neurons in the mammalian central nervous system (CNS). In some of these cells the ionic conductances responsible for their excitability also endow them with autorhythmic electrical oscillatory properties. Chemical or electrical synaptic contacts between these neurons often result in network oscillations. In such networks, autorhytmic neurons may act as true oscillators (as pacemakers) or as resonators (responding preferentially to certain firing frequencies). Oscillations and resonance in the CNS are proposed to have diverse functional roles, such as (i) determining global functional states (for example, sleep-wakefulness or attention), (ii) timing in motor coordination, and (iii) specifying connectivity during development. Also, oscillation, especially in the thalamo-cortical circuits, may be related to certain neurological and psychiatric disorders. This review proposes that the autorhythmic electrical properties of central neurons and their connectivity form the basis for an intrinsic functional coordinate system that provides internal context to sensory input.

  2. Mechanical properties of the Shuttle Orbiter thermal protection system strain isolator pad

    NASA Technical Reports Server (NTRS)

    Sawyer, J. W.

    1982-01-01

    An experimental investigation conducted to determine the static and fatigue properties of the Strain Isolator Pad (SIP) used on the Shuttle Orbiter Thermal protection system is described. Static tension-compression and shear test results show that the SIP is highly nonlinear and that it possesses a large hysteresis, a large low modulus region for low stress levels, and stress-strain properties that are highly sensitive to strain rate and previous load history. In addition, the shear properties are also found to be sensitive to forces applied normal to the plane of the pad and to the orientation of the material. For the undensified tile/SIP system, static and fatigue failure takes place at the SIP/tile interface at low stress levels and for a small number of cycles.

  3. Two-dimensional systems with competing interactions: dynamic properties of single particles and of clusters.

    PubMed

    Schwanzer, Dieter F; Coslovich, Daniele; Kahl, Gerhard

    2016-10-19

    Systems with short-range attractive and long-range repulsive interactions are able to form mesophases at sufficiently low temperatures. In two dimensions, such mesophases emerge as clusters, stripes or bubbles. Using extensive Monte Carlo simulations we investigate the static and the dynamic properties of such a cluster-forming system over a broad temperature range and for different densities. Via the static properties we analyse how ordering into close packed configurations sets in both at the level of the particles as well as at the level of the clusters. The dynamic properties provide information on how, at low temperature, the motion of individual particles is influenced by the dynamic slowing down of the clusters. Finally, we discuss the different diffusion mechanisms at play at low and intermediate densities. PMID:27546155

  4. Thermodynamic properties of alloys of the binary Gd-In system

    NASA Astrophysics Data System (ADS)

    Shevchenko, M. A.; Ivanov, M. I.; Berezutski, V. V.; Sudavtsova, V. S.

    2016-01-01

    The thermochemical properties of melts of the binary Gd-In system were studied by the calorimetry method at 1470-1700 K over the whole concentration interval. It was shown that significant negative heat effects of mixing are characteristic features for these melts. Using the ideal associated solution (IAS) model, the activities of components, Gibbs energies and the entropies of mixing in the alloys of this systems and its phase diagram were calculated. They agree with the data from literature.

  5. Finite Temperature Properties of Three-Component Fermion Systems in Optical Lattice

    NASA Astrophysics Data System (ADS)

    Yanatori, Hiromasa; Koga, Akihisa

    2016-01-01

    We investigate finite temperature properties in the half-filled three-component (colors) fermion systems. It is clarified that a color density-wave (CDW) state is more stable than a color-selective "antiferromagnetic" (CSAF) state against thermal fluctuations. The reentrant behavior in the phase boundary for the CSAF state is found. We also address the maximum critical temperature of the translational symmetry breaking states in the multicomponent fermionic systems.

  6. Growth of complex systems can be related to the properties of their underlying determinants

    PubMed Central

    Savageau, Michael A.

    1979-01-01

    Growth—increase in size, number, or amount—in many cases appears to follow simple empirical laws. Such laws have been noted in a wide variety of fields for many years. Until now these laws have never been related to the underlying determinants of these systems. By starting with fundamental properties of the component mechanisms in such systems, one can derive a basic growth equation for which the well-known laws of growth are special cases. PMID:16592715

  7. Thermodynamic properties of alloys of the binary In-La system

    NASA Astrophysics Data System (ADS)

    Shevchenko, M. A.; Ivanov, M. I.; Berezutski, V. V.; Sudavtsova, V. S.

    2016-06-01

    The thermochemical properties of melts of the binary In-La system were studied by the calorimetry method at 1250-1480 K over the whole concentration interval. It was shown that significant negative heat effects of mixing are characteristic features for these melts. Using the ideal associated solution (IAS) model, the activities of components, Gibbs energies and the entropies of mixing in the alloys, and the phase diagram of this system were calculated. They agree with the data from literature.

  8. Thermodynamic properties of alloys of the binary In-Yb system

    NASA Astrophysics Data System (ADS)

    Shevchenko, M. A.; Ivanov, M. I.; Berezutski, V. V.; Sudavtsova, V. S.

    2016-05-01

    The thermochemical properties of melts of the binary In-Yb system were studied by the calorimetry method at 1160-1380 K over the whole concentration interval. It was shown that significant negative heat effects of mixing are characteristic features for these melts. Using the ideal associated solution (IAS) model, the activities of components, Gibbs energies and the entropies of mixing in the alloys, and the phase diagram of this system were calculated. They agree with the data from literature.

  9. 77 FR 65048 - Privacy Act; System of Records: Personal Property Claims, State-27

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-24

    ...Notice is hereby given that the Department of State proposes to amend an existing system of records, Personal Property Claims, State-27, pursuant to the provisions of the Privacy Act of 1974, as amended (5 U.S.C. 552a) and Office of Management and Budget Circular No. A-130, Appendix...

  10. Sheep Grazing Effect on Dryland Soil Properties and Wheat Yield in the Wheat-Fallow System

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sheep (Ovis aries L.) grazing during fallow is an effective method of controlling weeds and pests in the wheat (Triticum aestivum L.)-fallow system. Little is known about the effect of sheep grazing on dryland soil properties and wheat yield. We evaluated the effects of fallow management for weed co...

  11. Sheep Grazing in the Wheat-Fallow System Affects Dryland Soil Properties and Grain Yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sheep (Ovis aries L.) grazing during fallow is an effective method of controlling weeds and pests in the wheat (Triticum aestivum L.)-fallow system. Little is known about the effect of sheep grazing on dryland soil properties and wheat yield. We evaluated the effects of fallow management for weed co...

  12. Synthesis of silver nanoparticles in textile finish aqueous system and their antimicrobial properties on cotton fibers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Silver nanoparticles (NPs) were synthesized by a simple and environmentally benign procedure using poly (ethylene glycol) (PEG) as reducing agent and stabilizer in the textile finish aqueous system, and their antimicrobial properties on greige (mechanically cleaned) and bleached cotton fibers were i...

  13. Pomological and nutraceutical properties in apricot fruit: cultivation systems and cold storage fruit management.

    PubMed

    Leccese, Annamaria; Bureau, Sylvie; Reich, Maryse; Renard, M G C Catherine; Audergon, Jean-Marc; Mennone, Carmelo; Bartolini, Susanna; Viti, Raffaella

    2010-06-01

    We have investigated the effect of cultivation systems and fruit post-harvest management on the antioxidant properties of apricot fruits. Trees of five cultivars 'Tyrinthos', 'Cafona', 'Bella d'Italia', 'Vitillo' and 'Pellecchiella' were cultivated under integrated and organic systems. Fruits were collected at full maturity stage and analyzed either immediately or after storage at 4+/-0.5 degrees C and 85% of relative humidity for seven and 14 days. The main pomological traits (weight, colour, flesh firmness, total soluble sugars, titratable acidity) and antioxidant properties were analyzed. The total antioxidant capacity (TAC by TEAC method), total phenols content (TP by Folin-Ciocalteu method) and carotenoid content by HPLC-DAD were monitored. Cultivar characterization by principal component analysis (PCA) indicated a large variability on pomological and antioxidant properties of apricot fruits. 'Bella d'Italia' showed better TAC and TP values compared to the other cultivars. ANOVA interactions between cultivar and cultivation system (organic/integrated) were found for the antioxidant properties. These interactions may help to select a set of genotypes with better performances under organic system, which in our study might be indicated in 'Cafona' and 'Bella d'Italia'. PMID:20198441

  14. 25 CFR 900.54 - Should the property management system prescribe internal controls?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false Should the property management system prescribe internal controls? 900.54 Section 900.54 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR, AND INDIAN HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES CONTRACTS UNDER THE INDIAN SELF-DETERMINATION AND EDUCATION ASSISTANCE ACT Standards...

  15. 25 CFR 900.53 - What kind of records shall the property management system maintain?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false What kind of records shall the property management system maintain? 900.53 Section 900.53 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR, AND INDIAN HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES CONTRACTS UNDER THE INDIAN SELF-DETERMINATION AND EDUCATION ASSISTANCE ACT Standards...

  16. Luminescence properties of Si-containing porous matrix–PbS nanoparticle systems

    SciTech Connect

    Tarasov, S. A. Aleksandrova, O. A.; Lamkin, I. A.; Maksimov, A. I.; Maraeva, E. V.; Mikhailov, I. I.; Moshnikov, V. A.; Musikhin, S. F.; Nalimova, S. S.; Permyakov, N. V.; Spivak, Yu. M.; Travkin, P. G.

    2015-12-15

    The luminescence properties of systems that contain lead-sulfide nanoparticles deposited onto substrates fabricated from porous silicon, oxidized porous silicon, and porous (tin-oxide)–(silicon-oxide) layers are studied. It is shown that the structure and composition of the matrix induce a strong effect on the luminescence spectra of colloidal quantum dots, defining their emission wavelength.

  17. Computational Tools for Predictive Modeling of Properties in Complex Actinide Systems

    SciTech Connect

    Autschbach, Jochen; Govind, Niranjan; Atta Fynn, Raymond; Bylaska, Eric J.; Weare, John H.; de Jong, Wibe A.

    2015-03-30

    In this chapter we focus on methodological and computational aspects that are key to accurately modeling the spectroscopic and thermodynamic properties of molecular systems containing actinides within the density functional theory (DFT) framework. Our focus is on properties that require either an accurate relativistic all-electron description or an accurate description of the dynamical behavior of actinide species in an environment at finite temperature, or both. The implementation of the methods and the calculations discussed in this chapter were done with the NWChem software suite (Valiev et al. 2010). In the first two sections we discuss two methods that account for relativistic effects, the ZORA and the X2C Hamiltonian. Section 1.2.1 discusses the implementation of the approximate relativistic ZORA Hamiltonian and its extension to magnetic properties. Section 1.3 focuses on the exact X2C Hamiltonian and the application of this methodology to obtain accurate molecular properties. In Section 1.4 we examine the role of a dynamical environment at finite temperature as well as the presence of other ions on the thermodynamics of hydrolysis and exchange reaction mechanisms. Finally, Section 1.5 discusses the modeling of XAS (EXAFS, XANES) properties in realistic environments accounting for both the dynamics of the system and (for XANES) the relativistic effects.

  18. Connecting the Interstellar Gas and Dust Properties in Distant Galaxies Using Quasar Absorption Systems

    NASA Astrophysics Data System (ADS)

    Aller, Monique Christine; Kulkarni, Varsha P.; York, Donald; Welty, Daniel; Vladilo, Giovanni; Som, Debopam; Lackey, Kyle; Dwek, Eli

    2015-08-01

    Gas and dust grains are fundamental components of the interstellar medium and significantly impact many of the physical processes driving galaxy evolution, such as star-formation, and the heating, cooling, and ionization of the interstellar material. Quasar absorption systems (QASs), which trace intervening galaxies along the sightlines to luminous quasars, provide a valuable tool to directly study the properties of the interstellar gas and dust in distant, normal galaxies. We have established the presence of silicate dust grains in at least some gas-rich QASs, and find that they exist at higher optical depths than expected for diffuse gas in the Milky Way. Differences in the absorption feature shapes additionally suggest variations in the silicate dust grain properties, such as in the level of grain crystallinity, from system-to-system. Recent studies of QASs also find trends in both the gas and dust properties, such as correlations in metallicity with redshift and dust depletions. We present results from a study of the gas and dust properties of QASs with adequate archival IR data to probe the silicate dust grain properties. We discuss our measurements of gas-phase element abundances based on archival high-resolution optical spectra. We also discuss our measurements of the strengths of the 10 and 18 micron silicate dust absorption features in the QASs, and constraints on the grain properties (e.g., composition, shape, crystallinity) based on fitted silicate profile templates. We investigate correlations between absorption redshift, gas metallicity, metal depletions, and silicate dust abundance, which will yield valuable insights into the star formation history. Support is provided by NASA through grant NNX14AG74G and by an award issued by JPL/Caltech, and from US-NSF grants AST-0908890 and AST-1108830 to the U. of S. Carolina.

  19. Structure-property relationships of electron-beam-irradiated monomeric and polymeric systems

    SciTech Connect

    Kim, Ha Chul.

    1989-01-01

    Structure-property relationships were investigated for electron beam (EB) irradiated monomeric and polymeric systems. The objectives were to study the feasibility of preparing systems of potential application, and to characterize these systems in terms of structure-property behavior. In this thesis, the basic theories on radiation chemistry were first reviewed. Next, five different studies on the application of EB radiation were discussed. In the first study on the surface modification of the methacyclic acid derivative of the glycidyl ether of bis-phenol A(bis-GMA) substrates, considerable changes in wetting characteristics were observed using functionalized poly(dimethyl siloxane) (PDMS) oligomers as surface modifiers. The second subject was utilized to cross-linked caprolactone-allyl glycidyl ether(CL-AGE) copolymers. EB radiation was utilized to crosslink these materials at various temperatures both above and below the crystalline melting point. In the third study, models of time-temperature-energy(TTE) diagrams in an idealized EB radiation curing system were developed to help provide a conceptual understanding of the TTE relationship. The fourth study focused on the effects of EB irradiation on the mechanical and thermal properties of poly(phenylene sulfide). In the fifth study, two systems(symmetric and asymmetric) based on the controlled distribution of bis-GMA within a crosslinked nitrile rubber(NBR) network were prepared utilizing EB irradiation.

  20. Impact of future fuel properties on aircraft engines and fuel systems

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.; Grobman, J. S.

    1978-01-01

    This paper describes and discusses the propulsion-system problems that will most likely be encountered if the specifications of hydrocarbon-based jet fuels must undergo significant changes in the future and, correspondingly, the advances in technology that will be required to minimize the adverse impact of these problems. Several investigations conducted are summarized. Illustrations are used to describe the relative effects of selected fuel properties on the behavior of propulsion-system components and fuel systems. The selected fuel properties are those that are most likely to be relaxed in future fuel specifications. Illustrations are also used to describe technological advances that may be needed in the future. Finally, the technological areas needing the most attention are described, and programs that are under way to address these needs are briefly discussed.

  1. Representing Mutually Exclusive Knowledge in a Property Hierarchy for a Reasoning System in Clinical Gynecology

    PubMed Central

    Small, Steven L.; Muechler, Eberhard K.

    1985-01-01

    The education and practice of clinical medicine can benefit significantly from the use of computational assistants. This article describes the development of a prototype system called SURGES (Strong/University of Rochester Gynecological Expert System) for representing medical knowledge and then applying this knowledge to suggest diagnostic procedures in medical gynecology. The paper focuses on the representation technique of property inheritance, which facilitates the simple common sense reasoning required to enable execution of the more complex medical inferences. Such common sense can be viewed as a collection mundane inferences, which are the simple conclusions drawn from knowledge that an exclusive or (XOR) relation (i.e., mutual exclusion) holds among a number of facts. The paper discusses the use of a property hierarchy for this purpose and shows how it simplifies knowledge representation in medical artificial intelligence (AIM) computer systems.

  2. Sorbent Material Property Requirements for On-Board Hydrogen Storage for Automotive Fuel Cell Systems.

    SciTech Connect

    Ahluwalia, R. K.; Peng, J-K; Hua, T. Q.

    2015-05-25

    Material properties required for on-board hydrogen storage in cryogenic sorbents for use with automotive polymer electrolyte membrane (PEM) fuel cell systems are discussed. Models are formulated for physical, thermodynamic and transport properties, and for the dynamics of H-2 refueling and discharge from a sorbent bed. A conceptual storage configuration with in-bed heat exchanger tubes, a Type-3 containment vessel, vacuum insulation and requisite balance-of-plant components is developed to determine the peak excess sorption capacity and differential enthalpy of adsorption for 5.5 wt% system gravimetric capacity and 55% well-to-tank (WTT) efficiency. The analysis also determines the bulk density to which the material must be compacted for the storage system to reach 40 g.L-1 volumetric capacity. Thermal transport properties and heat transfer enhancement methods are analyzed to estimate the material thermal conductivity needed to achieve 1.5 kg.min(-1) H-2 refueling rate. Operating temperatures and pressures are determined for 55% WTT efficiency and 95% usable H-2. Needs for further improvements in material properties are analyzed that would allow reduction of storage pressure to 50 bar from 100 bar, elevation of storage temperature to 175-200 K from 150 K, and increase of WTT efficiency to 57.5% or higher.

  3. Electronic Structure and Ground State Properties of Non-Magnetic NiPt Systems

    NASA Astrophysics Data System (ADS)

    PAUDYAL, DURGA; MOOKERJEE, ABHIJIT

    We have studied the electronic properties like density of states and band structures and also the ground state properties like formation energy, cohesive energy, bulk modulus and structural energy of NiPt system using the linearized muffin-tin orbital method introduced by Andersen.1,2 In an earlier communication we had argued that both charge neutrality and scalar relativistic corrections are very important for the high concentration of Pt alloys. The calculations here, were, therefore, carried out with charge neutrality as well as with and without scalar relativistic correction for comparison.

  4. Polymers for hydrogen infrastructure and vehicle fuel systems : applications, properties, and gap analysis.

    SciTech Connect

    Barth, Rachel Reina; Simmons, Kevin L.; San Marchi, Christopher W.

    2013-10-01

    This document addresses polymer materials for use in hydrogen service. Section 1 summarizes the applications of polymers in hydrogen infrastructure and vehicle fuel systems and identifies polymers used in these applications. Section 2 reviews the properties of polymer materials exposed to hydrogen and/or high-pressure environments, using information obtained from published, peer-reviewed literature. The effect of high pressure on physical and mechanical properties of polymers is emphasized in this section along with a summary of hydrogen transport through polymers. Section 3 identifies areas in which fuller characterization is needed in order to assess material suitability for hydrogen service.

  5. A COAXIAL TE011 CAVITY AND A SYSTEM TO MEASURE DC AND RF PROPERTIES OF SUPERCONDUCTORS

    SciTech Connect

    Gianluigi Ciovati; Peter Kneisel; Ganapati Rao Myneni; Larry Turlington; Gary Slack; Michael Morrone; William Clemens; Richard Bundy; Thomas Elliott; Jayanta Mondal

    2008-01-23

    A coaxial niobium cavity has been designed and built where the center conductor consists of a removable sample. In addition, a system to measure properties such as magnetization, penetration depth, critical temperature and thermal conductivity on the same cylindrical sample has been designed and built. The purpose of this effort is to investigate possible correlations between DC and RF properties of superconductors. In this contribution, the design of the various components is discussed and the test results on a niobium sample obtained so far are presented.

  6. The mechanical properties of radiation-vulcanized NR/BR blending system

    NASA Astrophysics Data System (ADS)

    Aoshuang, Yan; Zhengtao, Guo; Li, Li; Ying, Zhai; Peng, Zhou

    2002-03-01

    The effect of radiation dose on the mechanical properties of NR/BR blending system is reported in this paper. A comparison was made between sulphur vulcanization and radiation vulcanization for an optimal nature rubber (NR)/ butyl rubber (BR) blending ratio (60/40) at dose range from 10 to 150 kGy. The result shows that the mechanical properties, especially, tensile strength, elongation at break, and tear strength have been improved significantly by radiation-vulcanization. This finding was also proved by thermal aging experiment on a selected NR/BR blend at 70°C for up to 168 h.

  7. Porosity Dependence of Piezoelectric Properties for Porous Potassium Niobate System Ceramics

    NASA Astrophysics Data System (ADS)

    Wada, S.; Mase, Y.; Shimizu, S.; Maeda, K.; Fujii, I.; Nakashima, K.; Pulpan, P.; Miyajima, N.

    2011-10-01

    Porous potassium niobate (KNbO3, KN) system ceramics were prepared by a conventional sintering method using carbon black (CB) nanoparticles. First, KN nanoparticles with a size of 100 nm was mixed with CB nanoparticles and binder using ball milling with ethanol. The mixture was dried, and pressed into pellets using uniaxial pressing. After binder burnout, these ceramics was sintered in air. Their piezoelectric properties were measured and discussed a relationship between porosity and piezoelectric properties. As the results, with increasing porosity, piezoelectric g33 constant increased significantly, which suggested that porous ceramics were effective for stress sensor application.

  8. The Two-Component Virial Theorem and the Physical Properties of Stellar Systems.

    PubMed

    Dantas; Ribeiro; Capelato; de Carvalho RR

    2000-01-01

    Motivated by present indirect evidence that galaxies are surrounded by dark matter halos, we investigate whether their physical properties can be described by a formulation of the virial theorem that explicitly takes into account the gravitational potential term representing the interaction of the dark halo with the baryonic or luminous component. Our analysis shows that the application of such a "two-component virial theorem" not only accounts for the scaling relations displayed by, in particular, elliptical galaxies, but also for the observed properties of all virialized stellar systems, ranging from globular clusters to galaxy clusters. PMID:10587482

  9. Fossil group origins. IV. Characterization of the sample and observational properties of fossil systems

    NASA Astrophysics Data System (ADS)

    Zarattini, S.; Barrena, R.; Girardi, M.; Castro-Rodriguez, N.; Boschin, W.; Aguerri, J. A. L.; Méndez-Abreu, J.; Sánchez-Janssen, R.; Catalán-Torrecilla, C.; Corsini, E. M.; del Burgo, C.; D'Onghia, E.; Herrera-Ruiz, N.; Iglesias-Páramo, J.; Jimenez Bailon, E.; Lozada Muoz, M.; Napolitano, N.; Vilchez, J. M.

    2014-05-01

    Context. Virialized halos grow by the accretion of smaller ones in the cold dark matter scenario. The rate of accretion depends on the different properties of the host halo. Those halos for which this accretion rate was very fast and efficient resulted in systems dominated by a central galaxy surrounded by smaller galaxies that were at least two magnitudes fainter. These galaxy systems are called fossil systems, and they can be the fossil relics of ancient galaxy structures. Aims: We started an extensive observational program to characterize a sample of 34 fossil group candidates spanning a broad range of physical properties. Methods: Deep r-band images were obtained with the 2.5-m Isaac Newton Telescope and Nordic Optic Telescope. Optical spectroscopic observations were performed at the 3.5-m Telescopio Nazionale Galileo for ~1200 galaxies. This new dataset was completed with Sloan Digital Sky Survey Data Release 7 archival data to obtain robust cluster membership and global properties of each fossil group candidate. For each system, we recomputed the magnitude gaps between the two brightest galaxies (Δm12) and the first and fourth ranked galaxies (Δm14) within 0.5 R200. We consider fossil systems to be those with Δm12 ≥ 2 mag or Δm14 ≥ 2.5 mag within the errors. Results: We find that 15 candidates turned out to be fossil systems. Their observational properties agree with those of non-fossil systems. Both follow the same correlations, but the fossil systems are always extreme cases. In particular, they host the brightest central galaxies, and the fraction of total galaxy light enclosed in the brightest group galaxy is larger in fossil than in non-fossil systems. Finally, we confirm the existence of genuine fossil clusters. Conclusions: Combining our results with others in the literature, we favor the merging scenario in which fossil systems formed from mergers of L∗ galaxies. The large magnitude gap is a consequence of the extreme merger ratio within

  10. Tuning the photochemical properties of the fulvalene-tetracarbonyl-diruthenium system.

    PubMed

    Lennartson, Anders; Lundin, Angelica; Börjesson, Karl; Gray, Victor; Moth-Poulsen, Kasper

    2016-06-01

    In a Molecular Solar-Thermal Energy Storage (MOST) system, solar energy is converted to chemical energy using a compound that undergoes reversible endothermic photoisomerization. The high-energy photoisomer can later be converted back to the parent compound and the excess energy is released as heat. One of the most studied MOST systems is based on fulvalene-tetracarbonyl-diruthenium, and this paper demonstrates, for the first time, the possibility to tune the photochemical properties of this system by positive steric hindrance working on the fulvalene unit. PMID:27109432

  11. Electrooptical properties of hybrid liquid crystalline systems containing CdSe quantum dots

    SciTech Connect

    Dradrach, K. Bartkiewicz, S.; Miniewicz, A.

    2014-12-08

    In this paper, we present electrooptical properties of hybrid liquid crystalline systems, which contained CdSe quantum dots (QDs). We have shown by experiments of degenerated two-wave mixing and transverse conductivity measurements that liquid crystal cells filled with nematic and doped with semiconductor nanoparticles exhibit photorefractive effect associated with photoconductivity appearing in the system. We also present the mathematical model, which explains the relationship between the photoconductivity of the layer on which the QDs reside and the generation of holographic gratings. Our research may help to develop better understanding of processes observed in such systems and create more efficient materials for holographic data storage.

  12. Electrooptical properties of hybrid liquid crystalline systems containing CdSe quantum dots

    NASA Astrophysics Data System (ADS)

    Dradrach, K.; Bartkiewicz, S.; Miniewicz, A.

    2014-12-01

    In this paper, we present electrooptical properties of hybrid liquid crystalline systems, which contained CdSe quantum dots (QDs). We have shown by experiments of degenerated two-wave mixing and transverse conductivity measurements that liquid crystal cells filled with nematic and doped with semiconductor nanoparticles exhibit photorefractive effect associated with photoconductivity appearing in the system. We also present the mathematical model, which explains the relationship between the photoconductivity of the layer on which the QDs reside and the generation of holographic gratings. Our research may help to develop better understanding of processes observed in such systems and create more efficient materials for holographic data storage.

  13. 32-Channel System to Measure the Electrophysiological Properties of Bioengineered Cardiac Muscle.

    PubMed

    Salazar, Betsy H; Reddy, Anilkumar K; Zewei Tao; Madala, Sridhar; Birla, Ravi K

    2015-06-01

    The purpose of this study was to develop, assess, and validate a custom 32-channel system to analyze the electrical properties of 3-D artificial heart muscle (3D-AHM). In this study, neonatal rat cardiac cells were cultured in a fibrin gel to drive the formation of 3D-AHM. Once the tissues were fully formed, the customized electrocardiogram (EKG) sensing system was used to obtain the different electrophysiological characteristics of the muscle constructs. Additionally, this system was used to evaluate the electrical properties of native rat hearts, for comparison to the fabricated tissues and native values found in the literature. Histological evaluation showed extensive cellularization and cardiac tissue formation. EKG data analysis yielded time delays between the signals ranging from 0 to 7 ms. Optical maps exhibited slight trends in impulse propagation throughout the fabricated tissue. Conduction velocities were calculated longitudinally at 277.81 cm/s, transversely at 300.79 cm/s, and diagonally at 285.68 cm/s for 3D-AHM. The QRS complex exhibited an R-wave amplitude of 438.42 ± 36.96 μV and an average duration of 317.5 ± 16.5 ms for the tissue constructs. The data collected in this study provide a clearer picture about the intrinsic properties of the 3D-AHM while proving our system's efficacy for EKG data procurement. To achieve a viable and permanent solution, the bioengineered heart muscle must physiologically resemble native heart tissue as well as mimic its electrical properties for proper contractile function. This study allows us to monitor such properties and assess the necessary changes that will improve construct development and function. PMID:25667345

  14. Abasy Atlas: a comprehensive inventory of systems, global network properties and systems-level elements across bacteria

    PubMed Central

    Ibarra-Arellano, Miguel A.; Campos-González, Adrián I.; Treviño-Quintanilla, Luis G.; Tauch, Andreas; Freyre-González, Julio A.

    2016-01-01

    The availability of databases electronically encoding curated regulatory networks and of high-throughput technologies and methods to discover regulatory interactions provides an invaluable source of data to understand the principles underpinning the organization and evolution of these networks responsible for cellular regulation. Nevertheless, data on these sources never goes beyond the regulon level despite the fact that regulatory networks are complex hierarchical-modular structures still challenging our understanding. This brings the necessity for an inventory of systems across a large range of organisms, a key step to rendering feasible comparative systems biology approaches. In this work, we take the first step towards a global understanding of the regulatory networks organization by making a cartography of the functional architectures of diverse bacteria. Abasy (Across-bacteria systems) Atlas provides a comprehensive inventory of annotated functional systems, global network properties and systems-level elements (global regulators, modular genes shaping functional systems, basal machinery genes and intermodular genes) predicted by the natural decomposition approach for reconstructed and meta-curated regulatory networks across a large range of bacteria, including pathogenically and biotechnologically relevant organisms. The meta-curation of regulatory datasets provides the most complete and reliable set of regulatory interactions currently available, which can even be projected into subsets by considering the force or weight of evidence supporting them or the systems that they belong to. Besides, Abasy Atlas provides data enabling large-scale comparative systems biology studies aimed at understanding the common principles and particular lifestyle adaptions of systems across bacteria. Abasy Atlas contains systems and system-level elements for 50 regulatory networks comprising 78 649 regulatory interactions covering 42 bacteria in nine taxa, containing 3708

  15. The Effects of Quantum Delocalization on the Structural and Thermodynamic Properties of Many-Body Systems

    NASA Astrophysics Data System (ADS)

    Deckman, Jason

    The following dissertation is an account of my research in the Mandelshtam group at UC Irvine beginning in the Fall of 2006 and ending in the Summer of 2011. My general area of study falls within the realm of equilibrium quantum statistical mechanics, a discipline which attempts to relate molecular-scale properties to time averaged, macroscopic observables. The major tools used herein are the Variational Gaussian Wavepacket (VGW) approximation for quantum calculations, and Monte-Carlo methods, particularly parallel tempering, for global optimization and the prediction of equilibrium thermodynamic properties. Much of my work used these two methods to model both small and bulk systems at equilibrium where quantum effects are significant. All the systems considered are characterized by inter-molecular van der Waals forces, which are weak but significant electrostatic attractions between atoms and molecules and posses a 1/r6 dependence. The research herein begins at the microscopic level, starting with Lennard-Jones (LJ) clusters, then later shifts to the macroscopic for a study involving bulk para-hydrogen. For the LJ clusters the structural transitions induced by a changing deBoer parameter, Λ, a measure of quantum delocalization of the constituent particles, are investigated over a range of cluster sizes, N. From the data a "phase" diagram as a function of Λ and N is constructed, which depicts the structural motifs favored at different size and quantum parameter. Comparisons of the "quantum induced" structural transitions depicted in the latter are also made with temperature induced transitions and those caused by varying the range of the Morse potential. Following this, the structural properties of binary para-Hydrogen/ ortho-Deuterium clusters are investigated using the VGW approximation and Monte-Carlo methods within the GMIN framework. The latter uses the "Basin-Hopping" algorithm, which simplifies the potential energy landscape, and coupled with the VGW

  16. Materials properties numerical database system established and operational at CINDAS/Purdue University

    NASA Technical Reports Server (NTRS)

    Ho, C. Y.; Li, H. H.

    1989-01-01

    A computerized comprehensive numerical database system on the mechanical, thermophysical, electronic, electrical, magnetic, optical, and other properties of various types of technologically important materials such as metals, alloys, composites, dielectrics, polymers, and ceramics has been established and operational at the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) of Purdue University. This is an on-line, interactive, menu-driven, user-friendly database system. Users can easily search, retrieve, and manipulate the data from the database system without learning special query language, special commands, standardized names of materials, properties, variables, etc. It enables both the direct mode of search/retrieval of data for specified materials, properties, independent variables, etc., and the inverted mode of search/retrieval of candidate materials that meet a set of specified requirements (which is the computer-aided materials selection). It enables also tabular and graphical displays and on-line data manipulations such as units conversion, variables transformation, statistical analysis, etc., of the retrieved data. The development, content, accessibility, etc., of the database system are presented and discussed.

  17. Abasy Atlas: a comprehensive inventory of systems, global network properties and systems-level elements across bacteria.

    PubMed

    Ibarra-Arellano, Miguel A; Campos-González, Adrián I; Treviño-Quintanilla, Luis G; Tauch, Andreas; Freyre-González, Julio A

    2016-01-01

    The availability of databases electronically encoding curated regulatory networks and of high-throughput technologies and methods to discover regulatory interactions provides an invaluable source of data to understand the principles underpinning the organization and evolution of these networks responsible for cellular regulation. Nevertheless, data on these sources never goes beyond the regulon level despite the fact that regulatory networks are complex hierarchical-modular structures still challenging our understanding. This brings the necessity for an inventory of systems across a large range of organisms, a key step to rendering feasible comparative systems biology approaches. In this work, we take the first step towards a global understanding of the regulatory networks organization by making a cartography of the functional architectures of diverse bacteria. Abasy ( A: cross- BA: cteria SY: stems) Atlas provides a comprehensive inventory of annotated functional systems, global network properties and systems-level elements (global regulators, modular genes shaping functional systems, basal machinery genes and intermodular genes) predicted by the natural decomposition approach for reconstructed and meta-curated regulatory networks across a large range of bacteria, including pathogenically and biotechnologically relevant organisms. The meta-curation of regulatory datasets provides the most complete and reliable set of regulatory interactions currently available, which can even be projected into subsets by considering the force or weight of evidence supporting them or the systems that they belong to. Besides, Abasy Atlas provides data enabling large-scale comparative systems biology studies aimed at understanding the common principles and particular lifestyle adaptions of systems across bacteria. Abasy Atlas contains systems and system-level elements for 50 regulatory networks comprising 78 649 regulatory interactions covering 42 bacteria in nine taxa, containing

  18. The effect of the liquid-solid system properties on the interline heat transfer coefficient

    NASA Technical Reports Server (NTRS)

    Wayner, P. C., Jr.

    1977-01-01

    A theoretical procedure to determine the heat transfer characteristics of the interline region of an evaporating meniscus using the macroscopic optical and thermophysical properties of the system is outlined. The analysis is based on the premise that the interline transport processes are controlled by the London-van der Waals forces between condensed phases (solid and liquid). The procedure is used to compare the relative size of the interline heat sink of various systems using a constant heat flux model. This solution demonstrates the importance of the interline heat flow number which is evaluated for various systems. The heat transfer characteristics of the decane-steel system are numerically compared with those of the carbon tetrachloride-quartz system.

  19. Dynamical properties and complexity in fractional-order diffusionless Lorenz system

    NASA Astrophysics Data System (ADS)

    He, Shaobo; Sun, Kehui; Banerjee, Santo

    2016-08-01

    In this paper, dynamics and complexity of the fractional-order diffusionless Lorenz system which is solved by the developed discrete Adomian decomposition method are investigated numerically. Dynamical properties of the fractional-order diffusionless Lorenz system with the control parameter and derivative order varying is analyzed by using bifurcation diagrams, and period-doubling route to chaos in different cases is observed. The complexity of the system is investigated by means of Lyapunov characteristic exponents, multi-scale spectral entropy algorithm and multiscale Renyi permutation entropy algorithm. It can be observed that the three methods illustrate consistent results and the system has rich complex dynamics. Interestingly, complexity decreases with the increase of derivative order. It shows that the fractional-order diffusionless Lorenz system is a good model for real applications such as information encryption and secure communication.

  20. Molecular-Flow Properties of RIB Type Vapor-Transport Systems Using a Fast-Valve

    SciTech Connect

    Alton, Gerald D; Bilheux, Hassina Z; Zhang, Y.; Liu, Yuan

    2014-01-01

    The advent of the fast-valve device, described previously, permits measurement of molecular-flow times of chemically active or inactive gaseous species through radioactive ion beam (RIB) target ion source systems, independent of size, geometry and materials of construction. Thus, decay losses of short-half-life RIBs can be determined for a given target/vapor-transport system in advance of on-line operation, thereby ascertaining the feasibility of the system design for successful processing of a given isotope. In this article, molecular-flow-time theory and experimentally measured molecular-flow time data are given for serial- and parallel-coupled Ta metal RIB vapor-transport systems similar to those used at ISOL based RIB facilities. In addition, the effect of source type on the molecular-flow time properties of a given system is addressed, and a chemical passivation method for negating surface adsorption enthalpies for chemically active gaseous species on Ta surfaces is demonstrated.

  1. Frequency response properties of primary afferent neurons in the posterior lateral line system of larval zebrafish.

    PubMed

    Levi, Rafael; Akanyeti, Otar; Ballo, Aleksander; Liao, James C

    2015-01-15

    The ability of fishes to detect water flow with the neuromasts of their lateral line system depends on the physiology of afferent neurons as well as the hydrodynamic environment. Using larval zebrafish (Danio rerio), we measured the basic response properties of primary afferent neurons to mechanical deflections of individual superficial neuromasts. We used two types of stimulation protocols. First, we used sine wave stimulation to characterize the response properties of the afferent neurons. The average frequency-response curve was flat across stimulation frequencies between 0 and 100 Hz, matching the filtering properties of a displacement detector. Spike rate increased asymptotically with frequency, and phase locking was maximal between 10 and 60 Hz. Second, we used pulse train stimulation to analyze the maximum spike rate capabilities. We found that afferent neurons could generate up to 80 spikes/s and could follow a pulse train stimulation rate of up to 40 pulses/s in a reliable and precise manner. Both sine wave and pulse stimulation protocols indicate that an afferent neuron can maintain their evoked activity for longer durations at low stimulation frequencies than at high frequencies. We found one type of afferent neuron based on spontaneous activity patterns and discovered a correlation between the level of spontaneous and evoked activity. Overall, our results establish the baseline response properties of lateral line primary afferent neurons in larval zebrafish, which is a crucial step in understanding how vertebrate mechanoreceptive systems sense and subsequently process information from the environment. PMID:25355959

  2. Frequency response properties of primary afferent neurons in the posterior lateral line system of larval zebrafish

    PubMed Central

    Levi, Rafael; Akanyeti, Otar; Ballo, Aleksander

    2014-01-01

    The ability of fishes to detect water flow with the neuromasts of their lateral line system depends on the physiology of afferent neurons as well as the hydrodynamic environment. Using larval zebrafish (Danio rerio), we measured the basic response properties of primary afferent neurons to mechanical deflections of individual superficial neuromasts. We used two types of stimulation protocols. First, we used sine wave stimulation to characterize the response properties of the afferent neurons. The average frequency-response curve was flat across stimulation frequencies between 0 and 100 Hz, matching the filtering properties of a displacement detector. Spike rate increased asymptotically with frequency, and phase locking was maximal between 10 and 60 Hz. Second, we used pulse train stimulation to analyze the maximum spike rate capabilities. We found that afferent neurons could generate up to 80 spikes/s and could follow a pulse train stimulation rate of up to 40 pulses/s in a reliable and precise manner. Both sine wave and pulse stimulation protocols indicate that an afferent neuron can maintain their evoked activity for longer durations at low stimulation frequencies than at high frequencies. We found one type of afferent neuron based on spontaneous activity patterns and discovered a correlation between the level of spontaneous and evoked activity. Overall, our results establish the baseline response properties of lateral line primary afferent neurons in larval zebrafish, which is a crucial step in understanding how vertebrate mechanoreceptive systems sense and subsequently process information from the environment. PMID:25355959

  3. Development of a database system for the thermophysical properties of 340 pure fluids

    NASA Astrophysics Data System (ADS)

    Makita, T.; Tanaka, Y.; Takamori, T.; Takaoka, Y.

    1983-12-01

    A new database system was designed and constructed in order to provide the newest and most reliable numerical data on thermophysical properties of fluids to the scientific and technical community as quickly as possible. The database is concerned with 12 kinds of property data: density, specific volume, compressibility factor, vapor pressure, specific heat, specific enthalpy, specific entropy, viscosity, thermal conductivity, surface tension, refractive index, and dielectric constant of 340 pure fluids under all conditions of seven convenient physical states. Only the most probable data, which were critically evaluated in advance, are compiled as functions of temperature and pressure in the form of either numerical data tables or correlation formulas. Property values at desired grid points of temperature and pressure can be obtained in SI units directly or by interpolations with some supplementary information, such as the grade of reliability, source bibliography, and fundamental physical constants of the fluid. The database is usable as conversational processing by TSS, the tabulation of property data in a batch processing, and one of the subroutine libraries in the computation of a user's program. Ten kinds of application programs are prepared for multipurpose retrievals so that anyone can use the database without any special knowledge of the structure or machine languages of this system.

  4. Physiological and regulatory properties of the general amino acid transport system of Neurospora crassa.

    PubMed Central

    DeBusk, R M; DeBusk, A G

    1980-01-01

    The fundamental properties of the general amino acid transport system of Neurospora crassa were investigated in the conidial stage of the life cycle. The transport activity was found to be under genetic control, and an isogenic set of mutants deficient for the neutral, basic, or general amino acid transport systems and combinations thereof was constructed and used for analyzing the properties specific to the general permease. Amino acid transport by this system was found to be a carrier-mediated active process with broad specificity for the neutral and basic amino acids. Kinetic analysis revealed that a common binding site functioned to transport both neutral and basic amino acids and that the permease had a high affinity for its substrates. The kinetic parameters Km, Vmax, and Ki were defined for several substrates. Two modes of regulation were detected: substrate inhibition and ammonium repression. Activity of the general system was enhanced by the removal of ammonium ions from the incubation medium with a concomitant decline in either neutral or basic permease activity, suggesting that a common component exists between the neutral and the general systems and between the basic and the general systems. PMID:6447141

  5. Computer-assisted analyses of the thermodynamic properties of slags in coal-combustion systems

    SciTech Connect

    Blander, M.; Pelton, A.D.

    1983-09-01

    Equations were developed for the analysis of the thermodynamic properties of molten silicate solutions; the equations take into account the unusual concentration and temperature dependence of the solution properties of ordered systems. For binary systems, these equations were coupled with an optimization computer program to analyze all reliable thermodynamic data, including phase diagrams, free energies and enthalpies of formation of compounds, activities of components, enthalpies of mixing, entropies of fusion, miscibility gaps, etc. In this manner, we analyzed data for five binary systems: CaO-SiO/sub 2/, Na/sub 2/O-SiO/sub 2/, CaO-Al/sub 2/O/sub 3/, Na/sub 2/O-Al/sub 2/O/sub 3/, and Al/sub 2/O/sub 3/-SiO/sub 2/. The results of the binary systems were combined, and an analysis done of three ternary systems: CaO-Al/sub 2/O/sub 3/-SiO/sub 2/, Na/sub 2/O-CaO-SiO/sub 2/, and Na/sub 2/O-Al/sub 2/O/sup 3/-SiO/sub 2/. A tentative analysis of the quaternary system, Na/sub 2/O-CaO-Al/sub 2/O/sub 3/-SiO/sub 2/, was also undertaken. 53 references, 51 figures, 3 tables.

  6. 32 CFR 37.605 - What is the general policy on participants' financial, property, and purchasing systems?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...' financial, property, and purchasing systems? 37.605 Section 37.605 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE DoD GRANT AND AGREEMENT REGULATIONS TECHNOLOGY INVESTMENT AGREEMENTS Award Terms Affecting Participants' Financial, Property, and Purchasing Systems § 37.605 What is...

  7. 32 CFR 37.605 - What is the general policy on participants' financial, property, and purchasing systems?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...' financial, property, and purchasing systems? 37.605 Section 37.605 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE DoD GRANT AND AGREEMENT REGULATIONS TECHNOLOGY INVESTMENT AGREEMENTS Award Terms Affecting Participants' Financial, Property, and Purchasing Systems § 37.605 What is...

  8. 26 CFR 1.167(l)-4 - Public utility property; election to use asset depreciation range system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... depreciation range system. 1.167(l)-4 Section 1.167(l)-4 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT... Individuals and Corporations § 1.167(l)-4 Public utility property; election to use asset depreciation range system. (a) Application of section 167(l) to certain property subject to asset depreciation range...

  9. 26 CFR 1.167(l)-4 - Public utility property; election to use asset depreciation range system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... depreciation range system. 1.167(l)-4 Section 1.167(l)-4 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT... Individuals and Corporations § 1.167(l)-4 Public utility property; election to use asset depreciation range system. (a) Application of section 167(l) to certain property subject to asset depreciation range...

  10. 26 CFR 1.167(l)-4 - Public utility property; election to use asset depreciation range system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... depreciation range system. 1.167(l)-4 Section 1.167(l)-4 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT... Individuals and Corporations § 1.167(l)-4 Public utility property; election to use asset depreciation range system. (a) Application of section 167(l) to certain property subject to asset depreciation range...

  11. 26 CFR 1.167(l)-4 - Public utility property; election to use asset depreciation range system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... depreciation range system. 1.167(l)-4 Section 1.167(l)-4 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT... Individuals and Corporations § 1.167(l)-4 Public utility property; election to use asset depreciation range system. (a) Application of section 167(l) to certain property subject to asset depreciation range...

  12. 26 CFR 1.167(l)-4 - Public utility property; election to use asset depreciation range system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... depreciation range system. 1.167(l)-4 Section 1.167(l)-4 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT... Individuals and Corporations § 1.167(l)-4 Public utility property; election to use asset depreciation range system. (a) Application of section 167(l) to certain property subject to asset depreciation range...

  13. Pairing and thermodynamics properties of finite-systems with fixed number of particles

    NASA Astrophysics Data System (ADS)

    Gambacurta, D.; Lacroix, D.

    2012-12-01

    A canonical description of the thermodynamical pairing properties of small systems is achieved by using the Variation After Projection approach at finite temperature. The minimization of the free energy is made by a direct evaluation of the energy and full diagonalization of the entropy. We use the Richardson - pairing model whose exact solution allows to study the reliability of different approaches. We show that the Projection After Variation approach, that is usually performed at zero temperature with rather good success, provides a quite poor description at finite temperature. On the contrary, the Variation After Projection applied at finite temperature provides a perfect reproduction of the exact canonical properties of odd or even systems from very low to high temperature.

  14. Physicochemical characterization and dissolution properties of nimesulide-cyclodextrin binary systems.

    PubMed

    Nalluri, Buchi N; Chowdary, K P R; Murthy, K V R; Hayman, A R; Becket, G

    2003-01-01

    The objective of this work is physicochemical characterization of nimesulide-cyclodextrin binary systems both in solution and solid state and to improve the dissolution properties of nimesulide (N) via complexation with alpha-, beta, and gamma-cyclodextrins (CDs). Detection of inclusion complexation was done in solution by means of phase solubility analysis, mass spectrometry, and 1H nuclear magnetic resonance (1H-NMR) spectroscopic studies, and in solid state using differential scanning calorimetry (DSC), powder x-ray diffractometry (X-RD), scanning electron microscopy (SEM), and in vitro dissolution studies. Phase solubility, mass spectrometry and 1H-NMR studies in solution revealed 1:1 M complexation of N with all CDs. A true inclusion of N with beta-CD at 1:2 M in solid state was confirmed by DSC, powder X-RD and SEM studies. Dissolution properties of N-CD binary systems were superior when compared to pure N. PMID:12916912

  15. Physicochemical characterization and dissolution properties of meloxicam-cyclodextrin binary systems.

    PubMed

    Naidu, N Buchi; Chowdary, K P R; Murthy, K V R; Satyanarayana, V; Hayman, A R; Becket, G

    2004-04-01

    The objective of the work is physicochemical characterization of meloxicam (ME)-cyclodextrin (CD) binary systems both in solution and solid states and to improve the dissolution properties of meloxicam via complexation with alpha-, beta- and gamma-cyclodextrins. Detection of inclusion complexation was done in solution state by means of phase solubility analysis, mass spectrometry and 1H nuclear magnetic resonance (NMR) studies, and in solid state using differential scanning calorimetry (DSC), powder X-ray diffractometry, and in vitro dissolution studies. Phase solubility, mass spectrometry and 1H NMR studies in solution state revealed 1:1M complexation of meloxicam with all CDs. A true inclusion of ME with gamma-CD at 1:1 and 1:2M in solid state was confirmed by DSC, powder XRD and scanning electron microscopy (SEM) studies. Dissolution properties of ME-CDs binary systems were superior when compared to pure ME. PMID:15030882

  16. Influence of viscoelastic property on laser-generated surface acoustic waves in coating-substrate systems

    SciTech Connect

    Sun Hongxiang; Zhang Shuyi; Xu Baiqiang

    2011-04-01

    Taking account of the viscoelasticity of materials, the pulsed laser generation of surface acoustic waves in coating-substrate systems has been investigated quantitatively by using the finite element method. The displacement spectra of the surface acoustic waves have been calculated in frequency domain for different coating-substrate systems, in which the viscoelastic properties of the coatings and substrates are considered separately. Meanwhile, the temporal displacement waveforms have been obtained by applying inverse fast Fourier transforms. The numerical results of the normal surface displacements are presented for different configurations: a single plate, a slow coating on a fast substrate, and a fast coating on a slow substrate. The influences of the viscoelastic properties of the coating and the substrate on the attenuation of the surface acoustic waves have been studied. In addition, the influence of the coating thickness on the attenuation of the surface acoustic waves has been also investigated in detail.

  17. Atomic and global mechanical properties of systems described by the Stillinger-Weber potential.

    PubMed

    Voyiatzis, Evangelos; Böhm, Michael C

    2016-08-17

    Analytical expressions for the stress and elasticity tensors of materials, in which the interactions are described by the Stillinger-Weber potential, are derived in the context of the stress fluctuation formalism. The derived formulas can be used both in Monte Carlo and molecular dynamics simulations. As an example of possible applications, they are employed to calculate the influence of the temperature and system size on the mechanical properties of crystalline cubic boron nitride. The system has been studied by molecular dynamics simulations. The computed mechanical properties are in good agreement with available experimental data and first principle calculations. In the studied crystalline cubic boron nitride system, the employed formalism is of higher accuracy than the 'small-strain' non-equilibrium method. The dominant contributions to the elastic constants stem from the Born and stress fluctuation terms. An increase in the system size reduces the statistical uncertainties in the computation of the mechanical properties. A rise of the temperature leads to a slight increase in the observed uncertainties. The derived expressions for the stress and elasticity tensors are further decomposed into sums of atomic level stress and atomic level elasticity tensors. The developed factorization enables us (i) to quantify the contribution of the various chemical groups, in the case under consideration of the different atoms, to the observed mechanical properties and (ii) to determine the elastic constants with reduced computational uncertainties. The reason is that the exact values of some terms of the proposed factorization can be determined theoretically beforehand. Thus, they can be substituted in the derived formulas leading to an enhanced convergence. PMID:27345739

  18. Atomic and global mechanical properties of systems described by the Stillinger–Weber potential

    NASA Astrophysics Data System (ADS)

    Voyiatzis, Evangelos; Böhm, Michael C.

    2016-08-01

    Analytical expressions for the stress and elasticity tensors of materials, in which the interactions are described by the Stillinger–Weber potential, are derived in the context of the stress fluctuation formalism. The derived formulas can be used both in Monte Carlo and molecular dynamics simulations. As an example of possible applications, they are employed to calculate the influence of the temperature and system size on the mechanical properties of crystalline cubic boron nitride. The system has been studied by molecular dynamics simulations. The computed mechanical properties are in good agreement with available experimental data and first principle calculations. In the studied crystalline cubic boron nitride system, the employed formalism is of higher accuracy than the ‘small-strain’ non-equilibrium method. The dominant contributions to the elastic constants stem from the Born and stress fluctuation terms. An increase in the system size reduces the statistical uncertainties in the computation of the mechanical properties. A rise of the temperature leads to a slight increase in the observed uncertainties. The derived expressions for the stress and elasticity tensors are further decomposed into sums of atomic level stress and atomic level elasticity tensors. The developed factorization enables us (i) to quantify the contribution of the various chemical groups, in the case under consideration of the different atoms, to the observed mechanical properties and (ii) to determine the elastic constants with reduced computational uncertainties. The reason is that the exact values of some terms of the proposed factorization can be determined theoretically beforehand. Thus, they can be substituted in the derived formulas leading to an enhanced convergence.

  19. System and methods to determine and monitor changes in microstructural properties

    DOEpatents

    Turner, Joseph Alan

    2011-05-17

    A system and methods with which changes in microstructure properties such as grain size, grain elongation, texture, and porosity of materials can be determined and monitored over time to assess conditions such as stress and defects. The present invention includes a database of data, wherein a first set of data is used for comparison with a second set of data to determine the conditions of the material microstructure.

  20. [Anti-arrhythmic properties of GABA and GABA-ergic system activators].

    PubMed

    Tiurenkov, I N; Perfilova, V N

    2002-01-01

    Clinical and experimental data available in the literature are summarized, which are indicative of the antiarrhythmogenic properties of GABA and substances possessing GABA-positive activity (phenibut, piracetam, sodium hydroxybutyrate, lithium hydroxybutyrate, etc.). The antiarrhythmic effects are manifested in various cases of the heart rhythm violation. The mechanism of this action is related to activation of the central and peripheral retarding GABAergic system, as well as to antihypoxant, antioxidant, and antistressor effects. PMID:12025796

  1. Effect of defoliant (butiphose) on morpho-physiological properties and enzyme systems of natural membranes.

    PubMed

    Mirakhmedov, A K; Ochilov, K R; Sagatova, G A; Khan, M Z; Khole, V

    1989-03-01

    Butiphose (Tributyltritiophosphate, (C4H9S)3PO) a commonly used defoliant in cotton growing regions of USSR, caused extensive alterations in morphological features of erythrocyte and nuclear membranes and affected the permeability properties of rat liver mitochondrial membrane. It disrupted Ca2+ transport system and other energy dependent processes in mitochondria. A reduction in the activity of cytochrome-c-oxidase and NAD.H-oxidase was also observed. PMID:2606532

  2. Features of the magnetic properties of Co/Si/Co thin-film systems

    NASA Astrophysics Data System (ADS)

    Shalygina, E. E.; Kharlamova, A. M.; Rozhnovskaya, A. A.; Kurlyandskaya, G. V.; Svalov, A. V.

    2013-12-01

    The magnetic properties of Co/Si/Co thin-film structures grown by magnetron sputtering have been studied using magnetooptical techniques. It is established that the saturation field ( H S) of trilayers exhibits oscillations as a function of the thickness of the semiconductor (silicon) interlayer. This behavior is explained by structural features of the Co/Si/Co system and the presence of antiferromagnetic exchange coupling between magnetic layers via the silicon interlayer.

  3. Volume properties of reverse micellar systems AOT/ n-heptane/DMSO-water

    NASA Astrophysics Data System (ADS)

    Sargsyan, A. R.; Shahinyan, G. A.; Markarian, S. A.

    2014-05-01

    The volume properties of reverse micellar systems bis(2-ethylhexyl) sulfosuccinate sodium salt/ n-heptane/dimethyl sulfoxide-water are studied via densitometry. The presence of dimethyl sulfoxide and the increase in its amount in a dimethyl sulfoxide-water mixed solvent raise the apparent volume of the polar phase. This increase is also observed when the degree of hydration of the polar core and the temperature are raised.

  4. Relevance of system size to the steady-state properties of tapped granular systems.

    PubMed

    Gago, Paula A; Maza, Diego; Pugnaloni, Luis A

    2015-03-01

    We investigate the steady-state packing fraction ϕ and force moment tensor Σ of quasi-two-dimensional granular columns subjected to tapping. Systems of different height h and width L are considered. We find that ϕ and Σ, which describe the macroscopic state of the system, are insensitive to L for L>50d (with d the grain diameter). However, results for granular columns of different heights cannot be conciliated. This suggests that comparison between results of different laboratories on this type of experiments can be done only for systems of same height. We show that a parameter ɛ=1+(Aω)2/(2gh), with A and ω the amplitude and frequency of the tap and g the acceleration of gravity, can be defined to characterize the tap intensity. This parameter is based on the effective flight of the granular bed, which takes into account the h dependency. When ϕ is plotted as a function of ɛ, the data collapses for systems of different h. However, this parameter alone is unable to determine the steady state to be reached since different Σ can be observed for a given ɛ if different column heights are considered. PMID:25871103

  5. Soil food web properties explain ecosystem services across European land use systems

    PubMed Central

    de Vries, Franciska T.; Thébault, Elisa; Liiri, Mira; Birkhofer, Klaus; Tsiafouli, Maria A.; Bjørnlund, Lisa; Bracht Jørgensen, Helene; Brady, Mark Vincent; Christensen, Søren; de Ruiter, Peter C.; d’Hertefeldt, Tina; Frouz, Jan; Hedlund, Katarina; Hemerik, Lia; Hol, W. H. Gera; Hotes, Stefan; Mortimer, Simon R.; Setälä, Heikki; Sgardelis, Stefanos P.; Uteseny, Karoline; van der Putten, Wim H.; Wolters, Volkmar; Bardgett, Richard D.

    2013-01-01

    Intensive land use reduces the diversity and abundance of many soil biota, with consequences for the processes that they govern and the ecosystem services that these processes underpin. Relationships between soil biota and ecosystem processes have mostly been found in laboratory experiments and rarely are found in the field. Here, we quantified, across four countries of contrasting climatic and soil conditions in Europe, how differences in soil food web composition resulting from land use systems (intensive wheat rotation, extensive rotation, and permanent grassland) influence the functioning of soils and the ecosystem services that they deliver. Intensive wheat rotation consistently reduced the biomass of all components of the soil food web across all countries. Soil food web properties strongly and consistently predicted processes of C and N cycling across land use systems and geographic locations, and they were a better predictor of these processes than land use. Processes of carbon loss increased with soil food web properties that correlated with soil C content, such as earthworm biomass and fungal/bacterial energy channel ratio, and were greatest in permanent grassland. In contrast, processes of N cycling were explained by soil food web properties independent of land use, such as arbuscular mycorrhizal fungi and bacterial channel biomass. Our quantification of the contribution of soil organisms to processes of C and N cycling across land use systems and geographic locations shows that soil biota need to be included in C and N cycling models and highlights the need to map and conserve soil biodiversity across the world. PMID:23940339

  6. Soil food web properties explain ecosystem services across European land use systems.

    PubMed

    de Vries, Franciska T; Thébault, Elisa; Liiri, Mira; Birkhofer, Klaus; Tsiafouli, Maria A; Bjørnlund, Lisa; Bracht Jørgensen, Helene; Brady, Mark Vincent; Christensen, Søren; de Ruiter, Peter C; d'Hertefeldt, Tina; Frouz, Jan; Hedlund, Katarina; Hemerik, Lia; Hol, W H Gera; Hotes, Stefan; Mortimer, Simon R; Setälä, Heikki; Sgardelis, Stefanos P; Uteseny, Karoline; van der Putten, Wim H; Wolters, Volkmar; Bardgett, Richard D

    2013-08-27

    Intensive land use reduces the diversity and abundance of many soil biota, with consequences for the processes that they govern and the ecosystem services that these processes underpin. Relationships between soil biota and ecosystem processes have mostly been found in laboratory experiments and rarely are found in the field. Here, we quantified, across four countries of contrasting climatic and soil conditions in Europe, how differences in soil food web composition resulting from land use systems (intensive wheat rotation, extensive rotation, and permanent grassland) influence the functioning of soils and the ecosystem services that they deliver. Intensive wheat rotation consistently reduced the biomass of all components of the soil food web across all countries. Soil food web properties strongly and consistently predicted processes of C and N cycling across land use systems and geographic locations, and they were a better predictor of these processes than land use. Processes of carbon loss increased with soil food web properties that correlated with soil C content, such as earthworm biomass and fungal/bacterial energy channel ratio, and were greatest in permanent grassland. In contrast, processes of N cycling were explained by soil food web properties independent of land use, such as arbuscular mycorrhizal fungi and bacterial channel biomass. Our quantification of the contribution of soil organisms to processes of C and N cycling across land use systems and geographic locations shows that soil biota need to be included in C and N cycling models and highlights the need to map and conserve soil biodiversity across the world. PMID:23940339

  7. Participation in Decision Making as a Property of Complex Adaptive Systems: Developing and Testing a Measure

    PubMed Central

    Anderson, Ruth A.; Hsieh, Pi-Ching; Su, Hui Fang; Landerman, Lawrence R.; McDaniel, Reuben R.

    2013-01-01

    Objectives. To (1) describe participation in decision-making as a systems-level property of complex adaptive systems and (2) present empirical evidence of reliability and validity of a corresponding measure. Method. Study 1 was a mail survey of a single respondent (administrators or directors of nursing) in each of 197 nursing homes. Study 2 was a field study using random, proportionally stratified sampling procedure that included 195 organizations with 3,968 respondents. Analysis. In Study 1, we analyzed the data to reduce the number of scale items and establish initial reliability and validity. In Study 2, we strengthened the psychometric test using a large sample. Results. Results demonstrated validity and reliability of the participation in decision-making instrument (PDMI) while measuring participation of workers in two distinct job categories (RNs and CNAs). We established reliability at the organizational level aggregated items scores. We established validity of the multidimensional properties using convergent and discriminant validity and confirmatory factor analysis. Conclusions. Participation in decision making, when modeled as a systems-level property of organization, has multiple dimensions and is more complex than is being traditionally measured. Managers can use this model to form decision teams that maximize the depth and breadth of expertise needed and to foster connection among them. PMID:24349771

  8. A data acquisition system for longitudinal beam properties in a rapid cycling synchrotron

    SciTech Connect

    Steimel, J.; Tan, C.Y.; /Fermilab

    2011-03-01

    A longitudinal beam properties, data acquisition system has been commissioned to operate in the Fermilab booster ring. This system captures real time information including beam synchronous phase, bunch length, and coupled bunch instability amplitudes as the beam is accelerated from 400 MeV to 8 GeV in 33 ms. The system uses an off-the-shelf Tektronix oscilloscope running Labview software and a synchronous pulse generator. This paper describes the hardware configuration and the software configuration used to optimize the data processing rate. The Fermilab Booster is currently pushed to its intensity limit due to the high demand from different experiments for protons. This will continue into the era of the intensity frontier. While intensity is the most critical parameter, emittance must be controlled as well. Longitudinal emittance is an important parameter for optimizing the slip stacking process in the Main Injector. Longitudinal instabilities can spoil the emittance, so it is important to monitor bunch lengths and bunch phase oscillations in the Booster. The Booster presents a special challenge when it comes to measuring beam properties. The acceleration ramp is short (33ms), and the RF frequency varies from 38-52.8 MHz. Standard instrumentation like spectrum analyzers and network analyzers cannot effectively measure beam properties, because they cannot track the changing frequencies. Early instrumentation involved a series of tracking oscillators, mixers, and diode detectors that would require vigilant calibration. There was a demand for a more robust means of gathering beam parameters.

  9. Noncontact single-pulse optical method to measure interfacial properties in intact systems.

    PubMed

    Clark, David C; Kim, Myung K

    2012-12-15

    We introduce a noncontact purely optical approach to measuring the localized surface properties of an interface within a system using a single optical pressure pulse and a time-resolved digital holographic quantitative phase-imaging technique to track the propagating nanometric capillary disturbance. We demonstrate the proposed method's ability to measure the surface energy of deionized water, methanol, and chemical monolayers formed by surfactants with good agreement to published values. The development of this technique boasts immediate application to static and dynamic systems and near-future applications for living biological cell membranes. PMID:23258033

  10. Noise Properties in the Ideal Kirchhoff-Law-Johnson-Noise Secure Communication System

    PubMed Central

    Gingl, Zoltan; Mingesz, Robert

    2014-01-01

    In this paper we determine the noise properties needed for unconditional security for the ideal Kirchhoff-Law-Johnson-Noise (KLJN) secure key distribution system using simple statistical analysis. It has already been shown using physical laws that resistors and Johnson-like noise sources provide unconditional security. However real implementations use artificial noise generators, therefore it is a question if other kind of noise sources and resistor values could be used as well. We answer this question and in the same time we provide a theoretical basis to analyze real systems as well. PMID:24755558

  11. Minimal control synthesis adaptive control of nonlinear systems: utilizing the properties of chaos.

    PubMed

    di Bernardo, M; Stoten, D P

    2006-09-15

    This paper discusses a novel approach to the control of chaos based on the use of the adaptive minimal control synthesis algorithm. The strategies presented are based on the explicit exploitation of different properties of chaotic systems including the boundedness of the chaotic attractors and their topological transitivity (or ergodicity). It is shown that chaos can be exploited to synthesize more efficient control techniques for nonlinear systems. For instance, by using the ergodicity of the chaotic trajectory, we show that a local adaptive control strategy can be used to synthesize a global controller. An application is to the swing-up control of a double inverted pendulum. PMID:16893794

  12. Low frictional property of copper oxide thin films optimised using a combinatorial sputter coating system

    NASA Astrophysics Data System (ADS)

    Goto, Masahiro; Kasahara, Akira; Tosa, Masahiro

    2006-01-01

    A combinatorial sputter coating system has been developed that can optimize the crystal preferred orientation of coating films. With this system, it is possible to synthesize various kinds of coatings whilst precisely controlling conditions such as the sputter gas, the gas pressure, the gas partial pressure, the r.f. power, the substrate temperature, the distance between the substrate and target, etc. In this way, we successfully synthesized copper oxide coatings with different crystal preferred orientations, and low frictional property was obtained by optimizing the crystal preferred orientation.

  13. RIM as the data base management system for a material properties data base

    NASA Technical Reports Server (NTRS)

    Karr, P. H.; Wilson, D. J.

    1984-01-01

    Relational Information Management (RIM) was selected as the data base management system for a prototype engineering materials data base. The data base provides a central repository for engineering material properties data, which facilitates their control. Numerous RIM capabilities are exploited to satisfy prototype data base requirements. Numerical, text, tabular, and graphical data and references are being stored for five material types. Data retrieval will be accomplished both interactively and through a FORTRAN interface. The experience gained in creating and exercising the prototype will be used in specifying requirements for a production system.

  14. Conservation properties of numerical integration methods for systems of ordinary differential equations

    NASA Technical Reports Server (NTRS)

    Rosenbaum, J. S.

    1976-01-01

    If a system of ordinary differential equations represents a property conserving system that can be expressed linearly (e.g., conservation of mass), it is then desirable that the numerical integration method used conserve the same quantity. It is shown that both linear multistep methods and Runge-Kutta methods are 'conservative' and that Newton-type methods used to solve the implicit equations preserve the inherent conservation of the numerical method. It is further shown that a method used by several authors is not conservative.

  15. The study of data collection method for the plasma properties collection and evaluation system from web

    NASA Astrophysics Data System (ADS)

    Park, Jun-Hyoung; Song, Mi-Young; Plasma Fundamental Technology Research Team

    2015-09-01

    Plasma databases are necessarily required to compute the plasma parameters and high reliable databases are closely related with accuracy enhancement of simulations. Therefore, a major concern of plasma properties collection and evaluation system is to create a sustainable and useful research environment for plasma data. The system has a commitment to provide not only numerical data but also bibliographic data (including DOI information). Originally, our collection data methods were done by manual data search. In some cases, it took a long time to find data. We will be find data more automatically and quickly than legacy methods by crawling or search engine such as Lucene.

  16. Evaluation of optical and chromatic properties under electrical and thermal coupling in solid state lighting systems

    NASA Astrophysics Data System (ADS)

    Fu, Han-Kuei; Peng, Yi-Ping; Wang, Chien-Ping; Chiang, Hsin-Chien; Chen, Tzung-Te; Chen, Chiu-Ling; Chou, Pei-Ting

    2013-09-01

    For energy-saving, high efficiency and low pollution, the lighting of LED systems is important for the future of green energy technology industry. The solid state lighting becomes the replacement of traditional lighting, such as, light bulbs and compact fluorescent lamps. Because of the semiconductor characteristics, the luminous efficiency of LEDs is sensitive to the operating temperature. Besides increasing the luminous efficiency, effective controlling electricity and thermal characteristics in the design of LED lighting products is the key point to achieve the best results. LED modules can be combined with multi-grain process or through a combination of multiple LED chips. Accurate analysis of this LED module for the electrical, thermal characteristics and high reliability is the critical knowledge of modular design. In this report, we studied the electrical and thermal coupling phenomenon in solid state lighting systems to analyze their reliability. By experiments and simulations, we obtained the apparent variation of temperature distribution of LED system due to differences of their forward voltages and thermal resistances. These events may reduce their reliability. Besides, the evaluation of optical and chromatic properties was based on the variation of temperature distribution and current of LED system. This is the key technology to predict the optical and chromatic properties of LED system in use.

  17. Stability and dynamical properties of material flow systems on random networks

    NASA Astrophysics Data System (ADS)

    Anand, K.; Galla, T.

    2009-04-01

    The theory of complex networks and of disordered systems is used to study the stability and dynamical properties of a simple model of material flow networks defined on random graphs. In particular we address instabilities that are characteristic of flow networks in economic, ecological and biological systems. Based on results from random matrix theory, we work out the phase diagram of such systems defined on extensively connected random graphs, and study in detail how the choice of control policies and the network structure affects stability. We also present results for more complex topologies of the underlying graph, focussing on finitely connected Erdös-Réyni graphs, Small-World Networks and Barabási-Albert scale-free networks. Results indicate that variability of input-output matrix elements, and random structures of the underlying graph tend to make the system less stable, while fast price dynamics or strong responsiveness to stock accumulation promote stability.

  18. VizieR Online Data Catalog: Properties of Kepler multi-planet candidate systems (Wang+, 2014)

    NASA Astrophysics Data System (ADS)

    Wang, J.; Xie, J.-W.; Barclay, T.; Fischer, D. A.

    2016-05-01

    Our sample consists of bright host stars with multi-planet transiting systems from Kepler. Out of 5779 Kepler Objects of Interest (http://exoplanetarchive.ipac.caltech.edu/), we selected all the systems with a Kepler magnitude (KP) brighter than 13.5mag and with at least two planet candidates. The sample includes 343 planet candidates (see Table3) in 138 multi-planet candidate systems (see Table2) from the Kepler mission. For these systems, we used archival data from Kepler to characterize their stellar (see Table2) and orbital properties (see Table3). We used UKIRT images to calculate brightness contrast curves and to detect stellar companions around planet candidate host stars (see Table4). (3 data files).

  19. The DIGISOIL multi-sensor system: from geophysical measurements to soil properties.

    NASA Astrophysics Data System (ADS)

    Grandjean, Gilles

    2010-05-01

    The purposes of the multidisciplinary DIGISOIL project are the integration and improvement of in situ and proximal measurement technologies for the assessment of soil properties and soil degradation indicators, going from the sensing technologies to their integration and their application in (digital) soil mapping (DSM). In order to assess and prevent soil degradation and to benefit from the different ecological, economical and historical functions of the soil in a sustainable way, high resolution and quantitative maps of soil properties are needed. The core objective of the project is to explore and exploit new capabilities of advanced geophysical technologies for answering this societal demand. To this aim, DIGISOIL addresses four issues covering technological, soil science and economic aspects: (i) the validation of geophysical (in situ, proximal and airborne) technologies and integrated pedo-geophysical inversion techniques (mechanistic data fusion) (ii) the relation between the geophysical parameters and the soil properties, (iii) the integration of the derived soil properties for mapping soil functions and soil threats, (iv) the pre-evaluation, standardisation and sub-industrialization of the proposed methodologies, including technical and economical studies related to the societal demand. With respect to these issues, the preliminary tasks of the DIGISOIL project were to develop, test and validate the most relevant geophysical technologies for mapping soil properties. The different field tests, realized at this time, allow focusing on technological suitable solutions for each of the identified methods: geoelectric, GPR, EMI, seismics, magnetic and hyperspectral. After data acquisition systems, sensor geometry, and advanced data processing techniques have been developed and validated, we present now the solutions for going from such data to soil properties maps.

  20. Rheological Properties of Silica Nanoparticles in Brine and Brine-Surfactant Systems

    NASA Astrophysics Data System (ADS)

    Pales, Ashley; Kinsey, Erin; Li, Chunyan; Mu, Linlin; Bai, Lingyun; Clifford, Heather; Darnault, Christophe

    2016-04-01

    Rheological Properties of Silica Nanoparticles in Brine and Brine-Surfactant Systems Ashley R. Pales, Erin Kinsey, Chunyan Li, Linlin Mu, Lingyun Bai, Heather Clifford, and Christophe J. G. Darnault Department of Environmental Engineering and Earth Sciences, Laboratory of Hydrogeoscience and Biological Engineering, L.G. Rich Environmental Laboratory, Clemson University, Clemson, SC, USA Nanofluids are suspensions of nanometer sized particles in any fluid base, where the nanoparticles effect the properties of the fluid base. Commonly, nanofluids are water based, however, other bases such as ethylene-glycol, glycerol, and propylene-glycol, have been researched to understand the rheological properties of the nanofluids. This work aims to understand the fundamental rheological properties of silica nanoparticles in brine based and brine-surfactant based nanofluids with temperature variations. This was done by using variable weight percent of silica nanoparticles from 0.001% to 0.1%. Five percent brine was used to create the brine based nanofluids; and 5% brine with 2CMC of Tween 20 nonionic surfactant (Sigma-Aldrich) was used to create the brine-surfactant nanofluid. Rheological behaviors, such as shear rate, shear stress, and viscosity, were compared between these nanofluids at 20C and at 60C across the varied nanoparticle wt%. The goal of this work is to provide a fundamental basis for future applied testing for enhanced oil recovery. It is hypothesized that the addition of surfactant will have a positive impact on nanofluid properties that will be useful for enhance oil recovery. Differences have been observed in preliminary data analysis of the rheological properties between these two nanofluids indicating that the surfactant is having the hypothesized effect.

  1. Physics of Life: A Model for Non-Newtonian Properties of Living Systems

    NASA Technical Reports Server (NTRS)

    Zak, Michail

    2010-01-01

    This innovation proposes the reconciliation of the evolution of life with the second law of thermodynamics via the introduction of the First Principle for modeling behavior of living systems. The structure of the model is quantum-inspired: it acquires the topology of the Madelung equation in which the quantum potential is replaced with the information potential. As a result, the model captures the most fundamental property of life: the progressive evolution; i.e. the ability to evolve from disorder to order without any external interference. The mathematical structure of the model can be obtained from the Newtonian equations of motion (representing the motor dynamics) coupled with the corresponding Liouville equation (representing the mental dynamics) via information forces. All these specific non-Newtonian properties equip the model with the levels of complexity that matches the complexity of life, and that makes the model applicable for description of behaviors of ecological, social, and economical systems. Rather than addressing the six aspects of life (organization, metabolism, growth, adaptation, response to stimuli, and reproduction), this work focuses only on biosignature ; i.e. the mechanical invariants of life, and in particular, the geometry and kinematics of behavior of living things. Living things obey the First Principles of Newtonian mechanics. One main objective of this model is to extend the First Principles of classical physics to include phenomenological behavior on living systems; to develop a new mathematical formalism within the framework of classical dynamics that would allow one to capture the specific properties of natural or artificial living systems such as formation of the collective mind based upon abstract images of the selves and non-selves; exploitation of this collective mind for communications and predictions of future expected characteristics of evolution; and for making decisions and implementing the corresponding corrections if

  2. Contrasting Inherent Optical Properties and Carbon Metabolism Between Five Northeastern (USA) Estuary-plume Systems

    NASA Technical Reports Server (NTRS)

    Vandemark, Doug; Salisbury, Joe; Hunt, Chris; McGillis, Wade R.

    2004-01-01

    We have recently developed the ability to rapidly assess Surface inherent optical properties (IOP), oxygen concentration and pCO2 in estuarine-plume systems using flow-through instrumentation. During the summer of 2004, several estuarine-plume systems were surveyed which include the Pleasant (ME), Penobscot (ME), Kennebec-Androscoggin (ME), Merrimack (NH-MA) and Hudson (NY). Continuous measurements of surface chlorophyll and colored dissolved organic carbon (CDOM) fluorescence, beam attenuation, temperature, salinity, oxygen and pC02 were taken at each system along a salinity gradient from fresh water to near oceanic endmembers. CTD and IOP profiles were also taken at predetermined surface salinity intervals. These were accompanied by discrete determinations of chlorophyll (HPLC and fluorometric), total suspended solids (TSS), dissolved organic carbon (DOC) and alkalinity. IOP data were calibrated using chlorophyll, DOC and TSS data to enable the retrieval of these constituents from IOP data. Considerable differences in the data sets were observed between systems. These ranged from the DOC-enriched, strongly heterotrophic Pleasant River System to the high-chlorophyll autotrophic Merrimack River System. Using pCO2 and oxygen saturation measurements as proxies for water column metabolism, distinct relationships were found between trophic status and inherent optical properties. The nature of these relationships varies between systems and is likely a function of watershed and estuarine attributes including carbon and nutrient loading, in-situ production and related autochthonous inputs of DOC and alkalinity. Our results suggest that IOP data may contain significant information about the trophic status of estuarine and plume systems.

  3. First results of the DIGISOIL multi-sensor system for mapping soil properties

    NASA Astrophysics Data System (ADS)

    Grandjean, G.

    2009-04-01

    The purposes of the multidisciplinary DIGISOIL project are the integration and improvement of in situ and proximal measurement technologies for the assessment of soil properties and soil degradation indicators, going from the sensing technologies to their integration and their application in (digital) soil mapping (DSM). In order to assess and prevent soil degradation and to benefit from the different ecological, economical and historical functions of the soil in a sustainable way, high resolution and accurate maps of soil properties are needed. The core objective of the project is to explore and exploit new capabilities of advanced geophysical technologies for answering this societal demand. To this aim, DIGISOIL addresses four issues covering technological, soil science and economic aspects (Figure 1): (i) the validation of geophysical (in situ, proximal and airborne) technologies and integrated pedo-geophysical inversion techniques (mechanistic data fusion) (ii) the relation between the geophysical parameters and the soil properties, (iii) the integration of the derived soil properties for mapping soil functions and soil threats, (iv) the evaluation, standardisation and sub-industrialization of the proposed methodologies, including technical and economical studies. With respect to these issues, the preliminary tasks of the DIGISOIL project were to develop, test and validate the most relevant geophysical technologies for mapping soil properties. The different field tests, realized at this time, allow focusing on technological suitable solutions for each of identified methods: geoelectric, GPR, seismics, magnetic and hyperspectral. Data acquisition systems, sensor geometry, data processing are thus presented and discussed in the perspectives of producing information layers for Digital Soil Mapping. Next tasks will be dedicated to (i) establish correlations between the measured geophysical measurements and the soil properties involved in soil functions / threats

  4. The boron oxide{endash}boric acid system: Nanoscale mechanical and wear properties

    SciTech Connect

    Ma, X.; Unertl, W.N.; Erdemir, A.

    1999-08-01

    The film that forms spontaneously when boron oxide (B{sub 2}O{sub 3}) is exposed to humid air is a solid lubricant. This film is usually assumed to be boric acid (H{sub 3}BO{sub 3}), the stable bulk phase. We describe the nanometer-scale surface morphology, mechanical properties, and tribological properties of these films and compare them with crystals precipitated from saturated solutions of boric acid. Scanning force microscopy (SFM) and low-load indentation were the primary experimental tools. Mechanical properties and their variation with depth are reported. In all cases, the surfaces were covered with a layer that has different mechanical properties than the underlying bulk. The films formed on boron oxide showed no evidence of crystalline structure. A thin surface layer was rapidly removed, followed by slower wear of the underlying film. The thickness of this initial layer was sensitive to sample preparation conditions, including humidity. Friction on the worn surface was lower than on the as-formed surface in all cases. In contrast, the SFM tip was unable to cause any wear to the surface film on the precipitated crystals. Indentation pop-in features were common for precipitated crystals but did not occur on the films formed on boron oxide. The surface structures were more complex than assumed in models put forth previously to explain the mechanism of lubricity in the boron oxide{endash}boric acid{endash}water system. {copyright} {ital 1999 Materials Research Society.}

  5. Development and characterization of naproxen-chitosan solid systems with improved drug dissolution properties.

    PubMed

    Mura, Paola; Zerrouk, Naima; Mennini, Natascia; Maestrelli, Francesca; Chemtob, Chantal

    2003-05-01

    The solubilizing and amorphizing properties toward naproxen (a poorly water-soluble antiinflammatory drug) of chitosan, an emerging pharmaceutical biopolymer, have been investigated. Solid binary systems at different drug/polymer ratios have been prepared according to different techniques (mixing, cogrinding, kneading, coevaporation) using chitosan at low (CS-L(w)) and medium (CS-M(w)) molecular weight, and tested for dissolution properties. Drug-carrier interactions were investigated in both the liquid and solid state, by phase solubility analysis, differential scanning calorimetry, X-ray powder diffractometry, FT-IR spectroscopy, and scanning electron microscopy. Drug dissolution parameters improved with increasing the polymer amount in the mixture, reaching the highest values at the 1:9 (w/w) drug/polymer ratio, and CS-L(w) was more efficacious than CS-M(w). Cogrinding was the most effective technique, showing the strongest amorphizing effect toward the drug and enabling an increase of more than ten times its relative dissolution rate. Coground mixtures at 3:7 (w/w) drug/polymer ratio were able to give directly compressed tablets which maintained unchanged the improved drug dissolution properties. Enhancer dissolution properties combined with its direct compression feasibility and antiulcerogenic action make CS-L(w) an optimal carrier for developing fast-release oral solid dosage forms of naproxen. PMID:12729863

  6. Mechanical properties of polymer/carbon nanotube composite micro-electromechanical systems bridges

    NASA Astrophysics Data System (ADS)

    Sousa, P. M.; Chu, V.; Conde, J. P.

    2013-04-01

    Microelectromechanical systems with all-polymer structural layers are expected to allow novel MEMS applications due to their mechanical, optical, electronic, and chemical properties, which are tunable and distinct from the standard inorganic layers currently used. The mechanical properties of micro-electromechanical bridge resonators (pMEMS) based on a polymer/carbon-nanotubes (CNT) composite structural material are presented. The structural material of the electrostatically actuated pMEMS microresonators are multilayers of a conductive polymer based on poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) to which carboxylated multi-wall CNTs monolayers are electrostatically attached after surface functionalization. The effects of measurement pressure, temperature, and applied load on the resonance frequency and on the quality factor, Q, of the pMEMS are studied. The long term reliability of the pMEMS resonators is also investigated, and the resonators were subjected to above 1011 actuation cycles without significant performance deterioration. The mechanical properties of the pMEMS are systematically compared to those of a doped hydrogenated amorphous silicon (n+-a-Si:H) MEMS. While the CNT multilayers increase the rigidity (and hence the resonance frequency) as well as the electrical conductivity of the structural layer, they decrease the energy dissipation (and hence increase Q). Changes in CNT-polymer matrix adhesion result in reversible changes of the resonator properties during operation, requiring monitoring and control.

  7. 4d electron Ruthenate systems: their unique and new magnetic properties

    NASA Astrophysics Data System (ADS)

    Lee, Seungran; Shin, Yeongjae; Anwar, M. S.; Sugimoto, Yusuke; Lee, Mincheol; Kang, Sungjin; Yonezawa, Shingo; Maeno, Yoshiteru; Noh, Taewon

    The Ruddlesden-Popper series (PR) of Srn+1RunO3n+1 has attract much interest of their unique physical properties. Among them, SrRuO3 (n = ∞) (SRO) is the only ferromagnetic metallic oxide especially in Ru 4d transition metal oxides. Bulk SRO has orthorhombic structure showing the Curie temperature (TC) ~ 160 K. It is well known that RuO6 octahedral distortion plays critical roles in its mangetic properties. In film systems, such RuO6 octahedra can be easily controlled by strain-engineering. In this talk, with high quality SRO films fully strained (-1.7%-1%) using various substrates, we systematically studied their structural changes and associated magnetic properties. Compared to theoretical predictions, the structural changes can be explained, while the magnetic property changes cannot be understood. Surprisingly, when SRO113 is grown on its PR series of Sr2RuO4 (n=1) (SRO214) single crystal, the exact substrate of SRO214 magnetization results in strongly enhanced magnetization (M > 3 μB/Ru, TC ~ 160 K), which has never found SRO113 (001) since the low-spin configuration of SRO113 prevent M never exceed 2 μB/Ru. The mystery of M in SRO113 (especially SRO113/SRO214) will be further discussed.

  8. Thermophysical and heat transfer properties of phase change material candidate for waste heat transportation system

    NASA Astrophysics Data System (ADS)

    Kaizawa, Akihide; Maruoka, Nobuhiro; Kawai, Atsushi; Kamano, Hiroomi; Jozuka, Tetsuji; Senda, Takeshi; Akiyama, Tomohiro

    2008-05-01

    A waste heat transportation system trans-heat (TH) system is quite attractive that uses the latent heat of a phase change material (PCM). The purpose of this paper is to study the thermophysical properties of various sugars and sodium acetate trihydrate (SAT) as PCMs for a practical TH system and the heat transfer property between PCM selected and heat transfer oil, by using differential scanning calorimetry (DSC), thermogravimetry-differential thermal analysis (TG-DTA) and a heat storage tube. As a result, erythritol, with a large latent heat of 344 kJ/kg at melting point of 117°C, high decomposition point of 160°C and excellent chemical stability under repeated phase change cycles was found to be the best PCM among them for the practical TH system. In the heat release experiments between liquid erythritol and flowing cold oil, we observed foaming phenomena of encapsulated oil, in which oil droplet was coated by solidification of PCM.

  9. Physical Properties and Evolution of the Eclipsing Binary System XZ Canis Minoris

    NASA Astrophysics Data System (ADS)

    Poochaum, R.; Komonjinda, S.; Soonthornthum, B.; Rattanasoon, S.

    2010-07-01

    This research aims to study the eclipse binary system so that its physical properties and evolution can be determined and used as an example to teach high school astronomy. The study of an eclipsing binary system XZ Canis Minoris (XZ CMi) was done at Sirindhorn Observatory, Chiang Mai University using a 0.5-meter reflecting telescope with CCD photometric system (2184×1417 pixel) in B V and R bands of UVB System. The data obtained were used to construct the light curve for each wavelength band and to compute the times of its light minima. New elements were derived using observations with linear to all available minima. As a result, linear ephemeris is HDJmin I = .578 808 948+/-0.000 000 121+2450 515.321 26+/-0.001 07 E, and the new orbital period of XZ CMi is 0.578 808 948+/-0.000 000 121 day. The values obtained were used with the previously published times of minima to get O-C curve of XZ CMi. The result revealed that the orbital period of XZ CMi is continuously decreased at a rate of 0.007 31+/-0.000 57 sec/year. This result indicates that the binary stars are moving closer continuously. From the O-C residuals, there is significant change to indicate the existence of the third body or magnetic activity cycle on the star. However, further analysis of the physical properties of XZ CMi is required.

  10. Hopping Conduction and Bacteria: Transport Properties of Disordered Reaction-Diffusion Systems

    NASA Astrophysics Data System (ADS)

    Missel, Andrew; Dahmen, Karin

    2008-03-01

    Reaction-diffusion (RD) systems are used to model everything from the formation of animal coat patterns to the spread of genes in a population to the seasonal variation of plankton density in the ocean. In all of these problems, disorder plays a large role, but determining its effects on transport properties in RD systems has been a challenge. We present here both analytical and numerical studies of a particular disordered RD system consisting of particles which are allowed to diffuse and compete for resources (2A->A) with spatially homogeneous rates, reproduce (A->2A) in certain areas (``oases''), and die (A->0) everywhere else (the ``desert''). In the low oasis density regime, transport is mediated through rare ``hopping events'' in which a small number of particles diffuse through the desert from one oasis to another; the situation is mathematically analogous to hopping conduction in doped semiconductors, and this analogy, along with some ideas from first passage percolation theory, allows us to make some quantitative predictions about the transport properties of the system on a large scale.

  11. Influence of the Ageing Process on the Resistive and Reactive Properties of the Respiratory System

    PubMed Central

    e Tramont, Caio Vinicius Villalón; Faria, Alvaro Camilo Dias; Lopes, Agnaldo José; Jansen, José Manoel; de Melo, Pedro Lopes

    2009-01-01

    INTRODUCTION In an increasingly old society, the study of the respiratory system changes and new techniques dedicated to older patients are of interest in physiologic studies as well as in the diagnosis of respiratory diseases. OBJECTIVES (1) To investigate the impact of ageing on the resistive and reactive properties of the respiratory system, and (2) to compare the easiness of accomplishment of spirometry and forced oscillation for assessing lung function. METHODS We conducted a cross-sectional study in which forced oscillation was used to investigate respiratory system resistive and reactive properties, while spirometry was used as a reference test to evaluate 80 normal subjects aged between 20 and 86 years. A questionnaire was used to evaluate the easiness of accomplishment of spirometry and forced oscillation. RESULTS There was a significant increase in the respiratory system resonance frequency (p<0.003) and a reduction in the mean reactance (p<0.004) with increasing age. Respiratory system resistance and dynamic compliance were not related to the ageing process. The easiness of accomplishment of forced oscillation measurements was greater than that of spirometry. This result was particularly relevant in subjects over 70 years old (p<0.05). CONCLUSIONS Respiratory system resistance and dynamic compliance are not modified with ageing. On the other hand, respiratory system homogeneity decreases during the ageing process. Forced oscillation is easy to perform and provides information complementary to spirometry. This technique may be a promising alternative and/or complement to other conventional exams used to evaluate older people who are unable to adequately perform spirometric tests. PMID:19936180

  12. Magnetic properties of nanomagnetic and biomagnetic systems analyzed using cantilever magnetometry.

    PubMed

    Gysin, Urs; Rast, Simon; Aste, Andreas; Speliotis, Thanassis; Werle, Christoph; Meyer, Ernst

    2011-07-15

    Magnetic properties of nanomagnetic and biomagnetic systems are investigated using cantilever magnetometry. In the presence of a magnetic field, magnetic films or particles deposited at the free end of a cantilever give rise to a torque on the mechanical sensor, which leads to frequency shifts depending on the applied magnetic field. From the frequency response, the magnetic properties of a magnetic sample are obtained. The magnetic field dependences of paramagnetic and ferromagnetic thin films and particles are measured in a temperature range of 5-320 K at a pressure below 10(-6) mbar. We present magnetic properties of the ferromagnetic materials Fe, Co and Ni at room temperature and also for the rare earth elements Gd, Dy and Tb at various temperatures. In addition, the magnetic moments of magnetotactic bacteria are measured under vacuum conditions at room temperature. Cantilever magnetometry is a highly sensitive tool for characterizing systems with small magnetic moments. By reducing the cantilever dimensions the sensitivity can be increased by an order of magnitude. PMID:21659684

  13. An active microwave imaging system for reconstruction of 2-D electrical property distributions.

    PubMed

    Meaney, P M; Paulsen, K D; Hartov, A; Crane, R K

    1995-10-01

    The goal of this work is to develop a microwave-based imaging system for hyperthermia treatment monitoring and assessment. Toward this end, a four transmit channel and four receive channel hardware device and concomitant image reconstruction algorithm have been realized. The hardware is designed to measure electric fields (i.e., amplitude and phase) at various locations in a phantom tank with and without the presence of various heterogeneities using standard heterodyning principles. Particular attention has been paid to designing a receiver with better than 115 dB of linear dynamic range which is necessary for imaging biological tissue which often has very high conductivity, especially for tissues with high water content. A calibration procedure has been developed to compensate for signal loss due to three-dimensional radiation in the measured data, since the reconstruction process is only two-dimensional at the present time. Results are shown which demonstrate the stability and accuracy of the measurement system, the extent to which the forward computational model agrees with the measured field distribution when the electrical properties are known, and image reconstructions of electrically unknown targets of varying diameter. In the latter case, images of both the reactive and resistive component of the electrical property distribution have been recoverable. Quantitative information on object location, size, and electrical properties results when the target is approximately one-half wavelength in size. Images of smaller objects lack the same level of quantitative information, but remain qualitatively correct. PMID:8582719

  14. A comparative study of constant-order and variable-order fractional models in characterizing memory property of systems

    NASA Astrophysics Data System (ADS)

    Sun, H. G.; Chen, W.; Wei, H.; Chen, Y. Q.

    2011-03-01

    How to characterize the memory property of systems is a challenging issue in the modeling and analysis of complex systems. This study makes a comparative investigation of integer-order derivative, constant-order fractional derivative and two types of variable-order fractional derivatives in characterizing the memory property of systems. The advantages and potential applications of two variable-order derivative definitions are highlighted through a comparative analysis of anomalous relaxation process.

  15. Foaming Properties of Whey Protein Isolate and λ-Carrageenan Mixed Systems.

    PubMed

    Wang, Zhengshan; Zhang, Sha; Vardhanabhuti, Bongkosh

    2015-08-01

    Heating protein with polysaccharide under neutral or near neutral pH can induce the formation of soluble complex with improved functional properties. The objective of our research was to investigate the effects of λ-carrageenan (λC) concentrations and pH on foaming properties of heated whey protein isolate (WPI) and λC soluble complex (h-cpx) in comparison to heated WPI with added λC (pWPI-λC), and unheated WPI with λC (WPI-λC). In all 3 WPI-λC systems at pH 7, increasing λC concentration led to improved foamability until a certain concentration before it decreased. Despite their higher viscosity, both heated systems (pWPI-λC and h-cpx) showed significantly better foamability and foam stability compared to WPI-λC. Rheological results of foams with 0.25% λC suggested that higher elasticity and viscous films were produced in h-cpx and pWPI-λC systems corresponding to better foam stability. Foam microstructure images indicated that foams produced from h-cpx had thicker film and consisted of smaller initial bubble area and more uniform bubble size. Results from the effect of pH (6.2, 6.5, and 7.0) further confirmed that stronger interactions between WPI and λC during heating contributed to the improved foaming properties. Foam stability was higher in h-cpx system at all 3 pH levels, especially under pH 6.2 where there were strongest interactions between the biopolymers. PMID:26121991

  16. HOST STAR PROPERTIES AND TRANSIT EXCLUSION FOR THE HD 38529 PLANETARY SYSTEM

    SciTech Connect

    Henry, Gregory W.; Kane, Stephen R.; Von Braun, Kaspar; Ciardi, David R.; Hinkel, Natalie R.; Wang, Sharon X.; Wright, Jason T.; Mahadevan, Suvrath; Pilyavsky, Genady; Boyajian, Tabetha S.; Fischer, Debra A.; Dragomir, Diana; Farrington, Chris; Howard, Andrew W.; Jensen, Eric; Laughlin, Gregory

    2013-05-10

    The transit signature of exoplanets provides an avenue through which characterization of exoplanetary properties may be undertaken, such as studies of mean density, structure, and atmospheric composition. The Transit Ephemeris Refinement and Monitoring Survey is a program to expand the catalog of transiting planets around bright host stars by refining the orbits of known planets discovered with the radial velocity technique. Here we present results for the HD 38529 system. We determine fundamental properties of the host star through direct interferometric measurements of the radius and through spectroscopic analysis. We provide new radial velocity measurements that are used to improve the Keplerian solution for the two known planets, and we find no evidence for a previously postulated third planet. We also present 12 years of precision robotic photometry of HD 38529 that demonstrate the inner planet does not transit and the host star exhibits cyclic variations in seasonal mean brightness with a timescale of approximately six years.

  17. Properties of a Formal Method for Prediction of Emergent Behaviors in Swarm-based Systems

    NASA Technical Reports Server (NTRS)

    Rouff, Christopher; Vanderbilt, Amy; Hinchey, Mike; Truszkowski, Walt; Rash, James

    2004-01-01

    Autonomous intelligent swarms of satellites are being proposed for NASA missions that have complex behaviors and interactions. The emergent properties of swarms make these missions powerful, but at the same time more difficult to design and assure that proper behaviors will emerge. This paper gives the results of research into formal methods techniques for verification and validation of NASA swarm-based missions. Multiple formal methods were evaluated to determine their effectiveness in modeling and assuring the behavior of swarms of spacecraft. The NASA ANTS mission was used as an example of swarm intelligence for which to apply the formal methods. This paper will give the evaluation of these formal methods and give partial specifications of the ANTS mission using four selected methods. We then give an evaluation of the methods and the needed properties of a formal method for effective specification and prediction of emergent behavior in swarm-based systems.

  18. An airjet actuator system for identification of the human arm joint mechanical properties.

    PubMed

    Xu YMj; Hunter, I W; Hollerbach, J M; Bennett, D J

    1991-11-01

    A system is described for determining the mechanical properties of the human arm during unconstrained posture and movement. An airjet perturbation device is attached to the wrist with a special cuff, and provides high-frequency stochastic perturbations in potentially three orthogonal directions. The airjet operates as a fluidic flip-flop utilizing the Coanda effect, and generates binary force sequences with a steady-state thrust of 4 N, a flat frequency response to 75 Hz, usable thrust to 150 Hz, and a rise time of 1 ms, when the static pressure at the nozzle inlet is 5.5 x 10(5) Pa (80 psi). These operating characteristics are adequate to identify the arm's mechanical properties efficiently and robustly. PMID:1748446

  19. Statistical distribution of mechanical properties for three graphite-epoxy material systems

    NASA Technical Reports Server (NTRS)

    Reese, C.; Sorem, J., Jr.

    1981-01-01

    Graphite-epoxy composites are playing an increasing role as viable alternative materials in structural applications necessitating thorough investigation into the predictability and reproducibility of their material strength properties. This investigation was concerned with tension, compression, and short beam shear coupon testing of large samples from three different material suppliers to determine their statistical strength behavior. Statistical results indicate that a two Parameter Weibull distribution model provides better overall characterization of material behavior for the graphite-epoxy systems tested than does the standard Normal distribution model that is employed for most design work. While either a Weibull or Normal distribution model provides adequate predictions for average strength values, the Weibull model provides better characterization in the lower tail region where the predictions are of maximum design interest. The two sets of the same material were found to have essentially the same material properties, and indicate that repeatability can be achieved.

  20. Fano effect dominance over Coulomb blockade in transport properties of parallel coupled quantum dot system

    SciTech Connect

    Brogi, Bharat Bhushan Ahluwalia, P. K.; Chand, Shyam

    2015-06-24

    Theoretical study of the Coulomb blockade effect on transport properties (Transmission Probability and I-V characteristics) for varied configuration of coupled quantum dot system has been studied by using Non Equilibrium Green Function(NEGF) formalism and Equation of Motion(EOM) method in the presence of magnetic flux. The self consistent approach and intra-dot Coulomb interaction is being taken into account. As the key parameters of the coupled quantum dot system such as dot-lead coupling, inter-dot tunneling and magnetic flux threading through the system can be tuned, the effect of asymmetry parameter and magnetic flux on this tuning is being explored in Coulomb blockade regime. The presence of the Coulomb blockade due to on-dot Coulomb interaction decreases the width of transmission peak at energy level ε + U and by adjusting the magnetic flux the swapping effect in the Fano peaks in asymmetric and symmetric parallel configuration sustains despite strong Coulomb blockade effect.

  1. Complexity methods used in the study of some real systems with weak characteristic properties

    NASA Astrophysics Data System (ADS)

    Prenga, Dode; Ifti, Margarita

    2016-03-01

    Tsallis statistical analysis and other possible use of q-functions are considered here in the study of some real systems where the observed data are scarce or a typical characteristic property is not significant. The analysis is performed for some systems concerning opinion formation, hydrologic data, financial series etc. Here, Tsallis q-triplet is used to assist the identification of the most appropriate distribution, and in another case we consider q-entropy optimization in the study of mixed states of the system. Next, we propose to extend the idea of the distance from the stationary state indicated by q-stationary parameter in Tsallis statistics, assuming that the distance from a proper regime could be expressed by a corresponding q-function. Therefore an ad hoc q-log-periodic form is introduced to describe the near to log-periodic behavior.

  2. Thermodynamic Properties of the Magnesium-Olivine-Pyroxene System Derived From a Lattice Vibrational Technique

    NASA Astrophysics Data System (ADS)

    Jacobs, M. H.; van den Berg, A. P.; de Jong, B. H.

    2007-12-01

    We are currently constructing a thermodynamic database providing phase diagrams, thermophysical and thermochemical properties for materials with a geophysical relevance, applicable in the pressure and temperature regime of the Earth's mantle. The computational technique is based on Kieffer's (1979) approach to model the vibrational density of states of a substance, a key property to derive the Helmholtz energy. The developed thermodynamic framework, which allows the calculation of Vp and Vs sound wave velocities, uses model-input properties related to Raman and infrared spectroscopic data. It puts tighter constraints on thermodynamic properties compared to methods based on polynomial parameterizations of thermal expansivity, heat capacity and isothermal bulk modulus. Jacobs & de Jong (2005, 2007) showed that this framework discriminates, based on internal consistency, between the quality of disparate sets of experimental thermochemical, thermophysical and phase diagram data. The present work focuses on the application of vibrational modeling to the magnesium-olivine-pyroxene system, a system relevant to Earth's mantle. We show how our approach is used to point to inconsistencies in experimental datasets. Pressure calibration problems affecting the derivation of phase diagrams are discussed. The results, presented here, were used in a numerical model of convection in the Earth's mantle to reveal, effects of phase transitions on the degree of layering, mineral distribution and sound wave velocities in the transition zone, around 660 km depth in the Earth. References Kieffer S.W. (1979), Rev. Geophys. Space Physics, 17, 35-59. Jacobs M.H.G. and B.H.W.S. de Jong (2005), Phys. Chem. Minerals, 32, 614-626. Jacobs M.H.G., and de Jong B.H.W.S. (2007), Geochim. Cosmochim. Acta, 71, 3630-3655.

  3. Development of methacrylate/silorane hybrid monomer system: Relationship between photopolymerization behavior and dynamic mechanical properties.

    PubMed

    Song, Linyong; Ye, Qiang; Ge, Xueping; Singh, Viraj; Misra, Anil; Laurence, Jennifer S; Berrie, Cindy L; Spencer, Paulette

    2016-07-01

    Resin chemistries for dental composite are evolving as noted by the introduction of silorane-based composites in 2007. This shift in the landscape from methacrylate-based composites has fueled the quest for versatile methacrylate-silorane adhesives. The objective of this study was to evaluate the polymerization behavior and structure/property relationships of methacrylate-silorane hybrid systems. Amine compound ethyl-4-(dimethylamino) benzoate (EDMAB) or silane compound tris(trimethylsilyl) silane (TTMSS) was selected as coinitiators. The mechanical properties of the copolymer were improved significantly at low concentrations (15, 25, or 35 wt %) of silorane when EDMAB was used as coinitiator. The rubbery moduli of these experimental copolymers were increased by up to 260%, compared with that of the control (30.8 ± 1.9 MPa). Visible phase separation appeared in these formulations if the silorane concentrations in the formulations were 50-75 wt %. The use of TTMSS as coinitiator decreased the phase separation, but there was a concomitant decrease in mechanical properties. In the neat methacrylate formulations, the maximum rates of free-radical polymerization with EDMAB or TTMSS were 0.28 or 0.06 s(-1) , respectively. In the neat silorane resin, the maximum rates of cationic ring-opening polymerization with EDMAB or TTMSS were 0.056 or 0.087 s(-1) , respectively. The phase separation phenomenon may be attributed to differences in the rates of free-radical polymerization of methacrylates and cationic ring-opening polymerization of silorane. In the hybrid systems, free-radical polymerization initiated with EDMAB led to higher crosslink density and better mechanical properties under dry/wet conditions. These beneficial effects were, however, associated with an increase in heterogeneity in the network structure. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 841-852, 2016. PMID:25953619

  4. Probing Interstellar Silicate Dust Grain Properties in Quasar Absorption Systems at Redshifts z<1.4

    NASA Astrophysics Data System (ADS)

    Aller, M.; Kulkarni, V. P.; York, D. G.; Welty, D. E.; Vladilo, G.; Som, D.

    Absorption lines in the spectra of distant quasars whose sightlines serendipitously pass through foreground galaxies provide a valuable tool to simultaneously probe the dust and gas compositions of the interstellar medium (ISM) in galaxies. In particular, the damped and sub-damped Lyman- α (DLA/sub-DLA) absorbers trace gas-rich galaxies, independent of the intrinsic luminosities or star-formation rates of the associated galaxy stellar populations. The first evidence of silicate dust in a quasar absorption system was provided through our detection of the 10 µ m silicate feature in the z=0.52 DLA absorber toward the quasar AO 0235+164. We present results from 2 follow-up programs using archival Spitzer Space Telescope infrared spectra to study the interstellar silicate dust grain properties in a total of 13 quasar absorption systems at 0.1 < z < 1.4. We find clear detections of the 10 µ m silicate feature in the quasar absorption systems studied. In addition, we also detect the 18 µ m silicate feature in the sources with adequate spectral coverage. We find variations in the breadth, peak wavelength, and substructure of the 10 µ m interstellar silicate absorption features among the absorbers. This suggests that the silicate dust grain properties in these distant galaxies may differ relative to one another, and relative to those in the Milky Way. We also find suggestions in several sources, based on comparisons with laboratory-derived profiles from the literature, that the silicate dust grains may be significantly more crystalline than those in the amorphous Milky Way ISM. This is particularly evident in the z=0.89 absorber toward the quasar PKS 1830-211, where substructure near 10 µ m is consistent with a crystalline olivine composition. If confirmed, these grain property variations may have implications for both dust and galaxy evolution over the past 9 Gyrs, and for the commonly-made assumption that highredshift dust is similar to local dust. We also discuss

  5. Roles of wind shear at different vertical levels: Cloud system organization and properties

    NASA Astrophysics Data System (ADS)

    Chen, Qian; Fan, Jiwen; Hagos, Samson; Gustafson, William I.; Berg, Larry K.

    2015-07-01

    Understanding critical processes that contribute to the organization of mesoscale convective systems (MCSs) is important for accurate weather forecasts and climate predictions. In this study, we investigate the effects of wind shear at different vertical levels on the organization and properties of convective systems using the Weather Research and Forecasting model with spectral bin microphysics. Based on a control run for a MCS with weak wind shear (Ctrl), we find that increasing wind shear at the lower troposphere (L-shear) leads to a more organized quasi-line convective system. Strong wind shear in the middle troposphere (M-shear) tends to produce large vorticity and form a mesocyclone circulation and an isolated strong storm that leans toward supercellular structure. By increasing wind shear at the upper vertical levels only (U-shear), the organization of the convection is not changed much, but the convective intensity is weakened. Increasing wind shear in the middle troposphere for the selected case results in a significant drying, and the drying is more significant when conserving moisture advection at the lateral boundaries, contributing to the suppressed convective strength and precipitation relative to Ctrl. Precipitation in the L-shear and U-shear does not change much from Ctrl. Evident changes of cloud macrophysical and microphysical properties in the strong wind shear cases are mainly due to large changes in convective organization and water vapor. The insights obtained from this study help us better understand the major factors contributing to convective organization and precipitation.

  6. Impact of thermal energy storage properties on solar dynamic space power conversion system mass

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.; Coles-Hamilton, Carolyn E.; Lacy, Dovie E.

    1987-01-01

    A 16 parameter solar concentrator/heat receiver mass model is used in conjunction with Stirling and Brayton Power Conversion System (PCS) performance and mass computer codes to determine the effect of thermal energy storage (TES) material property changes on overall PCS mass as a function of steady state electrical power output. Included in the PCS mass model are component masses as a function of thermal power for: concentrator, heat receiver, heat exchangers (source unless integral with heat receiver, heat sink, regenerator), heat engine units with optional parallel redundancy, power conditioning and control (PC and C), PC and C radiator, main radiator, and structure. Critical TES properties are: melting temperature, heat of fusion, density of the liquid phase, and the ratio of solid-to-liquid density. Preliminary results indicate that even though overalll system efficiency increases with TES melting temperature up to 1400 K for concentrator surface accuracies of 1 mrad or better, reductions in the overall system mass beyond that achievable with lithium fluoride (LiF) can be accomplished only if the heat of fusion is at least 800 kJ/kg and the liquid density is comparable to that of LiF (1880 kg/cu m.

  7. Impact of thermal energy storage properties on solar dynamic space power conversion system mass

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.; Coles-Hamilton, Carolyn E.; Lacy, Dovie E.

    1987-01-01

    A 16 parameter solar concentrator/heat receiver mass model is used in conjunction with Stirling and Brayton Power Conversion System (PCS) performance and mass computer codes to determine the effect of thermal energy storage (TES) material property changes on overall PCS mass as a function of steady state electrical power output. Included in the PCS mass model are component masses as a function of thermal power for: concentrator, heat receiver, heat exchangers (source unless integral with heat receiver, heat sink, regenerator), heat engine units with optional parallel redundancy, power conditioning and control (PC and C), PC and C radiator, main radiator, and structure. Critical TES properties are: melting temperature, heat of fusion, density of the liquid phase, and the ratio of solid-to-liquid density. Preliminary results indicate that even though overall system efficiency increases with TES melting temperature up to 1400 K for concentrator surface accuracies of 1 mrad or better, reductions in the overall system mass beyond that achievable with lithium fluoride (LiF) can be accomplished only if the heat of fusion is at least 800 kJ/kg and the liquid density is comparable to that of LiF (1800 kg/cu m).

  8. Equilibrium and nonequilibrium properties of systems with long-range interactions

    NASA Astrophysics Data System (ADS)

    Ruffo, S.

    2008-08-01

    We briefly review some equilibrium and nonequilibrium properties of systems with long-range interactions. Such systems, which are characterized by a potential that weakly decays at large distances, have striking properties at equilibrium, like negative specific heat in the microcanonical ensemble, temperature jumps at first order phase transitions, broken ergodicity. Here, we mainly restrict our analysis to mean-field models, where particles globally interact with the same strength. We show that relaxation to equilibrium proceeds through quasi-stationary states whose duration increases with system size. We propose a theoretical explanation, based on Lynden-Bell’s entropy, of this intriguing relaxation process. This allows to address problems related to nonequilibrium using an extension of standard equilibrium statistical mechanics. We discuss in some detail the example of the dynamics of the free electron laser, where the existence and features of quasi-stationary states is likely to be tested experimentally in the future. We conclude with some perspectives to study open problems and to find applications of these ideas to dipolar media.

  9. Hybrid systems based on "drug - in cyclodextrin - in nanoclays" for improving oxaprozin dissolution properties.

    PubMed

    Mura, Paola; Maestrelli, Francesca; Aguzzi, Carola; Viseras, César

    2016-07-25

    A combined approach based on drug complexation with cyclodextrins, and complex entrapment in nanoclays has been investigated, to join in a single delivery system the benefits of these carriers and potentiate their ability to improve the dissolution properties of oxaprozin (OXA), a poorly water-soluble anti-inflammatory drug. Based on previous studies, randomly methylated ß-cyclodextrin (RAMEB) was chosen as the most effective cyclodextrin for OXA complexation. Adsorption equilibrium studies performed on three different clays (sepiolite, attapulgite, bentonite) allowed selection of sepiolite (SV) for its greater adsorption power towards OXA. DSC and XRPD studies indicated drug amorphization in both binary OXA-RAMEB coground and OXA-SV cofused products, due to its complexation or very fine dispersion in the clay structure, respectively. The drug amorphous state was maintained also in the ternary OXA-RAMEB-SV cofused system. Dissolution studies evidenced a clear synergistic effect of RAMEB complexation and clay nanoencapsulation in improving the OXA dissolution properties, with an almost 100% increase in percent dissolved and dissolution efficiency compared to the OXA-RAMEB coground system. Therefore, the proposed combined approach represents an interesting tool for improving the therapeutic effectiveness of poorly soluble drugs, and reducing the CD amount necessary for obtaining the desired drug solubility and dissolution rate increase. PMID:27188644

  10. Analysis of nodal aberration properties in off-axis freeform system design.

    PubMed

    Shi, Haodong; Jiang, Huilin; Zhang, Xin; Wang, Chao; Liu, Tao

    2016-08-20

    Freeform surfaces have the advantage of balancing off-axis aberration. In this paper, based on the framework of nodal aberration theory (NAT) applied to the coaxial system, the third-order astigmatism and coma wave aberration expressions of an off-axis system with Zernike polynomial surfaces are derived. The relationship between the off-axis and surface shape acting on the nodal distributions is revealed. The nodal aberration properties of the off-axis freeform system are analyzed and validated by using full-field displays (FFDs). It has been demonstrated that adding Zernike terms, up to nine, to the off-axis system modifies the nodal locations, but the field dependence of the third-order aberration does not change. On this basis, an off-axis two-mirror freeform system with 500 mm effective focal length (EFL) and 300 mm entrance pupil diameter (EPD) working in long-wave infrared is designed. The field constant aberrations induced by surface tilting are corrected by selecting specific Zernike terms. The design results show that the nodes of third-order astigmatism and coma move back into the field of view (FOV). The modulation transfer function (MTF) curves are above 0.4 at 20 line pairs per millimeter (lp/mm) which meets the infrared reconnaissance requirement. This work provides essential insight and guidance for aberration correction in off-axis freeform system design. PMID:27557003

  11. Factors that influence properties of FOG deposits and their formation in sewer collection systems.

    PubMed

    Iasmin, Mahbuba; Dean, Lisa O; Lappi, Simon E; Ducoste, Joel J

    2014-02-01

    Understanding the formation of Fat, Oil, and Grease (FOG) deposits in sewer systems is critical to the sustainability of sewer collection systems since they have been implicated in causing sewerage blockages that leads to sanitary sewer overflows (SSOs). Recently, FOG deposits in sewer systems displayed strong similarities with calcium-based fatty acid salts as a result of a saponification reaction. The objective of this study was to quantify the factors that may affect the formation of FOG deposits and their chemical and rheological properties. These factors included the types of fats used in FSEs, environmental conditions (i.e. pH and temperature), and the source of calcium in sewer systems. The results of this study showed that calcium content in the calcium based salts seemed to depend on the solubility limit of the calcium source and influenced by pH and temperature conditions. The fatty acid profile of the calcium-based fatty acid salts produced under alkali driven hydrolysis were identical to the profile of the fat source and did not match the profile of field FOG deposits, which displayed a high fraction of palmitic, a long chain saturated fatty acid. It is hypothesized that selective microbial metabolism of fats and/or biologically induced hydrogenation may contribute to the FOG deposit makeup in sewer system. Therefore, selective removal of palmitic in pretreatment processes may be necessary prior to the discharge of FSE wastes into the sewer collection system. PMID:24317022

  12. Bio-inspired metal-coordination dynamics: A unique tool for engineering novel properties in soft matter systems

    NASA Astrophysics Data System (ADS)

    Grindy, Scott; Li, Qiaochu; Halim, Abigail; Learsch, Robert; Holten-Andersen, Niels

    2015-03-01

    In soft material systems, materials properties are generally governed by transient, dynamic interactions of many types over many hierarchal length- and time-scales. However, explicit control over these dynamics is not always possible, leaving open questions into how transient interactions can be exploited to design soft materials with unique and exceptional properties. Inspired by the adhesive chemistry and tough character of mussel byssal threads, we present several studies on both the mechanical properties of soft materials and templated crystallization kinetics to show the diverse array of materials properties that can be generated using bio-inspired metal-coordination. By studying our model systems, we can determine the explicit effects of metal-coordination dynamics on various bulk properties, further adding to the set of tools we can use to design soft material systems.

  13. Atomic transport and surface properties of some simple liquid metal using one component plasma system

    NASA Astrophysics Data System (ADS)

    Sonvane, Yogeshkumar A.; Thakor, Pankajsinh B.; Jani, Ashwin R.

    2012-12-01

    In the present paper, we have calculated diffusion coefficient, viscosity coefficient, and surface tension of liquid metals near melting point (Li, Na, K, Rb, Cs, Mg, Al, Pb, and Bi). We have applied our newly constructed model potential to describe electron ion interaction with one component plasma reference system. We have also investigated the effect of different correction functions such as those of Hartree, Hubbard and Sham, Vashista and Singwi, Taylor, Ichimaru and Utsumi, Farid et al., and Sarkar et al. on the above-said properties. It is observed that the present results are found to be in good agreement with those of experimental data as well as with other theoretical results.

  14. Study of the Properties of Plessey's Electrocardiographic Capacitive Electrodes for Portable Systems

    NASA Astrophysics Data System (ADS)

    Uvarov, A. A.; Lezhnina, I. A.; Overchuk, K. V.; Starchak, A. S.; Akhmedov, Sh D.; Larioshina, I. A.

    2016-01-01

    Cardiac diseases are still most widely spread in all regions of the world. And more and more devices are invented to satisfy increasing requirements of the patients. One of the perspective technologies in cardiac diagnostics is capacitive sensing ECG electrodes. This article describes a study of the properties of electrocardiographic capacitive electrodes PS25255 from Plessey Semiconductors for portable systems as well as some undocumented parameters of these sensors. We developed special cardiograph using Plessey's electrodes and applied to the number of patients with ischemic heart disease. We paid our attention mostly to the correct transition of the ST segment as it has critical impact on the diagnostics of ischemic heart disease.

  15. Optical Properties of a Quantum Dot-Ring System Grown Using Droplet Epitaxy.

    PubMed

    Linares-García, Gabriel; Meza-Montes, Lilia; Stinaff, Eric; Alsolamy, S M; Ware, M E; Mazur, Y I; Wang, Z M; Lee, Jihoon; Salamo, G J

    2016-12-01

    Electronic and optical properties of InAs/GaAs nanostructures grown by the droplet epitaxy method are studied. Carrier states were determined by k · p theory including effects of strain and In gradient concentration for a model geometry. Wavefunctions are highly localized in the dots. Coulomb and exchange interactions are studied and we found the system is in the strong confinement regime. Microphotoluminescence spectra and lifetimes were calculated and compared with measurements performed on a set of quantum rings in a single sample. Some features of spectra are in good agreement. PMID:27342603

  16. Optical Properties of a Quantum Dot-Ring System Grown Using Droplet Epitaxy

    NASA Astrophysics Data System (ADS)

    Linares-García, Gabriel; Meza-Montes, Lilia; Stinaff, Eric; Alsolamy, S. M.; Ware, M. E.; Mazur, Y. I.; Wang, Z. M.; Lee, Jihoon; Salamo, G. J.

    2016-06-01

    Electronic and optical properties of InAs/GaAs nanostructures grown by the droplet epitaxy method are studied. Carrier states were determined by k · p theory including effects of strain and In gradient concentration for a model geometry. Wavefunctions are highly localized in the dots. Coulomb and exchange interactions are studied and we found the system is in the strong confinement regime. Microphotoluminescence spectra and lifetimes were calculated and compared with measurements performed on a set of quantum rings in a single sample. Some features of spectra are in good agreement.

  17. Modeling and Properties of Nonlinear Stochastic Dynamical System of Continuous Culture

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Feng, Enmin; Ye, Jianxiong; Xiu, Zhilong

    The stochastic counterpart to the deterministic description of continuous fermentation with ordinary differential equation is investigated in the process of glycerol bio-dissimilation to 1,3-propanediol by Klebsiella pneumoniae. We briefly discuss the continuous fermentation process driven by three-dimensional Brownian motion and Lipschitz coefficients, which is suitable for the factual fermentation. Subsequently, we study the existence and uniqueness of solutions for the stochastic system as well as the boundedness of the Two-order Moment and the Markov property of the solution. Finally stochastic simulation is carried out under the Stochastic Euler-Maruyama method.

  18. An experimental test plan for the characterization of molten salt thermochemical properties in heat transport systems

    SciTech Connect

    Pattrick Calderoni

    2010-09-01

    Molten salts are considered within the Very High Temperature Reactor program as heat transfer media because of their intrinsically favorable thermo-physical properties at temperatures starting from 300 C and extending up to 1200 C. In this context two main applications of molten salt are considered, both involving fluoride-based materials: as primary coolants for a heterogeneous fuel reactor core and as secondary heat transport medium to a helium power cycle for electricity generation or other processing plants, such as hydrogen production. The reference design concept here considered is the Advanced High Temperature Reactor (AHTR), which is a large passively safe reactor that uses solid graphite-matrix coated-particle fuel (similar to that used in gas-cooled reactors) and a molten salt primary and secondary coolant with peak temperatures between 700 and 1000 C, depending upon the application. However, the considerations included in this report apply to any high temperature system employing fluoride salts as heat transfer fluid, including intermediate heat exchangers for gas-cooled reactor concepts and homogenous molten salt concepts, and extending also to fast reactors, accelerator-driven systems and fusion energy systems. The purpose of this report is to identify the technical issues related to the thermo-physical and thermo-chemical properties of the molten salts that would require experimental characterization in order to proceed with a credible design of heat transfer systems and their subsequent safety evaluation and licensing. In particular, the report outlines an experimental R&D test plan that would have to be incorporated as part of the design and operation of an engineering scaled facility aimed at validating molten salt heat transfer components, such as Intermediate Heat Exchangers. This report builds on a previous review of thermo-physical properties and thermo-chemical characteristics of candidate molten salt coolants that was generated as part of the

  19. Physical and Nutritional Properties of Catfish Roe Spray Dried Protein Powder and its Application in an Emulsion System

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soluble spray dried protein powder (CRP) was made from catfish roe and its physical and nutritional properties evaluated. An emulsion system (CRPE) was developed using CRP and rheological properties compared with two commercial mayonnaises (RME and RVE). CRP contained 67 % protein, 4.5% moisture, ...

  20. 41 CFR 109-1.5204 - Review and approval of a designated contractor's personal property management system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... overhaul; and (2) An analysis of the cost to implement the overhaul within a year versus a proposed... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false Review and approval of a designated contractor's personal property management system. 109-1.5204 Section 109-1.5204 Public...

  1. Gas transfer system in Alvinella pompejana (Annelida polychaeta, Terebellida): functional properties of intracellular and extracellular hemoglobins.

    PubMed

    Hourdez, S; Lallier, F H; De Cian, M C; Green, B N; Weber, R E; Toulmond, A

    2000-01-01

    Alvinella pompejana is a tubicolous polychaete that dwells in the hottest part of the hydrothermal vent ecosystem in a highly variable mixture of vent (350 degrees C, anoxic, CO(2)- and sulfide-rich) and deep-sea (2 degrees C, mildly hypoxic) waters. This species has developed distinct-and specifically respiratory-adaptations to this challenging environment. An internal gas exchange system has recently been described, along with the report of an intracellular coelomic hemoglobin, in addition to the previously known extracellular vascular hemoglobin. This article reports the structure of coelomic hemoglobin and the functional properties of both hemoglobins in order to assess possible oxygen transfer. Coelomocytes contain a unique monomeric hemoglobin with a molecular weight of 14,810+/-1.5 Da, as determined by mass spectrometry. The functional properties of both hemoglobins are unexpectedly very similar under the same conditions of pH (6.1-8.2) and temperature (10 degrees -40 degrees C). The oxygen affinity of both proteins is relatively high (P50=0.66 Torr at 20 degrees C and pH 7), which facilitates oxygen uptake from the hypoxic environment. A strong Bohr effect (Phi ranging from -0.8 to -1.0) allows the release of oxygen to acidic tissues. Such similar properties imply a possible bidirectional transfer of oxygen between the two hemoglobins in the perioesophagal pouch, a mechanism that could moderate environmental variations of oxygen concentration and maintain brain oxygenation. PMID:10893176

  2. Structural, thermodynamic, mechanical, and magnetic properties of FeW system

    SciTech Connect

    Ren, Q. Q.; Fan, J. L.; Han, Y.; Gong, H. R.

    2014-09-07

    The Fe-W system is systematically investigated through a combined use of first-principles calculation, cluster expansion, special quasirandom structures, and experiments. It is revealed that the ferromagnetic state of BCC Fe-W solid solution has lower heat of formation than its nonmagnetic state within the entire composition range, and intermetallic λ-Fe{sub 2}W and μ-Fe{sub 7}W{sub 6} phases are energetically favorable with negative heats of formation. Calculations also show that the Fe-W solid solution has much lower coefficient of thermal expansion than its mechanical mixture, and that the descending sequence of temperature-dependent elastic moduli of each Fe-W solid solution is E > G > B. Moreover, magnetic state should have an important effect on mechanical properties of Fe-W phases, and electronic structures can provide a deeper understanding of various properties of Fe-W. The derived results agree well with experimental observations, and can clarify two experimental controversies regarding structural stability and magnetic property of Fe-W phases in the literature.

  3. Mechanical property tests on structural materials for ITER magnet system at low temperatures in China

    NASA Astrophysics Data System (ADS)

    Huang, Chuanjun; Huang, Rongjin; Li, Laifeng

    2014-01-01

    High field superconducting magnets need strong non-superconducting components for structural reinforcement. For instance, the ITER magnet system (MS) consists of cable-in-conduit conductor, coil case, magnet support, and insulating materials. Investigation of mechanical properties at magnet operation temperature with specimens machined at the final manufacturing stages of the conductor jacket materials, magnet support material, and insulating materials, even the component of the full-size conductor jacket is necessary to establish sound databases for the products. In China, almost all mechanical property tests of structural materials for the ITER MS, including conductor jacket materials of TF coils, PF coils, CCs, case material of CCs, conductor jacket materials of Main Busbars (MB) and Corrector Busbars (CB), material of magnet supports, and insulating materials of CCs have been carried out at the Technical Institute of Physics and Chemistry (TIPC), Chinese Academy of Sciences (CAS). In this paper, the mechanical property test facilities are briefly demonstrated and the mechanical tests on the structural materials for the ITER MS, highlighting test rigs as well as test methods, are presented.

  4. Validation of CHEMEST, an on-line system for the estimation of chemical properties

    SciTech Connect

    Boethling, R.S.; Campbell, S.E.; Lynch, D.G.; LaVeck, G.D.

    1988-02-01

    CHEMEST is an on-line system for estimating physical/chemical properties important in the assessment of environmental fate of chemicals. Measured values of boiling point, melting point, vapor pressure, water solubility, and soil organic carbon partition coefficient (Koc) were compared to values estimated by CHEMEST, for more than 170 chemicals. The chemicals were composed of seven classes: alcohols, aldehydes and ketones, amines, carbamates, esters, ethers, and phenols. Mean errors for boiling and melting point were 22.6 and 36.2 degrees C, respectively, with relatively little variability among classes. Carbamates were an exception, accuracy being much lower for both properties. Vapor pressures were quite accurately estimated, measured and estimated values generally differing by less than a factor of two. Mean error factors for water solubility and Koc were somewhat higher, but nevertheless better than the order of magnitude accuracy commonly assumed. Solubility was very inaccurately estimated for the phenols, however. The results indicate that, for the chemicals and properties studied, estimated values were sufficiently accurate for screening-level fate assessment. TSTCHEM, a revised version of CHEMEST, out-performed the latter with respect to the accuracy of solubility and vapor pressure estimates.

  5. ESTIMATION OF INHERENT OPTICAL PROPERTIES AND THE WATER QUALITY COMPONENTS IN THE NEUSE RIVER-PAMLICO SOUND ESTUARINE SYSTEM

    EPA Science Inventory

    Field observations carried out in the Neuse River-Pamlico Sound Estuarine System (NRE-PS), North Carolina, USA were used to develop optical algorithms for assessing inherent optical properties, IOPs (absorption and backscattering) associated with water quality components (WQC).

  6. Surface properties of an indirect composite polymerized with five laboratory light polymerization systems.

    PubMed

    Murakami, Mahoko

    2009-06-01

    A study was conducted to evaluate the influence of laboratory light polymerization systems on the post-curing properties of a composite. An indirect composite (Sinfony) was polymerized with five polymerization systems (Visio system, Hyper LII, Pearlcure Light, Twinkle MIII, and UniXS II) using nine polymerization modes. After light exposure, Knoop hardness number, wear depth, and changes in gloss were determined. The highest hardness number was recorded with the use of the Hyper LII (120 s) and Pearlcure Light (120 s) units, whereas the lowest value was obtained with the Visio system and UniXS II (60 s). Six groups demonstrated comparable as well as higher wear resistance to toothbrush abrasion (Hyper LII 60 and 120 s, UniXS II 120 s, Pearlcure Light 60 and 120 s, and Twinkle MIII 120 s), and two groups exhibited lower wear resistance (Visio system and UniXS II 60 s). Gloss of the composite was not dependent on the polymerization mode used before wear testing. However, surface gloss was significantly reduced by toothbrush dentifrice abrasion. Within the limitations of the present experiment, it can be concluded that the Sinfony composite can be polymerized sufficiently with high-intensity light polymerization units. PMID:19550089

  7. Detection and Properties of Extrasolar Planets in Double and Multiple Star Systems

    NASA Astrophysics Data System (ADS)

    Eggenberger, A.; Udry, S.; Mayor, M.; Beuzit, J.-L.; Lagrange, A. M.; Chauvin, G.

    2004-12-01

    Among the extrasolar planets known today, 19 are orbiting a component of a multiple star system. In this contribution, we show that the properties of planets found in multiple star systems seem to be different from the ones of planets orbiting isolated stars: (i) as pointed out by Zucker & Mazeh (2002), the most massive short-period planets are all found in binaries; (ii) planets orbiting a component of a multiple star system tend to have a very low eccentricity when their period is shorter than about 40 days. These observations suggest that some kind of migration has been present in the history of the short-period planets found in multiple star systems, but are not easily explained by the current models of planet formation and evolution. Our knowledge regarding the existence and the characteristics of extrasolar planets in multiple star systems is, however, far from being complete. In particular, the influence of stellar duplicity on planet formation and evolution is still to be quantified. This is the goal of our VLT/NACO adaptive optics survey, which is also discussed here.

  8. Evaluation of basic imaging properties of a new digital chest system

    NASA Astrophysics Data System (ADS)

    Montner, Steven M.; Xu, Xin-Wei; Tsuzaka, Masatoshi; Doi, Kunio; MacMahon, Heber; Yoshimura, Hitoshi; Sanada, Shigeru; Giger, Maryellen L.; Yin, Fang-Fang

    1990-07-01

    A prototype digital chest system, which uses storage phosphor technology and has the advantages over existing computed radiography systems (CR) of compactness and immediate image display, is being evaluated in our laboratory. We evaluated the imaging properties of the Konica Direct Digitizer (KDD) in order to assess its potential usefulness for general clinical use, or as a front-end for a PACS. The prototype system consists of a new stimulable phosphor (RbBr.Tl) detector read by a compact semiconductor laser scanning system, with images immediately displayed on a CRT or transferred to a host computer. The imaging characteristics of resolution and noise were evaluated, using display parameters matched to a Kodak Lanex Medium/OC system. Preliminary results using sensitive composite test objects show an increase in noise and a slight decrease in resolution as compared to conventional radiography. However, subjective comparison of a chest phantom and volunteer images indicates that these differences may not be clinically significant. Further development is needed to provide increased absorption, and thus improved image quality.

  9. Mechanical properties of the fiberglass prepreg system used for the National Transonic Facility replacement blade set

    NASA Technical Reports Server (NTRS)

    Young, Clarence P., Jr.; Wallace, John W.

    1991-01-01

    The results are presented of mechanical and physical properties characterization testing for the fiber glass prepreg system used to fabricate 15 of the replacement set of 25 fan blades for the National Transonic Facility. The fan blades were fabricated to be identical to the original blade set with the exception that the 7576 style E glass cloth used for the replacement set has a different surface finish than the original 7576 cloth. The 7781 E glass cloth and resin system were unchanged. The data are presented for elevated, room, and cryogenic temperatures. The results are compared with data from the original blade set and evaluated against selected structural design criteria. Test experience is described along with recommendations for future testing of these materials if required.

  10. Self-organized criticality as a fundamental property of neural systems

    PubMed Central

    Hesse, Janina; Gross, Thilo

    2014-01-01

    The neural criticality hypothesis states that the brain may be poised in a critical state at a boundary between different types of dynamics. Theoretical and experimental studies show that critical systems often exhibit optimal computational properties, suggesting the possibility that criticality has been evolutionarily selected as a useful trait for our nervous system. Evidence for criticality has been found in cell cultures, brain slices, and anesthetized animals. Yet, inconsistent results were reported for recordings in awake animals and humans, and current results point to open questions about the exact nature and mechanism of criticality, as well as its functional role. Therefore, the criticality hypothesis has remained a controversial proposition. Here, we provide an account of the mathematical and physical foundations of criticality. In the light of this conceptual framework, we then review and discuss recent experimental studies with the aim of identifying important next steps to be taken and connections to other fields that should be explored. PMID:25294989

  11. Determination of elastic properties of a film-substrate system by using the neural networks

    NASA Astrophysics Data System (ADS)

    Xu, Baiqiang; Shen, Zhonghua; Ni, Xiaowu; Wang, Jijun; Guan, Jianfei; Lu, Jian

    2004-12-01

    An inverse method based on artificial neural network (ANN) is presented to determine the elastic properties of films from laser-genrated surface waves. The surface displacement responses are used as the inputs for the ANN model; the outputs of the ANN are the Young's modulus, density, Poisson's ratio, and thickness of the film. The finite element method is used to calculate the surface displacement responses in a film-substrate system. Levenberg Marquardt algorithm is used as numerical optimization to speed up the training process for the ANN model. In this method, the materials parameters are not recovered from the dispersion curves but rather directly from the transient surface displacement. We have also found that this procedure is very efficient for determining the materials parameters of layered systems.

  12. Heat-flow properties of systems with alternate masses or alternate on-site potentials

    NASA Astrophysics Data System (ADS)

    Pereira, Emmanuel; Santana, Leonardo M.; Ávila, Ricardo

    2011-07-01

    We address a central issue of phononics: the search of properties or mechanisms to manage the heat flow in reliable materials. We analytically study standard and simple systems modeling the heat flow in solids, namely, the harmonic, self-consistent harmonic and also anharmonic chains of oscillators, and we show an interesting insulating effect: While in the homogeneous models the heat flow decays as the inverse of the particle mass, in the chain with alternate masses it decays as the inverse of the square of the mass difference, that is, it decays essentially as the mass ratio (between the smaller and the larger one) for a large mass difference. A similar effect holds if we alternate on-site potentials instead of particle masses. The existence of such behavior in these different systems, including anharmonic models, indicates that it is a ubiquitous phenomenon with applications in the heat flow control.

  13. First-Principles Study for Thermodynamic Properties of Solid {KNO}2 System

    NASA Astrophysics Data System (ADS)

    Peng, Qiang; Ding, Jing; Wei, Xiaolan; Jiang, Gan; Yang, Xiaoxi

    2015-11-01

    To enable us better understand the performance of molten salt energy storage in a solar thermal power system, thermodynamic properties of the solid {KNO}2 system at ambient pressure and temperatures between 0 K and 711 K are determined by first-principles simulation based on density functional perturbation theory calculations with plane waves and pseudopotentials. Thermodynamic parameters of the Debye temperature, specific heat capacity at constant volume, phonon transfer speed, phonon mean free path, and phonon thermal conductivity as a function of temperature are estimated. The results show that the calculated phonon thermal conductivity is in good agreement with experimental values, but the calculated specific heat capacity at constant volume is lower than measured values. The isometric specific heat capacity of {KNO}2 is 75.03 {J}{\\cdot }{mol}^{-1}{\\cdot }{K}^{-1}, and the phonon thermal conductivity is 2.37 {W}{\\cdot }{m}^{-1}{\\cdot }{K}^{-1} at ambient temperature.

  14. Psychometric properties of the Spanish Human System Audit Short-Scale of transformational leadership.

    PubMed

    Berger, Rita; Romeo, Marina; Guardia, Joan; Yepes, Montserrat; Soria, Miguel Angel

    2012-03-01

    The aim of this research is to examine the psychometric properties of a Spanish version of the Human System Audit transformational leadership short-scale (HSA-TFL-ES). It is based on the concept of Bass developed in 1985. The HSA-TFL is a part of the wider Human System Audit frame. We analyzed the HSA-TFL-ES in five different samples with a total number of 1,718 workers at five sectors. Exploratory Factor Analysis corroborated a single factor in all samples that accounted for 66% to 73% of variance. The internal consistency in all samples was good (alpha = .92 - .95). Evidence was found for the convergent validity of the HSA-TFL-ES and the Multifactor Leadership Questionnaire. These results suggested that the HSA-TFL short-scale is a psychometrically sound measure of this construct and can be used for a combined and first overall measurement. PMID:22379726

  15. Equilibrium properties and phase diagram of two-dimensional Yukawa systems

    NASA Astrophysics Data System (ADS)

    Hartmann, P.; Kalman, G. J.; Donkó, Z.; Kutasi, K.

    2005-08-01

    Properties of two-dimensional strongly coupled Yukawa systems are explored through molecular dynamics simulations. An effective coupling coefficient Γ* for the liquid phase is introduced on the basis of the constancy of the first peak amplitude of the pair-correlation functions. Thermodynamic quantities are calculated from the pair-correlation function. The solid-liquid transition of the system is investigated through the analysis of the bond-angular order parameter. The static structure function satisfies consistency relation, attesting to the reliability of the computational method. The response is shown to be governed by the correlational part of the inverse compressibility. An analysis of the velocity autocorrelation demonstrates that this latter also exhibits a universal behavior.

  16. Equilibrium properties and phase diagram of two-dimensional Yukawa systems

    SciTech Connect

    Hartmann, P.; Donko, Z.; Kutasi, K.; Kalman, G.J.

    2005-08-01

    Properties of two-dimensional strongly coupled Yukawa systems are explored through molecular dynamics simulations. An effective coupling coefficient {gamma}{sup *} for the liquid phase is introduced on the basis of the constancy of the first peak amplitude of the pair-correlation functions. Thermodynamic quantities are calculated from the pair-correlation function. The solid-liquid transition of the system is investigated through the analysis of the bond-angular order parameter. The static structure function satisfies consistency relation, attesting to the reliability of the computational method. The response is shown to be governed by the correlational part of the inverse compressibility. An analysis of the velocity autocorrelation demonstrates that this latter also exhibits a universal behavior.

  17. Study of the superconducting properties of the Bi-Ca-Sr-Cu-O system

    NASA Technical Reports Server (NTRS)

    Khan, Musheer H.; Naqvi, S. M. M. R.; Zia-Ul-haq, S. M.

    1991-01-01

    High Temperature Superconductivity in the Bi-Ca-Sr-Cu-O System has been observed and has attracted considerable attention in 1988. The 80 K superconductivity phase has been identified to have a composition of Bi2CaSr2Cu2Ox, while the 110 K phase as reported in the literature has a possible composition of Bi2Ca2Sr2Cu3O(x). Researchers present here a study of the electrical properties of bulk samples of the slowly cooled and rapidly quenched 2:1:2:2 system. The samples used in this study were prepared from appropriate amounts of Bi2O3, CuO, SrCO3, CaCO3.

  18. Study of the superconducting properties of the Bi-Ca-Sr-Cu-O system

    NASA Technical Reports Server (NTRS)

    Khan, Musheer H.; Qidwai, A. A.; Zia-Ul-haq, S. M.; Binsaif, Rashid

    1990-01-01

    High Temperature Superconductivity in the Bi-Ca-Sr-Cu-O System has been observed and has attracted considerable attention in 1988. The 80 K superconductivity phase has been identified to have a composition of Bi2CaSr2Cu2Ox, while the 110 K phase as reported in the literature has a possible composition of Bi2Ca2Sr2Cu3Ox. Researchers present here a study of the electrical properties of bulk samples of the slowly cooled and rapidly quenched 2:1:2:2 system. The samples used in this study were prepared from appropriate amounts of Bi2O3, CuO, SrCO3, CaCO3.

  19. Double layer paclitaxel delivery systems based on bioresorbable terpolymer with shape memory properties.

    PubMed

    Musiał-Kulik, Monika; Kasperczyk, Janusz; Smola, Anna; Dobrzyński, Piotr

    2014-04-25

    The growing interest in the bioresorbable polymers contributed to developing a number of commercially available controlled drug delivery systems. Due to a variety of drugs and their physicochemical properties, there is a necessity of choosing an appropriate drug carrier. Terpolymer with shape memory properties was used to obtain double layer matrices composed of drug free matrix and paclitaxel containing layer. The in vitro degradation and drug release study were conducted at 37 °C in PBS (pH 7.4). The investigated materials were characterized by GPC (gel permeation chromatography) and DSC (differential scanning calorimetry). HPLC (high-pressure liquid chromatography) was applied to analyze the amount of released paclitaxel. The main purpose of this work was to determine the usefulness of the studied terpolymer as an anti-restenotic drug vehicle. Based on the obtained results it was established that polymer's degradation proceeded regularly and provided even paclitaxel release profiles. Double layer systems allowed to modify the amount of released drug which may be considered while developing the self-expanding drug-eluting stents tailoring different clinical indications. PMID:24491529

  20. A humidity controlled Nephelometer system to study the hygroscopic properties of aerosols in the marine environment

    NASA Astrophysics Data System (ADS)

    Vaishya, Aditya; O'Dowd, Colin; Jennings, S. Gerard

    2010-05-01

    A Humidograph system has been designed to study the hygroscopic properties of aerosols for different air-masses and for different seasons in the marine environment. Since ambient marine aerosols are likely to be found in a metastable state, and in accordance with recommendations of WMO/GAW to sample dry aerosol, a drying unit (Nafion based) is placed just after the inlet to dry the aerosols to a relative humidity (RH) < 40% so as not to misinterpret the optical properties of hygroscopic aerosols if they are on the descending branch of the hysteresis curve. The flow after the dryer is split into two, one going to a 3-wavelength TSI-3563 Integrating Nephelometer, and the other to a Gore-Tex based humidifier followed by a single-wavelength TSI-3561 Integrating Nephelometer. The humidifier is used to vary the RH from 40% to 90%. While the TSI-3563 Integrating Nephelometer will operate at RH < 40%, the TSI-3561 Integrating Nephelometer will operate under varying RH conditions. Software developed in LabVIEW is used to control the hardware components and to log the data in a predefined format. Results of the performance of the Humidograph system in the laboratory and at the Mace Head Atmospheric Research Station are presented.

  1. Measuring the retina optical properties using a structured illumination imaging system

    NASA Astrophysics Data System (ADS)

    Basiri, A.; Nguyen, T. A.; Ibrahim, M.; Nguyen, Q. D.; Ramella-Roman, Jessica C.

    2011-03-01

    Patients with diabetic retinopathy (DR) may experience a reduction in retinal oxygen saturation (SO2). Close monitoring with a fundus ophthalmoscope can help in the prediction of the progression of disease. In this paper we present a noninvasive instrument based on structured illumination aimed at measuring the retina optical properties including oxygen saturation. The instrument uses two wavelngths one in the NIR and one visible, a fast acquisition camera, and a splitter system that allows for contemporaneous collection of images at two different wavelengths. This scheme greatly reduces eye movement artifacts. Structured illumination was achieved in two different ways, firstly several binary illumination masks fabricated using laser micro-machining were used, a near-sinusoidal projection pattern is ultimately achieved at the image plane by appropriate positioning of the binary masks. Secondarily a sinusoidal pattern printed on a thin plastic sheet was positioned at image plane of a fundus ophthalmoscope. The system was calibrated using optical phantoms of known optical properties as well as an eye phantom that included a 150μm capillary vessel containing different concentrations of oxygenated and deoxygenated hemoglobin.

  2. Electrospun upconversion composite fibers as dual drugs delivery system with individual release properties.

    PubMed

    Hou, Zhiyao; Li, Xuejiao; Li, Chunxia; Dai, Yunlu; Ma, Ping'an; Zhang, Xiao; Kang, Xiaojiao; Cheng, Ziyong; Lin, Jun

    2013-07-30

    Novel multifunctional poly(ε-caprolactone)-gelatin encapsulating upconversion core/shell silica nanoparticles (NPs) composite fibers as dual drugs delivery system (DDDS), with indomethacin (IMC) and doxorubicin (DOX) releasing in individual release properties, have been designed and fabricated via electrospinning process. Uniform and monodisperse upconversion (UC) luminescent NaYF4:Yb(3+), Er(3+) nanocrystals (UCNCs) were encapsulated with mesoporous silica shells, resulting in the formation of core/shell structured NaYF4:Yb(3+), Er(3+)@mSiO2 (UCNCs@mSiO2) NPs, which can be performed as DOX delivery carriers. These UCNCs@mSiO2 NPs loading DOX then were dispersed into the mixture of poly(ε-caprolactone) (PCL) and gelatin-based electrospinning solution containing IMC, followed by the preparation of dual drug-loaded composite fibers (DDDS) via electrospinning method. The drugs release profiles of the DDDS were measured, and the results indicated that the IMC and DOX released from the electrospun composite fibers showed distinct properties. The IMC in the composite fibers presented a fast release manner, while DOX showed a sustained release behavior. Moreover, the UC luminescent intensity ratios of (2)H(11/2)/(4)S(3/2)-(4)I(15/2) to (4)F(9/2)-(4)I(15/2) from Er(3+) vary with the amounts of DOX in the system, and thus drug release can be tracked and monitored by the luminescence resonance energy transfer (LRET) mechanism. PMID:23855606

  3. The physicodynamic properties of mucoadhesive polymeric films developed as female controlled drug delivery system.

    PubMed

    Yoo, Jin-Wook; Dharmala, Kiran; Lee, Chi H

    2006-02-17

    To develop an efficient female controlled drug delivery system (FcDDS) against sexually transmitted diseases (STDs), the polymeric films containing sodium dodecyl sulfate (SDS) were prepared with various compositions of Carbopol 934P, hydroxypropyl methylcellulose (HPMC) and polyethylene glycol (PEG). The physicochemical properties of mucoadhesive polymeric films, such as tensile strength, contact angle, swelling ratio and erosion rate in a vaginal fluid stimulant (VFS), were characterized. In addition, the drug release profile of SDS from the films and mucosal residence time were evaluated using a simulated dynamic vaginal system. It was demonstrated that the films made of Carbopol, HPMC and PEG were colorless, thin and soft and had proper physicodynamic properties for FcDDS. An increase in Carbopol content elevated tensile strength and swelling ratio but decreased the contact angle, erosion rate and the SDS release rate from the films. The films containing 0.25% (w/v) PEG as well as 0.75% (w/v) of combining Carbopol and HPMC remained on the vaginal tissue for up to 6h. The films containing the ratio of Carbopol:HPMC:PEG=1.5:1.5:1 and 1:2:1 seem to be optimal compositions for FcDDS, as they showed good peelability, relatively high swelling index and moderate tensile strength, and achieved the target release rate of SDS for 6h. PMID:16376036

  4. High-Pressure Induced New Phases and Properties in Typical Molecular Systems

    NASA Astrophysics Data System (ADS)

    Cui, Tian

    2013-06-01

    High pressure introduces new phases by the rearrangement of atoms and reconfigurations of electronic states in materials, often with new physical and chemical phenomena. Study of the new phases in typical molecular systems under high pressure is an interesting subject, such as energy storage materials of solid hydrogen and polymeric nitrogen, hydrogen-rich compound with high-Tc superconductivity under high pressure, high pressure induced metallization of hydrogen, etc. High-pressure structures and pressure-induced phase transitions in the typical molecular solids, such as solid iodine, CHBr3, N2/CN, HBr/HCl, hydrogen-rich compounds (H2S, ZrH2, AsH3, BaReH9, etc.), and group IVA hydrides (Si2H6, Ge2H6, Sn2H6, etc.) are investigated extensively by means of first-principles density functional theory and extensive prediction strategies (molecular dynamics simulation, simulated annealing, soft mode phase transition, random structure-searching method and evolutionary methodology etc.). The new structures and new properties derived from pressure-induced phase transitions in these typical molecular systems have been observed. It is showed that high pressure provides a path for producing new materials with new properties.

  5. Block Copolymer Modified Epoxy Amine System for Reactive Rotational Molding: Structures, Properties and Processability

    NASA Astrophysics Data System (ADS)

    Lecocq, Eva; Nony, Fabien; Tcharkhtchi, Abbas; Gérard, Jean-François

    2011-05-01

    Poly(styrene-butadiene-methylmethacrylate) (SBM) and poly(methylmethacrylate-butyle-acrylate-methylmethacrylate) (MAM) triblock copolymers have been dissolved in liquid DGEBA epoxy resin which is subsequently polymerized by meta-xylene diamine (MXDA) or Jeffamine EDR-148. A chemorheology study of these formulations by plate-plate rheology and by thermal analysis has allowed to conclude that the addition of these copolymer blocks improve the reactive rotational moulding processability without affecting the processing time. Indeed, it prevents the pooling of the formulation at the bottom of the mould and a too rapid build up of resin viscosity of these thermosetting systems. The morphology of the cured blends examined by scanning electron microscopy (SEM) shows an increase of fracture surface area and thereby a potential increase of the toughness with the modification of epoxy system. Dynamic mechanical spectroscopy (DMA) and opalescence of final material show that the block PMMA, initially miscible, is likely to induce phase separation from the epoxy-amine matrix. Thereby, the poor compatibilisation between the toughener and the matrix has a detrimental effect on the tensile mechanical properties. The compatibilisation has to be increased to improve in synergy the processability and the final properties of these block copolymer modified formulations. First attempts could be by adapting the length and ratio of each block.

  6. Hopf bifurcation analysis for a dissipative system with asymmetric interaction: Analytical explanation of a specific property of highway traffic.

    PubMed

    Nomura, Yasuyuki; Saito, Satoshi; Ishiwata, Ryosuke; Sugiyama, Yuki

    2016-01-01

    A dissipative system with asymmetric interaction, the optimal velocity model, shows a Hopf bifurcation concerned with the transition from a homogeneous motion to the formation of a moving cluster, such as the emergence of a traffic jam. We investigate the properties of Hopf bifurcation depending on the particle density, using the dynamical system for the traveling cluster solution of the continuum system derived from the original discrete system of particles. The Hopf bifurcation is revealed as a subcritical one, and the property explains well the specific phenomena in highway traffic: the metastability of jamming transition and the hysteresis effect in the relation of car density and flow rate. PMID:26871081

  7. Hopf bifurcation analysis for a dissipative system with asymmetric interaction: Analytical explanation of a specific property of highway traffic

    NASA Astrophysics Data System (ADS)

    Nomura, Yasuyuki; Saito, Satoshi; Ishiwata, Ryosuke; Sugiyama, Yuki

    2016-01-01

    A dissipative system with asymmetric interaction, the optimal velocity model, shows a Hopf bifurcation concerned with the transition from a homogeneous motion to the formation of a moving cluster, such as the emergence of a traffic jam. We investigate the properties of Hopf bifurcation depending on the particle density, using the dynamical system for the traveling cluster solution of the continuum system derived from the original discrete system of particles. The Hopf bifurcation is revealed as a subcritical one, and the property explains well the specific phenomena in highway traffic: the metastability of jamming transition and the hysteresis effect in the relation of car density and flow rate.

  8. Transport and thermodynamic properties of hydrous melts in the system An-Di.

    NASA Astrophysics Data System (ADS)

    Giordano, D.; Potuzak, M.; Romano, C.; Russell, J. K.; Nowak, M.; Dingwell, D. B.

    2006-12-01

    The thermodynamic and transport properties hydrous silicate melts are of fundamental importance for characterization of the dynamics and energetics associated with silicate melts in the Earth. The literature concerning the transport and calorimetric properties of hydrous silicate melts remains scarce. With few exceptions little has been effectively done in order to provide chemical models that bridge the gap between the description of both complex and simple systems. The An-Di system is of general interest to geochemists as well as petrologists because it serves as a simple analogue for basaltic compositions. It was chosen here due to the combination of its simple chemical description and the presence of an extensive database of published experimental data on both its transport and thermodynamic properties. We have measured the viscosity (η)), the glass transition temperatures (Tg) and the heat capacity (Cp) of silicate melts in the An-Di system containing up to 3 wt.% of dissolved H2O. Viscosity data were obtained by using the dilatometric method of micropenetration, whereas a differential scanning calorimeter (DSC) was employed to determine the glass transition temperatures and the heat capacities. In order to characterize the well-known cooling/heating rate dependence of the glass transition temperatures the calorimetric measurements were performed at heating/cooling rate of 5, 10, 15 and 20 K/min. These results together with those of previous experimental studies have been used to provide a compositional model capable of calculating the Newtonian viscosity of melts as well as the Tg and Cp values for the An- Di+H2O system. The non-Arrhenian T-dependence of viscosity is accounted for by the Vogel-Fulcher- Tammann (VFT) and the Adam Gibbs (AG) equations. Our optimizations assume a common, high-T limit (A) for silicate melt viscosity, consistent with values provided by both theoretical and experimental studies. In particular, we also show that glass transition

  9. V and V of Lexical, Syntactic and Semantic Properties for Interactive Systems Through Model Checking of Formal Description of Dialog

    NASA Technical Reports Server (NTRS)

    Brat, Guillaume P.; Martinie, Celia; Palanque, Philippe

    2013-01-01

    During early phases of the development of an interactive system, future system properties are identified (through interaction with end users in the brainstorming and prototyping phase of the application, or by other stakehold-ers) imposing requirements on the final system. They can be specific to the application under development or generic to all applications such as usability principles. Instances of specific properties include visibility of the aircraft altitude, speed… in the cockpit and the continuous possibility of disengaging the autopilot in whatever state the aircraft is. Instances of generic properties include availability of undo (for undoable functions) and availability of a progression bar for functions lasting more than four seconds. While behavioral models of interactive systems using formal description techniques provide complete and unambiguous descriptions of states and state changes, it does not provide explicit representation of the absence or presence of properties. Assessing that the system that has been built is the right system remains a challenge usually met through extensive use and acceptance tests. By the explicit representation of properties and the availability of tools to support checking these properties, it becomes possible to provide developers with means for systematic exploration of the behavioral models and assessment of the presence or absence of these properties. This paper proposes the synergistic use two tools for checking both generic and specific properties of interactive applications: Petshop and Java PathFinder. Petshop is dedicated to the description of interactive system behavior. Java PathFinder is dedicated to the runtime verification of Java applications and as an extension dedicated to User Interfaces. This approach is exemplified on a safety critical application in the area of interactive cockpits for large civil aircrafts.

  10. Low Temperature Mechanical Properties of Cyanate Ester Insulation Systems After Irradiation

    NASA Astrophysics Data System (ADS)

    Fabian, P. E.; Munshi, N. A.; Feucht, S. W.; Bittner-Rohrhofer, K.; Humer, K.; Weber, H. W.

    2004-06-01

    Recent development of alternative resin chemistries has resulted in new, fiber-reinforced, insulation systems for use in superconducting and fusion magnet applications. When compared to traditional epoxy resins, these insulation systems, based on cyanate ester resin chemistry, offer increased radiation resistance and higher operating temperatures that are demanded by new fusion reactor designs, such as the Fusion Ignition Research Experiment (FIRE). The design parameters for FIRE Toroidal Field (TF) coils call for an insulation system capable of withstanding a combined gamma and neutron radiation dose greater than 108 Gy (1010 Rad) and operate at temperatures ranging from cryogenic (77 K) to elevated temperatures up to 373 K. Several of these newly developed composite insulation systems, suitable for the vacuum impregnation, pre-preg, and high-pressure laminate fabrication processes, were irradiated in the TRIGA reactor (Vienna) to varying levels of radiation to gauge their radiation resistance. The insulation materials' shear and compression properties measured at cryogenic temperatures before and after irradiation are presented.

  11. Elastic properties of some selected two-monomer systems as studied by Brillouin spectroscopy.

    PubMed

    Ziobrowski, P; Drozdowski, M; Andrzejewska, E; Marcinkowska, A; Łapsa, K

    2011-08-15

    We present results obtained by Brillouin scattering method for four two-component systems comprising of a high viscosity monomer and a low viscosity monomer. The monomers used were crosslinking (divinyl) or linear (monovinyl) ones. The investigated systems were: divinyl/divinyl-bis-GMA/TEGDM; divinyl/monovinyl-bis-GMA/PEGMM; monovinyl/divinyl-bis-MGMA/TEGDM and monovinyl/monovinyl-bis-MGMA/PEGMM; they were formulated at various molar ratios. The measurements have been performed in temperature range 293-353 K. The following physical parameters characterizing the investigated systems were estimated: hypersonic velocity V, attenuation coefficient α and adiabatic compressibility β, all as a function of temperature and monomer molar ratio. The obtained results have been discussed in terms of the influence of the system composition and viscosity on their elastic properties. Speed of changes of the adiabatic compressibility β as derivative have been also discussed in terms of both, the temperature as well as the component of molar ratio. PMID:20864387

  12. Effect of makeup water properties on the condenser fouling in power planr cooling system

    SciTech Connect

    Safari, I.; Walker, M.; Abbasian, J.; Arastoopour, H.; Hsieh, M-K.; Dzombak, D.; Miller, D.

    2011-01-01

    The thermoelectric power industry in the U.S. uses a large amount of fresh water. As available freshwater for use in thermoelectric power production becomes increasingly limited, use of nontraditional water sources is of growing interest. Utilization of nontraditional water, in cooling systems increases the potential for mineral precipitation on heat exchanger surfaces. In that regard, predicting the accelerated rate of scaling and fouling in condenser is crucial to evaluate the condenser performance. To achieve this goal, water chemistry should be incorporated in cooling system modeling and simulation. This paper addresses the effects of various makeup water properties on the cooling system, namely pH and aqueous speciation, both of which are important factors affecting the fouling rate in the main condenser. Detailed modeling of the volatile species desorption (i.e. CO{sub 2} and NH{sub 3}), the formation of scale in the recirculating system, and the relationship between water quality and the corresponding fouling rates is presented.

  13. On the L^p_\\mu-strong property of orthonormal systems

    NASA Astrophysics Data System (ADS)

    Grigorian, M. G.

    2003-10-01

    Let \\{\\varphi_n(x)\\} be a system of bounded functions complete and orthonormal in L^2_{ \\lbrack 0,1 \\rbrack } and assume that \\Vert\\varphi_n\\Vert _{p_0}\\leqslant\\mathrm{const}, n\\geqslant 1, for some p_0>2. Then the elements of the system can be rearranged so that the resulting system has the L^p_\\mu-strong property: for each \\varepsilon>0 there exists a (measurable) subset E\\subset \\lbrack 0,1 \\rbrack of measure \\vert E\\vert>1-\\varepsilon and a measurable function \\mu(x), 0<\\mu(x)\\leqslant 1, \\mu(x)=1 on E such that for all p>2 and f(x)\\in L^p_\\mu \\lbrack 0,1 \\rbrack one can find a function g(x)\\in L^1_{ \\lbrack 0,1 \\rbrack } coinciding with f(x) on E such that its Fourier series in the system \\{\\varphi_{\\sigma(k)}(x)\\} converges to g(x) in the L^p_\\mu \\lbrack 0,1 \\rbrack -norm and the sequence of Fourier coefficients of this function belongs to all spaces l^q, q>2.

  14. Hydrogen release properties of lithium alanate for application to fuel cell propulsion systems

    NASA Astrophysics Data System (ADS)

    Corbo, P.; Migliardini, F.; Veneri, O.

    In this paper the results of an experimental study on LiAlH 4 (lithium alanate) as hydrogen source for fuel cell propulsion systems are reported. The compound examined in this work was selected as reference material for light metal hydrides, because of its high hydrogen content (10.5 wt.%) and interesting desorption kinetic properties at moderate temperatures. Thermal dynamic and kinetic of hydrogen release from this hydride were investigated using a fixed bed reactor to evaluate the effect of heating procedure, carrier gas flow rate and sample form. The aim of this study was to characterize the lithium alanate decomposition through the reaction steps leading to the formation of Li 3AlH 6 and LiH. A hydrogen tank was designed and realized to contain pellets of lithium alanate as feeding for a fuel cell propulsion system based on a 2-kW Polymeric Electrolyte Fuel Cell (PEFC) stack. The fuel cell system was integrated into the power train comprising DC-DC converter, energy storage systems and electric drive for moped applications (3 kW). The experiments on the power train were conducted on a test bench able to simulate the vehicle behaviour and road characteristics on specific driving cycles. In particular the efficiencies of individual components and overall power train were analyzed evidencing the energy requirements of the hydrogen storage material.

  15. Synthesis and optoelectronic properties of Janus-dendrimer-type multivalent donor-acceptor systems.

    PubMed

    Dengiz, Cagatay; Breiten, Benjamin; Gisselbrecht, Jean-Paul; Boudon, Corinne; Trapp, Nils; Schweizer, W Bernd; Diederich, François

    2015-01-16

    A convergent, multistep protocol was employed for the synthesis of a Janus-type multivalent donor-acceptor system. The synthetic approach is based on a Sonogashira cross-coupling of two differently ferrocene-(Fc) substituted dendrons and a final sixfold [2 + 2] cycloaddition-retroelectrocyclization (CA-RE) reaction with tetracyanoethene, which occurs regioselectively at only one of the rigidly linked dendrons. The structural and optoelectronic properties of the compounds were investigated by X-ray analysis, UV/vis spectroscopy, and electrochemistry. The target Janus-system displays redox-amphoteric behavior. The nonalkynylated Fc end groups in one dendron are readily and reversibly oxidized. The second dendron, in which the terminal Fc-activated alkynes underwent the CA-RE reaction to give tetracyanobuta-1,3-dienes in the final step of the synthesis, undergoes four reversible 3-e(-) reductions in the very narrow potential range of 1 V. A spontaneous intramolecular charge transfer from the donor into the acceptor hemisphere was not observed. Furthermore, the oxidation potential of the Fc donors in one hemisphere is hardly perturbed by the push-pull acceptors in the other, which suggests that electronic communication along the π-system, with several meta-connectivities, is not efficient. Therefore, the charge-transfer bands seen in the Janus-type system originate from the interaction of the Fc donors with the directly connected tetracyanobuta-1,3-diene acceptors in the same hemisphere. PMID:25489964

  16. The characterization of dielectric properties of platinum-Nafion-poly(3,4-ethylenedioxythiophene) system

    NASA Astrophysics Data System (ADS)

    Kim, Hyo-Seok

    reflected and then detected by a receiver. The time interval or frequency change between emission and detection is measured as an indicator for the distance. The purpose of this project is to conduct fundamental study into the material properties with an emphasis on polarization-related phenomena. This project specifically focuses on the power generating properties of the hybrid PNP composite device and its application. This device is a new system being applied for the first time because of its potential for generating power. The specific aspects of the devices being studied in the project encompass both macroscopic and microscopic properties of hybrid PNP composite. The microscopic properties include electrical property as measured by impedance spectroscopy and dielectric response characteristics to examine the power generating mechanism of induced polarization for PNP composite device. The produced current and power efficiency by mechanical deformation operation are compared.

  17. Electronic and Vibrational Properties of Low-Dimensional Heterogeneous Systems: Materials and Device Perspectives

    NASA Astrophysics Data System (ADS)

    Neupane, Mahesh Raj

    Due to the aggressive miniaturization of memory and logic devices, the current technologies based on silicon have nearly reached their ultimate size limit. One method to maintain the trend in device scaling observed by Moore's law is to create a heterostructure from existing materials and utilize the underlying electronic and optical properties. Another radical approach is the conceptualization of a new device design paradigm. The central objective of this thesis is to use both of these approaches to address issues associated with the aggressive scaling of memory and logic devices such as leakage current, leakage power, and minimizing gate oxide thickness and threshold voltage. In the first part of the dissertation, an atomistic, empirical tight binding method was used to perform a systematic investigation of the effect of physical (shape and size), and material dependent (heterogenity and strain) properties on the device related electronic and optical properties of the Germanium (Ge)/Silicon (Si) nanocrystal (NC) or quantum dot (QD). The device parameters pertaining to Ge-core/Si-shell NC-based floating gate memory and optical devices such as confinement energy, retention lifetimes and optical intensities are captured and analyzed. For both the memory and optical device applications, regardless of the shape and size, the Ge-core is found to play an important role in modifying the confinement energy and carrier dynamics. However, the variation in the thickness of outer Si-shell layer had no or minimal effect on the overall device parameters. In the second part of the dissertation, we present a systematic study of the effect of atomistic heterogeneity on the vibrational properties of quasi-2D systems and recently discovered 2D materials such as graphene, while investigating their applicabilities in future devices applications. At first, we investigate the vibrational properties of an experimentally observed misoriented bilayer graphene (MBG) system, a

  18. Improvement of mechanical properties of polymeric composites: Experimental methods and new systems

    NASA Astrophysics Data System (ADS)

    Nguyen, Felix Nhanchau

    Filler- (e.g., particulate or fiber) reinforced structural polymers or polymeric composites have changed the way things are made. Today, they are found, for example, in air/ground transportation vehicles, sporting goods, ballistic barrier applications and weapons, electronic packaging, musical instruments, fashion items, and more. As the demand increases, so does the desire to have not only well balanced mechanical properties, but also light weight and low cost. This leads to a constant search for novel constituents and additives, new fabrication methods and analytical techniques. To achieve new or improved composite materials requires more than the identification of the right reinforcements to be used with the right polymer matrix at the right loading. Also, an optimized adhesion between the two phases and a toughened matrix system are needed. This calls for new methods to predict, modify and assess the level of adhesion, and new developments in matrix tougheners to minimize compromises in other mechanical/thermal properties. Furthermore, structural optimization, associated with fabrication (e.g., avoidance of fiber-fiber touching or particle aggregation), and sometimes special properties, such as electrical conductivity or magnetic susceptibility are necessary. Finally, the composite system's durability, often under hostile conditions, is generally mandatory. The present study researches new predictive and experimental methods for optimizing and characterizing filler-matrix adhesion and develops a new type of epoxy tougheners. Specifically, (1) a simple thermodynamic parameter evaluated by UNIFAC is applied successfully to screen out candidate adhesion promoters, which is necessary for optimization of the physio-chemical interactions between the two phases; (2) an optical-acoustical mechanical test assisted with an acoustic emission technique is developed to de-convolute filler debonding/delamination among many other micro failure events, and (3) novel core

  19. Some physical properties predicted for the putative Planet Nine of the solar system

    NASA Astrophysics Data System (ADS)

    Toth, I.

    2016-08-01

    Context. Nothing is known as yet about the physical properties of the putative Planet Nine (P9), which is hypothesized to orbit at the fringes of the solar system. Two groups of observers are using the eight-meter Subaru telescope to search for P9. Early estimates and predictions are important to characterize this hypothetic planet. We here predict some properties to compare them with the observed physical properties when Planet Nine has been unambiguously detected comparisons between the predicted and observed physical properties. Aims: We estimate the size, apparent observable brightness, shortest rotation period, and extension of the stable orbital region of possible satellites of P9. Methods: Using the predicted mass and adopting a possible mean bulk density range of P9, we computed its radius and assumed a domain for its geometric albedo. We then determined the apparent magnitude along its elliptic orbit. By testing different plausible physical models of a sub-Neptune class planet, we estimated the regions of stability and destruction versus rotational breakup in the radius-rotational period plane. In this plane the shortest rotational period is constrained by the possible size range of P9 and the separation curves. We applied quantitative measures of the stability domain of possible satellites orbiting P9 to quantify the search region in which to find possible satellite companions of the putative trans-Neptunian giant planet of our solar system. Results: Its predicted apparent magnitude even near aphelion allows discovering P9 with eight-meter class telescopes. P9 is stable against rotational breakup for stronger material if the period is longer than ~6 h, and for weaker material if the period is longer than ~13 h. The Szebehely stability domain for possible satellites of the hypothetical P9 is very large: for a small satellite it extents to ~1.7 au from the planet, and the longest orbital period of the satellite in this orbit is ~396 yr. For a possible twin

  20. FORMATION AND EVOLUTION OF PLANETARY SYSTEMS: PROPERTIES OF DEBRIS DUST AROUND SOLAR-TYPE STARS

    SciTech Connect

    Carpenter, John M.; Hillenbrand, Lynne A.; Bouwman, Jeroen; Henning, Thomas; Wolf, Sebastian; Mamajek, Eric E.; Meyer, Michael R.; Kim, Jinyoung Serena; Pascucci, Ilaria; Backman, Dana E.; Hollenbach, David; Moro-Martin, Amaya; Silverstone, Murray D.; Stauffer, John R.

    2009-03-15

    We present Spitzer photometric (IRAC and MIPS) and spectroscopic (IRS low resolution) observations for 314 stars in the Formation and Evolution of Planetary Systems Legacy program. These data are used to investigate the properties and evolution of circumstellar dust around solar-type stars spanning ages from approximately 3 Myr-3 Gyr. We identify 46 sources that exhibit excess infrared emission above the stellar photosphere at 24 {mu}m, and 21 sources with excesses at 70 {mu}m. Five sources with an infrared excess have characteristics of optically thick primordial disks, while the remaining sources have properties akin to debris systems. The fraction of systems exhibiting a 24 {mu}m excess greater than 10.2% above the photosphere is 15% for ages < 300 Myr and declines to 2.7% for older ages. The upper envelope to the 70 {mu}m fractional luminosity appears to decline over a similar age range. The characteristic temperature of the debris inferred from the IRS spectra range between 60 and 180 K, with evidence for the presence of cooler dust to account for the strength of the 70 {mu}m excess emission. No strong correlation is found between dust temperature and stellar age. Comparison of the observational data with disk models containing a power-law distribution of silicate grains suggests that the typical inner-disk radius is {approx}> 10 AU. Although the interpretation is not unique, the lack of excess emission shortward of 16 {mu}m and the relatively flat distribution of the 24 {mu}m excess for ages {approx}< 300 Myr is consistent with steady-state collisional models.

  1. Efficient Visible-Light Photocatalytic Properties in Low-Temperature Bi-Nb-O System Photocatalysts.

    PubMed

    Zhai, Haifa; Shang, Shuying; Zheng, Liuyang; Li, Panpan; Li, Haiqin; Luo, Hongying; Kong, Jizhou

    2016-12-01

    Low-temperature Bi-Nb-O system photocatalysts were prepared by a citrate method using homemade water-soluble niobium precursors. The structures, morphologies, and optical properties of Bi-Nb-O system photocatalysts with different compositions were investigated deeply. All the Bi-Nb-O powders exhibit appreciably much higher photocatalytic efficiency of photo-degradation of methyl violet (MV), especially for Bi-Nb-O photocatalysts sintered at 750 °C (BNO750), only 1.5 h to completely decompose MV, and the obtained first-order rate constant (k) is 1.94/h. A larger degradation rate of Bi-Nb-O photocatalysts sintered at 550 °C (BNO550) can be attributed to the synergistic effect between β-BiNbO4 and Bi5Nb3O15. Bi5Nb3O15 with small particle size on β-BiNbO4 surface can effectively short the diffuse length of electron. BNO750 exhibits the best photocatalytic properties under visible-light irradiation, which can be attributed to its better crystallinity and the synergistic effect between β-BiNbO4 and α-BiNbO4. The small amount of α-BiNbO4 loading on surface of β-BiNbO4 can effectively improve the electron and hole segregation and migration. Holes are the main active species of Bi-Nb-O system photocatalysts in aqueous solution under visible-light irradiation. PMID:27576523

  2. Molecular Properties of Salmonella enterica Serotype Paratyphi B Distinguish between Its Systemic and Its Enteric Pathovars

    PubMed Central

    Prager, Rita; Rabsch, Wolfgang; Streckel, Wiebke; Voigt, Wolfgang; Tietze, Erhardt; Tschäpe, Helmut

    2003-01-01

    Salmonella enterica serotype O1,4,5,12:Hb:1,2, designated according to the current Kauffmann-White scheme as S. enterica serotype Paratyphi B, is a very diverse serotype with respect to its clinical and microbiological properties. PCR and blot techniques, which identify the presence, polymorphism, and expression of various effector protein genes, help to distinguish between strains with systemic and enteric outcomes of disease. All serotype Paratyphi B strains from systemic infections have been found to be somewhat genetically related with respect to the pattern of their virulence genes sopB, sopD, sopE1, avrA, and sptP as well as other molecular properties (multilocus enzyme electrophoresis type, pulsed-field gel electrophoresis [PFGE] type, ribotype, and IS200 type). They have been classified as members of the systemic pathovar (SPV). All these SPV strains possess a new sopE1-carrying bacteriophage (designated ΦSopE309) with high SopE1 protein expression but lack the commonly occurring avrA determinant. They exhibit normal SopB protein expression but lack SopD protein production. In contrast, strains from enteric infections classified as belonging to the enteric pathovar possess various combinations of the respective virulence genes, PFGE pattern, and ribotypes. We propose that the PCR technique for testing for the presence of the virulence genes sopE1 and avrA be used as a diagnostic tool for identifying both pathovars of S. enterica serotype Paratyphi B. This will be of great public health importance, since strains of serotype Paratyphi B have recently reemerged worldwide. PMID:12958256

  3. Toward innovative management of canal systems: determining fundamental properties governing channel flow and transport.

    NASA Astrophysics Data System (ADS)

    Swanson, L. A.; Lunn, R. J.

    2003-04-01

    This research investigates current and future influences on the water quality of canal systems with the aim of designing innovative management strategies for their improvement. The implementation of the Water Framework Directive (WFD) will be particularly significant for canals as it is the first legislation to include artificial impoundments. The WFD requires that the quality of all water bodies is characterised and that ultimately they achieve “good ecological potential”; for such engineered artificial water bodies this potential is as yet undefined. The hydraulic properties of canals are uniquely different from that of natural river systems, influencing factors of particular importance are: the extremely low flow rates (enabling flow directions to be reversed during rainfall events or high winds); the multiple overflow discharge points; the interaction with groundwater; and the regular channel dredging. These lead to unpredictable flow directions, long residence times for pollutants, a lack of rapid dispersion processes and sudden mixing of bed sediment into the water column. This research uses the Union Canal, central Scotland as a case study for fundamental research of advection-dispersion processes in artificial channels. Detailed velocity profiles and dilution gauging experiments have produced unusual results: for example, maximum velocity measurements near the bed of the canal as opposed to just beneath the surface. Research is also focused on understanding the mechanisms governing canal baseline water quality: Sampling data show low levels of DO, coupled with ortho-phosphate concentrations up to 10 times greater than those normally found in rivers. Determining the hydraulic properties of canals and understanding the origins of canal water quality are fundamental to designing improved management strategies to meet the requirements of the WFD. Results of this research, in combination with channel flow and water quality modelling, will be used to provide

  4. System Properties of Flexible Structures with Self-Sensing Piezoelectric Transducers

    NASA Astrophysics Data System (ADS)

    CARABELLI, S.; TONOLI, A.

    2000-08-01

    Active and passive implementations of self-sensing readout networks are studied in terms of system properties such as the poles and the zeros of their transfer functions. The location of the zeros is shown to be dependent on two non-dimensional parameters related to the balancing condition of the readout bridge and to the compensation of its losses, while it is not affected by the active or passive implementation of the readout bridge. In the case of ideal “loss compensation” a graphical procedure is employed to describe the migration of the zeros. Even if the self-sensing arrangement guarantees the colocation of the sensing and actuating functions, the graphical procedure shows the possibility of non-minimum phase zero coupls for balancing conditions close to the so-called “electrical balancing”. The effects of model reduction techniques such as truncation or residualization is then studied, starting from a model of the system in terms of modal coordinates. Truncation is shown to be better suited to determine the “electrical balancing” condition while residualization gives a better approximation of the system zeros. The conditions of electrical balancing and loss compensation are then related to a condition of minimum dependance of the self-sensing bridge output from the driving electrical input. This property can be practically exploited to devise an adaptive readout bridge which can automatically reach the balancing conditions and the loss compensation or to identify the electrical parameters of the piezoelectric transducer. Experimental tests performed on a beam and a plate structures provided with self-sensing piezoelectric transducers are used to validate the analytical models.

  5. Cryogenic Property Measurements on Icy Compositions with Application to Solar System Ices

    NASA Astrophysics Data System (ADS)

    Hays, C.; Castillo-Rogez, J.; Barmatz, M.; Mitchell, K.

    2007-08-01

    grains). Post-synthesis microstructural characterization will be performed using Cryogenic Optical Microscopy integrating a cross-polarizer to analyze thin sections, and a Cryogenic Scanning Electron Microscope. Mechanical property measurements on solid specimens will be performed between 80 and 270 K with a cryogenically cooled Instron measurement system. Compression measurements will be conducted as a function of temperature, strain-rate, microstructural length scale and orientation. The time dependent viscous response will be measured by performing creep measurements over the same range of temperatures. Using low-frequency cyclic loading, the dissipation factor will be measured at frequencies approaching satellite orbital frequencies. We will report preliminary mechanical property measurements of Antarctic glacial specimens at cryogenic temperatures. Fluids. In order to improve our understanding of effusive cryovolcanism, the rheological properties of liquid and mixed (slurry) materials will be measured between 80 and 300 K using a cryogenically cooled Brookfield rotational rheometer. We will report preliminary measurements of the temperature dependence of the viscous response for several compositions in the Methanol-Water System. Also, we will describe an experiment designed to measure methane wetting on water ice. These experiments will be carried out in order to explore the effects of the presence of methane lakes on Titan's surface. We are developing the capability to investigate more complex materials relevant to surface processes on Titan, including methane-ethane phase studies, hydrocarbons such as acetylene and benzene, as well as tholins and clathrates, which should exhibit a range of rheological and mechanical properties from fast-moving fluids to glacial creep. Acknowledgements: Most of the research described in this presentation was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National

  6. Novel compounds in the Zr-O system, their crystal structures and mechanical properties.

    PubMed

    Zhang, Jin; Oganov, Artem R; Li, Xinfeng; Dong, Huafeng; Zeng, Qingfeng

    2015-07-14

    With the motivation of exploring new high-strength ceramics, ab initio evolutionary simulations are performed to search for all the stable compounds in the Zr-O system. We have found that not only the traditional compound ZrO2, but also the ordered suboxides R3̅-Zr6O, R3̅c-Zr3O, P3̅1m-Zr2O and P6̅2m-ZrO are stable at zero pressure. The crystal structure of semimetallic P6̅2m-ZrO consists of Zr-graphene layers and can be described as an intercalated version of the ω-Zr structure. An interesting massive Dirac cone is found in the three-dimensional (3D) band structure of P6̅2m-ZrO at the Γ-point. The elastic properties, the hardness and the correlation between the mechanical properties of Zr-O compounds and the oxygen content have been systematically investigated. Surprisingly, the hardest zirconium oxide is not ZrO2, but ZrO. Both P6̅2m-ZrO and P3̅1m-Zr2O exhibit relatively high hardness values of 14 GPa and 10 GPa, respectively. The anisotropic Young's modulus E, torsion shear modulus Gt and linear compressibility β have been derived for P6̅2m-ZrO and P3̅1m-Zr2O. Further analyses of the density of states, the band structure and the crystal orbital Hamilton population indicate that the electronic structure of Zr-O compounds is directly related to their mechanical properties. The simultaneous occurrence of the 3D-framework of Zr-O and the strong Zr-Zr bonds in P6̅2m-ZrO explains its high hardness. PMID:26073292

  7. Thermal Properties of West Siberian Sediments in Application to Basin and Petroleum Systems Modeling

    NASA Astrophysics Data System (ADS)

    Romushkevich, Raisa; Popov, Evgeny; Popov, Yury; Chekhonin, Evgeny; Myasnikov, Artem; Kazak, Andrey; Belenkaya, Irina; Zagranovskaya, Dzhuliya

    2016-04-01

    Quality of heat flow and rock thermal property data is the crucial question in basin and petroleum system modeling. A number of significant deviations in thermal conductivity values were observed during our integral geothermal study of West Siberian platform reporting that the corrections should be carried out in basin models. The experimental data including thermal anisotropy and heterogeneity measurements were obtained along of more than 15 000 core samples and about 4 500 core plugs. The measurements were performed in 1993-2015 with the optical scanning technique within the Continental Super-Deep Drilling Program (Russia) for scientific super-deep well Tyumenskaya SG-6, parametric super-deep well Yen-Yakhinskaya, and deep well Yarudeyskaya-38 as well as for 13 oil and gas fields in the West Siberia. Variations of the thermal conductivity tensor components in parallel and perpendicular direction to the layer stratification (assessed for 2D anisotropy model of the rock studied), volumetric heat capacity and thermal anisotropy coefficient values and average values of the thermal properties were the subject of statistical analysis for the uppermost deposits aged by: T3-J2 (200-165 Ma); J2-J3 (165-150 Ma); J3 (150-145 Ma); K1 (145-136 Ma); K1 (136-125 Ma); K1-K2 (125-94 Ma); K2-Pg+Ng+Q (94-0 Ma). Uncertainties caused by deviations of thermal conductivity data from its average values were found to be as high as 45 % leading to unexpected errors in the basin heat flow determinations. Also, the essential spatial-temporal variations in the thermal rock properties in the study area is proposed to be taken into account in thermo-hydrodynamic modeling of hydrocarbon recovery with thermal methods. The research work was done with financial support of the Russian Ministry of Education and Science (unique identification number RFMEFI58114X0008).

  8. Structure, attachment properties, and ecological importance of the attachment system of English ivy (Hedera helix)

    PubMed Central

    Melzer, Björn; Seidel, Robin; Steinbrecher, Tina; Speck, Thomas

    2012-01-01

    Root climbers such as English ivy (Hedera helix) rely on specialized adventitious roots for attachment, enabling the plants to climb on a wide range of natural and artificial substrates. Despite their importance for the climbing habit, the biomechanical properties of these specialized adventitious roots compared with standard roots and their performance in the attachment to different host species or inert substrates have not been studied. Here organs and tissues involved in the attachment are characterized and their significance in regard to a broader functional and ecological aspect is discussed. Depending on the substrate, the root clusters show different types of failure modes at various frequencies, demonstrating the close interaction between the climber and its substrates. With a Young’s Modulus of 109.2 MPa, the attachment roots are relatively stiff for non-woody roots. The central cylinders of the attachment roots show a high tensile strength of 38 MPa and a very high extensibility of 34%. In host trees naturally co-distributed with English ivy, a ‘balanced’ occurrence of failure of the attachment system of the climber and the bark of the host is found, suggesting a co-evolution of climber and host. Maximum loads of root clusters normalized by the number of roots match those of individually tested attachment roots. In comparison with most subterranean roots the properties and structure of the attachment roots of English ivy show distinct differences. There exist similarities to the properties found for roots of Galium aparine, suggesting a trend in not fully self-supporting plants towards a higher extensibility. PMID:21914660

  9. Quantifying mechanical properties in a murine fracture healing system using inverse modeling: preliminary work

    NASA Astrophysics Data System (ADS)

    Miga, Michael I.; Weis, Jared A.; Granero-Molto, Froilan; Spagnoli, Anna

    2010-03-01

    Understanding bone remodeling and mechanical property characteristics is important for assessing treatments to accelerate healing or in developing diagnostics to evaluate successful return to function. The murine system whereby mid-diaphaseal tibia fractures are imparted on the subject and fracture healing is assessed at different time points and under different therapeutic conditions is a particularly useful model to study. In this work, a novel inverse geometric nonlinear elasticity modeling framework is proposed that can reconstruct multiple mechanical properties from uniaxial testing data. To test this framework, the Lame' constants were reconstructed within the context of a murine cohort (n=6) where there were no differences in treatment post tibia fracture except that half of the mice were allowed to heal 4 days longer (10 day, and 14 day healing time point, respectively). The properties reconstructed were a shear modulus of G=511.2 +/- 295.6 kPa, and 833.3+/- 352.3 kPa for the 10 day, and 14 day time points respectively. The second Lame' constant reconstructed at λ=1002.9 +/-42.9 kPa, and 14893.7 +/- 863.3 kPa for the 10 day, and 14 day time points respectively. An unpaired Student t-test was used to test for statistically significant differences among the groups. While the shear modulus did not meet our criteria for significance, the second Lame' constant did at a value p<0.0001. Traditional metrics that are commonly used within the bone fracture healing research community were not found to be statistically significant.

  10. The Physical Properties of the Damped Lyα Systems: A Keck HIRES Investigation

    NASA Astrophysics Data System (ADS)

    Prochaska, Jason Xavier

    1998-10-01

    Studying the damped Lyα systems is one of the most efficient methods for probing the physical nature of protogalaxies in the early universe. In turn, this research has direct implications for theories on galaxy formation and cosmology. In this thesis, we present results from several studies on the physical properties of the damped Lyα systems. In particular, we focus on the chemical abundances and kinematic characteristics of the damped systems with observations taken with HIRES on the 10m W. M. Keck Telescope. Among the principle results reported in this manuscript are: (1) the damped Lyα systems are predominantly neutral, (2) the low-ion profiles trace one another very closely in velocity space, (3) the low-ion profiles are kinematically disjoint from the high-ion profiles implying distinct physical origins for the two species, (4) the damped Lyα systems exhibit abundance patterns consistent with a Type II supernovae enrichment, with the major exception of Zn and Ni which argue for the presence of dust, (5) the metallicity of the sample of damped Lyα systems considered here shows a column density-weighted mean [ ]/ = -1.01 dex and [ ]/ = -1.52 dex for z = 1.5-3 and []/ = -1.80 dex for z > 3, (6) the low-ion profiles exhibit a distribution of velocity widths from ≈20-300 km s-1, (7) the majority of the low-ion profiles have an edge-leading asymmetric profile shape, (8) the kinematics of the damped Lyα systems are consistent with those predicted for a single population of thick, rapidly (vrot ≈ 250 km s-1) rotating disks, (9) the kinematics are inconsistent with the standard CDM cosmology if one assumes the damped Lyα systems are centrifugally supported disks at high redshift. Two resolutions of this discrepancy are (i) the damped Lyα systems are merging protogalactic clumps or (ii) the standard cosmology is wrong as the correct one must account for the presence of rapidly rotating disk galaxies at very high redshift (z ≈ 3).

  11. Roles of Wind Shear at Different Vertical Levels, Part I: Cloud System Organization and Properties

    SciTech Connect

    Chen, Qian; Fan, Jiwen; Hagos, Samson M.; Gustafson, William I.; Berg, Larry K.

    2015-07-16

    Understanding of critical processes that contribute to the organization of mesoscale convective systems is important for accurate weather forecast and climate prediction. In this study, we investigate the effects of wind shear at different vertical levels on the organization and properties of cloud systems using the Weather Research & Forecasting (WRF) model with a spectral-bin microphysical scheme. The sensitivity experiments are performed by increasing wind shear at the lower (0-5 km), middle (5-10 km), upper (> 10 km) and the entire troposphere, respectively, based on a control run for a mesoscale convective system (MCS) with weak wind shear. We find that increasing wind shear at the both lower and middle vertical levels reduces the domain-accumulated precipitation and the occurrence of heavy rain, while increasing wind shear at the upper levels changes little on precipitation. Although increasing wind shear at the lower-levels is favorable for a more organized quasi-line system which leads to enlarged updraft core area, and enhanced updraft velocities and vertical mass fluxes, the precipitation is still reduced by 18.6% compared with the control run due to stronger rain evaporation induced by the low-level wind shear. Strong wind shear in the middle levels only produces a strong super-cell over a narrow area, leading to 67.3% reduction of precipitation over the domain. By increasing wind shear at the upper levels only, the organization of the convection is not changed much, but the increased cloudiness at the upper-levels leads to stronger surface cooling and then stabilizes the atmosphere and weakens the convection. When strong wind shear exists over the entire vertical profile, a deep dry layer (2-9 km) is produced and convection is severely suppressed. There are fewer very-high (cloud top height (CTH) > 15 km) and very-deep (cloud thickness > 15 km) clouds, and the precipitation is only about 11.8% of the control run. The changes in cloud microphysical

  12. Investigation on electronic, mechanical and thermal properties of Hf-H system

    NASA Astrophysics Data System (ADS)

    Wang, Hao; Konashi, Kenji

    2013-11-01

    Hf hydride is proposed to be used as neutron control materials for fast reactors. The electronic, mechanical and thermal properties of its three phases: δ‧-HfH1.5, δ-HfH1.75, ε-HfH2, are investigated. Their relative stabilities at 0 K by our calculation are consistent with the explanation of Jahn-Teller mechanism. The mechanical properties like elastic constants are calculated and agree well with the experiments. At finite temperatures, in addition to the direct method for phonon calculation, electronic free energy is also calculated in order to investigate the thermal expansion and bulk moduli of three phases. Hf-H system has an increasing relationship in bulk moduli with respect to the H concentration before about 360 K, after which ε-HfH2 seems to decrease more quickly in the softness of the structure than δ-HfH1.75 as the temperature increases. The relation between heat capacity and Hf and H atoms vibration is discussed.

  13. The Psychometric Properties of Classroom Response System Data: A Case Study

    NASA Astrophysics Data System (ADS)

    Kortemeyer, Gerd

    2016-03-01

    Classroom response systems (often referred to as "clickers") have slowly gained adoption over the recent decade; however, critics frequently doubt their pedagogical value starting with the validity of the gathered responses: There is concern that students simply "click" random answers. This case study looks at different measures of response reliability, starting from a global look at correlations between formative clicker responses and summative examination performance to how clicker questions are used in context. It was found that clicker performance is a moderate indicator of course performance as a whole, and that while the psychometric properties of clicker items are more erratic than those of examination data, they still have acceptable internal consistency and include items with high discrimination. It was also found that clicker responses and item properties do provide highly meaningful feedback within a lecture context, i.e., when their position and function within lecture sessions are taken into consideration. Within this framework, conceptual questions provide measurably more meaningful feedback than items that require calculations.

  14. Polymers for use in controlled release systems: the effect of surfactants on their swelling properties.

    PubMed

    Vlachou, M; Hani, N; Efentakis, M; Tarantili, P A; Andreopoulos, A G

    2000-07-01

    The effect of an ampholytic surfactant on the swelling properties of polymeric materials was studied, using various swelling liquids. Tablets were prepared consisting of hydroxypropyl methylcellulose, poly(oxyethylene) and sodium alginate. Tego betain was the non-ionic surfactant used as an additive in a series of samples made of the above polymers. Those tablets were immersed in distilled water, phosphate buffer and 0.1 N HCl, and their weight uptake was recorded as a function of time, in order to assess the swelling process. Measurements of the contact angle of the above systems were also carried out for estimating their wetting properties. The results of this study showed a selectivity among polymers, surfactant and surrounding liquid. Clearly, an enhancement of the swelling capacity of hydroxypropyl methylcellulose tablets due to the surfactant was recorded. An unclear effect was observed in the case of poly(oxyethylene), whereas for sodium alginate, the dominant factor is its water solubility that controls swelling behaviour. PMID:10972160

  15. Pressure dependence of fluid transport properties of shallow fault systems in the Nankai subduction zone

    NASA Astrophysics Data System (ADS)

    Tanikawa, Wataru; Mukoyoshi, Hideki; Lin, Weiren; Hirose, Takehiro; Tsutsumi, Akito

    2014-12-01

    We measured fluid transport properties at an effective pressure of 40 MPa in core samples of sediments and fault rocks collected by the Integrated Ocean Drilling Program (IODP) NanTroSEIZE drilling project Expedition 316 from the megasplay fault system (site C0004) and the frontal thrust (site C0007) in the Nankai subduction zone. Permeability decreased with effective pressure as a power law function. Permeability values in the fault zones were 8 × 10-18 m2 at site C0004 and 9 × 10-18 m2 at site C0007. Stratigraphic variation in transport properties suggests that the megasplay fault zone may act as a barrier to fluid flow, but the frontal thrust fault zone might not. Depth variation in permeability at site C0007 is probably controlled by the mechanical compaction of sediment. Hydraulic diffusivity at shallow depths was approximately 1 × 10-6 m2 s-1 in both fault zones, which is small enough to lead to pore pressure generation that can cause dynamic fault weakening. However, absence of a very low permeable zone, which may have formed in the Japan Trench subduction zone, might prevent facilitation of huge shallow slips during Nankai subduction zone earthquakes. Porosity tests under dry conditions might have overestimated the porosity.

  16. A method for investigating system matrix properties in optimization-based CT reconstruction

    NASA Astrophysics Data System (ADS)

    Rose, Sean D.; Sidky, Emil Y.; Pan, Xiaochuan

    2016-04-01

    Optimization-based iterative reconstruction methods have shown much promise for a variety of applications in X-ray computed tomography (CT). In these reconstruction methods, the X-ray measurement is modeled as a linear mapping from a finite-dimensional image space to a finite dimensional data-space. This mapping is dependent on a number of factors including the basis functions used for image representation1 and the method by which the matrix representing this mapping is generated.2 Understanding the properties of this linear mapping and how it depends on our choice of parameters is fundamental to optimization-based reconstruction. In this work, we confine our attention to a pixel basis and propose a method to investigate the effect of pixel size in optimization-based reconstruction. The proposed method provides insight into the tradeoff between higher resolution image representation and matrix conditioning. We demonstrate this method for a particular breast CT system geometry. We find that the images obtained from accurate solution of a least squares reconstruction optimization problem have high sensitivity to pixel size within certain regimes. We propose two methods by which this sensitivity can be reduced and demonstrate their efficacy. Our results indicate that the choice of pixel size in optimization-based reconstruction can have great impact on the quality of the reconstructed image, and that understanding the properties of the linear mapping modeling the X-ray measurement can help guide us with this choice.

  17. Dual-aureole and sun spectrometer system for airborne measurements of aerosol optical properties.

    PubMed

    Zieger, Paul; Ruhtz, Thomas; Preusker, Rene; Fischer, Jürgen

    2007-12-10

    We have designed an airborne spectrometer system for the simultaneous measurement of the direct sun irradiance and the aureole radiance in two different solid angles. The high-resolution spectral radiation measurements are used to derive vertical profiles of aerosol optical properties. Combined measurements in two solid angles provide better information about the aerosol type without additional and elaborate measuring geometries. It is even possible to discriminate between absorbing and nonabsorbing aerosol types. Furthermore, they allow to apply additional calibration methods and simplify the detection of contaminated data (e.g., by thin cirrus clouds). For the characterization of the detected aerosol type a new index is introduced that is the slope of the aerosol phase function in the forward scattering region. The instrumentation is a flexible modular setup, which has already been successfully applied in airborne and ground-based field campaigns. We describe the setup as well as the calibration of the instrument. In addition, example vertical profiles of aerosol optical properties--including the aureole measurements--are shown and discussed. PMID:18071387

  18. The Psychometric Properties of Classroom Response System Data: A Case Study

    NASA Astrophysics Data System (ADS)

    Kortemeyer, Gerd

    2016-08-01

    Classroom response systems (often referred to as "clickers") have slowly gained adoption over the recent decade; however, critics frequently doubt their pedagogical value starting with the validity of the gathered responses: There is concern that students simply "click" random answers. This case study looks at different measures of response reliability, starting from a global look at correlations between formative clicker responses and summative examination performance to how clicker questions are used in context. It was found that clicker performance is a moderate indicator of course performance as a whole, and that while the psychometric properties of clicker items are more erratic than those of examination data, they still have acceptable internal consistency and include items with high discrimination. It was also found that clicker responses and item properties do provide highly meaningful feedback within a lecture context, i.e., when their position and function within lecture sessions are taken into consideration. Within this framework, conceptual questions provide measurably more meaningful feedback than items that require calculations.

  19. Low-level chemiluminescent analysis of nondiluted human blood reveals its dynamic system properties

    NASA Astrophysics Data System (ADS)

    Voeikov, Vladimir L.; Novikov, Cyril N.; Vilenskaya, Natalia D.

    1999-01-01

    Lucigenin- and luminol-dependent chemiluminescence [(LC- CL) and (LM-CL)] in nondiluted human blood was studied. LM-CL was low in fresh blood and disappeared after its storage for 3 h, though the respiratory burst (RB) stimulated in blood was followed by high intensity and long- lasting LM-CL. LC-CL was high in fresh blood and was steadily increasing with blood storage. Blood dilution with saline resulted in LC-CL attenuation and LM-CL elevation. LC-CL did not depend on air supply to blood, while LM-CL elevation during RB needed constant blood aeration. The results suggest that besides a well-known mechanism of reactive oxygen species production by neutrophils during RB, another process of electron excited state generation reflected by LC-CL operates in blood. It needs blood integrity for its manifestation and uses oxygen supplied by erythrocytes. Dynamic system properties of blood were revealed also in experiments with blood transfer from one sample to another in the course of RB. Highly nonlinear changes of CL intensity both in a `donor' and in a `recipient' sample resulted in strong differences in CL levels in two samples, one of which was prepared by blood subtraction, and another by blood addition. We suggest that CL data from measurements on nondiluted blood may be informative of integrative properties of blood tissue in addition to its being a measure of some sort of oxidative metabolism in it.

  20. Simulation study of mechanical properties of bulk metallic glass systems: martensitic inclusions and twinned precipitates

    NASA Astrophysics Data System (ADS)

    Zaheri, A.; Abdeljawad, F.; Haataja, M.

    2014-12-01

    Monolithic bulk metallic glasses (BMGs) exhibit a unique combination of mechanical properties, such as high strength and large elasticity limits, but the lack of ductility is considered the main Achilles' heel of BMG systems. To increase the competitiveness of BMGs vis-à-vis conventional structural materials, the problem of catastrophic failure via intense plastic strain localization (‘shear banding’) has to be addressed. Recent experimental observations suggest that the addition of structural heterogeneities, in the form of crystalline particles, to BMG systems hinders the catastrophic propagation of shear bands and leads to enhanced ductility. These structural heterogeneities can be introduced by either forming BMG composites, where second-phase crystalline particles accommodate applied loads via martensitic transformation mechanisms, or developing glassy alloys that precipitate crystalline particles under deformation, a process by which further deformation can be sustained by twinning mechanisms in the crystalline phase. In this work, we present a non-linear continuum model capable of capturing the structural heterogeneity in the glassy phase and accounting for intrinsic work hardening via martensitic transformations in second-phase reinforcements in BMG composites and deformation twinning in precipitated crystalline particles. Simulation results reveal that in addition to intrinsic work hardening in the crystalline phase, particle size greatly affects the overall mechanical behavior of these BMG systems. The precipitation of crystalline particles in monolithic BMGs yields two-phase microstructures that promote more homogeneous deformation, delay the propagation of incipient shear bands, and ultimately result in improved ductility characteristics.

  1. Shear/compressive properties of candidate ITER insulation systems at low temperatures

    NASA Astrophysics Data System (ADS)

    Fabian, P. E.; Reed, R. P.; Schutz, J. B.; Bauer-McDaniel, T. S.

    Shear/compression tests were performed at 76 and 4 K on candidate composite insulation systems for the International Thermonuclear Experimental Reactor (ITER) toroidal field coils. The insulation systems tested consisted of vacuum-pressure impregnated, pre-impregnated, and high-pressure laminate systems that included electrical barriers such as polyimide film or mica/glass. Sandwich-style specimens, in which the composite insulation is bonded to two AISI 316 stainless steel chips, were used. Two specimens were loaded at an angle, which resulted in combined shear and compressive stresses, and tested simultaneously. Various shear/compression ratios were achieved by using different test fixtures, each at a different angle (15 °, 45 °, 75 ° and 84 °) from the vertical direction. The shear strengths of specimens loaded at 15 ° to 75 ° increased with increasing compressive stress; these specimens experienced shear failures. For specimens loaded at 84 °, the compressive stress increased and the shear strength decreased; the failure modes of these specimens were more compressive than shear. The effects of electrical barriers on shear/compressive properties are also reported.

  2. Practical Electrode System for EHD Liquid Jet Generation and Properties of Liquid Pumping

    NASA Astrophysics Data System (ADS)

    Hanaoka, Ryoichi; Hosodani, Naoki; Takahashi, Ichiro; Takata, Shinzo; Fukami, Tadashi

    The coaxial cone to rod electrode system was devised to generate a powerful electrohydrodynamic (EHD) liquid jet and the performance as a liquid pump was investigated using an isothermal weakly conducting liquid, HFC43-10. When a positive dc voltage was applied to the rod electrode, the liquid spouted forcibly from the glass tube outlet installed in the top of grounded conical electrode. The properties of liquid jet: pumping pressure, flow velocity and flow pattern were examined for the electrode systems with various cone angles (θ =40°∼90°) of the conical electrode. The potential distribution in the electrode gap and the conduction current also were measured as a function of applied voltage. In this paper, it is shown that the pumping pressure is almost independent of the cone angle of electrode systems as well as the flow velocity, but is raised effectively by a partial insulating coating of rod electrode surface and the current is reduced by a coating. The potential distribution in the gap revealed the existence of heterocharge layer in the vicinity of the electrode surfaces. It is considered that the EHD pumping in this study is attributed to a space charge layer with single ionic polarity near the rod electrode, which is formed by a non-uniform electric field.

  3. The influence of chitosan on the structural properties of whey protein and wheat starch composite systems.

    PubMed

    Yang, Natasha; Ashton, John; Kasapis, Stefan

    2015-07-15

    The structural properties of medium molecular weight chitosan (CHT), whey protein isolate (WPI) and native wheat starch (WS) from low- to intermediate-solid single systems and composite matrices were investigated. Analysis involved monitoring the thermal behavior of these biopolymers during controlled heating from 25 up to 95 °C and subsequent cooling to 5 °C under small deformation dynamic oscillation in-shear and micro differential scanning calorimetry experiments. Further information regarding the molecular interactions of components and overall network morphology of the systems was revealed through subjecting thermally developed gels to large deformation compression testing, scanning electron microscopy and infrared spectroscopy. Our study found a significant change in the structure of WPI networks upon incorporation of CHT in preparations due to electrostatic forces developing between the two polymeric constituents. In the tertiary system, the presence of low levels of starch contributed to a reduction in the firmness of the gel matrix. However, at higher additions of the polysaccharide, a recovery in the stored energy of composite materials was apparent, as recorded in the thermomechanical protocol. PMID:25722139

  4. Composition dependences of thermodynamical properties associated with Pb-free ternary, quaternary, and quinary solder systems

    NASA Astrophysics Data System (ADS)

    Dogan, A.; Arslan, H.

    2016-05-01

    In the present study, Chou's General Solution Model (GSM) has been used to predict the enthalpy and partial enthalpies of mixing of the liquid Ag-In-Sn ternary, Ag-In-Sn-Zn quaternary, and Ag-Au-In-Sn-Zn quinary systems. These are of technical importance to optimize lead-free solder alloys, in selected cross-sections: x In/ x Sn = 0.5/0.5 (ternary), Au-In0.1-Sn0.8-Zn0.1, Ag-In0.1-Sn0.8-Zn0.1 (quaternary), and t = x Au/ x In = 1, x In = x Sn = x Zn (quinary) at 1173, 773, and 773 K, respectively. Moreover, the activity of In content in the ternary alloy system Ag-In-Sn has been calculated and its result is compared with that determined from the experiment, while the activities of Ag contents associated with the alloys mentioned above have been calculated. The other traditional models such as of Colinet, Kohler, Muggianu, Toop, and Hillert are also included in calculations. Comparing those calculated from the proposed GSM with those determined from experimental measurements, it is seen that this model becomes considerably realistic in computerization for estimating thermodynamic properties in multicomponent systems.

  5. A non-contacting vertical alignment system for mass properties measuring instruments

    SciTech Connect

    James, G.H. III; Suazo, J.E.; Varga, R.C.

    1993-11-01

    A non-contact system for alignment of objects on mass properties measuring instruments is described. Test parts can be aligned to within the capabilities of the user and the fixture to make the adjustments. The current implementation can align objects to less than .001 inches at two points with final requested adjustments of a few ten-thousands of an inch. The non-contact capability allows the alignment of objects which are too compliant or fragile for traditional contacting measurement methods. Also, this system allows the definition of a reference axis on objects which are not perfectly symmetric. The reference axis is defined at the top of the object by an appropriate marker and defined at the bottom by a best fit circle through the surface at a specified height. A general description of the hardware, procedures, and results are presented for the non-user. Appendices which contain a complete description of the software, usage, and mathematical implementation are provided for the reader who is interested in using or further developing the system.

  6. Chandra Studies of the X-ray gas properties of fossil systems

    NASA Astrophysics Data System (ADS)

    Qin, Zhen-Zhen

    2016-03-01

    We study ten galaxy groups and clusters suggested in the literature to be “fossil systems (FSs)” based on Chandra observations. According to the M500 - T and LX - T relations, the gas properties of FSs are not physically distinct from ordinary galaxy groups or clusters. We also first study the fgas, 2500 - T relation and find that the FSs exhibit the same trend as ordinary systems. The gas densities of FSs within 0.1r200 are ˜ 10-3 cm-3, which is the same order of magnitude as galaxy clusters. The entropies within 01r200 (S0.1r200) of FSs are systematically lower than those inordinary galaxy groups, which is consistent with previous reports, but we find their S0.1r200 - T relation is more similar to galaxy clusters. The derived mass profiles of FSs are consistent with the Navarro, Frenk and White model in (0.1 - 1)r200, and the relation between scale radius rs and characteristic mass density δc indicates self-similarity of dark matter halos of FSs. The ranges of rs and δc for FSs are also close to those of galaxy clusters. Therefore, FSs share more common characteristics with galaxy clusters. The special birth place of the FS makes it a distinct type of galaxy system.

  7. Towards safer, better healthcare: harnessing the natural properties of complex sociotechnical systems

    PubMed Central

    Braithwaite, J; Runciman, W B; Merry, A F

    2009-01-01

    Objectives: To sustain an argument that harnessing the natural properties of sociotechnical systems is necessary to promote safer, better healthcare. Methods: Triangulated analyses of discrete literature sources, particularly drawing on those from mathematics, sociology, marketing science and psychology. Results: Progress involves the use of natural networks and exploiting features such as their scale-free and small world nature, as well as characteristics of group dynamics like natural appeal (stickiness) and propagation (tipping points). The agenda for change should be set by prioritising problems in natural categories, addressed by groups who self select on the basis of their natural interest in the areas in question, and who set clinical standards and develop tools, the use of which should be monitored by peers. This approach will facilitate the evidence-based practice that most agree is now overdue, but which has not yet been realised by the application of conventional methods. Conclusion: A key to health system transformation may lie under-recognised under our noses, and involves exploiting the naturally-occurring characteristics of complex systems. Current strategies to address healthcare problems are insufficient. Clinicians work best when their expertise is mobilised, and they flourish in groupings of their own interests and preference. Being invited, empowered and nurtured rather than directed, micro-managed and controlled through a hierarchy is preferable. PMID:19204130

  8. ORBITAL AND PHYSICAL PROPERTIES OF THE σ Ori Aa, Ab, B TRIPLE SYSTEM

    SciTech Connect

    Simón-Díaz, S.; Caballero, J. A.; Apellániz, J. Maíz; Lorenzo, J.; Negueruela, I.; Dorda, R.; Marco, A.; Schneider, F. R. N.; Barbá, R. H.; Montes, D.; Pellerin, A.; Sanchez-Bermudez, J.; Sota, A.

    2015-02-01

    We provide a complete characterization of the astrophysical properties of the σ Ori Aa, Ab, B hierarchical triple system and an improved set of orbital parameters for the highly eccentric σ Ori Aa, Ab spectroscopic binary. We compiled a spectroscopic data set comprising 90 high-resolution spectra covering a total time span of 1963 days. We applied the Lehman-Filhés method for a detailed orbital analysis of the radial velocity curves and performed a combined quantitative spectroscopic analysis of the σ Ori Aa, Ab, B system by means of the stellar atmosphere code FASTWIND. We used our own plus other available information on photometry and distance to the system for measuring the radii, luminosities, and spectroscopic masses of the three components. We also inferred evolutionary masses and stellar ages using the Bayesian code BONNSAI. The orbital analysis of the new radial velocity curves led to a very accurate orbital solution of the σ Ori Aa, Ab pair. We provided indirect arguments indicating that σ Ori B is a fast-rotating early B dwarf. The FASTWIND+BONNSAI analysis showed that the Aa, Ab pair contains the hottest and most massive components of the triple system while σ Ori B is a bit cooler and less massive. The derived stellar ages of the inner pair are intriguingly younger than the one widely accepted for the σ Orionis cluster, at 3 ± 1 Ma. The outcome of this study will be of key importance for a precise determination of the distance to the σ Orionis cluster, the interpretation of the strong X-ray emission detected for σ Ori Aa, Ab, B, and the investigation of the formation and evolution of multiple massive stellar systems and substellar objects.

  9. Optical-response properties in levitated optomechanical systems beyond the low-excitation limit

    NASA Astrophysics Data System (ADS)

    Nie, Wenjie; Chen, Aixi; Lan, Yueheng

    2016-02-01

    We investigate the optical-response properties of a levitated optomechanical cavity coupled to a higher order excited atomic medium. The cavity field driven through the atom-field interaction is responsible for trapping a dielectric nanosphere, whose steady-state position is biased by the Coulomb force between the nanosphere and the cavity wall. We show that the phenomena of optomechanically induced transparency (OMIT) and amplification can be generated from the output probe field in the presence of an effective optomechanical coupling between the nanosphere and the cavity field. Further, the width of the transparency window increases with increasing strength of the effective optomechanical coupling, which is controlled easily by varying the Coulomb interaction and the radius of the nanosphere. In particular, when the higher order excitation of the atomic medium is included, a large driving of the atomic ensemble but a relatively small atom-field detuning can be applied to help observe the OMIT behavior in the hybrid system.

  10. Charge properties of the hadronic system in vp and overlineν p interactions

    NASA Astrophysics Data System (ADS)

    Allen, P.; Grässler, H.; Lanske, D.; Schulte, R.; Böckmann, K.; Geich-Gimbel, C.; Nellen, B.; Saarikko, H.; Bosetti, P.; Cocconi, V. T.; Grant, A.; Hulth, P. O.; Klein, H.; Morrison, D. R. O.; Peyrou, Ch.; Schmid, P.; Sliwa, K.; Wachsmuth, H.; Aderholz, M.; Coghen, T.; Schmitz, N.; Settles, R.; Steinfeld, P.; Wernhard, K. L.; Wittek, W.; Batley, R.; Myatt, G.; Saitta, B.; Aachen-Bonn-CERN-München(MPI)-Oxford Collaboration

    1982-04-01

    Charge properties of the hadronic systems from νp and overlineνp scattering in BEBC are studied in the framework of the quark-parto model (QPM). The average charges

  11. Compositional dependence of physical properties in Se-Sb-In glassy system

    SciTech Connect

    Sharma, Shaveta Sharma, Rita; Kumar, Praveen; Chander, Ravi; Thangaraj, R.; Mian, M.

    2015-08-28

    The growing interest in the investigation of the properties of chalcogenide glasses stems from their potential application as phase change recording media and photoconductive elements in solid state devices.In the present work, the different theoretical parameters viz. coordination number, constraints, number of lone pair electrons, bond energy, heat of atomization, mean bond energy and glass transition temperature for Se{sub 75-x}Sb{sub 25}In{sub x} (x= 0, 1, 3, 5, 7, 9, 11) chalcogenide system have been calculated and their composition variation has been discussed. It has been found that average heat of atomization increases with In content. The glass transition temperature and mean bond energy increases with In. An attempt has been made to explain the varying trend of various parameters with increasing In content.

  12. Monitoring Aerosol Optical Properties in the ABL, Using Lidar System and Sunphotometer in Buenos Aires, Argentina

    NASA Astrophysics Data System (ADS)

    Pallotta, J.; Pawelko, E.; Otero, L.; Ristori, P.; D'Elia, R.; Gonzalez, F.; Dworniczak, J.; Vilar, O.; Quel, E.

    2009-03-01

    At the Lasers and Applications Research Center (CEILAP, CITEFA-CONICET, (34°33' S, 58°30' W), located in an industrial suburb of the metropolitan area (Villa Martelli, Buenos Aires, Argentina), operates a multiwavelength lidar, based on a Nd:Yag laser (Continuum Surelite III P-IV). This system emits in 1064, 532 and 355 nm simultaneously (10 Hz, 600 mJ @ 1064 nm) and allows the monitoring of the optical aerosols properties in the atmospheric boundary layer (ABL). On the same experimental site, an AERONET sunphotometer provides the AOT value. An analysis of boundary layer behaviour in some relevant days of March, from the years 2004 to 2006 is presented. On the days analyzed, no aerosols events and clouds were registered over the ABL. Evolutions of some characteristics of the ABL are presented, such as the height of the boundary layer, height of entrainment zone (EZ) and the entrainment flux ratio.

  13. Thermosetting epoxy resin/thermoplastic system with combined shape memory and self-healing properties

    NASA Astrophysics Data System (ADS)

    Yao, Yongtao; Wang, Jingjie; Lu, Haibao; Xu, Ben; Fu, Yongqing; Liu, Yanju; Leng, Jinsong

    2016-01-01

    A novel and facile strategy was proposed to construct a thermosetting/thermoplastic system with both shape memory and self-healing properties based on commercial epoxy resin and poly(ɛ-caprolactone)-PCL. Thermoplastic material is capable of re-structuring and changing the stiffness/modulus when the temperature is above melting temperature. PCL microfiber was used as a plasticizer in epoxy resin-based blends, and served as a ‘hard segment’ to fix a temporary shape of the composites during shape memory cycles. In this study, the electrospun PCL membrane with a porous network structure enabled a homogenous PCL fibrous distribution and optimized interaction between fiber and epoxy resin. The self-healing capability is achieved by phase transition during curing of the composites. The mechanism of the shape memory effect of the thermosetting (rubber)/thermoplastic composite is attributed to the structural design of the thermoplastic network inside the thermosetting resin/rubber matrix.

  14. S-system-based analysis of the robust properties common to many biochemical network models.

    PubMed

    Matsuoka, Yu; Jahan, Nusrat; Kurata, Hiroyuki

    2016-05-01

    Robustness is a key feature to characterize the adaptation of organisms to changes in their internal and external environments. A broad range of kinetic or dynamic models of biochemical systems have been developed. Robustness analyses are attractive for exploring some common properties of many biochemical models. To reveal such features, we transform different types of mathematical equations into a standard or intelligible formula and use the multiple parameter sensitivity (MPS) to identify some factors critically responsible for the total robustness to many perturbations. The MPS would be determined by the top quarter of the highly sensitive parameters rather than the single parameter with the maximum sensitivity. The MPS did not show any correlation to the network size. The MPS is closely related to the standard deviation of the sensitivity profile. A decrease in the standard deviation enhanced the total robustness, which shows the hallmark of distributed robustness that many factors (pathways) involve the total robustness. PMID:26861555

  15. Electromagnetic properties of a double-layer graphene system with electron-hole pairing

    NASA Astrophysics Data System (ADS)

    Germash, K. V.; Fil, D. V.

    2016-05-01

    We study electromagnetic properties of a double-layer graphene system in which electrons from one layer are coupled with holes from the other layer. The gauge invariant linear response functions are obtained. The frequency dependences of the transmission, reflection, and absorption coefficients are computed. We predict a peak in the reflection and absorption at the frequency equal to the gap in the quasiparticle spectrum. It is shown that the electron-hole pairing results in an essential modification of the spectrum of surface TM plasmons. We find that the optical TM mode splits into a low frequency undamped branch and a high frequency damped branch. At zero temperature the lower branch disappears. It is established that the pairing does not influence the acoustic TM mode. It is also shown that the pairing opens the frequency window in the subgap range for the surface TE wave.

  16. Low temperature transport properties of the quadrupolar Kondo lattice system PrTi2Al20

    NASA Astrophysics Data System (ADS)

    Sakai, Akito; Nakatsuji, Satoru

    2013-08-01

    We have investigated the low temperature transport properties of the cubic Γ3 compound PrTi2Al20. This is a quadrupolar Kondo lattice system where the nongmagnetic quadrupoles, which form a long-range order at low temperatures, have strong hybridization with the conduction electrons. A sharp drop of the resistivity due to a ferroquadrupole ordering is observed at T Q = 2.0 K. The T 2 dependence of the resistivity and the large Sommerfeld coefficient γ above T Q suggest the formation of a heavy-fermion state. The temperature dependence of the resistivity below T Q does not show a power law but exponential law behavior, indicating the emergence of an anisotropy gap Δ in the collective mode associated with the ferroquadrupole order below T Q. The Fisher-Langer relation holds around T Q, suggesting the higher order scattering processes than those in Born approximation are not dominant for this ferroquadrupole ordering.

  17. Dielectric and electro-optical properties of polymer-stabilized liquid crystal system

    NASA Astrophysics Data System (ADS)

    Pande, Mukti; Tripathi, Pankaj Kumar; Misra, Abhishek Kumar; Manohar, Shashwati; Manohar, Rajiv; Singh, Shri

    2016-03-01

    In this work, we report the results of dielectric and electro-optical properties as a function of temperature for both pure liquid crystal matrix and polymer-stabilized liquid crystal (PSLC). The threshold and saturation voltages have been determined from transmission-voltage curves. We have studied the polymer domains formation in PSLC with variation of concentration of polymer in liquid crystal matrix. It is observed that the dielectric anisotropy of PSLC is significantly influenced by the polar order present in the polymer domains environment. A delicate interplay between the orientational order of liquid crystal and polymeric domains determines the molecular orientations of PSLC with respect to the director of the LC system.

  18. Low Band Gap Thiophene-Perylene Diimide Systems with Tunable Charge Transport Properties

    SciTech Connect

    Balaji, Ganapathy; Kale, Tejaswini S.; Keerthi, Ashok; Della Pelle, Andrea M.; Thayumanavan, S.; Vallyaveettil, Surech

    2010-11-30

    Perylenediimide-pentathiophene systems with varied architecture of thiophene units were synthesized. The photophysical, electrochemical, and charge transport behavior of the synthesized compounds were studied. Both molecules showed a low band gap of ~1.4 eV. Surprisingly, the molecule with pentathiophene attached via β-position to the PDI unit upon annealing showed a predominant hole mobility of 1 × 10-4 cm2 V-1 s-1 whereas the compound with branched pentathiophene attached via β-position showed an electron mobility of 9.8 × 10-7 cm2 V-1 s-1. This suggests that charge transport properties can be tuned by simply varying the architecture of pentathiophene units.

  19. Properties of excited A = 40 nuclear systems with varying matter composition

    NASA Astrophysics Data System (ADS)

    Schmidt, K.; Natowitz, J. B.; Barbui, M.; Hagel, K.; Bonasera, A.; Giuliani, G.; Zheng, H.; Rodrigues, M.; Wada, R.; Huang, M.; Botosso, C.; Kowalski, S.

    2016-05-01

    There exists an intriguing problem when bosonic clusters as bound states of fermions are produced in the reaction, and the Bose character of the composite clusters competes with the fermionic properties of their constituents. In the analysis of 40Ca + 40Ca reactions at 35MeV/A we selected classes of projectile-like sources with exit channels consisting of only bosons, only fermions, only even-even nuclei, only odd - odd nuclei, only even - odd nuclei and only alpha-conjugate nuclei, respectively and searched for kinematic characteristics of these systems which might differ depending upon the type of matter selected. The distributions of various observables for the different classes of matter and comparisons between them will be presented and discussed.

  20. Effect of Milling Parameters on the Dehydrogenation Properties of the Mg-Ti-H system

    SciTech Connect

    Choi, Young Joon; Lu, Jun; Sohn, Hong Yong; Fang, Zhigang Zak; Ronnebro, Ewa

    2009-11-05

    Magnesium-based alloys are promising candidates as potential hydrogen storage materials due to their inherent high hydrogen contents. Small particle size which can be achieved by milling, and small amounts of transition-metal compounds as catalysts result in increased hydrogen release/uptake kinetics. In this work, we examined the effects of various milling parameters and TiH2 content on the dehydrogenation properties of the Mg-Ti-H system. The samples were prepared with different amounts of TiH2 using various milling methods and conditions. The activation energy and the enthalpy change of dehydrogenation of the milled samples were determined by Thermogravimetric Analysis (TGA) and Differential Thermal Analyzer (DTA). The results indicated that the activation energy and enthalpy change of MgH2 dehydrogenation were significantly reduced when 9.1 mol % of TiH2 was added to it and the mixture was milled in a dual planet

  1. Spectral properties of the extreme solar system objects 2012 DR30 and 2013 AZ60

    NASA Astrophysics Data System (ADS)

    Szabo, G.; Kiss, Cs.; Duffard, R.; Pinilla-Alonso, N.; Licandro, J.

    2014-04-01

    2012 DR30 and 2013 AZ60 represent two examples of TNOs with very large aphelion distances (2405 and 1951 AU, respectively), thus standing for the currently best candidates of possible scattered-in Oort-cloud objects. Though they possibly shared a similar dynamical scenario, the two bodies exhibit surprisingly diverging prediction for orbital evolution and also quite different surface properties (Kiss et al. 2013, Kiss et al. 2014). Here we compare these optical and infrared photometry and spectra of the two bodies. Both show a generaly flat spectrum, but with significantly differing slope. We find clear signs of water ice on 2013 DR30 particulary, which is an exciting diagnostic of a possible water reservoir at very large perihelion distances, and on the other hand, suggests a close link between the giant cometary nuclei of the Oort Cloud (for that Hale-Bopp is the only known example in our Solar System) and these exotic TNOs.

  2. Optimization of the thermodynamic properties and phase diagrams of P2O5-containing systems

    NASA Astrophysics Data System (ADS)

    Hudon, Pierre; Jung, In-Ho

    2014-05-01

    P2O5 is an important oxide component in the late stage products of numerous igneous rocks such as granites and pegmatites. Typically, P2O5 combines with CaO and crystallizes in the form of apatite, while in volatile-free conditions, Ca-whitlockite is formed. In spite of their interest, the thermodynamic properties and phase diagrams of P2O5-containg systems are not well known yet. In the case of the pure P2O5 for example, no experimental thermodynamic data are available for the liquid and the O and O' solid phases. As a result, we re-evaluated all the thermodynamic and phase diagram data of the P2O5 unary system [1]. Optimization of the thermodynamic properties and phase diagrams of the binary P2O5 systems was then performed including the Li2O-, Na2O-, MgO-, CaO-, BaO-, MnO-, FeO-, Fe2O3-, ZnO-, Al2O3-, and SiO2-P2O5 [2] systems. All available thermodynamic and phase equilibrium data were simultaneously reproduced in order to obtain a set of model equations for the Gibbs energies of all phases as functions of temperature and composition. In particular, the Gibbs energy of the liquid solution was described using the Modified Quasichemical Model [3-5] implemented in the FactSage software [6]. Thermodynamic modeling of the Li2O-Na2O-K2O-MgO-CaO-FeO-Fe2O3-Al2O3-SiO2 system, which include many granite-forming minerals such as nepheline, leucite, pyroxene, melilite, feldspar and spinel is currently in progress. [1] Jung, I.-H., Hudon, P. (2012) Thermodynamic assessment of P2O5. J. Am. Ceram. Soc., 95 (11), 3665-3672. [2] Rahman, M., Hudon, P. and Jung, I.-H. (2013) A coupled experimental study and thermodynamic modeling of the SiO2-P2O5 system. Metall. Mater. Trans. B, 44 (4), 837-852. [3] Pelton, A.D. and Blander, M. (1984) Computer-assisted analysis of the thermodynamic properties and phase diagrams of slags. Proc. AIME Symp. Metall. Slags Fluxes, TMS-AIME, 281-294. [4] Pelton, A.D. and Blander, M. (1986) Thermodynamic analysis of ordered liquid solutions by a modified

  3. Physical properties and antibacterial activity of chitosan/acemannan mixed systems.

    PubMed

    Escobedo-Lozano, Amada Yerén; Domard, Alain; Velázquez, Carlos A; Goycoolea, Francisco M; Argüelles-Monal, Waldo M

    2015-01-22

    The aim of the present study was to investigate the mechanical and thermal properties of mixed chitosan-acemannan (CS-AC) mixed gels and the antibacterial activity of dilute mixed solutions of both polysaccharides. Physical hydrogels of chitosan comprising varying amounts of non-gelling acemannan were prepared by controlled neutralization of chitosan using ammonia. As the overall acemannan concentration in the mixed hydrogel increased while fixing that of CS, the mechanical strength decreased. These results indicate that AC perturbs the formation of elastic junctions and overall connectivity as it occurs in the isolated CS network. Heterotypic associations between CS and AC leading to the formation of more compact microdomains may be at play in reducing the density of the gel network consolidated by CS, possibly due to shorter gel junctions. Micro-DSC studies at pH 12.0 seem consistent with the suggestion that molecular heterotypic associations between CS and AC may be at play in determining the overall physical properties of the mixed gel systems. In dilute solution, CS showed antimicrobial activity against Staphylococcus aureus but not against Escherichia coli; AC did not exert antimicrobial activity against any of the two bacterial species. In blended solutions of both polysaccharides, as the amount of AC increased, the antimicrobial activity of the system against S. aureus ceased. In conclusion, this study demonstrates that it is feasible to incorporate acemannan in chitosan-acemannan gels and that although the mechanical strength decreases due to the presence of AC, the gel network persists even at high amount of AC. This study anticipates that the CS-AC mixed gels may offer promise for the future development of biomaterials such as scaffolds to be used in wound therapy. PMID:25439952

  4. Scales and properties of cold filaments in the Benguela upwelling system off Lüderitz

    NASA Astrophysics Data System (ADS)

    Hösen, Elisabeth; Möller, Judith; Jochumsen, Kerstin; Quadfasel, Detlef

    2016-03-01

    The Benguela upwelling system is one of the four strongest upwelling systems in the world. Meso-scale and submeso-scale structures like eddies and filaments build up at the front between the cold upwelled water and the warm surface water offshore. From three and a half years of satellite data (MODIS) of sea surface temperature (SST) more than 450 filaments were identified and used for extensive statistics of the scales, the occurrence frequency and the location of filaments in the Lüderitz upwelling cell and its vicinity. In situ data of SST, sea surface salinity and profiles of temperature, salinity and velocity collected during six cruises between September 2011 and February 2014 provide information on the properties of filaments and on their vertical structure. The occurrence of the filaments shows a maximum in austral summer and a minimum in September similar to the seasonal intensity of the upwelling. Within the Lüderitz cell, filaments have a meridional extent between 5 km and 80 km, an offshore extent between 20 km and more than 500 km and a vertical extent between 70 m and 180 m. The temperature within the filaments is 0.25 - 2.5°C lower than the ambient temperature and their salinity is up to 0.6 lower than the ambient salinity. Within the filaments westerly currents with velocities up to 30 cm/s were observed. Mean filament properties and occurrence result in an offshore volume transport of 3 Sv and a heat transport anomaly of -3 × 1013W.

  5. Ionizable Nitroxides for Studying Local Electrostatic Properties of Lipid Bilayers and Protein Systems by EPR

    PubMed Central

    Voinov, Maxim A.; Smirnov, Alex I.

    2016-01-01

    Electrostatic interactions are known to play one of the major roles in the myriad of biochemical and biophysical processes. In this Chapter we describe biophysical methods to probe local electrostatic potentials of proteins and lipid bilayer systems that is based on an observation of reversible protonation of nitroxides by EPR. Two types of the electrostatic probes are discussed. The first one includes methanethiosulfonate derivatives of protonatable nitroxides that could be used for highly specific covalent modification of the cysteine’s sulfhydryl groups. Such spin labels are very similar in magnetic parameters and chemical properties to conventional MTSL making them suitable for studying local electrostatic properties of protein-lipid interfaces. The second type of EPR probes is designed as spin-labeled phospholipids having a protonatable nitroxide tethered to the polar head group. The probes of both types report on their ionization state through changes in magnetic parameters and a degree of rotational averaging, thus, allowing one to determine the electrostatic contribution to the interfacial pKa of the nitroxide, and, therefore, determining the local electrostatic potential. Due to their small molecular volume these probes cause a minimal perturbation to the protein or lipid system while covalent attachment secure the position of the reporter nitroxides. Experimental procedures to characterize and calibrate these probes by EPR and also the methods to analyze the EPR spectra by least-squares simulations are also outlined. The ionizable nitroxide labels and the nitroxide-labeled phospholipids described so far cover an exceptionally wide pH range from ca. 2.5 to 7.0 pH units making them suitable to study a broad range of biophysical phenomena especially at the negatively charged lipid bilayer surfaces. The rationale for selecting proper electrostatically neutral interface for calibrating such probes and example of studying surface potential of lipid bilayer is

  6. Ice Cloud Properties in Ice-Over-Water Cloud Systems Using TRMM VIRS and TMI Data

    NASA Technical Reports Server (NTRS)

    Minnis, Patrick; Huang, Jianping; Lin, Bing; Yi, Yuhong; Arduini, Robert F.; Fan, Tai-Fang; Ayers, J. Kirk; Mace, Gerald G.

    2007-01-01

    A multi-layered cloud retrieval system (MCRS) is updated and used to estimate ice water path in maritime ice-over-water clouds using Visible and Infrared Scanner (VIRS) and TRMM Microwave Imager (TMI) measurements from the Tropical Rainfall Measuring Mission spacecraft between January and August 1998. Lookup tables of top-of-atmosphere 0.65- m reflectance are developed for ice-over-water cloud systems using radiative transfer calculations with various combinations of ice-over-water cloud layers. The liquid and ice water paths, LWP and IWP, respectively, are determined with the MCRS using these lookup tables with a combination of microwave (MW), visible (VIS), and infrared (IR) data. LWP, determined directly from the TMI MW data, is used to define the lower-level cloud properties to select the proper lookup table. The properties of the upper-level ice clouds, such as optical depth and effective size, are then derived using the Visible Infrared Solar-infrared Split-window Technique (VISST), which matches the VIRS IR, 3.9- m, and VIS data to the multilayer-cloud lookup table reflectances and a set of emittance parameterizations. Initial comparisons with surface-based radar retrievals suggest that this enhanced MCRS can significantly improve the accuracy and decrease the IWP in overlapped clouds by 42% and 13% compared to using the single-layer VISST and an earlier simplified MW-VIS-IR (MVI) differencing method, respectively, for ice-over-water cloud systems. The tropical distribution of ice-over-water clouds is the same as derived earlier from combined TMI and VIRS data, but the new values of IWP and optical depth are slightly larger than the older MVI values, and exceed those of single-layered layered clouds by 7% and 11%, respectively. The mean IWP from the MCRS is 8-14% greater than that retrieved from radar retrievals of overlapped clouds over two surface sites and the standard deviations of the differences are similar to those for single-layered clouds. Examples

  7. Properties and Frequency Conversion of High-Brightness Diode-Laser Systems

    NASA Astrophysics Data System (ADS)

    Boller, Klaus-Jochen; Beier, Bernard; Wallenstein, Richard

    An overview of recent developments in the field of high-power, high-brightness diode-lasers, and the optically nonlinear conversion of their output into other wavelength ranges, is given. We describe the generation of continuous-wave (CW) laser beams at power levels of several hundreds of milliwatts to several watts with near-perfect spatial and spectral properties using Master-Oscillator Power-Amplifier (MOPA) systems. With single- or double-stage systems, using amplifiers of tapered or rectangular geometry, up to 2.85 W high-brightness radiation is generated at wavelengths around 810nm with AlGaAs diodes. Even higher powers, up to 5.2W of single-frequency and high spatial quality beams at 925nm, are obtained with InGaAs diodes. We describe the basic properties of the oscillators and amplifiers used. A strict proof-of-quality for the diode radiation is provided by direct and efficient nonlinear optical conversion of the diode MOPA output into other wavelength ranges. We review recent experiments with the highest power levels obtained so far by direct frequency doubling of diode radiation. In these experiments, 100mW single-frequency ultraviolet light at 403nm was generated, as well as 1W of single-frequency blue radiation at 465nm. Nonlinear conversion of diode radiation into widely tunable infrared radiation has recently yielded record values. We review the efficient generation of widely tunable single-frequency radiation in the infrared with diode-pumped Optical Parametric Oscillators (OPOs). With this system, single-frequency output radiation with powers of more than 0.5W was generated, widely tunable around wavelengths of 2.1,m and 1.65,m and with excellent spectral and spatial quality. These developments are clear indicators of recent advances in the field of high-brightness diode-MOPA systems, and may emphasize their future central importance for applications within a vast range of optical

  8. New epoxy/episulfide resin system for electronic and coating applications: Curing mechanisms and properties

    NASA Astrophysics Data System (ADS)

    Tsuchida, Katsuyuki

    This work involves research on a new resin system useful for printed circuit board and protective coating applications. The system provides excellent adhesion to copper and corrosion resistance for copper. The research involved detailed studies of the reaction mechanisms, and correlation of these mechanisms with the observed properties. The epoxy/episulfide system, when used with a dicyandiamide (DICY) curing agent, exhibits better adhesion to copper substrate, a better pot life and prepreg storage life, a lower thermal expansion coefficient, a lower heat of reaction, a lower degradation temperature, and higher water absorption as compared with the standard epoxy system. From model compound studies, the sulfur of the opened episulfide ring reacts with copper, resulting in a durable bond between the copper and matrix resin even after water boiling. Since the S- formed by the reaction of the episulfide with the curing agent easily reacts with both the episulfide and the epoxy, a C-S-C bond is formed and more unreacted curing agent remains as compared to the standard epoxy system. The new bond formation causes a lower thermal expansion coefficient and somewhat lower degradation temperature. The unreacted curing agent causes slightly higher water absorption. Since the episulfide ring has less stress than the epoxy ring the epoxy/episulfide system shows lower heat of reaction, i.e., a lower exotherm. and lower shrinkage. The epoxy/episuffide system, when used with a polyamide curing agent, exhibits better corrosion protection for copper substrates, a lower thermal expansion coefficient and a lower degradation temperature. From model compound studies, the curing reactions are changed by changing curing temperature and the presence of copper: the episulfide homopolymerization and the S--epoxy reactions increase in the case of room temperature curing or in the presence of copper. In the presence of copper, the sulfur of the episulfide also reacts with copper, although the

  9. Computer program for investigating effects of nonlinear suspension-system elastic properties on parachute inflation loads and motions

    NASA Technical Reports Server (NTRS)

    Poole, L. R.

    1972-01-01

    A computer program is presented by which the effects of nonlinear suspension-system elastic characteristics on parachute inflation loads and motions can be investigated. A mathematical elastic model of suspension-system geometry is coupled to the planar equations of motion of a general vehicle and canopy. Canopy geometry and aerodynamic drag characteristics and suspension-system elastic properties are tabular inputs. The equations of motion are numerically integrated by use of an equivalent fifth-order Runge-Kutta technique.

  10. Spectral properties of water ice and contaminants. [of importance to remote sensing of ice in solar system

    NASA Technical Reports Server (NTRS)

    Lucey, P. G.; Clark, R. N.

    1985-01-01

    For remote sensing studies of ices in the solar system, it is important to understand the optical properties of water ice, and mixtures of ice and particulate materials. The present paper has the objective to review the current understanding of the spectral properties of ice, and mixtures of ice and particulates. The review is to provide a basis for the understanding of the remote sensing of ice. It is found that reflectance spectra of ice-soil intimate mixtures are complex, nonlinear functions of the optical and physical properties of the components which comprise the surface.

  11. Unexpected high pressure effects on the structural properties of condensed whey protein systems.

    PubMed

    Dissanayake, Muditha; Kasapis, Stefan; Chaudhary, Vinita; Adhikari, Benu; Palmer, Martin; Meurer, Barbara

    2012-12-01

    We show that application of high hydrostatic pressure (600 MPa for 15 min) on condensed whey protein (WP) systems (e.g., 80% w/w solids content) results in unexpected structure-function behavior when compared with conventional thermal treatment. Unraveling the relaxation properties in first-order thermodynamic transitions, the manifestation of glass transition phenomena and the preservation of native conformation in condensed preparations were recorded using small-deformation dynamic oscillation in shear, modulated differential scanning calorimetry, and infrared spectroscopy. Informed temperature application results in the formation of continuous networks at the denaturation temperature, which undergo vitrification at subzero temperatures. In contrast, high-pressure-treated WPs resist physicochemical denaturation, hence preserving the native conformation of secondary and tertiary structures. This was rationalized on the basis of a critical concentration threshold where transfer of water molecules to nonpolar residues in the protein interior is minimized because of low moisture content and restricted molecular mobility. The physical state and morphology of these high-solid preparations were further examined by the combined framework of reduced variables and Williams, Landel, and Ferry equation/free volume theory. Theoretical treatment of experimental observations unveils the dynamic range of the mechanical manifestation of the glass transition region in samples subjected to heat or pressure. In addition to preserving native conformation, WPs subjected to high pressure form glassy systems at parity with the structural functionality of the thermally treated counterparts. PMID:22987587

  12. Thermodynamic and structural properties of model systems at solid-fluid coexistence

    NASA Astrophysics Data System (ADS)

    Agrawal, Rupal; Kofke, David A.

    Properties of coexisting fluid and solid phases of the Lennard-Jones model potential are reported. The melting line, representing equilibrium between the solid and liquid phases, is computed by performing a thermodynamic integration along a path that follows the coexistence line itself, according to the Gibbs-Duhem integration method recently introduced by us. Monte Carlo simulations are conducted to compute the quantities needed by the method; two system sizes, with particles numbering approximately 100 and 500, respectively, are examined. The starting point for the integration is the soft sphere system obtained in the limit of high temperature. The procedure terminates at the solid-liquid-vapour triple point, and thus the entire melting line is determined. Our results for the melting pressure are about 10% higher than those reported previously in the literature, while the triple point temperature we compute is in accord with the established value. An analysis of the approach to the high-temperature limit is used to construct a functional form for the melting line; this is fitted to the data, reproducing all of them to within their estimated errors. Another integration is initiated from the triple point to compute part of the sublimation line. Several semi-empirical 'melting rules' are examined in the light of the new results.

  13. Mean state and kinematic properties of mesoscale convective systems over West Africa

    NASA Astrophysics Data System (ADS)

    Ogungbenro, Stephen B.; Ajayi, V. O.; Adefolalu, D. O.

    2016-04-01

    A 17-year (1984 to 2000) dataset of brightness temperature (T b) was employed to study the spatial and temporal scales of mesoscale convective systems (MCS) over West Africa. The kinematic properties of MCS were tested using wind products. A threshold brightness temperature (T b) of ≤213 K and spatial coverage specifications of more than 5000 km2 were used as two set criteria for initiating MCS tracking. MCS occurrences vary in seasons and locations over West Africa, and their activities vary with different weather zones. They can appear at any time of the day, but this study revealed a significant preference for early morning hours and night hours over continental West Africa. The well-organized systems occur between July and September in the Sahel, and between May and September in the Savanna band. MCS activities in the Gulf of Guinea peak between March and April, while the Savanna and Sahel zones peak between June and August. The produced annual atlas gives a spatial account of areas of MCS dominance in West Africa. The presence of African Easterly Jet (AEJ) and Tropical Easterly Jet (TEJ), and deep monsoon depth all characterize an environment where MCS thrive. Kinematic study of a typical MCS reveals that the monsoon depth increases at the passage of MCS, with cyclonic vorticity dominating from the surface to 300 hpa while anticyclonic vorticity was observed around 200 hpa, and this confirms the importance of low level convergence and upper level divergence as the major requirements for storm mobilization and maintenance.

  14. Three-dimensional imaging properties of rotation-free square and hexagonal micro-CT systems

    NASA Astrophysics Data System (ADS)

    Quan, Enzhuo; Lalush, David S.

    2009-02-01

    We perform simulation studies of proposed square and hexagonal geometries of a multi-source X-ray micro-computed tomography (CT) system. The system uses linear arrays of the carbon nano-tube (CNT)-based X-ray sources which are individually addressable. In the square geometry, two linear source arrays and two area detectors form a square; whereas in the hexagonal geometry, three linear source arrays and three area detectors form a hexagon. The tomographic angular sampling for both geometries requires no motion of the sources or subject. Based on the sinogram maps, the hexagonal geometry has improved angular coverage than the square geometry. The ordered-subset convex iterative algorithm is implemented in both geometries for reconstructions from cone-beam projection data. The reconstructed images from both geometries are generally consistent with the phantom, although some streaking artifacts due to the limited-angle nature of the geometries are observed. The two geometries show similar performance in resolution-noise tradeoff. The gap-free hexagonal geometry produces lower mean squared error in the reconstructed images; when gaps between the source arrays and detectors are introduced, the angular coverage of the hexagonal geometry degrades faster and becomes worse than the square geometry. The impact of gaps on the imaging properties must be studied further.

  15. Influence of reverse bias on the LEDs properties used as photo-detectors in VLC systems

    NASA Astrophysics Data System (ADS)

    Kowalczyk, Marcin; Siuzdak, Jerzy

    2015-09-01

    Continuous increasing share of light emitting diodes (LEDs) in a lighting market, which we observe during the last couple years, opens new possibilities. Especially, when we talk about practical realization the concept of visible light communications (VLC), which gains on popularity recently. The VLC concept presupposes utilization of illumination systems for a purpose of data transmission. It means, the emitters, in this case the LEDs, will not of a light source only, but also the data transmitters. Currently, most of the conducted researches in this area is concentrated on achievement of effective transmission methods. It means a transmission only in one direction. This is not enough, when we talk about the fully functional transmission system. Ensuring of feedback transmission channel is a necessary also. One of the ideas, which was postulated by authors of this article, is using for this purpose the LEDs in a double role. A utilization of LEDs as photo-detectors requires a reverse polarization, in contrast to a forward bias, which has a place when they work as light emitters. Ensuring of proper polarization get significant meaning. The article presents the investigations results on the influence of reverse bias on photo-receiving properties of LEDs used as light detectors. The conducted research proved that an improvement of sensitivity and bandwidth parameters are possible by application of appropriate value of the reverse voltage in a receiver.

  16. Physical properties and transmission spectrum of the WASP-80 planetary system from multi-colour photometry

    NASA Astrophysics Data System (ADS)

    Mancini, L.; Southworth, J.; Ciceri, S.; Dominik, M.; Henning, Th.; Jørgensen, U. G.; Lanza, A. F.; Rabus, M.; Snodgrass, C.; Vilela, C.; Alsubai, K. A.; Bozza, V.; Bramich, D. M.; Calchi Novati, S.; D'Ago, G.; Figuera Jaimes, R.; Galianni, P.; Gu, S.-H.; Harpsøe, K.; Hinse, T.; Hundertmark, M.; Juncher, D.; Kains, N.; Korhonen, H.; Popovas, A.; Rahvar, S.; Skottfelt, J.; Street, R.; Surdej, J.; Tsapras, Y.; Wang, X.-B.; Wertz, O.

    2014-02-01

    WASP-80 is one of only two systems known to contain a hot Jupiter which transits its M-dwarf host star. We present eight light curves of one transit event, obtained simultaneously using two defocussed telescopes. These data were taken through the Bessell I, Sloan g'r'i'z' and near-infrared JHK passbands. We use our data to search for opacity-induced changes in the planetary radius, but find that all values agree with each other. Our data are therefore consistent with a flat transmission spectrum to within the observational uncertainties. We also measure an activity index of the host star of log R 'HK = -4.495, meaning that WASP-80 A shows strong chromospheric activity. The non-detection of starspots implies that, if they exist, they must be small and symmetrically distributed on the stellar surface. We model all available optical transit light curves and obtain improved physical properties and orbital ephemerides for the system. Full Table 2 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/562/A126

  17. Using robotic systems in order to determine biomechanical properties of soft tissues.

    PubMed

    Kunkel, M E; Moral, A; Westphal, R; Rode, D; Rilk, M; Wahl, F M

    2008-01-01

    Biomechanical properties of soft tissue are important not only during computer simulation for medical training but also for systems where tissue deformation must be estimated in real-time, for example, Robot Assisted Surgery. The purpose of this paper is to describe some biomechanical tests consisting in the measurement of contact forces and deformations in tissue phantoms and porcine soft tissues (liver, brain, stomach and intestine). During the measurements two different procedures were applied. First, we have used a 5DOF micromanipulator instrumented with a spherical probe and a 6-axis force/torque ATI sensor. In the second procedure instead of the micromanipulator a Stäubli RX60 robot was used to apply the force over the samples. During this last test a high noise-signal relationship was detected and in order to improve the accuracy of the experiments some results were obtained using a Stäubli TX40 robot. Major accuracy in research in the field of soft tissue could be reached using standard procedures. Robotic systems allow precise movements to carry on biomechanical tests, and also permit a wide range of tasks to be implemented. PMID:18376024

  18. Variations of Cloud and Radiative Properties of Boundary-layer and Deep Convective Systems with Sea Surface Temperature Anomalies

    NASA Technical Reports Server (NTRS)

    Xu, Kuan-Man

    2010-01-01

    Gridded monthly-mean satellite data contain compositing information from different cloud system types and clear-sky environments. To isolate the variations of cloud physical properties of an individual cloud system type with its environment, orbital data are needed. In this study, we will analyze the variations of cloud and radiative properties of boundary-layer clouds and deep convective cloud systems with sea surface temperature (SST) anomalies. We use Terra-CERES (Clouds and the Earth s Radiant Energy System) Level 2 data to classify distinct cloud objects defined by cloud-system types (deep convection, boundary-layer cumulus, stratocumulus and overcast clouds), sizes, geographic locations, and matched large-scale environments. This analysis method identifies a cloud object as a contiguous region of the Earth with a single dominant cloud-system type. It determines the shape and size of the cloud object from the satellite data and the cloud-system selection criteria. The statistical properties of the identified cloud objects are analyzed in terms of probability density functions (PDFs) of a single property or joint PDFs between two properties. The SST anomalies are defined as the differences from five-year annual-cycle means. Individual cloud objects are sorted into one of five equal size subsets, with the matched SST anomalies ranging from the most negative to the most positive values, for a given size category of deep convective cloud objects, boundary-layer cumulus, stratocumulus and overcast cloud objects. The PDFs of cloud and radiative properties for deep convective cloud objects (between 30 S and 30 N) are found to largely similar among the five SST anomaly subsets except for the lowest SST anomaly subset. The different characteristics from this SST anomaly subset may be related to some cloud objects resulting from equatorward movement of extratropical cloud systems. This result holds true for all three different size categories (measured by equivalent

  19. Effects of chemical alteration on fracture mechanical properties in hydrothermal systems

    NASA Astrophysics Data System (ADS)

    Callahan, O. A.; Eichhubl, P.; Olson, J. E.

    2015-12-01

    Fault and fracture networks often control the distribution of fluids and heat in hydrothermal and epithermal systems, and in related geothermal and mineral resources. Additional chemical influences on conduit evolution are well documented, with dissolution and precipitation of mineral species potentially changing the permeability of fault-facture networks. Less well understood are the impacts of chemical alteration on the mechanical properties governing fracture growth and fracture network geometry. We use double-torsion (DT) load relaxation tests under ambient air conditions to measure the mode-I fracture toughness (KIC) and subcritical fracture growth index (SCI) of variably altered rock samples obtained from outcrop in Dixie Valley, NV. Samples from southern Dixie Valley include 1) weakly altered granite, characterized by minor sericite in plagioclase, albitization and vacuolization of feldspars, and incomplete replacement of biotite with chlorite, and 2) granite from an area of locally intense propylitic alteration with chlorite-calcite-hematite-epidote assemblages. We also evaluated samples of completely silicified gabbro obtained from the Dixie Comstock epithermal gold deposit. In the weakly altered granite KIC and SCI are 1.3 ±0.2 MPam1/2 (n=8) and 59 ±25 (n=29), respectively. In the propylitic assemblage KIC is reduced to 0.6 ±0.1 MPam1/2 (n=11), and the SCI increased to 75 ±36 (n = 33). In both cases, the altered materials have lower fracture toughness and higher SCI than is reported for common geomechanical standards such as Westerly Granite (KIC ~1.7 MPam1/2; SCI ~48). Preliminary analysis of the silicified gabbro shows a significant increase in fracture toughness, 3.6 ±0.4 MPam1/2 (n=2), and SCI, 102 ±45 (n=19), compared to published values for gabbro (2.9 MPam1/2 and SCI = 32). These results suggest that mineralogical and textural changes associated with different alteration assemblages may result in spatially variable rates of fracture

  20. Real-Time Observations of Optical Properties of Arctic Sea Ice with an Autonomous System

    NASA Astrophysics Data System (ADS)

    Wang, C.; Gerland, S.; Nicolaus, M.; Granskog, M. A.; Hudson, S. R.; Perovich, D. K.; Karlsen, T. I.; Fossan, K.

    2012-12-01

    The recent drastic changes in the Arctic sea ice cover have altered the interaction of solar radiation and sea ice. To improve our understanding of this interaction, a Spectral Radiation Buoy (SRB) for measuring sea ice optical properties was developed, based on a system used during the last International Polar Year at the drift of "Tara" across the Arctic Ocean. A first version of the SRB was deployed on drifting ice in the high Arctic in April 2012. It includes three Satlantic spectral radiometers (two in air, one under ice), covering the wavelength range from 347 nm to 804 nm with 3.3 nm spectral resolution, a bio-shutter to protect the under-ice radiometer, a data logger to handle and store collected data, and an Iridium satellite modem to transfer data in real-time. The under-ice radiometer is mounted on an adjustable under-ice arm, and the other instruments are mounted on a triangular frame frozen into the ice. The SRB measures simultaneously, autonomously and continuously the spectral fluxes of incident and reflected solar radiation, as well as under-ice irradiance, water temperature and water pressure every hour. So far, between mid April and early August 2012, the system has drifted about 600 km, from the starting position near the North Pole towards the Fram Strait. The data collected during this deployment, so far, already demonstrate that this system is suitable for autonomous and long-term observations over and under sea ice in harsh conditions. Along with the SRB, commercially available Ice Mass Balance buoys (IMB) were deployed on the same ice floe. In the vicinity of the site, manned baseline measurements of snow and sea ice physical properties have been carried out during the SRB deployment. The combined datasets allow description of the evolution of the ice floe during seasonal melt. With snow melt, the spectral surface albedo decreased and the transmittance through the snow and ice increased after mid-April, especially when melt ponds started to

  1. Surface active properties of polyoxyethylene macromonomers and their role in radical polymerization in disperse systems.

    PubMed

    Capek, I

    2000-12-26

    Conventional dispersion polymerization and copolymerization of low-molecular weight (conventional) unsaturated monomers allows preparation of monodisperse and micronsize polymer particles. A similar behavior can be found in the surfactant-free dispersion polymerization of non-traditional vinyl monomers, unsaturated macromonomers. The latter systems allow preparation of random, comb-like, star-like and graft copolymers as well. An interesting alternative arises with the use of amphiphilic reactive macromonomers that contain a polymerizable group and aggregate into an organized structure -- a micelle. Under such conditions the high rate of polymerization and ultrafine (microparticles) polymer dispersions are generated. Thus, the surface-active macromonomers promote the formation of micelles and polymer growth within the main reaction loci -- polymer particles. Furthermore, the surface-active compounds can be formed during the copolymerization of hydrophilic macromonomer and hydrophobic low-molecular weight comonomer. The reactive surface-active oligomeric radicals are incorporated into the polymer matrix or the particle surface layer, which prevents them from subsequent migration. Besides, the covalently bound surface-active groups at the particle surface strongly increase the colloidal stability of final polymer dispersion. This article presents a review of the current literature in the field of the surfactant-free dispersion polymerization of the polyoxyethylene unsaturated macromonomers. Besides a short introduction into some kinetic aspects of radical polymerization of traditional monomers in homogeneous and disperse systems, we mainly focus on the organized aggregation of amphiphilic polyoxyethylene macromonomers, the characterization of amphiphilic graft copolymers and their aggregation properties, and radical copolymerization of polyoxyethylene macromonomers. We discuss the birth and growth of chains, the transfer of reaction loci from the continuous phase to

  2. EMTA’s Evaluation of the Elastic Properties for Fiber Polymer Composites Potentially Used in Hydropower Systems

    SciTech Connect

    Nguyen, Ba Nghiep; Paquette, Joshua

    2010-08-01

    Fiber-reinforced polymer composites can offer important advantages over metals where lightweight, cost-effective manufacturing and high mechanical performance can be achieved. To date, these materials have not been used in hydropower systems. In view of the possibility to tailor their mechanical properties to specific applications, they now have become a subject of research for potential use in hydropower systems. The first step in any structural design that uses composite materials consists of evaluating the basic composite mechanical properties as a function of the as-formed composite microstructure. These basic properties are the elastic stiffness, stress-strain response, and strength. This report describes the evaluation of the elastic stiffness for a series of common discontinuous fiber polymer composites processed by injection molding and compression molding in order to preliminarily estimate whether these composites could be used in hydropower systems for load-carrying components such as turbine blades. To this end, the EMTA (Copyright © Battelle 2010) predictive modeling tool developed at the Pacific Northwest National Laboratory (PNNL) has been applied to predict the elastic properties of these composites as a function of three key microstructural parameters: fiber volume fraction, fiber orientation distribution, and fiber length distribution. These parameters strongly control the composite mechanical performance and can be tailored to achieve property enhancement. EMTA uses the standard and enhanced Mori-Tanaka type models combined with the Eshelby equivalent inclusion method to predict the thermoelastic properties of the composite based on its microstructure.

  3. Computer program for calculation of thermodynamic and transport properties of complex chemical systems

    NASA Technical Reports Server (NTRS)

    Svehla, R. A.; Mcbride, B. J.

    1973-01-01

    Program performs calculations such as chemical equilibrium for assigned thermodynamic states, theoretical rocket performance for both equilibrium and frozen compositions during expansion, incident and reflected shock properties, and Chapman-Jouget detonation properties. Features include simplicity of input and storage of all thermodynamic and transport property data on master tape.

  4. EVALUATION OF SORPTIVE PROPERTIES OF VARIOUS CARRIERS AND COATING MATERIALS FOR LIQUISOLID SYSTEMS.

    PubMed

    Vraníková, Barbora; Gajdziok, Jan

    2015-01-01

    The basic principle of liquisolid systems formulation lies in the conversion of the drug in a liquid state into an apparently dry, free-flowing and readily compressible powder by its blending (or spraying) with specific carriers and coating materials. The selection of the most suitable carrier and coating material depends especially on their values of flowable liquid retention potential (Φ), which is defined as the maximum mass of liquid that can be retained per unit mass of powder material, while maintaining an acceptable flowability. The presented work focused on the determination of the maximum amount of propylene glycol (PG), which can be retained by several selected carriers and coating materials while maintaining acceptable flow properties of the liquisolid powder blend. Granulated forms of magnesium aluminometasilicates (Neusilin® US2 and Neusilin® NS2N), dibasic calcium phosphate (Fujicalin®) and microcrystalline cellulose (Avicel® PH 101) were tested due to their frequent use. Powdered forms of magnesium aluminometasilicate (Neusilin® UFL2) and colloidal silica (Aerosil® 200) were used as common coating materials. From the evaluation of liquisolid mixtures with different amounts of liquid, it could be observed that 1 g of Neusilin® US2, Neusilin® UFL2, Neusilin® NS2N, Aerosil® 200, Fujicalin® and Avicel® PH 101 can retain 1.00, 0.97, 0.54, 0.04, 0.25 and 0.12 g of propylene glycol, respectively, while maintaining acceptable flowing properties for further processing. PMID:26642662

  5. Generation of Individual Diversity: A Too Neglected Fundamental Property of Adaptive Immune System

    PubMed Central

    Muraille, Eric

    2014-01-01

    The fitness gains resulting from development of the adaptive immune system (AIS) during evolution are still the subject of hot debate. A large random repertoire of antigenic receptors is costly to develop and could be the source of autoimmune reactions. And yet, despite their drawbacks, AIS-like systems seem to have been independently acquired in several phyla of metazoans with very different anatomies, longevities, and lifestyles. This article is a speculative attempt to explore the selective pressures, which favored this striking convergent evolution. It is well known that the AIS enables an organism to produce a specific immune response against all natural or artificial antigenic structures. However, it is frequently neglected that this response is highly variable among individuals. In practice, each individual possesses a “private” adaptive immune repertoire. This individualization of immune defenses implies that invasion and escape immune mechanisms developed by pathogens will certainly not always be successful as the specific targets and organization of the immune response are somewhat unpredictable. In a population, where individuals display heterogeneous immune responses to infection, the probability that a pathogen is able to infect all individuals could be reduced compared to a homogeneous population. This suggests that the individual diversity of the immune repertoire is not a by-product of the AIS but of its fundamental properties and could be in part responsible for repeated selection and conservation of the AIS during metazoan evolution. The capacity of the AIS to improve the management of cooperative or parasitic symbiotic relationships at the individual level could be a secondary development due to its progressive integration into the innate immune system. This hypothesis constitutes a new scenario for AIS emergence and explains the selection of MHC restriction and MHC diversification. PMID:24860570

  6. Idiopathic scoliosis. Mechanical properties of the respiratory system and the ventilatory response to carbon dioxide.

    PubMed

    Kafer, E R

    1975-06-01

    The aims were to examine the effects of scoliosis (angle), and age on lung volumes, elastic properties of the respiratory system, and the ventilatory response to CO2. The mean age of the 55 patients was 25.4 plus or minus SEM 2.5 yr, and the mean angle was 80 plus or minus SEM 4.2. The mean plus or minus SEM percent predicted lung volumes were vital capacity (VC), 60.5 plus or minus 2.7; total lung capacity (TLC), 70,2 plus or minus 2.6; functional residual capacity (frc), 79.3 plus or minus 3.2; and residual volume (RV), 99.7 plus or minus 5.2. The correlation coefficients between the angle of scoliosis and each of the following were significant: TLC (-0.548), percent predicted TLC (-0.547), VC (-0.485), percent predicted VC (-0.523), FRC (-0.533), percent predicted FRC (-0.338), RV (-0.438), and percent predicted RV (-0.318). The mean compliance of the total respiratory system (Crs) was 0.049 litter/cm H2O plus or minus SEM 0.004, and the mean compliance of the chest wall (Ccw) was 0.080 liter/cm H2O plus or minus SEM 0.012. The Crs and Ccw were inversely proportional to the angle (r-0.620 and -0.721) and directly proportional to the height and the weight. The mean deltaV/deltaPco2 was 1.32 liter/min per mm Hg (SEM 0.171), and the mean deltaVt/deltaPco2 was 28.9 ml/mm Hg (SEM 3.64). The correlation coefficients between deltaV/deltaPco2 and the following were height, 0.499; VC, 0.792; TLC, 0.632; AND Crs, 0.520; and between the deltaTt/deltaPco2 and the following were height, 0.500; VC, 0.878; TLC, 0.802; and Crs, 0.590. We conclude that body size and the deformity were the determinants of the lung volumes and the mechanical properties of the respiratory system, and that these variables were the major factors in both the magnitude and pattern of the ventilatory response to CO2. The correlations between age and the mechanical properties of the respiratory sytem, deltaV/deltaPco2, and deltaVt/deltaPco2, were not significant, but the correlation coefficients between

  7. HD 152246: a new high-mass triple system and its basic properties

    NASA Astrophysics Data System (ADS)

    Nasseri, A.; Chini, R.; Harmanec, P.; Mayer, P.; Nemravová, J. A.; Dembsky, T.; Lehmann, H.; Sana, H.; Le Bouquin, J.-B.

    2014-08-01

    Analyses of multi-epoch, high-resolution (R ~ 50 000) optical spectra of the O-type star HD 152246 (O9 IV according to the most recent classification), complemented by a limited number of earlier published radial velocities, led to the finding that the object is a hierarchical triple system, where a close inner pair (Ba-Bb) with a slightly eccentric orbit (e = 0.11) and a period of 6.^d0049 revolves in a 470-day highly eccentric orbit (e = 0.865) with another massive and brighter component A. The mass ratio of the inner system must be low since we were unable to find any traces of the secondary spectrum. The mass ratio A/(Ba+Bb) is 0.89. The outer system has recently been resolved using long-baseline interferometry on three occasions. The interferometry confirms the spectroscopic results and specifies elements of the system. Our orbital solutions, including the combined radial-velocity and interferometric solution indicate an orbital inclination of the outer orbit of 112° and stellar masses of 20.4 and 22.8 M⊙. We also disentangled the spectra of components A and Ba and compare them to synthetic spectra from two independent programmes, TLUSTY and FASTWIND. In either case, the fit was not satisfactory and we postpone a better determination of the system properties for a future study, after obtaining observations during the periastron passage of the outer orbit (the nearest chance being March 2015). For the moment, we can only conclude that component A is an O9 IV star with v sin i = 210 ± 10 km s-1and effective temperature of 33 000 ± 500 K, while component Ba is an O9 V object with v sin i = 65 ± 3 km s-1and Teff = 33 600 ± 600 K. Based on data products from observations made with ESO telescopes at La Silla Paranal Observatory under programmes 68.D-0095(A), 71.D-0369(A), 073.D-0609(A), 075.D-0061(A), 076.D0294(A), 077.D-0146(A), 079.D-0718(A), 081.D-2008(B), 083.D-0589(B), 086.D-0997(B), 087.D-0946(A), and 089.D-0975(A), extracted from the ESO/ST-ECF Science

  8. Scattering properties of dust in Orion and the Epsilon Eridani exoplanetary system

    NASA Astrophysics Data System (ADS)

    Mendillo, Christopher B.

    Dust grain properties were investigated in two very different Galactic environments: the interstellar medium and an exoplanetary system. Two sounding rocket missions were developed to study these regions. Wide-field observations of the Orion OB stellar association were performed in the far-ultraviolet using the Spectrograph for Photometric Imaging with Numeric Reconstruction (SPINR) sounding rocket. These observations reveal the diffuse signature of starlight scattering off interstellar dust grains. The spectral-imaging data were used along with a three-dimensional radiative transfer model to measure the dust scattering parameters: the grain albedo (a) and the scattering asymmetry ( g). The measured parameters are consistent with previous measurements made toward Orion. A sharp increase in albedo was measured at ˜1330 A. This feature is not explained by current grain models. The constructed three-dimensional model of Orion includes a two-component dust distribution. The foreground distribution is responsible for the small amount of visible reddening measured toward the bright stars in the Orion constellation. The background distribution represents the Orion Molecular Cloud, which dominates observations of dust emission in the infrared. This model was used to show that backscattered light from the molecular cloud alone cannot produce the observed scattered light distribution. The foreground dust, though optically thin in the visible, significantly contributes to the scattered light in the far-ultraviolet. This suggests that observations of Orion in the infrared and far-ultraviolet may probe entirely different dust populations. The Planetary Imaging Concept Testbed Using a Rocket Experiment (PICTURE) sounding rocket was developed to characterize dust grains in the nearby Epsilon Eridani exoplanetary system. This is a young, dusty system with a Jupiter-massed planet orbiting at ˜3.4 AU (astronomical units). PICTURE sought to capture a direct, visible-light image of

  9. Analysis of properties of synthetic mineral microparticles for retention and drainage system

    NASA Astrophysics Data System (ADS)

    Lee, Sa Yong

    Over the past 20 years there has been a revolution involving the use of nano- or macro-sized particles as a component of drainage and retention systems during the manufacture of paper. More recently a group of patented technologies called Synthetic Mineral Microparticles (SMM) has been invented and developed. This system has potential to further promote the drainage of water and retention of fine particles during papermaking. Prior research, as well as our own preliminary research showed that the SMM system has advantages in both of drainage and retention, compared with montmorillonite (bentonite), which is one of the most popular materials presently used in this kind of application. In spite of the demonstrated advantages of this SMM system, the properties and activity of SMM particles in the aqueous state have not been elucidated yet. To help understand the molecular mechanisms involved in SMM technology, streaming current and potentiometric titration were employed to characterize the charge behavior of SMM, depending on the synthetic conditions, which included variation of the Al/Si ratio, partial neutralization of Al species, salt addition and shear rate. Surface area of SMM and the distribution of SMM particle size were investigated with scanning electron microscopy in order to elucidate the relationship between the morphology and coagulation behavior of SMM, versus the pre-stated synthetic conditions, as well as to estimate the optimal conditions to produce SMM as a retention and drainage aid for use during papermaking. Through the streaming current titration experiments it was found that pH variation, caused by the change of Al/Si ratio and partial neutralization of aluminum's acidity, profoundly affects the charge properties of SMM. These effects can be attributed to the variation of Al-ion speciation and the influence ionizable groups on the Si-containing particle surfaces. The relationship between Al/Si ratio and isoelectric pH, measured by potentiometric

  10. THERMODYNAMIC PROPERTIES OF THE METALLIC SYSTEM Au(111)-(3×3)R30∘-Pd

    NASA Astrophysics Data System (ADS)

    Chadli, R.; Kheffache, S.; Khater, A.

    2016-02-01

    This work constitutes an analysis of the thermodynamic properties in the ordered metallic surface alloy system Au(111)-(3×3)R30∘-Pd. The equilibrium structural characteristics as well as the thermodynamic functions are examined by the matching method, associated with real space Green’s function formalism, evaluated in the harmonic approximation. Our numerical results, for this metallic system of surface alloy, show in particular a significant dependence between the thermodynamic properties and the coordination number and the values of the force constants.

  11. Melting Behavior and Chemical Properties of the Iron-Carbon System

    NASA Astrophysics Data System (ADS)

    Prakapenka, V.; Kantor, I.; Kubo, A.; Kuznetsov, A.; Dera, P.; Rivers, M.; Sutton, S.

    2008-12-01

    One of the most challenging experiments related to the laser heating technique in the diamond anvil cell (DAC) is an unambiguous x-ray based detection of melting by recording high quality diffuse x-ray scattering from molten materials at high pressure. Employing a newly developed, advanced, flat top laser heating system at GSECARS, we were able to perform on-line melting experiments at pressures up to 60 GPa. The capability to maintain the molten sample in the DAC for a relatively long time (at least 60 s) allowed us to collect high quality x-ray scattering data suitable for structure analysis even from low-Z molten materials, such as Si, Ge, Fe, Fe3C, Fe7C3 etc. In this work, we focused on the melting behavior and chemical properties of the iron-carbon system at pressures up to ~170 GPa studied with on-line micro x-ray diffraction in a double sided laser heated DAC at GSECARS (Sector 13, APS). Iron carbides (Fe3C, Fe7C3) were synthesized in- situ in the DAC from various mixtures of Fe and C powders with different atomic ratios. We have found that the chemical reaction between iron and carbon takes place independent of the structure of starting phases of iron (fcc or hcp) and carbon (graphite or diamond). The reaction temperature increased gradually from ~1000 K to ~1700 K as pressure increased from 6 GPa to 155 GPa. The melting temperature of iron carbide was found to be systematically lower than for iron by ~300-400 degrees in the pressure range 20-60 GPa. The experimentally measured structure factor and related pair distribution function of iron carbide melt were analyzed and compared with pure iron data at related pressures. High- pressure, high-temperature stability of iron carbide phases at the relevant Earth's mantle-core conditions and physical/chemical properties of iron-carbon melts provide important constraints on models of the formation of D" layer and interactions at the core mantle boundary. Implications of these results for the composition and

  12. The physical properties of z > 2 Lyman limit systems: new constraints for feedback and accretion models

    NASA Astrophysics Data System (ADS)

    Fumagalli, Michele; O'Meara, John M.; Prochaska, J. Xavier

    2016-02-01

    We study the physical properties of a homogeneous sample of 157 optically thick absorption line systems at redshifts ˜1.8-4.4, selected from a high-dispersion spectroscopic survey of Lyman limit systems (LLSs). By means of multiple ionization models and Bayesian techniques, we derive the posterior probability distribution functions for the density, metallicity, temperature and dust content of the absorbing gas. We find that z > 2 LLSs are highly ionized with ionization parameters between -3 ≲ log U ≲ -2, depending on the H I column density. LLSs are characterized by low temperatures (T < 5 × 104K) and reside in dust-poor environments. Between z ˜ 2.5-3.5, ˜80 per cent of the LLSs have physical densities between nH ˜ 10- 3.5-10- 2 cm- 3 for the assumed UV background, but we caution that a degeneracy between the ionization parameter and the intensity of the radiation field prevents robust inference on the density and sizes of LLSs. Conversely, metallicity estimates are less sensitive to the assumptions behind ionization corrections. LLSs at z > 2 are characterized by a broad unimodal distribution over > 4 orders of magnitude, with a peak at log Z/Z⊙ ˜ -2. LLSs are metal poor, significantly less enriched than DLAs, with ˜70 per cent of the metallicity PDF below log Z/Z⊙ ≤ -1.5. The median metallicity of super LLSs with log N_{H I}≥ 19 rapidly evolves with redshift, with a 10-fold increase between z ˜ 2.1-3.6 (˜1.5 Gyr). Based on this sample, we find that LLSs at z = 2.5-3.5 account for ˜15 per cent of all the metals produced by UV-selected galaxies. The implications for theories of cold gas accretion and metal ejection from galaxies are also discussed.

  13. Properties of the Close-in Tertiary in the Quadruple System V401 Cyg

    NASA Astrophysics Data System (ADS)

    Zhu, L.-Y.; Qian, S.-B.; Zhou, X.; Li, L.-J.; Zhao, E.-G.; Liu, L.; Liu, N.-P.

    2013-08-01

    V401 Cyg is a quadruple system in which the spectroscopic signature of a close-in tertiary and a distant visual companion star were reported. Orbital properties of the close-in companion should provide valuable information on the formation of close binaries and stellar dynamical interaction. By analyzing new times of minimum light together with those collected from the literature, we discovered that the observed-calculated (O - C) curve of V401 Cyg shows a cyclic change with a short period of 3.5 yr and a semi-amplitude of 0.00436 days while it undergoes an upward parabolic variation. Those photoelectric and CCD data covered more than two cycles and were analyzed for the light-travel time effect via the presence of the tertiary companion. The mass of the third body was determined to be M 3sin i' = 0.65(± 0.08) M ⊙, which is close to the value estimated from the spectroscopic data (M 3 ~ 0.64 M ⊙). This reveals that the orbital inclination of the tertiary was about i' ~ 90°, indicating that the contact components of V401 Cyg have the possibility of being eclipsed by the tertiary at an orbital distance of about 3.0 AU, and it may be a triply eclipsing hierarchical triple system. The upward parabolic change indicates a period increase at a rate of \\dot{P}=1.5\\times {10^{-7}} revealing a mass transfer from the secondary to the primary (\\dot{M}_{2}=5.9\\times {10^{-8}} M ⊙ yr-1). This is consistent with the predictions of the theory of thermal relaxation oscillation (TRO) suggesting that V401 Cyg is undergoing an expanding-orbit stage in the TRO cycles.

  14. PROPERTIES OF THE CLOSE-IN TERTIARY IN THE QUADRUPLE SYSTEM V401 CYG

    SciTech Connect

    Zhu, L.-Y.; Qian, S.-B.; Zhou, X.; Li, L.-J.; Zhao, E.-G.; Liu, L.; Liu, N.-P.

    2013-08-01

    V401 Cyg is a quadruple system in which the spectroscopic signature of a close-in tertiary and a distant visual companion star were reported. Orbital properties of the close-in companion should provide valuable information on the formation of close binaries and stellar dynamical interaction. By analyzing new times of minimum light together with those collected from the literature, we discovered that the observed-calculated (O - C) curve of V401 Cyg shows a cyclic change with a short period of 3.5 yr and a semi-amplitude of 0.00436 days while it undergoes an upward parabolic variation. Those photoelectric and CCD data covered more than two cycles and were analyzed for the light-travel time effect via the presence of the tertiary companion. The mass of the third body was determined to be M{sub 3}sin i' = 0.65({+-} 0.08) M{sub Sun }, which is close to the value estimated from the spectroscopic data (M{sub 3} {approx} 0.64 M{sub Sun }). This reveals that the orbital inclination of the tertiary was about i' {approx} 90 Degree-Sign , indicating that the contact components of V401 Cyg have the possibility of being eclipsed by the tertiary at an orbital distance of about 3.0 AU, and it may be a triply eclipsing hierarchical triple system. The upward parabolic change indicates a period increase at a rate of (P-dot{sub 2} = 1.5 x 10{sup -7} revealing a mass transfer from the secondary to the primary (M-dot{sub 2} = 5.9 x 10{sup -8} M{sub Sun} yr{sup -1}). This is consistent with the predictions of the theory of thermal relaxation oscillation (TRO) suggesting that V401 Cyg is undergoing an expanding-orbit stage in the TRO cycles.

  15. Thermodynamic properties of solutions in metastable systems under negative or positive pressures

    NASA Astrophysics Data System (ADS)

    Mercury, Lionel; Azaroual, Mohamed; Zeyen, Hermann; Tardy, Yves

    2003-05-01

    Metastable systems are created when the interface between the atmosphere (in which P atm = 1 bar) and water forms a spherical meniscus either concave toward the air (water filling capillaries, wherein P water < P atm) or convex toward the air (fog water droplet, wherein P water > P atm). Soil water, undergoing negative pressure ("capillary potential") remains bound to the solid matrix (instead of flowing downward) by the capillary meniscus, concave toward the undersaturated dry atmosphere. The positive counterpart of tensile water in soils is the pressurized water contained in fine droplets suspended in oversaturated humid air, as in clouds. All these systems are anisobaric domains the phases of which have different pressures. Geochemical consequences of such characteristics are assessed here by calculating the consequences of the positive or negative water potential on the equilibrium constants of reactions taking place in stretched or pressurized aqueous solutions. Thermodynamic properties of aqueous species are obtained by using the TH model, used explicitly for positive pressures but extrapolated to negative ones for soil solutions. It appears that soil water dissolves gases, offering an alternative explanation of the observed enrichment of atmospheric noble gases in groundwater and of carbonic gas in the unsaturated zone below the root zone. Water droplets obviously show the opposite behavior, that is, a decreasing dissolutive capability with decreasing droplet size (water pressure increases), inducing some climatic consequences. An application of this approach to the solid-solution equilibria is performed by comparing experimental solubility of amorphous silica in unsaturated media on the one hand, to theoretical calculations taking account of the negative water pressure on the other hand. This comparison outlines the potential complexity of anisobaric situations in nature and the necessity to develop a suitable approach for solid pressure.

  16. Transport properties near the metal to insulator transition in samarium substituted (Bi,Pb)-2212 system

    SciTech Connect

    Shabna, R.; Sarun, P. M.; Vinu, S.; Syamaprasad, U.

    2009-06-01

    The electrical transport properties of insulating and superconducting samples of Bi{sub 1.7}Pb{sub 0.4}Sr{sub 2-x}Sm{sub x}Ca{sub 1.1}Cu{sub 2.1}O{sub 8+d}elta system is studied across the metal to insulator transition (MIT) region by varying the x values from 0.5 to 1.0 in steps of 0.1. X-ray diffraction analysis, scanning electron microscopy, energy dispersive x-ray analysis (EDAX), and electrical resistivity measurements have been employed for the characterization of all samples. The x-ray and EDAX analyses indicate that samarium (Sm) atoms are incorporated into the crystalline structure of Bi{sub 1.7}Pb{sub 0.4}Sr{sub 2}Ca{sub 1}Cu{sub 2}O{sub 8+d}elta[(Bi,Pb)-2212]. Samples with x<=0.6 undergo superconducting transitions while those with 0.7<=x<=1.0 exhibit semiconducting behavior. The MIT is observed at 0.6system.

  17. Phosphoinositide system-linked serotonin receptor subtypes and their pharmacological properties and clinical correlates.

    PubMed Central

    Pandey, S C; Davis, J M; Pandey, G N

    1995-01-01

    Serotonergic neurotransmission represents a complex mechanism involving pre- and post-synaptic events and distinct 5-HT receptor subtypes. Serotonin (5-HT) receptors have been classified into several categories, and they are termed as 5-HT1, 5-HT2, 5-HT3, 5-HT4, 5-HT5, 5-HT6 and 5-HT7 type receptors. 5-HT1 receptors have been further subdivided into 5-HT1A, 5-HT1B, 5-HT1D, 5-HT1E and 5-HT1F. 5-HT2 receptors have been divided into 5-HT2A, 5-HT2B and 5-HT2C receptors. All 5-HT2 receptor subtypes are linked to the multifunctional phosphoinositide (PI) signalling system. 5-HT3 receptors are considered ion-gated receptors and are also linked to the PI signalling system by an unknown mechanism. The 5-HT2A receptor subtype is the most widely studied of the 5-HT receptors in psychiatric disorders (for example, suicide, depression and schizophrenia) as well as in relation to the mechanism of action of antidepressant drugs. The roles of 5-HT2C and 5-HT3 receptors in psychiatric disorders are less clear. These 5-HT receptors also play an important role in alcoholism. It has been shown that 5-HT2A, 5-HT2C and 5-HT3 antagonists cause attenuation of alcohol intake in animals and humans. However, the exact mechanisms are unknown. The recent cloning of the cDNAs for 5-HT2A, 5-HT2C and 5-HT3 receptors provides the opportunity to explore the molecular mechanisms responsible for the alterations in these receptors during illness as well as pharmacotherapy. This review article will focus on the current research into the pharmacological properties, molecular biology, and clinical correlates of 5-HT2A, 5-HT2C and 5-HT3 receptors. PMID:7786883

  18. Transport properties in a Sb-Te binary topological-insulator system.

    PubMed

    Takagaki, Y; Giussani, A; Tominaga, J; Jahn, U; Calarco, R

    2013-08-28

    Sb-Te layers having various compositions between Sb2Te3 and Sb2Te are grown using molecular beam epitaxy. The structural and electrical properties of the layers change gradually with composition but exhibit a discontinuity involving a bistability. The holes in the layers are generated by Sb bilayers intercalated between Sb2Te3 quintuple layers and their mobility is governed by the scattering from the parent acceptors. Magnetoresistance for compositions around SbTe is linear, for which the reduction of the parabolic component due to low mobility is crucial. Density functional calculations predict Sb2Te3 and SbTe to be topological insulators (TIs) resembling Bi2Se3 and Bi2Te3, respectively. The prefactor of the weak antilocalization effect is α =- 1 regardless of the composition. The Sb-Te system is thus a family of TIs possessing undisturbed surface states for which the location of the Dirac point with respect to the bulk band gap is adjustable. PMID:23883483

  19. Estimated PDFs of climate system properties including natural and anthropogenic forcings

    NASA Astrophysics Data System (ADS)

    Forest, Chris E.; Stone, Peter H.; Sokolov, Andrei P.

    2006-01-01

    We present revised probability density functions (PDF) for climate system properties (climate sensitivity, rate of deep-ocean heat uptake, and the net aerosol forcing strength) that include the effect on 20th century temperature changes of natural as well as anthropogenic forcings. The additional natural forcings, primarily the cooling by volcanic eruptions, affect the PDF by requiring a higher climate sensitivity and a lower rate of deep-ocean heat uptake to reproduce the observed temperature changes. The estimated 90% range of climate sensitivity is 2.1 to 8.9 K. The net aerosol forcing strength for the 1980s shifted toward positive values to compensate for the volcanic forcing with 90% bounds of -0.74 to -0.14 W/m2. The rate of deep-ocean heat uptake is reduced with the effective diffusivity, Kv, ranging from 0.05 to 4.1 cm2/s. This upper bound implies that many AOGCMs mix heat into the deep ocean (below the mixed layer) too efficiently.

  20. Magnetotransport properties of 2D fermionic systems with k-cubic Rashba spin-orbit interaction

    NASA Astrophysics Data System (ADS)

    Mawrie, Alestin; Biswas, Tutul; Kanti Ghosh, Tarun

    2014-10-01

    The spin-orbit interaction in heavy hole gas formed at p-doped semiconductor heterojunctions and electron gas at SrTiO3 surfaces is cubic in momentum. Here we report magnetotransport properties of k-cubic Rashba spin-orbit coupled 2D fermionic systems. We study longitudinal and Hall components of the resistivity tensor analytically as well as numerically. The longitudinal resistivity shows a beating pattern due to different Shubnikov-de Haas (SdH) oscillation frequencies f± for spin-up and spin-down fermions. We propose empirical forms of f± as exact expressions are not available, which are being used to find locations of the beating nodes. The beating nodes and the number of oscillations between any two successive nodes obtained from exact numerical results are in excellent agreement with those calculated from the proposed empirical formula. In the Hall resistivity, an additional Hall plateau appears between the two conventional ones as the spin-orbit coupling constant increases. The width of this additional plateau increases with spin-orbit coupling constant.

  1. Physicochemical properties of polymers: An important system to overcome the cell barriers in gene transfection.

    PubMed

    Namvar, Ali; Bolhassani, Azam; Khairkhah, Niloofardokht; Motevalli, Fatemeh

    2015-07-01

    Delivery of the macromolecules including DNA, miRNA, and antisense oligonucleotides is typically mediated by carriers due to the large size and negative charge. Different physical (e.g., gene gun or electroporation), and chemical (e.g., cationic polymer or lipid) vectors have been already used to improve the efficiency of gene transfer. Polymer-based DNA delivery systems have attracted special interest, in particular via intravenous injection with many intra- and extracellular barriers. The recent progress has shown that stimuli-responsive polymers entitled as multifunctional nucleic acid vehicles can act to target specific cells. These nonviral carriers are classified by the type of stimulus including reduction potential, pH, and temperature. Generally, the physicochemical characterization of DNA-polymer complexes is critical to enhance the transfection potency via protection of DNA from nuclease digestion, endosomal escape, and nuclear localization. The successful clinical applications will depend on an exact insight of barriers in gene delivery and development of carriers overcoming these barriers. Consequently, improvement of novel cationic polymers with low toxicity and effective for biomedical use has attracted a great attention in gene therapy. This article summarizes the main physicochemical and biological properties of polyplexes describing their gene transfection behavior, in vitro and in vivo. In this line, the relative efficiencies of various cationic polymers are compared. PMID:25761628

  2. The Potential Field of Carbon Bodies as a Basis for Sorption Properties of Barrier Gas Systems

    NASA Astrophysics Data System (ADS)

    Bubenchikov, A. M.; Bubenchikov, M. A.; Potekaev, A. I.; Libin, É. E.; Khudobina, Yu. P.

    2015-11-01

    A modification of the Lennard-Jones potential allowed us, via integration over the volume of the bodies of different shapes, to determine the integral action (potential energy barrier) generated by the distributed force centers. The body generating the potential barrier was a carbon plate and the test particles overcoming this barrier were atoms or molecules of a number of gases (hydrogen, helium and methane). When considering the transit of particles (gas atoms or molecules) over this barrier, use was made of the energy barrier wave theory and the potential of a continuous body was used as a barrier. In so doing, the Schrödinger equation was integrated numerically for the molecular density. This integration yielded the expected wave pattern of the process of transit and reflection of the molecules, so a phase averaging procedure had to be applied. By varying the parameters of the layer containing force centers - field sources, the dimensions and density of the carbon plate possessing high selectivity towards separation of gas mixture containing helium, hydrogen and methane were determined. The data obtained provide an interpretation of the sorption properties of barrier carbon systems capable of filtering or separating gases.

  3. Nickel Oxide Nanoparticles Doped Liquid Crystal System for Superior Electro-Optical Properties.

    PubMed

    Lee, Hak Moo; Chung, Hyung-Koo; Park, Hong-Gyu; Jeong, Hae-Chang; Kim, Jeong-Hwan; Park, Tae-Kyu; Seo, Dae-Shik

    2015-10-01

    We examined the properties of nematic liquid crystal (N-LC) systems with dispersed nickel oxide nanoparticles (NPs). Uniform LC alignments with regular pretilt angles were achieved on rubbed polymer surface regardless of NiO nanoparticles concentration. We confirmed the electro-optical characteristics of twisted nematic (TN) cells containing NiO nanoparticles on rubbed polymer surface, which exhibited lower threshold voltages and faster response times with less capacitance hysteresis than pure LC cells. It is clear that the response time of TN cells on rubbed polymer surfaces decreases with increasing the NiO nanoparticles concentration. These results demonstrate the relationship between NP doping concentration and trapping of impurity ions, and were confirmed by a software simulation of electric flux and field density. NiO nanoparticles in the LC cells focused the electric field flux and strengthened the electric field. Further, NiO nanoparticles in LC medium trapped charged ionic impurities and suppressed the screen effect, leading to a stronger electric field and the van der Waals interactions between LC molecules and the alignment layers. PMID:26726476

  4. Corrosion and its effect on mechanical properties of materials for advanced combustion systems

    SciTech Connect

    Natesan, K.; Freeman, M.; Mathur, M.

    1996-05-01

    Conceptual designs of advanced combustion systems that utilize coal as a feedstock require high-temperature furnaces and heat transfer surfaces that can operate at temperatures much higher than those prevalent in current coal-fired power plants. The combination of elevated temperatures and hostile combustion environments necessitates development and application of advanced ceramic materials in these designs. The objectives of the present program are to evaluate (a) the chemistry of gaseous and condensed products that arise during combustion of coal; (b) the corrosion behavior of candidate materials in air, slag and salt environments for application in the combustion environments; and (c) the residual mechanical properties of the materials after corrosion. The program emphasizes temperatures in the range of 1000-1400{degrees}C for ceramic materials and 600-1000{degrees}C for metallic alloys. Coal/ash chemistries developed on the basis of thermodynamic/kinetic calculations, together with slags from actual combustors, are used in the program. The materials being evaluated include monolithic silicon carbide from several sources: silicon, nitride, silicon carbide in alumina composites, silicon carbide fibers in a silicon carbide- matrix composite, and some advanced nickel-base alloys. The paper presents results from an ongoing program on corrosion performance of candidate ceramic materials exposed to air, salt and slag environments and their affect on flexural strength and energy absorbed during fracture of these materials.

  5. Room temperature shear properties of the strain isolator pad for the shuttle thermal protection system

    NASA Technical Reports Server (NTRS)

    Sawyer, J. W.; Waters, W. A., Jr.

    1981-01-01

    Tests were conducted at room temperature to determine the shear properties of the strain isolator pad (SIP) material used in the thermal protection system of the space shuttle. Tests were conducted on both the .23 cm and .41 cm thick SIP material in the virgin state and after fifty fully reversed shear cycles. The shear stress displacement relationships are highly nonlinear, exhibit large hysteresis effects, are dependent on material orientation, and have a large low modulus region near the zero stress level where small changes in stress can result in large displacements. The values at the higher stress levels generally increase with normal and shear force load conditioning. Normal forces applied during the shear tests reduces the low modulus region for the material. Shear test techniques which restrict the normal movement of the material give erroneous stress displacement results. However, small normal forces do not significantly effect the shear modulus for a given shear stress. Poisson's ratio values for the material are within the range of values for many common materials. The values are not constant but vary as a function of the stress level and the previous stress history of the material. Ultimate shear strengths of the .23 cm thick SIP are significantly higher than those obtained for the .41 cm thick SIP.

  6. Electronic Properties of Polarizable Systems with Self-Consistent Interatomic van der Waals Density Functional

    NASA Astrophysics Data System (ADS)

    Ferri, Nicola; Distasio, Robert A., Jr.; Ambrosetti, Alberto; Car, Roberto; Scheffler, Matthias; Tkatchenko, Alexandre

    2015-03-01

    Ubiquitous long-range van der Waals (vdW) interactions play a fundamental role in the structure and stability of a wide range of systems. Within the DFT framework, the vdW energy represents a crucial, but tiny part of the total energy, hence its influence on the electronic density, n (r) , and electronic properties is typically assumed to be rather small. Here, we address this question via a fully self-consistent (SC) implementation of the interatomic Tkatchenko-Scheffler vdW functional and its extension to surfaces. Self-consistency leads to large changes in the binding energies and electrostatic moments of highly polarizable alkali metal dimers. For some metal surfaces, vdW interactions increase dipole moments and induce non-trivial charge rearrangements, leading to visible changes in the metal workfunctions. Similar behavior is observed for molecules adsorbed on metals. Our study reveals a non-trivial connection between electrostatics and long-range electron correlation effects.

  7. The stabilities, electronic structures and elastic properties of Rb—As systems

    NASA Astrophysics Data System (ADS)

    Havva Bogaz, Ozisik; Kemal, Colakoglu; Engin, Deligoz; Haci, Ozisik

    2012-04-01

    The structural, electronic and elastic properties of Rb—As systems (RbAs in NaP, LiAs and AuCu structures, RbAs2 in the MgCu2 structure, Rb3As in Na3As, Cu3P and Li3Bi structures, and Rb5As4 in the A5B4 structure) are investigated with the generalized gradient approximation in the frame of density functional theory. The lattice parameters, cohesive energies, formation energies, bulk moduli and the first derivatives of the bulk moduli (to fit Murnaghan's equation of state) of the considered structures are calculated and reasonable agreement is obtained. In addition, the phase transition pressures are also predicted. The electronic band structures, the partial densities of states corresponding to the band structures and the charge density distributions are presented and analysed. The second-order elastic constants based on the stress-strain method and other related quantities such as Young's modulus, the shear modulus, Poisson's ratio, sound velocities, the Debye temperature and shear anisotropy factors are also estimated.

  8. Influence of different crosslinking systems on the mechanical and morphological properties of thermoplastic vulcanizates

    NASA Astrophysics Data System (ADS)

    Patermann, Simone; Altstädt, Volker

    2015-05-01

    Thermoplastic vulcanizates (TPVs) combine the elastic properties of thermoset cross-linked rubbers with the melt processability of thermoplastics. The most representative examples of this class are the TPVs based on polypropylene (PP) and ethylene-propylene-diene terpolymer rubber (EPDM). The PP/EPDM blends were produced by dynamic vulcanization in a continuous extrusion process. The influence of different crosslinking systems was studied with regard to cross-link density, compression set, tensile strength/elongation at break and morphology. With increasing peroxide concentration, the cross-link density increases, leading to a reduction of the compression set by 50 %. The same improvement is only reachable with twice the concentration of phenolic resin. Only the peroxide cross-linked blends show smaller dispersed EPDM particles with increasing peroxide concentration. With a peroxide concentration between 0.2 and 0.5 wt. %, a maximum in tensile strength and elongation at break was found. For the phenolic resin cross-linked blends, the tensile strength stays almost constant with increasing phenolic resin concentration and the elongation at break shows best results at 0.5 wt. % phenolic resin. Compared to batch processes, the results show different values, but comparable trends.

  9. Formyl peptide receptors from immune and vomeronasal system exhibit distinct agonist properties.

    PubMed

    Bufe, Bernd; Schumann, Timo; Zufall, Frank

    2012-09-28

    The formyl peptide receptor (Fpr) family is well known for its contribution to immune defense against pathogens in human and rodent leukocytes. Recently, several structurally related members of these receptors were discovered in sensory neurons of the mouse vomeronasal organ (VNO), key detectors of pheromones and related semiochemicals. Although the biological role of vomeronasal Fprs is not yet clear, the known contribution of other Fprs to host immune defense suggested that they could contribute to vomeronasal pathogen sensing. Precise knowledge about the agonist properties of mouse Fprs is required to determine their function. We expressed all seven mouse and three human Fprs using an in vitro system and tested their activation with 32 selected compounds by conducting high throughput calcium measurements. We found an intriguing functional conservation between human and mouse immune Fprs that is most likely a consequence of closely similar biological constraints. By contrast, our data suggest a neofunctionalization of the vomeronasal Fprs. We show that the vomeronasal receptor mFpr-rs1 can be activated robustly by W-peptide and structural derivatives but not by other typical ligands of immune Fprs. mFpr-rs1 exhibits a stereo-selective preference for peptides containing d-amino acids. The same peptide motifs are contained in pathogenic microorganisms. Thus, the ligand profile of mFpr-rs1 is consistent with a role in vomeronasal pathogen sensing. PMID:22859307

  10. The relationship of physicochemical properties to the antioxidative activity of free amino acids in Fenton system.

    PubMed

    Milić, Sonja; Bogdanović Pristov, Jelena; Mutavdžić, Dragosav; Savić, Aleksandar; Spasić, Mihajlo; Spasojević, Ivan

    2015-04-01

    Herein we compared antioxidative activities (AA) of 25 free L-amino acids (FAA) against Fenton system-mediated hydroxyl radical (HO(•)) production in aqueous solution, and examined the relation between AA and a set of physicochemical properties. The rank order according to AA was: Trp > norleucine > Phe, Leu > Ile > His >3,4-dihydroxyphenylalanine, Arg > Val > Lys, Tyr, Pro > hydroxyproline > α-aminobutyric acid > Gln, Thr, Ser > Glu, Ala, Gly, Asn, Asp. Sulfur-containing FAA generated different secondary reactive products, which were discriminated by the means of electron paramagnetic resonance spin-trapping spectroscopy. AA showed a general positive correlation with hydrophobicity. However, when taken separately, uncharged FAA exhibited strong positive correlation of AA with hydrophobicity whereas charged FAA showed negative or no significant correlation depending on the scale applied. A general strong negative correlation was found between AA and polarity. Steric parameters and hydration numbers correlated positively with AA of nonpolar side-chain FAA. In addition, a decrease of temperature which promotes hydrophobic hydration resulted in increased AA. This implies that HO(•)-provoked oxidation of FAA is strongly affected by hydrophobic hydration. Our findings are important for the understanding of oxidation processes in natural and waste waters. PMID:25764263

  11. Initial Validation and Results of Geoscience Laser Altimeter System Optical Properties Retrievals

    NASA Technical Reports Server (NTRS)

    Hlavka, Dennis L.; Hart, W. D.; Pal, S. P.; McGill, M.; Spinhirne, J. D.

    2004-01-01

    Verification of Geoscience Laser Altimeter System (GLAS) optical retrievals is . problematic in that passage over ground sites is both instantaneous and sparse plus space-borne passive sensors such as MODIS are too frequently out of sync with the GLAS position. In October 2003, the GLAS Validation Experiment was executed from NASA Dryden Research Center, California to greatly increase validation possibilities. The high-altitude NASA ER-2 aircraft and onboard instrumentation of Cloud Physics Lidar (CPL), MODIS Airborne Simulator (MAS), and/or MODIS/ASTER Airborne Simulator (MASTER) under-flew seven orbit tracks of GLAS for cirrus, smoke, and urban pollution optical properties inter-comparisons. These highly calibrated suite of instruments are the best data set yet to validate GLAS atmospheric parameters. In this presentation, we will focus on the inter-comparison with GLAS and CPL and draw preliminary conclusions about the accuracies of the GLAS 532nm retrievals of optical depth, extinction, backscatter cross section, and calculated extinction-to-backscatter ratio. Comparisons to an AERONET/MPL ground-based site at Monterey, California will be attempted. Examples of GLAS operational optical data products will be shown.

  12. A critical appraisal of the zero-multipole method: Structural, thermodynamic, dielectric, and dynamical properties of a water system

    NASA Astrophysics Data System (ADS)

    Wang, Han; Nakamura, Haruki; Fukuda, Ikuo

    2016-03-01

    We performed extensive and strict tests for the reliability of the zero-multipole (summation) method (ZMM), which is a method for estimating the electrostatic interactions among charged particles in a classical physical system, by investigating a set of various physical quantities. This set covers a broad range of water properties, including the thermodynamic properties (pressure, excess chemical potential, constant volume/pressure heat capacity, isothermal compressibility, and thermal expansion coefficient), dielectric properties (dielectric constant and Kirkwood-G factor), dynamical properties (diffusion constant and viscosity), and the structural property (radial distribution function). We selected a bulk water system, the most important solvent, and applied the widely used TIP3P model to this test. In result, the ZMM works well for almost all cases, compared with the smooth particle mesh Ewald (SPME) method that was carefully optimized. In particular, at cut-off radius of 1.2 nm, the recommended choices of ZMM parameters for the TIP3P system are α ≤ 1 nm-1 for the splitting parameter and l = 2 or l = 3 for the order of the multipole moment. We discussed the origin of the deviations of the ZMM and found that they are intimately related to the deviations of the equilibrated densities between the ZMM and SPME, while the magnitude of the density deviations is very small.

  13. Defining Desirable Central Nervous System Drug Space through the Alignment of Molecular Properties, in Vitro ADME, and Safety Attributes

    PubMed Central

    2010-01-01

    As part of our effort to increase survival of drug candidates and to move our medicinal chemistry design to higher probability space for success in the Neuroscience therapeutic area, we embarked on a detailed study of the property space for a collection of central nervous system (CNS) molecules. We carried out a thorough analysis of properties for 119 marketed CNS drugs and a set of 108 Pfizer CNS candidates. In particular, we focused on understanding the relationships between physicochemical properties, in vitro ADME (absorption, distribution, metabolism, and elimination) attributes, primary pharmacology binding efficiencies, and in vitro safety data for these two sets of compounds. This scholarship provides guidance for the design of CNS molecules in a property space with increased probability of success and may lead to the identification of druglike candidates with favorable safety profiles that can successfully test hypotheses in the clinic. PMID:22778836

  14. Investigations on the usefulness of the Massively Parallel Processor for study of electronic properties of atomic and condensed matter systems

    NASA Technical Reports Server (NTRS)

    Das, T. P.

    1988-01-01

    The usefulness of the Massively Parallel Processor (MPP) for investigation of electronic structures and hyperfine properties of atomic and condensed matter systems was explored. The major effort was directed towards the preparation of algorithms for parallelization of the computational procedure being used on serial computers for electronic structure calculations in condensed matter systems. Detailed descriptions of investigations and results are reported, including MPP adaptation of self-consistent charge extended Hueckel (SCCEH) procedure, MPP adaptation of the first-principles Hartree-Fock cluster procedure for electronic structures of large molecules and solid state systems, and MPP adaptation of the many-body procedure for atomic systems.

  15. Analytic properties of two-photon scattering matrix in integrated quantum systems determined by the cluster decomposition principle.

    PubMed

    Xu, Shanshan; Rephaeli, Eden; Fan, Shanhui

    2013-11-27

    We consider a general class of integrated quantum systems where photon-photon interaction occurs in a quantum device that is localized in space. Using techniques that are closely related to cluster decomposition principles in quantum field theory, we provide a general constraint on the analytic properties of a two-photon S matrix in this class of systems. We also show that the photon-photon interaction in these systems inevitably leads to frequency mixing and entanglement and that frequencies of the single photons cannot be preserved in these systems. PMID:24329447

  16. Nano-scale Studies of the Assembly, Structure and Properties of Hybrid Organic-Silicon Systems

    NASA Astrophysics Data System (ADS)

    Sinha, Shoma

    Advancements in the field of electronics might be achieved by future molecular scale devices. Hybrid organic-silicon structures have the potential to overcome many challenges facing the use of molecules as devices while maintaining the ability to interface with traditional silicon technology. The objective of this dissertation was to advance our base knowledge of the interactions, behaviour and properties of simple molecular systems and the Si(100):2 × 1 surface. Experimental studies conducted with scanning tunneling microscopy (STM) and complemented with theoretical investigations, primarily density functional theory (DFT), were utilized to investigate three principle areas of interest: (1) the transport behaviour of monolayers, patterned regions, or nanostructures, (2) surface diffusion and (3) properties of self-assembled molecular lines. The tunneling current versus applied bias behaviour of the clean, the monohydride and the styrene passivated Si(100):2 × 1 surfaces were studied. An energy band model was formed that incorporates surface dipole characteristics and band bending to describe tunneling current transport. The transport behaviour from patterns of clean, styrene covered, and 4-fluorostyrene covered Si(100):2 × 1 on otherwise monohydride terminated Si(100):2 × 1 were subsequently studied. Comparison with the observations from the full monolayers provided evidence for conduction through surface states. Studies of the transport behaviour of styrene molecular lines were also performed. Surface diffusion is an important aspect of self-assembly. A novel experimental method for studying aspects of diffusion that removes STM tip effects was developed and used to study the diffusion anisotropy of styrene and 4-uorostyrene on HSi( 100):2 × 1. These studies were complemented with DFT energy calculations and Monte Carlo methods to incorporate dynamic effects. Various studies were conducted on self-assembled molecular lines. In addition to studying the

  17. An Invitro Evaluation of Antibacterial Properties of Self Etching Dental Adhesive Systems

    PubMed Central

    Rekha A, Sri; Poppuri, Krishna Chaitanya; Prashanth P, Sai; Garapati, Surendranath

    2014-01-01

    Background and Objectives: The microbial flora of the oral cavity is extremely diverse. Residual bacteria in the oral cavity may remain at the tooth restoration interface and increase the risk of developing recurrent caries. The aim of this study is to evaluate the immediate and long term antibacterial effect of polymerised self etching adhesive systems. Materials and Methods: Streptococcus mutans were used as a test organism. The self etching dental adhesives that were used are Adper Easy One, G-Bond, Clearfil S3 bond and Xeno V. Agar diffusion test (ADT) was performed on agar plates, in which four holes that were 4mm in diameter were punched. Then 200 μL of freshly grown S.mutans spread evenly. The four holes were immediately filled with the four tested materials and light polymerised them using a light curing unit. The agar plates were incubated for 72h at 37°C. For the direct contact test (DCT), the bonding agents were placed on the side walls of microtiter plate wells and light polymerized according to the manufacturer’s instructions. A 10μL bacterial suspension was placed on the tested material samples. Bacteria were allowed to directly contact the polymerized dental adhesives for 1h at 37oC. Fresh Brain heart infusion broth was then added. The bacterial growth was then spectrophotometrically measured in the wells every 30 min for 16h for 1,2, 7 and 14 days. Results: In the ADT, inhibitory halos were found around all the bonding agents, with greater inhibition halo seen around Xeno V after incubating for 72 h at 37°C. The readings obtained through DCT were subjected to ANOVA and Tukey’s multiple comparisons tests, which showed no bacterial growth on fresh samples and after aging for one day in PBS with self etching adhesives. Results of DCT after aging for 2 days, 7 days and 14 days showed bacterial growth in all the bonding agents used with no significant difference from the control group.(p<0.001) Conclusion: All the dental adhesives showed

  18. A family of models of partially relaxed stellar systems. I. Dynamical properties

    NASA Astrophysics Data System (ADS)

    Trenti, M.; Bertin, G.

    2005-01-01

    Recently we have found that a family of models of partially relaxed, anisotropic stellar systems, inspired earlier by studies of incomplete violent relaxation, exhibits some interesting thermodynamic properties. Here we present a systematic investigation of its dynamical characteristics, in order to establish the basis for a detailed comparison with simulations of collisionless collapse, planned for a separate paper. For a full comparison with the observations of elliptical galaxies, the models should be extended to allow for the presence a sizable dark halo and of significant rotation. In the spherical limit, the family is characterized by two dimensionless parameters, i.e. Ψ, measuring the depth of the galaxy potential, and ν, defining the form of a third global quantity Q, which is argued to be approximately conserved during collisionless collapse (in addition to the total energy and the total number of stars). The family of models is found to have the following properties. The intrinsic density profile beyond the half-mass radius r_M is basically universal and independent of Ψ. The projected density profiles are well fitted by the R1/n law, with n ranging from 2.5 to 8.5, dependent on Ψ, with n close to 4 for concentrated models. All models exhibit radial anisotropy in the pressure tensor, especially in their outer parts, already significant at r ≈ r_M. At fixed values of ν, models with lower Ψ are more anisotropic; at fixed values of Ψ, models with lower ν are more concentrated and more anisotropic. When the global amount of anisotropy, measured by 2K_r/K_T, is large, the models are unstable with respect to the radial-orbit instability; still, a wide region of parameter space (i.e., sufficiently high values of Ψ, for ν > 3/8) is covered by models that are dynamically stable; for these, the line profiles (line-of-sight velocity distribution) are Gaussian at the 5% level, with a general trend of positive values of h_4 at radii larger than the

  19. Quantum theory of the electronic and optical properties of low-dimensional semiconductor systems

    NASA Astrophysics Data System (ADS)

    Lau, Wayne Heung

    This thesis examines the electronic and optical properties of low-dimensional semiconductor systems. A theory is developed to study the electron-hole generation-recombination process of type-II semimetallic semiconductor heterojunctions based on a 3 x 3 k·p matrix Hamiltonian (three-band model) and an 8 x 8 k·p matrix Hamiltonian (eight-band model). A novel electron-hole generation and recombination process, which is called activationless generation-recombination process, is predicted. It is demonstrated that the current through the type-II semimetallic semiconductor heterojunctions is governed by the activationless electron-hole generation-recombination process at the heterointerfaces, and that the current-voltage characteristics are essentially linear. A qualitative agreement between theory and experiments is observed. The numerical results of the eight-band model are compared with those of the threeband model. Based on a lattice gas model, a theory is developed to study the influence of a random potential on the ionization equilibrium conditions for bound electron-hole pairs (excitons) in III--V semiconductor heterostructures. It is demonstrated that ionization equilibrium conditions for bound electron-hole pairs change drastically in the presence of strong disorder. It is predicted that strong disorder promotes dissociation of excitons in III--V semiconductor heterostructures. A theory of polariton (photon dressed by phonon) spontaneous emission in a III--V semiconductor doped with semiconductor quantum dots (QDs) or quantum wells (QWs) is developed. For the first time, superradiant and subradiant polariton spontaneous emission phenomena in a polariton-QD (QW) coupled system are predicted when the resonance energies of the two identical QDs (QWs) lie outside the polaritonic energy gap. It is also predicted that when the resonance energies of the two identical QDs (QWs) lie inside the polaritonic energy gap, spontaneous emission of polariton in the polariton

  20. Physical properties of the WASP-67 planetary system from multi-colour photometry

    NASA Astrophysics Data System (ADS)

    Mancini, L.; Southworth, J.; Ciceri, S.; Calchi Novati, S.; Dominik, M.; Henning, Th.; Jørgensen, U. G.; Korhonen, H.; Nikolov, N.; Alsubai, K. A.; Bozza, V.; Bramich, D. M.; D'Ago, G.; Figuera Jaimes, R.; Galianni, P.; Gu, S.-H.; Harpsøe, K.; Hinse, T. C.; Hundertmark, M.; Juncher, D.; Kains, N.; Popovas, A.; Rabus, M.; Rahvar, S.; Skottfelt, J.; Snodgrass, C.; Street, R.; Surdej, J.; Tsapras, Y.; Vilela, C.; Wang, X.-B.; Wertz, O.

    2014-08-01

    Context. The extrasolar planet WASP-67 b is the first hot Jupiter definitively known to undergo only partial eclipses. The lack of the second and third contact points in this planetary system makes it difficult to obtain accurate measurements of its physical parameters. Aims: By using new high-precision photometric data, we confirm that WASP-67 b shows grazing eclipses and compute accurate estimates of the physical properties of the planet and its parent star. Methods: We present high-quality, multi-colour, broad-band photometric observations comprising five light curves covering two transit events, obtained using two medium-class telescopes and the telescope-defocusing technique. One transit was observed through a Bessel-R filter and the other simultaneously through filters similar to Sloan g'r'i'z'. We modelled these data using jktebop. The physical parameters of the system were obtained from the analysis of these light curves and from published spectroscopic measurements. Results: All five of our light curves satisfy the criterion for being grazing eclipses. We revise the physical parameters of the whole WASP-67 system and, in particular, significantly improve the measurements of the planet's radius (Rb = 1.091 ± 0.046 RJup) and density (ρb = 0.292 ± 0.036 ρJup), as compared to the values in the discovery paper (Rb = 1.4 -0.2+0.3 RJup and ρb = 0.16 ± 0.08 ρJup). The transit ephemeris was also substantially refined. We investigated the variation of the planet's radius as a function of the wavelength, using the simultaneous multi-band data, finding that our measurements are consistent with a flat spectrum to within the experimental uncertainties. Based on data collected with GROND at the MPG 2.2 m telescope and DFOSC at the Danish 1.54 m telescope.Full Table 2 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/568/A127