Science.gov

Sample records for existing application modes

  1. Existence of non zero modes in an annular lined duct

    NASA Astrophysics Data System (ADS)

    Balint, Agneta M.; Balint, Stefan; Tanasie, Loredana

    2012-11-01

    The purpose is to extend Vilenski - Rienstra's [32] results concerning mainly the general aspects of the existence of non zero modes in annular lined ducts. The case, when the radial and circumferential components of the mean flow are equal to zero and the axial component depends only on the distance to the duct axis, is investigated. Conditions for the existence of non zero modes, which satisfy the linearized homogeneous Euler equations (obtained by linearization around the mean flow) and the boundary conditions, (corresponding to the perturbation - liner interaction of mass-spring-damper type) are found. The first condition, called dispersion relation, is expressed in terms of the solutions of two normalized initial value problems and is equivalent to the linear dependence of these solutions. It is shown that the set of non zero modes, corresponding to a given frequency and given axial and circumferential wave number, is either the null space, either is a one dimensional function space. It is shown also that if the mean flow is symmetric with respect to the "center of the ring", then neither symmetric, nor anti-symmetric modes exist. This difference between the annular and rectangular or circular lined duct models explains while one of the boundary conditions can not be transferred in the center of symmetry. For symmetric flow, being constant in the "central part of the ring", new dispersion relations are derived. The new relations beside the solutions of the two normalized initial value problems incorporate also modified Bessel functions or additional Bessel functions. The Lyapunov stability of the mean flow with respect to the initial value perturbation by mode type perturbations is discussed in terms of the zero's of the dispersion relation.

  2. 46 CFR 117.15 - Applicability to existing vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Applicability to existing vessels. 117.15 Section 117.15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE... AND ARRANGEMENTS General Provisions § 117.15 Applicability to existing vessels. An existing...

  3. 46 CFR 179.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Applicability to existing vessels. 179.115 Section 179.115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER... Applicability to existing vessels. An existing vessel must comply with the subdivision, damage stability,...

  4. 46 CFR 179.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Applicability to existing vessels. 179.115 Section 179.115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER... Applicability to existing vessels. An existing vessel must comply with the subdivision, damage stability,...

  5. 46 CFR 117.15 - Applicability to existing vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Applicability to existing vessels. 117.15 Section 117.15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE... AND ARRANGEMENTS General Provisions § 117.15 Applicability to existing vessels. An existing...

  6. 46 CFR 180.15 - Applicability to existing vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... condition. (c) An existing vessel need not comply with § 180.78(a)(4). (d) An existing vessel must comply... 46 Shipping 7 2014-10-01 2014-10-01 false Applicability to existing vessels. 180.15 Section 180.15... TONS) LIFESAVING EQUIPMENT AND ARRANGEMENTS General Provisions § 180.15 Applicability to...

  7. 46 CFR 180.15 - Applicability to existing vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Applicability to existing vessels. 180.15 Section 180.15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) LIFESAVING EQUIPMENT AND ARRANGEMENTS General Provisions § 180.15 Applicability to existing vessels. An existing vessel must comply...

  8. 46 CFR 179.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 100 GROSS TONS) SUBDIVISION, DAMAGE STABILITY, AND WATERTIGHT INTEGRITY General Provisions § 179.115 Applicability to existing vessels. An existing vessel must comply with the subdivision, damage stability,...

  9. 46 CFR 179.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 100 GROSS TONS) SUBDIVISION, DAMAGE STABILITY, AND WATERTIGHT INTEGRITY General Provisions § 179.115 Applicability to existing vessels. An existing vessel must comply with the subdivision, damage stability,...

  10. 46 CFR 178.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Applicability to existing vessels. 178.115 Section 178.115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER... existing vessels. Except where specifically stated otherwise, an existing vessel must comply with...

  11. 46 CFR 178.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Applicability to existing vessels. 178.115 Section 178.115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER... existing vessels. Except where specifically stated otherwise, an existing vessel must comply with...

  12. 28 CFR 0.32 - Applicability of existing departmental regulations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 1 2013-07-01 2013-07-01 false Applicability of existing departmental regulations. 0.32 Section 0.32 Judicial Administration DEPARTMENT OF JUSTICE ORGANIZATION OF THE DEPARTMENT OF JUSTICE Community Relations Service § 0.32 Applicability of existing departmental...

  13. 46 CFR 119.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Applicability to existing vessels. 119.115 Section 119.115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING... INSTALLATION General Provisions § 119.115 Applicability to existing vessels. (a) Except as otherwise...

  14. 46 CFR 183.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Applicability to existing vessels. 183.115 Section 183.115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) ELECTRICAL INSTALLATION General Provisions § 183.115 Applicability to existing...

  15. 46 CFR 120.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Applicability to existing vessels. 120.115 Section 120.115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING... INSTALLATION General Provisions § 120.115 Applicability to existing vessels. (a) Except as otherwise...

  16. 46 CFR 116.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Applicability to existing vessels. 116.115 Section 116.115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING... ARRANGEMENT General Provisions § 116.115 Applicability to existing vessels. (a) Except as otherwise...

  17. 46 CFR 119.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Applicability to existing vessels. 119.115 Section 119.115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING... INSTALLATION General Provisions § 119.115 Applicability to existing vessels. (a) Except as otherwise...

  18. 46 CFR 120.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Applicability to existing vessels. 120.115 Section 120.115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING... INSTALLATION General Provisions § 120.115 Applicability to existing vessels. (a) Except as otherwise...

  19. 46 CFR 116.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Applicability to existing vessels. 116.115 Section 116.115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING... ARRANGEMENT General Provisions § 116.115 Applicability to existing vessels. (a) Except as otherwise...

  20. 46 CFR 183.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Applicability to existing vessels. 183.115 Section 183.115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) ELECTRICAL INSTALLATION General Provisions § 183.115 Applicability to existing...

  1. 46 CFR 177.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Applicability to existing vessels. 177.115 Section 177.115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER... vessels. (a) Except as otherwise required by paragraph (b) of this section, an existing vessel must...

  2. 46 CFR 180.15 - Applicability to existing vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Applicability to existing vessels. 180.15 Section 180.15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS... vessels. An existing vessel must comply with the requirements of this part except as otherwise...

  3. 46 CFR 180.15 - Applicability to existing vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Applicability to existing vessels. 180.15 Section 180.15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS... vessels. An existing vessel must comply with the requirements of this part except as otherwise...

  4. 46 CFR 177.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Applicability to existing vessels. 177.115 Section 177.115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER... vessels. (a) Except as otherwise required by paragraph (b) of this section, an existing vessel must...

  5. Existence of multisite intrinsic localized modes in one-dimensional Debye crystals

    SciTech Connect

    Koukouloyannis, V.; Kourakis, I.

    2007-07-15

    The existence of highly localized multisite oscillatory structures (discrete multibreathers) in a nonlinear Klein-Gordon chain which is characterized by an inverse dispersion law is proven and their linear stability is investigated. The results are applied in the description of vertical (transverse, off-plane) dust grain motion in dusty plasma crystals, by taking into account the lattice discreteness and the sheath electric and/or magnetic field nonlinearity. Explicit values from experimental plasma discharge experiments are considered. The possibility for the occurrence of multibreathers associated with vertical charged dust grain motion in strongly coupled dusty plasmas (dust crystals) is thus established. From a fundamental point of view, this study aims at providing a rigorous investigation of the existence of intrinsic localized modes in Debye crystals and/or dusty plasma crystals and, in fact, suggesting those lattices as model systems for the study of fundamental crystal properties.

  6. 40 CFR 35.937-11 - Applicability to existing contracts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Applicability to existing contracts. 35.937-11 Section 35.937-11 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works-Clean Water...

  7. 46 CFR 184.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Applicability to existing vessels. 184.115 Section 184.115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) VESSEL CONTROL AND MISCELLANEOUS SYSTEMS AND EQUIPMENT General Provisions §...

  8. 46 CFR 121.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Applicability to existing vessels. 121.115 Section 121.115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150 PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS VESSEL...

  9. 46 CFR 184.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Applicability to existing vessels. 184.115 Section 184.115 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) VESSEL CONTROL AND MISCELLANEOUS SYSTEMS AND EQUIPMENT General Provisions §...

  10. 46 CFR 117.15 - Applicability to existing vessels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Applicability to existing vessels. 117.15 Section 117.15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150 PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS LIFESAVING EQUIPMENT AND ARRANGEMENTS General Provisions...

  11. Expanded mode lasers for telecommunications applications

    NASA Astrophysics Data System (ADS)

    Lealman, Ian F.

    This thesis describes the development of a long wavelength (1.55 μm) expanded mode semiconductor laser. The increased spot size of the laser improves both the coupling efficiency to cleaved fibre and fibre alignment tolerances and reduces packaging cost. In this type of device the strength of the waveguide is gradually reduced towards the front facet allowing the mode to adiabatically expand so that the laser mode is better matched in size to that of a cleaved fibre. This can be achieved by either reducing the refractive index of the guide or reducing the amount of material in the core. The structure chosen was a buried heterostructure laser that utilised a twin guide consisting of an upper higher refractive index guide (the active region of the laser) above a weak passive guide. The width of the active region was reduced along part of the device allowing the mode to expand into the weak underlying guide. The guide structure was optimised using a variable grid finite difference mode solver, and the taper length calculated by an approximation to Love's method. Detailed results are presented for the measured light-current characteristic, farfield and coupling loss to cleaved fibre. These coupling losses were compared to the calculated data thus allowing the waveguide design to be optimised. Several iterations in the design of the device were undertaken, with the aim of reducing the coupling loss to cleaved single mode fibre without significantly compromising the laser performance. The final device design had extremely low coupling losses as low as 1.2 dB to cleaved fibre. Finally, the positive impact this device had on passive alignment using a silicon motherboard is examined, and the application this technology to a range of other optoelectronic components is discussed.

  12. Adding pluggable and personalized natural control capabilities to existing applications.

    PubMed

    Lamberti, Fabrizio; Sanna, Andrea; Carlevaris, Gilles; Demartini, Claudio

    2015-01-01

    Advancements in input device and sensor technologies led to the evolution of the traditional human-machine interaction paradigm based on the mouse and keyboard. Touch-, gesture- and voice-based interfaces are integrated today in a variety of applications running on consumer devices (e.g., gaming consoles and smartphones). However, to allow existing applications running on desktop computers to utilize natural interaction, significant re-design and re-coding efforts may be required. In this paper, a framework designed to transparently add multi-modal interaction capabilities to applications to which users are accustomed is presented. Experimental observations confirmed the effectiveness of the proposed framework and led to a classification of those applications that could benefit more from the availability of natural interaction modalities. PMID:25635410

  13. Adding Pluggable and Personalized Natural Control Capabilities to Existing Applications

    PubMed Central

    Lamberti, Fabrizio; Sanna, Andrea; Carlevaris, Gilles; Demartini, Claudio

    2015-01-01

    Advancements in input device and sensor technologies led to the evolution of the traditional human-machine interaction paradigm based on the mouse and keyboard. Touch-, gesture- and voice-based interfaces are integrated today in a variety of applications running on consumer devices (e.g., gaming consoles and smartphones). However, to allow existing applications running on desktop computers to utilize natural interaction, significant re-design and re-coding efforts may be required. In this paper, a framework designed to transparently add multi-modal interaction capabilities to applications to which users are accustomed is presented. Experimental observations confirmed the effectiveness of the proposed framework and led to a classification of those applications that could benefit more from the availability of natural interaction modalities. PMID:25635410

  14. Existing computer applications, maintain or redesign: how to decide

    SciTech Connect

    Brice, L.

    1981-01-01

    Maintenance of large applications programs is an aspect of performance management that has been largely ignored by those studies that attempt to bring structure to the software production environment. Maintenance in this paper means: fixing bugs, modifying current design features, adding enhancements, and porting applications to other computer systems. It is often difficult to decide whether to maintain or redesign. One reason for the difficulty is that good models and methods do not exist for differentiating between those programs that should be maintained and those that should be redesigned. This enigma is illustrated by the description of a large application case study. The application was monitored for maintenance effort, thereby providing some insight into the redesign/maintain decision. Those tools which currently exist for the collection and measurement of performance data are highlighted. Suggestions are then made for yet other categories of data, difficult to collect and measure, yet ultimately necessary for the establishment of accurate predictions about the value of maintaining versus the value of redesigning. Finally, it is concluded that this aspect of performance management deserves increased attention in order to establish better guidelines with which to aid management in making the necessary but difficult decision: maintain or redesign.

  15. Dielectric elastomers: generator mode fundamentals and applications

    NASA Astrophysics Data System (ADS)

    Pelrine, Ron; Kornbluh, Roy D.; Eckerle, Joseph; Jeuck, Philip; Oh, Seajin; Pei, Qibing; Stanford, Scott

    2001-07-01

    Dielectric elastomers have shown great promise as actuator materials. Their advantages in converting mechanical to electrical energy in a generator mode are less well known. If a low voltage charge is placed on a stretched elastomer prior to contraction, the contraction works against the electrostatic field pressure and raises the voltage of the charge, thus generating electrical energy. This paper discusses the fundamentals of dielectric elastomer generators, experimental verification of the phenomenon, practical issues, and potential applications. Acrylic elastomers have demonstrated an estimated 0.4 J/g specific energy density, greater than that of piezoelectric materials. Much higher energy densities, over 1 J/g, are predicted. Conversion efficiency can also be high, theoretically up to 80-90%; the paper discusses the operating conditions and materials required for high efficiency. Practical considerations may limit the specific outputs and efficiencies of dielectric elastomeric generators, tradeoffs between electronics and generator material performance are discussed. Lastly, the paper describes work on potential applications such as an ongoing effort to develop a boot generator based on dielectric elastomers, as well as other applications such as conventional power generators, backpack generators, and wave power applications.

  16. Dual mode nuclear rocket system applications.

    NASA Technical Reports Server (NTRS)

    Boretz, J. E.; Bell, J. M.; Plebuch, R. K.; Priest, C. C.

    1972-01-01

    Mission areas where the dual-mode nuclear rocket system is superior to nondual-mode systems are demonstrated. It is shown that the dual-mode system is competitive with the nondual-mode system even for those specific missions and particular payload configurations where it does not have a clear-cut advantage.

  17. Space structure vibration modes: How many exist? Which ones are important?

    NASA Technical Reports Server (NTRS)

    Hughes, P. C.

    1984-01-01

    This report attempts to shed some light on the two issues raised in the title, namely, how many vibration modes does a real structure have, and which of these modes are important? The surprise-free answers to these two questions are, respectively, an infinite number and the first several modes. The author argues that the absurd subspace (all but the first billion modes) is not a strength of continuum modeling, but, in fact, a weakness. Partial differential equations are not real structures, only mathematical models. This note also explains (1) that the PDE model and the finite element model are, in fact, the same model, the latter being a numerical method for dealing with the former, (2) that modes may be selected on dynamical grounds other than frequency alone, and (3) that long slender rods are useful as primitive cases but dangerous to extrapolate from.

  18. Dual mode stereotactic localization method and application

    DOEpatents

    Keppel, Cynthia E.; Barbosa, Fernando Jorge; Majewski, Stanislaw

    2002-01-01

    The invention described herein combines the structural digital X-ray image provided by conventional stereotactic core biopsy instruments with the additional functional metabolic gamma imaging obtained with a dedicated compact gamma imaging mini-camera. Before the procedure, the patient is injected with an appropriate radiopharmaceutical. The radiopharmaceutical uptake distribution within the breast under compression in a conventional examination table expressed by the intensity of gamma emissions is obtained for comparison (co-registration) with the digital mammography (X-ray) image. This dual modality mode of operation greatly increases the functionality of existing stereotactic biopsy devices by yielding a much smaller number of false positives than would be produced using X-ray images alone. The ability to obtain both the X-ray mammographic image and the nuclear-based medicine gamma image using a single device is made possible largely through the use of a novel, small and movable gamma imaging camera that permits its incorporation into the same table or system as that currently utilized to obtain X-ray based mammographic images for localization of lesions.

  19. Research of application mode for FTTX technology

    NASA Astrophysics Data System (ADS)

    Wang, Zhong; Yun, Xiang; Huang, Wei

    2009-08-01

    With rapid development of Internet and broadband access network, the technologies of xDSL, FTTx+LAN, WLAN have more applications, new network service emerges in endless stream, especially the increase of network game, meeting TV, video on demand, etc. FTTH supports all present and future service with enormous bandwidth, including traditional telecommunication service, traditional data service and traditional TV service, and the future digital TV and VOD. With huge bandwidth of FTTH, it wins the final solution of broadband network, becomes the final goal of development of optical access network. In this paper, technique theory of EPON is introduced at first. At the same time, MAC frame structure, automatic detection and ranging of MPCP, DBA,and multi-LLID of EPON is analyzed. Then, service development ability, cost advantage and maintenance superiority based on EPON technology are carried out. At last,with Cost comparison between FTTH / FTTB building model and the traditional model, FTTB + LAN mode which is suitable for the newadding residential users in general areas and FTTN + DSL mode which is suitable for the old city and rural access network transformation are built up in detail. And FTTN + DSL project of rural information in rural areas and FTTH broadband HOUSE project on service solutions program are analyzed. comparing to the traditional access technologies, EPON technology has the obvious advantages, such as distance transmission, high or wide band, saving line resources, service abilities, etc. These are the qualities which not only be served for home users, but solve more access problems for us effectively.

  20. Turbulence in the Interplanetary Medium: Can Discrete Modes Co-Exist With Turbulence?

    SciTech Connect

    Ghosh, S.; Thomson, D. J.; Matthaeus, W. H.; Lanzerotti, L. J.

    2011-01-04

    Spacecraft observations during the last decade suggest the presence of discrete frequency wave-like signals embedded in turbulent solar wind fluctuations. A basic plasma physics question immediately arises how a single monochromatic wave mode can survive in the presence of magnetofluid turbulence. Early one- and two-dimensional magnetofluid simulation studies appear to refute the observations by showing that discrete modes are destroyed within fractions of a characteristic nonlinear time scale. Here we readdress the problem using fully-compressible three-dimensional magnetofluid simulations. We investigate the persistence of discrete wave-like spatial structures in the presence of strong low-frequency turbulence and seek to identify the time scales and other conditions that permit them to remain as identifiable modes in the turbulent medium. We find that discrete modes can survive from one to many nonlinear times, and that the two main factors that determine their survivability is the presence of a mean magnetic field and sufficient scale separation in parallel wavenumber between the discrete mode's wavelength and the length scales of the turbulence.

  1. Existence of two MHD reconnection modes in a solar 3D magnetic null point topology

    NASA Astrophysics Data System (ADS)

    Pariat, Etienne; Antiochos, Spiro; DeVore, C. Richard; Dalmasse, Kévin

    2012-07-01

    Magnetic topologies with a 3D magnetic null point are common in the solar atmosphere and occur at different spatial scales: such structures can be associated with some solar eruptions, with the so-called pseudo-streamers, and with numerous coronal jets. We have recently developed a series of numerical experiments that model magnetic reconnection in such configurations in order to study and explain the properties of jet-like features. Our model uses our state-of-the-art adaptive-mesh MHD solver ARMS. Energy is injected in the system by line-tied motion of the magnetic field lines in a corona-like configuration. We observe that, in the MHD framework, two reconnection modes eventually appear in the course of the evolution of the system. A very impulsive one, associated with a highly dynamic and fully 3D current sheet, is associated with the energetic generation of a jet. Before and after the generation of the jet, a quasi-steady reconnection mode, more similar to the standard 2D Sweet-Parker model, presents a lower global reconnection rate. We show that the geometry of the magnetic configuration influences the trigger of one or the other mode. We argue that this result carries important implications for the observed link between observational features such as solar jets, solar plumes, and the emission of coronal bright points.

  2. Earth resources survey applications of the space shuttle sortie mode

    NASA Technical Reports Server (NTRS)

    Sharma, R. D.; Smith, W. L.; Thomson, F. J.

    1973-01-01

    The use of the shuttle sortie mode for earth observation applications was investigated and its feasibility for applied research and instrument development was appraised. The results indicate that the shuttle sortie missions offer unique advantages and that specific aspects of earth applications are particularly suited to the sortie mode.

  3. Condition for the existence of complex modes in a trapped Bose-Einstein condensate with a highly quantized vortex

    NASA Astrophysics Data System (ADS)

    Mine, Makoto; Fukuyama, Eriko; Okumura, Masahiko; Sunaga, Tomoka; Yamanaka, Yoshiya

    2008-03-01

    We consider a trapped Bose-Einstein condensate (BEC) with a highly quantized vortex. For the BEC with a doubly, triply, or quadruply quantized vortex, the numerical calculations have shown that the Bogoliubov-de Gennes equations, which describe the fluctuation of the condensate, have complex eigenvalues. In this talk, we show the analytic expression of the condition for the existence of complex modes, using the method developed by Rossignoli and Kowalski^1 for the small coupling constant. To derive it, we make the two-mode approximation. With the derived analytic formula, we can identify the quantum numbers of the complex modes for each winding number of the vortex^2. Our result is consistent with those obtained by the numerical calculation in the case that the winding number is two, three, or four. We prove that the complex modes always exist when the condensate has a highly quantized vortex^2. ^1 R. Rossignoli and A. M. Kowalski, Phys. Rev. A 72, 032101 (2005). ^2 E. Fukuyama, M. Mine, M. Okumura, T. Sunaga and Y. Yamanaka, Phys. Rev. A 76, 043608 (2007).

  4. 30 CFR 778.9 - Certifying and updating existing permit application information.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... EXPLORATION SYSTEMS UNDER REGULATORY PROGRAMS PERMIT APPLICATIONS-MINIMUM REQUIREMENTS FOR LEGAL, FINANCIAL, COMPLIANCE, AND RELATED INFORMATION § 778.9 Certifying and updating existing permit application...

  5. 30 CFR 778.9 - Certifying and updating existing permit application information.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... EXPLORATION SYSTEMS UNDER REGULATORY PROGRAMS PERMIT APPLICATIONS-MINIMUM REQUIREMENTS FOR LEGAL, FINANCIAL, COMPLIANCE, AND RELATED INFORMATION § 778.9 Certifying and updating existing permit application...

  6. 30 CFR 778.9 - Certifying and updating existing permit application information.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... EXPLORATION SYSTEMS UNDER REGULATORY PROGRAMS PERMIT APPLICATIONS-MINIMUM REQUIREMENTS FOR LEGAL, FINANCIAL, COMPLIANCE, AND RELATED INFORMATION § 778.9 Certifying and updating existing permit application...

  7. 30 CFR 778.9 - Certifying and updating existing permit application information.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... EXPLORATION SYSTEMS UNDER REGULATORY PROGRAMS PERMIT APPLICATIONS-MINIMUM REQUIREMENTS FOR LEGAL, FINANCIAL, COMPLIANCE, AND RELATED INFORMATION § 778.9 Certifying and updating existing permit application...

  8. 30 CFR 778.9 - Certifying and updating existing permit application information.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... EXPLORATION SYSTEMS UNDER REGULATORY PROGRAMS PERMIT APPLICATIONS-MINIMUM REQUIREMENTS FOR LEGAL, FINANCIAL, COMPLIANCE, AND RELATED INFORMATION § 778.9 Certifying and updating existing permit application...

  9. 46 CFR 182.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... must comply with the regulations on machinery, bilge and ballast system equipment, steering apparatus..., bilge and ballast system equipment, steering equipment, and piping systems or components on an existing... flash point of 43.3 °C (110 °F) or lower must comply with the requirements of § 182.410(c) on or...

  10. Mode-Locked Laser Arrays for WDM Applications

    NASA Technical Reports Server (NTRS)

    Forouhar, S.

    1997-01-01

    Colliding pulse mode-locked laser arrays are being developed at 20 GHz for WDM applications. Arrays with 5 wavelengths in the EDFA gain bandwidth have already been demonstrated, with the final goal being a packaged, 10 wavelength mode-locked laser array.

  11. Adaptation of existing infrared technologies to unanticipated applications

    NASA Astrophysics Data System (ADS)

    Peng, Philip

    2005-01-01

    Radiation thermometry is just but one of many applications, both potential and realized, of infrared technology. During the SARS (Severe Acute Respiratory Syndromes) global crisis in 2003, the technology was utilized as a preliminary screening method for infected persons as a defense against a major outbreak, as the primary symptom of this disease is elevated body temperature. ATC timely developed a product designed specifically for mass volume crowd screening of febrile individuals. For this application, the machine must register temperature of subjects rapidly and efficiently, with a certain degree of accuracy, and function for extended periods of time. The equipment must be safe to use, easily deployed, and function with minimum maintenance needed. The ATIR-303 model satisfies all of the above and other pre-requisite conditions amicably. Studies on the correlation between the maximum temperature registered among individual's facial features, as measured under the conditions of usage, and the core temperature of individuals were performed. The results demonstrated that ATIR-303 is very suitable for this application. Other applications of the infrared technology in various areas, like medical diagnosis, non-destructive testing, security, search and rescue, and others, are also interest areas of ATC. The progress ATC has achieved in these areas is presented also.

  12. A Simple test for the existence of two accretion modes in active galactic nuclei

    SciTech Connect

    Jester, Sebastian; /Fermilab

    2005-02-01

    By analogy to the different accretion states observed in black-hole X-ray binaries (BHXBs), it appears plausible that accretion disks in active galactic nuclei (AGN) undergo a state transition between a radiatively efficient and inefficient accretion flow. If the radiative efficiency changes at some critical accretion rate, there will be a change in the distribution of black hole masses and bolometric luminosities at the corresponding transition luminosity. To test this prediction, the author considers the joint distribution of AGN black hole masses and bolometric luminosities for a sample taken from the literature. The small number of objects with low Eddington-scaled accretion rates m < 0.01 and black hole masses M{sub BH} < 10{sup 9} M{sub {circle_dot}} constitutes tentative evidence for the existence of such a transition in AGN. Selection effects, in particular those associated with flux-limited samples, systematically exclude objects in particular regions of the (M{sub BH}, L{sub bol}) plane. Therefore, they require particular attention in the analysis of distributions of black hole mass, bolometric luminosity, and derived quantities like the accretion rate. The author suggests further observational tests of the BHXB-AGN unification scheme which are based on the jet domination of the energy output of BHXBs in the hard state, and on the possible equivalence of BHXB in the very high (or steep power-law) state showing ejections and efficiently accreting quasars and radio galaxies with powerful radio jets.

  13. Application of component mode synthesis in structural dynamics

    NASA Technical Reports Server (NTRS)

    Craig, R. R.

    1986-01-01

    The principal analytical techniques used for component mode synthesis (CMS) of undamped systems and their application to structural dynamics are discussed. In the CMS, a system is divided into components or substructures, and for each of these components, the number of degrees of freedom is reduced by expressing the physical coordinates in terms of a reduced set of component modal coordinates. Among a number of component modes, a new form of component mode, called an applied force attachment mode, is described. Consideration is given to literature studies of damped structures and recent combined analytical/experimental studies.

  14. Application of existing design software to problems in neuronal modeling.

    PubMed

    Vranić-Sowers, S; Fleshman, J W

    1994-03-01

    In this communication, we describe the application of the Valid/Analog Design Tools circuit simulation package called PC Workbench to the problem of modeling the electrical behavior of neural tissue. A nerve cell representation as an equivalent electrical circuit using compartmental models is presented. Several types of nonexcitable and excitable membranes are designed, and simulation results for different types of electrical stimuli are compared to the corresponding analytical data. It is shown that the hardware/software platform and the models developed constitute an accurate, flexible, and powerful way to study neural tissue. PMID:8045583

  15. Mixed-mode chromatography in pharmaceutical and biopharmaceutical applications.

    PubMed

    Zhang, Kelly; Liu, Xiaodong

    2016-09-01

    Mixed-mode chromatography (MMC) is a fast growing area in recent years, thanks to the new generation of mixed-mode stationary phases and better understanding of multimode interactions. MMC has superior applications in the separation of compounds that are not retained or not well resolved by typical reversed-phase LC methods, especially for polar and charged molecules. Due to the multiple retention modes that a single MMC column can offer, often MMC provides additional dimension to a separation method by adjusting the mobile phase conditions. Mixed-mode media is also an effective way to clean up complex sample matrices for purification purposes or for sensitive detection of trace amounts of analytes. In this article, we discuss mixed-mode stationary phases and separation mechanisms and review recent advances in pharmaceutical and biopharmaceutical applications including the analysis and/or purification of counterions, small molecule drugs, impurities, formulation excipients, peptides and proteins. PMID:27236100

  16. TOPICAL REVIEW: Normal mode analysis and applications in biological physics

    NASA Astrophysics Data System (ADS)

    Dykeman, Eric C.; Sankey, Otto F.

    2010-10-01

    Normal mode analysis has become a popular and often used theoretical tool in the study of functional motions in enzymes, viruses, and large protein assemblies. The use of normal modes in the study of these motions is often extremely fruitful since many of the functional motions of large proteins can be described using just a few normal modes which are intimately related to the overall structure of the protein. In this review, we present a broad overview of several popular methods used in the study of normal modes in biological physics including continuum elastic theory, the elastic network model, and a new all-atom method, recently developed, which is capable of computing a subset of the low frequency vibrational modes exactly. After a review of the various methods, we present several examples of applications of normal modes in the study of functional motions, with an emphasis on viral capsids.

  17. Cusps and cuspidal edges at fluid interfaces: Existence and application.

    PubMed

    Krechetnikov, R

    2015-04-01

    One of the intriguing questions in fluid dynamics is on the interrelation between dynamic singularities in the solutions of fluid dynamic equations - unboundedness of the velocity field in an appropriate norm - and the geometric ones - divergence of curvature at fluid interfaces. The present work focuses on two generic interfacial singularities - genuine cusps and cuspidal edges - found here in both two and three dimensions thus establishing a relation between real fluid interfaces and geometric singularity theory. The key finding is the necessary condition for the existence of geometric singularities, which is a variation of surface tension. It is also established here that the dynamic and geometric singularities entail each other only in the case of three-dimensional cusps. Explicit asymptotic solutions for the flow field and interface shape near steady-state singularities at fluid interfaces are developed as well. The practical motivation for the present study comes from the fundamental role interfacial singularities play in sustaining self-driven conversion of chemical into mechanical energy. PMID:25974592

  18. Incoporating Existing Large Applications in the PUPIL System: Amber

    NASA Astrophysics Data System (ADS)

    Trickey, Sam; Torras Costa, Juan; Seabra, Gustavo De Miranda; Roitberg, Adrian; Deumens, E.

    2007-03-01

    PUPIL (Program for User Package Interfacing and Linking)^1 inter-operates existing codes for multi-threaded, multi-scale quantum and classical mechanical simulations via JAVA, XML, JAVA, a C++ library, and minimally intrusive wrappers for each code. An architectural challenge for PUPIL is support of modules from a multi-scale QM-MD suite with much internal coupling. We have succeeded with the AMBER suite MD module (Sander), with Gaussian03 for QM. Our demonstration study is the decomposition of Angelis' salt with explict water. A variable quantum zone (solute and first solvation cell) was used, with the remaining waters via TIP3P. Sander calculated the Potential of Mean Force for the reaction through umbrella sampling, with the QM forces from Gaussian. We summarize PUPIL architecture and implementation aspects, report efficiency and overhead measures, and discuss the computed results. ^1J. Torras, E. Deumens and S.B. Trickey, J. Computer Aided Mat. Des. 13, 201 (2006); J. Torras et al. Comp. Phys. Comm. 2006 [accepted

  19. Cusps and cuspidal edges at fluid interfaces: Existence and application

    NASA Astrophysics Data System (ADS)

    Krechetnikov, R.

    2015-04-01

    One of the intriguing questions in fluid dynamics is on the interrelation between dynamic singularities in the solutions of fluid dynamic equations - unboundedness of the velocity field in an appropriate norm - and the geometric ones - divergence of curvature at fluid interfaces. The present work focuses on two generic interfacial singularities - genuine cusps and cuspidal edges - found here in both two and three dimensions thus establishing a relation between real fluid interfaces and geometric singularity theory. The key finding is the necessary condition for the existence of geometric singularities, which is a variation of surface tension. It is also established here that the dynamic and geometric singularities entail each other only in the case of three-dimensional cusps. Explicit asymptotic solutions for the flow field and interface shape near steady-state singularities at fluid interfaces are developed as well. The practical motivation for the present study comes from the fundamental role interfacial singularities play in sustaining self-driven conversion of chemical into mechanical energy.

  20. Cusps and cuspidal edges at fluid interfaces: existence and application

    NASA Astrophysics Data System (ADS)

    Krechetnikov, Rouslan

    2015-11-01

    One of the intriguing questions in fluid dynamics is on the interrelation between dynamic singularities in the solutions of fluid dynamic equations - unboundedness of the velocity field in an appropriate norm - and the geometric ones - divergence of curvature at fluid interfaces. The present talk focuses on two generic interfacial singularities - genuine cusps and cuspidal edges - found here in both two and three dimensions thus establishing a relation between real fluid interfaces and geometric singularity theory. The key new finding is the necessary condition for the existence of geometric singularities, which is a variation of surface tension. It is also established here that the dynamic and geometric singularities entail each other only in the case of three-dimensional cusps. Explicit asymptotic solutions for the flow field and interface shape near steady-state singularities at fluid interfaces are developed as well. The practical motivation for the present study comes from the fundamental role interfacial singularities play in sustaining self-driven conversion of chemical into mechanical energy.

  1. Mode-distribution analysis of quasielastic neutron scattering and application to liquid water

    NASA Astrophysics Data System (ADS)

    Kikuchi, Tatsuya; Nakajima, Kenji; Ohira-Kawamura, Seiko; Inamura, Yasuhiro; Yamamuro, Osamu; Kofu, Maiko; Kawakita, Yukinobu; Suzuya, Kentaro; Nakamura, Mitsutaka; Arai, Masatoshi

    2013-06-01

    A quasielastic neutron scattering (QENS) experiment is a particular technique that endeavors to define a relationship between time and space for the diffusion dynamics of atoms and molecules. However, in most cases, analyses of QENS data are model dependent, which may distort attempts to elucidate the actual diffusion dynamics. We have developed a method for processing QENS data without a specific model, wherein all modes can be described as combinations of the relaxations based on the exponential law. By this method, we can obtain a distribution function B(Q,Γ), which we call the mode-distribution function (MDF), to represent the number of relaxation modes and distributions of the relaxation times in the modes. The deduction of MDF is based on the maximum entropy method and is very versatile in QENS data analysis. To verify this method, reproducibility was checked against several analytical models, such as that with a mode of distributed relaxation time, that with two modes closely located, and that represented by the Kohlrausch-Williams-Watts function. We report the first application to experimental data of liquid water. In addition to the two known modes, the existence of a relaxation mode of water molecules with an intermediate time scale has been discovered. We propose that the fast mode might be assigned to an intermolecular motion and the intermediate motion might be assigned to a rotational motion of the water molecules instead of to the fast mode.

  2. WEBnm@: a web application for normal mode analyses of proteins

    PubMed Central

    Hollup, Siv Midtun; Salensminde, Gisle; Reuter, Nathalie

    2005-01-01

    Background Normal mode analysis (NMA) has become the method of choice to investigate the slowest motions in macromolecular systems. NMA is especially useful for large biomolecular assemblies, such as transmembrane channels or virus capsids. NMA relies on the hypothesis that the vibrational normal modes having the lowest frequencies (also named soft modes) describe the largest movements in a protein and are the ones that are functionally relevant. Results We developed a web-based server to perform normal modes calculations and different types of analyses. Starting from a structure file provided by the user in the PDB format, the server calculates the normal modes and subsequently offers the user a series of automated calculations; normalized squared atomic displacements, vector field representation and animation of the first six vibrational modes. Each analysis is performed independently from the others and results can be visualized using only a web browser. No additional plug-in or software is required. For users who would like to analyze the results with their favorite software, raw results can also be downloaded. The application is available on . We present here the underlying theory, the application architecture and an illustration of its features using a large transmembrane protein as an example. Conclusion We built an efficient and modular web application for normal mode analysis of proteins. Non specialists can easily and rapidly evaluate the degree of flexibility of multi-domain protein assemblies and characterize the large amplitude movements of their domains. PMID:15762993

  3. Resonant mode controllers for launch vehicle applications

    NASA Technical Reports Server (NTRS)

    Schreiner, Ken E.; Roth, Mary Ellen

    1992-01-01

    Electro-mechanical actuator (EMA) systems are currently being investigated for the National Launch System (NLS) as a replacement for hydraulic actuators due to the large amount of manpower and support hardware required to maintain the hydraulic systems. EMA systems in weight sensitive applications, such as launch vehicles, have been limited to around 5 hp due to system size, controller efficiency, thermal management, and battery size. Presented here are design and test data for an EMA system that competes favorably in weight and is superior in maintainability to the hydraulic system. An EMA system uses dc power provided by a high energy density bipolar lithium thionyl chloride battery, with power conversion performed by low loss resonant topologies, and a high efficiency induction motor controlled with a high performance field oriented controller to drive a linear actuator.

  4. Second-order sliding mode control with experimental application.

    PubMed

    Eker, Ilyas

    2010-07-01

    In this article, a second-order sliding mode control (2-SMC) is proposed for second-order uncertain plants using equivalent control approach to improve the performance of control systems. A Proportional + Integral + Derivative (PID) sliding surface is used for the sliding mode. The sliding mode control law is derived using direct Lyapunov stability approach and asymptotic stability is proved theoretically. The performance of the closed-loop system is analysed through an experimental application to an electromechanical plant to show the feasibility and effectiveness of the proposed second-order sliding mode control and factors involved in the design. The second-order plant parameters are experimentally determined using input-output measured data. The results of the experimental application are presented to make a quantitative comparison with the traditional (first-order) sliding mode control (SMC) and PID control. It is demonstrated that the proposed 2-SMC system improves the performance of the closed-loop system with better tracking specifications in the case of external disturbances, better behavior of the output and faster convergence of the sliding surface while maintaining the stability. PMID:20413118

  5. Existence of travelling wave solutions for a Fisher-Kolmogorov system with biomedical applications

    NASA Astrophysics Data System (ADS)

    Belmonte-Beitia, Juan

    2016-07-01

    We consider a Fisher-Kolmogorov system with applications in oncology Pérez-García et al. (2015). Of interest is the question of the existence of travelling front solutions of the system. When the speed of the travelling wave is sufficiently large, existence of such fronts is shown using singular geometric perturbation theory.

  6. 76 FR 69766 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-09

    ...Section 101(c) of the Federal Mine Safety and Health Act of 1977 and 30 CFR part 44 govern the application, processing, and disposition of petitions for modification. This notice is a summary of petitions for modification submitted to the Mine Safety and Health Administration (MSHA) by the parties listed below to modify the application of existing mandatory safety standards codified in Title......

  7. 78 FR 69135 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-18

    ...Section 101(c) of the Federal Mine Safety and Health Act of 1977 and 30 CFR part 44 govern the application, processing, and disposition of petitions for modification. This notice is a summary of petitions for modification submitted to the Mine Safety and Health Administration (MSHA) by the parties listed below to modify the application of existing mandatory safety standards codified in Title......

  8. 77 FR 30555 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-23

    ...Section 101(c) of the Federal Mine Safety and Health Act of 1977 and 30 CFR Part 44 govern the application, processing, and disposition of petitions for modification. This notice is a summary of petitions for modification submitted to the Mine Safety and Health Administration (MSHA) by the parties listed below to modify the application of existing mandatory safety standards codified in Title......

  9. 77 FR 19722 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-02

    ...Section 101(c) of the Federal Mine Safety and Health Act of 1977 and 30 CFR Part 44 govern the application, processing, and disposition of petitions for modification. This notice is a summary of petitions for modification submitted to the Mine Safety and Health Administration (MSHA) by the parties listed below to modify the application of existing mandatory safety standards codified in Title......

  10. 76 FR 69764 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-09

    ...Section 101(c) of the Federal Mine Safety and Health Act of 1977 and 30 CFR part 44 govern the application, processing, and disposition of petitions for modification. This notice is a summary of petitions for modification submitted to the Mine Safety and Health Administration (MSHA) by the parties listed below to modify the application of existing mandatory safety standards codified in Title......

  11. 77 FR 810 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-06

    ...Section 101(c) of the Federal Mine Safety and Health Act of 1977 and 30 CFR part 44 govern the application, processing, and disposition of petitions for modification. This notice is a summary of petitions for modification submitted to the Mine Safety and Health Administration (MSHA) by the parties listed below to modify the application of existing mandatory safety standards codified in Title......

  12. 78 FR 42977 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-18

    ...Section 101(c) of the Federal Mine Safety and Health Act of 1977 and 30 CFR part 44 govern the application, processing, and disposition of petitions for modification. This notice is a summary of petitions for modification submitted to the Mine Safety and Health Administration (MSHA) by the parties listed below to modify the application of existing mandatory safety standards codified in Title......

  13. 77 FR 77113 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-31

    ... Safety and Health Administration Petitions for Modification of Application of Existing Mandatory Safety Standards AGENCY: Mine Safety and Health Administration, Labor. ACTION: Notice. SUMMARY: Section 101(c) of the Federal Mine Safety and Health Act of 1977 and 30 CFR part 44 govern the application,...

  14. 78 FR 23308 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-18

    ...Section 101(c) of the Federal Mine Safety and Health Act of 1977 and 30 CFR part 44 govern the application, processing, and disposition of petitions for modification. This notice is a summary of petitions for modification submitted to the Mine Safety and Health Administration (MSHA) by the parties listed below to modify the application of existing mandatory safety standards codified in Title......

  15. 78 FR 7458 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-01

    ...Section 101(c) of the Federal Mine Safety and Health Act of 1977 and 30 CFR Part 44 govern the application, processing, and disposition of petitions for modification. This notice is a summary of petitions for modification submitted to the Mine Safety and Health Administration (MSHA) by the parties listed below to modify the application of existing mandatory safety standards codified in Title......

  16. A Mixed-Mode I/II Fracture Criterion and Its Application in Crack Growth Predictions

    NASA Technical Reports Server (NTRS)

    Sutton, Michael A.; Deng, Xiaomin; Ma, Fashang; Newman, James S., Jr.

    1999-01-01

    A crack tip opening displacement (CTOD)-based, mixed mode fracture criterion is developed for predicting the onset and direction of crack growth. The criterion postulates that crack growth occurs in either the Mode I or Mode II direction, depending on whether the maximum in either the opening or the shear component of CTOD, measured at a specified distance behind the crack tip, attains a critical value. For crack growth direction prediction, the proposed CTOD criterion is shown to be equivalent to seven commonly used crack growth criteria under linearly elastic and asymptotic conditions. Under elastic-plastic conditions the CTOD criterion's prediction of the dependence of the crack growth direction on the crack-up mode mixity is in excellent agreement with the Arcan test results. Furthermore, the CTOD criterion correctly predicts the existence of a crack growth transition from mode I to mode II as the mode mixity approaches the mode II loading condition. The proposed CTOD criterion has been implemented in finite element crack growth simulation codes Z1P2DL and FRANC2DL to predict the crack growth paths in (a) a modified Arcan test specimen and fixture made of AL 2024-T34 and (b) a double cantilever beam (DCB) specimen made of AL 7050. A series of crack growth simulations have been carried out for the crack growth tests in the Arcan and DCB specimens and the results further demonstrate the applicability of the mixed mode CTOD fracture criterion crack growth predictions and residual strength analyses for airframe materials.

  17. Injection seeded single mode alexandrite ring laser for lidar applications

    NASA Technical Reports Server (NTRS)

    Lee, H. Sang; Notari, Anthony

    1992-01-01

    Along with many spectroscopic applications, atmospheric lidar measurements require a tunable, narrow band laser with a very high degree of spectral purity. A standing wave pulsed alexandrite laser tuned by injection seeding with an AlGaAs laser diode has demonstrated high stability. The standing wave cavity, however, poses several difficulties in light of the single mode operation and efficient seeding beam into the cavity. In order to overcome these problems and to operate the high power alexandrite laser in a single axial mode with a high spectral purity, a new ring laser system is being developed. The design features of the ring laser and some measurements of the laser characteristics are presented.

  18. Existence and comparison results for fixed points of multifunctions with applications to normal-form games

    NASA Astrophysics Data System (ADS)

    Heikkila, S.

    2007-08-01

    In this paper we apply generalized iteration methods to prove comparison results which show how fixed points of a multifunction can be bounded by least and greatest fixed points of single-valued functions. As an application we prove existence and comparison results for fixed points of multifunctions. These results are applied to normal-form games, by proving existence and comparison results for pure and mixed Nash equilibria and their utilities.

  19. Splitting of the zero-bias conductance peak as smoking gun evidence for the existence of the Majorana mode in a superconductor-semiconductor nanowire

    NASA Astrophysics Data System (ADS)

    Das Sarma, S.; Sau, Jay D.; Stanescu, Tudor D.

    2012-12-01

    Recent observations of a zero-bias conductance peak in tunneling transport measurements in superconductor-semiconductor nanowire devices provide evidence for the predicted zero-energy Majorana modes, but not the conclusive proof of their existence. We establish that direct observation of a splitting of the zero-bias conductance peak can serve as the smoking gun evidence for the existence of the Majorana mode. We show that the splitting has an oscillatory dependence on the Zeeman field (chemical potential) at fixed chemical potential (Zeeman field). By contrast, when the density is constant rather than the chemical potential—the likely situation in the current experimental setups—the splitting oscillations are generically suppressed. Our theory predicts the conditions under which the splitting oscillations can serve as the smoking gun for the experimental confirmation of the elusive Majorana mode.

  20. [Failure mode and effect analysis: application in chemotherapy].

    PubMed

    Chuang, Ching-Hui; Chuang, Sheu-Wen

    2009-08-01

    Medical institutions are increasingly concerned about ensuring the safety of patients under their care. Failure mode and effect analysis (FMEA) is a qualitative approach based on a proactive process. Strongly promoted by the Joint Commission Accredited of Health Organization (JCAHO) since 2002, FMEA has since been adopted and widely practiced in healthcare organizations to assess and analyze clinical error events. FMEA has proven to be an effective method of minimizing errors in both manufacturing and healthcare industries. It predicts failure points in systems and allows an organization to address proactively the causes of problems and prioritize improvement strategies. The application of FMEA in chemotherapy at our department identified three main failure points: (1) inappropriate chemotherapy standard operating procedures (SOPs), (2) communication barriers, and (3) insufficient training of nurses. The application of FMEA in chemotherapy is expected to enhance the sensitivity and proactive abilities of healthcare practitioners during potentially risky situations as well as to improve levels of patient care safety. PMID:19634100

  1. 26 CFR 20.2045-1 - Applicability to pre-existing transfers or interests.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 14 2013-04-01 2013-04-01 false Applicability to pre-existing transfers or interests. 20.2045-1 Section 20.2045-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Gross...

  2. 26 CFR 20.2045-1 - Applicability to pre-existing transfers or interests.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 14 2010-04-01 2010-04-01 false Applicability to pre-existing transfers or interests. 20.2045-1 Section 20.2045-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Gross...

  3. 26 CFR 20.2045-1 - Applicability to pre-existing transfers or interests.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 14 2011-04-01 2010-04-01 true Applicability to pre-existing transfers or interests. 20.2045-1 Section 20.2045-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Gross...

  4. 26 CFR 20.2045-1 - Applicability to pre-existing transfers or interests.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 14 2012-04-01 2012-04-01 false Applicability to pre-existing transfers or interests. 20.2045-1 Section 20.2045-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Gross...

  5. 26 CFR 20.2045-1 - Applicability to pre-existing transfers or interests.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 14 2014-04-01 2013-04-01 true Applicability to pre-existing transfers or interests. 20.2045-1 Section 20.2045-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Gross...

  6. 24 CFR 888.111 - Fair market rents for existing housing: Applicability.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 4 2013-04-01 2013-04-01 false Fair market rents for existing housing: Applicability. 888.111 Section 888.111 Housing and Urban Development REGULATIONS RELATING TO... RENTS AND CONTRACT RENT ANNUAL ADJUSTMENT FACTORS Fair Market Rents § 888.111 Fair market rents...

  7. 40 CFR 63.1422 - Compliance dates and relationship of this rule to existing applicable rules.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 12 2013-07-01 2013-07-01 false Compliance dates and relationship of this rule to existing applicable rules. 63.1422 Section 63.1422 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES...

  8. 76 FR 22152 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-20

    ... modification filed by the parties listed below to modify the application of existing mandatory safety standards... address listed above. FOR FURTHER INFORMATION CONTACT: Barbara Barron, Office of Standards, Regulations... standard to permit the use of extended trailing cables on Mobile Bridge Conveyors, Dual Boom Roof...

  9. 27 CFR 41.232 - Application for permit or amendment of existing permit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2011-04-01 2011-04-01 false Application for permit or amendment of existing permit. 41.232 Section 41.232 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY (CONTINUED) TOBACCO IMPORTATION OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES,...

  10. 78 FR 3032 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-15

    ..., located in Le Flore County, Oklahoma. Regulation Affected: 30 CFR 75.1700 (Oil and gas wells... Safety and Health Administration Petitions for Modification of Application of Existing Mandatory Safety Standards AGENCY: Mine Safety and Health Administration, Labor. ACTION: Notice. SUMMARY: Section 101(c)...

  11. 23 CFR 633.203 - Applicability of existing laws, regulations, and directives.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Applicability of existing laws, regulations, and directives. 633.203 Section 633.203 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS REQUIRED CONTRACT PROVISIONS Federal-Aid Contracts (Appalachian...

  12. 23 CFR 633.203 - Applicability of existing laws, regulations, and directives.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 23 Highways 1 2014-04-01 2014-04-01 false Applicability of existing laws, regulations, and directives. 633.203 Section 633.203 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS REQUIRED CONTRACT PROVISIONS Federal-Aid Contracts (Appalachian...

  13. 23 CFR 633.203 - Applicability of existing laws, regulations, and directives.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 23 Highways 1 2011-04-01 2011-04-01 false Applicability of existing laws, regulations, and directives. 633.203 Section 633.203 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS REQUIRED CONTRACT PROVISIONS Federal-Aid Contracts (Appalachian...

  14. 23 CFR 633.203 - Applicability of existing laws, regulations, and directives.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 23 Highways 1 2012-04-01 2012-04-01 false Applicability of existing laws, regulations, and directives. 633.203 Section 633.203 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS REQUIRED CONTRACT PROVISIONS Federal-Aid Contracts (Appalachian...

  15. 23 CFR 633.203 - Applicability of existing laws, regulations, and directives.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 23 Highways 1 2013-04-01 2013-04-01 false Applicability of existing laws, regulations, and directives. 633.203 Section 633.203 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS REQUIRED CONTRACT PROVISIONS Federal-Aid Contracts (Appalachian...

  16. Flexible Modes Control Using Sliding Mode Observers: Application to Ares I

    NASA Technical Reports Server (NTRS)

    Shtessel, Yuri B.; Hall, Charles E.; Baev, Simon; Orr, Jeb S.

    2010-01-01

    The launch vehicle dynamics affected by bending and sloshing modes are considered. Attitude measurement data that are corrupted by flexible modes could yield instability of the vehicle dynamics. Flexible body and sloshing modes are reconstructed by sliding mode observers. The resultant estimates are used to remove the undesirable dynamics from the measurements, and the direct effects of sloshing and bending modes on the launch vehicle are compensated by means of a controller that is designed without taking the bending and sloshing modes into account. A linearized mathematical model of Ares I launch vehicle was derived based on FRACTAL, a linear model developed by NASA/MSFC. The compensated vehicle dynamics with a simple PID controller were studied for the launch vehicle model that included two bending modes, two slosh modes and actuator dynamics. A simulation study demonstrated stable and accurate performance of the flight control system with the augmented simple PID controller without the use of traditional linear bending filters.

  17. Application of Geiger-mode photosensors in Cherenkov detectors

    NASA Astrophysics Data System (ADS)

    Gamal, Ahmed; Paul, Bühler; Michael, Cargnelli; Roland, Hohler; Johann, Marton; Herbert, Orth; Ken, Suzuki

    2011-05-01

    Silicon-based photosensors (SiPMs) working in the Geiger-mode represent an elegant solution for the readout of particle detectors working at low-light levels like Cherenkov detectors. Especially the insensitivity to magnetic fields makes this kind of sensors suitable for modern detector systems in subatomic physics which are usually employing magnets for momentum resolution. We are characterizing SiPMs of different manufacturers for selecting sensors and finding optimum operating conditions for given applications. Recently we designed and built a light concentrator prototype with 8×8 cells to increase the active photon detection area of an 8×8 SiPM (Hamamatsu MPPC S10931-100P) array. Monte Carlo studies, measurements of the collection efficiency, and tests with the MPPC were carried out. The status of these developments are presented.

  18. Applicability study on existing dosimetry systems to high-power Bremsstrahlung irradiation

    NASA Astrophysics Data System (ADS)

    Mehta, Kishor; Kojima, Takuji; Sunaga, Hiromi

    2003-12-01

    Applicability of the existing dosimetry systems to high-power Bremsstrahlung irradiation was investigated through a dose intercomparison study, where several dosimeters were irradiated in the dose range 4-12 kGy in identical polyethylene phantoms in a Bremsstrahlung beam obtained from a 5-MeV electron accelerator. Included in the study were alanine dosimeters molded by three different binders, three types of liquid dosimeters—ceric-cerous, dichromate and ethanol-chlorobenzen (ECB), and glutamine powder. The dosimeter responses for Bremsstrahlung radiation were analyzed at the issuing laboratories, and the dose values determined using calibration based on cobalt-60 gamma-ray irradiation. Dose values for all the three dose levels for all dosimetry systems were in good agreement—better than 3%. The results of the study demonstrate that these existing dosimetry systems have a potential for application to high-power Bremsstrahlung irradiation.

  19. Strategy Guideline: Application of a Construction Quality Process to Existing Home Retrofits

    SciTech Connect

    Mallay, D.; Del Bianco, M.

    2013-08-01

    The Home Innovation Research Labs developed a construction quality process for new and existing high performance homes (HPH) in which high performance goals are established, specifications to meet those goals are defined, and construction monitoring points are added to the construction schedule so that critical energy efficiency details are systematically reviewed, documented, and tested in a timely manner. This report follows the evolution of the construction quality process from its development for new homes, to its application in the construction of a high performance home with enhanced specifications, and its application in a crawlspace renovation.

  20. Strategy Guideline. Application of a Construction Quality Process to Existing Home Retrofits

    SciTech Connect

    Mallay, D.; Del Bianco, M.

    2013-08-01

    The Partnership for Home Innovation developed a construction quality process for new and existing high performance homes (HPH) in which high performance goals are established, specifications to meet those goals are defined, and construction monitoring points are added to the construction schedule so that critical energy efficiency details are systematically reviewed, documented, and tested in a timely manner. This report follows the evolution of the construction quality process from its development for new homes, to its application in the construction of a high performance home with enhanced specifications, and its application in a crawlspace renovation.

  1. MHD-model for low-frequency waves in a tokamak with toroidal plasma rotation and problem of existence of global geodesic acoustic modes

    NASA Astrophysics Data System (ADS)

    Lakhin, V. P.; Sorokina, E. A.; Ilgisonis, V. I.; Konovaltseva, L. V.

    2015-12-01

    A set of reduced linear equations for the description of low-frequency perturbations in toroidally rotating plasma in axisymmetric tokamak is derived in the framework of ideal magnetohydrodynamics. The model suitable for the study of global geodesic acoustic modes (GGAMs) is designed. An example of the use of the developed model for derivation of the integral conditions for GGAM existence and of the corresponding dispersion relation is presented. The paper is dedicated to the memory of academician V.D. Shafranov.

  2. MHD-model for low-frequency waves in a tokamak with toroidal plasma rotation and problem of existence of global geodesic acoustic modes

    SciTech Connect

    Lakhin, V. P.; Sorokina, E. A. E-mail: vilkiae@gmail.com; Ilgisonis, V. I.; Konovaltseva, L. V.

    2015-12-15

    A set of reduced linear equations for the description of low-frequency perturbations in toroidally rotating plasma in axisymmetric tokamak is derived in the framework of ideal magnetohydrodynamics. The model suitable for the study of global geodesic acoustic modes (GGAMs) is designed. An example of the use of the developed model for derivation of the integral conditions for GGAM existence and of the corresponding dispersion relation is presented. The paper is dedicated to the memory of academician V.D. Shafranov.

  3. Feasibility study of the application of existing techniques to remotely monitor hydrochloric acid in the atmosphere

    NASA Technical Reports Server (NTRS)

    Zwick, H.; Ward, V.; Beaudette, L.

    1973-01-01

    A critical evaluation of existing optical remote sensors for HCl vapor detection in solid propellant rocket plumes is presented. The P branch of the fundamental vibration-rotation band was selected as the most promising spectral feature to sense. A computation of transmittance for HCl vapor, an estimation of interferent spectra, the application of these spectra to computer modelled remote sensors, and a trade-off study for instrument recommendation are also included.

  4. Applications of interference theory to single failure modes

    SciTech Connect

    Rauth, D.R.; Lusardi, D.J.

    1988-12-31

    REL02 is a computer code which provides a designer and analyst with a mathematical tool to calculate the expected failure probability under a variety of assumptions of the form of two overlapping probability distributions. This code has extended the solutions of closed-form calculations to the applications involving truncated normal and Weibull distribution as well as the uniform distribution. These distributions have been found to describe the variations which exist in (a) analytical predictions of stress parameters and (b) accumulated test results of strength data. REL02 has been written to calculate the general failure probability based on the interaction of a specified applied stress distribution and a known failure strength distribution. This program has been useful to quantitatively evaluate the adequacy of design margins and the acceptability of discrepant fabrication conditions. Examples of the application of this code to engineering problems are presented.

  5. Existence and continuity of bi-spatial random attractors and application to stochastic semilinear Laplacian equations

    NASA Astrophysics Data System (ADS)

    Li, Yangrong; Gu, Anhui; Li, Jia

    2015-01-01

    A concept of a bi-spatial random attractor for a random dynamical system is introduced. A unified result about existence and upper semi-continuity for a family of bi-spatial random attractors is obtained if a family of random systems is convergent, uniformly absorbing in an initial space and uniformly omega-compact in both initial and terminate spaces. The upper semi-continuity result improves all existing results even for single-spatial attractors. As an application of the abstract result, it is shown that every semilinear Laplacian equation on the entire space perturbed by a multiplicative and stochastic noise possesses an (L2, Lq)-random attractor with q > 2. Moreover, it is proved that the family of obtained attractors is upper semi-continuous at any density of noises and the family of attractors for the corresponding compact systems is both upper and lower semi-continuous at infinity under the topology of both spaces.

  6. Comparative assessment of thematic accuracy of GLC maps for specific applications using existing reference data

    NASA Astrophysics Data System (ADS)

    Tsendbazar, N. E.; de Bruin, S.; Mora, B.; Schouten, L.; Herold, M.

    2016-02-01

    Inputs to various applications and models, current global land cover (GLC) maps are based on different data sources and methods. Therefore, comparing GLC maps is challenging. Statistical comparison of GLC maps is further complicated by the lack of a reference dataset that is suitable for validating multiple maps. This study utilizes the existing Globcover-2005 reference dataset to compare thematic accuracies of three GLC maps for the year 2005 (Globcover, LC-CCI and MODIS). We translated and reinterpreted the LCCS (land cover classification system) classifier information of the reference dataset into the different map legends. The three maps were evaluated for a variety of applications, i.e., general circulation models, dynamic global vegetation models, agriculture assessments, carbon estimation and biodiversity assessments, using weighted accuracy assessment. Based on the impact of land cover confusions on the overall weighted accuracy of the GLC maps, we identified map improvement priorities. Overall accuracies were 70.8 ± 1.4%, 71.4 ± 1.3%, and 61.3 ± 1.5% for LC-CCI, MODIS, and Globcover, respectively. Weighted accuracy assessments produced increased overall accuracies (80-93%) since not all class confusion errors are important for specific applications. As a common denominator for all applications, the classes mixed trees, shrubs, grasses, and cropland were identified as improvement priorities. The results demonstrate the necessity of accounting for dissimilarities in the importance of map classification errors for different user application. To determine the fitness of use of GLC maps, accuracy of GLC maps should be assessed per application; there is no single-figure accuracy estimate expressing map fitness for all purposes.

  7. Whispering gallery mode resonators for frequency metrology applications

    NASA Astrophysics Data System (ADS)

    Baumgartel, Lukas

    This dissertation describes an investigation into the use of whispering gallery mode (WGM) resonators for applications towards frequency reference and metrology. Laser stabilization and the measurement of optical frequencies have enabled myriad technologies of both academic and commercial interest. A technology which seems to span both motivations is optical atomic clocks. These devices are virtually unimaginable without the ultra stable lasers plus frequency measurement and down-conversion afforded by Fabry Perot (FP) cavities and model-locked laser combs, respectively. However, WGM resonators can potentially perform both of these tasks while having the distinct advantages of compactness and simplicity. This work represents progress towards understanding and mitigating the performance limitations of WGM cavities for such applications. A system for laser frequency stabilization to a the cavity via the Pound-Drever-Hall (PDH) method is described. While the laser lock itself is found to perform at the level of several parts in 1015, a variety of fundamental and technical mechanisms destabilize the WGM frequency itself. Owing to the relatively large thermal expansion coefficients in optical crystals, environmental temperature drifts set the stability limit at time scales greater than the thermal relaxation time of the crystal. Uncompensated, these drifts pull WGM frequencies about 3 orders of magnitude more than they would in an FP cavity. Thus, two temperature compensation schemes are developed. An active scheme measures and stabilizes the mode volume temperature to the level of several nK, reducing the effective temperature coefficient of the resonator to 1.7x10-7 K-1; simulations suggest that the value could eventually be as low as 3.5x10-8 K-1, on par with the aforementioned FP cavities. A second, passive scheme is also described, which employs a heterogeneous resonator structure that capitalizes on the thermo-mechanical properties of one material and the optical

  8. Detrending with Empirical Mode Decomposition (DEMD): Theory, Evaluation, and Application

    NASA Astrophysics Data System (ADS)

    Bolch, Michael Adam

    measurements from ˜18 m s -1 to ˜55 m s-1 over a stable marine boundary layer (MBL). Another set of observations studies HOP and tower data, using the Duke University Mobile Micrometeorological Station (MMS) over an MBL, and concludes that HOP sensible heat (SH), latent heat (LE), and carbon dioxide (F CO2) fluxes align well with MMS findings. The HOP sensors provide ABL data at 40 Hz, as well as a real-time display of theta for in-flight ABL height estimation. Sensor calibration and alignment procedures indicate usable ABL measurements. HOP data are especially susceptible to the spurious influence of platform motion on ABL data, largely due to the low-altitude and low-airspeed capabilities of the HOP. For example, HOP altitude motion in the presence of a lapse rate can cause spurious T fluctuations. Empirical mode decomposition (EMD) can separate HOP data into a set of adaptive and unique intrinsic mode functions (IMFs), often with physical meaning. DEMD aims to correct for spurious contributions to HOP data, while merging EMD with a correlation analysis to adjust data without eliminating relevant ABL dynamics. To evaluate DEMD efficacy, two-dimensional synthetic T fields with simulated turbulence over a prescribed lapse rate are sampled with altitude fluctuations similar to HOP flights, and with a wide range of T perturbation and sampling path parameter variations. DEMD recovers the prescribed lapse rate within 1% on average for the 552 test cases passing the filtering criteria. The method is further evaluated via application to vertical cross sections taken from the Ocean-Land-Atmosphere Model (OLAM) large-eddy simulation (LES) results, where DEMD shows improved accuracy of SH recovery. DEMD is applied to three low-altitude HOP flight legs flown on 19 June 2007 during the Cloud and Land Surface Interaction Campaign (CLASIC), both as an example of practical application and to compare DEMD to the initially proposed method (Holder et al. 2011, hereafter H11). H11 dictates

  9. Application of intrawell testing of RCRA groundwater monitoring data when no upgradient well exists.

    PubMed

    Chou, C J; O'Brien, R F; Barnett, D B

    2001-09-01

    A statistical quality control approach to detect changes in groundwater quality from a regulated waste unit is described. The approach applies the combined Shewhart-CUSUM control chart methodology for intrawell comparison of analyte concentrations over time and does not require an upgradient well. A case study from the U.S. Department of Energy's Hanford Site is used for illustration purposes. This method is broadly applicable in groundwater monitoring programs where there is no clearly defined upgradient location, the groundwater flow rate is exceptionally slow, or where a high degree of spatial variability exists in parameter concentrations. This study also indicates that the use of the Data Quality Objectives (DQO) process can assist in designing an efficient and cost-effective groundwater monitoring plan to achieve the optimum goal of both low false positive and low false negative rates (high power). PMID:11589498

  10. An Architecture for Standardized Terminology Services by Wrapping and Integration of Existing Applications

    PubMed Central

    Cornet, Ronald; Prins, Antoon K.

    2003-01-01

    Research on terminology services has resulted in development of applications and definition of standards, but has not yet led to widespread use of (standardized) terminology services in practice. Current terminology services offer functionality both for concept representation and lexical knowledge representation, hampering the possibility of combining the strengths of dedicated (concept and lexical) services. We therefore propose an extensible architecture in which concept-related and lexicon-related components are integrated and made available through a uniform interface. This interface can be extended in order to conform to existing standards, making it possible to use dedicated (third-party) components in a standardized way. As a proof of concept and a reference implementation, a SOAP-based Java implementation of the terminology service is being developed, providing wrappers for Protégé and UMLS Knowledge Source Server. Other systems, such as the Description Logic-based reasoner RACER can be easily integrated by implementation of an appropriate wrapper. PMID:14728158

  11. Berreman mode and epsilon near zero mode.

    PubMed

    Vassant, Simon; Hugonin, Jean-Paul; Marquier, Francois; Greffet, Jean-Jacques

    2012-10-01

    In this paper, we discuss the existence of an electromagnetic mode propagating in a thin dielectric film deposited on a metallic film at the particular frequency such that the dielectric permittivity vanishes. We discuss the remarkable properties of this mode in terms of extreme subwavelength mode confinment and its potential applications. We also discuss the link between this mode, the IR absorption peak on a thin dielectric film known as Berreman effect and the surface phonon polariton mode at the air/dielectric interface. Finally, we establish a connection with the polarization shift occuring in quantum wells. PMID:23188363

  12. Applicability of the Existing CVD Risk Assessment Tools to Type II Diabetics in Oman: A Review

    PubMed Central

    Al-Rawahi, Abdulhakeem; Lee, Patricia

    2015-01-01

    Patients with type II diabetes (T2DM) have an elevated risk for cardiovascular disease (CVD), and it is considered to be a leading cause of morbidity and premature mortality in these patients. Many traditional risk factors such as age, male sex, hypertension, dyslipidemia, glycemic control, diabetes duration, renal dysfunction, obesity, and smoking have been studied and identified as independent factors for CVD. Quantifying the risk of CVD among diabetics using the common risk factors in order to plan the treatment and preventive measures is important in the management of these patients as recommended by many clinical guidelines. Therefore, several risk assessment tools have been developed in different parts of the world for this purpose. These include the tools that have been developed for general populations and considered T2DM as a risk factor, and the tools that have been developed for T2DM populations specifically. However, due to the differences in sociodemographic factors and lifestyle patterns, as well as the differences in the distribution of various CVD risk factors in different diabetic populations, the external applicability of these tools on different populations is questionable. This review aims to address the applicability of the existing CVD risk models to the Omani diabetic population. PMID:26421110

  13. Application of the Index of Biotic Integrity to existing TVA data

    SciTech Connect

    Saylor, C.; Scott, E.M. Jr.

    1987-09-01

    The Index of Biotic Integrity (IBI) is a recently developed method of evaluating environmental quality at a given stream site by measuring certain aspects of the resident fish population (Karr, 1981). Application of IBI in different geographical regions, and to various perturbations of water quality and habitat has been shown by Fausch et al. (1984), Karr et al. (1986), and Leonard and Orth (1986). IBI was used by O'Bara (in press) to assess the effects of coal mine runoff on certain second order streams in the Cumberland River Drainage. IBI continues to undergo testing and modification; however, its value as a monitoring tool is apparent, and it may very well become a standard method for various TVA projects. To evaluate the use of IBI on streams of the Tennessee Valley, this report examines application of the method to existing TVA fish data that were gathered to complete Activity 2 of the Cumberlandian Mussel Conservation Program (CMCP) (TVA, 1986). 9 refs., 1 fig., 8 tabs.

  14. Few-mode fiber based sensor in biomedical application

    NASA Astrophysics Data System (ADS)

    Zhang, Jing

    2015-05-01

    A novel few-mode fiber based sensor for monitoring the vital signs of pulse (heart rate), and breathing rate (respiratory rate) was developed. The sensor was applied in non-invasive measurement of pulse and breathing rates. The pulse, breathing and even body movement affected the sensor's output as the strain on the few-mode fiber changed with these activities. This sensor has simple structure and easy to fabricate. Its signal is easy to monitor. It can be used in the medical equipment in what situation non-invasive realtime monitoring and measurement of pulse rate, and respiratory/body movement pattern of healthy subjects are required.

  15. Application of partial sliding mode in guidance problem.

    PubMed

    Shafiei, M H; Binazadeh, T

    2013-03-01

    In this paper, the problem of 3-dimensional guidance law design is considered and a new guidance law based on partial sliding mode technique is presented. The approach is based on the classification of the state variables within the guidance system dynamics with respect to their required stabilization properties. In the proposed law by using a partial sliding mode technique, only trajectories of a part of states variables are forced to reach the partial sliding surfaces and slide on them. The resulting guidance law enables the missile to intercept highly maneuvering targets within a finite interception time. Effectiveness of the proposed guidance law is demonstrated through analysis and simulations. PMID:23260528

  16. Polarization conversion by hybrid modes: Theory and applications

    NASA Astrophysics Data System (ADS)

    Mertens, K.; Sennewald, M.; Schmitt, H. J.

    1996-11-01

    In strip-loaded slab waveguides, mode coupling between the transverse magnetic (TM11) and the transverse electric (TE21) modes can occur even if isotropic materials such as InP or GaAs are used. This coupling leads to new eigenmodes with a strong hybrid character, that is, the strength of the transverse side components is in the range of the main components. We show that the effect can be explained by a perturbation analysis investigating a raised strip waveguide, which is thought as a superposition of a buried strip waveguide and a dielectric perturbation in the region of the substrate. The described mode-coupling effect should be taken into account when designing integrated optic components, where strip and strip-loaded slab waveguides are commonly used. On the other hand, the hybrid modes can be used to develop new TE/TM converters. We present a new device based on InP which converts an input TE polarization into a mixture of TE and TM polarization, making it an interesting candidate for coherent receiver chips.

  17. Possible confirmation of the existence of the ergoregion by the Kerr quasinormal mode in gravitational waves from a Population III massive black hole binary

    NASA Astrophysics Data System (ADS)

    Kinugawa, Tomoya; Nakano, Hiroyuki; Nakamura, Takashi

    2016-03-01

    The existence of the ergoregion of the Kerr space-time has not yet been confirmed observationally. We show that the confirmation would be possible by observing the quasinormal mode in gravitational waves. As an example, using the recent population synthesis results of Population III (Pop III) binary black holes, we find that the peak of the final merger mass (M_f) is about 50 M_{⊙}, while the fraction of the final spin q_f = a_f/M_f > 0.7 needed for the confirmation of a part of the ergoregion is {˜ }77%. To confirm the frequency of the quasinormal mode, SNR > 35 is needed. The standard model of Pop III population synthesis tells us that the event rate for the confirmation of more than 50% of the ergoregion by second generation gravitational wave detectors is {˜ }2.3 events yr^{-1 (SFR_p/(10^{-2.5} M_⊙ yr^{-1} Mpc^{-3}))} \\cdot ([f_b/(1+f_b)]/0.33), where SFR_p and f_b are the peak value of the Pop III star formation rate and the fraction of binaries, respectively.

  18. Testing existing software for safety-related applications. Revision 7.1

    SciTech Connect

    Scott, J.A.; Lawrence, J.D.

    1995-12-01

    The increasing use of commercial off-the-shelf (COTS) software products in digital safety-critical applications is raising concerns about the safety, reliability, and quality of these products. One of the factors involved in addressing these concerns is product testing. A tester`s knowledge of the software product will vary, depending on the information available from the product vendor. In some cases, complete source listings, program structures, and other information from the software development may be available. In other cases, only the complete hardware/software package may exist, with the tester having no knowledge of the internal structure of the software. The type of testing that can be used will depend on the information available to the tester. This report describes six different types of testing, which differ in the information used to create the tests, the results that may be obtained, and the limitations of the test types. An Annex contains background information on types of faults encountered in testing, and a Glossary of pertinent terms is also included. This study is pertinent for safety-related software at reactors.

  19. Models for 31-mode PVDF energy harvester for wearable applications.

    PubMed

    Zhao, Jingjing; You, Zheng

    2014-01-01

    Currently, wearable electronics are increasingly widely used, leading to an increasing need of portable power supply. As a clean and renewable power source, piezoelectric energy harvester can transfer mechanical energy into electric energy directly, and the energy harvester based on polyvinylidene difluoride (PVDF) operating in 31-mode is appropriate to harvest energy from human motion. This paper established a series of theoretical models to predict the performance of 31-mode PVDF energy harvester. Among them, the energy storage one can predict the collected energy accurately during the operation of the harvester. Based on theoretical study and experiments investigation, two approaches to improve the energy harvesting performance have been found. Furthermore, experiment results demonstrate the high accuracies of the models, which are better than 95%. PMID:25114981

  20. Models for 31-Mode PVDF Energy Harvester for Wearable Applications

    PubMed Central

    Zhao, Jingjing; You, Zheng

    2014-01-01

    Currently, wearable electronics are increasingly widely used, leading to an increasing need of portable power supply. As a clean and renewable power source, piezoelectric energy harvester can transfer mechanical energy into electric energy directly, and the energy harvester based on polyvinylidene difluoride (PVDF) operating in 31-mode is appropriate to harvest energy from human motion. This paper established a series of theoretical models to predict the performance of 31-mode PVDF energy harvester. Among them, the energy storage one can predict the collected energy accurately during the operation of the harvester. Based on theoretical study and experiments investigation, two approaches to improve the energy harvesting performance have been found. Furthermore, experiment results demonstrate the high accuracies of the models, which are better than 95%. PMID:25114981

  1. Longitudinal modes along thin piezoelectric waveguides for liquid sensing applications.

    PubMed

    Caliendo, Cinzia

    2015-01-01

    The propagation of longitudinally polarized acoustic modes along thin piezoelectric plates (BN, ZnO, InN, AlN and GaN) is theoretically studied, aiming at the design of high frequency electroacoustic devices suitable for work in liquid environments. The investigation of the acoustic field profile across the plate revealed the presence of longitudinally polarized Lamb modes, travelling at velocities close to that of the longitudinal bulk acoustic wave propagating in the same direction. Such waves are suitable for the implementation of high-frequency, low-loss electroacoustic devices operating in liquid environments. The time-averaged power flow density, the phase velocity and the electroacoustic coupling coefficient K2 dispersion curves were studied, for the first (S0) and four higher order (S1, S2, S3, S4) symmetrical modes for different electrical boundary conditions. Two electroacoustic coupling configurations were investigated, based on interdigitated transducers, with or without a metal floating electrode at the opposite plate surface. Enhanced performances, such as a K2 as high as 8.5% and a phase velocity as high as 16,700 m/s, were demostrated for the ZnO- and BN-based waveguides, as an example. The relative velocity changes, and the inertial and viscous sensitivities of the first symmetric and anti-symmetric mode, S0 and A0, propagating along thin plates bordered by a viscous liquid were derived using the perturbation approach. The present study highlights the feasibility of the piezoelectric waveguides to the development of high-frequency, integrated-circuits compatible electroacoustic devices suitable for working in liquid environment. PMID:26043174

  2. Longitudinal Modes along Thin Piezoelectric Waveguides for Liquid Sensing Applications

    PubMed Central

    Caliendo, Cinzia

    2015-01-01

    The propagation of longitudinally polarized acoustic modes along thin piezoelectric plates (BN, ZnO, InN, AlN and GaN) is theoretically studied, aiming at the design of high frequency electroacoustic devices suitable for work in liquid environments. The investigation of the acoustic field profile across the plate revealed the presence of longitudinally polarized Lamb modes, travelling at velocities close to that of the longitudinal bulk acoustic wave propagating in the same direction. Such waves are suitable for the implementation of high-frequency, low-loss electroacoustic devices operating in liquid environments. The time-averaged power flow density, the phase velocity and the electroacoustic coupling coefficient K2 dispersion curves were studied, for the first (S0) and four higher order (S1, S2, S3, S4) symmetrical modes for different electrical boundary conditions. Two electroacoustic coupling configurations were investigated, based on interdigitated transducers, with or without a metal floating electrode at the opposite plate surface. Enhanced performances, such as a K2 as high as 8.5% and a phase velocity as high as 16,700 m/s, were demostrated for the ZnO- and BN-based waveguides, as an example. The relative velocity changes, and the inertial and viscous sensitivities of the first symmetric and anti-symmetric mode, S0 and A0, propagating along thin plates bordered by a viscous liquid were derived using the perturbation approach. The present study highlights the feasibility of the piezoelectric waveguides to the development of high-frequency, integrated-circuits compatible electroacoustic devices suitable for working in liquid environment. PMID:26043174

  3. Processing of complex shapes with single-mode resonant frequency microwave applicators

    SciTech Connect

    Fellows, L.A.; Delgado, R.; Hawley, M.C.

    1994-12-31

    Microwave processing is an alternative to conventional composite processing techniques. Single-mode microwave applicators efficiently couple microwave energy into the composite. The application of the microwave energy is greatly affected by the geometry of the composite. In the single mode microwave applicator, two types of modes are available. These modes are best suited to processing flat planar samples or cylindrical samples with geometries that align with the electric fields. Mode-switching is alternating between different electromagnetic modes with the intelligent selection of the modes to alleviate undesirable temperature profiles. This method has improved the microwave heating profiles of materials with complex shapes that do not align with either type of electric field. Parts with two different complex geometries were fabricated from a vinyl toluene/vinyl ester resin with a continuous glass fiber reinforcement by autoclaving and by microwave techniques. The flexural properties of the microwave processed samples were compared to the flexural properties of autoclaved samples. The trends of the mechanical properties for the complex shapes were consistent with the results of experiments with flat panels. This demonstrated that mode-switching techniques are as applicable for the complex shapes as they are for the simpler flat panel geometry.

  4. Comparison of mode estimation methods and application in molecular clock analysis

    NASA Technical Reports Server (NTRS)

    Hedges, S. Blair; Shah, Prachi

    2003-01-01

    BACKGROUND: Distributions of time estimates in molecular clock studies are sometimes skewed or contain outliers. In those cases, the mode is a better estimator of the overall time of divergence than the mean or median. However, different methods are available for estimating the mode. We compared these methods in simulations to determine their strengths and weaknesses and further assessed their performance when applied to real data sets from a molecular clock study. RESULTS: We found that the half-range mode and robust parametric mode methods have a lower bias than other mode methods under a diversity of conditions. However, the half-range mode suffers from a relatively high variance and the robust parametric mode is more susceptible to bias by outliers. We determined that bootstrapping reduces the variance of both mode estimators. Application of the different methods to real data sets yielded results that were concordant with the simulations. CONCLUSION: Because the half-range mode is a simple and fast method, and produced less bias overall in our simulations, we recommend the bootstrapped version of it as a general-purpose mode estimator and suggest a bootstrap method for obtaining the standard error and 95% confidence interval of the mode.

  5. Advanced high pressure engine study for mixed-mode vehicle applications

    NASA Technical Reports Server (NTRS)

    Luscher, W. P.; Mellish, J. A.

    1977-01-01

    High pressure liquid rocket engine design, performance, weight, envelope, and operational characteristics were evaluated for a variety of candidate engines for use in mixed-mode, single-stage-to-orbit applications. Propellant property and performance data were obtained for candidate Mode 1 fuels which included: RP-1, RJ-5, hydrazine, monomethyl-hydrazine, and methane. The common oxidizer was liquid oxygen. Oxygen, the candidate Mode 1 fuels, and hydrogen were evaluated as thrust chamber coolants. Oxygen, methane, and hydrogen were found to be the most viable cooling candidates. Water, lithium, and sodium-potassium were also evaluated as auxiliary coolant systems. Water proved to be the best of these, but the system was heavier than those systems which cooled with the engine propellants. Engine weight and envelope parametric data were established for candidate Mode 1, Mode 2, and dual-fuel engines. Delivered engine performance data were also calculated for all candidate Mode 1 and dual-fuel engines.

  6. Identification of standing MHD modes in MHD simulations of planetary magnetospheres. Application to Mercury.

    NASA Astrophysics Data System (ADS)

    Griton, Léa; Pantellini, Filippo; Moncuquet, Michel

    2016-04-01

    We present 3D simulations of the interaction of the solar wind with Mercury's magnetosphere using the magnetohydrodynamic code AMRVAC. A procedure for the identification of standing MHD modes has been applied to these simulations showing that large scale standing slow mode structures may exist in Mercury's magnetosheath. The identification is mostly based on relatively simple approximate analytical solutions to the old problem of determining the family of all standing linear plane MHD waves in a flowing plasma. The question of the identification of standing slow mode structures using in situ measurements such as the future BepiColombo MMO mission to Mercury will be discussed as well.

  7. Failure mode and effects analysis application to critical care medicine.

    PubMed

    Duwe, Beau; Fuchs, Barry D; Hansen-Flaschen, John

    2005-01-01

    In July 2001, the United States Joint Commission on Accreditation of Health care Organizations adopted a new leadership standard that requires department heads in health care organizations to perform at least one Failure Mode and Effects Analysis (FMEA) every year. This proactive approach to error prevention has proven to be highly effective in other industries, notably aerospace, but remains untested in acute care hospitals. For several reasons, the intensive care unit (ICU) potentially is an attractive setting for early adoption of FMEA; however, successful implementation of FMEA in ICUs is likely to require strong, effective leadership and a sustained commitment to prevent errors that may have occurred rarely or never before in the local setting. This article describes FMEA in relation to critical care medicine and reviews some of the attractive features together with several potential pitfalls that are associated with this approach to error prevention in ICUs. PMID:15579350

  8. Transmission Phase Holography: Spatial-Mode Filter Design for Quantum Information Applications

    NASA Astrophysics Data System (ADS)

    Hillmer, Rachel; Barreiro, Julio; Kwiat, Paul

    2007-03-01

    Photon spatial modes offer access to promising new applications in quantum information because they provide a higher-dimensional basis set than the usual two-dimensional one associated with polarization. Downconversion experiments have demonstrated spatial-mode entanglement [1], and even hyperentanglement in polarization and spatial mode [2]. However optical elements currently lack the refinement necessary to perform efficient, high-fidelity operations using spatial modes. Holographic filters for Laguerre-Gaussian and Hermite-Gaussian laser modes can act as modes converters, and have long been studied (under the terms ``modans'' and ``kinoforms'') for use in electrical engineering applications [3,4]. Her we present analytical refinements and optimizations of these techniques, with predicted mode fidelities over 95% and diffraction efficiencies up to 98%. Results of our experimental implementions of these solutions are presented. [1] Walborn, S.P, et al, ``Entanglement and conservation of orbital angular momentum in spontaneous parametric down-conversion,'' Phys. Rev. A 69, 023811 (2004); [2] Barreiro, J.T. et al, ``Generation of Hyperentangled Photon Pairs,'' Phys. Rev. Lett. 95, 260501 (2005); [3] Soifer, V.A., ``Methods of Computer Design of Diffractive Optical Elements,'' John Wiley & Sons, Inc., 2002; [4] Golub, M. and Soifer, V., ``Laser Beam Mode Selection by Computer Generated Holograms,'' CRC Press, Inc., 1994.

  9. Alternative Modes of Evaluation and Their Application to Rural Development.

    ERIC Educational Resources Information Center

    Wetherill, G. Richard; Buttram, Joan L.

    In order to "cut through the jargon of the multifaceted field of evaluative research", 21 evaluation models representing a range of possibilities were identified (via literature review) and compared in terms of purpose and five basic phases applicable to rural development. Evaluation was defined as "the systematic examination of a program in…

  10. An investigation of accelerating mode and decelerating mode constant-momentum mass spectrometry and their application to a residual gas analyzer

    NASA Technical Reports Server (NTRS)

    Ng, Y. S.

    1977-01-01

    A theoretical analysis of constant momentum mass spectrometry was made. A maximum resolving power for the decelerating mode constant momentum mass spectrometer was shown theoretically to exist for a beam of ions of known energy. A vacuum system and an electron beam ionization source was constructed. Supporting electronics for a residual gas analyzer were built. Experimental investigations of various types of accelerating and decelerating impulsive modes of a constant momentum mass spectrometer as applied to a residual gas analyzer were made. The data indicate that the resolving power for the decelerating mode is comparable to that of the accelerating mode.

  11. Sliding mode control of magnetic suspensions for precision pointing and tracking applications

    NASA Technical Reports Server (NTRS)

    Misovec, Kathleen M.; Flynn, Frederick J.; Johnson, Bruce G.; Hedrick, J. Karl

    1991-01-01

    A recently developed nonlinear control method, sliding mode control, is examined as a means of advancing the achievable performance of space-based precision pointing and tracking systems that use nonlinear magnetic actuators. Analytic results indicate that sliding mode control improves performance compared to linear control approaches. In order to realize these performance improvements, precise knowledge of the plant is required. Additionally, the interaction of an estimating scheme and the sliding mode controller has not been fully examined in the literature. Estimation schemes were designed for use with this sliding mode controller that do not seriously degrade system performance. The authors designed and built a laboratory testbed to determine the feasibility of utilizing sliding mode control in these types of applications. Using this testbed, experimental verification of the authors' analyses is ongoing.

  12. INSTRUMENTS AND METHODS OF INVESTIGATION: Cladding modes of optical fibers: properties and applications

    NASA Astrophysics Data System (ADS)

    Ivanov, Oleg V.; Nikitov, Sergei A.; Gulyaev, Yurii V.

    2006-02-01

    One of the new methods of fiber optics uses cladding modes for controlling propagation of radiation in optical fibers. This paper reviews the results of studies on the propagation, excitation, and interaction of cladding modes in optical fibers. The resonance between core and cladding modes excited by means of fiber Bragg gratings, including tilted ones, is analyzed. Propagation of cladding modes in microstructured fibers is considered. The most frequently used method of exciting cladding modes is described, based on the application of long-period fiber gratings. Examples are presented of long-period gratings used as sensors and gain equalizers for fiber amplifiers, as well as devices for coupling light into and out of optical fibers.

  13. 78 FR 59066 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-25

    ... 75.1101-1(b) (Deluge-type water spray systems). Modification Request: The petitioner requests a modification of the existing standard to eliminate the use of blow-off dust covers for the spray nozzles of a deluge-type water spray system. In support of the alternative method, the petitioner proposes to...

  14. Some properties and applications of biphoton states of three-mode light

    SciTech Connect

    Gorbachev, V. N.; Kulik, S. P. Trubilko, A. I.

    2008-09-15

    Statistical properties, generation, and applications of three-mode biphoton fields with no more than one photon in each mode are discussed. Such field states have sub-Poissonian photon statistics and can be squeezed and entangled. The modes that simultaneously exhibit these properties in measurements are indicated. Two setups for generating such states via spontaneous parametric down-conversion are described. It is shown that the field states discussed in this study provide a quantum channel for teleportation, dense coding, and quantum key distribution.

  15. Applications of the Zero-Group-Velocity Lamb Mode for Air-Coupled Ultrasonic Imaging

    NASA Astrophysics Data System (ADS)

    Holland, Stephen D.; Song, Jun-Ho; Evan, Victoria L.; Chimenti, D. E.

    2005-04-01

    Airborne ultrasound couples particularly well into plates at the zero-group-velocity point of the first order symmetric (S1) Lamb mode. Applications of this mode to ultrasonic imaging of plate-like structures are discussed. The sensitivity and high Q of this mode makes it ideal for imaging. Images from a wide variety of materials and samples, including composites and honeycomb structures are presented. Transmission at the zero-group-velocity frequency is shown to be particularly sensitive to nearby flaws and discontinuities, and is therefore suitable for wide-area scanning for cracks or manufacturing flaws.

  16. Enhanced modes excitation in photonic crystal fiber by long-period gratings for sensing application

    NASA Astrophysics Data System (ADS)

    Zheng, Shijie; Zhu, Yinian

    2016-03-01

    Evanescent-wave sensing platform is proposed by two interrogating schemes, core-cladding coupling and core-cladding-core coupling and re-coupling, in endlessly single-mode photonic crystal fiber (ESM-PCF) with long-period gratings (LPGs). The sensing characteristics are experimentally investigated by stress relaxation technique and point-by-point grating inscription via CO2 laser. It shows that the evanescent wave in cladding mode is significantly increased due to LPGs, compared with in core mode only. The introduced concept will further help explore the PCF evanescent-wave sensing and its applications.

  17. The S-ordered Operator Expansions of One-mode and Two-mode Fresnel Operators and their Applications

    NASA Astrophysics Data System (ADS)

    Du, Jian-ming; Ren, Gang; Yu, Hai-jun; Zhang, Wen-hai

    2016-08-01

    By using the technique of integration within the s-ordered product of operators (IWSOP), we first deduce the s-ordered expansion of the one-mode and two-mode Fresnel operators. Employing the s-ordered operator expansion formula, the matrix elements of one-mode and two-mode Fresnel operator in the number state representation are also obtained, respectively.

  18. 77 FR 37926 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-25

    ... the Federal Mine Safety and Health Act of 1977 and 30 CFR Part 44 govern the application, processing...; signal analyzer devices; ultrasonic thickness gauges; electronic component testers; and electronic...); voltage, current, and power measurement devices; signal analyzer devices; ultrasonic thickness...

  19. 40 CFR 60.5245 - When must I submit a title V permit application for my existing SSI unit?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false When must I submit a title V permit application for my existing SSI unit? 60.5245 Section 60.5245 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Emission Guidelines and Compliance Times...

  20. Comparative Application of Capacity Models for Seismic Vulnerability Evaluation of Existing RC Structures

    SciTech Connect

    Faella, C.; Lima, C.; Martinelli, E.; Nigro, E.

    2008-07-08

    Seismic vulnerability assessment of existing buildings is one of the most common tasks in which Structural Engineers are currently engaged. Since, its is often a preliminary step to approach the issue of how to retrofit non-seismic designed and detailed structures, it plays a key role in the successful choice of the most suitable strengthening technique. In this framework, the basic information for both seismic assessment and retrofitting is related to the formulation of capacity models for structural members. Plenty of proposals, often contradictory under the quantitative standpoint, are currently available within the technical and scientific literature for defining the structural capacity in terms of force and displacements, possibly with reference to different parameters representing the seismic response. The present paper shortly reviews some of the models for capacity of RC members and compare them with reference to two case studies assumed as representative of a wide class of existing buildings.

  1. Existing and new applications of micropellet injection (MPI) in magnetic fusion

    NASA Astrophysics Data System (ADS)

    Wang, Zhehui; Lunsford, Robert; Mansfield, Dennis K.; Nichols, Jacob H.

    2016-02-01

    > The intense heat and energetic particle fluxes expected in ITER and future magnetic fusion reactors pose prohibitive problems to the design, selection and maintenance of the first wall and divertor. Micropellet injection (MPI) technologies can offer some innovative solutions to the material and extreme heat challenges. Basic physics of micropellet motion, ablation and interactions with high-temperature plasmas and energetic particles are presented first. We then discuss MPI technology options and applications. In addition to plasma diagnostic applications, controlled injection of micropellets of different sizes, velocities and injection frequencies will offer several possibilities: (1) better assessment of the core plasma cooling due to dust produced in situ; (2) better understanding of the plasma-material interaction physics near the wall; (3) new methods for plasma fuelling and impurity control; and (4) techniques for edge cooling with minimal impact on the plasma core. Dedicated small-scale laboratory experiments will complement major fusion experiments in development and applications of MPI.

  2. Existing and new applications of micropellet injection (MPI) in magnetic fusion

    NASA Astrophysics Data System (ADS)

    Wang, Zhehui; Lunsford, Robert; Mansfield, Dennis K.; Nichols, Jacob H.

    2016-04-01

    > The intense heat and energetic particle fluxes expected in ITER and future magnetic fusion reactors pose prohibitive problems to the design, selection and maintenance of the first wall and divertor. Micropellet injection (MPI) technologies can offer some innovative solutions to the material and extreme heat challenges. Basic physics of micropellet motion, ablation and interactions with high-temperature plasmas and energetic particles are presented first. We then discuss MPI technology options and applications. In addition to plasma diagnostic applications, controlled injection of micropellets of different sizes, velocities and injection frequencies will offer several possibilities: (1) better assessment of the core plasma cooling due to dust produced in situ; (2) better understanding of the plasma-material interaction physics near the wall; (3) new methods for plasma fuelling and impurity control; and (4) techniques for edge cooling with minimal impact on the plasma core. Dedicated small-scale laboratory experiments will complement major fusion experiments in development and applications of MPI.

  3. 76 FR 59742 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-27

    ... the Federal Mine Safety and Health Act of 1977 and 30 CFR part 44 govern the application, processing....351. (3) Actions taken in response to the AMS malfunction and alert or alarm signal will be in... of activation of any AMS alert or alarm signal. This training will be conducted prior to...

  4. 40 CFR 63.1422 - Compliance dates and relationship of this rule to existing applicable rules.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) Table 1 of this subpart specifies the requirements in 40 CFR part 63, subpart A (the General Provisions... subpart. For the purposes of this subpart, Table 3 of 40 CFR part 63, subpart F is not applicable. (g) Table 2 of this subpart summarizes the provisions of 40 CFR part 63, subparts F, G, and H...

  5. 40 CFR 125.61 - Existence of and compliance with applicable water quality standards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... applicable water quality standards. 125.61 Section 125.61 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS CRITERIA AND STANDARDS FOR THE NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM Criteria for Modifying the Secondary Treatment Requirements Under Section 301(h) of the...

  6. 40 CFR 125.61 - Existence of and compliance with applicable water quality standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... applicable water quality standards. 125.61 Section 125.61 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS CRITERIA AND STANDARDS FOR THE NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM Criteria for Modifying the Secondary Treatment Requirements Under Section 301(h) of the...

  7. 40 CFR 125.61 - Existence of and compliance with applicable water quality standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... provisions of State law including water quality standards. This determination shall include a discussion of... applicable water quality standards. 125.61 Section 125.61 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS CRITERIA AND STANDARDS FOR THE NATIONAL POLLUTANT DISCHARGE...

  8. 40 CFR 125.61 - Existence of and compliance with applicable water quality standards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... provisions of State law including water quality standards. This determination shall include a discussion of... applicable water quality standards. 125.61 Section 125.61 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS CRITERIA AND STANDARDS FOR THE NATIONAL POLLUTANT DISCHARGE...

  9. 40 CFR 125.61 - Existence of and compliance with applicable water quality standards.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... provisions of State law including water quality standards. This determination shall include a discussion of... applicable water quality standards. 125.61 Section 125.61 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS CRITERIA AND STANDARDS FOR THE NATIONAL POLLUTANT DISCHARGE...

  10. 40 CFR 63.1422 - Compliance dates and relationship of this rule to existing applicable rules.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Table 1 of this subpart specifies the requirements in 40 CFR part 63, subpart A (the General Provisions... subpart. For the purposes of this subpart, Table 3 of 40 CFR part 63, subpart F is not applicable. (g) Table 2 of this subpart summarizes the provisions of 40 CFR part 63, subparts F, G, and H...

  11. 40 CFR 63.1422 - Compliance dates and relationship of this rule to existing applicable rules.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (e.g., 40 CFR part 63, subpart JJJ or U). (2) After the applicable compliance date specified in this... first learned of the problem. (f) Table 1 of this subpart specifies the requirements in 40 CFR part 63... affected sources subject to this subpart. For the purposes of this subpart, Table 3 of 40 CFR part...

  12. Existing drugs and their application in drug discovery targeting cancer stem cells.

    PubMed

    Lv, Junfang; Shim, Joong Sup

    2015-09-01

    Despite standard cancer therapies such as chemotherapy and targeted therapy have shown some efficacies, the cancer in many cases eventually relapses and metastasizes upon stopping the treatment. There is a small subpopulation of cancer cells within tumor, with specific characters similar to those found in stem cells. This group of cancer cells is known as tumor-initiating or cancer stem cells (CSCs), which have an ability to self-renew and give rise to cancer cell progeny. CSCs are related with drug resistance, metastasis and relapse of cancer, hence emerging as a crucial drug target for eliminating cancer. Rapid advancement of CSC biology has enabled researchers to isolate and culture CSCs in vitro, making the cells amenable to high-throughput drug screening. Recently, drug repositioning, which utilizes existing drugs to develop potential new indications, has been gaining popularity as an alternative approach for the drug discovery. As existing drugs have favorable bioavailability and safety profiles, drug repositioning is now actively exploited for prompt development of therapeutics for many serious diseases, such as cancer. In this review, we will introduce latest examples of attempted drug repositioning targeting CSCs and discuss potential use of the repositioned drugs for cancer therapy. PMID:26152874

  13. Edge instability regimes with applications to blob transport and the quasicoherent mode

    SciTech Connect

    Myra, J.R.; D'Ippolito, D.A.

    2005-09-15

    An analytic theory of the resistive X-point (RX) mode in the edge region of a diverted tokamak is developed by employing an outgoing-evanescent wave boundary condition along the field lines. This result is employed to deduce a new categorization of edge instabilities in the presence of X points. A regime diagram shows the relationship of the RX mode to the ideal and conventional resistive ballooning modes. In addition to describing growth rates of linear instabilities, the analysis also yields regimes and scalings for nonlinear convective ''blob'' propagation velocities. The regime diagram and a knowledge of experimental and BOUT code simulation results suggest that the quasicoherent mode seen in the Alcator C-Mod tokamak [M. Greenwald, R. Boivin, P. Bonoli et al., [Phys. Plasmas 6, 1943 (1999)] can be classified as an electromagnetic RX mode. Analytical scalings for the existence of this mode compare well with experimental trends, as does the solution of a model radial eigenvalue problem. Finally, using a finite Larmor radius assumption to eliminate the perpendicular wave number, the instability regime diagram can be converted to an edge phase space diagram. X-point physics adds a new region to this edge parameter space that is postulated to be the enhanced D-alpha regime.

  14. Failure modes and effects criticality analysis and accelerated life testing of LEDs for medical applications

    NASA Astrophysics Data System (ADS)

    Sawant, M.; Christou, A.

    2012-12-01

    While use of LEDs in Fiber Optics and lighting applications is common, their use in medical diagnostic applications is not very extensive. Since the precise value of light intensity will be used to interpret patient results, understanding failure modes [1-4] is very important. We used the Failure Modes and Effects Criticality Analysis (FMECA) tool to identify the critical failure modes of the LEDs. FMECA involves identification of various failure modes, their effects on the system (LED optical output in this context), their frequency of occurrence, severity and the criticality of the failure modes. The competing failure modes/mechanisms were degradation of: active layer (where electron-hole recombination occurs to emit light), electrodes (provides electrical contact to the semiconductor chip), Indium Tin Oxide (ITO) surface layer (used to improve current spreading and light extraction), plastic encapsulation (protective polymer layer) and packaging failures (bond wires, heat sink separation). A FMECA table is constructed and the criticality is calculated by estimating the failure effect probability (β), failure mode ratio (α), failure rate (λ) and the operating time. Once the critical failure modes were identified, the next steps were generation of prior time to failure distribution and comparing with our accelerated life test data. To generate the prior distributions, data and results from previous investigations were utilized [5-33] where reliability test results of similar LEDs were reported. From the graphs or tabular data, we extracted the time required for the optical power output to reach 80% of its initial value. This is our failure criterion for the medical diagnostic application. Analysis of published data for different LED materials (AlGaInP, GaN, AlGaAs), the Semiconductor Structures (DH, MQW) and the mode of testing (DC, Pulsed) was carried out. The data was categorized according to the materials system and LED structure such as AlGaInP-DH-DC, Al

  15. A new approach for integration of telemedicine applications into existing information systems in healthcare.

    PubMed

    Tobman, Matvei; Nätscher, Catharina; Sussmann, Helmut; Horsch, Alexander

    2002-01-01

    In order to take the full advantage of telemedicine applications, they must seamlessly be integrated into healthcare services and their information systems (e.g. HIS, POS, RIS). In our approach an HL7/XML-based integration module is used 1) to exchange documents with information systems; 2) to generate and administer documents internally; 3) to present documents. The module fills in pre-defined CDA-conforming XML templates with data from HL7 V2 messages. The approach is first applied to the teleconsultation service EST in the project ENDOTEL. PMID:15460679

  16. Moisture characteristics of water-repellent consolidants and their applicability to existing buildings

    NASA Astrophysics Data System (ADS)

    Iba, Chiemi; Fukui, Kazuma; Hokoi, Shuichi

    2016-07-01

    Water-repellent agents are considered an effective measure of preventing moisture damage in building materials. However, data on the moisture transfer characteristics of repellent materials are insufficient. This study focused on the transfer of liquid water in a porous building material and quantitatively evaluated the applicability of a water-repellent consolidant as a protection agent via water infiltration experiments and numerical analysis. The experimental results could be reproduced by treating the water-repellent consolidant as having two layers with different water conductivities.

  17. Multi-Wavelength Mode-Locked Laser Arrays for WDM Applications

    NASA Technical Reports Server (NTRS)

    Davis, L.; Young, M.; Dougherty, D.; Keo, S.; Muller, R.; Maker, P.

    1998-01-01

    Multi-wavelength arrays of colliding pulse mode-locked (CPM) lasers have been demonstrated for wavelength division multiplexing (WDM) applications. The need for increased bandwidth is driving the development of both increased speed in time division multiplexing (TDM) and more channels in WDM for fiber optic communication systems.

  18. Planar air-bearing microgravity simulators: Review of applications, existing solutions and design parameters

    NASA Astrophysics Data System (ADS)

    Rybus, Tomasz; Seweryn, Karol

    2016-03-01

    All devices designed to be used in space must be thoroughly tested in relevant conditions. For several classes of devices the reduced gravity conditions are the key factor. In early stages of development and later due to financial reasons, the tests need to be done on Earth. However, in Earth conditions it is impossible to obtain a different gravity field independent on all linear and rotational spatial coordinates. Therefore, various test-bed systems are used, with their design driven by the device's specific needs. One of such test-beds are planar air-bearing microgravity simulators. In such an approach, the tested objects (e.g., manipulators intended for on-orbit operations or vehicles simulating satellites in a close formation flight) are mounted on planar air-bearings that allow almost frictionless motion on a flat surface, thus simulating microgravity conditions in two dimensions. In this paper we present a comprehensive review of research activities related to planar air-bearing microgravity simulators, demonstrating achievements of the most active research groups and describing newest trends and ideas, such as tests of landing gears for low-g bodies. Major design parameters of air-bearing test-beds are also reviewed and a list of notable existing test-beds is presented.

  19. Error localization using mode shapes: An application to a two link robot arm

    SciTech Connect

    Mayes, R.

    1991-01-01

    A technique to localize errors between two modal models is presented. Mode shape difference are calculated from each model. A global comparison of the ratios of these corresponding differences is used to identify the physical locations on the structure where stiffness differences exist between the two models. Some of the strengths and limitations of the technique are illustrated using the mode shapes of two similar finite element models with a known stiffness difference. The technique is then applied to a two link robot arm for which a finite element model exists and a modal test has been conducted. The results of the error localization aid the selection of physical parameters to be updated in the finite element model. Sensitivity methods are used to correlate the finite element model to the modal test. The results of the correlation are presented. 5 refs., 3 figs., 3 tabs.

  20. Fit for purpose application of currently existing animal models in the discovery of novel epilepsy therapies.

    PubMed

    Löscher, Wolfgang

    2016-10-01

    Animal seizure and epilepsy models continue to play an important role in the early discovery of new therapies for the symptomatic treatment of epilepsy. Since 1937, with the discovery of phenytoin, almost all anti-seizure drugs (ASDs) have been identified by their effects in animal models, and millions of patients world-wide have benefited from the successful translation of animal data into the clinic. However, several unmet clinical needs remain, including resistance to ASDs in about 30% of patients with epilepsy, adverse effects of ASDs that can reduce quality of life, and the lack of treatments that can prevent development of epilepsy in patients at risk following brain injury. The aim of this review is to critically discuss the translational value of currently used animal models of seizures and epilepsy, particularly what animal models can tell us about epilepsy therapies in patients and which limitations exist. Principles of translational medicine will be used for this discussion. An essential requirement for translational medicine to improve success in drug development is the availability of animal models with high predictive validity for a therapeutic drug response. For this requirement, the model, by definition, does not need to be a perfect replication of the clinical condition, but it is important that the validation provided for a given model is fit for purpose. The present review should guide researchers in both academia and industry what can and cannot be expected from animal models in preclinical development of epilepsy therapies, which models are best suited for which purpose, and for which aspects suitable models are as yet not available. Overall further development is needed to improve and validate animal models for the diverse areas in epilepsy research where suitable fit for purpose models are urgently needed in the search for more effective treatments. PMID:27505294

  1. Applicability of mode-based damage assessment methods to severely damaged steel building

    NASA Astrophysics Data System (ADS)

    HoThu, Hien; Mita, Akira

    2012-04-01

    After a large earthquake, the evaluation of damage of structures is an important task for structural health assessment. Therefore, the structural health monitoring (SHM) has become major researches which focus in the area of structural dynamics. As we known, the presence of damage or deterioration in a structure can be detected by the changes in the natural frequencies of the structure. Furthermore mode shape changes can be categorized as damage localization1. Besides, many damage detection algorithms based on the modal properties of structure such as modal frequencies, mode shapes, curvature mode shapes and modal flexibilities have been studied for several decades. However, in most algorithms, identifying the precise location and magnitude of the damage is difficult. If not completely impossible, the accuracy and reliability is not sufficient2. Using only modal frequencies and their mode shapes changes to qualify damage seems very difficult to get the real damage in many previous studies. This research desires to test the applicability of mode-based damage assessment method to the real-size building, in order to give correlation between simulation models and real building with the changes in frequencies and mode shapes. The data of the simulations and E-defense Tests on the full-scale four-story steel building will be used to test this exiting method.

  2. Optimal orientations of LiTaO3 for application in plate mode resonators

    NASA Astrophysics Data System (ADS)

    Naumenko, Natalya F.

    2015-07-01

    Optimal cuts of LiTaO3 for application in plate mode resonators were found via rigorous numerical investigations of zero- and higher-order plate modes propagating parallel or normal to the X-axis in rotated Y-cuts of LiTaO3; the plates were tested with a periodic metal grating on top of the plate and metal electrode present or absent on the plate bottom. In some cuts, high electromechanical coupling coefficients up to 20% could be combined with low or even zero temperature coefficients of frequency (TCF). Other cuts ensured moderate coupling of 12%-14% and low TCF in addition to high velocity of a higher-order plate mode up to 20 000 m/s. Metallization of a plate bottom helped to enhance coupling of certain modes. Interaction of a plate mode with electrodes of an interdigital transducer or with periodic metal gratings used for its excitation and reflection in resonators is illustrated by examples of dispersion plots. The nature of the analyzed modes was studied via visualization of the mechanical displacements accompanying wave propagation.

  3. Instantaneous mode contamination and parametric combination instability of spinning cyclically symmetric ring structures with expanding application to planetary gear ring

    NASA Astrophysics Data System (ADS)

    Wang, Shiyu; Sun, Wenjia; Wang, Yaoyao

    2016-08-01

    This work addresses the free and parametric elastic vibrations of the spinning cyclically symmetric ring structures. The focus is on the instantaneous mode contamination, parametric combination instability and their connections. An analytical model is developed by using the Hamilton's principle for the in-plane bending deflection, the distinction of which is in the arbitrary distributions of the attached mass and stiffness. A special case with equally-spaced discrete mass particles and spinning springs is detailed. The uneven tangential force and the time-invariant deflection caused by the mass particles are formulated. The results imply that the order of such deflection is equal to the number of the mass particles. The instantaneous mode contamination and parametric combination instability are captured by the perturbation and superposition mode shapes of the stationary smooth ring by introducing complex coefficients. The contamination rule is similar to that of the stationary structure but the contamination strength is time-variant due to the spinning springs. New analytical results and quantitative explanations on the contamination and instability especially their connections are presented. As an application of the proposed method, the free and parametric vibrations of the planetary gear ring are formulated. Main results are demonstrated by means of the numerical simulations and compared with the existing studies.

  4. A Review and Analysis of Existing Mobile Phone Applications for HAI Prevention

    PubMed Central

    Schnall, Rebecca; Iribarren, Sarah

    2015-01-01

    Background The expanding number of mobile health applications (apps) holds tremendous potential to reduce and eliminate healthcare associated infections (HAIs) in clinical practice. The purpose of this review was to identify and provide an overview of the apps available to support prevention of HAIs and to assess their functionality and potential uses in clinical care. Methods We searched three online mobile app stores using the following terms: infection prevention, prevention, hand hygiene, hand washing, and specific HAI terms (catheter-associated urinary tract infection (CAUTI), central line-associated bloodstream infections (CLABSI), surgical site infection, and ventilator associated pneumonia (VAP)). Results Search queries yielded a total of 2,646 potentially relevant apps, of which 17 met our final inclusion criteria. The areas of focus were: CAUTI (n=1, 5.9%), VAP (n=1, 5.9%), environmental monitoring (n=2, 11.8%), hand hygiene (n=2, 11.8%), and the remainder (n=11, 64.7%) were focused on more than one area (e.g., multiple infection prevention bundles or infection prevention guidelines). Conclusion Mobile apps may help reduce HAI by providing easy access to guidelines, hand hygiene monitoring support, or step-by-step procedures aimed at reducing infections at the point of clinical care. Given the dearth of available apps, and the lack of functionality with those that are available, there is a need for further development of mobile apps for HAI prevention at the point of care. PMID:25748924

  5. Smartphone applications for communicating avalanche risk information - a review of existing practices

    NASA Astrophysics Data System (ADS)

    Charrière, M. K. M.; Bogaard, T. A.

    2015-11-01

    Every year, in all mountainous regions, people are victims of avalanches. One way to decrease those losses is believed to be informing about danger levels. The paper presents a study on current practices in the development of smartphones applications that are dedicated to avalanche risk communication. The analysis based on semi-structured interviews with developers of smartphone apps highlights the context of their development, how choices of content and visualization were made as well as how their effectiveness is evaluated. It appears that although the communicators agree on the message to disseminate, its representation triggers debate. Moreover, only simple evaluation processes are conducted but there is a clear awareness that further scientific efforts are needed to analyze the effectiveness of the smartphone apps. Finally, the current or planned possibility for non-experts users to report feedback on the snow and avalanches conditions open the doors to a transition of these apps from one-way communication tools to two-ways communication platforms. This paper also indicates the remaining challenges that avalanche risk communication is facing, although it is disputably the most advanced and standardized practice compared to other natural hazards. Therefore, this research is of interest for the entire field of natural hazards related risk communication.

  6. Progressive phase conjugation and its application in reconfigurable spatial-mode extraction and conversion

    NASA Astrophysics Data System (ADS)

    Okamoto, Atsushi; Maeda, Tomohiro; Hirasaki, Yuki; Tomita, Akihisa; Sato, Kunihiro

    2014-05-01

    We develop a new technology, which is referred to as progressive phase conjugation (PPC), in which phase conjugation is electrically performed without requiring a coherent reference beam by fusion using a reference-free spatial phase detection and spatial phase modulation. This method enables remote setting of a phase detector from the signal transmitter without an additional transmission line for the reference beam. It also enables realization of high-speed and dynamic wavefront compensation owing to its open-loop architecture using the single-shot phase detection method. Therefore, the PPC is applicable to a wide range of optical communication technologies, including the reconfigurable spatial-mode extraction and conversion of mode transmission in a multi-mode fiber (MMF). In our experiment, spatial modes are generated by directing a laser beam into a MMF with a 50-micron core diameter. At the output side of the optical fiber, the phase distributions of the spatial modes are detected using the reference-free phase detector constructed by combining a spatial filtering method with holographic diversity interferometry using two CCD imagers. Then, the phase conjugate distribution of the detected phase pattern is displayed on a LCOS-type SLM. We confirm that the PPC system can extract a specific mode pattern with a considerably low crosstalk of less than 1% by displaying the corresponding phase-conjugation pattern on the SLM. In addition, we demonstrated a reconfigurable spatial-mode conversion by the phase control technology using the SLM. By applying the spatial phase modulation to an optical beam incident on the SLM, the spatial mode of the output beam is flexibly changed.

  7. Polarisation effects in twin-core fibre: Application for mode locking in a fibre laser

    SciTech Connect

    Lobach, I A; Kablukov, S I; Podivilov, Evgenii V; Babin, Sergei A; Apolonski, A A

    2012-09-30

    We report the first measurements of the longitudinal power distribution in a twin-core optical fibre at different input light polarisations. Experimental evidence is presented that, because of the difference in birefringence between the cores, the power in them depends on which core the beam is launched into. Experimental data are interpreted in terms of a modified polarisation model for mode coupling in twin-core fibres which takes into account the birefringence of the cores. In addition, we demonstrate for the first time the use of the polarisation properties of a twincore fibre for mode locking in a fibre laser. (optical fibres, lasers and amplifiers. properties and applications)

  8. Compact Si photonic multimode interference-based optical circuit for mode division multiplexing applications

    NASA Astrophysics Data System (ADS)

    El-Sabban, Salwa; Khalil, Diaa

    2016-07-01

    A design for a compact Si photonic two mode demultiplexer for mode division multiplexing (MDM) applications is presented. The design uses the self-imaging in multimode interference structures to achieve MDM with an insertion loss less than 0.5 dB and a cross talk better than 20 dB over the C band. The imaging is achieved within a length that is half the length reported in the literature, and its overall dimensions are 42 μm×3 μm. The minimum cross talk is affected by the structure geometry. The tolerance of the design to variations in the dimensions is also studied.

  9. Using Pre-existing Microarray Datasets to Increase Experimental Power: Application to Insulin Resistance

    PubMed Central

    Daigle, Bernie J.; Deng, Alicia; McLaughlin, Tracey; Cushman, Samuel W.; Cam, Margaret C.; Reaven, Gerald; Tsao, Philip S.; Altman, Russ B.

    2010-01-01

    software package that is immediately applicable to any human microarray study. PMID:20361040

  10. Application of Sliding Mode Methods to the Design of Reconfigurable Flight Control Systems

    NASA Technical Reports Server (NTRS)

    Wells, Scott R.

    2002-01-01

    Observer-based sliding mode control is investigated for application to aircraft reconfigurable flight control. A comprehensive overview of reconfigurable flight control is given, including, a review of the current state-of-the-art within the subdisciplines of fault detection, parameter identification, adaptive control schemes, and dynamic control allocation. Of the adaptive control methods reviewed, sliding mode control (SMC) appears very promising due its property of invariance to matched uncertainty. An overview of sliding mode control is given and its remarkable properties are demonstrated by example. Sliding mode methods, however, are difficult to implement because unmodeled parasitic dynamics cause immediate and severe instability. This presents a challenge for all practical applications with limited bandwidth actuators. One method to deal with parasitic dynamics is the use of an asymptotic observer in the feedback path. Observer-based SMC is investigated, and a method for selecting observer gains is offered. An additional method for shaping the feedback loop using a filter is also developed. It is shown that this SMC prefilter is equivalent to a form of model reference hedging. A complete design procedure is given which takes advantage of the sliding mode boundary layer to recast the SMC as a linear control law. Frequency domain loop shaping is then used to design the sliding manifold. Finally, three aircraft applications are demonstrated. An F-18/HARV is used to demonstrate a SISO pitch rate tracking controller. It is also used to demonstrate a MIMO lateral-directional roll rate tracking controller. The last application is a full linear six degree-of-freedom advanced tailless fighter model. The observer-based SMC is seen to provide excellent tracking with superior robustness to parameter changes and actuator failures.

  11. Nonwork and off-peak trips by transit, walk and bicycle modes: An understanding of existing and potential markets. Final report, 1 August 1996--28 February 1998

    SciTech Connect

    Soeoet, S.; Sen, A.; Yang, D.; Dirks, L.; Sternberg, T.

    1999-03-01

    The study identifies the characteristics of neighborhoods that contribute to off-peak transit, walk or bike use. The emphasis is on off-peak and nonwork trips and how to promote modes other than the automobile. By producing thirty maps illustrating socioeconomic and travel behavior patterns in the Chicago area, the potential for stabilizing and then increasing the utilization of these modes is examined. Substantial amounts of data were processed and reported. For example, off-peak trips, accounting for 48% of daily travel, are shorter than trips during the peak (in miles and minutes) for travel by both public transit and by private vehicle. Regionally, walking trips vary from 42% of all trips made by Chicago CBD residents (mainly to shop and work), 17% in the rest of the city and less than 5% in suburban Chicago. Bicycle ownership is related to the number of vehicles in the household, household income, household size and distance from the Chicago CBD. These data and field observations of three case-study neighborhoods revealed that differences in modes used are related to the land-use patterns and the socioeconomic characteristics of the resident population. While areas with low automobile ownership rates might suggest walking and bicycling, these nonmotorized modes are more common in affluent neighborhoods with a large number of nearby commercial and recreational destinations.

  12. Applicability and economic efficiency of earthquake retrofit measures on existing buildings in Bucharest, Romania

    NASA Astrophysics Data System (ADS)

    Bostenaru, M.

    2009-04-01

    The research discussed in this contribution contains two aspects: on one side the economic efficiency of seismic retrofit measures, and on the other their applicability. The research was limited to housing buildings. Bucharest, the capital of Romania, was the object of the research. Strong earthquakes affect Bucharest about three times in a century, the damaging earthquakes of the 20th century being in 1940 and 1977. Other strong earthquakes occurred in 1986 and 1990. Since it is a broad topic, first the building type was determined, which should serve further research. For this scope the building types of the 20th century, which are common in Bucharest, Romania, were investigated. For each building type reports have been written, which comprised the earthquake resilient features, the seismic defficiencies, the damage patterns and the retrofit measures. Each of these features was listed for elements of the building. A first result of the research was an integrated system in order to include latter aspects in the planning in the first steps. So already at the building survey attention has to be paid on how a building is subdivided in order to be able to determine the economic efficiency of the planned action. So were defined the `retrofit elements`. In a first step the characteristics were defined, through which these retrofit elements (for example column, wall part between two windows) can be recognised in the building survey. In a further one, which retrofit measures can be connected to these. Diagrams were built, in order to visualise these findings. For each retrofit element and the corresponding measure the costs were calculated. Also, these retrofit elements and the measures connected to them were modelled for the simulation with the structural software, so that the benefit of the measures could be determined. In the part which regarded the economic efficiency, benefits and costs of retrofit measures had to be compared, so the improvement in the rigidity

  13. Fiber Bragg grating in large-mode-area fiber for high power fiber laser applications.

    PubMed

    Mohammed, Waleed; Gu, Xijia

    2010-10-01

    Fiber Bragg gratings (FBGs) are indispensable components in the design of monolithic high-power fiber lasers. As the laser power scales up, the adoption of larger-mode-area fibers with high V numbers poses new challenges for FBG design and fabrication. In this paper, we present the simulation, fabrication, and measurement of the FBGs inscribed on large-mode-area fibers. The simulation used the T-matrix approach to calculate the spectral response of the FBG that matched well with the measured spectra. The observed fringes in the reflection spectrum are explained by the interference between the low-order modes that were also confirmed with the simulation. Some unique features of the FBG and their potential applications are discussed. PMID:20885465

  14. Multimode and single-mode fibers for data center and high-performance computing applications

    NASA Astrophysics Data System (ADS)

    Bickham, Scott R.

    2016-03-01

    Data center (DC) and high performance computing (HPC) applications have traditionally used a combination of copper, multimode fiber and single-mode fiber interconnects with relative percentages that depend on factors such as the line rate, reach and connectivity costs. The balance between these transmission media has increasingly shifted towards optical fiber due to the reach constraints of copper at data rates of 10 Gb/s and higher. The percentage of single-mode fiber deployed in the DC has also grown slightly since 2014, coinciding with the emergence of mega DCs with extended distance needs beyond 100 m. This trend will likely continue in the next few years as DCs expand their capacity from 100G to 400G, increase the physical size of their facilities and begin to utilize silicon-photonics transceiver technology. However there is a still a need for the low-cost and high-density connectivity, and this is sustaining the deployment of multimode fiber for links <= 100 m. In this paper, we discuss options for single-mode and multimode fibers in DCs and HPCs and introduce a reduced diameter multimode fiber concept which provides intra-and inter-rack connectivity as well as compatibility with silicon-photonic transceivers operating at 1310 nm. We also discuss the trade-offs between single-mode fiber attributes such as bend-insensitivity, attenuation and mode field diameter and their roles in capacity and connectivity in data centers.

  15. Study of Rotating-Wave Electromagnetic Modes for Applications in Space Exploration

    NASA Astrophysics Data System (ADS)

    Velazco, J. E.

    2016-08-01

    Rotating waves are circularly polarized electromagnetic wave fields that behave like traveling waves but have discrete resonant frequencies of standing waves. In JPL's Communications Ground Systems Section (333), we are making use of this peculiar type of electromagnetic modes to develop a new generation of devices and instruments for direct applications in space exploration. In this article, we present a straightforward analysis about the phase velocity of these wave modes. A derivation is presented for the azimuthal phase velocity of transverse magnetic rotating modes inside cylindrical cavity resonators. Computer simulations and experimental measurements are also presented that corroborate the theory developed. It is shown that the phase velocity of rotating waves inside cavity resonators increases with radial position within the cavity and decreases when employing higher-order operating modes. The exotic features of rotating modes, once better understood, have the potential to enable the implementation of a plethora of new devices that range from amplifiers and frequency multipliers to electron accelerators and ion thrusters.

  16. Application and Evaluation of Control Modes for Risk-Based Engine Performance Enhancements

    NASA Technical Reports Server (NTRS)

    Liu, Yuan; Litt, Jonathan S.; Sowers, T. Shane; Owen, A. Karl (Compiler); Guo, Ten-Huei

    2014-01-01

    The engine control system for civil transport aircraft imposes operational limits on the propulsion system to ensure compliance with safety standards. However, during certain emergency situations, aircraft survivability may benefit from engine performance beyond its normal limits despite the increased risk of failure. Accordingly, control modes were developed to improve the maximum thrust output and responsiveness of a generic high-bypass turbofan engine. The algorithms were designed such that the enhanced performance would always constitute an elevation in failure risk to a consistent predefined likelihood. This paper presents an application of these risk-based control modes to a combined engine/aircraft model. Through computer and piloted simulation tests, the aim is to present a notional implementation of these modes, evaluate their effects on a generic airframe, and demonstrate their usefulness during emergency flight situations. Results show that minimal control effort is required to compensate for the changes in flight dynamics due to control mode activation. The benefits gained from enhanced engine performance for various runway incursion scenarios are investigated. Finally, the control modes are shown to protect against potential instabilities during propulsion-only flight where all aircraft control surfaces are inoperable.

  17. Application and Evaluation of Control Modes for Risk-Based Engine Performance Enhancements

    NASA Technical Reports Server (NTRS)

    Liu, Yuan; Litt, Jonathan S.; Sowers, T. Shane; Owen, A. Karl; Guo, Ten-Huei

    2015-01-01

    The engine control system for civil transport aircraft imposes operational limits on the propulsion system to ensure compliance with safety standards. However, during certain emergency situations, aircraft survivability may benefit from engine performance beyond its normal limits despite the increased risk of failure. Accordingly, control modes were developed to improve the maximum thrust output and responsiveness of a generic high-bypass turbofan engine. The algorithms were designed such that the enhanced performance would always constitute an elevation in failure risk to a consistent predefined likelihood. This paper presents an application of these risk-based control modes to a combined engine/aircraft model. Through computer and piloted simulation tests, the aim is to present a notional implementation of these modes, evaluate their effects on a generic airframe, and demonstrate their usefulness during emergency flight situations. Results show that minimal control effort is required to compensate for the changes in flight dynamics due to control mode activation. The benefits gained from enhanced engine performance for various runway incursion scenarios are investigated. Finally, the control modes are shown to protect against potential instabilities during propulsion-only flight where all aircraft control surfaces are inoperable.

  18. Nonlinear 6-fold enhancement of laser drilling efficiency by double pulse mode: prospective in medicine application

    NASA Astrophysics Data System (ADS)

    Pershina, N. S.; Pershin, S. M.; Cech, M.; Prochazka, I.

    2009-05-01

    The efficiency of laser ablation drilling of metal and dielectric (ceramic, glasses, etc.) samples with single and multiple laser pulses per one laser shot was experimentally studied. The laser is operated on the fundamental (1064 nm) wavelength of Nd:YAG laser with 30 ns pulse length or its second (532 nm) and third (351 nm) harmonics, respectively. The laser shot repletion rate was 1 Hz. The pulses in train were separated by 25-45 μs interval. The crater depth and drilling speed dependence increasing on pulse number in multipulse train was studied. The laser ablation normalized per pulse energy in train dependence is not linear function. The strong ablation enhancement was observed. The optimal (in sense the total pulse energy using) drilling can be obtained with double pulse mode compared with 3 - 5 pulses. Nonlinear more than 6 fold increasing of crater depth produced by the second pulse in train was detected. The mechanism of selective increasing of the second pulse interaction efficiency with the hard target is discussed. Experimental results explained in terms of double pulse mode laser ablation model. Spectroscopy study of laser plasma was observed to confirm discussed model of high efficiency for two laser pulse laser ablation. Efficiency of double pulse mode compared with multipulse mode is discussed to be more perspective for various applications of laser ablation. The medicine (surgery, dentist, ophthalmology and so on) application is the most prospective, for instance, the teeth drilling or glaucoma perforation, can be done with smaller energy value.

  19. Adapting an existing visualization application for browser-based deployment: A case study from the Tropical Rainfall Measuring Mission

    NASA Astrophysics Data System (ADS)

    Kelley, Owen A.

    2013-02-01

    THOR, the Tool for High-resolution Observation Review, is a data viewer for the Tropical Rainfall Measuring Mission (TRMM) and the upcoming Global Precipitation Measurement (GPM) mission. THOR began as a desktop application, but now it can be accessed with a web browser, making THOR one of the first online tools for visualizing TRMM satellite data (http://pps.gsfc.nasa.gov/thor). In this effort, the reuse of the existing visualization code was maximized and the complexity of new code was minimized by avoiding unnecessary functionality, frameworks, or libraries. The simplicity of this approach makes it potentially attractive to researchers wishing to adapt their visualization applications for online deployment. To enable THOR to run within a web browser, three new pieces of code are written. First, the graphical user interface (GUI) of the desktop application is translated into HTML, JavaScript, and CSS. Second, a simple communication mechanism is developed over HTTP. Third, a virtual GUI is created on the server that interfaces with the image-generating routines of the existing desktop application so that these routines do not need to be modified for online use. While the basic functionality of THOR is now available online, prototyping is ongoing for enhanced 3D imaging and other aspects of both THOR Desktop and THOR Online. Because TRMM data products are complex and periodically reprocessed with improved algorithms, having a tool such as THOR is important to analysts at the Precipitation Processing System where the algorithms are tested and the products generated, stored, and distributed. Researchers also have found THOR useful for taking a first look at individual files before writing their own software to perform specialized calculations and analyses.

  20. Two-dimensional complex source point solutions: application to propagationally invariant beams, optical fiber modes, planar waveguides, and plasmonic devices.

    PubMed

    Sheppard, Colin J R; Kou, Shan S; Lin, Jiao

    2014-12-01

    Highly convergent beam modes in two dimensions are considered based on rigorous solutions of the scalar wave (Helmholtz) equation, using the complex source point formalism. The modes are applicable to planar waveguide or surface plasmonic structures and nearly concentric microcavity resonator modes in two dimensions. A novel solution is that of a vortex beam, where the direction of propagation is in the plane of the vortex. The modes also can be used as a basis for the cross section of propagationally invariant beams in three dimensions and bow-tie-shaped optical fiber modes. PMID:25606756

  1. Sensitivity-based operational mode shape normalisation: Application to a bridge

    NASA Astrophysics Data System (ADS)

    Parloo, E.; Cauberghe, B.; Benedettini, F.; Alaggio, R.; Guillaume, P.

    2005-01-01

    Recently, an innovative sensitivity-based technique was introduced for the normalisation of operational mode shapes purely on a basis of output-only data. The technique is based on the use of a controlled mass modification experiment and does not involve any analytical models. Moreover, it allows to extend the applicability of many modal analysis based applications towards the domain of in-operation modal testing. Previously, this method was successfully tested by means of experiments on various mechanical engineering structures. The focus of this contribution is the validation of the sensitivity-based normalisation technique on a civil structure. For this purpose, measurements were performed on a bridge.

  2. Effect of application mode on interfacial morphology and chemistry between dentin and self-etch adhesives

    PubMed Central

    Zhang, Ying; Wang, Yong

    2012-01-01

    Objective To investigate the influence of application mode on the interfacial morphology and chemistry between dentin and self-etch adhesives with different aggressiveness. Methods The occlusal one-third of the crown was removed from un-erupted human third molars, followed by abrading with 600 grit SiC under water. Rectangular dentin slabs were prepared by sectioning the tooth specimens perpendicular to the abraded surfaces. The obtained dentin slabs were treated with one of the two one-step self-etch adhesives: Adper Easy Bond (AEB, PH~2.5) and Adper Prompt L-Pop (APLP, PH~0.8) with (15s, active application) or without (15s, inactive application) agitation. The dentin slabs were fractured and the exposed adhesive/dentin (A/D) interfaces were examined with micro-Raman spectroscopy and scanning electron microscopy (SEM). Results The interfacial morphology, degree of dentin demineralization (DD) and degree of conversion (DC) of the strong self-etch adhesive APLP showed more significant dependence on the application mode than the mild AEB. APLP exhibited inferior bonding at the A/D interface if applied without agitation, evidenced by debonding from the dentin substrate. The DDs and DCs of the APLP with agitation were higher than those of without agitation in the interface, in contrast to the comparable DD and DC values of two AEB specimen groups with different application modes. Raman spectral analysis revealed the important role of chemical interaction between acid monomers of self-etch adhesives and dentin in the above observations. Conclusion The chemical interaction with dentin is especially important for improving the DC of the strong self-etching adhesive at the A/D interface. Agitation could benefit polymerization efficacy of the strong self-etch adhesive through enhancing the chemical interaction with tooth substrate. PMID:23153573

  3. Overview and Applications of UAVSAR's Multi-Squint Polarimetric Imaging Mode

    NASA Technical Reports Server (NTRS)

    Scott Hensley; Chen, Curtis; Michel, Thierry; Jones, Cathleen; Chapman, Bruce; Muellerschoen, Ron

    2011-01-01

    NASA's Jet Propulsion Laboratory has developed a reconfigurable polarimetric L-band synthetic aperture radar (SAR), specifically designed to acquire airborne repeat track interferometric (RTI) SAR data for application to monitoring surface deformation and vegetation structure measurements. The system employs a precision autopilot developed by NASA Dryden that allows the plane to fly precise trajectories usually within a 5 m tube. Also required for robust repeat pass applications is the ability to point the antenna in the same direction on repeat passes to a fraction of an azimuth beamwidth (8? for UAVSAR). This precise pointing is achieved using an electronically scanned antenna whose pointing is based on inertial navigation unit (INU) attitude angle data. The radar design is fully polarimetric with an 80 MHz bandwidth (2 m range resolution) and has a greater than 20 km range swath when flying at its nominal altitude of 12500 m. The ability to electronically steer the beam on a pulse-to-pulse basis has allowed a new mode of SAR data acquisition whereby the radar beam is steered to different squint angles on successive pulses thereby simultaneously generating images at multiple squint angles. This mode offers the possibility of generating vector deformation measurements with a single pair of repeat passes and to obtain greater kz diversity for vegetation studies with a reduced number of passes. This paper will present an overview of the mode, discuss its potential for deformation and vegetation, and show some examples using UAVSAR data.

  4. Application of AirCell Cellular AMPS Network and Iridium Satellite System Dual Mode Service to Air Traffic Management

    NASA Technical Reports Server (NTRS)

    Shamma, Mohammed A.

    2004-01-01

    The AirCell/Iridium dual mode service is evaluated for potential applications to Air Traffic Management (ATM) communication needs. The AirCell system which is largely based on the Advanced Mobile Phone System (AMPS) technology, and the Iridium FDMA/TDMA system largely based on the Global System for Mobile Communications(GSM) technology, can both provide communication relief for existing or future aeronautical communication links. Both have a potential to serve as experimental platforms for future technologies via a cost effective approach. The two systems are well established in the entire CONUS and globally hence making it feasible to utilize in all regions, for all altitudes, and all classes of aircraft. Both systems have been certified for air usage. The paper summarizes the specifications of the AirCell/Iridium system, as well as the ATM current and future links, and application specifications. the paper highlights the scenarios, applications, and conditions under which the AirCell/Iridium technology can be suited for ATM Communication.

  5. Small Externally-fueled Heat Pipe Thermionic Reactor (SEHPTR) for dual mode applications

    NASA Astrophysics Data System (ADS)

    Malloy, John; Jacox, Michael; Zubrin, Robert

    1992-07-01

    The Small Externally Fueled Heat-Pipe Thermionic Reactor (SEHPTR) is described in the context of applications as a dual-mode nuclear power source for satellites. The SEHPTR is a thermionic power system based on a reactor with modular fuel elements around cylindrical thermionic heat-pipe modules with diodes for heat rejection. The SEHPTR concept is theorized to be suitable for directly heating hydrogen gas in the core to increase propulsion and reduce orbit-transfer times. The advantages of dual-mode operation of the SEHPTR are listed including enhanced mission safety and performance at relatively low costs. The SEHPTR could provide direct thermal thrust and an integrated stage that symbiotically utilizes electric power, direct thrust, and hydrogen arcjets. The system is argued to be more effective than a nuclear power system designed solely for electrical power production.

  6. The application of infrared synchrotron radiation to the study of interfacial vibrational modes

    SciTech Connect

    Hirschmugl, C.J.; Williams, G.P.

    1992-12-31

    Synchrotron radiation provides an extremely bright broad-band source in the infrared which is ideally suited to the study of surface and interface vibrational modes in the range 50--3,000 cm{sup {minus}1}. Thus it covers the important range of molecule-substrate interactions, as well as overlapping with the more easily accessible near-ir region where molecular internal modes are found. Compared to standard broadband infrared sources such as globars, not only is it 1,000 times brighter, but its emittance matches the phase-space of the electrochemical cell leading to full utilization of this brightness advantage. In addition, the source is more stable even than water-cooled globars in vacuum for both short-term and long-term fluctuations. The authors summarize the properties of synchrotron radiation in the infrared, in particular pointing out the distinct differences between this and the x-ray region. They use experimental data in discussing important issues of signal to noise and address the unique problems and advantages of the synchrotron source. Thus they emphasize the important considerations necessary for developing new facilities. This analysis then leads to a discussion of phase-space matching to electrochemical cells, and to other surfaces in vacuum. Finally they show several examples of the application of infrared synchrotron radiation to surface vibrational spectroscopy. The examples are for metal crystal surfaces in ultra-high vacuum and include CO/Cu(100) and (111) and CO/K/Cu(100). The experiments show how the stability of the synchrotron source allows subtle changes in the background to be observed in addition to the discrete vibrational modes. These changes are due to electronic states induced by the adsorbate. In some cases the authors have seen interferences between these and the discrete vibrational modes, leading to a breakdown of the dipole selection rules, and the observation of additional modes.

  7. The application of infrared synchrotron radiation to the study of interfacial vibrational modes

    SciTech Connect

    Hirschmugl, C.J.; Williams, G.P.

    1992-01-01

    Synchrotron radiation provides an extremely bright broad-band source in the infrared which is ideally suited to the study of surface and interface vibrational modes in the range 50--3,000 cm[sup [minus]1]. Thus it covers the important range of molecule-substrate interactions, as well as overlapping with the more easily accessible near-ir region where molecular internal modes are found. Compared to standard broadband infrared sources such as globars, not only is it 1,000 times brighter, but its emittance matches the phase-space of the electrochemical cell leading to full utilization of this brightness advantage. In addition, the source is more stable even than water-cooled globars in vacuum for both short-term and long-term fluctuations. The authors summarize the properties of synchrotron radiation in the infrared, in particular pointing out the distinct differences between this and the x-ray region. They use experimental data in discussing important issues of signal to noise and address the unique problems and advantages of the synchrotron source. Thus they emphasize the important considerations necessary for developing new facilities. This analysis then leads to a discussion of phase-space matching to electrochemical cells, and to other surfaces in vacuum. Finally they show several examples of the application of infrared synchrotron radiation to surface vibrational spectroscopy. The examples are for metal crystal surfaces in ultra-high vacuum and include CO/Cu(100) and (111) and CO/K/Cu(100). The experiments show how the stability of the synchrotron source allows subtle changes in the background to be observed in addition to the discrete vibrational modes. These changes are due to electronic states induced by the adsorbate. In some cases the authors have seen interferences between these and the discrete vibrational modes, leading to a breakdown of the dipole selection rules, and the observation of additional modes.

  8. Applications of a single-longitudinal-mode alexandrite laser for diagnostics of parameters of combustion interest

    NASA Astrophysics Data System (ADS)

    Li, Z. S.; Afzelius, M.; Zetterberg, J.; Aldén, M.

    2004-10-01

    We report on the applications of a single-longitudinal-mode (SLM) pulsed alexandrite laser system for diagnostics of parameters of flow/combustion interest. The laser system is characterized by its narrow linewidth, high peak power, and broad tunablity. The absolute frequency of the laser output was monitored by a wavelength diagnostic system, which included a high-resolution confocal etalon and a molecular iodine laser-induced fluorescence (LIF) detection system. Different nonlinear frequency conversion schemes were used to cover a large frequency range from the infrared to the deep UV. The versatility of the laser system for flow/combustion diagnostics is demonstrated in three applications, namely filtered Rayleigh scattering, high-resolution Doppler-free two-photon LIF of CO, and infrared LIF and polarization spectroscopy of CO2. The potential impacts of using this SLM laser system in laser flow/combustion diagnostic applications are discussed.

  9. The effective degeneracy of protein normal modes

    NASA Astrophysics Data System (ADS)

    Na, Hyuntae; Song, Guang

    2016-06-01

    Normal modes are frequently computed and used to portray protein dynamics and interpret protein conformational changes. In this work, we investigate the nature of normal modes and find that the normal modes of proteins, especially those at the low frequency range (0–600 cm‑1), are highly susceptible to degeneracy. Two or more modes are degenerate if they have the same frequency and consequently any orthogonal transformation of them also is a valid representation of the mode subspace. Thus, degenerate modes can no longer characterize unique directions of motions as regular modes do. Though the normal modes of proteins are usually of different frequencies, the difference in frequency between neighboring modes is so small that, under even slight structural uncertainty that unavoidably exists in structure determination, it can easily vanish and as a result, a mode becomes effectively degenerate with its neighboring modes. This can be easily observed in that some modes seem to disappear and their matching modes cannot be found when the structure used to compute the modes is modified only slightly. We term this degeneracy the effective degeneracy of normal modes. This work is built upon our recent discovery that the vibrational spectrum of globular proteins is universal. The high density of modes observed in the vibrational frequency spectra of proteins renders their normal modes highly susceptible to degeneracy, under even the smallest structural uncertainty. Indeed, we find the degree of degeneracy of modes is proportional to the density of modes in the vibrational spectrum. This means that for modes at the same frequency, degeneracy is more severe for larger proteins. Degeneracy exists also in the modes of coarse-grained models, but to a much lesser extent than those of all-atom models. In closing, we discuss the implications of the effective degeneracy of normal modes: how it may significantly affect the ways in which normal modes are used in various normal modes

  10. The effective degeneracy of protein normal modes.

    PubMed

    Na, Hyuntae; Song, Guang

    2016-01-01

    Normal modes are frequently computed and used to portray protein dynamics and interpret protein conformational changes. In this work, we investigate the nature of normal modes and find that the normal modes of proteins, especially those at the low frequency range (0-600 cm(-1)), are highly susceptible to degeneracy. Two or more modes are degenerate if they have the same frequency and consequently any orthogonal transformation of them also is a valid representation of the mode subspace. Thus, degenerate modes can no longer characterize unique directions of motions as regular modes do. Though the normal modes of proteins are usually of different frequencies, the difference in frequency between neighboring modes is so small that, under even slight structural uncertainty that unavoidably exists in structure determination, it can easily vanish and as a result, a mode becomes effectively degenerate with its neighboring modes. This can be easily observed in that some modes seem to disappear and their matching modes cannot be found when the structure used to compute the modes is modified only slightly. We term this degeneracy the effective degeneracy of normal modes. This work is built upon our recent discovery that the vibrational spectrum of globular proteins is universal. The high density of modes observed in the vibrational frequency spectra of proteins renders their normal modes highly susceptible to degeneracy, under even the smallest structural uncertainty. Indeed, we find the degree of degeneracy of modes is proportional to the density of modes in the vibrational spectrum. This means that for modes at the same frequency, degeneracy is more severe for larger proteins. Degeneracy exists also in the modes of coarse-grained models, but to a much lesser extent than those of all-atom models. In closing, we discuss the implications of the effective degeneracy of normal modes: how it may significantly affect the ways in which normal modes are used in various normal modes

  11. Existence and inter-decadal changes of the Antarctic Circumpolar Wave during the last 142 years and its relationship to large scale modes of variability

    NASA Astrophysics Data System (ADS)

    Cerrone, Dario; Fusco, Giannetta; Cotroneo, Yuri; Simmonds, Ian; Budillon, Giorgio

    2016-04-01

    The Southern Ocean is the region of the world ocean bordering on Antarctica over which important exchanges between the atmosphere, the ocean and the sea ice take place. Here, the strong and nearly unhindered eastward flow of the Antarctic Circumpolar Current (ACC) plays an important control on mean global climate as it transmits climate anomalies around the globe. Features of interannual variability have been often observed to propagate eastward around the Southern Ocean with the circumpolar flow in form of a system of coupled anomalies, known as the Antarctic Circumpolar Wave (ACW). In the present study, using a 142-year series of a composite dataset (850hPa geopotential height, sea level pressure, sea surface temperature, surface meridional wind, surface air temperature) spanning from 1871-2012, the presence of ACWs was investigated. Results show the presence of the ACW before the mid-1950s and interdecadal changes in its variability. Modifications in strength and speed of circumpolar wave have also been observed in connection with large-scale climate changes. CEOF analyses on the same period confirmed that the ACW becomes apparent when there is a constructive combination between the Pacific-South America pattern and the subantarctic zonal wavenumber-3 (ZW3). The analyses also quantify the role played by El-Niño Southern Oscillation (ENSO) teleconnections for the appearance of the ACW. The composite dataset and various climate indices have been also used to diagnose interactions among the Southern Annular Mode (SAM), ENSO and ZW3 circulation patterns on interannual and sub-decadal scales. Results show that SAM and ENSO patterns interact with each other modulating ACW anomalies in the western and central south Pacific Ocean on interannual scale.

  12. A simple strategy for implementing standard reference terminologies in a distributed healthcare delivery system with minimal impact to existing applications.

    PubMed

    Bouhaddou, Omar; Lincoln, Michael J; Maulden, Sarah; Murphy, Holli; Warnekar, Pradnya; Nguyen, Viet; Lam, Siew; Brown, Steven H; Frankson, Ferdinand J; Crandall, Glen; Hughes, Carla; Sigley, Roger; Insley, Marcia; Graham, Gail

    2006-01-01

    The Veterans Administration (VA) has adopted an ambitious program to standardize its clinical terminology to comply with industry-wide standards. The VA is using commercially available tools and in-house software to create a high-quality reference terminology system. The terminology will be used by current and future applications with no planned disruption to operational systems. The first large customer of the group is the national VA Health Data Repository (HDR). Unique enterprise identifiers are assigned to each standard term, and a rich network of semantic relationships makes the resulting data not only recognizable, but highly computable and reusable in a variety of applications, including decision support and data sharing with partners such as the Department of Defense (DoD). This paper describes the specific methods and approaches that the VA has employed to develop and implement this innovative program in existing information system. The goal is to share with others our experience with key issues that face our industry as we move toward an electronic health record for every individual. PMID:17238306

  13. Dual-mode single-crystal photoelastic modulator and possible applications.

    PubMed

    Petkovsek, Rok; Bammer, Ferdinand; Schuöcker, Dieter; Mozina, Janez

    2009-03-01

    A new type of acousto-optic device based on a LiTaO(3) crystal is presented. A harmonic voltage with a proper frequency applied to the piezoelectric LiTaO(3) crystal generates mechanical oscillations in the material. Due to photoelasticity, an artificial modulated birefringence is induced by this oscillation. By using a properly adjusted polarizer and analyzer, the transmission of trough-going polarized light can be modulated. By simultaneous excitation of two modes, an advanced optical response can be achieved. For the applications presented here, the first shear eigenmode must have exactly three times the frequency of the first longitudinal eigenmode. PMID:19252621

  14. Dual-Mode Encoded Magnetic Composite Microsphere Based on Fluorescence Reporters and Raman Probes as Covert Tag for Anticounterfeiting Applications.

    PubMed

    Li, Ruimin; Zhang, Yuting; Tan, Jing; Wan, Jiaxun; Guo, Jia; Wang, Changchun

    2016-04-13

    Utilizing fluorescence reporters and SERS probes as the security labels, a series of dual-mode encoded magnetic composite microspheres with micrometer size was designed and prepared for anticounterfeiting applications. At first, the micro-meter-sized melamine formaldehyde microspheres with different fluorescence molecules (FMF) were prepared by precipitation polymerization, and then the magnetite composite microspheres (FMF/MNPs) were fabricated by direct immobilization of magnetic nanoparticles (MNPs) onto the surface of FMF microspheres. After deposition of Ag nanoparticles (Ag-NPs) onto FMF/MNPs microspheres, the SERS probes were absorbed onto the surface of Ag-NPs, and then a protection layer of silica was coated on the composite microspheres by Stöber method. The combination of different fluorescence reporters and SERS probes greatly increased the encoding complexity and volume for high-level anticounterfeiting. The structure of the dual-encoded FMF/MNPs/Ag-NPs/SiO2 composite microspheres was characterized by FESEM, TEM, FLS(fluorescence spectrometer), XRD, VSM, UV-vis and EDS. The embedded magnetic nanoparticles enable the composite microspheres to be quickly isolated from the marked latex paint by magnet at the concentration of as low as 1 ppm, and the covert tag information can be read out even from one composite microsphere. In addition, the covert security information in the marked coating film can be also read out in situ and the existence of the composite microspheres does not influence the visible appearance of the coating film. All the above outstanding properties will make these dual-mode encoded composite microspheres as advanced security tags for next-generation anticounterfeiting applications. PMID:27010437

  15. Recent Advances In Structural Vibration And Failure Mode Control In Mainland China: Theory, Experiments And Applications

    NASA Astrophysics Data System (ADS)

    Li, Hui; Ou, Jinping

    2008-07-01

    A number of researchers have been focused on structural vibration control in the past three decades over the world and fruit achievements have been made. This paper introduces the recent advances in structural vibration control including passive, active and semiactive control in mainland China. Additionally, the co-author extends the structural vibration control to failure mode control. The research on the failure mode control is also involved in this paper. For passive control, this paper introduces full scale tests of buckling-restrained braces conducted to investigate the performance of the dampers and the second-editor of the Code of Seismic Design for Buildings. For active control, this paper introduces the HMD system for wind-induced vibration control of the Guangzhou TV tower. For semiactive control, the smart damping devices, algorithms for semi-active control, design methods and applications of semi-active control for structures are introduced in this paper. The failure mode control for bridges is also introduced.

  16. Recent Advances In Structural Vibration And Failure Mode Control In Mainland China: Theory, Experiments And Applications

    SciTech Connect

    Li Hui; Ou Jinping

    2008-07-08

    A number of researchers have been focused on structural vibration control in the past three decades over the world and fruit achievements have been made. This paper introduces the recent advances in structural vibration control including passive, active and semiactive control in mainland China. Additionally, the co-author extends the structural vibration control to failure mode control. The research on the failure mode control is also involved in this paper. For passive control, this paper introduces full scale tests of buckling-restrained braces conducted to investigate the performance of the dampers and the second-editor of the Code of Seismic Design for Buildings. For active control, this paper introduces the HMD system for wind-induced vibration control of the Guangzhou TV tower. For semiactive control, the smart damping devices, algorithms for semi-active control, design methods and applications of semi-active control for structures are introduced in this paper. The failure mode control for bridges is also introduced.

  17. Application of failure mode and effects analysis to treatment planning in scanned proton beam radiotherapy

    PubMed Central

    2013-01-01

    Background A multidisciplinary and multi-institutional working group applied the Failure Mode and Effects Analysis (FMEA) approach to the actively scanned proton beam radiotherapy process implemented at CNAO (Centro Nazionale di Adroterapia Oncologica), aiming at preventing accidental exposures to the patient. Methods FMEA was applied to the treatment planning stage and consisted of three steps: i) identification of the involved sub-processes; ii) identification and ranking of the potential failure modes, together with their causes and effects, using the risk probability number (RPN) scoring system, iii) identification of additional safety measures to be proposed for process quality and safety improvement. RPN upper threshold for little concern of risk was set at 125. Results Thirty-four sub-processes were identified, twenty-two of them were judged to be potentially prone to one or more failure modes. A total of forty-four failure modes were recognized, 52% of them characterized by an RPN score equal to 80 or higher. The threshold of 125 for RPN was exceeded in five cases only. The most critical sub-process appeared related to the delineation and correction of artefacts in planning CT data. Failures associated to that sub-process were inaccurate delineation of the artefacts and incorrect proton stopping power assignment to body regions. Other significant failure modes consisted of an outdated representation of the patient anatomy, an improper selection of beam direction and of the physical beam model or dose calculation grid. The main effects of these failures were represented by wrong dose distribution (i.e. deviating from the planned one) delivered to the patient. Additional strategies for risk mitigation, easily and immediately applicable, consisted of a systematic information collection about any known implanted prosthesis directly from each patient and enforcing a short interval time between CT scan and treatment start. Moreover, (i) the investigation of

  18. Application of Failure Mode and Effects Analysis to Intraoperative Radiation Therapy Using Mobile Electron Linear Accelerators

    SciTech Connect

    Ciocca, Mario; Cantone, Marie-Claire; Veronese, Ivan; Cattani, Federica; Pedroli, Guido; Molinelli, Silvia; Vitolo, Viviana; Orecchia, Roberto

    2012-02-01

    Purpose: Failure mode and effects analysis (FMEA) represents a prospective approach for risk assessment. A multidisciplinary working group of the Italian Association for Medical Physics applied FMEA to electron beam intraoperative radiation therapy (IORT) delivered using mobile linear accelerators, aiming at preventing accidental exposures to the patient. Methods and Materials: FMEA was applied to the IORT process, for the stages of the treatment delivery and verification, and consisted of three steps: 1) identification of the involved subprocesses; 2) identification and ranking of the potential failure modes, together with their causes and effects, using the risk probability number (RPN) scoring system, based on the product of three parameters (severity, frequency of occurrence and detectability, each ranging from 1 to 10); 3) identification of additional safety measures to be proposed for process quality and safety improvement. RPN upper threshold for little concern of risk was set at 125. Results: Twenty-four subprocesses were identified. Ten potential failure modes were found and scored, in terms of RPN, in the range of 42-216. The most critical failure modes consisted of internal shield misalignment, wrong Monitor Unit calculation and incorrect data entry at treatment console. Potential causes of failure included shield displacement, human errors, such as underestimation of CTV extension, mainly because of lack of adequate training and time pressures, failure in the communication between operators, and machine malfunctioning. The main effects of failure were represented by CTV underdose, wrong dose distribution and/or delivery, unintended normal tissue irradiation. As additional safety measures, the utilization of a dedicated staff for IORT, double-checking of MU calculation and data entry and finally implementation of in vivo dosimetry were suggested. Conclusions: FMEA appeared as a useful tool for prospective evaluation of patient safety in radiotherapy. The

  19. On-chip whispering-gallery-mode microlasers and their applications for nanoparticle sensing

    NASA Astrophysics Data System (ADS)

    Ozdemir, S. K.; He, L.; Zhu, J.; Monifi, F.; Kim, W.; Kenechukwu, O.; Yilmaz, H.; Huang, S. H.; Yang, L.

    2013-03-01

    Whispering-Gallery-Mode (WGM) resonators are emerging as an excellent platform to study optical phenomena resulting from enhanced light-matter interactions due to their superior capability to confine photons for extended periods of time. The monolithic fabrication process to achieve ultra-high-Q WGM resonators without the need to align multiple optical components, as needed in traditional design of resonators based on precise arrangement of mirrors, is especially attractive. Here we explain how to process a layer of thin film doped with optical gain medium, which is prepared by wet chemical synthesis, into WGM structures on silicon wafer to achieve arrays of ultra-low threshold on-chip microlasers. We can adjust the dopant species and concentration easily by tailoring the chemical compositions in the precursor solution. Lasing in different spectral windows from visible to infrared was observed in the experiments. In particular, we investigated nanoparticle sensing applications of the on-chip WGM microlasers by taking advantages of the narrow linewidths and the splitting of lasing modes arising from their interactions with nano-scale structures. It has been found that a nanoparticle as small as ten nanometers in radius could split a lasing mode in a WGM resonator into two spectrally separated lasing lines. Subsequently, when these lasing lines are photo-mixed at a photodetector a heterodyne beat note is generated which can be processed to signal the detection of individual nanoparticles. We have demonstrated detection of virions, dielectric and metallic nanoparticles by monitoring the changes in this self-heterodyning beat note of the split lasing modes. The built-in self-heterodyne method achieved in this monolithic WGM microlaser provides an ultrasensitive scheme for detecting and measuring nanoparticles at single particle resolution, with a theoretical detection limit of one nanometer.

  20. Anticipating risk for human subjects participating in clinical research: application of Failure Mode and Effects Analysis.

    PubMed

    Cody, Robert J

    2006-03-01

    Failure Mode and Effects Analysis (FMEA) is a method applied in various industries to anticipate and mitigate risk. This methodology can be more systematically applied to the protection of human subjects in research. The purpose of FMEA is simple: prevent problems before they occur. By applying FMEA process analysis to the elements of a specific research protocol, the failure severity, occurrence, and detection rates can be estimated for calculation of a "risk priority number" (RPN). Methods can then be identified to reduce the RPN to levels where the risk/benefit ratio favors human subject benefit, to a greater magnitude than existed in the pre-analysis risk profile. At the very least, the approach provides a checklist of issues that can be individualized for specific research protocols or human subject populations. PMID:16537191

  1. Single-mode interband cascade laser sources for mid-infrared spectroscopic applications

    NASA Astrophysics Data System (ADS)

    Scheuermann, J.; von Edlinger, M.; Weih, R.; Becker, S.; Nähle, L.; Fischer, M.; Koeth, J.; Kamp, M.; Höfling, S.

    2016-05-01

    Compared to the near infrared, many technologically and industrially relevant gas species have more than an order of magnitude higher absorption features in the mid-infrared (MIR) wavelength range. These species include for example important hydrocarbons (methane, acetylene), nitrogen oxides and sulfur oxides. Tunable laser absorption spectroscopy (TLAS) has proven to be a versatile tool for gas sensing applications with significant advantages compared to other techniques. These advantages include real time measurement, standoff detection and ruggedness of the sensor. We present interband cascade lasers (ICLs), which have evolved into important laser sources for the MIR spectral range from 3 to 7 μm. ICLs achieve high efficiency by cascading optically active zones whilst using interband transitions, so they combine common diode laser as well as quantum cascade laser based technologies. Our application grade singlemode distributed feedback devices operate continuous wave at room temperature and are offering several features especially useful for high performance TLAS applications like: side mode suppression ratio of > 30 dB, continuous tuning ranges up to 30 nm, low threshold power densities and low overall power consumption. The devices are typically integrated in a thermoelectrically cooled TO-style package, hermetically sealed using a cap with anti-reflection coated window. This low power consumption as well as the compact size and ruggedness of the fabricated laser sources makes them perfectly suited for battery powered portable solutions for in field spectroscopy applications.

  2. Robotic tele-existence

    NASA Technical Reports Server (NTRS)

    Tachi, Susumu; Arai, Hirohiko; Maeda, Taro

    1989-01-01

    Tele-existence is an advanced type of teleoperation system that enables a human operator at the controls to perform remote manipulation tasks dexterously with the feeling that he or she exists in the remote anthropomorphic robot in the remote environment. The concept of a tele-existence is presented, the principle of the tele-existence display method is explained, some of the prototype systems are described, and its space application is discussed.

  3. Autoresonant control of nonlinear mode in ultrasonic transducer for machining applications.

    PubMed

    Babitsky, V I; Astashev, V K; Kalashnikov, A N

    2004-04-01

    Experiments conducted in several countries have shown that the improvement of machining quality can be promoted through conversion of the cutting process into one involving controllable high-frequency vibration at the cutting zone. This is achieved through the generation and maintenance of ultrasonic vibration of the cutting tool to alter the fracture process of work-piece material cutting to one in which loading of the materials at the tool tip is incremental, repetitive and controlled. It was shown that excitation of the high-frequency vibro-impact mode of the tool-workpiece interaction is the most effective way of ultrasonic influence on the dynamic characteristics of machining. The exploitation of this nonlinear mode needs a new method of adaptive control for excitation and stabilisation of ultrasonic vibration known as autoresonance. An approach has been developed to design an autoresonant ultrasonic cutting unit as an oscillating system with an intelligent electronic feedback controlling self-excitation in the entire mechatronic system. The feedback produces the exciting force by means of transformation and amplification of the motion signal. This allows realisation for robust control of fine resonant tuning to bring the nonlinear high Q-factor systems into technological application. The autoresonant control provides the possibility of self-tuning and self-adaptation mechanisms for the system to keep the nonlinear resonant mode of oscillation under unpredictable variation of load, structure and parameters. This allows simple regulation of intensity of the process whilst keeping maximum efficiency at all times. An autoresonant system with supervisory computer control was developed, tested and used for the control of the piezoelectric transducer during ultrasonically assisted cutting. The system has been developed as combined analog-digital, where analog devices process the control signal, and parameters of the devices are controlled digitally by computer. The

  4. Application of failure mode and effects analysis (FMEA) to pretreatment phases in tomotherapy.

    PubMed

    Broggi, Sara; Cantone, Marie Claire; Chiara, Anna; Di Muzio, Nadia; Longobardi, Barbara; Mangili, Paola; Veronese, Ivan

    2013-01-01

    The aim of this paper was the application of the failure mode and effects analysis (FMEA) approach to assess the risks for patients undergoing radiotherapy treatments performed by means of a helical tomotherapy unit. FMEA was applied to the preplanning imaging, volume determination, and treatment planning stages of the tomotherapy process and consisted of three steps: 1) identification of the involved subprocesses; 2) identification and ranking of the potential failure modes, together with their causes and effects, using the risk probability number (RPN) scoring system; and 3) identification of additional safety measures to be proposed for process quality and safety improvement. RPN upper threshold for little concern of risk was set at 125. A total of 74 failure modes were identified: 38 in the stage of preplanning imaging and volume determination, and 36 in the stage of planning. The threshold of 125 for RPN was exceeded in four cases: one case only in the phase of preplanning imaging and volume determination, and three cases in the stage of planning. The most critical failures appeared related to (i) the wrong or missing definition and contouring of the overlapping regions, (ii) the wrong assignment of the overlap priority to each anatomical structure, (iii) the wrong choice of the computed tomography calibration curve for dose calculation, and (iv) the wrong (or not performed) choice of the number of fractions in the planning station. On the basis of these findings, in addition to the safety strategies already adopted in the clinical practice, novel solutions have been proposed for mitigating the risk of these failures and to increase patient safety. PMID:24036868

  5. Single mode tapered fiber-optic interferometer based refractive index sensor and its application to protein sensing.

    PubMed

    Yadav, T K; Narayanaswamy, R; Abu Bakar, M H; Kamil, Y Mustapha; Mahdi, M A

    2014-09-22

    We demonstrate refractive index sensors based on single mode tapered fiber and its application as a biosensor. We utilize this tapered fiber optic biosensor, operating at 1550 nm, for the detection of protein (gelatin) concentration in water. The sensor is based on the spectroscopy of mode coupling based on core modes-fiber cladding modes excited by the fundamental core mode of an optical fiber when it transitions into tapered regions from untapered regions. The changes are determined from the wavelength shift of the transmission spectrum. The proposed fiber sensor has sensitivity of refractive index around 1500 nm/RIU and for protein concentration detection, its highest sensitivity is 2.42141 nm/%W/V. PMID:25321749

  6. A Sliding Mode Controller Using Nonlinear Sliding Surface Improved With Fuzzy Logic: Application to the Coupled Tanks System

    NASA Astrophysics Data System (ADS)

    Boubakir, A.; Boudjema, F.; Boubakir, C.

    2008-06-01

    This paper proposes an approach of hybrid control that is based on the concept of combining fuzzy logic and the methodology of sliding mode control (SMC). In the present works, a first-order nonlinear sliding surface is presented, on which the developed control law is based. Mathematical proof for the stability and convergence of the system is presented. In order to reduce the chattering in sliding mode control, a fixed boundary layer around the switch surface is used. Within the boundary layer, since the fuzzy logic control is applied, the chattering phenomenon, which is inherent in a sliding mode control, is avoided by smoothing the switch signal. Outside the boundary, the sliding mode control is applied to driving the system states into the boundary layer. Experimental studies carried out on a coupled Tanks system indicate that the proposed fuzzy sliding mode control (FSMC) is a good candidate for control applications.

  7. Application of Normal Mode Expansion to AE Waves in Finite Plates

    NASA Technical Reports Server (NTRS)

    Gorman, M. R.; Prosser, W. H.

    1997-01-01

    Breckenridge et al. (1975), Hsu (1985) and Pao (1978) adapted approaches from seismology to calculate the response at the surface of an infinite half-space and an infinite plate. These approaches have found use in calibrating acoustic emission (AE) transducers. However, it is difficult to extend this theoretical approach to AE testing of practical structures. Weaver and Pao (1982) considered a normal mode solution to the Lamb equations. Hutchinson (1983) pointed out the potential relevance of Mindlin's plate theory (1951) to AE. Pao (1982) reviewed Medick s (1961) classical plate theory for a point source, but rejected it as useful for AE and no one seems to have investigated its relevance to AE any further. Herein, a normal mode solution to the classical plate bending equation was investigated for its applicability to AE. The same source-time function chosen by Weaver and Pao is considered. However, arbitrary source and receiver positions are chosen relative to the boundaries of the plate. This is another advantage of the plate theory treatment in addition to its simplicity. The source does not have to be at the center of the plate as in the axisymmetric treatment. The plate is allowed to remain finite and reflections are predicted. The importance of this theory to AE is that it can handle finite plates, realistic boundary conditions, and can be extended to composite materials.

  8. Application of failure mode and effect analysis in a radiology department.

    PubMed

    Thornton, Eavan; Brook, Olga R; Mendiratta-Lala, Mishal; Hallett, Donna T; Kruskal, Jonathan B

    2011-01-01

    With increasing deployment, complexity, and sophistication of equipment and related processes within the clinical imaging environment, system failures are more likely to occur. These failures may have varying effects on the patient, ranging from no harm to devastating harm. Failure mode and effect analysis (FMEA) is a tool that permits the proactive identification of possible failures in complex processes and provides a basis for continuous improvement. This overview of the basic principles and methodology of FMEA provides an explanation of how FMEA can be applied to clinical operations in a radiology department to reduce, predict, or prevent errors. The six sequential steps in the FMEA process are explained, and clinical magnetic resonance imaging services are used as an example for which FMEA is particularly applicable. A modified version of traditional FMEA called Healthcare Failure Mode and Effect Analysis, which was introduced by the U.S. Department of Veterans Affairs National Center for Patient Safety, is briefly reviewed. In conclusion, FMEA is an effective and reliable method to proactively examine complex processes in the radiology department. FMEA can be used to highlight the high-risk subprocesses and allows these to be targeted to minimize the future occurrence of failures, thus improving patient safety and streamlining the efficiency of the radiology department. PMID:20980666

  9. Mechanically induced long period fiber gratings on single mode tapered optical fiber for structure sensing applications

    NASA Astrophysics Data System (ADS)

    Pulido-Navarro, María. G.; Marrujo-García, Sigifredo; Álvarez-Chávez, José A.; Velázquez-González, Jesús S.; Martínez-Piñón, Fernando; Escamilla-Ambrosio, Ponciano J.

    2015-08-01

    The modal characteristics of tapered single mode optical fibers and its strain sensing characteristics by using mechanically induced long period fiber gratings are presented in this work. Both Long Period Fiber Gratings (LPFG) and fiber tapers are fiber devices that couple light from the core fiber into the fiber cladding modes. The mechanical LPFG is made up of two plates, one flat and the other grooved. For this experiment the grooved plate was done on an acrylic slab with the help of a computer numerical control machine. The manufacturing of the tapered fiber is accomplished by applying heat using an oxygen-propane flame burner and stretching the fiber, which protective coating has been removed. Then, a polymer-tube-package is added in order to make the sensor sufficiently stiff for the tests. The mechanical induced LPFG is accomplished by putting the tapered fiber in between the two plates, so the taper acquires the form of the grooved plate slots. Using a laser beam the transmission spectrum showed a large peak transmission attenuation of around -20 dB. The resultant attenuation peak wavelength in the transmission spectrum shifts with changes in tension showing a strain sensitivity of 2pm/μɛ. This reveals an improvement on the sensitivity for structure monitoring applications compared with the use of a standard optical fiber. In addition to the experimental work, the supporting theory and numerical simulation analysis are also included.

  10. 46 CFR 105.05-3 - New vessels and existing vessels for the purpose of application of regulations in this part.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false New vessels and existing vessels for the purpose of application of regulations in this part. 105.05-3 Section 105.05-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS COMMERCIAL FISHING VESSELS DISPENSING PETROLEUM PRODUCTS Application § 105.05-3...

  11. 40 CFR 63.5798 - What if I want to use, or I manufacture, an application technology (new or existing) whose...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... this subpart? If you wish to use a resin or gel coat application technology (new or existing), whose... description of the resin or gel coat application technology and supporting organic HAP emissions test data... range of resin or gel coat HAP contents to demonstrate the effectiveness of the technology under...

  12. High-order face-shear modes of relaxor-PbTiO3 crystals for piezoelectric motor applications

    NASA Astrophysics Data System (ADS)

    Ci, Penghong; Liu, Guoxi; Chen, Zhijiang; Zhang, Shujun; Dong, Shuxiang

    2014-06-01

    The face-shear vibration modes of [011] poled Zt ± 45° cut relaxor-PT crystals and their applications for linear piezoelectric motors were investigated. Unlike piezoelectric ceramics, the rotated crystal was found to exhibit asymmetric face-shear deformations, and its two high-order face-shear modes degraded into two non-isomorphic modes. As an application example, a standing wave ultrasonic linear motor (10 × 10 × 2 mm3) operating in high-order face-shear vibration modes was developed. The motor exhibits a large driving force (1.5 N) under a low driving voltage (22 Vpp). These findings could provide guidance for design of crystal resonance devices.

  13. Application of range imaging lidar for measurement of mechanical vibration and frequency mode distribution

    NASA Astrophysics Data System (ADS)

    Zhang, Hua A.; Zhu, Yonghao; He, Yun

    1993-05-01

    This article reports the application of laser range imaging radar in the measurement of mechanical vibration frequency and the mode distribution, and the periodic motion of the mechanical parts such as a piston rod. The principle of the laser range imaging radar is based on the phase shift of the reflected amplitude modulated laser beam. The mechanical vibration frequency up to 20 KHZ and the minimal retrieved amplitude (or the motion displacement) of 0.5 mm have been achieved with the laser modulating frequency of 40 MHZ. With appropriate modulating frequency, this laser range system can measure the mechanical vibration amplitude, or the moving displacement, from 10-1 mm up to 102 mm, or even higher to the order of meters, which will be useful to measure the vibration and the periodic motion of machines and their parts for field test.

  14. Optimization of mode numbers of VCSELs for small-cell backhaul applications

    NASA Astrophysics Data System (ADS)

    Lu, I.-Cheng; Wei, Chia-Chien; Shi, Jin-Wei; Chen, Hsing-Yu; Tsai, Sheng-Fan; Hsu, Dar-Zu; Wei, Zhi-Rui; Wun, Jhih-Min; Chen, Jyehong

    2015-07-01

    This paper reports optical orthogonal frequency-division multiplexing (OFDM) transmission using 850 nm Zn-diffusion Vertical-Cavity Surface-Emitting Lasers (VCSELs) and multimode fiber (MMF) for small-cell backhaul applications. We also investigated the influence of side mode suppression ratio (SMSR) on the performance of OFDM modulation. By further optimizing the Zn-diffusion conditions and oxide aperture size, a high-power (6.7 mW) SM (SMSR>30 dB) VCSEL is demonstrated. By using OFDM modulation and bit-loading algorithm, record-high BRDP (91 Gb/s km) at 26 Gb/s transmission under FEC threshold (bit error rate (BER)<3.8×10-3) across 3.5 km OM4 fiber has been successfully demonstrated.

  15. A new general normal mode approach to dynamic tides in rotating stars with realistic structure and its applications

    NASA Astrophysics Data System (ADS)

    Ivanov, P. B.; Papaloizou, J. C. B.; Chernov, S. V.

    We review our recent results on a unified normal model approach to dynamic tides proposed recently in Ivanov, Papaloizou & Chernov (2013) and Chernov, Papaloizou & Ivanov (2013). Our formalism can be used whenever the tidal interactions are mainly determined by normal modes of a star with identifiable regular spectrum of low frequency modes. We provide in the text basic expressions for tidal energy and angular momentum transfer valid both for periodic and parabolic orbits, and different assumptions about effciency of normal mode damping due to viscosity and/or non- linear effects and discuss applications to binary stars and close orbiting extrasolar planets.

  16. Guided-mode resonance in planar photonic crystals: Application to sensing

    NASA Astrophysics Data System (ADS)

    Ganesh, Nikhil

    This dissertation addresses the design, fabrication and characterization of planar photonic crystals that employ the guided-mode resonance effect for sensing and detection applications. A theoretical basis for these applications is first developed, followed by the demonstration of a near-ultraviolet reflectance filter that provides high reflection efficiency in the 400-450 nm spectral range. The response of photonic crystal label-free biosensors is shown to be greatly improved by the use of a near-ultraviolet device, and this improvement in performance is shown to stem from the enhanced surface sensitivity and lowered bulk sensitivity for devices operating in this wavelength range. The application of PCs for wavelength detection is demonstrated by developing a system employing a continuously variable reflectance filter. The system is composed of only two components and allows detection of wavelength changes as small as 0.011 nm. Visible wavelength PCs are also studied for application as fluorescence enhancement biosensors. For the first time, a PC capable of a dual enhancement modality (enhanced excitation and enhanced extraction of fluorescence) is demonstrated for boosting quantum dot fluorescence by over two orders of magnitude. The distance dependence of the enhanced excitation effect is studied and provides clarification for its mechanism and suggests that the PC can be modified to accommodate a wide range of analyte sizes. Finally the enhanced extraction effect is studied in detail using a model system involving quantum dots and waveguide gratings. The results suggest that enhanced extraction can greatly improve the output of fluorophores that are spectrally and spatially matched to the device. A practical demonstration of this effect is carried out in the detection of the cytokine TNF-alpha.

  17. Saturation of the f -mode instability in neutron stars. II. Applications and results

    NASA Astrophysics Data System (ADS)

    Pnigouras, Pantelis; Kokkotas, Kostas D.

    2016-07-01

    We present the first results on the saturation of the f -mode instability in neutron stars due to nonlinear mode coupling. Emission of gravitational waves drives the f -mode (fundamental mode) unstable in fast-rotating, newborn neutron stars. The initial growth phase of the mode is followed by its saturation, because of energy leaking to other modes of the star. The saturation point determines the strain of the generated gravitational-wave signal, which can then be used to extract information about the neutron star's equation of state. The parent (unstable) mode couples via parametric resonances with pairs of daughter modes, with the triplets' evolution exhibiting a rich variety of behaviors. We study both supernova- and merger-derived neutron stars, simply modeled as polytropes in a Newtonian context, and show that the parent may couple to many different daughter pairs during the star's evolution through the instability window, with the saturation amplitude changing by orders of magnitude.

  18. Complementary HFET technology for low-power mixed-mode applications

    SciTech Connect

    Baca, A.G.; Sherwin, M.E.; Zolper, J.C.; Dubbert, D.F.; Hietala, V.M.; Shul, R.J.; Sloan, L.R.; Hafich, M.J.

    1996-06-01

    Development of a complementary heterostructure field effect transistor (CHFET) technology for low-power, mixed-mode digital-microwave applications is presented. An earlier digital CHFET technology with independently optimizable transistors which operated with 319 ps loaded gate delays at 8.9 fJ is reviewed. Then work demonstrating the applicability of the digital nJFET device as a low-power microwave transistor in a hybrid microwave amplifier without any modification to the digital process is presented. A narrow band amplifier with a 0.7 {times} 100 {micro}m nJFET as the active element was designed, constructed, and tested. At 1 mW operating power, the amplifier showed 9.7 dB of gain at 2.15 GHz and a minimum noise figure of 2.5 dB. In addition, next generation CHFET transistors with sub 0.5 {micro}m gate lengths were developed. Cutoff frequencies, f{sub t} of 49 GHz and 11.5 GHz were achieved for n- and p-channel FETs with 0.3 and 0.4 {micro}m gates, respectively. These FETs will enable both digital and microwave circuits with enhanced performance.

  19. Patient Engagement in Cancer Survivorship Care through mHealth: A Consumer-centered Review of Existing Mobile Applications

    PubMed Central

    Geng, Yimin; Myneni, Sahiti

    2015-01-01

    With improvements in early detection and treatment, the number of cancer survivors has been on the rise. Studies suggest that cancer survivors do not often receive proper follow-up care despite existing guidelines. Patient engagement is key to healthy survivorship, and mHealth provides a viable platform to empower survivors with just- in-time personalized support. However, our understanding of existing mHealth solutions in cancer survivorship is limited. In this paper, we use Patient Engagement Framework to investigate existing apps to bridge this knowledge gap. App features are mapped to the framework components to determine the level of engagement facilitated. Ability to record treatment summaries has been found in five out of seven apps examined. While collaborative care and social engagement are found minimally, the majority of features (95%) are limited to information and way finding, e-tools, and interactive forms. Limitations of the existing apps and possible improvements to the framework are discussed. PMID:26958192

  20. Temporal patterns of methane emissions from wetland rice fields treated by different modes of N application

    NASA Astrophysics Data System (ADS)

    Wassmann, R.; Neue, H. U.; Lantin, R. S.; Aduna, J. B.; Alberto, M. C. R.; Andales, M. J.; Tan, M. J.; van der Gon, H. A. C. Denier; Hoffmann, H.; Papen, H.; Rennenberg, H.; Seiler, W.

    1994-08-01

    Methane emission rates from wetland rice fields were determined in Los Baños (Philippines) using an automatic system that allows continuous measurements over time. Methane emission was monitored in an irrigated Aquandic Epiaqualf planted to rice cultivar IR72. Urea fertilizer was applied using four modes: (1) broadcast 10 days after transplanting, (2) broadcast at transplanting, (3) broadcast and incorporated at final harrowing, and (4) deep placement as sulfur-coated granules. The treatments were laid out in a randomized complete block design with four replicates. Measurements were done in the 1991 wet season, 1992 dry season (four treatments), and the 1992 wet season (only treatment 3). Methane emission rates from the experimental plots showed pronounced seasonal and diel variations. The diel pattern of methane emission rates followed a consistent pattern, with highest rates observed in the early afternoon and lowest rates in the early morning. Methane emission rate was generally highest at the ripening stage. The average methane emission rate during the 1992 dry season (190 mg CH4 m-2 d-1) exceeded the average flux rates of the 1992 wet season (79 mg CH4 m-2 d-1) by a factor of 2.4. The total methane emitted from these flooded rice fields amounted to 19 g CH4 m-2 in the dry season with rice yields of 5.2-6.3 t ha-1 and 7 g CH4 m-2 in the wet season with rice yields of 2.4-3.3 t ha-1 regardless of the mode of N application. Significant amounts corresponding to 20% of the methane released under waterlogged conditions were released when the soil was drained after harvest. Emission rates increased sharply when the floodwater receded and macropores started to drain. Emission of methane stopped only when the soil became fully aerated.

  1. Multiple Beam Correlation Using Single-Mode Fiber Optics with Application to Interferometric Imaging

    NASA Astrophysics Data System (ADS)

    Shaklan, Stuart Bruce

    A study of the application of single-mode fiber optics to the multiple-beam interferometric recombination problem is presented. In the laboratory, the fibers have been used in wide bandwidth, two-arm, Mach-Zehnder test interferometers as well as a 5-telescope imaging interferometer connected to an all-fiber beam combiner. Based upon these experiments and some theoretical studies it is shown that fiber optics and fiber optic components such as directional couplers provide an excellent alternative to conventional optics such as mirrors, beamsplitters, and relay lenses. The equations describing the measurement of the complex degree of coherence in an interferometer with a single-mode fiber in each arm are derived. The equations reveal an important feature of the fibers: they filter phase fluctuations due to aberrations and turbulence at the input and convert them to intensity fluctuations at the output. This leads to a simplification of the calibration of measured visibilities. The coupling efficiency of light which has passed through a turbulent atmosphere is also studied as a function of fiber parameters and turbulence conditions for both image motion stabilized and non-stabilized cases. For the former case, coupling efficiency remains greater than 50% as long as telescope diameter is no larger than the turbulence coherence length. Beam combination architectures using arrays of directional couplers are fully discussed. Arrays accommodating up to 20 input beams are presented. The arrays require only N detector pixels for N input beams. A scheme of temporal multiplexing of the phase of each beam is used to identify individual fringe pairs. One possible scheme allows wide bandwidths even for large numbers of beams. A 5-telescope interferometer has been constructed and connected to an all-fiber beam combiner. Two extended objects were observed and reconstructed using standard radio astronomy VLBI software. The interferometer and beam combiner had good thermal and

  2. Microlens system formed on the end of a single mode fiber for laser applications

    NASA Astrophysics Data System (ADS)

    Lee, K. S.

    In this thesis microlenses on the end of single mode fibers were designed, fabricated and tested. In designing this microlens-ended single mode fiber (MSMF) system for laser applications the focusing beam parameters such as minimum spot size W sub 02, minimum spot size position Z sub m, Rayleigh range Z sub R and maximum intensity position Z sub p are very important. These theories state that the focusing beam parameters depend on the lens system parameters and change due to the finite size of the incident beam, finite size of the lens aperture and aberrations. The various types of photoresist microlenses were fabricated on the ends of single mode optical fibers as well as multimode optical fibers using the photolithographic process. The thickness and the radius of curvature of microlenses developed depend on the total exposing energy in the photolithographic process. The developed microlenses were tested by measuring the focusing beam parameters and the intensity distribution near the waist position. Measured focusing beam parameters of microlenses closely follow those expected from the paraxial theory or from the diffraction theory. The shape of the lens also roughly matches the lens shape predicted under some assumptions. Both measured and expected values for (at 830 nm) WO2, Zm and Zr are 0.7 approximately 3.0 micron, 3.5 approximately 20 micron and 0.9 approximately 13 micron, respectively. Various testing apparatus for the spot size measurement, waist position measurement, examination of the intensity distributiona study of the lens surface were built. The minimum spot sizes and minimum spot size positions were measured using the interferometric knife-edge scanning system. The sizes of microlenses were determined by using the scanning electron microscope. Finally, tolerance criteria for the degree of aperturing and spherical aberration in MSMF systems (cutoff wavelength of optical fiber = 690 nm, wavelength of an incident beam = 830 nm) are a/W less than 0

  3. Nonlinear mode coupling in optical fibers and VCSELs and some applications to communication systems

    NASA Astrophysics Data System (ADS)

    Kishore, Kunal

    2000-11-01

    Nonlinear phenomena are relatively easy to observe in optical fibers and semiconductor laser cavities. In optical fibers, nonlinear effects can be seen even at low power due to the high intensities in the small fiber cores and long propagation distances possible in low loss fibers. Semiconductor lasers, in particular, vertical cavity surface emitting lasers (VCSELs), have cavities with very high Q-factors, which result in high intra cavity intensities even at low facet powers. In this thesis we will examine how these nonlinear effects are responsible for coupling between the different modes present in the medium and some applications to optical communication systems. In optical fibers, the nonlinear processes that dominate are self-phase matched processes that automatically satisfy the phase matching condition. These processes include self phase modulation (SPM) and cross phase modulation (XPM). SPM is responsible for the stability and interaction between propagating pulses known as solitons. XPM is responsible for coupling signals with different polarizations or wavelengths propagating in a fiber. In this thesis we have investigated the possibility of controlling the non-linear interaction between solitons, using XPM from another pulse and using this mechanism for pattern recognition in an optical data stream. We demonstrate high-speed (63Gb/s) recognition of 8-bit header words which is a useful function at an add- drop node in an optical network. Both SPM and XPM can be explained in terms of a nonlinear refractive index-a simplification that is made possible by the extremely fast relaxation times in silica (~40fs). In semiconductors the carriers exhibit both fast intra band (~50fs) and spin-flip relaxation (~2ps), and slow inter band dipole relaxation (~Ins). Due to this hierarchy of relaxation times, the interaction of light with the semiconductor medium cannot be described by a single effective refractive index and the carrier dynamics have to be accounted for

  4. Application of attachment modes in the control of large space structures

    NASA Technical Reports Server (NTRS)

    Craig, Roy R., Jr.

    1989-01-01

    Various ways are examined to obtain reduced order mathematical models of structures for use in dynamic response analyses and in controller design studies. Attachment modes are deflection shapes of a structure subjected to specified unit load distributions. Attachment modes are frequently employed to supplement free-interface normal modes to improve the modeling of components (structures) employed in component mode synthesis analyses. Deflection shapes of structures subjected to generalized loads of some specified distribution and of unit magnitude can also be considered to be attachment modes. Several papers which were written under this contract are summarized herein.

  5. An Innovative Structural Mode Selection Methodology: Application for the X-33 Launch Vehicle Finite Element Model

    NASA Technical Reports Server (NTRS)

    Hidalgo, Homero, Jr.

    2000-01-01

    An innovative methodology for determining structural target mode selection and mode selection based on a specific criterion is presented. An effective approach to single out modes which interact with specific locations on a structure has been developed for the X-33 Launch Vehicle Finite Element Model (FEM). We presented Root-Sum-Square (RSS) displacement method computes resultant modal displacement for each mode at selected degrees of freedom (DOF) and sorts to locate modes with highest values. This method was used to determine modes, which most influenced specific locations/points on the X-33 flight vehicle such as avionics control components, aero-surface control actuators, propellant valve and engine points for use in flight control stability analysis and for flight POGO stability analysis. Additionally, the modal RSS method allows for primary or global target vehicle modes to also be identified in an accurate and efficient manner.

  6. Programmable surface deformation: thickness-mode electroactive polymer actuators and their applications

    NASA Astrophysics Data System (ADS)

    Prahlad, Harsha; Pelrine, Ron; Kornbluh, Roy; von Guggenberg, Philip; Chhokar, Surjit; Eckerle, Joseph; Rosenthal, Marcus; Bonwit, Neville

    2005-05-01

    Many different actuator configurations based on SRI International"s dielectric elastomer (DE) type of electroactive polymer (EAP) have been developed for a variety of applications. These actuators have shown excellent actuation properties including maximum actuation strains of up to 380% and energy densities of up to 3.4 J/g, using the planar mode of actuation. Recently, SRI has investigated different configurations of DE actuators that allow complex changes in surface shape and thus the creation of active surface texture. In this configuration, the "active" polymer film is bonded or coated with a thicker passive layer, such that changes in the polymer thickness during actuation of the DE device are at least partially transferred to (and often amplified by) the passive layer. Although the device gives out-of-plane motion, it can nonetheless be fabricated using two-dimensional patterning. The result is a rugged, flexible, and conformal skin that can be spatially actuated by subjecting patterned electrodes on a polymer substrate to an electric field. Using thickness-mode DE, we have demonstrated thickness changes of the order of 0.5 - 2 mm by laminating a passive elastomeric layer to a DE polymer that is only 60 μm in thickness. Such thickness changes would otherwise require a very large number of stacked layers of the DE film to produce comparable surface deformations. Preliminary pressures of 4.2 kPa (0.6 psi) in a direction normal to the plane of the DE film have been measured. However, theoretical calculations indicate that pressures of the order of 100 kPa are feasible using a single layer of DE film. Stacking multiple layers of DE film can lead to a further increase in achievable actuation pressures. Even with current levels of thickness change and actuation pressures, potential applications of such surface texture change are numerous. A thin, compliant pad made from these actuators can have a massaging or sensory augmentation function, and can be incorporated

  7. Bacterium-Like Particles for Efficient Immune Stimulation of Existing Vaccines and New Subunit Vaccines in Mucosal Applications

    PubMed Central

    Van Braeckel-Budimir, Natalija; Haijema, Bert Jan; Leenhouts, Kees

    2013-01-01

    The successful development of a mucosal vaccine depends critically on the use of a safe and effective immunostimulant and/or carrier system. This review describes the effectiveness and mode of action of an immunostimulating particle, derived from bacteria, used in mucosal subunit vaccines. The non-living particles, designated bacterium-like particles are based on the food-grade bacterium Lactococcus lactis. The focus of the overview is on the development of intranasal BLP-based vaccines to prevent diseases caused by influenza and respiratory syncytial virus, and includes a selection of Phase I clinical data for the intranasal FluGEM vaccine. PMID:24062748

  8. Single-Mode, High Repetition Rate, Compact Ho:YLF Laser for Space-Borne Lidar Applications

    NASA Technical Reports Server (NTRS)

    Bai, Yingxin; Yu, Jirong; Wong, Teh-Hwa; Chen, Songsheng; Petros, Mulugeta; Singh, Upendra N.

    2014-01-01

    A single transverse/longitudinal mode, compact Q-switched Ho:YLF laser has been designed and demonstrated for space-borne lidar applications. The pulse energy is between 34-40 mJ for 100-200 Hz operation. The corresponding peak power is >1 MW.

  9. 10 CFR 72.103 - Geological and seismological characteristics for applications for dry cask modes of storage on or...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Geological and seismological characteristics for applications for dry cask modes of storage on or after October 16, 2003. 72.103 Section 72.103 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND...

  10. 10 CFR 72.103 - Geological and seismological characteristics for applications for dry cask modes of storage on or...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Geological and seismological characteristics for applications for dry cask modes of storage on or after October 16, 2003. 72.103 Section 72.103 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND...

  11. 10 CFR 72.103 - Geological and seismological characteristics for applications for dry cask modes of storage on or...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Geological and seismological characteristics for applications for dry cask modes of storage on or after October 16, 2003. 72.103 Section 72.103 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND...

  12. Development of a Conceptual Structure for Aquatic Education and Its Application to Existing Aquatic Curricula and Needed Curriculum Development.

    ERIC Educational Resources Information Center

    Rakow, Steven J.

    1984-01-01

    Northern Minnesota secondary teachers (N=55) were surveyed on their knowledge of a priority for selected water topics. Teachers' assessment of these topic areas provide: (1) a suggested structure for marine education; (2) the evaluation of existing curricula; and (3) needs analysis to determine areas of future curriculum development. (BC)

  13. When the New Application Smell Is Gone: Traditional Intranet Best Practices and Existing Web 2.0 Intranet Infrastructures

    ERIC Educational Resources Information Center

    Yoose, Becky

    2010-01-01

    With the growth of Web 2.0 library intranets in recent years, many libraries are leaving behind legacy, first-generation intranets. As Web 2.0 intranets multiply and mature, how will traditional intranet best practices--especially in the areas of planning, implementation, and evaluation--translate into an existing Web 2.0 intranet infrastructure?…

  14. A Layer Framework to Investigate Student Understanding and Application of the Existence and Uniqueness Theorems of Differential Equations

    ERIC Educational Resources Information Center

    Raychaudhuri, D.

    2007-01-01

    The focus of this paper is on student interpretation and usage of the existence and uniqueness theorems for first-order ordinary differential equations. The inherent structure of the theorems is made explicit by the introduction of a framework of layers concepts-conditions-connectives-conclusions, and we discuss the manners in which students'…

  15. In Vivo application and localization of transcranial focused ultrasound using dual-mode ultrasound arrays.

    PubMed

    Haritonova, Alyona; Liu, Dalong; Ebbini, Emad S

    2015-12-01

    Focused ultrasound (FUS) has been proposed for a variety of transcranial applications, including neuromodulation, tumor ablation, and blood-brain barrier opening. A flurry of activity in recent years has generated encouraging results demonstrating its feasibility in these and other applications. To date, monitoring of FUS beams has been primarily accomplished using MR guidance, where both MR thermography and elastography have been used. The recent introduction of real-time dual-mode ultrasound array (DMUA) systems offers a new paradigm in transcranial focusing. In this paper, we present first experimental results of ultrasound-guided transcranial FUS (tFUS) application in a rodent brain, both ex vivo and in vivo. DMUA imaging is used for visualization of the treatment region for placement of the focal spot within the brain. This includes the detection and localization of pulsating blood vessels at or near the target point(s). In addition, DMUA imaging is used to monitor and localize the FUS-tissue interactions in real time. In particular, a concave (40 mm radius of curvature), 32-element, 3.5-MHz DMUA prototype was used for imaging and tFUS application in ex vivo and in vivo rat models. The ex vivo experiments were used to evaluate the point spread function of the transcranial DMUA imaging at various points within the brain. In addition, DMUA-based transcranial ultrasound thermography measurements were compared with thermocouple measurements of subtherapeutic tFUS heating in rat brain ex vivo. The ex vivo setting was also used to demonstrate the capability of DMUA to produce localized thermal lesions. The in vivo experiments were designed to demonstrate the ability of the DMUA to apply, monitor, and localize subtherapeutic tFUS patterns that could be beneficial in transient blood-brain barrier opening. The results show that although the DMUA focus is degraded due to the propagation through the skull, it still produces localized heating effects within a sub

  16. In Vivo Application and Localization of Transcranial Focused Ultrasound Using Dual-Mode Ultrasound Arrays

    PubMed Central

    Haritonova, Alyona; Liu, Dalong; Ebbini, Emad S.

    2015-01-01

    Focused ultrasound (FUS) has been proposed for a variety of transcranial applications, including neuromodulation, tumor ablation, and blood brain barrier opening. A flurry of activity in recent years has generated encouraging results demonstrating its feasibility in these and other applications. To date, monitoring of FUS beams have been primarily accomplished using MR guidance, where both MR thermography and elastography have been used. The recent introduction of real-time dual-mode ultrasound array (DMUA) systems offers a new paradigm in transcranial focusing. In this paper, we present first experimental results of ultrasound-guided transcranial FUS (tFUS) application in a rodent brain, both ex vivo and in vivo. DMUA imaging is used for visualization of the treatment region for placement of the focal spot within the brain. This includes the detection and localization of pulsating blood vessels at or near the target point(s). In addition, DMUA imaging is used to monitor and localize the FUS-tissue interactions in real-time. In particular, a concave (40-mm radius of curvature), 32-element, 3.5 MHz DMUA prototype was used for imaging and tFUS application in ex vivo and in vivo rat model. The ex vivo experiments were used to evaluate the point spread function (psf) of the transcranial DMUA imaging at various points within the brain. In addition, DMUA-based transcranial ultrasound thermography measurements were compared with thermocouple measurements of subtherapeutic tFUS heating in rat brain ex vivo. The ex vivo setting was also used to demonstrate the DMUA capability to produce localized thermal lesions. The in vivo experiments were designed to demonstrate the ability of the DMUA to apply, monitor, and localize subtherapeutic tFUS patterns that could be beneficial in transient blood brain barrier opening. The results show that, while the DMUA focus is degraded due to the propagation through the skull, it still produces localized heating effects within sub

  17. Highly compliant guided-mode resonance nanogratings: From theory to application in mechanical strain sensing

    NASA Astrophysics Data System (ADS)

    Foland, Steven J.

    This work reports the theory, design, fabrication, and characterization of highly-compliant polymer-based guided-mode resonance (GMR) grating devices. GMR devices have been widely researched in recent years for their applications in telecommunications and biosensing. The vast majority of GMR-based sensors are fabricated and characterized on rigid transparent substrates, and are designed to respond to changes in the optical properties of their surrounding media. While useful in a number of conventional sensing configurations, the applications of rigid gratings for mechanical sensing are extremely limited. To enable a GMR sensor to respond to mechanical stimuli, both the grating and its substrate must be compliant, a property inherent to the devices presented herein. An extensive toolset is required for the design of such resonant optical devices; this dissertation defines the theoretical and simulations models used for the analysis of these dynamic grating devices, and provides a clear understanding of both their strengths and limitations. These tools include a waveguide-theory based theoretical model for rapid approximation of grating resonance conditions, and finite element method (FEM) simulation for full-field solutions to Maxwell's equations. A number of challenges which arise when attempting to fabricate nanostructures on a thin polymer are also addressed, and a fabrication process is developed to enable a practical embodiment of the proposed devices. The results of this process are subwavelength titanium dioxide (TiO2) gratings embedded at the surface of compliant polydimethylsiloxane (PDMS) structures. Both a one-dimensional, membrane-embedded GMR grating for local measurement of microfluidic channel pressure, and a two-dimensional, slab-embedded GMR grating for biaxial strain detection are discussed, demonstrated, and evaluated. Additionally, potential improvements to the devices' performance and suggestions for future work are provided.

  18. Combining whispering gallery mode lasers and microstructured optical fibers for in-vivo biosensing applications

    NASA Astrophysics Data System (ADS)

    François, A.; Rowland, K. J.; Reynolds, T.; Nicholls, S. J.; Monro, T. M.

    2013-10-01

    Whispering Gallery Modes (WGMs) have been widely studied for the past 20 years for various applications, including biological sensing. While the different WGM-based sensing approaches reported in the literature enable useful sensor characteristics, at present this technology is not yet mature, mainly for practical reasons. Our work has been focused on developing a simple, yet efficient, WGM-based sensing platform capable of being used as a dip sensor for in-vivo biosensing applications. We recently demonstrated that a dye-doped polymer microresonator, supporting WGMs, positioned onto the tip of a suspended core Microstructured Optical Fiber can be used as a dip sensor. In this architecture, the resonator is located on an air hole next to the fiber core at the fiber's tip, enabling a significant portion of the sphere to overlap with the guided light emerging from the fiber tip. This architecture offers significant benefits that have never been reported in the literature in terms of radiation efficiency, compared to the standard freestanding resonators, which arise from breaking the symmetry of the resonator. In addition to providing the remote excitation and collection of the WGMs' signal, the fiber also allows easy manipulation of the microresonator and the use this sensor in a dip sensing architecture, alleviating the need for a complex microfluidic interface. Here, we present our recent results on the microstructured fiber tip WGM-based sensor, including its lasing behavior and enhancement of the radiation efficiency as a function of the position of the resonator on the fiber tip. We also show that this platform can be used for clinical diagnostics and applying this technology to the detection of Troponin T, an acute myocardial infarction biomarker, down to a concentration of 7.4 pg/mL.

  19. Annealing of linear birefringence in single-mode fiber coils - Application to optical fiber current sensors

    NASA Technical Reports Server (NTRS)

    Tang, Dingding; Rose, A. H.; Day, G. W.; Etzel, Shelley M.

    1991-01-01

    Annealing procedures that greatly reduce linear birefringence in single-mode fiber coils are described. These procedures have been successfully applied to coils ranging from 5 mm to 10 cm in diameter and up to 200 or more turns. They involve temperature cycles that last 3-4 days and reach maximum temperatures of about 850 C. The residual birefringence and induced loss are minimized by proper selection of fiber. The primary application of these coils is optical fiber current sensors, where they yield small sensors that are more stable than those achieved by other techniques. A current sensor with a temperature stability of 8.4 x 10 to the -5th/K over the range from -75 to 145 C has been demonstrated. This is approximately 20 percent greater than the temperature dependence of the Verdet constant. Packaging degrades the stability, but a packaged sensor coil with a temperature stability of about 1.6 + 10 to the -4th/K over the range from -20 to 120 C has also been demonstrated.

  20. Single Mode SU8 Polymer Based Mach-Zehnder Interferometer for Bio-Sensing Application

    NASA Astrophysics Data System (ADS)

    Boiragi, Indrajit; Kundu, Sushanta; Makkar, Roshan; Chalapathi, Krishnamurthy

    2011-10-01

    This paper explains the influence of different parameters to the sensitivity of an optical waveguide Mach-Zehnder Interferometer (MZI) for real time detection of biomolecules. The sensing principle is based on the interaction of evanescence field with the biomolecules that get immobilized on sensing arm. The sensitivity has been calculated by varying the sensing window length, wavelength and concentration of bio-analyte. The maximum attainable sensitivity for the preferred design is the order of 10-8 RIU at 840 nm wavelength with a sensing window length of 1cm. All the simulation work has been carried out with Opti-BPMCAD for the optimization of MZI device parameters. The SU8 polymers are used as a core and clad material to fabricate the waveguide. The refractive index of cladding layer is optimized by varying the curing temperature for a fixed time period and the achieved index difference between core and clad is Δn = 0.0151. The fabricated MZI device has been characterized with LASER beam profiler at 840 nm wavelength. This study demonstrates the effectiveness of the different parameter to the sensitivity of a single mode optical waveguide Mach-Zehnder Interferometer for bio-sensing application.

  1. Protein-modified shear mode film bulk acoustic resonator for bio-sensing applications

    NASA Astrophysics Data System (ADS)

    Wang, Jingjing; Liu, Weihui; Xu, Yan; Chen, Da; Li, Dehua; Zhang, Luyin

    2014-09-01

    In this paper, we present a shear mode film bulk acoustic biosensor based on micro-electromechanical technology. The film bulk acoustic biosensor is a diaphragmatic structure consisting of a lateral field excited ZnO piezoelectric film piezoelectric stack built on an Si3N4 membrane. The device works at near 1.6 GHz with Q factors of 579 in water and 428 in glycerol. A frequency shift of 5.4 MHz and a small decline in the amplitude are found for the measurements in glycerol compared with those in water because of the viscous damping derived from the adjacent glycerol. For bio-sensing demonstration, the resonator was modified with biotin molecule to detect protein-ligand interactions in real-time and in situ. The resonant frequency of the biotin-modified device drops rapidly and gradually reaches equilibrium when exposed to the streptavidin solution due to the biotin-streptavidin interaction. The proposed film bulk acoustic biosensor shows promising applications for disease diagnostics, prognosis, and drug discovery.

  2. Focal plane readout for 2-D LWIR application implemented with current mode background suppression per pixel

    NASA Astrophysics Data System (ADS)

    Woo, Doo Hyung; Kang, Sang Gu; Lee, Hee Chul

    2004-02-01

    In this paper, a readout technique involving current mode background suppression is studied for 2-dimensional infrared focal plane arrays (IR FPA"s). This technique has a current memory per pixel, and the suppression current can be optimized per pixel element. Capacitive transimpedende amplifier (CTIA) and feedback amplifier structure are adopted for input circuit and background suppression circuit, respectively. Feedback amplifier structure can minimize skimming error due to channel length modulation. The area size of the pixel circuit is generally limited in the case of 2-D application. So, the amplifier used in the CTIA input circuit adopts timesharing for background suppression. To further improve the area limitation, a half circuit of the CTIA is shared in row circuit out of the pixel array. Because of the leakage of the current memory, the skimming data of the current memory in the pixel array is stored in SRAM array through ADC, and is refreshed periodically with SRAM data through DAC. The readout circuit was fabricated using 0.6um 2-poly 3-metal CMOS process for 64 x 64 LWIR HgCdTe IR array with the pixel size of 50um x 50um. The measurement performance of the skimming circuit exhibits about only 3% error for 100nA background current. The simulation results exhibit that skimming error can be reduced further to 0.3% when the ratioed current mirror scheme and/or multi step refresh scheme is adopted.

  3. Forward Modeling of Standing Kink Modes in Coronal Loops. II. Applications

    NASA Astrophysics Data System (ADS)

    Yuan, Ding; Van Doorsselaere, Tom

    2016-04-01

    Magnetohydrodynamic waves are believed to play a significant role in coronal heating, and could be used for remote diagnostics of solar plasma. Both the heating and diagnostic applications rely on a correct inversion (or backward modeling) of the observables into the thermal and magnetic structures of the plasma. However, due to the limited availability of observables, this is an ill-posed issue. Forward modeling is designed to establish a plausible mapping of plasma structuring into observables. In this study, we set up forward models of standing kink modes in coronal loops and simulate optically thin emissions in the extreme ultraviolet bandpasses, and then adjust plasma parameters and viewing angles to match three events of transverse loop oscillations observed by the Solar Dynamics Observatory/Atmospheric Imaging Assembly. We demonstrate that forward models could be effectively used to identify the oscillation overtone and polarization, to reproduce the general profile of oscillation amplitude and phase, and to predict multiple harmonic periodicities in the associated emission intensity and loop width variation.

  4. A review of existing gas-cooled reactor circulators with application of the lessons learned to the new production reactor circulators

    SciTech Connect

    White, L.S.

    1990-07-01

    This report presents the results of a study of the lessons learned during the design, testing, and operation of gas-cooled reactor coolant circulators. The intent of this study is to identify failure modes and problem areas of the existing circulators so this information can be incorporated into the design of the circulators for the New Production Reactor (NPR)-Modular High-Temperature Gas Cooled Reactor (MHTGR). The information for this study was obtained primarily from open literature and includes data on high-pressure, high-temperature helium test loop circulators as well as the existing gas cooled reactors worldwide. This investigation indicates that trouble free circulator performance can only be expected when the design program includes a comprehensive prototypical test program, with the results of this test program factored into the final circulator design. 43 refs., 7 tabs.

  5. Nonlinear Network Modes in Cyclic Systems with Applications to Connected Vehicles

    NASA Astrophysics Data System (ADS)

    Avedisov, Sergei S.; Orosz, Gábor

    2015-08-01

    In this paper, we propose a novel technique to decompose networked systems with cyclic structure into nonlinear modes and apply these ideas to a system of connected vehicles. We perform linear and nonlinear transformations that exploit the network structure and lead to nonlinear modal equations that are decoupled. Each mode can be obtained by solving a small set of algebraic equations without deriving the coefficients for any other mode. By focusing on the mode that is loosing stability, bifurcation analysis can be carried out. The techniques developed are applied to evaluate the impact of connected cruise control on the nonlinear dynamics of a connected vehicle system.

  6. 40 CFR Table 3 to Subpart Zzzzz of... - Applicability of General Provisions to New and Existing Affected Sources Classified as Large...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 15 2012-07-01 2012-07-01 false Applicability of General Provisions to New and Existing Affected Sources Classified as Large Foundries 3 Table 3 to Subpart ZZZZZ of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS...

  7. 40 CFR 63.5798 - What if I want to use, or I manufacture, an application technology (new or existing) whose...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true What if I want to use, or I manufacture, an application technology (new or existing) whose organic HAP emissions characteristics are not represented by the equations in Table 1 to this subpart? 63.5798 Section 63.5798 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...

  8. 13 CFR 120.837 - SBA decision on application for a new CDC or for an existing CDC to expand Area of Operations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... benchmarks, including pre-approval and annual review by SBA of any management or staff contracts, and the... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false SBA decision on application for a new CDC or for an existing CDC to expand Area of Operations. 120.837 Section 120.837 Business...

  9. 40 CFR Table 3 to Subpart Zzzzz of... - Applicability of General Provisions to New and Existing Affected Sources Classified as Large...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 14 2010-07-01 2010-07-01 false Applicability of General Provisions to New and Existing Affected Sources Classified as Large Foundries 3 Table 3 to Subpart ZZZZZ of Part 63... Affected Sources Classified as Large Foundries As required in § 63.10900(a), you must meet each...

  10. Temporal patterns of methane emissions from wetland rice fields treated by different modes of N application

    SciTech Connect

    Wassmann, R.; Neue, H.U.; Lantin, R.S.; Aduna, J.B.; Alberto, M.C.R.; Andales, M.J.; Tan, M.J.; Hoffmann, H.; Papen, H.; Gon, H.A.C. D. van der

    1994-08-20

    Methane emission rates from wetland rice fields were determined in Los Banos (Philipppines) using an automatic system that allows continuous measurements over time. Methane emission was monitored in an irrigated Aquandic Epiaqualf planted to rice cultivar IR72. Urea fertilizer was applied using four modes: (1) broadcast 10 days after transplanting, (2) broadcast at transplanting, (3) broadcast and incorporated at final harrowing, and (4) deep placement as sulfur-coated granules. The treatments were laid out in a randomized complete block design with four replicates. Measurements were done in the 1991 wet season, 1992 dry season (four treatments), and the 1992 wet season (only treatment 3). Methane emission rates from the experimental plots showed pronounced season and diel variations. The diel pattern of methane emission rates followed a consistent pattern, with highest rates observed in the early afternoon and lowest rates in the early morning. Methane emission rate was generally highest at the ripening stage. The average methane emission rate during the 1992 dry season (190 mg CH{sub 4} m{sup {minus}2} d{sup {minus}1}) exceeded the average flux rates of the 1992 wet season (79 mg CH{sub 4} m{sup {minus}2} d{sup {minus}1}) by a factor of 2.4. The total methane emitted from these flooded rice fields amounted to 19 g CH{sub 4} m{sup {minus}2} in the dry season with rice yields of 5.2-6.3 ha{sup {minus}1} and 7 g CH{sub 4} m{sup {minus}2} in the wet season with rice yields of 2.4-3.3 t ha{sup {minus}1} regardless of the mode of N application. Significant amounts corresponding to 20% of the methane released under waterlogged conditions were released when the soil was drained after harvest. Emission rates increased sharply when the floodwater receded and macropores started to drain. Emission of methane stopped only when the soil became fully aerated. 25 refs., 5 figs., 1 tab.

  11. Dynamic Mode Decomposition (DMD) application to premixed Low Swirl Injector flames

    NASA Astrophysics Data System (ADS)

    Palies, Paul; Cheng, Robert; Davis, Dustin; Ilak, Milos

    2015-11-01

    DMD is implemented and applied to premixed flame image data from the Low Swirl Injector. The data consists of high speed video flame images at three different equivalence ratios, corresponding to low-amplitude oscillation, transient growth, and high-amplitude oscillation regimes. DMD reveals spectra of growth rates and frequencies with corresponding spatial modes, ranked by mode norm. For the low-amplitude oscillation regime, DMD does not capture any dominant mode shapes or frequencies. For the high-amplitude oscillation case, the frequency of the dominant mode and its harmonics match the frequency recorded by pressure measurement. The spatial mode from DMD is used to extract the propagation velocity of perturbations. In the transient regime, DMD captures the growth rate and frequency of the transient mode. The corresponding DMD spatial mode shows a similar shape to the high oscillation case indicating that the transition to a limit cycle is associated with a convective mode. The underlying mechanism of unsteady heat release is identified as induced by a convected wave along the flame front, whose velocity is confirmed by a separate analysis. Supported by Dept. of Energy Contract No. DE-AC02-05CH11231.

  12. Adaptive mode transition control architecture with an application to unmanned aerial vehicles

    NASA Astrophysics Data System (ADS)

    Gutierrez Zea, Luis Benigno

    In this thesis, an architecture for the adaptive mode transition control of unmanned aerial vehicles (UAV) is presented. The proposed architecture consists of three levels: the highest level is occupied by mission planning routines where information about way points the vehicle must follow is processed. The middle level uses a trajectory generation component to coordinate the task execution and provides set points for low-level stabilizing controllers. The adaptive mode transitioning control algorithm resides at the lowest level of the hierarchy consisting of a mode transitioning controller and the accompanying adaptation mechanism. The mode transition controller is composed of a mode transition manager, a set of local controllers, a set of active control models, a set point filter, a state filter, an automatic trimming mechanism and a dynamic compensation filter. Local controllers operate in local modes and active control models operate in transitions between two local modes. The mode transition manager determines the actual mode of operation of the vehicle based on a set of mode membership functions and activates a local controller or an active control model accordingly. The adaptation mechanism uses an indirect adaptive control methodology to adapt the active control models. For this purpose, a set of plant models based on fuzzy neural networks is trained based on input/output information from the vehicle and used to compute sensitivity matrices providing the linearized models required by the adaptation algorithms. The effectiveness of the approach is verified through software-in-the-loop simulations, hardware-in-the-loop simulations and flight testing.

  13. 40 CFR 60.3060 - When must I submit a title V permit application for my existing unit?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Incinerators Used in Disaster Recovery ...(d), and 502(a) of the Clean Air Act and 40 CFR 70.5(a)(1)(i) and 40 CFR 71.5(a)(1)(i).) (i) 12... Tribal plan. (ii) 12 months after the effective date of any applicable Federal plan. (iii) December...

  14. 40 CFR 60.3060 - When must I submit a title V permit application for my existing unit?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Incinerators Used in Disaster Recovery ...(d), and 502(a) of the Clean Air Act and 40 CFR 70.5(a)(1)(i) and 40 CFR 71.5(a)(1)(i).) (i) 12... Tribal plan. (ii) 12 months after the effective date of any applicable Federal plan. (iii) December...

  15. 40 CFR 60.3060 - When must I submit a title V permit application for my existing unit?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Incinerators Used in Disaster Recovery ...(d), and 502(a) of the Clean Air Act and 40 CFR 70.5(a)(1)(i) and 40 CFR 71.5(a)(1)(i).) (i) 12... Tribal plan. (ii) 12 months after the effective date of any applicable Federal plan. (iii) December...

  16. 40 CFR 60.3060 - When must I submit a title V permit application for my existing unit?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Incinerators Used in Disaster Recovery ...(d), and 502(a) of the Clean Air Act and 40 CFR 70.5(a)(1)(i) and 40 CFR 71.5(a)(1)(i).) (i) 12... Tribal plan. (ii) 12 months after the effective date of any applicable Federal plan. (iii) December...

  17. Applicability of mode-coupling theory to polyisobutylene: A molecular dynamics simulation study

    NASA Astrophysics Data System (ADS)

    Khairy, Y.; Alvarez, F.; Arbe, A.; Colmenero, J.

    2013-10-01

    The applicability of Mode Coupling Theory (MCT) to the glass-forming polymer polyisobutylene (PIB) has been explored by using fully atomistic molecular dynamics simulations. MCT predictions for the so-called asymptotic regime have been successfully tested on the dynamic structure factor and the self-correlation function of PIB main-chain carbons calculated from the simulated cell. The factorization theorem and the time-temperature superposition principle are satisfied. A consistent fitting procedure of the simulation data to the MCT asymptotic power-laws predicted for the α-relaxation regime has delivered the dynamic exponents of the theory—in particular, the exponent parameter λ—the critical non-ergodicity parameters, and the critical temperature Tc. The obtained values of λ and Tc agree, within the uncertainties involved in both studies, with those deduced from depolarized light scattering experiments [A. Kisliuk , J. Polym. Sci. Part B: Polym. Phys.JPBPEM0887-626610.1002/1099-0488(20001101)38:21<2785::AID-POLB70>3.0.CO;2-S 38, 2785 (2000)]. Both, λ and Tc/Tg values found for PIB are unusually large with respect to those commonly obtained in low molecular weight systems. Moreover, the high Tc/Tg value is compatible with a certain correlation of this parameter with the fragility in Angell's classification. Conversely, the value of λ is close to that reported for real polymers, simulated “realistic” polymers and simple polymer models with intramolecular barriers. In the framework of the MCT, such finding should be the signature of two different mechanisms for the glass-transition in real polymers: intermolecular packing and intramolecular barriers combined with chain connectivity.

  18. 980 nm diode laser with automatic power control mode for dermatological applications

    NASA Astrophysics Data System (ADS)

    Belikov, Andrey V.; Gelfond, Mark L.; Shatilova, Ksenia V.; Sosenkova, Svetlana A.; Lazareva, Anastasia A.

    2015-07-01

    Results of nevus, papilloma, dermatofibroma, and basal cell skin cancer removal by a 980+/-10 nm diode laser with "blackened" tip operating in continuous (CW) mode and automatic power control (APC) mode are compared. It was demonstrated that using APC mode decreases the width of collateral damage at removing of these nosological neoplasms of human skin. The mean width of collateral damage reached 0.846+/-0.139 mm for patient group with nevus removing by 980 nm diode laser operating in CW mode, papilloma - 0.443+/-0.312 mm, dermatofibroma - 0.923+/-0.271 mm, and basal cell skin cancer - 0.787+/-0.325 mm. The mean width of collateral damage reached 0.592+/-0.197 mm for patient group with nevus removing by 980 nm diode laser operating in APC mode, papilloma - 0.191+/-0.162 mm, dermatofibroma - 0.476+/-0.366 mm, and basal cell skin cancer - 0.517+/-0.374 mm. It was found that the percentage of laser wounds with collateral damage less than 300 μm of quantity of removed nosological neoplasms in APC mode is 50%, that significantly higher than the percentage of laser wounds obtained using CW mode (13.4%).

  19. Application of empirical mode decomposition to very low frequency signals for identification of seismic-ionospheric precursor phenomena

    NASA Astrophysics Data System (ADS)

    Skeberis, Christos; Xenos, Dimitrios T.; Xenos, Thomas D.; Contadakis, Michael E.; Arabelos, Dimitrios; Chatzopoulou, Georgia

    2012-05-01

    This study investigates the application of empirical mode decomposition to signals from very low frequency transmitters in Europe that were received in Thessaloniki, Greece, to provide a method for depicting seismic-ionospheric precursor phenomena that occur prior to an earthquake. The basis for ionosphere interactions with seismic phenomena has been well documented in past studies, and the depiction of disturbances applied from the earthionosphere waveguide on the received signals was the purpose of this study. Empirical mode decomposition is a method for processing of nonlinear and nonstationary signals, to decompose them into their functional components, known as intrinsic mode functions. This method can provide high pass filtering to signals, thus depicting a clearer image of any abnormal disturbances in the signals that are not part of the normal noise content. Observations of such precursor phenomena are presented and correlated to earthquakes, to demonstrate the effectiveness of this method.

  20. The Psychoanalytic Mode of Thought and its Application To the Non-Normative Analysis of Sexuality and Gender.

    PubMed

    Kloppenberg, Brian

    2016-02-01

    Freud's psychoanalytic mode of thought, especially as interpreted by William Grossman, functions as an inherently non-normative means of analyzing both the psychic life of the individual and various historical and cultural phenomena. Application of this mode of thought to particular characterizations of gender and sexuality makes possible an essential critique of trait psychology and static formulations of human development, as restricting both clinical practice and theory building. An exploration of the complexities of sexuality and gender in gay men shows how Freud's insistence on variability lends conceptual power at the intersection of classical psychoanalysis, with its problematic history, and the many clinical and theoretical manifestations of contemporary psychoanalysis. The non-normative psychoanalytic mode of thought developed by Freud must be integrated with more recent formulations about gender and sexuality in order to conduct a psychoanalysis. PMID:26819349

  1. Case studies: Application of SEA in provincial level expressway infrastructure network planning in China - Current existing problems

    SciTech Connect

    Zhou Kaiyi; Sheate, William R.

    2011-11-15

    Since the Law of the People's Republic of China on Environmental Impact Assessment was enacted in 2003 and Huanfa 2004 No. 98 was released in 2004, Strategic Environmental Assessment (SEA) has been officially being implemented in the expressway infrastructure planning field in China. Through scrutinizing two SEA application cases of China's provincial level expressway infrastructure (PLEI) network plans, it is found that current SEA practice in expressway infrastructure planning field has a number of problems including: SEA practitioners do not fully understand the objective of SEA; its potential contributions to strategic planning and decision-making is extremely limited; the employed application procedure and prediction and assessment techniques are too simple to bring objective, unbiased and scientific results; and no alternative options are considered. All these problems directly lead to poor quality SEA and consequently weaken SEA's effectiveness.

  2. 40 CFR 60.5245 - When must I submit a title V permit application for my existing SSI unit?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 CFR 70.5(a)(1)(i) and 40 CFR 71.5(a)(1)(i)). (1) 12 months after the effective date of any.... (See section 503(c) of the Clean Air Act and 40 CFR 70.3(a) and (b), 40 CFR 70.5(a)(1)(i), 40 CFR 71.3(a) and (b), and 40 CFR 71.5(a)(1)(i).) (d) A “complete” title V permit application is one that...

  3. Failure mode analysis using state variables derived from fault trees with application

    SciTech Connect

    Bartholomew, R.J.

    1981-01-01

    Fault Tree Analysis (FTA) is used extensively to assess both the qualitative and quantitative reliability of engineered nuclear power systems employing many subsystems and components. FTA is very useful, but the method is limited by its inability to account for failure mode rate-of-change interdependencies (coupling) of statistically independent failure modes. The state variable approach (using FTA-derived failure modes as states) overcomes these difficulties and is applied to the determination of the lifetime distribution function for a heat pipe-thermoelectric nuclear power subsystem. Analyses are made using both Monte Carlo and deterministic methods and compared with a Markov model of the same subsystem.

  4. Extension of the broadband single-mode integrated optical waveguide technique to the ultraviolet spectral region and its applications.

    PubMed

    Wiederkehr, Rodrigo S; Mendes, Sergio B

    2014-03-21

    We report here the fabrication, characterization, and application of a single-mode integrated optical waveguide (IOW) spectrometer capable of acquiring optical absorbance spectra of surface-immobilized molecules in the visible and ultraviolet spectral region down to 315 nm. The UV-extension of the single-mode IOW technique to shorter wavelengths was made possible by our development of a low-loss single-mode dielectric waveguide in the UV region based on an alumina film grown by atomic layer deposition (ALD) over a high quality fused silica substrate, and by our design/fabrication of a broadband waveguide coupler formed by an integrated diffraction grating combined with a highly anamorphic optical beam of large numerical aperture. As an application of the developed technology, we report here the surface adsorption process of bacteriochlorophyll a on different interfaces using its Soret absorption band centred at 370 nm. The effects of different chemical compositions at the solid-liquid interface on the adsorption and spectral properties of bacteriochlorophyll a were determined from the polarized UV-Vis IOW spectra acquired with the developed instrumentation. The spectral extension of the single-mode IOW technique into the ultraviolet region is an important advance as it enables extremely sensitive studies in key characteristics of surface molecular processes (e.g., protein unfolding and solvation of aromatic amino-acid groups under surface binding) whose spectral features are mainly located at wavelengths below the visible spectrum. PMID:24466569

  5. Extension of the broadband single-mode integrated optical waveguide technique to the ultraviolet spectral region and its applications

    PubMed Central

    Wiederkehr, Rodrigo S.; Mendes, Sergio B.

    2014-01-01

    We report here the fabrication, characterization, and application of a single-mode integrated optical waveguide (IOW) spectrometer capable of acquiring optical absorbance spectra of surface-immobilized molecules in the visible and ultraviolet spectral region down to 315 nm. The UV-extension of the single-mode IOW technique to shorter wavelengths was made possible by our development of a low-loss single-mode dielectric waveguide in the UV region based on an alumina film grown by atomic layer deposition (ALD) over a high quality fused silica substrate, and by our design/fabrication of a broadband waveguide coupler formed by an integrated diffraction grating combined with a highly anamorphic optical beam of large numerical aperture. As an application of the developed technology, we report here the surface adsorption process of bacteriochlorophyll a on different interfaces using its Soret absorption band centred at 370 nm. The effects of different chemical compositions at the solid/liquid interface on the adsorption and spectral properties of bacteriochlorophyll a were determined from the polarized UV-Vis IOW spectra acquired with the developed instrumentation. The spectral extension of the single-mode IOW technique into the ultraviolet region is an important advance as it enables extremely sensitive studies in key characteristics of surface molecular processes (e.g., protein unfolding and solvation of aromatic amino-acid groups under surface binding) whose spectral features are mainly located at wavelengths below the visible spectrum. PMID:24466569

  6. In vivo evaluation of a mechanically oscillating dual-mode applicator for ultrasound imaging and thermal ablation.

    PubMed

    Owen, Neil R; Bouchoux, Guillaume; Seket, Belhassen; Murillo-Rincon, Adriana; Merouche, Samir; Birer, Alain; Paquet, Christian; Delabrousse, Eric; Chapelon, Jean-Yves; Berriet, Rémi; Fleury, Gérard; Lafon, Cyril

    2010-01-01

    Unresectable liver tumors are often treated with interstitial probes that modify tissue temperature, and efficacious treatment relies on image guidance for tissue targeting and assessment. Here, we report the in vivo evaluation of an interstitial applicator with a mechanically oscillating five-element dual-mode transducer. After thoroughly characterizing the transducer, tissue response to high-intensity ultrasound was numerically calculated to select parameters for experimentation in vivo. Using perfused porcine liver, B-mode sector images were formed before and after a 120-s therapy period, and M-mode imaging monitored the therapy axis during therapy. The time-averaged transducer surface intensity was 21 or 27 W/cm (2). Electroacoustic conversion efficiency was maximally 72 +/- 3% and impulse response length was 295 +/- 1.0 ns at -6 dB. The depth of thermal damage measured by gross histology ranged from 10 to 25 mm for 13 insertion sites. For six sites, M-mode data exhibited a reduction in gray-scale intensity that was interpreted as the temporal variation of coagulation necrosis. Contrast ratio analysis indicated that the gray-scale intensity dropped by 7.8 +/- 3.3 dB, and estimated the final lesion depth to an accuracy of 2.3 +/- 2.4 mm. This paper verified that the applicator could induce coagulation necrosis in perfused liver and demonstrated the feasibility of real-time monitoring. PMID:19497808

  7. Psychosocial Assessment of Artificial Pancreas (AP): Commentary and Review of Existing Measures and Their Applicability in AP Research

    PubMed Central

    Hood, Korey K.; Weissberg-Benchell, Jill; Aldred, Chris; Oliver, Nick; Laffel, Lori

    2015-01-01

    Abstract Aim: This study aimed to systematically review the evidence base for the use of existing psychological and psychosocial measures suitable for use in artificial pancreas (AP) research. Materials and Methods: This systematic review of published literature, gray literature, previous systematic reviews, and qualitative and economic studies was conducted using terms and abbreviations synonymous with diabetes, AP, and quality of life (QoL). Results: Two hundred ninety-two abstracts were identified that reported psychosocial assessment of diabetes-related technologies. Of these, nine met the inclusion criteria and were included. Only four of 103 ongoing trials evaluated psychosocial aspects as an outcome in the trial. Of these, treatment satisfaction, acceptance and use intention of AP, fear of hypoglycemia episodes, satisfaction with AP, and an unspecified QoL measure were used. Conclusions: A better understanding of the psychosocial side of AP systems and the extent to which human factors play a role in the uptake and efficient use of these systems will ultimately lead to the most benefit for people with diabetes. PMID:25549042

  8. The PERC{trademark} process: Existing and potential applications for induction coupled plasma technology in hazardous and radioactive waste treatment

    SciTech Connect

    Blutke, A.S.; Vavruska, J.S.; Serino, J.F.

    1996-12-31

    Plasma Technology, Inc. (PTI), a Santa Fe, New Mexico corporation has developed the Plasma Energy Recycle and Conversion (PERC){trademark} treatment process as a safe and environmentally clean alternative to conventional thermal destruction technologies. The PERC{trademark} treatment process uses as its heat source an advanced Induction Coupled Plasma (ICP) torch connected to a reaction chamber system with an additional emission control system. For example, organic-based gas, liquid, slurry, and/or solid waste streams can be converted into usable or even salable products while residual emissions are reduced to an absolute minimum. In applications for treatment of hazardous and radioactive waste streams, the PERC system could be used for destruction of the hazardous organic constituents and/or significant waste volume reduction while capturing the radioactive fraction in a non-leachable form. Like Direct Current (DC) and Alternating Current (AC) arc plasma systems, ICP torches offer sufficient energy to decompose, melt and/or vitrify any waste stream. The decision for an arc plasma or an IC plasma system has to be made on a case by case evaluation and is highly dependent on the specific waste stream`s form and composition. Induction coupled plasma technology offers one simple, but significant difference compared to DC or AC arc plasma systems: the ICP torch is electrodeless. To date, enormous research effort has been spent to improve the lifetime of electrodes and the effectiveness of related cooling systems. Arc plasma systems are established in research laboratories worldwide and are approaching a broad use in commercial applications. ICP technology has been improved relatively recently, but nowadays offers complete new and beneficial approaches in the field of waste conversion and treatment.

  9. Application of B+M-Mode Ultrasonography in Assessing Deglutitive Tongue Movements in Healthy Adults

    PubMed Central

    Li, Changtian; Li, Junlai; Zhang, Changsheng; Cao, Xiaolin; Li, Nan; Song, Danfei; Yu, Tengfei

    2015-01-01

    Background The purpose of this study was to evaluate tongue movements during swallowing in healthy adults using the B+M-mode ultrasonography, and to determine a common feature in the M-mode traces for quantitative measurement and individual comparison of tongue movements. Material/Methods Ninety healthy subjects were divided into 3 groups according to age (20–39, 40–59, and 60–80 years). The tongue movements during 3 saliva swallows were examined using real-time B+M-mode ultrasonography. The M-mode traces of tongue movements were recorded and evaluated. Results Both intra-individual and inter-individual differences were detected in the M-mode traces during the 3 saliva swallows. Characteristic types were seen during the individual swallowing phases of M-mode traces: 2 activity types in phase I, 2 types in phase IIb, and 3 types in phase III. However, no variations were seen during phase IIa, in which all subjects displayed a continuous upsloping trace. The average range of swallow-related tongue radial displacement during phase IIa decreased gradually with age, while the average duration of tongue movement during phase IIa increased gradually with age. These 2 trends were not statistically significant across age groups. However, differences between sexes were found in both the range of tongue radial displacement and the duration of deglutitive lingual actions during phase IIa in all 3 age groups (P<0.05). Conclusions B+M-mode ultrasonography may offer a quick and safe alternative for the preliminary evaluation of deglutitive tongue movements. PMID:26049721

  10. Characterization of Single-mode Chalcogenide Optical Fiber for Mid-Infrared Applications

    SciTech Connect

    Krishnaswami, Kannan; Qiao, Hong; Bernacki, Bruce E.; Anheier, Norman C.

    2009-04-01

    Chalcogenide fibers display a wide transmission window ranging from 2-10.6 μm, ideally suited to the development of passive and active mid-infrared (MIR) sensors. They are essential building blocks for the integration and miniaturization of laser-based MIR optical systems for terrestrial, airborne and space-based sensing platforms. Single-mode chalcogenide fibers have only recently become commercially available and therefore performance data and standard reproducible processing techniques have not been widely reported. In this paper we present a method for producing high quality facets on commercial single-mode As-Se fibers with core and cladding diameters of 28.1 and 169.9μm respectively. The emitted beam profile from these fibers, using the 9.4μm line of a tunable CO2 laser, showed the presence of leaky cladding modes due to waveguiding conditions created by the protective acrylate jacket. These undesirable cladding modes were easily suppressed by applying a gallium coating on the cladding near both input and output facets. We provide experimental data of efficient mode suppression and the emission of a circular near-perfect Gaussian beam profile from the fiber. A model to determine appropriate placement of gallium coatings to minimize processing while maximizing cladding mode suppression is currently underway. Furthermore, analyses of the beam, acquired by scanning an HgCdTe detector, yielded a 1/e2 numerical aperture of 0.11 with a full width half maximum divergence of 11° for these fibers. The availability of single-mode MIR fibers, in conjunction with recent advances in room temperature quantum cascade lasers (QCL), could provide compact and light-weight transmitter solutions for several critical defense and nuclear non-proliferation needs.

  11. Optical whispering-gallery mode resonators for applications in optical communication and frequency control

    NASA Astrophysics Data System (ADS)

    Grutter, Karen Esther

    High quality factor (Q) optical whispering gallery mode resonators are a key component in many on-chip optical systems, such as delay lines, modulators, and add-drop filters. They are also a convenient, compact structure for studying optomechanical interactions on-chip. In all these applications, optical Q is an important factor for high performance. For optomechanical reference oscillators in particular, high mechanical Q is also necessary. Previously, optical microresonators have been made in a wide variety of materials, but it has proven challenging to demonstrate high optical Q and high mechanical Q in a single, integrated device. This work demonstrates a new technique for achieving high optical Q on chip, a fully-integrated tunable filter with ultra-narrow minimum bandwidth, and the effect of material choice and device design on optical Q, mechanical Q and phase noise in microring optomechanical oscillators. To achieve a high optical Q, phosphosilicate glass (PSG) is studied as a resonator material. The low melting point of PSG enables wafer-scale reflow, which reduces sidewall roughness without significantly changing lithographically-defined dimensions. With this process, optical Qs up to 1.5 x 10. 7 are achieved, overten times higher than typical silicon optical resonators. These high-Q PSG resonators are then integrated with MEMS-actuated waveguides in a tunable-bandwidth filter. Due to the high Q of the PSG resonator, this device has a best-to-date minimum bandwidth of 0.8 GHz, with a tuning range of 0.8 to 8.5GHz. Finally, microring optomechanical oscillators (OMOs) in PSG, stoichiometric silicon nitride, and silicon are fabricated, and their performance is compared after characterization via a tapered optical fiber in vacuum. The silicon nitride device has the best performance, with a mechanical Q of more than 1 x 10. 4and record-breaking OMO phase noise of -102 dBc/Hz at a 1 kHz offset from a 72 MHz carrier.

  12. WS₂ as a saturable absorber for ultrafast photonic applications of mode-locked and Q-switched lasers.

    PubMed

    Wu, Kan; Zhang, Xiaoyan; Wang, Jun; Li, Xing; Chen, Jianping

    2015-05-01

    Two-dimensional (2D) nanomaterials, especially the transition metal sulfide semiconductors, have drawn great interests due to their potential applications in viable photonic and optoelectronic devices. In this work, 2D tungsten disulfide (WS2) based saturable absorber (SA) for ultrafast photonic applications was demonstrated. WS2 nanosheets were prepared using liquid-phase exfoliation method and embedded in polyvinyl alcohol (PVA) thin film for the practical usage. Saturable absorption was discovered in the WS2-PVA SA at the telecommunication wavelength near 1550 nm. By incorporating WS2-PVA SA into a fiber laser cavity, both stable mode locking operation and Q-switching operation were achieved. In the mode locking operation, the laser obtained femtosecond output pulse width and high spectral purity in the radio frequency spectrum. In the Q-switching operation, the laser had tunable repetition rate and output pulse energy of a few tens of nano joule. Our findings suggest that few-layer WS2 nanosheets embedded in PVA thin film are promising nonlinear optical materials for ultrafast photonic applications as a mode locker or Q-switcher. PMID:25969240

  13. Measurement and reliability issues in resonant mode cantilever for bio-sensing application in fluid medium

    NASA Astrophysics Data System (ADS)

    Kathel, G.; Shajahan, M. S.; Bhadra, P.; Prabhakar, A.; Chadha, A.; Bhattacharya, E.

    2016-09-01

    Cantilevers immersed in liquid experience viscous damping and hydrodynamic loading. We report on the use of such cantilevers, operating in the dynamic mode with, (i) frequency sweeping and (ii) phase locked loop methods. The solution to reliability issues such as random drift in the resonant peak values, and interference of spurious modes in the resonance frequency spectrum, are explained based on the actuation signal provided and laser spot size. The laser beam spot size and its position on the cantilever were found to have an important role, on the output signal and resonance frequency. We describe a method to distinguish the normal modes from the spurious modes for a cantilever. Uncertainties in the measurements define the lower limit of mass detection (m min). The minimum detection limits of the two measurement methods are investigated by measuring salt adsorption from phosphate buffer solution, as an example, a mass of 14 pg was measured using the 14th transverse mode of a 500~μ m  ×  100 μm  ×  1 μm silicon cantilever. The optimized measurement was used to study the interaction between antibody and antigen.

  14. An r-mode in a magnetic rotating spherical layer: application to neutron stars

    NASA Astrophysics Data System (ADS)

    Abbassi, S.; Rieutord, M.; Rezania, V.

    2012-02-01

    The combined impact of rotation and magnetic fields on oscillations of stellar fluids is still not well known theoretically. It mixes Alfvén and inertial waves. Neutron stars are a place where both effects may be at work. We aim to solve this problem in the context of the r-mode instability in neutron stars, as it appears when these modes are coupled to gravitational radiation. We consider a rotating spherical shell filled with a viscous fluid of infinite electrical conductivity and analyse propagation of model perturbations when a dipolar magnetic field is bathing the fluid layer. We perform an extensive numerical analysis and find that the m= 2 r-mode oscillation is influenced by the magnetic field when the Lehnert number (the ratio of Alfvén speed to rotation speed) exceeds a value proportional to the one-fourth power of the Ekman number (a non-dimensional measure of viscosity). This scaling is interpreted as the coincidence of the width of internal shear layers of inertial modes and the wavelength of the Alfvén waves. Applied to the case of rotating magnetic neutron stars, we find that dipolar magnetic fields above 1014 G are necessary to perturb the r-mode instability.

  15. Performance comparison of Rayleigh and STW modes on quartz crystal for strain sensor application

    NASA Astrophysics Data System (ADS)

    Fu, Chen; Lee, Ki Jung; Eun, Kyongtae; Choa, Sung-Hoon; Lee, Keekeun; Yang, Sang Sik

    2016-07-01

    In this study, we compare two kinds of strain sensors based on Rayleigh wave and surface transverse wave (STW) modes, respectively. First, we perform a strain-and-stress analysis using the finite element method, and we consider the contribution to a surface acoustic wave (SAW) velocity shift. Prior to fabrication, we use a coupling-of-modes model to simulate and optimize two-port SAW resonators for both modes. We use a network analyzer to measure and characterize the two devices. Further, we perform an experiment using a strain-testing system with a tapered cross-section cantilever beam. The experimental results show that the ratio of the frequency shift to the strain for the Rayleigh wave mode is -1.124 ppm/μɛ in the parallel direction and 0.109 ppm/μɛ in the perpendicular direction, while the corresponding values for the STW mode are 0.680 ppm/μɛ and 0.189 ppm/μɛ, respectively.

  16. Application of failure mode and effect analysis in an assisted reproduction technology laboratory.

    PubMed

    Intra, Giulia; Alteri, Alessandra; Corti, Laura; Rabellotti, Elisa; Papaleo, Enrico; Restelli, Liliana; Biondo, Stefania; Garancini, Maria Paola; Candiani, Massimo; Viganò, Paola

    2016-08-01

    Assisted reproduction technology laboratories have a very high degree of complexity. Mismatches of gametes or embryos can occur, with catastrophic consequences for patients. To minimize the risk of error, a multi-institutional working group applied failure mode and effects analysis (FMEA) to each critical activity/step as a method of risk assessment. This analysis led to the identification of the potential failure modes, together with their causes and effects, using the risk priority number (RPN) scoring system. In total, 11 individual steps and 68 different potential failure modes were identified. The highest ranked failure modes, with an RPN score of 25, encompassed 17 failures and pertained to "patient mismatch" and "biological sample mismatch". The maximum reduction in risk, with RPN reduced from 25 to 5, was mostly related to the introduction of witnessing. The critical failure modes in sample processing were improved by 50% in the RPN by focusing on staff training. Three indicators of FMEA success, based on technical skill, competence and traceability, have been evaluated after FMEA implementation. Witnessing by a second human operator should be introduced in the laboratory to avoid sample mix-ups. These findings confirm that FMEA can effectively reduce errors in assisted reproduction technology laboratories. PMID:27282213

  17. Numerical Modeling of Normal-Mode Oscillations in Planetary Atmospheres: Application to Saturn and Titan

    NASA Astrophysics Data System (ADS)

    Friedson, Andrew James; Ding, Leon

    2015-11-01

    We have developed a numerical model to calculate the frequencies and eigenfunctions of adiabatic, non-radial normal-mode oscillations in the gas giants and Titan. The model solves the linearized momentum, energy, and continuity equations for the perturbation displacement, pressure, and density fields and solves Poisson’s equation for the perturbation gravitational potential. The response to effects associated with planetary rotation, including the Coriolis force, centrifugal force, and deformation of the equilibrium structure, is calculated numerically. This provides the capability to accurately compute the influence of rotation on the modes, even in the limit where mode frequency approaches the rotation rate, when analytical estimates based on functional perturbation analysis become inaccurate. This aspect of the model makes it ideal for studying the potential role of low-frequency modes for driving spiral density waves in the C ring that possess relatively low pattern speeds (Hedman, M.M and P.D. Nicholson, MNRAS 444, 1369-1388). In addition, the model can be used to explore the effect of internal differential rotation on the eigenfrequencies. We will (1) present examples of applying the model to calculate the properties of normal modes in Saturn and their relationship to observed spiral density waves in the C ring, and (2) discuss how the model is used to examine the response of the superrotating atmosphere of Titan to the gravitational tide exerted by Saturn. This research was supported by a grant from the NASA Planetary Atmosphere Program.

  18. The use of mindfulness in obsessive compulsive disorder: suggestions for its application and integration in existing treatment.

    PubMed

    Fairfax, Hamilton

    2008-01-01

    Treatment for obsessive-compulsive disorder (OCD) is a standard activity of psychologists, particularly those in Community Mental Health Teams (CMHT). In 2005, NICE published guidelines recommending Cognitive Behavioural Therapy (CBT) with Exposure and Response Prevention (ER-P) as the evidence-based psychological treatments of choice. In recent years there have been significant developments within cognitive behavioural theory, including what has been referred to as the 'Third Wave'. This paper explores the contribution of mindfulness; a practice that has previously been integrated into other CBT models of treatment, to cognitive interventions in OCD, suggesting that in complements both CBT and ER-However it had previously been suggested by Freeston that mindfulness may prevent successful ER-P by becoming a neutralising technique. Examples of the application of a mindfulness-based approach are explored (MOCD), including reference to an OCD group run by the author, and areas of potential overlap are identified, in particular thought-action Fusion. It is concluded that if applied properly, mindfulness not only complements traditional CBT interventions, but could also increase their efficacy and perhaps prevent relapse. PMID:19115428

  19. The application of low frequency longitudinal guided wave mode for the inspection of multi-hole steel floral pipes

    NASA Astrophysics Data System (ADS)

    Liu, Z. H.; Xie, X. D.; Wu, B.; Li, Y. H.; He, C. F.

    2012-03-01

    Shed-pipe grouting technology, an effective advanced supporting method, is often used in the excavation of soft strata. Steel floral pipes are one of the key load-carrying components of shed-pipe grouting supporting structures. Guided waves are a very attractive methodology to inspect multi-hole steel floral pipes as they offer long range inspection capability, mode and frequency tuning, and cost effectiveness. In this contribution, preliminary experiments are described for the inspection of steel floral pipes using a low frequency longitudinal guided wave mode, L(0,2). The relation between the number of grouting holes and the peak-to-peak amplitude of the first end-reflected signal was obtained. The effect of the grouting holes in steel floral pipes on the propagation velocity of the L(0,2) mode at 30 kHz was analyzed. Experimental results indicate that the typical grouting holes in steel floral pipe have no significant effect on the propagation of this mode. As a result, low frequency longitudinal guided wave modes have potential for the non-destructive long range inspection of multi-hole steel floral pipes. Furthermore, the propagation velocity of the investigated L(0,2) mode at 30 kHz decreases linearly with the increase of the number of grouting holes in a steel floral pipe. It is also noticeable that the effect of the grouting holes cumulates along with the increase in the number of grouting holes and subsequent increase in reflection times of longitudinal guided waves in the steel floral pipe. The application potential of the low frequency longitudinal guided wave technique for the inspection of embedded steel floral pipes is discussed.

  20. Image characterization by fractal descriptors in variational mode decomposition domain: Application to brain magnetic resonance

    NASA Astrophysics Data System (ADS)

    Lahmiri, Salim

    2016-08-01

    The main purpose of this work is to explore the usefulness of fractal descriptors estimated in multi-resolution domains to characterize biomedical digital image texture. In this regard, three multi-resolution techniques are considered: the well-known discrete wavelet transform (DWT) and the empirical mode decomposition (EMD), and; the newly introduced; variational mode decomposition mode (VMD). The original image is decomposed by the DWT, EMD, and VMD into different scales. Then, Fourier spectrum based fractal descriptors is estimated at specific scales and directions to characterize the image. The support vector machine (SVM) was used to perform supervised classification. The empirical study was applied to the problem of distinguishing between normal and abnormal brain magnetic resonance images (MRI) affected with Alzheimer disease (AD). Our results demonstrate that fractal descriptors estimated in VMD domain outperform those estimated in DWT and EMD domains; and also those directly estimated from the original image.

  1. Design and experiment of a cross-shaped mode converter for high-power microwave applications

    SciTech Connect

    Peng, Shengren Yuan, Chengwei; Zhong, Huihuang; Fan, Yuwei

    2013-12-15

    A compact mode converter, which is capable of converting a TM{sub 01} mode into a circularly polarized TE{sub 11} mode, was developed and experimentally studied with high-power microwaves. The converter, consisting of two turnstile junctions, is very short along the wave propagation direction, and therefore is suitable for designing compact and axially aligned high-power microwave radiation systems. In this paper, the principle of a converter working at 1.75 GHz is demonstrated, as well as the experimental results. The experimental and simulation results are in good agreement. At the center frequency, the conversion efficiency is more than 95%, the measured axial ratio is about 0.4 dB, and the power-handing capacity is excess of 1.9 GW.

  2. Triple-Mode Emission of Carbon Dots: Applications for Advanced Anti-Counterfeiting.

    PubMed

    Jiang, Kai; Zhang, Ling; Lu, Junfeng; Xu, Chunxiang; Cai, Congzhong; Lin, Hengwei

    2016-06-13

    Photoluminescence (PL), up-conversion PL (UCPL), and phosphorescence are three kinds of phenomena common to light-emitting materials, but it is very difficult to observe all of them simultaneously when they are derived from a single material at room temperature. For the first time, triple-mode emission (that is, PL, UCPL, and room temperature phosphorescence (RTP)) is reported, which relies on a composite of the luminescent carbon dots (CDs) prepared from m-phenylenediamine and poly(vinyl alcohol) (PVA). Moreover, the CDs-PVA aqueous dispersion is nearly colorless and demonstrates promise as a triple-mode emission ink in the field of advanced anti-counterfeiting. PMID:27135645

  3. Target tracking using range-only measurements: application to ISAR mode of Ingara radar

    NASA Astrophysics Data System (ADS)

    Ristic, Branko; Arulampalam, Sanjeev; McCarthy, James

    2001-11-01

    The problem is on-line target state estimation from range and range-rate measurements. The motivation for this work comes from the need to track a target in the ISAR mode of the DSTO Ingara Multi-Mode Radar during an extended data collection. The paper makes three main contributions. First, the theoretical Cramér-Rao bound for the performance of an unbiased range-only tracking algorithm is derived. Second, three algorithms are developed and compared to the theoretical bounds of performance. Third, the developed techniques are applied to real data collected in the recent trials with the Ingara radar.

  4. Development and applications of two computational procedures for determining the vibration modes of structural systems. [aircraft structures - aerospaceplanes

    NASA Technical Reports Server (NTRS)

    Kvaternik, R. G.

    1975-01-01

    Two computational procedures for analyzing complex structural systems for their natural modes and frequencies of vibration are presented. Both procedures are based on a substructures methodology and both employ the finite-element stiffness method to model the constituent substructures. The first procedure is a direct method based on solving the eigenvalue problem associated with a finite-element representation of the complete structure. The second procedure is a component-mode synthesis scheme in which the vibration modes of the complete structure are synthesized from modes of substructures into which the structure is divided. The analytical basis of the methods contains a combination of features which enhance the generality of the procedures. The computational procedures exhibit a unique utilitarian character with respect to the versatility, computational convenience, and ease of computer implementation. The computational procedures were implemented in two special-purpose computer programs. The results of the application of these programs to several structural configurations are shown and comparisons are made with experiment.

  5. Comparing Binding Modes of Analogous Fragments Using NMR in Fragment-Based Drug Design: Application to PRDX5

    PubMed Central

    Guichou, Jean-François; Cala, Olivier; Krimm, Isabelle

    2014-01-01

    Fragment-based drug design is one of the most promising approaches for discovering novel and potent inhibitors against therapeutic targets. The first step of the process consists of identifying fragments that bind the protein target. The determination of the fragment binding mode plays a major role in the selection of the fragment hits that will be processed into drug-like compounds. Comparing the binding modes of analogous fragments is a critical task, not only to identify specific interactions between the protein target and the fragment, but also to verify whether the binding mode is conserved or differs according to the fragment modification. While X-ray crystallography is the technique of choice, NMR methods are helpful when this fails. We show here how the ligand-observed saturation transfer difference (STD) experiment and the protein-observed 15N-HSQC experiment, two popular NMR screening experiments, can be used to compare the binding modes of analogous fragments. We discuss the application and limitations of these approaches based on STD-epitope mapping, chemical shift perturbation (CSP) calculation and comparative CSP sign analysis, using the human peroxiredoxin 5 as a protein model. PMID:25025339

  6. Application of shuttle EVA systems to payloads. Volume 1: EVA systems and operational modes description

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Descriptions of the EVA system baselined for the space shuttle program were provided, as well as a compendium of data on available EVA operational modes for payload and orbiter servicing. Operational concepts and techniques to accomplish representative EVA payload tasks are proposed. Some of the subjects discussed include: extravehicular mobility unit, remote manipulator system, airlock, EVA translation aids, restraints, workstations, tools and support equipment.

  7. Rigid Body Modes Influence On Microvibration Analysis-Application To Swarm

    NASA Astrophysics Data System (ADS)

    Laduree, G.; Fransen, S.; Baldesi, G.; Pflieger, I.

    2012-07-01

    Microvibrations are defined as low level mechanical disturbances affecting payload performance, generated by mobile parts or mechanism operating on-board the spacecraft, like momentum or reaction wheels, pointing mechanism, cryo-coolers or thrusters. The disturbances caused by these sources are transmitted through the spacecraft structure and excite modes of that structure or elements of the payload impacting its performance (e.g. Line of sight rotations inducing some image quality degradation). The dynamic interaction between these three elements (noise source, spacecraft structure and sensitive receiver) makes the microvibration prediction a delicate problem. Microvibration sources are generally of concern in the frequency range from a few Hz to 1000 Hz. However, in some specific cases, high stability at lower frequencies might be requested. This is the case of the SWARM mission, whose objectives are to provide the best ever survey of the geomagnetic field and its temporal evolution as well as supplementary information for studying the interaction of the magnetic field with other physical quantities describing the Earth system (e.g. ocean circulation). Among its instruments, SWARM is embarking a very sensitive 6-axis accelerometer in the low frequency range (10-8 m/s2 or rad/s2 between 10-4 and 0.1 Hz) located at its Centre of Gravity and an Absolute Scalar Magnetometer located at the tip of a boom far from the spacecraft body. The ASM performs its measurements by rotating an alternative magnetic field around its main axis thanks to a piezo-electric motor. This repeated disturbance might generate some pollution of the accelerometer science data. The objective of this work is to focus on the interaction of the rigid body mode calculation method with the elastic contribution of the normal modes excited by the noise source frequency content. It has indeed been reported in the past that NASTRAN Lanczos rigid body modes may lead to inaccurate rigid-body accelerations

  8. Application of the H-Mode, a Design and Interaction Concept for Highly Automated Vehicles, to Aircraft

    NASA Technical Reports Server (NTRS)

    Goodrich, Kenneth H.; Flemisch, Frank O.; Schutte, Paul C.; Williams, Ralph A.

    2006-01-01

    Driven by increased safety, efficiency, and airspace capacity, automation is playing an increasing role in aircraft operations. As aircraft become increasingly able to autonomously respond to a range of situations with performance surpassing human operators, we are compelled to look for new methods that help us understand their use and guide their design using new forms of automation and interaction. We propose a novel design metaphor to aid the conceptualization, design, and operation of highly-automated aircraft. Design metaphors transfer meaning from common experiences to less familiar applications or functions. A notable example is the "Desktop metaphor" for manipulating files on a computer. This paper describes a metaphor for highly automated vehicles known as the H-metaphor and a specific embodiment of the metaphor known as the H-mode as applied to aircraft. The fundamentals of the H-metaphor are reviewed followed by an overview of an exploratory usability study investigating human-automation interaction issues for a simple H-mode implementation. The envisioned application of the H-mode concept to aircraft is then described as are two planned evaluations.

  9. Low power low phase noise phase locked loop frequency synthesizer with fast locking mode for 2.4 GHz applications

    NASA Astrophysics Data System (ADS)

    Liu, Xiaodong; Feng, Peng; Liu, Liyuan; Wu, Nanjian

    2014-01-01

    We designed a low power low phase noise phase locked loop (PLL) frequency synthesizer for 2.4 GHz wireless communication applications. Current reusing technique and triple-well NMOS transistors are applied to reduce power consumption and improve phase noise performance of the voltage controlled oscillator (VCO), respectively. The synthesizer has a fast locking mode that uses frequency presetting technique to greatly shorten the locking time. The synthesizer was implemented in 0.18 µm CMOS process. The chip core area is 1.49 mm2. Measured results show that the output frequency tuning range is 2.16-2.55 GHz. The phase noise is -124.18 dBc/Hz at 1 MHz from a 2.4 GHz carrier. The power consumption is 4.98 mW and the locking time in fast locking mode is about 4 µs.

  10. Integrating Anatomic and Functional Dual-Mode Magnetic Resonance Imaging: Design and Applicability of a Bifunctional Contrast Agent.

    PubMed

    Ni, Dalong; Shen, Zhiwei; Zhang, Jiawen; Zhang, Chen; Wu, Renhua; Liu, Jianan; Yi, Meizhi; Wang, Jing; Yao, Zhenwei; Bu, Wenbo; Shi, Jianlin

    2016-03-22

    In recent decades, extensive attention has been paid to developing anatomic and functional imaging contrast agents that could provide a wealth of complementary bioimaging information. Among them, dual-mode nanoprobes that combine anatomic magnetic resonance imaging (MRI) with functional fluorescent imaging have been mostly used for separated imaging. However, the lack of a machine for simultaneous dual-mode imaging greatly limits further clinical application. One effective strategy is to rationally design MRI contrast agents that own both anatomic and functional MR imaging capability on a single MRI machine, which is highly attractive but remains a great challenge. Herein, ultrasmall NaGdF4@PLL nanodots (NDs) were developed as a novel class of MR contrast agent, which offers a high longitude relaxivity (6.42 mM(-1) s(-1)) for T1-weighted MRI and an excellent sensitive chemical exchange saturation transfer (CEST) effect for pH mapping (at +3.7 ppm). Further in vivo animal experiments show the feasibility of NaGdF4@PLL NDs as contrast agents for efficient kidney and brain tumor diagnosis and pH mapping, which will undoubtedly enhance the diagnosis accuracy and is beneficial for disease precaution and prognosis. Different from other complex dual-mode nanoprobes, the as-constructed NaGdF4@PLL NDs enable both anatomic and functional imaging on a single MR machine, which is a simple and cost-effective new approach to realize dual-mode MR imaging and holds great potential for future clinical application. PMID:26910513

  11. High power single-mode fiber laser and its application to metal and non-metal materials

    NASA Astrophysics Data System (ADS)

    Miyato, Taizo; Kayahara, Takashi; Fujisaki, Akira; Furukawa, Koichi; Matsushita, Masafumi; Muramatsu, Mayu; Harada, Yoshihisa; Niino, Hiroyuki

    2014-02-01

    The power level of Yb doped fiber lasers which operate in continuous wave mode has been increasing in recent years and various kinds of applications using high power single-mode fiber lasers that oscillate in 1microns wavelength range were reported. Single-mode fiber laser that has excellent beam quality of less than 1.1 M2 value with kW class average power can be focused to tens of microns diameters and its optical power density at the focus point is more than 1×108 W/cm2. In this power density range, the interaction between 1microns laser light and matter, not only metal materials but non-metal materials, is completely different from that of lower level. The power density initiates laser processing of copper that has relatively high reflectivity at this wavelength range among metals and alumina base plate with over 90% reflectivity. Other interesting material which can be processed by this energy level is carbon fiber reinforced plastics (CFRP). On the other hand, for industrial application and further processing investigation, modulation speed is one of the most important factors because that relates to processing speed and precise control of laser energy input to a material. In this paper, we report on the power dependence of some material processing of copper wafer welding, alumina base plate scribing, and CFRP cutting using single-mode fiber laser which is capable of over 1kW peak power operation and has rapid switching time below 5 micro seconds.

  12. Electron heating mode transition induced by ultra-high frequency in atmospheric microplasmas for biomedical applications

    SciTech Connect

    Kwon, H. C.; Won, I. H.; Lee, J. K.

    2012-04-30

    The electron heating mode transition induced by ultra-high frequency in atmospheric-pressure microplasmas was investigated using particle-in-cell simulation with a Monte Carlo collision. Interestingly, this discharge mode transition is accompanied by non-monotonic evolution of electron kinetics such as effective electron temperature, plasma density, and electron energy on the electrode. In this study, the highest flux of energetic electrons ({epsilon} > 4 eV) usable for tailoring the surface chemistry in atmospheric microplasmas is obtained at the specific frequency (400 MHz), where an optimal trade-off is established between the amplitude of sheath oscillations and the power coupled to electrons for sub-millimeter dimensions (200 {mu}m).

  13. Neuro-sliding mode control with its applications to seesaw systems.

    PubMed

    Tsai, Chun-Hsien; Chung, Hung-Yuan; Yu, Fang-Ming

    2004-01-01

    This paper proposes an approach of cooperative control that is based on the concept of combining neural networks and the methodology of sliding mode control (SMC). The main purpose is to eliminate the chattering phenomenon. Next, the system performance can be improved by using the method of SMC. In the present approach, two parallel Neural Networks are utilized to realize a neuro-sliding mode control (NSMC), where the equivalent control and the corrective control are the outputs of neural network 1 and neural network 2, respectively. Based on expressions of the SMC, the weight adaptations of neural network can be determined. Furthermore, the gradient descent method is used to minimize the control force so that the chattering phenomenon can be eliminated. Finally, experimental results are given to show the effectiveness and feasibility of the approach. PMID:15387253

  14. Failure mode diagram of rubble pile asteroids: Application to (25143) asteroid Itokawa

    NASA Astrophysics Data System (ADS)

    Hirabayashi, Masatoshi; Scheeres, Daniel J.

    2016-01-01

    Proposing a diagram which shows the variation in asteroidal failure as a function of a spin period, later called the failure mode diagram, this paper considers the failure modes and conditions of asteroid (25143) Itokawa. This diagram is useful to describe when and where failure occurs in an asteroid. Assuming that Itokawa is homogeneous, we use a plastic finite element code to obtain the diagram for this object. The results show that if the bulk cohesive strength is less than 0.1 Pa, Itokawa experiences compressional failure on the neck surface at the current spin period 12.1 hours. At a spin period shorter than 4.5 hours, tension across the neck causes this asteroid to split into two components. It is also found that if the breakup spin period is longer than 5.2 hours, their motion is bounded. This implies that once Itokawa splits, the components may escape from one another.

  15. Applications of the Lithium Focused Ion Beam: Nanoscale Electrochemistry and Microdisk Mode Imaging

    NASA Astrophysics Data System (ADS)

    McGehee, William; Takeuchi, Saya; Michels, Thomas; Oleshko, Vladimir; Aksyuk, Vladimir; Soles, Christopher; McClelland, Jabez; Center for Nanoscale Science; Technology at NIST Collaboration; Materials Measurement Laboratory at NIST Collaboration

    2016-05-01

    The NIST-developed lithium Focused-Ion-Beam (LiFIB) system creates a low-energy, picoampere-scale ion beam from a photoionized gas of laser-cooled atoms. The ion beam can be focused to a <30 nm spot and scanned across a sample. This enables imaging through collection of ion-induced secondary electrons (similar to SEM) as well as the ability to selectively deposit lithium-ions into nanoscale volumes in a material. We exploit this second ability of the LiFIB to selectively ''titrate'' lithium ions as a means of probing the optical modes in microdisk resonators as well as for exploring nanoscale, Li-ion electrochemistry in battery-relevant materials. We present an overview of both measurements, including imaging of the optical mode in a silicon microdisk and a comparison of FIB and electrochemical lithiation of tin.

  16. Application of TFTR diagnostics to study of limiter H-modes

    NASA Astrophysics Data System (ADS)

    Bush, C. E.; Schivell, J.; Taylor, G.; Bretz, N.; Cavallo, A.; Fredrickson, E.; Janos, A.; Mansfield, D. K.; McGuire, K.; Nazikian, R.; Park, H.; Ramsey, A. T.; Stratton, B.; Synakowski, E. J.

    1990-11-01

    Circular limiter H modes with centrally peaked density profiles have been obtained on TFTR. Diagnostics used to study these unique plasmas include arrays of Dα and C ii detectors, bolometers, and Mirnov coils; x-ray imaging, charge exchange recombination spectroscopy, ECE, microwave scattering systems, and a multichannel infrared interferometer. These diagnostics have special features which allow time and space-resolved measurements during the H-mode transition and during ELMs. Microwave scattering during the H phase shows a feature in the scattered spectrum which is consistent with a poloidal rotation in the electron diamagnetic drift direction. Mirnov coil data digitized at 2 MHz show an increase in high-frequency magnetic fluctuations (60-200 kHz) during an ELM, while ECE data show 20-30 μs intense emission spikes in the outer 15-20 cm of the plasma edge.

  17. Application of TFTR diagnostics to study of limiter H modes (abstract)

    NASA Astrophysics Data System (ADS)

    Bush, C. E.; Schivell, J.; Taylor, G.; Bretz, N.; Cavallo, A.; Fredrickson, E.; Janos, A.; Mansfield, D. K.; McGuire, K.; Nazikian, R.; Park, H.; Ramsey, A. T.; Stratton, B.; Synakowski, E. J.

    1990-10-01

    Circular limiter H modes with centrally peaked density profiles have been obtained on TFTR. Diagnostics used to study these unique plasmas include arrays of Dα and C ii detectors, bolometers, and Mirnov coils; x-ray imaging, charge exchange recombination spectroscopy, ECE, microwave scattering systems, and a multichannel infrared interferometer. These diagnostics have special features which allow time and space-resolved measurements during the H-mode transition and during ELMs. Microwave scattering during the H phase shows a feature in the scattered spectrum which is consistent with a poloidal rotation in the electron diamagnetic drift direction. Mirnov coil data digitized at 2 MHz show an increase in high-frequency magnetic fluctuations (60-200 kHz) during an ELM, while ECE data show 20-30 μs intense emission spikes in the outer 15-20 cm of the plasma edge.

  18. QUANTUM MODE-COUPLING THEORY: Formulation and Applications to Normal and Supercooled Quantum Liquids

    NASA Astrophysics Data System (ADS)

    Rabani, Eran; Reichman, David R.

    2005-05-01

    We review our recent efforts to formulate and study a mode-coupling approach to real-time dynamic fluctuations in quantum liquids. Comparison is made between the theory and recent neutron scattering experiments performed on liquid ortho-deuterium and para-hydrogen. We discuss extensions of the theory to supercooled and glassy states where quantum fluctuations compete with thermal fluctuations. Experimental scenarios for quantum glassy liquids are briefly discussed.

  19. System and methods for determining masking signals for applying empirical mode decomposition (EMD) and for demodulating intrinsic mode functions obtained from application of EMD

    DOEpatents

    Senroy, Nilanjan; Suryanarayanan, Siddharth

    2011-03-15

    A computer-implemented method of signal processing is provided. The method includes generating one or more masking signals based upon a computed Fourier transform of a received signal. The method further includes determining one or more intrinsic mode functions (IMFs) of the received signal by performing a masking-signal-based empirical mode decomposition (EMD) using the at least one masking signal.

  20. Plasmon modes of circular cylindrical double-layer graphene.

    PubMed

    Zhao, Tao; Hu, Min; Zhong, Renbin; Chen, Xiaoxing; Zhang, Ping; Gong, Sen; Zhang, Chao; Liu, Shenggang

    2016-09-01

    In this paper, a theoretical investigation on plasmon modes in a circular cylindrical double-layer graphene structure is presented. Due to the interlayer electromagnetic interaction, there exist two branches of plasmon modes, the optical plasmon mode and the acoustic plasmon mode. The characteristics of these two modes, such as mode pattern, effective mode index and propagation loss, are analyzed. The modal behaviors can be effectively tuned by changing the distance between two graphene layers, the chemical potential of graphene and the permittivity of interlayer dielectric. Importantly, the breakup of tradeoff between mode confinement and propagation loss is discovered in the distance-dependent modal behavior, which originates from the unique dispersion properties of a double-layer graphene system. As a consequence, both strong mode confinement and longer propagation length can be achieved. Our results may provide good opportunities for developing applications based on graphene plasmonics in circular cylindrical structure. PMID:27607651

  1. Application of discrete time sliding mode control to a spacecraft in 6DoF with parameter identification

    NASA Astrophysics Data System (ADS)

    Lincoln, N. K.; Veres, S. M.

    2010-11-01

    This article presents the application of two discrete-time sliding mode controllers, developed in conjunction with a potential function guidance method, to provide control in both position and attitude for a rigid, holonomic spacecraft body using thrusters only. Identification of mass and inertial matrix parameters is also included. Both controllers are demonstrated for their effectiveness under realistic actuator constraints. One of the controllers is also implemented on hardware in a representative 5 degrees of freedom (5DoF) testbed environment to show the practical performance of the methods.

  2. Elasto-plastic analysis of a mode I edge crack with application to a surface notch.

    NASA Technical Reports Server (NTRS)

    Francis, P. H.

    1971-01-01

    A finite element analysis has been undertaken of the mechanical state of a plate containing a crack subjected to mode I loading. Specifically, a localized, well-defined surface depression (dimple) previously observed on the back surface of plate specimens immediately behind the plane of the crack was examined. The approach taken is concerned with defining more precisely the dimpling behavior as a function of relative flaw depth and applied stress level, as well as the development of the plastic zone at the crack tip.

  3. Sliding Mode Control Technique: Application to a Four Rotors Mini-Flying Robot

    NASA Astrophysics Data System (ADS)

    Zemalache, K. M.; Tahar, M.; Omari, A.; Maaref, H.

    2009-03-01

    This paper presents the study of stabilization with motion planning of the four rotors mini-flying robot (helicopter with four rotors). The dynamic model involves four control inputs which are computed to stabilize the engine with predefined trajectories path. The tracking feedback controller is based on receding horizon point to point steering. It is clear that our device belongs to families of under-actuated systems. Our aim is to obtain control algorithms using the cascade sliding mode approach in order to stabilize the engine and to generate its trajectory.

  4. 10 kWe dual-mode space nuclear power system for military and scientific applications

    NASA Astrophysics Data System (ADS)

    Malloy, John; Westerman, Kurt; Rochow, Richard; Scoles, Stephen

    The Small Externally-fueled Heat Pipe Thermionic Reactor concept is used as the basis of a 10 kWe dual-mode space power system scheme that generates both arcjet propulsion system power and direct (hydrogen propellant-heating) thrust. This direct-thrust feature allows the nuclear-power system to move a payload from LEO to GEO in less than one month, using half as much propellant as a cryogenic-fuel chemical rocket. The nuclear reactor uses 36 thermionic heat-pipe modules, which produce electricity within the reactor and remove waste heat.

  5. Application of empirical mode decomposition with local linear quantile regression in financial time series forecasting.

    PubMed

    Jaber, Abobaker M; Ismail, Mohd Tahir; Altaher, Alsaidi M

    2014-01-01

    This paper mainly forecasts the daily closing price of stock markets. We propose a two-stage technique that combines the empirical mode decomposition (EMD) with nonparametric methods of local linear quantile (LLQ). We use the proposed technique, EMD-LLQ, to forecast two stock index time series. Detailed experiments are implemented for the proposed method, in which EMD-LPQ, EMD, and Holt-Winter methods are compared. The proposed EMD-LPQ model is determined to be superior to the EMD and Holt-Winter methods in predicting the stock closing prices. PMID:25140343

  6. Exploring the Frequency Stability Limits of Whispering Gallery Mode Resonators for Metrological Applications

    NASA Technical Reports Server (NTRS)

    Chembo, Yanne K.; Baumgartel, Lukas; Grudinin, Ivan; Strekalov, Dmitry; Thompson, Robert; Yu, Nan

    2012-01-01

    Whispering gallery mode resonators are attracting increasing interest as promising frequency reference cavities. Unlike commonly used Fabry-Perot cavities, however, they are filled with a bulk medium whose properties have a significant impact on the stability of its resonance frequencies. In this context that has to be reduced to a minimum. On the other hand, a small monolithic resonator provides opportunity for better stability against vibration and acceleration. this feature is essential when the cavity operates in a non-laboratory environment. In this paper, we report a case study for a crystalline resonator, and discuss the a pathway towards the inhibition of vibration-and acceleration-induced frequency fluctuations.

  7. Evanescent-wave coupled right angled buried waveguide: Applications in carbon nanotube mode-locking

    SciTech Connect

    Mary, R.; Thomson, R. R.; Kar, A. K.; Brown, G.; Popa, D.; Sun, Z.; Torrisi, F.; Hasan, T.; Milana, S.; Bonaccorso, F.; Ferrari, A. C.

    2013-11-25

    We present an evanescent-field device based on a right-angled waveguide. This consists of orthogonal waveguides, with their points of intersection lying along an angled facet of the chip. Light guided along one waveguide is incident at the angled dielectric-air facet at an angle exceeding the critical angle, so that the totally internally reflected light is coupled into the second waveguide. By depositing a nanotube film on the angled surface, the chip is then used to mode-lock an Erbium doped fiber ring laser with a repetition rate of 26 MHz, and pulse duration of 800 fs.

  8. Application of a laser/EMAT system for using shear and LS mode converted waves.

    PubMed

    Murray, P R; Dewhurst, R J

    2002-05-01

    Quantitative time-of-flight analysis of laser-generated shear waves and longitudinal-shear mode-converted waves has demonstrated an effective method for non-contact monitoring of the thickness of metal plates. Q-switched Nd:YAG laser pulses with energies of approximately 18 mJ, delivered to the material surface via an optical fibre and focused to a line source by a cylindrical lens, excited surface waves, longitudinal and shear waves. Bulk waves propagated through the plate to be reflected from the far surface. Returning waves were detected using an electro-magnetic acoustic transducer (EMAT) sensitive to in-plane motion. The compilation of B-scans generated as the sensor head was moved along the material's surface to produce a 2-D intensity profile made any changes in the plate thickness easy to visualise. The longitudinal-shear (L-S) and shear-longitudinal (S-L) mode-converted waves provided a method of simultaneously monitoring two different points on the far surface enabling any changes in the material thickness to be clearly identified. This method was used to determine the thickness of aluminium samples ranging in from 5 to 70 mm. PMID:12160043

  9. A coarse-grained normal mode approach for macromolecules: an efficient implementation and application to Ca(2+)-ATPase.

    PubMed Central

    Li, Guohui; Cui, Qiang

    2002-01-01

    A block normal mode (BNM) algorithm, originally proposed by Tama et al., (Proteins Struct. Func. Genet. 41:1-7, 2000) was implemented into the simulation program CHARMM. The BNM approach projects the hessian matrix into local translation/rotation basis vectors and, therefore, dramatically reduces the size of the matrix involved in diagonalization. In the current work, by constructing the atomic hessian elements required in the projection operation on the fly, the memory requirement for the BNM approach has been significantly reduced from that of standard normal mode analysis and previous implementation of BNM. As a result, low frequency modes, which are of interest in large-scale conformational changes of large proteins or protein-nucleic acid complexes, can be readily obtained. Comparison of the BNM results with standard normal mode analysis for a number of small proteins and nucleic acids indicates that many properties dominated by low frequency motions are well reproduced by BNM; these include atomic fluctuations, the displacement covariance matrix, vibrational entropies, and involvement coefficients for conformational transitions. Preliminary application to a fairly large system, Ca(2+)-ATPase (994 residues), is described as an example. The structural flexibility of the cytoplasmic domains (especially domain N), correlated motions among residues on domain interfaces and displacement patterns for the transmembrane helices observed in the BNM results are discussed in relation to the function of Ca(2+)-ATPase. The current implementation of the BNM approach has paved the way for developing efficient sampling algorithms with molecular dynamics or Monte Carlo for studying long-time scale dynamics of macromolecules. PMID:12414680

  10. Dynamic Theory of Relativistic Electrons Stochastic Heating by Whistler Mode Waves with Application to the Earth Magnetosphere

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Tel'nikhin, A. A.; Kronberg, T. K.

    2006-01-01

    In the Hamiltonian approach an electron motion in a coherent packet of the whistler mode waves propagating along the direction of an ambient magnetic field is studied. The physical processes by which these particles are accelerated to high energy are established. Equations governing a particle motion by group symmetries of the problem were transformed in to a closed pair of nonlinear difference equations. The solutions of these equations have shown there exists the energetic threshold below that the electron motion is regular, and when the initial energy is above the threshold an electron moves stochastically. It is proved that the upper boundary of particle stochastic heating is conditioned by intrinsic property of the particle chaotic motion. Particle energy spectra and pitch angle electron scattering are described by the Fokker-Planck-Kolmogorov equations. It is shown that significant pitch angle diffusion occurs for the Earth radiation belt electrons with energies from a few keV up to a few MeV.

  11. Theory of Raman scattering from Leggett's collective mode in a multiband superconductor: Application to MgB2

    NASA Astrophysics Data System (ADS)

    Klein, M. V.

    2010-07-01

    In 1966, Leggett used a two-band superconductor to show that a new collective mode could exist at low temperatures, corresponding to a counterflow of the superconducting condensates in each band. Here, the theory of electronic Raman scattering in a superconductor by Klein and Dierker (1984) is extended to a multiband superconductor. Raman scattering creates particle/hole (p/h) pairs. In the relevant A1g symmetry, the attraction that produces pairing necessarily couples excitations of superconducting pairs to these p/h excitations. In the Appendix, it is shown that for zero wave-vector transfer q , this coupling modifies the Raman response and makes the long-range Coulomb correction null. The two-band result is applied to MgB2 where this coupling activates Leggett’s collective mode. His simple limiting case is obtained when the interband attractive potential is decreased to a value well below that given by local-density approximation (LDA) theory. The peak from Leggett’s mode is studied as the potential is increased through the theoretical value. With realistic MgB2 parameters, the peak broadens through decay into the continuum above the smaller ( π band) superconducting gap. Finite q effects are also taken into account, yielding a Raman peak that agrees well in energy with the experimental result by Blumberg [Phys. Rev. Lett. 99, 227002 (2007)]10.1103/PhysRevLett.99.227002. This approach is also applied to the q=0 , two-band model of the Fe pnictides considered by Chubukov [Phys. Rev. B 79, 220501(R) (2009)]10.1103/PhysRevB.79.220501.

  12. On the sensitivity of protein data bank normal mode analysis: an application to GH10 xylanases

    NASA Astrophysics Data System (ADS)

    Tirion, Monique M.

    2015-12-01

    Protein data bank entries obtain distinct, reproducible flexibility characteristics determined by normal mode analyses of their three dimensional coordinate files. We study the effectiveness and sensitivity of this technique by analyzing the results on one class of glycosidases: family 10 xylanases. A conserved tryptophan that appears to affect access to the active site can be in one of two conformations according to x-ray crystallographic electron density data. The two alternate orientations of this active site tryptophan lead to distinct flexibility spectra, with one orientation thwarting the oscillations seen in the other. The particular orientation of this sidechain furthermore affects the appearance of the motility of a distant, C terminal region we term the mallet. The mallet region is known to separate members of this family of enzymes into two classes.

  13. Linear Mode HgCdTe Avalanche Photodiodes for Photon Counting Applications

    NASA Technical Reports Server (NTRS)

    Sullivan, William, III; Beck, Jeffrey; Scritchfield, Richard; Skokan, Mark; Mitra, Pradip; Sun, Xiaoli; Abshire, James; Carpenter, Darren; Lane, Barry

    2015-01-01

    An overview of recent improvements in the understanding and maturity of linear mode photon counting with HgCdTe electron-initiated avalanche photodiodes is presented. The first HgCdTe LMPC 2x8 format array fabricated in 2011 with 64 micron pitch was a remarkable success in terms of demonstrating a high single photon signal to noise ratio of 13.7 with an excess noise factor of 1.3-1.4, a 7 ns minimum time between events, and a broad spectral response extending from 0.4 micron to 4.2 micron. The main limitations were a greater than 10x higher false event rate than expected of greater than 1 MHz, a 5-7x lower than expected APD gain, and a photon detection efficiency of only 50% when greater than 60% was expected. This paper discusses the reasons behind these limitations and the implementation of their mitigations with new results.

  14. On the sensitivity of protein data bank normal mode analysis: an application to GH10 xylanases.

    PubMed

    Tirion, Monique M

    2015-01-01

    Protein data bank entries obtain distinct, reproducible flexibility characteristics determined by normal mode analyses of their three dimensional coordinate files. We study the effectiveness and sensitivity of this technique by analyzing the results on one class of glycosidases: family 10 xylanases. A conserved tryptophan that appears to affect access to the active site can be in one of two conformations according to x-ray crystallographic electron density data. The two alternate orientations of this active site tryptophan lead to distinct flexibility spectra, with one orientation thwarting the oscillations seen in the other. The particular orientation of this sidechain furthermore affects the appearance of the motility of a distant, C terminal region we term the mallet. The mallet region is known to separate members of this family of enzymes into two classes. PMID:26599799

  15. Mode-locking of acoustic resonators and its application to vibration cancellation in acoustic heat engines

    SciTech Connect

    Spoor, P.S.; Swift, G.W. )

    1999-09-01

    Vibration induced in engine hardware by a working fluid can be very significant in high-power, high-amplitude acoustic heat engines, and is a serious impediment to their practical use. This vibration can cause fatigue and destruction of engine components as well as fuel lines, cooling lines, and sensor wires. The forces involved make anchoring such an engine to an [open quotes]immovable[close quotes] object impractical. Rigidly attaching two such engines together, and acoustically coupling them with a duct of such a length and diameter that the two engines mode-lock in antiphase (thus canceling the longitudinal vibration) appears to be an inexpensive, viable solution. This paper describes in detail experiments demonstrating the feasibility of this idea, and the underlying theory. [copyright] [ital 1999 Acoustical Society of America.] < --[HEB] -->

  16. Adaptive-projection intrinsically transformed multivariate empirical mode decomposition in cooperative brain-computer interface applications.

    PubMed

    Hemakom, Apit; Goverdovsky, Valentin; Looney, David; Mandic, Danilo P

    2016-04-13

    An extension to multivariate empirical mode decomposition (MEMD), termed adaptive-projection intrinsically transformed MEMD (APIT-MEMD), is proposed to cater for power imbalances and inter-channel correlations in real-world multichannel data. It is shown that the APIT-MEMD exhibits similar or better performance than MEMD for a large number of projection vectors, whereas it outperforms MEMD for the critical case of a small number of projection vectors within the sifting algorithm. We also employ the noise-assisted APIT-MEMD within our proposed intrinsic multiscale analysis framework and illustrate the advantages of such an approach in notoriously noise-dominated cooperative brain-computer interface (BCI) based on the steady-state visual evoked potentials and the P300 responses. Finally, we show that for a joint cognitive BCI task, the proposed intrinsic multiscale analysis framework improves system performance in terms of the information transfer rate. PMID:26953174

  17. Improvements in mode-based waveform modeling and application to Eurasian velocity structure

    NASA Astrophysics Data System (ADS)

    Panning, M. P.; Marone, F.; Kim, A.; Capdeville, Y.; Cupillard, P.; Gung, Y.; Romanowicz, B.

    2006-12-01

    We introduce several recent improvements to mode-based 3D and asymptotic waveform modeling and examine how to integrate them with numerical approaches for an improved model of upper-mantle structure under eastern Eurasia. The first step in our approach is to create a large-scale starting model including shear anisotropy using Nonlinear Asymptotic Coupling Theory (NACT; Li and Romanowicz, 1995), which models the 2D sensitivity of the waveform to the great-circle path between source and receiver. We have recently improved this approach by implementing new crustal corrections which include a non-linear correction for the difference between the average structure of several large regions from the global model with further linear corrections to account for the local structure along the path between source and receiver (Marone and Romanowicz, 2006; Panning and Romanowicz, 2006). This model is further refined using a 3D implementation of Born scattering (Capdeville, 2005). We have made several recent improvements to this method, in particular introducing the ability to represent perturbations to discontinuities. While the approach treats all sensitivity as linear perturbations to the waveform, we have also experimented with a non-linear modification analogous to that used in the development of NACT. This allows us to treat large accumulated phase delays determined from a path-average approximation non-linearly, while still using the full 3D sensitivity of the Born approximation. Further refinement of shallow regions of the model is obtained using broadband forward finite-difference waveform modeling. We are also integrating a regional Spectral Element Method code into our tomographic modeling, allowing us to move beyond many assumptions inherent in the analytic mode-based approaches, while still taking advantage of their computational efficiency. Illustrations of the effects of these increasingly sophisticated steps will be presented.

  18. A comparative study between SMS interferometers and lossy mode resonace optical fiber devices for sensing applications

    NASA Astrophysics Data System (ADS)

    Socorro, A. B.; Hernaez, M.; Del Villar, I.; Corres, J. M.; Arregui, F. J.; Matias, I. R.

    2015-05-01

    Optical fiber sensors are of great interest due to their intrinsic advantages over electronic sensors. In this work, the sensing characteristics of two different and novel optical fiber devices are compared, after simultaneously depositing a thin-film using the layer-by-layer assembly deposition process. The first one is an SMS structure, formed by splicing two single-mode fiber pigtails on both sides of a coreless multimode fiber segment. This structure induces an interferometric phenomenon that generates several attenuation and transmission bands along the spectrum. These bands are sensitive to variations in the surrounding refractive index, although this sensitivity has been enhanced by a TiO2/PSS thin-film. The other device is a 40 mm uncladded segment of a 200 μm-core multimode optical fiber. When coated by a TiO2/PSS thinfilm, part of the light transmitted into the uncladded core is coupled into the thin-film, generating a lossy mode resonance (LMR). The absorption peaks due to these phenomena red-shift as long as the thin-film thickness increases or the external RI becomes higher. The performance of these devices as refractometers and relative humidity sensors are tested. Results show that the LMR-based sensor is more sensitive in both situations, in spite of its lower sensitivity. Particularly, it presents a 7-fold sensitivity enhancement when measuring surrounding medium refractive index changes and a 10-fold sensitivity enhancement when measuring environmental relative humidity. To our knowledge, this is the first time that a comparative study between SMS and LMR sensors is performed.

  19. Theory of Raman Scattering from Leggett's Collective Mode in a Multiple Band Superconductor: Application to MgB2

    NASA Astrophysics Data System (ADS)

    Klein, Miles

    2008-03-01

    Using an extension of BCS theory to a two-band superconductor, Leggett showed that if the relevant parameters obeyed certain conditions a collective mode would exist corresponding to the counter flow of the two condensates.^1 I have extended earlier work on electronic Raman in superconductors^2 to the multiple band case in order to incorporate Leggett's theory. The following effects have been included: (a) Vertex correction in the particle/hole channel where the Raman vertex acts. (b) Realistic parameters that apply to MgB2 yielding a counter flow mode that decays into the pair-breaking continuum associated with the lower gap π band. (c) Large finite wave-vector effects due to the relatively large Fermi velocity of the π band. (d) Integration over the wave-vector in part (c) necessitated by the exponential decay of the photon fields traveling into and out of the metallic sample. A comparison to the results of Blumberg^3 will be given. ^1A.J. Leggett, Progr. Theor. Phys. 36, 901 (1966). ^2M.V. Klein and S.B. Dierker, Phys. Rev. B29, 4976 (1984). ^3G. Blumberg et al., Phys. Rev. Lett. 99, (2007); arXiv:0710.2803.

  20. Dynamic theory of relativistic electrons stochastic heating by whistler mode waves with application to the Earth magnetosphere

    NASA Astrophysics Data System (ADS)

    Khazanov, G. V.; Tel'Nikhin, A. A.; Kronberg, T. K.

    2008-03-01

    In the Hamiltonian approach, electron motion in a coherent packet of the whistler mode waves propagating along the direction of an ambient magnetic field is studied. The physical processes by which these particles are accelerated to high energy are established. Equations governing particle motion are transformed into a closed pair of nonlinear difference equations. The solutions of these equations show there exists a threshold in initial electron energy, below which electron motion is regular and above which electron motion is stochastic. Particle energy spectra and pitch angle electron scattering are described by the Fokker-Planck-Kolmogorov equations. A calculation of the stochastic diffusion of electrons due to a spectrum of whistler modes is presented. The parametric dependence of the diffusion coefficients on the plasma particle density, magnitude of wave field, and the strength of magnetic field is studied. It is shown that significant pitch angle diffusion occurs for the Earth radiation belt electrons with energies from a few keV up to a few MeV.

  1. Dynamic Theory of Relativistic Electrons Stochastic Heating by Whistler Mode Waves with Application to the Earth Magnetosphere

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Tel'nikhin, A. A.; Kronberg, T. K.

    2007-01-01

    In the Hamiltonian approach an electron motion in a coherent packet of the whistler mode waves propagating along the direction of an ambient magnetic field is studied. The physical processes by which these particles are accelerated to high energy are established. Equations governing a particle motion were transformed in to a closed pair of nonlinear difference equations. The solutions of these equations have shown there exists the energetic threshold below that the electron motion is regular, and when the initial energy is above the threshold an electron moves stochastically. Particle energy spectra and pitch angle electron scattering are described by the Fokker-Planck-Kolmogorov equations. Calculating the stochastic diffusion of electrons due to a spectrum of whistler modes is presented. The parametric dependence of the diffusion coefficients on the plasma particle density, magnitude of wave field, and the strength of magnetic field is studies. It is shown that significant pitch angle diffusion occurs for the Earth radiation belt electrons with energies from a few keV up to a few MeV.

  2. A model for the multiplex dynamics of two-mode and one-mode networks, with an application to employment preference, friendship, and advice.

    PubMed

    Snijders, Tom A B; Lomi, Alessandro; Torló, Vanina Jasmine

    2013-05-01

    We propose a new stochastic actor-oriented model for the co-evolution of two-mode and one-mode networks. The model posits that activities of a set of actors, represented in the two-mode network, co-evolve with exchanges and interactions between the actors, as represented in the one-mode network. The model assumes that the actors, not the activities, have agency. The empirical value of the model is demonstrated by examining how employment preferences co-evolve with friendship and advice relations in a group of seventy-five MBA students. The analysis shows that activity in the two-mode network, as expressed by number of employment preferences, is related to activity in the friendship network, as expressed by outdegrees. Further, advice ties between students lead to agreement with respect to employment preferences. In addition, considering the multiplexity of advice and friendship ties yields a better understanding of the dynamics of the advice relation: tendencies to reciprocation and homophily in advice relations are mediated to an important extent by friendship relations. The discussion pays attention to the implications of this study in the broader context of current efforts to model the co-evolutionary dynamics of social networks and individual behavior. PMID:23690653

  3. Evaluation of the applicability of existing nuclear power plant regulatory requirements in the U.S. to advanced small modular reactors.

    SciTech Connect

    LaChance, Jeffrey L.; Wheeler, Timothy A.; Farnum, Cathy Ottinger; Middleton, Bobby D.; Jordan, Sabina Erteza; Duran, Felicia Angelica; Baum, Gregory A.

    2013-05-01

    The current wave of small modular reactor (SMR) designs all have the goal of reducing the cost of management and operations. By optimizing the system, the goal is to make these power plants safer, cheaper to operate and maintain, and more secure. In particular, the reduction in plant staffing can result in significant cost savings. The introduction of advanced reactor designs and increased use of advanced automation technologies in existing nuclear power plants will likely change the roles, responsibilities, composition, and size of the crews required to control plant operations. Similarly, certain security staffing requirements for traditional operational nuclear power plants may not be appropriate or necessary for SMRs due to the simpler, safer and more automated design characteristics of SMRs. As a first step in a process to identify where regulatory requirements may be met with reduced staffing and therefore lower cost, this report identifies the regulatory requirements and associated guidance utilized in the licensing of existing reactors. The potential applicability of these regulations to advanced SMR designs is identified taking into account the unique features of these types of reactors.

  4. Application of ISO 22000 and Failure Mode and Effect Analysis (FMEA) for industrial processing of salmon: a case study.

    PubMed

    Arvanitoyannis, Ioannis S; Varzakas, Theodoros H

    2008-05-01

    The Failure Mode and Effect Analysis (FMEA) model was applied for risk assessment of salmon manufacturing. A tentative approach of FMEA application to the salmon industry was attempted in conjunction with ISO 22000. Preliminary Hazard Analysis was used to analyze and predict the occurring failure modes in a food chain system (salmon processing plant), based on the functions, characteristics, and/or interactions of the ingredients or the processes, upon which the system depends. Critical Control points were identified and implemented in the cause and effect diagram (also known as Ishikawa, tree diagram and fishbone diagram). In this work, a comparison of ISO 22000 analysis with HACCP is carried out over salmon processing and packaging. However, the main emphasis was put on the quantification of risk assessment by determining the RPN per identified processing hazard. Fish receiving, casing/marking, blood removal, evisceration, filet-making cooling/freezing, and distribution were the processes identified as the ones with the highest RPN (252, 240, 210, 210, 210, 210, 200 respectively) and corrective actions were undertaken. After the application of corrective actions, a second calculation of RPN values was carried out resulting in substantially lower values (below the upper acceptable limit of 130). It is noteworthy that the application of Ishikawa (Cause and Effect or Tree diagram) led to converging results thus corroborating the validity of conclusions derived from risk assessment and FMEA. Therefore, the incorporation of FMEA analysis within the ISO 22000 system of a salmon processing industry is anticipated to prove advantageous to industrialists, state food inspectors, and consumers. PMID:18464031

  5. Phase conjugation of mode scrambled optical beams Application to spatial recovery and interbeam temporal information exchange

    NASA Astrophysics Data System (ADS)

    Yahalom, Ram; Kyuma, Kazuo; Yariv, Amnon

    1987-03-01

    Coupling of temporal information between two beams is demonstrated using a combination of a multimode fiber and a photorefractive passive phase conjugation mirror. It is shown that the polarization and spatial properties are fully recovered but temporal information is exchanged. The theoretical explanation for these phenomena and possible applications are discussed.

  6. Application of the J integral to fracture under mixed-mode loading. [MMJINT; 4330V steel

    SciTech Connect

    Riddle, R.A.

    1981-06-01

    The calculation of the J integral proved to be a successful method for characterizing the stress and displacement fields around a crack tip under mixed mode loading. A computer program was written to determine the symmetric and antisymmetric J integral quantities. The stress intensity factors from these J integral calculations were in excellent agreement with other calculations. The compact shear specimen used contains three loading holes, the load applied at the center hole being the opposite direction to the load applied at the two outer holes. For 7075-T6 aluminum, K/sub IIc/ was 1.9 times larger than K/sub Ic/. In the brittle photoelastic material K/sub IIc/ was less than K/sub Ic/. Failure of the 4330V steel compact shear specimens came as a result of the average shear stress in the region ahead of the crack tip exceeding the material flow shear stress. The experimental results suggest that the angle of crack growth is best predicted by the maximum tangential stress theory.

  7. A low power dual-band multi-mode RF front-end for GNSS applications

    NASA Astrophysics Data System (ADS)

    Hao, Zhang; Zhiqun, Li; Zhigong, Wang

    2010-11-01

    A CMOS dual-band multi-mode RF front-end for the global navigation satellite system receivers of all GPS, Bei-Dou, Galileo and Glonass systems is presented. It consists of a reconfigurable low noise amplifier (LNA), a broadband active balun, a high linearity mixer and a bandgap reference (BGR) circuit. The effect of the input parasitic capacitance on the input impedance of the inductively degenerated common source LNA is analyzed in detail. By using two different LC networks at the input port and the switched capacitor at the output port, the LNA can work at two different frequency bands (1.2 GHz and 1.5 GHz) under low power consumption. The active balun uses a hybrid-connection structure to achieve high bandwidth. The mixer uses the multiple gated transistors technique to acquire a high linearity under low power consumption but does not deteriorate other performances. The measurement results of the proposed front-end achieve a noise figure of 2.1/2.0 dB, again of 33.9/33.8 dB and an input 1-dB compression point of 0/1 dBm at 1227.6/1575.42 MHz. The power consumption is about 16 mW under a 1.8 V power supply.

  8. Development and Application of Benchmark Examples for Mode II Static Delamination Propagation and Fatigue Growth Predictions

    NASA Technical Reports Server (NTRS)

    Krueger, Ronald

    2011-01-01

    The development of benchmark examples for static delamination propagation and cyclic delamination onset and growth prediction is presented and demonstrated for a commercial code. The example is based on a finite element model of an End-Notched Flexure (ENF) specimen. The example is independent of the analysis software used and allows the assessment of the automated delamination propagation, onset and growth prediction capabilities in commercial finite element codes based on the virtual crack closure technique (VCCT). First, static benchmark examples were created for the specimen. Second, based on the static results, benchmark examples for cyclic delamination growth were created. Third, the load-displacement relationship from a propagation analysis and the benchmark results were compared, and good agreement could be achieved by selecting the appropriate input parameters. Fourth, starting from an initially straight front, the delamination was allowed to grow under cyclic loading. The number of cycles to delamination onset and the number of cycles during delamination growth for each growth increment were obtained from the automated analysis and compared to the benchmark examples. Again, good agreement between the results obtained from the growth analysis and the benchmark results could be achieved by selecting the appropriate input parameters. The benchmarking procedure proved valuable by highlighting the issues associated with choosing the input parameters of the particular implementation. Selecting the appropriate input parameters, however, was not straightforward and often required an iterative procedure. Overall the results are encouraging, but further assessment for mixed-mode delamination is required.

  9. Application of positive mode atmospheric chemical ionisation to distinguish epimeric oleanolic and ursolic acids.

    PubMed

    Townley, Chloe; Brettell, Rhea C; Bowen, Richard D; Gallagher, Richard T; Martin, William H C

    2015-01-01

    A new and more reliable method is reported for distinguishing the equatorial and axial epimers of oleanolic and ursolic acids and related triterpenoids based primarily on the relative abundance of the [M+H](+) and [M+-H(2)O](+) signals in their positive mode atmospheric pressure chemical ionisation mass spectra. The rate of elimination of water, which is the principal primary fragmentation of protonated oleanolic and ursolic acids, depends systematically on the stereochemistry of the hydroxyl group in the 3 position. For the b-epimer, in which the 3-hydroxyl substituent is in an equatorial position,[M+-H(2)O](+) is the base peak. In contrast, for the α-epimer, where the 3-hydroxyl group is axial, [M + H](+) is the base peak. This trend, which is general for a range of derivatives of oleanolic and ursolic acids, including the corresponding methyl esters, allows epimeric triterpenoids in these series to be securely differentiated. Confirmatory information is available from the collision-induced dissociation of the [M+-H(2)O](+) primary fragment ions, which follow different pathways for the species derived from axial and equatorial epimers of oleanolic and ursolic acids. These two pieces of independent spectral information permit the stereochemistry of epimeric oleanolic and ursolic acids (and selected derivatives) to be assigned with confidence without relying either on chromatographic retention times or referring to the spectra or other properties of authentic samples of these triterpenoids. PMID:26307724

  10. Mode II fatigue crack propagation.

    NASA Technical Reports Server (NTRS)

    Roberts, R.; Kibler, J. J.

    1971-01-01

    Fatigue crack propagation rates were obtained for 2024-T3 bare aluminum plates subjected to in-plane, mode I, extensional loads and transverse, mode II, bending loads. These results were compared to the results of Iida and Kobayashi for in-plane mode I-mode II extensional loads. The engineering significance of mode I-mode II fatigue crack growth is considered in view of the present results. A fatigue crack growth equation for handling mode I-mode II fatigue crack growth rates from existing mode I data is also discussed.

  11. Mode identification using stochastic hybrid models with applications to conflict detection and resolution

    NASA Astrophysics Data System (ADS)

    Naseri Kouzehgarani, Asal

    2009-12-01

    Most models of aircraft trajectories are non-linear and stochastic in nature; and their internal parameters are often poorly defined. The ability to model, simulate and analyze realistic air traffic management conflict detection scenarios in a scalable, composable, multi-aircraft fashion is an extremely difficult endeavor. Accurate techniques for aircraft mode detection are critical in order to enable the precise projection of aircraft conflicts, and for the enactment of altitude separation resolution strategies. Conflict detection is an inherently probabilistic endeavor; our ability to detect conflicts in a timely and accurate manner over a fixed time horizon is traded off against the increased human workload created by false alarms---that is, situations that would not develop into an actual conflict, or would resolve naturally in the appropriate time horizon-thereby introducing a measure of probabilistic uncertainty in any decision aid fashioned to assist air traffic controllers. The interaction of the continuous dynamics of the aircraft, used for prediction purposes, with the discrete conflict detection logic gives rise to the hybrid nature of the overall system. The introduction of the probabilistic element, common to decision alerting and aiding devices, places the conflict detection and resolution problem in the domain of probabilistic hybrid phenomena. A hidden Markov model (HMM) has two stochastic components: a finite-state Markov chain and a finite set of output probability distributions. In other words an unobservable stochastic process (hidden) that can only be observed through another set of stochastic processes that generate the sequence of observations. The problem of self separation in distributed air traffic management reduces to the ability of aircraft to communicate state information to neighboring aircraft, as well as model the evolution of aircraft trajectories between communications, in the presence of probabilistic uncertain dynamics as well

  12. Diode laser interrogated single-mode fiber optics with a hetero-core structure for a wearable glove sensing application

    NASA Astrophysics Data System (ADS)

    Nishiyama, M.; Sasaki, H.; Kubota, Y.; Watanabe, K.

    2008-10-01

    We have developed hetero-core fiber techniques interrogated with a semiconductor diode laser based on single-mode transmission for wearable glove sensing applications. The hetero-core fiber sensor is suitable for the wearable sensing glove because of the advantages of the capable optical intensity-based measurement with the excellent stability of the usage of the single-mode transmission fiber and independence of temperature fluctuation. In order that the hetero-core sensor was unaffected to the random wrinkles at the position of joints in a glove garment, the hetero-core sensor elements were located in the back of hand. As a result, the hetero-core flexion sensor could detect the joint angle of fingers regardless of differences of their size of hands, and the hetero-core sensing technique enables the sensing glove to equip the minimum number of sensors. The optical loss performances of the hetero-core sensors have indicated monotonic characteristics with the flexion angle of joints. The optical loss change is 1.35 dB for the flexion angle of approximately 97.2 degrees with accuracy of detectable flexion angle of 0.84 degree. Real-time hand motion capturing was successfully demonstrated by means of the proposed wearable sensing glove with hetero-core fiber techniques without restricting human natural behaviors.

  13. Classification, mode of action and production strategy of xylanase and its application for biofuel production from water hyacinth.

    PubMed

    Uday, Uma Shankar Prasad; Choudhury, Payel; Bandyopadhyay, Tarun Kanti; Bhunia, Biswanath

    2016-01-01

    Xylanases are classified under glycoside hydrolase families which represent one of the largest groups of commercial enzymes. Depolymerizing xylan molecules into monomeric pentose units involves the synergistic action of mainly two key enzymes which are endo-β-xylanase and β-xylosidase. Xylanases are different with respect to their mode of action, substrate specificities, biochemical properties, 3D structure and are widely produced by a spectrum of bacteria and fungi. Currently, large scale production of xylanase can be produced through the application of genetic engineering tool which allow fast identification of novel xylanase genes and their genetic variations makes it an ideal enzymes. Due to depletion of fossil fuel, there is urgent need to find out environment friendly and sustainable energy sources. Therefore, utilisation of cheap lignocellulosic materials along with proper optimisation of process is most important for cost efficient ethanol production. Among, various types of lignocellulosic substances, water hyacinth, a noxious aquatic weed, has been found in many tropical. Therefore, the technological development for biofuel production from water hyacinth is becoming commercially worthwhile. In this review, the classification and mode of action of xylanase including genetic regulation and strategy for robust xylanase production have been critically discussed from recent reports. In addition various strategies for cost effective biofuel production from water hyacinth including chimeric proteins design has also been critically evaluated. PMID:26529189

  14. Lock-in common-mode rejection demodulation: Measurement technique and applications to thermal-wave detection. Experimental

    NASA Astrophysics Data System (ADS)

    Paoloni, Stefano; Nicolaides, Lena; Mandelis, Andreas

    2000-06-01

    A new signal generation methodology based on lock-in amplifier common mode rejection demodulation for materials nondestructive evaluation has been implemented experimentally with thermal waves in a photothermal radiometric apparatus. A procedure to calibrate the experiment is described in order to take into account instrumental time delay phase shifts between the reference and the optical excitation wave form. Some preliminary results obtained on Zr-2.5Nb shot peened samples are presented and compared to those obtained by temporally modulating the pump intensity as a 50% duty cycle square wave. The comparison shows the new measurement methodology to be a very promising technique for nondestructive evaluation and depth profiling applications, featuring high detectivity for low-dynamic-range and poor-signal to noise ratio signals, such as those obtained with thermal-wave diagnostics.

  15. Raman-pumped Fourier-domain mode-locked laser: analysis of operation and application for optical coherence tomography.

    PubMed

    Klein, Thomas; Wieser, Wolfgang; Biedermann, Benjamin R; Eigenwillig, Christoph M; Palte, Gesa; Huber, Robert

    2008-12-01

    We demonstrate a Raman-pumped Fourier-domain mode-locked (FDML) fiber laser and optical coherence tomography imaging with this source. The wavelength sweep range of only 30 nm centered around 1550 nm results in limited axial resolution, hence a nonbiological sample is imaged. An output power of 1.9 mW was achieved at a sweep rate of 66 kHz and a maximum ranging depth of ~2.5 cm. Roll-off characteristics are found to be similar to FDML lasers with semiconductor optical amplifiers as gain media. The application of Raman gain also enables unperturbed cavity ring-down experiments in FDML lasers for the first time, providing direct access to the photon lifetime in the laser cavity. Good agreement with nonswept cw operation is proof of the stationary operation of FDML lasers. PMID:19037436

  16. Application of Tapping-Mode Scanning Probe Electrospray Ionization to Mass Spectrometry Imaging of Additives in Polymer Films

    PubMed Central

    Shimazu, Ryo; Yamoto, Yoshinari; Kosaka, Tomoya; Kawasaki, Hideya; Arakawa, Ryuichi

    2014-01-01

    We report the application of tapping-mode scanning probe electrospray ionization (t-SPESI) to mass spectrometry imaging of industrial materials. The t-SPESI parameters including tapping solvent composition, solvent flow rate, number of tapping at each spot, and step-size were optimized using a quadrupole mass spectrometer to improve mass spectrometry (MS) imaging of thin-layer chromatography (TLC) and additives in polymer films. Spatial resolution of approximately 100 μm was achieved by t-SPESI imaging mass spectrometry using a fused-silica capillary (50 μm i.d., 150 μm o.d.) with the flow rate set at 0.2 μL/min. This allowed us to obtain discriminable MS imaging profiles of three dyes separated by TLC and the additive stripe pattern of a PMMA model film depleted by UV irradiation. PMID:26819894

  17. Building Shared Experience to Advance Practical Application of Pathway-Based Toxicology: Liver Toxicity Mode-of-Action

    PubMed Central

    Willett, Catherine; Rae, Jessica Caverly; Goyak, Katy O.; Minsavage, Gary; Westmoreland, Carl; Andersen, Melvin; Avigan, Mark; Duché, Daniel; Harris, Georgina; Hartung, Thomas; Jaeschke, Hartmut; Kleensang, Andre; Landesmann, Brigitte; Martos, Suzanne; Matevia, Marilyn; Toole, Colleen; Rowan, Andrew; Schultz, Terry; Seed, Jennifer; Senior, John; Shah, Imran; Subramanian, Kalyanasundaram; Vinken, Mathieu; Watkins, Paul

    2016-01-01

    Summary A workshop sponsored by the Human Toxicology Project Consortium (HTPC), “Building Shared Experience to Advance Practical Application of Pathway-Based Toxicology: Liver Toxicity Mode-of-Action” brought together experts from a wide range of perspectives to inform the process of pathway development and to advance two prototype pathways initially developed by the European Commission Joint Research Center (JRC): liver-specific fibrosis and steatosis. The first half of the workshop focused on the theory and practice of pathway development; the second on liver disease and the two prototype pathways. Participants agreed pathway development is extremely useful for organizing information and found that focusing the theoretical discussion on a specific AOP is helpful. It is important to include several perspectives during pathway development, including information specialists, pathologists, human health and environmental risk assessors, and chemical and product manufacturers, to ensure the biology is well captured and end use is considered. PMID:24535319

  18. Leaky-mode assisted fluorescence extraction: application to fluorescence enhancement biosensors.

    PubMed

    Ganesh, Nikhil; Block, Ian D; Mathias, Patrick C; Zhang, Wei; Chow, Edmond; Malyarchuk, Viktor; Cunningham, Brian T

    2008-12-22

    Efficient recovery of light emitted by fluorescent molecules by employing photonic structures can result in high signal-to-noise ratio detection for biological applications including DNA microarrays, fluorescence microscopy and single molecule detection. By employing a model system comprised of colloidal quantum dots, we consider the physical basis of the extraction effect as provided by photonic crystals. Devices with different lattice symmetry are fabricated ensuring spectral and spatial coupling of quantum dot emission with leaky eigenmodes and the emission characteristics are studied using angle-resolved and angle-integrated measurements. Comparison with numerical calculations and lifetime measurements reveals that the enhancement occurs via resonant redirection of the emitted radiation. Comparison of various lattices reveals differences in the enhancement factor with a maximum enhancement factor approaching 220. We also demonstrate the first enhanced extraction biosensor that allows for over 20-fold enhancement of the fluorescence signal in detection of the cytokine TNF-alpha by a fluorescence sandwich immunoassay. PMID:19104594

  19. Deep optical access on multi-core and multi-mode fiber for integrated wireless applications

    NASA Astrophysics Data System (ADS)

    Llorente, Roberto; Morant, Maria; Beltrán, Marta; Macho, Andrés.

    2015-01-01

    Deep integrated optical access networks target to provide great capillarity and multiple ONTs for cost- and energy-efficient pervasive connectivity seamless supporting integrated wireless. Several key optical technologies are herein reported supporting integrated deep optical access: Bundled radio-over-fiber transmission is proposed and demonstrated for the provision of quintuple-play services achieving 125 km SSMF optical reach. Bend-insensitive fiber in-building distribution is also proposed and demonstrated supporting joint legacy coaxial transmission. Multimode POF is also proposed and demonstrated suitable for joint in-building distribution of MATV and SMATV broadcasting signals. Optical comb technology us is also demonstrated suitable for mm-wave radio generation of multiband OFDM wireless signals. Finally, multicore fiber transmission is also proposed and demonstrated suitable for the transmission of LTE and WIMAX in wireless fronthaul applications in a minimized inter-core crosstalk penalty configuration.

  20. Mode of action and application of Scorpion primers to mutation detection

    PubMed Central

    Thelwell, Nicola; Millington, Stephen; Solinas, Antonio; Booth, James; Brown, Tom

    2000-01-01

    Scorpion primers can be used to detect PCR products in homogeneous solution. Their structure promotes a unimolecular probing mechanism. We compare their performance with that of the same probe sequence forced to act in a bimolecular manner. The data suggest that Scorpions indeed probe by a unimolecular mechanism which is faster and more efficient than the bimolecular mechanism. This mechanism is not dependent on enzymatic cleavage of the probe. A direct comparison between Scorpions, TaqMan and Molecular Beacons on a Roche LightCycler indicates that Scorpions perform better, particularly under fast cycling conditions. Development of a cystic fibrosis mutation detection assay shows that Scorpion primers are selective enough to detect single base mutations and give good sensitivity in all cases. Simultaneous detection of both normal and mutant alleles in a single reaction is possible by combining two Scorpions in a multiplex reaction. Such favourable properties of Scorpion primers should make the technology ideal in numerous applications. PMID:11000267

  1. The Cyclic Antibacterial Peptide Enterocin AS-48: Isolation, Mode of Action, and Possible Food Applications

    PubMed Central

    Grande Burgos, María José; Pérez Pulido, Rubén; López Aguayo, María del Carmen; Gálvez, Antonio; Lucas, Rosario

    2014-01-01

    Enterocin AS-48 is a circular bacteriocin produced by Enterococcus. It contains a 70 amino acid-residue chain circularized by a head-to-tail peptide bond. The conformation of enterocin AS-48 is arranged into five alpha-helices with a compact globular structure. Enterocin AS-48 has a wide inhibitory spectrum on Gram-positive bacteria. Sensitivity of Gram-negative bacteria increases in combination with outer-membrane permeabilizing treatments. Eukaryotic cells are bacteriocin-resistant. This cationic peptide inserts into bacterial membranes and causes membrane permeabilization, leading ultimately to cell death. Microarray analysis revealed sets of up-regulated and down-regulated genes in Bacillus cereus cells treated with sublethal bacteriocin concentration. Enterocin AS-48 can be purified in two steps or prepared as lyophilized powder from cultures in whey-based substrates. The potential applications of enterocin AS-48 as a food biopreservative have been corroborated against foodborne pathogens and/or toxigenic bacteria (Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella enterica) and spoilage bacteria (Alicyclobacillus acidoterrestris, Bacillus spp., Paenibacillus spp., Geobacillus stearothermophilus, Brochothrix thermosphacta, Staphylococcus carnosus, Lactobacillus sakei and other spoilage lactic acid bacteria). The efficacy of enterocin AS-48 in food systems increases greatly in combination with chemical preservatives, essential oils, phenolic compounds, and physico-chemical treatments such as sublethal heat, high-intensity pulsed-electric fields or high hydrostatic pressure. PMID:25493478

  2. Explosive reconnection of the double tearing mode in relativistic plasmas with application to the Crab nebula

    NASA Astrophysics Data System (ADS)

    Pétri, J.; Takamoto, M.; Baty, H.; Zenitani, S.

    2015-01-01

    The Crab pulsar and its surrounding nebula is a well-known relic of a massive star that exploded in 1054 AD. The Crab nebula was generally believed to be a good standard candle in gamma rays. Recently, this view has been challenged by sudden increases in the gamma-ray flux in a narrow spectral band within a few hundred MeV. These flares are short but powerful; their duration is between a few hours and up to several days with a rising/falling time of a few hours/days. To date it is neither clear what mechanism powers these flares nor where exactly in the nebula they should be located. However, recent models seem to favor emission sites inside the nebula. In the present work, we study the magneto-hydrodynamic tearing instability occurring in a double current sheet configuration with application to the Crab flares. This is investigated by means of resistive relativistic magneto-hydrodynamic simulations. These put some constraints on the maximum Lorentz factor of the striped wind, Γ≲150 and on the localization of the emission region, r ≈ 50 rL where rL = c/Ω is the light-cylinder radius, c is the speed of light and Ω is the rotation speed of the pulsar. Sites close to but outside the light-cylinder are favored in our model.

  3. Interference of implanted cardiac pacemakers with TASER X26 dart mode application.

    PubMed

    Leitgeb, Norbert; Niedermayr, Florian; Neubauer, Robert

    2012-06-01

    The prevalence of pacemaker patients among the general population and of conducted energy devices for law enforcement and self-defence is increasing. Consequently, the question on whether cardiac pacemaker patients are at particular risk becomes increasingly important, in particular, as the widespread use of such devices is planned in Europe. The risk of pacemaker patients has been investigated by numerical simulation at detailed anatomical models of patients with cardiac pacemakers implanted in left pectoral, right pectoral, and abdominal positions, with the monopolar electrode placed at the ventricular apex. The induced cardiac pacemaker interference voltages have been assessed for distant application of TASER X26 devices with dart electrodes propelled towards a subject. It could be shown that interference voltages are highest in abdominal pacemaker implantation, while they are about 20% lower in left or right pectoral sites. They remain below the immunity threshold level as defined by safety standards of implanted cardiac pacemakers and of implanted cardioverter defibrillators to prevent persisting malfunction or damage. However, induced voltages are high enough to be sensed by the pacemaker and to capture pacemaker function in case of hits at thorax and abdomen, frontal as well as dorsal. PMID:22691428

  4. Prion Protein-Specific Antibodies-Development, Modes of Action and Therapeutics Application

    PubMed Central

    Rovis, Tihana Lenac; Legname, Giuseppe

    2014-01-01

    Prion diseases or Transmissible Spongiform Encephalopathies (TSEs) are lethal neurodegenerative disorders involving the misfolding of the host encoded cellular prion protein, PrPC. This physiological form of the protein is expressed throughout the body, and it reaches the highest levels in the central nervous system where the pathology occurs. The conversion into the pathogenic isoform denoted as prion or PrPSc is the key event in prion disorders. Prominent candidates for the treatment of prion diseases are antibodies and their derivatives. Anti-PrPC antibodies are able to clear PrPSc from cell culture of infected cells. Furthermore, application of anti-PrPC antibodies suppresses prion replication in experimental animal models. Major drawbacks of immunotherapy are immune tolerance, the risks of neurotoxic side effects, limited ability of compounds to cross the blood-brain barrier and their unfavorable pharmacokinetic. The focus of this review is to recapitulate the current understanding of the molecular mechanisms for antibody mediated anti-prion activity. Although relevant for designing immunotherapeutic tools, the characterization of key antibody parameters shaping the molecular mechanism of the PrPC to PrPSc conversion remains elusive. Moreover, this review illustrates the various attempts towards the development of anti-PrP antibody compounds and discusses therapeutic candidates that modulate PrP expression. PMID:25275428

  5. The Cyclic Antibacterial Peptide Enterocin AS-48: Isolation, Mode of Action, and Possible Food Applications.

    PubMed

    Grande Burgos, María José; Pulido, Rubén Pérez; Del Carmen López Aguayo, María; Gálvez, Antonio; Lucas, Rosario

    2014-01-01

    Enterocin AS-48 is a circular bacteriocin produced by Enterococcus. It contains a 70 amino acid-residue chain circularized by a head-to-tail peptide bond. The conformation of enterocin AS-48 is arranged into five alpha-helices with a compact globular structure. Enterocin AS-48 has a wide inhibitory spectrum on Gram-positive bacteria. Sensitivity of Gram-negative bacteria increases in combination with outer-membrane permeabilizing treatments. Eukaryotic cells are bacteriocin-resistant. This cationic peptide inserts into bacterial membranes and causes membrane permeabilization, leading ultimately to cell death. Microarray analysis revealed sets of up-regulated and down-regulated genes in Bacillus cereus cells treated with sublethal bacteriocin concentration. Enterocin AS-48 can be purified in two steps or prepared as lyophilized powder from cultures in whey-based substrates. The potential applications of enterocin AS-48 as a food biopreservative have been corroborated against foodborne pathogens and/or toxigenic bacteria (Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella enterica) and spoilage bacteria (Alicyclobacillus acidoterrestris, Bacillus spp., Paenibacillus spp., Geobacillus stearothermophilus, Brochothrix thermosphacta, Staphylococcus carnosus, Lactobacillus sakei and other spoilage lactic acid bacteria). The efficacy of enterocin AS-48 in food systems increases greatly in combination with chemical preservatives, essential oils, phenolic compounds, and physico-chemical treatments such as sublethal heat, high-intensity pulsed-electric fields or high hydrostatic pressure. PMID:25493478

  6. Interacting multiple zero mode formulation and its application to a system consisting of a dark soliton in a condensate

    NASA Astrophysics Data System (ADS)

    Takahashi, J.; Nakamura, Y.; Yamanaka, Y.

    2015-08-01

    To formulate the zero modes in a finite-size system with spontaneous breakdown of symmetries in quantum field theory is not trivial, for in the naive Bogoliubov theory, one encounters difficulties such as phase diffusion, the absence of a definite criterion for determining the ground state, and infrared divergences. An interacting zero mode formulation that has been proposed for systems with a single zero mode to avoid these difficulties is extended to general systems with multiple zero modes. It naturally and definitely gives the interactions among the quantized zero modes, the consequences of which can be observed experimentally. In this paper, as a typical example, we consider an atomic Bose-Einstein condensed system with a dark soliton that contains two zero modes corresponding to the spontaneous breakdown of the U(1) gauge and translational symmetries. Then we evaluate the standard deviations of the zero mode operators and see how the mutual interaction between the two zero modes affects them.

  7. Assessing the application and downstream effects of pulsed mode ultrasound as a pre-treatment for alum coagulation.

    PubMed

    Al-Juboori, Raed A; Aravinthan, Vasantha; Yusaf, Talal; Bowtell, Leslie

    2016-07-01

    The application of pulsed mode ultrasound (PMU) as a pre-treatment for alum coagulation was investigated at various alum dosages and pH levels. The effects of the treatments on turbidity and dissolved organic carbon (DOC) removal and residual Al were evaluated. Response surface methodology (RSM) was utilized to optimize the operating conditions of the applied treatments. The results showed that PMU pre-treatment increased turbidity and DOC removal percentages from maximum of 96.6% and 43% to 98.8% and 52%, respectively. It also helped decrease the minimum residual Al from 0.100 to 0.094 ppm. The multiple response optimization was carried out using the desirability function. A desirability value of >0.97 estimated respective turbidity removal, DOC removal and Al residual of 89.24%, 45.66% and ∼ 0.1 ppm for coagulation (control) and 90.61%, >55% and ∼ 0 for coagulation preceded by PMU. These figures were validated via confirmatory experiments. PMU pre-treatment increased total coliform removal from 80% to >98% and decreased trihalomethane formation potential (THMFP) from 250 to 200 ppb CH3Cl. Additionally, PMU application prior to coagulation improved the settleability of sludge due to the degassing effects. The results of this study confirms that PMU pre-treatment can significantly improve coagulation performance. PMID:26964919

  8. Advanced displays for the F/A-18E/F Hornet: application of AMLCD and touch sensing technology in an existing tactical fighter/attack crewstation

    NASA Astrophysics Data System (ADS)

    Hardy, Gregory J.; Wilkins, Donald F.; Wright, R. Nick

    1994-06-01

    This paper examines the role that advanced display technology has in the upgrade of the F/A- 18 Hornet to the E/F configuration. Application of Active-Matrix Liquid Crystal Display (AMLCD) technology improves display performance and reliability and enables increased display processing capability. The paper provides a system-level description of two of the new F/A-18E/F displays, the Multipurpose Color Display and the Touch-Sensitive Up-Front Control Display. A brief comparison of performance and capability to the CRT-based display technology that is being displaced is made in conjunction with a discussion of the key performance characteristics of the new display hardware and graphics generation circuitry. An overview of the challenges of incorporating AMLCD technology into an existing tactical fighter crewstation, including optical and thermal performance is provided, followed by a review of the testing that has been performed to validate AMLCD and Touch Sensing technology use in the F/A-18.

  9. The observation of super-long range surface plasmon polaritons modes and its application as sensory devices.

    PubMed

    Zhang, X-L; Song, J-F; Lo, G Q; Kwong, D-L

    2010-10-11

    In this communication, we will describe one unique phenomenon and the potential application of it. In this work, the dispersion relation of an air-silver-silicon-silver-fluid (air-Ag-Si-Ag-fluid) five-layer slab is analyzed theoretically, in which the super-long range surface plasmon polaritons (SPP) modes, whose energy penetrates deeply into the fluid, are found with their losses being extremely small and sensitive to the change of the fluid refractive index when operating near their interspace cut-off regions, where the dispersion curves are non-continuous. By applying this phenomenon in detecting the fluid refractive index change, a SPP sensor based on intensity measurement is proposed. It is a waveguide structure with an Ag-Si-Ag slab together with a flow cell filled with the detecting fluid. It is found that a large scale of linear detection (e.g., 0.08, for 1550 nm ~1.33 to 1.41) with high resolution (e.g., 7.9 × 10(-6) Refractive Index Units) can be achieved for a very short device, which is 200 μm. PMID:20941145

  10. Application of Benchmark Examples to Assess the Single and Mixed-Mode Static Delamination Propagation Capabilities in ANSYS

    NASA Technical Reports Server (NTRS)

    Krueger, Ronald

    2012-01-01

    The application of benchmark examples for the assessment of quasi-static delamination propagation capabilities is demonstrated for ANSYS. The examples are independent of the analysis software used and allow the assessment of the automated delamination propagation in commercial finite element codes based on the virtual crack closure technique (VCCT). The examples selected are based on two-dimensional finite element models of Double Cantilever Beam (DCB), End-Notched Flexure (ENF), Mixed-Mode Bending (MMB) and Single Leg Bending (SLB) specimens. First, the quasi-static benchmark examples were recreated for each specimen using the current implementation of VCCT in ANSYS . Second, the delamination was allowed to propagate under quasi-static loading from its initial location using the automated procedure implemented in the finite element software. Third, the load-displacement relationship from a propagation analysis and the benchmark results were compared, and good agreement could be achieved by selecting the appropriate input parameters. The benchmarking procedure proved valuable by highlighting the issues associated with choosing the input parameters of the particular implementation. Overall the results are encouraging, but further assessment for three-dimensional solid models is required.

  11. Dynamical instabilities and quasi-normal modes, a spectral analysis with applications to black-hole physics

    NASA Astrophysics Data System (ADS)

    Coutant, Antonin; Michel, Florent; Parentani, Renaud

    2016-06-01

    Black hole dynamical instabilities have been mostly studied in specific models. We here study the general properties of the complex-frequency modes responsible for such instabilities, guided by the example of a charged scalar field in an electrostatic potential. We show that these modes are square integrable, have a vanishing conserved norm, and appear in mode doublets or quartets. We also study how they appear in the spectrum and how their complex frequencies subsequently evolve when varying some external parameter. When working on an infinite domain, they appear from the reservoir of quasi-normal modes obeying outgoing boundary conditions. This is illustrated by generalizing, in a non-positive definite Krein space, a solvable model (Friedrichs model) which originally describes the appearance of a resonance when coupling an isolated system to a mode continuum. In a finite spatial domain instead, they arise from the fusion of two real frequency modes with opposite norms, through a process that closely resembles avoided crossing.

  12. Gas laser mode-locking using an external acoustooptic modulator with a potential application to passive ring gyroscopes

    SciTech Connect

    Dunn, R.W.; Hendow, S.T.; Small, J.G.; Stijns, E.

    1982-11-15

    In this Letter, we show that the fundamental pulsation frequency of the mode-locked laser can be multiplied by an integer number by simply changing the length of a secondary cavity formed by the AOM and an external mirror. Furthermore, we show that a mode-locked laser may be used to enhance the SNR in passive ring gyroscopes by matching multiple modes of the laser to those of the passive cavity.

  13. Verification and application of the extended spectral deconvolution algorithm (SDA+) methodology to estimate aerosol fine and coarse mode extinction coefficients in the marine boundary layer

    NASA Astrophysics Data System (ADS)

    Kaku, K. C.; Reid, J. S.; O'Neill, N. T.; Quinn, P. K.; Coffman, D. J.; Eck, T. F.

    2014-10-01

    The spectral deconvolution algorithm (SDA) and SDA+ (extended SDA) methodologies can be employed to separate the fine and coarse mode extinction coefficients from measured total aerosol extinction coefficients, but their common use is currently limited to AERONET (AErosol RObotic NETwork) aerosol optical depth (AOD). Here we provide the verification of the SDA+ methodology on a non-AERONET aerosol product, by applying it to fine and coarse mode nephelometer and particle soot absorption photometer (PSAP) data sets collected in the marine boundary layer. Using data sets collected on research vessels by NOAA-PMEL(National Oceanic and Atmospheric Administration - Pacific Marine Environmental Laboratory), we demonstrate that with accurate input, SDA+ is able to predict the fine and coarse mode scattering and extinction coefficient partition in global data sets representing a range of aerosol regimes. However, in low-extinction regimes commonly found in the clean marine boundary layer, SDA+ output accuracy is sensitive to instrumental calibration errors. This work was extended to the calculation of coarse and fine mode scattering coefficients with similar success. This effort not only verifies the application of the SDA+ method to in situ data, but by inference verifies the method as a whole for a host of applications, including AERONET. Study results open the door to much more extensive use of nephelometers and PSAPs, with the ability to calculate fine and coarse mode scattering and extinction coefficients in field campaigns that do not have the resources to explicitly measure these values.

  14. The Coupled Spectral Element/Normal Mode Method: Application to the Testing of Several Approximations Based on Normal Mode Theory for the Computation of Seismograms in a Realistic 3D Earth.

    NASA Astrophysics Data System (ADS)

    Capdeville, Y.; Gung, Y.; Romanowicz, B.

    2002-12-01

    The spectral element method (SEM) has recently been adapted successfully for global spherical earth wave propagation applications. Its advantage is that it provides a way to compute exact seismograms in a 3D earth, without restrictions on the size or wavelength of lateral heterogeneity at any depth, and can handle diffraction and other interactions with major structural boundaries. Its disadvantage is that it is computationally heavy. In order to partly address this drawback, a coupled SEM/normal mode method was developed (Capdeville et al., 2000). This enables us to more efficiently compute bodywave seismograms to realistically short periods (10s or less). In particular, the coupled SEM/normal mode method is a powerful tool to test the validity of some analytical approximations that are currently used in global waveform tomography, and that are considerably faster computationally. Here, we focus on several approximations based on normal mode perturbation theory: the classical "path-average approximation" (PAVA) introduced by Woodhouse and Dziewonski (1984) and well suited for fundamental mode surface waves (1D sensitivity kernels); the non-linear asymptotic coupling theory (NACT), which introduces coupling between mode branches and 2D kernels in the vertical plane containing the source and the receiver (Li and Tanimoto, 1993; Li and Romanowicz, 1995); an extension of NACT which includes out of plane focusing terms computed asymptotically (e.g. Romanowicz, 1987) and introduces 3D kernels; we also consider first order perturbation theory without asymptotic approximations, such as developed for example by Dahlen et al. (2000). We present the results of comparisons of realistic seismograms for different models of heterogeneity, varying the strength and sharpness of the heterogeneity and its location in depth in the mantle. We discuss the consequences of different levels of approximations on our ability to resolve 3D heterogeneity in the earth's mantle.

  15. Effect of the regional variability of dentinal substrate and modes of application of adhesive systems on the mechanical properties of the adhesive layer

    PubMed Central

    Pupo, Yasmine Mendes; Michél, Milton Domingos; Gomes, Osnara Maria Mongruel; Lepienski, Carlos Maurício; Gomes, João Carlos

    2012-01-01

    Aim: This study assessed the effect of the dentin depth and the application mode on the hardness and elastic modulus of the adhesive layer. Materials and Methods: Occlusal surfaces of 48 caries-free human third molars were removed, at two levels: Superficial and deep dentin. For each type of surface, the test specimens were randomly divided into groups which underwent the application: A conventional two-step adhesive system (Adper™ Single Bond [SB]) and self-etch adhesives system (Adper™ SE Plus [SE] and AdheSE® [AD]). The adhesives applied were active or passive. Composite build-ups were constructed incrementally. The teeth were sectioned, embedded, and polished. The nanoindentation test was performed in the adhesive layer. The results were analyzed by ANOVA and Tukey tests. Results: In the adhesive layer, the higher hardness (0.307 ± 0.006 GPa) and elastic modulus (4.796 ± 0.165 GPa) of SE were obtained in superficial dentin in passive application. The elastic modulus of SE (4.115 ± 0.098 GPa) was lowest in active application in superficial dentin. The active application significantly increased the hardness of the SB in the deep dentin (0.011 ± 0.314 GPa) compared the superficial dentin (0.280 ± 0.010 GPa). For the AD, only the mode of application was statistically significant (P=0.0041) for the hardness, active application (0.289 ± 0.015 GPa) being higher than passive application (0.261 ± 0.013 GPa) (P=0.0042) in deep dentin. Conclusion: The experimental results reveal that the mechanical properties were influenced for the application mode of adhesive systems and dentin depth. PMID:22557810

  16. Exploring Existence Value

    NASA Astrophysics Data System (ADS)

    Madariaga, Bruce; McConnell, Kenneth E.

    1987-05-01

    The notion that individuals value the preservation of water resources independent of their own use of these resources is discussed. Issues in defining this value, termed "existence value," are explored. Economic models are employed to assess the role of existence value in benefit-cost analysis. The motives underlying existence value are shown to matter to contingent valuation measurement of existence benefits. A stylized contingent valuation experiment is used to study nonusers' attitudes regarding projects to improve water quality in the Chesapeake Bay. Survey results indicate that altruism is one of the motives underlying existence value and that goods other than environmental and natural resources may provide existence benefits.

  17. An enhanced Fourier law derivable from the Boltzmann transport equation and a sample application in determining the mean-free path of nondiffusive phonon modes

    NASA Astrophysics Data System (ADS)

    Ramu, Ashok T.; Ma, Yanbao

    2014-09-01

    An enhanced Fourier law that we term the unified nondiffusive-diffusive (UND) phonon transport model is proposed in order to account for the effect of low-frequency phonon modes of long mean-free path that propagate concomitantly to the dominant high-frequency modes. The theory is based on spherical harmonic expansions of the phonon distribution functions, wherein the high-frequency mode distribution function is truncated at the first order in the expansion, while the low-frequency mode distribution function, which is farther out of thermal equilibrium, is truncated at the second order. As an illustrative application, the predictions of the proposed model are compared with data from a recent experiment that utilized the transient gratings method to investigate the deviation of thermal transport in a silicon membrane from the predictions of the Fourier law. The good fit of the experimental effective thermal conductivity (ETC) with the analytical solution derived in this work yields quantitative information about the mean-free path of the dominant low-frequency heat-transfer mode in silicon.

  18. Application of filter method for detection of secondary electron emission in the auto-oscillating mode of beam plasma discharge

    NASA Astrophysics Data System (ADS)

    Balovnev, A. V.; Vizgalov, I. V.; Salahutdinov, G. H.

    2016-01-01

    In this paper we studied the non-self mode of the auto-oscillation secondary- emission discharge (ASED) in a longitudinal magnetic field with autonomous electron gun to ignite the primary beam-plasma discharge (PPD).

  19. A wearable ECG-HR detector and its application to automatic assist-mode selection of an electrically assisted bicycle.

    PubMed

    Ueno, Akinori; Miyashita, Osamu; Yoshida, Toshiya; Yamamoto, Junichi; Lataire, Philippe

    2011-01-01

    Recently, an electrically assisted bicycle has been widely used in daily life and becomes very popular. The user selects the stepwise assist-mode to determine the assistive torque for pleasurable running. From the viewpoint of improvement of health by exercise, the electrically assisted bicycle can be an exercise machine like a treadmill. The heart rate (HR) is regarded as an indication of exercise load. This paper presents an automatic assist-mode selection system based on the HR of the bicycle user. The HR is obtained from the R-waves measured by the proposed wearable electrocardiograph on the user. The mode-selection system is simply implemented by a personal computer, USB-connected interface, and some electronic switching circuits. The running experiments confirm that the proposed assist-mode selection method has practicability. PMID:22255925

  20. Decomposition of the complex system into nonlinear spatio-temporal modes: algorithm and application to climate data mining

    NASA Astrophysics Data System (ADS)

    Feigin, Alexander; Gavrilov, Andrey; Loskutov, Evgeny; Mukhin, Dmitry

    2015-04-01

    Proper decomposition of the complex system into well separated "modes" is a way to reveal and understand the mechanisms governing the system behaviour as well as discover essential feedbacks and nonlinearities. The decomposition is also natural procedure that provides to construct adequate and concurrently simplest models of both corresponding sub-systems, and of the system in whole. In recent works two new methods of decomposition of the Earth's climate system into well separated modes were discussed. The first method [1-3] is based on the MSSA (Multichannel Singular Spectral Analysis) [4] for linear expanding vector (space-distributed) time series and makes allowance delayed correlations of the processes recorded in spatially separated points. The second one [5-7] allows to construct nonlinear dynamic modes, but neglects delay of correlations. It was demonstrated [1-3] that first method provides effective separation of different time scales, but prevent from correct reduction of data dimension: slope of variance spectrum of spatio-temporal empirical orthogonal functions that are "structural material" for linear spatio-temporal modes, is too flat. The second method overcomes this problem: variance spectrum of nonlinear modes falls essentially sharply [5-7]. However neglecting time-lag correlations brings error of mode selection that is uncontrolled and increases with growth of mode time scale. In the report we combine these two methods in such a way that the developed algorithm allows constructing nonlinear spatio-temporal modes. The algorithm is applied for decomposition of (i) multi hundreds years globally distributed data generated by the INM RAS Coupled Climate Model [8], and (ii) 156 years time series of SST anomalies distributed over the globe [9]. We compare efficiency of different methods of decomposition and discuss the abilities of nonlinear spatio-temporal modes for construction of adequate and concurrently simplest ("optimal") models of climate systems

  1. Systems Biology & Mode of Action Based Risk Assessment

    EPA Science Inventory

    The application of systems biology for risk assessment of environmental chemicals is a national extension of its use in pharmaceutical research. The basis for this is the concept of a key event network that builds on existing mode of action frameworks for risk assessment. The a...

  2. Application of strongly overcoupled resonant modes of long-period fiber gratings to measure the adulteration of olive oil.

    PubMed

    Biswas, Palas; Basumallick, Nandini; Dasgupta, Kamal; Ghosh, Ajay; Bandyopadhyay, Somnath

    2016-07-01

    We have shown that strongly overcoupled resonant modes of long-period fiber gratings (LPFGs) can be used to assess the adulteration of olive oil. In this background, we investigate the response characteristics of strongly overcoupled resonant modes of different orders to a surrounding medium, the refractive index (RI) of which is greater than that of the fiber cladding, and in the range where a precise refractive index measurement is immensely useful for inspecting the quality of olive oils and other edible oils. A theoretical simulation that would help in designing a sensor with suitable sensitivity and range of measurement has been presented in detail and also validated with experimental results. It was interesting to observe that in a high RI surrounding, a lower order overcoupled resonant mode is much more sensitive as compared to a higher-order one having a similar coupling coefficient. A quantitative analysis demonstrates that for a particular LPFG, the sensitivity of a strongly overcoupled LP06 mode was found to be ∼2000  dB/RIU, while that of the LP07 mode having similar coupling strength was ∼550  dB/RIU in the surrounding refractive index range from 1.458 to 1.520. The results have been validated experimentally. PMID:27409199

  3. Experimental entanglement of 60 modes of the quantum optical frequency comb and application to generating hypercubic-lattice cluster states

    NASA Astrophysics Data System (ADS)

    Pfister, Olivier; Chen, Moran; Wang, Pei; Fan, Wenjiang; Menicucci, Nicolas

    2014-05-01

    In the race to build a practical quantum computer in the laboratory, the ability to create very large quantum registers and entangle them is paramount, along with the ability to address the issue of decoherence. With particular regard to scalability, the field-based, continuous-variable (CV) flavor of quantum optics offers notable promise, in particular by enabling ``top down,'' rather than ``bottom up,'' entangling approaches of quantum field modes. It is also important to note the relevance of continuous variables to universal quantum computing, with the recent discovery of a fault tolerance threshold for quantum computing with CV cluster states and nonGaussian error correction. In 2011, some of us generated simultaneously 15 independent 4-mode cluster states over 60 modes of the quantum optical frequency comb (QOFC) of a single optical parametric oscillator (OPO). In this work, we used a single OPO to generate a 60-mode dual-rail cluster state, which is the largest entangled system to date whose subsystems are all simultaneously available. Using the exact same setup, we also generated two copies of a 30-mode dual-rail cluster state. We will then present a new proposal to ``weave'' such massively scalable continuous-variable cluster states into hypercubic-lattice quantum graphs Work supported by NSF grants PHY-0855632 and PHY-1206029.

  4. Photon Temporal Modes: A Complete Framework for Quantum Information Science

    NASA Astrophysics Data System (ADS)

    Brecht, B.; Reddy, Dileep V.; Silberhorn, C.; Raymer, M. G.

    2015-10-01

    Field-orthogonal temporal modes of photonic quantum states provide a new framework for quantum information science (QIS). They intrinsically span a high-dimensional Hilbert space and lend themselves to integration into existing single-mode fiber communication networks. We show that the three main requirements to construct a valid framework for QIS—the controlled generation of resource states, the targeted and highly efficient manipulation of temporal modes, and their efficient detection—can be fulfilled with current technology. We suggest implementations of diverse QIS applications based on this complete set of building blocks.

  5. Development of fracture facets from a crack loaded in mode I+III: Solution and application of a model 2D problem

    NASA Astrophysics Data System (ADS)

    Leblond, Jean-Baptiste; Frelat, Joël

    2014-03-01

    It is experimentally well-known that a crack loaded in mode I+III propagates through formation of discrete fracture facets inclined at a certain tilt angle on the original crack plane, depending on the ratio of the mode III to mode I initial stress intensity factors. Pollard et al. (1982) have proposed to calculate this angle by considering the tractions on all possible future infinitesimal facets and assuming shear tractions to be zero on that which will actually develop. In this paper we consider the opposite case of well-developed facets; the stress field near the lateral fronts of such facets becomes independent of the initial crack and essentially 2D in a plane perpendicular to the main direction of crack propagation. To determine this stress field, we solve the model 2D problem of an infinite plate containing an infinite periodic array of cracks inclined at some angle on a straight line, and loaded through uniform stresses at infinity. This is done first analytically, for small values of this angle, by combining Muskhelishvili's (1953) formalism and a first-order perturbation procedure. The formulae found for the 2D stress intensity factors are then extended in an approximate way to larger angles by using another reference solution, and finally assessed through comparison with some finite element results. To finally illustrate the possible future application of these formulae to the prediction of the stationary tilt angle, we introduce the tentative assumption that the 2D mode II stress intensity factor is zero on the lateral fronts of the facets. An approximate formula providing the tilt angle as a function of the ratio of the mode III to mode I stress intensity factors of the initial crack is deduced from there. This formula, which slightly depends on the type of loading imposed, predicts somewhat smaller angles than that of Pollard et al. (1982).

  6. Modeling of Beams’ Multiple-Contact Mode with an Application in the Design of a High-g Threshold Microaccelerometer

    PubMed Central

    Li, Kai; Chen, Wenyuan; Zhang, Weiping

    2011-01-01

    Beam’s multiple-contact mode, characterized by multiple and discrete contact regions, non-uniform stoppers’ heights, irregular contact sequence, seesaw-like effect, indirect interaction between different stoppers, and complex coupling relationship between loads and deformation is studied. A novel analysis method and a novel high speed calculation model are developed for multiple-contact mode under mechanical load and electrostatic load, without limitations on stopper height and distribution, providing the beam has stepped or curved shape. Accurate values of deflection, contact load, contact region and so on are obtained directly, with a subsequent validation by CoventorWare. A new concept design of high-g threshold microaccelerometer based on multiple-contact mode is presented, featuring multiple acceleration thresholds of one sensitive component and consequently small sensor size. PMID:22163897

  7. A regularized relaxed ordered subset list-mode reconstruction algorithm and its preliminary application to undersampling PET imaging

    NASA Astrophysics Data System (ADS)

    Cao, Xiaoqing; Xie, Qingguo; Xiao, Peng

    2015-01-01

    List mode format is commonly used in modern positron emission tomography (PET) for image reconstruction due to certain special advantages. In this work, we proposed a list mode based regularized relaxed ordered subset (LMROS) algorithm for static PET imaging. LMROS is able to work with regularization terms which can be formulated as twice differentiable convex functions. Such a versatility would make LMROS a convenient and general framework for fulfilling different regularized list mode reconstruction methods. LMROS was applied to two simulated undersampling PET imaging scenarios to verify its effectiveness. Convex quadratic function, total variation constraint, non-local means and dictionary learning based regularization methods were successfully realized for different cases. The results showed that the LMROS algorithm was effective and some regularization methods greatly reduced the distortions and artifacts caused by undersampling.

  8. Regularization of singular eigenfunctions of an operator with continuous spectra: With applications for ballooning modes in toroidally rotating tokamaks

    NASA Astrophysics Data System (ADS)

    Furukawa, M.; Yoshida, Z.; Tokuda, S.

    2005-07-01

    Eigenfunction expansions of fields encounter practical difficulty when the generating operator has continuous spectra (as is common in magnetohydrodynamics theories). An appropriate "weight function" may remove the singularity of the eigenfunctions belonging to the continuous spectrum and the complete set of regularized (square-integrable) eigenfunctions can be obtained. As an example, this method has been applied for ballooning modes in toroidally rotating tokamaks. While the weight function truncates the long-term behavior of modes, the regularized eigenfunctions can describe transient behavior within a finite time.

  9. Highly angular dependent high-contrast grating mirror and its application for transverse-mode control of VCSELs

    NASA Astrophysics Data System (ADS)

    Inoue, Shunya; Kashino, Junichi; Matsutani, Akihiro; Ohtsuki, Hideo; Miyashita, Takahiro; Koyama, Fumio

    2014-09-01

    We report on the design and fabrication of a highly angular dependent high contrast grating (HCG) mirror. The modeling and experiment on amorphous-Si/SiO2 HCG clearly show the large angular dependence of reflectivity, which enables single transverse-mode operations of large-area VCSELs. We fabricate 980 nm VCSELs with the angular dependent HCG functioning as a spatial frequency filter. We obtained the single transverse mode operation of the fabricated device in contrast to conventional VCSELs with semiconductor multilayer mirrors.

  10. Performance evaluation of a prototype multi-bounce time-of-flight mass spectrometer in linear mode and applications in space science

    NASA Astrophysics Data System (ADS)

    Hässig, M.; Libardoni, M.; Mandt, K.; Miller, G.; Blase, R.

    2015-11-01

    Mass spectrometry is a powerful tool to measure the composition of volatile and semi volatile gases. The necessity to accurately identify and quantify unknown species lead to the requirements of a mass spectrometer as the detector of choice in most separation science and direct sample analysis situations. Advantages of time-of-flight mass spectrometry (TOFMS) are the high mass resolution, high mass range, and the measurement of the entire mass range in each extraction. The multi-bounce time-of-flight mass spectrometer (MBTOF) described in this work, takes advantage of a small footprint without sacrificing mass resolution. To achieve this, the MBTOF prototype uses a linear flight path with dual lens stacks. Ions are bounced in between the mirrors for a specified duration whereby increasing their flight time and resolution. The number of bounces can tune the resolution of the instrument. To show the minimum capabilities of the instrument and further applications of it, MBTOF was operated in linear mode. The instrument is designed for a multibounce passage of the ion optics and the focal point of the ion optics is optimized for this application, therefore the resolution in linear mode is limited. However, even in linear mode of operation, the mass resolution meets or exceeds that of a quadrupole mass spectrometer with limited power supplies required for operations. The measurements presented here are based on lab measurements of the early lab prototype MBTOF operated in a linear flight mode with low ion source extraction fields. A detailed evaluation including filament characterization, dynamic range and resolution are investigated. Further discussion involving applications on planetary missions for rocket science, coupling of MBTOF with laser thermal desorption or gas chromatography for potential organic determination in deep space are included.

  11. 46 CFR 188.05-3 - New vessels and existing vessels for the purpose of application of regulations in this subchapter.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... valid certificate of inspection as an oceanographic research vessel on March 1, 1968. (c) Other vessels... HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS GENERAL PROVISIONS Application § 188.05-3 New..., initially inspected and certificated as an oceanographic research vessel on or after March 1, 1968,...

  12. 46 CFR 188.05-3 - New vessels and existing vessels for the purpose of application of regulations in this subchapter.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... valid certificate of inspection as an oceanographic research vessel on March 1, 1968. (c) Other vessels... HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS GENERAL PROVISIONS Application § 188.05-3 New..., initially inspected and certificated as an oceanographic research vessel on or after March 1, 1968,...

  13. Evaluation and application of a mixed-mode chromatographic stationary phase in two-dimensional liquid chromatography for the separation of traditional Chinese medicine.

    PubMed

    Wei, Zhishen; Fu, Qing; Cai, Jianfeng; Huan, Liyun; Zhao, Jianchao; Shi, Hui; Jin, Yu; Liang, Xinmiao

    2016-06-01

    In this study, two mixed-mode chromatography stationary phases (C8SAX and C8SCX) were evaluated and used to establish a two-dimensional liquid chromatography system for the separation of traditional Chinese medicine. The chromatographic properties of the mixed-mode columns were systematically evaluated by comparing with other three columns of C8, strong anion exchanger, and strong cation exchanger. The result showed that C8SAX and C8SCX had a mixed-mode retention mechanism including electrostatic interaction and hydrophobic interaction. Especially, they were suitable for separating acidic and/or basic compounds and their separation selectivities could be easily adjusted by changing pH value. Then, several off-line 2D-LC systems based on the C8SAX in the first dimension and C8SAX, C8SCX, or C8 columns in the second dimension were developed to analyze a traditional Chinese medicine-Uncaria rhynchophylla. The two-dimensional liquid chromatography system of C8SAX (pH 3.0) × C8SAX (pH 6.0) exhibited the most effective peak distribution. Finally, fractions of U. rhynchophylla prepared from the first dimension were successfully separated on the C8SAX column with a gradient pH. Thus, the mixed-mode stationary phase could provide a platform to separate the traditional Chinese medicine in practical applications. PMID:27159545

  14. Methods of component mode synthesis

    NASA Technical Reports Server (NTRS)

    Craig, R. R., Jr.

    1977-01-01

    A generalized substructure coupling, or component mode synthesis, procedure is described. Specific methods, applications, and such special topics as damping and experimental verification are surveyed.

  15. Single mode 1.3 μm InGaAs VCSELs for access network applications

    NASA Astrophysics Data System (ADS)

    Westbergh, Petter; Söderberg, Emma; Gustavsson, Johan S.; Modh, Peter; Larsson, Anders; Zhang, Zhenzhong; Berggren, Jesper; Hammar, Mattias

    2008-04-01

    GaAs-based VCSELs emitting near 1.3 μm are realized using highly strained InGaAs quantum wells and a large detuning of the cavity resonance with respect to the gain peak. The VCSELs have an oxide aperture for current and optical confinement and an inverted surface relief for suppression of higher-order transverse modes. The inverted surface relief structure also has the advantage of suppressing oxide modes that otherwise appear in VCSELs with a large detuning between the cavity resonance and the gain peak. Under large signal, digital modulation, clear and open eyes and error free transmission over 9 km of single mode fiber have been demonstrated at the OC-48 and 10 GbE bit rates up to 85°C. Here we review these results and present results from a complementary study of the RF modulation characteristics, including second order harmonic and third order intermodulation distortion, relative intensity noise (RIN), and spurious free dynamic range (SFDR). RIN levels comparable to those of single mode VCSELs emitting at 850 nm are demonstrated, with values from -140 to -150 dB/Hz. SFDR values of 100 and 95 dB•Hz 2/3 were obtained at 2 and 5 GHz, respectively, which is in the range of those required in radio-over-fiber systems.

  16. Communication Modes Used with Hearing-Impaired Students: Investigations and Applications to a School/Home Program.

    ERIC Educational Resources Information Center

    Van Metre, Patricia D.; Maxwell, Madeline M.

    1981-01-01

    The use to and by 40 hearing impaired students (3 to 18 years old) of speech, signs, fingerspelling, writing, gestures, American Sign Language, and pictures was investigated. Findings of a nationwide study were combined with local data to make recommendations for a program concentrating on modes, usage, flexibility, and cognitive/linguistic…

  17. Saturable absorbers incorporating carbon nanotubes directly synthesized onto substrates and fibers and their application to mode-locked fiber lasers

    NASA Astrophysics Data System (ADS)

    Yamashita, S.; Inoue, Y.; Maruyama, S.; Murakami, Y.; Yaguchi, H.; Jablonski, M.; Set, S. Y.

    2004-07-01

    We present novel carbon-nanotube-based saturable absorbers. Using the low-temperature alcohol catalytic chemical-vapor deposition method, high-quality single-walled carbon nanotubes (SWNTs) were directly synthesized on quartz substrates and fiber ends. We successfully applied the SWNTs to mode lock a fiber laser producing subpicosecond pulses at a 50-MHz repetition rate.

  18. Mode width fitting with a simple Bayesian approach. Application to CoRoT targets HD 181420 and HD 49933

    NASA Astrophysics Data System (ADS)

    Gaulme, P.; Appourchaux, T.; Boumier, P.

    2009-10-01

    Aims: We investigate the asteroseismology of two solar-like targets as observed with the CoRoT satellite, with particular attention paid to the mode fitting. HD 181420 and HD 49933 are typical CoRoT solar-like targets (156 and 60-day runs). The low signal-to-noise ratio (SNR) of about 3{-}10 prevents us from unambiguously identifying the individual oscillation modes. In particular, convergence problems appear at the edges of the oscillation spectrum. Methods: We apply a Bayesian approach to the analysis of these data. We compare the global fitting of the power spectra obtained by the classical maximum likelihood (MLE) and the maximum a posteriori (MAP) estimators. Results: We examine the impact of the choice of the priors upon the fitted parameters. We also propose to reduce the number of free parameters in the fitting, by replacing the individual estimate of mode height associated with each overtone by a continuous function of frequency (Gaussian profile). Conclusions: The MAP appears as a powerful tool to constrain the global fits, but it must be used carefully and only with reliable priors. The mode width of the stars increases with the frequency over all the oscillation spectrum. The CoRoT space mission, launched on 2006 December 27, was developed and is operated by the CNES, with participation of the Science Programs of ESA, ESA's RSSD, Austria, Belgium, Brazil, Germany and Spain.

  19. Experiences in the Application of Project-Based Learning in a Switching-Mode Power Supplies Course

    ERIC Educational Resources Information Center

    Lamar, D. G.; Miaja, P. F.; Arias, M.; Rodriguez, A.; Rodriguez, M.; Vazquez, A.; Hernando, M. M.; Sebastian, J.

    2012-01-01

    This paper presents the introduction of problem-based learning (PBL) in a power electronics course at the University of Oviedo, Gijon, Spain, by means of two practical projects: the design and construction of a switching-mode power supply (SMPS) prototype and the static study of a dc-dc converter topology. The goal of this innovation was for…

  20. Theory of coupled whistler-electron temperature gradient mode in high beta plasma: Application to linear plasma device

    SciTech Connect

    Singh, S. K.; Awasthi, L. M.; Singh, R.; Kaw, P. K.; Jha, R.; Mattoo, S. K.

    2011-10-15

    This paper presents a theory of coupled whistler (W) and electron temperature gradient (ETG) mode using two-fluid model in high beta plasma. Non-adiabatic ion response, parallel magnetic field perturbation ({delta}B{sub z}), perpendicular magnetic flutter ({delta}B{sub perpendicular}), and electron collisions are included in the treatment of theory. A linear dispersion relation for whistler-electron temperature gradient (W-ETG) mode is derived. The numerical results obtained from this relation are compared with the experimental results observed in large volume plasma device (LVPD) [Awasthi et al., Phys. Plasma 17, 42109 (2010)]. The theory predicts that the instability grows only where the temperature gradient is finite and the density gradient flat. For the parameters of the experiment, theoretically estimated frequency and wave number of W-ETG mode match with the values corresponding to the peak in the power spectrum observed in LVPD. By using simple mixing length argument, estimated level of fluctuations of W-ETG mode is in the range of fluctuation level observed in LVPD.

  1. Development and Application of Benchmark Examples for Mixed-Mode I/II Quasi-Static Delamination Propagation Predictions

    NASA Technical Reports Server (NTRS)

    Krueger, Ronald

    2012-01-01

    The development of benchmark examples for quasi-static delamination propagation prediction is presented and demonstrated for a commercial code. The examples are based on finite element models of the Mixed-Mode Bending (MMB) specimen. The examples are independent of the analysis software used and allow the assessment of the automated delamination propagation prediction capability in commercial finite element codes based on the virtual crack closure technique (VCCT). First, quasi-static benchmark examples were created for the specimen. Second, starting from an initially straight front, the delamination was allowed to propagate under quasi-static loading. Third, the load-displacement relationship from a propagation analysis and the benchmark results were compared, and good agreement could be achieved by selecting the appropriate input parameters. Good agreement between the results obtained from the automated propagation analysis and the benchmark results could be achieved by selecting input parameters that had previously been determined during analyses of mode I Double Cantilever Beam and mode II End Notched Flexure specimens. The benchmarking procedure proved valuable by highlighting the issues associated with choosing the input parameters of the particular implementation. Overall the results are encouraging, but further assessment for mixed-mode delamination fatigue onset and growth is required.

  2. Effect of the existing form of Cu element on the mechanical properties, bio-corrosion and antibacterial properties of Ti-Cu alloys for biomedical application.

    PubMed

    Zhang, Erlin; Wang, Xiaoyan; Chen, Mian; Hou, Bing

    2016-12-01

    Ti-Cu alloys have exhibited strong antibacterial ability, but Ti-Cu alloys prepared by different processes showed different antibacterial ability. In order to reveal the controlling mechanism, Ti-Cu alloys with different existing forms of Cu element were prepared in this paper. The effects of the Cu existing form on the microstructure, mechanical, corrosion and antibacterial properties of Ti-Cu alloys have been systematically investigated. Results have shown that the as-cast Ti-Cu alloys showed a higher hardness and mechanical strength as well as a higher antibacterial rate (51-64%) but a relatively lower corrosion resistance than pure titanium. Treatment at 900°C/2h (T4) significantly increased the hardness and the strength, improved the corrosion resistance but had little effect on the antibacterial property. Treatment at 900°C/2h+400°C/12h (T6) increased further the hardness and the mechanical strength, improved the corrosion resistance and but also enhanced the antibacterial rate (>90%) significantly. It was demonstrated that the Cu element in solid solution state showed high strengthening ability but low antibacterial property while Cu element in Ti2Cu phase exhibited strong strengthening ability and strong antibacterial property. Ti2Cu phase played a key role in the antibacterial mechanism. The antibacterial ability of Ti-Cu alloy was strongly proportional to the Cu content and the surface area of Ti2Cu phase. High Cu content and fine Ti2Cu phase would contribute to a high strength and a strong antibacterial ability. PMID:27612819

  3. Cogeneration for existing alfalfa processing

    SciTech Connect

    Not Available

    1984-01-01

    This study is designed to look at the application of gas-turbine generator cogeneration to a typical Nebraska alfalfa processing mill. The practicality is examined of installing a combustion turbine generator at a plant site and modifying existing facilities for generating electricity, utilizing the electricity generated, selling excess electricity to the power company and incorporating the turbine exhaust flow as a drying medium for the alfalfa. The results of this study are not conclusive but the findings are summarized.

  4. Risk assessment of component failure modes and human errors using a new FMECA approach: application in the safety analysis of HDR brachytherapy.

    PubMed

    Giardina, M; Castiglia, F; Tomarchio, E

    2014-12-01

    Failure mode, effects and criticality analysis (FMECA) is a safety technique extensively used in many different industrial fields to identify and prevent potential failures. In the application of traditional FMECA, the risk priority number (RPN) is determined to rank the failure modes; however, the method has been criticised for having several weaknesses. Moreover, it is unable to adequately deal with human errors or negligence. In this paper, a new versatile fuzzy rule-based assessment model is proposed to evaluate the RPN index to rank both component failure and human error. The proposed methodology is applied to potential radiological over-exposure of patients during high-dose-rate brachytherapy treatments. The critical analysis of the results can provide recommendations and suggestions regarding safety provisions for the equipment and procedures required to reduce the occurrence of accidental events. PMID:25379678

  5. Application of Failure Mode and Effect Analysis (FMEA), cause and effect analysis, and Pareto diagram in conjunction with HACCP to a corn curl manufacturing plant.

    PubMed

    Varzakas, Theodoros H; Arvanitoyannis, Ioannis S

    2007-01-01

    The Failure Mode and Effect Analysis (FMEA) model has been applied for the risk assessment of corn curl manufacturing. A tentative approach of FMEA application to the snacks industry was attempted in an effort to exclude the presence of GMOs in the final product. This is of crucial importance both from the ethics and the legislation (Regulations EC 1829/2003; EC 1830/2003; Directive EC 18/2001) point of view. The Preliminary Hazard Analysis and the Fault Tree Analysis were used to analyze and predict the occurring failure modes in a food chain system (corn curls processing plant), based on the functions, characteristics, and/or interactions of the ingredients or the processes, upon which the system depends. Critical Control points have been identified and implemented in the cause and effect diagram (also known as Ishikawa, tree diagram, and the fishbone diagram). Finally, Pareto diagrams were employed towards the optimization of GMOs detection potential of FMEA. PMID:17457722

  6. [Application of the thermoelastic stress imaging method to prosthodontics. (2) Basic study of the stress field of artificial molar teeth, in which the existence of saliva was considered].

    PubMed

    Shirono, T; Sato, S; Sonoda, K; Hasegawa, Y; Kobayashi, K; Hyodo, K; Tateishi, T

    1990-06-01

    A basic study was conducted utilizing a thermoelastic stress imaging method for stress analysis of model of simplified artificial molars based on an interocclusal contact relationship. This involved examining the effect of artificial saliva application on a stress field in a situation where occlusal pressure was applied in a dynamic sliding movement. As a result, the following conclusions were obtained. 1. The thermoelastic stress imaging method allowed the stress field to be determined artificial saliva application at distributed load due to plane contact in dynamic sliding movement. 2. Compared with the case of non-saliva application, in a squaremodel having a sliding movement and to which artificial saliva was applied, the pattern of the high compressive stress area was found to be a circle or an ellipsoid. This showed a slight dispersion trend at 10 degrees, with the contact plane as the boundary, and the dispersion of stress concentration began to become clearer at 20; stress concentration on the contact plane tended to disappear at 30 degrees, and sliding was conspicuous and determination impossible at 45 degrees. 3. Results showed that 10 degrees was a transition angle at which a different aspect was shown, representing a trend in a stress field pattern change accompanying an increase in the facet bevel angle when artificial saliva was applied. 4. From the results of stress analysis using the square-shape sliding movement model to which artificial saliva was applied, 10 degrees to 20 degrees of facet bevel of artificial molars was considered preferable in consideration of the presence of saliva. PMID:2135616

  7. Mode decomposition evolution equations

    PubMed Central

    Wang, Yang; Wei, Guo-Wei; Yang, Siyang

    2011-01-01

    Partial differential equation (PDE) based methods have become some of the most powerful tools for exploring the fundamental problems in signal processing, image processing, computer vision, machine vision and artificial intelligence in the past two decades. The advantages of PDE based approaches are that they can be made fully automatic, robust for the analysis of images, videos and high dimensional data. A fundamental question is whether one can use PDEs to perform all the basic tasks in the image processing. If one can devise PDEs to perform full-scale mode decomposition for signals and images, the modes thus generated would be very useful for secondary processing to meet the needs in various types of signal and image processing. Despite of great progress in PDE based image analysis in the past two decades, the basic roles of PDEs in image/signal analysis are only limited to PDE based low-pass filters, and their applications to noise removal, edge detection, segmentation, etc. At present, it is not clear how to construct PDE based methods for full-scale mode decomposition. The above-mentioned limitation of most current PDE based image/signal processing methods is addressed in the proposed work, in which we introduce a family of mode decomposition evolution equations (MoDEEs) for a vast variety of applications. The MoDEEs are constructed as an extension of a PDE based high-pass filter (Europhys. Lett., 59(6): 814, 2002) by using arbitrarily high order PDE based low-pass filters introduced by Wei (IEEE Signal Process. Lett., 6(7): 165, 1999). The use of arbitrarily high order PDEs is essential to the frequency localization in the mode decomposition. Similar to the wavelet transform, the present MoDEEs have a controllable time-frequency localization and allow a perfect reconstruction of the original function. Therefore, the MoDEE operation is also called a PDE transform. However, modes generated from the present approach are in the spatial or time domain and can be

  8. Realization of single-mode telluride rib waveguides for mid-IR applications between 10 and 20 μm

    NASA Astrophysics Data System (ADS)

    Vigreux, Caroline; Barthélémy, Eléonore; Bastard, Lionel; Broquin, Jean-Emmanuel; Barillot, Marc; Ménard, Stéphane; Parent, Gilles; Pradel, Annie

    2011-08-01

    The feasibility of all-telluride integrated optics devices based on waveguides presenting a single-mode behavior in the spectral range (10-20 μm) is demonstrated. These waveguides are constituted of a several micrometer thick Te82Ge18 film deposited onto a Te75Ge15Ga10 bulk glass substrate by thermal coevaporation and further etched by reactive ion etching under the CHF3/O2/Ar atmosphere. The obtained structures were proven to behave as channel waveguides with a good single-mode transmission over the whole spectral range. These results allowed validating our technological solution for the fabrication of integrated optics modal filters for spatial interferometry.

  9. Research on variational mode decomposition and its application in detecting rub-impact fault of the rotor system

    NASA Astrophysics Data System (ADS)

    Wang, Yanxue; Markert, Richard; Xiang, Jiawei; Zheng, Weiguang

    2015-08-01

    Multi-component extraction is an available method for vibration signal analysis of rotary machinery, so a novel method of rubbing fault diagnosis based on variational mode decomposition (VMD) is proposed. VMD is a newly developed technique for adaptive signal decomposition, which can non-recursively decompose a multi-component signal into a number of quasi-orthogonal intrinsic mode functions. The equivalent filtering characteristics of VMD are investigated, and the behavior of wavelet packet-like expansion is first found based on fractional Gaussian noise via numerical simulations. VMD is then applied to detect multiple rubbing-caused signatures for rotor-stator fault diagnosis via numerical simulated response signal and practical vibration signal. A comparison has also been conducted to evaluate the effectiveness of identifying the rubbing-caused signatures by using VMD, empirical wavelet transform (EWT), EEMD and EMD. The analysis results of the rubbing signals show that the multiple features can be better extracted with the VMD, simultaneously.

  10. Sliding mode observer based incipient sensor fault detection with application to high-speed railway traction device.

    PubMed

    Zhang, Kangkang; Jiang, Bin; Yan, Xing-Gang; Mao, Zehui

    2016-07-01

    This paper considers incipient sensor fault detection issue for a class of nonlinear systems with "observer unmatched" uncertainties. A particular fault detection sliding mode observer is designed for the augmented system formed by the original system and incipient sensor faults. The designed parameters are obtained using LMI and line filter techniques to guarantee that the generated residuals are robust to uncertainties and that sliding motion is not destroyed by faults. Then, three levels of novel adaptive thresholds are proposed based on the reduced order sliding mode dynamics, which effectively improve incipient sensor faults detectability. Case study of on the traction system in China Railway High-speed is presented to demonstrate the effectiveness of the proposed incipient senor faults detection schemes. PMID:27156675

  11. Application of ISO22000 and Failure Mode and Effect Analysis (fmea) for Industrial Processing of Poultry Products

    NASA Astrophysics Data System (ADS)

    Varzakas, Theodoros H.; Arvanitoyannis, Ioannis S.

    Failure Mode and Effect Analysis (FMEA) model has been applied for the risk assessment of poultry slaughtering and manufacturing. In this work comparison of ISO22000 analysis with HACCP is carried out over poultry slaughtering, processing and packaging. Critical Control points and Prerequisite programs (PrPs) have been identified and implemented in the cause and effect diagram (also known as Ishikawa, tree diagram and fishbone diagram).

  12. Closed-loop ARS mode for scanning ion conductance microscopy with improved speed and stability for live cell imaging applications

    NASA Astrophysics Data System (ADS)

    Jung, Goo-Eun; Noh, Hanaul; Shin, Yong Kyun; Kahng, Se-Jong; Baik, Ku Youn; Kim, Hong-Bae; Cho, Nam-Joon; Cho, Sang-Joon

    2015-06-01

    Scanning ion conductance microscopy (SICM) is an increasingly useful nanotechnology tool for non-contact, high resolution imaging of live biological specimens such as cellular membranes. In particular, approach-retract-scanning (ARS) mode enables fast probing of delicate biological structures by rapid and repeated approach/retraction of a nano-pipette tip. For optimal performance, accurate control of the tip position is a critical issue. Herein, we present a novel closed-loop control strategy for the ARS mode that achieves higher operating speeds with increased stability. The algorithm differs from that of most conventional (i.e., constant velocity) approach schemes as it includes a deceleration phase near the sample surface, which is intended to minimize the possibility of contact with the surface. Analysis of the ion current and tip position demonstrates that the new mode is able to operate at approach speeds of up to 250 μm s-1. As a result of the improved stability, SICM imaging with the new approach scheme enables significantly improved, high resolution imaging of subtle features of fixed and live cells (e.g., filamentous structures & membrane edges). Taken together, the results suggest that optimization of the tip approach speed can substantially improve SICM imaging performance, further enabling SICM to become widely adopted as a general and versatile research tool for biological studies at the nanoscale level.

  13. Controlling chaotic oscillation modes in visible semiconductor lasers by external light input and its applications to novel optical communications

    NASA Astrophysics Data System (ADS)

    Inagaki, Kouta; Fujita, Masato; Sasaki, Wakao

    2000-11-01

    We have demonstrated a simple method for controlling the nonlinear oscillations using only semiconductor lasers and photodetectors. An electro-optical NDFS (nonlinear delayed feedback system) has been composed by making use of this method. With this system, multi-stable oscillations and chaotic transitions with various patterns have been observed. In addition, some characteristic routing sequences form period-doubling bifurcation to chaos have been reproducibly observed when some external modulations with acoustic frequencies are applied to the NDFS. In this case, we have proved that the harmonic numbers of the multi- stable oscillation modes to appear as system output are to be controlled in terms of timing (phase) as well as frequencies of external input signals at the moment they are applied. And we have also confirmed such remarkable transition behaviors of the multi-stable oscillation modes by numerical analysis based on nonlinear delayed differential equations describing our NDFS. Consequently, we have demonstrated that the oscillation harmonic numbers can be directly chosen from the 1st order up to the 9th by setting the frequencies of the external input signals to be their characteristic values specifying the desired harmonic numbers to appear for output and also by setting the timing of input signals with respect to the phase of original waveform of the oscillating modes. Thus, our system is expected to be a potential for something novel, intelligent communication technique based on chaos.

  14. An adaptively fast ensemble empirical mode decomposition method and its applications to rolling element bearing fault diagnosis

    NASA Astrophysics Data System (ADS)

    Xue, Xiaoming; Zhou, Jianzhong; Xu, Yanhe; Zhu, Wenlong; Li, Chaoshun

    2015-10-01

    Ensemble empirical mode decomposition (EEMD) represents a significant improvement over the original empirical mode decomposition (EMD) method for eliminating the mode mixing problem. However, the added white noises generate some tough problems including the high computational cost, the determination of the two critical parameters (the amplitude of the added white noise and the number of ensemble trials), and the contamination of the residue noise in the signal reconstruction. To solve these problems, an adaptively fast EEMD (AFEEMD) method combined with complementary EEMD (CEEMD) is proposed in this paper. In the proposed method, the two critical parameters are respectively fixed as 0.01 times standard deviation of the original signal and two ensemble trials. Instead, the upper frequency limit of the added white noise is the key parameter which needs to be prescribed beforehand. Unlike the original EEMD method, only two high-frequency white noises are added to the signal to be investigated with anti-phase in AFEEMD. Furthermore, an index termed relative root-mean-square error is employed for the adaptive selection of the proper upper frequency limit of the added white noises. Simulation test and vibration signals based fault diagnosis of rolling element bearing under different fault types are utilized to demonstrate the feasibility and effectiveness of the proposed method. The analysis results indicate that the AFEEMD method represents a sound improvement over the original EEMD method, and has strong practicability.

  15. Development and Application of Benchmark Examples for Mixed-Mode I/II Quasi-Static Delamination Propagation Predictions

    NASA Technical Reports Server (NTRS)

    Krueger, Ronald

    2012-01-01

    The development of benchmark examples for quasi-static delamination propagation prediction is presented. The example is based on a finite element model of the Mixed-Mode Bending (MMB) specimen for 50% mode II. The benchmarking is demonstrated for Abaqus/Standard, however, the example is independent of the analysis software used and allows the assessment of the automated delamination propagation prediction capability in commercial finite element codes based on the virtual crack closure technique (VCCT). First, a quasi-static benchmark example was created for the specimen. Second, starting from an initially straight front, the delamination was allowed to propagate under quasi-static loading. Third, the load-displacement as well as delamination length versus applied load/displacement relationships from a propagation analysis and the benchmark results were compared, and good agreement could be achieved by selecting the appropriate input parameters. The benchmarking procedure proved valuable by highlighting the issues associated with choosing the input parameters of the particular implementation. Overall, the results are encouraging, but further assessment for mixed-mode delamination fatigue onset and growth is required.

  16. Application of Failure Mode and Effect Analysis (FMEA) and cause and effect analysis in conjunction with ISO 22000 to a snails (Helix aspersa) processing plant; A case study.

    PubMed

    Arvanitoyannis, Ioannis S; Varzakas, Theodoros H

    2009-08-01

    Failure Mode and Effect Analysis (FMEA) has been applied for the risk assessment of snails manufacturing. A tentative approach of FMEA application to the snails industry was attempted in conjunction with ISO 22000. Preliminary Hazard Analysis was used to analyze and predict the occurring failure modes in a food chain system (snails processing plant), based on the functions, characteristics, and/or interactions of the ingredients or the processes, upon which the system depends. Critical Control points have been identified and implemented in the cause and effect diagram (also known as Ishikawa, tree diagram, and fishbone diagram). In this work a comparison of ISO22000 analysis with HACCP is carried out over snails processing and packaging. However, the main emphasis was put on the quantification of risk assessment by determining the RPN per identified processing hazard. Sterilization of tins, bioaccumulation of heavy metals, packaging of shells and poisonous mushrooms, were the processes identified as the ones with the highest RPN (280, 240, 147, 144, respectively) and corrective actions were undertaken. Following the application of corrective actions, a second calculation of RPN values was carried out leading to considerably lower values (below the upper acceptable limit of 130). It is noteworthy that the application of Ishikawa (Cause and Effect or Tree diagram) led to converging results thus corroborating the validity of conclusions derived from risk assessment and FMEA. Therefore, the incorporation of FMEA analysis within the ISO22000 system of a snails processing industry is considered imperative. PMID:19582641

  17. The complex mixed Wentzel–Kramers–Brillouin-full-wave approach and its application to the two dimensional mode structure analysis of ion temperature gradient/collisionless trapped electron mode drift waves

    SciTech Connect

    Lu, Z. X.

    2015-05-15

    The complex mixed Wentzel–Kramers–Brillouin (WKB)-full-wave approach is applied to the 2D mode structure analysis of ion temperature gradient/collisionless trapped electron mode drift waves in tokamak plasmas. The parallel mode structure is calculated with the full-wave approach, while the radial envelope is calculated with the complex WKB method. The tilting of the global mode structure along radius is demonstrated analytically. The effects of the phase and amplitude variation of the radial envelope on the parallel mode structure are included in terms of a complex radial wave vector in the parallel mode equation. It is shown that the radial equilibrium non-uniformity leads to the asymmetry of the parallel mode structure not only in configuration space but also in spectrum space. The mixed approach provides a practical way to analyze the asymmetric component of the global mode structure due to radial equilibrium non-uniformity.

  18. The complex mixed Wentzel-Kramers-Brillouin-full-wave approach and its application to the two dimensional mode structure analysis of ion temperature gradient/collisionless trapped electron mode drift waves

    NASA Astrophysics Data System (ADS)

    Lu, Z. X.

    2015-05-01

    The complex mixed Wentzel-Kramers-Brillouin (WKB)-full-wave approach is applied to the 2D mode structure analysis of ion temperature gradient/collisionless trapped electron mode drift waves in tokamak plasmas. The parallel mode structure is calculated with the full-wave approach, while the radial envelope is calculated with the complex WKB method. The tilting of the global mode structure along radius is demonstrated analytically. The effects of the phase and amplitude variation of the radial envelope on the parallel mode structure are included in terms of a complex radial wave vector in the parallel mode equation. It is shown that the radial equilibrium non-uniformity leads to the asymmetry of the parallel mode structure not only in configuration space but also in spectrum space. The mixed approach provides a practical way to analyze the asymmetric component of the global mode structure due to radial equilibrium non-uniformity.

  19. Does Unconscious Racism Exist?

    ERIC Educational Resources Information Center

    Quillian, Lincoln

    2008-01-01

    This essay argues for the existence of a form of unconscious racism. Research on implicit prejudice provides good evidence that most persons have deeply held negative associations with minority groups that can lead to subtle discrimination without conscious awareness. The evidence for implicit attitudes is briefly reviewed. Criticisms of the…

  20. Understanding existing exposure situations.

    PubMed

    Lecomte, J-F

    2016-06-01

    International Commission on Radiological Protection (ICRP) Publication 103 removed the distinction between practices and interventions, and introduced three types of exposure situation: existing, planned, and emergency. It also emphasised the optimisation principle in connection with individual dose restrictions for all controllable exposure situations. Existing exposure situations are those resulting from sources, natural or man-made, that already exist when a decision on control has to be taken. They have common features to be taken into account when implementing general recommendations, such as: the source may be difficult to control; all exposures cannot be anticipated; protective actions can only be implemented after characterisation of the exposure situation; time may be needed to reduce exposure below the reference level; levels of exposure are highly dependent on individual behaviour and present a wide spread of individual dose distribution; exposures at work may be adventitious and not considered as occupational exposure; there is generally no potential for accident; many stakeholders have to be involved; and many factors need to be considered. ICRP is currently developing a series of reports related to the practical implementation of Publication 103 to various existing exposure situations, including exposure from radon, exposure from cosmic radiation in aviation, exposure from processes using naturally occurring radioactive material, and exposure from contaminated sites due to past activities. PMID:26975365

  1. A detailed analysis of the energy levels configuration existing in the band gap of supersaturated silicon with titanium for photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Pérez, E.; Dueñas, S.; Castán, H.; García, H.; Bailón, L.; Montero, D.; García-Hernansanz, R.; García-Hemme, E.; Olea, J.; González-Díaz, G.

    2015-12-01

    The energy levels created in supersaturated n-type silicon substrates with titanium implantation in the attempt to create an intermediate band in their band-gap are studied in detail. Two titanium ion implantation doses (1013 cm-2 and 1014 cm-2) are studied in this work by conductance transient technique and admittance spectroscopy. Conductance transients have been measured at temperatures of around 100 K. The particular shape of these transients is due to the formation of energy barriers in the conduction band, as a consequence of the band-gap narrowing induced by the high titanium concentration. Moreover, stationary admittance spectroscopy results suggest the existence of different energy level configuration, depending on the local titanium concentration. A continuum energy level band is formed when titanium concentration is over the Mott limit. On the other hand, when titanium concentration is lower than the Mott limit, but much higher than the donor impurity density, a quasi-continuum energy level distribution appears. Finally, a single deep center appears for low titanium concentration. At the n-type substrate, the experimental results obtained by means of thermal admittance spectroscopy at high reverse bias reveal the presence of single levels located at around Ec-425 and Ec-275 meV for implantation doses of 1013 cm-2 and 1014 cm-2, respectively. At low reverse bias voltage, quasi-continuously distributed energy levels between the minimum of the conduction bands, Ec and Ec-450 meV, are obtained for both doses. Conductance transients detected at low temperatures reveal that the high impurity concentration induces a band gap narrowing which leads to the formation of a barrier in the conduction band. Besides, the relationship between the activation energy and the capture cross section values of all the energy levels fits very well to the Meyer-Neldel rule. As it is known, the Meyer-Neldel rule typically appears in processes involving multiple excitations, like

  2. A detailed analysis of the energy levels configuration existing in the band gap of supersaturated silicon with titanium for photovoltaic applications

    SciTech Connect

    Pérez, E.; Dueñas, S.; Castán, H.; García, H.; Bailón, L.; Montero, D.; García-Hernansanz, R.; García-Hemme, E.; González-Díaz, G.; Olea, J.

    2015-12-28

    The energy levels created in supersaturated n-type silicon substrates with titanium implantation in the attempt to create an intermediate band in their band-gap are studied in detail. Two titanium ion implantation doses (10{sup 13 }cm{sup -2} and 10{sup 14 }cm{sup -2}) are studied in this work by conductance transient technique and admittance spectroscopy. Conductance transients have been measured at temperatures of around 100 K. The particular shape of these transients is due to the formation of energy barriers in the conduction band, as a consequence of the band-gap narrowing induced by the high titanium concentration. Moreover, stationary admittance spectroscopy results suggest the existence of different energy level configuration, depending on the local titanium concentration. A continuum energy level band is formed when titanium concentration is over the Mott limit. On the other hand, when titanium concentration is lower than the Mott limit, but much higher than the donor impurity density, a quasi-continuum energy level distribution appears. Finally, a single deep center appears for low titanium concentration. At the n-type substrate, the experimental results obtained by means of thermal admittance spectroscopy at high reverse bias reveal the presence of single levels located at around E{sub c}-425 and E{sub c}-275 meV for implantation doses of 10{sup 13 }cm{sup −2} and 10{sup 14 }cm{sup −2}, respectively. At low reverse bias voltage, quasi-continuously distributed energy levels between the minimum of the conduction bands, E{sub c} and E{sub c}-450 meV, are obtained for both doses. Conductance transients detected at low temperatures reveal that the high impurity concentration induces a band gap narrowing which leads to the formation of a barrier in the conduction band. Besides, the relationship between the activation energy and the capture cross section values of all the energy levels fits very well to the Meyer-Neldel rule. As it is known

  3. Application of real-time B-mode ultrasound in posterior decompression and reduction for thoracolumbar burst fracture.

    PubMed

    Yang, Wu-Peng; Wang, Zhe; Feng, Nai-Qi; Wang, Chun-Mei; DU, Shao-Long

    2013-10-01

    This study aimed to investigate the role of real-time B-mode ultrasound in posterior decompression and reduction and to observe the signal changes in spinal cord blood flow in a thoracolumbar burst fracture (TBF). Between February 2004 and December 2008, 138 patients with TBF were divided into group A (108 cases) and group B (30 cases). In group A, under the assistance of real-time B-mode ultrasound, posterior decompression and fracture piece reduction were performed, and we observed the signal changes in spinal cord blood flow. In group B, posterior fenestration was combined with pushing the fracture piece into the fractured vertebral body using an L-shaped operative tool. Presurgical and postsurgical recovery of neurological function was evaluated according to American Spinal Injury Association (ASIA) standards, and the range of spinal decompression was determined by measuring the proportion of encroached fracture piece in the spinal canal (spinal stenosis rate) on the computed tomography (CT) image. In group A, 12 patients had a grade A spinal injury according to the Frankel grading system, and there were six cases without neurological recovery. In the other patients, neurological function increased by 1-3 grades. There were no aggravated spinal cord injuries or other serious complications. In group B, three patients were categorized as grade A and there were two cases without neurological recovery. In the other patients, neurological function increased by 1-3 grades. In groups A and B, the postsurgical spinal stenosis rate was significantly lower than the presurgical stenosis rate (P<0.05). The postsurgical spinal stenosis rate in group B was significantly higher compared with group A (P<0.05). There was no significant difference in neurological function recovery between the groups (P>0.05). Real-time B-mode ultrasound is an effective method for posterior decompression and reduction and to observe signal changes in spinal cord blood flow in TBF. PMID:24137306

  4. Application of real-time B-mode ultrasound in posterior decompression and reduction for thoracolumbar burst fracture

    PubMed Central

    YANG, WU-PENG; WANG, ZHE; FENG, NAI-QI; WANG, CHUN-MEI; DU, SHAO-LONG

    2013-01-01

    This study aimed to investigate the role of real-time B-mode ultrasound in posterior decompression and reduction and to observe the signal changes in spinal cord blood flow in a thoracolumbar burst fracture (TBF). Between February 2004 and December 2008, 138 patients with TBF were divided into group A (108 cases) and group B (30 cases). In group A, under the assistance of real-time B-mode ultrasound, posterior decompression and fracture piece reduction were performed, and we observed the signal changes in spinal cord blood flow. In group B, posterior fenestration was combined with pushing the fracture piece into the fractured vertebral body using an L-shaped operative tool. Presurgical and postsurgical recovery of neurological function was evaluated according to American Spinal Injury Association (ASIA) standards, and the range of spinal decompression was determined by measuring the proportion of encroached fracture piece in the spinal canal (spinal stenosis rate) on the computed tomography (CT) image. In group A, 12 patients had a grade A spinal injury according to the Frankel grading system, and there were six cases without neurological recovery. In the other patients, neurological function increased by 1–3 grades. There were no aggravated spinal cord injuries or other serious complications. In group B, three patients were categorized as grade A and there were two cases without neurological recovery. In the other patients, neurological function increased by 1–3 grades. In groups A and B, the postsurgical spinal stenosis rate was significantly lower than the presurgical stenosis rate (P<0.05). The postsurgical spinal stenosis rate in group B was significantly higher compared with group A (P<0.05). There was no significant difference in neurological function recovery between the groups (P>0.05). Real-time B-mode ultrasound is an effective method for posterior decompression and reduction and to observe signal changes in spinal cord blood flow in TBF. PMID

  5. Preparation, characterization and application of a reversed phase liquid chromatography/hydrophilic interaction chromatography mixed-mode C18-DTT stationary phase.

    PubMed

    Wang, Qing; Long, Yao; Yao, Lin; Xu, Li; Shi, Zhi-Guo; Xu, Lanying

    2016-01-01

    A mixed-mode chromatographic stationary phase, C18-DTT (dithiothreitol) silica (SiO2) was prepared through "thiol-ene" click chemistry. The obtained material was characterized by fourier transform infrared spectroscope, nitrogen adsorption analysis and contact angle analysis. Chromatographic performance of the C18-DTT was systemically evaluated by studying the effect of acetonitrile content, pH, buffer concentration of the mobile phase and column temperature. It was demonstrated that the novel stationary phase possessed reversed phase liquid chromatography (RPLC)/hydrophilic interaction liquid chromatography (HILIC) mixed-mode property. The stop-flow test revealed that C18-DTT exhibited excellent compatibility with 100% aqueous mobile phase. Additionally, the stability and column-to-column reproducibility of the C18-DTT material were satisfactory, with relative standard deviations of retention factor of the tested analytes (verapamil, fenbufen, guanine, tetrandrine and nicotinic acid) in the range of 1.82-3.72% and 0.85-1.93%, respectively. Finally, the application of C18-DTT column was demonstrated in the separation of non-steroidal anti-inflammatory drugs, aromatic carboxylic acids, alkaloids, nucleo-analytes and polycyclic aromatic hydrocarbons. It had great resolving power in the analysis of various compounds in HILIC and RPLC chromatographic conditions and was a promising RPLC/HILIC mixed-mode stationary phase. PMID:26695288

  6. Pulsed and CW adjustable 1942 nm single-mode all-fiber Tm-doped fiber laser system for surgical laser soft tissue ablation applications.

    PubMed

    Huang, Yize; Jivraj, Jamil; Zhou, Jiaqi; Ramjist, Joel; Wong, Ronnie; Gu, Xijia; Yang, Victor X D

    2016-07-25

    A surgical laser soft tissue ablation system based on an adjustable 1942 nm single-mode all-fiber Tm-doped fiber laser operating in pulsed or CW mode with nitrogen assistance is demonstrated. Ex vivo ablation on soft tissue targets such as muscle (chicken breast) and spinal cord (porcine) with intact dura are performed at different ablation conditions to examine the relationship between the system parameters and ablation outcomes. The maximum laser average power is 14.4 W, and its maximum peak power is 133.1 W with 21.3 μJ pulse energy. The maximum CW power density is 2.33 × 106 W/cm2 and the maximum pulsed peak power density is 2.16 × 107 W/cm2. The system parameters examined include the average laser power in CW or pulsed operation mode, gain-switching frequency, total ablation exposure time, and the input gas flow rate. The ablation effects were measured by microscopy and optical coherence tomography (OCT) to evaluate the ablation depth, superficial heat-affected zone diameter (HAZD) and charring diameter (CD). Our results conclude that the system parameters can be tailored to meet different clinical requirements such as ablation for soft tissue cutting or thermal coagulation for future applications of hemostasis. PMID:27464121

  7. Application of UPLC-QTOF-MS in MS(E) mode for the rapid and precise identification of alkaloids in goldenseal (Hydrastis canadensis).

    PubMed

    Le, Phuong Mai; McCooeye, Margaret; Windust, Anthony

    2014-02-01

    Here, we describe a new application of ultra-performance liquid chromatography coupled with an electrospray ionization quadrupole time-of-flight mass spectrometry operating in MS(E) mode (UPLC-QTOF-MS(E)) for the sensitive, fast, and effective characterization of alkaloids in goldenseal (Hydrastis canadensis). This approach allowed identification of alkaloids using a cyclic low and high collision energy spectral acquisition mode providing simultaneous accurate precursor and fragment ion mass information. A total of 45 compounds were separated and 40 of them characterized including one new compound and 7 identified for the first time in goldenseal. The spectral data obtained using this method is comparable to those obtained by conventional LC-MS(n). However, the UPLC-QTOF-MS(E) method offers high chromatographic resolution with structural characterization facilitated by accurate mass measurement in both MS and MS/MS modes in a single analytical run; this makes it suitable for the rapid analysis and screening of alkaloids in plant extracts. PMID:24390410

  8. Separation of crack extension modes in composite delamination problems

    SciTech Connect

    Beuth, J.L.; Narayan, S.H.

    1997-12-31

    In the analysis of composite delamination problems, the magnitudes of Mode 1 and Mode 2 stress intensity factors or energy release rates are typically not unique, due to oscillatory behavior of near-tip stresses and displacements. This behavior currently limits the ability to consistently apply interfacial fracture mechanics to predict composite delamination. The virtual crack closure technique (VCCT) is a method used to extract Mode 1 and Mode 2 components of energy release rates from finite element fracture models. Energy release rate components extracted from an oscillatory delamination model using the VCCT are dependent on the virtual crack extension length, {Delta}. In this paper, a recently-developed modified VCCT from the literature is used to extract {Delta}-independent energy release rate quantities for composite delamination problems where the delamination occurs between two plies or ply groups modeled as in-plane orthotropic materials. Numerical cases studied are taken from existing work in the literature. For the cases studied, results show that mode mix values resulting from application of the modified VCCT are comparable to those obtained via existing methods. Some mode mix predictions obtained (in the literature) using existing methods lie outside the range of reasonable values for such problems, however. The {Delta}-independent energy release rate quantities extracted using the modified VCCT can serve as guides for testing the convergence of finite element models. This technique also has potential as a consistent method for extracting energy release rate quantities from numerical models of composite delamination.

  9. Nonlinear mode coupling in whispering-gallery-mode resonators

    NASA Astrophysics Data System (ADS)

    D'Aguanno, Giuseppe; Menyuk, Curtis R.

    2016-04-01

    We present a first-principles derivation of the coupled nonlinear Schrödinger equations that govern the interaction between two families of modes with different transverse profiles in a generic whispering-gallery-mode resonator. We find regions of modulational instability and the existence of trains of bright solitons in both the normal and the anomalous dispersion regime.

  10. Existence of hyperbolic calorons

    PubMed Central

    Sibner, Lesley; Sibner, Robert; Yang, Yisong

    2015-01-01

    Recent work of Harland shows that the SO(3)-symmetric, dimensionally reduced, charge-N self-dual Yang–Mills calorons on the hyperbolic space H3×S1 may be obtained through constructing N-vortex solutions of an Abelian Higgs model as in the study of Witten on multiple instantons. In this paper, we establish the existence of such minimal action charge-N calorons by constructing arbitrarily prescribed N-vortex solutions of the Witten type equations.

  11. Application of high-resolution linear Radon transform for Rayleigh-wave dispersive energy imaging and mode separating

    USGS Publications Warehouse

    Luo, Y.; Xia, J.; Miller, R.D.; Liu, J.; Xu, Y.; Liu, Q.

    2008-01-01

    Multichannel Analysis of Surface Waves (MASW) analysis is an efficient tool to obtain the vertical shear-wave profile. One of the key steps in the MASW method is to generate an image of dispersive energy in the frequency-velocity domain, so dispersion curves can be determined by picking peaks of dispersion energy. In this paper, we image Rayleigh-wave dispersive energy and separate multimodes from a multichannel record by high-resolution linear Radon transform (LRT). We first introduce Rayleigh-wave dispersive energy imaging by high-resolution LRT. We then show the process of Rayleigh-wave mode separation. Results of synthetic and real-world examples demonstrate that (1) compared with slant stacking algorithm, high-resolution LRT can improve the resolution of images of dispersion energy by more than 50% (2) high-resolution LRT can successfully separate multimode dispersive energy of Rayleigh waves with high resolution; and (3) multimode separation and reconstruction expand frequency ranges of higher mode dispersive energy, which not only increases the investigation depth but also provides a means to accurately determine cut-off frequencies.

  12. External cavity based single mode Fabry-Pérot laser diode and its application towards all-optical digital circuits

    NASA Astrophysics Data System (ADS)

    Nakarmi, Bikash; Zhang, Xuping; Won, Yong Hyub

    2012-11-01

    We have proposed a novel approach of realizing all-optical logic gates and combinational circuit using external cavity based single mode Fabry-Pérot laser diodes (SMFP-LDs). Different techniques and critical parameters for injection locking the any one of the modes of SMFP-LDs are discussed. Taking consideration of wavelength detuning and input injected power, we have proposed and demonstrated multi-input injection locking, supporting beam injection locking with the conventional injection locking which are used for demonstrating different logic gates (NAND, AND, XNOR, XOR, NOT, NOR) and digital circuits (Half adder and Comparator). Since we have used SMFP-LDs, there is no requirement of additional probe beam and associated components as required by other optical technologies making the realization simple in configuration, cost effective and power efficient. Clear output waveforms, eye diagrams, risingfalling times and BER are presented to verify the proposed method. All-optical logic units and digital circuit are demonstrated at the data rate of 10 Gbps with the waveform of NRZ signal waveform and measured eye diagram and BER of the PRBS of 231-1 signal. The maximum power penalty among all demonstrated units is below 1.4 dB at the BER of 10-9.

  13. Application of Nonstationary Sliding Mode Control to Suppression of Transverse Vibration of Elevator Rope Using Input Device with Gaps

    NASA Astrophysics Data System (ADS)

    Otsuki, Masatsugu; Ushijima, Yumiko; Yoshida, Kazuo; Kimura, Hiroyuki; Nakagawa, Toshiaki

    Transverse vibrations of ropes spanning a high-speed elevator are induced by resonance when a building sways because of an earthquake or wind force. Hence, an effective solution is demanded. In this study, we undertake to suppress the vibration of an elevator rope by using an input device placed in the vicinity of the upper boundary of the rope. This input device has gaps between an actuator and the rope to prevent the progression of their abrasion. A nonstationary control method is effective for the control of a time-varying system with which an elevator rope and a crane wire are categorized. In addition, a sliding mode controller is robust toward nonlinearity at the position where input is introduced. Thus, in this paper, we present a method of vibration control for the elevator rope, which is based on the nonstationary sliding mode control method using the input device with gaps. The effectiveness and robustness of the proposed controller are examined by numerical calculation that simulates input saturation, stroke limitation, gap-width expansion, and varying parameters, in the presence of model errors of the elevator rope. The results indicate effective vibration suppression and high robustness in the above cases except for the case of varying parameters.

  14. Electromagnetic resonance modes on a two-dimensional tandem grating and its application for broadband absorption in the visible spectrum.

    PubMed

    Han, Sunwoo; Lee, Bong Jae

    2016-01-25

    In this work, we numerically investigate the electromagnetic resonances on two-dimensional tandem grating structures. The base of a tandem grating consists of an opaque Au substrate, a SiO(2) spacer, and a Au grating (concave type); that is, a well-known fishnet structure forming Au/SiO(2)/Au stack. A convex-type Au grating (i.e., topmost grating) is then attached on top of the base fishnet structure with or without additional SiO(2) spacer, resulting in two types of tandem grating structures. In order to calculate the spectral reflectance and local magnetic field distribution, the finite-difference time-domain method is employed. When the topmost Au grating is directly added onto the base fishnet structure, the surface plasmon and magnetic polariton in the base structure are branched out due to the geometric asymmetry with respect to the SiO(2) spacer. If additional SiO(2) spacer is added between the topmost Au grating and the base fishnet structure, new magnetic resonance modes appear due to coupling between two vertically aligned Au/SiO(2)/Au stacks. With the understanding of multiple electromagnetic resonance modes on the proposed tandem grating structures, we successfully design a broadband absorber made of Au and SiO(2) in the visible spectrum. PMID:26832574

  15. Joint application of a statistical optimization process and Empirical Mode Decomposition to Magnetic Resonance Sounding Noise Cancelation

    NASA Astrophysics Data System (ADS)

    Ghanati, Reza; Fallahsafari, Mahdi; Hafizi, Mohammad Kazem

    2014-12-01

    The signal quality of Magnetic Resonance Sounding (MRS) measurements is a crucial criterion. The accuracy of the estimation of the signal parameters (i.e. E0 and T2*) strongly depends on amplitude and conditions of ambient electromagnetic interferences at the site of investigation. In this paper, in order to enhance the performance in the noisy environments, a two-step noise cancelation approach based on the Empirical Mode Decomposition (EMD) and a statistical method is proposed. In the first stage, the noisy signal is adaptively decomposed into intrinsic oscillatory components called intrinsic mode functions (IMFs) by means of the EMD algorithm. Afterwards based on an automatic procedure the noisy IMFs are detected, and then the partly de-noised signal is reconstructed through the no-noise IMFs. In the second stage, the signal obtained from the initial section enters an optimization process to cancel the remnant noise, and consequently, estimate the signal parameters. The strategy is tested on a synthetic MRS signal contaminated with Gaussian noise, spiky events and harmonic noise, and on real data. By applying successively the proposed steps, we can remove the noise from the signal to a high extent and the performance indexes, particularly signal to noise ratio, will increase significantly.

  16. Fully compatible magneto-optical sol-gel material with glass waveguides technologies: application to mode converters

    NASA Astrophysics Data System (ADS)

    Royer, François; Jamon, Damien; Broquin, Jean-Emmanuel; Amata, Hadi; Kekesi, Renata; Neveu, Sophie; Blanc-Mignon, Marie-Françoise; Ghibaudo, Elise

    2011-01-01

    To overcome the difficult problem of the integration of magneto-optical materials with classical technologies, our group has developped a composite magneto-optical material made of a hybrid organic-inorganic silica type matrix doped by magnetic nanoparticles. Thin films of this material are obtained through a soft chemistry sol-gel process which gives a full compatibility with an integration on glass substarte. Due to an interesting magneto optical activity (Faraday rotation of 310°/cm) several magneto-optical functionnalities have been realized. A thin film of such composite material coated on a pyrex™ substrate acts as non-reciprocal TE/TM mode converter. An hybrid stucture made of a composite film coated on an ion-exchanged glass waveguide has been realized with a good propagation of light through a hybrid mode. Finally, the sol gel process has been adapted in order to obtain 3D inverse opals which should behave as magnetophotonic crystals. Transmittance curves reveal the photonic band gap of such opals doped with magnetic nanoparticles.

  17. Waveform modelling using locked-mode synthetic and differential seismograms: application to determination of the structure of Mexico

    USGS Publications Warehouse

    Gomberg, J.S.; Masters, T. Guy

    1988-01-01

    We have developed algorithms for modelling seismic waveforms to constrain regional Earth structure. The seismogram is represented as a sum of locked-mode travelling waves in a layered medium. This representation is convenient as it allows us to model structures with slowly varying heterogeneity and to construct differential seismograms. Describes the techniques we have implemented that enable us to compute synthetic and differential seismograms in an efficient and stable manner. The computational methods are sufficiently rapid that many modes can be included and in some cases the entire seismogram may be modified. These algorithms are applied to model a set of seismograms of southern Mexican earthquakes recorded in northern Mexico. The frequency bandwidth of these data is centred at 0.067 Hz and we demonstrate that even at these relatively high frequencies, many features of the seismogram can be successfully modelled. Our results suggest that the structure within the recording array in northern Mexico is resolvably different from that to the south. We find that the average shear velocity of the lower lithosphere of southern Mexico is very low, approximately 4.3 km s-1. If the low-velocity region is confined to the Trans Mexican Volcanic Belt, the shear velocities between 20-80 km depth are approximately 3.3 km s-1. This may be correlated with partial melt and is consistent with the active volcanism and high heat flow found in the region. -Authors

  18. Review and Analysis of Existing Mobile Phone Apps to Support Heart Failure Symptom Monitoring and Self-Care Management Using the Mobile Application Rating Scale (MARS)

    PubMed Central

    Maurer, Mathew S; Reading, Meghan; Hiraldo, Grenny; Hickey, Kathleen T; Iribarren, Sarah

    2016-01-01

    Background Heart failure is the most common cause of hospital readmissions among Medicare beneficiaries and these hospitalizations are often driven by exacerbations in common heart failure symptoms. Patient collaboration with health care providers and decision making is a core component of increasing symptom monitoring and decreasing hospital use. Mobile phone apps offer a potentially cost-effective solution for symptom monitoring and self-care management at the point of need. Objective The purpose of this review of commercially available apps was to identify and assess the functionalities of patient-facing mobile health apps targeted toward supporting heart failure symptom monitoring and self-care management. Methods We searched 3 Web-based mobile app stores using multiple terms and combinations (eg, “heart failure,” “cardiology,” “heart failure and self-management”). Apps meeting inclusion criteria were evaluated using the Mobile Application Rating Scale (MARS), IMS Institute for Healthcare Informatics functionality scores, and Heart Failure Society of America (HFSA) guidelines for nonpharmacologic management. Apps were downloaded and assessed independently by 2-4 reviewers, interclass correlations between reviewers were calculated, and consensus was met by discussion. Results Of 3636 potentially relevant apps searched, 34 met inclusion criteria. Most apps were excluded because they were unrelated to heart failure, not in English or Spanish, or were games. Interrater reliability between reviewers was high. AskMD app had the highest average MARS total (4.9/5). More than half of the apps (23/34, 68%) had acceptable MARS scores (>3.0). Heart Failure Health Storylines (4.6) and AskMD (4.5) had the highest scores for behavior change. Factoring MARS, functionality, and HFSA guideline scores, the highest performing apps included Heart Failure Health Storylines, Symple, ContinuousCare Health App, WebMD, and AskMD. Peer-reviewed publications were identified

  19. Stable similariton generation in hybrid mode-locked erbium-doped all-fiber ring laser for application in optical frequency standard

    NASA Astrophysics Data System (ADS)

    Sazonkin, Stanislav G.; Krylov, Alexander A.; Dvoretskiy, Dmitriy A.; Leonov, Stanislav O.; Lazarev, Vladimir A.; Pnev, Alexey B.; Karasik, Valeriy E.; Grebenyukov, Vyacheslav V.; Pozharov, Anatoly S.; Obraztsova, Elena D.

    2015-01-01

    Recently similariton (or self-similar pulse) fiber lasers have attracted great attention due to their capabilities of highenergy pulse generation that could find different applications in science and industry. Moreover it is very important to reach stable pulse generation for the application as a frequency divider in optical frequency standard. Hybrid modelocking mechanism was used for obtaining stable similariton generation at 38 MHz pulse repetition frequency. It involves two types of mode-locking mechanisms in the cavity - saturation of carbon nanostructures absorber (recovery time Trt ~ 500 fs) and nonlinear polarization evolution based on the nonlinear Kerr-effect (Trt ~ 10 fs). It was shown that total intracavity dispersion should be slightly positive for generating stable similaritons with duration of less than 90 fs and spectral bandwidth of more than 50 nm at 11.2 mW output average power that could be further applied in an all-fiber MOPA setup.

  20. Applicability of NASA contract quality management and failure mode effect analysis procedures to the USGS Outer Continental Shelf oil and gas lease management program

    NASA Technical Reports Server (NTRS)

    Dyer, M. K.; Little, D. G.; Hoard, E. G.; Taylor, A. C.; Campbell, R.

    1972-01-01

    An approach that might be used for determining the applicability of NASA management techniques to benefit almost any type of down-to-earth enterprise is presented. A study was made to determine the following: (1) the practicality of adopting NASA contractual quality management techniques to the U.S. Geological Survey Outer Continental Shelf lease management function; (2) the applicability of failure mode effects analysis to the drilling, production, and delivery systems in use offshore; (3) the impact on industrial offshore operations and onshore management operations required to apply recommended NASA techniques; and (4) the probable changes required in laws or regulations in order to implement recommendations. Several management activities that have been applied to space programs are identified, and their institution for improved management of offshore and onshore oil and gas operations is recommended.

  1. SU-E-I-23: Design and Clinical Application of External Marking Body in Multi- Mode Medical Images Registration and Fusion

    SciTech Connect

    Chen, Z; Gong, G

    2014-06-01

    Purpose: To design an external marking body (EMB) that could be visible on computed tomography (CT), magnetic resonance (MR), positron emission tomography (PET) and single-photon emission computed tomography (SPECT) images and to investigate the use of the EMB for multiple medical images registration and fusion in the clinic. Methods: We generated a solution containing paramagnetic metal ions and iodide ions (CT'MR dual-visible solution) that could be viewed on CT and MR images and multi-mode image visible solution (MIVS) that could be obtained by mixing radioactive nuclear material. A globular plastic theca (diameter: 3–6 mm) that mothball the MIVS and the EMB was brought by filling MIVS. The EMBs were fixed on the patient surface and CT, MR, PET and SPECT scans were obtained. The feasibility of clinical application and the display and registration error of EMB among different image modalities were investigated. Results: The dual-visible solution was highly dense on CT images (HU>700). A high signal was also found in all MR scanning (T1, T2, STIR and FLAIR) images, and the signal was higher than subcutaneous fat. EMB with radioactive nuclear material caused a radionuclide concentration area on PET and SPECT images, and the signal of EMB was similar to or higher than tumor signals. The theca with MIVS was clearly visible on all the images without artifact, and the shape was round or oval with a sharp edge. The maximum diameter display error was 0.3 ± 0.2mm on CT and MRI images, and 1.0 ± 0.3mm on PET and SPECT images. In addition, the registration accuracy of the theca center among multi-mode images was less than 1mm. Conclusion: The application of EMB with MIVS improves the registration and fusion accuracy of multi-mode medical images. Furthermore, it has the potential to ameliorate disease diagnosis and treatment outcome.

  2. Characterization and multi-mode liquid chromatographic application of 4-propylaminomethyl benzoic acid bonded silica--a zwitterionic stationary phase.

    PubMed

    Wijekoon, A; Gangoda, M E; Gregory, R B

    2012-12-28

    4-Propylaminomethyl benzoic acid bonded silica (4-PAMBA-silica) was synthesized by reacting aminopropyl modified silica with 4-carboxybenzaldehyde and reducing the resulting Schiff base with sodium cyanoborohydride in situ. The structure of this bonded phase was confirmed by (13)C cross polarization magic angle spinning ((13)C CP MAS) NMR. Elemental analysis indicated a coupling efficiency of about 79%. Chromatographic characterization of a 4-PAMBA-silica stationary phase revealed that at a mobile phase pH of 3.0, basic compounds were unresolved and co-eluted near the void volume, while aromatic sulfonates were retained and were well-resolved. By contrast, at a mobile phase pH of 7.0, the aromatic sulfonates were unresolved and eluted at the void volume, while basic compounds were retained and were well-resolved. To further understand the chromatographic retention mechanism the retention factors for a series of cationic and anionic compounds were measured at pH 7.0 and 3.0 as a function of the charge and concentration of competing ions in the mobile phase. A plot of the logarithm of the retention factor versus the logarithm of the eluent ion concentration was linear with a negative slope that is equal to the ratio of effective charges of the solutes and the eluent ions. This indicates that an ion exchange mechanism contributes to the separation of both cations and anions at pH 7.0 and pH 3.0, respectively. The increase in retention of alkanoic acids with their number of carbons at a mobile phase pH of 7.0 and exclusion of alkanoic acids at a mobile phase pH of 3.0 suggests that an ion exclusion mode and hydrophobic interaction mode are also operational with 4-PAMBA-silica. The amino acids, L-arginine, L-phenylalanine, and L-tyrosine were retained and well-resolved with a mobile phase containing a high concentration of organic solvent. This behavior was further studied by measuring the retention factors of polar and charged compounds as a function of the organic

  3. The EXIST Mission Concept Study

    NASA Technical Reports Server (NTRS)

    Fishman, Gerald J.; Grindlay, J.; Hong, J.

    2008-01-01

    scanning mode, interrupted for several orbits per day by GRB follow-ups, followed by a combined pointing-scanning mission phase for optical/IR spectroscopy and redshifts for the large AGN sample found in the survey as well as GRBs and LSST transients. A Team of university, NASA, and industry investigators will conduct the study to determine the full sensitivity and capabilities of this new configuration for EXIST. It will build on the extensive studies of the prior design for the mission and the HET and will incorporate the optical/IR telescope (hereafter IRT) now fully developed by our ITT partner for the NextView Commercial Remote Sensing mission (early 2008 launch) with a focal plane to be developed at GSFC based in part on JWST/NIRSPEC designs. No new technology is needed for either the IRT or HET instruments. The study will pay close attention to full mission cost and present a design for the Decadal Survey Workshop to ensure this even more capable EXIST mission is once again part of the next Decadal Survey.

  4. Evaluation of the Temperature Stability of a Low-Frequency a0 Mode Transducer Developed for Shm Applications

    NASA Astrophysics Data System (ADS)

    Clarke, T.; Simonetti, F.; Rokhlin, S.; Cawley, P.

    2008-02-01

    A piezoelectric-based transducer generating high purity A0 mode guided waves at low frequencies (around 20 kHz) was developed. Parametric studies were undertaken by varying the backing mass length, the transducer diameter and the thickness of a soft front layer. Results obtained by FEM were validated by experimental measurements and showed that signals with A0/S0 energy ratios substantially above 40 dB can be obtained. The amplitude, phase and frequency stability of signals produced by these transducers and the general robustness of an experimental pitch-catch system were evaluated in an environment subjected to 10 °C temperature shifts. Temperature compensation and baseline subtraction methods were applied to the signals and residual signal amplitude of -38 dB in relation to the amplitude of the first arrival was obtained. Reflections from a weak reflector attached to the plate were identifiable even with a 10 °C temperate change.

  5. Thermal synchrotron radiation from RRMHD simulations of the double tearing mode reconnection - application to the Crab flares

    NASA Astrophysics Data System (ADS)

    Takamoto, M.; Pétri, J.; Baty, H.

    2015-12-01

    We study the magnetohydrodynamic tearing instability occurring in a double current sheet configuration when a guide field is present. This is investigated by means of resistive relativistic magnetohydrodynamic simulations. Following the dynamics of the double tearing mode (DTM), we are able to compute synthetic synchrotron spectra in the explosive reconnection phase. The pulsar-striped wind model represents a site where such current sheets are formed, including a guide field. The variability of the Crab nebula/pulsar system, seen as flares, can be therefore naturally explained by the DTM explosive phase in the striped wind. Our results indicate that the Crab GeV flare can be explained by the DTM in the striped wind region if the magnetization parameter σ is around 105.

  6. Failure modes of valve-regulated lead-acid batteries for electric bicycle applications in deep discharge

    NASA Astrophysics Data System (ADS)

    Guo, Yonglang; Tang, Shengqun; Meng, Gang; Yang, Shijun

    The 36 or 48 V valve-regulated lead-acid (VRLA) battery packs have been widely applied to the power sources of electric bicycles or light electric scooters in China. The failure modes of the 12 V/10 Ah VRLA batteries have been studied by the cycle life test at C 2 discharge rate and 100% depth of discharge (DOD). It indicates that the main cause of the battery failure in this cycle duty is the softening and shedding of positive active mass (PAM) rather than individual water loss, recombination efficiency or sulfation, etc. When the electrolyte saturation falls to a certain extent, the high oxygen recombination current leads to the depolarization of the negative plate and the shift of the positive plate to a higher potential. The violent oxygen evolution accelerates the softening of PAM and the end of cycle life.

  7. Free boundary ballooning mode representation

    SciTech Connect

    Zheng, L. J.

    2012-10-15

    A new type of ballooning mode invariance is found in this paper. Application of this invariance is shown to be able to reduce the two-dimensional problem of free boundary high n modes, such as the peeling-ballooning modes, to a one-dimensional problem. Here, n is toroidal mode number. In contrast to the conventional ballooning representation, which requires the translational invariance of the Fourier components of the perturbations, the new invariance reflects that the independent solutions of the high n mode equations are translationally invariant from one radial interval surrounding a single singular surface to the other intervals. The conventional ballooning mode invariance breaks down at the vicinity of plasma edge, since the Fourier components with rational surfaces in vacuum region are completely different from those with rational surfaces in plasma region. But, the new type of invariance remains valid. This overcomes the limitation of the conventional ballooning mode representation for studying free boundary modes.

  8. Constraining primordial vector mode from B-mode polarization

    SciTech Connect

    Saga, Shohei; Ichiki, Kiyotomo; Shiraishi, Maresuke E-mail: maresuke.shiraishi@pd.infn.it

    2014-10-01

    The B-mode polarization spectrum of the Cosmic Microwave Background (CMB) may be the smoking gun of not only the primordial tensor mode but also of the primordial vector mode. If there exist nonzero vector-mode metric perturbations in the early Universe, they are known to be supported by anisotropic stress fluctuations of free-streaming particles such as neutrinos, and to create characteristic signatures on both the CMB temperature, E-mode, and B-mode polarization anisotropies. We place constraints on the properties of the primordial vector mode characterized by the vector-to-scalar ratio r{sub v} and the spectral index n{sub v} of the vector-shear power spectrum, from the Planck and BICEP2 B-mode data. We find that, for scale-invariant initial spectra, the ΛCDM model including the vector mode fits the data better than the model including the tensor mode. The difference in χ{sup 2} between the vector and tensor models is Δχ{sup 2} = 3.294, because, on large scales the vector mode generates smaller temperature fluctuations than the tensor mode, which is preferred for the data. In contrast, the tensor mode can fit the data set equally well if we allow a significantly blue-tilted spectrum. We find that the best-fitting tensor mode has a large blue tilt and leads to an indistinct reionization bump on larger angular scales. The slightly red-tilted vector mode supported by the current data set can also create O(10{sup -22})-Gauss magnetic fields at cosmological recombination. Our constraints should motivate research that considers models of the early Universe that involve the vector mode.

  9. SU-C-BRD-02: A Team Focused Clinical Implementation and Failure Mode and Effects Analysis of HDR Skin Brachytherapy Using Valencia and Leipzig Surface Applicators

    SciTech Connect

    Sayler, E; Harrison, A; Eldredge-Hindy, H; Dinome, J; Munro, S; Anne, R; Comber, E; Lockamy, V

    2014-06-15

    Purpose: and Leipzig applicators (VLAs) are single-channel brachytherapy surface applicators used to treat skin lesions up to 2cm diameter. Source dwell times can be calculated and entered manually after clinical set-up or ultrasound. This procedure differs dramatically from CT-based planning; the novelty and unfamiliarity could lead to severe errors. To build layers of safety and ensure quality, a multidisciplinary team created a protocol and applied Failure Modes and Effects Analysis (FMEA) to the clinical procedure for HDR VLA skin treatments. Methods: team including physicists, physicians, nurses, therapists, residents, and administration developed a clinical procedure for VLA treatment. The procedure was evaluated using FMEA. Failure modes were identified and scored by severity, occurrence, and detection. The clinical procedure was revised to address high-scoring process nodes. Results: Several key components were added to the clinical procedure to minimize risk probability numbers (RPN): -Treatments are reviewed at weekly QA rounds, where physicians discuss diagnosis, prescription, applicator selection, and set-up. Peer review reduces the likelihood of an inappropriate treatment regime. -A template for HDR skin treatments was established in the clinical EMR system to standardize treatment instructions. This reduces the chances of miscommunication between the physician and planning physicist, and increases the detectability of an error during the physics second check. -A screen check was implemented during the second check to increase detectability of an error. -To reduce error probability, the treatment plan worksheet was designed to display plan parameters in a format visually similar to the treatment console display. This facilitates data entry and verification. -VLAs are color-coded and labeled to match the EMR prescriptions, which simplifies in-room selection and verification. Conclusion: Multidisciplinary planning and FMEA increased delectability and

  10. Application of ISO22000, failure mode, and effect analysis (FMEA) cause and effect diagrams and pareto in conjunction with HACCP and risk assessment for processing of pastry products.

    PubMed

    Varzakas, Theodoros H

    2011-09-01

    The Failure Mode and Effect Analysis (FMEA) model has been applied for the risk assessment of pastry processing. A tentative approach of FMEA application to the pastry industry was attempted in conjunction with ISO22000. Preliminary Hazard Analysis was used to analyze and predict the occurring failure modes in a food chain system (pastry processing plant), based on the functions, characteristics, and/or interactions of the ingredients or the processes, upon which the system depends. Critical Control points have been identified and implemented in the cause and effect diagram (also known as Ishikawa, tree diagram, and fishbone diagram). In this work a comparison of ISO22000 analysis with HACCP is carried out over pastry processing and packaging. However, the main emphasis was put on the quantification of risk assessment by determining the Risk Priority Number (RPN) per identified processing hazard. Storage of raw materials and storage of final products at -18°C followed by freezing were the processes identified as the ones with the highest RPN (225, 225, and 144 respectively) and corrective actions were undertaken. Following the application of corrective actions, a second calculation of RPN values was carried out leading to considerably lower values (below the upper acceptable limit of 130). It is noteworthy that the application of Ishikawa (Cause and Effect or Tree diagram) led to converging results thus corroborating the validity of conclusions derived from risk assessment and FMEA. Therefore, the incorporation of FMEA analysis within the ISO22000 system of a pastry processing industry is considered imperative. PMID:21838557

  11. Instantaneous normal mode theory of diffusion and the potential energy landscape: Application to supercooled liquid CS2

    NASA Astrophysics Data System (ADS)

    Li, Wu-Xiong; Keyes, T.

    1999-09-01

    The pure translation (TR) imaginary-frequency (or unstable) instantaneous normal modes (INM), which we have proposed as representative of barrier crossing and diffusion, are obtained for seven densities and eight temperatures of supercooled and near-melting liquid CS2 via computer simulation. The self-diffusion constant D, with a range of over two decades, has been determined previously for these 56 states [Li and Keyes, J. Chem. Phys. 111, 328 (1999)], allowing a comprehensive test of the relation of INM to diffusion. INM theory is reviewed and extended. At each density Arrhenius T-dependence is found for the fraction fu of unstable modes, for the product <ω>ufu of the fraction times the averaged unstable frequency, and for D. The T-dependence of D is captured very accurately by fu at higher densities and by <ω>ufu at lower densities. Since the T-dependence of <ω>u is weak at high density, the formula D∝<ω>ufu provides a good representation at all densities; it is derived for the case of low-friction barrier crossing. Density-dependent activation energies determined by Arrhenius fits to <ω>ufu are in excellent agreement with those found from D. Thus, activation energies may be obtained with INM, requiring far less computational effort than an accurate simulation of D in supercooled liquids. Im-ω densities of states, <ρuTR(ω,T)>, are fit to the function a(T)ω exp[-(a2(T)ω/√T )a3(T)]. The strong T-dependence of D, absent in Lennard-Jones (LJ) liquids, arises from the multiplicative factor a(T); its activation energy is determined by the inflection-point energy on barriers to diffusion. Values of the exponent a3(T) somewhat greater than 2.0 suggest that liquid CS2 is nonfragile in the extended Angell-Kivelson scheme for the available states. A striking contrast is revealed between CS2 and LJ; a3→2 at low-T in CS2 and at high-T in LJ. The INM interpretation is that barrier height fluctuations in CS2 are negligible at low-T but grow with increasing T

  12. EXIST Perspective for SFXTs

    NASA Astrophysics Data System (ADS)

    Ubertini, Pietro; Sidoli, L.; Sguera, V.; Bazzano, A.

    2009-12-01

    Supergiant Fast X-ray Transients (SFXTs) are one of the most interesting (and unexpected) results of the INTEGRAL mission. They are a new class of HMXBs displaying short hard X-ray outbursts (duration less tha a day) characterized by fast flares (few hours timescale) and large dinamic range (10E3-10E4). The physical mechanism driving their peculiar behaviour is still unclear and highly debated: some models involve the structure of the supergiant companion donor wind (likely clumpy, in a spherical or non spherical geometry) and the orbital properties (wide separation with eccentric or circular orbit), while others involve the properties of the neutron star compact object and invoke very low magnetic field values (B < 1E10 G) or alternatively very high (B>1E14 G, magnetars). The picture is still highly unclear from the observational point of view as well: no cyclotron lines have been detected in the spectra, thus the strength of the neutron star magnetic field is unknown. Orbital periods have been measured in only 4 systems, spanning from 3.3 days to 165 days. Even the duty cycle seems to be quite different from source to source. The Energetic X-ray Imaging Survey Telescope (EXIST), with its hard X-ray all-sky survey and large improved limiting sensitivity, will allow us to get a clearer picture of SFXTs. A complete census of their number is essential to enlarge the sample. A long term and continuous as possible X-ray monitoring is crucial to -(1) obtain the duty cycle, -(2 )investigate their unknown orbital properties (separation, orbital period, eccentricity),- (3) to completely cover the whole outburst activity, (4)-to search for cyclotron lines in the high energy spectra. EXIST observations will provide crucial informations to test the different models and shed light on the peculiar behaviour of SFXTs.

  13. Renewable Energy Applications for Existing Buildings: Preprint

    SciTech Connect

    Hayter, S. J.; Kandt, A.

    2011-08-01

    This paper introduces technical opportunities, means, and methods for incorporating renewable energy (RE) technologies into building designs and operations. It provides an overview of RE resources and available technologies used successfully to offset building electrical and thermal energy loads. Methods for applying these technologies in buildings and the role of building energy efficiency in successful RE projects are addressed along with tips for implementing successful RE projects.

  14. Application of Multiple Imputation for Missing Values in Three-Way Three-Mode Multi-Environment Trial Data

    PubMed Central

    Tian, Ting; McLachlan, Geoffrey J.; Dieters, Mark J.; Basford, Kaye E.

    2015-01-01

    It is a common occurrence in plant breeding programs to observe missing values in three-way three-mode multi-environment trial (MET) data. We proposed modifications of models for estimating missing observations for these data arrays, and developed a novel approach in terms of hierarchical clustering. Multiple imputation (MI) was used in four ways, multiple agglomerative hierarchical clustering, normal distribution model, normal regression model, and predictive mean match. The later three models used both Bayesian analysis and non-Bayesian analysis, while the first approach used a clustering procedure with randomly selected attributes and assigned real values from the nearest neighbour to the one with missing observations. Different proportions of data entries in six complete datasets were randomly selected to be missing and the MI methods were compared based on the efficiency and accuracy of estimating those values. The results indicated that the models using Bayesian analysis had slightly higher accuracy of estimation performance than those using non-Bayesian analysis but they were more time-consuming. However, the novel approach of multiple agglomerative hierarchical clustering demonstrated the overall best performances. PMID:26689369

  15. Fuzzy cross-model cross-mode method and its application to update the finite element model of structures

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Xu, Dejian; Li, Yan; Duan, Zhongdong

    2011-07-01

    As a novel updating technique, cross-model cross-mode (CMCM) method possesses a high efficiency and capability of flexible selecting updating parameters. However, the success of this method depends on the accuracy of measured modal shapes. Usually, the measured modal shapes are inaccurate since many kinds of measured noises are inevitable. Furthermore, the complete testing modal shapes are required by CMCM method so that the calculating errors may be introduced into the measured modal shapes by conducting the modal expansion or model reduction technique. Therefore, this algorithm is faced with the challenge of updating the finite element (FE) model of practical complex structures. In this study, the fuzzy CMCM method is proposed in order to weaken the effect of errors of the measured modal shapes on the updated results. Then two simulated examples are applied to compare the performance of the fuzzy CMCM method with the CMCM method. The test results show that proposed method is more promising to update the FE model of practical structures than CMCM method.

  16. Dynamic Self-Referencing Approach to Whispering Gallery Mode Biosensing and Its Application to Measurement within Undiluted Serum.

    PubMed

    Reynolds, Tess; François, Alexandre; Riesen, Nicolas; Turvey, Michelle E; Nicholls, Stephen J; Hoffmann, Peter; Monro, Tanya M

    2016-04-01

    Biosensing within complex biological samples requires a sensor that can compensate for fluctuations in the signal due to changing environmental conditions and nonspecific binding events. To achieve this, we developed a novel self-referenced biosensor consisting of two almost identically sized dye-doped polystyrene microspheres placed on adjacent holes at the tip of a microstructured optical fiber (MOF). Here self-referenced biosensing is demonstrated with the detection of Neutravidin in undiluted, immunoglobulin-deprived human serum samples. The MOF allows remote excitation and collection of the whispering gallery modes (WGMs) of the microspheres while also providing a robust and easy to manipulate dip-sensing platform. By taking advantage of surface functionalization techniques, one microsphere acts as a dynamic reference, compensating for nonspecific binding events and changes in the environment (such as refractive index and temperature), while the other microsphere is functionalized to detect a specific interaction. The almost identical size allows the two spheres to have virtually identical refractive index sensitivity and surface area, while still having discernible WGM spectra. This ensures their responses to nonspecific binding and environmental changes are almost identical, whereby any specific changes, such as binding events, can be monitored via the relative movement between the two sets of WGM peaks. PMID:26954108

  17. Liquid Microjunction Surface Sampling Probe Fluid Dynamics: Characterization and Application of an Analyte Plug Formation Operational Mode

    NASA Astrophysics Data System (ADS)

    Elnaggar, Mariam S.; van Berkel, Gary J.

    2011-10-01

    The recently discovered sample plug formation and injection operational mode of a continuous flow, coaxial tube geometry, liquid microjunction surface sampling probe (LMJ-SSP) was further characterized and applied for concentration and mixing of analyte extracted from multiple areas on a surface and for nanoliter-scale chemical reactions of sampled material. A transparent LMJ-SSP was constructed and colored analytes were used so that the surface sampling process, plug formation, and the chemical reactions could be visually monitored at the sampling end of the probe before being analyzed by mass spectrometry of the injected sample plug. Injection plug peak widths were consistent for plug hold times as long as the 8 min maximum attempted (RSD below 1.5%). Furthermore, integrated injection peak signals were not significantly different for the range of hold times investigated. The ability to extract and completely mix individual samples within a fixed volume at the sampling end of the probe was demonstrated and a linear mass spectral response to the number of equivalent analyte spots sampled was observed. Using the color and mass changing chemical reduction of the redox dye 2,6-dichlorophenol-indophenol with ascorbic acid, the ability to sample, concentrate, and efficiently run reactions within the same plug volume within the probe was demonstrated.

  18. Liquid Microjunction Surface Sampling Probe Fluid Dynamics: Characterization and Application of an Analyte Plug Formation Operational Mode

    SciTech Connect

    ElNaggar, Mariam S; Van Berkel, Gary J

    2011-01-01

    The recently discovered sample plug formation and injection operational mode of a continuous flow, coaxial tube geometry, liquid microjunction surface sampling probe (LMJ-SSP) (J. Am. Soc. Mass Spectrom, 2011) was further characterized and applied for concentration and mixing of analyte extracted from multiple areas on a surface and for nanoliter-scale chemical reactions of sampled material. A transparent LMJ-SSP was constructed and colored analytes were used so that the surface sampling process, plug formation, and the chemical reactions could be visually monitored at the sampling end of the probe before being analyzed by mass spectrometry of the injected sample plug. Injection plug peak widths were consistent for plug hold times as long as the 8 minute maximum attempted (RSD below 1.5%). Furthermore, integrated injection peak signals were not significantly different for the range of hold times investigated. The ability to extract and completely mix individual samples within a fixed volume at the sampling end of the probe was demonstrated and a linear mass spectral response to the number of equivalent analyte spots sampled was observed. Using the color and mass changing chemical reduction of the redox dye 2,6-dichlorophenol-indophenol with ascorbic acid, the ability to sample, concentrate, and efficiently run reactions within the same plug volume within the probe was demonstrated.

  19. A reversed-phase/hydrophilic interaction mixed-mode C18-Diol stationary phase for multiple applications.

    PubMed

    Wang, Qing; Ye, Mao; Xu, Li; Shi, Zhi-guo

    2015-08-12

    A mixed-mode chromatographic packing material, C18 and diol groups modified silica (C18-Diol), was prepared with controllable hydrophobicity and hydrophilicity. It demonstrated excellent aqueous compatibility and stability in aqueous mobile phase; compared to the traditional C18 column, improved peak shape of basic analytes was also obtained. Additionally, it exhibited both reversed-phase liquid chromatographic (RPLC) and hydrophilic interaction chromatographic (HILIC) performance; the analyte separation scope was thus enlarged, demonstrated by simultaneous separation of twenty acids, bases and neutrals. More interestingly, a novel on-line two-dimensional liquid chromatography on the single column (2D-LC-1C) was established by modifying the high performance liquid chromatographic instrument only with the addition of an extra six-port two-position valve. The early co-eluted components of the extract of Lonicera japonica on the 1st-dimension (RPLC) were collected for the online re-injection to the 2nd-dimension (HILIC) by conveniently varying the mobile phase components. Six more peaks were obtained. The established system was simple, easy operation and low cost, which had advantages in analyzing complicated samples. PMID:26320974

  20. Supersymmetric mode converters

    NASA Astrophysics Data System (ADS)

    Heinrich, Matthias; Miri, Mohammad-Ali; Stützer, Simon; Nolte, Stefan; Szameit, Alexander; Christodoulides, Demetrios N.

    2015-08-01

    In recent years, the ever-increasing demand for high-capacity transmission systems has driven remarkable advances in technologies that encode information on an optical signal. Mode-division multiplexing makes use of individual modes supported by an optical waveguide as mutually orthogonal channels. The key requirement in this approach is the capability to selectively populate and extract specific modes. Optical supersymmetry (SUSY) has recently been proposed as a particularly elegant way to resolve this design challenge in a manner that is inherently scalable, and at the same time maintains compatibility with existing multiplexing strategies. Supersymmetric partners of multimode waveguides are characterized by the fact that they share all of their effective indices with the original waveguide. The crucial exception is the fundamental mode, which is absent from the spectrum of the partner waveguide. Here, we demonstrate experimentally how this global phase-matching property can be exploited for efficient mode conversion. Multimode structures and their superpartners are experimentally realized in coupled networks of femtosecond laser-written waveguides, and the corresponding light dynamics are directly observed by means of fluorescence microscopy. We show that SUSY transformations can readily facilitate the removal of the fundamental mode from multimode optical structures. In turn, hierarchical sequences of such SUSY partners naturally implement the conversion between modes of adjacent order. Our experiments illustrate just one of the many possibilities of how SUSY may serve as a building block for integrated mode-division multiplexing arrangements. Supersymmetric notions may enrich and expand integrated photonics by versatile optical components and desirable, yet previously unattainable, functionalities.

  1. Advances in single mode and high power AlGaInN laser diode technology for systems applications

    NASA Astrophysics Data System (ADS)

    Najda, Stephen P.; Perlin, Piotr; Suski, Tadek; Marona, Lujca; Boćkowski, Michal; Leszczyński, Mike; Wisniewski, Przemek; Czernecki, Robert; Kucharski, Robert; Targowski, Grzegorz; Smalc-Koziorowska, Julita; Stanczyk, Szymon; Watson, Scott; Kelly, Antony E.

    2015-03-01

    The AlGaInN material system allows for laser diodes to be fabricated over a very wide range of wavelengths from u.v., ~380nm, to the visible ~530nm, by tuning the indium content of the laser GaInN quantum well. Thus AlGaInN laser diode technology is a key enabler for the development of new disruptive system level applications in displays, telecom, defence and other industries.

  2. Does metapsychology still exist?

    PubMed

    Modell, A H

    1981-01-01

    Metapsychology has been under attack from two principal directions: from those who believe that metapsychology is no longer congruent with observations; and from those who see metapsychology as irrelevant, as they no longer share Freud's belief that psychoanalysis is a form of natural science. In addition there is no shared agreement as to the definition of metapsychology itself. The author observes three different functions of metapsychology: a selection of psychological phenomena that could be termed universal in the sense that they are characteristic of the human species; secondly a set of assumptions upon which a psychological system can be founded and made explicit; and thirdly metapsychology functions as a modelling device, an imaginary entity, an experiment in thinking. When we refer to metapsychology we are not describing a single entity but a broad heading that contains at least these three distinct functions. We believe that psychoanalysis is a unique discipline in that it shares with the hermeneutic disciplines the use of empathy as a mode of observation, viewing man from the inside, but subjects these observations to the organizing functions of metapsychology which views man from the outside. It is characteristic of psychoanalysis that there are rapid shifts from the I-Thou (empathic identification) to the I-It (naturalist observer) position. For this reason psychoanalysis cannot be fitted into any ready made epistemology. Any attempt to replace metapsychology by action theory or by the organizing principles of the structure of language are announcements of programmes yet to be realized and there is reason to doubt whether such programmes are realizable. There are, however, empiric discrepancies which require a modification but not the elimination of metapsychology. Our newer observations of narcissistic character disorders, especially the mirroring function, suggest that maturation is not necessarily equated with internalization - that a "fitting in

  3. Modeling of elastic nonlinearities in ferroelectric materials including nonlinear losses: application to nonlinear resonance mode of relaxors single crystals.

    PubMed

    Sebald, Gaël; Lebrun, Laurent; Guyomar, Daniel

    2005-04-01

    (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) and (1-x)Pb(Zn1/3Nb2/3)O3-xPbTiO3 (PZN-PT) single crystals are considered to behave like soft Pb(Zr,Ti)O3 (PZT) ceramics because of their small mechanical quality factor Qm and poor stability under external disturbances (Qm > 500-1000 for hard PZT ceramic, and Qm < 100 for soft PZT and PMN-PT and PZN-PT single crystals). At weak signal excitation of the first resonance mode, the displacement at the end of a lateral bar is proportional to the Q31d31 figure of merit that is very close to that found for hard PZT. Indeed the very large piezoelectric coefficient compensates the low Qm. But increasing alternating current (AC) field results in the appearance of strong non-linearities through a shift of the resonance frequency and jumps phenomenon observed on increasing and decreasing frequency sweep. It is shown in this paper that these nonlinearities are due to the nonlinear elastic compliance that can be modeled by a third order development of the constitutive piezoelectric equations. Experiments on PMN-PT and PZN-PT single crystals are used for comparison with the model to show the viability of the approach. Both the frequency shift and jumps phenomenon are simulated with a very good agreement with experimental results. The importance is also shown of losses associated with the third order term responsible for the large decrease of the mechanical quality factor for high strain levels. Thus, the nonlinear losses are related to the hysteresis of domain wall motion when subjected to large displacements. PMID:16060508

  4. Artemisinin-based antimalarial research: application of biotechnology to the production of artemisinin, its mode of action, and the mechanism of resistance of Plasmodium parasites.

    PubMed

    Muangphrom, Paskorn; Seki, Hikaru; Fukushima, Ery Odette; Muranaka, Toshiya

    2016-07-01

    Malaria is a worldwide disease caused by Plasmodium parasites. A sesquiterpene endoperoxide artemisinin isolated from Artemisia annua was discovered and has been accepted for its use in artemisinin-based combinatorial therapies, as the most effective current antimalarial treatment. However, the quantity of this compound produced from the A. annua plant is very low, and the availability of artemisinin is insufficient to treat all infected patients. In addition, the emergence of artemisinin-resistant Plasmodium has been reported recently. Several techniques have been applied to enhance artemisinin availability, and studies related to its mode of action and the mechanism of resistance of malaria-causing parasites are ongoing. In this review, we summarize the application of modern technologies to improve the production of artemisinin, including our ongoing research on artemisinin biosynthetic genes in other Artemisia species. The current understanding of the mode of action of artemisinin as well as the mechanism of resistance against this compound in Plasmodium parasites is also presented. Finally, the current situation of malaria infection and the future direction of antimalarial drug development are discussed. PMID:27250562

  5. STiC — a mixed mode silicon photomultiplier readout ASIC for time-of-flight applications

    NASA Astrophysics Data System (ADS)

    Harion, T.; Briggl, K.; Chen, H.; Fischer, P.; Gil, A.; Kiworra, V.; Ritzert, M.; Schultz-Coulon, H.-C.; Shen, W.; Stankova, V.

    2014-02-01

    STiC is an application specific integrated circuit (ASIC) for the readout of silicon photomultipliers. The chip has been designed to provide a very high timing resolution for time-of-flight applications in medical imaging and particle physics. It is dedicated in particular to the EndoToFPET-US project, which is developing an endoscopic PET detector combined with ultrasound imaging for early pancreas and prostate cancer detection. This PET system aims to provide a spatial resolution of 1 mm and a time-of-flight resolution of 200 ps FWHM. The analog frontend of STiC can use either a differential or single ended connection to the SiPM. The time and energy information of the detector signal is encoded into two time stamps. A special linearized time-over-threshold method is used to obtain a linear relation between the signal charge and the measured signal width, improving the energy resolution. The trigger signals are digitized by an integrated TDC module with a resolution of less than 20 ps. The TDC data is stored in an internal memory and transfered over a 160 MBit/s serial link using 8/10 bit encoding. First coincidence measurements using a 3.1 × 3.1 × 15 mm3 LYSO crystal and a S10362-33-50 Hamamtsu MPPC show a coincidence time resolution of less than 285 ps. We present details on the chip design as well as first characterization measurements.

  6. Single-mode fibre optic Bragg grating sensing on the base of birefringence in surface-mounting and embedding applications

    NASA Astrophysics Data System (ADS)

    Lee, Jung-Ryul; Tsuda, Hiroshi; Koo, Bon-Yong

    2007-02-01

    Birefringence effects in the two typical installation techniques of fibre Bragg grating(FBG) sensor are investigated: surface-mounting and embedding configurations. When the FBG is bonded on a host material, the sensitivity loss in ultrasonic measurement caused by glue-induced low-birefringence is first reported. Next, the transverse stress-induced high birefringence when the FBG is embedded into a fabric composite laminate is measured as 3.6×10 -4. Such induced-birefringence effects are experimentally analysed in mechanical applications. Simple and effective solutions with respect to the respective installation configurations for removing the birefringence effect are proposed and the obtained zero-birefringence cases are compared with the birefringent cases.

  7. Straightening: existence, uniqueness and stability

    PubMed Central

    Destrade, M.; Ogden, R. W.; Sgura, I.; Vergori, L.

    2014-01-01

    One of the least studied universal deformations of incompressible nonlinear elasticity, namely the straightening of a sector of a circular cylinder into a rectangular block, is revisited here and, in particular, issues of existence and stability are addressed. Particular attention is paid to the system of forces required to sustain the large static deformation, including by the application of end couples. The influence of geometric parameters and constitutive models on the appearance of wrinkles on the compressed face of the block is also studied. Different numerical methods for solving the incremental stability problem are compared and it is found that the impedance matrix method, based on the resolution of a matrix Riccati differential equation, is the more precise. PMID:24711723

  8. Air-Cooled Stack Freeze Tolerance Freeze Failure Modes and Freeze Tolerance Strategies for GenDriveTM Material Handling Application Systems and Stacks Final Scientific Report

    SciTech Connect

    Hancock, David, W.

    2012-02-14

    Air-cooled stack technology offers the potential for a simpler system architecture (versus liquid-cooled) for applications below 4 kilowatts. The combined cooling and cathode air allows for a reduction in part count and hence a lower cost solution. However, efficient heat rejection challenges escalate as power and ambient temperature increase. For applications in ambient temperatures below freezing, the air-cooled approach has additional challenges associated with not overcooling the fuel cell stack. The focus of this project was freeze tolerance while maintaining all other stack and system requirements. Through this project, Plug Power advanced the state of the art in technology for air-cooled PEM fuel cell stacks and related GenDrive material handling application fuel cell systems. This was accomplished through a collaborative work plan to improve freeze tolerance and mitigate freeze-thaw effect failure modes within innovative material handling equipment fuel cell systems designed for use in freezer forklift applications. Freeze tolerance remains an area where additional research and understanding can help fuel cells to become commercially viable. This project evaluated both stack level and system level solutions to improve fuel cell stack freeze tolerance. At this time, the most cost effective solutions are at the system level. The freeze mitigation strategies developed over the course of this project could be used to drive fuel cell commercialization. The fuel cell system studied in this project was Plug Power's commercially available GenDrive platform providing battery replacement for equipment in the material handling industry. The fuel cell stacks were Ballard's commercially available FCvelocity 9SSL (9SSL) liquid-cooled PEM fuel cell stack and FCvelocity 1020ACS (Mk1020) air-cooled PEM fuel cell stack.

  9. Stopbands in the existence domains of acoustic solitons

    SciTech Connect

    Nsengiyumva, F. Hellberg, M. A. Mace, R. L.; Verheest, F.

    2014-10-15

    A fully nonlinear Sagdeev pseudopotential approach is used to study the existence domain of fast mode ion-acoustic solitons in a three-species plasma composed of cold and warm adiabatic positive ion species and Boltzmann electrons. It is shown that for appropriate values of the cold-to-warm ion charge-to-mass ratio, μ, and the effective warm ion-to-electron temperature ratio, τ, there is a range in cold to warm ion charge density ratio, f, over which a stopband in soliton speed exists. Solitons do not propagate in the stopband, although they can occur for both higher and lower speeds. The stopbands are associated with a limiting curve of the existence domain that is double-valued in speed for a range of values of f. Analytical estimates of the upper and lower limits of τ and μ that support stopbands are found. It is suggested that, inter alia, the analysis should be applicable to the solar wind plasma.

  10. Stopbands in the existence domains of acoustic solitons

    NASA Astrophysics Data System (ADS)

    Nsengiyumva, F.; Hellberg, M. A.; Verheest, F.; Mace, R. L.

    2014-10-01

    A fully nonlinear Sagdeev pseudopotential approach is used to study the existence domain of fast mode ion-acoustic solitons in a three-species plasma composed of cold and warm adiabatic positive ion species and Boltzmann electrons. It is shown that for appropriate values of the cold-to-warm ion charge-to-mass ratio, μ, and the effective warm ion-to-electron temperature ratio, τ, there is a range in cold to warm ion charge density ratio, f, over which a stopband in soliton speed exists. Solitons do not propagate in the stopband, although they can occur for both higher and lower speeds. The stopbands are associated with a limiting curve of the existence domain that is double-valued in speed for a range of values of f. Analytical estimates of the upper and lower limits of τ and μ that support stopbands are found. It is suggested that, inter alia, the analysis should be applicable to the solar wind plasma.

  11. Effect of the Mode of Application of Cryopreserved Human Amniotic Membrane on Adhesion Formation after Abdomino-Pelvic Surgery in a Mouse Model

    PubMed Central

    Nassif, Joseph; Abbasi, Sehrish A.; Kechli, Mohamad Karim; Boutary, Suzan S.; Ghulmiyyah, Labib; Khalifeh, Ibrahim; Abou Ghaddara, Hussein; Nassar, Anwar H.

    2016-01-01

    Adhesions after abdomino-pelvic surgery are a cause of morbidity and reoperations. The use of human amniotic membrane (HAM) for adhesion prevention has given controversial results. The mode of administration of the amniotic membrane has not been well studied. This study assessed the efficacy of two modes of application of cryopreserved HAM, patch or fragmented in Lactated Ringer (LR) solution, for the prevention of pelvic adhesion formation postabdomino-pelvic surgery in a mice model. After a midline laparotomy incision, a small cautery lesion was done on each side of the abdominal wall peritoneum in mice. In Group A (control; n = 42), the abdomen was closed directly, Group B (n = 42) received 2.5 ml of LR prior to closure. In Groups C (n = 42) and D (n = 42), a 2 cm × 2 cm patch of HAM and another one fragmented and dispersed in 2.5 ml of LR were applied prior to closure, respectively. Two weeks later, a laparotomy was performed, and gross and pathological evaluation of adhesions, fibrosis, angiogenesis, and inflammation were conducted. Group D exhibited a significantly lower rate of gross adhesion formation. Fibrosis was significantly lowest in Group C as compared to the control. Group B had the lowest vascular formation in the adhesions. The use of HAM fragmented in LR solution is associated with a significantly lower incidence of postoperative adhesions in mice when compared to LR alone, HAM patch, or control. The mechanism of action of this reduction needs to be elucidated by future studies. PMID:27066485

  12. Secondary Instability of Second Modes in Hypersonic Boundary Layers

    NASA Technical Reports Server (NTRS)

    Li, Fei; Choudhari, Meelan M.; Chang, Chau-Lyan; White, Jeffery A.

    2012-01-01

    Second mode disturbances dominate the primary instability stage of transition in a number of hypersonic flow configurations. The highest amplification rates of second mode disturbances are usually associated with 2D (or axisymmetric) perturbations and, therefore, a likely scenario for the onset of the three-dimensionality required for laminar-turbulent transition corresponds to the parametric amplification of 3D secondary instabilities in the presence of 2D, finite amplitude second mode disturbances. The secondary instability of second mode disturbances is studied for selected canonical flow configurations. The basic state for the secondary instability analysis is obtained by tracking the linear and nonlinear evolution of 2D, second mode disturbances using nonlinear parabolized stability equations. Unlike in previous studies, the selection of primary disturbances used for the secondary instability analysis was based on their potential relevance to transition in a low disturbance environment and the effects of nonlinearity on the evolution of primary disturbances was accounted for. Strongly nonlinear effects related to the self-interaction of second mode disturbances lead to an upstream shift in the upper branch neutral location. Secondary instability computations confirm the previously known dominance of subharmonic modes at relatively small primary amplitudes. However, for the Purdue Mach 6 compression cone configuration, it was shown that a strong fundamental secondary instability can exist for a range of initial amplitudes of the most amplified second mode disturbance, indicating that the exclusive focus on subharmonic modes in the previous applications of secondary instability theory to second mode primary instability may not have been fully justified.

  13. Circadian response of annual weeds in a natural setting to high and low application rates of four herbicides with different modes of actions.

    PubMed

    Miller, Ryan P; Martinson, Krishona B; Sothern, Robert B; Durgan, Beverly R; Gunsolus, Jeffrey L

    2003-03-01

    Four herbicides [glyphosate (GLYT), an amino acid synthesis inhibitor; glufosinate (GLUF), a glutamine synthetase inhibitor; fomesafen (FOME), a protoporphyrinogen oxidase inhibitor, and chlorimuron ethyl (CLIM), an acetolactate synthase inhibitor] were used to examine the influence of time of day of application on the control of a variety of annual broadleaf weeds in field studies conducted in Minnesota (five studies on GLYT and GLUF, three studies on FOME and CLIM). All herbicides were applied with an adjuvant at recommended high and low (half or quarter strength) rates every 3h between 06:00 and 24:00h local time. Visual ratings of percent weed control evaluated at 14d were analyzed by herbicide and application rate for each study and across studies for time-of-day effect by analysis of variance (ANOVA) and single cosinor. A circadian response to each herbicide was found, with greatest weed control observed between 09:00 and 18:00h. Increasing the herbicide application rate did not overcome the time-of-day effect (ANOVA: p < or = 0.008 for time-of-day effect for each herbicide and application rate). The least-squares fit of a 24h cosine was significant (p < or = 0.001) for each herbicide and application rate, with double amplitudes of 18-82% (units = % visual control) and estimated peaks (acrophases) near midday between 12:40 and 13:35h. Analysis of residuals obtained from multiple regression that included weed height, herbicide rate, temperature, and relative humidity as independent factors also found a significant time-effect by both ANOVA and cosinor for each herbicide and rate, with acrophases advancing significantly by 3 to 7h for GLYT and GLUF, but not for FOME or CLIM. These results suggest that the four herbicides, while belonging to different families with different modes of action, may reveal different peak times of efficacy when adjusting for environmental factors. Nonetheless, each displays similar circadian patterns when influenced by these factors

  14. Control of neoclassical tearing modes

    NASA Astrophysics Data System (ADS)

    Maraschek, M.

    2012-07-01

    Neoclassically driven tearing modes (NTMs) are a major problem for tokamaks operating in a conventional ELMy H-mode scenario. Depending on the mode numbers these pressure-driven perturbations cause a mild reduction in the maximum achievable βN = βt/(Ip/aBt) before the onset of the NTM, or can even lead to disruptions at a low edge safety factor, q95. A control of these types of modes in high βN plasmas is therefore of vital interest for magnetically confined fusion plasmas. The control consists of two major approaches, namely the control of the excitation of these modes and the removal, or at least mitigation, of these modes, once an excitation could not be avoided. For both routes examples will be given and the applicability of these approaches to ITER will be discussed.

  15. CRADA Final Report: Application of Dual-Mode Invertor Control to Commercially Available Radial-Gap Permanent Magnet Motors - Vol. 1

    SciTech Connect

    Lawler, J.S.; McKeever, J.W.; Downing, M.E.; Stahlhut, R.D; Bremmer, R.; Shoemaker, J.M.; Seksarian, A.K.; Poore, B.; Lutz, J.

    2006-05-01

    John Deere and Company (Deere), their partner, UQM Technologies, Inc. (UQM), and the Oak Ridge National Laboratory's (ORNL's) Power Electronics and Electric Machinery Research Center (PEEMRC) recently completed work on the cooperative research and development agreement (CRADA) Number ORNL 04-0691 outlined in this report. CRADA 04-0691 addresses two topical issues of interest to Deere: (1) Improved characterization of hydrogen storage and heat-transfer management; and (2) Potential benefits from advanced electric motor traction-drive technologies. This report presents the findings of the collaborative examination of potential operational and cost benefits from using ORNL/PEEMRC dual-mode inverter control (DMIC) to drive permanent magnet (PM) motors in applications of interest to Deere. DMIC was initially developed and patented by ORNL to enable PM motors to be driven to speeds far above base speed where the back-electromotive force (emf) equals the source voltage where it is increasingly difficult to inject current into the motor. DMIC is a modification of conventional phase advance (CPA). DMIC's dual-speed modes are below base speed, where traditional pulse-width modulation (PWM) achieves maximum torque per ampere (amp), and above base speed, where six-step operation achieves maximum power per amp. The modification that enables DMIC adds two anti-parallel thyristors in each of the three motor phases, which consequently adds the cost of six thyristors. Two features evaluated in this collaboration with potential to justify the additional thyristor cost were a possible reduction in motor cost and savings during operation because of higher efficiency, both permitted because of lower current. The collaborative analysis showed that the reduction of motor cost and base cost of the inverter was small, while the cost of adding six thyristors was greater than anticipated. Modeling the DMIC control displayed inverter efficiency gains due to reduced current, especially under

  16. Inducing Photonic Transitions between Discrete Modes in a Silicon Optical Microcavity

    NASA Astrophysics Data System (ADS)

    Dong, Po; Preble, Stefan F.; Robinson, Jacob T.; Manipatruni, Sasikanth; Lipson, Michal

    2008-01-01

    We show the existence of direct photonic transitions between modes of a silicon optical microcavity spaced apart in wavelength by over 8 nm. This is achieved by using ultrafast tuning of the refractive index of the cavity over a time interval that is comparable to the inverse of the frequency separation of modes. The demonstrated frequency mixing effect, i.e., the transitions between the modes, would enable on-chip silicon comb sources which can find wide applications in optical sensing, precise spectroscopy, and wavelength-division multiplexing for optical communications and interconnects.

  17. 2-μm high-power multiple-frequency single-mode Q-switched Ho:YLF laser for DIAL application

    NASA Astrophysics Data System (ADS)

    Gibert, Fabien; Edouart, Dimitri; Cénac, Claire; Le Mounier, Florian

    2014-09-01

    We report on the development and the demonstration of a two-wavelength single-frequency laser oscillator based on Ho:YLF crystal. This laser is especially suitable for application as a transmitter in differential absorption lidar (DIAL)/integrated path differential absorption (IPDA) measurements of atmospheric carbon dioxide (CO2) using the R30 CO2 absorption line at 2,050.967 nm. The oscillator consists in a fiber-coupled and free-space solid-state hybrid system and can be used in high-energy middle-rate or moderate-energy high-rate configurations. The latter produced On and Off sequentially single-frequency laser pulses with 13 mJ of energy at a repetition rate of 2 kHz and pulse duration of 42 ns. The pulse energy and frequency stabilities are specially documented in free-running, single-frequency and two-frequency seeding single-mode operations. Standard deviation is 7.7 % for pulse energy and 2 MHz for frequency stability for the two-wavelength seeding operation. Allan variance plot shows that frequency fluctuations are reduced below 70 kHz for 10 s of averaging which is suitable for accurate CO2 DIAL or IPDA measurements.

  18. One-pot preparation of a mixed-mode organic-silica hybrid monolithic capillary column and its application in determination of endogenous gibberellins in plant tissues.

    PubMed

    Zhang, Zheng; Hao, Yan-Hong; Ding, Jun; Xu, Sheng-Nan; Yuan, Bi-Feng; Feng, Yu-Qi

    2015-10-16

    A newly improved one-pot method, based on "thiol-ene" click chemistry and sol-gel approach in microemulsion system, was developed for the preparation of C8/PO(OH)2-silica hybrid monolithic capillary column. The prepared monolith possesses large specific surface area, narrow mesopore size distribution and high column efficiency. The monolithic column was demonstrated to have cation exchange/reversed-phase (CX/RP) mixed-mode retention for analytes on nano-liquid chromatography (nano-LC). On the basis of the developed nano-LC system with MS detector coupled to pipette tip solid phase extraction (PT-SPE) and derivatization process, we then realized simultaneous determination of 10 gibberellins (GAs) with low limits of detection (LODs, 0.003-0.025 ng/mL). Furthermore, 6 endogenous GAs in only 5mg rice leaves (fresh weight) were successfully detected and quantified. The developed PT-SPE-nano-LC-MS strategy may offer promising applications in the determination of low abundant bioactive molecules from complex matrix. PMID:26365908

  19. Reduction of mode partition noise of FP-LD by using Mach-Zehnder interferometer for RSOA-based DWDM applications.

    PubMed

    Yoo, Sang-Hwa; Moon, Sang-Rok; Kye, Myeonggyun; Lee, Chang-Hee

    2016-06-27

    We investigate reduction of mode partition noise of a spectrally sliced Fabry-Perot laser diode (FP-LD) for application to seeded DWDM systems. The proposed scheme for the noise reduction incorporates a fiber-based Mach-Zehnder interferometer (MZI) and a reflective semiconductor optical amplifier (RSOA). The MZI enables to reduce a relative intensity noise (RIN) more than 3 dB with better noise distributions. Experimental results of 10-Gb/s signal transmission exhibit a considerable bit-error-rate (BER) reduction by three orders of magnitude at the given received power. After the noise reduction, the FP-LD is applied to a 10-Gb/s DWDM system as a seed-light-source. In a local-seeding scheme, return-to-zero (RZ) and carrier-suppressed (CS)-RZ signal formats are compared as a function of transmission distance. Furthermore, a back-reflection induced impairment is evaluated in a remote-seeding scheme. We also count the number of useable channels to show the feasibility of DWDM transmission. PMID:27410602

  20. Investigation of crystallinity and planar defects in the Si nanowires grown by vapor-liquid-solid mode using indium catalyst for solar cell applications

    NASA Astrophysics Data System (ADS)

    Ajmal Khan, Muhammad; Ishikawa, Yasuaki; Kita, Ippei; Tani, Ayumi; Yano, Hiroshi; Fuyuki, Takashi; Konagai, Makoto

    2016-01-01

    Stacking-fault-free and planar defect (twinning plane)-free In-catalyzed Si nanowires (NWs) are essential for carrier transport and nanoscale device applications. In this article, In-catalyzed, vertically aligned, and cone-shaped Si NWs on Si(111) were grown successfully, in the vapor-liquid-solid (VLS) mode. In particular, the influences of substrate temperature (TS) and cooling rate (ΔTS/Δt) on the formation of planar defects, twinning planes along the [112] direction, and stacking faults in Si NWs were investigated. When TS was decreased from 600 °C to room temperature at a rate of 100 °C/240 s after Si NW growth, twinning plane defects perpendicular to the substrate and along different segments of (111)-oriented Si NWs were observed. Finally, one simple model was proposed to explain the stacking fault formation as well as Si NW length limitation due to the In-nanoparticle (In-NP) migration, and root causes of the twinning plane defects in the Si-NWs.

  1. Single "click" synthesis of a mixed-mode silica sorbent and application in matrix solid-phase dispersion extraction of β-agonists from porcine liver.

    PubMed

    Zhu, Yuling; Yang, Siwen; Chen, Gang; Xing, Jun

    2014-08-01

    A single "click" strategy is proposed for the preparation of a reversed-phase/weak cation-exchange mixed-mode silica-based sorbent (silica-WCX). Upon this strategy, both 1-dodecyne and 5-hexynoic acid were simultaneously immobilized onto azide-silica in varied ratio via Cu (I)-catalyzed azide-alkyne cycloaddition click reaction. The chemical compositions of silica-WCXs were characterized by elemental analysis, acid-base titration and Fourier transform-infrared spectroscopy. The results indicated that the actual mole ratio of n-dodecyl to carboxylic group on the sorbent is almost the same as the reactant ratio of 1-dodecyne to 5-hexynoic acid, and the repeatability of synthesis method is good. After that, two β-agonists, clenbuterol and ractopamine, were selected as model drug residues to evaluate the applicability of silica-WCX in matrix solid-phase dispersion extraction for the determination of basic drug residues in porcine liver by HPLC/UV. In comparison with some commercial sorbents, silica-WCX exhibited higher recoveries and better purification capability. Under the optimized conditions, linearity ranges were between 0.04 and 8.0μg/g for both analytes with coefficients of determination (R(2)) higher than 0.9997. The average recoveries at three spiked levels ranged from 92.5% to 105.0% with RSDs less than 6.6%. PMID:24929910

  2. Application of the U.S. EPA mode of action Framework for purposes of guiding future research: a case study involving the oral carcinogenicity of hexavalent chromium.

    PubMed

    Thompson, Chad M; Haws, Laurie C; Harris, Mark A; Gatto, Nicole M; Proctor, Deborah M

    2011-01-01

    Mode of action (MOA) analysis provides a systematic description of key events leading to adverse health effects in animal bioassays for the purpose of informing human health risk assessment. Uncertainties and data gaps identified in the MOA analysis may also be used to guide future research to improve understanding of the MOAs underlying a specific toxic response and foster development of toxicokinetic and toxicodynamic models. An MOA analysis, consistent with approaches outlined in the MOA Framework as described in the Guidelines for Carcinogen Risk Assessment, was conducted to evaluate small intestinal tumors observed in mice chronically exposed to relatively high concentrations of hexavalent chromium (Cr(VI)) in drinking water. Based on review of the literature, key events in the MOA are hypothesized to include saturation of the reductive capacity of the upper gastrointestinal tract, absorption of Cr(VI) into the intestinal epithelium, oxidative stress and inflammation, cell proliferation, direct and/or indirect DNA modification, and mutagenesis. Although available data generally support the plausibility of these key events, several unresolved questions and data gaps were identified, highlighting the need for obtaining critical toxicokinetic and toxicodynamic data in the target tissue and in the low-dose range. Experimental assays that can address these data gaps are discussed along with strategies for comparisons between responsive and nonresponsive tissues and species. This analysis provides a practical application of MOA Framework guidance and is instructive for the design of studies to improve upon the information available for quantitative risk assessment. PMID:20947717

  3. Helicon modes in uniform plasmas. I. Low m modes

    NASA Astrophysics Data System (ADS)

    Urrutia, J. M.; Stenzel, R. L.

    2015-09-01

    Helicons are whistler modes with azimuthal wave numbers. They arise in bounded gaseous and solid state plasmas, but the present work shows that very similar modes also exist in unbounded uniform plasmas. The antenna properties determine the mode structure. A simple antenna is a magnetic loop with dipole moment aligned either along or across the ambient background magnetic field B0. For such configurations, the wave magnetic field has been measured in space and time in a large and uniform laboratory plasma. The observed wave topology for a dipole along B0 is similar to that of an m = 0 helicon mode. It consists of a sequence of alternating whistler vortices. For a dipole across B0, an m = 1 mode is excited which can be considered as a transverse vortex which rotates around B0. In m = 0 modes, the field lines are confined to each half-wavelength vortex while for m = 1 modes they pass through the entire wave train. A subset of m = 1 field lines forms two nested helices which rotate in space and time like corkscrews. Depending on the type of the antenna, both m = + 1 and m = -1 modes can be excited. Helicons in unbounded plasmas also propagate transverse to B0. The transverse and parallel wave numbers are about equal and form oblique phase fronts as in whistler Gendrin modes. By superimposing small amplitude fields of several loop antennas, various antenna combinations have been created. These include rotating field antennas, helical antennas, and directional antennas. The radiation efficiency is quantified by the radiation resistance. Since helicons exist in unbounded laboratory plasmas, they can also arise in space plasmas.

  4. Degradation mechanisms in high-power multi-mode InGaAs-AlGaAs strained quantum well lasers for high-reliability applications

    NASA Astrophysics Data System (ADS)

    Sin, Yongkun; Presser, Nathan; Brodie, Miles; Lingley, Zachary; Foran, Brendan; Moss, Steven C.

    2015-03-01

    Laser diode manufacturers perform accelerated multi-cell lifetests to estimate lifetimes of lasers using an empirical model. Since state-of-the-art laser diodes typically require a long period of latency before they degrade, significant amount of stress is applied to the lasers to generate failures in relatively short test durations. A drawback of this approach is the lack of mean-time-to-failure data under intermediate and low stress conditions, leading to uncertainty in model parameters (especially optical power and current exponent) and potential overestimation of lifetimes at usage conditions. This approach is a concern especially for satellite communication systems where high reliability is required of lasers for long-term duration in the space environment. A number of groups have studied reliability and degradation processes in GaAs-based lasers, but none of these studies have yielded a reliability model based on the physics of failure. The lack of such a model is also a concern for space applications where complete understanding of degradation mechanisms is necessary. Our present study addresses the aforementioned issues by performing long-term lifetests under low stress conditions followed by failure mode analysis (FMA) and physics of failure investigation. We performed low-stress lifetests on both MBE- and MOCVD-grown broad-area InGaAs- AlGaAs strained QW lasers under ACC (automatic current control) mode to study low-stress degradation mechanisms. Our lifetests have accumulated over 36,000 test hours and FMA is performed on failures using our angle polishing technique followed by EL. This technique allows us to identify failure types by observing dark line defects through a window introduced in backside metal contacts. We also investigated degradation mechanisms in MOCVD-grown broad-area InGaAs-AlGaAs strained QW lasers using various FMA techniques. Since it is a challenge to control defect densities during the growth of laser structures, we chose to

  5. Zero-frequency and slow elastic modes in phononic monolayer granular membranes.

    PubMed

    Zheng, Li-Yang; Pichard, Hélène; Tournat, Vincent; Theocharis, Georgios; Gusev, Vitalyi

    2016-07-01

    We theoretically study the dispersion properties of elastic waves in hexagonal and honeycomb monolayer granular membranes with either out-of-plane or in-plane particle motion. The particles interact predominantly via normal and transverse contact rigidities. When rotational degrees of freedom are taken into account, the bending and torsional rigidities of the intergrain contacts can control some of the phononic modes. The existence of zero-frequency modes, zero-group-velocity modes and their transformation into slow propagating phononic modes due to weak bending and torsional intergrain interactions are investigated. We also study the formation and manipulation of Dirac cones and multiple degenerated modes. This could motivate variety of potential applications in elastic waves control by manipulating the contact rigidities in granular phononic crystals. PMID:26607105

  6. Multiple omnidirectional defect modes and nonlinear magnetic-field effects in metamaterial photonic superlattices with a polaritonic defect

    NASA Astrophysics Data System (ADS)

    Robles-Uriza, A. X.; Reyes Gómez, F.; Mejía-Salazar, J. R.

    2016-09-01

    We report the existence of multiple omnidirectional defect modes in the zero-nbar gap of photonic stacks, made of alternate layers of conventional dielectric and double-negative metamaterial, with a polaritonic defect layer. In the case of nonlinear magnetic metamaterials, the optical bistability phenomenon leads to switching from negligible to perfect transmission around these defect modes. We hope these findings have potential applications in the design and development of multichannel optical filters, power limiters, optical-diodes and optical-transistors.

  7. Atmospheric Excitation of Planetary Normal Modes

    NASA Technical Reports Server (NTRS)

    Tanimoto, Toshiro

    2001-01-01

    The objectives of this study were to: (1) understand the phenomenon of continuous free oscillations of the Earth and (2) examine the idea of using this phenomenon for planetary seismology. We first describe the results on (1) and present our evaluations of the idea (2) in the final section. In 1997, after almost forty years since the initial attempt by Benioff et al, continuous free oscillations of the Earth were discovered. Spheroidal fundamental modes between 2 and 7 millihertz are excited continuously with acceleration amplitudes of about 0.3-0.5 nanogals. The signal is now commonly found in virtually all data recorded by STS-1 type broadband seismometers at quiet sites. Seasonal variation in amplitude and the existence of two coupled modes between the atmosphere and the solid Earth support that these oscillations are excited by the atmosphere. Stochastic excitation due to atmospheric turbulence is a favored mechanism, providing a good match between theory and data. The atmosphere has ample energy to support this theory because excitation of these modes require only 500-10000 W whereas the atmosphere contains about 117 W of kinetic energy. An application of this phenomenon includes planetary seismology, because other planets may be oscillating due to atmospheric excitation. The interior structure of planets could be learned by determining the eigenfrequencies in the continuous free oscillations. It is especially attractive to pursue this idea for tectonically quiet planets, since quakes may be too infrequent to be recorded by seismic instruments.

  8. Inter-comb synchronization by mode-to-mode locking

    NASA Astrophysics Data System (ADS)

    Chun, Byung Jae; Kim, Young-Jin; Kim, Seung-Woo

    2016-08-01

    Two combs of fiber femtosecond lasers are synchronized through the optical frequency reference created by injection-locking of a diode laser to a single comb mode. Maintaining a mHz-level narrow linewidth, the optical frequency reference permits two combs to be stabilized by mode-to-mode locking with a relative stability of 1.52  ×  10‑16 at 10 s with a frequency slip of 2.46 mHz. This inter-comb synchronization can be utilized for applications such as dual-comb spectroscopy or ultra-short pulse synthesis without extra narrow-linewidth lasers.

  9. Current-interchange tearing modes: Conversion of interchange-type modes to tearing modes

    SciTech Connect

    Zheng, L. J.; Furukawa, M.

    2010-05-15

    It is shown that, in addition to usual neoclassical tearing modes, another type of nonclassical tearing mode exists in tokamaks: viz., current-interchange tearing modes (CITMs). CITMs are directly driven by unstable pressure-driven electromagnetic or electrostatic modes of the interchange type (e.g., interchange/ballooning modes, drift waves, etc.) due to the current gradient in tokamaks. Interchange-type modes exchange not only thermal and magnetic energies between flux tubes but also current. In a plasma with a current (or resistivity) gradient, such an interchange can create a current sheet at a mode resonance surface and result in the excitation of CITMs. Note that the interchange mode (i.e., Rayleigh-Taylor instability) is fundamental to tokamak physics. This new theory has an effect on both resistive magnetohydrodynamic stability and transport theories. Instabilities of the interchange type could be directly converted into CITMs, alternative to forming turbulent eddies through nonlinear coupling as in conventional transport theories. In particular, our CITM theory fills in the component in the transport theory of Rechester and Rosenbluth [Phys. Rev. Lett. 40, 38 (1978)] for the origin of magnetic island structure in axisymmetric tokamaks.

  10. Fast and sensitive method to determine parabens by capillary electrophoresis using automatic reverse electrode polarity stacking mode: application to hair samples.

    PubMed

    Sako, Alysson V F; Dolzan, Maressa D; Micke, Gustavo Amadeu

    2015-09-01

    This paper describes a fast and sensitive method for the determination of methyl, ethyl, propyl, and butylparaben in hair samples by capillary electrophoresis using automatic reverse electrode polarity stacking mode. In the proposed method, solutions are injected using the flush command of the analysis software (940 mbar) and the polarity switching is carried out automatically immediately after the sample injection. The advantages compared with conventional stacking methods are the increased analytical frequency, repeatability, and inter-day precision. All analyses were performed in a fused silica capillary (50 cm, 41.5 cm in effective length, 50 μm i.d.), and the background electrolyte was composed of 20 mmol L(-1) sodium tetraborate in 10 % of methanol, pH 9.3. For the reverse polarity, -25 kV/35 s was applied followed by application of +30 kV for the electrophoretic run. Temperature was set at 20 °C, and all analytes were monitored at 297 nm. The method showed acceptable linearity (r (2) > 0.997) in the studied range of 0.1-5.0 mg L(-1), limits of detection below 0.017 mg L(-1), and inter-day, intra-day, and instrumental precision better than 6.2, 3.6, and 4.6 %, respectively. Considering parabens is widely used as a preservative in many products and the reported possibility of damage to the hair and also to human health caused by these compounds, the proposed method was applied to evaluate the adsorption of parabens in hair samples. The results indicate that there is a greater adsorption of methylparaben compared to the other parabens tested and also dyed hairs had a greater adsorption capacity for parabens than natural hairs. PMID:26168974

  11. Energetic Particle-induced Geodesic Acoustic Mode

    SciTech Connect

    Fu, G.Y.

    2008-09-12

    A new energetic particle-induced Geodesic Acoustic Mode (EGAM) is shown to exist. The mode frequency, mode structure, and mode destabilization are determined non-perturbatively by energetic particle kinetic effects. In particular the EGAM frequency is found to be substantially lower than the standard GAM frequency. The radial mode width is determined by the energetic particle drift orbit width and can be fairly large for high energetic particle pressure and large safety factor. These results are consistent with the recent experimental observation of the beam- driven n=0 mode in DIII-D. The new mode is important since it can degrade energetic particle confinement as shown in the DIII-D experiments. The new mode may also affect the thermal plasma confinement via its interaction with plasma micro-turbulence.

  12. Identifying predictors of survey mode preference.

    PubMed

    Smyth, Jolene D; Olson, Kristen; Millar, Morgan M

    2014-11-01

    To increase the likelihood of response, many survey organizations attempt to provide sample members with a mode they are thought to prefer. Mode assignment is typically based on conventional wisdom or results from mode choice studies that presented only limited options. In this paper we draw heavily on research and theory from the mode effects and the survey participation literatures to develop a framework for understanding what characteristics should predict mode preferences. We then test these characteristics using data from two different surveys. We find that measures of familiarity with and access to a mode are the strongest predictors of mode preference and measures of safety concerns, physical abilities, and normative concerns are unexpectedly weak predictors. Our findings suggest that variables that may exist on sample frames can be used to inform the assignment of "preferred" modes to sample members. PMID:25131280

  13. Mode 2 fatigue crack growth specimen development

    NASA Technical Reports Server (NTRS)

    Buzzard, R. J.; Gross, B.; Srawley, J. E.

    1983-01-01

    A Mode II test specimen was developed which has potential application in understanding phemonena associated with mixed mode fatigue failures in high performance aircraft engine bearing races. The attributes of the specimen are: it contains one single ended notch, which simplifiers data gathering and reduction; the fatigue crack grous in-line with the direction of load application; a single axis test machine is sufficient to perform testing; and the Mode I component is vanishingly small.

  14. Adaptive mode control of a few-mode fiber by real-time mode decomposition.

    PubMed

    Huang, Liangjin; Leng, Jinyong; Zhou, Pu; Guo, Shaofeng; Lü, Haibin; Cheng, Xiang'ai

    2015-10-19

    A novel approach to adaptively control the beam profile in a few-mode fiber is experimentally demonstrated. We stress the fiber through an electric-controlled polarization controller, whose driven voltage depends on the current and target modal content difference obtained with the real-time mode decomposition. We have achieved selective excitations of LP01 and LP11 modes, as well as significant improvement of the beam quality factor, which may play crucial roles for high-power fiber lasers, fiber based telecommunication systems and other fundamental researches and applications. PMID:26480466

  15. Investigation of mode-locked, tunable from 1350 to 1550 nm, Cr4+:Y3Al5O12 laser for medical applications

    NASA Astrophysics Data System (ADS)

    Broslavets, Y. Y.; Fomitchev, A. A.

    1996-11-01

    We report on investigation of mode-locked regime in tunable Cr4+:YAG laser. Our experiments have been performed using Nd:YAG laser for pumping Cr4+:Y3Al5O12 laser. We have obtained mode-locked generation of tunable radiation in the range from 1,350 to 1,550 nm. There was a generation with pulse duration in ps range and repetition rate of 320 MHz. Using a 0.5 percent transmitting output mirror, as high as 305 mW of useful output power at 1.5 micrometers was obtained from the laser with 5.5 W of absorbed pump power. The laser has threshold for mode-locked regime near 7 W for synchronous mode locking and 5 W for active mode locking. We have analyzed the laser system with Kerr lens feedback in the phase trajectory of five-dimensional space. The computer simulation have shown the presence of asymptotically stable stationary point in behavior of temporal Gaussian beam similar spatial mode structure in the resonators, when the temporal mode does not change passing through all dispersion element in laser. Our calculations show that the sign of dispersion is very important for formation of phase portrait in our laser system. In conclusion, we have demonstrated Cr4+:YAG laser operation in mode-locked regime on the edge of stability region. The analysis of the solutions in our model reveals that chaotic instabilities can be reached through increasing of non-linear interaction temporal and spatial Gaussian beam. The characteristics of this laser systems can provide the source of laser radiation for diagnostics and therapy.

  16. Dissipative double-well potential: Nonlinear stationary and pulsating modes

    SciTech Connect

    Zezyulin, Dmitry A.; Konotop, Vladimir V.; Alfimov, Georgy L.

    2010-11-15

    The analysis of nonlinear modes in a complex absorbing double-well potential supported by linear gain is presented. Families of the nonlinear modes and their bifurcations are found numerically by means of the properly modified 'shooting' method. Linear stability and dynamics of the modes are studied. It is shown that no stable modes exist in the case of attractive nonlinearity, while stable modes, including nonsymmetric ones, are found when the nonlinearity is repulsive. Varying a control parameter (e.g., the height of barrier between the wells) results in switching from one mode to another. Apart from stationary modes we have found pulsating solutions emergent from unstable modes.

  17. Toroidal mode number transition of the edge localized modes in the KSTAR plasmas

    NASA Astrophysics Data System (ADS)

    Lee, J. E.; Yun, G. S.; Kim, M.; Lee, J.; Lee, W.; Park, H. K.; Domier, C. W.; Luhmann, N. C., Jr.; Ko, W. H.; the KSTAR Team

    2015-09-01

    Rapid transitions of the toroidal mode number (n ) have been often detected during the evolution of the edge localized modes (ELMs) in the inter-ELM-crash periods of the KSTAR tokamak plasmas. The mode number transitions accompany changes of the mode frequency ({{f}\\text{mode}} ) (e.g. n changed from 8 to 5 while {{f}\\text{mode}} changed from ~32 to 9 kHz). The observed transition phenomena have been diverse including small and large increase (or decrease) in the mode number and multiple transitions during a single inter-ELM-crash period. Two classes of the mode transitions were identified: non-overlapping transition and overlapping transition. The former case is characterized by the absence of coherent filamentary structure during the transition and the latter case is characterized by co-existence of two coherent filamentary structures with different mode numbers. Each transition process typically lasts a few hundreds to thousands of μs.

  18. Localized acoustic surface modes

    NASA Astrophysics Data System (ADS)

    Farhat, Mohamed; Chen, Pai-Yen; Bağcı, Hakan

    2016-04-01

    We introduce the concept of localized acoustic surface modes. We demonstrate that they are induced on a two-dimensional cylindrical rigid surface with subwavelength corrugations under excitation by an incident acoustic plane wave. Our results show that the corrugated rigid surface is acoustically equivalent to a cylindrical scatterer with uniform mass density that can be represented using a Drude-like model. This, indeed, suggests that plasmonic-like acoustic materials can be engineered with potential applications in various areas including sensing, imaging, and cloaking.

  19. Majorana edge modes with gain and loss

    NASA Astrophysics Data System (ADS)

    Yuce, C.

    2016-06-01

    We consider a non-Hermitian generalization of the Kitaev model and study the existence of stable Majorana zero energy modes. We show that they exist in the limit of zero chemical potential even if balanced gain and loss are randomly distributed along the lattice. We show that Majorana zero modes also appear if the chemical potential is different from zero provided that not the full Hamiltonian but the non-Hermitian part of the Hamiltonian is PT symmetric.

  20. Effect of Coupling between Fundamental and Cladding Modes on Bending Losses in Single-Polarization Single-Mode Photonic Crystal Fiber

    NASA Astrophysics Data System (ADS)

    Balvedi, Gláucia C.; Franco, Marcos A. R.

    2008-10-01

    In this paper we study the effect of bending on the performance of a single-polarization single-mode (SPSM) photonic crystal fiber previously reported in the literature. The optical fiber consists of a photonic crystal fiber with hexagonal lattice of circular air-holes with an elliptical core formed by eight enlarged holes surrounding the central region of the fiber. Numerical analysis based on full-vector finite element method (VFEM) with a cylindrical perfectly matched layer (PML) was applied to evaluate the bending loss and the confinement loss of the fiber. For the straight fiber only the fundamental slow axis mode (x-polarization) exist because of the very high confinement loss of the fundamental fast axis mode (y-polarization). However, for the bent fiber the fast axis mode and the slow axis mode couple with the gallery of the cladding modes. These coupling prevent the fast axis mode to reach the cutoff. As a consequence, the bending loss curve as a function of the wavelength presents oscillations related with these coupled modes. Our simulations demonstrate that the analyzed fiber does not maintain its single-polarization single-mode characteristics when it is bent with a small curvature radius of 10 mm. However, for a small wavelength range (1.50 μm to 1.53 μm) the fundamental slow axis mode presents values of bending loss lower then 0.1 dB/km while the fast axis mode reach losses of about 150 dB/km, what can be useful for some application.

  1. 30 CFR 780.12 - Operation plan: Existing structures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Operation plan: Existing structures. 780.12... PLAN § 780.12 Operation plan: Existing structures. (a) Each application shall contain a description of each existing structure proposed to be used in connection with or to facilitate the surface coal...

  2. 30 CFR 784.12 - Operation plan: Existing structures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Operation plan: Existing structures. 784.12... PLAN § 784.12 Operation plan: Existing structures. (a) Each application shall contain a description of each existing structure proposed to be used in connection with or to facilitate the surface coal...

  3. Exploring anti-reflection modes in disordered media.

    PubMed

    Kim, Moonseok; Choi, Wonjun; Yoon, Changhyeong; Kim, Guang Hoon; Kim, Seung-hyun; Yi, Gi-Ra; Park, Q-Han; Choi, Wonshik

    2015-05-18

    Sensing and manipulating targets hidden under scattering media are universal problems that take place in applications ranging from deep-tissue optical imaging to laser surgery. A major issue in these applications is the shallow light penetration caused by multiple scattering that reflects most of incident light. Although advances have been made to eliminate image distortion by a scattering medium, dealing with the light reflection has remained unchallenged. Here we present a method to minimize reflected intensity by finding and coupling light into the anti-reflection modes of a scattering medium. In doing so, we achieved more than a factor of 3 increase in light penetration. Our method of controlling reflected waves makes it readily applicable to in vivo applications in which detector sensors can only be positioned at the same side of illumination and will therefore lay the foundation of advancing the working depth of many existing optical imaging and treatment technologies. PMID:26074528

  4. Anisotropy and Strong-Coupling Effects on the Collective Mode Spectrum of Chiral Superconductors: Application to Sr2RuO4

    NASA Astrophysics Data System (ADS)

    Sauls, James; Wu, Hao; Chung, Suk Bum

    2015-06-01

    Recent theories of Sr2RuO4 based on the interplay of strong interactions, spin-orbit coupling and multi-band anisotropy predict chiral or helical ground states with strong anisotropy of the pairing states, with deep minima in the excitation gap, as well as strong phase anisotropy for the chiral ground state. We develop time-dependent mean field theory to calculate the Bosonic spectrum for the class of 2D chiral superconductors spanning 3He-A to chiral superconductors with strong anisotropy. Chiral superconductors support a pair of massive Bosonic excitations of the time-reversed pairs labeled by their parity under charge conjugation. These modes are degenerate for 2D 3He-A. Crystal field anisotropy lifts the degeneracy. Strong anisotropy also leads to low-lying Fermions, and thus to channels for the decay of the Bosonic modes. Selection rules and phase space considerations lead to large asymmetries in the lifetimes and hybridization of the Bosonic modes with the continuum of un-bound Fermion pairs. We also highlight results for the excitation of the Bosonic modes by microwave radiation that provide clear signatures of the Bosonic modes of an anisotropic chiral ground state.

  5. Experimental investigation on flow modes of electrospinning

    NASA Astrophysics Data System (ADS)

    Si, Ting; Li, Guang-Bin; Chen, Xing-Xing; Tian, Rui-Jun; Yin, Xie-Zhen

    2012-06-01

    Electrospinning experiments are performed by using a set of experimental apparatus, a stroboscopic system is adopted for capturing instantaneous images of the conejet configuration. The cone and the jet of aqueous solutions of polyethylene oxide (PEO) are formed from an orifice of a capillary tube under the electric field. The viscoelastic constitutive relationship of the PEO solution is measured and discussed. The phenomena owing to the jet instability are described, five flow modes and corresponding structures are obtained with variations of the fluid flow rate Q, the electric potential U and the distance h from the orifice of the capillary tube to the collector. The flow modes of the cone-jet configuration involves the steady bending mode, the rotating bending mode, the swinging rotating mode, the blurring bending mode and the branching mode. Regimes in the Q-U plane of the flow modes are also obtained. These results may provide the fundamentals to predict the operating conditions expected in practical applications.

  6. Global Alfven modes: Theory and experiment

    SciTech Connect

    Turnbull, A.D.; Strait, E.J.; Heidbrink, W.W.; Chu, M.S.; Duong, H.H.; Greene, J.M.; Lao, L.L.; Taylor, T.S.; Thompson, S.J. )

    1993-07-01

    It is shown that the theoretical predictions and experimental observations of toroidicity-induced Alfven eigenmodes (TAE's) are now in good agreement, with particularly detailed agreement in the mode frequencies. Calculations of the driving and damping rates predict the importance of continuum damping for low toroidal mode numbers and this is confirmed experimentally. However, theoretical calculations in finite-[beta], shaped discharges predict the existence of other global Alfven modes, in particular the ellipticity-induced Alfven eigenmode (EAE) and a new mode, the beta-induced Alfven eigenmode (BAE). The BAE mode is calculated to be in or below the same frequency range as the TAE mode and may contribute to the experimental observations at high [beta]. Experimental evidence and complementary analyses are presented confirming the presence of the EAE mode at higher frequencies.

  7. CRADA Final Report: Application of Dual-Mode Inverter Control to Commercially Available Radial-Gap Mermanent Magnet Motors - Vol. I

    SciTech Connect

    McKeever, John W; Lawler, Jack; Downing, Mark; Stahlhut, Ronnie D; Bremmer, R.; Shoemaker, J. M.; Seksarian, A. K.; Poore, B.; Lutz, Jon F

    2006-05-01

    John Deere and Company (Deere), their partner, UQM Technologies, Inc. (UQM), and the Oak Ridge National Laboratory's (ORNL's) Power Electronics and Electric Machinery Research Center (PEEMRC) recently completed work on the cooperative research and development agreement (CRADA) Number ORNL 04-0691 outlined in this report. CRADA 04-0691 addresses two topical issues of interest to Deere: (1) Improved characterization of hydrogen storage and heat-transfer management; and (2) Potential benefits from advanced electric motor traction-drive technologies. This report presents the findings of the collaborative examination of potential operational and cost benefits from using ORNL/PEEMRC dual-mode inverter control (DMIC) to drive permanent magnet (PM) motors in applications of interest to Deere. DMIC was initially developed and patented by ORNL to enable PM motors to be driven to speeds far above base speed where the back-electromotive force (emf) equals the source voltage where it is increasingly difficult to inject current into the motor. DMIC is a modification of conventional phase advance (CPA). DMIC's dual-speed modes are below base speed, where traditional pulse-width modulation (PWM) achieves maximum torque per ampere (amp), and above base speed, where six-step operation achieves maximum power per amp. The modification that enables DMIC adds two anti-parallel thyristors in each of the three motor phases, which consequently adds the cost of six thyristors. Two features evaluated in this collaboration with potential to justify the additional thyristor cost were a possible reduction in motor cost and savings during operation because of higher efficiency, both permitted because of lower current. The collaborative analysis showed that the reduction of motor cost and base cost of the inverter was small, while the cost of adding six thyristors was greater than anticipated. Modeling the DMIC control displayed inverter efficiency gains due to reduced current, especially under

  8. Maximum thrust mode evaluation

    NASA Technical Reports Server (NTRS)

    Orme, John S.; Nobbs, Steven G.

    1995-01-01

    Measured reductions in acceleration times which resulted from the application of the F-15 performance seeking control (PSC) maximum thrust mode during the dual-engine test phase is presented as a function of power setting and flight condition. Data were collected at altitudes of 30,000 and 45,000 feet at military and maximum afterburning power settings. The time savings for the supersonic acceleration is less than at subsonic Mach numbers because of the increased modeling and control complexity. In addition, the propulsion system was designed to be optimized at the mid supersonic Mach number range. Recall that even though the engine is at maximum afterburner, PSC does not trim the afterburner for the maximum thrust mode. Subsonically at military power, time to accelerate from Mach 0.6 to 0.95 was cut by between 6 and 8 percent with a single engine application of PSC, and over 14 percent when both engines were optimized. At maximum afterburner, the level of thrust increases were similar in magnitude to the military power results, but because of higher thrust levels at maximum afterburner and higher aircraft drag at supersonic Mach numbers the percentage thrust increase and time to accelerate was less than for the supersonic accelerations. Savings in time to accelerate supersonically at maximum afterburner ranged from 4 to 7 percent. In general, the maximum thrust mode has performed well, demonstrating significant thrust increases at military and maximum afterburner power. Increases of up to 15 percent at typical combat-type flight conditions were identified. Thrust increases of this magnitude could be useful in a combat situation.

  9. Hydrodynamic impact of a system with a single elastic mode I : theory and generalized solution with an application to an elastic airframe

    NASA Technical Reports Server (NTRS)

    Mayo, Wilbur L

    1952-01-01

    Solutions of impact of a rigid prismatic float connected by a massless spring to a rigid upper mass are presented. The solutions are based on hydrodynamic theory which has been experimentally confirmed for a rigid structure. Equations are given for defining the spring constant and the ratio of the sprung mass to the lower mass so that the two-mass system provides representation of the fundamental mode of an airplane wing. The forces calculated are more accurate than the forces which would be predicted for a rigid airframe since the effect of the fundamental mode on the hydrodynamic force is taken into account. In a comparison of the theoretical data with data for a severe flight-test landing impact, the effect of the fundamental mode on the hydrodynamic force is considered and response data are compared with experimental data.

  10. Application of mixed-mode, solid-phase extraction in environmental and clinical chemistry. Combining hydrogen-bonding, cation-exchange and Van der Waals interactions

    USGS Publications Warehouse

    Mills, M.S.; Thurman, E.M.; Pedersen, M.J.

    1993-01-01

    Silica- and styrene-divinylbenzene-based mixed-mode resins that contain C8, C18 and sulphonated cation-exchange groups were compared for their efficiency in isolation of neutral triazine compounds from water and of the basic drug, benzoylecgonine, from urine. The triazine compounds were isolated by a combination of Van der Waals and hydrogen-bonding interactions, and benzoylecgonine was isolated by Van der Waals interactions and cation exchange. All analytes were eluted with a polar organic solvent contaning 2% ammonium hydroxide. Larger recoveries (95%) were achieved on copolymerized mixed-mode resins where C18 and sulfonic acid are in closer proximity than on 'blended' mixed-mode resins (60-70% recovery).

  11. Broadband mode conversion via gradient index metamaterials

    PubMed Central

    Wang, HaiXiao; Xu, YaDong; Genevet, Patrice; Jiang, Jian-Hua; Chen, HuanYang

    2016-01-01

    We propose a design for broadband waveguide mode conversion based on gradient index metamaterials (GIMs). Numerical simulations demonstrate that the zeroth order of transverse magnetic mode or the first order of transverse electric mode (TM0/TE1) can be converted into the first order of transverse magnetic mode or the second order of transverse electric mode (TM1/TE2) for a broadband of frequencies. As an application, an asymmetric propagation is achieved by integrating zero index metamaterials inside the GIM waveguide. PMID:27098456

  12. Broadband mode conversion via gradient index metamaterials.

    PubMed

    Wang, HaiXiao; Xu, YaDong; Genevet, Patrice; Jiang, Jian-Hua; Chen, HuanYang

    2016-01-01

    We propose a design for broadband waveguide mode conversion based on gradient index metamaterials (GIMs). Numerical simulations demonstrate that the zeroth order of transverse magnetic mode or the first order of transverse electric mode (TM0/TE1) can be converted into the first order of transverse magnetic mode or the second order of transverse electric mode (TM1/TE2) for a broadband of frequencies. As an application, an asymmetric propagation is achieved by integrating zero index metamaterials inside the GIM waveguide. PMID:27098456

  13. Multi-layered mode structure of locked-tearing-modes after unlocking

    NASA Astrophysics Data System (ADS)

    Okabayashi, Michio; Logan, N.; Tobias, B.; Wang, Z.; Budny, B.; Nazikian, R.; Strait, E.; La Haye, R.; Paz-Soldan, C. J.; Ferraro, N.; Shiraki, D.; Hanson, J.; Zanca, P.; Paccagnella, R.

    2015-11-01

    Prevention of m/n=2/1 tearing modes (TM) by electro-magnetic torque injection has been successful in DIII-D and RFX-mod where plasma conditions and plasma shape are completely different. Understanding the internal structure in the post-unlocked phase is a pre-requisite to its application to reactor relevant plasmas such as in ITER. Ti and toroidal rotation perturbations show there exist several radially different TM layers. However, the phase shift between the applied field and the plasma response is rather small from plasma edge to the q ~3 domain, indicating that a kink-like response prevails. The biggest threat for sustaining an unlocked 2/1 mode is sudden distortion of the rotational profile due to the internal mode reconnection. Possible TM layer structure will be discussed with numerical MHD codes and TRANSP. This work is supported in part by the US Department of Energy under DE-AC02-09CH11466, DE-FG02-99ER54531, DE-SC0003913, and DE-FC02-04ER54698.

  14. Single-Mode VISAR

    SciTech Connect

    Krauter, K

    2007-11-16

    High energy-density physics (HEDP) experiments examine the properties of materials under extreme conditions. These experiments rely on the measurement of one or two velocities. These velocities are used to obtain Hugoniot relationships and thermodynamic equations of state. This methodology is referred to as 'velocimetry' and an instrument used to measure the shock wave is called a 'velocimeter' or a '(velocity) diagnostic'. The two most-widely used existing velocity diagnostics are; photonic Doppler velocimetry (PDV) and velocity interferometer system for any reflector (VISAR). PDV's advantages are a fast rise-time and ease of implementation but PDV has an upper velocity limit. Traditional implementations of VISAR have a rise time 10 times slower than PDV and are not easily implemented but are capable of measuring any velocity produced during HEDP experiments. This thesis describes a novel method of combining the positive attributes of PDV and VISAR into a more cost effective diagnostic called a Single-Mode VISAR (SMV). The new diagnostic will consist of PDV parts in a VISAR configuration. This configuration will enable the measurement of any velocity produced during shock physics experiments while the components used to build the diagnostic will give the diagnostic a fast rise time and make it easy to use. This thesis describes the process of building and testing the first single-mode VISAR. The tests include verifying the performance of the components and the diagnostic as a whole.

  15. High-mode spoof SPP of periodic metal grooves for ultra-sensitive terahertz sensing.

    PubMed

    Yao, Haizi; Zhong, Shuncong

    2014-10-20

    We report terahertz surface plasmon resonance (SPR) sensing based on prism-coupling to the spoof surface plasmon polariton (SSPP) mode existing on periodically grooved metal films. It was demonstrated that, except for the fundamental mode of the SSPP, there was also a higher mode SSPP wave when the depth of groove was larger. Both fundamental and high-order modes of SSPP could be used for terahertz sensing. We compared the performance of different modes of SSPP on the sensing sensitivity using both reflection amplitude and phase-jump information. The results indicated that the gap distance between the prism base and the metal film had a significant influence on the reflectivity of SPR sensing by affecting the coupling efficiency of an evanescent wave to an SSPP wave; also, high-order mode SSPP-based sensing had a high sensitivity of up to 2.27 THz/RIU, which nearly doubled the sensitivity of the fundamental mode. The application of high-mode SSPP has enormous potential for ultra-sensitive SPR sensing in the terahertz regime. PMID:25401547

  16. Transient analysis mode participation for modal survey target mode selection using MSC/NASTRAN DMAP

    NASA Technical Reports Server (NTRS)

    Barnett, Alan R.; Ibrahim, Omar M.; Sullivan, Timothy L.; Goodnight, Thomas W.

    1994-01-01

    Many methods have been developed to aid analysts in identifying component modes which contribute significantly to component responses. These modes, typically targeted for dynamic model correlation via a modal survey, are known as target modes. Most methods used to identify target modes are based on component global dynamic behavior. It is sometimes unclear if these methods identify all modes contributing to responses important to the analyst. These responses are usually those in areas of hardware design concerns. One method used to check the completeness of target mode sets and identify modes contributing significantly to important component responses is mode participation. With this method, the participation of component modes in dynamic responses is quantified. Those modes which have high participation are likely modal survey target modes. Mode participation is most beneficial when it is used with responses from analyses simulating actual flight events. For spacecraft, these responses are generated via a structural dynamic coupled loads analysis. Using MSC/NASTRAN DMAP, a method has been developed for calculating mode participation based on transient coupled loads analysis results. The algorithm has been implemented to be compatible with an existing coupled loads methodology and has been used successfully to develop a set of modal survey target modes.

  17. Does sporadic Leber's disease exist?

    PubMed

    Nikoskelainen, E; Nummelin, K; Savontaus, M L

    1988-12-01

    This study gives some illustrative case reports of the difficulties in the diagnosis of Leber's hereditary optic neuroretinopathy. It underlies the importance of careful family history and search for peripapillary microangiopathy in the maternal relatives of patients suspected to suffer from Leber's disease. The article casts doubt on the existence of so-called sporadic Leber's disease. PMID:2977137

  18. Trapped-mode resonances in asymmetric terahertz subwavelength structures

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Zhou, Qingli; Shi, Yulei; Li, Chenyu; Zhang, Cunlin

    2016-07-01

    We demonstrate that the trapped-mode resonance with Fano-shaped spectrum can be induced in terahertz metamaterial with asymmetric double-bar structure. Spacing between two bars permits the tuning of resonant position and lineshape in a controlled manner, showing an anomalous increased coupling strength with spacing. The steep phase change around transparency region indicates slow-light effect proved by the retrieved group delays. Simulated results verify the coupling that exists between the bars of the same unit cell and those of the neighbouring cells. Our simplified structure offers the potential application in terahertz modulators and slow-light devices.

  19. Specific Energy as an Index to Identify the Critical Failure Mode Transition Depth in Rock Cutting

    NASA Astrophysics Data System (ADS)

    He, Xianqun; Xu, Chaoshui

    2016-04-01

    Rock cutting typically involves driving a rigid cutter across the rock surface at certain depth of cut and is used to remove rock material in various engineering applications. It has been established that there exist two distinct failure modes in rock cutting, i.e. ductile mode and brittle mode. The ductile mode takes precedence when the cut is shallow and the increase in the depth of cut leads to rock failure gradually shifted to brittle-dominant mode. The threshold depth or the critical transition depth, at which rock failure under cutting changes from the ductile to the brittle mode, is associated with not only the rock properties but also the cutting operational parameters and the understanding of this threshold is important to optimise the tool design and operational parameters. In this study, a new method termed the specific cutting energy transition model is proposed from an energy perspective which is demonstrated to be much more effective in identifying the critical transition depth compared with existing approaches. In the ductile failure cutting mode, the specific cutting energy is found to be independent of the depth of cut; but in the brittle failure cutting mode, the specific cutting energy is found to be dependent on the depth of cut following a power-law relationship. The critical transition depth is identified as the intersection point between these two relationships. Experimental tests on two types of rocks with different combinations of cutting velocity, depth of cut and back rake angle are conducted and the application of the proposed model on these cutting datasets has demonstrated that the model can provide a very effective tool to analyse the cutting mechanism and to identify the critical transition depth.

  20. LDEF data: Comparisons with existing models

    NASA Technical Reports Server (NTRS)

    Coombs, Cassandra R.; Watts, Alan J.; Wagner, John D.; Atkinson, Dale R.

    1993-01-01

    The relationship between the observed cratering impact damage on the Long Duration Exposure Facility (LDEF) versus the existing models for both the natural environment of micrometeoroids and the man-made debris was investigated. Experimental data was provided by several LDEF Principal Investigators, Meteoroid and Debris Special Investigation Group (M&D SIG) members, and by the Kennedy Space Center Analysis Team (KSC A-Team) members. These data were collected from various aluminum materials around the LDEF satellite. A PC (personal computer) computer program, SPENV, was written which incorporates the existing models of the Low Earth Orbit (LEO) environment. This program calculates the expected number of impacts per unit area as functions of altitude, orbital inclination, time in orbit, and direction of the spacecraft surface relative to the velocity vector, for both micrometeoroids and man-made debris. Since both particle models are couched in terms of impact fluxes versus impactor particle size, and much of the LDEF data is in the form of crater production rates, scaling laws have been used to relate the two. Also many hydrodynamic impact computer simulations were conducted, using CTH, of various impact events, that identified certain modes of response, including simple metallic target cratering, perforations and delamination effects of coatings.