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. Adaptive mode control in few mode fibers and its applications

    NASA Astrophysics Data System (ADS)

    Ashry, Islam; Lu, Peng; Xu, Yong

    2016-10-01

    With the development of mode-division-multiplexing (MDM), few mode fibers (FMFs) have found a wide range of applications in optical sensing and communications. However, how to precisely control the mode composition of optical signals in FMFs remains a difficult challenge. In this paper, we present an adaptive mode control method that can selectively excite the linearly polarized (LP) mode within the FMF. The method is based on using optical pulses reflected by a fiber Bragg grating (FBG) for wavefront optimization. Two potential applications are discussed. First, we theoretically demonstrate the feasibility of large scale multiplexing of absorption based fiber optical sensors. Second, we discuss the possibility of using mode dependent loss to reconstruct the spatial distributions of absorptive chemicals diffused within a FMF.

  3. 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... AND ARRANGEMENTS General Provisions § 117.15 Applicability to existing vessels. An existing vessel... and serviceable condition. (b) An existing vessel need not comply with § 117.78(a)(4) of this part....

  4. 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... AND ARRANGEMENTS General Provisions § 117.15 Applicability to existing vessels. An existing vessel... and serviceable condition. (b) An existing vessel need not comply with § 117.78(a)(4) of this part....

  5. MOF thin films: existing and future applications.

    PubMed

    Shekhah, O; Liu, J; Fischer, R A; Wöll, Ch

    2011-02-01

    The applications and potentials of thin film coatings of metal-organic frameworks (MOFs) supported on various substrates are discussed in this critical review. Because the demand for fabricating such porous coatings is rather obvious, in the past years several synthesis schemes have been developed for the preparation of thin porous MOF films. Interestingly, although this is an emerging field seeing a rapid development a number of different applications on MOF films were either already demonstrated or have been proposed. This review focuses on the fabrication of continuous, thin porous films, either supported on solid substrates or as free-standing membranes. The availability of such two-dimensional types of porous coatings opened the door for a number of new perspectives for functionalizing surfaces. Also for the porous materials themselves, the availability of a solid support to which the MOF-films are rigidly (in a mechanical sense) anchored provides access to applications not available for the typical MOF powders with particle sizes of a few μm. We will also address some of the potential and applications of thin films in different fields like luminescence, QCM-based sensors, optoelectronics, gas separation and catalysis. A separate chapter has been devoted to the delamination of MOF thin films and discusses the potential to use them as free-standing membranes or as nano-containers. The review also demonstrates the possibility of using MOF thin films as model systems for detailed studies on MOF-related phenomena, e.g. adsorption and diffusion of small molecules into MOFs as well as the formation mechanism of MOFs (101 references).

  6. 46 CFR 117.15 - Applicability to existing vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Applicability to existing vessels. 117.15 Section 117.15... AND ARRANGEMENTS General Provisions § 117.15 Applicability to existing vessels. An existing vessel... under §§ 117.202, 117.204, 117.205, 117.206, 117.207, or 117.208 of this part, as applicable; and...

  7. 28 CFR 0.32 - Applicability of existing departmental regulations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 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...

  8. Mode evolution in polarization maintain few mode fibers and applications in mode-division-multiplexing systems

    NASA Astrophysics Data System (ADS)

    Li, Yan; Zeng, Xinglin; Mo, Qi; Li, Wei; Liu, Zhijian; Wu, Jian

    2016-10-01

    In few-mode polarization-maintaining-fiber (FM-PMF), the effective-index splitting exists not only between orthogonally polarization state but also between degenerated modes within a high-order mode group. Hence besides the polarization state evolution, the mode patterns in each LP set are need to be analyzed. In this letter, the completed firstorder mode (LP11 mode) evolution in PM-FMF is analyzed and represented by analogous Jones vector and Poincarésphere respectively. Furthermore, with Jones matrix analysis, the modal dynamics in FM-PMFs is conveniently analyzed. The conclusions are used to propose a PM-FMF based LP11 mode rotator and an PM-FMF based OAM generator. Both simulation and experiments are conducted to investigate performance of the two devices.

  9. A criterion for the existence of zero modes for the Pauli operator with fastly decaying fields

    NASA Astrophysics Data System (ADS)

    Benguria, R. D.; Van Den Bosch, H.

    2015-05-01

    We consider the Pauli operator in ℝ3 for magnetic fields in L3/2 that decay at infinity as |x|-2-β with β > 0. In this case, we are able to prove that the existence of a zero mode for this operator is equivalent to a quantity δ(B), defined below, being equal to zero. Complementing a result from Balinsky et al. [J. Phys. A: Math. Gen. 34, L19-L23 (2001)], this implies that for the class of magnetic fields considered, Sobolev, Hardy, and Cwikel, Lieb, Rosenblum (CLR) inequalities hold whenever the magnetic field has no zero mode.

  10. 28 CFR 0.121 - Applicability of existing departmental regulations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... OF JUSTICE 1-Office of Community Oriented Policing Services § 0.121 Applicability of existing... grant programs administered by the Office of Community Oriented Policing Services, with references to... Community Oriented Policing Services, as appropriate. ...

  11. Existence of axisymmetric modes of thin cylindrical shells with axial displacement restraint

    NASA Technical Reports Server (NTRS)

    El-Raheb, M.

    1981-01-01

    A necessary and sufficient condition is derived for the existence of the axisymmetric mode of cylindrical shells with a radial displacement having one half wave along the axis and axial displacement restrained at both ends. The condition is purely geometric and consists of an upper bound on the mean radius of thickness ratio for a given fixed value of the length to mean radius ratio, above which the mode with one half wave in radial displacement along the axis ceases to exist. The proof is based on enforcing two basic lemmas concerned with the simplicity of the eigenvalues of the shell and the uniform ordering of these eigenvalues with the number of nodes of their corresponding radial displacement eigenfunctions.

  12. 28 CFR 0.121 - Applicability of existing departmental regulations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OF JUSTICE 1-Office of Community Oriented Policing Services § 0.121 Applicability of existing... Policing Services, Departmental regulations set forth in part 18 of this title, applicable to grant... grant programs administered by the Office of Community Oriented Policing Services, with references to...

  13. 28 CFR 0.121 - Applicability of existing departmental regulations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... OF JUSTICE 1-Office of Community Oriented Policing Services § 0.121 Applicability of existing... Policing Services, Departmental regulations set forth in part 18 of this title, applicable to grant... grant programs administered by the Office of Community Oriented Policing Services, with references to...

  14. 28 CFR 0.121 - Applicability of existing departmental regulations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... OF JUSTICE 1-Office of Community Oriented Policing Services § 0.121 Applicability of existing... Policing Services, Departmental regulations set forth in part 18 of this title, applicable to grant... grant programs administered by the Office of Community Oriented Policing Services, with references to...

  15. 28 CFR 0.121 - Applicability of existing departmental regulations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... OF JUSTICE 1-Office of Community Oriented Policing Services § 0.121 Applicability of existing... Policing Services, Departmental regulations set forth in part 18 of this title, applicable to grant... grant programs administered by the Office of Community Oriented Policing Services, with references to...

  16. 46 CFR 120.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... electrical installations, equipment, and material that were applicable to the vessel on March 10, 1996, or... MORE THAN 150 PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS ELECTRICAL INSTALLATION General Provisions § 120.115 Applicability to existing vessels. (a) Except as otherwise...

  17. 46 CFR 183.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 100 GROSS TONS) ELECTRICAL INSTALLATION General Provisions § 183.115 Applicability to existing vessels... comply with the regulations on electrical installations, equipment, and material that were applicable to... installations of electrical equipment and material, and the repair or replacement of wire and cable, on...

  18. 46 CFR 183.115 - Applicability to existing vessels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 100 GROSS TONS) ELECTRICAL INSTALLATION General Provisions § 183.115 Applicability to existing vessels... comply with the regulations on electrical installations, equipment, and material that were applicable to... installations of electrical equipment and material, and the repair or replacement of wire and cable, on...

  19. 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.

  20. 40 CFR 35.937-11 - Applicability to existing contracts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Applicability to existing contracts. 35.937-11 Section 35.937-11 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER... EPA policy with respect to these subagreements and must be implemented before the grant award...

  1. 40 CFR 35.937-11 - Applicability to existing contracts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Applicability to existing contracts. 35.937-11 Section 35.937-11 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER... EPA policy with respect to these subagreements and must be implemented before the grant award...

  2. 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

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

    PubMed

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

    2015-01-28

    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.

  4. Existence of solutions to nonlinear Hammerstein integral equations and applications

    NASA Astrophysics Data System (ADS)

    Li, Fuyi; Li, Yuhua; Liang, Zhanping

    2006-11-01

    In this paper, we study the existence and multiplicity of solutions of the operator equation Kfu=u in the real Hilbert space L2(G). Under certain conditions on the linear operator K, we establish the conditions on f which are able to guarantee that the operator equation has at least one solution, a unique solution, and infinitely many solutions, respectively. The monotone operator principle and the critical point theory are employed to discuss this problem, respectively. In argument, quadratic root operator K1/2 and its properties play an important role. As an application, we investigate the existence and multiplicity of solutions to fourth-order boundary value problems for ordinary differential equations with two parameters, and give some new existence results of solutions.

  5. 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.

  6. Application of variational mode decomposition to seismic random noise reduction

    NASA Astrophysics Data System (ADS)

    Liu, Wei; Cao, Siyuan; Wang, Zhiming

    2017-08-01

    We have proposed a new denoising method for the simultaneous noise reduction and preservation of seismic signals based on variational mode decomposition (VMD). VMD is a recently developed adaptive signal decomposition method and an advance in non-stationary signal analysis. It solves the mode-mixing and non-optimal reconstruction performance problems of empirical mode decomposition that have existed for a long time. By using VMD, a multi-component signal can be non-recursively decomposed into a series of quasi-orthogonal intrinsic mode functions (IMFs), each of which has a relatively local frequency range. Meanwhile, the signal will focus on a smaller number of obtained IMFs after decomposition, and thus the denoised result is able to be obtained by reconstructing these signal-dominant IMFs. Synthetic examples are given to demonstrate the effectiveness of the proposed approach and comparison is made with the complete ensemble empirical mode decomposition, which demonstrates that the VMD algorithm has lower computational cost and better random noise elimination performance. The application of on field seismic data further illustrates the superior performance of our method in both random noise attenuation and the recovery of seismic events.

  7. Polymer optical waveguide devices for mode-division-multiplexing applications

    NASA Astrophysics Data System (ADS)

    Chiang, Kin Seng

    2017-05-01

    Mode-division multiplexing (MDM), which allows different guided modes of a few-mode fiber to carry different signals, is a new technology being actively pursued worldwide to increase the signal-carrying capacity of a fiber. For the development of the MDM technology, many mode-controlling devices are needed, such as mode converters, mode (de)multiplexers, mode filters, and mode-selective switches. Among the various technologies available for the implementation of such devices, the polymer waveguide technology offers many distinct advantages. This paper presents a review of polymer waveguide devices for MDM applications, which include grating-based mode converters, 3D mode (de)multiplexers, graphene-based mode filters, and thermo-optic mode-selective switches.

  8. 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.

  9. 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.

  10. Existence of fermion zero modes and deconfinement of spinons in quantum antiferromagnetism resulting from algebraic spin liquid

    SciTech Connect

    Kim, Ki-Seok

    2005-12-01

    We investigate the quantum antiferromagnetism arising from algebraic spin liquid via spontaneous chiral symmetry breaking. We claim that in the antiferromagnet massive Dirac spinons can appear to make a broad continuum spectrum at high energies in inelastic neutron scattering. The mechanism of spinon deconfinement results from the existence of fermion zero modes in single monopole potentials. Neel vectors can make a hedgehog configuration around a magnetic monopole of compact U(1) gauge fields. Remarkably, in the monopole composite potential the Dirac fermion is shown to have a zero mode. The emergence of the fermion zero mode forbids the condensation of monopoles, resulting in deconfinement of Dirac spinons in the quantum antiferromagnet.

  11. 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.

  12. 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.

  13. Existence of Quasinormal Modes for Kerr-AdS Black Holes

    NASA Astrophysics Data System (ADS)

    Gannot, Oran

    2017-08-01

    This paper establishes the existence of quasinormal frequencies converging exponentially to the real axis for the Klein--Gordon equation on a Kerr-AdS spacetime when Dirichlet boundary conditions are imposed at the conformal boundary. The proof is adapted from results in Euclidean scattering about the existence of scattering poles generated by time-periodic approximate solutions to the wave equation.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. Mixed-mode chromatography and its applications to biopolymers.

    PubMed

    Yang, Yun; Geng, Xindu

    2011-12-09

    Mixed-mode chromatography is a type of chromatography in which a chromatographic stationary phase interacts with solutes through more than one interaction mode. This technique has been growing rapidly because of its advantages over conventional chromatography, such as its high resolution, high selectivity, high sample loading, high speed, and the ability to replace two conventionally corresponding columns in certain circumstances. In this work, some aspects of the development of mixed-mode chromatography are reviewed, such as stationary phase preparation, combinations of various separation modes, separation mechanisms, typical applications to biopolymers and peptides, and future prospects. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Exploitation of Existing Voice Over Internet Protocol Technology for Department of the Navy Application

    DTIC Science & Technology

    2002-09-01

    NAVAL POSTGRADUATE SCHOOL Monterey, California THESIS Approved for public release; distribution is unlimited EXPLOITATION OF EXISTING VOICE...Title (Mix case letters) Exploitation of Existing Voice over Internet Protocol Technology for Department of the Navy Application 6. AUTHOR(S...unlimited EXPLOITATION OF EXISTING VOICE OVER INTERNET PROTOCOL TECHNOLOGY FOR DEPARTMENT OF THE NAVY APPLICATION David T. Wallace Captain

  20. 40 CFR 125.61 - Existence of and compliance with applicable water quality standards.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... applicable water quality standards. 125.61 Section 125.61 Protection of Environment ENVIRONMENTAL PROTECTION... Water Act § 125.61 Existence of and compliance with applicable water quality standards. (a) There must exist a water quality standard or standards applicable to the pollutant(s) for which a section...

  1. 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... Water Act § 125.61 Existence of and compliance with applicable water quality standards. (a) There must exist a water quality standard or standards applicable to the pollutant(s) for which a section...

  2. 40 CFR 125.61 - Existence of and compliance with applicable water quality standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... applicable water quality standards. 125.61 Section 125.61 Protection of Environment ENVIRONMENTAL PROTECTION... Water Act § 125.61 Existence of and compliance with applicable water quality standards. (a) There must exist a water quality standard or standards applicable to the pollutant(s) for which a section...

  3. 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... Water Act § 125.61 Existence of and compliance with applicable water quality standards. (a) There must exist a water quality standard or standards applicable to the pollutant(s) for which a section...

  4. 40 CFR 125.61 - Existence of and compliance with applicable water quality standards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... applicable water quality standards. 125.61 Section 125.61 Protection of Environment ENVIRONMENTAL PROTECTION... Water Act § 125.61 Existence of and compliance with applicable water quality standards. (a) There must exist a water quality standard or standards applicable to the pollutant(s) for which a section...

  5. 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.

  6. Sensor applications of two-mode fiber in the Michelson interferometer configuration

    NASA Astrophysics Data System (ADS)

    Hlubina, Petr; Prochazka, Pavel

    1994-11-01

    The classical coherence formalism and guided-mode field representation is used to discuss the operation of few-mode fiber waveguide excited by a low-coherence, cross-spectrally pure, spatially coherent source in Michelson interferometer configuration as a sensor, even if a suppressed interference pattern at its exit face exists. In the case of a low- coherence excitation of few-mode fiber waveguide the principle of coherence modulation can be used, that is, the optical path difference between guided modes that exceeds the source coherence length can be compensated in Michelson interferometer configuration. The analysis of temporal coherence in a particular case of two-mode, weakly-guiding, step-index fiber waveguide takes also into consideration the effect of second-order modal dispersion; the potential applications to low- coherence source based interferometric sensors are discussed.

  7. Sliding mode control application in ABWR plant pressure regulation

    SciTech Connect

    Huang, Zhengyu; Edwards, Robert M.

    2002-07-01

    A sliding mode controller is designed for an ABWR nuclear power plant turbine throttle pressure regulation. To avoid chattering problem, which is common to conventional sliding mode controllers, and estimation of uncertainties and disturbances, the recursive-form sliding mode control algorithm is developed. To apply the sliding mode control technique, the original plant's 11.-order dynamics model is first transformed to a canonical form differential equation of a relative order of 2 for turbine throttle pressure's dynamics. Simulation results show that the design objectives are achieved and the resulting controller is superior to the existing PI controller in many aspects, including settling time, overshoot/undershoot in response to setpoint step input and fluctuation amplitude in the presence of external disturbances. (authors)

  8. Resonant mode controllers for launch vehicle applications

    NASA Astrophysics Data System (ADS)

    Schreiner, Ken E.; Roth, Mary Ellen

    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.

  9. 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.

  10. Normal-Mode Force APPROPRIATION—THEORY and Application

    NASA Astrophysics Data System (ADS)

    Wright, J. R.; Cooper, J. E.; Desforges, M. J.

    1999-03-01

    Normal-mode force appropriation is a method of physically exciting and measuring the undamped natural frequencies and normal-mode shapes of a structure which is distinct from the more common phase separation approaches. In this paper, the theory of normal modes and force appropriation is reviewed and a comparison made of a number of common force appropriation techniques. Both simulated and experimental data are used to highlight the relative merits of the different approaches, and comparisons to phase separation results are presented. Further advancements and applications of normal-mode testing—to non-proportionally damped structures, non-linear structures and consideration of the optimal exciter placement problem—are also discussed.

  11. Entanglement conditions for two-mode states: Applications

    SciTech Connect

    Hillery, Mark; Zubairy, M. Suhail

    2006-09-15

    We examine the implications of several recently derived conditions [Hillery and Zubairy, Phys. Rev. Lett. 96, 050503 (2006)] for determining when a two-mode state is entangled. We first find examples of non-Gaussian states that satisfy these conditions. We then apply the entanglement conditions to the study of several linear devices, the beam splitter, the parametric amplifier, and the linear phase-insensitive amplifier. For the first two, we find conditions on the input states that guarantee that the output states are entangled. For the linear amplifier, we determine in the limit of high and no gain, when an entangled input leads to an entangled output. Finally, we show how application of two two-mode entanglement conditions to a three-mode state can serve as a test of genuine three-mode entanglement.

  12. Discrete sliding mode control for robust tracking of higher order delay time systems with experimental application.

    PubMed

    Khandekar, A A; Malwatkar, G M; Patre, B M

    2013-01-01

    In this paper, a discrete time sliding mode controller (DSMC) is proposed for higher order plus delay time (HOPDT) processes. A sliding mode surface is selected as a function of system states and error and the tuning parameters of sliding mode controller are determined using dominant pole placement strategy. The condition for the existence of stable sliding mode is obtained by using Lyapunov function. The proposed method is applicable to HOPDT processes with oscillatory and integrating behavior, open loop instability or non-minimum phase characteristics and works satisfactory under the effect of parametric uncertainty. The method does not require reduced order model and provides simple way to design the controllers. The simulation and experimentation results show that the proposed method ensures desired tracking dynamics.

  13. 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.

  14. 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.

  15. 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.

  16. Necessary and sufficient conditions for the existence of time-dependent global attractor and application

    NASA Astrophysics Data System (ADS)

    Meng, Fengjuan; Liu, Cuncai

    2017-03-01

    In this paper, we are concerned with infinite dimensional dynamical systems in time-dependent space. First, we characterize some necessary and sufficient conditions for the existence of the time-dependent global attractor by using a measure of noncompactness. Then, we give a new method to verify the sufficient condition. As a simple application, we prove the existence of the time-dependent global attractor for the damped equation in strong topological space.

  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. 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 Estate...

  19. 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 Estate...

  20. 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 Estate...

  1. 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 Estate...

  2. 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 Estate...

  3. Integrating Existing Applications in Hypermedia Learning Material (General Issues & Experiences with OLE Technology).

    ERIC Educational Resources Information Center

    Borst Pauwels, H. W. J.; And Others

    The integration of existing applications in hypermedia environments is a promising approach towards more flexible and user-friendly hypermedia learning materials. A hypermedia courseware editor, called HyDE (Hypermedia Document Editor) was developed using Microsoft Windows TM OLE technology. OLE (object Linking and Embedding) stands for an…

  4. Photonic nanojet-induced modes: fundamentals and applications

    NASA Astrophysics Data System (ADS)

    Darafsheh, Arash; Lupu, Anatole; Burand, S. A.; Hutchens, Thomas C.; Fried, Nathaniel M.; Astratov, Vasily N.

    2012-01-01

    Photonic nanojet-induced modes (NIMs) have emerged as a new paradigm for understanding the optical properties of chains of dielectric microspheres with wavelength-scale diameters (D<=10λ). Here we show that light focusing and transport properties of chains of submillimeter spheres (D>100λ) are dominated by periodically focused modes (PFMs) which can be considered a geometrical optics analog of NIMs. We review recent geometrical optics results on this subject showing that Brewster angle conditions for TM polarized rays can be periodically reproduced in chains of spheres with index n= √3 =1.73205... giving rise to lossless PFMs with the 2D period. In this work we studied the phase properties of PFMs using a novel method based on Fourier analysis of the high resolution transmission spectra of chains of submillimeter ruby spheres with n~1.75 at λ=1.2 μm. We demonstrated that PFMs are the best surviving modes in long chains of spheres. Finally, we considered applications of PFMs for focusing multimodal beams in ultra-precise laser surgery.

  5. Guided-mode resonance nanophotonics: fundamentals and applications

    NASA Astrophysics Data System (ADS)

    Magnusson, Robert; Ko, Yeong Hwan

    2016-09-01

    We review principles and applications of nanophotonic devices based on electromagnetic resonance effects in thin periodic films. We discuss the fundamental resonance dynamics that are based on lateral Bloch modes excited by evanescent diffraction orders in these subwavelength devices. Theoretical and experimental results for selected example devices are furnished. Ultra-sparse nanogrids with duty cycle less than 10% are shown to provide substantially wide reflection bands and operate as effective polarizers. Narrow-passband resonant filters with extensive low sidebands are presented with focus on the zero-contrast grating architecture. This study is extended to long-wave operation in the THz region. Examples of fabricated guided-mode resonance devices with outstanding performance are given. This includes an unpolarized wideband reflector using serial single-layer reflectors, an ultra-sparse silicon nanowire grid as wideband reflector and polarizer, resonant bandpass filter with wide low sidebands, and a spatial/spectral filter permitting compact nonfocusing spatial filtering. The guided-mode resonance concept applies in all spectral regions, from the visible band to the microwave domain, with available low-loss materials.

  6. NEW APPLICATIONS IN THE INVERSION OF ACOUSTIC FULL WAVEFORM LOGS - RELATING MODE EXCITATION TO LITHOLOGY.

    USGS Publications Warehouse

    Paillet, Frederick L.; Cheng, C.H.; Meredith, J.A.

    1987-01-01

    Existing techniques for the quantitative interpretation of waveform data have been based on one of two fundamental approaches: (1) simultaneous identification of compressional and shear velocities; and (2) least-squares minimization of the difference between experimental waveforms and synthetic seismograms. Techniques based on the first approach do not always work, and those based on the second seem too numerically cumbersome for routine application during data processing. An alternative approach is tested here, in which synthetic waveforms are used to predict relative mode excitation in the composite waveform. Synthetic waveforms are generated for a series of lithologies ranging from hard, crystalline rocks (Vp equals 6. 0 km/sec. and Poisson's ratio equals 0. 20) to soft, argillaceous sediments (Vp equals 1. 8 km/sec. and Poisson's ratio equals 0. 40). The series of waveforms illustrates a continuous change within this range of rock properties. Mode energy within characteristic velocity windows is computed for each of the modes in the set of synthetic waveforms. The results indicate that there is a consistent variation in mode excitation in lithology space that can be used to construct a unique relationship between relative mode excitation and lithology.

  7. [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.

  8. Application of Contact Mode AFM to Manufacturing Processes

    NASA Astrophysics Data System (ADS)

    Giordano, Michael A.; Schmid, Steven R.

    A review of the application of contact mode atomic force microscopy (AFM) to manufacturing processes is presented. A brief introduction to common experimental techniques including hardness, scratch, and wear testing is presented, with a discussion of challenges in the extension of manufacturing scale investigations to the AFM. Differences between the macro- and nanoscales tests are discussed, including indentation size effects and their importance in the simulation of processes such as grinding. The basics of lubrication theory are presented and friction force microscopy is introduced as a method of investigating metal forming lubrication on the nano- and microscales that directly simulates tooling/workpiece asperity interactions. These concepts are followed by a discussion of their application to macroscale industrial manufacturing processes and direct correlations are made.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Existence and stability criteria for phase-locked modes in ring neural networks based on the spike time resetting curve method.

    PubMed

    Oprisan, Sorinel Adrian

    2010-01-21

    We developed a systematic and consistent mathematical approach to predicting 1:1 phase-locked modes in ring neural networks of spiking neurons based on the open loop spike time resetting curve (STRC) and its almost equivalent counterpart-the phase resetting curve (PRC). The open loop STRCs/PRCs were obtained by injecting into an isolated model neuron a triangular shaped time-dependent stimulus current closely resembling an actual synaptic input. Among other advantages, the STRC eliminates the confusion regarding the undefined phase for stimuli driving the neuron outside of the unperturbed limit cycle. We derived both open loop PRC and STRC-based existence and stability criteria for 1:1 phase-locked modes developed in ring networks of spiking neurons. Our predictions were in good agreement with the closed loop numerical simulations. Intuitive graphical methods for predicting phase-locked modes were also developed both for half-centers and for larger ring networks.

  15. Complex variational mode decomposition for signal processing applications

    NASA Astrophysics Data System (ADS)

    Wang, Yanxue; Liu, Fuyun; Jiang, Zhansi; He, Shuilong; Mo, Qiuyun

    2017-03-01

    Complex-valued signals occur in many areas of science and engineering and are thus of fundamental interest. The complex variational mode decomposition (CVMD) is proposed as a natural and a generic extension of the original VMD algorithm for the analysis of complex-valued data in this work. Moreover, the equivalent filter bank structure of the CVMD in the presence of white noise, and the effects of initialization of center frequency on the filter bank property are both investigated via numerical experiments. Benefiting from the advantages of CVMD algorithm, its bi-directional Hilbert time-frequency spectrum is developed as well, in which the positive and negative frequency components are formulated on the positive and negative frequency planes separately. Several applications in the real-world complex-valued signals support the analysis.

  16. 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.

  17. 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.

  18. Evidence of critical cooling rates in the nonisothermal crystallization of triacylglycerols: a case for the existence and selection of growth modes of a lipid crystal network.

    PubMed

    Bouzidi, Laziz; Narine, Suresh S

    2010-03-16

    The isoconversional method, a model-free analysis of the kinetics of liquid-solid transformations, was used to determine the effective activation energy of the nonisothermal crystallization of melts of pure and complex systems of triacylglycerols (TAGs). The method was applied to data from differential scanning calorimetry (DSC) measurements of the heat of crystallization of purified 1,3-dilauroyl-2-stearoyl-sn-glycerol (LSL) and commercially available cocoa butter melts. The method conclusively demonstrated the existence of specific growth modes and critical rates of cooling at specific degrees of conversion. The existence of critical rates suggests that the crystallization mechanism is composed of growth modes that can be effectively treated as mutually exclusive, each being predominant for one range of cooling rates and extent of conversion. Importantly, the data suggests that knowledge of the critical cooling rates at specific rates of conversion can be exploited to select preferred growth modes for lipid networks, with concomitant benefits of structural organization and resultant physical functionality. Differences in transport phenomena induced by different cooling rates suggest the existence of thresholds for particular growth mechanisms and help to explain the overall complexity of lipid crystallization. The results of this model-free analysis may be attributed to the relative importance of nucleation and growth at different stages of crystallization. A mechanistic explanation based on the competing effects of the thermodynamic driving force and limiting heat and transport phenomena is provided to explain the observed behavior. This work, furthermore, offers satisfactory explanations for the noted effect of cooling-rate-induced changes in the physical functionality of lipid networks.

  19. Developments in mode-locked lasers and their applications

    NASA Technical Reports Server (NTRS)

    Siegman, A. E.

    1982-01-01

    The most important recent advance with respect to mode locking has been the development of 'colliding-pulse' mode locking. An important extension to this method is reported. According to this extension, the colliding pulse function is obtained by making use of an 'antiresonant ring' laser cavity. The new concept has been applied to a flash-pumped passively mode-locked Nd:YAG laser in a number of experiments. Attention is given to mode locking of a self-pumped phase conjugate laser, picosecond photoacoustic experiments, and picosecond pulses on semiconductor surfaces.

  20. Acoustic mode coupling induced by nonlinear internal waves: evaluation of the mode coupling matrices and applications.

    PubMed

    Yang, T C

    2014-02-01

    This paper applies the mode coupling equation to calculate the mode-coupling matrix for nonlinear internal waves appearing as a train of solitons. The calculation is applied to an individual soliton up to second order expansion in sound speed perturbation in the Dyson series. The expansion is valid so long as the fractional sound speed change due to a single soliton, integrated over range and depth, times the wavenumber is smaller than unity. Scattering between the solitons are included by coupling the mode coupling matrices between the solitons. Acoustic fields calculated using this mode-coupling matrix formulation are compared with that obtained using a parabolic equation (PE) code. The results agree very well in terms of the depth integrated acoustic energy at the receivers for moving solitary internal waves. The advantages of using the proposed approach are: (1) The effects of mode coupling can be studied as a function of range and time as the solitons travel along the propagation path, and (2) it allows speedy calculations of sound propagation through a packet or packets of solitons saving orders of magnitude computations compared with the PE code. The mode coupling theory is applied to at-sea data to illustrate the underlying physics.

  1. Wideband TEM-TE11 mode convertor for HPM applications.

    NASA Astrophysics Data System (ADS)

    Bykov, D. N.; Bykov, N. M.; Kurkan, I. K.

    2017-05-01

    The mode convertor design of fundamental coaxial TEM to the lowest asymmetric TE11-mode of a circular waveguide was proposed and optimized with ANSYS HFSS software. It includes axially aligned parts: the input coaxial line with the high voltage insulator, conical coaxial matching line, wave-coax transition section and output circular waveguide. The most losses in this type of convertor caused by the wave of coaxial TE11-mode running back to the microwave source. To minimize these losses, there is the matching conical coaxial line with the cut-off insertion for coaxial TE11-mode. Characteristics of the convertor are as follows: the maximum input peak power - 3GW, the input impedance - 28Ohm, the central operating frequency - 1.14GHz. The power conversion efficiency to the output mode is from 90% upto 100% in the frequency band of 20%.

  2. The applicability of existing renovation methods in technology of screw compressors repairing

    NASA Astrophysics Data System (ADS)

    Kosenko, P. V.

    2017-08-01

    The article deals with the basic methods of machine parts recovery. Advantages and disadvantages of these methods had been widely spoken. The effect of these methods on the surface properties had been analysed. The main reasons of the wear of screw compressor parts are described in short. The authors paid attention to the evaluation of the applicability of existing renovation methods in technology of screw compressors repairing. In choosing the optimal method of renovation the surfaces of screw compressor parts are guided by the criteria of RAMS: reliability, availability, maintainability and safety. Also, it is specially noted about the evaluation of the effect of renovation methods on the screw surface layer by the following criteria: adhesion, ecological safety, cost, wear resistance, hardness, roughness, layer thickness, capacity, hogging, porousness, surface preparation, changes in the structure and physical properties of the base metal and ease of use. The most appropriate method for the renovation of parts of screw compressors had been proposed.

  3. An architecture for standardized terminology services by wrapping and integration of existing applications.

    PubMed

    Cornet, Roland; 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.

  4. 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

  5. Application of radio phase modes to modification and remote sensing of the atmosphere and space

    NASA Astrophysics Data System (ADS)

    Isham, B.; Mohammadi, S.; Chau, J.; Hysell, D. L.; Daldorff, L. K.; Thide, B.; Bergman, J.

    2009-12-01

    Radio phase modes are a low-frequency electromagnetic wave (radio) manifestation of photon orbital angular momentum (OAM) modes. At optical (laser) wavelengths OAM is an active area of theoretical and experimental research. Theory and modelling of radio phase modes show they may also easily be generated and, under certain conditions, detected with modern radio antenna arrays. Transimission of radio phase modes has been attempted using the HAARP HF transmitter in Alaska and the Jicamarca VHF radar in Peru. The HAARP experiment was designed to search for ionospheric modification effects of phase modes, while the Jicamarca experiment explored the possibility of using phase modes for remote sensing. Further work at Jicamarca will be aimed at verifying phase mode transmission and detection capabilities by using the moon as a reflector. Other potential applications of phase modes include the detection of radio OAM generated by astrophysical sources and their use in communications as a way of transmitting multiple signals at a single frequency.

  6. ON THE POSSIBLE EXISTENCE OF SHORT-PERIOD g-MODE INSTABILITIES POWERED BY NUCLEAR-BURNING SHELLS IN POST-ASYMPTOTIC GIANT BRANCH H-DEFICIENT (PG1159-TYPE) STARS

    SciTech Connect

    Corsico, A. H.; Althaus, L. G.; Miller Bertolami, M. M.; Kepler, S. O. E-mail: althaus@fcaglp.unlp.edu.ar E-mail: jgperez@iac.es

    2009-08-20

    We present a pulsational stability analysis of hot post-asymptotic giant branch (AGB) H-deficient pre-white dwarf stars with active He-burning shells. The stellar models employed are state-of-the-art equilibrium structures representative of PG1159 stars derived from the complete evolution of the progenitor stars, through the thermally pulsing AGB phase and born-again episode. On the basis of fully nonadiabatic pulsation computations, we confirmed theoretical evidence for the existence of a separate PG1159 instability strip in the log T {sub eff}-log g diagram characterized by short-period g-modes excited by the {epsilon}-mechanism. This instability strip partially overlaps the already known GW Vir instability strip of intermediate/long-period g-modes destabilized by the classical {kappa}-mechanism acting on the partial ionization of C and/or O in the envelope of PG1159 stars. We found that PG1159 stars characterized by thick He-rich envelopes and located inside this overlapping region could exhibit both short and intermediate/long periods simultaneously. As a natural application of our results, we study the particular case of VV 47, a pulsating planetary nebula nucleus (PG1159 type) that is particularly interesting because it has been reported to exhibit a rich and complex pulsation spectrum including a series of unusually short pulsation periods. We found that the long periods exhibited by VV 47 can be readily explained by the classical {kappa}-mechanism, while the observed short-period branch below {approx}300 s could correspond to modes triggered by the He-burning shell through the {epsilon}-mechanism, although more observational work is needed to confirm the reality of these short-period modes. Were the existence of short-period g-modes in this star convincingly confirmed by future observations, VV 47 could be the first known pulsating star in which both the {kappa}-mechanism and the {epsilon}-mechanism of mode driving are simultaneously operating.

  7. 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.

  8. Leveling data in geochemical mapping: scope of application, pros and cons of existing methods

    NASA Astrophysics Data System (ADS)

    Pereira, Benoît; Vandeuren, Aubry; Sonnet, Philippe

    2017-04-01

    Geochemical mapping successfully met a range of needs from mineral exploration to environmental management. In Europe and around the world numerous geochemical datasets already exist. These datasets may originate from geochemical mapping projects or from the collection of sample analyses requested by environmental protection regulatory bodies. Combining datasets can be highly beneficial for establishing geochemical maps with increased resolution and/or coverage area. However this practice requires assessing the equivalence between datasets and, if needed, applying data leveling to remove possible biases between datasets. In the literature, several procedures for assessing dataset equivalence and leveling data are proposed. Daneshfar & Cameron (1998) proposed a method for the leveling of two adjacent datasets while Pereira et al. (2016) proposed two methods for the leveling of datasets that contain records located within the same geographical area. Each discussed method requires its own set of assumptions (underlying populations of data, spatial distribution of data, etc.). Here we propose to discuss the scope of application, pros, cons and practical recommendations for each method. This work is illustrated with several case studies in Wallonia (Southern Belgium) and in Europe involving trace element geochemical datasets. References: Daneshfar, B. & Cameron, E. (1998), Leveling geochemical data between map sheets, Journal of Geochemical Exploration 63(3), 189-201. Pereira, B.; Vandeuren, A.; Govaerts, B. B. & Sonnet, P. (2016), Assessing dataset equivalence and leveling data in geochemical mapping, Journal of Geochemical Exploration 168, 36-48.

  9. 78 FR 69135 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-18

    ... existing standard to eliminate the use of blow-off dust covers for the spray nozzles of a deluge-type water... Request: The petitioner requests a modification of the existing standard to eliminate the use of blow-off... of the existing standard to eliminate the use of blow-off dust covers for the spray nozzles of...

  10. Mode-matching without root-finding: application to a dissipative silencer.

    PubMed

    Lawrie, Jane B; Kirby, Ray

    2006-04-01

    This article presents an analytic mode-matching approach suitable for modelling the propagation of sound in a two-dimensional, three-part, ducting system. The approach avoids the need to find roots of the characteristic equation for the middle section of the duct (the component) and is readily applicable to a broad class of problems. It is demonstrated that the system of equations, derived via analytic mode-matching, exhibits certain features which ensure that they can be recast into a form that is independent of the roots of the characteristic equation for the component. The precise details of the component are irrelevant to the procedure; it is required only that there exists an orthogonality relation, or similar, for the eigenmodes corresponding to the propagating wave forms in this region. The method is applied here to a simple problem involving acoustic transmission through a dissipative silencer of the type commonly found in heating ventilation and air-conditioning ducts. With reference to this example, the silencer transmission loss is computed, and the power balance for the silencer is investigated and is shown to be an identity that is necessarily satisfied by the system of equations, regardless of the level of truncation.

  11. Design of dual-mode optical fibres for the FTTH applications

    NASA Astrophysics Data System (ADS)

    Chen, Ming-Yang; Li, Yu-Rong; Zhang, Yin; Zhu, Yuan-Feng; Zhang, Yong-Kang; Zhou, Jun

    2011-01-01

    We present in this article a proposal and design for dual-mode optical fibres for fibre-to-the-home applications. High-order modes in the fibre can be effectively suppressed by the connection of the fibre with standard single-mode optical fibres at the two ends of the fibre. The alignment tolerance at the splicing process is presented. In particular, a low bending loss operation with low splice loss is demonstrated using the proposed technique.

  12. High power mode-locked semiconductor lasers and their applications

    NASA Astrophysics Data System (ADS)

    Lee, Shinwook

    In this dissertation, a novel semiconductor mode-locked oscillator which is an extension of eXtreme Chirped Pulse Amplification (XCPA) is investigated. An eXtreme Chirped Pulse Oscillator (XCPO) implemented with a Theta cavity also based on a semiconductor gain is presented for generating more than 30ns frequency-swept pulses with more than 100pJ of pulse energy and 3.6ps compressed pulses directly from the oscillator. The XCPO shows the two distinct characteristics which are the scalability of the output energy and the mode-locked spectrum with respect to repetition rate. The laser cavity design allows for low repetition rate operation <100MHz. The cavity significantly reduces nonlinear carrier dynamics, integrated self phase modulation (SPM), and fast gain recovery in a Semiconductor optical Amplifier (SOA). Secondly, a functional device, called a Grating Coupled Surface Emitting Laser (GCSEL) is investigated. For the first time, passive and hybrid mode-locking of a GCSEL is achieved by using saturable absorption in the passive section of GCSEL. To verify the present limitation of the GCSEL for passive and hybrid mode-locking, a dispersion matched cavity is explored. In addition, a Grating Coupled surface emitting Semiconductor Optical Amplifier (GCSOA) is also investigated to achieve high energy pulse. An energy extraction experiment for GCSOA using stretched pulses generated from the colliding pulse semiconductor mode-locked laser via a chirped fiber bragg grating, which exploits the XCPA advantages is also demonstrated. Finally, passive optical cavity amplification using an enhancement cavity is presented. In order to achieve the interferometric stability, the Hansch-Couillaud Method is employed to stabilize the passive optical cavity. The astigmatism-free optical cavity employing an acoustov optic modulator (AOM) is designed and demonstrated. In the passive optical cavity, a 7.2 of amplification factor is achieved with a 50 KHz dumping rate.

  13. Application of ultrasonic M-mode scanning and computer evaluation on urodynamics.

    PubMed

    Nishizawa, O; Harada, T; Moriya, I; Ohya, A; Satoh, S; Nakamura, H; Fukuda, T; Matsuzaki, A; Tsuchida, S

    1983-11-01

    The M-mode scanning images of urethra, detrusor pressure and urine flow rate during voiding were recorded together on the line scan recorder, and allowed for plotting and calculation of some valuable urodynamic parameters by computer evaluation. This procedure will permit first application of M-mode scanning and new direction on urodynamics.

  14. 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

  15. Application of mixed mode resins for the purification of antibodies.

    PubMed

    Voitl, Agnes; Müller-Späth, Thomas; Morbidelli, Massimo

    2010-09-10

    The downstream processing of monoclonal antibodies from cell culture supernatant is usually done by a number of chromatographic and non-chromatographic steps. Efforts are taken to reduce the costs associated to those steps, while maintaining a high product purity. A possibility to reach this goal is the reduction of the number of chromatographic steps using mixed mode resins that offer more than one functionality in one chromatographic step. In this work, a commercially available mixed mode resin was evaluated systematically with respect to the adsorption of proteins. The Henry coefficient, which quantifies the adsorption strength, was measured for the full working range of the stationary phase as a function of the salt concentration and the pH. The results were compared to a conventional anion exchange and a hydrophobic interaction resin. Furthermore, the resin was applied for the polishing step of an antibody from an industrial clarified cell culture supernatant.

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

    PubMed

    Caliendo, Cinzia

    2015-06-02

    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.

  17. 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

  18. Antiresonant ring interferometer for laser cavity dumping, mode locking, and other applications

    NASA Technical Reports Server (NTRS)

    Siegman, A. E.

    1975-01-01

    Applications in lasers for antiresonant ring interferometer include coupled laser cavities, variable laser-output coupling, intercavity harmonic-output coupling, mode locking, cavity dumping, and pulse code modulation.

  19. Multiwavelength arrays of mode-locked lasers for WDM applications

    NASA Astrophysics Data System (ADS)

    Davis, Lawrence J.; Young, Martin G.; Dougherty, David J.; Keo, Sam A.; Muller, Richard E.; Maker, Paul D.; Forouhar, Siamak

    1998-08-01

    The continued need for increased bandwidth is driving the pursuit of both increased speed in TDM and more channels in WDM for fiber optic communication systems. Multiwavelength arrays of monolithic mode-locked DBR lasers are an attractive source for future high bit rate (100 - 800 Gb/s) optical communication systems. Monolithic mode-locked lasers in the colliding-pulse mode-locked configuration have been fabricated, with DBR end mirrors for wavelength selection. A continuous gain region has been employed for ease of fabrication and the elimination of multiple reflections within the cavity. Arrays containing up to 9 wavelengths have been fabricated, with all the wavelengths within the erbium-doped fiber amplifier gain bandwidth. An RF signal is applied to the saturable absorber for synchronization to an external clock and reduction of the phase noise. For a 4.6 mm cavity, short (< 10 ps) optical pulses at high (approximately 18 GHz) repetition rates have been achieved. Low single side-band phase noise values (-107 dBc/Hz 100 kHz offset) have been demonstrated, nearly equal to that of the RF source.

  20. 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.

  1. 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.

  2. 40 CFR 63.1311 - Compliance dates and relationship of this subpart to existing applicable rules.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... subpart that are also subject to the provisions of 40 CFR part 60, subpart DDD, are required to comply... sources shall no longer be subject to 40 CFR part 60, subpart DDD. (2) Existing affected sources producing... provisions of 40 CFR part 60, subpart DDD. (3) Existing affected sources producing PET using a continuous...

  3. 40 CFR 63.1311 - Compliance dates and relationship of this subpart to existing applicable rules.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... subpart that are also subject to the provisions of 40 CFR part 60, subpart DDD, are required to comply... sources shall no longer be subject to 40 CFR part 60, subpart DDD. (2) Existing affected sources producing... provisions of 40 CFR part 60, subpart DDD. (3) Existing affected sources producing PET using a continuous...

  4. 40 CFR 63.1311 - Compliance dates and relationship of this subpart to existing applicable rules.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... subpart that are also subject to the provisions of 40 CFR part 60, subpart DDD, are required to comply... sources shall no longer be subject to 40 CFR part 60, subpart DDD. (2) Existing affected sources producing... provisions of 40 CFR part 60, subpart DDD. (3) Existing affected sources producing PET using a continuous...

  5. Selectively filled large-mode-area photonic crystal fiber for high power applications

    NASA Astrophysics Data System (ADS)

    Saini, Than S.; Kumar, Ajeet; Rastogi, Vipul; Sinha, Ravindra K.

    2013-09-01

    A large-mode-area (LMA) single-mode (SM) photonic crystal fiber (PCF) structure for applications in high power fiber lasers, amplifiers and sensors is proposed. In the proposed structure the center air hole has been removed to form the core and the six elliptical air holes of inner ring around the center core have been selectively filled with high refractive index material. Effects of design parameters on SM operation and mode area are numerically investigated by using the full vectorial finite-element method. Structure offers large-mode-area exceeding 835 μm2 at 1.064 μm wavelength. A PCF with such a large-mode-area would significantly reduce the nonlinear effects and would be useful for high power applications.

  6. 47 CFR 73.3538 - Application to make changes in an existing station.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... RADIO SERVICES RADIO BROADCAST SERVICES Rules Applicable to All Broadcast Stations § 73.3538 Application... of a main studio outside the principal community contour may require the filing and approval of...

  7. 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.

  8. 76 FR 37831 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-28

    ... states that: (1) The Troy Mine is an underground room and pillar mine with five stratabound copper/silver... the existing standard to permit an alternative method of compliance for leaving barrier pillars around...

  9. 76 FR 69764 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-09

    ... existing standard to eliminate the use of blow-off dust covers for the spray nozzles of a deluge-type water spray system. The petitioner states that: (1) As an alternative to using the blow-off dust covers,...

  10. A flexible dual-mode proximity sensor based on cooperative sensing for robot skin applications

    NASA Astrophysics Data System (ADS)

    Huang, Ying; Cai, Xia; Kan, Wenqing; Qiu, Shihua; Guo, Xiaohui; Liu, Caixia; Liu, Ping

    2017-08-01

    A flexible dual-mode proximity sensor has been designed and implemented, which is capable of combining capacitive-resistive detection in this paper. The capacitive type proximity sensor detecting is defined as mode-C, and the resistive type proximity sensor detecting is defined as mode-R. The characteristics of the proximity sensor are as follows: (1) the theoretical mode is developed which indicates that this proximity sensor can reflect proximity information accurately; (2) both sensing modes are vertically integrated into a sandwich-like chip with an 8 mm × 12 mm unit area. The thickness of a mode-R sensing material (graphene nanoplatelets) and mode-C dielectric (the mixture of carbon black and silicone rubber) is 1 mm and 2.5 mm, respectively; (3) for mode-R, the linearity of temperature-resistance curve can achieve 0.998 in the temperature range from 25°C to 65°C. And for mode-C, various materials can be successfully detected with fast response and high reversibility. Meanwhile, the study compensated the influence of object temperature to ensure mode-C properly works. A cooperative sensing test shows that R-C dual modes sense effectively which can enlarge the sensing distance compared with the single mode proximity sensor. The fabrication of this sensor is convenient, and the integrity of a flexible sandwich-like structure based on dual modes is beneficial to form arrays, which is suitable to be used in skin-like sensing applications.

  11. Global existence and uniqueness of classical solutions for a generalized quasilinear parabolic equation with application to a glioblastoma growth model.

    PubMed

    Wen, Zijuan; Fan, Meng; Asiri, Asim M; Alzahrani, Ebraheem O; El-Dessoky, Mohamed M; Kuang, Yang

    2017-04-01

    This paper studies the global existence and uniqueness of classical solutions for a generalized quasilinear parabolic equation with appropriate initial and mixed boundary conditions. Under some practicable regularity criteria on diffusion item and nonlinearity, we establish the local existence and uniqueness of classical solutions based on a contraction mapping. This local solution can be continued for all positive time by employing the methods of energy estimates, Lp-theory, and Schauder estimate of linear parabolic equations. A straightforward application of global existence result of classical solutions to a density-dependent diffusion model of in vitro glioblastoma growth is also presented.

  12. 76 FR 51058 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-17

    ... transmission gear blocking device and its proper application requirements. (4) The grader will comply with all... requirements. (4) The grader will comply with all other applicable requirements of the Federal Mine Safety and... Standards, Regulations and Variances. 4. Hand-Delivery or Courier: MSHA, Office of Standards,...

  13. 76 FR 22152 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-20

    ... operator or representative of miners to file a petition to modify the application of any mandatory safety standard to a coal or other mine if the Secretary determines that: (1) An alternative method of achieving... protection afforded the miners of such mine by such standard; or (2) that the application of such standard to...

  14. 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.

  15. 78 FR 35976 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-14

    ... and gas wells, and including water injection wells) until approval has been obtained from the District....1700 (Oil and gas wells). Modification Request: The petitioner requests a modification of the existing standard to permit an alternative method of compliance for the standard with respect to gas wells. The...

  16. 76 FR 64384 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-18

    ... modification will provide an equal degree of safety in that the supply of oxygen and drinking water would be...) (Deluge-type water spray system). 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...

  17. 78 FR 23308 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-18

    ... modification of the existing standard to permit the use of its slope belt as an alternate escapeway to transport miners. The petitioner states that: (1) The slope belt conveyor will be equipped with a backup generator to supply power to the slope belt in the event of power outage. (2) The slope belt conveyor will...

  18. 24 CFR 888.111 - Fair market rents for existing housing: Applicability.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 4 2014-04-01 2014-04-01 false Fair market rents for existing... HOUSING FOR PERSONS WITH DISABILITIES PROGRAM) SECTION 8 HOUSING ASSISTANCE PAYMENTS PROGRAM-FAIR MARKET RENTS AND CONTRACT RENT ANNUAL ADJUSTMENT FACTORS Fair Market Rents § 888.111 Fair market rents for...

  19. 24 CFR 888.111 - Fair market rents for existing housing: Applicability.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false Fair market rents for existing... HOUSING FOR PERSONS WITH DISABILITIES PROGRAM) SECTION 8 HOUSING ASSISTANCE PAYMENTS PROGRAM-FAIR MARKET RENTS AND CONTRACT RENT ANNUAL ADJUSTMENT FACTORS Fair Market Rents § 888.111 Fair market rents for...

  20. 24 CFR 888.111 - Fair market rents for existing housing: Applicability.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Fair market rents for existing... HOUSING FOR PERSONS WITH DISABILITIES PROGRAM) SECTION 8 HOUSING ASSISTANCE PAYMENTS PROGRAM-FAIR MARKET RENTS AND CONTRACT RENT ANNUAL ADJUSTMENT FACTORS Fair Market Rents § 888.111 Fair market rents for...

  1. 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 FOR PERSONS WITH DISABILITIES PROGRAM) SECTION 8 HOUSING ASSISTANCE PAYMENTS PROGRAM-FAIR MARKET RENTS AND CONTRACT RENT ANNUAL ADJUSTMENT FACTORS Fair Market Rents § 888.111 Fair market rents for...

  2. 24 CFR 888.111 - Fair market rents for existing housing: Applicability.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 4 2012-04-01 2012-04-01 false Fair market rents for existing... HOUSING FOR PERSONS WITH DISABILITIES PROGRAM) SECTION 8 HOUSING ASSISTANCE PAYMENTS PROGRAM-FAIR MARKET RENTS AND CONTRACT RENT ANNUAL ADJUSTMENT FACTORS Fair Market Rents § 888.111 Fair market rents for...

  3. Existence and switching behavior of bright and dark Kerr solitons in whispering-gallery mode resonators with zero group-velocity dispersion

    NASA Astrophysics Data System (ADS)

    Talla Mbé, Jimmi H.; Milián, Carles; Chembo, Yanne K.

    2017-07-01

    We use the generalized Lugiato-Lefever model to investigate the phenomenon of Kerr optical frequency comb generation when group-velocity dispersion is null. In that case, the first dispersion term that plays a leading role is third-order dispersion. We show that this term is sufficient to allow for the existence of both bright and dark solitons. We identify the areas in the parameter space where both kind of solitons can be excited inside the resonator. We also unveil a phenomenon of hysteretic switching between these two types of solitons when the power of the pump laser is cyclically varied. Contribution to the Topical Issue "Theory and Applications of the Lugiato-Lefever Equation", edited by Yanne K. Chembo, Damia Gomila, Mustapha Tlidi, Curtis R. Menyuk.

  4. 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.

  5. 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.

  6. On the application of frequency selective common mode feedback for multifrequency EIT.

    PubMed

    Langlois, Peter J; Wu, Yu; Bayford, Richard H; Demosthenous, Andreas

    2015-06-01

    Common mode voltages are frequently a problem in electrical impedance tomography (EIT) and other bioimpedance applications. To reduce their amplitude common mode feedback is employed. Formalised analyses of both current and voltage feedback is presented in this paper for current drives. Common mode effects due to imbalances caused by the current drives, the electrode connections to the body load and the introduction of the body impedance to ground are considered. Frequency selective narrowband common mode feedback previously proposed to provide feedback stability is examined. As a step towards multifrequency applications the use of narrowband feedback is experimentally demonstrated for two simultaneous current drives. Measured results using standard available components show a reduction of 62 dB for current feedback and 31 dB for voltage feedback. Frequencies ranged from 50 kHz to 1 MHz.

  7. Highly birefringent large mode area photonic crystal fiber-based sensor for interferometry applications

    NASA Astrophysics Data System (ADS)

    Ademgil, Huseyin

    2016-12-01

    In this work, highly birefringent large mode area (LMA) photonic crystal fiber (PCF) structure for interferometric sensor applications is proposed. The effective mode area, birefringence and the sensitivity coefficient of the proposed PCF structure by employing the full vectorial finite element method (FV-FEM) have been thoroughly investigated. The numerical results have shown that proposed structure simultaneously offers high birefringence of order 10-3, adequately LMA and high sensitivity for various liquid analytes by employing the elliptical liquid core holes.

  8. 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.

  9. 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.

  10. 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.

  11. Global existence of solutions of a strongly coupled quasilinear parabolic system with applications to electrochemistry

    NASA Astrophysics Data System (ADS)

    Choi, Y. S.; Huan, Zhongdan; Lui, Roger

    2003-11-01

    This paper consists of two parts. In the first part, we proved the global existence of weak solutions of a strongly coupled quasilinear parabolic system in Rn using weak compactness method. In the second part, we considered the electrochemistry model studied in Choi and Lui (J. Differential Equations 116 (1995) 306) where the Poisson equation governing the electric potential is replaced by a local electro-neutrality condition. In one space dimension, the equations for the model is of the form considered in the first part of this paper except that the coefficient matrix is discontinuous at places where all the charged ions vanish. We approximate the equations by nicer operators and pass to the limit to obtain global existence of weak solutions. The non-negativity of weak solutions and L2-stability of the steady-state solutions are also shown under additional hypotheses.

  12. The application of tapered multi-mode fiber in laser signal simulation

    NASA Astrophysics Data System (ADS)

    Yin, Ruiguang; Guo, Hao; Liang, Weiwei; Zhang, Wenpan; Li, Hui

    2016-09-01

    According to laser signal simulation, the advantage of application of tapered multi-mode fiber on laser pulse signal transmission was analyzed. By optical system simulation, the effect on the coupling efficiency of 1.06μm laser pulse signal of different angle was analyzed. By optical experiment, the coupling efficiency and transmission mode of different incident angle and force condition were confirmed. Combining the application of simulation system, with convex lens, frosted glass and optical integrator on the outlet of fiber, the far-field energy distribution was measured. According the receiving optical system entrance pupil, the effect on the beam quality to the simulation result was analyzed. The results showed that the application of tapered multi-mode fiber on laser pulse signal simulation is feasible, and the equipment has been used in the engineering projects.

  13. 40 CFR 63.481 - Compliance dates and relationship of this subpart to existing applicable rules.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... paragraph (e)(3). (f) Table 1 of this subpart specifies the provisions of subpart A that apply and those... of this subpart, Table 3 of subpart F is not applicable. (g) Table 2 of this subpart summarizes the... 265 subpart AA or CC and the owner or operator complies with the periodic reporting requirements under...

  14. 30 CFR 778.9 - Certifying and updating existing permit application information.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... information already in AVS is accurate and complete may certify to us by swearing or affirming, under oath and... corrections and swear or affirm, under oath and in writing, that the information you submit is accurate and... swear or affirm, under oath and in writing, that all information you provide in an application...

  15. 30 CFR 778.9 - Certifying and updating existing permit application information.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... information already in AVS is accurate and complete may certify to us by swearing or affirming, under oath and... corrections and swear or affirm, under oath and in writing, that the information you submit is accurate and... swear or affirm, under oath and in writing, that all information you provide in an application...

  16. 30 CFR 778.9 - Certifying and updating existing permit application information.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... information already in AVS is accurate and complete may certify to us by swearing or affirming, under oath and... corrections and swear or affirm, under oath and in writing, that the information you submit is accurate and... swear or affirm, under oath and in writing, that all information you provide in an application...

  17. 30 CFR 778.9 - Certifying and updating existing permit application information.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... information already in AVS is accurate and complete may certify to us by swearing or affirming, under oath and... corrections and swear or affirm, under oath and in writing, that the information you submit is accurate and... swear or affirm, under oath and in writing, that all information you provide in an application...

  18. 30 CFR 778.9 - Certifying and updating existing permit application information.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... information already in AVS is accurate and complete may certify to us by swearing or affirming, under oath and... corrections and swear or affirm, under oath and in writing, that the information you submit is accurate and... swear or affirm, under oath and in writing, that all information you provide in an application...

  19. Existence of Perpetual Points in Nonlinear Dynamical Systems and Its Applications

    NASA Astrophysics Data System (ADS)

    Prasad, Awadhesh

    A new class of critical points, termed as perpetual points, where acceleration becomes zero but the velocity remains nonzero, are observed in dynamical systems. The velocity at these points is either maximum or minimum or of inflection behavior. These points also show the bifurcation behavior as the parameters of the system vary. These perpetual points are useful for locating the hidden oscillating attractors as well as coexisting attractors. Results show that these points are important for a better understanding of transient dynamics in the phase space. The existence of these points confirms whether a system is dissipative or not. Various examples are presented, and the results are discussed analytically as well as numerically.

  20. 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.

  1. Reutericyclin: biological activity, mode of action, and potential applications.

    PubMed

    Gänzle, M G

    2004-04-01

    Reutericyclin is an inhibitory compound produced by sourdough isolates of Lactobacillus reuteri that is structurally but not functionally related to naturally occurring tetramic acids. It is bacteriostatic or bactericidal to gram-positive bacteria based on its activity as a proton-ionophore, and a broad range of food-related spoilage organisms and pathogens is inhibited by reutericyclin. Gram-negative bacteria are resistant to reutericyclin because of the barrier properties of their outer membrane, and resistance of beer-spoiling lactobacilli towards hop bitter acids provides cross-protection to reutericyclin. Remarkably, reutericyclin-producing strains were shown to persist for a period of 10 years in an industrial sourdough fermentation, and reutericyclin was shown to be produced in concentrations active against competitors during growth of L. reuteri in sourdough. Based on the known properties of reutericyclin and L. reuteri, reutericyclin-producing strains may have applications in the biopreservation of foods. Furthermore, these strains were shown to colonize reconstituted lactobacilli-free mice at high levels. Therefore, they could serve as a suitable model system to evaluate a possible impact of antimicrobial compounds on the intestinal microflora of humans and animals.

  2. Application of existing technology to meet increasing demands for automated sample handling.

    PubMed

    Chow, A T; Kegelman, J E; Kohli, C; McCabe, D D; Moore, J F

    1990-09-01

    As the clinical laboratory advances toward total automation, the marketplace is now demanding more-efficient sample-handling systems. These demands have arisen over a relatively short period of time, in part because of heightened concern over laboratory safety and the resulting manpower shortages. Adding sample-handling capabilities to existing instrumentation is often a challenge, because usually mechanical or system constraints are present that interfere. This challenge has been overcome in the DuPont Sample Management System (SMS), a second-generation general chemistry analyzer that incorporates the latest barcode and computer-interfacing technology. The development of the SMS system relies heavily on recent advances in technology, e.g., software modeling and computer-aided design. The SMS system includes a barcode scanner based on "charge-coupled device" technology, a random-access sample wheel, and new software that oversees the various functions.

  3. 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.

  4. The higher mode of surface wave derived from ambient noise and preliminary application to estimating subsurface

    NASA Astrophysics Data System (ADS)

    Zhentao, Y.; Xiaofei, C.; Jiannan, W.

    2016-12-01

    The fundamental mode is the primary component of surface wave derived from ambient noise. It is the basis of the method of structure imaging from ambient noise (e.g. SPAC, Aki 1957; F-K, Lascoss 1968; MUSIC, Schmidt 1986). It is well known, however, that if the higher modes of surface wave can be identified from data and are incorporated in the inversion of dispersion curves, the uncertainty in inversion results will be greatly reduced (e.g., Tokimastu,1997). Actually, the ambient noise indeed contains the higher modes as well in its raw data of ambient noise. If we could extract the higher modes from ambient noise, the structure inversion method of ambient noise would be greatly improved. In the past decade, there are many studies to improve SPAC and analyses the relationship of fundamental mode and higher mode (Ohri et al 2002; Asten et al. 2006; Tashiaki Ykoi 2010 ;Tatsunori Ikeda 2012). In this study, we will present a new method of identifying higher modes from ambient noise data by reprocessing the "surface waves' phases" derived from the ambient noise through cross-correlation analysis, and show preliminary application in structure inversion.

  5. 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

  6. Vascular Nature and Existence of Anastomoses of Extrinsic Postauricular Fascia: Application for Staged Auricular Reconstruction.

    PubMed

    Lohasammakul, Suphalerk; Turbpaiboon, Chairat; Chompoopong, Supin; Ratanalekha, Rosarin; Aojanepong, Chongdee

    2017-01-18

    A staged auricular reconstruction in microtia patients was developed by using superficial mastoid fascia (as part of extrinsic postauricular fascia) to cover the cartilagenous framework due to its highly vascularized nature. Three branches of external carotid artery (superficial temporal artery, posterior auricular artery and occipital artery) were found to supply this fascia, this study was therefore aimed to investigate the dimension of blood supply from each vessel and also to demonstrate the existence of anastomoses among these arteries. Thirty-eight pinnas and postauricular fascias from Thai fresh adult cadavers were included to document the anastomoses by showing both perfused dye connection (10 dissections) and visible anastomotic branches (8 dissections) among them. Distribution of each vessel trunk and its branches were demonstrated using superimposed illustration in the other 20 dissections with dye injection into each artery to designate 3 zones of anastomotic area between each arterial pair. Maximal size of viable postauricular fascial flap for staged reconstruction according to this vascular study was thus estimated to be at least 5 cm above and 3 cm below the Frankfurt horizontal plane and about 6 cm posterior to external acoustic meatus owing to the course of posterior auricular artery and its anastomoses. In addition, greater size of flap with dual blood supply from both superficial temporal and posterior auricular arteries can be raised by harvesting beyond 5 cm above external acoustic meatus.

  7. 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.

  8. Tokamak fluidlike equations, with applications to turbulence and transport in H mode discharges

    SciTech Connect

    Kim, Y.B.; Biglari, H.; Carreras, B.A.; Diamond, P.H.; Groebner, R.J.; Kwon, O.J.; Spong, D.A. ); Callen, J.D.; Chang, Z.; Hollenberg, J.B.; Sundaram, A.K.; Terry, P.W.; Wang, J.F. )

    1990-01-01

    Significant progress has been made in developing tokamak fluidlike equations which are valid in all collisionality regimes in toroidal devices, and their applications to turbulence and transport in tokamaks. The areas highlighted in this paper include: the rigorous derivation of tokamak fluidlike equations via a generalized Chapman-Enskog procedure in various collisionality regimes and on various time scales; their application to collisionless and collisional drift wave models in a sheared slab geometry; applications to neoclassical drift wave turbulence; i.e. neoclassical ion-temperature-gradient-driven turbulence and neoclassical electron-drift-wave turbulence; applications to neoclassical bootstrap-current-driven turbulence; numerical simulation of nonlinear bootstrap-current-driven turbulence and tearing mode turbulence; transport in Hot-Ion H mode discharges. 20 refs., 3 figs.

  9. New applications of Schrödinger type inequalities to the existence and uniqueness of Schrödingerean equilibrium.

    PubMed

    Wang, Jianjie; Roncalver, Hugo

    2017-01-01

    As new applications of Schrödinger type inequalities appearing in Jiang (J. Inequal. Appl. 2016:247, 2016), we first investigate the existence and uniqueness of a Schrödingerean equilibrium. Next we propose a tritrophic Hastings-Powell model with two different Schrödingerean time delays. Finally, the stability and direction of the Schrödingerean Hopf bifurcation are also investigated by using the center manifold theorem and normal form theorem.

  10. 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. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. AcceleRater: a web application for supervised learning of behavioral modes from acceleration measurements.

    PubMed

    Resheff, Yehezkel S; Rotics, Shay; Harel, Roi; Spiegel, Orr; Nathan, Ran

    2014-01-01

    The study of animal movement is experiencing rapid progress in recent years, forcefully driven by technological advancement. Biologgers with Acceleration (ACC) recordings are becoming increasingly popular in the fields of animal behavior and movement ecology, for estimating energy expenditure and identifying behavior, with prospects for other potential uses as well. Supervised learning of behavioral modes from acceleration data has shown promising results in many species, and for a diverse range of behaviors. However, broad implementation of this technique in movement ecology research has been limited due to technical difficulties and complicated analysis, deterring many practitioners from applying this approach. This highlights the need to develop a broadly applicable tool for classifying behavior from acceleration data. Here we present a free-access python-based web application called AcceleRater, for rapidly training, visualizing and using models for supervised learning of behavioral modes from ACC measurements. We introduce AcceleRater, and illustrate its successful application for classifying vulture behavioral modes from acceleration data obtained from free-ranging vultures. The seven models offered in the AcceleRater application achieved overall accuracy of between 77.68% (Decision Tree) and 84.84% (Artificial Neural Network), with a mean overall accuracy of 81.51% and standard deviation of 3.95%. Notably, variation in performance was larger between behavioral modes than between models. AcceleRater provides the means to identify animal behavior, offering a user-friendly tool for ACC-based behavioral annotation, which will be dynamically upgraded and maintained.

  12. 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.

  13. Accurate mode characterization of graded-index multimode fibers for the application of mode-noise analysis

    NASA Astrophysics Data System (ADS)

    Liu, Yueai; Rahman, B. M. A.; Ning, Ya Nong; Grattan, K. T. V.

    1995-03-01

    Guided modes in graded-index multimode optical fibers are accurately analyzed with the vector H-field finite-element method, aided by the use of the WKB method. As a result, exact mode-propagation constants and the corresponding modal eigenfield distributions are provided for the study of the modal noise that is due to the mode-coupling effect.

  14. 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.

  15. 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

  16. Valuing patients' experiences of healthcare processes: Towards broader applications of existing methods☆

    PubMed Central

    Ryan, Mandy; Kinghorn, Philip; Entwistle, Vikki A.; Francis, Jill J.

    2014-01-01

    Healthcare policy leaders internationally recognise that people's experiences of healthcare delivery are important, and invest significant resources to monitor and improve them. However, the value of particular aspects of experiences of healthcare delivery – relative to each other and to other healthcare outcomes – is unclear. This paper considers how economic techniques have been and might be used to generate quantitative estimates of the value of particular experiences of healthcare delivery. A recently published conceptual map of patients' experiences served to guide the scope and focus of the enquiry. The map represented both what health services and staff are like and do and what individual patients can feel like, be and do (while they are using services and subsequently). We conducted a systematic search for applications of economic techniques to healthcare delivery. We found that these techniques have been quite widely used to estimate the value of features of healthcare systems and processes (e.g. of care delivery by a nurse rather than a doctor, or of a consultation of 10 minutes rather than 15 minutes), but much less to estimate the value of the implications of these features for patients personally. To inform future research relating to the valuation of experiences of healthcare delivery, we organised a workshop for key stakeholders. Participants undertook and discussed ‘exercises’ that explored the use of different economic techniques to value descriptions of healthcare delivery that linked processes to what patients felt like and were able to be and do. The workshop identified a number of methodological issues that need careful attention, and highlighted some important concerns about the ways in which quantitative estimates of the value of experiences of healthcare delivery might be used. However the workshop confirmed enthusiasm for efforts to attend directly to the implications of healthcare delivery from patients' perspectives, including

  17. Review and analysis of existing mobile phone applications for health care-associated infection prevention.

    PubMed

    Schnall, Rebecca; Iribarren, Sarah J

    2015-06-01

    The expanding number of mobile health applications (apps) holds potential to reduce and eliminate health care-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. We searched 3 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, surgical site infection, and ventilator associated pneumonia [VAP]). 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%), and hand hygiene (n = 2, 11.8%); the remainder (n = 11, 64.7%) were focused on >1 area (eg, multiple infection prevention bundles, infection prevention guidelines). Almost all of the apps (70.6%) had a maximum of two functions. 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. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  18. 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.

  19. Respiratory motion correction for PET oncology applications using affine transformation of list mode data.

    PubMed

    Lamare, F; Cresson, T; Savean, J; Cheze Le Rest, C; Reader, A J; Visvikis, D

    2007-01-07

    Respiratory motion is a source of artefacts and reduced image quality in PET. Proposed methodology for correction of respiratory effects involves the use of gated frames, which are however of low signal-to-noise ratio. Therefore a method accounting for respiratory motion effects without affecting the statistical quality of the reconstructed images is necessary. We have implemented an affine transformation of list mode data for the correction of respiratory motion over the thorax. The study was performed using datasets of the NCAT phantom at different points throughout the respiratory cycle. List mode data based PET simulated frames were produced by combining the NCAT datasets with a Monte Carlo simulation. Transformation parameters accounting for respiratory motion were estimated according to an affine registration and were subsequently applied on the original list mode data. The corrected and uncorrected list mode datasets were subsequently reconstructed using the one-pass list mode EM (OPL-EM) algorithm. Comparison of corrected and uncorrected respiratory motion average frames suggests that an affine transformation in the list mode data prior to reconstruction can produce significant improvements in accounting for respiratory motion artefacts in the lungs and heart. However, the application of a common set of transformation parameters across the imaging field of view does not significantly correct the respiratory effects on organs such as the stomach, liver or spleen.

  20. 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

  1. 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.

  2. Fabrication strategies, sensing modes and analytical applications of ratiometric electrochemical biosensors.

    PubMed

    Jin, Hui; Gui, Rijun; Yu, Jianbo; Lv, Wei; Wang, Zonghua

    2017-05-15

    Previously developed electrochemical biosensors with single-electric signal output are probably affected by intrinsic and extrinsic factors. In contrast, the ratiometric electrochemical biosensors (RECBSs) with dual-electric signal outputs have an intrinsic built-in correction to the effects from system or background electric signals, and therefore exhibit a significant potential to improve the accuracy and sensitivity in electrochemical sensing applications. In this review, we systematically summarize the fabrication strategies, sensing modes and analytical applications of RECBSs. First, the different fabrication strategies of RECBSs were introduced, referring to the analytes-induced single- and dual-dependent electrochemical signal strategies for RECBSs. Second, the different sensing modes of RECBSs were illustrated, such as differential pulse voltammetry, square wave voltammetry, cyclic voltammetry, alternating current voltammetry, electrochemiluminescence, and so forth. Third, the analytical applications of RECBSs were discussed based on the types of target analytes. Finally, the forthcoming development and future prospects in the research field of RECBSs were also highlighted.

  3. Intensity information extraction in Geiger mode detector array based three-dimensional imaging applications

    NASA Astrophysics Data System (ADS)

    Wang, Fei

    2013-09-01

    Geiger-mode detectors have single photon sensitivity and picoseconds timing resolution, which make it a good candidate for low light level ranging applications, especially in the case of flash three dimensional imaging applications where the received laser power is extremely limited. Another advantage of Geiger-mode APD is their capability of large output current which can drive CMOS timing circuit directly, which means that larger format focal plane arrays can be easily fabricated using the mature CMOS technology. However Geiger-mode detector based FPAs can only measure the range information of a scene but not the reflectivity. Reflectivity is a major characteristic which can help target classification and identification. According to Poisson statistic nature, detection probability is tightly connected to the incident number of photon. Employing this relation, a signal intensity estimation method based on probability inversion is proposed. Instead of measuring intensity directly, several detections are conducted, then the detection probability is obtained and the intensity is estimated using this method. The relation between the estimator's accuracy, measuring range and number of detections are discussed based on statistical theory. Finally Monte-Carlo simulation is conducted to verify the correctness of this theory. Using 100 times of detection, signal intensity equal to 4.6 photons per detection can be measured using this method. With slight modification of measuring strategy, intensity information can be obtained using current Geiger-mode detector based FPAs, which can enrich the information acquired and broaden the application field of current technology.

  4. Bend-insensitive single-mode photonic crystal fiber with ultralarge effective area for dual applications

    NASA Astrophysics Data System (ADS)

    Islam, Md. Asiful; Alam, M. Shah

    2013-05-01

    A novel photonic crystal fiber (PCF) having circular arrangement of cladding air holes has been designed and numerically optimized to obtain a bend insensitive single mode fiber with large mode area for both wavelength division multiplexing (WDM) communication and fiber-to-the-home (FTTH) application. The bending loss of the proposed bent PCF lies in the range of 10-3 to 10-4 dB/turn or lower over 1300 to 1700 nm, and 2 × 10-4 dB/turn at the wavelength of 1550 nm for a 30-mm bend radius with a higher order mode (HOM) cut-off frequency below 1200 nm for WDM application. When the whole structure of the PCF is scaled down, a bending loss of 6.78×10-4 dB/turn at 1550 nm for a 4-mm bend radius is obtained, and the loss remains in the order of 10-4 dB/turn over the same range of wavelength with an HOM cut-off frequency below 700 nm, and makes the fiber useful for FTTH applications. Furthermore, this structure is also optimized to show a splice loss near zero for fusion-splicing to a conventional single-mode fiber (SMF).

  5. Application of empirical mode decomposition in removing fidgeting interference in doppler radar life signs monitoring devices.

    PubMed

    Mostafanezhad, Isar; Boric-Lubecke, Olga; Lubecke, Victor; Mandic, Danilo P

    2009-01-01

    Empirical Mode Decomposition has been shown effective in the analysis of non-stationary and non-linear signals. As an application in wireless life signs monitoring in this paper we use this method in conditioning the signals obtained from the Doppler device. Random physical movements, fidgeting, of the human subject during a measurement can fall on the same frequency of the heart or respiration rate and interfere with the measurement. It will be shown how Empirical Mode Decomposition can break the radar signal down into its components and help separate and remove the fidgeting interference.

  6. 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.

  7. Application of sliding mode methods to the design of reconfigurable flight control systems

    NASA Astrophysics Data System (ADS)

    Wells, Scott Russell

    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.

  8. 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.

  9. High-sensitivity ultrasound interferometric single-mode polymer optical fiber sensors for biomedical applications.

    PubMed

    Gallego, Daniel; Lamela, Horacio

    2009-06-15

    This work describes the results of ultrasonic wideband sensors based on single-mode polymer optical fibers that may be used for biomedical applications. We have compared the ultrasonic sensitivities of two Mach-Zehnder interferometric intrinsic optical fiber sensors. One is based on a single-mode polymethylmethacrylate optical fiber and the second on single-mode silica optical fiber, both operating at 632.8 nm. At a frequency of 1 MHz these sensitivities are 13.1 and 0.85 mrad/kPa, respectively. The ultrasonic phase sensitivity of the polymer optical fiber is more than 12 times larger than that from the fused silica fiber in the 1-5 MHz range.

  10. 45 CFR 2521.90 - If I am a new or replacement legal applicant for an existing program, what will my matching...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... matching requirements be? If your organization is a new or replacement legal applicant for an existing program, you must provide matching resources at the level the previous legal applicant had reached at...

  11. 45 CFR 2521.90 - If I am a new or replacement legal applicant for an existing program, what will my matching...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... matching requirements be? If your organization is a new or replacement legal applicant for an existing program, you must provide matching resources at the level the previous legal applicant had reached at...

  12. Application of failure mode and effects analysis to intracranial stereotactic radiation surgery by linear accelerator.

    PubMed

    Masini, Laura; Donis, Laura; Loi, Gianfranco; Mones, Eleonora; Molina, Elisa; Bolchini, Cesare; Krengli, Marco

    2014-01-01

    The aim of this study was to analyze the application of the failure modes and effects analysis (FMEA) to intracranial stereotactic radiation surgery (SRS) by linear accelerator in order to identify the potential failure modes in the process tree and adopt appropriate safety measures to prevent adverse events (AEs) and near-misses, thus improving the process quality. A working group was set up to perform FMEA for intracranial SRS in the framework of a quality assurance program. FMEA was performed in 4 consecutive tasks: (1) creation of a visual map of the process; (2) identification of possible failure modes; (3) assignment of a risk probability number (RPN) to each failure mode based on tabulated scores of severity, frequency of occurrence and detectability; and (4) identification of preventive measures to minimize the risk of occurrence. The whole SRS procedure was subdivided into 73 single steps; 116 total possible failure modes were identified and a score of severity, occurrence, and detectability was assigned to each. Based on these scores, RPN was calculated for each failure mode thus obtaining values from 1 to 180. In our analysis, 112/116 (96.6%) RPN values were <60, 2 (1.7%) between 60 and 125 (63, 70), and 2 (1.7%) >125 (135, 180). The 2 highest RPN scores were assigned to the risk of using the wrong collimator's size and incorrect coordinates on the laser target localizer frame. Failure modes and effects analysis is a simple and practical proactive tool for systematic analysis of risks in radiation therapy. In our experience of SRS, FMEA led to the adoption of major changes in various steps of the SRS procedure.

  13. Excitation of internal m = 1 mode during application of resonant magnetic perturbations on J-TEXT tokamak

    NASA Astrophysics Data System (ADS)

    Li, Jianchao; Hu, Qiming; Ding, Yonghua; Zhang, Xiaoqing; Yu, Qingquan; Yang, Zhoujun; Chen, Zhipeng; Li, Da; Rao, Bo; Wang, Nengchao; Zhuang, Ge; the J-TEXT Team

    2017-08-01

    The excitation of internal m = 1 mode during application of resonant magnetic perturbations (RMPs) is observed on J-TEXT tokamak. It is found that the sawtooth oscillation disappears after RMPs penetration, and subsequently an internal m = 1 mode with a frequency around 2 kHz appears, were m and n are the poloidal and toroidal mode numbers, respectively. In addition, the internal m = 1 mode often coexists with a rotating m/n = 2/1 tearing mode, and its frequency increases by about 0.5 kHz when the 2/1 tearing mode is locked by RMPs. The bispectrum analysis proves that the m = 1 mode interacts with the rotating 2/1 tearing mode, which implies the mode coupling between these two modes. The frequency of m = 1 mode increases for higher electron density. These results reveal that, the internal m = 1 mode can be excited by RMPs and coexist with both locked and rotating 2/1 mode due to toroidal mode coupling.

  14. 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.

  15. 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.

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

    NASA Technical Reports Server (NTRS)

    Liu, Yuan; Litt, Jonathan; Sowers, T. Shane; Owen, A. Karl; 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.

  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. Correction of Motion Artifacts From Shuttle Mode Computed Tomography Acquisitions for Body Perfusion Imaging Applications.

    PubMed

    Ghosh, Payel; Chandler, Adam G; Altinmakas, Emre; Rong, John; Ng, Chaan S

    2016-01-01

    The aim of this study was to investigate the feasibility of shuttle-mode computed tomography (CT) technology for body perfusion applications by quantitatively assessing and correcting motion artifacts. Noncontrast shuttle-mode CT scans (10 phases, 2 nonoverlapping bed locations) were acquired from 4 patients on a GE 750HD CT scanner. Shuttling effects were quantified using Euclidean distances (between-phase and between-bed locations) of corresponding fiducial points on the shuttle and reference phase scans (prior to shuttle mode). Motion correction with nonrigid registration was evaluated using sum-of-squares differences and distances between centers of segmented volumes of interest on shuttle and references images. Fiducial point analysis showed an average shuttling motion of 0.85 ± 1.05 mm (between-bed) and 1.18 ± 1.46 mm (between-phase), respectively. The volume-of-interest analysis of the nonrigid registration results showed improved sum-of-squares differences from 2950 to 597, between-bed distance from 1.64 to 1.20 mm, and between-phase distance from 2.64 to 1.33 mm, respectively, averaged over all cases. Shuttling effects introduced during shuttle-mode CT acquisitions can be computationally corrected for body perfusion applications.

  1. Triple-mode single-transistor graphene amplifier and its applications.

    PubMed

    Yang, Xuebei; Liu, Guanxiong; Balandin, Alexander A; Mohanram, Kartik

    2010-10-26

    We propose and experimentally demonstrate a triple-mode single-transistor graphene amplifier utilizing a three-terminal back-gated single-layer graphene transistor. The ambipolar nature of electronic transport in graphene transistors leads to increased amplifier functionality as compared to amplifiers built with unipolar semiconductor devices. The ambipolar graphene transistors can be configured as n-type, p-type, or hybrid-type by changing the gate bias. As a result, the single-transistor graphene amplifier can operate in the common-source, common-drain, or frequency multiplication mode, respectively. This in-field controllability of the single-transistor graphene amplifier can be used to realize the modulation necessary for phase shift keying and frequency shift keying, which are widely used in wireless applications. It also offers new opportunities for designing analog circuits with simpler structure and higher integration densities for communications applications.

  2. Effects of antiperspirant aluminum percent composition and mode of application on mock microcalcifications in mammography.

    PubMed

    Mesurolle, Benoît; Ceccarelli, Joan; Karp, Igor; Sun, Simon; El-Khoury, Mona

    2014-02-01

    Active ingredients in antiperspirants - namely, aluminum-based complexes - can produce radiopaque particles on mammography, mimicking microcalcifications. The present study was designed to investigate whether the appearance of antiperspirant induced radiopaque particles observed on mammograms is dependent on the percentage of aluminum-based complexes in antiperspirants and/or on their mode of application. A total of 43 antiperspirants with aluminum-based complex percentages ranging between 16% and 25% were tested. Each antiperspirant was applied to a single use plastic shield and then placed on an ultrasound gel pad, simulating breast tissue. Two experiments were performed, comparing antiperspirants based on (1) their percentage of aluminum-based complexes (20 antiperspirants) and (2) their mode of applications (solid, gel, and roll-on) (26 antiperspirants). Two experienced, blinded radiologists read images produced in consensus and assessed the appearance of radiopaque particles based on their density and shape. In experiment 1, there was no statistically significant association between the percent aluminum composition of invisible solid antiperspirants and the density or shape of the radiopaque particles (p-values>0.05). In experiment 2, there was a statistically significant association between the shape of the radiopaque particles and the mode of application of the antiperspirant (p-value=0.0015). Our study suggests that the mammographic appearance of the radiopaque antiperspirant particles is not related to their percent composition of aluminum complexes. However, their mode of application appears to influence the shape of radiopaque particles, solid antiperspirants mimicking microcalcifications the most and roll-on antiperspirants the least. Copyright © 2013. Published by Elsevier Ireland Ltd.

  3. V L Ginzburg’s helical elliptically polarized modes and their application

    NASA Astrophysics Data System (ADS)

    Malykin, G. B.

    2017-03-01

    In 1943, V L Ginzburg derived a simple and elegant solution to the polarization optics problem when a linear birefringent medium is uniformly twisted along the optical axis. In a torsion-comoving coordinate frame, mutually orthogonal polarization eigenmodes, i.e., helical modes, of such an optical medium are characterized by two ellipses with the electric field vector of light bypassed in the opposite sense. Current applications of V L Ginzburg’s theory are reviewed.

  4. Transadmittance Mode First Order LP/HP/AP Filter and its Application as an Oscillator

    NASA Astrophysics Data System (ADS)

    Nand, Deva; Pandey, Neeta

    2017-08-01

    In this paper new transadmittance mode first order low pass, high pass and all pass filter topologies using operational floating current conveyor (OFCC) is proposed and its application as an oscillator is also put forward. This proposal offers all filter functions at high impedance. Only two OFCCs, two resistors and one grounded capacitor are employed for realization. Workability is verified through SPICE simulations and results conform to the theoretical predictions very well. The proposed circuit is prototyped and tested experimentally for its application as an oscillator.

  5. 40 CFR 62.15400 - When must I submit a title V permit application for my existing small municipal waste combustion...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application for my existing small municipal waste combustion unit? 62.15400 Section 62.15400 Protection of... Combustion Units Constructed on or Before August 30, 1999 Title V Requirements § 62.15400 When must I submit a title V permit application for my existing small municipal waste combustion unit? (a) You...

  6. 40 CFR 62.15400 - When must I submit a title V permit application for my existing small municipal waste combustion...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application for my existing small municipal waste combustion unit? 62.15400 Section 62.15400 Protection of... Combustion Units Constructed on or Before August 30, 1999 Title V Requirements § 62.15400 When must I submit a title V permit application for my existing small municipal waste combustion unit? (a) You...

  7. 40 CFR 62.15400 - When must I submit a title V permit application for my existing small municipal waste combustion...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... application for my existing small municipal waste combustion unit? 62.15400 Section 62.15400 Protection of... Combustion Units Constructed on or Before August 30, 1999 Title V Requirements § 62.15400 When must I submit a title V permit application for my existing small municipal waste combustion unit? (a) You must...

  8. 40 CFR 62.15400 - When must I submit a title V permit application for my existing small municipal waste combustion...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... application for my existing small municipal waste combustion unit? 62.15400 Section 62.15400 Protection of... Combustion Units Constructed on or Before August 30, 1999 Title V Requirements § 62.15400 When must I submit a title V permit application for my existing small municipal waste combustion unit? (a) You must...

  9. 40 CFR 62.15400 - When must I submit a title V permit application for my existing small municipal waste combustion...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... application for my existing small municipal waste combustion unit? 62.15400 Section 62.15400 Protection of... Combustion Units Constructed on or Before August 30, 1999 Title V Requirements § 62.15400 When must I submit a title V permit application for my existing small municipal waste combustion unit? (a) You must...

  10. 45 CFR 2521.90 - If I am a new or replacement legal applicant for an existing program, what will my matching...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 4 2013-10-01 2013-10-01 false If I am a new or replacement legal applicant for an existing program, what will my matching requirements be? 2521.90 Section 2521.90 Public Welfare... Requirements § 2521.90 If I am a new or replacement legal applicant for an existing program, what will my...

  11. [Engineering management mode of mollusciciding and assessment of its field application].

    PubMed

    Gao, Yang; Sun, Le-Ping; Zuo, Yin-Ping; Hong, Qing-Biao; Liang, You-Sheng

    2012-08-01

    To establish the engineering management mode of mollusciciding, and assess its snail control effect in field application, so as to provide the effective management interventions for improving the quality of mollusciciding in the field. Engineering management of mollusciciding was performed. The snail distribution was surveyed before and after snail control with molluscicides and environmental modification, and the database was established. The snail control effect of the engineering management mode of mollusciciding was assessed. Engineering management mode of mollusciciding was conducted in 96.27% (1 033/1 073) of the total snail habitats in 6 counties (districts) of Yangzhou City from 2006 to 2011. After the implementation of engineering management mode, the mortality of snails increased from 65.07% before implementation to 87.16% (80.65%-89.38%), and significant difference was observed (chi2 = 4 623.297, P = 0). The reductions in occurrence rate of frames with snails and snail density and the corrected mortality of snails were 57.67% (49.27%-66.98%), 76.67% (76.13%-83.66%) and 86.58% (79.89%-88.89%), respectively, which were 1.45, 1.63 times and 1.37 times more than those before implementation. After the implementation of engineering management mode of mollusciciding for 3 years in Yangzhou City, all infected snails were eliminated. After 6 years of implementation, the number of settings with snails, snail areas, occurrence rate of frames with snails, means snail density decreased by 56.27%, 76.40%, 67.99% and 66.67%, respectively. High-quality molluscicide is the essential factor to ensure the molluscicidal effect, and engineering management mode of mollusciciding is an effective approach to improve the quality of snail control with molluscicides in the field.

  12. Effect of application mode on interfacial morphology and chemistry between dentine and self-etch adhesives.

    PubMed

    Zhang, Ying; Wang, Yong

    2013-03-01

    To investigate the influence of application mode on the interfacial morphology and chemistry between dentine and self-etch adhesives with different aggressiveness. 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 dentine slabs were prepared by sectioning the tooth specimens perpendicular to the abraded surfaces. The obtained dentine 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 dentine slabs were fractured and the exposed adhesive/dentine (A/D) interfaces were examined with micro-Raman spectroscopy and scanning electron microscopy (SEM). The interfacial morphology, degree of dentine 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 dentine 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 dentine in the above observations. The chemical interaction with dentine 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. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Aggravation of Pre-Existing Atrioventricular Block, Wenckebach Type, Provoked by Application of X-Ray Contrast Medium

    SciTech Connect

    Brodmann, Marianne Seinost, Gerald; Stark, Gerhard; Pilger, Ernst

    2006-12-15

    Background. Significant bradycardia followed by cardiac arrest related to single bolus administration of X-ray contrast medium into a peripheral artery has not, to our knowledge, been described in the literature. Methods and Results. While performing a percutaneous transluminal angioplasty of the left superficial femoral artery in a 68-year old patient with a pre-existing atrioventricular (AV) block, Wenckebach type, he developed an AV block III after a single bolus injection of intra-arterial X-ray contrast medium. Conclusion. We believe that application of contrast medium causes a transitory ischemia in the obstructed vessel and therefore elevation of endogenous adenosine. In the case of a previously damaged AV node this elevation of endogenous adenosine may be responsible for the development of a short period of third-degree AV block.

  14. Does active application of universal adhesives to enamel in self-etch mode improve their performance?

    PubMed

    Loguercio, Alessandro D; Muñoz, Miguel Angel; Luque-Martinez, Issis; Hass, Viviane; Reis, Alessandra; Perdigão, Jorge

    2015-09-01

    To evaluate the effect of adhesion strategy on the enamel microshear bond strengths (μSBS), etching pattern, and in situ degree of conversion (DC) of seven universal adhesives. 84 extracted third molars were sectioned in four parts (buccal, lingual, proximal) and divided into 21 groups, according to the combination of the main factors adhesive (AdheSE Universal [ADU], All-Bond Universal [ABU], Clearfil Universal [CFU], Futurabond U [FBU], G-Bond Plus [GBP], Prime&Bond Elect (PBE), and Scotchbond Universal Adhesive [SBU]), and adhesion strategy (etch-and-rinse, active self-etch, and passive self-etch). Specimens were stored in water (37°C/24h) and tested at 1.0mm/min (μSBS). Enamel-resin interfaces were evaluated for DC using micro-Raman spectroscopy. The enamel-etching pattern was evaluated under a field-emission scanning electron microscope (direct and replica techniques). Data were analyzed with two-way ANOVA and Tukey's test (α=0.05). Active self-etch application increased μSBS and DC for five out of the seven universal adhesives when compared to passive application (p<0.001). A deeper enamel-etching pattern was observed for all universal adhesives in the etch-and-rinse strategy. A slight improvement in etching ability was observed in active self-etch application compared to that of passive self-etch application. Replicas of GBP and PBE applied in active self-etch mode displayed morphological features compatible with water droplets. The DC of GBP and PBE were not affected by the application/strategy mode. In light of the improved performance of universal adhesives when applied actively in SE mode, selective enamel etching with phosphoric acid may not be crucial for their adhesion to enamel. The active application of universal adhesives in self-etch mode may be a practical alternative to enamel etching in specific clinical situations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. 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.

  16. 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.

  17. 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.

  18. General Applicable Frequency Map for the Amide-I Mode in β-Peptides.

    PubMed

    Cai, Kaicong; Du, Fenfen; Zheng, Xuan; Liu, Jia; Zheng, Renhui; Zhao, Juan; Wang, Jianping

    2016-02-18

    In this work, a general applicable amide-I vibrational frequency map (GA map) for β-peptides in a number of common solvents was constructed, based on a peptide derivative, N-ethylpropionamide (NEPA). The map utilizes force fields at the ab initio computational level to accurately describe molecular structure and solute-solvent interactions, and also force fields at the molecular mechanics level to take into account long-range solute-solvent interactions. The results indicate that the GA map works reasonably for mapping the vibrational frequencies of the amide-I local-modes for β-peptides, holding promises for understanding the complicated infrared spectra of the amide-I mode in β-polypeptides.

  19. Characteristics of 10 mm Multilayer L1-F2 Mode Vibrator and Application to a Linear Motor

    NASA Astrophysics Data System (ADS)

    Funakubo, Tomoki; Tomikawa, Yoshiro

    2003-05-01

    In the present paper we discuss a small-sized multilayer L1-F2 mode vibrator and its application to an ultrasonic linear motor. In an attempt to reduce both the size and the driving voltage of an L1-F2 mode vibrator, we constructed a multilayer L1-F2 mode vibrator whose inner electrodes are simply divided into two. Test results clarified that the multilayer L1-F2 mode vibrator exhibits two resonance modes; namely, a first longitudinal mode and a second flexural mode, and that an amplitude of vibration velocity is sufficiently large for application to a linear motor. Specific merits of our multilayer L1-F2 mode vibrator are that the driving voltage is low (5 Vrms), owing to multilayer construction, and that the vibrator is small (10 × 2.5 × 2 mm: W×H×D), owing to the simple construction of the inner electrodes. Additionally, the present study revealed that an ultrasonic linear motor using the multilayer L1-F2 mode vibrator exhibits superior performance in practical application.

  20. 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.

  1. Analysis of Rayleigh-Lamb Modes in Soft-solids with Application to Surface Wave Elastography

    NASA Astrophysics Data System (ADS)

    Benech, Nicolás; Grinspan, Gustavo; Aguiar, Sofía; Brum, Javier; Negreira, Carlos; tanter, Mickäel; Gennisson, Jean-Luc

    The goal of Surface Wave Elastography (SE) techniques is to estimate the shear elasticity of the sample by measuring the surface wave speed. In SE the thickness of the sample is often assumed to be infinite, in this way, the surface wave speed is directly linked to the sample's shear elasticity. However for many applications this assumption is not true. In this work, we study experimentally the Rayleigh-Lamb modes in soft solids of finite thickness to explore the optimal conditions for SWE. Experiments were carried out in three tissue mimicking phantoms of different thicknesses (10 mm, 20 mm and 60 mm) and same shear elasticity. The surface waves were generated at the surface of the phantom using piston attached to a mechanical vibrator. The central frequency of the excitation was varied between 60 Hz to 160 Hz. One component of the displacement field generated by the piston was measured at the surface and in the bulk of the sample trough a standard speckle tracking technique using a 256 element, 7.5 MHz central frequency linear array and an ultrasound ultrafast electronics. Finally, by measuring the phase velocity at each excitation frequency, velocity dispersion curves were obtained for each phantom. The results show that instead of a Rayleigh wave, zero order symmetric (S0) and antisymmetric (A0) Lamb modes are excited with this type of source. Moreover, in this study we show that due to the near field effects of the source, which are appreciable only in soft solids at low frequencies, both Lamb modes are separable in time and space. We show that while the Ao mode dominates close the source, the S0 mode dominates far away.

  2. Derivation of continuous wave mode output power from burst mode measurements in high-intensity ultrasound applications.

    PubMed

    Haller, Julian; Wilkens, Volker

    2014-03-01

    Measurement of the acoustic output power of transducers in burst mode and derivation of the results to the continuous wave (CW) case reduces heating problems during power measurements with radiation force balances and absorbing targets at high power levels, but requires the knowledge of an "effective duty factor," DReff. In this work, an alternative method for determining DReff is presented that allows the determination at any input voltage amplitude as it can be calculated from the input voltage rf signal in burst mode. Thus with this method, it is not necessary to apply CW signals at all.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. Application of the Empirical Mode Decomposition to Seismic Reflection and Ground Penetrating Radar Data

    NASA Astrophysics Data System (ADS)

    Battista, B. M.; Addison, A.; Knapp, C.; McGee, T.

    2006-12-01

    Advancements in signal processing may allow for improved imaging and analysis of complex geologic targets found in seismic reflection and ground penetrating radar data (GPR). A recent contribution to signal processing is the Empirical Mode Decomposition (EMD). The EMD empirically reduces a time series to several sub- signals whose sum yield the original time series. The benefit of such a process is to empirically develop signal-dependent, time-variant filters in the time domain. The objective of this work is to determine whether the EMD allows for empirically derived characteristics to be used in filter design and application, resulting in better filter performance and enhanced signal-to-noise ratio. Two data sets are used to show successful application of the EMD to geophysical data. Nonlinear cable strum is removed from one data set while the other is used to remove WOW noise from GPR data. Comparison to traditional techniques demonstrates the effectiveness of the technique.

  9. Mode Theory of Multi-Armed Spiral Antennas and Its Application to Electronic Warfare Antennas

    NASA Astrophysics Data System (ADS)

    Radway, Matthew J.

    Since their invention about 55 years ago, spiral antennas have earned a reputation for providing stable impedance and far-field patterns over multi-decade frequency ranges. For the first few decades these antennas were researched for electronic warfare receiving applications, primarily in the 2-18 GHz range. This research was often done under conditions of secrecy, and often by private contractors who did not readily share their research, and now have been defunct for decades. Even so, the body of literature on the two-armed variant of these antennas is rich, often leading non-specialists to the misconception that these antennas are completely understood. Furthermore, early work was highly experimental in nature, and was conducted before modern data collection and postprocessing capabilities were widespread, which limited the range of the studies. Recent research efforts have focused on extending the application of spirals into new areas, as well as applying exotic materials to `improve' their performance and reduce their size. While interesting results have been obtained, in most instances these were incomplete, often compromising the frequency independent nature of these antennas. This thesis expands the role of the multi-armed spiral outside of its traditional niche of receive-only monopulse direction finding. As a first step, careful study of the spiral-antenna mode theory is undertaken with particular attention paid to the concepts of mode filtering and modal decomposition. A technique for reducing the modal impedance of high arm-count spirals is introduced. The insights gained through this theoretical study are first used to improve the far-field performance of the coiled-arm spiral antenna. Specifically, expanding the number of arms on a coiled arm spiral from two to four while providing proper excitation enables dramatically improved broadside axial ratio and azimuthal pattern uniformity. The multiarming technique is then applied to the design of an antenna

  10. 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

    ... new CDC or for an existing CDC to expand Area of Operations. 120.837 Section 120.837 Business Credit...) Extending A Cdc's Area of Operations § 120.837 SBA decision on application for a new CDC or for an existing CDC to expand Area of Operations. The processing District Office must solicit the comments of...

  11. 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, 2014 CFR

    2014-01-01

    ... new CDC or for an existing CDC to expand Area of Operations. 120.837 Section 120.837 Business Credit...) Extending A Cdc's Area of Operations § 120.837 SBA decision on application for a new CDC or for an existing CDC to expand Area of Operations. The processing District Office must solicit the comments of...

  12. 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, 2011 CFR

    2011-01-01

    ... new CDC or for an existing CDC to expand Area of Operations. 120.837 Section 120.837 Business Credit...) Extending A Cdc's Area of Operations § 120.837 SBA decision on application for a new CDC or for an existing CDC to expand Area of Operations. The processing District Office must solicit the comments of...

  13. 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, 2013 CFR

    2013-01-01

    ... new CDC or for an existing CDC to expand Area of Operations. 120.837 Section 120.837 Business Credit...) Extending A Cdc's Area of Operations § 120.837 SBA decision on application for a new CDC or for an existing CDC to expand Area of Operations. The processing District Office must solicit the comments of...

  14. 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, 2012 CFR

    2012-01-01

    ... new CDC or for an existing CDC to expand Area of Operations. 120.837 Section 120.837 Business Credit...) Extending A Cdc's Area of Operations § 120.837 SBA decision on application for a new CDC or for an existing CDC to expand Area of Operations. The processing District Office must solicit the comments of...

  15. Superconducting Gravimeter Data for the IRIS Seismology Database: Application to Normal Modes from the Sumatra Earthquake

    NASA Astrophysics Data System (ADS)

    Crossley, D.; Rivera, L.; Hinderer, J.; Rosat, S.

    2009-04-01

    For several years, it has been the goal of the Global Geodynamics Project (GGP) to convert high rate acceleration data recorded on superconducting gravimeters (SG) to a format compatible with the seismic data archived at IRIS. The problem for the GGP community has been to properly establish the metadata for characterizing the response of the instrument, particularly its phase characteristics. Although SG data exists at IRIS from the Membach GGP station in Belgium, up to now most of the data from the GGP network has been on hold until the response problem was solved. This we have now been able to do, and we hope to show that data from the Strasbourg SG station will be at IRIS and available. We will also upload all the data from the SGs from after the Sumatra earthquake and show some results on normal mode analysis that demonstrates the benefit of the good amplitude calibration feature and high precision of the SG instruments.

  16. 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.

  17. 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.

  18. 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.

  19. 45 CFR 260.74 - How do existing welfare reform waivers affect the application of the Federal time-limit provisions?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... application of the Federal time-limit provisions? 260.74 Section 260.74 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND....74 How do existing welfare reform waivers affect the application of the Federal time-limit...

  20. 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

    ...: Reinforced Plastic Composites Production Calculating Organic Hap Emissions Factors for Open Molding and... 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...

  1. 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 the...

  2. 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

    2013-09-06

    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.

  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. 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.

  5. 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.

  6. 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.

  7. 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. RSNA, 2010

  8. Multivariate empirical mode decomposition and its application to fault diagnosis of rolling bearing

    NASA Astrophysics Data System (ADS)

    Lv, Yong; Yuan, Rui; Song, Gangbing

    2016-12-01

    Rolling bearings are widely used in rotary machinery systems. The measured vibration signal of any part linked to rolling bearings contains fault information when failure occurs, differing only by energy levels. Bearing failure will cause the vibration of other components, and therefore the collected bearing vibration signals are mixed with vibration signal of other parts and noise. Using multiple sensors to collect signals at different locations on the machine to obtain multivariate signal can avoid the loss of local information. Subsequently using the multivariate empirical mode decomposition (multivariate EMD) to simultaneously analyze the multivariate signal is beneficial to extract fault information, especially for weak fault characteristics during the period of early failure. This paper proposes a novel method for fault feature extraction of rolling bearing based on multivariate EMD. The nonlocal means (NL-means) denoising method is used to preprocess the multivariate signal and the correlation analysis is employed to calculate fault correlation factors to select effective intrinsic mode functions (IMFs). Finally characteristic frequencies are extracted from the selected IMFs by spectrum analysis. The numerical simulations and applications to bearing monitoring verify the effectiveness of the proposed method and indicate that this novel method is promising in the field of signal decomposition and fault diagnosis.

  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. A Characterization of the Existence of Solutions for Hamilton-Jacobi Equations in Ergodic Control Problems with Applications

    SciTech Connect

    Arisawa, M.; Ishii, H.; Lions, P.-L.

    2000-07-01

    We give a characterization of the existence of bounded solutions for Hamilton-Jacobi equations in ergodic control problems with state-constraint. This result is applied to the reexamination of the counterexample concerning the existence of solutions for ergodic control problems in infinite-dimensional Hilbert spaces and also establishing results on effective Hamiltonians in periodic homogenization of Hamilton-Jacobi equations.

  11. Second-order integral sliding-mode control with experimental application.

    PubMed

    Furat, Murat; Eker, İlyas

    2014-09-01

    In the present study, a second-order sliding-mode controller is proposed for single-input single-output (SISO) uncertain real systems. The proposed controller successively overcomes the variations caused by the uncertainties and external load disturbances although an approximate model of the system is used in the design procedure. An integral type sliding surface is used and the stability and robustness properties of the proposed controller are proved by means of Lyapunov stability theorem. The chattering phenomenon is significantly reduced adopting the switching gain with the known parameters of the system. Thus, the proposed controller is suitable for long-term application to the real systems. The performance of the proposed control scheme is validated by a real system experiments and the results are compared with the similar controllers presented in the literature.

  12. 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.

  13. High-power high-speed single-mode diode lasers for optical intersatellite link applications

    NASA Astrophysics Data System (ADS)

    Li, Benjamin; Sha, WeiJian; Yeh, PingHui S.; Nagarajan, Radhakrishnan; Craig, Richard R.

    1998-05-01

    High power single-mode AlGaAs semiconductor lasers operating between 820 nm and 860 nm (SDL-5400 series diodes) have been successfully qualified for deployment in many free-space inter-satellite communication link programs. Traditionally these high power devices did not have sufficient bandwidth for direct high speed modulation because of large device and package parasitics. We have improved the device parasitics of the SDL-5430 laser diode, i.e. reduced the RC product, from 240 ps to about 40 ps. The initial measurements indicate that this device (SDL-5480) is suitable for high power optical inter-satellite link (OISL) applications at data rates greater than 1 Gbit/s. The preliminary life test indicates that the new device has better a reliability than the previous design.

  14. Application of nonlinear sliding mode control to ultrasound contrast agent microbubbles.

    PubMed

    Carroll, James M; Lauderbaugh, Leal K; Calvisi, Michael L

    2013-07-01

    A sliding mode control system is developed and applied to a spherical model of a contrast agent microbubble that simulates its radial response to ultrasound. The model uses a compressible form of the Rayleigh-Plesset equation combined with a thin-shell model. A nonlinear control law for the second-order model is derived and used to design and simulate the controller. The effect of the controller on the contrast agent response is investigated for various control scenarios. This work demonstrates the feasibility of using a nonlinear control system to modulate the dynamic response of ultrasound contrast agents, but highlights the need for improved feedback mechanisms and control input methods. Possible applications of the nonlinear control system to contrast agents illustrated in this work include radius stabilization in the presence of an acoustic wave, radial growth and subsequent collapse, and generation of periodic radial oscillations while a contrast agent is within an acoustic forcing regime known to cause a chaotic response.

  15. Application of the Method for Object-based Evaluation (MODE) for Evaluation of High- resolution Precipitation Forecasts

    NASA Astrophysics Data System (ADS)

    Brown, B. G.; Sullivan, S.; Halley Gotway, J.; Bullock, R.

    2008-12-01

    In recent years, the verification and weather forecasting communities have invested a great deal of effort toward the development of new diagnostic approaches for evaluating spatial forecasts of precipitation. These methods are needed in order to provide more informative evaluations of forecast performance than can be obtained from traditional metrics such as the Critical Success Index or Mean-Squared Error. The Method for Object-based Evaluation (MODE) is one of the new approaches, and can be categorized as a "features-based" approach. MODE identifies and compares attributes of precipitation objects that are relevant for particular applications; object attributes can include such features as storm location, size, and intensity, as well as other aspects of forecast and observed precipitation areas that are relevant for a particular application. During the summer of 2008, MODE and other verification approaches were applied to precipitation forecasts from several high-resolution numerical weather prediction models that were included in the "Spring Experiment" sponsored by the NOAA Storm Prediction Center. MODE provided evaluations and comparisons of the heavy precipitation events that were of interest for this project. One of the goals of the 2008 project was to determine what information could be obtained from the MODE and other evaluations that would be relevant for forecasters and other users of the model forecasts. Results from the application of MODE and the other verification methods will be compared and summarized to provide guidance for methods to be used in future evaluations of high-resolution forecast models.

  16. Dosimetric properties of an amorphous-silicon EPID used in continuous acquisition mode for application to dynamic and arc IMRT

    SciTech Connect

    McCurdy, B. M. C.; Greer, P. B.

    2009-07-15

    -IMRT tests revealed that all examples compared to within 2% of maximum dose for more than 95% of in-field pixels. The continuous acquisition mode is suited to time-resolved dosimetry applications including arc-IMRT and dynamic IMRT, giving comparable dose results to the well-studied integrated acquisition mode, although caution should be used in low MU applications. Time-resolved EPID dose information also compared well to time-resolved ion-chamber measurements.

  17. Mode-specific tunneling using the Qim path: theory and an application to full-dimensional malonaldehyde.

    PubMed

    Wang, Yimin; Bowman, Joel M

    2013-10-21

    We present a theory of mode-specific tunneling that makes use of the general tunneling path along the imaginary-frequency normal mode of the saddle point, Qim, and the associated relaxed potential, V(Qim) [Y. Wang and J. M. Bowman, J. Chem. Phys. 129, 121103 (2008)]. The novel aspect of the theory is the projection of the normal modes of a minimum onto the Qim path and the determination of turning points on V(Qim). From that projection, the change in tunneling upon mode excitation can be calculated. If the projection is zero, no enhancement of tunneling is predicted. In that case vibrationally adiabatic (VA) theory could apply. However, if the projection is large then VA theory is not applicable. The approach is applied to mode-specific tunneling in full-dimensional malonaldehyde, using an accurate full-dimensional potential energy surface. Results are in semi-quantitative agreement with experiment for modes that show large enhancement of the tunneling, relative to the ground state tunneling splitting. For the six out-of-plane modes, which have zero projection on the planar Qim path, VA theory does apply, and results from that theory agree qualitatively and even semi-quantitatively with experiment. We also verify the failure of simple VA theory for modes that show large enhancement of tunneling.

  18. Slave Mode Expansion for Obtaining Ab Initio Interatomic Potentials and its Applications

    NASA Astrophysics Data System (ADS)

    Ai, Xinyuan

    Having an interatomic potential overcomes limitations within DFT since it has a negligible cost in computing material properties while DFT is severely restricted by its computational cost when carrying out such tasks. In this thesis, we propose a new approach for creating an interatomic potential based on the Taylor series expansion of the crystal energy as a function of its nuclear displacements. We enlarge the dimensionality of the existing displacement space and form new variables (ie. slave modes) which transform like irreducible representations of the point group and satisfy homogeneity of free space. Standard group theoretical techniques can then be applied to deduce the non-zero expansion coefficients a priori. At a given order, the translation group can be used to contract the products and eliminate terms which are not linearly independent, resulting in a final set of slave mode products. By the end of the day, one ends up with an expansion that satisfies lattice symmetry and its number of coefficients is much smaller than that of a common Taylor series expansion. While the expansion coefficients can be computed in a variety of ways, we demonstrate that finite difference is effective up to fifth order. On the other hand, we demonstrate the power of the method in the strongly anharmonic systems PbTe and graphene. All anharmonic terms within an octahedron are computed up to fourth order for PbTe, while those within a hexagon are computed up to fourth order and dimer terms are computed at fifth order for graphene. In addition, for PbTe, a proper unitary transformation of its potential demonstrates that the vast majority of the anharmonicity can be attributed to just two terms, indicating that a minimal model of phonon interactions is achievable. The ability to straightforwardly generate polynomial potentials will allow precise simulations at length and time scales which were previously unrealizable.

  19. FUNDAMENTAL AREAS OF PHENOMENOLOGY (INCLUDING APPLICATIONS): High Polarization Single Mode Photonic Crystal Microlaser

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Xing, Ming-Xin; Zhou, Wen-Jun; Liu, An-Jin; Zheng, Wan-Hua

    2009-08-01

    Generally, dipole mode is a doubly degenerate mode. Theoretical calculations have indicated that the single dipole mode of two-dimensional photonic crystal single point defect cavity shows high polarization property. We present a structure with elongated lattice, which only supports a single y-dipole mode. With this structure we can eliminate the degeneracy, control the lasing action of the cavity and demonstrate the high polarization property of the single dipole mode. In our experiment, the polarization extinction ratio of the y-dipole mode is as high as 51:1.

  20. 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.

  1. 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

  2. Finding Services for an Open Architecture: A Review of Existing Applications and Programs in PEO C4I

    DTIC Science & Technology

    2011-01-01

    2004) Two key SOA success factors listed were as follows: 1. Shared Services Strategy: Existence of a strategy to identify overlapping business and...model Architectural pattern 22 Finding Services for an Open Architecture or eliminating redundancies and overlaps through use of shared services 2...Funding Model: Existence of an IT funding model aligned with and supportive of a shared services strategy. (Sun Micro- systems, 2004) Become Data

  3. 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.

  4. Investigation of fault modes in permanent magnet synchronous machines for traction applications

    NASA Astrophysics Data System (ADS)

    Choi, Gilsu

    Over the past few decades, electric motor drives have been more widely adopted to power the transportation sector to reduce our dependence on foreign oil and carbon emissions. Permanent magnet synchronous machines (PMSMs) are popular in many applications in the aerospace and automotive industries that require high power density and high efficiency. However, the presence of magnets that cannot be turned off in the event of a fault has always been an issue that hinders adoption of PMSMs in these demanding applications. This work investigates the design and analysis of PMSMs for automotive traction applications with particular emphasis on fault-mode operation caused by faults appearing at the terminals of the machine. New models and analytical techniques are introduced for evaluating the steady-state and dynamic response of PMSM drives to various fault conditions. Attention is focused on modeling the PMSM drive including nonlinear magnetic behavior under several different fault conditions, evaluating the risks of irreversible demagnetization caused by the large fault currents, as well as developing fault mitigation techniques in terms of both the fault currents and demagnetization risks. Of the major classes of machine terminal faults that can occur in PMSMs, short-circuit (SC) faults produce much more dangerous fault currents than open-circuit faults. The impact of different PMSM topologies and parameters on their responses to symmetrical and asymmetrical short-circuit (SSC & ASC) faults has been investigated. A detailed investigation on both the SSC and ASC faults is presented including both closed-form and numerical analysis. The demagnetization characteristics caused by high fault-mode stator currents (i.e., armature reaction) for different types of PMSMs are investigated. A thorough analysis and comparison of the relative demagnetization vulnerability for different types of PMSMs is presented. This analysis includes design guidelines and recommendations for

  5. 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.

  6. 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

  7. Surgical hand disinfection using alcohol: the effects of alcohol type, mode and duration of application.

    PubMed

    Suchomel, M; Gnant, G; Weinlich, M; Rotter, M

    2009-03-01

    Due to their strong antimicrobial activity, rapid action, good dermal tolerance and ease of application, alcohol-based hand rubs are recommended for pre-operative preparation of the surgical team's hands. Using the EN 12791 protocol, three commercial products containing either mixtures of propan-1-ol and propan-2-ol or ethanol at total alcohol concentrations (w/w) between 73% (propanols) and 78.2% (ethanol), as the main active agents, were tested with a shortened application of 1.5 min rather than the usual 3 min. Preparation A containing 30% propan-1-ol and 45% propan-2-ol not only passed the test at this short application but even exceeded, though not significantly, the efficacy of the reference disinfection procedure in EN 12791 when applied for 3 min. Preparation B containing 45% propan-1-ol and 28% propan-2-ol fulfilled the required standard whereas the ethanol (78.2%)-based product C did not (P<0.1). This demonstrates that some, but not all, alcohol-based hand rubs pass the test even within 1.5 min, emphasising the importance of validation before a product is introduced into clinical practice. In another series with both preparation A and 60% v/v propan-1-ol, it was demonstrated that the additional inclusion of the forearms into the disinfection procedure, not required by EN 12791 but normal practice in surgical hand disinfection, does not significantly interfere with the antimicrobial efficacy of either hand rub. Therefore, the mode of test procedure in EN 12791 does not need specific adaptation for hand disinfection by surgical teams.

  8. 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

  9. Environmental Assessment for Improvements to Irrigation System and Land Application of Treated Wastewater Effluent at Existing Golf Course, Mountain Home AFB, Idaho

    DTIC Science & Technology

    2003-08-01

    Final Environmental Assessment for Improvements to Irrigation System and Land Application of Treated Wastewater Effluent at...Land Application of Treated Wastewater Effluent at Existing Golf Course, Mountain Home AFB, Idaho 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM... SBR Sequencing Batch Reactor FONSI Finding of No Significant Impact SDR Scheduled Dimension Ratio Ft/Sec Feet Per Second SIP State Implementation

  10. 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.

  11. 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.

  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. 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?…

  15. 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'…

  16. 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

  17. 45 CFR 260.74 - How do existing welfare reform waivers affect the application of the Federal time-limit provisions?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 2 2013-10-01 2012-10-01 true How do existing welfare reform waivers affect the application of the Federal time-limit provisions? 260.74 Section 260.74 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND...

  18. 45 CFR 260.74 - How do existing welfare reform waivers affect the application of the Federal time-limit provisions?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 2 2014-10-01 2012-10-01 true How do existing welfare reform waivers affect the application of the Federal time-limit provisions? 260.74 Section 260.74 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND...

  19. 45 CFR 260.74 - How do existing welfare reform waivers affect the application of the Federal time-limit provisions?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 2 2012-10-01 2012-10-01 false How do existing welfare reform waivers affect the application of the Federal time-limit provisions? 260.74 Section 260.74 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND...

  20. 45 CFR 260.74 - How do existing welfare reform waivers affect the application of the Federal time-limit provisions?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 2 2011-10-01 2011-10-01 false How do existing welfare reform waivers affect the application of the Federal time-limit provisions? 260.74 Section 260.74 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND...

  1. 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.

  2. Frequency stabilization, tuning, and spatial mode control of terahertz quantum cascade lasers for coherent transceiver applications

    NASA Astrophysics Data System (ADS)

    Danylov, Andriy

    THz quantum cascade lasers (TQCLs) first demonstrated in 2002 are a promising source of THz coherent radiation for use as both transmitters and local oscillators in coherent heterodyne detection systems. However, present TQCLs have deficiencies which include lack of frequency tunability, as well as inadequate spatial and temporal coherence. In this thesis we have addressed these issues to demonstrate an improved 2.408 TQCL which operated as a transmitter in a coherent heterodyne detection imaging system. The 2.408 THz QCL used in this thesis was grown and fabricated by the Photonics Center (University of Massachusetts Lowell). First, we showed that a short hollow Pyrex tube can act as a dielectric waveguide and transform the multimode, highly diverging TQCL beam into the lowest order dielectric waveguide hybrid mode, EH11, which then couples efficiently to the free-space Gaussian mode, TEMo0. This simple approach should enable TQCLs to be employed in applications where a spatially coherent beam is required. Next, the tunability problem was addressed. A compact, tunable, narrowband terahertz source was demonstrated by mixing a single longitudinal mode, 2.408 THz, free running quantum cascade laser with a 2-20 GHz microwave sweeper in a corner-cube-mounted Schottky diode (SD). The sideband spectra were characterized with a Fourier transform spectrometer, and the radiation was tuned through several D2O rotational transitions to estimate the longer term (t ≥ several seconds) bandwidth of the source. A spectral resolution of 2 MHz in the CW mode was observed. The temporal coherence of the TQCL was improved by assembling a simple analog locking circuit, which stabilizes the beat signal between the TQCL and a 2.40976 THz CO2 optically pumped molecular laser (OPL) line to 4 kHz full width at half maximum (FWHM). This is approximately a tenth of the observed long-term (t ˜ sec) linewidth of the OPL showing that the feedback loop corrects for much of the mechanical and

  3. 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

  4. 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

  5. In vivo histological evaluation of non-insulated microneedle radiofrequency applicator with novel fractionated pulse mode.

    PubMed

    Harth, Yoram; Frank, Ido

    2013-12-01

    Microneedle radiofrequency is a novel method that allows non-thermal penetration of the epidermis followed by RF coagulation in selected depth of the dermis surrounded by zone of non-coagulative volumetric heating. The first generation of Microneedle RF applicators used insulated needles. These treatments were limited by a few factors, including low volume of dermal heating, lack of effect in the papillary dermis and pinpoint bleeding during the treatment. The system tested in this study (EndyMed PRO, Intensif applicator, EndyMed Medical, Cesarea, Israel) utilizes special extra sharp tapered non-insulated microneedles and a special pulse mode, allowing full coagulation during treatment and higher effective volume of dermal heat. After Ethics Committee approval, one female pig (Type Large white X Landrace, 34 Kg) was chosen for the study. The animal was anesthetized using Ketamine, Xylazin and Isofluran. The EndyMed PRO, Intensif applicator (was used for treatment with different needle depth penetration (1 mm-3.5 mm) and in multiple energy settings. Six mm punch biopsies were harvested for histological analysis at the following time points: immediately after the treatment, 4 days after the treatment and 14 days after the treatment. H&E and Masson-Trichrome stains were processed. Visual inspection of the treated skin, immediately after the treatment, revealed arrays of pinpoint erythematous papules surrounded by undamaged epidermal tissue. Treatment field showed no sign of bleeding. Mild to moderate Erythema and Edema developed a few minutes after the treatment, varying according to the total energy delivered. The histologies taken 4-day after therapy showed in all energy settings, dry micro crusts over the treatment zones, with full healing of epidermis. In the 14-day specimens there was a replacement of the crusts/debris by a normal looking stratum corneum with complete healing of epidermis and dermis. The current in vivo study confirms that the EndyMed PRO

  6. A 2013 Survey on Pressure Monitoring in Adult Cardiopulmonary Bypass Circuits: Modes and Applications.

    PubMed

    Rigg, Laura; Searles, Bruce; Darling, Edward Morse

    2014-12-01

    Pressure data acquired from multiple sites of extracorporeal circuits can be an important parameter to monitor for the safe conduct of cardiopulmonary bypass (CPB). Although previous surveys demonstrate that CPB circuit pressure monitoring is widely used, there are very little data cataloging specific applications of this practice. Therefore, the purpose of this study is to survey the perfusion community to catalog 1) primary CPB circuit site pressure monitoring locations; 2) type of manometers used; 3) pressure monitoring interface and servoregulation with pump console; and 4) the rationale and documentation associated with pressure monitoring during CPB. In June 2013, a validated 27-question online survey was sent directly through an e-mail link to the chief perfusionists in the northeast United States. Completed surveys were received from 75 of 117 surveys deployed yielding a 64% response rate. Arterial line pressure monitoring during CPB is reported by 99% with six distinct circuit site locations identified. Cardioplegia system pressure was monitored by 95% of the centers. For vacuum-assisted venous drainage (VAVD) users, the venous pressure was measured by 72% of the responding centers. Arterial line pressure servoregulation of the arterial pump was indicated by 61% of respondents and 75% of centers record arterial line pressure in their perfusion record. Most centers (77%) report the use of a transducer that is integrated into the pump console providing a digital pressure display, whereas 20% combine an aneroid gauge manometer with the integrated digital transducer. This study demonstrates that the practice of arterial line pressure monitoring during CPB is nearly universal. However, the selection of the pressure monitoring site on the circuit, modes of monitoring pressure, and their applications are highly variable across the perfusion community.

  7. 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.

  8. A 2013 Survey on Pressure Monitoring in Adult Cardiopulmonary Bypass Circuits: Modes and Applications

    PubMed Central

    Rigg, Laura; Searles, Bruce; Darling, Edward Morse

    2014-01-01

    Abstract: Pressure data acquired from multiple sites of extracorporeal circuits can be an important parameter to monitor for the safe conduct of cardiopulmonary bypass (CPB). Although previous surveys demonstrate that CPB circuit pressure monitoring is widely used, there are very little data cataloging specific applications of this practice. Therefore, the purpose of this study is to survey the perfusion community to catalog 1) primary CPB circuit site pressure monitoring locations; 2) type of manometers used; 3) pressure monitoring interface and servoregulation with pump console; and 4) the rationale and documentation associated with pressure monitoring during CPB. In June 2013, a validated 27-question online survey was sent directly through an e-mail link to the chief perfusionists in the northeast United States. Completed surveys were received from 75 of 117 surveys deployed yielding a 64% response rate. Arterial line pressure monitoring during CPB is reported by 99% with six distinct circuit site locations identified. Cardioplegia system pressure was monitored by 95% of the centers. For vacuum-assisted venous drainage (VAVD) users, the venous pressure was measured by 72% of the responding centers. Arterial line pressure servoregulation of the arterial pump was indicated by 61% of respondents and 75% of centers record arterial line pressure in their perfusion record. Most centers (77%) report the use of a transducer that is integrated into the pump console providing a digital pressure display, whereas 20% combine an aneroid gauge manometer with the integrated digital transducer. This study demonstrates that the practice of arterial line pressure monitoring during CPB is nearly universal. However, the selection of the pressure monitoring site on the circuit, modes of monitoring pressure, and their applications are highly variable across the perfusion community. PMID:26357797

  9. 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.

  10. 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.

  11. Partial differential equation-based approach for empirical mode decomposition: application on image analysis.

    PubMed

    Niang, Oumar; Thioune, Abdoulaye; El Gueirea, Mouhamed Cheikh; Deléchelle, Eric; Lemoine, Jacques

    2012-09-01

    The major problem with the empirical mode decomposition (EMD) algorithm is its lack of a theoretical framework. So, it is difficult to characterize and evaluate this approach. In this paper, we propose, in the 2-D case, the use of an alternative implementation to the algorithmic definition of the so-called "sifting process" used in the original Huang's EMD method. This approach, especially based on partial differential equations (PDEs), was presented by Niang in previous works, in 2005 and 2007, and relies on a nonlinear diffusion-based filtering process to solve the mean envelope estimation problem. In the 1-D case, the efficiency of the PDE-based method, compared to the original EMD algorithmic version, was also illustrated in a recent paper. Recently, several 2-D extensions of the EMD method have been proposed. Despite some effort, 2-D versions for EMD appear poorly performing and are very time consuming. So in this paper, an extension to the 2-D space of the PDE-based approach is extensively described. This approach has been applied in cases of both signal and image decomposition. The obtained results confirm the usefulness of the new PDE-based sifting process for the decomposition of various kinds of data. Some results have been provided in the case of image decomposition. The effectiveness of the approach encourages its use in a number of signal and image applications such as denoising, detrending, or texture analysis.

  12. Superconducting antennas for telecommunication applications based on dual mode cross slotted patches

    NASA Astrophysics Data System (ADS)

    Cassinese, A.; Barra, M.; Fragalà, I.; Kusunoki, M.; Malandrino, G.; Nakagawa, T.; Perdicaro, L. M. S.; Sato, K.; Ohshima, S.; Vaglio, R.

    2002-08-01

    Dual mode devices based on high temperature superconducting films represent an interesting class for telecommunication applications since they combine a miniaturized size with a good power handling. Here we report on a novel compact antenna obtained by crossing a square patch with two or more slots. The proposed design has an antenna size reduction of about 40% as compared to the conventional square patch microstrip antennas. Single patch antenna both with linear (LP) and circular (CP) polarization operating in the X-band have been designed and tested at prototype level. They are realized by using double sided (YBa 2Cu 3O 7- x) YBCO and Tl 2Ba 2Ca 1Cu 2O 8 (Tl-2212) superconducting films grown on MgO substrates and tested with a portable cryocooler. They showed at T=77 K a return loss <25 dB and a power handling of 23 dBm. Exemplary 16 elements arrays LP antennas operating in the X band have been also realized by using YBCO film grown on 2 ″ diameter MgO substrate.

  13. Optical signal processing and tracking of whispering gallery modes in real-time for sensing applications

    NASA Astrophysics Data System (ADS)

    Ali, Amir R.; Afifi, Amr N.; Taha, Hazem

    2017-05-01

    A novel approach for tracking of whispering gallery modes (WGM) in real-time for dielectric cavities used in sensing application is presented in this paper. Real-time tracking for the shifts of the WGM can be used to measure the physical quantity of interest precisely, under high repetition rates. The tracking algorithm is based on cross-correlation signal processing technique which has been proved to be accurate in WGM shifts detection. In order to achieve portability, the aforementioned real-time algorithm is implemented using a single-board re-configurable input-output hardware. The hardware platform used combines a real-time processor and a field programmable gate array (FPGA), it also allows for data exchange between them. The tracking algorithm's accuracy and real-time behavior is verified by preforming simulations based on experiments conducted on the dielectric cavity, where the cavity is used as a force sensor measuring mechanical compression. The light from a laser diode is tuned with rates up to 10 kHz and then tangentially coupled into the cavity to excite the WGM. Results show that shifts of the WGM are tracked by the algorithm providing real-time force readings.

  14. A Novel Current-Mode Differential Transconductance LNA for IEEE 802.11a Application

    NASA Astrophysics Data System (ADS)

    Tu, Yuxiang; Wang, Chunhua; Chen, Lei; Wu, Zhangbin; Zhang, Guangxiang

    2012-03-01

    In this paper, a novel current-mode differential transconductance low noise amplifier (LNA) designed in the chartered 0.18 μm CMOS technology is proposed to realize the receiver front-end. The proposed LNA frequency ranges from 4.7 GHz to 6 GHz,mainly targeting at IEEE802.11a application. It utilizes two stage structure, with a PMOS current-mirrorr using inductive series peaking technique to achieve optimized current output. The noise performance is improved through the use of a gm-boosting technique, while the gain performance is improved and power consumption is saved by using current-reused technique. Measured results demonstrate that the circuit provides flat transconductance gain higher than 17.0 dB, noise figure lower than 2.31 dB and low operating voltage of 0.85 V in frequency band. A comparison with other LNAs in similar and nearby frequency bands shows the proposed LNA has advantages of higher gain, lower noise figure and better other performances.

  15. Guided-mode resonance sensors for rapid medical diagnostic testing applications

    NASA Astrophysics Data System (ADS)

    Wawro, D.; Ding, Y.; Gimlin, S.; Zimmerman, S.; Kearney, C.; Pawlowski, K.; Magnusson, R.

    2009-02-01

    A new tag-free photonic resonance concept occurring on subwavelength waveguide gratings is applied for rapid medical testing applications. These high-resolution sensors operate in real time while being sensitive to a wide variety of analytes, including microbials. This method does not require extensive processing steps, thus simplifying assay tests and enabling a rapid response (less than 30 minutes is possible). In this work, a sensor system that uses a single, fixed-wavelength source with a shaped input wavefront to auto-scan in angle has been developed. As binding events occur at the sensor surface, shifts in a resonance reflection peak (or a corresponding transmission minimum) are tracked as a function of incident angle. The amount of angular shift is correlated to the quantity of analyte in the test sample. Due to inherent polarization diversity, two narrow peaks shift their positions on the sensor surface when a bioreaction occurs, thereby providing cross-referenced data. The sensor system connects to portable interfaces for data acquisition and analysis by dedicated software codes. A portable guided-mode resonance sensor system prototype has been developed. Its performance for the detection of the microbial S. aureus in buffer and rat serum is presented in this paper.

  16. FORWARD MODELING OF STANDING KINK MODES IN CORONAL LOOPS. II. APPLICATIONS

    SciTech Connect

    Yuan, Ding; Doorsselaere, Tom Van

    2016-04-15

    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.

  17. Wave Mode Processing Algorithms, Product Validation and Assimilation Wave Retrievals and Applications

    NASA Astrophysics Data System (ADS)

    Collard, Fabrice; Johnsen, Harald; Lotfi, Aouf; Chapron, Bertrand

    2013-03-01

    The fourth SAR oceanography workshop, SEASAR 2012 , entitled "Advances in SAR Oceanography", was held in Tromsø, 18th to 22th June 2012. Among the topics highlighted at SEASAR 2012 were ”Wave mode processing algorithms, product validation and assimilation” and ”Wave retrievals and applications”. The last decade of SAR wave research has brought high level of consensus on the various approaches for deriving wave information from SAR images. The main new achievements have been within advance applications of SAR wave derived information such as;1) the investigation of extreme sea states in intense storms; 2) the study of individual exceptional wave states, such as freak (monster) waves; 3) the extension of numerical wave models in the general context of Earth System modelling, including the improved representation of wave-current interactions, air-sea fluxes, and second-order spectral quantities related to infra-gravity and microseism generation, and; 4) improved assimilation of wave data in NWP models. This paper presents a summary of achievements and way forward within these fields since the previous white paper of SeaSAR2003 (ESA SP-565, 2004).

  18. Constrained dynamics and extraction of normal modes from ab initio molecular dynamics: application to ammonia.

    PubMed

    Siddick, M M; Ackland, G J; Morrison, C A

    2006-08-14

    We present a methodology for extracting phonon data from ab initio Born-Oppenheimer molecular dynamics calculations of molecular crystals. Conventional ab initio phonon methods based on perturbations are difficult to apply to lattice modes because the perturbation energy is dominated by intramolecular modes. We use constrained molecular dynamics to eliminate the effect of bond bends and stretches and then show how trajectories can be used to isolate and define in particular, the eigenvalues and eigenvectors of modes irrespective of their symmetry or wave vector. This is done by k-point and frequency filtering and projection onto plane wave states. The method is applied to crystalline ammonia: the constrained molecular dynamics allows a significant speed-up without affecting structural or vibrational modes. All Gamma point lattice modes are isolated: the frequencies are in agreement with previous studies; however, the mode assignments are different.

  19. The Application of Failure Modes and Effects Analysis Methodology to Intrathecal Drug Delivery for Pain Management

    PubMed Central

    Patel, Teresa; Fisher, Stanley P.

    2016-01-01

    Objective This study aimed to utilize failure modes and effects analysis (FMEA) to transform clinical insights into a risk mitigation plan for intrathecal (IT) drug delivery in pain management. Methods The FMEA methodology, which has been used for quality improvement, was adapted to assess risks (i.e., failure modes) associated with IT therapy. Ten experienced pain physicians scored 37 failure modes in the following categories: patient selection for therapy initiation (efficacy and safety concerns), patient safety during IT therapy, and product selection for IT therapy. Participants assigned severity, probability, and detection scores for each failure mode, from which a risk priority number (RPN) was calculated. Failure modes with the highest RPNs (i.e., most problematic) were discussed, and strategies were proposed to mitigate risks. Results Strategic discussions focused on 17 failure modes with the most severe outcomes, the highest probabilities of occurrence, and the most challenging detection. The topic of the highest‐ranked failure mode (RPN = 144) was manufactured monotherapy versus compounded combination products. Addressing failure modes associated with appropriate patient and product selection was predicted to be clinically important for the success of IT therapy. Conclusions The methodology of FMEA offers a systematic approach to prioritizing risks in a complex environment such as IT therapy. Unmet needs and information gaps are highlighted through the process. Risk mitigation and strategic planning to prevent and manage critical failure modes can contribute to therapeutic success. PMID:27477689

  20. Multi-mode application of graphene quantum dots bonded silica stationary phase for high performance liquid chromatography.

    PubMed

    Wu, Qi; Sun, Yaming; Zhang, Xiaoli; Zhang, Xia; Dong, Shuqing; Qiu, Hongdeng; Wang, Litao; Zhao, Liang

    2017-04-07

    Graphene quantum dots (GQDs), which possess hydrophobic, hydrophilic, π-π stacking and hydrogen bonding properties, have great prospect in HPLC. In this study, a novel GQDs bonded silica stationary phase was prepared and applied in multiple separation modes including normal phase, reversed phase and hydrophilic chromatography mode. Alkaloids, nucleosides and nucleobases were chosen as test compounds to evaluate the separation performance of this column in hydrophilic chromatographic mode. The tested polar compounds achieved baseline separation and the resolutions reached 2.32, 4.62, 7.79, 1.68 for thymidine, uridine, adenosine, cytidine and guanosine. This new column showed satisfactory chromatographic performance for anilines, phenols and polycyclic aromatic hydrocarbons in normal and reversed phase mode. Five anilines were completely separated within 10min under the condition of mobile phase containing only 10% methanol. The effect of water content, buffer concentration and pH on chromatographic separation was further investigated, founding that this new stationary phase showed a complex retention mechanism of partitioning, adsorption and electrostatic interaction in hydrophilic chromatography mode, and the multiple retention interactions such as π-π stacking and π-π electron-donor-acceptor interaction played an important role during the separation process. This GQDs bonded column, which allows us to adjust appropriate chromatography mode according to the properties of analytes, has possibility in actual application after further research.

  1. Application of a national administrative case definition for the identification of pre-existing diabetes mellitus in pregnancy.

    PubMed

    Allen, V M; Dodds, L; Spencer, A; Cummings, E A; MacDonald, N; Kephart, G

    2012-06-01

    Accurate ascertainment of pregnant women with pre-existing diabetes allows for the comprehensive surveillance of maternal and neonatal outcomes associated with this chronic disease. To determine the accuracy of case definitions for pre-existing diabetes mellitus when applied to a pregnant population, a cohort of women who were pregnant in Nova Scotia, Canada, between 1991 and 2003 was obtained from a population-based provincial perinatal database, the Nova Scotia Atlee Perinatal Database (NSAPD). Person-level data from administrative databases using hospital discharge abstract data and outpatient physician services data were linked to this cohort. Various algorithms for defining diabetes mellitus from the administrative data, including the algorithm suggested by the National Diabetes Surveillance System (NDSS), were compared to a reference standard definition from the NSAPD. Validation of the NDSS case definition applied to this pregnant population demonstrated a sensitivity of 87% and a positive predictive value (PPV) of 66.4%. Use of ICD-9 and ICD-10 diagnostic codes among hospitalizations with diabetes mellitus in pregnancy showed important increases in sensitivity and PPV, especially for those pregnancies delivered in tertiary centres. In this population, pregnancy-related administrative data from the hospitalization database alone appear to be a more accurate data source for identifying pre-existing diabetes than applying the NDSS case definition, particularly when pregnant women are delivered in a tertiary hospital. Although the NDSS definition of diabetes performs reasonably well compared to a reference standard definition of diabetes, using this definition for evaluating maternal and perinatal outcomes associated with diabetes in pregnancy will result in a certain degree of misclassification and, therefore, biased estimates of outcomes.

  2. Assignment of Empirical Mode Decomposition Components and Its Application to Biomedical Signals.

    PubMed

    Schiecke, K; Schmidt, C; Piper, D; Putsche, P; Feucht, M; Witte, H; Leistritz, L

    2015-01-01

    Empirical mode decomposition (EMD) is a frequently used signal processing approach which adaptively decomposes a signal into a set of narrow-band components known as intrinsic mode functions (IMFs). For multi-trial, multivariate (multiple simultaneous recordings), and multi-subject analyses the number and signal properties of the IMFs can deviate from each other between trials, channels and subjects. A further processing of IMFs, e.g. a simple ensemble averaging, should determine which IMFs of one signal correspond to IMFs from another signal. When the signal properties have similar characteristics, the IMFs are assigned to each other. This problem is known as correspondence problem. From the mathematical point of view, in some cases the correspondence problem can be transformed into an assignment problem which can be solved e.g. by the Kuhn-Munkres algorithm (KMA) by which a minimal cost matching can be found. We use the KMA for solving classic assignment problems, i.e. the pairwise correspondence between two sets of IMFs of equal cardinalities, and for pairwise correspondences between two sets of IMFs with different cardinalities representing an unbalanced assignment problem which is a special case of the k-cardinality assignment problem. A KMA-based approach to solve the correspondence problem was tested by using simulated, heart rate variability (HRV), and EEG data. The KMA-based results of HRV decomposition are compared with those obtained from a hierarchical cluster analysis (state-of-the-art). The major difference between the two approaches is that there is a more consistent assignment pattern using KMA. Integrating KMA into complex analysis concepts enables a comprehensive exploitation of the key advantages of the EMD. This can be demonstrated by non-linear analysis of HRV-related IMFs and by an EMD-based cross-frequency coupling analysis of the EEG data. The successful application to HRV and EEG analysis demonstrates that our solutions can be used for

  3. 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.

  4. 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.

  5. New results on the existences of solutions of the Dirichlet problem with respect to the Schrödinger-prey operator and their applications.

    PubMed

    Chen, Xu; Zhang, Lei

    2017-01-01

    In this paper, by using the Beurling-Nevanlinna type inequality we obtain new results on the existence of solutions of the Dirichlet problem with respect to the Schrödinger-prey operator. Meanwhile, the local stability of the Schrödingerean equilibrium and endemic equilibrium of the model are also discussed. We specially analyze the existence and stability of the Schrödingerean Hopf bifurcation by using the center manifold theorem and bifurcation theory. As applications, theoretic analysis and numerical simulation show that the Schrödinger-prey system with latent period has a very rich dynamic characteristics.

  6. 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.

  7. Comparisons and applications of four independent numerical approaches for linear gyrokinetic drift modes

    NASA Astrophysics Data System (ADS)

    Xie, H. S.; Li, Y. Y.; Lu, Z. X.; Ou, W. K.; Li, B.

    2017-07-01

    To help reveal the complete picture of linear kinetic drift modes, four independent numerical approaches, based on the integral equation, Euler initial value simulation, Euler matrix eigenvalue solution, and Lagrangian particle simulation, respectively, are used to solve the linear gyrokinetic electrostatic drift mode equation in Z-pinch with slab simplification and in tokamak with a ballooning space coordinate. We identify that these approaches can yield the same solution with the difference smaller than 1%, and the discrepancies mainly come from the numerical convergence, which is the first detailed benchmark of four independent numerical approaches for gyrokinetic linear drift modes. Using these approaches, we find that the entropy mode and interchange mode are on the same branch in Z-pinch, and the entropy mode can have both electron and ion branches. And, at a strong gradient, more than one eigenstate of the ion temperature gradient mode (ITG) can be unstable and the most unstable one can be on non-ground eigenstates. The propagation of ITGs from ion to electron diamagnetic direction at strong gradient is also observed, which implies that the propagation direction is not a decisive criterion for the experimental diagnosis of turbulent mode at the edge plasmas.

  8. Imaging modes of atomic force microscopy for application in molecular and cell biology

    NASA Astrophysics Data System (ADS)

    Dufrêne, Yves F.; Ando, Toshio; Garcia, Ricardo; Alsteens, David; Martinez-Martin, David; Engel, Andreas; Gerber, Christoph; Müller, Daniel J.

    2017-04-01

    Atomic force microscopy (AFM) is a powerful, multifunctional imaging platform that allows biological samples, from single molecules to living cells, to be visualized and manipulated. Soon after the instrument was invented, it was recognized that in order to maximize the opportunities of AFM imaging in biology, various technological developments would be required to address certain limitations of the method. This has led to the creation of a range of new imaging modes, which continue to push the capabilities of the technique today. Here, we review the basic principles, advantages and limitations of the most common AFM bioimaging modes, including the popular contact and dynamic modes, as well as recently developed modes such as multiparametric, molecular recognition, multifrequency and high-speed imaging. For each of these modes, we discuss recent experiments that highlight their unique capabilities.

  9. Imaging modes of atomic force microscopy for application in molecular and cell biology.

    PubMed

    Dufrêne, Yves F; Ando, Toshio; Garcia, Ricardo; Alsteens, David; Martinez-Martin, David; Engel, Andreas; Gerber, Christoph; Müller, Daniel J

    2017-04-06

    Atomic force microscopy (AFM) is a powerful, multifunctional imaging platform that allows biological samples, from single molecules to living cells, to be visualized and manipulated. Soon after the instrument was invented, it was recognized that in order to maximize the opportunities of AFM imaging in biology, various technological developments would be required to address certain limitations of the method. This has led to the creation of a range of new imaging modes, which continue to push the capabilities of the technique today. Here, we review the basic principles, advantages and limitations of the most common AFM bioimaging modes, including the popular contact and dynamic modes, as well as recently developed modes such as multiparametric, molecular recognition, multifrequency and high-speed imaging. For each of these modes, we discuss recent experiments that highlight their unique capabilities.

  10. 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.

  11. 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.

  12. 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%).

  13. Application of divertor cryopumping to H-mode density control in DIII-D

    SciTech Connect

    Mahdavi, M.A.; Ferron, J.R.; Hyatt, A.W.

    1993-11-01

    In this paper we describe the method and the results of experiments where a unique in-vessel cryopump-baffle system was used to control density of H-mode plasmas. We were able to independently regulate current and density of ELMing H-mode plasmas, each over a range of factor two, and measure the H-mode confinement scaling with plasma density and current. With a modest pumping speed of {approx}40 kl/s, particle exhaust rates as high as 2 {times} 10{sup 22} atom/s{sup {minus}1} have been observed.

  14. Normal mode analysis as a prerequisite for drug design: application to matrix metalloproteinases inhibitors.

    PubMed

    Floquet, Nicolas; Marechal, Jean-Didier; Badet-Denisot, Marie-Ange; Robert, Charles H; Dauchez, Manuel; Perahia, David

    2006-10-02

    We demonstrate the utility of normal mode analysis in correctly predicting the binding modes of inhibitors in the active sites of matrix metalloproteinases (MMPs). We show the accuracy in predicting the positions of MMP-3 inhibitors is strongly dependent on which structure is used as the target, especially when it has been energy minimized. This dependency can be overcome by using intermediate structures generated along one of the normal modes previously calculated for a given target. These results may be of prime importance for further in silico drug discovery.

  15. A Davis-Putnam program and its application to finite-order model search: Quasigroup existence problems

    SciTech Connect

    McCune, W.

    1994-09-01

    This document describes the implementation and use of a Davis-Putnam procedure for the propositional satisfiability problem. It also describes code that takes statements in first-order logic with equality and a domain size n then searches for models of size n. The first-order model-searching code transforms the statements into set of propositional clauses such that the first-order statements have a model of size n if and only if the propositional clauses are satisfiable. The propositional set is then given to the Davis-Putnam code; any propositional models that are found can be translated to models of the first-order statements. The first-order model-searching program accepts statements only in a flattened relational clause form without function symbols. Additional code was written to take input statements in the language of OTTER 3.0 and produce the flattened relational form. The program was successfully applied to several open questions on the existence of orthogonal quasigroups.

  16. 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

  17. De-noising method of InSAR data based on empirical mode decomposition and land deformation monitoring application

    NASA Astrophysics Data System (ADS)

    Wang, Li; Chen, Fu; Li, Zengke; Zhang, Shaoliang

    2011-10-01

    The applicable choice of filters for InSAR is one of the key procedures, which is associated with the quality of interferogram. The data of InSAR interferogram was decomposed by empirical mode decomposition (EMD). A given signal was decomposed into different Intrinsic Mode Functions (IMFs) filled with the condition. Further investigation of the algorithm is demonstrated below with regard to the multi-resolution standpoint. Empirical mode decomposition includes two operators. The IMF calculation operator and residual calculation operator define the process of similar to high frequency and low frequency filters. Then, the multi-solution structure is realized by decomposing the low frequency step by step. Therefore, the filtered noise-related IMFs together with the other IMFs can be used to restructure the denoised signal. The processing result has confirmed this method feasibility. Comparing the empirical mode decomposition with the general methods, such as median filter, Lee filter, Goldstein filter, using the quantitative evaluation index, i.e., standard deviation (STD) and equivalent number of looks (ENL), the result shows that empirical mode decomposition is powerful to interferogram speckle noise suppression and residues reduction, as well as it can be preserved details information. The method proposed can improve the accuracy of interferometric products.

  18. 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.

  19. Novel aspect in grain size control of nanocrystalline diamond film for thin film waveguide mode resonance sensor application.

    PubMed

    Lee, Hak-Joo; Lee, Kyeong-Seok; Cho, Jung-Min; Lee, Taek-Sung; Kim, Inho; Jeong, Doo Seok; Lee, Wook-Seong

    2013-11-27

    Nanocrystalline diamond (NCD) thin film growth was systematically investigated for application for the thin film waveguide mode resonance sensor. The NCD thin film was grown on the Si wafer or on the SiO2-coated sapphire substrate using the hot filament chemical vapor deposition (HFCVD). The structural/optical properties of the samples were characterized by the high-resolution scanning electron microscopy (HRSEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDS), near edge X-ray absorption fine structure (NEXAFS), X-ray diffraction (XRD), and ultraviolet-visible (UV-vis) spectroscopy. The waveguide modes of the NCD layer were studied by prism coupler technique using laser (wavelength: 632.8 nm) with varying incident angle. A novel aspect was disclosed in the grain size dependence on the growth temperature at the relatively low methane concentration in the precursor gas, which was important for optical property: the grain size increased with decreasing growth temperature, which was contrary to the conventional knowledge prevailing in the microcrystalline diamond (MCD) domain. We have provided discussions to reconcile such observation. An optical waveguide mode resonance was demonstrated in the visible region using the microstructure-controlled transparent NCD thin film waveguide, which provided a strong potential for the waveguide mode resonance sensor applications.

  20. A novel adaptive sliding mode control with application to MEMS gyroscope.

    PubMed

    Fei, Juntao; Batur, Celal

    2009-01-01

    This paper presents a new adaptive sliding mode controller for MEMS gyroscope; an adaptive tracking controller with a proportional and integral sliding surface is proposed. The adaptive sliding mode control algorithm can estimate the angular velocity and the damping and stiffness coefficients in real time. A proportional and integral sliding surface, instead of a conventional sliding surface is adopted. An adaptive sliding mode controller that incorporates both matched and unmatched uncertainties and disturbances is derived and the stability of the closed-loop system is established. The numerical simulation is presented to verify the effectiveness of the proposed control scheme. It is shown that the proposed adaptive sliding mode control scheme offers several advantages such as the consistent estimation of gyroscope parameters including angular velocity and large robustness to parameter variations and external disturbances.

  1. Discrete mode laser diodes for FTTH/PON applications up to 10 Gbit/s

    NASA Astrophysics Data System (ADS)

    O'Carroll, John; Phelan, Richard; Kelly, Brian; Byrne, Diarmuid; Latkowski, Sylwester; Anandarajah, Prince M.; Barry, Liam P.

    2012-06-01

    Discrete Mode Laser Diodes (DMLDs) present an economic approach with a focus on high volume manufacturability of single mode lasers using a single step fabrication process. We report on a DMLD designed for operation in the 1550 nm window with high Side Mode Suppression Ratio (SMSR) over a wide temperature tuning range of -20 °C < T < 95 °C. Direct modulation rates as high as 10 Gbit/s are demonstrated at both 1550 nm and 1310 nm. Transmission experiments were also carried out over single mode fibre at both wavelengths. Using dispersion pre-compensation transmission from 0 to 60 km is demonstrated at 1550 nm with a maximum power penalty measured at 60 km of 3.6 dB.

  2. An Application of Chaotic Chua's System for Secure Chaotic Communication Based on Sliding Mode observer

    NASA Astrophysics Data System (ADS)

    Kemih, K.; Halimi, M.; Ghanes, M.; Zhang, G.

    2011-12-01

    In this paper, we study the design and implementation of analog secure communication systems via synchronized chaotic Chua's circuit with sliding mode observer. For this, we adopt an approach based on an inclusion of the message in the transmitter and in the receiver; we use a sliding mode observer with un-known input in order to recover the information. Finally, an analog electronic circuit with Multisim software is designed to physically realize the complete system (transmitter-receiver).

  3. Analysis of nonaxisymmetric vibration mode piezoelectric annular plate and its application to an ultrasonic motor.

    PubMed

    Takano, T; Hirata, H; Tomikawa, Y

    1990-01-01

    The development of an ultrasonic motor using nonaxisymmetric vibration modes of a piezoelectric annular plate is described. A piezoelectric annular plate is analyzed to find its mode patterns, elliptic motions of displacement for the motor, and the distributions of the induced charge on the plate surface, and to calculate electromechanical coupling factors. On the basis of the analyzed results, motors using the annular plate have been built and their characteristics measured. The construction and characteristics of these motors are discussed.

  4. Long-term ELF background noise measurements, the existence of window regions, and applications to earthquake precursor emission studies

    NASA Astrophysics Data System (ADS)

    Dea, Jack Y.; Hansen, Peder M.; Boerner, Wolfgang-M.

    1993-04-01

    earthquake. These other conditions include: (i) persistence of the elevation of the signals; (ii) the existence of resonance lines in the window region of the power spectrum; (iii) the Schumann peaks remaining relatively normal. Several examples of broadband precursor emissions are shown as well as a table listing all nearby moderate/large quakes that occurred during the research period and the correlation with our data base. The table showed that the periods preceding nearby quakes are usually associated with higher than average background levels in the 3-4 Hz region. The general conclusions are that more systematic research is needed, many more monitoring stations are needed, and full tri-axial electric and magnetic monitoring are required.

  5. 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

    2015-05-04

    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.

  6. 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.

  7. 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.

  8. Intermodal interferometer based on a fluid-filled two-mode photonic crystal fiber for sensing applications.

    PubMed

    Wang, Shuangxia; Liu, Yan-ge; Wang, Zhi; Han, Tingting; Xu, Weicai; Wang, Yunkun; Wang, Shangcheng

    2013-05-10

    A fluid-filled two-mode photonic crystal fiber (PCF)-based intermodal interferometer and its sensing characteristics are demonstrated and investigated. The interferometer works from the interference between LP(01) and LP(11) core modes of the fluid-filled PCF. Solutions to enhance the temperature sensitivity of the interferometer are also discussed. Via choosing a higher fluid-filled length ratio of PCF, a sensitivity of more than -340 pm/°C at 1480 nm is achieved, which is the highest value for a PCF intermodal interferometer-based sensor, to our best knowledge. Furthermore, there exist significant differences in temperature and strain sensitivity for two different interference dips, thus the interferometer can be used as a dual-parameter sensor with a compact structure through matrix demodulation.

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

    SciTech Connect

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

    2016-07-14

    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/με in the parallel direction and 0.109 ppm/με in the perpendicular direction, while the corresponding values for the STW mode are 0.680 ppm/με and 0.189 ppm/με, respectively.

  10. 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. Copyright © 2016 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  11. 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.

  12. 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.

  13. Application of the confluent Heun functions for finding the quasinormal modes of nonrotating black holes

    NASA Astrophysics Data System (ADS)

    Fiziev, Plamen; Staicova, Denitsa

    2011-12-01

    Although finding numerically the quasinormal modes of a nonrotating black hole is a well-studied question, the physics of the problem is often hidden behind complicated numerical procedures aimed at avoiding the direct solution of the spectral system in this case. In this article, we use the exact analytical solutions of the Regge-Wheeler equation and the Teukolsky radial equation, written in terms of confluent Heun functions. In both cases, we obtain the quasinormal modes numerically from spectral condition written in terms of the Heun functions. The frequencies are compared with ones already published by Andersson and other authors. A new method of studying the branch cuts in the solutions is presented—the epsilon method. In particular, we prove that the mode n=8 is not algebraically special and find its value with more than 6 firm figures of precision for the first time. The stability of that mode is explored using the ɛ method, and the results show that this new method provides a natural way of studying the behavior of the modes around the branch cut points.

  14. Engineering of optical modes in vertical-cavity microresonators by aperture placement: applications to single-mode and near-field lasers

    NASA Astrophysics Data System (ADS)

    Shchukin, V. A.; Ledentsov, N. N.; Kropp, J.-R.; Steinle, G.; Ledentsov, N. N.; Choquette, K. D.; Burger, S.; Schmidt, F.

    2015-03-01

    Oxide-confined vertical cavity surface emitting lasers (VCSEL) are inherently leaky structures, despite the fact that the oxidized periphery region surrounding the all-semiconductor core has a lower refractive index. The reason is that the VCSEL modes in the non-oxidized core region can be coupled to tilted modes in the selectively oxidized periphery as the orthogonality between the core mode and the modes at the periphery is broken by the oxidation-induced optical field redistribution. Engineered VCSEL designs show that the overlap between the VCSEL mode of the core and the tilted mode in the periphery can reach >30% resulting in significant leakage. Three-dimensional modeling confirms that the leakage losses are much stronger for high order transverse modes which have a higher field intensity close to the oxidized region. Single mode lasing in the fundamental mode can thus proceed up to large aperture diameters. A 850-nm GaAlAs leaky VCSEL based on this concept is designed, modeled and fabricated, showing single-mode lasing with aperture diameters up to 5 μm. Side mode suppression ratio >20dB is realized at the current density of 10kA/cm2 in devices with the series resistance of 90 Ω.

  15. Application theory of scattering and coupled mode analysis for liquid crystal diffractive grating.

    PubMed

    Kreymerman, Grigoriy

    2010-07-19

    This work presents a detailed analysis of a liquid crystal (LC) phase diffraction grating based on a approach combining vector theory of scattering and coupled mode analysis. In general, the coupled mode analysis gives a solution for the diffracted field regardless of aperture and the polarization state of the incident light. However, the aperture of the incident light defines the angular selectivity of the diffraction grating as well as the distribution of the intensity of the diffractive maximums. The solution of the vector theory of scattering in combination with the coupled mode analysis for diffraction of the light beam with finite aperture has allowed one to optimize the parameters of the high efficiency diffractive LC grating. The analytic solutions here were verified with experimental results for a reverse-twisted LC grating and a comparison with the standard Gooch-Tarry's method, which typically applied for a twisted nematic LC display.

  16. Application of coupled mode theory on radiative heat transfer between layered Lorentz materials

    NASA Astrophysics Data System (ADS)

    Lin, Chungwei; Wang, Bingnan; Teo, Koon Hoo

    2017-05-01

    The coupled mode theory (CMT) provides a simple and clear framework to analyze the radiation energy exchange between reservoirs. We apply CMT to analyze the radiative heat transfer between layered Lorentz materials whose dielectric functions can be approximated by the Lorentz oscillator model. By comparing the transmissivity computed by the exact solution to that computed by CMT, we find that CMT generally gives a good approximation for this class of materials. The biggest advantage of CMT analysis, in our opinion, is that only the (complex) resonant energies are needed to obtain the radiation energy transfer; the knowledge of the spatial profile of resonances is not required. Several issues, including how to choose the resonant modes, what these modes represent, and the limitation of this method, are discussed. Finally, we also apply the CMT method to the electronic systems, demonstrating the generality of this formalism.

  17. 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.

  18. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2012-09-01

    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.

  20. Contrast Enhanced Superharmonic Imaging for Acoustic Angiography Using Reduced Form-Factor Lateral Mode Transmitters for Intravascular and Intracavity Applications.

    PubMed

    Wang, Zhuochen; Heath Martin, K; Huang, Wenbin; Dayton, Paul A; Jiang, Xiaoning

    2017-02-01

    Techniques to image the microvasculature may play an important role in imaging tumor-related angiogenesis and vasa vasorum associated with vulnerable atherosclerotic plaques. However, the microvasculature associated with these pathologies is difficult to detect using traditional B-mode ultrasound or even harmonic imaging due to small vessel size and poor differentiation from surrounding tissue. Acoustic angiography, a microvascular imaging technique that utilizes superharmonic imaging (detection of higher order harmonics of microbubble response), can yield a much higher contrast-to-tissue ratio than second harmonic imaging methods. In this paper, two dual-frequency transducers using lateral mode transmitters were developed for superharmonic detection and acoustic angiography imaging in intracavity applications. A single element dual-frequency intravascular ultrasound transducer was developed for concept validation, which achieved larger signal amplitude, better contrast-to-noise ratio (CNR), and pulselength compared to the previous work. A dual-frequency [Pb(Mg1/3Nb2/3)O3]-x[PbTiO3] array transducer was then developed for superharmonic imaging with dynamic focusing. The axial and lateral sizes of the microbubbles in a 200- [Formula: see text] tube were measured to be 269 and [Formula: see text], respectively. The maximum CNR was calculated to be 22 dB. These results show that superharmonic imaging with a low frequency lateral mode transmitter is a feasible alternative to thickness mode transmitters when the final transducer size requirements dictate design choices.

  1. A high-efficiency tunable TEM-TE11 mode converter for high-power microwave applications

    NASA Astrophysics Data System (ADS)

    Wang, Xiao-Yu; Fan, Yu-Wei; Shu, Ting; Yuan, Cheng-wei; Zhang, Qiang

    2017-03-01

    The tunable high power microwave source (HPM's) is considered to be an important research direction. However, the corresponding mode converter has been researched little. In this paper, a high-efficiency tunable mode converter (HETMC) is investigated for high-power microwave applications. The HETMC that is consisted of coaxial inner and outer conductors, with four metal plates arranged radially, at 90° in the coaxial gap, and matching rods can transform coaxial transverse electromagnetic (TEM) mode to TE11 coaxial waveguide mode. The results show that adjusting the length of the downstream plate, and the distance between the rods installed upstream and the closest edges of the plates, can improve the conversion efficiency and bandwidth remarkably. Moreover, when the frequency ranges from 1.63 GHz to 2.12 GHz, the conversion efficiency is above 95% between 1.63 GHz and 2.12 GHz with a bandwidth of 26.1%. Besides, the unwished reflection and transmission can be eliminated effectively in the HETMC.

  2. 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

  3. 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.

  4. Working with Existing Databases

    PubMed Central

    Murphy, Melissa; Alavi, Karim; Maykel, Justin

    2013-01-01

    Outcomes research has established itself as an integral part of surgical research as physicians and hospitals are increasingly required to demonstrate attainment of performance markers and surgical safety indicators. Large-volume and clinical and administrative databases are used to study regional practice pattern variations, health care disparities, and resource utilization. Understanding the unique strengths and limitations of these large databases is critical to performing quality surgical outcomes research. In the current work, we review the currently available large-volume databases including selection processes, modes of analyses, data application, and limitations. PMID:24436641

  5. [Development and applications of the extracorporeal control point module on multi-mode medical images].

    PubMed

    Chen, Zhao-Qiu; Zhao, Feng-Ling; Zhu, Jian; Li, Wan-Hu; Fu, Zheng; Hu, Xu-Dong

    2008-07-01

    This paper introduces a display module which can be used on multi-mode medical images. The module has a small size and can be easily used for point-selecting puncture diagnosis and treatment, and registration for image fusion control points.

  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. Application of empirical mode decomposition and Teager energy operator to EEG signals for mental task classification.

    PubMed

    Kaleem, M F; Sugavaneswaran, L; Guergachi, A; Krishnan, S

    2010-01-01

    This paper presents a novel method for mental task classification from EEG signals using Empirical Mode Decomposition and Teager energy operator techniques on EEG data. The efficacy of these techniques for non-stationary and non-linear data has already been demonstrated, which therefore lend themselves well to EEG signals, which are also non-stationary and non-linear in nature. The method described in this paper decomposed the EEG signals (6 EEG signals per task per subject, for a total of 5 tasks over multiple trials) into their constituent oscillatory modes, called intrinsic mode functions, and separated out the trend from the signal. Teager energy operator was used to calculate the average energy of both the detrended signal and the trend. The average energy was used to construct separate feature vectors with a small number of parameters for the detrended signal and the trend. Based on these parameters, one-versus-one classification of mental tasks was performed using Linear Discriminant Analysis. Using both feature vectors, an average correct classification rate of more than 85% was achieved, demonstrating the effectiveness of the method used. Furthermore, this method used all the intrinsic mode functions, as opposed to similar studies, demonstrating that the trend of the EEG signal also contains important discriminatory information.

  8. Single-Mode Waveguides With SU-8 Polymer Core and Cladding for MOEMS Applications

    NASA Astrophysics Data System (ADS)

    Nordström, Maria; Zauner, Dan A.; Boisen, Anja; Hübner, Jörg

    2007-05-01

    Fabrication and optical characterization of single-mode polymeric embedded waveguides are performed. A specific material combination (SU-8 2005 as core and the modified SU-8 mr-L 6050XP as cladding) is chosen in order to obtain a small refractive index difference for single-mode propagation combined with the conventional fabrication method UV lithography to facilitate the integration of different types of optical detection methods on lab-on-a-chip systems. We analyze the behavior of the refractive index and carefully observe how the value of the refractive index can be tailored during processing. We show that we can fabricate waveguides with an index difference in the order of 10-3, where both the core material and the cladding material are based on SU-8. The refractive index measurements are performed on thin polymeric films, while further optical characterizations are performed on waveguides with a height of 4.5 µm. We study the mode profiles of these waveguides and confirm that only the fundamental mode is excited. We also study the absorption spectra of the material in the wavelength range 800 1600 nm combined with cut-back measurements. We find that the waveguides have a propagation loss of 0.2 3 dB/cm in this wavelength range.

  9. 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

  10. On the existence, uniqueness, and asymptotic normality of a consistent solution of the likelihood equations for nonidentically distributed observations: Applications to missing data problems

    NASA Technical Reports Server (NTRS)

    Peters, C. (Principal Investigator)

    1980-01-01

    A general theorem is given which establishes the existence and uniqueness of a consistent solution of the likelihood equations given a sequence of independent random vectors whose distributions are not identical but have the same parameter set. In addition, it is shown that the consistent solution is a MLE and that it is asymptotically normal and efficient. Two applications are discussed: one in which independent observations of a normal random vector have missing components, and the other in which the parameters in a mixture from an exponential family are estimated using independent homogeneous sample blocks of different sizes.

  11. Amplitude-Mode Spectroscopy of Charge Excitations in PTB7 π -Conjugated Donor-Acceptor Copolymer for Photovoltaic Applications

    NASA Astrophysics Data System (ADS)

    Baniya, Sangita; Vardeny, Shai R.; Lafalce, Evan; Peygambarian, Nasser; Vardeny, Z. Valy

    2017-06-01

    We measure the spectra of resonant Raman scattering and doping-induced absorption of pristine films of the π -conjugated donor-acceptor (D -A ) copolymer, namely, thieno[3,4 b]thiophene-alt-benzodithiophene (PTB7), as well as photoinduced absorption spectrum in a blend of PTB7 with fullerene phenyl-C61-butyric acid methyl ester molecules used for organic photovoltaic (OPV) applications. We find that the D -A copolymer contains six strongly coupled vibrational modes having relatively strong Raman-scattering intensity, which are renormalized upon adding charge polarons onto the copolymer chains either by doping or photogeneration. Since the lower-energy charge-polaron absorption band overlaps with the renormalized vibrational modes, they appear as antiresonance lines superposed onto the induced polaron absorption band in the photoinduced absorption spectrum but less so in the doping-induced absorption spectrum. We show that the Raman-scattering, doping-, and photoinduced absorption spectra of PTB7 are well explained by the amplitude mode model, where a single vibrational propagator describes the renormalized modes and their related intensities in detail. From the relative strengths of the induced infrared activity of the polaron-related vibrations and electronic transitions, we obtain the polaron effective kinetic mass in PTB7 using the amplitude mode model to be approximately 3.8 m* , where m* is the electron effective mass. The enhanced polaronic mass in PTB7 may limit the charge mobility, which, in turn, reduces the OPV solar-cell efficiency based on the PTB7-fullerene blend.

  12. 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.

  13. A new approach of denoising the regular and chaotic signals using Empirical Mode Decomposition: comparison and application.

    PubMed

    Siwal, Davinder; Suyal, Vinita; Prasad, Awadhesh; Mandal, S; Singh, R

    2013-07-01

    The Empirical Mode Decomposition has been used to present a new approach for denoising of regular and chaotic time series originating from the nonlinear systems. The proposed filtering approach is based on the frequency distribution of different Intrinsic Mode Functions (IMFs). It provides complete frequency and noise strength information present in the data set. The actual frequencies in an experimental data set are distributed among different IMFs which are subsequently disentangled through the algorithm resulting into filtered as well as noise components. The filtered signal is produced only after a suppression (hard threshold) of noise components. The noise strength present in the data set is produced by the identified noisy IMFs. This innovative approach has been tested for linear, nonlinear, and chaotic types of calculated data sets with various levels of simulated noise strengths and results have been compared with the existing methods. The validity of the present approach is confirmed by experimentally observed astrophysical data as well as data from a neutron detector. A sharp improvement in the signal strength has been observed with the proposed method in comparison to the existing methods.

  14. Single-mode vertically integrated waveguide photodetectors for WDM data receiver applications

    NASA Astrophysics Data System (ADS)

    Densmore, Adam S.; Pimenov, Kirill; Tolstikhin, Valery I.

    2004-12-01

    The advantages of monolithic integration of passive and active optoelectronic components into multifunctional PICs (photonic integrated circuits) are numerous and well known. In WDM transmission systems, where up to hundreds of wavelength channels may be present and must be manipulated on a per wavelength basis, the advantages of PICs containing wavelength (de)multiplexers and arrays of active components rapidly multiply. This has been exploited in our earlier reported SurePath family of InP-based PICs for optical channel monitoring / equalization, which contain an echelle grating demultiplexer and single-mode vertically integrated waveguide photodetectors / electroabsorption attenuators inserted into each of its output channels. Now, the same design principles and fabrication techniques have been utilized for the development of a dense WDM data receiver. This paper concentrates on the key building block of such a component, the single-mode vertically integrated waveguide photodetector. A detailed characterization and analysis of the device performance are presented.

  15. Propagation of quasi-static modes in anisotropic transmission lines: application to MIC lines

    SciTech Connect

    Marques, R.; Horno, M.

    1985-10-01

    In this paper, we analyze the field propagation in a general N-conductor transmission line embedded in an inhomogeneous and anisotropic medium, through the series expansion of the field in powers of frequency. The quasi-static approach is deducted as a zero-order approach upon the field and a first-order approach for the propagation constant. It is shown that it is even possible to decompose the field into a sum of propagating modes with a scalar propagation factor. The special case of transmission lines in nonmagnetic media is explicitly considered. A method to find out the mode characteristics of any open planar MIC line with anisotropic dielectric substrates is developed and applied to some MIC structures of interest, specifically broadside edgecoupled microstrips with inverted and noninverted substrates.

  16. 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; CenterNanoscale 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.

  17. Low-Mode Conformational Search Method with Semiempirical Quantum Mechanical Calculations: Application to Enantioselective Organocatalysis.

    PubMed

    Kamachi, Takashi; Yoshizawa, Kazunari

    2016-02-22

    A conformational search program for finding low-energy conformations of large noncovalent complexes has been developed. A quantitatively reliable semiempirical quantum mechanical PM6-DH+ method, which is able to accurately describe noncovalent interactions at a low computational cost, was employed in contrast to conventional conformational search programs in which molecular mechanical methods are usually adopted. Our approach is based on the low-mode method whereby an initial structure is perturbed along one of its low-mode eigenvectors to generate new conformations. This method was applied to determine the most stable conformation of transition state for enantioselective alkylation by the Maruoka and cinchona alkaloid catalysts and Hantzsch ester hydrogenation of imines by chiral phosphoric acid. Besides successfully reproducing the previously reported most stable DFT conformations, the conformational search with the semiempirical quantum mechanical calculations newly discovered a more stable conformation at a low computational cost.

  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 [New Delhi, IN; Suryanarayanan, Siddharth [Littleton, CO

    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. A New Type of Current Conveyor and its Application in Fully Balanced Differential Current-Mode Elliptic Filter Design

    NASA Astrophysics Data System (ADS)

    Zhang, Qiujing; Wang, Chunhua; Sun, Jingru; Du, Sichun

    2011-05-01

    This paper introduces a new type of CMOS-based current conveyor: current controlled fully balanced second generation current conveyor (CFBCCII) element which has a pair of differential Y terminals, a pair of differential X terminals and two pairs of Z terminals. The proposed circuit offers electronic tuning possibilities by means of a current adjustable intrinsic resistance at its X terminal. An elliptic filter realization is described as an example for its application in a current-mode fully balanced filter design, where the intrinsic resistors in CFBCCIIs are used for the electronic tuning of the characteristic filter frequency.

  1. Application of the mode-shape expansion based on model order reduction methods to a composite structure

    NASA Astrophysics Data System (ADS)

    Fuentes, Humberto Peredo

    2017-09-01

    The application of different mode-shape expansion (MSE) methods to a CFRP based on model order reduction (MOR) and component mode synthesis (CMS) methods is evaluated combining the updated stiffness parameters of the full FE model obtained with a mix-numerical experimental technique (MNET) in a previous work. The eigenvectors and eigenfrequencies of the different MSE methods obtained are compared with respect to the experimental measurements and with a full FE model solutions using the modal assurance criteria (MAC). Furthermore, the stiffness and mass weighted coefficients (K-MAC and M-MAC respectively) are calculated and compared to observe the influence of the different subspace based expansion methods applying the MAC criteria. The K-MAC and M-MAC are basically the MAC coefficients weighted by a partition of the global stiffness and mass matrices respectively. The best K-MAC and M-MAC results per paired mode-sensor are observed in the subspace based expansion MODAL/SEREP and MDRE-WE methods using the updated stiffness parameters. A strong influence of the subspace based on MOR using MSE methods is observed in the K-MAC and M-MAC criteria implemented in SDTools evaluating the stiffness parameters in a contrieved example.

  2. Carbon Nanotube-Poly(vinylalcohol) Nanocomposite Film Devices: Applications for Femtosecond Fiber Laser Mode Lockers and Optical Amplifier Noise Suppressors

    NASA Astrophysics Data System (ADS)

    Sakakibara, Youichi; Rozhin, Aleksey G.; Kataura, Hiromichi; Achiba, Yohji; Tokumoto, Madoka

    2005-04-01

    We fabricated single-wall carbon nanotube (SWNT)/poly(vinylalcohol) (PVA) nanocomposite freestanding films and examined their application in devices in which the saturable absorption of SWNTs at near-infrared optical telecommunication wavelengths can be utilized. In a passively mode-locked fiber laser, we integrated a 30-μm-thick SWNT/PVA film into a fiber connection adaptor with the film sandwiched by a pair of fiber ferrules. A ring fiber laser with a SWNT/PVA saturable absorber was operated very easily in the mode-locked short-pulse mode with a pulse width of about 500 fs. Reproducible stable device performance was confirmed. In examining noise suppression for optical amplifiers, mixed light of semiconductor amplified spontaneous emission (ASE) source and 370 fs laser pulses was passed through a 100-μm-thick SWNT/PVA film. The transmission loss of the femtosecond pulse light was smaller than that of the ASE light. This proved that the SWNT/PVA film has the ability to suppress ASE noise.

  3. Coherent interaction between two orthogonal travelling-wave modes in a microdonut resonator for filtering and buffering applications.

    PubMed

    Huang, Qingzhong; Yu, Jinzhong

    2014-10-20

    We theoretically investigate the coherent interaction between two orthogonal travelling-wave modes in a microdonut resonator symmetrically coupled to two bus waveguides. An analytical model has been developed to describe this structure using transfer matrix method. The simulation reveals that the two-mode microdonut can exhibit either a flat-top response or all-pass transmission, governed by the resonance spacing. Then, we implement analytical simulations to characterize the device and analyze the influence of coupling efficiencies and propagation losses of two resonant modes on behavior. Consequently, finite difference time domain simulations have been performed. The numerical results validate our theoretical analysis, and optical buffering effect is demonstrated in a pulse propagation simulation, when the two resonances are aligned. In addition, we show that the device function can be switched between flat-top filtering and all-pass filtering by tuning the local refractive index in a microdonut. Hence, this structure is promising for on-chip optical filtering and buffering applications.

  4. 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.

  5. Application of Empirical Mode Decomposition with Local Linear Quantile Regression in Financial Time Series Forecasting

    PubMed Central

    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. 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.

  7. 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.

  8. 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.

  9. Effect of Dentin Moisture and Application Mode of Universal Adhesives on the Adhesion of Glass Fiber Posts to Root Canal.

    PubMed

    Gruber, Yançanã Luizy; Bakaus, Thaís Emanuelle; Gomes, Osnara Maria Mongruel; Reis, Alessandra; Gomes, Giovana Mongruel

    2017-09-21

    To evaluate the effect of dentin moisture and application mode of universal adhesives on bond strength (BS) and nanoleakage (NL) of fiber posts bonded to root dentin. The roots of 96 extracted human canines were treated endodontically, and the fiber posts were cemented according to the combination of the following factors: dentin moisture (dry and wet), cementation system [Single Bond Universal/RelyX ARC (SBU) and Prime&Bond elect/Enforce (PBE)], and adhesive application [active (A) and passive (P)] in accordance with the manufacturer's instructions. After one week, the specimens were transversely sectioned into six 1-mm-thick disks. From each group, 8 specimens were subjected to the pushout BS test and the other 4 specimens underwent NL analysis. For both tests, the data were subjected to 3-way repeated measures ANOVA and Tukey's tests (α = 0.05). For BS and NL, the cross-product interaction of all factors was significant (p < 0.05). Lower BS was observed under P application independent of the dentin moisture; for A application, SBU showed higher BS than did PBE in both moisture conditions. Nanoleakage was present in all groups and ranged from 22.9% to 36%. The active application of universal adhesives improves the adhesion in fiber post cementation, independent of dentin moisture condition.

  10. Application of empirical mode decomposition to a Jeffcott rotor with a breathing crack

    NASA Astrophysics Data System (ADS)

    Guo, C.; AL-Shudeifat, M. A.; Yan, J.; Bergman, L. A.; McFarland, D. M.; Butcher, E. A.

    2013-08-01

    Fatigue damage, appearing due to developing cracks, is considered to be one of the main faults in rotating machinery. The damage in rotating components can be catastrophic, posing a potential hazard and leading to significant economic loss. In the related literature, transverse breathing cracks are considered as a primary mode of damage. Accordingly, a Jeffcott rotor with a transverse breathing crack has been examined here wherein a method for identifying the early crack propagation is proposed. The breathing functions developed in a recent publication to approximate the actual breathing mechanism of the cracked shaft are employed along with the method of empirical mode decomposition (EMD) to identify the crack vibration signature. EMD combined with the wave transform spectrum is used to decompose the measured vibration time series of the cracked rotor system into nearly monochromatic components. It is shown that the variations of the averaged amplitudes of the super-harmonic components in the neighborhood of 1/2 and 1/3 of the first critical rotational speed provide clear and robust vibration signatures indicating the early presence of the breathing crack. This signature is utilized here for early crack detection in the rotor system under consideration.

  11. Normal modes of symmetric protein assemblies. Application to the tobacco mosaic virus protein disk.

    PubMed Central

    Simonson, T; Perahia, D

    1992-01-01

    We use group theoretical methods to study the molecular dynamics of symmetric protein multimers in the harmonic or quasiharmonic approximation. The method explicitly includes the long-range correlations between protein subunits. It can thus address collective dynamic effects, such as cooperativity between subunits. The n lowest-frequency normal modes of each individual subunit are combined into symmetry coordinates for the entire multimer. The Hessian of the potential energy is thereby reduced to a series of blocks of order n or 2n. In the quasiharmonic approximation, the covariance matrix of the atomic oscillations is reduced to the same block structure by an analogous set of symmetry coordinates. The method is applied to one layer of the tobacco mosaic virus protein disk in vacuo, to gain insight into the role of conformational fluctuations and electrostatics in tobacco mosaic virus assembly. The system has 78,000 classical, positional, degrees of freedom, yet the calculation is reduced by symmetry to a problem of order 4,600. Normal modes in the 0-100 cm-1 range were calculated. The calculated correlations extend mainly from each subunit to its nearest neighbors. The network of core helices has weak correlations with the rest of the structure. Similarly, the inner loops 90-108 are uncorrelated with the rest of the structure. Thus, the model predicts that the dielectric response in the RNA-binding region is mainly due to the loops alone. Images FIGURE 1 FIGURE 3 FIGURE 5 FIGURE 7 FIGURE 8 PMID:1547329

  12. Nonaxisymmetric Dynamic Instabilities of Rotating Polytropes. II. Torques, Bars, and Mode Saturation with Applications to Protostars and Fizzlers

    NASA Astrophysics Data System (ADS)

    Imamura, James N.; Durisen, Richard H.; Pickett, Brian K.

    2000-01-01

    Dynamic nonaxisymmetric instabilities in rapidly rotating stars and protostars have a range of potential applications in astrophysics, including implications for binary formation during protostellar cloud collapse and for the possibility of aborted collapse to neutron star densities at late stages of stellar evolution (``fizzlers''). We have recently presented detailed linear analyses for polytropes of the most dynamically unstable global modes, the barlike modes. These produce bar distortions in the regions near the rotation axis but have trailing spiral arms toward the equator. In this paper, we use our linear eigenfunctions to predict the early nonlinear behavior of the dynamic instability and compare these ``quasi-linear'' predictions with several fully nonlinear hydrodynamics simulations. The comparisons demonstrate that the nonlinear saturation of the barlike instability is due to the self-interaction gravitational torques between the growing central bar and the spiral arms, where angular momentum is transferred outward from bar to arms. We also find a previously unsuspected resonance condition that accurately predicts the mass of the bar regions in our own simulations and in those published by other researchers. The quasi-linear theory makes other accurate predictions about consequences of instability, including properties of possible end-state bars and increases in central density, which can be large under some conditions. We discuss in some detail the application of our results to binary formation during protostellar collapse and to the formation of massive rotating black holes.

  13. The implementation of HPGR mills in existing grinding circuits

    SciTech Connect

    Patzelt, N.; Knecht, J.; Longhurst, D.

    1996-12-31

    High pressure grinding mills have been successfully introduced in the industry. They offer the possibilities for capacity increase of existing plants and reduction of operating costs. The plants in operation are running in different applications and modes of operation. They can be installed in a combination with SAG and ball mills or in a stand-alone mode. In combination with other grinding mills, it has to be investigated how the HPGR can be installed to reach the full efficiency. This paper describes the possibilities of implementing high pressure grinding rolls and shows by case studies the potential of savings which could be reached.

  14. 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.

  15. 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.

  16. Microwave processing and diagnosis of chemically reacting materials in a single-mode cavity applicator

    NASA Astrophysics Data System (ADS)

    Jow, Jinder; Hawley, Martin C.; Finzel, Mark; Asmussen, Jes, Jr.; Lin, Haw-Hwa

    1987-12-01

    Online microwave processing and dielectric diagnosis of chemically reacting materials (epoxy/amine) have been successfully performed using a TM012-mode cylindrical cavity at a frequency of 2.45 GHz in conjunction with fluoroptic temperature measurement. Complex permittivity measurements by this single-frequency technique are repeatable and consistent with those obtained by conventional swept-frequency methods. The accuracy of complex permittivity measurements for both methods is within + or - 5 percent for permittivity and + or - 15 percent for loss. Both techniques are based on material-cavity perturbation theory. Perturbation equations for cylindrical shapes of the cavity and loaded material were derived to account for volume variation of the sample due to thermal expansion. Complex permittivity of epoxy/amine as a function of the extent of cure and temperature was determined in order to monitor the chemical reaction progress during microwave processing.

  17. 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.

  18. Explosive reconnection of double tearing modes in relativistic plasmas: application to the Crab flares

    NASA Astrophysics Data System (ADS)

    Baty, H.; Petri, J.; Zenitani, S.

    2013-11-01

    Magnetic reconnection associated to the double tearing mode is investigated by means of resistive relativistic magnetohydrodynamic simulations. A linearly unstable double current sheet system in two-dimensional Cartesian geometry is considered. For initial perturbations of large enough longitudinal wavelengths, a fast reconnection event is triggered by a secondary instability that is structurally driven by the non-linear evolution of the magnetic islands. The latter reconnection phase and time-scale appear to weakly depend on the plasma resistivity and magnetization parameter. We discuss the possible role of such explosive reconnection dynamics to explain the MeV flares observed in the Crab Pulsar nebula. Indeed, the time-scale and the critical minimum wavelength give constraints on the Lorentz factor of the striped wind and on the location of the emission region, respectively.

  19. Analysis of standby and demand stress failures modes. Methodology and applications to EDGs and MOVs

    SciTech Connect

    Lofgren, E.V.; Thaggard, M.

    1992-10-01

    This report describes work to develop and demonstrates methods for partitioning standby component failure modes into causes that fail the component while it is in standby, and when it changes state, during testing or from other demands. Failure of the component from standby stresses is modeled using a model that explicitly contains the length of the test interval. Failure of the component from demand stresses such as vibration, wind, etc., is modeled using the probability of failure on demand model. Misuse of these models in PRAS, could lead to PRAs that, give misleading results, or that are more useful for decision purposes. A method was developed and demonstrated to partition standby/demand stresses. The method was used on the work maintenance records from two Nuclear Power Plants (NPPs) to estimate reliability parameters for Motor Operated Valves And Emergency Diesel Generators (EDGs).

  20. 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] -->

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

    PubMed Central

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

    2016-01-01

    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

  2. High resolution gas ionization chamber in proportional mode for low energy applications

    NASA Astrophysics Data System (ADS)

    Müller, Arnold Milenko; Döbeli, Max; Synal, Hans-Arno

    2017-09-01

    The operation of the ETH gas ionization detector as a proportional chamber, where a secondary ionization avalanche is initiated between the Frisch grid and anode, was investigated for ions covering the mass range from H to 127I. By amplifying the detector electron signal through secondary ionization, the limitations due to the sensitivity of the detector electronics are minimized. It could be demonstrated that in the energy range of a few hundreds of keV and below a proportional chamber clearly outperforms a conventionally used gas ionization detector. Protons below 10 keV were measured with a resolution better than 1.4 keV and a good linearity of the particle energy and detector signal was found in the energy range between 50 and 1000 keV. At higher energies almost no difference in resolution for the two operation modes could be found.

  3. 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. © 2016 The Author(s).

  4. 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.

  5. 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.

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

    PubMed Central

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

    2012-01-01

    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

  7. 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.

  8. A Study on the Training Mode of Electronic Application-Oriented Undergraduate with Industry Needs

    ERIC Educational Resources Information Center

    Wang, Zhonghua; Cheng, Lifang; Wang, Hao

    2017-01-01

    Electronic industry is an economic pillar in China. Due to the Moore's Law, the industry requires continuous development and innovation. In order to achieve these goals, the cultivation of electronic application-oriented undergraduate is essential. However, at current, the innovative educational concepts and teaching methods are lagging behind so…

  9. Undamped critical speeds of rotor systems using assumed modes

    NASA Astrophysics Data System (ADS)

    Nelson, H. D.; Chen, W. J.

    1993-07-01

    A procedure is presented to reduce the DOF of a discrete rotordynamics model by utilizing an assumed-modes Rayleigh-Ritz approximation. Many possibilities exist for the assumed modes and any reasonable choice will yield a reduced-order model with adequate accuracy for most applications. The procedure provides an option which can be implemented with relative ease and may prove beneficial for many applications where computational efficiency is particularly important.

  10. 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.

  11. Evaluating the application of failure mode and effects analysis technique in hospital wards: a systematic review

    PubMed Central

    Asgari Dastjerdi, Hoori; Khorasani, Elahe; Yarmohammadian, Mohammad Hossein; Ahmadzade, Mahdiye Sadat

    2017-01-01

    Abstract: Background: Medical errors are one of the greatest problems in any healthcare systems. The best way to prevent such problems is errors identification and their roots. Failure Mode and Effects Analysis (FMEA) technique is a prospective risk analysis method. This study is a review of risk analysis using FMEA technique in different hospital wards and departments. Methods: This paper has systematically investigated the available databases. After selecting inclusion and exclusion criteria, the related studies were found. This selection was made in two steps. First, the abstracts and titles were investigated by the researchers and, after omitting papers which did not meet the inclusion criteria, 22 papers were finally selected and the text was thoroughly examined. At the end, the results were obtained. Results: The examined papers had focused mostly on the process and had been conducted in the pediatric wards and radiology departments, and most participants were nursing staffs. Many of these papers attempted to express almost all the steps of model implementation; and after implementing the strategies and interventions, the Risk Priority Number (RPN) was calculated to determine the degree of the technique’s effect. However, these papers have paid less attention to the identification of risk effects. Conclusions: The study revealed that a small number of studies had failed to show the FMEA technique effects. In general, however, most of the studies recommended this technique and had considered it a useful and efficient method in reducing the number of risks and improving service quality. PMID:28039688

  12. Challenges and implementation aspects of switched-mode power supplies with digital control for automotive applications

    NASA Astrophysics Data System (ADS)

    Quenzer-Hohmuth, Samuel; Rosahl, Thoralf; Ritzmann, Steffen; Wicht, Bernhard

    2016-09-01

    Switched-mode power supplies (SMPS) convert an input DC-voltage into a higher or lower output voltage. In automotive, analog control is mostly used in order to keep the required output voltages constant and resistant to disturbances. The design of robust analog control for SMPS faces parameter variations of integrated and external passive components. Using digital control, parameter variations can be eliminated and the required area for the integrated circuit can be reduced at the same time. Digital control design bears challenges like the prevention of limit cycle oscillations and controller-wind-up. This paper reviews how to prevent these effects. Digital control loops introduce new sources for dead times in the control loop, for example the latency of the analog-to-digital-converter (ADC). Dead times have negative influence on the stability of the control loop, because they lead to phase delays. Consequently, low latency is one of the key requirements for analog-to-digital-converters in digitally controlled SMPS. Exploiting the example of a 500 kHz-buck converter with a crossover frequency of 70 kHz, this paper shows that the 5 µs-latency of a ΔΣ-analog-to-digital-converter leads to a reduction in phase margin of 126°. The latency is less critical for boost converters because of their inherent lower crossover frequencies. Finally, the paper shows a comparison between analog and digital control of SMPS with regard to chip area and test costs.

  13. Application of vertical-mode initialization to a limited-area model in flux form

    SciTech Connect

    Sashegyi, K.D. ); Madala, R.V. )

    1993-01-01

    The vertical-mode initialization procedure of Bourke and McGregor is applied to a limited-area weather prediction model that is formulated in flux form and is shown to be successful in reducing the undesirable gravity-wave oscillations in integrations of the numerical model. Alternative boundary conditions are developed for the scheme so that the changes to the wind at the lateral boundaries of the model are consistent with the changes in the integrated mass divergence and vorticity over the domain. The convergence of the modified scheme is shown to be rapid for two different grids. For a grid with significant topography along the lateral boundaries, use of increased diffusion in the boundary zone is shown to negatively impact the convergence of the scheme. Model integrations are performed to show the effectiveness of the scheme with improved boundary conditions in removing the gravity-wave oscillations. The results are compared with the damping of the gravity waves in the boundary zone by the time-integration scheme and by different lateral boundary treatments. The influence of noisy boundary values is also tested. 15 refs., 9 figs., 1 tab.

  14. 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.

  15. High energy, single frequency, tunable laser source operating in burst mode for space based LIDAR applications

    NASA Astrophysics Data System (ADS)

    Cosentino, Alberto; Mondello, Alessia; Sapia, Adalberto; D'Ottavi, Alessandro; Brotini, Mauro; Nava, Enzo; Stucchi, Emanuele; Trespidi, Franco; Mariottini, Cristina; Wazen, Paul; Falletto, Nicolas; Fruit, Michel

    2004-06-01

    This paper describes the laser transmitter assembly used in the ALADIN instrument currently in C/D development phase for the ESA ADM-AEOLUS mission (EADS Astrium as prime contractor for the satellite and the instrument). The Laser Transmitter Assembly (TXA), based on a diode pumped tripled Nd:YAG laser, is used to generate tunable laser pulses of 150 mJ at a nominal wavelength of 355 nm. This laser is operated in burst mode, with a pulse repetition cycle of 100 Hz. The TXA is composed of the following units: a diode-pumped CW Nd:YAG Laser named Reference Laser Head (RLH), used to inject a diode-pumped, Q-switched, amplified and frequency tripled Nd:YAG Laser working in the third harmonic referred as Power Laser Head (PLH) and a Transmitter Laser Electronics (TLE) containing all the control and power electronics needed for PLH and RLH operation. The TXA is made by an European consortium under the leadership of Galileo Avionica (It), and including CESI (It), Quantel (Fr), TESAT (Ge) and Thales (Fr).

  16. K-space linear Fourier domain mode locked laser and applications for optical coherence tomography.

    PubMed

    Eigenwillig, Christoph M; Biedermann, Benjamin R; Palte, Gesa; Huber, Robert

    2008-06-09

    We report on a Fourier Domain Mode Locked (FDML) wavelength swept laser source with a highly linear time-frequency sweep characteristic and demonstrate OCT imaging without k-space resampling prior to Fourier transformation. A detailed theoretical framework is provided and different strategies how to determine the optimum drive waveform of the piezo-electrically actuated optical bandpass-filter in the FDML laser are discussed. An FDML laser with a relative optical frequency deviation ??nu/nu smaller than 8 x10(-5) over a 100 nm spectral bandwidth at 1300 nm is presented, enabling high resolution OCT over long ranging depths. Without numerical time-to-frequency resampling and without spectral apodization a sensitivity roll off of 4 dB over 2 mm, 12.5 dB over 4 mm and 26.5 dB over 1 cm at 3.5 mus sweep duration and 106.6 dB maximum sensitivity at 9.2 mW average power is achieved. The axial resolution in air degrades from 14 to 21 mum over 4 mm imaging depth. The compensation of unbalanced dispersion in the OCT sample arm by an adapted tuning characteristic of the source is demonstrated. Good stability of the system without feedback-control loops is observed over hours.

  17. Connection Between the SU(3) Algebraic Model and Configuration Space for Bending Modes of Linear Molecules: Application to Acetylene

    NASA Astrophysics Data System (ADS)

    Renato, Lemus; María del Mar, Estezez-Fregozo

    2017-06-01

    An approach to connect the su(3) dynamical group- used to describe the bending modes of linear molecules- with configuration space is discussed. The SU(3) group may be seen as a consequence of adding a scalar boson to the SU(2) space of two degenerate harmonic oscillators. The resulting SU(3) group becomes the dynamical group for the bending degrees of freedom of linear molecules, but the connection to configuration space is not obvious. This work aims at providing this connection. Our approach is based on the basis of establishing a mapping between the algebraic and configuration states. An arbitrary operator in configuration space is then expanded in terms of generators of the dynamical algebra. The coefficients are determined through a minimization procedure and given in terms of matrix elements defined in configuration space. As an application we consider the vibrational description of the bending modes of the acetylene molecule, where the force constants are estimated in the framework of the U(3) × U(3) model.

  18. 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. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Development of a disruption precursor based on rotating mhd instabilities and its application to JET H-mode plasma scenario

    NASA Astrophysics Data System (ADS)

    Sozzi, Carlo; Alessi, Edoardo; Baruzzo, Matteo; Gerasimov, Sergei; JET Contributors Team

    2016-10-01

    Magneto-hydrodynamic activity often precedes disruption events in tokamaks, being either the root cause for disruption or one of the last symptoms of plasma deterioration due to a different root cause. Often a locked mode is detected before the plasma termination, with a warning time useful to trigger mitigation strategies but not enough for recovery, i.e. to act to avoid the disruption. In this work we present a study of disruption precursors derived from the Singular Value Decomposition analysis of the signals of a 3-d array of pick-up coils. Such signals are sensitive to rotating magneto-hydrodynamic activity before the locking phase. The analysis has been applied to the dataset of H-mode plasma scenario being developed at JET in preparation of the DT campaign. It is shown that using this technique a reasonable good rate of right/false alarms (81%/16%) can be obtained with an extended warning time (4-7s). Moreover, since such precursors are based on the phase analysis of normalized signals they are rather insensitive to calibration problems and show a potential for more general application.. Supported by EUROfusion Grant 633053.

  20. Excitation of surface phonon polariton modes in gold gratings with silicon carbide substrate and their potential sensing applications

    NASA Astrophysics Data System (ADS)

    Zheng, Gaige; Xu, Linhua; Zou, Xiujuan; Liu, Yuzhu

    2017-02-01

    We demonstrate the excitation of surface phonon polaritons (SPhPs) in the mid-infrared (mid-IR) Reststrahlen band (10.288 μm-12.563 μm) on patterned surfaces with silicon carbide (SiC) substrate and gold (Au) gratings. The very large negative permittivity of Au limits its applications in the mid-IR range, and to couple incident light to SPhPs modes, their momentum mismatch can be compensated by patterning Au grating onto the surface of SiC substrate. Samples were fabricated and characterized experimentally by Fourier transform infrared reflection (FTIR) spectroscopy. The optical properties were also simulated by the rigorous coupled wave analysis (RCWA) method. Reflection dips are observed for light polarized vertical to the grating lines (TM-polarized), which are attributed to the coupling of electromagnetic (EM) waves into the SPhP modes. In addition, we present small-volume index sensing with analyte specificity based on mid-IR SPhPs in the fabricated configuration.

  1. Computer-aided design (CAD) model for silicon avalanche Geiger mode systems design: Application to high sensitivity imaging systems

    NASA Astrophysics Data System (ADS)

    Jradi, K.; Pellion, D.; Esteve, D.; Boizard, J. L.; Le Padellec, A.; Bazer-Bachi, A. R.

    2011-01-01

    Our consortium CESR-LAAS in Toulouse has developed generic technology for Geiger-APD and SiPM. The main feature of these devices is the high homogeneity in breakdown voltage. The work presented here describes the model that has been used to design these devices. This also includes the integration into micro-systems, with the ambition in the long term, to develop multiple applications in astrophysics, biology, optical sensing, and above all, imaging systems. The paper is divided as follows: An introduction presents the main issues in the physics of silicon avalanche Geiger mode systems. A section (Geiger mode) divided into two parts. The first part is devoted to the electrical model of the basic device, which provides the response of the Geiger-APD to an incident photon: gain, current, and voltage. The second part presents the production of the model using Simplorer simulation software under VHDL-AMS (VHSIC—Very High Speed Integrated Circuit-Hardware Description Language-Analog and Mixed Signal) [1]. A comparison between our model and that used by Otono et al. [5] followed by a discussion with a special emphasis on presenting the noise model based on the real component made and tested by our consortium. A conclusion.

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. Design of an ultra low power third order continuous time current mode ΣΔ modulator for WLAN applications

    PubMed Central

    Behzadi, Kobra; Baghelani, Masoud

    2013-01-01

    This paper presents a third order continuous time current mode ΣΔ modulator for WLAN 802.11b standard applications. The proposed circuit utilized feedback architecture with scaled and optimized DAC coefficients. At circuit level, we propose a modified cascade current mirror integrator with reduced input impedance which results in more bandwidth and linearity and hence improves the dynamic range. Also, a very fast and precise novel dynamic latch based current comparator is introduced with low power consumption. This ultra fast comparator facilitates increasing the sampling rate toward GHz frequencies. The modulator exhibits dynamic range of more than 60 dB for 20 MHz signal bandwidth and OSR of 10 while consuming only 914 μW from 1.8 V power supply. The FoM of the modulator is calculated from two different methods, and excellent performance is achieved for proposed modulator. PMID:25685504

  7. 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.

  8. 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

  9. Clinical implementation and failure mode and effects analysis of HDR skin brachytherapy using Valencia and Leipzig surface applicators.

    PubMed

    Sayler, Elaine; Eldredge-Hindy, Harriet; Dinome, Jessie; Lockamy, Virginia; Harrison, Amy S

    2015-01-01

    The planning procedure for Valencia and Leipzig surface applicators (VLSAs) (Nucletron, Veenendaal, The Netherlands) differs substantially from CT-based planning; the unfamiliarity could lead to significant errors. This study applies failure modes and effects analysis (FMEA) to high-dose-rate (HDR) skin brachytherapy using VLSAs to ensure safety and quality. A multidisciplinary team created a protocol for HDR VLSA skin treatments and applied FMEA. Failure modes were identified and scored by severity, occurrence, and detectability. The clinical procedure was then revised to address high-scoring process nodes. Several key components were added to the protocol to minimize risk probability numbers. (1) Diagnosis, prescription, applicator selection, and setup are reviewed at weekly quality assurance rounds. Peer review reduces the likelihood of an inappropriate treatment regime. (2) A template for HDR skin treatments was established in the clinic's electronic medical record system to standardize treatment instructions. This reduces the chances of miscommunication between the physician and planner as well as increases the detectability of an error. (3) A screen check was implemented during the second check to increase detectability of an error. (4) To reduce error probability, the treatment plan worksheet was designed to display plan parameters in a format visually similar to the treatment console display, facilitating data entry and verification. (5) VLSAs are color coded and labeled to match the electronic medical record prescriptions, simplifying in-room selection and verification. Multidisciplinary planning and FMEA increased detectability and reduced error probability during VLSA HDR brachytherapy. This clinical model may be useful to institutions implementing similar procedures. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  10. High reliability level on single-mode 980nm-1060 nm diode lasers for telecommunication and industrial applications

    NASA Astrophysics Data System (ADS)

    Van de Casteele, J.; Bettiati, M.; Laruelle, F.; Cargemel, V.; Pagnod-Rossiaux, P.; Garabedian, P.; Raymond, L.; Laffitte, D.; Fromy, S.; Chambonnet, D.; Hirtz, J. P.

    2008-02-01

    We demonstrate very high reliability level on 980-1060nm high-power single-mode lasers through multi-cell tests. First, we show how our chip design and technology enables high reliability levels. Then, we aged 758 devices during 9500 hours among 6 cells with high current (0.8A-1.2A) and high submount temperature (65°C-105°C) for the reliability demonstration. Sudden catastrophic failure is the main degradation mechanism observed. A statistical failure rate model gives an Arrhenius thermal activation energy of 0.51eV and a power law forward current acceleration factor of 5.9. For high-power submarine applications (360mW pump module output optical power), this model exhibits a failure rate as low as 9 FIT at 13°C, while ultra-high power terrestrial modules (600mW) lie below 220 FIT at 25°C. Wear-out phenomena is observed only for very high current level without any reliability impact under 1.1A. For the 1060nm chip, step-stress tests were performed and a set of devices were aged during more than 2000 hours in different stress conditions. First results are in accordance with 980nm product with more than 100khours estimated MTTF. These reliability and performance features of 980-1060nm laser diodes will make high-power single-mode emitters the best choice for a number of telecommunication and industrial applications in the next few years.

  11. Fast synchronization algorithms of burst-mode 16 QAM receiver for video-on-demand applications

    NASA Astrophysics Data System (ADS)

    Wang, Xiaohua; Codenie, Jan; Qiu, Xing-Zhi; Everaert, Alain; Vandewege, Jan; De Meyer, Karel; Trog, Willy; De Vleeschouwer, A.; Marin, W.

    1997-10-01

    This paper describes a novel TDMA/FDMA combined 16 QAM receiver architecture developed for video-on-demand applications. A burst-operated rapid synchronization scheme is proposed which employs an efficient training preamble for overlapped operation of automatic gain control, carrier phase acquisition and symbol timing alignment. All the dedicated synchronization algorithms are digitally implemented, using field programmable gate arrays (FPGA), for a data rate of 10.8 Mbit/s. Several analytic relationships for control accuracy, acquisition time and signal to noise ratio (S/N) are derived. Experimental results demonstrate that the proposed method significantly decreases the required preamble length to 23 symbols, together with a dynamic range of 11 dB and a sensitivity of minus 56 dBm for a bit-error-rate (BER) of 5 * 10-9. The BER performance with frequency offset and input power variation is also investigated.

  12. 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.

  13. Modes of log gravity

    SciTech Connect

    Bergshoeff, Eric A.; Rosseel, Jan; Hohm, Olaf; Townsend, Paul K.

    2011-05-15

    The physical modes of a recently proposed D-dimensional 'critical gravity', linearized about its anti-de Sitter vacuum, are investigated. All 'log mode' solutions, which we categorize as 'spin-2' or 'Proca', arise as limits of the massive spin-2 modes of the noncritical theory. The linearized Einstein tensor of a spin-2 log mode is itself a 'nongauge' solution of the linearized Einstein equations whereas the linearized Einstein tensor of a Proca mode takes the form of a linearized general coordinate transformation. Our results suggest the existence of a holographically dual logarithmic conformal field theory.

  14. [Effects of irrigation mode and N application rate on cotton field fertilizer N use efficiency and N losses].

    PubMed

    Wang, Xiao-Juan; Wei, Chang-Zhou; Zhang, Jun; Dong, Peng; Wang, Juan; Zhu, Qi-Chao; Wang, Jin-Xin

    2012-10-01

    A field experiment was conducted to study the effects of different irrigation modes (drip irrigation and furrow irrigation) and different N application rates (0, 240, 360 and 480 kg N x hm(-2)) on the fertilizer N use efficiency and N losses in a cotton field in Xinjiang, Northwest China. The main N cycling pathways, such as the N uptake by cotton plant, NO3(-)-N residual in soil, NH3 volatilization, NO3(-)-N leaching, and nitrification-denitrification, were quantitatively monitored. Compared with furrow irrigation, drip irrigation increased the seed cotton yield, plant N uptake, and fertilizer N use efficiency significantly. The NO3(-)-N residual in soil was significantly greater under furrow irrigation than under drip irrigation. With the application of fertilizer N, the N loss from NH3 volatilization under drip irrigation occupied 0.06% -0.14% of applied N, and was significantly greater than that under furrow irrigation. The N loss from NO3(-)-N leaching under drip irrigation and furrow irrigation was 4.4% and 8.8% of the applied N, respectively. Compared with furrow irrigation, drip irrigation could significantly decrease the NO3(-)-N leakage rate in leakage water. The nitrification-dinetrification loss under drip irrigation and furrow irrigation was 17.9% and 16.8% of the applied N, respectively. It was suggested that NO3(-)-N leaching and nitrification-denitrification were the main N losses in the cotton fields of Xinjiang.

  15. 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

  16. Dual-Mode Electro-Optical Techniques for Biosensing Applications: A Review

    PubMed Central

    Johnson, Steven

    2017-01-01

    The monitoring of biomolecular interactions is a key requirement for the study of complex biological processes and the diagnosis of disease. Technologies that are capable of providing label-free, real-time insight into these interactions are of great value for the scientific and clinical communities. Greater understanding of biomolecular interactions alongside increased detection accuracy can be achieved using technology that can provide parallel information about multiple parameters of a single biomolecular process. For example, electro-optical techniques combine optical and electrochemical information to provide more accurate and detailed measurements that provide unique insights into molecular structure and function. Here, we present a comparison of the main methods for electro-optical biosensing, namely, electrochemical surface plasmon resonance (EC-SPR), electrochemical optical waveguide lightmode spectroscopy (EC-OWLS), and the recently reported silicon-based electrophotonic approach. The comparison considers different application spaces, such as the detection of low concentrations of biomolecules, integration, the tailoring of light-matter interaction for the understanding of biomolecular processes, and 2D imaging of biointeractions on a surface. PMID:28880211

  17. 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.

  18. Dual-Mode Electro-Optical Techniques for Biosensing Applications: A Review.

    PubMed

    Juan-Colás, José; Johnson, Steven; Krauss, Thomas F

    2017-09-07

    The monitoring of biomolecular interactions is a key requirement for the study of complex biological processes and the diagnosis of disease. Technologies that are capable of providing label-free, real-time insight into these interactions are of great value for the scientific and clinical communities. Greater understanding of biomolecular interactions alongside increased detection accuracy can be achieved using technology that can provide parallel information about multiple parameters of a single biomolecular process. For example, electro-optical techniques combine optical and electrochemical information to provide more accurate and detailed measurements that provide unique insights into molecular structure and function. Here, we present a comparison of the main methods for electro-optical biosensing, namely, electrochemical surface plasmon resonance (EC-SPR), electrochemical optical waveguide lightmode spectroscopy (EC-OWLS), and the recently reported silicon-based electrophotonic approach. The comparison considers different application spaces, such as the detection of low concentrations of biomolecules, integration, the tailoring of light-matter interaction for the understanding of biomolecular processes, and 2D imaging of biointeractions on a surface.

  19. Characterization of continuous and pulsed emission modes of a hybrid micro focus x-ray source for medical imaging applications

    NASA Astrophysics Data System (ADS)

    Ghani, Muhammad U.; Wong, Molly D.; Ren, Liqiang; Wu, Di; Zheng, Bin; Rong, John. X.; Wu, Xizeng; Liu, Hong

    2017-05-01

    The aim of this study was to quantitatively characterize a micro focus x-ray tube that can operate in both continuous and pulsed emission modes. The micro focus x-ray source (Model L9181-06, Hamamatsu Photonics, Japan) has a varying focal spot size ranging from 16 μm to 50 μm as the source output power changes from 10 to 39 W. We measured the source output, beam quality, focal spot sizes, kV accuracy, spectra shapes and spatial resolution. Source output was measured using an ionization chamber for various tube voltages (kVs) with varying current (μA) and distances. The beam quality was measured in terms of half value layer (HVL), kV accuracy was measured with a non-invasive kV meter, and the spectra was measured using a compact integrated spectrometer system. The focal spot sizes were measured using a slit method with a CCD detector with a pixel pitch of 22 μm. The spatial resolution was quantitatively measured using the slit method with a CMOS flat panel detector with a 50 μm pixel pitch, and compared to the qualitative results obtained by imaging a contrast bar pattern. The focal spot sizes in the vertical direction were smaller than that of the horizontal direction, the impact of which was visible when comparing the spatial resolution values. Our analyses revealed that both emission modes yield comparable imaging performances in terms of beam quality, spectra shape and spatial resolution effects. There were no significantly large differences, thus providing the motivation for future studies to design and develop stable and robust cone beam imaging systems for various diagnostic applications.

  20. Application of Diol column under adsorption and mixed partition-adsorption normal-phase liquid chromatography mode for the separation of purines and pyrimidines.

    PubMed

    Kazoka, H

    2008-05-02

    The diol-bonded phase (column LiChrospher 100 Diol) has been studied for the separation of some purines and pyrimidines under normal-phase liquid chromatography (NPLC) conditions. Retention time, column efficiency, and selectivity of column with diol-phase were compared to those of unmodified silica (column LiChrospher SI-60). It was established that under adsorption NPLC mode application of diol-phase can reduce the separation time and a little improve the column efficiency. Significant improvement of the column efficiency for polar solutes is observed if mixed partition-adsorption NPLC mode is used. The investigation has shown that application of diol-phase instead of bare silica is useful not only under adsorption, but also under mixed partition-adsorption mode if the system with specific selectivity is necessary.

  1. A fast macroblock mode decision scheme using ROI-based coding of H.264/MPEG-4 Part 10 AVC for mobile video telephony applications

    NASA Astrophysics Data System (ADS)

    Na, Taeyoung; Lee, Yousun; Lim, Jeongyeon; Joo, Yongho; Kim, Kimoon; Byun, Jaewan; Kim, Munchurl

    2008-08-01

    We propose a fast macroblock mode decision scheme in the H.264|MPEG-4 Part 10 Advanced Video Coding (AVC) for mobile video telephony applications. In general, the face region around a speaker is considered region of interest (ROI) while the background is not importantly considered, thus being regarded as non-ROI for the video telephony situations. We usually have to consider the following two issues: (1) the platforms of mobile video telephony are usually computationally limited and the AVC codecs are computationally expensive; and (2) the allowed channel bandwidths are usually very small so the compressed video streams are transmitted with visual quality degraded. In this paper, we challenge the two issues: Firstly, a fast macroblock mode decision scheme is contrived to alleviate the computational complexity of H.264|MPEG-4 Part 10 AVC; and secondly, ROI/non-ROI coding of H.264|MPEG-4 Part 10 AVC is incorporated to enhance subjective visual quality by encoding ROI data in higher quality but non-ROI data in lower quality. Our proposed fast macroblock mode decision scheme consists of three parts: early skip mode detection, fast inter macroblock mode decision and intra prediction skip parts. The skip mode detection method is to decide whether or not to perform the rest inter macroblock modes in P-Slices. The fast inter macroblock mode method is to reduce the candidate block mode by SATDMOTION from 16x16 and 8x8 block motion estimation. The intra prediction skipping condition is set to decide whether or not to perform the 4x4 intra prediction in P-Slices using the relation between magnitude of the motion vectors of the current macroblock and the occurrence frequencies of intra predicted macroblocks. The experimental results show that the proposed scheme yields up to 51.88% of the computational complexity reduction in total encoding time with negligible amounts of PSNR drops and bit rate increments, respectively.

  2. 40 CFR 63.5798 - What if I want to use, or I manufacture, an application technology (new or existing) whose...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... represented by the equations in Table 1 to this subpart? 63.5798 Section 63.5798 Protection of Environment... technology (new or existing) whose organic HAP emissions characteristics are not represented by the equations... existing), whose emission characteristics are not represented by the equations in Table 1 to this...

  3. A pre-clinical phantom comparison of tissue harmonic and brightness mode imaging for application in ultrasound guided prostate brachytherapy.

    PubMed

    Sandhu, G K; Dunscombe, P B; Khan, R F H

    2011-07-01

    The current practice of prostate brachytherapy utilizes the brightness (B) mode ultrasound imaging for volume definition and needle guidance. However, tissue harmonic (H) mode available with new scanners has shown the improved image quality. The aim of this study was to perform a pre-clinical phantom evaluation of harmonic imaging as an alternative to B mode in prostate brachytherapy. Performance characteristics viz. dead zone, depth of penetration, geometric accuracy, spatial resolution, tissue to clutter ratio (TCR) and signal to noise ratio (SNR), were compared between two modes using an in-house phantom. Images were acquired under the same settings except the gain; which is higher for the H mode than that of B mode. A qualitative comparison between two modes was also performed using commercial CIRS053 phantom. Dead zone, depth of penetration and geometric accuracy were respectively <1 mm, >8 cm and <1% for both modes. Relative TCR, SNR and the spatial resolution were improved in H mode compared with B mode. Images with CIRS053 phantom in H mode demonstrate sharper boundaries for prostate and urethra, freedom from background clutter, and better identification of the brachytherapy needles. This study indicates the superiority of H over B mode, in terms of spatial resolution, relative contrast, and overall image quality. Thus H mode has the potential benefit in prostate brachytherapy. This study provides the basis to move forward to investigate whether the superior image quality observed in the laboratory can be translated into a higher treatment quality for the patient. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

  4. Mode conversion of Langmuir to electromagnetic waves at magnetic field-aligned density inhomogeneities: Simulations, theory, and applications to the solar wind and the corona

    SciTech Connect

    Kim, Eun-Hwa; Cairns, Iver H.; Robinson, Peter A.

    2008-10-15

    experimental quantities, and generalize easily for wave packets. The total energy conversion efficiency differs from the power conversion efficiency by the ratio of the group speeds for each mode, is less than 10% for the value of {beta}=0.01 simulated, and decreases linearly with {beta}. Since {beta}{approx_equal}10{sup -5}-10{sup -4} in the solar wind and corona, this {beta} dependence is important in applications. (7) The interference effect and the disappearance of the x mode at {omega}(greater-or-similar sign)1 can be accounted for semiquantitatively using a WKB-type analysis. (8) Constraints on density turbulence are developed for the x mode to be generated and be able to propagate from the source. (9) Standard parameters for the corona and the solar wind near 1 AU suggest that linear mode conversion should produce both o- and x-mode radiation for solar and interplanetary radio bursts. It is therefore possible that linear mode conversion under these conditions might explain the weak total circular polarizations of type II and III solar radio bursts.

  5. Transmission mode adaptive beamforming for planar phased arrays and its application to 3D ultrasonic transcranial imaging

    NASA Astrophysics Data System (ADS)

    Shapoori, Kiyanoosh; Sadler, Jeffrey; Wydra, Adrian; Malyarenko, Eugene; Sinclair, Anthony; Maev, Roman G.

    2013-03-01

    A new adaptive beamforming method for accurately focusing ultrasound behind highly scattering layers of human skull and its application to 3D transcranial imaging via small-aperture planar phased arrays are reported. Due to its undulating, inhomogeneous, porous, and highly attenuative structure, human skull bone severely distorts ultrasonic beams produced by conventional focusing methods in both imaging and therapeutic applications. Strong acoustical mismatch between the skull and brain tissues, in addition to the skull's undulating topology across the active area of a planar ultrasonic probe, could cause multiple reflections and unpredictable refraction during beamforming and imaging processes. Such effects could significantly deflect the probe's beam from the intended focal point. Presented here is a theoretical basis and simulation results of an adaptive beamforming method that compensates for the latter effects in transmission mode, accompanied by experimental verification. The probe is a custom-designed 2 MHz, 256-element matrix array with 0.45 mm element size and 0.1mm kerf. Through its small footprint, it is possible to accurately measure the profile of the skull segment in contact with the probe and feed the results into our ray tracing program. The latter calculates the new time delay patterns adapted to the geometrical and acoustical properties of the skull phantom segment in contact with the probe. The time delay patterns correct for the refraction at the skull-brain boundary and bring the distorted beam back to its intended focus. The algorithms were implemented on the ultrasound open-platform ULA-OP (developed at the University of Florence).

  6. 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.

  7. Polarization multiplexing in large-mode-area waveguides and its application to signal enhancement in multiphoton microscopy

    NASA Astrophysics Data System (ADS)

    He, Jiexing; Wang, Yuxin; Wen, Wenhui; Wang, Kai; Liu, Hongji; Qiu, Ping; Wang, Ke

    2017-01-01

    Soliton self-frequency shift (SSFS) is an efficient technique of generating broadband tunable femtosecond optical pulses. By using large-mode-area (LMA) waveguides such as photonic-crystal (PC) rods or LMA fibers, SSFS is capable of generating solitons with tens of or even >100 nJ pulse energy, enabling deep-tissue multiphoton microscopy (MPM) with the unprecedented imaging depth. MPM signals are proportional to the repetition rate of the laser. Here, we demonstrate an efficient technique of enhancing MPM signals in LMA waveguides, through polarization multiplexing, in both a PC rod with no polarization-maintaining (PM) structure and a PM LMA fiber. The collinear output soliton pulses with orthogonal linear polarizations show similar pulse energy, pulse width, and spectrum. We also demonstrate the application of this polarization multiplexing technique to MPM signal enhancement in biological tissues. Compared with single-polarization soliton excitation, excitation with polarization-multiplexed solitons can efficiently boost MPM signals in different modalities of MPM.

  8. Deflection of a viscoelastic cantilever under a uniform surface stress: Applications to static-mode microcantilever sensors undergoing adsorption

    NASA Astrophysics Data System (ADS)

    Wenzel, M. J.; Josse, F.; Heinrich, S. M.

    2009-03-01

    The equation governing the curvature of a viscoelastic microcantilever beam loaded with a uniform surface stress is derived. The present model is applicable to static-mode microcantilever sensors made with a rigid polymer, such as SU-8. An analytical solution to the differential equation governing the curvature is given for a specific surface stress representing adsorption of analyte onto the viscoelastic beam's surface. The solution for the bending of the microcantilever shows that, in many cases, the use of Stoney's equation to analyze stress-induced deflection of viscoelastic microcantilevers (in the present case due to surface analyte adsorption) can lead to poor predictions of the beam's response. It is shown that using a viscoelastic substrate can greatly increase sensitivity (due to a lower modulus), but at the cost of a longer response time due to viscoelastic creep in the microcantilever. In addition, the effects of a coating on the cantilever are considered. By defining effective moduli for the coated-beam case, the analytical solution for the uncoated case can still be used. It is found that, unlike the case of a silicon microcantilever, the stress in the coating due to bending of a polymer cantilever can be significant, especially for metal coatings. The theoretical results presented here can also be used to extract time-domain viscoelastic properties of the polymer material from beam response data.

  9. Passive single-mode wavelength division (de)multiplexers for short-link multiwavelength applications in field environments

    NASA Astrophysics Data System (ADS)

    Deng, Xuegong; Zhao, Feng; Zou, Jizuo; Chen, Ray T.; Morey, William W.; Horwitz, James W.; Villavicencio, Victor I.; Chang, George; Collins, Ray

    2001-04-01

    We construct a passive grating-based wavelength-division (de)multiplexer (MUX/DMUX) for single-mode-fiber networks. The MUX/DMUX has almost identical bi-directional filtering characteristics on optical signals at wavelengths around 1550 nm. With total insertion loss less than 3 dB and an enlarged passing band of each channel, the encapsulated device exhibits very stable performance under temperature variation and is immune from mechanical vibration. The insertion loss of this device changes about 1 dB at temperatures from 25 degree(s)C to 60 degree(s)C, while the enter wavelength of each channel drifts about 8.3 X 10-4 nm/(nm(DOT) degree(s)C). Better results are expected with further optimization on the design. The device successfully demultiplexes 231 -1 PRBS signals up to 3.5 Gb/s per channel in an emulated amplifier-free local- area networks (LAN's) and metropolitan-area networks transmission. It is plausible the cost-effective MUX/DEMUX is an excellent candidate to meet 10 Gb/s all-optical multi- wavelength short-link applications.

  10. 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.

  11. 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.

  12. 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.

    2014-03-01

    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 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 datasets collected on research vessels by NOAA PMEL, 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.

  13. Molecular mechanics force field-based map for peptide amide-I mode in solution and its application to alanine di- and tripeptides.

    PubMed

    Cai, Kaicong; Han, Chen; Wang, Jianping

    2009-10-28

    A molecular mechanics (MM) force field-based empirical electrostatic potential map (MM map) for amide-I vibrations is developed with the aim of seeking a quick and reasonable approach to computing local mode parameters and their distributions in solution phase. Using N-methylacetamide (NMA) as a model compound, the instantaneous amide-I normal-mode parameters (transition frequency and dipole) obtained at the level of MM force fields are converted to solution phase values by a four-site potential scheme, but without the need for quantum mechanical frequency computations of solute-solvent clusters as are required in constructing ab initio-based electrostatic potential or field maps. The linear IR line shape of the amide-I mode in NMA obtained from the frequency-time correlation function on the basis of the MM map are found to be comparable to those from the ab initio-based maps. Our results show that the amide-I local mode parameters are largely determined by the solvated peptide structure rather than by explicit solvent molecules, suggesting an inherent local structure sensitivity of the amide-I mode in solvated peptides. Applications to alanine di- and tripeptides are satisfactorily demonstrated, showing its usefulness as an alternative approach in providing vibrational parameters for the simulation of linear IR and 2D IR spectra of the amide-I modes in polypeptides.

  14. Biochar application mode influences nitrogen leaching and NH3 volatilization losses in a rice paddy soil irrigated with N-rich wastewater.

    PubMed

    Sun, Haijun; Min, Ju; Zhang, Hailin; Feng, Yanfang; Lu, Kouping; Shi, Weiming; Yu, Min; Li, Xuewen

    2017-07-11

    Impacts of biochar application mode on nitrogen (N) leaching, ammonia (NH3) volatilization, rice grain yield and N use efficiency (NUE) are not well understood. Therefore, a field experiment was conducted to evaluate those impacts in a rice paddy soil received 225 kg N ha(-1) from either urea or N-rich wastewater. One treatment received 10 t ha(-1) biochar with the basal fertilization, and the other received same total amount of biochar but split applied with the three split N applications with same ratio as N fertilizer split ratio (40%, 30% and 30%). Results showed that N leaching loads were 4.20-6.22 kg ha(-1). Biochar one-time application reduced N leaching by 23.1%, and biochar split application further reduced N leaching by 32.4%. Total NH3 volatilization loss was 15.5-24.5 kg ha(-1). Biochar one-time application did not influence the NH3 volatilization, but biochar split application stimulated the cumulative NH3 volatilization by 57.7%. Both biochar treatments had no influence on NUE and rice grain yield. In conclusion, biochar application mode indeed influences the N leaching and NH3 volatilization in rice paddy soils, and biochar one-time application should be recommended for reducing N leaching without increasing NH3 volatilization.

  15. Loading Mode Optimization and Structure Tailoring in Spark Plasma Sintering of Monocarbide Powder-based Components for High Temperature Applications

    NASA Astrophysics Data System (ADS)

    Wei, Xialu

    In this study, the spark plasma sintering (SPS) is employed to consolidate poorly sinter-able ultra-high temperature ceramic (UHTC) powders due to the fact that the conjoint application of electric current and mechanical pressure during SPS can largely offset the required processing temperature. Zirconium carbide (ZrC) is selected as target material as it broadly represents properties of typical UHTCs. Investigations on SPS of ZrC are concurrently conducted in two correlated regimes: One regime is used to optimize the SPS densification efficiency by manipulating the loading schematics. The other regime is used to produce complex shape carbide components for high temperature applications via SPS. Both theoretical and experimental studies are involved in the achievement of the formulated research objectives. Consolidation of ZrC has been carried out to form a densification map with determining the optimal processing parameters. The densification of ZrC is studied through the continuum theory of sintering, in which the ZrC power-law creep parameters have been determined through the clarification of electrical and thermal aspects of the employed SPS system. Then the SPS-forging setup is proposed as it is theoretically and experimentally proven to be able to render more densification than the regular SPS. SPS-forging and regular SPS are eventually integrated into a hybrid loading mode SPS regime to combine the advantages of the individual setups to obtain the optimal densification kinetics. Annular shape ZrC pellets have been fabricated using SPS. Finite element modeling framework is constructed to manifest the thermomechanical interactions during the SPS of annular shape ZrC specimens. The fabrication procedures are practically adapted to produce also annular shape carbide composites with excellent high temperature structural strength being used as alternative SPS tooling components. The applicability of annular shape fuel pellet to accommodate volume swelling under

  16. Greening Existing Tribal Buildings

    EPA Pesticide Factsheets

    Guidance about improving sustainability in existing tribal casinos and manufactured homes. Many steps can be taken to make existing buildings greener and healthier. They may also reduce utility and medical costs.

  17. Contrastive analysis of three parallel modes in multi-dimensional dynamic programming and its application in cascade reservoirs operation

    NASA Astrophysics Data System (ADS)

    Zhang, Yanke; Jiang, Zhiqiang; Ji, Changming; Sun, Ping

    2015-10-01

    The "curse of dimensionality" of dynamic programming (DP) has always been a great challenge to the cascade reservoirs operation optimization (CROO) because computer memory and computational time increase exponentially with the increasing number of reservoirs. It is an effective measure to combine DP with the parallel processing technology to improve the performance. This paper proposes three parallel modes for multi-dimensional dynamic programming (MDP) based on .NET4 Parallel Extensions, i.e., the stages parallel mode, state combinations parallel mode and hybrid parallel mode. A cascade reservoirs of Li Xiangjiang River in China is used as the study instance in this paper, and a detailed contrastive analysis of the three parallel modes on run-time, parallel acceleration ratio, parallel efficiency and memory usage has been implemented based on the parallel computing results. Results show that all the three parallel modes can effectively shorten the run-time so that to alleviate the "curse of dimensionality" of MDP, but relatively, the state combinations parallel mode is the optimal, the hybrid parallel is suboptimal and the stages parallel mode is poor.

  18. High-resolution microwave-photonic applications via precise synchronization between RF and mode-locked laser pulses (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Shi, Kebin; Lu, Xing; Lv, Zhiqiang

    2016-10-01

    Precise synchronization between radio frequency and mode-locked laser pulses provides a high resolution capability for detecting either time jitter in laser pulse train or phase noise in radio frequency. In this talk, we will present our recent progresses on radio frequency dissemination and fiber optical sensing based on sub-femtosecond level synchronization between radio frequency and mode-locked pulse train.

  19. 40 CFR 63.5798 - What if I want to use, or I manufacture, an application technology (new or existing) whose...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... in Table 1 to this subpart? If you wish to use a resin or gel coat application technology (new or.... This petition must contain a description of the resin or gel coat application technology and supporting... data should be obtained using a range of resin or gel coat HAP contents to demonstrate the...

  20. 40 CFR 63.5798 - What if I want to use, or I manufacture, an application technology (new or existing) whose...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... in Table 1 to this subpart? If you wish to use a resin or gel coat application technology (new or.... This petition must contain a description of the resin or gel coat application technology and supporting... data should be obtained using a range of resin or gel coat HAP contents to demonstrate the...

  1. Effects of whispering gallery mode in microsphere super-resolution imaging

    NASA Astrophysics Data System (ADS)

    Zhou, Song; Deng, Yongbo; Zhou, Wenchao; Yu, Muxin; Urbach, H. P.; Wu, Yihui

    2017-09-01

    Whispering Gallery modes have been presented in microscopic glass spheres or toruses with many applications. In this paper, the possible approaches to enhance the imaging resolution by Whispering Gallery modes are discussed, including evanescent waves coupling, transformed and illustration by Whispering Gallery modes. It shows that the high-order scattering modes play the dominant role in the reconstructed virtual image when the Whispering Gallery modes exist. Furthermore, we find that the high image resolution of electric dipoles can be achieved, when the out-of-phase components exist from the illustration of Whispering Gallery modes. Those results of our simulation could contribute to the knowledge of microsphere-assisted super-resolution imaging and its potential applications.

  2. Single-Mode VCSELs

    NASA Astrophysics Data System (ADS)

    Larsson, Anders; Gustavsson, Johan S.

    The only active transverse mode in a truly single-mode VCSEL is the fundamental mode with a near Gaussian field distribution. A single-mode VCSEL produces a light beam of higher spectral purity, higher degree of coherence and lower divergence than a multimode VCSEL and the beam can be more precisely shaped and focused to a smaller spot. Such beam properties are required in many applications. In this chapter, after discussing applications of single-mode VCSELs, we introduce the basics of fields and modes in VCSELs and review designs implemented for single-mode emission from VCSELs in different materials and at different wavelengths. This includes VCSELs that are inherently single-mode as well as inherently multimode VCSELs where higher-order modes are suppressed by mode selective gain or loss. In each case we present the current state-of-the-art and discuss pros and cons. At the end, a specific example with experimental results is provided and, as a summary, the most promising designs based on current technologies are identified.

  3. 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

    ... test dates. 63.8(a)(1)-(a)(3), (b), (c)(1)-(c)(3), (c)(6)-(c)(8), (d), (e), (f)(1)-(f)(6), (g)(1)-(g)(4... reporting requirements Yes. 63.10(c)(1)-(6), (c)(9)-(15) Additional records for continuous monitoring... New and Existing Affected Sources Classified as Large Foundries 3 Table 3 to Subpart ZZZZZ of Part...

  4. 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.

  5. 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).

  6. Coupling of Vibrational Modes of Adsorbates: Application to Field Induced Shifts for CO and CN on Cu(100).

    DTIC Science & Technology

    1987-11-01

    lengths and vibrational frequencies for both chemisorbed CO and CN as a Stark effect. Chemical changes are shown to be small. Keywords: Chemisorption, Vibrational modes , Potential energy surface, Electrochemistry.

  7. Parametrizing the time variation of the `surface term' of stellar p-mode frequencies: application to helioseismic data

    NASA Astrophysics Data System (ADS)

    Howe, R.; Basu, S.; Davies, G. R.; Ball, W. H.; Chaplin, W. J.; Elsworth, Y.; Komm, R.

    2017-02-01

    The solar-cycle variation of acoustic mode frequencies has a frequency dependence related to the inverse mode inertia. The discrepancy between model predictions and measured oscillation frequencies for solar and solar-type stellar acoustic modes includes a significant frequency-dependent term known as the surface term, which is also related to the inverse mode inertia. We parametrize both the surface term and the frequency variations for low-degree solar data from Birmingham Solar-Oscillations Network (BiSON) and medium-degree data from the Global Oscillations Network Group (GONG) using the mode inertia together with cubic and inverse frequency terms. We find that for the central frequency of rotationally split multiplets, the cubic term dominates both the average surface term and the temporal variation, but for the medium-degree case, the inverse term improves the fit to the temporal variation. We also examine the variation of the even-order splitting coefficients for the medium-degree data and find that, as for the central frequency, the latitude-dependent frequency variation, which reflects the changing latitudinal distribution of magnetic activity over the solar cycle, can be described by the combination of a cubic and an inverse function of frequency scaled by inverse mode inertia. The results suggest that this simple parametrization could be used to assess the activity-related frequency variation in solar-like asteroseismic targets.

  8. 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...

  9. Adaptive Batch Mode Active Learning.

    PubMed

    Chakraborty, Shayok; Balasubramanian, Vineeth; Panchanathan, Sethuraman

    2015-08-01

    Active learning techniques have gained popularity to reduce human effort in labeling data instances for inducing a classifier. When faced with large amounts of unlabeled data, such algorithms automatically identify the exemplar and representative instances to be selected for manual annotation. More recently, there have been attempts toward a batch mode form of active learning, where a batch of data points is simultaneously selected from an unlabeled set. Real-world applications require adaptive approaches for batch selection in active learning, depending on the complexity of the data stream in question. However, the existing work in this field has primarily focused on static or heuristic batch size selection. In this paper, we propose two novel optimization-based frameworks for adaptive batch mode active learning (BMAL), where the batch size as well as the selection criteria are combined in a single formulation. We exploit gradient-descent-based optimization strategies as well as properties of submodular functions to derive the adaptive BMAL algorithms. The solution procedures have the same computational complexity as existing state-of-the-art static BMAL techniques. Our empirical results on the widely used VidTIMIT and the mobile biometric (MOBIO) data sets portray the efficacy of the proposed frameworks and also certify the potential of these approaches in being used for real-world biometric recognition applications.

  10. 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

  11. 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, 2013 CFR

    2013-07-01

    ....1 Applicability Yes. 63.2 Definitions Yes. 63.3 Units and abbreviations Yes. 63.4 Prohibited activities Yes. 63.5 Construction/reconstruction Yes. 63.6(a)-(g) Compliance with standards and maintenance requirements Yes. 63.6(h) Opacity and visible emissions standards Yes. 63.6(i)(i)-(j) Compliance extension and...

  12. 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, 2011 CFR

    2011-07-01

    ....1 Applicability Yes. 63.2 Definitions Yes. 63.3 Units and abbreviations Yes. 63.4 Prohibited activities Yes. 63.5 Construction/reconstruction Yes. 63.6(a)-(g) Compliance with standards and maintenance requirements Yes. 63.6(h) Opacity and visible emissions standards Yes. 63.6(i)(i)-(j) Compliance extension and...

  13. 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

    ....1 Applicability Yes. 63.2 Definitions Yes. 63.3 Units and abbreviations Yes. 63.4 Prohibited activities Yes. 63.5 Construction/reconstruction Yes. 63.6(a)-(g) Compliance with standards and maintenance requirements Yes. 63.6(h) Opacity and visible emissions standards Yes. 63.6(i)(i)-(j) Compliance extension and...

  14. 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, 2014 CFR

    2014-07-01

    ....1 Applicability Yes. 63.2 Definitions Yes. 63.3 Units and abbreviations Yes. 63.4 Prohibited activities Yes. 63.5 Construction/reconstruction Yes. 63.6(a)-(g) Compliance with standards and maintenance requirements Yes. 63.6(h) Opacity and visible emissions standards Yes. 63.6(i)(i)-(j) Compliance extension and...

  15. 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

    ... HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS GENERAL PROVISIONS Application § 188.05-3 New... valid certificate of inspection as an oceanographic research vessel on March 1, 1968. (c) Other vessels..., initially inspected and certificated as an oceanographic research vessel on or after March 1, 1968,...

  16. 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

    ... HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS GENERAL PROVISIONS Application § 188.05-3 New... valid certificate of inspection as an oceanographic research vessel on March 1, 1968. (c) Other vessels..., initially inspected and certificated as an oceanographic research vessel on or after March 1, 1968,...

  17. 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).

  18. The Application of Leaf Ultrasonic Resonance to Vitis vinifera L. Suggests the Existence of a Diurnal Osmotic Adjustment Subjected to Photosynthesis.

    PubMed

    Sancho-Knapik, Domingo; Medrano, Hipólito; Peguero-Pina, José J; Mencuccini, Maurizio; Fariñas, Maria D; Álvarez-Arenas, Tomás G; Gil-Pelegrín, Eustaquio

    2016-01-01

    The main objective of this study was to apply the air-coupled broad-band ultrasonic spectroscopy in attached transpiring leaves of Vitis vinifera L. to monitor changes in leaf water potential (Ψ) through the measurements of the standardized value of the resonant frequency associated with the maximum transmitance (f/fo). With this purpose, the response of grapevine to a drought stress period was investigated in terms of leaf water status, ultrasounds, gas exchange and sugar accumulation. Two strong correlations were obtained between f/fo and Ψ measured at predawn (pd) and at midday (md) with different slopes. This fact implied the existence of two values of Ψ for a given value of f/fo, which was taken as a sign that the ultrasonic technique was not directly related to the overall Ψ, but only to one of its components: the turgor pressure (P). The difference in Ψ at constant f/fo (δ) was found to be dependent on net CO2 assimilation (A) and might be used as a rough estimator of photosynthetic activity. It was then, the other main component of Ψ, osmotic potential (π), the one that may have lowered the values of md Ψ with respect to pd Ψ by the accumulation of sugars associated to net CO2 assimilation. This phenomenon suggests the existence of a diurnal osmotic adjustment in this species associated to sugars production in well-watered plants.

  19. The Application of Leaf Ultrasonic Resonance to Vitis vinifera L. Suggests the Existence of a Diurnal Osmotic Adjustment Subjected to Photosynthesis

    PubMed Central

    Sancho-Knapik, Domingo; Medrano, Hipólito; Peguero-Pina, José J.; Mencuccini, Maurizio; Fariñas, Maria D.; Álvarez-Arenas, Tomás G.; Gil-Pelegrín, Eustaquio

    2016-01-01

    The main objective of this study was to apply the air-coupled broad-band ultrasonic spectroscopy in attached transpiring leaves of Vitis vinifera L. to monitor changes in leaf water potential (Ψ) through the measurements of the standardized value of the resonant frequency associated with the maximum transmitance (f/fo). With this purpose, the response of grapevine to a drought stress period was investigated in terms of leaf water status, ultrasounds, gas exchange and sugar accumulation. Two strong correlations were obtained between f/fo and Ψ measured at predawn (pd) and at midday (md) with different slopes. This fact implied the existence of two values of Ψ for a given value of f/fo, which was taken as a sign that the ultrasonic technique was not directly related to the overall Ψ, but only to one of its components: the turgor pressure (P). The difference in Ψ at constant f/fo (δ) was found to be dependent on net CO2 assimilation (A) and might be used as a rough estimator of photosynthetic activity. It was then, the other main component of Ψ, osmotic potential (π), the one that may have lowered the values of md Ψ with respect to pd Ψ by the accumulation of sugars associated to net CO2 assimilation. This phenomenon suggests the existence of a diurnal osmotic adjustment in this species associated to sugars production in well-watered plants. PMID:27833626

  20. 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

  1. Selective excitation of high-order laser modes and its application to vortex array laser beam generation

    NASA Astrophysics Data System (ADS)

    Chu, Shu-Chun; Otsuka, Kenju

    2010-02-01

    This study reports a method of creating vortex array laser beams by superposing high-order laser modes on their rotated replicas. An interferometer configuration was used to convert these high-order laser modes to vortex array laser beams containing multi vortexes aligned in an almost square manner. To generate this kind vortex array laser beams, this study reports systematic approaches to the selective excitation of high-order laser modes in end-pumped solid-state lasers with laser resonators and asymmetric pumping. The resulting vortex array laser beams can be used as optical tweezers and atom traps in the form of two-dimensional arrays, or to study the transfer of angular momentum to micro particles or atoms (Bose-Einstein condensate).

  2. 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.

  3. 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.

  4. The methodology for the existing complex pneumatic systems efficiency increase with the use of mathematical modeling

    NASA Astrophysics Data System (ADS)

    Danilishin, A. M.; Kartashov, S. V.; Kozhukhov, Y. V.; Kozin, E. G.

    2017-08-01

    The method for the existing complex pneumatic systems efficiency increase has been developed, including the survey steps, mathematical technological process modeling, optimizing the pneumatic system configuration, its operation modes, selection of optimal compressor units and additional equipment. Practical application of the methodology is considered by the example of the existing pneumatic systems underground depot reconstruction. The first stage of the methodology is the survey of acting pneumatic system. The second stage of technique is multivariable mathematical modeling of the pneumatic system operation. The developed methodology is applicable to complex pneumatic systems.

  5. Fluoride - is it capable of fighting old and new dental diseases? An overview of existing fluoride compounds and their clinical applications.

    PubMed

    Brambilla, E

    2001-01-01

    Since researchers first became aware of the anticaries action of fluoride, they have been investigating the effect of this preventive agent in inhibiting or arresting caries development. Many forms of systemic or topical fluoride have been studied and tested for clinical application. Water, salt, milk fluoridation and the use of fluoride supplements were introduced for systemic fluoridation mainly using sodium fluoride. Solutions, gels, toothpastes and rinses of sodium fluoride, stannous fluoride, amine fluorides, acidulated phosphate fluoride and monofluorophosphate were used for topical fluoridation. More recently nonaqueous fluoride varnishes in an alcoholic solution of natural resins and difluorosilane agents in a polyurethane matrix were introduced. Although all of these fluoridation methods have a caries-preventive action, these benefits and the ease of application is variable. As fluoride is a key component of oral health promotion a coordinated approach on a community and individual basis seems to be needed to maximize the cost-benefit ratio of prevention.

  6. 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.

  7. Lamping process and application of ultra small U-shaped, whispery gallery mode (WGM) based optic fiber sensors

    NASA Astrophysics Data System (ADS)

    Chang, Yuan Cheng; Chiang, Chia Chin

    2015-07-01

    This study success to smaller and control the diameter of single mode optical fiber whispery gallery mode (WGM) to diameter 0.8 mm nonetching and nontaping treated. The sensitivity of this type ultra-small U-shape WGM strengthens neither etching nor taping fibre. The sensitivity we apply to thermo test depends on wavelength shift from 40 ~ 96°C (R2 = 0.99 ). The specially characteristics of the optical fiber could be tested for temperature, refraction, vibration, concussion, and CO2 detection.

  8. 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.

  9. 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.

  10. Partial Least-Squares Functional Mode Analysis: Application to the Membrane Proteins AQP1, Aqy1, and CLC-ec1

    PubMed Central

    Krivobokova, Tatyana; Briones, Rodolfo; Hub, Jochen S.; Munk, Axel; de Groot, Bert L.

    2012-01-01

    We introduce an approach based on the recently introduced functional mode analysis to identify collective modes of internal dynamics that maximally correlate to an external order parameter of functional interest. Input structural data can be either experimentally determined structure ensembles or simulated ensembles, such as molecular dynamics trajectories. Partial least-squares regression is shown to yield a robust solution to the multidimensional optimization problem, with a minimal and controllable risk of overfitting, as shown by extensive cross-validation. Several examples illustrate that the partial least-squares-based functional mode analysis successfully reveals the collective dynamics underlying the fluctuations in selected functional order parameters. Applications to T4 lysozyme, the Trp-cage, the aquaporin channels Aqy1 and hAQP1, and the CLC-ec1 chloride antiporter are presented in which the active site geometry, the hydrophobic solvent-accessible surface, channel gating dynamics, water permeability (pf), and a dihedral angle are defined as functional order parameters. The Aqy1 case reveals a gating mechanism that connects the inner channel gating residues with the protein surface, thereby providing an explanation of how the membrane may affect the channel. hAQP1 shows how the pf correlates with structural changes around the aromatic/arginine region of the pore. The CLC-ec1 application shows how local motions of the gating Glu148 couple to a collective motion that affects ion affinity in the pore. PMID:22947940

  11. Potential-based and non-potential-based cohesive zone formulations under mixed-mode separation and over-closure-Part II: Finite element applications

    NASA Astrophysics Data System (ADS)

    Máirtín, Éamonn Ó.; Parry, Guillaume; Beltz, Glenn E.; McGarry, J. Patrick

    2014-02-01

    does not correctly penalise mixed-mode over-closure at the stent-coating interface, significantly altering the stress state in the coating and preventing the prediction of buckling. Case study 3: Application of a displacement to the base of a bi-layered composite arch results in a symmetric sinusoidal distribution of normal and tangential traction at the arch interface. The traction defined mode mixity at the interface ranges from pure mode II at the base of the arch to pure mode I at the top of the arch. It is demonstrated that predicted debonding patterns are highly sensitive to normal-tangential coupling terms in a CZM. The NP2, XN, and BSG models exhibit a strong bias towards mode I separation at the top of the arch, while the NP1 model exhibits a bias towards mode II debonding at the base of the arch. Only the SMC model provides mode-independent behaviour in the early stages of debonding. This case study provides a practical example of the importance of the behaviour of CZMs under conditions of traction controlled mode mixity, following from the theoretical analysis presented in Part I of this study.

  12. 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.

  13. 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…

  14. 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.

  15. A comparative study between Empirical Wavelet Transforms and Empirical Mode Decomposition Methods: Application to bearing defect diagnosis

    NASA Astrophysics Data System (ADS)

    Kedadouche, M.; Thomas, M.; Tahan, A.

    2016-12-01

    The Ensemble Empirical Mode Decomposition (EEMD) is a noise assisted method that may sometimes provide a significant improvement on Empirical Mode Decomposition (EMD). However, the amplitude and number of added noise need to be selected when applying the EEMD method. Furthermore, the computation time which depends on the number of ensemble trails is very high compared to the EMD. In this paper, a new way for choosing the appropriate added noise is presented. Conversely, a recently-developed method called the Empirical Wavelet Transform (EWT) is investigated. A comparative study between the EMD and EWT methods is conducted. The results show that the EWT is better than the EEMD and EMD on mode estimates and computation time is significantly reduced. An experimental study on bearing diagnosis is conducted. The EWT is applied to experimental data coming from damaged bearings. In the paper, an index selection is introduced that allows for the automatic selection of the Intrinsic Mode Functions (IMF) that should be used to perform the envelope spectrum. It is shown that choosing all the IMF selected by the index is more efficient than only choosing the best one. The envelope of the sum of the selected IMF clearly reveals the bearing frequencies and its harmonics which are excited by the defect. This approach seems to be an effective and efficient method for processing bearing fault signals.

  16. Electromechanical imitator of antilock braking modes of wheels with pneumatic tire and its application for the runways friction coefficient measurement

    NASA Astrophysics Data System (ADS)

    Putov, A. V.; Kopichev, M. M.; Ignatiev, K. V.; Putov, V. V.; Stotckaia, A. D.

    2017-01-01

    In this paper it is considered a discussion of the technique that realizes a brand new method of runway friction coefficient measurement based upon the proposed principle of measuring wheel braking control for the imitation of antilock braking modes that are close to the real braking modes of the aircraft chassis while landing that are realized by the aircraft anti-skid systems. Also here is the description of the model of towed measuring device that realizes a new technique of runway friction coefficient measuring, based upon the measuring wheel braking control principle. For increasing the repeatability accuracy of electromechanical braking imitation system the sideslip (brake) adaptive control system is proposed. Based upon the Burkhard model and additive random processes several mathematical models were created that describes the friction coefficient arrangement along the airstrip with different qualitative adjectives. Computer models of friction coefficient measuring were designed and first in the world the research of correlation between the friction coefficient measuring results and shape variations, intensity and cycle frequency of the measuring wheel antilock braking modes. The sketch engineering documentation was designed and prototype of the latest generation measuring device is ready to use. The measuring device was tested on the autonomous electromechanical examination laboratory treadmill bench. The experiments approved effectiveness of method of imitation the antilock braking modes for solving the problem of correlation of the runway friction coefficient measuring.

  17. Docking studies on DNA-ligand interactions: building and application of a protocol to identify the binding mode.

    PubMed

    Ricci, Clarisse G; Netz, Paulo A

    2009-08-01

    Despite DNA being an important target for several drugs, most of the docking programs are validated only for proteins and their ligands. In this paper, we used AutoDock 4.0 to perform self-dockings and cross dockings between two DNA ligands (a minor groove binder and an intercalator) and four distinct receptors: 1) crystallographic DNA without intercalation gap; 2) crystallographic DNA with intercalation gap; 3) canonical B-DNA; and 4) modified B-DNA with intercalation gap. Besides being efficient in self-dockings, AutoDock is capable of correctly identifying two of the main DNA binding modes with the condition that the target possesses an artificial intercalation gap. Therefore, we suggest a default protocol to identify DNA binding modes which uses a modified canonical DNA (with gap) as receptor. This protocol was applied to dock two different Troger bases to DNA and the predicted binding modes agree with those suggested, yet not established, by experimental data. We also applied the protocol to dock aflatoxin B(1) exo-8,9-epoxide, and the results are in complete agreement with experimental data from the literature. We propose that this approach can be used to investigate other ligands whose binding mode to DNA remains unknown, yielding a suitable starting point for further theoretical studies such as molecular dynamics simulations.

  18. Large-scale parallel surface functionalization of goblet-type whispering gallery mode microcavity arrays for biosensing applications.

    PubMed

    Bog, Uwe; Brinkmann, Falko; Kalt, Heinz; Koos, Christian; Mappes, Timo; Hirtz, Michael; Fuchs, Harald; Köber, Sebastian

    2014-10-15

    A novel surface functionalization technique is presented for large-scale selective molecule deposition onto whispering gallery mode microgoblet cavities. The parallel technique allows damage-free individual functionalization of the cavities, arranged on-chip in densely packaged arrays. As the stamp pad a glass slide is utilized, bearing phospholipids with different functional head groups. Coated microcavities are characterized and demonstrated as biosensors.

  19. 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.

  20. 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.

  1. Summary and analysis of the currently existing literature data on metal-based nanoparticles published for selected aquatic organisms: Applicability for toxicity prediction by (Q)SARs.

    PubMed

    Chen, Guangchao; Vijver, Martina G; Peijnenburg, Willie J G M

    2015-09-01

    This review establishes an inventory of existing toxicity data on nanoparticles (NPs) with the purpose of developing (Quantitative) Structure-Activity Relationships for NPs (nano-[Q]SARs), and also of maximising the use of scientific sources for NP risk assessment. From a data search carried out on 27 February 2014, a total of 910 publications were retrieved from the Web of Science™ Core Collection, and a database comprising 886 records of toxicity endpoints, based on these publications, was built. The test organisms mainly comprised bacteria, algae, yeast, protozoa, nematoda, crustacea and fish. The NPs consisted mostly of metals, metal oxides, nanocomposites and quantum dots. The data were analysed further, in order to: a) categorise each toxicity endpoint and the biological effects triggered by the NPs; b) survey the characterisation of the NPs used; and c) assess whether the data were suitable for nano-(Q)SAR development. Despite the efforts of numerous scientific programmes on nanomaterial safety and design, our study concluded that lack of data consistency prevents the use of experimental data in developing and validating nano-(Q)SARs. Finally, an outlook on the future of nano-(Q)SAR development is provided.

  2. Correcting bias in self-rated quality of life: an application of anchoring vignettes and ordinal regression models to better understand QoL differences across commuting modes.

    PubMed

    Crane, Melanie; Rissel, Chris; Greaves, Stephen; Gebel, Klaus

    2016-02-01

    Likert scales are frequently used in public health research, but are subject to scale perception bias. This study sought to explore scale perception bias in quality-of-life (QoL) self-assessment and assess its relationships with commuting mode in the Sydney Travel and Health Study. Multilevel ordinal logistic regression analysis was used to analyse the association between two global QoL items about overall QoL and health satisfaction, with usual travel mode to work or study. Anchoring vignettes were applied using parametric and simpler nonparametric methods to detect and adjust for differences in reporting behaviour across age, sex, education, and income groups. The anchoring vignettes exposed differences in scale responses across demographic groups. After adjusting for these biases, public transport users (OR = 0.37, 95 % CI 0.21-0.65), walkers (OR = 0.44, 95 % CI 0.24-0.82), and motor vehicle users (OR = 0.47, 95 % CI 0.25-0.86) were all found to have lower odds of reporting high QoL compared with bicycle commuters. Similarly, the odds of reporting high health satisfaction were found to be proportionally lower amongst all competing travel modes: motor vehicle users (OR = 0.31, 95 % CI 0.18-0.56), public transport users (OR = 0.34, 95 % CI 0.20-0.57), and walkers (OR = 0.35, 95 % CI 0.20-0.64) when compared with cyclists. Fewer differences were observed in the unadjusted models. Application of the vignettes by the two approaches removed scaling biases, thereby improving the accuracy of the analyses of the associations between travel mode and quality of life. The adjusted results revealed higher quality of life in bicycle commuters compared with all other travel mode users.

  3. Suppression of mode-hop-induced optical signal deterioration in an external-cavity-diode laser with a fiber-Bragg grating for uncooled wavelength-division-multiplexing applications.

    PubMed

    Sato, Toshiya

    2003-06-20

    This paper reports on an external-cavity-diode laser (ECDL) employing a fiber Bragg grating, which was newly designed for WDM applications without temperature control. An optical signal waveform generated by the novel ECDL when the longitudinal lasing mode hopped was observed directly for the first time. It is confirmed that optical signal degradation caused by mode hopping can be suppressed effectively.

  4. 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

  5. Mode decomposition evolution equations.

    PubMed

    Wang, Yang; Wei, Guo-Wei; Yang, Siyang

    2012-03-01

    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

  6. 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…

  7. Relativity, Dimensionality, and Existence

    NASA Astrophysics Data System (ADS)

    Petkov, Vesselin

    A 100 years have passed since the advent of special relativity and 2008 will mark another important to all relativists anniversary - 100 years since Minkowski gave his talk "Space and Time" on September 21, 1908 in which he proposed the unifi- cation of space and time into an inseparable entity - space-time. Although special relativity has been an enormously successful physical theory no progress has been made in clarifying the question of existence of the objects represented by two of its basic concepts - space-time and world lines (or worldtubes in the case of extended bodies). The major reason for this failure appears to be the physicists' tradition to call such questions of existence philosophical. This tradition, however, is not quite consistent. In Newtonian mechanics physicists believe that they describe real objects whenever they talk about particles - one of the basic concepts of Newtonian physics. The situation is the same in quantum physics - no one questions the existence of electrons, protons, etc. Then why should the question of existence of worldtubes (representing particles in relativity) be regarded as a philosophical question?

  8. 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…

  9. 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.

  10. Enhancement of a whispering gallery mode microtoroid resonator by plasmonic triangular gold nanoprism for label-free biosensor applications

    NASA Astrophysics Data System (ADS)

    Nadgaran, H.; Afkhami Garaei, M.

    2015-07-01

    Whispering gallery mode microresonators coupled to plasmonic nanoparticles have shown great promise for ultra-sensitive and label-free biological sensing. We analyze a whispering gallery mode microtoroid biosensor with a triangular gold nanoprism bound to its surface. We choose triangular nanoprism because of its capability of considerable enhancement of electromagnetic field at the tips and because its localized surface plasmon resonance band position is readily tunable. The local electric field enhancement at different points of plasmonic triangular gold nanoprism is calculated and the effect of rounded tip is investigated. This field enhancement permits the detection and characterization of some large protein molecules. We have studied the detection of single bovine serum albumin protein using our hybrid microcavity.

  11. Application of a variation of empirical mode decomposition and Teager energy operator to EEG signals for mental task classification.

    PubMed

    Kaleem, M; Guergachi, A; Krishnan, S

    2013-01-01

    This paper presents a simple and effective methodology for mental task classification using a novel variation of the empirical mode decomposition (EMD) algorithm and the Teager energy operator applied to electroencephalography (EEG) signals. EEG signals corresponding to various types of mental tasks performed by human subjects are decomposed using the variation of EMD, called Empirical Mode Decomposition-Modified Peak Selection (EMD-MPS), which allows direct separation of the signals into a de-trended component, and a trend, according to a frequency separation criterion. Teager energy operator is then applied to calculate the average energy values of both components obtained after signal decomposition using EMD-MPS. These energy values are used to construct feature vectors, and one-versus-one classification of mental tasks is performed using a simple classifier, namely the 1-NN classifier. An average correct classification rate of 87% is obtained, improving on previous results and thereby also demonstrating the effectiveness of the methodology.

  12. 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).

  13. Robustly Single-mode Polarization Maintaining Er/Yb co-doped LMA Fiber for High Power Applications

    DTIC Science & Technology

    2007-05-08

    the fabrication of highly efficient, polarization maintaining ( PM ) LMA fibers. A PM - LMA Er/Yb co-doped fiber suitable for nanosecond pulsed...associated with fabricating LMA Er/Yb and Tm-doped fibers have previously been discussed in detail by Tankala et. al. [6]. In the case of a PM - LMA ...demonstrate a large core diameter PM Er/Yb fiber incorporating a unique raised inner-cladding which facilitates the use of conventional LMA mode selection

  14. Orbital-Angular-Momentum Mode Selection by Rotationally Symmetric Superposition of Chiral States with Application to Electron Vortex Beams

    NASA Astrophysics Data System (ADS)

    Yang, Yuanjie; Thirunavukkarasu, G.; Babiker, M.; Yuan, Jun

    2017-09-01

    A general orbital-angular-momentum (OAM) mode selection principle is put forward involving the rotationally symmetric superposition of chiral states. This principle is not only capable of explaining the operation of vortex generating elements such as spiral zone plate holograms, but more importantly, it enables the systematic and flexible generation of structured OAM waves in general. This is demonstrated both experimentally and theoretically in the context of electron vortex beams using rotationally symmetric binary amplitude chiral sieve masks.

  15. Single-mode optical fiber design with wide-band ultra low bending-loss for FTTH application.

    PubMed

    Watekar, Pramod R; Ju, Seongmin; Han, Won-Taek

    2008-01-21

    We propose a new design of a single-mode optical fiber (SMF) which exhibits ultra low bend sensitivity over a wide communication band (1.3 microm to 1.65 microm). A five-cladding fiber structure has been proposed to minimize the bending loss, estimated to be as low as 4.4x10(-10) dB/turn for the bend radius of 10 mm.

  16. Orbital-Angular-Momentum Mode Selection by Rotationally Symmetric Superposition of Chiral States with Application to Electron Vortex Beams.

    PubMed

    Yang, Yuanjie; Thirunavukkarasu, G; Babiker, M; Yuan, Jun

    2017-09-01

    A general orbital-angular-momentum (OAM) mode selection principle is put forward involving the rotationally symmetric superposition of chiral states. This principle is not only capable of explaining the operation of vortex generating elements such as spiral zone plate holograms, but more importantly, it enables the systematic and flexible generation of structured OAM waves in general. This is demonstrated both experimentally and theoretically in the context of electron vortex beams using rotationally symmetric binary amplitude chiral sieve masks.

  17. Trial of improved practices approach to explore the acceptability and feasibility of different modes of chlorhexidine application for neonatal cord care in Pemba, Tanzania.

    PubMed

    Dhingra, Usha; Sazawal, Sunil; Dhingra, Pratibha; Dutta, Arup; Ali, Said Mohammed; Ame, Shaali Makame; Deb, Saikat; Suleiman, Atifa Mohammed; Black, Robert E

    2015-12-28

    Infections are responsible for 30-40 % of 4 million neonatal deaths annually. Use of chlorhexidine (CHX), a broad-spectrum topical antiseptic with strong residual activity, for umbilical cord cleansing has been shown to reduce infections during the neonatal period. However, the challenge remains with regard to selection of best mode of CHX delivery. As a part of formative research, we undertook a qualitative study in Pemba Island as a pilot to explore the attitudes; beliefs and practices of the community and health workers related to delivery, newborn and cord care. During the second phase of formative research, we used Trials of Improved Practices (TIPs) methodology to explore the acceptance and impediments, for the three possible modes of chlorhexidine application- 100 ml bottle with cotton swab, 10 ml single use dropper bottle and 3 g single application squeeze tube containing gel, as an umbilical cord care intervention. In this pilot study, 204 mother-newborn pairs were enrolled from hospital and community setting in Pemba, Tanzania using a randomized three period crossover design. Mothers/guardians, Trained Birth Attendants (TBA)/ medical staff and community health workers (CHWs) were requested to try three different modes of CHX application for cord cleaning. All participants were demonstrated the method of cord cleaning using all three modes of delivery; each delivery mode was used for 3 days and an interview was conducted on day 10 to collect summary of their experience. Acceptance and preference scores were calculated based on feedback from the participants. Of 204 mother-newborn pairs, 27 were lost to follow up. 177 mothers performed the intervention and applied CHX to the newborn cord for all 9 days. Mothers rated 10 ml dropper bottle (49.7 %) as most convenient in terms of ease and application. They selected 10 ml dropper bottle (44.6 %) as their first choice; gel tube (33.9 %) and 100 ml bottle (21.5 %) as their second and third choice

  18. Phase diagram of interfacial growth modes by vapor deposition and its application for ZnO nanostructures

    NASA Astrophysics Data System (ADS)

    Shu, Da-Jun; Xiong, Xiang; Liu, Ming; Wang, Mu

    2017-09-01

    Interfacial growth from vapor has been extensively studied. However, a straightforward picture of the growth mode under different growth conditions is still lacking. In this paper, we develop a comprehensive interfacial growth theory based on the stochastic approach. Using a critical interisland separation, we construct a general phase diagram of the growth modes. It has been revealed that if the Ehrlich-Schwoebel barrier EES is smaller than a critical value, the interfacial growth proceeds in a layer-by-layer (LBL) mode at any deposition rate. However, if EES is larger than the critical value, LBL growth occurs only at very small or very large deposition rates relative to the intralayer hopping rate, and multilayer (ML) growth occurs at a moderate deposition rate. Experiments with zinc oxide growth by chemical vapor deposition have been designed to qualitatively demonstrate the theoretical model. By changing the flux of the carrier gas (nitrogen gas) in chemical vapor deposition, we realize LBL, ML, and then reentrance of LBL homoepitaxial growth of ZnO successively. Moreover, we find that surface kinetics of ZnO is suppressed by decreasing oxygen partial pressure by comparing the experimental observations and theoretical models, which is supported by our recent first-principles calculations. Since the influence of the substrate and the growth species on growth can approximately be represented by binding energy and surface kinetics, we suggest that the phase diagram is essential for interfacial growth of different materials by vapor deposition.

  19. 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.

  20. Quantum statistics for a two-mode magnon system with microwave pumping: application to coupled ferromagnetic nanowires

    NASA Astrophysics Data System (ADS)

    Haghshenasfard, Zahra; Cottam, M. G.

    2017-05-01

    A microscopic (Hamiltonian-based) method for the quantum statistics of bosonic excitations in a two-mode magnon system is developed. Both the exchange and the dipole-dipole interactions, as well as the Zeeman term for an external applied field, are included in the spin Hamiltonian, and the model also contains the nonlinear effects due to parallel pumping and four-magnon interactions. The quantization of spin operators is achieved through the Holstein-Primakoff formalism, and then a coherent magnon state representation is used to study the occupation magnon number and the quantum statistical behaviour of the system. Particular attention is given to the cross correlation between the two coupled magnon modes in a ferromagnetic nanowire geometry formed by two lines of spins. Manipulation of the collapse-and-revival phenomena for the temporal evolution of the magnon number as well as the control of the cross correlation between the two magnon modes is demonstrated by tuning the parallel pumping field amplitude. The role of the four-magnon interactions is particularly interesting and leads to anti-correlation in some cases with coherent states.

  1. Quantum statistics for a two-mode magnon system with microwave pumping: application to coupled ferromagnetic nanowires.

    PubMed

    Haghshenasfard, Zahra; Cottam, M G

    2017-05-17

    A microscopic (Hamiltonian-based) method for the quantum statistics of bosonic excitations in a two-mode magnon system is developed. Both the exchange and the dipole-dipole interactions, as well as the Zeeman term for an external applied field, are included in the spin Hamiltonian, and the model also contains the nonlinear effects due to parallel pumping and four-magnon interactions. The quantization of spin operators is achieved through the Holstein-Primakoff formalism, and then a coherent magnon state representation is used to study the occupation magnon number and the quantum statistical behaviour of the system. Particular attention is given to the cross correlation between the two coupled magnon modes in a ferromagnetic nanowire geometry formed by two lines of spins. Manipulation of the collapse-and-revival phenomena for the temporal evolution of the magnon number as well as the control of the cross correlation between the two magnon modes is demonstrated by tuning the parallel pumping field amplitude. The role of the four-magnon interactions is particularly interesting and leads to anti-correlation in some cases with coherent states.

  2. Multi-institutional application of Failure Mode and Effects Analysis (FMEA) to CyberKnife Stereotactic Body Radiation Therapy (SBRT).

    PubMed

    Veronese, Ivan; De Martin, Elena; Martinotti, Anna Stefania; Fumagalli, Maria Luisa; Vite, Cristina; Redaelli, Irene; Malatesta, Tiziana; Mancosu, Pietro; Beltramo, Giancarlo; Fariselli, Laura; Cantone, Marie Claire

    2015-06-13

    A multidisciplinary and multi-institutional working group applied the Failure Mode and Effects Analysis (FMEA) approach to assess the risks for patients undergoing Stereotactic Body Radiation Therapy (SBRT) treatments for lesions located in spine and liver in two CyberKnife® Centres. The various sub-processes characterizing the SBRT treatment were identified to generate the process trees of both the treatment planning and delivery phases. This analysis drove to the identification and subsequent scoring of the potential failure modes, together with their causes and effects, using the risk probability number (RPN) scoring system. Novel solutions aimed to increase patient safety were accordingly considered. The process-tree characterising the SBRT treatment planning stage was composed with a total of 48 sub-processes. Similarly, 42 sub-processes were identified in the stage of delivery to liver tumours and 30 in the stage of delivery to spine lesions. All the sub-processes were judged to be potentially prone to one or more failure modes. Nineteen failures (i.e. 5 in treatment planning stage, 5 in the delivery to liver lesions and 9 in the delivery to spine lesions) were considered of high concern in view of the high RPN and/or severity index value. The analysis of the potential failures, their causes and effects allowed to improve the safety strategies already adopted in the clinical practice with additional measures for optimizing quality management workflow and increasing patient safety.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. 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

    Masterson Creber, Ruth M; Maurer, Mathew S; Reading, Meghan; Hiraldo, Grenny; Hickey, Kathleen T; Iribarren, Sarah

    2016-06-14

    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. 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. 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. 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 for only 3 of the 34 apps. This review suggests

  10. 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

  11. The Problem of Existence

    DTIC Science & Technology

    1985-01-01

    envisionment ) produced by GIZMO . ? In the envisionment , I s indicates the set of quantity—conditioned individuals that exists during a situa- tion... envisionment step by step . In START, the initial state, GIZMO deduces that heat flow occurs, since there is assumed to be a temperature difference between the...stov e GIZMO implements the basic operations of qualitative process theory, including an envisioner for makin g predictions and a program for

  12. 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.

  13. 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.

  14. Majorana zero modes in a two-dimensional p -wave superconductor

    NASA Astrophysics Data System (ADS)

    Phong, Võ Tiến.; Walet, Niels R.; Guinea, Francisco

    2017-08-01

    We analyze the formation of Majorana zero modes at the edge of a two-dimensional topological superconductor. In particular, we study a time-reversal-invariant triplet phase that is likely to exist in doped Bi2Se3 . Upon the introduction of an in-plane magnetic field to the superconductor, a gap is opened in the surface modes, which induces localized Majorana modes. The position of these modes can be simply manipulated by changing the orientation of the applied field, yielding novel methods for braiding these states with possible applications to topological quantum computation.

  15. 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.

  16. Wide temperature range 0 < T < 85 °C narrow linewidth discrete mode laser diodes for coherent communications applications.

    PubMed

    O'Carroll, John; Phelan, Richard; Kelly, Brian; Byrne, Diarmuid; Barry, Liam P; O'Gorman, James

    2011-12-12

    Cost effective lasers meeting the linewidth requirements for coherent communication systems are a key element in reducing the overall cost of future coherent systems. We report on monolithic devices with linewidths as low as 138 kHz which operate in a narrow linewidth, single wavelength mode with high sidemode suppression ratio over a wide temperature tuning range of -10 °C < T < 110 °C. A linewidth variation of only 23 kHz was measured at a constant emitted power of 4 mW as the device temperature is varied in the range 0 °C < T < 85 °C. © 2011 Optical Society of America

  17. Synthesis, characterization, and application of a novel multifunctional stationary phase for hydrophilic interaction/reversed phase mixed-mode chromatography.

    PubMed

    Aral, Hayriye; Çelik, K Serdar; Altındağ, Ramazan; Aral, Tarık

    2017-11-01

    A novel multifunctional stationary phase based on silica gel was synthesised starting from L- isoleucine and 4-phenylbutylamine and evaluated as a hydrophilic interaction/reversed-phase mixed-mode stationary phase for high-performance liquid chromatography (HPLC). The prepared stationary phase was characterized by elemental analysis, infrared spectroscopy (IR), scanning electron microscopy (SEM), Brunauer, Emmett and Teller (BET) and solid-state (13)C nuclear magnetic resonance (NMR). The mechanisms involved in the chromatographic separation are multi-interaction, including hydrophobic, π-π, hydrogen-bonding, dipole-dipole and ion-dipole interactions. Based on these interactions, successful separation could be achieved among several aromatic compounds having different polarities under both hydrophilic interaction liquid chromatography (HILIC) and reversed phase (RP) condition. Nucleotides/nucleosides were separated in the HILIC mode. The effects of different separation conditions, such as pH value, mobile-phase content, column temperature, buffer concentration and flow rate, on the separation of nucleotides/nucleosides in HILIC mode were investigated. The seven nucleotides/nucleosides were separated within 22min, while six of them were separated within 10min by isocratic elution. To determine the influence of the new multifunctional stationary phase under the RP condition, a number of moderately and weakly polar and nonpolar compounds, such as 10 substituted anilines and eight substituted phenols were separated successfully under the RP condition within 14 and 15min, respectively. Additionally, nine mixtures of polar/nonpolar test compounds were simultaneously separated within 19min, while seven of them were separated within 12min, under HILIC/RP mixed-mode conditions. Chromatographic parameters, such as the retention factor and peak asymmetry factor, were calculated for all of the analytes, while the theoretical plate number was calculated for analytes separated

  18. Simultaneous spectral and temporal analyses of kinetic energies in nonequilibrium systems: theory and application to vibrational relaxation of O-D stretch mode of HOD in water.

    PubMed

    Jeon, Jonggu; Lim, Joon Hyung; Kim, Seongheun; Kim, Heejae; Cho, Minhaeng

    2015-05-28

    A time series of kinetic energies (KE) from classical molecular dynamics (MD) simulation contains fundamental information on system dynamics. It can also be analyzed in the frequency domain through Fourier transformation (FT) of velocity correlation functions, providing energy content of different spectral regions. By limiting the FT time span, we have previously shown that spectral resolution of KE evolution is possible in the nonequilibrium situations [Jeon and Cho, J. Chem. Phys. 2011, 135, 214504]. In this paper, we refine the method by employing the concept of instantaneous power spectra, extending it to reflect an instantaneous time-correlation of velocities with those in the future as well as with those in the past, and present a new method to obtain the instantaneous spectral density of KE (iKESD). This approach enables the simultaneous spectral and temporal resolution of KE with unlimited time precision. We discuss the formal and novel properties of the new iKESD approaches and how to optimize computational methods and determine parameters for practical applications. The method is specifically applied to the nonequilibrium MD simulation of vibrational relaxation of the OD stretch mode in a hydrated HOD molecule by employing a hybrid quantum mechanical/molecular mechanical (QM/MM) potential. We directly compare the computational results with the OD band population relaxation time profiles extracted from the IR pump-probe measurements for 5% HOD in water. The calculated iKESD yields the OD bond relaxation time scale ∼30% larger than the experimental value, and this decay is largely frequency-independent if the classical anharmonicity is accounted for. From the integrated iKESD over intra- and intermolecular bands, the major energy transfer pathways were found to involve the HOD bending mode in the subps range, then the internal modes of the solvent until 5 ps after excitation, and eventually the solvent intermolecular modes. Also, strong hydrogen

  19. Finding elementary flux modes in metabolic networks based on flux balance analysis and flux coupling analysis: application to the analysis of Escherichia coli metabolism.

    PubMed

    Tabe-Bordbar, Shayan; Marashi, Sayed-Amir

    2013-12-01

    Elementary modes (EMs) are steady-state metabolic flux vectors with minimal set of active reactions. Each EM corresponds to a metabolic pathway. Therefore, studying EMs is helpful for analyzing the production of biotechnologically important metabolites. However, memory requirements for computing EMs may hamper their applicability as, in most genome-scale metabolic models, no EM can be computed due to running out of memory. In this study, we present a method for computing randomly sampled EMs. In this approach, a network reduction algorithm is used for EM computation, which is based on flux balance-based methods. We show that this approach can be used to recover the EMs in the medium- and genome-scale metabolic network models, while the EMs are sampled in an unbiased way. The applicability of such results is shown by computing “estimated” control-effective flux values in Escherichia coli metabolic network.

  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.