WorldWideScience

Sample records for hybrid solitary structures

  1. Formation of lower-hybrid solitary structures by modulational interaction between lower-hybrid and dispersive Alfvén waves

    Directory of Open Access Journals (Sweden)

    J. O. Hall

    2009-03-01

    Full Text Available We investigate the possibility that lower-hybrid solitary structures (LHSS, which are frequently observed in the Earth's ionosphere and magnetosphere, are formed as a result of a modulational interaction between lower-hybrid and dispersive Alfvén waves of initially small amplitude. A large amplitude lower-hybrid pump wave can excite density structures with length scales transverse to the geomagnetic field of the order of the ion gyroradius via a modulational instability. The structure formation in the nonlinear stage of the instability is investigated by numerical solutions of the governing equations, using plasma parameters relevant for LHSS observations in the upper ionosphere and in the magnetosphere. The numerical solutions reveal that the lower-hybrid waves become self-localized inside cylindrically symmetric (with respect to the ambient magnetic field density cavities, in qualitative agreement with observations. Our model includes thermal electron effects but shows no stabilization at the ion sound gyroradius, suggesting that any preference of observed LHSS for that perpendicular scale likely is due to processes arresting the cavity collapse.

  2. Solitary structures with ion and electron thermal anisotropy

    CERN Document Server

    Khusroo, Murchana

    2015-01-01

    Formation of electrostatic solitary structures are analysed for a magnetised plasma with ion and electron thermal anisotropies. The ion thermal anisotropy is modelled with the help of the Chew-Goldberger-Low (CGL) double adiabatic equations of state while the electrons are treated as inertia-less species with an anisotropic bi-Maxwellian velocity distribution function. A negative electron thermal anisotropy $(T_{e\\perp}/T_e{\\parallel}>1)$ is found to help form large amplitude solitary structures which are in agreement with observational data.

  3. Observations of Solitary Structures in a Magnetized, Plasma Loaded Waveguide

    DEFF Research Database (Denmark)

    Lynov, Jens-Peter; Michelsen, Poul; Pécseli, Hans;

    1979-01-01

    Two types of solitary structure were investigated experimentally and numerically in a magnetized, plasma-loaded waveguide. One was identified as an ordinary KdV soliton and its properties were investigated with particular attention to the damping by resonant particles. The other type of pulse...

  4. Turing patterns and solitary structures under global control

    CERN Document Server

    Pismen, L M

    1994-01-01

    Striped Turing patterns and solitary band and disk structures are constructed using a three-variable multiscale model with cubic nonlinearity and global control. The existence and stability conditions of regular structures are analysed using the equation of motion of curved boundaries between alternative states of the short-range component. The combined picture of transitions between striped and spotted patterns with changing level of global control is in qualitative agreement with the results of the computer experiment by Middya and Luss

  5. Vlasov Simulation of Electrostatic Solitary Structures in Multi-Component Plasmas

    Science.gov (United States)

    Umeda, Takayuki; Ashour-Abdalla, Maha; Pickett, Jolene S.; Goldstein, Melvyn L.

    2012-01-01

    Electrostatic solitary structures have been observed in the Earth's magnetosheath by the Cluster spacecraft. Recent theoretical work has suggested that these solitary structures are modeled by electron acoustic solitary waves existing in a four-component plasma system consisting of core electrons, two counter-streaming electron beams, and one species of background ions. In this paper, the excitation of electron acoustic waves and the formation of solitary structures are studied by means of a one-dimensional electrostatic Vlasov simulation. The present result first shows that either electron acoustic solitary waves with negative potential or electron phase-space holes with positive potential are excited in four-component plasma systems. However, these electrostatic solitary structures have longer duration times and higher wave amplitudes than the solitary structures observed in the magnetosheath. The result indicates that a high-speed and small free energy source may be needed as a fifth component. An additional simulation of a five-component plasma consisting of a stable four-component plasma and a weak electron beam shows the generation of small and fast electron phase-space holes by the bump-on-tail instability. The physical properties of the small and fast electron phase-space holes are very similar to those obtained by the previous theoretical analysis. The amplitude and duration time of solitary structures in the simulation are also in agreement with the Cluster observation.

  6. Solitary wave propagation through two-dimensional treelike structures.

    Science.gov (United States)

    Falls, William J; Sen, Surajit

    2014-02-01

    It is well known that a velocity perturbation can travel through a mass spring chain with strongly nonlinear interactions as a solitary and antisolitary wave pair. In recent years, nonlinear wave propagation in 2D structures have also been explored. Here we first consider the propagation of such a velocity perturbation for cases where the system has a 2D "Y"-shaped structure. Here each of the three pieces that make up the "Y" are made of a small mass spring chain. In addition, we consider a case where multiple "Y"-shaped structures are used to generate a "tree." We explore the early time dynamical behavior associated with the propagation of a velocity perturbation initiated at the trunk and at the extremities for both cases. We are looking for the energy transmission properties from one branch to another of these "Y"-shaped structures. Our dynamical simulations suggest the following broad observations: (i) for strongly nonlinear interactions, mechanical energy propagation resembles pulse propagation with the energy propagation being dispersive in the linear case; (ii) for strong nonlinear interactions, the tree-like structure acts as an energy gate showing preference for large perturbations in the system while the behavior of the linear case shows no such preference, thereby suggesting that such structures can possibly act as switches that activate at sufficiently high energies. The study aspires to develop insights into the nature of nonlinear wave propagation through a network of linear chains.

  7. Solitary myeloma with massive extracellular crystalline structures--a case report.

    OpenAIRE

    Kim, Y. G.; Yang, K. H.; Gang, S. J.; Kim, B. K.; Kim, S. M.

    1991-01-01

    We describe a case of solitary myeloma showing cystic change filled with massive crystalline structures in a 54-year-old woman. A bone X-ray showed a solitary cystic osteolytic lesion in the right iliac bone. Serum and urine protein electrophoresis showed no demonstrable M-protein, and bone-marrow aspirates did not show any myeloma cells. Histologic examination of the tumor revealed aggregation of plasma cells with massive extracellular infiltration of the rhomboid-shaped crystalline structur...

  8. Analytical solitary wave solutions of the nonlinear Kronig-Penney model in photonic structures.

    Science.gov (United States)

    Kominis, Y

    2006-06-01

    A phase space method is employed for the construction of analytical solitary wave solutions of the nonlinear Kronig-Penney model in a photonic structure. This class of solutions is obtained under quite generic conditions, while the method is applicable to a large variety of systems. The location of the solutions on the spectral band gap structure as well as on the low dimensional space of system's conserved quantities is studied, and robust solitary wave propagation is shown.

  9. A hyperbolic function approach to constructing exact solitary wave solutions of the Hybrid lattice and discrete mKdV lattice

    Institute of Scientific and Technical Information of China (English)

    Zha Qi-Lao; Sirendaoreji

    2006-01-01

    Some new exact solitary wave solutions of the Hybrid lattice and discrete mKdV lattice are obtained by using a hyperbolic function approach.This approach can also be applied to other nonlinear differential-difference equations.

  10. Dust ion acoustic solitary structures in presence of nonthermally distributed electrons and positrons

    CERN Document Server

    Paul, Ashesh; Das, K P

    2016-01-01

    The purpose of this paper is to extend the recent work of Paul & Bandyopadhyay [Astrophys. Space Sci. 361, 172(2016)] on the existence of different dust ion acoustic solitary structures in an unmagnetized collisionless dusty plasma consisting of negatively charged static dust grains, adiabatic warm ions, nonthermal electrons and isothermal positrons in a more generalized form by considering nonthermal positrons instead of isothermal positrons. The present system supports both positive and negative potential double layers, coexistence of solitary waves of both polarities and positive potential supersolitons. The qualitative and the quantitative changes in existence domains of different solitary structures which occur for the presence of nonthermal positrons have been presented in comparison with the results of Paul & Bandyopadhyay [Astrophys. Space Sci. 361, 172(2016)]. The formation of supersoliton structures and their limitations have been analyzed with the help of phase portraits of the dynamical sy...

  11. Coherent structures in wave boundary layers. Part 2. Solitary motion

    DEFF Research Database (Denmark)

    Sumer, B. Mutlu; Jensen, Palle Martin; Sørensen, Lone B.;

    2010-01-01

    in an oscillating water tunnel. Two kinds of measurements were made: bed shear stress measurements and velocity measurements. The experiments show that the solitary-motion boundary layer experiences three kinds of flow regimes as the Reynolds number is increased: (i) laminar regime; (ii) laminar regime where...... the boundary-layer flow experiences a regular array of vortex tubes near the bed over a short period of time during the deceleration stage; and (iii) transitional regime characterized with turbulent spots, revealed by single/multiple, or, sometimes, quite dense spikes in the bed shear stress traces...

  12. A hybrid conformal planning technique with solitary dynamic portal for postmastectomy radiotherapy with regional nodes

    Directory of Open Access Journals (Sweden)

    K Mohamathu Rafic

    2017-01-01

    Full Text Available Purpose: This study focuses on incorporation of a solitary dynamic portal (SDP in conformal planning for postmastectomy radiotherapy (PMRT with nodal regions with an intention to overcome the treatment planning limitations imposed by conventional techniques. Materials and Methods: Twenty-four patients who underwent surgical mastectomy followed by PMRT were included in this study. Initially, a treatment plan comprising tangential beams fitted to beam's-eye-view (BEV of chest wall (CW and a direct anterior field fitted to BEV of nodal region, both sharing a single isocenter was generated using Eclipse treatment planning system. Multiple field-in-fields with optimum beam weights (5% per field were added primarily from the medial tangent, fitted to BEV of entire target volume, and finally converted into a dynamic portal. Dosimetric analysis for the treatment plans and fluence verification for the dynamic portals were performed. Results and Discussion: Conformal plans with SDP showed excellent dose coverage (V95%>95%, higher degree of tumor dose conformity (≤1.25 and homogeneity (≤0.12 without compromising the organ at risk sparing for PMRT with nodal region. Treatment plans with SDP considerably reduced the lower isodose spread to the ipsilateral lung, heart, and healthy tissue without affecting the dose homogeneity. Further, gamma evaluation showed more than 96% pixel pass rate for standard 3%/3 mm dose difference and distance-to-agreement criteria. Moreover, this plan offers less probability of “geometrical miss” at the highly irregular CW with regional nodal radiotherapy. Conclusion: Hybrid conformal plans with SDP would facilitate improved dose distribution and reduced uncertainty in delivery and promises to be a suitable treatment option for complex postmastectomy CW with regional nodal irradiation.

  13. Ion acoustic solitary structures in a collisionless unmagnetized plasma consisting of nonthermal electrons and isothermal positrons

    CERN Document Server

    Paul, Ashesh

    2016-01-01

    Employing the Sagdeev pseudo-potential technique the ion acoustic solitary structures have been investigated in an unmagnetized collisionless plasma consisting of adiabatic warm ions, nonthermal electrons and isothermal positrons. The qualitatively different compositional parameter spaces clearly indicate the existence domains of solitons and double layers with respect to any parameter of the present plasma system. The present system supports the negative potential double layer which always restricts the occurrence of negative potential solitons. The system also supports positive potential double layers when the ratio of the average thermal velocity of positrons to that of electrons is less than a critical value. However, there exists a parameter regime for which the positive potential double layer is unable to restrict the occurrence of positive potential solitary waves and in this region of the parameter space, there exist positive potential solitary waves after the formation of a positive potential double ...

  14. Solitary and shock structures in a strongly coupled cryogenic quantum plasma

    Energy Technology Data Exchange (ETDEWEB)

    Hossen, M. A., E-mail: armanplasma@gmail.com; Mamun, A. A. [Department of Physics, Jahangirnagar University, Savar, Dhaka 1342 (Bangladesh)

    2015-07-15

    The quantum ion-acoustic (QIA) solitary and shock structures formed in a strongly coupled cryogenic quantum plasma (containing strongly coupled positively charged inertial cold ions and Fermi electrons as well as positrons) have been theoretically investigated. The generalized quantum hydrodynamic model and the reductive perturbation method have been employed to derive the Korteweg-de Vries (K-dV) and Burgers equations. The basic features of the QIA solitary and shock structures are identified by analyzing the stationary solitary and shock wave solutions of the K-dV and Burgers equations. It is found that the basic characteristics (e.g., phase speed, amplitude, and width) of the QIA solitary and shock structures are significantly modified by the effects of the Fermi pressures of electrons and positrons, the ratio of Fermi temperature of positrons to that of electrons, the ratio of effective ion temperature to electron Fermi temperature, etc. It is also observed that the effect of strong correlation among extremely cold ions acts as a source of dissipation, and is responsible for the formation of the QIA shock structures. The results of this theoretical investigation should be useful for understanding the nonlinear features of the localized electrostatic disturbances in laboratory electron-positron-ion plasmas (viz., super-intense laser-dense matter experiments)

  15. Solitary myeloma with massive extracellular crystalline structures--a case report.

    Science.gov (United States)

    Kim, Y G; Yang, K H; Gang, S J; Kim, B K; Kim, S M

    1991-06-01

    We describe a case of solitary myeloma showing cystic change filled with massive crystalline structures in a 54-year-old woman. A bone X-ray showed a solitary cystic osteolytic lesion in the right iliac bone. Serum and urine protein electrophoresis showed no demonstrable M-protein, and bone-marrow aspirates did not show any myeloma cells. Histologic examination of the tumor revealed aggregation of plasma cells with massive extracellular infiltration of the rhomboid-shaped crystalline structures. In immunoperoxidase staining, both these crystalline structures and the cytoplasms of the myeloma cells demonstrated a positive reaction for lambda light chain. By electron microscope, the large extracellular crystalline structures were observed, and we found unique rhomboid or rectangular-shaped crystalline structures in the cytoplasms of the myeloma cells.

  16. Identification and determination of solitary wave structures in nonlinear wave propagation

    Energy Technology Data Exchange (ETDEWEB)

    Newman, W.I.; Campbell, D.K.; Hyman, J.M.

    1991-01-01

    Nonlinear wave phenomena are characterized by the appearance of solitary wave coherent structures'' traveling at speeds determined by their amplitudes and morphologies. Assuming that these structures are briefly noninteracting, we propose a method for the identification of the number of independent features and their respective speeds. Using data generated from an exact two-soliton solution to the Korteweg-de-Vries equation, we test the method and discuss its strengths and limitations. 41 refs., 2 figs.

  17. Properties of cylindrical and spherical heavy ion-acoustic solitary and shock structures in a multispecies plasma with superthermal electrons

    Science.gov (United States)

    Shah, M. G.; Rahman, M. M.; Hossen, M. R.; Mamun, A. A.

    2016-02-01

    A theoretical investigation on heavy ion-acoustic (HIA) solitary and shock structures has been accomplished in an unmagnetized multispecies plasma consisting of inertialess kappa-distributed superthermal electrons, Boltzmann light ions, and adiabatic positively charged inertial heavy ions. Using the reductive perturbation technique, the nonplanar (cylindrical and spherical) Kortewg-de Vries (KdV) and Burgers equations have been derived. The solitary and shock wave solutions of the KdV and Burgers equations, respectively, have been numerically analyzed. The effects of superthermality of electrons, adiabaticity of heavy ions, and nonplanar geometry, which noticeably modify the basic features (viz. polarity, amplitude, phase speed, etc.) of small but finite amplitude HIA solitary and shock structures, have been carefully investigated. The HIA solitary and shock structures in nonplanar geometry have been found to distinctly differ from those in planar geometry. Novel features of our present attempt may contribute to the physics of nonlinear electrostatic perturbation in astrophysical and laboratory plasmas.

  18. Arbitrary amplitude magnetosonic solitary and shock structures in spin quantum plasma

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, Biswajit [Department of Mathematics, West Bengal State University, Barasat, Kolkata-700126 (India); Sinha, Anjana; Roychoudhury, Rajkumar; Khan, Manoranjan [Department of Instrumentation Science, Jadavpur University, Kolkata-700 032 (India)

    2013-11-15

    A nonlinear analysis is carried out for the arbitrary amplitude magnetosonic solitary and shock structures in spin quantum plasmas. A quantum magnetohydrodynamic model is used to describe the magnetosonic quantum plasma with the Bohm potential and the pressure like spin force for electrons. Analytical calculations are used to simplify the basic equations, which are then studied numerically. It is shown that the magnetic diffusivity is responsible for dissipation, which causes the shock-like structures rather than the soliton structures. Additionally, wave speed, Zeeman energy, and Bohm potential are found to have significant impact on the shock wave structures.

  19. Debye-scale solitary structures measured in a beam-plasma laboratory experiment

    Directory of Open Access Journals (Sweden)

    B. Lefebvre

    2011-01-01

    Full Text Available Solitary electrostatic pulses have been observed in numerous places of the magnetosphere such as the vicinity of reconnection current sheets, shocks or auroral current systems, and are often thought to be generated by energetic electron beams. We present results of a series of experiments conducted at the UCLA large plasma device (LAPD where a suprathermal electron beam was injected parallel to a static magnetic field. Micro-probes with tips smaller than a Debye length enabled the detection of solitary pulses with positive electric potential and half-widths 4–25 Debye lengths (λDe, over a set of experiments with various beam energies, plasma densities and magnetic field strengths. The shape, scales and amplitudes of the structures are similar to those observed in space, and consistent with electron holes. The dependance of these properties on the experimental parameters is shown. The velocities of the solitary structures (1–3 background electron thermal velocities are found to be much lower than the beam velocities, suggesting an excitation mechanism driven by parallel currents associated to the electron beam.

  20. Solitary structures in a spatially nonuniform degenerate plasma in the presence of quantizing magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Masood, W. [COMSATS, Institute of Information Technology, Park Road, Chak Shahzad, Islamabad 44000 (Pakistan); National Center for Physics (NCP), Islamabad 44000 (Pakistan); Shaukat, Muzzamal I. [University of Engineering and Technology, Lahore (RCET Campus) 54000 (Pakistan); Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 44000 (Pakistan); Shah, H. A. [Department of Physics, Forman Christian College, Lahore 54000 (Pakistan); Mirza, Arshad M. [Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 44000 (Pakistan)

    2015-03-15

    In the present investigation, linear and nonlinear propagation of low frequency (ω≪Ω{sub ci}) electrostatic waves have been studied in a spatially inhomogeneous degenerate plasma with one dimensional electron trapping in the presence of a quantizing magnetic field and finite temperature effects. Using the drift approximation, formation of 1 and 2D drift ion solitary structures have been studied both for fully and partially degenerate plasmas. The theoretical results obtained have been analyzed numerically for the parameters typically found in white dwarfs for illustrative purpose. It is observed that the inclusion of Landau quantization significantly changes the expression of the electron number density of a dense degenerate plasma which affects the linear and nonlinear propagation of drift acoustic solitary waves in such a system. The present work may be beneficial to understand the propagation of drift solitary structures with weak transverse perturbation in a variety of physical situations, such as white dwarfs and laser-induced plasmas, where the quantum effects are expected to dominate.

  1. Solitary and double-layer structures in quantum bi-ion plasma

    Science.gov (United States)

    Shahmansouri, Mehran; Tribeche, Mouloud

    2016-06-01

    Weak ion-acoustic solitary waves (IASWs) in an unmagnetized quantum plasmas having two-fluid ions and fluid electrons are considered. Using the one-dimensional quantum hydrodynamics model and then the reductive perturbation technique, a generalized form of nonlinear quantum Korteweg-de Vries (KdV) equation governing the dynamics of weak ion acoustic solitary waves is derived. The effects of ion population, warm ion temperature, quantum diffraction, and polarity of ions on the nonlinear properties of these IASWs are analyzed. It is found that our present plasma model may support compressive as well as rarefactive solitary structures. Furthermore, formation and characteristics properties of IA double layers in the present bi-ion plasma model are investigated. The results of this work should be useful and applicable in understanding the wide relevance of nonlinear features of localized electro-acoustic structures in laboratory and space plasma, such as in super-dense astrophysical objects [24] and in the Earth's magnetotail region (Parks [43]. The implications of our results in some space plasma situations are discussed.

  2. Thoracic aorta aneurysm repair in a patient with a solitary kidney: Hybrid Surgery as a bailout procedure

    Directory of Open Access Journals (Sweden)

    Chris Bakoyiannis

    2016-11-01

    Full Text Available Thoracic endovascular aortic repair (TEVAR is an emerging treatment option for thoracic aorta aneurysms (TAA. Endovascular access is a challenge. We present a novel TEVAR-technique in a patient with single kidney and a 6.4cm TAA. Attempting to place a sheath through iliac arteries was unsuccessful. The decision to proceed to hybrid-TEVAR was made. The protection of the solitary kidney was achieved through axillo-femoral bypass, followed by an end-to-side anastomosis between the aorta and a bifurcated graft. Through the graft, a stent was introduced in the thoracic aorta. With the use of contrast material, the right position of the graft was confirmed.

  3. Clarification on Polarity of Bipolar Electric Field Solitary Structures in Space Plasmas with Satellite Observation

    Institute of Scientific and Technical Information of China (English)

    M. N. S.Qureshi; SHI Jian-Kui; LIU Zhen-Xing; Klaus Torkar

    2011-01-01

    The bipolar electric field solitary (EFS) structures observed frequently in space plasmas by satellites have two different polarities, first positive electric field peak then negative (i.e., positive/negative) and first negative then positive peak (i.e., negative/positive). We provide the physical explanation on the polarity of observed bipolar EFS structures with an electrostatic ion fluid model. The results show that ii initial electric field E0 > 0, the polarity of the bipolar EFS structure will be positive/negative; and if E0 < 0, the polarity of the bipolar EFS structure will be negative/positive. However, for a fixed polarity of the EFS, either positive/negative or negative/positive, if the satellite is located at the positive side of the EFS, the observed polarity should be positive/negative, if the satellite is located at the negative side of the EFS, the observed polarity should be negative/positive. Therefore, we provide a method to clarify the natural polarity of the EFS with observed polarity by satellites. Our results are significant to understand the physical process in space plasma with the satellite observation.%@@ The bipolar electric field solitary (EFS) structures observed frequently in space plasmas by satellites have two different polarities, first positive electric Held peak then negative (i.e., positive/negative) and first negative then positive peak (i.e., negative/positive).We provide the physical explanation on the polarity of observed bipolar EFS structures with an electrostatic ion fluid model.

  4. Jacobian Elliptic Function Method and Solitary Wave Solutions for Hybrid Lattice Equation

    Institute of Scientific and Technical Information of China (English)

    WANG Rui-Min; DAI Chao-Qing; ZHANG Jie-Fang

    2006-01-01

    In this paper, we have successfully extended the Jacobian elliptic function expansion approach to nonlinear differential-difference equations. The Hybrid lattice equation is chosen to illustrate this approach. As a consequence,twelve families of Jacobian elliptic function solutions with different parameters of the Hybrid lattice equation are obtained.When the modulus m → 1 or 0, doubly-periodic solutions degenerate to solitonic solutions and trigonometric function solutions, respectively.

  5. Comprehensive genome characterization of solitary fibrous tumors using high-resolution array-based comparative genomic hybridization.

    Science.gov (United States)

    Bertucci, François; Bouvier-Labit, Corinne; Finetti, Pascal; Adélaïde, José; Metellus, Philippe; Mokhtari, Karima; Decouvelaere, Anne-Valérie; Miquel, Catherine; Jouvet, Anne; Figarella-Branger, Dominique; Pedeutour, Florence; Chaffanet, Max; Birnbaum, Daniel

    2013-02-01

    Solitary fibrous tumors (SFTs) are rare spindle cell tumors with limited therapeutic options. Their molecular basis is poorly known. No consistent cytogenetic abnormality has been reported. We used high-resolution whole-genome array-based comparative genomic hybridization (Agilent 244K oligonucleotide chips) to profile 47 samples, meningeal in >75% of cases. Few copy number aberrations (CNAs) were observed. Sixty-eight percent of samples did not show any gene CNA after exclusion of probes located in regions with referenced copy number variation (CNV). Only low-level CNAs were observed. The genomic profiles were very homogeneous among samples. No molecular class was revealed by clustering of DNA copy numbers. All cases displayed a "simplex" profile. No recurrent CNA was identified. Imbalances occurring in >20%, such as the gain of 8p11.23-11.22 region, contained known CNVs. The 13q14.11-13q31.1 region (lost in 4% of cases) was the largest altered region and contained the lowest percentage of genes with referenced CNVs. A total of 425 genes without CNV showed copy number transition in at least one sample, but only but only 1 in at least 10% of samples. The genomic profiles of meningeal and extra-meningeal cases did not show any differences.

  6. Hybrid Simulation of Composite Structures

    DEFF Research Database (Denmark)

    Høgh, Jacob Herold

    Hybrid simulation is a substructural method combining a numerical simulation with a physical experiment. A structure is thereby simulated under the assumption that a substructure’s response is well known and easily modelled while a given substructure is studied more accurately in a physical...... of freedom. In this dissertation the main focus is to develop hybrid simulation for composite structures e.g. wind turbine blades where the boundary between the numerical model and the physical experiment is continues i.e. in principal infinite amount of degrees of freedom. This highly complicates...

  7. Personality, negative affect coping, and drinking alone: a structural equation modeling approach to examine correlates of adolescent solitary drinking.

    Science.gov (United States)

    Creswell, Kasey G; Chung, Tammy; Wright, Aidan G C; Clark, Duncan B; Black, Jessica J; Martin, Christopher S

    2015-05-01

    This study examined the personality traits of negative emotionality and constraint and the ability to resist drinking during negative affective states as correlates of solitary drinking in adolescence. We hypothesized that higher levels of negative emotionality and lower levels of constraint would predict solitary drinking and that these relationships would be mediated by the ability to resist drinking in response to negative emotions. Structural equation modeling was used to fit a path model from the personality traits of negative emotionality and constraint to solitary drinking status through intermediate effects on the ability to resist drinking during negative emotions using cross-sectional data. Clinical and community settings in Pennsylvania, USA. The sample included 761 adolescent drinkers (mean age = 17.1). Adolescents completed the Lifetime Drinking History, the Multidimensional Personality Questionnaire, the Constructive Thinking Inventory and the Situational Confidence Questionnaire. The path model provided a good fit to the data. The association between trait negative emotionality and solitary drinking was fully mediated by adolescents' ability to resist drinking during negative affective states (b = 0.05, P = 0.01). In contrast, constraint had a direct effect on solitary drinking (odds ratio (OR) = 0.79, b = -0.23, P<0.01), as well as an indirect effect through the ability to resist drinking during negative affective states (b = -0.03, P = 0.02). The ability to resist drinking while experiencing negative feelings or emotions may be an important underlying mechanism linking trait negative emotionality (a tendency toward depression, anxiety and poor reaction to stress) and constraint (lack of impulsiveness) to adolescent solitary drinking. © 2015 Society for the Study of Addiction.

  8. Hybrid Tower, Designing Soft Structures

    DEFF Research Database (Denmark)

    Ramsgaard Thomsen, Mette; Tamke, Martin; Holden Deleuran, Anders;

    2015-01-01

    predictions about the inherent interdependency and material dependent performance of the hybrid structure and (2) the inter-scalar design strategies for specification and fabrication. The first investigation focuses on the design pipelines developed between the implementation of realtime physics...... (membrane reinforcement strategy) and micro scale (design of bespoke textile membrane). The paper concludes with a post construction analysis. Comparing structural and environmental data, the predicted and the actual performance of tower are evaluated and discussed....

  9. Hybrid composite laminate structures

    Science.gov (United States)

    Chamis, C. C.; Lark, R. F. (Inventor)

    1977-01-01

    An invention which relates to laminate structures and specifically to essentially anisotropic fiber composite laminates is described. Metal foils are selectively disposed within the laminate to produce increased resistance to high velocity impact, fracture, surface erosion, and other stresses within the laminate.

  10. Electrostatic solitary structures in presence of non-thermal electrons and a warm electron beam on the auroral field lines

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S. V. [Indian Institute of Geomagnetism, Navi Mumbai (India); School of Physics, University of Kwazulu-Natal, Durban (South Africa); Lakhina, G. S. [Indian Institute of Geomagnetism, Navi Mumbai (India); Bharuthram, R. [University of the Western Cape, Bellville (South Africa); Pillay, S. R. [School of Physics, University of Kwazulu-Natal, Durban (South Africa)

    2011-12-15

    Electrostatic solitary waves (ESWs) have been observed by satellites in the auroral region of the Earth's magnetosphere. These ESWs are found to be having both positive and negative electrostatic potentials. Using the Sagdeeev psuedo-potential technique, arbitrary amplitude electron-acoustic solitary waves/double layers are studied in an unmagnetized plasma consisting of non-thermally distributed hot electrons, fluid cold electrons, a warm electron beam, and ions. The inertia of the warm electrons, and not the beam speed, is essential for the existence of positive potential solitary structures. Existence domains for positive as well as negative potential electrostatic solitons/double layers are obtained. For the typical auroral region parameters, the electric field amplitude of the negative potential solitons is found to be in the range {approx}(3-30) mV/m and {approx}(5-80) mV/m for the positive potential solitons. For the negative potential solitons/double layers, the amplitudes are higher when their widths are smaller. On the other hand, the amplitude of the positive potential structures increase with their widths.

  11. Magnetospheric solitary structure maintained by 3000 km/s ions as a cause of westward moving auroral bulge at 19 MLT

    Directory of Open Access Journals (Sweden)

    M. Yamauchi

    2009-07-01

    Full Text Available In the evening equatorial magnetosphere at about 4 RE geocentric distance and 19 MLT, the four Cluster spacecraft observed a solitary structure with a width of about 1000~2000 km in the propagation direction. The solitary structure propagates sunward with about 5~10 km/s carrying sunward electric field (in the propagation direction of up to about 10 mV/m (total potential drop of about 5~10 kV, depletion of magnetic field of about 25%, and a duskward E×B convection up to 50 km/s of He+ rich cold plasma without O+. At the same time, auroral images from the IMAGE satellite together with ground based geomagnetic field data showed a westward (sunward at this location propagating auroral bulge at the magnetically conjugate ionosphere with the solitary structure. The solitary structure is maintained by flux enhancement of selectively 3000 km/s ions (about 50 keV for H+, 200 keV for He+, and 750 keV for O+. These ions are the main carrier of the diamagnetic current causing the magnetic depletion, whereas the polarization is maintained by different behavior of energetic ions and electrons. Corresponding to aurora, field-aligned accelerated ionospheric plasma of several keV appeared at Cluster from both hemispheres simultaneously. Together with good correspondence in location and propagation velocity between the auroral bulge and the solitary structure, this indicates that the sunward moving auroral bulge is caused by the sunward propagation of the solitary structure which is maintained by energetic ions. The solitary structure might also be the cause of Pi2-like magnetic variation that started simultaneously at Cluster location.

  12. Hybrid Composite Cryogenic Tank Structure

    Science.gov (United States)

    DeLay, Thomas

    2011-01-01

    A hybrid lightweight composite tank has been created using specially designed materials and manufacturing processes. The tank is produced by using a hybrid structure consisting of at least two reinforced composite material systems. The inner composite layer comprises a distinct fiber and resin matrix suitable for cryogenic use that is a braided-sleeve (and/or a filamentwound layer) aramid fiber preform that is placed on a removable mandrel (outfitted with metallic end fittings) and is infused (vacuum-assisted resin transfer molded) with a polyurethane resin matrix with a high ductility at low temperatures. This inner layer is allowed to cure and is encapsulated with a filamentwound outer composite layer of a distinct fiber resin system. Both inner and outer layer are in intimate contact, and can also be cured at the same time. The outer layer is a material that performs well for low temperature pressure vessels, and it can rely on the inner layer to act as a liner to contain the fluids. The outer layer can be a variety of materials, but the best embodiment may be the use of a continuous tow of carbon fiber (T-1000 carbon, or others), or other high-strength fibers combined with a high ductility epoxy resin matrix, or a polyurethane matrix, which performs well at low temperatures. After curing, the mandrel can be removed from the outer layer. While the hybrid structure is not limited to two particular materials, a preferred version of the tank has been demonstrated on an actual test tank article cycled at high pressures with liquid nitrogen and liquid hydrogen, and the best version is an inner layer of PBO (poly-pphenylenebenzobisoxazole) fibers with a polyurethane matrix and an outer layer of T-1000 carbon with a high elongation epoxy matrix suitable for cryogenic temperatures. A polyurethane matrix has also been used for the outer layer. The construction method is ideal because the fiber and resin of the inner layer has a high strain to failure at cryogenic

  13. Progress on study of unusual structure of electrostatic solitary waves associated with magnetic reconnection in the near-Earth magnetotail

    Science.gov (United States)

    Li, Shiyou; Chen, Xiaoqian; Guo, Jianming

    2016-07-01

    The electrostatic solitary waves (ESWs) have been widely observed and studied for many years. In the magnetic reconnection process, ESWs are regarded as one kind of means for the fast energy release by outward propagating electrons along re-connecting magnetic field lines. In this report, we present observation evidences of two kinds of unusual structures of ESWs associated with magnetic reconnection in the near-Earth magnetotail, including the 2-D ESWs and the tri-polar ESWs. First of all, more than 300 of electrostatic solitary waves (ESWs) with large perpendicular component which is bi-polar waveform structure are observed in the boundary layer within magnetic reconnection diffusion region in the near-Earth magnetotail. Such kinds of ESWs are named as 2-D ESWs. Singe-Reconnection-Based-Statistical study of 2-D ESWs is performed. Secondly, more than 200 waveforms with clear tri-polar characteristics are differentiated along the plasma sheet boundary layer near the magnetic reconnection X-line in the near-Earth magnetotail. Within reconnection diffusion region, the tri-polar ESWs are ample and are continuously observed during one burst interval (8.75 seconds) of the Geotail/WFC in the neutral plasma sheet where and thus the tri-polar ESW is suggested to be one kind of steady-going solitary structure. Statistical analysis to the characteristics of tri-polar ESWs will also be carried out. The observation of 2-D ESWs and the tri-polar ESWs presents evidence of complex structure of electron holes within the reconnection diffusion region and is helpful to the understanding of the energy release process of reconnection.

  14. Structure of internal solitary waves in two-layer fluid at near-critical situation

    Science.gov (United States)

    Kurkina, O.; Singh, N.; Stepanyants, Y.

    2015-05-01

    A new model equation describing weakly nonlinear long internal waves at the interface between two thin layers of different density is derived for the specific relationships between the densities, layer thicknesses and surface tension between the layers. The equation derived and dubbed here the Gardner-Kawahara equation represents a natural generalisation of the well-known Korteweg-de Vries (KdV) equation containing the cubic nonlinear term as well as fifth-order dispersion term. Solitary wave solutions are investigated numerically and categorised in terms of two dimensionless parameters, the wave speed and fifth-order dispersion. The equation derived may be applicable to wave description in other media.

  15. On the processing of highly nonlinear solitary waves and guided ultrasonic waves for structural health monitoring and nondestructive evaluation

    Science.gov (United States)

    Bagheri, Abdollah

    The in-situ measurement of thermal stress in civil and mechanical structures may prevent structural anomalies such as unexpected buckling. In the first half of the dissertation, we present a study where highly nonlinear solitary waves (HNSWs) were utilized to measure axial stress in slender beams. HNSWs are compact non-dispersive waves that can form and travel in nonlinear systems such as one-dimensional chains of particles. The effect of the axial stress acting in a beam on the propagation of HNSWs was studied. We found that certain features of the solitary waves enable the measurement of the stress. In general, most guided ultrasonic waves (GUWs)-based health monitoring approaches for structural waveguides are based on the comparison of testing data to baseline data. In the second half of the dissertation, we present a study where some baseline-free signal processing algorithms were presented and applied to numerical and experimental data for the structural health monitoring (SHM) of underwater or dry structures. The algorithms are based on one or more of the following: continuous wavelet transform, empirical mode decomposition, Hilbert transform, competitive optimization algorithm, probabilistic methods. Moreover, experimental data were also processed to extract some features from the time, frequency, and joint time-frequency domains. These features were then fed to a supervised learning algorithm based on artificial neural networks to classify the types of defect. The methods were validated using the numerical model of a plate and a pipe, and the experimental study of a plate in water. In experiment, the propagation of ultrasonic waves was induced by means of laser pulses or transducer and detected with an array of immersion transducers. The results demonstrated that the algorithms are effective, robust against noise, and able to localize and classify the damage.

  16. Ultra-Lightweight Hybrid Structured Mirror Project

    Data.gov (United States)

    National Aeronautics and Space Administration — MMCC is proposing herewith a hybrid structured mirror that combines the advantages of SiC membrane and magnesium graphite composite. The significance of magnesium...

  17. Time-dependent cylindrical and spherical ion-acoustic solitary structures in relativistic degenerate multi-ion plasmas with positively-charged heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Hossen, M. R.; Nahar, L.; Mamun, A. A. [Jahangirnagar University,Savar, Dhaka (Bangladesh)

    2014-12-15

    The properties of time-dependent cylindrical and spherical, modified ion-acoustic (mIA) solitary structures in relativistic degenerate multi-ion plasmas (containing degenerate electron fluids, inertial positively-, as well as negatively-, charged light ions, and positively-charged static heavy ions) have been investigated theoretically. This investigation is valid for both non-relativistic and ultrarelativistic limits. The well-known reductive perturbation method has been used to derive the Korteweg-de Vries (K-dV) and the mK-dV equations for studying the basic features of solitary waves. The fundamental characteristics of mIA solitary waves are found to be significantly modified by the effects of the degenerate pressures of the electron and the ion fluids, their number densities, and the various charge states of heavy ions. The relevance of our results in astrophysical compact objects like white dwarfs and neutron stars, which are of scientific interest, is briefly discussed.

  18. Inferring social structure and its drivers from refuge use in the desert tortoise, a relatively solitary species

    Science.gov (United States)

    Sah, Pratha; Nussear, Kenneth E.; Esque, Todd C.; Aiello, Christina M.; Hudson, Peter J.; Bansal, Shweta

    2016-01-01

    For several species, refuges (such as burrows, dens, roosts, nests) are an essential resource for protection from predators and extreme environmental conditions. Refuges also serve as focal sites for social interactions including mating, courtship and aggression. Knowledge of refuge use patterns can therefore provide information about social structure, mating and foraging success, as well as the robustness and health of wildlife populations, especially for species considered to be relatively solitary. In this study, we construct networks of burrow use to infer social associations in a threatened wildlife species typically considered solitary - the desert tortoise. We show that tortoise social networks are significantly different than null networks of random associations, and have moderate spatial constraints. We next use statistical models to identify major mechanisms behind individual-level variation in tortoise burrow use, popularity of burrows in desert tortoise habitat and test for stressor-driven changes in refuge use patterns. We show that seasonal variation has a strong impact on tortoise burrow switching behavior. On the other hand, burrow age and topographical condition influence the number of tortoises visiting a burrow in desert tortoise habitat. Of three major population stressors affecting this species (translocation, drought, disease), translocation alters tortoise burrow switching behavior, with translocated animals visiting fewer unique burrows than residents. In a species that is not social, our study highlights the importance of leveraging refuge use behavior to study the presence of and mechanisms behind non-random social structure and individual-level variation. Our analysis of the impact of stressors on refuge-based social structure further emphasizes the potential of this method to detect environmental or anthropogenic disturbances.

  19. A hybrid piezoelectric structure for wearable nanogenerators

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Minbaek; Wang, Sihong; Wang, Zhong Lin [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Chen, Chih-Yen [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Department of Materials Science and Engineering, National Tsing-Hua University, Hsinchu, 30013 (China); Cha, Seung Nam; Park, Yong Jun; Kim, Jong Min [Frontier Research Lab, Samsung Advanced Institute of Technology, Samsung Electronics, Gyeonggi-Do 446-712 (Korea, Republic of); Chou, Li-Jen [Department of Materials Science and Engineering, National Tsing-Hua University, Hsinchu, 30013 (China)

    2012-04-03

    A hybrid-fiber nanogenerator comprising a ZnO nanowire array, PVDF polymer and two electrodes is presented. Depending on the bending or spreading action of the human arm, at an angle of {proportional_to}90 , the hybrid fiber reaches electrical outputs of {proportional_to}0.1 V and {proportional_to}10 nA cm{sup -2}. The unique structure of the hybrid fiber may inspire future research in wearable energy-harvesting technology. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Euro hybrid materials and structures. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Hausmann, Joachim M.; Siebert, Marc (eds.)

    2016-08-01

    In order to use the materials as best as possible, several different materials are usually mixed in one component, especially in the field of lightweight design. If these combinations of materials are joined inherently, they are called multi material design products or hybrid structures. These place special requirements on joining technology, design methods and manufacturing and are challenging in other aspects, too. The eight chapters with manuscripts of the presentations are: Chapter 1- Interface: What happens in the interface between the two materials? Chapter 2 - Corrosion and Residual Stresses: How about galvanic corrosion and thermal residual stresses in the contact zone of different materials? Chapter 3 - Characterization: How to characterize and test hybrid materials? Chapter 4 - Design: What is a suitable design and dimensioning method for hybrid structures? Chapter 5 - Machining and Processing: How to machine and process hybrid structures and materials? Chapter 6 - Component Manufacturing: What is a suitable manufacturing route for hybrid structures? Chapter 7 - Non-Destructive Testing and Quality Assurance: How to assure the quality of material and structures? Chapter 8 - Joining: How to join components of different materials?.

  1. Study of hybrid orientation structure wafer*

    Institute of Scientific and Technical Information of China (English)

    Tan Kaizhou; Zhang Jing; Xu Shiliu; Zhang Zhengfan; Yang Yonghui; Chen Jun; Liang Tao

    2011-01-01

    Two types of 5 μm thick hybrid orientation structure wafers, which were integrated by (110) or (100) orientation silicon wafers as the substrate, have been investigated for 15-40 V voltage ICs and MEMS sensor applications. They have been obtained mainly by SOI wafer bonding and a non-selective epitaxy technique, and have been presented in China for the first time. The thickness of BOX SiO2 buried in wafer is 220 nm. It has been found that the quality of hybrid orientation structure with (100) wafer substrate is better than that with (110) wafer substrate by “Sirtl defect etching of HOSW”.

  2. Dust acoustic solitary structures in a multi-fluid dusty plasma in the presence of kappa distributed particles

    Science.gov (United States)

    Singh, Manpreet; Singh Saini, Nareshpal; Ghai, Yashika; Kaur, Nimardeep

    2016-07-01

    Dusty plasma is a fully or partially ionized gas which contain micron or sub-micron sized dust particles. These dust particles can be positively or negatively charged, depending upon the mechanism of charging . Dusty plasma is often observed in most of the space and astrophysical plasma environments. Presence of these dust particles can modify the dispersion properties of waves in the plasma and can introduce several new wave modes, e.g., dust acoustic (DA) waves, dust-ion acoustic (DIA) waves, dust-acoustic shock waves etc. In this investigation we have studied the small amplitude dust acoustic waves in an unmagnetized plasma comprising of electrons, positively charged ions, negatively charged hot as well as cold dust. Electrons and ions are described by superthermal distribution which is more appropriate for modeling space and astrophysical plasmas. Kadomtsev- Petviashvili (KP) equation has been derived using reductive perturbation technique. Positive as well as negative potential structures are observed, depending upon some critical values of parameters. Amplitude and width of dust acoustic solitary waves are modified by varying these parameters such as superthermality of electrons and ions, direction of propagation of the wave, relative concentration of hot and cold dust particles etc. This study may be helpful in understanding the formation and dynamics of nonlinear structures in various space and astrophysical plasma environments such Saturn's F-rings.

  3. Kinematic Analysis of a Hybrid Structure

    Directory of Open Access Journals (Sweden)

    Q.J. Duan

    2012-11-01

    Full Text Available This paper presents a kinematic analysis and simulation of a hybrid structure applied to the new design cable-suspended feed structure (CSFS for the next generation of large spherical radio telescopes. First, considering the requirement that feeds should be tilted from 40° to 60° and that the tracking precision in steady state is 4mm, a novel design of the feed supporting structure including a cable-cabin structure, an AB axis structure and a Stewart platform is performed. Next, kinematic analysis and the simulation of the CSFS are done. Simulations have been developed in combination with the 50m CSFS model, which demonstrate the effectiveness and feasibility of the proposed three-level cable-suspended feed system.

  4. Hybrid Method Simulation of Slender Marine Structures

    DEFF Research Database (Denmark)

    Christiansen, Niels Hørbye

    This present thesis consists of an extended summary and five appended papers concerning various aspects of the implementation of a hybrid method which combines classical simulation methods and artificial neural networks. The thesis covers three main topics. Common for all these topics...... is that they deal with time domain simulation of slender marine structures such as mooring lines and flexible risers used in deep sea offshore installations. The first part of the thesis describes how neural networks can be designed and trained to cover a large number of different sea states. Neural networks can...... that a single neural network can cover all relevant sea states. The applicability and performance of the present hybrid method is demonstrated on a numerical model of a mooring line attached to a floating offshore platform. The second part of the thesis demonstrates how sequential neural networks can be used...

  5. Non Planar Electrostatic Solitary Wave Structures in Negative Ion Degenerate Plasma

    Institute of Scientific and Technical Information of China (English)

    S.Hussain; N.Akhtar; Saeed-ur-Rehman

    2011-01-01

    @@ Theoretical and numerical studies are performed for quantum ion acoustic solitons in planar and non-planar geometries in an unmagnetized homogenous plasma consisting of warm positive and negative ions with nonthermal electrons.A deformed Korteweg de Vries(DKdV)equation is derived by using the reductive perturbation method.The numerical solution to the DKdV equation indicates that the quantum parameter, temperatures of positive ions, temperture of negative ions and electron density blatantly influence the propagation speed and the structure of quantum ion acoustic solitons.The geometrical effects on the structure of quantum ion acoustic wave are discussed.It is shown that the amplitude and propagation speed in spherical geometry is larger as compared to cylinderical and planar geometries for different values of the above-mentioned parameters.%Theoretical and numerical studies are performed for quantum ion acoustic solitons in planar and non-planar geometries in an unmagnetized homogenous plasma consisting of warm positive and negative ions with nonthermal electrons. A deformed Korteweg de Vries (DKdV) equation is derived by using the reductive perturbation method.The numerical solution to the DKdV equation indicates that the quantum parameter, temperatures of positive ions, temperture of negative ions and electron density blatantly influence the propagation speed and the structure of quantum ion acoustic solitons. The geometrical effects on the structure of quantum ion acoustic wave are discussed. It is shown that the amplitude and propagation speed in spherical geometry is larger as compared to cylinderical and planar geometries for different values of the above-mentioned parameters.

  6. Solitary waves and homoclinic orbits

    Energy Technology Data Exchange (ETDEWEB)

    Balmforth, N.J.

    1994-03-01

    The notion that fluid motion often organizes itself into coherent structures has increasingly permeated modern fluid dynamics. Such localized objects appear in laminar flows and persist in turbulent states; from the water on windows on rainy days, to the circulations in planetary atmospheres. This review concerns solitary waves in fluids. More specifically, it centres around the mathematical description of solitary waves in a single spatial dimension. Moreover, it concentrates on strongly dissipative dynamics, rather than integrable systems like the KdV equation. One-dimensional solitary waves, or pulses and fronts as they are also called, are the simplest kinds of coherent structure (at least from a geometrical point of view). Nevertheless, their dynamics can be rich and complicated. In some circumstances this leads to the formation of spatio-temporal chaos in the systems giving birth to the solitary waves, and understanding that phenomenon is one of the major goals in the theory outlined in this review. Unfortunately, such a goal is far from achieved to date, and the author assess its current status and incompleteness.

  7. High performance hybrid magnetic structure for biotechnology applications

    Science.gov (United States)

    Humphries, David E [El Cerrito, CA; Pollard, Martin J [El Cerrito, CA; Elkin, Christopher J [San Ramon, CA

    2009-02-03

    The present disclosure provides a high performance hybrid magnetic structure made from a combination of permanent magnets and ferromagnetic pole materials which are assembled in a predetermined array. The hybrid magnetic structure provides means for separation and other biotechnology applications involving holding, manipulation, or separation of magnetic or magnetizable molecular structures and targets. Also disclosed are further improvements to aspects of the hybrid magnetic structure, including additional elements and for adapting the use of the hybrid magnetic structure for use in biotechnology and high throughput processes.

  8. Solitary plasmacytoma of spine with amyloidosis

    Directory of Open Access Journals (Sweden)

    Cui-yun SUN

    2017-01-01

    Full Text Available Objective To report the diagnosis and treatment of one case of solitary plasmacytoma of spine with amyloidosis and investigate the clinicopathological features combined with literatures. Methods and Results The patient was a 46-year-old woman. She suffered from weakness of both lower limbs, unsteady gait and numbness of toes for 20 d. MRI examination revealed an irregular mass behind the spinal cord at T5-7 level and T6-7 vertebral body accessory. The enhanced MRI showed obvious heterogeneous enhancement. The border was clear and spinal dura mater was compressed to shift forward. During operation, T5-7 processus spinosus and vertebral laminae were eroded, and the cortex of bone showed "moth-eaten" erosion. The intraspinal and extradural lesion had rich blood supply, loose bone structure and intact spinal dura mater. Histologically, tumor cells were composed of intensive small cells, and focal plasmacytoid cells were seen. Flake pink staining substance was among them. Artificial cracks were common and multinuclear giant tumor cells were scatteredly distributed. Immunohistochemical analysis showed the cytoplasm of tumor cells were diffusely positive for CD138, CD38 and vimentin (Vim,scatteredly positive for leukocyte common antigen (LCA, and negative for immune globulin κ light chain(IgGκ and λ light chain (IgGλ, CD99, S-100 protein (S-100, pan cytokeratin (PCK, epithelial membrane antigen (EMA, HMB45 and CD34. The Ki-67 labeling index was 1.25%. Congo red staining showed the pink staining substance was brownish red. Hybridization in situ examination showed the DNA content of IgGκ was more than that of IgGλ. The final pathological diagnosis was solitary plasmacytoma of spine with amyloidosis. The patient was treated with postoperative chemotherapy, and there was no recurrence or metastasis during 18-month follow-up period. Conclusions Solitary plasmacytoma of spine with amyloidosis is a rare tumor. The imaging features can offer a few

  9. [Hybridization of crucian carp, Carassius carassius (Linnaeus, 1758), in Ukrainian reservoirs and genetic structure of hybrids].

    Science.gov (United States)

    Mezhzheryn, S V; Kokodyĭĭ, S V; Kulysh, A V; Verlat'iĭĭ, D B; Fedorenko, L V

    2012-01-01

    Hybridization of crucian carps Carassius carassius in polyspecific crucian populations of reservoirs of Ukraine and genetic structure of the hybrids were investigated using biochemical gene marking and cytometric procedure. The fact of wide hybridization between C. auratus and C. carassius was proved to be true by large number of hybrids which can form populations consisting only from hybrid individuals. Hybrids C. auratus x C. carassius were diploid, tryploid and in exceptional cases tetraploid; females and males which most likely breed by hybridogenesis. Besides, some clonal hybrids C. carassius x C. gibelio-1 appearing as tetraploid females, and one triploid female C. carassius x Tinca tinca were revealed. It is supported that hybridization of alien C. auratus with endemic C. carassius became one of mechanisms of replacement and depressions of populations of the last.

  10. Bumblebees and solitary bees

    DEFF Research Database (Denmark)

    Henriksen, Casper Christian I

    Summary: The effects of farming system, flower resources and semi-natural habitats on bumblebees and solitary bees in intensively cultivated landscapes in Denmark were investigated in two sets of studies, in 2011 and 2012. The pan trap colour preferences of bumblebees and solitary bees were also...... assessed. In 2011, bumblebees and solitary bees were trapped in road verges bordering 14 organic (organic sites) and 14 conventional (conventional sites) winter wheat fields. The quantity and quality of local flower resources in the road verge and adjacent field headland were estimated as overall density...... use as a proxy at four different scales (250, 500, 750 and 1000 m). In 2012, the effect of a four-fold larger area of organic arable fields in simple, homogeneous landscapes on bumblebees and solitary bees was investigated in eight circular landscapes (radius 1000 m). Bumblebees and solitary bees were...

  11. Structure and biological activities of eumenine mastoparan-AF (EMP-AF), a new mast cell degranulating peptide in the venom of the solitary wasp (Anterhynchium flavomarginatum micado).

    Science.gov (United States)

    Konno, K; Hisada, M; Naoki, H; Itagaki, Y; Kawai, N; Miwa, A; Yasuhara, T; Morimoto, Y; Nakata, Y

    2000-11-01

    A new mast cell degranulating peptide, eumenine mastoparan-AF (EMP-AF), was isolated from the venom of the solitary wasp Anterhynchium flavomarginatum micado, the most common eumenine wasp found in Japan. The structure was analyzed by FAB-MS/MS together with Edman degradation, which was corroborated by solid-phase synthesis. The sequence of EMP-AF, Ile-Asn-Leu-Leu-Lys-Ile-Ala-Lys-Gly-Ile-Ile-Lys-Ser-Leu-NH(2), was similar to that of mastoparan, a mast cell degranulating peptide from a hornet venom; tetradecapeptide with C-terminus amidated and rich in hydrophobic and basic amino acids. In fact, EMP-AF exhibited similar activity to mastoparan in stimulating degranulation from rat peritoneal mast cells and RBL-2H3 cells. It also showed significant hemolytic activity in human erythrocytes. Therefore, this is the first example that a mast cell degranulating peptide is found in the solitary wasp venom. Besides the degranulation and hemolytic activity, EMP-AF also affects on neuromuscular transmission in the lobster walking leg preparation. Three analogs EMP-AF-1 approximately 3 were snythesized and biologically tested together with EMP-AF, resulting in the importance of the C-terminal amide structure for biological activities.

  12. Hybrid Testing of Composite Structures with Single-Axis Control

    DEFF Research Database (Denmark)

    Waldbjørn, Jacob Paamand; Høgh, Jacob Herold; Stang, Henrik

    2013-01-01

    a hybrid testing platform is introduced for single-component hybrid testing. In this case, the boundary between the numerical model and experimental setup is defined by multiple Degrees-Of-Freedoms (DOFs) which highly complicate the transferring of response between the two substructures. Digital Image......Hybrid testing is a substructuring technique where a structure is emulated by modelling a part of it in a numerical model while testing the remainder experimentally. Previous research in hybrid testing has been performed on multi-component structures e.g. damping fixtures, however in this paper...... Correlation (DIC) is therefore implemented for displacement control of the experimental setup. The hybrid testing setup was verified on a multicomponent structure consisting of a beam loaded in three point bending and a numerical structure of a frame. Furthermore, the stability of the hybrid testing loop...

  13. Breaking Dense Structures: Proving Stability of Densely Structured Hybrid Systems

    Directory of Open Access Journals (Sweden)

    Eike Möhlmann

    2015-06-01

    Full Text Available Abstraction and refinement is widely used in software development. Such techniques are valuable since they allow to handle even more complex systems. One key point is the ability to decompose a large system into subsystems, analyze those subsystems and deduce properties of the larger system. As cyber-physical systems tend to become more and more complex, such techniques become more appealing. In 2009, Oehlerking and Theel presented a (de-composition technique for hybrid systems. This technique is graph-based and constructs a Lyapunov function for hybrid systems having a complex discrete state space. The technique consists of (1 decomposing the underlying graph of the hybrid system into subgraphs, (2 computing multiple local Lyapunov functions for the subgraphs, and finally (3 composing the local Lyapunov functions into a piecewise Lyapunov function. A Lyapunov function can serve multiple purposes, e.g., it certifies stability or termination of a system or allows to construct invariant sets, which in turn may be used to certify safety and security. In this paper, we propose an improvement to the decomposing technique, which relaxes the graph structure before applying the decomposition technique. Our relaxation significantly reduces the connectivity of the graph by exploiting super-dense switching. The relaxation makes the decomposition technique more efficient on one hand and on the other allows to decompose a wider range of graph structures.

  14. Genetic structure in a dynamic baboon hybrid zone corroborates behavioural observations in a hybrid population

    NARCIS (Netherlands)

    Charpentier, M J E; Fontaine, M C; Cherel, E; Renoult, J P; Jenkins, T; Benoit, L; Barthès, N; Alberts, S C; Tung, J

    2012-01-01

    Behaviour and genetic structure are intimately related: mating patterns and patterns of movement between groups or populations influence the movement of genetic variation across the landscape and from one generation to the next. In hybrid zones, the behaviour of the hybridizing taxa can also impact

  15. Variable separation solutions and new solitary wave structures to the (1+1)-dimensional equations of long-wave-short-wave resonant interaction

    Institute of Scientific and Technical Information of China (English)

    Xu Chang-Zhi; He Bao-Gang; Zhang Jie-Fang

    2004-01-01

    A variable separation approach is proposed and extended to the (1+1)-dimensional physical system. The variable separation solutions of (1+1)-dimensional equations of long-wave-short-wave resonant interaction are obtained. Some special type of solutions such as soliton solution, non-propagating solitary wave solution, propagating solitary wave solution, oscillating solitary wave solution are found by selecting the arbitrary function appropriately.

  16. Multi-dimensional instability of dust-ion-acoustic solitary structure with opposite polarity ions and non-thermal electrons

    Science.gov (United States)

    Haider, M. M.; Rahman, O.

    2016-12-01

    An attempt has been made to study the multi-dimensional instability of dust-ion-acoustic (DIA) solitary waves (SWs) in magnetized multi-ion plasmas containing opposite polarity ions, opposite polarity dusts and non-thermal electrons. First of all, we have derived Zakharov-Kuznetsov (ZK) equation to study the DIA SWs in this case using reductive perturbation method as well as its solution. Small- k perturbation technique was employed to find out the instability criterion and growth rate of such a wave which can give a guideline in understanding the space and laboratory plasmas, situated in the D-region of the Earth's ionosphere, mesosphere, and solar photosphere, as well as the microelectronics plasma processing reactors.

  17. Silicone-containing aqueous polymer dispersions with hybrid particle structure.

    Science.gov (United States)

    Kozakiewicz, Janusz; Ofat, Izabela; Trzaskowska, Joanna

    2015-09-01

    In this paper the synthesis, characterization and application of silicone-containing aqueous polymer dispersions (APD) with hybrid particle structure are reviewed based on available literature data. Advantages of synthesis of dispersions with hybrid particle structure over blending of individual dispersions are pointed out. Three main processes leading to silicone-containing hybrid APD are identified and described in detail: (1) emulsion polymerization of organic unsaturated monomers in aqueous dispersions of silicone polymers or copolymers, (2) emulsion copolymerization of unsaturated organic monomers with alkoxysilanes or polysiloxanes with unsaturated functionality and (3) emulsion polymerization of alkoxysilanes (in particular with unsaturated functionality) and/or cyclic siloxanes in organic polymer dispersions. The effect of various factors on the properties of such hybrid APD and films as well as on hybrid particles composition and morphology is presented. It is shown that core-shell morphology where silicones constitute either the core or the shell is predominant in hybrid particles. Main applications of silicone-containing hybrid APD and related hybrid particles are reviewed including (1) coatings which show specific surface properties such as enhanced water repellency or antisoiling or antigraffiti properties due to migration of silicone to the surface, and (2) impact modifiers for thermoplastics and thermosets. Other processes in which silicone-containing particles with hybrid structure can be obtained (miniemulsion polymerization, polymerization in non-aqueous media, hybridization of organic polymer and polysiloxane, emulsion polymerization of silicone monomers in silicone polymer dispersions and physical methods) are also discussed. Prospects for further developments in the area of silicone-containing hybrid APD and related hybrid particles are presented.

  18. Structural and mechanical properties of Laponite-PEG hybrid films.

    Science.gov (United States)

    Shikinaka, Kazuhiro; Aizawa, Kazuto; Murakami, Yoshihiko; Osada, Yoshihito; Tokita, Masatoshi; Watanabe, Junji; Shigehara, Kiyotaka

    2012-03-01

    Inorganic/organic hybrids were obtained by the sol-gel type organic modification reaction of Laponite sidewalls with poly(ethylene glycol) (PEG) bearing alkoxysiloxy terminal functionality. By casting an aqueous dispersion of the hybrid, the flexible and transparent hybrid films were obtained. Regardless of the inorganic/organic component ratio, the hybrid film had the ordered structure of Laponite in-plane flat arrays. The mechanical strength of hybrid films was drastically improved by the presence of cross-linking among alkoxysilyl functionalities of PEG terminals and the absence of PEG crystallines. Hybrid films, especially those that consisted of PEG with short chain, showed good mechanical properties that originate from quasi-homogeneous dispersion of components due to anchoring of PEG terminal to Laponite sidewall and interaction of PEG to Laponite surface.

  19. Advanced fiber-composite hybrids--A new structural material

    Science.gov (United States)

    Chamis, C. C.; Lark, R. F.; Sullivan, T. L.

    1974-01-01

    Introduction of metal foil as part of matrix and fiber composite, or ""sandwich'', improves strength and stiffness for multidirectional loading, improves resistance to cyclic loading, and improves impact and erosion resistance of resultant fiber-composite hybrid structure.

  20. Designing CNC Knit for Hybrid Membrane And Bending Active Structures

    DEFF Research Database (Denmark)

    Tamke, Martin; Holden Deleuran, Anders; Gengnagel, Christoph

    2015-01-01

    Recent advances in computation allow for the integration of design and simulation of highly interrelated systems, such as hybrids of structural membranes and bending active elements. The engaged complexities of forces and logistics can be mediated through the development of materials with project...... means to design, specify, make and test CNC knit as material for hybrid structures in architectural scale. This paper shares the developed process, identifies challenges, potentials and future work...

  1. Modulation instability and dissipative ion-acoustic structures in collisional nonthermal electron-positron-ion plasma: solitary and shock waves

    Science.gov (United States)

    Guo, Shimin; Mei, Liquan; He, Ya-Ling; Ma, Chenchen; Sun, Youfa

    2016-10-01

    The nonlinear behavior of an ion-acoustic wave packet is investigated in a three-component plasma consisting of warm ions, nonthermal electrons and positrons. The nonthermal components are assumed to be inertialess and hot where they are modeled by the kappa distribution. The relevant processes, including the kinematic viscosity amongst the plasma constituents and the collision between ions and neutrals, are taken into consideration. It is shown that the dynamics of the modulated ion-acoustic wave is governed by the generalized complex Ginzburg-Landau equation with a linear dissipative term. The dispersion relation and modulation instability criterion for the generalized complex Ginzburg-Landau equation are investigated numerically. In the general dissipation regime, the effect of the plasma parameters on the dissipative solitary (dissipative soliton) and shock waves is also discussed in detail. The project is supported by NSF of China (11501441, 11371289, 11371288), National Natural Science Foundation of China (U1261112), China Postdoctoral Science Foundation (2014M560756), and Fundamental Research Funds for the Central Universities (xjj2015067).

  2. Solitary Tibial Osteolytic Lesion

    Directory of Open Access Journals (Sweden)

    Emilios E. Pakos

    2009-01-01

    Full Text Available We report an unusual case of solitary osteolytic tibial metastasis from a primary endometrial cancer in a 62-year-old woman. The primary cancer was treated with total abdominal hysterectomy and bilateral salpingo-oophorectomy combined with postoperative external beam radiotherapy, while the tibial metastasis was treated with an above knee amputation. The rarity of the case lies on the fact that metastases distally to the elbow and knee are uncommon and endometrial cancer rarely gives distal bone metastases and particularly solitary to the extremities.

  3. Hybrid Optimization in the Design of Reciprocal Structures

    DEFF Research Database (Denmark)

    Parigi, Dario; Kirkegaard, Poul Henning; Sassone, Mario

    2012-01-01

    The paper presents a method to generate the geometry of reciprocal structures by means of a hybrid optimization procedure. The geometry of reciprocal structures where elements are sitting on the top or in the bottom of each other is extremely difficult to predict because of the non...... is then applied to a recent example of free-form reciprocal structure....

  4. Solitary Solution of Discrete mKdV Equation by Homotopy Analysis Method

    Institute of Scientific and Technical Information of China (English)

    XU Xi-Xiang; WANG Zhen; YANG Hong-Xiang; ZOU Li; LU Rong-Wu; ZHANG Hong-Qing

    2008-01-01

    In this paper, we apply homotopy analysis method to solve discrete mKdV equation and successfully obtain the bell-shaped solitary solution to mKdV equation. Comparison between our solution and the exact solution shows that homotopy analysis method is effective and validity in solving hybrid nonlinear problems, including solitary solution of difference-differential equation.

  5. Design of Hybrid Solid Polymer Electrolytes: Structure and Properties

    Science.gov (United States)

    Bronstein, Lyudmila M.; Karlinsey, Robert L.; Ritter, Kyle; Joo, Chan Gyu; Stein, Barry; Zwanziger, Josef W.

    2003-01-01

    This paper reports synthesis, structure, and properties of novel hybrid solid polymer electrolytes (SPE's) consisting of organically modified aluminosilica (OM-ALSi), formed within a poly(ethylene oxide)-in-salt (Li triflate) phase. To alter the structure and properties we fused functionalized silanes containing poly(ethylene oxide) (PEO) tails or CN groups.

  6. Calibrated and Interactive Modelling of Form-Active Hybrid Structures

    DEFF Research Database (Denmark)

    Quinn, Gregory; Holden Deleuran, Anders; Piker, Daniel

    2016-01-01

    Form-active hybrid structures (FAHS) couple two or more different structural elements of low self weight and low or negligible bending flexural stiffness (such as slender beams, cables and membranes) into one structural assembly of high global stiffness. They offer high load-bearing capacity...... materially-informed sketching. Making use of a projection-based dynamic relaxation solver for structural analysis, explorative design has proven to be highly effective....

  7. Nafion–clay hybrids with a network structure

    KAUST Repository

    Burgaz, Engin

    2009-05-01

    Nafion-clay hybrid membranes with a unique microstructure were synthesized using a fundamentally new approach. The new approach is based on depletion aggregation of suspended particles - a well-known phenomenon in colloids. For certain concentrations of clay and polymer, addition of Nafion solution to clay suspensions in water leads to a gel. Using Cryo-TEM we show that the clay particles in the hybrid gels form a network structure with an average cell size in the order of 500 nm. The hybrid gels are subsequently cast to produce hybrid Nafion-clay membranes. Compared to pure Nafion the swelling of the hybrid membranes in water and methanol is dramatically reduced while their selectivity (ratio of conductivity over permeability) increases. The small decrease of ionic conductivity for the hybrid membranes is more than compensated by the large decrease in methanol permeability. Lastly the hybrid membranes are much stiffer and can withstand higher temperatures compared to pure Nafion. Both of these characteristics are highly desirable for use in fuel cell applications, since a) they will allow the use of a thinner membrane circumventing problems associated with the membrane resistance and b) enable high temperature applications. © 2009 Elsevier Ltd. All rights reserved.

  8. Nanofiber of ultra-structured aluminum and zirconium oxide hybrid.

    Science.gov (United States)

    Kim, Hae-Won; Kim, Hyoun-Ee

    2006-02-01

    An internally ultrastructured Al- and Zr-oxide hybrid was developed into a nanofiber. As a precursor for the generation of nanofiber, a hybridized sol was prepared using the Pechini-type sol-gel process, whereby the Al- and Zr-metallic ions were to be efficiently distributed and stabilized within the polymeric network. The hybridized sol was subsequently electrospun and heat treated to a nanofiber with diameters of tens to hundreds of nanometers. The internal structure of the nanofiber was organized at the molecular level, with the Al- and Zr-oxide regions being interspaced at distances of less than ten nanometers. This ultrastructured Al- and Zr-oxide hybrid nanofiber is considered to be potentially applicable in numerous fields.

  9. Topologically ordered magnesium-biopolymer hybrid composite structures.

    Science.gov (United States)

    Oosterbeek, Reece N; Seal, Christopher K; Staiger, Mark P; Hyland, Margaret M

    2015-01-01

    Magnesium and its alloys are intriguing as possible biodegradable biomaterials due to their unique combination of biodegradability and high specific mechanical properties. However, uncontrolled biodegradation of magnesium during implantation remains a major challenge in spite of the use of alloying and protective coatings. In this study, a hybrid composite structure of magnesium metal and a biopolymer was fabricated as an alternative approach to control the corrosion rate of magnesium. A multistep process that combines metal foam production and injection molding was developed to create a hybrid composite structure that is topologically ordered in all three dimensions. Preliminary investigations of the mechanical properties and corrosion behavior exhibited by the hybrid Mg-polymer composite structures suggest a new potential approach to the development of Mg-based biomedical devices.

  10. Long-range gene flow and the effects of climatic and ecological factors on genetic structuring in a large, solitary carnivore: the Eurasian lynx.

    Directory of Open Access Journals (Sweden)

    Mirosław Ratkiewicz

    Full Text Available Due to their high mobility, large terrestrial predators are potentially capable of maintaining high connectivity, and therefore low genetic differentiation among populations. However, previous molecular studies have provided contradictory findings in relation to this. To elucidate patterns of genetic structure in large carnivores, we studied the genetic variability of the Eurasian lynx, Lynx lynx throughout north-eastern Europe using microsatellite, mitochondrial DNA control region and Y chromosome-linked markers. Using SAMOVA we found analogous patterns of genetic structure based on both mtDNA and microsatellites, which coincided with a relatively little evidence for male-biased dispersal. No polymorphism for the cytochrome b and ATP6 mtDNA genes and Y chromosome-linked markers were found. Lynx inhabiting a large area encompassing Finland, the Baltic countries and western Russia formed a single genetic unit, while some marginal populations were clearly divergent from others. The existence of a migration corridor was suggested to correspond with distribution of continuous forest cover. The lowest variability (in both markers was found in lynx from Norway and Białowieża Primeval Forest (BPF, which coincided with a recent demographic bottleneck (Norway or high habitat fragmentation (BPF. The Carpathian population, being monomorphic for the control region, showed relatively high microsatellite diversity, suggesting the effect of a past bottleneck (e.g. during Last Glacial Maximum on its present genetic composition. Genetic structuring for the mtDNA control region was best explained by latitude and snow cover depth. Microsatellite structuring correlated with the lynx's main prey, especially the proportion of red deer (Cervus elaphus in its diet. Eurasian lynx are capable of maintaining panmictic populations across eastern Europe unless they are severely limited by habitat continuity or a reduction in numbers. Different correlations of mtDNA and

  11. Solitary midbrain metastasis.

    Science.gov (United States)

    Ongerboer de Visser, B W; Moffie, D

    1981-01-01

    The available clinical and pathological data of 5 cases with solitary midbrain metastasis including 2 of the present study are reviewed. Progressive dementia occurred in one case and mild dementia in another who also developed ocular symptoms. Ocular symptoms with sensory and coordination disturbances were seen in one, and only ocular symptoms in another case. Right-sided hemiplegia of 5 years duration occurred in the remaining case. Survival in tegmentum lesions is short.

  12. Peptide Toxins in Solitary Wasp Venoms

    Science.gov (United States)

    Konno, Katsuhiro; Kazuma, Kohei; Nihei, Ken-ichi

    2016-01-01

    Solitary wasps paralyze insects or spiders with stinging venom and feed the paralyzed preys to their larva. Accordingly, the venoms should contain a variety of constituents acting on nervous systems. However, only a few solitary wasp venoms have been chemically studied despite thousands of species inhabiting the planet. We have surveyed bioactive substances in solitary wasp venoms found in Japan and discovered a variety of novel bioactive peptides. Pompilidotoxins (PMTXs), in the venoms of the pompilid wasps Anoplius samariensis and Batozonellus maculifrons, are small peptides consisting of 13 amino acids without a disulfide bond. PMTXs slowed Na+ channel inactivation, in particular against neuronal type Na+ channels, and were rather selective to the Nav1.6 channel. Mastoparan-like cytolytic and antimicrobial peptides are the major components of eumenine wasp venoms. They are rich in hydrophobic and basic amino acids, adopting a α-helical secondary structure, and showing mast cell degranulating, antimicrobial and hemolytic activities. The venom of the spider wasp Cyphononyx fulvognathus contained four bradykinin-related peptides. They are hyperalgesic and, dependent on the structure, differently associated with B1 or B2 receptors. Further survey led to the isolation of leucomyosuppressin-like FMRFamide peptides from the venoms of the digger wasps Sphex argentatus and Isodontia harmandi. These results of peptide toxins in solitary wasp venoms from our studies are summarized. PMID:27096870

  13. Peptide Toxins in Solitary Wasp Venoms

    Directory of Open Access Journals (Sweden)

    Katsuhiro Konno

    2016-04-01

    Full Text Available Solitary wasps paralyze insects or spiders with stinging venom and feed the paralyzed preys to their larva. Accordingly, the venoms should contain a variety of constituents acting on nervous systems. However, only a few solitary wasp venoms have been chemically studied despite thousands of species inhabiting the planet. We have surveyed bioactive substances in solitary wasp venoms found in Japan and discovered a variety of novel bioactive peptides. Pompilidotoxins (PMTXs, in the venoms of the pompilid wasps Anoplius samariensis and Batozonellus maculifrons, are small peptides consisting of 13 amino acids without a disulfide bond. PMTXs slowed Na+ channel inactivation, in particular against neuronal type Na+ channels, and were rather selective to the Nav1.6 channel. Mastoparan-like cytolytic and antimicrobial peptides are the major components of eumenine wasp venoms. They are rich in hydrophobic and basic amino acids, adopting a α-helical secondary structure, and showing mast cell degranulating, antimicrobial and hemolytic activities. The venom of the spider wasp Cyphononyx fulvognathus contained four bradykinin-related peptides. They are hyperalgesic and, dependent on the structure, differently associated with B1 or B2 receptors. Further survey led to the isolation of leucomyosuppressin-like FMRFamide peptides from the venoms of the digger wasps Sphex argentatus and Isodontia harmandi. These results of peptide toxins in solitary wasp venoms from our studies are summarized.

  14. Structural properties of maize hybrids established by infrared spectra

    Directory of Open Access Journals (Sweden)

    Radenović Čedomir N.

    2015-01-01

    Full Text Available This paper discusses the application of the infrared (IR spectroscopy method for determination of structural properties of maize hybrid grains. The IR spectrum of maize grain has been registered in the following hybrids: ZP 341, ZP 434 and ZP 505. The existence of spectral bands varying in both number and intensity, as well as their shape, frequency and kinetics have been determined. They have been determined by valence oscillations and deformation oscillations of the following organic compounds: alkanes, alkenes, alkynes, amides, alcohols, ethers, carboxylic acids, esters and aldehydes and ketones, characteristic for biogenic compounds such as carbohydrates, proteins and lipids. In this way, possible changes in the grain structure of observed maize hybrids could be detected.

  15. Solitary intraosseous neurofibroma of mandible.

    Directory of Open Access Journals (Sweden)

    Vivek N

    2006-01-01

    Full Text Available Solitary intraosseous neurofibroma is a rare benign non-odontogenic tumor. Although neurofibromas occur predominantly as a feature of neurofibromatosis affecting the soft tissue, a few cases of solitary intraosseous neurofibromas of the jaw have been reported. We herewith report a case of solitary intraosseous neurofibroma of mandible in a middle-aged woman with a discussion on its clinical, radiological, and histopathological presentation along with review of cases.

  16. Hybrid Spintronic Structures With Magnetic Oxides and Heusler Alloys

    DEFF Research Database (Denmark)

    Xu, Y. B.; Hassan, S. S. A.; Wong, P. K. J.;

    2008-01-01

    Hybrid spintronic structures, integrating half-metallic magnetic oxides and Heusler alloys with their predicted high spin polarization, are important for the development of second-generation spintronics with high-efficient spin injection. We have synthesized epitaxial magnetic oxide Fe3O4 on GaAs...

  17. Exploratory Topology Modelling of Form-Active Hybrid Structures

    DEFF Research Database (Denmark)

    Holden Deleuran, Anders; Pauly, Mark; Tamke, Martin;

    2016-01-01

    The development of novel form-active hybrid structures (FAHS) is impeded by a lack of modelling tools that allow for exploratory topology modelling of shaped assemblies. We present a flexible and real-time computational design modelling pipeline developed for the exploratory modelling of FAHS tha...

  18. Hybridized Nano-Structure Composed of Metal and Polydiacetylene

    Institute of Scientific and Technical Information of China (English)

    H. Oikawa; A. Masuhara; T. Onodera; H. Kasai; H. Nakanishi

    2005-01-01

    @@ 1Introduction Polydiacetylene (PDA) is one of the promising candidates for organic third-order nonlinear optical (NLO) material, due to fast optical responsibility and easy processability in comparison with semiconductors etc. The magnitude of NLO property, however, is not still sufficient for the devices applications. Neeves, et al[1] theoretically predicted the enhancement of NLO property for core-shell type hybridized nanocrystal (NC) composed of PDA and metal. In the present study, we have prepared the two kinds of core-shell type hybridized nano-structure, and investigated their optical properties.

  19. Weak bond detection in composites using highly nonlinear solitary waves

    Science.gov (United States)

    Singhal, Taru; Kim, Eunho; Kim, Tae-Yeon; Yang, Jinkyu

    2017-05-01

    We experimentally investigate a diagnostic technique for identifying a weak bond in composites using highly nonlinear solitary waves (HNSWs). We set up a one-dimensional chain of granular crystals, consisting of spherical particles with nonlinear interactions, to generate HNSWs. These solitary wave packets are transmitted into an inspection area of composites by making a direct contact with the chain. We demonstrate that a strong type of solitary waves injected to the weak bond area can break the weak bond of laminates, thereby causing delamination. Then, to identify the creation of the delamination, we transmit a weak type of solitary waves by employing the same apparatus, and measure the solitary waves reflected from the specimens. By analyzing these reflected solitary waves, we differentiate the weak bond samples with the pristine bond ones in an efficient and fast manner. The diagnostic results based on the proposed method are compared with the strength and energy release rate at bond interfaces, which are measured via standard testing methods such as three point bending and end notched flexure tests. This study shows the potential of solitary wave-based detection of weak bonds for hot spot monitoring of composite-based structures.

  20. From solitary wave to traveling surge

    Institute of Scientific and Technical Information of China (English)

    宋礼庭

    1995-01-01

    The solution of kinetic Alfven wave under action of anomalous resistance has two branches: the slow wave, VPstructure of Alfven traveling surge and the fast wave VP>VA cosθ will be in a wave-broken state. Such traveling surge structure is a typical self-organization phenomenon and its wave form is determined by parameter β which represents the magnitude of resistance. High β leads to shock-like structure and low β to the appearance of some solitary waves in front of the shock. According to the study on solitary wave, shock wave and traveling surge in conjunction with self-organization of nonlinear dynamics, a general definition of wave can be given.

  1. Calculation of hybrid joints used in modern aerospace structures

    Directory of Open Access Journals (Sweden)

    Marcel STERE

    2011-12-01

    Full Text Available The state – of - the art of aeronautical structures show that parts are manufactured and subsequently assembled with the use of fasteners and/ or bonding. Adhesive bonding is a key technology to low weight, high fatigue resistance, robustness and an attractive design for cost structures.The paper results resolve significant problems for two groups of end-users:1 for the aerospace design office: a robust procedure for the design of the hybrid joint structural components;2 for the aeronautical repair centres: a useful procedure for structural design and analysis with significant cost savings.

  2. Double Sided Si(Ge)/Sapphire/III-Nitride Hybrid Structure

    Science.gov (United States)

    Park, Yeonjoon (Inventor); Choi, Sang Hyouk (Inventor)

    2016-01-01

    One aspect of the present invention is a double sided hybrid crystal structure including a trigonal Sapphire wafer containing a (0001) C-plane and having front and rear sides. The Sapphire wafer is substantially transparent to light in the visible and infrared spectra, and also provides insulation with respect to electromagnetic radio frequency noise. A layer of crystalline Si material having a cubic diamond structure aligned with the cubic direction on the (0001) C-plane and strained as rhombohedron to thereby enable continuous integration of a selected (SiGe) device onto the rear side of the Sapphire wafer. The double sided hybrid crystal structure further includes an integrated III-Nitride crystalline layer on the front side of the Sapphire wafer that enables continuous integration of a selected III-Nitride device on the front side of the Sapphire wafer.

  3. Brain anatomical structure segmentation by hybrid discriminative/generative models.

    Science.gov (United States)

    Tu, Z; Narr, K L; Dollar, P; Dinov, I; Thompson, P M; Toga, A W

    2008-04-01

    In this paper, a hybrid discriminative/generative model for brain anatomical structure segmentation is proposed. The learning aspect of the approach is emphasized. In the discriminative appearance models, various cues such as intensity and curvatures are combined to locally capture the complex appearances of different anatomical structures. A probabilistic boosting tree (PBT) framework is adopted to learn multiclass discriminative models that combine hundreds of features across different scales. On the generative model side, both global and local shape models are used to capture the shape information about each anatomical structure. The parameters to combine the discriminative appearance and generative shape models are also automatically learned. Thus, low-level and high-level information is learned and integrated in a hybrid model. Segmentations are obtained by minimizing an energy function associated with the proposed hybrid model. Finally, a grid-face structure is designed to explicitly represent the 3-D region topology. This representation handles an arbitrary number of regions and facilitates fast surface evolution. Our system was trained and tested on a set of 3-D magnetic resonance imaging (MRI) volumes and the results obtained are encouraging.

  4. Hybrid Optimization in the Design of Reciprocal Structures

    DEFF Research Database (Denmark)

    Parigi, Dario; Kirkegaard, Poul Henning; Sassone, Mario

    2012-01-01

    that explore the global domain of solutions as genetic algorithms (GAs). The benchmark tests show that when the control on the topology is required the best result is obtained by a hybrid approach that combines the global search of the GA with the local search of a GB algorithm. The optimization method......The paper presents a method to generate the geometry of reciprocal structures by means of a hybrid optimization procedure. The geometry of reciprocal structures where elements are sitting on the top or in the bottom of each other is extremely difficult to predict because of the non....... In this paper it is shown that the geometrically compatible position of the elements could be determined by local search algorithm gradient-based (GB). However the control on which bar sit on the top or in the bottom at each connection can be regarded as a topological problem and require the use of algorithms...

  5. In Situ Production of Graphene-Fiber Hybrid Structures

    DEFF Research Database (Denmark)

    Akia, Mandana; Cremar, Lee; Chipara, Mircea

    2017-01-01

    We report a scalable method to obtain a new material where large graphene sheets form webs linking carbon fibers. Film-fiber hybrid nonwoven mats are formed during fiber processing and converted to carbon structures after a simple thermal treatment. This contrasts with multistep methods that atte......We report a scalable method to obtain a new material where large graphene sheets form webs linking carbon fibers. Film-fiber hybrid nonwoven mats are formed during fiber processing and converted to carbon structures after a simple thermal treatment. This contrasts with multistep methods...... a capillarity effect that promoted the formation of thin veils, which become graphene sheets upon dehydration by sulfuric acid vapor followed by carbonization (at relatively low temperatures, below 800 °C). These veils extend over several micrometers within the pores of the fiber network, and consist...

  6. Hybrid proper orthogonal decomposition formulation for linear structural dynamics

    Science.gov (United States)

    Placzek, A.; Tran, D.-M.; Ohayon, R.

    2008-12-01

    Hybrid proper orthogonal decomposition (PODh) formulation is a POD-based reduced-order modeling method where the continuous equation of the physical system is projected on the POD modes obtained from a discrete model of the system. The aim of this paper is to evaluate the hybrid POD formulation and to compare it with other POD formulations on the simple case of a linear elastic rod subject to prescribed displacements in the perspective of building reduced-order models for coupled fluid-structure systems in the future. In the first part of the paper, the hybrid POD is compared to two other formulations for the response to an initial condition: an approach based on the discrete finite elements equation of the rod called the discrete POD (PODd), and an analytical approach using the exact solution of the problem and consequently called the analytical POD (PODa). This first step is useful to ensure that the PODh performs well with respect to the other formulations. The PODh is therefore used afterwards for the forced motion response where a displacement is imposed at the free end of the rod. The main contribution of this paper lies in the comparison of three techniques used to take into account the non-homogeneous Dirichlet boundary condition with the hybrid POD: the first method relies on control functions, the second on the penalty method and the third on Lagrange multipliers. Finally, the robustness of the hybrid POD is investigated on two examples involving firstly the introduction of structural damping and secondly a nonlinear force applied at the free end of the rod.

  7. Hybrid competitive strategies, organizational structure, and firm performance

    OpenAIRE

    Pertusa Ortega, Eva María

    2008-01-01

    Comunicación presentada en SMS 28th Annual International Conference, Cologne, Germany, October 12-15, 2008. This paper analyzes the internal characteristics of organizational structure which have an influence on the development of hybrid competitive strategies and their link to firm performance. The study examines a sample of large Spanish firms belonging to different sectors by means of the Partial Least Squares (PLS) technique, using formative dimensions for competitive strategy and orga...

  8. Polarized light source based on graphene-nanoribbon hybrid structure

    Science.gov (United States)

    Xu, Pengfei; Zhang, Han; Qian, Haoliang; Chen, Bigeng; Jiang, Xiaoshun; Wu, Yuanpeng; Liu, Xiaowei; Liu, Xu; Yang, Qing

    2017-07-01

    Nanoscale light source is the key element for on-chip integrated optical communication system. As an important property of light source, polarization can be exploited to improve the information capacity of optical communication and the sensitivity of optical sensing. We demonstrate a novel TE-polarized light source based on graphene-nanoribbon (G-NR) hybrid structure. Thanks to the polarizing dependent absorption along graphene layer, the random polarized emission of nanoribbon (NR) can be transferred into the same TE polarization. In addition, lasing action in G-NR hybrid structure is also investigated. We attribute the polarization control to the differential attenuation of electromagnetic modes in graphene. Our simulation revealed electromagnetic field distribution and far field polar images of TE and TM modes in nanoribbon, which is consistent with experimental results. The compact G-NR hybrid structure light source offers a new way to realize the polarization controllable nanoscale light source and facilitate the practical applications of nanowire or nanoribbon light source.

  9. Nanodevices based on Membrane-Carbon Nanotube Hybrid Structures

    Science.gov (United States)

    Jin, Hye Jun; Kim, Tae Hyun; Namgung, Seon; Hong, Seunghun; Lee, Sang Hun; Park, Tai Hyun

    2010-03-01

    Proteins in cell membrane have been drawing attention due to their versatile functionalities such as ion transfer for neuronal activity and selective binding for sensory systems. However, it is still very difficult to manipulate and study those proteins because they easily lose their functionalities without lipid membranes. We developed a method to coat lipid membranes containing various functional membrane proteins on single-walled carbon nanotube (swCNT)-based field effect transistors (FETs). In this hybrid structure, the activity of membrane proteins can be monitored by underlying swCNT-FETs, allowing us to easily study the functionalities of membrane proteins. Furthermore, we built advanced devices based on these hybrid structures. For an example, we coated lipid membrane containing `olfactory receptors' on swCNT-FETs, resulting in `bioelectric nose' systems. The bioelectric nose system had high sensitivity and human nose-like selectivity to odorant molecules. This talk will also discuss about the future prospect of these membrane-CNT hybrid structures.

  10. Development of Hybrid Product Breakdown Structure for NASA Ground Systems

    Science.gov (United States)

    Monaghan, Mark W.; Henry, Robert J.

    2013-01-01

    The Product Breakdown Structure is traditionally a method of identification of the products of a project in a tree structure. It is a tool used to assess, plan, document, and display the equipment requirements for a project. It is part of a product based planning technique, and attempts to break down all components of a project in as much detail as possible, so that nothing is overlooked. The PBS for ground systems at the Kennedy Space Center is being developed to encompass the traditional requirements including the alignment of facility, systems, and components to the organizational hierarchy. The Ground Operations Product Breakdown Structure is a hybrid in nature in that some aspects of a work breakdown structure will be incorporated and merged with the Architecture Concept of Operations, Master Subsystem List, customer interface, and assigned management responsibility. The Ground Operations Product Breakdown Structure needs to be able to identify the flexibility of support differing customers (internal and external) usage of ground support equipment within the Kennedy Space Center launch and processing complex. The development of the Product Breakdown Structure is an iterative activity Initially documenting the organization hierarchy structure and relationships. The Product Breakdown Structure identifies the linkage between the customer program requirements, allocation of system resources, development of design goals, and identification logistics products. As the Product Breakdown Structure progresses the incorporation of the results of requirement planning for the customer occurs identifying facility needs and systems. The mature Product Breakdown Structure is baselined with a hierarchical drawing, the Product Breakdown Structure database, and an associated document identifying the verification of the data through the life cycle of the program/product line. This paper will document, demonstrate, and identify key aspects of the life cycle of a Hybrid Product

  11. Solitary eyelid schwannoma

    Directory of Open Access Journals (Sweden)

    Renu M Magdum

    2014-01-01

    Full Text Available Schwannomas are rare benign tumors arising from Schwann cells of peripheral nerves that form the neural sheath. While there have been reports of such tumors in the orbit, solitary schwannomas arising from the eyelids are very rare. There are reports of schwannomas being erroneously diagnosed as chalazion, inclusion cysts or even eyelid malignancy. We are reporting a case of a 20-year-old female who presented with a painless, non-tender, slow-growing mass in the upper eyelid of the right eye. The external appearance of the mass was suggestive of an implantation cyst of the eyelid and it could be completely excised as it had a well-defined capsule. Histopathological examination showed characteristic hypercellular and hypocellular areas with fusiform nuclei that tended to form palisades. The purpose of reporting this case of schwannoma in a young female is to recommend the inclusion of this entity as a differential diagnosis of well-defined lid tumors.

  12. Solitary Polypoid Laryngeal Xanthoma

    Directory of Open Access Journals (Sweden)

    Francisco Vera-Sempere

    2013-01-01

    Full Text Available We report the case of a 51-year-old male smoker with diabetes mellitus and hyperlipidaemia and a long history of human immunodeficiency virus (HIV/hepatitis C virus (HCV infection treated with various antiretroviral regimes, who was referred to the otolaryngology department with progressive dysphonia. Fibre-optic laryngoscopy showed a solitary, yellowish-white pedunculated polyp on the anterior third of the left cord, with no other abnormality. Pathological analysis revealed a polypoid laryngeal xanthoma that was immunoreactive against CD68, perilipin, and adipophilin. This unusual laryngeal lesion in the clinical context of our patient suggests a possible role of antiretroviral treatment in the pathogenesis of these xanthomas.

  13. Solitary fibrous tumor

    Directory of Open Access Journals (Sweden)

    Manlio Mencoboni

    2010-12-01

    Full Text Available Solitary fibrous tumor (SFT is a rare mesenchymal neoplasm which may be found everywhere in the body. It is now distinguished into two forms, pleural and extrapleural, which morphologically resemble each other. Abdomi­nal localizations are quite rare, with 10 cases only reported in bladder; rarely they can be source of paraneoplastic syndromes (i.e., hypoglycemia secondary to insulin-like growth factor. In April 2006 a 74-year-old white male presented with chills, diaphoresis and acute abdominal pain with hematuria. At admission in emergency he underwent an abdominal X-ray (no pathological findings and an ultrasound examination of the kidneys and urinary tract, which revealed a pelvic hyperechogenic neoformation measuring approximately 10¥8¥7 cm, compressing the bladder. Blood chemistry at admission revealed only a mild neutrophilic leucocytosis (WBC 16600, N 80%, L 11%, elevated fibrinogen and ESR, and hypoglycemia (38 mg/dL. Macro­scopic hematuria was evident, while urinocolture was negative. Contrast enhanced CT scan of the abdomen and pelvic region revealed a large round neoformation dislocating the bladder, with an evident contrast-enhanced periphery and a central necrotic area. Continuous infusion of glucose 5% solution was necessary in order to maintain blood glucose levels above 50 mg/dL. The patient underwent complete surgical resection of an ovoidal mass coated by adipose tissue, with well delimited margins; histological findings were consistent with solitary fibrous tumor (SFT. Hypoglycemia resolved completely with removal of the growth. In this case report we describe a SFT growing in the bladder, a quite rare localization, which presented a unique hypoglycemia. In contrast to the majority of cases reported in the literature, the behavior of this SFT was not aggressive, and, since the patient is still alive, surgical resection was considered conclusive.

  14. Hybrid open public space of landscape elements and built structure

    Directory of Open Access Journals (Sweden)

    Gordana Bence

    2008-01-01

    Full Text Available The trend today in the cities in Europe and elsewhere is in combining landscape elements, built structure and different uses into a complex urban structure. Physical and program interweaving of landscape elements and built structure enables the consumers daily practice of leisure programs – relaxation, recreation and experiencing other cultural, educational and social events in the public green space. On the basis of determinate social changes and new approaches in urban planning practice, analyses of architectural and urban case studies from the point of view of integrating the landscape elements into the urban structure, the article defines the phenomenon of hybrid open public space and proposes methodical guidelines for the planning.

  15. Localization and solitary waves in solid mechanics

    CERN Document Server

    Champneys, A R; Thompson, J M T

    1999-01-01

    This book is a collection of recent reprints and new material on fundamentally nonlinear problems in structural systems which demonstrate localized responses to continuous inputs. It has two intended audiences. For mathematicians and physicists it should provide useful new insights into a classical yet rapidly developing area of application of the rich subject of dynamical systems theory. For workers in structural and solid mechanics it introduces a new methodology for dealing with structural localization and the related topic of the generation of solitary waves. Applications range from classi

  16. Ants exhibit asymmetric hybridization in a mosaic hybrid zone.

    Science.gov (United States)

    Purcell, Jessica; Zahnd, Sacha; Athanasiades, Anouk; Türler, Rebecca; Chapuisat, Michel; Brelsford, Alan

    2016-10-01

    Research on hybridization between species provides unparalleled insights into the pre- and postzygotic isolating mechanisms that drive speciation. In social organisms, colony-level incompatibilities may provide additional reproductive barriers not present in solitary species, and hybrid zones offer an opportunity to identify these barriers. Here, we use genotyping-by-sequencing to sequence hundreds of markers in a hybrid zone between two socially polymorphic ant species, Formica selysi and Formica cinerea. We characterize the zone, determine the frequency of hybrid workers, infer whether hybrid queens or males are produced and investigate whether hybridization is influenced by colony social organization. We also compare cuticular hydrocarbon profiles and aggression levels between the two species. The hybrid zone exhibits a mosaic structure. The asymmetric distribution of hybrids skewed towards F. cinerea suggests a pattern of unidirectional nuclear gene flow from F. selysi into F. cinerea. The occurrence of backcrossed individuals indicates that hybrid queens and/or males are fertile, and the presence of the F. cinerea mitochondrial haplotype in 97% of hybrids shows that successful F1 hybrids will generally have F. cinerea mothers and F. selysi fathers. We found no evidence that social organization contributes to speciation, because hybrids occur in both single-queen and multiple-queen colonies. Strongly differentiated cuticular hydrocarbon profiles and heightened interspecific aggression further reveal that species recognition cues are both present and perceived. The discovery of fertile hybrids and asymmetrical gene flow is unusual in ants, and this hybrid zone will therefore provide an ideal system with which to investigate speciation in social insects.

  17. Structural and electronic properties of hybrid silicon-germanium nanosheets

    Directory of Open Access Journals (Sweden)

    F. L. Pérez Sánchez

    2014-12-01

    Full Text Available Using first principles molecular calculations, based on the Density Functional Theory (DFT, structural and electronic properties of hybrid graphene—like silicon—germanium circular nanosheets of hexagonal symmetry are investigated. The exchange—correlation functional of Perdew—Wang (PW in the local spin density approximation (LSDA based on the pseudopotentials of Dolg—Bergnre is applied. The finite extension nanosheets are represented by the CnHm—like cluster model with mono—hydrogenated armchair edges. Changes of the physicochemical properties were analyzed to learn on the chemical composition. We have obtained that the corrugation of the hybrid nanosheets is maintained (with respect to the pristine nanosheets of Ge and Si and is more pronounced when there is a high percentage of germanium. Moreover, hybrid nanosheets have ionic bonds (polarity in the interval from 0.18 to 0.77 D and exhibit a semimetal behavior. Three types of chemical compositions are considered: 1 the one—one relationship, 2 formation of Ge dimers and 3 formation of Ge hexagons. In each case it is observed an increase in the chemical reactivity. Finally, analyzing the work function we conclude that in cases 1 and 2 the chemical compositions improve the efficiency of the field emission and thereby they could expand the scope of nanotechnology applications.

  18. Transition from Solitons to Solitary Waves in the Fermi-Pasta-Ulam Lattice

    CERN Document Server

    Wen, Zhenying; Wei, Nian

    2016-01-01

    In this paper, we study the smooth transition from solitons to solitary waves in localization, relation between energy and velocity, propagation and scattering property in the Fermi-Pasta-Ulam lattice analytically and numerically. A soliton is a very stable solitary wave that retains its permanent structure after interacting with other solitary waves. A soliton exists when the energy is small, and it becomes a solitary wave when the energy increases to the threshold. The transition could help to understand the distinctly different heat conduction behaviors of the Fermi-Pasta-Ulam lattice at low and high temperature.

  19. Calculation and analysis of solitary waves and kinks in elastic tubes

    OpenAIRE

    2013-01-01

    The paper is devoted to analysis of different models that describe waves in fluid-filled and gas-filled elastic tubes and development of methods of calculation and numerical analysis of solutions with solitary waves and kinks for these models. Membrane model and plate model are used for tube. Two types of solitary waves are found. One-parametric families are stable and may be used as shock structures. Null-parametric solitary waves are unstable. The process of split of such solitary waves is ...

  20. Improved hybrid optimization algorithm for 3D protein structure prediction.

    Science.gov (United States)

    Zhou, Changjun; Hou, Caixia; Wei, Xiaopeng; Zhang, Qiang

    2014-07-01

    A new improved hybrid optimization algorithm - PGATS algorithm, which is based on toy off-lattice model, is presented for dealing with three-dimensional protein structure prediction problems. The algorithm combines the particle swarm optimization (PSO), genetic algorithm (GA), and tabu search (TS) algorithms. Otherwise, we also take some different improved strategies. The factor of stochastic disturbance is joined in the particle swarm optimization to improve the search ability; the operations of crossover and mutation that are in the genetic algorithm are changed to a kind of random liner method; at last tabu search algorithm is improved by appending a mutation operator. Through the combination of a variety of strategies and algorithms, the protein structure prediction (PSP) in a 3D off-lattice model is achieved. The PSP problem is an NP-hard problem, but the problem can be attributed to a global optimization problem of multi-extremum and multi-parameters. This is the theoretical principle of the hybrid optimization algorithm that is proposed in this paper. The algorithm combines local search and global search, which overcomes the shortcoming of a single algorithm, giving full play to the advantage of each algorithm. In the current universal standard sequences, Fibonacci sequences and real protein sequences are certified. Experiments show that the proposed new method outperforms single algorithms on the accuracy of calculating the protein sequence energy value, which is proved to be an effective way to predict the structure of proteins.

  1. Healing Temperature of Hybrid Structures Based on Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    赵中伟; 陈志华; 刘红波

    2016-01-01

    The healing temperature of suspen-dome with stacked arches(SDSA)and arch-supported single-layer lattice shell structures was investigated based on the genetic algorithm. The temperature field of arch under solar radiation was derived by FLUENT to investigate the influence of solar radiation on the determination of the healing temperature. Moreover, a multi-scale model was established to apply the complex temperature field under solar radiation. The change in the mechanical response of these two kinds of structures with the healing temperature was discussed. It can be concluded that solar radiation has great influence on the healing temperature, and the genetic algorithm can be effectively used in the optimization of the healing temperature for hybrid structures.

  2. Structural and Morphological Investigation for Water-Processed Graphene Oxide/Single-Walled Carbon Nanotubes Hybrids

    Science.gov (United States)

    Muda, M. R.; Ramli, M. M.; Mat Isa, S. S.; Halin, D. S. C.; Talip, L. F. A.; Mazelan, N. S.; Anhar, N. A. M.; Danial, N. A.

    2017-06-01

    New group of materials derived from hybridization of single walled carbon nanotubes (SWCNTs) and graphene oxide (GO) which resulting novel three dimensional (3D) materials generates an outstanding properties compared to corresponding SWCNTs and GO/Graphene. In this paper, we describe a simple approach using water processing method to develop integrated rGO/GO-SWCNT hybrids with different hybrid ratios. The hybrid ratios were varied into three divided ratio and the results were compared between pristine SWCNTs and GO in order to investigate the structural density and morphology of these carbonaceous materials. With an optimized ratio of rGO/GO-SWCNT, the hybrid shows a well-organized hybrid film structures with less defects density sites. The optimized mixture ratio emphasized the important of both rGO and SWCNTs in the hybrid structures. Morphological structural and defects density degrees were examined by Field Emission Scanning Electron Microscopy (FESEM) and Raman spectroscopy.

  3. Structural Organization of Enzymes of the Phenylacetate Catabolic Hybrid Pathway

    Directory of Open Access Journals (Sweden)

    Andrey M. Grishin

    2015-06-01

    Full Text Available Aromatic compounds are the second most abundant class of molecules on the earth and frequent environmental pollutants. They are difficult to metabolize due to an inert chemical structure, and of all living organisms, only microbes have evolved biochemical pathways that can open an aromatic ring and catabolize thus formed organic molecules. In bacterial genomes, the phenylacetate (PA utilization pathway is abundant and represents the central route for degradation of a variety of organic compounds, whose degradation reactions converge at this pathway. The PA pathway is a hybrid pathway and combines the dual features of aerobic metabolism, i.e., usage of both oxygen to open the aromatic ring and of anaerobic metabolism—coenzyme A derivatization of PA. This allows the degradation process to be adapted to fluctuating oxygen conditions. In this review we focus on the structural and functional aspects of enzymes and their complexes involved in the PA degradation by the catabolic hybrid pathway. We discuss the ability of the central PaaABCE monooxygenase to reversibly oxygenate PA, the controlling mechanisms of epoxide concentration by the pathway enzymes, and the similarity of the PA utilization pathway to the benzoate utilization Box pathway and β-oxidation of fatty acids.

  4. Structural Organization of Enzymes of the Phenylacetate Catabolic Hybrid Pathway.

    Science.gov (United States)

    Grishin, Andrey M; Cygler, Miroslaw

    2015-06-12

    Aromatic compounds are the second most abundant class of molecules on the earth and frequent environmental pollutants. They are difficult to metabolize due to an inert chemical structure, and of all living organisms, only microbes have evolved biochemical pathways that can open an aromatic ring and catabolize thus formed organic molecules. In bacterial genomes, the phenylacetate (PA) utilization pathway is abundant and represents the central route for degradation of a variety of organic compounds, whose degradation reactions converge at this pathway. The PA pathway is a hybrid pathway and combines the dual features of aerobic metabolism, i.e., usage of both oxygen to open the aromatic ring and of anaerobic metabolism-coenzyme A derivatization of PA. This allows the degradation process to be adapted to fluctuating oxygen conditions. In this review we focus on the structural and functional aspects of enzymes and their complexes involved in the PA degradation by the catabolic hybrid pathway. We discuss the ability of the central PaaABCE monooxygenase to reversibly oxygenate PA, the controlling mechanisms of epoxide concentration by the pathway enzymes, and the similarity of the PA utilization pathway to the benzoate utilization Box pathway and β-oxidation of fatty acids.

  5. Structure of Solvent-Free Nanoparticle−Organic Hybrid Materials

    KAUST Repository

    Yu, Hsiu-Yu

    2010-11-16

    We derive the radial distribution function and the static structure factor for the particles in model nanoparticleorganic hybrid materials composed of nanoparticles and attached oligomeric chains in the absence of an intervening solvent. The assumption that the oligomers form an incompressible fluid of bead-chains attached to the particles that is at equilibrium for a given particle configuration allows us to apply a density functional theory for determining the equilibrium configuration of oligomers as well as the distribution function of the particles. A quasi-analytic solution is facilitated by a regular perturbation analysis valid when the oligomer radius of gyration R g is much greater than the particle radius a. The results show that the constraint that each particle carries its own share of the fluid attached to itself yields a static structure factor that approaches zero as the wavenumber approaches zero. This result indicates that each particle excludes exactly one other particle from its neighborhood. © 2010 American Chemical Society.

  6. Preparation of Ionic Silsesquioxanes with Regular Structures and Their Hybridization

    Directory of Open Access Journals (Sweden)

    Yoshiro Kaneko

    2012-01-01

    Full Text Available This paper deals with our recent studies on the preparation of ionic silsesquioxanes (SQs with regular structures. Cationic ladder-like polySQs (PSQs with hexagonally stacked structures were successfully prepared by the sol-gel reactions of amino group-containing organotrialkoxysilanes in strong acid aqueous solutions. Self-organization of an ion pair (a salt prepared from the amino group in the organotrialkoxysilane and an acid is the key factor for the formation of such regular structures of the PSQs. It is also reported that the control of the conformational structure of the PSQs was performed by the introduction of the chiral moieties. In addition, we investigated the correlation between the of acid-catalysts and the structures of SQs prepared by the hydrolytic condensation of amino group-containing organotrialkoxysilane, that is, the use of the superacid aqueous solution resulted in the formation of cage-like octaSQ, while the ladder-like PSQs with hexagonally stacked structures were formed from the strong acid aqueous solutions under the same reaction conditions. Furthermore, anion-exchange behaviors of the cationic ladder-like PSQ were investigated with various organic and inorganic compounds, such as anionic surfactants, a polymer, and layered clay minerals, to obtain the functional hybrid materials.

  7. Static and Dynamic Analyses of Long-Span Spatial Steel-Cable-Membrane Hybrid Structures

    Institute of Scientific and Technical Information of China (English)

    丁阳; 彭翼; 李忠献

    2003-01-01

    With the increment of the complexity of structural systems and the span of spatial structures, the interactions between parts of the structures, especially between some flexible substructures, become too complex to be analyzed clearly. In this paper, taking an actual gymnasium of a long-span spatial steel-cable-membrane hybrid structure as the calculation model, the static and dynamic analyses of the hybrid structures are performed by employing the global analysis of the whole hybrid structure and the substructural analysis of the truss arch substructure, the cable-membrane substructure, etc. In addition, the comparison of stresses and displacements of structural members in the global and substructural analyses is made. The numerical results show that serious errors exist in the substructural analysis of the hybrid structure, and the global analysis is necessary for the hybrid structure under the excitation of static loads and seismic loads.

  8. Hybrid density functional theory band structure engineering in hematite.

    Science.gov (United States)

    Pozun, Zachary D; Henkelman, Graeme

    2011-06-14

    We present a hybrid density functional theory (DFT) study of doping effects in α-Fe(2)O(3), hematite. Standard DFT underestimates the band gap by roughly 75% and incorrectly identifies hematite as a Mott-Hubbard insulator. Hybrid DFT accurately predicts the proper structural, magnetic, and electronic properties of hematite and, unlike the DFT+U method, does not contain d-electron specific empirical parameters. We find that using a screened functional that smoothly transitions from 12% exact exchange at short ranges to standard DFT at long range accurately reproduces the experimental band gap and other material properties. We then show that the antiferromagnetic symmetry in the pure α-Fe(2)O(3) crystal is broken by all dopants and that the ligand field theory correctly predicts local magnetic moments on the dopants. We characterize the resulting band gaps for hematite doped by transition metals and the p-block post-transition metals. The specific case of Pd doping is investigated in order to correlate calculated doping energies and optical properties with experimentally observed photocatalytic behavior.

  9. Assortative mating and the maintenance of population structure in a natural hybrid zone.

    Science.gov (United States)

    Culumber, Zachary W; Ochoa, Olivia M; Rosenthal, Gil G

    2014-08-01

    Understanding the factors that give rise to natural hybrid zones and govern their dynamics and structure is important to predicting the evolutionary consequences of hybridization. Here we use a combination of multigenerational population genetic data, mating patterns from a natural population, behavioral assays, and mark-recapture data within clinal hybrid zones of the genus Xiphophorus to test the role of assortative mating in maintaining population structure and the potential for ongoing genetic exchange between heterospecifics. Our data demonstrate that population structure is temporally robust and driven largely by assortative mating stemming from precopulatory isolation between pure species. Furthermore, mark-recapture data revealed that rates of migration within the same stream reach are far below the level needed to support population structure. In contrast to many empirical studies of natural hybrid zones, there appeared to be no hybrid male dysfunction or discrimination against hybrid males by pure parental females, and hybrid females mated and associated with pure species and hybrid males at random. Despite strong isolation between pure parentals, hybrids therefore can act as a conduit for genetic exchange between heterospecifics, which has been shown to increase the tempo of evolutionary change. Additionally, our findings highlight the complexity of natural hybrid zone dynamics, demonstrating that sexual and ecological selection together can give rise to patterns that do not fit classical models of hybrid zone evolution.

  10. Microtubules: A network for solitary waves

    Directory of Open Access Journals (Sweden)

    Zdravković Slobodan

    2017-01-01

    Full Text Available In the present paper we deal with nonlinear dynamics of microtubules. The structure and role of microtubules in cells are explained as well as one of models explaining their dynamics. Solutions of the crucial nonlinear differential equation depend on used mathematical methods. Two commonly used procedures, continuum and semi-discrete approximations, are explained. These solutions are solitary waves usually called as kink solitons, breathers and bell-type solitons. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III45010

  11. Plant hybrid zones affect biodiversity: Tools for a genetic-based understanding of community structure

    Energy Technology Data Exchange (ETDEWEB)

    Whitham, T.G.; Martinsen, G.D.; Keim, P. [Northern Arizona Univ., Flagstaff, AZ (United States); Floate, K.D. [Agriculture and Agri-Food Canada, Lethbridge, Alberta (Canada); Dungey, H.S. [Univ. of Tasmania, Hobart, Tasmania (Australia)]|[Queensland Forest Research Inst., Gympie, Queensland (Australia); Potts, B.M. [Univ. of Tasmania, Hobart, Tasmania (Australia)

    1999-03-01

    Plant hybrid zones are dynamic centers of ecological and evolutionary processes for plants and their associated communities. Studies in the wild and in gardens with synthetic crosses showed that hybrid eucalypts supports the greatest species richness and abundances of insect and fungal taxa. In an updated review of 152 case studies of taxa associated with diverse hybridizing systems, there were 43 (28%) cases of hybrids being more susceptible than their parent species, 7 (5%) resistant, 35 (23%) additive, 35 (23%) dominant, and 32 (21%) showed no response to hybridization. Thus, most taxa respond to hybrids in ways that result in equal or greater abundance, and hybrids tend to accumulate the taxa of their parent species. These studies suggest that genetic-based plant traits affect the distribution of many species and that the variation in hybrids can be used as tools to examine the genetic components of community structure and biodiversity.

  12. Long range energy transfer in graphene hybrid structures

    Science.gov (United States)

    Gonçalves, Hugo; Bernardo, César; Moura, Cacilda; Ferreira, R. A. S.; André, P. S.; Stauber, Tobias; Belsley, Michael; Schellenberg, Peter

    2016-08-01

    In this work we quantify the distance dependence for the extraction of energy from excited chromophores by a single layer graphene flake over a large separation range. To this end hybrid structures were prepared, consisting of a thin (2 nm) layer of a polymer matrix doped with a well chosen strongly fluorescent organic molecule, followed by an un-doped spacer layer of well-defined thicknesses made of the same polymer material and an underlying single layer of pristine, undoped graphene. The coupling strength is assessed through the variation of the fluorescence decay kinetics as a function of distance between the graphene and the excited chromophore molecules. Non-radiative energy transfer to the graphene was observed at distances of up to 60 nm a range much greater than typical energy transfer distances observed in molecular systems.

  13. Structural Acoustic Response of Shape Memory Alloy Hybrid Composite Panels

    Science.gov (United States)

    Turner, Travis L.

    1996-01-01

    A method has been developed to predict the structural acoustic response of shape memory alloy hybrid composite panels subjected to acoustic excitation. The panel is modeled by a finite element analysis and the radiated field is predicted using Rayleigh's integral. Transmission loss predictions for the case of an aluminum panel excited by a harmonic acoustic pressure are shown to compare very well with a classical analysis. Predictions of the normal velocity response and transmitted acoustic pressure for a clamped aluminum panel show excellent agreement with experimental measurements. Predicted transmission loss performance for a composite panel with and without shape memory alloy reinforcement are also presented. The preliminary results demonstrate that the transmission loss can be significantly increased with shape memory alloy reinforcement.

  14. Hybrid nano-structure for enhanced energy storage devices

    Science.gov (United States)

    Shuvo, Mohammad Arif Ishtiaque

    The goal of this research is to develop electrode materials using various nano-structure hybrids for improved energy storage devices. Enhancing the performance of energy storage device has been gaining tremendous attention since it holds the key solution to advance renewable energy usage thus reduce the consumption of fossil fuels. The application of energy storage devices such as super-capacitor and Li-ion-battery has seen significant growth; however, it is still limited mainly by charge/discharge rate and energy density. One of the solutions is to use nano-structure materials, which offer higher power at high energy density and improved stability during the charge discharge cycling of ions in and out of the storage electrode material. In this research, carbon-based materials (e.g. porous carbon, graphene) in conjunction with metal oxides such as CeO2 nanoparticles/TiO2 nanowires are synthesized utilizing low temperature hydrothermal method for the fabrication of advanced electrode materials. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), X-ray Photoelectron Spectroscopy (XPS), and Fourier Transformation Infrared Spectroscopy (FTIR) were used for materials characterization. Poentio-galvanostat, battery analyzer, and Electrochemical Impedance Spectroscopy (EIS) were used for evaluating the electrochemical performance. The testing results have shown that a maximum 500% higher specific capacitance could be obtained using porous carbon/CeO2 instead of porous carbon for super-capacitor application and microwave exfoliated graphene oxide/TiO2 nanowire hybrid provides up to 80% increment of specific capacity compared to porous carbon anode for Li-ion-battery application.

  15. Time-Dependent Cylindrical and Spherical Solitary Structures and Double Layers of Dust Ion-Acoustic Waves in Ultra-Relativistic Dense Plasma

    Institute of Scientific and Technical Information of China (English)

    T.Akhter; M.M.Hossain; A.A.Mamun

    2013-01-01

    Cylindrical and spherical (nonplanar) solitary waves (SWs) and double layers (DLs) in a multi-ion plasma system (containing inertial positively as well as negatively charged ions,non-inertial degenerate electrons,and negatively charged static dust) are studied by employing the standard reductive perturbation method.The modified Gardner (MG) equation describing the nonlinear propagation of the dust ion-acoustic (DIA) waves is derived,and its nonplanar SWs and DLs solutions are numerically analyzed.The parametric regimes for the existence of SWs,which are associated with both positive and negative potential,and DLs which are associated with negative potential,are obtained.The basic features of nonplanar DIA SWs,and DLs,which are found to be different from planar ones,are also identified.

  16. Hybrid optical-fibre/geopolymer sensors for structural health monitoring of concrete structures

    Science.gov (United States)

    Perry, M.; Saafi, M.; Fusiek, G.; Niewczas, P.

    2015-04-01

    In this work, we demonstrate hybrid optical-fibre/geopolymer sensors for monitoring temperature, uniaxial strain and biaxial strain in concrete structures. The hybrid sensors detect these measurands via changes in geopolymer electrical impedance, and via optical wavelength measurements of embedded fibre Bragg gratings. Electrical and optical measurements were both facilitated by metal-coated optical fibres, which provided the hybrid sensors with a single, shared physical path for both voltage and wavelength signals. The embedded fibre sensors revealed that geopolymer specimens undergo 2.7 mɛ of shrinkage after one week of curing at 42 °C. After curing, an axial 2 mɛ compression of the uniaxial hybrid sensor led to impedance and wavelength shifts of 7 × 10-2 and -2 × 10-4 respectively. The typical strain resolution in the uniaxial sensor was 100 μ \\varepsilon . The biaxial sensor was applied to the side of a concrete cylinder, which was then placed under 0.6 mɛ of axial, compressive strain. Fractional shifts in impedance and wavelength, used to monitor axial and circumferential strain, were 3 × 10-2 and 4 × 10-5 respectively. The biaxial sensor’s strain resolution was approximately 10 μ \\varepsilon in both directions. Due to several design flaws, the uniaxial hybrid sensor was unable to accurately measure ambient temperature changes. The biaxial sensor, however, successfully monitored local temperature changes with 0.5 °C resolution.

  17. Spatio-temporal changes in the genetic structure of the Passerina bunting hybrid zone.

    Science.gov (United States)

    Carling, Matthew D; Zuckerberg, Benjamin

    2011-03-01

    Although theoretical models predict that the structure of a hybrid zone can change under a variety of scenarios, only a few empirical studies of hybrid zones have unequivocally demonstrated zone movement. These studies are rare because few data sets exist that include repeated, temporally spaced, samples of the same hybrid zone. We analysed mitochondrial DNA haplotype data from samples separated by 40-45 years from across the Passerina amoena (Lazuli Bunting) and Passerina cyanea (Indigo Bunting) hybrid zone to investigate whether the genetic structure of this zone has changed during that interval. Both cline and generalized linear mixed modelling analyses uncovered a significant narrowing and a substantial westward shift of the Passerina bunting hybrid zone, clearly illustrating hybrid zone movement. The cause of the change may be due to a combination of ecological, demographic and behavioural factors. Our results predict that the width of the hybrid zone will continue to narrow over time, a finding consistent with reinforcement theory.

  18. A novel organic-inorganic hybrid tandem solar cell with inverted structure

    Science.gov (United States)

    Bahrami, A.; Faez, R.

    2017-04-01

    A novel organic-inorganic hybrid tandem solar cell with inverted structure is proposed. This efficient double-junction hybrid tandem solar cell consists of a single-junction hydrogenated amorphous silicon (a-Si:H) subcell with n-i-p structure as front cell and a P3HT:PCBM organic subcell with inverted structure as back cell. In order to optimize the hybrid tandem cell, we have performed a simulation based on transfer matrix method. We have compared the characteristics of this novel structure with a conventional structure. As a result, a power conversion efficiency (PCE) of 6.1 and 24% improvement compared to the conventional hybrid tandem cell was achieved. We also discuss the high potential of this novel structure for realizing high-stability organic-inorganic hybrid photovoltaic devices.

  19. Optoelectronic Properties of Hybrid Titania Nanotubes/Hematite Nanoparticles Structures

    Science.gov (United States)

    Wang, Lili; Panaitescu, Eugen; Menon, Latika

    2015-03-01

    TiO2/Fe2O3 nanostructures are becoming promising alternatives for improving cost effectiveness (in /W) of emerging photovoltaic devices such as dye sensitized or metal-insulator-semiconductor solar cells, combining the low cost, earth abundance and stability of the materials with the enhanced performance offered by the nanoscale architecture. We investigated novel, high quality titania/hematite composites, namely hematite nanoparticle decorated titania nanotube arrays, which were obtained by a simple, inexpensive and easily scalable two-step process, electrochemical anodization of titanium followed by forced hydrolysis. The titania nanotubular scaffold provides a large active surface area, while the iron oxide nanoparticles significantly broaden the light absorption range into the visible region. The morphological and structural characteristics of the samples were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The light absorption efficiency was measured by diffuse reflectance spectroscopy (DRS), and the optoelectronic behavior of the hybrid structures was analyzed by IV measurements under simulated solar illumination. The influence of the synthesis process and the structure design on the photovoltaic performance is currently investigated for optimal device prototyping.

  20. Solitary Eccrine Syringofibroadenoma and Successful Treatment with Cryotherapy.

    Science.gov (United States)

    Ozkaya, Dilek Biyik; Su, Ozlem; Bahalı, Anıl Gülsel; Topukçu, Bugce; Dizman, Didem; Tosuner, Zeynep; Demirkesen, Cuyan; Onsun, Nahide

    2016-05-01

    First described in 1963, eccrine syringofibroadenoma (ESFA) is a rare benign tumor that proliferates with differentiation toward ductal eccrine structures. There are many clinical presentations, including plaques, papules, verrucous plaques, keratotic tumors, and solitary tumors. The age of onset varies, with presentation between 16 and 80 years; however, solitary lesions are seen most commonly in the seventh and eighth decades. Here, we present the case of a 72-year-old woman referred to our outpatient clinic with a nodule on her leg. The histopathology result was ESFA. The lesion regressed after six cryotherapy sessions. Physicians should consider the possibility of ESFA and must remember its malignant potential in elderly patients.

  1. Measurement of velocity field in parametrically excited solitary waves

    CERN Document Server

    Gordillo, Leonardo

    2014-01-01

    Paramerically excited solitary waves emerge as localized structures in high-aspect-ratio free surfaces subject to vertical vibrations. Herein, we provide the first experimental characterization of the hydrodynamics of thess waves using Particle Image Velocimetry. We show that the underlying velocity field of parametrically excited solitary waves is mainly composed by an oscillatory velocity field. Our results confirm the accuracy of Hamiltonian models with added dissipation in describing this field. Remarkably, our measurements also uncover the onset of a streaming velocity field which is shown to be as important as other crucial nonlinear terms in the current theory. The observed streaming pattern is particularly interesting due to the presence of oscillatory meniscii.

  2. Solitary mastocytoma in an adult

    Directory of Open Access Journals (Sweden)

    Jain V

    1997-01-01

    Full Text Available A 24-year old female developed late onset solitary mastocytoma on the left forearm. She complained of intense pruritus off and on which was not associated with flushing of face and blister formation over the nodule. Darier′s sign was positive. Excisional biopsy was done and histopathology confirmed the diagnosis.

  3. Bulk solitary waves in elastic solids

    Science.gov (United States)

    Samsonov, A. M.; Dreiden, G. V.; Semenova, I. V.; Shvartz, A. G.

    2015-10-01

    A short and object oriented conspectus of bulk solitary wave theory, numerical simulations and real experiments in condensed matter is given. Upon a brief description of the soliton history and development we focus on bulk solitary waves of strain, also known as waves of density and, sometimes, as elastic and/or acoustic solitons. We consider the problem of nonlinear bulk wave generation and detection in basic structural elements, rods, plates and shells, that are exhaustively studied and widely used in physics and engineering. However, it is mostly valid for linear elasticity, whereas dynamic nonlinear theory of these elements is still far from being completed. In order to show how the nonlinear waves can be used in various applications, we studied the solitary elastic wave propagation along lengthy wave guides, and remarkably small attenuation of elastic solitons was proven in physical experiments. Both theory and generation for strain soliton in a shell, however, remained unsolved problems until recently, and we consider in more details the nonlinear bulk wave propagation in a shell. We studied an axially symmetric deformation of an infinite nonlinearly elastic cylindrical shell without torsion. The problem for bulk longitudinal waves is shown to be reducible to the one equation, if a relation between transversal displacement and the longitudinal strain is found. It is found that both the 1+1D and even the 1+2D problems for long travelling waves in nonlinear solids can be reduced to the Weierstrass equation for elliptic functions, which provide the solitary wave solutions as appropriate limits. We show that the accuracy in the boundary conditions on free lateral surfaces is of crucial importance for solution, derive the only equation for longitudinal nonlinear strain wave and show, that the equation has, amongst others, a bidirectional solitary wave solution, which lead us to successful physical experiments. We observed first the compression solitary wave in the

  4. Blind Evaluation of Hybrid Protein Structure Analysis Methods based on Cross-Linking.

    Science.gov (United States)

    Belsom, Adam; Schneider, Michael; Brock, Oliver; Rappsilber, Juri

    2016-07-01

    Hybrid methods combine experimental data and computational modeling to analyze protein structures that are elusive to structure determination. To spur the development of hybrid methods, we propose to test them in the context of the CASP experiment and would like to invite experimental groups to participate in this initiative.

  5. Super-hybrid composites - An emerging structural material

    Science.gov (United States)

    Chamis, C. C.; Lark, R. F.; Sullivan, T. L.

    1975-01-01

    Specimens of super-hybrids and advanced fiber composites were subjected to extensive tests to determine their mechanical properties, including impact and thermal fatigue. The super-hybrids were fabricated by a procedure similar to that reported by Chamis et al., (1975). Super-hybrids subjected to 1000 cycles of thermal fatigue from -100 to 300 F retained over 90% of their longitudinal flexural strength and over 75% of their transverse flexural strength; their transverse flexural strength may be as high as 8 times that of a commercially supplied boron/1100-Al composite. The thin specimen Izod longitudinal impact resistance of the super-hybrids was twice that of the boron/110-Al material. Super-hybrids subjected to transverse tensile loads exhibited nonlinear stress-strain relationships. The experimentally determined initial membrane (in-plane) and bending elastic properties of super-hybrids were predicted adequately by linear laminate analysis.

  6. Generation of internal solitary waves by frontally forced intrusions in geophysical flows.

    Science.gov (United States)

    Bourgault, Daniel; Galbraith, Peter S; Chavanne, Cédric

    2016-12-06

    Internal solitary waves are hump-shaped, large-amplitude waves that are physically analogous to surface waves except that they propagate within the fluid, along density steps that typically characterize the layered vertical structure of lakes, oceans and the atmosphere. As do surface waves, internal solitary waves may overturn and break, and the process is thought to provide a globally significant source of turbulent mixing and energy dissipation. Although commonly observed in geophysical fluids, the origins of internal solitary waves remain unclear. Here we report a rarely observed natural case of the birth of internal solitary waves from a frontally forced interfacial gravity current intruding into a two-layer and vertically sheared background environment. The results of the analysis carried out suggest that fronts may represent additional and unexpected sources of internal solitary waves in regions of lakes, oceans and atmospheres that are dynamically similar to the situation examined here in the Saguenay Fjord, Canada.

  7. Generation of internal solitary waves by frontally forced intrusions in geophysical flows

    Science.gov (United States)

    Bourgault, Daniel; Galbraith, Peter S.; Chavanne, Cédric

    2016-12-01

    Internal solitary waves are hump-shaped, large-amplitude waves that are physically analogous to surface waves except that they propagate within the fluid, along density steps that typically characterize the layered vertical structure of lakes, oceans and the atmosphere. As do surface waves, internal solitary waves may overturn and break, and the process is thought to provide a globally significant source of turbulent mixing and energy dissipation. Although commonly observed in geophysical fluids, the origins of internal solitary waves remain unclear. Here we report a rarely observed natural case of the birth of internal solitary waves from a frontally forced interfacial gravity current intruding into a two-layer and vertically sheared background environment. The results of the analysis carried out suggest that fronts may represent additional and unexpected sources of internal solitary waves in regions of lakes, oceans and atmospheres that are dynamically similar to the situation examined here in the Saguenay Fjord, Canada.

  8. Analysis of SMA Hybrid Composite Structures using Commercial Codes

    Science.gov (United States)

    Turner, Travis L.; Patel, Hemant D.

    2004-01-01

    A thermomechanical model for shape memory alloy (SMA) actuators and SMA hybrid composite (SMAHC) structures has been recently implemented in the commercial finite element codes MSC.Nastran and ABAQUS. The model may be easily implemented in any code that has the capability for analysis of laminated composite structures with temperature dependent material properties. The model is also relatively easy to use and requires input of only fundamental engineering properties. A brief description of the model is presented, followed by discussion of implementation and usage in the commercial codes. Results are presented from static and dynamic analysis of SMAHC beams of two types; a beam clamped at each end and a cantilevered beam. Nonlinear static (post-buckling) and random response analyses are demonstrated for the first specimen. Static deflection (shape) control is demonstrated for the cantilevered beam. Approaches for modeling SMAHC material systems with embedded SMA in ribbon and small round wire product forms are demonstrated and compared. The results from the commercial codes are compared to those from a research code as validation of the commercial implementations; excellent correlation is achieved in all cases.

  9. Optical properties of hybrid semiconductor-metal structures

    Energy Technology Data Exchange (ETDEWEB)

    Kreilkamp, L.E.; Pohl, M.; Akimov, I.A.; Yakovlev, D.R.; Bayer, M. [Experimentelle Physik 2, Technische Universitaet Dortmund, 44221 Dortmund (Germany); Belotelov, V.I.; Zvezdin, A.K. [A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, 119992 Moscow (Russian Federation); Karczewski, G.; Wojtowicz, T. [Institute of Physics, Polish Academy of Sciences, 02668 Warsaw (Poland); Rudzinski, A.; Kahl, M. [Raith GmbH, Konrad-Adenauer-Allee 8, 44263 Dortmund (Germany)

    2012-07-01

    We study the optical properties of hybrid nanostructures comprising a semiconductor CdTe quantum well (QW) separated by a thin CdMgTe cap layer of 40 nm from a patterned gold film. The CdTe/CdMgTe QW structure with a well width of 10nm was grown by molecular beam epitaxy. The one-dimensional periodic gold films on top were made using e-beam lithography and lift-off process. The investigated structures can be considered as plasmonic crystals because the metal films attached to the semiconductor are patterned with a period in the range from 475 to 600 nm, which is comparable to the surface plasmon-polariton (SPP) wavelength. Angle dependent reflection spectra at room temperature clearly show plasmonic resonances. PL spectra taken at low temperatures of about 10 K under below- and above-barrier illumination show significant modifications compared to the unstructured QW sample. The number of emission lines and their position shift change depending on the excitation energy. The role of exciton-SPP coupling and Schottky barrier at the semiconductor-metal interface are discussed.

  10. Hybrid surface structures for efficiency enhancement of fluorescent SiC for white LED application

    DEFF Research Database (Denmark)

    Ou, Yiyu; Xiong, Meng; Lu, Weifang

    Hybrid structures contain structures in both micro- and nano-meter scale have been fabricated on fluorescent SiC by applying a fast fabrication method. Luminescence efficiency of f-SiC was enhanced significantly compared with normal nanostructures....

  11. The Tower: Modelling, Analysis and Construction of Bending Active Tensile Membrane Hybrid Structures

    DEFF Research Database (Denmark)

    Holden Deleuran, Anders; Schmeck, Michel; Charles Quinn, Gregory

    2015-01-01

    as combining two or more structural concepts and materials together to create a stronger whole. The paper presents the methods used and developed for design, simulation, evaluation and production, as well as the challenges and obstacles to overcome to build a complex hybrid tower structure in an outside......The project is the result of an interdisciplinary research collaboration between CITA, KET and Fibrenamics exploring the design of integrated hybrid structures employing bending active elements and tensile membranes with bespoke material properties and detailing. Hybrid structures are defined here...

  12. Periodic Semifolded Solitary Waves for (2+1)-Dimensional Variable Coefficient Broer-Kaup System

    Institute of Scientific and Technical Information of China (English)

    JI Jie; HUANG Wen-Hua

    2008-01-01

    Applying the extended mapping method via Riccati equation, many exact variable separation solutions for the (2+1)-dimensional variable coefficient Broer-Kaup equation are obtained. Introducing multiple valued function and Jacobi elliptic function in the seed solution, special types of periodic semifolded solitary waves are derived. In the long wave limit these periodic semifolded solitary wave excitations may degenerate into single semifolded localized soliton structures. The interactions of the periodic semifolded solitary waves and their degenerated single semifolded soliton structures are investigated graphically and found to be completely elastic.

  13. An ancillary CT finding of intrapulmonary solitary fibrous tumor: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Jun; Rho, Ji Young; Kwon, Ah Young [CHA Bundang Medical Center, CHA University, Seongnam (Korea, Republic of)

    2017-02-15

    Intrapulmonary solitary fibrous tumor is extremely rare. A few reports have presented typical CT findings such as well-defined, variable—sized, heterogeneously or homogenously well-enhanced intrapulmonary nodules. We report herein a rare case of intrapulmonary solitary fibrous tumor that showed typical clinical and CT features, and we also provide an ancillary CT finding that shows a distinguishable tubular vascular structure within the nodule. The tubular vascular structure was conjoined to the proximal pulmonary vein. In this study, we highlight an ancillary CT finding reported for the first time for the diagnosis of a patient with intrapulmonary solitary fibrous tumor.

  14. A new hybrid coding for protein secondary structure prediction based on primary structure similarity.

    Science.gov (United States)

    Li, Zhong; Wang, Jing; Zhang, Shunpu; Zhang, Qifeng; Wu, Wuming

    2017-03-16

    The coding pattern of protein can greatly affect the prediction accuracy of protein secondary structure. In this paper, a novel hybrid coding method based on the physicochemical properties of amino acids and tendency factors is proposed for the prediction of protein secondary structure. The principal component analysis (PCA) is first applied to the physicochemical properties of amino acids to construct a 3-bit-code, and then the 3 tendency factors of amino acids are calculated to generate another 3-bit-code. Two 3-bit-codes are fused to form a novel hybrid 6-bit-code. Furthermore, we make a geometry-based similarity comparison of the protein primary structure between the reference set and the test set before the secondary structure prediction. We finally use the support vector machine (SVM) to predict those amino acids which are not detected by the primary structure similarity comparison. Experimental results show that our method achieves a satisfactory improvement in accuracy in the prediction of protein secondary structure.

  15. Hybrid Composites for LH2 Fuel Tank Structure

    Science.gov (United States)

    Grimsley, Brian W.; Cano, Roberto J.; Johnston, Norman J.; Loos, Alfred C.; McMahon, William M.

    2001-01-01

    The application of lightweight carbon fiber reinforced plastics (CFRP) as structure for cryogenic fuel tanks is critical to the success of the next generation of Reusable Launch Vehicles (RLV). The recent failure of the X-33 composite fuel tank occurred in part due to microcracking of the polymer matrix, which allowed cryogen to permeate through the inner skin to the honeycomb core. As part of an approach to solve these problems, NASA Langley Research Center (LaRC) and Marshall Space Flight Center (MSFC) are working to develop and investigate polymer films that will act as a barrier to the permeation of LH2 through the composite laminate. In this study two commercially available films and eleven novel LaRC films were tested in an existing cryogenics laboratory at MSFC to determine the permeance of argon at room temperature. Several of these films were introduced as a layer in the composite to form an interleaved, or hybrid, composite to determine the effects on permeability. In addition, the effects of the interleaved layer thickness, number, and location on the mechanical properties of the composite laminate were investigated. In this initial screening process, several of the films were found to exhibit lower permeability to argon than the composite panels tested.

  16. A Hybrid Structure for Data Aggregation in Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Hedieh Sajedi

    2014-01-01

    Full Text Available In recent years, wireless sensor networks have been used for various applications such as environmental monitoring, military and medical applications. A wireless sensor network uses a large number of sensor nodes that continuously collect and send data from a specific region to a base station. Data from sensors are collected from the study area in the common scenario of sensor networks. Afterward, sensed data is sent to the base station. However, neighboring sensors often lead to redundancy of data. Transmission of redundant data to the base station consumes energy and produces traffic, because process is run in a large network. Data aggregation was proposed in order to reduce redundancy in data transformation and traffic. The most popular communication protocol in this field is cluster based data aggregation. Clustering causes energy balance, but sometimes energy consumption is not efficient due to the long distance between cluster heads and base station. In another communication protocol, which is based on a tree construction, because of the short distance between the sensors, energy consumption is low. In this data aggregation approach, since each sensor node is considered as one of the vertices of a tree, the depth of tree is usually high. In this paper, an efficient hierarchical hybrid approach for data aggregation is presented. It reduces energy consumption based on clustering and minimum spanning tree. The benefit of combining clustering and tree structure is reducing the disadvantages of previous structures. The proposed method firstly employs clustering algorithm and then a minimum spanning tree is constructed based on cluster heads. Our proposed method was compared to LEACH which is a well-known data aggregation method in terms of energy consumption and the amount of energy remaining in each sensor network lifetime. Simulation results indicate that our proposed method is more efficient than LEACH algorithm considering energy

  17. Solitary angiokeratoma of the tongue.

    Science.gov (United States)

    Sion-Vardy, Netta; Manor, Esther; Puterman, Max; Bodner, Lipa

    2008-01-01

    Angiokeratoma is a rare cutaneous lesion. It can be either a generalized systemic form, presenting as multiple asymptomatic papules on the skin, associated with metabolic diseases or a solitary cutaneous form. Oral cavity involvement is more common in the systemic form, as a part of a more generalized cutaneous disease, but very rare in the localized form of angiokeratoma. A 45-year-old female presented with a painless lesion on the tongue of one months duration, which bled occasionally. On clinical examination, a lesion of approximately 5 mm in diameter was observed on the left surface of the tongue. The lesion was purple in color with a granulomatous appearance. There were no other changes in the oral mucosa. On dermatologic examination, no angiokeratomas were found, anywhere on the skin. The lesion was excised under local anesthesia. The histologic diagnosis was angiokeratoma. A case of a solitary angiokeratoma of the tongue is reported. We report here the third intra-oral case and the second case in the tongue with solitary angiokeratoma.

  18. Structural investigation of the zirconium-titanium based amino trimethylene phosphonate hybrid coating on aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    Shuanghong WANG; Changsheng LIU; Fengjun SHAN

    2009-01-01

    A zirconium-titanium based amino trimethylene phosphonate hybrid coating on AA6061 aluminum alloys was formed by dipping in a fluorotitanate/zirconate acid and amino trimethylene phosphonic acid (ATMP) solution for improving the lacquer adhesion and corrosion resistance as a substitute of chromate coatings. The morphol-ogy and structure of the hybrid coating were studied by means of scanning electror microscopy (SEM) and atomic force microscopy (AFM). The surface compositior and structure characteristics were also investigated by means of X-ray photoelectron spectroscopy (XPS) and Fourier transformation infra-red spectroscopy (FTIR). The results of SEM and AFM show that the hybrid coating present piece particle distrib-ution which is much denser than that of the zirconium-titanium coating. The results of XPS and FTIR indicate that the hybrid coating is a hybrid composite structure composed of both the zirconium-titanium and amino trimethylene phosphonate coat-ings.

  19. Temperature Histories of Structural Steel Laser and Hybrid Laser-GMA Welds Calculated Using Multiple Constraints

    Science.gov (United States)

    2015-12-10

    Naval Research Laboratory Washington, DC 20375-5320 NRL/MR/6390--15-9665 Temperature Histories of Structural Steel Laser and Hybrid Laser-GMA Welds...NUMBER OF PAGES 17. LIMITATION OF ABSTRACT Temperature Histories of Structural Steel Laser and Hybrid Laser-GMA Welds Calculated Using Multiple...202) 767-2601 Inverse thermal analyses of structural steel deep-penetration welds are presented. These analyses employ a methodology that is in terms of

  20. Solitary vortex couples in viscoelastic Couette flow

    CERN Document Server

    Groisman, A; Groisman, Alexander; Steinberg, Victor

    1996-01-01

    We report experimental observation of a localized structure, which is of a new type for dissipative systems. It appears as a solitary vortex couple ("diwhirl") in Couette flow with highly elastic polymer solutions. A unique property of the diwhirls is that they are stationary, in contrast to the usual localized wave structures in both Hamiltonian and dissipative systems which are stabilized by wave dispersion. It is also a new object in fluid dynamics - a couple of vortices that build a single entity somewhat similar to a magnetic dipole. The diwhirls arise as a result of a purely elastic instability through a hysteretic transition at negligible Reynolds numbers. It is suggested that the vortex flow is driven by the same forces that cause the Weissenberg effect. The diwhirls have a striking asymmetry between the inflow and outflow, which is also an essential feature of the suggested elastic instability mechanism.

  1. Effect of secondary structure on the thermodynamics and kinetics of PNA hybridization to DNA hairpins

    DEFF Research Database (Denmark)

    Kushon, S A; Jordan, J P; Seifert, J L

    2001-01-01

    structures in both target and probe molecules are shown to depress the melting temperatures and free energies of the probe-target duplexes. Kinetic analysis of hybridization yields reaction rates that are up to 160-fold slower than hybridization between two unstructured strands. The thermodynamic and kinetic...

  2. A Best Practice Modular Design of a Hybrid Course Delivery Structure for an Executive Education Program

    Science.gov (United States)

    Klotz, Dorothy E.; Wright, Thomas A.

    2017-01-01

    This article highlights a best practice approach that showcases the highly successful deployment of a hybrid course delivery structure for an Operations core course in an Executive MBA Program. A key design element of the approach was the modular design of both the course itself and the learning materials. While other hybrid deployments may stress…

  3. A Best Practice Modular Design of a Hybrid Course Delivery Structure for an Executive Education Program

    Science.gov (United States)

    Klotz, Dorothy E.; Wright, Thomas A.

    2017-01-01

    This article highlights a best practice approach that showcases the highly successful deployment of a hybrid course delivery structure for an Operations core course in an Executive MBA Program. A key design element of the approach was the modular design of both the course itself and the learning materials. While other hybrid deployments may stress…

  4. A Structural Model Decomposition Framework for Hybrid Systems Diagnosis

    Science.gov (United States)

    Daigle, Matthew; Bregon, Anibal; Roychoudhury, Indranil

    2015-01-01

    Nowadays, a large number of practical systems in aerospace and industrial environments are best represented as hybrid systems that consist of discrete modes of behavior, each defined by a set of continuous dynamics. These hybrid dynamics make the on-line fault diagnosis task very challenging. In this work, we present a new modeling and diagnosis framework for hybrid systems. Models are composed from sets of user-defined components using a compositional modeling approach. Submodels for residual generation are then generated for a given mode, and reconfigured efficiently when the mode changes. Efficient reconfiguration is established by exploiting causality information within the hybrid system models. The submodels can then be used for fault diagnosis based on residual generation and analysis. We demonstrate the efficient causality reassignment, submodel reconfiguration, and residual generation for fault diagnosis using an electrical circuit case study.

  5. Multi-component optical solitary waves

    DEFF Research Database (Denmark)

    Kivshar, Y. S.; Sukhorukov, A. A.; Ostrovskaya, E. A.

    2000-01-01

    We discuss several novel types of multi-component (temporal and spatial) envelope solitary waves that appear in fiber and waveguide nonlinear optics. In particular, we describe multi-channel solitary waves in bit-parallel-wavelength fiber transmission systems for highperformance computer networks......, multi-color parametric spatial solitary waves due to cascaded nonlinearities of quadratic materials, and quasiperiodic envelope solitons due to quasi-phase-matching in Fibonacci optical superlattices. (C) 2000 Elsevier Science B.V. All rights reserved....

  6. Hybrid Structures for Surface-Enhanced Raman Scattering: DNA Origami/Gold Nanoparticle Dimer/Graphene.

    Science.gov (United States)

    Prinz, Julia; Matković, Aleksandar; Pešić, Jelena; Gajić, Radoš; Bald, Ilko

    2016-10-01

    A combination of three innovative materials within one hybrid structure to explore the synergistic interaction of their individual properties is presented. The unique electronic, mechanical, and thermal properties of graphene are combined with the plasmonic properties of gold nanoparticle (AuNP) dimers, which are assembled using DNA origami nanostructures. This novel hybrid structure is characterized by means of correlated atomic force microscopy and surface-enhanced Raman scattering (SERS). It is demonstrated that strong interactions between graphene and AuNPs result in superior SERS performance of the hybrid structure compared to their individual components. This is particularly evident in efficient fluorescence quenching, reduced background, and a decrease of the photobleaching rate up to one order of magnitude. The versatility of DNA origami structures to serve as interface for complex and precise arrangements of nanoparticles and other functional entities provides the basis to further exploit the potential of the here presented DNA origami-AuNP dimer-graphene hybrid structures.

  7. A gold hybrid structure as optical coupler for quantum well infrared photodetector

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Jiayi; Li, Qian; Jing, Youliang [National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu Tian Road, Shanghai 200083 (China); Chen, Xiaoshuang, E-mail: xschen@mail.sitp.ac.cn; Li, Zhifeng; Li, Ning; Lu, Wei [National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu Tian Road, Shanghai 200083 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2014-08-28

    A hybrid structure consisting of a square lattice of gold disk arrays and an overlaying gold film is proposed as an optical coupler for a backside-illuminated quantum well infrared photodetector (QWIP). Finite difference time-domain method is used to numerically simulate the reflection spectra and the field distributions of the hybrid structure combined with the QWIP device. The results show that the electric field component perpendicular to the quantum well is strongly enhanced when the plasmonic resonant wavelength of the hybrid structure coincides with the response one of the quantum well infrared photodetector regardless of the polarization of the incident light. The effect of the diameter and thickness of an individual gold disk on the resonant wavelength is also investigated, which indicates that the localized surface plasmon also plays a role in the light coupling with the hybrid structure. The coupling efficiency can exceed 50 if the structural parameters of the gold disk arrays are well optimized.

  8. ON THE STABILIZATION OF THE LINEAR HYBRID SYSTEM STRUCTURE

    Directory of Open Access Journals (Sweden)

    Kirillov

    2014-11-01

    Full Text Available The linear control hybrid system, consisting of a fi- nite set of subsystems (modes having different dimensions, is considered. The moments of reset time are determined by some complementary function – evolutionary time. This function satisfies the special complementary ordinary differential equation. The mode stabilization problem is solved for some class of piecewise linear controls. The method of stabilization relies on the set of invariant planes, the existence of which is due to the special form of the hybrid system.

  9. Extraordinary Magnetoresistance Effect in Semiconductor/Metal Hybrid Structure

    KAUST Repository

    Sun, Jian

    2013-06-27

    In this dissertation, the extraordinary magnetoresistance (EMR) effect in semiconductor/metal hybrid structures is studied to improve the performance in sensing applications. Using two-dimensional finite element simulations, the geometric dependence of the output sensitivity, which is a more relevant parameter for EMR sensors than the magnetoresistance (MR), is studied. The results show that the optimal geometry in this case is different from the geometry reported before, where the MR ratio was optimized. A device consisting of a semiconductor bar with length/width ratio of 5~10 and having only 2 contacts is found to exhibit the highest sensitivity. A newly developed three-dimensional finite element model is employed to investigate parameters that have been neglected with the two dimensional simulations utilized so far, i.e., thickness of metal shunt and arbitrary semiconductor/metal interface. The simulations show the influence of those parameters on the sensitivity is up to 10 %. The model also enables exploring the EMR effect in planar magnetic fields. In case of a bar device, the sensitivity to planar fields is about 15 % to 20 % of the one to perpendicular fields. 5 A “top-contacted” structure is proposed to reduce the complexity of fabrication, where neither patterning of the semiconductor nor precise alignment is required. A comparison of the new structure with a conventionally fabricated device shows that a similar magnetic field resolution of 24 nT/√Hz is obtained. A new 3-contact device is developed improving the poor low-field sensitivity observed in conventional EMR devices, resulting from its parabolic magnetoresistance response. The 3-contact device provides a considerable boost of the low field response by combining the Hall effect with the EMR effect, resulting in an increase of the output sensitivity by 5 times at 0.01 T compared to a 2-contact device. The results of this dissertation provide new insights into the optimization of EMR devices

  10. On the structural and physicochemical properties of gamma irradiated UHMWPE/silane hybrid

    Energy Technology Data Exchange (ETDEWEB)

    Shafiq, Muhammad [Advanced Polymer Laboratory, Department of Metallurgy and Materials Engineering, Pakistan Institute of Engineering and Applied Sciences, 45650 Islamabad (Pakistan); Mehmood, Malik Sajjad [Advanced Polymer Laboratory, Department of Metallurgy and Materials Engineering, Pakistan Institute of Engineering and Applied Sciences, 45650 Islamabad (Pakistan); Department of Basic Sciences and Humanities, University of Engineering and Technology, 47050 Taxila (Pakistan); Yasin, Tariq, E-mail: yasintariq@yahoo.com [Advanced Polymer Laboratory, Department of Metallurgy and Materials Engineering, Pakistan Institute of Engineering and Applied Sciences, 45650 Islamabad (Pakistan)

    2013-12-16

    This study has been carried to investigate the influence of gamma rays on the structural and physicochemical properties of UHMWPE/silane hybrid. UHMWPE was mixed with vinyltriethoxysilane (VTES) and compression molded sheets were irradiated at different doses of gamma rays. Fourier transform infrared spectroscopy indicated the formation of siloxane linkages in hybrids, which were found to be shifted towards lower wave number upon irradiation. The X-ray diffraction patterns showed significant increase in the percentage crystallinity of hybrid upon gamma irradiation, especially at 65 kGy absorbed dose. Scanning electron micrographs showed good consolidation and compaction with no surface defects. Moreover, the rough topography was changed to smooth ripple-like appearance upon γ-irradiation. Thermal analysis revealed that irradiated hybrids exhibited higher onset thermal degradation temperature, peak melting temperature, and crystalline lamellae thickness compared with the water treated hybrid. In addition, the tensile testing confirmed an increase of 41% and 133% in yield strength and Young's modulus in 100 kGy irradiated hybrid respectively than that of water treated hybrid. We hope that the irradiated UHMWPE/silane hybrids can be used in various high-strength applications such as total joint replacements, pickers for textile machinery, lining for coal chutes and dump trucks. - Highlights: • UHMWPE/silane hybrids have been prepared and irradiated using gamma rays. • The structural analysis revealed the formation siloxane linkages in the hybrid. • The crystallinity, thermal stability and mechanical properties of hybrids were improved with irradiation. • The irradiated hybrids can be used in various high-strength applications.

  11. Advanced Ceramic Matrix Composites with Multifunctional and Hybrid Structures

    Science.gov (United States)

    Singh, Mrityunjay; Morscher, Gregory N.

    2004-01-01

    Ceramic matrix composites are leading candidate materials for a number of applications in aeronautics, space, energy, and nuclear industries. Potential composite applications differ in their requirements for thickness. For example, many space applications such as "nozzle ramps" or "heat exchangers" require very thin (structures whereas turbine blades would require very thick parts (> or = 1 cm). Little is known about the effect of thickness on stress-strain behavior or the elevated temperature tensile properties controlled by oxidation diffusion. In this study, composites consisting of woven Hi-Nicalon (trademark) fibers a carbon interphase and CVI SiC matrix were fabricated with different numbers of plies and thicknesses. The effect of thickness on matrix crack formation, matrix crack growth and diffusion kinetics will be discussed. In another approach, hybrid fiber-lay up concepts have been utilized to "alloy" desirable properties of different fiber types for mechanical properties, thermal stress management, and oxidation resistance. Such an approach has potential for the C(sub I)-SiC and SiC(sub f)-SiC composite systems. CVI SiC matrix composites with different stacking sequences of woven C fiber (T300) layers and woven SiC fiber (Hi-Nicalon (trademark)) layers were fabricated. The results will be compared to standard C fiber reinforced CVI SiC matrix and Hi-Nicalon reinforced CVI SiC matrix composites. In addition, shear properties of these composites at different temperatures will also be presented. Other design and implementation issues will be discussed along with advantages and benefits of using these materials for various components in high temperature applications.

  12. Optical Fiber/Nanowire Hybrid Structures for Efficient Three-Dimensional Dye-Sensitized Solar Cells

    KAUST Repository

    Weintraub, Benjamin

    2009-11-09

    Wired up: The energy conversion efficiency of three-dimensional dye-sensitized solar cells (DSSCs) in a hybrid structure that integrates optical fibers and nanowire arrays is greater than that of a two-dimensional device. Internal axial illumination enhances the energy conversion efficiency of a rectangular fiber-based hybrid structure (see picture) by a factor of up to six compared to light illumination normal to the fiber axis from outside the device.

  13. A novel Michelson Fabry-Perot hybrid interference sensor based on the micro-structured fiber

    Science.gov (United States)

    Zhang, Yaxun; Zhang, Yu; Wang, Zhenzhen; Liu, Zhihai; Wei, Yong; Zhao, Enming; Yang, Xinghua; Zhang, Jianzhong; Yang, Jun; Yuan, Libo

    2016-09-01

    We propose and demonstrate a novel Michelson Fabry-Perot hybrid fiber interference sensor. By integrating a Michelson interferometer in a two-core fiber and a Fabry-Perot interferometer in a micro silica-capillary, we produce the Michelson Fabry-Perot hybrid interference sensor. Owing to the structure characteristic of the micro-structured fiber, this hybrid fiber interference sensor can achieve the measurement of the axial strain and radial bending simultaneously. The measurement sensitivity of the axial train is 0.015 nm/με and the measurement sensitivity of the radial bending is 1.393 nm/m-1.

  14. Geographic variation in the structure of oak hybrid zones provides insights into the dynamics of speciation.

    Science.gov (United States)

    Zeng, Yan-Fei; Liao, Wan-Jin; Petit, Rémy J; Zhang, Da-Yong

    2011-12-01

    Studying geographic variation in the rate of hybridization between closely related species could provide a useful window on the evolution of reproductive isolation. Reinforcement theory predicts greater prezygotic isolation in areas of prolonged contact between recently diverged species than in areas of recent contact, which implies that old contact zones would be dominated by parental phenotypes with few hybrids (bimodal hybrid zones), whereas recent contact zones would be characterized by hybrid swarms (unimodal hybrid zones). Here, we investigate how the hybrid zones of two closely related Chinese oaks, Quercus mongolica and Q. liaotungensis, are structured geographically using both nuclear and chloroplast markers. We found that populations of Q. liaotungensis located around the Changbai Mountains in Northeast China, an inferred glacial refugium, were introgressed by genes from Q. mongolica, suggesting historical contact between the two species in this region. However, these introgressed populations form sharp bimodal hybrid zones with Q. mongolica. In contrast, populations of Q. liaotungensis located in North China, which show no sign of ancient introgression with Q. mongolica, form unimodal hybrid zones with Q. mongolica. These results are consistent with the hypothesis that selection against hybrids has had sufficient time to reinforce the reproductive barriers between Q. liaotungensis and Q. mongolica in Northeast China but not in North China.

  15. Non-binary Hybrid LDPC Codes: Structure, Decoding and Optimization

    CERN Document Server

    Sassatelli, Lucile

    2007-01-01

    In this paper, we propose to study and optimize a very general class of LDPC codes whose variable nodes belong to finite sets with different orders. We named this class of codes Hybrid LDPC codes. Although efficient optimization techniques exist for binary LDPC codes and more recently for non-binary LDPC codes, they both exhibit drawbacks due to different reasons. Our goal is to capitalize on the advantages of both families by building codes with binary (or small finite set order) and non-binary parts in their factor graph representation. The class of Hybrid LDPC codes is obviously larger than existing types of codes, which gives more degrees of freedom to find good codes where the existing codes show their limits. We give two examples where hybrid LDPC codes show their interest.

  16. Hybrid structure of biotemplate-zinc-tin oxide for better optical, morphological and photocatalytic properties

    Science.gov (United States)

    Karpuraranjith, M.; Thambidurai, S.

    2017-03-01

    A new chitosan (as biotemplate)-zinc-tin oxide hybrid structure was successfully synthesized by a chemical precipitation method and annealed at 500 °C. We studied the structural changes, optical, thermal and photo catalytic properties. The chemical bonding of the Zn-O and Sn-O-Sn functional groups were confirmed by FT-IR absorption peaks appearing at 538 and 635 cm‑1. The different ratio of ZnO to SnO2 particles on the biotemplate matrix altered the morphology of the hybrids from an agglomerated state to a microcrystalline form confirmed by HR-SEM and TEM analysis. The formation of a Zn0.15Sn0.85O hybrid structure was observed in the visible light region, with an energy band gap of ∼3.19 eV and higher surface area of 98 m2 g‑1. The thermal property shows that CS-Zn0.15Sn0.85O has a higher thermal stability than a CS-Zn0.25Sn0.75O hybrid structure. The results demonstrate that the biotemplate-zinc-tin oxide hybrid structure has a reinforced effect compared to the other components. Therefore, a biotemplate-based zinc-tin oxide hybrid structure could be a promising material for better dye removal efficiency, which was obtained for ∼100 and 96% with MB and RY-15 dyes.

  17. [Solitary plasmocytoma of the mandible].

    Science.gov (United States)

    Laurent, F; Chausse, J M; Toccanier, M F; Kuffer, R

    1985-01-01

    The authors present a case of solitary bony plasmocytoma of the mandibule, with local amyloid deposition. Diagnosis was made at extemporaneous pathological examination, then confirmed by the examination of the fixed surgical sample. Immunoenzymologically the proliferation proved to be monoclonal, with secretion of kappa light chain. The patient was treated by surgical curettage and homologous cancelous bone filling, followed by 5,500 rads of electrontherapy. He was then regularly controlled during 8 years and remained free from local recurrence. All investigations in search of dissemination (Kahler disease) remained negative.

  18. Solitary Fibrous Tumor of the Stomach

    Science.gov (United States)

    Hussain, Qulsoom; Shafique, Khurram; Hurairah, Abu; Grossman, Evan B.

    2017-01-01

    Solitary fibrous tumor is a rare mesenchymal neoplasm that usually originates from the pleura, but has been reported in other extrapleural locations. We report a rare case of a solitary fibrous tumor of the stomach, which was successfully treated with endoscopic mucosal resection. PMID:28286800

  19. Solitary intraosseous neurofibroma of the tibia

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Guo-Shu; Chang, Wei-Chou; Juan, Chun-Jung; Chen, Cheng-Yu. [National Defense Medical Center, Department of Radiology, Tri-Service General Hospital, Neihu 114, Taipei (Taiwan); Lee, Chian-Her [National Defense Medical Center, Department of Orthopedic Surgery, Tri-Service General Hospital, Neihu 114, Taipei (Taiwan); Lee, Herng-Sheng [National Defense Medical Center, Department of Pathology, Tri-Service General Hospital, Neihu 114, Taipei (Taiwan)

    2005-05-01

    A solitary intraosseous neurofibroma is rare and mostly occurs in the mandible. We report a case of a solitary intraosseous neurofibroma of the tibia. The radiographic findings were nonspecific and showed an eccentrically located, osteolytic lesion with a thin sclerotic border in the diaphysis of the left proximal tibia. The entity of intraosseous neurofibroma is briefly reviewed. (orig.)

  20. Solitary Waves in Relativistic Electromagnetic Plasma

    Institute of Scientific and Technical Information of China (English)

    XIE Bai-Song; HUA Cun-Cai

    2005-01-01

    Solitary waves in relativistic electromagnetic plasmas are obtained numerically. The longitudinal momentum of electrons has been taken into account in the problem. It is found that in the moving frame with electromagnetic field propagating the solitary waves can exist in both cases, where the vector potential frequency is larger or smaller than the plasma characteristic frequency.

  1. Tensile properties of a boron/nitrogen-doped carbon nanotube–graphene hybrid structure

    Directory of Open Access Journals (Sweden)

    Kang Xia

    2014-03-01

    Full Text Available Doping is an effective approach that allows for the intrinsic modification of the electrical and chemical properties of nanomaterials. Recently, a graphene and carbon nanotube hybrid structure (GNHS has been reported, which extends the excellent properties of carbon-based materials to three dimensions. In this paper, we carried out a first-time investigation on the tensile properties of the hybrid structures with different dopants. It is found that with the presence of dopants, the hybrid structures usually exhibit lower yield strength, Young’s modulus, and earlier yielding compared to that of a pristine hybrid structure. For dopant concentrations below 2.5% no significant reduction of Young’s modulus or yield strength could be observed. For all considered samples, the failure is found to initiate at the region where the nanotubes and graphene sheets are connected. After failure, monatomic chains are normally observed around the failure region. Dangling graphene layers without the separation of a residual CNT wall are found to adhere to each other after failure with a distance of about 3.4 Å. This study provides a fundamental understanding of the tensile properties of the doped graphene–nanotube hybrid structures, which will benefit the design and also the applications of graphene-based hybrid materials.

  2. The doubly conditioned frequency spectrum does not distinguish between ancient population structure and hybridization

    KAUST Repository

    Eriksson, Anders

    2014-03-13

    Distinguishing between hybridization and population structure in the ancestral species is a key challenge in our understanding of how permeable species boundaries are to gene flow. The doubly conditioned frequency spectrum (dcfs) has been argued to be a powerful metric to discriminate between these two explanations, and it was used to argue for hybridization between Neandertal and anatomically modern humans. The shape of the observed dcfs for these two species cannot be reproduced by a model that represents ancient population structure in Africa with two populations, while adding hybridization produces realistic shapes. In this letter, we show that this result is a consequence of the spatial coarseness of the demographic model and that a spatially structured stepping stone model can generate realistic dcfs without hybridization. This result highlights how inferences on hybridization between recently diverged species can be strongly affected by the choice of how population structure is represented in the underlying demographic model. We also conclude that the dcfs has limited power in distinguishing between the signals left by hybridization and ancient structure. 2014 The Author.

  3. Magneto-fluorescent hybrid of dye and SPION with ordered and radially distributed porous structures

    Science.gov (United States)

    Gogoi, Madhulekha; Deb, Pritam

    2014-04-01

    We have reported the development of a silica based magneto-fluorescent hybrid of a newly synthesized dye and superparamagnetic iron oxide nanoparticles with ordered and radially distributed porous structure. The dye is synthesized by a novel yet simple synthetic approach based on Michael addition between dimer of glutaraldehyde and oleylamine molecule. The surfactant used for phase transformation of the dye from organic to aqueous phase, also acts as a structure directing agent for the porous structure evolution of the hybrid with radial distribution. The evolution of the radially distributed pores in the hybrids can be attributed to the formation of rod-like micelles containing nanoparticles, for concentration of micelles greater than critical micelle concentration. A novel water extraction method is applied to remove the surfactants resulting in the characteristic porous structure of the hybrid. Adsorption isotherm analysis confirms the porous nature of the hybrids with pore diameter ∼2.4 nm. A distinct modification in optical and magnetic property is observed due to interaction of the dye and SPION within the silica matrix. The integration of multiple structural components in the so developed hybrid nanosystem results into a potential agent for multifunctional biomedical application.

  4. Heterogeneous genome divergence, differential introgression, and the origin and structure of hybrid zones.

    Science.gov (United States)

    Harrison, Richard G; Larson, Erica L

    2016-06-01

    Hybrid zones have been promoted as windows on the evolutionary process and as laboratories for studying divergence and speciation. Patterns of divergence between hybridizing species can now be characterized on a genomewide scale, and recent genome scans have focused on the presence of 'islands' of divergence. Patterns of heterogeneous genomic divergence may reflect differential introgression following secondary contact and provide insights into which genome regions contribute to local adaptation, hybrid unfitness and positive assortative mating. However, heterogeneous genome divergence can also arise in the absence of any gene flow, as a result of variation in selection and recombination across the genome. We suggest that to understand hybrid zone origins and dynamics, it is essential to distinguish between genome regions that are divergent between pure parental populations and regions that show restricted introgression where these populations interact in hybrid zones. The latter, more so than the former, reveal the likely genetic architecture of reproductive isolation. Mosaic hybrid zones, because of their complex structure and multiple contacts, are particularly good subjects for distinguishing primary intergradation from secondary contact. Comparisons among independent hybrid zones or transects that involve the 'same' species pair can also help to distinguish between divergence with gene flow and secondary contact. However, data from replicate hybrid zones or replicate transects do not reveal consistent patterns; in a few cases, patterns of introgression are similar across independent transects, but for many taxa, there is distinct lack of concordance, presumably due to variation in environmental context and/or variation in the genetics of the interacting populations.

  5. Hybrid star structure with the Field Correlator Method

    Energy Technology Data Exchange (ETDEWEB)

    Burgio, G.F.; Zappala, D. [INFN, Catania (Italy)

    2016-03-15

    We explore the relevance of the color-flavor locking phase in the equation of state (EoS) built with the Field Correlator Method (FCM) for the description of the quark matter core of hybrid stars. For the hadronic phase, we use the microscopic Brueckner-Hartree-Fock (BHF) many-body theory, and its relativistic counterpart, i.e. the Dirac-Brueckner (DBHF). We find that the main features of the phase transition are directly related to the values of the quark-antiquark potential V{sub 1}, the gluon condensate G{sub 2} and the color-flavor superconducting gap Δ. We confirm that the mapping between the FCM and the CSS (constant speed of sound) parameterization holds true even in the case of paired quark matter. The inclusion of hyperons in the hadronic phase and its effect on the mass-radius relation of hybrid stars is also investigated. (orig.)

  6. Exact Solitary Wave Solution in the ZK-BBM Equation

    Directory of Open Access Journals (Sweden)

    Juan Zhao

    2014-01-01

    Full Text Available The traveling wave solution for the ZK-BBM equation is considered, which is governed by a nonlinear ODE system. The bifurcation structure of fixed points and bifurcation phase portraits with respect to the wave speed c are analyzed by using the dynamical system theory. Furthermore, the exact solutions of the homoclinic orbits for the nonlinear ODE system are obtained which corresponds to the solitary wave solution curve of the ZK-BBM equation.

  7. Trust and Contracting in Agri-Food Hybrid Structures

    OpenAIRE

    Martino, Gaetano

    2007-01-01

    The paper aims at examining the hypothesis that the influence of trust on contract can be thought of as a dynamic factor of organizational choices in supply chains. The relationship between contract and trust is delineated on the basis of institutional environment, contractual incompleteness, safeguards and restrictive provisions. The interaction between individual and system elements in the formation of trust and its influence in hybrid contracting is considered. According to a New Instituti...

  8. A generalized hybrid transfinite element computational approach for nonlinear/linear unified thermal/structural analysis

    Science.gov (United States)

    Tamma, Kumar K.; Railkar, Sudhir B.

    1987-01-01

    The present paper describes the development of a new hybrid computational approach for applicability for nonlinear/linear thermal structural analysis. The proposed transfinite element approach is a hybrid scheme as it combines the modeling versatility of contemporary finite elements in conjunction with transform methods and the classical Bubnov-Galerkin schemes. Applicability of the proposed formulations for nonlinear analysis is also developed. Several test cases are presented to include nonlinear/linear unified thermal-stress and thermal-stress wave propagations. Comparative results validate the fundamental capablities of the proposed hybrid transfinite element methodology.

  9. Optical fiber-based core-shell coaxially structured hybrid cells for self-powered nanosystems

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Caofeng; Zhu, Guang [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia (United States); Guo, Wenxi [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia (United States); State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Dong, Lin [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia (United States); School of Materials Science and Enginnering, Zhenzhou University, Zhenghou 450001 (China); Wang, Zhong Lin [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia (United States); Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing (China)

    2012-07-03

    An optical fiber-based 3D hybrid cell consisting of a coaxially structured dye-sensitized solar cell (DSSC) and a nanogenerator (NG) for simultaneously or independently harvesting solar and mechanical energy is demonstrated. The current output of the hybrid cell is dominated by the DSSC, and the voltage output is dominated by the NG; these can be utilized complementarily for different applications. The output of the hybrid cell is about 7.65 {mu}A current and 3.3 V voltage, which is strong enough to power nanodevices and even commercial electronic components. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Improved Thermoelectric Performance in Flexible Tellurium Nanowires/Reduced Graphene Oxide Sandwich Structure Hybrid Films

    Science.gov (United States)

    Gao, Jie; Liu, Chengyan; Miao, Lei; Wang, Xiaoyang; Peng, Ying; Chen, Yu

    2016-11-01

    With a high flexibility and an adjustable electronic structure, reduced graphene oxide (RGO) is a potential candidate for flexible thermoelectric materials. Here, we report that flexible RGO/tellurium nanowires (Te NWs)/RGO sandwich structure hybrid films are prepared on glass fabrics through the drop-cast method. The addition of 20 wt.% Te NWs into a RGO matrix remarkably improves the Seebeck coefficient from 15.2 μV/K to 89.7 μV/K while maintaining relatively high electrical conductivity, thus resulting in a one order of magnitude higher power factor value compared with the Te NWs. According to the values of carrier mobility and concentration of hybrid films, the improved thermoelectric properties are presented because of the energy filtering effect on the interfaces in hybrid films. This article suggests that RGO/Te NWs/RGO hybrid films would be promising for fabricating flexible energy sources.

  11. Structure improvement and electrochemical studies of bipolar nickel metal hydride batteries for hybrid electric vehicles

    Institute of Scientific and Technical Information of China (English)

    DENG Chao; SHI Peng-fei

    2006-01-01

    Nickel metal hydride battery in bipolar design offers some advantages for its application as a power storage system for electric and hybrid vehicles. This paper deals with the structure design and electrochemical studies of bipolar Ni/MH batteries for hybrid vehicles. An improvement is applied in bipolar battery design,and such bipolar Ni/MH batteries with 5 sub-cells have been assembled and investigated. Testing results show that bipolar batteries with improved structure have better compression tolerance and cycle performance than conventional ones. In addition, the improved bipolar batteries display excellent large current discharge ability and high power density. As simulating working conditions for hybrid vehicles, the batteries show good stability during pulse cycles, which verifies the possibility of being used as a power storage device on hybrid vehicles.

  12. Improved Thermoelectric Performance in Flexible Tellurium Nanowires/Reduced Graphene Oxide Sandwich Structure Hybrid Films

    Science.gov (United States)

    Gao, Jie; Liu, Chengyan; Miao, Lei; Wang, Xiaoyang; Peng, Ying; Chen, Yu

    2017-05-01

    With a high flexibility and an adjustable electronic structure, reduced graphene oxide (RGO) is a potential candidate for flexible thermoelectric materials. Here, we report that flexible RGO/tellurium nanowires (Te NWs)/RGO sandwich structure hybrid films are prepared on glass fabrics through the drop-cast method. The addition of 20 wt.% Te NWs into a RGO matrix remarkably improves the Seebeck coefficient from 15.2 μV/K to 89.7 μV/K while maintaining relatively high electrical conductivity, thus resulting in a one order of magnitude higher power factor value compared with the Te NWs. According to the values of carrier mobility and concentration of hybrid films, the improved thermoelectric properties are presented because of the energy filtering effect on the interfaces in hybrid films. This article suggests that RGO/Te NWs/RGO hybrid films would be promising for fabricating flexible energy sources.

  13. Solitary waves observed in the auroral zone: the Cluster multi-spacecraft perspective

    Directory of Open Access Journals (Sweden)

    J. S. Pickett

    2004-01-01

    Full Text Available We report on recent measurements of solitary waves made by the Wideband Plasma Wave Receiver located on each of the four Cluster spacecraft at 4.5-6.5RE (well above the auroral acceleration region as they cross field lines that map to the auroral zones. These solitary waves are observed in the Wideband data as isolated bipolar and tripolar waveforms. Examples of the two types of pulses are provided. The time durations of the majority of both types of solitary waves observed in this region range from about 0.3 up to 5ms. Their peak-to-peak amplitudes range from about 0.05 up to 20mV/m, with a few reaching up to almost 70mV/m. There is essentially no potential change across the bipolar pulses. There appears to be a small, measurable potential change, up to 0.5V, across the tripolar pulses, which is consistent with weak or hybrid double layers. A limited cross-spacecraft correlation study was carried out in order to identify the same solitary wave on more than one spacecraft. We found no convincing correlations of the bipolar solitary waves. In the two cases of possible correlation of the tripolar pulses, we found that the solitary waves are propagating at several hundred to a few thousand km/s and that they are possibly evolving (growing, decaying as they propagate from one spacecraft to the next. Further, they have a perpendicular (to the magnetic field width of 50km or greater and a parallel width of about 2-5km. We conclude, in general, however, that the Cluster spacecraft at separations along and perpendicular to the local magnetic field direction of tens of km and greater are too large to obtain positive correlations in this region. Looking at the macroscale of the auroral zone at 4.5-6.5RE, we find that the onsets of the broadband electrostatic noise associated with the solitary waves observed in the spectrograms of the WBD data are generally consistent with propagation of the solitary waves up the field lines (away from Earth, or with

  14. Novel fabrication technique of hybrid structure lens array for 3D images

    Science.gov (United States)

    Lee, Junsik; Kim, Junoh; Kim, Cheoljoong; Shin, Dooseub; Koo, Gyohyun; Won, Yong Hyub

    2016-03-01

    Tunable liquid lens arrays can produce three dimensional images by using electrowetting principle that alters surface tensions by applying voltage. This method has advantages of fast response time and low power consumption. However, it is challenging to fabricate a high fill factor liquid lens array and operate three dimensional images which demand high diopter. This study describes a hybrid structure lens array which has not only a liquid lens array but a solid lens array. A concave-shape lens array is unavoidable when using only the liquid lens array and some voltages are needed to make the lens flat. By placing the solid lens array on the liquid lens array, initial diopter can be positive. To fabricate the hybrid structure lens array, a conventional lithographic process in semiconductor manufacturing is needed. A negative photoresist SU-8 was used as chamber master molds. PDMS and UV adhesive replica molding are done sequentially. Two immiscible liquids, DI water and dodecane, are injected in the fabricated chamber, followed by sealing. The fabricated structure has a 20 by 20 pattern of cylindrical shaped circle array and the aperture size of each lens is 1mm. The thickness of the overall hybrid structure is about 2.8mm. Hybrid structure lens array has many advantages. Solid lens array has almost 100% fill factor and allow high efficiency. Diopter can be increased by more than 200 and negative diopter can be shifted to the positive region. This experiment showed several properties of the hybrid structure and demonstrated its superiority.

  15. Crystal Structure and Band Gap Engineering in Polyoxometalate-Based Inorganic-Organic Hybrids.

    Science.gov (United States)

    Roy, Soumyabrata; Sarkar, Sumanta; Pan, Jaysree; Waghmare, Umesh V; Dhanya, R; Narayana, Chandrabhas; Peter, Sebastian C

    2016-04-04

    We have demonstrated engineering of the electronic band gap of the hybrid materials based on POMs (polyoxometalates), by controlling its structural complexity through variation in the conditions of synthesis. The pH- and temperature-dependent studies give a clear insight into how these experimental factors affect the overall hybrid structure and its properties. Our structural manipulations have been successful in effectively tuning the optical band gap and electronic band structure of this kind of hybrids, which can find many applications in the field of photovoltaic and semiconducting devices. We have also addressed a common crystallographic disorder observed in Keggin-ion (one type of heteropolyoxometalate [POMs])-based hybrid materials. Through a combination of crystallographic, spectroscopic, and theoretical analysis of four new POM-based hybrids synthesized with tactically varied reaction conditions, we trace the origin and nature of the disorder associated with it and the subtle local structural coordination involved in its core picture. While the crystallography yields a centrosymmetric structure with planar coordination of Si, our analysis with XPS, IR, and Raman spectroscopy reveals a tetrahedral coordination with broken inversion symmetry, corroborated by first-principles calculations.

  16. The Doubly Conditioned Frequency Spectrum Does Not Distinguish between Ancient Population Structure and Hybridization

    OpenAIRE

    Eriksson, Anders; Manica, Andrea

    2014-01-01

    Distinguishing between hybridization and population structure in the ancestral species is a key challenge in our understanding of how permeable species boundaries are to gene flow. The doubly conditioned frequency spectrum (dcfs) has been argued to be a powerful metric to discriminate between these two explanations, and it was used to argue for hybridization between Neandertal and anatomically modern humans. The shape of the observed dcfs for these two species cannot be reproduced by a model ...

  17. Nanoscale Structure of Self-Assembling Hybrid Materials of Inorganic and Electronically Active Organic Phases

    Energy Technology Data Exchange (ETDEWEB)

    Sofos, M.; Goswami, D.A. Stone D.K.; Okasinski, J.S.; Jin, H.; Bedzyk, M.J.; Stupp, S.I. (NWU)

    2008-10-06

    Hybrid materials with nanoscale structure that incorporates inorganic and organic phases with electronic properties offer potential in an extensive functional space that includes photovoltaics, light emission, and sensing. This work describes the nanoscale structure of model hybrid materials with phases of silica and electronically active bola-amphiphile assemblies containing either oligo(p-phenylene vinylene) or oligo(thiophene) segments. The hybrid materials studied here were synthesized by evaporation-induced self-assembly and characterized by X-ray scattering techniques. Grazing-incidence X-ray scattering studies of these materials revealed the formation of two-dimensional hexagonally packed cylindrical micelles of the organic molecules with diameters between 3.1 and 3.6 nm and cylindrical axes parallel to the surface. During the self-assembly process at low pH, the cylindrical aggregates of conjugated molecules become surrounded by silica giving rise to a hybrid structure with long-range order. Specular X-ray reflectivity confirmed the long-range periodicity of the hybrid films within a specific range of molar ratios of tetraethyl orthosilicate to cationic amphiphile. We did not observe any long-range ordering in fully organic analogues unless quaternary ammonium groups were replaced by tertiary amines. These observations suggest that charge screening in these biscationic conjugated molecules by the mineral phase is a key factor in the evolution of long range order in the self-assembling hybrids.

  18. Enhanced non-radiative energy transfer in hybrid III-nitride structures

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R. M.; Athanasiou, M.; Bai, J.; Liu, B.; Wang, T., E-mail: t.wang@sheffield.ac.uk [Department of Electrical and Electronic Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom)

    2015-09-21

    The effect of surface states has been investigated in hybrid organic/inorganic white light emitting structures that employ high efficiency, nearfield non-radiative energy transfer (NRET) coupling. The structures utilize blue emitting InGaN/GaN multiple quantum well (MQW) nanorod arrays to minimize the separation with a yellow emitting F8BT coating. Surface states due to the exposed III-nitride surfaces of the nanostructures are found to reduce the NRET coupling rate. The surface states are passivated by deposition of a silicon nitride layer on the III-nitride nanorod surface leading to reduced surface recombination. A low thickness surface passivation is shown to increase the NRET coupling rate by 4 times compared to an un-passivated hybrid structure. A model is proposed to explain the increased NRET rate for the passivated hybrid structures based on the reduction in surface electron depletion of the passivated InGaN/GaN MQW nanorods surfaces.

  19. Enhanced non-radiative energy transfer in hybrid III-nitride structures

    Science.gov (United States)

    Smith, R. M.; Athanasiou, M.; Bai, J.; Liu, B.; Wang, T.

    2015-09-01

    The effect of surface states has been investigated in hybrid organic/inorganic white light emitting structures that employ high efficiency, nearfield non-radiative energy transfer (NRET) coupling. The structures utilize blue emitting InGaN/GaN multiple quantum well (MQW) nanorod arrays to minimize the separation with a yellow emitting F8BT coating. Surface states due to the exposed III-nitride surfaces of the nanostructures are found to reduce the NRET coupling rate. The surface states are passivated by deposition of a silicon nitride layer on the III-nitride nanorod surface leading to reduced surface recombination. A low thickness surface passivation is shown to increase the NRET coupling rate by 4 times compared to an un-passivated hybrid structure. A model is proposed to explain the increased NRET rate for the passivated hybrid structures based on the reduction in surface electron depletion of the passivated InGaN/GaN MQW nanorods surfaces.

  20. Anomalous width variation of rarefactive ion acoustic solitary waves in the context of auroral plasmas

    Directory of Open Access Journals (Sweden)

    S. S. Ghosh

    2004-01-01

    Full Text Available The presence of dynamic, large amplitude solitary waves in the auroral regions of space is well known. Since their velocities are of the order of the ion acoustic speed, they may well be considered as being generated from the nonlinear evolution of ion acoustic waves. However, they do not show the expected width-amplitude correlation for K-dV solitons. Recent POLAR observations have actually revealed that the low altitude rarefactive ion acoustic solitary waves are associated with an increase in the width with increasing amplitude. This indicates that a weakly nonlinear theory is not appropriate to describe the solitary structures in the auroral regions. In the present work, a fully nonlinear analysis based on Sagdeev pseudopotential technique has been adopted for both parallel and oblique propagation of rarefactive solitary waves in a two electron temperature multi-ion plasma. The large amplitude solutions have consistently shown an increase in the width with increasing amplitude. The width-amplitude variation profile of obliquely propagating rarefactive solitary waves in a magnetized plasma have been compared with the recent POLAR observations. The width-amplitude variation pattern is found to fit well with the analytical results. It indicates that a fully nonlinear theory of ion acoustic solitary waves may well explain the observed anomalous width variations of large amplitude structures in the auroral region.

  1. Fabrication and characterization of materials and structures for hybrid organic-inorganic photonics

    Science.gov (United States)

    Haško, Daniel; Chovan, Jozef; Uherek, František

    2017-03-01

    Hybrid organic-inorganic integrated photonics integrate the organic material, as a part of active layer, with inorganic structure, and it is the organic component that extends the functionalities as compared to inorganic photonics. This paper presents the results of fabrication and characterization of inorganic and organic layers, as well as of hybrid organic-inorganic structures. Inorganic oxide and nitride materials and structures were grown using plasma enhanced chemical vapor deposition. As a substrate for tested organic layers and for preparation of multilayer structures, commercially available SiO2 created by thermal oxidation on Si was used. The hybrid organic-inorganic structures were prepared by spin coating of organic materials on SiO2/Si inorganic structures. As the basic photonics devices, the testing strip inorganic and organic waveguides were fabricated using reactive ion etching. The shape of fabricated testing waveguides was trapezoidal and etched structures were able to guide the radiation. The presented technology enabled to prepare hybrid organic-inorganic structures of comparable dimensions and shape. The fabricated waveguides dimensions and shape will be used for optimisation and design of new lithographic mask to prepare photonic components with required characteristics.

  2. Efficient light emission from inorganic and organic semiconductor hybrid structures by energy-level tuning.

    Science.gov (United States)

    Schlesinger, R; Bianchi, F; Blumstengel, S; Christodoulou, C; Ovsyannikov, R; Kobin, B; Moudgil, K; Barlow, S; Hecht, S; Marder, S R; Henneberger, F; Koch, N

    2015-04-15

    The fundamental limits of inorganic semiconductors for light emitting applications, such as holographic displays, biomedical imaging and ultrafast data processing and communication, might be overcome by hybridization with their organic counterparts, which feature enhanced frequency response and colour range. Innovative hybrid inorganic/organic structures exploit efficient electrical injection and high excitation density of inorganic semiconductors and subsequent energy transfer to the organic semiconductor, provided that the radiative emission yield is high. An inherent obstacle to that end is the unfavourable energy level offset at hybrid inorganic/organic structures, which rather facilitates charge transfer that quenches light emission. Here, we introduce a technologically relevant method to optimize the hybrid structure's energy levels, here comprising ZnO and a tailored ladder-type oligophenylene. The ZnO work function is substantially lowered with an organometallic donor monolayer, aligning the frontier levels of the inorganic and organic semiconductors. This increases the hybrid structure's radiative emission yield sevenfold, validating the relevance of our approach.

  3. Absorption enhancement and total absorption in a graphene-waveguide hybrid structure

    Science.gov (United States)

    Guo, Jun; Wu, Leiming; Dai, Xiaoyu; Xiang, Yuanjiang; Fan, Dianyuan

    2017-02-01

    We propose a graphene/planar waveguide hybrid structure, and demonstrate total absorption in the visible wavelength range by means of attenuated total reflectance. The excitation of planar waveguide mode, which has strong near field enhancement and increased light interaction length with graphene, plays a vital role in total absorption. We analyze the origin and physical insight of total absorption theoretically by using an approximated reflectance, and show how to design such hybrid structure numerically. Utilizing the tunability of doped graphene, we discuss the possible application in optical modulators. We also achieve broadband absorption enhancement in near-IR range by cascading multiple graphene-waveguide hybrid structures. We believe our results will be useful not only for potential applications in optical devices, but also for studying other two-dimension materials.

  4. Absorption enhancement and total absorption in a graphene-waveguide hybrid structure

    Directory of Open Access Journals (Sweden)

    Jun Guo

    2017-02-01

    Full Text Available We propose a graphene/planar waveguide hybrid structure, and demonstrate total absorption in the visible wavelength range by means of attenuated total reflectance. The excitation of planar waveguide mode, which has strong near field enhancement and increased light interaction length with graphene, plays a vital role in total absorption. We analyze the origin and physical insight of total absorption theoretically by using an approximated reflectance, and show how to design such hybrid structure numerically. Utilizing the tunability of doped graphene, we discuss the possible application in optical modulators. We also achieve broadband absorption enhancement in near-IR range by cascading multiple graphene-waveguide hybrid structures. We believe our results will be useful not only for potential applications in optical devices, but also for studying other two-dimension materials.

  5. Electronic band structure effects in monolayer, bilayer, and hybrid graphene structures

    Science.gov (United States)

    Puls, Conor

    Since its discovery in 2005, graphene has been the focus of intense theoretical and experimental study owing to its unique two-dimensional band structure and related electronic properties. In this thesis, we explore the electronic properties of graphene structures from several perspectives including the magnetoelectrical transport properties of monolayer graphene, gap engineering and measurements in bilayer graphene, and anomalous quantum oscillation in the monolayer-bilayer graphene hybrids. We also explored the device implications of our findings, and the application of some experimental techniques developed for the graphene work to the study of a complex oxide, Ca3Ru2O7, exhibiting properties of strongly correlated electrons. Graphene's high mobility and ballistic transport over device length scales, make it suitable for numerous applications. However, two big challenges remain in the way: maintaining high mobility in fabricated devices, and engineering a band gap to make graphene compatible with logical electronics and various optical devices. We address the first challenge by experimentally evaluating mobilities in scalable monolayer graphene-based field effect transistors (FETs) and dielectric-covered Hall bars. We find that the mobility is limited in these devices, and is roughly inversely proportional to doping. By considering interaction of graphene's Dirac fermions with local charged impurities at the interface between graphene and the top-gate dielectric, we find that Coulomb scattering is responsible for degraded mobility. Even in the cleanest devices, a band gap is still desirable for electronic applications of graphene. We address this challenge by probing the band structure of bilayer graphene, in which a field-tunable energy band gap has been theoretically proposed. We use planar tunneling spectroscopy of exfoliated bilayer graphene flakes demonstrate both measurement and control of the energy band gap. We find that both the Fermi level and

  6. CVD growth of graphene under exfoliated hexagonal boron nitride for vertical hybrid structures

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Min [SKKU Advanced Institute of Nanotechnology (SAINT) (Korea, Republic of); Center for Human Interface Nanotechnology (HINT) (Korea, Republic of); Jang, Sung Kyu [SKKU Advanced Institute of Nanotechnology (SAINT) (Korea, Republic of); Song, Young Jae [SKKU Advanced Institute of Nanotechnology (SAINT) (Korea, Republic of); Department of Physics, Sungkyunkwan University (SKKU), Suwon 440-746 (Korea, Republic of); Lee, Sungjoo, E-mail: leesj@skku.edu [SKKU Advanced Institute of Nanotechnology (SAINT) (Korea, Republic of); Center for Human Interface Nanotechnology (HINT) (Korea, Republic of); College of Information and Communication Engineering, Sungkyunkwan University (SKKU), Suwon 440-746 (Korea, Republic of)

    2015-01-15

    Graphical abstract: We have demonstrated a novel yet simple method for fabricating graphene-based vertical hybrid structures by performing the CVD growth of graphene at an h-BN/Cu interface. Our systematic Raman measurements combined with plasma etching process indicate that a graphene film is grown under exfoliated h-BN rather than on its top surface, and that an h-BN/graphene vertical hybrid structure has been fabricated. Electrical transport measurements of this h-BN/graphene, transferred on SiO2, show the carrier mobility up to approximately 2250 cm{sup 2} V{sup −1} s{sup −1}. The developed method would enable the exploration of the possibility of novel hybrid structure integration with two-dimensional material systems. - Abstract: We have demonstrated a novel yet simple method for fabricating graphene-based vertical hybrid structures by performing the CVD growth of graphene at an h-BN/Cu interface. Our systematic Raman measurements combined with plasma etching process indicate that a graphene film is grown under exfoliated h-BN rather than on its top surface, and that an h-BN/graphene vertical hybrid structure has been fabricated. Electrical transport measurements of this h-BN/graphene, transferred on SiO{sub 2}, show the carrier mobility up to approximately 2250 cm{sup 2} V{sup −1} s{sup −1}. The developed method would enable the exploration of the possibility of novel hybrid structure integration with two-dimensional material systems.

  7. Transversally periodic solitary gravity–capillary waves

    Science.gov (United States)

    Milewski, Paul A.; Wang, Zhan

    2014-01-01

    When both gravity and surface tension effects are present, surface solitary water waves are known to exist in both two- and three-dimensional infinitely deep fluids. We describe here solutions bridging these two cases: travelling waves which are localized in the propagation direction and periodic in the transverse direction. These transversally periodic gravity–capillary solitary waves are found to be of either elevation or depression type, tend to plane waves below a critical transverse period and tend to solitary lumps as the transverse period tends to infinity. The waves are found numerically in a Hamiltonian system for water waves simplified by a cubic truncation of the Dirichlet-to-Neumann operator. This approximation has been proved to be very accurate for both two- and three-dimensional computations of fully localized gravity–capillary solitary waves. The stability properties of these waves are then investigated via the time evolution of perturbed wave profiles. PMID:24399922

  8. Solitary Fibrous Tumor of the Uterus

    Directory of Open Access Journals (Sweden)

    Po-Wei Chu

    2006-12-01

    Conclusion: The behavior of solitary fibrous tumors arising from the uterus is difficult to evaluate; therefore, complete surgical excision featuring clear margins and comprehensive follow-up is recommended.

  9. Management of the Solitary Pulmonary Nodule.

    Science.gov (United States)

    Chan, Edward Y; Gaur, Puja; Ge, Yimin; Kopas, Lisa; Santacruz, Jose F; Gupta, Nakul; Munden, Reginald F; Cagle, Philip T; Kim, Min P

    2016-09-02

    Context .- Optimal management of the patient with a solitary pulmonary nodule entails early diagnosis and appropriate treatment for patients with malignant tumors, and minimization of unnecessary interventions and procedures for those with ultimately benign nodules. With the growing number of high-resolution imaging modalities and studies available, incidentally found solitary pulmonary nodules are an increasingly common occurrence. Objective .- To provide guidance to clinicians involved in the management of patients with a solitary pulmonary nodule, including aspects of risk stratification, workup, diagnosis, and management. Data Sources .- Data for this review were gathered from an extensive literature review on the topic. Conclusions .- Logical evaluation and management pathways for a patient with a solitary pulmonary nodule will allow providers to diagnose and treat individuals with early stage lung cancer and minimize morbidity from invasive procedures for patients with benign lesions.

  10. Effect of dust charge variation on dust—acoustic solitary waves in a magnetized two—ion—temperature dusty plasma

    Institute of Scientific and Technical Information of China (English)

    XueJu-Kui; LangHe

    2003-01-01

    The effect of dust charge variation on the dust-acoustic solitary structures is investigated in a warm magnetized two-ion-temperature dusty plasma consisting of a negatively and variably charged extremely massive dust fluid and ions of two different temperatures. It is shown that the dust charge variation as well as the presence of a second component of ions would modify the properties of the dust-acoustic solitary structures and may exite both dust-acoustic solitary holes (soliton waves with a density dip) and positive solitons (soliton waves with a density hump).

  11. Effect of dust charge variation on dust-acoustic solitary waves in a magnetized two-ion-temperature dusty plasma

    Institute of Scientific and Technical Information of China (English)

    薛具奎; 郎和

    2003-01-01

    The effect of dust charge variation on the dust-acoustic solitary structures is investigated in a warm magnetized two-ion-temperature dusty plasma consisting of a negatively and variably charged extremely massive dust fluid and ions of two different temperatures. It is shown that the dust charge variation as well as the presence of a second component of ions would modify the properties of the dust-acoustic solitary structures and may excite both dust-acoustic solitary holes (soliton waves with a density dip) and positive solitons (soliton waves with a density hump).

  12. Sampling Enrichment toward Target Structures Using Hybrid Molecular Dynamics-Monte Carlo Simulations.

    Science.gov (United States)

    Yang, Kecheng; Różycki, Bartosz; Cui, Fengchao; Shi, Ce; Chen, Wenduo; Li, Yunqi

    2016-01-01

    Sampling enrichment toward a target state, an analogue of the improvement of sampling efficiency (SE), is critical in both the refinement of protein structures and the generation of near-native structure ensembles for the exploration of structure-function relationships. We developed a hybrid molecular dynamics (MD)-Monte Carlo (MC) approach to enrich the sampling toward the target structures. In this approach, the higher SE is achieved by perturbing the conventional MD simulations with a MC structure-acceptance judgment, which is based on the coincidence degree of small angle x-ray scattering (SAXS) intensity profiles between the simulation structures and the target structure. We found that the hybrid simulations could significantly improve SE by making the top-ranked models much closer to the target structures both in the secondary and tertiary structures. Specifically, for the 20 mono-residue peptides, when the initial structures had the root-mean-squared deviation (RMSD) from the target structure smaller than 7 Å, the hybrid MD-MC simulations afforded, on average, 0.83 Å and 1.73 Å in RMSD closer to the target than the parallel MD simulations at 310K and 370K, respectively. Meanwhile, the average SE values are also increased by 13.2% and 15.7%. The enrichment of sampling becomes more significant when the target states are gradually detectable in the MD-MC simulations in comparison with the parallel MD simulations, and provide >200% improvement in SE. We also performed a test of the hybrid MD-MC approach in the real protein system, the results showed that the SE for 3 out of 5 real proteins are improved. Overall, this work presents an efficient way of utilizing solution SAXS to improve protein structure prediction and refinement, as well as the generation of near native structures for function annotation.

  13. Hybrid experimental/analytical models of structural dynamics - Creation and use for predictions

    Science.gov (United States)

    Balmes, Etienne

    1993-01-01

    An original complete methodology for the construction of predictive models of damped structural vibrations is introduced. A consistent definition of normal and complex modes is given which leads to an original method to accurately identify non-proportionally damped normal mode models. A new method to create predictive hybrid experimental/analytical models of damped structures is introduced, and the ability of hybrid models to predict the response to system configuration changes is discussed. Finally a critical review of the overall methodology is made by application to the case of the MIT/SERC interferometer testbed.

  14. Compact hybrid cell based on a convoluted nanowire structure for harvesting solar and mechanical energy

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Chen; Wang, Zhong Lin [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States)

    2011-02-15

    A fully integrated, solid-state, compact hybrid cell (CHC) that comprises ''convoluted'' ZnO nanowire structures for concurrent harvesting of both solar and mechanical energy is demonstrated. The compact hybrid cell is based on a conjunction design of an organic solid-state dye-sensitized solar cell (DSSC) and piezoelectric nanogenerator in one compact structure. The CHC shows a significant increase in output power, clearly demonstrating its potential for simultaneously harvesting multiple types of energy for powering small electronic devices for independent, sustainable, and mobile operation. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Hybrid local FEM/global LISA modeling of damped guided wave propagation in complex composite structures

    Science.gov (United States)

    Shen, Yanfeng; Cesnik, Carlos E. S.

    2016-09-01

    This paper presents a new hybrid modeling technique for the efficient simulation of guided wave generation, propagation, and interaction with damage in complex composite structures. A local finite element model is deployed to capture the piezoelectric effects and actuation dynamics of the transmitter, while the global domain wave propagation and interaction with structural complexity (structure features and damage) are solved utilizing a local interaction simulation approach (LISA). This hybrid approach allows the accurate modeling of the local dynamics of the transducers and keeping the LISA formulation in an explicit format, which facilitates its readiness for parallel computing. The global LISA framework was extended through the 3D Kelvin-Voigt viscoelasticity theory to include anisotropic damping effects for composite structures, as an improvement over the existing LISA formulation. The global LISA framework was implemented using the compute unified device architecture running on graphic processing units. A commercial preprocessor is integrated seamlessly with the computational framework for grid generation and material property allocation to handle complex structures. The excitability and damping effects are successfully captured by this hybrid model, with experimental validation using the scanning laser doppler vibrometry. To demonstrate the capability of our hybrid approach for complex structures, guided wave propagation and interaction with a delamination in a composite panel with stiffeners is presented.

  16. Conservative numerical methods for solitary wave interactions

    Energy Technology Data Exchange (ETDEWEB)

    Duran, A; Lopez-Marcos, M A [Departamento de Matematica Aplicada y Computacion, Facultad de Ciencias, Universidad de Valladolid, Paseo del Prado de la Magdalena s/n, 47005 Valladolid (Spain)

    2003-07-18

    The purpose of this paper is to show the advantages that represent the use of numerical methods that preserve invariant quantities in the study of solitary wave interactions for the regularized long wave equation. It is shown that the so-called conservative methods are more appropriate to study the phenomenon and provide a dynamic point of view that allows us to estimate the changes in the parameters of the solitary waves after the collision.

  17. First-Principles Study of Electronic Structure of Type I Hybrid Carbon-Silicon Clathrates

    Science.gov (United States)

    Chan, Kwai S.; Peng, Xihong

    2016-08-01

    A new class of type I hybrid carbon-silicon clathrates has been designed using computational methods by substituting some of the Si atoms in the silicon clathrate framework with carbon atoms. In this work, the electronic structure of hybrid carbon-silicon clathrates with and without alkaline or alkaline-earth metal guest atoms has been computed within the density functional theory framework. The theoretical calculations indicate that a small number of carbon substitutions in the Si46 framework slightly reduces the density of states (DOS) near the band edge and narrows the bandgap of carbon-silicon clathrates. Weak hybridization of the conduction band occurs when alkaline metal (Li, Na, K) atoms are inserted into the structure, while strong hybridization of the conduction band occurs when alkaline-earth metal (Mg, Ca, Ba) atoms are inserted into the hybrid structure. Empty C y Si46- y clathrates within the composition range of 2 ≤ y ≤ 15 can be tuned to exhibit indirect bandgaps of 1.5 eV or less, and may be considered as potential electronic materials.

  18. A Novel Organophosphorus Hybrid with Excellent Thermal Stability: Core-Shell Structure, Hybridization Mechanism, and Application in Flame Retarding Semi-Aromatic Polyamide.

    Science.gov (United States)

    Lin, Xue-Bao; Du, Shuang-Lan; Long, Jia-Wei; Chen, Li; Wang, Yu-Zhong

    2016-01-13

    An organophosphorous hybrid (BM@Al-PPi) with unique core-shell structure was prepared through hybridization reaction between boehmite (BM) as the inorganic substrate and phenylphosphinic acid (PPiA) as the organic modifier. Fourier transform infrared spectra (FTIR), solid state (31)P and (27)Al magic angle spinning nuclear magnetic resonance, X-ray diffraction, and element analysis were used to investigate the chemical structure of the hybrids, where the microrod-like core was confirmed as Al-PPi aggregates generated from the reaction between BM and PPiA, and those irregular nanoparticles in the shell belonged to residual BM. Compared with the traditional dissolution-precipitation process, a novel analogous suspension reaction mode was proposed to explain the hybridization process and the resulting product. Scanning electronic microscopy further proved the core-shell structure of the hybrids. BM exhibited much higher initial decomposition temperature than that of Al-PPi; therefore, the hybrid showed better thermal stability than Al-PPi, and it met the processing temperature of semi-aromatic polyamide (HTN, for instance) as an additive-type flame retardant. Limiting oxygen index and cone calorimetric analysis suggested the excellent flame-retardant performance and smoke suppressing activity by adding the resulting hybrid into HTN.

  19. Structural Synthesis of a Class of 2R2T Hybrid Mechanisms

    Institute of Scientific and Technical Information of China (English)

    TIAN Chunxu; FANG Yuefa; GUO Sheng

    2016-01-01

    Conventional overconstrained parallel manipulators have been widely studied both in industry and academia, however the structural synthesis of hybrid mechanisms with additional constraints is seldom studied, especially for the four degrees of freedom(DOF) hybrid mechanisms. In order to develop a manipulator with additional constraints, a class of important spatial mechanisms with coupling chains(CCs) whose motion type is two rotations and two translations(2R2T) is presented. Based on screw theory, the combination of different types of limbs which are used to construct parallel mechanisms and coupling chains is proposed. The basic types of the general parallel mechanisms and geometric conditions of the kinematic chains are given using constraint synthesis method. Moreover, the 2R2T motion pattern hybrid mechanisms which are derived by adding coupling chains between different serial kinematic chains(SKCs) of the corresponding parallel mechanisms are presented. According to the constraint analysis of the mechanisms, the movement relationship of the moving platform and the kinematic chains is derived by disassembling the coupling chains. At last, fourteen novel hybrid mechanisms with two or three serial kinematic chains are presented. The proposed novel hybrid mechanisms and construction method enrich the family of the spatial mechanisms and provide an instruction to design more complex hybrid mechanisms.

  20. Efficient Hybrid White Organic Light-Emitting Diodes for Application of Triplet Harvesting with Simple Structure

    CERN Document Server

    Hwang, Kyo Min; Lee, Sungkyu; Yoo, Han Kyu; Baek, Hyun Jung; Kim, Jwajin; Yoon, Seung Soo; Kim, Young Kwan

    2016-01-01

    In this study, we fabricated hybrid white organic light-emitting diodes (WOLEDs) based on triplet harvesting with simple structure. All the hole transporting material and host in emitting layer (EML) of devices were utilized with same material by using N,N'-di-1-naphthalenyl-N,N'-diphenyl-[1,1':4',1":4",1"'-quaterphenyl]-4,4"'-diamine (4P-NPD) which were known to be blue fluorescent material. Simple hybrid WOLEDs were fabricated three color with blue fluorescent and green, red phosphorescent materials. We was investigated the effect of triplet harvesting (TH) by exciton generation zone on simple hybrid WOLEDs. Characteristic of simple hybrid WOLEDs were dominant hole mobility, therefore exciton generation zone was expected in EML. Additionally, we was optimization thickness of hole transporting layer and electron transporting layer was fabricated a simple hybrid WOLEDs. Simple hybrid WOLED exhibits maximum luminous efficiency of 29.3 cd/A and maximum external quantum efficiency of 11.2%. Commission Internatio...

  1. Structural synthesis of a class of 2R2T hybrid mechanisms

    Science.gov (United States)

    Tian, Chunxu; Fang, Yuefa; Guo, Sheng

    2016-07-01

    Conventional overconstrained parallel manipulators have been widely studied both in industry and academia, however the structural synthesis of hybrid mechanisms with additional constraints is seldom studied, especially for the four degrees of freedom(DOF) hybrid mechanisms. In order to develop a manipulator with additional constraints, a class of important spatial mechanisms with coupling chains(CCs) whose motion type is two rotations and two translations(2R2T) is presented. Based on screw theory, the combination of different types of limbs which are used to construct parallel mechanisms and coupling chains is proposed. The basic types of the general parallel mechanisms and geometric conditions of the kinematic chains are given using constraint synthesis method. Moreover, the 2R2T motion pattern hybrid mechanisms which are derived by adding coupling chains between different serial kinematic chains(SKCs) of the corresponding parallel mechanisms are presented. According to the constraint analysis of the mechanisms, the movement relationship of the moving platform and the kinematic chains is derived by disassembling the coupling chains. At last, fourteen novel hybrid mechanisms with two or three serial kinematic chains are presented. The proposed novel hybrid mechanisms and construction method enrich the family of the spatial mechanisms and provide an instruction to design more complex hybrid mechanisms.

  2. A Carbon-Sulfur Hybrid with Pomegranate-like Structure for Lithium-Sulfur Batteries.

    Science.gov (United States)

    Shi, Yanting; Lv, Wei; Niu, Shuzhang; He, Yanbing; Zhou, Guangmin; Chen, Guohua; Li, Baohua; Yang, Quan-Hong; Kang, Feiyu

    2016-05-01

    A carbon-sulfur hybrid with pomegranate-like core-shell structure, which demonstrates a high rate performance and relatively high cyclic stability, is obtained through carbonization of a carbon precursor in the presence of a sulfur precursor (FeS2 ) and a following oxidation of FeS2 to sulfur by HNO3 . Such a structure effectively protects the sulfur and leaves enough buffer space after Fe(3+) removal and, at the same time, has an interconnected conductive network. The capacity of the obtained hybrid is 450 mA h g(-1) under the current density of 5 C. This work provides a simple strategy to design and prepare various high-performance carbon-sulfur hybrids for lithium-sulfur batteries.

  3. Ultracompact resonator with high quality-factor based on a hybrid grating structure

    DEFF Research Database (Denmark)

    Taghizadeh, Alireza; Mørk, Jesper; Chung, Il-Sug

    2015-01-01

    We numerically investigate the properties of a hybrid grating structure acting as a resonator with ultrahigh quality factor. This reveals that the physical mechanism responsible for the resonance is quite different from the conventional guided mode resonance (GMR). The hybrid grating consists...... of a subwavelength grating layer and an un-patterned high-refractive-index cap layer, being surrounded by low index materials. Since the cap layer may include a gain region, an ultracompact laser can be realized based on the hybrid grating resonator, featuring many advantages over high-contrast-grating resonator...... lasers. The effect of fabrication errors and finite size of the structure is investigated to understand the feasibility of fabricating the proposed resonator....

  4. Fast structural design and analysis via hybrid domain decomposition on massively parallel processors

    Science.gov (United States)

    Farhat, Charbel

    1993-01-01

    A hybrid domain decomposition framework for static, transient and eigen finite element analyses of structural mechanics problems is presented. Its basic ingredients include physical substructuring and /or automatic mesh partitioning, mapping algorithms, 'gluing' approximations for fast design modifications and evaluations, and fast direct and preconditioned iterative solvers for local and interface subproblems. The overall methodology is illustrated with the structural design of a solar viewing payload that is scheduled to fly in March 1993. This payload has been entirely designed and validated by a group of undergraduate students at the University of Colorado using the proposed hybrid domain decomposition approach on a massively parallel processor. Performance results are reported on the CRAY Y-MP/8 and the iPSC-860/64 Touchstone systems, which represent both extreme parallel architectures. The hybrid domain decomposition methodology is shown to outperform leading solution algorithms and to exhibit an excellent parallel scalability.

  5. 17.6%-Efficient radial junction solar cells using silicon nano/micro hybrid structures

    Science.gov (United States)

    Lee, Kangmin; Hwang, Inchan; Kim, Namwoo; Choi, Deokjae; Um, Han-Don; Kim, Seungchul; Seo, Kwanyong

    2016-07-01

    We developed a unique nano- and microwire hybrid structure by selectively modifying only the tops of microwires using metal-assisted chemical etching. The proposed nano/micro hybrid structure not only minimizes surface recombination but also absorbs 97% of incident light under AM 1.5G illumination, demonstrating outstanding light absorption compared to that of planar (59%) and microwire arrays (85%). The proposed hybrid solar cells with an area of 1 cm2 exhibit power conversion efficiencies (Eff) of up to 17.6% under AM 1.5G illumination. In particular, the solar cells show a high short-circuit current density (Jsc) of 39.5 mA cm-2 because of the high light-absorbing characteristics of the nanostructures. This corresponds to an approximately 61.5% and 16.5% increase in efficiency compared to that of a planar silicon solar cell (Eff = 10.9%) and a microwire solar cell (Eff = 15.1%), respectively. Therefore, we expect the proposed hybrid structure to become a foundational technology for the development of highly efficient radial junction solar cells.We developed a unique nano- and microwire hybrid structure by selectively modifying only the tops of microwires using metal-assisted chemical etching. The proposed nano/micro hybrid structure not only minimizes surface recombination but also absorbs 97% of incident light under AM 1.5G illumination, demonstrating outstanding light absorption compared to that of planar (59%) and microwire arrays (85%). The proposed hybrid solar cells with an area of 1 cm2 exhibit power conversion efficiencies (Eff) of up to 17.6% under AM 1.5G illumination. In particular, the solar cells show a high short-circuit current density (Jsc) of 39.5 mA cm-2 because of the high light-absorbing characteristics of the nanostructures. This corresponds to an approximately 61.5% and 16.5% increase in efficiency compared to that of a planar silicon solar cell (Eff = 10.9%) and a microwire solar cell (Eff = 15.1%), respectively. Therefore, we expect the

  6. A LINEAR HYBRID MODEL OF MSE AND BEM FOR FLOATING STRUCTURES IN COASTAL ZONES

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun; MIAO Guo-ping

    2006-01-01

    A linear hybrid model of Mild Slope Equation (MSE) and Boundary Element Method (BEM) is developed to study the wave propagation around floating structures in coastal zones. Both the wave refraction under the influence of topography and the wave diffraction by floating structures are considered. Hence, the model provides wave properties around the coastal floating structures of arbitrary shape but also the wave forces on and the hydrodynamic characteristics of the structures. Different approaches are compared to demonstrate the validity of the present hybrid model. Several numerical tests are carried out for the cases of pontoons under different circumstances. The results show that the influence of topography on the hydrodynamic characteristics of floating structures in coastal regions is important and must not be ignored in the most wave period range with practical interests.

  7. Optimal design of structures for earthquake loads by a hybrid RBF-BPSO method

    Institute of Scientific and Technical Information of China (English)

    Eysa Salajegheh; Saeed Gholizadeh; Mohsen Khatibina

    2008-01-01

    The optimal seismic design of structures requires that time history analyses (THA) be carried out repeatedly. This makes the optimal design process inefficient, in particular, if an evolutionary algorithm is used. To reduce the overall time required for structural optimization, two artificial intelligence strategies are employed. In the first strategy, radial basis function (RBF) neural networks are used to predict the time history responses of structures in the optimization flow. In the second strategy, a binary particle swarm optimization (BPSO) is used to find the optimum design. Combining the RBF and BPSO, a hybrid RBF-BPSO optimization method is proposed in this paper, which achieves fast optimization with high computational performance. Two examples are presented and compared to determine the optimal weight of structures under earthquake loadings using both exact and approximate analyses. The numerical results demonstrate the computational advantages and effectiveness of the proposed hybrid RBF-BPSO optimization method for the seismic design of structures.

  8. A hybrid method for identification of structural domains

    Science.gov (United States)

    Hua, Yongpan; Zhu, Min; Wang, Yuelong; Xie, Zhaoyang; Li, Menglong

    2014-12-01

    Structural domains in proteins are the basic units to form various proteins. In the protein's evolution and functioning, domains play important roles. But the definition of domain is not yet precisely given, and the update cycle of structural domain databases is long. The automatic algorithms identify domains slowly, while protein entities with great structural complexity are on the rise. Here, we present a method which recognizes the compact and modular segments of polypeptide chains to identify structural domains, and contrast some data sets to illuminate their effect. The method combines support vector machine (SVM) with K-means algorithm. It is faster and more stable than most current algorithms and performs better. It also indicates that when proteins are presented as some Alpha-carbon atoms in 3D space, it is feasible to identify structural domains by the spatially structural properties. We have developed a web-server, which would be helpful in identification of structural domains (http://vis.sculab.org/~huayongpan/cgi-bin/domainAssignment.cgi).

  9. Bifurcations of ion acoustic solitary and periodic waves in an electron-positron-ion plasma through non-perturbative approach

    Science.gov (United States)

    Saha, Asit; Chatterjee, Prasanta; Chatterjee

    2014-08-01

    Ion acoustic solitary waves and periodic waves in an unmagnetized plasma with superthermal (kappa-distributed) electrons and positrons are investigated through a non-perturbative approach. Model equations are transformed to a planar dynamical system. Then by using the bifurcations of phase portraits of this planar dynamical system, we have established that our model has solitary wave and periodic wave solutions. We have obtained two analytical solutions for these solitary and periodic waves depending on the parameters. From these solitary wave and periodic wave solutions, we have shown the combined effects of temperature ratio (σ) of electrons and positrons, spectral index (κ), speed of the traveling wave (v), and density ratio (p) of positrons and electrons on the characteristics of ion acoustic solitary and periodic waves. The spectral index, density ratio, speed of the traveling wave, and temperature ratio significantly affect the characteristics of ion acoustic solitary and periodic structures. The present study might be helpful to understand the salient features of nonlinear ion acoustic solitary and periodic structures in the interstellar medium.

  10. Optimization of hybrid antireflection structure integrating surface texturing and multi-layer interference coating

    Science.gov (United States)

    Kubota, Shigeru; Kanomata, Kensaku; Suzuki, Takahiko; Hirose, Fumihiko

    2014-10-01

    The antireflection structure (ARS) for solar cells is categorized to mainly two different techniques, i.e., the surface texturing and the single or multi-layer antireflection interference coating. In this study, we propose a novel hybrid ARS, which integrates moth eye texturing and multi-layer coat, for application to organic photovoltaics (OPVs). Using optical simulations based on the finite-difference time-domain (FDTD) method, we conduct nearly global optimization of the geometric parameters characterizing the hybrid ARS. The proposed optimization algorithm consists of two steps: in the first step, we optimize the period and height of moth eye array, in the absence of multi-layer coating. In the second step, we optimize the whole structure of hybrid ARS by using the solution obtained by the first step as the starting search point. The methods of the simple grid search and the Hooke and Jeeves pattern search are used for global and local searches, respectively. In addition, we study the effects of deviations in the geometric parameters of hybrid ARS from their optimized values. The design concept of hybrid ARS is highly beneficial for broadband light trapping in OPVs.

  11. On the generation of solitary waves observed by Cluster in the near-Earth magnetosheath

    Directory of Open Access Journals (Sweden)

    J. S. Pickett

    2005-01-01

    other waves and electrostatic fluctuations in this region making it impossible to isolate or clearly distinguish them from these other emissions in the waveform data. Based on these results, we have concluded that some of the near-Earth magnetosheath solitary waves, perhaps in the form of electron phase-space holes, may be generated locally by a two-stream instability involving electrons based on the counterstreaming electrons that are often observed when solitary waves are present. We have not ruled out the possibility that the solitary waves could be generated as a result of the lower-hybrid Buneman instability in the presence of an electron beam, through the electron acoustic mode or through processes involving turbulence, which is almost always present in the magnetosheath, but these will be examined in a more comprehensive study in the future.

  12. Plasmon-gating photoluminescence in graphene/GeSi quantum dots hybrid structures

    Science.gov (United States)

    Chen, Yulu; Wu, Qiong; Ma, Yingjie; Liu, Tao; Fan, Yongliang; Yang, Xinju; Zhong, Zhenyang; Xu, Fei; Lu, Jianping; Jiang, Zuimin

    2015-01-01

    The ability to control light-matter interaction is central to several potential applications in lasing, sensing, and communication. Graphene plasmons provide a way of strongly enhancing the interaction and realizing ultrathin optoelectronic devices. Here, we find that photoluminescence (PL) intensities of the graphene/GeSi quantum dots hybrid structures are saturated and quenched under positive and negative voltages at the excitation of 325 nm, respectively. A mechanism called plasmon-gating effect is proposed to reveal the PL dependence of the hybrid structures on the external electric field. On the contrary, the PL intensities at the excitation of 405 and 795 nm of the hybrid structures are quenched due to the charge transfer by tuning the Fermi level of graphene or the blocking of the excitons recombination by excitons separation effect. The results also provide an evidence for the charge transfer mechanism. The plasmon gating effect on the PL provides a new way to control the optical properties of graphene/QD hybrid structures. PMID:26631498

  13. Structure of hybrid organic-inorganic sols for the preparation of hydrothermally stable membranes

    NARCIS (Netherlands)

    Castricum, H.L.; Sah, A.; Geenevasen, J.A.J.; Kreiter, R.; Blank, D.H.A.; Vente, J.F.; ten Elshof, J.E.

    2008-01-01

    A procedure for the preparation of hybrid sols for the synthesis of organic-inorganic microporous materials and thin film membranes is reported. We describe silane reactivity and sol structure for acid-catalysed colloidal sols from mixtures of either tetraethylorthosilicate (TEOS) and methyltriethox

  14. Effect of concrete creep and shrinkage on tall hybrid structures and its countermeasures

    Institute of Scientific and Technical Information of China (English)

    Pusheng SHEN; Hui FANG; Xinhong XIA

    2009-01-01

    This paper aims to study the different vertical displacements in tall hybrid-structures and the corresponding engineering measures. First, the method to calculate the different vertical displacements in tall hybrid-structures is presented. This method takes into account the effects of construction process by applying loads sequentially story by story. Based on the concrete creep and shrinkage calculation formula in American Concrete Institute (ACI)code, with the assumption that loads are increased linearly in members, the creep and shrinkage effects of members are analyzed by adopting two parameters named average load-aged-coefficient and average age-last coefficient. The effects of steel ratio on members creep are analyzed by age-adjusted module method (AEMM). The effects that core-tube were constructed in advance to outer steel frame were also considered. Then, based on the samplecalculation, the measures to effectively reduce the different vertical displacements in hybrid-structures are proposed. This method is simple and practical in the calculation of different vertical displacements in tall and super-tall hybrid-structures.

  15. Probing Structure and Composition of Nickel/Titanium Carbide Hybrid Interfaces at the Atomic Scale (Preprint)

    Science.gov (United States)

    2010-01-01

    The transition in structure and composition across the titanium carbide /nickel hybrid interface has been determined at near atomic resolution by...coupling high-resolution transmission electron microscopy with three-dimensional atom probe tomography. The titanium carbide phase adopts a rocksalt-type

  16. Solitary magnetic perturbations at the ELM onset

    CERN Document Server

    Wenninger, RP; Boom, JE; Burckhart, A; Dunne, MG; Dux, R; Eich, T; Fischer, R; Fuchs, C; Garcia-Munoz, M; Igochine, V; Hoelzl, M; Luhmann, NC; Lunt, T; Maraschek, M; Mueller, HW; Park, HK; Schneider, PA; Sommer, F; Suttrop, W; Viezzer, E

    2012-01-01

    Edge localised modes (ELMs) allow maintaining sufficient purity of tokamak H-mode plasmas and thus enable stationary H-mode. On the other hand in a future device ELMs may cause divertor power flux densities far in excess of tolerable material limits. The size of the energy loss per ELM is determined by saturation effects in the non-linear phase of the ELM, which at present is hardly understood. Solitary magnetic perturbations (SMPs) are identified as dominant features in the radial magnetic fluctuations below 100kHz. They are typically observed close (+-0.1ms) to the onset of pedestal erosion. SMPs are field aligned structures rotating in the electron diamagnetic drift direction with perpendicular velocities of about 10km/s. A comparison of perpendicular velocities suggests that the perturbation evoking SMPs is located at or inside the separatrix. Analysis of very pronounced examples showed that the number of peaks per toroidal turn is 1 or 2, which is clearly lower than corresponding numbers in linear stabil...

  17. Solitary caecum diverticulitis mimicking acute appendicitis.

    Science.gov (United States)

    Hot, Semih; Eğin, Seracettin; Gökçek, Berk; Yeşiltaş, Metin; Alemdar, Ali; Akan, Arzu; Karahan, Servet Rüştü

    2015-12-01

    Solitary cecum diverticulum is a benign formation, but it can be complicated with inflammation, perforation and bleeding. Cecum diverticulitis (CD) is the most common complication of caecal diverticulum and it has the highest incidence among Asians, but it is a rare condition in the western world. The incidence of colonic diverticular disease can vary according to national origin, cultural structure and nutritional habits. CD is not common in our country, but it is an important situation because of its clinical similarity with the commonly seen acute right side abdominal diseases like acute appendicitis. Preoperative diagnosis is difficult, and hence, the actual frequency is not known. The treatment of CD can vary from medical therapy to right hemi colectomy. In this study, we presented ten CD cases on whom surgical resection was performed in our surgery unit during the last 8 years. Our purpose was to increase the awareness of surgeons about this situation, and so, make them pay attention for not having their first experience in the operating room.

  18. Stability and dispersion relations of three-dimensional solitary waves in trapped Bose-Einstein condensates

    Science.gov (United States)

    Muñoz Mateo, A.; Brand, J.

    2015-12-01

    We analyse the dynamical properties of three-dimensional solitary waves in cylindrically trapped Bose-Einstein condensates. Families of solitary waves bifurcate from the planar dark soliton and include the solitonic vortex, the vortex ring and more complex structures of intersecting vortex lines known collectively as Chladni solitons. The particle-like dynamics of these guided solitary waves provides potentially profitable features for their implementation in atomtronic circuits, and play a key role in the generation of metastable loop currents. Based on the time-dependent Gross-Pitaevskii equation we calculate the dispersion relations of moving solitary waves and their modes of dynamical instability. The dispersion relations reveal a complex crossing and bifurcation scenario. For stationary structures we find that for μ /{\\hslash }{ω }\\perp \\gt 2.65 the solitonic vortex is the only stable solitary wave. More complex Chladni solitons still have weaker instabilities than planar dark solitons and may be seen as transient structures in experiments. Fully time-dependent simulations illustrate typical decay scenarios, which may result in the generation of multiple separated solitonic vortices.

  19. Transient evolution of solitary electron holes in low pressure laboratory plasma

    CERN Document Server

    Choudhary, Mangilal; Mukherjee, Subroto

    2015-01-01

    Solitary electrons holes (SEHs) are localized electrostatic positive potential structures in collisionless plasmas. These are vortex-like structures in the electron phase space. Its existence is cause of distortion of the electron distribution in the resonant region. These are explained theoretically first time by Schamel et.al [Phys. Scr. 20, 336 (1979) and Phys. Plasmas 19, 020501 (2012)]. Propagating solitary electron holes can also be formed in a laboratory plasma when a fast rising high positive voltage pulse is applied to a metallic electrode [Kar et. al., Phys. Plasmas 17, 102113 (2010)] immersed in a low pressure plasma. The temporal evolution of these structures can be studied by measuring the transient electron distribution function (EDF). In the present work, transient EDF is measured after formation of a solitary electron hole in nearly uniform, unmagnetized, and collisionless plasma for applied pulse width and, where and are applied pulse width and inverse of ion plasma frequency respectively. Fo...

  20. Solitary waves in a self-gravitating opposite polarity dust-plasma medium

    Energy Technology Data Exchange (ETDEWEB)

    Mamun, A. A.; Schlickeiser, R. [Institut für Theoretische Physik, Lehrstuhl IV, Fakultät für Physik und Astronomie, Ruhr-Universität Bochum, D-44780 Bochum (Germany)

    2015-10-15

    A more general and realistic dusty plasma model, namely, self-gravitating opposite polarity dust-plasma system (containing inertial positive and negative dust, and inertialess ions and electrons following Maxwellian distribution) is considered. The possibility for the formation of solitary electrostatic and self-gravitational potential structures in such a dust-plasma system is thoroughly examined. The standard reductive perturbation method, which is valid for small but finite amplitude solitary structures, is employed. The parametric regimes for the existence of solitary electrostatic and self-gravitational potential structures, and their basic properties (viz., polarity, amplitude, width, and speed) are found to be significantly modified by the combined effects of positively charged dust component and self-gravitational field. The applications of the present investigation in different space dusty plasma environments and laboratory dusty plasma devices are briefly discussed.

  1. Hybrid FDTD Analysis for Periodic On-Chip Terahertz (THZ) Structures

    Energy Technology Data Exchange (ETDEWEB)

    Hussein, Yasser A.; Spencer, James E.; /SLAC

    2005-06-07

    We present electromagnetic analysis and radiation efficiency calculations for on-chip terahertz (THz) structures based on a hybrid, finite-difference, time-domain (HFDTD) technique. The method employs the FDTD technique to calculate S-parameters for one cell of a periodic structure. The transmission ABCD matrix is then estimated and multiplied by itself n times to obtain the n-cell periodic structure ABCD parameters that are then converted back to S-parameters. Validation of the method is carried out by comparing the results of the hybrid technique with FDTD calculations of the entire periodic structure as well as with HFSS which all agree quite well. This procedure reduces the CPU-time and allows efficient design and optimization of periodic THz radiation sources. Future research will involve coupling of Maxwell's equations with a more detailed, physics-based transport model for higher-order effects.

  2. Analysis of Non-Conventional Hybrid MOSFET Structure for Gate Leakage Current

    Directory of Open Access Journals (Sweden)

    RANA Ashwani K.

    2011-10-01

    Full Text Available A non-conventional hybrid MOSFET (HMOSstructure has been proposed to reduce the gate leakagecurrent. This non-conventional hybrid MOSFET consistsof source/drain-to-gate non-overlap region and high-kgate stack. The gate leakage behaviour of HMOS hasbeen investigated with the help of compact analyticalmodel, which is backed by Sentaurus Simulation. Ourmodel sustains a very good agreement between the modeland TCAD result. It is found that HMOS structure hasreduced the gate leakage current to great extent ascompared to conventional overlapped MOSFETstructure.

  3. A HYBRID GRANULARITY PARALLEL ALGORITHM FOR PRECISE INTEGRATION OF STRUCTURAL DYNAMIC RESPONSES

    Institute of Scientific and Technical Information of China (English)

    Yuanyin Li; Xianlong Jin; Genguo Li

    2008-01-01

    Precise integration methods to solve structural dynamic responses and the corre-sponding time integration formula are composed of two parts: the multiplication of an exponential matrix with a vector and the integration term. The second term can be solved by the series solu-tion. Two hybrid granularity parallel algorithms are designed, that is, the exponential matrix and the first term are computed by the fine-grained parallel algorithm and the second term is com-puted by the coarse-grained parallel algorithm. Numerical examples show that these two hybrid granularity parallel algorithms obtain higher speedup and parallel efficiency than two existing parallel algorithms.

  4. Rechargeable Mg battery cathode TiS3 with d-p orbital hybridized electronic structures

    Science.gov (United States)

    Taniguchi, Kouji; Gu, Yunpeng; Katsura, Yukari; Yoshino, Takafumi; Takagi, Hidenori

    2016-01-01

    Rechargeable performance is realized in Mg batteries using a TiS3 cathode without the nanometer-scale downsizing of electrode particles. The specific capacity is about 80 mAh/g for the first 50 cycles at room temperature. This observed specific capacity is comparable to that of the prototype cathode for Mg batteries. First-principles calculation indicates that TiS3 is a semiconductor with d-p orbital hybridized electronic structures around the Fermi level. The reversible electrode performance is likely assisted by the delocalized electronic distribution over metal-ligand units through d-p orbital hybridization.

  5. Enantioselective Catalysis by Using Short, Structurally Defined DNA Hairpins as Scaffold for Hybrid Catalysts.

    Science.gov (United States)

    Marek, Jasmin J; Singh, Raghvendra P; Heuer, Andreas; Hennecke, Ulrich

    2017-05-02

    A new type of DNA metal complex hybrid catalyst, which is based on single-stranded DNA oligonucleotides, is described. It was shown that oligonucleotides as short as 14 nucleotides that fold into hairpin structures are suitable as nucleic acid components for DNA hybrid catalysts. With these catalysts, excellent enantioinduction in asymmetric Diels-Alder reactions with selectivity values as high as 96 % enantiomeric excess (ee) can be achieved. Molecular dynamics simulations indicate that a rather flexible loop combined with a rigid stem region provides DNA scaffolds with these high selectivity values. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Preparation of Magnetic Hybrid Microspheres with Well-Defined Yolk-Shell Structure

    Directory of Open Access Journals (Sweden)

    Yuan Zhao

    2016-01-01

    Full Text Available A facile and efficient route was reported to prepare a kind of yolk-shell magnetic hybrid microspheres by suspension polymerization and calcinations method. The morphology, structure, and composition of the magnetic microspheres were characterized by FTIR, XRD, TEM, SEM, and TGA analysis. The vibrating-sample magnetometry (VSM results clearly showed that the magnetic particles were superparamagnetic with saturation magnetization of 32.82 emu/g which makes the microcomposites easily controlled by an external magnetic field. The results revealed that the magnetic hybrid microspheres might have important applications in magnetic bioseparation and drug delivery.

  7. Polarization dependence of the metamagnetic resonance of cut-wire-pair structure by using plasmon hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Dung, Nguyen Van; Yoo, Young Joon; Lee, Young Pak [Hanyang University, Seoul (Korea, Republic of); Tung, Nguyen Thanh [KU Leuven, Leuven (Belgium); Tung, Bui Son; Lam, Vu Dinh [Vietnam Academy of Science and Technology, Hanoi (Viet Nam)

    2014-07-15

    The influence of lattice constants on the electromagnetic behavior of a cut-wire-pair (CWP) structure has been elucidated. In this report, we performed both simulations and experiments to determine the influence of polarization on the metamagnetic resonance of the CWP structure. The key finding is the result of an investigation on the plasmon hybridization between the two CWs, which showed that the polarization of the incident wave was affected. Good agreement between numerical simulation and measurement is achieved.

  8. Improving hybrid statistical and physical forcefields through local structure enumeration.

    Science.gov (United States)

    Conway, Patrick; DiMaio, Frank

    2016-08-01

    Forcefields used in biomolecular simulations are comprised of energetic terms that are physical in nature, based on parameter fitting to quantum mechanical simulation or experimental data, or statistical, drawing off high-resolution structural data to describe distributions of molecular features. Combining the two in a single forcefield is challenging, since physical terms describe some, but not all, of the observed statistics, leading to double counting. In this manuscript, we develop a general scheme for correcting statistical potentials used in combination with physical terms. We apply these corrections to the sidechain torsional potential used in the Rosetta all-atom forcefield. We show the approach identifies instances of double-counted interactions, including electrostatic interactions between sidechain and nearby backbone, and steric interactions between neighboring Cβ atoms within secondary structural elements. Moreover, this scheme allows for the inclusion of intraresidue physical terms, previously turned off to avoid overlap with the statistical potential. Combined, these corrections lead to a forcefield with improved performance on several structure prediction tasks, including rotamer prediction and native structure discrimination.

  9. Enhanced hybrid search algorithm for protein structure prediction using the 3D-HP lattice model.

    Science.gov (United States)

    Zhou, Changjun; Hou, Caixia; Zhang, Qiang; Wei, Xiaopeng

    2013-09-01

    The problem of protein structure prediction in the hydrophobic-polar (HP) lattice model is the prediction of protein tertiary structure. This problem is usually referred to as the protein folding problem. This paper presents a method for the application of an enhanced hybrid search algorithm to the problem of protein folding prediction, using the three dimensional (3D) HP lattice model. The enhanced hybrid search algorithm is a combination of the particle swarm optimizer (PSO) and tabu search (TS) algorithms. Since the PSO algorithm entraps local minimum in later evolution extremely easily, we combined PSO with the TS algorithm, which has properties of global optimization. Since the technologies of crossover and mutation are applied many times to PSO and TS algorithms, so enhanced hybrid search algorithm is called the MCMPSO-TS (multiple crossover and mutation PSO-TS) algorithm. Experimental results show that the MCMPSO-TS algorithm can find the best solutions so far for the listed benchmarks, which will help comparison with any future paper approach. Moreover, real protein sequences and Fibonacci sequences are verified in the 3D HP lattice model for the first time. Compared with the previous evolutionary algorithms, the new hybrid search algorithm is novel, and can be used effectively to predict 3D protein folding structure. With continuous development and changes in amino acids sequences, the new algorithm will also make a contribution to the study of new protein sequences.

  10. Different proportions of C/KCu7S4 hybrid structure for high-performance supercapacitors

    Science.gov (United States)

    Dai, Shuge; Xi, Yi; Hu, Chenguo; Yue, Xule; Cheng, Lu; Wang, Guo

    2014-10-01

    KCu7S4 has the channel structure and minor resistance. Its double larger channels ensure that the ions can well exchange with other's, at the same time, can shorten the ionic diffusion path and improve the ionic and electronic transport. So KCu7S4 shows good electrochemical property. The paper reports a novel and high performance supercapacitor based on hybrid carbon particles and KCu7S4 (C/KCu7S4) electrode. For the hybrid structure with different proportions of C and KCu7S4, the C/KCu7S4 (1:10) hybrid supercapacitor shows preferable electrochemical performance and large specific capacitance (469 mF cm-2) at high charge-discharge rate (2 mA), still retaining ∼95% of the capacitance over 5000 cycles by charge-discharge process at a fixed current of 10 mA. Three supercapacitor units in series can light 50 light-emitting diodes (LEDs) for 2.5 min, 10 LEDs for 4 min, one LED for 5.5 min. The much-increased capacity, rate capability, and cycling stability may be attributed to the superionic conductive KCu7S4 nanowires and C/KCu7S4 hybrid structure, which improve ionic and electronic transport, enhance the kinetics of redox reactions through the electrode system.

  11. Impact Resistance of Lightweight Hybrid Structures for Gas Turbine Engine Fan Containment Applications

    Science.gov (United States)

    Hebsur, Mohan G.; Noebe, Ronald D.; Revilock, Duane M.

    2003-01-01

    The ballistic impact resistance of hybrid composite sandwich structures was evaluated with the ultimate goal of developing new materials or structures for potential gas turbine engine fan containment applications. The sandwich structures investigated consisted of GLARE-5 laminates as face sheets with lightweight cellular metallic materials such as honeycomb, foam, and lattice block as a core material. The impact resistance of these hybrid sandwich structures was compared to GLARE-5 laminates and 2024-T3 Al sheet, which were tested as a function of areal weight (material thickness). The GLARE-5 laminates exhibited comparable impact properties to that of 2024-T3 Al at low areal weights, even though there were significant differences in the static tensile properties of these materials. The GLARE-5, however, did have a greater ballistic limit than straight aluminum sheet at higher areal weights. Furthermore, there is up to a 25% advantage in ballistic limit for the GLARE-5/foam sandwich structures compared to straight 2024-T3 Al. But no advantage in ballistic limit was observed between any of the hybrid sandwich structures and thicker versions of GLARE-5. Recommendations for future work are provided, based on these preliminary data.

  12. Hybrid density functional study of the structural, bonding, and electronic properties of bismuth vanadate

    Science.gov (United States)

    Kweon, Kyoung E.; Hwang, Gyeong S.

    2012-10-01

    The structure and property prediction of metal oxides can significantly be improved by incorporating exact Hartree-Fock (HF) exchange into density functional theory (DFT), which is the so-called hybrid DFT. We explored the impact of HF exchange inclusion on the predicted structural, bonding, and electronic properties of bismuth vanadate (BiVO4), with particular attention to the difference between its monoclinic and tetragonal scheelite phases. The applied exchange-correlation (xc) functionals include the gradient corrected Perdew-Burke-Ernzerhof (PBE) and the PBE-HF hybrid functionals with HF exchange amounts of 10%, 25%, and 50%. We find that the PBE-HF25% yields a monoclinic structure in very close agreement with the experimentally determined structure, while the PBE-HF50% tends to overestimate the monoclinic distortion and the PBE/PBE-HF10% can hardly identify a distinct monoclinic configuration at ambient conditions. Electronic structure analysis reveals that the increasing monoclinic distortion with the amount of HF exchange is related to the enhancement of hybridization between Bi 6s-O 2p antibonding states and unoccupied Bi 6p states. The bonding mechanisms and band structures of the monoclinic and tetragonal phases of BiVO4 were also investigated, and we discuss how the predictions are sensitive to the xc functional choice.

  13. Colloidal solitary waves with temperature dependent compressibility

    Science.gov (United States)

    Azmi, A.; Marchant, T. R.

    2014-05-01

    Spatial solitary waves which form in colloidal suspensions of dielectric nanoparticles are considered. The interactions, or compressibility, of the colloidal particles, is modelled using a series in the particle density, or packing fraction, where the virial, or series, coefficients depend on the type of particle interaction model. Both the theoretical hard disk and sphere repulsive models, and a model with temperature dependent compressibility, are considered. Experimental results show that particle interactions can be temperature dependent and either repulsive or attractive in nature, so we model the second virial coefficient using a physically realistic temperature power law. One- and two-dimensional semi-analytical colloidal solitary wave solutions are found. Trial functions, based on the form of the nonlinear Schrödinger equation soliton, are used, together with averaging, to develop the semi-analytical solutions. When the background packing fraction is low, the one-dimensional solitary waves have three solutions branches (with a bistable regime) while the two-dimensional solitary waves have two solution branches, with a single stable branch. The temperature dependent second virial coefficient results in changes to the solitary wave properties and the parameter space, in which multiple solutions branches occur. An excellent comparison is found between the semi-analytical and numerical solutions.

  14. Adjustable solitary waves in electroactive rods

    Science.gov (United States)

    Wang, Y. Z.; Zhang, C. L.; Dai, H.-H.; Chen, W. Q.

    2015-10-01

    This paper presents an asymptotic analysis of solitary waves propagating in an incompressible isotropic electroactive circular rod subjected to a biasing longitudinal electric displacement. Several asymptotic expansions are introduced to simplify the rod governing equations. The boundary conditions on the lateral surface of the rod are satisfied from the asymptotic point of view. In the limit of finite-small amplitude and long wavelength, a set of ten simplified one-dimensional nonlinear governing equations is established. To validate our approach and the derivation, we compare the linear dispersion relation with the one directly derived from the three-dimensional linear theory in the limit of long wavelength. Then, by the reductive perturbation method, we deduce the far-field equation (i.e. the KdV equation). Finally, the leading order of the electroelastic solitary wave solution is presented. Numerical examples are provided to show the influences of the biasing electric displacement and material constants on the solitary waves. It is found that the biasing electric displacement can modulate the velocity of solitary waves with a prescribed amplitude in the electroactive rod, a very interesting result which may promote the particular application of solitary waves in solids with multi-field coupling.

  15. Solitary Spinal Epidural Metastasis from Gastric Cancer

    Directory of Open Access Journals (Sweden)

    Taisei Sako

    2016-01-01

    Full Text Available Solitary epidural space metastasis of a malignant tumor is rare. We encountered a 79-year-old male patient with solitary metastatic epidural tumor who developed paraplegia and dysuria. The patient had undergone total gastrectomy for gastric cancer followed by chemotherapy 8 months priorly. The whole body was examined for suspected metastatic spinal tumor, but no metastases of the spine or important organs were observed, and a solitary mass was present in the thoracic spinal epidural space. The mass was excised for diagnosis and treatment and was histopathologically diagnosed as metastasis from gastric cancer. No solitary metastatic epidural tumor from gastric cancer has been reported in English. Among the Japanese, 3 cases have been reported, in which the outcome was poor in all cases and no definite diagnosis could be made before surgery in any case. Our patient developed concomitant pneumonia after surgery and died shortly after the surgery. When a patient has a past medical history of malignant tumor, the possibility of a solitary metastatic tumor in the epidural space should be considered.

  16. Proton Conduction in Sulfonated Organic-Inorganic Hybrid Monoliths with Hierarchical Pore Structure.

    Science.gov (United States)

    von der Lehr, Martin; Seidler, Christopher F; Taffa, Dereje H; Wark, Michael; Smarsly, Bernd M; Marschall, Roland

    2016-09-28

    Porous organic-inorganic hybrid monoliths with hierarchical porosity exhibiting macro- and mesopores are prepared via sol-gel process under variation of the mesopore size. Organic moieties in the pore walls are incorporated by substituting up to 10% of the silicon precursor tetramethylorthosilicate with bisilylated benzene molecules. After functionalization with sulfonic acid groups, the resulting sulfonated hybrid monoliths featuring a bimodal pore structure are investigated regarding proton conduction depending on temperature and relative humidity. The hierarchical pore system and controlled mesopore design turn out to be crucial for sulfonation and proton conduction. These sulfonated hybrid hierarchical monoliths containing only 10% organic precursor exhibit higher proton conduction at different relative humidities than sulfonated periodic mesoporous organosilica made of 100% bisilylated precursors exhibiting solely mesopores, even with a lower concentration of sulfonic acid groups.

  17. SYNTHESIS AND CHARACTERIZATION OF STRUCTURALLY WELL-DEFINED POLYMER-INORGANIC HYBRID NANOPARTICLES VIA ATRP

    Institute of Scientific and Technical Information of China (English)

    Jie Bai; Jie-bin Pang; Kun-yuan Qiu; Yen Wei

    2002-01-01

    Atom transfer radical polymerization (ATRP) using cuprous chloride/2,2'-bipyridine (bipy) was applied to graft polymerization of styrene on the surface of silica nanoparticles to synthesize polymer-inorganic hybrid nanoparticles. 2-(4-Chloromethylphenyl) ethyltriethoxysilane (CTES) was immobilized on the surface of silica nanoparticles through condensation reaction of the silanol groups on silica with triethoxysilane group of CTES. Then ATRP of St was initiated by this surface-modified silica nanoparticles bearing benzyl chloride groups, and formed PSt graft chains on the surface of silica nanoparticles. The thickness of the graft chains increased with reaction time. End group analysis confirmed the occurrence of ATRP. Thermal analysis indicated that thermal stabilization of these resulting hybrid nanoparticles also increases with polymerization conversion. The results above show that this "grafting from" reaction could be used for the preparation of polymer-inorganic hybrid nanoparticles with controlled structure of the polymer's end groups.

  18. Electronic Structure Rearrangements in Hybrid Ribozyme/Protein Catalysis

    Science.gov (United States)

    Kang, Jiyoung; Kino, Hiori; Field, Martin J.; Tateno, Masaru

    2017-04-01

    We analyzed the electronic structural changes that occur in the reaction cycle of a biological catalyst composed of RNA and protein, and elucidated the dynamical rearrangements of the electronic structure that was obtained from our previous study in which ab initio quantum mechanics/molecular mechanics molecular dynamics simulations were performed. Notable results that we obtained include the generation of a reactive HOMO that is responsible for bond formation in the initial stages of the reaction, and the appearance of a reactive LUMO that is involved in the bond rupture that leads to products. We denote these changes as dynamical induction of the reactive HOMO (DIRH) and LUMO (DIRL), respectively. Interestingly, we also find that the induction of the reactive HOMO is enhanced by the formation of a low-barrier hydrogen bond (LBHB), which, to the best of our knowledge, represents a novel role for LBHBs in enzymatic systems.

  19. Enhanced Structural, Thermal, and Electrical Properties of Multiwalled Carbon Nanotubes Hybridized with Silver Nanoparticles

    Directory of Open Access Journals (Sweden)

    Yusliza Yusof

    2016-01-01

    Full Text Available The objective of this study is to evaluate the structural, thermal, and electrical properties of multiwalled carbon nanotubes (MWNT hybridized with silver nanoparticles (AgNP obtained via chemical reduction of aqueous silver salt assisted with sodium dodecyl sulphate (SDS as stabilizing agent. Transmission electron microscopy (TEM reveals microstructural analysis of the MWNT-Ag hybrids. The Fourier transform infrared (FTIR spectra prove the interactions between the AgNP and carboxyl groups of the MWNT. Raman spectra reveal that the D- to G-band intensity ratios ID/IG and ID′/IG increase upon the deposition of AgNP onto the surface of the MWNT. Thermogravimetric analysis (TGA shows that the MWNT-Ag hybrids decompose at a much faster rate and the weight loss decreased considerably due to the presence of AgNP. Nonlinearity of current-voltage (I-V curves indicates that electrical transport of pristine MWNT is enhanced when AgNP is induced as charge carriers in the MWNT-Ag hybrids. The threshold voltage Vth value for the MWNT doped with a maximum of 70 vol% of AgNP was substantially reduced by 65% relative to the pristine MWNT. The MWNT-Ag hybrids have a favourable electrical characteristic with a low threshold voltage that shows enhancement mode for field-effect transistor (FET applications.

  20. Structural Organization of Enzymes of the Phenylacetate Catabolic Hybrid Pathway

    OpenAIRE

    Grishin, Andrey M.; Miroslaw Cygler

    2015-01-01

    Aromatic compounds are the second most abundant class of molecules on the earth and frequent environmental pollutants. They are difficult to metabolize due to an inert chemical structure, and of all living organisms, only microbes have evolved biochemical pathways that can open an aromatic ring and catabolize thus formed organic molecules. In bacterial genomes, the phenylacetate (PA) utilization pathway is abundant and represents the central route for degradation of a variety of organic compo...

  1. Alfven solitary waves in nonrelativistic, relativistic, and ultra-relativistic degenerate quantum plasma

    Energy Technology Data Exchange (ETDEWEB)

    Rehman, M. A.; Qureshi, M. N. S. [Department of Physics, GC University, Kachery Road, Lahore 54000 (Pakistan); Shah, H. A. [Department of Physics, Forman Christian College, Ferozepur Road, Lahore 54600 (Pakistan); Masood, W. [COMSATS, Institute of Information Technology, Park Road, Chak Shehzad, Islamabad 44000 (Pakistan); National Centre for Physics (NCP) Shahdra Valley Road, Islamabad (Pakistan)

    2015-10-15

    Nonlinear circularly polarized Alfvén waves are studied in magnetized nonrelativistic, relativistic, and ultrarelativistic degenerate Fermi plasmas. Using the quantum hydrodynamic model, Zakharov equations are derived and the Sagdeev potential approach is used to investigate the properties of the electromagnetic solitary structures. It is seen that the amplitude increases with the increase of electron density in the relativistic and ultrarelativistic cases but decreases in the nonrelativistic case. Both right and left handed waves are considered, and it is seen that supersonic, subsonic, and super- and sub-Alfvénic solitary structures are obtained for different polarizations and under different relativistic regimes.

  2. Electron-acoustic solitary waves in a beam plasma with electron trapping and nonextensivity effects

    Science.gov (United States)

    Ali Shan, S.; Aman-ur-Rehman, Mushtaq, A.

    2016-09-01

    A theoretical investigation is carried out for understanding the properties of electron-acoustic solitary waves (EASWs) in a beam plasma whose constituents are a cold beam electron fluid, hot nonextensive electrons obeying a vortex-like distribution with nonextensive factor q, and stationary ions. An energy integral (Schamel KdV) equation is derived by employing pseudo-potential (reductive perturbation) approach. The presence of nonextensive q-distributed hot trapped electrons and cold electron beam has been shown to influence the soliton structure quite significantly. The nonlinear dispersion relation is derived to analyze the dependency of the electron acoustic solitary wave quantities. From the analysis of our results, it is shown that the present plasma model supports the compressive EASWs. As the real plasma situations are observed with plasma species having a relative flow, so our present analysis should be useful for understanding the electrostatic solitary structures observed in the dayside auroral zone and other regions of the magnetosphere.

  3. Screened exchange hybrid density functional for accurate and efficient structures and interaction energies.

    Science.gov (United States)

    Brandenburg, Jan Gerit; Caldeweyher, Eike; Grimme, Stefan

    2016-06-21

    We extend the recently introduced PBEh-3c global hybrid density functional [S. Grimme et al., J. Chem. Phys., 2015, 143, 054107] by a screened Fock exchange variant based on the Henderson-Janesko-Scuseria exchange hole model. While the excellent performance of the global hybrid is maintained for small covalently bound molecules, its performance for computed condensed phase mass densities is further improved. Most importantly, a speed up of 30 to 50% can be achieved and especially for small orbital energy gap cases, the method is numerically much more robust. The latter point is important for many applications, e.g., for metal-organic frameworks, organic semiconductors, or protein structures. This enables an accurate density functional based electronic structure calculation of a full DNA helix structure on a single core desktop computer which is presented as an example in addition to comprehensive benchmark results.

  4. Chlorine adlayer-templated growth of a hybrid inorganic-organic layered structure on Au(111)

    Science.gov (United States)

    Rzeźnicka, I. I.; Horino, H.; Yagyu, K.; Suzuki, T.; Kajimoto, S.; Fukumura, H.

    2016-10-01

    Growth of a hybrid inorganic-organic layered structure on the Au(111) surface using a one-step solution growth is reported. The hybrid structure is consist of 4,4‧-bipyridine [4,4‧-BiPyH2]2 + cations, Cl anions and Au adatoms, provided from substrate by means of the adsorbate-induced surface phase transition of a surface reconstruction. Its surface and bulk structures were characterized by scanning tunneling microscopy (STM), secondary ion mass spectrometry (SIMS), and Raman spectroscopy. STM results reveal growth of the first [4,4‧-BiPyH2]2 + layer on top of the p(√{ 3} ×√{ 3})" separators=", R 30 ° chlorine overlayer formed on the Au(111) surface. These two layers are found to provide a platform for a following three-dimensional growth facilitated by hydrogen bonding, aurophilic and π-π stacking interactions.

  5. Quasi-Static Single-Component Hybrid Simulation of a Composite Structure with Multi-Axis Control

    DEFF Research Database (Denmark)

    Høgh, J.; Waldbjørn, J.; Wittrup-Schmidt, J.

    2015-01-01

    This paper presents a quasi-static hybrid simulation performed on a single component structure. Hybrid simulation is a substructural technique, where a structure is divided into two sections: a numerical section of the main structure and a physical experiment of the remainder. In previous cases...... to evaluate the validity of the method, the results are compared to a test of the emulated structure – referred to here as the reference test. It was found that the error introduced by compliance in the load train was significant. Digital image correlation was for this reason implemented in the hybrid...

  6. Hybrid Direct Write Lithographic Strategies for Complex Hierarchical Structures

    Science.gov (United States)

    Singer, Jonathan P.

    With the number of alternative lithographic techniques for high resolution and 3D patterning rapidly increasing, there is a need to identify a set of scalable techniques which balances the ability to arbitrarily control every detail of a target pattern and to produce these complex patterns at a high rate. It is in this way that metamaterial devices put forward on a lab scale for applications such as phononics, photonics, and plasmonics can be realized in the industrial scale. This thesis, in approaching this challenge, utilizes combinations of patterning techniques, leveraging the ability for "large" scale alternative lithographic techniques, such as interference lithography or self-assembly, to create the same nanostructured morphology over a large area combined with laser direct write. The process of drawing a single line or isolated voxel can result in a hierarchical pattern defined by the latent motif of the larger-scale technique. The net resuh is to shift the burden of high resolution patterning from the direct write to the large scale technique, effectively decoupling the correlation between the level of detail and the patterning speed and control. More specifically, the following combinations with laser direct writing were investigated: (1) proximity field nanopatterning for the predefinition of diffraction-order-defined 3D resonators which were applied as "stand-up" plasmodic microresonators, (2) dewetting to conduct development-free 2D patterning of isolated sub-micron lines, and, via overlap effects, nanoscale ( <1 00 nm) gratings, (3) block copolymer self-assembly to initiate the simultaneous annealing and alignment of near-equilibrium microdomains from a metastable starting morphology, and (4) interference lithography to fabricate 3D sub-micron periodic and quasiperiodic hierarchical structures with controllable positioning and tunable fill fraction that has potential for applications to microphotonics. In conjunction with the experimental components

  7. Dynamic Behavior of Hybrid APM (Advanced Pore Morphology Foam and Aluminum Foam Filled Structures

    Directory of Open Access Journals (Sweden)

    Joerg Weise

    2012-06-01

    Full Text Available The aim of this work is to evaluate the effect of different densities of hybrid aluminum polymer foam on the frequency behavior of a foam filled steel structure with different ratios between steel and foam masses. The foam filled structure is composed of three steel tubes with a welded flange at both ends bolted together to form a portal grounded by its free ends. Structure, internal and ground constraints have been designed and manufactured in order to minimize nonlinear effects and to guarantee optimal constraint conditions. Mode shapes and frequencies were verified with finite elements models (FEM to be in the range of experimental modal analysis, considering the frequency measurement range limits for instrumented hammer and accelerometer. Selected modes have been identified with suitable modal parameters extraction techniques. Each structure has been tested before and after filling, in order to compute the percentage variation of modal parameters. Two different densities of hybrid aluminum polymer foam have been tested and compared with structures filled with aluminum foams produced using the powder compact melting technique. All the foam fillings were able to suppress high frequency membrane modes which results in a reduction of environmental noise and an increase in performance of the components. Low frequency modes show an increase in damping ratio only when small thickness steel frames are filled with either Hybrid APM or Alulight foam.

  8. Intraoral solitary neurofibroma in an infant

    Directory of Open Access Journals (Sweden)

    Narwal Anjali

    2008-01-01

    Full Text Available Neurofibroma is a non-circumscribed, thick and irregular benign tumor of the peripheral nerve sheath. On the skin, the diffuse and soft nature of neurofibroma often resembles "a bag of worms". It can develop at any point along a nerve and often form by late adolescence. Although neurofibromas occur predominantly as a feature of neurofibromatosis affecting the soft tissue, a few cases of solitary intraoral neurofibromas have also been reported. Solitary intraosseous neurofibroma in the oral cavity is a rare benign tumor with very few cases reported in literature. This case report presents a case of intraosseous solitary neurofibroma of maxilla in a 5-month-old male child due to the rarity of this tumor at this site in very early age, along with a discussion of its clinical, radiological, and histopathological presentation.

  9. Hierarchical structuring of liquid crystal polymer-Laponite hybrid materials.

    Science.gov (United States)

    Tritschler, Ulrich; Zlotnikov, Igor; Zaslansky, Paul; Aichmayer, Barbara; Fratzl, Peter; Schlaad, Helmut; Cölfen, Helmut

    2013-09-03

    Biomimetic organic-inorganic composite materials were fabricated via one-step self-organization on three hierarchical levels. The organic component was a polyoxazoline with pendent cholesteryl and carboxyl (N-Boc-protected amino acid) side chains that was able to form a chiral nematic lyotropic phase and bind to positively charged inorganic faces of Laponite. The Laponite particles formed a mesocrystalline arrangement within the liquid-crystal (LC) polymer phase upon shearing a viscous dispersion of Laponite nanoparticles and LC polymer in DMF. Complementary analytical and mechanical characterization techniques (AUC, POM, TEM, SEM, SAXS, μCT, and nanoindentation) covering the millimeter, micrometer, and nanometer length scales reveal the hierarchical structures and properties of the composite materials consisting of different ratios of Laponite nanoparticles and liquid-crystalline polymer.

  10. Subgap transport in silicene-based superconducting hybrid structures

    Science.gov (United States)

    Li, Hai

    2016-08-01

    We investigate the influences of exchange field and perpendicular electric field on the subgap transport in silicene-based ferromagnetic/superconducting (FS) and ferromagnetic/superconducting/ferromagnetic (FSF) junctions. Owing to the unique buckling structure of silicene, the Andreev reflection and subgap conductance can be effectively modulated by a perpendicular electric field. It is revealed that the subgap conductance in the FS junction can be distinctly enhanced by an exchange field. Remarkably, resorting to the tunable band gap of silicene, an exclusive crossed Andreev reflection (CAR) process in the FSF junction can be realized within a wide range of related parameters. Moreover, in the FSF junction the exclusive CAR and exclusive elastic cotunneling processes can be switched by reversing the magnetization direction in one of the ferromagnetic regions.

  11. A radiographic study of solitary bone cysts

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Rak; Hwang, Eui Hwan; Lee, Sang Rae [Dept. of Oral and Maxillofacial Radiology, Division of Dentistry, Kyung Hee University, Seoul (Korea, Republic of)

    1994-02-15

    The aim of this study was to evaluate the clinical, radiographic and histopathologic features of 23 cases of solitary bone cyst by means of the analysis of radiographs and biopsy specimens in 23 persons visited the Department of Oral and Maxillofacial Radiology, School of Dentistry, Kyung Hee University and Chunbuk National University. The obtained results were as follows; 1. The incidence of solitary bone cyst was almost equal in males (52.2%) and in females(42.8%) and the prevalent age of the solitary bone cyst were the second decade (47.8%) and the third decade (21.7%). 2. In the signs and symptoms of solitary bone cyst, pain or tenderness revealed in 17.4%, swelling revealed in 13.0%, pain and swelling revealed in 21.7%, paresthesia revealed in 4.4% and 43.5% were a symptom and the tooth vitality involved in the solitary bone cyst, 76.5% were posterior and 23.5% were either positive or negative. 3. In the location of the solitary bone cyst, 47.8% present posterior region, 21.7% present anterior region, 21.6% present anterior and posterior region, 4.4% present condylar process area. 4. In the hyperostotic border of the solitary bone cyst, 47.8% were seen entirely, 21.8% were seen partially, and 30.4% were not seen. 5. In the change of tooth, 59.1% were loss of the alveolar lamina dura, 13.6% were root resorption 4.55% were tooth displacement, 4.55% were root resorption and tooth displacement. 6. In the change of cortical bone of the solitary bone cyst, 39.1% were intact and 60.9% were thinning and expansion of cortical bone. 7. In the histopathologic findings of 9 cases, 33.3% were thin connective tissue wall, 11.1% were thickened myxo-fibromatous wall, 55.6% were thickened myxofibromatous wall with dysplastic bone formation.

  12. Uphill solitary waves in granular flows

    Science.gov (United States)

    Martínez, E.; Pérez-Penichet, C.; Sotolongo-Costa, O.; Ramos, O.; Måløy, K. J.; Douady, S.; Altshuler, E.

    2007-03-01

    We have experimentally observed uphill solitary waves in the surface flow on a granular material. A heap is constructed by injecting sand between two vertical glass plates separated by a distance much larger than the average grain size, with an open boundary. As the heap reaches the open boundary, solitary fluctuations appear on the flowing layer and move “up the hill” (i.e., against the direction of the flow). We explain the phenomenon in the context of stop-and-go traffic models.

  13. Domain-dependent electronic structure and optical absorption property in hybrid organic-inorganic perovskite.

    Science.gov (United States)

    Meng, Xiang; Zhang, Ruifeng; Fu, Zhongheng; Zhang, Qianfan

    2016-10-05

    Hybrid organic-inorganic perovskites, represented by materials in the CH3NH3PbI3 series, have become one of the most promising materials for solar cells with a high power conversion efficiency and low cost. The ordered Pb-I cage in such hybrid perovskites can induce the polarized cations to form a variety of polarization domains with long-range order, which will lead to the formation of specific atomic conformations or metastable crystalline phases, unique electronic band structures and optical absorption properties. Such domain-dependent characteristics play a critical role in the phase transition and service stability of such solar cells, and also open up the opportunity of tuning their electronic structure. In the present study, we systematically investigate the band structures and optical absorption properties of different electronically ordered domains in CH3NH3PbI3. By comparing different perovskites containing various cations, we have clarified the important influence of cation polarization on domain-dependent properties. Our results provide not only a possible pathway for the manipulation of band structure by applying an external field, but also a novel scheme for improving the performance and stability of hybrid perovskites.

  14. Carbon and metal nanotube hybrid structures on graphene as efficient electron field emitters

    Science.gov (United States)

    Heo, Kwang; Lee, Byung Yang; Lee, Hyungwoo; Cho, Dong-guk; Arif, Muhammad; Kim, Kyu Young; Choi, Young Jin; Hong, Seunghun

    2016-07-01

    We report a facile and efficient method for the fabrication of highly-flexible field emission devices by forming tubular hybrid structures based on carbon nanotubes (CNTs) and nickel nanotubes (Ni NTs) on graphene-based flexible substrates. By employing an infiltration process in anodic alumina oxide (AAO) templates followed by Ni electrodeposition, we could fabricate CNT-wrapped Ni NT/graphene hybrid structures. During the electrodeposition process, the CNTs served as Ni nucleation sites, resulting in a large-area array of high aspect-ratio field emitters composed of CNT-wrapped Ni NT hybrid structures. As a proof of concepts, we demonstrate that high-quality flexible field emission devices can be simply fabricated using our method. Remarkably, our proto-type field emission devices exhibited a current density higher by two orders of magnitude compared to other devices fabricated by previous methods, while maintaining its structural integrity in various bending deformations. This novel fabrication strategy can be utilized in various applications such as optoelectronic devices, sensors and energy storage devices.

  15. Genetic Segregation and Genomic Hybridization Patterns Support an Allotetraploid Structure and Disomic Inheritance for Salix Species

    Directory of Open Access Journals (Sweden)

    Gianni Barcaccia

    2014-09-01

    Full Text Available The Salix alba L. (white willow—Salix fragilis L. (crack willow complex includes closely related polyploid species, mainly tetraploid (2n = 4x = 76, which are dioecious and hence obligate allogamous. Because little is known about the genome constitution and chromosome behavior of these pure willow trees, genetic analysis of their naturally occurring interspecific polyploid hybrids is still very difficult. A two-way pseudo-testcross strategy was exploited using single-dose AFLP markers in order to assess the main inheritance patterns of tetraploid biotypes (disomy vs. tetrasomy in segregating populations stemmed from S. alba × S. fragilis crosses and reciprocals. In addition, a genomic in situ hybridization (GISH technology was implemented in willow to shed some light on the genome structure of S. alba and S. fragilis species, and their hybrids (allopolyploidy vs. autopolyploidy. The frequency of S. alba-specific molecular markers was almost double compared to that of S. fragilis-specific ones, suggesting the phylogenetic hypothesis of S. fragilis as derivative species from S. alba-like progenitors. Cytogenetic observations at pro-metaphase revealed about half of the chromosome complements being less contracted than the remaining ones, supporting an allopolyploid origin of both S. alba and S. fragilis. Both genetic segregation and genomic hybridization data are consistent with an allotetraploid nature of the Salix species. In particular, the vast majority of the AFLP markers were inherited according to disomic patterns in S. alba × S. fragilis populations and reciprocals. Moreover, in all S. alba against S. fragilis hybridizations and reciprocals, GISH signals were observed only on the contracted chromosomes whereas the non-contracted chromosomes were never hybridized. In conclusion, half of the chromosomes of the pure species S. alba and S. fragilis are closely related and they could share a common diploid ancestor, while the rest of

  16. Glassy Carbon Coating Deposited on Hybrid Structure of Composite Materials

    Directory of Open Access Journals (Sweden)

    Posmyk A.

    2016-06-01

    Full Text Available This paper presents a method of production metal matrix composites with aluminum oxide foam covered by glassy carbon layer used as reinforcement. The glassy carbon coating was formed for decreasing of friction coefficient and reducing the wear. In first step of technology liquid glassy carbon precursor is on ceramic foam deposited, subsequently cured and carbonated at elevated temperature. In this way ceramic foam is covered with glassy carbon coating with thickness of 2-8 μm. It provides desirable amount of glassy carbon in the structure of the material. In the next step, porous spheres with carbon coating are infiltrated by liquid matrix of Al-Cu-Mg alloy. Thereby, equable distribution of glassy carbon in composite volume is achieved. Moreover, typical problems for composites reinforced by particles like sedimentation, agglomeration and clustering of particles are avoided. Tribological characteristics during friction in air versus cast iron as a counterpart were made. Produced composites with glassy carbon layer are characterised by friction coefficient between 0.08-0.20, thus meeting the typical conditions for solid lubricants.

  17. sp3-hybridized framework structure of group-14 elements discovered by genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Manh Cuong [Ames Laboratory; Zhao, Xin [Ames Laboratory; Wang, Cai-Zhuang [Ames Laboratory; Ho, Kai-Ming [Ames Laboratory

    2014-05-01

    Group-14 elements, including C, Si, Ge, and Sn, can form various stable and metastable structures. Finding new metastable structures of group-14 elements with desirable physical properties for new technological applications has attracted a lot of interest. Using a genetic algorithm, we discovered a new low-energy metastable distorted sp3-hybridized framework structure of the group-14 elements. It has P42/mnm symmetry with 12 atoms per unit cell. The void volume of this structure is as large as 139.7Å3 for Si P42/mnm, and it can be used for gas or metal-atom encapsulation. Band-structure calculations show that P42/mnm structures of Si and Ge are semiconducting with energy band gaps close to the optimal values for optoelectronic or photovoltaic applications. With metal-atom encapsulation, the P42/mnm structure would also be a candidate for rattling-mediated superconducting or used as thermoelectric materials.

  18. Hybrid Aluminum and Natural Fiber Composite Structure for Crash Safety Improvement

    Science.gov (United States)

    Helaili, S.; Chafra, M.; Chevalier, Y.

    There is a growing interest on pedestrian's protection in automotive safety standards. Pedestrians head impact is one of the most important tests. In this paper, a hybrid composite structure made from natural fiber and aluminum, which improve the head protection when impact is taken place, is presented. The structure is made from a honeycomb composite made from unidirectional and woven composites and a thin aluminum layer. A head impact model is developed. The number of hexagonal layers is fixed and the thickness of the aluminum layer of the honeycomb structure is varied. The specific absorption energy is then calculated.

  19. Development of Control Structure for Hybrid Wind Generators with Active Power Capability

    Directory of Open Access Journals (Sweden)

    Mehdi Niroomand

    2014-01-01

    Full Text Available A hierarchical control structure is proposed for hybrid energy systems (HES which consist of wind energy system (WES and energy storage system (ESS. The proposed multilevel control structure consists of four blocks: reference generation and mode select, power balancing, control algorithms, and switching control blocks. A high performance power management strategy is used for the system. Also, the proposed system is analyzed as an active power filter (APF with ability to control the voltage, to compensate the harmonics, and to deliver active power. The HES is designed with parallel DC coupled structure. Simulation results are shown for verification of the theoretical analysis.

  20. From bell-shaped solitary wave to W/M-shaped solitary wave solutions in an integrable nonlinear wave equation

    Indian Academy of Sciences (India)

    Aiyong Chen; Jibin Li; Chunhai Li; Yuanduo Zhang

    2010-01-01

    The bifurcation theory of dynamical systems is applied to an integrable non-linear wave equation. As a result, it is pointed out that the solitary waves of this equation evolve from bell-shaped solitary waves to W/M-shaped solitary waves when wave speed passes certain critical wave speed. Under different parameter conditions, all exact explicit parametric representations of solitary wave solutions are obtained.

  1. Eady Solitary Waves: A Theory of Type B Cyclogenesis.

    Science.gov (United States)

    Mitsudera, Humio

    1994-11-01

    Localized baroclinic instability in a weakly nonlinear, long-wave limit using an Eady model is studied. The resulting evolution equations have a form of the KdV type, including extra terms representing linear coupling. Baroclinic instability is triggered locally by the collision between two neutral solitary waves (one trapped at the upper boundary and the other at the lower boundary) if their incident amplitudes are sufficiently large. This characteristic is explained from the viewpoint of resonance when the relative phase speed, which depends on the amplitudes, is less than a critical value. The upper and lower disturbances grow in a coupled manner (resembling a normal-mode structure) initially, but they reverse direction slowly as the amplitudes increase, and eventually separate from each other.The motivation of this study is to investigate a type of extratropical cyclogenesis that involves a preexisting upper trough (termed as Type B development) from the viewpoint of resonant solitary waves. Two cases are of particular interest. First, the author examines a case where an upper disturbance preexists over an undisturbed low-level waveguide. The solitary waves exhibit behavior similar to that conceived by Hoskins et al. for Type B development; the lower disturbance is forced one sidedly by a preexisting upper disturbance initially, but in turn forces the latter once the former attains a sufficient amplitude, thus resulting in mutual reinforcement. Second, if a weak perturbation exists at the surface ahead of the preexisting strong upper disturbance, baroclinic instability is triggered when the two waves interact. Even though the amplitude of the lower disturbance is initially much weaker, it is intensified quickly and catches up with the amplitude of the upper disturbance, so that the coupled vertical structure resembles that of an unstable normal mode eventually. These results describe the observed behavior in Type B atmospheric cyclogenesis quite well.

  2. A hybrid analysis method for linear dynamic soil-structure interaction in time and frequency domain

    Institute of Scientific and Technical Information of China (English)

    丁海平; 廖振鹏

    2001-01-01

    A hybrid analysis method in time and frequency domains for linear soil-structure interaction is presented. First, the time domain solution of the system with Rayleigh damping excited by a short time impulse is obtained by the decoupling numerical simulation technique of near-field wave motion. Then, the corresponding frequency domain solution can be got by Fourier transform. According to the relationship between damping value and dynamic re-sponse of a system, the solution of the system with complex damping can be got by Taylor expansion. The hybrid method makes the best of decoupling and explicit algorithm in time domain, and increases the calculation efficien-cy for linear soil-structure interaction analysis.

  3. Tensile force identification in cable-stayed structures: Hybrid system identification algorithm and experimental verification

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Myung Hyun [POSCO, Incheon (Korea, Republic of); Hu, Jong Wan [Incheon National University, Incheon (Korea, Republic of)

    2014-11-15

    In this study, we investigate a method to detect tensile forces in cable-stayed structures using the combined sensitivity updating method and the advanced hybrid microgenetic algorithm. The proposed method allows us not only to avoid the trap of minimum at initial searching stage but also to find their final solutions in better numerical efficiency. The validity of the technique is numerically verified using a set of dynamic data obtained from a simulation of the cable model modeled using the finite element method. Then, the hybrid algorithm is applied to vibrating sagged cables in the laboratory scale test. The results obtained are in good agreement with the semi-analytical solutions and experimental results reported by other investigators. The results indicate that the new method is computationally efficient in characterizing the tensile force variation for cable-stayed structures.

  4. Manipulating hybrid structures of polymer/a-Si for thin film solar cells

    Science.gov (United States)

    Peng, Ying; He, Zhiqun; Diyaf, Adel; Ivaturi, Aruna; Zhang, Zhi; Liang, Chunjun; Wilson, John I. B.

    2014-03-01

    A series of uniform polymer/amorphous silicon hybrid structures have been fabricated by means of solution-casting for polymer and radio frequency excited plasma enhanced chemical vapour deposition for amorphous silicon (a-Si:H). Poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) functioned as a photoactive donor, while the silicon layer acted as an acceptor. It is found that matching the hole mobility of the polymer to the electron mobility of amorphous silicon is critical to improve the photovoltaic performance from hybrid cells. A three-layer p-i-n structure of ITO/PEDOT:PSS(200 nm)/i-Si(450 nm)/n-Si(200 nm)/Al with a power conversion efficiency of 4.78% under a standard test condition was achieved.

  5. Manipulating hybrid structures of polymer/a-Si for thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Ying; He, Zhiqun, E-mail: zhqhe@bjtu.edu.cn, E-mail: J.I.B.Wilson@hw.ac.uk; Zhang, Zhi; Liang, Chunjun [Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China); Diyaf, Adel; Ivaturi, Aruna; Wilson, John I. B., E-mail: zhqhe@bjtu.edu.cn, E-mail: J.I.B.Wilson@hw.ac.uk [SUPA, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)

    2014-03-10

    A series of uniform polymer/amorphous silicon hybrid structures have been fabricated by means of solution-casting for polymer and radio frequency excited plasma enhanced chemical vapour deposition for amorphous silicon (a-Si:H). Poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) functioned as a photoactive donor, while the silicon layer acted as an acceptor. It is found that matching the hole mobility of the polymer to the electron mobility of amorphous silicon is critical to improve the photovoltaic performance from hybrid cells. A three-layer p-i-n structure of ITO/PEDOT:PSS(200 nm)/i-Si(450 nm)/n-Si(200 nm)/Al with a power conversion efficiency of 4.78% under a standard test condition was achieved.

  6. Effect of Different Structural Materials on Neutronic Performance of a Hybrid Reactor

    Science.gov (United States)

    Übeyli, Mustafa; Tel, Eyyüp

    2003-06-01

    Selection of structural material for a fusion-fission (hybrid) reactor is very important by taking into account of neutronic performance of the blanket. Refractory metals and alloys have much higher operating temperatures and neutron wall load (NWL) capabilities than low activation materials (ferritic/martensitic steels, vanadium alloys and SiC/SiC composites) and austenitic stainless steels. In this study, effect of primary candidate refractory alloys, namely, W-5Re, T111, TZM and Nb-1Zr on neutronic performance of the hybrid reactor was investigated. Neutron transport calculations were conducted with the help of SCALE 4.3 System by solving the Boltzmann transport equation with code XSDRNPM. Among the investigated structural materials, tantalum had the worst performance due to the fact that it has higher neutron absorption cross section than others. And W-5Re and TZM having similar results showed the best performance.

  7. Controlling Torque Distribution for Parallel Hybrid Vehicle Based on Hierarchical Structure Fuzzy Logic

    Institute of Scientific and Technical Information of China (English)

    HuangMiao-hua; JinGuo-dong

    2003-01-01

    The Hierarchical Structure Fuzzy Logic Control(HSFLC) strategies of torque distribute for Parallel Hybrid Electric Vehicle (PHEV) in the mocle of operation of the vehicle i. e. , acceleration, cruise, deceleration etc. have been studied. Using secondly developed the hybrid vehicle simulation tool ADVISOR, the dynamic model of PHEV has been set up by MATLAB/SIMULINK. The engine, motor as well as the battery characteristics have been studied. Simulation results show that the proposed hierarchical structured fuzzy logic control strategy is effective over the entire operating range of the vehicle in terms of fuel economy. Based on the analyses of the simulation results and driver's experiences, a fuzzy controller is designed and developed to control the torque distribution. The controller is evaluated via hardware-in-the-loop simulator (HILS). The results show that controller verify its value.

  8. Research Update: The electronic structure of hybrid perovskite layers and their energetic alignment in devices

    Directory of Open Access Journals (Sweden)

    Selina Olthof

    2016-09-01

    Full Text Available In recent years, the interest in hybrid organic–inorganic perovskites has increased at a rapid pace due to their tremendous success in the field of thin film solar cells. This area closely ties together fundamental solid state research and device application, as it is necessary to understand the basic material properties to optimize the performances and open up new areas of application. In this regard, the energy levels and their respective alignment with adjacent charge transport layers play a crucial role. Currently, we are lacking a detailed understanding about the electronic structure and are struggling to understand what influences the alignment, how it varies, or how it can be intentionally modified. This research update aims at giving an overview over recent results regarding measurements of the electronic structure of hybrid perovskites using photoelectron spectroscopy to summarize the present status.

  9. Multi-locus estimates of population structure and migration in a fence lizard hybrid zone.

    Directory of Open Access Journals (Sweden)

    Adam D Leaché

    Full Text Available A hybrid zone between two species of lizards in the genus Sceloporus (S. cowlesi and S. tristichus on the Mogollon Rim in Arizona provides a unique opportunity to study the processes of lineage divergence and merging. This hybrid zone involves complex interactions between 2 morphologically and ecologically divergent subspecies, 3 chromosomal groups, and 4 mitochondrial DNA (mtDNA clades. The spatial patterns of divergence between morphology, chromosomes and mtDNA are discordant, and determining which of these character types (if any reflects the underlying population-level lineages that are of interest has remained impeded by character conflict. The focus of this study is to estimate the number of populations interacting in the hybrid zone using multi-locus nuclear data, and to then estimate the migration rates and divergence time between the inferred populations. Multi-locus estimates of population structure and gene flow were obtained from 12 anonymous nuclear loci sequenced for 93 specimens of Sceloporus. Population structure estimates support two populations, and this result is robust to changes to the prior probability distribution used in the Bayesian analysis and the use of spatially-explicit or non-spatial models. A coalescent analysis of population divergence suggests that gene flow is high between the two populations, and that the timing of divergence is restricted to the Pleistocene. The hybrid zone is more accurately described as involving two populations belonging to S. tristichus, and the presence of S. cowlesi mtDNA haplotypes in the hybrid zone is an anomaly resulting from mitochondrial introgression.

  10. Dispersing perylene diimide/SWCNT hybrids: structural insights at the molecular level and fabricating advanced materials.

    Science.gov (United States)

    Tsarfati, Yael; Strauss, Volker; Kuhri, Susanne; Krieg, Elisha; Weissman, Haim; Shimoni, Eyal; Baram, Jonathan; Guldi, Dirk M; Rybtchinski, Boris

    2015-06-17

    The unique properties of carbon nanotubes (CNT) are advantageous for emerging applications. Yet, the CNT insolubility hampers their potential. Approaches based on covalent and noncovalent methodologies have been tested to realize stable dispersions of CNTs. Noncovalent approaches are of particular interest as they preserve the CNT's structures and properties. We report on hybrids, in which perylene diimide (PDI) amphiphiles are noncovalently immobilized onto single wall carbon nanotubes (SWCNT). The resulting hybrids were dispersed and exfoliated both in water and organic solvents in the presence of two different PDI derivatives, PP2b and PP3a. The dispersions were investigated using cryogenic transmission electron microscopy (cryo-TEM), providing unique structural insights into the exfoliation. A helical arrangement of PP2b assemblies on SWCNTs dominates in aqueous dispersions, while a single layer of PP2b and PP3a was found on SWCNTs in organic dispersions. The dispersions were probed by steady-state and time-resolved spectroscopies, revealing appreciable charge redistribution in the ground state, and an efficient electron transfer from SWCNTs to PDIs in the excited state. We also fabricated hybrid materials from the PP2b/SWCNT dispersions. A supramolecular membrane was prepared from aqueous dispersions and used for size-selective separation of gold nanoparticles. Hybrid buckypaper films were prepared from the organic dispersions. In the latter, high conductivity results from enhanced electronic communication and favorable morphology within the hybrid material. Our findings shed light onto SWCNT/dispersant molecular interactions, and introduce a versatile approach toward universal solution processing of SWCNT-based materials.

  11. Clinicopathological analysis of solitary fibrous tumor

    Institute of Scientific and Technical Information of China (English)

    Xiumei Zhang; Hai Wang; Shujing Wang; Jinfeng Miao; Zhengai Piao; Yingying Dong

    2012-01-01

    Objective: The aim of this study was to investigate the clinicopathologic characteristics, diagnosis and differential diagnosis, molecular genetics, treatment and prognosis of solitary fibrous tumor (SFT). Methods: The clinicopathological manifestations were analyzed retrospectively in 22 patients with surgically confirmed SFT. Results: There were 12 male patients and 10 female patients, with the age range 33–67 (mean 48.62) years. The SFTs originated from different from parts of the body, including 13 in the chest, 2 in the lungs, 3 in the abdomen, 1 in the lumbosacral area, 2 in the pelvis, and 1 in the left shoulder. There were 19 benign and 3 malignant tumors. Major clinical presentations were local masses and compression symptoms. Microscopy: the tumor was composed of areas of alternating hypercellularity and hypocellularity. The tumor cells were spindle to short-spindle shaped and arranged in fascicular or storiform pattern and hemangiopericytoma-like structure was presented. Immunohistochemically, Vimentin positive rate was 100% (22/22), Bcl-2 positive rate was 95.5% (21/22), CD99 positive rate was 86.4% (19/22), CD34 positive rate was 81.8 (18/22), focally positive for P53, as well as negative CK, S100 and Desmin. Ki67 labelling index was 2%–30%. Conclusion: SFT is a rare tumor which may be found in various parts of human body. SFT mostly is a benign tumor, but a few could be malignant. Its diagnosis mainly rely on its morphologic features and immunohistochemical profiles. The major treatment is to completely resect it by operation and long-term clinical follow-up is necessary.

  12. Diffraction anomalies in hybrid structures based on chalcogenide-coated opal photonic crystals

    CERN Document Server

    Voronov, M M; Yakovlev, S A; Kurdyukov, D A; Golubev, V G

    2014-01-01

    The results of spectroscopic studies of the diffraction anomalies (the so-called resonant Wood anomalies) in spatially-periodic hybrid structures based on halcogenide (GST225)-coated opal films of various thickness are presented. A theoretical analysis of spectral-angular dependencies of the Wood anomalies has been made by means of a phenomenological approach using the concept of the effective refractive index of waveguiding surface layer.

  13. Structural Stability of Functionalized Silicene Nanoribbons with Normal, Reconstructed, and Hybrid Edges

    OpenAIRE

    Sadegh Mehdi Aghaei; Ingrid Torres; Irene Calizo

    2016-01-01

    Silicene, a novel graphene-like material, has attracted a significant attention because of its potential applications for nanoelectronics. In this paper, we have theoretically investigated the structural stability of edge-hydrogenated and edge-fluorinated silicene nanoribbons (SiNRs) via first-principles calculations. Various edge forms of SiNRs including armchair edge, zigzag edge, Klein edge, reconstructed Klein edge, reconstructed pentagon-heptagon edge, and hybrid edges have been consider...

  14. The topological structure of the integral quantum Hall effect in magnetic semiconductor-superconductor hybrids

    Institute of Scientific and Technical Information of China (English)

    Ren Ji-Rong; Zhu Hui

    2009-01-01

    An unconventional integer quantum Hall regime was found in magnetic semiconductor-superconductor hybrids.By making use of the decomposition of the gauge potential on a U(1) principal fibre bundle over k-space, we study the topological structure of the integral Hall conductance. It is labeled by the Hopf index β and the Brouwer degree η. The Hall conductance topological current and its evolution is discussed.

  15. Hybrid Soft Soil Tire Model (HSSTM). Part 1: Tire Material and Structure Modeling

    Science.gov (United States)

    2015-04-28

    HYBRID SOFT SOIL TIRE MODEL (HSSTM). PART I: TIRE MATERIAL AND STRUCTURE MODELING Taheri, Sh.a,1, Sandu, C.a...model the dynamic behavior of the tire on soft soil , a lumped mass discretized tire model using Kelvin-Voigt elements is developed. To optimize the...terrains (such as sandy loam) and tire force and moments, soil sinkage, and tire deformation data were collected for various case studies based on a

  16. Facile preparation of smooth perovskite films for efficient meso/planar hybrid structured perovskite solar cells.

    Science.gov (United States)

    Zhang, Meng; Yu, Hua; Yun, Jung-Ho; Lyu, Miaoqiang; Wang, Qiong; Wang, Lianzhou

    2015-06-21

    Smooth organolead halide perovskite films for meso/planar hybrid structured perovskite solar cells were prepared by a simple compressed air blow-drying method under ambient conditions. The resultant perovskite films show high surface coverage, leading to a device power conversion efficiency of over 10% with an open circuit voltage up to 1.003 V merely using pristine poly(3-hexylthiophene) (P3HT) as a hole transporter.

  17. Nano- and micro-structured silicon for hybrid near-infrared photodetectors

    Science.gov (United States)

    Äńerek, V.; Głowacki, E. D.; Bednorz, M.; Demchyshyn, S.; Sariciftci, N. S.; Ivanda, M.

    2016-05-01

    Structuring surface and bulk of crystalline silicon on different length scales can significantly alter its properties and possibly improve the performance of opto-electronic devices and sensors based on silicon. Different dominant feature scales are responsible for modification of some of electronic and optical properties of silicon. Several easily reproducible chemical methods for facile structuring of silicon on nano and micro-scales, based on both electroless and anodic etching of silicon in hydrofluoric acid based etchants, and chemical anisotropic etching of silicon in basic environments, are presented. We show how successive micro and nano structuring creates hierarchical silicon surfaces, which can be used to simultaneously exploit the advantages of both structuring feature length scales. Finally, we demonstrate a large increase in photocurrent obtained from a hybrid structured silicon/organic near-infrared photodetector. Improved silicon/6,6'-dibromoindigo hybrid photodiodes were prepared by nano- and micro-structuring the silicon part of the heterojunction by wet chemical etching methods. Photocurrent and spectral responsivity were improved in comparison to planar diodes by up to two orders of magnitude by optimization of the silicon structuring process. We show that the improvement in photocurrent is not due to the increase in surface area or light trapping.

  18. Weakly nonlinear models for internal waves: inverse scattering transform and solitary wave contents

    CERN Document Server

    Chen, Shengqian

    2016-01-01

    The time evolution emanating from ``internal dam-break'' initial conditions is studied for a class of models of stratified Euler fluids in configurations close to two-homogeneous layers separated by a thin diffused interface. Direct numerical simulations and experiments in wave tanks show that such initial conditions eventually give rise to coherent structures that are close to solitary-wave solutions moving ahead of a region of dispersive wave motion and turbulent mixing close to the location of the initial dam step. A priori theoretical predictions of the main features of these solitary waves, such as their amplitudes and speeds, appear to be unavailable, even for simplified models of wave evolution in stratified fluids. With the aim of providing estimates of the existence, amplitude and speed of such solitary waves, an approach based on Inverse Scattering Transform (IST) for completely integrable models is developed here and tested against direct numerical simulations of Euler fluids and some of their mode...

  19. Propagation of ion-acoustic solitary waves in a relativistic electron-positron-ion plasma

    CERN Document Server

    Saberian, E; Akbari-Moghanjoughi, M

    2011-01-01

    Propagation of large amplitude ion-acoustic solitary waves (IASWs) in a fully relativistic plasma consisting of cold ions and ultrarelativistic hot electrons and positrons is investigated using the Sagdeev's pseudopotential method in a relativistic hydrodynamics model. Effects of streaming speed of plasma fluid, thermal energy, positron density and positron temperature on large amplitude IASWs are studied by analysis of the pseudopotential structure. It is found that in regions that the streaming speed of plasma fluid is larger than that of solitary wave, by increasing the streaming speed of plasma fluid the depth and width of potential well increases and resulting in narrower solitons with larger amplitude. This behavior is opposite for the case where the streaming speed of plasma fluid is smaller than that of solitary wave. On the other hand, increase of the thermal energy results in wider solitons with smaller amplitude, because the depth and width of potential well decreases in that case. Additionally, th...

  20. Solitary fibrous tumor of the sellar region treated with adjuvant radiation therapy

    Science.gov (United States)

    Sahai, Puja; Singh, Geetika; Mondal, Dodul; Suri, Vaishali; Julka, Pramod Kumar

    2016-01-01

    The solitary fibrous tumor of central nervous system is rare. Herein, a case of solitary fibrous tumor arising from sellar region is described. A 60-year-old man underwent subtotal excision of the tumor because of extensive infiltration of optical and vascular structures. In view of the presence of residual tumor, he was treated with adjuvant radiation therapy. After a follow-up period of 1 year, there was no progression of the lesion evident on magnetic resonance imaging of the brain. Solitary fibrous tumor should be considered as one of the differential diagnosis of a mass lesion arising in sellar region. Immunohistochemistry with CD34 is valuable for discerning the diagnosis. Complete surgery should be the goal of treatment and adjuvant radiation therapy may be considered for residual or recurrent disease. PMID:27695561

  1. Application of Nuclear Magnetic Resonance and Hybrid Methods to Structure Determination of Complex Systems.

    Science.gov (United States)

    Prischi, Filippo; Pastore, Annalisa

    2016-01-01

    The current main challenge of Structural Biology is to undertake the structure determination of increasingly complex systems in the attempt to better understand their biological function. As systems become more challenging, however, there is an increasing demand for the parallel use of more than one independent technique to allow pushing the frontiers of structure determination and, at the same time, obtaining independent structural validation. The combination of different Structural Biology methods has been named hybrid approaches. The aim of this review is to critically discuss the most recent examples and new developments that have allowed structure determination or experimentally-based modelling of various molecular complexes selecting them among those that combine the use of nuclear magnetic resonance and small angle scattering techniques. We provide a selective but focused account of some of the most exciting recent approaches and discuss their possible further developments.

  2. Hybrid metal-dielectric, slow wave structure with magnetic coupling and compensation

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, A.V., E-mail: asmirnov@radiabeam.com [RadiaBeam Systems LLC, 1713 Stewart St., Santa Monica, CA 90404 (United States); Savin, E. [RadiaBeam Systems LLC, 1713 Stewart St., Santa Monica, CA 90404 (United States); National Research Nuclear University “MEPhI”, Moscow 115409 (Russian Federation)

    2016-06-01

    A number of electron beam vacuum devices such as small radiofrequency (RF) linear accelerators (linacs) and microwave traveling wave tubes (TWTs) utilize slow wave structures which are usually rather complicated in production and may require multi-step brazing and time consuming tuning. Fabrication of these devices becomes challenging at centimeter wavelengths, at large number of cells, and when a series or mass production of such structures is required. A hybrid, metal-dielectric, periodic structure for low gradient, low beam current applications is introduced here as a modification of Andreev’s disk-and-washer (DaW) structure. Compensated type of coupling between even and odd TE01 modes in the novel structure results in negative group velocity with absolute values as high as 0.1c–0.2c demonstrated in simulations. Sensitivity to material imperfections and electrodynamic parameters of the disk-and-ring (DaR) structure are considered numerically using a single cell model.

  3. Multifunctional hybrid porous filters with hierarchical structures for simultaneous removal of indoor VOCs, dusts and microorganisms.

    Science.gov (United States)

    Zhao, Yang; Low, Ze-Xian; Feng, Shasha; Zhong, Zhaoxiang; Wang, Yong; Yao, Zhong

    2017-02-23

    Air purification often requires multiple layers of filters with different functions to remove various air pollutants, which lead to high pressure drop, high air flow path and frequent filter replacement. In this work, a novel multifunctional Ag@MWCNTs/Al2O3 hybrid filter with a depth-type hierarchical structure for simultaneous removal of fine particles, microorganisms and VOCs was designed and fabricated. The novel hybrid air filter showed leading air purification performances to date, achieving 82.24% degradation of formaldehyde at room temperature, 99.99% formaldehyde degradation at 55 °C and complete retention of indoor airborne microorganisms. The complete particle retention rate (100% retention) based on the most penetrating particle size (MPPS, aerodynamic diameter ≦300 nm) of Ag@MWCNTs/Al2O3 was achieved at an only 35.60% pressure drop compared with the pristine Al2O3 filter, leading to the highest quality factor (Qf) ever reported. Furthermore, the Ag@MWCNTs/Al2O3 hybrid filter showed excellent water repellency (water contact angle of 139.6 ± 2.9°), prolonging the service life of the filters and improving the air purification efficiency. The novel Ag@MWCNTs/Al2O3 hybrid filter exhibits remarkable air purification performance in both laboratory synthetic conditions as well as in the "real world" and shows great promise as an effective single replacement for multiple layers of air purifying filters.

  4. Optoelectronic Properties of Van Der Waals Hybrid Structures: Fullerenes on Graphene Nanoribbons

    Science.gov (United States)

    Correa, Julián David; Orellana, Pedro Alejandro; Pacheco, Mónica

    2017-01-01

    The search for new optical materials capable of absorbing light in the frequency range from visible to near infrared is of great importance for applications in optoelectronic devices. In this paper, we report a theoretical study of the electronic and optical properties of hybrid structures composed of fullerenes adsorbed on graphene and on graphene nanoribbons. The calculations are performed in the framework of the density functional theory including the van der Waals dispersive interactions. We found that the adsorption of the C60 fullerenes on a graphene layer does not modify its low energy states, but it has strong consequences for its optical spectrum, introducing new absorption peaks in the visible energy region. The optical absorption of fullerenes and graphene nanoribbon composites shows a strong dependence on photon polarization and geometrical characteristics of the hybrid systems, covering a broad range of energies. We show that an external electric field across the nanoribbon edges can be used to tune different optical transitions coming from nanoribbon–fullerene hybridized states, which yields a very rich electro-absorption spectrum for longitudinally polarized photons. We have carried out a qualitative analysis on the potential of these hybrids as possible donor-acceptor systems in photovoltaic cells. PMID:28336904

  5. Nacre-like hybrid films: Structure, properties, and the effect of relative humidity.

    Science.gov (United States)

    Abba, Mohammed T; Hunger, Philipp M; Kalidindi, Surya R; Wegst, Ulrike G K

    2015-03-01

    Functional materials often are hybrids composed of biopolymers and mineral constituents. The arrangement and interactions of the constituents frequently lead to hierarchical structures with exceptional mechanical properties and multifunctionality. In this study, hybrid thin films with a nacre-like brick-and-mortar microstructure were fabricated in a straightforward and reproducible manner through manual shear casting using the biopolymer chitosan as the matrix material (mortar) and alumina platelets as the reinforcing particles (bricks). The ratio of inorganic to organic content was varied from 0% to 15% and the relative humidities from 36% to 75% to determine their effects on the mechanical properties. It was found that increasing the volume fraction of alumina from 0% to 15% results in a twofold increase in the modulus of the film, but decreases the tensile strength by up to 30%, when the volume fraction of alumina is higher than 5%. Additionally, this study quantifies and illustrates the critical role of the relative humidity on the mechanical properties of the hybrid film. Increasing the relative humidity from 36% to 75% decreases the modulus and strength by about 45% and triples the strain at failure. These results suggest that complex hybrid materials can be manufactured and tailor made for specific applications or environmental conditions.

  6. Insect damages on structural, morphologic and composition of Bt maize hybrids to silage

    Directory of Open Access Journals (Sweden)

    Geraldo Balieiro Neto

    2013-03-01

    Full Text Available It was aimed to evaluate the effect of insect damage on the morphologic and structural characteristics and chemical composition from maize hybrids DKB 390 and AG 8088 with the Cry1Ab trait versus its nonbiotech counterpart. The GMO did not receive insecticide application and the conventional hybrids received one deltametrina (2.8% application at 42 days. The damages caused bySpodoptera frugiperda and Helicoverpa zea in hybrids with Cry1Ab were smaller than its nonbiotech counterpart. After harvest, 95 days after seedling plants were separated in stalks, ears, leafs, dead leafs and floral pennant. The experimental design was randomized block in factorial arrangement 2 x 2. The height of plant and height of ear, percentage and amount of dead leafs from hybrids with the Cry1Ab were higher than its nonbiotech counterpart. There was higher nutrients transfer from stalks to grain filling and smaller rate stalks:ear on transgenic plant. The quality of the transgenic plants can be better when harvest earlier, by increasing no fiber carbohydrates, but when harvest latter, by increasing stalk percentage and stalk lignin content.

  7. Enhanced Mechanical Performance of Bio-Inspired Hybrid Structures Utilising Topological Interlocking Geometry

    Science.gov (United States)

    Djumas, Lee; Molotnikov, Andrey; Simon, George P.; Estrin, Yuri

    2016-05-01

    Structural composites inspired by nacre have emerged as prime exemplars for guiding materials design of fracture-resistant, rigid hybrid materials. The intricate microstructure of nacre, which combines a hard majority phase with a small fraction of a soft phase, achieves superior mechanical properties compared to its constituents and has generated much interest. However, replicating the hierarchical microstructure of nacre is very challenging, not to mention improving it. In this article, we propose to alter the geometry of the hard building blocks by introducing the concept of topological interlocking. This design principle has previously been shown to provide an inherently brittle material with a remarkable flexural compliance. We now demonstrate that by combining the basic architecture of nacre with topological interlocking of discrete hard building blocks, hybrid materials of a new type can be produced. By adding a soft phase at the interfaces between topologically interlocked blocks in a single-build additive manufacturing process, further improvement of mechanical properties is achieved. The design of these fabricated hybrid structures has been guided by computational work elucidating the effect of various geometries. To our knowledge, this is the first reported study that combines the advantages of nacre-inspired structures with the benefits of topological interlocking.

  8. Tuning Structure and Properties of Graded Triblock Terpolymer-Based Mesoporous and Hybrid Films

    KAUST Repository

    Phillip, William A.

    2011-07-13

    Despite considerable efforts toward fabricating ordered, water-permeable, mesoporous films from block copolymers, fine control over pore dimensions, structural characteristics, and mechanical behavior of graded structures remains a major challenge. To this end, we describe the fabrication and performance characteristics of graded mesoporous and hybrid films derived from the newly synthesized triblock terpolymer, poly(isoprene-b-styrene-b-4-vinylpyridine). A unique morphology, unachievable in diblock copolymer systems, with enhanced mechanical integrity is evidenced. The film structure comprises a thin selective layer containing vertically aligned and nearly monodisperse mesopores at a density of more than 1014 per m2 above a graded macroporous layer. Hybridization via homopolymer blending enables tuning of pore size within the range of 16 to 30 nm. Solvent flow and solute separation experiments demonstrate that the terpolymer films have permeabilities comparable to commercial membranes, are stimuli-responsive, and contain pores with a nearly monodisperse diameter. These results suggest that moving to multiblock polymers and their hybrids may open new paths to produce high-performance graded membranes for filtration, separations, nanofluidics, catalysis, and drug delivery. © 2011 American Chemical Society.

  9. Investigation of a hybrid structure gaseous detector for ion backflow suppression suppression

    CERN Document Server

    Zhang, YuLian; Hu, BiTao

    2016-01-01

    A new concept for ion backflow suppression in future time projection chamber with Micropattern Gas Detectors readout is presented. It is a hybrid structure cascaded Gas Electron Multiplier with Micromegas with the goal to reduce ion backflow from the amplification region towards the drift volume. Gas Electron Multiplier also acting as a preamplifer and shares gas gain with Micromegas. In this way a lower voltage difference has to be applied to the Micromegas and risk of sparking is reduced. Feasibility tests for the hybrid detector is performed using an $^{55}$Fe X-ray source to evaluate the energy resolution, its gain properties and the ion backflow. %The properties of this novel structure in terms of gain and ion backflow are investigated. The energy resolution is better than 27$\\%$ FWHM for 5.9 keV X-rays. It is demonstrated that at a gain up to 6000, a backflow ratio less than 0.3$\\%$ is reachable in the hybrid readout structure.

  10. Contributions of each isotope in structural material on radiation damage in a hybrid reactor

    Science.gov (United States)

    Günay, Mehtap

    2016-11-01

    In this study, the fluids were used in the liquid first-wall, blanket and shield zones of the designed hybrid reactor system. In this study, salt-heavy metal mixtures consisting of 93-85% Li20Sn80 + 5% SFG-PuO2 and 2-10% UO2, 93-85% Li20Sn80 + 5% SFG-PuO2 and 2-10% NpO2, and 93-85% Li20Sn80 + 5% SFG-PuO2 and 2-10% UCO were used as fluids. In this study, the effect on the radiation damage of spent fuel-grade (SFG)-PuO2, UO2, NpO2 and UCO contents was investigated in the structural material of a designed fusion-fission hybrid reactor system. In the designed hybrid reactor system were investigated the effect on the radiation damage of the selected fluid according to each isotopes of structural material in the structural material for 30 full power years (FPYs). Three-dimensional analyses were performed using the most recent MCNPX-2.7.0 Monte Carlo radiation transport code and the ENDF/B-VII.0 nuclear data library.

  11. CPU-GPU hybrid accelerating the Zuker algorithm for RNA secondary structure prediction applications.

    Science.gov (United States)

    Lei, Guoqing; Dou, Yong; Wan, Wen; Xia, Fei; Li, Rongchun; Ma, Meng; Zou, Dan

    2012-01-01

    Prediction of ribonucleic acid (RNA) secondary structure remains one of the most important research areas in bioinformatics. The Zuker algorithm is one of the most popular methods of free energy minimization for RNA secondary structure prediction. Thus far, few studies have been reported on the acceleration of the Zuker algorithm on general-purpose processors or on extra accelerators such as Field Programmable Gate-Array (FPGA) and Graphics Processing Units (GPU). To the best of our knowledge, no implementation combines both CPU and extra accelerators, such as GPUs, to accelerate the Zuker algorithm applications. In this paper, a CPU-GPU hybrid computing system that accelerates Zuker algorithm applications for RNA secondary structure prediction is proposed. The computing tasks are allocated between CPU and GPU for parallel cooperate execution. Performance differences between the CPU and the GPU in the task-allocation scheme are considered to obtain workload balance. To improve the hybrid system performance, the Zuker algorithm is optimally implemented with special methods for CPU and GPU architecture. Speedup of 15.93× over optimized multi-core SIMD CPU implementation and performance advantage of 16% over optimized GPU implementation are shown in the experimental results. More than 14% of the sequences are executed on CPU in the hybrid system. The system combining CPU and GPU to accelerate the Zuker algorithm is proven to be promising and can be applied to other bioinformatics applications.

  12. The solitary sellar plasmacytoma: a diagnostic challenge

    DEFF Research Database (Denmark)

    Soejbjerg, Anne; Dyve, Suzan; Baerentzen, Steen

    2016-01-01

    UNLABELLED: Solitary sellar plasmacytomas are exceedingly rare and difficult to distinguish from other pituitary tumors. We report a case of a 62-year-old woman presenting with blurred vision of the right eye and tenderness of the right temporal region, which was interpreted as temporal arteritis...

  13. Clinical implications of the solitary functioning kidney

    NARCIS (Netherlands)

    Westland, R.; Schreuder, M.F.; Goudoever, J.B. van; Sanna-Cherchi, S.; Wijk, J.A. van

    2014-01-01

    Congenital anomalies of the kidney and urinary tract are the major cause of ESRD in childhood. Children with a solitary functioning kidney form an important subgroup of congenital anomalies of the kidney and urinary tract patients, and a significant fraction of these children is at risk for progress

  14. Solitary waves on nonlinear elastic rods. I

    DEFF Research Database (Denmark)

    Sørensen, Mads Peter; Christiansen, Peter Leth; Lomdahl, P. S.

    1984-01-01

    Acoustic waves on elastic rods with circular cross section are governed by improved Boussinesq equations when transverse motion and nonlinearity in the elastic medium are taken into account. Solitary wave solutions to these equations have been found. The present paper treats the interaction between...

  15. Shallow Water Waves and Solitary Waves

    CERN Document Server

    Hereman, Willy

    2013-01-01

    Encyclopedic article covering shallow water wave models used in oceanography and atmospheric science. Sections: Definition of the Subject; Introduction and Historical Perspective; Completely Integrable Shallow Water Wave Equations; Shallow Water Wave Equations of Geophysical Fluid Dynamics; Computation of Solitary Wave Solutions; Numerical Methods; Water Wave Experiments and Observations; Future Directions, and Bibliography.

  16. Solitary waves on nonlinear elastic rods. II

    DEFF Research Database (Denmark)

    Sørensen, Mads Peter; Christiansen, Peter Leth; Lomdahl, P. S.

    1987-01-01

    In continuation of an earlier study of propagation of solitary waves on nonlinear elastic rods, numerical investigations of blowup, reflection, and fission at continuous and discontinuous variation of the cross section for the rod and reflection at the end of the rod are presented. The results...

  17. Giant solitary fibrous tumour of the liver

    NARCIS (Netherlands)

    T. Terkivatan (Türkan); M. Kliffen (Mike); J.H.W. de Wilt (Johannes); A.N. van Geel (Albert); A.M.M. Eggermont (Alexander); C. Verhoef (Kees)

    2006-01-01

    textabstractBackground: Solitary fibrous tumour (SFT) is an uncommon mesenchymal neoplasm that most frequently affects the pleura, although it has been reported with increasing frequency in various other sites such as in the peritoneum, pericardium and in non-serosal sites such as lung parenchyma,

  18. Solitary Wave Solutions for Zoomeron Equation

    Directory of Open Access Journals (Sweden)

    Amna IRSHAD

    2013-04-01

    Full Text Available Tanh-Coth Method is applied to find solitary wave solutions of the Zoomeron equation which is of extreme importance in mathematical physics. The proposed scheme is fully compatible with the complexity of the problem and is highly efficient. Moreover, suggested combination is capable to handle nonlinear problems of versatile physical nature.

  19. Solitary fibrous tumour of the vagus nerve.

    Science.gov (United States)

    Scholsem, Martin; Scholtes, Felix

    2012-04-01

    We describe the complete removal of a foramen magnum solitary fibrous tumour in a 36-year-old woman. It originated on a caudal vagus nerve rootlet, classically described as the 'cranial' accessory nerve root. This ninth case of immunohistologically confirmed cranial or spinal nerve SFT is the first of the vagus nerve.

  20. Solitary Wave Propagation Influenced by Submerged Breakwater

    Institute of Scientific and Technical Information of China (English)

    王锦; 左其华; 王登婷

    2013-01-01

    The form of Boussinesq equation derived by Nwogu (1993) using velocity at an arbitrary distance and surface elevation as variables is used to simulate wave surface elevation changes. In the numerical experiment, water depth was divided into five layers with six layer interfaces to simulate velocity at each layer interface. Besides, a physical experiment was carried out to validate numerical model and study solitary wave propagation.“Water column collapsing”method (WCCM) was used to generate solitary wave. A series of wave gauges around an impervious breakwater were set-up in the flume to measure the solitary wave shoaling, run-up, and breaking processes. The results show that the measured data and simulated data are in good agreement. Moreover, simulated and measured surface elevations were analyzed by the wavelet transform method. It shows that different wave frequencies stratified in the wavelet amplitude spectrum. Finally, horizontal and vertical velocities of each layer interface were analyzed in the process of solitary wave propagation through submerged breakwater.

  1. Solitary wave interactions of the GRLW equation

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, J.I. [Room I-320-D, E.T.S. Ingenieros Industriales, Universidad de Malaga, Plaza El Ejido, s/n 29013 Malaga (Spain)]. E-mail: jirs@lcc.uma.es

    2007-07-15

    An approximate quasilinearization method for the solution of the generalized regularized long-wave (GRLW) equation based on the separation of the temporal and spatial derivatives, three-point, fourth-order accurate, compact difference equations, is presented. The method results in a system of linear equations with tridiagonal matrices, and is applied to determine the effects of the parameters of the GRLW equation and initial conditions on the formation of undular bores and interactions/collisions between two solitary waves. It is shown that the method preserves very accurately the first two invariants of the GRLW equation, the formation of secondary waves is a strong function of the amplitude and width of the initial Gaussian conditions, and the collision between two solitary waves is a strong function of the parameters that appear in the GRLW equation and the amplitude and speed of the initial conditions. It is also shown that the steepening of the leading and trailing waves may result in the formation of multiple secondary waves and/or an undular bore; the former interacts with the trailing solitary wave which may move parallel to or converge onto the leading solitary wave.

  2. [Characteristics of canopy structure of super high yielding japonica hybrid rice community].

    Science.gov (United States)

    Chen, Jinhong; Zhang, Guoping; Guo, Hengde; Mao, Guojuan

    2003-06-01

    In this paper, the characteristics of canopy structure, such as the numbers of seedling, panicle and grain, the distribution of dry matters in different canopy layers and different organs, and the distributions of LAI and of solar radiation in different canopy layers of super high yielding community of japonica hybrid rice were studied, in comparison with normal japonica rice. The results showed that the total the dry matter weight and the dry matter weight of layers below 40 cm, 40-60 cm, 60-80 cm and above 80 cm of japonica hybrid rice canopy were 32.29%, 29.12%, 13.95%, 16.45% and 100.17% higher those that of normal japonica rice, respectively. The ratios of dry leaf (photosynthetic organ) and of dry panicle (sink organ) weight to total dry weight were 24.8% and 12.8%, respectively, which were greater than those of normal japonica rice, while the ratios of dry sheath and stem (storage organs) weight were 33.6% and 28.9%, respectively, which were lower than those of normal japonica rice. The allotment of LAI in different layers of japonica hybrid rice canopy was reasonable, and the LAI of above 40 cm layer at full heading stage reached 5.44. The solar radiation was well-distributed inside japonica hybrid rice canopy, for example, the solar radiation in layers below 60 cm were 13.1%-37.0% higher, but 5.9%-12.2% lower above 60 cm than that of normal japonica rice. The extinction coefficients of solar radiation in layers below 20 cm, 20-40 cm, 40-60 cm and 60-80 cm of japonica hybrid rice canopy were 35.1%, 13.5%, 29.1% and 17.2% lower than that of normal japonica rice, respectively.

  3. Rate-prediction structure complexity analysis for multi-view video coding using hybrid genetic algorithms

    Science.gov (United States)

    Liu, Yebin; Dai, Qionghai; You, Zhixiang; Xu, Wenli

    2007-01-01

    Efficient exploitation of the temporal and inter-view correlation is critical to multi-view video coding (MVC), and the key to it relies on the design of prediction chain structure according to the various pattern of correlations. In this paper, we propose a novel prediction structure model to design optimal MVC coding schemes along with tradeoff analysis in depth between compression efficiency and prediction structure complexity for certain standard functionalities. Focusing on the representation of the entire set of possible chain structures rather than certain typical ones, the proposed model can given efficient MVC schemes that adaptively vary with the requirements of structure complexity and video source characteristics (the number of views, the degrees of temporal and interview correlations). To handle large scale problem in model optimization, we deploy a hybrid genetic algorithm which yields satisfactory results shown in the simulations.

  4. Design and Fabrication of a Novel Hybrid-Structure Heat Pipe for a Concentrator Photovoltaic

    Directory of Open Access Journals (Sweden)

    Heiu-Jou Shaw

    2012-10-01

    Full Text Available This study presents a design method to fabricate a novel hybrid-structure flat plate heat pipe (NHSP heat pipe for a concentrator photovoltaic. The NHSP heat pipe is composed of a flattened copper pipe and a sintered wick structure, and a coronary-stent-like rhombic copper mesh supports the structure. The coronary-stent-like supporting structure enhances the mechanical strength and shortens the reflux path of the working fluid. Experiments demonstrate that the sintered capillary heat pipe reduces the thermal resistance by approximately 72%, compared to a traditional copper mesh-screen heat pipe. Furthermore, it can reduce thermal resistance by 65% after a supporting structure is added to the heat pipe. The results show that the NHSP heat pipe provided the best performance for the concentrator photovoltaic, which can increase photoelectric conversion efficiency by approximately 3.1%, compared to an aluminum substrate.

  5. Cracked structure-acoustic coupling problems by hybrid fractal FE and BE methods

    Institute of Scientific and Technical Information of China (English)

    吴国荣; 仲伟芳

    2004-01-01

    Evaluation of the sound-structure interaction is important for effective control of noise and vibration in structural acoustic systems. Cracked elastic structure-sound interaction problems are studied by employing the hybrid fractal FEM and BEM. The degrees of freedom of the system can be reduced greatly through adopting fractal FEM in discretizing the cracked elastic structure; while the exterior acoustic field is calculated by BEM, which automatically satisfies Sommerfeld's radiation condition. Numerical examples are given and show that the resonant frequencies of the structure-acoustic coupled system decrease as the depth of the crack increases, and that the crack has a significant effect on the acoustical field in the vicinity of the crack tip.

  6. Active vibration control of hybrid smart structures featuring piezoelectric films and electrorheological fluids

    Science.gov (United States)

    Choi, Seung-Bok; Park, Yong-Kun; Cheong, ChaeCheon

    1996-05-01

    This paper presents a proof-of-concept investigation on an active vibration control of a hybrid smart structure (HSS) consisting of a piezoelectric film actuator (PFA) and an electro- rheological fluid actuator (ERFA). Firstly, an HSS beam is constructed by inserting a starch- based electro-rheological fluid into a hollow composite beam and perfectly bonding two piezoelectric films on the upper and lower surfaces of the structure as an actuator and as a sensor, respectively. As for the PFA, a neuro-sliding mode controller (NSC) incorporating neural networks with the concept of sliding mode control is formulated. On the other hand, the control scheme for the ERFA is developed as a function of excitation frequencies on the basis of field-dependent frequency responses. An experimental implementation for the PFA and ERFA is then established to perform an active vibration control of the HSS in the transient and forced vibrations. Both the increment of damping ratios and the suppression of tip deflections are evaluated in order to demonstrate control effectiveness of the PFA, the ERFA, and the hybrid actuation. The experimental results exhibit a superior ability of the hybrid actuation system to tailor elastodynamic responses of the HSS rather than a single class of actuation system alone.

  7. Photodetectors Based on Two-Dimensional Layer-Structured Hybrid Lead Iodide Perovskite Semiconductors.

    Science.gov (United States)

    Zhou, Jiachen; Chu, Yingli; Huang, Jia

    2016-10-05

    Hybrid lead iodide perovskite semiconductors have attracted intense research interests recently because of their easy fabrication processes and high power conversion efficiencies in photovoltaic applications. Layer-structured materials have interesting properties such as quantum confinement effect and tunable band gap due to the unique two-dimensional crystalline structures. ⟨100⟩-oriented layer-structured perovskite materials are inherited from three-dimensional ABX3 perovskite materials with a generalized formula of (RNH3)2(CH3NH3)n-1MnX3n+1, and adopt the Ruddlesden-Popper type crystalline structure. Here we report the synthesis and investigation of three layer-structured perovskite materials with different layer numbers: (C4H9NH3)2PbI4 (n = 1, one-layered perovskite), (C4H9NH3)2(CH3NH3)Pb2I7 (n = 2, two-layered perovskite) and (C4H9NH3)2(CH3NH3)2Pb3I10 (n = 3, three-layered perovskite). Their photoelectronic properties were investigated in related to their molecular structures. Photodetectors based on these two-dimensional (2D) layer-structured perovskite materials showed tunable photoresponse with short response time in milliseconds. The photodetectors based on three-layered perovskite showed better performances than those of the other two devices, in terms of output current, responsivity, Ilight/Idark ratio, and response time, because of its smaller optical band gap and more condensed microstructure comparing the other two materials. These results revealed the relationship between the molecular structures, film microstructures and the photoresponse properties of 2D layer-structured hybrid perovskites, and demonstrated their potentials as flexible, functional, and tunable semiconductors in optoelectronic applications, by taking advantage of their tunable quantum well molecular structure.

  8. Electronic structures of one-dimensional metal-molecule hybrid chains studied using scanning tunneling microscopy and density functional theory.

    Science.gov (United States)

    Chung, Kyung-Hoon; Koo, Bon-Gil; Kim, Howon; Yoon, Jong Keon; Kim, Ji-Hoon; Kwon, Young-Kyun; Kahng, Se-Jong

    2012-05-28

    The electronic structures of self-assembled hybrid chains comprising Ag atoms and organic molecules were studied using scanning tunneling microscopy (STM) and spectroscopy (STS) in parallel with density functional theory (DFT). Hybrid chains were prepared by catalytic breaking of Br-C bonds in 4,4″-dibromo-p-terphenyl molecules, followed by spontaneous formation of Ag-C bonds on Ag(111). An atomic model was proposed for the observed hybrid chain structures. Four electronic states were resolved using STS measurements, and strong energy dependence was observed in STM images. These results were explained using first-principles calculations based on DFT.

  9. Hybrid passive-active modal networks for structural acoustic control (Conference Presentation)

    Science.gov (United States)

    Cunefare, Kenneth A.; Lossouarn, Boris; Collet, Manuel

    2017-04-01

    Distributions of piezoelectric patches bonded to structures provide a means to alter or control, through active or passive means, the dynamic response of the host structure. Numerous active control schemes for such composite structures have been explored. Alternatively, for certain structures, a passive electrical network may be implemented which presents an electrical analog of the modal response of the structure, effectively providing a multi-modal, distributed passive tuned mass modal damper capability. Numerous tuned-mass damper design concepts ("tunings") may be applied to such a passive network. Further, the distributed network analog, when coupled with active control concepts, permits a hybrid distributed passive-active modal control capability. This paper explores this hybrid distributed network control concept applied to a clamped rectangular plate. A unit-cell discrete representation of the plate leads to an electrical analog comprised of passive inductors, transformers and resistors. Addition of synthetic (or controlled) impedances at a limited set of points within the network permits dynamic adjustment of the frequency response of the system.

  10. Synthesis of Metal-Oxide/Organic Hybrids: Structures, Bandgap Sizes, and Photocatalytic Activities

    Science.gov (United States)

    Luo, Lan

    Photocatalysis research has attracted intense current attention for the development of new sources of renewable energy from sunlight. Mixed-metal oxides that comprise an early transition metal (e.g., d0 electronic configuration) with a late transition metal(e.g., d10 electronic configuration) demonstrate significant promise in the red-shifting of the bandgap sizes of simpler metal oxides into the visible-light energy range, and for thus enabling visible-light driven photocatalysis. However, the lack of a significant molecular-level control over their structures and bonding limits the current synthetic abilities to prepare potentially more efficient photocatalysts. Metal-oxide/organic hybrids are materials containing both extended metaloxide connectivity and coordinating organic ligands. These materials have also been the focus of intense research owing to the molecular-level manipulation of their solid-state structures which can be used to control their physical properties, as has been previously applied in many other research areas. Research efforts herein are focused on the investigation of metal-oxide/organic hybrids and their structures, optical bandgap sizes, and photocatalytic properties. The approach to the photocatalysis research begins with the hydrothermal syntheses of specific hybrid materials that can fulfill the band-energy requirements for visible-light absorption through the use of mixed-metal systemswithd5 and d0or d10 and d0 electron configurations, specifically in the Mn(II)/V(V) and Cu(I)/Mo(VI) systems. Optical bandgap sizes were measured by UV-Vis diffuse reflectance spectroscopy and surfaces areas were characterized by BET measurements. The first measured photocatalytic activities for total water splitting and/or hydrogen production for hybrid oxide/organic materials were measured under both visible-light or ultraviolet irradiation in aqueous solutions. Optical bandgap size sand photocatalytic activities were strongly influenced by the

  11. Structural and mechanical properties of cellulose acetate/graphene hybrid nanofibers: Spectroscopic investigations

    Directory of Open Access Journals (Sweden)

    B. S. Kim

    2013-06-01

    Full Text Available Cellulose acetate/graphene (CA/graphene and cellulose acetate/graphene-COOH (CA/graphene-COOH hybrid nanofibers were fabricated via electrospinning technique, and their morphologies, crystallinity and mechanical properties were investigated. The added amounts of graphene and graphene-COOH were varied from 0.5 to 5.0 wt%. The crystal structures and morphologies of the resultant hybrid nanofibers were investigated by wide angle X-ray diffraction (WAXD, scanning electron microscopy (SEM and transmission electron microscopy (TEM, respectively. Graphene-COOH incorporated CA nanofiber mats showed higher Young’s modulus of about 910 MPa among than those of CA/graphene nanofibers, which is due to molecular interactions between –COOH groups in acid-treated graphene and C=O groups in CA via hydrogen bonding. This specific interaction was demonstrated by spectroscopic studies (Raman and Fourier transform infrared (FT-IR spectroscopies.

  12. Processing, structure and flexural strength of CNT and carbon fibre reinforced, epoxy-matrix hybrid composite

    Indian Academy of Sciences (India)

    K Chandra Shekar; M Sai Priya; P K Subramanian; Anil Kumar; B Anjaneya Prasad; N Eswara Prasad

    2014-05-01

    Advanced materials such as continuous fibre-reinforced polymer matrix composites offer significant enhancements in variety of properties, as compared to their bulk, monolithic counterparts. These properties include primarily the tensile stress, flexural stress and fracture parameters. However, till date, there are hardly any scientific studies reported on carbon fibre (Cf) and carbon nanotube (CNT) reinforced hybrid epoxy matrix composites (unidirectional). The present work is an attempt to bring out the flexural strength properties along with a detailed investigation in the synthesis of reinforced hybrid composite. In this present study, the importance of alignment of fibre is comprehensively evaluated and reported. The results obtained are discussed in terms of material characteristics, microstructure and mode of failure under flexural (3-point bend) loading. The study reveals the material exhibiting exceptionally high strength values and declaring itself as a material with high strength to weight ratio when compared to other competing polymer matrix composites (PMCs); as a novel structural material for aeronautical and aerospace applications.

  13. Theoretical investigation of the electronic structures and carrier transport of hybrid graphene and boron nitride nanostructure

    Directory of Open Access Journals (Sweden)

    Jia-Tao Sun

    2012-09-01

    graphene and hexagonal boron nitride (C-BN nanostructures receive much research interest due to the complementary electronic properties. Graphene is a zero-gap semiconductor, while hexagonal boron nitride (h-BN is a wide gap semiconductor. Here we studied the electronic structures and carrier transport of hybrid C-BN nanostructures by using first principles calculations and deformation potential theory. We have found that the physical quantities in these systems under study, band gap, effective mass, deformation potential, and carrier mobility, can be categorised into three different families depending on the width of graphene nanoribbon. This family behavior is similar to pristine armchair graphene nanoribbon, but with slight difference from the individual component. New opportunities of designing nanoelectric devices are discussed by utilizing the quantum confinement effect based on such kind of hybrid nanostructures.

  14. High Performance Ultraviolet Photodetector Fabricated with ZnO Nanoparticles-graphene Hybrid Structures

    Institute of Scientific and Technical Information of China (English)

    Jin-yang Liu; Xin-xin Yu; Guang-hui Zhang; Yu-kun Wu; Kun Zhang; Nan Pan; Xiao-ping Wang

    2013-01-01

    Ultraviolet (UV) photodetector constructed by ZnO material has attracted intense research and commercial interest.However,its photoresistivity and photoresonse are still unsatisfied.Herein,we report a novel method to assemble ZnO nanoparticles (NPs) onto the reduced graphite oxide (RGO) sheet by simple hydrothermal process without any surfactant.It is found that the high-quality crystallized ZnO NPs with the average diameter of 5 nm are well dispersed on the RGO surface,and the density of ZnO NPs can be readily controlled by the concentration of the precursor.The photodetector fabricated with this ZnO NPs-RGO hybrid structure demonstrates an excellent photoresponse for the UV irradiation.The results make this hybrid especially suitable as a novel material for the design and fabrication of high performance UV photodector.

  15. A hybrid approach to analyse a beam-soil structure under a moving random load

    Science.gov (United States)

    Si, L. T.; Zhao, Y.; Zhang, Y. H.; Kennedy, D.

    2016-11-01

    To study the stochastic response of a beam-soil structure under a moving random load, a hybrid approach based on the pseudo-excitation method and the wavelet method is proposed. Using the pseudo-excitation method, the non-stationary random vibration analysis is transformed into a conventional moving harmonic load problem. Analytical solutions of the power spectral density and standard deviation of vertical displacement are derived in an integral form. However, the integrand is singular and highly oscillatory, and the computational time is an important consideration because a large number of frequency points must be computed. To calculate the response accurately and efficiently, a wavelet approach is introduced. Numerical results show that the frequency band which brings the most significant response is dependent on the load velocity. The hybrid method provides a useful tool to estimate the ground vibration caused by traffic loads.

  16. A flexible and transparent graphene/ZnO nanorod hybrid structure fabricated by exfoliating a graphite substrate.

    Science.gov (United States)

    Nam, Gwang-Hee; Baek, Seong-Ho; Cho, Chang-Hee; Park, Il-Kyu

    2014-10-21

    We demonstrate the fabrication of a graphene/ZnO nanorod (NR) hybrid structure by mechanical exfoliation of ZnO NRs grown on a graphite substrate. We confirmed the existence of graphene sheets on the hybrid structure by analyzing the Raman spectra and current-voltage (I-V) characteristics. The Raman spectra of the exfoliated graphene/ZnO NR hybrid structure show G and 2D band peaks that are shifted to lower wavenumbers, indicating that the exfoliated graphene layer exists under a significant amount of strain. The I-V characteristics of the graphene/ZnO NR hybrid structure show current flow through the graphene layer, while no current flow is observed on the ZnO NR/polydimethylsiloxane (PDMS) composite without graphene, thereby indicating that the few-layer graphene was successfully transferred onto the hybrid structure. A piezoelectric nanogenerator is demonstrated by using the fabricated graphene/ZnO NR hybrid structure. The nanogenerator exhibits stable output voltage up to 3.04 V with alternating current output characteristics.

  17. Scan rate effect of titania for hybrid solar cell applications: Structural and electrical study

    Science.gov (United States)

    Khamsan, Muhammad Emmer Ashraf; Ghazali, Mohd Sabri Mohd; Salleh, Hasiah; Zakaria, Azmi; Ghazali, Salmah Mohd; Ahmad, Zakiyah; Aziz, M. S.

    2017-03-01

    The AIP In this research, hybrid solar cell are produce by a combination of organic (Areca Catechu) extraction and Poly (3-hexylthiophene) (P3HT) and inorganic Titanium Dioxide, TiO2 materials. These hybrid solar cells are fabricated accordingly by layered of ITO/TiO2/P3HT/Areca Catechu/Au by using electrochemical method. The deposition of each layered by EIS was different by varied the scan rate of TiO2 deposition which are 0.05, 0.07, 0.09 and 0.11 vs-1 whereas the number of scans of each layers are fixed to 5 numbers of scans. Nanocrystals TiO2 (anatase structured) was prepared by dissolving the TiO2 nanoparticles with acetic acid which acts as capping agent in order to gain TiO2 nanostructures with better-controlled size and shape. Field Emission Scanning Electron Microscope (FESEM) images indicates that the TiO2 nanoparticles size was found to be around 15-34 nm. The XRD patterns indicate that the TiO2 film was highly crystalline and the anatase structure of TiO2 remains unchanged after annealed process took place at 450 °C. Sheet resistivity of the ITO/TiO2/P3HT/Areca Catechu/Au hybrid solar cell are measured in the dark and under different light intensity by using four point probes and power conversion efficiency are measured by using two point probes. In conclusion, the ITO/TiO2/P3HT/Areca Catechu/Au hybrid solar cell with 0.07 v s-1 scan rate produced the highest electrical conductivity and efficiency with 0.278 Scm-1 and 0.021 % respectively.

  18. Joining of Metal-Plastics-Hybrid Structures Using Laser Radiation by Considering the Surface Structure of the Metal

    Directory of Open Access Journals (Sweden)

    Christian Hopmann

    2016-01-01

    Full Text Available Lightweight construction is a central technology in today’s industrial production. One way to achieve the climate goals is the production of hybrid compounds of metal and plastic. The manufacturing process for these hybrid parts can be divided into in-mold assembly and postmold assembly. The postmold assembly includes thermal joining by laser, which is applied in the context of this paper. For the investigations, four plastics (MABS, PA6.6-GF35, PP, and PC, which differ in their properties, and three metals (unalloyed steel, stainless steel, and aluminum are combined and analyzed. These materials have been used, since they have a huge significance in the automotive industry. Preliminary studies showed that an adhesive bond between the two materials is achieved using metal with a structured surface. According to these studies, three structuring processes for metals (selective laser melting (SLM, NRX, and a welded metallic tissue are tested. The quality of the material/structure combinations is tested in tensile-shear-tests, microscopy images, and alternating climate tests. Compounds with SLM-Structure achieve highest strength, while compounds with aluminum are much more complex to manufacture.

  19. Hemolysin coregulated protein 1 as a molecular gluing unit for the assembly of nanoparticle hybrid structures

    Directory of Open Access Journals (Sweden)

    Tuan Anh Pham

    2016-03-01

    Full Text Available Hybrid nanoparticle (NP structures containing organic building units such as polymers, peptides, DNA and proteins have great potential in biosensor and electronic applications. The nearly free modification of the polymer chain, the variation of the protein and DNA sequence and the implementation of functional moieties provide a great platform to create inorganic structures of different morphology, resulting in different optical and magnetic properties. Nevertheless, the design and modification of a protein structure with functional groups or sequences for the assembly of biohybrid materials is not trivial. This is mainly due to the sensitivity of its secondary, tertiary and quaternary structure to the changes in the interaction (e.g., hydrophobic, hydrophilic, electrostatic, chemical groups between the protein subunits and the inorganic material. Here, we use hemolysin coregulated protein 1 (Hcp1 from Pseudomonas aeruginosa as a building and gluing unit for the formation of biohybrid structures by implementing cysteine anchoring points at defined positions on the protein rim (Hcp1_cys3. We successfully apply the Hcp1_cys3 gluing unit for the assembly of often linear, hybrid structures of plasmonic gold (Au NP, magnetite (Fe3O4 NP, and cobalt ferrite nanoparticles (CoFe2O4 NP. Furthermore, the assembly of Au NPs into linear structures using Hcp1_cys3 is investigated by UV–vis spectroscopy, TEM and cryo-TEM. One key parameter for the formation of Au NP assembly is the specific ionic strength in the mixture. The resulting network-like structure of Au NPs is characterized by Raman spectroscopy, showing surface-enhanced Raman scattering (SERS by a factor of 8·104 and a stable secondary structure of the Hcp1_cys3 unit. In order to prove the catalytic performance of the gold hybrid structures, they are used as a catalyst in the reduction reaction of 4-nitrophenol showing similar catalytic activity as the pure Au NPs. To further extend the

  20. Hybrid Structure of the Type 1 Pilus of Uropathogenic Escherichia coli.

    Science.gov (United States)

    Habenstein, Birgit; Loquet, Antoine; Hwang, Songhwan; Giller, Karin; Vasa, Suresh Kumar; Becker, Stefan; Habeck, Michael; Lange, Adam

    2015-09-28

    Type 1 pili are filamentous protein assemblies on the surface of Gram-negative bacteria that mediate adhesion to host cells during the infection process. The molecular structure of type 1 pili remains elusive on the atomic scale owing to their insolubility and noncrystallinity. Herein we describe an approach for hybrid-structure determination that is based on data from solution-state NMR spectroscopy on the soluble subunit and solid-state NMR spectroscopy and STEM data on the assembled pilus. Our approach is based on iterative modeling driven by structural information extracted from different sources and provides a general tool to access pseudo atomic structures of protein assemblies with complex subunit folds. By using this methodology, we determined the local conformation of the FimA pilus subunit in the context of the assembled type 1 pilus, determined the exact helical pilus architecture, and elucidated the intermolecular interfaces contributing to pilus assembly and stability with atomic detail.

  1. A hybrid structure for the storage and manipulation of very large spatial data sets

    Science.gov (United States)

    Peuquet, Donna J.

    1982-01-01

    The map data input and output problem for geographic information systems is rapidly diminishing with the increasing availability of mass digitizing, direct spatial data capture and graphics hardware based on raster technology. Although a large number of efficient raster-based algorithms exist for performing a wide variety of common tasks on these data, there are a number of procedures which are more efficiently performed in vector mode or for which raster mode equivalents of current vector-based techniques have not yet been developed. This paper presents a hybrid spatial data structure, named the ?vaster' structure, which can utilize the advantages of both raster and vector structures while potentially eliminating, or greatly reducing, the need for raster-to-vector and vector-to-raster conversion. Other advantages of the vaster structure are also discussed.

  2. Residual stress and electromagnetic characteristics in loop type frequency selective surface embedded hybrid structures

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kyung Mi; Seo, Yun Seok; Chun, Heoung Jae [Yonsei University, Seoul (Korea, Republic of); Hong, Ik Pyo [Kongju National University, Cheonan (Korea, Republic of); Park, Yong Bae [Ajoo University, Suwon (Korea, Republic of); Kim, Yoon Jae [Agency for defense development, Daejeon (Korea, Republic of)

    2015-01-15

    Residual stresses occur in frequency-selective surface (FSS)-embedded composite structures after co-curing due to differences between the coefficients of thermal expansion between composite skins and FSSs. Furthermore, the electromagnetic characteristics may be affected by the deformation of the FSS pattern by residual stresses. Therefore, we studied the changes in electromagnetic characteristics due to the deformation of FSS, using residual stresses to deform loop-type FSS-embedded hybrid composites. We considered the effects of loop-type FSS patterns of equal dimension as well as the stacking sequences of composite laminates on the electromagnetic characteristics of FSSs: Square loop, triangular loop and circular loop. The stacking sequences of composite laminates considered in this study were [0]{sub 8}, [0/90]{sub 4}, [+-45]{sub 4} and [0/+-45/90]{sub 2}. The FSS was located between composite laminates in the middle plane. To determine the residual stresses and deformations in the FSS embedded laminate structures, the thermal loading condition in the finite element analysis was induced by cooling the hybrid structures from 125 .deg. C to 20 .deg. C based on the cure cycle of the composite. Also, the electromagnetic reflection characteristics of the hybrid structures were predicted using deformed models by residual stresses, considering the effects of stacking sequence of composite laminates. The results showed that the maximum residual stresses and deformations were produced in the [0]{sub 8} composites with all three loop-types of FSS pattern. However, the maximum resonance frequency shifts occurred in the square and triangle loop-types with stacking sequence of [0]{sub 8} , while the maximum resonance frequency shift occurred in the circular loop-type with stacking sequence of [0/+-45/90]{sub 2}.

  3. Morphology dependent two photon absorption in plasmonic structures and plasmonic-organic hybrids

    Science.gov (United States)

    Gambhir, Kaweri; Ray, Bhumika; Mehrotra, Ranjana; Sharma, Parag

    2017-05-01

    Two photon absorption coefficients of two distinct plasmonic structures, namely, gold nanoflowers (GNF) and gold nanopebbles (GNP) have been investigated and compared with conventional gold nanospheres (GNS). All three different nanoshapes were synthesized by changing the reaction solvent under the same experimental procedure. Further, hybrids of these plasmonic structures were prepared with an organic dye Eosin yellow (EY), to investigate the morphology effect of plasmonic structures on plasmonic-organic hybrids in terms of their linear extinction spectra and two photon absorption coefficients. The NLO investigations were conducted using 20 ps laser pulses of wavelength 532 nm as an excitation source in single beam Z-scan setup. UV/visible spectroscopy was employed for monitoring plasmon resonances and changes in linear extinction spectra. The experimental outcomes revealed two photon absorption coefficients of EY increased 120%, 32% and 39%, while 69%, 60% and 53% enhancement in the peaks of linear extinction maxima of EY has been observed, when hybridized with GNF, GNS and GNP, respectively. This boost in the optical coefficients may be attributed to dimerization of EY molecules on the surface of nanoparticles. Keeping the toxicity of EY in view, we propose that the two photon absorption coefficients of this dye and control thereof, by the addition of plasmonic structures would be helpful not only in understanding the interactions between plasmons and fluorophore, but also pave an efficient way, to reduce the operative concentration of this hazardous dye in a wide range of applications and thereby, mitigating the environmental degradation caused by its highly concentrated effluents.

  4. Interface engineering in inorganic hybrid structures towards improved photocatalysis (Conference Presentation)

    Science.gov (United States)

    Xiong, Yujie

    2016-10-01

    Designing new photocatalytic materials for improving photoconversion efficiency is a promising route to alleviate the steadily worsening environmental issues and energy crisis. Despite the invention of a large number of catalytic materials with well-defined structures, their overall efficiency in photocatalysis is still quite limited as the three key steps - light harvesting, charge generation and separation, and charge transfer to surface for redox reactions - have not been substantially improved. To improve each step in the complex process, there is a major trend to develop materials based on inorganic hybrid structures. In this case, interface engineering holds the promise for boosting the overall efficiency, given the key roles of interface structures in charge and energy transfer. In this talk, I will demonstrate several different approaches to designing inorganic hybrid structures with improved photocatalytic performance via interface engineering. The typical demonstrations include semiconductor-plasmonics systems for broad-spectrum light harvesting, metal-semiconductor interfaces for improved charge separation, semiconductor-MOF (metal-organic framework) configurations for activated surface reactions. It is anticipated that this series of works open a new window to rationally designing inorganic hybrid materials for photo-induced applications. References: (1) Bai, S.; Yang, L.; Wang, C.; Lin, Y.; Lu, J.; Jiang, J. and Xiong, Y.*, Angew. Chem. Int. Ed. 54, 14810-14814 (2015). (2) Bai, S.; Jiang, J.; Zhang, Q. and Xiong, Y.*, Chem. Soc. Rev. 44, 2893-2939 (2015). (3) Bai, S.; Li, X.; Kong, Q.; Long, R.; Wang, C.; Jiang, J. and Xiong, Y.*, Adv. Mater. 27, 3444-3452 (2015). (4) Bai, S.; Ge, J.; Wang, L.; Gong, M.; Deng, M.; Kong, Q.; Song, L.; Jiang, J.;* Zhang, Q.;* Luo, Y.; Xie, Y. and Xiong, Y.*, Adv. Mater. 26, 5689-5695 (2014). (5) Li, R.; Hu, J.; Deng, M.; Wang, H.; Wang, X.; Hu, Y.; Jiang, H. L.; Jiang, J.;* Zhang, Q.;* Xie, Y. and Xiong, Y.*, Adv. Mater

  5. On hydrophilicity improvement of the porous anodic alumina film by hybrid nano/micro structuring

    Science.gov (United States)

    Wang, Weichao; Zhao, Wei; Wang, Kaige; Wang, Lei; Wang, Xuewen; Wang, Shuang; Zhang, Chen; Bai, Jintao

    2017-09-01

    In both, laboratory and industry, tremendous attention is paid to discover an effective technique to produce uniform, controllable and (super) hydrophilic surfaces over large areas that are useful in a wide range of applications. In this investigation, by combing porous anodic alumina (PAA) film with nano-structures and microarray of aluminum, the hydrophilicity of hybrid nano-micro structure has been significantly improved. It is found some factors can affect the hydrophilicity of film, such as the size and aspect ratio of microarray, the thickness of nano-PAA film etc. Comparing with pure nano-PAA films and microarray, the hybrid nano-micro structure can provide uniform surface with significantly better hydrophilicity. The improvement can be up to 84%. Also, this technique exhibits good stability and repeatability for industrial production. By optimizing the thickness of nano-PAA film and aspect ratio of micro-structures, super-hydrophilicity can be reached. This study has obvious prospect in the fields of chemical industry, biomedical engineering and lab-on-a-chip applications.

  6. Fabrication of Nano-Micro Hybrid Structures by Replication and Surface Treatment of Nanowires

    Directory of Open Access Journals (Sweden)

    Yeonho Jeong

    2017-07-01

    Full Text Available Nanowire structures have attracted attention in various fields, since new characteristics could be acquired in minute regions. Especially, Anodic Aluminum Oxide (AAO is widely used in the fabrication of nanostructures, which has many nanosized pores and well-organized nano pattern. Using AAO as a template for replication, nanowires with a very high aspect ratio can be fabricated. Herein, we propose a facile method to fabricate a nano-micro hybrid structure using nanowires replicated from AAO, and surface treatment. A polymer resin was coated between Polyethylene terephthalate (PET and the AAO filter, roller pressed, and UV-cured. After the removal of aluminum by using NaOH solution, the nanowires aggregated to form a micropattern. The resulting structure was subjected to various surface treatments to investigate the surface behavior and wettability. As opposed to reported data, UV-ozone treatment can enhance surface hydrophobicity because the UV energy affects the nanowire surface, thus altering the shape of the aggregated nanowires. The hydrophobicity of the surface could be further improved by octadecyltrichlorosilane (OTS coating immediately after UV-ozone treatment. We thus demonstrated that the nano-micro hybrid structure could be formed in the middle of nanowire replication, and then, the shape and surface characteristics could be controlled by surface treatment.

  7. Electronic structure modeling of InAs/GaSb superlattices with hybrid density functional theory

    Science.gov (United States)

    Garwood, T.; Modine, N. A.; Krishna, S.

    2017-03-01

    The application of first-principles calculations holds promise for greatly improving our understanding of semiconductor superlattices. Developing a procedure to accurately predict band gaps using hybrid density functional theory lays the groundwork for future studies investigating more nuanced properties of these structures. Our approach allows a priori prediction of the properties of SLS structures using only the band gaps of the constituent materials. Furthermore, it should enable direct investigation of the effects of interface structure, e.g., intermixing or ordering at the interface, on SLS properties. In this paper, we present band gap data for various InAs/GaSb type-II superlattice structures calculated using the generalized Kohn-Sham formulation of density functional theory. A PBE0-type hybrid functional was used, and the portion of the exact exchange was tuned to fit the band gaps of the binary compounds InAs and GaSb with the best agreement to bulk experimental values obtained with 18% of the exact exchange. The heterostructures considered in this study are 6 monolayer (ML) InAs/6 ML GaSb, 8 ML InAs/8 ML GaSb and 10 ML InAs/10 ML GaSb with deviations from the experimental band gaps ranging from 3% to 11%.

  8. Structure-Band Gap Relationships in Hexagonal Polytypes and Low-Dimensional Structures of Hybrid Tin Iodide Perovskites.

    Science.gov (United States)

    Stoumpos, Constantinos C; Mao, Lingling; Malliakas, Christos D; Kanatzidis, Mercouri G

    2017-01-03

    The present study deals with the structural characterization and classification of the novel compounds 1-8 into perovskite subclasses and proceeds in extracting the structure-band gap relationships between them. The compounds were obtained from the employment of small, 3-5-atom-wide organic ammonium ions seeking to discover new perovskite-like compounds. The compounds reported here adopt unique or rare structure types akin to the prototype structure perovskite. When trimethylammonium (TMA) was employed, we obtained TMASnI3 (1), which is our reference compound for a "perovskitoid" structure of face-sharing octahedra. The compounds EASnI3 (2b), GASnI3 (3a), ACASnI3 (4), and IMSnI3 (5) obtained from the use of ethylammonium (EA), guanidinium (GA), acetamidinium (ACA), and imidazolium (IM) cations, respectively, represent the first entries of the so-called "hexagonal perovskite polytypes" in the hybrid halide perovskite library. The hexagonal perovskites define a new family of hybrid halide perovskites with a crystal structure that emerges from a blend of corner- and face-sharing octahedral connections in various proportions. The small organic cations can also stabilize a second structural type characterized by a crystal lattice with reduced dimensionality. These compounds include the two-dimensional (2D) perovskites GA2SnI4 (3b) and IPA3Sn2I7 (6b) and the one-dimensional (1D) perovskite IPA3SnI5 (6a). The known 2D perovskite BA2MASn2I7 (7) and the related all-inorganic 1D perovskite "RbSnF2I" (8) have also been synthesized. All compounds have been identified as medium-to-wide-band-gap semiconductors in the range of Eg = 1.90-2.40 eV, with the band gap progressively decreasing with increased corner-sharing functionality and increased torsion angle in the octahedral connectivity.

  9. Dust Acoustic Solitary Waves in Saturn F-ring's Region

    Institute of Scientific and Technical Information of China (English)

    E.K. El-Shewy; M.I. Abo el Maaty; H.G. Abdelwahed; M.A.Elmessary

    2011-01-01

    Effect of hot and cold dust charge on the propagation of dust-acoustic waves (DAWs) in unmagnetized plasma having electrons, singly charged ions, hot and cold dust grains has been investigated.The reductive perturbation method is employed to reduce the basic set of fluid equations to the Kortewege-de Vries (KdV) equation.At the critical hot dusty plasma density NhO, the KdV equation is not appropriate for describing the system.Hence, a set of stretched coordinates is considered to derive the modified KdV equation.It is found that the presence of hot and cold dust charge grains not only significantly modifies the basic properties of solitary structure, but also changes the polarity of the solitary profiles.In the vicinity of the critical hot dusty plasma density NhO, neither KdV nor mKdV equation is appropriate for describing the DAWs.Therefore, a further modified KdV (fmKdV) equation is derived, which admits both soliton and double layer solutions.

  10. Measurement of Ultra-Short Solitary Electromagnetic Pulses

    Directory of Open Access Journals (Sweden)

    Eva Gescheidtova

    2004-01-01

    Full Text Available In connection with the events of the last few years and with the increased number of terrorist activities, the problem of identification and measurement of electromagnetic weapons or other systems impact occurred. Among these are also microwave sources, which can reach extensive peak power of up to Pmax = 100 MW. Solitary, in some cases several times repeated, impulses lasting from tp E <1, 60>ns, cause the destruction of semiconductor junctions. These days we can find scarcely no human activity, where semiconductor structures are not used. The problem of security support of the air traffic, transportation, computer nets, banks, national strategic data canter’s, and other applications crops up. Several types of system protection from the ultra-short electromagnetic pulses present itself, passive and active protection. The analysis of the possible measuring methods, convenient for the identification and measurement of the ultra-short solitary electromagnetic pulses in presented in this paper; some of the methods were chosen and used for practical measurement. This work is part of Research object MSM262200022 "Research of microelectronic systems".

  11. Characterization of the structural and protein recognition properties of hybrid PNA-DNA four-way junctions.

    Science.gov (United States)

    Iverson, Douglas; Serrano, Crystal; Brahan, Ann Marie; Shams, Arik; Totsingan, Filbert; Bell, Anthony J

    2015-12-01

    The objective of this study is to evaluate the structure and protein recognition properties of hybrid four-way junctions (4WJs) composed of DNA and peptide nucleic acid (PNA) strands. We compare a classic immobile DNA junction, J1, vs. six PNA-DNA junctions, including a number with blunt DNA ends and multiple PNA strands. Circular dichroism (CD) analysis reveals that hybrid 4WJs are composed of helices that possess structures intermediate between A- and B-form DNA, the apparent level of A-form structure correlates with the PNA content. The structure of hybrids that contain one PNA strand is sensitive to Mg(+2). For these constructs, the apparent B-form structure and conformational stability (Tm) increase in high Mg(+2). The blunt-ended junction, b4WJ-PNA3, possesses the highest B-form CD signals and Tm (40.1 °C) values vs. all hybrids and J1. Protein recognition studies are carried out using the recombinant DNA-binding protein, HMGB1b. HMGB1b binds the blunt ended single-PNA hybrids, b4WJ-PNA1 and b4WJ-PNA3, with high affinity. HMGB1b binds the multi-PNA hybrids, 4WJ-PNA1,3 and b4WJ-PNA1,3, but does not form stable protein-nucleic acid complexes. Protein interactions with hybrid 4WJs are influenced by the ratio of A- to B-form helices: hybrids with helices composed of higher levels of B-form structure preferentially associate with HMGB1b.

  12. Gold conjugate-based liposomes with hybrid cluster bomb structure for liver cancer therapy.

    Science.gov (United States)

    Zhang, Ning; Chen, Huan; Liu, Ai-Yun; Shen, Jia-Jia; Shah, Vishva; Zhang, Can; Hong, Jin; Ding, Ya

    2016-01-01

    Hybrid drug delivery system containing both organic and inorganic nanocarriers is expected to achieve its complementary advantages for the aim of improving the performance of antineoplastic drugs in tumor therapy. Here we report the use of liposomes and gold nanoparticles to construct a liposome with a hybrid Cluster Bomb structure and discuss its unique multi-order drug release property for liver tumor treatment. A very simple method is used for the hybrid liposome preparation and involves mixing two solutions containing liposomes loaded with either non-covalent or covalent Paclitaxel (PTX, namely free PTX or PTX-conjugated GNPs, respectively) by different ratio of volume (25:75, 50:50, 25:75, v/v). Various mixed liposomes were tested to determine the optimal conditions for maximum drug delivery. The optimized liposome was then tested using xenograft Heps tumor-bearing mice and showed the best efficacy for chemotherapeutic inhibition of tumor at PTX liposome: PTX-conjugated GNP liposome of 25:75 ratio (v/v). This system allows for simple and easy preparation while providing a more accurate site- and time-release mode for tumor treatment using antitumor drugs.

  13. Charge Neutral Fermionic States and Current Oscillation in a Graphene-Superconductor Hybrid Structure

    Science.gov (United States)

    Duan, Wenye; Wang, Wei; Zhang, Chao; Jin, Kuijuan; Ma, Zhongshui

    2016-10-01

    The proximity properties of edge currents in the vicinity of the interface between the graphene and superconductor in the presence of magnetic field are investigated. It is shown that the edge states introduced by Andreev reflection at the graphene-superconductor (G/S) interface give rise to the charge neutral states in all Landau levels. We note that in a topological insulator-superconductor (TI/S) hybrid structure, only N = 0 Landau level can support this type of charge neutral states. The different interface states of a G/S hybrid and a TI/S hybrid is due to that graphene consists of two distinct sublattices. The armchair edge consists of two inequivalent atoms. This gives rise to unique electronic properties of edge states when connected to a superconductor. A direct consequence of zero charge states in all Landau levels is that the current density approaches zero at interface. The proximity effect leads to quantum magnetic oscillation of the current density in the superconductor region. The interface current density can also be tuned with a finite interface potential. For sharp δ-type interface potential, the derivative of the wavefunction is discontinuous. As a result, we found that there is current density discontinuity at the interface. The step of the current discontinuity is proportional to the strength of the interface potential.

  14. Convection Destroys the Core/Mantle Structure in Hybrid C/O/Ne White Dwarfs

    CERN Document Server

    Brooks, Jared; Bildsten, Lars; Quataert, Eliot; Paxton, Bill

    2016-01-01

    A hybrid C/O/Ne white dwarf (WD) -- an unburned C/O core surrounded by an O/Ne/Na mantle -- can be formed if the carbon flame is quenched in a super-AGB (SAGB) star or white dwarf merger remnant. We show that this segregated hybrid structure becomes unstable to rapid mixing within 2,000 years of the onset of WD cooling. Carbon burning includes a weak reaction that removes electrons, resulting in a lower electron-to-baryon ratio ($Y_{\\rm e}$) in the regions processed by carbon burning compared to the unburned C/O core, making the O/Ne mantle denser than the C/O core as the WD cools. This is unstable to efficient mixing. We use the results of $\\texttt{MESA}$ models with different size C/O cores to quantify the rate at which the cores mix with the mantle as they cool. In all cases, we find that the WDs undergo significant core/mantle mixing on timescales shorter than the time available to grow the WD to the Chandrasekhar mass ($M_{\\rm Ch}$) by accretion. As a result, hybrid WDs that reach $M_{\\rm Ch}$ due to lat...

  15. Hybrid Numerical Solvers for Massively Parallel Eigenvalue Computation and Their Benchmark with Electronic Structure Calculations

    CERN Document Server

    Imachi, Hiroto

    2015-01-01

    Optimally hybrid numerical solvers were constructed for massively parallel generalized eigenvalue problem (GEP).The strong scaling benchmark was carried out on the K computer and other supercomputers for electronic structure calculation problems in the matrix sizes of M = 10^4-10^6 with upto 105 cores. The procedure of GEP is decomposed into the two subprocedures of the reducer to the standard eigenvalue problem (SEP) and the solver of SEP. A hybrid solver is constructed, when a routine is chosen for each subprocedure from the three parallel solver libraries of ScaLAPACK, ELPA and EigenExa. The hybrid solvers with the two newer libraries, ELPA and EigenExa, give better benchmark results than the conventional ScaLAPACK library. The detailed analysis on the results implies that the reducer can be a bottleneck in next-generation (exa-scale) supercomputers, which indicates the guidance for future research. The code was developed as a middleware and a mini-application and will appear online.

  16. Low temperature hydrogen sensing using reduced graphene oxide and tin oxide nanoflowers based hybrid structure

    Science.gov (United States)

    Venkatesan, A.; Rathi, Servin; Lee, In-Yeal; Park, Jinwoo; Lim, Dongsuk; Kim, Gil-Ho; Kannan, E. S.

    2016-12-01

    In this paper, we have demonstrated a low temperature hydrogen (H2) sensor based on reduced graphene oxide (rGO) and tin oxide nanoflowers (SnO2 NFs) hybrid composite film. The addition of SnO2 NFs into rGO solution inhibits irreversible restacking and agglomeration of rGO and increases the active surface area for interaction with H2. This rGO-SnO2 NFs hybrid film sensor showed an excellent response to H2 at 60 °C at 200 ppm with an improvement of 126% compared to pure rGO which was used as a control sample. The sensor also showed good response and recovery time in comparison to pure rGO film. The highly improved H2 sensing characteristics of rGO-SnO2 NFs hybrid are due to its (a) unique structural geometry that increased the surface area for H2 adsorption, and (b) change in the width of depletion layer at the interface due to H2 interaction.

  17. Damping characteristics of active-passive hybrid constrained-layer treated beam structures

    Science.gov (United States)

    Liu, Yanning; Wang, Kon-Well

    2000-04-01

    A new configuration of surface damping treatments, Active- Passive Hybrid Constrained Layer (HCL) damping, is analyzed and experimentally investigated. The purpose is to improve the performance of the current active constrained layer (ACL) and passive constrained layer (PCL) treatments by mixing passive and active materials in the constraining layer. In HCL, the viscoelastic material is constrained by an active-passive hybrid constraining layer -- the active part is made of PZT ceramics, and the passive part can be selected by the designer to meet different requirements, such as higher damping performance or lighter weight. The active and passive constraining parts are mechanically connected such that the displacement and force are continuous at the connecting surface, but are isolated electrically so the passive constraining part will not affect the function of its active counterpart. Following a generic study of the HCL concept by the authors earlier, the purpose of this paper is to illustrate and validate the HCL performance through both numerical and experimental investigations on a beam structure. The governing equations and boundary conditions of an HCL treated beam are derived and a finite element model is formulated. Tabletop tests with cantilever beam specimens are used for the experimental study. The new hybrid constrained layer is found to have the advantages of both ACL and PCL. By selecting a stiffer passive constraining material and an optimal active-to-passive length ratio, the HCL can achieve better closed-loop and open-loop performances than the treatment with a pure active constraining layer.

  18. On the solitary wave paradigm for tsunamis

    DEFF Research Database (Denmark)

    Madsen, Per A.; Fuhrman, David R.; Schäffer, Hemming Andreas

    2008-01-01

    Since the 1970s, solitary waves have commonly been used to model tsunamis especially in experimental and mathematical studies. Unfortunately, the link to geophysical scales is not well established, and in this work we question the geophysical relevance of this paradigm. In part 1, we simulate...... of finite amplitude solitary wave theory in laboratory studies of tsunamis. We conclude that order-of-magnitude errors in effective temporal and spatial duration occur when this theory is used as an approximation for long waves on a sloping bottom. In part 3, we investigate the phenomenon of disintegration...... of long waves into shorter waves, which has been observed e.g. in connection with the Indian Ocean tsunami in 2004. This happens if the front of the tsunami becomes sufficently steep, and as a result the front turns into an undular bore. We discuss the importance of these very short waves in connection...

  19. A Solitary Plasmocytoma Case Causing Horner Syndrome

    Directory of Open Access Journals (Sweden)

    Mustafa Vayvada

    2014-08-01

    Full Text Available Solitary plasmacytoma is a rare plasma cell tumour, when seen in the chest wall, it is important to diagnose since the treatment scheme and prognosis will vary, compared to primary malignant tumours of the chest wall. A 60-year-old male presented to our clinic with left shoulder pain radiating to the left axilla. Horner%u2019s syndrome symptoms were present, in further examination a chest wall mass located in the left upper lung lobe region was detected. Histopathologic diagnosis was solitary plasmocytoma via video-assisted thoracoscopy. The primary tumor of the rib malignancy causing Horner%u2019s syndrome is discussed with reference to the relevant literature.

  20. Hypokalemia associated with a solitary pulmonary nodule

    Science.gov (United States)

    Saeian, Samira; Ghayumi, Seiyed Mohammad Ali; Shams, Mesbah

    2016-01-01

    Abstract Background: Differential diagnosis of hypokalemia and adrenocorticotropic hormone (ACTH)-dependent Cushing's syndrome often presents challenging in endocrinology and requires careful clinical, biochemical, radiological, and pathological investigations. Hypokalemia is a common abnormality and systematic approach is required to avoid delays in diagnosis of important underlying causes. Case Summary: A 49-year-old woman presented with moderate hypokalemia. Further evaluation showed hypercortisolism due to ectopic ACTH secretion. Chest computed tomography (CT) revealed a peripheral solitary pulmonary nodule. Excision biopsy of the nodule showed carcinoid tumor. After excision biopsy, all of the patient's symptoms improved and electrolytes and ACTH levels also became normal. Conclusion: Carciniod tumors should be considered as a differential diagnosis in patients presenting with hypokalemia and ectopic ACTH syndrome. Carcinoid tumor often present as solitary pulmonary nodule and excision biopsy can be curative. PMID:27977570

  1. Asymptotic Linear Stability of Solitary Water Waves

    Science.gov (United States)

    Pego, Robert L.; Sun, Shu-Ming

    2016-12-01

    We prove an asymptotic stability result for the water wave equations linearized around small solitary waves. The equations we consider govern irrotational flow of a fluid with constant density bounded below by a rigid horizontal bottom and above by a free surface under the influence of gravity neglecting surface tension. For sufficiently small amplitude waves, with waveform well-approximated by the well-known sech-squared shape of the KdV soliton, solutions of the linearized equations decay at an exponential rate in an energy norm with exponential weight translated with the wave profile. This holds for all solutions with no component in (that is, symplectically orthogonal to) the two-dimensional neutral-mode space arising from infinitesimal translational and wave-speed variation of solitary waves. We also obtain spectral stability in an unweighted energy norm.

  2. Partial Differential Equations and Solitary Waves Theory

    CERN Document Server

    Wazwaz, Abdul-Majid

    2009-01-01

    "Partial Differential Equations and Solitary Waves Theory" is a self-contained book divided into two parts: Part I is a coherent survey bringing together newly developed methods for solving PDEs. While some traditional techniques are presented, this part does not require thorough understanding of abstract theories or compact concepts. Well-selected worked examples and exercises shall guide the reader through the text. Part II provides an extensive exposition of the solitary waves theory. This part handles nonlinear evolution equations by methods such as Hirota’s bilinear method or the tanh-coth method. A self-contained treatment is presented to discuss complete integrability of a wide class of nonlinear equations. This part presents in an accessible manner a systematic presentation of solitons, multi-soliton solutions, kinks, peakons, cuspons, and compactons. While the whole book can be used as a text for advanced undergraduate and graduate students in applied mathematics, physics and engineering, Part II w...

  3. [Solitary fibrous tumours of the kidney].

    Science.gov (United States)

    Gres, Pascal; Avances, Christophe; Ben Naoum, Kamel; Chapuis, Héliette; Costa, Pierre

    2004-02-01

    Solitary fibrous tumours (SFT) are mesenchymal tumours that usually arise from the pleura. Renal SFT are exceptional (9 cases reported in the literature). The authors report a new case discovered during assessment of HT and treated by radical right nephrectomy. The histological appearance is characteristic: a tumour with a fibrous centre, composed of a monomorphic proliferation of spindle cells, with positive CD 34, CD 99, and bcl 2 labelling. The prognosis after complete resection is generally favourable.

  4. Solitary vascular malformation of the clitoris.

    Science.gov (United States)

    Haritharan, T; Islah, M; Zulfiqar, A; Thambi Dorai, C R

    2006-06-01

    Isolated involvement of the clitoris by vascular malformation (VM) is very rare. Clinically, the lesion simulates female pseudohermaphroditism. A five-year-old girl presented with clitoromegaly and a clinical diagnosis of solitary VM of the clitoris was made. Magnetic resonance imaging showed characteristic features and confirmed the diagnosis and the extent of the VM. This is the first reported case of isolated involvement of the clitoris by VM to be diagnosed preoperatively.

  5. Two-color walking Peregrine solitary waves.

    Science.gov (United States)

    Baronio, Fabio; Chen, Shihua; Mihalache, Dumitru

    2017-09-15

    We study the extreme localization of light, evolving upon a non-zero background, in two-color parametric wave interaction in nonlinear quadratic media. We report the existence of quadratic Peregrine solitary waves, in the presence of significant group-velocity mismatch between the waves (or Poynting vector beam walk-off), in the regime of cascading second-harmonic generation. This finding opens a novel path for the experimental demonstration of extreme rogue waves in ultrafast quadratic nonlinear optics.

  6. Genetic structure, introgression, and a narrow hybrid zone between northern and California spotted owls (Strix occidentalis).

    Science.gov (United States)

    Barrowclough, G F; Groth, J G; Mertz, L A; Gutiérrez, R J

    2005-04-01

    The northern spotted owl (Strix occidentalis caurina) is a threatened subspecies and the California spotted owl (Strix occidentalis occidentalis) is a subspecies of special concern in the western United States. Concern for their continued viability has arisen because of habitat loss caused by timber harvesting. The taxonomic status of the northern subspecies has been the subject of continuing controversy. We investigated the phylogeographical and population genetic structure of northern and California spotted owls with special reference to their region of contact. Mitochondrial DNA (mtDNA) control region sequences confirmed the existence of two well-differentiated lineages connected by a narrow hybrid zone in a region of low population density in north central California. Maximum-likelihood estimates indicated bidirectional gene flow between the lineages but limited introgression outside the region of contact. The lengths of both the mtDNA hybrid zone and the reduced density patch were similar and slightly exceeded estimates of natal dispersal distances. This suggests that the two subspecies were in secondary contact in a hybrid zone trapped by a population density trough. Consequently, the zone of interaction is expected to be geographically stable. We discovered a third, rare clade of haplotypes, which we interpreted to be a result of incomplete lineage sorting; those haplotypes result in a paraphyletic northern spotted owl with respect to the California spotted owl. A congeneric species, the barred owl (Strix varia), occasionally hybridizes with spotted owls; our results indicated an upper bound for the frequency of barred owl mtDNA haplotypes in northern spotted owl populations of 3%.

  7. New hybrid lead iodides: From one-dimensional chain to two-dimensional layered perovskite structure

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Kecai; Liu, Wei [Department of Chemistry and Chemical Biology, Rutgers University, 610 Taylor Road, Piscataway, NJ 08854 (United States); Teat, Simon J. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); An, Litao; Wang, Hao; Emge, Thomas J. [Department of Chemistry and Chemical Biology, Rutgers University, 610 Taylor Road, Piscataway, NJ 08854 (United States); Li, Jing, E-mail: jingli@rutgers.edu [Department of Chemistry and Chemical Biology, Rutgers University, 610 Taylor Road, Piscataway, NJ 08854 (United States)

    2015-10-15

    Two new hybrid lead halides (H{sub 2}BDA)[PbI{sub 4}] (1) (H{sub 2}BDA=1,4-butanediammonium dication) and (HNPEIM)[PbI{sub 3}] (2) (HNPEIM=N-​phenyl-ethanimidamidine cation) have been synthesized and structurally characterized. X-ray diffraction analyses reveal that compound 1 features a two-dimensional corner-sharing perovskite layer whereas compound 2 contains one-dimensional edge-sharing double chains. The N-​phenyl-ethanimidamidine cation within compound 2 was generated in-situ under solvothermal conditions. The optical absorption spectra collected at room temperature suggest that both compounds are semiconductors having direct band gaps, with estimated values of 2.64 and 2.73 eV for 1 and 2, respectively. Results from the density functional theory (DFT) calculations are consistent with the experimental data. Density of states (DOS) analysis reveals that in both compounds 1 and 2, the energy states in the valence band maximum region are iodine 5p atomic orbitals with a small contribution from lead 6s, while in the region of conduction band minimum, the major contributions are from the inorganic (Pb 6p atomic orbitals) and organic components (C and N 2p atomic orbitals) in compound 1 and 2, respectively. - Graphical abstract: Two new hybrid lead halides built on one-dimensional edge-sharing double chains and two-dimensional corner-sharing perovskite layers are synthesized and their structural and electronic properties are analyzed. - Highlights: • Two new hybrid lead iodides are designed, synthesized, and characterized. • They are closely related to, but different from, perovskite structures. • The electronic properties of both compounds are analyzed by DFT calculations.

  8. Directing Hybrid Structures by Combining Self-Assembly of Functional Block Copolymers and Atomic Layer Deposition: A Demonstration on Hybrid Photovoltaics.

    Science.gov (United States)

    Moshonov, Moshe; Frey, Gitti L

    2015-11-24

    The simplicity and versatility of block copolymer self-assembly offers their use as templates for nano- and meso-structured materials. However, in most cases, the material processing requires multiple steps, and the block copolymer is a sacrificial building block. Here, we combine a self-assembled block copolymer template and atomic layer deposition (ALD) of a metal oxide to generate functional hybrid films in a simple process with no etching or burning steps. This approach is demonstrated by using the crystallization-induced self-assembly of a rod-coil block copolymer, P3HT-b-PEO, and the ALD of ZnO. The block copolymer self-assembles into fibrils, ∼ 20 nm in diameter and microns long, with crystalline P3HT cores and amorphous PEO corona. The affinity of the ALD precursors to the PEO corona directs the exclusive deposition of crystalline ZnO within the PEO domains. The obtained hybrid structure possesses the properties desired for photovoltaic films: donor-acceptor continuous nanoscale interpenetrated networks. Therefore, we integrated the films into single-layer hybrid photovoltaics devices, thus demonstrating that combining self-assembly of functional block copolymers and ALD is a simple approach to direct desired complex hybrid morphologies.

  9. Ribbon structure stabilized by C10 and C12 turns in αγ hybrid peptide.

    Science.gov (United States)

    Wani, Naiem Ahmad; Kant, Rajni; Gupta, Vivek Kumar; Aravinda, Subrayashastry; Rai, Rajkishor

    2016-04-01

    The present study describes the synthesis and crystallographic analysis of αγ hybrid peptides, Boc-Gpn-L-Pro-NHMe (1), Boc-Aib-Gpn-L-Pro-NHMe (2), and Boc-L-Pro-Aib-Gpn-L-Pro-NHMe (3). Peptides 1 and 2 adopt expanded 12-membered (C12 ) helical turn over γα segment. Peptide 3 promotes the ribbon structure stabilized by type II β-turn (C10 ) followed by the expanded C12 helical γα turn. Both right-handed and left-handed helical conformations for Aib residue are observed in peptides 2 and 3, respectively.

  10. Flexible solid-state supercapacitors based on carbon nanoparticles/MnO2 nanorods hybrid structure.

    Science.gov (United States)

    Yuan, Longyan; Lu, Xi-Hong; Xiao, Xu; Zhai, Teng; Dai, Junjie; Zhang, Fengchao; Hu, Bin; Wang, Xue; Gong, Li; Chen, Jian; Hu, Chenguo; Tong, Yexiang; Zhou, Jun; Wang, Zhong Lin

    2012-01-24

    A highly flexible solid-state supercapacitor was fabricated through a simple flame synthesis method and electrochemical deposition process based on a carbon nanoparticles/MnO(2) nanorods hybrid structure using polyvinyl alcohol/H(3)PO(4) electrolyte. Carbon fabric is used as a current collector and electrode (mechanical support), leading to a simplified, highly flexible, and lightweight architecture. The device exhibited good electrochemical performance with an energy density of 4.8 Wh/kg at a power density of 14 kW/kg, and a demonstration of a practical device is also presented, highlighting the path for its enormous potential in energy management.

  11. An Ultrahigh-Performance Photodetector based on a Perovskite-Transition-Metal-Dichalcogenide Hybrid Structure.

    Science.gov (United States)

    Kang, Dong-Ho; Pae, Seong Ryul; Shim, Jaewoo; Yoo, Gwangwe; Jeon, Jaeho; Leem, Jung Woo; Yu, Jae Su; Lee, Sungjoo; Shin, Byungha; Park, Jin-Hong

    2016-09-01

    An ultrahigh performance MoS2 photodetector with high photoresponsivity (1.94 × 10(6) A W(-1) ) and detectivity (1.29 × 10(12) Jones) under 520 nm and 4.63 pW laser exposure is demonstrated. This photodetector is based on a methyl-ammonium lead halide perovskite/MoS2 hybrid structure with (3-aminopropyl)triethoxysilane doping. The performance degradation caused by moisture is also minimized down to 20% by adopting a new encapsulation bilayer of octadecyltrichlorosilane/polymethyl methacrylate.

  12. New approaches to the development of hybrid nanocomposites: from structural materials to high-tech applications

    Science.gov (United States)

    Gerasin, V. A.; Antipov, Evgenii M.; Karbushev, V. V.; Kulichikhin, Valerii G.; Karpacheva, Galina P.; Talroze, Raisa V.; Kudryavtsev, Y. V.

    2013-04-01

    Current challenges in the development of various polymer nanocomposites and in the study of their properties are considered. Results of studying hybrid structural (polymer-layered silicates, polymer-nanodiamonds) and functional (based on conducting or liquid-crystalline polymers) nanomaterials are presented. Methods of modification of nanoparticles and their dispersion in a polymer matrix, and the role of interactions between a polymer matrix and fillers, as well as of nanoparticle morphology realized in the course of processing, are discussed. The bibliography includes 453 references.

  13. Photoemission study of ferrocenes: insights into the electronic structure of Si-based hybrid materials

    Energy Technology Data Exchange (ETDEWEB)

    Boccia, A; Marrani, A G; Stranges, S; Zanoni, R [Dipartimento di Chimica, Universita degli Studi di Roma ' La Sapienza' , piazzale Aldo Moro 5, I-00185 Rome (Italy); Alagia, M [ISMN-CNR, Sezione Romal, Piazzale Aldo Moro 5, I-00185 Roma, Italy and Laboratorio Nazionale TASC-CNR SS-14, Km 163.5, Basovizza, I-34012 Trieste (Italy); Iozzi, M F; Cossi, M [Dipartimento di Scienze dell' Ambiente e della Vita, Universita del Piemonte Orientale, via V. Bellini 25/G, I-15100 Alessandria (Italy)], E-mail: Andrea.Marrani@uniromal.it

    2008-03-15

    We present here the results of synchrotron radiation-excited UV-photoemission investigation and DFT calculations on vinylferrocene (VFC), a redox molecule suitable for applications in molecular electronics. A detailed assignment is discussed of the valence photoelectron spectra (UPS), which provides new data on the electronic structure and offers a partial re-interpretation of previous assignments on VFC based on theoretical and experimental evidences. Furthermore, the present results can allow for a meaningful comparison of photoemission results from the corresponding hybrid obtained by covalently attaching VFC to Si oriented surfaces.

  14. Dynamical Coulomb blockade of the nonlocal conductance in normalmetal/superconductor hybrid structures

    Energy Technology Data Exchange (ETDEWEB)

    Kolenda, Stefan; Wolf, Michael J.; Beckmann, Detlef [Institut fuer Nanotechnologie, KIT, 76021 Karlsruhe (Germany)

    2013-07-01

    In normalmetal/superconductor hybrid structures nonlocal conductance is determined by crossed Andreev reflection (CAR) and elastic cotunneling (EC). This was investigated recently both experimentally and theoretically. Dynamical Coulomb blockade of EC and CAR was predicted theoretically. Here we report on experimental investigations of these effects. We found signatures of dynamical Coulomb blockade in local and nonlocal conductance in the normal state. In the superconducting state, we find s-shaped nonlocal differential conductance curves as a function of bias applied on both contacts. These curves were observed for bias voltages both below and above the gap. We compare our results to theory.

  15. Structure of hybrid protoneutron stars within the Nambu--Jona-Lasinio model

    CERN Document Server

    Burgio, G F

    2007-01-01

    We investigate the structure of protoneutron stars (PNS) formed by hadronic and quark matter in $\\beta$-equilibrium described by appropriate equations of state (EOS). For the hadronic matter, we use a finite temperature EOS based on the Brueckner-Bethe-Goldstone many-body theory, with realistic two- and three-body forces. For the quark sector, we employ the Nambu--Jona-Lasinio model. We find that the maximum allowed masses are comprised in a narrow range around 1.8 solar masses, with a slight dependence on the temperature. Metastable hybrid protoneutron stars are not found.

  16. Structure and properties of hybrid poly(2-hydroxyethyl methacrylate)/SiO2 monoliths

    DEFF Research Database (Denmark)

    Ji, Xiangling; Jiang, Shichun; Qiu, Xuepeng

    2003-01-01

    to HEMA, was varied between 100/0 and 0/100. Structural analysis was performed by IR and NMR. The NMR results indicated that the introduction of PHEMA in the silica networks gave rise to a lower degree of condensation of TEOS. The resulting monoliths showed more than 75% transmittance in the visible...... related to some degree of chemical crosslinking between the polymer and the silica moiety, which would greatly improve the thermal stability of such hybrid monoliths compared with a pure PHEMA....

  17. Resistive Switching Characteristics of Tantalum Oxide Thin Film and Titanium Oxide Nanoparticles Hybrid Structure.

    Science.gov (United States)

    Park, Mi Ra; Abbas, Yawar; Hu, Quanli; Yoon, Tae-Sik; Choi, Young Jin; Kang, Chi Jung

    2015-11-01

    The fabrication of hybrid structure with TiO2 nanoparticle assembly and Ta2O5 thin film layer was demonstrated. The close-packed nanoparticles could influence the resistive switching behaviors due to the huge numbers of interface states and vacancies in the nanoparticle assembly. The device with hybrid structure presented the typical bipolar resistive switching characteristics in the structure of Ti/TiO2/Ta2O5/Au on SiO2/Si substrate. The set voltage was observed at -0.7 V, and the reset voltage occurred at (-)-0.7 V, which was smaller than that of Ta2O5 layer only. The electrical conduction mechanisms were the ohmic conduction at low resistance state (LRS) and the space charge limited conduction at high resistance state (HRS), respectively. The devices showed stable current ratio of LRS to HRS. The temperature dependent properties of the devices were also investigated. The device with nanoparticle assembly showed better electrical characteristics with low HRS current level and stable LRS current level with respect to the temperature.

  18. Conceptual Design and Structural Optimization of NASA Environmentally Responsible Aviation (ERA) Hybrid Wing Body Aircraft

    Science.gov (United States)

    Quinlan, Jesse R.; Gern, Frank H.

    2016-01-01

    Simultaneously achieving the fuel consumption and noise reduction goals set forth by NASA's Environmentally Responsible Aviation (ERA) project requires innovative and unconventional aircraft concepts. In response, advanced hybrid wing body (HWB) aircraft concepts have been proposed and analyzed as a means of meeting these objectives. For the current study, several HWB concepts were analyzed using the Hybrid wing body Conceptual Design and structural optimization (HCDstruct) analysis code. HCDstruct is a medium-fidelity finite element based conceptual design and structural optimization tool developed to fill the critical analysis gap existing between lower order structural sizing approaches and detailed, often finite element based sizing methods for HWB aircraft concepts. Whereas prior versions of the tool used a half-model approach in building the representative finite element model, a full wing-tip-to-wing-tip modeling capability was recently added to HCDstruct, which alleviated the symmetry constraints at the model centerline in place of a free-flying model and allowed for more realistic center body, aft body, and wing loading and trim response. The latest version of HCDstruct was applied to two ERA reference cases, including the Boeing Open Rotor Engine Integration On an HWB (OREIO) concept and the Boeing ERA-0009H1 concept, and results agreed favorably with detailed Boeing design data and related Flight Optimization System (FLOPS) analyses. Following these benchmark cases, HCDstruct was used to size NASA's ERA HWB concepts and to perform a related scaling study.

  19. High regression rate hybrid rocket fuel grains with helical port structures

    Science.gov (United States)

    Walker, Sean D.

    Hybrid rockets are popular in the aerospace industry due to their storage safety, simplicity, and controllability during rocket motor burn. However, they produce fuel regression rates typically 25% lower than solid fuel motors of the same thrust level. These lowered regression rates produce unacceptably high oxidizer-to-fuel (O/F) ratios that produce a potential for motor instability, nozzle erosion, and reduced motor duty cycles. To achieve O/F ratios that produce acceptable combustion characteristics, traditional cylindrical fuel ports are fabricated with very long length-to-diameter ratios to increase the total burning area. These high aspect ratios produce further reduced fuel regression rate and thrust levels, poor volumetric efficiency, and a potential for lateral structural loading issues during high thrust burns. In place of traditional cylindrical fuel ports, it is proposed that by researching the effects of centrifugal flow patterns introduced by embedded helical fuel port structures, a significant increase in fuel regression rates can be observed. The benefits of increasing volumetric efficiencies by lengthening the internal flow path will also be observed. The mechanisms of this increased fuel regression rate are driven by enhancing surface skin friction and reducing the effect of boundary layer "blowing" to enhance convective heat transfer to the fuel surface. Preliminary results using additive manufacturing to fabricate hybrid rocket fuel grains from acrylonitrile-butadiene-styrene (ABS) with embedded helical fuel port structures have been obtained, with burn-rate amplifications up to 3.0x than that of cylindrical fuel ports.

  20. Detailed Post-Soft Impact Progressive Damage Assessment for Hybrid Structure Jet Engines

    Science.gov (United States)

    Siddens, Aaron; Bayandor, Javid; Celestina, Mark L.

    2014-01-01

    Currently, certification of engine designs for resistance to bird strike is reliant on physical tests. Predictive modeling of engine structural damage has mostly been limited to evaluation of individual forward section components, such as fan blades within a fixed frame of reference, to direct impact with a bird. Such models must be extended to include interactions among engine components under operating conditions to evaluate the full extent of engine damage. This paper presents the results of a study aim to develop a methodology for evaluating bird strike damage in advanced propulsion systems incorporating hybrid composite/metal structures. The initial degradation and failure of individual fan blades struck by a bird were investigated. Subsequent damage to other fan blades and engine components due to resultant violent fan assembly vibrations and fragmentation was further evaluated. Various modeling parameters for the bird and engine components were investigated to determine guidelines for accurately capturing initial damage and progressive failure of engine components. Then, a novel hybrid structure modeling approach was investigated and incorporated into the crashworthiness methodology. Such a tool is invaluable to the process of design, development, and certification of future advanced propulsion systems.

  1. Selective wrapping and supramolecular structures of polyfluorene-carbon nanotube hybrids.

    Science.gov (United States)

    Gao, Jia; Loi, Maria Antonietta; de Carvalho, Elton José Figueiredo; Dos Santos, Maria Cristina

    2011-05-24

    We report on the photophysical properties of single-walled carbon nanotube (SWNT) suspensions in toluene solutions of poly[9,9-dioctylfluorenyl-2,7-diyl](PFO). Steady-state and time-resolved photoluminescence spectroscopy in the near-infrared and visible spectral regions are used to study the interaction of the dispersed SWNTs with the wrapped polymer. Molecular dynamics simulations of the PFO-SWNT hybrids in toluene were carried out to evaluate the energetics of different wrapping geometries. The simulated fluorescence spectra in the visible region were obtained by the quantum chemical ZINDO-CI method, using a sampling of structures obtained from the dynamics trajectories. The tested schemes consider polymer chains aligned along the nanotube axis, where chirality has a minimal effect, or forming helical structures, where a preference for high chiral angles is evidenced. Moreover, toluene affects the polymer structure favoring the helical conformation. Simulations show that the most stable hybrid system is the PFO-wrapped (8,6) nanotube, in agreement with the experimentally observed selectivity.

  2. Enhanced photovoltaic performance of polymer-filled nanoporous Si hybrid structures.

    Science.gov (United States)

    Gang, Minjae; Lee, Joo-Hyoung

    2017-02-15

    We propose a novel hybrid structure for improving the efficiency of crystalline silicon solar cells. By employing first-principles calculations, we demonstrate that ordered, nanoporous silicon (np-Si), when filled with polythiophene (PT) inside the pores, exhibits a substantially enhanced absorption coefficient compared to both np-Si and the bulk, which makes the np-Si/PT heterojunction a superior light absorbing material. In addition, the PT-filled porous structure forms a staggered gap, or type II, heterojunction at the interfaces, where the valence band maximum and conduction band minimum of the composite reside on PT and np-Si, respectively. Moreover, the pore-filling polymer brings about a highly dispersive valence band, which provides a major pathway for hole transport. These results suggest that such a hybrid structure, which may be easier to scale up than nanowire-based approaches, will efficiently dissociate photo-induced electron-hole pairs and reduce the amount of material for light absorption, thus leading to a cost-effective and high-performance solar cell.

  3. Structural Variations in Hybrid All-Nanoparticle Gibbsite Nanoplatelet/Cellulose Nanocrystal Multilayered Films.

    Science.gov (United States)

    Martin, Clélia; Barker, Robert; Watkins, Erik B; Dubreuil, Frédéric; Cranston, Emily D; Heux, Laurent; Jean, Bruno

    2017-08-15

    Cellulose nanocrystals (CNCs) are promising biosourced building blocks for the production of high performance materials. In the last ten years, CNCs have been used in conjunction with polymers for the design of multilayered thin films via the layer-by-layer assembly technique. Herein, polymer chains have been replaced with positively charged inorganic gibbsite nanoplatelets (GN) to form hybrid "nanoparticle-only" composite films. A combination of atomic force microscopy and neutron reflectivity experiments was exploited to investigate the growth and structure of the films. Data show that the growth and density of GN/CNC films can be tuned over a wide range during preparation by varying the ionic strength in the CNC suspension and the film drying protocol. Specifically, thin and dense multilayered films or very thick, more porous mixed slabs, as well as intermediate internal structures, could be obtained in a predictable manner. The influence of key physicochemical parameters on the multilayer film buildup was elucidated and the film architecture was linked to the dominating interaction forces between the components. The degree of structural control over these hybrid nanoparticle-only films is much higher than that reported for CNC/polymer films, which offers new properties and potential applications as separation membranes or flame retardant coatings.

  4. Effect of graphene on photoluminescence properties of graphene/GeSi quantum dot hybrid structures

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y. L.; Ma, Y. J.; Wang, W. Q.; Ding, K.; Wu, Q.; Fan, Y. L.; Yang, X. J.; Zhong, Z. Y.; Jiang, Z. M., E-mail: zmjiang@fudan.edu.cn [State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education) and Department of Physics, Fudan University, Shanghai 200433 (China); Chen, D. D.; Xu, F. [SHU-SolarE R and D Lab, Department of Physics, College of Science, Shanghai University, Shanghai 200444 (China)

    2014-07-14

    Graphene has been discovered to have two effects on the photoluminescence (PL) properties of graphene/GeSi quantum dot (QD) hybrid structures, which were formed by covering monolayer graphene sheet on the multilayer ordered GeSi QDs sample surfaces. At the excitation of 488 nm laser line, the hybrid structure had a reduced PL intensity, while at the excitation of 325 nm, it had an enhanced PL intensity. The attenuation in PL intensity can be attributed to the transferring of electrons from the conducting band of GeSi QDs to the graphene sheet. The electron transfer mechanism was confirmed by the time resolved PL measurements. For the PL enhancement, a mechanism called surface-plasmon-polariton (SPP) enhanced absorption mechanism is proposed, in which the excitation of SPP in the graphene is suggested. Due to the resonant excitation of SPP by incident light, the absorption of incident light is much enhanced at the surface region, thus leading to more exciton generation and a PL enhancement in the region. The results may be helpful to provide us a way to improve optical properties of low dimensional surface structures.

  5. 3D Digital Design of Cranes' Structures Based on Hybrid Software Architecture

    Institute of Scientific and Technical Information of China (English)

    WANG Chonghua; LI Hua

    2006-01-01

    3D digital design for cranes' structures based on hybrid software architecture of Client/Server and Browser/Server is introduced in this paper. Based on Pro/ENGINEER platform, 3D parametric model family is built to allow generation of feasible configurations of cranes' structures in Client/Server framework. Taking use of Visual C++, the second exploiting software kit provided by Pro/ENGINEER and ANSYS GUI/APDL modeling patterns, an integration method of 3D CAD and CAE is achieved, which includes regeneration of 3D parametric model, synchronous updating and analysis of FEA model. As in Browser/Server framework, the 3D CAD models of parts, components and the whole structure could also be displayed in the customer's browser in VRML format.

  6. Tuning the band gap in hybrid tin iodide perovskite semiconductors using structural templating.

    Science.gov (United States)

    Knutson, Jeremy L; Martin, James D; Mitzi, David B

    2005-06-27

    Structural distortions within the extensive family of organic/inorganic hybrid tin iodide perovskite semiconductors are correlated with their experimental exciton energies and calculated band gaps. The extent of the in- and out-of-plane angular distortion of the SnI4(2-) perovskite sheets is largely determined by the relative charge density and steric requirements of the organic cations. Variation of the in-plane Sn-I-Sn bond angle was demonstrated to have the greatest impact on the tuning of the band gap, and the equatorial Sn-I bond distances have a significant secondary influence. Extended Hückel tight-binding band calculations are employed to decipher the crystal orbital origins of the structural effects that fine-tune the band structure. The calculations suggest that it may be possible to tune the band gap by as much as 1 eV using the templating influence of the organic cation.

  7. A Novel Hybrid Semi-Active Mass Damper Configuration for Structural Applications

    Directory of Open Access Journals (Sweden)

    Demetris Demetriou

    2016-11-01

    Full Text Available In this paper, a novel energy- and cost-efficient hybrid semi-active mass damper configuration for use in structural applications has been developed. For this task, an arrangement of both active and semi-active control components coupled with appropriate control algorithms are constructed and their performance is evaluated on both single and multi-degree of freedom structures for which practical constraints such as stroke and force saturation limits are taken into account. It is shown that under both free and forced vibrations, the novel device configuration outperforms its more conventional passive and semi-active counterparts, while at the same time achieving performance gains similar to the active configuration at considerably less energy and actuation demands, satisfying both strict serviceability and sustainability requirements often found to govern most modern structural applications.

  8. Hybrid yttrium iron garnet-ferromagnet structures for spin-wave devices

    Energy Technology Data Exchange (ETDEWEB)

    Papp, A., E-mail: apapp@nd.edu [Center for Nano Science and Technology and Department of Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Pázmány Péter Catholic University, Faculty of Information Technology, Budapest 1088 (Hungary); Porod, W., E-mail: porod@nd.edu; Csaba, G., E-mail: gcsaba@nd.edu [Center for Nano Science and Technology and Department of Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States)

    2015-05-07

    We study coupled ferromagnetic layers, which could facilitate low loss, sub 100 nm wavelength spin-wave propagation and manipulation. One of the layers is a low-loss garnet film (such as yttrium iron garnet (YIG)) that enables long-distance, coherent spin-wave propagation. The other layer is made of metal-based (Permalloy, Co, and CoFe) magnetoelectronic structures that can be used to generate, manipulate, and detect the spin waves. Using micromagnetic simulations, we analyze the interactions between the spin waves in the YIG and the metallic nanomagnet structures and demonstrate the components of a scalable spin-wave based signal processing device. We argue that such hybrid-metallic ferromagnet structures can be the basis of potentially high-performance, ultra low-power computing devices.

  9. Structures of the Bacterial Ribosome in Classical and Hybrid States of tRNA Binding

    Energy Technology Data Exchange (ETDEWEB)

    Dunkle, Jack A.; Wang, Leyi; Feldman, Michael B.; Pulk, Arto; Chen, Vincent B.; Kapral, Gary J.; Noeske, Jonas; Richardson, Jane S.; Blanchard, Scott C.; Cate, Jamie H. Doudna (Cornell); (UCB); (Duke)

    2011-09-06

    During protein synthesis, the ribosome controls the movement of tRNA and mRNA by means of large-scale structural rearrangements. We describe structures of the intact bacterial ribosome from Escherichia coli that reveal how the ribosome binds tRNA in two functionally distinct states, determined to a resolution of {approx}3.2 angstroms by means of x-ray crystallography. One state positions tRNA in the peptidyl-tRNA binding site. The second, a fully rotated state, is stabilized by ribosome recycling factor and binds tRNA in a highly bent conformation in a hybrid peptidyl/exit site. The structures help to explain how the ratchet-like motion of the two ribosomal subunits contributes to the mechanisms of translocation, termination, and ribosome recycling.

  10. Numerical Simulation of Solitary Wave Induced Flow Motion around a Permeable Submerged Breakwater

    Directory of Open Access Journals (Sweden)

    Jisheng Zhang

    2012-01-01

    Full Text Available This paper presents a numerical model for the simulation of solitary wave transformation around a permeable submerged breakwater. The wave-structure interaction is obtained by solving the Volume-Averaged Reynolds-Averaged Navier-Stokes governing equations (VARANS and volume of fluid (VOF theory. This model is applied to understand the effects of porosity, equivalent mean diameter of porous media, structure height, and structure width on the propagation of a solitary wave in the vicinity of a permeable submerged structure. The results show that solitary wave propagation around a permeable breakwater is essentially different from that around impermeable one. It is also found that the structure porosity has more impact than equivalent mean diameter on the wave transformation and flow structure. After interacting with the higher structure, the wave has smaller wave height behind the structure with a lower travelling speed. When the wave propagates over the breakwater with longer width, the wave travelling speed is obviously reduced with more wave energy dissipated inside porous structure.

  11. Structure and weights optimisation of a modified Elman network emotion classifier using hybrid computational intelligence algorithms: a comparative study

    Science.gov (United States)

    Sheikhan, Mansour; Abbasnezhad Arabi, Mahdi; Gharavian, Davood

    2015-10-01

    Artificial neural networks are efficient models in pattern recognition applications, but their performance is dependent on employing suitable structure and connection weights. This study used a hybrid method for obtaining the optimal weight set and architecture of a recurrent neural emotion classifier based on gravitational search algorithm (GSA) and its binary version (BGSA), respectively. By considering the features of speech signal that were related to prosody, voice quality, and spectrum, a rich feature set was constructed. To select more efficient features, a fast feature selection method was employed. The performance of the proposed hybrid GSA-BGSA method was compared with similar hybrid methods based on particle swarm optimisation (PSO) algorithm and its binary version, PSO and discrete firefly algorithm, and hybrid of error back-propagation and genetic algorithm that were used for optimisation. Experimental tests on Berlin emotional database demonstrated the superior performance of the proposed method using a lighter network structure.

  12. A model for ion-acoustic solitary waves with streaming non-Maxwellian electrons in space plasmas

    Science.gov (United States)

    Khalid Hussain, Shah; Nouman Sarwar, Qureshi Muhammad

    2016-04-01

    Solitons are nonlinear solitary structures and are integral part of space plasmas. Such nonlinear structures, accompanied by streaming electrons are frequently observed by various satellites in different regions of near Earth plasmas such as Earth's bow shock, magnetopause, auroral zone, etc. In this paper, we present a fluid model consisting streaming non-Maxwellian electrons along the magnetic field and derived the Sagdeev potential for fully nonlinear fluid equations. We found that compressive solitons can be developed in such a plasma. The results from our model can be used to interpret solitary structures in space plasmas when there is streaming electron obeying the non-Maxwellian distributions

  13. Stable complex solitary waves of Sasa Satsuma equation

    Indian Academy of Sciences (India)

    Sasanka Ghosh

    2001-11-01

    Existence of a new class of complex solitary waves is shown for Sasa Satsuma equation. These solitary waves are found to be stable in a certain domain of the parameter and become chaotic if the parameter exceeds the value 2.4. Significantly, the complex solitary waves propagate at higher bit rate over the most stable solitons under the same conditions of the input parameters.

  14. Numerical Study on Breaking Criteria for Solitary Waves

    Institute of Scientific and Technical Information of China (English)

    Chung-ren CHOU; Ruey-syan SHIH; John Z. YIM

    2003-01-01

    Studies of the breaking criteria for solitary waves on a slope are presented in this paper. The boundary element method is used to model the processes of shoaling and breaking of solitary waves on various slopes. Empirical formulae that can be used to characterize the breaking of solitary waves are presented. These include the breaking index, the wave height, the water depth, and the maximum particle velocity at the point of breaking. Comparisons with the results of other researches are given.

  15. Structure-Property-Processing Correlations in Freeze-Cast Hybrid Scaffolds

    Science.gov (United States)

    Hunger, Philipp Malte

    Porous materials are highly sought after for applications ranging from catalyst carriers to tissue scaffolds. Most applications require clearly defined structural features and a specific mechanical performance. Therefore, it is essential to establish systematic structure-property-processing correlations to be able to tailor both structure and mechanical properties for a particular application. Because the introduction of porosity is detrimental to the mechanical performance of highly porous structures, it is necessary to generate a structure that allows for the mechanical properties to be maximized. One example for such a structure are honeycombs. In addition to the porosity and pore morphology, the scaffold's performance depends on the properties inherent to the material from which it is made. Polymeric foams possess high toughness but low stiffness, whereas ceramic foams possess high stiffness but low toughness. Natural composites like bone, antler and nacre have both high stiffness and high toughness. This unusual set of mechanical properties is thought to be intricately linked to the multi-level hierarchical composite structure present in these materials. Great potential for the fabrication of stiff, strong and tough porous scaffolds is thus seen in nacre-like composite materials with a hierarchical, honeycomb-like structure. Freeze casting is a method with which such hybrid materials can be made, adding the third dimension to nacre by forming a highly porous, hierarchical bulk material, with dense, nacre-like cell walls. The nacre-like cell walls self-assemble during the directional freezing of a water-based ceramic-polymer slurry. Reported here are structure-property-processing correlations observed in these materials. They are unusual, because they are, like nacre, solely glued by a polymeric phase and not processed further by sintering. The results illustrate several pathways to control both structure and mechanical properties in freeze-cast composites and

  16. Dependence of SERS enhancement on the chemical composition and structure of Ag/Au hybrid nanoparticles.

    Science.gov (United States)

    Chaffin, Elise; O'Connor, Ryan T; Barr, James; Huang, Xiaohua; Wang, Yongmei

    2016-08-01

    Noble metal nanoparticles (NPs) such as silver (Ag) and gold (Au) have unique plasmonic properties that give rise to surface enhanced Raman scattering (SERS). Generally, Ag NPs have much stronger plasmonic properties and, hence, provide stronger SERS signals than Au NPs. However, Ag NPs lack the chemical stability and biocompatibility of comparable Au NPs and typically exhibit the most intense plasmonic resonance at wavelengths much shorter than the optimal spectral region for many biomedical applications. To overcome these issues, various experimental efforts have been devoted to the synthesis of Ag/Au hybrid NPs for the purpose of SERS detections. However, a complete understanding on how the SERS enhancement depends on the chemical composition and structure of these nanoparticles has not been achieved. In this study, Mie theory and the discrete dipole approximation have been used to calculate the plasmonic spectra and near-field electromagnetic enhancements of Ag/Au hybrid NPs. In particular, we discuss how the electromagnetic enhancement depends on the mole fraction of Au in Ag/Au alloy NPs and how one may use extinction spectra to distinguish between Ag/Au alloyed NPs and Ag-Au core-shell NPs. We also show that for incident laser wavelengths between ∼410 nm and 520 nm, Ag/Au alloyed NPs provide better electromagnetic enhancement than pure Ag, pure Au, or Ag-Au core-shell structured NPs. Finally, we show that silica-core Ag/Au alloy shelled NPs provide even better performance than pure Ag/Au alloy or pure solid Ag and pure solid Au NPs. The theoretical results presented will be beneficial to the experimental efforts in optimizing the design of Ag/Au hybrid NPs for SERS-based detection methods.

  17. Research of hail impact on aircraft wheel door with lattice hybrid structure

    Science.gov (United States)

    Li, Shengze; Jin, Feng; Zhang, Weihua; Meng, Xuanzhu

    2016-09-01

    Aimed at a long lasting issue of hail impact on aircraft structures and aviation safety due to its high speed, the resistance performance of hail impact on the wheel door of aircraft with lattice hybrid structure is investigated. The proper anti-hail structure can be designed both efficiency and precision based on this work. The dynamic responses of 8 different sandwich plates in diverse impact speed are measured. Smoothed Particle Hydrodynamic (SPH) method is introduced to mimic the speciality of solid-liquid mixture trait of hailstone during the impact process. The deformation and damage degree of upper and lower panel of sandwich plate are analysed. The application range and failure mode for the relevant structure, as well as the energy absorbing ratio between lattice structure and aluminium foam are summarized. Results show that the tetrahedral sandwich plate with aluminium foam core is confirmed the best for absorbing energy. Furthermore, the high absorption characteristics of foam material enhance the capability of the impact resistance for the composition with lattice structure without increasing the structure surface density. The results of study are of worth to provide a reliable basis for reduced weight aircraft wheel door.

  18. A hybrid system identification methodology for wireless structural health monitoring systems based on dynamic substructuring

    Science.gov (United States)

    Dragos, Kosmas; Smarsly, Kay

    2016-04-01

    System identification has been employed in numerous structural health monitoring (SHM) applications. Traditional system identification methods usually rely on centralized processing of structural response data to extract information on structural parameters. However, in wireless SHM systems the centralized processing of structural response data introduces a significant communication bottleneck. Exploiting the merits of decentralization and on-board processing power of wireless SHM systems, many system identification methods have been successfully implemented in wireless sensor networks. While several system identification approaches for wireless SHM systems have been proposed, little attention has been paid to obtaining information on the physical parameters (e.g. stiffness, damping) of the monitored structure. This paper presents a hybrid system identification methodology suitable for wireless sensor networks based on the principles of component mode synthesis (dynamic substructuring). A numerical model of the monitored structure is embedded into the wireless sensor nodes in a distributed manner, i.e. the entire model is segmented into sub-models, each embedded into one sensor node corresponding to the substructure the sensor node is assigned to. The parameters of each sub-model are estimated by extracting local mode shapes and by applying the equations of the Craig-Bampton method on dynamic substructuring. The proposed methodology is validated in a laboratory test conducted on a four-story frame structure to demonstrate the ability of the methodology to yield accurate estimates of stiffness parameters. Finally, the test results are discussed and an outlook on future research directions is provided.

  19. The cruel and unusual phenomenology of solitary confinement

    Directory of Open Access Journals (Sweden)

    Shaun eGallagher

    2014-06-01

    Full Text Available What happens when subjects are deprived of intersubjective contact? This paper looks closely at the phenomenology and psychology of one example of that deprivation: solitary confinement. It also puts the phenomenology and psychology of solitary confinement to use in the legal context. Not only is there no consensus on whether solitary confinement is a cruel and unusual punishment, there is no consensus on the definition of the term ‘cruel’ in the use of that legal phrase. I argue that we can find a moral consensus on the meaning of ‘cruelty’ by looking specifically at the phenomenology and psychology of solitary confinement.

  20. The cruel and unusual phenomenology of solitary confinement.

    Science.gov (United States)

    Gallagher, Shaun

    2014-01-01

    What happens when subjects are deprived of intersubjective contact? This paper looks closely at the phenomenology and psychology of one example of that deprivation: solitary confinement. It also puts the phenomenology and psychology of solitary confinement to use in the legal context. Not only is there no consensus on whether solitary confinement is a "cruel and unusual punishment," there is no consensus on the definition of the term "cruel" in the use of that legal phrase. I argue that we can find a moral consensus on the meaning of "cruelty" by looking specifically at the phenomenology and psychology of solitary confinement.

  1. MALIGNANT CHANGE IN A SOLITARY CYLINDROMA: A RARE CASE REPORT

    Directory of Open Access Journals (Sweden)

    Shivaji D

    2014-06-01

    Full Text Available Cylindroma is a rare tumour which originates from skin appendages. Cylindromas are of two types namely solitary and multiple. Malignant transformation of cylindroma is unusual and is extremely rare in solitary type. They show strong predilection for middle aged and elderly females. We report a case of a 70 year old male patient presented with nodular swelling along with surface ulceration in the right axillary region since six months, which on histopathological examination revealed a case of malignant transformation of benign solitary cylindroma. We report a rare case of malignant cylindroma arising in a patient with solitary cylindroma at an unusual site

  2. Synthesis and Crystal Structure of the First Hybrid Manganese Phosphate with 1-D Framework of Dinuclear Structure

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A novel hybrid manganese phosphate, [(bipy)Mn(H2PO4)2] (bipy = 2,2'-bipyridine) 1, was synthesized, and its structure is characteristic of 1-D framework involving a dinuclear structure made up of edge-sharing Mn(II) octahedra. 1 crystallizes in the monoclinic system, space group C2/c with a = 12.230(2), b = 17.800(4), c = 13.530(3)(A), β = 105.00(3)o, V = 2845.0(10)(A)3, Z = 8. Dc = 1.892 g/cm3, F(000) = 1640, Mr = 405.10, μ(MoKα) = 1.198 mm-1, R = 0.0306 and wR = 0.0657 for 2093 observed reflections (I > 2σ(I)).

  3. Structured oligonucleotides for target indexing to allow single-vessel PCR amplification and solid support microarray hybridization.

    Science.gov (United States)

    Girard, Laurie D; Boissinot, Karel; Peytavi, Régis; Boissinot, Maurice; Bergeron, Michel G

    2015-02-07

    The combination of molecular diagnostic technologies is increasingly used to overcome limitations on sensitivity, specificity or multiplexing capabilities, and provide efficient lab-on-chip devices. Two such techniques, PCR amplification and microarray hybridization are used serially to take advantage of the high sensitivity and specificity of the former combined with high multiplexing capacities of the latter. These methods are usually performed in different buffers and reaction chambers. However, these elaborate methods have high complexity and cost related to reagent requirements, liquid storage and the number of reaction chambers to integrate into automated devices. Furthermore, microarray hybridizations have a sequence dependent efficiency not always predictable. In this work, we have developed the concept of a structured oligonucleotide probe which is activated by cleavage from polymerase exonuclease activity. This technology is called SCISSOHR for Structured Cleavage Induced Single-Stranded Oligonucleotide Hybridization Reaction. The SCISSOHR probes enable indexing the target sequence to a tag sequence. The SCISSOHR technology also allows the combination of nucleic acid amplification and microarray hybridization in a single vessel in presence of the PCR buffer only. The SCISSOHR technology uses an amplification probe that is irreversibly modified in presence of the target, releasing a single-stranded DNA tag for microarray hybridization. Each tag is composed of a 3-nucleotide sequence-dependent segment and a unique "target sequence-independent" 14-nucleotide segment allowing for optimal hybridization with minimal cross-hybridization. We evaluated the performance of five (5) PCR buffers to support microarray hybridization, compared to a conventional hybridization buffer. Finally, as a proof of concept, we developed a multiplexed assay for the amplification, detection, and identification of three (3) DNA targets. This new technology will facilitate the design

  4. Fluorescence in situ hybridization applications for super-resolution 3D structured illumination microscopy.

    Science.gov (United States)

    Markaki, Yolanda; Smeets, Daniel; Cremer, Marion; Schermelleh, Lothar

    2013-01-01

    Fluorescence in situ hybridization on three-dimensionally preserved cells (3D-FISH) is an efficient tool to analyze the subcellular localization and spatial arrangement of targeted DNA sequences and RNA transcripts at the single cell level. 3D reconstructions from serial optical sections obtained by confocal laser scanning microscopy (CLSM) have long been considered the gold standard for 3D-FISH analyses. Recent super-resolution techniques circumvent the diffraction-limit of optical resolution and have defined a new state-of-the-art in bioimaging. Three-dimensional structured illumination microscopy (3D-SIM) represents one of these technologies. Notably, 3D-SIM renders an eightfold improved volumetric resolution over conventional imaging, and allows the simultaneous visualization of differently labeled target structures. These features make this approach highly attractive for the analysis of spatial relations and substructures of nuclear targets that escape detection by conventional light microscopy. Here, we focus on the application of 3D-SIM for the visualization of subnuclear 3D-FISH preparations. In comparison with conventional fluorescence microscopy, the quality of 3D-SIM data is dependent to a much greater extent on the optimal sample preparation, labeling and acquisition conditions. We describe typical problems encountered with super-resolution imaging of in situ hybridizations in mammalian tissue culture cells and provide optimized DNA-/(RNA)-FISH protocols including combinations with immunofluorescence staining (Immuno-FISH) and DNA replication labeling using click chemistry.

  5. AC loss measurements in HTS coil assemblies with hybrid coil structures

    Science.gov (United States)

    Jiang, Zhenan; Long, Nicholas J.; Staines, Mike; Badcock, Rodney A.; Bumby, Chris W.; Buckley, Robert G.; Amemiya, Naoyuki

    2016-09-01

    Both AC loss and wire cost in coil windings are critical factors for high temperature superconductor (HTS) AC machinery applications. We present AC loss measurement results in three HTS coil assemblies at 77 K and 65 K which have a hybrid coil structure comprising one central winding (CW) and two end windings (EWs) wound with ReBCO and BSCCO wires with different self-field I c values at 77 K. All AC loss results in the coil assemblies are hysteretic and the normalized AC losses in the coil assemblies at different temperatures can be scaled with the I c value of the coil assemblies. The normalised results show that AC loss in a coil assembly with BSCCO CW can be reduced by using EWs wound with high I c ReBCO wires, whilst further AC loss reduction can be achieved by replacing the BSCCO CW with ReBCO CW. The results imply that a flexible hybrid coil structure is possible which considers both AC loss and wire cost in coil assemblies.

  6. Unexpected structural complexity of supernumerary marker chromosomes characterized by microarray comparative genomic hybridization

    Directory of Open Access Journals (Sweden)

    Hing Anne V

    2008-04-01

    Full Text Available Abstract Background Supernumerary marker chromosomes (SMCs are structurally abnormal extra chromosomes that cannot be unambiguously identified by conventional banding techniques. In the past, SMCs have been characterized using a variety of different molecular cytogenetic techniques. Although these techniques can sometimes identify the chromosome of origin of SMCs, they are cumbersome to perform and are not available in many clinical cytogenetic laboratories. Furthermore, they cannot precisely determine the region or breakpoints of the chromosome(s involved. In this study, we describe four patients who possess one or more SMCs (a total of eight SMCs in all four patients that were characterized by microarray comparative genomic hybridization (array CGH. Results In at least one SMC from all four patients, array CGH uncovered unexpected complexity, in the form of complex rearrangements, that could have gone undetected using other molecular cytogenetic techniques. Although array CGH accurately defined the chromosome content of all but two minute SMCs, fluorescence in situ hybridization was necessary to determine the structure of the markers. Conclusion The increasing use of array CGH in clinical cytogenetic laboratories will provide an efficient method for more comprehensive characterization of SMCs. Improved SMC characterization, facilitated by array CGH, will allow for more accurate SMC/phenotype correlation.

  7. Hybrid micro-/nano-structures derived from metal-organic frameworks: preparation and applications in energy storage and conversion.

    Science.gov (United States)

    Cao, Xiehong; Tan, Chaoliang; Sindoro, Melinda; Zhang, Hua

    2017-05-22

    Metal-organic frameworks (MOFs), an important class of inorganic-organic hybrid crystals with intrinsic porous structures, can be used as versatile precursors or sacrificial templates for preparation of numerous functional nanomaterials for various applications. Recent developments of MOF-derived hybrid micro-/nano-structures, constructed by more than two components with varied functionalities, have revealed their extensive capabilities to overcome the weaknesses of the individual counterparts and thus give enhanced performance for energy storage and conversion. In this tutorial review, we summarize the recent advances in MOF-derived hybrid micro-/nano-structures. The synthetic strategies for preparing MOF-derived hybrid micro-/nano-structures are first introduced. Focusing on energy storage and conversion, we then discuss their potential applications in lithium-ion batteries, lithium-sulfur batteries, supercapacitors, lithium-oxygen batteries and fuel cells. Finally, we give our personal insights into the challenges and opportunities for the future research of MOF-derived hybrid micro-/nano-structures.

  8. Oblique propagation of ion-acoustic solitary waves in a magnetized electron-positron-ion plasma

    Energy Technology Data Exchange (ETDEWEB)

    Ferdousi, M.; Sultana, S.; Mamun, A. A. [Department of Physics, Jahangirnagar University, Savar, Dhaka-1342 (Bangladesh)

    2015-03-15

    The properties of obliquely propagating ion-acoustic solitary waves in the presence of ambient magnetic field have been investigated theoretically in an electron-positron-ion nonthermal plasma. The plasma nonthermality is introduced via the q-nonextensive distribution of electrons and positrons. The Korteweg-de Vries (K-dV) and modified K-dV (mK-dV) equations are derived by adopting reductive perturbation method. The solution of K-dV and modified K-dV equation, which describes the solitary wave characteristics in the long wavelength limit, is obtained by steady state approach. It is seen that the electron and positron nonextensivity and external magnetic field (obliqueness) have significant effects on the characteristics of solitary waves. A critical value of nonextensivity is found for which solitary structures transit from positive to negative potential. The findings of this investigation may be used in understanding the wave propagation in laboratory and space plasmas where static external magnetic field is present.

  9. Small amplitude electron acoustic solitary waves in a magnetized superthermal plasma

    Science.gov (United States)

    Devanandhan, S.; Singh, S. V.; Lakhina, G. S.; Bharuthram, R.

    2015-05-01

    The propagation of electron acoustic solitary waves in a magnetized plasma consisting of fluid cold electrons, electron beam and superthermal hot electrons (obeying kappa velocity distribution function) and ion is investigated in a small amplitude limit using reductive perturbation theory. The Korteweg-de-Vries-Zakharov-Kuznetsov (KdV-ZK) equation governing the dynamics of electron acoustic solitary waves is derived. The solution of the KdV-ZK equation predicts the existence of negative potential solitary structures. The new results are: (1) increase of either the beam speed or temperature of beam electrons tends to reduce both the amplitude and width of the electron acoustic solitons, (2) the inclusion of beam speed and temperature pushes the allowed Mach number regime upwards and (3) the soliton width maximizes at certain angle of propagation (αm) and then decreases for α >αm . In addition, increasing the superthermality of the hot electrons also results in reduction of soliton amplitude and width. For auroral plasma parameters observed by Viking, the obliquely propagating electron-acoustic solitary waves have electric field amplitudes in the range (7.8-45) mV/m and pulse widths (0.29-0.44) ms. The Fourier transform of these electron acoustic solitons would result in a broadband frequency spectra with peaks near 2.3-3.5 kHz, thus providing a possible explanation of the broadband electrostatic noise observed during the Burst a.

  10. A hybrid-stress solid-shell element for non-linear analysis of piezoelectric structures

    Institute of Scientific and Technical Information of China (English)

    SZE; K; Y

    2009-01-01

    This paper presents eight-node solid-shell elements for geometric non-linear analyze of piezoelectric structures. To subdue shear, trapezoidal and thickness locking, the assumed natural strain method and an ad hoc modified generalized laminate stiffness matrix are employed. With the generalized stresses arising from the modified generalized laminate stiffness matrix assumed to be independent from the ones obtained from the displacement, an extended Hellinger-Reissner functional can be derived. By choosing the assumed generalized stresses similar to the assumed stresses of a previous solid ele- ment, a hybrid-stress solid-shell element is formulated. The presented finite shell element is able to model arbitrary curved shell structures. Non-linear numerical examples demonstrate the ability of the proposed model to analyze nonlinear piezoelectric devices.

  11. Hybrid Visual Servoing Control for Robotic Arc Welding Based on Structured Light Vision

    Institute of Scientific and Technical Information of China (English)

    XUDe; WANGLin-Kun; TUZhi-Guo; TANMin

    2005-01-01

    A novel hybrid visual servoing control method based on structured light vision is proposed for robotic arc welding with a general six degrees of freedom robot. It consists of a position control inner-loop in Cartesian space and two outer-loops. One is position-based visual control inCartesian space for moving in the direction of weld seam, i.e., weld seam tracking, another is imagebased visual control in image space for adjustment to eliminate the errors in the process of tracking.A new Jacobian matrix from image space of the feature point on structured light stripe to Cartesian space is provided for differential movement of the end-effector. The control system model is simplified and its stability is discussed. An experiment of arc welding protected by gas CO2 for verifying is well conducted.

  12. Combined Laser Beam Welding and Brazing Process for Aluminium Titanium Hybrid Structures

    Science.gov (United States)

    Möller, F.; Grden, M.; Thomy, C.; Vollertsen, F.

    The current state of the art in light-weight construction is - for the case of aircraft structures - the use of either aluminium or titanium. Whereas aluminium is light-weight and less expensive, titanium offers superior corrosion properties at higher cost. In order to combine the advantages of both materials, a hybrid Ti-Al structure is proposed for e.g. seat-track application. In this paper, an overview of the results from this research work and the accompanying thermo-mechanical simulations will be reported and discussed. On the basis of the development of an appropriate system technology, the process development will be described, focusing on the main influencing parameters of the process on joint properties.

  13. Numerical estimation of structure composition in laser-arc hybrid welded joints

    Directory of Open Access Journals (Sweden)

    W. Piekarska

    2010-10-01

    Full Text Available This work presents results of numerical estimation of the structure composition in laser-arc hybrid welded joints. Temperature field wasobtained by the solution of the heat transfer equation with activity of inner heat sources. Convective motion of liquid metal in the welding pool, latent heat of fusion and latent heat of phase transformation were taken into account in the algorithms for numerical analysis of the temperature field. The volumetric fractions of arising phases were determined on the basis of Johnson - Mehl - Avrami (JMA model for diffusive transformations and Koistinen - Marburger (KM model for martensitic transformation. On the basis of calculated temperature distribution the structure composition in welded joint was numerically estimated, taking into account CHT and CCT diagrams for S355 steel.

  14. Structural Acoustic Response of a Shape Memory Alloy Hybrid Composite Panel (Lessons Learned)

    Science.gov (United States)

    Turner, Travis L.

    2002-01-01

    This study presents results from an effort to fabricate a shape memory alloy hybrid composite (SMAHC) panel specimen and test the structure for dynamic response and noise transmission characteristics under the action of thermal and random acoustic loads. A method for fabricating a SMAHC laminate with bi-directional SMA reinforcement is described. Glass-epoxy unidirectional prepreg tape and Nitinol ribbon comprise the material system. Thermal activation of the Nitinol actuators was achieved through resistive heating. The experimental hardware required for mechanical support of the panel/actuators and for establishing convenient electrical connectivity to the actuators is presented. Other experimental apparatus necessary for controlling the panel temperature and acquiring structural acoustic data are also described. Deficiency in the thermal control system was discovered in the process of performing the elevated temperature tests. Discussion of the experimental results focuses on determining the causes for the deficiency and establishing means for rectifying the problem.

  15. Hybrid graphene/geopolymeric cement as a superionic conductor for structural health monitoring applications

    Science.gov (United States)

    Saafi, M.; Piukovics, G.; Ye, J.

    2016-10-01

    In this paper, we demonstrate for the first time a novel hybrid superionic long gauge sensor for structural health monitoring applications. The sensor consists of two graphene electrodes and a superionic conductor film made entirely of fly ash geopolymeric material. The sensor employs ion hopping as a conduction mechanism for high precision temperature and tensile strain sensing in structures. The design, fabrication and characterization of the sensor are presented. The temperature and strain sensing mechanisms of the sensor are also discussed. The experimental results revealed that the crystal structure of the superionic film is a 3D sodium-poly(sialate-siloxo) framework, with a room temperature ionic conductivity between 1.54 × 10-2 and 1.72 × 10-2 S m-1 and, activation energy of 0.156 eV, which supports the notion that ion hopping is the main conduction mechanism for the sensor. The sensor showed high sensitivity to both temperature and tensile strain. The sensor exhibited temperature sensitivity as high as 21.5 kΩ °C-1 and tensile strain sensitivity (i.e., gauge factor) as high as 358. The proposed sensor is relatively inexpensive and can easily be manufactured with long gauges to measure temperature and bulk strains in structures. With further development and characterization, the sensor can be retrofitted onto existing structures such as bridges, buildings, pipelines and wind turbines to monitor their structural integrity.

  16. Spatial genetic and morphologic structure of wolves and coyotes in relation to environmental heterogeneity in a Canis hybrid zone.

    Science.gov (United States)

    Benson, John F; Patterson, Brent R; Wheeldon, Tyler J

    2012-12-01

    Eastern wolves have hybridized extensively with coyotes and gray wolves and are listed as a 'species of special concern' in Canada. However, a distinct population of eastern wolves has been identified in Algonquin Provincial Park (APP) in Ontario. Previous studies of the diverse Canis hybrid zone adjacent to APP have not linked genetic analysis with field data to investigate genotype-specific morphology or determine how resident animals of different ancestry are distributed across the landscape in relation to heterogeneous environmental conditions. Accordingly, we studied resident wolves and coyotes in and adjacent to APP to identify distinct Canis types, clarify the extent of the APP eastern wolf population beyond the park boundaries and investigate fine-scale spatial genetic structure and landscape-genotype associations in the hybrid zone. We documented three genetically distinct Canis types within the APP region that also differed morphologically, corresponding to putative gray wolves, eastern wolves and coyotes. We also documented a substantial number of hybrid individuals (36%) that were admixed between 2 or 3 of the Canis types. Breeding eastern wolves were less common outside of APP, but occurred in some unprotected areas where they were sympatric with a diverse combination of coyotes, gray wolves and hybrids. We found significant spatial genetic structure and identified a steep cline extending west from APP where the dominant genotype shifted abruptly from eastern wolves to coyotes and hybrids. The genotypic pattern to the south and northwest was a more complex mosaic of alternating genotypes. We modelled genetic ancestry in response to prey availability and human disturbance and found that individuals with greater wolf ancestry occupied areas of higher moose density and fewer roads. Our results clarify the structure of the Canis hybrid zone adjacent to APP and provide unique insight into environmental conditions influencing hybridization dynamics between

  17. Probing the structure and function of biopolymer-carbon nanotube hybrids with molecular dynamics

    Science.gov (United States)

    Johnson, Robert R.

    2009-12-01

    Nanoscience deals with the characterization and manipulation of matter on the atomic/molecular size scale in order to deepen our understanding of condensed matter and develop revolutionary technology. Meeting the demands of the rapidly advancing nanotechnological frontier requires novel, multifunctional nanoscale materials. Among the most promising nanomaterials to fulfill this need are biopolymer-carbon nanotube hybrids (Bio-CNT). Bio-CNT consists of a single-walled carbon nanotube (CNT) coated with a self-assembled layer of biopolymers such as DNA or protein. Experiments have demonstrated that these nanomaterials possess a wide range of technologically useful properties with applications in nanoelectronics, medicine, homeland security, environmental safety and microbiology. However, a fundamental understanding of the self-assembly mechanics, structure and energetics of Bio-CNT is lacking. The objective of this thesis is to address this deficiency through molecular dynamics (MD) simulation, which provides an atomic-scale window into the behavior of this unique nanomaterial. MD shows that Bio-CNT composed of single-stranded DNA (ssDNA) self-assembles via the formation of high affinity contacts between DNA bases and the CNT sidewall. Calculation of the base-CNT binding free energy by thermodynamic integration reveals that these contacts result from the attractive pi--pi stacking interaction. Binding affinities follow the trend G > A > T > C. MD reveals that long ssDNA sequences are driven into a helical wrapping about CNT with a sub-10 nm pitch by electrostatic and torsional interactions in the backbone. A large-scale replica exchange molecular dynamics simulation reveals that ssDNA-CNT hybrids are disordered. At room temperature, ssDNA can reside in several low-energy conformations that contain a sequence-specific arrangement of bases detached from CNT surface. MD demonstrates that protein-CNT hybrids composed of the Coxsackie-adenovirus receptor are biologically

  18. Genetic structure of Populus hybrid zone along the Irtysh River provides insight into plastid-nuclear incompatibility.

    Science.gov (United States)

    Zeng, Yan-Fei; Zhang, Jian-Guo; Duan, Ai-Guo; Abuduhamiti, Bawerjan

    2016-06-16

    In plants, the maintenance of species integrity despite hybridization has often been explained by the co-adaption of nuclear gene complexes. However, the interaction between plastid and nuclear sub-genomes has been underestimated. Here, we analyzed the genetic structure of a Populus alba and P. tremula hybrid zone along the Irtysh River system in the Altai region, northwest China, using both nuclear microsatellites and plastid DNA sequences. We found high interspecific differentiation, although the hybrid P. × canescens was prevalent. Bayesian inference classified most hybrids into F1, followed by a few back-crosses to P. alba, and fewer F2 hybrids and back-crosses to P. tremula, indicating a few introgressions but preference toward P. alba. When plastid haplotypes in parental species were distinct, P. × canescens carried the haplotypes of both parents, but showed significant linkage between intraspecific haplotype and nuclear genotypes at several microsatellite loci. Selection, rather than migration and assortative mating, might have contributed to such plastid-nuclear disequilibria. By removing later-generated hybrids carrying interspecific combinations of haplotype and nuclear genotypes, plastid-nuclear incompatibility has greatly limited the gene exchange between P. alba and P. tremula via backcrossing with hybrids, demonstrating a significant association between plastid haplotype and the proportion of nuclear admixture.

  19. Solitary Dunes under Bimodal Winds

    Science.gov (United States)

    Reffet, Erwan; Courrech du Pont, S.; Hersen, P.; Fulchignoni, M.; Douady, S.

    2009-01-01

    The high resolution and coverage achieved on Mars' surface have detailed lots of sand dunes of various types [1]. Many are reported as barchan or barchanoid dunes and present a diversity of shape ascribed to compound wind regimes, collisions or cementation. This diversity reminds us that aeolian structures are fairly complex. Although dunes have been extensively observed and documented, the conditions of their formation and evolution are still difficult to study because of the long time required for their development and their large length-scale. We developed a laboratory approach using underwater experiments to study the morphology of dunes. This method has been used successfully to reproduce various types of dunes downsized to a few centimeters. Barchan dunes are formed using a unidirectional wind-equivalent regime on a pile of ceramic sand-sized grains [2]. Changing the wind regime to a more complex one reveals other structures. In the case of multiple wind directions star dunes can be observed. A bimodal wind regime, e.g. switching between two distinct directions, over an homogeneous layer of sand leads to transverse, longitudinal or complex compound sandbeds depending on the angle between these wind directions [3]. Here, we apply bimodal wind regimes to isolated patches of sand in order to observe the variation of morphology of the resulting dunes. We present the barchanoid dunes obtained for various angles of bimodal wind and show the transition to the "chestnut” dunes type. We also investigate sudden variations in wind direction over a barchan dune. Therefore, we illustrate how the (not so) simple barchan shape can be affected by a more complex wind regime and give a new insight in understanding dunes on Mars. [1] http://www.mars-dunes.org/ . [2] Hersen et al. PRL, 2003. [3] Reffet et al. pldu.work 2008.

  20. Structural effect of monomer type on properties of copolyimides and copolyimide-silica hybrid materials

    Directory of Open Access Journals (Sweden)

    Kizilkaya Canan

    2015-01-01

    Full Text Available In this work, the effect of two different diamine monomers, containing phosphine oxide, on thermal, mechanical and morphological properties of copolyimides and their hybrid materials was investigated. Gas separation properties of the synthesized copolyimides were also analysed. Two different diamine monomers with phosphine oxide were bis(3-aminophenyl phenylphosphine oxide (BAPPO and bis(3-aminophenoxy-4-phenyl phenylphosphine oxide (m-BAPPO. In the synthesis of copolyimides 3,3’-diamino-diphenyl sulfone (DDS was also used as the diamine, as well as 2,2’-bis(3,4-dicarboxyphenylhexafluoropropane dianhydride (6FDA. Copolyimide films were prepared by thermal imidization. Hybrid materials containing 5 % SiO2 were synthesised further by sol-gel technique. The Fourier-transform infrared spectroscopy (FTIR, Nuclear magnetic resonance spectroscopy (NMR confirmed the expected structure. Dynamic mechanical analysis (DMA demonstrated that m-BAPPO based copolyimides had lower glass transition temperatures (Tg than BAPPO based copolyimides. m-BAPPO containing copolyimide without silica shifted the thermal decomposition temperature to a higher value. The moduli and strength values of BAPPO diamine containing copolyimide and its hybrid were higher than those of m-BAPPO containing materials. The contact angle measurements showed the hydrophobicity. Scanning electron microscope (SEM analysis exhibited the silica particles dispersion in the copolyimides. These copolyimides may be used in the coating industry. The CO2 permeability and the permselectivity were the highest among the other values in this study, when m-BAPPO containing copolyimide in the absence of silica was used. The gas permeabilities obtained from this work were in this decreasing order: PCO2 > PO2 > PN2.

  1. HOST SPECIFICITY AND THE GENETIC STRUCTURE OF TWO YUCCA MOTH SPECIES IN A YUCCA HYBRID ZONE.

    Science.gov (United States)

    Leebens-Mack, Jim; Pellmyr, Olle; Brock, Marcus

    1998-10-01

    Host specialization is an important mechanism of diversification among phytophagous insects, especially when they are tightly associated with their hosts. The well-known obligate pollination mutualism between yucca moths and yuccas represent such an association, but the degree of host specificity and modes of specialization in moth evolution is unclear. Here we use molecular tools to test the morphology-based hypothesis that the moths pollinating two yuccas, Yucca baccata and Y. schidigera, are distinct species. Host specificity was assessed in a zone of sympatry where the hosts are known to hybridize. Because the moths are the only pollinators, the plant hybrids are evidence that the moths occasionally perform heterospecific pollination. Nucleotide variation was assessed in a portion of the mitochondrial gene COI, and in an intron within a nuclear lysozyme gene. Moths pollinating Y. baccata and Y. schidigera were inferred to be genetically isolated because there was no overlap in alleles at either locus, and all but one of the moths was found on their native host in the hybrid zone. Moreover, genetic structure was very weak across the range of each moth species: estimates of FST for the lysozyme intron were 0.043 (SE = ± 0.004) and 0.021 (SE = ± 0.006) for the baccata and schidigera pollinators, respectively; estimated FST for COI in the baccata moths was 0.228 (± 0.012), whereas schidigera pollinators were fixed for a single allele. These results reveal a high level of migration among widely separated moth populations. We predict that pollen-mediated gene flow among conspecific yuccas is considerable and hypothesize that geographic separation is a limited barrier both for yuccas and for yucca moths. © 1998 The Society for the Study of Evolution.

  2. Structural hybrid reliability index and its convergent solving method based on random–fuzzy–interval reliability model

    Directory of Open Access Journals (Sweden)

    Hai An

    2016-08-01

    Full Text Available Aiming to resolve the problems of a variety of uncertainty variables that coexist in the engineering structure reliability analysis, a new hybrid reliability index to evaluate structural hybrid reliability, based on the random–fuzzy–interval model, is proposed in this article. The convergent solving method is also presented. First, the truncated probability reliability model, the fuzzy random reliability model, and the non-probabilistic interval reliability model are introduced. Then, the new hybrid reliability index definition is presented based on the random–fuzzy–interval model. Furthermore, the calculation flowchart of the hybrid reliability index is presented and it is solved using the modified limit-step length iterative algorithm, which ensures convergence. And the validity of convergent algorithm for the hybrid reliability model is verified through the calculation examples in literature. In the end, a numerical example is demonstrated to show that the hybrid reliability index is applicable for the wear reliability assessment of mechanisms, where truncated random variables, fuzzy random variables, and interval variables coexist. The demonstration also shows the good convergence of the iterative algorithm proposed in this article.

  3. Hybrid Group IV Nanophotonic Structures Incorporating Diamond Silicon-Vacancy Color Centers.

    Science.gov (United States)

    Zhang, Jingyuan Linda; Ishiwata, Hitoshi; Babinec, Thomas M; Radulaski, Marina; Müller, Kai; Lagoudakis, Konstantinos G; Dory, Constantin; Dahl, Jeremy; Edgington, Robert; Soulière, Veronique; Ferro, Gabriel; Fokin, Andrey A; Schreiner, Peter R; Shen, Zhi-Xun; Melosh, Nicholas A; Vučković, Jelena

    2016-01-13

    We demonstrate a new approach for engineering group IV semiconductor-based quantum photonic structures containing negatively charged silicon-vacancy (SiV(-)) color centers in diamond as quantum emitters. Hybrid diamond-SiC structures are realized by combining the growth of nano- and microdiamonds on silicon carbide (3C or 4H polytype) substrates, with the subsequent use of these diamond crystals as a hard mask for pattern transfer. SiV(-) color centers are incorporated in diamond during its synthesis from molecular diamond seeds (diamondoids), with no need for ion-implantation or annealing. We show that the same growth technique can be used to grow a diamond layer controllably doped with SiV(-) on top of a high purity bulk diamond, in which we subsequently fabricate nanopillar arrays containing high quality SiV(-) centers. Scanning confocal photoluminescence measurements reveal optically active SiV(-) lines both at room temperature and low temperature (5 K) from all fabricated structures, and, in particular, very narrow line widths and small inhomogeneous broadening of SiV(-) lines from all-diamond nanopillar arrays, which is a critical requirement for quantum computation. At low temperatures (5 K) we observe in these structures the signature typical of SiV(-) centers in bulk diamond, consistent with a double lambda. These results indicate that high quality color centers can be incorporated into nanophotonic structures synthetically with properties equivalent to those in bulk diamond, thereby opening opportunities for applications in classical and quantum information processing.

  4. Shake table testing of a multi-tower connected hybrid structure

    Institute of Scientific and Technical Information of China (English)

    Zhou Ying; Lu Xilin; Lu Wensheng; He Zhijun

    2009-01-01

    Many single-tower reinforced concrete core wall-steel frame (RCC-SF) buildings have been built in China, but there are no buildings of different-height multi-tower hybrid system. A multi-tower RCC-SF tall building was thus studied because of its structural complexity and irregularity. First, a 1/15 scaled model structure was designed and tested on the shake table under minor, moderate, and major earthquake levels. Then, the dynamic responses of the model structure were interpreted to those of the prototype structure according to the similitude theory. Experimental results demonstrate that, despite the complexity of the structure, the lateral deformation bends as the "bending type" and the RC core walls contribute more than the steel frames to resist seismic loads. The maximum inter-story drift of the complex building under minor earthquakes is slightly beyond the elastic limitation specified in the Chinese code, and meets code requirements under major earthquakes. From the test results some suggestions are provided that could contribute favorable effect on the seismic behavior and the displacement of the building.

  5. 2D-ordered dielectric sub-micron bowls on a metal surface: a useful hybrid plasmonic-photonic structure

    Science.gov (United States)

    Lan, Yue; Wang, Shiqiang; Yin, Xianpeng; Liang, Yun; Dong, Hao; Gao, Ning; Li, Jian; Wang, Hui; Li, Guangtao

    2016-07-01

    Recently, it has been demonstrated that the combination of periodic dielectric structures with metallic structures provides an efficient means to yield a synergetic optical response or functionality in the resultant hybrid plasmonic-photonic systems. In this work, a new hybrid plasmonic-photonic structure of 2D-ordered dielectric sub-micron bowls on a flat gold surface was proposed, prepared, and theoretically and experimentally characterized. This hybrid structure supports two types of modes: surface plasmon polaritons bound at the metallic surface and waveguided mode of light confined in the cavity of bowls. Optical responses of this hybrid structure as well as the spatial electric field distribution of each mode are found to be strongly dependent on the structural parameters of this system, and thus could be widely modified on demand. Importantly, compared to the widely studied hybrid systems, namely the flat metallic surface coated with a monolayer array of latex spheres, the waveguided mode with strong field enhancement appearing in the cavities of bowls is more facilely accessible and thus suitable for practical use. For demonstration, a 2D-ordered silica sub-micron bowl array deposited on a flat gold surface was fabricated and used as a regenerable platform for fluorescence enhancement by simply accommodating emitters in bowls. All the simulation and experiment results indicate that the 2D-ordered dielectric sub-micron bowls on a metal surface should be a useful hybrid plasmonic-photonic system with great potential for applications such as sensors or tunable emitting devices if appropriate periods and materials are employed.Recently, it has been demonstrated that the combination of periodic dielectric structures with metallic structures provides an efficient means to yield a synergetic optical response or functionality in the resultant hybrid plasmonic-photonic systems. In this work, a new hybrid plasmonic-photonic structure of 2D-ordered dielectric sub

  6. Electron Bernstein-Greene-Kruskal hole for obliquely propagating solitary kinetic Alfvén waves

    Science.gov (United States)

    Woo, M.-H.; Dokgo, K.; Yoon, Peter H.; Lee, D.-Y.; Choi, Cheong R.

    2017-04-01

    A possible formation of an electron hole structure associated with an obliquely propagating solitary kinetic Alfvén wave (SKAW) in a strongly magnetized plasma is discussed. It is found that transverse electric field along the magnetic field plays a key role in the electron phase space hole formation. Owing to the presence of trapped electrons, SKAW can propagate in both super-Alfvénic and sub-Alfvénic regimes with different spatial structures. In particular, in the sub-Alfvénic case, the density perturbation possesses a dip at the center accompanied by a pair of humps at the edges. Such a feature may be relevant to satellite observation of solitary structures in the Earth's geomagnetic tail region.

  7. Asymptotic Methods for Solitary Solutions and Compactons

    Directory of Open Access Journals (Sweden)

    Ji-Huan He

    2012-01-01

    Full Text Available This paper is an elementary introduction to some new asymptotic methods for the search for the solitary solutions of nonlinear differential equations, nonlinear differential-difference equations, and nonlinear fractional differential equations. Particular attention is paid throughout the paper to giving an intuitive grasp for the variational approach, the Hamiltonian approach, the variational iteration method, the homotopy perturbation method, the parameter-expansion method, the Yang-Laplace transform, the Yang-Fourier transform, and ancient Chinese mathematics. Hamilton principle and variational principles are also emphasized. The reviewed asymptotic methods are easy to be followed for various applications. Some ideas on this paper are first appeared.

  8. Solitary lucent epiphyseal lesions in children

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, D.J.; Azouz, E.M.

    1988-10-01

    We evaluated retrospectively the varying radiographic appearances of 15 solitary lucent epiphyseal lesions occurring in children. Imaging modalities used included plain films, conventional tomography, nuclear scintigraphy, and computed tomography. 40% of the lesions (6) were due to osteomyelitis. The remaining lesions included tuberculosis (1), foreign body granuloma (1), chondroblastoma (2), chondromyoxid fibroma (1), enchondroma (1), osteoid osteoma (2), and eosinophilic granuloma (1). Although the radiographic appearances of such lesions may be particularly characteristic, pathologic correlation is frequently necessary. The high incidence of osteomyelitis in our cases emphasizes its importance as a cause for a lucent epiphyseal lesion.

  9. [Solitary naso-sinusal fibrous tumor].

    Science.gov (United States)

    Martínez, V; Jiménez, M L; Cuatrecasas, M; Jürgens, A; de Amesti, C; Orus, C; Fabra, J M

    1995-01-01

    Here we present two clinical cases of solitary naso-sinusal fibrous tumour. This tumour has a mesenchymal origin and has an evident pleural location, with well defined immunohistochemical and ultrastructural characteristics. The clinical manifestation is an apparent benign tumour with an inclination to local aggressiveness. The most effective treatment seems to be surgical removal, but given the low number of cases mentioned (there are only eight cases reported in international literature), and the tendency to eventual recurrence, called for cobalt therapy after surgery. The evolution of clinical cases is irregular.

  10. 2D-ordered dielectric sub-micron bowls on a metal surface: a useful hybrid plasmonic-photonic structure.

    Science.gov (United States)

    Lan, Yue; Wang, Shiqiang; Yin, Xianpeng; Liang, Yun; Dong, Hao; Gao, Ning; Li, Jian; Wang, Hui; Li, Guangtao

    2016-07-21

    Recently, it has been demonstrated that the combination of periodic dielectric structures with metallic structures provides an efficient means to yield a synergetic optical response or functionality in the resultant hybrid plasmonic-photonic systems. In this work, a new hybrid plasmonic-photonic structure of 2D-ordered dielectric sub-micron bowls on a flat gold surface was proposed, prepared, and theoretically and experimentally characterized. This hybrid structure supports two types of modes: surface plasmon polaritons bound at the metallic surface and waveguided mode of light confined in the cavity of bowls. Optical responses of this hybrid structure as well as the spatial electric field distribution of each mode are found to be strongly dependent on the structural parameters of this system, and thus could be widely modified on demand. Importantly, compared to the widely studied hybrid systems, namely the flat metallic surface coated with a monolayer array of latex spheres, the waveguided mode with strong field enhancement appearing in the cavities of bowls is more facilely accessible and thus suitable for practical use. For demonstration, a 2D-ordered silica sub-micron bowl array deposited on a flat gold surface was fabricated and used as a regenerable platform for fluorescence enhancement by simply accommodating emitters in bowls. All the simulation and experiment results indicate that the 2D-ordered dielectric sub-micron bowls on a metal surface should be a useful hybrid plasmonic-photonic system with great potential for applications such as sensors or tunable emitting devices if appropriate periods and materials are employed.

  11. Structure of biomembrane-on-silicon hybrids derived from X-ray reflectometry

    Energy Technology Data Exchange (ETDEWEB)

    Birkholz, M. [IHP, Im Technologiepark 25, D-15236 Frankfurt (Germany)]. E-mail: birkholz@ihp-microelectronics.com; Zaumseil, P. [IHP, Im Technologiepark 25, D-15236 Frankfurt (Germany); Kittler, M. [IHP, Im Technologiepark 25, D-15236 Frankfurt (Germany); Wallat, I. [Fachbereich Physik, FU Berlin, Arnimallee 14, D-14195 Berlin (Germany); Heyn, M.P. [Fachbereich Physik, FU Berlin, Arnimallee 14, D-14195 Berlin (Germany)

    2006-10-15

    The organic-inorganic interface and its proper structural adjustment are of central importance for the fabrication of hybrid material systems from biomolecules and semiconductors. Such material hybrids are currently under development for several advanced applications, in particular for biomolecular sensing. An investigation of biomolecular immobilization on semiconductor surfaces by X-ray reflectometry (XRR) will be presented. Complete biomembrane patches of purple membrane (PM) from Halobacterium salinarum were immobilized on oxidized and nitrided silicon wafers. A covalent immobilization protocol based on 3-aminopropyltriethoxysilane (APTS) and glutaric dialdehyde (GD) was applied for cross-linking the biomolecules to the semiconductor surface. XRR could be shown to yield the relevant morphological parameters of biomolecular monolayers such as layer thickness, interface roughness and coverage. Synchrotron radiation was not required, but a laboratory rotating anode set-up was sufficient to study the prepared stacking of organic monolayers. According to the measurement and analysis of XRR patterns both cross-linking layers APTS and GD are required for bonding purple membrane patches to SiO{sub 2}/Si, whereas GD alone suffices for cross-linking to Si{sub 3}N{sub 4}/Si. This distinct behavior offers a pathway for nanopatterning of biomolecules on Si surfaces by selective passivation.

  12. Hybrid carbon fiber/carbon nanotube composites for structural damping applications

    Science.gov (United States)

    Tehrani, M.; Safdari, M.; Boroujeni, A. Y.; Razavi, Z.; Case, S. W.; Dahmen, K.; Garmestani, H.; Al-Haik, M. S.

    2013-04-01

    Carbon nanotubes (CNTs) were grown on the surface of carbon fibers utilizing a relatively low temperature synthesis technique; graphitic structures by design (GSD). To probe the effects of the synthesis protocols on the mechanical properties, other samples with surface grown CNTs were prepared using catalytic chemical vapor deposition (CCVD). The woven graphite fabrics were thermally shielded with a thin film of SiO2 and CNTs were grown on top of this film. Raman spectroscopy and electron microscopy revealed the grown species to be multi-walled carbon nanotubes (MWCNTs). The damping performance of the hybrid CNT-carbon fiber-reinforced epoxy composite was examined using dynamic mechanical analysis (DMA). Mechanical testing confirmed that the degradations in the strength and stiffness as a result of the GSD process are far less than those encountered through using the CCVD technique and yet are negligible compared to the reference samples. The DMA results indicated that, despite the minimal degradation in the storage modulus, the loss tangent (damping) for the hybrid composites utilizing GSD-grown MWCNTs improved by 56% compared to the reference samples (based on raw carbon fibers with no surface treatment or surface grown carbon nanotubes) over the frequency range 1-60 Hz. These results indicated that the energy dissipation in the GSD-grown MWCNTs composite can be primarily attributed to the frictional sliding at the nanotube/epoxy interface and to a lesser extent to the stiff thermal shielding SiO2 film on the fiber/matrix interface.

  13. In Situ Synthesis of Bimetallic Hybrid Nanocatalysts on a Paper-Structured Matrix for Catalytic Applications

    Directory of Open Access Journals (Sweden)

    Hirotaka Koga

    2011-11-01

    Full Text Available Bimetallic nanoparticles have attracted significant attention as their electrochemical and catalytic properties being superior to those of the individual component nanoparticles. In this study, gold-silver hybrid nanoparticles (AuAgNPs with an Aucore-Agshell nanostructure were successfully synthesized on zinc oxide (ZnO whiskers. The as-prepared nanocatalyst, denoted AuAgNPs@ZnO whisker, exhibits an excellent catalytic efficiency in the aqueous reduction of 4-nitrophenol to 4-aminophenol; the turnover frequency was up to 40 times higher than that of each component nanoparticle. Their unique features were attributed to the electronic ligand effect at the bimetallic interface. In addition, the AuAgNPs were synthesized on a ZnO whisker-containing paper with a fiber-network microstructure, which was prepared via a papermaking technique. The paper-structured AuAgNPs composite possessed both a paper-like practical utility and a good catalytic performance. Furthermore, the on-paper synthesis process for these bimetallic nanocatalysts is facile. These easy-to-handle nanocatalyst hybrid composites are expected to find a wide range of applications in various chemical and catalytic processes.

  14. The atomic structure of ternary amorphous TixSi1-xO2 hybrid oxides.

    Science.gov (United States)

    Landmann, M; Köhler, T; Rauls, E; Frauenheim, T; Schmidt, W G

    2014-06-25

    Atomic length-scale order characteristics of binary and ternary amorphous oxides are presented within the framework of ab initio theory. A combined numerically efficient density functional based tight-binding molecular dynamics and density functional theory approach is applied to model the amorphous (a) phases of SiO2 and TiO2 as well as the amorphous phase of atomically mixed TixSi1-xO2 hybrid-oxide alloys over the entire composition range. Short and mid-range order in the disordered material phases are characterized by bond length and bond-angle statistics, pair distribution function analysis, coordination number and coordination polyhedra statistics, as well as ring statistics. The present study provides fundamental insights into the order characteristics of the amorphous hybrid-oxide frameworks formed by versatile types of TiOn and SiOm coordination polyhedra. In a-SiO2 the fourfold crystal coordination of Si ions is almost completely preserved and the atomic structure is widely dominated by ring-like mid-range order characteristics. In contrast, the structural disorder of a-TiO2 arises from short-range disorder in the local coordination environment of the Ti ion. The coordination number analysis indicates a large amount of over and under-coordinated Ti ions (coordination defects) in a-TiO2. Aside from the ubiquitous distortions of the crystal-like coordinated polyhedra, even the basic coordination-polyhedra geometry type changes for a significant fraction of TiO6 units (geometry defects). The combined effects of topological and chemical disorder in a-TixSi1-xO2 alloys lead to a continuos increase in both the Si as well as the Ti coordination number with the chemical composition x. The important roles of intermediate fivefold coordination states of Ti and Si cations are highlighted for ternary a-TixSi1-xO2 as well as for binary a-TiO2. The continuous decrease in ring size with increasing Ti content reflects the progressive loss of mid-range order structure

  15. Study on Solitary Waves of a General Boussinesq Model

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, we employ the bifurcation method of dynamical systems to study the solitary waves and periodic waves of a generalized Boussinesq equations. All possible phase portraits in the parameter plane for the travelling wave systems are obtained. The possible solitary wave solutions, periodic wave solutions and cusp waves for the general Boussinesq type fluid model are also investigated.

  16. What, if anything, are hybrids: enduring truths and challenges associated with population structure and gene flow

    OpenAIRE

    Gompert, Zachariah; Buerkle, C Alex

    2016-01-01

    Abstract Hybridization is a potent evolutionary process that can affect the origin, maintenance, and loss of biodiversity. Because of its ecological and evolutionary consequences, an understanding of hybridization is important for basic and applied sciences, including conservation biology and agriculture. Herein, we review and discuss ideas that are relevant to the recognition of hybrids and hybridization. We supplement this discussion with simulations. The ideas we present have a long histor...

  17. Neuronal, non-neuronal and hybrid forms of enolase in brain: structural, immunological and functional comparisons.

    Science.gov (United States)

    Marangos, P J; Zis, A P; Clark, R L; Goodwin, F K

    1978-07-07

    Three forms of the glycolytic enzyme, enolase [2-phospho-D-glycerate hydrolase (E.C. No. 4.2.1.11)] have been prepared from rat whole brain extract. The most acidic enolase form is neuron specific enolase (NSE) which had previously been designated neuron specific protein (NSP). The least acidic form designated non-neuronal enolase (NNE) has been purified and compared structurally, immunologically and functionally to NSE. NNE is a dimer of 86,500 M.W. consistint of two very similar subunits. The data establish that NNE is larger than NSE which has been shown to be composed of two apparently identical 39,000 molecular weight subunits (78,000). NNE is less acidic than NSE having a pI of 5.9 compared to the value of 4.7 for NSE. Structural and immunological analysis establishes that the NNE subunit is distinct from the NSE subunit, and are therfore products of two separate genes. The structural designation of NSE is (gammagamma) and that of NNE (alpha' alpha'). NSE is strictly localized in neurons indicating that the gene coding for the gamma subunit is only expressed in neuronal cells. The intermediate brain enolase form has been partially purified; structural and immunological evidence indicate that it is a hybrid molecule consisting of one NNE subunit and one NSE subunit (alpha'gamma).

  18. Update on HCDstruct - A Tool for Hybrid Wing Body Conceptual Design and Structural Optimization

    Science.gov (United States)

    Gern, Frank H.

    2015-01-01

    HCDstruct is a Matlab® based software tool to rapidly build a finite element model for structural optimization of hybrid wing body (HWB) aircraft at the conceptual design level. The tool uses outputs from a Flight Optimization System (FLOPS) performance analysis together with a conceptual outer mold line of the vehicle, e.g. created by Vehicle Sketch Pad (VSP), to generate a set of MSC Nastran® bulk data files. These files can readily be used to perform a structural optimization and weight estimation using Nastran’s® Solution 200 multidisciplinary optimization solver. Initially developed at NASA Langley Research Center to perform increased fidelity conceptual level HWB centerbody structural analyses, HCDstruct has grown into a complete HWB structural sizing and weight estimation tool, including a fully flexible aeroelastic loads analysis. Recent upgrades to the tool include the expansion to a full wing tip-to-wing tip model for asymmetric analyses like engine out conditions and dynamic overswings, as well as a fully actuated trailing edge, featuring up to 15 independently actuated control surfaces and twin tails. Several example applications of the HCDstruct tool are presented.

  19. Exact solitary wave solutions of nonlinear wave equations

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The hyperbolic function method for nonlinear wave equations ispresented. In support of a computer algebra system, many exact solitary wave solutions of a class of nonlinear wave equations are obtained via the method. The method is based on the fact that the solitary wave solutions are essentially of a localized nature. Writing the solitary wave solutions of a nonlinear wave equation as the polynomials of hyperbolic functions, the nonlinear wave equation can be changed into a nonlinear system of algebraic equations. The system can be solved via Wu Elimination or Grbner base method. The exact solitary wave solutions of the nonlinear wave equation are obtained including many new exact solitary wave solutions.

  20. Synthesis and structural characterization of piperazino-modified DNA that favours hybridization towards DNA over RNA

    DEFF Research Database (Denmark)

    Skov, Joan; Bryld, Torsten; Lindegaard, Dorthe

    2011-01-01

    We report the synthesis of two C4'-modified DNA analogues and characterize their structural impact on dsDNA duplexes. The 4'-C-piperazinomethyl modification stabilizes dsDNA by up to 5°C per incorporation. Extension of the modification with a butanoyl-linked pyrene increases the dsDNA stabilization...... modifications are tolerated in DNA:RNA hybrids but leave their melting temperatures virtually unaffected. Fluorescence data indicate that the pyrene moiety is residing outside the helix. The available data suggest that the DNA discrimination is due to (i) the positive charge of the piperazino ring having...... to a maximum of 9°C per incorporation. Using fluorescence, ultraviolet and nuclear magnetic resonance (NMR) spectroscopy, we show that the stabilization is achieved by pyrene intercalation in the dsDNA duplex. The pyrene moiety is not restricted to one intercalation site but rather switches between multiple...

  1. A millisecond micro-RNA separation technique by a hybrid structure of nanopillars and nanoslits.

    Science.gov (United States)

    Wu, Qiong; Kaji, Noritada; Yasui, Takao; Rahong, Sakon; Yanagida, Takeshi; Kanai, Masaki; Nagashima, Kazuki; Tokeshi, Manabu; Kawai, Tomoji; Baba, Yoshinobu

    2017-03-08

    A millisecond micro-RNA separation of a mixture of total RNA and genomic DNA, extracted from cultured HeLa cells, was successfully achieved using a hybrid structure of nanopillars and nanoslits contained inside a microchannel. The nanopillars, 250-nm in diameter and 100-nm in height, were fabricated with a 750-nm space inside the nanoslits, which were 100-nm in height and 25-μm in width; the nanopillars were then applied as a new sieve matrix. This ultra-fast technique for the separation of miRNA can be an effective pretreatment for semiconductor nanopore DNA sequencing, which has an optimum reading speed of 1 base/ms to obtain effective signal-to-noise ratio and discriminate each base by ion or tunneling current during the passage of nucleic acids.

  2. 16-QAM Quantum Receiver with Hybrid Structure Outperforming the Standard Quantum Limit

    Directory of Open Access Journals (Sweden)

    Zuo Yuan

    2016-01-01

    Full Text Available Quantum receivers which can discriminate phase shift keying (PSK and pulse position modulation (PPM signals below the standard quantum limit have been proposed and some have been demonstrated experimentally. But for quadrature amplitude modulation (QAM signals, few literatures have been reported so far. It is important to reduce the average error probability of QAM signals below the standard quantum limit (SQL, since these modulation have a high spectral efficiency. In this paper, we present a quantum receiver for 16-QAM signals discrimination with hybrid structure, which contains a homodyne receiver and a displacement receiver. By numerical simulation, we prove that the performance of the quantum receiver can outperform the SQL, and it can be improved by an optimized displacement.

  3. Structural Characterization and Infrared and Electrical Properties of the New Inorganic-Organic Hybrid Compound

    Directory of Open Access Journals (Sweden)

    A. Oueslati

    2013-01-01

    Full Text Available New inorganic-organic hybrid [(C3H74N]2Hg2Cl6 compound was obtained and characterised by single-crystal X-ray diffraction, infrared, and impedance spectroscopy. The latter crystallizes in the monoclinic system (space group C 2/c, with the following unit cell dimensions: (1 Å, (6 Å, (2 Å, and (2. Besides, its structure was solved using 84860 independent reflections leading to . Electrical properties of the material were studied using impedance spectroscopic technique at different temperatures in the frequency range of 209 Hz to 5 MHz. Detailed analysis of the impedance spectrum suggested that the electrical properties of the material are strongly temperature-dependent. The Nyquist plots clearly showed the presence of bulk and grain boundary effect in the compound.

  4. Hybrid microfiber-lithium-niobate nanowaveguide structures as high-purity heralded single-photon sources

    Science.gov (United States)

    Main, Philip; Mosley, Peter J.; Ding, Wei; Zhang, Lijian; Gorbach, Andrey V.

    2016-12-01

    We propose a compact, fiber-integrated architecture for photon-pair generation by parametric downconversion with unprecedented flexibility in the properties of the photons produced. Our approach is based on a thin-film lithium niobate nanowaveguide, evanescently coupled to a tapered silica microfiber. We demonstrate how controllable mode hybridization between the fiber and waveguide yields control over the joint spectrum of the photon pairs. We also investigate how independent engineering of the linear and nonlinear properties of the structure can be achieved through the addition of a tapered, proton-exchanged layer to the waveguide. This allows further refinement of the joint spectrum through custom profiling of the effective nonlinearity, drastically improving the purity of the heralded photons. We give details of a source design capable of generating heralded single photons in the telecom wavelength range with purity of at least 0.95, and we provide a feasible fabrication methodology.

  5. LDH dye hybrid material as coloured filler into polystyrene: Structural characterization and rheological properties

    Science.gov (United States)

    Taviot-Gueho, C.; Illaik, A.; Vuillermoz, C.; Commereuc, S.; Verney, V.; Leroux, F.

    2007-05-01

    The organic inorganic hybrid assembly composed of a dye molecule of large size, direct yellow®50, as interleaved anionic molecule and layered double hydroxide host was investigated by X-ray diffraction. Upon hydrothermal post-synthesis treatment, the basal spacing is strongly decreased, explained by a drastic change in the orientation of the organic molecule against the LDH sheets, from perpendicular to parallel. The interactions were studied by 13C CPMAS NMR technique. Dispersed into polystyrene, the coloured filler was found to behave better in the viscoelastic domain than conventional surfactant LDH filler, maintaining similar rheological properties to filler-free PS. We demonstrate here that an intercalated nanocomposite polymer structure, providing an additional function as colour, is not preposterous.

  6. A hybrid design methodology for structuring an Integrated Environmental Management System (IEMS) for shipping business.

    Science.gov (United States)

    Celik, Metin

    2009-03-01

    The International Safety Management (ISM) Code defines a broad framework for the safe management and operation of merchant ships, maintaining high standards of safety and environmental protection. On the other hand, ISO 14001:2004 provides a generic, worldwide environmental management standard that has been utilized by several industries. Both the ISM Code and ISO 14001:2004 have the practical goal of establishing a sustainable Integrated Environmental Management System (IEMS) for shipping businesses. This paper presents a hybrid design methodology that shows how requirements from both standards can be combined into a single execution scheme. Specifically, the Analytic Hierarchy Process (AHP) and Fuzzy Axiomatic Design (FAD) are used to structure an IEMS for ship management companies. This research provides decision aid to maritime executives in order to enhance the environmental performance in the shipping industry.

  7. A hybrid algorithm for selecting head-related transfer function based on similarity of anthropometric structures

    Science.gov (United States)

    Zeng, Xiang-Yang; Wang, Shu-Guang; Gao, Li-Ping

    2010-09-01

    As the basic data for virtual auditory technology, head-related transfer function (HRTF) has many applications in the areas of room acoustic modeling, spatial hearing and multimedia. How to individualize HRTF fast and effectively has become an opening problem at present. Based on the similarity and relativity of anthropometric structures, a hybrid HRTF customization algorithm, which has combined the method of principal component analysis (PCA), multiple linear regression (MLR) and database matching (DM), has been presented in this paper. The HRTFs selected by both the best match and the worst match have been applied into obtaining binaurally auralized sounds, which are then used for subjective listening experiments and the results are compared. For the area in the horizontal plane, the localization results have shown that the selection of HRTFs can enhance the localization accuracy and can also abate the problem of front-back confusion.

  8. A millisecond micro-RNA separation technique by a hybrid structure of nanopillars and nanoslits

    Science.gov (United States)

    Wu, Qiong; Kaji, Noritada; Yasui, Takao; Rahong, Sakon; Yanagida, Takeshi; Kanai, Masaki; Nagashima, Kazuki; Tokeshi, Manabu; Kawai, Tomoji; Baba, Yoshinobu

    2017-01-01

    A millisecond micro-RNA separation of a mixture of total RNA and genomic DNA, extracted from cultured HeLa cells, was successfully achieved using a hybrid structure of nanopillars and nanoslits contained inside a microchannel. The nanopillars, 250-nm in diameter and 100-nm in height, were fabricated with a 750-nm space inside the nanoslits, which were 100-nm in height and 25-μm in width; the nanopillars were then applied as a new sieve matrix. This ultra-fast technique for the separation of miRNA can be an effective pretreatment for semiconductor nanopore DNA sequencing, which has an optimum reading speed of 1 base/ms to obtain effective signal-to-noise ratio and discriminate each base by ion or tunneling current during the passage of nucleic acids. PMID:28272420

  9. The lifecycle of axisymmetric internal solitary waves

    Directory of Open Access Journals (Sweden)

    J. M. McMillan

    2010-09-01

    Full Text Available The generation and evolution of solitary waves by intrusive gravity currents in an approximate two-layer fluid with equal upper- and lower-layer depths is examined in a cylindrical geometry by way of theory and numerical simulations. The study is limited to vertically symmetric cases in which the density of the intruding fluid is equal to the average density of the ambient. We show that even though the head height of the intrusion decreases, it propagates at a constant speed well beyond 3 lock radii. This is because the strong stratification at the interface supports the formation of a mode-2 solitary wave that surrounds the intrusion head and carries it outwards at a constant speed. The wave and intrusion propagate faster than a linear long wave; therefore, there is strong supporting evidence that the wave is indeed nonlinear. Rectilinear Korteweg-de Vries theory is extended to allow the wave amplitude to decay as r-p with p=½ and the theory is compared to the observed waves to demonstrate that the width of the wave scales with its amplitude. After propagating beyond 7 lock radii the intrusion runs out of fluid. Thereafter, the wave continues to spread radially at a constant speed, however, the amplitude decreases sufficiently so that linear dispersion dominates and the amplitude decays with distance as r-1.

  10. Radiation therapy for the solitary plasmacytoma

    Directory of Open Access Journals (Sweden)

    Esengül Koçak

    2010-06-01

    Full Text Available Plasma-cell neoplasms are classically categorized into four groups as: multiple myeloma (MM, plasma-cell leukemias, solitary plasmacytomas (SP of the bone (SPB, and extramedullary plasmacytomas (EMP. These tumors may be described as localized or diffuse in presentation. Localized plasma-cell neoplasms are rare, and include SP of the skeletal system, accounting for 2-5% of all plasma-cell neoplasms, and EMP of soft tissue, accounting for approximately 3% of all such neoplasms. SP is defined as a solitary mass of neoplastic plasma cells either in the bone marrow or in various soft tissue sites. There appears to be a continuum in which SP often progresses to MM. The main treatment modality for SP is radiation therapy (RT. However, there are no conclusive data in the literature on the optimal RT dose for SP. This review describes the interrelationship of plasma-cell neoplasms, and attempts to determine the minimal RT dose required to obtain local control.

  11. Long solitary internal waves in stable stratifications

    Directory of Open Access Journals (Sweden)

    W. B. Zimmerman

    2004-01-01

    Full Text Available Observations of internal solitary waves over an antarctic ice shelf (Rees and Rottman, 1994 demonstrate that even large amplitude disturbances have wavelengths that are bounded by simple heuristic arguments following from the Scorer parameter based on linear theory for wave trapping. Classical weak nonlinear theories that have been applied to stable stratifications all begin with perturbations of simple long waves, with corrections for weak nonlinearity and dispersion resulting in nonlinear wave equations (Korteweg-deVries (KdV or Benjamin-Davis-Ono that admit localized propagating solutions. It is shown that these theories are apparently inappropriate when the Scorer parameter, which gives the lowest wavenumber that does not radiate vertically, is positive. In this paper, a new nonlinear evolution equation is derived for an arbitrary wave packet thus including one bounded below by the Scorer parameter. The new theory shows that solitary internal waves excited in high Richardson number waveguides are predicted to have a halfwidth inversely proportional to the Scorer parameter, in agreement with atmospheric observations. A localized analytic solution for the new wave equation is demonstrated, and its soliton-like properties are demonstrated by numerical simulation.

  12. The solitary sellar plasmacytoma: a diagnostic challenge

    Directory of Open Access Journals (Sweden)

    Anne Soejbjerg

    2016-06-01

    Full Text Available Solitary sellar plasmacytomas are exceedingly rare and difficult to distinguish from other pituitary tumors. We report a case of a 62-year-old woman presenting with blurred vision of the right eye and tenderness of the right temporal region, which was interpreted as temporal arteritis. MRI revealed a pituitary mass lesion (20mm×14mm×17mm without compression of the optic chiasm and her pituitary function was normal. Pituitary surgery was undertaken due to growth of the lesion, and histopathological examination showed a highly cellular neoplasm composed of mature monoclonal plasma cells. Subsequent examinations revealed no evidence of extrasellar myeloma. The patient received pituitary irradiation and has remained well and free of symptoms apart from iatrogenic central diabetes insipidus. Until now, only eight cases of solitary sellar plasmacytoma have been reported. Most frequent symptoms stem from compression of the cranial nerves in the cavernous sinus (III, IV, V, whereas the anterior pituitary function is mostly intact.

  13. Solitary fibrous tumor surrounding the carotid sheath.

    Science.gov (United States)

    Gómez-Oliveira, Guillermo; Alvarez-Flores, Modesto; Arribas-García, Ignacio; Martínez-Gimeno, Carlos

    2010-03-01

    Solitary fibrous tumors (SFTs) are rare spindle cell neoplasms that are mostly found arising from the pleura. Although SFTs recently have been reported in other regions, they are rare in the head and neck and have often been misdiagnosed due to their rarity. SFTs are benign in most cases. Clinically, SFTs usually manifest as well-circumscribed, slow-growing, smooth and painless masses. Symptoms are often minimal, although they may include sore throat, difficulty in swallowing, change of voice or trismus. CT-Scan and MRI are the most sensitive imaging procedures used. The treatment of choice is complete surgical excision of the lesion. Because recurrences have been noted up to 30 years after surgery, long-term follow up is mandatory. In this article, we present a case of a Solitary Fibrous Tumor arising in the parapharyngeal space in a 20-year-old man, involving the carotid sheath, treated by surgical excision with no recurrence after 1 year. The clinical presentation, surgical management and pathological findings are described.

  14. Unsaturated Mn complex decorated hybrid thioarsenates: Syntheses, crystal structures and physical properties

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Cheng-Yang [Key Laboratory of Inorganic Chemistry in Universities of Shandong, Department of Chemistry and Chemical Engineering, Jining University, Qufu, Shandong 273155 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Lei, Xiao-Wu, E-mail: xwlei_jnu@163.com [Key Laboratory of Inorganic Chemistry in Universities of Shandong, Department of Chemistry and Chemical Engineering, Jining University, Qufu, Shandong 273155 (China); Tian, Ya-Wei; Xu, Jing; Bai, Yi-Qun; Wang, Fei; Zhou, Peng-Fei; Liu, Xiao-Fan [Key Laboratory of Inorganic Chemistry in Universities of Shandong, Department of Chemistry and Chemical Engineering, Jining University, Qufu, Shandong 273155 (China); Yi, Fei-Yan, E-mail: yifeiyan@nbu.edu.cn [Faculty of Materials Science & Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211 (China)

    2016-03-15

    The incorporation of unsaturated [Mn(1,2-dap)]{sup 2+}, [Mn(1,2-dap){sub 2}]{sup 2+}, [Mn(2,2-bipy)]{sup 2+} (1,2-dap=1,2-diaminopropane) complex cations with thioarsenate anions of [As{sup III}S{sub 3}]{sup 3−} and [As{sup V}S{sub 4}]{sup 3−} led to three new hybrid manganese thioarsenates, namely, [Mn(1,2-dap)]{sub 2}MnAs{sub 2}S{sub 6} (1), [Mn(1,2-dap){sub 2}]{[Mn(1,2-dap)]_2As_2S_8} (2) and (NH{sub 4})[Mn(2,2-bipy){sub 2}]AsS{sub 4} (3). In compound 1, the unsaturated [Mn(1,2-dap)]{sup 2+} complexes, [MnS{sub 4}]{sup 6−} tetrahedra and [As{sup III}S{sub 3}]{sup 3−} trigonal-pyramids are condensed to form the 1D [Mn(1,2-dap)]{sub 2}MnAs{sub 2}S{sub 6} chain, whereas compound 2 features 2D layer composed of [Mn(1,2-dap)]{sup 2+} and [Mn(1,2-dap){sub 2}]{sup 2+} complexes as well as [As{sup V}S{sub 4}]{sup 3−} tetrahedral units. For compound 3, two [As{sup V}S{sub 4}]{sup 3−} anions bridge two [Mn(2,2-bipy)]{sup 2+} complex cations into a butterfly like {[Mn(2,2-bipy)]_2As_2S_8}{sup 2−} anionic unit. Magnetic measurements indicate the ferrimagnetic behavior for compound 1 and antiferromagnetic (AF) behaviors for compounds 2–3. The UV–vis diffuse-reflectance measurements and electronic structural calculations based on density functional theory (DFT) revealed the title compounds belong to semiconductors with band gaps of 2.63, 2.21, and 1.97 eV, respectively. The narrow band-gap of compound 3 led to the efficient and stable photocatalytic degradation activity over organic pollutant than N-doped P25 under visible light irradiation. - Highlights: Three new hybrid manganese thioarsenates have been prepared and structurally characterized. These hybrid phases feature interesting magnetic and visible light responding photocatalytic properties.

  15. Contribution of interlayer hybridization to the electronic structure in iron pnictides: a study of EELS and first-principles calculations.

    Science.gov (United States)

    Ma, Chao; Yang, Huaixin; Tian, Huanfang; Shi, Honglong; Wang, Zhiwei; Li, Jianqi

    2013-03-20

    Using electron energy loss spectroscopy (EELS) measurements and first-principles electronic structure calculations, the significant interlayer hybridization between the insulating layers (ReO or Ba) and the conducting FeAs layers was investigated in the layered iron pnictides, which is quite different from the case in the cuprate superconductors. This interlayer hybridization would result in an increase in the bandwidth near the Fermi level and interorbital charge transfer in the Fe 3d orbitals, which subsequently leads to a decrease in the Fe local moment and the modification of the Fermi surface topology. Therefore, a three-dimensional character of the electronic structure due to the interlayer hybridization is expected, as observed in previous experiments. These findings indicate that reduced dimensionality is no longer a necessary condition in the search for high-T(c) superconductors in iron pnictides.

  16. Mechanical properties and production quality of hand-layup and vacuum infusion processed hybrid composite materials for GFRP marine structures

    Directory of Open Access Journals (Sweden)

    Sang-Young Kim

    2014-09-01

    Full Text Available Glass Fiber Reinforced Plastic (GFRP structures are primarily manufactured using hand lay-up or vacuum infusion techniques, which are cost-effective for the construction of marine vessels. This paper aims to investigate the mechanical properties and failure mechanisms of the hybrid GFRP composites, formed by applying the hand lay-up processed exterior and the vacuum infusion processed interior layups, providing benefits for structural performance and ease of manufacturing. The hybrid GFRP composites contain one, two, and three vacuum infusion processed layer sets with consistent sets of hand lay-up processed layers. Mechanical properties assessed in this study include tensile, compressive and in-plane shear properties. Hybrid composites with three sets of vacuum infusion layers showed the highest tensile mechanical properties while those with two sets had the highest mechanical properties in compression. The batch homogeneity, for the GFRP fabrication processes, is evaluated using the experimentally obtained mechanical properties.

  17. PIC simulation of compressive and rarefactive dust ion-acoustic solitary waves

    Science.gov (United States)

    Li, Zhong-Zheng; Zhang, Heng; Hong, Xue-Ren; Gao, Dong-Ning; Zhang, Jie; Duan, Wen-Shan; Yang, Lei

    2016-08-01

    The nonlinear propagations of dust ion-acoustic solitary waves in a collisionless four-component unmagnetized dusty plasma system containing nonextensive electrons, inertial negative ions, Maxwellian positive ions, and negatively charged static dust grains have been investigated by the particle-in-cell method. By comparing the simulation results with those obtained from the traditional reductive perturbation method, it is observed that the rarefactive KdV solitons propagate stably at a low amplitude, and when the amplitude is increased, the prime wave form evolves and then gradually breaks into several small amplitude solitary waves near the tail of soliton structure. The compressive KdV solitons propagate unstably and oscillation arises near the tail of soliton structure. The finite amplitude rarefactive and compressive Gardner solitons seem to propagate stably.

  18. A Hybrid Approach to Structure and Function Modeling of G Protein-Coupled Receptors.

    Science.gov (United States)

    Latek, Dorota; Bajda, Marek; Filipek, Sławomir

    2016-04-25

    The recent GPCR Dock 2013 assessment of serotonin receptor 5-HT1B and 5-HT2B, and smoothened receptor SMO targets, exposed the strengths and weaknesses of the currently used computational approaches. The test cases of 5-HT1B and 5-HT2B demonstrated that both the receptor structure and the ligand binding mode can be predicted with the atomic-detail accuracy, as long as the target-template sequence similarity is relatively high. On the other hand, the observation of a low target-template sequence similarity, e.g., between SMO from the frizzled GPCR family and members of the rhodopsin family, hampers the GPCR structure prediction and ligand docking. Indeed, in GPCR Dock 2013, accurate prediction of the SMO target was still beyond the capabilities of most research groups. Another bottleneck in the current GPCR research, as demonstrated by the 5-HT2B target, is the reliable prediction of global conformational changes induced by activation of GPCRs. In this work, we report details of our protocol used during GPCR Dock 2013. Our structure prediction and ligand docking protocol was especially successful in the case of 5-HT1B and 5-HT2B-ergotamine complexes for which we provide one of the most accurate predictions. In addition to a description of the GPCR Dock 2013 results, we propose a novel hybrid computational methodology to improve GPCR structure and function prediction. This computational methodology employs two separate rankings for filtering GPCR models. The first ranking is ligand-based while the second is based on the scoring scheme of the recently published BCL method. In this work, we prove that the use of knowledge-based potentials implemented in BCL is an efficient way to cope with major bottlenecks in the GPCR structure prediction. Thereby, we also demonstrate that the knowledge-based potentials for membrane proteins were significantly improved, because of the recent surge in available experimental structures.

  19. Prediction of protein secondary structure using probability based features and a hybrid system.

    Science.gov (United States)

    Ghanty, Pradip; Pal, Nikhil R; Mudi, Rajani K

    2013-10-01

    In this paper, we propose some co-occurrence probability-based features for prediction of protein secondary structure. The features are extracted using occurrence/nonoccurrence of secondary structures in the protein sequences. We explore two types of features: position-specific (based on position of amino acid on fragments of protein sequences) as well as position-independent (independent of amino acid position on fragments of protein sequences). We use a hybrid system, NEUROSVM, consisting of neural networks and support vector machines for classification of secondary structures. We propose two schemes NSVMps and NSVM for protein secondary structure prediction. The NSVMps uses position-specific probability-based features and NEUROSVM classifier whereas NSVM uses the same classifier with position-independent probability-based features. The proposed method falls in the single-sequence category of methods because it does not use any sequence profile information such as position specific scoring matrices (PSSM) derived from PSI-BLAST. Two widely used datasets RS126 and CB513 are used in the experiments. The results obtained using the proposed features and NEUROSVM classifier are better than most of the existing single-sequence prediction methods. Most importantly, the results using NSVMps that are obtained using lower dimensional features, are comparable to those by other existing methods. The NSVMps and NSVM are finally tested on target proteins of the critical assessment of protein structure prediction experiment-9 (CASP9). A larger dataset is used to compare the performance of the proposed methods with that of two recent single-sequence prediction methods. We also investigate the impact of presence of different amino acid residues (in protein sequences) that are responsible for the formation of different secondary structures.

  20. Hybrid Structure of a Dynamic Single-Chain Carboxylase from Deinococcus radiodurans.

    Science.gov (United States)

    Hagmann, Anna; Hunkeler, Moritz; Stuttfeld, Edward; Maier, Timm

    2016-08-01

    Biotin-dependent acyl-coenzyme A (CoA) carboxylases (aCCs) are involved in key steps of anabolic pathways and comprise three distinct functional units: biotin carboxylase (BC), biotin carboxyl carrier protein (BCCP), and carboxyl transferase (CT). YCC multienzymes are a poorly characterized family of prokaryotic aCCs of unidentified substrate specificity, which integrate all functional units into a single polypeptide chain. We employed a hybrid approach to study the dynamic structure of Deinococcus radiodurans (Dra) YCC: crystal structures of isolated domains reveal a hexameric CT core with extended substrate binding pocket and a dimeric BC domain. Negative-stain electron microscopy provides an approximation of the variable positioning of the BC dimers relative to the CT core. Small-angle X-ray scattering yields quantitative information on the ensemble of Dra YCC structures in solution. Comparison with other carrier protein-dependent multienzymes highlights a characteristic range of large-scale interdomain flexibility in this important class of biosynthetic enzymes.

  1. Energy-Efficient Large-Scale Antenna Systems with Hybrid Digital-Analog Beamforming Structure

    Institute of Scientific and Technical Information of China (English)

    Shuangfeng Han; ChihLin I; Zhikun Xu; Qi Sun; Haibin Li

    2015-01-01

    A large⁃scale antenna system (LSAS) with digital beamforming is expected to significantly increase energy efficiency (EE) and spectral efficiency (SE) in a wireless communication system. However, there are many challenging issues related to calibration, en⁃ergy consumption, and cost in implementing a digital beamforming structure in an LSAS. In a practical LSAS deployment, hybrid digital⁃analog beamforming structures with active antennas can be used. In this paper, we investigate the optimal antenna configu⁃ration in an N × M beamforming structure, where N is the number of transceivers, M is the number of active antennas per trans⁃ceiver, where analog beamforming is introduced for individual transceivers and digital beamforming is introduced across all N transceivers. We analyze the green point, which is the point of maximum EE on the EE⁃SE curve, and show that the log⁃scale EE scales linearly with SE along a slope of ⁃lg2/N. We investigate the effect of M on EE for a given SE value in the case of fixed NM and independent N and M. In both cases, there is a unique optimal M that results in optimal EE. In the case of independent N and M, there is no optimal (N, M) combination for optimizing EE. The results of numerical simulations are provided, and these re⁃sults support our analysis.

  2. Numerical Study on Nonlinear Semiactive Control of Steel-Concrete Hybrid Structures Using MR Dampers

    Directory of Open Access Journals (Sweden)

    Long-He Xu

    2013-01-01

    Full Text Available Controlling the damage process, avoiding the global collapse, and increasing the seismic safety of the super high-rise building structures are of great significance to the casualties’ reduction and seismic losses mitigation. In this paper, a semiactive control platform based on magnetorheological (MR dampers comprising the Bouc-Wen model, the semi-active control law, and the shear wall damage criteria and steel damage material model is developed in LS-DYNA program, based on the data transferring between the main program and the control platform; it can realize the purpose of integrated modeling, analysis, and design of the nonlinear semi-active control system. The nonlinear seismic control effectiveness is verified by the numerical example of a 15-story steel-concrete hybrid structure; the results indicate that the control platform and the numerical method are stable and fast, the relative displacement, shear force, and damage of the steel-concrete structure are largely reduced using the optimal designed MR dampers, and the deformations and shear forces of the concrete tube and frame are better consorted by the control devices.

  3. Structures, Phase Transitions and Tricritical Behavior of the Hybrid Perovskite Methyl Ammonium Lead Iodide

    Science.gov (United States)

    Whitfield, P. S.; Herron, N.; Guise, W. E.; Page, K.; Cheng, Y. Q.; Milas, I.; Crawford, M. K.

    2016-01-01

    We have examined the crystal structures and structural phase transitions of the deuterated, partially deuterated and hydrogenous organic-inorganic hybrid perovskite methyl ammonium lead iodide (MAPbI3) using time-of-flight neutron and synchrotron X-ray powder diffraction. Near 330 K the high temperature cubic phases transformed to a body-centered tetragonal phase. The variation of the order parameter Q for this transition scaled with temperature T as Q ∼ (Tc−T)β, where Tc is the critical temperature and the exponent β was close to ¼, as predicted for a tricritical phase transition. However, we also observed coexistence of the cubic and tetragonal phases over a range of temperature in all cases, demonstrating that the phase transition was in fact first-order, although still very close to tricritical. Upon cooling further, all the tetragonal phases transformed into a low temperature orthorhombic phase around 160 K, again via a first-order phase transition. Based upon these results, we discuss the impact of the structural phase transitions upon photovoltaic performance of MAPbI3 based solar cells. PMID:27767049

  4. Structure-property relationships in hybrid dental nanocomposite resins containing monofunctional and multifunctional polyhedral oligomeric silsesquioxanes.

    Science.gov (United States)

    Wang, Weiguo; Sun, Xiang; Huang, Li; Gao, Yu; Ban, Jinghao; Shen, Lijuan; Chen, Jihua

    2014-01-01

    Organic-inorganic hybrid materials, such as polyhedral oligomeric silsesquioxanes (POSS), have the potential to improve the mechanical properties of the methacrylate-based composites and resins used in dentistry. In this article, nanocomposites of methacryl isobutyl POSS (MI-POSS [bears only one methacrylate functional group]) and methacryl POSS (MA-POSS [bears eight methacrylate functional groups]) were investigated to determine the effect of structures on the properties of dental resin. The structures of the POSS-containing networks were determined by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. Monofunctional POSS showed a strong tendency toward aggregation and crystallization, while multifunctional POSS showed higher miscibility with the dimethacrylate monomer. The mechanical properties and wear resistance decreased with increasing amounts of MI-POSS, indicating that the MI-POSS agglomerates act as the mechanical weak point in the dental resins. The addition of small amounts of MA-POSS improved the mechanical and shrinkage properties. However, samples with a higher MA-POSS concentration showed lower flexural strength and flexural modulus, indicating that there is a limited range in which the reinforcement properties of MA-POSS can operate. This concentration dependence is attributed to phase separation at higher concentrations of POSS, which affects the structural integrity, and thus, the mechanical and shrinkage properties of the dental resin. Our results show that resin with 3% MA-POSS is a potential candidate for resin-based dental materials.

  5. Reversible Structural Swell-Shrink and Recoverable Optical Properties in Hybrid Inorganic-Organic Perovskite.

    Science.gov (United States)

    Zhang, Yupeng; Wang, Yusheng; Xu, Zai-Quan; Liu, Jingying; Song, Jingchao; Xue, Yunzhou; Wang, Ziyu; Zheng, Jialu; Jiang, Liangcong; Zheng, Changxi; Huang, Fuzhi; Sun, Baoquan; Cheng, Yi-Bing; Bao, Qiaoliang

    2016-07-26

    Ion migration in hybrid organic-inorganic perovskites has been suggested to be an important factor for many unusual behaviors in perovskite-based optoelectronics, such as current-voltage hysteresis, low-frequency giant dielectric response, and the switchable photovoltaic effect. However, the role played by ion migration in the photoelectric conversion process of perovskites is still unclear. In this work, we provide microscale insights into the influence of ion migration on the microstructure, stability, and light-matter interaction in perovskite micro/nanowires by using spatially resolved optical characterization techniques. We observed that ion migration, especially the migration of MA(+) ions, will induce a reversible structural swell-shrink in perovskites and recoverably affect the reflective index, quantum efficiency, light-harvesting, and photoelectric properties. The maximum ion migration quantity in perovskites was as high as approximately 30%, resulting in lattice swell or shrink of approximately 4.4%. Meanwhile, the evidence shows that ion migration in perovskites could gradually accelerate the aging of perovskites because of lattice distortion in the reversible structural swell-shrink process. Knowledge regarding reversible structural swell-shrink and recoverable optical properties may shed light on the development of optoelectronic and converse piezoelectric devices based on perovskites.

  6. Structures, Phase Transitions and Tricritical Behavior of the Hybrid Perovskite Methyl Ammonium Lead Iodide

    Science.gov (United States)

    Whitfield, P. S.; Herron, N.; Guise, W. E.; Page, K.; Cheng, Y. Q.; Milas, I.; Crawford, M. K.

    2016-10-01

    We have examined the crystal structures and structural phase transitions of the deuterated, partially deuterated and hydrogenous organic-inorganic hybrid perovskite methyl ammonium lead iodide (MAPbI3) using time-of-flight neutron and synchrotron X-ray powder diffraction. Near 330 K the high temperature cubic phases transformed to a body-centered tetragonal phase. The variation of the order parameter Q for this transition scaled with temperature T as Q ˜ (Tc-T)β, where Tc is the critical temperature and the exponent β was close to ¼, as predicted for a tricritical phase transition. However, we also observed coexistence of the cubic and tetragonal phases over a range of temperature in all cases, demonstrating that the phase transition was in fact first-order, although still very close to tricritical. Upon cooling further, all the tetragonal phases transformed into a low temperature orthorhombic phase around 160 K, again via a first-order phase transition. Based upon these results, we discuss the impact of the structural phase transitions upon photovoltaic performance of MAPbI3 based solar cells.

  7. Reduced graphene oxide/ZnO hybrid structure for high-performance photodetection

    Energy Technology Data Exchange (ETDEWEB)

    Darbari, S.; Ahmadi, V., E-mail: v_ahmadi@modares.ac.ir [Tarbiat Modares University, Department of Electrical and Computer Engineering (Iran, Islamic Republic of); Afzali, P.; Abdi, Y. [University of Tehran, Department of Physics (Iran, Islamic Republic of); Feda, M. [Tarbiat Modares University, Department of Electrical and Computer Engineering (Iran, Islamic Republic of)

    2014-12-15

    We report the optoelectronic behavior of a novel reduced graphene oxide (rGO)/ZnO structure which has been realized by photocatalytic reduction of chemically exfoliated GO sheets. Lateral ZnO nanowires, which are grown between interdigital electrodes by a novel plasma-assisted procedure, are utilized as the photocatalyst metal oxide in the presented heterostructure. Raman spectroscopy and FTIR analyses are utilized to show that photocatalytic reduction of GO sheets, with few (less than 5) layers, occurs after about 30 min of UV-illumination. Low-temperature electrical characterizations are applied to demonstrate one-dimensional behavior of the realized rGO ribbons, with an estimated width of around 30 nm. The optoelectronic characteristics of the fabricated rGO/ZnO hybrid structure also lead to high responsivity of about 12 A/W and a sensitivity of about 5 × 10{sup 4−} % (at the bias voltage of −5 V), which entitles the fabricated structure as an efficient photodetector. All in all, our experimental results open up a promising simple approach to fabricate GNR-based devices by assisting lateral ZnO nanowire, without involving nanolithography issues.

  8. Hybrid state vector methods for structural dynamic and aeroelastic boundary value problems

    Science.gov (United States)

    Lehman, L. L.

    1982-01-01

    A computational technique is developed that is suitable for performing preliminary design aeroelastic and structural dynamic analyses of large aspect ratio lifting surfaces. The method proves to be quite general and can be adapted to solving various two point boundary value problems. The solution method, which is applicable to both fixed and rotating wing configurations, is based upon a formulation of the structural equilibrium equations in terms of a hybrid state vector containing generalized force and displacement variables. A mixed variational formulation is presented that conveniently yields a useful form for these state vector differential equations. Solutions to these equations are obtained by employing an integrating matrix method. The application of an integrating matrix provides a discretization of the differential equations that only requires solutions of standard linear matrix systems. It is demonstrated that matrix partitioning can be used to reduce the order of the required solutions. Results are presented for several example problems in structural dynamics and aeroelasticity to verify the technique and to demonstrate its use. These problems examine various types of loading and boundary conditions and include aeroelastic analyses of lifting surfaces constructed from anisotropic composite materials.

  9. Effects of Charge in Heavy Ions on Solitary Kinetic Alfvén Waves in Double-Ion Plasmas

    Institute of Scientific and Technical Information of China (English)

    YANG Lei; WU De-Jin

    2006-01-01

    @@ After the charge of heavy ions is considered, a Sagdeev equation is obtained for the solitary kinetic Alfvén waves (SKAWs) in a low-β(me/mp<<β<<1 or mp/me>>α>>1), three-component (electrons, protons, and highly charged heavy ions) plasma. Numerical results show that the charge number q of heavy ions can cause the width of the solitary structure to decrease, but increase for the maximum of electron density nem≤1.2 and the initial abundance of heavy ions Cb0 ≤ 0.1. The parallel phase speed of the waves increases with larger q.

  10. Effects of trapped electrons on the oblique propagation of ion acoustic solitary waves in electron-positron-ion plasmas

    Science.gov (United States)

    Hafez, M. G.; Roy, N. C.; Talukder, M. R.; Hossain Ali, M.

    2016-08-01

    The characteristics of the nonlinear oblique propagation of ion acoustic solitary waves in unmagnetized plasmas consisting of Boltzmann positrons, trapped electrons and ions are investigated. The modified Kadomtsev-Petviashivili ( m K P ) equation is derived employing the reductive perturbation technique. The parametric effects on phase velocity, Sagdeev potential, amplitude and width of solitons, and electrostatic ion acoustic solitary structures are graphically presented with the relevant physical explanations. This study may be useful for the better understanding of physical phenomena concerned in plasmas in which the effects of trapped electrons control the dynamics of wave.

  11. A unique semiconductor-carbon-metal hybrid structure design as a counter electrode in dye-sensitized solar cells.

    Science.gov (United States)

    Guo, Sheng-Qi; Wang, Ling-Chang; Zhang, Chen-Guang; Qi, Gao-Can; Gu, Bing-Chuan; Liu, Lu; Yuan, Zhi-Hao

    2017-05-25

    The catalytic activity of counter electrodes (CEs) severely restricts the photovoltaic conversion efficiency of dye-sensitized solar cells. However, electrons trapped by bulk defects greatly reduce the catalytic activity of the CE. In this study, we report a novel In2S3-C-Au hybrid structure designed by simply decorating Au particles on the surface of carbon-coated hierarchical In2S3 flower-like architectures, which could avoid the abovementioned problems. This effect can be attributed to the unique contribution of indium sulfide, carbon, and Au from the hybrid structure, as well as to their synergy. Electrochemical measurements revealed that the hybrid structure possessed high catalytic activity and electrochemical stability for the interconversion of the redox couple I3(-)/I(-). Moreover, this superior performance can be incorporated into the dye-sensitized solar cells system. We used this hybrid structure as a counter electrode by casting it on an FTO substrate to form a film, which displayed better photovoltaic conversion efficiency (8.91%) than the commercial Pt counterpart (7.67%).

  12. Synthesis of palladium nanoparticle modified reduced graphene oxide and multi-walled carbon nanotube hybrid structures for electrochemical applications

    Science.gov (United States)

    Hu, Jie; Zhao, Zhenting; Zhang, Jun; Li, Gang; Li, Pengwei; Zhang, Wendong; Lian, Kun

    2017-02-01

    In this work, palladium (Pd) nanoparticles functionalized reduced graphene oxide (rGO) and multi-walled carbon nanotubes (MWCNTs) hybrid structures (Pd/rGO-MWCNTs) were successfully prepared by a combination of electrochemical reduction with electrodeposition method. The morphology, structure, and composition of the Pd/rGO-MWCNTs hybrid were characterized by scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy. The as-synthesized hybrid structures were modified on the glassy carbon electrode (GCE) and further utilized for hydrazine sensing. Electrochemical impedance spectroscopic, cyclic voltammetry and single-potential amperometry experiments were carried out on Pd/rGO-MWCNTs hybrid structures to investigate the interface properties and sensing performance. The measured results demonstrate that the fabricated Pd/rGO-MWCNTs/GCE sensor show a high sensitivity of 7.09 μA μM-1 cm-2 in a large concentration range of 1.0 to 1100 μM and a low detection limit of 0.15 μM. Moreover, the as-prepared sensor exhibits good selectivity and stability for the determination of hydrazine under interference conditions.

  13. Hybrid Control of Supply Chains: a Structured Exploration from a Systems Perspective

    Directory of Open Access Journals (Sweden)

    Paul W. P. J. Grefen

    2013-07-01

    Full Text Available Supply chains are becoming increasingly complex these days, both in the structure of the chains and in the need for fine-grained, real-time control. This development occurs in many industries, such as manufacturing, logistics, and the service industry. The increasing structural complexity is caused by larger numbers of participating companies in supply chains because of increasing complexity of products and services. Increasing requirements to control are caused by developments like mass-customization, pressure on delivery times, and smaller margins for waste. Maintaining well-structured strategic, tactic, and operational control over these complex supply chains is not an easy task – certainly as they are pressured by end-to-end synchronization requirements and just-in-time demands. Things become even more complex when chains need to be flexible to react to changing requirements to the products or services they deliver. To enable design of well-structured control, clear models of control topologies are required. In this paper, we address this need by exploring supply chain control topologies in an organized fashion. The exploration is based on integrating a supply chain model and a control model in two alternative ways to obtain two extreme models for supply chain control. These two models are next combined to obtain a hybrid chain control model in which control parameters can be adapted to accommodate different circumstances, hence facilitating agility in supply chains and networks. We apply the developed model to a number of case studies to show its usability. The contribution of this paper is the structured analysis of the design space for chain-level control models - not the description of individual new models.

  14. Crash simulation of hybrid structures considering the stress and strain rate dependent material behavior of thermoplastic materials

    Science.gov (United States)

    Hopmann, Ch.; Schöngart, M.; Weber, M.; Klein, J.

    2015-05-01

    Thermoplastic materials are more and more used as a light weight replacement for metal, especially in the automotive industry. Since these materials do not provide the mechanical properties, which are required to manufacture supporting elements like an auto body or a cross bearer, plastics are combined with metals in so called hybrid structures. Normally, the plastics components are joined to the metal structures using different technologies like welding or screwing. Very often, the hybrid structures are made of flat metal parts, which are stiffened by a reinforcement structure made of thermoplastic materials. The loads on these structures are very often impulsive, for example in the crash situation of an automobile. Due to the large stiffness variation of metal and thermoplastic materials, complex states of stress and very high local strain rates occur in the contact zone under impact conditions. Since the mechanical behavior of thermoplastic materials is highly dependent on these types of load, the crash failure of metal plastic hybrid parts is very complex. The problem is that the normally used strain rate dependent elastic/plastic material models are not capable to simulate the mechanical behavior of thermoplastic materials depended on the state of stress. As part of a research project, a method to simulate the mechanical behavior of hybrid structures under impact conditions is developed at the IKV. For this purpose, a specimen for the measurement of mechanical properties dependet on the state of stress and a method for the strain rate depended characterization of thermoplastic materials were developed. In the second step impact testing is performed. A hybrid structure made from a metal sheet and a reinforcement structure of a Polybutylenterephthalat Polycarbonate blend is tested under impact conditions. The measured stress and strain rate depended material data are used to simulate the mechanical behavior of the hybrid structure under highly dynamic load with

  15. Positron annihilation lifetime spectroscopy study on the structural relaxation of phenylmethylsiloxane-modified epoxy hybrids at different aging temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Chia-Wen [Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan (China); Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan (China); Ma, Chen-Chi M., E-mail: ccma@che.nthu.edu.tw [Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan (China); Tan, Chung-Sung [Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan (China); Li, Hsun-Tien [Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan (China)

    2015-07-15

    The cured network conformations and structural relaxation behaviours of the diglycidyl ether of bisphenol A (DGEBA)-methylhexahydrophthalic anhydride (MHHPA) modified with phenylmethylsiloxane-modified epoxy (PMSE) at different aging temperatures were studied using dynamic mechanical analysis (DMA) and positron annihilation lifetime spectroscopy (PALS). The DMA results revealed that the cured PMSE network can insert into the cured DGEBA network to form interpenetrating polymer networks (IPNs). The structural relaxation behaviours of DGEBA–PMSE-0.4 produced using DGEBA, PMSE, and MHHPA at a ratio of 0.6:0.4:1 by equivalent weight were studied using PALS at 150 °C and 55 °C. The aging-induced free volume relaxation parameters of DGEBA–PMSE-0.4 at 150 °C and 55 °C were investigated using the double additive exponential model and the Kohlrausch–Williams–Watts exponential model. For double additive exponential model, only one relaxation time (ζ) of 584.5 h was found at 150 °C; By contrast, there were two separate relaxation times of 37.4 h (ζ{sub 1}) and 753.6 h (ζ{sub 2}) at 55 °C. The ζ{sub 1} of the IPNs hybrid can be attributed to the network relaxation of PMSE, and the ζ{sub 2} can be attributed to the network relaxation of DGEBA at 55 °C. The results suggested the double additive exponential model can effectively predict DGEBA–PMSE hybrid relaxation behaviours. - Highlights: • The cured network conformations of DGEBA–PMSE hybrids were studied using DMA. • The structural relaxation behaviours of DGEBA–PMSE hybrids were studied using PALS. • The cured DGEBA–PMSE hybrids were interpenetrating polymer networks (IPNs). • PALS studies provided a quantitative demonstration of relaxation behaviours. • Double additive exponential model effectively predicted the relaxation times of hybrids.

  16. Hybrid carbon fiber/carbon nanotube composites for structural damping applications.

    Science.gov (United States)

    Tehrani, M; Safdari, M; Boroujeni, A Y; Razavi, Z; Case, S W; Dahmen, K; Garmestani, H; Al-Haik, M S

    2013-04-19

    Carbon nanotubes (CNTs) were grown on the surface of carbon fibers utilizing a relatively low temperature synthesis technique; graphitic structures by design (GSD). To probe the effects of the synthesis protocols on the mechanical properties, other samples with surface grown CNTs were prepared using catalytic chemical vapor deposition (CCVD). The woven graphite fabrics were thermally shielded with a thin film of SiO2 and CNTs were grown on top of this film. Raman spectroscopy and electron microscopy revealed the grown species to be multi-walled carbon nanotubes (MWCNTs). The damping performance of the hybrid CNT-carbon fiber-reinforced epoxy composite was examined using dynamic mechanical analysis (DMA). Mechanical testing confirmed that the degradations in the strength and stiffness as a result of the GSD process are far less than those encountered through using the CCVD technique and yet are negligible compared to the reference samples. The DMA results indicated that, despite the minimal degradation in the storage modulus, the loss tangent (damping) for the hybrid composites utilizing GSD-grown MWCNTs improved by 56% compared to the reference samples (based on raw carbon fibers with no surface treatment or surface grown carbon nanotubes) over the frequency range 1-60 Hz. These results indicated that the energy dissipation in the GSD-grown MWCNTs composite can be primarily attributed to the frictional sliding at the nanotube/epoxy interface and to a lesser extent to the stiff thermal shielding SiO2 film on the fiber/matrix interface.

  17. Proximity-induced low-energy renormalization in hybrid semiconductor-superconductor Majorana structures

    Science.gov (United States)

    Stanescu, Tudor D.; Das Sarma, Sankar

    2017-07-01

    A minimal model for the hybrid superconductor-semiconductor nanowire Majorana platform is developed that fully captures the effects of the low-energy renormalization of the nanowire modes arising from the presence of the parent superconductor. In this model, the parent superconductor is an active component that participates explicitly in the low-energy physics, not just a passive partner that only provides proximity-induced Cooper pairs for the nanowire. This treatment on an equal footing of the superconductor and the semiconductor has become necessary in view of recent experiments, which do not allow a consistent interpretation based just on the bare semiconductor properties. The general theory involves the evaluation of the exact semiconductor Green's function that includes a dynamical self-energy correction arising from the tunnel-coupled superconductor. Using a tight-binding description, the nanowire Green's function is obtained in various relevant parameter regimes, with the parent superconductor being treated within the BCS-BdG prescription. General conditions for the emergence of topological superconductivity are worked out for single-band as well as multiband nanowires and detailed numerical results are given for both infinite and finite wire cases. The topological quantum phase diagrams are provided numerically and the Majorana bound states are obtained along with their oscillatory energy-splitting behaviors due to wave function overlap in finite wires. Renormalization effects are shown to be both qualitatively and quantitatively important in modifying the low-energy spectrum of the nanowire. The results of the theory are found to be in good qualitative agreement with Majorana nanowire experiments, leading to the conclusion that the proximity-induced low-energy renormalization of the nanowire modes by the parent superconductor is of fundamental importance in superconductor-semiconductor hybrid structures, except perhaps in the uninteresting limit of

  18. Monte Carlo simulations of biaxial structure in thin hybrid nematic film based upon spatially anisotropic pair potential

    Institute of Scientific and Technical Information of China (English)

    Zhang Zhi-Dong; Chang Chun-Rui; Ma Dong-Lai

    2009-01-01

    Hybrid nematic films have been studied by Monte Carlo simulations using a lattice spin model,in which the pair potential is spatially anisotropic and dependent on elastic constants of liquid crystals.We confirm in the thin hybrid nematic film the existence of a biaxially nonbent structure and the structarc transition from the biaxial to the bent-director structure,which is similar to the result obtained using the Lebwohl-Lasher model.However,the step-like director's profile,characteristic for the biaxial structure,is spatially asymmetric in the film because the pair potential leads to K1≠K3.We estimate the upper cell thickness to be 69 spin layers,in which the biaxial structure can be found.

  19. Three-dimensional structures of graphene/polyaniline hybrid films constructed by steamed water for high-performance supercapacitors

    Science.gov (United States)

    Zhang, Liling; Huang, Da; Hu, Nantao; Yang, Chao; Li, Ming; Wei, Hao; Yang, Zhi; Su, Yanjie; Zhang, Yafei

    2017-02-01

    A novel three-dimensional (3D) structure of reduced graphene oxide/polyaniline (rGO/PANI) hybrid films has been demonstrated for high-performance supercapacitors. Steamed water in closed vessels with high pressure and moderately high temperature is applied to facilely construct this structure. The as-designed rGO/PANI hybrid films exhibit a highest gravimetric specific capacitance of 1182 F g-1 at 1 A g-1 in the three-electrode test. The assembled symmetric device based on this structure shows both a high capacitance of 808 F g-1 at 1 A g-1 and a high gravimetric energy density (28.06 Wh kg-1 at a power density of 0.25 kW kg-1). Above all, this novel 3D structure constructed by steamed water regulation techniques shows excellent capacitance performance and holds a great promise for high-performance energy storage applications.

  20. Prediction of structure response of missile instrument cabin based on Hybrid FE-SEA%应用Hybrid FE-SEA预示仪器舱动力学环境

    Institute of Scientific and Technical Information of China (English)

    刘时秀

    2011-01-01

    应用Hybrid FE-SEA方法,对某导弹仪器舱在宽频混响声场中结构响应进行了分析计算,并将Hybrid FE-SEA方法预示结果与试验结果作了比较,初步验证了Hybrid FE-SEA方法计算复杂结构声振响应的可行性.%The structure response of a missile instrument cabin in the broadband reverberation sound field is analyzed and calculated by the method of Hybrid FE-SEA. The results of the method are compared with the testing results, which primarily validates the feasibility of calculating the acoustic response of complex structure by the method of Hybrid FE-SEA.

  1. Multiwalled carbon nanotubes and dispersed nanodiamond novel hybrids: Microscopic structure evolution, physical properties, and radiation resilience

    Science.gov (United States)

    Gupta, S.; Farmer, J.

    2011-01-01

    We report the structure and physical properties of novel hybrids of multiwalled carbon nanotubes (MWCNTs) and ultradispersed diamond (UDD) forming nanocomposite ensemble that were subjected to 50, 100, and 103 kGy gamma ray doses and characterized using various analytical tools to investigate hierarchical defects evolution. This work is prompted by recent work on single-walled CNTs and UDD ensemble [Gupta et al., J. Appl. Phys. 107, 104308 (2010)] where radiation-induced microscopic defects seem to be stabilized by UDD. The present experiments show similar effects where these hybrids display only a minimal structural modification under the maximum dose. Quantitative analyses of multiwavelength Raman spectra revealed lattice defects induced by irradiation assessed through the variation in prominent D, G, and 2D bands. A minimal change in the position of D, G, and 2D bands and a marginal increase in intensity of the defect-induced double resonant Raman scattered D and 2D bands are some of the implications suggesting the radiation coupling. The in-plane correlation length (La) was also determined following Tunistra-Koenig relation from the ratio of D to G band (ID/IG) besides microscopic stress. However, we also suggest the following taking into account of intrinsic defects of the constituents: (a) charge transfer arising at the interface due to the difference in electronegativity of MWCNT C sp2 and UDD core (C sp3) leading to phonon and electron energy renormalization; (b) misorientation of C sp2 at the interface of MWCNT and UDD shell (C sp2) resulting in structural disorder; (c) softening or violation of the q ˜0 selection rule leading to D band broadening and a minimal change in G band intensity; and (d) normalized intensity of D and G bands with 2D band help to distinguish defect-induced double resonance phenomena. The MWCNT when combined with nanodiamond showed a slight decrease in their conductance further affected by irradiation pointing at relatively good

  2. Organic-inorganic semiconductor hybrid systems. Structure, morphology, and electronic properties

    Energy Technology Data Exchange (ETDEWEB)

    El Helou, Mira

    2012-08-22

    This dissertation addresses the preparation and characterization of hybrid semiconducting systems combining organic with inorganic materials. Characterization methods used included to determine the structure, morphology, and thermal stability comprised X-ray diffraction (XRD), atomic force microscopy (AFM), thermal desorption spectroscopy (TDS), and X-ray photoelectron spectroscopy (XPS). One organic-inorganic semiconducting system was pentacene (C{sub 22}H{sub 14}) and zinc oxide. This interface was investigated in detail for pentacene on an oxygen-terminated zinc oxide surface, i.e. ZnO(000 anti 1). An extended study on the promising p-n junction was carried out for pentacene on ZnO with different orientations which exhibit different chemical and structural characteristics: ZnO(000 anti 1), ZnO(0001), and ZnO(10 anti 10). Moreover, the organic crystal structure of pentacene was selectively tuned by carefully choosing the substrate temperature. This defined interface with a physisorbed pentacene layer on ZnO was characterized by optical absorption which depends on the temperature of the measured system, the pentacene film thickness, and the molecular orientation and packing. The high quality of the pentacene films allowed in one case to characterize the Davydov splitting by linear polarized light focused on a single crystallite. Another subject in the field of organic-inorganic hybrid materials comprised conjugated dithiols used as self-assembled monolayers (SAMs) for immobilizing semiconducting CdS nanoparticles (NPs) on Au substrates. It was demonstrated that an appropriate selection and preparation of the conjugated SAMs is crucial for building up a light-addressable potentiometric sensor with a sufficient efficiency. An optimized electron transfer was achieved with SAMs of long range ordering, high stability, and adequate conductivity. This was examined for different linkers and was best for stilbenedithiol immobilized in solution at higher temperatures. Due

  3. A One-Structure-Based Hybridized Nanogenerator for Scavenging Mechanical and Thermal Energies by Triboelectric-Piezoelectric-Pyroelectric Effects.

    Science.gov (United States)

    Wang, Shuhua; Wang, Zhong Lin; Yang, Ya

    2016-04-20

    A hybridized nanogenerator is demonstrated, which has the structure of PVDF nanowires-PDMS composite film/indium tin oxide (ITO) electrode/polarized PVDF film/ITO electrode, and which can individually/simultaneously scavenge mechanical and thermal energies using piezoelectric, triboelectric, and pyroelectric effects. As compared with the individual energy harvesting unit, the hybridized nanogenerator has a much better charging performance. This work may push forward a significant step toward multienergy harvesting technology. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Functionalized Self-Assembled InAs/GaAs Quantum-Dot Structures Hybridized with Organic Molecules

    DEFF Research Database (Denmark)

    Chen, Miaoxiang Max; Kobashi, K.; Chen, B.

    2010-01-01

    Low-dimensional III-V semiconductors have many advantages over other semiconductors; however, they are not particularly stable under physiological conditions. Hybridizing biocompatible organic molecules with advanced optical and electronic semiconductor devices based on quantum dots (QDs......) and quantum wires could provide an efficient solution to realize stress-free and nontoxic interfaces to attach larger functional biomolecules. Monitoring the modifications of the optical properties of the hybrid molecule-QD systems by grafting various types of air-stable diazonium salts onto the QD structures...

  5. SAGA: a hybrid search algorithm for Bayesian Network structure learning of transcriptional regulatory networks.

    Science.gov (United States)

    Adabor, Emmanuel S; Acquaah-Mensah, George K; Oduro, Francis T

    2015-02-01

    Bayesian Networks have been used for the inference of transcriptional regulatory relationships among genes, and are valuable for obtaining biological insights. However, finding optimal Bayesian Network (BN) is NP-hard. Thus, heuristic approaches have sought to effectively solve this problem. In this work, we develop a hybrid search method combining Simulated Annealing with a Greedy Algorithm (SAGA). SAGA explores most of the search space by undergoing a two-phase search: first with a Simulated Annealing search and then with a Greedy search. Three sets of background-corrected and normalized microarray datasets were used to test the algorithm. BN structure learning was also conducted using the datasets, and other established search methods as implemented in BANJO (Bayesian Network Inference with Java Objects). The Bayesian Dirichlet Equivalence (BDe) metric was used to score the networks produced with SAGA. SAGA predicted transcriptional regulatory relationships among genes in networks that evaluated to higher BDe scores with high sensitivities and specificities. Thus, the proposed method competes well with existing search algorithms for Bayesian Network structure learning of transcriptional regulatory networks.

  6. Modular Hybrid Energy Concept Employing a Novel Control Structure Based on a Simple Analog System

    Directory of Open Access Journals (Sweden)

    PETREUS, D.

    2016-05-01

    Full Text Available This paper proposes a novel control topology which enables the setup of a low cost analog system leading to the implementation of a modular energy conversion system. The modular concept is based on hybrid renewable energy (solar and wind and uses high voltage inverters already available on the market. An important feature of the proposed topology is a permanently active current loop, which assures short circuit protection and simplifies the control loops compensation. The innovative analogue solution of the control structure is based on a dedicated integrated circuit (IC for power factor correction (PFC circuits, used in a new configuration, to assure an efficient inverter start-up. The energy conversion system (control structure and maximum power point tracking algorithm is simulated using a new macromodel-based concept, which reduces the usual computational burden of the simulator and achieves high processing speed. The proposed novel system is presented in this article from concept, through the design and implementation stages, is verified through simulation and is validated by experimental results.

  7. A Hybrid Vector Quantization Combining a Tree Structure and a Voronoi Diagram

    Directory of Open Access Journals (Sweden)

    Yeou-Jiunn Chen

    2014-01-01

    Full Text Available Multimedia data is a popular communication medium, but requires substantial storage space and network bandwidth. Vector quantization (VQ is suitable for multimedia data applications because of its simple architecture, fast decoding ability, and high compression rate. Full-search VQ can typically be used to determine optimal codewords, but requires considerable computational time and resources. In this study, a hybrid VQ combining a tree structure and a Voronoi diagram is proposed to improve VQ efficiency. To efficiently reduce the search space, a tree structure integrated with principal component analysis is proposed, to rapidly determine an initial codeword in low-dimensional space. To increase accuracy, a Voronoi diagram is applied to precisely enlarge the search space by modeling relations between each codeword. This enables an optimal codeword to be efficiently identified by rippling an optimal neighbor from parts of neighboring Voronoi regions. The experimental results demonstrated that the proposed approach improved VQ performance, outperforming other approaches. The proposed approach also satisfies the requirements of handheld device application, namely, the use of limited memory and network bandwidth, when a suitable number of dimensions in principal component analysis is selected.

  8. Synthesis and structures of new hybrid fluorides templated by tetraprotonated pentaerythrityl tetramine

    Science.gov (United States)

    Adil, K.; Goreshnik, E.; Courant, S.; Dujardin, G.; Leblanc, M.; Maisonneuve, V.

    2004-11-01

    A new route to synthetize the pentaerythrityl tetramine ( tetra), C(CH 2NH 2) 4, is established with a good overall yield (75-80%) and four hybrid fluorides, templated by tetra, are synthetized by hydrothermal technique and microwave heating: cis-[H 4tetra]•(AlF 5) 2 ( I), trans-[H 4tetra]•(AlF 5) 2 ( II), [H 4tetra]•(AlF 6)•(Cl) ( III) and (H 3O)•[H 4tetra] 2•(Ga(OH) 2F 4)•(GaF 6) 2•2H 2O ( IV). Structural determinations are performed from single crystal X-ray diffraction data. Structures of I and II are built up from infinite (∞ chains of corner sharing AlF 6 octahedra; the octahedra are cis-connected in I and trans-connected in II. III and IV are molecular phases and consist of isolated AlF 6 ( III) or Ga(OH) 2F 4 and GaF 6 ( IV) octahedra. Isolated chloride ions are found in III. Charge balance is ensured by tetraprotonated amine [ and the cohesion between inorganic and organic parts is due to hydrogen bonds.

  9. Analysis of SMA Hybrid Composite Structures in MSC.Nastran and ABAQUS

    Science.gov (United States)

    Turner, Travis L.; Patel, Hemant D.

    2005-01-01

    A thermoelastic constitutive model for shape memory alloy (SMA) actuators and SMA hybrid composite (SMAHC) structures was recently implemented in the commercial finite element codes MSC.Nastran and ABAQUS. The model may be easily implemented in any code that has the capability for analysis of laminated composite structures with temperature dependent material properties. The model is also relatively easy to use and requires input of only fundamental engineering properties. A brief description of the model is presented, followed by discussion of implementation and usage in the commercial codes. Results are presented from static and dynamic analysis of SMAHC beams of two types; a beam clamped at each end and a cantilever beam. Nonlinear static (post-buckling) and random response analyses are demonstrated for the first specimen. Static deflection (shape) control is demonstrated for the cantilever beam. Approaches for modeling SMAHC material systems with embedded SMA in ribbon and small round wire product forms are demonstrated and compared. The results from the commercial codes are compared to those from a research code as validation of the commercial implementations; excellent correlation is achieved in all cases.

  10. Improved PEDOT:PSS/c-Si hybrid solar cell using inverted structure and effective passivation.

    Science.gov (United States)

    Zhang, Xisheng; Yang, Dong; Yang, Zhou; Guo, Xiaojia; Liu, Bin; Ren, Xiaodong; Liu, Shengzhong Frank

    2016-10-11

    The PEDOT:PSS is often used as the window layer in the normal structured PEDOT:PSS/c-Si hybrid solar cell (HSC), leading to significantly reduced response, especially in red and near-infrared region. By depositing the PEDOT:PSS on the rear side of the c-Si wafer, we developed an inverted structured HSC with much higher solar cell response in the red and near-infrared spectrum. Passivating the other side with hydrogenated amorphous silicon (a-Si:H) before electrode deposition, the minority carrier lifetime has been significantly increased and the power conversion efficiency (PCE) of the inverted HSC is improved to as high as 16.1% with an open-circuit voltage (Voc) of 634 mV, fill factor (FF) of 70.5%, and short-circuit current density (Jsc) of 36.2 mA cm(-2), an improvement of 33% over the control device. The improvements are ascribed to inverted configuration and a-Si:H passivation, which can increase photon carrier generation and reduce carrier recombination, respectively. Both of them will benefit the photovoltaic performance and should be considered as effective design strategies to improve the performance of organic/c-Si HSCs.

  11. Salinomycin Hydroxamic Acids: Synthesis, Structure, and Biological Activity of Polyether Ionophore Hybrids.

    Science.gov (United States)

    Borgström, Björn; Huang, Xiaoli; Chygorin, Eduard; Oredsson, Stina; Strand, Daniel

    2016-06-09

    The polyether ionophore salinomycin has recently gained attention due to its exceptional ability to selectively reduce the proportion of cancer stem cells within a number of cancer cell lines. Efficient single step strategies for the preparation of hydroxamic acid hybrids of this compound varying in N- and O-alkylation are presented. The parent hydroxamic acid, salinomycin-NHOH, forms both inclusion complexes and well-defined electroneutral complexes with potassium and sodium cations via 1,3-coordination by the hydroxamic acid moiety to the metal ion. A crystal structure of an cationic sodium complex with a noncoordinating anion corroborates this finding and, moreover, reveals a novel type of hydrogen bond network that stabilizes the head-to-tail conformation that encapsulates the cation analogously to the native structure. The hydroxamic acid derivatives display down to single digit micromolar activity against cancer cells but unlike salinomycin selective reduction of ALDH(+) cells, a phenotype associated with cancer stem cells was not observed. Mechanistic implications are discussed.

  12. Covercrete with hybrid functions - A novel approach to durable reinforced concrete structures

    Energy Technology Data Exchange (ETDEWEB)

    Tang, L.; Zhang, E.Q. [Chalmers University of Technology, SE-412 96 Gothenburg (Sweden); Fu, Y. [KTH Royal Institute of Technology, SE-106 91 Stockholm (Sweden); Schouenborg, B.; Lindqvist, J.E. [CBI Swedish Cement and Concrete Research Institute, c/o SP, Box 857, SE-501 15 Boraas (Sweden)

    2012-12-15

    Due to the corrosion of steel in reinforced concrete structures, the concrete with low water-cement ratio (w/c), high cement content, and large cover thickness is conventionally used for prolonging the passivation period of steel. Obviously, this conventional approach to durable concrete structures is at the sacrifice of more CO{sub 2} emission and natural resources through consuming higher amount of cement and more constituent materials, which is against sustainability. By placing an economically affordable conductive mesh made of carbon fiber or conductive polymer fiber in the near surface zone of concrete acting as anode we can build up a cathodic prevention system with intermittent low current density supplied by, e.g., the solar cells. In such a way, the aggressive negative ions such as Cl{sup -}, CO{sub 3}{sup 2-}, and SO{sub 4}{sup 2-} can be stopped near the cathodic (steel) zone. Thus the reinforcement steel is prevented from corrosion even in the concrete with relatively high w/c and small cover thickness. This conductive mesh functions not only as electrode, but also as surface reinforcement to prevent concrete surface from cracking. Therefore, this new type of covercrete has hybrid functions. This paper presents the theoretical analysis of feasibility of this approach and discusses the potential durability problems and possible solutions to the potential problems. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Improved PEDOT:PSS/c-Si hybrid solar cell using inverted structure and effective passivation

    Science.gov (United States)

    Zhang, Xisheng; Yang, Dong; Yang, Zhou; Guo, Xiaojia; Liu, Bin; Ren, Xiaodong; Liu, Shengzhong (Frank)

    2016-10-01

    The PEDOT:PSS is often used as the window layer in the normal structured PEDOT:PSS/c-Si hybrid solar cell (HSC), leading to significantly reduced response, especially in red and near-infrared region. By depositing the PEDOT:PSS on the rear side of the c-Si wafer, we developed an inverted structured HSC with much higher solar cell response in the red and near-infrared spectrum. Passivating the other side with hydrogenated amorphous silicon (a-Si:H) before electrode deposition, the minority carrier lifetime has been significantly increased and the power conversion efficiency (PCE) of the inverted HSC is improved to as high as 16.1% with an open-circuit voltage (Voc) of 634 mV, fill factor (FF) of 70.5%, and short-circuit current density (Jsc) of 36.2 mA cm-2, an improvement of 33% over the control device. The improvements are ascribed to inverted configuration and a-Si:H passivation, which can increase photon carrier generation and reduce carrier recombination, respectively. Both of them will benefit the photovoltaic performance and should be considered as effective design strategies to improve the performance of organic/c-Si HSCs.

  14. Hybrid exchange-correlation functional for accurate prediction of the electronic and structural properties of ferroelectric oxides

    OpenAIRE

    D., I. Bilc; R., Orlando; R., Shaltaf; G., M. Rignanese; J., Íñiguez; Ph., Ghosez

    2008-01-01

    Using a linear combination of atomic orbitals approach, we report a systematic comparison of various Density Functional Theory (DFT) and hybrid exchange-correlation functionals for the prediction of the electronic and structural properties of prototypical ferroelectric oxides. It is found that none of the available functionals is able to provide, at the same time, accurate electronic and structural properties of the cubic and tetragonal phases of BaTiO$_3$ and PbTiO$_3$. Some, although not al...

  15. Influence of weave structures on the tribological properties of hybrid Kevlar/PTFE fabric composites

    Science.gov (United States)

    Gu, Dapeng; Yang, Yulin; Qi, Xiaowen; Deng, Wei; Shi, Lei

    2012-09-01

    The existing research of the woven fabric self-lubricating liner mainly focus on the tribological performance improvements and the service life raised by changing different fiber type combinations, adding additive modification, and performing fiber surface modification. As fabric composites, the weave structures play an important role in the mechanical and tribological performances of the liners. However, hardly any literature is available on the friction and wear behavior of such composites with different weave structures. In this paper, three weave structures (plain, twill 1/3 and satin 8/5) of hybrid Kevlar/PTFE fabric composites are selected and pin-on-flat linear reciprocating wear studies are done on a CETR tester under different pressures and different frequencies. The relationship between the tensile strength and the wear performance are studied. The morphologies of the worn surfaces under the typical test conditions are analyzed by means of scanning electron microscopy (SEM). The analysis results show that at 10 MPa, satin 8/5 performs the best in friction-reduction and antiwear performance, and plain is the worst. At 30 MPa, however, the antiwear performance is reversed and satin 8/5 does not even complete the 2 h wear test at 16 Hz. There is no clear evidence proving that the tensile strength has an influence on the wear performance. So the different tribological performance of the three weave structures of fabric composites may be attributed to the different PTFE proportions in the fabric surface and the different wear mechanisms. The fabric composites are divided into three regions: the lubrication region, the reinforced region and the bonding region. The major mechanisms are fatigue wear and the shear effects of the friction force in the lubrication region. In the reinforced region fiber-matrix de-bonding and fiber breakage are involved. The proposed research proposes a regional wear model and further indicates the wear process and the wear mechanism

  16. Electrical investigations of hybrid OLED microcavity structures with novel encapsulation methods

    Science.gov (United States)

    Meister, Stefan; Brückner, Robert; Fröb, Hartmut; Leo, Karl

    2016-04-01

    An electrical driven organic solid state laser is a very challenging goal which is so far well beyond reach. As a step towards realization, we monolithically implemented an Organic Light Emitting Diode (OLED) into a dielectric, high quality microcavity (MC) consisting of two Distributed Bragg Reectors (DBR). In order to account for an optimal optical operation, the OLED structure has to be adapted. Furthermore, we aim to excite the device not only electrically but optically as well. Different OLED structures with an emission layer consisting of Alq3:DCM (2 wt%) were investigated. The External Quantum Efficiencies (EQE) of this hybrid structures are in the range of 1-2 %, as expected for this material combination. Including metal layers into a MC is complicated and has a huge impact on the device performance. Using Transfer-Matrix-Algorithm (TMA) simulations, the best positions for the metal electrodes are determined. First, the electroluminescence (EL) of the adjusted OLED structure on top of a DBR is measured under nitrogen atmosphere. The modes showed quality factors of Q = 60. After the deposition of the top DBR, the EL is measured again and the quality factors increased up to Q = 600. Considering the two 25-nm-thick-silver contacts a Q-factor of 600 is very high. The realization of a suitable encapsulation method is important. Two approaches were successfully tested. The first method is based on the substitution of a DBR layer with a layer produced via Atomic Layer Deposition (ALD). The second method uses a 0.15-mm-thick cover glass glued on top of the DBR with a 0.23-μm-thick single-component glue layer. Due to the working encapsulation, it is possible to investigate the sample under ambient conditions.

  17. A solitary fibrous tumor of the kidney

    Directory of Open Access Journals (Sweden)

    Anuruddha M Abeygunasekera

    2015-01-01

    Full Text Available A solitary fibrous tumor (SFT is an uncommon spindle cell neoplasm that usually occurs in the pleura, but may occur in extrapleural sites. Its occurrence in the kidney is rare. We report a SFT, clinically thought to be a renal cell carcinoma arising in the kidney of a 68-year-old female. The tumor was well-circumscribed and composed of a mixture of spindle cells and dense collagenous bands. Immunohistochemical studies revealed reactivity for CD34, CD99, and Bcl-2 protein, with no staining for keratin or muscle markers, confirming the diagnosis. The immunohistochemical study was the key to diagnosis. Several younger members of her family had colorectal and lung cancers suggesting the possibility of a familial or genetic susceptibility.

  18. Solitary waves of the splitted RLW equation

    Science.gov (United States)

    Zaki, S. I.

    2001-07-01

    A combination of the splitting method and the cubic B-spline finite elements is used to solve the non-linear regularized long wave (RLW) equation. This approach involves a Bubnov-Galerkin method with cubic B-spline finite elements so that there is continuity of the dependent variable and its first derivative throughout the solution region. Time integration of the resulting systems is effected using a Crank-Nicholson approximation. In simulations of the migration of a single solitary wave this algorithm is shown to have higher accuracy and better conservation than a recent splitting difference scheme based on cubic spline interpolation functions, for different amplitudes ranging from a very small ( ⩾0.03) to a considerably high amplitudes ( ⩽0.3). The development of an undular bore is modeled.

  19. Numerical Simulation of Solitary Kinetic Alfven Waves

    Institute of Scientific and Technical Information of China (English)

    DING Jian; LI Yi; WANG Shui

    2008-01-01

    Using the two-fluid model in the case of α1 (α=β/2Q, β is the ratio of thermal pressure to magnetic pressure, and Q=m,e/m,I), we numerically investigate the interactions between two solitary kinetic Alfven waves (SKAWs) and between an SKAW and a density discontinuity. The results show that the two SKAWs would remain in their original shapes and propagate at their initiating speeds, which indicates that SKAWs behave just like standard solitons. The simulation also shows that SKAWs will reflect and refract when crossing a discontinuity and propagating into a higher density region. The transmission wave is an SKAW with increasing density, and the reverberation is a disturbance with lower amplitude.

  20. Benign solitary solid cold thyroid nodules

    DEFF Research Database (Denmark)

    Døssing, Helle; Bennedbaek, Finn Noe; Karstrup, Steen;

    2002-01-01

    PURPOSE: To evaluate the effects of ultrasonography (US)-guided interstitial laser photocoagulation (ILP) on the volume of benign solitary solid cold thyroid nodules and any nodule-related symptoms. MATERIALS AND METHODS: ILP was performed in 16 patients with normal thyroid function and a solid...... to evaluate the size of the untreated thyroid nodule. RESULTS: In the 16 patients treated with ILP, the mean thyroid nodule volume decreased from 10 to 5.4 mL (P .... Pressure symptoms were significantly reduced (P =.0002) after 6 months. The treatment was well-tolerated in all patients. No significant change in thyroid nodule volume was seen in the control group. CONCLUSION: US-guided ILP could become a useful nonsurgical alternative in the treatment of the benign...

  1. Solitary Plasmacytoma of the Chest Wall

    Directory of Open Access Journals (Sweden)

    Servet Kayhan

    2014-03-01

    Full Text Available A previously healthy 55-year-old man with right sided lateral chest pain admitted to clinic. It was found a solid and painful mass at the right 4th rib in physical examination. Chest X-ray and thoracic computarized tomography showed an opacity measured 60x33 mm within the right chest wall destructing the 4th rib. Needle aspiration was performed from tumor and cytologic examination showed atypic plasma cell infiltration. The patient was scheduled for a chest wall resection and reconstructive surgery. Examination of a permanent section showed that the chest wall tumor was solitary plasmacytoma. There was no evidence of multiple myeloma recurrence after two years from the operation.

  2. Transparent lattices and their solitary waves.

    Science.gov (United States)

    Sadurní, E

    2014-09-01

    We provide a family of transparent tight-binding models with nontrivial potentials and site-dependent hopping parameters. Their feasibility is discussed in electromagnetic resonators, dielectric slabs, and quantum-mechanical traps. In the second part of the paper, the arrays are obtained through a generalization of supersymmetric quantum mechanics in discrete variables. The formalism includes a finite-difference Darboux transformation applied to the scattering matrix of a periodic array. A procedure for constructing a hierarchy of discrete Hamiltonians is indicated and a particular biparametric family is given. The corresponding potentials and hopping functions are identified as solitary waves, pointing to a discrete spinorial generalization of the Korteweg-deVries family.

  3. First Principles Study on the Electronic Structure and Interface Stability of Hybrid Silicene/Fluorosilicene Nanoribbons

    National Research Council Canada - National Science Library

    Jiang, Q G; Zhang, J F; Ao, Z M; Wu, Y P

    2015-01-01

    The interface stability of hybrid silicene/fluorosilicene nanoribbons (SFNRs) has been investigated by using density functional theory calculations, where fluorosilicene is the fully fluorinated silicene...

  4. Solitary Fibrous Tumor of the Cerebello-Pontine Angle

    Science.gov (United States)

    Biggs, Nigel D.; Fagan, Paul A.; Turner, Jennifer J.; Doust, Bruce

    1999-01-01

    A case is presented of solitary fibrous tumor occurring in the cerebello-pontine angle. There have been only two other reported cases of a solitary fibrous tumors in this region. Imaging studies showed the tumor to be characteristic in shape and position of an acoustic tumor. However, at surgery the tumor was found to have a “rock hard” consistency. Solitary fibrous tumor differs from acoustic schwannoma and meningioma in its histopathological features and in this case, regrowth, after incomplete excision, was extremely rapid. ImagesFigure 2Figure 3Figure 4Figure 5Figure 6 PMID:17171119

  5. Generation of Solitary Rossby Waves by Unstable Topography

    Institute of Scientific and Technical Information of China (English)

    YANG Hong-Wei; YIN Bao-Shu; DONG Huan-He

    2012-01-01

    The effect of topography on generation of the solitary Rossby waves is researched. Here, the topography, as a forcing for waves generation, is taken as a function of longitude variable x and time variable t, which is called unstable topography. With the help of a perturbation expansion method, a forced mKdv equation governing the evolution of amplitude of the solitary Rossby waves is derived from quasi-geostrophic vortieity equation and is solved by the pseudo-spectral method. Basing on the waterfall plots, the generational features of the solitary Rossby waves under the influence of unstable topography and stable topography are compared and some conclusions are obtained.

  6. Multiple-Stage Structure Transformation of Organic-Inorganic Hybrid Perovskite CH3NH3PbI3

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Qiong; Liu, Henan; Kim, Hui-Seon; Liu, Yucheng; Yang, Mengjin; Yue, Naili; Ren, Gang; Zhu, Kai; Liu, Shengzhong; Park, Nam-Gyu; Zhang, Yong

    2016-09-15

    By performing spatially resolved Raman and photoluminescence spectroscopy with varying excitation wavelength, density, and data acquisition parameters, we achieve a unified understanding towards the spectroscopy signatures of the organic-inorganic hybrid perovskite, transforming from the pristine state (CH3NH3PbI3) to the fully degraded state (i.e., PbI2) for samples with varying crystalline domain size from mesoscopic scale (approximately 100 nm) to macroscopic size (centimeters), synthesized by three different techniques. We show that the hybrid perovskite exhibits multiple stages of structure transformation occurring either spontaneously or under light illumination, with exceptionally high sensitivity to the illumination conditions (e.g., power, illumination time, and interruption pattern). We highlight four transformation stages (stages I-IV, with stage I being the pristine state) along either the spontaneous or photoinduced degradation path exhibiting distinctly different Raman spectroscopy features at each stage, and point out that previously reported Raman spectra in the literature reflect highly degraded structures of either stage III or stage IV. Additional characteristic optical features of partially degraded materials under the joint action of spontaneous and photodegradation are also given. This study offers reliable benchmark results for understanding the intrinsic material properties and structure transformation of this unique category of hybrid materials, and the findings are pertinently important to a wide range of potential applications where the hybrid material is expected to function in greatly different environment and light-matter interaction conditions.

  7. Photochromic hybrid organic-inorganic liquid-crystalline materials built from nonionic surfactants and polyoxometalates: elaboration and structural study.

    Science.gov (United States)

    Poulos, Andreas S; Constantin, Doru; Davidson, Patrick; Impéror, Marianne; Pansu, Brigitte; Panine, Pierre; Nicole, Lionel; Sanchez, Clément

    2008-06-17

    This work reports the elaboration and structural study of new hybrid organic-inorganic materials constructed via the coupling of liquid-crystalline nonionic surfactants and polyoxometalates (POMs). X-ray scattering and polarized light microscopy demonstrate that these hybrid materials, highly loaded with POMs (up to 18 wt %), are nanocomposites of liquid-crystalline lamellar structure (Lalpha), with viscoelastic properties close to those of gels. The interpretation of X-ray scattering data strongly suggests that the POMs are located close to the terminal -OH groups of the nonionic surfactants, within the aqueous sublayers. Moreover, these materials exhibit a reversible photochromism associated to the photoreduction of the polyanion. The photoinduced mixed-valence behavior has been characterized through ESR and UV-visible-near-IR spectroscopies that demonstrate the presence of W(V) metal cations and of the characteristic intervalence charge transfer band in the near-IR region, respectively. These hybrid nanocomposites exhibit optical properties that may be useful for applications involving UV-light-sensitive coatings or liquid-crystal-based photochromic switches. From a more fundamental point of view, these hybrid materials should be very helpful models for the study of both the static and dynamic properties of nano-objects confined within soft lamellar structures.

  8. GMA-laser Hybrid Welding of High-strength Fine-grain Structural Steel with an Inductive Preheating

    Science.gov (United States)

    Lahdo, Rabi; Seffer, Oliver; Springer, André; Kaierle, Stefan; Overmeyer, Ludger

    The industrial useof GMA-laser hybrid welding has increased in the last 10 years, due to the brilliant quality of the laser beam radiation, and higher laser output powers. GMA-laser hybrid welding processes operate in a common molten pool. The combination of the laser beam and the arc results in improved welding speed, penetration depth, heat affected zone and gap bridgeability. Single-layer, GMA-laser hybrid welding processes have been developed for high-strength fine-grain structural steels with a grade of S690QL and a thickness of 15 mm and 20 mm. In addition, the welding process is assisted by an integrated, inductive preheating process to improve the mechanical properties of the welding seam. By using the determined parameters regarding the energy per unit length, and the preheating temperature, welding seams with high quality can be achieved.

  9. Heavy-ion-acoustic solitary and shock waves in an adiabatic multi-ion plasma

    Energy Technology Data Exchange (ETDEWEB)

    Hossen, M.A.; Rahman, M.M.; Mamun, A.A., E-mail: armanplasma@gmail.com [Department of Physics, Jahangirnagar University, Savar, Dhaka (Bangladesh); Hossen, M.R. [Department of Natural Sciences, Daffodil International University, Dhanmondi, Dhaka (Bangladesh)

    2015-08-15

    The standard reductive perturbation method has been employed to derive the Korteweg-deVries (K-dV) and Burgers (BG) equations to investigate the basic properties of heavy-ion-acoustic (HIA) waves in a plasma system which is supposed to be composed of nonthermal electrons, Boltzmann distributed light ions, and adiabatic positively charged inertial heavy ions. The HIA solitary and shock structures are found to exist with either positive or negative potential. It is found that the effects of adiabaticity of inertial heavy ions, nonthermality of electrons, and number densities of plasma components significantly modify the basic properties of the HIA solitary and shock waves. The implications of our results may be helpful in understanding the electrostatic perturbations in various laboratory and astrophysical plasma environments. (author)

  10. Solitary, explosive and rational solutions for nonlinear electron-acoustic waves with non-thermal electrons

    CERN Document Server

    El-Wakil, S A; Abd-El-Hamid, H M; Abulwafa, E M

    2010-01-01

    A rigorous theoretical investigation has been made on electron acoustic wave propagating in unmagnetized collisionless plasma consisting of a cold electron fluid, non-thermal hot electrons and stationary ions. Based on the pseudo-potential approach, large amplitude potential structures and the existence of solitary waves are discussed. The reductive perturbation method has been employed to derive the Korteweg-de Vries (KdV) equation for small but finite amplitude electrostatic waves. An algebraic method with computerized symbolic computation, which greatly exceeds the applicability of the existing tanh, extended tanh methods in obtaining a series of exact solutions of the KdV equation. Numerical studies have been made using plasma parameters close to those values corresponding to the dayside auroral zone reveals different solutions i.e., bell-shaped solitary pulses, rational pulses and solutions with singularity at a finite points which called blowup solutions in addition to the propagation of an explosive pu...

  11. Electron acoustic solitary waves in a magnetized plasma with nonthermal electrons and an electron beam

    Science.gov (United States)

    Singh, S. V.; Devanandhan, S.; Lakhina, G. S.; Bharuthram, R.

    2016-08-01

    A theoretical investigation is carried out to study the obliquely propagating electron acoustic solitary waves having nonthermal hot electrons, cold and beam electrons, and ions in a magnetized plasma. We have employed reductive perturbation theory to derive the Korteweg-de-Vries-Zakharov-Kuznetsov (KdV-ZK) equation describing the nonlinear evolution of these waves. The two-dimensional plane wave solution of KdV-ZK equation is analyzed to study the effects of nonthermal and beam electrons on the characteristics of the solitons. Theoretical results predict negative potential solitary structures. We emphasize that the inclusion of finite temperature effects reduces the soliton amplitudes and the width of the solitons increases by an increase in the obliquity of the wave propagation. The numerical analysis is presented for the parameters corresponding to the observations of "burst a" event by Viking satellite on the auroral field lines.

  12. Solitary Tracheobronchial Papilloma: Cytomorphology and ancillary studies with histologic correlation

    Directory of Open Access Journals (Sweden)

    Tee U Lang

    2011-01-01

    Full Text Available Solitary tracheobronchial papilloma (STBP is a rare benign tumor that primarily involves the tracheobronchial tree. Human papilloma virus (HPV infection is associated with dysplasia and a high risk of carcinoma in these lesions. The cytomorphology of STBP is not well established in the literature. Our aim is to characterize the cytomorphologic features of STBP, with histologic correlation in a series of 6 patients - 4 males and 2 females - with a mean age of 67 years (range, 53-88 years. There were 5 biopsy-proven squamous papillomas and 1 glandular papilloma. On surgical biopsy, squamous papillomas exhibited cytological atypia (4 graded mild and 1 graded moderate with focal severe dysplasia, surface erosion, and inflammation. Cytology specimens available for review included a combination of 4 fine-needle aspirations (FNAs, 2 bronchoalveolar lavages and 2 (of 3 bronchial brushings. Cytologic findings associated with squamous papillomas included atypical squamous cells and rare squamous cell resembling koilocyte in 1 bronchial brushing. Sheets of squamous cells were identified in another specimen. Several cases had a prominent background of acute inflammation, and candida was present in 1 specimen. HPV in-situ hybridization was positive in 1 case and negative in 2 cases. A p16 immunocytochemical stain performed on 1 cell block was negative. In conclusion, although STBP is a rare neoplasm, these cases may be encountered in respiratory cytology samples. FNA of papillomas yields fewer lesional cells compared to exfoliative samples. These lesions may be mistaken in cytology specimens for squamous cell carcinoma, squamous-lined cavitary lesions, an infectious (fungal process, reactive squamous metaplasia, or oral contamination.

  13. A structured modeling approach for dynamic hybrid fuzzy-first principles models

    NARCIS (Netherlands)

    Lith, van Pascal F.; Betlem, Ben H.L.; Roffel, Brian

    2002-01-01

    Hybrid fuzzy-first principles models can be attractive if a complete physical model is difficult to derive. These hybrid models consist of a framework of dynamic mass and energy balances, supplemented with fuzzy submodels describing additional equations, such as mass transformation and transfer rate

  14. Head-on collision and overtaking collision between an envelope solitary wave and a KdV solitary wave in a dusty plasma.

    Science.gov (United States)

    Zhang, Heng; Duan, Wen-Shan; Qi, Xin; Yang, Lei

    2016-02-12

    Head-on collision and overtaking collision between a KdV solitary wave and an envelope solitary wave are first studied in present paper by using Particle-in-cell (PIC) method in a dusty plasma. There are phase shifts of the KdV solitary wave in both head-on collision and the overtaking collision, while no phase shift is found for the envelop solitary wave in any cases. The remarkable difference between head-on collision and the overtaking collision is that the phase shift of KdV solitary wave increases as amplitude of KdV solitary wave increases in head-on collision, while it decreases as amplitude of the KdV solitary wave increases in the overtaking collision. It is found that the maximum amplitude during the collision process is less than sum of two amplitudes of both solitary waves, but is larger than either of the amplitude.

  15. A plethora of generalised solitary gravity-capillary water waves

    CERN Document Server

    Clamond, Didier; Duran, Angel

    2014-01-01

    The present study describes, first, an efficient algorithm for computing gravity-capillary solitary waves solutions of the irrotational Euler equations and, second, provides numerical evidences of the existence of (likely) an infinite number of generalised solitary waves (i.e. solitary waves with undamped oscillatory wings). Using conformal mapping, the unknown fluid domain (which is to be determined) is mapped into a uniform strip of the complex plane. A Babenko-like equation is then derived from a Lagrangian expressed in the transformed domain. The Babenko equation is then solved numerically using a Levenberg-Marquardt algorithm. Various interesting solutions are computed, some of them being known, some seem to be new. The emergence of generalised solitary waves is shown when the Bond number is increased.

  16. Oblique solitary waves in a five component plasma

    Energy Technology Data Exchange (ETDEWEB)

    Sijo, S.; Manesh, M.; Sreekala, G.; Venugopal, C., E-mail: cvgmgphys@yahoo.co.in [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, 686 560 Kerala (India); Neethu, T. W. [Department of Physics, CMS College, Mahatma Gandhi University, Kottayam, 686 001 Kerala (India); Renuka, G. [Kerala State Council for Science, Technology and Environment, Thiruvananthapuram, 695 004 Kerala (India)

    2015-12-15

    We investigate the influence of a second electron component on oblique dust ion acoustic solitary waves in a five component plasma consisting of positively and negatively charged dust, hydrogen ions, and hotter and colder electrons. Of these, the heavier dust and colder photo-electrons are of cometary origin while the other two are of solar origin; electron components are described by kappa distributions. The K-dV equation is derived, and different attributes of the soliton such as amplitude and width are plotted for parameters relevant to comet Halley. We find that the second electron component has a profound influence on the solitary wave, decreasing both its amplitude and width. The normalized hydrogen density strongly influences the solitary wave by decreasing its width; the amplitude of the solitary wave, however, increases with increasing solar electron temperatures.

  17. Solitary pulmonary granuloma with marked enhancement on dynamic CT scanning

    Energy Technology Data Exchange (ETDEWEB)

    Stark, P.; Wong, V.; Gold, P.

    1988-10-01

    A patient is described who presented with a vividly enhancing solitary pulmonary nodule during dynamic CT scanning. This mass proved to represent a granuloma due to coccidioidomycosis. The presumptive mechanism of enhancement as well as the differential diagnosis are discussed.

  18. Protein loop modeling using a new hybrid energy function and its application to modeling in inaccurate structural environments.

    Directory of Open Access Journals (Sweden)

    Hahnbeom Park

    Full Text Available Protein loop modeling is a tool for predicting protein local structures of particular interest, providing opportunities for applications involving protein structure prediction and de novo protein design. Until recently, the majority of loop modeling methods have been developed and tested by reconstructing loops in frameworks of experimentally resolved structures. In many practical applications, however, the protein loops to be modeled are located in inaccurate structural environments. These include loops in model structures, low-resolution experimental structures, or experimental structures of different functional forms. Accordingly, discrepancies in the accuracy of the structural environment assumed in development of the method and that in practical applications present additional challenges to modern loop modeling methods. This study demonstrates a new strategy for employing a hybrid energy function combining physics-based and knowledge-based components to help tackle this challenge. The hybrid energy function is designed to combine the strengths of each energy component, simultaneously maintaining accurate loop structure prediction in a high-resolution framework structure and tolerating minor environmental errors in low-resolution structures. A loop modeling method based on global optimization of this new energy function is tested on loop targets situated in different levels of environmental errors, ranging from experimental structures to structures perturbed in backbone as well as side chains and template-based model structures. The new method performs comparably to force field-based approaches in loop reconstruction in crystal structures and better in loop prediction in inaccurate framework structures. This result suggests that higher-accuracy predictions would be possible for a broader range of applications. The web server for this method is available at http://galaxy.seoklab.org/loop with the PS2 option for the scoring function.

  19. PLLA-collagen and PLLA-gelatin hybrid scaffolds with funnel-like porous structure for skin tissue engineering

    Science.gov (United States)

    Lu, Hongxu; Oh, Hwan Hee; Kawazoe, Naoki; Yamagishi, Kozo; Chen, Guoping

    2012-12-01

    In skin tissue engineering, a three-dimensional porous scaffold is necessary to support cell adhesion and proliferation and to guide cells moving into the repair area in the wound healing process. Structurally, the porous scaffold should have an open and interconnected porous architecture to facilitate homogenous cell distribution. Moreover, the scaffolds should be mechanically strong to protect deformation during the formation of new skin. In this study, the hybrid scaffolds were prepared by forming funnel-like collagen or gelatin sponge on a woven poly(l-lactic acid) (PLLA) mesh. The hybrid scaffolds combined the advantages of both collagen or gelatin (good cell-interactions) and PLLA mesh (high mechanical strength). The hybrid scaffolds were used to culture dermal fibroblasts for dermal tissue engineering. The funnel-like porous structure promoted homogeneous cell distribution and extracellular matrix production. The PLLA mesh reinforced the scaffold to avoid deformation. Subcutaneous implantation showed that the PLLA-collagen and PLLA-gelatin scaffolds promoted the regeneration of dermal tissue and epidermis and reduced contraction during the formation of new tissue. These results indicate that funnel-like hybrid scaffolds can be used for skin tissue regeneration.

  20. Novel lanthanide hybrid functional materials for high performance luminescence application: The relationship between structures and photophysical behaviors

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jun [Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China); Jia, Lei [Department of Physics and Chemistry, Henan Polytechnic University, Jiaozuo 454000 (China); Ma, Yufei; Liu, Xiao; Tian, Hao; Liu, Weisheng [Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China); Tang, Yu, E-mail: tangyu@lzu.edu.cn [Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China)

    2012-09-14

    Functional luminescent hybrid materials have emerged as fascinating and promising materials for their versatile applications. In this report, novel efficient luminescent lanthanide (Tb{sup 3+}, Eu{sup 3+}) hybrid materials with a new kind of amide-type {beta}-diketone ligands covalently bonded to the silica gels have been assembled through the sol-gel progresses. The hybrid materials have been characterized by the Fourier transform infrared (FTIR) spectra, UV-vis absorption spectra, powder X-ray diffraction (PXRD), scanning electron microscope (SEM), and thermal analyses. The relationship between structures and photophysical behaviors of these materials was discussed in detail. The materials assembled by the precursors containing aromatic end group (Si-L{sup 1}-Ln) exhibited longer luminescence lifetimes and higher quantum efficiencies, suggesting that the existence of a suitable conjugated system should allow a more efficient energy transfer. Under UV irradiation, the materials emitted either bright green light or red light with different intensity which may lead to potential functional applications in optical devices and electronic devices. Highlights: Black-Right-Pointing-Pointer A new kind of efficient luminescent lanthanide hybrid materials has been assembled. Black-Right-Pointing-Pointer The materials can efficiently emit green or red light under UVA irradiation. Black-Right-Pointing-Pointer The relationship between photophysical behaviors and structures was discussed. Black-Right-Pointing-Pointer A suitable conjugated system should allow a more efficient energy transfer.