Big bang nucleosynthesis, the CMB, and the origin of matter and space-time

NASA Astrophysics Data System (ADS)

Mathews, Grant J.; Gangopadhyay, Mayukh; Sasankan, Nishanth; Ichiki, Kiyotomo; Kajino, Toshitaka

2018-04-01

We summarize some applications of big bang nucleosythesis (BBN) and the cosmic microwave background (CMB) to constrain the first moments of the creation of matter in the universe. We review the basic elements of BBN and how it constraints physics of the radiation-dominated epoch. In particular, how the existence of higher dimensions impacts the cosmic expansion through the projection of curvature from the higher dimension in the "dark radiation" term. We summarize current constraints from BBN and the CMB on this brane-world dark radiation term. At the same time, the existence of extra dimensions during the earlier inflation impacts the tensor to scalar ratio and the running spectral index as measured in the CMB. We summarize how the constraints on inflation shift when embedded in higher dimensions. Finally, one expects that the universe was born out of a complicated multiverse landscape near the Planck time. In these moments the energy scale of superstrings was obtainable during the early moments of chaotic inflation. We summarize the quest for cosmological evidence of the birth of space-time out of the string theory landscape. We will explore the possibility that a superstring excitations may have made itself known via a coupling to the field of inflation. This may have left an imprint of "dips" in the power spectrum of temperature fluctuations in the cosmic microwave background. The identification of this particle as a superstring is possible because there may be evidence for different oscillator states of the same superstring that appear on different scales on the sky. It will be shown that from this imprint one can deduce the mass, number of oscillations, and coupling constant for the superstring. Although the evidence is marginal, this may constitute the first observation of a superstring in Nature.

Type IIB supergravity solution for the T-dual of the η-deformed AdS 5 × S 5 superstring

NASA Astrophysics Data System (ADS)

Hoare, B.; Tseytlin, A. A.

2015-10-01

We find an exact type IIB supergravity solution that represents a one-parameter deformation of the T-dual of the AdS 5 × S 5 background (with T-duality applied in all 6 abelian bosonic isometric directions). The non-trivial fields are the metric, dilaton and RR 5-form only. The latter has remarkably simple "undeformed" form when written in terms of a "deformation-rotated" vielbein basis. An unusual feature of this solution is that the dilaton contains a linear dependence on the isometric coordinates of the metric precluding a straightforward reversal of T-duality. If we still formally dualize back, we find exactly the metric, B-field and product of dilaton with RR field strengths as recently extracted from the η-deformed AdS 5 × S 5 superstring action in arXiv:1507.04239. We also discuss similar solutions for deformed AdS n × S n backgrounds with n = 2 , 3. In the η → i limit we demonstrate that all these backgrounds can be interpreted as special limits of gauged WZW models and are also related to (a limit of) the Pohlmeyer-reduced models of the AdS n × S n superstrings.

Supergravitational conformal Galileons

NASA Astrophysics Data System (ADS)

Deen, Rehan; Ovrut, Burt

2017-08-01

The worldvolume actions of 3+1 dimensional bosonic branes embedded in a five-dimensional bulk space can lead to important effective field theories, such as the DBI conformal Galileons, and may, when the Null Energy Condition is violated, play an essential role in cosmological theories of the early universe. These include Galileon Genesis and "bouncing" cosmology, where a pre-Big Bang contracting phase bounces smoothly to the presently observed expanding universe. Perhaps the most natural arena for such branes to arise is within the context of superstring and M -theory vacua. Here, not only are branes required for the consistency of the theory, but, in many cases, the exact spectrum of particle physics occurs at low energy. However, such theories have the additional constraint that they must be N = 1 supersymmetric. This motivates us to compute the worldvolume actions of N = 1 supersymmetric three-branes, first in flat superspace and then to generalize them to N = 1 supergravitation. In this paper, for simplicity, we begin the process, not within the context of a superstring vacuum but, rather, for the conformal Galileons arising on a co-dimension one brane embedded in a maximally symmetric AdS 5 bulk space. We proceed to N = 1 supersymmetrize the associated worldvolume theory and then generalize the results to N = 1 supergravity, opening the door to possible new cosmological scenarios

Gain enhancement with near-zero-index metamaterial superstrate

NASA Astrophysics Data System (ADS)

Bouzouad, M.; Chaker, S. M.; Bensafielddine, D.; Laamari, E. M.

2015-11-01

The objective of this paper was to use a near-zero-index ( n) metamaterial as a single- or a double-layer superstrate suspended above a microstrip patch antenna, operating at 43 GHz, for the gain enhancement. The single metamaterial layer superstrate consists of a periodic arrangement of Jerusalem cross unit cells and behaves as an homogeneous medium characterized by a refractive index close to zero. This metamaterial property allows gathering radiated waves from the antenna and collimates them toward the superstrate normal direction. The proposed design improves the antenna gain by 5.1 dB with the single-layer superstrate and 7 dB with the double-layer superstrate.

Compactification and inflation in the superstring theory from the condensation of gravitino pairs

NASA Astrophysics Data System (ADS)

Pollock, M. D.

1987-12-01

We discuss the possibility that inflation can occur in the E8×E8' heterotic superstring theory, if there is a pair condensation of the gravitino field ψA and also of the Majorana-Weyl spinor λ, as suggested by the Helayël-Neto and Smith. In the absence of a condensation of the anti-symmetric tensor field HMNP, then the associated potential V(θ,φ) is bounded from below and independent of the dilaton field φ. It can be made to vanish at the minimum, where the compactification scale θ is fixed. Alternatively, a small cosmological constant may remain (ultimately to be cancelled by radiative corrections at the lower energy scale of the gaugino condensation), which could in principle lead to inflation. Present address: Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Bombay 400 005, India.

Supergravitational conformal Galileons

DOE PAGES

Deen, Rehan; Ovrut, Burt

2017-08-04

The worldvolume actions of 3+1 dimensional bosonic branes embedded in a five-dimensional bulk space can lead to important effective field theories, such as the DBI conformal Galileons, and may, when the Null Energy Condition is violated, play an essential role in cosmological theories of the early universe. These include Galileon Genesis and “bouncing” cosmology, where a pre-Big Bang contracting phase bounces smoothly to the presently observed expanding universe. Perhaps the most natural arena for such branes to arise is within the context of superstring and M -theory vacua. Here, not only are branes required for the consistency of the theory,more » but, in many cases, the exact spectrum of particle physics occurs at low energy. However, such theories have the additional constraint that they must be N = 1 supersymmetric. This motivates us to compute the worldvolume actions of N = 1 supersymmetric three-branes, first in flat superspace and then to generalize them to N = 1 supergravitation. In this paper, for simplicity, we begin the process, not within the context of a superstring vacuum but, rather, for the conformal Galileons arising on a co-dimension one brane embedded in a maximally symmetric AdS 5 bulk space. We proceed to N = 1 supersymmetrize the associated worldvolume theory and then generalize the results to N = 1 supergravity, opening the door to possible new cosmological scenarios« less

Supergravitational conformal Galileons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deen, Rehan; Ovrut, Burt

The worldvolume actions of 3+1 dimensional bosonic branes embedded in a five-dimensional bulk space can lead to important effective field theories, such as the DBI conformal Galileons, and may, when the Null Energy Condition is violated, play an essential role in cosmological theories of the early universe. These include Galileon Genesis and “bouncing” cosmology, where a pre-Big Bang contracting phase bounces smoothly to the presently observed expanding universe. Perhaps the most natural arena for such branes to arise is within the context of superstring and M -theory vacua. Here, not only are branes required for the consistency of the theory,more » but, in many cases, the exact spectrum of particle physics occurs at low energy. However, such theories have the additional constraint that they must be N = 1 supersymmetric. This motivates us to compute the worldvolume actions of N = 1 supersymmetric three-branes, first in flat superspace and then to generalize them to N = 1 supergravitation. In this paper, for simplicity, we begin the process, not within the context of a superstring vacuum but, rather, for the conformal Galileons arising on a co-dimension one brane embedded in a maximally symmetric AdS 5 bulk space. We proceed to N = 1 supersymmetrize the associated worldvolume theory and then generalize the results to N = 1 supergravity, opening the door to possible new cosmological scenarios« less

Priming the search for cosmic superstrings using GADGET2 simulations

NASA Astrophysics Data System (ADS)

Cousins, Bryce; Jia, Hewei; Braverman, William; Chernoff, David

2018-01-01

String theory is an extensive mathematical theory which, despite its broad explanatory power, is still lacking empirical support. However, this may change when considering the scope of cosmology, where “cosmic superstrings” may serve as observational evidence. According to string theory, these superstrings were stretched to cosmic scales in the early Universe and may now be detectable, via microlensing or gravitational radiation. Negative results from prior surveys have put some limits on superstring properties, so to investigate the parameter space more effectively, we ask: “where should we expect to find cosmic superstrings, and how many should we predict?” This research investigates these questions by simulating cosmic string behavior during structure formation in the universe using GADGET2. The sizes and locations of superstring clusters are assessed using kernel density estimation and radial correlation functions. Currently, only preliminary small-scale simulations have been performed, producing superstring clustering with low sensitivity. However, future simulations of greater magnitude will offer far higher resolution, allowing us to more precisely track superstring behavior within structures. Such results will guide future searches, most imminently those made possible by LSST and WFIRST.

Democratic superstring field theory: gauge fixing

NASA Astrophysics Data System (ADS)

Kroyter, Michael

2011-03-01

We show that a partial gauge fixing of the NS sector of the democratic-picture superstring field theory leads to the non-polynomial theory. Moreover, by partially gauge fixing the Ramond sector we obtain a non-polynomial fully RNS theory at pictures 0 and 1/2 . Within the democratic theory and in the partially gauge fixed theory the equations of motion of both sectors are derived from an action. We also discuss a representation of the non-polynomial theory analogous to a manifestly two-dimensional representation of WZW theory and the action of bosonic pure-gauge solutions. We further demonstrate that one can consistently gauge fix the NS sector of the democratic theory at picture number -1. The resulting theory is new. It is a {mathbb{Z}_2} dual of the modified cubic theory. We construct analytical solutions of this theory and show that they possess the desired properties.

On the dynamics of superstring compactification

NASA Astrophysics Data System (ADS)

Pollock, M. D.

2018-05-01

Compactification of the ten-dimensional heterotic superstring theory to four dimensions gives rise to two moduli potentials VA, VB, the positive semi-definiteness of which places constraints on the Euler characteristic \\bar{χ} of the internal space \\bar{g}_{μν}(y^{ξ}) and the adiabatic index γ of the effective matter source of energy-density ρ and pressure p = (γ -1)ρ that generates the physical four-space g_{ij}(xk), namely \\bar{χ} < 0, 4/3 ≤ γ ≤ 2, or \\bar{χ} > 0, 1 ≤ γ ≤ 4/3. Here, we show how fermion-bilinear condensation in the internal space, first put forward by Helayël-Neto and Smith, determines the field \\tilde{β} ≡ A_r B_r3, thus reducing the moduli space to a single canonical field \\tilde{σ}=2σB with a potential ˜ , which is positive semi-definite under the same conditions that ensure positive semi-definiteness of VA, VB, and has a minimum at a value of \\tilde{β} that is approximately constant far from the Planck era at t ≫ t_P. The fields σA, σB, which are canonically normalized in the zero-slope limit, are modified by contributions originating from the higher-derivative gravitational terms α^' \\hatR_E2 and α^' 3} \\hatR4, but the associated kinetic energy remains positive for times t ≳ t_P/2, guaranteeing classical stability of the solution, since the generalized indeterminacy principle implies a minimum physically measurable time t0 ≈ 50 t_P for the superstring theory.

Small field axion inflation with sub-Planckian decay constant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kadota, Kenji; Kobayashi, Tatsuo; Oikawa, Akane

2016-10-10

We study an axion inflation model recently proposed within the framework of type IIB superstring theory, where we pay a particular attention to a sub-Planckian axion decay constant. Our axion potential can lead to the small field inflation with a small tensor-to-scalar ratio, and a typical reheating temperature can be as low as GeV.

Effect of two different superstrate layers on bismuth titanate (BiT) array antennas.

PubMed

Wee, F H; Malek, F; Al-Amani, A U; Ghani, Farid

2014-01-15

The microwave industry has shown increasing interest in electronic ceramic material (ECM) due to its advantages, such as light weight, low cost, low loss, and high dielectric strength. In this paper, simple antennas covered by superstrate layers for 2.30 GHz to 2.50 GHz are proposed. The antennas are compact and have the capability of producing high performance in terms of gain, directivity, and radiation efficiency. Bismuth titanate with high dielectric constant of 21, was utilized as the ECM, while the superstrate layers chosen included a split ring resonator and dielectric material. The superstrate layers were designed for some improvement in the performance of directivity, gain, and return loss. The proposed antennas were simulated and fabricated. The results obtained were small antennas that possess high gain and high directivity with 360°, omni-directional signal transmission that resonant types of conventional dipole antenna cannot achieve. The gain of the antenna with the superstrate layer was enhanced by about 1 dBi over the antenna without a superstrate layer at 2.40 GHz.

Effect of Two Different Superstrate Layers On Bismuth Titanate (BiT) Array Antennas

NASA Astrophysics Data System (ADS)

Wee, F. H.; Malek, F.; Al-Amani, A. U.; Ghani, Farid

2014-01-01

The microwave industry has shown increasing interest in electronic ceramic material (ECM) due to its advantages, such as light weight, low cost, low loss, and high dielectric strength. In this paper, simple antennas covered by superstrate layers for 2.30 GHz to 2.50 GHz are proposed. The antennas are compact and have the capability of producing high performance in terms of gain, directivity, and radiation efficiency. Bismuth titanate with high dielectric constant of 21, was utilized as the ECM, while the superstrate layers chosen included a split ring resonator and dielectric material. The superstrate layers were designed for some improvement in the performance of directivity, gain, and return loss. The proposed antennas were simulated and fabricated. The results obtained were small antennas that possess high gain and high directivity with 360°, omni-directional signal transmission that resonant types of conventional dipole antenna cannot achieve. The gain of the antenna with the superstrate layer was enhanced by about 1 dBi over the antenna without a superstrate layer at 2.40 GHz.

Qubit and fermionic Fock spaces from type II superstring black holes

NASA Astrophysics Data System (ADS)

Belhaj, A.; Bensed, M.; Benslimane, Z.; Sedra, M. B.; Segui, A.

Using Hodge diagram combinatorial data, we study qubit and fermionic Fock spaces from the point of view of type II superstring black holes based on complex compactifications. Concretely, we establish a one-to-one correspondence between qubits, fermionic spaces and extremal black holes in maximally supersymmetric supergravity obtained from type II superstring on complex toroidal and Calabi-Yau compactifications. We interpret the differential forms of the n-dimensional complex toroidal compactification as states of n-qubits encoding information on extremal black hole charges. We show that there are 2n copies of n qubit systems which can be split as 2n = 2n-1 + 2n-1. More precisely, 2n-1 copies are associated with even D-brane charges in type IIA superstring and the other 2n-1 ones correspond to odd D-brane charges in IIB superstring. This correspondence is generalized to a class of Calabi-Yau manifolds. In connection with black hole charges in type IIA superstring, an n-qubit system has been obtained from a canonical line bundle of n factors of one-dimensional projective space ℂℙ1.

Short superstrings and the structure of overlapping strings.

PubMed

Armen, C; Stein, C

1995-01-01

Given a collection of strings S = [s1,...,sn] over an alphabet sigma, a superstring alpha of S is a string containing each si as a substring, that is, for each i, 1 < or = i < or = n, alpha contains a block of magnitude of si consecutive characters that match si exactly. The shortest superstring problem is the problem of finding a superstring alpha of minimum length. The shortest superstring problem has applications in both computational biology and data compression. The shortest superstring problem is NP-hard (Gallant et al., 1980); in fact, it was recently shown to be MAX SNP-hard (Blum et al., 1994). Given the importance of the applications, several heuristics and approximation algorithms have been proposed. Constant factor approximation algorithms have been given in Blum et al. (1994) (factor of 3), Teng and Yao (1993) (factor of 2 8/9), Czumaj et al. (1994) (factor of 2 5/6), and Kosaraju et al. (1994) (factor of 2 50/63). Informally, the key to any algorithm for the shortest superstring problem is to identify sets of strings with large amounts of similarity, or overlap. Although the previous algorithms and their analyses have grown increasingly sophisticated, they reveal remarkably little about the structure of strings with large amounts of overlap. In this sense, they are solving a more general problem than the one at hand. In this paper, we study the structure of strings with large amounts of overlap and use our understanding to give an algorithm that finds a superstring whose length is no more than 2 3/4 times that of the optimal superstring. Our algorithm runs in O(magnitude of S + n3) time, which matches that of previous algorithms. We prove several interesting properties about short periodic strings, allowing us to answer questions of the following form: Given a string with some periodic structure, characterize all the possible periodic strings that can have a large amount of overlap with the first string.

Superspace geometrical realization of the N-extended super Virasoro algebra and its dual

NASA Astrophysics Data System (ADS)

Curto, C.; Gates, S. J., Jr.; Rodgers, V. G. J.

2000-05-01

We derive properties of N-extended /GR super Virasoro algebras. These include adding central extensions, identification of all primary fields and the action of the adjoint representation on its dual. The final result suggest identification with the spectrum of fields in supergravity theories and superstring/M-theory constructed from NSR N-extended supersymmetric /GR Virasoro algebras.

PhD Thesis: String theory in the early universe

NASA Astrophysics Data System (ADS)

Gwyn, Rhiannon

2009-11-01

The intersection of string theory with cosmology is unavoidable in the early universe, and its exploration may shine light on both fields. In this thesis, three papers at this intersection are presented and reviewed, with the aim of providing a thorough and pedagogical guide to their results. First, we address the longstanding problem of finding a string theory realisation of the axion. Using warped compactifications in heterotic string theory, we show that the axion decay constant can be lowered to acceptable values by the warp factor. Next, we move to the subject of cosmic strings, whose network evolution could have important consequences for astrophysics and cosmology. In particular, there are quantitative differences between cosmic superstring networks and GUT cosmic string networks. We investigate the properties of cosmic superstring networks in warped backgrounds, giving the tension and properties of three-string junctions in these backgrounds. Finally, we examine the possibility that cosmic strings in heterotic string theory could be responsible for generating the galactic magnetic fields that seeded those observed today.

On SYM theory and all order bulk singularity structures of BPS strings in type II theory

NASA Astrophysics Data System (ADS)

Hatefi, Ehsan

2018-06-01

The complete forms of the S-matrix elements of a transverse scalar field, two world volume gauge fields, and a Potential Cn-1 Ramond-Ramond (RR) form field are investigated. In order to find an infinite number of t , s , (t + s + u)-channel bulk singularity structures of this particular mixed open-closed amplitude, we employ all the conformal field theory techniques to , exploring all the entire correlation functions and all order α‧ contact interactions to these supersymmetric Yang-Mills (SYM) couplings. Singularity and contact term comparisons with the other symmetric analysis, and are also carried out in detail. Various couplings from pull-Back of branes, Myers terms and several generalized Bianchi identities should be taken into account to be able to reconstruct all order α‧ bulk singularities of type IIB (IIA) superstring theory. Finally, we make a comment on how to derive without any ambiguity all order α‧ contact terms of this S-matrix which carry momentum of RR in transverse directions.

Multi-kW solar arrays for Earth orbit applications

NASA Technical Reports Server (NTRS)

1985-01-01

The multi-kW solar array program is concerned with developing the technology required to enable the design of solar arrays required to power the missions of the 1990's. The present effort required the design of a modular solar array panel consisting of superstrate modules interconnected to provide the structural support for the solar cells. The effort was divided into two tasks: (1) superstrate solar array panel design, and (2) superstrate solar array panel-to-panel design. The primary objective was to systematically investigate critical areas of the transparent superstrate solar array and evaluate the flight capabilities of this low cost approach.

Superstrate loading effects on the resonant characteristics of high Tc superconducting circular patch printed on anisotropic materials

NASA Astrophysics Data System (ADS)

Bedra, Sami; Bedra, Randa; Benkouda, Siham; Fortaki, Tarek

2017-12-01

In this paper, the effects of both anisotropies in the substrate and superstrate loading on the resonant frequency and bandwidth of high-Tc superconducting circular microstrip patch in a substrate-superstrate configuration are investigated. A rigorous analysis is performed using a dyadic Galerkin's method in the vector Hankel transform domain. Galerkin's procedure is employed in the spectral domain where the TM and TE modes of the cylindrical cavity with magnetic side walls are used in the expansion of the disk current. The effect of the superconductivity of the patch is taken into account using the concept of the complex resistive boundary condition. London's equations and the two-fluid model of Gorter and Casimir are used in the calculation of the complex surface impedance of the superconducting circular disc. The accuracy of the analysis is tested by comparing the computed results with previously published data for several anisotropic substrate-superstrate materials. Good agreement is found among all sets of results. The numerical results obtained show that important errors can be made in the computation of the resonant frequencies and bandwidths of the superconducting resonators when substrate dielectric anisotropy, and/or superstrate anisotropy are ignored. Other theoretical results obtained show that the superconducting circular microstrip patch on anisotropic substrate-superstrate with properly selected permittivity values along the optical and the non-optical axes combined with optimally chosen structural parameters is more advantageous than the one on isotropic substrate-superstrate by exhibiting wider bandwidth characteristic.

Special Holonomy and Two-Dimensional Supersymmetric Sigma-Models

NASA Astrophysics Data System (ADS)

Stojevic, Vid

2006-11-01

Two-dimensional sigma-models describing superstrings propagating on manifolds of special holonomy are characterized by symmetries related to covariantly constant forms that these manifolds hold, which are generally non-linear and close in a field dependent sense. The thesis explores various aspects of the special holonomy symmetries.

Sensor And Method For Detecting A Superstrate

NASA Technical Reports Server (NTRS)

Arndt, G. Dickey (Inventor); Cari, James R. (Inventor); Ngo, Phong H. (Inventor); Fink, Patrick W. (Inventor); Siekierski, James D. (Inventor)

2006-01-01

Method and apparatus are provided for determining a superstrate on or near a sensor, e.g., for detecting the presence of an ice superstrate on an airplane wing or a road. In one preferred embodiment, multiple measurement cells are disposed along a transmission line. While the present invention is operable with different types of transmission lines, construction details for a presently preferred coplanar waveguide and a microstrip waveguide are disclosed. A computer simulation is provided as part of the invention for predicting results of a simulated superstrate detector system. The measurement cells may be physically partitioned, nonphysically partitioned with software or firmware, or include a combination of different types of partitions. In one embodiment, a plurality of transmission lines are utilized wherein each transmission line includes a plurality of measurement cells. The plurality of transmission lines may be multiplexed with the signal from each transmission line being applied to the same phase detector. In one embodiment, an inverse problem method is applied to determine the superstrate dielectric for a transmission line with multiple measurement cells.

A combinatorial approach to the design of vaccines.

PubMed

Martínez, Luis; Milanič, Martin; Legarreta, Leire; Medvedev, Paul; Malaina, Iker; de la Fuente, Ildefonso M

2015-05-01

We present two new problems of combinatorial optimization and discuss their applications to the computational design of vaccines. In the shortest λ-superstring problem, given a family S1,...,S(k) of strings over a finite alphabet, a set Τ of "target" strings over that alphabet, and an integer λ, the task is to find a string of minimum length containing, for each i, at least λ target strings as substrings of S(i). In the shortest λ-cover superstring problem, given a collection X1,...,X(n) of finite sets of strings over a finite alphabet and an integer λ, the task is to find a string of minimum length containing, for each i, at least λ elements of X(i) as substrings. The two problems are polynomially equivalent, and the shortest λ-cover superstring problem is a common generalization of two well known combinatorial optimization problems, the shortest common superstring problem and the set cover problem. We present two approaches to obtain exact or approximate solutions to the shortest λ-superstring and λ-cover superstring problems: one based on integer programming, and a hill-climbing algorithm. An application is given to the computational design of vaccines and the algorithms are applied to experimental data taken from patients infected by H5N1 and HIV-1.

Tree-level S-matrix of Pohlmeyer reduced form of AdS 5 × S 5 superstring theory

NASA Astrophysics Data System (ADS)

Hoare, B.; Tseytlin, A. A.

2010-02-01

With a motivation to find a 2-d Lorentz-invariant solution of the AdS 5 × S 5 superstring we continue the study of the Pohlmeyer-reduced form of this theory. The reduced theory is constructed from currents of the superstring sigma model and is classically equivalent to it. Its action is that of G/ H = Sp(2, 2) × Sp(4)/[SU(2)]4 gauged WZW model deformed by an integrable potential and coupled to fermions. This theory is UV finite and is conjectured to be related to the superstring theory also at the quantum level. Expanded near the trivial vacuum it has the same elementary excitations (8+8 massive bosonic and fermionic 2-d degrees of freedom) as the AdS 5 × S 5 superstring in the S 5 light-cone gauge or near plane-wave expansion. In contrast to the superstring case, the interaction terms in the reduced action are manifestly 2-d Lorentz invariant. Since the theory is integrable, its S-matrix should be effectively determined by the two-particle scattering. Here we explicitly compute the tree-level two-particle S-matrix for the elementary excitations of the reduced theory. We find that this S-matrix has the same index structure and group factorization properties as the superstring S-matrix computed in hep-th/0611169 but has simpler coefficients, depending only on the difference of two rapidities. While the gauge-fixed form of the reduced action has only the bosonic [SU(2)]4 part of the PSU(2|2) × PSU(2|2) symmetry of the light-cone superstring spectrum as its manifest symmetry we conjecture that it should also have a hidden fermionic symmetry that effectively interchanges bosons and fermions and which should guide us towards understanding the relation between the two S-matrices.

Quantum spectral curve for the η-deformed AdS5 × S5 superstring

NASA Astrophysics Data System (ADS)

Klabbers, Rob; van Tongeren, Stijn J.

2017-12-01

The spectral problem for the AdS5 ×S5 superstring and its dual planar maximally supersymmetric Yang-Mills theory can be efficiently solved through a set of functional equations known as the quantum spectral curve. We discuss how the same concepts apply to the η-deformed AdS5 ×S5 superstring, an integrable deformation of the AdS5 ×S5 superstring with quantum group symmetry. This model can be viewed as a trigonometric version of the AdS5 ×S5 superstring, like the relation between the XXZ and XXX spin chains, or the sausage and the S2 sigma models for instance. We derive the quantum spectral curve for the η-deformed string by reformulating the corresponding ground-state thermodynamic Bethe ansatz equations as an analytic Y system, and map this to an analytic T system which upon suitable gauge fixing leads to a Pμ system - the quantum spectral curve. We then discuss constraints on the asymptotics of this system to single out particular excited states. At the spectral level the η-deformed string and its quantum spectral curve interpolate between the AdS5 ×S5 superstring and a superstring on "mirror" AdS5 ×S5, reflecting a more general relationship between the spectral and thermodynamic data of the η-deformed string. In particular, the spectral problem of the mirror AdS5 ×S5 string, and the thermodynamics of the undeformed AdS5 ×S5 string, are described by a second rational limit of our trigonometric quantum spectral curve, distinct from the regular undeformed limit.

Constraints on cosmic superstrings from Kaluza-Klein emission.

PubMed

Dufaux, Jean-François

2012-07-06

Cosmic superstrings interact generically with a tower of light and/or strongly coupled Kaluza-Klein (KK) modes associated with the geometry of the internal space. We study the production of KK particles by cosmic superstring loops, and show that it is constrained by big bang nucleosynthesis. We study the resulting constraints in the parameter space of the underlying string theory model and highlight their complementarity with the regions that can be probed by current and upcoming gravitational wave experiments.

A L-Band Superstrate Lens Enhanced Antenna and Array for Tactical Operations

DTIC Science & Technology

2013-07-01

unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT The design of a 1.2 GHz microstrip antenna utilizing a superstrate layer for gain enhancement is...CA, 92152-5001 sam.chieh@navy.mil Abstract—The design of a 1.2 GHz microstrip antenna utilizing a superstrate layer for gain enhancement is...realized. The microstrip patch antenna is a widely used antenna in this regime as it is light weight and is easily scalable for increased gains. It has

Quantization of higher abelian gauge theory in generalized differential cohomology

NASA Astrophysics Data System (ADS)

Szabo, R.

We review and elaborate on some aspects of the quantization of certain classes of higher abelian gauge theories using techniques of generalized differential cohomology. Particular emphasis is placed on the examples of generalized Maxwell theory and Cheeger-Simons cohomology, and of Ramond-Ramond fields in Type II superstring theory and differential K-theory.

Observational physics of mirror world

NASA Technical Reports Server (NTRS)

Khlopov, M. YA.; Beskin, G. M.; Bochkarev, N. E.; Pustilnik, L. A.; Pustilnik, S. A.

1989-01-01

The existence of the whole world of shadow particles, interacting with each other and having no mutual interactions with ordinary particles except gravity is a specific feature of modern superstring models, being considered as models of the theory of everything. The presence of shadow particles is the necessary condition in the superstring models, providing compensation of the asymmetry of left and right chirality states of ordinary particles. If compactification of additional dimensions retains the symmetry of left and right states, shadow world turns to be the mirror one, with particles and fields having properties strictly symmetrical to the ones of corresponding ordinary particles and fields. Owing to the strict symmetry of physical laws for ordinary and mirror particles, the analysis of cosmological evolution of mirror matter provides rather definite conclusions on possible effects of mirror particles in the universe. A general qualitative discussion of possible astronomical impact of mirror matter is given, in order to make as wide as possible astronomical observational searches for the effects of mirror world, being the unique way to test the existence of mirror partners of ordinary particles in the Nature.

Infinite tension limit of the pure spinor superstring

NASA Astrophysics Data System (ADS)

Berkovits, Nathan

2014-03-01

Mason and Skinner recently constructed a chiral infinite tension limit of the Ramond-Neveu-Schwarz superstring which was shown to compute the Cachazo-He-Yuan formulae for tree-level d = 10 Yang-Mills amplitudes and the NS-NS sector of tree-level d = 10 supergravity amplitudes. In this letter, their chiral infinite tension limit is generalized to the pure spinor superstring which computes a d = 10 superspace version of the Cachazo-He-Yuan formulae for tree-level d = 10 super-Yang-Mills and supergravity amplitudes.

Fabrication of nanocrystal ink based superstrate-type CuInS₂ thin film solar cells.

PubMed

Cho, Jin Woo; Park, Se Jin; Kim, Woong; Min, Byoung Koun

2012-07-05

A CuInS₂ (CIS) nanocrystal ink was applied to thin film solar cell devices with superstrate-type configuration. Monodispersed CIS nanocrystals were synthesized by a colloidal synthetic route and re-dispersed in toluene to form an ink. A spray method was used to coat CIS films onto conducting glass substrates. Prior to CIS film deposition, TiO₂ and CdS thin films were also prepared as a blocking layer and a buffer layer, respectively. We found that both a TiO₂ blocking layer and a CdS buffer layer are necessary to generate photoresponses in superstrate-type devices. The best power conversion efficiency (∼1.45%) was achieved by the CIS superstrate-type thin film solar cell device with 200 and 100 nm thick TiO₂ and CdS films, respectively.

String-inspired supergravity model at one loop

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaillard, M.K.; Papadopoulos, A.; Pierce, D.M.

1992-03-15

We study a prototype supergravity model from superstrings, with three generations of matter fields in the untwisted sector, nonperturbatively induced supersymmetry breaking and including threshold corrections in conformity with modular invariance. The scale degeneracy of the vacuum is lifted at the one-loop level, allowing a determination of the fundamental parameters of the effective low-energy theory.

SAR reduction using a single SRR superstrate for a dual-band antenna.

PubMed

Rosaline, Imaculate; Singaravelu, Raghavan

2017-01-01

A dual-band microstrip antenna operating at GSM 900 and GSM 1800 MHz is designed initially. Then a single split ring resonator (SRR) structure is used as a superstrate for this dual-band antenna. A circular current is induced in the SRR due to the perpendicular plane wave excitation, which in turn leads to an electric excitation coupled to the magnetic resonance. It also exhibits higher order excitations at 0.9 and 1.8 GHz which ultimately resulted in specific absorption rate (SAR) reduction of human head at both the designed frequencies of the antenna. The antenna and the SRR superstrate are printed on a 1.6 mm thick FR-4 substrate of dimension 59.6 × 49.6 mm 2 . Analysis of the SRR using the classic waveguide theory approach is discussed. Radiation pattern of the antenna in the presence of SRR superstrate and human head is also discussed. Prototype of the antenna along with the SRR superstrate is fabricated and measured for return loss and radiation pattern. Measurement results fairly agree with the simulated results. A human head phantom is utilized in the calculation of SAR.

Yukawa couplings in superstring compactification. [in quantum gravity theory

NASA Technical Reports Server (NTRS)

Strominger, A.

1985-01-01

A topological formula is given for the entire tree-level contribution to the low-energy effective action of a Calabi-Yau superstring compactification. The constraints on proton lifetime in the Calabi-Yau compactification are discussed in detail.

Sv-map between type I and heterotic sigma models

NASA Astrophysics Data System (ADS)

Fan, Wei; Fotopoulos, A.; Stieberger, S.; Taylor, T. R.

2018-05-01

The scattering amplitudes of gauge bosons in heterotic and open superstring theories are related by the single-valued projection which yields heterotic amplitudes by selecting a subset of multiple zeta value coefficients in the α‧ (string tension parameter) expansion of open string amplitudes. In the present work, we argue that this relation holds also at the level of low-energy expansions (or individual Feynman diagrams) of the respective effective actions, by investigating the beta functions of two-dimensional sigma models describing world-sheets of open and heterotic strings. We analyze the sigma model Feynman diagrams generating identical effective action terms in both theories and show that the heterotic coefficients are given by the single-valued projection of the open ones. The single-valued projection appears as a result of summing over all radial orderings of heterotic vertices on the complex plane representing string world-sheet.

Strings, boundary fermions and coincident D-branes

NASA Astrophysics Data System (ADS)

Wulff, Linus

2007-01-01

This thesis describes an attempt to write down covariant actions for coincident D-branes using so-called boundary fermions instead of matrices to describe the non-abelian fields. These fermions can be thought of as Chan-Paton degrees of freedom for the open string. It is shown that by gauge-fixing and by suitably quantizing these boundary fermions the non-abelian action that is known, the Myers action, can be reproduced. Furthermore it is shown that under natural assumptions, unlike the Myers action, the action formulated using boundary fermions also posseses kappa-symmetry when formulated on superspace. Another aspect of string theory discussed in this thesis is that of tensionless strings. These are of great interest for example because of their possible relation to higher spin gauge theories via the AdS/CFT-correspondence. The tensionless superstring in a plane wave background, a Penrose limit of the near-horizon geometry of a stack of D3-branes, is considered and compared to the tensile case.

On the worldsheet theory of the type IIA {text{Ad}}{{text{S}}_4} × mathbb{C}{mathbb{P}_3} superstring

NASA Astrophysics Data System (ADS)

Sundin, Per

2010-04-01

We perform a detailed study of the type IIA superstring in {text{Ad}}{{text{S}}_4} × mathbb{C}{mathbb{P}_3} . After introducing suitable bosonic light-cone and fermionic kappa worldsheet gauges we derive the pure boson and fermion SU(2|2)×U(1) covariant light-cone Hamiltonian up to quartic order in fields. As a first application of our derivation we calculate energy shifts for string configurations in a closed fermionic subsector and successfully match these with a set of light-cone Bethe equations. We then turn to investigate the mismatch between the degrees of freedom of scattering states and oscillatory string modes. Since only light string modes appear as fundamental Bethe roots in the scattering theory, the physical role of the remaining 4 F + 4 B massive oscillators is rather unclear. By continuing a line of research initiated by Zarembo, we shed light on this question by calculating quantum corrections for the propagators of the bosonic massive fields. We show that, once loop corrections are incorporated, the massive coordinates dissolve in a continuum state of two light particles.

Inhomogeneous tensionless superstrings

NASA Astrophysics Data System (ADS)

Bagchi, Arjun; Banerjee, Aritra; Chakrabortty, Shankhadeep; Parekh, Pulastya

2018-02-01

We construct a novel tensionless limit of Superstring theory that realises the Inhomogeneous Super Galilean Conformal Algebra (SGCA I ) as the residual symmetry in the analogue of the conformal gauge, as opposed to previous constructions of the tensionless superstring, where a smaller symmetry algebra called the Homogeneous SGCA emerged as the residual gauge symmetry on the worldsheet. We obtain various features of the new tensionless theory intrinsically as well as from a systematic limit of the corresponding features of the tensile theory. We discuss why it is desirable and also natural to work with this new tensionless limit and the larger algebra.

The decay of highly excited open strings

NASA Technical Reports Server (NTRS)

Mitchell, D.; Turok, N.; Wilkinson, R.; Jetzer, P.

1988-01-01

The decay rates of leading edge Regge trajectory states are calculated for very high level number in open bosonic string theories, ignoring tachyon final states. The optical theorem simplifies the analysis while enabling identification of the different mass level decay channels. The main result is that (in four dimensions) the greatest single channel is the emission of a single photon and a state of the next mass level down. A simple asymptotic formula for arbitrarily high level number is given for this process. Also calculated is the total decay rate exactly up to N=100. It shows little variation over this range but appears to decrease for larger N. The formalism is checked in examples and the decay rate of the first excited level calculated for open superstring theories. The calculation may also have implications for high spin meson resonances.

Extra Dimensions of Space: Are They Going to be Found Soon?

ScienceCinema

Rubakov, Valery [Institute for Nuclear Research, Moscow, Russia

2017-12-09

Our space may well have more than 3 dimensions. Indeed, theories that pretend to be most fundamental choose to live in higher dimensions: a natural area for superstring/Mtheory is 9- or 10-dimensional space. Extra dimensions have been hidden so far, but they would open up above a certain energy threshold. A fascinating possibility is that this happens within reach of particle colliders. This lecture will address the motivation for such a viewpoint and implications of accessible extra dimensions for our understanding of nature.

Brane inflation and cosmic string tension in superstring theory

NASA Astrophysics Data System (ADS)

Firouzjahi, Hassan; Tye, S.-H. Henry

2005-03-01

In a simple reanalysis of the KKLMMT scenario, we argue that the slow roll condition in the D3-overline {D}3 -brane inflationary scenario in superstring theory requires no more than a moderate tuning. The cosmic string tension is very sensitive to the conformal coupling: with less fine-tuning, the cosmic string tension (as well as the ratio of tensor to scalar perturbation mode) increases rapidly and can easily saturate the present observational bound. In a multi-throat brane inflationary scenario, this feature substantially improves the chance of detecting and measuring the properties of the cosmic strings as a window to the superstring theory and our pre-inflationary universe.

Progress report for a research program in theoretical high energy physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feldman, D.; Fried, H.M.; Jevicki, A.

This year's research has dealt with: superstrings in the early universe; the invisible axion emissions from SN1987A; quartic interaction in Witten's superstring field theory; W-boson associated multiplicity and the dual parton model; cosmic strings and galaxy formation; cosmic strings and baryogenesis; quark flavor mixing; p -- /bar p/ scattering at TeV energies; random surfaces; ordered exponentials and differential equations; initial value and back-reaction problems in quantum field theory; string field theory and Weyl invariance; the renormalization group and string field theory; the evolution of scalar fields in an inflationary universe, with and without the effects of gravitational perturbations; cosmic stringmore » catalysis of skyrmion decay; inflation and cosmic strings from dynamical symmetry breaking; the physic of flavor mixing; string-inspired cosmology; strings at high-energy densities and complex temperatures; the problem of non-locality in string theory; string statistical mechanics; large-scale structures with cosmic strings and neutrinos; the delta expansion for stochastic quantization; high-energy neutrino flux from ordinary cosmic strings; a physical picture of loop bremsstrahlung; cylindrically-symmetric solutions of four-dimensional sigma models; large-scale structure with hot dark matter and cosmic strings; the unitarization of the odderon; string thermodynamics and conservation laws; the dependence of inflationary-universe models on initial conditions; the delta expansion and local gauge invariance; particle physics and galaxy formation; chaotic inflation with metric and matter perturbations; grand-unified theories, galaxy formation, and large-scale structure; neutrino clustering in cosmic-string-induced wakes; and infrared approximations to nonlinear differential equations. 17 refs.« less

Better Back Contacts for Solar Cells on Flexible Substrates

NASA Technical Reports Server (NTRS)

Woods, Lawrence M.; Ribelin, Rosine M.

2006-01-01

Improved low-resistance, semitransparent back contacts, and a method of fabricating them, have been developed for solar photovoltaic cells that are made from thin films of I-III-VI2 semiconductor materials on flexible, high-temperatureresistant polyimide substrates or superstrates. The innovative aspect of the present development lies in the extension, to polyimide substrates or superstrates, of a similar prior development of improved low-resistance, semitransparent back contacts for I-III-VI2 solar cells on glass substrates or superstrates. A cell incorporating this innovation can be used either as a stand-alone photovoltaic device or as part of a monolithic stack containing another photovoltaic device that utilizes light of longer wavelengths.

Deriving all p-brane superalgebras via integrability

NASA Astrophysics Data System (ADS)

Grasso, D. T.; McArthur, I. N.

2018-03-01

In previous work we demonstrated that the enlarged super-Poincare algebras which underlie p-brane and D-brane actions in superstring theory can be directly determined based on the integrability of supersymmetry transformations assigned to fields appearing in Wess-Zumino terms. In that work we derived p-brane superalgebras for p = 2 and 3. Here we extend our previous results and give a compact expression for superalgebras for all valid p.

Towards Lagrangian formulations of mixed-symmetry higher spin fields on AdS-space within BFV-BRST formalism

NASA Astrophysics Data System (ADS)

Reshetnyak, A. A.

2010-11-01

The spectrum of superstring theory on the AdS 5 × S 5 Ramond-Ramond background in tensionless limit contains integer and half-integer higher-spin fields subject at most to two-rows Young tableaux Y( s 1, s 2). We review the details of a gauge-invariant Lagrangian description of such massive and massless higher-spin fields in anti-de-Sitter spaces with arbitrary dimensions. The procedure is based on the construction of Verma modules, its oscillator realizations and of a BFV-BRST operator for non-linear algebras encoding unitary irreducible representations of AdS group.

Gödel universes in string theory

NASA Astrophysics Data System (ADS)

Barrow, John D.; Dabrowski, Mariusz P.

1998-11-01

We show that homogeneous Gödel spacetimes need not contain closed timelike curves in low-energy-effective string theories. We find exact solutions for the Gödel metric in string theory for the full O(α') action including both dilaton and axion fields. The results are valid for bosonic, heterotic and super-strings. To first order in the inverse string tension α', these solutions display a simple relation between the angular velocity of the Gödel universe, Ω, and the inverse string tension of the form α'=1/Ω2 in the absence of the axion field. The generalization of this relationship is also found when the axion field is present.

Interaction of moving branes with background massless and tachyon fields in superstring theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rezaei, Z., E-mail: z.rezaei@aut.ac.ir; Kamani, D., E-mail: kamani@aut.ac.ir

2012-02-15

Using the boundary state formalism, we study a moving Dp-brane in a partially compact space-time in the presence of background fields: the Kalb-Ramond field B{sub {mu}{nu}}, a U(1) gauge field A{sub {alpha}}, and the tachyon field. The boundary state enables us to obtain the interaction amplitude of two branes with the above back-ground fields. The branes are parallel or perpendicular to each other. Because of the presence of background fields, compactification of some space-time directions, motion of the branes, and the arbitrariness of the dimensions of the branes, the system is rather general. Due to the tachyon fields and velocitiesmore » of the branes, the behavior of the interaction amplitude reveals obvious differences from the conventional behavior.« less

Quantum and conversion efficiencies optimization of superstrate CIGS thin-films solar cells using In2Se3 buffer layer

NASA Astrophysics Data System (ADS)

Bouchama, Idris; Boudour, Samah; Bouarissa, Nadir; Rouabah, Zahir

2017-10-01

In this present contribution, AMPS-1D device simulator is employed to study the performances of superstrate SLG/TCO/p-Cu(In,Ga)Se2(CIGS)/n-ODC/n-In2Se3/Metal thin film solar cells. The impact of the TCO and Metal work functions on the cell performance has been investigated. The combination of optical transparency and electrical property for TCO front contact layer is found to yield high efficiency. The obtained results show that the TCO work function should be large enough to achieve high conversion efficiency for superstrate CIGS solar cell. Nevertheless, it is desirable for Metal back contact layer to have low work function to prevent the effect of band bending in the n-In2Se3/Metal interface. Several TCOs materials and metals have been tested respectively as a front and back contact layers for superstrate CIGS solar cells. An efficiency of 20.18%, with Voc ≈ 0.71 V, Jsc ≈ 35.36 mA/cm2 and FF ≈ 80.42%, has been achieved with ZnSn2O3-based as TCO front contact layer. In the case of SnO2:F front contact and indium back contact layers, an efficiency of 16.31%, with Voc ≈ 0.64 V, Jsc ≈ 31.4 mA/cm2 and FF ≈ 79.4%, has been obtained. The present results of simulation suggest an improvement of superstrate CIGS solar cells efficiency for feasible fabrication.

Integrability of the Ad{{S}_{5}}\\times {{S}^{5}} superstring and its deformations

NASA Astrophysics Data System (ADS)

van Tongeren, Stijn J.

2014-10-01

This article reviews the application of integrability to the spectral problem of strings on Ad{{S}5}× {{S}5} and its deformations. We begin with a pedagogical introduction to integrable field theories culminating in the description of their finite-volume spectra through the thermodynamic Bethe ansatz (TBA). Next, we apply these ideas to the Ad{{S}5}× {{S}5} string and in later sections discuss how to account for particular integrable deformations. Through the AdS/CFT correspondence this gives an exact description of anomalous scaling dimensions of single trace operators in planar N=4 supersymmetry Yang-Mills theory, its ‘orbifolds’, and β and γ-deformed supersymmetric Yang-Mills theory. We also touch upon some subtleties arising in these deformed theories. Furthermore, we consider complex excited states (bound states) in the su(2) sector and give their TBA description. Finally we discuss the TBA for a quantum deformation of the Ad{{S}5}× {{S}5} superstring S-matrix, with close relations to among others Pohlmeyer reduced string theory, and briefly indicate more recent developments in this area.

Towards generalized mirror symmetry for twisted connected sum G 2 manifolds

NASA Astrophysics Data System (ADS)

Braun, Andreas P.; Del Zotto, Michele

2018-03-01

We revisit our construction of mirror symmetries for compactifications of Type II superstrings on twisted connected sum G 2 manifolds. For a given G 2 manifold, we discuss evidence for the existence of mirror symmetries of two kinds: one is an autoequivalence for a given Type II superstring on a mirror pair of G 2 manifolds, the other is a duality between Type II strings with different chiralities for another pair of mirror manifolds. We clarify the role of the B-field in the construction, and check that the corresponding massless spectra are respected by the generalized mirror maps. We discuss hints towards a homological version based on BPS spectroscopy. We provide several novel examples of smooth, as well as singular, mirror G 2 backgrounds via pairs of dual projecting tops. We test our conjectures against a Joyce orbifold example, where we reproduce, using our geometrical methods, the known mirror maps that arise from the SCFT worldsheet perspective. Along the way, we discuss non-Abelian gauge symmetries, and argue for the generation of the Affleck-Harvey-Witten superpotential in the pure SYM case.

Highly effective action from large N gauge fields

NASA Astrophysics Data System (ADS)

Yang, Hyun Seok

2014-10-01

Recently Schwarz put forward a conjecture that the world-volume action of a probe D3-brane in an AdS5×S5 background of type IIB superstring theory can be reinterpreted as the highly effective action (HEA) of four-dimensional N =4 superconformal field theory on the Coulomb branch. We argue that the HEA can be derived from the noncommutative (NC) field theory representation of the AdS/CFT correspondence and the Seiberg-Witten (SW) map defining a spacetime field redefinition between ordinary and NC gauge fields. It is based only on the well-known facts that the master fields of large N matrices are higher-dimensional NC U(1) gauge fields and the SW map is a local coordinate transformation eliminating U(1) gauge fields known as the Darboux theorem in symplectic geometry.

Democratic Superstring Field Theory and Its Gauge Fixing

NASA Astrophysics Data System (ADS)

Kroyter, M.

This work is my contribution to the proceedings of the conference``SFT2010 -- the third international conference on string field theory and related topics'' and it reflects my talk there, which described the democratic string field theory and its gauge fixing. The democratic string field theory is the only fully RNS string field theory to date. It lives in the large Hilbert space and includes all picture numbers. Picture changing amounts in this formalism to a gauge transformation. We describe the theory and its properties and show that when partially gauge fixed it can be reduced to the modified theory and to the non-polynomial theory. In the latter case we can even include the Ramond sector in the picture-fixed action. We also show that another partial gauge-fixing leads to a new consistent string field theory at picture number -1.

Module/array interface study

NASA Technical Reports Server (NTRS)

1978-01-01

Several aspects of module design are evaluated, including glass superstrate and metal substrate module configurations, the potential for hail damage, light absorption in glass superstrates, the economics of glass selection, and electrical design. Also, three alternate glass superstrate module configurations are evaluated by means of finite element computer analyses. Two panel sizes, 1.2 by 2.4 m (4 by 8 ft) and 2.4 by 4.8 m are used to support three module sizes, 0.6 by 1.2 m, 1.2 by 1.2 m, and 1.2 by 2.4 m, for design loadings of + or - 1.7 kPa, + or - 2.4 kPa, and + or - 3.6 kPa. Designs and cost estimates are presented for twenty panel types and nine array configurations at each of the three design loadings. Structural cost sensitivities of combined array configurations and panel cases are presented.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pern, F.J.; Glick, S.H.; Czanderna, A.W.

The stabilization effects of various superstrate materials against UV-induced EVA discoloration and the effect of photocurrent enhancement by white light-reflecting substrates are summarized. Based on the results, some alternative PV module encapsulation schemes are proposed for improved module performance, where the current or modified formulations of EVA encapsulants still can be used so that the typical processing tools and conditions need not to be changed significantly. The schemes are designed in an attempt to eliminate or minimize the EVA yellow-browning and to increase the module power output. Four key experimental results from the studies of EVA discoloration and encapsulation aremore » to employ: (1) UV-absorbing (filtering) glasses as superstrates to protect EVA from UV-induced discoloration, (2) gas-permeable polymer films as superstrates and/or substrates to prevent EVA yellowing by permitting photobleaching reactions, (3) modified EVA formulations, and (4) internal reflection of the light by white substrates. {copyright} {ital 1996 American Institute of Physics.}« less

Super-Lie n-algebra extensions, higher WZW models and super-p-branes with tensor multiplet fields

NASA Astrophysics Data System (ADS)

Fiorenza, Domenico; Sati, Hisham; Schreiber, Urs

2015-12-01

We formalize higher-dimensional and higher gauge WZW-type sigma-model local prequantum field theory, and discuss its rationalized/perturbative description in (super-)Lie n-algebra homotopy theory (the true home of the "FDA"-language used in the supergravity literature). We show generally how the intersection laws for such higher WZW-type σ-model branes (open brane ending on background brane) are encoded precisely in (super-)L∞-extension theory and how the resulting "extended (super-)space-times" formalize spacetimes containing σ-model brane condensates. As an application we prove in Lie n-algebra homotopy theory that the complete super-p-brane spectrum of superstring/M-theory is realized this way, including the pure σ-model branes (the "old brane scan") but also the branes with tensor multiplet worldvolume fields, notably the D-branes and the M5-brane. For instance the degree-0 piece of the higher symmetry algebra of 11-dimensional (11D) spacetime with an M2-brane condensate turns out to be the "M-theory super-Lie algebra". We also observe that in this formulation there is a simple formal proof of the fact that type IIA spacetime with a D0-brane condensate is the 11D sugra/M-theory spacetime, and of (prequantum) S-duality for type IIB string theory. Finally we give the non-perturbative description of all this by higher WZW-type σ-models on higher super-orbispaces with higher WZW terms in stacky differential cohomology.

Supersymmetric string waves

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bergshoeff, E.A.; Kallosh, R.; Ortin, T.

1993-06-15

We present plane-wave-type solutions of the lowest-order superstring effective action which have unbroken space-time supersymmetries. They are given by a stringy generalization of the Brinkmann metric, dialton, axion, and gauge fields. Some conspiracy between the metric and the axion field is required. The [alpha][prime] stringy corrections to the effective on-shell action, to the equations of motion (and therefore to the solutions themselves), and to the supersymmetry transformations are shown to vanish for a special class of these solutions that we call supersymmetric string waves (SSW's). In the SSW solutions, there exists a conspiracy not only between the metric and themore » axion field, but also between the gauge fields and the metric, since the embedding of the spin connection in the gauge group is required.« less

Thermoelectric generator and method for the fabrication thereof

DOEpatents

Benson, David K.; Tracy, C. Edwin

1987-01-01

A thermoelectric generator using semiconductor elements for responding to a temperature gradient to produce electrical energy with all of the semiconductor elements being of the same type is disclosed. A continuous process for forming substrates on which the semiconductor elements and superstrates are deposited and a process for forming the semiconductor elements on the substrates are also disclosed. The substrates with the semiconductor elements thereon are combined with superstrates to form modules for use thermoelectric generators.

Thermoelectric generator and method for the fabrication thereof

DOEpatents

Benson, D.K.; Tracy, C.E.

1984-08-01

A thermoelectric generator using semiconductor elements for responding to a temperature gradient to produce electrical energy with all of the semiconductor elements being of the same type is disclosed. A continuous process for forming substrates on which the semiconductor elements and superstrates are deposited and a process for forming the semiconductor elements on the substrates are also disclosed. The substrates with the semiconductor elements thereon are combined with superstrates to form modules for use as thermoelectric generators.

Amorphous oxides as electron transport layers in Cu(In,Ga)Se 2 superstrate devices: Amorphous oxides in Cu(In,Ga)Se 2 superstrate devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heinemann, M. D.; van Hest, M. F. A. M.; Contreras, M.

Cu(In,Ga)Se2 (CIGS) solar cells in superstrate configuration promise improved light management and higher stability compared to substrate devices, but they have yet to deliver comparable power conversion efficiencies (PCEs). Chemical reactions between the CIGS layer and the front contact were shown in the past to deteriorate the p-n junction in superstrate devices, which led to lower efficiencies compared to the substrate-type devices. This work aims to solve this problem by identifying a buffer layer between the CIGS layer and the front contact, acting as the electron transport layer, with an optimized electron affinity, doping density and chemical stability. Using combinatorialmore » material exploration we identified amorphous gallium oxide (a-GaOx) as a potentially suitable buffer layer material. The best results were obtained for a-GaOx with an electron affinity that was found to be comparable to that of CIGS. Based on the results of device simulations, it is assumed that detrimental interfacial acceptor states are present at the interface between CIGS and a-GaOx. However, these initial experiments indicate the potential of a-GaOx in this application, and how to reach performance parity with substrate devices, by further increase of its n-type doping density.« less

The Big Bang, Superstring Theory and the origin of life on the Earth.

PubMed

Trevors, J T

2006-03-01

This article examines the origin of life on Earth and its connection to the Superstring Theory, that attempts to explain all phenomena in the universe (Theory of Everything) and unify the four known forces and relativity and quantum theory. The four forces of gravity, electro-magnetism, strong and weak nuclear were all present and necessary for the origin of life on the Earth. It was the separation of the unified force into four singular forces that allowed the origin of life.

Cosmic superstrings: Observable remnants of brane inflation

NASA Astrophysics Data System (ADS)

Wyman, Mark Charles

Brane inflation provides a natural dynamical model for the physics which underlie the inflationary paradigm. Besides their inflationary predictions, brane models imply another observable consequence: cosmic strings. In this dissertation I outline the background of how cosmic strings arise in brane inflationary models and how the properties of the strings and the models are mutually tied (Chapter 2). I then use cosmological observations to put limits on the properties of any actually-existing cosmic string network (Chapter 3). Next, I study the question of how cosmic superstrings, as the cosmic strings arising from string theory are known, could be distinct from classical gauge- theory cosmic strings. In particular, I propose an analytical model for the cosmological evolution of a network of binding cosmic strings (Chapter 4); I also describe the distinctive gravitational lensing phenomena that are caused by binding strings (Chapter 5). Finally, I lay out the background for the numerical study of a gauge theory model for the dynamics of cosmic superstring binding (Chapter 6).

A Module Experimental Process System Development Unit (MEPSDU)

NASA Technical Reports Server (NTRS)

1981-01-01

Design work for a photovoltaic module, fabricated using single crystal silicon dendritic web sheet material, resulted in the identification of surface treatment to the module glass superstrate which improved module efficiencies. A final solar module environmental test, a simulated hailstone impact test, was conducted on full size module superstrates to verify that the module's tempered glass superstrate can withstand specified hailstone impacts near the corners and edges of the module. Process sequence design work on the metallization process selective, liquid dopant investigation, dry processing, and antireflective/photoresist application technique tasks, and optimum thickness for Ti/Pd are discussed. A noncontact cleaning method for raw web cleaning was identified and antireflective and photoresist coatings for the dendritic webs were selected. The design of a cell string conveyor, an interconnect feed system, rolling ultrasonic spot bonding heat, and the identification of the optimal commercially available programmable control system are also discussed. An economic analysis to assess cost goals of the process sequence is also given.

Critical non-Abelian vortex in four dimensions and little string theory

NASA Astrophysics Data System (ADS)

Shifman, M.; Yung, A.

2017-08-01

As was shown recently, non-Abelian vortex strings supported in four-dimensional N =2 supersymmetric QCD with the U(2) gauge group and Nf=4 quark multiplets (flavors) become critical superstrings. In addition to the translational moduli, non-Abelian strings under consideration carry six orientational and size moduli. Together, they form a ten-dimensional target space required for a superstring to be critical. The target space of the string sigma model is a product of the flat four-dimensional space and a Calabi-Yau noncompact threefold, namely, the conifold. We study closed string states which emerge in four dimensions and identify them with hadrons of four-dimensional N =2 QCD. One massless state was found previously; it emerges as a massless hypermultiplet associated with the deformation of the complex structure of the conifold. In this paper, we find a number of massive states. To this end, we exploit the approach used in LST little string theory, namely, the equivalence between the critical string on the conifold and noncritical c =1 string with the Liouville field and a compact scalar at the self-dual radius. The states we find carry "baryonic" charge (its definition differs from standard). We interpret them as "monopole necklaces" formed (at strong coupling) by the closed string with confined monopoles attached.

Physics of the very early Universe: what can we learn from cosmological observations?

NASA Astrophysics Data System (ADS)

Gondolo, Paolo

Cosmological observations are starting to probe the evolution of the Universe before nucleosyn- thesis. The observed fluctuations in the cosmic microwave background and in the distribution of matter can be traced back to their origin during inflation, and the inflaton potential has begun to be unraveled. A future probe of the first microseconds would be the detection of weakly-interacting massive particles as dark matter. Discovery of supersymmetric particles at odds with the standard cosmological lore may open an experimental window on the physics at the highest energies, per- haps as far as superstring theory. This presentation will overview two topics on the physics of the Universe before nucleosynthesis: (1) slow-roll, natural and chain inflation in the landscape, and

Computing the scalar field couplings in 6D supergravity

NASA Astrophysics Data System (ADS)

Saidi, El Hassan

2008-11-01

Using non-chiral supersymmetry in 6D space-time, we compute the explicit expression of the metric the scalar manifold SO(1,1)×{SO(4,20)}/{SO(4)×SO(20)} of the ten-dimensional type IIA superstring on generic K3. We consider as well the scalar field self-couplings in the general case where the non-chiral 6D supergravity multiplet is coupled to generic n vector supermultiplets with moduli space SO(1,1)×{SO(4,n)}/{SO(4)×SO(n)}. We also work out a dictionary giving a correspondence between hyper-Kähler geometry and the Kähler geometry of the Coulomb branch of 10D type IIA on Calabi-Yau threefolds. Others features are also discussed.

No-Ghost Theorem for Neveu-Schwarz String in 0-Picture

NASA Astrophysics Data System (ADS)

Kohriki, M.; Kunitomo, H.; Murata, M.

2010-12-01

The no-ghost theorem for Neveu-Schwarz string is directly proved in 0-picture. The one-to-one correspondence between physical states in 0-picture and in the conventional (-1)-picture is confirmed. It is shown that a nontrivial metric consistent with the BRST cohomology is needed to define a positive semidefinite norm in the physical Hilbert space. As a by-product, we find a new inverse picture-changing operator, which is noncovariant but has a nonsingular operator product with itself. A possibility to construct a new gauge-invariant superstring field theory is discussed.

The Birth of String Theory

NASA Astrophysics Data System (ADS)

Cappelli, Andrea; Castellani, Elena; Colomo, Filippo; Di Vecchia, Paolo

2012-04-01

Part I. Overview: 1. Introduction and synopsis; 2. Rise and fall of the hadronic string G. Veneziano; 3. Gravity, unification, and the superstring J. H. Schwarz; 4. Early string theory as a challenging case study for philosophers E. Castellani; Part II. The Prehistory: The Analytic S-Matrix: 5. Introduction to Part II; 6. Particle theory in the sixties: from current algebra to the Veneziano amplitude M. Ademollo; 7. The path to the Veneziano model H. R. Rubinstein; 8. Two-component duality and strings P. G. O. Freund; 9. Note on the prehistory of string theory M. Gell-Mann; Part III. The Dual Resonance Model: 10. Introduction to Part III; 11. From the S-matrix to string theory P. Di Vecchia; 12. Reminiscence on the birth of string theory J. A. Shapiro; 13. Personal recollections D. Amati; 14. Early string theory at Fermilab and Rutgers L. Clavelli; 15. Dual amplitudes in higher dimensions: a personal view C. Lovelace; 16. Personal recollections on dual models R. Musto; 17. Remembering the 'supergroup' collaboration F. Nicodemi; 18. The '3-Reggeon vertex' S. Sciuto; Part IV. The String: 19. Introduction to Part IV; 20. From dual models to relativistic strings P. Goddard; 21. The first string theory: personal recollections L. Susskind; 22. The string picture of the Veneziano model H. B. Nielsen; 23. From the S-matrix to string theory Y. Nambu; 24. The analogue model for string amplitudes D. B. Fairlie; 25. Factorization in dual models and functional integration in string theory S. Mandelstam; 26. The hadronic origins of string theory R. C. Brower; Part V. Beyond the Bosonic String: 27. Introduction to Part V; 28. From dual fermion to superstring D. I. Olive; 29. Dual models with fermions: memoirs of an early string theorist P. Ramond; 30. Personal recollections A. Neveu; 31. Aspects of fermionic dual models E. Corrigan; 32. The dual quark models K. Bardakci and M. B. Halpern; 33. Remembering the dawn of relativistic strings J.-L. Gervais; 34. Early string theory in Cambridge: personal recollections C. Montonen; Part VI. The Superstring: 35. Introduction to Part VI; 36. Supersymmetry in string theory F. Gliozzi; 37. Gravity from strings: personal reminiscences of early developments T. Yoneya; 38. From the Nambu-Goto to the σ-model action L. Brink; 39. Locally supersymmetric action for superstring P. Di Vecchia; 40. Personal recollections E. Cremmer; 41. The scientific contributions of Joël Scherk J. H. Schwarz; Part VII. Preparing the String Renaissance: 42. Introduction to Part VII; 43. From strings to superstrings: a personal perspective M. B. Green; 44. Quarks, strings and beyond A. M. Polyakov; 45. The rise of the superstring theory A. Cappelli and F. Colomo; Appendices; Index.

SUSY’s Ladder: Reframing sequestering at Large Volume

DOE PAGES

Reece, Matthew; Xue, Wei

2016-04-07

Theories with approximate no-scale structure, such as the Large Volume Scenario, have a distinctive hierarchy of multiple mass scales in between TeV gaugino masses and the Planck scale, which we call SUSY's Ladder. This is a particular realization of Split Supersymmetry in which the same small parameter suppresses gaugino masses relative to scalar soft masses, scalar soft masses relative to the gravitino mass, and the UV cutoff or string scale relative to the Planck scale. This scenario has many phenomenologically interesting properties, and can avoid dangers including the gravitino problem, flavor problems, and the moduli-induced LSP problem that plague othermore » supersymmetric theories. We study SUSY's Ladder using a superspace formalism that makes the mysterious cancelations in previous computations manifest. This opens the possibility of a consistent effective field theory understanding of the phenomenology of these scenarios, based on power-counting in the small ratio of string to Planck scales. We also show that four-dimensional theories with approximate no-scale structure enforced by a single volume modulus arise only from two special higher-dimensional theories: five-dimensional supergravity and ten-dimensional type IIB supergravity. As a result, this gives a phenomenological argument in favor of ten dimensional ultraviolet physics which is different from standard arguments based on the consistency of superstring theory.« less

Semi-abelian Z-theory: NLSM+ ϕ 3 from the open string

NASA Astrophysics Data System (ADS)

Carrasco, John Joseph M.; Mafra, Carlos R.; Schlotterer, Oliver

2017-08-01

We continue our investigation of Z-theory, the second double-copy component of open-string tree-level interactions besides super-Yang-Mills (sYM). We show that the amplitudes of the extended non-linear sigma model (NLSM) recently considered by Cachazo, Cha, and Mizera are reproduced by the leading α '-order of Z-theory amplitudes in the semi-abelian case. The extension refers to a coupling of NLSM pions to bi-adjoint scalars, and the semi-abelian case involves to a partial symmetrization over one of the color orderings that characterize the Z-theory amplitudes. Alternatively, the partial symmetrization corresponds to a mixed interaction among abelian and non-abelian states in the underlying open-superstring amplitude. We simplify these permutation sums via monodromy relations which greatly increase the efficiency in extracting the α '-expansion of these amplitudes. Their α '-corrections encode higher-derivative interactions between NLSM pions and bi-colored scalars all of which obey the duality between color and kinematics. Through double-copy, these results can be used to generate the predictions of supersymmetric Dirac-Born-Infeld-Volkov-Akulov theory coupled with sYM as well as a complete tower of higher-order α '-corrections.

The zero-action hypothesis and high-temperature thermodynamics in the heterotic superstring theory

NASA Astrophysics Data System (ADS)

Pollock, M. D.

2005-07-01

The effective action S for the Einstein theory of gravity coupled to massless scalar fields phi, spinor fields ψ and gauge vector fields Fij describing radiation, so that FijFij = 0, vanishes identically after substitution from the classical equations of motion, thus allowing a perfect fluid for which the energy density ρ and pressure p = (γ - 1)ρ are related by values of the adiabatic index throughout the range 4/3 <= γ <= 2. In the heterotic superstring theory, four-point gravitational interactions generate a tree-level quadratic, higher-derivative contribution to the Lagrangian, after reduction to four dimensions, whose form, unchanged at one-loop level, is {\\cal R}^2 = B(R^2 -R_{ij}R^{ij}) = {1 \\over 6} B (\\gamma-2)(\\gamma-1) \\kappa^4 \\rho^2 , where the constant B ap 1 for a three-generation Calabi Yau manifold, and which thus constitutes a type of anomaly. The zero-action hypothesis requires the theory to be free of such anomalies, and thus predicts that the Universe started off in the state p = ρ discussed by Zel'dovich, characterized by the maximum value γ = 2 consistent with causality. Applying classical thermodynamics to a perfect fluid, we find that ρ, p and hence also the Helmholtz free-energy density f ≡ -p, scale with temperature as Tγ/γ-1, leading to the prediction that f ~ T2, which is exactly verified by the calculation of Atick and Witten, valid at genus-one in the high-temperature limit T Gt TH, after Euclideanizing the time coordinate, where TH is the Hagedorn temperature. The response of the action to the operators T, C and P is also discussed, T-invariance requiring γ = 2 and hence S = 0, and P-invariance requiring S = 0, showing that the zero-action hypothesis can be understood in terms of these discrete symmetries.

On non-BPS effective actions of string theory

NASA Astrophysics Data System (ADS)

Hatefi, Ehsan

2018-05-01

We discuss some physical prospective of the non-BPS effective actions of type IIA and IIB superstring theories. By dealing with all complete three and four point functions, including a closed Ramond-Ramond string (in terms of both its field strength and its potential), gauge (scalar) fields as well as a real tachyon and under symmetry structures, we find various restricted world volume and bulk Bianchi identities. The complete forms of the non-BPS scattering amplitudes including their Chan-Paton factors are elaborated. All the singularity structures of the non-BPS amplitudes, their all order α ' higher-derivative corrections, their contact terms and various modified Bianchi identities are derived. Finally, we show that scattering amplitudes computed in different super-ghost pictures are compatible when suitable Bianchi identities are imposed on the Ramond-Ramond fields. Moreover, we argue that the higher-derivative expansion in powers of the momenta of the tachyon is universal.

Scaling properties of cosmic (super)string networks

NASA Astrophysics Data System (ADS)

Martins, C. J. A. P.

2014-10-01

I use a combination of state-of-the-art numerical simulations and analytic modelling to discuss the scaling properties of cosmic defect networks, including superstrings. Particular attention is given to the role of extra degrees of freedom in the evolution of these networks. Compared to the 'plain vanilla' case of Goto-Nambu strings, three such extensions play important but distinct roles in the network dynamics: the presence of charges/currents on the string worldsheet, the existence of junctions, and the possibility of a hierarchy of string tensions. I also comment on insights gained from studying simpler defect networks, including Goto-Nambu strings themselves, domain walls and semilocal strings.

Apollo(R) Thin Film Process Development: Final Technical Report, April 1998 - April 2002

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cunningham, D.W.

2002-10-01

BP Solar first started investigative work on CdTe photovoltaics in 1986. The module product name chosen for the CdTe devices is Apollo. The deposition method chosen was electrochemical deposition due to its simplicity and good control of stoichiometric composition. The window layer used is CdS, produced from a chemical-bath deposition. Initial work focused on increasing photovoltaic cell size from a few mm2 to 900 cm2. At BP Solar's Fairfield plant, work is focused on increasing semiconductor deposition to 1 m2. The primary objective of this subcontract is to establish the conditions required for the efficient plating of CdS/CdTe on large-area,more » transparent conducting tin-oxide-coated glass superstrate. The initial phase concentrates on superstrate sizes up to 0.55 m2. Later phases will include work on 0.94 m2 superstrates. The tasks in this subcontract have been split into four main categories: (1) CdS and CdTe film studies; (2) Enhanced laser processing; (3) Outdoor testing program for the Apollo module; and (4) Production waste abatement and closed loop study.« less

On the elliptic genera of manifolds of Spin(7) holonomy

DOE PAGES

Benjamin, Nathan; Harrison, Sarah M.; Kachru, Shamit; ...

2015-12-16

Superstring compactification on a manifold of Spin(7) holonomy gives rise to a 2d worldsheet conformal field theory with an extended supersymmetry algebra. The N=1 superconformal algebra is extended by additional generators of spins 2 and 5/2, and instead of just superconformal symmetry one has a c = 12 realization of the symmetry group SW(3/2,2). In this paper, we compute the characters of this supergroup and decompose the elliptic genus of a general Spin(7) compactification in terms of these characters. Here, we find suggestive relations to various sporadic groups, which are made more precise in a companion paper.

Numerical investigation of refractometric sensor elements based on side polished fibres using the Galerkin method

NASA Astrophysics Data System (ADS)

Karakoleva, E. I.; Andreev, A. Tz; Zafirova, B. S.

2006-12-01

The Galerkin method was applied to solve the vector wave equation in order to determine the propagation constants and the transverse electric fields of the modes propagating along side polished single-mode and two-mode optical fibres. The effective refractive indices of the modes were calculated depending on the values of the residual cladding (minimum distance between a fibre core and a polished surface) and the superstrate refractive index. The influence of the fibre parameters and working wavelength on the refractometric sensitivity was estimated in the case when a side polished fibre with inscribed in-fibre Bragg grating is used as a sensor element.

Quark soup al dente: applied superstring theory

NASA Astrophysics Data System (ADS)

Myers, R. C.; Vázquez, S. E.

2008-06-01

In recent years, experiments have discovered an exotic new state of matter known as the strongly coupled quark gluon plasma (sQGP). At present, it seems that standard theoretical tools, such as perturbation theory and lattice gauge theory, are poorly suited to understand this new phase. However, recent progress in superstring theory has provided us with a theoretical laboratory for studying very similar systems of strongly interacting hot non-Abelian plasmas. This surprising new perspective extracts the fluid properties of the sQGP from physical processes in a black hole spacetime. Hence we may find the answers to difficult particle physics questions about the sQGP from straightforward calculations in classical general relativity.

Electromagnetic characterization of conformal antennas

NASA Technical Reports Server (NTRS)

Volakis, John L.; Kempel, Leo C.; Alexanian, Angelos; Jin, J. M.; Yu, C. L.; Woo, Alex C.

1992-01-01

The ultimate objective of this project is to develop a new technique which permits an accurate simulation of microstrip patch antennas or arrays with various feed, superstrate and/or substrate configurations residing in a recessed cavity whose aperture is planar, cylindrical or otherwise conformed to the substructure. The technique combines the finite element and boundary integral methods to formulate a system suitable for solution via the conjugate gradient method in conjunction with the fast Fourier transform. The final code is intended to compute both scattering and radiation patterns of the structure with an affordable memory demand. With upgraded capabilities, the four included papers examined the radar cross section (RCS), input impedance, gain, and resonant frequency of several rectangular configurations using different loading and substrate/superstrate configurations.

Nondecoupling of maximal supergravity from the superstring.

PubMed

Green, Michael B; Ooguri, Hirosi; Schwarz, John H

2007-07-27

We consider the conditions necessary for obtaining perturbative maximal supergravity in d dimensions as a decoupling limit of type II superstring theory compactified on a (10-d) torus. For dimensions d=2 and d=3, it is possible to define a limit in which the only finite-mass states are the 256 massless states of maximal supergravity. However, in dimensions d>or=4, there are infinite towers of additional massless and finite-mass states. These correspond to Kaluza-Klein charges, wound strings, Kaluza-Klein monopoles, or branes wrapping around cycles of the toroidal extra dimensions. We conclude that perturbative supergravity cannot be decoupled from string theory in dimensions>or=4. In particular, we conjecture that pure N=8 supergravity in four dimensions is in the Swampland.

Expanding (3+1)-dimensional universe from a lorentzian matrix model for superstring theory in (9+1) dimensions.

PubMed

Kim, Sang-Woo; Nishimura, Jun; Tsuchiya, Asato

2012-01-06

We reconsider the matrix model formulation of type IIB superstring theory in (9+1)-dimensional space-time. Unlike the previous works in which the Wick rotation was used to make the model well defined, we regularize the Lorentzian model by introducing infrared cutoffs in both the spatial and temporal directions. Monte Carlo studies reveal that the two cutoffs can be removed in the large-N limit and that the theory thus obtained has no parameters other than one scale parameter. Moreover, we find that three out of nine spatial directions start to expand at some "critical time," after which the space has SO(3) symmetry instead of SO(9).

The next generation CdTe technology- Substrate foil based solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferekides, Chris

The main objective of this project was the development of one of the most promising Photovoltaic (PV) materials CdTe into a versatile, cost effective, and high throughput technology, by demonstrating substrate devices on foil substrates using high throughput fabrication conditions. The typical CdTe cell is of the superstrate configuration where the solar cell is fabricated on a glass superstrate by the sequential deposition of a TCO, n-type heterojunction partner, p-CdTe absorber, and back contact. Large glass modules are heavy and present significant challenges during manufacturing (uniform heating, etc.). If a substrate CdTe cell could be developed (the main goal ofmore » this project) a roll-to-toll high throughput technology could be developed.« less

Supersymmetry, Supergravity, and Unification

NASA Astrophysics Data System (ADS)

Nath, Pran

2016-12-01

Dedication; Preface; 1. A brief history of unification; 2. Gravitation; 3. Non-abelian gauge theory; 4. Spontaneous breaking of global and local symmetries; 5. The Standard Model; 6. Anomalies; 7. Effective Lagrangians; 8. Supersymmetry; 9. Grand unification; 10. MSSM Lagrangian; 11. N = 1 supergravity; 12. Coupling of supergravity with matter and gauge fields; 13. Supergravity grand unification; 14. Phenomenology of supergravity grand unification; 15. CP violation in supergravity unified theories; 16. Proton stability in supergravity unified theories; 17. Cosmology, astroparticle physics and SUGRA unification; 18. Extended supergravities and supergravities from superstrings; 19. Specialized topics; 20. The future of unification; 21. Appendices; 22. Notations, conventions, and formulae; 23. Physical constants; 24. List of books and reviews for further reading; Index.

Comparative Study of 28 and 18 Years Field Aged Siemens-Arco M55 Modules in Temperate and Hot-Dry Climates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chicca, Matthew; Wohlgemuth, John; TamizhMani, GovindaSamy

The primary objective of this research work is two-fold: (i) determine the degradation rates of Siemens-Arco M55 modules exposed over 18 and 28 years in a hot-dry climate of Arizona and a temperate climate of California, and; (ii) identify the potential modes responsible for these degradation losses. The degradation rates were determined based on the I-V data obtained on exposed modules and on the corresponding control modules which were not exposed in the fields. The degradation modes responsible for these degradations were determined using several nondestructive tests and destructive tests performed on these control and exposed modules. The nondestructive testsmore » included: current-voltage, visual inspection, cell-module quantum efficiency, and module level reflectance spectroscopy. The destructive tests included: transmittance spectroscopy of glass superstrates, and FTIR, DSC and TGA of encapsulant materials.« less

Buried nanoantenna arrays: versatile antireflection coating.

PubMed

Kabiri, Ali; Girgis, Emad; Capasso, Federico

2013-01-01

Reflection is usually a detrimental phenomenon in many applications such as flat-panel-displays, solar cells, photodetectors, infrared sensors, and lenses. Thus far, to control and suppress the reflection from a substrate, numerous techniques including dielectric interference coatings, surface texturing, adiabatic index matching, and scattering from plasmonic nanoparticles have been investigated. A new technique is demonstrated to manage and suppress reflection from lossless and lossy substrates. It provides a wider flexibility in design versus previous methods. Reflection from a surface can be suppressed over a narrowband, wideband, or multiband frequency range. The antireflection can be dependent or independent of the incident wave polarization. Moreover, antireflection at a very wide incidence angle can be attained. The reflection from a substrate is controlled by a buried nanoantenna array, a structure composed of (1) a subwavelength metallic array and (2) a dielectric cover layer referred to as a superstrate. The material properties and thickness of the superstrate and nanoantennas' geometry and periodicity control the phase and intensity of the wave circulating inside the superstrate cavity. A minimum reflectance of 0.02% is achieved in various experiments in the mid-infrared from a silicon substrate. The design can be integrated in straightforward way in optical devices. The proposed structure is a versatile AR coating to optically impedance matches any substrate to free space in selected any narrow and broadband spectral response across the entire visible and infrared spectrum.

Large field inflation from axion mixing

NASA Astrophysics Data System (ADS)

Shiu, Gary; Staessens, Wieland; Ye, Fang

2015-06-01

We study the general multi-axion systems, focusing on the possibility of large field inflation driven by axions. We find that through axion mixing from a non-diagonal metric on the moduli space and/or from Stückelberg coupling to a U(1) gauge field, an effectively super-Planckian decay constant can be generated without the need of "alignment" in the axion decay constants. We also investigate the consistency conditions related to the gauge symmetries in the multi-axion systems, such as vanishing gauge anomalies and the potential presence of generalized Chern-Simons terms. Our scenario applies generally to field theory models whose axion periodicities are intrinsically sub-Planckian, but it is most naturally realized in string theory. The types of axion mixings invoked in our scenario appear quite commonly in D-brane models, and we present its implementation in type II superstring theory. Explicit stringy models exhibiting all the characteristics of our ideas are constructed within the frameworks of Type IIA intersecting D6-brane models on and Type IIB intersecting D7-brane models on Swiss-Cheese Calabi-Yau orientifolds.

Thin film module development

NASA Technical Reports Server (NTRS)

Jester, T.

1985-01-01

The design of ARCO Solar, Inc.'s Genesis G100 photovoltaic module was driven by several criteria, including environmental stability (both electrical and mechanical), consumer aesthetics, low materials costs, and manufacturing ease. The module circuitry is designed as a 12 volt battery charger, using monolithic patterning techniques on a glass superstrate. This patterning and interconnect method proves amenable to high volume, low cost production throughput, and the use of glass serves the dual role of handling ease and availability. The mechanical design of the module centers on environmental stability. Packaging of the glass superstrate circuit must provide good resistance to thermal and humidity exposure along with hi-pot insulation and hailstone impact resistance. The options considered are given. Ethylene vinyl acetate (EVA) is chosen as the pottant material for its excellent weatherability.

Threshold Effects Beyond the Standard Model

NASA Astrophysics Data System (ADS)

Taylor, T. R.

In this contribution to the Festschrift celebrating Gabriele Veneziano on his 65th birthday, I discuss the threshold effects of extra dimensions and their applications to physics beyond the standard model, focusing on superstring theory.

DIS off glueballs from string theory: the role of the chiral anomaly and the Chern-Simons term

NASA Astrophysics Data System (ADS)

Kovensky, Nicolas; Michalski, Gustavo; Schvellinger, Martin

2018-04-01

We calculate the structure function F 3( x, q 2) of the hadronic tensor of deep inelastic scattering (DIS) of charged leptons from glueballs of N=4 SYM theory at strong coupling and at small values of the Bjorken parameter in the gauge/string theory duality framework. This is done in terms of type IIB superstring theory scattering amplitudes. From the AdS5 perspective, the relevant part of the scattering amplitude comes from the five-dimensional non-Abelian Chern-Simons terms in the SU(4) gauged supergravity obtained from dimensional reduction on S 5. From type IIB superstring theory we derive an effective Lagrangian describing the four-point interaction in the local approximation. The exponentially small regime of the Bjorken parameter is investigated using Pomeron techniques.

Vector curvaton with varying kinetic function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dimopoulos, Konstantinos; Karciauskas, Mindaugas; Wagstaff, Jacques M.

2010-01-15

A new model realization of the vector curvaton paradigm is presented and analyzed. The model consists of a single massive Abelian vector field, with a Maxwell-type kinetic term. By assuming that the kinetic function and the mass of the vector field are appropriately varying during inflation, it is shown that a scale-invariant spectrum of superhorizon perturbations can be generated. These perturbations can contribute to the curvature perturbation of the Universe. If the vector field remains light at the end of inflation it is found that it can generate substantial statistical anisotropy in the spectrum and bispectrum of the curvature perturbation.more » In this case the non-Gaussianity in the curvature perturbation is predominantly anisotropic, which will be a testable prediction in the near future. If, on the other hand, the vector field is heavy at the end of inflation then it is demonstrated that particle production is approximately isotropic and the vector field alone can give rise to the curvature perturbation, without directly involving any fundamental scalar field. The parameter space for both possibilities is shown to be substantial. Finally, toy models are presented which show that the desired variation of the mass and kinetic function of the vector field can be realistically obtained, without unnatural tunings, in the context of supergravity or superstrings.« less

Effective theories and thresholds in particle physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaillard, M.K.

1991-06-07

The role of effective theories in probing a more fundamental underlying theory and in indicating new physics thresholds is discussed, with examples from the standard model and more speculative applications to superstring theory. 38 refs.

On pp wave limit for η deformed superstrings

NASA Astrophysics Data System (ADS)

Roychowdhury, Dibakar

2018-05-01

In this paper, based on the notion of plane wave string/gauge theory duality, we explore the pp wave limit associated with the bosonic sector of η deformed superstrings propagating in ( AdS 5 × S 5) η . Our analysis reveals that in the presence of NS-NS and RR fluxes, the pp wave limit associated to full ABF background satisfies type IIB equations in its standard form. However, the beta functions as well as the string Hamiltonian start receiving non trivial curvature corrections as one starts probing beyond pp wave limit which thereby takes solutions away from the standard type IIB form. Furthermore, using uniform gauge, we also explore the BMN dynamics associated with short strings and compute the corresponding Hamiltonian density. Finally, we explore the Penrose limit associated with the HT background and compute the corresponding stringy spectrum for the bosonic sector.

Atmospheric-Pressure-Spray, Chemical- Vapor-Deposited Thin-Film Materials Being Developed for High Power-to- Weight-Ratio Space Photovoltaic Applications

NASA Technical Reports Server (NTRS)

Hepp, Aloysius F.; Harris, Jerry D.; Raffaelle, Ryne P.; Banger, Kulbinder K.; Smith, Mark A.; Cowen, Jonathan E.

2001-01-01

The key to achieving high specific power (watts per kilogram) space photovoltaic arrays is the development of high-efficiency thin-film solar cells that are fabricated on lightweight, space-qualified substrates such as Kapton (DuPont) or another polymer film. Cell efficiencies of 20 percent air mass zero (AM0) are required. One of the major obstacles to developing lightweight, flexible, thin-film solar cells is the unavailability of lightweight substrate or superstrate materials that are compatible with current deposition techniques. There are two solutions for working around this problem: (1) develop new substrate or superstrate materials that are compatible with current deposition techniques, or (2) develop new deposition techniques that are compatible with existing materials. The NASA Glenn Research Center has been focusing on the latter approach and has been developing a deposition technique for depositing thin-film absorbers at temperatures below 400 C.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pern, F. J.; Glick, S. H.

We have conducted a series of accelerated exposure test (AET) studies for various crystalline-Si (c-Si) and amorphous-Si (a-Si) cell samples that were encapsulated with different superstrates, pottants, and substrates. Nonuniform browning patterns of ethylene vinyl acetate (EVA) pottants were observed for glass/EVA/glass-encapsulated c-Si cell samples under solar simulator exposures at elevated temperatures. The polymer/polymer-configured laminates with Tedlar or Tefzel did not discolor because of photobleaching reactions, but yellowed with polyester or nylon top films. Delamination was observed for the polyester/EVA layers on a-Si minimodules and for a polyolefin-based thermoplastic pottant at high temperatures. For all tested c-Si cell samples, irregularmore » changes in the current-voltage parameters were observed that could not be accounted for simply by the transmittance changes of the superstrate/pottant layers. Silicone-type adhesives used under UV-transmitting polymer top films were observed to cause greater cell current/efficiency loss than EVA or polyethylene pottants.« less

The B-field soft theorem and its unification with the graviton and dilaton

NASA Astrophysics Data System (ADS)

Di Vecchia, Paolo; Marotta, Raffaele; Mojaza, Matin

2017-10-01

In theories of Einstein gravity coupled with a dilaton and a two-form, a soft theorem for the two-form, known as the Kalb-Ramond B-field, has so far been missing. In this work we fill the gap, and in turn formulate a unified soft theorem valid for gravitons, dilatons and B-fields in any tree-level scattering amplitude involving the three massless states. The new soft theorem is fixed by means of on-shell gauge invariance and enters at the subleading order of the graviton's soft theorem. In contrast to the subsubleading soft behavior of gravitons and dilatons, we show that the soft behavior of B-fields at this order cannot be fully fixed by gauge invariance. Nevertheless, we show that it is possible to establish a gauge invariant decomposition of the amplitudes to any order in the soft expansion. We check explicitly the new soft theorem in the bosonic string and in Type II superstring theories, and furthermore demonstrate that, at the next order in the soft expansion, totally gauge invariant terms appear in both string theories which cannot be factorized into a soft theorem.

Brane SUSY breaking and inflation: Implications for scalar fields and CMB distortion

NASA Astrophysics Data System (ADS)

Sagnotti, Augusto

2014-12-01

I elaborate on a link between the string-scale breaking of supersymmetry that occurs in a class of superstring models and the onset of inflation. The link rests on spatially flat cosmologies supported by a scalar field driven by an exponential potential. If, as in String Theory, this potential is steep enough, under some assumptions that are spelled out in the text the scalar can only climb up as it emerges from an initial singularity. In the presence of another mild exponential, slow-roll inflation is thus injected during the ensuing descent and definite imprints are left in the CMB power spectrum: the quadrupole is systematically reduced and, depending on the choice of two parameters, an oscillatory behavior can also emerge for low multipoles l < 50, in qualitative agreement with WMAP9 and PLANCK data. The experimentally favored value of the spectral index, n s ≈ 0.96, points to a potentially important role for the NS fivebrane, which is unstable in this class of models, in the Early Universe.

Subleading soft graviton theorem for loop amplitudes

NASA Astrophysics Data System (ADS)

Sen, Ashoke

2017-11-01

Superstring field theory gives expressions for heterotic and type II string loop amplitudes that are free from ultraviolet and infrared divergences when the number of non-compact space-time dimensions is five or more. We prove the subleading soft graviton theorem in these theories to all orders in perturbation theory for S-matrix elements of arbitrary number of finite energy external states but only one external soft graviton. We also prove the leading soft graviton theorem for arbitrary number of finite energy external states and arbitrary number of soft gravitons. Since our analysis is based on general properties of one particle irreducible effective action, the results are valid in any theory of quantum gravity that gives finite result for the S-matrix order by order in perturbation theory without violating general coordinate invariance.

Reduced Cu(InGa)Se 2 Thickness in Solar Cells Using a Superstrate Configuration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shafarman, William N.

This project by the Institute of Energy Conversion (IEC) and the Department of Electrical and Computer Engineering at the University of Delaware sought to develop the technology and underlying science to enable reduced cost of Cu(InGa)Se 2 manufacturing by reducing the thickness of the Cu(InGa)Se 2 absorber layer by half compared to typical production. The approach to achieve this was to use the superstrate cell configuration in which light is incident on the cell through the glass. This structure facilitates optical enhancement approaches needed to achieve high efficiency with Cu(InGa)Se 2 thicknesses less than 1 µm. The primary objective wasmore » to demonstrate a Cu(InGa)Se 2 cell with absorber thickness 0.5 - 0.7 µm and 17% efficiency, along with a quantitative loss analysis to define a pathway to 20% efficiency. Additional objectives were the development of stable TCO and buffer layers or contact layers to withstand the Cu(InGa)Se 2 deposition temperature and of advanced optical enhancement methods. The underlying fundamental science needed to effectively transition these outcomes to large scale was addressed by extensive materials and device characterization and by development of comprehensive optical models. Two different superstrate configurations have been investigated. A frontwall cell is illuminated through the glass to the primary front junction of the device. This configuration has been used for previous efforts on superstrate Cu(InGa)Se 2 but performance has been limited by interdiffusion or reaction with CdS or other buffer layers. In this project, several approaches to overcome these limitations were explored using CdS, ZnO and ZnSe buffer layers. In each case, mechanisms that limit device performance were identified using detailed characterization of the materials and junctions. Due to the junction formation difficulties, efforts were concentrated on a new backwall configuration in which light is incident through the substrate into the back of the absorber layer. The primary junction is then formed after Cu(InGa)Se 2 deposition. This allows the potential benefits of superstrate cells for optical enhancement while maintaining processing advantages of the substrate configuration and avoiding the harmful effects of high temperature deposition on p-n junction formation. Backwall devices have outperformed substrate cells at absorber thicknesses of 0.1-0.5 µm through enhanced JSC due to easy incorporation of a Ag reflector and, with light incident on the absorber, the elimination of parasitic absorption in the CdS buffer. An efficiency of 9.7% has been achieved for a backwall Cu(InGa)Se 2 device with absorber thickness ~0.4 μm. A critical achievement that enabled implementation of the backwall cell was the development of a transparent back contact using MoO 3 or WO 3. Processes for controlled deposition of each material by reactive rf sputtering from metal targets were developed. These contacts have wide bandgaps making them well-suited for application as contacts for backwall devices as well as potential use in bifacial cells and as the top cell of tandem CuInSe 2-based devices. Optical enhancement will be critical for further improvements. Wet chemical texturing of ZnO films has been developed for a simple, low cost light-trapping scheme for backwall superstrate devices to enhance long wavelength quantum efficiency. An aqueous oxalic acid etch was developed and found to strongly texture sputtered ZnO with high haze ≈ 0.9 observed across the whole spectrum. And finally, advanced optical models have been developed to assist the characterization and optimization of Cu(InGa)Se 2 cells with thin absorbers« less

Enhancement of gaps in thin graphitic films for heterostructure formation

NASA Astrophysics Data System (ADS)

Hague, J. P.

2014-04-01

There are a large number of atomically thin graphitic films with a structure similar to that of graphene. These films have a spread of band gaps relating to their ionicity and, also, to the substrate on which they are grown. Such films could have a range of applications in digital electronics, where graphene is difficult to use. I use the dynamical cluster approximation to show how electron-phonon coupling between film and substrate can enhance these gaps in a way that depends on the range and strength of the coupling. It is found that one of the driving factors in this effect is a charge density wave instability for electrons on a honeycomb lattice that can open a gap in monolayer graphene. The enhancement at intermediate coupling is sufficiently large that spatially varying substrates and superstrates could be used to create heterostructures in thin graphitic films with position-dependent electron-phonon coupling and gaps, leading to advanced electronic components.

Atomic-resolution characterization of the effects of CdCl2 treatment on poly-crystalline CdTe thin films

NASA Astrophysics Data System (ADS)

Paulauskas, T.; Buurma, C.; Colegrove, E.; Guo, Z.; Sivananthan, S.; Chan, M. K. Y.; Klie, R. F.

2014-08-01

Poly-crystalline CdTe thin films on glass are used in commercial solar-cell superstrate devices. It is well known that post-deposition annealing of the CdTe thin films in a CdCl2 environment significantly increases the device performance, but a fundamental understanding of the effects of such annealing has not been achieved. In this Letter, we report a change in the stoichiometry across twin boundaries in CdTe and propose that native point defects alone cannot account for this variation. Upon annealing in CdCl2, we find that the stoichiometry is restored. Our experimental measurements using atomic-resolution high-angle annular dark field imaging, electron energy-loss spectroscopy, and energy dispersive X-ray spectroscopy in a scanning transmission electron microscope are supported by first-principles density functional theory calculations.

A universality in pp-waves

NASA Astrophysics Data System (ADS)

Mukhopadhyay, Partha

2007-06-01

We discuss a universality property of any covariant field theory in space-time expanded around pp-wave backgrounds. According to this property the space-time lagrangian density evaluated on a restricted set of field configurations, called universal sector, turns out to be same around all the pp-waves, even off-shell, with same transverse space and same profiles for the background scalars. In this paper we restrict our discussion to tensorial fields only. In the context of bosonic string theory we consider on-shell pp-waves and argue that universality requires the existence of a universal sector of world-sheet operators whose correlation functions are insensitive to the pp-wave nature of the metric and the background gauge flux. Such results can also be reproduced using the world-sheet conformal field theory. We also study such pp-waves in non-polynomial closed string field theory (CSFT). In particular, we argue that for an off-shell pp-wave ansatz with flat transverse space and dilaton independent of transverse coordinates the field redefinition relating the low energy effective field theory and CSFT with all the massive modes integrated out is at most quadratic in fields. Because of this simplification it is expected that the off-shell pp-waves can be identified on the two sides. Furthermore, given the massless pp-wave field configurations, an iterative method for computing the higher massive modes using the CSFT equations of motion has been discussed. All our bosonic string theory analyses can be generalised to the common Neveu-Schwarz sector of superstrings.

Tachyons in the Galilean limit

NASA Astrophysics Data System (ADS)

Batlle, Carles; Gomis, Joaquim; Mezincescu, Luca; Townsend, Paul K.

2017-04-01

The Souriau massless Galilean particle of "colour" k and spin s is shown to be the Galilean limit of the Souriau tachyon of mass m = ik and spin s. We compare and contrast this result with the Galilean limit of the Nambu-Goto string and Green-Schwarz superstring.

Stochastic background from cosmic (super)strings: Popcorn-like and (Gaussian) continuous regimes

NASA Astrophysics Data System (ADS)

Regimbau, Tania; Giampanis, Stefanos; Siemens, Xavier; Mandic, Vuk

2012-03-01

In the era of the next generation of gravitational wave experiments a stochastic background from cusps of cosmic (super)strings is expected to be probed and, if not detected, to be significantly constrained. A popcornlike background can be, for part of the parameter space, as pronounced as the (Gaussian) continuous contribution from unresolved sources that overlap in frequency and time. We study both contributions from unresolved cosmic string cusps over a range of frequencies relevant to ground based interferometers, such as the LIGO/Virgo second generation and Einstein Telescope third generation detectors, the space antenna LISA, and pulsar timing arrays. We compute the sensitivity (at the 2σ level) in the parameter space for the LIGO/Virgo second generation detector, the Einstein Telescope detector, LISA, and pulsar timing arrays. We conclude that the popcorn regime is complementary to the continuous background. Its detection could therefore enhance confidence in a stochastic background detection and possibly help determine fundamental string parameters such as the string tension and the reconnection probability.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pern, F.J.; Glick, S.H.

We have conducted a series of accelerated exposure test (AET) studies for various crystalline-Si (c-Si) and amorphous-Si (a-Si) cell samples that were encapsulated with different superstrates, pottants, and substrates. Nonuniform browning patterns of ethylene vinyl acetate (EVA) pottants were observed for glass/EVA/glass-encapsulated c-Si cell samples under solar simulator exposures at elevated temperatures. The polymer/polymer-configured laminates with Tedlar or Tefzel did not discolor because of photobleaching reactions, but yellowed with polyester or nylon top films. Delamination was observed for the polyester/EVE layers on a-Si minimodules and for a polyolefin-based thermoplastic pottant at high temperatures. For all tested c-Si cell samples, irregularmore » changes in the current-voltage parameters were observed that could not be accounted for simply by the transmittance changes of the superstrate/pottant layers. Silicone-type adhesives used under UV-transmitting polymer top films were observed to cause greater cell current/efficiency loss than EVA or polyethylene pottants. {copyright} {ital 1999 American Institute of Physics.}« less

Perturbations and moduli space dynamics of tachyon kinks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hindmarsh, Mark; Li Huiquan

2008-03-15

The dynamic process of unstable D-branes decaying into stable ones with one dimension lower can be described by a tachyon field with a Dirac-Born-Infeld effective action. In this paper we investigate the fluctuation modes of the tachyon field around a two-parameter family of static solutions representing an array of brane-antibrane pairs. Besides a pair of zero modes associated with the parameters of the solution, and instabilities associated with annihilation of the brane-antibrane pairs, we find states corresponding to excitations of the tachyon field around the brane and in the bulk. In the limit that the brane thickness tends to zero,more » the support of the eigenmodes is limited to the brane, consistent with the idea that propagating tachyon modes drop out of the spectrum as the tachyon field approaches its ground state. The zero modes, and other low-lying excited states, show a fourfold degeneracy in this limit, which can be identified with some of the massless superstring modes in the brane-antibrane system. Finally, we also discuss the slow motion of the solution corresponding to the decay process in the moduli space, finding a trajectory which oscillates periodically between the unstable D-brane and the brane-antibrane pairs of one dimension lower.« less

Remarks on non-BPS string amplitudes and their all order α' contact interactions in IIB, IIA

NASA Astrophysics Data System (ADS)

Hatefi, Ehsan

2017-03-01

We explore the entire form of S-Matrix elements of a potential C n-1 Ramond-Ramond (RR) form field, a tachyon and two transverse scalar fields on both world volume and transverse directions of type IIB and IIA superstring theories. Apart from < {V}_{C^{-2}}{V}_{φ^0}{V}_{φ^0}{V}_{T^0}\\rangle the other scattering amplitude, namely < {V}_{C^{-1}}{V}_{φ^{-1}}{V}_{φ^0}{V}_{T^0}\\rangle is also revealed. We then start to compare all singularity structures of symmetric and asymmetric analysis, generating all infinite singularity structures as well as all order α' contact interactions on the whole directions. This leads to deriving various new contact terms and several new restricted Bianchi identities in both type IIB and IIA. It is also shown that just some of the new couplings of type IIB (IIA) string theory can be re-verified in an Effective Field Theory (EFT) by pull-back of branes. To construct the rest of S-matrix elements one needs to first derive restricted world volume (or bulk) Bianchi identities and then discover new EFT couplings in both type IIB and IIA. Finally the presence of commutator of scalar fields inside the exponential of Wess-Zumino action for non-BPS branes has been confirmed as well.

The Rising Landscape: A Visual Exploration of Superstring Revolutions in Physics.

ERIC Educational Resources Information Center

Chen, Chaomei; Kuljis, Jasna

2003-01-01

Discussion of knowledge domain visualization focuses on practical issues concerning modeling and visualizing scientific revolutions. Studies growth patterns of specialties derived from citation and cocitation data on string theory in physics, using the general framework of Thomas Kuhn's structure of scientific revolutions. (Author/LRW)

α '-corrected black holes in String Theory

NASA Astrophysics Data System (ADS)

Cano, Pablo A.; Meessen, Patrick; Ortín, Tomás; Ramírez, Pedro F.

2018-05-01

We consider the well-known solution of the Heterotic Superstring effective action to zeroth order in α ' that describes the intersection of a fundamental string with momentum and a solitonic 5-brane and which gives a 3-charge, static, extremal, supersymmetric black hole in 5 dimensions upon dimensional reduction on T5. We compute explicitly the first-order in α ' corrections to this solution, including SU(2) Yang-Mills fields which can be used to cancel some of these corrections and we study the main properties of this α '-corrected solution: supersymmetry, values of the near-horizon and asymptotic charges, behavior under α '-corrected T-duality, value of the entropy (using Wald formula directly in 10 dimensions), existence of small black holes etc. The value obtained for the entropy agrees, within the limits of approximation, with that obtained by microscopic methods. The α ' corrections coming from Wald's formula prove crucial for this result.

AdS5×S(5) mirror model as a string sigma model.

PubMed

Arutyunov, Gleb; van Tongeren, Stijn J

2014-12-31

Doing a double Wick rotation in the world sheet theory of the light cone AdS5×S(5) superstring results in an inequivalent, so-called mirror theory that plays a central role in the field of integrability in the AdS-CFT correspondence. We show that this mirror theory can be interpreted as the light cone theory of a free string on a different background. This background is related to dS5×H(5) by a double T-duality, and has hidden supersymmetry. The geometry can also be extracted from an integrable deformation of the AdS5×S(5) sigma model, and we prove the observed mirror duality of these deformed models at the bosonic level as a byproduct. While we focus on AdS5×S(5), our results apply more generally.

Microstates of D1-D5(-P) black holes, as interacting D-branes

NASA Astrophysics Data System (ADS)

Morita, Takeshi; Shiba, Shotaro

2015-07-01

In our previous study (Morita et al., 2014 [1]), we figured out that the thermodynamics of the near extremal black p-branes can be explained as the collective motions of gravitationally interacting elementary p-branes (the p-soup proposal). We test this proposal in the near-extremal D1-D5 and D1-D5-P black holes and show that their thermodynamics also can be explained in a similar fashion, i.e. via the collective motions of the interacting elementary D1-branes and D5-branes (and waves). It may imply that the microscopic origins of these intersecting black branes and the black p-brane are explained in the unified picture. We also argue the relation between the p-soup proposal and the conformal field theory calculations of the D1-D5(-P) black holes in superstring theory.

Complete N-point superstring disk amplitude II. Amplitude and hypergeometric function structure

NASA Astrophysics Data System (ADS)

Mafra, Carlos R.; Schlotterer, Oliver; Stieberger, Stephan

2013-08-01

Using the pure spinor formalism in part I (Mafra et al., preprint [1]) we compute the complete tree-level amplitude of N massless open strings and find a striking simple and compact form in terms of minimal building blocks: the full N-point amplitude is expressed by a sum over (N-3)! Yang-Mills partial subamplitudes each multiplying a multiple Gaussian hypergeometric function. While the former capture the space-time kinematics of the amplitude the latter encode the string effects. This result disguises a lot of structure linking aspects of gauge amplitudes as color and kinematics with properties of generalized Euler integrals. In this part II the structure of the multiple hypergeometric functions is analyzed in detail: their relations to monodromy equations, their minimal basis structure, and methods to determine their poles and transcendentality properties are proposed. Finally, a Gröbner basis analysis provides independent sets of rational functions in the Euler integrals. In contrast to [1] here we use momenta redefined by a factor of i. As a consequence the signs of the kinematic invariants are flipped, e.g. |→|.

Light trapping in thin-film solar cells measured by Raman spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ledinský, M., E-mail: ledinsky@fzu.cz; Photovoltaics and Thin Film Electronics Laboratory, Institute of Microengineering; Moulin, E.

2014-09-15

In this study, Raman spectroscopy is used as a tool to determine the light-trapping capability of textured ZnO front electrodes implemented in microcrystalline silicon (μc-Si:H) solar cells. Microcrystalline silicon films deposited on superstrates of various roughnesses are characterized by Raman micro-spectroscopy at excitation wavelengths of 442 nm, 514 nm, 633 nm, and 785 nm, respectively. The way to measure quantitatively and with a high level of reproducibility the Raman intensity is described in details. By varying the superstrate texture and with it the light trapping in the μc-Si:H absorber layer, we find significant differences in the absolute Raman intensity measured in the near infraredmore » wavelength region (where light trapping is relevant). A good agreement between the absolute Raman intensity and the external quantum efficiency of the μc-Si:H solar cells is obtained, demonstrating the validity of the introduced method. Applications to thin-film solar cells, in general, and other optoelectronic devices are discussed.« less

Top-quark mass coupling and classification of weakly coupled heterotic superstring vacua

NASA Astrophysics Data System (ADS)

Rizos, J.

2014-06-01

The quest for the Standard Model among the huge number of string vacua is usually based on a set of phenomenological criteria related to the massless spectrum of string models. In this work we study criteria associated with interactions in the effective low energy theory and in particular with the presence of the coupling that provides mass to the top quark. Working in the context of the free-fermionic formulation of the heterotic superstring, we demonstrate that, in a big class of phenomenologically promising compactifications, these criteria can be expressed entirely in terms of the generalised GSO projection coefficients entering the definition of the models. They are shown to be very efficient in identifying phenomenologically viable vacua, especially in the framework of computer-based search, as they are met by approximately one every models. We apply our results in the investigation of a class of supersymmetric Pati-Salam vacua, comprising configurations, and we show that when combined with other phenomenological requirements they lead to a relatively small set of about Standard Model compatible models that can be fully classified.

Advances in all-sputtered CdTe solar cells on flexible substrates

NASA Astrophysics Data System (ADS)

Wieland, Kristopher; Mahabaduge, Hasitha; Vasko, Anthony; Compaan, Alvin

2010-03-01

The University of Toledo II-VI semiconductor group has developed magnetron sputtering (MS) for the deposition of thin films of CdS, CdTe, and related materials for photovoltaic applications. On glass superstrates, we have reached air mass 1.5 efficiencies of 14%.[1] Recently we have studied the use of MS for the fabrication of thin-film CdS/CdTe cells on flexible polyimide superstrates. This takes advantage of the high film quality that can be achieved at substrate temperatures below 300 C when RF MS is used. Our recent CdS/CdTe solar cells have reached 10.5% on flexible polyimide substrates. [2] This all-sputtered cell (except for back contact) has a structure of polyimide/ZnO:Al/ZnO/CdS/CdTe/Cu/Au. The physics of this device will be discussed through the use of spectral quantum efficiency and current-voltage measurements as a function of CdTe layer thickness. Pathways toward further increases in device efficiencies will also be discussed. [1] Appl. Phys. Lett. 85, 684 (2004) [2] Phys. Stat. Sol. (B) 241, No. 3, 779--782 (2004)

Topological defects in alternative theories to cosmic inflation and string cosmology

NASA Astrophysics Data System (ADS)

Alexander, Stephon H. S.

The physics of the Early Universe is described in terms of the inflationary paradigm, which is based on a marriage between Einstein's general theory of relativity minimally coupled to quantum field theory. Inflation was posed to solve some of the outstanding problems of the Standard Big Bang Cosmology (SBB) such as the horizon, formation of structure and monopole problems. Despite its observational and theoretical successes, inflation is plagued with fine tuning and initial singularity problems. On the other hand, superstring/M theory, a theory of quantum gravity, possesses symmetries which naturally avoid space-time singularities. This thesis investigates alternative theories to cosmic inflation for solving the initial singularity, horizon and monopole problems, making use of topological defects. It was proposed by Dvali, Liu and Vaschaspati that the monopole problem can be solved without inflation if domain walls "sweep" up the monopoles in the early universe, thus reducing their number density significantly. Necessary for this mechanism to work is the presence of an attractive force between the monopole and the domain wall as well as a channel for the monopole's unwinding. We show numerically and analytically in two field theory models that for global defects the attraction is a universal result but the unwinding is model specific. The second part of this thesis investigates a string/M theory inspired model for solving the horizon problem. It was proposed by Moffat, Albrecht and Magueijo that the horizon problem is solved with a "phase transition" associated with a varying speed of light before the surface of last scattering. We provide a string/M theory mechanism based on assuming that our space-time is a D-3 brane probing a bulk supergravity black hole bulk background. This mechanism provides the necessary time variation of the velocity of light to solve the horizon problem. We suggest a mechanism which stablilizes the speed of light on the D-3 brane. We finally address the cosmological initial singularity problem using the target space duality inherent in string/M theory. It was suggested by Brandenberger and Vafa that superstring theory can solve the singularity problem and in addition explain why only three spatial dimensions can become large. We show that under specific conditions this mechanism still persists when including the effects of D-branes.

Remarks on non-BPS string amplitudes and their all order α' contact interactions in IIB, IIA

DOE PAGES

Hatefi, Ehsan

2017-03-06

Here, we explore the entire form of S-Matrix elements of a potential C n–1 Ramond-Ramond (RR) form field, a tachyon and two transverse scalar fields on both world volume and transverse directions of type IIB and IIA superstring theories. Apart from V C–2V Φ0V Φ0V T0 the other scattering amplitude, namely V C–1V Φ–1V Φ0V T0 is also revealed. We then start to compare all singularity structures of symmetric and asymmetric analysis, generating all infinite singularity structures as well as all order α' contact interactions on the whole directions. This leads to deriving various new contact terms and several newmore » restricted Bianchi identities in both type IIB and IIA. It is also shown that just some of the new couplings of type IIB (IIA) string theory can be re-verified in an Effective Field Theory (EFT) by pull-back of branes. To construct the rest of S-matrix elements one needs to first derive restricted world volume (or bulk) Bianchi identities and then discover new EFT couplings in both type IIB and IIA. Finally the presence of commutator of scalar fields inside the exponential of Wess-Zumino action for non-BPS branes has been confirmed as well.« less

Novel Implementations of Wideband Tightly Coupled Dipole Arrays for Wide-Angle Scanning

NASA Astrophysics Data System (ADS)

Yetisir, Ersin

Ultra-wideband (UWB) antennas and arrays are essential for high data rate communications and for addressing spectrum congestion. Tightly coupled dipole arrays (TCDAs) are of particular interest due to their low-profile, bandwidth and scanning range. But existing UWB (>3:1 bandwidth) arrays still suffer from limited scanning, particularly at angles beyond 45° from broadside. Almost all previous wideband TCDAs have employed dielectric layers above the antenna aperture to improve scanning while maintaining impedance bandwidth. But even so, these UWB arrays have been limited to no more than 60° away from broadside. In this work, we propose to replace the dielectric superstrate with frequency selective surfaces (FSS). In effect, the FSS is used to create an effective dielectric layer placed over the antenna array. FSS also enables anisotropic responses and more design freedom than conventional isotropic dielectric substrates. Another important aspect of the FSS is its ease of fabrication and low weight, both critical for mobile platforms (e.g. unmanned air vehicles), especially at lower microwave frequencies. Specifically, it can be fabricated using standard printed circuit technology and integrated on a single board with active radiating elements and feed lines. In addition to the FSS superstrate, a modified version of the stripline-based folded Marchand balun is presented. As usual the balun serves to match the 50Ω coaxial cable to the high input impedance ( 200Ω) at the terminals of array elements. Doing so, earlier Wilkinson power dividers, which degrade efficiency during E-plane scanning, are eliminated. To verify the proposed array concept, 12x12 TCDA prototype was fabricated using the modified balun and the new FSS superstrate layer. The design and experimental data showed an impedance bandwidth of 6.1:1 with VSWR<3.2. The latter VSWR was achieved even when scanning down to +/-60° in the H-plane, +/-70° in the D-plane and +/-75° in the E-plane. All array components, including the FSS, radiating dipoles and the feed lines are placed on the same PCB, vertically oriented over the array ground plane, resulting in a low-cost and light-weight structure. The effects of finite aperture sizes in presence of FSS or dielectric superstrates are also considered. Specifically, we compare the performance of finite TCDAs with FSS or dielectric loading. The performance metric is beam pointing accuracy for moderate array sizes ( 30dBi gain) with various edge element terminations. It is shown that even terminating two unit cells at the array edges can provide effective suppression of edge-born waves and achieve excellent beam accuracy. This is the case when both the FSS elements and radiating dipoles are resistively loaded in the unit-cells along the aperture edges.

Transparent superstrate terrestrial solar cell module

NASA Technical Reports Server (NTRS)

1977-01-01

The design, development, fabrication, and testing of the transparent solar cell module were examined. Cell performance and material process characteristics were determined by extensive tests and design modifications were made prior to preproduction fabrication. These tests included three cell submodules and two full size engineering modules. Along with hardware and test activity, engineering documentation was prepared and submitted.

Survival of pq -superstrings in field theory simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lizarraga, Joanes; Urrestilla, Jon, E-mail: joanes.lizarraga@ehu.eus, E-mail: jon.urrestilla@ehu.eus

2016-04-01

We perform large-scale field theoretical simulations in expanding universe to characterize a network of strings that can form composed bound states. The network consists of two copies of Abelian Higgs strings (which we label p and q , respectively) coupled via a potential term to give pq bound states. The simulations are performed using two different kinds of initial conditions: the first one with a network of p - and q -strings, and the second one with a network of q - and pq -strings. This way, we start from two opposite situations: one with no initial pq -strings, andmore » one with a large initial number of pq -strings. We find that in both cases the system scales, and in both cases the system prefers to have a low fraction of pq -strings. This is somewhat surprising in the case for the second type of conditions, showing that the unzipping mechanism is very efficient. We also find hints that both initial conditions tend to asymptote to a common configuration, though we would need a larger dynamical range to confirm it. The average velocities of the different types of strings in the network have also been explored for the first time.« less

Solar-Array Substrate From Glass-Reinforced Concrete

NASA Technical Reports Server (NTRS)

Eirls, J. L.

1985-01-01

Design elminiates glass superstrate and associated metal framing. Panel has two trapezoidal stiffening ribs for structural support. Strategic placement of ribs with embedded support tubes (standard PVC tubing) minimizes bending moments and resulting stresses produced by installation and windloads. Glass-reinforced concrete panel has smooth flat surface suitable for solar substrate and includes structural bracing for rigidity and design adaptable to mass production.

Branes and the Kraft-Procesi transition: classical case

NASA Astrophysics Data System (ADS)

Cabrera, Santiago; Hanany, Amihay

2018-04-01

Moduli spaces of a large set of 3 d N=4 effective gauge theories are known to be closures of nilpotent orbits. This set of theories has recently acquired a special status, due to Namikawa's theorem. As a consequence of this theorem, closures of nilpotent orbits are the simplest non-trivial moduli spaces that can be found in three dimensional theories with eight supercharges. In the early 80's mathematicians Hanspeter Kraft and Claudio Procesi characterized an inclusion relation between nilpotent orbit closures of the same classical Lie algebra. We recently [1] showed a physical realization of their work in terms of the motion of D3-branes on the Type IIB superstring embedding of the effective gauge theories. This analysis is restricted to A-type Lie algebras. The present note expands our previous discussion to the remaining classical cases: orthogonal and symplectic algebras. In order to do so we introduce O3-planes in the superstring description. We also find a brane realization for the mathematical map between two partitions of the same integer number known as collapse. Another result is that basic Kraft-Procesi transitions turn out to be described by the moduli space of orthosymplectic quivers with varying boundary conditions.

A New Metasurface Superstrate Structure for Antenna Performance Enhancement.

PubMed

Islam, Mohammad Tariqul; Ullah, Mohammad Habib; Singh, Mandeep Jit; Faruque, Mohammad Rashed Iqbal

2013-07-31

A new metasurface superstrate structure (MSS)-loaded dual band microstrip line-fed small patch antenna is presented in this paper. The proposed antenna was designed on a ceramic-filled bioplastic sandwich substrate with a high dielectric constant. The proposed 7 × 6 element, square-shaped, single-sided MSS significantly improved the bandwidth and gain of the proposed antenna. The proposed MSS incorporated a slotted patch antenna that effectively increased the measured operating bandwidth from 13.3% to 18.8% and from 14.8% to 23.2% in the lower and upper bands, respectively. Moreover, the average gain of the proposed MSS-based antenna was enhanced from 2.12 dBi to 3.02 dBi in the lower band and from 4.10 dBi to 5.28 dBi in the upper band compared to the patch antenna alone. In addition to the bandwidth and gain improvements, more directive radiation characteristics were also observed from the MSS antenna compared to the patch itself. The effects of the MSS elements and the ground plane length on the reflection coefficient of the antenna were analyzed and optimized. The overall performance makes the proposed antenna appropriate for RFID and WLAN applications.

A New Metasurface Superstrate Structure for Antenna Performance Enhancement

PubMed Central

Islam, Mohammad Tariqul; Ullah, Mohammad Habib; Singh, Mandeep Jit; Faruque, Mohammad Rashed Iqbal

2013-01-01

A new metasurface superstrate structure (MSS)-loaded dual band microstrip line-fed small patch antenna is presented in this paper. The proposed antenna was designed on a ceramic-filled bioplastic sandwich substrate with a high dielectric constant. The proposed 7 × 6 element, square-shaped, single-sided MSS significantly improved the bandwidth and gain of the proposed antenna. The proposed MSS incorporated a slotted patch antenna that effectively increased the measured operating bandwidth from 13.3% to 18.8% and from 14.8% to 23.2% in the lower and upper bands, respectively. Moreover, the average gain of the proposed MSS-based antenna was enhanced from 2.12 dBi to 3.02 dBi in the lower band and from 4.10 dBi to 5.28 dBi in the upper band compared to the patch antenna alone. In addition to the bandwidth and gain improvements, more directive radiation characteristics were also observed from the MSS antenna compared to the patch itself. The effects of the MSS elements and the ground plane length on the reflection coefficient of the antenna were analyzed and optimized. The overall performance makes the proposed antenna appropriate for RFID and WLAN applications. PMID:28811432

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pern, F.J.; Glick, S.H.; Czanderna, A.W.

Results from extensive studies of the commercial ethylene vinyl acetate (EVA) formulations show that the UV absorber and curing-generated UV-excitable, {alpha},{beta}-unsaturated carbonyl chromophores facilitate the EVA discoloration, which is further enhanced by curing-generated acetic acid and probably residual peroxide curing agent also. Formation and concentration of the UV-excitable chromophores are substantially promoted by the antioxidant, Naugard P. The discoloration rate is greater under higher UV light intensity and temperatures. Heating in the dark at elevated temperatures (e.g., 85&hthinsp;{degree}C) in the air for {approximately}200 days only results in light yellowing. The discoloration reactions compete with photobleaching reactions, which destroy curing-generated chromophoresmore » and result in non-discoloring of EVA. By using better performance stabilizers to minimize the curing-generated UV-excitable chromophores, a new fast curing agent, and no UV absorber, the NREL-developed EVA formulations show a superior photothermal stability against browning to the commercial counterparts. Alternatively, the discoloration rate of the commercial EVA pottants can be considerably reduced by using UV-filtering glass superstrates that largely inhibit the UV-induced photooxidation reactions, or completely eliminated by using air-permeable polymer superstrate films that enable photobleaching reactions. {copyright} {ital 1999 American Institute of Physics.}« less

Supersymmetric solutions of the cosmological, gauged, ℂ magic model

NASA Astrophysics Data System (ADS)

Chimento, Samuele; Ortín, Tomás; Ruipérez, Alejandro

2018-05-01

We construct supersymmetric solutions of theories of gauged N = 1 , d = 5 supergravity coupled to vector multiplets with a U(1)R Abelian (Fayet-Iliopoulos) gauging and an independent SU(2) gauging associated to an SU(2) isometry group of the Real Special scalar manifold. These theories provide minimal supersymmetrizations of 5-dimensional SU(2) Einstein-Yang-Mills theories with negative cosmological constant. We consider a minimal model with these gauge groups and the "magic model" based on the Jordan algebra J 3 ℂ with gauge group SU(3) × U(1)R, which is a consistent truncation of maximal SO(6)-gauged supergravity in d = 5 and whose solutions can be embedded in Type IIB Superstring Theory. We find several solutions containing selfdual SU(2) instantons, some of which asymptote to AdS5 and some of which are very small, supersymmetric, deformations of AdS5. We also show how some of those solutions can be embedded in Romans' SU(2) × U(1)-gauged half-maximal supergravity, which was obtained by Lu, Pope and Tran by compactification of the Type IIB Superstring effective action. This provides another way of uplifting those solutions to 10 dimensions.

FSA field test report, 1980 - 1982

NASA Technical Reports Server (NTRS)

Maxwell, H. G.; Grimmett, C. A.; Repar, J.; Frickland, P. O.; Amy, J. A.

1983-01-01

Photovoltaic modules made of new and developing materials were tested in a continuing study of weatherability, compatibility, and corrosion protection. Over a two-year period, 365 two-cell submodules have been exposed for various intervals at three outdoor sites in Southern California or subjected to laboratory acceptance tests. Results to date show little loss of maximum power output, except in two types of modules. In the first of these, failure is due to cell fracture from the stresses that arise as water is regained from the surrounding air by a hardboard substrate, which shrank as it dried during its encapsulation in plastic film at 150 C in vacuo. In the second, the glass superstrate is sensitive to cracking, which also damages the cells electrostatically bonded to it; inadequate bonding of interconnects to the cells is also a problem in these modules. In a third type of module, a polyurethane pottant has begun to yellow, though as yet without significant effect on maximum power output.

Improved photostability of NREL-developed EVA pottant formulations for PV module encapsulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pern, F.J.; Glick, S.H.

1997-12-31

Several new formulations of ethylene vinyl acetate (EVA)-based encapsulant have been developed at NREL and have greatly improved photostability against UV-induced discoloration. The new EVA formulations use stabilizers and a curing agent entirely different from any of those used in existing formulations known to the authors. No discoloration was observed for the laminated and cured samples that were exposed to a {approximately}5-sun UV light (300--400 nm) from a solar simulator at a black panel temperature (BPT) of 44 {+-} 2 C for {approximately}3250 h followed by at 85 C for {approximately}850 h, an equivalent of approximately 9.4 years for anmore » average 6-h daily, 1-sun solar exposure in Golden, Colorado. Under the same conditions, substantial discoloration and premature delamination were observed for two commercial EVA formulations. Encapsulation with the new EVA formulations should extend the long-term stability for PV modules in the field, especially when coupled with UV-filtering, Ce-containing glass superstrates.« less

COSMOS-e'-soft Higgsotic attractors

NASA Astrophysics Data System (ADS)

Choudhury, Sayantan

2017-07-01

In this work, we have developed an elegant algorithm to study the cosmological consequences from a huge class of quantum field theories (i.e. superstring theory, supergravity, extra dimensional theory, modified gravity, etc.), which are equivalently described by soft attractors in the effective field theory framework. In this description we have restricted our analysis for two scalar fields - dilaton and Higgsotic fields minimally coupled with Einstein gravity, which can be generalized for any arbitrary number of scalar field contents with generalized non-canonical and non-minimal interactions. We have explicitly used R^2 gravity, from which we have studied the attractor and non-attractor phases by exactly computing two point, three point and four point correlation functions from scalar fluctuations using the In-In (Schwinger-Keldysh) and the δ N formalisms. We have also presented theoretical bounds on the amplitude, tilt and running of the primordial power spectrum, various shapes (equilateral, squeezed, folded kite or counter-collinear) of the amplitude as obtained from three and four point scalar functions, which are consistent with observed data. Also the results from two point tensor fluctuations and the field excursion formula are explicitly presented for the attractor and non-attractor phase. Further, reheating constraints, scale dependent behavior of the couplings and the dynamical solution for the dilaton and Higgsotic fields are also presented. New sets of consistency relations between two, three and four point observables are also presented, which shows significant deviation from canonical slow-roll models. Additionally, three possible theoretical proposals have presented to overcome the tachyonic instability at the time of late time acceleration. Finally, we have also provided the bulk interpretation from the three and four point scalar correlation functions for completeness.

Relativistic strings - From soap films to a grand unified theory

NASA Astrophysics Data System (ADS)

Nesterenko, V. V.

1986-11-01

The concept of relativistic strings is considered in connection with the theory of minimal surfaces (e.g., soap films stretched onto closed wire contours). The role of relativistic strings in hadron physics is discussed. Attention is then given to the creation of a grand unified theory on the basis of the superstring concept. Finally, the role of relativistic strings in cosmology is examined.

Opto-electronic properties of P-doped nc-Si–QD/a-SiC:H thin films as foundation layer for all-Si solar cells in superstrate configuration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kar, Debjit; Das, Debajyoti, E-mail: erdd@iacs.res.in

2016-07-14

With the advent of nc-Si solar cells having improved stability, the efficient growth of nc-Si i-layer of the top cell of an efficient all-Si solar cell in the superstrate configuration prefers nc-Si n-layer as its substrate. Accordingly, a wide band gap and high conducting nc-Si alloy material is a basic requirement at the n-layer. Present investigation deals with the development of phosphorous doped n-type nanocrystalline silicon quantum dots embedded in hydrogenated amorphous silicon carbide (nc-Si–QD/a-SiC:H) hetero-structure films, wherein the optical band gap can be widened by the presence of Si–C bonds in the amorphous matrix and the embedded high densitymore » tiny nc-Si–QDs could provide high electrical conductivity, particularly in P-doped condition. The nc-Si–QDs simultaneously facilitate further widening of the optical band gap by virtue of the associated quantum confinement effect. A complete investigation has been made on the electrical transport phenomena involving charge transfer by tunneling and thermionic emission prevailing in n-type nc-Si–QD/a-SiC:H thin films. Their correlation with different phases of the specific heterostructure has been carried out for detailed understanding of the material, in order to improve its device applicability. The n-type nc-Si–QD/a-SiC:H films exhibit a thermally activated electrical transport above room temperature and multi-phonon hopping (MPH) below room temperature, involving defects in the amorphous phase and the grain-boundary region. The n-type nc-Si–QD/a-SiC:H films grown at ∼300 °C, demonstrating wide optical gap ∼1.86–1.96 eV and corresponding high electrical conductivity ∼4.5 × 10{sup −1}–1.4 × 10{sup −2} S cm{sup −1}, deserve to be an effective foundation layer for the top nc-Si sub-cell of all-Si solar cells in n-i-p structure with superstrate configuration.« less

Superstring Compactification and Low Energy Phenomenology.

NASA Astrophysics Data System (ADS)

Mohapatra, Pramoda Kumar

We have presented some aspects of Superstring compactification from 10 to 4 dimensions and the effect of different types of compactification of the extra 6 dimensions on the low energy physics. We have reviewed the consequences of demanding the extra 6 dimensions to form a manifold as well as an N = 1 Supersymmetry at low energies. While doing this we have also highlighted some of the fundamental phenomenological problems like proton decay and neutrino mass and their possible solutions. The dissertation includes a description of the method of calculation of discrete symmetries and Yukawa couplings between different fermions and mirror fermions in these kinds of manifold compactification. The explicit calculations for one particular case with three fermion generations is presented. The reasons for the necessity of an intermediate scale of symmetry breaking (between Plank scale and the electro-weak scale) are explained and one particular scenerio of such symmetry breaking which preserves Supersymmetry is given. We have studied the effect of E _6 singlets on F-flatness and on the phenomenology. We have also reviewed the idea of compactification in a completely different way, i.e. not on a regular manifold but on a manifold with singularities called an orbifold. We have shown that with the so-called standard embedding, meaning identifying the gauge connection with the spin connection, needed for anomaly cancellation and modular invariance, only one model has a chance of being phenomenologically realistic. We have provided explicit tables of all the relevant quantum numbers of the fermions in the fundamental representation of the gauge group E _6 and showed that there are three possible ways of embedding electric charge in the generators of E _6. We have given the explicit form of the renormalization group equation for sin^2theta_{ rm W} and alpha_ {s} for the most usual chain of breaking E _6 down to SU(3)_ {c}otimes SU(2)_{L}otimes(1) _{Y}. The importance of the evolution of the coupling constant on the compactification is also stressed. We have analysed the successes and the limitations of Superstring theories and have mentioned the new frontiers in compactification.

Opto-electronic properties of P-doped nc-Si-QD/a-SiC:H thin films as foundation layer for all-Si solar cells in superstrate configuration

NASA Astrophysics Data System (ADS)

Kar, Debjit; Das, Debajyoti

2016-07-01

With the advent of nc-Si solar cells having improved stability, the efficient growth of nc-Si i-layer of the top cell of an efficient all-Si solar cell in the superstrate configuration prefers nc-Si n-layer as its substrate. Accordingly, a wide band gap and high conducting nc-Si alloy material is a basic requirement at the n-layer. Present investigation deals with the development of phosphorous doped n-type nanocrystalline silicon quantum dots embedded in hydrogenated amorphous silicon carbide (nc-Si-QD/a-SiC:H) hetero-structure films, wherein the optical band gap can be widened by the presence of Si-C bonds in the amorphous matrix and the embedded high density tiny nc-Si-QDs could provide high electrical conductivity, particularly in P-doped condition. The nc-Si-QDs simultaneously facilitate further widening of the optical band gap by virtue of the associated quantum confinement effect. A complete investigation has been made on the electrical transport phenomena involving charge transfer by tunneling and thermionic emission prevailing in n-type nc-Si-QD/a-SiC:H thin films. Their correlation with different phases of the specific heterostructure has been carried out for detailed understanding of the material, in order to improve its device applicability. The n-type nc-Si-QD/a-SiC:H films exhibit a thermally activated electrical transport above room temperature and multi-phonon hopping (MPH) below room temperature, involving defects in the amorphous phase and the grain-boundary region. The n-type nc-Si-QD/a-SiC:H films grown at ˜300 °C, demonstrating wide optical gap ˜1.86-1.96 eV and corresponding high electrical conductivity ˜4.5 × 10-1-1.4 × 10-2 S cm-1, deserve to be an effective foundation layer for the top nc-Si sub-cell of all-Si solar cells in n-i-p structure with superstrate configuration.

Improved performance of low cost CuInS2 superstrate-type solar cells using Zinc assisted spray pyrolysis processing

NASA Astrophysics Data System (ADS)

Cheshme Khavar, Amir Hossein; Mahjoub, Ali Reza; Taghavinia, Nima

2017-12-01

Superstrate configuration CuInS2 (CIS) solar cells are fabricated using a spray pyrolysis method. We avoided selenization process, cyanide etching and CdS buffer layer, to keep the process ‘green’. CIS layers are formed by spray pyrolysis of an aqueous precursor ink containing metal chloride salts and thiourea at 350 °C. We investigated the effect of intentional Zn doping on structural, morphological and photovoltaic response of the fabricated CIS films by dissolving ZnCl2 in aqueous precursor solution. At a zinc doping level ranging between 0.25 and 1.00 mol%, Zn doping is found to improve the CIS crystal growth and surface morphology of CIS films. Compared with the performance of the non-doped CIS cell, the Zn-doped CIS solar cell displayed a remarkable efficiency enhancement of 58-97% and the maximum enhancement was obtained at a Zn content of 0.5 mol%. The device structure consists of    and show promising PCE of 4.29 % without any anti-reflection coating. Over the course of 300 d under ambient condition, the fabricated device showed only 1% loss in efficiency.

Flint and the British Tradition of Relativity Theory

NASA Astrophysics Data System (ADS)

Beichler, James

2009-03-01

Most scientists and scholars are familiar with Sir Arthur Eddington's role in verifying General Relativity in 1919. A few less are aware of his work introducing the theory to the English scientific community. Still less know of Eddington's extensions of relativity theory, especially his attempts to develop a unified field theory. But very few scholars, historians or even physicists are aware of the important role played by other English scientists in the acceptance and development of relativity. In fact, H.T. Flint and his colleagues published more than thirty-five articles in peer reviewed journals in Britain over a period of four decades in an attempt to extend relativity to include electromagnetism and the quantum. Yet his work and that of his close associates is almost completely unknown today, in spite of the fact that he published a book describing his complete unified field theory in the 1960s, well before most quantum theorists even began thinking along the lines of unification. In a world filled with speculations about gravitons, superstrings, quantum loops and other unification models, Flint did it first, but his work has all but disappeared from the scientific consciousness. From Eddington to Flint, the English school of relativists has produced ardent supporters of relativity and numerous advances beyond the standard interpretations of general relativity.

The shadow world of superstring theories

NASA Technical Reports Server (NTRS)

Kolb, E. W.; Turner, M. S.; Seckel, D.

1985-01-01

Some possible astrophysical and cosmological implications of 'shadow matter', a form of matter which only interacts gravitationally with ordinary matter and which may or may not be identical in its properties to ordinary matter, are considered. The possible existence, amount, and location of shadow matter in the solar system are discussed, and the significance of shadow matter for primordial nucleosynthesis, macroscopic asymmetry, baryogenesis, double-bubble inflation, and asymmetric microphysics is addressed. Massive shadow states are discussed.

Exploring the spectrum of planar AdS4 /CFT3 at finite coupling

NASA Astrophysics Data System (ADS)

Bombardelli, Diego; Cavaglià, Andrea; Conti, Riccardo; Tateo, Roberto

2018-04-01

The Quantum Spectral Curve (QSC) equations for planar N=6 super-conformal Chern-Simons (SCS) are solved numerically at finite values of the coupling constant for states in the sl(2\\Big|1) sector. New weak coupling results for conformal dimensions of operators outside the sl(2) -like sector are obtained by adapting a recently proposed algorithm for the QSC perturbative solution. Besides being interesting in their own right, these perturbative results are necessary initial inputs for the numerical algorithm to converge on the correct solution. The non-perturbative numerical outcomes nicely interpolate between the weak coupling and the known semiclassical expansions, and novel strong coupling exact results are deduced from the numerics. Finally, the existence of contour crossing singularities in the TBA equations for the operator 20 is ruled out by our analysis. The results of this paper are an important test of the QSC formalism for this model, open the way to new quantitative studies and provide further evidence in favour of the conjectured weak/strong coupling duality between N=6 SCS and type IIA superstring theory on AdS4 × CP 3. Attached to the arXiv submission, a Mathematica implementation of the numerical method and ancillary files containing the numerical results are provided.

Foundations of Space and Time

NASA Astrophysics Data System (ADS)

Murugan, Jeff; Weltman, Amanda; Ellis, George F. R.

2012-07-01

1. The problem with quantum gravity Jeff Murugan, Amanda Weltman and George F. R. Eliis; 2. A dialogue on the nature of gravity Thanu Padmanabhan; 3. Effective theories and modifications of gravity Cliff Burgess; 4. The small scale structure of spacetime Steve Carlip; 5. Ultraviolet divergences in supersymmetric theories Kellog Stelle; 6. Cosmological quantum billiards Axel Kleinschmidt and Hermann Nicolai; 7. Progress in RNS string theory and pure spinors Dimitri Polyakov; 8. Recent trends in superstring phenomenology Massimo Bianchi; 9. Emergent spacetime Robert de Mello Koch and Jeff Murugan; 10. Loop quantum gravity Hanno Sahlmann; 11. Loop quantum gravity and cosmology Martin Bojowald; 12. The microscopic dynamics of quantum space as a group field theory Daniele Oriti; 13. Causal dynamical triangulations and the quest for quantum gravity Jan Ambjørn, J. Jurkiewicz and Renate Loll; 14. Proper time is stochastic time in 2D quantum gravity Jan Ambjorn, Renate Loll, Y. Watabiki, W. Westra and S. Zohren; 15. Logic is to the quantum as geometry is to gravity Rafael Sorkin; 16. Causal sets: discreteness without symmetry breaking Joe Henson; 17. The Big Bang, quantum gravity, and black-hole information loss Roger Penrose; Index.

Realizing three generations of the Standard Model fermions in the type IIB matrix model

NASA Astrophysics Data System (ADS)

Aoki, Hajime; Nishimura, Jun; Tsuchiya, Asato

2014-05-01

We discuss how the Standard Model particles appear from the type IIB matrix model, which is considered to be a nonperturbative formulation of superstring theory. In particular, we are concerned with a constructive definition of the theory, in which we start with finite- N matrices and take the large- N limit afterwards. In that case, it was pointed out recently that realizing chiral fermions in the model is more difficult than it had been thought from formal arguments at N = ∞ and that introduction of a matrix version of the warp factor is necessary. Based on this new insight, we show that two generations of the Standard Model fermions can be realized by considering a rather generic configuration of fuzzy S2 and fuzzy S2 × S2 in the extra dimensions. We also show that three generations can be obtained by squashing one of the S2's that appear in the configuration. Chiral fermions appear at the intersections of the fuzzy manifolds with nontrivial Yukawa couplings to the Higgs field, which can be calculated from the overlap of their wave functions.

Superstrings

ScienceCinema

Lincoln, Don

2018-01-16

The quest to find the ultimate building blocks of nature is one of the oldest in all of physics. While we are far from knowing the answer to that question, one intriguing proposed answer is that all matter is composed of tiny “strings.” The known particles are simply different vibrational patterns of these strings. In this video, Fermilab’s Dr. Don Lincoln explains this idea, using interesting and accessible examples of real-world vibrations.

Predicted and Totally Unexpected in the Energy Frontier Opened by LHC

NASA Astrophysics Data System (ADS)

Zichichi, Antonino

2011-01-01

Opening lectures. Sid Coleman and Erice / A. Zichichi. Remembering Sidney Coleman / G.'t Hooft -- Predicted signals at LHC. From extra-dimensions: Multiple branes scenarios and their contenders / I. Antoniadis. Predicted signals at the LHC from technicolor / A. Martin. The one-parameter model at LHC / J. Maxin, E. Mayes and D. V. Nanopoulos. How supercritical string cosmology affects LHC / D. V. Nanopoulos. High scale physics connection to LHC data / P. Nath. Predicted signatures at the LHC from U(I) extensions of the standard model / P. Nath -- Hot theoretical topics. Progress on the ultraviolet finiteness of supergravity / Z. Bern. Status of supersymmetry: Foundations and applications / S. Ferrara and A. Marrani. Quantum gravity from dynamical triangulation / R. Loll. Status of superstring and M-theory / J. H. Schwarz. Some effects of instantons in QCD / G.'t Hooft. Crystalline gravity / G.'t Hooft -- QCD problems. Strongly coupled gauge theories / R. Kenway. Strongly interacting matter at high energy density / L. McLerran. Seminars on specialized topics. The nature and the mass of neutrinos. Majorana vs. Dirac / A. Bettini. The anomalous spin distributions in the nucleon / A. Deshpande. Results from PHENIX at RHIC / M. J. Tannenbaum -- Highlights from laboratories. Highlights from RHIC / Y. Akiba. News from the Gran Sasso Underground Laboratory / E. Coccia. Highlights from TRIUMF / N. S. Lockyer. Highlights from Superkamiokande / M. Koshiba. Highlights from Fermilab / P. J. Oddone. Highlights from IHEP / Y. Wang -- Special sessions for new talents. Fake supergravity and black hole evolution / A. Gnecchi. Track-based improvement in the jet transverse momentum resolution for ATLAS / Z. Marshall. Searches for supersymmetric dark matter with XENON / K. Ni. Running of Newton's constant and quantum gravitational effects / D. Reeb.

Mode-independent attenuation in evanescent-field sensors

NASA Astrophysics Data System (ADS)

Gnewuch, Harald; Renner, Hagen

1995-03-01

Generally, the total power attenuation in multimode evanescent-field sensor waveguides is nonproportional to the bulk absorbance because the modal attenuation constants differ. Hence a direct measurement is difficult and is additionally aggravated because the waveguide absorbance is highly sensitive to the specific launching conditions at the waveguide input. A general asymptotic formula for the modal power attenuation in strongly asymmetric inhomogeneous planar waveguides with arbitrarily distributed weak absorption in the low-index superstrate is derived. Explicit expressions for typical refractive-index profiles are given. Except when very close to the cutoff, the predicted asymptotic attenuation behavior agrees well with exact calculations. The ratio of TM versus TE absorption has been derived to be (2 - n0 2/nf2 ) for arbitrary profiles. Waveguides with a linear refractive-index profile show mode-independent attenuation coefficients within each polarization. Further, the asymptotic sensitivity is independent of the wavelength, so that it should be possible to directly measure the spectral variation of the bulk absorption. The mode independence of the attenuation has been verified experimentally for a second-order polynomial profile, which is close to a linear refractive-index distribution. In contrast, the attenuation in the step-profile waveguide has been found to depend strongly on the mode number, as predicted by theory. A strong spread of the modal attenuation coefficients is also predicted for the parabolic-profile waveguide sensor.

Geometric structures of super-(Diff(S/sup 1/)/S/sup 1/)*

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmidke, W.B.; Vokos, S.P.

Superconformal invariance is of central importance to a perturbative and non-perturbative formulation of stringy theory. The group that describes the invariances of the superstring is the super-Virasoro group, Super-Diff(S/sup 1/). The super-reparameterizations of the circle that leave a point fixed compose the quotient space Super-(Diff(S/sup 1/)/S/sup 1/). We investigate the holomorphic geometry of this infinite-dimensional Kaehler supermanifold and calculate its curvature. copyright 1989 Academic Press, Inc.

Consequences of an Abelian family symmetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramond, P.

1996-01-01

The addition of an Abelian family symmetry to the Minimal Super-symmetric Standard Model reproduces the observed hierarchies of quark and lepton masses and quark mixing angles, only if it is anomalous. Green-Schwarz compensation of its anomalies requires the electroweak mixing angle to be sin{sup 2}{theta}{sub {omega}} = 3/8 at the string scale, without any assumed GUT structure, suggesting a superstring origin for the standard model. The analysis is extended to neutrino masses and the lepton mixing matrix.

Investigation of proposed process sequence for the array automated assembly task, phases 1 and 2

NASA Technical Reports Server (NTRS)

Mardesich, N.; Garcia, A.; Eskenas, K.

1980-01-01

Progress was made on the process sequence for module fabrication. A shift from bonding with a conformal coating to laminating with ethylene vinyl acetate and a glass superstrate is recommended for further module fabrication. The processes that were retained for the selected process sequence, spin-on diffusion, print and fire aluminum p+ back, clean, print and fire silver front contact and apply tin pad to aluminum back, were evaluated for their cost contribution.

Analytical solution for haze values of aluminium-induced texture (AIT) glass superstrates for a-Si:H solar cells.

PubMed

Sahraei, Nasim; Forberich, Karen; Venkataraj, Selvaraj; Aberle, Armin G; Peters, Marius

2014-01-13

Light scattering at randomly textured interfaces is essential to improve the absorption of thin-film silicon solar cells. Aluminium-induced texture (AIT) glass provides suitable scattering for amorphous silicon (a-Si:H) solar cells. The scattering properties of textured surfaces are usually characterised by two properties: the angularly resolved intensity distribution and the haze. However, we find that the commonly used haze equations cannot accurately describe the experimentally observed spectral dependence of the haze of AIT glass. This is particularly the case for surface morphologies with a large rms roughness and small lateral feature sizes. In this paper we present an improved method for haze calculation, based on the power spectral density (PSD) function of the randomly textured surface. To better reproduce the measured haze characteristics, we suggest two improvements: i) inclusion of the average lateral feature size of the textured surface into the haze calculation, and ii) considering the opening angle of the haze measurement. We show that with these two improvements an accurate prediction of the haze of AIT glass is possible. Furthermore, we use the new equation to define optimum morphology parameters for AIT glass to be used for a-Si:H solar cell applications. The autocorrelation length is identified as the critical parameter. For the investigated a-Si:H solar cells, the optimum autocorrelation length is shown to be 320 nm.

Mrst '96: Current Ideas in Theoretical Physics - Proceedings of the Eighteenth Annual Montréal-Rochester-Syracuse-Toronto Meeting

NASA Astrophysics Data System (ADS)

O'Donnell, Patrick J.; Smith, Brian Hendee

1996-11-01

The Table of Contents for the full book PDF is as follows: * Preface * Roberto Mendel, An Appreciaton * The Infamous Coulomb Gauge * Renormalized Path Integral in Quantum Mechanics * New Analysis of the Divergence of Perturbation Theory * The Last of the Soluble Two Dimensional Field Theories? * Rb and Heavy Quark Mixing * Rb Problem: Loop Contributions and Supersymmetry * QCD Radiative Effects in Inclusive Hadronic B Decays * CP-Violating Dipole Moments of Quarks in the Kobayashi-Maskawa Model * Hints of Dynamical Symmetry Breaking? * Pi Pi Scattering in an Effective Chiral Lagrangian * Pion-Resonance Parameters from QCD Sum Rules * Higgs Theorem, Effective Action, and its Gauge Invariance * SUSY and the Decay H_2^0 to gg * Effective Higgs-to-Light Quark Coupling Induced by Heavy Quark Loops * Heavy Charged Lepton Production in Superstring Inspired E6 Models * The Elastic Properties of a Flat Crystalline Membrane * Gauge Dependence of Topological Observables in Chern-Simons Theory * Entanglement Entropy From Edge States * A Simple General Treatment of Flavor Oscillations * From Schrödinger to Maupertuis: Least Action Principles from Quantum Mechanics * The Matrix Method for Multi-Loop Feynman Integrals * Simplification in QCD and Electroweak Calculations * Programme * List of Participants

Near-ideal optical metamaterial absorbers with super-octave bandwidth.

PubMed

Bossard, Jeremy A; Lin, Lan; Yun, Seokho; Liu, Liu; Werner, Douglas H; Mayer, Theresa S

2014-02-25

Nanostructured optical coatings with tailored spectral absorption properties are of interest for a wide range of applications such as spectroscopy, emissivity control, and solar energy harvesting. Optical metamaterial absorbers have been demonstrated with a variety of customized single band, multiple band, polarization, and angular configurations. However, metamaterials that provide near unity absorptivity with super-octave bandwidth over a specified optical wavelength range have not yet been demonstrated experimentally. Here, we show a broadband, polarization-insensitive metamaterial with greater than 98% measured average absorptivity that is maintained over a wide ± 45° field-of-view for mid-infrared wavelengths between 1.77 and 4.81 μm. The nearly ideal absorption is realized by using a genetic algorithm to identify the geometry of a single-layer metal nanostructure array that excites multiple overlapping electric resonances with high optical loss across greater than an octave bandwidth. The response is optimized by substituting palladium for gold to increase the infrared metallic loss and by introducing a dielectric superstrate to suppress reflection over the entire band. This demonstration advances the state-of-the-art in high-performance broadband metamaterial absorbers that can be reliably fabricated using a single patterned layer of metal nanostructures.

A class of exact classical solutions to string theory.

PubMed

Coley, A A

2002-12-31

We show that the recently obtained class of spacetimes for which all of the scalar curvature invariants vanish (which can be regarded as generalizations of pp-wave spacetimes) are exact solutions in string theory to all perturbative orders in the string tension scale. As a result the spectrum of the theory can be explicitly obtained, and these spacetimes are expected to provide some hints for the study of superstrings on more general backgrounds. Since these Lorentzian spacetimes suffer no quantum corrections to all loop orders they may also offer insights into quantum gravity.

Matrix theory interpretation of discrete light cone quantization string worldsheets

PubMed

Grignani; Orland; Paniak; Semenoff

2000-10-16

We study the null compactification of type-IIA string perturbation theory at finite temperature. We prove a theorem about Riemann surfaces establishing that the moduli spaces of infinite-momentum-frame superstring worldsheets are identical to those of branched-cover instantons in the matrix-string model conjectured to describe M theory. This means that the identification of string degrees of freedom in the matrix model proposed by Dijkgraaf, Verlinde, and Verlinde is correct and that its natural generalization produces the moduli space of Riemann surfaces at all orders in the genus expansion.

Exploring the Invisible Universe: From Black Holes to Superstrings

NASA Astrophysics Data System (ADS)

Baaquie, Belal E.; Willeboordse, Frederick H.

2015-03-01

The book is written for a broad scientific audience with an interest in the leading theories about the Universe. The focus is on the physical Universe, and the laws of Physics are taken to be the guiding light in all our analysis. Starting from first principles and using self-evident reasoning, all the fundamental ideas that are employed in exploring the hidden and invisible realms of the Universe are shown to arise quite naturally, once one adopts the outlook that has come to light with the advances in Physics...

Cosmological backgrounds of gravitational waves and eLISA/NGO: phase transitions, cosmic strings and other sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Binétruy, Pierre; Dufaux, Jean-François; Bohé, Alejandro

We review several cosmological backgrounds of gravitational waves accessible to direct-detection experiments, with a special emphasis on those backgrounds due to first-order phase transitions and networks of cosmic (super-)strings. For these two particular sources, we revisit in detail the computation of the gravitational wave background and improve the results of previous works in the literature. We apply our results to identify the scientific potential of the NGO/eLISA mission of ESA regarding the detectability of cosmological backgrounds.

Planar metamaterial based on hybridization for directive emission.

PubMed

Ourir, Abdelwaheb; Abdeddaim, Redha; de Rosny, Julien

2012-07-30

We present the first experimental demonstration of a high-directivity using a mu and epsilon near zero (MENZ) metamaterial. We use the hybridization principles to design a planar MENZ structure based on the fishnet unit cell. Resonant mode engineering achieves an effective permittivity and permeability that approaches zeros around 10.5 GHz simultaneously. We use this metamaterial as a superstrate of a microstrip patch antenna. We show that the directivity of the antenna is effectively enhanced compared to that of the patch antenna alone at the desired frequency.

High sensitivity optical biosensor based on polymer materials and using the Vernier effect.

PubMed

Azuelos, Paul; Girault, Pauline; Lorrain, Nathalie; Poffo, Luiz; Guendouz, Mohammed; Thual, Monique; Lemaître, Jonathan; Pirasteh, Parastesh; Hardy, Isabelle; Charrier, Joël

2017-11-27

We demonstrate the fabrication of a Vernier effect SU8/PMATRIFE polymer optical biosensor with high homogeneous sensitivity using a standard photolithography process. The sensor is based on one micro-resonator embedded on each arm of a Mach-Zehnder interferometer. Measurements are based on the refractive index variation of the optical waveguide superstrate with different concentrations of glucose solutions. The sensitivity of the sensor has been measured as 17558 nm/RIU and the limit of detection has been estimated to 1.1.10 -6 RIU.

Basic Research in Electronics (JSEP) Joint Services Electronics Program.

DTIC Science & Technology

1987-12-31

poiNU362Z~ fi5v WALu i~n v.j WSW)F fulmB JELECTROUICS FROMM. (U) POLYTECHNIC UII FAW1406lL WY MEKR RESERCH INST At A OLINEN ET ft. 31 DEC S? UmC...range, as discussed in section 3. The fifth topic relates to a superstrate-substrate structure that permits a simple printed-circuit antenna to radiate...Antennas Loaded by Periodic Metal Strips. In last year’s Annual Report we presented a simple and accurate transverse equivalent network for the class

Open-field behavior of house mice selectively bred for high voluntary wheel-running.

PubMed

Bronikowski, A M; Carter, P A; Swallow, J G; Girard, I A; Rhodes, J S; Garland, T

2001-05-01

Open-field behavioral assays are commonly used to test both locomotor activity and emotionality in rodents. We performed open-field tests on house mice (Mus domesticus) from four replicate lines genetically selected for high voluntary wheel-running for 22 generations and from four replicate random-bred control lines. Individual mice were recorded by video camera for 3 min in a 1-m2 open-field arena on 2 consecutive days. Mice from selected lines showed no statistical differences from control mice with respect to distance traveled, defecation, time spent in the interior, or average distance from the center of the arena during the trial. Thus, we found little evidence that open-field behavior, as traditionally defined, is genetically correlated with wheel-running behavior. This result is a useful converse test of classical studies that report no increased wheel-running in mice selected for increased open-field activity. However, mice from selected lines turned less in their travel paths than did control-line mice, and females from selected lines had slower travel times (longer latencies) to reach the wall. We discuss these results in the context of the historical open-field test and newly defined measures of open-field activity.

Behavioral and locomotor measurements using an open field activity monitoring system for skeletal muscle diseases.

PubMed

Tatem, Kathleen S; Quinn, James L; Phadke, Aditi; Yu, Qing; Gordish-Dressman, Heather; Nagaraju, Kanneboyina

2014-09-29

The open field activity monitoring system comprehensively assesses locomotor and behavioral activity levels of mice. It is a useful tool for assessing locomotive impairment in animal models of neuromuscular disease and efficacy of therapeutic drugs that may improve locomotion and/or muscle function. The open field activity measurement provides a different measure than muscle strength, which is commonly assessed by grip strength measurements. It can also show how drugs may affect other body systems as well when used with additional outcome measures. In addition, measures such as total distance traveled mirror the 6 min walk test, a clinical trial outcome measure. However, open field activity monitoring is also associated with significant challenges: Open field activity measurements vary according to animal strain, age, sex, and circadian rhythm. In addition, room temperature, humidity, lighting, noise, and even odor can affect assessment outcomes. Overall, this manuscript provides a well-tested and standardized open field activity SOP for preclinical trials in animal models of neuromuscular diseases. We provide a discussion of important considerations, typical results, data analysis, and detail the strengths and weaknesses of open field testing. In addition, we provide recommendations for optimal study design when using open field activity in a preclinical trial.

Observations of a Small Interplanetary Magnetic Flux Rope Opening by Interchange Reconnection

NASA Astrophysics Data System (ADS)

Wang, J. M.; Feng, H. Q.; Zhao, G. Q.

2018-01-01

Interchange reconnection, specifically magnetic reconnection between open magnetic fields and closed magnetic flux ropes, plays a major role in the heliospheric magnetic flux budget. It is generally accepted that closed magnetic field lines of interplanetary magnetic flux ropes (IMFRs) can gradually open through reconnection between one of its legs and other open field lines until no closed field lines are left to contribute flux to the heliosphere. In this paper, we report an IMFR associated with a magnetic reconnection exhaust, whereby its closed field lines were opening by a magnetic reconnection event near 1 au. The reconnection exhaust and the following IMFR were observed on 2002 February 2 by both the Wind and ACE spacecraft. Observations on counterstreaming suprathermal electrons revealed that most magnetic field lines of the IMFR were closed, especially those after the front boundary of the IMFR, with both ends connected to the Sun. The unidirectional suprathermal electron strahls before the exhaust manifested the magnetic field lines observed before the exhaust was open. These observations provide direct evidence that closed field lines of IMFRs can be opened by interchange reconnection in interplanetary space. This is the first report of the closed field lines of IMFRs being opened by interchange reconnection in interplanetary space. This type of interplanetary interchange reconnection may pose important implications for balancing the heliospheric flux budget.

Effects of rat sex differences and lighting on locomotor exploration of a circular open field with free-standing central corners and without peripheral walls.

PubMed

Alstott, Jeff; Timberlake, William

2009-01-23

A typical open field consists of a square enclosure, bounded by four straight walls joined by identical corners. For decades behavioral researchers have used the open center and more sheltered perimeter of such fields to examine the effects of drugs, sex differences, and illumination on the behavioral expression of fear and anxiety. The present study "reversed" the relative security of the center and periphery of a circular field to re-examine the functional relation of open field behavior to experience, sex differences and lighting. Across six daily exposures, males in both the light and dark rapidly increased their preference for the center. Females in the light developed a similar pattern, though more slowly; females in the dark continued to spend the great majority of their time in the open periphery, including the edge of the field. The behavior of all groups, but especially the dark females, strongly supports the continued importance of environmental assessment in open field behavior.

[Towards an unified theory of the universe basic forces ("the everything theory")].

PubMed

Aguilar Peris, José

2004-01-01

Numerous efforts have been made in order to unify all the basic forces in nature. In 1967 the fusion of electromagnetic and weak forces was obtained and in 1973 a theoretical bridge between the electroweak and the strong forces have been constructed. This theory is waiting for experimental proofs in the CERN large hadron collider. The last stage would be "the everything theory", which includes the gravitational force. Only the so called superstring theory is a good candidate to overcome the incompatibility of the quantum mechanics and the general relativity, but this theory is not already achieved.

D=10 Chiral Tensionless Super p-BRANES

NASA Astrophysics Data System (ADS)

Bozhilov, P.

We consider a model for tensionless (null) super-p-branes with N chiral supersymmetries in ten-dimensional flat space-time. After establishing the symmetries of the action, we give the general solution of the classical equations of motion in a particular gauge. In the case of a null superstring (p=1) we find the general solution in an arbitrary gauge. Then, using a harmonic superspace approach, the initial algebra of first- and second-class constraints is converted into an algebra of Lorentz-covariant, BFV-irreducible, first-class constraints only. The corresponding BRST charge is as for a first rank dynamical system.

String inspired brane world cosmology.

PubMed

Germani, Cristiano; Sopuerta, Carlos F

2002-06-10

We consider brane world scenarios including the leading correction to the Einstein-Hilbert action suggested by superstring theory, the Gauss-Bonnet term. We obtain and study the complete set of equations governing the cosmological dynamics. We find they have the same form as those in Randall-Sundrum scenarios but with time-varying four-dimensional gravitational and cosmological constants. By studying the bulk geometry we show that this variation is produced by bulk curvature terms parametrized by the mass of a black hole. Finally, we show there is a coupling between these curvature terms and matter that can be relevant for early universe cosmology.

Thermal and optical performance of encapsulation systems for flat-plate photovoltaic modules

NASA Technical Reports Server (NTRS)

Minning, C. P.; Coakley, J. F.; Perrygo, C. M.; Garcia, A., III; Cuddihy, E. F.

1981-01-01

The electrical power output from a photovoltaic module is strongly influenced by the thermal and optical characteristics of the module encapsulation system. Described are the methodology and computer model for performing fast and accurate thermal and optical evaluations of different encapsulation systems. The computer model is used to evaluate cell temperature, solar energy transmittance through the encapsulation system, and electric power output for operation in a terrestrial environment. Extensive results are presented for both superstrate-module and substrate-module design schemes which include different types of silicon cell materials, pottants, and antireflection coatings.

Probing New Physics with Jets at the LHC

ScienceCinema

Harris, Robert

2017-12-09

The Large Hadron Collider at CERN has the potential to make a major discovery as early as 2008 from simple measurements of events with two high energy jets. This talk will present the jet trigger and analysis plans of the CMS collaboration, which were produced at the LHC Physics Center at Fermilab. Plans to search the two jet channel for generic signals of new particles and forces will be discussed. I will present the anticipated sensitivity of the CMS experiment to a variety of models of new physics, including quark compositeness, technicolor, superstrings, extra dimensions and grand unification.

Device Engineering Towards Improved Tin Sulfide Solar Cell Performance and Performance Reproducibility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steinmann, Vera; Chakraborty, Rupak; Rekemeyer, Paul

2016-11-21

As novel absorber materials are developed and screened for their photovoltaic (PV) properties, the challenge remains to rapidly test promising candidates in high-performing PV devices. There is a need to engineer new compatible device architectures, including the development of novel transparent conductive oxides and buffer layers. Here, we consider the two approaches of a substrate-style and a superstrate-style device architecture for novel thin-film solar cells. We use tin sulfide as a test absorber material. Upon device engineering, we demonstrate new approaches to improve device performance and performance reproducibility.

Quasi-optical grids with thin rectangular patch/aperture elements

NASA Technical Reports Server (NTRS)

Wu, Te-Kao

1993-01-01

Theoretical analysis is presented for an efficient and accurate performance evaluation of quasi-optical grids comprised of thin rectangular patch/aperture elements with/without a dielectric substrate/superstrate. The convergence rate of this efficient technique is improved by an order of magnitude with the approximate edge conditions incorporated in the basis functions of the integral equation solution. Also presented are the interesting applications of this efficient analytical technique to the design and performance evaluation of the coupling grids and beam splitters in the optical systems as well as thermal protection sunshields used in the communication systems of satellites and spacecrafts.

Evidence in Magnetic Clouds for Systematic Open Flux Transport on the Sun

NASA Technical Reports Server (NTRS)

Crooker, N. U.; Kahler, S. W.; Gosling, J. T.; Lepping, R. P.

2008-01-01

Most magnetic clouds encountered by spacecraft at 1 AU display a mix of unidirectional suprathermal electrons signaling open field lines and counterstreaming electrons signaling loops connected to the Sun at both ends. Assuming the open fields were originally loops that underwent interchange reconnection with open fields at the Sun, we determine the sense of connectedness of the open fields found in 72 of 97 magnetic clouds identified by the Wind spacecraft in order to obtain information on the location and sense of the reconnection and resulting flux transport at the Sun. The true polarity of the open fields in each magnetic cloud was determined from the direction of the suprathermal electron flow relative to the magnetic field direction. Results indicate that the polarity of all open fields within a given magnetic cloud is the same 89% of the time, implying that interchange reconnection at the Sun most often occurs in only one leg of a flux rope loop, thus transporting open flux in a single direction, from a coronal hole near that leg to the foot point of the opposite leg. This pattern is consistent with the view that interchange reconnection in coronal mass ejections systematically transports an amount of open flux sufficient to reverse the polarity of the heliospheric field through the course of the solar cycle. Using the same electron data, we also find that the fields encountered in magnetic clouds are only a third as likely to be locally inverted as not. While one might expect inversions to be equally as common as not in flux rope coils, consideration of the geometry of spacecraft trajectories relative to the modeled magnetic cloud axes leads us to conclude that the result is reasonable.

Energy buildup in sheared force-free magnetic fields

NASA Technical Reports Server (NTRS)

Wolfson, Richard; Low, Boon C.

1992-01-01

Photospheric displacement of the footpoints of solar magnetic field lines results in shearing and twisting of the field, and consequently in the buildup of electric currents and magnetic free energy in the corona. The sudden release of this free energy may be the origin of eruptive events like coronal mass ejections, prominence eruptions, and flares. An important question is whether such an energy release may be accompanied by the opening of magnetic field lines that were previously closed, for such open field lines can provide a route for matter frozen into the field to escape the sun altogether. This paper presents the results of numerical calculations showing that opening of the magnetic field is permitted energetically, in that it is possible to build up more free energy in a sheared, closed, force-free magnetic field than is in a related magnetic configuration having both closed and open field lines. Whether or not the closed force-free field attains enough energy to become partially open depends on the form of the shear profile; the results presented compare the energy buildup for different shear profiles. Implications for solar activity are discussed briefly.

Characteristics of Ambient Black Carbon Mass and Size-Resolved Particle Number Concentrations during Corn Straw Open-Field Burning Episode Observations at a Rural Site in Southern Taiwan.

PubMed

Cheng, Yu-Hsiang; Yang, Li-Sing

2016-07-08

Information on the effect of open-field burning of agricultural residues on ambient black carbon (BC) mass and size-resolved particle number concentrations is scarce. In this study, to understand the effect of such open-field burning on short-term air quality, real-time variations of the BC mass and size-resolved particle number concentrations were monitored before and during a corn straw open-field burning episode at a rural site. Correlations between the BC mass and size-resolved particle number concentrations during the episode were investigated. Moreover, the particle number size distribution and absorption Ångström exponent were determined for obtaining the characteristics of aerosol emissions from the corn straw open-field burning. The results can be used to address public health concerns and as a reference for managing similar episodes of open-field burning of agricultural residues.

Observations of disconnection of open coronal magnetic structures

NASA Technical Reports Server (NTRS)

Mccomas, D. J.; Phillips, J. L.; Hundhausen, A. J.; Burkepile, J. T.

1991-01-01

The solar maximum mission coronagraph/polarimeter observations are surveyed for evidence of magnetic disconnection of previously open magnetic structures and several sequences of images consistent with this interpretation are identified. Such disconnection occurs when open field lines above helmet streamers reconnect, in contrast to previously suggested disconnections of CMEs into closed plasmoids. In this paper a clear example of open field disconnection is shown in detail. The event, on June 27, 1988, is preceded by compression of a preexisting helmet streamer and the open coronal field around it. The compressed helmet streamer and surrounding open field region detach in a large U-shaped structure which subsequently accelerates outward from the sun. The observed sequence of events is consistent with reconnection across the heliospheric current sheet and the creation of a detached U-shaped magnetic structure. Unlike CMEs, which may open new magnetic flux into interplanetary space, this process could serve to close off previously open flux, perhaps helping to maintain the roughly constant amount of open magnetic flux observed in interplanetary space.

Interchange Reconnection and Coronal Hole Dynamics

NASA Technical Reports Server (NTRS)

Edmondson, J. K.; Antiochos, S. K.; DeVore, C. R.; Lynch, B. J.; Zurbuchen, T. H.

2011-01-01

We investigate the effect of magnetic reconnection between open and closed field, (often referred to as "interchange" reconnection), on the dynamics and topology of coronal hole boundaries. The most important and most prevalent 3D topology of the interchange process is that of a small-scale bipolar magnetic field interacting with a large-scale background field. We determine the evolution of such a magnetic topology by numerical solution of the fully 3D MHD equations in spherical coordinates. First, we calculate the evolution of a small-scale bipole that initially is completely inside an open field region and then is driven across a coronal hole boundary by photospheric motions. Next the reverse situation is calculated in which the bipole is initially inside the closed region and driven toward the coronal hole boundary. In both cases we find that the stress imparted by the photospheric motions results in deformation of the separatrix surface between the closed field of the bipole and the background field, leading to rapid current sheet formation and to efficient reconnection. When the bipole is inside the open field region, the reconnection is of the interchange type in that it exchanges open and closed field. We examine, in detail, the topology of the field as the bipole moves across the coronal hole boundary, and find that the field remains well-connected throughout this process. Our results imply that open flux cannot penetrate deeply into the closed field region below a helmet streamer and, hence, support the quasi-steady models in which open and closed flux remain topologically distinct. Our results also support the uniqueness hypothesis for open field regions as postulated by Antiochos et al. We discuss the implications of this work for coronal observations. Subject Headings: Sun: corona Sun: magnetic fields Sun: reconnection Sun: coronal hole

Proactive interference of open field on consummatory successive negative contrast.

PubMed

Justel, Nadia; Pautassi, Ricardo; Mustaca, Alba

2014-03-01

Reactivity to a reward is affected by prior experience with the different reinforcer values of that reward, a phenomenon known as incentive relativity, which can be studied using the consummatory succesive negative contrast (cSNC) paradigm, in which the performance of animals that receive a 4 % sucrose solution after trials on which they were exposed to 32 % sucrose is compared with that of subjects that always receive the 4 % sucrose solution. The exploration of a novel open field can enhance or block the acquisition of associative and nonassociative memories. The effect of open field on cSNC has not yet been explored. The main result of the present study was that open-field exposure significantly modified the expression of cSNC. Exposure to an open field 1 h but not immediately before the downshift interfered with the expression of cSNC. These animals drank more of the downshifted reward than did controls that were not exposed to the apparatus, and this behavior persisted for up to three recovery trials. This phenomenon was observed even when the animals were given a more protracted preshift phase and when the discrepancy between the preshift and shift incentive values of sucrose were increased. An open field also interfered with incentive downshift when open-field exposure occurred 6 h before the downshift, and repeated exposure to the apparatus did not deteriorate this effect. The present study adds to a growing body of literature that indicates that open-field exploration can interfere with memory formation.

Induced Voltage in an Open Wire

NASA Astrophysics Data System (ADS)

Morawetz, K.; Gilbert, M.; Trupp, A.

2017-07-01

A puzzle arising from Faraday's law has been considered and solved concerning the question which voltage will be induced in an open wire with a time-varying homogeneous magnetic field. In contrast to closed wires where the voltage is determined by the time variance of the magnetic field and the enclosed area, in an open wire we have to integrate the electric field along the wire. It is found that the longitudinal electric field with respect to the wave vector contributes with 1/3 and the transverse field with 2/3 to the induced voltage. In order to find the electric fields the sources of the magnetic fields are necessary to know. The representation of a spatially homogeneous and time-varying magnetic field implies unavoidably a certain symmetry point or symmetry line which depend on the geometry of the source. As a consequence the induced voltage of an open wire is found to be the area covered with respect to this symmetry line or point perpendicular to the magnetic field. This in turn allows to find the symmetry points of a magnetic field source by measuring the voltage of an open wire placed with different angles in the magnetic field. We present exactly solvable models of the Maxwell equations for a symmetry point and for a symmetry line, respectively. The results are applicable to open circuit problems like corrosion and for astrophysical applications.

Can Polar Fields Explain Missing Open Flux?

NASA Astrophysics Data System (ADS)

Linker, J.; Downs, C.; Caplan, R. M.; Riley, P.; Mikic, Z.; Lionello, R.

2017-12-01

The "open" magnetic field is the portion of the Sun's magnetic field that extends out into the heliosphere and becomes the interplanetary magnetic field (IMF). Both the IMF and the Sun's magnetic field in the photosphere have been measured for many years. In the standard paradigm of coronal structure, the open magnetic field originates primarily in coronal holes. The regions that are magnetically closed trap the coronal plasma and give rise to the streamer belt. This basic picture is qualitatively reproduced by models of coronal structure using photospheric magnetic fields as input. If this paradigm is correct, there are two primary observational constraints on the models: (1) The open field regions in the model should approximately correspond to coronal holes observed in emission, and (2) the magnitude of the open magnetic flux in the model should match that inferred from in situ spacecraft measurements. Linker et al. (2017, ApJ, submitted) investigated the July 2010 time period for a range of observatory maps and both PFSS and MHD models. We found that all of the model/map combinations underestimated the interplanetary magnetic flux, unless the modeled open field regions were larger than observed coronal holes. An estimate of the open magnetic flux made entirely from solar observations (combining detected coronal hole boundaries with observatory synoptic magnetic maps) also underestimated the interplanetary magnetic flux. The magnetic field near the Sun's poles is poorly observed and may not be well represented in observatory maps. In this paper, we explore whether an underestimate of the polar magnetic flux during this time period could account for the overall underestimate of open magnetic flux. Research supported by NASA, AFOSR, and NSF.

Topological defects in open string field theory

NASA Astrophysics Data System (ADS)

Kojita, Toshiko; Maccaferri, Carlo; Masuda, Toru; Schnabl, Martin

2018-04-01

We show how conformal field theory topological defects can relate solutions of open string field theory for different boundary conditions. To this end we generalize the results of Graham and Watts to include the action of defects on boundary condition changing fields. Special care is devoted to the general case when nontrivial multiplicities arise upon defect action. Surprisingly the fusion algebra of defects is realized on open string fields only up to a (star algebra) isomorphism.

Magic Universe - The Oxford Guide to Modern Science

NASA Astrophysics Data System (ADS)

Calder, Nigel

2003-11-01

As a prolific author, BBC commentator, and magazine editor, Nigel Calder has spent a lifetime spotting and explaining the big discoveries in all branches of science. In Magic Universe , he draws on his vast experience to offer readers a lively, far-reaching look at modern science in all its glory, shedding light on the latest ideas in physics, biology, chemistry, medicine, astronomy, and many other fields. What is truly magical about Magic Universe is Calder's incredible breadth. Migrating birds, light sensors in the human eye, black holes, antimatter, buckyballs and nanotubes--with exhilarating sweep, Calder can range from the strings of a piano to the superstrings of modern physics, from Pythagoras's theory of musical pitch to the most recent ideas about atoms and gravity and a ten-dimensional universe--all in one essay. The great virtue of this wide-ranging style--besides its liveliness and versatility--is that it allows Calder to illuminate how the modern sciences intermingle and cross-fertilize one another. Indeed, whether discussing astronauts or handedness or dinosaurs, Calder manages to tease out hidden connections between disparate fields of study. What is most wondrous about the "magic universe" is that one can begin with stellar dust and finish with life itself. Drawing on interviews with more than 200 researchers, from graduate students to Nobel prize-winners, Magic Universe takes us on a high-spirited tour through the halls of science, one that will enthrall everyone interested in science, whether a young researcher in a high-tech lab or an amateur buff sitting in the comfort of an armchair.

Controlling the physical parameters of crystalline CIGS nanowires for use in superstrate configuration using vapor phase epitaxy

NASA Astrophysics Data System (ADS)

Lee, Dongjin; Jeon, H. C.; Kang, T. W.; Kumar, Sunil

2018-03-01

Indium tin oxide (ITO) is a suitable candidate for smart windows and bifacial semi-transparent solar cell applications. In this study, highly crystalline CuInGaSe2 (CIGS) nanowires were successfully grown by horizontal-type vapor phase epitaxy on an ITO substrate. Length, diameter, and density of the nanowires were studied by varying the growth temperature (500, 520, and 560 °C), time (3.5, 6.5, and 9.5 h), and type of catalyst (In, Au, and Ga). Length, diameter, and density of the nanowires were found to be highly dependent on the growth conditions. At an optimized growth period and temperature of 3.5 h and 520 °C, respectively, the length and diameter of the nanowires were found to increase when grown in a catalyst-free environment. However, the density of the nanowires was found to be higher while using a catalyst during growth. Even in a catalyst-free environment, an Indium cluster formed at the bottom of the nanowires. The source of these nanowires is believed to be Indium from the ITO substrate which was observed in the EDS measurement. TEM-based EDS and line EDS indicated that the nanowires are made up of CIGS material with a very low Gallium content. XRD measurements also show the appearance of wurtzite CIS nanowires grown on ITO in addition to the chalcopyrite phase. PL spectroscopy was done to see the near-band-edge emission for finding band-to-band optical transition in this material. Optical response of the CIGS nanowire network was also studied to see the photovoltaic effect. This work creates opportunities for making real solar cell devices in superstrate configuration.

Modern Quantum Field Theory II - Proceeeings of the International Colloquium

NASA Astrophysics Data System (ADS)

Das, S. R.; Mandal, G.; Mukhi, S.; Wadia, S. R.

1995-08-01

The Table of Contents for the book is as follows: * Foreword * 1. Black Holes and Quantum Gravity * Quantum Black Holes and the Problem of Time * Black Hole Entropy and the Semiclassical Approximation * Entropy and Information Loss in Two Dimensions * Strings on a Cone and Black Hole Entropy (Abstract) * Boundary Dynamics, Black Holes and Spacetime Fluctuations in Dilation Gravity (Abstract) * Pair Creation of Black Holes (Abstract) * A Brief View of 2-Dim. String Theory and Black Holes (Abstract) * 2. String Theory * Non-Abelian Duality in WZW Models * Operators and Correlation Functions in c ≤ 1 String Theory * New Symmetries in String Theory * A Look at the Discretized Superstring Using Random Matrices * The Nested BRST Structure of Wn-Symmetries * Landau-Ginzburg Model for a Critical Topological String (Abstract) * On the Geometry of Wn Gravity (Abstract) * O(d, d) Tranformations, Marginal Deformations and the Coset Construction in WZNW Models (Abstract) * Nonperturbative Effects and Multicritical Behaviour of c = 1 Matrix Model (Abstract) * Singular Limits and String Solutions (Abstract) * BV Algebra on the Moduli Spaces of Riemann Surfaces and String Field Theory (Abstract) * 3. Condensed Matter and Statistical Mechanics * Stochastic Dynamics in a Deposition-Evaporation Model on a Line * Models with Inverse-Square Interactions: Conjectured Dynamical Correlation Functions of the Calogero-Sutherland Model at Rational Couplings * Turbulence and Generic Scale Invariance * Singular Perturbation Approach to Phase Ordering Dynamics * Kinetics of Diffusion-Controlled and Ballistically-Controlled Reactions * Field Theory of a Frustrated Heisenberg Spin Chain * FQHE Physics in Relativistic Field Theories * Importance of Initial Conditions in Determining the Dynamical Class of Cellular Automata (Abstract) * Do Hard-Core Bosons Exhibit Quantum Hall Effect? (Abstract) * Hysteresis in Ferromagnets * 4. Fundamental Aspects of Quantum Mechanics and Quantum Field Theory * Finite Quantum Physics and Noncommutative Geometry * Higgs as Gauge Field and the Standard Model * Canonical Quantisation of an Off-Conformal Theory * Deterministic Quantum Mechanics in One Dimension * Spin-Statistics Relations for Topological Geons in 2+1 Quantum Gravity * Generalized Fock Spaces * Geometrical Expression for Short Distance Singularities in Field Theory * 5. Mathematics and Quantum Field Theory * Knot Invariants from Quantum Field Theories * Infinite Grassmannians and Moduli Spaces of G-Bundles * A Review of an Algebraic Geometry Approach to a Model Quantum Field Theory on a Curve (Abstract) * 6. Integrable Models * Spectral Representation of Correlation Functions in Two-Dimensional Quantum Field Theories * On Various Avatars of the Pasquier Algebra * Supersymmetric Integrable Field Theories and Eight Vertex Free Fermion Models (Abstract) * 7. Lattice Field Theory * From Kondo Model and Strong Coupling Lattice QCD to the Isgur-Wise Function * Effective Confinement from a Logarithmically Running Coupling (Abstract)

A PERIPHERAL CHOLINERGIC PATHWAY MODULATES STRESS-INDUCED HYPERTHERMIA IN THE RAT EXPOSED TO AN OPEN FIELD.

EPA Science Inventory

Exposure to an open-field is psychologically stressful and leads to an elevation in core temperature (Tc). This increase in Tc associated with open-field is usually referred to as stress-induced hyperthermia (SIH) and can be blocked centrally with cyclooxygenase inhibitors suc...

Scaling law in free walking of mice in circular open fields of various diameters.

PubMed

Shoji, Hiroto

2016-03-01

Open-field tests are routinely used to study locomotor activity in rodents. I studied the effects of apparatus size on rodent locomotor activity, specifically with respect to how resting and walking periods are interwoven. I explored the open-field behavior of mice utilizing circular open fields of various diameters. When the diameter of the test apparatus was greater than 75 cm, the durations of the resting and moving periods of free walking behavior obeyed bounded power-law distribution functions. I found that the properties of the scaling exponents and model selection became similar for test apparatus diameters greater than 75 cm. These results can provide a guide for the selection of the size of the test apparatus for use in the study of the open-field behavior of rodents.

Enriched Open Field Facilitates Exercise and Social Interaction in 2 Strains of Guinea Pigs (Cavia porcellus)

PubMed Central

Brewer, Jacob S; Bellinger, Seanceray A; Joshi, Prianca; Kleven, Gale A

2014-01-01

Current housing guidelines for laboratory rodents include recommendations for enrichment. Working with guinea pigs, we have developed an open-field enrichment paradigm that provides several aspects of this species’ natural environment. These naturalistic aspects include access to increased space for exploration, access to western timothy (Phleum pratense L.) hay, and grouping as a herd to facilitate social interaction. To determine the immediate effect on behavior from access to the enriched environment, female guinea pigs from 2 strains, IAF Hairless and NIH Hartley, were observed in both standard home cages and an open-field enriched environment. Subjects were housed with cagemates in pairs for the home-cage observation and were grouped as a herd when in the open-field arena. Behaviors were videorecorded for 1 h and then scored. Salivary cortisol levels were measured both prior to and immediately after behavioral observations. Analyses revealed higher levels of activity and social interaction in the open-field arena compared with the home cage, with no significant change in salivary cortisol levels. These results suggest that exposure to the open-field environment provide increased opportunities for exercise and social enrichment. Although additional studies are needed to determine long-term effects on experimental outcomes, the open-field configuration holds promise as a laboratory enrichment paradigm for guinea pigs. PMID:25199089

Dissipation and enantioselective degradation of plant growth retardants paclobutrazol and uniconazole in open field, greenhouse, and laboratory soils.

PubMed

Wu, Chengwang; Sun, Jianqiang; Zhang, Anping; Liu, Weiping

2013-01-15

Greenhouses are increasingly important in human food supply. Pesticides used in greenhouses play important roles in horticulture; however, little is known about their behavior in greenhouse environments. This work investigates the dissipation and enantioselctive degradation of plant growth retardants including paclobutrazol and uniconazole in soils under three conditions (i.e., open field, greenhouse, and laboratory). The dissipation and enantioselective degradation of paclobutrazol and uniconazole in greenhouse were different from those in open field; they were more persistent in greenhouse than in open field soil. Leaching produced by rainfall is responsible for the difference in dissipation. Thus, local environmental impacts may occur more easily inside greenhouses, while groundwater may be more contaminated in open field. Spike concentrations of 5, 10, and 20 times the concentrations of native residues were tested for the enantioselective dissipation of the two pesticides; the most potent enantioselective degradation of paclobutrazol and uniconazole occurred at the 10 times that of the native residues in the greenhouse environments and at 20 times native residues in open field environments. The higher soil activity in greenhouses than in open fields was thought to be responsible for such a difference. The environmental risk and regulation of paclobutrazol and uniconazole should be considered at the enantiomeric level.

Enriched open field facilitates exercise and social interaction in 2 strains of guinea pigs (Cavia porcellus).

PubMed

Brewer, Jacob S; Bellinger, Seanceray A; Joshi, Prianca; Kleven, Gale A

2014-07-01

Current housing guidelines for laboratory rodents include recommendations for enrichment. Working with guinea pigs, we have developed an open-field enrichment paradigm that provides several aspects of this species' natural environment. These naturalistic aspects include access to increased space for exploration, access to western timothy (Phleum pratense L.) hay, and grouping as a herd to facilitate social interaction. To determine the immediate effect on behavior from access to the enriched environment, female guinea pigs from 2 strains, IAF Hairless and NIH Hartley, were observed in both standard home cages and an open-field enriched environment. Subjects were housed with cagemates in pairs for the home-cage observation and were grouped as a herd when in the open-field arena. Behaviors were videorecorded for 1 h and then scored. Salivary cortisol levels were measured both prior to and immediately after behavioral observations. Analyses revealed higher levels of activity and social interaction in the open-field arena compared with the home cage, with no significant change in salivary cortisol levels. These results suggest that exposure to the open-field environment provide increased opportunities for exercise and social enrichment. Although additional studies are needed to determine long-term effects on experimental outcomes, the open-field configuration holds promise as a laboratory enrichment paradigm for guinea pigs.

Anxiolytic effects of lavender oil inhalation on open-field behaviour in rats.

PubMed

Shaw, D; Annett, J M; Doherty, B; Leslie, J C

2007-09-01

To establish a valid animal model of the effects of olfactory stimuli on anxiety, a series of experiments was conducted using rats in an open-field test. Throughout, effects of lavender oil were compared with the effects of chlordiazepoxide (CDP), as a reference anxiolytic with well-known effects on open-field behaviour. Rats were exposed to lavender oil (0.1-1.0 ml) for 30 min (Experiment 1) or 1h (Experiment 2) prior to open-field test and in the open field or injected with CDP (10 mg/kg i.p.). CDP had predicted effects on behaviour, and the higher doses of lavender oil had some effects on behaviour similar to those of CDP. In Experiment 3, various combinations of pre-exposure times and amounts of lavender oil were used. With sufficient exposure time and quantity of lavender the same effects were obtained as in Experiment 2. Experiment 4 demonstrated that these behavioural effects of lavender could be obtained following pre-exposure, even if no oil was present in the open-field test. In Experiments 2-4, lavender oil increased immobility. Together, these experiments suggest that lavender oil does have anxiolytic effects in the open field, but that a sedative effect can also occur at the highest doses.

Social instability stress in adolescence increases anxiety and reduces social interactions in adulthood in male Long-Evans rats.

PubMed

Green, Matthew R; Barnes, Brittany; McCormick, Cheryl M

2013-12-01

We investigated the effects of social instability stress (daily 1-hr isolation, change of cage partner, postnatal day 30-45) in adolescence in male rats on open field exploration and social behavior in adulthood. Social stressed rats had longer latencies to enter the center of an open field and then took longer to approach an object placed in the center of the field. When another rat was placed in the open field, stressed rats spent less time in social interaction than control rats, particularly when paired with another stressed, rather than a control, rat. The groups did not differ in social approach tests (when a stimulus rat was separated by wire mesh) nor in novel object exploration (when controlling for open field anxiety). The results suggest social stress in adolescence increases open field anxiety while maintaining exploratory behavior, and alters social interactions in adulthood. © 2012 Wiley Periodicals, Inc.

Management of whitefly-transmitted viruses in open-field production systems

USDA-ARS?s Scientific Manuscript database

Whiteflies are a key pest of crops in open field production throughout the tropics and subtropics. This is due in large part to the long and diverse list of devastating plant viruses transmitted by these vectors. Open field production provides many challenges to manage these viruses and in many case...

The free energies of partially open coronal magnetic fields

NASA Technical Reports Server (NTRS)

Low, B. C.; Smith, D. F.

1993-01-01

A simple model of the low corona is examined in terms of a static polytropic atmosphere in equilibrium with a global magnetic field. The question posed is whether magnetostatic states with partially open magnetic fields may contain magnetic energies in excess of those in fully open magnetic fields. Based on the analysis presented here, it is concluded that the cross-field electric currents in the pre-eruption corona are a viable source of the bulk of the energies in a mass ejection and its associated flare.

The relation between open-field and emergence tests in a hyperactive mouse model.

PubMed

Lalonde, R; Strazielle, C

2009-12-01

The relation between open-field and emergence tests was examined in mice with idiopathic hypertension. Spontaneous hypertensive mice (SHM) crossed more segments and reared more often in the open-field than normotensive controls at both age levels. In contrast, grooming episodes decreased only in the older SHM cohort. While young SHM emerged more quickly from a toy object only partially, complete emergence was faster only in the older SHM cohort. In the entire series, open-field segments were inversely correlated with 2- and 4-paw emergence latencies. There was also an inverse correlation between rears and 2-paw emergence but a positive correlation between grooming episodes and both types of emergence. In view of its association with open-field activity, the emergence test may have value in screening potential ADHD therapies.

Disruption of coronal magnetic field arcades

NASA Technical Reports Server (NTRS)

Mikic, Zoran; Linker, Jon A.

1994-01-01

The ideal and resistive properties of isolated large-scale coronal magnetic arcades are studied using axisymmetric solutions of the time-dependent magnetohydrodynamic (MHD) equations in spherical geometry. We examine how flares and coronal mass ejections may be initiated by sudden disruptions of the magnetic field. The evolution of coronal arcades in response to applied shearing photospheric flows indicates that disruptive behavior can occur beyond a critical shear. The disruption can be traced to ideal MHD magnetic nonequilibrium. The magnetic field expands outward in a process that opens the field lines and produces a tangential discontinuity in the magnetic field. In the presence of plasma resistivity, the resulting current sheet is the site of rapid reconnection, leading to an impulsive release of magnetic energy, fast flows, and the ejection of a plasmoid. We relate these results to previous studies of force-free fields and to the properties of the open-field configuration. We show that the field lines in an arcade are forced open when the magnetic energy approaches (but is still below) the open-field energy, creating a partially open field in which most of the field lines extend away from the solar surface. Preliminary application of this model to helmet streamers indicates that it is relevant to the initiation of coronal mass ejections.

A hybrid analytical model for open-circuit field calculation of multilayer interior permanent magnet machines

NASA Astrophysics Data System (ADS)

Zhang, Zhen; Xia, Changliang; Yan, Yan; Geng, Qiang; Shi, Tingna

2017-08-01

Due to the complicated rotor structure and nonlinear saturation of rotor bridges, it is difficult to build a fast and accurate analytical field calculation model for multilayer interior permanent magnet (IPM) machines. In this paper, a hybrid analytical model suitable for the open-circuit field calculation of multilayer IPM machines is proposed by coupling the magnetic equivalent circuit (MEC) method and the subdomain technique. In the proposed analytical model, the rotor magnetic field is calculated by the MEC method based on the Kirchhoff's law, while the field in the stator slot, slot opening and air-gap is calculated by subdomain technique based on the Maxwell's equation. To solve the whole field distribution of the multilayer IPM machines, the coupled boundary conditions on the rotor surface are deduced for the coupling of the rotor MEC and the analytical field distribution of the stator slot, slot opening and air-gap. The hybrid analytical model can be used to calculate the open-circuit air-gap field distribution, back electromotive force (EMF) and cogging torque of multilayer IPM machines. Compared with finite element analysis (FEA), it has the advantages of faster modeling, less computation source occupying and shorter time consuming, and meanwhile achieves the approximate accuracy. The analytical model is helpful and applicable for the open-circuit field calculation of multilayer IPM machines with any size and pole/slot number combination.

[OPEN FIELD BEHAVIOR AS A PREDICTIVE CRITERIA REFLECTING RATS CORTICOSTERONELEVEL BEFORE AND AFTER STRESS].

PubMed

Umriukhin, P E; Grigorchuk, O S

2015-12-01

In the presented study we investigated the possibility to use the open field behavior data for prediction of corticosterone level in rat blood plasma before and after stress. It is shown that the most reliable open field behavior parameters, reflecting high probability of significant upregulation of corticosterone after 3 hours of immobilization, are the short latency of first movement and low locomotor activity during the test. Rats with high corticosterone at normal non-stress conditions are characterized by low locomotor activity and on the contrary long latency period for the entrance of open field center.

Study of curved glass photovoltaic module and module electrical isolation design requirements

NASA Technical Reports Server (NTRS)

1980-01-01

The design of a 1.2 by 2.4 m curved glass superstrate and support clip assembly is presented, along with the results of finite element computer analysis and a glass industry survey conducted to assess the technical and economic feasibility of the concept. Installed costs for four curved glass module array configurations are estimated and compared with cost previously reported for comparable flat glass module configurations. Electrical properties of candidate module encapsulation systems are evaluated along with present industry practice for the design and testing of electrical insulation systems. Electric design requirements for module encapsulation systems are also discussed.

Study of curved glass photovoltaic module and module electrical isolation design requirements

NASA Astrophysics Data System (ADS)

1980-06-01

The design of a 1.2 by 2.4 m curved glass superstrate and support clip assembly is presented, along with the results of finite element computer analysis and a glass industry survey conducted to assess the technical and economic feasibility of the concept. Installed costs for four curved glass module array configurations are estimated and compared with cost previously reported for comparable flat glass module configurations. Electrical properties of candidate module encapsulation systems are evaluated along with present industry practice for the design and testing of electrical insulation systems. Electric design requirements for module encapsulation systems are also discussed.

On the Modeling and Experimentation of Electromagnetically Coupled Microstrip Dipole Arrays in a Substrate-Superstrate

DTIC Science & Technology

1990-01-01

methodology for the modeling and design antenna arrays and microstrip discontinuities for microwave circuit applications. I believe that certain outstanding...of the EMCobtain the design curves w as reported later [5]-[7] based on t a s e s i o eh v e n r p r e e e ty [ ] 1 ) nt i solving a Pocklington type...by j"d I ’ My) dy. (8) Y V n In the two design equations ((6) and (7)), Yn,,f, m/ Vn and = Y,11+ Y (2) Y,, can be determined by the method of moments

Implementing odd-axions in dimensional oxidation of 4D non-geometric type IIB scalar potential

NASA Astrophysics Data System (ADS)

Shukla, Pramod

2016-01-01

In a setup of type IIB superstring compactification on an orientifold of a T6 /Z4 sixfold, the presence of geometric flux (ω) and non-geometric fluxes (Q, R) is implemented along with the standard NS-NS and RR three-form fluxes (H, F). After computing the F/D-term contributions to the N = 1 four dimensional effective scalar potential, we rearrange the same into 'suitable' pieces by using a set of new generalized flux orbits. Subsequently, we dimensionally oxidize the various pieces of the total four dimensional scalar potential to guess their ten-dimensional origin.

COBE satellite measurement, hyperspheres, superstrings and the dimension of spacetime.

NASA Astrophysics Data System (ADS)

El Naschie, M. S.

1998-08-01

The first part of the paper attempts to establish connections between hypersphere backing in infinite dimensions, the expectation value of dimE(∞) spacetime and the COBE measurement of the microwave background radiation. One of the main results reported here is that the mean sphere in S(∞) spans a four dimensional manifold and is thus equal to the expectation value of the topological dimension of E(∞). In the second part the author introduces within a general theory, a probabilistic justification for a compactification which reduces an infinite dimensional spacetime E(∞) (n = ∞) to a four dimensional one (DT = n = 4).

Integral glass encapsulation for solar arrays

NASA Technical Reports Server (NTRS)

Landis, G. A.

1981-01-01

Electrostatic bonding technology, an encapsulation technique for terrestrial solar array was developed. The process produces full integral, hermetic bonds with no adhesives or pottants. Panels of six solar cells on a simple glass superstrate were produced. Electrostatic bonding for making the cell front contact was also developed. A metal mesh is trapped into contact with the cell front during the bonding process. Six cell panels using the bonded mesh as the only cell front contact were produced. The possibility of using lower cost glass, with a higher thermal expansion mismatch to silicon, by making lower temperature bonds is developed. However, this requires a planar surface cell.

Performance of a compact, hybrid optical evanescent-wave sensor for chemical and biological applications

NASA Astrophysics Data System (ADS)

Helmers, H.; Greco, Pierre; Benech, Pierre; Rustad, Rolf; Kherrat, Rochdi; Bouvier, Gérard

1996-02-01

We describe a hybrid evanescent-wave sensor component that we fabricated by using an integrated optical interferometer with a specially adapted photodetector array. The design of the interferometer is based on the use of tapered waveguides to obtain two intersecting collimated beams. Phase shifts can be measured with an angular precision of better than 10-3 rad, which corresponds to a superstrate index change inferior of 10-6 with our structure. The interest in the device as a chemical sensor is experimentally demonstrated. The same optical component could be used in a variety of other sensor applications, e.g., biological and immunological sensors.

Encapsulation task of the low-cost silicon solar array project. Investigation of test methods, material properties, and processes for solar cell encapsulants

NASA Technical Reports Server (NTRS)

Willis, P. B.; Baum, B.; White, R. A.

1978-01-01

The results of an investigation of solar module encapsulation systems applicable to the Low-Cost Solar Array Project 1986 cost and performance goals are presented. Six basic construction elements were identified and their specific uses in module construction defined. A uniform coating basis was established for each element. The survey results were also useful in revealing price ranges for classes of materials and estimating the cost allocation for each element within the encapsulating cost goal. The six construction elements were considered to be substrates, superstrates, pottants, adhesives, outer covers and back covers.

A microscopic description of black hole evaporation via holography

DOE PAGES

Berkowitz, Evan; Hanada, Masanori; Maltz, Jonathan

2016-07-19

Here, we propose a description of how a large, cold black hole (black zero-brane) in type IIA superstring theory evaporates into freely propagating D0-branes, by solving the dual gauge theory quantitatively. The energy spectrum of emitted D0-branes is parametrically close to thermal when the black hole is large. The black hole, while initially cold, gradually becomes an extremely hot and stringy object as it evaporates. As it emits D0-branes, its emission rate speeds up and it evaporates completely without leaving any remnant. Hence this system provides us with a concrete holographic description of black hole evaporation without information loss.

A microscopic description of black hole evaporation via holography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berkowitz, Evan; Hanada, Masanori; Maltz, Jonathan

Here, we propose a description of how a large, cold black hole (black zero-brane) in type IIA superstring theory evaporates into freely propagating D0-branes, by solving the dual gauge theory quantitatively. The energy spectrum of emitted D0-branes is parametrically close to thermal when the black hole is large. The black hole, while initially cold, gradually becomes an extremely hot and stringy object as it evaporates. As it emits D0-branes, its emission rate speeds up and it evaporates completely without leaving any remnant. Hence this system provides us with a concrete holographic description of black hole evaporation without information loss.

Investigation of test methods, material properties, and processes for solar cell encapsulants. Encapsulation task of the low-cost silicon solar array project

NASA Technical Reports Server (NTRS)

1977-01-01

During this quarter, flat-plate solar collector systems were considered and six basic construction elements were identified: outer coatings, superstrates, pottants, substrates, undercoats, and adhesives. Materials surveys were then initiated to discover either generic classes or/and specific products to function as each construction element. Cost data included in the surveys permit ready evaluation of each material. Silicones, fluorocarbons, glass, and acrylic polymers have the highest inherent weatherability of materials studied to date. Only acrylics, however, combine low costs, environmental resistance, and potential processability. This class will receive particular emphasis.

E sub 6 leptoquarks and the solar neutrino problem

NASA Technical Reports Server (NTRS)

Roulet, Esteban

1991-01-01

The possibility that non-conventional neutrino oscillations take place in the superstring inspired E sub 6 models is considered. In this context, the influence of leptoquark mediated interactions of the neutrinos with nucleons in the resonant flavor conversion is discussed. It is shown that this effect can be significant for v sub e - v sub tau oscillations if these neutrinos have masses required in the ordinary Mikheyev-Smirnov-Wolfenstein (MSW) effect, and may lead to a solution of the solar neutrino problem even in the absence of vacuum mixings. On the other hand, this model cannot lead to a resonant behavior in the sun if the neutrinos are massless.

Magnetar giant flares in multipolar magnetic fields. I. Fully and partially open eruptions of flux ropes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Lei; Yu, Cong, E-mail: muduri@shao.ac.cn, E-mail: cyu@ynao.ac.cn

2014-04-01

We propose a catastrophic eruption model for the enormous energy release of magnetars during giant flares, in which a toroidal and helically twisted flux rope is embedded within a force-free magnetosphere. The flux rope stays in stable equilibrium states initially and evolves quasi-statically. Upon the loss of equilibrium, the flux rope cannot sustain the stable equilibrium states and erupts catastrophically. During the process, the magnetic energy stored in the magnetosphere is rapidly released as the result of destabilization of global magnetic topology. The magnetospheric energy that could be accumulated is of vital importance for the outbursts of magnetars. We carefullymore » establish the fully open fields and partially open fields for various boundary conditions at the magnetar surface and study the relevant energy thresholds. By investigating the magnetic energy accumulated at the critical catastrophic point, we find that it is possible to drive fully open eruptions for dipole-dominated background fields. Nevertheless, it is hard to generate fully open magnetic eruptions for multipolar background fields. Given the observational importance of the multipolar magnetic fields in the vicinity of the magnetar surface, it would be worthwhile to explore the possibility of the alternative eruption approach in multipolar background fields. Fortunately, we find that flux ropes may give rise to partially open eruptions in the multipolar fields, which involve only partial opening of background fields. The energy release fractions are greater for cases with central-arcaded multipoles than those with central-caved multipoles that emerged in background fields. Eruptions would fail only when the centrally caved multipoles become extremely strong.« less

Effect of interleukin-1beta on the behavior of rats during mild stress in the open-field test.

PubMed

Pertsov, S S; Koplik, E V; Simbirtsev, A S; Kalinichenko, L S

2009-11-01

We studied the effect of interleukin-1beta on the behavior of rats with different individual typological characteristics during mild stress in the open-field test. Intraperitoneal injection of interleukin-1beta (5 microg/kg, 108 U/mg) was followed by a decrease in orientation and exploratory activity of passive and, particularly, of active animals in the open field. As differentiated from rats receiving physiological saline, the initial differences in behavioral characteristics of active and passive animals were not revealed in the repeated test after injection of interleukin-1beta. We conclude that interleukin-1beta abolishes the behavioral differences between active and passive specimens in the open field. These data suggest that administration of interleukin-1beta to rats leads to reorganization of the mechanisms for emotional evaluation of adverse emotiogenic factors under conditions of mild stress in the open-field test.

Current-level triggered plasma-opening switch

DOEpatents

Mendel, C.W.

1987-06-29

An opening switch for very high power electrical pulses uses a slow magnetic field to confine a plasma across a gap between two electrodes. The plasma conducts the electric pulse across the gap while the switch is closed. A magnetic field generated by the pulse repels the slow magnetic field from the negative electrode to push the plasma from the electrode, opening the switch. A plurality of radial vanes may be used to enhance the slow magnetic field. 5 figs.

Current-level triggered plasma-opening switch

DOEpatents

Mendel, Clifford W.

1989-01-01

An opening switch for very high power electrical pulses uses a slow magnetic field to confine a plasma across a gap between two electrodes. The plasma conducts the electric pulse across the gap while the switch is closed. A magnetic field generated by the pulse repels the slow magnetic field from the negative electrode to push the plasma from the electrode, opening the switch. A plurality of radial vanes may be used to enhance the slow magnetic field.

Weather forecasting with open source software

NASA Astrophysics Data System (ADS)

Rautenhaus, Marc; Dörnbrack, Andreas

2013-04-01

To forecast the weather situation during aircraft-based atmospheric field campaigns, we employ a tool chain of existing and self-developed open source software tools and open standards. Of particular value are the Python programming language with its extension libraries NumPy, SciPy, PyQt4, Matplotlib and the basemap toolkit, the NetCDF standard with the Climate and Forecast (CF) Metadata conventions, and the Open Geospatial Consortium Web Map Service standard. These open source libraries and open standards helped to implement the "Mission Support System", a Web Map Service based tool to support weather forecasting and flight planning during field campaigns. The tool has been implemented in Python and has also been released as open source (Rautenhaus et al., Geosci. Model Dev., 5, 55-71, 2012). In this presentation we discuss the usage of free and open source software for weather forecasting in the context of research flight planning, and highlight how the field campaign work benefits from using open source tools and open standards.

Olfactory source localization in the open field using one or both nostrils.

PubMed

Welge-Lussen, A; Looser, G L; Westermann, B; Hummel, T

2014-03-01

This study aims to examine humans ́ abilities to localize odorants within the open field. Young participants were tested on a localization task using a relatively selective olfactory stimulus (2-phenylethyl-alcohol, PEA) and cineol, an odorant with a strong trigeminal component. Participants were blindfolded and had to localize an odorant source at 2 m distance (far-field condition) and a 0.4 m distance (near-field condition) with either two nostrils open or only one open nostril. For the odorant with trigeminal properties, the number of correct trials did not differ when one or both nostrils were used, while more PEA localization trials were correctly completed with both rather than one nostril. In the near-field condition, correct localization was possible in 72-80% of the trials, irrespective of the odorant and the number of nostrils used. Localization accuracy, measured as spatial deviation from the olfactory source, was significantly higher in the near-field compared to the far-field condition, but independent of the odorant being localized. Odorant localization within the open field is difficult, but possible. In contrast to the general view, humans seem to be able to exploit the two-nostril advantage with increasing task difficulty.

Former Spencer Artillery Range, Tennessee Classification Demonstration Open Field and Dynamic Areas

DTIC Science & Technology

2016-01-01

DEMONSTRATION REPORT Former Spencer Artillery Range, Tennessee Classification Demonstration Open Field and Dynamic Areas ESTCP...AVAILABILITY STATEMENT 13. SUPPLEMENTARY NOTES 14. ABSTRACT 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: a. REPORT b. ABSTRACT c. THIS PAGE 17...2016 Technical Report N/A Former Spencer Artillery Range, Tennessee Classification Demonstration Open Field and Dynamic Areas Richard MacNeil, USA

Shear-induced opening of the coronal magnetic field

NASA Technical Reports Server (NTRS)

Wolfson, Richard

1995-01-01

This work describes the evolution of a model solar corona in response to motions of the footpoints of its magnetic field. The mathematics involved is semianalytic, with the only numerical solution being that of an ordinary differential equation. This approach, while lacking the flexibility and physical details of full MHD simulations, allows for very rapid computation along with complete and rigorous exploration of the model's implications. We find that the model coronal field bulges upward, at first slowly and then more dramatically, in response to footpoint displacements. The energy in the field rises monotonically from that of the initial potential state, and the field configuration and energy appraoch asymptotically that of a fully open field. Concurrently, electric currents develop and concentrate into a current sheet as the limiting case of the open field is approached. Examination of the equations shows rigorously that in the asymptotic limit of the fully open field, the current layer becomes a true ideal MHD singularity.

First CCD UBVI photometric analysis of six open cluster candidates

NASA Astrophysics Data System (ADS)

Piatti, A. E.; Clariá, J. J.; Ahumada, A. V.

2011-04-01

We have obtained CCD UBVIKC photometry down to V ˜ 22 for the open cluster candidates Haffner 3, Haffner 5, NGC 2368, Haffner 25, Hogg 3 and Hogg 4 and their surrounding fields. None of these objects have been photometrically studied so far. Our analysis shows that these stellar groups are not genuine open clusters since no clear main sequences or other meaningful features can be seen in their colour-magnitude and colour-colour diagrams. We checked for possible differential reddening across the studied fields that could be hiding the characteristics of real open clusters. However, the dust in the directions to these objects appears to be uniformly distributed. Moreover, star counts carried out within and outside the open cluster candidate fields do not support the hypothesis that these objects are real open clusters or even open cluster remnants.

Initial results for the silicon monolithically interconnected solar cell product

NASA Technical Reports Server (NTRS)

Dinetta, L. C.; Shreve, K. P.; Cotter, J. E.; Barnett, A. M.

1995-01-01

This proprietary technology is based on AstroPower's electrostatic bonding and innovative silicon solar cell processing techniques. Electrostatic bonding allows silicon wafers to be permanently attached to a thermally matched glass superstrate and then thinned to final thicknesses less than 25 micron. These devices are based on the features of a thin, light-trapping silicon solar cell: high voltage, high current, light weight (high specific power) and high radiation resistance. Monolithic interconnection allows the fabrication costs on a per watt basis to be roughly independent of the array size, power or voltage, therefore, the cost effectiveness to manufacture solar cell arrays with output powers ranging from milliwatts up to four watts and output voltages ranging from 5 to 500 volts will be similar. This compares favorably to conventionally manufactured, commercial solar cell arrays, where handling of small parts is very labor intensive and costly. In this way, a wide variety of product specifications can be met using the same fabrication techniques. Prototype solar cells have demonstrated efficiencies greater than 11%. An open-circuit voltage of 5.4 volts, fill factor of 65%, and short-circuit current density of 28 mA/sq cm at AM1.5 illumination are typical. Future efforts are being directed to optimization of the solar cell operating characteristics as well as production processing. The monolithic approach has a number of inherent advantages, including reduced cost per interconnect and increased reliability of array connections. These features make this proprietary technology an excellent candidate for a large number of consumer products.

Jet outflow and open field line measurements on the C-2U advanced beam-driven field-reversed configuration plasma experiment.

PubMed

Sheftman, D; Gupta, D; Roche, T; Thompson, M C; Giammanco, F; Conti, F; Marsili, P; Moreno, C D

2016-11-01

Knowledge and control of the axial outflow of plasma particles and energy along open-magnetic-field lines are of crucial importance to the stability and longevity of the advanced beam-driven field-reversed configuration plasma. An overview of the diagnostic methods used to perform measurements on the open field line plasma on C-2U is presented, including passive Doppler impurity spectroscopy, microwave interferometry, and triple Langmuir probe measurements. Results of these measurements provide the jet ion temperature and axial velocity, electron density, and high frequency density fluctuations.

Jet outflow and open field line measurements on the C-2U advanced beam-driven field-reversed configuration plasma experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheftman, D., E-mail: dsheftman@trialphaenergy.com; Gupta, D.; Roche, T.

Knowledge and control of the axial outflow of plasma particles and energy along open-magnetic-field lines are of crucial importance to the stability and longevity of the advanced beam-driven field-reversed configuration plasma. An overview of the diagnostic methods used to perform measurements on the open field line plasma on C-2U is presented, including passive Doppler impurity spectroscopy, microwave interferometry, and triple Langmuir probe measurements. Results of these measurements provide the jet ion temperature and axial velocity, electron density, and high frequency density fluctuations.

A nonsingular model of the open magnetosphere

NASA Technical Reports Server (NTRS)

Toffoletto, F. R.; Hill, T. W.

1993-01-01

We present a modified version of the Toffoletto and Hill (1989) open magnetosphere model that incorporates a tail-like interconection field with a discontinuity 10 represent the slow-mode expansion fan that defines the high-latitude tail magnetopause. (The interconnection field is defined as the perturbation on an initially closed magnetosphere model to make it open.) The expansion fan controls the open field line region in the tail, and the intersection of the fan with the tail current sheet is, by design, the x line. The new interconnection field allows greater control of the tail field structure; in particular, it enables us to eliminate the nightside mapping singularity that occurs in previous models when the interplanetary magnetic field is nonsouthward. Also, in contrast to earlier models, the far tail x line extends farther downstream on the flanks than in the center of the tail, consistent with observations.

48 CFR 2406.304-70 - Approval of the justification-field procurements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Other Than Full and Open Competition 2406.304-70 Approval of the justification—field procurements. (a) The justification for other than full and open competition for field procurements shall be approved in... justification-field procurements. 2406.304-70 Section 2406.304-70 Federal Acquisition Regulations System...

47 CFR 2.1053 - Measurements required: Field strength of spurious radiation.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... For equipment operating on frequencies below 890 MHz, an open field test is normally required, with... either impractical or impossible to make open field measurements (e.g. a broadcast transmitter installed... 47 Telecommunication 1 2010-10-01 2010-10-01 false Measurements required: Field strength of...

Examination of an optical transmittance test for photovoltaic encapsulation materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, David C.; Bengoechea, Jaione; Bokria, Jayesh G.

2013-09-24

The optical transmittance of encapsulation materials is a key characteristic for their use in photovoltaic (PV) modules. Changes in transmittance with time in the field affect module performance, which may impact product warranties. Transmittance is important in product development, module manufacturing, and field power production (both immediate and long-term). Therefore, an international standard (IEC 62788-1-4) has recently been proposed by the Encapsulation Task-Group within the Working Group 2 (WG2) of the International Electrotechnical Commission (IEC) Technical Committee 82 (TC82) for the quantification of the optical performance of PV encapsulation materials. Existing standards, such as ASTM E903, are general and moremore » appropriately applied to concentrated solar power than to PV. Starting from the optical transmittance measurement, the solar-weighted transmittance of photon irradiance, yellowness index (which may be used in aging studies to assess durability), and ultraviolet (UV) cut-off wavelength may all be determined using the proposed standard. The details of the proposed test are described. The results of a round-robin experiment (for five materials) conducted at seven laboratories to validate the test procedure using representative materials are also presented. For example, the Encapsulation Group actively explored the measurement requirements (wavelength range and resolution), the requirements for the spectrophotometer (including the integrating sphere and instrument accessories, such as a depolarizer), specimen requirements (choice of glass-superstrate and -substrate), and data analysis (relative to the light that may be used in the PV application). The round-robin experiment identified both intra- and inter-laboratory instrument precision and bias for five encapsulation materials (encompassing a range of transmittance and haze-formation characteristics).« less

Examination of an Optical Transmittance Test for Photovoltaic Encapsulation Materials (Presentation)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, D.; Bengoechea, J.; Bokria, J.

2013-09-01

The optical transmittance of encapsulation materials is a key characteristic for their use in photovoltaic (PV) modules. Changes in transmittance with time in the field affect module performance, which may impact product warranties. Transmittance is important in product development, module manufacturing, and field power production (both immediate and long-term). Therefore, an international standard (IEC 62788-1-4) has recently been proposed by the Encapsulation Task-Group within the Working Group 2 (WG2) of the International Electrotechnical Commission (IEC) Technical Committee 82 (TC82) for the quantification of the optical performance of PV encapsulation materials. Existing standards, such as ASTM E903, are general and moremore » appropriately applied to concentrated solar power than to PV. Starting from the optical transmittance measurement, the solar-weighted transmittance of photon irradiance, yellowness index (which may be used in aging studies to assess durability), and ultraviolet (UV) cut-off wavelength may all be determined using the proposed standard. The details of the proposed test are described. The results of a round-robin experiment (for five materials) conducted at seven laboratories to validate the test procedure using representative materials are also presented. For example, the Encapsulation Group actively explored the measurement requirements (wavelength range and resolution), the requirements for the spectrophotometer (including the integrating sphere and instrument accessories, such as a depolarizer), specimen requirements (choice of glass-superstrate and -substrate), and data analysis (relative to the light that may be used in the PV application). The round-robin experiment identified both intra- and inter-laboratory instrument precision and bias for five encapsulation materials (encompassing a range of transmittance and haze-formation characteristics).« less

Thermal relics: Do we know their abundances

NASA Technical Reports Server (NTRS)

Kamionkowski, Marc; Turner, Michael S.

1990-01-01

The relic abundance of a particle species that was once in thermal equilibrium in the expanding Universe depends upon a competition between the annihilation rate of the species and the expansion rate of the Universe. Assuming that the Universe is radiation dominated at early times the relic abundance is easy to compute and well known. At times earlier than about 1 sec after the bang there is little or no evidence that the Universe had to be radiation dominated, although that is the simplest and standard assumption. Because early-Universe relics are of such importance both to particle physics and to cosmology, three nonstandard possibilities are considered in detail for the Universe at the time a species' abundance froze in: energy density dominated by shear (i.e., anisotropic expansion), energy density dominated by some other nonrelativistic species, and energy density dominated by the kinetic energy of the scalar field that sets the gravitational constant in a Brans-Dicke-Jordan cosmological mode. In the second case the relic abundance is less than the standard value, while in the other two cases it can be enhanced by a significant factor. Two other more exotic possibilities for enhancing the relic abundance of a species are also mentioned--a larger value of Newton's constant at early times (e.g., as might occur in superstring or Kaluza-Klein theories) or a component of the energy density at early times with a very stiff equation of state (p greater than rho/3), e.g., a scalar field phi with potential V(phi) = Beta /phi/ (exp n) with n greater than 4. Results have implications for dark matter searches and searches for particle relics in general.

Scale invariance of the η-deformed AdS5 × S5 superstring, T-duality and modified type II equations

NASA Astrophysics Data System (ADS)

Arutyunov, G.; Frolov, S.; Hoare, B.; Roiban, R.; Tseytlin, A. A.

2016-02-01

We consider the ABF background underlying the η-deformed AdS5 ×S5 sigma model. This background fails to satisfy the standard IIB supergravity equations which indicates that the corresponding sigma model is not Weyl invariant, i.e. does not define a critical string theory in the usual sense. We argue that the ABF background should still define a UV finite theory on a flat 2d world-sheet implying that the η-deformed model is scale invariant. This property follows from the formal relation via T-duality between the η-deformed model and the one defined by an exact type IIB supergravity solution that has 6 isometries albeit broken by a linear dilaton. We find that the ABF background satisfies candidate type IIB scale invariance conditions which for the R-R field strengths are of the second order in derivatives. Surprisingly, we also find that the ABF background obeys an interesting modification of the standard IIB supergravity equations that are first order in derivatives of R-R fields. These modified equations explicitly depend on Killing vectors of the ABF background and, although not universal, they imply the universal scale invariance conditions. Moreover, we show that it is precisely the non-isometric dilaton of the T-dual solution that leads, after T-duality, to modification of type II equations from their standard form. We conjecture that the modified equations should follow from κ-symmetry of the η-deformed model. All our observations apply also to η-deformations of AdS3 ×S3 ×T4and AdS2 ×S2 ×T6models.

Integrability in AdS/CFT correspondence: quasi-classical analysis

NASA Astrophysics Data System (ADS)

Gromov, Nikolay

2009-06-01

In this review, we consider a quasi-classical method applicable to integrable field theories which is based on a classical integrable structure—the algebraic curve. We apply it to the Green-Schwarz superstring on the AdS5 × S5 space. We show that the proposed method reproduces perfectly the earlier results obtained by expanding the string action for some simple classical solutions. The construction is explicitly covariant and is not based on a particular parameterization of the fields and as a result is free from ambiguities. On the other hand, the finite size corrections in some particularly important scaling limit are studied in this paper for a system of Bethe equations. For the general superalgebra \\su(N|K) , the result for the 1/L corrections is obtained. We find an integral equation which describes these corrections in a closed form. As an application, we consider the conjectured Beisert-Staudacher (BS) equations with the Hernandez-Lopez dressing factor where the finite size corrections should reproduce quasi-classical results around a general classical solution. Indeed, we show that our integral equation can be interpreted as a sum of all physical fluctuations and thus prove the complete one-loop consistency of the BS equations. We demonstrate that any local conserved charge (including the AdS energy) computed from the BS equations is indeed given at one loop by the sum of the charges of fluctuations with an exponential precision for large S5 angular momentum of the string. As an independent result, the BS equations in an \\su(2) sub-sector were derived from Zamolodchikovs's S-matrix. The paper is based on the author's PhD thesis.

Scale invariance of the η-deformed AdS 5 × S 5 superstring, T-duality and modified type II equations

DOE PAGES

Arutyunov, G.; Frolov, S.; Hoare, B.; ...

2015-12-23

We consider the ABF background underlying the η-deformed AdS 5 × S 5 sigma model. This background fails to satisfy the standard IIB supergravity equations which indicates that the corresponding sigma model is not Weyl invariant, i.e. does not define a critical string theory in the usual sense. We argue that the ABF background should still define a UV finite theory on a flat 2d world-sheet implying that the η-deformed model is scale invariant. This property follows from the formal relation via T-duality between the η-deformed model and the one defined by an exact type IIB supergravity solution that hasmore » 6 isometries albeit broken by a linear dilaton. We find that the ABF background satisfies candidate type IIB scale invariance conditions which for the R–R field strengths are of the second order in derivatives. Surprisingly, we also find that the ABF background obeys an interesting modification of the standard IIB supergravity equations that are first order in derivatives of R–R fields. These modified equations explicitly depend on Killing vectors of the ABF background and, although not universal, they imply the universal scale invariance conditions. Moreover, we show that it is precisely the non-isometric dilaton of the T-dual solution that leads, after T-duality, to modification of type II equations from their standard form. We conjecture that the modified equations should follow from κ-symmetry of the η-deformed model. All our observations apply also to η-deformations of AdS 3 × S 3 × T 4 and AdS 2 × S 2 × T 6 models.« less

Manual versus Automated Rodent Behavioral Assessment: Comparing Efficacy and Ease of Bederson and Garcia Neurological Deficit Scores to an Open Field Video-Tracking System.

PubMed

Desland, Fiona A; Afzal, Aqeela; Warraich, Zuha; Mocco, J

2014-01-01

Animal models of stroke have been crucial in advancing our understanding of the pathophysiology of cerebral ischemia. Currently, the standards for determining neurological deficit in rodents are the Bederson and Garcia scales, manual assessments scoring animals based on parameters ranked on a narrow scale of severity. Automated open field analysis of a live-video tracking system that analyzes animal behavior may provide a more sensitive test. Results obtained from the manual Bederson and Garcia scales did not show significant differences between pre- and post-stroke animals in a small cohort. When using the same cohort, however, post-stroke data obtained from automated open field analysis showed significant differences in several parameters. Furthermore, large cohort analysis also demonstrated increased sensitivity with automated open field analysis versus the Bederson and Garcia scales. These early data indicate use of automated open field analysis software may provide a more sensitive assessment when compared to traditional Bederson and Garcia scales.

Relations between open-field, elevated plus-maze, and emergence tests as displayed by C57/BL6J and BALB/c mice.

PubMed

Lalonde, R; Strazielle, C

2008-06-15

The relations between open-field, elevated plus-maze, and emergence tests were examined in two strains of mice. In the open-field, C57BL/6J mice had more ambulatory movements and rears but not stereotyped movements relative to BALB/c. In addition, C57BL/6J mice entered more often than BALB/c into enclosed and open arms of the elevated plus-maze. When placed inside a large enclosure, C57BL/6J mice emerged more quickly than BALB/c from a small toy object. In the entire series of mice, ambulation and rears in the open-field were linearly correlated with open and enclosed arm visits in the elevated plus-maze. Ambulatory movements and rears were also correlated with emergence latencies. In contrast, stereotyped movements were correlated with emergence latencies, but not with any elevated plus-maze value. These results specify the extent and limits of association between the three tests.

Forward Field Computation with OpenMEEG

PubMed Central

Gramfort, Alexandre; Papadopoulo, Théodore; Olivi, Emmanuel; Clerc, Maureen

2011-01-01

To recover the sources giving rise to electro- and magnetoencephalography in individual measurements, realistic physiological modeling is required, and accurate numerical solutions must be computed. We present OpenMEEG, which solves the electromagnetic forward problem in the quasistatic regime, for head models with piecewise constant conductivity. The core of OpenMEEG consists of the symmetric Boundary Element Method, which is based on an extended Green Representation theorem. OpenMEEG is able to provide lead fields for four different electromagnetic forward problems: Electroencephalography (EEG), Magnetoencephalography (MEG), Electrical Impedance Tomography (EIT), and intracranial electric potentials (IPs). OpenMEEG is open source and multiplatform. It can be used from Python and Matlab in conjunction with toolboxes that solve the inverse problem; its integration within FieldTrip is operational since release 2.0. PMID:21437231

A Measurement and Analysis of Buildup Region Dose for Open Field Photon Beams (Cobalt-60 through 24 MV)

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCullough, Edwin C.

2015-01-15

The central axis depth dose in the build-up region (surface to d{sub max}) of single open field photon beams (cobalt-60 through 24 MV) has been measured utilizing parallel plate and extrapolation chamber methodology. These data were used to derive, for a prescription dose of 100 cGy, values of surface dose, the maximum value of dose along the central axis (D{sub max}) and the depth (nearest the surface) at which 90% of the prescription dose occurs (d{sub 90}). For both single and parallel opposed pair (POP) open field configurations, data are presented at field sizes of 5 × 5, 15 ×more » 15 and 25 × 25 cm{sup 2} for prescription depths of 10, 15 and 20 cm (midplane for POP). For the treatment machines, field sizes, and prescription depths studied, it is possible to conclude that: for single open field irradiation, surface dose values (as a percentage of the prescription dose) can be either low (<10%) or comparable to the prescription dose itself; for POP open fields, surface dose values are relatively independent of photon energy and midplane depth, and range between 30% and 70% of prescription dose, being principally dependent on field size; the depth of the initial 90 cGy point for a prescription dose of 100 cGy, d{sub 90}, was larger for POP fields. For either single or POP open field treatments, d{sub 90} was always less than 22 mm, while for 6 MV or less, values of d{sub 90} were less than 4 mm; D{sub max} values can be very large (e.g., above 300 cGy) for certain treatment situations and are reduced significantly for POP treatments; for open field POP treatments, the percent reduction in D{sub max} with each increment in beam energy above 10 MV is reduced over that seen at 10 MV or less and, possibly, this further reduction may be clinically insignificant; for open field POP treatments, changes in surface dose, d{sub 90} and D{sub max} with beam energy above 10 MV do not suggest, with regard to these specific build-up curve parameters, any obvious advantage for treatment with beam energies greater than 10 MV for the specific machines and situations studied.« less

Effect of biomass open burning on particulate matter and polycyclic aromatic hydrocarbon concentration levels and PAH dry deposition in ambient air.

PubMed

Chiu, Jui C; Shen, Yun H; Li, Hsing W; Chang, Shun S; Wang, Lin C; Chang-Chien, Guo P

2011-01-01

The objectives of the present study were to investigate particulate matter (PM) and polycyclic aromatic hydrocarbon (PAH) concentrations in ambient air during rice straw open burning and non-open burning periods. In the ambient air of a rice field, the mean PM concentration during and after an open burning event were 1828 and 102 μg m⁻³, respectively, which demonstrates that during a rice field open burning event, the PM concentration in the ambient air of rice field is over 17 times higher than that of the non-open burning period. During an open burning event, the mean total PAH and total toxic equivalence (BaP(eq)) concentrations in the ambient air of a rice field were 7206 ng m⁻³ and 10.3 ng m⁻³, respectively, whereas after the open burning event, they were 376 ng m⁻³ and 1.50 ng m⁻³, respectively. Open burning thus increases total PAH and total BaP(eq) concentrations by 19-fold and 6.8-fold, respectively. During a rice straw open burning event, in the ambient air of a rice field, the mean dry deposition fluxes of total PAHs and total BaP(eq) were 1222 μg m⁻² day⁻¹ and 4.80 μg m⁻² day⁻¹, respectively, which are approximately 60- and 3-fold higher than those during the non-open burning period, respectively. During the non-open burning period, particle-bound PAHs contributed 79.2-84.2% of total dry deposition fluxes (gas + particle) of total PAHs. However, an open burning event increases the contribution to total PAH dry deposition by particle-bound PAHs by up to 85.9-95.5%. The results show that due to the increased amount of PM in the ambient air resulting from rice straw open burning, particle-bound PAHs contributed more to dry deposition fluxes of total PAHs than they do during non-open burning periods. The results show that biomass (rice straw) open burning is an important PAH emission source that significantly increases both PM and PAH concentration levels and PAH dry deposition in ambient air.

An efficient hexagonal switched beam antenna structure based on Fabry-Perot cavity leaky-wave antenna

NASA Astrophysics Data System (ADS)

Aymen El Cafsi, Mohamed; Nedil, Mourad; Osman, Lotfi; Gharsallah, Ali

2015-11-01

A novel design of switched beam antenna (SBA) system based on Fabry-Perot cavity leaky-wave antenna (FPC LWA) is designed and fabricated for base station operating in the unlicensed ISM central frequency band at 5.8 GHz of the wireless local area network (WLAN) standard. The proposed SBA is designed with hexagonal shape of FPC LWA Arrays in order to get 360° of coverage. The single element of FPC LWA array is composed of a patch antenna and covered by a Partially Reflective Surface (PRS), which is composed of a Metal Strip Grating and printed on a high permittivity Superstrate. First, the Transmission Line Model of FPC LWA is introduced to analyse and calculate the far-field components in E- and H planes by using the Transverse Equivalent Network. This approach is then compared with other full wave's commercial software such as Ansoft HFSS and CST Microwave Studio. Second, a parametric study is performed to evaluate the effect of the angle formed by the two successive FPC LWA on the radiation efficiency of the activate sector. To examine the performance of the proposed SBA, experimental prototype was fabricated and measured. As a result, multiple orthogonal beams (six beams) of 10 dBi of gain with low Side Lobes Level and 360° of coverage are produced. This SBA structure is suitable for WLAN communication systems.

Sources of magnetic fields in recurrent interplanetary streams

NASA Technical Reports Server (NTRS)

Burlaga, L. F.; Behannon, K. W.; Hansen, S. F.; Pneuman, G. W.; Feldman, W. C.

1978-01-01

The paper examines sources of magnetic fields in recurrent streams observed by the Imp 8 and Heos spacecraft at 1 AU and by Mariner 10 en route to Mercury between October 31, 1973 and February 9, 1974, during Carrington rotations 1607-1610. Although most fields and plasmas at 1 AU were related to coronal holes and the magnetic field lines were open in those holes, some of the magnetic fields and plasmas at 1 AU were related to open field line regions on the sun which were not associated with known coronal holes, indicating that open field lines may be more basic than coronal holes as sources of the solar wind. Magnetic field intensities in five equatorial coronal holes, certain photospheric magnetic fields, and the coronal footprints of the sector boundaries on the source surface are characterized.

Inflation and shadow matter

NASA Technical Reports Server (NTRS)

Krauss, L. M.; Guth, A. H.; Spergel, D. N.; Field, G. B.; Press, W. H.

1986-01-01

The possible production of shadow matter during the period of cosmic inflation is considered. The superstring theory of Gross et al. (1985), which results in a gauge group E8 x E8, could, at low energies, result in the existence of two sectors: an observed sector associated with all familiar particles and interactions, and a hidden one whose particles couple only through gravitational interactions with ordinary matter. It is demonstrated here that if, in the early universe, an inflationary phase is associated with the breaking of one of the symmetries in the E8 x E8 theory, this strongly constrains the physics of both sectors if shadow matter is to be the missing mass in the universe.

Radiative Kähler moduli stabilization

NASA Astrophysics Data System (ADS)

Kobayashi, Tatsuo; Omoto, Naoya; Otsuka, Hajime; Tatsuishi, Takuya H.

2018-05-01

We propose a new type of Kähler moduli stabilization mechanisms in type IIB superstring theory on Calabi-Yau manifolds with the positive Euler number. The overall Kähler modulus can be perturbatively stabilized by radiative corrections due to sparticles. Its minimum is the anti-de Sitter vacuum, where supersymmetry is broken. We can uplift it to the de Sitter vacuum by introducing anti-D-branes, keeping the modulus stabilized. Although our numerical results depend on the choice of the cutoff scale and degeneracies of sparticles, at any rate there exist the parameter spaces where the masses of Kaluza-Klein and stringy modes are larger than the cutoff scale. Furthermore, this stabilization scenario predicts an ultralight axion.

Superstrate sub-cell voltage-matched multijunction solar cells

DOEpatents

Mascarenhas, Angelo; Alberi, Kirstin

2016-03-15

Voltage-matched thin film multijunction solar cell and methods of producing cells having upper CdTe pn junction layers formed on a transparent substrate which in the completed device is operatively positioned in a superstate configuration. The solar cell also includes a lower pn junction formed independently of the CdTe pn junction and an insulating layer between CdTe and lower pn junctions. The voltage-matched thin film multijunction solar cells further include a parallel connection between the CdTe pn junction and lower pn junctions to form a two-terminal photonic device. Methods of fabricating devices from independently produced upper CdTe junction layers and lower junction layers are also disclosed.

Transmogrifying fuzzy vortices

NASA Astrophysics Data System (ADS)

Murugan, Jeff; Millner, Antony

2004-04-01

We show that the construction of vortex solitons of the noncommutative abelian-Higgs model can be extended to a critically coupled gauged linear sigma model with Fayet-Illiopolous D-terms. Like its commutative counterpart, this fuzzy linear sigma model has a rich spectrum of BPS solutions. We offer an explicit construction of the degree-k static semilocal vortex and study in some detail the infinite coupling limit in which it descends to a degree-k Bbb CBbb PkN instanton. This relation between the fuzzy vortex and noncommutative lump is used to suggest an interpretation of the noncommutative sigma model soliton as tilted D-strings stretched between an NS5-brane and a stack of D3-branes in type-IIB superstring theory.

μ-near-zero metamaterial slabs for a new concept of plasmonic sensing platforms

NASA Astrophysics Data System (ADS)

Girón-Sedas, J. A.; Oliveira, Osvaldo N.; Mejía-Salazar, J. R.

2018-05-01

We demonstrate that the excitation of magnetic bulk plasmon-like resonances in μ-near-zero double-negative metamaterial slabs is suitable for the design of new sensing platforms, where light-to-plasmon coupling is reached without requiring a prism or grating coupler. This allows for excitation with light coming directly from the air and for dielectric substrates with any refractive index. In the microwave region this architecture is able to detect changes as small as 10-2 in the refractive index of the superstrate. If the metamaterial slab is backed by a metallic substrate, on the other hand, the system can be used as a light-absorber for light harvesting applications.

Development of new EVA formulations for improved performance at NREL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pern, F.J.

1997-02-01

We review in chronological order the research stages and fundamental concepts involved in developing modified and new EVA formulations for improved performance against photo-induced degradation and discoloration. The new NREL EVA formulations use additives totally different from the present commercial formulations (EVA A9918 and EVA 15295). Validation of their long-term photostability and thermostability is presently under way. Together with UV-absorbing glass superstrates, they may offer better success in achieving a more reliable module performance and longer service life without significant EVA discoloration problems, which are commonly experienced with EVA A9918 and, at a lesser rate, EVA 15295. {copyright} {ital 1997more » American Institute of Physics.}« less

Widening Access through Openness in Higher Education in the Developing World: A Bourdieusian Field Analysis of Experiences from the National Open University of Nigeria

ERIC Educational Resources Information Center

Olakulehin, Felix Kayode; Singh, Gurmit

2013-01-01

Bourdieu has argued that higher education is a field that reproduces social inequality, thus complicating how openness widens access to higher education in the developing world. Drawing on the experiences of the National Open University of Nigeria (NOUN), this paper critically analyses and evaluates the rationale, approach, difficulties,…

Poster - 23: Dosimetric Characterization and Transferability of an Accessory Mounted Mini-Beam Collimator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, William; Crewson, Cody; Alexander, Andrew

Objective: The dosimetric characterization of an accessory-mounted mini-beam collimator across three beam matched linear accelerators. Materials and Methods: Percent depth dose and profiles were measured for the open and mini-beam collimated fields. The average beam quality and peak-to-valley dose ratio (PVDR), the ratio of average peak dose to average valley dose, were obtained from these measurements. The open field relative output and the mini-beam collimator factor, the ratio of the mini-beam dose to open field dose at the beam center, were measured for square fields of side 2, 3, 4, and 5 cm. Mini-beam output as a function of collimatormore » inclination angle relative to the central axis was also investigated. Results and Discussion: Beam quality for both the open and mini-beam collimated fields agreed across all linacs to within ±1.0%. The PVDR was found to vary by up to ±6.6% from the mean. For the 2, 3, and 4 cm fields the average open field relative output with respect to the 5 cm field was 0.874±0.4%, 0.921±0.3%, and 0.962±0.1%. The average collimator factors were 0.450±3.9%, 0.443±3.9%, 0.438±3.9%, and 0.434±3.9%. A decrease in collimator factor greater than 7% was found for an inclination angle change of 0.09°. Conclusion: The mini-beam collimator has revealed a difference between the three linacs not apparent in the open field data, yet transferability can still be attained through thorough dosimetric characterization.« less

A study of the electric field in an open magnetospheric model

NASA Technical Reports Server (NTRS)

Stern, D. P.

1973-01-01

Recently, Svalgaard and Heppner reported two separate features of the polar electromagnetic field that correlate with the dawn-dusk component of the interplanetary magnetic field. This work attempts to explain these findings in terms of properties of the open magnetosphere. The topology and qualitative properties of the open magnetosphere are first studied by means of a simple model, consisting of a dipole in a constant field. Many such properties are found to depend on the separation line, a curve connecting neutral points and separating different field line regimes. In the simple model it turns out that the electric field in the central polar cap tends to point from dawn to dusk for a wide variety of external fields, but, near the boundary of the polar cap, electric equipotentials are deformed into crescents.

Interchange Slip-Running Reconnection and Sweeping SEP-Beams

NASA Technical Reports Server (NTRS)

Masson, S.; Aulanier, G.; Pariat, E.; Klein, K.-L.

2011-01-01

We present a new model to explain how particles, accelerated at a reconnection site that is not magnetically connected to the Earth, could eventually propagate along the well-connected open flux tube. Our model is based on the results of a low-beta resistive magnetohydrodynamics simulation of a three-dimensional line-tied and initially current-free bipole, that is embedded in a non-uniform open potential field. The topology of this configuration is that of an asymmetric coronal null-point, with a closed fan surface and an open outer spine. When driven by slow photospheric shearing motions, field lines, initially fully anchored below the fan dome, reconnect at the null point, and jump to the open magnetic domain. This is the standard interchange mode as sketched and calculated in 2D. The key result in 3D is that, reconnected open field lines located in the vicinity of the outer spine, keep reconnecting continuously, across an open quasi-separatrix layer, as previously identified for non-open-null-point reconnection. The apparent slipping motion of these field lines leads to form an extended narrow magnetic flux tube at high altitude. Because of the slip-running reconnection, we conjecture that if energetic particles would be travelling through, or be accelerated inside, the diffusion region, they would be successively injected along continuously reconnecting field lines that are connected farther and farther from the spine. At the scale of the full Sun, owing to the super-radial expansion of field lines below 3 solar radius, such energetic particles could easily be injected in field lines slipping over significant distances, and could eventually reach the distant flux tube that is well-connected to the Earth.

Open magnetic fields in active regions

NASA Technical Reports Server (NTRS)

Svestka, Z.; Solodyna, C. V.; Howard, R.; Levine, R. H.

1977-01-01

Soft X-ray images and magnetograms of several active regions and coronal holes are examined which support the interpretation that some of the dark X-ray gaps seen between interconnecting loops and inner cores of active regions are foot points of open field lines inside the active regions. Characteristics of the investigated dark gaps are summarized. All the active regions with dark X-ray gaps at the proper place and with the correct polarity predicted by global potential extrapolation of photospheric magnetic fields are shown to be old active regions, indicating that field opening is accomplished only in a late phase of active-region development. It is noted that some of the observed dark gaps probably have nothing in common with open fields, but are either due to the decreased temperature in low-lying portions of interconnecting loops or are the roots of higher and less dense or cooler loops.

Relationship between Birkeland current regions, particle precipitation, and electric fields

NASA Technical Reports Server (NTRS)

De La Beaujardiere, O.; Watermann, J.; Newell, P.; Rich, F.

1993-01-01

The relationship of the large-scale dayside Birkeland currents to large-scale particle precipitation patterns, currents, and convection is examined using DMSP and Sondrestrom radar observations. It is found that the local time of the mantle currents is not limited to the longitude of the cusp proper, but covers a larger local time extent. The mantle currents flow entirely on open field lines. About half of region 1 currents flow on open field lines, consistent with the assumption that the region 1 currents are generated by the solar wind dynamo and flow within the surface that separates open and closed field lines. More than 80 percent of the Birkeland current boundaries do not correspond to particle precipitation boundaries. Region 2 currents extend beyond the plasma sheet poleward boundary; region 1 currents flow in part on open field lines; mantle currents and mantle particles are not coincident. On most passes when a triple current sheet is observed, the convection reversal is located on closed field lines.

Solar Open Flux Migration from Pole to Pole: Magnetic Field Reversal.

PubMed

Huang, G-H; Lin, C-H; Lee, L C

2017-08-25

Coronal holes are solar regions with low soft X-ray or low extreme ultraviolet intensities. The magnetic fields from coronal holes extend far away from the Sun, and thus they are identified as regions with open magnetic field lines. Coronal holes are concentrated in the polar regions during the sunspot minimum phase, and spread to lower latitude during the rising phase of solar activity. In this work, we identify coronal holes with outward and inward open magnetic fluxes being in the opposite poles during solar quiet period. We find that during the sunspot rising phase, the outward and inward open fluxes perform pole-to-pole trans-equatorial migrations in opposite directions. The migration of the open fluxes consists of three parts: open flux areas migrating across the equator, new open flux areas generated in the low latitude and migrating poleward, and new open flux areas locally generated in the polar region. All three components contribute to the reversal of magnetic polarity. The percentage of contribution from each component is different for different solar cycle. Our results also show that the sunspot number is positively correlated with the lower-latitude open magnetic flux area, but negatively correlated with the total open flux area.

The Evolution of Open Magnetic Flux Driven by Photospheric Dynamics

NASA Technical Reports Server (NTRS)

Linker, Jon A.; Lionello, Roberto; Mikic, Zoran; Titov, Viacheslav S.; Antiochos, Spiro K.

2010-01-01

The coronal magnetic field is of paramount importance in solar and heliospheric physics. Two profoundly different views of the coronal magnetic field have emerged. In quasi-steady models, the predominant source of open magnetic field is in coronal holes. In contrast, in the interchange model, the open magnetic flux is conserved, and the coronal magnetic field can only respond to the photospheric evolution via interchange reconnection. In this view the open magnetic flux diffuses through the closed, streamer belt fields, and substantial open flux is present in the streamer belt during solar minimum. However, Antiochos and co-workers, in the form of a conjecture, argued that truly isolated open flux cannot exist in a configuration with one heliospheric current sheet (HCS) - it will connect via narrow corridors to the polar coronal hole of the same polarity. This contradicts the requirements of the interchange model. We have performed an MHD simulation of the solar corona up to 20R solar to test both the interchange model and the Antiochos conjecture. We use a synoptic map for Carrington Rotation 1913 as the boundary condition for the model, with two small bipoles introduced into the region where a positive polarity extended coronal hole forms. We introduce flows at the photospheric boundary surface to see if open flux associated with the bipoles can be moved into the closed-field region. Interchange reconnection does occur in response to these motions. However, we find that the open magnetic flux cannot be simply injected into closed-field regions - the flux eventually closes down and disconnected flux is created. Flux either opens or closes, as required, to maintain topologically distinct open and closed field regions, with no indiscriminate mixing of the two. The early evolution conforms to the Antiochos conjecture in that a narrow corridor of open flux connects the portion of the coronal hole that is nearly detached by one of the bipoles. In the later evolution, a detached coronal hole forms, in apparent violation of the Antiochos conjecture. Further investigation reveals that this detached coronal hole is actually linked to the extended coronal hole by a separatrix footprint on the photosphere of zero width. Therefore, the essential idea of the conjecture is preserved, if we modify it to state that coronal holes in the same polarity region are always linked, either by finite width corridors or separatrix footprints. The implications of these results for interchange reconnection and the sources of the slow solar wind are briefly discussed.

The Evolution of Open Magnetic Flux Driven by Photospheric Dynamics

NASA Astrophysics Data System (ADS)

Linker, Jon A.; Lionello, Roberto; Mikić, Zoran; Titov, Viacheslav S.; Antiochos, Spiro K.

2011-04-01

The coronal magnetic field is of paramount importance in solar and heliospheric physics. Two profoundly different views of the coronal magnetic field have emerged. In quasi-steady models, the predominant source of open magnetic field is in coronal holes. In contrast, in the interchange model, the open magnetic flux is conserved, and the coronal magnetic field can only respond to the photospheric evolution via interchange reconnection. In this view, the open magnetic flux diffuses through the closed, streamer belt fields, and substantial open flux is present in the streamer belt during solar minimum. However, Antiochos and coworkers, in the form of a conjecture, argued that truly isolated open flux cannot exist in a configuration with one heliospheric current sheet—it will connect via narrow corridors to the polar coronal hole of the same polarity. This contradicts the requirements of the interchange model. We have performed an MHD simulation of the solar corona up to 20 R sun to test both the interchange model and the Antiochos conjecture. We use a synoptic map for Carrington rotation 1913 as the boundary condition for the model, with two small bipoles introduced into the region where a positive polarity extended coronal hole forms. We introduce flows at the photospheric boundary surface to see if open flux associated with the bipoles can be moved into the closed-field region. Interchange reconnection does occur in response to these motions. However, we find that the open magnetic flux cannot be simply injected into closed-field regions—the flux eventually closes down and disconnected flux is created. Flux either opens or closes, as required, to maintain topologically distinct open- and closed-field regions, with no indiscriminate mixing of the two. The early evolution conforms to the Antiochos conjecture in that a narrow corridor of open flux connects the portion of the coronal hole that is nearly detached by one of the bipoles. In the later evolution, a detached coronal hole forms, in apparent violation of the Antiochos conjecture. Further investigation reveals that this detached coronal hole is actually linked to the extended coronal hole by a separatrix footprint on the photosphere of zero width. Therefore, the essential idea of the conjecture is preserved, if we modify it to state that coronal holes in the same polarity region are always linked, either by finite width corridors or separatrix footprints. The implications of these results for interchange reconnection and the sources of the slow solar wind are briefly discussed.

Parallel inhomogeneity and the Alfven resonance. 1: Open field lines

NASA Technical Reports Server (NTRS)

Hansen, P. J.; Harrold, B. G.

1994-01-01

In light of a recent demonstration of the general nonexistence of a singularity at the Alfven resonance in cold, ideal, linearized magnetohydrodynamics, we examine the effect of a small density gradient parallel to uniform, open ambient magnetic field lines. To lowest order, energy deposition is quantitatively unaffected but occurs continuously over a thickened layer. This effect is illustrated in a numerical analysis of a plasma sheet boundary layer model with perfectly absorbing boundary conditions. Consequences of the results are discussed, both for the open field line approximation and for the ensuing closed field line analysis.

MAVEN observations of complex magnetic field configuration in the Martian magnetotail

NASA Astrophysics Data System (ADS)

DiBraccio, G. A.; Luhmann, J. G.; Curry, S.; Espley, J. R.; Gruesbeck, J.; Xu, S.; Mitchell, D. L.; Soobiah, Y. I. J.; Connerney, J. E. P.; Dong, C.; Harada, Y.; Ruhunusiri, S.; Halekas, J. S.; Hara, T.; Ma, Y.; Brain, D.; Jakosky, B. M.

2017-12-01

The magnetosphere of Mars has attributes of both induced and intrinsic magnetospheres, forming as a result of direct solar wind interaction with the planet's upper atmosphere and local crustal magnetic fields. Magnetic reconnection is able to occur between the draped interplanetary magnetic field (IMF) and closed crustal magnetic fields, creating an open field topology with one end attached to the planet and the other flowing in the solar wind. For this reason, the Martian magnetotail becomes a complex menagerie of various field topologies that may contribute to atmospheric escape to space. We explore these magnetic topologies in the Martian magnetotail using a combination of observations from the the Mars Atmosphere Volatile EvolutioN (MAVEN) spacecraft along with magnetohydrodynamic (MHD) simulations. Preliminary MHD results suggest that the central tail contains two lobes composed of open crustal fields, which are twisted by roughly 45°, either clockwise or counterclockwise from the ecliptic plane, in response to the east-west component of the IMF. These simulated open-field lobes are enveloped by an induced comet-like tail formed by the draped IMF. Using two Earth years of data, we analyze MAVEN Magnetometer and Solar Wind Ion Analyzer (SWIA) measurements to assess the tail magnetic field configuration as a function of IMF orientation. We infer, through data-model comparisons, that the open-field tail lobes are likely a result of reconnection between the crustal fields and the IMF. The open topology of these fields may in fact contribute to atmospheric loss to space. This investigation confirms that the Martian magnetotail is a hybrid configuration between intrinsic and induced magnetospheres, shifting the paradigm of Mars' magnetosphere as we have understood it thus far.

Dynamics of the Transition Corona

NASA Technical Reports Server (NTRS)

Masson, Sophie; McCauley, Patrick; Golub, Leon; Reeves, Katharine K.; DeLuca, Edward E.

2014-01-01

Magnetic reconnection between the open and closed magnetic fields in the corona is believed to play a crucial role in the corona/heliosphere coupling. At large scale, the exchange of open/closed connectivity is expected to occur in pseudo-streamer (PS) structures. However, there is neither clear observational evidence of how such coupling occurs in PSs, nor evidence for how the magnetic reconnection evolves. Using a newly developed technique, we enhance the off-limb magnetic fine structures observed with the Atmospheric Imaging Assembly and identify a PS-like feature located close to the northern coronal hole. We first identify that the magnetic topology associated with the observation is a PS, null-point (NP) related topology bounded by the open field. By comparing the magnetic field configuration with the extreme ultraviolet (EUV) emission regions, we determined that most of the magnetic flux associated with plasma emission are small loops below the PS basic NP and open field bounding the PS topology. In order to interpret the evolution of the PS, we referred to a three-dimensional MHD interchange reconnection modeling the exchange of connectivity between small closed loops and the open field. The observed PS fine structures follow the dynamics of the magnetic field before and after reconnecting at the NP obtained by the interchange model. Moreover, the pattern of the EUV plasma emission is the same as the shape of the expected plasma emission location derived from the simulation. These morphological and dynamical similarities between the PS observations and the results from the simulation strongly suggest that the evolution of the PS, and in particular the opening/closing of the field, occurs via interchange/slipping reconnection at the basic NP of the PS. Besides identifying the mechanism at work in the large-scale coupling between the open and closed fields, our results highlight that interchange reconnection in PSs is a gradual physical process that differs from the impulsive reconnection of the solar-jet model.

47 CFR 2.1053 - Measurements required: Field strength of spurious radiation.

Code of Federal Regulations, 2012 CFR

2012-10-01

... operation. Curves or equivalent data shall be supplied showing the magnitude of each harmonic and other.... For equipment operating on frequencies below 890 MHz, an open field test is normally required, with... either impractical or impossible to make open field measurements (e.g. a broadcast transmitter installed...

On the Helicity of Open Magnetic Fields

NASA Astrophysics Data System (ADS)

Prior, C.; Yeates, A. R.

2014-06-01

We reconsider the topological interpretation of magnetic helicity for magnetic fields in open domains, and relate this to the relative helicity. Specifically, our domains stretch between two parallel planes, and each of these ends may be magnetically open. It is demonstrated that, while the magnetic helicity is gauge-dependent, its value in any gauge may be physically interpreted as the average winding number among all pairs of field lines with respect to some orthonormal frame field. In fact, the choice of gauge is equivalent to the choice of reference field in the relative helicity, meaning that the magnetic helicity is no less physically meaningful. We prove that a particular gauge always measures the winding with respect to a fixed frame, and propose that this is normally the best choice. For periodic fields, this choice is equivalent to measuring relative helicity with respect to a potential reference field. However, for aperiodic fields, we show that the potential field can be twisted. We prove by construction that there always exists a possible untwisted reference field.

A study of the electric field in an open magnetospheric model

NASA Technical Reports Server (NTRS)

Stern, D. P.

1972-01-01

The qualitative properties of an open magnetosphere and its electric field are examined and compared to a simple model of a dipole in a constant field and to actual observations. Many of these properties are found to depend on the separatrix, a curve connecting neutral points and separating different field-line regimes. In the simple model, the electric field in the central polar cap tends to point from dawn to dusk for a wide choice of external fields. Near the boundary of the polar cap electric equipotentials curve and become crescent-shaped, which may explain the correlation of polar magnetic variations with the azimuthal component of the interplanetary magnetic field, reported by Svalgaard. Modifications expected to occur in the actual magnetosphere are also investigated: in particular, it appears that bending of equipotentials may be reduced by cross-field flow during the merging of field lines and that open field lines connected to the polar caps emerge from a long and narrow slot extending along the tail.

Sources of magnetic fields in recurrent interplanetary streams

NASA Technical Reports Server (NTRS)

Burlaga, L. F.; Behannon, K. W.; Hansen, S. F.; Pneuman, G. W.; Feldman, W. C.

1977-01-01

The sources of magnetic fields in recurrent streams were examined. Most fields and plasmas at 1 AU were related to coronal holes, and the magnetic field lines were open in those holes. Some of the magnetic fields and plasmas were related to open field line regions on the sun which were not associated with known coronal holes, indicating that open field lines are more basic than coronal holes as sources of the solar wind. Magnetic field intensities in five equatorial coronal holes ranged from 2G to 18G. Average measured photospheric magnetic fields along the footprints of the corresponding unipolar fields on circular equatorial arcs at 2.5 solar radii had a similar range and average, but in two cases the intensities were approximately three times higher than the projected intensities. The coronal footprints of the sector boundaries on the source surface at 2.5 solar radii, meandered between -45 deg and +45 deg latitude, and their inclination ranged from near zero to near ninety degrees.

Control of the Tomato Leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), in Open-Field Tomatoes by Indigenous Natural Enemies Occurring in Israel.

PubMed

Shaltiel-Harpaz, Liora; Gerling, Dan; Graph, Shaul; Kedoshim, Hendrika; Azolay, Lotem; Rozenberg, Tamir; Nachache, Yaakov; Steinberg, Shimon; Allouche, Arnon; Alon, Tamar

2016-02-01

The tomato leafminer, Tuta absoluta (Meyrick), had established in Israel by 2010, attacking both open-field tomatoes and greenhouse crops.We searched for its natural enemies in open-field tomatoes, and tried to determine their potential for controlling this pest. We surveyed the local natural enemies in open tomato fields and measured their impact on pest populations in an unsprayed field. We assessed the suppressive ability of the dominant hemipteran predator, Nesidiocoris tenuis Reuter, against T. absoluta under controlled laboratory conditions and evaluated the impact of its augmentation on T. absoluta control in open-field tomatoes. We found five natural enemy species:the predator, N. tenuis, two braconids, and two eulophids. Predation accounted for 64.5±9.2% (mean ± SE) of T. absoluta larval mortality, whereas parasitism accounted for 20.96±7.5%. Together, they eliminated the pest population at tomato harvest time. Under controlled conditions, predation by N. tenuis rose from 58 to 72% with increased density of T. absoluta, suggesting positive density dependence. The reduction of T. absoluta (83%) by N. tenuis was higher than that of Bemisia tabaci (32%), suggesting a preference of N. tenuis for T. absoluta. Augmentation of N.tenuis was as effective as conventional treatment insecticide treatment, and plant damage was low and did not seem to affect yield. Results indicate that reduced pesticide use enables indigenous natural enemies, particularly N.tenuis, to successfully control T. absoluta and prevent crop damage in open-field tomatoes.

40 CFR 49.133 - Rule for agricultural burning permits.

Code of Federal Regulations, 2010 CFR

2010-07-01

.... (v) A description of the burning method(s) to be used (pile or stack burn, open field or broadcast burn, windrow burn, mobile field sanitizer, etc.) and the amount of material to be burned with each... person must comply with § 49.131 General rule for open burning or the EPA-approved Tribal open burning...

Interchange Reconnection Associated with a Confined Filament Eruption: Implications for the Source of Transient Cold-dense Plasma in Solar Winds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Ruisheng; Chen, Yao; Wang, Bing

The cold-dense plasma is occasionally detected in the solar wind with in situ data, but the source of the cold-dense plasma remains illusive. Interchange reconnections (IRs) between closed fields and nearby open fields are known to contribute to the formation of solar winds. We present a confined filament eruption associated with a puff-like coronal mass ejection (CME) on 2014 December 24. The filament underwent successive activations and finally erupted, due to continuous magnetic flux cancelations and emergences. The confined erupting filament showed a clear untwist motion, and most of the filament material fell back. During the eruption, some tiny blobsmore » escaped from the confined filament body, along newly formed open field lines rooted around the south end of the filament, and some bright plasma flowed from the north end of the filament to remote sites at nearby open fields. The newly formed open field lines shifted southward with multiple branches. The puff-like CME also showed multiple bright fronts and a clear southward shift. All the results indicate an intermittent IR existed between closed fields of the confined erupting filament and nearby open fields, which released a portion of filament material (blobs) to form the puff-like CME. We suggest that the IR provides a possible source of cold-dense plasma in the solar wind.« less

Depressed emission between magnetic arcades near a sunspot

NASA Astrophysics Data System (ADS)

Ryabov, B. I.; Shibasaki, K.

The locations of the depressed emission in microwaves, EUV and soft X-rays are compared with each other and with the location of the plasma outflow in the active region (AR) 8535 on the Sun. We found that two open-field regions overlap the regions of depressed emission near the AR's sunspot. These two open-field regions are simulated with the potential-field source-surface (PFSS) model under radial distances of RSS = 1.8 R⊙ and RSS = 2.5 R⊙. Each open-field region is located between the arcades of the loops of the same magnetic polarity. The former open-field region covers the region of the plasma outflow, which is thus useful for the tests on connection to the heliosphere. The utmost microwave depression of the intensity in the ordinary mode (the Very Large Array 15 GHz observations) also overlaps the region of the plasma outflow and thus indicates this outflow. The lasting for eight days depression in soft X-rays and the SOHO EIT 2.84× 10-8 m images are attributed to the evacuation of as hot coronal plasma as T≥ 2× 106 K from the extended in height (``open") magnetic structures. We conclude that the AR 8535 presents the sunspot atmosphere affected by the large-scale magnetic fields.

Simulation and Analysis of Electric Field for the Disconnector Switch Incomplete Opening Position Based on 220kV GIS

NASA Astrophysics Data System (ADS)

Wang, Feifeng; Huang, Huimin; Su, Yi; Yan, Dandan; Lu, Yufeng; Xia, Xiaofei; Yang, Jian

2018-05-01

It has accounted for a large proportion of GIS equipment defects, which cause the disconnector switches to incomplete open-close position. Once opening operation is not in place, it will arouse continuous arcing between contacts to reduce insulation strength. Otherwise, the intense heat give rise to burn the contact, which has a severe effect on the safe operation of power grid. This paper analyzes some typical defection cases about the opening operation incomplete for disconnector switches of GIS. The COMSOL Multiphysics is applied to verify the influence on electric field distribution. The results show that moving contact out shield is 20 mm, the electric field distribution of the moving contact surface is uneven, and the maximum electric field value can reach 9.74 kV/mm.

Open-field exposure facilitates consummatory extinction.

PubMed

Justel, Nadia; Psyrdellis, Mariana; Pautassi, Ricardo M

2016-12-07

During extinction, the organism learns that a conditioned stimulus or a conditioned response is no longer associated with an unconditioned stimulus, and as a consequence, a decrement in the response is presented. The exposure to novel situations (e.g. exploration of a novel open field) has been used widely to modulate (i.e. either enhance or deteriorate) learning and memory. The aim of the present study was to test whether open-field exposure could modulate consummatory extinction. The results indicated that open-field exposure accelerated the extinction response (i.e. experimental animals provided novelty exposure had lower consummatory behavior than control animals) when applied before - but not after - the first extinction trial, or when applied before the second extinction trial. The results suggest that environmental treatments such as novelty exposure provide a valuable, nonpharmacological alternative to potentially modulate extinction processes.

The Open Flux Problem

NASA Astrophysics Data System (ADS)

Linker, J. A.; Caplan, R. M.; Downs, C.; Riley, P.; Mikic, Z.; Lionello, R.; Henney, C. J.; Arge, C. N.; Liu, Y.; Derosa, M. L.; Yeates, A.; Owens, M. J.

2017-10-01

The heliospheric magnetic field is of pivotal importance in solar and space physics. The field is rooted in the Sun’s photosphere, where it has been observed for many years. Global maps of the solar magnetic field based on full-disk magnetograms are commonly used as boundary conditions for coronal and solar wind models. Two primary observational constraints on the models are (1) the open field regions in the model should approximately correspond to coronal holes (CHs) observed in emission and (2) the magnitude of the open magnetic flux in the model should match that inferred from in situ spacecraft measurements. In this study, we calculate both magnetohydrodynamic and potential field source surface solutions using 14 different magnetic maps produced from five different types of observatory magnetograms, for the time period surrounding 2010 July. We have found that for all of the model/map combinations, models that have CH areas close to observations underestimate the interplanetary magnetic flux, or, conversely, for models to match the interplanetary flux, the modeled open field regions are larger than CHs observed in EUV emission. In an alternative approach, we estimate the open magnetic flux entirely from solar observations by combining automatically detected CHs for Carrington rotation 2098 with observatory synoptic magnetic maps. This approach also underestimates the interplanetary magnetic flux. Our results imply that either typical observatory maps underestimate the Sun’s magnetic flux, or a significant portion of the open magnetic flux is not rooted in regions that are obviously dark in EUV and X-ray emission.

Effects of a single inhalative exposure to formaldehyde on the open field behavior of mice.

PubMed

Malek, Fathi A; Möritz, Klaus-Uwe; Fanghänel, Jochen

2004-02-01

The effects of formaldehyde on the explorative behavior and locomotor activity of mice after a single inhalative exposure were examined in an open field. Adult male mice were exposed to approximately 1.1 ppm, 2.3 ppm, or 5.2 ppm formaldehyde vapour for 2 hours and the open field test was carried out two hours after the end of exposure (trial 1) and repeated 24 hours thereafter (trial 2). The following behavioral parameters were quantitatively examined: numbers of crossed floor squares (inner, peripheral, total), sniffing, grooming, rearing, climbing, and incidence of fecal boli. The results of the first trial revealed that the motion activity was significantly reduced in all exposed groups. In the 1.1 ppm group, the frequency of rearing was reduced and that of floor sniffing increased. The exposure to the two higher formaldehyde concentrations caused a significant decrease in total numbers of floor squares crossed by the subjects, air sniffing, and rearing. The open field test on the next day (trial 2) showed that the frequencies of floor sniffing, grooming, and rearing in all formaldehyde groups were significantly altered. In the 2.5 ppm group, an increased incidence of fecal boli was observed. From the results obtained, we conclude that the exposure of male mice to formaldehyde vapour affects their locomotor and explorative activity in the open field, and that some open field parameters are still altered in the exposed animals even after 24 hours.

The Open Flux Problem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Linker, J. A.; Caplan, R. M.; Downs, C.

The heliospheric magnetic field is of pivotal importance in solar and space physics. The field is rooted in the Sun’s photosphere, where it has been observed for many years. Global maps of the solar magnetic field based on full-disk magnetograms are commonly used as boundary conditions for coronal and solar wind models. Two primary observational constraints on the models are (1) the open field regions in the model should approximately correspond to coronal holes (CHs) observed in emission and (2) the magnitude of the open magnetic flux in the model should match that inferred from in situ spacecraft measurements. Inmore » this study, we calculate both magnetohydrodynamic and potential field source surface solutions using 14 different magnetic maps produced from five different types of observatory magnetograms, for the time period surrounding 2010 July. We have found that for all of the model/map combinations, models that have CH areas close to observations underestimate the interplanetary magnetic flux, or, conversely, for models to match the interplanetary flux, the modeled open field regions are larger than CHs observed in EUV emission. In an alternative approach, we estimate the open magnetic flux entirely from solar observations by combining automatically detected CHs for Carrington rotation 2098 with observatory synoptic magnetic maps. This approach also underestimates the interplanetary magnetic flux. Our results imply that either typical observatory maps underestimate the Sun’s magnetic flux, or a significant portion of the open magnetic flux is not rooted in regions that are obviously dark in EUV and X-ray emission.« less

The complex magnetic field configuration of the Martian magnetotail as observed by MAVEN

NASA Astrophysics Data System (ADS)

DiBraccio, Gina A.; Luhmann, Janet; Curry, Shannon; Espley, Jared R.; Gruesbeck, Jacob; Xu, Shaosui; Mitchell, David; Soobiah, Yasir; Connerney, John E. P.; Dong, Chuanfei; Harada, Yuki; Ruhunusiri, Suranga; Halekas, Jasper; Hara, Takuya; Ma, Yingjuan; Brain, David; Jakosky, Bruce

2017-10-01

The Martian magnetosphere forms as the solar wind directly interacts with the planet’s upper atmosphere. During this interaction, the Sun’s interplanetary magnetic field (IMF) drapes around the planet and local crustal magnetic fields, creating a magnetosphere configuration that has attributes of both an induced magnetosphere like that of Venus, and a complex, small-scale magnetosphere like the Moon. In addition to the closed crustal fields and draped IMF at Mars, open magnetic fields are created when magnetic reconnection occurs between the planetary fields and the IMF. These various field topologies present a complex magnetotail structure that we are now able to explore using a combination of MAVEN observations and magnetohydrodynamic (MHD) simulations. Preliminary MHD results have suggested that the Martian magnetotail includes a dual-lobe component, composed of open crustal fields, enveloped by an induced comet-like tail. These simulated open-field lobes are twisted by roughly 45°, either clockwise or counterclockwise, from the ecliptic plane. This rotation depends on the east-west component of the IMF. We utilize MAVEN Magnetometer and Solar Wind Ion Analyzer (SWIA) measurements collected over two Earth years to analyze the tail magnetic field configuration as a function of IMF direction. Cross-tail views of the average measured magnetic field components directed toward and away from the planet are compared for a variety of solar wind parameters. We find that, in agreement with simulation results, the east-west IMF component strongly affects the magnetotail structure, twisting its sunward-antisunward polarity patterns in response to changing IMF orientation. Through a data-model comparison we are able to infer that regions of open magnetic fields in the tail are likely reconnected crustal fields. Futhermore, these open fields in the tail may contribute to atmospheric escape to space. From this investigation we are able to confirm that the Martian magnetotail is a hybrid configuration between intrinsic and induced magnetospheres, shifting the paradigm of Mars’ magnetosphere as we have understood it thus far.

The behaviour of the paradise fish (Macropodus opercularis) in two different open-fields. A correlation study.

PubMed

Gerlai, R; Csányi, V

1987-01-01

The behaviour of the paradise fish in a traditional "closed" and in a new "transparent" open-field was investigated. The traditional way of measuring ambulation scores was extended by recording ethologically defined behaviour units. The correlations found between the scores measured in the "closed" field and those measured in the "transparent" field are discussed in this paper.

ISEE 1 charged particle observations indicative of open magnetospheric field lines near the subsolar region

NASA Technical Reports Server (NTRS)

Williams, D. J.; Frank, L. A.

1980-01-01

On November 20, 1977, at 0230-0300 UT, ISEE 1 encountered unusual charged particle distributions within the magnetosphere. The three-dimensional distribution observations for energetic (greater than 24 keV) ions and plasma show the development of field-aligned asymmetries in the energetic ion distributions simultaneously with a marked change in plasma flow. It is concluded that the most likely explanation for these observations is that ISEE 1 encountered open magnetospheric field lines at its position within the magnetosphere (1030 LT and 1200 plus or minus 300 km from the magnetopause). Field lines were open near the geomagnetic equator, and the geometry was spatially or temporally variable. Other features of the field line topology are presented.

Topics in string theory

NASA Astrophysics Data System (ADS)

Jejjala, Vishnumohan

2002-01-01

This Thesis explores aspects of superstring theory on orbifold spaces and applies some of the intuition gleaned from the study of the non-commutative geometry of space-time to understanding the fractional quantum Hall effect. The moduli space of vacua of marginal and relevant deformations of N = 4 super-Yang-Mills gauge theory in four dimensions is interpreted in terms of non-commutative geometry. A formalism for thinking about the algebraic geometry of the moduli space is developed. Within this framework, the representation theory of the algebras studied provides a natural exposition of D-brane fractionation. The non-commutative moduli space of deformations preserving N = 1 supersymmetry is examined in detail through various examples. In string theory, by the AdS/CFT correspondence, deformations of the N = 4 field theory are dual to the near-horizon geometries of D-branes on orbifolds of AdS5 x S 5. The physics of D-branes on the dual AdS backgrounds is explored. Quivers encapsulate the matter content of supersymmetric field theories on the worldvolumes of D-branes at orbifold singularities. New techniques for constructing quivers are presented here. When N is a normal subgroup of a finite group G, the quiver corresponding to fixed points of the orbifold M/G is computed from a G/N action on the quiver corresponding to M/G . These techniques prove useful for constructing non-Abelian quivers and for examining discrete torsion orbifolds. Quivers obtained through our constructions contain interesting low-energy phenomenology. The matter content on a brane at an isolated singularity of the Delta27 orbifold embeds the Standard Model. The symmetries of the quiver require exactly three generations of fields in the particle spectrum. Lepton masses are suppressed relative to quark masses because lepton Yukawa couplings do not appear in the superpotential. Lepton masses are generated through the Kahler potential and are related to the supersymmetry breaking scale. The model makes falsifiable predictions about TeV scale physics. Susskind has proposed that the fractional quantum Hall system can be realized through an Abelian Chern-Simons theory with a Moyal product. Susskind's Chern-Simons field is a hydrodynamical quantity. Lopez and Fradkin have an alternate Chern-Simons description couched in terms of a statistical gauge field. We show that this statistical Chern-Simons theory also possesses a non-commutative structure and develop the dictionary between the two Chern-Simons pictures.

Thin-film module circuit design: Practical and reliability aspects

NASA Technical Reports Server (NTRS)

Daiello, R. V.; Twesme, E. N.

1985-01-01

This paper will address several aspects of the design and construction of submodules based on thin film amorphous silicon (a-Si) p i n solar cells. Starting from presently attainable single cell characteristics, and a realistic set of specifications, practical module designs are discussed from the viewpoints of efficient designs, the fabrication requirements, and reliability concerns. The examples center mostly on series interconnected modules of the superstrate type with detailed discussions of each portion of the structure in relation to its influence on module efficiency. Emphasis is placed on engineering topics such as: area coverage, optimal geometries, and cost and reliability. Practical constraints on achieving optimal designs, along with some examples of potential pitfalls in the manufacture and subsequent performance of a-Si modules are discussed.

New BCJ representations for one-loop amplitudes in gauge theories and gravity

NASA Astrophysics Data System (ADS)

He, Song; Schlotterer, Oliver; Zhang, Yong

2018-05-01

We explain a procedure to manifest the Bern-Carrasco-Johansson duality between color and kinematics in n-point one-loop amplitudes of a variety of supersymmetric gauge theories. Explicit amplitude representations are constructed through a systematic reorganization of the integrands in the Cachazo-He-Yuan formalism. Our construction holds for any nonzero number of supersymmetries and does not depend on the number of spacetime dimensions. The cancellations from supersymmetry multiplets in the loop as well as the resulting power counting of loop momenta is manifested along the lines of the corresponding superstring computations. The setup is used to derive the one-loop version of the Kawai-Lewellen-Tye formula for the loop integrands of gravitational amplitudes.

Investigation of Test Methods, Material Properties, and Processes for Solar Cell Encapsulents

NASA Technical Reports Server (NTRS)

1978-01-01

The technical activities were directed toward the assessment of encapsulation processes for use with ethylene/vinyl acetate copolymer as the pottant. Potentially successful formulations were prepared by compounding the raw polymer with ultraviolet absorbers and crosslinking agents to give stabilized and curable compositions. The compounded resin was then converted to a more useful form with an extruder to give pottant in sheets that could be more easily used in lamination. After experimenting with various techniques, the vacuum-bag process was found to be an excellent encapsulation method. Miniature single-celled and multi-celled solar modules of both substrate and superstrate designs were prepared by this technique. The resulting modules were of good appearance, were bubble-free, and successfully passed the thermal cycle test.

Evaluation available encapsulation materials for low-cost long-life silicon photovoltaic arrays

NASA Technical Reports Server (NTRS)

Carmichael, D. C.; Gaines, G. B.; Noel, G. T.; Sliemers, F. A.; Nance, G. P.; Bunk, A. R.; Brockway, M. C.

1978-01-01

Experimental evaluation of selected encapsulation designs and materials based on an earlier study which have potential for use in low cost, long-life photovoltaic arrays are reported. The performance of candidate materials and encapsulated cells were evaluated principally for three types of encapsulation designs based on their potentially low materials and processing costs: (1) polymeric coatings, transparent conformal coatings over the cell with a structural-support substrate; (2) polymeric film lamination, cells laminated between two films or sheets of polymeric materials; and (3) glass-covered systems, cells adhesively bonded to a glass cover (superstrate) with a polymeric pottant and a glass or other substrate material. Several other design types, including those utilizing polymer sheet and pottant materials, were also included in the investigation.

On open and closed field line regions in Tsyganenko's field model and their possible associations with horse collar auroras

NASA Technical Reports Server (NTRS)

Birn, J.; Hones, E. W., Jr.; Craven, J. D.; Frank, L. A.; Elphinstone, R. D.; Stern, D. P.

1991-01-01

The boundary between open and closed field lines is investigated in the empirical Tsyganenko (1987) magnetic field model. All field lines extending to distances beyond -70 R(E), the tailward velocity limit of the Tsyganenko model are defined as open, while all other field lines, which cross the equatorial plane earthward of -70 R(E) and are connected with the earth at both ends, are assumed closed. It is found that this boundary at the surface of the earth, identified as the polar cap boundary, can exhibit the arrowhead shape, pointed toward the sun, which is found in horse collar auroras. For increasing activity levels, the polar cap increases in area and becomes rounder, so that the arrowhead shape is less pronounced. The presence of a net B(y) component can also lead to considerable rounding of the open flux region. The arrowhead shape is found to be closely associated with the increase of B(z) from the midnight region to the flanks of the tail, consistent with a similar increase of the plasma sheet thickness.

The effects of gonadectomy and binge-like ethanol exposure during adolescence on open field behaviour in adult male rats.

PubMed

Yan, Wensheng; Kang, Jie; Zhang, Guoliang; Li, Shuangcheng; Kang, Yunxiao; Wang, Lei; Shi, Geming

2015-09-14

Binge drinking ethanol exposure during adolescence can lead to long-term neurobehavioural damage. It is not known whether the pubertal surge in testosterone that occurs during adolescence might impact the neurobehavioural effects of early ethanol exposure in adult animals. We examined this hypothesis by performing sham or gonadectomy surgeries on Sprague-Dawley rats around postnatal day (P) 23. From P28-65,the rats were administered 3.0g/kg ethanol using a binge-like model of exposure. Dependent measurements included tests of open field behaviour, blood ethanol concentrations, and testosterone levels. As adults, significant decreases in open field activity were observed in the GX rats. The open field behaviour of the GX rats was restored after testosterone administration. Binge-like ethanol exposure altered most of the parameters of the open field behaviour, suggestive of alcohol-induced anxiety, but rats treated with alcohol in combination with gonadectomy showed less motor behaviour and grooming behaviour and an increase in immobility, suggesting ethanol-induced depression. These results indicated that testosterone is required for ethanol-induced behavioural changes and that testicular hormones are potent stimulators of ethanol-induced behaviours. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Monitoring of piglets' open field activity and choice behaviour during the replay of maternal vocalization: a comparison between Observer and PID technique.

PubMed

Puppe, B; Schön, P C; Wendland, K

1999-07-01

The paper presents a new system for the automatic monitoring of open field activity and choice behaviour of medium-sized animals. Passive infrared motion detectors (PID) were linked on-line via a digital I/O interface to a personal computer provided with self-developed analysis software based on LabVIEW (PID technique). The set up was used for testing 18 one-week-old piglets (Sus scrofa) for their approach to their mother's nursing vocalization replayed through loudspeakers. The results were validated by comparison with a conventional Observer technique, a computer-aided direct observation. In most of the cases, no differences were seen between the Observer and PID technique regarding the percentage of stay in previously defined open field segments, the locomotor open field activity, and the choice behaviour. The results revealed that piglets are clearly attracted by their mother's nursing vocalization. The monitoring system presented in this study is thus suitable for detailed behavioural investigations of individual acoustic recognition. In general, the PID technique is a useful tool for research into the behaviour of individual animals in a restricted open field which does not rely on subjective analysis by a human observer.

Physical condition, sex, and age-class of eastern red-backed salamanders (Plethodon cinereus) in forested and open habitats of West Virginia, USA

Treesearch

Breanna L. Riedel; Kevin R. Russell; W. Mark Ford

2012-01-01

Nonforested habitats such as open fields and pastures have been considered unsuitable for desiccation-prone woodland salamanders such as the Eastern Red-backed Salamander (Plethodon cinereus). Recent research has suggested that Plethodon cinereus may not only disperse across but also reside within open habitats including fields,...

Covariant open bosonic string field theory on multiple D-branes in the proper-time gauge

NASA Astrophysics Data System (ADS)

Lee, Taejin

2017-12-01

We construct a covariant open bosonic string field theory on multiple D-branes, which reduces to a non-Abelian group Yang-Mills gauge theory in the zero-slope limit. Making use of the first quantized open bosonic string in the proper time gauge, we convert the string amplitudes given by the Polyakov path integrals on string world sheets into those of the second quantized theory. The world sheet diagrams generated by the constructed open string field theory are planar in contrast to those of the Witten's cubic string field theory. However, the constructed string field theory is yet equivalent to the Witten's cubic string field theory. Having obtained planar diagrams, we may adopt the light-cone string field theory technique to calculate the multi-string scattering amplitudes with an arbitrary number of external strings. We examine in detail the three-string vertex diagram and the effective four-string vertex diagrams generated perturbatively by the three-string vertex at tree level. In the zero-slope limit, the string scattering amplitudes are identified precisely as those of non-Abelian Yang-Mills gauge theory if the external states are chosen to be massless vector particles.

Characterization of stress-induced suppression of long-term potentiation in the hippocampal CA1 field of freely moving rats.

PubMed

Hirata, Riki; Togashi, Hiroko; Matsumoto, Machiko; Yamaguchi, Taku; Izumi, Takeshi; Yoshioka, Mitsuhiro

2008-08-21

Several lines of evidence have shown that exposure to stress impairs long-term potentiation (LTP) in the CA1 field of the hippocampus, but the detailed mechanisms for this effect remain to be clarified. The present study elucidated the synaptic mechanism of stress-induced LTP suppression in conscious, freely moving rats using electrophysiological approaches. Open field stress (i.e., novel environment stress) and elevated platform stress (i.e., uncontrollable stress) were employed. Basal synaptic transmission was significantly reduced during exposure to elevated platform stress but not during exposure to open field stress. LTP induction was blocked by elevated platform stress but not influenced by open field stress. Significant increases in serum corticosterone levels were observed in the elevated platform stress group compared with the open field stress group. Furthermore, LTP suppression induced by elevated platform stress was prevented by pretreatment with an anxiolytic drug diazepam (1 mg/kg, i.p.). These results suggest that stress-induced LTP suppression depends on the relative intensity of the stressor. The inhibitory synaptic response induced by an intense psychological stress, such as elevated platform stress, may be attributable to LTP impairment in the CA1 field of the hippocampus.

Open-field test site

NASA Astrophysics Data System (ADS)

Gyoda, Koichi; Shinozuka, Takashi

1995-06-01

An open-field test site with measurement equipment, a turn table, antenna positioners, and measurement auxiliary equipment was remodelled at the CRL north-site. This paper introduces the configuration, specifications and characteristics of this new open-field test site. Measured 3-m and 10-m site attenuations are in good agreement with theoretical values, and this means that this site is suitable for using 3-m and 10-m method EMI/EMC measurements. The site is expected to be effective for antenna measurement, antenna calibration, and studies on EMI/EMC measurement methods.

[Magnetotherapy designed to affect cervical sympathetic ganglia for the treatment of patients with primary open-angle glaucoma].

PubMed

Veselova, E V; Kamenskikh, T G; Raĭgorodkiĭ, Iu M; Kolbenev, I O; Myshkina, E S

2010-01-01

The traveling magnetic field was used to treat primary open-angle glaucoma. The field was applied to the projection of cervical sympathetic ganglia of the patients. Hemodynamic parameters of posterior short ciliary arteries and central retinal artery were analysed along with visual evoked potentials, visual field limits, and visual acuity. It was shown that magnetotherapy with the use of an AMO-ATOS apparatus produces better clinical results in patients with stage I and II primary open-angle glaucoma compared with medicamentous therapy (intake of trental tablets).

Lithium ameliorates open-field and elevated plus maze behaviors, and brain phospho-glycogen synthase kinase 3-beta expression in fragile X syndrome model mice.

PubMed

Chen, Xi; Sun, Weiwen; Pan, Ying; Yang, Quan; Cao, Kaiyi; Zhang, Jin; Zhang, Yizhi; Chen, Mincong; Chen, Feidi; Huang, Yueling; Dai, Lijun; Chen, Shengqiang

2013-10-01

To investigate whether lithium modifies open-field and elevated plus maze behavior, and brain phospho-glycogen synthase kinase 3 (P-GSK3beta) expression in Fmr1 knockout mice. One hundred and eighty FVB mice, including knockout and wild type, with an age of 30 days were used. An open-field and elevated plus maze was utilized to test behavior, while western blot was used to measure the P-GSK3beta expression. Six groups were formed: control (saline), lithium chloride 30, 60, 90, 120, and 200 mg/kg. The experiments were carried out in the Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China between January and June 2012. Lithium significantly decreased total distance, crossing, central area time, and center entry in the open-field test (p<0.05), and significantly reduced open-arm tracking, open-arm entry, and open-arm time in the elevated plus maze (p<0.05) in knockout mice. In wild type mice, significant changes were observed in both behavior tests in some treatment groups. Lithium ameliorated P-GSK3beta expression in the hippocampus of all the treatment groups in knockout mice (p<0.05). However, lithium did not modify either GSK3beta expression in tissues of knockout mice, or P-GSK3beta or GSK3beta expression in tissues of wild type mice. Lithium ameliorated open-field and elevated plus maze behaviors of Fmr1 knockout mice. This effect may be related to its enhancement of P-GSK3beta expression. Our findings suggest that lithium might have a therapeutic effect in fragile X syndrome.

Emotionality in growing pigs: is the open field a valid test?

PubMed

Donald, Ramona D; Healy, Susan D; Lawrence, Alistair B; Rutherford, Kenneth M D

2011-10-24

The ability to assess emotionality is important within animal welfare research. Yet, for farm animals, few tests of emotionality have been well validated. Here we investigated the construct validity of behavioural measures of pig emotionality in an open-field test by manipulating the experiences of pigs in three ways. In Experiment One (pharmacological manipulation), pigs pre-treated with Azaperone, a drug used to reduce stress in commercial pigs, were more active, spent more time exploring and vocalised less than control pigs. In Experiment Two (social manipulation), pigs that experienced the open-field arena with a familiar companion were also more exploratory, spent less time behaviourally idle, and were less vocal than controls although to a lesser degree than in Experiment One. In Experiment Three (novelty manipulation), pigs experiencing the open field for a second time were less active, explored less and vocalised less than they had done in the first exposure to the arena. A principal component analysis was conducted on data from all three trials. The first two components could be interpreted as relating to the form (cautious to exploratory) and magnitude (low to high arousal) of the emotional response to open-field testing. Based on these dimensions, in Experiment One, Azaperone pigs appeared to be less fearful than saline-treated controls. However, in Experiment Two, exposure to the arena with a conspecific did not affect the first two dimensions but did affect a third behavioural dimension, relating to oro-nasal exploration of the arena floor. In Experiment Three, repeat exposure altered the form but not the magnitude of emotional response: pigs were less exploratory in the second test. In conclusion, behavioural measures taken from pigs in an open-field test are sensitive to manipulations of their prior experience in a manner that suggests they reflect underlying emotionality. Behavioural measures taken during open-field exposure can be useful for making assessments of both pig emotionality and of their welfare. Copyright © 2011 Elsevier Inc. All rights reserved.

Beta Testing of CFD Code for the Analysis of Combustion Systems

NASA Technical Reports Server (NTRS)

Yee, Emma; Wey, Thomas

2015-01-01

A preliminary version of OpenNCC was tested to assess its accuracy in generating steady-state temperature fields for combustion systems at atmospheric conditions using three-dimensional tetrahedral meshes. Meshes were generated from a CAD model of a single-element lean-direct injection combustor, and the latest version of OpenNCC was used to calculate combustor temperature fields. OpenNCC was shown to be capable of generating sustainable reacting flames using a tetrahedral mesh, and the subsequent results were compared to experimental results. While nonreacting flow results closely matched experimental results, a significant discrepancy was present between the code's reacting flow results and experimental results. When wide air circulation regions with high velocities were present in the model, this appeared to create inaccurately high temperature fields. Conversely, low recirculation velocities caused low temperature profiles. These observations will aid in future modification of OpenNCC reacting flow input parameters to improve the accuracy of calculated temperature fields.

Evolution of space open electric arc burning in the external axial magnetic field

NASA Astrophysics Data System (ADS)

Urusova, I. R.; Urusova, T. E.

2018-06-01

The calculation was made for open DC electric arc burning in an external uniform axial magnetic field. It was performed within the framework of a nonstationary three-dimensional mathematical model in approximation of partial local thermodynamic equilibrium of plasma. A "schematic" analog of electron temperature fluctuations was proposed for numerical realization of the open electric arc column of a helical shape. According to calculations, it was established that the column of the open electric arc takes a helical space shape. Plasma rotates around a longitudinal axis of the arc, at that the directions of plasma rotation near the cathode and the anode are opposite. In the arc cross-sections, the velocity of plasma rotation is unequal and the deviation value of the same part of the arc from the central axis varies in time. A helical shape of the open arc is not stable and varies in time. Apparently, the open arc cannot remain stable and invariable in the time helical shape in the external axial magnetic field.

Field Evaluation of Open System Chambers for Measuring Whole Canopy Gas Exchanges

USDA-ARS?s Scientific Manuscript database

The ability to monitor whole canopy CO2 and H2O fluxes of crop plants in the field is needed for many research efforts ranging from plant breeding to the study of Climate Change effects on crops. Four portable, transparent, open system chambers for measuring canopy gas exchanges were field tested on...

Axisymmetric force-free magnetosphere in the exterior of a neutron star - II. Maximum storage and open field energies

NASA Astrophysics Data System (ADS)

Kojima, Yasufumi; Okamoto, Satoki

2018-04-01

A magnetar's magnetosphere gradually evolves by the injection of energy and helicity from the interior. Axisymmetric static solutions for a relativistic force-free magnetosphere with a power-law current model are numerically obtained. They provide information about the configurations in which the stored energy is large. The energy along a sequence of equilibria increases and becomes sufficient to open the magnetic field. A magnetic flux rope, in which a large amount of toroidal field is confined, is formed in the vicinity of the star, for states exceeding the open field energy. These states are energetically metastable, and the excess energy may be ejected as a magnetar outburst.

Behavior in the open field predicts the number of KCl-induced cortical spreading depressions in rats.

PubMed

Bogdanov, Volodymyr Borysovych; Bogdanova, Olena Viktorivna; Koulchitsky, Stanislav Vladimirovich; Chauvel, Virginie; Multon, Sylvie; Makarchuk, Mykola Yukhymovych; Brennan, Kevin Christopher; Renshaw, Perry Franklin; Schoenen, Jean

2013-01-01

Anxiety disorders are known to be comorbid with migraine, and cortical spreading depression (CSD) is the most likely cause of the migraine aura. To search for possible correlations between susceptibility to CSD and anxiety we used the open field test in male Sprague-Dawley rats chronically treated with the preventive anti-migraine drugs valproate or riboflavin. Animals avoiding the central area of the open field chamber and those with less exploratory activity (i.e. rearing) were considered more anxious. After 4 weeks of treatment CSDs were elicited by application of 1M KCl over the occipital cortex and the number of CSDs occurring over a 2h period was compared to the previously assessed open field behavior. Higher anxiety-like behavior was significantly correlated with a higher frequency of KCl-induced CSDs. In saline-treated animals, fewer rearings were found in animals with more frequent CSDs (R=-1.00). The duration of ambulatory episodes in the open field center correlated negatively with number of CSDs in the valproate group (R=-0.83; p<0.005) and in riboflavin treated group (R=-0.69; p<0.05) as well as total time spent in the open field center in both groups (R=-0.75; p<0.05 and R=-0.58; p<0.1 respectively). These results suggest that anxiety symptoms are associated with susceptibility to CSD and might explain why it can be an aggravating factor in migraine with aura. Copyright © 2012 Elsevier B.V. All rights reserved.

Modeling and simulation for the field emission of carbon nanotubes array

NASA Astrophysics Data System (ADS)

Wang, X. Q.; Wang, M.; Ge, H. L.; Chen, Q.; Xu, Y. B.

2005-12-01

To optimize the field emission of the infinite carbon nanotubes (CNTs) array on a planar cathode surface, the numerical simulation for the behavior of field emission with finite difference method was proposed. By solving the Laplace equation with computer, the influence of the intertube distance, the anode-cathode distance and the opened/capped CNT on the field emission of CNTs array were taken into account, and the results could accord well with the experiments. The simulated results proved that the field enhancement factor of individual CNT is largest, but the emission current density is little. Due to the enhanced screening of the electric field, the enhancement factor of CNTs array decreases with decreasing the intertube distance. From the simulation the field emission can be optimized when the intertube distance is close to the tube height. The anode-cathode distance hardly influences the field enhancement factor of CNTs array, but can low the threshold voltage by decreasing the anode-cathode distance. Finally, the distribution of potential of the capped CNTs array and the opened CNTs array was simulated, which the results showed that the distribution of potential can be influenced to some extent by the anode-cathode distance, especially at the apex of the capped CNTs array and the brim of the opened CNTs array. The opened CNTs array has larger field enhancement factor and can emit more current than the capped one.

Quasiopen inflation

NASA Astrophysics Data System (ADS)

García-Bellido, Juan; Garriga, Jaume; Montes, Xavier

1998-04-01

We show that a large class of two-field models of single-bubble open inflation does not lead to infinite open universes, as was previously thought, but to an ensemble of very large but finite inflating ``islands.'' The reason is that the quantum tunneling responsible for the nucleation of the bubble does not occur simultaneously along both field directions and equal-time hypersurfaces in the open universe are not synchronized with equal-density or fixed-field hypersurfaces. The most probable tunneling trajectory corresponds to a zero value of the inflaton field; large values, necessary for the second period of inflation inside the bubble, only arise as localized fluctuations. The interior of each nucleated bubble will contain an infinite number of such inflating regions of comoving size of order γ-1, where γ is the supercurvature eigenvalue, which depends on the parameters of the model. Each one of these islands will be a quasi-open universe. Since the volume of the hyperboloid is infinite, inflating islands with all possible values of the field at their center will be realized inside of a single bubble. We may happen to live in one of those patches of comoving size d<~γ-1, where the universe appears to be open. In particular, we consider the ``supernatural'' model proposed by Linde and Mezhlumian. There, an approximate U(1) symmetry is broken by a tunneling field in a first order phase transition, and slow-roll inflation inside the nucleated bubble is driven by the pseudo Goldstone field. We find that the excitations of the pseudo Goldstone field produced by the nucleation and subsequent expansion of the bubble place severe constraints on this model. We also discuss the coupled and uncoupled two-field models.

Field-antifield and BFV formalisms for quadratic systems with open gauge algebras

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nirov, K.S.; Razumov, A.V.

1992-09-20

In this paper the Lagrangian field-antifield (BV) and Hamiltonian (BFV) BRST formalisms for the general quadratic systems with open gauge algebra are considered. The equivalence between the Lagrangian and Hamiltonian formalisms is proven.

Evidence for open field lines in Jupiter's magnetosphere

NASA Technical Reports Server (NTRS)

Goertz, C. K.; Randall, B. A.; Thomsen, M. F.; Jones, D. E.; Smith, E. J.

1976-01-01

A model for the night-side Jovian magnetic field is derived partly on the basis of theoretical considerations and partly on the basis of the magnetic-field data obtained during the outbound leg of the path of Pioneer 10. This model can explain the observed sawtooth modulation of energetic particle fluxes in terms of closed and open field lines that cannot contain the particles. The model is applicable only to the Jovian magnetotail.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pern, F.J.; Eisgruber, I.L.; Micheels, R.H.

The effects of ethylene-vinyl acetate (EVA) discoloration due to accelerated field or laboratory exposure on the encapsulated silicon (Si) solar cells or EVA/glass laminates were characterized quantitatively by using non-invasive, non-destructive ultraviolet-visible (UV-vis) spectrophotometry, spectrocolorimetry, spectrofluorometry, scanning laser OBIC (optical beam induced current) spectroscopy, and current-voltage (I-V) and quantum efficiency (QE) measurements. The results show that the yellowness index (YI) measured directly over the AR-coated solar cells under the glass superstrate increased from the range of {minus}80 to {minus}90 to the range of {minus}20 to 15 as the EVA changed from clear to brown. The ratio of two fluorescence emissionmore » peak areas generally increased from 1.45 to 5.69 as browning increased, but dropped to 4.21 on a darker EVA. For a solar cell with brown EVA in the central region, small-area grating QE measurements and scanning laser OBIC analysis between the brown and clear EVA regions showed that the quantum efficiency loss at 633 nm was 42%--48% of the loss at 488 nm, due to a reduced decrease of transmittance in browned EVA at the longer wavelengths. The portion of the solar cell under the browned EVA showed a decrease of {approximately}36% in efficiency, as compared to the cell efficiency under clear EVA. Transmittance loss at 633 nm was 38% of the loss at 488 nm for a light yellow-brown EVA/glass laminate that showed a small increase of 10 in the yellowness index.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pern, F.J.; Eisgruber, I.L.; Micheels, R.H.

The effects of ethylene-vinyl acetate (EVA) discoloration due to accelerated field or laboratory exposure on the encapsulated silicon (Si) solar cells or EVA/glass laminates were characterized quantitatively by using non-invasive, non-destructive ultraviolet-visible (UV-vis) spectrophotometry, spectrocolorimetry, spectrofluorometry, scanning laser OBIC (optical beam induced current) spectroscopy, and current-voltage (I-V) and quantum efficiency (QE) measurements. The results show that the yellowness index (YI) measured directly over the AR-coated solar cells under the glass superstrate increased from the range of -80 to -90 to the range of -20 to 15 as the EVA changed from clear to brown. The ratio of two fluorescence emissionmore » peak areas generally increased from 1.45 to 5.69 as browning increased, but dropped to 4.21 on a darker EVA. For a solar cell with brown EVA in the central region, small-area grating QE measurements and scanning laser OBIC analysis between the brown and clear EVA regions showed that the quantum efficiency loss at 633 nm was 42%-48% of the loss at 488 nm, due to a reduced decrease of transmittance in browned EVA at the longer wavelengths. The portion of the solar cell under the browned EVA showed a decrease of {approximately}36% in efficiency, as compared to the cell efficiency under clear EVA. Transmittance loss at 633 nm was 38% of the loss at 488 nm for a light yellow-brown EVA/glass laminate that showed a small increase of 10 in the yellowness index.« less

Re-Invigorating Openness at The Open University: The Role of Open Educational Resources

ERIC Educational Resources Information Center

Gourley, Brenda; Lane, Andy

2009-01-01

This paper describes the internal motivations and external drivers that led The Open University UK to enter the field of Open Educational Resources through its institution-wide OpenLearn initiative (www.open.ac.uk/openlearn). It also describes some of the emerging evidence of the impacts inside and outside the university. Through the rapid…

PREFACE: Proceedings of the 7th Edoardo Amaldi Conference on Gravitational Waves (Amaldi7), Sydney Convention and Exhibition Centre, Darling Harbour, Sydney, Australia, 8 14 July 2007

NASA Astrophysics Data System (ADS)

Scott, Susan M.; McClelland, David E.

2008-07-01

At GR17 in Dublin in 2004, it was decided to hold GR18 in Sydney in 2007. Every six years, the GR conference (held every three years) and Amaldi meeting (held every two years) occur in the same year around July. This was to be the case in 2007. By mutual agreement of the International Society on General Relativity and Gravitation (ISGRG), which oversees the GR conferences and The Gravitational Wave International Committee (GWIC), which oversees the Amaldi meetings, it was decided to hold these two important conferences concurrently, for the first time, at the same venue, namely Sydney. At a time when the gravitational wave community was beginning to explore the possibility of searches to probe various aspects of the theory, the vision was to bring that community together with the community of gravitational theorists in order to better appreciate the work being done by both parties and to explore possibilities for future research using the mutual expertise. The logistics of running two such large meetings concurrently were considerable. The format agreed upon by the ISGRG and GWIC was the following: common plenary sessions in the mornings from Monday to Friday; six parallel GR workshop sessions and an Amaldi session each afternoon from Monday to Friday (except Wednesday); a combined poster session on Wednesday; a full day of Amaldi sessions on the final day (Saturday). The scientific programme for GR18 was overseen by a Scientific Organising Committee established by the ISGRG and chaired by Professor Sathyaprakash. The scientific programme for Amaldi7 was overseen by GWIC chaired by Professor Cerdonio. One of the highlights of the conferences was the breadth and quality of the plenary programme put together by the scientific committees. Not only did these talks give an excellent snapshot of the entire field at this time, but they also explored the interfaces with other related fields, which proved of special interest to participants. We were given superb overviews of the state of the art of: observational handles on dark energy; collider physics experiments designed to probe cosmology; gravitational dynamics of large stellar systems; and the use of analogue condensed-matter systems in the laboratory to investigate black hole event horizons. In the more mainstream areas we were given timely reviews of: the Gravity Probe B and STEP missions; quasi-local black hole horizons and their applications; cosmic censorship; the spin foam model approach to quantum gravity; the causal dynamical triangulations approach to quantum gravity; superstring theory applied to questions in particle physics; the current status and prospects for gravitational wave astronomy; ground-based gravitational wave detection; and technology developments for the future LISA mission. A special issue of Classical and Quantum Gravity (Volume 25, Number 11, 7 June 2008) is published as the proceedings of GR18 and Amaldi7. It contains the overview articles by the plenary speakers, the summaries of each GR18 workshop parallel session as provided by the workshop chairs, and the highlights of the Amaldi7 meeting as selected by the Amaldi7 chairs. Other Amaldi7 talks and posters appear in this refereed issue of the electronic Journal of Physics: Conference Series. This issue of JPCS and the CQG Special Issue are electronically linked. The conference organisers would like to acknowledge the financial support of: The Australian National University; IUPAP; The Australian Institute of Physics; BHP Billiton; The University of Western Australia; The University of New South Wales; The Institute of Physics; The Gravity Research Foundation; SGI; CosNet; The Australian Mathematical Sciences Institute; Springer; Duraduct; the New South Wales Government; The Australasian Society for General Relativity and Gravitation; the Mexican GR bid; the Centre for Precision Optics; The Anglo-Australian Observatory; Newspec; CSIRO; and The University of Melbourne. We would like to thank the GR18 Scientific Organising Committee, GWIC and the Local Organising Committee for all their hard work in putting together these very successful combined conferences, which attracted 520 participants. Many of the practical aspects of the organisation were handled by the event management company Conexion, and their professionalism, expertise and dedication were greatly appreciated. Finally, we would like to thank all the participants for their lively and colourful contributions to making these conferences a success. Susan M Scott Chair, Local Organising Committee David E McClelland Deputy Chair, Local Organising Committee Centre for Gravitational Physics, The Australian National University, Australia Guest Editors Participants gather prior to opening ceremony Participants gather prior to opening ceremony Participants entering auditorium for opening ceremony Participants entering auditorium for opening ceremony Chair of Local Organising Committee Susan M Scott opening ceremony Chair of Local Organising Committee Susan M Scott opening ceremony President of the International Society on General Relativity and Gravitation Clifford M Will opening ceremony President of the International Society on General Relativity and Gravitation Clifford M Will opening ceremony Amusing moment at opening ceremony Amusing moment at opening ceremony Chair of the Gravitational Wave International Committee James Hough opening ceremony Chair of the Gravitational Wave International Committee James Hough opening ceremony Welcome to the land by traditional land owner Welcome to the land by traditional land owner Welcome to the land by traditional land owner Welcome to the land by traditional land owner First plenary speaker Stan E Whitcomb First plenary speaker Stan E Whitcomb Exhibition booth Australian National University College of Science Kimberley Heenan (left), Lachlan McCalman (right) Exhibition booth Australian National University College of Science Kimberley Heenan (left), Lachlan McCalman (right) Exhibition booth Springer Exhibition booth Springer Exhibition booth GR19 Mexico City Exhibition booth GR19 Mexico City Amaldi7 posters Amaldi7 posters Participants gather before Kip Thorne's public lecture Participants gather before Kip Thorne's public lecture Participants gather before Kip Thorne's public lecture Participants gather before Kip Thorne's public lecture Entering auditorium for Kip Thorne's public lecture Entering auditorium for Kip Thorne's public lecture Public lecture by Kip Thorne Public lecture by Kip Thorne Public lecture by Kip Thorne Public lecture by Kip Thorne Kip Thorne public lecture Kip Thorne public lecture Kip Thorne public lecture Kip Thorne public lecture Roger Penrose (left), Adam Spencer (right) Roger Penrose (left), Adam Spencer (right) From left to right: John Steele, Susan Scott, Roger Penrose, David McClelland, John Webb, Adam Spencer From left to right: John Steele, Susan Scott, Roger Penrose, David McClelland, John Webb, Adam Spencer Opening of Roger Penrose's public lecture from left to right: John Webb, Adam Spencer, Roger Penrose Opening of Roger Penrose's public lecture from left to right: John Webb, Adam Spencer, Roger Penrose Roger Penrose at opening of his public lecture Roger Penrose at opening of his public lecture Public lecture by Roger Penrose Public lecture by Roger Penrose Public lecture by Roger Penrose Public lecture by Roger Penrose

Differences between the quality of strawberries (Fragaria x ananassa) pollinated by the stingless bees Scaptotrigona aff. depilis and Nannotrigona testaceicornis.

PubMed

Roselino, A C; Santos, S B; Hrncir, M; Bego, L R

2009-05-12

We investigated the success of two stingless bee species in pollinating strawberries in greenhouses. Three greenhouses and one open field area were used; one greenhouse had only strawberry plants (control), another (G1) had three colonies of Scaptotrigona aff. depilis and another (G2) had three colonies of Nannotrigona testaceicornis. In the open field area, the flowers could be visited by any bee. The total production of fruits was counted and a random sample (N = 100) from each area was used to measure weight, length, circumference, and achenes number (N = 5). The percentages of deformed strawberries were: 23% (no bees); 2% (greenhouses with bees) and 13% (open field). The strawberries from the greenhouse with N. testaceicornis and the open field were heavier than those from the greenhouses with no bees and with S. depilis. The fruit circumference was largest in the greenhouses with bees. The achenes number did not differ among the experimental areas. The strawberries produced in the greenhouses with stingless bees had more quality and greater commercial value than the fruits produced in the open field area and the greenhouse without bees. We conclude that stingless bees are efficient pollinators of strawberry flowers cultivated in greenhouses.

Antioxidant effects of nerolidol in mice hippocampus after open field test.

PubMed

Nogueira Neto, José Damasceno; de Almeida, Antonia Amanda Cardoso; da Silva Oliveira, Johanssy; Dos Santos, Pauline Sousa; de Sousa, Damião Pergentino; de Freitas, Rivelilson Mendes

2013-09-01

The aim of this study was to evaluate the neuroprotective effects of nerolidol in mice hippocampus against oxidative stress in neuronal cells compared to ascorbic acid (positive control) as well as evaluated the nerolidol sedative effects by open field test compared to diazepam (positive control). Thirty minutes prior to behavioral observation on open field test, mice were intraperitoneally treated with vehicle, nerolidol (25, 50 and 75 mg/kg), diazepam (1 mg/kg) or ascorbic acid (250 mg/kg). To clarify the action mechanism of of nerolidol on oxidative stress in animals subjected to the open field test, Western blot analysis of Mn-superoxide dismutase and catalase in mice hippocampus were performed. In nerolidol group, there was a significant decrease in lipid peroxidation and nitrite levels when compared to negative control (vehicle). However, a significant increase was observed in superoxide dismutase and catalase activities in this group when compared to the other groups. Vehicle, diazepam, ascorbic acid and nerolidol groups did not affected Mn-superoxide dismutase, catalase mRNA or protein levels. Our findings strongly support the hypothesis that oxidative stress occurs in hippocampus. Nerolidol showed sedative effects in animals subjected to the open field test. Oxidative process plays a crucial role on neuronal pathological consequence, and implies that antioxidant effects could be achieved using this sesquiterpene.

Identifying a cooperative control mechanism between an applied field and the environment of open quantum systems

NASA Astrophysics Data System (ADS)

Gao, Fang; Rey-de-Castro, Roberto; Wang, Yaoxiong; Rabitz, Herschel; Shuang, Feng

2016-05-01

Many systems under control with an applied field also interact with the surrounding environment. Understanding the control mechanisms has remained a challenge, especially the role played by the interaction between the field and the environment. In order to address this need, here we expand the scope of the Hamiltonian-encoding and observable-decoding (HE-OD) technique. HE-OD was originally introduced as a theoretical and experimental tool for revealing the mechanism induced by control fields in closed quantum systems. The results of open-system HE-OD analysis presented here provide quantitative mechanistic insights into the roles played by a Markovian environment. Two model open quantum systems are considered for illustration. In these systems, transitions are induced by either an applied field linked to a dipole operator or Lindblad operators coupled to the system. For modest control yields, the HE-OD results clearly show distinct cooperation between the dynamics induced by the optimal field and the environment. Although the HE-OD methodology introduced here is considered in simulations, it has an analogous direct experimental formulation, which we suggest may be applied to open systems in the laboratory to reveal mechanistic insights.

Open field locomotor activity and anxiety-related behaviors in mucopolysaccharidosis type IIIA mice.

PubMed

Lau, Adeline A; Crawley, Allison C; Hopwood, John J; Hemsley, Kim M

2008-08-05

Mucopolysaccharidosis (MPS) IIIA, or Sanfilippo syndrome, is a lysosomal storage disorder characterized by severe and progressive neuropathology. Following an asymptomatic period, patients may present with sleep disturbances, cognitive decline, aggressive tendencies and hyperactivity. A naturally-occurring mouse model of MPS IIIA also exhibits many of these behavioral features and has been recently back-crossed onto a C57BL/6 genetic background. To more thoroughly characterize the behavioral phenotype of congenic MPS IIIA mice, we assessed exploratory activity and unconditioned anxiety-related behavior in the elevated plus maze (EPM) and open field locomotor activity. Although MPS IIIA male mice were less active in the EPM at 18 and 20 weeks of age, they were more likely to explore the open arms than their normal counter-parts suggesting reduced anxiety. Repeated EPM testing reduced exploration of the open arms in MPS IIIA mice. In the open field test, significant reductions in activity were evident in naïve-tested male MPS IIIA mice from 10 weeks of age. Female normal and MPS IIIA mice displayed similar exploratory activity in the open field test. These differences in anxiety and locomotor activity will allow us to evaluate the efficacy of therapeutic regimes for MPS IIIA as a forerunner to developing safe and effective therapies for Sanfilippo patients.

The same frequency of planets inside and outside open clusters of stars.

PubMed

Meibom, Søren; Torres, Guillermo; Fressin, Francois; Latham, David W; Rowe, Jason F; Ciardi, David R; Bryson, Steven T; Rogers, Leslie A; Henze, Christopher E; Janes, Kenneth; Barnes, Sydney A; Marcy, Geoffrey W; Isaacson, Howard; Fischer, Debra A; Howell, Steve B; Horch, Elliott P; Jenkins, Jon M; Schuler, Simon C; Crepp, Justin

2013-07-04

Most stars and their planets form in open clusters. Over 95 per cent of such clusters have stellar densities too low (less than a hundred stars per cubic parsec) to withstand internal and external dynamical stresses and fall apart within a few hundred million years. Older open clusters have survived by virtue of being richer and denser in stars (1,000 to 10,000 per cubic parsec) when they formed. Such clusters represent a stellar environment very different from the birthplace of the Sun and other planet-hosting field stars. So far more than 800 planets have been found around Sun-like stars in the field. The field planets are usually the size of Neptune or smaller. In contrast, only four planets have been found orbiting stars in open clusters, all with masses similar to or greater than that of Jupiter. Here we report observations of the transits of two Sun-like stars by planets smaller than Neptune in the billion-year-old open cluster NGC6811. This demonstrates that small planets can form and survive in a dense cluster environment, and implies that the frequency and properties of planets in open clusters are consistent with those of planets around field stars in the Galaxy.

Myocardial infarction increases progressive visual field defects in well treated early primary open angle glaucoma--a prospective case control study.

PubMed

Mondal, Lakshmikanta; Baidya, Krishnapada; Choudhury, Himadri; Roy, Rupam

2013-06-01

The purpose of the study was to evaluate the progression of glaucomatous field damage in patients with stable primary open angle glaucoma after an attack of myocardial infarction. In this case control study, 62 open angle glaucoma patients were selected and regularly followed up. Among 62 patients, 9 had an attack of myocardial infarction. The intra-ocular pressure and visual field progression of both the groups (myocardial infarction versus no myocardial infarction) were analysed. Three (33.3%) out of 9 patients who had suffered from myocardial infarction showed progressive visual field loss whereas only 9 (16.9%) out of 53 patients who did not suffer from myocardial infarction, showed progressive field changes. Both the groups had stable target intra-ocular pressure between 14 and 16 mm Hg. Myocardial infarction may adversely influence the progression of primary open angle glaucoma which is suspected to result from ischaemia induced neuronal loss and only control of intraocular pressure is not the only solution. We have to look for other drugs that prevents ischaemia induced neuronal damage.

The source of the electric field in the nightside magnetosphere

NASA Technical Reports Server (NTRS)

Stern, D. P.

1975-01-01

In the open magnetosphere model magnetic field lines from the polar caps connect to the interplanetary magnetic field and conduct an electric field from interplanetary space to the polar ionosphere. By examining the magnetic flux involved it is concluded that only slightly more than half of the magnetic flux in the polar caps belongs to open field lines and that such field lines enter or leave the magnetosphere through narrow elongated windows stretching the tail. These window regions are identified with the tail's boundary region and shift their position with changes in the interplanetary magnetic field, in particular when a change of interplanetary magnetic sector occurs. The circuit providing electric current in the magnetopause and the plasma sheet is extended across those windows; thus energy is drained from the interplanetary electric field and an electric potential drop is produced across the plasma sheet. The polar cap receives its electric field from interplanetary space on the day side from open magnetic field lines and on the night side from closed field lines leading to the plasma sheet. The theory described provides improved understanding of magnetic flux bookkeeping, of the origin of Birkeland currents, and of the boundary layer of the geomagnetic tail.

Focused feasibility study for surface soil at the main pits and pushout area, J-field toxic burning pits area, Aberdeen Proving Ground, Maryland

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patton, T.; Benioff, P.; Biang, C.

1996-06-01

The Environmental Management Division of Aberdeen Proving Ground (APG), Maryland, is conducting a remedial investigation and feasibility study of the J-Field area at APG pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act, as amended (CERCLA). J-Field is located within the Edgewood Area of APG in Harford County, Maryland. Since World War II, activities in the Edgewood Area have included the development, manufacture, testing, and destruction of chemical agents and munitions. These materials were destroyed at J-Field by open burning/open detonation. Portions of J-Field continue to be used for the detonation and disposal of unexploded ordnance (UXO) by openmore » burning/open detonation under authority of the Resource Conservation and Recovery Act.« less

A System for Open-Access 3He Human Lung Imaging at Very Low Field

PubMed Central

RUSET, I.C.; TSAI, L.L.; MAIR, R.W.; PATZ, S.; HROVAT, M.I.; ROSEN, M.S.; MURADIAN, I.; NG, J.; TOPULOS, G.P.; BUTLER, J.P.; WALSWORTH, R.L.; HERSMAN, F.W.

2010-01-01

We describe a prototype system built to allow open-access very-low-field MRI of human lungs using laser-polarized 3He gas. The system employs an open four-coil electromagnet with an operational B0 field of 4 mT, and planar gradient coils that generate gradient fields up to 0.18 G/cm in the x and y direction and 0.41 G/cm in the z direction. This system was used to obtain 1H and 3He phantom images and supine and upright 3He images of human lungs. We include discussion on challenges unique to imaging at 50 –200 kHz, including noise filtering and compensation for narrow-bandwidth coils. PMID:20354575

A Human Open Field Test Reveals Thigmotaxis Related to Agoraphobic Fear.

PubMed

Walz, Nora; Mühlberger, Andreas; Pauli, Paul

2016-09-01

Thigmotaxis refers to a specific behavior of animals (i.e., to stay close to walls when exploring an open space). Such behavior can be assessed with the open field test (OFT), which is a well-established indicator of animal fear. The detection of similar open field behavior in humans may verify the translational validity of this paradigm. Enhanced thigmotaxis related to anxiety may suggest the relevance of such behavior for anxiety disorders, especially agoraphobia. A global positioning system was used to analyze the behavior of 16 patients with agoraphobia and 18 healthy individuals with a risk for agoraphobia (i.e., high anxiety sensitivity) during a human OFT and compare it with appropriate control groups (n = 16 and n = 19). We also tracked 17 patients with agoraphobia and 17 control participants during a city walk that involved walking through an open market square. Our human OFT triggered thigmotaxis in participants; patients with agoraphobia and participants with high anxiety sensitivity exhibited enhanced thigmotaxis. This behavior was evident in increased movement lengths along the wall of the natural open field and fewer entries into the center of the field despite normal movement speed and length. Furthermore, participants avoided passing through the market square during the city walk, indicating again that thigmotaxis is related to agoraphobia. This study is the first to our knowledge to verify the translational validity of the OFT and to reveal that thigmotaxis, an evolutionarily adaptive behavior shown by most species, is related to agoraphobia, a pathologic fear of open spaces, and anxiety sensitivity, a risk factor for agoraphobia. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

The stimulatory effects of caffeine with oseltamivir (Tamiflu) on light-dark behavior and open-field behavior in mice.

PubMed

Uchiyama, Hidemori; Toda, Akihisa; Imoto, Masumi; Nishimura, Satoko; Kuroki, Hiroaki; Soeda, Shinji; Shimeno, Hiroshi; Watanabe, Shigenori; Eyanagi, Reiko

2010-01-22

Abnormal behaviors and death associated with the use of oseltamivir (Tamiflu) have emerged as a major issue in influenza patients taking the drug. Here, we investigated the mechanisms underlying the effects of oseltamivir on the behavior of mice using light-dark and open-field preference tests. Oseltamivir (75 and 150 mg/kg, intraperitoneally (i.p.)) alone affected neither time spent in the open area in the light-dark preference test nor ambulation in the open-field test at 2h post-injection. However, a non-selective adenosine A(1)/A(2) receptor antagonist, caffeine (10mg/kg, i.p.) in combination with oseltamivir (150 mg/kg, i.p.) increased time spent in the open area in the light-dark preference test. This enhancement was not inhibited by a benzodiazepine receptor antagonist, flumazenil (10-20mg/kg, subcutaneously (s.c.)). Enhancement of ambulation in the open-field test was also observed when caffeine (10mg/kg, i.p.) was combined with oseltamivir (150 mg/kg, i.p.). This enhancement was inhibited by a dopamine D(2) receptor antagonist, haloperidol (0.1mg/kg, s.c.). Furthermore, an adenosine A(2) receptor antagonist, SCH58261 (3mg/kg, i.p.) in combination with oseltamivir (150 mg/kg, i.p.) increased ambulation in the open-field test, while an adenosine A(1) receptor antagonist, DPCPX (1-3mg/kg, i.p.) did not. These findings suggest that the actions of oseltamivir may involve the dopamine and adenosine systems. Our findings suggest that due to the interaction between central blockade of adenosine A(2) receptors by caffeine, and oseltamivir-induced behavioral changes, patients being treated with oseltamivir should be closely monitored. (c) 2009 Elsevier Ireland Ltd. All rights reserved.

Exploratory behaviour in the open field test adapted for larval zebrafish: impact of environmental complexity.

PubMed

Ahmad, Farooq; Richardson, Michael K

2013-01-01

This study aimed to develop and characterize a novel (standard) open field test adapted for larval zebrafish. We also developed and characterized a variant of the same assay consisting of a colour-enriched open field; this was used to assess the impact of environmental complexity on patterns of exploratory behaviours as well to determine natural colour preference/avoidance. We report the following main findings: (1) zebrafish larvae display characteristic patterns of exploratory behaviours in the standard open field, such as thigmotaxis/centre avoidance; (2) environmental complexity (i.e. presence of colours) differentially affects patterns of exploratory behaviours and greatly attenuates natural zone preference; (3) larvae displayed the ability to discriminate colours. As reported previously in adult zebrafish, larvae showed avoidance towards blue and black; however, in contrast to the reported adult behaviour, larvae displayed avoidance towards red. Avoidance towards yellow and preference for green and orange are shown for the first time, (4) compared to standard open field tests, exposure to the colour-enriched open field resulted in an enhanced expression of anxiety-like behaviours. To conclude, we not only developed and adapted a traditional rodent behavioural assay that serves as a gold standard in preclinical drug screening, but we also provide a version of the same test that affords the possibility to investigate the impact of environmental stress on behaviour in larval zebrafish while representing the first test for assessment of natural colour preference/avoidance in larval zebrafish. In the future, these assays will improve preclinical drug screening methodologies towards the goal to uncover novel drugs. This article is part of a Special Issue entitled: insert SI title. Copyright © 2012 Elsevier B.V. All rights reserved.

Open Content in Open Context

ERIC Educational Resources Information Center

Kansa, Sarah Whitcher; Kansa, Eric C.

2007-01-01

This article presents the challenges and rewards of sharing research content through a discussion of Open Context, a new open access data publication system for field sciences and museum collections. Open Context is the first data repository of its kind, allowing self-publication of research data, community commentary through tagging, and clear…

Apparatus for efficient sidewall containment of molten metal with horizontal alternating magnetic fields utilizing a ferromagnetic dam

DOEpatents

Praeg, Walter F.

1997-01-01

An apparatus for casting sheets of metal from molten metal. The apparatus includes a containment structure having an open side, a horizontal alternating magnetic field generating structure and a ferromagnetic dam. The magnetic field and the ferromagnetic dam contain the molten metal from leaking out side portions of the open side of the containment structure.

Marine Corps Recruits: A Historical Look at Accessions and Bootcamp Performance

DTIC Science & Technology

2010-09-01

without the promise of an occupational field . Their code is PN, and these are called open contracts. In this slide, we graph the percentage of open ...means that occupational specialties such as infantry, armor, field artillery, and short-range air defense artillery are closed to women...enlistment contracts began for small numbers of Marines. While the 3 -, 4-, and 6-year initial enlistment contracts were open to the same group of MOSs

First LIGO search for gravitational wave bursts from cosmic (super)strings

NASA Astrophysics Data System (ADS)

Abbott, B. P.; Abbott, R.; Adhikari, R.; Ajith, P.; Allen, B.; Allen, G.; Amin, R. S.; Anderson, S. B.; Anderson, W. G.; Arain, M. A.; Araya, M.; Armandula, H.; Armor, P.; Aso, Y.; Aston, S.; Aufmuth, P.; Aulbert, C.; Babak, S.; Baker, P.; Ballmer, S.; Barker, C.; Barker, D.; Barr, B.; Barriga, P.; Barsotti, L.; Barton, M. A.; Bartos, I.; Bassiri, R.; Bastarrika, M.; Behnke, B.; Benacquista, M.; Betzwieser, J.; Beyersdorf, P. T.; Bilenko, I. A.; Billingsley, G.; Biswas, R.; Black, E.; Blackburn, J. K.; Blackburn, L.; Blair, D.; Bland, B.; Bodiya, T. P.; Bogue, L.; Bork, R.; Boschi, V.; Bose, S.; Brady, P. R.; Braginsky, V. B.; Brau, J. E.; Bridges, D. O.; Brinkmann, M.; Brooks, A. F.; Brown, D. A.; Brummit, A.; Brunet, G.; Bullington, A.; Buonanno, A.; Burmeister, O.; Byer, R. L.; Cadonati, L.; Camp, J. B.; Cannizzo, J.; Cannon, K. C.; Cao, J.; Cardenas, L.; Caride, S.; Castaldi, G.; Caudill, S.; Cavaglià, M.; Cepeda, C.; Chalermsongsak, T.; Chalkley, E.; Charlton, P.; Chatterji, S.; Chelkowski, S.; Chen, Y.; Christensen, N.; Chung, C. T. Y.; Clark, D.; Clark, J.; Clayton, J. H.; Cokelaer, T.; Colacino, C. N.; Conte, R.; Cook, D.; Corbitt, T. R. C.; Cornish, N.; Coward, D.; Coyne, D. C.; Creighton, J. D. E.; Creighton, T. D.; Cruise, A. M.; Culter, R. M.; Cumming, A.; Cunningham, L.; Danilishin, S. L.; Danzmann, K.; Daudert, B.; Davies, G.; Daw, E. J.; Debra, D.; Degallaix, J.; Dergachev, V.; Desai, S.; Desalvo, R.; Dhurandhar, S.; Díaz, M.; Dietz, A.; Donovan, F.; Dooley, K. L.; Doomes, E. E.; Drever, R. W. P.; Dueck, J.; Duke, I.; Dumas, J.-C.; Dwyer, J. G.; Echols, C.; Edgar, M.; Effler, A.; Ehrens, P.; Espinoza, E.; Etzel, T.; Evans, M.; Evans, T.; Fairhurst, S.; Faltas, Y.; Fan, Y.; Fazi, D.; Fehrmann, H.; Finn, L. S.; Flasch, K.; Foley, S.; Forrest, C.; Fotopoulos, N.; Franzen, A.; Frede, M.; Frei, M.; Frei, Z.; Freise, A.; Frey, R.; Fricke, T.; Fritschel, P.; Frolov, V. V.; Fyffe, M.; Galdi, V.; Garofoli, J. A.; Gholami, I.; Giaime, J. A.; Giampanis, S.; Giardina, K. D.; Goda, K.; Goetz, E.; Goggin, L. M.; González, G.; Gorodetsky, M. L.; Goßler, S.; Gouaty, R.; Grant, A.; Gras, S.; Gray, C.; Gray, M.; Greenhalgh, R. J. S.; Gretarsson, A. M.; Grimaldi, F.; Grosso, R.; Grote, H.; Grunewald, S.; Guenther, M.; Gustafson, E. K.; Gustafson, R.; Hage, B.; Hallam, J. M.; Hammer, D.; Hammond, G. D.; Hanna, C.; Hanson, J.; Harms, J.; Harry, G. M.; Harry, I. W.; Harstad, E. D.; Haughian, K.; Hayama, K.; Heefner, J.; Heng, I. S.; Heptonstall, A.; Hewitson, M.; Hild, S.; Hirose, E.; Hoak, D.; Hodge, K. A.; Holt, K.; Hosken, D. J.; Hough, J.; Hoyland, D.; Hughey, B.; Huttner, S. H.; Ingram, D. R.; Isogai, T.; Ito, M.; Ivanov, A.; Johnson, B.; Johnson, W. W.; Jones, D. I.; Jones, G.; Jones, R.; Ju, L.; Kalmus, P.; Kalogera, V.; Kandhasamy, S.; Kanner, J.; Kasprzyk, D.; Katsavounidis, E.; Kawabe, K.; Kawamura, S.; Kawazoe, F.; Kells, W.; Keppel, D. G.; Khalaidovski, A.; Khalili, F. Y.; Khan, R.; Khazanov, E.; King, P.; Kissel, J. S.; Klimenko, S.; Kokeyama, K.; Kondrashov, V.; Kopparapu, R.; Koranda, S.; Kozak, D.; Krishnan, B.; Kumar, R.; Kwee, P.; Lam, P. K.; Landry, M.; Lantz, B.; Lazzarini, A.; Lei, H.; Lei, M.; Leindecker, N.; Leonor, I.; Li, C.; Lin, H.; Lindquist, P. E.; Littenberg, T. B.; Lockerbie, N. A.; Lodhia, D.; Longo, M.; Lormand, M.; Lu, P.; Lubiński, M.; Lucianetti, A.; Lück, H.; Machenschalk, B.; Macinnis, M.; Mageswaran, M.; Mailand, K.; Mandel, I.; Mandic, V.; Márka, S.; Márka, Z.; Markosyan, A.; Markowitz, J.; Maros, E.; Martin, I. W.; Martin, R. M.; Marx, J. N.; Mason, K.; Matichard, F.; Matone, L.; Matzner, R. A.; Mavalvala, N.; McCarthy, R.; McClelland, D. E.; McGuire, S. C.; McHugh, M.; McIntyre, G.; McKechan, D. J. A.; McKenzie, K.; Mehmet, M.; Melatos, A.; Melissinos, A. C.; Menéndez, D. F.; Mendell, G.; Mercer, R. A.; Meshkov, S.; Messenger, C.; Meyer, M. S.; Miller, J.; Minelli, J.; Mino, Y.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Miyakawa, O.; Moe, B.; Mohanty, S. D.; Mohapatra, S. R. P.; Moreno, G.; Morioka, T.; Mors, K.; Mossavi, K.; Mowlowry, C.; Mueller, G.; Müller-Ebhardt, H.; Muhammad, D.; Mukherjee, S.; Mukhopadhyay, H.; Mullavey, A.; Munch, J.; Murray, P. G.; Myers, E.; Myers, J.; Nash, T.; Nelson, J.; Newton, G.; Nishizawa, A.; Numata, K.; O'Dell, J.; O'Reilly, B.; O'Shaughnessy, R.; Ochsner, E.; Ogin, G. H.; Ottaway, D. J.; Ottens, R. S.; Overmier, H.; Owen, B. J.; Pan, Y.; Pankow, C.; Papa, M. A.; Parameshwaraiah, V.; Patel, P.; Pedraza, M.; Penn, S.; Perreca, A.; Pierro, V.; Pinto, I. M.; Pitkin, M.; Pletsch, H. J.; Plissi, M. V.; Postiglione, F.; Principe, M.; Prix, R.; Prokhorov, L.; Punken, O.; Quetschke, V.; Raab, F. J.; Rabeling, D. S.; Radkins, H.; Raffai, P.; Raics, Z.; Rainer, N.; Rakhmanov, M.; Raymond, V.; Reed, C. M.; Reed, T.; Rehbein, H.; Reid, S.; Reitze, D. H.; Riesen, R.; Riles, K.; Rivera, B.; Roberts, P.; Robertson, N. A.; Robinson, C.; Robinson, E. L.; Roddy, S.; Röver, C.; Rollins, J.; Romano, J. D.; Romie, J. H.; Rowan, S.; Rüdiger, A.; Russell, P.; Ryan, K.; Sakata, S.; Sancho de La Jordana, L.; Sandberg, V.; Sannibale, V.; Santamaría, L.; Saraf, S.; Sarin, P.; Sathyaprakash, B. S.; Sato, S.; Satterthwaite, M.; Saulson, P. R.; Savage, R.; Savov, P.; Scanlan, M.; Schilling, R.; Schnabel, R.; Schofield, R.; Schulz, B.; Schutz, B. F.; Schwinberg, P.; Scott, J.; Scott, S. M.; Searle, A. C.; Sears, B.; Seifert, F.; Sellers, D.; Sengupta, A. S.; Sergeev, A.; Shapiro, B.; Shawhan, P.; Shoemaker, D. H.; Sibley, A.; Siemens, X.; Sigg, D.; Sinha, S.; Sintes, A. M.; Slagmolen, B. J. J.; Slutsky, J.; Smith, J. R.; Smith, M. R.; Smith, N. D.; Somiya, K.; Sorazu, B.; Stein, A.; Stein, L. C.; Steplewski, S.; Stochino, A.; Stone, R.; Strain, K. A.; Strigin, S.; Stroeer, A.; Stuver, A. L.; Summerscales, T. Z.; Sun, K.-X.; Sung, M.; Sutton, P. J.; Szokoly, G. P.; Talukder, D.; Tang, L.; Tanner, D. B.; Tarabrin, S. P.; Taylor, J. R.; Taylor, R.; Thacker, J.; Thorne, K. A.; Thorne, K. S.; Thüring, A.; Tokmakov, K. V.; Torres, C.; Torrie, C.; Traylor, G.; Trias, M.; Ugolini, D.; Ulmen, J.; Urbanek, K.; Vahlbruch, H.; Vallisneri, M.; van den Broeck, C.; van der Sluys, M. V.; van Veggel, A. A.; Vass, S.; Vaulin, R.; Vecchio, A.; Veitch, J.; Veitch, P.; Veltkamp, C.; Villar, A.; Vorvick, C.; Vyachanin, S. P.; Waldman, S. J.; Wallace, L.; Ward, R. L.; Weidner, A.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Wen, L.; Wen, S.; Wette, K.; Whelan, J. T.; Whitcomb, S. E.; Whiting, B. F.; Wilkinson, C.; Willems, P. A.; Williams, H. R.; Williams, L.; Willke, B.; Wilmut, I.; Winkelmann, L.; Winkler, W.; Wipf, C. C.; Wiseman, A. G.; Woan, G.; Wooley, R.; Worden, J.; Wu, W.; Yakushin, I.; Yamamoto, H.; Yan, Z.; Yoshida, S.; Zanolin, M.; Zhang, J.; Zhang, L.; Zhao, C.; Zotov, N.; Zucker, M. E.; Zur Mühlen, H.; Zweizig, J.; Robinet, F.

2009-09-01

We report on a matched-filter search for gravitational wave bursts from cosmic string cusps using LIGO data from the fourth science run (S4) which took place in February and March 2005. No gravitational waves were detected in 14.9 days of data from times when all three LIGO detectors were operating. We interpret the result in terms of a frequentist upper limit on the rate of gravitational wave bursts and use the limits on the rate to constrain the parameter space (string tension, reconnection probability, and loop sizes) of cosmic string models. Many grand unified theory-scale models (with string tension Gμ/c2≈10-6) can be ruled out at 90% confidence for reconnection probabilities p≤10-3 if loop sizes are set by gravitational back reaction.

Tensionless string spectra on AdS3

NASA Astrophysics Data System (ADS)

Gaberdiel, Matthias R.; Gopakumar, Rajesh

2018-05-01

The spectrum of superstrings on AdS3 × S3 × M 4 with pure NS-NS flux is analysed for the background where the radius of the AdS space takes the minimal value ( k = 1). Both for M 4 = S3 × S1 and M 4 = T 4 we show that there is a special set of physical states, coming from the bottom of the spectrally flowed continuous representations, which agree in precise detail with the single particle spectrum of a free symmetric product orbifold. For the case of AdS3 × S3 × T 4 this relies on making sense of the world-sheet theory at k = 1, for which we make a concrete proposal. We also comment on the implications of this striking result.

Holographic description of a quantum black hole on a computer

NASA Astrophysics Data System (ADS)

Hanada, Masanori; Hyakutake, Yoshifumi; Ishiki, Goro; Nishimura, Jun

2014-05-01

Black holes have been predicted to radiate particles and eventually evaporate, which has led to the information loss paradox and implies that the fundamental laws of quantum mechanics may be violated. Superstring theory, a consistent theory of quantum gravity, provides a possible solution to the paradox if evaporating black holes can actually be described in terms of standard quantum mechanical systems, as conjectured from the theory. Here, we test this conjecture by calculating the mass of a black hole in the corresponding quantum mechanical system numerically. Our results agree well with the prediction from gravity theory, including the leading quantum gravity correction. Our ability to simulate black holes offers the potential to further explore the yet mysterious nature of quantum gravity through well-established quantum mechanics.

Pulsed laser-induced formation of silica nanogrids

PubMed Central

2014-01-01

Silica grids with micron to sub-micron mesh sizes and wire diameters of 50 nm are fabricated on fused silica substrates. They are formed by single-pulse structured excimer laser irradiation of a UV-absorbing silicon suboxide (SiO x ) coating through the transparent substrate. A polydimethylsiloxane (PDMS) superstrate (cover layer) coated on top of the SiO x film prior to laser exposure serves as confinement for controlled laser-induced structure formation. At sufficiently high laser fluence, this process leads to grids consisting of a periodic loop network connected to the substrate at regular positions. By an additional high-temperature annealing, the residual SiO x is oxidized, and a pure SiO2 grid is obtained. PACS 81.07.-b; 81.07.Gf; 81.65.Cf PMID:24581305

Recent Progress in Nanoelectrical Characterizations of CdTe and Cu(In,Ga)Se2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Chun-Sheng; To, Bobby; Glynn, Stephen

2016-11-21

We report two recent nanoelectrical characterizations of CdTe and Cu(In, Ga)Se2 (CIGS) thin-film solar cells by developing atomic force microscopy-based nanoelectrical probes. Charges trapped at defects at the CdS/CdTe interface were probed by Kelvin probe force microscopy (KPFM) potential mapping and by ion-milling the CdTe superstrate device in a bevel glancing angle of ~0.5 degrees. The results show randomly distributed donor-like defects at the interface. The effect of K post-deposition treatment on the near-surface region of the CIGS film was studied by KPFM potential and scanning spreading resistance microscopy (SSRM) resistivity mapping, which shows passivation of grain-boundary potential and improvementmore » of resistivity uniformity by the K treatment.« less

Mice selectively bred for open-field thigmotaxis: life span and stability of the selection trait.

PubMed

Leppänen, Pia K; Ewalds-Kvist, S Béatrice M; Selander, Ritva-Kajsa

2005-04-01

In 2 experiments, the authors examined 69 mice selectively bred for high or low levels of open-field (OF) thigmotactic behavior (high open-field thigmotaxis [HOFT] and low open-field thigmotaxis [LOFT], respectively). They found that the strains differed in defecation during the 60-min exposure to the OF. Furthermore, the strains differed with regard to their life spans: The more thigmotactic HOFT mice lived longer than the LOFT mice. The strains were not differentiated by food intake or excretion. The strain difference in thigmotaxis was not age dependent, and it persisted in the home-cage condition as well. Neither the location (center or wall) of the starting point nor the shape (circular or square) of the OF arena affected the difference in wall-seeking behavior between the two strains. The authors concluded that the difference in thigmotaxis (or emotionality) between the HOFT and LOFT mice is a stable and robust feature of these animals.

Are voluntary wheel running and open-field behavior correlated in mice? Different answers from comparative and artificial selection approaches.

PubMed

Careau, Vincent; Bininda-Emonds, Olaf R P; Ordonez, Genesis; Garland, Theodore

2012-09-01

Voluntary wheel running and open-field behavior are probably the two most widely used measures of locomotion in laboratory rodents. We tested whether these two behaviors are correlated in mice using two approaches: the phylogenetic comparative method using inbred strains of mice and an ongoing artificial selection experiment on voluntary wheel running. After taking into account the measurement error and phylogenetic relationships among inbred strains, we obtained a significant positive correlation between distance run on wheels and distance moved in the open-field for both sexes. Thigmotaxis was negatively correlated with distance run on wheels in females but not in males. By contrast, mice from four replicate lines bred for high wheel running did not differ in either distance covered or thigmotaxis in the open field as compared with mice from four non-selected control lines. Overall, results obtained in the selection experiment were generally opposite to those observed among inbred strains. Possible reasons for this discrepancy are discussed.

Exposure to an open-field arena increases c-Fos expression in a distributed anxiety-related system projecting to the basolateral amygdaloid complex.

PubMed

Hale, M W; Hay-Schmidt, A; Mikkelsen, J D; Poulsen, B; Shekhar, A; Lowry, C A

2008-08-26

Anxiety states and anxiety-related behaviors appear to be regulated by a distributed and highly interconnected system of brain structures including the basolateral amygdala. Our previous studies demonstrate that exposure of rats to an open-field in high- and low-light conditions results in a marked increase in c-Fos expression in the anterior part of the basolateral amygdaloid nucleus (BLA) compared with controls. The neural mechanisms underlying the anatomically specific effects of open-field exposure on c-Fos expression in the BLA are not clear, however, it is likely that this reflects activation of specific afferent input to this region of the amygdala. In order to identify candidate brain regions mediating anxiety-induced activation of the basolateral amygdaloid complex in rats, we used cholera toxin B subunit (CTb) as a retrograde tracer to identify neurons with direct afferent projections to this region in combination with c-Fos immunostaining to identify cells responding to exposure to an open-field arena in low-light (8-13 lux) conditions (an anxiogenic stimulus in rats). Adult male Wistar rats received a unilateral microinjection of 4% CTb in phosphate-buffered saline into the basolateral amygdaloid complex. Rats were housed individually for 11 days after CTb injections and handled (HA) for 2 min each day. On the test day rats were either, 1) exposed to an open-field in low-light conditions (8-13 lux) for 15 min (OF); 2) briefly HA or 3) left undisturbed (control). We report that dual immunohistochemical staining for c-Fos and CTb revealed an increase in the percentage of c-Fos-immunopositive basolateral amygdaloid complex-projecting neurons in open-field-exposed rats compared with HA and control rats in the ipsilateral CA1 region of the ventral hippocampus, subiculum and lateral entorhinal cortex. These data are consistent with the hypothesis that exposure to the open-field arena activates an anxiety-related neuronal system with convergent input to the basolateral amygdaloid complex.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crijns, W; Vandenbroucke, D; Leblans, P

Purpose: Computed Radiography (CR) dosimetry could offer film dosimetry resolution and flexibility but with reusability and instantaneous processing. For an experimental CR-plate, designed for radiotherapy (Zeff=18), CR’s typical out-of-field over-response to low energy photons was previously reduced to 8%. The present work assesses the impact of the residual over-response when open-fields are combined or when intensity modulated fields are used. Methods: Agfa Healthcare’s experimental CRplate was scanned and erased 4min after each irradiation using a flying-spot CR-15-X-engine based reader, which was adapted for radiotherapy dosimetry. A CR-plate specific calibration and uniformity correction was used.For open-fields two abutting half beams (5×10cm{supmore » 2}) captured out-offield and in-field doses in a single image. Additionally, both half beams were measured individually as well as a 3×18Gy open-field SBRT-lung treatment. For intensity modulated fields standard test patterns (Chair and Pyramid) and a clinical 5×5Gy rectal VMAT plan were captured. All measurements were compared to the corresponding dose calculations. Results: For open-fields the out-of-field overdose was clearly larger than the in-field overdose (10% vs. 4%). The sum of the individual measurements corresponded well with the combined measurement (dose difference, ΔD<−2.2%). The SBRT case had no overdose in the high dose region; ΔD=−5.6%±3.3%, the deviation was attributed to CR-fading effects (−0.3%/min) which were not corrected for.Compared to open-fields, intensity modulated deliveries had a further increased over-response out-offield (ΔD=+58% to +125% [Chair] +43% [Pyramid]), due to the increased amount of low energy photons for IMRT. However, this effect was not measured in-field where even decreased dose signals were observed (ΔD=−0.3% to +2.25% [Chair], −4.5% to −0.1% [Pyramid]). The rectal VMAT treatment had a dose difference +2.4%±6.0%. The in-field deviations were attributed to a residual non-uniformity. Conclusion: The experimental CRplate’s out-of-field over-response does not propagate in in-field overresponse errors when static or dynamic (IMRT/VMAT) abutting fields are used.« less

Semiochemical lures reduce emigration and enhance pest control services in open-field predator augmentation

USDA-ARS?s Scientific Manuscript database

Augmentation biocontrol is a commercially viable pest management tactic in enclosed glasshouse environments, but is far less effective in open-field agriculture where newly released enemies rapidly disperse from release sites. We tested the potential for behavior-modifying semiochemicals to increase...

A Handheld Open-Field Infant Keratometer (An American Ophthalmological Society Thesis)

PubMed Central

Miller, Joseph M.

2010-01-01

Purpose: To design and evaluate a new infant keratometer that incorporates an unobstructed view of the infant with both eyes (open-field design). Methods: The design of the open-field infant keratometer is presented, and details of its construction are given. The design incorporates a single-ring keratoscope for measurement of corneal astigmatism over a 4-mm region of the cornea and includes a rectangular grid target concentric within the ring to allow for the study of higher-order aberrations of the eye. In order to calibrate the lens and imaging system, a novel telecentric test object was constructed and used. The system was bench calibrated against steel ball bearings of known dimensions and evaluated for accuracy while being used in handheld mode in a group of 16 adult cooperative subjects. It was then evaluated for testability in a group of 10 infants and toddlers. Results: Results indicate that while the device achieved the goal of creating an open-field instrument containing a single-ring keratoscope with a concentric grid array for the study of higher-order aberrations, additional work is required to establish better control of the vertex distance. Conclusion: The handheld open-field infant keratometer demonstrates testability suitable for the study of infant corneal astigmatism. Use of collimated light sources in future iterations of the design must be incorporated in order to achieve the accuracy required for clinical investigation. PMID:21212850

Potential risk levels of invasive Neoleucinodes elegantalis (small tomato borer) in areas optimal for open-field Solanum lycopersicum (tomato) cultivation in the present and under predicted climate change.

PubMed

da Silva, Ricardo Siqueira; Kumar, Lalit; Shabani, Farzin; Picanço, Marcelo Coutinho

2017-03-01

Neoleucinodes elegantalis is one of the major insect pests of Solanum lycopersicum. Currently, N. elegantalis is present only in America and the Caribbean, and is a threat in the world's largest S. lycopersicum-producing countries. In terms of potential impact on agriculture, the impact of climate change on insect invasions must be a concern. At present, no research exists regarding the effects of climatic change on the risk level of N. elegantalis. The purpose of this study was to develop a model for S. lycopersicum and N. elegantalis, utilizing CLIMEX to determine risk levels of N. elegantalis in open-field S. lycopersicum cultivation in the present and under projected climate change, using the global climate model CSIRO-Mk3.0. Large areas are projected to be suitable for N. elegantalis and optimal for open-field S. lycopersicum cultivation at the present time. However, in the future these areas will become unsuitable for both species. Conversely, other regions in the future may become optimal for open-field S. lycopersicum cultivation, with a varying risk level for N. elegantalis. The risk level results presented here provide a useful tool to design strategies to prevent the introduction and establishment of N. elegantalis in open-field S. lycopersicum cultivation. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

A handheld open-field infant keratometer (an american ophthalmological society thesis).

PubMed

Miller, Joseph M

2010-12-01

To design and evaluate a new infant keratometer that incorporates an unobstructed view of the infant with both eyes (open-field design). The design of the open-field infant keratometer is presented, and details of its construction are given. The design incorporates a single-ring keratoscope for measurement of corneal astigmatism over a 4-mm region of the cornea and includes a rectangular grid target concentric within the ring to allow for the study of higher-order aberrations of the eye. In order to calibrate the lens and imaging system, a novel telecentric test object was constructed and used. The system was bench calibrated against steel ball bearings of known dimensions and evaluated for accuracy while being used in handheld mode in a group of 16 adult cooperative subjects. It was then evaluated for testability in a group of 10 infants and toddlers. Results indicate that while the device achieved the goal of creating an open-field instrument containing a single-ring keratoscope with a concentric grid array for the study of higher-order aberrations, additional work is required to establish better control of the vertex distance. The handheld open-field infant keratometer demonstrates testability suitable for the study of infant corneal astigmatism. Use of collimated light sources in future iterations of the design must be incorporated in order to achieve the accuracy required for clinical investigation.

Effects of phenazepam on the behavior of C57BL/6 and BALB/c mice in the open field test after naloxone pretreatment.

PubMed

Seredenin, S B; Nadorova, A V; Kolik, L G; Yarkova, M A

2013-07-01

We studied the effects of phenazepam (0.075 mg/kg) after pretreatment (5 minutes before) with naloxone (10 mg/kg) on open-field behavior of C57Bl/6 and BALB/c mice. In ex vivo experiments, we studied the effects of naloxone (1 and 10 mg/kg) on receptor binding of [(3)H]-flunitrazepam by membranes of brain fraction (P1+P2) of C57Bl/6 and BALB/c mice. It was shown that naloxone increased motor activity in the open field in BALB/c mice and decreased this parameter in C57Bl/6 mice. During combined treatment, naloxone potentiated the activating effects of phenazepam on the open-field behavior of BALB/c mice and slightly increased the sedative effect of this drug in C57Bl/6 mice. Naloxone stimulated reception of [(3)H]-flunitrazepam in BALB/c mice and slightly increased radioligand binding in C57Bl/6 mice. These data attest to enhanced reception in benzodiazepine site of GABAA-receptor under conditions of opioid receptor blockade, the presence of anxiolytic or sedative (depending on the phenotype of the response to emotional stress) effect of naloxone, and co-directed effects of naloxone and benzodiazepine tranquilizer on open-field behavior of C57Bl/6 and BALB/c mice.

Comparison of the effects of adrafinil, propentofylline, and nicergoline on behavior in aged dogs.

PubMed

Siwak, C T; Gruet, P; Woehrlé, F; Muggenburg, B A; Murphey, H L; Milgram, N W

2000-11-01

To compare the efficacy of adrafinil, propentofylline, and nicergoline for enhancing behavior of aged dogs. 36 Beagles between 9 and 16 years old. Dogs were randomly assigned to receive adrafinil (20 mg/kg of body weight, PO, q 24 h; n = 12), propentofylline (5 mg/kg, PO, q 12 h; 12), or nicergoline (0.5 mg/kg, PO, q 24 h; 12) for 33 days. Baseline behaviors in an open field and in kennels (home cage) were recorded before treatment. After treatment, behaviors in the open field were recorded 2 hours after drug administration on days 2, 15, and 28, and 10 hours after administration on days 7, 20, and 33. Behaviors in the home cage were recorded 2 and 7 hours after drug administration on days 4, 17, and 30. Treatment with adrafinil resulted in a significant increase in locomotion in each of the open-field tests and an increase in locomotion in the home cage. This latter increase was smaller and more variable than that in the open field. Locomotion was not affected by treatment with propentofylline or nicergoline. In the open field, sniffing decreased over time in all 3 groups, but the largest decline was observed in the propentofylline group. Treatment with adrafinil may improve the quality of life of aged dogs by increasing exploratory behavior and alertness.

Opening mechanism of adenylate kinase can vary according to selected molecular dynamics force field

NASA Astrophysics Data System (ADS)

Unan, Hulya; Yildirim, Ahmet; Tekpinar, Mustafa

2015-07-01

Adenylate kinase is a widely used test case for many conformational transition studies. It performs a large conformational transition between closed and open conformations while performing its catalytic function. To understand conformational transition mechanism and impact of force field choice on E. Coli adenylate kinase, we performed all-atom explicit solvent classical molecular dynamics simulations starting from the closed conformation with four commonly used force fields, namely, Amber99, Charmm27, Gromos53a6, Opls-aa. We carried out 40 simulations, each one 200 ns. We analyzed completely 12 of them that show full conformational transition from the closed state to the open one. Our study shows that different force fields can have a bias toward different transition pathways. Transition time scales, frequency of conformational transitions, order of domain motions and free energy landscapes of each force field may also vary. In general, Amber99 and Charmm27 behave similarly while Gromos53a6 results have a resemblance to the Opls-aa force field results.

Education Scholars' Perceptions and Practices toward Open Access Publishing

ERIC Educational Resources Information Center

Ellingford, Lori Michelle

2012-01-01

Although open access publishing has been available since 1998, we know little regarding scholars' perceptions and practices toward publishing in open access outlets, especially in the social science community. Open access publishing has been slow to penetrate the field of education, yet the potential impact of open access could make this…

Method of determining interwell oil field fluid saturation distribution

DOEpatents

Donaldson, Erle C.; Sutterfield, F. Dexter

1981-01-01

A method of determining the oil and brine saturation distribution in an oil field by taking electrical current and potential measurements among a plurality of open-hole wells geometrically distributed throughout the oil field. Poisson's equation is utilized to develop fluid saturation distributions from the electrical current and potential measurement. Both signal generating equipment and chemical means are used to develop current flow among the several open-hole wells.

Apparatus for efficient sidewall containment of molten metal with horizontal alternating magnetic fields utilizing a ferromagnetic dam

DOEpatents

Praeg, W.F.

1997-02-11

An apparatus is disclosed for casting sheets of metal from molten metal. The apparatus includes a containment structure having an open side, a horizontal alternating magnetic field generating structure and a ferromagnetic dam. The magnetic field and the ferromagnetic dam contain the molten metal from leaking out side portions of the open side of the containment structure. 25 figs.

Measurements of store forces and moments and cavity pressures for a generic store in and near a box cavity at subsonic and transonic speeds

NASA Technical Reports Server (NTRS)

Stallings, Robert L., Jr.; Plentovich, E. B.; Tracy, M. B.; Hemsch, Michael J.

1995-01-01

An experimental force and moment study was conducted in the Langley 8-Foot Transonic Pressure Tunnel for a generic store in and near rectangular box cavities contained in a flat-plate configuration at subsonic and transonic speeds. Surface pressures were measured inside the cavities and on the flat plate. The length-to-height ratios were 5.42, 6.25, 10.83, and 12.50. The corresponding width-to-height ratios were 2.00, 2.00, 4.00, and 4.00. The free-stream Mach number range was from 0.20 to 0.95. Surface pressure measurements inside the cavities indicated that the flow fields for the shallow cavities were either closed or transitional near the transitional/closed boundary. For the deep cavities, the flow fields were either open or near the open/transitional boundary. The presence of the store did not change the type of flow field and had only small effects on the pressure distributions. For transitional or open transitional flow fields, increasing the free-stream Mach number resulted in large reductions in pitching-moment coefficient. Values of pitching-moment coefficient were always much greater for closed flow fields than for open flow fields.

On Gravitational Effects in the Schrödinger Equation

NASA Astrophysics Data System (ADS)

Pollock, M. D.

2014-04-01

The Schrödinger equation for a particle of rest mass and electrical charge interacting with a four-vector potential can be derived as the non-relativistic limit of the Klein-Gordon equation for the wave function , where and , or equivalently from the one-dimensional action for the corresponding point particle in the semi-classical approximation , both methods yielding the equation in Minkowski space-time , where and . We show that these two methods generally yield equations that differ in a curved background space-time , although they coincide when if is replaced by the effective mass in both the Klein-Gordon action and , allowing for non-minimal coupling to the gravitational field, where is the Ricci scalar and is a constant. In this case , where and , the correctness of the gravitational contribution to the potential having been verified to linear order in the thermal-neutron beam interferometry experiment due to Colella et al. Setting and regarding as the quasi-particle wave function, or order parameter, we obtain the generalization of the fundamental macroscopic Ginzburg-Landau equation of superconductivity to curved space-time. Conservation of probability and electrical current requires both electromagnetic gauge and space-time coordinate conditions to be imposed, which exemplifies the gravito-electromagnetic analogy, particularly in the stationary case, when div, where and . The quantum-cosmological Schrödinger (Wheeler-DeWitt) equation is also discussed in the -dimensional mini-superspace idealization, with particular regard to the vacuum potential and the characteristics of the ground state, assuming a gravitational Lagrangian which contains higher-derivative terms up to order . For the heterotic superstring theory , consists of an infinite series in , where is the Regge slope parameter, and in the perturbative approximation , is positive semi-definite for . The maximally symmetric ground state satisfying the field equations is Minkowski space for and anti-de Sitter space for.

An Autosampler and Field Sample Carrier for Maximizing Throughput Using an Open-Air, Surface Sampling Ion Source for MS

EPA Science Inventory

A recently developed, commercially available, open-air, surface sampling ion source for mass spectrometers provides individual analyses in several seconds. To realize its full throughput potential, an autosampler and field sample carrier were designed and built. The autosampler ...

Grafting Technique to Eliminate Rootstock Suckering of Grafted Tomatoes

USDA-ARS?s Scientific Manuscript database

Vegetable grafting has been proposed as a technique for avoiding disease problems in tomatoes in open field production. In this study we investigated the current use of grafting in an open field scenario and found a serious problem with the grafting techniques. In the Fall of 2007, commercially pr...

Development of Activity Level in Children

ERIC Educational Resources Information Center

Routh, Donald K.; And Others

1974-01-01

The open-field activity of 140 children 3-9 years old was observed. Children were either told to stay in one part of the room and play or were given free play instructions. Findings showed that open-field activity decreased with age; parents' activity ratings were also lower for older children. (CS)

Fuel cell assembly unit for promoting fluid service and electrical conductivity

DOEpatents

Jones, Daniel O.

1999-01-01

Fluid service and/or electrical conductivity for a fuel cell assembly is promoted. Open-faced flow channel(s) are formed in a flow field plate face, and extend in the flow field plate face between entry and exit fluid manifolds. A resilient gas diffusion layer is located between the flow field plate face and a membrane electrode assembly, fluidly serviced with the open-faced flow channel(s). The resilient gas diffusion layer is restrained against entering the open-faced flow channel(s) under a compressive force applied to the fuel cell assembly. In particular, a first side of a support member abuts the flow field plate face, and a second side of the support member abuts the resilient gas diffusion layer. The support member is formed with a plurality of openings extending between the first and second sides of the support member. In addition, a clamping pressure is maintained for an interface between the resilient gas diffusion layer and a portion of the membrane electrode assembly. Preferably, the support member is spikeless and/or substantially flat. Further, the support member is formed with an electrical path for conducting current between the resilient gas diffusion layer and position(s) on the flow field plate face.

MAJOR ELECTRON EVENTS AND CORONAL MAGNETIC CONFIGURATIONS OF THE RELATED SOLAR ACTIVE REGIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, C.; Owen, C. J.; Matthews, S. A.

A statistical survey of 26 major electron events during the period 2002 February through the end of solar cycle 23 is presented. We have obtained electron solar onset times and the peak flux spectra for each event by fitting to a power-law spectrum truncated by an exponential high-energy tail, i.e., f(E){approx}E{sup -{delta}}e{sup -E/E{sub 0}}. We also derived the coronal magnetic configurations of the related solar active regions (ARs) from the potential-field source-surface model. It is found that (1) 10 of the 11 well-connected open field-line events are prompt events whose solar onset times coincide with the maxima of flare emissionmore » and 13 of the 14 closed field-line events are delayed events. (2) A not-well-connected open field-line event and one of the closed field-line events are prompt events, they are both associated with large-scale coronal disturbances or dimming. (3) An averaged harder spectrum is found in open field-line events compared with the closed ones. Specifically, the averaged spectral index {delta} is of 1.6 {+-} 0.3 in open field-line events and of 2.0 {+-} 0.4 in closed ones. The spectra of three closed field-line events show infinite rollover energies E {sub 0}. These correlations clearly establish a significant link between the coronal magnetic field-line topology and the escape of charged particles from the flaring ARs into interplanetary space during the major solar energetic particle events.« less

Inflation from the Superstring Vacuum

NASA Astrophysics Data System (ADS)

Pollock, M. D.

Quartic higher-derivative gravitational terms in the effective Lagrangian of the heterotic superstring theory renormalize the bare, four-dimensional gravitational coupling κ 02≡ 8π G0, due to the reduction process hat { R}4-> Rbar { R}3, according to the formula κ -2 = κ 0-2 [1+15ζ (3)bar χ/16λ B r3 + bar χ/384π 2 Ar ], where Ar and Br are the moduli for the physical space gij(xk) and internal space bar {g}μ ν (yξ ), respectively. The Euler characteristic bar χ is negative for a three-generation Calabi-Yau manifold, and therefore both the additional terms, of tree-level and one-loop origin, produce a decrease in κ-2, which changes sign when κ-2 = 0. The corresponding tree-level critical point is B rc = [15 ζ (3)|bar χ|/16λ ]1/3 = 0.357, if we set bar χ = -6 and λ = 15π2, for compactification onto a torus. Values B r < B rc yield the anti-gravity region κ-2 < 0, which is analytically accessible from the normal gravity region κ-2 > 0. The only non-singular, vacuum minimum of the potential V(B r) ≡ (15)/(32)ζ (3)bar χλ -1κ 0-2R B r-3-A tilde r {B} { R}2 B r-2 is located at the point B r=[1 + 1.58(2/A r) (4/˜ B) × 10-4] B rc, where κ -2 = 4.73(2/Ar )(4/˜ B) × 10-4κ 0-2, the quadratic trace anomaly { R}2 anom dominates over { R}4, and a phase of de Sitter expansion may occur, as first envisaged by Starobinsky, in approximate agreement with the constraint due to the effect of gravitational waves upon the anisotropy of the cosmic microwave background radiation. There is no non-singular minimum of the potential V(A r) ≡ bar χκ 0-2RA_ r-1/768π 2 - ((1)/(4) { R}2E + ˜ {B} B r-2 { R}2 )Ar.

A Model for the Sources of the Slow Solar Wind

NASA Technical Reports Server (NTRS)

Antiochos, Spiro K.; Mikic, Z.; Titov, V. S.; Lionello, R.; Linker, J. A.

2010-01-01

Models for the origin of the slow solar wind must account for two seemingly contradictory observations: The slow wind has the composition of the closed-field corona, implying that it originates from the continuous opening and closing of flux at the boundary between open and closed field. On the other hand, the slow wind has large angular width, up to approximately 60 degrees, suggesting that its source extends far from the open-closed boundary. We propose a model that can explain both observations. The key idea is that the source of the slow wind at the Sun is a network of narrow (possibly singular) open-field corridors that map to a web of separatrices and quasi-separatrix layers in the heliosphere. We compute analytically the topology of an open-field corridor and show that it produces a quasi-separatrix layer in the heliosphere that extends to angles far front the heliospheric current sheet. We then use an MHD code and MIDI/SOHO observations of the photospheric magnetic field to calculate numerically, with high spatial resolution, the quasi-steady solar wind and magnetic field for a time period preceding the August 1, 2008 total solar eclipse. Our numerical results imply that, at least for this time period, a web of separatrices (which we term an S-web) forms with sufficient density and extent in the heliosphere to account for the observed properties of the slow wind. We discuss the implications of our S-web model for the structure and dynamics of the corona and heliosphere, and propose further tests of the model.

A Model for the Sources of the Slow Solar Wind

NASA Astrophysics Data System (ADS)

Antiochos, S. K.; Mikić, Z.; Titov, V. S.; Lionello, R.; Linker, J. A.

2011-04-01

Models for the origin of the slow solar wind must account for two seemingly contradictory observations: the slow wind has the composition of the closed-field corona, implying that it originates from the continuous opening and closing of flux at the boundary between open and closed field. On the other hand, the slow wind also has large angular width, up to ~60°, suggesting that its source extends far from the open-closed boundary. We propose a model that can explain both observations. The key idea is that the source of the slow wind at the Sun is a network of narrow (possibly singular) open-field corridors that map to a web of separatrices and quasi-separatrix layers in the heliosphere. We compute analytically the topology of an open-field corridor and show that it produces a quasi-separatrix layer in the heliosphere that extends to angles far from the heliospheric current sheet. We then use an MHD code and MDI/SOHO observations of the photospheric magnetic field to calculate numerically, with high spatial resolution, the quasi-steady solar wind, and magnetic field for a time period preceding the 2008 August 1 total solar eclipse. Our numerical results imply that, at least for this time period, a web of separatrices (which we term an S-web) forms with sufficient density and extent in the heliosphere to account for the observed properties of the slow wind. We discuss the implications of our S-web model for the structure and dynamics of the corona and heliosphere and propose further tests of the model.

Mithras Studies of the Boundary Between Open and Closed Field Lines.

DTIC Science & Technology

1994-01-31

I ¸ . . A- : - Final Report • March 1995 MITHRAS STUDIES OF THE BOUNDARY BETWEEN OPEN AND CLOSED FIELD LINES John D. Kelly, Program Manager Richard A...Kelly, Program Manager Richard A. Doe, Research Physicist Geoscience and Engineering Center SRI Project 3245 Prepared for: Department of the Air...characteristic energy, energy flux, and an estimate for upward field-aligned current. On the basis of coordinated radar/optical experiments, Vallance Jones et al

Effect of temperature and gap opening rate on the resiliency of candidate solid rocket booster O-ring materials

NASA Technical Reports Server (NTRS)

Lach, Cynthia L.

1992-01-01

In the redesign of the Space Shuttle solid rocket motor following the Challenger accident, the field and nozzle-to-case joints were designed to minimize gap opening caused by internal motor pressurization during ignition. The O-ring seals and glands for these joints were designed both to accommodate structural deflections and to promote pressure assisted sealing. The resiliency behavior of several candidate O-ring materials was evaluated for the effects of temperature and gap opening rates. The performance of three of the elastomeric materials was tested under the specific redesign gap opening requirement. Dynamic flexure conditions unique to launch produce low frequency vibrations in the gap opening. The effect of these vibrations on the ability of the O-ring to maintain contact with the sealing surface was addressed. The resiliency of the O-ring materials was found to be extremely sensitive to variations in temperature and gap opening rate. The top three elastomeric materials tracked the simulated solid rocket booster (SRB) field joint deflection at 75 and 120 F. The external tank/SRB attach strut load vibrations had a negligible effect on the ability of the O-ring to track the simulated SRB field joint deflection.

FAST OPENING SWITCH

DOEpatents

Bender, M.; Bennett, F.K.; Kuckes, A.F.

1963-09-17

A fast-acting electric switch is described for rapidly opening a circuit carrying large amounts of electrical power. A thin, conducting foil bridges a gap in this circuit and means are provided for producing a magnetic field and eddy currents in the foil, whereby the foil is rapidly broken to open the circuit across the gap. Advantageously the foil has a hole forming two narrow portions in the foil and the means producing the magnetic field and eddy currents comprises an annular coil having its annulus coaxial with the hole in the foil and turns adjacent the narrow portions of the foil. An electrical current flows through the coil to produce the magnetic field and eddy currents in the foil. (AEC)

Steady hydromagnetic flows in open magnetic fields. II - Global flows with static zones

NASA Technical Reports Server (NTRS)

Tsinganos, K.; Low, B. C.

1989-01-01

A theoretical study of an axisymmetric steady stellar wind with a static zone is presented, with emphasis on the situation where the global magnetic field is symmetrical about the stellar equator and is partially open. In this scenario, the wind escapes in open magnetic fluxes originating from a region at the star pole and a region at an equatorial belt of closed magnetic field in static equilibrium. The two-dimensional balance of the pressure gradient and the inertial, gravitational, and Lorentz forces in different parts of the flow are studied, along with the static interplay between external sources of energy (heating and/or cooling) distributed in the flow and the pressure distribution.

Open Access Publishing in the Field of Medical Informatics.

PubMed

Kuballa, Stefanie

2017-05-01

The open access paradigm has become an important approach in today's information and communication society. Funders and governments in different countries stipulate open access publications of funded research results. Medical informatics as part of the science, technology and medicine disciplines benefits from many research funds, such as National Institutes of Health in the US, Wellcome Trust in UK, German Research Foundation in Germany and many more. In this study an overview of the current open access programs and conditions of major journals in the field of medical informatics is presented. It was investigated whether there are suitable options and how they are shaped. Therefore all journals in Thomson Reuters Web of Science that were listed in the subject category "Medical Informatics" in 2014 were examined. An Internet research was conducted by investigating the journals' websites. It was reviewed whether journals offer an open access option with a subsequent check of conditions as for example the type of open access, the fees and the licensing. As a result all journals in the field of medical informatics that had an impact factor in 2014 offer an open access option. A predominantly consistent pricing range was determined with an average fee of 2.248 € and a median fee of 2.207 €. The height of a journals' open access fee did not correlate with the height of its Impact Factor. Hence, medical informatics journals have recognized the trend of open access publishing, though the vast majority of them are working with the hybrid method. Hybrid open access may however lead to problems in questions of double dipping and the often stipulated gold open access.

The S-Web Model for the Sources of the Slow Solar Wind

NASA Technical Reports Server (NTRS)

Antiochos, Spiro K.; Karpen, Judith T.; DeVore, C. Richard

2012-01-01

Models for the origin of the slow solar wind must account for two seemingly contradictory observations: The slow wind has the composition of the closed-field corona, implying that it originates from the continuous opening and closing of flux at the boundary between open and closed field. On the other hand, the slow wind has large angular width, up to 60 degrees, suggesting that its source extends far from the open-closed boundary. We describe a model that can explain both observations. The key idea is that the source of the slow wind at the Sun is a network of narrow (possibly singular) open-field corridors that map to a web of separatrices (the S-Web) and quasi-separatrix layers in the heliosphere. We discuss the dynamics of the S-Web model and its implications for present observations and for the upcoming observations from Solar Orbiter and Solar Probe Plus.

Band gap opening of bilayer graphene by F4-TCNQ molecular doping and externally applied electric field.

PubMed

Tian, Xiaoqing; Xu, Jianbin; Wang, Xiaomu

2010-09-09

The band gap opening of bilayer graphene with one side surface adsorption of F4-TCNQ is reported. F4-TCNQ doped bilayer graphene shows p-type semiconductor characteristics. With a F4-TCNQ concentration of 1.3 x 10(-10) mol/cm(2), the charge transfer between each F4-TCNQ molecule and graphene is 0.45e, and the built-in electric field, E(bi), between the graphene layers could reach 0.070 V/A. The charge transfer and band gap opening of the F4-TCNQ-doped graphene can be further modulated by an externally applied electric field (E(ext)). At 0.077 V/A, the gap opening at the Dirac point (K), DeltaE(K) = 306 meV, and the band gap, E(g) = 253 meV, are around 71% and 49% larger than those of the pristine bilayer under the same E(ext).

Finding Resolution for the Responsible Transparency of Economic Models in Health and Medicine.

PubMed

Padula, William V; McQueen, Robert Brett; Pronovost, Peter J

2017-11-01

The Second Panel on Cost-Effectiveness in Health and Medicine recommendations for conduct, methodological practices, and reporting of cost-effectiveness analyses has a number of questions unanswered with respect to the implementation of transparent, open source code interface for economic models. The possibility of making economic model source code could be positive and progressive for the field; however, several unintended consequences of this system should be first considered before complete implementation of this model. First, there is the concern regarding intellectual property rights that modelers have to their analyses. Second, the open source code could make analyses more accessible to inexperienced modelers, leading to inaccurate or misinterpreted results. We propose several resolutions to these concerns. The field should establish a licensing system of open source code such that the model originators maintain control of the code use and grant permissions to other investigators who wish to use it. The field should also be more forthcoming towards the teaching of cost-effectiveness analysis in medical and health services education so that providers and other professionals are familiar with economic modeling and able to conduct analyses with open source code. These types of unintended consequences need to be fully considered before the field's preparedness to move forward into an era of model transparency with open source code.

Field determination of multipollutant, open area combustion source emission factors with a hexacopter unmanned aerial vehicle

EPA Science Inventory

An emission sensor/sampler system was coupled to a NASA hexacopter unmanned aerial system (UAS) to characterize gases and particles in the plume emitted from open burning of military ordnance. The UAS/sampler was tested at two field sites resulting in 33 flights at Radford, VA a...

Role of herbicide treatments and application times in cogongrass eradication under open field infestation scenario

USDA-ARS?s Scientific Manuscript database

A Cogongrass eradication project was conducted from spring 2008 through fall 2011 on natural, open-field Cogongrass infestations at two locations near Tilman's Corner and Bayou La Batre in southwestern Alabama. Treatments consisted of glyphosate alone (4 lb/acre), imazapyr alone (0.75 lb/acre) and ...

Remote Laboratory and Animal Behaviour: An Interactive Open Field System

ERIC Educational Resources Information Center

Fiore, Lorenzo; Ratti, Giovannino

2007-01-01

Remote laboratories can provide distant learners with practical acquisitions which would otherwise remain precluded. Our proposal here is a remote laboratory on a behavioural test (open field test), with the aim of introducing learners to the observation and analysis of stereotyped behaviour in animals. A real-time video of a mouse in an…

[Motility of rats exposed to an altered photoperiod in the open field test].

PubMed

Sopova, I Iu; Zamorskiĭ, I I

2012-01-01

Motility of rats exposed to an altered photoperiod has been studied in the open field test. It has been shown that physical activity of rats kept in darkness declined. The correlation parameters of locomotor activity as compared to previous data changed in animals kept in continuous light.

Using canopy resistance for infrared heater control when warming open-field plots

USDA-ARS?s Scientific Manuscript database

Several research groups are using or planning to use arrays of infrared heaters to simulate global warming in open-field plots with a control strategy that involves maintaining a constant rise in canopy temperatures of the heated plots above those of un-heated Reference plots. . However, if the warm...

Dose-response effects of systemic anandamide administration in mice sequentially submitted to the open field and elevated plus-maze tests.

PubMed

Ribeiro, A; Ferraz-de-Paula, V; Pinheiro, M L; Palermo-Neto, J

2009-06-01

The endocannabinoid system is involved in the control of many physiological functions, including the control of emotional states. In rodents, previous exposure to an open field increases the anxiety-like behavior in the elevated plus-maze. Anxiolytic-like effects of pharmacological compounds that increase endocannabinoid levels have been well documented. However, these effects are more evident in animals with high anxiety levels. Several studies have described characteristic inverted U-shaped dose-response effects of drugs that modulate the endocannabinoid levels. However, there are no studies showing the effects of different doses of exogenous anandamide, an endocannabinoid, in animal models of anxiety. Thus, in the present study, we determined the dose-response effects of exogenous anandamide at doses of 0.01, 0.1, and 1.0 mg/kg in C57BL/6 mice (N = 10/group) sequentially submitted to the open field and elevated plus-maze. Anandamide was diluted in 0.9% saline, ethyl alcohol, Emulphor (18:1:1) and administered ip (0.1 mL/10 g body weight); control animals received the same volume of anandamide vehicle. Anandamide at the dose of 0.1 mg/kg (but not of 0.01 or 1 mg/kg) increased (P < 0.05) the time spent and the distance covered in the central zone of the open field, as well as the exploration of the open arms of the elevated plus-maze. Thus, exogenous anandamide, like pharmacological compounds that increase endocannabinoid levels, promoted a characteristic inverted U-shaped dose-response effect in animal models of anxiety. Furthermore, anandamide (0.1 mg/kg) induced an anxiolytic-like effect in the elevated plus-maze (P < 0.05) after exposing the animals to the open field test.

Modeling Drosophila Positional Preferences in Open Field Arenas with Directional Persistence and Wall Attraction

PubMed Central

Soibam, Benjamin; Goldfeder, Rachel L.; Manson-Bishop, Claire; Gamblin, Rachel; Pletcher, Scott D.; Shah, Shishir; Gunaratne, Gemunu H.; Roman, Gregg W.

2012-01-01

In open field arenas, Drosophila adults exhibit a preference for arena boundaries over internal walls and open regions. Herein, we investigate the nature of this preference using phenomenological modeling of locomotion to determine whether local arena features and constraints on movement alone are sufficient to drive positional preferences within open field arenas of different shapes and with different internal features. Our model has two components: directional persistence and local wall force. In regions far away from walls, the trajectory is entirely characterized by a directional persistence probability, , for each movement defined by the step size, , and the turn angle, . In close proximity to walls, motion is computed from and a local attractive force which depends on the distance between the fly and points on the walls. The directional persistence probability was obtained experimentally from trajectories of wild type Drosophila in a circular open field arena and the wall force was computed to minimize the difference between the radial distributions from the model and Drosophila in the same circular arena. The two-component model for fly movement was challenged by comparing the positional preferences from the two-component model to wild type Drosophila in a variety of open field arenas. In most arenas there was a strong concordance between the two-component model and Drosophila. In more complex arenas, the model exhibits similar trends, but some significant differences were found. These differences suggest that there are emergent features within these complex arenas that have significance for the fly, such as potential shelter. Hence, the two-component model is an important step in defining how Drosophila interact with their environment. PMID:23071591

Multi-port valve

DOEpatents

Lewin, Keith F.

1997-04-15

A multi-port valve for regulating, as a function of ambient air having varying wind velocity and wind direction in an open-field control area, the distribution of a fluid, particularly carbon dioxide (CO.sub.2) gas, in a fluid distribution system so that the control area remains generally at an elevated fluid concentration or level of said fluid. The multi-port valve generally includes a multi-port housing having a plurality of outlets therethrough disposed in a first pattern of outlets and at least one second pattern of outlets, and a movable plate having a plurality of apertures extending therethrough disposed in a first pattern of apertures and at least one second pattern of apertures. The first pattern of apertures being alignable with the first pattern of outlets and the at least one second pattern of apertures being alignable with the second pattern of outlets. The first pattern of apertures has a predetermined orientation with the at least one second pattern of apertures. For an open-field control area subject to ambient wind having a low velocity from any direction, the movable plate is positioned to equally distribute the supply of fluid in a fluid distribution system to the open-field control area. For an open-field control area subject to ambient wind having a high velocity from a given direction, the movable plate is positioned to generally distribute a supply of fluid in a fluid distribution system to that portion of the open-field control area located upwind.

Multi-port valve

DOEpatents

Lewin, K.F.

1997-04-15

A multi-port valve is described for regulating, as a function of ambient air having varying wind velocity and wind direction in an open-field control area, the distribution of a fluid, particularly carbon dioxide (CO{sub 2}) gas, in a fluid distribution system so that the control area remains generally at an elevated fluid concentration or level of said fluid. The multi-port valve generally includes a multi-port housing having a plurality of outlets there through disposed in a first pattern of outlets and at least one second pattern of outlets, and a movable plate having a plurality of apertures extending there through disposed in a first pattern of apertures and at least one second pattern of apertures. The first pattern of apertures being alignable with the first pattern of outlets and the at least one second pattern of apertures being alignable with the second pattern of outlets. The first pattern of apertures has a predetermined orientation with the at least one second pattern of apertures. For an open-field control area subject to ambient wind having a low velocity from any direction, the movable plate is positioned to equally distribute the supply of fluid in a fluid distribution system to the open-field control area. For an open-field control area subject to ambient wind having a high velocity from a given direction, the movable plate is positioned to generally distribute a supply of fluid in a fluid distribution system to that portion of the open-field control area located upwind. 7 figs.

Flow field and performance characteristics of combustor diffusers: A basic study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hestermann, R.; Kim, S.; Ben Khaled, A.

1995-10-01

Results of a detailed study concerning the influence of geometric as well as fluid mechanic parameters o the performance of a plane model combustor diffuser in cold flow are presented. For a qualitative insight into the complex flow field inside the prediffuser, the sudden expansion region, and the flow field around the flame tube dome, results of a flow visualization study with the hydrogen bubble method as well as with the ink jet method are presented for different opening angles of the prediffuser and for different flame tube distances. Also, quantitative data from detailed measurements with LDV and conventional pressuremore » probes in a geometrically similar air-driven setup are presented. These data clearly demonstrate the effect of boundary layer thickness as well as the influence of different turbulence levels at the entry of the prediffuser on the performance characteristics of combustor diffusers. The possibility of getting an unseparated flow field inside the prediffuser even at large opening angles by appropriately matching the diffuser`s opening angle and the flame tube distance is demonstrated. Also, for flows with an increased turbulence level at the entrance--all other conditions held constant--an increased opening angle can be realized without experiencing flow separation. The comparison of the experimental data with predictions utilizing a finite-volume-code based on a body-fitted coordinate system for diffusers with an included total opening angle less than 18 deg demonstrates the capability of describing the flow field in combustor diffusers with reasonable accuracy.« less

Exposure to a maternal cafeteria diet changes open-field behaviour in the developing offspring.

PubMed

Speight, Abigail; Davey, William G; McKenna, Emily; Voigt, Jörg-Peter W

2017-04-01

The early postnatal period is a sensitive period in rodents as behavioural systems are developing and maturing during this time. However, little is currently known about the behavioural effects of feeding a hyper-energetic cafeteria diet (CD) during the lactational period when offspring behaviour is tested during early adolescence. To this end, 23days old offspring from dams (Wistar) fed on CD during lactation were tested in either the open-field or the elevated plus-maze for exploration and anxiety-related behaviour. On postnatal day 9, maternal behaviour and non-maternal behaviour of the dam was assessed. It was hypothesized that lactational CD feeding would reduce anxiety in the offspring. CD-fed dams had a higher energy intake, due to an overconsumption of sugars and fats. When offspring from these dams were exposed to the open field after weaning, their locomotor activity was increased. They entered the more aversive inner zone of the open-field after a shorter latency, made more entries into and spent more time in the inner zone. Anxiety-related behaviour was not affected upon exposure to the elevated plus maze, suggesting anxiolysis in the open-field only. Increased maternal licking/grooming behaviour could possibly contribute to the anxiolytic phenotype as observed in the offspring from the CD group. In conclusion, we demonstrate that lactational overfeeding impacts on the development of behaviour in the early adolescent rat. Copyright © 2016 ISDN. Published by Elsevier Ltd. All rights reserved.

Demonstrating Empathy for Foreign-Born Employees through Openness and Acceptance: A Quasi-Experimental Field Study.

ERIC Educational Resources Information Center

Stull, James B.

1986-01-01

Reports on a study measuring foreign-born employees' perceptions of supervisors' acceptance of and openness to "open" messages from the employee. Suggests ways to improve supervisory demonstrations of empathy. (MS)

Hyperostosis in an orbital defect with craniofacial implants and open-field magnets: a clinical report.

PubMed

Sullivan, Maureen; Casey, David M; Alberico, Ronald; Litwin, Alan; Schaaf, Norman G

2007-04-01

An orbital facial prosthesis wearer was found to have significant hyperostosis in an exenterated orbit exposed to long-term, open field, rare earth magnets attached to craniofacial implants. Localized exophytic osseous formation was found in multiple areas around the exenterated orbit. The overall thickness of the walls of the exenterated orbit was approximately double that of the unaffected side. Magnetic field effect on bone formation and recommended treatment are discussed.

Confinement of plasma along shaped open magnetic fields from the centrifugal force of supersonic plasma rotation.

PubMed

Teodorescu, C; Young, W C; Swan, G W S; Ellis, R F; Hassam, A B; Romero-Talamas, C A

2010-08-20

Interferometric density measurements in plasmas rotating in shaped, open magnetic fields demonstrate strong confinement of plasma parallel to the magnetic field, with density drops of more than a factor of 10. Taken together with spectroscopic measurements of supersonic E × B rotation of sonic Mach 2, these measurements are in agreement with ideal MHD theory which predicts large parallel pressure drops balanced by centrifugal forces in supersonically rotating plasmas.

Wireless Sensing System Using Open-circuit, Electrically-conductive Spiral-trace Sensor

NASA Technical Reports Server (NTRS)

Woodard, Stanley E. (Inventor); Taylor, Bryant D. (Inventor)

2013-01-01

A wireless sensing system includes a sensor made from an electrical conductor shaped to form an open-circuit, electrically-conductive spiral trace having inductance and capacitance. In the presence of a time-varying magnetic field, the sensor resonates to generate a harmonic response having a frequency, amplitude and bandwidth. A magnetic field response recorder wirelessly transmits the time-varying magnetic field to the sensor and wirelessly detects the sensor's response frequency, amplitude and bandwidth.

Design and Simulation Test of an Open D-Dot Voltage Sensor

PubMed Central

Bai, Yunjie; Wang, Jingang; Wei, Gang; Yang, Yongming

2015-01-01

Nowadays, sensor development focuses on miniaturization and non-contact measurement. According to the D-dot principle, a D-dot voltage sensor with a new structure was designed based on the differential D-dot sensor with a symmetrical structure, called an asymmetric open D-dot voltage sensor. It is easier to install. The electric field distribution of the sensor was analyzed through Ansoft Maxwell and an open D-dot voltage sensor was designed. This open D-voltage sensor is characteristic of accessible insulating strength and small electric field distortion. The steady and transient performance test under 10 kV-voltage reported satisfying performances of the designed open D-dot voltage sensor. It conforms to requirements for a smart grid measuring sensor in intelligence, miniaturization and facilitation. PMID:26393590

Formation of Heliospheric Arcs of Slow Solar Wind

NASA Technical Reports Server (NTRS)

Higginson, A. K.; Antiochos, S. K.; Devore, C. R.; Wyper, P. F.; Zurbuchen, T. H.

2017-01-01

A major challenge in solar and heliospheric physics is understanding the origin and nature of the so-called slow solar wind. The Sun's atmosphere is divided into magnetically open regions, known as coronal holes, where the plasma streams out freely and fills the solar system, and closed regions, where the plasma is confined to coronal loops. The boundary between these regions extends outward as the heliospheric current sheet (HCS). Measurements of plasma composition strongly imply that much of the slow wind consists of plasma from the closed corona that escapes onto open field lines, presumably by field-line opening or by interchange reconnection. Both of these processes are expected to release closed-field plasma into the solar wind within and immediately adjacent to the HCS. Mysteriously, however, slow wind with closed-field plasma composition is often observed in situ far from the HCS. We use high-resolution, three-dimensional, magnetohydrodynamic simulations to calculate the dynamics of a coronal hole with a geometry that includes a narrow corridor flanked by closed field and is driven by supergranule-like flows at the coronal-hole boundary. These dynamics produce giant arcs of closed-field plasma that originate at the open-closed boundary in the corona, but extend far from the HCS and span tens of degrees in latitude and longitude at Earth. We conclude that such structures can account for the long-puzzling slow-wind observations.

Formation of Heliospheric Arcs of Slow Solar Wind

DOE Office of Scientific and Technical Information (OSTI.GOV)

Higginson, A. K.; Zurbuchen, T. H.; Antiochos, S. K.

A major challenge in solar and heliospheric physics is understanding the origin and nature of the so-called slow solar wind. The Sun’s atmosphere is divided into magnetically open regions, known as coronal holes, where the plasma streams out freely and fills the solar system, and closed regions, where the plasma is confined to coronal loops. The boundary between these regions extends outward as the heliospheric current sheet (HCS). Measurements of plasma composition strongly imply that much of the slow wind consists of plasma from the closed corona that escapes onto open field lines, presumably by field-line opening or by interchangemore » reconnection. Both of these processes are expected to release closed-field plasma into the solar wind within and immediately adjacent to the HCS. Mysteriously, however, slow wind with closed-field plasma composition is often observed in situ far from the HCS. We use high-resolution, three-dimensional, magnetohydrodynamic simulations to calculate the dynamics of a coronal hole with a geometry that includes a narrow corridor flanked by closed field and is driven by supergranule-like flows at the coronal-hole boundary. These dynamics produce giant arcs of closed-field plasma that originate at the open-closed boundary in the corona, but extend far from the HCS and span tens of degrees in latitude and longitude at Earth. We conclude that such structures can account for the long-puzzling slow-wind observations.« less

The structure and evolution of coronal holes

NASA Technical Reports Server (NTRS)

Timothy, A. F.; Krieger, A. S.; Vaiana, G. S.

1975-01-01

Soft X-ray observations of coronal holes are analyzed to determine the structure, temporal evolution, and rotational properties of those features as well as possible mechanisms which may account for their almost rigid rotational characteristics. It is shown that coronal holes are open features with a divergent magnetic-field configuration resulting from a particular large-scale magnetic-field topology. They are apparently formed when the successive emergence and dispersion of active-region fields produce a swath of unipolar field founded by fields of opposite polarity, and they die when large-scale field patterns emerge which significantly distort the original field configuration. Two types of holes are described (compact and elongated), and three possible rotation mechanisms are considered: a rigidly rotating subphotospheric phenomenon, a linking of high and low latitudes by closed field lines, and an interaction between moving coronal material and open field lines.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Chen; Paudel, Naba R.; Yan, Yanfa

Atom probe tomography (APT) data acquired from a CAMECA LEAP 4000 XHR for the CdS/CdTe interface for a non-CdCl 2 treated CdTe solar cell as well as the mass spectrum of an APT data set including a GB in a CdCl 2-treated CdTe solar cell are presented. Scanning electron microscopy (SEM) data showing the evolution of sample preparation for APT and scanning transmission electron microscopy (STEM) electron beam induced current (EBIC) are also presented. As a result, these data show mass spectrometry peak decomposition of Cu and Te within an APT dataset, the CdS/CdTe interface of an untreated CdTe solarmore » cell, preparation of APT needles from the CdS/CdTe interface in superstrate grown CdTe solar cells, and the preparation of a cross-sectional STEM EBIC sample.« less

Spherical D-brane by tachyon condensation

NASA Astrophysics Data System (ADS)

Asakawa, Tsuguhiko; Matsuura, So

2018-03-01

We find a novel tachyon condensation which provides a D-brane system with spherical worldvolume in the flat spacetime. The tachyon profile is a deformation of a known D0-brane solution on non-BPS D3-branes in type IIA superstring theory, which realizes a bound state of a spherical D2-brane and a D0-brane. The D0-brane is resolved into the sphere as a U(1) monopole flux of the unit magnetic charge. We show that the system has the correct tension and the RR-coupling. Although the low-energy effective action of the system is the same as that of the dual description of the fuzzy sphere solution of multiple D0-branes, our system cannot be equivalent to the fuzzy sphere. The use of projective modules in describing the tachyon condensation is emphasized.

Dark matter and cosmological nucleosynthesis

NASA Technical Reports Server (NTRS)

Schramm, D. N.

1986-01-01

Existing dark matter problems, i.e., dynamics, galaxy formation and inflation, are considered, along with a model which proposes dark baryons as the bulk of missing matter in a fractal universe. It is shown that no combination of dark, nonbaryonic matter can either provide a cosmological density parameter value near unity or, as in the case of high energy neutrinos, allow formation of condensed matter at epochs when quasars already existed. The possibility that correlations among galactic clusters are scale-free is discussed. Such a distribution of matter would yield a fractal of 1.2, close to a one-dimensional universe. Biasing, cosmic superstrings, and percolated explosions and hot dark matter are theoretical approaches that would satisfy the D = 1.2 fractal model of the large-scale structure of the universe and which would also allow sufficient dark matter in halos to close the universe.

Suspended Patch Antenna Array With Electromagnetically Coupled Inverted Microstrip Feed

NASA Technical Reports Server (NTRS)

Simons, Rainee N.

2000-01-01

The paper demonstrates a four-element suspended patch antenna array, with a parasitic patch layer and an electromagnetically coupled inverted microstrip feed, for linear polarization at K-Band frequencies. This antenna has the following advantages over conventional microstrip antennas: First, the inverted microstrip has lower attenuation than conventional microstrip; hence, conductor loss associated with the antenna corporate feed is lower resulting in higher gain and efficiency. Second, conventional proximity coupled patch antennas require a substrate for the feed and a superstrate for the patch. However, the inverted microstrip fed patch antenna makes use of a single substrate, and hence, is lightweight and low cost. Third, electromagnetic coupling results in wider bandwidth. Details regarding the design and fabrication will be presented as well as measured results including return loss, radiation patterns and cross-polarization levels.

Holographic description of a quantum black hole on a computer.

PubMed

Hanada, Masanori; Hyakutake, Yoshifumi; Ishiki, Goro; Nishimura, Jun

2014-05-23

Black holes have been predicted to radiate particles and eventually evaporate, which has led to the information loss paradox and implies that the fundamental laws of quantum mechanics may be violated. Superstring theory, a consistent theory of quantum gravity, provides a possible solution to the paradox if evaporating black holes can actually be described in terms of standard quantum mechanical systems, as conjectured from the theory. Here, we test this conjecture by calculating the mass of a black hole in the corresponding quantum mechanical system numerically. Our results agree well with the prediction from gravity theory, including the leading quantum gravity correction. Our ability to simulate black holes offers the potential to further explore the yet mysterious nature of quantum gravity through well-established quantum mechanics. Copyright © 2014, American Association for the Advancement of Science.

MAVEN observations of complex magnetic field topology in the Martian magnetotail

NASA Astrophysics Data System (ADS)

DiBraccio, Gina A.; Espley, Jared R.; Luhmann, Janet G.; Curry, Shannon M.; Gruesbeck, Jacob R.; Connerney, John E. P.; Soobiah, Yasir; Xu, Shaosui; Mitchell, David M.; Harada, Yuki; Halekas, Jasper S.; Brain, David A.; Dong, Chuanfei; Hara, Takuya; Jakosky, Bruce M.

2017-04-01

MAVEN observations have revealed an unexpectedly complex magnetic field configuration in the magnetotail of Mars. This planetary magnetotail forms as the solar wind interacts with the Martian upper atmosphere and the interplanetary magnetic field (IMF) drapes around the planet. This interaction is classically defined as an induced magnetosphere similar to the plasma environments of Venus and comets. However, unlike at these induced magnetic environments, Mars is complicated by the existence of crustal magnetic fields, which are able to reconnect with the IMF to produce open magnetic fields. Preliminary magnetohydrodynamic simulation results have suggested that this magnetic reconnection may be responsible for creating a hybrid magnetotail configuration between intrinsic and induced magnetospheres. This hybrid tail is composed of the closed planetary fields, draped IMF, and two distinct lobes of open magnetic fields. More importantly, these open lobes appear to be twisted by roughly 45°, either clockwise or counterclockwise, from the ecliptic plane with a strong dependence on the east-west component of the IMF and negligible influence from crustal field orientation. To explore this unexpected twisted-tail configuration, we analyze MAVEN Magnetometer (MAG) and Solar Wind Ion Analyzer (SWIA) data to examine magnetic field topology in the Martian magnetotail. We compare the average magnetic field orientation, directed toward and away from the planet, for a variety of solar wind parameters at various downtail distances. We conclude that the east-west IMF component strongly affects the magnetotail structure, as predicted by simulations. Furthermore, these data reveal that the tail lobes are indeed twisted, which we infer based on model results, to be regions of open magnetic fields that are likely reconnected crustal fields. These MAVEN observations confirm that the Martian magnetotail has a hybrid configuration between an intrinsic and induced magnetosphere, shifting the paradigm of Mars as we have understood it thus far.

Nonlinear evolution of the coronal magnetic field under reconnective relaxation

NASA Technical Reports Server (NTRS)

Wolfson, R.; Vekstein, G. E.; Priest, E. R.

1994-01-01

Recently, Vekstein et al. (Vekstein, Priest, & Steele 1993) have developed a model for coronal heating in which the corona responds to photospheric footpoint motions by small-scale reconnection events that bring about a relaxed state while conserving magnetic helicity but not field-line connectivity. Vekstein et al. consider a partially open field configuration in which magnetic helicity is ejected to infinity on open field lines but retained in the closed-field region. Under this scheme, they describe the evolution of an initially potential field, in response to helicity injection, in the linear regime. The present work uses numerical calculations to extend the model of Vekstein et al. into the fully nonlinear regime. The results show a rise and bulging of the field lines of the closed-field region with increasing magnetic helicity, to a point where further solutions are impossible. We interpret these solution-sequence endpoints as indicating a possible loss of equilibrium, in the sense that a relaxed equilibrium state may no longer be available to the corona when sufficient helicity has been injected. The rise and bulging behavior is reminiscent of what is observed in a helmet streamer just before the start of a coronal mass ejection (CME), and so our model suggests that a catastrophic loss of magnetic equilibrium might be the initiation mechanism for CMEs. We also find that some choices of boundary conditions can result in qualitative changes in the magnetic topology, with the appearance of magnetic islands. Whether or not this behavior occurs depends on the relative strengths of the fields in the closed- and open-field regions; in particular, island formation is most likely when the open field (which is potential) is strong and thus acts to confine the force-free closed field. Finally, we show that the energy released through reconnective relaxation can be a substantial fraction of the magnetic energy injected into the corona through footpoint motions and may be sufficient for heating the corona above active regions.

Brane-World Gravity.

PubMed

Maartens, Roy; Koyama, Kazuya

2010-01-01

The observable universe could be a 1+3-surface (the "brane") embedded in a 1+3+ d -dimensional spacetime (the "bulk"), with Standard Model particles and fields trapped on the brane while gravity is free to access the bulk. At least one of the d extra spatial dimensions could be very large relative to the Planck scale, which lowers the fundamental gravity scale, possibly even down to the electroweak (∼ TeV) level. This revolutionary picture arises in the framework of recent developments in M theory. The 1+10-dimensional M theory encompasses the known 1+9-dimensional superstring theories, and is widely considered to be a promising potential route to quantum gravity. At low energies, gravity is localized at the brane and general relativity is recovered, but at high energies gravity "leaks" into the bulk, behaving in a truly higher-dimensional way. This introduces significant changes to gravitational dynamics and perturbations, with interesting and potentially testable implications for high-energy astrophysics, black holes, and cosmology. Brane-world models offer a phenomenological way to test some of the novel predictions and corrections to general relativity that are implied by M theory. This review analyzes the geometry, dynamics and perturbations of simple brane-world models for cosmology and astrophysics, mainly focusing on warped 5-dimensional brane-worlds based on the Randall-Sundrum models. We also cover the simplest brane-world models in which 4-dimensional gravity on the brane is modified at low energies - the 5-dimensional Dvali-Gabadadze-Porrati models. Then we discuss co-dimension two branes in 6-dimensional models.

A Large-scale Plume in an X-class Solar Flare

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fleishman, Gregory D.; Nita, Gelu M.; Gary, Dale E.

Ever-increasing multi-frequency imaging of solar observations suggests that solar flares often involve more than one magnetic fluxtube. Some of the fluxtubes are closed, while others can contain open fields. The relative proportion of nonthermal electrons among those distinct loops is highly important for understanding energy release, particle acceleration, and transport. The access of nonthermal electrons to the open field is also important because the open field facilitates the solar energetic particle (SEP) escape from the flaring site, and thus controls the SEP fluxes in the solar system, both directly and as seed particles for further acceleration. The large-scale fluxtubes aremore » often filled with a tenuous plasma, which is difficult to detect in either EUV or X-ray wavelengths; however, they can dominate at low radio frequencies, where a modest component of nonthermal electrons can render the source optically thick and, thus, bright enough to be observed. Here we report the detection of a large-scale “plume” at the impulsive phase of an X-class solar flare, SOL2001-08-25T16:23, using multi-frequency radio data from Owens Valley Solar Array. To quantify the flare’s spatial structure, we employ 3D modeling utilizing force-free-field extrapolations from the line of sight SOHO /MDI magnetograms with our modeling tool GX-Simulator. We found that a significant fraction of the nonthermal electrons that accelerated at the flare site low in the corona escapes to the plume, which contains both closed and open fields. We propose that the proportion between the closed and open fields at the plume is what determines the SEP population escaping into interplanetary space.« less

A Model fot the Sources of the Slow Solar Wind

NASA Technical Reports Server (NTRS)

Antiochos, S. K.; Mikic, Z.; Titov, V. S.; Lionello, R.; Linker, J. A.

2011-01-01

Models for the origin of the slow solar wind must account for two seemingly contradictory observations: the slow wind has the composition of the closed-field corona, implying that it originates from the continuous opening and closing of flux at the boundary between open and closed field. On the other hand, the slow wind also has large angular width, up to approx.60deg, suggesting that its source extends far from the open-closed boundary. We propose a model that can explain both observations. The key idea is that the source of the slow wind at the Sun is a network of narrow (possibly singular) open-field corridors that map to a web of separatrices and quasi-separatrix layers in the heliosphere. We compute analytically the topology of an open-field corridor and show that it produces a quasi-separatrix layer in the heliosphere that extends to angles far from the heliospheric current sheet. We then use an MHD code and MDI/SOHO observations of the photospheric magnetic field to calculate numerically, with high spatial resolution, the quasi-steady solar wind, and magnetic field for a time period preceding the 2008 August 1 total solar eclipse. Our numerical results imply that, at least for this time period, a web of separatrices (which we term an S-web) forms with sufficient density and extent in the heliosphere to account for the observed properties of the slow wind. We discuss the implications of our S-web model for the structure and dynamics of the corona and heliosphere and propose further tests of the model. Key words: solar wind - Sun: corona - Sun: magnetic topology

Identifying open magnetic field regions of the Sun and their heliospheric counterparts

NASA Astrophysics Data System (ADS)

Krista, L. D.; Reinard, A.

2017-12-01

Open magnetic regions on the Sun are either long-lived (coronal holes) or transient (dimmings) in nature. Both phenomena are fundamental to our understanding of the solar behavior as a whole. Coronal holes are the sources of high-speed solar wind streams that cause recurrent geomagnetic storms. Furthermore, the variation of coronal hole properties (area, location, magnetic field strength) over the solar activity cycle is an important marker of the global evolution of the solar magnetic field. Dimming regions, on the other hand, are short-lived coronal holes that often emerge in the wake of solar eruptions. By analyzing their physical properties and their temporal evolution, we aim to understand their connection with their eruptive counterparts (flares and coronal mass ejections) and predict the possibility of a geomagnetic storm. The author developed the Coronal Hole Automated Recognition and Monitoring (CHARM) and the Coronal Dimming Tracker (CoDiT) algorithms. These tools not only identify but track the evolution of open magnetic field regions. CHARM also provides daily coronal hole maps, that are used for forecasts at the NOAA Space Weather Prediction Center. Our goal is to better understand the processes that give rise to eruptive and non-eruptive open field regions and investigate how these regions evolve over time and influence space weather.

Long Term Results of Visual Field Progression Analysis in Open Angle Glaucoma Patients Under Treatment.

PubMed

Kocatürk, Tolga; Bekmez, Sinan; Katrancı, Merve; Çakmak, Harun; Dayanır, Volkan

2015-01-01

To evaluate visual field progression with trend and event analysis in open angle glaucoma patients under treatment. Fifteen year follow-up results of 408 eyes of 217 glaucoma patients who were followed at Adnan Menderes University, Department of Ophthalmology between 1998 and 2013 were analyzed retrospectively. Visual field data were collected for Mean Deviation (MD), Visual Field Index (VFI), and event occurrence. There were 146 primary open-angle glaucoma (POAG), 123 pseudoexfoliative glaucoma (XFG) and 139 normal tension glaucoma (NTG) eyes. MD showed significant change in all diagnostic groups (p<0.001). The difference of VFI between first and last examinations were significantly different in POAG (p<0.001), and XFG (p<0.003) but not in NTG. VFI progression rates were -0.3, -0.43, and -0.2 % loss/year in treated POAG, XFG, and NTG, respectively. The number of empty triangles were statistically different between POAG-NTG (p=0.001), and XFG-NTG (p=0.002) groups. The number of half-filled (p=0.002), and full-filled (p=0.010) triangles were significantly different between XFG-NTG groups. Functional long-term follow-up of glaucoma patients can be monitored with visual field indices. We herein report our fifteen year follow-up results in open angle glaucoma.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lehe, Remi

Many simulation software produce data in the form of a set of field values or of a set of particle positions. (one such example is that of particle-in-cell codes, which produce data on the electromagnetic fields that they simulate.) However, each particular software uses its own particular format and layout, for the output data. This makes it difficult to compare the results of different simulation software, or to have a common visualization tool for these results. However, a standardized layout for fields and particles has recently been developed: the openPMD format ( HYPERLINK "http://www.openpmd.org/"www.openpmd.org) This format is open- source, andmore » specifies a standard way in which field data and particle data should be written. The openPMD format is already implemented in the particle-in-cell code Warp (developed at LBL) and in PIConGPU (developed at HZDR, Germany). In this context, the proposed software (openPMD-viewer) is a Python package, which allows to access and visualize any data which has been formatted according to the openPMD standard. This package contains two main components: - a Python API, which allows to read and extract the data from a openPMD file, so as to be able to work with it within the Python environment. (e.g. plot the data and reprocess it with particular Python functions) - a graphical interface, which works with the ipython notebook, and allows to quickly visualize the data and browse through a set of openPMD files. The proposed software will be typically used when analyzing the results of numerical simulations. It will be useful to quickly extract scientific meaning from a set of numerical data.« less

Application of latent semantic analysis for open-ended responses in a large, epidemiologic study

PubMed Central

2011-01-01

Background The Millennium Cohort Study is a longitudinal cohort study designed in the late 1990s to evaluate how military service may affect long-term health. The purpose of this investigation was to examine characteristics of Millennium Cohort Study participants who responded to the open-ended question, and to identify and investigate the most commonly reported areas of concern. Methods Participants who responded during the 2001-2003 and 2004-2006 questionnaire cycles were included in this study (n = 108,129). To perform these analyses, Latent Semantic Analysis (LSA) was applied to a broad open-ended question asking the participant if there were any additional health concerns. Multivariable logistic regression was performed to examine the adjusted odds of responding to the open-text field, and cluster analysis was executed to understand the major areas of concern for participants providing open-ended responses. Results Participants who provided information in the open-ended text field (n = 27,916), had significantly lower self-reported general health compared with those who did not provide information in the open-ended text field. The bulk of responses concerned a finite number of topics, most notably illness/injury, exposure, and exercise. Conclusion These findings suggest generalized topic areas, as well as identify subgroups who are more likely to provide additional information in their response that may add insight into future epidemiologic and military research. PMID:21974837

3D for the people: multi-camera motion capture in the field with consumer-grade cameras and open source software

PubMed Central

Evangelista, Dennis J.; Ray, Dylan D.; Hedrick, Tyson L.

2016-01-01

ABSTRACT Ecological, behavioral and biomechanical studies often need to quantify animal movement and behavior in three dimensions. In laboratory studies, a common tool to accomplish these measurements is the use of multiple, calibrated high-speed cameras. Until very recently, the complexity, weight and cost of such cameras have made their deployment in field situations risky; furthermore, such cameras are not affordable to many researchers. Here, we show how inexpensive, consumer-grade cameras can adequately accomplish these measurements both within the laboratory and in the field. Combined with our methods and open source software, the availability of inexpensive, portable and rugged cameras will open up new areas of biological study by providing precise 3D tracking and quantification of animal and human movement to researchers in a wide variety of field and laboratory contexts. PMID:27444791

43 CFR 1784.4-3 - Open meetings.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Open meetings. 1784.4-3 Section 1784.4-3... Open meetings. (a) All advisory committee and subcommittee meetings and associated field examinations shall be open to the public and news media. (b) Anyone may appear before or file a statement with a...

43 CFR 1784.4-3 - Open meetings.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Open meetings. 1784.4-3 Section 1784.4-3... Open meetings. (a) All advisory committee and subcommittee meetings and associated field examinations shall be open to the public and news media. (b) Anyone may appear before or file a statement with a...

43 CFR 1784.4-3 - Open meetings.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Open meetings. 1784.4-3 Section 1784.4-3... Open meetings. (a) All advisory committee and subcommittee meetings and associated field examinations shall be open to the public and news media. (b) Anyone may appear before or file a statement with a...

43 CFR 1784.4-3 - Open meetings.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Open meetings. 1784.4-3 Section 1784.4-3... Open meetings. (a) All advisory committee and subcommittee meetings and associated field examinations shall be open to the public and news media. (b) Anyone may appear before or file a statement with a...

RESPONSE OF TURNIPS TO CHRONIC DOSES OF OZONE IN OPEN-TOP FIELD CHAMBERS

EPA Science Inventory

Turnips Brassica rapa L., were exposed to chronic doses of ozone(O3) by adding different amounts of O3 for 7 h a day to non-filtered air in open-top field chambers. One cultivar(Tokyo Cross) was tested in 1979 and four cultivars (Tokyo Cross, Shogoin, Purple Top White Globe and J...

Predicting Canopy Temperatures without and with Infrared Heating of Open-Field Plots and Energy Requirements for such Infrared Heating

USDA-ARS?s Scientific Manuscript database

In order to determine the likely effect of global warming on agricultural productivity while avoiding experimental artifacts, there is a need to conduct warming research under conditions as representative as possible of future open fields, i.e., temperature free-air controlled enhancement (T-FACE) e...

Characteristics of growing media mixes and application for open-field production of strawberry (Fragaria ananassa)

USDA-ARS?s Scientific Manuscript database

Pathogen-free growing media are widely used for strawberry production in protected structures in Europe but not common in the United States. There is a need to investigate the feasibility of producing strawberry fruits in open fields with the pathogen-free media in the U.S. The objective of the stud...

76 FR 37061 - Lolo and Kootenai National Forests' Sanders County Resource Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-24

... business meetings. These meetings are open to the public. The committee will meet on June 18, 2011 in Thompson Falls, Montana for a field trip to project sites. This trip is open to the public. DATES: June 18...-3821. SUPPLEMENTARY INFORMATION: The June 18, 2011 meeting will include a field trip to project sites...

78 FR 70318 - Meeting of the California Desert District Advisory Council

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-25

... an open work planning meeting on Friday, December 6, 2013 from 9 a.m. to 4 p.m. No field trip is... include updates by council members, the BLM California Desert District manager, five field office managers.... SUPPLEMENTARY INFORMATION: All DAC meetings are open to the public. Public comment for items not on the agenda...

A Multisite Cluster Randomized Field Trial of Open Court Reading

ERIC Educational Resources Information Center

Borman, Geoffrey D.; Dowling, N. Maritza; Schneck, Carrie

2008-01-01

In this article, the authors report achievement outcomes of a multisite cluster randomized field trial of Open Court Reading 2005 (OCR), a K-6 literacy curriculum published by SRA/McGraw-Hill. The participants are 49 first-grade through fifth-grade classrooms from predominantly minority and poor contexts across the nation. Blocking by grade level…

Eddy current probe response to open and closed surface flaws

NASA Technical Reports Server (NTRS)

Auld, B. A.; Muennemann, F.; Winslow, D. K.

1981-01-01

A general analysis of eddy current response to certain types of open and closed surface flaws is presented for both standard low-frequency and ferromagnetic-resonance (FMR) probes. It is shown analytically that for two-dimensional and three-dimensional surface flaws interrogated by a uniform probe field, the crack opening sensitivity increases with the operating frequency of the probe, this behavior being due to the Faraday induction effect. Experiments with low-frequency probes operating at or below 1 MHz and with the FMR probe operating at approximately 1000 MHz confirm this increase of the crack mouth opening displacement for practical situations where the probe field is not uniform in the vicinity of the flaw.

ION PRODUCING MECHANISM

DOEpatents

MacKenzie, K.R.

1958-09-01

An ion source is described for use in a calutron and more particularly deals with an improved filament arrangement for a calutron. According to the invention, the ion source block has a gas ionizing passage open along two adjoining sides of the block. A filament is disposed in overlying relation to one of the passage openings and has a greater width than the passage width, so that both the filament and opening lengths are parallel and extend in a transverse relation to the magnetic field. The other passage opening is parallel to the length of the magnetic field. This arrangement is effective in assisting in the production of a stable, long-lived arc for the general improvement of calutron operation.

Land-Surface Subsidence and Open Bedrock Fractures in the Tully Valley, Onondaga County, New York

USGS Publications Warehouse

Hackett, William R.; Gleason, Gayle C.; Kappel, William M.

2009-01-01

Open bedrock fractures were mapped in and near two brine field areas in Tully Valley, New York. More than 400 open fractures and closed joints were mapped for dimension, orientation, and distribution along the east and west valley walls adjacent to two former brine fields. The bedrock fractures are as much as 2 feet wide and over 50 feet deep, while linear depressions in the soil, which are 3 to 10 feet wide and 3 to 6 feet deep, indicate the presence of open bedrock fractures below the soil. The fractures are probably the result of solution mining of halite deposits about 1,200 feet below the land surface.

Multicolor CCD Photometry of the Open Cluster IC361

DTIC Science & Technology

2010-01-01

journal Volume 19 Numbers 1/2 2010 Contents V. Straizys, A. Kazlauskas. Young stars in the Camelopardalis dust and molecular clouds. VI. YSOs...Vilnius + I system for 7250 stars down to 1= 19.6 mag has been obtained in the 20’ x 26’ field of the open cluster IC 361 in Camelopardalis . The catalog...1= 19.6 mag has been obtained in the 20’ x 26’ field of the open cluster IC 361 in Camelopardalis . The catalog of 1420 stars down to V ~ 18.5 mag

Yang-Mills gauge conditions from Witten's open string field theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng Haidong; Siegel, Warren

2007-02-15

We construct the Zinn-Justin-Batalin-Vilkovisky action for tachyons and gauge bosons from Witten's 3-string vertex of the bosonic open string without gauge fixing. Through canonical transformations, we find the off-shell, local, gauge-covariant action up to 3-point terms, satisfying the usual field theory gauge transformations. Perturbatively, it can be extended to higher-point terms. It also gives a new gauge condition in field theory which corresponds to the Feynman-Siegel gauge on the world-sheet.

Evaluation of using digital gravity field models for zoning map creation

NASA Astrophysics Data System (ADS)

Loginov, Dmitry

2018-05-01

At the present time the digital cartographic models of geophysical fields are taking a special significance into geo-physical mapping. One of the important directions to their application is the creation of zoning maps, which allow taking into account the morphology of geophysical field in the implementation automated choice of contour intervals. The purpose of this work is the comparative evaluation of various digital models in the creation of integrated gravity field zoning map. For comparison were chosen the digital model of gravity field of Russia, created by the analog map with scale of 1 : 2 500 000, and the open global model of gravity field of the Earth - WGM2012. As a result of experimental works the four integrated gravity field zoning maps were obtained with using raw and processed data on each gravity field model. The study demonstrates the possibility of open data use to create integrated zoning maps with the condition to eliminate noise component of model by processing in specialized software systems. In this case, for solving problem of contour intervals automated choice the open digital models aren't inferior to regional models of gravity field, created for individual countries. This fact allows asserting about universality and independence of integrated zoning maps creation regardless of detail of a digital cartographic model of geo-physical fields.

Gravitational Scattering Amplitudes and Closed String Field Theory in the Proper-Time Gauge

NASA Astrophysics Data System (ADS)

Lee, Taejin

2018-01-01

We construct a covariant closed string field theory by extending recent works on the covariant open string field theory in the proper-time gauge. Rewriting the string scattering amplitudes generated by the closed string field theory in terms of the Polyakov string path integrals, we identify the Fock space representations of the closed string vertices. We show that the Fock space representations of the closed string field theory may be completely factorized into those of the open string field theory. It implies that the well known Kawai-Lewellen-Tye (KLT) relations of the first quantized string theory may be promoted to the second quantized closed string theory. We explicitly calculate the scattering amplitudes of three gravitons by using the closed string field theory in the proper-time gauge.

Using CellML with OpenCMISS to Simulate Multi-Scale Physiology

PubMed Central

Nickerson, David P.; Ladd, David; Hussan, Jagir R.; Safaei, Soroush; Suresh, Vinod; Hunter, Peter J.; Bradley, Christopher P.

2014-01-01

OpenCMISS is an open-source modeling environment aimed, in particular, at the solution of bioengineering problems. OpenCMISS consists of two main parts: a computational library (OpenCMISS-Iron) and a field manipulation and visualization library (OpenCMISS-Zinc). OpenCMISS is designed for the solution of coupled multi-scale, multi-physics problems in a general-purpose parallel environment. CellML is an XML format designed to encode biophysically based systems of ordinary differential equations and both linear and non-linear algebraic equations. A primary design goal of CellML is to allow mathematical models to be encoded in a modular and reusable format to aid reproducibility and interoperability of modeling studies. In OpenCMISS, we make use of CellML models to enable users to configure various aspects of their multi-scale physiological models. This avoids the need for users to be familiar with the OpenCMISS internal code in order to perform customized computational experiments. Examples of this are: cellular electrophysiology models embedded in tissue electrical propagation models; material constitutive relationships for mechanical growth and deformation simulations; time-varying boundary conditions for various problem domains; and fluid constitutive relationships and lumped-parameter models. In this paper, we provide implementation details describing how CellML models are integrated into multi-scale physiological models in OpenCMISS. The external interface OpenCMISS presents to users is also described, including specific examples exemplifying the extensibility and usability these tools provide the physiological modeling and simulation community. We conclude with some thoughts on future extension of OpenCMISS to make use of other community developed information standards, such as FieldML, SED-ML, and BioSignalML. Plans for the integration of accelerator code (graphical processing unit and field programmable gate array) generated from CellML models is also discussed. PMID:25601911

A model of the open magnetosphere. [with field configuration based on Chapman-Ferraro theory

NASA Technical Reports Server (NTRS)

Kan, J. R.; Akasofu, S.-I.

1974-01-01

The Chapman-Ferraro image method is extended to construct an idealized model of the open magnetosphere that responds to a change of the interplanetary field direction as well as to a change of the field magnitude or of the solar wind momentum flux. The magnetopause of the present model is an infinite plane surface having a normal field component distribution that is consistent with the merging theory. An upper limit on the inward displacement of the magnetopause following a southward turning of the interplanetary field is obtained. The results are in fair agreement with a single event reported by Aubry et al. (1971). The model determines the field configuration and the total magnetic flux connecting the magnetosphere to interplanetary space.

Relations between open-field, elevated plus-maze, and emergence tests in C57BL/6J and BALB/c mice injected with GABA- and 5HT-anxiolytic agents.

PubMed

Lalonde, Robert; Strazielle, Catherine

2010-06-01

Two 5HT(1A) receptor agonists and chlordiazepoxide were examined in open-field, elevated plus maze, and emergence tests. At doses with no effect in the open-field, chlordiazepoxide increased open and open/total arm visits as well as open arm duration in the elevated plus maze, whereas 5HT(1A) receptor agonists showed an anxiolytic response on a single measure. The anxiolytic action of chlordiazepoxide was limited to the less active BALB/c strain. Unlike the 5HT(1A) receptor agonists, chlordiazepoxide was also anxiolytic in the emergence test, once again only in BALB/c and not C57BL/6J mice. Significant correlations were found between emergence latencies and specific indicators of anxiety in the elevated plus-maze in chlordiazepoxide-treated but not in mice treated with buspirone and 8-OH-DPAT. These results indicate that elevated plus-maze and emergence tests depend on benzodiazepine receptors. In contrast, 5HT(1A) receptor agonists were ineffective in the emergence test and no correlation was found between emergence latencies and specific indicators of anxiety in the elevated plus-maze. Though superficially similar, the emergence test seems to tap into a partially separate facet of anxiety.

Spatial heterogeneity in post-dispersal predation on Prunus and Uvularia seeds.

PubMed

Webb, Sara L; Willson, Mary F

1985-08-01

We investigated effects of seed density, distance from parent, and habitat (woods, open field) on post-dispersal predation risk (chiefly by rodents) for seeds of Prunus virginiana (Rosaceae). Additional study of the habitat effect (woods, open field, treefall gap) was made with seeds of Prunus avium (Rosaceae) and Uvularia grandiflora (Liliaceae). Density of Prunus seeds (range 2-40 seeds/group) did not affect predation risk for individual seeds. Distance from parent plants did influence predation risk, which was greatest directly beneath parents. This distance effect primarily comprised a sharp drop in risk within 2 m of parents, a distance too small to generate a "spacing rule" for conspecifics.We found that habitat strongly influenced predation intensity. Rates of removal of Prunus seeds were higher in woods than in open fields, except when overall predation intensity was very low and no pattern could be discerned. Prunus seed removal rates were higher in closed woods than in treefall gaps. Consequently, a Prunus seed will more likely escape predation if dispersed to an open site. In contrast, Uvularia seed removal rates were higher in open fields than in woods but did not differ between closed woods and tree-fall gaps.Predation intensity was spatially patchy between and within experimental arrays, but was consistent over time at some specific points in space, possibly reflecting home ranges of seed predators.

Management of whitefly-transmitted viruses in open-field production systems.

PubMed

Lapidot, Moshe; Legg, James P; Wintermantel, William M; Polston, Jane E

2014-01-01

Whiteflies are a key pest of crops in open-field production throughout the tropics and subtropics. This is due in large part to the long and diverse list of devastating plant viruses transmitted by these vectors. Open-field production provides many challenges to manage these viruses and in many cases adequate management has not been possible. Diseases caused by whitefly-transmitted viruses have become limiting factors in open-field production of a wide range of crops, i.e., bean golden mosaic disease in beans, tomato yellow leaf curl disease in tomato, cassava mosaic disease and cassava brown streak disease in cassava, and cotton leaf crumple disease in cotton. While host resistance has proven to be the most cost-effective management solution, few examples of host resistance have been developed to date. The main strategy to limit the incidence of virus-infected plants has been the application of insecticides to reduce vector populations aided to some extent by the use of selected cultural practices. However, due to concerns about the effect of insecticides on pollinators, consumer demand for reduced pesticide use, and the ability of the whitefly vectors to develop insecticide-resistance, there is a growing need to develop and deploy strategies that do not rely on insecticides. The reduction in pesticide use will greatly increase the need for genetic resistance to more viruses in more crop plants. Resistance combined with selected IPM strategies could become a viable means to increase yields in crops produced in open fields despite the presence of whitefly-transmitted viruses.

Finasteride inhibited brain dopaminergic system and open-field behaviors in adolescent male rats.

PubMed

Li, Li; Kang, Yun-Xiao; Ji, Xiao-Ming; Li, Ying-Kun; Li, Shuang-Cheng; Zhang, Xiang-Jian; Cui, Hui-Xian; Shi, Ge-Ming

2018-02-01

Finasteride inhibits the conversion of testosterone to dihydrotestosterone. Because androgen regulates dopaminergic system in the brain, it could be hypothesized that finasteride may inhibit dopaminergic system. The present study therefore investigates the effects of finasteride in adolescent and early developmental rats on dopaminergic system, including contents of dopamine and its metabolites (dihydroxy phenyl acetic acid and homovanillic acid) and tyrosine hydroxylase expressions both at gene and protein levels. Meanwhile, open-field behaviors of the rats are examined because of the regulatory effect of dopaminergic system on the behaviors. Open-field behaviors were evaluated by exploratory and motor behaviors. Dopamine and its metabolites were assayed by liquid chromatography-mass spectrometry. Tyrosine hydroxylase mRNA and protein expressions were determined by real-time qRT-PCR and western blot, respectively. It was found that in adolescent male rats, administration of finasteride at doses of 25 and 50 mg/kg for 14 days dose dependently inhibited open-field behaviors, reduced contents of dopamine and its metabolites in frontal cortex, hippocampus, caudate putamen, nucleus accumbens, and down-regulated tyrosine hydroxylase mRNA and protein expressions in substantia nigra and ventral tegmental area. However, there was no significant change of these parameters in early developmental rats after finasteride treatment. These results suggest that finasteride inhibits dopaminergic system and open-field behaviors in adolescent male rats by inhibiting the conversion of testosterone to dihydrotestosterone, and imply finasteride as a potential therapeutic option for neuropsychiatric disorders associated with hyperactivities of dopaminergic system and androgen. © 2017 John Wiley & Sons Ltd.

The effects of heavy particle irradiation on exploration and response to environmental change

NASA Astrophysics Data System (ADS)

Casadesus, G.; Shukitt-Hale, B.; Cantuti-Castelvetri, I.; Rabin, B.; Joseph, J.

Free radicals produced by exposure to heavy particles have been found to produce motor and behavioral toxicity effects in rats similar to those found during aging. The present research was designed to investigate the effects of exposure to 56Fe particles on the ability to detect novel arrangements in a given environment of male Sprague-Dawley rats. Using a test of spatial memory previously demonstrated to be sensitive to aging, open-field activity and reaction to spatial and non-spatial changes were measured in a group that received a dose of 1.5 Gy (n=10) of 56Fe heavy particle radiation or in non- radiated controls. Animals irradiated with 1.5 Gy of56Fe particles exhibited some age-like effects in animals tested, even though they were for the most part, subtle. Animals took longer to enter, visited less and spent significantly less time in the middle and the center portions of the open-field independently of total frequency and duration of activity of both groups. Likewise, irradiated subjects reacted significantly more to novel objects placed in the open-field than did controls. However, irradiated subjects did not vary from controls in their exploration patterns when objects in the open-field were spatially rearranged. Thus, irradiation with a dose of 1.5 Gy of 56Fe high-energy particle radiation elicited age-like effects in general open-field exploratory behavior, but did not elicit age- like effects during the spatial and non-spatial rearrangement tasks. Supported by N.A.S.A. Grant NAG9-1190.

Effects of acute and long-term typical or atypical neuroleptics on morphine-induced behavioural effects in mice.

PubMed

Hollais, André W; Patti, Camilla L; Zanin, Karina A; Fukushiro, Daniela F; Berro, Laís F; Carvalho, Rita C; Kameda, Sonia R; Frussa-Filho, Roberto

2014-03-01

1. It has been suggested that the high prevalence of drug abuse in schizophrenics is related to chronic treatment with typical neuroleptics and dopaminergic supersensitivity that develops as a consequence. Within this context, atypical neuroleptics do not seem to induce this phenomenon. In the present study, we investigated the effects of acute administration or withdrawal from long-term administration of haloperidol and/or ziprasidone on morphine-induced open-field behaviour in mice. 2. In the first experiment, mice were given a single injection of haloperidol (1 mg/kg, i.p.) or several doses of ziprasidone (2, 4 or 6 mg/kg, i.p.) and motor activity was quantified by the open-field test. The aim of the second experiment was to verify the effects of an acute injection of haloperidol (1 mg/kg) or ziprasidone (6 mg/kg) on 20 mg/kg morphine-induced behaviours in the open-field test. In the third experiment, mice were treated with 1 mg/kg haloperidol and/or 2, 4 or 6 mg/kg ziprasidone for 20 days. Seventy-two hours after the last injection, mice were injected with 20 mg/kg, i.p., morphine and then subjected to the open-field test. Acute haloperidol or ziprasidone decreased spontaneous general activity and abolished morphine-induced locomotor stimulation. 3. Withdrawal from haloperidol or ziprasidone did not modify morphine-elicited behaviours in the open-field test. The results suggest that withdrawal from neuroleptic treatments does not contribute to the acute effect of morphine in schizophrenic patients. © 2014 Wiley Publishing Asia Pty Ltd.

The effects of heavy particle irradiation on exploration and response to environmental change

NASA Astrophysics Data System (ADS)

Casadesus, G.; Shukitt-Hale, B.; Cantuti-Castelvetri, I.; Rabin, B. M.; Joseph, J. A.

2004-01-01

Free radicals produced by exposure to heavy particles have been found to produce motor and cognitive behavioral toxicity effects in rats similar to those found during aging. The present research was designed to investigate the effects of exposure to 56Fe particles on the ability of male Sprague-Dawley rats to detect novel arrangements in a given environment. Using a test of spatial memory previously demonstrated to be sensitive to aging, open field activity and reaction to spatial and non-spatial changes were measured in a group that received a dose of 1.5 Gy ( n=10) of 56Fe heavy particle radiation or in non-radiated controls ( n=10). Animals irradiated with 1.5 Gy of 56Fe particles exhibited some age-like effects in rats tested, even though they were, for the most part, subtle. Animals took longer to enter, visited less and spent significantly less time in the middle and the center portions of the open field, independently of total frequency and duration of activity of both groups. Likewise, irradiated subjects spend significantly more time exploring novel objects placed in the open field than did controls. However, irradiated subjects did not vary from controls in their exploration patterns when objects in the open field were spatially rearranged. Thus, irradiation with a dose of 1.5 Gy of 56Fe high-energy particle radiation elicited age-like effects in general open field exploratory behavior, but did not elicit age-like effects during the spatial and non-spatial rearrangement tasks.

The effects of heavy particle irradiation on exploration and response to environmental change

NASA Technical Reports Server (NTRS)

Casadesus, G.; Shukitt-Hale, B.; Cantuti-Castelvetri, I.; Rabin, B. M.; Joseph, J. A.

2004-01-01

Free radicals produced by exposure to heavy particles have been found to produce motor and cognitive behavioral toxicity effects in rats similar to those found during aging. The present research was designed to investigate the effects of exposure to 56Fe particles on the ability of male Sprague-Dawley rats to detect novel arrangements in a given environment. Using a test of spatial memory previously demonstrated to be sensitive to aging, open field activity and reaction to spatial and non-spatial changes were measured in a group that received a dose of 1.5 Gy (n=10) of 56Fe heavy particle radiation or in non-radiated controls (n=10). Animals irradiated with 1.5 Gy of 56Fe particles exhibited some age-like effects in rats tested, even though they were, for the most part, subtle. Animals took longer to enter, visited less and spent significantly less time in the middle and the center portions of the open field, independently of total frequency and duration of activity of both groups. Likewise, irradiated subjects spend significantly more time exploring novel objects placed in the open field than did controls. However, irradiated subjects did not vary from controls in their exploration patterns when objects in the open field were spatially rearranged. Thus, irradiation with a dose of 1.5 Gy of 56Fe high-energy particle radiation elicited age-like effects in general open field exploratory behavior, but did not elicit age-like effects during the spatial and non-spatial rearrangement tasks. Published by Elsevier Ltd on behalf of COSPAR.

REPORT OF RESEARCH ACCOMPLISHMENTS AND FUTURE GOALS HIGH ENERGY PHYSICS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wise, Mark B.; Kapustin, Anton N.; Schwarz, John Henry

Caltech High Energy Physics (HEP) has a broad program in both experimental and theoretical physics. We are known for our creativity and leadership. The future is uncertain and we strive to be involved in all the major areas of experimental and theoretical HEP physics so no matter where the important discoveries occur we are well positioned to play an important role. An outstanding group of postdoctoral scholars, graduate students, staff scientists, and technical and administrative personnel support our efforts in experimental and theoretical physics. The PI’s on this grant are involved in the following program of experimental and theoretical activities:more » I) EXPERIMENTAL PHYSICS Our CMS group, led by Harvey Newman and Maria Spiropulu, has played a key role in the discovery and interpretation of the Higgs boson and in searches for new physics. They have important hardware responsibilities in both ECAL and HCAL and are also involved in the upgrades needed for the High Luminosity LHC. Newman's group also develops and operates Grid-based computing, networking, and collaborative systems for CMS and the US HEP community. The charged lepton (Mu2e) and quark BaBar flavor physics group is led by David Hitlin and Frank Porter. On Mu2e they have been instrumental in the design of the calorimeter. Construction responsibilities include one third of the crystals and associated readout as well as the calibration system. They also will have responsibility for a major part of the online system software. Although data taking ceased in 2008 the Caltech BaBar group is active on several new forefront analyses. The neutrino group is led by Ryan Patterson. They are central to NOvA's core oscillation physics program, to calibration, and to detector readiness being responsible for the production and installation of 12,000 APD arrays. They have key roles in neutrino appearance and disappearance analysis in MINOS and MINOS+. Sunil Golwala leads the dark matter direct detection effort. Areas of activity include: CDMS II data analysis, contributions to SuperCDMS Soudan operations and analysis, R&D towards SuperCDMS SNOLAB, development of a novel screener for radiocontamination (the BetaCage), and development of new WIMP detector concepts. Ren-Yuan Zhu leads the HEP crystal laboratory for the advanced detector R&D effort. The crystal lab is involved in development of novel scintillating crystals and has proposed several crystal based detector concepts for future HEP experiments at the energy and intensity frontiers. Its current research effort is concentrated on development of fast crystal scintillators with good radiation hardness and low cost. II) THEORETICAL PHYSICS The main theme of Sergei Gukov's current research is the relation between the geometry of quantum group invariants and their categorification, on the one hand, and the physics of supersymmetric gauge theory and string theory, on the other. Anton Kapustin's research spans a variety of topics in non-perturbative Quantum Field Theory (QFT). His main areas of interest are supersymmetric gauge theories, non-perturbative dualities in QFT, disorder operators, Topological Quantum Field Theory, and non-relativistic QFT. He is also interested in the foundations and possible generalizations of Quantum Mechanics. Hirosi Ooguri's current research has two main components. One is to find exact results in Calabi-Yau compactification of string theory. Another is to explore applications of the AdS/CFT correspondence. He also plans to continue his project with Caltech postdoctoral fellows on BPS spectra of supersymmetric gauge theories in diverse dimensions. John Preskill works on quantum information science. This field may lead to important future technologies, and also lead to new understanding of issues in fundamental physics John Schwarz has been exploring a number of topics in superstring theory/M-theory, supersymmetric gauge theory, and their AdS/CFT relationships. Much of the motivation for these studies is the desire to gain a deeper understanding of superstring theory and M-theory. The research interests of Mark Wise span particle physics, cosmology and nuclear physics. His recent work has centered on extensions of the standard model where baryon number and lepton number are gauged and extensions of the standard model that have novel sources of baryon number violation and new sources of charged lepton flavor violation« less

A Matter of Discipline: Open Access, the Humanities, and Art History

ERIC Educational Resources Information Center

Tomlin, Patrick

2009-01-01

Recent events suggest that open access has gained new momentum in the humanities, but the slow and uneven development of open-access initiatives in humanist fields continues to hinder the consolidation of efforts across the university. Although various studies have traced the general origins of the humanities' reticence to embrace open access, few…

A Numerical Study of Cavitation Inception in Complex Flow Fields

DTIC Science & Technology

2007-12-01

field in a tip vortex flow of an open propeller to better describe the interaction between the blade wake and the tip vortex (i.e. the roll-up... WAKE INTERACTION ON CAVITATION INCEPTION IN AN OPEN PROPELLER ................15 2.5 NON-SPHERICAL BUBBLE EFFECTS ON CAVITATION INCEPTION [14,15...18 2.6 STUDY OF CAVITATION INCEPTION NOISE [16,17,18

The Family as a Living Open System: An Emerging Conceptual Framework.

ERIC Educational Resources Information Center

Fawcett, Jacqueline

The conceptual framework of the family presented in this paper views the family as a reality in itself. The four-dimensional energy field that is the family system is a living open system, a dynamic whole engaged in mutual and simultaneous interaction with a four-dimensional energy field that is the environment. The family system is patterned and…

Infant titi monkey behavior in the open field test and the effect of early adversity

PubMed Central

Larke, Rebecca H.; Toubiana, Alice; Lindsay, Katrina A.; Mendoza, Sally P.; Bales, Karen L.

2017-01-01

The open field test is commonly used to measure anxiety-related behavior and exploration in rodents. Here, we used it as a standardized novel environment in which to evaluate the behavioral response of infant titi monkeys (Callicebus cupreus), to determine the effect of presence of individual family members, and to assess how adverse early experience alters infant behavior. Infants were tested in the open field for 5 days at ages 4 and 6 months in four successive 5 min trials on each day. A transport cage, which was situated on one side of the open field, was either empty (non-social control) or contained the father, mother, or sibling. Infant locomotor, vocalization, and exploratory behavior were quantified. Results indicated that age, sex, social condition, and early experience all had significant effects on infant behavior. Specifically, infants were generally more exploratory at 6 months and male infants were more exploratory than females. Infants distinguished between social and non-social conditions but made few behavioral distinctions between the attachment figure and other individuals. Infants which had adverse early life experience demonstrated greater emotional and physical independence, suggesting that early adversity led to resiliency in the novel environment. PMID:28605039

[Effects of psychological stress on performances in open-field test of rats and tyrosine's modulation].

PubMed

Chen, Wei-Qiang; Cheng, Yi-Yong; Li, Shu-Tian; Hong, Yan; Wang, Dong-Lan; Hou, Yue

2009-02-01

To explore the effects of different doses of tyrosine modulation on behavioral performances in open field test of psychological stress rats. The animal model of psychological stress was developed by restraint stress for 21 days. Wistar rats were randomly assigned to five groups (n = 10) as follows: control group (CT), stress control group (SCT), low, medium and high-doses of tyrosine modulation stress groups (SLT, SMT and SIT). The changes of behavioral performances were examined by open-field test. Serum levels of cortisol, norepinephrine and dopamine were also detected. The levels of serum cortisol were all increased obviously in the four stress groups, and their bodyweight gainings were diminished. The behavioral performances of SCT rats in open-field test were changed significantly in contrast to that of CT rats. However, The behavioral performances of SMT and SHT rats were not different from that of CT rats. In addition, the serum levels of norepinephrine and dopamine were downregulated obviously in SCT and SLT groups, and no differences were observed in other groups. Psychological stress can impair body behavioral performances, and moderate tyrosine modulation may improve these abnormal changes. The related mechanisms may be involved with the changes of norepinephrine and dopamine.

Habituation of medaka (Oryzias latipes) demonstrated by open-field testing.

PubMed

Matsunaga, Wataru; Watanabe, Eiji

2010-10-01

Habituation to novel environments is frequently studied to analyze cognitive phenotypes in animals, and an open-field test is generally conducted to investigate the changes that occur in animals during habituation. The test has not been used in behavioral studies of medaka (Oryzias latipes), which is recently being used in behavioral research. Therefore, we examined the open-field behavior of medaka on the basis of temporal changes in 2 conventional indexes of locomotion and position. The findings of our study clearly showed that medaka changed its behavior through multiple temporal phases as it became more familiar with new surroundings; this finding is consistent with those of other ethological studies in animals. During repeated open-field testing on 2 consecutive days, we observed that horizontal locomotion on the second day was less than that on the first day, which suggested that habituation is retained in fish for days. This temporal habituation was critically affected by water factors or visual cues of the tank, thereby suggesting that fish have spatial memory of their surroundings. Thus, the data from this study will afford useful fundamental information for behavioral phenotyping of medaka and for elucidating cognitive phenotypes in animals. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Understanding spatio-temporal strategies of adult zebrafish exploration in the open field test.

PubMed

Stewart, Adam Michael; Gaikwad, Siddharth; Kyzar, Evan; Kalueff, Allan V

2012-04-27

Zebrafish (Danio rerio) are emerging as a useful model organism for neuroscience research. Mounting evidence suggests that various traditional rodent paradigms may be adapted for testing zebrafish behavior. The open field test is a popular rodent test of novelty exploration, recently applied to zebrafish research. To better understand fish novelty behavior, we exposed adult zebrafish to two different open field arenas for 30 min, assessing the amount and temporal patterning of their exploration. While (similar to rodents) zebrafish scale their locomotory activity depending on the size of the tank, the temporal patterning of their activity was independent of arena size. These observations strikingly parallel similar rodent behaviors, suggesting that spatio-temporal strategies of animal exploration may be evolutionarily conserved across vertebrate species. In addition, we found interesting oscillations in zebrafish exploration, with the per-minute distribution of their horizontal activity demonstrating sinusoidal-like patterns. While such patterning is not reported for rodents and other higher vertebrates, a nonlinear regression analysis confirmed the oscillation patterning of all assessed zebrafish behavioral endpoints in both open field arenas, revealing a potentially important aspect of novelty exploration in lower vertebrates. Copyright © 2012 Elsevier B.V. All rights reserved.

Green house gas emissions from open field burning of agricultural residues in India.

PubMed

Murali, S; Shrivastava, Rajnish; Saxena, Mohini

2010-10-01

In India, about 435.98 MMT of agro-residues are produced every year, out of which 313.62 MMT are surplus. These residues are either partially utilized or un-utilised due to various constraints. To pave the way for subsequent season for agriculture activity, the excess crop residues are burnt openly in the fields, unmindful of their ill effects on the environment. The present study has been undertaken to evaluate the severity of air pollution through emission of green house gases (GHGs) due to open field burning of agro-residues in India. Open field burning of surplus agro-residues in India results in the emission of GHG. Emissions of CH4 and N2O in 1997-98 and 2006-07 have been 3.73 and 4.06 MMT CO2 equivalent, which is an increase of 8.88% over a decade. About three-fourths of GHG emissions from agro-residues burning were CH4 and the remaining one-fourth were N2O. Burning of wheat and paddy straws alone contributes to about 42% of GHGs. These GHG emissions can be avoided once the agro-residues are employed for sustainable, cost-effective and environment- friendly options like power generation.

Dynamical gauge effects in an open quantum network

NASA Astrophysics Data System (ADS)

Zhao, Jianshi; Price, Craig; Liu, Qi; Gemelke, Nathan

2016-05-01

We describe new experimental techniques for simulation of high-energy field theories based on an analogy between open thermodynamic systems and effective dynamical gauge-fields following SU(2) × U(1) Yang-Mills models. By coupling near-resonant laser-modes to atoms moving in a disordered optical environment, we create an open system which exhibits a non-equilibrium phase transition between two steady-state behaviors, exhibiting scale-invariant behavior near the transition. By measuring transport of atoms through the disordered network, we observe two distinct scaling behaviors, corresponding to the classical and quantum limits for the dynamical gauge field. This behavior is loosely analogous to dynamical gauge effects in quantum chromodynamics, and can mapped onto generalized open problems in theoretical understanding of quantized non-Abelian gauge theories. Additional, the scaling behavior can be understood from the geometric structure of the gauge potential and linked to the measure of information in the local disordered potential, reflecting an underlying holographic principle. We acknowledge support from NSF Award No.1068570, and the Charles E. Kaufman Foundation.

Toward tunable band gap and tunable dirac point in bilayer graphene with molecular doping.

PubMed

Yu, Woo Jong; Liao, Lei; Chae, Sang Hoon; Lee, Young Hee; Duan, Xiangfeng

2011-11-09

The bilayer graphene has attracted considerable attention for potential applications in future electronics and optoelectronics because of the feasibility to tune its band gap with a vertical displacement field to break the inversion symmetry. Surface chemical doping in bilayer graphene can induce an additional offset voltage to fundamentally affect the vertical displacement field and the band gap opening in bilayer graphene. In this study, we investigate the effect of chemical molecular doping on band gap opening in bilayer graphene devices with single or dual gate modulation. Chemical doping with benzyl viologen molecules modulates the displacement field to allow the opening of a transport band gap and the increase of the on/off ratio in the bilayer graphene transistors. Additionally, Fermi energy level in the opened gap can be rationally controlled by the amount of molecular doping to obtain bilayer graphene transistors with tunable Dirac points, which can be readily configured into functional devices, such as complementary inverters.

Topological Origins of the Slow Solar Wind

NASA Technical Reports Server (NTRS)

Antiochos, Spiro

2008-01-01

Although the slow solar wind has been studied for decades with both in situ and remote sensing observations, its origin is still a matter of intense debate. In the standard quasi-steady model, the slow wind is postulated to originate near coronal hole boundaries that define topologically well-behaved separatrices between open and closed field regions. In the interchange model, on the other hand, the slow wind is postulated to originate on open flux that is dynamically diffusing throughout the seemingly closed-field corona. We argue in favor of the quasi-steady scenario and propose that the slow wind is due to two effects: First, the open-closed boundary is highly complex due to the complexity of the photospheric flux distribution. Second, this boundary is continuously driven by the transport of magnetic helicity from the closed field region into the open. The implications of this model for the structure and dynamics of the corona and slow wind are discussed, and observational tests of the mode

In Search for the Open Educator: Proposal of a Definition and a Framework to Increase Openness Adoption among University Educators

ERIC Educational Resources Information Center

Nascimbeni, Fabio; Burgos, Daniel

2016-01-01

The paper explores the change process that university teachers need to go through in order to become fluent with Open Education approaches. Based on a literature review and a set of interviews with a number of leading experts in the field of Open Educational Resources and Open Education, the paper puts forward an original definition of Open…

Effects of Coronal Magnetic Field Structures on the Transport of Solar Energetic Particles

NASA Astrophysics Data System (ADS)

Zhao, Lulu; Zhang, Ming

2018-06-01

This Letter presents a model calculation of solar energetic particle (SEP) transport to test the sensitivity of the distribution of escaped SEPs in interplanetary space and dependence upon the details of the magnetic field structure in the corona. It is applied to a circumsolar event on 2011 November 3, in which SEPs are observed promptly after the solar event eruption by three spacecraft (the twin Solar TErrestrial RElations Observatories (STEREO-A and STEREO-B) and ACE) separated by more than 100° in longitude from each other. The corona magnetic field reconstructed from photosphseric field measurements using the PFSS method changes substantially before and after the solar eruption, especially around the active region. The locations of open field regions, separatrix surfaces including the heliospheric current sheet, and footpoints of magnetic field lines connected to the spacecraft location have shifted substantially. We inject 100 keV energetic electrons on the open field lines at 1.5 R s within the size of observed coronal mass ejections (CMEs) and follow their propagation in the corona and the interplanetary space. We find that with a perpendicular diffusion due to field line random walk equal to 10% of the supergranular diffusion rate, the overall distribution of escaped SEPs does not change much even though the region of open field lines from SEPs has changed. The result suggests that detailed small-scale coronal magnetic field structures and the exact magnetic field connection are not crucially important for observing SEPs in the interplanetary space.

BOOK REVIEW: Modern Supersymmetry

NASA Astrophysics Data System (ADS)

Kulish, Petr P.

2006-12-01

We have spent more than twenty years applying supersymmetry (SUSY) to elementary particle physics and attempting to find an experimental manifestation of this symmetry. Terning's monograph demonstrates the strong influence of SUSY on theoretical elaborations in the field of elementary particles. It gives both an overview of modern supersymmetry in elementary particle physics and calculation techniques. The author, trying to be closer to applications of SUSY in the real world of elementary particles, is also anticipating the importance of supersymmetry for rigorous study of nonperturbative phenomena in quantum field theory. In particular, he presents the `exact' SUSY β function using instanton methods, phenomena of anomalies and dualities. Supersymmetry algebra is introduced by adding two anticommuting spinor generators to Poincaré algebra and by presenting massive and massless supermultiplets of its representations. The author prefers to use mostly the component description of field contents of the theories in question rather than the superfield formalism. Such a style makes the account closer to physical chartacteristics. Relations required by SUSY among β functions of the gauge, Yukawa and quartic interactions are checked by direct calculations as well as to all orders in perturbation theory, thus demonstrating that SUSY survives quantization. A discussion is included of the hierarchy problem of different scales of weak and strong interactions and its possible solution by the minimal supersymmetric standard model. Different SUSY breaking mechanisms are presented corresponding to a realistic phenomenology. The monograph can also be considered as a guide to `duality' relations connecting different SUSY gauge theories, supergravities and superstrings. This is demonstrated referring to the particular properties and characteristics of these theories (field contents, scaling dimensions of appropriate operators etc). In particular, the last chapter deals with the AdS/CFT correspondence. The author explains clearly most of the arguments in discussions and refers for further details to original papers (with corresponding arXiv numbers), selected lists of which appear at the end of each chapter (there are more than 300 references in the book). Considered as a whole the book covers primers on quantum fields, Feynman diagrams, renormalization procedure and renormalization groups, as well as the representation theory of classical linear Lie algebras. Some necessary information on irreducible representations of su(N), so(N) and sp(2N) is given in an appendix. There are in the text short historical and biographical notes concerning those scientists who made important contributions to the subject of the monograph: S Coleman, Yu Golfand, E Witten and others. Most of the seventeen chapters contain a few exercises to check the reader's understanding of the corresponding material. This monograph will be useful for graduate students and researchers in the field of elementary particles.

Increased occurrence of pesticide residues on crops grown in protected environments compared to crops grown in open field conditions.

PubMed

Allen, Gina; Halsall, Crispin J; Ukpebor, Justina; Paul, Nigel D; Ridall, Gareth; Wargent, Jason J

2015-01-01

Crops grown under plastic-clad structures or in greenhouses may be prone to an increased frequency of pesticide residue detections and higher concentrations of pesticides relative to equivalent crops grown in the open field. To test this we examined pesticide data for crops selected from the quarterly reports (2004-2009) of the UK's Pesticide Residue Committee. Five comparison crop pairs were identified whereby one crop of each pair was assumed to have been grown primarily under some form of physical protection ('protected') and the other grown primarily in open field conditions ('open'). For each pair, the number of detectable pesticide residues and the proportion of crop samples containing pesticides were statistically compared (n=100 s samples for each crop). The mean concentrations of selected photolabile pesticides were also compared. For the crop pairings of cabbage ('open') vs. lettuce ('protected') and 'berries' ('open') vs. strawberries ('protected') there was a significantly higher number of pesticides and proportion of samples with multiple residues for the protected crops. Statistically higher concentrations of pesticides, including cypermethrin, cyprodinil, fenhexamid, boscalid and iprodione were also found in the protected crops compared to the open crops. The evidence here demonstrates that, in general, the protected crops possess a higher number of detectable pesticides compared to analogous crops grown in the open. This may be due to different pesticide-use regimes, but also due to slower rates of pesticide removal in protected systems. The findings of this study raise implications for pesticide management in protected-crop systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Reverse learning in WAG/Rij rats with depression-like behavior].

PubMed

Malyshev, A V; Zakharov, A M; Sarkisova, K Iu; Dubynin, V A

2012-01-01

Learning and reverse learning in a complex maze, behavior in the open field test, novelty-suppressed feeding test, and forced swimming test were studies in WAG/Rij and Wistar rats. As compared with Wistar rats, WAG/Rij rats more slowly learned the spatial task, more slowly performed in the learning and reverse learning tasks, and made more errors in the complex maze (18% of WAG/Rij rats didn't reach learning criterion). Moreover, WAG/Rij rats exhibited reduced grooming reactions in the open field test, longer latency of approaching to food in the novel open field, reduced amount of food consumed in the home cage in the novelty-suppressed feeding test, and increased immobility time in the forced swimming test. The results suggest cognitive impaiment in WAG/Rij rats with depression-like behavior.

Polymersome magneto-valves for reversible capture and release of nanoparticles

PubMed Central

van Rhee, P.G.; Rikken, R.S.M.; Abdelmohsen, L.K.E.A.; Maan, J.C.; Nolte, R.J.M.; van Hest, J.C.M.; Christianen, P.C.M.; Wilson, D.A.

2014-01-01

Stomatocytes are polymersomes with an infolded bowl-shaped architecture. This internal cavity is connected to the outside environment via a small ‘mouth’ region. Stomatocytes are assembled from diamagnetic amphiphilic block-copolymers with a highly anisotropic magnetic susceptibility, which permits to magnetically align and deform the polymeric self-assemblies. Here we show the reversible opening and closing of the mouth region of stomatocytes in homogeneous magnetic fields. The control over the size of the opening yields magneto-responsive supramolecular valves that are able to reversibly capture and release cargo. Furthermore, the increase in the size of the opening is gradual and starts at fields below 10 T, which opens the possibility of using these structures for delivery and nanoreactor applications. PMID:25248402

Electromagnetic scattering from a class of open-ended waveguide discontinuities

NASA Technical Reports Server (NTRS)

Altintas, A.; Pathak, P. H.; Burnside, Walter D.

1986-01-01

A relatively simple high frequency analysis of electromagnetic scattering from a class of open-ended waveguide discontinuites was developed. The waveguides are composed of perfectly-conducting sections in which the electromagnetic field can be written as the sum of waveguide modes. Junctions are formed at the open end and also within interior regions where different sections are joined. The reflection and transmission properties of each junction are described in terms of a scattering matrix which is determined by combining the modal ray picture with high frequency techniques such as the Geometrical Theory of Diffraction (GTD), the Equivalent Current Method (ECM), and modifications of the Physical Theory of Diffraction (PTD). A new set of equivalent circuits are employed in this ECM analysis which leads to a simple treatment of many types of junction discontinuities. Also, a new procedure is presented to improve the efficiency of the aperture integration at the open end which is required in the PTD procedure for finding the fields radiated from (or coupled to) the open end. Once the scattering matrices are determined, they are then combined using a self-consistent multiple scattering method to obtain the total scattered fields.

Effects of weld residual stresses on crack-opening area analysis of pipes for LBB applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dong, P.; Rahman, S.; Wilkowski, G.

1997-04-01

This paper summarizes four different studies undertaken to evaluate the effects of weld residual stresses on the crack-opening behavior of a circumferential through-wall crack in the center of a girth weld. The effect of weld residual stress on the crack-opening-area and leak-rate analyses of a pipe is not well understood. There are no simple analyses to account for these effects, and, therefore, they are frequently neglected. The four studies involved the following efforts: (1) Full-field thermoplastic finite element residual stress analyses of a crack in the center of a girth weld, (2) A comparison of the crack-opening displacements from amore » full-field thermoplastic residual stress analysis with a crack-face pressure elastic stress analysis to determine the residual stress effects on the crack-opening displacement, (3) The effects of hydrostatic testing on the residual stresses and the resulting crack-opening displacement, and (4) The effect of residual stresses on crack-opening displacement with different normal operating stresses.« less

Enhancement of plasma generation in catalyst pores with different shapes

NASA Astrophysics Data System (ADS)

Zhang, Yu-Ru; Neyts, Erik C.; Bogaerts, Annemie

2018-05-01

Plasma generation inside catalyst pores is of utmost importance for plasma catalysis, as the existence of plasma species inside the pores affects the active surface area of the catalyst available to the plasma species for catalytic reactions. In this paper, the electric field enhancement, and thus the plasma production inside catalyst pores with different pore shapes is studied with a two-dimensional fluid model. The results indicate that the electric field will be significantly enhanced near tip-like structures. In a conical pore with small opening, the strongest electric field appears at the opening and bottom corners of the pore, giving rise to a prominent ionization rate throughout the pore. For a cylindrical pore, the electric field is only enhanced at the bottom corners of the pore, with lower absolute value, and thus the ionization rate inside the pore is only slightly enhanced. Finally, in a conical pore with large opening, the electric field is characterized by a maximum at the bottom of the pore, yielding a similar behavior for the ionization rate. These results demonstrate that the shape of the pore has a significantly influence on the electric field enhancement, and thus modifies the plasma properties.

CALUTRON

DOEpatents

Lofgren, E.J.

1960-01-19

An ion source suitable for use with isotope separators of the calutron class is described in which ion bombardment of source structural members is minimized to lessen deterioration. A hollow conducting block defines an arc chamber which has an ion exit opening in the form of a slot in one wall of the block. A charged electrode spaced from the opening applies an electrical field for withdrawing ions from within the block. To establish a field configuration whereby the impingement of ions on the walls of the block is reduced, the wall edges which define the slot opening are bevelled to converge in the direction of efflux of the ions.

Designing Input Fields for Non-Narrative Open-Ended Responses in Web Surveys

PubMed Central

Couper, Mick P.; Kennedy, Courtney; Conrad, Frederick G.; Tourangeau, Roger

2012-01-01

Web surveys often collect information such as frequencies, currency amounts, dates, or other items requiring short structured answers in an open-ended format, typically using text boxes for input. We report on several experiments exploring design features of such input fields. We find little effect of the size of the input field on whether frequency or dollar amount answers are well-formed or not. By contrast, the use of templates to guide formatting significantly improves the well-formedness of responses to questions eliciting currency amounts. For date questions (whether month/year or month/day/year), we find that separate input fields improve the quality of responses over single input fields, while drop boxes further reduce the proportion of ill-formed answers. Drop boxes also reduce completion time when the list of responses is short (e.g., months), but marginally increases completion time when the list is long (e.g., birth dates). These results suggest that non-narrative open questions can be designed to help guide respondents to provide answers in the desired format. PMID:23411468

First field demonstration of cloud datacenter workflow automation employing dynamic optical transport network resources under OpenStack and OpenFlow orchestration.

PubMed

Szyrkowiec, Thomas; Autenrieth, Achim; Gunning, Paul; Wright, Paul; Lord, Andrew; Elbers, Jörg-Peter; Lumb, Alan

2014-02-10

For the first time, we demonstrate the orchestration of elastic datacenter and inter-datacenter transport network resources using a combination of OpenStack and OpenFlow. Programmatic control allows a datacenter operator to dynamically request optical lightpaths from a transport network operator to accommodate rapid changes of inter-datacenter workflows.

Open Drug Discovery Toolkit (ODDT): a new open-source player in the drug discovery field.

PubMed

Wójcikowski, Maciej; Zielenkiewicz, Piotr; Siedlecki, Pawel

2015-01-01

There has been huge progress in the open cheminformatics field in both methods and software development. Unfortunately, there has been little effort to unite those methods and software into one package. We here describe the Open Drug Discovery Toolkit (ODDT), which aims to fulfill the need for comprehensive and open source drug discovery software. The Open Drug Discovery Toolkit was developed as a free and open source tool for both computer aided drug discovery (CADD) developers and researchers. ODDT reimplements many state-of-the-art methods, such as machine learning scoring functions (RF-Score and NNScore) and wraps other external software to ease the process of developing CADD pipelines. ODDT is an out-of-the-box solution designed to be easily customizable and extensible. Therefore, users are strongly encouraged to extend it and develop new methods. We here present three use cases for ODDT in common tasks in computer-aided drug discovery. Open Drug Discovery Toolkit is released on a permissive 3-clause BSD license for both academic and industrial use. ODDT's source code, additional examples and documentation are available on GitHub (https://github.com/oddt/oddt).

Evaluating the dose to the contralateral breast when using a dynamic wedge versus a regular wedge.

PubMed

Weides, C D; Mok, E C; Chang, W C; Findley, D O; Shostak, C A

1995-01-01

The incidence of secondary cancers in the contralateral breast after primary breast irradiation is several times higher than the incidence of first time breast cancer. Studies have shown that the scatter radiation to the contralateral breast may play a large part in the induction of secondary breast cancers. Factors that may contribute to the contralateral breast dose may include the use of blocks, the orientation of the field, and wedges. Reports have shown that the use of regular wedges, particularly for the medial tangential field, gives a significantly higher dose to the contralateral breast compared to an open field. This paper compares the peripheral dose outside the field using a regular wedge, a dynamic wedge, and an open field technique. The data collected consisted of measurements taken with patients, solid water and a Rando phantom using a Varian 2300CD linear accelerator. Ion chambers, thermoluminescent dosimeters (TLD), diodes, and films were the primary means for collecting the data. The measurements show that the peripheral dose outside the field using a dynamic wedge is close to that of open fields, and significantly lower than that of regular wedges. This information indicates that when using a medial wedge, a dynamic wedge should be used.

Simulation of future global warming scenarios in rice paddies with an open-field warming facility

PubMed Central

2011-01-01

To simulate expected future global warming, hexagonal arrays of infrared heaters have previously been used to warm open-field canopies of upland crops such as wheat. Through the use of concrete-anchored posts, improved software, overhead wires, extensive grounding, and monitoring with a thermal camera, the technology was safely and reliably extended to paddy rice fields. The system maintained canopy temperature increases within 0.5°C of daytime and nighttime set-point differences of 1.3 and 2.7°C 67% of the time. PMID:22145582

Social Effects on Rat Spatial Choice in an Open Field Task

ERIC Educational Resources Information Center

Keller, Matthew R.; Brown, Michael F.

2011-01-01

Pairs of rats foraged in trials either together or separately in an open field apparatus for pellets hidden in discreet locations in a 5 x 5 matrix. Trial duration was either 1 or 4 min. The tendency to choose locations that had earlier been visited by another rat was examined by comparing the choices made in the presence and absence of the other…

The Use of an Open Field Model to Assess Sound-Induced Fear and Anxiety Associated Behaviors in Labrador Retrievers.

PubMed

Gruen, Margaret E; Case, Beth C; Foster, Melanie L; Lazarowski, Lucia; Fish, Richard E; Landsberg, Gary; DePuy, Venita; Dorman, David C; Sherman, Barbara L

2015-01-01

Previous studies have shown that the playing of thunderstorm recordings during an open-field task elicits fearful or anxious responses in adult beagles. The goal of our study was to apply this open field test to assess sound-induced behaviors in Labrador retrievers drawn from a pool of candidate improvised explosive devices (IED)-detection dogs. Being robust to fear-inducing sounds and recovering quickly is a critical requirement of these military working dogs. This study presented male and female dogs, with 3 minutes of either ambient noise (Days 1, 3 and 5), recorded thunderstorm (Day 2), or gunfire (Day 4) sounds in an open field arena. Behavioral and physiological responses were assessed and compared to control (ambient noise) periods. An observer blinded to sound treatment analyzed video records of the 9-minute daily test sessions. Additional assessments included measurement of distance traveled (activity), heart rate, body temperature, and salivary cortisol concentrations. Overall, there was a decline in distance traveled and heart rate within each day and over the five-day test period, suggesting that dogs habituated to the open field arena. Behavioral postures and expressions were assessed using a standardized rubric to score behaviors linked to canine fear and anxiety. These fear/anxiety scores were used to evaluate changes in behaviors following exposure to a sound stressor. Compared to control periods, there was an overall increase in fear/anxiety scores during thunderstorm and gunfire sound stimuli treatment periods. Fear/anxiety scores were correlated with distance traveled, and heart rate. Fear/anxiety scores in response to thunderstorm and gunfire were correlated. Dogs showed higher fear/anxiety scores during periods after the sound stimuli compared to control periods. In general, candidate IED-detection Labrador retrievers responded to sound stimuli and recovered quickly, although dogs stratified in their response to sound stimuli. Some dogs were robust to fear/anxiety responses. The results suggest that the open field sound test may be a useful method to evaluate the suitability of dogs for IED-detection training.

The Use of an Open Field Model to Assess Sound-Induced Fear and Anxiety Associated Behaviors in Labrador Retrievers

PubMed Central

Gruen, Margaret E.; Case, Beth C.; Foster, Melanie L.; Lazarowski, Lucia; Fish, Richard E.; Landsberg, Gary; DePuy, Venita; Dorman, David C.; Sherman, Barbara L.

2015-01-01

Previous studies have shown that the playing of thunderstorm recordings during an open-field task elicits fearful or anxious responses in adult beagles. The goal of our study was to apply this open field test to assess sound-induced behaviors in Labrador retrievers drawn from a pool of candidate improvised explosive devices (IED)-detection dogs. Being robust to fear-inducing sounds and recovering quickly is a critical requirement of these military working dogs. This study presented male and female dogs, with 3 minutes of either ambient noise (Days 1, 3 and 5), recorded thunderstorm (Day 2), or gunfire (Day 4) sounds in an open field arena. Behavioral and physiological responses were assessed and compared to control (ambient noise) periods. An observer blinded to sound treatment analyzed video records of the 9-minute daily test sessions. Additional assessments included measurement of distance traveled (activity), heart rate, body temperature, and salivary cortisol concentrations. Overall, there was a decline in distance traveled and heart rate within each day and over the five-day test period, suggesting that dogs habituated to the open field arena. Behavioral postures and expressions were assessed using a standardized rubric to score behaviors linked to canine fear and anxiety. These fear/anxiety scores were used to evaluate changes in behaviors following exposure to a sound stressor. Compared to control periods, there was an overall increase in fear/anxiety scores during thunderstorm and gunfire sound stimuli treatment periods. Fear/anxiety scores were correlated with distance traveled, and heart rate. Fear/anxiety scores in response to thunderstorm and gunfire were correlated. Dogs showed higher fear/anxiety scores during periods after the sound stimuli compared to control periods. In general, candidate IED-detection Labrador retrievers responded to sound stimuli and recovered quickly, although dogs stratified in their response to sound stimuli. Some dogs were robust to fear/anxiety responses. The results suggest that the open field sound test may be a useful method to evaluate the suitability of dogs for IED-detection training. PMID:26273235

Lakes, landscapes, and R: A framework for open science on freshwater cyanobacteria

EPA Science Inventory

In the last several years scientific reproducibility has been a hot topic with several fields openly struggling with reproducing and replicating research results. One of the key tools to address reproducibility is the use of open source software. Increasingly in ecology, the R ...

LCTLs and Technology: The Promise of Open Education

ERIC Educational Resources Information Center

Blyth, Carl

2013-01-01

LCTL educators are beginning to participate in the Open Education movement by developing and sharing their own pedagogical materials referred to as open educational resources (OERs). This new generation of collaborative LCTL materials will invariably challenge longstanding hegemonies in the fields of foreign language education and educational…

Escape for the Slow Solar Wind

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2017-05-01

Plasma from the Sun known as the slow solar wind has been observed far away from where scientists thought it was produced. Now new simulations may have resolved the puzzle of where the slow solar wind comes from and how it escapes the Sun to travel through our solar system.An Origin PuzzleA full view of a coronal hole (dark portion) from SDO. The edges of the coronal hole mark the boundary between open and closed magnetic field lines. [SDO; adapted from Higginson et al. 2017]The Suns atmosphere, known as the corona, is divided into two types of regions based on the behavior of magnetic field lines. In closed-field regions, the magnetic field is firmly anchored in the photosphere at both ends of field lines, so traveling plasma is confined to coronal loops and must return to the Suns surface. In open-field regions, only one end of each magnetic field line is anchored in the photosphere, so plasma is able to stream from the Suns surface out into the solar system.This second type of region known as a coronal hole is thought to be the origin of fast-moving plasma measured in our solar system and known as the fast solar wind. But we also observe a slow solar wind: plasma that moves at speeds of less than 500 km/s.The slow solar wind presents a conundrum. Its observational properties strongly suggest it originates in the hot, closed corona rather than the cooler, open regions. But if the slow solar wind plasma originates in closed-field regions of the Suns atmosphere, then how does it escape from the Sun?Slow Wind from Closed FieldsA team of scientists led by Aleida Higginson (University of Michigan) has now used high-resolution, three-dimensional magnetohydrodynamic simulations to show how the slow solar wind can be generated from plasma that starts outin closed-field parts of the Sun.A simulated heliospheric arc, composed of open magnetic field lines. [Higginson et al. 2017]Motions on the Suns surface near the boundary between open and closed-field regions the boundary that marks the edges of coronal holes and extends outward as the heliospheric current sheet are caused by supergranule-like convective flows. These motions drive magnetic reconnection that funnel plasma from the closed-field region onto enormous arcs that extend far away from the heliospheric current sheet, spanning tens of degrees in latitude and longitude.The simulations by Higginson and collaborators demonstrate that closed-field plasma from coronal-hole boundaries can be successfully channeled into the solar system. Due to the geometry and dynamics of the coronal holes, the plasma can travel far from the heliospheric current sheet, resulting in a slow solar wind of closed-field plasma consistent with our observations. These simulations therefore suggest aprocessthat resolves the long-standing puzzle of the slow solar wind.BonusCheck out the animation below, made from the results of the teams simulations. This video shows the location of a forming heliospheric arc at a distance of 12 solar radii. The arc forms as magnetic field lines at the boundary of a coronal hole change from closed to open, allowing closed-field flux to escape along them.http://aasnova.org/wp-content/uploads/2017/05/apjlaa6d72f4_video.mp4CitationA. K. Higginson et al 2017 ApJL 840 L10. doi:10.3847/2041-8213/aa6d72

Modelling of photodegradation in solar cell modules of substrate and superstrate design made with ethylene-vinyl acetate as pottant material

NASA Technical Reports Server (NTRS)

Somersall, A. C.; Guillet, J. E.

1983-01-01

A computer model was developed which can generate realistic concentration versus time profiles of the chemical species formed during photooxidation of hydrocarbon polymers using as input data a set of elementary reactions with corresponding rate constants and initial conditions. The results of computer simulation have been shown to be consistent with the general experimental observations of the photooxidation of polyethylene exposed to sunlight at ambient temperatures. The useful lifetime (5% oxidation) of the unstabilized polyethylene is predicted to vary from a few months in hot weather (100 F) to almost two years in cool weather (45 F) with an apparent net activation energy of 10 kcal/mol. Modelling studies of alternate mechanisms for stabilization of clear, amorphous, linear polyethylene suggest that the optimum stabilizer would be a molecularly dispensed additive in very low concentration which can trap peroxy radicals and also decompose hydroperoxides.

Post-growth process for flexible CdS/CdTe thin film solar cells with high specific power.

PubMed

Cho, Eunwoo; Kang, Yoonmook; Kim, Donghwan; Kim, Jihyun

2016-05-16

We demonstrated a flexible CdS/CdTe thin film solar cell with high specific power of approximately 254 W/kg. A flexible and ultra-light weight CdS/CdTe cell treated with pre-NP etch process exhibited high conversion efficiency of 13.56% in superstrate configuration. Morphological, structural and optical changes of CdS/CdTe thin films were characterized when pre-NP etch step was incorporated to the conventional post-deposition process. Improvement of photovoltaic parameters can be attributed to the removal of the oxide and the formation of Te-rich layer, which benefit the activation process. Pre-NP etched cell maintained their flexibility and performance under the repeated tensile strain of 0.13%. Our method can pave a way for manufacturing flexible CdS/CdTe thin film solar cells with high specific power for mobile and aerospace applications.

Inflatable lenses for space photovoltaic concentrator arrays

DOE Office of Scientific and Technical Information (OSTI.GOV)

O`Neill, M.J.; Piszczor, M.F.

1997-12-31

For 12 years, ENTECH and NASA Lewis have been developing Fresnel lens concentrator technology for space power applications. ENTECH provided the point-focus mini-dome lenses for the PASP+ array, launched in 1994. These silicone lenses performed well on orbit, with only about 3% optical performance loss after 1 year in elliptical orbit, with high radiation, atomic oxygen, and ultraviolet exposure. The only protection for these silicone lenses was a thin-film coating provided by OCLI. ENTECH also provided the line-focus lenses for the SCARLET 1 and SCARLET 2 arrays in 1995 and 1997, respectively. These lenses are laminated assemblies, with protective ceriamore » glass superstrates over the silicone lens. In March 1997, ENTECH and NASA Lewis began development of inflatable Fresnel lenses, to achieve lower weight, smaller launch volume, reduced cost, less fragility, and other advantages. This paper summarizes the new concentrator approach, including key program results to date.« less

Similes and Superstrings: Writing to Clarify the Cosmos

NASA Astrophysics Data System (ADS)

McCool, M.

2009-06-01

The way we receive information in today's digital society has radically changed. Audiences are no longer passive consumers of content, but expect to be able to access the latest news rapidly from a variety of portals and sources. The needs of this rapidly expanding tech-savvy community are being met by a community of bloggers, podcasters and vodcasters, who use a suite of textual, audio and video content to reach their audience, many of whom subscribe to and follow content they enjoy. These communicators are the new faces of public outreach and journalism, and they are most effective when closest to the action. This desire to bring online audiences into the conference room alongside the scientists and professionals had led to the development of liveblogging. The idea is simple; anyone sitting somewhere interesting only needs a connection to the internet to report their experiences in real time.

Fast spinning strings on η deformed AdS 5 × S 5

NASA Astrophysics Data System (ADS)

Banerjee, Aritra; Bhattacharyya, Arpan; Roychowdhury, Dibakar

2018-02-01

In this paper, considering the correspondence between spin chains and string sigma models, we explore the rotating string solutions over η deformed AdS 5 × S 5 in the so-called fast spinning limit. In our analysis, we focus only on the bosonic part of the full superstring action and compute the relevant limits on both ( R × S 3) η and ( R × S 5) η models. The resulting system reveals that in the fast spinning limit, the sigma model on η deformed S 5 could be approximately thought of as the continuum limit of anisotropic SU(3) Heisenberg spin chain model. We compute the energy for a certain class of spinning strings in deformed S 5 and we show that this energy can be mapped to that of a similar spinning string in the purely imaginary β deformed background.

Development of UV-curable liquid for in-liquid fluorescence alignment in ultraviolet nanoimprint lithography

NASA Astrophysics Data System (ADS)

Ochiai, Kento; Kikuchi, Eri; Ishito, Yota; Kumagai, Mari; Nakamura, Takahiro; Nakagawa, Masaru

2018-06-01

We studied a fluorescent UV-curable resin suitable for fluorescence alignment in UV nanoimprinting. The addition of a cationic fluorescent dye caused radical photopolymerization of a UV-curable resin by exposure to visible excitation light for fluorescence microscope observation. The microscope observation of a resin film prepared by pressing resin droplets on a silica substrate with a fluorinated silica superstrate revealed that the cationic dye molecules were preferably adsorbed onto the silica surface. It was indicated that the dye molecules concentrated on the silica surface may cause the photocuring. A nonionic fluorescent dye was selected owing to its low polar symmetrical structure and its solubility parameter close to monomers. The fluorescent UV-curable resin with the nonionic dye showed uncured stability to exposure to visible excitation light for 30 min with a light intensity of 8.5 mW cm‑2 detected at 530 nm.

The New Physics

NASA Astrophysics Data System (ADS)

Fraser, Gordon

2006-04-01

Introduction Gordon Fraser; Part I. Matter and the Universe: 1. Cosmology Wendy Freedman and Rocky Kolb; 2. Gravity Ronald Adler; 3. Astrophysics Arnon Dar; 4. Particles and the standard model Chris Quigg; 5. Superstrings Michael Green; Part II. Quantum Matter: 6. Atoms and photons Claude Cohen-Tannoudji and Jean Dalibard; 7. The quantum world of ultra-cold atoms Christopher Foot and William Phillips; 8. Superfluidity Henry Hall; 9. Quantum phase transitions Subir Sachdev; Part III. Quanta in Action: 10. Quantum entanglement Anton Zeilinger; 11. Quanta, ciphers and computers Artur Ekert; 12. Small-scale structure and nanoscience Yoseph Imry; Part IV. Calculation and Computation: 13. Nonlinearity Henry Abarbanel; 14. Complexity Antonio Politi; 15. Collaborative physics, e-science and the grid Tony Hey and Anne Trefethen; Part V. Science in Action: 16. Biophysics Cyrus Safinya; 17. Medical physics Nicolaj Pavel; 18. Physics and materials Robert Cahn; 19. Physics and society Ugo Amaldi.

The New Physics

NASA Astrophysics Data System (ADS)

Fraser, Gordon

2009-08-01

Introduction Gordon Fraser; Part I. Matter and the Universe: 1. Cosmology Wendy Freedman and Rocky Kolb; 2. Gravity Ronald Adler; 3. Astrophysics Arnon Dar; 4. Particles and the standard model Chris Quigg; 5. Superstrings Michael Green; Part II. Quantum Matter: 6. Atoms and photons Claude Cohen-Tannoudji and Jean Dalibard; 7. The quantum world of ultra-cold atoms Christopher Foot and William Phillips; 8. Superfluidity Henry Hall; 9. Quantum phase transitions Subir Sachdev; Part III. Quanta in Action: 10. Quantum entanglement Anton Zeilinger; 11. Quanta, ciphers and computers Artur Ekert; 12. Small-scale structure and nanoscience Yoseph Imry; Part IV. Calculation and Computation: 13. Nonlinearity Henry Abarbanel; 14. Complexity Antonio Politi; 15. Collaborative physics, e-science and the grid Tony Hey and Anne Trefethen; Part V. Science in Action: 16. Biophysics Cyrus Safinya; 17. Medical physics Nicolaj Pavel; 18. Physics and materials Robert Cahn; 19. Physics and society Ugo Amaldi.

Polymer substrates for flexible photovoltaic cells application in personal electronic system

NASA Astrophysics Data System (ADS)

Znajdek, K.; Sibiński, M.; Strąkowska, A.; Lisik, Z.

2016-01-01

The article presents an overview of polymeric materials for flexible substrates in photovoltaic (PV) structures that could be used as power supply in the personal electronic systems. Four types of polymers have been elected for testing. The first two are the most specialized and heat resistant polyimide films. The third material is transparent polyethylene terephthalate film from the group of polyesters which was proposed as a cheap and commercially available substrate for the technology of photovoltaic cells in a superstrate configuration. The last selected polymeric material is a polysiloxane, which meets the criteria of high elasticity, is temperature resistant and it is also characterized by relatively high transparency in the visible light range. For the most promising of these materials additional studies were performed in order to select those of them which represent the best optical, mechanical and temperature parameters according to their usage for flexible substrates in solar cells.

APT mass spectrometry and SEM data for CdTe solar cells

DOE PAGES

Li, Chen; Paudel, Naba R.; Yan, Yanfa; ...

2016-03-16

Atom probe tomography (APT) data acquired from a CAMECA LEAP 4000 XHR for the CdS/CdTe interface for a non-CdCl 2 treated CdTe solar cell as well as the mass spectrum of an APT data set including a GB in a CdCl 2-treated CdTe solar cell are presented. Scanning electron microscopy (SEM) data showing the evolution of sample preparation for APT and scanning transmission electron microscopy (STEM) electron beam induced current (EBIC) are also presented. As a result, these data show mass spectrometry peak decomposition of Cu and Te within an APT dataset, the CdS/CdTe interface of an untreated CdTe solarmore » cell, preparation of APT needles from the CdS/CdTe interface in superstrate grown CdTe solar cells, and the preparation of a cross-sectional STEM EBIC sample.« less

Vapor transport deposition of antimony selenide thin film solar cells with 7.6% efficiency.

PubMed

Wen, Xixing; Chen, Chao; Lu, Shuaicheng; Li, Kanghua; Kondrotas, Rokas; Zhao, Yang; Chen, Wenhao; Gao, Liang; Wang, Chong; Zhang, Jun; Niu, Guangda; Tang, Jiang

2018-06-05

Antimony selenide is an emerging promising thin film photovoltaic material thanks to its binary composition, suitable bandgap, high absorption coefficient, inert grain boundaries and earth-abundant constituents. However, current devices produced from rapid thermal evaporation strategy suffer from low-quality film and unsatisfactory performance. Herein, we develop a vapor transport deposition technique to fabricate antimony selenide films, a technique that enables continuous and low-cost manufacturing of cadmium telluride solar cells. We improve the crystallinity of antimony selenide films and then successfully produce superstrate cadmium sulfide/antimony selenide solar cells with a certified power conversion efficiency of 7.6%, a net 2% improvement over previous 5.6% record of the same device configuration. We analyze the deep defects in antimony selenide solar cells, and find that the density of the dominant deep defects is reduced by one order of magnitude using vapor transport deposition process.

Magnetic Topology and Ion Outflow in Mars' Magnetotail

NASA Astrophysics Data System (ADS)

Mitchell, D. L.; Xu, S.; McFadden, J. P.; Hara, T.; Luhmann, J. G.; Mazelle, C. X.; Andersson, L.; DiBraccio, G. A.; Connerney, J. E. P.

2017-12-01

Planetary ion outflow down the Martian magnetotail could be an important atmospheric loss mechanism. This process depends on magnetic connectivity to the day-side ionosphere and on acceleration of ions to escape velocity. The Mars Atmosphere and Volatile Evolution (MAVEN) mission has obtained comprehensive ion, electron, and magnetic field data in Mars' magnetotail. The spacecraft is in a 75°-inclination, elliptical orbit that samples altitudes from 150 to 6200 km. As the orbit precesses, it sweeps through the tail at a variety of altitudes in this range. Data from the Solar Wind Electron Analyzer (SWEA) and Magnetometer (MAG) are used to determine the magnetic field topology in the tail at high cadence (every 2-4 seconds), and in particular whether field lines are open, closed, or draped, and if open whether they have access to the day-side or night-side ionosphere. Simultaneous observations by the Supra-Thermal and Thermal Ion Composition (STATIC) instrument and the Langmuir Probe and Waves (LPW) experiment are used to measure the density, composition, and velocity of planetary plasma on these field lines. We find that magnetic topology in the tail is complex and variable, and is influenced by the IMF polarity and the orientation of Mars' crustal magnetic fields with respect to the Sun. We find that planetary ion outflow occurs on both open and draped field lines. On open field lines, outflow tends to occur parallel to the field line, with colder, denser, and slower outflow on field lines connected to the day-side ionosphere (Fig. 1). On these same field lines (after correction for the spacecraft potential) a shift in the position of the He-II photoelectron feature indicates a 1-Volt parallel electric potential directed away from the planet. Except for H+ and occasionally O+, this potential is insufficient by itself to accelerate planetary ions to escape velocity. Outflow is warmer, less dense, and faster moving on draped field lines. In this case, the ion bulk velocity can be at large angles to the magnetic field, suggesting JxB acceleration. This indicates that more than one mechanism is responsible for accelerating ions into the tail.

Focused opening of the sylvian fissure for microsurgical management of MCA aneurysms.

PubMed

Elsharkawy, Ahmed; Niemelä, Mika; Lehečka, Martin; Lehto, Hanna; Jahromi, Behnam Rezai; Goehre, Felix; Kivisaari, Riku; Hernesniemi, Juha

2014-01-01

A wide sylvian opening, with either a proximal or distal start, has been standard for microsurgical management of middle cerebral artery (MCA) aneurysms. However, extensive sylvian dissection is potentially associated with increased incidence of iatrogenic injury to the brain and neurovascular structures. The aim of the present study was to describe the technique of focused opening of the sylvian fissure for microsurgical management of MCA aneurysms with additional tips on handling difficulties which may be encountered with this technique. A 3D image-based anatomic orientation, clipping field-focused surgical planning, slack brain, and high magnification are the basic requirements for this approach. A 10-15 mm sylvian opening is placed so that it allows safe access and a good surgical view of the MCA aneurysm clipping field. Under proximal control of the MCA, the aneurysm neck can be dissected and clipped effectively and safely, in this small surgical field. The presented technique has been developed and refined by the senior author during the surgery of 1,097 aneurysms over the last 13 years. It has proved to be safe, and effective for clipping of both ruptured and unruptured MCA aneurysms. Its greatest advantages are a shorter operative time and less brain and vessel manipulation compared to more extensive approaches. The focused sylvian opening is a less-invasive alternative to the classical wide sylvian opening for the microsurgical management of most MCA aneurysms.

Direct Synthesis of Carbon Nanotube Field Emitters on Metal Substrate for Open-Type X-ray Source in Medical Imaging.

PubMed

Gupta, Amar Prasad; Park, Sangjun; Yeo, Seung Jun; Jung, Jaeik; Cho, Chonggil; Paik, Sang Hyun; Park, Hunkuk; Cho, Young Chul; Kim, Seung Hoon; Shin, Ji Hoon; Ahn, Jeung Sun; Ryu, Jehwang

2017-07-29

We report the design, fabrication and characterization of a carbon nanotube enabled open-type X-ray system for medical imaging. We directly grew the carbon nanotubes used as electron emitter for electron gun on a non-polished raw metallic rectangular-rounded substrate with an area of 0.1377 cm² through a plasma enhanced chemical vapor deposition system. The stable field emission properties with triode electrodes after electrical aging treatment showed an anode emission current of 0.63 mA at a gate field of 7.51 V/μm. The 4.5-inch cubic shape open type X-ray system was developed consisting of an X-ray aperture, a vacuum part, an anode high voltage part, and a field emission electron gun including three electrodes with focusing, gate and cathode electrodes. Using this system, we obtained high-resolution X-ray images accelerated at 42-70 kV voltage by digital switching control between emitter and ground electrode.

Direct Synthesis of Carbon Nanotube Field Emitters on Metal Substrate for Open-Type X-ray Source in Medical Imaging

PubMed Central

Gupta, Amar Prasad; Park, Sangjun; Yeo, Seung Jun; Jung, Jaeik; Cho, Chonggil; Paik, Sang Hyun; Park, Hunkuk; Cho, Young Chul; Kim, Seung Hoon; Shin, Ji Hoon; Ahn, Jeung Sun; Ryu, Jehwang

2017-01-01

We report the design, fabrication and characterization of a carbon nanotube enabled open-type X-ray system for medical imaging. We directly grew the carbon nanotubes used as electron emitter for electron gun on a non-polished raw metallic rectangular-rounded substrate with an area of 0.1377 cm2 through a plasma enhanced chemical vapor deposition system. The stable field emission properties with triode electrodes after electrical aging treatment showed an anode emission current of 0.63 mA at a gate field of 7.51 V/μm. The 4.5-inch cubic shape open type X-ray system was developed consisting of an X-ray aperture, a vacuum part, an anode high voltage part, and a field emission electron gun including three electrodes with focusing, gate and cathode electrodes. Using this system, we obtained high-resolution X-ray images accelerated at 42–70 kV voltage by digital switching control between emitter and ground electrode. PMID:28773237

Frequency dependence of the acoustic field generated from a spherical cavity transducer with open ends

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Faqi; Zeng, Deping; He, Min

2015-12-15

Resolution of high intensity focused ultrasound (HIFU) focusing is limited by the wave diffraction. We have developed a spherical cavity transducer with two open ends to improve the focusing precision without sacrificing the acoustic intensity (App Phys Lett 2013; 102: 204102). This work aims to theoretically and experimentally investigate the frequency dependence of the acoustic field generated from the spherical cavity transducer with two open ends. The device emits high intensity ultrasound at the frequency ranging from 420 to 470 kHz, and the acoustic field is measured by a fiber optic probe hydrophone. The measured results shows that the sphericalmore » cavity transducer provides high acoustic intensity for HIFU treatment only in its resonant modes, and a series of resonant frequencies can be choosen. Furthermore, a finite element model is developed to discuss the frequency dependence of the acoustic field. The numerical simulations coincide well with the measured results.« less

Neuromotor tolerability and behavioural characterisation of cannabidiolic acid, a phytocannabinoid with therapeutic potential for anticipatory nausea.

PubMed

Brierley, Daniel I; Samuels, James; Duncan, Marnie; Whalley, Benjamin J; Williams, Claire M

2016-01-01

Anticipatory nausea (AN) is a poorly controlled side effect experienced by chemotherapy patients. Currently, pharmacotherapy is restricted to benzodiazepine anxiolytics, which have limited efficacy, have significant sedative effects and induce dependency. The non-psychoactive phytocannabinoid, cannabidiolic acid (CBDA), has shown considerable efficacy in pre-clinical AN models, however determination of its neuromotor tolerability profile is crucial to justify clinical investigation. Provisional evidence for appetite-stimulating properties also requires detailed investigation. This study aims to assess the tolerability of CBDA in locomotor activity, motor coordination and muscular strength tests, and additionally for ability to modulate feeding behaviours. Male Lister Hooded rats administered CBDA (0.05-5 mg/kg; p.o.) were assessed in habituated open field (for locomotor activity), static beam and grip strength tests. A further study investigated whether these CBDA doses modulated normal feeding behaviour. Finally, evidence of anxiolytic-like effects in the habituated open field prompted testing of 5 mg/kg CBDA for anxiolytic-like activity in unhabituated open field, light/dark box and novelty-suppressed feeding (NSF) tests. CBDA had no adverse effects upon performance in any neuromotor tolerability test, however anxiolytic-like behaviour was observed in the habituated open field. Normal feeding behaviours were unaffected by any dose. CBDA (5 mg/kg) abolished the increased feeding latency in the NSF test induced by the 5-HT1AR antagonist, WAY-100,635, indicative of anxiolytic-like effects, but had no effect on anxiety-like behaviour in the novel open field or light/dark box. CBDA is very well tolerated and devoid of the sedative side effect profile of benzodiazepines, justifying its clinical investigation as a novel AN treatment.

A high frequency analysis of electromagnetic plane wave scattering by perfectly-conducting semi-infinite parallel plate and rectangular waveguides with absorber coated inner walls

NASA Technical Reports Server (NTRS)

Noh, H. M.; Pathak, P. H.

1986-01-01

An approximate but sufficiently accurate high frequency solution which combines the uniform geometrical theory of diffraction (UTD) and the aperture integration (AI) method is developed for analyzing the problem of electromagnetic (EM) plane wave scattering by an open-ended, perfectly-conducting, semi-infinite hollow rectangular waveguide (or duct) with a thin, uniform layer of lossy or absorbing material on its inner wall, and with a planar termination inside. In addition, a high frequency solution for the EM scattering by a two dimensional (2-D), semi-infinite parallel plate waveguide with a absorber coating on the inner walls is also developed as a first step before analyzing the open-ended semi-infinite three dimensional (3-D) rectangular waveguide geometry. The total field scattered by the semi-infinite waveguide consists firstly of the fields scattered from the edges of the aperture at the open-end, and secondly of the fields which are coupled into the waveguide from the open-end and then reflected back from the interior termination to radiate out of the open-end. The first contribution to the scattered field can be found directly via the UTD ray method. The second contribution is found via the AI method which employs rays to describe the fields in the aperture that arrive there after reflecting from the interior termination. It is assumed that the direction of the incident plane wave and the direction of observation lie well inside the forward half space tht exists outside the half space containing the semi-infinite waveguide geometry. Also, the medium exterior to the waveguide is assumed to be free space.

Similar reliability and equivalent performance of female and male mice in the open field and water‐maze place navigation task

PubMed Central

Fritz, Ann‐Kristina; Amrein, Irmgard

2017-01-01

Although most nervous system diseases affect women and men differentially, most behavioral studies using mouse models do not include subjects of both sexes. Many researchers worry that data of female mice may be unreliable due to the estrous cycle. Here, we retrospectively evaluated sex effects on coefficient of variation (CV) in 5,311 mice which had performed the same place navigation protocol in the water‐maze and in 4,554 mice tested in the same open field arena. Confidence intervals for Cohen's d as measure of effect size were computed and tested for equivalence with 0.2 as equivalence margin. Despite the large sample size, only few behavioral parameters showed a significant sex effect on CV. Confidence intervals of effect size indicated that CV was either equivalent or showed a small sex difference at most, accounting for less than 2% of total group to group variation of CV. While female mice were potentially slightly more variable in water‐maze acquisition and in the open field, males tended to perform less reliably in the water‐maze probe trial. In addition to evaluating variability, we also directly compared mean performance of female and male mice and found them to be equivalent in both water‐maze place navigation and open field exploration. Our data confirm and extend other large scale studies in demonstrating that including female mice in experiments does not cause a relevant increase of data variability. Our results make a strong case for including mice of both sexes whenever open field or water‐maze are used in preclinical research. PMID:28654717

Variations of solar, interplanetary, and geomagnetic parameters with solar magnetic multipole fields during Solar Cycles 21-24

NASA Astrophysics Data System (ADS)

Kim, Bogyeong; Lee, Jeongwoo; Yi, Yu; Oh, Suyeon

2015-01-01

In this study we compare the temporal variations of the solar, interplanetary, and geomagnetic (SIG) parameters with that of open solar magnetic flux from 1976 to 2012 (from Solar Cycle 21 to the early phase of Cycle 24) for a purpose of identifying their possible relationships. By the open flux, we mean the average magnetic field over the source surface (2.5 solar radii) times the source area as defined by the potential field source surface (PFSS) model of the Wilcox Solar Observatory (WSO). In our result, most SIG parameters except the solar wind dynamic pressure show rather poor correlations with the open solar magnetic field. Good correlations are recovered when the contributions from individual multipole components are counted separately. As expected, solar activity indices such as sunspot number, total solar irradiance, 10.7 cm radio flux, and solar flare occurrence are highly correlated with the flux of magnetic quadrupole component. The dynamic pressure of solar wind is strongly correlated with the dipole flux, which is in anti-phase with Solar Cycle (SC). The geomagnetic activity represented by the Ap index is correlated with higher order multipole components, which show relatively a slow time variation with SC. We also found that the unusually low geomagnetic activity during SC 23 is accompanied by the weak open solar fields compared with those in other SCs. It is argued that such dependences of the SIG parameters on the individual multipole components of the open solar magnetic flux may clarify why some SIG parameters vary in phase with SC and others show seemingly delayed responses to SC variation.

Similar reliability and equivalent performance of female and male mice in the open field and water-maze place navigation task.

PubMed

Fritz, Ann-Kristina; Amrein, Irmgard; Wolfer, David P

2017-09-01

Although most nervous system diseases affect women and men differentially, most behavioral studies using mouse models do not include subjects of both sexes. Many researchers worry that data of female mice may be unreliable due to the estrous cycle. Here, we retrospectively evaluated sex effects on coefficient of variation (CV) in 5,311 mice which had performed the same place navigation protocol in the water-maze and in 4,554 mice tested in the same open field arena. Confidence intervals for Cohen's d as measure of effect size were computed and tested for equivalence with 0.2 as equivalence margin. Despite the large sample size, only few behavioral parameters showed a significant sex effect on CV. Confidence intervals of effect size indicated that CV was either equivalent or showed a small sex difference at most, accounting for less than 2% of total group to group variation of CV. While female mice were potentially slightly more variable in water-maze acquisition and in the open field, males tended to perform less reliably in the water-maze probe trial. In addition to evaluating variability, we also directly compared mean performance of female and male mice and found them to be equivalent in both water-maze place navigation and open field exploration. Our data confirm and extend other large scale studies in demonstrating that including female mice in experiments does not cause a relevant increase of data variability. Our results make a strong case for including mice of both sexes whenever open field or water-maze are used in preclinical research. © 2017 The Authors. American Journal of Medical Genetics Part C Published by Wiley Periodicals, Inc.

Monosodium glutamate-associated alterations in open field, anxiety-related and conditioned place preference behaviours in mice.

PubMed

Onaolapo, Olakunle James; Aremu, Olaleye Samuel; Onaolapo, Adejoke Yetunde

2017-07-01

The present study investigated changes in behaviour associated with oral monosodium glutamate (a flavouring agent), using the open field, elevated plus maze and conditioned place preference (CPP) paradigms, respectively. Mice were assigned to two groups for CPP [monosodium glutamate (MSG)-naïve (n = 40) and MSG-pretreated (n = 40)] and two groups for open field (OF) and elevated plus maze (EPM) tests [n = 40 each], respectively. Animals in respective groups were then divided into four subgroups (n = 10) (vehicle or MSG (80, 160 and 320 mg/kg)). MSG-naïve mice were observed in the CPP box in three phases (pre-conditioning, conditioning and post-conditioning). Mice were conditioned to MSG or an equivalent volume of saline. The MSG pretreatment group received vehicle or respective doses of MSG daily for 21 days, prior to conditioning. Mice in the OF or EPM groups received vehicle or doses of MSG (orally) for 21 days, at 10 ml/kg. Open field or EPM behaviours were assessed on days 1 and 21. At the end of the experiments, mice in the OF groups were sacrificed and brain homogenates used to assay glutamate and glutamine. Results showed that administration of MSG was associated with a decrease in rearing, dose-related mixed horizontal locomotor, grooming and anxiety-related response and an increase in brain glutamate/glutamine levels. Following exposure to the CPP paradigm, MSG-naïve and MSG-pretreated mice both showed 'drug-paired' chamber preference. The study concluded that MSG (at the administered doses) was associated with changes in open field activities, anxiety-related behaviours and brain glutamate/glutamine levels; its ingestion also probably leads to a stimulation of the brain reward system.

Clinical effects of buprenorphine on open field behaviour and gait symmetry in healthy and lame weaned piglets.

PubMed

Meijer, Ellen; van Nes, Arie; Back, Willem; van der Staay, Franz Josef

2015-12-01

Lameness in pigs decreases animal welfare and economic profit for the farmer. An important reason for impaired welfare in lame animals is pain due to lameness. No direct measurement of pain is possible in animals, and methods to indirectly detect and quantify the amount of pain an animal is experiencing are urgently needed. In this study, two methods to assess pain associated with lameness in pigs were evaluated to determine if they were sensitive enough to detect a lameness reduction as an effect of an experimental analgesic medication. Asymmetry associated with lameness was objectively quantified using pressure mat kinetic parameters: peak vertical force (PVF), load rate (LR), vertical impulse (VI) and peak vertical pressure (PVP). Locomotor activity was assessed in an open field test. A dose of 0.04 mg/kg buprenorphine, a strong analgesic, was used to treat 10 lame pigs, while eight other lame pigs, treated with physiological saline solution, served as controls. Buprenorphine decreased lameness-associated asymmetry for pressure mat LR (P = 0.002), VI (P = 0.003) and PVP (P = 0.001) and increased activity of the lame pigs in the open field (P = 0.023), while saline-treated animals did not show any changes in asymmetry and became less active in the open field (P <0.001). It was concluded that measurement of gait asymmetry by pressure mat analysis and locomotor activity in an open field test are both sensitive enough to detect the analgesic effects of buprenorphine when used to treat moderate to severe clinical pain in a relatively small group of affected pigs. The methods used in this study may also provide promising additional tools for future research into early pain recognition and lameness treatment in pigs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Characterizing the Utility and Limitations of Repurposing an Open-Field Optical Imaging Device for Fluorescence-Guided Surgery in Head and Neck Cancer Patients.

PubMed

Moore, Lindsay S; Rosenthal, Eben L; Chung, Thomas K; de Boer, Esther; Patel, Neel; Prince, Andrew C; Korb, Melissa L; Walsh, Erika M; Young, E Scott; Stevens, Todd M; Withrow, Kirk P; Morlandt, Anthony B; Richman, Joshua S; Carroll, William R; Zinn, Kurt R; Warram, Jason M

2017-02-01

The purpose of this study was to assess the potential of U.S. Food and Drug Administration-cleared devices designed for indocyanine green-based perfusion imaging to identify cancer-specific bioconjugates with overlapping excitation and emission wavelengths. Recent clinical trials have demonstrated potential for fluorescence-guided surgery, but the time and cost of the approval process may impede clinical translation. To expedite this translation, we explored the feasibility of repurposing existing optical imaging devices for fluorescence-guided surgery. Consenting patients (n = 15) scheduled for curative resection were enrolled in a clinical trial evaluating the safety and specificity of cetuximab-IRDye800 (NCT01987375). Open-field fluorescence imaging was performed preoperatively and during the surgical resection. Fluorescence intensity was quantified using integrated instrument software, and the tumor-to-background ratio characterized fluorescence contrast. In the preoperative clinic, the open-field device demonstrated potential to guide preoperative mapping of tumor borders, optimize the day of surgery, and identify occult lesions. Intraoperatively, the device demonstrated robust potential to guide surgical resections, as all peak tumor-to-background ratios were greater than 2 (range, 2.2-14.1). Postresection wound bed fluorescence was significantly less than preresection tumor fluorescence (P < 0.001). The repurposed device also successfully identified positive margins. The open-field imaging device was successfully repurposed to distinguish cancer from normal tissue in the preoperative clinic and throughout surgical resection. This study illuminated the potential for existing open-field optical imaging devices with overlapping excitation and emission spectra to be used for fluorescence-guided surgery. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

Chronic Toxoplasma gondii in Nurr1-Null Heterozygous Mice Exacerbates Elevated Open Field Activity

PubMed Central

Eells, Jeffrey B.; Varela-Stokes, Andrea; Guo-Ross, Shirley X.; Kummari, Evangel; Smith, Holly M.; Cox, Erin; Lindsay, David S.

2015-01-01

Latent infection with Toxoplasma gondii is common in humans (approximately 30% of the global population) and is a significant risk factor for schizophrenia. Since prevalence of T. gondii infection is far greater than prevalence of schizophrenia (0.5-1%), genetic risk factors are likely also necessary to contribute to schizophrenia. To test this concept in an animal model, Nurr1-null heterozygous (+/-) mice and wild-type (+/+) mice were evaluate using an emergence test, activity in an open field and with a novel object, response to bobcat urine and prepulse inhibition of the acoustic startle response (PPI) prior to and 6 weeks after infection with T. gondii. In the emergence test, T. gondii infection significantly decreased the amount of time spent in the cylinder. Toxoplasma gondii infection significantly elevated open field activity in both +/+ and +/- mice but this increase was significantly exacerbated in +/- mice. T. gondii infection reduced PPI in male +/- mice but this was not statistically significant. Aversion to bobcat urine was abolished by T. gondii infection in +/+ mice. In female +/- mice, aversion to bobcat urine remained after T. gondii infection while the male +/- mice showed no aversion to bobcat urine. Antibody titers of infected mice were a critical variable associated with changes in open field activity, such that an inverted U shaped relationship existed between antibody titers and the percent change in open field activity with a significant increase in activity at low and medium antibody titers but no effect at high antibody titers. These data demonstrate that the Nurr1 +/- genotype predisposes mice to T. gondii-induced alterations in behaviors that involve dopamine neurotransmission and are associated with symptoms of schizophrenia. We propose that these alterations in murine behavior were due to further exacerbation of the altered dopamine neurotransmission in Nurr1 +/- mice. PMID:25855987

Chronic Toxoplasma gondii in Nurr1-null heterozygous mice exacerbates elevated open field activity.

PubMed

Eells, Jeffrey B; Varela-Stokes, Andrea; Guo-Ross, Shirley X; Kummari, Evangel; Smith, Holly M; Cox, Erin; Lindsay, David S

2015-01-01

Latent infection with Toxoplasma gondii is common in humans (approximately 30% of the global population) and is a significant risk factor for schizophrenia. Since prevalence of T. gondii infection is far greater than prevalence of schizophrenia (0.5-1%), genetic risk factors are likely also necessary to contribute to schizophrenia. To test this concept in an animal model, Nurr1-null heterozygous (+/-) mice and wild-type (+/+) mice were evaluate using an emergence test, activity in an open field and with a novel object, response to bobcat urine and prepulse inhibition of the acoustic startle response (PPI) prior to and 6 weeks after infection with T. gondii. In the emergence test, T. gondii infection significantly decreased the amount of time spent in the cylinder. Toxoplasma gondii infection significantly elevated open field activity in both +/+ and +/- mice but this increase was significantly exacerbated in +/- mice. T. gondii infection reduced PPI in male +/- mice but this was not statistically significant. Aversion to bobcat urine was abolished by T. gondii infection in +/+ mice. In female +/- mice, aversion to bobcat urine remained after T. gondii infection while the male +/- mice showed no aversion to bobcat urine. Antibody titers of infected mice were a critical variable associated with changes in open field activity, such that an inverted U shaped relationship existed between antibody titers and the percent change in open field activity with a significant increase in activity at low and medium antibody titers but no effect at high antibody titers. These data demonstrate that the Nurr1 +/- genotype predisposes mice to T. gondii-induced alterations in behaviors that involve dopamine neurotransmission and are associated with symptoms of schizophrenia. We propose that these alterations in murine behavior were due to further exacerbation of the altered dopamine neurotransmission in Nurr1 +/- mice.

Assessing anxiety in C57BL/6J mice: a pharmacological characterization of the open-field and light/dark tests.

PubMed

Heredia, Luis; Torrente, Margarita; Colomina, María T; Domingo, José L

2014-01-01

In order to assess anxiety in mammals various tests and species are currently available. These current assays measure changes in anxiety-like behaviors. The open-field and the light/dark are anxiety tests based on the spontaneous behavior of the animals, with C57BL/6J mice being a frequently used strain in behavioral studies. However, the suitability of this strain as a choice in anxiety studies has been questioned. In this study, we performed two pharmacological characterizations of this strain in both the open-field and the light/dark tests. We examined the changes in the anxiety-like behaviors of C57BL/6J mice exposed to chlordiazepoxide (CDP), an anxiolytic drug, at doses of 5 and 10 mg/kg, picrotoxine (PTX), an anxiogenic drug, at doses of 0.5 and 1 mg/kg, and methylphenidate (MPH), a psychomotor stimulant drug, at doses of 5 and 10 mg/kg, in a first experiment. In a second experiment, we tested CDP at 2.5 mg/kg, PTX at 2 mg/kg and MPH at 2.5 mg/kg. Results showed an absence of anxiolytic-like effects of CDP in open-field and light/dark tests. Light/dark test was more sensitive to the anxiogenic effects of PTX than the open-field test. Finally, a clear anxiogenic effect of MPH was observed in the two tests. Although C57BL/6J mice could not be a sensitive model to study anxiolytic effects in pharmacological or behavioral interventions, it might be a suitable model to test anxiogenic effects. Further studies are necessary to corroborate these results. Copyright © 2013 Elsevier Inc. All rights reserved.

Hyperactive behaviour in the mouse model of mucopolysaccharidosis IIIB in the open field and home cage environments.

PubMed

Langford-Smith, A; Malinowska, M; Langford-Smith, K J; Wegrzyn, G; Jones, S; Wynn, R; Wraith, J E; Wilkinson, F L; Bigger, B W

2011-08-01

Mucopolysaccharidosis IIIB (MPS IIIB) is a lysosomal storage disorder characterized by severe behavioural disturbances and progressive loss of cognitive and motor function. There is no effective treatment, but behavioural testing is a valuable tool to assess neurodegeneration and the effect of novel therapies in mouse models of disease. Several groups have evaluated behaviour in this model, but the data are inconsistent, often conflicting with patient natural history. We hypothesize that this discrepancy could be due to differences in open field habituation and home cage behaviour. Eight-month-old wild-type and MPS IIIB mice were tested in a 1-h open field test, performed 1.5 h after lights on, and a 24-h home cage behaviour test performed after 24 h of acclimatization. In the 1-h test, MPS IIIB mice were hyperactive, with increased rapid exploratory behaviour and reduced immobility time. No differences in anxiety were seen. Over the course of the test, differences became more pronounced with maximal effects at 1 h. The 24-hour home cage test was less reliable. There was evidence of increased hyperactivity in MPS IIIB mice, however, immobility was also increased, suggesting a level of inconsistency in this test. Performance of open field analysis within 1-2 h after lights on is probably critical to achieving maximal success as MPS IIIB mice have a peak in activity around this time. The open field test effectively identifies hyperactive behaviour in MPS IIIB mice and is a significant tool for evaluating effects of therapy on neurodegeneration. © 2011 The Authors. Genes, Brain and Behavior © 2011 Blackwell Publishing Ltd and International Behavioural and Neural Genetics Society.

Color-magnitude Diagrams for the Stellar Open Cluster M 67 in theVilnius Photometric System

NASA Astrophysics Data System (ADS)

Boyle, Richard P.; Janusz, Robert

2015-01-01

Stellar photometry in the Vilnius Photometric System requires one percent quality for deriving luminosity class and spectral type subclass. We use such existing photometry of the open cluster M 67 to calibrate new CCD observations at the Vatican Advanced Technology Telescope (VATT) for correcting the flat-fielding zero-point and deriving the color-transformation in this intermediate-band, seven filter system (Boyle et al., BAAS 37 #4, 2005).Recently we have developed a "tie-in" observational practice to apply the zero-point and color transformation of the M 67 observations to neighboring starfields of interest that have no existing photometry. Sky transparency must remain constant to better than one percent during a round of short exposures in a filter between the field having calibrated photometry and the new field having no photometry as if the new field was exposed simultaneously with the master field.Proof of success for this "tie-in" method is shown with the master field being M 67 and the "tie-in" field being the nearby extended "corona" area. The distinctive color-magnitude diagrams of the old open clusterM 67 reveal the sensitivity to having constant sky transparency during the round of short exposures on M 67 and its extended area. For the extended area has the same form in its color-magnitude diagram as M 67. So variation in sky transparency shows displacement on the color-magnitude diagrams at the one percent quality.We will attempt new analysis concerning evolution of this very old open cluster (2.56 Gyr, WEBDA, http://www.univie.ac.at/webda/) and the surrounding "coronal" extent with reference to previous work by Chupina and Vereshchagin (Astron. Astrophys, 334, 552, 1998).

Electric Field Observations of Plasma Convection, Shear, Alfven Waves, and other Phenomena Observed on Sounding Rockets in the Cusp and Boundary Layer

NASA Technical Reports Server (NTRS)

Pfaff, R. F.

2009-01-01

On December 14,2002, a NASA Black Brant X sounding rocket was launched equatorward from Ny Alesund, Spitzbergen (79 N) into the dayside cusp and subsequently cut across the open/closed field line boundary, reaching an apogee of771 km. The launch occurred during Bz negative conditions with strong By negative that was changing during the flight. SuperDarn (CUTLASS) radar and subsequent model patterns reveal a strong westward/poleward convection, indicating that the rocket traversed a rotational reversal in the afternoon merging cell. The payload returned DC electric and magnetic fields, plasma waves, energetic particle, suprathermal electron and ion, and thermal plasma data. We provide an overview of the main observations and focus on the DC electric field results, comparing the measured E x B plasma drifts in detail with the CUTLASS radar observations of plasma drifts gathered simultaneously in the same volume. The in situ DC electric fields reveal steady poleward flows within the cusp with strong shears at the interface of the closed/open field lines and within the boundary layer. We use the observations to discuss ionospheric signatures of the open/closed character of the cusp/low latitude boundary layer as a function of the IMF. The electric field and plasma density data also reveal the presence of very strong plasma irregularities with a large range of scales (10 m to 10 km) that exist within the open field line cusp region yet disappear when the payload was equatorward of the cusp on closed field lines. These intense low frequency wave observations are consistent with strong scintillations observed on the ground at Ny Alesund during the flight. We present detailed wave characteristics and discuss them in terms of Alfven waves and static irregularities that pervade the cusp region at all altitudes.

Open Space Communities

Treesearch

Rachel Kaplan; Maureen E. Austin; Stephen Kaplan; Stephen Kaplan

2004-01-01

Though the concept is often left undefined, "open space" in residential areas is generally viewed as an asset. Duany et al. (2000), for example, suggest that "the generous provision of open space" offers the "main advantage" of suburbs over the city (p. 31). With forest, field, and farm steadily giving way to development, many communities...

Open Access, Education Research, and Discovery

ERIC Educational Resources Information Center

Furlough, Michael

2010-01-01

Background/Context: The open access movement has successfully drawn attention to economic and political aspects of scholarly communication through a significant body of commentary that debates the merits of open access and the potential damage it may do to scholarly publishing. Researchers within the field of education research, notably John…

Magnetic field tuning of an excitonic insulator between the weak and strong coupling regimes in quantum limit graphite [Tunable excitonic insulator in quantum limit graphite

DOE PAGES

Zhu, Zengwei; McDonald, R. D.; Shekhter, A.; ...

2017-05-04

Here, the excitonic insulator phase has long been predicted to form in proximity to a band gap opening in the underlying band structure. The character of the pairing is conjectured to crossover from weak (BCS-like) to strong coupling (BEC-like) as the underlying band structure is tuned from the metallic to the insulating side of the gap opening. Here we report the high-magnetic field phase diagram of graphite to exhibit just such a crossover. By way of comprehensive angle-resolved magnetoresistance measurements, we demonstrate that the underlying band gap opening occurs inside the magnetic field-induced phase, paving the way for a systematicmore » study of the BCS-BEC-like crossover by means of conventional condensed matter probes.« less

Effects of early environmental enrichment upon open-field behavior and timidity in the domestic chick.

PubMed

Jones, R B

1982-03-01

Early environmental enrichment was evaluated by its effect on the behavior of 7-day-old male and female domestic chicks in an open field or novel environment and in a hole-in-the-wall test of timidity. The chicks were housed in same-sex groups of 10. The bare environments contained wood litter, food, and water, whereas the enriched boxes also contained various objects. In the open field, immobility was lower while feeding, walking, jumping and vocalization were higher in the enriched birds than in those reared in the bare environment. Enrichment also decreased emergence latencies in the hole-in-the-wall box. The increased stimulation provided by environmental enrichment may decrease fearfulness in subsequent fear-inducing situations and may enhance the ability of animals to adapt to novelty.

Naloxone effects on behavior of inbred mice with different response to emotional stress in open field test.

PubMed

Nadorova, A V; Kozlovskaja, M M; Seredenin, S B

2009-10-01

Effects of nonspecific opiate receptor antagonist naloxone in doses of 0.1, 0.5, 1.0, 5.0, 10.0 mg/kg on open field behavior and spontaneous motor activity were studied in male BALB/c and C57Bl/6 mice. Differently directed effects of naloxone on behavioral parameters of emotional-stress reaction in BALB/c and C57Bl/6 mice were observed. Naloxone increased motor activity in the open field test in BALB/c mice, but decreased it in C57Bl/6 mice. In the absence of stress, naloxone in the studied dose range did not affect spontaneous motor activity in C57Bl/6 mice, and significantly reduced activity in BALB/c mice in doses 0.5 and 1.0 mg/kg.

Magnetic field tuning of an excitonic insulator between the weak and strong coupling regimes in quantum limit graphite [Tunable excitonic insulator in quantum limit graphite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Zengwei; McDonald, R. D.; Shekhter, A.

Here, the excitonic insulator phase has long been predicted to form in proximity to a band gap opening in the underlying band structure. The character of the pairing is conjectured to crossover from weak (BCS-like) to strong coupling (BEC-like) as the underlying band structure is tuned from the metallic to the insulating side of the gap opening. Here we report the high-magnetic field phase diagram of graphite to exhibit just such a crossover. By way of comprehensive angle-resolved magnetoresistance measurements, we demonstrate that the underlying band gap opening occurs inside the magnetic field-induced phase, paving the way for a systematicmore » study of the BCS-BEC-like crossover by means of conventional condensed matter probes.« less

Formation of the Sun-aligned arc region and the void (polar slot) under the null-separator structure

NASA Astrophysics Data System (ADS)

Tanaka, T.; Obara, T.; Watanabe, M.; Fujita, S.; Ebihara, Y.; Kataoka, R.

2017-04-01

From the global magnetosphere-ionosphere coupling simulation, we examined the formation of the Sun-aligned arc region and the void (polar slot) under the northward interplanetary magnetic field (IMF) with negative By condition. In the magnetospheric null-separator structure, the separatrices generated from two null points and two separators divide the entire space into four types of magnetic region, i.e., the IMF, the northern open magnetic field, the southern open magnetic field, and the closed magnetic field. In the ionosphere, the Sun-aligned arc region and the void are reproduced in the distributions of simulated plasma pressure and field-aligned current. The outermost closed magnetic field lines on the boundary (separatrix) between the northern open magnetic field and the closed magnetic field are projected to the northern ionosphere at the boundary between the Sun-aligned arc region and the void, both on the morning and evening sides. The magnetic field lines at the plasma sheet inner edge are projected to the equatorward boundary of the oval. Therefore, the Sun-aligned arc region is on the closed magnetic field lines of the plasma sheet. In the plasma sheet, an inflated structure (bulge) is generated at the junction of the tilted plasma sheet in the far-to-middle tail and nontilted plasma sheet in the ring current region. In the Northern Hemisphere, the bulge is on the evening side wrapped by the outermost closed magnetic field lines that are connected to the northern evening ionosphere. This inflated structure (bulge) is associated with shear flows that cause the Sun-aligned arc.

Evolution of Large-Scale Magnetic Fields and State Transitions in Black Hole X-Ray Binaries

NASA Astrophysics Data System (ADS)

Wang, Ding-Xiong; Huang, Chang-Yin; Wang, Jiu-Zhou

2010-04-01

The state transitions of black hole (BH) X-ray binaries are discussed based on the evolution of large-scale magnetic fields, in which the combination of three energy mechanisms are involved: (1) the Blandford-Znajek (BZ) process related to the open field lines connecting a rotating BH with remote astrophysical loads, (2) the magnetic coupling (MC) process related to the closed field lines connecting the BH with its surrounding accretion disk, and (3) the Blandford-Payne (BP) process related to the open field lines connecting the disk with remote astrophysical loads. It turns out that each spectral state of the BH binaries corresponds to each configuration of magnetic field in BH magnetosphere, and the main characteristics of low/hard (LH) state, hard intermediate (HIM) state and steep power law (SPL) state are roughly fitted based on the evolution of large-scale magnetic fields associated with disk accretion.

[Measurements of the flux densities of static magnetic fields generated by two types of dental magnetic attachments and their retentive forces].

PubMed

Xu, Chun; Chao, Yong-lie; Du, Li; Yang, Ling

2004-05-01

To measure and analyze the flux densities of static magnetic fields generated by two types of commonly used dental magnetic attachments and their retentive forces, and to provide guidance for the clinical application of magnetic attachments. A digital Gaussmeter was used to measure the flux densities of static magnetic fields generated by two types of magnetic attachments, under four circumstances: open-field circuit; closed-field circuit; keeper and magnet slid laterally for a certain distance; and existence of air gap between keeper and magnet. The retentive forces of the magnetic attachments in standard closed-field circuit, with the keeper and magnet sliding laterally for a certain distance or with a certain air gap between keeper and magnet were measured by a tensile testing machine. There were flux leakages under both the open-field circuit and closed-field circuit of the two types of magnetic attachments. The flux densities on the surfaces of MAGNEDISC 800 (MD800) and MAGFIT EX600W (EX600) magnetic attachments under open-field circuit were 275.0 mT and 147.0 mT respectively. The flux leakages under closed-field circuit were smaller than those under open-field circuit. The respective flux densities on the surfaces of MD800 and EX600 magnetic attachments decreased to 11.4 mT and 4.5 mT under closed-field circuit. The flux density around the magnetic attachment decreased as the distance from the surface of the attachment increased. When keeper and magnet slid laterally for a certain distance or when air gap existed between keeper and magnet, the flux leakage increased in comparison with that under closed-field circuit. Under the standard closed-field circuit, the two types of magnetic attachments achieved the largest retentive forces. The retentive forces of MD800 and EX600 magnetic attachments under the standard closed-field circuit were 6.20 N and 4.80 N respectively. The retentive forces decreased with the sliding distance or with the increase of air gap between keeper and magnet. The magnetic attachments have flux leakages. When they are used in patients' oral cavities, if keeper and magnet are not attached accurately, the flux leakage will increase, and at the same time the retentive force will decrease. Therefore the keeper and magnet should be attached accurately in clinical application.

Progressive Decrease of Peripapillary Angioflow Vessel Density During Structural and Visual Field Progression in Early Primary Open-angle Glaucoma.

PubMed

Holló, Gábor

2017-07-01

To present a case of early primary open-angle glaucoma in which retinal nerve fiber layer thickness (RNFLT), ganglion cell complex (GCC), and visual field progression were accompanied with significant progression of peripapillary angioflow vessel density (PAFD) measured with optical coherence tomographic angiography. A 68-year-old female patient who was under topical intraocular pressure (IOP) lowering medication for 20 years for ocular hypertension of the right and preperimetric primary open-angle glaucoma of the left eye (with reproducible inferotemporal and superotemporal neuroretinal rim and RNFL loss) was prospectively imaged with the AngioVue OCT for RNFLT, GCC thickness, and PAFD, and investigated with the Octopus Normal G2 visual field test on the same days at 6-month intervals for 18 months, while the IOP of the left eye escaped from control. IOP of the left eye fluctuated between 14 and 30 mm Hg in the study period. RNFLT, GCC thickness, and peripapillary PAFD all decreased significantly (linear regression analysis, P=0.030, 0.040, and 0.020, respectively), and a significant 2.1 dB/y progression was seen for a superior visual field cluster. The RNFLT, peripapillary PAFD, and visual field of the right eye remained normal and unchanged. In our case IOP elevation, glaucomatous visual field conversion, and structural progression were accompanied with significant progressive decrease of peripapillary PAFD. The simultaneous thinning of RNFLT and GCC and decrease of peripapillary PAFD suggest that PAFD may potentially be an additional indicator of early progression in primary open-angle glaucoma.

Observations of two-dimensional magnetic field evolution in a plasma opening switch

NASA Astrophysics Data System (ADS)

Shpitalnik, R.; Weingarten, A.; Gomberoff, K.; Krasik, Ya.; Maron, Y.

1998-03-01

The time dependent magnetic field distribution was studied in a coaxial 100-ns positive-polarity Plasma Opening Switch (POS) by observing the Zeeman effect in ionic line emission. Measurements local in three dimensions are obtained by doping the plasma using laser evaporation techniques. Fast magnetic field penetration with a relatively sharp magnetic field front (⩽1 cm) is observed at the early stages of the pulse (t≲25). Later in the pulse, the magnetic field is observed at the load-side edge of the plasma, leaving "islands" of low magnetic field at the plasma center that last for about 10 ns. The two-dimensional (2-D) structure of the magnetic field in the r,z plane is compared to the results of an analytical model based on electron-magneto-hydrodynamics, that utilizes the measured 2-D plasma density distribution and assumes fast magnetic field penetration along both POS electrodes. The model results provide quantitative explanation for the magnetic field evolution observed.

Further Development of HS Field Theory

NASA Astrophysics Data System (ADS)

Abdurrahman, Abdulmajeed; Faridani, Jacqueline; Gassem, Mahmoud

2006-04-01

We present a systematic treatment of the HS Field theory of the open bosonic string and discuss its relationship to other full string field theories of the open bosonic string such as Witten's theory and the CVS theory. In the development of the HS field theory we encounter infinite dimensional matrices arising from the change of representation between the two theories, i.e., the HS field theory and the full string field theory. We give a general procedure of how to invert these gigantic matrices. The inversion of these matrices involves the computation of many infinite sums. We give the values of these sums and state their generalizations arising from considering higher order vertices (i.e., more than three strings) in string field theory. Moreover, we give a general procedure, on how to evaluate the generalized sums, that can be extended to many generic sums of similar properties. We also discuss the conformal operator connecting the HS field theory to that of the CVS string field theory.

Energetic electron anisotropies in the magnetotail - Identification of open and closed field lines

NASA Technical Reports Server (NTRS)

Baker, D. N.; Stone, E. C.

1976-01-01

Unidirectional anisotropies in the energetic electron fluxes (E greater than or equal to about 200 keV) have been observed in the earth's magnetotail with the Caltech Electron/Isotope Spectrometer on IMP-8. The anisotropies occur during periods of enhanced fluxes and provide essential information on the topology (open or closed) of the magnetotail field lines which are associated with recently identified acceleration regions.

Solar UVB response of bioactives in strawberry (Fragaria × ananassa Duch. L.): a comparison of protected and open-field cultivation.

PubMed

Josuttis, Melanie; Dietrich, Helmut; Treutter, Dieter; Will, Frank; Linnemannstöns, Ludger; Krüger, Erika

2010-12-22

Strawberries (Fragaria × ananassa Duch. cvs. Everest, Elsanta) were grown in a tunnel covered with two films, which were distinguished in their ultraviolet transparency, as well as under open-field conditions. One applied film was not transparent for UVB radiation, and the second film transmitted 70% of UVB radiation. During the present study, the nutritional value and quality parameters of the fruits were evaluated. Strawberries were UV-unresponsive in view of the content of ascorbic acid and sum parameters like total anthocyanins and antioxidant capacity measured with TEAC (trolox equivalent antioxidant capacity), ORAC (oxygen radical absorbance capacity) and total phenols. These parameters were mainly affected by sampling date and cultivar. However, HPLC analysis showed that individual phenolics were affected in the absence of UV radiation. The content of the anthocyanin cyanidin 3-glucoside and the flavonols quercetin 3-glucuronide and kaempferol 3-glucoside was decreased in the fruits grown under UV blocking film compared to open-field grown strawberries. By means of the UV transparent film the content of the mentioned flavonoids could be enhanced up to similar amounts like in open-field grown strawberries. All other phenolics were not consistently affected by UV radiation. This result was independent of cultivar.