Quasi-phases and pseudo-transitions in one-dimensional models with nearest neighbor interactions
de Souza, S. M.; Rojas, Onofre
2018-01-01
There are some particular one-dimensional models, such as the Ising-Heisenberg spin models with a variety of chain structures, which exhibit unexpected behaviors quite similar to the first and second order phase transition, which could be confused naively with an authentic phase transition. Through the analysis of the first derivative of free energy, such as entropy, magnetization, and internal energy, a "sudden" jump that closely resembles a first-order phase transition at finite temperature occurs. However, by analyzing the second derivative of free energy, such as specific heat and magnetic susceptibility at finite temperature, it behaves quite similarly to a second-order phase transition exhibiting an astonishingly sharp and fine peak. The correlation length also confirms the evidence of this pseudo-transition temperature, where a sharp peak occurs at the pseudo-critical temperature. We also present the necessary conditions for the emergence of these quasi-phases and pseudo-transitions.
Pseudo-One-Dimensional Magnonic Crystals for High-Frequency Nanoscale Devices
Banerjee, Chandrima; Choudhury, Samiran; Sinha, Jaivardhan; Barman, Anjan
2017-07-01
The synthetic magnonic crystals (i.e., periodic composites consisting of different magnetic materials) form one fascinating class of emerging research field, which aims to command the process and flow of information by means of spin waves, such as in magnonic waveguides. One of the intriguing features of magnonic crystals is the presence and tunability of band gaps in the spin-wave spectrum, where the high attenuation of the frequency bands can be utilized for frequency-dependent control on the spin waves. However, to find a feasible way of band tuning in terms of a realistic integrated device is still a challenge. Here, we introduce an array of asymmetric saw-tooth-shaped width-modulated nanoscale ferromagnetic waveguides forming a pseudo-one-dimensional magnonic crystal. The frequency dispersion of collective modes measured by the Brillouin light-scattering technique is compared with the band diagram obtained by numerically solving the eigenvalue problem derived from the linearized Landau-Lifshitz magnetic torque equation. We find that the magnonic band-gap width, position, and the slope of dispersion curves are controllable by changing the angle between the spin-wave propagation channel and the magnetic field. The calculated profiles of the dynamic magnetization reveal that the corrugation at the lateral boundary of the waveguide effectively engineers the edge modes, which forms the basis of the interactive control in magnonic circuits. The results represent a prospective direction towards managing the internal field distribution as well as the dispersion properties, which find potential applications in dynamic spin-wave filters and magnonic waveguides in the gigahertz frequency range.
Analysis of spectral operators in one-dimensional domains
Maday, Y.
1985-01-01
Results are proven concerning certain projection operators on the space of all polynomials of degree less than or equal to N with respect to a class of one-dimensional weighted Sobolev spaces. The results are useful in the theory of the approximation of partial differential equations with spectral methods.
Connectivity analysis of one-dimensional ad-hoc networks
DEFF Research Database (Denmark)
Bøgsted, Martin; Rasmussen, Jakob Gulddahl; Schwefel, Hans Peter
2011-01-01
and moments of these random variables for general stationary MAP processes on a one dimensional space. The numerical results compare bursty vehicular traffic with independent movement scenarios described by a Poisson process, illustrate in examples the impact of a random communication range, and demonstrate...
Analysis of spectral projectors in one-dimensional domains
Maday, Y.
1990-01-01
A class of projection operators with values in a subspace of polynomials is analyzed. These projection operators are related to the Hilbert spaces involved in the numerical analysis of spectral methods. They are, in the first part of the paper, the standard Sobolev spaces and, in the second part, some weighted Sobolev spaces, the weight of which is related to the orthoronality relation satisfied by the Chebyshev polynomials. These results are used to study the approximation of a model fourth-order problem.
Lempel-Ziv complexity analysis of one dimensional cellular automata.
Estevez-Rams, E; Lora-Serrano, R; Nunes, C A J; Aragón-Fernández, B
2015-12-01
Lempel-Ziv complexity measure has been used to estimate the entropy density of a string. It is defined as the number of factors in a production factorization of a string. In this contribution, we show that its use can be extended, by using the normalized information distance, to study the spatiotemporal evolution of random initial configurations under cellular automata rules. In particular, the transfer information from time consecutive configurations is studied, as well as the sensitivity to perturbed initial conditions. The behavior of the cellular automata rules can be grouped in different classes, but no single grouping captures the whole nature of the involved rules. The analysis carried out is particularly appropriate for studying the computational processing capabilities of cellular automata rules.
1DB, a one-dimensional diffusion code for nuclear reactor analysis
Energy Technology Data Exchange (ETDEWEB)
Little, W.W. Jr. (Pacific Northwest Lab., Richland, WA (United States))
1991-09-01
1DB is a multipurpose, one-dimensional (plane, cylinder, sphere) diffusion theory code for use in reactor analysis. The code is designed to do the following: To compute k{sub eff} and perform criticality searches on time absorption, reactor composition, reactor dimensions, and buckling by means of either a flux or an adjoint model; to compute collapsed microscopic and macroscopic cross sections averaged over the spectrum in any specified zone; to compute resonance-shielded cross sections using data in the shielding factor format; and to compute isotopic burnup using decay chains specified by the user. All programming is in FORTRAN. Because variable dimensioning is employed, no simple restrictions on problem complexity can be stated. The number of spatial mesh points, energy groups, upscattering terms, etc. is limited only by the available memory. The source file contains about 3000 cards. 4 refs.
Pataky, Todd C; Vanrenterghem, Jos; Robinson, Mark A
2015-05-01
Biomechanical processes are often manifested as one-dimensional (1D) trajectories. It has been shown that 1D confidence intervals (CIs) are biased when based on 0D statistical procedures, and the non-parametric 1D bootstrap CI has emerged in the Biomechanics literature as a viable solution. The primary purpose of this paper was to clarify that, for 1D biomechanics datasets, the distinction between 0D and 1D methods is much more important than the distinction between parametric and non-parametric procedures. A secondary purpose was to demonstrate that a parametric equivalent to the 1D bootstrap exists in the form of a random field theory (RFT) correction for multiple comparisons. To emphasize these points we analyzed six datasets consisting of force and kinematic trajectories in one-sample, paired, two-sample and regression designs. Results showed, first, that the 1D bootstrap and other 1D non-parametric CIs were qualitatively identical to RFT CIs, and all were very different from 0D CIs. Second, 1D parametric and 1D non-parametric hypothesis testing results were qualitatively identical for all six datasets. Last, we highlight the limitations of 1D CIs by demonstrating that they are complex, design-dependent, and thus non-generalizable. These results suggest that (i) analyses of 1D data based on 0D models of randomness are generally biased unless one explicitly identifies 0D variables before the experiment, and (ii) parametric and non-parametric 1D hypothesis testing provide an unambiguous framework for analysis when one׳s hypothesis explicitly or implicitly pertains to whole 1D trajectories. Copyright © 2015 Elsevier Ltd. All rights reserved.
Nonstandard Analysis and Shock Wave Jump Conditions in a One-Dimensional Compressible Gas
Energy Technology Data Exchange (ETDEWEB)
Roy S. Baty, F. Farassat, John A. Hargreaves
2007-05-25
Nonstandard analysis is a relatively new area of mathematics in which infinitesimal numbers can be defined and manipulated rigorously like real numbers. This report presents a fairly comprehensive tutorial on nonstandard analysis for physicists and engineers with many examples applicable to generalized functions. To demonstrate the power of the subject, the problem of shock wave jump conditions is studied for a one-dimensional compressible gas. It is assumed that the shock thickness occurs on an infinitesimal interval and the jump functions in the thermodynamic and fluid dynamic parameters occur smoothly across this interval. To use conservations laws, smooth pre-distributions of the Dirac delta measure are applied whose supports are contained within the shock thickness. Furthermore, smooth pre-distributions of the Heaviside function are applied which vary from zero to one across the shock wave. It is shown that if the equations of motion are expressed in nonconservative form then the relationships between the jump functions for the flow parameters may be found unambiguously. The analysis yields the classical Rankine-Hugoniot jump conditions for an inviscid shock wave. Moreover, non-monotonic entropy jump conditions are obtained for both inviscid and viscous flows. The report shows that products of generalized functions may be defined consistently using nonstandard analysis; however, physically meaningful products of generalized functions must be determined from the physics of the problem and not the mathematical form of the governing equations.
Pittman, C. M.
1994-01-01
This program performs a one-dimensional numerical analysis of the transient thermal response of multi-layer insulative systems. The analysis can determine the temperature distribution through a system consisting of from one to four layers, one of which can be an air gap. Concentrated heat sinks at any interface can be included. The computer program based on the analysis will determine the thickness of a specified layer that will satisfy a temperature limit criterion at any point in the insulative system. The program will also automatically calculate the thickness at several points on a system and determine the total system mass. This program was developed as a tool for designing thermal protection systems for high-speed aerospace vehicles but could be adapted to many areas of industry involved in thermal insulation systems. In this package, the equations describing the transient thermal response of a system are developed. The governing differential equation for each layer and boundary condition are put in finite-difference form using a Taylor's series expansion. These equations yield an essentially tridiagonal matrix of unknown temperatures. A procedure based on Gauss' elimination method is used to solve the matrix. This program is written in FORTRAN IV for the CDC RUN compiler and has been implemented on a CDC 6000 series machine operating under SCOPE 3.0. This program requires a minimum of 44K (octal) of 60 bit words of memory.
Analysis of cutoff frequency in one dimensional ternary superconducting photonic crystal
K. P., Sreejith; Maria D'souza, Nirmala; Mathew, Vincent
2017-09-01
By means of two fluid model and transfer matrix method, we have theoretically investigated the transmittance property of a one dimensional ternary photonic crystal consist of a pair of superconducting materials and a dielectric in the infrared frequency region. We mainly focus on the analysis of cutoff frequency since the calculations can be useful in the fabrication of optical devices such as reflector, high pass filter etc. The study reveals that the cutoff frequency is sensitive to thickness of superconducting materials, dielectric layer thickness, operating temperature and refractive index of intermediate dielectric. Cutoff frequency shifted to higher frequency region on increasing number of periods and superconductor layer thickness where as it reduces on increasing dielectric thickness, operating temperature and refractive index of intermediate dielectric. Furthermore, we compared the cutoff frequency of three different 1D ternary photonic crystals comprising of a dielectric and a pair of high-high, high-low and low-low temperature superconducting materials. Our comparison results shows that the cutoff frequency can be effectively modified with different combination of superconducting materials.
Influence of a discontinuity on the spectral and fractal analysis of one-dimensional data
Directory of Open Access Journals (Sweden)
R. P. H. Berton
2004-01-01
Full Text Available The analysis of a data area or segment containing steep transitions between regions with different textures (for example a cloud and its background leads to addressing the problem of discontinuities and their impact on texture analysis. In that purpose, an original one-dimensional analytical model of spectrum and roughness function has been worked out, with a discontinuity between two fractal regions, each one specified by its average µ, standard deviation σ, spectral index β and Hurst exponent H. This has the advantage of not needing the generation of a fractal structure with a particular algorithm or random functions and clearly puts into evidence the role played by the average in generating spectral poles and side lobes. After validation of the model calibration, a parametric study is carried out in order to understand the influence of this discontinuity on the estimation of the spectral index β and the Hurst parameter H. It shows that for a pure µ-gap, H is well estimated everywhere, though overestimated, and β is overestimated in the anti-correlation range and saturates in the correlation range. For a pure σ-gap the retrieval of H is excellent everywhere and the behaviour of β is better than for a µ-gap, leading to less overestimation in the anti-correlation range. For a pure β-gap, saturation degrades measurements in the case of raw data and the medium with smaller spectral index is predominant in the case of trend-corrected data. For a pure H-gap, there is also dominance of the medium with smaller fractal exponent.
Jung, Joon Hee; Jang, Gang-Won; Shin, Dongil; Kim, Yoon Young
2017-08-01
This paper presents a method to analyze thin-walled beams with quadrilateral cross sections reinforced with diaphragms using a one-dimensional higher-order beam theory. The effect of a diaphragm is reflected focusing on the increase of static stiffness. The deformations on the beam-interfacing boundary of a thin diaphragm are described by using deformation modes of the beam cross section while the deformations inside the diaphragm are approximated in the form of complete cubic polynomials. By using the principle of minimum potential energy, its stiffness that significantly affects distortional deformation of a thin-walled beam can be considered in the one-dimensional beam analysis. It is shown that the accuracy of the resulting one-dimensional analysis is comparable with that by a shell element based analysis. As a means to demonstrate the usefulness of the present approach for design, position optimization problems of diaphragms for stiffness reinforcement of an automotive side frame are solved.
Shamsaei, Ezzatollah; Lin, Xiaocheng; Wan, Li; Tong, Yuping; Wang, Huanting
2016-12-11
A new pseudo-seeding and nano-scaffolding method was developed to synthesize thin ZIF-8 hybrid membranes (100-200 nm) with remarkable mechanical and structural stability and high H 2 permeance (2.87 × 10 -5 mol m -2 s -1 Pa -1 ) and selectivity over CO 2 (14), N 2 (18), CH 4 (35), C 3 H 6 (52.4) and C 3 H 8 (950.1).
Classical Lie Point Symmetry Analysis of a Steady Nonlinear One-Dimensional Fin Problem
Directory of Open Access Journals (Sweden)
R. J. Moitsheki
2012-01-01
Full Text Available We consider the one-dimensional steady fin problem with the Dirichlet boundary condition at one end and the Neumann boundary condition at the other. Both the thermal conductivity and the heat transfer coefficient are given as arbitrary functions of temperature. We perform preliminary group classification to determine forms of the arbitrary functions appearing in the considered equation for which the principal Lie algebra is extended. Some invariant solutions are constructed. The effects of thermogeometric fin parameter and the exponent on temperature are studied. Also, the fin efficiency is analyzed.
Characteristics analysis of the one-dimensional pulsating dynamics of chain-branching detonations
Leung, C.; Radulescu, M. I.; Sharpe, G. J.
2010-12-01
The nonlinear pulsating mechanism of one-dimensional detonations was studied numerically using a simple two-step chain-branching model with separate induction and reaction zones. Numerical simulations were performed for a wide range of parameters, which revealed four distinct pulsating regimes classified according to the mechanism controlling the frequency of the pulsations. The dynamics of these regimes were clarified by reconstructing the characteristics, representing the trajectory of pressure waves and particle paths. The high and low frequency regimes of oscillation previously observed in one-step and realistic chemistry simulations were clarified. Under some parameter range, simultaneous low and high frequency pulsations were observed. A novel regime was also found with a pulsation period smaller than the induction time. It involves coupling between the acoustic and the reactivity disturbances propagating, respectively, along the C- and C0 characteristics. These are generated at successive lead shock pulsations and arrive at the reaction zone simultaneously. For all regimes, the dominating mechanism of the pulsating instability was found to be in good qualitative agreement with Toong's phenomenological model based on the wave dynamics in a square wave reaction zone structure.
Analysis of polarized pulse propagation through one-dimensional scattering medium
Zhang, Yong; Yao, Feng-Ju; Xie, Ming; Yi, Hong-Liang
2017-08-01
This paper analyzes the polarized light propagation in a one-dimensional scattering medium with the upper surface subjected to an oblique incident short-pulsed laser beam using the natural element method (NEM). The NEM discretization scheme for the transient vector radiative transfer equation (TVRTE) is presented in detail. The accuracy of the natural element method for transient vector radiative transfer in the scattering medium is assessed. Numerical results show that the NEM is accurate, and effective in solving transient polarized radiative problems. We examine a square short-pulsed laser transport firstly in the atmosphere with Mie scattering and then within aerosol scattering medium. We then investigate the transient polarized radiative transfer problem in the atmosphere-ocean system. The time-resolved signals and the polarization state of the Stokes vector are presented and analyzed. It is found that the scattering types of the medium make greatly influence on the transient transportation of the polarized light. Critically, the polarization states of the backward and forward scattered photons show significantly different time varying trends. For the two-layer system with dissimilar refractive index distributions, due to the total-reflection effect, the existence of a Fresnel interface significantly changes the polarization state of the light, and discontinuous distribution features are observed on the interface.
Analysis of cutoff frequency in a one-dimensional superconductor-metamaterial photonic crystal
Energy Technology Data Exchange (ETDEWEB)
Aly, Arafa H, E-mail: arafa16@yahoo.com [Department of Physics, Faculty of Sciences, Beni-Suef University (Egypt); Aghajamali, Alireza [Department of Physics, Marvdasht Branch, Islamic Azad University, Marvdasht (Iran, Islamic Republic of); Elsayed, Hussein A.; Mobarak, Mohamed [Department of Physics, Faculty of Sciences, Beni-Suef University (Egypt)
2016-09-15
Highlights: • Our results show that the appearance of the cutoff frequency, below which the incident electromagnetic waves cannot propagate in the structure. We demonstrate that the cutoff frequency shows an upward trend as the thickness of the superconductor layer as well as the thickness of the metamaterial increase. • The cutoff frequency can be tuned by the operating temperature. Our structures are good candidates for many optical devices such as optical filters, switches, temperature controlled optical shutter, and among photoelectronic applications in gigahertz. - Abstract: In this paper, using the two-fluid model and the characteristic matrix method, we investigate the transmission characteristics of the one-dimensional photonic crystal. Our structure composed of the layers of low-temperature superconductor material (NbN) and double-negative metamaterial. We target studying the effect of many parameters such as the thickness of the superconductor material, the thickness of the metamaterial layer, and the operating temperature. We show that the cut-off frequency can be tuned efficiently by the operating temperature as well as the thicknesses of the constituent materials.
DEFF Research Database (Denmark)
Oliveira, Sergio A.; Savi, Marcelo A.; Santos, Ilmar F.
2014-01-01
The use of shape memory alloys (SMAs) in engineering applications has increased the interest of the accuracy analysis of their thermomechanical description. This work presents an uncertainty analysis related to experimental tensile tests conducted with shape memory alloy wires. Experimental data...... are compared with numerical simulations obtained from a constitutive model with internal constraints employed to describe the thermomechanical behavior of SMAs. The idea is to evaluate if the numerical simulations are within the uncertainty range of the experimental data. Parametric analysis is also developed...
Sensitivity analysis explains quasi-one-dimensional current transport in two-dimensional materials
DEFF Research Database (Denmark)
Boll, Mads; Lotz, Mikkel Rønne; Hansen, Ole
2014-01-01
. The sensitivity analysis presents a formal definition of quasi-1D current transport, which was recently observed experimentally in chemical-vapor-deposition graphene. Our numerical model for calculating sensitivity is verified by comparing the model to analytical calculations based on conformal mapping...
Konno, Kohkichi; Nagasawa, Tomoaki; Takahashi, Rohta
2017-10-01
We discuss the scattering of a quantum particle by two independent successive point interactions in one dimension. The parameter space for two point interactions is given by U(2) × U(2) , which is described by eight real parameters. We perform an analysis of perfect resonant transmission on the whole parameter space. By investigating the effects of the two point interactions on the scattering matrix of plane wave, we find the condition under which perfect resonant transmission occurs. We also provide the physical interpretation of the resonance condition.
Ryu, Jaiyoung; Hu, Xiao; Shadden, Shawn C.
2015-11-01
The brain's CO2 reactivity mechanism is coupled with cerebral autoregulation and other unique features of cerebral hemodynamics. We developed a one-dimensional nonlinear model of blood flow in the cerebral arteries coupled to lumped parameter (LP) networks. The LP networks incorporate cerebral autoregulation, CO2 reactivity, intracranial pressure, cerebrospinal fluid, and cortical collateral blood flow models. The model was used to evaluate hemodynamic variables (arterial deformation, blood velocity and pressure) in the cerebral vasculature during hyperventilation and CO2 inhalation test. Tests were performed for various arterial blood pressure (ABP) representing normal and hypotensive conditions. The increase of the cerebral blood flow rates agreed well with the published measurements for various ABP measurements taken during clinical CO2 reactivity tests. The changes in distal vasculature affected the reflected pulse wave energy, which caused the waveform morphological changes at the middle cerebral, common and internal carotid arteries. The pulse morphological analysis demonstrated agreement with previous clinical measurements for cerebral vasoconstriction and vasodilation.
Directory of Open Access Journals (Sweden)
Liu Yu-Jen
2016-01-01
Full Text Available Electric arc is a discharge phenomenon caused by particular electrical events and arc produced facilities in power system, for example the occurrence of short-circuit fault in feeders and the use of electric arc furnace for steel-making. All of these electric arcs have a highly nonlinear nature and can be considered as a significant source of power quality problems. To investigate the impacts of the electric arcs on power quality studies the development of the electric arc models for simulation analysis is became necessary. This paper thus presents the use of different one-dimensional interpolation methods for modelling the alternating current electric arc. The performances of different methods are compared by simulation results that are derived from the modelling of an alternating current electric arc furnace load and a low-frequency fluorescent tube.
Energy Technology Data Exchange (ETDEWEB)
Kerstein, A.R. [Sandia National Lab., Livermore, CA (United States)
1996-12-31
One-Dimensional Turbulence is a new turbulence modeling strategy involving an unsteady simulation implemented in one spatial dimension. In one dimension, fine scale viscous and molecular-diffusive processes can be resolved affordably in simulations at high turbulence intensity. The mechanistic distinction between advective and molecular processes is thereby preserved, in contrast to turbulence models presently employed. A stochastic process consisting of mapping {open_quote}events{close_quote} applied to a one-dimensional velocity profile represents turbulent advection. The local event rate for given eddy size is proportional to the velocity difference across the eddy. These properties cause an imposed shear to induce an eddy cascade analogous in many respects to the eddy cascade in turbulent flow. Many scaling and fluctuation properties of self-preserving flows, and of passive scalars introduced into these flows, are reproduced.
Kuźnik, Krzysztof
2013-06-01
This paper introduces a grammar-based model for developing a multi-thread multi-frontal parallel direct solver for one- dimensional isogeometric finite element method. The model includes the integration of B-splines for construction of the element local matrices and the multi-frontal solver algorithm. The integration and the solver algorithm are partitioned into basic indivisible tasks, namely the grammar productions, that can be executed squentially. The partial order of execution of the basic tasks is analyzed to provide the scheduling for the execution of the concurrent integration and multi-frontal solver algo- rithm. This graph grammar analysis allows for optimal concurrent execution of all tasks. The model has been implemented and tested on NVIDIA CUDA GPU, delivering logarithmic execution time for linear, quadratic, cubic and higher order B-splines. Thus, the CUDA implementation delivers the optimal performance predicted by our graph grammar analysis. We utilize the solver for multiple right hand sides related to the solution of non-stationary or inverse problems.
Mahmood, Khalid; Rehman, Zia-ur-; Farooq, Khalid; Memon, Shazim Ali
2016-07-01
One dimensional equivalent linear ground response analysis was conducted in the Margalla Tower building in Islamabad, which collapsed during 2005 Muzaffarabad Earthquake. The analyses were conducted in DEEPSOIL software, without considering the effect of ground water table. The input subsoil data were selected from laboratory and field tests conducted for the site with bedrock at a depth of 21 m as per site condition. The field and laboratory testing data showed that the subsoil beneath the Tower site was silty clay to lean clay according to the unified soil classification system. Four different accelerograms with PGA values of 0.17 g, 0.15 g, 0.22 g and 0.21 g, compatible with the earthquake in the target area were applied at the bedrock. The surface response spectra showed that, except the Accelerogram-1 all other three were amplified near the fundamental period of the site. The analyses showed that different PGA values (0.26 g, 0.21 g, 0.36 g and 0.21 g) were produced at the surface which can be explained due to the difference in the Fourier amplitude of input accelerograms. Furthermore, the different input accelerograms produced a different shear strain and thus mobilized different shear strengths along the soil profile depth. Finally, the calculated response spectra of accelerograms were compared with the response spectra of Islamabad. The calculated spectral acceleration values were found to be higher than reported by the Building Code of Pakistan (0.16 g to 0.24 g).
Energy Technology Data Exchange (ETDEWEB)
Jiaxing, Cheng; Dongfa, Sheng [Southwest Forestry University, Yunnan (China)
2017-05-15
As an important supplement and development to crystallography, the applications about quasicrystal materials have played a core role in many fields, such as manufacturing and the space industry. Due to the sensitivity of quasicrystals to defects, the research on the fracture problem of quasicrystals has attracted a great deal of attention. We present a boundary collocation method to research fracture problems for a finite dimension rectangular one-dimensional hexagonal quasicrystal plate. Because mode I and mode II problems for one- dimensional hexagonal quasicrystals are like that for the classical elastic materials, only the anti-plane problem is discussed in this paper. The correctness of the present numerical method is verified through a comparison of the present results and the existing results. And then, the size effects on stress field, stress intensity factor and energy release rate are discussed in detail. The obtained results can provide valuable references for the fracture behavior of quasicrystals.
Abaie, Behnam; Hosseini, Seyed Rasoul; Karbasi, Salman; Mafi, Arash
2016-04-01
Impact of the boundaries on transversely localized modes of a truncated one-dimensional disordered optical lattice is numerically studied. The results show lower modal number density near the boundaries compared with the bulk, while the average decay rate of the tail of localized modes is the same near the boundaries as in the bulk. It is suggested that the perceived suppressed localization near the boundaries is due to a lower mode density: on average, it is less probable to excite a localized mode near the boundaries; however, once it is excited, its localization is with the same exponential decay rate as any other localized mode.
Pacheco, Shaun; Brand, Jonathan F; Zaverton, Melissa; Milster, Tom; Liang, Rongguang
2015-05-04
A method to design one-dimensional beam-spitting phase gratings with low sensitivity to fabrication errors is described. The method optimizes the phase function of a grating by minimizing the integrated variance of the energy of each output beam over a range of fabrication errors. Numerical results for three 1x9 beam splitting phase gratings are given. Two optimized gratings with low sensitivity to fabrication errors were compared with a grating designed for optimal efficiency. These three gratings were fabricated using gray-scale photolithography. The standard deviation of the 9 outgoing beam energies in the optimized gratings were 2.3 and 3.4 times lower than the optimal efficiency grating.
Gómez-Urrea, H. A.; Escorcia-García, J.; Duque, C. A.; Mora-Ramos, M. E.
2017-11-01
The transmittance spectrum of a one-dimensional hybrid photonic crystal built from the suitable arrangement of periodic and quasiregular Rudin-Shapiro heterolayers that include superconducting slabs is investigated. The four-layer Rudin-Shapiro structure is designed with three lossless dielectric layers and a low-temperature superconductor one. The dielectric function of the superconducting layer is modeled by the two-fluid Gorter-Casimir theory, and the transmittance is calculated with the use of the transfer matrix method. The obtained results reveal the presence of a cut-off frequency fc - a forbidden frequency band for propagation - that can be manipulated by changing the width of the superconducting layer, the temperature and the order of the Rudin-Shapiro sequence. In addition, the spatial distribution of the electric field amplitude for the propagating TM modes is also discussed. It is found that the maximum of localized electric field relative intensity - which reaches a value of several tens - corresponds to the frequency values above to the cut-off frequency, at which, the effective dielectric function of the hybrid unit cell becomes zero. The proposed structure could be another possible system for optical device design for temperature-dependent optical devices such as stop-band filters, or as bolometers.
Georgieva, Dessislava; Hildebrand, Diana; Simas, Rodrigo; Coronado, Monika A; Kwiatkowski, Marcel; Schlüter, Hartmut; Arni, Raghuvir; Spencer, Patrick; Betzel, Christian
2017-01-01
The Pseudechis colletti and Pseudechis butleri venoms were analyzed by 1-D gel electrophoresis, followed by mass spectrometric analysis of tryptic peptides obtained from the protein bands. Both venoms contain highly potent pharmacologically active components, which were assigned to the following protein families: basic and acidic phospholipases A2 (PLA2s), L-amino acid oxidases (LAAOs), P-III metalloproteinases (P-III SVMPs), 5'- nucleotidases (5'-NTDs), cysteine-rich secretory proteins (CRISPs), venom nerve growth factors (VNGFs) and post-synaptic neurotoxins. Considerable predominance of PLA2s over other toxins is a characteristic feature of both venoms. The major differences in the venom compositions are the higher concentration of SVMPs and CRISPs in the P. butleri venom, as well as the presence of post-synaptic neurotoxins. Furthermore, the analysis revealed a high concentration of proteins with myotoxic, coagulopathic and apoptotic activities. PLA2s are responsible for the myotoxic and anticoagulant effects observed in patients after envenomation (4). The other protein families, encountered in the two venoms, probably contribute to the major symptoms described for these venoms. These results explain the observed clinical effects of the black snake envenomation. The analyzed venoms contain group P-III metalloproteinases of medical importance with the potency to be used for diagnostic purposes of von Willebrand factor (vWF) disease, for regulation of vWF in thrombosis and haemostasis, for studying the function of the complement system in host defense and in the pathogenesis of diseases. Comparison of venomic data showed similarities in the major venom components of snakes from the genus Pseudechis, resulting in common clinical effects of envenomation, and demonstrating close relationships between venom toxins of Elapidae snakes. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
Pseudo-observations in survival analysis
DEFF Research Database (Denmark)
Andersen, Per Kragh; Perme, Maja Pohar
2010-01-01
-state models, e.g. the competing risks cumulative incidence function. Graphical and numerical methods for assessing goodness-of-fit for hazard regression models and for the Fine-Gray model in competing risks studies based on pseudo-observations are also reviewed. Sensitivity to covariate-dependent censoring...... is studied. The methods are illustrated using a data set from bone marrow transplantation....
Singh, Sachin K; Lakshmi, Mula G Meena; Saxena, Sandeep; Swamy, Cherukuvada V Brahmendra; Idris, Mohammed M
2011-01-01
Zebrafish (Danio rerio) is the widely used vertebrate model animal for understanding the complexity of development and disease process. Zebrafish has been also extensively used in understanding the mechanism of regeneration for its extensive capability of regenerating fins and other tissues. We have analyzed the proteome profile of zebrafish caudal fin in its native state based on one-dimensional gel electrophoresis LCMS/MS and two-dimensional gel electrophoresis MS/MS analyses. A total of 417 proteins were identified as zebrafish fin tissue specific, which includes 397 proteins identified based on one-dimensional gel electrophoresis LCMS/MS analysis and 101 proteins identified based on two-dimensional gel electrophoresis MALDI MS/MS. The proteins mapped to the zebrafish fin tissue were shown to be involved in various biological activities related to development, apoptosis, signaling and metabolic process. Focal adhesion, regulation of actin cytoskeleton, cancer-related pathways, mitogen-activated protein kinase signaling, antigen processing and presentation, and proteasome are some of the important pathways associated with the identified proteome data set of the zebrafish fin. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Pan, JianHua; Ren, YuXin
2017-08-01
In this paper, a family of sub-cell finite volume schemes for solving the hyperbolic conservation laws is proposed and analyzed in one-dimensional cases. The basic idea of this method is to subdivide a control volume (main cell) into several sub-cells and the finite volume discretization is applied to each of the sub-cells. The averaged values on the sub-cells of current and face neighboring main cells are used to reconstruct the polynomial distributions of the dependent variables. This method can achieve arbitrarily high order of accuracy using a compact stencil. It is similar to the spectral volume method incorporating with PNPM technique but with fundamental differences. An elaborate utilization of these differences overcomes some shortcomings of the spectral volume method and results in a family of accurate and robust schemes for solving the hyperbolic conservation laws. In this paper, the basic formulation of the proposed method is presented. The Fourier analysis is performed to study the properties of the one-dimensional schemes. A WENO limiter based on the secondary reconstruction is constructed.
Directory of Open Access Journals (Sweden)
William Hansen
2017-12-01
Full Text Available A striking difference between the folk-narrative genres of legend and folktale is how the human characters respond to supernatural, otherworldly, or uncanny beings such as ghosts, gods, dwarves, giants, trolls, talking animals, witches, and fairies. In legend the human actors respond with fear and awe, whereas in folktale they treat such beings as if they were ordinary and unremarkable. Since folktale humans treat all characters as belonging to a single realm, folklorists have described the world of the folktale as one-dimensional, in contrast to the two-dimensionality of the legend. The present investigation examines dimensionality in the third major genre of folk narrative: myth. Using the Greek and Hebrew myths of primordial paradise as sample narratives, the present essay finds—surprisingly—that the humans in these stories respond to the otherworldly one-dimensionally, as folktale characters do, and suggests an explanation for their behavior that is peculiar to the world of myth.
Velázquez-Campoy, Adrián
2006-01-01
The theory developed by McGhee and von Hippel for ligand binding to a one-dimensional lattice-like macromolecule provides a closed analytical form in the Scatchard representation. The application of such theory has been complicated by two facts: (1) it has been practically reduced to binding techniques, such as equilibrium dialysis, in which the partition between bound and free concentrations of all reactant species are directly accessible and experimentally determined, but infrequently applied to other binding techniques, such as calorimetry or spectroscopy, in which the direct observable is a magnitude proportional to the advance of the binding reaction monitored along the titration experiment, and (2) Scatchard analysis, developed as a quantitative graphical method, is currently outdated and used only qualitatively because of its weaknesses, limitations, and deficiencies. However, a general exact method for applying such theory to titration techniques in a correct and precise manner, without any limitation, can be delineated. In this article, the theory of cooperative ligand binding to linear lattice-like macromolecules has been implemented in isothermal titration calorimetry for the first time. This technique provides a complete thermodynamic characterization of ligand binding, but it has been barely used properly for this type of system. The description, the analysis of the formalism, and practical guidelines are presented, with considerations for experimental design and data analysis.
Gyergyek, T; Kovačič, J
2017-06-01
A one-dimensional, two-fluid, steady state model is used for the analysis of ion temperature effects to the plasma-wall transition. In this paper, the model is solved for a finite ratio ε between the Debye and the ionization length, while in Part II [T. Gyergyek and J. Kovačič, Phys Plasmas 24, 063506 (2017)], the solutions for [Formula: see text] are presented. Ion temperature is treated as a given, independent parameter and it is included in the model as a boundary condition. It is shown that when the ion temperature larger than zero is selected, the ion flow velocity and the electric field at the boundary must be consistent with the selected ion temperature. A numerical procedure, how to determine such "consistent boundary conditions," is proposed, and a simple relation between the ion temperature and ion velocity at the boundary of the system is found. The effects of the ion temperature to the pre-sheath length, potential, ion temperature, and ion density drops in the pre-sheath and in the sheath are investigated. It is concluded that larger ion temperature results in a better shielding of the plasma from the wall. An attempt is made to include the ion heat flux q i into the model in its simplest form [Formula: see text], where [Formula: see text] is a constant heat conduction coefficient. It is shown that inclusion of such a term into the energy transfer equation introduces an additional ion heating mechanism into the system and the ion flow then becomes isothermal instead of adiabatic even in the sheath.
He, Min; Yang, Zhi-Yu; Yang, Tian-Biao; Ye, Ying; Nie, Juan; Hu, Yong; Yan, Pan
2017-05-01
Chemometrics-enhanced one-dimensional/comprehensive two-dimensional gas chromatographic (GC/GC×GC) technologies, were used to explore the compositions of Chaihu Shugan San essential oils, that were extracted from the herbal formulae by different schemes. We have shown that chemometric resolution using gas chromatographic- mass spectrometry (GC-MS) could be used for the qualitative and quantitative analysis of the majority of Terpenoids or Phthalides from herb formulae and single herbs. A GC×GC system was further optimized to achieve the increased peak capacity and the enhanced signal of the hydro-distillation sample (CSSh). When hardware bottleneck resulted from very complex sample, chemometric tools were once again applied to recover the stained information in the second dimension ( 2 D) matrix data. Heuristic evolving latent projections (HELP) could be used for two dimensional (2D) sub-matrixes Xi at n spectral detection channels, after three dimensional (3D) data splitting. For a real 3D data matrix, alternating trilinear decomposition (ATLD) algorithm could conduct regularization for an iterative trilinear decomposition procedure, by Moore-Penrose pseudoinverse computations based on singular value decomposition. After retention indices (RI) confirmation, 216 target analytes (terpenoids or phthalides) could be elucidated both in CSSh and in supercritical fluid extract (CSSs). Based on the obtained data, some potential quality markers (Q-markers) were identified which may affect the quality of the products. Finally, a "connectivity map" was plotted to describe the unique mechanisms of tradition Chinese medicine (TCM). Copyright © 2017 Elsevier B.V. All rights reserved.
International conference Fourier Analysis and Pseudo-Differential Operators
Turunen, Ville; Fourier Analysis : Pseudo-differential Operators, Time-Frequency Analysis and Partial Differential Equations
2014-01-01
This book is devoted to the broad field of Fourier analysis and its applications to several areas of mathematics, including problems in the theory of pseudo-differential operators, partial differential equations, and time-frequency analysis. This collection of 20 refereed articles is based on selected talks given at the international conference “Fourier Analysis and Pseudo-Differential Operators,” June 25–30, 2012, at Aalto University, Finland, and presents the latest advances in the field. The conference was a satellite meeting of the 6th European Congress of Mathematics, which took place in Krakow in July 2012; it was also the 6th meeting in the series “Fourier Analysis and Partial Differential Equations.”
Finite Element Analysis of the Pseudo-elastic Behavior of Shape Memory Alloy Truss and Beam
Directory of Open Access Journals (Sweden)
Kamal M. Bajoria
2010-07-01
Full Text Available The pseudo-elastic behavior of Shape memory alloy (SMA truss and cantilever beam are investigated. Brinson’s one-dimensional material model, which uses the twinned and detwinned martensite fractions separately as internal variables, is applied in the algorithm to establish the SMA stress-strain characteristics. This material model also incorporates different young’s modulus for austenitic and martensite phase to represent the true SMA characteristics. In this model, a cosine function was used to express the evolution of the stress induced martensite fractions during the forward and reverse martensite phase transformation. A finite element formulation for the SMA truss member considering the geometric nonlinearity is proposed and the results are compared with the corresponding linear analysis. As a step forward, a finite element formulation for an SMA cantilever beam with an applied end moment is proposed. The load displacement characteristic for both the loading and unloading phases are considered to check the full pseudo-elastic hysteretic loop. In the numerical investigation, the stress-strain variation along the beam depth is also examined during the loading and unloading process to investigate the forward and reverse martensite phase transformation phenomena. Newton-Raphson’s iterative method is applied to get convergence to the equilibrium for each loading steps. During a complete loading-unloading process, the temperature is kept constant as the model is essentially an isothermal model. Numerical simulation is performed considering two different temperatures to demonstrate the effect of temperature on the hysteretic loop.
Regression analysis of restricted mean survival time based on pseudo-observations
DEFF Research Database (Denmark)
Andersen, Per Kragh; Hansen, Mette Gerster; Klein, John P.
censoring; hazard function; health economics; regression model; survival analysis; mean survival time; restricted mean survival time; pseudo-observations......censoring; hazard function; health economics; regression model; survival analysis; mean survival time; restricted mean survival time; pseudo-observations...
Regression Analysis of Restricted Mean Survival Time Based on Pseudo-Observations
DEFF Research Database (Denmark)
Andersen, Per Kragh; Hansen, Mette Gerster; Klein, John P.
2004-01-01
censoring; hazard function; health economics; mean survival time; pseudo-observations; regression model; restricted mean survival time; survival analysis......censoring; hazard function; health economics; mean survival time; pseudo-observations; regression model; restricted mean survival time; survival analysis...
Gyergyek, T.; Kovačič, J.
2017-06-01
A one-dimensional, steady state, two fluid model, presented in Part I [T. Gyergyek and J. Kovačič, Phys. Plasmas 24, 063505 (2017)] is extended to the asymptotic two-scale limit. Separate solutions in the pre-sheath and in the sheath region are presented. Ion temperature is treated as an independent parameter, which is included in the model as a boundary condition. For the pre-sheath solutions, it is shown that when the ion temperature is increased, the ion flow velocity at the boundary of the system must also be increased. A simple relationship between ion temperature and ion flow velocity at the boundary is found. This relationship is the same as the corresponding relationship found in Part I. If ion temperature is increased, both the potential drop and the density drop in the pre-sheath decrease. The same is true for the pre-sheath length. As for the solutions in the sheath scale, it is shown that the ion velocity, electron velocity, and electric field at the sheath edge must all be above a certain minimum value in order to obtain physically acceptable monotonic solutions. It is proposed to select the ion velocity at the sheath edge equal to the ion sound velocity. If, at the same time, the zero electron flow velocity at the sheath edge is selected, the electric field at the sheath edge must be larger than roughly 3 × 10-6, in order to obtain monotonic solutions of the model. The selection of the electron velocity at the sheath edge is elaborated extensively. It is concluded that increased ion temperature improves the shielding of the plasma from the electrode.
One-Dimensional Czedli-Type Islands
Horvath, Eszter K.; Mader, Attila; Tepavcevic, Andreja
2011-01-01
The notion of an island has surfaced in recent algebra and coding theory research. Discrete versions provide interesting combinatorial problems. This paper presents the one-dimensional case with finitely many heights, a topic convenient for student research.
ANALYSIS OF THE CHEMICAL COMPOSITION AND MORPHOLOGICAL STRUCTURE OF BANANA PSEUDO-STEM
Kun Li; Shiyu Fu; Huaiyu Zhan; Yao Zhan; Lucian A. Lucia
2010-01-01
An analysis of the chemical composition and anatomical structure of banana pseudo-stem was carried out using Light Microscopy (LM), Scanning Electron Microscopy (SEM), and Confocal Laser Scanning Microscopy (CLSM). The chemical analysis indicated there is a high holocellulose content and low lignin content in banana pseudo-stem compared with some other non-wood fiber resources. These results demonstrate that the banana pseudo-stem has potential value for pulping. In addition, we report for th...
Heredity in one-dimensional quadratic maps
Romera, M.; Pastor, G.; Alvarez, G.; Montoya, F.
1998-12-01
In an iterative process, as is the case of a one-dimensional quadratic map, heredity has never been mentioned. In this paper we show that the pattern of a superstable orbit of a one-dimensional quadratic map can be expressed as the sum of the gene of the chaotic band where the pattern is to be found, and the ancestral path that joins all its ancestors. The ancestral path holds all the needed genetic information to calculate the descendants of the pattern. The ancestral path and successive descendant generations of the pattern constitute the family tree of the pattern, which is important to study and understand the orbit's ordering.
Bennett, Keiryn L; Funk, Marion; Tschernutter, Marion; Breitwieser, Florian P; Planyavsky, Melanie; Ubaida Mohien, Ceereena; Müller, André; Trajanoski, Zlatko; Colinge, Jacques; Superti-Furga, Giulio; Schmidt-Erfurth, Ursula
2011-02-01
In this study, we report a comparative and quantitative analysis by mass spectrometry of the protein content of aqueous humour from cataract (control) patients. In addition to protein profiling, the approach is layered with quantitative proteomics using the iTRAQ® methodology. Aqueous humour from ten clinically-matched patients was collected and depleted of albumin and immunoglobulin G. Pairs of patient material were pooled and divided into three aliquots for subsequent analysis by alternative proteomic approaches. Excluding keratin, trypsin, residual albumin and immunoglobulins, a total of 198 protein groups were identified across the entire study. Relative protein quantitation with iTRAQ® revealed that 88% of the proteins had a maximal ±2-fold differential regulation between 3 of the 4 labelled samples, indicating minimal variation. The identified proteins were categorised by gene ontology and one third of the proteins were annotated as extracellular. The major molecular functions of the proteins in aqueous humour are binding (protein, metal ion, heparin, and DNA) and inhibition of proteolytic activity. Complementary to molecular function, the predominant biological processes for the proteins in aqueous humour are assigned to inflammatory and immune responses, and transport. Copyright © 2010 Elsevier B.V. All rights reserved.
Highly conducting one-dimensional solids
Evrard, Roger; Doren, Victor
1979-01-01
Although the problem of a metal in one dimension has long been known to solid-state physicists, it was not until the synthesis of real one-dimensional or quasi-one-dimensional systems that this subject began to attract considerable attention. This has been due in part to the search for high temperature superconductivity and the possibility of reaching this goal with quasi-one-dimensional substances. A period of intense activity began in 1973 with the report of a measurement of an apparently divergent conduc tivity peak in TfF-TCNQ. Since then a great deal has been learned about quasi-one-dimensional conductors. The emphasis now has shifted from trying to find materials of very high conductivity to the many interesting problems of physics and chemistry involved. But many questions remain open and are still under active investigation. This book gives a review of the experimental as well as theoretical progress made in this field over the last years. All the chapters have been written by scientists who have ...
Remarks for one-dimensional fractional equations
Directory of Open Access Journals (Sweden)
Massimiliano Ferrara
2014-01-01
Full Text Available In this paper we study a class of one-dimensional Dirichlet boundary value problems involving the Caputo fractional derivatives. The existence of infinitely many solutions for this equations is obtained by exploiting a recent abstract result. Concrete examples of applications are presented.
QUASI-ONE DIMENSIONAL CLASSICAL FLUIDS
Directory of Open Access Journals (Sweden)
J.K.Percus
2003-01-01
Full Text Available We study the equilibrium statistical mechanics of simple fluids in narrow pores. A systematic expansion is made about a one-dimensional limit of this system. It starts with a density functional, constructed from projected densities, which depends upon projected one and two-body potentials. The nature of higher order corrections is discussed.
One-dimensional oscillator in a box
Energy Technology Data Exchange (ETDEWEB)
Amore, Paolo [Facultad de Ciencias, Universidad de Colima, Bernal DIaz del Castillo 340, Colima, Colima (Mexico); Fernandez, Francisco M [INIFTA (UNLP, CCT La Plata-CONICET), Division Quimica Teorica, Blvd 113 S/N, Sucursal 4, Casilla de Correo 16, 1900 La Plata (Argentina)], E-mail: paolo@ucol.mx, E-mail: fernande@quimica.unlp.edu.ar
2010-01-15
We discuss a quantum-mechanical model of two particles that interact by means of a harmonic potential and are confined to a one-dimensional box with impenetrable walls. We apply perturbation theory to the cases of different and equal masses and analyse the symmetry of the states in the latter case. We compare the approximate perturbation results with accurate numerical ones.
One-dimensional nanomaterials: Synthesis and applications
Lei, Bo
My research mainly covers three types of one-dimensional (1D) nanomaterials: metal oxide nanowires, transition metal oxide core-shell nanowires and single-walled carbon nanotubes. This new class of nanomaterials has generated significant impact in multiple fields including electronics, medicine, computing and energy. Their peculiar, fascinating properties are promising for unique applications on electronics, spintronics, optical and chemical/biological sensing. This dissertation will summarize my research work on these three 1D nanomaterials and propose some ideas that may lead to further development. Chapter 1 will give a brief introduction of nanotechnology journey and 1D nanomaterials. Chapter 2 and 3 will discuss indium oxide nanowires, as the representative of metal oxide nanwires. More specifically, chapter 2 is focused on the synthesis, material characterization, transport studies and doping control of indium oxide nanowires; Chapter 3 will give a comprehensive review of our systematic studies on molecular memory applications based on molecule/indium oxide nanowire heterostructures. Chapter 4 will introduce another 1D nanomaterial-transition metal oxide (TMO) core-shell nanowires. The discuss will focus on the synthesis of TMO nanowires, material analysis and their electronic properties as a function of temperature and magnetic field. Chapter 5 is dedicated to aligned single-walled carbon nanotubes (SWNTs) on synthesis with rational control of position and orientation, detailed characterization and construction of scaled top-gated transistors. This chapter presents a way to produce the p- and n-type nanotube transistors based on gate voltage polarity control during electrical breakdown. Finally, chapter 6 summarizes the above discussions and proposes some suggestions for future studies.
Realization of Configurable One-Dimensional Reflectarray
2017-08-31
instrument is shown in Figure 8. The light source consists of a tunable quantum cascade laser that operates in the range of λ = 6 - 12 µm. A series of...Ellis CT, Abell J, Glembocki OJ, Canedy CL, Tischler JG, Vurgaftman I, Meyer JR. Resonant quantum efficiency enhancement of midwave infrared nBn...photodetectors using one-dimensional plasmonic gratings. Applied Physics Letters. 2015 Jun 29;106(26):261109. 4. Yan H, Low T, Zhu W, Wu Y, Freitag M
On the one-dimensional Coulomb problem
Energy Technology Data Exchange (ETDEWEB)
Jaramillo, Benjamin [Instituto de Fisica, Universidad de Guanajuato, Loma del Bosque 103, Fracc. Lomas del Campestre, CP 37150 Leon, Guanajuato (Mexico); Martinez-y-Romero, R.P. [Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, Apartado Postal 21-267, CP 04000, Coyoacan, D.F. (Mexico); Nunez-Yepez, H.N. [Departamento Fisica, Universidad Autonoma Metropolitana-Iztapalapa, Apartado Postal 55-534, CP 09340, Iztapalapa, D.F. (Mexico); Salas-Brito, A.L., E-mail: asb@correo.azc.uam.m [Laboratorio de Sistemas Dinamicos, Departamento de Ciencias Basicas, Universidad Autonoma Metropolitana-Azcapotzalco, Apartado Postal 21-267, CP 04000, Coyoacan, D.F. (Mexico)
2009-12-28
We analyse the one-dimensional Coulomb problem (1DCP) pointing out some mistaken beliefs on it. We show that no eigenstates of even or odd parity can represent states of the system. The 1DCP exhibits a sort of spontaneous breaking of parity. We also show that a superselection rule operates in the system. Such rule explains some of its peculiarities. We build the superpotential associated to the 1DCP.
The Long Decay Model of One-Dimensional Projectile Motion
Lattery, Mark Joseph
2008-01-01
This article introduces a research study on student model formation and development in introductory mechanics. As a point of entry, I present a detailed analysis of the Long Decay Model of one-dimensional projectile motion. This model has been articulated by Galileo ("in De Motu") and by contemporary students. Implications for instruction are…
Teaching Module for One-Dimensional, Transient Conduction.
Ribando, Robert J.; O'Leary, Gerald W.
1998-01-01
Describes a PC-based teaching module designed to instruct engineering students in transient one-dimensional conduction heat transfer analysis. The discussion considers problem formulation, nondimensionalization, discretization, numerical stability and the time-step restriction, program operation, and program verification. (MES)
Underwater striling engine design with modified one-dimensional model
Directory of Open Access Journals (Sweden)
Daijin Li
2015-05-01
Full Text Available Stirling engines are regarded as an efficient and promising power system for underwater devices. Currently, many researches on one-dimensional model is used to evaluate thermodynamic performance of Stirling engine, but in which there are still some aspects which cannot be modeled with proper mathematical models such as mechanical loss or auxiliary power. In this paper, a four-cylinder double-acting Stirling engine for Unmanned Underwater Vehicles (UUVs is discussed. And a one-dimensional model incorporated with empirical equations of mechanical loss and auxiliary power obtained from experiments is derived while referring to the Stirling engine computer model of National Aeronautics and Space Administration (NASA. The P-40 Stirling engine with sufficient testing results from NASA is utilized to validate the accuracy of this one-dimensional model. It shows that the maximum error of output power of theoretical analysis results is less than 18% over testing results, and the maximum error of input power is no more than 9%. Finally, a Stirling engine for UUVs is designed with Schmidt analysis method and the modified one-dimensional model, and the results indicate this designed engine is capable of showing desired output power.
One-dimensional interacting topological insulator
Guo, Huaiming; Shen, Shun-Qing
2013-08-01
The one-dimensional interacting topological insulator is studied by means of exact diagonalization method. The topological properties are examined with the existence of the edge states and the quantized Berry phase at half-filling. It is found that the topological phases are not only robust to small repulsive interactions but also are stabilized by small attractive interactions, and also finite repulsive interaction can drive a topological non-trivial phase into a trivial one while the attractive interaction can drive a trivial phase into a non-trivial one. These results could be realized experimentally using cold atoms trapped in the 1D optical lattice.
One-dimensional nanostructures principles and applications
Zhai, Tianyou
2012-01-01
Reviews the latest research breakthroughs and applications Since the discovery of carbon nanotubes in 1991, one-dimensional nanostructures have been at the forefront of nanotechnology research, promising to provide the building blocks for a new generation of nanoscale electronic and optoelectronic devices. With contributions from 68 leading international experts, this book reviews both the underlying principles as well as the latest discoveries and applications in the field, presenting the state of the technology. Readers will find expert coverage of all major classes of one-di
Regression analysis of censored data using pseudo-observations
DEFF Research Database (Denmark)
Overgaard, Morten; Andersen, Per K.; Parner, Erik T.
2015-01-01
We present updated versions of the stpsurv, stpci, and stpmean commands, which were introduced in Parner and Andersen (2010, Stata Journal 10: 408–422), along with a new command, stplost. The commands generate pseudo-observations of the survival function, the cumulative incidence function under...... commands feature new options, an increase in computational speed, and the ability to handle survival data with delayed entry....
Energy Technology Data Exchange (ETDEWEB)
Fullmer, William D.; Ransom, Victor H.; Lopez de Bertodano, Martin A., E-mail: bertodan@purdue.edu
2014-03-15
For nuclear reactor safety analysis, the one-dimensional two-fluid model equations are solved numerically with the first order upwind method because of its robust stability. In the present two-fluid model for horizontal stratified flow, surface tension is included because it makes the model well-posed. However, this is not done in industrial applications and numerical viscosity provides linear stabilization even when the model is ill-posed. It is now shown that numerical viscosity also provides nonlinear stabilization; meaning that the wave growth is bounded when the flow is unstable (e.g., in case of the Kelvin–Helmholtz instability). The formation of kinematic shocks in the presence of numerical viscosity provides the dissipation mechanism needed to stop the wave growth. However, numerical viscosity varies with the mesh size, which means that even though the unstable model is well-posed and meets von Neumann and nonlinear stabilization requirements, the solution does not converge for some short wavelengths greater than 2Δx. Furthermore, when the mesh size is large, significant artificial viscosity is added to the continuity and momentum equations and the model may become over-stabilized. A more scientific approach is proposed: to add a physical dissipation mechanism instead of numerical viscosity, i.e., Reynolds stresses. This approach has two advantages: first, the one-dimensional two-fluid model converges under severe dynamic conditions, such as the Kelvin–Helmholtz instability, and second, a higher order numerical method may be used instead of the first order upwind scheme without experiencing numerical excursions.
Krupčík, Ján; Gorovenko, Roman; Špánik, Ivan; Bočková, Ingrid; Sandra, Pat; Armstrong, Daniel W
2013-08-02
One-dimensional and comprehensive two-dimensional flow modulated gas chromatography with simultaneous flame ionization and mass spectrometric detection were applied for the identification and quantification of benzene, toluene, ethyl benzene and xylenes (BTEX) as well as of all C9-C11 aromatic hydrocarbons in the low-boiling petroleum products gasoline, reformate and fluid catalytic cracking (FCC) samples. GC×GC experiments were performed on two reversed phase polarity column sets namely SLB-IL100 (25m×250μm i.d.×0.2μm df)+HP-5MS (5m×250μm i.d.×0.25μm df) and SLB-IL111 (30m×250μm i.d.×0.2μm df)+HP-5MS (5m×250μm i.d.×0.25μm df). The one-dimensional GC experiments were carried out on the same ionic liquid columns. The most powerful method is GC×GC on the SLB-111+HP-5MS column combination. Quantitative analysis of individual aromatic hydrocarbons (C6-C11) present in gasoline, reformate and fluid catalytic cracking (FCC) samples was performed by GC×GC-FID using the internal normalization method. Mass spectra obtained by GC×GC-qMSD were used for identification of the aromatic hydrocarbons in these samples. Copyright © 2013 Elsevier B.V. All rights reserved.
Specificities of one-dimensional dissipative magnetohydrodynamics
Energy Technology Data Exchange (ETDEWEB)
Popov, P. V., E-mail: popov.pv@mipt.ru [National Research Center Kurchatov Institute (Russian Federation)
2016-11-15
One-dimensional dynamics of a plane slab of cold (β ≪ 1) isothermal plasma accelerated by a magnetic field is studied in terms of the MHD equations with a finite constant conductivity. The passage to the limit β → 0 is analyzed in detail. It is shown that, at β = 0, the character of the solution depends substantially on the boundary condition for the electric field at the inner plasma boundary. The relationship between the boundary condition for the pressure at β > 0 and the conditions for the electric field at β = 0 is found. The stability of the solution against one-dimensional longitudinal perturbations is analyzed. It is shown that, in the limit β → 0, the stationary solution is unstable if the time during which the acoustic wave propagates across the slab is longer than the time of magnetic field diffusion. The growth rate and threshold of instability are determined, and results of numerical simulation of its nonlinear stage are presented.
One-dimensional nanomaterials for energy storage
Chen, Cheng; Fan, Yuqi; Gu, Jianhang; Wu, Liming; Passerini, Stefano; Mai, Liqiang
2018-03-01
The search for higher energy density, safer, and longer cycling-life energy storage systems is progressing quickly. One-dimensional (1D) nanomaterials have a large length-to-diameter ratio, resulting in their unique electrical, mechanical, magnetic and chemical properties, and have wide applications as electrode materials in different systems. This article reviews the latest hot topics in applying 1D nanomaterials, covering both their synthesis and their applications. 1D nanomaterials can be grouped into the categories: carbon, silicon, metal oxides, and conducting polymers, and we structure our discussion accordingly. Then, we survey the unique properties and application of 1D nanomaterials in batteries and supercapacitors, and provide comments on the progress and advantages of those systems, paving the way for a better understanding of employing 1D nanomaterials for energy storage.
Superfluid helium-4 in one dimensional channel
Kim, Duk Y.; Banavar, Samhita; Chan, Moses H. W.; Hayes, John; Sazio, Pier
2013-03-01
Superfluidity, as superconductivity, cannot exist in a strict one-dimensional system. However, the experiments employing porous media showed that superfluid helium can flow through the pores of nanometer size. Here we report a study of the flow of liquid helium through a single hollow glass fiber of 4 cm in length with an open id of 150 nm between 1.6 and 2.3 K. We found the superfluid transition temperature was suppressed in the hollow cylinder and that there is no flow above the transition. Critical velocity at temperature below the transition temperature was determined. Our results bear some similarity to that found by Savard et. al. studying the flow of helium through a nanohole in a silicon nitrite membrane. Experimental study at Penn State is supported by NSF Grants No. DMR 1103159.
One dimensional systems with singular perturbations
Energy Technology Data Exchange (ETDEWEB)
Alvarez, J J [Departamento de Informatica, E.U. de Informatica, Universidad de Valladolid, 40005 Segovia (Spain); Gadella, M; Nieto, L M [Departamento de FTAO, University of Valladolid, 47071 Valladolid (Spain); Glasser, L M [Department of Physics, Clarkson University, Potsdam, NY 13699-5820 (United States); Lara, L P, E-mail: jjalvarez@infor.uva.es, E-mail: manuelgadella1@gmail.com, E-mail: laryg@clarkson.edu, E-mail: lplara@fceia.unr.edu.ar, E-mail: luismi@metodos.fam.cie.uva.es [Departamento de Sistemas, FRRO, Zevallos 1345, Rosario (Argentina)
2011-03-01
This paper discusses some one dimensional quantum models with singular perturbations. Eventually, a mass discontinuity is added at the points that support the singular perturbations. The simplest model includes an attractive singular potential with a mass jump both located at the origin. We study the form of the only bound state. Another model exhibits a hard core at the origin plus one or more repulsive deltas with mass jumps at the points supporting these deltas. We study the location and the multiplicity of these resonances for the case of one or two deltas and settle the basis for a generalization. Finally, we consider the harmonic oscillator and the infinite square well plus a singular potential at the origin. We see how the energy of bound states is affected by the singular perturbation.
Unitary equivalence classes of one-dimensional quantum walks II
Ohno, Hiromichi
2017-12-01
This study investigated the unitary equivalence classes of one-dimensional quantum walks with and without initial states. We determined the unitary equivalence classes of one-dimensional quantum walks, two-phase quantum walks with one defect, complete two-phase quantum walks, one-dimensional quantum walks with one defect and translation-invariant one-dimensional quantum walks.
Few quantum particles on one dimensional lattices
Energy Technology Data Exchange (ETDEWEB)
Valiente Cifuentes, Manuel
2010-06-18
There is currently a great interest in the physics of degenerate quantum gases and low-energy few-body scattering due to the recent experimental advances in manipulation of ultracold atoms by light. In particular, almost perfect periodic potentials, called optical lattices, can be generated. The lattice spacing is fixed by the wavelength of the laser field employed and the angle betwen the pair of laser beams; the lattice depth, defining the magnitude of the different band gaps, is tunable within a large interval of values. This flexibility permits the exploration of different regimes, ranging from the ''free-electron'' picture, modified by the effective mass for shallow optical lattices, to the tight-binding regime of a very deep periodic potential. In the latter case, effective single-band theories, widely used in condensed matter physics, can be implemented with unprecedent accuracy. The tunability of the lattice depth is nowadays complemented by the use of magnetic Feshbach resonances which, at very low temperatures, can vary the relevant atom-atom scattering properties at will. Moreover, optical lattices loaded with gases of effectively reduced dimensionality are experimentally accessible. This is especially important for one spatial dimension, since most of the exactly solvable models in many-body quantum mechanics deal with particles on a line; therefore, experiments with one-dimensional gases serve as a testing ground for many old and new theories which were regarded as purely academic not so long ago. The physics of few quantum particles on a one-dimensional lattice is the topic of this thesis. Most of the results are obtained in the tight-binding approximation, which is amenable to exact numerical or analytical treatment. For the two-body problem, theoretical methods for calculating the stationary scattering and bound states are developed. These are used to obtain, in closed form, the two-particle solutions of both the Hubbard and
One-dimensional dynamics of nearly unstable axisymmetric liquid bridges
Perales, José M.; Vega, José M.
2010-11-01
A general one-dimensional model is considered that describes the dynamics of slender, axisymmetric, noncylindrical liquid bridges between two equal disks. Such model depends on two adjustable parameters and includes as particular cases the standard Lee and Cosserat models. For slender liquid bridges, the model provides sufficiently accurate results and involves much easier and faster calculations than the full three-dimensional model. In particular, viscous effects are easily accounted for. The one-dimensional model is used to derive a simple weakly nonlinear description of the dynamics near the instability limit. Small perturbations of marginal instability conditions are also considered that account for volume perturbations, nonequality of the supporting disks, and axial gravity. The analysis shows that the dynamics breaks the reflection symmetry on the midplane between the supporting disks. The weakly nonlinear evolution of the amplitude of the perturbation is given by a Duffing equation, whose coefficients are calculated in terms of the slenderness as a part of the analysis and exhibit a weak dependence on the adjustable parameters of the one-dimensional model. The amplitude equation is used to make quantitative predictions of both the (first stage of) breakage for unstable configurations and the (slow) dynamics for stable configurations.
Energy Technology Data Exchange (ETDEWEB)
Fujikubo, M.; Yao, T.; Oida, H. [Hiroshima University, Hiroshima (Japan). Faculty of Engineering
1996-12-31
Formulation was made on a one-dimensional beam finite element which is effective in analyzing structural response of very large floating structures by modeling them on beams on an elastic foundation. This element allows strict solution of vibration response in the beams on the elastic foundation to be calculated efficiently for a case where mass and rigidity change in the longitudinal direction. This analysis method was used to analyze structural response of a large pontoon-type floating structure to investigate mass in the end part for the structural response and the effect of decay while passing the structure. With a pontoon-type floating structure, reduction in bends and bending stress in the end part of the floating structure is important in designing the structure. Reducing the mass in the end part is effective as a means to avoid resonance in these responses and reduce the responses. Increase in rigidity of a floating structure shifts the peak in quasi-static response to lower frequency side, and reduces response in resonance, hence it is advantageous for improving the response. Since incident waves decay while passing through the floating structure, response in the lower wave side decreases. The peak frequency in the quasi-static response also decreases at the end part of the structure in the upper wave side due to decay in wave force. 7 refs., 11 figs., 1 tab.
Pseudo-nonlinear dynamic analysis of buckled pipes
Gültekin Sınır, B.
2013-02-01
In this study, the post-divergence behavior of fluid-conveying pipes supported at both ends is investigated using the nonlinear equations of motion. The governing equation exhibits a cubic nonlinearity arising from mid-plane stretching. Exact solutions for post-buckling configurations of pipes with fixed-fixed, fixed-hinged, and hinged-hinged boundary conditions are investigated. The pipe is stable at its original static equilibrium position until the flow velocity becomes high enough to cause a supercritical pitchfork bifurcation, and the pipe loses stability by static divergence. In the supercritical fluid velocity regime, the equilibrium configuration becomes unstable and bifurcates into multiple equilibrium positions. To investigate the vibrations that occur in the vicinity of a buckled equilibrium position, the pseudo-nonlinear vibration problem around the first buckled configuration is solved precisely using a new solution procedure. By solving the resulting eigenvalue problem, the natural frequencies and the associated mode shapes of the pipe are calculated. The dynamic stability of the post-buckling configurations obtained in this manner is investigated. The first buckled shape is a stable equilibrium position for all boundary conditions. The buckled configurations beyond the first buckling mode are unstable equilibrium positions. The natural frequencies of the lowest vibration modes around each of the first two buckled configurations are presented. Effects of the system parameters on pipe behavior as well as the possibility of a subcritical pitchfork bifurcation are also investigated. The results show that many internal resonances might be activated among the vibration modes around the same or different buckled configurations.
MARCUSE’S ONE-DIMENSIONAL SOCIETY IN ONE-DIMENSIONAL MAN
Directory of Open Access Journals (Sweden)
MILOS RASTOVIC
2013-05-01
Full Text Available Nowadays, Marcuse’s main book One-Dimensional Man is almost obsolete, or rather passé. However, there are reasons to renew the reading of his book because of “the crisis of capitalism,” and the prevailing framework of technological domination in “advanced industrial society” in which we live today. “The new forms of control” in “advanced industrial societies” have replaced traditional methods of political and economic administration. The dominant structural element of “advanced industrial society” has become a technical and scientific apparatus of production and distribution of technology and administrative practice based on application of impersonal rules by a hierarchy of associating authorities. Technology has been liberated from the control of particular interests, and it has become the factor of domination in itself. Technological domination stems from the technical development of the productive apparatus that reproduces its ability into all spheres of social life (cultural, political, and economic. Based upon this consideration, in this paper, I will examine Marcuse’s ideas of “the new forms of control,” which creates a one–dimensional society. Marcuse’s fundamental thesis in One-Dimensional Man is that technological rationality is the most dominant factor in an “advanced industrial society,” which unites two earlier opposing forces of dissent: the bourgeoisie and the proletariat.
The quasi-one-dimensional hyperbolic model of hydraulic fracturing
Directory of Open Access Journals (Sweden)
Aidar M. Il'yasov
2016-12-01
Full Text Available The paper describes a quasi-one-dimensional hyperbolic model of hydraulic fracture growth assuming for the hydraulic fracturing that stress intensity is much higher than fracture resistance. The mode under analysis, which accounts for convective and unsteady terms in the fluid flow equation, is a generalization of the Perkins–Kern–Nordgren local model. It has been proved that the obtained system of differential equations is a quasi-linear strictly hyperbolic system, for which the characteristics were found as well as their correlations. For the case of the Coriolis correction neglect, the Riemann invariants were found. Neglecting the injected fluid leak-off and viscosity, the Riemann waves, similar to simple plane waves in gas dynamics, were defined and their properties were studied. The evolutionism of fracture boundaries was investigated. The initial boundary value problem was set for fracture growth. It has been shown that the neglect of dissipative terms in the presented model allows constructing a simple wave theory analogous to the theory of one-dimensional gas dynamics for isentropic plane waves.
A review on ternary vanadate one-dimensional nanomaterials.
Pei, Li Z; Wang, Shuai; Liu, Han D; Pei, Yin Q
2014-01-01
Ternary vanadate one-dimensional nanomaterials exhibit great application potential in the fields of lithium ion batteries, photocatalysis and electrochemical sensors owing to their good electrochemical and photocatalytic properties. The article reviews the recent progress and patents on the vanadate one-dimensional nanomaterials. The synthesis of the vanadate nanorods, nanobelts and nanotubes by hydrothermal method, template method and room temperature wet chemical process is demonstrated. The application of the vanadate one-dimensional nanomaterials for lithium ion batteries, electrochemical sensors and photocatalysis is discussed. The possible development direction of the vanadate one-dimensional nanomaterials for the synthesis and application is also analyzed.
Explicit Solutions for One-Dimensional Mean-Field Games
Prazeres, Mariana
2017-04-05
In this thesis, we consider stationary one-dimensional mean-field games (MFGs) with or without congestion. Our aim is to understand the qualitative features of these games through the analysis of explicit solutions. We are particularly interested in MFGs with a nonmonotonic behavior, which corresponds to situations where agents tend to aggregate. First, we derive the MFG equations from control theory. Then, we compute explicit solutions using the current formulation and examine their behavior. Finally, we represent the solutions and analyze the results. This thesis main contributions are the following: First, we develop the current method to solve MFG explicitly. Second, we analyze in detail non-monotonic MFGs and discover new phenomena: non-uniqueness, discontinuous solutions, empty regions and unhappiness traps. Finally, we address several regularization procedures and examine the stability of MFGs.
Combustion synthesis of one-dimensional nanocrystalline silicon carbide
Energy Technology Data Exchange (ETDEWEB)
Soszynski, M.; Dabrowska, A.; Bystrzejewski, M.; Huczko, A. [Laboratory of Nanomaterials Physics and Chemistry, Department of Chemistry, Warsaw University, 1 Pasteur str., 02-093 Warsaw (Poland)
2010-12-15
Beta-SiC (cubic phase) nanowires (SiCNWs) have been grown spontaneously during the autothermal self-propagating high-temperature synthesis (SHS) from elemental silicon and poly(tetrafluoroethylene) (PTFE) powder mixtures in oxygen-enriched atmosphere. The combustion process was on-line monitored using high-speed photography in order to estimate the reaction processing time which was well below 1 s. From the emission spectroscopy the averaged combustion temperature was evaluated to be close to 2000 K. The products were characterized by wet chemical analysis, X-ray diffraction, scanning and transmission microscopy, and Raman spectroscopy. The raw products were processed by wet chemistry to obtain pure (above 90%) well-crystallized one-dimensional single crystals of SiCNWs. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
One-dimensional diffusion model in an Inhomogeneous region
CSIR Research Space (South Africa)
Fedotov, I
2006-01-01
Full Text Available A one-dimensional model is developed to describe atomic diffusion in a graphite tube atomizer for electrothermal atomic adsorption spectrometry. The underlying idea of the model is the solution of an inhomogeneous one-dimensional diffusion equation...
Short range correlations in a one dimensional electron gas
Tas, Murat; Tomak, Mehmet
2001-01-01
We use the SSTL (Singwi, Sjolander, Tosi, Land) approximation to investigate the short--range correlations in a one dimensional electron gas, for the first time. Although SSTL is introduced to better satisfy the compressibility sum rule in three dimensions, the widely used STLS (Singwi, Tosi, Land, Sjolander) approximation turns out to be more successful in the case of the one dimensional electron gas.
One dimensional Convolutional Goppa Codes over the projective line
Pérez, J A Domínguez; Sotelo, G Serrano
2011-01-01
We give a general method to construct MDS one-dimensional convolutional codes. Our method generalizes previous constructions of H. Gluesing-Luerssen and B. Langfeld. Moreover we give a classification of one-dimensional Convolutional Goppa Codes and propose a characterization of MDS codes of this type.
Plasma properties of quasi-one-dimensional ring
Shmelev, G M
2001-01-01
The plasma properties of the quasi-one-dimensional ring in the threshold cases of low and high frequencies, corresponding to the plasma oscillations and dielectric relaxation are studied within the frames of the classical approach. The plasma oscillations spectrum and the electron dielectric relaxation frequency in the quasi-one-dimensional ring are calculated. The plasmons spectrum equidistance is identified. It is shown , that in contrast to the three-dimensional case there takes place the dielectric relaxation dispersion, wherefrom there follows the possibility of studying the carriers distribution in the quasi-one-dimensional rings through the method of the dielectric relaxation spectroscopy
Simulating higher-dimensional geometries in GADRAS using approximate one-dimensional solutions.
Energy Technology Data Exchange (ETDEWEB)
Thoreson, Gregory G.; Mitchell, Dean J; Harding, Lee T.
2013-02-01
The Gamma Detector Response and Analysis Software (GADRAS) software package is capable of simulating the radiation transport physics for one-dimensional models. Spherical shells are naturally one-dimensional, and have been the focus of development and benchmarking. However, some objects are not spherical in shape, such as cylinders and boxes. These are not one-dimensional. Simulating the radiation transport in two or three dimensions is unattractive because of the extra computation time required. To maintain computational efficiency, higher-dimensional geometries require approximations to simulate them in one-dimension. This report summarizes the theory behind these approximations, tests the theory against other simulations, and compares the results to experimental data. Based on the results, it is recommended that GADRAS users always attempt to approximate reality using spherical shells. However, if fissile material is present, it is imperative that the shape of the one-dimensional model matches the fissile material, including the use of slab and cylinder geometry.
Applying one-dimensional fluid thermal elements into a 3D CLIC accelerating strucutre
Raatikainen, Riku; Österberg, Kenneth; Riddone, Germana; Samoshkin, Alexander; Gudkov, Dmitry
2010-01-01
A finite element modeling method to simplify the analysis of coupled thermal-structural model for the CLIC accelerating structure is presented. In addition, the results of thermal and structural analyses for the accelerating structure are presented. Instead of using a standard 3D computational fluid dynamics (CFD) method for solving problems involving fluid dynamics and heat transfer in 3D environment, one-dimensional fluid thermal elements are used. In one-dimensional flow, the governing equations of fluid dynamics are considerably simplified. Thus, it is expected that the computational time for more complex simulations becomes shorter. The method was first applied to several test models, which demonstrated the suitability of the one-dimensional flow modeling. The results show that one-dimensional fluid flow reduces the computation time considerably allowing the modeling for the future larger assemblies with sufficient accuracy.
Dipolar Interaction in a One-Dimensional Ising Ring
Directory of Open Access Journals (Sweden)
Gina Rose Tongco
2004-12-01
Full Text Available As synthesis of low-dimensional magnetic systems become possible, the need for theoretical understanding of their behavior arises. In this work, the authors explore a one-dimensional magnetic structure with the spins having dipolar interaction.
One-Dimensional Tunable Photonic-Crystal IR Filter Project
National Aeronautics and Space Administration — MetroLaser proposes to design and develop an innovative narrowband tunable IR filter based on the properties of a one-dimensional photonic crystal structure with a...
Negative differential resistance in a one-dimensional molecular wire ...
Indian Academy of Sciences (India)
voltage characteristics of a one-dimensional molecular wire with odd number of atoms. The wire has been modelled ... Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore 560 064, India ...
One-Dimensional Model of the Pulsar Accelerator
TSUKAMOTO, Kaoru; SHIBATA, Shinpei
1991-01-01
We construct an one-dimensional model of the accelerating region of the pulsar magnetosphere. The pair-creation-limited voltage of accelerator is obtained as fanctions of the location of the accelerator.
One dimensional models of excitons in carbon nanotubes
DEFF Research Database (Denmark)
Cornean, Horia Decebal; Duclos, P.; Pedersen, Thomas Garm
Excitons in carbon nanotubes may be modeled by two oppositely charged particles living on the surface of a cylinder. We derive three one dimensional effective Hamiltonians which become exact as the radius of the cylinder vanishes. Two of them are solvable.......Excitons in carbon nanotubes may be modeled by two oppositely charged particles living on the surface of a cylinder. We derive three one dimensional effective Hamiltonians which become exact as the radius of the cylinder vanishes. Two of them are solvable....
Rhodes, Kirsty M; Turner, Rebecca M; White, Ian R; Jackson, Dan; Spiegelhalter, David J; Higgins, Julian P T
2016-12-20
Many meta-analyses combine results from only a small number of studies, a situation in which the between-study variance is imprecisely estimated when standard methods are applied. Bayesian meta-analysis allows incorporation of external evidence on heterogeneity, providing the potential for more robust inference on the effect size of interest. We present a method for performing Bayesian meta-analysis using data augmentation, in which we represent an informative conjugate prior for between-study variance by pseudo data and use meta-regression for estimation. To assist in this, we derive predictive inverse-gamma distributions for the between-study variance expected in future meta-analyses. These may serve as priors for heterogeneity in new meta-analyses. In a simulation study, we compare approximate Bayesian methods using meta-regression and pseudo data against fully Bayesian approaches based on importance sampling techniques and Markov chain Monte Carlo (MCMC). We compare the frequentist properties of these Bayesian methods with those of the commonly used frequentist DerSimonian and Laird procedure. The method is implemented in standard statistical software and provides a less complex alternative to standard MCMC approaches. An importance sampling approach produces almost identical results to standard MCMC approaches, and results obtained through meta-regression and pseudo data are very similar. On average, data augmentation provides closer results to MCMC, if implemented using restricted maximum likelihood estimation rather than DerSimonian and Laird or maximum likelihood estimation. The methods are applied to real datasets, and an extension to network meta-analysis is described. The proposed method facilitates Bayesian meta-analysis in a way that is accessible to applied researchers. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.
One-dimensional extended Hubbard model in the atomic limit.
Mancini, F; Mancini, F P
2008-06-01
We present the exact solution of the one-dimensional extended Hubbard model in the atomic limit within the Green's function and equations of motion formalism. We provide a comprehensive and systematic analysis of the model by considering all the relevant response and correlation functions as well as thermodynamic quantities in the whole parameters space. At zero temperature we identify four phases in the plane (U,n) ( U is the on-site potential and n is the filling) and relative phase transitions as well as different types of charge ordering. These features are endorsed by investigating at T=0 the chemical potential and pertinent local correlators, the particle and double occupancy correlation functions, the entropy, and by studying the behavior in the limit T-->0 of the charge and spin susceptibilities. A detailed study of the thermodynamic quantities is also presented at finite temperature. This study evidences that a finite-range order persists for a wide range of the temperature, as shown by the behavior of the correlation functions and by the two-peak structure exhibited by the charge susceptibility and by the entropy. Moreover, the equations of motion formalism, together with the use of composite operators, allows us to exactly determine the set of elementary excitations. As a result, the density of states can be determined and a detailed analysis of the specific heat allows for identifying the excitations and for ascribing its two-peak structure to a redistribution of the charge density.
Chiral spin condensation in a one-dimensional optical lattice
Wu, Ying-Hai; Li, Xiaopeng; Das Sarma, S.
2017-12-01
We study a spinor (two-component) Bose gas confined in a one-dimensional double-valley optical lattice which has a double-well structure in momentum space. Based on field theory analysis, it is found that spinor bosons in the double-valley band may form a spin-charge mixed chiral spin quasicondensate under certain conditions. Our numerical calculations in a concrete π -flux triangular ladder system confirm the robustness of the chiral spin order against interactions and quantum fluctuations. This exotic atomic Bose-Einstein condensate exhibits spatially staggered spin loop currents without any charge dynamics despite the complete absence of spin-orbit coupling in the system, creating an interesting approach to atom spintronics. The entanglement entropy scaling allows us to extract conformal-field-theory central charge and establish the low-energy effective field theory for the chiral spin condensate as a two-component Luttinger liquid. Our predictions should be detectable in atomic experiments through spin-resolved time-of-flight techniques.
Numerical method of characteristics for one-dimensional blood flow
Acosta, Sebastian; Puelz, Charles; Rivière, Béatrice; Penny, Daniel J.; Rusin, Craig G.
2015-08-01
Mathematical modeling at the level of the full cardiovascular system requires the numerical approximation of solutions to a one-dimensional nonlinear hyperbolic system describing flow in a single vessel. This model is often simulated by computationally intensive methods like finite elements and discontinuous Galerkin, while some recent applications require more efficient approaches (e.g. for real-time clinical decision support, phenomena occurring over multiple cardiac cycles, iterative solutions to optimization/inverse problems, and uncertainty quantification). Further, the high speed of pressure waves in blood vessels greatly restricts the time step needed for stability in explicit schemes. We address both cost and stability by presenting an efficient and unconditionally stable method for approximating solutions to diagonal nonlinear hyperbolic systems. Theoretical analysis of the algorithm is given along with a comparison of our method to a discontinuous Galerkin implementation. Lastly, we demonstrate the utility of the proposed method by implementing it on small and large arterial networks of vessels whose elastic and geometrical parameters are physiologically relevant.
Controllable acoustic rectification in one-dimensional piezoelectric composite plates
Zou, Xin-Ye; Liang, Bin; Yuan, Ying; Zhu, Xue-Feng; Cheng, Jian-Chun
2013-10-01
Theoretical studies are presented for the band structures and power transmission spectra for both symmetric and asymmetric Lamb wave modes in a one-dimensional piezoelectric composite plate consisting of piezoelectric ceramics placed periodically in epoxy by the plane wave expansion method and the harmonic response analysis method, respectively. The one-way transmission, two-way transmission, and two-way forbidden models of acoustic rectification for Lamb waves can be established in specific frequency ranges by introducing corresponding modes conversion and selection mechanisms, and the steady-state displacement fields of these models are also calculated for the proposed plate. The numerical results show that the power extinction ratio for one-way transmission model is up to 104. The piezoelectric composite plate can be switched between these models rapidly and efficiently only by applying the open-circuit and short-circuit electric boundary conditions antisymmetrically or symmetrically on the piezoelectric ceramic unit's boundaries instead of changing any geometrical structure, and the composite plate's architecture structure is also simple enough for the on-chip integration in the engineering field.
One-dimensional rainbow technique using Fourier domain filtering.
Wu, Yingchun; Promvongsa, Jantarat; Wu, Xuecheng; Cen, Kefa; Grehan, Gerard; Saengkaew, Sawitree
2015-11-16
Rainbow refractometry can measure the refractive index and the size of a droplet simultaneously. The refractive index measurement is extracted from the absolute rainbow scattering angle. Accordingly, the angular calibration is vital for accurate measurements. A new optical design of the one-dimensional rainbow technique is proposed by using a one-dimensional spatial filter in the Fourier domain. The relationship between the scattering angle and the CCD pixel of a recorded rainbow image can be accurately determined by a simple calibration. Moreover, only the light perpendicularly incident on the lens in the angle (φ) direction is selected, which exactly matches the classical inversion algorithm used in rainbow refractometry. Both standard and global one-dimensional rainbow techniques are implemented with the proposed optical design, and are successfully applied to measure the refractive index and the size of a line of n-heptane droplets.
A review on one dimensional perovskite nanocrystals for piezoelectric applications
Directory of Open Access Journals (Sweden)
Li-Qian Cheng
2016-03-01
Full Text Available In recent years, one-dimensional piezoelectric nanomaterials have become a research topic of interest because of their special morphology and excellent piezoelectric properties. This article presents a short review on one dimensional perovskite piezoelectric materials in different systems including Pb(Zr,TiO3, BaTiO3 and (K,NaNbO3 (KNN. We emphasize KNN as a promising lead-free piezoelectric compound with a high Curie temperature and high piezoelectric properties and describe its synthesis and characterization. In particular, details are presented for nanoscale piezoelectricity characterization of a single KNN nanocrystal by piezoresponse force microscopy. Finally, this review describes recent progress in applications based on one dimensional piezoelectric nanostructures with a focus on energy harvesting composite materials.
How good are one-dimensional Josephson junction models?
DEFF Research Database (Denmark)
Lomdahl, P. S.; Olsen, O.H.; Eilbeck, J. C.
1985-01-01
A two-dimensional model of Josephson junctions of overlap type is presented and shown to reduce to the usual one-dimensional (1D) model in the limit of a very narrow junction. Comparisons between the stability limits for fluxon reflection obtained from the two models suggest that the many results...... obtained from the one-dimensional model can be used for large-area junctions, thus explaining the remarkable agreement between 1D theory and experiments. Journal of Applied Physics is copyrighted by The American Institute of Physics....
One-dimensional models of excitons in carbon nanotubes
DEFF Research Database (Denmark)
Cornean, Horia Decebal; Duclos, Pierre; Pedersen, Thomas Garm
2004-01-01
Excitons in carbon nanotubes may be modeled by two oppositely charged particles living on the surface of a cylinder. We derive three one-dimensional effective Hamiltonians which become exact as the radius of the cylinder vanishes. Two of them are solvable.......Excitons in carbon nanotubes may be modeled by two oppositely charged particles living on the surface of a cylinder. We derive three one-dimensional effective Hamiltonians which become exact as the radius of the cylinder vanishes. Two of them are solvable....
Viscous Dissipation in One-Dimensional Quantum Liquids
Matveev, K. A.; Pustilnik, M.
2017-07-01
We develop a theory of viscous dissipation in one-dimensional single-component quantum liquids at low temperatures. Such liquids are characterized by a single viscosity coefficient, the bulk viscosity. We show that for a generic interaction between the constituent particles this viscosity diverges in the zero-temperature limit. In the special case of integrable models, the viscosity is infinite at any temperature, which can be interpreted as a breakdown of the hydrodynamic description. Our consideration is applicable to all single-component Galilean-invariant one-dimensional quantum liquids, regardless of the statistics of the constituent particles and the interaction strength.
Quantum restoration of broken symmetry in one-dimensional loop ...
Indian Academy of Sciences (India)
Home; Journals; Pramana – Journal of Physics; Volume 82; Issue 6. Quantum restoration of broken symmetry in onedimensional loop space. Pinaki Patra ... For one-dimensional loop space, a nonlinear nonlocal transformation of fields is given to make the action of the self-interacting quantum field to the free one. A specific ...
The one-dimensional extended Bose–Hubbard model
Indian Academy of Sciences (India)
Unknown
We use the finite-size, density-matrix-renormalization-group (DMRG) ... excitations; other topics in quantum fluids and solids; liquid and solid helium. ..... 3. Conclusions. In conclusion, then, we have studied the complete phase diagram of the one-dimensional, extended Bose–Hubbard model for mean boson density ρ= 1 by ...
Strategies in localization proofs for one-dimensional random ...
Indian Academy of Sciences (India)
Recent results on localization, both exponential and dynamical, for various models of one-dimensional, continuum, random Schrödinger operators are reviewed. This includes Anderson models with indefinite single site potentials, the Bernoulli–Anderson model, the Poisson model, and the random displacement model.
One-dimensional spatially dependent solute transport in semi ...
African Journals Online (AJOL)
The present study is an attempt to describe analytical solution of spatially dependent solute transport in one-dimensional semiinfinite homogeneous porous domain. In this mathematical model the dispersion coefficient is considered spatially dependent while seepage velocity is considered exponentially decreasing function ...
One-dimensional spatially dependent solute transport in semi ...
African Journals Online (AJOL)
The present study is an attempt to describe analytical solution of spatially dependent solute transport in one-dimensional semi- infinite homogeneous porous domain. In this mathematical model the dispersion coefficient is considered spatially dependent while seepage velocity is considered exponentially decreasing ...
One-dimensional unsteady solute transport along unsteady flow ...
Indian Academy of Sciences (India)
The one-dimensional linear advection–diffusion equation is solved analytically by using the Laplace integral transform. The solute transport as well as the flow field is considered to be unsteady, both of independent patterns. The solute dispersion occurs through an inhomogeneous semi-infinite medium. Hence, velocity is ...
Synthesis and magnetic properties of one-dimensional metal ...
Indian Academy of Sciences (India)
Unknown
Molecular-based magnets; magnetic properties; one-dimensional metal oxalate; synthesis and structure of metal-oxalates. 1. Introduction. Synthesis and characterization of the polymetallic com- plexes with a goal to report molecular ferromagnets have been subject of numerous studies in recent years. (Miller et al 1986, ...
Analytical solutions of one-dimensional advection–diffusion ...
Indian Academy of Sciences (India)
Analytical solutions are obtained for one-dimensional advection –diffusion equation with variable coefficients in a longitudinal ﬁnite initially solute free domain,for two dispersion problems.In the ﬁrst one,temporally dependent solute dispersion along uniform ﬂow in homogeneous domain is studied.In the second problem the ...
Electron Rydberg wave packets in one-dimensional atoms
Indian Academy of Sciences (India)
An expression for the transition probability or form factor in one-dimensional Rydberg atom irradiated by short half-cycle pulse was constructed. In applicative contexts, our expression was found to be more useful than the corresponding result given by Landau and Lifshitz. Using the new expression for the form factor, the ...
Forecasting In One-Dimensional And Generalized Integrated ...
African Journals Online (AJOL)
In this paper, forecast of one-dimensional integrated autoregressive bilinear is compared with forecast of generalized integrated autoregressive bilinear model. We describe the method for estimation of these models and the forecast. It is also pointed out that for this class of non-linear time series models; it is possible to ...
Electron Rydberg wave packets in one-dimensional atoms
Indian Academy of Sciences (India)
B TALUKDAR∗. Department of Physics, Visva-Bharati University, Santiniketan 731 235, India. ∗Corresponding author. E-mail: binoy123@bsnl.in. MS received 20 September 2009; revised 19 February 2010; accepted 6 April 2010. Abstract. An expression for the transition probability or form factor in one-dimensional.
Monte Carlo investigation of the one-dimensional Potts model
Energy Technology Data Exchange (ETDEWEB)
Karma, A.S.; Nolan, M.J.
1983-02-01
Monte Carlo results are presented for a variety of one-dimensional dynamical q-state Potts models. Our calculations confirm the expected universal value z = 2 for the dynamic scaling exponent. Our results also indicate that an increase in q at fixed correlation length drives the dynamics into the scaling regime.
Synthesis and magnetic properties of one-dimensional metal ...
Indian Academy of Sciences (India)
Keywords. Molecular-based magnets; magnetic properties; one-dimensional metal oxalate; synthesis and structure of metal-oxalates. ... On lowering the temperature, the effective magnetic moment decreases gradually and is indicative of antiferromagnetic phase transition. The complexes have also been characterized by ...
Numerical solution of the one-dimensional Burgers' equation ...
Indian Academy of Sciences (India)
Numerical solution of the one-dimensional Burgers' equation: Implicit and fully implicit exponential finite difference methods ... Research Articles Volume 81 Issue 4 October 2013 pp 547-556 ... This paper describes two new techniques which give improved exponential finite difference solutions of Burgers' equation.
Bound states of Dipolar Bosons in One-dimensional Systems
DEFF Research Database (Denmark)
G. Volosniev, A.; R. Armstrong, J.; V. Fedorov, D.
2013-01-01
We consider one-dimensional tubes containing bosonic polar molecules. The long-range dipole-dipole interactions act both within a single tube and between different tubes. We consider arbitrary values of the externally aligned dipole moments with respect to the symmetry axis of the tubes. The few-...
One-Dimensional Ising Model with "k"-Spin Interactions
Fan, Yale
2011-01-01
We examine a generalization of the one-dimensional Ising model involving interactions among neighbourhoods of "k" adjacent spins. The model is solved by exploiting a connection to an interesting computational problem that we call ""k"-SAT on a ring", and is shown to be equivalent to the nearest-neighbour Ising model in the absence of an external…
SIMPLE ONE-DIMENSIONAL TRANSPORT CODE FOR MAGNETIZED TARGET FUSION
Energy Technology Data Exchange (ETDEWEB)
STEFANO MIGLUIOLO - MIT
1999-10-30
A one-dimensional (in space) time-dependent simulation code is development to study the transport of energy and particles in a field reversed configuration (FRC) plasma that is undergoing radial contraction. This contraction is due to an imploding metallic liner, which is treated through a boundary condition.
Negative differential resistance in a one-dimensional molecular wire ...
Indian Academy of Sciences (India)
differential resistance (NDR) at some critical bias, due to the degeneracy in the energies of the frontier molecular orbitals. The presence of ... Negative differential resistance in a one-dimensional molecular wire above Hamiltonian with the .... observed in many organic systems. Some of the explanations proposed in literature.
Transport through a Finite One-Dimensional Crystal
Kouwenhoven, L.P.; Hekking, F.W.J.; Wees, B.J. van; Harmans, C.J.P.M.; Timmering, C.E.; Foxon, C.T.
1990-01-01
We have studied the magnetotransport properties of an artificial one-dimensional crystal. The crystal consists of a sequence of fifteen quantum dots, defined in the two-dimensional electron gas of a GaAs/AlGaAs heterostructure by means of a split-gate technique. At a fixed magnetic field of 2 T, two
Localization of Electrons in a One-Dimensional Disordered Crystal ...
African Journals Online (AJOL)
Localization of electrons in a one-dimensional disorder crystal and suppression of conduction were investigated in the research work. These were achieved by modeling the disorders within the crystal lattice with random potential barriers. The transmission coefficients of the electron (non-interacting electron) in the random ...
Current-Voltage Characteristics of Quasi-One-Dimensional Superconductors
DEFF Research Database (Denmark)
Vodolazov, D.Y.; Peeters, F.M.; Piraux, L.
2003-01-01
The current-voltage (I-V) characteristics of quasi-one-dimensional superconductors were discussed. The I-V characteristics exhibited an unusual S behavior. The dynamics of superconducting condensate and the existence of two different critical currents resulted in such an unusual behavior....
Strategies in localization proofs for one-dimensional random ...
Indian Academy of Sciences (India)
R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22
Strategies in localization proofs for one-dimensional random. Schrödinger operators. G ¨UNTER STOLZ. Department of Mathematics, University of Alabama at Birmingham, Birmingham, AL. 35294-1170, USA. E-mail: stolz@math.uab.edu. Abstract. Recent results on localization, both exponential and dynamical, for various.
Continuous quantum phase transitions in the one-dimensional spin ...
Indian Academy of Sciences (India)
E-mail: adegoke@rushpost.com; adegoke@daad-alumni.de. MS received 25 January 2009; accepted 24 September 2009. Abstract. We have investigated the one-dimensional spin-1/2 axial next-nearest- neighbour Ising (ANNNI) model in two orthogonal magnetic fields at zero temperature. There are four different possible ...
Fractal spectra in generalized Fibonacci one-dimensional magnonic quasicrystals
Energy Technology Data Exchange (ETDEWEB)
Costa, C.H.O. [Departamento de Fisica Teorica e Experimental, Universidade Federal do Rio grande do Norte, 59072-970 Natal-RN (Brazil); Vasconcelos, M.S., E-mail: manoelvasconcelos@yahoo.com.br [Escola de Ciencias e Tecnologia, Universidade Federal do Rio grande do Norte, 59072-970 Natal-RN (Brazil); Barbosa, P.H.R.; Barbosa Filho, F.F. [Departamento de Fisica, Universidade Federal do Piaui, 64049-550 Teresina-Pi (Brazil)
2012-07-15
In this work we carry out a theoretical analysis of the spectra of magnons in quasiperiodic magnonic crystals arranged in accordance with generalized Fibonacci sequences in the exchange regime, by using a model based on a transfer-matrix method together random-phase approximation (RPA). The generalized Fibonacci sequences are characterized by an irrational parameter {sigma}(p,q), which rules the physical properties of the system. We discussed the magnonic fractal spectra for first three generalizations, i.e., silver, bronze and nickel mean. By varying the generation number, we have found that the fragmentation process of allowed bands makes possible the emergence of new allowed magnonic bulk bands in spectra regions that were magnonic band gaps before, such as which occurs in doped semiconductor devices. This interesting property arises in one-dimensional magnonic quasicrystals fabricated in accordance to quasiperiodic sequences, without the need to introduce some deferent atomic layer or defect in the system. We also make a qualitative and quantitative investigations on these magnonic spectra by analyzing the distribution and magnitude of allowed bulk bands in function of the generalized Fibonacci number F{sub n} and as well as how they scale as a function of the number of generations of the sequences, respectively. - Highlights: Black-Right-Pointing-Pointer Quasiperiodic magnonic crystals are arranged in accordance with the generalized Fibonacci sequence. Black-Right-Pointing-Pointer Heisenberg model in exchange regime is applied. Black-Right-Pointing-Pointer We use a theoretical model based on a transfer-matrix method together random-phase approximation. Black-Right-Pointing-Pointer Fractal spectra are characterized. Black-Right-Pointing-Pointer We analyze the distribution of allowed bulk bands in function of the generalized Fibonacci number.
On pseudo-values for regression analysis in competing risks models
DEFF Research Database (Denmark)
Graw, F; Gerds, Thomas Alexander; Schumacher, M
2009-01-01
For regression on state and transition probabilities in multi-state models Andersen et al. (Biometrika 90:15-27, 2003) propose a technique based on jackknife pseudo-values. In this article we analyze the pseudo-values suggested for competing risks models and prove some conjectures regarding...
Quasi-One-Dimensional Intermittent Flux Behavior in Superconducting Films
Directory of Open Access Journals (Sweden)
A. J. Qviller
2012-01-01
Full Text Available Intermittent filamentary dynamics of the vortex matter in superconductors is found in films of YBa_{2}Cu_{3}O_{7-δ} deposited on tilted substrates. Deposition of this material on such substrates creates parallel channels of easy flux penetration when a magnetic field is applied perpendicular to the film. As the applied field is gradually increased, magneto-optical imaging reveals that flux penetrates via numerous quasi-one-dimensional jumps. The distribution of flux avalanche sizes follows a power law, and data collapse is obtained by finite-size scaling, with the depth of the flux front used as crossover length. The intermittent behavior shows no threshold value in the applied field, in contrast to conventional flux jumping. The results strongly suggest that the quasi-one-dimensional flux jumps are of a different nature than the thermomagnetic dendritic (branching avalanches that are commonly found in superconducting films.
One-Dimensional Fluids with Second Nearest-Neighbor Interactions
Fantoni, Riccardo; Santos, Andrés
2017-12-01
As is well known, one-dimensional systems with interactions restricted to first nearest neighbors admit a full analytically exact statistical-mechanical solution. This is essentially due to the fact that the knowledge of the first nearest-neighbor probability distribution function, p_1(r), is enough to determine the structural and thermodynamic properties of the system. On the other hand, if the interaction between second nearest-neighbor particles is turned on, the analytically exact solution is lost. Not only the knowledge of p_1(r) is not sufficient anymore, but even its determination becomes a complex many-body problem. In this work we systematically explore different approximate solutions for one-dimensional second nearest-neighbor fluid models. We apply those approximations to the square-well and the attractive two-step pair potentials and compare them with Monte Carlo simulations, finding an excellent agreement.
Synthesis and characterization of one-dimensional titanate structure
Directory of Open Access Journals (Sweden)
Ljubica M. Nikolić
2008-12-01
Full Text Available One-dimensional titania structures were synthesized trough a simple hydrothermal process in a highly alkaline conditions. The aim of this work was to elucidate the effect of time on the formation of 1D titanates as well on its structural characteristics (morphology, phase composition, surface area. Apart from that, the effect of heat treatment conditions on the stability of titanate based 1D samples has been investigated. The results have revealed that it is possible to form one-dimensional titanates already after 1 hour of hydrothermal synthesis. Although the composition of titanates is still under debate, the results probably correspond to the layered sodium titanates. The 1D prepared structures show a remarkable stability during heating, remaining the basic morphology and composition even up to 700°C.
Quasi-one-dimensional intermittent flux behavior in superconducting films
DEFF Research Database (Denmark)
Qviller, A. J.; Yurchenko, V. V.; Galperin, Y. M.
2012-01-01
Intermittent filamentary dynamics of the vortex matter in superconductors is found in films of YBa2Cu3O7-δ deposited on tilted substrates. Deposition of this material on such substrates creates parallel channels of easy flux penetration when a magnetic field is applied perpendicular to the film....... As the applied field is gradually increased, magneto-optical imaging reveals that flux penetrates via numerous quasi-one-dimensional jumps. The distribution of flux avalanche sizes follows a power law, and data collapse is obtained by finite-size scaling, with the depth of the flux front used as crossover length....... The intermittent behavior shows no threshold value in the applied field, in contrast to conventional flux jumping. The results strongly suggest that the quasi-one-dimensional flux jumps are of a different nature than the thermomagnetic dendritic (branching) avalanches that are commonly found in superconducting...
Resonance Raman spectroscopy in one-dimensional carbon materials
Directory of Open Access Journals (Sweden)
Dresselhaus Mildred S.
2006-01-01
Full Text Available Brazil has played an important role in the development and use of resonance Raman spectroscopy as a powerful characterization tool for materials science. Here we present a short history of Raman scattering research in Brazil, highlighting the important contributions to the field coming from Brazilian researchers in the past. Next we discuss recent and important contributions where Brazil has become a worldwide leader, that is on the physics of quasi-one dimensional carbon nanotubes. We conclude this article by presenting results from a very recent resonance Raman study of exciting new materials, that are strictly one-dimensional carbon chains formed by the heat treatment of very pure double-wall carbon nanotube samples.
True Bilayer Exciton Condensate of One-Dimensional Electrons.
Kantian, A; Abergel, D S L
2017-07-21
We theoretically predict that a true bilayer exciton condensate, characterized by off-diagonal long-range order and global phase coherence, can be created in one-dimensional solid state electron systems. The mechanism by which this happens is to introduce a single particle hybridization of electron and hole populations, which locks the phase of the relevant mode and hence invalidates the Mermin-Wagner theorem. Electron-hole interactions then amplify this tendency towards off-diagonal long-range order, enhancing the condensate properties by more than an order of magnitude over the noninteracting limit. We show that the temperatures below which a substantial condensate fraction would form could reach hundreds of Kelvin, a benefit of the weak screening in one-dimensional systems.
Chaotic macroscopic phases in one-dimensional oscillators
Politi, Antonio; Pikovsky, Arkady; Ullner, Ekkehard
2017-06-01
The connection between the macroscopic description of collective chaos and the underlying microscopic dynamics is thoroughly analysed in mean-field models of one-dimensional oscillators. We investigate to what extent infinitesimal perturbations of the microscopic configurations can provide information also on the stability of the corresponding macroscopic phase. In ensembles of identical one-dimensional dynamical units, it is possible to represent the microscopic configurations so as to make transparent their connection with the macroscopic world. As a result, we find evidence of an intermediate, mesoscopic, range of distances, over which the instability is neither controlled by the microscopic equations nor by the macroscopic ones. We examine a whole series of indicators, ranging from the usual microscopic Lyapunov exponents, to the collective ones, including finite-amplitude exponents. A system of pulse-coupled oscillators is also briefly reviewed as an example of non-identical phase oscillators where collective chaos spontaneously emerges.
Hidden Symmetry from Supersymmetry in One-Dimensional Quantum Mechanics
Directory of Open Access Journals (Sweden)
Alexander A. Andrianov
2009-06-01
Full Text Available When several inequivalent supercharges form a closed superalgebra in Quantum Mechanics it entails the appearance of hidden symmetries of a Super-Hamiltonian. We examine this problem in one-dimensional QM for the case of periodic potentials and potentials with finite number of bound states. After the survey of the results existing in the subject the algebraic and analytic properties of hidden-symmetry differential operators are rigorously elaborated in the Theorems and illuminated by several examples.
Molecular Self-Assembly into One-Dimensional Nanostructures
Palmer, Liam C.; Stupp, Samuel I.
2008-01-01
Self-assembly of small molecules into one-dimensional nanostructures offers many potential applications in electronically and biologically active materials. The recent advances discussed in this Account demonstrate how researchers can use the fundamental principles of supramolecular chemistry to craft the size, shape, and internal structure of nanoscale objects. In each system described here, we used atomic force microscopy (AFM) and transmission electron microscopy (TEM) to study the assembl...
Spreadsheet solutions of the one-dimensional cutting stock problem
Gajewski Robert
2017-01-01
The cutting stock problem encompasses cutting parts available in stock, which are called objects, to produce in specified quantities smaller pieces which are called items and optimizing an objective function. The cutting stock problem is common for many industrial processes – steel, paper tube and construction industries. One of the most important phases in solution of the one-dimensional cutting stock problem is a pattern generating procedure which can be performed in a spreadsheet.
Spreadsheet solutions of the one-dimensional cutting stock problem
Directory of Open Access Journals (Sweden)
Gajewski Robert
2017-01-01
Full Text Available The cutting stock problem encompasses cutting parts available in stock, which are called objects, to produce in specified quantities smaller pieces which are called items and optimizing an objective function. The cutting stock problem is common for many industrial processes – steel, paper tube and construction industries. One of the most important phases in solution of the one-dimensional cutting stock problem is a pattern generating procedure which can be performed in a spreadsheet.
Impurity states in the one-dimensional Bose gas
Pastukhov, Volodymyr
2017-10-01
The detailed study of the low-energy spectrum for a mobile impurity in the one-dimensional bosonic environment is performed. Particularly we have considered only two analytically accessible limits, namely, the case of an impurity immersed in a dilute Bose gas where one can use many-body perturbative techniques for low-dimensional bosonic systems and the case of the Tonks-Girardeau gas for which the usual fermionic diagrammatic expansion up to the second order is applied.
ONE-DIMENSIONAL AND TWO-DIMENSIONAL LEADERSHIP STYLES
Nikola Stefanović
2007-01-01
In order to motivate their group members to perform certain tasks, leaders use different leadership styles. These styles are based on leaders' backgrounds, knowledge, values, experiences, and expectations. The one-dimensional styles, used by many world leaders, are autocratic and democratic styles. These styles lie on the two opposite sides of the leadership spectrum. In order to precisely define the leadership styles on the spectrum between the autocratic leadership style and the democratic ...
Crossover from reptation to Rouse dynamics in a one-dimensional model.
Drzewiński, Andrzej; van Leeuwen, J M J
2006-06-01
A simple one-dimensional model is constructed for polymer motion. It exhibits the crossover from reptation to Rouse dynamics through gradually allowing hernia creation and annihilation. The model is treated by the density matrix technique which permits an accurate finite-size-scaling analysis of the behavior of long polymers.
Absolute and convective instabilities in a one-dimensional Brusselator flow model
DEFF Research Database (Denmark)
Kuznetsov, S.P.; Mosekilde, Erik; Dewel, G.
1997-01-01
The paper considers a one-dimensional Brusselator model with a uniform flow of the mixture of reaction components. An absolute as well as a convective instability can arise for both the Hopf and the Turing modes. The corresponding linear stability analysis is presented and supported by the result...
Critical exponents in the transition to chaos in one-dimensional ...
Indian Academy of Sciences (India)
We report the numerically evaluated critical exponents associated with the scaling of generalized fractal dimensions during the transition from order to chaos. The analysis is carried out in detail in the context of unimodal and bimodal maps representing typical one-dimensional discrete dynamical systems. The behavior of ...
Gravitational anomalies and one dimensional behaviour of black holes
Majhi, Bibhas Ranjan
2015-01-01
It has been pointed out by Bekenstein and Mayo that the behavior of the Black hole's entropy or information flow is similar to that through one-dimensional channel. Here I analyse the same issue with the use of gravitational anomalies. The rate of the entropy change ($\\dot{S}$) and the power ($P$) of the Hawking emission are calculated from the relevant components of the anomalous stress-tensor under the Unruh vacuum condition. I show that the dependence of $\\dot{S}$ on power is $\\dot{S}\\propto P^{1/2}$ which is identical to that for the information flow in one dimensional system. This is established by using the ($1+1$) dimensional gravitational anomalies first. Then the fact is further bolstered by considering the ($1+3$) dimensional gravitational anomalies. It is found that in the former case, the proportionality constant is exactly identical to one dimensional situation, known as Pendry's formula, while in later situation its value decreases.
Dias, Nuno Costa; Jorge, Cristina; Prata, João Nuno
2016-04-01
Using an extension of the Hörmander product of distributions, we obtain an intrinsic formulation of one-dimensional Schrödinger operators with singular potentials. This formulation is entirely defined in terms of standard Schwartz distributions and does not require (as some previous approaches) the use of more general distributions or generalized functions. We determine, in the new formulation, the action and domain of the Schrödinger operators with arbitrary singular boundary potentials. We also consider the inverse problem, and obtain a general procedure for constructing the singular (pseudo) potential that imposes a specific set of (local) boundary conditions. This procedure is used to determine the boundary operators for the complete four-parameter family of one-dimensional Schrödinger operators with a point interaction. Finally, the δ and δ‧ potentials are studied in detail, and the corresponding Schrödinger operators are shown to coincide with the norm resolvent limit of specific sequences of Schrödinger operators with regular potentials.
Connectivity analysis of one-dimensional ad-hoc networks
DEFF Research Database (Denmark)
Hansen, Martin Bøgsted; Rasmussen, Jakob Gulddahl; Schwefel, Hans-Peter
Applications and communication protocols in dynamic ad-hoc networks are exposed to physical limitations imposed by the connectivity relations that result from mobility. Motivated by vehicular freeway scenarios, this paper analyzes a number of important connectivity metrics for instantaneous...... snapshots of stochastic geographic movement patterns under the assumption of a fixed radio range for each node: (1) The node degree, corresponding to the number of single-hop neighbors of a mobile node; (2) The connectivity number, expressing the number of nodes reachable via multi-hop paths of arbitrary...
Linearized analysis of one-dimensional magnetohydrodynamic flows
Gundersen, Roy M
1964-01-01
Magnetohydrodynamics is concerned with the motion of electrically conducting fluids in the presence of electric or magnetic fields. Un fortunately, the subject has a rather poorly developed experimental basis and because of the difficulties inherent in carrying out controlled laboratory experiments, the theoretical developments, in large measure, have been concerned with finding solutions to rather idealized problems. This lack of experimental basis need not become, however, a multi megohm impedance in the line of progress in the development of a satisfactory scientific theory. While it is true that ultimately a scientific theory must agree with and, in actuality, predict physical phenomena with a reasonable degree of accuracy, such a theory must be sanctioned by its mathematical validity and consistency. Physical phenomena may be expressed precisely and quite comprehensively through the use of differential equations, and the equations formulated by LUNDQUIST and discussed by FRIEDRICHS belong to a class ...
Restricted feedback control of one-dimensional maps
Hall, Kevin; Christini, David J.
2001-04-01
Dynamical control of biological systems is often restricted by the practical constraint of unidirectional parameter perturbations. We show that such a restriction introduces surprising complexity to the stability of one-dimensional map systems and can actually improve controllability. We present experimental cardiac control results that support these analyses. Finally, we develop new control algorithms that exploit the structure of the restricted-control stability zones to automatically adapt the control feedback parameter and thereby achieve improved robustness to noise and drifting system parameters.
Quantum quenches and thermalization in one-dimensional systems
Rigol, Marcos
2010-03-01
We use quantum quenches to study the dynamics and thermalization of hardcore bosons and fermions in finite one-dimensional lattices. We perform exact diagonalizations and find that, far away from integrability, few-body observables thermalize. We then study the breakdown of thermalization as one approaches an integrable point. This is found to be a smooth process in which the predictions of standard statistical mechanics continuously worsen as the system moves toward integrability. We establish a direct connection between the presence or absence of thermalization and the validity or failure of the eigenstate thermalization hypothesis, respectively.ReferencesM. Rigol, Phys. Rev. Lett. 103, 100403 (2009); Phys. Rev. A 80, 053607 (2009).
Breakdown of thermalization in finite one-dimensional systems.
Rigol, Marcos
2009-09-04
We use quantum quenches to study the dynamics and thermalization of hard core bosons in finite one-dimensional lattices. We perform exact diagonalizations and find that, far away from integrability, few-body observables thermalize. We then study the breakdown of thermalization as one approaches an integrable point. This is found to be a smooth process in which the predictions of standard statistical mechanics continuously worsen as the system moves toward integrability. We establish a direct connection between the presence or absence of thermalization and the validity or failure of the eigenstate thermalization hypothesis, respectively.
Charge diffusion in the one-dimensional Hubbard model
Steinigeweg, R.; Jin, F; De Raedt, H.; Michielsen, K.; Gemmer, J.
2017-01-01
We study the real-time and real-space dynamics of charge in the one-dimensional Hubbard model in the limit of high temperatures. To this end, we prepare pure initial states with sharply peaked density profiles and calculate the time evolution of these nonequilibrium states, by using numerical forward-propagation approaches to chains as long as 20 sites. For a class of typical states, we find excellent agreement with linear-response theory and unveil the existence of remarkably clean charge di...
Quantum Quench in an Atomic One-Dimensional Ising Chain
Meinert, F.; Mark, M. J.; Kirilov, E.; Lauber, K.; Weinmann, P.; Daley, A. J.; Nägerl, H.-C.
2013-08-01
We study nonequilibrium dynamics for an ensemble of tilted one-dimensional atomic Bose-Hubbard chains after a sudden quench to the vicinity of the transition point of the Ising paramagnetic to antiferromagnetic quantum phase transition. The quench results in coherent oscillations for the orientation of effective Ising spins, detected via oscillations in the number of doubly occupied lattice sites. We characterize the quench by varying the system parameters. We report significant modification of the tunneling rate induced by interactions and show clear evidence for collective effects in the oscillatory response.
Dynamical correlations in one-dimensional charge-transfer insulators
Penc, Karlo; Stephan, Walter
2000-01-01
The single-particle spectral function and the density response of a two band Emery model for CuO chains is calculated for large on-site Cu repulsion U and large on-site energy difference \\Delta. For U>>U-\\Delta>>t the eigenfunctions are products of charge and spin parts, which allows analytical calculation of spectral functions in that limit. For other parameters numerical diagonalization is used. The low energy hole carriers are shown to be the one-dimensional analogs of the Zhang-Rice singl...
One-dimensional metal oxide nanostructures for heterogeneous catalysis.
Zhang, Qian; Wang, Hsin-Yi; Jia, Xinli; Liu, Bin; Yang, Yanhui
2013-08-21
Metal oxides are of paramount importance in heterogeneous catalysis as either supports or active phases. Controlled synthesis of one-dimensional (1D) metal oxide nanostructures has received enormous attention in heterogeneous catalysis due to the possibility of tailoring the properties of metal oxides by tuning their shapes, sizes, and compositions. This feature article highlights recent advances in shape controlled synthesis of 1D metal oxide nanostructures and their applications in heterogeneous catalysis, with the aim of introducing new insights into the heterogeneous catalyst design.
Flow of Helium-4 in One-dimensional Channel
Harris, Clayton R.; Banavar, Samhita; Kim, Duk Y.; Chan, Moses H. W.; Bischof, Jesse; Badding, John V.; Hayes, John; Sazio, Pier
2014-03-01
Superfluidity breaks down in the one-dimensional limit. However, other experiments have demonstrated superfluid flow through pores on the order of nanometers. Here we report on studying liquid helium flow through a single-hole glass capillary with internal diameters ranging from 80 to 150 nm. We observed a significant flow rate increase below the lambda transition temperature. The estimated critical velocities at low temperatures are approximately 10 m/s, which belongs to the highest group of measured critical velocities. Experimental study at Penn State is supported by NSF Grants No. DMR 1103159.
Second Sound in Systems of One-Dimensional Fermions
Matveev, K. A.; Andreev, A. V.
2017-12-01
We study sound in Galilean invariant systems of one-dimensional fermions. At low temperatures, we find a broad range of frequencies in which in addition to the waves of density there is a second sound corresponding to the ballistic propagation of heat in the system. The damping of the second sound mode is weak, provided the frequency is large compared to a relaxation rate that is exponentially small at low temperatures. At lower frequencies, the second sound mode is damped, and the propagation of heat is diffusive.
Correlation function of one-dimensional s = 1 Ising model
Proshkin, A. I.; Ponomareva, T. Yu.; Menshikh, I. A.; Zarubin, A. V.; Kassan-Ogly, F. A.
2017-10-01
The temperature behavior of the Fourier transform of the spin-correlation function has been studied in terms of the one-dimensional Ising model taking into account the interaction between the nearest neighbors in the cases of different signs of exchange interactions, magnetic field, and spin. It has been shown that, in the antiferromagnetic model, in the frustration field, the correlation function has a broad maximum and does not take on the form of a delta function as the temperature approaches zero, which indicates the absence of ordering in the system.
Fourier's law on a one-dimensional optical random lattice
Platini, T.; Harris, R. J.; Karevski, D.
2010-04-01
We study the transport properties of a one-dimensional hard-core bosonic lattice gas coupled to two particle reservoirs at different chemical potentials which generate a current flow through the system. In particular, the influence of random fluctuations of the underlying lattice on the stationary-state properties is investigated. We show analytically that the steady-state density presents a linear profile. The local steady-state current obeys the Fourier law j = -κ(τ)∇n where τ is a typical timescale of the lattice fluctuations and ∇n is the density gradient imposed by the reservoirs.
One-dimensional Cutting Stock Problem with Divisible Items
Tanir, Deniz; Ugurlu, Onur; Guler, Asli; Nuriyev, Urfat
2016-01-01
This paper considers the one-dimensional cutting stock problem with divisible items, which is a new problem in the cutting stock literature. The problem exists in steel industries. In the new problem, each item can be divided into smaller pieces, then they can be recombined again by welding. The objective is to minimize both the trim loss and the number of the welds. We present a mathematical model and a dynamic programming based heuristic for the problem. Furthermore, a software, which is ba...
Black Phosphorus based One-dimensional Photonic Crystals and Microcavities
Kriegel, I
2016-01-01
The latest achievements in the fabrication of black phosphorus thin layers, towards the technological breakthrough of a phosphorene atomically thin layer, are paving the way for a their employment in electronics, optics, and optoelectronics. In this work, we have simulated the optical properties of one-dimensional photonic structures, i.e. photonic crystals and microcavities, in which few-layer black phosphorus is one of the components. The insertion of the 5 nm black phosphorous layers leads to a photonic band gap in the photonic crystals and a cavity mode in the microcavity interesting for light manipulation and emission enhancement.
Chemical potential of one-dimensional simple harmonic oscillators
Energy Technology Data Exchange (ETDEWEB)
Mungan, Carl E [Physics Department, US Naval Academy, Annapolis, MD 21402-5002 (United States)], E-mail: mungan@usna.edu
2009-09-15
Expressions for the chemical potential of an Einstein solid, and of ideal Fermi and Bose gases in an external one-dimensional oscillatory trap, are calculated by two different methods and are all found to share the same functional form. These derivations are easier than traditional textbook calculations for an ideal gas in an infinite three-dimensional square well. Furthermore, the results indicate some important features of chemical potential that could promote student learning in an introductory course in statistical mechanics at the undergraduate level.
ONE-DIMENSIONAL AND TWO-DIMENSIONAL LEADERSHIP STYLES
Directory of Open Access Journals (Sweden)
Nikola Stefanović
2007-06-01
Full Text Available In order to motivate their group members to perform certain tasks, leaders use different leadership styles. These styles are based on leaders' backgrounds, knowledge, values, experiences, and expectations. The one-dimensional styles, used by many world leaders, are autocratic and democratic styles. These styles lie on the two opposite sides of the leadership spectrum. In order to precisely define the leadership styles on the spectrum between the autocratic leadership style and the democratic leadership style, leadership theory researchers use two dimensional matrices. The two-dimensional matrices define leadership styles on the basis of different parameters. By using these parameters, one can identify two-dimensional styles.
Kinks dynamics in one-dimensional coupled map lattices
Fernández, B
1994-01-01
We examine the problem of the dynamics of interfaces in a one-dimensional space-time discrete dynamical system. Two different regimes are studied : the non-propagating and the propagating one. In the first case, after proving the existence of such solutions, we show how they can be described using Taylor expansions. The second situation deals with the assumption of a travelling wave to follow the kink propagation. Then a comparison with the corresponding continuous model is proposed. We find that these methods are useful in simple dynamical situations but their application to complex dynamical behaviour is not yet understood.
One-dimensional Ising model with k-spin interactions
Energy Technology Data Exchange (ETDEWEB)
Fan, Yale, E-mail: yalefan@gmail.com [Department of Physics, Harvard University, Cambridge, MA 02138 (United States)
2011-11-15
We examine a generalization of the one-dimensional Ising model involving interactions among neighbourhoods of k adjacent spins. The model is solved by exploiting a connection to an interesting computational problem that we call 'k-SAT on a ring', and is shown to be equivalent to the nearest-neighbour Ising model in the absence of an external magnetic field. The aim of this paper is to explore an interplay of ideas in the context of a toy problem, while introducing a way of thinking about exactly solvable models in terms of 'computational analogues'.
One-Dimensional Metals Conjugated Polymers, Organic Crystals, Carbon Nanotubes
Roth, Siegmar
2004-01-01
Low-dimensional solids are of fundamental interest in materials science due to their anisotropic properties. Written not only for experts in the field, this book explains the important concepts behind their physics and surveys the most interesting one-dimensional systems and discusses their present and emerging applications in molecular scale electronics. The second edition of this successful book has been completely revised to include the remarkable achievements of the last ten years of research and applications. Chemists, polymer and materials scientists as well as students will find this bo
One-dimensional inverse problems of mathematical physics
Lavrent'ev, M M; Yakhno, V G; Schulenberger, J R
1986-01-01
This monograph deals with the inverse problems of determining a variable coefficient and right side for hyperbolic and parabolic equations on the basis of known solutions at fixed points of space for all times. The problems are one-dimensional in nature since the desired coefficient of the equation is a function of only one coordinate, while the desired right side is a function only of time. The authors use methods based on the spectral theory of ordinary differential operators of second order and also methods which make it possible to reduce the investigation of the inverse problems to the in
Lateral shift in one-dimensional quasiperiodic chiral photonic crystal
Energy Technology Data Exchange (ETDEWEB)
Da, Jian, E-mail: dajian521@sina.com [Department of Information Engineering, Huaian Senior Vocational and Technical School, Feiyao road, Huaian 223005, Jiangsu Province (China); Mo, Qi, E-mail: moqiyueyang@163.com [School of Software, Yunnan University, Cuihu Bai Road, Kunming City, Yunnan Province 650091 (China); Cheng, Yaokun [Department of Information Engineering, Huaian Senior Vocational and Technical School, Feiyao road, Huaian 223005, Jiangsu Province (China); Liu, Taixiang [Taishan Vocational College of Nursing, Shandong Province 271000 (China)
2015-02-01
We investigate the lateral shift of a one-dimensional quasiperiodic photonic crystal consisting of chiral and conventional dielectric materials. The effect of structural irregularity on lateral shift is evaluated by stationary-phase approach. Our results show that the lateral shift can be modulated by varying the structural irregularity in quasiperiodic structure. Besides, the position of peak in lateral shift spectrum stays sensitive to the chiral factor of chiral materials. In comparison with that of periodic structure, quasiperiodic structure provides an extra degree of freedom to manipulate the lateral shift.
Entanglement entropy and complexity for one-dimensional holographic superconductors
Directory of Open Access Journals (Sweden)
Mahdi Kord Zangeneh
2017-08-01
Full Text Available Holographic superconductor is an important arena for holography, as it allows concrete calculations to further understand the dictionary between bulk physics and boundary physics. An important quantity of recent interest is the holographic complexity. Conflicting claims had been made in the literature concerning the behavior of holographic complexity during phase transition. We clarify this issue by performing a numerical study on one-dimensional holographic superconductor. Our investigation shows that holographic complexity does not behave in the same way as holographic entanglement entropy. Nevertheless, the universal terms of both quantities are finite and reflect the phase transition at the same critical temperature.
Luo, Liyan; Xu, Luping; Zhang, Hua
2015-07-07
In order to enhance the robustness and accelerate the recognition speed of star identification, an autonomous star identification algorithm for star sensors is proposed based on the one-dimensional vector pattern (one_DVP). In the proposed algorithm, the space geometry information of the observed stars is used to form the one-dimensional vector pattern of the observed star. The one-dimensional vector pattern of the same observed star remains unchanged when the stellar image rotates, so the problem of star identification is simplified as the comparison of the two feature vectors. The one-dimensional vector pattern is adopted to build the feature vector of the star pattern, which makes it possible to identify the observed stars robustly. The characteristics of the feature vector and the proposed search strategy for the matching pattern make it possible to achieve the recognition result as quickly as possible. The simulation results demonstrate that the proposed algorithm can effectively accelerate the star identification. Moreover, the recognition accuracy and robustness by the proposed algorithm are better than those by the pyramid algorithm, the modified grid algorithm, and the LPT algorithm. The theoretical analysis and experimental results show that the proposed algorithm outperforms the other three star identification algorithms.
An Autonomous Star Identification Algorithm Based on One-Dimensional Vector Pattern for Star Sensors
Luo, Liyan; Xu, Luping; Zhang, Hua
2015-01-01
In order to enhance the robustness and accelerate the recognition speed of star identification, an autonomous star identification algorithm for star sensors is proposed based on the one-dimensional vector pattern (one_DVP). In the proposed algorithm, the space geometry information of the observed stars is used to form the one-dimensional vector pattern of the observed star. The one-dimensional vector pattern of the same observed star remains unchanged when the stellar image rotates, so the problem of star identification is simplified as the comparison of the two feature vectors. The one-dimensional vector pattern is adopted to build the feature vector of the star pattern, which makes it possible to identify the observed stars robustly. The characteristics of the feature vector and the proposed search strategy for the matching pattern make it possible to achieve the recognition result as quickly as possible. The simulation results demonstrate that the proposed algorithm can effectively accelerate the star identification. Moreover, the recognition accuracy and robustness by the proposed algorithm are better than those by the pyramid algorithm, the modified grid algorithm, and the LPT algorithm. The theoretical analysis and experimental results show that the proposed algorithm outperforms the other three star identification algorithms. PMID:26198233
One-Dimensional Forward–Forward Mean-Field Games
Energy Technology Data Exchange (ETDEWEB)
Gomes, Diogo A., E-mail: diogo.gomes@kaust.edu.sa; Nurbekyan, Levon; Sedjro, Marc [King Abdullah University of Science and Technology (KAUST), CEMSE Division (Saudi Arabia)
2016-12-15
While the general theory for the terminal-initial value problem for mean-field games (MFGs) has achieved a substantial progress, the corresponding forward–forward problem is still poorly understood—even in the one-dimensional setting. Here, we consider one-dimensional forward–forward MFGs, study the existence of solutions and their long-time convergence. First, we discuss the relation between these models and systems of conservation laws. In particular, we identify new conserved quantities and study some qualitative properties of these systems. Next, we introduce a class of wave-like equations that are equivalent to forward–forward MFGs, and we derive a novel formulation as a system of conservation laws. For first-order logarithmic forward–forward MFG, we establish the existence of a global solution. Then, we consider a class of explicit solutions and show the existence of shocks. Finally, we examine parabolic forward–forward MFGs and establish the long-time convergence of the solutions.
Dislocation-mediated melting of one-dimensional Rydberg crystals
Sela, Eran; Punk, Matthias; Garst, Markus
2011-08-01
We consider cold Rydberg atoms in a one-dimensional optical lattice in the Mott regime with a single atom per site at zero temperature. An external laser drive with Rabi frequency Ω and laser detuning Δ creates Rydberg excitations whose dynamics is governed by an effective spin-chain model with (quasi) long-range interactions. This system possesses intrinsically a large degree of frustration resulting in a ground-state phase diagram in the (Δ,Ω) plane with a rich topology. As a function of Δ, the Rydberg blockade effect gives rise to a series of crystalline phases commensurate with the optical lattice that form a so-called devil's staircase. The Rabi frequency Ω, on the other hand, creates quantum fluctuations that eventually lead to a quantum melting of the crystalline states. Upon increasing Ω, we find that generically a commensurate-incommensurate transition to a floating Rydberg crystal that supports gapless phonon excitations occurs first. For even larger Ω, dislocations within the floating Rydberg crystal start to proliferate and a second, Kosterlitz-Thouless-Nelson-Halperin-Young dislocation-mediated melting transition finally destroys the crystalline arrangement of Rydberg excitations. This latter melting transition is generic for one-dimensional Rydberg crystals and persists even in the absence of an optical lattice. The floating phase and the concomitant transitions can, in principle, be detected by Bragg scattering of light.
One-Dimensional Forward–Forward Mean-Field Games
Gomes, Diogo A.
2016-11-01
While the general theory for the terminal-initial value problem for mean-field games (MFGs) has achieved a substantial progress, the corresponding forward–forward problem is still poorly understood—even in the one-dimensional setting. Here, we consider one-dimensional forward–forward MFGs, study the existence of solutions and their long-time convergence. First, we discuss the relation between these models and systems of conservation laws. In particular, we identify new conserved quantities and study some qualitative properties of these systems. Next, we introduce a class of wave-like equations that are equivalent to forward–forward MFGs, and we derive a novel formulation as a system of conservation laws. For first-order logarithmic forward–forward MFG, we establish the existence of a global solution. Then, we consider a class of explicit solutions and show the existence of shocks. Finally, we examine parabolic forward–forward MFGs and establish the long-time convergence of the solutions.
Neutron scattering studies of three one-dimensional antiferromagnets
Kenzelmann, M
2001-01-01
observed in the disordered phase of spin-1/2 chains. The magnetic order of the one-dimensional spin-1/2 XY antiferromagnet Cs sub 2 CoCl sub 4 was investigated using neutron diffraction. The magnetic structure has an ordering wave-vector (0, 0.5, 0.5) for T < 217 mK and the magnetic structure is a non-linear structure with the magnetic moments at a small angle to the b axis. Above a field of H = 2.1 T the magnetic order collapses in an apparent first order phase transition, suggesting a transition to a spin-liquid phase. Low-dimensional magnets with low-spin quantum numbers are ideal model systems for investigating strongly interacting macroscopic quantum ground states and their non-linear spin excitations. This thesis describes neutron scattering experiments of three one-dimensional low-spin antiferromagnets where strong quantum fluctuations lead to highly-correlated ground states and unconventional cooperative spin excitations. The excitation spectrum of the antiferromagnetic spin-1 Heisenberg chain CsNi...
Lattice Boltzmann method for one-dimensional vector radiative transfer.
Zhang, Yong; Yi, Hongliang; Tan, Heping
2016-02-08
A one-dimensional vector radiative transfer (VRT) model based on lattice Boltzmann method (LBM) that considers polarization using four Stokes parameters is developed. The angular space is discretized by the discrete-ordinates approach, and the spatial discretization is conducted by LBM. LBM has such attractive properties as simple calculation procedure, straightforward and efficient handing of boundary conditions, and capability of stable and accurate simulation. To validate the performance of LBM for vector radiative transfer, four various test problems are examined. The first case investigates the non-scattering thermal-emitting atmosphere with no external collimated solar. For the other three cases, the external collimated solar and three different scattering types are considered. Particularly, the LBM is extended to solve VRT in the atmospheric aerosol system where the scattering function contains singularities and the hemisphere space distributions for the Stokes vector are presented and discussed. The accuracy and computational efficiency of this algorithm are discussed. Numerical results show that the LBM is accurate, flexible and effective to solve one-dimensional polarized radiative transfer problems.
Pseudo-Static Experiment and Analysis on Seismic Behavior of the RC Columns Strengthened by GHPFRCC
Directory of Open Access Journals (Sweden)
Li Xiuling
2015-09-01
Full Text Available Green high performance fiber reinforced cementitious composites (GHPFRCC are a new class of sustainable cementitious composites, employing a high volume of fly ash to replace cement. In addition to increasing the sustainability of the construction environment, GHPFRCC exhibits a high tensile ductility and multiple cracking behaviors in the strainhardening state. These materials can effectively improve the structural energy dissipation capacity and structural durability. In this study, the optimum mixture ratio of GHPFRCC is presented established using an orthogonal experiment for a specific engineering application. The described GHPFRCC sustains the mechanical performance of concrete and is employed as the outer cladding to strengthen concrete columns. The finite element analysis of the material was based on the software ABAQUS and pseudo static experiments were conducted to exhibit retrofitting of GHPFRCC applied in the rehabilitation of seismic-damaged concrete columns. The computed and experimental results showed that GHPFRCC, while incorporating high volume fly ash, can retain significant multiple cracking behaviors. The energy dissipation capacity of the GHPFRCC reinforced concrete (RC column is better than the comparable unreinforced column.
Energy Technology Data Exchange (ETDEWEB)
Cho, Young Chul; Park, Chang-Hwan; Kim, Dong-Min [FNC Technology Co., Yongin (Korea, Republic of)
2016-10-15
As there are four codes in-vessel analysis code (CSPACE), ex-vessel analysis code (SACAP), corium behavior analysis code (COMPASS), and fission product behavior analysis code, for the analysis of severe accident, it is complex to implement the coupling of codes with the similar methodologies for RELAP and CONTEMPT or SPACE and CAP. Because of that, an efficient coupling so called Pseudo shared memory architecture was introduced. In this paper, coupling methodologies will be compared and the methodology used for the analysis of severe accident will be discussed in detail. The barrier between in-vessel and ex-vessel has been removed for the analysis of severe accidents with the implementation of coupling computer codes with pseudo shared memory architecture based on MPI. The remaining are proper choice and checking of variables and values for the selected severe accident scenarios, e.g., TMI accident. Even though it is possible to couple more than two computer codes with pseudo shared memory architecture, the methodology should be revised to couple parallel codes especially when they are programmed using MPI.
Koju, Vijay
Photonic crystals and their use in exciting Bloch surface waves have received immense attention over the past few decades. This interest is mainly due to their applications in bio-sensing, wave-guiding, and other optical phenomena such as surface field enhanced Raman spectroscopy. Improvement in numerical modeling techniques, state of the art computing resources, and advances in fabrication techniques have also assisted in growing interest in this field. The ability to model photonic crystals computationally has benefited both the theoretical as well as experimental communities. It helps the theoretical physicists in solving complex problems which cannot be solved analytically and helps to acquire useful insights that cannot be obtained otherwise. Experimentalists, on the other hand, can test different variants of their devices by changing device parameters to optimize performance before fabrication. In this dissertation, we develop two commonly used numerical techniques, namely transfer matrix method, and rigorous coupled wave analysis, in C++ and MATLAB, and use two additional software packages, one open-source and another commercial, to model one-dimensional photonic crystals. Different variants of one-dimensional multilayered structures such as perfectly periodic dielectric multilayers, quasicrystals, aperiodic multilayer are modeled, along with one-dimensional photonic crystals with gratings on the top layer. Applications of Bloch surface waves, along with new and novel aperiodic dielectric multilayer structures that support Bloch surface waves are explored in this dissertation. We demonstrate a slow light configuration that makes use of Bloch Surface Waves as an intermediate excitation in a double-prism tunneling configuration. This method is simple compared to the more usual techniques for slowing light using the phenomenon of electromagnetically induced transparency in atomic gases or doped ionic crystals operated at temperatures below 4K. Using a semi
Quantum quench dynamics in analytically solvable one-dimensional models
Iucci, Anibal; Cazalilla, Miguel A.; Giamarchi, Thierry
2008-03-01
In connection with experiments in cold atomic systems, we consider the non-equilibrium dynamics of some analytically solvable one-dimensional systems which undergo a quantum quench. In this quench one or several of the parameters of the Hamiltonian of an interacting quantum system are changed over a very short time scale. In particular, we concentrate on the Luttinger model and the sine-Gordon model in the Luther-Emery point. For the latter, we show that the order parameter and the two-point correlation function relax in the long time limit to the values determined by a generalized Gibbs ensemble first discussed by J. T. Jaynes [Phys. Rev. 106, 620 (1957); 108, 171 (1957)], and recently conjectured by M. Rigol et.al. [Phys. Rev. Lett. 98, 050405 (2007)] to apply to the non-equilibrium dynamics of integrable systems.
Charge diffusion in the one-dimensional Hubbard model
Steinigeweg, R.; Jin, F.; De Raedt, H.; Michielsen, K.; Gemmer, J.
2017-08-01
We study the real-time and real-space dynamics of charge in the one-dimensional Hubbard model in the limit of high temperatures. To this end, we prepare pure initial states with sharply peaked density profiles and calculate the time evolution of these nonequilibrium states, by using numerical forward-propagation approaches to chains as long as 20 sites. For a class of typical states, we find excellent agreement with linear-response theory and unveil the existence of remarkably clean charge diffusion in the regime of strong particle-particle interactions. We additionally demonstrate that, in the half-filling sector, this diffusive behavior does not depend on certain details of our initial conditions, i.e., it occurs for five different realizations with random and nonrandom internal degrees of freedom, single and double occupation of the central site, and displacement of spin-up and spin-down particles.
Wave propagation in one-dimensional nonlinear acoustic metamaterials
Fang, Xin; Wen, Jihong; Bonello, Bernard; Yin, Jianfei; Yu, Dianlong
2017-05-01
The propagation of waves in nonlinear acoustic metamaterial (NAM) is fundamentally different from that in conventional linear ones. In this article we consider two one-dimensional (1D) NAM systems featuring respectively a diatomic and a tetratomic meta unit-cell. We investigate the attenuation of waves, band structures, and bifurcations to demonstrate novel nonlinear effects, which can significantly expand the bandwidth for elastic wave suppression and cause nonlinear wave phenomena. The harmonic averaging approach, continuation algorithm, and Lyapunov exponents (LEs) are combined to study the frequency responses, nonlinear modes, bifurcations of periodic solutions, and chaos. The nonlinear resonances are studied, and the influence of damping on hyperchaotic attractors is evaluated. Moreover, a ‘quantum’ behavior is found between the low-energy and high-energy orbits. This work provides a theoretical base for furthering understandings and applications of NAMs.
Thermal radiation in one-dimensional photonic quasicrystals with graphene
Costa, C. H.; Vasconcelos, M. S.; Fulco, U. L.; Albuquerque, E. L.
2017-10-01
In this work we investigate the thermal power spectra of the electromagnetic radiation through one-dimensional stacks of dielectric layers, with graphene at their interfaces, arranged according to a quasiperiodic structure obeying the Fibonacci (FB), Thue-Morse (TM) and double-period (DP) sequences. The thermal radiation power spectra are determined by means of a theoretical model based on a transfer matrix formalism for both normal and oblique incidence geometries, considering the Kirchhoff's law of thermal radiation. A systematic study of the consequences of the graphene layers in the thermal emittance spectra is presented and discussed. We studied also the radiation spectra considering the case where the chemical potential is changed in order to tune the omnidirectional photonic band gap.
Compaction of quasi-one-dimensional elastoplastic materials
Shaebani, M. Reza; Najafi, Javad; Farnudi, Ali; Bonn, Daniel; Habibi, Mehdi
2017-06-01
Insight into crumpling or compaction of one-dimensional objects is important for understanding biopolymer packaging and designing innovative technological devices. By compacting various types of wires in rigid confinements and characterizing the morphology of the resulting crumpled structures, here, we report how friction, plasticity and torsion enhance disorder, leading to a transition from coiled to folded morphologies. In the latter case, where folding dominates the crumpling process, we find that reducing the relative wire thickness counter-intuitively causes the maximum packing density to decrease. The segment size distribution gradually becomes more asymmetric during compaction, reflecting an increase of spatial correlations. We introduce a self-avoiding random walk model and verify that the cumulative injected wire length follows a universal dependence on segment size, allowing for the prediction of the efficiency of compaction as a function of material properties, container size and injection force.
Magnons in one-dimensional k-component Fibonacci structures
Energy Technology Data Exchange (ETDEWEB)
Costa, C. H., E-mail: carloshocosta@hotmail.com [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, 59072-970 Natal-RN (Brazil); Escola de Ciências e Tecnologia, Universidade Federal do Rio Grande do Norte, 59072-970 Natal-RN (Brazil); Vasconcelos, M. S. [Escola de Ciências e Tecnologia, Universidade Federal do Rio Grande do Norte, 59072-970 Natal-RN (Brazil)
2014-05-07
We have studied the magnon transmission through of one-dimensional magnonic k-component Fibonacci structures, where k different materials are arranged in accordance with the following substitution rule: S{sub n}{sup (k)}=S{sub n−1}{sup (k)}S{sub n−k}{sup (k)} (n≥k=0,1,2,…), where S{sub n}{sup (k)} is the nth stage of the sequence. The calculations were carried out in exchange dominated regime within the framework of the Heisenberg model and taking into account the RPA approximation. We have considered multilayers composed of simple cubic spin-S Heisenberg ferromagnets, and, by using the powerful transfer-matrix method, the spin wave transmission is obtained. It is demonstrated that the transmission coefficient has a rich and interesting magnonic pass- and stop-bands structures, which depends on the frequency of magnons and the k values.
Subvoxel limits of magnetic resonance angiography: One-dimensional case
Takeuchi, Michihiro; Kim, Dongmin; Sekino, Masaki; Ueno, Shoogo; Ohsaki, Hiroyuki; Iriguchi, Norio
2010-05-01
Although the pixel size of magnetic resonance angiography (MRA) defines the spatial resolution of measured images, MRA visualizes blood vessels whose diameters are comparable to or smaller than the pixel size. In the present study, we carried out simplified one-dimensional numerical simulations and two-dimensional imaging experiments to show that discretization errors significantly appear in the measurement of very thin samples, or samples having subpixel structures. Magnetic resonance signals were calculated for a numerical model of blood vessel. The signal intensity was significantly affected by the small displacements. The experimentally obtained signal intensities agreed well with numerical simulations. The signals were summed within a region-of-interest (ROI) covering several pixels. A decrease in the number of pixels included in the ROI led to a decrease in the fluctuation of signal intensity.
Testing of a one dimensional model for Field II calibration
DEFF Research Database (Denmark)
Bæk, David; Jensen, Jørgen Arendt; Willatzen, Morten
2008-01-01
Field II is a program for simulating ultrasound transducer fields. It is capable of calculating the emitted and pulse-echoed fields for both pulsed and continuous wave transducers. To make it fully calibrated a model of the transducer’s electro-mechanical impulse response must be included. We...... examine an adapted one dimensional transducer model originally proposed by Willatzen [9] to calibrate Field II. This model is modified to calculate the required impulse responses needed by Field II for a calibrated field pressure and external circuit current calculation. The testing has been performed...... to the calibrated Field II program for 1, 4, and 10 cycle excitations. Two parameter sets were applied for modeling, one real valued Pz27 parameter set, manufacturer supplied, and one complex valued parameter set found in literature, Alguer´o et al. [11]. The latter implicitly accounts for attenuation. Results show...
Feedback-induced oscillations in one-dimensional colloidal transport.
Lichtner, K; Pototsky, A; Klapp, S H L
2012-11-01
We investigate a driven, one-dimensional system of colloidal particles in a periodically corrugated narrow channel subject to a time-delayed feedback control. Our goal is to identify conditions under which the control induces oscillatory, time-periodic states. The investigations are based on the Fokker-Planck equation involving the density distribution of the system. First, by using the numerical continuation technique, we determine the linear stability of a stationary density. Second, the nonlinear regimes are analyzed by studying numerically the temporal evolution of the first moment of the density distribution. In this way we construct a bifurcation diagram revealing the nature of the instability. Apart from the case of a system with periodic boundary conditions, we also consider a microchannel of finite length. Finally, we study the influence of (repulsive) particle interactions based on dynamical density functional theory.
Exact semiclassical expansions for one-dimensional quantum oscillators
Energy Technology Data Exchange (ETDEWEB)
Delabaere, E. [UMR CNRS J. A. Dieudonne No. 6621, University of Nice, 06108 Nice Cedex 2 (France); Dillinger, H.; Pham, F. [University of Nice, Department of Maths, UMR CNRS J.A. Dieudonne No. 6621, 06108 Nice Cedex 2 (France)
1997-12-01
A set of rules is given for dealing with WKB expansions in the one-dimensional analytic case, whereby such expansions are not considered as approximations but as exact encodings of wave functions, thus allowing for analytic continuation with respect to whichever parameters the potential function depends on, with an exact control of small exponential effects. These rules, which include also the case when there are double turning points, are illustrated on various examples, and applied to the study of bound state or resonance spectra. In the case of simple oscillators, it is thus shown that the Rayleigh{endash}Schr{umlt o}dinger series is Borel resummable, yielding the exact energy levels. In the case of the symmetrical anharmonic oscillator, one gets a simple and rigorous justification of the Zinn-Justin quantization condition, and of its solution in terms of {open_quotes}multi-instanton expansions.{close_quotes} {copyright} {ital 1997 American Institute of Physics.}
Anyon Hubbard Model in One-Dimensional Optical Lattices.
Greschner, Sebastian; Santos, Luis
2015-07-31
Raman-assisted hopping may be used to realize the anyon Hubbard model in one-dimensional optical lattices. We propose a feasible scenario that significantly improves the proposal of T. Keilmann et al. [Nat. Commun. 2, 361 (2011)], allowing as well for an exact realization of the two-body hard-core constraint, and for controllable effective interactions without the need of Feshbach resonances. We show that the combination of anyonic statistics and two-body hard-core constraint leads to a rich ground-state physics, including Mott insulators with attractive interactions, pair superfluids, dimer phases, and multicritical points. Moreover, the anyonic statistics results in a novel two-component superfluid of holon and doublon dimers, characterized by a large but finite compressibility and a multipeaked momentum distribution, which may be easily revealed experimentally.
One-Dimensional Time to Explosion (Thermal Sensitivity) of ANPZ
Energy Technology Data Exchange (ETDEWEB)
Hsu, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hust, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McClelland, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gresshoff, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2014-11-12
Incidents caused by fire and combat operations can heat energetic materials that may lead to thermal explosion and result in structural damage and casualty. Some explosives may thermally explode at fairly low temperatures (< 100 C) and the violence from thermal explosion may cause a significant damage. Thus it is important to understand the response of energetic materials to thermal insults. The One Dimensional Time to Explosion (ODTX) system at the Lawrence Livermore National Laboratory has been used for decades to measure times to explosion, threshold thermal explosion temperature, and determine kinetic parameters of energetic materials. Samples of different configurations (pressed part, powder, paste, and liquid) can be tested in the system. The ODTX testing can also provide useful data for assessing the thermal explosion violence of energetic materials. This report summarizes the recent ODTX experimental data and modeling results for 2,6-diamino-3,5-dintropyrazine (ANPZ).
Well-posedness of one-dimensional Korteweg models
Directory of Open Access Journals (Sweden)
Sylvie Benzoni-Gavage
2006-05-01
Full Text Available We investigate the initial-value problem for one-dimensional compressible fluids endowed with internal capillarity. We focus on the isothermal inviscid case with variable capillarity. The resulting equations for the density and the velocity, consisting of the mass conservation law and the momentum conservation with Korteweg stress, are a system of third order nonlinear dispersive partial differential equations. Additionally, this system is Hamiltonian and admits travelling solutions, representing propagating phase boundaries with internal structure. By change of unknown, it roughly reduces to a quasilinear Schrodinger equation. This new formulation enables us to prove local well-posedness for smooth perturbations of travelling profiles and almost-global existence for small enough perturbations. A blow-up criterion is also derived.
Structure of quasi-one-dimensional ribbon colloid suspensions.
Stratton, Thomas R; Novikov, Sergey; Qato, Ream; Villarreal, Sebastian; Cui, Bianxiao; Rice, Stuart A; Lin, Binhua
2009-03-01
We report the results of an experimental study of a colloid fluid confined to a quasi-one-dimensional (q1D) ribbon channel as a function of channel width and colloid density. Our findings confirm the principal predictions of previous theoretical studies of such systems. These are (1) that the density distribution of the liquid transverse to the ribbon channel exhibits stratification; (2) that even at the highest density the order along the strata, as measured by the longitudinal pair correlation function, is characteristic of a liquid; and (3) the q1D pair correlation functions in different strata exhibit anisotropic behavior resembling that found in a Monte Carlo simulation for the in-plane pair correlation function of a hard sphere fluid in a planar slit.
Hyperbolicity, sinks and measure in one dimensional dynamics
Mañé, Ricardo
1985-12-01
Let f be a C 2 map of the circle or the interval and let Σ( f) denote the complement of the basins of attraction of the attracting periodic orbits. We prove that Σ( f) is a hyperbolic expanding set if (and obviously only if) every periodic point is hyperbolic and Σ( f) doesn't contain the critical point. This is the real one dimensional version of Fatou's hyperbolicity criteria for holomorphic endomorphisms of the Riemann sphere. We also explore other applications of the techniques used for the result above, proving, for instance, that for every C 2 immersion f of the circle (i.e. a map of the circle onto itself without critical points), either its Julia set has measure zero or it is the whole circle and then f is ergodic, i.e. positively invariant Borel sets have zero or full measure.
Magnetic field induced order in quasi-one-dimensional systems
Energy Technology Data Exchange (ETDEWEB)
Dzyaloshinskii, I.E. [Physics Department, University of California, Irvine, UCI, CA 92697 (United States); Kats, E.I., E-mail: efim.i.kats@gmail.com [Laue-Langevin Institute, F-38042, Grenoble (France); L.D. Landau Institute for Theoretical Physics, RAS, 117940 GSP-1, Moscow (Russian Federation)
2012-06-25
We investigate possible ordered phases in a magnetic field in quasi-one-dimensional conductors (Q1D). Long ago [I.E. Dzyaloshinskii, E.I. Kats, JETP 28 (1969) 178] we found that sufficiently strong external magnetic field leads to instability of the Fermi state with an arbitrarily weak repulsion between the particles. In the present communication we generalize this idea and provide more details to assign a physical meaning to such a state. We show that without umklapp processes the found instability corresponds to antiferromagnetic (spin density wave) order, whereas umklapp processes favor to Cooper pairing. -- Highlights: ► Strong magnetic field leads to instability. ► Interparticle repulsion with umklapp processes favor to Cooper pairing. ► Without umklapp processes the instability corresponds to antiferromagnetic order.
A Reduced Order, One Dimensional Model of Joint Response
Energy Technology Data Exchange (ETDEWEB)
DOHNER,JEFFREY L.
2000-11-06
As a joint is loaded, the tangent stiffness of the joint reduces due to slip at interfaces. This stiffness reduction continues until the direction of the applied load is reversed or the total interface slips. Total interface slippage in joints is called macro-slip. For joints not undergoing macro-slip, when load reversal occurs the tangent stiffness immediately rebounds to its maximum value. This occurs due to stiction effects at the interface. Thus, for periodic loads, a softening and rebound hardening cycle is produced which defines a hysteretic, energy absorbing trajectory. For many jointed sub-structures, this hysteretic trajectory can be approximated using simple polynomial representations. This allows for complex joint substructures to be represented using simple non-linear models. In this paper a simple one dimensional model is discussed.
One-dimensional description of driven diffusion in periodic channels
Kalinay, Pavol
2017-10-01
Diffusion of point-like particles driven by a constant longitudinal force in two-dimensional channels of periodically varying width is studied. The dynamics of such systems can be effectively described by the one-dimensional Smoluchowski(-Fick-Jacobs) equation in the longitudinal coordinate x , extended by a space dependent effective diffusion coefficient D (x ) . Our paper is focused on calculation of this function for an arbitrary channel shaping function h (x ) . Unlike the previous algorithms based on scaling of the transverse lengths, the method presented here uses periodicity of the channel. Instead of complicated expansion containing higher order derivatives of h (x ) , the proposed algorithm results in an integral formula for D (x ) , enabling us to study the system for wide range of the driving force and various (periodic) shaping functions h (x ) .
Hidden magnetism in periodically modulated one dimensional dipolar fermions
Fazzini, S.; Montorsi, A.; Roncaglia, M.; Barbiero, L.
2017-12-01
The experimental realization of time-dependent ultracold lattice systems has paved the way towards the implementation of new Hubbard-like Hamiltonians. We show that in a one-dimensional two-components lattice dipolar Fermi gas the competition between long range repulsion and correlated hopping induced by periodically modulated on-site interaction allows for the formation of hidden magnetic phases, with degenerate protected edge modes. The magnetism, characterized solely by string-like nonlocal order parameters, manifests in the charge and/or in the spin degrees of freedom. Such behavior is enlighten by employing Luttinger liquid theory and numerical methods. The range of parameters for which hidden magnetism is present can be reached by means of the currently available experimental setups and probes.
Magnetoresistance anisotropy of a one-dimensional superconducting niobium strip.
Hua, J; Xiao, Z L; Imre, A; Yu, S H; Patel, U; Ocola, L E; Divan, R; Koshelev, A; Pearson, J; Welp, U; Kwok, W K
2008-08-15
We investigated confinement effects on the resistive anisotropy of a superconducting niobium strip with a rectangular cross section. When its transverse dimensions are comparable to the superconducting coherence length, the angle dependent magnetoresistances at a fixed temperature can be scaled as R(theta,H) = R(H/Hctheta) where Hctheta =Hc0(cos2theta + gamma(-2)sin2theta)(-1/2) is the angular dependent critical field, gamma is the width to thickness ratio, and Hc0 is the critical field in the thickness direction at theta=0 degrees . The results can be understood in terms of the anisotropic diamagnetic energy for a given field in a one-dimensional superconductor.
Magnetoresistance anisotropy of a one-dimensional superconducting niobium strip.
Energy Technology Data Exchange (ETDEWEB)
Hua, J.; Xiao, Z. L.; Imre, A.; Yu, S. H.; Patel, U.; Ocola, L. E.; Divan, R.; Koshelev, A.; Pearson, J.; Welp, U.; Kwok, W. K.; Northern Illinois Univ.
2008-01-01
We investigated confinement effects on the resistive anisotropy of a superconducting niobium strip with a rectangular cross section. When its transverse dimensions are comparable to the superconducting coherence length, the angle dependent magnetoresistances at a fixed temperature can be scaled as R({theta},H) = R(H/H{sub c{theta}}) where H{sub c{theta}} = H{sub c0}(cos{sup 2} {theta} + {gamma}{sup -2} sin{sup 2}{theta}){sup -1/2} is the angular dependent critical field, {gamma} is the width to thickness ratio, and H{sub c0} is the critical field in the thickness direction at {theta} = 0{sup o}. The results can be understood in terms of the anisotropic diamagnetic energy for a given field in a one-dimensional superconductor.
Magnetoresistance Anisotropy of a One-Dimensional Superconducting Niobium Strip
Hua, J.; Xiao, Z. L.; Imre, A.; Yu, S. H.; Patel, U.; Ocola, L. E.; Divan, R.; Koshelev, A.; Pearson, J.; Welp, U.; Kwok, W. K.
2008-08-01
We investigated confinement effects on the resistive anisotropy of a superconducting niobium strip with a rectangular cross section. When its transverse dimensions are comparable to the superconducting coherence length, the angle dependent magnetoresistances at a fixed temperature can be scaled as R(θ,H)=R(H/Hcθ) where Hcθ=Hc0(cos2θ+γ-2sin2θ)-1/2 is the angular dependent critical field, γ is the width to thickness ratio, and Hc0 is the critical field in the thickness direction at θ=0°. The results can be understood in terms of the anisotropic diamagnetic energy for a given field in a one-dimensional superconductor.
Anisotropic magnetoresistance of a one-dimensional superconducting niobium strip
Hua, Jiong; Xiao, Zhili; Imre, Alexandra; Yu, Suhong; Patel, Umesh; Ocola, Leo; Divan, Ralu; Koshelev, Alexei; Pearson, John; Welp, Ulrich; Kwok, Wai-Kwong
2009-03-01
We investigated confinement effects on the resistive anisotropy of a superconducting niobium strip with a rectangular cross-section. When the strip's transverse dimensions are comparable to the superconducting coherence length, we find the angle dependent magentoresistances at a fixed temperature can be scaled as R(θ, H) = R(H /Hcθ) where Hcθ = Hc0 (cos^2θ+γ-2sin^2θ)-1/2 is the angular dependent critical field, γ = w/d is the width to thickness ratio of the strip, and Hc0 is the out-plane critical field at θ = 0 . Our results can be understood in terms of the anisotropic diamagnetic energy of a one-dimensional superconductor in a magnetic field.
One-dimensional Electron Gases at Oxide Interfaces
Cao, Yanwei; Zhong, Zhicheng; Shafer, P.; Liu, Xiaoran; Kareev, M.; Middey, S.; Meyers, D.; Arenholz, E.; Chakhalian, Jak
Emergence of two-dimensional electron gases (2DEG) at the oxide interfaces of two dissimilar insulators is a remarkable manifestation of interface engineering. With continuously reduced dimensionality, it arises an interesting question: could one-dimensional electron gases (1DEG) be designed at oxide interfaces? So far there is no report on this. Here, we report on the formation of 1DEG at the carefully engineered titanate heterostructures. Combined resonant soft X-ray linear dichroism with electrical transport and the first-principles calculations have confirmed the formation of 1DEG driven by the interfacial symmetry breaking. Our findings provide a route to engineer new electronic and magnetic states. This work was supported by Gordon and Betty Moore Foundation, DODARO, DOE, and the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy.
Topologically protected states in one-dimensional systems
Fefferman, C L; Weinstein, M I
2017-01-01
The authors study a class of periodic Schrödinger operators, which in distinguished cases can be proved to have linear band-crossings or "Dirac points". They then show that the introduction of an "edge", via adiabatic modulation of these periodic potentials by a domain wall, results in the bifurcation of spatially localized "edge states". These bound states are associated with the topologically protected zero-energy mode of an asymptotic one-dimensional Dirac operator. The authors' model captures many aspects of the phenomenon of topologically protected edge states for two-dimensional bulk structures such as the honeycomb structure of graphene. The states the authors construct can be realized as highly robust TM-electromagnetic modes for a class of photonic waveguides with a phase-defect.
Coherence of one-dimensional quantum walk on cycles
He, Zhimin; Huang, Zhiming; Li, Lvzhou; Situ, Haozhen
2017-11-01
Quantum coherence plays a central role in quantum mechanics and provides essential power for quantum information processing. In this paper, we study the dynamics of the l_1 norm coherence in one-dimensional quantum walk on cycles for two initial states. For the first initial state, the walker starts from a single position. The coherence increases with the number of steps at the beginning and then fluctuates over time after approaching to saturation. The coherence with odd number of sites is much larger than that with even number of sites. Another initial state, i.e., the equally superposition state, is also considered. The coherence of the whole system is proved to be N-1 (2N-1) for any odd (even) time step where N is the number of sites. We also investigate the influence of two unitary noises, i.e., noisy Hadamard operator and broken link, on the coherence evolution.
Ultra-fast efficient synthesis of one-dimensional nanostructures
Energy Technology Data Exchange (ETDEWEB)
Dabrowska, Agnieszka; Huczko, Andrzej; Soszynski, Michal [Department of Chemistry, Warsaw University, 1 Pasteur str., 02-093 Warsaw (Poland); Bendjemil, Badis [Department of Physics, University of Badji-Mokhtar, LEREC, BP. 12, 23000 Annaba (Algeria); Micciulla, Federico; Sacco, Immacolata; Coderoni, Laura; Bellucci, Stefano [Laboratori Nazionali di Frascati, Via E. Fermi 40, 00044 Frascati, Roma (Italy)
2011-11-15
Self-propagating high-temperature synthesis (SHS) can be regarded as an efficient method to obtain new nanomaterials. Different starting mixtures of magnesium powder with various carbonates (Li{sub 2}CO{sub 3}, Na{sub 2}CO{sub 3}, CaCO{sub 3}, FeCO{sub 3}, (NH{sub 4}){sub 2}CO{sub 3}) were tried and the auto-thermal reactions were carried out under both reactive (air) and neutral atmosphere (argon) with an initial pressure of 1 or 10 atm to yield novel nanomaterials. Both SiC nanofibres and novel branched SiC nanostructures were also obtained from Si/polytetrafluoroethylene (PTFE) mixtures and their synthesis and purification have been optimized. The application of those one-dimensional (1-D) SiC nanostructures as a composite filler is presented. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
REVIEW One-Dimensional Dynamical Modeling of Earthquakes: A Review
Directory of Open Access Journals (Sweden)
Jeen-Hwa Wang
2008-01-01
Full Text Available Studies of the power-law relations of seismicity and earthquake source parameters based on the one-dimensional (1-D Burridge-Knopoff¡¦s (BK dynamical lattice model, especially those studies conducted by Taiwan¡¦s scientists, are reviewed in this article. In general, velocity- and/or state-dependent friction is considered to control faulting. A uniform distribution of breaking strengths (i.e., the static friction strength is taken into account in some studies, and inhomogeneous distributions in others. The scaling relations in these studies include: Omori¡¦s law, the magnitude-frequency or energy-frequency relation, the relation between source duration time and seismic moment, the relation between rupture length and seismic moment, the frequency-length relation, and the source power spectra. The main parameters of the one-dimensional (1-D Burridge-Knopoff¡¦s (BK dynamical lattice model include: the decreasing rate (r of dynamic friction strength with sliding velocity; the type and degree of heterogeneous distribution of the breaking strengths, the stiffness ratio (i.e., the ratio between the stiffness of the coil spring connecting two mass elements and that of the leaf spring linking a mass element and the moving plate; the frictional drop ratio of the minimum dynamic friction strength to the breaking strength; and the maximum breaking strength. For some authors, the distribution of the breaking strengths was considered to be a fractal function. Hence, the fractal dimension of such a distribution is also a significant parameter. Comparison between observed scaling laws and simulation results shows that the 1-D BK dynamical lattice model acceptably approaches fault dynamics.
Non-equilibrium one-dimensional two-phase flow in variable area channels
Rohatgi, U. S.; Reshotko, E.
1975-01-01
A one-dimensional nonequilibrium flow analysis has been formulated for a one component two phase flow. The flow is considered homogeneous and essentially isothermal. Phase change is assumed to occur at heterogeneous nucleation sites and the growth of the vapor bubbles is governed by heat conduction from the liquid to the bubble. The analysis adjusted for friction is applied to liquid nitrogen flow in a venturi and comparison is made with the NASA experimental results of Simoneau. Good agreement with the experiments is obtained when one assumes the effective activation energy for nucleus formation to be small but nonzero. The computed pressure distributions deviate from the experimental results in the throat region of the venturi in a manner consistent with centrifugal effects not accounted for in the one-dimensional theory. The results are shown to depend not only on cavitation number but on additional dimensionless parameters governing the nonequilibrium production and subsequent growth of nuclei.
A nine-point finite difference scheme for one-dimensional wave equation
Szyszka, Barbara
2017-07-01
The paper is devoted to an implicit finite difference method (FDM) for solving initial-boundary value problems (IBVP) for one-dimensional wave equation. The second-order derivatives in the wave equation have been approximated at the four intermediate points, as a consequence, an implicit nine-point difference scheme has been obtained. Von Neumann stability analysis has been conducted and we have demonstrated, that the presented difference scheme is unconditionally stable.
Pehlivan, M; Hashash, YMA; Harmon, JA; Rathje, EM; Stewart, JP; Silva, SJ; Campbell, KW; Nikolaou, S
2015-01-01
Spatial variability and uncertainties that exist in natural deposits are often modeled in one-dimensional (1D) site response analysis through multiple spatially varied shear wave velocity (VS) profiles. These spatially varied VS profiles usually exhibit VS reversals that might not be observed in the natural deposits. This study investigates the consequences of allowing VS reversals in spatially varied VS on the 1D site response characteristics. Two sets of sixty (60) spatially varied VS profi...
Liang, Hai-Wei; Liu, Shuo; Yu, Shu-Hong
2010-09-15
Template-directed strategy has become one of the most popular methods for the fabrication of one-dimensional (1D) nanostructures with uniform size and controllable physical dimensions in recent years. This Review article describes the recent progress in the synthesis of 1D inorganic nanostructures by using suitable templates. A brief survey on the templating method based on the organic templates and porous membrane is firstly given. Then, the article is focused on recent emerging synthetic strategies by templating against the pre-existing 1D nanostructures using different physical and chemical transformation techniques, including epitaxial growth, nonepitaxial growth, direct chemical transformation, solid-state interfacial diffusion reaction, and so on. The important reactivity role of the 1D nanostructures will be emphasized in such transformation process. Finally, we conclude this paper with some perspectives and outlook on this research topic.
Regression analysis of censored data using pseudo-observations: An update
DEFF Research Database (Denmark)
Overgaard, Morten; Andersen, Per Kragh; Parner, Erik Thorlund
2015-01-01
We present updated versions of the stpsurv, stpci, and stpmean commands, which were introduced in Parner Andersen (2010, Stata Journal 10: 408–422), along with a new command, stplost. The commands generate pseudo-observations of the survival function, the cumulative incidence function under compe...
QTL analysis for early yield in a pseudo F 2 population of cassava ...
African Journals Online (AJOL)
Genetic mapping of early bulking in a full-sib population of cassava was continued in a selfed family of 268 cassava plants derived from a single progeny of the full-sib population. The pseudo F2 population was analysed with 122 segregating SSR markers. A previously constructed linkage map of cassava consisting of 22 ...
Studies on one-dimensional polyaniline (PANI) nanostructures and the morphological evolution
Energy Technology Data Exchange (ETDEWEB)
Sun Qunhui [IPST at GT and School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 500 10th St., NW, Atlanta, GA 30332-0620 (United States)], E-mail: Qunhui.Sun@ipst.gatech.edu; Park, Myung-Chul; Deng Yulin [IPST at GT and School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 500 10th St., NW, Atlanta, GA 30332-0620 (United States)
2008-08-15
In this context, we studied the morphologies and morphology evolution of one-dimensional polyaniline (PANI) nanostructures during a wet chemical oxidation process via scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis methods. The results showed that the one-dimensional nanostructures of PANI followed a nucleation, agglomeration or self-growing processes, sequentially. Two distinctive morphologies were observed. One was that cylindrical nanotubes derived, most probably, from the self growing of the as-formed bubble-like ribbons. Another one, in comparison, was rectangular nanotubing structures stemmed from, apparently, a self-guided agglomerating or aggregating process of the as-formed primary nanoparticles, as confirmed unambiguously by both SEM and TEM observations. While the diameters of either individual or hyperbranched PANI nanotubes having a smooth surface were in the range of 250-1500 nm, the size of the rectangular nanotubings was ca. 600 nm.
Fractal geometry in an expanding, one-dimensional, Newtonian universe.
Miller, Bruce N; Rouet, Jean-Louis; Le Guirriec, Emmanuel
2007-09-01
Observations of galaxies over large distances reveal the possibility of a fractal distribution of their positions. The source of fractal behavior is the lack of a length scale in the two body gravitational interaction. However, even with new, larger, sample sizes from recent surveys, it is difficult to extract information concerning fractal properties with confidence. Similarly, three-dimensional N-body simulations with a billion particles only provide a thousand particles per dimension, far too small for accurate conclusions. With one-dimensional models these limitations can be overcome by carrying out simulations with on the order of a quarter of a million particles without compromising the computation of the gravitational force. Here the multifractal properties of two of these models that incorporate different features of the dynamical equations governing the evolution of a matter dominated universe are compared. For each model at least two scaling regions are identified. By employing criteria from dynamical systems theory it is shown that only one of them can be geometrically significant. The results share important similarities with galaxy observations, such as hierarchical clustering and apparent bifractal geometry. They also provide insights concerning possible constraints on length and time scales for fractal structure. They clearly demonstrate that fractal geometry evolves in the mu (position, velocity) space. The observed patterns are simply a shadow (projection) of higher-dimensional structure.
Photoemission properties of quasi-one-dimensional conductors
Energy Technology Data Exchange (ETDEWEB)
Losic, Z Bonacic [Department of Physics, Faculty of Natural Sciences, Mathematics and Education, University of Split, Teslina 12, 21000 Split (Croatia); Zupanovic, P [Department of Physics, Faculty of Natural Sciences, Mathematics and Education, University of Split, Teslina 12, 21000 Split (Croatia); Bjelis, A [Department of Physics, Faculty of Science, University of Zagreb, POB 162, 10001 Zagreb (Croatia)
2006-04-19
We calculate the one-particle spectral function and the corresponding derived quantities for a chain lattice with a one-dimensional conducting electron band, and with a three-dimensional long-range Coulomb electron-electron interaction treated within the G{sub 0}W{sub 0} approximation. It is shown that due to the anisotropic acoustic dispersion of the plasmon mode, the quasi-particle peak as a standard Fermi liquid feature does not show up in the spectral function. Instead, the latter comprises only a broad maximum with width of the order of plasmon energy. Such spectral properties are in the qualitative agreement with ARPES spectra of Bechgaard salts obtained in recent measurements. The present approach is appropriate for the treatment of wide energy scales defined by the width of the conducting band and the plasmon energy, and is complementary to earlier rigorous results obtained within the Luttinger liquid approach in the asymptotic limit of low energies close to the chemical potential.
A Smart Colorful Supercapacitor with One Dimensional Photonic Crystals.
Liu, Cihui; Liu, Xing; Xuan, Hongyun; Ren, Jiaoyu; Ge, Liqin
2015-12-22
To meet the pressing demands for portable and flexible equipment in contemporary society, developing flexible, lightweight, and sustainable supercapacitor systems with large power densities, long cycle life, and ease of strongly required. However, estimating the state-of-charge of existing supercapacitors is difficult, and thus their service life is limited. In this study, we fabricate a flexible color indicative supercapacitor device with mesoporous polyaniline (mPANI)/Poly(N-Isopropyl acrylamide-Graphene Oxide-Acrylic Acid) (P(NiPPAm-GO-AA)) one dimensional photonic crystals (1DPCs) as the electrode material through a low-cost, eco-friendly, and scalable fabrication process. We found that the state-of-charge could be monitored by the structural color oscillation due to the change in the photonic band gap position of the 1DPCs. The flexible 1DPCs supercapacitor is thin at 3 mm and exhibits good specific capacitance of 22.6 F g(-1) with retention of 91.1% after 3,000 cycles. This study shows the application of the 1DPCs supercapacitor as a visual ultrathin power source. The technology may find many applications in future wearable electronics.
Decay of Bogoliubov excitations in one-dimensional Bose gases
Ristivojevic, Zoran; Matveev, K. A.
2016-07-01
We study the decay of Bogoliubov quasiparticles in one-dimensional Bose gases. Starting from the hydrodynamic Hamiltonian, we develop a microscopic theory that enables one to systematically study both the excitations and their decay. At zero temperature, the leading mechanism of decay of a quasiparticle is disintegration into three others. We find that low-energy quasiparticles (phonons) decay with the rate that scales with the seventh power of momentum, whereas the rate of decay of the high-energy quasiparticles does not depend on momentum. In addition, our approach allows us to study analytically the quasiparticle decay in the whole crossover region between the two limiting cases. When applied to integrable models, including the Lieb-Liniger model of bosons with contact repulsion, our theory confirms the absence of the decay of quasiparticle excitations. We account for two types of integrability-breaking perturbations that enable finite decay: three-body interaction between the bosons and two-body interaction of finite range.
One-Dimensional Electron Transport Layers for Perovskite Solar Cells
Directory of Open Access Journals (Sweden)
Ujwal K. Thakur
2017-04-01
Full Text Available The electron diffusion length (Ln is smaller than the hole diffusion length (Lp in many halide perovskite semiconductors meaning that the use of ordered one-dimensional (1D structures such as nanowires (NWs and nanotubes (NTs as electron transport layers (ETLs is a promising method of achieving high performance halide perovskite solar cells (HPSCs. ETLs consisting of oriented and aligned NWs and NTs offer the potential not merely for improved directional charge transport but also for the enhanced absorption of incoming light and thermodynamically efficient management of photogenerated carrier populations. The ordered architecture of NW/NT arrays affords superior infiltration of a deposited material making them ideal for use in HPSCs. Photoconversion efficiencies (PCEs as high as 18% have been demonstrated for HPSCs using 1D ETLs. Despite the advantages of 1D ETLs, there are still challenges that need to be overcome to achieve even higher PCEs, such as better methods to eliminate or passivate surface traps, improved understanding of the hetero-interface and optimization of the morphology (i.e., length, diameter, and spacing of NWs/NTs. This review introduces the general considerations of ETLs for HPSCs, deposition techniques used, and the current research and challenges in the field of 1D ETLs for perovskite solar cells.
Stepwise Nanopore Evolution in One-Dimensional Nanostructures
Choi, Jang Wook
2010-04-14
We report that established simple lithium (Li) ion battery cycles can be used to produce nanopores inside various useful one-dimensional (1D) nanostructures such as zinc oxide, silicon, and silver nanowires. Moreover, porosities of these 1D nanomaterials can be controlled in a stepwise manner by the number of Li-battery cycles. Subsequent pore characterization at the end of each cycle allows us to obtain detailed snapshots of the distinct pore evolution properties in each material due to their different atomic diffusion rates and types of chemical bonds. Also, this stepwise characterization led us to the first observation of pore size increases during cycling, which can be interpreted as a similar phenomenon to Ostwald ripening in analogous nanoparticle cases. Finally, we take advantage of the unique combination of nanoporosity and 1D materials and demonstrate nanoporous silicon nanowires (poSiNWs) as excellent supercapacitor (SC) electrodes in high power operations compared to existing devices with activated carbon. © 2010 American Chemical Society.
One-dimensional hybrid nanostructures for heterogeneous photocatalysis and photoelectrocatalysis.
Xiao, Fang-Xing; Miao, Jianwei; Tao, Hua Bing; Hung, Sung-Fu; Wang, Hsin-Yi; Yang, Hong Bin; Chen, Jiazang; Chen, Rong; Liu, Bin
2015-05-13
Semiconductor-based photocatalysis and photoelectrocatalysis have received considerable attention as alternative approaches for solar energy harvesting and storage. The photocatalytic or photoelectrocatalytic performance of a semiconductor is closely related to the design of the semiconductor at the nanoscale. Among various nanostructures, one-dimensional (1D) nanostructured photocatalysts and photoelectrodes have attracted increasing interest owing to their unique optical, structural, and electronic advantages. In this article, a comprehensive review of the current research efforts towards the development of 1D semiconductor nanomaterials for heterogeneous photocatalysis and photoelectrocatalysis is provided and, in particular, a discussion of how to overcome the challenges for achieving full potential of 1D nanostructures is presented. It is anticipated that this review will afford enriched information on the rational exploration of the structural and electronic properties of 1D semiconductor nanostructures for achieving more efficient 1D nanostructure-based photocatalysts and photoelectrodes for high-efficiency solar energy conversion. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Digital noise generators using one-dimensional chaotic maps
Energy Technology Data Exchange (ETDEWEB)
Martínez-Ñonthe, J. A; Palacios-Luengas, L.; Cruz-Irisson, M.; Vazquez Medina, R. [Instituto Politécnico Nacional, ESIME-Culhuacan, Santa Ana 1000, 04430, D.F. (Mexico); Díaz Méndez, J. A. [Instituto Nacional de Astrofísica, Óptica y Electrónica, Luis Enrique Erro 1, Tonantzintla, Puebla (Mexico)
2014-05-15
This work shows how to improve the statistical distribution of signals produced by digital noise generators designed with one-dimensional (1-D) chaotic maps. It also shows that in a digital electronic design the piecewise linear chaotic maps (PWLCM) should be considered because they do not have stability islands in its chaotic behavior region, as it occurs in the case of the logistic map, which is commonly used to build noise generators. The design and implementation problems of the digital noise generators are analyzed and a solution is proposed. This solution relates the output of PWLCM, usually defined in the real numbers' domain, with a codebook of S elements, previously defined. The proposed solution scheme produces digital noise signals with a statistical distribution close to a uniform distribution. Finally, this work shows that it is possible to have control over the statistical distribution of the noise signal by selecting the control parameter of the PWLCM and using, as a design criterion, the bifurcation diagram.
A disorder-enhanced quasi-one-dimensional superconductor
Petrović, A. P.; Ansermet, D.; Chernyshov, D.; Hoesch, M.; Salloum, D.; Gougeon, P.; Potel, M.; Boeri, L.; Panagopoulos, C.
2016-01-01
A powerful approach to analysing quantum systems with dimensionality d>1 involves adding a weak coupling to an array of one-dimensional (1D) chains. The resultant quasi-1D (q1D) systems can exhibit long-range order at low temperature, but are heavily influenced by interactions and disorder due to their large anisotropies. Real q1D materials are therefore ideal candidates not only to provoke, test and refine theories of strongly correlated matter, but also to search for unusual emergent electronic phases. Here we report the unprecedented enhancement of a superconducting instability by disorder in single crystals of Na2−δMo6Se6, a q1D superconductor comprising MoSe chains weakly coupled by Na atoms. We argue that disorder-enhanced Coulomb pair-breaking (which usually destroys superconductivity) may be averted due to a screened long-range Coulomb repulsion intrinsic to disordered q1D materials. Our results illustrate the capability of disorder to tune and induce new correlated electron physics in low-dimensional materials. PMID:27448209
Engineering the spin polarization of one-dimensional electrons
Yan, C.; Kumar, S.; Thomas, K.; See, P.; Farrer, I.; Ritchie, D.; Griffiths, J.; Jones, G.; Pepper, M.
2018-02-01
We present results of magneto-focusing on the controlled monitoring of spin polarization within a one-dimensional (1D) channel, and its subsequent effect on modulating the spin–orbit interaction (SOI) in a 2D GaAs electron gas. We demonstrate that electrons within a 1D channel can be partially spin polarized as the effective length of the 1D channel is varied in agreement with the theoretical prediction. Such polarized 1D electrons when injected into a 2D region result in a split in the odd-focusing peaks, whereas the even peaks remain unaffected (single peak). On the other hand, the unpolarized electrons do not affect the focusing spectrum and the odd and even peaks remain as single peaks, respectively. The split in odd-focusing peaks is evidence of direct measurement of spin polarization within a 1D channel, where each sub-peak represents the population of a particular spin state. Confirmation of the spin splitting is determined by a selective modulation of the focusing peaks due to the Zeeman energy in the presence of an in-plane magnetic field. We suggest that the SOI in the 2D regime is enhanced by a stream of polarized 1D electrons. The spatial control of spin states of injected 1D electrons and the possibility of tuning the SOI may open up a new regime of spin-engineering with application in future quantum information schemes.
One-dimensional simulation of lanthanide isotachophoresis using COMSOL.
Dixon, Derek R; Clark, Sue B; Ivory, Cornelius F
2012-03-01
Electrokinetic separations can be used to quickly separate rare earth metals to determine their forensic signature. In this work, we simulate the concentration and separation of trivalent lanthanide cations by isotachophoresis. A one-dimensional simulation is developed using COMSOL v4.0a, a commercial finite element simulator, to represent the isotachophoretic separation of three lanthanides: lanthanum, terbium, and lutetium. The binding ligand chosen for complexation with the lanthanides is α-hydroxyisobutyric acid (HIBA) and the buffer system includes acetate, which also complexes with the lanthanides. The complexes formed between the three lanthanides, HIBA, and acetate are all considered in the simulation. We observe that the presence of only lanthanide:HIBA complexes in a buffer system with 10 mM HIBA causes the slowest lanthanide peak (lutetium) to split from the other analytes. The addition of lanthanide:acetate complexes into the simulation of the same buffer system eliminates this splitting. Decreasing the concentration of HIBA in the buffer to 7 mM causes the analyte stack to migrate faster through the capillary. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Nucleation and growth of nanoscaled one-dimensional materials
Cui, Hongtao
Nanoscaled one-dimensional materials have attracted great interest due to their novel physical and chemical properties. The purpose of this dissertation is to study the nucleation and growth mechanisms of carbon nanotubes and silicon nitride nanowires with their field emission applications in mind. As a result of this research, a novel methodology has been developed to deposit aligned bamboo-like carbon nanotubes on substrates using a methane and ammonia mixture in microwave plasma enhanced chemical deposition. Study of growth kinetics suggests that the carbon diffusion through bulk catalyst particles controls growth in the initial deposition process. Microstructures of carbon nanotubes are affected by the growth temperature and carbon concentration in the gas phase. High-resolution transmission electron microscope confirms the existence of the bamboo-like structure. Electron diffraction reveals that the iron-based catalyst nucleates and sustains the growth of carbon nanotubes. A nucleation and growth model has been constructed based upon experimental data and observations. In the study of silicon nitride nanoneedles, a vapor-liquid-solid model is employed to explain the nucleation and growth processes. Ammonia plasma etching is proposed to reduce the size of the catalyst and subsequently produce the novel needle-like nanostructure. High-resolution transmission electron microscope shows the structure is well crystallized and composed of alpha-silicon nitride. Other observations in the structure are also explained.
One-dimensional flows of an imperfect diatomic gas
1959-01-01
With the assumptions that Berthelot's equation of state accounts for molecular size and intermolecular force effects, and that changes in the vibrational heat capacities are given by a Planck term, expressions are developed for analyzing one-dimensional flows of a diatomic gas. The special cases of flow through normal and oblique shocks in free air at sea level are investigated. It is found that up to a Mach number 10 pressure ratio across a normal shock differs by less than 6 percent from its ideal gas value; whereas at Mach numbers above 4 the temperature rise is considerable below and hence the density rise is well above that predicted assuming ideal gas behavior. It is further shown that only the caloric imperfection in air has an appreciable effect on the pressures developed in the shock process considered. The effects of gaseous imperfections on oblique shock-flows are studied from the standpoint of their influence on the life and pressure drag of a flat plate operating at Mach numbers of 10 and 20. The influence is found to be small. (author)
One-dimensional color order system for dental shade guides.
O'Brien, W J; Groh, C L; Boenke, K M
1989-11-01
The purpose of this study was to re-arrange the master Bioform shade guide into a long-range one-dimensional color system based upon color difference. Although most shade guides may show local order when arranged according to hue, long-range order has not been established. However, shade guide arrangement according to a logical color order would be an advantage to the user. The first step in determining the color order was to measure the color of the shade guide teeth. A methodology was developed for measuring the color by use of a reflectance spectrophotometer. The precision of measurement was determined to be equal to CIE L*a*b* delta E of 0.5. Spectra were obtained and converted into CIE L*a*b* and Munsell notation. The measured colors of the Bioform shades ranged from a Munsell hue of 0.9 Y to 3.5 Y; a value of 6.6 to 7.8; and a chroma of 1.9 to 4.1. The teeth were then arranged visually from light to dark. The correlation coefficient between the visual ranking and color difference was 0.95. There was an inverse correlation between visual ranking and Munsell value, with a correlation coefficient of 0.90. Therefore, the sequence according to color difference provided the better agreement with visual perception.
Negative refraction angular characterization in one-dimensional photonic crystals.
Lugo, Jesus Eduardo; Doti, Rafael; Faubert, Jocelyn
2011-04-06
Photonic crystals are artificial structures that have periodic dielectric components with different refractive indices. Under certain conditions, they abnormally refract the light, a phenomenon called negative refraction. Here we experimentally characterize negative refraction in a one dimensional photonic crystal structure; near the low frequency edge of the fourth photonic bandgap. We compare the experimental results with current theory and a theory based on the group velocity developed here. We also analytically derived the negative refraction correctness condition that gives the angular region where negative refraction occurs. By using standard photonic techniques we experimentally determined the relationship between incidence and negative refraction angles and found the negative refraction range by applying the correctness condition. In order to compare both theories with experimental results an output refraction correction was utilized. The correction uses Snell's law and an effective refractive index based on two effective dielectric constants. We found good agreement between experiment and both theories in the negative refraction zone. Since both theories and the experimental observations agreed well in the negative refraction region, we can use both negative refraction theories plus the output correction to predict negative refraction angles. This can be very useful from a practical point of view for space filtering applications such as a photonic demultiplexer or for sensing applications.
One-Dimensional Electron Transport Layers for Perovskite Solar Cells
Thakur, Ujwal K.; Kisslinger, Ryan; Shankar, Karthik
2017-01-01
The electron diffusion length (Ln) is smaller than the hole diffusion length (Lp) in many halide perovskite semiconductors meaning that the use of ordered one-dimensional (1D) structures such as nanowires (NWs) and nanotubes (NTs) as electron transport layers (ETLs) is a promising method of achieving high performance halide perovskite solar cells (HPSCs). ETLs consisting of oriented and aligned NWs and NTs offer the potential not merely for improved directional charge transport but also for the enhanced absorption of incoming light and thermodynamically efficient management of photogenerated carrier populations. The ordered architecture of NW/NT arrays affords superior infiltration of a deposited material making them ideal for use in HPSCs. Photoconversion efficiencies (PCEs) as high as 18% have been demonstrated for HPSCs using 1D ETLs. Despite the advantages of 1D ETLs, there are still challenges that need to be overcome to achieve even higher PCEs, such as better methods to eliminate or passivate surface traps, improved understanding of the hetero-interface and optimization of the morphology (i.e., length, diameter, and spacing of NWs/NTs). This review introduces the general considerations of ETLs for HPSCs, deposition techniques used, and the current research and challenges in the field of 1D ETLs for perovskite solar cells. PMID:28468280
Integral Transport Theory in One-dimensional Geometries
Energy Technology Data Exchange (ETDEWEB)
Carlvik, I.
1966-06-15
A method called DIT (Discrete Integral Transport) has been developed for the numerical solution of the transport equation in one-dimensional systems. The characteristic features of the method are Gaussian integration over the coordinate as described by Kobayashi and Nishihara, and a particular scheme for the calculation of matrix elements in annular and spherical geometry that has been used for collision probabilities in earlier Flurig programmes. The paper gives a general theory including such things as anisotropic scattering and multi-pole fluxes, and it gives a brief description of the Flurig scheme. Annular geometry is treated in some detail, and corresponding formulae are given for spherical and plane geometry. There are many similarities between DIT and the method of collision probabilities. DIT is in many cases faster, because for a certain accuracy in the fluxes DIT often needs fewer space points than the method of collision probabilities needs regions. Several computer codes using DIT, both one-group and multigroup, have been written. It is anticipated that experience gained in calculations with these codes will be reported in another paper.
One-Dimensional Thermal Violence Cook-Off Test
Cook, Malcolm; Stennett, Christopher; University of Cranfield, Shrivenham, Swindon, SN6 8LA Team; AWE plc, Aldermaston, Reading Bershire, RG7 4PR, UK Team
2017-06-01
The One-Dimensional Thermal Violence (ODTV) test is designed to quantify and rank the violence of HE charges when heated to elevated temperatures. The test design consists of a central spherical explosive pellet encased in two aluminium barrel shaped halves, fitted with a copper sealing ring, encased by two aluminium locking rings placed over them from either end. The outer surface of the capsule is heated uniformly by placing in a pre-heated molten solder bath. This allows the time-to-explosion to be recorded for different initial bath temperatures. The ODTV capsule can hold samples up to 30mm in diameter. Diagnostics include both thermocouples and Photon Dopler Velocimetry (PDV). A series of live firings have been carried out on a range of bespoke HMX/HTPB explosives. These include HMX/HTPB mix ratios of 95/5, 92/8, 90/10, 88/12 and 85/15. These tests showed that the ODTV capsule had sufficient confinement and size that it could capture the spectrum of events expected from these formulations. It has been demonstrated that the deformation of the heater cup (that houses the molten solder) can be used as an additional violence metric along with the fragmentation and PDV wall velocities of the aluminium ODTV capsule.
Directory of Open Access Journals (Sweden)
V. Lucarini
2012-01-01
Full Text Available The understanding of the statistical properties and of the dynamics of multistable systems is gaining more and more importance in a vast variety of scientific fields. This is especially relevant for the investigation of the tipping points of complex systems. Sometimes, in order to understand the time series of given observables exhibiting bimodal distributions, simple one-dimensional Langevin models are fitted to reproduce the observed statistical properties, and used to investing-ate the projected dynamics of the observable. This is of great relevance for studying potential catastrophic changes in the properties of the underlying system or resonant behaviours like those related to stochastic resonance-like mechanisms. In this paper, we propose a framework for encasing this kind of studies, using simple box models of the oceanic circulation and choosing as observable the strength of the thermohaline circulation. We study the statistical properties of the transitions between the two modes of operation of the thermohaline circulation under symmetric boundary forcings and test their agreement with simplified one-dimensional phenomenological theories. We extend our analysis to include stochastic resonance-like amplification processes. We conclude that fitted one-dimensional Langevin models, when closely scrutinised, may result to be more ad-hoc than they seem, lacking robustness and/or well-posedness. They should be treated with care, more as an empiric descriptive tool than as methodology with predictive power.
Shell-crossing in quasi-one-dimensional flow
Rampf, Cornelius; Frisch, Uriel
2017-10-01
Blow-up of solutions for the cosmological fluid equations, often dubbed shell-crossing or orbit crossing, denotes the breakdown of the single-stream regime of the cold-dark-matter fluid. At this instant, the velocity becomes multi-valued and the density singular. Shell-crossing is well understood in one dimension (1D), but not in higher dimensions. This paper is about quasi-one-dimensional (Q1D) flow that depends on all three coordinates but differs only slightly from a strictly 1D flow, thereby allowing a perturbative treatment of shell-crossing using the Euler-Poisson equations written in Lagrangian coordinates. The signature of shell-crossing is then just the vanishing of the Jacobian of the Lagrangian map, a regular perturbation problem. In essence, the problem of the first shell-crossing, which is highly singular in Eulerian coordinates, has been desingularized by switching to Lagrangian coordinates, and can then be handled by perturbation theory. Here, all-order recursion relations are obtained for the time-Taylor coefficients of the displacement field, and it is shown that the Taylor series has an infinite radius of convergence. This allows the determination of the time and location of the first shell-crossing, which is generically shown to be taking place earlier than for the unperturbed 1D flow. The time variable used for these statements is not the cosmic time t but the linear growth time τ ˜ t2/3. For simplicity, calculations are restricted to an Einstein-de Sitter universe in the Newtonian approximation, and tailored initial data are used. However it is straightforward to relax these limitations, if needed.
One dimensional blood flow in a planetocentric orbit
Haranas, Ioannis; Gkigkitzis, Ioannis
2012-05-01
All life on earth is accustomed to the presence of gravity. When gravity is altered, biological processes can go awry. It is of great importance to ensure safety during a spaceflight. Long term exposure to microgravity can trigger detrimental physiological responses in the human body. Fluid redistribution coupled with fluid loss is one of the effects. In particular, in microgravity blood volume is shifted towards the thorax and head. Sympathetic nervous system-induced vasoconstriction is needed to maintain arterial pressure, while venoconstriction limits venous pooling of blood prevents further reductions in venous return of blood to the heart. In this paper, we modify an existing one dimensional blood flow model with the inclusion of the hydrostatic pressure gradient that further depends on the gravitational field modified by the oblateness and rotation of the Earth. We find that the velocity of the blood flow VB is inversely proportional to the blood specific volume d, also proportional to the oblateness harmonic coefficient J2, the angular velocity of the Earth ωE, and finally proportional to an arbitrary constant c. For c = -0.39073 and ξH = -0.5 mmHg, all orbits result to less blood flow velocities than that calculated on the surface of the Earth. From all considered orbits, elliptical polar orbit of eccentricity e = 0.2 exhibit the largest flow velocity VB = 1.031 m/s, followed by the orbits of inclination i = 45°and 0°. The Earth's oblateness and its rotation contribute a 0.7% difference to the blood flow velocity.
Equilibration in one-dimensional quantum hydrodynamic systems
Sotiriadis, Spyros
2017-10-01
We study quench dynamics and equilibration in one-dimensional quantum hydrodynamics, which provides effective descriptions of the density and velocity fields in gapless quantum gases. We show that the information content of the large time steady state is inherently connected to the presence of ballistically moving localised excitations. When such excitations are present, the system retains memory of initial correlations up to infinite times, thus evading decoherence. We demonstrate this connection in the context of the Luttinger model, the simplest quantum hydrodynamic model, and in the quantum KdV equation. In the standard Luttinger model, memory of all initial correlations is preserved throughout the time evolution up to infinitely large times, as a result of the purely ballistic dynamics. However nonlinear dispersion or interactions, when separately present, lead to spreading and delocalisation that suppress the above effect by eliminating the memory of non-Gaussian correlations. We show that, for any initial state that satisfies sufficient clustering of correlations, the steady state is Gaussian in terms of the bosonised or fermionised fields in the dispersive or interacting case respectively. On the other hand, when dispersion and interaction are simultaneously present, a semiclassical approximation suggests that localisation is restored as the two effects compensate each other and solitary waves are formed. Solitary waves, or simply solitons, are experimentally observed in quantum gases and theoretically predicted based on semiclassical approaches, but the question of their stability at the quantum level remains to a large extent an open problem. We give a general overview on the subject and discuss the relevance of our findings to general out of equilibrium problems. Dedicated to John Cardy on the occasion of his 70th birthday.
Filtration-guided assembly for patterning one-dimensional nanostructures
Zhang, Yaozhong; Wang, Chuan; Yeom, Junghoon
2017-04-01
Tremendous progress has been made in synthesizing various types of one-dimensional (1D) nanostructures (NSs), such as nanotubes and nanowires, but some technical challenges still remain in the deterministic assembly of the solution-processed 1D NSs for device integration. In this work we investigate a scalable yet inexpensive nanomaterial assembly method, namely filtration-guided assembly (FGA), to place nanomaterials into desired locations as either an individual entity or ensembles, and form functional devices. FGA not only addresses the assembly challenges but also encompasses the notion of green nanomanufacturing, maximally utilizing nanomaterials and eliminating a waste stream of nanomaterials into the environment. FGA utilizes selective filtration of 1D NSs through the open windows on the nanoporous filter membrane whose surface is patterned by a polymer mask for guiding the 1D NS deposition. The modified soft-lithographic technique called blanket transfer (BT) is employed to create the various photoresist patterns of sub-10-micron resolution on the nanoporous filter membrane like mixed cellulose acetate. We use single-walled carbon nanotubes (SWCNTs) as a model 1D NS and demonstrate the fabrication of an array pattern of homogeneous 1D NS network films over an area of 20 cm2 within 10 min. The FGA-patterned SWCNT network films are transferred onto the substrate using the adhesive-based transfer technique, and show the highly uniform film thickness and resistance measurements across the entire substrate. Finally, the electrical performance of the back-gated transistors made from the FGA and transfer method of 95% pure SWCNTs is demonstrated.
Bottom-Up Syntheses and Characterization of One Dimensional Nanomaterials
Yeh, Yao-Wen
Nanomaterials, materials having at least one dimension below 100 nm, have been creating exciting opportunities for fundamental quantum confinement studies and applications in electronic devices and energy technologies. One obvious and important aspect of nanomaterials is their production. Although nanostructures can be obtained by top-down reductive e-beam lithography and focused ion beam processes, further development of these processes is needed before these techniques can become practical routes to large scale production. On the other hand, bottom-up syntheses, with advantages in material diversity, throughput, and the potential for large volume production, may provide an alternative strategy for creating nanostructures. In this work, we explore syntheses of one dimensional nanostructures based on hydrothermal and arc discharge methods. The first project presented in this thesis involves syntheses of technologically important nanomaterials and their potential application in energy harvesting. In particular, it was demonstrated that single crystal ferroelectric lead magnesium niobate lead titanate (PMN-PT) nanowires can be synthesized by a hydrothermal route. The chemical composition of the synthesized nanowires is near the rhombohedral-monoclinic boundary of PMN-PT, which leads to a high piezoelectric coefficient of 381 pm/V. Finally, the potential use of PMN-PT nanowires in energy harvesting applications was also demonstrated. The second part of this thesis involves the synthesis of carbon and boron nitride nanotubes by dc arc discharges. In particular, we investigated how local plasma related properties affected the synthesis of carbon nanostructures. Finally, we investigated the anodic nature of the arc and how a dc arc discharge can be applied to synthesize boron nitride nanotubes.
Engineering the spin polarization of one-dimensional electrons.
Yan, Chengyu; Kumar, Sanjeev; Thomas, Kalarikad; See, Patrick; Farrer, Ian; Ritchie, David A; Griffiths, John; Jones, G A C; Pepper, Michael
2018-01-15
We present results of magneto-focusing on the controlled monitoring of spin polarization within a one-dimensional (1D) channel, and its subsequent effect on modulating the spin-orbit interaction (SOI) in a 2D GaAs electron gas. We demonstrate that electrons within a 1D channel can be partially spin polarized as the effective length of the 1D channel is varied in agreement with the theoretical prediction. Such polarized 1D electrons when injected into a 2D region result in a split in the odd-focusing peaks, whereas the even peaks remain unaffected (single peak). On the other hand, the unpolarized electrons, achieved by reducing the effective length of the 1D channel, do not affect the focusing spectrum and the odd and even peaks remain as single peaks, respectively. The split in odd-focusing peaks is evidence of direct measurement of spin polarization within a 1D channel, where each sub-peak represents the population of a particular spin state. Confirmation of the spin splitting is determined by a selective modulation of the focusing peaks due to the Zeeman energy in the presence of an in-plane magnetic field. We suggest that the SOI in the 2D regime is enhanced by a stream of polarized 1D electrons. The spatial control of spin states of injected 1D electrons and the possibility of tuning the SOI may open up a new regime of spin-engineering with application in future quantum information schemes. Creative Commons Attribution license.
One-Dimensional Liquid ^{4}He: Dynamical Properties beyond Luttinger-Liquid Theory.
Bertaina, G; Motta, M; Rossi, M; Vitali, E; Galli, D E
2016-04-01
We compute the zero-temperature dynamical structure factor of one-dimensional liquid ^{4}He by means of state-of-the-art quantum Monte Carlo and analytic continuation techniques. By increasing the density, the dynamical structure factor reveals a transition from a highly compressible critical liquid to a quasisolid regime. In the low-energy limit, the dynamical structure factor can be described by the quantum hydrodynamic Luttinger-liquid theory, with a Luttinger parameter spanning all possible values by increasing the density. At higher energies, our approach provides quantitative results beyond the Luttinger-liquid theory. In particular, as the density increases, the interplay between dimensionality and interaction makes the dynamical structure factor manifest a pseudo-particle-hole continuum typical of fermionic systems. At the low-energy boundary of such a region and moderate densities, we find consistency, within statistical uncertainties, with predictions of a power-law structure by the recently developed nonlinear Luttinger-liquid theory. In the quasisolid regime, we observe a novel behavior at intermediate momenta, which can be described by new analytical relations that we derive for the hard-rods model.
One-Dimensional Liquid 4He: Dynamical Properties beyond Luttinger-Liquid Theory
Bertaina, G.; Motta, M.; Rossi, M.; Vitali, E.; Galli, D. E.
2016-04-01
We compute the zero-temperature dynamical structure factor of one-dimensional liquid 4He by means of state-of-the-art quantum Monte Carlo and analytic continuation techniques. By increasing the density, the dynamical structure factor reveals a transition from a highly compressible critical liquid to a quasisolid regime. In the low-energy limit, the dynamical structure factor can be described by the quantum hydrodynamic Luttinger-liquid theory, with a Luttinger parameter spanning all possible values by increasing the density. At higher energies, our approach provides quantitative results beyond the Luttinger-liquid theory. In particular, as the density increases, the interplay between dimensionality and interaction makes the dynamical structure factor manifest a pseudo-particle-hole continuum typical of fermionic systems. At the low-energy boundary of such a region and moderate densities, we find consistency, within statistical uncertainties, with predictions of a power-law structure by the recently developed nonlinear Luttinger-liquid theory. In the quasisolid regime, we observe a novel behavior at intermediate momenta, which can be described by new analytical relations that we derive for the hard-rods model.
Homeotopy groups of one-dimensional foliations on surfaces
Directory of Open Access Journals (Sweden)
Сергій Іванович Максименко
2017-08-01
Full Text Available Let $Z$ be a non-compact two-dimensional manifold obtained from a family of open strips $\\mathbb{R}\\times(0,1$ with boundary intervals by gluing those strips along their boundary intervals.Every such strip has a foliation into parallel lines $\\mathbb{R}\\times t$, $t\\in(0,1$, and boundary intervals, whence we get a foliation $\\Delta$ on all of $Z$.Many types of foliations on surfaces with leaves homeomorphic to the real line have such ``striped'' structure.That fact was discovered by W.~Kaplan (1940-41 for foliations on the plane $\\mathbb{R}^2$ by level-set of pseudo-harmonic functions $\\mathbb{R}^2 \\to \\mathbb{R}$ without singularities. Previously, the first two authors studied the homotopy type of the group $\\mathcal{H}(\\Delta$ of homeomorphisms of $Z$ sending leaves of $\\Delta$ onto leaves, and shown that except for two cases the identity path component $\\mathcal{H}_{0}(\\Delta$ of $\\mathcal{H}(\\Delta$ is contractible.The aim of the present paper is to show that the quotient $\\mathcal{H}(\\Delta/ \\mathcal{H}_{0}(\\Delta$ can be identified with the group of automorphisms of a certain graph with additional structure encoding the ``combinatorics'' of gluing.
Molecular self-assembly into one-dimensional nanostructures.
Palmer, Liam C; Stupp, Samuel I
2008-12-01
Self-assembly of small molecules into one-dimensional nanostructures offers many potential applications in electronically and biologically active materials. The recent advances discussed in this Account demonstrate how researchers can use the fundamental principles of supramolecular chemistry to craft the size, shape, and internal structure of nanoscale objects. In each system described here, we used atomic force microscopy (AFM) and transmission electron microscopy (TEM) to study the assembly morphology. Circular dichroism, nuclear magnetic resonance, infrared, and optical spectroscopy provided additional information about the self-assembly behavior in solution at the molecular level. Dendron rod-coil molecules self-assemble into flat or helical ribbons. They can incorporate electronically conductive groups and can be mineralized with inorganic semiconductors. To understand the relative importance of each segment in forming the supramolecular structure, we synthetically modified the dendron, rod, and coil portions. The self-assembly depended on the generation number of the dendron, the number of hydrogen-bonding functions, and the length of the rod and coil segments. We formed chiral helices using a dendron-rod-coil molecule prepared from an enantiomerically enriched coil. Because helical nanostructures are important targets for use in biomaterials, nonlinear optics, and stereoselective catalysis, researchers would like to precisely control their shape and size. Tripeptide-containing peptide lipid molecules assemble into straight or twisted nanofibers in organic solvents. As seen by AFM, the sterics of bulky end groups can tune the helical pitch of these peptide lipid nanofibers in organic solvents. Furthermore, we demonstrated the potential for pitch control using trans-to-cis photoisomerization of a terminal azobenzene group. Other molecules called peptide amphiphiles (PAs) are known to assemble in water into cylindrical nanostructures that appear as nanofiber
Kohl, F S; Pringuey, D; Cherikh, F; Belugou, J L; Cherrey, C
2000-01-01
Pseudo depressive dementia is a common pathology for elderly patients. Classically, it is said that depression is taking the mask of dementia, but very often deterioration and depression are present at the same time. Sleep EEG can help the clinician to differentiate dementia and depression in pseudo depressive dementia. Slow Wave Sleep (SWS) is a good indicator of deterioration process. We tried to improve the sleep recording and analysis and our ability to differentiate SWS in this indication. We use a portable digital recording material (Hypnotrace). The signal is analysed by the association of a visual standard method to Digital Periodic Analysis (DPA) which is very sensitive to SWS. The visual analysis gives informations about the macroarchitecture of the night. The Digital Periodic Analysis gives at any moment the value of the wave frequency and thus informations about the microarchitecture. Our hypothesis is that this association helps to better recognise SWS and thus improves sleep EEG as a diagnostic tool in this indication. 23 inpatients meeting both the criteria for major depression and dementia (DSM IV) have been recorded during two nights after 15 days of wash out and before antidepressant treatment. The recordings are analysed with the visual standard method and with the help of DPA. The patients are evaluated every 15 days during two months in order to define three groups based on the clinical evolution. The scoring with DPA is more sensitive to Slow Wave Sleep, particularly for the patients with good clinical evolution (with the strongest depressive component). Thus, this method could be a good diagnostic tool to differentiate dementia and depression in pseudo depressive dementia.
SOAS: a free program to analyze electrochemical data and other one-dimensional signals.
Fourmond, Vincent; Hoke, Kevin; Heering, Hendrik A; Baffert, Carole; Leroux, Fanny; Bertrand, Patrick; Léger, Christophe
2009-09-01
This paper describes an open source program called SOAS, which we developed with the aim of analysing one-dimensional signals. It offers a large set of commands for handling voltammetric and chronoamperometric data, including smoothing signals, differentiation, subtracting baselines, fitting current responses, measuring limiting currents, and searching for peak positions. Although emphasis is on the analysis of electrochemical signals, particularly protein film voltammetry data, SOAS may also prove useful for processing spectra. This free program is available by download from the Internet, and can be installed on computers running any flavor of Unix or Linux, most easily on MacOS X.
Superluminal pulse reflection in asymmetric one-dimensional photonic band gaps.
Longhi, S
2001-09-01
Superluminal pulse reflection is shown to occur in a class of one-dimensional asymmetric photonic band gaps in which a spectral window inside the gap is opened. By means of a coupled-mode equation analysis, we describe in detail two possible realizations of superluminal pulse reflection that can be achieved using fiber Bragg gratings. The former method is based on the introduction of a defect into the otherwise periodic dielectric structure, whereas the latter one exploits the interference of two closely-spaced resonance modes and simulates the dispersion properties of an inverted medium possessing a doublet line.
A One-Dimensional Global-Scaling Erosive Burning Model Informed by Blowing Wall Turbulence
Kibbey, Timothy P.
2014-01-01
A derivation of turbulent flow parameters, combined with data from erosive burning test motors and blowing wall tests results in erosive burning model candidates useful in one-dimensional internal ballistics analysis capable of scaling across wide ranges of motor size. The real-time burn rate data comes from three test campaigns of subscale segmented solid rocket motors tested at two facilities. The flow theory admits the important effect of the blowing wall on the turbulent friction coefficient by using blowing wall data to determine the blowing wall friction coefficient. The erosive burning behavior of full-scale motors is now predicted more closely than with other recent models.
One-dimensional porous silicon photonic crystals for visible and NIR applications
Energy Technology Data Exchange (ETDEWEB)
Xifre Perez, E.; Trifonov, T.; Pallares, J.; Marsal, L.F. [Departament d' Enginyeria Electronica, Electrica i Automatica, ETSE, Campus Sescelades, Universitat Rovira i Virgili, Avda. Paisos Catalans 26, 43007 Tarragona (Spain)
2005-06-01
We present one-dimensional porous silicon photonic crystals that exhibit two band gaps in the NIR region and two band gaps in the visible region. These photonic crystals are made by periodically repeating two porous silicon layers with different refractive index. Theoretical analysis demonstrates that they are suitable for obtaining omnidirectional mirrors to be applied in the infrared region, especially for the wavelength of 1.55 {mu}m. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
Analysis of RDX-TAGzT pseudo-propellant combustion with detailed chemical kinetics
Kumbhakarna, Neeraj; Thynell, Stefan T.; Chowdhury, Arindrajit; Lin, Ping
2011-12-01
A detailed model of steady-state combustion of a pseudo-propellant containing cyclotrimethylene trinitramine (RDX) and triaminoguanidinium azotetrazolate (TAGzT) is presented. The physicochemical processes occurring within the foam layer, comprised of a liquid and gas bubbles, and a gas-phase region above the burning surface are considered. The chemical kinetics is represented by a global thermal decomposition mechanism within the liquid by considering 18 species and eight chemical reactions. The reactions governing decomposition of TAGzT were deduced from separate confined rapid thermolysis experiments using Fourier transform infrared spectroscopy and time-of-flight mass spectrometry. Within the gas bubbles and gas-phase region, a detailed chemical kinetics mechanism was used by considering up to 93 species and 504 reactions. The pseudo-propellant burn rate was found to be highly sensitive to the global decomposition reactions of TAGzT. The predicted results of burn rate agree well with experimental burn-rate data. The increase in burn rate by inclusion of TAGzT is due in part from exothermic decomposition of the azotetrazolate within the foam layer, and from fast gas-phase reactions between triaminoguanidine decomposition products, such as hydrazine, and oxidiser products from the nitramine decomposition.
Lime Kiln Modeling. CFD and One-dimensional simulations
Energy Technology Data Exchange (ETDEWEB)
Svedin, Kristoffer; Ivarsson, Christofer; Lundborg, Rickard
2009-03-15
The incentives for burning alternative fuels in lime kilns are growing. An increasing demand on thorough investigations of alternative fuel impact on lime kiln performance have been recognized, and the purpose of this project has been to develop a lime kiln CFD model with the possibility to fire fuel oil and lignin. The second part of the project consists of three technical studies. Simulated data from a one-dimensional steady state program has been used to support theories on the impact of biofuels and lime mud dryness. The CFD simulations was carried out in the commercial code FLUENT. Due to difficulties with the convergence of the model the calcination reaction is not included. The model shows essential differences between the two fuels. Lignin gives a different flame shape and a longer flame length compared to fuel oil. Mainly this depends on how the fuel is fed into the combustion chamber and how much combustion air that is added as primary and secondary air. In the case of lignin combustion the required amount of air is more than in the fuel oil case. This generates more combustion gas and a different flow pattern is created. Based on the values from turbulent reaction rate for the different fuels an estimated flame length can be obtained. For fuel oil the combustion is very intense with a sharp peak in the beginning and a rapid decrease. For lignin the combustion starts not as intense as for the fuel oil case and has a smoother shape. The flame length appears to be approximately 2-3 meter longer for lignin than for fuel oil based on turbulent reaction rate in the computational simulations. The first technical study showed that there are many benefits of increasing dry solids content in the lime mud going into a kiln such as increased energy efficiency, reduced TRS, and reduced sodium in the kiln. However, data from operating kilns indicates that these benefits can be offset by increasing exit gas temperature that can limit kiln production capacity. Simulated
A new digitized reverse correction method for hypoid gears based on a one-dimensional probe
Li, Tianxing; Li, Jubo; Deng, Xiaozhong; Yang, Jianjun; Li, Genggeng; Ma, Wensuo
2017-12-01
In order to improve the tooth surface geometric accuracy and transmission quality of hypoid gears, a new digitized reverse correction method is proposed based on the measurement data from a one-dimensional probe. The minimization of tooth surface geometrical deviations is realized from the perspective of mathematical analysis and reverse engineering. Combining the analysis of complex tooth surface generation principles and the measurement mechanism of one-dimensional probes, the mathematical relationship between the theoretical designed tooth surface, the actual machined tooth surface and the deviation tooth surface is established, the mapping relation between machine-tool settings and tooth surface deviations is derived, and the essential connection between the accurate calculation of tooth surface deviations and the reverse correction method of machine-tool settings is revealed. Furthermore, a reverse correction model of machine-tool settings is built, a reverse correction strategy is planned, and the minimization of tooth surface deviations is achieved by means of the method of numerical iterative reverse solution. On this basis, a digitized reverse correction system for hypoid gears is developed by the organic combination of numerical control generation, accurate measurement, computer numerical processing, and digitized correction. Finally, the correctness and practicability of the digitized reverse correction method are proved through a reverse correction experiment. The experimental results show that the tooth surface geometric deviations meet the engineering requirements after two trial cuts and one correction.
Energy Technology Data Exchange (ETDEWEB)
Juillet, O.; Gulminelli, F. [Caen Univ., Lab. de Physique Corpusculaire (LPC/ENSICAEN), 14 (France); Chomaz, Ph. [Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France)
2003-11-01
The canonical thermodynamic properties of a one-dimensional system of interacting spin-1/2 fermions with an attractive zero-range pseudo-potential are investigated within an exact approach. The density operator is evaluated as the statistical average of dyadics formed from a stochastic mean-field propagation of independent Slater determinants. For an harmonically trapped Fermi gas and for fermions confined in a 1D-like torus, we observe the transition to a quasi-BCS state with Cooper-like momentum correlations and an algebraic long-range order. For few trapped fermions in a rotating torus, a dominant superfluid component with quantized circulation can be isolated. (author)
Novel Method of Detecting Movement of the Interference Fringes Using One-Dimensional PSD
Directory of Open Access Journals (Sweden)
Qi Wang
2015-06-01
Full Text Available In this paper, a method of using a one-dimensional position-sensitive detector (PSD by replacing charge-coupled device (CCD to measure the movement of the interference fringes is presented first, and its feasibility is demonstrated through an experimental setup based on the principle of centroid detection. Firstly, the centroid position of the interference fringes in a fiber Mach-Zehnder (M-Z interferometer is solved in theory, showing it has a higher resolution and sensitivity. According to the physical characteristics and principles of PSD, a simulation of the interference fringe’s phase difference in fiber M-Z interferometers and PSD output is carried out. Comparing the simulation results with the relationship between phase differences and centroid positions in fiber M-Z interferometers, the conclusion that the output of interference fringes by PSD is still the centroid position is obtained. Based on massive measurements, the best resolution of the system is achieved with 5.15, 625 μm. Finally, the detection system is evaluated through setup error analysis and an ultra-narrow-band filter structure. The filter structure is configured with a one-dimensional photonic crystal containing positive and negative refraction material, which can eliminate background light in the PSD detection experiment. This detection system has a simple structure, good stability, high precision and easily performs remote measurements, which makes it potentially useful in material small deformation tests, refractivity measurements of optical media and optical wave front detection.
Effects of Initial Symmetry on the Global Symmetry of One-Dimensional Legal Cellular Automata
Directory of Open Access Journals (Sweden)
Ikuko Tanaka
2015-09-01
Full Text Available To examine the development of pattern formation from the viewpoint of symmetry, we applied a two-dimensional discrete Walsh analysis to a one-dimensional cellular automata model under two types of regular initial conditions. The amount of symmetropy of cellular automata (CA models under regular and random initial conditions corresponds to three Wolfram’s classes of CAs, identified as Classes II, III, and IV. Regular initial conditions occur in two groups. One group that makes a broken, regular pattern formation has four types of symmetry, whereas the other group that makes a higher hierarchy pattern formation has only two types. Additionally, both final pattern formations show an increased amount of symmetropy as time passes. Moreover, the final pattern formations are affected by iterations of base rules of CA models of chaos dynamical systems. The growth design formations limit possibilities: the ratio of developing final pattern formations under a regular initial condition decreases in the order of Classes III, II, and IV. This might be related to the difference in degree in reference to surrounding conditions. These findings suggest that calculations of symmetries of the structures of one-dimensional cellular automata models are useful for revealing rules of pattern generation for animal bodies.
Challamel, Noël; Grazide, Cécile; Picandet, Vincent; Perrot, Arnaud; Zhang, Yingyan
2016-06-01
This study focuses on heat conduction in unidimensional lattices also known as microstructured rods. The lattice thermal properties can be representative of concentrated thermal interface phases in one-dimensional segmented rods. The exact solution of the linear time-dependent spatial difference equation associated with the lattice problem is presented for some given initial and boundary conditions. This exact solution is compared to the quasicontinuum approximation built by continualization of the lattice equations. A rational-based asymptotic expansion of the pseudo-differential problem leads to an equivalent nonlocal-type Fourier's law. The differential nonlocal Fourier's law is analysed with respect to thermodynamic models available in the literature, such as the Guyer-Krumhansl-type equation. The length scale of the nonlocal heat law is calibrated with respect to the lattice spacing. An error analysis is conducted for quantifying the efficiency of the nonlocal model to capture the lattice evolution problem, as compared to the local model. The propagation of error with the nonlocal model is much slower than that in its local counterpart. A two-dimensional thermal lattice is also considered and approximated by a two-dimensional nonlocal heat problem. It is shown that nonlocal and continualized heat equations both approximate efficiently the two-dimensional thermal lattice response. These extended continuous heat models are shown to be good candidates for approximating the heat transfer behaviour of microstructured rods or membranes.
Analysis of Forest Fires by means of Pseudo Phase Plane and Multidimensional Scaling Methods
Directory of Open Access Journals (Sweden)
J. A. Tenreiro Machado
2014-01-01
Full Text Available Forest fires dynamics is often characterized by the absence of a characteristic length-scale, long range correlations in space and time, and long memory, which are features also associated with fractional order systems. In this paper a public domain forest fires catalogue, containing information of events for Portugal, covering the period from 1980 up to 2012, is tackled. The events are modelled as time series of Dirac impulses with amplitude proportional to the burnt area. The time series are viewed as the system output and are interpreted as a manifestation of the system dynamics. In the first phase we use the pseudo phase plane (PPP technique to describe forest fires dynamics. In the second phase we use multidimensional scaling (MDS visualization tools. The PPP allows the representation of forest fires dynamics in two-dimensional space, by taking time series representative of the phenomena. The MDS approach generates maps where objects that are perceived to be similar to each other are placed on the map forming clusters. The results are analysed in order to extract relationships among the data and to better understand forest fires behaviour.
One-dimensional map lattices: Synchronization, bifurcations, and chaotic structures
DEFF Research Database (Denmark)
Belykh, Vladimir N.; Mosekilde, Erik
1996-01-01
The paper presents a qualitative analysis of coupled map lattices (CMLs) for the case of arbitrary nonlinearity of the local map and with space-shift as well as diffusion coupling. The effect of synchronization where, independently of the initial conditions, all elements of a CML acquire uniform...... dynamics is investigated and stable chaotic time behaviors, steady structures, and traveling waves are described. Finally, the bifurcations occurring under the transition from spatiotemporal chaos to chaotic synchronization and the peculiarities of CMLs with specific symmetries are discussed....
Resonance phenomena in one-dimensional grating-based structures
Directory of Open Access Journals (Sweden)
I.Ya. Yaremchuk
2017-04-01
Full Text Available Enhanced optical transmission through metallic 1-D grating-based structures has been studied using the rigorous coupled wave analysis. The results have shown that optical transmission is determined by waveguide properties of the grating slit, and there is a minimum width of slit for TE polarization, when high transmission occurs due to waveguide effect. In contrast, this limitation doesn’t exist for TM polarization, and extraordinary transmission is obtained at the sub-wavelength slit. As a result, high transmission is reached due to resonance of electromagnetic field inside the grating slit.
Ferromagnetism in undoped One-dimensional GaN Nanowires
Directory of Open Access Journals (Sweden)
K. Jeganathan
2014-05-01
Full Text Available We report an intrinsic ferromagnetism in vertical aligned GaN nanowires (NW fabricated by molecular beam epitaxy without any external catalyst. The magnetization saturates at ∼0.75 × emu/gm with the applied field of 3000 Oe for the NWs grown under the low-Gallium flux of 2.4 × 10−8 mbar. Despite a drop in saturation magnetization, narrow hysteresis loop remains intact regardless of Gallium flux. Magnetization in vertical standing GaN NWs is consistent with the spectral analysis of low-temperature photoluminescence pertaining to Ga-vacancies associated structural defects at the nanoscale.
Public Release of a One Dimensional Version of the Photon Clean Method (PCM1D)
Energy Technology Data Exchange (ETDEWEB)
Carpenter, M H; Jernigan, J G
2006-10-17
We announce the public release of a one dimensional version of the Photon Clean Method (PCM1D). This code is in the general class of 'inverse Monte Carlo' methods and is specifically designed to interoperate with the public analysis tools available from the Chandra Science Center and the HEASARC. The tool produces models of event based data on a photon by photon basis. The instrument models are based on the standard ARF and RMF fits files. The resulting models have a high number of degrees of freedom of order the number of photons detected providing an alternative analysis compared to the usual method of fitting models with only a few parameters. The original work on this method is described in ADASS 1996 (Jernigan and Vezie).
Gorelik, V. S.; Yashin, M. M.; Pudovkin, A. V.; Vodchits, A. I.
2017-11-01
The article considers optical properties (transmission and reflection) of one-dimensional photonic crystals based on mesoporous anodic aluminum oxide, with periods of crystal lattices 188 and 194 nm. A comparison of the experimentally measured reflection spectrum in the spectral region of the first stop-zone with the theoretical dependence obtained from the dispersion relation for one-dimensional photonic crystal is carried out. The angular dependence of the first stop-zone spectral positions of one-dimensional photonic crystal is established. The authors analyze the possibility of applications of mesoporous one-dimensional photonic crystals based on aluminum oxide as the selective narrowband filters and mirrors.
Half-range acceleration for one-dimensional transport problems
Energy Technology Data Exchange (ETDEWEB)
Zika, M.R. [Lawrence Livermore National Lab., CA (United States); Larsen, E.W. [Univ. of Michigan, Ann Arbor, MI (United States)
1998-12-31
Researchers have devoted considerable effort to developing acceleration techniques for transport iterations in highly diffusive problems. The advantages and disadvantages of source iteration, rebalance, diffusion synthetic acceleration (DSA), transport synthetic acceleration (TSA), and projection acceleration methods are documented in the literature and will not be discussed here except to note that no single method has proven to be applicable to all situations. Here, the authors describe a new acceleration method that is based solely on transport sweeps, is algebraically linear (and is therefore amenable to a Fourier analysis), and yields a theoretical spectral radius bounded by one-third for all cases. This method does not introduce spatial differencing difficulties (as is the case for DSA) nor does its theoretical performance degrade as a function of mesh and material properties (as is the case for TSA). Practical simulations of the new method agree with the theoretical predictions, except for scattering ratios very close to unity. At this time, they believe that the discrepancy is due to the effect of boundary conditions. This is discussed further.
[Study of the reliability in one dimensional size measurement with digital slit lamp microscope].
Wang, Tao; Qi, Chaoxiu; Li, Qigen; Dong, Lijie; Yang, Jiezheng
2010-11-01
To study the reliability of digital slit lamp microscope as a tool for quantitative analysis in one dimensional size measurement. Three single-blinded observers acquired and repeatedly measured the images with a size of 4.00 mm and 10.00 mm on the vernier caliper, which simulatated the human eye pupil and cornea diameter under China-made digital slit lamp microscope in the objective magnification of 4 times, 10 times, 16 times, 25 times, 40 times and 4 times, 10 times, 16 times, respectively. The correctness and precision of measurement were compared. The images with 4 mm size were measured by three investigators and the average values were located between 3.98 to 4.06. For the images with 10.00 mm size, the average values fell within 10.00 ~ 10.04. Measurement results of 4.00 mm images showed, except A4, B25, C16 and C25, significant difference was noted between the measured value and the true value. Regarding measurement results of 10.00 mm iamges indicated, except A10, statistical significance was found between the measured value and the true value. In terms of comparing the results of the same size measured at different magnifications by the same investigator, except for investigators A's measurements of 10.00 mm dimension, the measurement results by all the remaining investigators presented statistical significance at different magnifications. Compared measurements of the same size with different magnifications, measurements of 4.00 mm in 4-fold magnification had no significant difference among the investigators', the remaining results were statistically significant. The coefficient of variation of all measurement results were less than 5%; as magnification increased, the coefficient of variation decreased. The measurement of digital slit lamp microscope in one-dimensional size has good reliability,and should be performed for reliability analysis before used for quantitative analysis to reduce systematic errors.
Simulation of plume-plasma expansion with one-dimensional Particle-in-Cell
Gonzalez, C. A.; Arteaga, J. A.; Gomez, Y. H.; Osorio, J.; Jaramillo, J. A.; Riascos, H.
2012-06-01
In this work we present the analysis of the dynamic of the expansion of Al Plasma produced by Nd:YAG laser (1064 nm, 500mJ, 9 ms, 10 Hz) in vacuum. To study the Coulomb interaction between the particles of the initial states of the plasma expansion, we use the one dimensional Particle-in-Cell method (PIC) and finite difference method. We considered an ideal model, that is, we assume that the plasma is in a local thermal equilibrium, the ablated particles have a fixed temperature and a constant evaporation flux (J) from the aluminium surface. To obtain more accurate results we use high computing exploiting the parallelization of this kind of algorithms. The mean velocity and particles densities are determined for different times of the expansion.
SIRIUS - A one-dimensional multigroup analytic nodal diffusion theory code
Energy Technology Data Exchange (ETDEWEB)
Forslund, P. [Westinghouse Atom AB, Vaesteraas (Sweden)
2000-09-01
In order to evaluate relative merits of some proposed intranodal cross sections models, a computer code called Sirius has been developed. Sirius is a one-dimensional, multigroup analytic nodal diffusion theory code with microscopic depletion capability. Sirius provides the possibility of performing a spatial homogenization and energy collapsing of cross sections. In addition a so called pin power reconstruction method is available for the purpose of reconstructing 'heterogeneous' pin qualities. consequently, Sirius has the capability of performing all the calculations (incl. depletion calculations) which are an integral part of the nodal calculation procedure. In this way, an unambiguous numerical analysis of intranodal cross section models is made possible. In this report, the theory of the nodal models implemented in sirius as well as the verification of the most important features of these models are addressed.
One-dimensional classical diffusion in a random force field with weakly concentrated absorbers
Texier, C.; Hagendorf, C.
2009-05-01
A one-dimensional model of classical diffusion in a random force field with a weak concentration ρ of absorbers is studied. The force field is taken as a Gaussian white noise with langphi(x)rang=0 and langphi(x)phi(x')rang=g δ(x- x'). Our analysis relies on the relation between the Fokker-Planck operator and a quantum Hamiltonian in which absorption leads to breaking of supersymmetry. Using a Lifshits argument, it is shown that the average return probability is a power law \\langle {P(x,t\\vert x,0)} \\rangle \\sim t^{-\\sqrt{2\\rho/g}} (to be compared with the usual Lifshits exponential decay exp-(ρ2t)1/3 in the absence of the random force field). The localisation properties of the underlying quantum Hamiltonian are discussed as well.
Stationary bottom generated velocity fluctuations in one-dimensional open channel flow
de Jong, B.
1994-01-01
Statistical characteristics are calculated for stationary velocity fluctuations in a one-dimensional open channel flow with a given vertical velocity profile and with one-dimensional irregular bottom waves, characterized by a spectral density function. The calculations are based on an approximate
Global stability in some one-dimensional non-autonomous discrete periodic population models
Luís, Rafael; Rodrigues, Elias
2016-01-01
For some one-dimensional discrete-time autonomous population models, local stability implies global stability of the positive equilibrismo point. One of the known techniques is the enveloping method. In this paper we extend the enveloping method to one single periodic population models. We show that, under certain conditions, "individual enveloping" implies "periodic enveloping" in one-dimensional periodic population models.
Diffusion related isotopic fractionation effects with one-dimensional advective–dispersive transport
Energy Technology Data Exchange (ETDEWEB)
Xu, Bruce S. [Civil Engineering Department, University of Toronto, 35 St George Street, Toronto, ON M5S 1A4 (Canada); Lollar, Barbara Sherwood [Earth Sciences Department, University of Toronto, 22 Russell Street, Toronto, ON M5S 3B1 (Canada); Passeport, Elodie [Civil Engineering Department, University of Toronto, 35 St George Street, Toronto, ON M5S 1A4 (Canada); Chemical Engineering and Applied Chemistry Department, University of Toronto, 200 College Street, Toronto, ON M5S 3E5 (Canada); Sleep, Brent E., E-mail: sleep@ecf.utoronto.ca [Civil Engineering Department, University of Toronto, 35 St George Street, Toronto, ON M5S 1A4 (Canada)
2016-04-15
Aqueous phase diffusion-related isotope fractionation (DRIF) for carbon isotopes was investigated for common groundwater contaminants in systems in which transport could be considered to be one-dimensional. This paper focuses not only on theoretically observable DRIF effects in these systems but introduces the important concept of constraining “observable” DRIF based on constraints imposed by the scale of measurements in the field, and on standard limits of detection and analytical uncertainty. Specifically, constraints for the detection of DRIF were determined in terms of the diffusive fractionation factor, the initial concentration of contaminants (C{sub 0}), the method detection limit (MDL) for isotopic analysis, the transport time, and the ratio of the longitudinal mechanical dispersion coefficient to effective molecular diffusion coefficient (D{sub mech}/D{sub eff}). The results allow a determination of field conditions under which DRIF may be an important factor in the use of stable carbon isotope measurements for evaluation of contaminant transport and transformation for one-dimensional advective–dispersive transport. This study demonstrates that for diffusion-dominated transport of BTEX, MTBE, and chlorinated ethenes, DRIF effects are only detectable for the smaller molar mass compounds such as vinyl chloride for C{sub 0}/MDL ratios of 50 or higher. Much larger C{sub 0}/MDL ratios, corresponding to higher source concentrations or lower detection limits, are necessary for DRIF to be detectable for the higher molar mass compounds. The distance over which DRIF is observable for VC is small (less than 1 m) for a relatively young diffusive plume (< 100 years), and DRIF will not easily be detected by using the conventional sampling approach with “typical” well spacing (at least several meters). With contaminant transport by advection, mechanical dispersion, and molecular diffusion this study suggests that in field sites where D{sub mech}/D{sub eff} is
Comparisons between thermodynamic and one-dimensional combustion models of spark-ignition engines
Ramos, J. I.
1986-01-01
Results from a one-dimensional combustion model employing a constant eddy diffusivity and a one-step chemical reaction are compared with those of one-zone and two-zone thermodynamic models to study the flame propagation in a spark-ignition engine. One-dimensional model predictions are found to be very sensitive to the eddy diffusivity and reaction rate data. The average mixing temperature found using the one-zone thermodynamic model is higher than those of the two-zone and one-dimensional models during the compression stroke, and that of the one-dimensional model is higher than those predicted by both thermodynamic models during the expansion stroke. The one-dimensional model is shown to predict an accelerating flame even when the front approaches the cold cylinder wall.
One-dimensional low spatial frequency LIPSS with rotating orientation on fused silica
Energy Technology Data Exchange (ETDEWEB)
Schwarz, Simon, E-mail: simon.schwarz@h-ab.de; Rung, Stefan; Hellmann, Ralf
2017-07-31
Highlights: • Generation of one-dimensional low spatial frequency LIPSS on transparent material. • Varying the angle of incidence results in a rotation of the one-dimensional LSFL. • Rotation angle of LSFL decreases with increasing the applied fluence. • Orientation of the LSFL is mirror-inverted when reversing the scanning direction. - Abstract: We report on the generation of one-dimensional low spatial frequency LIPSS on transparent material. The influence of the applied laser fluence and angle of incidence on the periodicity, orientation and quality of the one-dimensional low spatial frequency LIPSS is investigated, facilitating the generation of highly uniform LIPSS alongside a line. Most strikingly, however, we observe a previously unreported effect of a pronounced rotation of the one-dimensional low spatial frequency LIPSS for varying angle of incidence upon inclined laser irradiation.
Vibrational spectroscopy and analysis of pseudo-tetrahedral complexes with metal imido bonds.
Mehn, Mark P; Brown, Steven D; Jenkins, David M; Peters, Jonas C; Que, Lawrence
2006-09-04
A number of assignments have been previously posited for the metal-nitrogen stretch (nu(M-NR)), the N-R stretch (nu(MN-R)), and possible ligand deformation modes associated with terminally bound imides. Here we examine mononuclear iron(III) and cobalt(III) imido complexes of the monoanionic tridentate ligand [PhBP3] ([PhBP3] = [PhB(CH2PPh2)3]-) to clarify the vibrational features for these trivalent metal imides. We report the structures of [PhBP3]FeNtBu and [PhBP3]CoNtBu. Pseudo-tetrahedral metal imides of these types exhibit short bond lengths (ca. 1.65 A) and nearly linear angles about the M-N-C linkages, indicative of multiple bond character. Furthermore, these compounds give rise to intense, low-energy visible absorptions. Both the position and the intensity of the optical bands in the [PhBP3]MNR complexes depend on whether the substituent is an alkyl or aryl group. Excitation into the low-energy bands of [PhBP3]FeNtBu gives rise to two Raman features at 1104 and 1233 cm(-1), both of which are sensitive to 15N and 2H labeling. The isotope labeling suggests the 1104 cm(-1) mode has the greatest Fe-N stretching character, while the 1233 cm(-1) mode is affected to a lesser extent by (15)N substitution. The spectra of the deuterium-labeled imides further support this assertion. The data demonstrate that the observed peaks are not simple diatomic stretching modes but are extensively coupled to the vibrations of the ancillary organic group. Therefore, describing these complexes as simple diatomic or even triatomic oscillators is an oversimplification. Analogous studies of the corresponding cobalt(III) complex lead to a similar set of isotopically sensitive resonances at 1103 and 1238 cm(-1), corroborating the assignments made in the iron imides. Very minimal changes in the vibrational frequencies are observed upon replacement of cobalt(III) for iron(III), suggesting similar force constants for the two compounds. This is consistent with the previously proposed
Andree, Karl B.; Fernández-Tejedor, Margarita; Elandaloussi, Laurence M.; Quijano-Scheggia, Sonia; Sampedro, Nagore; Garcés, Esther; Camp, Jordi; Diogène, Jorge
2011-01-01
The frequency and intensity of Pseudo-nitzschia spp. blooms along the coast of Catalonia have been increasing over the past 20 years. As species from this genus that are documented as toxigenic have been found in local waters, with both toxic and nontoxic species cooccurring in the same bloom, there is a need to develop management tools for discriminating the difference. Currently, differentiation of toxic and nontoxic species requires time-consuming electron microscopy to distinguish taxonomic features that would allow identification as to species, and cryptic species can still remain misidentified. In this study, cells of Pseudo-nitzschia from clonal cultures isolated from seawater were characterized to their species identity using scanning electron microscopy, and subsamples of each culture were used to create an internal transcribed spacer 1 (ITS-1), 5.8S, and ITS-2 ribosomal DNA database for development of species-specific quantitative PCR (qPCR) assays. Once developed, these qPCR assays were applied to field samples collected over a 2-year period in Alfaques Bay in the northwestern Mediterranean Sea to evaluate the possibility of a comprehensive surveillance for all Pseudo-nitzschia spp. using molecular methods to supplement optical microscopy, which can discern taxonomy only to the genus level within this taxon. Total Pseudo-nitzschia cell density was determined by optical microscopy from water samples collected weekly and compared to results obtained from the sum of eight Pseudo-nitzschia species-specific qPCR assays using duplicate samples. Species-specific qPCR followed by melt curve analysis allowed differentiation of amplicons and identification of false positives, and results correlated well with the total Pseudo-nitzschia cell counts from optical microscopy. PMID:21193668
Das, S.; Banu, A.S.; Jana, R.N.; Makinde, O.D.
2015-01-01
This paper is concerned with the entropy generation in a magnetohydrodynamic (MHD) pseudo-plastic nanofluid flow through a porous channel with convective heating. Three different types of nanoparticles, namely copper, aluminum oxide and titanium dioxide are considered with pseudo-plastic carboxymethyl cellulose (CMC)–water used as base fluids. The governing equations are solved numerically by shooting technique coupled with Runge–Kutta scheme. The effects of the pertinent parameters on the fl...
DEFF Research Database (Denmark)
Sing, M.; Schwingenschlögl, U.; Claessen, R.
2003-01-01
We have thoroughly characterized the surfaces of the organic charge-transfer salts TTF-TCNQ and (TMTSF)(2)PF6 which are generally acknowledged as prototypical examples of one-dimensional conductors. In particular x-ray-induced photoemission spectroscopy turns out to be a valuable nondestructive...... diagnostic tool. We show that the observation of generic one-dimensional signatures in photoemission spectra of the valence band close to the Fermi level can be strongly affected by surface effects. Especially, great care must be exercised taking evidence for an unusual one-dimensional many-body state...
Nanoscale Si template for the growth of self-organized one-dimensional nanostructures
Masson, Laurence; Sahaf, Houda; Amsalem, Patrick; Dettoni, Florent; Moyen, Eric; Koch, Norbert; Hanbücken, Margrit
2013-02-01
Through silicon deposition onto the silver (1 1 0) surface, we have fabricated in a one-step process a highly perfect nanoscale template consisting of a self-assembled Si nanostripe array with a pitch of 2 nm, covering uniformly the entire surface. Scanning tunneling microscopy investigations show that this system can be used, in a very simple way, as a template for the growth of identical highly ordered one-dimensional nanostructures. The adsorption of Co at room temperature and C60 at 190 °C gives rise to the growth of self-organized one-dimensional nanostructures reproducing the one-dimensional pattern of the Si template.
Kondo, Jiro; Westhof, Eric
2011-01-01
Nucleotide bases are recognized by amino acid residues in a variety of DNA/RNA binding and nucleotide binding proteins. In this study, a total of 446 crystal structures of nucleotide–protein complexes are analyzed manually and pseudo pairs together with single and bifurcated hydrogen bonds observed between bases and amino acids are classified and annotated. Only 5 of the 20 usual amino acid residues, Asn, Gln, Asp, Glu and Arg, are able to orient in a coplanar fashion in order to form pseudo pairs with nucleotide bases through two hydrogen bonds. The peptide backbone can also form pseudo pairs with nucleotide bases and presents a strong bias for binding to the adenine base. The Watson–Crick side of the nucleotide bases is the major interaction edge participating in such pseudo pairs. Pseudo pairs between the Watson–Crick edge of guanine and Asp are frequently observed. The Hoogsteen edge of the purine bases is a good discriminatory element in recognition of nucleotide bases by protein side chains through the pseudo pairing: the Hoogsteen edge of adenine is recognized by various amino acids while the Hoogsteen edge of guanine is only recognized by Arg. The sugar edge is rarely recognized by either the side-chain or peptide backbone of amino acid residues. PMID:21737431
Kondo, Jiro; Westhof, Eric
2011-10-01
Nucleotide bases are recognized by amino acid residues in a variety of DNA/RNA binding and nucleotide binding proteins. In this study, a total of 446 crystal structures of nucleotide-protein complexes are analyzed manually and pseudo pairs together with single and bifurcated hydrogen bonds observed between bases and amino acids are classified and annotated. Only 5 of the 20 usual amino acid residues, Asn, Gln, Asp, Glu and Arg, are able to orient in a coplanar fashion in order to form pseudo pairs with nucleotide bases through two hydrogen bonds. The peptide backbone can also form pseudo pairs with nucleotide bases and presents a strong bias for binding to the adenine base. The Watson-Crick side of the nucleotide bases is the major interaction edge participating in such pseudo pairs. Pseudo pairs between the Watson-Crick edge of guanine and Asp are frequently observed. The Hoogsteen edge of the purine bases is a good discriminatory element in recognition of nucleotide bases by protein side chains through the pseudo pairing: the Hoogsteen edge of adenine is recognized by various amino acids while the Hoogsteen edge of guanine is only recognized by Arg. The sugar edge is rarely recognized by either the side-chain or peptide backbone of amino acid residues.
Theory of optimal beam splitting by phase gratings. I. One-dimensional gratings.
Romero, Louis A; Dickey, Fred M
2007-08-01
We give an analytical basis for the theory of optimal beam splitting by one-dimensional gratings. In particular, we use methods from the calculus of variations to derive analytical expressions for the optimal phase function.
Goloviznin, V. M.; Kanaev, A. A.
2012-03-01
The CABARET computational algorithm is generalized to one-dimensional scalar quasilinear hyperbolic partial differential equations with allowance for inequality constraints on the solution. This generalization can be used to analyze seepage of liquid radioactive wastes through the unsaturated zone.
Reconstruction of gyrotropic phase-space distributions from one-dimensional projections
DEFF Research Database (Denmark)
Egedal, J.; Bindslev, H.
2004-01-01
This paper describes mathematical tools applicable to the reconstruction of anisotropic velocity distributions through the unfolding of data coming from techniques like collective Thomson scattering or laser induced fluorescence, where one-dimensional projections of the velocity space along...
Neutron and photon (light) scattering on solitons in the quasi-one-dimensional magnetics
Abdulloev, K O
1999-01-01
The general expression we have found earlier for the dynamics form-factor is used to analyse experiments on the neutron and photon (light) scattering by the gas of solitons in quasi-one-dimensional magnetics (Authors)
Modeling of an one-dimensional harmonious ostsillyator in the environment of MATLAB/SIMULINK
Directory of Open Access Journals (Sweden)
B. A. Golodenko
2012-01-01
Full Text Available Results of modeling one-dimensional harmonious oscillator are stated by means MATLAB/SIMULINK. On example oscillators, possible approaches and technologies of construction of models of real physical systems based on their mathematical description are shown.
Small amplitude periodic solutions in time for one-dimensional nonlinear wave equations
Liu, Zhenjie
2017-09-01
This paper is devoted to the construction of solutions for one-dimensional wave equations with Dirichlet or Neumann boundary conditions by means of a Nash-Moser iteration scheme, for a large set of frequencies.
One-dimensional arrangement of nanoparticles utilizing the V-groove and cage shaped proteins
Ban, Takahiko; Uenuma, Mutsunori; Migita, Shinji; Okamoto, Naofumi; Ishikawa, Yasuaki; Uraoka, Yukiharu; Yamashita, Ichiro; Yamamoto, Shin-ichi
2017-06-01
The one-dimensional arrangement of nanoparticles (NPs) was performed using a V-groove and ferritins as spherical shell proteins. The V-groove was synthesized by lithography and anisotropic etching of a Si substrate. Ferritin has an outer diameter of 12 nm and an inner diameter of 6 nm, and various inorganic substances can be formed into the cavity. In this study, iron oxide, cobalt oxide, and indium oxide cores were used. The surface potential of ferritin can be changed by genetic modification. Particularly, by using Fer8-K98E, NPs could be arranged one-dimensionally onto the bottom of the V-groove. In addition, we succeeded in selectively forming a one-dimensional array of one layer, two layers, and three layers by changing the protein concentration. This experiment is expected to be applicable to various one-dimensional devices.
A One-Dimensional Mean Wind and Turbulence Model for a Uniform Urban Canopy
National Research Council Canada - National Science Library
Yee, Eugene
2000-01-01
A fully analytical model for the prediction of the one-dimensional mean wind speed, kinematic shear stress, turbulence kinetic energy, and velocity variances in a horizontally homogeneous canopy is described...
Drescher, U; Koschate, J; Schiffer, T; Schneider, S; Hoffmann, U
2017-06-01
The aim of the study was to compare the kinetics responses of heart rate (HR), pulmonary (V˙O2pulm) and predicted muscular (V˙O2musc) oxygen uptake between two different pseudo-random binary sequence (PRBS) work rate (WR) amplitudes both below anaerobic threshold. Eight healthy individuals performed two PRBS WR protocols implying changes between 30W and 80W and between 30W and 110W. HR and V˙O2pulm were measured beat-to-beat and breath-by-breath, respectively. V˙O2musc was estimated applying the approach of Hoffmann et al. (Eur J Appl Physiol 113: 1745-1754, 2013) considering a circulatory model for venous return and cross-correlation functions (CCF) for the kinetics analysis. HR and V˙O2musc kinetics seem to be independent of WR intensity (p>0.05). V˙O2pulm kinetics show prominent differences in the lag of the CCF maximum (39±9s; 31±4s; pkinetics remain unchanged. Copyright © 2017 Elsevier B.V. All rights reserved.
Jeong, Gu-Min; Nghia, Nguyen Trong; Choi, Sang-Il
2015-01-01
In this paper, we present a pseudo optimization method for electronic nose (e-nose) data using region selection with feature feedback based on regularized linear discriminant analysis (R-LDA) to enhance the performance and cost functions of an e-nose system. To implement cost- and performance-effective e-nose systems, the number of channels, sampling time and sensing time of the e-nose must be considered. We propose a method to select both important channels and an important time-horizon by analyzing e-nose sensor data. By extending previous feature feedback results, we obtain a two-dimensional discriminant information map consisting of channels and time units by reverse mapping the feature space to the data space based on R-LDA. The discriminant information map enables optimal channels and time units to be heuristically selected to improve the performance and cost functions. The efficacy of the proposed method is demonstrated experimentally for different volatile organic compounds. In particular, our method is both cost and performance effective for the real implementation of e-nose systems. PMID:25559000
One-dimensional Z-scheme TiO2/WO3/Pt heterostructures for enhanced hydrogen generation
Gao, Hongqing; Zhang, Peng; Hu, Junhua; Pan, Jimin; Fan, Jiajie; Shao, Guosheng
2017-01-01
One-dimensional Z-scheme TiO2/WO3/Pt heterostructures were fabricated by integrating a facile electrospinning technique and subsequent annealing in air. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and UV-vis diffuse reflectance spectroscopy, were used to characterize the as-fabricated samples. The results showed that the H2-generation of the as-fabricated one-dimensional Z-scheme TiO2/WO3/Pt heterostructures (S2) was greatly enhanced compared with pure TiO2 nanofibers (S0) and TiO2/WO3 nanofibers (S1). The enhanced photocatalyst activities were mainly attributed to the solid-state Z-scheme photosynthetic heterojunction system with Pt nanoparticle as an electron collector and WO3 as a hole collector, leading to effective charge separation on these semiconductors, which were evidenced by electrochemical impedance spectroscopy (EIS) and photocurrent analysis.
Roy, Dibyendu; Dhar, Abhishek
2006-01-01
We present an extension of the work of D'Amato and Pastawski on electron transport in a one-dimensional conductor modeled by the tight binding lattice Hamiltonian and in which inelastic scattering is incorporated by connecting each site of the lattice to one-dimensional leads. This model incorporates B\\"uttiker's original idea of dephasing probes. Here we consider finite temperatures and study both electrical and heat transport across a chain with applied chemical potential and temperature gr...
Cassidy, Amy; Grigorenko, Ilya; Haas, Stephan
2008-01-01
We investigate theoretically the formation of collective excitations in atomic scale quasi-one dimensional metallic nanostructures. The response of the system is calculated within the linear response theory and random phase approximation. For uniform nanostructures a transition from quantum single particle excitations to classical plasmon scaling is observed, depending on the system length and electron density. We find crucial differences in the scaling behavior for quasi-one dimensional and ...
One- and Two- Magnon Excitations in a One-Dimensional Antiferromagnet in a Magnetic Field
DEFF Research Database (Denmark)
Heilmann, I.U.; Kjems, Jørgen; Endoh, Y.
1981-01-01
We have carried out a comprehensive experimental and theoretical study of the inelastic scattering in the one-dimensional near-Heisenberg antiferromagnet (CD3)4NMnCl3 (TMMC) at low temperatures, 0.3......We have carried out a comprehensive experimental and theoretical study of the inelastic scattering in the one-dimensional near-Heisenberg antiferromagnet (CD3)4NMnCl3 (TMMC) at low temperatures, 0.3...
Effective one-dimensional images of arterial trees in the cardiovascular system
Kozlov, V. A.; Nazarov, S. A.
2017-03-01
An exponential smallness of the errors in the one-dimensional model of the Stokes flow in a branching thin vessel with rigid walls is achieved by introducing effective lengths of the one-dimensional image of internodal fragments of vessels. Such lengths are eluated through the pressure-drop matrix at each node describing the boundary-layer phenomenon. The medical interpretation and the accessible generalizations of the result, in particular, for the Navier-Stokes equations are presented.
Solution to the one-dimensional telegrapher's equation subject to a backreaction boundary condition
Prüstel, Thorsten; Meier-Schellersheim, Martin
2013-01-01
We discuss solutions of the one-dimensional telegrapher's equation in the presence of boundary conditions. We revisit the case of a radiation boundary condition and obtain an alternative expression for the already known Green's function. Furthermore, we formulate a backreaction boundary condition, which has been widely used in the context of diffusion-controlled reversible reactions, for a one-dimensional telegrapher's equation and derive the corresponding Green's function.
Effective one-dimensionality of universal ac hopping conduction in the extreme disorder limit
DEFF Research Database (Denmark)
Dyre, Jeppe; Schrøder, Thomas
1996-01-01
A phenomenological picture of ac hopping in the symmetric hopping model (regular lattice, equal site energies, random energy barriers) is proposed according to which conduction in the extreme disorder limit is dominated by essentially one-dimensional "percolation paths." Modeling a percolation pa...... as strictly one dimensional with a sharp jump rate cutoff leads to an expression for the universal ac conductivity that fits computer simulations in two and three dimensions better than the effective medium approximation....
Pseudo-chaotic oscillations in CRISPR-virus coevolution predicted by bifurcation analysis.
Berezovskaya, Faina S; Wolf, Yuri I; Koonin, Eugene V; Karev, Georgy P
2014-07-02
The CRISPR-Cas systems of adaptive antivirus immunity are present in most archaea and many bacteria, and provide resistance to specific viruses or plasmids by inserting fragments of foreign DNA into the host genome and then utilizing transcripts of these spacers to inactivate the cognate foreign genome. The recent development of powerful genome engineering tools on the basis of CRISPR-Cas has sharply increased the interest in the diversity and evolution of these systems. Comparative genomic data indicate that during evolution of prokaryotes CRISPR-Cas loci are lost and acquired via horizontal gene transfer at high rates. Mathematical modeling and initial experimental studies of CRISPR-carrying microbes and viruses reveal complex coevolutionary dynamics. We performed a bifurcation analysis of models of coevolution of viruses and microbial host that possess CRISPR-Cas hereditary adaptive immunity systems. The analyzed Malthusian and logistic models display complex, and in particular, quasi-chaotic oscillation regimes that have not been previously observed experimentally or in agent-based models of the CRISPR-mediated immunity. The key factors for the appearance of the quasi-chaotic oscillations are the non-linear dependence of the host immunity on the virus load and the partitioning of the hosts into the immune and susceptible populations, so that the system consists of three components. Bifurcation analysis of CRISPR-host coevolution model predicts complex regimes including quasi-chaotic oscillations. The quasi-chaotic regimes of virus-host coevolution are likely to be biologically relevant given the evolutionary instability of the CRISPR-Cas loci revealed by comparative genomics. The results of this analysis might have implications beyond the CRISPR-Cas systems, i.e. could describe the behavior of any adaptive immunity system with a heritable component, be it genetic or epigenetic. These predictions are experimentally testable. This manuscript was reviewed by
Boissonneault, Katie Rose; Henningsen, Brooks M; Bates, Stephen S; Robertson, Deborah L; Milton, Sean; Pelletier, Jerry; Hogan, Deborah A; Housman, David E
2013-11-01
Pseudo-nitzschia multiseries Hasle (Hasle) (Ps-n) is distinctive among the ecologically important marine diatoms because it produces the neurotoxin domoic acid. Although the biology of Ps-n has been investigated intensely, the characterization of the genes and biochemical pathways leading to domoic acid biosynthesis has been limited. To identify transcripts whose levels correlate with domoic acid production, we analyzed Ps-n under conditions of high and low domoic acid production by cDNA microarray technology and reverse-transcription quantitative PCR (RT-qPCR) methods. Our goals included identifying and validating robust reference genes for Ps-n RNA expression analysis under these conditions. Through microarray analysis of exponential- and stationary-phase cultures with low and high domoic acid production, respectively, we identified candidate reference genes whose transcripts did not vary across conditions. We tested eleven potential reference genes for stability using RT-qPCR and GeNorm analyses. Our results indicated that transcripts encoding JmjC, dynein, and histone H3 proteins were the most suitable for normalization of expression data under conditions of silicon-limitation, in late-exponential through stationary phase. The microarray studies identified a number of genes that were up- and down-regulated under toxin-producing conditions. RT-qPCR analysis, using the validated controls, confirmed the up-regulation of transcripts predicted to encode a cycloisomerase, an SLC6 transporter, phosphoenolpyruvate carboxykinase, glutamate dehydrogenase, a small heat shock protein, and an aldo-keto reductase, as well as the down-regulation of a transcript encoding a fucoxanthin-chlorophyll a-c binding protein, under these conditions. Our results provide a strong basis for further studies of RNA expression levels in Ps-n, which will contribute to our understanding of genes involved in the production and release of domoic acid, an important neurotoxin that affects human
A one-dimensional arterial network model for bypass graft assessment.
Ghigo, A R; Abou Taam, S; Wang, X; Lagrée, P-Y; Fullana, J-M
2017-05-01
We propose an arterial network model based on one-dimensional hemodynamic equations to study the behavior of different vascular surgical bypass grafts in the case of an arterial occlusive pathology: a stenosis of the Right Iliac artery. We investigate the performances of three different bypass grafts (Aorto-Femoral, Axillo-Femoral and cross-over Femoral) depending on the degree of obstruction of the stenosis. Numerical simulations show that all bypass grafts are efficient since we retrieve in each case the healthy hemodynamics downstream of the stenosed region while ensuring at the same time a global healthy circulation. We analyze in detail the behavior of the Axillo-Femoral bypass graft by performing hundreds of simulations where we vary the values of its Young's modulus [0.1-50 MPa] and radius [0.01-5 cm]. Our analysis shows that Young's modulus and radius of commercial bypass grafts are optimal in terms of hemodynamic considerations. Our numerical findings prove that this model approach can be used to optimize or plan patient-specific surgeries, to numerically assess the viability of bypass grafts and to perform parametric analysis and error propagation evaluations by running extensive simulations. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.
Czech Academy of Sciences Publication Activity Database
Mesiar, Radko; Li, J.; Pap, E.
2013-01-01
Roč. 54, č. 3 (2013), s. 357-364 ISSN 0888-613X R&D Projects: GA ČR GAP402/11/0378 Institutional support: RVO:67985556 Keywords : concave integral * pseudo-addition * pseudo- multiplication Subject RIV: BA - General Mathematics Impact factor: 1.977, year: 2013 http://library.utia.cas.cz/separaty/2013/E/mesiar-discrete pseudo-integrals. pdf
One-Dimensional Vacuum Steady Seepage Model of Unsaturated Soil and Finite Difference Solution
Directory of Open Access Journals (Sweden)
Feng Huang
2017-01-01
Full Text Available Vacuum tube dewatering method and light well point method have been widely used in engineering dewatering and foundation treatment. However, there is little research on the calculation method of unsaturated seepage under the effect of vacuum pressure which is generated by the vacuum well. In view of this, the one-dimensional (1D steady seepage law of unsaturated soil in vacuum field has been analyzed based on Darcy’s law, basic equations, and finite difference method. First, the gravity drainage ability is analyzed. The analysis presents that much unsaturated water can not be drained off only by gravity effect because of surface tension. Second, the unsaturated vacuum seepage equations are built up in conditions of flux boundary and waterhead boundary. Finally, two examples are analyzed based on the relationship of matric suction and permeability coefficient after boundary conditions are determined. The results show that vacuum pressure will significantly enhance the drainage ability of unsaturated water by improving the hydraulic gradient of unsaturated water.
Vovchenko, Ludmila; Lozitsky, Oleg; Sagalianov, Igor; Matzui, Ludmila; Launets, Vilen
2017-04-01
This work presents the results of computer modeling and experimental measurements of microwave transmission properties for one-dimensional periodic multi-layered photonic structures (PCs), composed of epoxy layers and composite layers filled with nanocarbon particles—multi-walled carbon nanotubes and graphite nanoplatelets. The results show that the characteristics of observed photonic band gaps in transmission spectra of PC can be controlled by varying the parameters of layers, namely, the complex permittivity and the layer thickness. It was found that the insertion of the defects (for instance, magnetic layer) into photonic structure can change the EMR transmission spectrum. The comparative analysis of EMR transmission spectra for investigated photonic structures has showed good agreement between the experimental and simulated data. It was found that EMR absorption in composite layers of photonic structures shifts the transmission spectra to the smaller values of EMR transmission index and reduces the sharpness of photonic band gaps. Thus, by changing the parameters of composite layers in photonic structure, we can obtain the tunable photonic band gaps, necessary for technological applications in devices, capable of storing, guiding, and filtering microwaves.
Observation of high Tc one dimensional superconductivity in 4 angstrom carbon nanotube arrays
Zhang, Bing
2017-02-14
The only known approach to fabricate large, uniform arrays of 4-Å single wall carbon nanotubes (SWNTs) is by using zeolite crystals as the template, in which the nanotubes are formed by chemical vapor deposition inside the linear channels of the AlPO-5 (AFI for short) zeolite. However, up to now the pore filling factor has been very low, as evidenced by the weight percentage of carbon in thermal gravimetric analysis (TGA) measurements. In this work, we show that by using a new, micro-platelet AFI crystals as the template, combined with the use of a new CVD process, we can increase the TGA result to 22.5wt%, which translates to a pore filling factor of 91%. We have observed one dimensional (1D) superconductivity in such samples. The temperature dependence of resistance shows a smooth decreasing trend below 60 K, and the differential resistance displays a gap that disappears above the 1D superconducting initiation temperature. The observed behaviour is shown to agree very well with the theoretical predictions of 1D superconductivity.
A one-dimensional continuum elastic model for membrane-embedded gramicidin dimer dissociation.
Directory of Open Access Journals (Sweden)
Joseph N Stember
Full Text Available Membrane elastic properties, which are subject to alteration by compounds such as cholesterol, lipid metabolites and other amphiphiles, as well as pharmaceuticals, can have important effects on membrane proteins. A useful tool for measuring some of these effects is the gramicidin A channels, which are formed by transmembrane dimerization of non-conducting subunits that reside in each bilayer leaflet. The length of the conducting channels is less than the bilayer thickness, meaning that channel formation is associated with a local bilayer deformation. Electrophysiological studies have shown that the dimer becomes increasingly destabilized as the hydrophobic mismatch between the channel and the host bilayer increases. That is, the bilayer imposes a disjoining force on the channel, which grows larger with increasing hydrophobic mismatch. The energetic analysis of the channel-bilayer coupling is usually pursued assuming that each subunit, as well as the subunit-subunit interface, is rigid. Here we relax the latter assumption and explore how the bilayer junction responds to changes in this disjoining force using a simple one-dimensional energetic model, which reproduces key features of the bilayer regulation of gramicidin channel lifetimes.
Observation of high Tc one dimensional superconductivity in 4 angstrom carbon nanotube arrays
Directory of Open Access Journals (Sweden)
Bing Zhang
2017-02-01
Full Text Available The only known approach to fabricate large, uniform arrays of 4-Å single wall carbon nanotubes (SWNTs is by using zeolite crystals as the template, in which the nanotubes are formed by chemical vapor deposition inside the linear channels of the AlPO4-5 (AFI for short zeolite. However, up to now the pore filling factor has been very low, as evidenced by the weight percentage of carbon in thermal gravimetric analysis (TGA measurements. In this work, we show that by using a new, micro-platelet AFI crystals as the template, combined with the use of a new CVD process, we can increase the TGA result to 22.5wt%, which translates to a pore filling factor of 91%. We have observed one dimensional (1D superconductivity in such samples. The temperature dependence of resistance shows a smooth decreasing trend below 60 K, and the differential resistance displays a gap that disappears above the 1D superconducting initiation temperature. The observed behaviour is shown to agree very well with the theoretical predictions of 1D superconductivity.
Self-similar solutions of the one-dimensional Landau-Lifshitz-Gilbert equation
Gutiérrez, Susana; de Laire, André
2015-05-01
We consider the one-dimensional Landau-Lifshitz-Gilbert (LLG) equation, a model describing the dynamics for the spin in ferromagnetic materials. Our main aim is the analytical study of the bi-parametric family of self-similar solutions of this model. In the presence of damping, our construction provides a family of global solutions of the LLG equation which are associated with discontinuous initial data of infinite (total) energy, and which are smooth and have finite energy for all positive times. Special emphasis will be given to the behaviour of this family of solutions with respect to the Gilbert damping parameter. We would like to emphasize that our analysis also includes the study of self-similar solutions of the Schrödinger map and the heat flow for harmonic maps into the 2-sphere as special cases. In particular, the results presented here recover some of the previously known results in the setting of the 1D-Schrödinger map equation.
One-way mode transmission in one-dimensional phononic crystal plates
Zhu, Xuefeng; Zou, Xinye; Liang, Bin; Cheng, Jianchun
2010-12-01
We investigate theoretically the band structures of one-dimensional phononic crystal (PC) plates with both antisymmetric and symmetric structures, and show how unidirectional transmission behavior can be obtained for either antisymmetric waves (A modes) or symmetric waves (S modes) by exploiting mode conversion and selection in the linear plate systems. The theoretical approach is illustrated for one PC plate example where unidirectional transmission behavior is obtained in certain frequency bands. Employing harmonic frequency analysis, we numerically demonstrate the one-way mode transmission for the PC plate with finite superlattice by calculating the steady-state displacement fields under A modes source (or S modes source) in forward and backward direction, respectively. The results show that the incident waves from A modes source (or S modes source) are transformed into S modes waves (or A modes waves) after passing through the superlattice in the forward direction and the Lamb wave rejections in the backward direction are striking with a power extinction ratio of more than 1000. The present structure can be easily extended to two-dimensional PC plate and efficiently encourage practical studies of experimental realization which is believed to have much significance for one-way Lamb wave mode transmission.
Unconventional Andreev reflection on the quasi-one-dimensional superconductor Nb2PdxSe5
Directory of Open Access Journals (Sweden)
Yeping Jiang
2016-04-01
Full Text Available We have carried out Andreev reflection measurements on point contact junctions between normal metal and single crystals of the quasi-one-dimensional (Q1D superconductor Nb2PdxSe5 (Tc ∼ 5.5 K. The contacts of the junctions were made on either self-cleaved surfaces or crystal edges so that the current flow directions in the two types of junctions are different, and the measurements provide a directional probe for the order parameter of the superconductor. Junctions made in both configurations show typical resistances of ∼20-30 Ohms, and a clear double-gap Andreev reflection feature was consistently observed at low temperatures. Quantitative analysis of the conductance spectrum based on a modified Blonder-Tinkham-Klapwijk (BTK model suggests that the amplitudes of two order parameters may have angular dependence in the a-c plane. Moreover, the gap to transition temperature ratio (Δ/TC for the larger gap is substantially higher than the BCS ratio expected for phonon-mediated s-wave superconductors. We argue that the anisotropic superconducting order parameter and the extremely large gap to transition temperature ratio may be associated with an unconventional pairing mechanism in the inorganic Q1D superconductor.
Areas and sizes of cascades in dissipative one-dimensional sandpile model
Liu, Jie; Hui, P. M.
2017-08-01
A prototypical self-organized sandpile mode is studied on a one-dimensional (1D) chain with periodic boundary conditions. A dissipation mechanism in which every grain being transferred between nodes has a probability ɛ to be taken out is needed, as the system has no boundary nodes for grains to fall off - a feature reminiscent of complex networks. Detailed numerical analysis revealed distributions of cascade areas D (a) and cascade sizes D (s) that are intrinsically different from other 1D sandpile models with an open end. Analyzing cascading processes on a chain, independent-site approximations to D (a) and D (s) are developed. The approximated distributions are given in terms of a single parameter ϕ0, which is the fraction of empty nodes when the system is stable. The approximations are shown to capture the key features of the distributions. The distribution of cascade sizes D (s) is shown to exhibit large fluctuations that cannot be suppressed by averaging over different realizations. Our approximation provides a physically transparent explanation of the intrinsic large fluctuations in terms of the number of ways that a cascade can proceed for achieving a certain size. To close the approximations, a semi-empirical formula for the parameter ϕ0 as a function of the dissipation probability ɛ is found. Our work thus reports non-trivial results on a seemingly simple model and sheds light on analyzing cascading processes in other complex networks with no boundary nodes.
Ultrafast optical spectroscopy of quasi one dimensional Ta{sub 2}NiSe{sub 5}
Energy Technology Data Exchange (ETDEWEB)
Mor, Selene; Herzog, Marc; Monney, Claude; Staehler, Julia; Wolf, Martin [Fritz-Haber-Institut der MPG, Dept. of Phys. Chem., Berlin (Germany)
2015-07-01
Ta2NiSe5 is a layered compound in which atomic chains are aligned in the layers, forming a quasi one dimensional crystal structure. At 328 K, the system shows a structural change, which is accompanied by an electronic phase transition from a semiconductor to an excitonic insulator, with an estimated energy gap of about few hundreds millielectronvolts. Our aim is to unveil the microscopic mechanisms underlying the phase transition in Ta{sub 2}NiSe{sub 5}. The system is excited with a femtosecond Ti:sapphire fundamental laser pulse and the mid-infrared (MIR) transient optical response is monitored by ultrafast optical spectroscopy. We observe a fast rise of transient reflectivity, which decays exponentially. This incoherent response is superimposed by a coherent phonon oscillation. A preliminary study with white light (WL) probe beam shows that low repetition rate is mandatory to study the response of the photoexcited system. The analysis unveils the presence of two phonons at 3 and 4 THz, that dominate at high (HT) and low (LT) temperature, respectively. We study the time evolution of the two phonons in the LT phase. We reveal a finite lifetime for the LT phase phonon, whose amplitude decays within few picoseconds, while the HT phase phonon amplitude remains almost constant. The picture is supported by temperature-dependent Raman spectroscopy.
One-dimensional pore pressure diffusion of different grain-fluid mixtures
von der Thannen, Magdalena; Kaitna, Roland
2015-04-01
During the release and the flow of fully saturated debris, non-hydrostatic fluid pressure can build up and probably dissipate during the event. This excess fluid pressure has a strong influence on the flow and deposition behaviour of debris flows. Therefore, we investigate the influence of mixture composition on the dissipation of non-hydrostatic fluid pressures. For this we use a cylindrical pipe of acrylic glass with installed pore water pressure sensors in different heights and measure the evolution of the pore water pressure over time. Several mixtures with variable content of fine sediment (silt and clay) and variable content of coarse sediment (with fixed relative fractions of grains between 2 and 32 mm) are tested. For the fines two types of clay (smectite and kaolinite) and loam (Stoober Lehm) are used. The analysis is based on the one-dimensional consolidation theory which uses a diffusion coefficient D to model the decay of excess fluid pressure over time. Starting from artificially induced super-hydrostatic fluid pressures, we find dissipation coefficients ranging from 10-5 m²/s for liquid mixtures to 10-8 m²/s for viscous mixtures. The results for kaolinite and smectite are quite similar. For our limited number of mixtures the effect of fines content is more pronounced than the effect of different amounts of coarse particles.
On the One-Dimensional Modeling of Vertical Upward Bubbly Flow
Directory of Open Access Journals (Sweden)
C. Peña-Monferrer
2018-01-01
Full Text Available The one-dimensional two-fluid model approach has been traditionally used in thermal-hydraulics codes for the analysis of transients and accidents in water–cooled nuclear power plants. This paper investigates the performance of RELAP5/MOD3 predicting vertical upward bubbly flow at low velocity conditions. For bubbly flow and vertical pipes, this code applies the drift-velocity approach, showing important discrepancies with the experiments compared. Then, we use a classical formulation of the drag coefficient approach to evaluate the performance of both approaches. This is based on the critical Weber criteria and includes several assumptions for the calculation of the interfacial area and bubble size that are evaluated in this work. A more accurate drag coefficient approach is proposed and implemented in RELAP5/MOD3. Instead of using the Weber criteria, the bubble size distribution is directly considered. This allows the calculation of the interfacial area directly from the definition of Sauter mean diameter of a distribution. The results show that only the proposed approach was able to predict all the flow characteristics, in particular the bubble size and interfacial area concentration. Finally, the computational results are analyzed and validated with cross-section area average measurements of void fraction, dispersed phase velocity, bubble size, and interfacial area concentration.
Inductive intrinsic localized modes in a one-dimensional nonlinear electric transmission line.
Sato, M; Mukaide, T; Nakaguchi, T; Sievers, A J
2016-07-01
The experimental properties of intrinsic localized modes (ILMs) have long been compared with theoretical dynamical lattice models that make use of nonlinear onsite and/or nearest-neighbor intersite potentials. Here it is shown for a one-dimensional lumped electrical transmission line that a nonlinear inductive component in an otherwise linear parallel capacitor lattice makes possible a new kind of ILM outside the plane wave spectrum. To simplify the analysis, the nonlinear inductive current equations are transformed to flux transmission line equations with analog onsite hard potential nonlinearities. Approximate analytic results compare favorably with those obtained from a driven damped lattice model and with eigenvalue simulations. For this mono-element lattice, ILMs above the top of the plane wave spectrum are the result. We find that the current ILM is spatially compressed relative to the corresponding flux ILM. Finally, this study makes the connection between the dynamics of mass and force constant defects in the harmonic lattice and ILMs in a strongly anharmonic lattice.
Doyon, Benjamin; Dubail, Jérôme; Konik, Robert; Yoshimura, Takato
2017-11-01
The theory of generalized hydrodynamics (GHD) was recently developed as a new tool for the study of inhomogeneous time evolution in many-body interacting systems with infinitely many conserved charges. In this Letter, we show that it supersedes the widely used conventional hydrodynamics (CHD) of one-dimensional Bose gases. We illustrate this by studying "nonlinear sound waves" emanating from initial density accumulations in the Lieb-Liniger model. We show that, at zero temperature and in the absence of shocks, GHD reduces to CHD, thus for the first time justifying its use from purely hydrodynamic principles. We show that sharp profiles, which appear in finite times in CHD, immediately dissolve into a higher hierarchy of reductions of GHD, with no sustained shock. CHD thereon fails to capture the correct hydrodynamics. We establish the correct hydrodynamic equations, which are finite-dimensional reductions of GHD characterized by multiple, disjoint Fermi seas. We further verify that at nonzero temperature, CHD fails at all nonzero times. Finally, we numerically confirm the emergence of hydrodynamics at zero temperature by comparing its predictions with a full quantum simulation performed using the NRG-TSA-abacus algorithm. The analysis is performed in the full interaction range, and is not restricted to either weak- or strong-repulsion regimes.
DC field response of one-dimensional flames using an ionized layer model
Xiong, Yuan
2015-11-18
We develop a simplified model to better explain electric current response when direct current (DC) is applied to a flame. In particular, different current responses have been observed by changing the polarity of the DC in a sub-saturated current regime that results from the presence of ions and electrons in the flame zone. A flame zone was modeled as a thin, ionized layer located in one-dimensional DC electric fields. We derived simplified model-governing equations from species equations by implementing mobility differences dependent on the type of charged particle, particularly between ions and electrons; we performed experiments to substantiate the model. Results showed that the sub-saturated current and local field intensity were significantly influenced by the polarity of the DC because of the combined effect of unequal mobility of charged particles and the position of the ionized layer in the gap relative to two electrodes. When an energized electrode is close to the ionized layer, applying a negative DC causes a more rapid increase in current than by applying a positive DC to the same electrode. Results from our experimental measurement of current using counterflow diffusion flames agreed qualitatively well with the model predictions. A sensitivity analysis using dimensional and non-dimensional parameters also supported the importance of the mobility difference and the relative location of the ionized layer on the electric current response.
Uncertainty estimation in one-dimensional heat transport model for heterogeneous porous medium.
Chang, Ching-Min; Yeh, Hund-Der
2014-01-01
In many practical applications, the rates for ground water recharge and discharge are determined based on the analytical solution developed by Bredehoeft and Papadopulos (1965) to the one-dimensional steady-state heat transport equation. Groundwater flow processes are affected by the heterogeneity of subsurface systems; yet, the details of which cannot be anticipated precisely. There exists a great deal of uncertainty (variability) associated with the application of Bredehoeft and Papadopulos' solution (1965) to the field-scale heat transport problems. However, the quantification of uncertainty involved in such application has so far not been addressed, which is the objective of this wok. In addition, the influence of the statistical properties of log hydraulic conductivity field on the variability in temperature field in a heterogeneous aquifer is also investigated. The results of the analysis demonstrate that the variability (or uncertainty) in the temperature field increases with the correlation scale of the log hydraulic conductivity covariance function and the variability of temperature field also depends positively on the position. © 2013, National Ground Water Association.
Low-lying Photoexcited States of a One-Dimensional Ionic Extended Hubbard Model
Yokoi, Kota; Maeshima, Nobuya; Hino, Ken-ichi
2017-10-01
We investigate the properties of low-lying photoexcited states of a one-dimensional (1D) ionic extended Hubbard model at half-filling. Numerical analysis by using the full and Lanczos diagonalization methods shows that, in the ionic phase, there exist low-lying photoexcited states below the charge transfer gap. As a result of comparison with numerical data for the 1D antiferromagnetic (AF) Heisenberg model, it was found that, for a small alternating potential Δ, these low-lying photoexcited states are spin excitations, which is consistent with a previous analytical study [Katsura et al., https://doi.org/10.1103/PhysRevLett.103.177402" xlink:type="simple">Phys. Rev. Lett. 103, 177402 (2009)]. As Δ increases, the spectral intensity of the 1D ionic extended Hubbard model rapidly deviates from that of the 1D AF Heisenberg model and it is clarified that this deviation is due to the neutral-ionic domain wall, an elementary excitation near the neutral-ionic transition point.
Calculus of variations an introduction to the one-dimensional theory with examples and exercises
Kielhöfer, Hansjörg
2018-01-01
This clear and concise textbook provides a rigorous introduction to the calculus of variations, depending on functions of one variable and their first derivatives. It is based on a translation of a German edition of the book Variationsrechnung (Vieweg+Teubner Verlag, 2010), translated and updated by the author himself. Topics include: the Euler-Lagrange equation for one-dimensional variational problems, with and without constraints, as well as an introduction to the direct methods. The book targets students who have a solid background in calculus and linear algebra, not necessarily in functional analysis. Some advanced mathematical tools, possibly not familiar to the reader, are given along with proofs in the appendix. Numerous figures, advanced problems and proofs, examples, and exercises with solutions accompany the book, making it suitable for self-study. The book will be particularly useful for beginning graduate students from the physical, engineering, and mathematical sciences with a rigorous th...
Directory of Open Access Journals (Sweden)
Yan-He Li
Full Text Available Transcriptome sequencing could facilitate discovery of sex-biased genes, biological pathways and molecular markers, which could help clarify the molecular mechanism of sex determination and sexual dimorphism, and assist with selective breeding in aquaculture. Yellow perch has unique gonad system and sexual dimorphism and is an alternative model to study mechanism of sex determination, sexual dimorphism and sexual selection. In this study, we performed the de novo assembly of yellow perch gonads and muscle transcriptomes by high throughput Illumina sequencing. A total of 212,180 contigs were obtained, ranging from 127 to 64,876 bp, and N50 of 1,066 bp. The assembly RNA-Seq contigs (≥200bp were then used for subsequent analyses, including annotation, pathway analysis, and microsatellites discovery. No female- and pseudo-male-biased genes were involved in any pathways while male-biased genes were involved in 29 pathways, and neuroactive ligand receptor interaction and enzyme of trypsin (enzyme code, EC: 3.4.21.4 was highly involved. Pyruvate kinase (enzyme code, EC: 2.7.1.40, which plays important roles in cell proliferation, was highly expressed in muscles. In addition, a total of 183,939 SNPs, 11,286 InDels and 41,479 microsatellites were identified. This study is the first report on transcriptome information in Percids, and provides rich resources for conducting further studies on understanding the molecular basis of sex determinations, sexual dimorphism, and sexual selection in fish, and for population studies and marker-assisted selection in Percids.
Towards automatic metabolomic profiling of high-resolution one-dimensional proton NMR spectra
Energy Technology Data Exchange (ETDEWEB)
Mercier, Pascal; Lewis, Michael J.; Chang, David, E-mail: dchang@chenomx.com [Chenomx Inc (Canada); Baker, David [Pfizer Inc (United States); Wishart, David S. [University of Alberta, Department of Computing Science and Biological Sciences (Canada)
2011-04-15
Nuclear magnetic resonance (NMR) and Mass Spectroscopy (MS) are the two most common spectroscopic analytical techniques employed in metabolomics. The large spectral datasets generated by NMR and MS are often analyzed using data reduction techniques like Principal Component Analysis (PCA). Although rapid, these methods are susceptible to solvent and matrix effects, high rates of false positives, lack of reproducibility and limited data transferability from one platform to the next. Given these limitations, a growing trend in both NMR and MS-based metabolomics is towards targeted profiling or 'quantitative' metabolomics, wherein compounds are identified and quantified via spectral fitting prior to any statistical analysis. Despite the obvious advantages of this method, targeted profiling is hindered by the time required to perform manual or computer-assisted spectral fitting. In an effort to increase data analysis throughput for NMR-based metabolomics, we have developed an automatic method for identifying and quantifying metabolites in one-dimensional (1D) proton NMR spectra. This new algorithm is capable of using carefully constructed reference spectra and optimizing thousands of variables to reconstruct experimental NMR spectra of biofluids using rules and concepts derived from physical chemistry and NMR theory. The automated profiling program has been tested against spectra of synthetic mixtures as well as biological spectra of urine, serum and cerebral spinal fluid (CSF). Our results indicate that the algorithm can correctly identify compounds with high fidelity in each biofluid sample (except for urine). Furthermore, the metabolite concentrations exhibit a very high correlation with both simulated and manually-detected values.
One-dimensional electromagnetic band gap structures formed by discharge plasmas in a waveguide
Energy Technology Data Exchange (ETDEWEB)
Arkhipenko, V. I.; Simonchik, L. V., E-mail: l.simonchik@dragon.bas-net.by; Usachonak, M. S. [B.I. Stepanov Institute of Physics of the NAS of Belarus, Ave. Nezavisimostsi 68, 220072 Minsk (Belarus); Callegari, Th.; Sokoloff, J. [Université de Toulouse, UPS, INPT, LAPLACE, Laboratoire Plasma et Conversion d' Energie, 118 route de Narbonne, F-31062 Toulouse cedex 9 (France)
2014-09-28
We demonstrate the ability to develop one-dimensional electromagnetic band gap structure in X-band waveguide solely by using the positive columns of glow discharges in neon at the middle pressure. Plasma inhomogeneities are distributed uniformly along a typical X-band waveguide with cross section of 23×10 mm². It is shown that electron densities larger than 10¹⁴ cm ⁻³ are needed in order to create an effective one-dimensional electromagnetic band gap structure. Some applications for using the one-dimensional electromagnetic band gap structure in waveguide as a control of microwave (broadband filter and device for variation of pulse duration) are demonstrated.
Hybrid Semiclassical Theory of Quantum Quenches in One-Dimensional Systems.
Moca, Cătălin Paşcu; Kormos, Márton; Zaránd, Gergely
2017-09-08
We develop a hybrid semiclassical method to study the time evolution of one-dimensional quantum systems in and out of equilibrium. Our method handles internal degrees of freedom completely quantum mechanically by a modified time-evolving block decimation method while treating orbital quasiparticle motion classically. We can follow dynamics up to time scales well beyond the reach of standard numerical methods to observe the crossover between preequilibrated and locally phase equilibrated states. As an application, we investigate the quench dynamics and phase fluctuations of a pair of tunnel-coupled one-dimensional Bose condensates. We demonstrate the emergence of soliton-collision-induced phase propagation, soliton-entropy production, and multistep thermalization. Our method can be applied to a wide range of gapped one-dimensional systems.
Crystal-Phase Quantum Wires: One-Dimensional Heterostructures with Atomically Flat Interfaces.
Corfdir, Pierre; Li, Hong; Marquardt, Oliver; Gao, Guanhui; Molas, Maciej R; Zettler, Johannes K; van Treeck, David; Flissikowski, Timur; Potemski, Marek; Draxl, Claudia; Trampert, Achim; Fernández-Garrido, Sergio; Grahn, Holger T; Brandt, Oliver
2018-01-10
In semiconductor quantum-wire heterostructures, interface roughness leads to exciton localization and to a radiative decay rate much smaller than that expected for structures with flat interfaces. Here, we uncover the electronic and optical properties of the one-dimensional extended defects that form at the intersection between stacking faults and inversion domain boundaries in GaN nanowires. We show that they act as crystal-phase quantum wires, a novel one-dimensional quantum system with atomically flat interfaces. These quantum wires efficiently capture excitons whose radiative decay gives rise to an optical doublet at 3.36 eV at 4.2 K. The binding energy of excitons confined in crystal-phase quantum wires is measured to be more than twice larger than that of the bulk. As a result of their unprecedented interface quality, these crystal-phase quantum wires constitute a model system for the study of one-dimensional excitons.
One-dimensional transport equation models for sound energy propagation in long spaces: theory.
Jing, Yun; Larsen, Edward W; Xiang, Ning
2010-04-01
In this paper, a three-dimensional transport equation model is developed to describe the sound energy propagation in a long space. Then this model is reduced to a one-dimensional model by approximating the solution using the method of weighted residuals. The one-dimensional transport equation model directly describes the sound energy propagation in the "long" dimension and deals with the sound energy in the "short" dimensions by prescribed functions. Also, the one-dimensional model consists of a coupled set of N transport equations. Only N=1 and N=2 are discussed in this paper. For larger N, although the accuracy could be improved, the calculation time is expected to significantly increase, which diminishes the advantage of the model in terms of its computational efficiency.
An interpolatory ansatz captures the physics of one-dimensional confined Fermi systems
DEFF Research Database (Denmark)
Andersen, Molte Emil Strange; Salami Dehkharghani, Amin; Volosniev, A. G.
2016-01-01
Interacting one-dimensional quantum systems play a pivotal role in physics. Exact solutions can be obtained for the homogeneous case using the Bethe ansatz and bosonisation techniques. However, these approaches are not applicable when external confinement is present. Recent theoretical advances...... beyond the Bethe ansatz and bosonisation allow us to predict the behaviour of one-dimensional confined systems with strong short-range interactions, and new experiments with cold atomic Fermi gases have already confirmed these theories. Here we demonstrate that a simple linear combination of the strongly...... interacting solution with the well-known solution in the limit of vanishing interactions provides a simple and accurate description of the system for all values of the interaction strength. This indicates that one can indeed capture the physics of confined one-dimensional systems by knowledge of the limits...
One-dimensional description of multidimensional electron transfer reactions in condensed phase.
Dhole, Kajal; Samanta, Alok; Ghosh, Swapan K
2008-06-05
We derive a one-dimensional energy diffusion equation for describing the dynamics of multidimensional electron transfer reactions in condensed phase, which is conceptually simpler and computationally more economic than the conventional approaches. We also obtain an analytical expression for the rate of electron transfer reactions for a general one-dimensional effective potential as well as an energy dependent diffusitivity. As an illustrative example, we consider application to electron transfer in a contact ion pair system modeled through harmonic potentials consisting of two slow classical modes and a high frequency vibrational mode for which the numerical results calculated using the proposed one-dimensional approach are shown to be in good agreement with experimental results. The energy diffusion equation and the rate expression for electron transfer obtained from the present theory, therefore, open up the possibility of describing the dynamics of electron transfer in complex systems, through a simpler approach.
Directory of Open Access Journals (Sweden)
Xiwei Zhang
2017-10-01
Full Text Available Wide band gap II-VI semiconductor nanostructures have been extensively studied according to their great potentials for optoelectronic applications, while heterojunctions are fundamental elements for modern electronic and optoelectronic devices. Subsequently, a great deal of achievements in construction and optoelectronic applications of heterojunctions based on II-VI compound semiconductor one-dimensional nanostructures have been obtained in the past decade. Herein, we present a review of a series of progress in this field. First, construction strategies towards different types of heterojunctions are reviewed, including core-shell heterojunctions, one-dimensional axial heterojunctions, crossed nanowires heterojunctions, and one-dimensional nanostructure/thin film or Si substrate heterojunctions. Secondly, optoelectronic applications of these constructed heterojunctions, such as photodetectors, solar cells, light emitting diodes, junction field effect transistors, etc., are discussed briefly. This review shows that heterojunctions based on II-VI compound semiconductor 1-D nanostructures have great potential for future optoelectronic applications.
Quantum quenches to the attractive one-dimensional Bose gas: exact results
Directory of Open Access Journals (Sweden)
Lorenzo Piroli, Pasquale Calabrese, Fabian H. L. Essler
2016-09-01
Full Text Available We study quantum quenches to the one-dimensional Bose gas with attractive interactions in the case when the initial state is an ideal one-dimensional Bose condensate. We focus on properties of the stationary state reached at late times after the quench. This displays a finite density of multi-particle bound states, whose rapidity distribution is determined exactly by means of the quench action method. We discuss the relevance of the multi-particle bound states for the physical properties of the system, computing in particular the stationary value of the local pair correlation function $g_2$.
Metal-insulator transition in one-dimensional lattices with chaotic energy sequences
Energy Technology Data Exchange (ETDEWEB)
Pinto, R.A. [Laboratorio de Fisica Estadistica, Centro de Fisica, Instituto Venezolano de Investigaciones Cientificas, Apartado 21827, Caracas 1020-A (Venezuela)]. E-mail: ripinto@ivic.ve; Rodriguez, M. [Laboratorio de Fisica Estadistica, Centro de Fisica, Instituto Venezolano de Investigaciones Cientificas, Apartado 21827, Caracas 1020-A (Venezuela); Gonzalez, J.A. [Laboratorio de Fisica Computacional, Centro de Fisica, Instituto Venezolano de Investigaciones Cientificas, Apartado 21827, Caracas 1020-A (Venezuela); Medina, E. [Laboratorio de Fisica Estadistica, Centro de Fisica, Instituto Venezolano de Investigaciones Cientificas, Apartado 21827, Caracas 1020-A (Venezuela)
2005-06-20
We study electronic transport through a one-dimensional array of sites by using a tight binding Hamiltonian, whose site-energies are drawn from a chaotic sequence. The correlation degree between these energies is controlled by a parameter regulating the dynamic Lyapunov exponent measuring the degree of chaos. We observe the effect of chaotic sequences on the localization length, conductance, conductance distribution and wave function, finding evidence of a metal-insulator transition (MIT) at a critical degree of chaos. The one-dimensional metallic phase is characterized by a Gaussian conductance distribution and exhibits a peculiar non-selfaveraging.
One dimensional Si/Sn - based nanowires and nanotubes for lithium-ion energy storage materials
Choi, Nam-Soon
2011-01-01
There has been tremendous interest in using nanomaterials for advanced Li-ion battery electrodes, particularly to increase the energy density by using high specific capacity materials. Recently, it was demonstrated that one dimensional (1D) Si/Sn nanowires (NWs) and nanotubes (NTs) have great potential to achieve high energy density as well as long cycle life for the next generation of advanced energy storage applications. In this feature article, we review recent progress on Si-based NWs and NTs as high capacity anode materials. Fundamental understanding and future challenges on one dimensional nanostructured anode are also discussed. © 2010 The Royal Society of Chemistry.
Analytic calculation of energy transfer and heat flux in a one-dimensional system
Balakrishnan, V.; van den Broeck, C.
2005-10-01
In the context of the problem of heat conduction in one-dimensional systems, we present an analytical calculation of the instantaneous energy transfer across a tagged particle in a one-dimensional gas of equal-mass, hard-point particles. From this, we obtain a formula for the steady-state energy flux, and identify and separate the mechanical work and heat conduction contributions to it. The nature of the Fourier law for the model, and the nonlinear dependence of the rate of mechanical work on the stationary drift velocity of the tagged particle, are analyzed and elucidated.
Theoretical Studies on Phase Transitions in Quasi-One-Dimensional Molecular Conductors
Directory of Open Access Journals (Sweden)
Yuichi Otsuka
2012-07-01
Full Text Available A review is given for recent theoretical studies on phase transitions in quasi-one-dimensional molecular conductors with a quarter-filled band. By lowering temperature, charge transfer salts exhibit a variety of transitions accompanying symmetry breaking, such as charge ordering, lattice dimerization, antiferromagnetic transition, spin-Peierls distortion, and so on. Analyses on microscopic quasi-one-dimensional models provide their systematic understandings, by the complementary use of different analytical and numerical techniques; they can reproduce finite-temperature phase transitions, whose results can be directly compared with experiments and give feedbacks to material design.
Quasi-exact solvability of the one-dimensional Holstein model
Energy Technology Data Exchange (ETDEWEB)
Pan Feng [Department of Physics, Liaoning Normal University, Dalian 116029 (China); Dai Lianrong [Department of Physics, Liaoning Normal University, Dalian 116029 (China); Draayer, J P [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803-4001 (United States)
2006-03-31
The one-dimensional Holstein model of spinless fermions interacting with dispersionless phonons is solved by using a Bethe ansatz in analogue to that for the one-dimensional spinless Fermi-Hubbard model. Excitation energies and the corresponding wavefunctions of the model are determined by a set of partial differential equations. It is shown that the model is, at least, quasi-exactly solvable for the two-site case, when the phonon frequency, the electron-phonon coupling strength and the hopping integral satisfy certain relations. As examples, some quasi-exact solutions of the model for the two-site case are derived. (letter to the editor)
Controlling ultrashort pulses shape using one-dimensional graded index photonic crystals
Bananej, A.; Khalkhali, T. Fathollahi
2017-08-01
In this study, we analyze the characteristics of a one dimensional coupled cavity-waveguide composed of SiO2 / TiO2 layers in which three defects are located symmetrically in structure, using finite-time domain-method and transfer matrix method. Then we introduced a new structure based on mentioned one-dimensional structure in which the higher refractive index material is maintained constant, while lower refractive index slightly increases with a constant step value from the beginning to the end of the structure. Simulation results reveal that the graded structure represents unique features in comparison with the conventional structure.
Chemical potential for the Bose gases in a one-dimensional harmonic trap
Energy Technology Data Exchange (ETDEWEB)
Liu, T G; Niu, M Y [Key Laboratory for Micro-Nano Optoelectronic Devices of Ministry of Education and State Key Laboratory for Chemo/Biosensing and Chemometrics, Hunan University, Changsha, 410082 (China); Liu, Q H, E-mail: quanhuiliu@gmail.co [School for Theoretical Physics and Department of Applied Physics, Hunan University, Changsha, 410082 (China)
2010-05-15
A closed expression for the chemical potential of Bose gases in an external one-dimensional harmonic trap, reported recently in this journal (Mungan 2009 Chemical potential of one-dimensional simple harmonic oscillators Eur. J. Phys. 30 1131-6), is approximate and not applicable for temperatures lower than a characteristic value below which the ground state becomes occupied by a macroscopic number of particles. In this letter, the correct behaviour of the chemical potential at low temperature is addressed. (letters and comments)
Directory of Open Access Journals (Sweden)
Nicolai Lang, Hans Peter Büchler
2018-01-01
Full Text Available Active quantum error correction on topological codes is one of the most promising routes to long-term qubit storage. In view of future applications, the scalability of the used decoding algorithms in physical implementations is crucial. In this work, we focus on the one-dimensional Majorana chain and construct a strictly local decoder based on a self-dual cellular automaton. We study numerically and analytically its performance and exploit these results to contrive a scalable decoder with exponentially growing decoherence times in the presence of noise. Our results pave the way for scalable and modular designs of actively corrected one-dimensional topological quantum memories.
Design of the Decomposed State Model of an One-Dimensional Piecewise-Linear System
Directory of Open Access Journals (Sweden)
Z. Kolka
1994-03-01
Full Text Available Present paper deals with the problem of automatic design of the implicit state model (in its decomposed parametric form of any one-dimensional piecewise-linear (PWL system. This model consists of the internal and the external parts which provides the possibility to find the model parameters, i.e. to solve separately the two main problems of an one-dimensional PWL model design: (i existence of the individual breakpoints of the resultant PWL characteristic (determined by the internal block; (ii setting of the breakpoint co-ordinates (determined by the external block.
Recent improvements to and validation of the one dimensional NASA wave rotor model
Paxson, Daniel E.; Wilson, Jack
1995-01-01
A numerical model has been developed at the NASA Lewis Research Center which can predict both the unsteady flow quantities within a wave rotor passage and the steady averaged flows in the ports. The model is based on the assumptions of one-dimensional, unsteady, perfect gas flow. The model assesses not only the dominant wave behavior, but the loss effects of finite passage opening time, leakage from the passage ends, viscosity, and heat transfer to and from the passages. The model operates in the rotor reference frame; however, until recently no account was made for the often significant effect of the rotor circumferential velocity component. The present model accounts for this by modifying the passage boundary conditions, allowing the internal computational scheme to remain the rotor reference frame, while quantities such as inlet duct stagnation properties may be specified in the fixed or absolute reference frame. Accurate modeling of this effect is critical to successful wave rotor analysis and design, particularly in off-design predictions where the flows in the inlet ducts are mismatched with the rotor passages and significant turning may take place (i.e., work is done on the gas). The relative simplicity of the model makes it useful for design and optimization, as well as analysis, of wave rotor cycles for many applications. This report, building on several earlier papers, describes the most recent modifications to the model. These include accounting for the relative/absolute transition at the passage boundaries and refinements to the viscous source term correlation which resulted from this accounting. Comparison of model predictions with measured data is then presented and discussed.
Rubin, Nicholas C
2014-01-01
Minimizing the energy of an $N$-electron system as a functional of a two-electron reduced density matrix (2-RDM), constrained by necessary $N$-representability conditions (conditions for the 2-RDM to represent an ensemble $N$-electron quantum system), yields a rigorous lower bound to the ground-state energy in contrast to variational wavefunction methods. We characterize the performance of two sets of approximate constraints, (2,2)-positivity (DQG) and approximate (2,3)-positivity (DQGT) conditions, at capturing correlation in one-dimensional and quasi-one-dimensional (ladder) Hubbard models. We find that, while both the DQG and DQGT conditions capture both the weak and strong correlation limits, the more stringent DQGT conditions improve the ground-state energies, the natural occupation numbers, the pair correlation function, the effective hopping, and the connected (cumulant) part of the 2-RDM. We observe that the DQGT conditions are effective at capturing strong electron correlation effects in both one- an...
Grillo, Vince
2017-01-01
The objective of this presentation is to give a brief overview of the theory behind the (DBA) method, an overview of the derivation and a practical application of the theory using the Python computer language. The Theory and Derivation will use both Acceleration and Pseudo Velocity methods to derive a series of equations for processing by Python. We will take the results and compare both Acceleration and Pseudo Velocity methods and discuss implementation of the Python functions. Also, we will discuss the efficiency of the methods and the amount of computer time required for the solution. In conclusion, (DBA) offers a powerful method to evaluate the amount of energy imparted into a system in the form of both Amplitude and Duration during qualification testing and flight environments. Many forms of steady state and transient vibratory motion can be characterized using this technique. (DBA) provides a more robust alternative to traditional methods such Power Spectral Density (PSD) using a maximax approach.
Directory of Open Access Journals (Sweden)
S. Das
2015-09-01
Full Text Available This paper is concerned with the entropy generation in a magnetohydrodynamic (MHD pseudo-plastic nanofluid flow through a porous channel with convective heating. Three different types of nanoparticles, namely copper, aluminum oxide and titanium dioxide are considered with pseudo-plastic carboxymethyl cellulose (CMC–water used as base fluids. The governing equations are solved numerically by shooting technique coupled with Runge–Kutta scheme. The effects of the pertinent parameters on the fluid velocity, temperature, entropy generation, Bejan number as well as the shear stresses at the channel walls are presented graphically and analyzed in detail. It is possible to determine optimum values of magnetic parameter, power-law index, Eckert number and Boit number which lead to a minimum entropy generation rate.
Grillo, Vince
2016-01-01
The objective of this presentation is to give a brief overview of the theory behind the (DBA) method, an overview of the derivation and a practical application of the theory using the Python computer language. The Theory and Derivation will use both Acceleration and Pseudo Velocity methods to derive a series of equations for processing by Python. We will take the results and compare both Acceleration and Pseudo Velocity methods and discuss implementation of the Python functions. Also, we will discuss the efficiency of the methods and the amount of computer time required for the solution. In conclusion, (DBA) offers a powerful method to evaluate the amount of energy imparted into a system in the form of both Amplitude and Duration during qualification testing and flight environments. Many forms of steady state and transient vibratory motion can be characterized using this technique. (DBA) provides a more robust alternative to traditional methods such Power Spectral Density (PSD) using a Maximax approach.
Skrypnyk, Y V
1998-01-01
The rearrangement of the acoustic phonon spectrum under the increase of isotope impurity concentration is studied in a one-dimensional system. The analysis is based on the method of the expansion of the single-particle Green's function in terms clusters of the indirectly interacting impurity centers. It is demonstrated that the criterion for the validity of the coherent potential approximation(CPA) coincides exactly with the conventional Ioffe-Regel-Mott criterion. Approximate solutions for the dispersion relation and density of states are obtained for concentrations larger and smaller than the critical concentration of the spectrum rearrangement.
Directory of Open Access Journals (Sweden)
Eugenia A. Sar
2006-12-01
Full Text Available En el marco de un proyecto de monitoreo de especies de diatomeas nocivas llevado a cabo en el área norte del Golfo San Matías (Provincia de Río Negro, Argentina hemos encontrado a Pseudo-nitzschia pungens (Grunow ex. P.T. Cleve Hasle var. pungens y establecido cultivos monoclonales de esta variedad. Las cepas aisladas a partir de muestras tomadas con red, provenientes de Las Grutas y Piedras Coloradas (Golfo San Matías, fueron cultivadas en medio F/2 con adición de silicatos, y mantenidas a 20 ºC con luz continua, blanca, fría. Los cultivos fueron analizados mediante Cromatografía Líquida de Alta Resolución (HPLC para determinar si la variedad aislada era productora de ácido domoico (DA en el área bajo estudio. Material procedente de campo y de cultivo fue estudiado con microscopios óptico y electrónico de barrido. Una comparación con los taxa más allegados, P . pungens var. cingulata Villac y P . multiseries (Hasle Hasle, y datos sobre la morfología fina del material procedente de los cultivos, son presentados y discutidos. A pesar de que P . pungens var. pungens ha sido reportada como productora de ácido domoico, los resultados del análisis para detección de las toxinas fueron negativos para las cultivos chequeados.In the framework of a project of monitoring of harmful diatom species carried out in the Northern area of the Golfo San Matías (Provincia de Río Negro, Argentina we found and established cultures of Pseudo-nitzschia pungens (Grunow ex. P.T. Cleve Hasle var. pungens . The strains isolated from net phytoplankton samples obtained in Las Grutas and Piedras Coloradas, (Golfo San Matías were cultured in F/2 medium, with silica added, and maintained at 20 ºC, under continuous light supplied by cool-white fluorescent tubes. Cultures were essayed for domoic acid (DA by High Performance Liquid Chromatography (HPLC. Materials from field and cultures were studied with light and scanning electron microscopy. Comparison
Koksal, Aycan; Wohlgenant, Michael
2013-01-01
In this paper, we generalize the rational addiction model to include three addictive goods: cigarettes, alcohol and coffee. We use a pseudo-panel data approach which has many advantages compared to aggregate and panel data. While cigarette and coffee demands fit well with the rational addiction model, alcohol demand does not. This result might be due to possible inventory effects. Our results suggest that although cigarettes and alcohol reinforce each other in consumption, consumers substitut...
A one-dimensional heat transfer model for parallel-plate thermoacoustic heat exchangers
de Jong, Anne; Wijnant, Ysbrand H.; de Boer, Andries
2014-01-01
A one-dimensional (1D) laminar oscillating flow heat transfer model is derived and applied to parallel-plate thermoacoustic heat exchangers. The model can be used to estimate the heat transfer from the solid wall to the acoustic medium, which is required for the heat input/output of thermoacoustic
One-dimensional model for heat transfer to a supercritical water flow in a tube
Sallevelt, J.L.H.P.; Withag, J.A.M.; Bramer, Eduard A.; Brilman, Derk Willem Frederik; Brem, Gerrit
2012-01-01
Heat transfer in water at supercritical pressures has been investigated numerically using a one-dimensional modeling approach. A 1D plug flow model has been developed in order to make fast predictions of the bulk-fluid temperature in a tubular flow. The chosen geometry is a vertical tube with an
N-point free energy distribution function in one dimensional random directed polymers
Directory of Open Access Journals (Sweden)
V. Dotsenko
2014-09-01
Full Text Available Explicit expression for the N-point free energy distribution function in one dimensional directed polymers in a random potential is derived in terms of the Bethe ansatz replica technique. The obtained result is equivalent to the one derived earlier by Prolhac and Spohn [J. Stat. Mech., 2011, P03020].
Studies of Phase Turbulence in the One Dimensional Complex Ginzburg-Landau Equation
Torcini, A; Grassberger, Peter; Torcini, Alessandro; Frauenkron, Helge; Grassberger, Peter
1997-01-01
The phase-turbulent (PT) regime for the one dimensional complex Ginzburg-Landau equation (CGLE) is carefully studied, in the limit of large systems and long integration times, using an efficient new integration scheme. Particular attention is paid to solutions with a non-zero phase gradient. For fixed control parameters, solutions with conserved average phase gradient $\
Effects of interaction imbalance in a strongly repulsive one-dimensional Bose gas
DEFF Research Database (Denmark)
Barfknecht, Rafael Emilio; Zinner, Nikolaj Thomas; Foerster, Angela
2018-01-01
We calculate the spatial distributions and the dynamics of a few-body two-component strongly interacting Bose gas confined to an effectively one-dimensional trapping potential. We describe the densities for each component in the trap for different interaction and population imbalances. We calcula...
Chuang, Chern; Knoester, Jasper; Cao, Jianshu
2014-01-01
We theoretically study the distance, chain length, and temperature dependence of the electronic couplings as well as the excitonic energy transfer rates between one-dimensional (1D) chromophore aggregates. In addition to the well-known geometry dependent factor that leads to the deviation from
Strongly interacting bosons in a one-dimensional optical lattice at incommensurate densities
Lazarides, A.|info:eu-repo/dai/nl/315556668; Tieleman, O.|info:eu-repo/dai/nl/341386456; de Morais Smith, C.|info:eu-repo/dai/nl/304836346
2011-01-01
We investigate quantum phase transitions occurring in a system of strongly interacting ultracold bosons in a one-dimensional optical lattice. After discussing the commensurate-incommensurate transition, we focus on the phases appearing at an incommensurate filling. We find a rich phase diagram, with
The Laplace transform solution of a one dimensional groundwater recharge by spreading
Directory of Open Access Journals (Sweden)
A. P. VERMA
1969-06-01
Full Text Available An analytical expression for the moisture content distribution,
in a problem of one dimensional vertical groundwater recharge, has
been obtained by using the Laplace transform method. The average diffusivity coefficient over the whole range of moisture content is regarded as constant, and a linear variation of permeability with moisture content is assumed.
Global solutions with infinite energy for the one-dimensional Zakharov system
Directory of Open Access Journals (Sweden)
Hartmut Pecher
2005-04-01
Full Text Available The one-dimensional Zakharov system is shown to have a unique global solution for data without finite energy. The proof uses the ``I-method'' introduced by Colliander, Keel, Staffilani, Takaoka, and Tao in connection with a refined bilinear Strichartz estimate.
ONE-DIMENSIONAL HYDRODYNAMIC/SEDIMENT TRANSPORT MODEL FOR STREAM NETWORKS: TECHNICAL REPORT
This technical report describes a new sediment transport model and the supporting post-processor, and sampling procedures for sediments in streams. Specifically, the following items are described herein: EFDC1D - This is a new one-dimensional hydrodynamic and sediment tr...
On the spin-liquid phase of one-dimensional spin-1 bosons
Essler, F.H.L.; Shlyapnikov, G.V.; Tsvelik, A.M.
2009-01-01
We consider a model of one-dimensional spin-1 bosons with repulsive density-density interactions and antiferromagnetic exchange. We show that the low energy effective field theory is given by a spin-charge separated theory of a Tomonaga-Luttinger Hamiltonian and the O(3) non-linear sigma model
Well-posedness for one-dimensional anisotropic Cahn-Hilliard and Allen-Cahn systems
Directory of Open Access Journals (Sweden)
Ahmad Makki
2015-01-01
Full Text Available Our aim is to prove the existence and uniqueness of solutions for one-dimensional Cahn-Hilliard and Allen-Cahn type equations based on a modification of the Ginzburg-Landau free energy proposed in [8]. In particular, the free energy contains an additional term called Willmore regularization and takes into account strong anisotropy effects.
Hydrodynamic limits for one-dimensional particle systems with moving boundaries
Chayes, L.; G. Swindle
1996-01-01
We analyze a new class of one-dimensional interacting particle systems featuring random boundaries with a random motion that is coupled to the local particle density. We show that the hydrodynamic limiting behavior in these systems corresponds to the solution of an appropriate. Stefan (free-boundary) equation and describe some applications of these results.
Simple One-Dimensional Quantum-Mechanical Model for a Particle Attached to a Surface
Fernandez, Francisco M.
2010-01-01
We present a simple one-dimensional quantum-mechanical model for a particle attached to a surface. It leads to the Schrodinger equation for a harmonic oscillator bounded on one side that we solve in terms of Weber functions and discuss the behaviour of the eigenvalues and eigenfunctions. We derive the virial theorem and other exact relationships…
Dynamic Monte Carlo simulation of the one-dimensional Potts model
Energy Technology Data Exchange (ETDEWEB)
Karma, A.S.
1982-12-01
Monte Carlo results are presented for a variety of one-dimensional q-state Potts models. Our calculation confirms the expected universal value z = 2 for the dynamic scaling exponent. Our results also indicate that an increase in q, at fixed correlation length, drives the dynamics into the scaling regime.
Spin and energy correlations in the one dimensional spin 1/2 Heisenberg model
Naef, F.; Zotos, X.
1997-01-01
In this paper, we study the spin and energy dynamic correlations of the one dimensional spin 1/2 Heisenberg model, using mostly exact diagonalization numerical techniques. In particular, observing that the uniform spin and energy currents decay to finite values at long times, we argue for the absence of spin and energy diffusion in the easy plane anisotropic Heisenberg model.
Explicit solutions of one-dimensional, first-order, stationary mean-field games with congestion
Gomes, Diogo A.
2017-01-05
Here, we consider one-dimensional first-order stationary mean-field games with congestion. These games arise when crowds face difficulty moving in high-density regions. We look at both monotone decreasing and increasing interactions and construct explicit solutions using the current formulation. We observe new phenomena such as discontinuities, unhappiness traps and the non-existence of solutions.
A one-dimensional analytical model for airborne contaminant transport in airliner cabins.
Mazumdar, S; Chen, Q
2009-02-01
Quick information on airborne infectious disease transmission in airliner cabins is essential to reduce the risk of infection of passengers and crew members. This investigation proposed a one-dimensional analytical model that can predict the longitudinal transmission of airborne contaminants or disease viruses inside an airliner cabin. The model considered both diffusive and convective transport of contaminants in the longitudinal direction of the cabin but assumed complete mixing of contaminants in the cabin cross-section. The effect of recirculation of the cabin air and efficiency of the high-efficiency particulate air (HEPA) filters is also considered in the model. The analytical solution for the one-dimensional contaminant transport model is obtained by using the principle of superposition and the method of separation of variables. The analytical solutions agree well with the computational fluid dynamics (CFD) results. The coupling of a CFD model with the one-dimensional analytical model could capture the impact of local airflow on contaminant transport. This analytical model has been used for analyzing contaminant transport in a 30-row all-economy-class airliner cabin with minimal computing effort. The paper presents a new one-dimensional analytical model that can provide quick information on global airborne contaminant transmissions in airliner cabins for effective response plans. The model can be used to study the effects of air exchange rates, recirculation, efficiency of the high-efficiency particulate air (HEPA) filters and longitudinal airflow on airborne contaminant transport in airliner cabins with minimal computing effort.
Diffusion in concentrated lattice gases. III. Tracer diffusion on a one-dimensional lattice
Beijeren, H. van; Kehr, K.W.; Kutner, R.
1983-01-01
The dynamical process of the diffusion of tagged particles in a one-dimensional concentrated lattice gas is investigated. The particles are noninteracting except that double occupancy is forbidden. The mean-square displacement of a tagged particle is calculated for all times by an approximate theory
DEFF Research Database (Denmark)
Rotvig, J.; Smith, H.; Jauho, Antti-Pekka
1996-01-01
We present an analytical study of one-dimensional semiconductor superlattices in external electric fields, which may be time dependent. A number of general results for the (quasi)energies and eigenstates are derived. An equation of motion for the density matrix is obtained for a two-band model...
Periodic travelling waves in a non-integrable one-dimensional lattice
Valkering, T.P.
1982-01-01
The existence of a one-parameter family of periodic solutions representing longitudinal travelling waves is established for a one-dimensional lattice of identical particles with nearest-neighbour interaction. The potential is not given in closed form but is specified by only a few global properties.
Quantum and semiclassical Husimi distributions for a one-dimensional resonant system
Egydio de Carvalho, R.; de Aguiar, M. A. M.
1992-07-01
We compare exact and semiclassical Husimi distributions for the single eigenstates of a one-dimensional resonant Hamiltonian. We find that both distributions concentrate near the unstable fixed points even when these points are made complex by suitably varying a parameter.
Optical implementations of the Radon-Wigner display for one-dimensional signals.
Zhang, Y; Gu, B Y; Dong, B Z; Yang, G Z
1998-07-15
New optical implementations of the Radon-Wigner display for a one-dimensional signal are proposed based on the fractional Fourier transform. The setups involve only one varifocal lens. Furthermore, the same magnification can be realized simultaneously for all the fractional transform orders, which is quite convenient for practical applications.
Thijssen, Wilhelmus Hendrikus Alphonsus
2007-01-01
This thesis describes the formation and physical properties of atomic chains consisting of metal atoms and incorporated small molecules. Small molecules like oxygen and hydrogen modify the electrical and mechanical properties of these wires, resulting in new one-dimensional conductors.
Thijssen, Wilhelmus Hendrikus Alphonsus
2007-01-01
This thesis describes the formation and physical properties of atomic chains consisting of metal atoms and incorporated small molecules. Small molecules like oxygen and hydrogen modify the electrical and mechanical properties of these wires, resulting in new one-dimensional conductors.
One-dimensional random walk of nanosized liquid Pb inclusions on dislocations in Al
DEFF Research Database (Denmark)
Johnson, E.; Levinsen, M.T.; Steenstrup, S.
2004-01-01
to and perpendicular to the dislocations respectively. Movements parallel to the dislocation lines display properties of partially confined one-dimensional random walks where smaller inclusions can be seen to move over distances that are many times their own sizes. In contrast, the trajectories perpendicular...
Optimally localized Wannier functions for quasi one-dimensional nonperiodic insulators
DEFF Research Database (Denmark)
Cornean, Horia; Nenciu, A.; Nenciu, Gheorghe
It is proved that for general, not necessarily periodic quasi one dimensional systems, the band position operator corresponding to an isolated part of the energy spectrum has discrete spectrum and its eigenfunctions have the same spatial localization as the corresponding spectral projection. As a...
Optimally localized Wannier functions for quasi one-dimensional nonperiodic insulators
DEFF Research Database (Denmark)
Cornean, Horia; Nenciu, A.; Nenciu, Gheorghe
2008-01-01
It is proved that for general, not necessarily periodic, quasi one-dimensional systems the band position operator corresponding to an isolated part of the energy spectrum has discrete spectrum and its eigenfunctions have the same spatial localization as the corresponding spectral projection. As a...
Comparing the Impact of Dynamic and Static Media on Students' Learning of One-Dimensional Kinematics
Mešic, Vanes; Dervic, Dževdeta; Gazibegovic-Busuladžic, Azra; Salibašic, Džana; Erceg, Nataša
2015-01-01
In our study, we aimed to compare the impact of simulations, sequences of printed simulation frames and conventional static diagrams on the understanding of students with regard to the one-dimensional kinematics. Our student sample consisted of three classes of middle years students (N = 63; mostly 15 year-olds). These three classes served as…
Energy Technology Data Exchange (ETDEWEB)
Bellucci, Stefano [INFN-Laboratori Nazionali di Frascati, CP 13, 00044 Frascati (Italy); Trifonov, Andrey Yu [Laboratory of Mathematical Physics, Mathematical Physics Department, Tomsk Polytechnical University, Lenin ave 30, Tomsk, 634050 (Russian Federation)
2005-02-18
Based on Maslov's complex germ method, a semiclassical asymptotic in a class of semiclassically concentrated functions is constructed for the one-dimensional Fokker-Planck equation with a nonlocal nonlinearity. The Einstein-Ehrenfest system describing the dynamics of mean values of coordinates and centred momenta is formulated. A nonlinear transition density is constructed. (letter to the editor)
An SU(2) symmetry of the one-dimensional spin-1 XY model
Kitazawa, A; Nomura, K
2003-01-01
We show that the one-dimensional spin-1 XY model has an additional SU(2) symmetry for the open boundary condition and for an artificial one. We can explain some degeneracies of excitation states which were reported in previous numerical studies. (letter to the editor)
Newton's method for nonlinear stochastic wave equations driven by one-dimensional Brownian motion.
Leszczynski, Henryk; Wrzosek, Monika
2017-02-01
We consider nonlinear stochastic wave equations driven by one-dimensional white noise with respect to time. The existence of solutions is proved by means of Picard iterations. Next we apply Newton's method. Moreover, a second-order convergence in a probabilistic sense is demonstrated.
One-dimensional waveguide coupled to multiple qubits: photon-photon correlations
National Research Council Canada - National Science Library
Fang, Yao-Lung L; Zheng, Huaixiu; Baranger, Harold U
2014-01-01
For a one-dimensional (1D) waveguide coupled to two or three qubits, we show that the photon-photon correlations have a wide variety of behavior, with structure that depends sensitively on the frequency and on the qubit-qubit separation L...
Derivation of Ginzburg-Landau theory for a one-dimensional system with contact interaction
DEFF Research Database (Denmark)
Frank, Rupert; Hanizl, Christian; Seiringer, Robert
2013-01-01
In a recent paper we give the first rigorous derivation of the celebrated Ginzburg-Landau (GL) theory, starting from the microscopic Bardeen-Cooper-Schrieffer (BCS) model. Here we present our results in the simplified case of a one-dimensional system of particles interacting via a delta-potential....
Observation of Zero-Dimensional States in a One-Dimensional Electron Interferometer
Wees, B.J. van; Kouwenhoven, L.P.; Harmans, C.J.P.M.; Williamson, J.G.; Timmering, C.E.; Broekaart, M.E.I.; Foxon, C.T.; Harris, J.J.
1989-01-01
We have studied the electron transport in a one-dimensional electron interferometer. It consists of a disk-shaped two-dimensional electron gas, to which quantum point contacts are attached. Discrete zero-dimensional states are formed due to constructive interference of electron waves traveling along
Magnetic properties of a quasi-one-dimensional S=1/2 antiferromagnet: Copper benzoate
DEFF Research Database (Denmark)
Dender, D.C.; Davidovic, D.; Reich, D.H.
1996-01-01
We use magnetic susceptibility and inelastic neutron scattering measurements to show that copper benzoate, Cu(C6D5COO)(2) . 3D(2)O, is a quasi-one-dimensional S=1/2 antiferromagnet with an exchange constant J=1.57 meV Below T=0.8 K a ferromagnetic contribution to the susceptibility marks the onset...
Mahoney, Joyce; And Others
1988-01-01
Evaluates 16 commercially available courseware packages covering topics for introductory physics. Discusses the price, sub-topics, program type, interaction, time, calculus required, graphics, and comments of each program. Recommends two packages in measurement and vectors, and one-dimensional motion respectively. (YP)
Semi-analytical Study of a One-dimensional Contaminant Flow in a ...
African Journals Online (AJOL)
ADOWIE PERE
1,2,3,4Department of Mathematics, Federal University of Technology, Minna, Nigeria. *Corresponding author E-mail: razaq.jimoh@futminna.edu.ng. ABSTRACT: The Bubnov-Galerkin weighted residual method was used to solve a one- dimensional contaminant flow problem in this paper. The governing equation of the.
Validation of the one-dimensional compositional reservoir simulator (CRSIM-1D): Technical note
Energy Technology Data Exchange (ETDEWEB)
Klara, S.M.; Holifield, T.F.
1987-11-01
The analysis presented in this manuscript validates the one-dimensional compositional reservoir simulator (CRSIM-1D). CRSIM-1D was developed at the Morgantown Energy Technology Center (METC), and is the first stage of an ongoing investigation of methods for increasing sweep efficiency of miscible EOR carbon dioxide (CO/sub 2/) floods. After its development, the simulator was validated to (1) ensure reliable predictions, (2) understand the sensitivity of input parameters, and (3) identify stability limitations of the code. The results from this study are presented in this report. The first part of this report summarized the results from the comparison of predictions from CRSIM-1D with both experimental data and the predictions from simulators. Four problems from the literature were examined: (1) 3-component oil displaced by a rich gas using single-point upstream weighting, (2) 3-component oil displaced by a rich gas using two-point upstream weighting, (3) 3-component oil displaced by a lean gas, and (4) 15-component oil displaced by CO/sub 2/. In all cases, the results from CRSIM-1D compare well with the results from the literature. Additionally, this report discusses the sensitivity of CRSIM-1D with regard to computational and physical variables. Sensitivities were evaluated for a wide range of physical variables (injection rate, porosity, etc.) and computational variables (time step size and grid size). Part of this evaluation compares CRSIM-1D's predictions to exact solutions that exist for simple problems such as incompressible immiscible floods. These comparisons should provide potential users with insight into the accuracy of predictions from CRSIM-1D. 18 refs., 15 tabs.
Dynamic simulation of wavy-stratified two-phase flow with the one-dimensional two-fluid model
Fullmer, William D.
The one-dimensional two-fluid model is the basis for the description of the transport of mass, momentum and energy in the thermal-hydraulic codes used for nuclear reactor safety analysis. Unlike other physical transport models, the one-dimensional two-fluid model suffers from the possibility of being ill-posed as an initial-boundary value problem depending on the flow conditions and the relevant physical closure laws. Typically, the ill-posedness is dealt with through either excessive numerical damping or the addition of unphysical closure laws designed for the sole purpose of hyperbolization. Unfortunately both methods eliminate the instability along with the problem of ill-posedness causing the model to undoubtedly lose some of its inherent dynamic capability. In this work, a one-dimensional two-fluid model for horizontal or slightly inclined stratified flow is developed. Higher order physical models that are often neglected, such as surface tension and axial viscous stress, are retained for their short-wavelength stability properties. Characteristic, dispersion and nonlinear analyses are performed to demonstrate that the resulting model is linearly well-posed and nonlinearly well-behaved. While it has been known that higher-order differential terms are able to regularize the short-wavelength problem of ill-posedness without removing the long-wavelength instability, the literature is relatively silent on the consequences of using a model under linearly unstable conditions. Using carefully selected conditions in an idealized infinite domain, it is demonstrated for the first time that the one-dimensional two-fluid model exhibits chaotic behavior in addition to limit cycles and asymptotic stability. The chaotic behavior is a consequence of the long-wavelength linear instability (energy source) the nonlinearity (energy transfer) and the short-wavelength dissipation (energy sink). Since the model is chaotic, solutions exhibit a sensitive dependence on initial
National Research Council Canada - National Science Library
Al-Hummayani, Fadia M
2016-01-01
.... This case report represents a none traditional treatment modality to treat deep anterior crossbite in an adult pseudo class III malocclusion complicated by severely retruded, supraerupted upper and lower incisors...
Energy Technology Data Exchange (ETDEWEB)
Lopez, C.; Koski, J.A.; Razani, A.
2000-01-06
A study of the errors introduced when one-dimensional inverse heat conduction techniques are applied to problems involving two-dimensional heat transfer effects was performed. The geometry used for the study was a cylinder with similar dimensions as a typical container used for the transportation of radioactive materials. The finite element analysis code MSC P/Thermal was used to generate synthetic test data that was then used as input for an inverse heat conduction code. Four different problems were considered including one with uniform flux around the outer surface of the cylinder and three with non-uniform flux applied over 360{degree}, 180{degree}, and 90{degree} sections of the outer surface of the cylinder. The Sandia One-Dimensional Direct and Inverse Thermal (SODDIT) code was used to estimate the surface heat flux of all four cases. The error analysis was performed by comparing the results from SODDIT and the heat flux calculated based on the temperature results obtained from P/Thermal. Results showed an increase in error of the surface heat flux estimates as the applied heat became more localized. For the uniform case, SODDIT provided heat flux estimates with a maximum error of 0.5% whereas for the non-uniform cases, the maximum errors were found to be about 3%, 7%, and 18% for the 360{degree}, 180{degree}, and 90{degree} cases, respectively.
Energy Technology Data Exchange (ETDEWEB)
Harmony, S.C.; Steiner, J.L.; Stumpf, H.J.; Lime, J.F.; Boyack, B.E.
1993-12-31
The PIUS advanced reactor is a 640-MWe pressurized water reactor developed by Asea Brown Boveri (ABB). A unique feature of the PIUS concept is the absence of mechanical control and shutdown rods. Reactivity is controlled by coolant boron concentration and the temperature of the moderator coolant. As part of the preapplication and eventual design certification process, advanced reactor applicants are required to submit neutronic and thermal-hydraulic safety analyses over a sufficient range of normal operation, transient conditions, and specified accident sequences. Los Alamos is supporting the US Nuclear Regulatory Commission`s preapplication review of the PIUS reactor. A fully one-dimensional model of the PIUS reactor has been developed for the Transient Reactor Analysis Code, TRACPF1/MOD2. Early in 1992, ABB submitted a Supplemental Information Package describing recent design modifications. An important feature of the PIUS Supplement design was the addition of an active scram system that will function for most transient and accident conditions. A one-dimensional Transient Reactor Analysis Code baseline calculation of the PIUS Supplement design were performed for a break in the main steam line at the outlet nozzle of the loop 3 steam generator. Sensitivity studies were performed to explore the robustness of the PIUS concept to severe off-normal conditions following a main steam line break. The sensitivity study results provide insights into the robustness of the design.
Zheng, Guo; Wang, Jue; Wang, Lin; Zhou, Muchun; Chen, Yanru; Song, Minmin
2018-03-01
The scintillation index of pseudo-Bessel-Gaussian Schell-mode (PBGSM) beams propagating through atmospheric turbulence is analyzed with the help of wave optics simulation due to the analytic difficulties. It is found that in the strong fluctuation regime, the PBGSM beams are more resistant to the turbulence with the appropriate parameters β and δ . However, the case is contrary in the weak fluctuation regime. Our simulation results indicate that the PBGSM beams may be applied to free-space optical (FSO) communication systems only when the turbulence is strong or the propagation distance is long.
Universality of One-Dimensional Reversible and Number-Conserving Cellular Automata
Directory of Open Access Journals (Sweden)
Kenichi Morita
2012-08-01
Full Text Available We study one-dimensional reversible and number-conserving cellular automata (RNCCA that have both properties of reversibility and number-conservation. In the case of 2-neighbor RNCCA, García-Ramos proved that every RNCCA shows trivial behavior in the sense that all the signals in the RNCCA do not interact each other. However, if we increase the neighborhood size, we can find many complex RNCCAs. Here, we show that for any one-dimensional 2-neighbor reversible partitioned CA (RPCA with s states, we can construct a 4-neighbor RNCCA with 4s states that simulates the former. Since it is known that there is a computationally universal 24-state 2-neighbor RPCA, we obtain a universal 96-state 4-neighbor RNCCA.
One-dimensional CdS nanostructures: a promising candidate for optoelectronics.
Li, Huiqiao; Wang, Xi; Xu, Junqi; Zhang, Qi; Bando, Yoshio; Golberg, Dmitri; Ma, Ying; Zhai, Tianyou
2013-06-11
As a promising candidate for optoelectronics, one-dimensional CdS nanostructures have drawn great scientific and technical interest due to their interesting fundamental properties and possibilities of utilization in novel promising optoelectronical devices with augmented performance and functionalities. This progress report highlights a selection of important topics pertinent to optoelectronical applications of one-dimensional CdS nanostructures over the last five years. This article begins with the description of rational design and controlled synthesis of CdS nanostructure arrays, alloyed nanostructucures and kinked nanowire superstructures, and then focuses on the optoelectronical properties, and applications including cathodoluminescence, lasers, light-emitting diodes, waveguides, field emitters, logic circuits, memory devices, photodetectors, gas sensors, photovoltaics and photoelectrochemistry. Finally, the general challenges and the potential future directions of this exciting area of research are highlighted. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
An algorithm for engineering regime shifts in one-dimensional dynamical systems
Tan, James P. L.
2018-01-01
Regime shifts are discontinuous transitions between stable attractors hosting a system. They can occur as a result of a loss of stability in an attractor as a bifurcation is approached. In this work, we consider one-dimensional dynamical systems where attractors are stable equilibrium points. Relying on critical slowing down signals related to the stability of an equilibrium point, we present an algorithm for engineering regime shifts such that a system may escape an undesirable attractor into a desirable one. We test the algorithm on synthetic data from a one-dimensional dynamical system with a multitude of stable equilibrium points and also on a model of the population dynamics of spruce budworms in a forest. The algorithm and other ideas discussed here contribute to an important part of the literature on exercising greater control over the sometimes unpredictable nature of nonlinear systems.
Energy Technology Data Exchange (ETDEWEB)
Chen Zhongsheng, E-mail: czs_study@sina.com [Key Laboratory of Science and Technology on Integrated Logistics Support, College of Mechatronic Engineering and Automation, National University of Defense Technology, Changsha, Hunan 410073 (China); Yang Yongmin; Lu Zhimiao; Luo Yanting [Key Laboratory of Science and Technology on Integrated Logistics Support, College of Mechatronic Engineering and Automation, National University of Defense Technology, Changsha, Hunan 410073 (China)
2013-02-01
Nowadays broadband vibration energy harvesting using piezoelectric effect has become a research hotspot. The innovation in this paper is the widening of the resonant bandwidth of a piezoelectric harvester based on phononic band gaps, which is called one-dimensional phononic piezoelectric cantilever beams (PPCBs). Broadband characteristics of one-dimensional PPCBs are analyzed deeply and the vibration band gap can be calculated. The effects of different parameters on the vibration band gap are presented by both numerical and finite element simulations. Finally experimental tests are conducted to validate the proposed method. It can be concluded that it is feasible to use the PPCB for broadband vibration energy harvesting and there should be a compromise among related parameters for low-frequency vibrations.
Thermal Conductivity of the One-Dimensional Fermi-Hubbard Model.
Karrasch, C; Kennes, D M; Heidrich-Meisner, F
2016-09-09
We study the thermal conductivity of the one-dimensional Fermi-Hubbard model at a finite temperature using a density matrix renormalization group approach. The integrability of this model gives rise to ballistic thermal transport. We calculate the temperature dependence of the thermal Drude weight at half filling for various interaction strengths. The finite-frequency contributions originating from the fact that the energy current is not a conserved quantity are investigated as well. We report evidence that breaking the integrability through a nearest-neighbor interaction leads to vanishing Drude weights and diffusive energy transport. Moreover, we demonstrate that energy spreads ballistically in local quenches with initially inhomogeneous energy density profiles in the integrable case. We discuss the relevance of our results for thermalization in ultracold quantum-gas experiments and for transport measurements with quasi-one-dimensional materials.
Topologically protected mid-gap states induced by impurity in one-dimensional superlattices
Lang, Li-Jun; Chen, Shu
2014-03-01
Based on the discovery of the nontrivial topological properties of one-dimensional superlattices, we show that mid-gap states emerge in such systems induced by a single on-site impurity. Besides the trivial bound state located at the impurity site, these mid-gap states are localized at the adjacent sites of the impurity in the limit of a strongly attractive/repulsive impurity potential, behaving as edge states under open boundary conditions and thus carrying the information of topological properties. This feature makes it possible to reveal the topological properties of superlattices via the impurity effect and to realize the adiabatic pumping between the opposite sides of the impurity in setups of one-dimensional optical lattices or photonic crystals.
Click polymerization and characterization of TiO2 nanoparticles to one-dimensional nanochains
Xia, Ru; Ruan, Zheng; Zhang, Yujiao; Zhu, Hui; Cao, Ming; Chen, Peng; Miao, Jibin; Qian, Jiasheng
2017-11-01
In this paper, one-dimensional TiO2 nanochains were prepared by polymerization of azide-alkyne click reactions. As a first step, the TiO2 nanoparticles (NPs) were esterified with 2-bromopropionic bromide, grafted by atom transfer radical polymerization (ATRP) of styrene, followed by azidation (TiO2sbnd PSsbnd N3). Second, another part of the TiO2 NPs were modified by propargyl bromide (TiO2sbnd Ctbnd CH). By azide-alkyne click reactions between the azide and alkyne-terminated TiO2 NPs, one-dimensional TiO2 nanochains linked by polystyrene (PS) was successfully synthesized. The chemical structure of the product was characterized using FTIR, TGA and TEM.
Energy Technology Data Exchange (ETDEWEB)
Khater, Antoine; Szczesniak, Dominik [Laboratoire de Physique de l' Etat Condense UMR 6087, Universite du Maine, 72085 Le Mans (France)
2011-04-01
An analytical model is presented for the electronic conductance in a one dimensional atomic chain across an isolated defect. The model system consists of two semi infinite lead atomic chains with the defect atom making the junction between the two leads. The calculation is based on a linear combination of atomic orbitals in the tight-binding approximation, with a single atomic one s-like orbital chosen in the present case. The matching method is used to derive analytical expressions for the scattering cross sections for the reflection and transmission processes across the defect, in the Landauer-Buttiker representation. These analytical results verify the known limits for an infinite atomic chain with no defects. The model can be applied numerically for one dimensional atomic systems supported by appropriate templates. It is also of interest since it would help establish efficient procedures for ensemble averages over a field of impurity configurations in real physical systems.
Single-polaron properties in the one-dimensional Holstein and SSH models
Energy Technology Data Exchange (ETDEWEB)
Liu, Qingmei, E-mail: nosilentlamb@yahoo.com.cn [Department of Physics, Renmin University of China, 100872 Beijing (China)
2012-03-05
We study the single-polaron properties of the one-dimensional Holstein and SSH model. The dynamical coherent potential approximation (under the Hartree approximation) is applied to compute the polaron dispersion, the quasi-particle residue, and the polaron's Green's functions. We compare our calculated results in comparison with those by the self-consistent Born approximation plus higher-order diagrams. -- Highlights: ► We study the single-polaron properties of the one-dimensional Holstein and SSH model. ► The dynamical coherent potential approximation of Hartree type is used. ► The self-consistent Born approximation (SCBA) plus higher-order diagrams is compared. ► The SCBA method is only limited to the weak electron–phonon case for the both models.
One-dimensional flame instability and control of burning in fire-chamber
Directory of Open Access Journals (Sweden)
Victor E. Volkov
2015-03-01
Full Text Available The flame stability with regard to one-dimensional exponential perturbations both for the combustion in the fire-chamber and the flame propagating in closed tubes or chambers is investigated. It is proved that both stability and instability are possible for the combustion process. At the same time the one-dimensional flame instability is guaranteed near the front wall of the fire-chamber where the fuel supply is realized. Therefore the control of combustion in the fire-chamber leads to support of the flame at the maximum possible distance from the front wall of the fire-chamber to prevent the vibratory combustion or to diminish intensity of pulsations if these pulsations are inevitable.
Advances in one-dimensional wave mechanics towards a unified classical view
Cao, Zhuangqi
2014-01-01
Advances in One-Dimensional Wave Mechanics provides a comprehensive description of the motion of microscopic particles in one-dimensional, arbitrary-shaped potentials based on the analogy between Quantum Mechanics and Electromagnetism. Utilizing a deeper understanding of the wave nature of matter, this book introduces the concept of the scattered sub-waves and a series of new analytical results using the Analytical Transfer Matrix (ATM) method. This work will be useful for graduate students majoring in physics, mainly in basic quantum theory, as well as for academic researchers exploring electromagnetism, particle physics, and wave mechanics and for experts in the field of optical waveguide and integrated optics. Prof. Zhuangqi Cao is a Professor of Physics at Shanghai Jiao Tong University, China. Dr. Cheng Yin is a teacher at Jiangsu Key Laboratory of Power Transmission and Distribution Equipment Technology, Hohai University, China.
Mechanical Unfolding of a Simple Model Protein Goes Beyond the Reach of One-Dimensional Descriptions
Tapia-Rojo, Rafael; Mazo, Juan José; Falo, Fernando
2015-01-01
We study the mechanical unfolding of a simple model protein. The Langevin dynamics results are analyzed using Markov-model methods which allow to describe completely the configurational space of the system. Using transition path theory we also provide a quantitative description of the unfolding pathways followed by the system. Our study shows a complex dynamical scenario. In particular, we see that the usual one-dimensional picture: free-energy vs end-to-end distance representation, gives a misleading description of the process. Unfolding can occur following different pathways and configurations which seem to play a central role in one-dimensional pictures are not the intermediate states of the unfolding dynamics.
One-dimensional half-metallic interfaces of two-dimensional honeycomb insulators
Bristowe, N. C.; Stengel, Massimiliano; Littlewood, P. B.; Artacho, Emilio; Pruneda, J. M.
2013-10-01
We study zigzag interfaces between insulating compounds that are isostructural to graphene, specifically II-VI, III-V, and IV-IV two-dimensional honeycomb insulators. We show that these one-dimensional interfaces are polar, with a net density of excess charge that can be simply determined by using the ideal (integer) formal valence charges, regardless of the predominant covalent character of the bonding in these materials. We justify this finding on fundamental physical grounds by analyzing the topology of the formal polarization lattice in the parent bulk materials. First-principles calculations elucidate an electronic compensation mechanism not dissimilar to oxide interfaces, which is triggered by a Zener-like charge transfer between interfaces of opposite polarity. In particular, we predict the emergence of one-dimensional electron and hole gases, which in some cases are ferromagnetic half metallic.
Directory of Open Access Journals (Sweden)
ZHAO Xuefen
2016-06-01
Full Text Available This paper considers the adhesive contact problem in aperiodical plane of one-dimensional hexagonal quasicrystals. By complex variable method, the adhesive contact problem is converted into a Riemann-Hilbert boundary problem. By solving that, we obtain the explicit expressions of stress functions and contact stress for a rigid flat punch. The results how that: (1 the contact displacement is proportional to the indentation force under a flat rigid punch; (2 The contact stress exhibits the oscillatory singularities at the edge of the contact zone. Because phonon field and phason field are coupled in one-dimensional hexagonal quasicrystals, the distribution of contact stress under punch is different from the results of contact problems in the classical elasticity theory. Without the contribution of phason field, the above solutions degenerate into the classical ones. Here is the abstract of your article.
Performance of parallel computation using CUDA for solving the one-dimensional elasticity equations
Darmawan, J. B. B.; Mungkasi, S.
2017-01-01
In this paper, we investigate the performance of parallel computation in solving the one-dimensional elasticity equations. Elasticity equations are usually implemented in engineering science. Solving these equations fast and efficiently is desired. Therefore, we propose the use of parallel computation. Our parallel computation uses CUDA of the NVIDIA. Our research results show that parallel computation using CUDA has a great advantage and is powerful when the computation is of large scale.
One-Dimensional Hole Gas in Germanium/Silicon Nanowire Heterostructures
Lu, Wei; Xiang, Jie; Timko, Brian P.; Wu, Yue; Lieber, Charles M.
2005-01-01
Two-dimensional electron and hole gas systems, enabled through band structure design and epitaxial growth on planar substrates, have served as key platforms for fundamental condensed matter research and high-performance devices. The analogous development of one-dimensional (1D) electron or hole gas systems through controlled growth on 1D nanostructure substrates, which could open up opportunities beyond existing carbon nanotube and nanowire systems, has not been realized. Here, we report the ...
Electronic structure of the quasi-one-dimensional organic conductor TTF-TCNQ
DEFF Research Database (Denmark)
Sing, M.; Schwingenschlögl, U.; Claessen, R.
2003-01-01
We study the electronic structure of the quasi-one-dimensional organic conductor TTF-TCNQ by means of density-functional band theory, Hubbard model calculations, and angle-resolved photoelectron spectroscopy (ARPES). The experimental spectra reveal significant quantitative and qualitative......-dimensional Hubbard model for the low-energy spectral behavior is attributed to interchain coupling and the additional effect of electron-phonon interaction....
One-dimensional structures behind twisted and untwisted superYang-Mills theory
Baulieu, Laurent
2011-01-01
We give a one-dimensional interpretation of the four-dimensional twisted N=1 superYang-Mills theory on a Kaehler manifold by performing an appropriate dimensional reduction. We prove the existence of a 6-generator superalgebra, which does not possess any invariant Lagrangian but contains two different subalgebras that determine the twisted and untwisted formulations of the N=1 superYang-Mills theory.
Dynamical properties of photogenerated polarons in one-dimensional dimerized Mott Insulators
Moriya, K.; Maeshima, N.; Hino, K. I.
2012-10-01
We study physical properties of photogenerated electron-lattice coupled states, polarons, in one-dimensional (1D) Peierls-Hubbard model with classical lattice distortion by means of the density matrix renormalization group method. The numerical results show novel midgap peaks in optical response spectra of polarons for large on-site Coulomb interaction U. These midgap peaks originate from charge-transfer excitations within the dimer in polarons.
Matsueda, H.; Tohyama, T.; Maekawa, S.
2004-01-01
One-dimensional Mott insulators exhibit giant nonlinear optical response. Based on the dynamical density matrix renormalization group method, photoexcited states and optical response in the insulators are studied as functions of the on-site and the nearest neighbor Coulomb interactions, $U$ and $V$, respectively. We find that the lowest optically-allowed and forbidden excited states, which have odd and even parities, respectively, are degenerate for $V/t\\ltsim 2$ with $t$ being the hopping in...
Directory of Open Access Journals (Sweden)
Rai Nath Kabindra Rajeev
2009-01-01
Full Text Available In this paper, the solution of the one dimensional moving boundary problem with periodic boundary conditions is obtained with the help of variational iterational method. By using initial and boundary values, the explicit solutions of the equations have been derived, which accelerate the rapid convergence of the series solution. The method performs extremely well in terms of efficiency and simplicity. The temperature distribution and the position of moving boundary are evaluated and numerical results are presented graphically.
Adomian decomposition method used to solve the one-dimensional acoustic equations
Dispini, Meta; Mungkasi, Sudi
2017-05-01
In this paper we propose the use of Adomian decomposition method to solve one-dimensional acoustic equations. This recursive method can be calculated easily and the result is an approximation of the exact solution. We use the Maple software to compute the series in the Adomian decomposition. We obtain that the Adomian decomposition method is able to solve the acoustic equations with the physically correct behavior.
One-dimensional metallic edge states in MoS2
DEFF Research Database (Denmark)
Bollinger, Mikkel; Lauritsen, J.V.; Jacobsen, Karsten Wedel
2001-01-01
By the use of density functional calculations it is shown that the edges of a two-dimensional slab of insulating MoS2 exhibit several metallic states. These edge states can be viewed as one-dimensional conducting wires, and we show that they can be observed directly using scanning tunneling...... microscopy for single-layer MoS2 nanoparticles grown on a support....
Quasi-one-dimensional ballistic ring in the field of circularly polarized electromagnetic wave
Epshtein, E. M.; Fedorov, E. G.; Shmelev, G. M.
2004-01-01
Dynamics is studied of an electron in a quasi-one-dimensional ballistic ring under circularly polarized electromagnetic field propagating along the normal to the ring plane. The average emission intensity from the ring is calculated. The value and direction of the electron average angular velocity in the ring depend on the incident wave parameters. It is found that the ring average dipole moment can remain constant under certain conditions. Possibility is shown of higher harmonics enhancement...
Comment on 'Absolute negative mobility in a one-dimensional overdamped system'
Spiechowicz, J.; Kostur, M.; Łuczka, J.
2016-04-01
Recently Ru-Yin Chen et al. (Phys. Lett. A 379 (2015) 2169-2173) presented results on the absolute negative mobility (ANM) in a one-dimensional overdamped system and claimed that a new minimal model of ANM was proposed. We suggest that the authors introduced a mistake in their calculations. Then we perform a precise numerical simulation of the corresponding Langevin equation to show that the ANM phenomenon does not occur in the considered system.
Electric-field-induced interferometric resonance of a one-dimensional spin-orbit-coupled electron
Jingtao Fan; Yuansen Chen; Gang Chen; Liantuan Xiao; Suotang Jia; Franco Nori
2016-01-01
The efficient control of electron spins is of crucial importance for spintronics, quantum metrology, and quantum information processing. We theoretically formulate an electric mechanism to probe the electron spin dynamics, by focusing on a one-dimensional spin-orbit-coupled nanowire quantum dot. Owing to the existence of spin-orbit coupling and a pulsed electric field, different spin-orbit states are shown to interfere with each other, generating intriguing interference-resonant patterns. We ...
Moving Least Squares Method for a One-Dimensional Parabolic Inverse Problem
Directory of Open Access Journals (Sweden)
Baiyu Wang
2014-01-01
Full Text Available This paper investigates the numerical solution of a class of one-dimensional inverse parabolic problems using the moving least squares approximation; the inverse problem is the determination of an unknown source term depending on time. The collocation method is used for solving the equation; some numerical experiments are presented and discussed to illustrate the stability and high efficiency of the method.
Competition between spin and charge order in a one-dimensional lattice
Talebi, Amir Hossein; Davoudi, Bahman; Rahimitabar, M. Reza
2017-10-01
In this paper, we study the presence of competing instabilities in one-dimensional (1D) extended Hubbard model (EHM). Using the extended two-particle self-consistent approximation (ETPSC), we derive the density and interaction dependent crossover diagram for spin and charge density wave fluctuations at arbitrary wave number. We determine the phase transitions of the system by means of spin and charge susceptibilities. We draw the phase diagram which separates different phases of the model for several effective particle densities.
Influence of the modulated hopping on the one-dimensional interacting electron system
Ding, Hanqin; Zhang, Jun
2015-10-01
By introducing a modulation parameter (ξ), we study the one-dimensional correlated system with modulated hopping, on-site (U) and nearest-neighbor (V) repulsions in the weak-coupling regime. The induced three-body attraction changes topology of the conventional phase diagram. Besides the usual CDW and SDW phases, a BSDW phase exists for | U - 2 V | √{ πU / 8 t }. Phenomenologically, the general quantum phase diagram including insulating and superconducting phases is discussed.
Pressure-induced recovery of Fourier's law in one dimensional momentum-conserving systems
Sato, Dye SK
2015-01-01
We report the two typical models of normal heat conduction in one dimensional momentum-conserving systems. They show the Arrhenius and the non-Arrhenius temperature dependence. We construct the two corresponding phenomenologies, transition-state theory of thermally activated dissociation and the pressure-induced crossover between two fixed points in fluctuating hydrodynamics. Compressibility yields the ballistic fixed point, whose scaling is observed in FPU-\\beta lattices.
Pressure-induced recovery of Fourier's law in one-dimensional momentum-conserving systems
Sato, Dye SK
2016-07-01
We report the two typical models of normal heat conduction in one-dimensional momentum-conserving systems. They show the Arrhenius and the non-Arrhenius temperature dependence. We construct the two corresponding phenomenologies, transition-state theory of thermally activated dissociation and the pressure-induced crossover between two fixed points in fluctuating hydrodynamics. Compressibility yields the ballistic fixed point, whose scaling is observed in Fermi-Pasta-Ulam (FPU) β lattices.
Inoue, Makoto
2017-12-01
Some new formulae of the canonical correlation functions for the one dimensional quantum transverse Ising model are found by the ST-transformation method using a Morita's sum rule and its extensions for the two dimensional classical Ising model. As a consequence we obtain a time-independent term of the dynamical correlation functions. Differences of quantum version and classical version of these formulae are also discussed.
Figure of Merit of one-dimensional resonant transmission systems in the quantum regime
Çipiloğlu, Mustafa Ali; Turgut, Sadi
2006-01-01
The figure of merit, ZT, for a one-dimensional conductor displaying a Lorentzian resonant transmission probability is calculated. The optimum working conditions for largest ZT values are determined. It is found that, the resonance energy has to be adjusted to be several resonance widths away from the Fermi level. Similarly it is better for the temperature to be equal to several resonance widths. The approximate relationships, which can be a fairly good guide for designing devices, between dif...
A GENETIC ALGORITHM FOR THE ONE-DIMENSIONAL CUTTING STOCK PROBLEM WITH SETUPS
Araujo, S.A. de; Poldi, K. C.; Smith, J.
2014-01-01
This paper investigates the one-dimensional cutting stock problem considering two conflicting objective functions: minimization of both the number of objects and the number of different cutting patterns used. A new heuristic method based on the concepts of genetic algorithms is proposed to solve the problem. This heuristic is empirically analyzed by solving randomly generated instances and also practical instances from a chemical-fiber company. The computational results show that the method i...
One-Dimensional Oxide Nanostructures as Gas-Sensing Materials: Review and Issues
Kyoung Jin Choi; Ho Won Jang
2010-01-01
In this article, we review gas sensor application of one-dimensional (1D) metal-oxide nanostructures with major emphases on the types of device structure and issues for realizing practical sensors. One of the most important steps in fabricating 1D-nanostructure devices is manipulation and making electrical contacts of the nanostructures. Gas sensors based on individual 1D nanostructure, which were usually fabricated using electron-beam lithography, have been a platform technology for fundamen...
A study of the one dimensional total generalised variation regularisation problem
Papafitsoros, Konstantinos
2015-03-01
© 2015 American Institute of Mathematical Sciences. In this paper we study the one dimensional second order total generalised variation regularisation (TGV) problem with L2 data fitting term. We examine the properties of this model and we calculate exact solutions using simple piecewise affine functions as data terms. We investigate how these solutions behave with respect to the TGV parameters and we verify our results using numerical experiments.
One-dimensional liquid He 4: dynamical properties beyond Luttinger-Liquid theory
Bertaina, G.; Motta, M.; Rossi, M.; Vitali, E.; Galli, D. E.
2016-01-01
We compute the zero-temperature dynamical structure factor of one-dimensional liquid $^4$He by means of state-of-the-art Quantum Monte Carlo and analytic continuation techniques. By increasing the density, the dynamical structure factor reveals a transition from a highly compressible critical liquid to a quasi-solid regime. In the low-energy limit, the dynamical structure factor can be described by the quantum hydrodynamic Luttinger liquid theory, with a Luttinger parameter spanning all possi...
Numerical study of defibrillation mechanisms using a one-dimensional model of cardiac tissue
Simic, A.; Bragard, J.
2015-01-01
In the study presented in this thesis we have used one-dimensional model to study mechanisms associated with the application of the external stimulus to the cardiac tissue. Arrhythmic dynamics is approximated with the reentrant wave on a ring of cardiac tissue. Successful defibrillation is modeled with the complete removal of the reentrant dynamics. The propagation of the electrical signal is modeled with the bidomain model, while cellular membrane current is modeled with the modified Beeler-...
Quasi-one-dimensional modes in strip plates: Theory and experiment
Energy Technology Data Exchange (ETDEWEB)
Arreola, A.; Báez, G. [Departamento de Ciencias Básicas, Universidad Autónoma Metropolitana-Azcapotzalco, Apartado Postal 21-267, 04000 México Distrito Federal (Mexico); Méndez-Sánchez, R. A. [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Apartado Postal 48-3, 62251 Cuernavaca, Morelos (Mexico)
2014-01-14
Using acoustic resonance spectroscopy we measure the elastic resonances of a strip rectangular plate with all its ends free. The experimental setup consist of a vector network analyzer, a high-fidelity audio amplifier, and electromagnetic-acoustic transducers. The one-dimensional modes are identified from the measured spectra by comparing them with theoretical predictions of compressional and bending modes of the plate modeled as a beam. The agreement between theory and experiment is excellent.
Spatial mapping and statistical reproducibility of an array of 256 one-dimensional quantum wires
Energy Technology Data Exchange (ETDEWEB)
Al-Taie, H., E-mail: ha322@cam.ac.uk; Kelly, M. J. [Centre for Advanced Photonics and Electronics, Electrical Engineering Division, Department of Engineering, 9 J. J. Thomson Avenue, University of Cambridge, Cambridge CB3 0FA (United Kingdom); Cavendish Laboratory, Department of Physics, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Smith, L. W.; Lesage, A. A. J.; Griffiths, J. P.; Beere, H. E.; Jones, G. A. C.; Ritchie, D. A.; Smith, C. G. [Cavendish Laboratory, Department of Physics, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom); See, P. [National Physical Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW (United Kingdom)
2015-08-21
We utilize a multiplexing architecture to measure the conductance properties of an array of 256 split gates. We investigate the reproducibility of the pinch off and one-dimensional definition voltage as a function of spatial location on two different cooldowns, and after illuminating the device. The reproducibility of both these properties on the two cooldowns is high, the result of the density of the two-dimensional electron gas returning to a similar state after thermal cycling. The spatial variation of the pinch-off voltage reduces after illumination; however, the variation of the one-dimensional definition voltage increases due to an anomalous feature in the center of the array. A technique which quantifies the homogeneity of split-gate properties across the array is developed which captures the experimentally observed trends. In addition, the one-dimensional definition voltage is used to probe the density of the wafer at each split gate in the array on a micron scale using a capacitive model.
Plasmonic photocatalytic reactions enhanced by hot electrons in a one-dimensional quantum well
Directory of Open Access Journals (Sweden)
H. J. Huang
2015-11-01
Full Text Available The plasmonic endothermic oxidation of ammonium ions in a spinning disk reactor resulted in light energy transformation through quantum hot charge carriers (QHC, or quantum hot electrons, during a chemical reaction. It is demonstrated with a simple model that light of various intensities enhance the chemical oxidization of ammonium ions in water. It was further observed that light illumination, which induces the formation of plasmons on a platinum (Pt thin film, provided higher processing efficiency compared with the reaction on a bare glass disk. These induced plasmons generate quantum hot electrons with increasing momentum and energy in the one-dimensional quantum well of a Pt thin film. The energy carried by the quantum hot electrons provided the energy needed to catalyze the chemical reaction. The results indicate that one-dimensional confinement in spherical coordinates (i.e., nanoparticles is not necessary to provide an extra excited state for QHC generation; an 8 nm Pt thin film for one-dimensional confinement in Cartesian coordinates can also provide the extra excited state for the generation of QHC.
Ground State of the One Dimensional Heisenberg Model with NNN Interactions
Mancini, J. D.; Fessatidis, V.; Bowen, S. P.; Maly, J.; Murawski, R. K.
A great number of insights into a variety of complex physical many-body systems have been gleaned from the study of the of the one-dimensional Heisenberg model. There exists a number of quasi one-dimensional inorganic compounds such as TTF - CUS4C4(CF3) 4 , SRCU2O3 , VO2P2O7 and CuGeO3 for which this Hamiltonian system is relevant. For this work we shall study the one-dimensional Heisenberg Model with nearest, next nearest and next -next nearest interactions. The Hamiltonian is given by: H =J1 ∑ ksk .sk + 1 +J2 ∑ ksk .sk + 2 +J3 ∑ ksk .sk + 3 where sk represents the spin 1 / 2 operator along a chain of N sites and periodic boundary conditions is assumed for the closed chain. We note that it is further possible to describe the Coulomb interaction subject to the Pauli exclusion principle for two quantum dots an XY model. Here we shall study the ground-state energy as well as the energy gap of this system using both a Lanczos (tridiagonal) scheme as well as a generalized Moments approach.
Energy Technology Data Exchange (ETDEWEB)
Stephanopoulos, Nicholas [Univ. of California, Berkeley, CA (United States); Liu, Minghui [Arizona State Univ., Tempe, AZ (United States); Tong, Gary J [Univ. of California, Berkeley, CA (United States); Li, Zhe [Arizona State Univ., Tempe, AZ (United States); Liu, Yan [Arizona State Univ., Tempe, AZ (United States); Yan, Hao [Arizona State Univ., Tempe, AZ (United States); Francis, Matthew B [Univ. of California, Berkeley, CA (United States)
2010-06-24
DNA origami was used as a scaffold to arrange spherical virus capsids into one-dimensional arrays with precise nanoscale positioning. To do this, we first modified the interior surface of bacteriophage MS2 capsids with fluorescent dyes as a model cargo. An unnatural amino acid on the external surface was then coupled to DNA strands that were complementary to those extending from origami tiles. Two different geometries of DNA tiles (rectangular and triangular) were used. The capsids associated with tiles of both geometries with virtually 100% efficiency under mild annealing conditions, and the location of capsid immobilization on the tile could be controlled by the position of the probe strands. The rectangular tiles and capsids could then be arranged into one-dimensional arrays by adding DNA strands linking the corners of the tiles. The resulting structures consisted of multiple capsids with even spacing (~100 nm). We also used a second set of tiles that had probe strands at both ends, resulting in a one-dimensional array of alternating capsids and tiles. This hierarchical self-assembly allows us to position the virus particles with unprecedented control and allows the future construction of integrated multicomponent systems from biological scaffolds using the power of rationally engineered DNA nanostructures.
Advances in one-dimensional wave mechanics. Towards a unified classical view
Energy Technology Data Exchange (ETDEWEB)
Cao, Zhuangqi [Shanghai Jiao Tong Univ., (China). Dept. of Physics and Astronomy; Yin, Cheng [Hohai Univ., Changzhou, Jiangsu (China). College of IoT Engineering
2014-06-01
Introduces a completely new concept of the scattered sub-waves via the Analytical Transfer Matrix (ATM) method. Develops a relatively simple method to accurately solve one-dimensional problems in quantum mechanics. Based on the analogy between the Quantum Mechanics and Electromagnetism, several interesting issues in quantum mechanics, such as tunneling, quantum reflection and scattering time are restudied. Advances in One-Dimensional Wave Mechanics provides a comprehensive description of the motion of microscopic particles in one-dimensional, arbitrary-shaped potentials based on the analogy between Quantum Mechanics and Electromagnetism. Utilizing a deeper understanding of the wave nature of matter, this book introduces the concept of the scattered sub-waves and a series of new analytical results using the Analytical Transfer Matrix (ATM) method. This work will be useful for graduate students majoring in physics, mainly in basic quantum theory, as well as for academic researchers exploring electromagnetism, particle physics, and wave mechanics and for experts in the field of optical waveguide and integrated optics.
Photoinduced charge-order melting dynamics in a one-dimensional interacting Holstein model
Hashimoto, Hiroshi; Ishihara, Sumio
2017-07-01
Transient quantum dynamics in an interacting fermion-phonon system are investigated with a focus on a charge order (CO) melting after a short optical-pulse irradiation and the roles of the quantum phonons in the transient dynamics. A spinless-fermion model in a one-dimensional chain coupled with local phonons is analyzed numerically. The infinite time-evolving block decimation algorithm is adopted as a reliable numerical method for one-dimensional quantum many-body systems. Numerical results for the photoinduced CO melting dynamics without phonons are well interpreted by the soliton picture for the CO domains. This interpretation is confirmed by numerical simulation of an artificial local excitation and the classical soliton model. In the case of large phonon frequencies corresponding to the antiadiabatic condition, CO melting is induced by propagations of the polaronic solitons with the renormalized soliton velocity. On the other hand, in the case of small phonon frequencies corresponding to the adiabatic condition, the first stage of the CO melting dynamics occurs due to the energy transfer from the fermionic to phononic systems, and the second stage is brought about by the soliton motions around the bottom of the soliton band. The analyses provide a standard reference for photoinduced CO melting dynamics in one-dimensional many-body quantum systems.
One-dimensional metallic wires at phase-engineered boundaries in two-dimensional materials
Gibertini, Marco; Marzari, Nicola
At the interfaces between systems with different electric polarization, free carriers appear in order to screen the resulting polarization charges associated with the resulting polar discontinuity. This mechanism is believed to be at the origin of the two-dimensional electron gas emerging at oxide interfaces and provides the basis for manifold exciting novel phenomena. Recently, it has been shown that similar processes take place also in two-dimensional materials, where one-dimensional wires of free carriers are induced at planar interfaces between materials with different in-plane polarization or at the edges of polar nanoribbons. Here we show by first-principles simulations that some two-dimensional polar materials can display a metastable non-polar phase, so that boundaries between the stable and metastable phases support a polar discontinuity and the resulting one-dimensional metallic wires. We provide several approaches to engineer such phase boundaries by locally inducing metastable phases in a single parent crystal. We finally show how this novel strategy to engineer polar discontinuities in two dimensions offers unprecedented opportunities to efficiently manipulate and reconfigure the emerging one-dimensional metallic wires or switch their conducting state.
Maximizing kinetic energy transfer in one-dimensional many-body collisions
Ricardo, Bernard; Lee, Paul
2015-03-01
The main problem discussed in this paper involves a simple one-dimensional two-body collision, in which the problem can be extended into a chain of one-dimensional many-body collisions. The result is quite interesting, as it provides us with a thorough mathematical understanding that will help in designing a chain system for maximum energy transfer for a range of collision types. In this paper, we will show that there is a way to improve the kinetic energy transfer between two masses, and the idea can be applied recursively. However, this method only works for a certain range of collision types, which is indicated by a range of coefficients of restitution. Although the concept of momentum, elastic and inelastic collision, as well as Newton’s laws, are taught in junior college physics, especially in Singapore schools, students in this level are not expected to be able to do this problem quantitatively, as it requires rigorous mathematics, including calculus. Nevertheless, this paper provides nice analytical steps that address some common misconceptions in students’ way of thinking about one-dimensional collisions.
Ramos, A; Talaia, P; Queirós de Melo, F J
2016-01-01
The main goal of this work was to develop an approached model to study dynamic behavior and prediction of the stress distribution in an in vitro Charnley cemented hip arthroplasty. An alternative version of the described pseudo-dynamic procedure is proposed by using the time integration Newmark algorithm. An internal restoring force vector is numerically calculated from the displacement, velocity, and acceleration vectors. A numerical model of hip replacement was developed to analyze the deformation of a dynamically stressed structure for all time steps. The experimental measurement of resulting internal forces generated in the structure (internal restoring force vector) is the second fundamental step of the pseudo-dynamic procedure. These data (as a feedback) are used by the time integration algorithm, which allows updating of the structure's shape for the next displacement, velocity, and acceleration vectors. In the field of Biomechanics, the potentialities of this method contribute to the determination of a dynamically equivalent in vitro stress field of a cemented hip prosthesis; implant fitted in patients with a normal mobility or practice sports. Consequences of the stress distribution in the implant zone that underwent cyclic fatigue loads were also discussed by using a finite element model. Application of this method in Biomechanics appears as a useful tool in the approximate stress field characterization of the peak stress state. Results show a peak value around two times the static situation, more for making possible the prediction of future damage and a programed clinical examination in patients using hip prosthesis.
Matrix product state calculations for one-dimensional quantum chains and quantum impurity models
Energy Technology Data Exchange (ETDEWEB)
Muender, Wolfgang
2011-09-28
This thesis contributes to the field of strongly correlated electron systems with studies in two distinct fields thereof: the specific nature of correlations between electrons in one dimension and quantum quenches in quantum impurity problems. In general, strongly correlated systems are characterized in that their physical behaviour needs to be described in terms of a many-body description, i.e. interactions correlate all particles in a complex way. The challenge is that the Hilbert space in a many-body theory is exponentially large in the number of particles. Thus, when no analytic solution is available - which is typically the case - it is necessary to find a way to somehow circumvent the problem of such huge Hilbert spaces. Therefore, the connection between the two studies comes from our numerical treatment: they are tackled by the density matrix renormalization group (DMRG) and the numerical renormalization group (NRG), respectively, both based on matrix product states. The first project presented in this thesis addresses the problem of numerically finding the dominant correlations in quantum lattice models in an unbiased way, i.e. without using prior knowledge of the model at hand. A useful concept for this task is the correlation density matrix (CDM) which contains all correlations between two clusters of lattice sites. We show how to extract from the CDM, a survey of the relative strengths of the system's correlations in different symmetry sectors as well as detailed information on the operators carrying long-range correlations and the spatial dependence of their correlation functions. We demonstrate this by a DMRG study of a one-dimensional spinless extended Hubbard model, while emphasizing that the proposed analysis of the CDM is not restricted to one dimension. The second project presented in this thesis is motivated by two phenomena under ongoing experimental and theoretical investigation in the context of quantum impurity models: optical absorption
Energy Technology Data Exchange (ETDEWEB)
Krishnan, Shutesh, E-mail: shutesh.k@onsemi.com [Department of Mechanical Engineering University of Malaya, 50603 Kuala Lumpur (Malaysia); ON Semiconductor Package Innovation and Development Center, 70450 Seremban (Malaysia); Haseeb, A.S.M.A.; Johan, Mohd Rafie [Department of Mechanical Engineering University of Malaya, 50603 Kuala Lumpur (Malaysia)
2014-02-15
Highlights: • One-dimensional CuO nanoflakes were synthesized by novel wire explosion technique. • A physical synthesis method capable of producing high aspect ratio (1:16) nanocrystals. • Most energy efficient and eco-friendly synthesis of low-dimensional transition metal oxide nanocrystals. -- Abstract: One-dimensional (1D) copper oxide (CuO) nanocrystals were synthesized using a novel wire explosion in de-ionized (DI) water without any chemical additives. Highly crystalline 1D CuO nanocrystals with 1:16 aspect ratio were successfully synthesized using this technique. The chemical nature and physical structure of the nanocrystals were controlled by simply modulating the exploding medium temperature. The results showed that nanocrystals produced at explosion temperatures 65 °C and 95 °C are pure CuO with optical band-gap energy of 2.38 eV. High Resolution Transmission Electron Microscope analysis (HRTEM) indicates that the CuO nanocrystals are with growth in [1{sup ¯}11] and [1 1 1] directions. The epitaxial crystal growth kinetics of the 1D nanostructure by aggregation was discussed. The incorporation of microstructural features like edge dislocations and porosity in the growth mechanism was examined. X-ray photoelectron spectroscopy (XPS) characterization indicates the formation of high purity CuO nanocrystals with valence state +2. This study provides an energy efficient and eco-friendly synthesis method of 1D transition metal oxide nanocrystals for electronic applications.
Directory of Open Access Journals (Sweden)
D. Naef
2006-01-01
Full Text Available This paper describes a one-dimensional finite element code for debris flows developed to model the flow within a steep channel and the stopping conditions on the fan. The code allows the systematic comparison of a wide variety of previously proposed one-phase flow resistance laws using the same finite element solution method. The one-dimensional depth-averaged equations of motion and the numerical model are explained. The model and implementation of the flow resistance relations was validated using published analytical results for the dam break case. Reasonable agreement for the front velocities and stopping location for a debris-flow event in the Kamikamihori torrent in Japan can be achieved with turbulent flow resistance relations including 'stop' terms which allow the flow to come to rest on a gently sloping surface. While it is possible to match the overall bulk flow behavior using relatively simple flow resistance relations, they must be calibrated. A sensitivity analysis showed that the shape of the upstream input hydrograph does not much affect the flow conditions in the lower part of the flow path, whereas the event volume is much more important.
Pseudo-periodic partitions of biological sequences.
Li, Lugang; Jin, Renchao; Kok, Poh-Lin; Wan, Honghui
2004-02-12
Algorithm development for finding typical patterns in sequences, especially multiple pseudo-repeats (pseudo-periodic regions), is at the core of many problems arising in biological sequence and structure analysis. In fact, one of the most significant features of biological sequences is their high quasi-repetitiveness. Variation in the quasi-repetitiveness of genomic and proteomic texts demonstrates the presence and density of different biologically important information. It is very important to develop sensitive automatic computational methods for the identification of pseudo-periodic regions of sequences through which we can infer, describe and understand biological properties, and seek precise molecular details of biological structures, dynamics, interactions and evolution. We develop a novel, powerful computational tool for partitioning a sequence to pseudo-periodic regions. The pseudo-periodic partition is defined as a partition, which intuitively has the minimal bias to some perfect-periodic partition of the sequence based on the evolutionary distance. We devise a quadratic time and space algorithm for detecting a pseudo-periodic partition for a given sequence, which actually corresponds to the shortest path in the main diagonal of the directed (acyclic) weighted graph constructed by the Smith-Waterman self-alignment of the sequence. We use several typical examples to demonstrate the utilization of our algorithm and software system in detecting functional or structural domains and regions of proteins. A big advantage of our software program is that there is a parameter, the granularity factor, associated with it and we can freely choose a biological sequence family as a training set to determine the best parameter. In general, we choose all repeats (including many pseudo-repeats) in the SWISS-PROT amino acid sequence database as a typical training set. We show that the granularity factor is 0.52 and the average agreement accuracy of pseudo-periodic partitions
Guyonvarch, Estelle; Ramin, Elham; Kulahci, Murat; Plósz, Benedek Gy
2015-10-15
The present study aims at using statistically designed computational fluid dynamics (CFD) simulations as numerical experiments for the identification of one-dimensional (1-D) advection-dispersion models - computationally light tools, used e.g., as sub-models in systems analysis. The objective is to develop a new 1-D framework, referred to as interpreted CFD (iCFD) models, in which statistical meta-models are used to calculate the pseudo-dispersion coefficient (D) as a function of design and flow boundary conditions. The method - presented in a straightforward and transparent way - is illustrated using the example of a circular secondary settling tank (SST). First, the significant design and flow factors are screened out by applying the statistical method of two-level fractional factorial design of experiments. Second, based on the number of significant factors identified through the factor screening study and system understanding, 50 different sets of design and flow conditions are selected using Latin Hypercube Sampling (LHS). The boundary condition sets are imposed on a 2-D axi-symmetrical CFD simulation model of the SST. In the framework, to degenerate the 2-D model structure, CFD model outputs are approximated by the 1-D model through the calibration of three different model structures for D. Correlation equations for the D parameter then are identified as a function of the selected design and flow boundary conditions (meta-models), and their accuracy is evaluated against D values estimated in each numerical experiment. The evaluation and validation of the iCFD model structure is carried out using scenario simulation results obtained with parameters sampled from the corners of the LHS experimental region. For the studied SST, additional iCFD model development was carried out in terms of (i) assessing different density current sub-models; (ii) implementation of a combined flocculation, hindered, transient and compression settling velocity function; and (iii
Directory of Open Access Journals (Sweden)
Reza Jalilian
2014-07-01
Full Text Available A Class of new methods based on a septic non-polynomial splinefunction for the numerical solution one-dimensional Bratu's problemare presented. The local truncation errors and the methods of order2th, 4th, 6th, 8th, 10th, and 12th, are obtained. The inverse ofsome band matrixes are obtained which are required in provingthe convergence analysis of the presented method. Associatedboundary formulas are developed. Convergence analysis of thesemethods is discussed. Numerical results are given to illustrate theefficiency of methods.
National Research Council Canada - National Science Library
Hu, Ming Jun; Lin, Bin; Yu, Shu Hong
2008-01-01
One-dimensional magnetic Ni-Co alloy microwires with different microstructures and differently shaped building blocks including spherical particles, multilayer stacked alloy plates, and alloy flowers...
A one-dimensional heat transfer model for parallel-plate thermoacoustic heat exchangers.
de Jong, J A; Wijnant, Y H; de Boer, A
2014-03-01
A one-dimensional (1D) laminar oscillating flow heat transfer model is derived and applied to parallel-plate thermoacoustic heat exchangers. The model can be used to estimate the heat transfer from the solid wall to the acoustic medium, which is required for the heat input/output of thermoacoustic systems. The model is implementable in existing (quasi-)1D thermoacoustic codes, such as DeltaEC. Examples of generated results show good agreement with literature results. The model allows for arbitrary wave phasing; however, it is shown that the wave phasing does not significantly influence the heat transfer.
Quasi-One-Dimensional Particle-in-Cell Simulation of Magnetic Nozzles
Ebersohn, Frans H.; Sheehan, J. P.; Gallimore, Alec D.; Shebalin, John V.
2015-01-01
A method for the quasi-one-dimensional simulation of magnetic nozzles is presented and simulations of a magnetic nozzle are performed. The effects of the density variation due to plasma expansion and the magnetic field forces on ion acceleration are investigated. Magnetic field forces acting on the electrons are found to be responsible for the formation of potential structures which accelerate ions. The effects of the plasma density variation alone are found to only weakly affect ion acceleration. Strongly diverging magnetic fields drive more rapid potential drops.
ORINC: a one-dimensional implicit approach to the inverse heat conduction problem. [PWR
Energy Technology Data Exchange (ETDEWEB)
Ott, L.J.; Hedrick, R.A.
1977-10-18
The report develops an implicit solution technique to determine both the transient surface temperature and the transient surface heat flux of electrically heated rods given the power input and an ''indicated'' internal temperature during a simulated loss-of-coolant accident. A digital computer program ORINC (ORNL Inverse Code) is developed which solves a one-dimensional, transient, lumped parameter, implicit formulation of the conduction equation at each bundle thermocouple position in the Thermal-Hydraulic Test Facility (THTF).
Ground-state properties and density response of quasi-one-dimensional electron systems
Agosti, Daniele; Pederiva, Francesco; Lipparini, Enrico; Takayanagi, Kazuo
1998-06-01
Ground-state properties of the quasi-one-dimensional electron gas in a quantum wire are calculated in the random-phase approximation (RPA), the ladder approximation, and the Singwi-Tosi-Land-Sjölander approximation. Numerical results are given for the exchange-correlation energy and the compressibility as a function of the electron density and the width of the wire. The dielectric response of the system has been calculated in the local field approximation and compared with the RPA result.
Jose, Jolly; Wanare, Harshawardhan
2012-02-01
We propose an optical sensor that allows site-selective detection of a refractive index change occurring due to any infiltration such as a bio-organism in a porous one-dimensional photonic crystal (PC). We use the electromagnetically induced transparency (EIT) to detect and locate the infiltration. With a localized change in the refractive index, the maximum of the peak EIT transmission shifts, which is determined by tuning the control field frequency. The strong dispersion and the narrowing of the absorption free response associated with EIT within the PC form the basis of such enhanced sensitivity.
Phase Transitions in One-Dimensional Truncated Bosonic Hubbard Model and Its Spin-1 Analog
Kashurnikov, V. A.; Krasavin, A.V.; Svistunov, B. V.
1997-01-01
We study one-dimensional truncated (no more than 2 particles on a site) bosonic Hubbard model in both repulsive and attractive regimes by exact diagonalization and exact worldline Monte Carlo simulation. In the commensurate case (one particle per site) we demonstrate that the point of Mott-insulator -- superfluid transition, $(U/t)_c=0.50\\pm 0.05$, is remarkably far from that of the full model. In the attractive region we observe the phase transition from one-particle superfluid to two-partic...
Optical Response of Polarons and Solitons in One-Dimensional Peierls--Hubbard Model
Maeshima, Nobuya; Moriya, Kosuke; Hino, Ken-ichi
2012-10-01
We investigate optical properties of polarons and solitons in one-dimensional (1D) Peierls--Hubbard model by using the density matrix renormalization group method combined with the adiabatic approximation for lattice distortion. Obtained numerical results demonstrate that there appear novel midgap peaks in optical response spectra of polarons and charged-solitons for large on-site Coulomb interaction U. The origins of these novel peaks are understood in terms of charge-transfer excitations within clusters for each states: a dimer in polarons and a pentamer in charged-solitons, both of which are located around the center of the relaxed lattice distortion.
Quantum criticality and the Tomonaga-Luttinger liquid in one-dimensional Bose gases
Yang, Bing; Chen, Yang-Yang; Zheng, Yong-Guang; Sun, Hui; Dai, Han-Ning; Guan, Xi-Wen; Yuan, Zhen-Sheng; Pan, Jian-Wei
2017-10-01
We experimentally investigate the quantum criticality and Tomonaga-Luttinger liquid (TLL) behavior within one-dimensional (1D) ultracold atomic gases. Based on the measured density profiles at different temperatures, the universal scaling laws of thermodynamic quantities are observed. The quantum critical regime and the relevant crossover temperatures are determined through the double-peak structure of the specific heat. In the TLL regime, we obtain the Luttinger parameter by probing sound propagation. Furthermore, a characteristic power-law behavior emerges in the measured momentum distributions of the 1D ultracold gas, confirming the existence of the TLL.
Li, Nianbei; Li, Baowen
2009-04-01
We derive the thermal conductivities of one-dimensional harmonic and anharmonic lattices with self-consistent heat baths from the single-mode relaxation time (SMRT) approximation. For harmonic lattice, we obtain the same result as previous works. However, our approach is heuristic and reveals phonon picture explicitly within the heat transport process. The results for harmonic and anharmonic lattices are compared with numerical calculations from Green-Kubo formula. The consistency between derivation and simulation strongly supports that effective (renormalized) phonons are energy carriers in anharmonic lattices although there exist some other excitations such as solitons and breathers.
Properties of density of modes in one dimensional magnetized plasma photonic crystals
Prasad, S.; Sharma, Y.; Shukla, S.; Singh, V.
2016-03-01
The electromagnetic density of modes in a finite one dimensional magnetized plasma photonic crystal is computed using Wigner time approach. Structural parameters are varied to observe its effect on the density of modes. It is found that cyclotron frequency, collision frequency, incident angle, dielectric constant of constituent material, and filling factor of plasma strongly influence the value of density of modes on the band gap edges and in the mid frequency. It is observed that the value of density of modes at the left edge of the band gap is always higher than those at the right edge and in the midpoint of the band gap.
Energy Technology Data Exchange (ETDEWEB)
Gonchar, K. A., E-mail: k.a.gonchar@gmail.com [Moscow State University, Physics Faculty (Russian Federation); Musabek, G. K.; Taurbayev, T. I. [Al Farabi Kazakh National University, Physics Department (Kazakhstan); Timoshenko, V. Yu. [Moscow State University, Physics Faculty (Russian Federation)
2011-05-15
In porous-silicon-based multilayered structures that exhibit the properties of one-dimensional photonic crystals, an increase in the photoluminescence and Raman scattering intensities is observed upon optical excitation at the wavelength 1.064 {mu}m. When the excitation wavelength falls within the edge of the photonic band gap of the structures, a multiple increase (by a factor larger than 400) in the efficiency of Raman scattering is detected. The effect is attributed to partial localization of excitation light and, correspondingly, to the much longer time of interaction of light with the material in the structures.
Superluminal pulse propagation through one-dimensional photonic crystals with a dispersive defect.
Liu, Nian-Hua; Zhu, Shi-Yao; Chen, Hong; Wu, Xiang
2002-04-01
The propagation of a pulse through one-dimensional photonic crystals that contain a dispersive and absorptive defect layer doped with two-level atoms is discussed. The dynamical evolution of the pulse inside the photonic crystal is presented. Superluminal negative group velocity (the peak appears at the exit end before it reaches the input end) is discovered. Although the group velocity is larger than c and even negative, the velocity of energy propagation never exceeds the vacuum light speed. The appearance of the superluminal advance or subluminal delay of the pulse peak inside the photonic crystal or at the exit end is due to the wave interference from Bragg reflections.
Modeling of inelastic transport in one-dimensional metallic atomic wires
DEFF Research Database (Denmark)
Frederiksen, Thomas; Brandbyge, Mads; Lorente, N
2004-01-01
Atomic-size conductors represent the ultimate limit of miniaturization, and understanding their properties is an important problem in the fields of nanoelectronics and molecular electronics. Quantum effects become important which leads to a physical behavior fundamentally different from macroscopic...... devices. A full description of the transport properties of atomic-size conductors therefore requires a quantum mechanical treatment of both the electronic and mechanical degrees of freedom. In this paper, we study a one-dimensional tight-binding model of the conducting electrons combined with a balls...
One-Dimensional Contact Mode Interdigitated Center of Pressure Sensor (CMIPS)
Xu, Tian-Bing; Kang, Jinho; Park, Cheol; Harrison, Joycelyn S.; Guerreiro, Nelson M.; Hubbard, James E.
2009-01-01
A one dimensional contact mode interdigitated center of pressure sensor (CMIPS) has been developed. The experimental study demonstrated that the CMIPS has the capability to measure the overall pressure as well as the center of pressure in one dimension, simultaneously. A theoretical model for the CMIPS is established here based on the equivalent circuit of the configuration of the CMIPS as well as the material properties of the sensor. The experimental results match well with theoretical modeling predictions. A system mapped with two or more pieces of the CMIPS can be used to obtain information from the pressure distribution in multi-dimensions.
Bragheri, F; Faccio, D; Romagnoli, M; Krauss, T; Roberts, J
2004-01-01
We study the problem of the tolerance to fabrication errors in one-dimensional photonic crystal wavelength converters. In particular we consider the case of wavelength conversion obtained via quasiphase matching (QPM) based on a periodic amplitude modulation of the fundamental wave (Bloch-mode-QPM). Both numerical simulations of a waveguide-based structure and experimental results in an AlGaAs thin-film multilayer show that the proposed QPM mechanism is extremely tolerant to both systematic and random errors in the periodicity and duty cycle of the grating.
Noise-amplitude dependence of the invariant density for noisy, fully chaotic one-dimensional maps
Seshadri, S.; Balakrishnan, V.; Lakshmibala, S.
1999-07-01
We present some analytic, nonperturbative results for the invariant density ρ(x) for noisy one-dimensional maps at fully developed chaos. Under periodic boundary conditions, the Fourier expansion method is used to show precisely how noise makes ρ(x) absolutely continuous and smooths it out. Simple solvable models are used to illustrate the explicit dependence of ρ(x) on the amplitude η of the noise distribution, all the way from the case of zero noise (η-->0) to the completely noise-dominated limit (η=1).
Switching synchronization in one-dimensional memristive networks: An exact solution
Slipko, V. A.; Pershin, Y. V.
2017-12-01
We study a switching synchronization phenomenon taking place in one-dimensional memristive networks when the memristors switch from the high- to low-resistance state. It is assumed that the distributions of threshold voltages and switching rates of memristors are arbitrary. Using the Laplace transform, a set of nonlinear equations describing the memristors dynamics is solved exactly, without any approximations. The time dependencies of memristances are found, and it is shown that the voltage falls across memristors are proportional to their threshold voltages. A compact expression for the network switching time is derived.
Yao, Zhongqi; Luo, Jie; Lai, Yun
2017-12-11
In this work, we propose that one-dimensional ultratransparent dielectric photonic crystals with wide-angle impedance matching and shifted elliptical equal frequency contours are promising candidate materials for illusion optics. The shift of the equal frequency contour does not affect the refractive behaviors, but enables a new degree of freedom in phase modulation. With such ultratransparent photonic crystals, we demonstrate some applications in illusion optics, including creating illusions of a different-sized scatterer and a shifted source with opposite phase. Such ultratransparent dielectric photonic crystals may establish a feasible platform for illusion optics devices at optical frequencies.
Entanglement in the quantum one-dimensional integer spin S Heisenberg antiferromagnet
Lima, L. S.
2017-10-01
We use the modified spin wave theory of Takahashi to study the entanglement entropy in the quantum one-dimensional integer spin Heisenberg antiferromagnet. We calculate the entanglement entropy of this spin system that is well known to be a quantum wire, in the classical limit (N → ∞). We obtain a decreasing the entanglement entropy with the temperature and we obtain none change in the entanglement in the point Δ = 1 at T = 0 where the system presents a quantum phase transition from a gapless phase in the spectrum Δ < 1 to a gapped phase Δ ≥ 1.
A Novel One-Dimensional Electronic State at IrTe2 Surface
Ootsuki, Daiki; Ishii, Hiroyuki; Kudo, Kazutaka; Nohara, Minoru; Takahashi, Masaya; Horio, Masafumi; Fujimori, Atsushi; Yoshida, Teppei; Arita, Masashi; Anzai, Hiroaki; Namatame, Hirofumi; Taniguchi, Masaki; Saini, Naurang L.; Mizokawa, Takashi
2017-12-01
Highly one-dimensional (1D) Fermi sheets are realized at the surface of a layered Ir telluride IrTe2 which exhibits a stripe-type charge and orbital order below ˜280 K. The 1D Fermi sheets appear in the low temperature range where the stripe order is well established. The 1D Fermi sheets are truncated by the bulk Fermi surfaces, and the spectral weight suppression at the Fermi level deviates from the typical Tomonaga-Luttinger behavior. The 1D band runs along the stripe and is accompanied by several branches which can be derived from the quantization in the perpendicular direction.
Universal spin-polarization fluctuations in one-dimensional wires with magnetic impurities
DEFF Research Database (Denmark)
Mortensen, Asger; Egues, J.C.
2002-01-01
We study conductance and spin-polarization fluctuations in one-dimensional wires with spin-5/2 magnetic impurities (Mn). Our tight-binding Green function approach goes beyond the mean field thus including s-d exchange-induced spin-flip scattering. In a certain parameter range, we find that spin......-flip suppresses conductance fluctuations while enhancing spin-polarization fluctuations. More importantly, spin-polarization fluctuations attain a universal value 1/3 for large enough spin-flip strengths. This intrinsic spin-polarization fluctuation may pose a severe limiting factor to the realization of steady...
One-Dimensional Stationary Mean-Field Games with Local Coupling
Gomes, Diogo A.
2017-05-25
A standard assumption in mean-field game (MFG) theory is that the coupling between the Hamilton–Jacobi equation and the transport equation is monotonically non-decreasing in the density of the population. In many cases, this assumption implies the existence and uniqueness of solutions. Here, we drop that assumption and construct explicit solutions for one-dimensional MFGs. These solutions exhibit phenomena not present in monotonically increasing MFGs: low-regularity, non-uniqueness, and the formation of regions with no agents.
Abrupt Convergence for Stochastic Small Perturbations of One Dimensional Dynamical Systems
Barrera, G.; Jara, M.
2016-04-01
We study the cut-off phenomenon for a family of stochastic small perturbations of a one dimensional dynamical system. We will focus in a semiflow of a deterministic differential equation which is perturbed by adding to the dynamics a white noise of small variance. Under suitable hypothesis on the potential we will prove that the family of perturbed stochastic differential equations present a profile cut-off phenomenon with respect to the total variation distance. We also prove a local cut-off phenomenon in a neighborhood of the local minima (metastable states) of multi-well potential.
Study of the one-dimensional Holstein model using the augmented space approach
Energy Technology Data Exchange (ETDEWEB)
Chakrabarti, Atisdipankar [R.K.M.V.C. College, Rahara, 24 Parganas (North), West Bengal (India); Chakraborty, Monodeep [S.N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake, Kolkata 700098 (India); Mookerjee, A. [S.N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake, Kolkata 700098 (India)]. E-mail: abhijit@bose.res.in
2007-01-15
A new formalism using the ideas of the augmented space recursion (introduced by one of us) has been proposed to study the ground state properties of ordered and disordered one-dimensional Holstein model. For ordered case our method works equally well in all parametric regime and matches with the existing exact diagonalization and DMRG results. On the other hand, the quenched substitutionally disordered model works in low and intermediate regime of electron phonon coupling. Effect of phononic and substitutional disorder is treated on equal footing.
Yetirmishli, G. C.; Kazimova, S. E.; Kazimov, I. E.
2011-09-01
We present the method for determining the velocity model of the Earth's crust and the parameters of earthquakes in the Middle Kura Depression from the data of network telemetry in Azerbaijan. Application of this method allowed us to recalculate the main parameters of the hypocenters of the earthquake, to compute the corrections to the arrival times of P and S waves at the observation station, and to significantly improve the accuracy in determining the coordinates of the earthquakes. The model was constructed using the VELEST program, which calculates one-dimensional minimal velocity models from the travel times of seismic waves.
A One-Dimensional Numerical Model to Study the Effects of Cumulus Clouds on the Environment,
the environment . The model combines a one-dimensional Lagrangian cumulus cloud model with the basic physical processes of cyclonic scale lifting, surface eddy mixing, cloud induced environmental subsidence, sub-cloud hydrometeor water evaporation and horizontal diffusion of the dissipating cloud. Included in this documentation are a detailed model description, derivation of the model equations, a basic flow diagram, a list of program mnemonics, a description of the input data format and a model listing and output from the National Center for Atmospheric Research’s
Macroscopic traveling packet and soliton states of quasi-one-dimensional flocks.
Guttenberg, Nicholas; Toner, John; Tu, Yuhai
2014-05-01
Using a continuum model for inhomogeneous flocks, we show that a finite but arbitrarily large moving "packet" of active particles (e.g., moving creatures) can form in a background of a lower density disordered phase of these particles, like a liquid drop surrounded by vapor. The "vapor density" of the disordered background can be made arbitrarily low. We find three basic types of quasi-one-dimensional states: "longitudinal", "transverse", and "oblique" states, with their internal velocity fields, respectively, parallel, perpendicular, and oblique to the interface. The transitions between these states are also studied.
Decoherence dynamics in interferometry with one-dimensional bose-einstein condensates
DEFF Research Database (Denmark)
Schumm, Thorsten; Hofferberth, Sebastian; Schmiedmayer, Jörg
2007-01-01
We perform interferometry with one-dimensional Bose-Einstein condensates in a double well potential. Using dressed adiabatic potentials on an atomchip, we dynamically split BECs, imposing a macroscopic coherence on the system. Fluctuations of the order parameter are revealed as local shifts...... in the interference pattern and allow a quantization of the decoherence process with time. For the uncoupled system we ultimately recover individual phase fluctuating condensates, whereas finite tunnel coupling counteracts the decoherence and leads to an equilibrium characterized by a finite coherence length...
Controlled excitation of resonance self-oscillations in one-dimensional distributed systems
Izrailovich, M. Ya.
2004-03-01
On the basis of the method of equivalent linearization combined with the method of moments, laws of self-oscillation excitation are obtained that provide the modes with maximum intensity of resonance (or quasi-resonance) oscillations in one-dimensional systems with distributed parameters. A restriction of a general type is imposed on the law of excitation. In the particular case of an integral quadratic restriction, the law of excitation leads to the generation of purely harmonic self-oscillations. The use of an extended (multiplicatively stabilizing) control provides the uniqueness and stability of the quasi-optimal mode of self-oscillation.
Study on the propagation mechanism of evanescent waves in one-dimensional periodic photonic crystal
Energy Technology Data Exchange (ETDEWEB)
Chen, Ying, E-mail: chenying@ysu.edu.cn [Hebei Province Key Laboratory of Test/Measurement Technology and Instrument, School of Electrical Engineering, Yanshan University, Qinhuangdao 066004 (China); Shi, Jia; Liu, Teng; Dong, Jing [Hebei Province Key Laboratory of Test/Measurement Technology and Instrument, School of Electrical Engineering, Yanshan University, Qinhuangdao 066004 (China); Zhu, Qiguang; Chen, Weidong [Key Laboratory of Special Fiber and Fiber Sensor of Hebei Province, School of Information Science and Engineering, Yanshan University, Qinhuangdao 066004 (China)
2015-10-02
Based on the evanescent waves theory, the formation condition and propagation mechanism of evanescent waves in one-dimensional periodic photonic crystal are studied. When the incident light travels through the periodic photonic crystal at a certain angle, the optical resonance will occur in the optically denser medium, and a unique photonic local feature will occur in photonic bandgap. Furthermore, the influences on transmission performance by the photonic crystal parameters are discussed respectively. The simulation results show that the structure mentioned above can achieve the performance of high transmission and high Q value, which can provide theoretical references for photonic crystal multi-channel filters.
Non-equilibrium coherence dynamics in one-dimensional Bose gases
DEFF Research Database (Denmark)
Hofferberth, S.; Lesanovsky, Igor; Fischer, B.
2007-01-01
Low-dimensional systems provide beautiful examples of many-body quantum physics. For one-dimensional (1D) systems, the Luttinger liquid approach provides insight into universal properties. Much is known of the equilibrium state, both in the weakly and strongly interacting regimes. However...... evolution of the coherence is revealed through local phase shifts of the subsequently observed interference patterns. Completely isolated 1D Bose gases are observed to exhibit universal sub-exponential coherence decay, in excellent agreement with recent predictions. For two coupled 1D Bose gases...
A GENETIC ALGORITHM FOR THE ONE-DIMENSIONAL CUTTING STOCK PROBLEM WITH SETUPS
Directory of Open Access Journals (Sweden)
Silvio Alexandre de Araujo
2014-05-01
Full Text Available This paper investigates the one-dimensional cutting stock problem considering two conflicting objective functions: minimization of both the number of objects and the number of different cutting patterns used. A new heuristic method based on the concepts of genetic algorithms is proposed to solve the problem. This heuristic is empirically analyzed by solving randomly generated instances and also practical instances from a chemical-fiber company. The computational results show that the method is efficient and obtains positive results when compared to other methods from the literature.
Finite-temperature treatment of ultracold atoms in a one-dimensional optical lattice
Wild, B. G.; Blakie, P. B.; Hutchinson, D. A. W.
2006-02-01
We consider the effects of temperature upon the superfluid phase of ultracold, weakly interacting bosons in a one-dimensional optical lattice. We use a finite-temperature treatment of the Bose-Hubbard model based upon the Hartree-Fock-Bogoliubov formalism, considering both a translationally invariant lattice and one with additional harmonic confinement. In both cases we observe an upward shift in the critical temperature for Bose condensation. For the case with additional harmonic confinement, this is in contrast with results for the uniform gas.
Entanglement growth and simulation efficiency in one-dimensional quantum lattice systems
Perales, Álvaro; Vidal, Guifré
2008-10-01
We study the evolution of one-dimensional quantum lattice systems when the ground state is perturbed by altering one site in the middle of the chain. For a large class of models, we observe a similar pattern of entanglement growth during the evolution, characterized by a moderate increase of significant Schmidt coefficients in all relevant bipartite decompositions of the state. As a result, the evolution can be accurately described by a matrix product state and efficiently simulated using the time-evolving block decimation algorithm.
Directory of Open Access Journals (Sweden)
Ryotaro Ozaki
2015-09-01
Full Text Available Polarization characteristics of defect mode peaks in a one-dimensional (1D photonic crystal (PC with a nematic liquid crystal (NLC defect layer have been investigated. Two different polarized defect modes are observed in a stop band. One group of defect modes is polarized along the long molecular axis of the NLC, whereas another group is polarized along its short axis. Polarizations of the defect modes can be tuned by field-induced in-plane reorientation of the NLC in the defect layer. The polarization properties of the 1D PC with the NLC defect layer is also investigated by the finite difference time domain (FDTD simulation.
Fourier's law on a one-dimensional optical random lattice
Energy Technology Data Exchange (ETDEWEB)
Platini, T [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Harris, R J [School of Mathematical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS (United Kingdom); Karevski, D [Institut Jean Lamour, Departement Physique de la Matiere et des Materiaux, Groupe de Physique Statistique, Nancy-Universite CNRS, BP 70239, F-54506 Vandoeuvre les Nancy Cedex (France)
2010-04-02
We study the transport properties of a one-dimensional hard-core bosonic lattice gas coupled to two particle reservoirs at different chemical potentials which generate a current flow through the system. In particular, the influence of random fluctuations of the underlying lattice on the stationary-state properties is investigated. We show analytically that the steady-state density presents a linear profile. The local steady-state current obeys the Fourier law j = -{kappa}({tau}){nabla}n where {tau} is a typical timescale of the lattice fluctuations and {nabla}n is the density gradient imposed by the reservoirs.
Relaxation and thermalization dynamics in the one-dimensional Bose-Hubbard-model
Heidrich-Meisner, Fabian; Sorg, Stefan; Pollet, Lode; Vidmar, Lev
2014-05-01
Motivated by experiments recently carried out with ultracold atomic gases, we study the relaxation and thermalization dynamics of several observables in the one-dimensional Bose-Hubbard-model with integer filling after a global interaction quantum quench. Using exact diagonalization, we analyze the distribution of the diagonal matrix elements and the energy distribution of initial states in the framework of the eigenstate thermalization hypothesis, discussing its applicability in different regimes of U/J. We observe that time-averages of typical observables are well described by standard statistical ensembles. We acknowledge financial support through DFG FOR 801 and 1807.
Triazole-based one-dimensional spin-crossover coordination polymers.
Roubeau, Olivier
2012-11-26
One-dimensional coordination Fe(II) polymers constructed through triple N(1),N(2)-1,2,4-triazole bridges form a unique class of spin-crossover materials, the synthetic versatility of which allows tuning the spin-crossover properties, the design of gels, films, liquid crystals, and nanoparticles and single-particle addressing. This Minireview provides the first complete overview of these very attractive switchable materials and their most recent developments. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
The Optical Bloch oscillation in chirped one-dimensional superconducting photonic crystal
Zhang, Zhengren; Long, Yang; Zhang, Liwei; Yin, Pengfei; Xue, Chunhua
2017-09-01
We exploit theoretically the propagation properties of electromagnetic waves in nanoscale one-dimensional superconducting photonic crystal. The Wannier Stark ladders can be formed in the photonic crystal by varying the thickness of the dielectric layers linearly across the structure. The dynamics behavior of a Gaussian pulse transmitting through the structure is simulated theoretically. We find that photons undergo Bloch oscillations inside tilted photonic bands and the Bloch oscillations are sensitive to the change of temperature in the range of 3-8 K. It is demonstrated that our structure is possible to realize tunable optical Bloch oscillations by controlling the temperature of superconducting material.
One-dimensional dynamics for travelling fronts in coupled map lattices
Carretero-González, R; Vivaldi, F
1999-01-01
Multistable coupled map lattices typically support travelling fronts, separating two adjacent stable phases. We show how the existence of an invariant function describing the front profile, allows a reduction of the infinitely-dimensional dynamics to a one-dimensional circle homeomorphism, whose rotation number gives the propagation velocity. The mode-locking of the velocity with respect to the system parameters then typically follows. We study the behaviour of fronts near the boundary of parametric stability, and we explain how the mode-locking tends to disappear as we approach the continuum limit of an infinite density of sites.
Quasi-One-Dimensional Electronic States Inside and Outside Helium-Plated Carbon Nanotubes
Motta, M.; Galli, D. E.; Liebrecht, M.; Del Maestro, A.; Cole, M. W.
2016-10-01
About one-half a century ago, it was realized that electrons experience a repulsive barrier when approaching the surface of condensed phases of helium, hydrogen, and neon. This led to the proposal and subsequent observation of image-potential surface-bound electronic states, which exhibit intriguing quasi-two-dimensional behavior. In the present work, we report similar quasi-one-dimensional electronic states by exploring single-wall carbon nanotubes coated both inside and outside by thin helium films. Electrons near such structures are localized in the radial direction, but free to move along the nanotube axis. The many-body aspects of the system are discussed qualitatively.
Gas Sensors Based on Semiconducting Metal Oxide One-Dimensional Nanostructures
Directory of Open Access Journals (Sweden)
Jin Huang
2009-12-01
Full Text Available This article provides a comprehensive review of recent (2008 and 2009 progress in gas sensors based on semiconducting metal oxide one-dimensional (1D nanostructures. During last few years, gas sensors based on semiconducting oxide 1D nanostructures have been widely investigated. Additionally, modified or doped oxide nanowires/nanobelts have also been synthesized and used for gas sensor applications. Moreover, novel device structures such as electronic noses and low power consumption self-heated gas sensors have been invented and their gas sensing performance has also been evaluated. Finally, we also point out some challenges for future investigation and practical application.
Topological edge state with zero Hall conductivity in quasi-one dimensional system
Directory of Open Access Journals (Sweden)
Xiao-Shan Ye
2016-09-01
Full Text Available We explore the structure of the energy spectra of quasi-one dimensional (Q1D system subjected to spin-density-wave SDW states. The structure of the energy spectra opens energy gaps with Zeeman field. Theses gaps result in plateaus for the Quantum Hall conductivity which is associated with edge states. Different from the SSH Hofstadter model, here we show that there are a doublet of edge states contribution to zero Hall conductivity. These edge states are allowed for magnetic control of spin currents. The topological effects predicted here could be tested directly in organic conductors system.
One dimensional two-body collisions experiment based on LabVIEW interface with Arduino
Saphet, Parinya; Tong-on, Anusorn; Thepnurat, Meechai
2017-09-01
The purpose of this work is to build a physics lab apparatus that is modern, low-cost and simple. In one dimensional two-body collisions experiment, we used the Arduino UNO R3 as a data acquisition system which was controlled by LabVIEW program. The photogate sensors were designed using LED and LDR to measure position as a function of the time. Aluminium frame houseware and blower were used for the air track system. In both totally inelastic and elastic collision experiments, the results of momentum and energy conservation are in good agreement with the theoretical calculations.
Harada, Hiromitsu; Mouchet, Amaury; Shudo, Akira
2017-10-01
The topology of complex classical paths is investigated to discuss quantum tunnelling splittings in one-dimensional systems. Here the Hamiltonian is assumed to be given as polynomial functions, so the fundamental group for the Riemann surface provides complete information on the topology of complex paths, which allows us to enumerate all the possible candidates contributing to the semiclassical sum formula for tunnelling splittings. This naturally leads to action relations among classically disjoined regions, revealing entirely non-local nature in the quantization condition. The importance of the proper treatment of Stokes phenomena is also discussed in Hamiltonians in the normal form.
Transport diffusion in one dimensional molecular systems: Power law and validity of Fick’s law
Directory of Open Access Journals (Sweden)
Zhi-cheng Xu
2015-10-01
Full Text Available The transport diffusion in one-dimensional molecular systems is investigated through non-equilibrium molecular dynamics and Monte Carlo methods. We have proposed the power law relationship of the transport diffusion coefficient with the temperature, the mass and the transport length, D* ∝ T*m*−1L*β, where β equals to 0.8 for small systems and zero for large systems. It is found that Fick’s law is valid in long transport length but invalid in short transport length. Our results can provide a new perspective for understanding the microscopic mechanism of the molecular transport phenomena in low-dimensional systems.
Directed and undirected multiurn models in a one-dimensional ring
Nagler, Jan
2005-11-01
The flea model by Ehrenfest describes the jumps of a fixed number of fleas between two dogs. In each time step a randomly selected flea jumps on the other dog. We study directed and undirected multiurn models in a one-dimensional ring. The introduced models represent generalizations of three recently proposed multiurn models which themselves are generalizations of Ehrenfest’s model. The models are solved analytically. For the directed case we find oscillations of the average number of balls or fleas in a certain urn before the system reaches its equilibrium state. The discussed models may serve as basic models of dynamics of granular media in connected periodic compartment systems.
Extended one-dimensional method for coherent synchrotron radiation including shielding
Directory of Open Access Journals (Sweden)
David Sagan
2009-04-01
Full Text Available Coherent synchrotron radiation can severely limit the performance of accelerators designed for high brightness and short bunch length. Examples include light sources based on energy recovery LINAC or free-electron lasers, and bunch compressors for linear colliders. In order to better simulate coherent synchrotron radiation, a one-dimensional formalism due to Saldin, Schneidmiller, and Yurkov has been implemented in the general beam dynamics code Bmad. Wide vacuum chambers are simulated by means of vertical image charges. Results from Bmad are here compared to analytical approximations, to numerical solutions of the Maxwell equations, and to the simulation code elegant and the code of Agoh and Yokoya.
Formation of higher-band dark gap solitons in one dimensional waveguide arrays.
Dong, Rong; Rüter, Christian E; Song, Daohong; Xu, Jingjun; Kip, Detlef
2010-12-20
We experimentally observe the formation of spatial dark gap solitons in higher bands in one-dimensional waveguide arrays possessing a saturable defocusing nonlinearity. By using the prism-coupler scheme, pure Floquet-Bloch modes of higher bands are excited and dark gap solitons are formed due to the counteraction of normal diffraction and the defocusing nature of the photovoltaic nonlinearity. The modulation of refractive index induced by the soliton formation is demonstrated by the guidance of a low-power probe beam in the waveguide array sample. Additionally, the phase structure of dark solitons formed in the second band is discussed.
Encounter distribution of two random walkers on a finite one-dimensional interval
Energy Technology Data Exchange (ETDEWEB)
Tejedor, Vincent; Schad, Michaela; Metzler, Ralf [Physics Department, Technical University of Munich, James Franck Strasse, 85747 Garching (Germany); Benichou, Olivier; Voituriez, Raphael, E-mail: metz@ph.tum.de [Laboratoire de Physique Theorique de la Matiere Condensee (UMR 7600), Universite Pierre et Marie Curie, 4 Place Jussieu, 75255 Paris Cedex (France)
2011-09-30
We analyse the first-passage properties of two random walkers confined to a finite one-dimensional domain. For the case of absorbing boundaries at the endpoints of the interval, we derive the probability that the two particles meet before either one of them becomes absorbed at one of the boundaries. For the case of reflecting boundaries, we obtain the mean first encounter time of the two particles. Our approach leads to closed-form expressions that are more easily tractable than a previously derived solution in terms of the Weierstrass' elliptic function. (paper)
Analytical evaluation of thermal conductance and heat capacities of one-dimensional material systems
Energy Technology Data Exchange (ETDEWEB)
Saygi, Salih [Department of Physics, Gaziosmanpasa University, Tokat, 60200 Turkey (Turkey)
2014-02-15
We theoretically predict some thermal properties versus temperature dependence of one dimensional (1D) material nanowire systems. A known method is used to provide an efficient and reliable analytical procedure for wide temperature range. Predicted formulas are expressed in terms of Bloch-Grüneisen functions and Debye functions. Computing results has proved that the expressions are in excellent agreement with the results reported in the literature even if it is in very low dimension limits of nanowire systems. Therefore the calculation method is a fully predictive approach to calculate thermal conductivity and heat capacities of nanowire material systems.
Simple one-dimensional quantum-mechanical model for a particle attached to a surface
Energy Technology Data Exchange (ETDEWEB)
Fernandez, Francisco M, E-mail: fernande@quimica.unlp.edu.a [INIFTA (UNLP, CCT La Plata-CONICET), Division Quimica Teorica, Blvd 113 S/N, Sucursal 4, Casilla de Correo 16, 1900 La Plata (Argentina)
2010-07-15
We present a simple one-dimensional quantum-mechanical model for a particle attached to a surface. It leads to the Schroedinger equation for a harmonic oscillator bounded on one side that we solve in terms of Weber functions and discuss the behaviour of the eigenvalues and eigenfunctions. We derive the virial theorem and other exact relationships as well as the asymptotic behaviour of the eigenvalues. We calculate the zero-point energy for model parameters corresponding to H adsorbed on Pd(1 0 0). The model is suitable for an advanced undergraduate or graduate course on quantum mechanics.
One-Dimensional Quantum Transport Affected by a Background Medium: Fluctuations versus Correlations
Ejima, S.; Fehske, H.
2009-01-01
We analyze the spectral properties of a very general two-channel fermion-boson transport model in the insulating and metallic regimes, and the signatures of the metal-insulator quantum phase transition in between. To this end we determine the single particle spectral function related to angle-resolved photoemission spectroscopy, the momentum distribution function, the Drude weight and the optical response by means of a dynamical (pseudo-site) density-matrix renormalization group technique for...
Santos, Lea; Rigol, Marcos
2010-03-01
By means of exact diagonalization, we study level statistics and the structure of the eigenvectors of one-dimensional gapless bosonic and fermionic systems across the transition from integrability to quantum chaos. These systems are integrable in the presence of only nearest-neighbor terms, whereas the addition of next-nearest neighbor hopping and interaction may lead to the onset of chaos. We show that the strength of the next-nearest neighbor terms required to observe clear signatures of nonintegrability is inversely proportional to the system size. The transition to chaos is also seen to depend on particle statistics, bosons responding first to the integrability breaking terms. In addition, we discuss the use of delocalization measures as main indicators for the crossover from integrability to chaos. The analysis and findings described in this work footnotetextL. F. Santos and M. Rigol, arXiv:0910.2985 are intimately reflected by studies of thermalization.
Elshorbagy, Mahmoud H.; Alda, Javier
2017-01-01
Ultrathin amorphous silicon hydrogenated (aSi-H) solar cells grown on a one-dimensional (1-D) dielectric subwavelength gratings improve the short circuit current by a factor of more than 51% when compared with conventional, flat ultrathin aSi-H devices. This improvement is possible due to several mechanisms. In addition the increase in exposed area caused by the nanostructured surface, a reliable computational electromagnetic evaluation of the interaction of the solar spectrum with the cell structure demonstrates that absorption at the active layer is enhanced and also reflectivity is decreased. In addition, the absorbed power at the nonactive layers is larger, helping to increase the temperature and mitigate the Staebler-Wronski effect. The detailed analysis of the power flux inside the structure has also shown that funneling and guiding mechanism are at play, increasing the optical path within the active layer that produces a better performance of the cell.
Song, Yidan; Yu, Lili; Gao, Yuanrui; Shi, Changdong; Cheng, Meiling; Wang, Xianmei; Liu, Hong-Jiang; Liu, Qi
2017-10-02
A zinc-based one-dimensional (1D) coordination polymer ([Zn(H2mpca)2(tfbdc)(H2O)], Zn-ODCP) has been synthesized and characterized by spectroscopic and physicochemical methods, single-crystal X-ray diffraction, and thermogravimetric analysis (H2mpca = 3-methyl-1H-pyrazole-4-carboxylic acid; H2tfbdc = 2,3,5,6-tetrafluoroterephthalic acid). Zn-ODCP shows blue luminescence in the solid state. When Zn-ODCP acts as an anode material for lithium ion batteries, it exhibits a good cyclic stability and a higher reversible capacity of 300 mAh g-1 at 50 mA g-1 after 50 cycles. The higher capacity may be mainly ascribed to the metal ion and ligand all taking part in lithium storage. Searching for electrode materials of lithium ion batteries from 1D metal coordination polymers is a new route.
Quantized impedance dealing with the damping behavior of the one-dimensional oscillator
Directory of Open Access Journals (Sweden)
Jinghao Zhu
2015-11-01
Full Text Available A quantized impedance is proposed to theoretically establish the relationship between the atomic eigenfrequency and the intrinsic frequency of the one-dimensional oscillator in this paper. The classical oscillator is modified by the idea that the electron transition is treated as a charge-discharge process of a suggested capacitor with the capacitive energy equal to the energy level difference of the jumping electron. The quantized capacitance of the impedance interacting with the jumping electron can lead the resonant frequency of the oscillator to the same as the atomic eigenfrequency. The quantized resistance reflects that the damping coefficient of the oscillator is the mean collision frequency of the transition electron. In addition, the first and third order electric susceptibilities based on the oscillator are accordingly quantized. Our simulation of the hydrogen atom emission spectrum based on the proposed method agrees well with the experimental one. Our results exhibits that the one-dimensional oscillator with the quantized impedance may become useful in the estimations of the refractive index and one- or multi-photon absorption coefficients of some nonmagnetic media composed of hydrogen-like atoms.
Electronic structure and transport properties of quasi-one-dimensional carbon nanomaterials
Wu, Y. N.; Cheng, P.; Wu, M. J.; Zhu, H.; Xiang, Q.; Ni, J.
2017-09-01
Based on the density functional theory combined with the nonequilibrium Green's function, the influence of the wrinkle on the electronic structures and transport properties of quasi-one-dimensional carbon nanomaterials have been investigated, in which the wrinkled armchair graphene nanoribbons (wAGNRs) and the composite of AGNRs and single walled carbon nanotubes (SWCNTs) were considered with different connection of ripples. The wrinkle adjusts the electronic structures and transport properties of AGNRs. With the change of the strain, the wAGNRs for three width families reveal different electrical behavior. The band gap of AGNR(6) increases in the presence of the wrinkle, which is opposite to that of AGNR(5) and AGNR(7). The transport of AGNRs with the widths 6 or 7 has been modified by the wrinkle, especially by the number of isolated ripples, but it is insensitive to the strain. The nanojunctions constructed by AGNRs and SWCNTs can form the quantum wells, and some specific states are confined in wAGNRs. Although these nanojunctions exhibit the metallic, they have poor conductance due to the wrinkle. The filling of C20 into SWCNT has less influence on the electronic structure and transport of the junctions. The width and connection type of ripples have greatly influenced on the electronic structures and transport properties of quasi-one-dimensional nanomaterials.
Boudria, Yacine; Feltane, Amal; Besio, Walter
2014-06-01
Objective. Brain-computer interfaces (BCIs) based on electroencephalography (EEG) have been shown to accurately detect mental activities, but the acquisition of high levels of control require extensive user training. Furthermore, EEG has low signal-to-noise ratio and low spatial resolution. The objective of the present study was to compare the accuracy between two types of BCIs during the first recording session. EEG and tripolar concentric ring electrode (TCRE) EEG (tEEG) brain signals were recorded and used to control one-dimensional cursor movements. Approach. Eight human subjects were asked to imagine either ‘left’ or ‘right’ hand movement during one recording session to control the computer cursor using TCRE and disc electrodes. Main results. The obtained results show a significant improvement in accuracies using TCREs (44%-100%) compared to disc electrodes (30%-86%). Significance. This study developed the first tEEG-based BCI system for real-time one-dimensional cursor movements and showed high accuracies with little training.
Quantum magnetism in strongly interacting one-dimensional spinor Bose systems.
Dehkharghani, Amin; Volosniev, Artem; Lindgren, Jonathan; Rotureau, Jimmy; Forssén, Christian; Fedorov, Dmitri; Jensen, Aksel; Zinner, Nikolaj
2015-06-15
Strongly interacting one-dimensional quantum systems often behave in a manner that is distinctly different from their higher-dimensional counterparts. When a particle attempts to move in a one-dimensional environment it will unavoidably have to interact and 'push' other particles in order to execute a pattern of motion, irrespective of whether the particles are fermions or bosons. A present frontier in both theory and experiment are mixed systems of different species and/or particles with multiple internal degrees of freedom. Here we consider trapped two-component bosons with short-range inter-species interactions much larger than their intra-species interactions and show that they have novel energetic and magnetic properties. In the strongly interacting regime, these systems have energies that are fractions of the basic harmonic oscillator trap quantum and have spatially separated ground states with manifestly ferromagnetic wave functions. Furthermore, we predict excited states that have perfect antiferromagnetic ordering. This holds for both balanced and imbalanced systems, and we show that it is a generic feature as one crosses from few- to many-body systems.
Directory of Open Access Journals (Sweden)
Katharine N. Farrell
2012-11-01
Full Text Available Wind energy is an emblem of sustainability with the potential to promote a qualitative alternative to current energy systems and nuclear options for CO2 reduction. However, wind farm siting often conflicts with aspirations to conserve traditional landscapes and wildlife habitats. In this paper we adopt a Critical Theory perspective, informed by Herbert Marcuse`s work, to study the discourse concerning wind energy siting in Catalonia, Spain. We give particular attention to how tensions between potentially conflicting sustainability objectives are addressed and by whom. Based on a review of this siting discourse and the application of Marcuse’s theory, we find that the Catalan wind energy siting discourse is both influenced by and reproducing what Marcuse referred to as the ‘one-dimensional thinking’ of technology as ideology: erasing the possibility of critical dialectical thought by subsuming the question of “what should be” under the question of “what is”. This has implications both for how these conflicts are investigated and for the sustainability of decisions taken. We conclude that closer attention to the role of ‘one-dimensional thinking’ in wind energy siting discourses could improve not only the understanding of their logic but might also have the potential to help make them more democratic.
On the numerical solution of the one-dimensional convection-diffusion equation
Directory of Open Access Journals (Sweden)
Dehghan Mehdi
2005-01-01
Full Text Available The numerical solution of convection-diffusion transport problems arises in many important applications in science and engineering. These problems occur in many applications such as in the transport of air and ground water pollutants, oil reservoir flow, in the modeling of semiconductors, and so forth. This paper describes several finite difference schemes for solving the one-dimensional convection-diffusion equation with constant coefficients. In this research the use of modified equivalent partial differential equation (MEPDE as a means of estimating the order of accuracy of a given finite difference technique is emphasized. This approach can unify the deduction of arbitrary techniques for the numerical solution of convection-diffusion equation. It is also used to develop new methods of high accuracy. This approach allows simple comparison of the errors associated with the partial differential equation. Various difference approximations are derived for the one-dimensional constant coefficient convection-diffusion equation. The results of a numerical experiment are provided, to verify the efficiency of the designed new algorithms. The paper ends with a concluding remark.
Structure and stability of one-dimensional detonationsin ethylene-air mixtures
Yungster, S.; Radhakrishnan, K.
2005-06-01
The propagation of one-dimensional detonations in ethylene-air mixtures is investigated numerically by solving the one-dimensional Euler equations with detailed finite-rate chemistry. The numerical method is based on a second-order spatially accurate total-variation-diminishing scheme and a point implicit, first-order-accurate, time marching algorithm. The ethylene-air combustion is modeled with a 20-species, 36-step reaction mechanism. A multi-level, dynamically adaptive grid is utilized, in order to resolve the structure of the detonation. Parametric studies over an equivalence ratio range of 0.5 le φ le 3 for different initial pressures and degrees of detonation overdrive demonstrate that the detonation is unstable for low degrees of overdrive, but the dynamics of wave propagation varies with fuel-air equivalence ratio. For equivalence ratios less than approximately 1.2 the detonation exhibits a short-period oscillatory mode, characterized by high-frequency, low-amplitude waves. Richer mixtures (φ > 1.2) exhibit a low-frequency mode that includes large fluctuations in the detonation wave speed. At high degrees of overdrive, stable detonation wave propagation is obtained. A modified McVey-Toong short-period wave-interaction theory is in excellent agreement with the numerical simulations.