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Quantum Lithography beyond the Diffraction Limit via Rabi Oscillations

Quantum Lithography beyond the Diffraction Limit via Rabi Oscillations

We propose a quantum optical method to do the subwavelength lithography. Our method is similar to the traditional lithography but adding a critical step before dissociating the chemical bound of the photoresist.
Loophole-Free Bell Test for Continuous Variables via Wave and Particle Correlations

Loophole-Free Bell Test for Continuous Variables via Wave and Particle Correlations

We derive two classes of multimode Bell inequalities under local realistic assumptions, which are violated only by the entangled states negative under partial transposition in accordance with the Peres conjecture. Remarkably, the failure of local realism can be manifested by exploiting wave and particle correlations of readily accessible continuous-variable states, with very large violation of inequalities insensitive to detector efficiency, which makes a strong case for a loophole-free test.
Traveling wave and soliton solutions of coupled nonlinear Schrodinger equations with harmonic potential and variable coefficients

Traveling wave and soliton solutions of coupled nonlinear Schrodinger equations with harmonic potential and variable coefficients

Exact traveling wave and soliton solutions, including the bright-bright and dark-dark soliton pairs, are found for the system of two coupled nonlinear Schrodinger equations with harmonic potential and variable coefficients, by employing the homogeneous balance principle and the F-expansion technique.
Linear amplification and quantum cloning for non-Gaussian continuous variables

Linear amplification and quantum cloning for non-Gaussian continuous variables

We investigate phase-insensitive linear amplification at the quantum limit for single-and two-mode states and show that there exists a broad class of non-Gaussian states whose nonclassicality survives even at an arbitrarily large gain. We identify the corresponding observable nonclassical effects and find that they include, remarkably, two-mode entanglement. The implications of our results for quantum cloning outside the Gaussian regime are also addressed.
Low Complexity Non-Iterative Coordinated Beamforming in 2-User Broadcast Channels

Low Complexity Non-Iterative Coordinated Beamforming in 2-User Broadcast Channels

We propose a new non-iterative coordinated beam-forming scheme to obtain full multiplexing gain in 2-user MIMO systems. In order to find the beamforming and combining matrices, we solve a generalized eigenvector problem and describe how to find generalized eigenvectors according to the Gaussian broadcast channels. Selected simulation results show that the proposed method yields the same sum-rate performance as the iterative coordinated beamforming method, while maintaining lower complexity by non-iterative computation of the beamforming and combining matrices. We also show that the proposed method can easily exploit selective gain by choosing the best combination of generalized eigenvectors.
Low Complexity Transmit Antenna Selection with Power Balancing in OFDM Systems

Low Complexity Transmit Antenna Selection with Power Balancing in OFDM Systems

In this paper, we consider multi-carrier systems with multiple transmit antennas under the power balancing constraint, which is defined as the constraint that the power on each antenna should be limited under a certain level due to the linearity of the power amplifier of the RF chain. Applying transmit antenna selection and fixed-power variable-rate transmission per subcarrier as a function of channel variations, we propose an implementation-friendly antenna selection method which offers a reduced complexity in comparison with the optimal antenna selection scheme. More specifically, in order to solve the subcarrier imbalance across the antennas, we operate a two-step reallocation procedure to minimize the loss of spectral efficiency. We also provide an analytic lower bound on the spectral efficiency for the proposed scheme. From selected numerical results, we show that our suboptimal scheme offers almost the same spectral efficiency as the optimal one.
New P-rho-T Data for Nitrogen at Temperatures from (265 to 400) K at Pressures up to 150 MPa

New P-rho-T Data for Nitrogen at Temperatures from (265 to 400) K at Pressures up to 150 MPa

This paper reports P-rho-T data for pure nitrogen measured with a high-pressure, single-sinker magnetic suspension densimeter (MSD) at (265, 293, 298.15, 350, and 400) K. The MSD yields data with less than 0.03 % estimated error over the pressure range of (10 to 200) MPa. A comparison of the experimental data to the equation of state (EoS) developed by Span et al. indicates they are consistent at pressures below 30 MPa.
Variational justification of the dimensional-scaling method in chemical physics: the H-atom

Variational justification of the dimensional-scaling method in chemical physics: the H-atom

The dimensional scaling (D-scaling) method first originated from quantum chromodynamics by using the spatial dimension D as an order parameter. It later has found many useful applications in chemical physics and other fields. It enables, e.g., the calculation of the energies of the Schrodinger equation with Coulomb potentials without having to solve the partial differential equation (PDE). This is done by imbedding the PDE in a D-dimensional space and by letting D tend to infinity. One can avoid the partial derivatives and then solve instead a reduced-order finite dimensional minimization problem. Nevertheless, mathematical proofs for the D-scaling method remain to be rigorously established. In this paper, we will establish this by examining the D-scaling procedures from the variational point of view. We show how the ground state energy of the hydrogen atom model can be calculated by justifying the singular perturbation procedures. In the process, we see in a more clear and mathematical way confirming (Herschbach J Chem Phys 85:838, 1986 Sect. II.A) how the D-dimensional electron wave function "condenses into a particle," the Dirac delta function, located at the unit Bohr radius.
Optimizing Resource Utilization during the Recovery of Civil Infrastructure Systems

Optimizing Resource Utilization during the Recovery of Civil Infrastructure Systems

Postdisaster recovery efforts of damaged civil infrastructure systems need to be optimized in order to alleviate the adverse impacts of natural disasters on local societies and economies. This paper presents an innovative framework that integrates two newly developed models for resource utilization and multiobjective optimization that are designed to optimize these recovery efforts. The developed models provide new and unique capabilities, including (1) allocating limited reconstruction resources to competing recovery projects, (2) estimating the reconstruction duration and cost associated with implementing specific recovery plans, and (3) generating optimal trade-offs between minimizing the reconstruction duration and cost. An application example is analyzed to evaluate the performance of the developed models and demonstrate their capabilities in identifying a wide spectrum of optimal reconstruction plans, where each provides a unique and nondominated trade-off between minimizing the recovery duration and cost. This allows decision makers in emergency management agencies to select and implement reconstruction plans that address various societal and economical needs in the aftermath of natural disasters.
Three-dimensional Bessel light bullets in self-focusing Kerr media

Three-dimensional Bessel light bullets in self-focusing Kerr media

We study three-dimensional (3D) Bessel light-bullet solutions of the nonlinear Schrodinger equation with a photonic lattice potential in the form of squared Bessel functions in polar coordinates, both analytically and numerically.
Influence of scandium on the microstructure and mechanical properties of A319 alloy

Influence of scandium on the microstructure and mechanical properties of A319 alloy

Recycling of aluminum scrap alloys by melting is gaining its importance in foundry sector. During recycling, some of the alloying elements present in scrap alloys eventually become trace/tramp impurities in the recycled alloy. These elements could potentially affect the alloy's microstructure and hence its mechanical properties. In the present work, an attempt has been made to investigate the effect of one of such trace elements on the microstructure and mechanical properties of A319 alloy. The element chosen for the present investigation is scandium (Sc). This paper discusses the effects of the additions of trace amount of Sc on the microstructure and mechanical properties of A319 alloy in as-cast, T6 and T7 heat treated conditions. (C) 2010 Elsevier B.V. All rights reserved.
Low SNR Capacity for MIMO Rician and Rayleigh-Product Fading Channels with Single Co-channel Interferer and Noise

Low SNR Capacity for MIMO Rician and Rayleigh-Product Fading Channels with Single Co-channel Interferer and Noise

This paper studies the ergodic capacity of multiple-input multiple-output ( MIMO) systems with a single co-channel interferer in the low signal-to-noise-ratio (SNR) regime. Two MIMO models namely Rician and Rayleigh-product channels are investigated. Exact analytical expressions for the minimum energy per information bit, E-b/N-0min, and wideband slope, S-0, are derived for both channels. Our results show that the minimum energy per information bit is the same for both channels while their wideband slopes differ significantly. Further, the impact of the numbers of transmit and receive antennas, the Rician K factor, the channel mean matrix and the interference-to-noise-ratio (INR) on the capacity, is addressed. Results indicate that interference degrades the capacity by increasing the required minimum energy per information bit and reducing the wideband slope. Simulation results validate our analytical results.
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DeSIGN: Guided Practice for Sign Language

DeSIGN: Guided Practice for Sign Language

Children learn and practice their vocabulary through interaction with parents and friends as well as through formal instruction at school. However, for deaf children, sign language is the main...
Calcium channels determine how life begins, and ends
Calcium channels determine how life begins, and ends

Calcium channels determine how life begins, and ends

Ongoing work at Weill Cornell Medical College in Qatar (WCMC-Q) is investigating how intracellular calcium (Ca2+) signaling pathways are involved in the very beginning of life as they prepare the...
Taking gas-to-liquid technology to the next level
Taking gas-to-liquid technology to the next level

Taking gas-to-liquid technology to the next level

In the 1920s, two German scientists—Franz Fischer and Hans Tropsch—developed revolutionary chemical reactions that could transform gas into liquid. These reactions proved particularly...
Researchers build the case for wind and wave studies in Qatar
Researchers build the case for wind and wave studies in Qatar

Researchers build the case for wind and wave studies in Qatar

For the first time, fine detail about the wind and wave conditions around the coast of Qatar has been recorded. By arranging the most sophisticated equipment available on the edge of a 500-meter...
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