102,219 research outputs found

    Focusing by Plano-Concave lens using Negative Refraction

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    We demonstrate focusing of a plane microwave by a plano-concave lens fabricated from a photonic crystal (PhC) having negative refractive index and left-handed electromagnetic properties. An inverse experiment, in which a plane wave is produced from a source placed at the focal point of the lens is also reported. A frequency dependent negative refractive index, is obtained for the lens from the experimental data which matches well with that determined from band structure calculations

    Beyond Concurrent Chemoradiation: The Emerging Role of PD-1/PD-L1 Inhibitors in Stage III Lung Cancer.

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    Concurrent chemoradiation (cCRT) with platinum-based chemotherapy is standard-of-care therapy for patients with stage III unresectable non-small cell lung cancer (NSCLC). Although cCRT is potentially curative, 5-year overall survival has hovered around 20%, despite extensive efforts to improve outcomes with increasing doses of conformal radiation and intensification of systemic therapy with either induction or consolidation chemotherapy. PD-1/PD-L1 immune checkpoint inhibitors have demonstrated unprecedented efficacy in patients with stage IV NSCLC. In addition, preclinical and early clinical evidence suggests that chemotherapy and radiation may work synergistically with anti-PD-1/PD-L1 therapy to promote antitumor immunity, which has led to the initiation of clinical trials testing these drugs in patients with stage III NSCLC. A preliminary report of a randomized phase III trial, the PACIFIC trial, demonstrated an impressive increase in median progression-free survival with consolidative durvalumab, a PD-L1 inhibitor, compared with observation after cCRT. Here, we discuss the clinical and translational implications of integrating PD-1/PD-L1 inhibitors in the management of patients with unresectable stage III NSCLC

    Phenomenological Analysis of pppp and pˉp\bar{p}p Elastic Scattering Data in the Impact Parameter Space

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    We use an almost model-independent analytical parameterization for pppp and pˉp\bar{p}p elastic scattering data to analyze the eikonal, profile, and inelastic overlap functions in the impact parameter space. Error propagation in the fit parameters allows estimations of uncertainty regions, improving the geometrical description of the hadron-hadron interaction. Several predictions are shown and, in particular, the prediction for pppp inelastic overlap function at s=14\sqrt{s}=14 TeV shows the saturation of the Froissart-Martin bound at LHC energies.Comment: 15 pages, 16 figure

    Film-stability in a vertical rotating tube with a core-gas flow

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    Linear hydrodynamic stability of interface between Newtonian liquid film and core fluid under influence of swirl, core flow, and gravit

    Negative refraction and plano-concave lens focusing in one-dimensional photonic crystals

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    Negative refraction is demonstrated in one-dimensional (1D) dielectric photonic crystals (PCs) at microwave frequencies. Focusing by plano-concave lens made of 1D PC due to negative refraction is also demonstrated. The frequency-dependent negative refractive indices, calculated from the experimental data matches very well with those determined from band structure calculations. The easy fabrication of one-dimensional photonic crystals may open the door for new applications.Comment: 3 pages and 5 figure

    Throughput Optimization in High Speed Downlink Packet Access (HSDPA)

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    In this paper, we investigate throughput optimization in High Speed Downlink Packet Access (HSDPA). Specifically, we propose offline and online algorithms for adjusting the Channel Quality Indicator (CQI) used by the network to schedule data transmission. In the offline algorithm, a given target BLER is achieved by adjusting CQI based on ACK/NAK history. By sweeping through different target BLERs, we can find the throughput optimal BLER offline. This algorithm could be used not only to optimize throughput but also to enable fair resource allocation among mobile users in HSDPA. In the online algorithm, the CQI offset is adapted using an estimated short term throughput gradient without specifying a target BLER. An adaptive stepsize mechanism is proposed to track temporal variation of the environment. We investigate convergence behavior of both algorithms. Simulation results show that the proposed offline algorithm can achieve the given target BLER with good accuracy. Both algorithms yield up to 30% HSDPA throughput improvement over that with 10% target BLER

    Crucial Dependence of ``Precarious'' and ``Autonomous'' phi^4s Upon the Normal-ordering Mass

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    Using the Gaussian wave-functional approach with the normal-ordering renormalization prescription, we show that for the (3+1)-dimensional massive lambda phi^4 theory, ``precarious'' and ``autonomous'' phi^4s can exist if and only if the normal-ordering mass is equal to the classical masses at the symmetrc and asymmetric vacua, respectively.Comment: 6 pages, no figures, Revtex file, accepted for publication in Mod. Phys. Lett.

    Stress-Induced Delamination Of Through Silicon Via Structures

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    Continuous scaling of on-chip wiring structures has brought significant challenges for materials and processes beyond the 32 nm technology node in microelectronics. Recently three-dimensional (3-D) integration with through-silicon-vias (TSVs) has emerged as an effective solution to meet the future interconnect requirement. Thermo-mechanical reliability is a key concern for the development of TSV structures used in die stacking as 3-D interconnects. This paper examines the effect of thermal stresses on interfacial reliability of TSV structures. First, the three-dimensional distribution of the thermal stress near the TSV and the wafer surface is analyzed. Using a linear superposition method, a semi-analytic solution is developed for a simplified structure consisting of a single TSV embedded in a silicon (Si) wafer. The solution is verified for relatively thick wafers by comparing to numerical results obtained by finite element analysis (FEA). Results from the stress analysis suggest interfacial delamination as a potential failure mechanism for the TSV structure. Analytical solutions for various TSV designs are then obtained for the steady-state energy release rate as an upper bound for the interfacial fracture driving force, while the effect of crack length is evaluated numerically by FEA. Based on these results, the effects of TSV designs and via material properties on the interfacial reliability are elucidated. Finally, potential failure mechanisms for TSV pop-up due to interfacial fracture are discussed.Aerospace Engineerin
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