102,677 research outputs found
Focusing by Plano-Concave lens using Negative Refraction
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.
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
Film-stability in a vertical rotating tube with a core-gas flow
Linear hydrodynamic stability of interface between Newtonian liquid film and core fluid under influence of swirl, core flow, and gravit
Phenomenological Analysis of and Elastic Scattering Data in the Impact Parameter Space
We use an almost model-independent analytical parameterization for and
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 inelastic overlap
function at TeV shows the saturation of the Froissart-Martin
bound at LHC energies.Comment: 15 pages, 16 figure
Negative refraction and plano-concave lens focusing in one-dimensional photonic crystals
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)
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
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
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
- …