Optical Study of the Free Carrier Response of LaTiO3/SrTiO3 Superlattices

We used infrared spectroscopic ellipsometry to investigate the electronic properties of LaTiO3/SrTiO3 superlattices (SLs). Our results indicated that, independent of the SL periodicity and individual layer-thickness, the SLs exhibited a Drude metallic response with sheet carrier density per interface ~3x10^14 cm^-2. This is probably due to the leakage of d-electrons at interfaces from the Mott insulator LaTiO3 to the band insulator SrTiO3. We observed a carrier relaxation time ~ 35 fs and mobility ~ 35 cm^2V^-1s^-1 at 10 K, and an unusual temperature dependence of carrier density that was attributed to the dielectric screening of quantum paraelectric SrTiO3.Comment: 4 pages, 4 figure

Bearing Capacity of Defective Reinforced Concrete Pile in Sand-model Study

Concrete piles that were poorly constructed or analyzed in their soil analyses may have structural or geotechnical defects. To examine such defects, an experimental study was conducted to investigate how a defective reinforced concrete pile behaved. These piles were installed and subjected to a compression axial load in the sand that had relative densities of 30%,60%, and 80%. The tests were performed using four concrete model piles: one intact pile and the other three piles had a structural defect (necking) at three different positions of the pile at (0.25 L from the top, center, and 0.25 L bottom). Geotechnical defect (soft layer or debris) was studied using Styrofoam layer at various vertical distances under the pile toe with Y/D = (0, 0.5, 1 and 1.5) D. The test results showed that the bearing capacity of the structural defect was the most in the case of a neck at 0.25 L from the bottom, followed by a neck at the center, and finally a neck at 0.25 L from the top. In the case of a geotechnical defect, the bearing capacity of the pile decreased with the decrease of the vertical distance between the soft layer and the pile toe

Line tension and structure of smectic liquid crystal multilayers at the air-water interface

At the air/water interface, 4,-8-alkyl[1,1,-biphenyl]-4-carbonitrile (8CB) domains with different thicknesses coexist in the same Langmuir film, as multiple bilayers on a monolayer. The edge dislocation at the domain boundary leads to line tension, which determines the domain shape and dynamics. By observing the domain relaxation process starting from small distortions, we find that the line tension is linearly dependent on the thickness difference between the coexisting phases in the film. Comparisons with theoretical treatments in the literature suggest that the edge dislocation at the boundary locates near the center of the film, which means that the 8CB multilayers are almost symmetric with respect to the air/water interface.Comment: 21 pages, 6 figure

Combination of the Single-Valued Neutrosophic Fuzzy Set and the Soft Set with Applications in Decision-Making

In this article, we propose a novel concept of the single-valued neutrosophic fuzzy soft set by combining the single-valued neutrosophic fuzzy set and the soft set. For possible applications, five kinds of operations (e.g., subset, equal, union, intersection, and complement) on single-valued neutrosophic fuzzy soft sets are presented. Then, several theoretical operations of single-valued neutrosophic fuzzy soft sets are given. In addition, the first type for the fuzzy decision-making based on single-valued neutrosophic fuzzy soft set matrix is constructed. Finally, we present the second type by using the AND operation of the single-valued neutrosophic fuzzy soft set for fuzzy decision-making and clarify its applicability with a numerical example

Ultrasound confirmation of guidewire position may eliminate accidental arterial dilatation during central venous cannulation

<p>Abstract</p> <p>Background</p> <p>Ultrasound guidance during central line insertion has significantly reduced complications associated with this procedure and has led to it being incorporated as standard of care in many institutions. However, inadvertent arterial penetration and dilation remains a problem despite ultrasound guidance and can result in significant morbidity and even mortality. Dynamic ultrasound confirmation of guidewire position within the vein prior to dilation may help to prevent and even eliminate this feared complication.</p> <p>Methods</p> <p>A prospectively collected database of central line insertions for one author utilizing this novel technique was retrospectively reviewed for all incidents of arterial dilation over a period from September 2008 to January 2010.</p> <p>Results</p> <p>During the study period 53 central lines were inserted with no incidents of arterial dilation.</p> <p>Conclusions</p> <p>Ultrasound confirmation of guidewire position has the potential to reduce or eliminate the morbidity and mortality of arterial dilation during central line placement.</p

Constructing Fresnel reflection coefficients by ruler and compass

A simple and intuitive geometical method to analyze Fresnel formulas is presented. It applies to transparent media and is valid for perpendicular and parallel polarizations. The approach gives a graphical characterization particularly simple of the critical and Brewster angles. It also provides an interpretation of the relation between the reflection coefficients for both basic polarizations as a symmetry in the plane

Fresnel coefficients as hyperbolic rotations

We describe the action of a plane interface between two semi-infinite media in terms of a transfer matrix. We find a remarkably simple factorization of this matrix, which enables us to express the Fresnel coefficients as a hyperbolic rotation.Comment: 6 pages, 3 figure

Non-targeted Stressful Effects in Normal Human Fibroblast Cultures Exposed to Low Fluences of High Charge, High-Energy (HZE) Particles: Kinetics of Biologic Responses and Significance of Secondary Radiations.

International audienceThe induction of nontargeted stressful effects in cell populations exposed to low fluences of high-charge (Z) and high-energy (E) particles is relevant to estimates of the health risks of space radiation. We investigated the up-regulation of stress markers in confluent normal human fibroblast cultures exposed to 1,000 MeV/u iron ions [linear energy transfer (LET) ∼151 keV/μm] or 600 MeV/u silicon ions (LET ∼50 keV/μm) at mean absorbed doses as low as 0.2 cGy, wherein 1-3% of the cells were targeted through the nucleus by a primary particle. Within 24 h postirradiation, significant increases in the levels of phospho-TP53 (serine 15), p21(Waf1) (CDKN1A), HDM2, phospho-ERK1/2, protein carbonylation and lipid peroxidation were detected, which suggested participation in the stress response of cells not targeted by primary particles. This was supported by in situ studies that indicated greater increases in 53BP1 foci formation, a marker of DNA damage. than expected from the number of primary particle traversals. The effect was expressed as early as 15 min after exposure, peaked at 1 h and decreased by 24 h. A similar tendency occurred after exposure of the cell cultures to 0.2 cGy of 3.7 MeV α particles (LET ∼109 keV/μm) that targets ∼1.6% of nuclei, but not after 0.2 cGy from 290 MeV/u carbon ions (LET ∼13 keV/μm) by which, on average, ∼13% of the nuclei were hit, which highlights the importance of radiation quality in the induced effect. Simulations with the FLUKA multi-particle transport code revealed that fragmentation products, other than electrons, in cell cultures exposed to HZE particles comprise <1% of the absorbed dose. Further, the radial spread of dose due to secondary heavy ion fragments is confined to approximately 10-20 μm. Thus, the latter are unlikely to significantly contribute to stressful effects in cells not targeted by primary HZE particles

First-principles calculation of the temperature dependence of the optical response of bulk GaAs

A novel approach has been developed to calculate the temperature dependence of the optical response of a semiconductor. The dielectric function is averaged over several thermally perturbed configurations that are extracted from molecular dynamic simulations. The calculated temperature dependence of the imaginary part of the dielectric function of GaAs is presented in the range from 0 to 700 K. This approach that explicitly takes into account lattice vibrations describes well the observed thermally-induced energy shifts and broadening of the dielectric function.Comment: 6 pages, 3 figure