Observation of cone and rod photoreceptors in normal subjects and patients using a new generation adaptive optics scanning laser ophthalmoscope.

We demonstrate the capability of a new generation adaptive optics scanning laser ophthalmoscope (AOSLO) to resolve cones and rods in normal subjects, and confirm our findings by comparing cone and rod spacing with published histology measurements. Cone and rod spacing measurements are also performed on AOSLO images from two different diseased eyes, one affected by achromatopsia and the other by acute zonal occult outer retinopathy (AZOOR). The potential of AOSLO technology in the study of these and other retinal diseases is illustrated

Sensitivity to the pion-nucleon coupling constant in partial-wave analyses of elastic pi-N and NN scattering and pion photoproduction

We summarize results obtained in our studies of the pion-nucleon coupling constant. Several different techniques have been applied to pi-N and NN elastic scattering data, and the existing database for single-pion photoproduction. The most reliable determination comes from pi-N elastic scattering. The sensitivity in this reaction was found to be greater, by at least a factor of 3, when compared with analyses of NN elastic scattering or single-pion photoproduction.Comment: 10 pages, 1 figure. Talk given at the Uppsala workshop on the pion-nucleon coupling constan

Hydrodynamic Design Structural Analysis and Optimization of Marine Propeller Blade

There are many problems to be addressed in the design of marine propeller blade. Among these, the foremost is the efficiency of the propeller. The design of ship propeller involves a number of competing variables including the rake, pitch distribution and blade surface area. The propeller design also aims at achieving high propulsive efficiency at low levels of noise and vibration with reduced cavitation. All of these factors affect vessels top speed, fuel efficiency, and handling. A thorough understanding of propeller dynamics is necessary to design an efficient and reliable propeller blade. Numerical models are commonly used for the dynamic characterization of propeller blades, due to the difficulties of performing full-scale measurements. In contrast, the current research focuses on the hydrodynamic design of a Wageningen B-series four bladed propeller used for marine applications. The analyses presented in this thesis have been divided into three main phases. In the first phase, the hydrodynamic design of Wageningen B-series four bladed marine propeller is carried out, to determine the suitability and applicability of propeller blade for underwater conditions is done by 1) Open water characteristics determination, 2) Cavitation inception point determination for metallic propeller blade. The prevailing conditions applied for evaluating these hydrodynamic characteristics are taken from reference and validated with standard series data. In the second phase of the research, Strength determination of both metallic and composite propeller (E-glass epoxy material) are determined in terms of its stress and free vibration characteristics. Numerical analyses are carried out using suitable numerical methods for the deflection calculations and to determine the stress distribution in the blade foot and the blades at operational load conditions. A modal vibrational analysis for prediction of vibration response was also conducted for the blade, because the composite blades tend to deform more than that of metallic one and the deformation can be used in the analysis of hydrodynamic performance. Experiments are performed to compare the results with that obtained from the numerical analysis. In the last phase Structural optimization of composite propeller was done both for non-hybrid and hybrid composites, (comprises a series of combination of Glass fiber reinforced plastic and Carbon reinforced plastic GFRP & CFRP), using the mid-surface as reference and meshed with shell elements to find out the optimum ply stacking sequence for Interlaminar shear stresses and deflection minimization and operational efficiency improvement of composite propeller blade compared to metallic one. The obtained final stacking sequence of the composite propeller was evaluated by varying the number of layers in steps the Interlaminar shear stresses are calculated, and the results are compared with the metallic propeller. The following basic data are used for analysis and the main points performed during the works are given below. 1. The open water characteristics are predicted computationally on the basis of a validated small sized propeller where the delivered power (PD), the advanced coefficient (Vga), and the propeller revolution (N) are known. 2. The cavitation inception point for the metallic propeller is determined which can be used for structural analysis. 3. The Aluminum propeller blade is replaced with E-glass epoxy material blade and structural analyses for both the materials are carried out. 4. An optimum stacking sequence for composite material blade varied with non-hybrid and hybrid materials are determined. 5. Finally, a comparison has been made with metallic and composite materials in terms of their strength behavior

Focus Point Supersymmetry Redux

Recent results from Higgs boson and supersymmetry searches at the Large Hadron Collider provide strong new motivations for supersymmetric theories with heavy superpartners. We reconsider focus point supersymmetry (FP SUSY), in which all squarks and sleptons may have multi-TeV masses without introducing fine-tuning in the weak scale with respect to variations in the fundamental SUSY-breaking parameters. We examine both FP SUSY and its familiar special case, the FP region of mSUGRA/CMSSM, and show that they are beautifully consistent with all particle, astroparticle, and cosmological data, including Higgs boson mass limits, null results from SUSY searches, electric dipole moments, b -> s gamma, B_s -> mu^+ mu^-, the thermal relic density of neutralinos, and dark matter searches. The observed deviation of the muon's anomalous magnetic moment from its standard model value may also be explained in FP SUSY, although not in the FP region of mSUGRA/CMSSM. In light of recent data, we advocate refined searches for FP SUSY and related scenarios with heavy squarks and sleptons, and we present a simplified parameter space to aid such analyses.Comment: v3: 20 pages, 20 figures, minor numerical error in relic density calculation corrected, fixed contours in figure

On the determination of constitutive parametersin a hyperelastic model for a soft tissue

The aim of this paper is to study a model of hyperelastic materials and itsapplications into soft tissue mechanics. In particular, we first determine an unbounded domain of the constitutive parameters of the model making our smoothstrain energy function to be polyconvex and hence satisfying the Legendre–Hadamard condition. Thus, physically reasonable material behaviour are described by our model with these parameters and a plently of tissues can betreated. Furthermore, we localize bounded subsets of constitutive parameters in fixed physical and very general bounds and then introduce a family of descrete stress–strain curves. Whence, various classes of tissues are characterized. Ourgeneral approach is based on a detailed analytical study of the first Piola–Kirchhoff stress tensor through its dependence on the invariants and on the constitutive parameters. The uniqueness of parameters for one tissue is discussed by introducing the notion of manifold of constitutive parameters, whichis locally represented by possibly different physical quantities. The advantage of our study is that we show a possible way to improve of the usual approachesshown in the literature which are mainly based on the minimization of a costfunction as the difference between experimental and model results