Several strange objects in the spiral galaxy NGC 6946 are described. One of these objects is the giant stellar complex noted long ago; we suggested that its sharp semicircular western edge is a result of the ram pressure, arising owing to motion of this complex through the H I halo of NGC 6946. We found another enigmatic object, proposing for it the name Red Ellipse; it is located within the is...

The subject of this thesis is the design, analysis, fabrication, and characterization of integrated Bragg grating optical filters. We begin by describing the design and analysis of three essential building blocks needed for integrated Bragg grating filters: waveguides, directional couplers and Bragg gratings. Next, we describe and implement a flexible fabrication methodology for building integr...

The modeling of the spectral behavior of the refractive index of AlGaInAs quaternary IIIV semiconductor alloy in the energy range from 0.4 to 4eV, including the transparent region, is presented. The extended model of interband transition contributions incorporates not only the fundamental absorption edge contribution to the dielectric function, but also contributions from higher energy and indi...

Theory of constraints (TOC) is a management philosophy that seeks to increase throughput (efficiency or performance) of the system by identifying those processes that are constraining the system bottlenecks. There have been very few profound studies of TOC in health care systems. In order to fill this gap, this study was conducted to determine how healthcare systems are utilizing components of ...

Parallel-plate capacitors based on ferroelectric thin films are considered as high density capacitors and varactors. Due to the small thickness of the ferroelectric films, typically less than 1.0 μm, high electric fields are generated even at relatively low voltages inducing piezoelectric effect associated with electrostriction. This induced piezoelectric effect has negative impact on ferroelec...

Discovering hidden details in historical paintings, such as pentimenti, can help reveal historical influences and changing intentions of an artist. Top-down photographs of visible light historical paintings do not capture much of the finer surface detail on the object being photographed. We present a technique using only visible light photography with a specially constructed octagonal reflector...

The surface circulation off the western coast of the Iberian Peninsula is strongly influenced by the atmospheric pressure distribution in the North Atlantic. During the winter season, the combination of the onshore Ekman transport and the geostrophic adjustment of the large-scale oceanic zonal flow causes the appearance of a seasonal poleward along-shore flow named Navidad current. This surface...

We propose and analyze a new type of a resonator in an annular geometry that is based on a single defect surrounded by radial Bragg reflectors on both sides. We show that the conditions for efficient mode confinement are different from those of the conventional Bragg waveguiding in a rectangular geometry. A simple and intuitive approach to the design of optimal radial Bragg reflectors is propos...

Design-Based Research (DBR) is a relatively new intervention method investigating educational designs applied to real-life settings, and with a dual purpose to develop domain theories and to develop the design, iteratively. This paper is an integrative review, which draws on literature and empirical projects to identify and discuss critical elements in DBR, in particular when doing research in ...

In this paper we review some of the dominant topics in fiber Bragg gratings (FBGs). The combination of theory and simulations shows that these structures can use in filters, nonlinear fiber optical applications, soliton propagations etc. We discussed the theory of FBGs, grating solitons, Bragg soliton generation in intrinsic media and birefringence effects in FBGs together with some numerical s...