Cyclicity of the adjoint of weighted composition operators on the hilbert space of analytic functions

In this paper, we discuss the hypercyclicity, supercyclicity and cyclicity of the adjoint of a weighted composition operator on a Hilbert space of analytic functions.     

Exergetic and economic evaluation of a novel integrated system for trigeneration of power,refrigeration and freshwater using energy recovery in natural gas pressure reduction stations

Journal of Thermal Analysis and Calorimetry - Nowadays, with increasing energy consumption, global warming, and many problems caused by weather conditions, the tendency to use novel methods of...     

Energetic and exergetic evaluation of methanol synthesis process in a hybridized system of methane cracking,chemical looping combustion,thermal desalination and photovoltaic panels

Journal of Thermal Analysis and Calorimetry - Due to limited energy supply sources and environmental issues, the use of renewable energy to replace fossil fuels and reduce pollution has increased....     

Energy,exergy and pinch analyses of an integrated cryogenic natural gas process based on coupling of absorption–compression refrigeration system,organic Rankine cycle and solar parabolic trough collectors

Journal of Thermal Analysis and Calorimetry - The natural gas entering the liquefaction cycle usually consists of nitrogen, ethane, propane and also heavier hydrocarbons which are economically...     

Monsterwellen aus Licht

Seit Jahrhunderten berichten Seefahrer von gigantischen Wellen, die scheinbar aus dem Nichts und ohne Vorwarnung auftauchen. Erst Mitte der 1990er‐Jahre hat sich die Erkenntnis durchgesetzt, dass es sie wirklich gibt und sie für eine größere Zahl katastrophaler Schiffsunglücke verantwortlich waren. In Experimenten an der University of California in Los Angeles haben wir vor kurzem überraschenderweise in Lichtleitfasern Monsterwellen aus Licht nachgewiesen. Ursache hierfür ist eine Nichtlinearität der Faser.     

Elastic interaction between a point defect and a step

The elastic interaction energy between a point defect or an adatom and a step is calculated. The defect is represented by a localized dipole force while the presence of the step is modelled by a distribution of dipole forces on half of the surface plane. The interaction energy changes sign when the defect goes through the plane perpendicular to the surface and containing the edge of the step. For an adatom, this energy behaves like the inverse of its distance to the edge of the step ; it is attracted to the step on one terrace and repelled from it on the other terrace.     

Diamond-hexagonal semiconductor nanocones with controllable apex angle

We report on the synthesis of nanostructured and crystalline tapered Si and Ge polyhedra via metal-catalyzed chemical vapor deposition. These Si and Ge nanocones (SiNCs, GeNCs) possess tips with near-atomic sharpness, micron-scaled bases, hexagonal cross-sections, and controllable apex angles. High-resolution transmission electron microscopy, selected-area electron diffraction and Raman scattering spectroscopy and analysis indicate that the SiNCs are of the diamond-hexagonal Si(IV) phase.     

Enhanced Raman scattering from individual semiconductor nanocones and nanowires

We report strong enhancement (approximately 10(3)) of the spontaneous Raman scattering from individual silicon nanowires and nanocones as compared with bulk Si. The observed enhancement is diameter (d), excitation wavelength (lambda(laser)), and incident polarization state dependent, and is explained in terms of a resonant behavior involving incident electromagnetic radiation and the structural dielectric cross section. The variation of the Raman enhancement with d, lambda(laser), and polarization is shown to be in good agreement with model calculations of scattering from an infinite dielectric cylinder.     

Optofluidic system for three-dimensional sensing and identification of micro-organisms with digital holographic microscopy

Optofluidic devices offer flexibility for a variety of tasks involving biological specimen. We propose a system for three-dimensional (3D) sensing and identification of biological micro-organisms. This system consists of a microfluidic device along with a digital holographic microscope and relevant statistical recognition algorithms. The microfluidic channel is used to house the micro-organisms, while the holographic microscope and a CCD camera record their digital holograms. The holograms can be computationally reconstructed in 3D using a variety of algorithms, such as the Fresnel transform. Statistical recognition algorithms are used to analyze and identify the micro-organisms from the reconstructed wavefront. Experimental results are presented. Because of computational reconstruction of wavefronts in holographic imaging, this technique offers unique advantages that allow one to image micro-organisms within a deep channel while removing the inherent microfluidic-induced aberration through interferometery.     

Enhancing electrooptic modulators using modulation instability

As electronic operating frequencies increase toward the terahertz regime, new electrooptic modulators capable of low‐voltage high‐frequency operation must be developed to provide the necessary optical interconnects. This Letter presents a new concept that exploits modulation instability to compensate for the intrinsically weak electrooptic effect, χ⁽²⁾. Simulations demonstrate more than 50 times enhancement of electrooptic effect at millimeter wave frequencies leading to a substantial reduction in the required modulation voltage.