Quantum State of Neutrons in Magnetic Thin Films and Superlattices

An experiment which describes the quantum states of neutrons in magnetic thin films and superlattices is reviewed.Comment: 3 pages, 3 figures, Neutron New

A study on iterative methods for solving Richards` equation

This work concerns linearization methods for efficiently solving the Richards` equation,a degenerate elliptic-parabolic equation which models flow in saturated/unsaturated porous media.The discretization of Richards` equation is based on backward Euler in time and Galerkin finite el-ements in space. The most valuable linearization schemes for Richards` equation, i.e. the Newtonmethod, the Picard method, the Picard/Newton method and theLscheme are presented and theirperformance is comparatively studied. The convergence, the computational time and the conditionnumbers for the underlying linear systems are recorded. The convergence of theLscheme is theo-retically proved and the convergence of the other methods is discussed. A new scheme is proposed,theLscheme/Newton method which is more robust and quadratically convergent. The linearizationmethods are tested on illustrative numerical examples

Quantum Computation with Ballistic Electrons

We describe a solid state implementation of a quantum computer using ballistic single electrons as flying qubits in 1D nanowires. We show how to implement all the steps required for universal quantum computation: preparation of the initial state, measurement of the final state and a universal set of quantum gates. An important advantage of this model is the fact that we do not need ultrafast optoelectronics for gate operations. We use cold programming (or pre-programming), i.e., the gates are set before launching the electrons; all programming can be done using static electric fields only.Comment: 5 pages, RevTeX4, 5 figures, uses epsf, latexsym, time

THE RE-ENGINEERING OF MANAGERIAL PROCESS IN PUBLIC ADMINISTRATION

The base of this research was a comparative analyse of the international practices in the field, in order to identify the most important tendencies in public services management. Considering the results of this research, there were identified the foundamental principles of an intelligent management model for public management (subsidiarity, public value and deliberative governance). Starting from this point, we proposed a new intelligent management model applicable in romanian public sector, which can be structured into three major components: top management component (executive and deliberative), operational management component (back office) and communication component (front level). As a case study, we focused in particullary on the water supply public service and we developed a methodology for projecting the front-office component starting from the necessity of optimising stakeholder satisfaction.public management, intelligent services, intelligent public organizations, top management, back and front office

Akinetic Tuneable Optical Sources with Applications

Optical Coherence Tomography (OCT) is a modern, non-invasive imaging technique in biomedical research and medical diagnostics. It was initially developed for clinical applications in ophthalmology, providing high-resolution, cross-sectional images of the retina, retinal nerve fibre layer and the optic nerve head. Today, OCT is used for in vivo imaging of almost every type of tissue and it also branched out in fields outside medicine, like industrial or pharmaceutical applications. OCT is a continuously improving imaging technique, benefiting from the development of advanced optical components and broadband optical sources. The objective of the work presented in the thesis was the development of both short and, respectively, long cavity akinetic optical devices, employing several types of dispersive optical fibre components in the cavity, like chirped fibre Bragg gratings, single mode or dispersion compensating fibre, and actively radio-frequency tuned semiconductor optical amplifiers, used as gain media. The use of external modulators, like Fabry-Perot assemblies, rotating mirrors and other mechanical devices is therefore completely eliminated, while versatility is added in the control of the coherence length, output bandwidth, repetition rate and power. The short cavity source was developed in the 1060 nm region, the output power and bandwidth showing a slow decay with the increase of repetition rate up to 250 kHz. Without any booster, the power achieved was 2 mW at 100 kHz. A novel dual-mode-locking mechanism was developed in order to tune an akinetic swept source based on dispersive cavities at a repetition rate close to, but different from the inverse of the cavity roundtrip. Several optical source configurations emitting in the 1060 nm or 1550 nm wavelength region were developed, characterised and tested in OCT applications. For the 1550 nm swept source employing a Faraday Rotating Mirror in a dispersive cavity, sweeping rates in the range of MHz were achieved, from 782 kHz to up to 5 times this value, with proportional decrease in the tuning bandwidth. Linewidths smaller than 60 pm and output powers exceeding 10 mW were measured. OCT topographic imaging was demonstrated. The thesis ends with a proposed broadband investigation of microresonators written in silica glass employing akinetic optical sources at 1550 nm. The work presented in this thesis resulted in several peer reviewed papers, one patent application and several conference presentations, listed after the final conclusions