Information protection in content-centric networks

Information-centric networks have distinct advantages with regard to securing sensitive content as a result of their new approaches to managing data in potential future internet architectures. These kinds of systems, because of their data-centric perspective, provide the opportunity to embed policy-centric content management components that can address looming problems in information distribution that both companies and federal agencies are beginning to face with respect to sensitive content. This information-centricity facilitates the application of security techniques that are very difficult and in some cases impossible to apply in traditional packetized networks. This work addresses the current state of the art in both these kinds of cross-domain systems and information-centric networking in general. It then covers other related work, outlining why information-centric networks are more powerful than traditional packetized networks with regard to usage management. Then, it introduces a taxonomy of types of policy-centric usage managed information network systems and an associated methodology for evaluating the individual taxonomic elements. It finally delves into experimental evaluation of the various defined architectural options and presents results of comparing experimental evaluation with anticipated outcomes

Study of a High-Power, Pulsed Plasma Jet with a Magnetic Probe Array and High Frequency Wave Probe

Presented is a method to observe magnetic field characteristics in a three-dimensional volume as well as high frequency waves generated by a pulsed plasma source. This source will produce a plasma jet that exhibits instabilities and magnetic reconnection [1] inside Embry-Riddle’s two meter long, cylindrical plasma chamber. Magnetic reconnection is a process by which a portion of magnetic field energy is transferred into kinetic or thermal energy of plasma [1]. By observing the topology of the magnetic field at distinct locations over many pulses with the magnetic probe array, a three-dimensional vector space can be constructed for the plasma as it evolves over time. The magnetic field observations will be performed with a calibrated magnetic field probe array (MPA) as described in reference [2]. Design and calibration methodology for the high frequency array is motivated from instruments described in reference [3], although key differences are present. By interpreting these data over system parameter variations, the construction of an empirical model will be suggested for the plasma behavior, and heating of the plasma jet will be studied. This study will investigate fundamental plasma physics and applications, such as the drivers and patterns of reconnection and may lead to improved fusion energy generation and pulsed plasma propulsion

Syntheses and Reactions of Early Transition Metal Amidinate Compounds

Homoleptic Groups 4 and 5 metal amide compounds have been used as precursors in CVD/ALD processes to make microelectronic metal oxide thin films. These compounds are often very air sensitive. Ancillary ligands such as amidinates have been used to reduce their air sensitivity and to make their handling easier. Reactions of amidinates with dioxygen and water have thus been used to make metal oxide thin films. Studies of these reactions are important in order to make better precursors and purer thin films. This dissertation focuses on the following areas: (a) Syntheses of zirconium and Group 5 amidinate amides; (b) Studies of the reactions of zirconium amidinate amides with dioxygen or water; (c) Probing the pathway in the formation of an archetypical tungsten alkylidyne complex. Zr[MeC(NiPr)2]2(NMe2)2 [zirconium amidinate amide] has been prepared through three different routes: two salt metathesis reactions and one aminolysis. The aminolysis of M(NR2)n [metal amide] with iPrN(H)C(Me)=NiPr [diisopropylamidine] gives cleaner products in better yields and this route has been chosen to make amidinates in this dissertation. Reactions of zirconium amidinate amide complexes with dioxygen, water or hydrogen peroxide have been studied. Metal-containing products were {(µ-O)Zr[MeC(NiPr)2]2}2 [zirconium amidinate oxo dimer] and {(µ-O)Zr[MeC(NiPr)2]2}n [zirconium amidinate oxo polymer] based on NMR, IR, MS and elemental analysis. Also, the reaction of Zr[MeC(NiPr)2]2(NMe2)2 with dioxygen yields {(m-h2:h2-O2)Zr[MeC(NiPr)2]2}3 [zirconium peroxo amidinate trimer] and its crystal structure is reported. Ta[MeC(NiPr)2](NMe2)4 [tantalum amidinate amide] and carbon tetrachloride undergo an amide-chloride exchange, giving Ta[MeC(NiPr)2](NMe2)3Cl [tantalum amidinate amide chloride]. Ta[MeC(NiPr)2](NMe2)3Cl has also been synthesized through the aminolysis of Ta(NMe2)4Cl [tantalum amide chloride] with a diisopropyl amidine. W(CH2tBu)3(≡CtBu) [tungsten neopentyl neopentylidyne] has been prepared through the reaction of W(OMe)3Cl3 [tungsten chloride methoxide] and Zn(CH2tBu)2 [dineopentyl zinc]. Also, a side product which has been characterized through NMR spectroscopies to be W(OMe)2Cl(CH2tBu)3 [tungsten neopentyl chloride methoxide]

Scoping exercise on fallers’ clinics : report to the National Co-ordinating Centre for NHS Service Delivery and Organisation R & D (NCCSDO)

The National Service Framework for Older People has stated the need for fall-prevention programmes. An appraisal of fallers’ clinics launched by the National Institute for Health and Clinical Excellence (NICE) was suspended because of a lack of information regarding existing services and typology. This project aimed to determine the feasibility of conducting economic modelling to appraise fallers’ clinics. To achieve this a national survey of services and reviews of the evidence of effectiveness of various models of fallers’ clinics and screening tools were undertaken

Unitary and nonunitary approaches in quantum field theory

We use a simplified essential state model to compare two quantum field theoretical approaches to study the creation of electron-positron pairs from the vacuum. In the unitary approach the system is characterized by a state with different numbers of particles that is described by occupation numbers and evolves with conserved norm. The nonunitary approach can predict the evolution of wave functions and density operators with a fixed number of particles but time-dependent norms. As an example to illustrate the differences between both approaches, we examine the degree of entanglement for the Klein paradox, which describes the creation of an electron-positron pair from vacuum in the presence of an initial electron. We demonstrate how the Pauli blocking by the initial electron comes at the expense of a gain in entanglement of this electron with the created electron as well as with the created positron