This study examines uses of the records continuum model and related continuum concepts and ideas within the broader field of archival research. By analysing the different ways researchers understand and use the model and related concepts the study aims to contribute new knowledge regarding the records continuum model and its roles in contemporary archival science. The study is a literature review within a qualitative, interpretative paradigm. The review method shares some traits with a systematic literature review through systematicity in the search process and the procedure of selecting articles for the study. These were delimited to English written, peer reviewed, archival science articles published 2005-2018 which use the records continuum model (RCM) in their own studies. Systematicity is also present in analysis through a set of questions that seek to link the research goals within the studies with the purposes of using the RCM and the perceived value of its application. This combination of questions offers a method to get hold of some of the functions and roles of the RCM in archival science. An analysis of the research goals within the articles revealed societal as well as theoretical/methodological goals. Different uses of the RCM were further explored – by analysing motives for including the RCM and related concepts as well as the authors descriptions of their application. The identified goals and an interpretation of the ways the RCM and related ideas were used were then connected, and further interpreted with the help of a theoretical framework consisting of (1) the abilities of theoretical frameworks (according to Anfara 2008), (2) a typology of theories in Information Systems studies (according to Gregor 2006) and (3) the purposes of modelling in science (according to Hofman 2017). The results enabled a discussion on the roles of the RCM in archival research. The study is of value since it identifies the goals within some RCM research and connects these goals with the purposes of using the RCM and related ideas, which might support a continuing discussion on the roles of the RCM in archival science. The study further has a merit in providing a survey of the RCM in contemporary research through a perspective “from without”. This perspective is arrived at partly by including studies from both continuum researchers in the know, as well as from individual researchers of different proximity to continuum thinking and the RCM as a theoretical model; partly by the fact that the author is not a researcher within a community of continuum thinkers or researchers. This is a two years master’s thesis in Archival Science.

<div><div><div><p>Numerous fundamental quests and technological advances require trapping light waves. Generally, light is trapped by the absence of radiation channels or by forbid- ding access to them. Unconventional bound states of light, called bound states in the continuum (BICs), have recently gained tremendous interest due to their peculiar and extreme capabilities of trapping light in open structures with access to radiation. A BIC is a localized state of an open structure with access to radiation channels, yet it remains highly confined with, in theory, infinite lifetime and quality factor. There have been many realizations of such exceptional states in dielectric systems without loss. However, realizing BICs in lossy systems such as those in plasmonics remains a challenge. This thesis explores the realization of BICs in a hybrid plasmonic-photonic structure consisting of a plasmonic grating coupled to a dielectric optical waveguide with diverging radiative quality factors. The plasmonic-photonic system supports two distinct groups of BICs: symmetry protected BICs and Friedrich-Wintgen BICs. The photonic waveguide modes are strongly coupled to the gap plasmons in the grating leading to an avoided crossing behavior with a high value of Rabi splitting of 150 meV . Additionally, it is shown that the strong coupling significantly alters the band diagram of the hybrid system, revealing opportunities for supporting stopped light at an off-Γ wide angular span.</p><p>In another study, we demonstrate the design of a BIC-based all-dielectric metasurface and its application as a nanolaser. Metasurfaces have received an ever-growing interest due to their unprecedented ability to control light using subwavelength structures arranged in an ultrathin planar profile. However, the spectral response of meta- surfaces is generally broad, limiting their use in applications requiring high quality (Q) factors. In this study, we design, fabricate, and optically characterize metasur- faces with very high Q-factors operating near the BIC regime. The metasurfaces are coated with an organic lasing dye as an active medium, and their lasing action is experimentally characterized. The proposed BIC-based metasurfaces nanolaser have very favorable characteristics including low threshold, easily tunable resonances, polarization-independent response, and room temperature operation.</p><div><div><div><p>The second part of the thesis deals with the nonlinear phenomenon in nanopho- tonic structures. We developed an advanced full-wave framework to model nonlinear light-matter interactions. Rate equations, describing atomic relaxations and excita- tion dynamics, are coupled to the Maxwell equations using a Lorentzian oscillator that models the kinetics-dependent light-matter interaction in the form of averaged polarization. The coupled equations are discretized in space and time using a finite- difference time-domain method that provides a versatile multiphysics framework for designing complex structures and integrating diverse material models. The proposed framework is used to study gain dynamics in silver nanohole array, reverse saturable absorption dynamic in optical limiters, and saturable absorption in random lasers. This framework provides critical insights into the design of photonic devices and their complementary optical characterization, and serve as an invaluable utility for guiding the development of synthetic materials. It allows accurate physics-based numerical modeling and optimization of the devices with complex micro- and nano-structured materials and complex illumination sources such as non-paraxial structured beams.</p></div></div></div></div></div></div>

In this dissertation, a continuum sensitivity method is developed for efficient and accurate computation of design derivatives for nonlinear aeroelastic structures subject to transient<br />aerodynamic loads. The continuum sensitivity equations (CSE) are a set of linear partial<br />differential equations (PDEs) obtained by differentiating the original governing equations of<br />the physical system. The linear CSEs may be solved by using the same numerical method<br />used for the original analysis problem. The material (total) derivative, the local (partial)<br />derivative, and their relationship is introduced for shape sensitivity analysis. The CSEs are<br />often posed in terms of local derivatives (local form) for fluid applications and in terms of total<br />derivatives (total form) for structural applications. The local form CSE avoids computing<br />mesh sensitivity throughout the domain, as required by discrete analytic sensitivity methods.<br />The application of local form CSEs to built-up structures is investigated. The difficulty<br />of implementing local form CSEs for built-up structures due to the discontinuity of local<br />sensitivity variables is pointed out and a special treatment is introduced. The application<br />of the local form and the total form CSE methods to aeroelastic problems are compared.<br />Their advantages and disadvantages are discussed, based on their derivations, efficiency,<br />and accuracy. Under certain conditions, the total form continuum method is shown to be<br />equivalent to the analytic discrete method, after discretization, for systems governed by a<br />general second-order PDE. The advantage of the continuum sensitivity method is that less<br />information of the source code of the analysis solver is required. Verification examples are<br />solved for shape sensitivity of elastic, fluid and aeroelastic problems. / Ph. D.

The continuum function is a function which maps every infinite cardinal κ to 2κ. We say that a regular uncountable cardinal κ has the tree property if every κ-tree has a cofinal branch, or equivalently if there are no κ-Aronszajn trees. We say that a regular uncountable cardinal κ has the weak tree property if there are no special κ-Aronszajn trees. It is known that the tree property, and the weak tree property, have the following non-trivial effect on the continuum function: (∗) If the (weak) tree property holds at κ++, then 2κ ≥ κ++. In this thesis we show several results which suggest that (∗) is the only restriction which the tree property and the weak tree property put on the continuum function in addition to the usual restrictions provable in ZFC (monotonicity and the fact that the cofinality of 2κ must be greater than κ; let us denote these conditions by (∗∗)). First we show that the tree property at ℵ2n for every 1 ≤ n < ω, and the weak tree property at ℵn for 2 ≤ n < ω, does not restrict the continuum function below ℵω more than is required by (∗), i.e. every behaviour of the continuum function below ℵω which satisfies the conditions (∗) and (∗∗) is realisable in some generic extension. We use infinitely many weakly compact cardinals (for the tree property) and infinitely many Mahlo...

We report on high angular resolution observations of AFGL 2136 at 50 and 100 μm from NASA's Kuiper Airborne Observatory. Our data consist of diffraction-limited scans in two orthogonal directions as well as photometry. The far-infrared (FIR) emission is very compact with an unresolved core and also exhibits low surface brightness wings that extend out to a radius of order 70″ at 100 μm. We have attempted to fit our observations and the photometry and size data at other wavelengths with simple, dust envelope models in order to place limits on the quantity and distribution of dust around AFGL 2136. Spherically symmetric models cannot fit the data, but we show that a simple approximation to a toroidal dust distribution can fit the energy distribution and size data rather well. The successful models imply a density gradient in the cloud of order ρ ∝ r-1.5 and optical depth at 100 μm of order unity.

No description available.

Multiscale modeling is an effective tool for integrating different computational methods, creating a way of modeling diverse chemical and physical phenomena. Presented are studies on a variety of chemical problems at different computational scales and also the combination of different computational methods to study a single phenomenon. The methods used encompass density functional theory (DFT), molecular dynamics (MD) simulations and finite element analysis (FEA). The DFT studies were conducted both on the molecular level and using plane-wave methods. The particular topics studied using DFT are the rational catalyst design of complexes for C—H bond activation, oxidation of nickel surfaces and the calculation of interaction properties of carbon dioxide containing systems directed towards carbon dioxide sequestration studies. Second and third row (typically precious metals) transition metal complexes are known to possess certain electronic features that define their structure and reactivity, and which are usually not observed in their first-row (base metal) congeners. Can these electronic features be conferred onto first-row transition metals with the aid of non-innocent and/or very high-field ligands? Using DFT, the impact of these electronic features upon methane C—H bond activation was modeled using the dipyridylazaallyl (smif) supporting ligand for late, first-row transition metal (M) imide, oxo and carbene complexes (M = Fe, Co, Ni, Cu; E = O, NMe, CMe2). To promote a greater understanding of the process and nature of metal passivation, first-principles analysis of partially oxidized Ni(111) and Ni(311) surface and ultra-thin film NiO layers on Ni(111) was performed. A bimodal theoretical strategy that considers the oxidation process using either a fixed GGA functional for the description of all atoms in the system, or a perturbation approach, that perturbs the electronic structure of various Ni atoms in contact with oxygen by application of the GGA+U technique was applied. Binding energy of oxygen to the nickel surfaces, charge states of nickel and oxygen, and the preferred binding mode of oxygen to nickel were studied to gain a better understanding of the formation of oxide layers. Using density functional theory, the thermodynamic properties for developing interaction potentials for molecular dynamics simulations of carbon dioxide systems were calculated. The interactions considered are Ni + H2O, Ni + Ni, Ni + CO2, CO2 + CO2, CO2 + H2O and H2O + H2O. These systems were chosen as the possible interactions that can occur when carbon dioxide is stored in the ocean. Molecular dynamics simulations using the results from the DFT studies were also conducted. Finally, thermal conduction analysis was performed on layered functionally graded materials (FGM) subjected to thermal shock by sudden cooling of the material in order to investigate the results obtained from three different mixing laws: linear, quadratic, and half-order. The functionally graded material considered was a composite of nickel and carbon nanotubes at different compositions varying from two to five layers. The middle layers for the three to five layers are composed of graded (i.e., gradually changing) percentages of nickel and carbon nanotube. The thermal conductivity, specific heat and density for the composites were calculated depending on the percentages of materials in each layer, and assuming different rules of mixture.

No description available.

No description available.

No description available.