Divine Vengeance and Human Justice in The Wendish Crusade of 1147

“Crusading as an act of vengeance” is a new paradigm proposed by Susanna A. Throop. In this study I will focus on the question of whether the Wendish Crusade supports an “act of vengeance” paradigm. The study shows us a new understanding of how crusading was conceived as an act of vengeance in the context of the twelfth century. Through textual analysis of medieval sources it has been possible to clarify the course of the concept of divine vengeance, which often used human agents in its execution, as well as the idea of crusading as an act of vengeance. In primary sources which emphasize the necessity of a Holy War against the Wends, the concept of vengeance was intimately connected with the ideas of human justice and divine punishment. Most of these sources are clerical writings which contain biblical allusions in order to justify their aims. This paper shows how the concept of divine vengeance was perceived as an expression of both secular and religious authority, embedded in a series of commonly understood emotional responses in medieval society, and also as a value system compatible with Christianity

Advanced Characterization of Silica–Encapsulated Aluminum Pigments

For environmental reasons, the paints industry shifts from solvent-borne towards water-borne formulations. This change is challenging the business of aluminum pigments, as the hydrogen released by the reaction of aluminum with water degrades the optical properties, besides being a safety concern. In this work, industrial-grade aluminum pigments are encapsulated, by a well-known method, in a silica matrix by sol-gel process using isopropanol - a more suitable solvent for the industry. The effectiveness of the encapsulation process is proven by advanced physical methods (Scanning Electron Microscopy, Energy Dispersive X-Ray Analysis, Selected Area Electron Diffraction, Fourier Transformed InfraRed Spectroscopy, Thermo-Gravimetric Analysis) and by industry-relevant tests (stability in water, hiding power, flop and granulometry). Moreover, advanced surface-applied physical methods (High Resolution Transmission Electron Microscopy combined with Selected Area Electron Diffraction and Scanning Transmission Electron Microscopy, and FT-IR microscopy) clearly show the homogeneity of the resulting pigments, a quality which is highly desirable for practical applications. The results demonstrate that stability comparable to that of pigments passivized by chromium-based inhibitors is easily achieved, for a variety of operating conditions. However, accomplishing a homogeneous silica layer of the right thickness is the determining factor for good optical properties

Development and Application of Multidimensional Computational Models for Hall Thrusters

The goal of this work is to aid the development of high-power Hall-effect thrusters through modeling and simulation. The focus is both on improving the state-of-the-art in the field of Hall thruster numerical simulation, as well as studying several physical processes that are important to Hall thruster development and application. Since Hall thrusters have been in use for more than half a century, they have built a reputation of reliability, however they are known for low power operation with primary applications such as station-keeping and orbit raising. Within the past decade there has been a significant effort to increase the power levels for these electric propulsion devices, but when considering such recent developments, several problems become apparent. First, as we scale these devices to higher power, higher flow rates and more propellant are needed. This translates into increased costs for ground testing, as well as in-space operation. These issues are addressed through a study of an alternative and less ex- pensive option to the ubiquitous xenon gas: krypton. This new chemical species was added to the Hall2De simulation framework and two thrusters were simulated with krypton propellant. Computed thrust values were found to be within 6% for xenon, and within the 2% experimental measurement error for krypton. Next, scaling to higher power leads to more energetic ions impacting the thruster surfaces that may in turn lead to higher observed erosion rates. Therefore, we must consider the problem of discharge channel erosion, which is investigated by simulating an optical experimental diagnostic that is meant to non-invasively determine the erosion rate: cavity-ring-down spectroscopy. The simulation result over predicts the boron number density in the plume by a factor of 3, and this may be attributed to the significant (±50%) uncertainty in the thruster operation time. Further, the desire to scale Hall thrusters to higher power has led to the idea of con- centrically nesting multiple discharge channels into a single thruster. This novel con- figuration has yielded anomalous thrust gains which have been investigated through a cold gas (neutral) simulation of dual channel operation. In conjunction with significant experimental work performed by colleagues at the Plasmadynamics and Electric Propulsion Laboratory (PEPL) it was found that the anomalous thrust gains may be explained based on the near-plume pressure distribution. In an effort to fully characterize the thruster, a plasma simulation of the single channel mode operation was performed, and thrust was matched to within 9%, while discharge current was matched to within 5% of the measured values. Moreover, it was determined that improved modeling capabilities are required in order to simulate the dual-channel or even independent outer-channel operating modes. Therefore, a new Cartesian 2D axisymmetric electron fluid model is developed, verified and then integrated within an existing state-of-the-art hybrid-particle-in-cell framework.PHDAerospace EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/147521/1/horatiud_1.pd

Sub-micron surface plasmon resonance sensor systems

A sensor for detecting the presence of a target analyte, ligand or molecule in a test fluid, comprising a light transmissive substrate on which an array of surface plasmon resonant (SPR) elements is mounted is described. A multi-channel sensor for detecting the presence of several targets with a single micro-chip sensor is described. A multi-channel sensor including collections of SPR elements which are commonly functionalized to one of several targets is also described. The detectors sense changes in the resonant response of the SPR elements indicative of binding with the targets

Modelling Virus Contact Mechanics under Atomic Force Imaging Conditions

In this paper we present a discrete model governing the deformation of a convex regular polygon subjected not to cross a given flat rigid surface, on which it initially lies in correspondence of one point only. First, we set up the model in the form of a set of variational inequalities posed over a non-empty, closed and convex subset of a suitable Euclidean space. Secondly, we show the existence and uniqueness of the solution. The model provides a simplified illustration of processes involved in virus imaging by atomic force microscopy: adhesion to a surface, distributed strain, relaxation to a shape that balances adhesion and elastic forces. The analysis of numerical simulations results based on this model opens a new way of estimating the contact area and elastic parameters in virus contact mechanics studies

Development of a 2D Axisymmetric Electron Fluid Model in Hall Thrusters

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143094/1/6.2017-4632.pd

Radiation Brightening from Virus-like Particles

Concentration quenching is a well-known challenge in many fluorescence imaging applications. Here we show that the optical emission from hundreds of chromophores confined onto the surface of a virus particle 28 nm diameter can be recovered under pulsed irradiation. We have found that, as one increases the number of chromophores tightly-bound to the virus surface, fluorescence quenching ensues at first, but when the number of chromophores per particle is nearing the maximum number of surface sites allowable, a sudden brightening of the emitted light and a shortening of the excited state lifetime are observed. This radiation brightening occurs only under short pulse excitation; steady-state excitation is characterized by conventional concentration quenching for any number of chromophores per particle. The observed suppression of fluorescence quenching is consistent with efficient, collective relaxation at room temperature. Interestingly, radiation brightening disappears when the emitters' spatial and/or dynamic heterogeneity is increased, suggesting that the template structural properties may play a role and opening a way towards novel, virus-enabled imaging vectors that have qualitatively different optical properties than state-of-the-art biophotonic agents