Thesis (Ph. D)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xiv, 108 p.: ill. (some col.). Includes abstract and vita. Advisor: Sherwin J. Singer, Dept. of Chemistry. Includes bibliographical references (p. 100-108).

This work describes the design and development of a velocity map imaging apparatus that will be used to study the laser initiated photochemistry of water ice and other condensed phases. Experiments on methanol ice photolysis using a different apparatus at Kyoto University are described to give an appreciation of the photochemistry and the experimental parameters. Water deposited on a surface at temperatures below 140 K can form an amorphous solid. Amorphous solid water (ASW), which does not exhibit properties of a well-defined phase, is the most profuse phase of water found in astrophysical environments. Chemical characteristics of ASW - in particular its photochemistry - and the physical characteristics closely associated with the structure such as density and surface are reviewed. The correlations between the morphology and the growth conditions of ASW are also described. Methanol is also known to be a component on the icy mantle on interstellar grains. The effects of irradiating amorphous solid methanol by UV photons are discussed. Experiments at Kyoto University have been performed to detect state-selectively nascent OH and CH3 photofragments following photolysis at 157 nm. Information on the velocity distributions was obtained from time-of-flight measurements. At Queen’s University Velocity Map Imaging combined with resonance enhance multiphoton ionization (REMPI) will be used for quantum state-selective detection of the nascent photoproducts and their velocity distribution. To help automate the experiments “virtual instruments” have been created for the hardware components of the experiment using LabVIEW 8.6. The ion optics of the velocity map imaging spectrometer under construction at Queen’s have been characterized using the SIMION 7.0 software package, and the anticipated experimental image of nascent photoproducts has been simulated by a Monte-Carlo-type algorithm. / Thesis (Master, Chemistry) -- Queen's University, 2011-03-03 15:18:04.543

There is strong evidence that water-ice is relatively abundant within permanently shadowed lunar surface materials, particularly at the poles. Evidence for water-ice has been observed within the impact plume of the LCROSS mission and is supported by data gathered from the Lunar Exploration Neutron Detector (LEND) and the Lunar Prospector Neutron Spectrometer (LPNS). Albedo neutrons from the Moon are used for detection of hydrogen, where the epi-thermal neutron flux decreases as hydrogen content increases. The origin on the concentration of water within permanently shadowed regions is not completely understood, and the Lunar Polar Hydrogen Mapper (LunaH-Map) mission is designed to provide a high-resolution spatial distribution of the hydrogen content over the southern pole using a highly elliptical, low perilune orbit. The LunaH-Map spacecraft is a 6U cubesat consisting of the Miniature Neutron Spectrometer (Mini-NS). Mini-NS is not collimated, requiring a low altitude to achieve a higher spatial resolution compared to previous missions. To develop a compact neutron detector for epi-thermal neutrons, the Mini-NS comprises of 2-cm thick slabs of CLYC (Cs2LiYCl6), which provide a sensitivity similar to a 10-atm, 5.7-cm diameter He-3 tubes, as used in LPNS. The Mini-NS digital processing electronics can discriminate by shape and height to determine signal (albedo neutrons) from background (cosmic rays). The Mini-NS achieves a total active sensing area of 200 cm(2) and is covered with a cadmium sheet to shield against thermal neutrons. The research and development on the detector modules show a robust design ready for space flight.

There are many public health organizations with guidelines concerning the best first-aid treatment for burn injuries. The Australian and New Zealand Burn Association recommends that a burn wound should be cooled with tap water (8-20°C) for 20 minutes, up to three hours after the injury has occurred. However, the evidence that these guidelines are based on is inconclusive and contradictory. As a result of the conflicting published data, there is controversy over whether ice water or ice may confer any beneficial wound healing effects, and what temperature of water is optimal. In the wider community there are also many different alternative therapies believed to be beneficial for the treatment of burn injuries which do not have much evidence to support their use. In this study, patients were found to use agents such as Aloe vera, tea tree oil dressings, butter, toothpaste, papaya ointment and moisturizer on the burn wound. The aim of this work was to review the current field of first-aid treatment for burn injuries and obtain evidence for the optimum first aid treatment using a good animal model, with clinically relevant assessments of wound healing and scar formation. The mechanisms behind the best first aid treatment were also investigated in an effort to better understand and identify the factors involved in optimal wound healing. Studies showed that cool running water at 15°C and 2°C improved the speed of wound healing, gave a better cosmetic outcome and decreased amounts of scar tissue compared to untreated controls. Other treatments Aloe vera, tea tree oil dressings, ice and saliva did not improve wound healing compared to untreated controls. All cold treatments acted to decrease the subdermal temperature, however as the running water was beneficial for wound healing whereas the ice was not, this suggests that the running water acts through other non-thermal mechanisms. Further studies showed that immediate treatment with 15°C water for 20 minutes duration significantly improved the re-epithelialization for 2 weeks post-burn and decreased the distribution of scar tissue compared to untreated controls, however durations as short as 10 minutes and delays of treatment for 1 hour (and perhaps longer) were also beneficial. An audit of first aid used by pediatric patients demonstrated that although 86.1% of patients used first aid, only 12.1% applied the recommended first aid treatment of cold water for 20 or more minutes. For those that did use correct first aid, re-epithelialization time and number of hospital visits were significantly reduced for children with contact and flame burns, respectively. Inadequate first aid treatment was also found to be more common for children <3.5 years old and for friction burn injuries. These studies provide compelling evidence that correct first aid treatment of burn injuries results in improved clinical outcomes, which benefit the patient as well as health care providers. There is a definite need for greater public awareness concerning the correct first aid treatment to use for burn injuries.

Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (p. 115-123).

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Title: Dynamics of icy satellites with a liquid phase Author: Klára Kalousová Department: Department of Geophysics Department: Laboratoire de Planétologie et Géodynamique de Nantes Supervisors: Doc. RNDr. Ondřej Čadek, CSc. upervis ors: Dr. Gaël Choblet Abstract: Jupiter's moon Europa has a young surface with a plethora of unique terrains that indicate recent endogenic activity. Morphological models and spectral observations suggest that it possesses an internal ocean as well as shallow pockets of liquid water within its outer ice shell. Presence of water in a chemically rich environment and a longterm energy source ensured by tidal heating, make Europa one of the best candidates for habitability, for which the material exchange between the surface and the ocean is critical. In this thesis, we investigate internal melting and subsequent meltwater evolution within Europa's ice shell by using a two-phase formalism developed for this context. Results of a parametric study for a temperate ice shell indicate that the time scale of water transport by porous flow is governed by the ice permeability, while the ice viscosity affects the solution wavelength. We then consider a polythermal ice shell with two melting scenarios: (i) In a tidally-heated convecting ice shell, melting occurs mainly in its lower half and...

The presented thesis focuses on designing a cryogenic cell for the study of water ice in an environmental scanning electron microscope (ESEM). This cell allows the study ice in the temperature range 80 K – 300 K in a nitrogen gas environment with a pressure of up to 400 Pa. The cell is cooled by a flow cooling system, where liquid or gaseous nitrogen is used as a refrigerant. The cell consists of a double-walled vessel with vacuum insulation, a flow-through heat exchanger, a sample well, and a cooled cell lid. The heat exchanger was designed to be able to dissipate the heat load at the level of 1 W. The exchanger is equipped with an electric resistance heater with an output of approximately 60 W, enabling heating of the sample at speeds of up to 100 K·min-1. The design also includes an LN2 gateway located on the door of the vacuum chamber of the microscope, to which the capillaries of the heat exchanger for the intake and outlet of refrigerant are connected. During the experimental verification of the cryogenic cell in the test vacuum chamber with a pressure of GN2 ~ 400 Pa, the limit temperature of 77.5 K on the sample well was reached.

Electronic coarse graining is a technique improving the predictive power of molecular dynamics simulations by representing electrons via a quantum harmonic oscillator. This construction, known as a Quantum Drude Oscillator, provides all molecular long-range responses by uniting many-body dispersion, polarisation and cross interactions to all orders. To demonstrate the predictive power of electronic coarse graining and provide insights into the physics of water, a molecular model of water based on Quantum Drude Oscillators is developed. The model is parametrised to the properties of an isolated molecule and a single cut through the dimer energy surface. Such a parametrisation makes the condensed phase properties of the model a prediction rather than a fitting target. These properties are studied in four environments via two-temperature adiabatic path integral molecular dynamics: a proton ordered ice, the liquid{vapour interface, supercritical and supercooled water. In all these environments, the model predicts a condensed phase in excellent agreement with experiment, showing impressive transferability. It predicts correct densities and pressures in liquid water from 220 K to 647 K, and a correct temperature of maximum density. Furthermore, it predicts the surface tension, the liquid-vapour critical point, density of ice II, and radial distribution functions across all conditions studied. The model also provides insight into the relationship between the molecular structure of water and its condensed phase properties. An asymmetry between donor and acceptor hydrogen bonds is identified as the molecular scale mechanism responsible for the surface orientation of water molecules. The dipole moment is identified as a molecular scale signature of liquid-like and gas-like regions in supercritical water. Finally, a link between the coordination number and the anomalous thermal expansion of the second coordination shell is also presented.

La planète Mars est le siège d'un climat complexe, caractérisé par des cycles du dioxyde de carbone et de l'eau, ainsi qu'un transport de poussière à toutes les échelles. Ces cycles se manifestent par la condensation saisonnière aux pôles de dépôts de glace de CO₂ et d'eau pendant la nuit polaire, et leur sublimation pendant le printemps local. Les cycles du CO₂ , de l'eau et des poussières sur Mars sont intimement liés. Un processus saisonnier actif illustre bien ces liens : les jets de gaz froid, déclenchés par la sublimation saisonnière des dépôts de CO₂ , pouvant mettre en suspension des poussières du régolite de manière durable dans l'atmosphère, et dont l'activité semble être modulée par les échanges d'eau à la surface.L'objectif de cette thèse est de permettre l'utilisation des données d'imagerie hyperspectrale disponibles au maximum de leur potentiel, pour apporter de nouvelles contraintes sur les échanges saisonniers entre surface et atmosphère et sur les interactions entre les différents cycles (CO₂ , eau, poussières), en se focalisant sur les jets de gaz froid. Pour cela, un modèle semi-analytique de transfert radiatif dans les glaces compactes, ainsi qu'une méthode efficace d'inversion ont été développés et validés.Le modèle de transfert radiatif permet de décrire l'interaction de la lumière avec une couche de glace de manière quantitative d'après les paramètres suivants : épaisseur de la couche, proportions volumiques et tailles des impuretés, rugosité de la surface. Il repose sur plusieurs hypothèses majeures : optique géométrique, milieux continus par morceaux, inclusions quasi-sphériques. L'approximation des deux flux est utilisée pour le transfert au sein de la couche mais la réflexion spéculaire en surface est estimée en tenant compte de la variabilité des facettes de la rugosité surfacique. Ce modèle a été validé numériquement et sur des données de laboratoire et des tests numériques. La méthode d'inversion consiste à créer des bases de données synthétiques d’après le modèle de transfert radiatif pour déterminer les jeux de paramètres les plus probables pour reproduire une mesure donnée. L'inversion repose sur le formalisme bayésien : les grandeurs manipulées sont décrites par des densités de probabilités. Ceci permet la prise en compte de manière réaliste des incertitudes sur la donnée et le calcul d'une incertitude a posteriori sur le résultat de l'inversion.Une étude ciblée d'un site d'intérêt a été menée pour tester et démonter l'applicabilité de cette démarche à l'inversion massive de données de spectro-imagerie.Nous avons déterminé l’état de surface du champ de dunes du cratère de Richardson (72°S, 180°W), choisi car il présente de fortes interactions entre cycle de l'eau et du CO₂ , une important activité saisonnière de jets froids mais aussi une grande quantité de données disponible et une haute qualité du suivi temporel. Le suivi des caractéristiques de surface sur ce site montre une diminution de l'épaisseur de la couche de glace pendant le printemps cohérente avec les estimations des modèles de climat. Nous avons pu estimer et faire le suivi du contenu en eau et en poussière pour discuter le scénario de formation des jets froids. Nous avons proposé un nouveau mécanisme de mise en suspension des petits grains d’eau. / Mars has a complex climate, characterized by carbon dioxide and water cycles, and dust transport at all scales. These cycles are mainly controlled by the seasonal condensation of CO₂ and water ice deposits at high latitudes during the polar night and their sublimation during the local spring. There are a lot of interactions between the CO₂ , water and dust cycles on Mars and they influence each other. An active seasonal process illustrates particularly well these links: the cryoventing, cold CO₂ gas jets triggered by seasonal sublimation of CO₂ deposits, which can put dust from the regolith in suspension into the atmosphere durably, and whose activity seems to be modulated by the exchange of water at the surface.The purpose of this thesis is to allow the use of the available hyperspectral imaging data to their full potential, to bring new constraints on seasonal exchanges between surface and atmosphere and the interactions between the different cycles (CO₂ , water , dust), focusing on cold gas jets. To achieve this, a semi-analytical radiative transfer model in compact ices and an effective inversion method were developed and validated.The radiative transfer model describes the interaction of light with a surface quantitatively, using the following parameters: thickness of the layer, volume proportions and grain-sizes of impurities, surface roughness. It is based on several key assumptions: geometrical optics, piecewise-continuous media quasi-spherical inclusions. The two-stream approximation is used for the radiative transfer inside the layer, but the surface specular reflectance is estimated taking into account the variability of the facets orientations from the surface roughness. This model was validated both numerically and on laboratory data.The inversion method consists in exploring synthetic databases generated by the radiative transfer model and determining the most likely sets of parameters to reproduce a given measure. The inversion is based on the Bayesian formalism: the manipulated variables are described by probability density functions. This allows to take into account realistic uncertainties on the data and enables to calculate a posteriori uncertainties on the result of the inversion.A focused study was conducted on a area of particular interest, to test and prove the applicability of this approach to the massive inversion of spectro-imaging data. The dune-field of Richardson Crater (72°S, 180°W) was chosen because it shows strong interactions between the water and CO₂ cycles, a major seasonal cryoventing activity, but also a large amount of data available and a high quality temporal monitoring. The monitoring of surface characteristics on this site shows a decrease in the thickness of the ice during the spring consistently with climate models simulations. We were able to estimate and monitor the content of water and dust in order to discuss the formation scenario of cold jets.