The Tropical Pacific Warm Pool International Cloud Experiment (TWP-ICE) took place in Darwin, Australia in early 2006. C-band radar data from this experiment were used to characterize tropical anvil areal coverage, height, and thickness during the month-long field campaign. The morphology, evolution, and longevity of the anvil were analyzed as well as the relationship of the anvil to the rest of the precipitating system. In addition, idealized in-cloud radiative heating profiles were created based on the anvil observations. The anvil was separated into mixed (i.e., echo base below 6 km) and ice only categories. The experiment areal average coverage for both types of anvil was between 4-5% of the radar grid. Ice anvil thickness averaged 2.8 km and mixed anvil thickness averaged 6.7 km. No consistent diurnal signal was seen in the anvil, implying that the life cycle of the parent convection was of first order importance in determining the anvil height, thickness, and area. Areal peaks show that mixed anvil typically formed out of the stratiform region. Peak production in ice anvil usually followed the mixed anvil peak by 1-3 hr. Anvil typically lasted 4-10 hr after the initial convective rain area peak. The TWP-ICE experienced three distinct regimes: the active monsoon, dry monsoon, and break periods. During the entire experiment (except the active monsoon period) there was a strong negative correlation between ice anvil thickness and ice anvil height, a strong positive correlation between ice anvil area and thickness, and a greater variance in ice anvil bottom than ice anvil top. Anvil produced during the active regime had the most dramatic in-cloud radiative response with a maximum cooling of 0.45° K day-1 at 12 km, a maximum heating of 3° K day-1 at 9 km, and a secondary maximum heating of 1.2° K day-1 at 5 km.

A spherical indentation test is considered to be invalid if there is presence of a visible mark on the side of the sheet metal facing the anvil and exactly below the indentation. With the available standard loads of the conventional testers such as Brinell and Rockwell hardness testers, it is difficult to avoid this anvil effect while dealing with the sheet metals. The penetration depth increases when the thickness of the sheet is reduced at constant indentation pressures. The reason behind this is the change in mode of deformation. When the thickness of the sheet metal is reduced, and the indentation test is carried out on it, then the sheet metal experiences first indentation, then bending, followed by lifting of the sheet from the anvil which leads to a forging mode of deformation. The modes of deformation were identified using a finite element simulation of the indentation process. Plots of normalized depth against normalized thickness were created for the same indentation pressure, and a second order polynomial curve was fitted to the data points. The equation of this curve quantifies the anvil effect. The anvil effect was identified as a function of sheet thickness, indenter radius, indentation load and two material constants. A method to correct this anvil effect was also developed using the equation representing the anvil effect. It is possible to obtain the equivalent geometry of indentation without anvil effect. A MATLAB program is developed to obtain the parameters defining the curve for the anvil effect. Indentation test on a sheet using three different indenters and corresponding loads is required for this method. For accurate prediction of the equivalent depth of indentation, a lower limit of 10 % and upper limit of 80 % for penetration depth (ratio of depth of indentation and thickness of sheet metal) was identified for the spherical indentation testing on the sheet metals. Verification of the curve fitting model was carried out with the indentation experiments on commercially available Niobium, Al2024-T3, Al7075-T6 and 1020 low carbon steel sheets. These tests show good agreement between fit, prediction, and experiments for the anvil effect.

The primary subject of this thesis is the study of warm dense hydrogen by means of pulsed laser heating in the pressure region 1 to 2 Mbar and temperatures above the melting line, where a liquid-liquid phase transition from the insulating molecular fluid to a conducting atomic hydrogen fluid, so called plasma phase transition (PPT), was predicted to take place. The first evidence of the PPT under static compression is reported. The observations are in agreement with the negative slope phase line predicted by ab initio methods. / Physics

Under pressure small molecular systems exhibit a remarkable degree of polymorphism and unexpected behaviours. Two previously unexplored binary systems, those of niobium{hydrogen and water{oxygen, are explored and their phase diagrams mapped. In the case of water and oxygen, two hitherto unknown clathrate structures are found. A wide study of dense nitrogen at and above room temperature is also reported. The phase diagram of nitrogen is exceptionally complex for a single element and exhibits considerable metastability of phases. Current theoretical understanding of nitrogen has many disagreements with experimental observation. High quality structural data on various previously known phases are reported as well as a novel molecular phase. This new phase, λ-N2, has been studied using Raman spectroscopy and powder x-ray diffrraction. Combining experimental and theoretical results gives a layered structure with intermolecular interactions playing an important role and an apparently weakened intramolecular bond. The dissociation of the nitrogen triple bond is also examined. The amorphous η state is studied via Raman spectroscopy and optical and IR absorbance methods before laser heating at 255 GPa. After heating the sample becomes very much more transparent and shows signs that the nature of the bandgap has changed suggesting that the nitrogen may be in a crystalline atomic phase hitherto unknown. An effort to take nitrogen to considerably higher pressures is reported. A two stage diamond anvil cell was developed using focused ion beam micromachining. Although ultimately unsuccessful, to the author's knowledge this was the first ever attempt at designing such a system to be compatible with small molecular samples and Raman spectroscopy and various conclusions are as to how best to proceed with such developments.

This dissertation uses multiple tools to investigate tropical anvil, i.e., thick, non-precipitating cloud associated with deep convection with the main objectives to provide a climatology of tropics-wide anvil properties and a better understanding of anvil formation, and to provide a more realistic assessment of the radiative impact of tropical anvil on the large-scale circulation. Based on 10 years (1998-2007) of observations, anvil observed by the Tropical Rainfall Measuring Mission (TRMM) Precipitation (PR) shows significant geographical variations, which can be linked to variations in the parent convection. Strong upper level wind shear appears to assist the generation of anvil and may further explain the different anvil statistics over land and ocean. Variations in the large-scale environment appear to play a more important role in anvil production in regions where convection regularly attains heights greater than 7 km. For regions where convection is less deep, variations in the depth of the convection and the large-scale environment likely contribute more equally to anvil generation. Anvil radiative heating profiles are estimated by extrapolating millimeter cloud radar (MMCR) radiative properties from Manus to the 10-year TRMM PR record. When the unconditional anvil areal coverage is taken into account, the anvil radiative heating becomes quite weak, increasing the PR latent heating profile by less than 1 percent at mid and upper levels. Stratiform rain and cirrus radiative heating contributions increase the upper level latent heating by 12 percent. This tropical radiative heating only slightly enhances the latent heating driven model response throughout the tropics, but more significantly over the East Pacific. These modest circulation changes suggest that previous studies may have overemphasized the importance of radiative heating in terms of Walker and Hadley circulation variations. Further, the relationship of cloud radiative heating to latent heating needs to be taken into account for more realistic studies of cloud radiative forcing on the large-scale circulation.

This dissertation establishes a precipitation climatology for common storm types and structures in southeast Texas, investigating diurnal, seasonal, and interannual rainfall variations in addition to climatological differences in raindrop size distributions and storm divergence profiles. Divergence profiles observed by an S-band, Doppler radar are compared to ensemble simulations of ten precipitating systems occurring in warm season, weakly baroclinic, and strongly baroclinic environments. Eight triply-nested mesoscale model simulations are conducted for each case using single- and double- moment microphysics with four convective treatments (i.e., two convective parameterizations and explicit vs. parameterized convection at 9 km). Observed and simulated radar reflectivities are objectively separated into convective, stratiform, and non-precipitating anvil columns and comparisons are made between ensemble mean echo coverages and levels of non-divergence (LNDs). In both the model and observations, storms occurring in less baroclinic environments have more convective rain area, less stratiform rain area, and more elevated divergence profiles. The model and observations agree best for well-organized, leading-line trailing stratiform systems. Excessive convective rain area and elevated LNDs are simulated for several less organized cases. Simulations parameterizing convection on the intermediate grid produced less elevated divergence profiles with smaller magnitudes compared to their explicit counterparts. In one warm season case, double-moment microphysics generated lower LNDs associated with variations in convective intensity and depth, detraining less ice to anvil and stratiform regions at midlevels relative to a single-moment scheme. Similarly, mesoscale convective vortex simulations employing an ensemble-based versus a single-closure convective parameterization produced the least elevated heating structures (closer to observed) resulting in the weakest midlevel vortices. Finally, this dissertation is unique in that some of the data collection and a portion of the analysis involved 95 undergraduates in a five-year research and education program, the Student Operational ADRAD Project (SOAP). In addition to documenting the program's structure and implementation, student-reported experiences, confidence, and interest in performing SOAP tasks are also analyzed. Students participating in SOAP for multiple years were significantly more confident in performing SOAP tasks, more likely to obtain science or meteorology-related employment upon graduation, and more likely to matriculate to graduate programs, suggesting programs like SOAP have a strong influence on students' career outcomes and self-efficacy.

Due to its exceptional mechanical and electrical properties, graphene (one layer sheet of carbon atoms) has attracted a lot of attention since its discovery in 2004. The purpose of this research is to compare the Raman spectra of graphene with plasma treated graphene sheets which have been treated by changing the different parameters affecting the plasma treatment like gas flow, power and pressure and treatment time. The graphene we used for our high pressure studies are 4-5 layer CVD deposited graphene samples prepared by our collaborators in Dr. W. B. Choi’s group. First we report a Raman spectroscopy study of graphene on copper substrate at high pressures. Diamond anvil cell (DAC) was used to generate pressure. In situ Raman spectra were collected at pressures up to 10 GPa. The results indicate that the G band of graphene shifts with pressure significantly (about 5 cm-1/GPa) whereas the 2D band changes very little. The plasma treated samples were loaded into DAC. Raman spectrum was captured. Parts of the spectrum which were not related to the grapheme peak position were eliminated. The background was reduced. Peaks were found and fitted using FITYK software and the shift of each peak compared to its last position was observed when the pressure was increased. Next we studied plasma treated graphene samples treated with different partial pressure treatments under high pressure and compared them to each other using zirconia anvil cell with the same method.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2018-06-11T15:16:19Z No. of bitstreams: 2 Tese - Rosane de Paula Castro - 2018.pdf: 6915380 bytes, checksum: 2dd6980ad13f95405b57166fa1a2637c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-06-11T15:49:37Z (GMT) No. of bitstreams: 2 Tese - Rosane de Paula Castro - 2018.pdf: 6915380 bytes, checksum: 2dd6980ad13f95405b57166fa1a2637c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-06-11T15:49:37Z (GMT). No. of bitstreams: 2 Tese - Rosane de Paula Castro - 2018.pdf: 6915380 bytes, checksum: 2dd6980ad13f95405b57166fa1a2637c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-05-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This thesis presents the structure determination using single crystal x-ray crystallography of four drug candidates under ambient conditions of temperature and pressure, as well as submitted to high pressure. The crystallographic analysis of this type of compound allows to obtain the three-dimensional structure in an unambiguous way. This information is useful for the development process of new drugs in order to achieve the planned properties, such as the study of combinations of the drug with the excipients to be used to guarantee the rate of expected release of the drug in the human body and the optimization of interaction between the drug and the target. Furthermore during the process of drug manufacturing in the pharmaceutical industry polymorphic phases may arise due to the application of pressure, which occurs during grinding and in the preparation of tablets, which may alter the bioavailability, solubility and stability of the medicament. Thus, identifying the conditions under which such modifications may occur guarantees the reliability of the final product. In this sense, the crystallization and crystallographic analysis of drug candidates developed by the Laboratório de Avaliação e Síntese de Substâncias Bioativas (LASSBio) of the Universidade Federal do Rio de Janeiro (UFRJ) was carried out. The compounds analyzed were: LASSBio-1773 and LASSBio-1774, which have hypoglycemic activity, LASSBio-1606, with anti-inflammatory properties, and LASSBio-1735, which has been shown to be active against several types of cancer. For the compounds LASSBio-1774 and LASSBio-1606 X-ray diffraction at high pressures was also performed with Diamond Anvil Cell (DAC), determining their unit cells and analyzing the effects of pressure on the crystalline arrangement. In both compounds reversible phase transitions were observed. The analysis of the structural changes for LASSBio-1774 due to pressure was performed with the aid of strain tensors. / Nesta tese serão apresentados os resultados de determinação estrutural por difração de raios X de monocristais de candidatos a fármacos em condições ambientes de temperatura e pressão, assim como submetidos à altas pressões. A análise cristalográfica desse tipo de composto permite obter a estrutura tridimensional de maneira inequívoca. Essa informação é útil para o processo de desenvolvimento de novos fármacos a fim de se alcançar as propriedades planejadas, tais como o estudo de combinações do fármaco com os excipientes a serem utilizados para garantir a taxa de liberação esperada do fármaco no corpo humano e a otimização da interação entre o fármaco e o alvo. Além disso, durante o processo de produção na indústria farmacêutica, podem surgir fases polimórficas devido à aplicação de pressão, que ocorre durante a moagem e na preparação de comprimidos, podendo alterar a biodisponibilidade, solubilidade e estabilidade do medicamento. Assim, identificar as condições nas quais tais modificações podem ocorrer, garante a confiabilidade do produto final. Nesse sentido, no presente trabalho foram realizadas a cristalização e análise cristalográfica de candidatos à fármacos desenvolvidos pelo Laboratório de Avaliação e Síntese de Substâncias Bioativas (LASSBio) da Universidade Federal do Rio de Janeiro (UFRJ). Os compostos analisados foram: LASSBio-1773 e LASSBio-1774, que possuem atividade hipoglicemiante, LASSBio-1606, com propriedade anti-inflamatória, e LASSBio-1735, que se mostrou ativo contra diversos tipos de câncer. Para os compostos LASSBio-1774 e LASSBio-1606 foi realizada também a difração de raios X em altas pressões, com a Diamond Anvil Cell (DAC), determinando suas células unitárias e analisando os efeitos da pressão sobre o arranjo cristalino. Em ambos os compostos foram observadas transições de fase reversíveis. Para o LASSBio-1774 a análise das mudanças estruturais devidas à pressão foi realizada com o auxílio dos tensores de strain.

In August, 1944, the Allies embarked on one of the "two supreme operations of 1944," Operation Anvil/Dragoon. It is an operation that almost did not happen. Envisioned as a direct supporting operation of Overlord, Anvil soon ran into troubles. Other operations taking away resources away from Anvil in addition to opposition from the highest levels of Allied command threatened Anvil. This thesis chronicles the evolution of this debate, as well as shed light on one of the most overlooked and successful operations the Allies embarked on in World War II.

Identifying the dynamical processes that are active in tropical cirrus clouds is important for understanding the role of cirrus in the tropical atmosphere. This study focuses on analyzing turbulent motions inside tropical anvil cirrus with the use of a Cloud Resolving Model. Convection in the transition from shallow to deep convection has been simulated with Colorado State University Large Eddy Simulator/Cloud Resolving Model System for Atmospheric Model (SAM 6.3) in a high resolution three-dimensional simulation and anvil cirrus formed in the end of this simulation has been analyzed. For model set up, data gathered during the Tropical Rainfall Measuring Mission Large-Scale Biosphere-Atmosphere (TRMM LBA) field experiment in Amazonas, Brazil have been used as large scale forcing. 31 anvil clouds have been localized from a single time step of the simulation, “a snapshot”, of the entire simulated cloud field consisting of convective clouds of different scales and subsequently divided into three categories that represent different stages of the anvil lifetime; growing, mature and dissipating anvil stages. The classification is based on in-cloud properties such as cloud condensate content and vertical velocities. The simulated anvils have been analyzed both individually and as groups to examine the transition from isotropic three-dimensional turbulence in the convective core of the thunderstorm to stratified two-dimensional turbulence in the anvil outflow. A dimensionless number F is derived and used as a measure of the “isotropic” behavior of the turbulence inside the cloud. F is expressed as the ratio between the horizontal part of TKE and the total (horizontal + vertical) Experiments show that SAM 6.3 clearly can resolve turbulent structures and that the transition from isotropic three-dimensional turbulence to stratified two-dimensional turbulence occurs in the middle layers of the mature and dissipating anvil stages. / Sammanfattning av ”Studier av turbulenta rörelser i städmoln med hjälp av numeriska simuleringar av tropisk konvektion”  Städmoln i tropikerna har stor inverkan på strålningsballansen på grund av de är så vanligt förekommande och att de ligger på hög höjd i atmosfären. Att förstå de drivande krafterna som är aktiva i skapandet och underhållandet av städmoln är viktiga för att få en bra bild av rollen städmoln spelar i den tropiska atmosfären. Den här uppsatsen fokuserar på att studera turbulenta rörelser inuti tropiska städmoln med hjälp av en molnmodell. Tropisk konvektion har simulerats med Colorado State University’s molnmodell SAM 6.3 i en högupplöst tredimensionell simulering. Data från en ”ögonblicksbild” av det simulerade molnfältet har analyserats och 31 städmoln har valts ut och studerats vidare. De simulerade städmolnen indelades i tre olika kategorier baserat på utvecklingsstadier; växande städmoln, moget städmoln och skingrade städmoln. Stadieklassificeringen bestämdes beroende på isvatteninnehåll och vertikalhastigheter i molnet. Städmolnen har därefter analyserats både individuellt och som grupper för att lokalisera och analysera övergången från tredimensionell isotropisk turbulens i kärnan av Cb-molnet till tvådimensionell stratifierad turbulens i städmolnet. För att initiera simuleringen användes mätdata insamlade under fältexperimentet TRMM LBA (Tropical Rainfall Measuring Mission Large-Scale Biosphere-Atmosphere) i Amazonas, Brasilien. För att beskriva turbulenta rörelser i molnen togs det dimensionslösa talet 𝐹 fram som ett mått på isotropin. 𝐹 uttrycks som kvoten mellan den horisontella delen av TKE och den totala (horisontell och vertikal). Den här studien visar att den undersökta molnmodellen SAM 6.3 klart kan simulera turbulenta i rörelser i övergången mellan isotropisk till horisontell turbulens i olika stadier av städmolnens livscykel. Mina analyser visar att övergången sker främst i de mellersta skikten av de mogna och skingrade stadierna av städmolnets utveckling.