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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
281

The Impact of El-Niño and La-Niña on the Pre-Monsoon Convective Systems over Eastern India

Kumar Sahu, Rajesh, Choudhury, Goutam, Vissa, Naresh Krishna, Tyagi, Bhishma, Nayak, Sridhara 06 December 2023 (has links)
El-Niño and La-Niña are believed to change the intensity and frequencies of extreme weather events globally. The present study aims to analyse the impact of El-Niño and La-Niña on the lightning activities of cloud systems and their associated precipitation and thermodynamic indices over the Eastern India regions (Odisha, Jharkhand, and West Bengal) during the pre-monsoon season (March–May). Eastern India receives catastrophic thunderstorm events during the pre-monsoon season. The results suggest that the number of lightning flashes was higher in the El-Niño years than in the La-Niña periods, which helps convective activities to be developed over the study region. The precipitation variations showed similar patterns during El-Niño and La-Niña periods, but the magnitudes were higher in the latter. Results from the analysis of thermodynamic indices show that, during the La-Niña phase, the convective available potential energy (CAPE), convective inhibition (CIN), severe weather threat index (SWEAT), humidity index (HI), and total totals index (TTI) values increased, while the cross total index (CTI) and K index (KI) decreased. In contrast, the vertical total index (VTI) and Boyden index (BI) values showed less significant changes in both El-Niño and La-Niña periods. The anomalies of flash rate densities over most parts of our domain were positive during the El-Niño years and negative during the La-Niña years. Precipitation anomalies had a higher positive magnitude during the La-Niña phase, but had spatial variability similar to the El-Niño phase. The anomalies of most of the thermodynamic indices also showed noticeable differences between El-Niño and La-Niña periods, except for the HI index. El-Niño periods showed higher lightning and increased values of associated thermodynamic indices over eastern India, indicating more pronounced convective systems.
282

Hydrocarbon Sorption in Flexible MOFs: Part I: Thermodynamic Analysis with the Dubinin-Based Universal Adsorption Theory (D-UAT)

Preißler-Kurzhöfer, Hannes, Lange, Marcus, Kolesnikov, Andrei, Möllmer, Jens, Erhart, Oliver, Kobalz, Merten, Krautscheid, Harald, Gläser, Roger 27 October 2023 (has links)
The analysis of empirical sorption equilibrium datasets is still vital to gain insights into material–property relationships as computational methods remain in development, especially for complex materials such as flexible MOFs. Therefore, the Dubinin-based universal adsorption theory (D-UAT) was revisited and evaluated as a simple visualization, analysis, and prediction tool for sorption equilibrium data. Within the theory, gas properties are normalized into corresponding states using the critical temperatures of the respective sorptives. The study shows theoretically and experimentally that the D-UAT is able to condense differences of sorption data visualized in reduced Dubinin plots to just three governing parameters: (a) the accessible pore volume, (b) the reduced enthalpy of sorption, and (c) the framework’s reduced free energy differences (in case of flexible behavior). This makes the theory a fast visualization and analysis tool, the use as a prediction tool depends on rough assumptions, and thus is not recommended.
283

Statistical Analysis of Atmospheric Variables during Tornadic Events in Dixie Alley and Tornado Alley using Proximity Soundings from 1995 to 2015

Schroder, Zoe 06 May 2017 (has links)
Tornadoes frequently occur in Tornado Alley (Northern Texas, Oklahoma, Kansas, and Nebraska) and Dixie Alley (Louisiana, Arkansas, Tennessee, Mississippi, Alabama, and Georgia). This study utilizes sounding variables taken within 2-hours and 80 km of a tornado event for the period 1995-2015 to compare and differentiate between these regions. Data bootstrapping and cluster analysis were used to assess differences and similarities in the environmental data between the regions. Of the variables used, the thermodynamic variables showed the greatest discrimination between Dixie Alley and Tornado Alley tornado environments with Dixie Alley having lower LCL heights and CAPE values as well as higher SREH and BWD values when compared to Tornado Alley. However, due to thermodynamic and kinematic inputs, EHI shows the greatest potential in discriminating between tornadic environments in Dixie Alley and Tornado Alley which is beneficial in severe weather forecasting.
284

The Spatial and Temporal Distributions and Thermodynamic Characteristics of Tornadoes in Mississippi

Call, Jennifer M 13 December 2003 (has links)
The vast majority of severe storm and tornado research is conducted in the natural laboratory of the Great Plains region of the United States. As a result, much of the knowledge and technology applied to storm forecasting is developed in the Great Plains environment. However, it has been shown that there is a maximum of strong and violent tornadoes in the region extending from Arkansas eastward into Alabama. In addition, various researchers have found strong severe storm thermodynamic signatures unique to regions such as the Northeast and Mid-Atlantic. This study has analyzed five decades of tornado data for the state of Mississippi. Thermodynamic results indicate that Mississippi has a tornado environment distinctly different than that of the Great Plains. The spatial distribution of the tornado events also indicates that mesoscale processes between the Earth's surface and the lower troposphere may play a significant role in determining the genesis location of violent tornadoes in the historical Delta region of Mississippi. It is anticipated that an understanding of environments unique to Mississippi tornadoes will lead to better forecasts and more comprehensive storm analysis, which will ultimately save lives and property.
285

Optimization of High-Level Waste Loading in a Borosilicate Glass Matrix by Using Chemical Durability Modeling Approach

Mohammad, Javeed 13 December 2002 (has links)
A laboratory scale study was carried out on a set of 6 borosilicate waste glasses made from simulated high-level nuclear waste. The test matrix was designed to explore the composition region suitable for the long-term geologic disposal of high-temperature-and high-waste-containing glasses. The glass compositions were selected to achieve maximum waste loading without a sacrifice in glass durability. The relationship between glass composition and chemical durability was examined. The qualitative effect of increasing B2O3 content on the overall waste glass leaching behavior has also been addressed. The glass composition matrix was designed by systematically varying the factors: %waste loading and (SiO2+Frit):B2O3 ratio, with (SiO2:Frit) ratio being held constant. In order to assess the chemical durability, the Product Consistency Test (ASTM C-1285) was performed. Under PCT protocol, crushed glass was allowed to react with ASTM type I water under static conditions. All leachate solutions were analyzed by the technique; Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES). A statistical regression technique was utilized to model the normalized release of the major soluble elements, Na, Si, and B, as a function of the individual as well as interactive chemical effects (B2O3, Al2O3, Fe2O3, MnO, SiO2, SrO, Na2O, B2O3*SiO2, B2O3*Al2O3, Fe2O3*Na2O, Al2O3*Na2O, and MnO*SiO2). Geochemical modeling was performed using the computer code EQ3/6 to: (1) determine the saturation states of the possible silicate minerals, a-cristobalite and chalcedony; and (2) predict the most stable mineral phase based on the mineral thermodynamic data. Mineral/water interactions were analyzed by representing the resultant glass data on a Na-Al-Si-O-H stability diagram.
286

Toward an Equation of State for Biosurfactants

Ghobadi Fomeshi, Ahmadreza 17 September 2014 (has links)
No description available.
287

Dynamic Covalent Self-Assembly of 2- and 3-Tiered Stacks

Ren, Fengfeng 10 January 2018 (has links)
No description available.
288

The Energetics of Water Interactions with Adult and Neonatal Skin

Yadav, Santosh January 2009 (has links)
No description available.
289

Cucurbit[n]urils in Self-Assembling Molecular Devices: Thermodynamic and Kinetic Considerations

Ling, Xiaoxi January 2013 (has links)
No description available.
290

Phase equilibria and nucleation in condensed phases: a statistical mechanical study

Apte, Pankaj A. 05 January 2006 (has links)
No description available.

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