Engineering Commons^™

Thermomechanical Process Simulation And Quantification Of Nanoscale Precipitation Influencing Ductility And Strength During Alloy Processing, Alyssa Stubbers

Theses and Dissertations--Chemical and Materials Engineering

Experimental process simulation and quantification of microstructure development during processing are challenging due to limitations with machinery temperature capability, inadequate resolution and sampling volume of currently available characterization techniques, and difficulty characterizing material microstructures as close to processing-relevant conditions as possible. This dissertation addresses how process simulation can be performed using Gleeble thermomechanical technologies and how microstructure development during these processing simulations can be quantified both in-situ and ex-situ.

The first portion of this dissertation demonstrates how Gleeble technologies can be applied to simulate complex material processing conditions in order to produce process-property profiles that can be used to inform …

Characterization Of Residual Stress And Precipitate Evolution In Aluminum 2xxx Self-Reacting Friction Stir Welds, Benjamin Joe Wing

Doctoral Dissertations

2xxx series aluminum alloys possess attractive properties for structural aerospace applications including high strength to weight ratio, corrosion resistance, and stable cryogenic performance. Solid state joining processes are often employed to reduce weld defects and improve weld performance/consistency as many alloys of this range have poor weldability for traditional fusion based joining techniques. One such process, self-reacting friction stir welding (SRFSW) allows for consistent high-quality, welding of large and curved articles is often used in the construction of large structures such as launch vehicle liquid propellant tanks.

Despite the merits of this process, joint softening (a decrease in mechanical properties …

Moisture Sources Of Precipitation In The Great Lakes Region: Climatology And Recent Changes, Zhao Yang, Yun Qian, Pengfei Xue, Jiali Wang, T. C. Chakraborty, William J. Pringle, Jianfeng Li, Xiaodong Chen

Michigan Tech Publications

Given the critical role of precipitation on hydroclimate, we quantified the contributions of moisture source regions to precipitation in the Great Lakes Region (GLR) using multiple reanalysis data sets. Results show that the Great Plains (GPs) and the GLR itself are the primary sources of moisture. The moisture sources for the double peaks in the GLR precipitation that occur in June and September are identified, which is caused by a shift in the peak timing of moisture contribution from the GLR and GPs. In particular, moisture from the GPs contributes more to the heavy precipitation, while moisture from the GLR …

Quantifying A 21-Year Surface Water And Groundwater Interaction In A Ridge And Valley Lake Environment Using A Highly Constrained Modeling Approach, Richard T. Bowers Jr.

USF Tampa Graduate Theses and Dissertations

Karst lakes are ubiquitous in ridge terrain settings in limestone aquifer coastal plain environments. In west-central Florida, these lakes are frequently connected to the Upper Floridan aquifer and have unique aquifer recharge characteristics. They have been selectively studied because they commonly have no or very limited surface water discharge and limited drainage areas, have appreciable surface water and groundwater interaction and leak to the deep aquifer. An innovative modeling approach was developed to collectively understand and more precisely quantify this vertical leakage, both from a lake-specific and regional water budget standpoint, for a 21-year study period (2000-2020). A unique, calibrated …

Interfacial Interactions Of Uranium And Hdpe In Agricultural Soil And Their Bioacummulation In Mentha Arvensis, Casey Miller, Andrew Neidhart, Kendra Hess, Abdul-Mehdi S. Ali, Angelica Benavidez, Michael Spilde, Laura Green, José M. Cerrato, Jorge Gonzalez Estrella, Eliane El Hayek

Civil Engineering ETDs

We investigated the adsorption, precipitation, and phytoavailability of uranium after reactions with soil, high-density polyethylene particles, and Mentha arvensis through the integration of batch experiments, plant exposure, microscopy, and spectroscopy. Soluble U (initially 100 µM) decreased by 98.6% (1.09 µM) at pH 5 and 86.2% (13.81 µM) at pH 7.5 after 0.1 h of reaction with 10 g of soil in solution. Heterogenous U precipitates were observed in weathered HDPE surfaces for experiments without soil at both pH conditions. This suggests the weathering of the microplastic surfaces enhanced the nucleation of the U precipitates. Plants exposed to both U and …

Classifying Mixing Regimes In Ponds And Shallow Lakes, Meredith A. Holgerson, David C. Richardson, Joseph Roith, Lauren E. Bortolotti, Kerri Finlay, Daniel J. Hornbach, Kshitij Gurung, Andrew Ness, Mikkel R. Andersen, Sheel Bansal, Jacques C. Finlay, Jacob A. Cianci-Gaskill, Shannon Hahn, Benjamin D. Janke, Cory Mcdonald, Jorrit P. Mesman, Rebecca L. North, Cassandra O. Roberts, Jon N. Sweetman, Jackie R. Webb

Michigan Tech Publications

Lakes are classified by thermal mixing regimes, with shallow waterbodies historically categorized as continuously mixing systems. Yet, recent studies demonstrate extended summertime stratification in ponds, underscoring the need to reassess thermal classifications for shallow waterbodies. In this study, we examined the summertime thermal dynamics of 34 ponds and shallow lakes across temperate North America and Europe to categorize and identify the drivers of different mixing regimes. We identified three mixing regimes: rarely (n = 18), intermittently (n = 10), and often (n = 6) mixed, where waterbodies mixed an average of 2%, 26%, and 75% of the study period, respectively. …

Co-Occurrence Of Microplastics, Uranium And Arsenic In Heavy Metal-Contaminated Freshwaters And Their Potential Interaction, Jasmine Anne Quiambao

Civil Engineering ETDs

This study identified microplastics and heavy metals in fields sites of freshwater systems in New Mexico and evaluated the interactions of arsenic (As) and uranium (U) with commercial microplastics for acidic and neutral pH in laboratory-controlled conditions. The potential interaction of microplastics with other contaminants is not well-established. Microplastics could interact with heavy metals in ecosystems with naturally elevated background concentrations of metals or affected by anthropogenic activities. Previous studies have found heavy metal contamination in freshwater systems in New Mexico near abandoned mine sites. The objective of this study is (1) to identify and characterize microplastics from metal contaminated …

Copulas For Hydroclimatic Analysis: A Practice-Oriented Overview, Faranak Tootoonchi, Mojtaba Sadegh, Jan Olaf Haerter, Olle Räty, Thomas Grabs, Claudia Teutschbein

Civil Engineering Faculty Publications and Presentations

A warming climate is associated with increasing hydroclimatic extremes, which are often interconnected through complex processes, prompting their concurrence and/or succession, and causing compound extreme events. It is critical to analyze the risks of compound events, given their disproportionately high adverse impacts. To account for the variability in two or more hydroclimatic variables (e.g., temperature and precipitation) and their dependence, a rising number of publications focuses on multivariate analysis, among which the notion of copula-based probability distribution has attracted tremendous interest. Copula is a mathematical function that expresses the joint cumulative probability distribution of multiple variables. Our focus is to …

Precipitation And Temperature Extremes And Association With Large-Scale Climate Indices: An Observational Evidence Over India, S Rehana, Pranathi Yeleswarapu, Ghouse Basha, Francisco Munoz-Arriola

Biological Systems Engineering: Papers and Publications

Climate change exposes more frequent natural hazards and physical vulnerabilities to the built and natural environments. Extreme precipitation and temperature events will have a significant impact on both the natural environment and human society. However, it is unclear whether precipitation and temperature extremes increase physical vulnerabilities across scales and their links with large-scale climate indices. This study investigates the relationship between precipitation and temperature extremes, as recommended by the Expert Team on Climate Change Detection and Indices (ETCCDI), and large scale climatological phenomenon indices (Indian Summer Monsoon Index (ISMI), Arctic Oscillation (AO), and North Atlantic Oscillation (NAO)), using India as …

On A New Framework For Detecting, Classifying, And Forecasting Floods For Large-Scale Flood Risk Analysis, Equisha Glenn

Dissertations and Theses

Increasing trends in flooding events are projected to continue as climate changes have increased the chance of extreme weather events. Given the significant, damaging impacts of extreme floods, the ability to effectively model floods is crucial for risk management and mitigation of the impacts of these extreme flooding events. This dissertation presents a new framework for detecting and predicting large-scale flood risk in the United States using climate information. This methodology categorizes regional, simultaneous floods into an index that is used to forecast the risk of extreme flooding a season ahead. The index proposed herein, named the Spatial Flood Index …

Synthesis Of Sodium Ammonium Hydrophosphate And Sodium Dihydrophosphate Based On Extraction Phosphoric Acid From Central Kyzylkum Phosphorites, Kamola Arifdjanova, Kholtura Mirzakulov, Sherzod Khujamberdiev, Melikulova Gavkhar

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the research is the synthesis of sodium ammonium hydrogen phosphate and sodium dihydrogen phosphate based on purified extraction phosphoric acid.

The acid was purified from accompanying impurities by precipitation methods using sodium carbonate and metasilicate, washed burnt phosphoconcentrate, barium carbonate, acid neutralization with gaseous ammonia. Pre-neutralization of the purified solution of monoammonium phosphate with sodium carbonate to the ratio Na₂O:P₂O₅ = 0.44 and subsequent drying at a temperature of 50 °С allows to obtain sodium ammonium hydrogen phosphate tetrahydrate, and at 100 °С sodium dihydrogen phosphate monohydrate.

The individuality and purity of …

The Impact Of Precipitation On The Groundwater Of Coal Waste Dump, Tomasz Suponik, Dawid Franke, Robert Frączek, Katarzyna Nowińska, Piotr Pierzyna, Zenon Różański, Paweł Wrona

Journal of Sustainable Mining

The aim of the study was to assess the effect of climate change, mainly higher and lower precipitation, on the intensity of the impact of a coal waste dump on groundwater. The analysis used meteorological data for the Katowice region in 2002-2020 as well as data on the height of the groundwater table in the vicinity of the coal waste dump, and data on physicochemical parameters and chemical composition of groundwater in 2004-2020. Based on the analyses, it was found that the periods of drought in the Silesian Voivodeship, located in the south of Poland, occurred mainly in spring, while …

Quantification Of Climate Variability And Extreme Events In The Great Plains, Angelinah Ntsieng Rasoeu

Electronic Theses and Dissertations

Climate variability and extreme events continue to worsen resulting in significant impacts to society and the environment. Quantifying precipitation variability, streamflow, and extreme events at local scale is crucial for local planning and management due to spatial and temporal precipitation variability which influences streamflow and thus, water resources. This study uses statistical tools to analyze 1895-2019 (125 years) of historical precipitation data to examine how long-term precipitation varies annually, seasonally, and monthly, and create climate classifications. The results show that annual precipitation is increasing linearly over time ranging from 13.2 in (1976) to 43.1 in (2010) and 5 climate classes …

Studying The Relationship Between Indigenous Microbial Communities, Urease Activity, And Calcite Precipitation In Artificial Mixes Of Clay And Sand, Somaye Asghari, Bhaskar C. S. Chittoori, Malcolm Burbank, Nick Hudyma

Civil Engineering Faculty Publications and Presentations

Microbial-induced calcium carbonate precipitation (MICP) is evolving as a new method of improving the mechanical properties of soil. This environmentally friendly technique is a bio-geo-chemical process where microbes play a key role in increasing soil strength through precipitating calcium carbonate. Past studies at Boise State University have indicated that MICP via bio-stimulation could be a viable alternative for expansive clayey soil treatments. However, these studies raised a new question about the relationship between soil composition, urease activity, and calcite precipitation. To answer this question, batch studies were conducted using autoclaved-sterilized sand mixed with different percentages of non-sterile natural clay and …

Evaluation And Bias Correction Of Remotely Sensed Precipitation Products Across Canada, Saber Moazamigoodarzi

Electronic Thesis and Dissertation Repository

Reliable estimation of precipitation, as the most important variable in hydrological modelling, is crucial for water resources management. Rain gauges that provide precipitation measurements at point scale have inherent limitations and difficulties in remote regions and complex terrains due to accessibility, gauge undercatch, among others. Alternatively, satellite and radar precipitation data can estimate precipitation at high spatial and temporal resolution by utilizing several types of space and ground-borne sensors. However, due to the indirect estimates of precipitation by remotely sensed products, their measurements are subject to systematic biases and are required to be evaluated and bias adjusted before using at …

A Data-Driven Approach For Winter Precipitation Classification Using Weather Radar And Nwp Data, Bong Chul Seo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study describes a framework that provides qualitative weather information on winter precipitation types using a data-driven approach. The framework incorporates the data retrieved from weather radars and the numerical weather prediction (NWP) model to account for relevant precipitation microphysics. To enable multimodel-based ensemble classification, we selected six supervised machine learning models: k-nearest neighbors, logistic regression, support vector machine, decision tree, random forest, and multi-layer perceptron. Our model training and cross-validation results based on Monte Carlo Simulation (MCS) showed that all the models performed better than our baseline method, which applies two thresholds (surface temperature and atmospheric layer thickness) for …

Utility Of Vertically Integrated Liquid Water Content For Radar-Rainfall Estimation: Quality Control And Precipitation Type Classification, Bong Chul Seo, Witold F. Krajewski, Youcun Qi

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study proposes a new estimation method for vertically integrated liquid water content (VIL) using radar reflectivity volume data and temperature sounding retrieved from the numerical weather model analysis. This method addresses uncertainty factors in conventional VIL estimation associated with the effects from the bright band (BB) and radar beam geometry near the radar site. The new VIL is then used for precipitation classification (convective/stratiform) and wind turbine clutter detection in the hope that the estimated VIL indicating vertical activities or development of precipitation systems will account for the two independent subjects together, in opposite ways. The non-precipitation radar echoes …

Relationship Between Sunspot Numbers And Mean Annual Precipitation: Application Of Cross-Wavelet Transform—A Case Study, Mohammad Nazari-Sharabian, Moses Karakouzian

Civil and Environmental Engineering and Construction Faculty Research

Observations show that the Sun, which is the primary source of energy for the Earth’s climate system, is a variable star. In order to understand the influence of solar variability on the Earth’s climate, knowledge of solar variability and solar–terrestrial interactions is required. Knowledge of the Sun’s cyclic behavior can be used for future prediction purposes on Earth. In this study, the possible connection between sunspot numbers (SSN) as a proxy for the 11-year solar cycle and mean annual precipitation (MAP) in Iran were investigated, with the motivation of contributing to the controversial issue of the relationship between SSN and …

Sediment Yield In Salmon Creek After Decommissioning Logging Roads, Northern Humboldt County, California, Malia S B Gonzales

Cal Poly Humboldt theses and projects

Salmon Creek watershed is located in the Headwaters Forest Reserve in northern California and is known for the ecological value of its old-growth redwood forest, high biodiversity, and sensitive habitat for endangered species. The Bureau of Land Management primarily manages the Reserve. The land-use history of the Upper Salmon Creek watershed includes extensive timber harvest and road development. Watershed restoration in the Upper Salmon Creek watershed started in 2000 with the primary goal for the Reserve to protect and recover ecologic diversity and threatened native species. Since then, of the 23 miles, 13.5 miles of logging roads and 101 stream …

Thermodynamic Simulation Of Carbonitride Precipitation In Micro-Alloyed Steel, Weigang Li, Yang Wei, Liu Chao, Baokang Yan

Journal of System Simulation

Abstract: A mathematical model for calculating the precipitation of carbonitride in the process of hot rolling of composite micro-alloyed steel is established, and the interaction between the carbonitride and AlN is considered. In view of the difficulties of the thermodynamic model that the variables are multiple, the equations are nonlinear and the boundary conditions are determined difficultly, the Newton-Raphson numerical algorithm characterized by coupled problem is adopted. The precipitation starting temperature and precipitation sequence of carbonitride and AlN at different compositions are determined. The equilibrium composition of elements in austenite, the composition and mass fraction of carbonitride precipitates, as well …

Comparative Assessment Of Downscaling Methods And Application Towards Analysis Of Climate Change Impact On Urban Regions, Markus Eichenbaum

Electronic Thesis and Dissertation Repository

Global climate models (GCM) are sophisticated numerical models used to make long term climate projections. However, the resolution of their output is too coarse for climate change related local impact studies on urban regional scales. Downscaling efforts are taken to address this and increase GCM projection resolution. Physical Scaling (SP) downscaling methodology attempts to incorporate the physical basis of dynamical downscaling efforts with the computational efficiency of statistical methods. In this study, North American Regional Reanalysis surface skin temperature and precipitation data for a 1°x1° region centered on Houston, TX are downscaled to a resolution of 500m via SP and …

Precipitation Trends Over The Indus Basin, Nir Krakauer, Tarendra Lakhankar, Ghulam Hussain Dars

Publications and Research

A large population relies on water input to the Indus basin, yet basinwide precipitation amounts and trends are not well quantified. Gridded precipitation data sets covering different time periods and based on either station observations, satellite remote sensing, or reanalysis were compared with available station observations and analyzed for basinwide precipitation trends. Compared to observations, some data sets tended to greatly underestimate precipitation, while others overestimate it. Additionally, the discrepancies between data set and station precipitation showed significant time trends in many cases, suggesting that the precipitation trends of those data sets were not consistent with station data. Among the …

Assessing The Origin Of Noise In The Precipitation Gauge Geonor T-200b, Jonah B. Basl, Scott Landolt, Justin Lentz

STAR Program Research Presentations

The Geonor T-200B is an all-weather precipitation gauge utilized by the Research Applications Laboratory (RAL) under the University Corporation for Atmospheric Research (UCAR) and the National Center for Atmospheric Research (NCAR). RAL has been dealing with a persistent issue of noise within the Geonor Devices during non-precipitation events. When there is not precipitation occurring, the data reading off the Geonor would be expected to be a constant value, as no precipitation is being collected. However, the device is producing unaccounted variation (noise) causing tremor like lines to appear in the data. The noise in the data is an issue for …

Next-Generation Rainfall Idf Curves For The Virginian Drainage Area Of Chesapeake Bay, Xixi Wang, Xiaomin Yang, Zhaoyi Cai

Civil & Environmental Engineering Faculty Publications

Probability-based intensity-duration-frequency IDF curves are needed but currently lacking for Department of Defense DoD to construct and manage its infrastructure in changing climate. The objectives of this project were to 1 develop an innovative approach for considering rainfall non-stationarity in developing such IDF curves and 2 apply this approach to the state of Virginia. In this regard, the observed data on 15-min rainfall at 57 gauges and the precipitations projected by twelve pairs of Regional Climate Model RCM and Global Circulation Model GCM were used. For a given gauge or watershed, in terms of fitting the empirical exceedance probabilities, a …

Utilization Of Remote Sensing Data For Estimation Of The Groundwater Storage Variation, Gaurang Mistry

UNLV Theses, Dissertations, Professional Papers, and Capstones

Groundwater is the most extracted raw material, with an average withdrawal rate of 982 km3 per year, where 70 percent of the total groundwater withdrawn is used for agriculture globally (Margat & van der Gun, 2013). With climate change and increased water demands in recent years, monitoring the changes in the groundwater storage is of the utmost importance. This thesis presents an analysis that determines the rates, trends, and directions where groundwater storage is going in Pakistan. It also correlates fluctuations in groundwater storage with variations in precipitation and agricultural productivity in the country. The overall objectives of this thesis …

Multi-Resolution Spatio-Temporal Change Analyses Of Hydro-Climatological Variables In Association With Large-Scale Oceanic-Atmospheric Climate Signals, Kazi Ali Tamaddun

UNLV Theses, Dissertations, Professional Papers, and Capstones

The primary objective of the work presented in this dissertation was to evaluate the change patterns, i.e., a gradual change known as the trend, and an abrupt change known as the shift, of multiple hydro-climatological variables, namely, streamflow, snow water equivalent (SWE), temperature, precipitation, and potential evapotranspiration (PET), in association with the large-scale oceanic-atmospheric climate signals. Moreover, both observed datasets and modeled simulations were used to evaluate such change patterns to assess the efficacy of the modeled datasets in emulating the observed trends and shifts under the influence of uncertainties and inconsistencies. A secondary objective of this study was to …

Future Changes Of Hydroclimatic Extremes In Western North America Using A Large Ensemble: The Role Of Internal Variability, Mohammad Hasan Mahmoudi

Electronic Thesis and Dissertation Repository

Increases in the intensity and frequency of extreme events in Western North America (WNA) can cause significant socioeconomic problems and threaten existing infrastructure. In this study we analyze the impacts of climate change on hydroclimatic extremes and assess the role of internal variability over WNA, which collectively drain an area of about 1 million km². We used gridded observations and downscaled precipitation, maximum and minimum temperature from seven General Circulation Models (GCMs) that participated in the Coupled Model Intercomparison Project Phase 5 (CMIP5) and a large ensemble of CanESM2 model simulations (CanESM2-LE; 50 members) for this analysis. Spatial …

1923 - Flow In California Streams, Bulletin No. 5, Appendix A, Report To The Legislature

Miscellaneous Documents and Reports

The legislature of 1921 appropriated $200,000 for an investigation of California's water resources by the State Department of Public Works, Division of Engineering and Irrigation. Accordingly, an engineering investigation was completed and a report on California's water resources transmitted to the legislature on January 1, 1923. The report addresses the geology, precipitation and run-off in California.

2006 - Salinas Valley Hydrologic Subareas, 4th Quarter Water Conditions

Monterey County Water Resources Agency Water Reports

This report covers the fourth quarter of Water Year 2005-2006 (WY06), July through September 2006. It provides a brief overview of water conditions in the Salinas River Basin with discussion on precipitation, reservoir storage, and ground water trends.

2010 - Salinas Valley Hydrologic Subareas, 4th Quarter Water Conditions

Monterey County Water Resources Agency Water Reports

This report covers the fourth quarter of Water Year 2009-2010 (WY10), July through September 2010. It provides a brief overview of water conditions in the Salinas River Basin with discussion on precipitation, reservoir storage, and ground water trends.