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Full-Text Articles in Physical Sciences and Mathematics

Global Change Factors On Ecosystem Invasibility, Raj Lal, Jeffrey Dukes, Michael J. Schuster, Nick G. Smith Oct 2013

Global Change Factors On Ecosystem Invasibility, Raj Lal, Jeffrey Dukes, Michael J. Schuster, Nick G. Smith

The Summer Undergraduate Research Fellowship (SURF) Symposium

Current climate and human-induced changes are projected to alter many regimes of ecosystem functioning. It is projected that invasive species, nonnative species that can be of great detriment to an ecosystem, will benefit under these conditions. The Prairie Invasion and Climate Experiment (PRICLE) studies the effects of two global change factors – N addition and altered precipitation – on invasive species success and the traits that are selected for in a mixed-grass prairie ecosystem. PRICLE is a two by two factorial design over three replications in a restored mixed-grass prairie ecosystem. The major findings from the community traits examination of …


Deep-Water Near-Bottom Turbulence In Lake Michigan: An Underwater Investigation, David J. Cannon, Cary Troy Oct 2013

Deep-Water Near-Bottom Turbulence In Lake Michigan: An Underwater Investigation, David J. Cannon, Cary Troy

The Summer Undergraduate Research Fellowship (SURF) Symposium

Motivated by a need to characterize near-bottom deep-water turbulence for an understanding of the filtration capabilities of invasive quagga mussels, an instrument tripod was deployed in Lake Michigan for six months in 60m of water to measure current velocities, with specific interest being paid to near-bottom (0.10 to 0.95 meters above bottom) velocities during the deployment. The deployment period (September 2012-April 2013) was characterized by very little stratification and a median temperature of about throughout the water column. A mean horizontal velocity of 3.6 cm/s with a standard deviation of 2 cm/s was also measured at 1 meter above the …


Characterization Of Fractures Subjected To Normal And Shear Stress, Min-Kwang Choi Oct 2013

Characterization Of Fractures Subjected To Normal And Shear Stress, Min-Kwang Choi

Open Access Dissertations

Results from a series of laboratory experiments to determine fracture specific stiffness, for a fracture subjected to shear and normal stress, are presented and analyzed. The experimental work focuses on the determination of relations between normal and shear fracture specific stiffness and between spatial distribution of fracture specific stiffness and fluid flow through the fracture

The ratio of shear to normal fracture specific stiffness is experimentally investigated on a fracture subjected to shear as well as normal stress. Synthetic fractures made of gypsum and lucite were prepared with different fracture surface conditions: either well-mated or non-mated. For well-mated fracture surfaces, …


Developing A Framework For Determining The Contribution Of Transportation Project To Sustainable Development, Karim Ahmed Abdel Warith Oct 2013

Developing A Framework For Determining The Contribution Of Transportation Project To Sustainable Development, Karim Ahmed Abdel Warith

Open Access Dissertations

In the past few years, stakeholders in the transportation industry have been concerned with sustainability. However, transportation decision makers have had difficulty incorporating sustainability into transportation infrastructure decisions. This is mainly attributed to the vagueness of the term. Incorporating sustainability into transportation decision making has been a desire put forth by engineers for that past 10 years. However, with no apparent method of defining sustainability, designers and decision makers have not been able to fulfill this desire.

This investigation attempts to define sustainability in a comprehensive and quantitative manner. The research proposes a new methodology that relies on the objective …


Cloud To Cloud Registration For 3d Point Data, Darion Shawn Grant Oct 2013

Cloud To Cloud Registration For 3d Point Data, Darion Shawn Grant

Open Access Dissertations

The vast potential of digital representation of objects by large collections of 3D points is being recognized on a global scale and has given rise to the popularity of point cloud data (PCD). 3D imaging sensors provide a means for quickly capturing dense and accurate geospatial information that represent the 3D geometry of objects in a digital environment. Due to spatial and temporal constraints, it is quite common that two or more sets of PCD are obtained to provide full 3D analysis. It is therefore quite essential that all the PCD are referenced to a homogeneous coordinate frame of reference. …


Using High-Resolution Weather Data To Improve Winter Weather Maintenance Operations, Michael Baldwin Mar 2013

Using High-Resolution Weather Data To Improve Winter Weather Maintenance Operations, Michael Baldwin

Purdue Road School

Substantial resources are required for winter maintenance operations. This presentation focuses on more accurate and precise weather information that can help reduce the uncertainty related to winter weather, resulting in improved decision-making and significant cost savings for winter operations.


Simulating Land Use Land Cover Change Using Data Mining And Machine Learning Algorithms, Amin Tayyebi Jan 2013

Simulating Land Use Land Cover Change Using Data Mining And Machine Learning Algorithms, Amin Tayyebi

Open Access Dissertations

The objectives of this dissertation are to: (1) review the breadth and depth of land use land cover (LUCC) issues that are being addressed by the land change science community by discussing how an existing model, Purdue's Land Transformation Model (LTM), has been used to better understand these very important issues; (2) summarize the current state-of-the-art in LUCC modeling in an attempt to provide a context for the advances in LUCC modeling presented here; (3) use a variety of statistical, data mining and machine learning algorithms to model single LUCC transitions in diverse regions of the world (e.g. United States …


An Evaluation Of Spatial Variability Of Water Stress Index Across The United States: Implications Of Supply And Demand In The East Vs The West, Jennifer Ann Roath Jan 2013

An Evaluation Of Spatial Variability Of Water Stress Index Across The United States: Implications Of Supply And Demand In The East Vs The West, Jennifer Ann Roath

Open Access Theses

In order to support both human and environmental needs, high quality fresh water must be available when and where it is required. As a metric for indicating unsustainable water usage, WSI is only useful when the values reflect accurate interactions between supply and demand; however, the complexity of temporal and spatial variability of available fresh water complicates the analysis of water stress.

The overall goal of this project was to investigate the spatial variability of water stress across the United States and the appropriate spatial scale for management decisions. To accomplish this, a national dataset describing spatial distribution and breakdown …