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An Investigation Of Design Alternatives For 328-Ft (100-M) Tall Wind Turbine Towers, Thomas James Lewin 2010 Iowa State University

An Investigation Of Design Alternatives For 328-Ft (100-M) Tall Wind Turbine Towers, Thomas James Lewin

Graduate Theses and Dissertations

As wind turbines are continued to be placed at higher elevations, the need for taller wind turbine towers becomes necessary. However, there are multiple challenges associated with extending the currently used 262-ft (80-m) tall tubular steel towers to greater elevations. In this context, alternative tower designs and/or construction materials, including the use of concrete and Ultra-High Performance Concrete (UHPC), are explored for a wind turbine tower with a 328-ft (100-m) hub height. Given the lack of existing documents for designing wind turbine towers, the current design practice for wind turbine towers and applicable design code of practice are examined ...


Center For Coastal Resources Management Annual Report 2010, Center for Coastal Resources Management, Virginia Institute of Marine Science 2010 College of William and Mary

Center For Coastal Resources Management Annual Report 2010, Center For Coastal Resources Management, Virginia Institute Of Marine Science

Reports

No abstract provided.


Design And Synthesis Of Mixed Oxides Nanoparticles For Biofuel Applications, Senniang Chen 2010 Iowa State University

Design And Synthesis Of Mixed Oxides Nanoparticles For Biofuel Applications, Senniang Chen

Graduate Theses and Dissertations

The work in this dissertation presents the synthesis of two mixed metal oxides for biofuel applications and NMR characterization of silica materials. In the chapter 2, high catalytic efficiency of calcium silicate is synthesized for transesterfication of soybean oil to biodisels. Chapter 3 describes the synthesis of a new Rh based catalyst on mesoporous manganese oxides. The new catalyst is found to have higher activity and selectivity towards ethanol. Chapter 4 demonstrates the applications of solid state Si NMR in the silica materials.


Fairfax County And The City Of Alexandria, Virginia Shoreline Inventory Report Methods And Guidelines, Marcia Berman, Harry Berquist, Sharon Killeen, Carl Hershner, Karinna Nunez, Karen Reay, Tamia Rudnicky 2010 Virginia Institute of Marine Science

Fairfax County And The City Of Alexandria, Virginia Shoreline Inventory Report Methods And Guidelines, Marcia Berman, Harry Berquist, Sharon Killeen, Carl Hershner, Karinna Nunez, Karen Reay, Tamia Rudnicky

Reports

The data inventory developed for the Shoreline Inventory is based on a three‑tiered shoreline assessment approach. In most cases this assessment characterizes conditions that can be observed from a small boat navigating along the shoreline. The three tiered shoreline assessment approach divides the shorezone into three regions: 1) the immediate riparian zone, evaluated for land use; 2) the bank, evaluated for height, stability, cover and natural protection; and 3) the shoreline, describing the presence of shoreline structures for shore protection and recreational purposes. Hand-held GPS units are used to log features observed in the field.

Three GIS coverages are ...


Transmitter Optimization In Multiuser Wireless Systems With Quality Of Service Constraints, Danda B. Rawat 2010 Old Dominion University

Transmitter Optimization In Multiuser Wireless Systems With Quality Of Service Constraints, Danda B. Rawat

Electrical & Computer Engineering Theses & Disssertations

In this dissertation, transmitter adaptation for optimal resource allocation in wireless communication systems are investigated. First, a multiple access channel model is considered where many transmitters communicate with a single receiver. This scenario is a basic component of a. wireless network in which multiple users simultaneously access the resources of a wireless service provider. Adaptive algorithms for transmitter optimization to meet Quality-of-Service (QoS) requirements in a distributed manner are studied. Second, an interference channel model is considered where multiple interfering transmitter-receiver pairs co-exist such that a given transmitter communicates with its intended receiver in the presence of interference from other ...


Synthesis And Structural, Magnetic, Thermal, And Transport Properties Of Several Transition Metal Oxides And Arsenides, Supriyo Das 2010 Iowa State University

Synthesis And Structural, Magnetic, Thermal, And Transport Properties Of Several Transition Metal Oxides And Arsenides, Supriyo Das

Graduate Theses and Dissertations

Several transition metal oxides and arsenides have been synthesized and their magnetic, thermal, structural, and transport properties have been studied in this thesis. Magnetically pure spinel compound LiV2O4 is a rare d-electron heavy fermion. The presence of small concentrations of magnetic defects, which are produced by the crystal defects in the spinel structure, strongly affect the physical properties of LiV2O4. The phase relations in the Li2O-V2O3-V2O5 ternary system at 700 °C for compositions in equilibrium with LiV2O4 are reported. This study clarified ...


Searchtree: Mining Robust Phylogenetic Trees, Akshay Deepak 2010 Iowa State University

Searchtree: Mining Robust Phylogenetic Trees, Akshay Deepak

Graduate Theses and Dissertations

Phylogenetic trees providing high quality information and at the same time covering large number of species are essential for comparative biology. It is a widely accepted fact that with the currently available resources we are far from assembling one completely sampled phylogenetic tree for all life (or one based on a very large subset of species), hence a need for an interim solution arises. Here we describe SearchTree, a software tool that allows users to query efficiently on an arbitrary user taxon list and returns high scoring matches from approximately one billion phylogenetic trees being constructed from molecular sequence data ...


Geometrical Structure And Analysis Of Association Rule, Rajat Sar 2010 San Jose State University

Geometrical Structure And Analysis Of Association Rule, Rajat Sar

Master's Projects

Association rule mining helps us to identify the association between items from a large transactional data set. It has always been a time consuming process because of repeatedly scanning of the data set. Apriori Algorithm [1] and FP-Tree Algorithm [2] are the two methods to find out the association of items in a large transactional item set. Both the above algorithm works differently (Apriori follows Bottom-Up Approach & FP-Tree follows Top-Down Approach) in order to get the association. Associations of items generated from the above two algorithms can be represented in geometry. The geometrical form of associations is called Simplical Complex ...


Approximate Disassembly, Dhivyakrishnan Radhakrishnan 2010 San Jose State University

Approximate Disassembly, Dhivyakrishnan Radhakrishnan

Master's Projects

For the past two decades, computer viruses have been a constant security threat. A computer virus is a type of malware that may damage computer systems by destroying data, crashing the system, or through other malicious activity. Among the different types of viruses, metamorphic viruses are one of the most difficult to detect since such viruses change their internal structures with each mutation, making signature-based detection infeasible. Many construction kits are available that can be used to easily generate metamorphic strains of any given virus. Previous work has shown that metamorphic viruses are detectable using Hidden Markov Models (HMM). In ...


Statistical Methods For Analyzing Physical Activity Data, Nicholas Koenen Beyler 2010 Iowa State University

Statistical Methods For Analyzing Physical Activity Data, Nicholas Koenen Beyler

Graduate Theses and Dissertations

Physical activity is any bodily movement that results in caloric expenditure. One important aspect of physical activity research is the assessment of usual (i.e., long-term average) physical activity in the population, in order to better understand the links between physical activity and health outcomes. Daily or weekly measurements of physical activity taken from a sample of indivuals are prone to measurement errors and nuisance effects, which can lead to biased estimates of usual physical activity parameters. Fortunately, statistical models can be used to account and adjust for these errors in order to give more accurate estimates of usual physical ...


New Synthetic Methods For Biologically Active Aromatic Heterocycles, Vinayak Gupta 2010 Iowa State University

New Synthetic Methods For Biologically Active Aromatic Heterocycles, Vinayak Gupta

Graduate Theses and Dissertations

First part of this work details the use of phosphazene base P4t–Bu mediated cyclodehydration towards the synthesis of heterocycles like 5,6–dihydroindolo[2,1–a]isoquinolines and 2,3–diarylbenzo[b]furans. This work also report the use of P4t–Bu for the total syntheses of O–methylcryptaustoline iodide and amurensin H. Both total syntheses feature P4t–Bu mediated cyclodehydration as the key steps towards the completion of the syntheses.

The second part of this work is dedicated towards the synthetic efforts to develop pyrido[2,3–d]pyrimidines as effective abelson ...


Survival Of Grasshopper Sparrows (Ammodramus Savannarum) During Two Important Life Stages In Grassland Managed With Fire And Grazing, Torre James Hovick 2010 Iowa State University

Survival Of Grasshopper Sparrows (Ammodramus Savannarum) During Two Important Life Stages In Grassland Managed With Fire And Grazing, Torre James Hovick

Graduate Theses and Dissertations

Patch-burn grazing (PBG) is a management practice intended to benefit grassland-dependent wildlife. This practice relies on a fire-grazing interaction to create a habitat mosaic that is heterogeneous in terms of structure and composition, mimicking historic conditions. To assess effects of this, we studied nesting and postfledging survival of Grasshopper Sparrows (Ammodramus savannarum), in pastures under two treatments: PBG (grazed, 1/3 burned annually) or graze-and-burned (grazed, entire pasture burned every third year).The study was conducted in Ringgold County, Iowa, on public and private lands. We found 332 Grasshopper Sparrow nests in 2008 and 2009. In 2009 we attached 50 ...


A New Routing Metric For Wireless Mesh Networks, Vineeth Kisara 2010 Iowa State University

A New Routing Metric For Wireless Mesh Networks, Vineeth Kisara

Graduate Theses and Dissertations

In Wireless Mesh Networks the main goal is to achieve the best possible quality and efficiency of data transmission between source and destination nodes. To achieve such transmission, a routing algorithm should select better paths by taking the quality of wireless links into account. Simple path selection based on minimal hop count often leads to poor performance due to the fact that paths with low hop count often have higher packet loss rates. Better paths can be obtained by characterizing the actual quality of wireless link. A number of link quality aware routing metrics such as Expected Transmission Count (ETX ...


Development And Application Of Qm/Mm Methods To Study The Solvation Effects And Surfaces, Pooja Arora 2010 Iowa State University

Development And Application Of Qm/Mm Methods To Study The Solvation Effects And Surfaces, Pooja Arora

Graduate Theses and Dissertations

The dissertation consists of the development and application of QM/MM methods to study the solvation effects and surfaces. The dissertation illustrates the methodology of the interface of the EFP method with the configuration interaction with single excitations (CIS) method to study solvent effects in excited states. The solvation effects have been studied on the adiabatic electron affinity of the hydroxyl radical in aqueous solution and in micro-solvated clusters using a QM/EFP method. A hybrid QM/MM embedded cluster model (SIMOMM) has been implemented to study the etching and diffusion of atomic oxygen on a reconstructed Si(100)-2X1 ...


Synthesis Of Chrysosplenol B, Chrysosplenol D, And Their Analogs And Synthesis Of 3-(Carboxymethylthio)-Picolinic Acid And Its Analog, Joyce Yoosun Kang 2010 Iowa State University

Synthesis Of Chrysosplenol B, Chrysosplenol D, And Their Analogs And Synthesis Of 3-(Carboxymethylthio)-Picolinic Acid And Its Analog, Joyce Yoosun Kang

Graduate Theses and Dissertations

Synthesis of natural products or their analogs is interesting and challenging work. During the course of the investigation, chemists can not only prepare various kinds of bioactive compounds, but also discover new synthetic methodologies. The first chapter of this thesis deals with the development of modified methods to synthesize chrysosplenol B, chrysosplenol D, and their analogs. Both chrysosplenol B and chrysosplenol D have the flavone skeleton with 3-methoxyl and 5-hydroxyl groups. They have ability to potentiate the potent anti-malarial activity of artemisinin and have ability to potentiate the activity of norfloxacin. The second chapter deals with the synthetic effort towards ...


Detecting Recombination And Its Mechanistic Association With Genomic Features Via Statistical Models, Misha Rajaram 2010 Iowa State University

Detecting Recombination And Its Mechanistic Association With Genomic Features Via Statistical Models, Misha Rajaram

Graduate Theses and Dissertations

Recombination is a powerful weapon in the evolutionary arsenal of retroviruses such as HIV. It enables the production of chimeric variants or recombinants that may confer a selective advantage to the pathogen over the host immune response. Recombinants further accentuate differences in virulence, disease progression and drug resistance mutation patterns already observed in non-recombinant variants of HIV. This thesis describes the development of a rapid genotyper for HIV sequences employing supervised learning algorithms and its application to complex HIV recombinant data, the application of a hierarchical model for detection of recombination hotspots in the HIV-1 genome and the extension of ...


Improving Statistical Inference For Gene Expression Profiling Data By Borrowing Information, Long Qu 2010 Iowa State University

Improving Statistical Inference For Gene Expression Profiling Data By Borrowing Information, Long Qu

Graduate Theses and Dissertations

Gene expression profiling experiments, in particular, microarray experiments, are popular in genomics research. However, in addition to the great opportunities provided by such experiments, statistical challenges also arise in the analysis of expression profiling data. The current thesis discusses statistical issues associated with gene expression profiling experiments and develops new statistical methods to tackle some of these problems.

In Chapter 2, we consider the insufficient sample size problem in detecting differential gene expression. We address the problem by developing and evaluating methods for variance model selection. The idea is that information about error variances might be learned from related datasets ...


On Hopf Algebras Of Dimension 4p, Yi-lin Cheng 2010 Iowa State University

On Hopf Algebras Of Dimension 4p, Yi-Lin Cheng

Graduate Theses and Dissertations

Some progress on classification problems for finite dimensional Hopf algebras has been made recently. In this thesis, we look at 4p-dimensional Hopf algebras over an algebraically closed field of characteristic zero. We show that a non-semisimple Hopf algebra of dimension 4p with an odd prime p is pointed if, and only if, this Hopf algebra contains more than two group-like elements. Moreover, we prove that non-semisimple Hopf algebras of dimensions 20, 28 and 44 are either pointed or dual-pointed, and this completes the classification of Hopf algebras of dimension 20, 28,and 44.


Investigations Of The Mechanism Of Retention Of Electrochemically Modulated Liquid Chromatography, Gloria Fe Pimienta 2010 Iowa State University

Investigations Of The Mechanism Of Retention Of Electrochemically Modulated Liquid Chromatography, Gloria Fe Pimienta

Graduate Theses and Dissertations

Electrochemically modulated liquid chromatography is a technique which uses a column that is configured as a three-electrode electrochemical cell. The packing is a conductive material, serving both as a stationary phase and as a working electrode. Chromatographic retention is manipulated through changes in the potential applied to the stationary phase (Eapp) which alters interfacial properties such as surface charge and double layer structure. The stationary phase can thus be viewed as a compositionally tunable packing, with retention properties that can be adjusted to enhance separation efficiency. EMLC separations have been carried out to a wide variety of analyte mixtures ...


An Option-Theoretic Valuation Model For Residential Mortgages With Stochastic Conditions And Discount Factors, Fernando Miranda-mendoza 2010 Iowa State University

An Option-Theoretic Valuation Model For Residential Mortgages With Stochastic Conditions And Discount Factors, Fernando Miranda-Mendoza

Graduate Theses and Dissertations

Standard mathematical mortgage valuation models consist of three components: the future promised payments, the financial option to default, and the financial option to prepay. In this thesis we propose and analyze new concepts introduced into the standard models. The new concepts include discount factors, coherent boundary conditions, and stochastic terms. In this framework, the value of a mortgage satisfies a Black-Scholes type stochastic PDE. The approximate solution to our model involves a numerical method based on the Wiener-Ito chaos expansion, which breaks the stochastic PDE into a sequence of deterministic PDEs. These PDEs involve a free boundary, are discretized by ...


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