Digital Commons Network^™

Generalized Quasilinear Simulation Of Turbulent Channel Flow, Colleen B. Kellam

Doctoral Dissertations

Direct numerical simulation (DNS) of wall-bounded turbulent flows in physically relevant parameter regimes remains infeasible in many cases of practical interest. Accordingly, this work further establishes the generalized quasilinear (GQL) approximation, introduced by Marston et al. (Phys. Rev. Lett., 116, 2016), as a robust, accurate, and efficient alternative to existing simulation and modeling schemes by investigating its effectiveness as a tool for simulating turbulent channel flow. The GQL reduction is achieved by separating the flow variables into low and high modes via a spectral filter rather than by decomposition into a strict mean and fluctuations, as for the quasilinear (QL) …

I. The Binding Of Cu(Ii) And Zn(Ii) To Poly-N-Isopropylacrylamide And Its Effects On The Phase Transition And Ii. The Synthesis And Characterization Of Nickelalactones Chelated By P-N-P Pincer Ligands, Luke Aaron Fulton

Doctoral Dissertations

The responsive material poly-N-isopropylacrylamide phase-transitions from hydrophilic to hydrophobic conformations above 32 °C in aqueous media. Researchers have successfully tied that responsive behavior to other dissolved species such as pH, metal concentrations, and even glucose concentration. From our interests in developing sensor technologies we ascertained that direct interactions between metal ion and polymer had received little to no attention. Our investigations into this literature gap discovered that dissolved metal ion only slightly shifts the lower critical solution temperature. However, metal ion greatly increases the size of polymer aggregates, and is found to bind directly to the polymer. We present a …

Fatigue Assessment Of Complex Structural Components Of Steel Bridges Integrating Finite Element Models And Field-Collected Data, Maryam Mashayekhizadeh

Doctoral Dissertations

Fatigue damage in welded structural steel components has a complex presentation, which is influenced by the geometric configuration of the component and load path in a structural system. The classic fatigue assessment methods, using nominal stresses and S-N curves, may not capture nor predict the complicated performance of the component with respect to fatigue. Recent novel complex steel structural connections that experience multi-axial behavior or do not fit any conventional fatigue categories are not explicitly addressed in the existing fatigue design codes. An ideal fatigue estimation for the complex structural components is dependent on a thorough understanding of structural performance …

Effects Of Waves, Tides, And Vegetation On The Distribution Of Bed Shear Stress In The Great Bay Estuary, Nh, Salme Cook

Doctoral Dissertations

The goals of this research are to expand our understanding of, and improve predictions of bed shear stress in estuarine environments using both observational datasets and numerical modeling. To accurately predict sediment transport, a good understanding of the bed shear stress that drives the sediment erosion, suspension and deposition is essential. Shear stress is a function of both the hydrodynamics in the system and the characteristics of the sediment that comprise the bed itself. The hydrodynamic forcing is determined by tides, waves, meteorological effects, rivers, or some combination that can change on time scales of a few minutes to a …

Agrobiodiversity For Pest Management: An Integrated Bioeconomic Simulation And Machine Learning Approach, Talha Siddique

Master's Theses and Capstones

A pressing challenge of modern agriculture is to develop means of decreasing the negative impacts of pesticides while maintaining low pest pressure and high crop yield. Certain crop varieties, especially wild relatives of domesticated crops, provide pest regulation ecosystem services through chemical defense mechanisms. Benefits from these ecosystem service can be realized by intercropping cash crops with repellent wild varieties to reduce pest pressure. An opportunity cost exists, however, which consists of lower yield and market value. Such is the case of heirloom apple varieties that are more resistant to the codling moth but have a lower market value compared …

An Adaptive Hilbert-Huang Transform System, Joshua Letterman

Master's Theses and Capstones

This thesis presents a system which can be used to generate Intrinsic Mode Functions and the associated Hilbert spectrum resulting from techniques based on the Empirical Mode Decomposition as pioneered by N. E. Huang at the end of the 20th century. Later dubbed the Hilbert-Huang Transform by NASA, the process of decomposing data manually through repetitive detrending and subtraction followed by applying the Hilbert transform to the results was presented as a viable alternative to the wavelet transform which was gaining traction at the time but had shown significant limitations. In the last 20 years, the Hilbert-Huang Transform has received …

Analysis Of Autoguiding For Exoplanet Transit Research At The Unh Observatory, Anthony Cappuccio

Honors Theses and Capstones

This paper will discuss the proper calibration technique for an autoguider of a CCD camera and the results that follow from successful exoplanet transit observations. A brief background on exoplanets, the transit method, and the analysis of their parent stars through photometry will be examined. The results will be presented in a before and after framework that will visually represent the data improvements from autoguiding as graphical Light Curves (LC). The addition of being able to autoguide at the UNH observatory will work towards providing future students with the possibility of performing follow-up ground-based observations and archiving their work online …

Deliberative Multiattribute Valuation Of Ecosystem Services Across A Range Of Regional Land-Use, Socioeconomic, And Climate Scenarios For The Upper Merrimack River Watershed, New Hampshire, Usa, Mark E. Borsuk, Georgia Mavrommati, Nihar R. Samal, Shantar Zuidema, Wil Wollheim, Shannon Rogers, Alexandra M. Thorn, David Lutz, Madeleine Mineau, Curt Grimm, Kevin Gardner

Faculty Publications

We evaluate the relative desirability of alternative futures for the upper Merrimack River watershed in New Hampshire, USA based on the value of ecosystem services at the end of the 21st century as gauged by its present-day inhabitants. This evaluation is accomplished by integrating land-use and socioeconomic scenarios, downscaled climate projections, biogeophysical simulation models, and the results of a citizen-stakeholder deliberative multicriteria evaluation. We find that although there are some trade-offs between alternative plausible futures, for the most part, it can be expected that future inhabitants of the watershed will be most satisfied if land-use planning in the intervening years …

Connecting Composting And Greenhouses: An Energy Capture And Usage Model, Dena M. Hoffman

Honors Theses and Capstones

At the Organic Dairy Research Farm in Lee, New Hampshire, the practice of aerated static composting is researched for potential heat capture. In early 2019, an Excel model was created to illustrate the ability of greenhouses to retain heat during a cold month of January and the total energy balance for each day. This model shows that an average greenhouse, based on the dimensions of the greenhouse at Kingman Farm, requires an additional, external heat source to supplement its heating needs. By adding the heat generated by the aerated static composting pile to the greenhouse in the Excel model, the …

Improving Photometry And Astrophotography By Eliminating Dark Frames And Flat Fields, Tom C. Ireland

Honors Theses and Capstones

I report on the efforts to improve the dark frames and flat fielding procedure for the charged-coupled device (CCD) camera for the Celestron C14 telescope at the UNH observatory. Dark frames are images taken while the shutter of the camera is closed so that only electronic and dark noise and other internal inconsistencies are recorded. These are important because they allow astronomers to subtract out interference from dark current. Additionally, flat fields are images of the entire field of the telescope so that the brightness in the pixels of the telescope’s field of view is uniform. Flat fields are vital …

Normalization Of Leadville Neutron Monitor To Climax Neutron Monitor, Brian J. O'Connor

Honors Theses and Capstones

No abstract provided.

Predicting The Outcome Of Nfl Games Using Logistic Regression, Stephen Bouzianis

Honors Theses and Capstones

No abstract provided.

The Role Of Small Reservoirs In Reducing Reactive N Export Via Denitrification, Margaret Phillips, Wil Wollheim

Honors Theses and Capstones

Reactive nitrogen (N), which harms ecosystem health, has been increasing in the biosphere, leading to higher N export to coastal ecosystems. Although man-made reservoirs can be significant sources of greenhouse gases, they can also retain N, thus reducing N export. Because many dams are relics from industrial hydropower, their removal is becoming increasingly common. It is therefore crucial to understand the ecological tradeoffs of man-made reservoirs. While previous studies have examined nutrient budgets and denitrification at inputs and outputs of large reservoirs, small reservoir dynamics remain understudied. In this study, we measured inputs and outputs of NO₃ and N …

Clarifying The Interpretation Of Carbon Use Efficiency In Soil Through Methods Comparison, Kevin M. Geyer, Paul Dijkstra, Robert Sinsabaugh, Serita D. Frey

Faculty Publications

Accurate estimates of microbial carbon use efficiency (CUE) are required to predict how global change will impact microbially-mediated ecosystem functions such as organic matter decomposition. Multiple approaches are currently used to quantify CUE but the extent to which estimates reflect methodological variability is unknown. This limits our ability to apply or cross-compare published CUE values. Here we evaluated the performance of five methods in a single soil under standard conditions. The microbial response to three substrate amendment rates (0.0, 0.05, and 2.0 mg glucose-C g−1 soil) was examined using: 13C and 18O isotope tracing approaches which estimate CUE based on …

Unh Professor Named National Academy Of Inventors Fellow, Erika Mantz

Media Relations

No abstract provided.

Fellow Of Invention, Beth Potier

UNH Today Archive

No abstract provided.

Strain Path Sensitive Polycrystal Plasticity Constitutive Models Within Finite Elements For Metal Forming Simulations, Milovan Zecevic

Doctoral Dissertations

An optimal sheet metal forming process shapes a metal part to the accurate geometry, while avoiding instabilities causing localization of deformation and fracture. Understanding the underlying mechanisms responsible for deformation localization and deviation of final part geometry from the desired geometry facilitates the search for the optimal sheet metal forming process. Accurate modeling of forming processes allows prediction of the formed part shape and can provide insight into the material behavior by interpretation of experimental measurements and prediction of variables not accessible to experimental characterization. In this work, a micromechanical material model is coupled with finite elements to create a …

A Combined Model Of Statistical Downscaling And Latent Process Multivariable Spatial Modeling Of Precipitation Extremes, Meng Zhao

Doctoral Dissertations

Future projections of extreme precipitation can help engineers and scientists with infrastructure design projects and risk assessment studies. Extreme events are usually represented as return levels which are equivalent to upper percentiles of an extreme value distribution, such as the Generalized Pareto distribution, which is used for exceedances above a certain threshold.

My dissertation focus is on uncertainty quantification related to estimation of future return levels for precipitation at the local (weather station) to regional level. Variance reduction is achieved through spatial modeling and optimally combining suites of climate model outputs. The main contribution is a unified statistical model that …

Occupancy Detection Using Wireless Sensor Network In Indoor Environment, Farah Ferdaus

Master's Theses and Capstones

Occupancy detection plays an important role in many smart buildings such as reducing building energy usage by controlling heating, ventilation and air conditioning (HVAC) systems, monitoring systems and managing lighting systems, tracking people in hospitals for medical issues, advertising to people in malls, and to search and rescue missions. The global positioning system (GPS) is used most widely as a localization system but highly inaccurate for indoor applications. The indoor environment is difficult to handle because along with the loss of signals, privacy is a major concern. Indoor tracking has many aspects in common with sensor localization in Wireless Sensor …

Classification Of Arbitrary Motion Into A Canonical Basis, Michael Moger

Master's Theses and Capstones

The Empatica E4 wristwatch utilizes four sensors to capture medical data from its user - an accelerometer, a plethysmograph, an electro-dermal activity sensor, and an infrared thermophile. Utilizing these sensors, the device can provide detection-based feedback for patients suffering from various ailments. However, each sensor is coupled with the other readings, so any raw data will have a degree of noise accompanying the actual signal. After detailing a conceptual and programming knowledge of various industry-standard data processing techniques, we follow the appropriate steps to take in order to clean up a noisy E4 data signal, starting with supervised basis signals …

A Protocol For Using Long-Term Structural Health Monitoring Data To Detect And Localize Damage In Bridges, Kathryn Elaine Kaspar

Master's Theses and Capstones

The purpose of this research is to establish a protocol for using strain gauge data to characterize the undamaged state of a bridge for structural health monitoring. The Powder Mill Bridge (PMB), which has been instrumented with strain gauges since its opening in 2009, is used as a case study. and the strain gauges used in this study are located at 27 different locations throughout the bridge. Artificial neural networks (ANNs) and linear regression are presented as methodologies for characterizing the relationship between the strains at each of the stations on the bridge. One linear regression analysis was performed as …

Experimental Evaluation Of Fatigue Test Setup For A Gusset-Less Truss Connection, Duncan William Mcgeehan

Master's Theses and Capstones

In 2013, the newly designed Memorial bridge, located between Portsmouth, NH, and Kittery, ME, was opened to traffic. The structural system of the bridge is composed of truss elements with a unique “Gusset-less” connection which utilizes curved steel to transition from the chords to the diagonals where splice plates join the members. With such a unique connection, it is important to verify the design assumptions and assess the performance. In this study, the fatigue performance of the Gusset-less connection is investigated through an experimental fatigue test of a scale model of the connection.

In a high-cycle fatigue test, it is …

A Simplified Structural Analysis Method For A 20-Foot Cargo Shipping Container, Dzijeme Ntumi

Master's Theses and Capstones

Cargo containers are utilized around the globe as structural components in the design of buildings. Kevin Giriuanas [1] wrote a thesis on the finite element analysis of a 20-foot cargo shipping container, which was comprised of mostly shell elements. This thesis aims to develop a simplified beam model which compares well with the displacement and stresses of a finite element shell model of a 20-foot cargo shipping container. The simplified beam model is comprised of columns with rectangular cross sections and four panels developed using the modified box frame model presented in a thesis by Deborah L. Calvin [2]. The …

Dynamic Duo, Beth Fornauf

UNH Today Archive

No abstract provided.

Reduced Carbon Use Efficiency And Increased Microbial Turnover With Soil Warming, Jianwei Li, Gangsheng Wang, Melanie A. Mayes, Steven D. Allison, Serita D. Frey, Zheng Shi, Xiao-Ming Hu, Yiqi Luo, Jerry M. Melillo

Faculty Publications

Global soil carbon (C) stocks are expected to decline with warming, and changes in microbial processes are key to this projection. However, warming responses of critical microbial parameters such as carbon use efficiency (CUE) and biomass turnover (rB) are not well understood. Here, we determine these parameters using a probabilistic inversion approach that integrates a microbial-enzyme model with 22 years of carbon cycling measurements at Harvard Forest. We find that increasing temperature reduces CUE but increases rB, and that two decades of soil warming increases the temperature sensitivities of CUE and rB. These temperature sensitivities, which are derived from decades-long …

Swing Time, Unh Communications And Public Affairs

UNH Today Archive

No abstract provided.

Unh Energy Task Force: 2017 Annual Report, Unh Energy Task Force

The Sustainability Institute Publications

The Energy Task Force (ETF) at the University of New Hampshire (UNH) was established in 2005 and is comprised of staff, faculty, and students. The ETF serves in an advisory capacity to the UNH President and makes recommendations on the full range of issues related to climate change and energy.

The fiscal year 2017 was a watershed year for the UNH and our commitment to renewable energy. Our greenhouse gas footprint is down 51% from the 2001 baseline and our electricity is now 100% powered by renewables. The University’s greenhouse gas emissions based on the number of students and gross …

Listening To Bubbles, Beth Potier

UNH Today Archive

No abstract provided.

Unh-Led Initiative Advances State’S Biomaterials Industry, Erika Mantz

UNH Today Archive

No abstract provided.

Guidelines And Considerations For Designing Field Experiments Simulating Precipitation Extremes In Forest Ecosystems, Heidi Asbjornsen, John L. Campbell, Katie A. Jennings, Matthew A. Vadeboncoeur, Cameron Mcintire, Pamela H. Templer, Richard P. Phillips, Taryn L. Bauerle, Michael C. Dietze, Serita D. Frey, Peter M. Groffman, Rosella Guerrieri, Paul J. Hanson, Eric P. Kelsey, Alan K. Knapp, Nathan G. Mcdowell, Patrick Meir, Kimberly A. Novick, Scott V. Ollinger, Will T. Pockman, Paul G. Schaberg, Stan D. Wullschleger, Melinda D. Smith, Lindsey E. Rustad

Faculty Publications

Precipitation regimes are changing in response to climate change, yet understanding of how forest ecosystems respond to extreme droughts and pluvials remains incomplete. As future precipitation extremes will likely fall outside the range of historical variability, precipitation manipulation experiments (PMEs) are critical to advancing knowledge about potential ecosystem responses. However, few PMEs have been conducted in forests compared to short-statured ecosystems, and forest PMEs have unique design requirements and constraints. Moreover, past forest PMEs have lacked coordination, limiting cross-site comparisons. Here, we review and synthesize approaches, challenges, and opportunities for conducting PMEs in forests, with the goal of guiding design …