Digital Commons Network^™

Permafrost And Climate Change: Carbon Cycle Feedbacks From The Warming Arctic, Edward A. G. Schuur, Benjamin W. Abbott, Roisin Commane, Jessica G. Ernakovich, Eugenie Euskirchen, Gustaf Hugelius, Guido Grosse, Miriam Jones, Charlie Koven, Victor Leshyk, David Lawrence, Michael M. Loranty, Marguerite Mauritz, David Olefeldt, Susan Natali, Heidi Rodenhizer, Verity Salmon, Christina Schadel, Jens Strauss, Claire C. Treat, Merritt Turetsky

Faculty Publications

Rapid Arctic environmental change affects the entire Earth system as thawing permafrost ecosystems release greenhouse gases to the atmosphere. Understanding how much permafrost carbon will be released, over what time frame, and what the relative emissions of carbon dioxide and methane will be is key for understanding the impact on global climate. In addition, the response of vegetation in a warming climate has the potential to offset at least some of the accelerating feedback to the climate from permafrost carbon. Temperature, organic carbon, and ground ice are key regulators for determining the impact of permafrost ecosystems on the global carbon …

Vyas To Lead Beauregard Center, Unh Communications And Public Affairs

UNH Today Archive

No abstract provided.

Investigating Racial And Ethnic Disparities In The Provision Of Workplace Accommodations In The United States, Debra L. Brucker, Megan Henly, Andrew J. Houtenville

Institute on Disability

This study used data from a nationally representative survey that follows people 50 and older over time (the Health and Retirement Study) to test whether the receipt of workplace accommodations by persons with work limitations varies by race/ethnicity. Workplace accommodations can include changes to time (allowing more breaks, allowing different arrival or departure times, or shortening the workday), provision of equipment/assistance (getting someone to help, getting special equipment, arranging special transportation), and changes to work (changing the job, helping to learn new job skills). We found that 85% of persons with work limitations identified a need for workplace accommodations, but …

Do We Really Know What Is In Our Food? The Connection Between Dietary Mycotoxin Exposure And Pediatric Crohn’S Disease, Susan L. Gonya

Master's Theses and Capstones

AbstractBACKGROUND: The incidence of pediatric Crohn’s disease (CD) has increased over the past few decades. The etiology of CD has not yet been elucidated. Still, researchers have identified variables associated with the disease process, including genetic predisposition, environmental triggers like a poor-quality diet, air pollution, water pollution, and a dysbiotic microbiome with increased fungal diversity as predisposing factors. Fungal mycotoxin contamination in the food supply from toxicants like Deoxynivalenol (DON), a highly prevalent gastrointestinal irritant, has largely been ignored as a potential factor influencing the fungal dysbiosis and symptoms associated with the disease process. It is hypothesized that global and …

Adsorption Of Helium And Hydrogen On Triphenylene And 1,3,5-Triphenylbenzene, Bergmeister Bergmeister, Kollotzek Kollotzek, Florent Calvo, Elisabeth Gruber, Fabio Zappa, Paul Scheier, Olof E. Echt

Faculty Publications

The adsorption of helium or hydrogen on cationic triphenylene (TPL, C₁₈H₁₂), a planar polycyclic aromatic hydrocarbon (PAH) molecule, and of helium on cationic 1,3,5-triphenylbenzene (TPB, C₂₄H₁₈), a propeller-shaped PAH, is studied by a combination of high-resolution mass spectrometry and classical and quantum computational methods. Mass spectra indicate that He_nTPL⁺ complexes are particularly stable if n = 2 or 6, in good agreement with the quantum calculations which show that for these sizes the helium atoms are strongly localized on either side of the central carbon ring for n = …

Microtopography Matters: Belowground Ch4 Cycling Regulated By Differing Microbial Processes In Peatland Hummocks And Lawns, Clarice R. Perryman, Carmody K. Mccalley, Jessica G. Ernakovich, Louis J. Lamit, Joanne H. Shorter, Erik Lilleskov, Ruth K. Varner

Faculty Publications

Water table depth and vegetation are key controls of methane (CH4) emissions from peatlands. Microtopography integrates these factors into features called microforms. Microforms often differ in CH4 emissions, but microform-dependent patterns of belowground CH4 cycling remain less clearly resolved. To investigate the impact of microtopography on belowground CH4 cycling, we characterized depth profiles of the community composition and activity of CH4-cycling microbes using 16S rRNA amplicon sequencing, incubations, and measurements of porewater CH4 concentration and isotopic composition from hummocks and lawns at Sallie's Fen in NH, USA. Geochemical proxies of methanogenesis and methanotrophy indicated that microforms differ in dominant microbial …

Office Of Research, Economic Engagement And Outreach Update, July 13, 2022, Office Of Research, Economic Engagement And Outreach

Office of Research, Economic Engagement and Outreach

No abstract provided.

Career Builders, Beth Potier

UNH Today Archive

No abstract provided.

We Must Stop Fossil Fuel Emissions To Protect Permafrost Ecosystems, Benjamin W. Abbott, Michael Brown, Joanna C. Carey, Jessica G. Ernakovich, Jennifer M. Frederick, Laodong Guo, Gustaf Hugelius, Raymond M. Lee, Michael M. Loranty, Robie Macdonald, Paul J. Mann, Susan M. Natali, David Olefeldt, Pam Pearson, Abigail Rec, Martin Robards, Verity G. Salmon, Sara Sayedi, Christina Schadel, Edward A. G. Schuur, Sarah Shakil, Arial J. Shogren, Jens Strauss, Suzanne E. Tank, Brett F. Thornton, Rachael Treharne, Merritt Turetsky, Carolina Voigt, Nancy Wright, Yuanhe Yang, Jay P. Zarnetske, Qiwen Zhang, Scott Zolkos

Faculty Publications

Climate change is an existential threat to the vast global permafrost domain. The diverse human cultures, ecological communities, and biogeochemical cycles of this tenth of the planet depend on the persistence of frozen conditions. The complexity, immensity, and remoteness of permafrost ecosystems make it difficult to grasp how quickly things are changing and what can be done about it. Here, we summarize terrestrial and marine changes in the permafrost domain with an eye toward global policy. While many questions remain, we know that continued fossil fuel burning is incompatible with the continued existence of the permafrost domain as we know …

Microbiome Assembly In Thawing Permafrost And Its Feedbacks To Climate, Jessica G. Ernakovich, Robyn A. Barbato, Virginia I. Ritch, Christina Schadel, Rebecca E. Hewitt, Stacey J. Doherty, Emily D. Whalen, Benjamin Abbott, Jiri Barta, Christina Biasi, Chris L. Chabot, Jenni Hultman, Christian Knoblauch, Maggie C. Y. Lau Vetter, Mary-Cathrine Leewis, Susanne Liebner, Rachel Mackelprang, Tullis C. Onstott, Andreas Richter, Ursel M. E. Schutte, Henri M. P. Siljanen, Neslihan Tas, Ina Timling, Tatiana A. Vishnivetskaya, Mark P. Waldrop, Matthias Winkel

Faculty Publications

The physical and chemical changes that accompany permafrost thaw directly influence the microbial communities that mediate the decomposition of formerly frozen organic matter, leading to uncertainty in permafrost–climate feedbacks. Although changes to microbial metabolism and community structure are documented following thaw, the generality of post-thaw assembly patterns across permafrost soils of the world remains uncertain, limiting our ability to predict biogeochemistry and microbial community responses to climate change. Based on our review of the Arctic microbiome, permafrost microbiology, and community ecology, we propose that Assembly Theory provides a framework to better understand thaw-mediated microbiome changes and the implications for community …

Core Strength, Krysten Godfrey Maddocks

UNH Today Archive

No abstract provided.

Celebrating Sustainability, Unh Communications And Public Affairs

UNH Today Archive

No abstract provided.

Stabilization Of Phenanthrene Anions In Helium Nanodroplets, Siegfried Kollotzek, Farhad Izadi, Miriam Meyer, Stefan Bergmeister, Fabio Zappa, Stephan Denifl, Olof E. Echt, Paul Scheier, Elisabeth Gruber

Faculty Publications

It has been debated for years if the polycyclic aromatic hydrocarbon phenanthrene exists in its anionic form, or, in other words, if its electron affinity (EA) is positive or negative. In this contribution we confirm that the bare phenanthrene anion Ph^- created in a binary collision with an electron at room temperature has a lifetime shorter than microseconds. However, the embedding of neutral phenanthrene molecules in negatively charged helium nanodroplets enables the formation of phenanthrene anions by charge transfer processes and the stabilization of the latter in the ultracold environment. Gentle shrinking of the helium matrix of phenanthrene-doped HNDs …

The Effects Of Disorder In Van Der Waals Materials, Jake Riffle

Doctoral Dissertations

Due to their two-dimensional structure and wide range of electronic behaviors, van derWaals materials have garnered a lot of attention for new technological applications. However, much is still unknown about the consequences that impurities and disorder have on the performance of many new van der Waals materials. In my research I use scanning tunneling microscopy(STM) and electronic transport techniques to study the different types of disorder in three common van der Waals materials: tantalum disulfide (TaS2), black phosphorus (BP), and two-dimensional graphene. In TaS2 I show a sample preparation dependence on the surface state of the bulk crystal and emphasize …

Heat Transport By Baroclinic Acoustic Streaming, Jacques Abdul Massih

Doctoral Dissertations

Acoustic streaming refers to time-averaged flows generated by time-periodic sound waves. In classic“Rayleigh streaming”, the mean flow is generated by the interaction of a standing acoustic wave with a solid boundary (e.g., a channel wall). Applications of acoustic streaming include inducing fluid mixing in microfluidic medical devices, improving the efficiency of chemical reactions, and enhancing heat transfer. Recently, Chini et al. [J. Fluid Mech., Vol. 744 (2014)] and Michel & Chini [J. Fluid Mech., Vol. 858 (2019)] demonstrated that strong acoustic streaming flows can be generated in gases subjected to an imposed cross-channel temperature gradient. In contrast with Rayleigh streaming, …

Penalized Regression Splines-Based Tests For Comparing Two Time Series With Unequal Lengths, Mirajul Islam

Doctoral Dissertations

The Spline-based modeling has been an established tool for parametric and nonparametricregression modeling because of its continuous progress on theoretical and computational fronts over the last three decades. This thesis explores the idea of penalized spline modeling and goodness of fit testing in the context of time series testing in the frequency domain approach. The comparison of different time series is an important topic in statistical data analysis and has various applications in scientific research. One approach to identifying similarities or dissimilarities between two stationary processes is to compare the spectral densities of both time series. This thesis examines whether …

Efficient Data-Driven Robust Policies For Reinforcement Learning, Bahram Behzadian

Doctoral Dissertations

Applying the reinforcement learning methodology to domains that involve risky decisions like medicine or robotics requires high confidence in the performance of a policy before its deployment. Markov Decision Processes (MDPs) have served as a well-established model in reinforcement learning (RL). An MDP model assumes that the exact transitional probabilities and rewards are available. However, in most cases, these parameters are unknown and are typically estimated from data, which are inherently prone to errors. Consequently, due to such statistical errors, the resulting computed policy's actual performance is often different from the designer's expectation. In this context, practitioners can either be …

Sociocultural Dimensions Of Environmental Stewardship In New Hampshire: Implications For Adult Environmental Education, Ian Patrick Hanley

Doctoral Dissertations

The overarching aim of this dissertation is to expand evidence and theory of adult identity processes in the context of environmental stewardship, as well as to provide knowledge and recommendations to environmental stewardship and environmental education professionals. The intent is to better understand variation in how adult environmental stewards report on and value their own engagement with both sociocultural and natural systems. This line of inquiry stems from the fundamental claim that environmental stewardship activity is not singularly based on environmental content knowledge but is also related to forms of cultural and social engagement. By recognizing these dual aspects of …

Water Droplet Machining And Droplet Impact Mechanics, Benjamin Mitchell

Doctoral Dissertations

Water Droplet Machining (WDM) is a new manufacturing process, which uses a series of high-velocity, pure-water droplets to impact and erode metal workpieces, for the purpose of through-cutting, milling and surface profiling. The process is conducted within a vacuum environment to suppress aerodynamic drag and atomization of the waterjet and droplet stream. This preserves droplet momentum and allows for a more efficient transfer of energy between the water and workpiece, than in standard atmospheric pressure. As a new manufacturing technique, parameter-specific details and characteristics of this process are absent from the scientific literature. Furthermore, the erosion mechanisms involved in droplet-solid …

Query-Specific Subtopic Clustering In Response To Broad Queries, Sumanta Kashyapi

Doctoral Dissertations

Information Retrieval (IR) refers to obtaining valuable and relevant information from various sources in response to a specific information need. For the textual domain, the most common form of information sources is a collection of textual documents or text corpus. Depending on the scope of the information need, also referred to as the query, the relevant information can span a wide range of topical themes. Hence, the relevant information may often be scattered through multiple documents in the corpus, and each satisfies the information need to varying degrees. Traditional IR systems present the relevant set of documents in the form …

The Efficacy Of Response To Intervention On Academic Outcomes At The Secondary School Level In A New England School District, Kimberly Mcglinchey

Doctoral Dissertations

Educational policies and practices have had a long-standing emphasis of conducting incoming literacy screenings to determine who is at risk for school failure. Response to intervention (RTI) is an intervention program designed to deliver educational resources to students who fall below what is deemed an acceptable level of proficiency as viewed through the early screening process. The goal of the program is to provide early mitigation in order to catch students up to their peers, and to limit misidentification into special education. Studies have evaluated the success of the program in grades K-3 and shown mixed success. However, there was …

The Active Tail In The Mms Era: An Ion Perspective, Anthony Jason Rogers

Doctoral Dissertations

The Earth's magnetic field has a complex and dynamic relationship with the greater solar system. The solar wind and interplanetary magnetic field extend the influence of the Sun's atmosphere to the orbit of Earth and well beyond, carrying charged particles in a constant stream of varying density and velocity. These solar influences carry energy which interacts with every object they encounter, including the Earth and its magnetic field.

The primary mechanism for the energetic interaction and exchange of energy between the Earth's magnetic field and the solar wind is called Magnetic Reconnection, a process by which two opposing magnetic fields …

Analysis Of Turbulence In The Near-Shore Marine Atmospheric Surface Layer Using Sonic Anemometer Data, Alberto Javier Bodoque Garcia

Master's Theses and Capstones

This thesis investigates turbulence in the marine atmospheric boundary layer (MABL), above,the wave boundary layer (WBL). To conduct this research, wind velocity and temperature data was collected by a sonic anemometer located onWood, Island, NH, mounted to a tower 4 meters above the ground. To study turbulence in the MABL, variables such as Reynolds stress and friction velocity were calculated for different days in August 2019. Friction velocity was calculated following three different approaches: the first approach employs the eddy covariance method, the second employs a tilt correction to the eddy covariance method, and the third uses the Reynolds stress …

Crystal Plasticity Modeling For Predicting Load Reversals In Dual Phase Steels And Aluminium Alloys: Applications To Predicting Springback Behavior, Sowmya Daroju

Master's Theses and Capstones

Numerical modeling of sheet metal forming is of growing interest for industry and academia. Metal forming operations often involve non-monotonic deformation paths with frequent unloading. This research explores the use of elasto-plastic self-consistent (EPSC) modeling in predicting the monotonic and load reversal deformation of aluminum alloys, and dual-phase steels. The EPSC model considers anisotropic elasticity, dislocation density-hardening, and intra granular slip system-level backstress fields in addition to accounting for inter granular stress fields; the detailed contribution of this helps in properly predicting the phenomena such as unloading non-linearity, the Bauschinger effect (BE), and changes in hardening rates during reversals. In …

Methods For Determining The Refractive Index Structure Parameter In The Marine Atmospheric Boundary Layer, Daniel Joseph Laughlin

Master's Theses and Capstones

An experimental study of the marine atmospheric boundary layer effects on the index of refraction was conducted off the coast of Portsmouth, NH between Battery Farnsworth and Wood Island. This study aimed to compare measured changes in the refractive index structure parameter (Cn2) to estimates using time series data of single point atmospheric variables, including temperature, pressure, and wind velocity. A scintillometer transmitter and receiver located at Battery Farnsworth and Wood Island, respectively, provided direct measurements of Cn2. Data from a weather tower containing a sonic anemometer was used to estimate Cn2.

Three methods of analysis to estimate Cn2 from …

Soil Volatile Organic Compound Emissions In Response To Soil Warming And Nitrogen Deposition, A. L. Romero-Olivares, C. L. Davie-Martin, M. Kramshoj, R. Rinnan, Serita D. Frey

Faculty Publications

Biogenic volatile organic compounds (VOCs) play crucial roles in ecosystems at multiple scales, ranging from mediating soil microbial interactions to contributing to atmospheric chemistry. However, soil VOCs and how they respond to environmental change remains understudied. We aimed to assess how 2 abiotic global change drivers, soil warming and simulated nitrogen (N) deposition, impact soil VOC emissions over time in a temperate forest. We characterized the effect of warming, N deposition, and their interaction on the composition and emissions of soil VOCs during the growing season of 2 consecutive years. We found that chronic warming and N deposition enhanced total …

Getting Smart, Unh Communications And Public Affairs

UNH Today Archive

No abstract provided.

Controls On Buffering And Coastal Acidification In A Temperate Estuary, Christopher W. Hunt, Joseph Salisbury, Douglas Vandemark

Faculty Publications

Estuaries may be uniquely susceptible to the combined acidification pressures of atmospherically driven ocean acidification (OA), biologically driven CO2 inputs from the estuary itself, and terrestrially derived freshwater inputs. This study utilized continuous measurements of total alkalinity (TA) and the partial pressure of carbon dioxide (pCO2) from the mouth of Great Bay, a temperate northeastern U.S. estuary, to examine the potential influences of endmember mixing and biogeochemical transformation upon estuary buffering capacity (β–H). Observations were collected hourly over 28 months representing all seasons between May 2016 and December 2019. Results indicated that endmember mixing explained most of the observed variability …

Convergence: Eos News And Updates, April 2022, Unh Institute For The Study Of Earth, Oceans And Space

Convergence: EOS News and Updates

No abstract provided.

Paul Robertson: Lecturer In The Department Of Classics, Humanities, And Italian Studies, Brigid C. Casellini

Inquiry Journal Spring 2022

Paul Robertson is a lecturer in the Department of Classics, Humanities, and Italian Studies at the University of New Hampshire. Below is a correspondence with Dr. Robertson about his own research and his mentoring experiences with undergraduate students.