Digital Commons Network^™

Modeling Actinic Flux And Photolysis Frequencies In Dense Biomass Burning Plumes, Jan-Lukas Tirpitz, Santo Fedele Colosimo, Nathaniel Brockway, Robert Spurr, Matt Christi, Samuel Hall, Kirk Ullmann, Johnathan Hair, Taylor Shingler, Rodney Weber, Jack E. Dibb, Richard Moore, Elizabeth Wiggins, Vijay Natraj, Nicolas Theys, Jochen Stutz

Faculty Publications

Biomass burning (BB) affects air quality and climate by releasing large quantities of gaseous and particulate pollutants into the atmosphere. Photochemical processing during daylight transforms these emissions, influencing their overall environmental impact. Accurately quantifying the photochemical drivers, namely actinic flux and photolysis frequencies, is crucial to constraining this chemistry. However, the complex radiative transfer within BB plumes presents a significant challenge for both direct observations and numerical models.

This study introduces an expanded version of the 1D VLIDORT-QS radiative transfer (RT) model, named VLIDORT for photochemistry (VPC). VPC is designed for photochemical and remote sensing applications, particularly in BB plumes …

A Systematic Review Of Environmentally Persistent Free Radical (Epfr) Formation, Characteristics, And Health Effects: Are There Sufficient Data For Risk Assessment?, Avinash Kumar, Divine Nde, Chuqi Guo, Rashmi Pathak, Fox Foley, Syed Ahmad, Prakash Dangal, Farhana Hasan, Myron Lard, Ankit Aryal, Martine E. Mathieu-Campbell, Jennifer Irving, Oluwafeyikemi Ogunmusi, Jennifer Richmond-Bryant, Slawomir Lomnicki, Lavrent Khachatryan, Stephania A. Cormier, Tammy R. Dugas

Faculty Publications

Environmentally persistent free radicals (EPFRs) are stable free radicals formed on particulate matter (PM) through processes such as combustion and pyrolysis. These free radicals are generated on transition metal oxide surfaces in the presence of aromatic precursors. Exposure to EPFRs occurs primarily via inhalation of PM deriving from combustion, traffic, industrial activities, and both indoor and outdoor burning. Other environmental factors that might generate EPFRs are radon, electronic and tobacco cigarettes. EPFRs exhibit unexpectedly long half-lives, ranging from several weeks to, in some cases, several years. EPFRs may be carbon-centered, oxygen-centered or mixed, identified by g-values exhibited in electron paramagnetic …

Aromatic Interactions At The Ligand–Protein Interface: Implications For The Development Of Docking Scoring Functions, Michal Brylinski

Faculty Publications

© 2017 John Wiley & Sons A/S The ability to design and fine-tune non-covalent interactions between organic ligands and proteins is indispensable to rational drug development. Aromatic stacking has long been recognized as one of the key constituents of ligand–protein interfaces. In this communication, we employ a two-parameter geometric model to conduct a large-scale statistical analysis of aromatic contacts in the experimental and computer-generated structures of ligand–protein complexes, considering various combinations of aromatic amino acid residues and ligand rings. The geometry of interfacial π–π stacking in crystal structures accords with experimental and theoretical data collected for simple systems, such as …

Computational Study Of Mos2/Hfo2 Defective Interfaces For Nanometer-Scale Electronics, Santosh Kc, Roberto Longo, Robert Wallace, Kyeongjae Cho

Faculty Publications

Atomic structures and electronic properties of MoS2/HfO2 defective interfaces are investigated extensively for future field-effect transistor device applications. To mimic the atomic layer deposition growth under ambient conditions, the impact of interfacial oxygen concentration on the MoS2/HfO2 interface electronic structure is examined. Then, the effect on band offsets (BOs) and the thermodynamic stability of those interfaces is investigated and compared with available relevant experimental data. Our results show that the BOs can be modified up to 2 eV by tuning the oxygen content through, for example, the relative partial pressure. Interfaces with hydrogen impurities as well as various structural disorders …

Regional Patterns In The Otolith Chemistry Of Juvenile Spotted Seatrout (Cynoscion Nebulosus) Differ Under Contrasting Hydrological Regimes, Chet F. Rakocinski, Bruce H. Comyns, Mark S. Peterson, Alan M. Shiller

Faculty Publications

The value of using otolith chemistry to characterize recruitment in terms of natal source regions depends on how consistently spatio-temporal variation can be resolved. The objective of this study was to compare regional classification patterns in the otolith chemistry of juvenile Spotted Seatrout (Cynoscion nebulosus) between two years experiencing disparate hydrological regimes, and separated by a five year interlude. Spatial patterns in the whole-otolith chemistry of juveniles of this estuarine-dependent species were compared between years using five otolith elements and two stable isotopes. Consistent size-related trends in uptake and deposition were evidenced by parallel ontogenetic relationships for six otolith variables. …

Application Of Otolith Chemical Signatures To Estimate Population Connectivity Of Red Snapper In The Western Gulf Of Mexico, Michelle Zapp Sluis, Beverly K. Barnett, William F. Patterson, James H. Cowan, Alan M. Shiller

Faculty Publications

Otolith chemical signatures of Red Snapper Lutjanus campechanus from six nursery regions were used to estimate the sources of recruits to four sampling regions in the western Gulf of Mexico (Gulf) and to estimate whether postsettlement mixing of Red Snapper occurs between the U.S. and Mexican portions of the western Gulf. In a previous study, region-specific otolith signatures (element : Ca ratios: Ba:Ca, Mg:Ca, Mn:Ca, Sr:Ca, and Li:Ca; stable isotope delta values: δ¹³C and δ¹⁸O) were developed based on age-0 Red Snapper (2005–2007 year-classes) sampled from the six nursery areas. In the present study, subadult and …

Electronic Properties Of Inp (001)/Hfo2 (001) Interface: Band Offsets And Oxygen Dependence, Santosh Kc

Faculty Publications

Using ab-initio methods, atomic structures and electronic properties of InP (001)/HfO2 (001) interface are studied within the framework of density functional theory. We examine the InP/HfO2 model interface electronic structures under varying oxidation conditions. The effects of indium and phosphorous concentrations on interfacial bonding, defect states, band offsets, and the thermodynamic stability at the interface are also investigated. The origin of interfacial gap states in InP (001)/HfO2 (001) interface are proposed, mainly from the P-rich oxides, which is validated by our experimental work. This highlights the importance of surface passivation prior to high-κ deposition based on the in situ spectroscopic …

Practical Objectivity: Keeping Natural Science Natural, Alan G. Padgett

Faculty Publications

No abstract provided.

Open For Learning: The Cms And The Open Learning Network, Jon Mott, David Wiley

Faculty Publications

The course management system (CMS) reinforces the status quo and hinders substantial teaching and learning innovation in higher education. It does so by imposing artificial time limits on learner access to course content and other learners, privileging the role of the instructor at the expense of the learner, and limiting the power of the network effect in the learning process. The open learning network (OLN)—a hybrid of the CMS and the personal learning environment (PLE)—is proposed as an alternative learning technology environment with the potential to leverage the affordances of the Web to dramatically improve learning.

Early Agriculture In The Maya Lowlands, Mary D. Pohl, Kevin O. Pope, John G. Jones, John S. Jacob, Dolores R. Piperno, Susan D. Defrance, David L. Lentz, John A. Gifford, Marie E. Danforth, J. Kathryn Josserand

Faculty Publications

Wetland research in northern Belize provides the earliest evidence for development of agriculture in the Maya Lowlands. Pollen data confirm the introduction of maize and manioc before 3000 B.C. Dramatic deforestation, beginning ca. 2500 B.C. and intensifying in wetland environments ca. 1500-1300 B.C., marks an expansion of agriculture, which occurred in the context of a mixed foraging economy. By 1000 B.C. a rise in groundwater levels led farmers to construct drainage ditches coeval with the emergence of Maya complex society ca. 1000-400 B.C. Field manipulations often involved minor modifications of natural hummocks. Canal systems are not as extensive in northern …

Chemical Species Spatial Distribution And Relationship To Elevation And Snow Accumulation Rate Over The Greenland Ice Sheet, Qinzhao Yang, Paul A. Mayewski, E. Linder, Sallie I. Whitlow, Mark S. Twickler

Faculty Publications

Major chemical species (Cl−, NO−3, SO2−4, Na+, K+, Mg2+, Ca2+) from 24 snowpits (sampled at a resolution of 3 cm, total 2995 samples) collected from northern, central, and southern Greenland were used for this investigation. The annual and seasonal (winter and summer) concentration of each chemical species was calculated and used to study the spatial distribution of chemical species over the central portion of the Greenland Ice Sheet. A two‐sided t‐distribution test (α = 0.05) suggests that concentrations of major chemical species in snow do not vary significantly over this portion of central Greenland. The relationship between chemical concentration and …