Transition metal nitride catalysts for selective conversion of oxygen-containing molecules.

Earth abundant transition metal nitrides (TMNs) are a promising group of catalysts for a wide range of thermocatalytic, electrocatalytic and photocatalytic reactions, with potential to achieve high activity and selectivity while reducing reliance on the use of Pt-group metals. However, current fundamental understanding of the active sites of these materials and the mechanisms by which selective transformations occur is somewhat lacking. Recent investigations of these materials from our group and others have utilized probe molecules, model surfaces, and techniques to elucidate the origin of their activity, strong metal-support interactions, and unique d-band electronic structures.

California Case Study of Wildfires and Prescribed Burns: PM Emissions, Concentrations, and Implications for Human Health.

Wildfires are a significant threat to human health, in part through degraded air quality. Prescribed burning can reduce wildfire severity but can also lead to an increase in air pollution. The complexities of fires and atmospheric processes lead to uncertainties when predicting the air quality impacts of fire and make it difficult to fully assess the costs and benefits of an expansion of prescribed fire.

Air quality impacts of observationally constrained biomass burning heat flux inputs.

Biomass burning is a major contributor to ambient air pollution worldwide, and the accurate characterization of biomass burning plume behavior is an important consideration for air quality models that attempt to reproduce these emissions. Smoke plume injection height, or the vertical level into which the combustion emissions are released, is an important consideration for determining plume behavior, transport, and eventual impacts. This injection height is dependent on several fire properties, each with estimates and uncertainties in terms of historical fire emissions inventories.

Role of HO in Catalytic Conversion of C Molecules.

Due to their role in controlling global climate change, the selective conversion of C molecules such as CH, CO, and CO has attracted widespread attention. Typically, HO competes with the reactant molecules to adsorb on the active sites and therefore inhibits the reaction or causes catalyst deactivation. However, HO can also participate in the catalytic conversion of C molecules as a reactant or a promoter.

Longitudinal Changes in the Body Mass Index of British Army Pilots.

Aircraft are manufactured according to design parameters that must account for the size and physical characteristics of the pilot. While cockpit dimensions, seats, restraints, and related components do not change substantially over the airframe lifecycle, it is conceivable that the occupant may, even if initially well-suited. This investigation focused on longitudinal body mass index (BMI) changes within a cohort of British Army Air Corps pilots.

Industrial-era decline in Arctic methanesulfonic acid is offset by increased biogenic sulfate aerosol.

Marine phytoplankton are primary producers in ocean ecosystems and emit dimethyl sulfide (DMS) into the atmosphere. DMS emissions are the largest biological source of atmospheric sulfur and are one of the largest uncertainties in global climate modeling. DMS is oxidized to methanesulfonic acid (MSA), sulfur dioxide, and hydroperoxymethyl thioformate, all of which can be oxidized to sulfate.

The serum glycolate concentration: its prognostic value and its correlation to surrogate markers in ethylene glycol exposures.

Context: Ethylene glycol poisoning manifests as metabolic acidemia, acute kidney injury and death. The diagnosis and treatment depend on history and biochemical tests. Glycolate is a key toxic metabolite that impacts prognosis, but assay results are not widely available in a clinically useful timeframe.

Evaluating health outcome metrics and their connections to air pollution and vulnerability in Southern California's Coachella Valley.

The ongoing desiccation of California's Salton Sea has led to increasing concerns about air quality and health for its surrounding communities, including the nearby Coachella Valley - a region already experiencing severe air quality and health disparities. Here we explore spatial air pollution and human health disparities in the Coachella Valley with particular attention to disparities arising across population characteristics including both socioeconomic and demographic vulnerabilities. We use two different measures of respiratory and cardiovascular health outcomes at the individual and census tract levels - one measure based on a randomly sampled telephone survey and the other measure based on emergency room visitation data - to investigate the degree to which these health outcomes are connected to air pollution and socioeconomic metrics.

Variability in Aromatic Aerosol Yields under Very Low NO Conditions at Different HO/RO Regimes.

Current chemical transport models generally use a constant secondary organic aerosol (SOA) yield to represent SOA formation from aromatic compounds under low NO conditions. However, a wide range of SOA yields (10 to 42%) from -xylene under low NO conditions is observed in this study. The chamber HO/RO ratio is identified as a key factor explaining SOA yield variability: higher SOA yields are observed for runs with a higher HO/RO ratio.

Integrated effects of SCR, velocity, and Air-fuel Ratio on gaseous pollutants and CO emissions from China V and VI heavy-duty diesel vehicles.

Vehicle exhaust, an important source of air pollution, is affected by many factors, including driving conditions, combustion efficiencies, and the usage of emission control devices. In this study, the Portable Emission Measurement System (PEMS) was used to test the emissions from China V and China VI heavy-duty diesel vehicles to evaluate the integrated effects of Selective Catalytic Reduction (SCR), velocity, and air-fuel ratio on carbon dioxide (CO) and nitrogen oxide (NO) emissions. Our results reveal that the average distance-based CO and CO emission factors at high velocities (50-90 km/h) are 25% and 61% lower than those at low velocities (less than 50 km/h).

Biologically-Based and Physiochemical Life Support and In Situ Resource Utilization for Exploration of the Solar System-Reviewing the Current State and Defining Future Development Needs.

The future of long-duration spaceflight missions will place our vehicles and crew outside of the comfort of low-Earth orbit. Luxuries of quick resupply and frequent crew changes will not be available. Future missions will have to be adapted to low resource environments and be suited to use resources at their destinations to complete the latter parts of the mission.

SPATIAL VARIATION OF WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS) POPULATION IMPACTS AND RECOVERY FROM EPIZOOTIC HEMORRHAGIC DISEASE.

Epizootic hemorrhagic disease (EHD) is the most significant source of viral disease-related mortality in white-tailed deer (Odocoileus virginianus) in the US. Deer mortality from EHD has increased in the state of Michigan, US, since 2006, with the largest outbreak occurring in 2012. The 2012 outbreak provided an opportunity to evaluate how this disease affected EHD-related mortality in deer populations at a spatial scale typical of that expected for the greatest disease risk.

Changing Nature of Organic Carbon over the United States.

Total organic carbon (TOC) mass concentrations are decreasing across the contiguous United States (CONUS). We investigate decadal trends in organic carbon (OC) thermal fractions [OC1 (volatilizes at 140 °C), OC2 (280 °C), OC3 (480 °C), OC4 (580 °C)] and pyrolyzed carbon (PC), reported at 121 locations in the nteragency onitoring of tected isual nvironments (IMPROVE) network from 2005 to 2015 for 23 regions across the CONUS. Reductions in PC and OC2 drive decreases in TOC (TOC = OC1 + OC2 + OC3 + OC4 + PC) mass concentrations.

Spatial-temporal dynamics of hunter effort for wild turkeys in Michigan.

Wild turkeys (Meleagris gallopavo; hereafter turkeys) are an important game animal whose popularity among hunters has increased in recent decades. Yet, the number of hunters pursuing turkeys appears to be in flux, patterns of hunter abundance have primarily been described at broad spatial scales, and the ability of management to impact hunter numbers in the post-restoration era of management through opportunity for quality hunting is unclear. We used county-scale estimates of turkey hunter numbers collected over a 14-year period (2001-2014) and time-series analyses to evaluate the spatial scales at which spring and fall turkey hunter populations fluctuate, and also used generalized linear mixed models to evaluate whether attributes related to quality turkey hunting explain recent patterns in hunter abundance.

The role of drought as a determinant of hemorrhagic disease in the eastern United States.

Bluetongue virus and epizootic hemorrhagic disease (HD) virus are globally distributed, vector-borne viruses that infect and cause disease in domestic and wild ruminant species. The forces driving increases in resulting HD may be linked to weather conditions and increasing severity has been noted in northerly latitudes. We evaluated the role of drought severity in both space and time on changes in HD reports across the eastern United States for a recent 15 year period.

Operators' views of mobile equipment ingress and egress safety.

A large proportion of non-fatal slips, trips, and falls (STFs) at surface mining facilities are associated with mobile equipment. Ingress and egress from mobile equipment can pose a fall risk to mobile equipment operators. The objective of this study was to determine mobile equipment operators' views of STF risks from mobile equipment, and to ascertain what factors, tasks, and conditions they perceive as contributing to these risks.

Vascular Patterns in the Heads of Dinosaurs: Evidence for Blood Vessels, Sites of Thermal Exchange, and Their Role in Physiological Thermoregulatory Strategies.

Body size has thermal repercussions that impact physiology. Large-bodied dinosaurs potentially retained heat to the point of reaching dangerous levels, whereas small dinosaurs shed heat relatively easily. Elevated body temperatures are known to have an adverse influence on neurosensory tissues and require physiological mechanisms for selective brain and eye temperature regulation.

The Frontoparietal Fossa and Dorsotemporal Fenestra of Archosaurs and Their Significance for Interpretations of Vascular and Muscular Anatomy in Dinosaurs.

The attachments of jaw muscles are typically implicated in the evolution and shape of the dorsotemporal fenestra on the skull roof of amniotes. However, the dorsotemporal fenestrae of many archosaurian reptiles possess smooth excavations rostral and dorsal to the dorsotemporal fossa which closely neighbors the dorsotemporal fenestra and jaw muscle attachments. Previous research has typically identified this region, here termed the frontoparietal fossa, to also have attachment surfaces for jaw-closing muscles.

Asthma and Rotary-Wing Military Aircrew Selection.

From a population-based perspective, reports in the peer-reviewed medical literature suggest an increase in the overall prevalence of asthma in recent decades. Applicants for military aviation training with a current or past history of asthma are generally excluded in the United Kingdom. In order to assess the impact of the prevalence of asthma on the available pool of military service candidates, the authors collected data on annual live births between 1916 and 2016 as well as peer-reviewed publications that provided insight into asthma prevalence trends within the United Kingdom across the last century (covering birth-year population cohorts ranging from 1924 to 1995).

Global tropospheric effects of aromatic chemistry with the SAPRC-11 mechanism implemented in GEOS-Chem version 9-02.

The Goddard Earth Observing System with chemistry (GEOS-Chem) model has been updated with the Statewide Air Pollution Research Center version 11 (SAPRC-11) aromatics chemical mechanism, with the purpose of evaluating global and regional effects of the most abundant aromatics (benzene, toluene, xylenes) on the chemical species important for tropospheric oxidation capacity. The model evaluation based on surface and aircraft observations indicates good agreement for aromatics and ozone. A comparison between scenarios in GEOS-Chem with simplified aromatic chemistry (as in the standard setup, with no ozone formation from related peroxy radicals or recycling of NO) and with the SAPRC-11 scheme reveals relatively slight changes in ozone, the hydroxyl radical, and nitrogen oxides on a global mean basis (1 %-4 %), although remarkable regional differences (5 %-20 %) exist near the source regions.

UK Military Rotary-Wing Accidents: 2000-2015.

Background: Analysis of mishap data is an obvious measure of performance for those who wish to improve flight safety and affect aviation capability development within military forces.

Methods: This study examined rotary-wing accident information held by UK Ministry of Defence authorities for the 16-yr (inclusive) period from January 2000 through December 2015 in order to ascertain incidence patterns. Serious accidents of military registered aircraft operated by Joint Helicopter Command, the Royal Navy, the Search and Rescue Force, and the Defence Helicopter Flying School were included in the analysis.

Value of protected areas to avian persistence across 20 years of climate and land-use change.

Establishing protected areas, where human activities and land cover changes are restricted, is among the most widely used strategies for biodiversity conservation. This practice is based on the assumption that protected areas buffer species from processes that drive extinction. However, protected areas can maintain biodiversity in the face of climate change and subsequent shifts in distributions have been questioned.

An analysis of injuries to front-end loader operators during ingress and egress.

Slips, trips, and falls from mobile mining equipment have been documented for decades. However, little research has been conducted to determine the events precipitating these incidents during ingress or egress. This study examined slips, trips, and falls sustained during ingress or egress from front-end loaders to determine the frequencies of factors that may contribute to injuries.

Investigation of human body vibration exposures on haul trucks operating at U.S. surface mines/quarries relative to haul truck activity.

Workers who operate mine haul trucks are exposed to whole-body vibration (WBV) on a routine basis. Researchers from the National Institute for Occupational Safety and Health (NIOSH) Pittsburgh Mining Research Division (PMRD) investigated WBV and hand-arm vibration (HAV) exposures for mine/quarry haul truck drivers in relation to the haul truck activities of dumping, loading, and traveling with and without a load. The findings show that WBV measures in weighted root-mean-square accelerations (a) and vibration dose value (VDV), when compared to the ISO/ANSI and European Directive 2002/44/EC standards, were mostly below the Exposure Action Value (EAV) identified by the health guidance caution zone (HGCZ).