Repeatability of a dynamic rollover test system

Objective: The goal of this study was to characterize the rollover crash and to evaluate the repeatability of the Dynamic Rollover Test System (DRoTS) in terms of initial roof-to-ground contact conditions, vehicle kinematics, road reaction forces, and vehicle deformation.

Methods: Four rollover crash tests were performed on 2 pairs of replicate vehicles (2 sedan tests and 2 compact multipurpose van [MPV] tests), instrumented with a custom inertial measurement unit to measure vehicle and global kinematics and string potentiometers to measure pillar deformation time histories. The road was instrumented with load cells to measure reaction loads and an optical encoder to measure road velocity. Laser scans of pre- and posttest vehicles were taken to provide detailed deformation maps.

Results: Initial conditions were found to be repeatable, with the largest difference seen in drop height of 20 mm; roll rate, roll angle, pitch angle, road velocity, drop velocity, mass, and moment of inertia were all 7% different or less. Vehicle kinematics (roll rate, road speed, roll and pitch angle, global Z′ acceleration, and global Z′ velocity) were similar throughout the impact; however, differences were seen in the sedan tests because of a vehicle fixation problem and differences were seen in the MPV tests due to an increase in reaction forces during leading side impact likely caused by disparities in roll angle (3° difference) and mass properties (2.2% in moment of inertia [MOI], 53.5 mm difference in center of gravity [CG] location).

Conclusions: Despite those issues, kinetic and deformation measures showed a high degree of repeatability, which is necessary for assessing injury risk in rollover because roof strength positively correlates with injury risk (Brumbelow 2009). Improvements of the test equipment and matching mass properties will ensure highly repeatable initial conditions, vehicle kinematics, kinetics, and deformations.     

In Situ Solidification (ISS) of River Sediments: Pilot Demonstration and Discussion of ISS as a Remedial Alternative to Dredging and Capping

In situ solidification (ISS) is a proven technology for remediation of upland site soils, but has not been thoroughly demonstrated for use in impacted underwater sediments. This article describes the first successful use of ISS techniques to solidify underwater sediments containing manufactured gas plant non‐aqueous‐phase liquid (NAPL). The techniques consisted of mixing cementitious grout with the sediments in situ to create a monolith that immobilized the contaminants, significantly decreased the hydraulic conductivity, and also vastly decreased contaminant leaching potential of the sediments. The success of this pilot demonstration project suggests that ISS may be a viable alternative for: sites requiring deep dredging; large volume projects on urban waterways where staging and amending areas are limited; sites with NAPL impacts that cannot be controlled during dredging; and sites where eventual NAPL breakthrough is anticipated if reactive caps are employed. The potential economic, environmental, and operational benefits of this technology will be discussed. This article focuses on the primary objectives of the pilot demonstration: to meet quantitative performance criteria for strength and hydraulic conductivity; to assess the leach performance of the solidified sediments; and to satisfy water quality parameters for turbidity, pH, and sheen. Approach/activities: The pilot study utilized a customized marine platform (modular floats, tug boats, etc.) and full‐scale ISS equipment (auger rig, silos, etc.) and varied operational parameters to provide a range of data to assist in evaluating the feasibility and efficacy of the technology for use in similar environments and in planning future ISS projects on the water. Water quality controls and monitoring were implemented during the operation, and the study documented and evaluated the environmental disruption (short‐term impacts) and costs of the application of the ISS process to contaminated aquatic sediments. ©2016 Wiley Periodicals, Inc.     

Stable Isotope Probing to Confirm Field‐Scale Co‐Metabolic Biodegradation of 1,4‐Dioxane

1,4‐Dioxane, a common co‐contaminant with chlorinated solvents, is present in groundwater at Site 24 at Vandenberg Air Force Base in California. Historical use of chlorinated solvents resulted in concentrations of 1,4‐dioxane in groundwater up to approximately 2,000 μg/L. Starting in 2013, an in situ propane biosparge system operation demonstrated reductions in 1,4‐dioxane concentrations in groundwater. The work detailed herein extends the efforts of the first field demonstration to a second phase and confirms the biodegradation mechanism via use of stable isotope probing (SIP). After two months of operation, 1,4‐dioxane concentrations decreased approximately 45 to 83 percent at monitoring locations in the test area. The results of the SIP confirmed ¹³C‐enriched 1,4‐dioxane was transformed into dissolved inorganic carbon (suggesting mineralization to carbon dioxide) and incorporated into microbial biomass (likely attributed to metabolic uptake of biotransformation intermediates or of carbon dioxide).  ©2016 Wiley Periodicals, Inc.     

Modeling and inference of animal movement using artificial neural networks

Movement of animals in relation to objects in their environment is important in many areas of ecology and wildlife conservation. Tools for analysis of movement data, however, still remain rather limited. In previous work, we developed nonlinear regression models for movement in relation to a single landscape feature. Here we greatly expand these previous models by using artificial neural networks. The new models add substantial flexibility and capabilities, including the ability to incorporate multiple factors and covariates. We devise a likelihood-based model fitting procedure that utilizes genetic algorithms and demonstrate the approach with movement data for red diamond rattlesnakes. The proposed methodology can be useful for global positioning system tracking data that are becoming more common in studies of animal movement behavior.     

Impact of the 1998 Central American fires on PM2.5 mass and composition in the southeastern United States

The impact of the Central American fires on PM_2.5 mass concentration and composition in the Tennessee Valley region during portions of May, 1998, has been quantified. Elevated concentrations of smoke aerosol tracers—fine potassium, (and to a lesser extent, calcium and silicon) and, where available, organic and elemental carbon—were observed in the region during times in which satellite imagery (TOMS and GOES-8) showed regional transport of hazy, smoky airmasses from southern Mexico and adjacent areas of Central America. Back-trajectories from network sites in the Tennessee Valley network were consistent with this regional transport. The extent of transport of extra-regional fine particle mass during May, 1998, is discussed relative to the new US fine particle mass-based standards for fine particulate matter.     

Cyber first aid: proactive risk management and decision-making

Public and private organizations need a robust approach to prepare, respond, and recover from cyber-attacks. This perspective article will refer to such an approach as Cyber First AID—adaptable, integrated, and deliberate. Adaptable describes that one size does not fit all; Integrated means the effort is throughout the organization; and Deliberate describes plans that are reviewed periodically and practiced, in which all members of the organization know their respective roles and responsibilities. The article outlines a decision-making process for how to minimize the impacts of cyber threats, maintain stakeholder and customer confidence, and help organizations to adaptively manage and respond to cyber threats in rapidly changing cyber environments.     

The influence of age on the morbidity and mortality of pedestrian victims

OBJECTIVES: The present study examined the influence of age on the morbidity and mortality of pedestrian victims while controlling for confounding factors. METHODS: The Pedestrian Crash Data Study (PCDS) database was used for a cross-sectional study to compare the outcome of senior (age >or=60 years) and adult (age 19 to 50 years) pedestrian victims. The outcome measures were the Injury Severity Score (ISS), Maximum Abbreviated Injury Score (MAIS), Abbreviated Injury Scale (AIS), and Mortality. Logistic regression models were used to estimate age-associated risks while controlling for confounders such as vehicle type, impact speed, and pedestrian height, weight, and gender. RESULTS: Compared to the adult victims, the seniors had a higher average ISS (23 vs. 16, p = 0.018) and higher mortality (30 percent vs. 11 percent, p or=9 (odds ratio = 2.72; 95 percent CI: 1.31-5.68) and to die (odds ratio = 6.68; 95 percent CI: 2.37-19.88). The seniors were approximately twice as likely to have higher AIS scores to almost every body region. CONCLUSIONS: The adjusted age-dependent risks indicated by the current study should be considered when calculating or projecting pedestrian morbidity and mortality. Adjustment in statistical models is essential to achieve precise risk estimates and in turn to appropriately allocate public health rescores.     

Soil uptake of carbon monoxide emitted in the exhaust of a gasoline-powered engine

Carbon monoxide (CO) poses dangers to both human and environmental health, sickening thousands of people annually in the United States and decreasing the capacity of the atmosphere to oxidize greenhouse gases. Globally, soil ecosystems with their populations of bacteria, fungi, and algae are estimated to remove 9-36% of total CO emissions, which makes them the second largest CO sink after hydroxyl oxidation. Our aim was determine whether soil ecosystems could remove CO from an atmosphere mixed with gasoline-powered engine exhaust. Sealed microcosms containing no soil (NoSoil), nonvegetated soil (Soil), or vegetated soil (Soil+Veg), were exposed to 800, 100, and 50 ppm of CO for 1 hr. The uptake rate of CO was found to be higher at the 800 ppm level suggesting first-order rate kinetics. Soil+Veg exhibited a significantly higher CO uptake rate than either Soil or NoSoil (P<0.05), and Soil exhibited significantly higher uptake than NoSoil (P<0.05). As a free ecosystem service, the uptake of CO by soil ecosystems needs to be properly valued and ecologically engineered into the urban traffic network in a manner analogous to how wetlands, vegetated swales, and other ecologically based storm water treatment systems have improved urban runoff.