Inventory and prediction of heavy-duty diesel vehicle emissions

A vehicle emissions inventory is an account of emissions produced by all vehicles in an area. Many different factors can affect the emissions and the measurement of the emissions that are used to create an emissions inventory. These factors for heavy-duty diesel vehicles have been addressed and their relative affect on emissions was evaluated from test data and analytical analyses. These elements can affect the emissions by a factor of 15 depending on testing conditions.;One purpose that an emissions database serves is to provide a source for predicting future emissions for a specific vehicle or many vehicles in a general area. Using a database directly for prediction is ideal, but no comprehensive data set currently exists that covers all of the different vehicle and component combinations that exist in current use. Numerical models can be used to take the existing information about vehicle emissions and calculate the emissions that would be produced by all the vehicles in an inventory. The Transportable Heavy-Duty Vehicle Emissions Testing Laboratories at WU have collected emissions data from heavy-duty vehicles for approximately 8 years. This existing data were used in an analysis to develop a method that can produce emissions factors in grams per mile for all heavy-duty vehicles from a small database of measured emissions. The method developed categorizes the emissions according to the vehicle speed and acceleration. The WVU emissions data were combined with truck activity data derived by Battelle Memorial Institute to create emissions factors in grains per mile that reflects actual driving patterns. These factors were then compared to measured emissions from the THDVETL and errors were found to be as low as 5%

Infrared Borescopic Evaluation of High-Energy and Long-Duration Ignition Systems for Lean/Dilute Combustion in Heavy-Duty Natural-Gas Engines

Natural gas (NG) is attractive for heavy-duty (HD) engines for reasons of cost stability, emissions, and fuel security. NG cannot be reliably compression-ignited, but conventional gasoline ignition systems are not optimized for NG and are challenged to ignite mixtures that are lean or diluted with exhaust-gas recirculation (EGR). NG ignition is particularly challenging in large-bore engines, where completing combustion in the available time is more difficult. Using two high-speed infrared (IR) cameras with borescopic access to one cylinder of an HD NG engine, the effect of ignition system on the early flame-kernel development and cycle-to-cycle variability (CCV) was investigated. Imaging in the IR yielded strong signals from water emission lines, which located the flame front and burned-gas regions and obviated image intensifiers. A 9.7-liter, six-cylinder engine was modified to enable exhaust-gas recirculation and to provide optical access. Three ignition technologies were studied: a conventional system delivering 65 mJ of energy to each spark, a high-energy conventional system delivering 140 mJ, and a Bosch Controlled Electronic Ignition (CEI) system. CEI uses electronics to extend the ignition event, yielding sparks up to 5 ms in duration with up to 300 mJ of energy. Air/fuel equivalence ratios, λ, as high as 1.6 (with minimum EGR) and EGR fractions as high as 23% (stoichiometric) were tested; ignition delay, engine-out emissions, fuel consumption and image-derived parameters were compared. In most lean or dilute cases, the 140-mJ system yielded the lowest CCV. The imagery provided information about the early stages of ignition and combustion, where pressure measurements are not reliable. Image-based metrics also revealed that early flame kernels located further from the head yielded better combustion, showing that borescopic IR imaging can provide guidance for future engine design.The information, data, or work presented herein was funded in part by the Office of Energy Efficiency and Renewable Energy (EERE), U.S. Department of Energy, under Award Number DE-EE0007307. We also thank Dr. Hao Chen and Angela Wu for their help with software and James Elkins for engine-head modifications.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143838/1/2018-01-1149.pd

The Backup Planning Scale (BUPS): A Brief, Self-Reported Measure of a Person's Tendency to Develop, Reserve, and Use Backup Plans

To mitigate uncertainty in their goal pursuits, people use backup plans, i.e., alternative means that are developed to potentially replace "Plan A." Several studies have demonstrated that backup plans can introduce unexpected costs into goal pursuits that decrease a person's motivation to continue using their "Plan A," and reduce their chances for achieving their goal. These existing studies used time-intensive experimental and/or observational approaches to assess the effects of backup planning. The present research examines the newly-developed Backup Planning Scale (BUPS) for its measurement invariance, reliability, validity, and other psychometric characteristics across three independent samples with more than 1,500 participants. Consistent with prior theorizing, we found support for a nine-item, three factor structure for the BUPS, indexing latent factors for a person's tendency to develop, reserve, and replace with (or use) backup plans. Furthermore, a novel "IRTree" based statistical technique provided evidence for the validity of the measure, as participants' responses to the BUPS were associated with their actual developing, reserving, and replacing backup planning behaviors in a logic task. We conclude that the freely-available BUPS is a simple, brief, reliable, and valid self-reported instrument for assessing backup planning behaviors across adulthood

A Conceptual Model of the Role of Relative Advantage, Compatibility and Complexity in Electronic Medical Records Implementation Success

Successful Electronic Medical Record (EMR) implementation is expected to help control costs and increase efficiencies in healthcare delivery while also improving the quality of care. EMR is an information technology innovation per research literature. It is therefore important that EMR implementations succeed. A large number of information technology implementations fail resulting in monetary and non-monetary losses. EMR implementations in the United States and around the world have been fraught with problems and delays, resulting in unsuccessful or partially successful implementations. Knowing factors that are associated with successful information technology implementations may help EMR implementations succeed. The goal of this research-in-progress is to investigate whether the factors relative advantage, compatibility and complexity, which have most often been associated with successful information technology implementations in other domains such as e-commerce, are also associated with successful EMR implementations

On the modeling of amplitude-sensitive electron spin resonance (ESR) detection using voltage-controlled oscillator (VCO)-based ESR-on-a-chip detectors

In this paper, we present an in-depth analysis of a voltage-controlled oscillator (VCO)-based sensing method for electron spin resonance (ESR) spectroscopy, which greatly simplifies the experimental setup compared to conventional detection schemes. In contrast to our previous oscillator-based ESR detectors, where the ESR signal was encoded in the oscillation frequency, in the amplitude-sensitive method, the ESR signal is sensed as a change of the oscillation amplitude of the VCO. Therefore, using VCO architecture with a built-in amplitude demodulation scheme, the experimental setup reduces to a single permanent magnet in combination with a few inexpensive electronic components. We present a theoretical analysis of the achievable limit of detection, which uses perturbation-theory-based VCO modeling for the signal and applies a stochastic averaging approach to obtain a closed-form expression for the noise floor. Additionally, the paper also introduces a numerical model suitable for simulating oscillator-based ESR experiments in a conventional circuit simulator environment. This model can be used to optimize sensor performance early on in the design phase. Finally, all presented models are verified against measured results from a prototype VCO operating at 14 GHz inside a 0.5 T magnetic field

Soluble α2-macroglobulin receptor is increased in endotracheal aspirates from infants and children after cardiopulmonary bypass

ObjectiveCytokine dysregulation contributes to the systemic inflammatory response after cardiopulmonary bypass. Clearance of cytokine binding proteins may be important in the resolution of inflammation. Our aim was to determine whether the cytokine binding protein α2-macroglobulin and its soluble receptor were upregulated in endotracheal aspirates from infants and children undergoing cardiopulmonary bypass.MethodsSeventy tracheal aspirates were collected before and after cardiopulmonary bypass from 35 infants and children undergoing surgical correction of congenital heart defects. α2-Macroglobulin and the soluble α2-macroglobulin receptor were identified by Western blot. With the use of multi-analyte cytokine profiling, pro-inflammatory and anti-inflammatory cytokines were quantified, normalized to total protein, and expressed as ratios. Paired t tests and Wilcoxon signed-rank tests were performed between prebypass and postbypass samples. Correlations were examined among α2-macroglobulin, soluble α2-macroglobulin receptor, cytokine ratios, and the clinical variables of cardiopulmonary bypass, aortic crossclamp, and circulatory arrest times.Resultsα2-Macroglobulin increased by 50% (mean densitometry increase 82,683 ± 184,594, P = .012), and soluble α2-macroglobulin receptor increased by 17% (mean densitometry increase 506,148 ± 687,037, P = .0001) after cardiopulmonary bypass. The ratio of interleukin-8/interleukin-4 increased by 136% (P = .0001), and interleukin-8/interleukin-10 increased by 102% (P = .001). The increase in soluble α2-macroglobulin receptor was positively correlated with the ratios of interleukin-8/interleukin-4 and interleukin-8/interleukin-10. There were no statistically significant positive correlations between the increase in α2-macroglobulin or soluble α2-macroglobulin receptor and measured clinical variables.ConclusionsWe report for the first time the upregulation of α2-macroglobulin and soluble α2-macroglobulin receptor in tracheal aspirates after cardiopulmonary bypass in infants and children. Soluble α2-macroglobulin receptor correlates with increased α2-macroglobulin and a disproportionate increase in pro-inflammatory to anti-inflammatory cytokine ratios

Correcting the Site Frequency Spectrum for Divergence-Based Ascertainment

Comparative genomics based on sequenced referenced genomes is essential to hypothesis generation and testing within population genetics. However, selection of candidate regions for further study on the basis of elevated or depressed divergence between species leads to a divergence-based ascertainment bias in the site frequency spectrum within selected candidate loci. Here, a method to correct this problem is developed that obtains maximum-likelihood estimates of the unascertained allele frequency distribution using numerical optimization. I show how divergence-based ascertainment may mimic the effects of natural selection and offer correction formulae for performing proper estimation into the strength of selection in candidate regions in a maximum-likelihood setting

Tubular CPT1A deletion minimally affects aging and chronic kidney injury

Kidney tubules use fatty acid oxidation (FAO) to support their high energetic requirements. Carnitine palmitoyltransferase 1A (CPT1A) is the rate-limiting enzyme for FAO, and it is necessary to transport long-chain fatty acids into mitochondria. To define the role of tubular CPT1A in aging and injury, we generated mice with tubule-specific deletion of Cpt1a (Cpt1aCKO mice), and the mice were either aged for 2 years or injured by aristolochic acid or unilateral ureteral obstruction. Surprisingly, Cpt1aCKO mice had no significant differences in kidney function or fibrosis compared with wild-type mice after aging or chronic injury. Primary tubule cells from aged Cpt1aCKO mice had a modest decrease in palmitate oxidation but retained the ability to metabolize long-chain fatty acids. Very-long-chain fatty acids, exclusively oxidized by peroxisomes, were reduced in kidneys lacking tubular CPT1A, consistent with increased peroxisomal activity. Single-nuclear RNA-Seq showed significantly increased expression of peroxisomal FAO enzymes in proximal tubules of mice lacking tubular CPT1A. These data suggest that peroxisomal FAO may compensate in the absence of CPT1A, and future genetic studies are needed to confirm the role of peroxisomal β-oxidation when mitochondrial FAO is impaired