Gaseous emissions from herding agent-mediated in-situ burning for Arctic oil spills

Thesis (M.S.) University of Alaska Fairbanks, 2017If a crude oil spill were to occur in partially ice-covered waters, many of the response tactics typically utilized in either open water or completely ice-covered conditions would become inefficient. In such situations, in-situ burning (ISB) can prove to be an efficient response tool; herding agent application is one available approach to thicken an oil slick. This study assessed the impacts on air quality following ISB tests on crude oil, in combination with herding agents, in partially ice-infested waters. The research focused on measuring downwind concentrations of respirable particulate matter (PM₂.₅) and seven different combustion gasses (CO, CO₂, NO, NO₂, NOx, SO₂, and VOCs) during five ISB events, with sampling instruments placed in-plume and 6-12 m away from the source area. The study also investigated if the utilized herding agent was detectable in the airborne plume. Findings include: 1) Concentrations of particulate matter (<2.5μm in diameter), SO₂, and CO were found to significantly (P <0.01) exceed various exposure limits and air quality standards, while the remaining compounds measured were significantly (P <0.01) below established exposure limits. Also, downwind, in the smoke plume, measured concentrations of SO₂, NOx, and total VOCs were higher than found in previous studies. It should be noted that instrument and methods not specifically approved by the U.S. Environmental Protection Agency, Occupational Safety and Health Administration, and the National Institute for Occupational Safety and Health were utilized during this study; 2) GC/MS analysis of aerosol samples collected utilizing a flow meter and carbon sorbent tubes in the smoke plume; the Siltech OP-40 silicone based functional group of the applied herding agent was not detected in the collected samples analyzed using GC/MS. Future research should include additional scalability studies where the concentrations of particulate matter and various combustion gasses are compared to modeled concentrations using computer software. Additional research is also needed to find a cost-effective method to decrease the amount of particulate matter during an in-situ burn. It is also recommended that guidance specific for conducting in-situ burns of crude oil or refined petroleum products in the Arctic is written and published by regulatory agencies, so the industry can rapidly make plans and propose such tactics if an incident did occur where mechanical or other non-mechanical response tactics are not feasible

The optimal way to increase cash holdings: From a market perspective - a study of various ways to increase cash holdings and their implications on market value during economic boom and recession

The main purpose of this paper is to identify a relationship between different approaches to accumulate cash and companies’ market values between periods of different economic conditions. Our thesis contributes with information that helps firm managers decide how to increase cash holdings. We come to the conclusion that firms increase their cash holdings by decreasing investments in research and development, reduce capital expenditures and diminish dividend payments. Further, we also come to the conclusion that the market values these cash accumulating approaches differently depending on current economic condition. Cuts in dividends are kindly looked upon by the market throughout the periods, meanwhile cuts in capital expenditures are most favorable during the crisis and cuts in research and development has the least negative impact on the market value in the post crisis years

A Method to Measure the Permeability of Dry Fiber Mats

Close to the finalization of the medium density fiberboard process, a fairly thick bed of loosely entangled fibers is compressed in a belt-press to often less than a tenth of its original unstressed thickness. This single unit operation is very important to consider when the manufacturing process of the boards is to be optimized. Despite this, there is a lack of knowledge of the interaction between the fiber mat strength and how the fluid flows through it, i.e. de-aeration. Thus, it is of greatest importance to find reliable methods for studying this stage of the manufacturing process. Following this quest, a method is developed with which the gas permeability of fiber mats can be measured. The method offers the potential to measure the permeability at different flow rates and thus at arbitrary pressure gradients through the material. The method is successfully validated with a porous reference material consisting of polymer spheres, and it is shown that the flow follows Darcy's law at the flow rates of interest. Finally, the method is demonstrated by a presentation of permeability measurements on fiber mats consisting of spruce fibers

Collision Dynamics and Solvation of Water Molecules in a Liquid Methanol Film

Environmental molecular beam experiments are used to examine water interactions with liquid methanol films at temperatures from 170 K to 190 K. We find that water molecules with 0.32 eV incident kinetic energy are efficiently trapped by the liquid methanol. The scattering process is characterized by an efficient loss of energy to surface modes with a minor component of the incident beam that is inelastically scattered. Thermal desorption of water molecules has a well characterized Arrhenius form with an activation energy of 0.47{\pm}0.11 eV and pre-exponential factor of 4.6 {\times} 10^(15{\pm}3) s^(-1). We also observe a temperature dependent incorporation of incident water into the methanol layer. The implication for fundamental studies and environmental applications is that even an alcohol as simple as methanol can exhibit complex and temperature dependent surfactant behavior.Comment: 8 pages, 5 figure

Harmonization of Neuroticism and Extraversion phenotypes across inventories and cohorts in the Genetics of Personality Consortium : an application of Item Response Theory

Peer reviewe

Meta-analysis of Genome-Wide Association Studies for Extraversion: Findings from the Genetics of Personality Consortium

Extraversion is a relatively stable and heritable personality trait associated with numerous psychosocial, lifestyle and health outcomes. Despite its substantial heritability, no genetic variants have been detected in previous genome-wide association (GWA) studies, which may be due to relatively small sample sizes of those studies. Here, we report on a large meta-analysis of GWA studies for extraversion in 63,030 subjects in 29 cohorts. Extraversion item data from multiple personality inventories were harmonized across inventories and cohorts. No genome-wide significant associations were found at the single nucleotide polymorphism (SNP) level but there was one significant hit at the gene level for a long non-coding RNA site (LOC101928162). Genome-wide complex trait analysis in two large cohorts showed that the additive variance explained by common SNPs was not significantly different from zero, but polygenic risk scores, weighted using linkage information, significantly predicted extraversion scores in an independent cohort. These results show that extraversion is a highly polygenic personality trait, with an architecture possibly different from other complex human traits, including other personality traits. Future studies are required to further determine which genetic variants, by what modes of gene action, constitute the heritable nature of extraversion

Meta-analysis of genome-wide association studies for extraversion:Findings from the Genetics of Personality Consortium

Extraversion is a relatively stable and heritable personality trait associated with numerous psychosocial, lifestyle and health outcomes. Despite its substantial heritability, no genetic variants have been detected in previous genome-wide association (GWA) studies, which may be due to relatively small sample sizes of those studies. Here, we report on a large meta-analysis of GWA studies for extraversion in 63,030 subjects in 29 cohorts. Extraversion item data from multiple personality inventories were harmonized across inventories and cohorts. No genome-wide significant associations were found at the single nucleotide polymorphism (SNP) level but there was one significant hit at the gene level for a long non-coding RNA site (LOC101928162). Genome-wide complex trait analysis in two large cohorts showed that the additive variance explained by common SNPs was not significantly different from zero, but polygenic risk scores, weighted using linkage information, significantly predicted extraversion scores in an independent cohort. These results show that extraversion is a highly polygenic personality trait, with an architecture possibly different from other complex human traits, including other personality traits. Future studies are required to further determine which genetic variants, by what modes of gene action, constitute the heritable nature of extraversion

Genome-wide interaction study of a proxy for stress-sensitivity and its prediction of major depressive disorder

Individual response to stress is correlated with neuroticism and is an important predictor of both neuroticism and the onset of major depressive disorder (MDD). Identification of the genetics underpinning individual differences in response to negative events (stress-sensitivity) may improve our understanding of the molecular pathways involved, and its association with stress-related illnesses. We sought to generate a proxy for stress-sensitivity through modelling the interaction between SNP allele and MDD status on neuroticism score in order to identify genetic variants that contribute to the higher neuroticism seen in individuals with a lifetime diagnosis of depression compared to unaffected individuals. Meta-analysis of genome-wide interaction studies (GWIS) in UK Biobank (N = 23,092) and Generation Scotland: Scottish Family Health Study (N = 7,155) identified no genome-wide significance SNP interactions. However, gene-based tests identified a genome-wide significant gene, ZNF366, a negative regulator of glucocorticoid receptor function implicated in alcohol dependence (p = 1.48x10-7; Bonferroni-corrected significance threshold p < 2.79x10-6). Using summary statistics from the stress-sensitivity term of the GWIS, SNP heritability for stress-sensitivity was estimated at 5.0%. In models fitting polygenic risk scores of both MDD and neuroticism derived from independent GWAS, we show that polygenic risk scores derived from the UK Biobank stress-sensitivity GWIS significantly improved the prediction of MDD in Generation Scotland. This study may improve interpretation of larger genome-wide association studies of MDD and other stress-related illnesses, and the understanding of the etiological mechanisms underpinning stress-sensitivity