Development and Application of an Oxidation Flow Reactor to Study Secondary Organic Aerosol Formation from Ambient Air

Palm, Brett Brian University of Colorado at Boulder ProQuest Dissert 2017 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Secondary organic aerosols (SOA) in the atmosphere play an important role in air quality, human health, and climate. However, the sources, formation pathways, and fate of SOA are poorly constrained. In this dissertation, I present development and application of the oxidation flow reactor (OFR) technique for studying SOA formation from OH, O3, and NO3 oxidation of ambient air. With a several-minute residence time and a portable design with no inlet, OFRs are particularly well-suited for this purpose. I first introduce the OFR concept, and discuss several advances I have made in performing and interpreting OFR experiments. This includes estimating oxidant exposures, modeling the fate of low-volatility gases in the OFR (wall loss, condensation, and oxidation), and comparing SOA yields of single precursors in the OFR with yields measured in environmental chambers. When these experimental details are carefully considered, SOA formation in an OFR can be more reliably compared with ambient SOA formation processes. I then present an overview of what OFR measurements have taught us about SOA formation in the atmosphere. I provide a comparison of SOA formation from OH, O3, and NO3 oxidation of ambient air in a wide variety of environments, from rural forests to urban air. In a rural forest, the SOA formation correlated with biogenic precursors (e.g., monoterpenes). In urban air, it correlated instead with reactive anthropogenic tracers (e.g., trimethylbenzene). In mixed-source regions, the SOA formation did not correlate well with any single precursor, but could be predicted by multilinear regression from several precursors. Despite these correlations, the concentrations of speciated ambient VOCs could only explain approximately 10-50% of the total SOA formed from OH oxidation. In contrast, ambient VOCs could explain all of the SOA formation observed from O3 and NO3 oxidation. Evidence suggests that lower-volatility gases (semivolatile and intermediate-volatility organic compounds; S/IVOCs) were present in ambient air and were the likely source of SOA formation that could not be explained by VOCs. These measurements show that S/IVOCs likely play an important intermediary role in ambient SOA formation in all of the sampled locations, from rural forests to urban air.

Phoning it in: Self-service, telecommunications and new consumer labor

Palm, Michael New York University 2010 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Technologies are often designed and manufactured in ways that allow the tasks and responsibilities of paid employees to be systematically reassigned to their customers. Jobs are usually lost when customer services are reorganized into self-service, but the work seldom, if ever, disappears. When telephone operators, bank tellers and other customer service jobs are eliminated, what happens to the work? How is it done, by whom, and with what degrees of acceptance, enthusiasm and ingenuity? To answer these questions, this dissertation describes the historical development of telephone infrastructure, networks and protocols in the United States, and analyzes them as means by which employers and service providers have transferred a substantial amount of work from their employees to their customers. Whenever we log on to a network today, for example, we begin by performing the basic technological function of establishing a telecom connection of one sort or another, whether or not we pause to recall that these connections originally were the job of telephone (and telegraph) operators to establish. Telephony was originally sold as a service -- not a technology -- and telephone connections were the provenance of operators. The most fundamental historical observation resulting from my dissertation research is that people had to grow accustomed to placing telephone calls on their own, without assistance from operators, before the telephone could mature and expand into the American self-service technology par excellence. After describing, in the introduction and first chapter, the arrival of self-service (and the telephone) in everyday American life, this dissertation elaborates the development of the telephone as a self-service technology. In the middle chapters I present case studies of the rotary dial and the touch-tone keypad as the foundational and pivotal remediations, respectively, of the home telephone into a multi-purpose (and all-American) self-service technology. The fourth and final chapter presents a case study of the automated teller machine (ATM), describing it as descended, in part, from the telephone, as well as a transformative self-service technology in its own right. The conclusion explores cell phones as a next chapter in the future of self-service and its telemediation.

Immune Responses to Noxious Xenobiotics

Palm, Noah Wolcott Yale University 2011 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The innate immune system senses the presence of infection through detection of pathogen associated molecular patterns by pattern recognition receptors (PRRs) and instructs the adaptive immune system on when, how and to which antigens to respond. We examined innate and adaptive immune responses to two classes of non-infectious antigens---haptenated proteins and venoms. Haptenated proteins are used to elicit T-dependent antibody responses. Although adaptive responses to many infections and immunizations require Toll-like receptor (TLR)-dependent innate instruction, we found that T helper cell and antibody responses to haptenated proteins were independent of known pattern recognition receptors, including TLRs. Therefore, haptenated proteins either bypass the requirement for innate instruction of adaptive immunity, or trigger an alternative innate immune sensing pathway. Venoms consist of complex mixtures of toxic components delivered to their victims via bites or stings, and are used by various animals (e.g., insects and snakes) for defense and predation. Venoms are also well known as allergens. Notably, many classes of allergens, including venoms, are highly noxious. We hypothesized that the innate immune system might sense these 'noxious xenobiotics' via detection of their toxic activities and instruct innate and adaptive immune responses that would promote their detoxification and clearance. We found that bee venom and the cell-lytic peptide melittin from bee venom could trigger activation of the NLRP3-inflammasome, leading to Caspase 1 activation and IL-1beta secretion. Strikingly, Caspase 1-deficient mice were hypersensitive to the toxic effects of bee and snake venom, suggesting that an inflammasome-dependent immune response can promote venom detoxification and clearance. Bee venom and bee venom phospholipase A2 (bvPLA2) also induced IgE production and a T helper type-2 (Th2) response. These responses were independent of TLRs and Caspase-1. However, bee venom and bvPLA2 could stimulate basophil IL-4-production in vitro, and basophil depletion attenuated the Th2 response to bvPLA2 in vivo . Taken together, these data suggest that the innate immune system can sense noxious xenobiotics, such as venoms, via detection of their toxic activities and can enhance resistance to their noxious effects. The detection of venoms also results in the instruction of Th2 and IgE responses, which may promote detoxification and clearance (as well as condition future avoidance) of noxious xenobiotics by mediating an allergic response. These data demonstrate a new role for the immune response that is separate from defense against infection and suggest a potential reinterpretation of the purpose of the allergic response.

Comprehensive system indices, constellations, and supplemental aggression ratings for the Rorschach Inkblot method: Reliability and validity in a child and adolescent outpatient sample

Palm, Jacob A Fordham University 2005 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The current study had two primary objectives. The first objective was to examine the reliability and validity of the Comprehensive System (CS, Exner, 1986, 1993) for the Rorschach Inkblot Test in a population of children and adolescents treated over the past decade at a not-for-profit community mental health center in urban southern California. This examination included investigation of CS interrater reliability, convergent and discriminant validity, criterion validity, and diagnostic utility. The second objective of the current study was to examine the additive clinical utility of scoring the Supplemental Aggression Rating Scales (SAR, Meloy & Gacono, 1992; Gacono & Meloy, 1994) in the prediction of aggression in children and adolescents, as compared to sole utilization of life historical variables identified as risk factors in the first comprehensive Report to the Surgeon General regarding Youth Violence (U.S. Public Health Service, 2001). The study utilized archival methodology, reviewing psychological test data in comparison to recorded life history variables contained in client clinical charts. The criterion measure utilized was the Aggression Chart Rating Scale-Revised (ACRS-R). Following statistically acceptable interrater reliability analyses, correlational and multiple regression analyses were performed. In general, the current study suggests that while the Rorschach Inkblot Method can be scored reliably by trained raters according to the Comprehensive System, there is much research left to be done regarding specific indices and their meanings. Similar to past research, the CS constellations demonstrated little relationship to diagnosis as currently viewed under DSM-IV (American Psychiatric Association, 1994) categorization. The CS constellations similarly failed to significantly converge with the Roberts Apperception Test for Children (RAT-C, McArthur & Roberts, 1982), which is thought to measure psychopathology in children and adolescents. In consideration of the SAR, the results of the current study were significantly divergent from previously published research, suggesting little additive or incremental clinical utility in their use as compared to life history data commonly available to clinicians in the course of daily practice. Theoretical and clinical implications are offered in light of the first comprehensive Report to the Surgeon General regarding Youth Violence and the current controversy surrounding continued use of the Comprehensive System.

A multilevel analysis comparing neighborhood and school effects on elementary school achievement in one school district in New Mexico

Palm-Aitchison, Rebel The University of New Mexico 2005 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Over the last couple of decades, school effects research has found that the intake characteristics of a schools' catchment area are consistent and robust predictors of student achievement in that school. Neighborhood studies have also found that the context in which individuals are embedded matters to individual outcomes. Recent advances in statistical techniques allow the hierarchical nature of these different units of analysis---individuals and the ecological units in which they're embedded---to be modeled concurrently. This study compared mirror versions of school and neighborhood models using HLMRTM6 to predict standardized test scores of a cohort of elementary school students from 3rd through 5th grades with both school and neighborhood variables. The goals were to demonstrate that (1) census variables could be used to model neighborhood characteristics instead of approximating intake characteristics with the usual aggregated student characteristics, and (2) these neighborhood variables would be robust predictors of student and school achievement. A third goal emerged---to contribute to understanding school accountability. In this study, approximately 72 percent of the variance in the outcome was attributable to factors over which schools have little or no control: individual and neighborhood characteristics. Although both models were robust, the neighborhood model captured slightly more variance than the school model which demonstrates the utility of census data for capturing neighborhood context. Implications for future school effects and neighborhood effects research are discussed.

Cost-effective conservation programs to enhance ecosystem services in agricultural landscapes

Palm-Forster, Leah Harris Michigan State University 2015 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Conservation programs promote voluntary adoption of agricultural management practices that can mitigate nutrient runoff and generate ecosystem services (ES) in working landscapes. However, despite billions of dollars spent on conservation programs annually, agricultural pollution remains a persistent problem. Using experimental auctions and behavioral models that integrate economic and ecological information, the first two essays of this dissertation identify how conservation programs can be designed to cost-effectively improve aquatic ecosystem services in agricultural landscapes. The third essay estimates some of the benefits from successful conservation programs in terms of averted welfare loss when beach closures are caused by harmful algal blooms resulting from agricultural nutrient runoff. Essay one analyzes farmer preferences for different types of conservation incentives, including payments, green insurance, tax credits, and price premiums. I estimate how the type of incentive offered affects farmer willingness to adopt agricultural management practices that reduce nutrient runoff from cropland in the Maumee watershed to help abate damaging algal blooms in western Lake Erie. I evaluate how the cost-effectiveness of various incentive types depends on farmer willingness to enroll in the program and the level of payment or other financial incentive they require. In general, the most cost-effective contracts are ones that spatially target high priority areas of the watershed and offer financial incentives with low transaction costs for farmers such as payments and tax credits. Essay two identifies barriers and deterrents to participation in conservation auctions and explores how participation affects cost-effectiveness. Outcomes are reported from two conservation auctions that were implemented in two counties in NW Ohio as part of an ongoing effort to reduce harmful algal blooms in Lake Erie. Bids were evaluated based on their expected environmental benefits---specifically their estimated reductions in bioavailable phosphorus loadings to Lake Erie as predicted by biophysical models. Only 1% of landowners submitted bids. A follow-up survey revealed three barriers to bidding: knowledge about the auction program, ineligibility, and transaction costs of participation. Three policy scenarios are simulated using a mathematical programming model to demonstrate how transaction costs reduce farmer participation and erode cost-effectiveness of conservation auctions relative to uniform payment programs. Cost-effectiveness is greatest in policies with low transaction costs that can spatially target environmentally vulnerable parcels. Essay three uses two benefit transfer approaches to estimate welfare losses from beach closures in Lake Erie caused by harmful algal blooms. I identify how estimates differ between the two transfer approaches---value transfer and function transfer---and evaluate conditions under which the more time-consuming and data-intensive function transfer is worth the effort compared to a simple value transfer. In this study, benefit function transfer was essential to estimate beach demand (trips) and demand elasticity (change in trips), but when evaluating individual beach closures with known trip demand, the function transfer and value transfer yielded similar results for individual beach closures. Results from the two transfer methods deviated (up to 106%) when multiple beaches closed because value transfer did not account for the loss of beach substitutes. This result emphasizes the importance of using transfer methods that account for changes in trip demand to estimate welfare loss from regional beach closures.

Ultrathin Coatings for Enhanced Durability in (Photo)electrochemical Hydrogen Production

Palm, David William ProQuest Dissertations & Theses Stanford Universit 2020 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

With society transitioning from fossil fuel energy to renewable energy, there is an increasing need for robust means of storing the energy captured from these more variable resources. One concept for storing the vast, effectively limitless solar energy resource is called solar water splitting—a photoelectrochemical (PEC) process that produces hydrogen fuel from one of earth's most abundant chemical feedstocks. This work focuses on developing ultrathin coatings that enhance the durability of these PEC hydrogen-producing systems in the acidic aqueous electrolytes commonly employed for this reaction.We investigated the canonical PEC protective coating, titania (TiO2), to understand the reason that heat treatments in oxygen-containing environments improve the durability of (photo)electrochemical devices assembled with these ultrathin coatings. In electrocatalytic hydrogen production experiments, conductive silicon substrates coated with a 5-nm thick TiO2 coating and a layer of Pt showed dramatic improvements in both their activity (in terms of voltage required to achieve a set rate of hydrogen production) and durability when the TiO2 had been heat treated at temperatures of 200-500°C, with 500°C engendering the best performance by both metrics. In situ grazing incidence x-ray diffraction experiments under heating conditions in air revealed two crystallization regimes for these ultrathin TiO2. From temperatures about 250-400°C, the crystallization from amorphous to the anatase phase of TiO2 resembles the nucleation of anatase crystallites. From temperatures about 420-450°C, there appears to be growth of these crystallites to encompass increasing fraction of the film in the anatase phase.With ultrathin TiO2 requiring this advanced processing to meet durability requirements, we sought to explore another transition metal oxide that we predicted to have better intrinsic stability—tungsten oxide (WO3). WO3 coatings were synthesized by atomic layer deposition (ALD), a process known to yield highly conformal films with a high degree of thickness control. When utilized as coating on conductive silicon substrates with a Pt catalyst overlayer, a 4 nm WO3 film imparted the best durability by sustaining efficient hydrogen evolution over 15 h of durability testing. A photoactive device prepared on semiconducting silicon with a 4 nm WO3 film and Pt catalyst layer produced a light-driven voltage of 0.31 V and sustained a photocurrent density (which is proportional the rate of hydrogen production) of -20 mA cm-2 for 22 h of PEC durability testing.Adapting this ALD-type WO3 deposition to a copper gallium selenide (CuGa3Se5) semiconducting light absorbing film led to a CuGa3Se5 [vertical line] WO3 [vertical line] Pt devices that sustained continuously illuminated PEC hydrogen production over six weeks of durability testing. The most-durable device established a new durability milestone for any non-silicon device by passing 21,490 C cm-2 of charge, which is proportional to the total amount of hydrogen produced.Tungsten sulfide (WSx) films were synthesized from ALD-prepared WO3 films and investigated for their electrocatalytic activity and durability. Through x-ray photoelectron spectroscopy (XPS), the films synthesized at temperatures of 250-450°C were shown to be composed of WS2, with the 350-450°C-treated samples exhibiting some WS3 character that increased with increasing temperature. The WSx coating synthesized at 250°C demonstrated some electrocatalytic activity for hydrogen production, which was largely absent with the 350-450°C synthesized films, but degraded dramatically after 18 h of durability testing. The 350°C-synthesized WSx film was adapted to a photoactive silicon device with a catalytic Pt overlayer, and showed reasonable PEC hydrogen production activity but poor durability.

Uncovering Performance in Medieval Scandinavia: A Survey and Analysis of Medieval Performance in Scandinavia

La Palm, Kimberly Jo ProQuest Dissertations & Theses University of Cali 2016 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The academic study of Scandinavian culture and Scandinavian literature has long ignored the engagement of the Nordic nations in the tradition of drama and performance in medieval Europe. Early drama history scholars like Sophus Birket Smith and G.E. Klemming made claims about a perceived lack of practice based on limited sources and most of the scholars who followed them have accepted those claims as valid. Unfortunately, Birket Smith and Klemming were working with an incomplete corpus and nineteenth-century ideas about what constituted "drama". Later scholars such as Frederick and Lise-Lone Marker and Terry Gunnell have made great headway in expanding the concept of drama and performance within the field of Scandinavian studies while also clarifying what texts we do, in fact, still have. The work that has been done, however, is still far below the level of depth and complexity of work that has been done with the study of medieval drama and performance in other language traditions. It is my goal to gather and present a more complete corpus of early Scandinavian drama along with an analysis of the work that has been done to date. The goal of this dissertation is to offer an overview of this long misunderstood tradition and to introduce the international scholarly community to a revised corpus of medieval drama running the gamut from liturgical drama to secular comedy.