1,654 research outputs found

    Sarah Logan Wister Starr (1873-1956)

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    Named after her grandmother, Sarah Logan Fisher, Sarah Logan Wister was born in Pierre County, Duncannon, near Philadelphia in 1873. Her Father John Wister descended from the wealthy Wisters of Philadelphia, while her mother descended from James Logan, Secretary to William Penn during the early colonial period.https://digitalcommons.lasalle.edu/people_places/1007/thumbnail.jp

    Integrated Biomass Gasification with Catalytic Partial Oxidation for Selective Tar Conversion

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    Biomass gasification is a flexible and efficient way of utilizing widely available domestic renewable resources. Syngas from biomass has the potential for biofuels production, which will enhance energy security and environmental benefits. Additionally, with the successful development of low Btu fuel engines (e.g. GE Jenbacher engines), syngas from biomass can be efficiently used for power/heat co-generation. However, biomass gasification has not been widely commercialized because of a number of technical/economic issues related to gasifier design and syngas cleanup. Biomass gasification, due to its scale limitation, cannot afford to use pure oxygen as the gasification agent that used in coal gasification. Because, it uses air instead of oxygen, the biomass gasification temperature is much lower than well-understood coal gasification. The low temperature leads to a lot of tar formation and the tar can gum up the downstream equipment. Thus, the biomass gasification tar removal is a critical technology challenge for all types of biomass gasifiers. This USDA/DOE funded program (award number: DE-FG36-O8GO18085) aims to develop an advanced catalytic tar conversion system that can economically and efficiently convert tar into useful light gases (such as syngas) for downstream fuel synthesis or power generation. This program has been executed by GE Global Research in Irvine, CA, in collaboration with Professor Lanny Schmidt's group at the University of Minnesota (UoMn). Biomass gasification produces a raw syngas stream containing H2, CO, CO2, H2O, CH4 and other hydrocarbons, tars, char, and ash. Tars are defined as organic compounds that are condensable at room temperature and are assumed to be largely aromatic. Downstream units in biomass gasification such as gas engine, turbine or fuel synthesis reactors require stringent control in syngas quality, especially tar content to avoid plugging (gum) of downstream equipment. Tar- and ash-free syngas streams are a critical requirement for commercial deployment of biomass-based power/heat co-generation and biofuels production. There are several commonly used syngas clean-up technologies: (1) Syngas cooling and water scrubbing has been commercially proven but efficiency is low and it is only effective at small scales. This route is accompanied with troublesome wastewater treatment. (2) The tar filtration method requires frequent filter replacement and solid residue treatment, leading to high operation and capital costs. (3) Thermal destruction typically operates at temperatures higher than 1000oC. It has slow kinetics and potential soot formation issues. The system is expensive and materials are not reliable at high temperatures. (4) In-bed cracking catalysts show rapid deactivation, with durability to be demonstrated. (5) External catalytic cracking or steam reforming has low thermal efficiency and is faced with problematic catalyst coking. Under this program, catalytic partial oxidation (CPO) is being evaluated for syngas tar clean-up in biomass gasification. The CPO reaction is exothermic, implying that no external heat is needed and the system is of high thermal efficiency. CPO is capable of processing large gas volume, indicating a very compact catalyst bed and a low reactor cost. Instead of traditional physical removal of tar, the CPO concept converts tar into useful light gases (eg. CO, H2, CH4). This eliminates waste treatment and disposal requirements. All those advantages make the CPO catalytic tar conversion system a viable solution for biomass gasification downstream gas clean-up. This program was conducted from October 1 2008 to February 28 2011 and divided into five major tasks. - Task A: Perform conceptual design and conduct preliminary system and economic analysis (Q1 2009 ~ Q2 2009) - Task B: Biomass gasification tests, product characterization, and CPO tar conversion catalyst preparation. This task will be conducted after completing process design and system economics analysis. Major milestones include identification of syngas cleaning requirements for proposed system design, identification and selection of tar compounds and 2 mixtures for use in CPO tests, and preparation of CPO catalysts for validation. (Q3 2009 ~ Q4 2009) - Task C: Test CPO with biomass gasification product gas. Optimize CPO performance with selected tar compounds. Optimize CPO performance with multi-component mixtures. Milestones include optimizing CPO catalysts design, collecting CPO experimental data for next stage kinetic modeling and understanding the effect of relative reactivities on ultimate tar conversion and syngas yields. (Q1 2010 ~ Q3 2010) - Task D: Develop tar CPO kinetic model with CPO kinetic model and modeling results as deliverables. (Q3 2010 ~ Q2 2011) - Task E: Project management and reporting. Milestone: Quarterly reports and presentations, final report, work presented at national technical conferences (Q1 2009 ~ Q2 2011) At the beginning of the program, IP landscaping was conducted to understand the operation of various types of biomass gasifiers, their unique syngas/tar compositions and potential tar mitigation options using the catalytic partial oxidation technology. A process simulation model was developed to quantify the system performance and economics impact of CPO tar removal technology. Biomass gasification product compositions used for performance evaluation tests were identified after literature review and system modeling. A reaction system for tar conversion tests was designed, constructed, with each individual component shaken-down in 2009. In parallel, University of Minnesota built a lab-scale unit and evaluated the tar removal performance using catalytic reforming. Benzene was used as the surrogate compound. The biomass gasification raw syngas composition was provided by GE through system studies. In 2010, GE selected different tar compounds and evaluated the tar removal effectiveness of the CPO catalyst. The catalytic performance was evaluated under different operating conditions, including catalyst geometry, S/C ratio, O/C ratio, GHSV, and N2 dilution. An understanding of how to optimize catalytic tar removal efficiency by varying operating conditions has been developed. GE collaborated with UoMn in examining inorganic impurities effects. Catalysts were pre-impregnated with inorganic impurities commonly present in biomass gasification syngas, including Si, Ca, Mg, Na, K, P and S. UoMn performed catalyst characterization and has acquired fundamental understandings of impurities effect on catalytic tar removal. Based on experimental data and the proposed reaction pathway, GE constructed a model to predict kinetic performance for biomass gasification tar cleanup process. Experimental data (eg. tar conversion, reactor inlet and outlet temperatures, product distribution) at different operating conditions were used to validate the model. A good fit between model predictions and experimental data was found. This model will be a valuable tool in designing the tar removal reactor and identifying appropriate operating conditions. We attended the 2011 DOE Biomass Program Thermochemical Platform Review held in Denver, CO from February 16 to 18 and received very positive comments from the review panel. Further, syngas utility and biomass to power/fuel companies expressed strong interest in our tar removal technology

    The Linkage Between Reporting Quality and Performance in Information Systems Projects

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    Recent research suggests that flawed status reporting is a serious concern in information systems projects. Several investigations have sought to understand the factors that lead project reporters to engage in misreporting. The main motivation for these studies has been the presumption that inaccurate reporting has a significant, negative impact on project performance. However, the linkage between reporting quality and project performance has not been empirically confirmed. The goal of this effort was to answer the following research question: Is reporting quality associated with project outcomes? Our investigation consisted of two complementary survey studies. The first study considered the perceptions of status report senders; the second study considered the perceptions of status report receivers. Both studies showed that reporting quality is positively associated with task and psychological outcomes. Moreover, the second study’s results suggest that reporting quality is also related to organizational outcomes

    The MINI METSAT: A Small Low-Cost Advanced Technology Weather System

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    Spectrum Research, the ITT Aerospace Optical Division and the E-Systems Garland Division describe a system design concept for a 350-lb class small weather satellite system which includes a high-performance meteorological imaging instrument and a completely mobile satellite command, control and weather data processing terminal. The system can be made compatible with either civil or military weather data collection and processing systems, and it is interoperable with existing ground terminals. The system permits collection of high-resolution weather imagery in five spectral bands, and can be launched on a variety of lower-cost small space boosters. Applications discussed include cloud imagery, determination of cloud height, soil moisture and sea surface temperature determination, location of sea ice, and thermal IR imaging of wildfires

    Optimizing Rydberg Gates for Logical Qubit Performance

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    Robust gate sequences are widely used to reduce the sensitivity of gate operations to experimental imperfections. Typically, the optimization minimizes the average gate error, however, recent work in quantum error correction has demonstrated that the performance of encoded logical qubits is sensitive to not only the average error rate, but also the type of errors that occur. Here, we present a family of Rydberg blockade gates for neutral atom qubits that are robust against two common, major imperfections: intensity inhomogeneity and Doppler shifts. These gates outperform existing gates for moderate or large imperfections. We also consider the logical performance of these gates in the context of an erasure-biased qubit based on metastable  171~^{171}Yb. In this case, we observe that the robust gates outperform existing gates for even very small values of the imperfections, because they maintain the native large bias towards erasure errors for these qubits. These results significantly reduce the laser stability and atomic temperature requirements to achieve fault-tolerant quantum computing with neutral atoms. The approach of optimizing gates for logical qubit performance may be applied to other qubit platforms.Comment: v3: Added discussion of AC-Stark shifts; v2: Updated reference

    Police well-being interventions: Using awe narratives to promote resilience

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    The well-being of the police workforce needs to be a priority as law enforcement agencies continue to adapt to emerging issues while serving their communities. Reflecting and sharing awe narratives, as well as being exposed to the awe stories of others, can enhance their resilience and support their overall well-being. This article, which is based on a special lecture given during the Law Enforcement and Public Health Conference held May 21–24, 2023, at Umea University in Umea, Sweden, uses phenomenology to examine the awe stories and experiences of police participants who took part in a resilience program as well as feedback during the conference discussion. The analysis demonstrates that awe narratives can serve as a gateway to other resilience practices including cognitive reappraisal, emotional intelligence, gratitude, humility, finding meaning and purpose in life, mindfulness, optimism and hope, self-compassion, self-efficacy, social connection, and managing uncertainty and ambiguity. Based on the findings, awe narratives should be considered for implementation in future police mental health and resilience training as an evidence-based practice to support the police workforce

    Enhancing resilience: An interpretative phenomenological analysis of The Awe Project

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    Awe is a complex emotion often associated with experiencing multiple other positive emotions during a captivating and immersive experience. Engaging in awe experiences contributes to enhancing an individual’s personal resilience and wellbeing. Moreover, the benefits of experiencing awe transcend the individual, as it has been described as a self-transcendent emotion provoking concern beyond the self. Using an Interpretative Phenomenological Analysis (IPA) methodology, this exploratory paper evaluates the impact of The Awe Project, an online resilience and well-being program that can be accessed on mobile devices, on a specific cohort of participants. Data analysis consisted of examining participant post-program surveys and comments made during the program. Results indicate the program supported participants’ resilience and well-being through evoking awe and using other mindfulness and resilience practices, such as having a sense of agency, cognitive reappraisal, connectedness, controlled breathing, gratitude and appreciation, meaning and purpose in life, and optimism and prospection

    Enhancing resilience during the COVID-19 pandemic: A thematic analysis and evaluation of the warr;or21 program

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    The novel coronavirus (COVID-19) has negatively impacted the world in a variety of ways. Thousands have died, many more have fallen ill, and it continues to have a disastrous impact on the global economy. The virus has also significantly impacted people’s well-being and their mental health, where the effects are expected to continue long after businesses begin to re-open. Promoting resilience and positive mental health coping strategies are, therefore, vital to assisting people as this pandemic continues and long after a sense of “normalcy” returns. This paper, a program analysis of warr;or21, a resilience program, utilizes qualitative research methods to share the insights of participants who completed the program during the COVID-19 pandemic. The warr;or21 program was designed initially to enhance resilience in law enforcement and other first responders and has since been adapted for the general public. The data reveals that, from the perspective of the participants, warr;or21 has helped many of them cope and manage positively, specifically amid the COVID-19 pandemic. Thus, the warr;or21 program has the potential to help enhance people’s resilience and mental health during future adverse events as well as to be used proactively to further develop a person’s overall mental health and resilience

    Intelligent Deployment of Forest Road Graders

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    Road grading is the most common maintenance activity performed on forest roads. Reducing grading cost could release resources for other maintenance needs, ideally resulting in a better maintained road system. A combinatorial optimization method, tabu search, is combined with two local search procedures to generate efficient grading routes. Determining the optimal grading route is modeled as an extension of the Mixed Rural Postman Problem (MRPP), adapted to include a daily operating time limit and different traversal/service times. The objective was to minimize total operating time, a proxy for grading cost. The heuristic was tested on both artificial and actual forest road networks, and computational results are presented. The heuristic demonstrates the ability to generate efficient and feasible grader routes
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