Development of Novel CO2 Adsorbents for Capture of CO2 from Flue Gas

Capturing CO2 emissions generated from fossil fuel-based power plants has received widespread attention and is considered a vital course of action for CO2 emission abatement. Efforts are underway at the Department of Energy’s National Energy Technology Laboratory to develop viable energy technologies enabling the CO2 capture from large stationary point sources. Solid, immobilized amine sorbents (IAS) formulated by impregnation of liquid amines within porous substrates are reactive towards CO2 and offer an alternative means for cyclic capture of CO2 eliminating, to some degree, inadequacies related to chemical absorption by aqueous alkanolamine solutions. This paper describes synthesis, characterization, and CO2 adsorption properties for IAS materials previously tested to bind and release CO2 and water vapor in a closed loop life support system. Tetraethylenepentamine (TEPA), acrylonitrile-modified tetraethylenepentamine (TEPAN), and a single formulation consisting of TEPAN and N, N’-bis(2-hydroxyethyl)ethylenediamine (BED) were individually supported on a poly (methyl methacrylate) (PMMA) substrate and examined. CO2 adsorption profiles leading to reversible CO2 adsorption capacities were obtained using thermogravimetry. Under 10% CO2 in nitrogen at 25°C and 1 atm, TEPA supported on PMMA over 60 minutes adsorbed ~3.2 mmol/g{sorbent} whereas, TEPAN supported on PMMA along with TEPAN and BED supported on PMMA adsorbed ~1.7 mmol/g{sorbent} and ~2.3 mmol/g{sorbent} respectively. Cyclic experiments with a 1:1 weight ratio of TEPAN and BED supported on poly (methyl methacrylate) beads utilizing a fixed-bed flow system with 9% CO2, 3.5% O2, nitrogen balance with trace gas constituents were studied. CO2 adsorption capacity was ~ 3 mmols CO2/g{sorbent} at 40°C and 1.4 atm. No beneficial effect on IAS performance was found using a moisture-laden flue gas mixture. Tests with 750 ppmv NO in a humidified gas stream revealed negligible NO sorption onto the IAS. A high SO2 concentration resulted in incremental loss in IAS performance and revealed progressive degrees of “staining” upon testing. Adsorption of SO2 by the IAS necessitates upstream removal of SO2 prior to CO2 capture

Tutor and Student Assessments of Academic Writing Tutorials: What is "Success"?

The university writing center provides a key support service within the institution, and as such must find ways to evaluate the impact of the instruction they provide. However, many studies of tutorial effectiveness lack adequate analyses of tutorial talk and of both student and tutor interpretations of behavior and outcomes. This study characterizes successful writing tutorials by employing a hybrid mnethodology, interactional sociolinguistics, combining conversation-analytic and ethnographic techniques. Twelve tutorials, six with native speakers of English (NSs) and six with nonnative speakers (NNSs), were analyzed for features such as topic introduction, type and frequency of directives and their mitigation, volubility, overlaps, backchannels, and laughter. By triangulating this analysis with participant interpretations compiled from interview data, a profile of a "successful" tutorial emerged. Associated with perceived success were conversational turn structure, tutor mitigation of directives, simultaneous laughter, affiliative overlaps, and small talk. In addition, symmetrical interpretations of directive forcefulness and tutor "helpfulness" characterized successful tutorials. Implications of the study are both theoretical and practical. Recommendations are made that tutor preparation and in-service training emphasize less idealized, more pragmatic conceptualizations of tutor roles and actions and focus on behaviors demonstrated as constitutive of success

Effects of Mountain Pine Beetle on Fuels and Expected Fire Behavior in Lodgepole Pine Forests, Colorado, USA

In Colorado and southern Wyoming, mountain pine beetle (MPB) has affected over 1.6 million ha of predominantly lodgepole pine forests, raising concerns about effects of MPB-caused mortality on subsequent wildfire risk and behavior. Using empirical data we modeled potential fire behavior across a gradient of wind speeds and moisture scenarios in Green stands compared three stages since MPB attack (Red [1–3 yrs], Grey [4–10 yrs], and Old-MPB [∼30 yrs]). MPB killed 50% of the trees and 70% of the basal area in Red and Grey stages. Across moisture scenarios, canopy fuel moisture was one-third lower in Red and Grey stages compared to the Green stage, making active crown fire possible at lower wind speeds and less extreme moisture conditions. More-open canopies and high loads of large surface fuels due to treefall in Grey and Old-MPB stages significantly increased surface fireline intensities, facilitating active crown fire at lower wind speeds (>30–55 km/hr) across all moisture scenarios. Not accounting for low foliar moistures in Red and Grey stages, and large surface fuels in Grey and Old-MPB stages, underestimates the occurrence of active crown fire. Under extreme burning conditions, minimum wind speeds for active crown fire were 25–35 km/hr lower for Red, Grey and Old-MPB stands compared to Green. However, if transition to crown fire occurs (outside the stand, or within the stand via ladder fuels or wind gusts >65 km/hr), active crown fire would be sustained at similar wind speeds, suggesting observed fire behavior may not be qualitatively different among MPB stages under extreme burning conditions. Overall, the risk (probability) of active crown fire appears elevated in MPB-affected stands, but the predominant fire hazard (crown fire) is similar across MPB stages and is characteristic of lodgepole pine forests where extremely dry, gusty weather conditions are key factors in determining fire behavior

Richard Imlay's Certificate of Removal, 1810

This document certifies that because of his pending marriage to Maria Milnor, Richard Imlay had the permission of the West Hartford Meeting of Friends to leave his meeting "clear of all others on this account&quot. 7.75 X 5.30

The Beach Park kindergarten-primary school.

"Public schools, West Hartford, Conn.": p. [20-26]Plan mounted on p. [2] of cover.At head of title: The Public school department, West Hartford, Connecticut.Mode of access: Internet

INTEGRATION OF MODERN SOFTWARE TOOLS FOR PRODUCT DESIGN

ABSTRACT Engineers, irrespective of their disciplines, need effective tools to comprehensively design, model, synthesize and analyze the design a product. This is often closely followed by the need to fabricate a working prototype. Engineers need useful methodologies and tools that can be used in preparation for manufacturing. These tools need to effectively analyze assembly & disassembly since a good assembly design makes a product les expensive to service, repair and maintain. A suite of well-integrated tools assists designers to create, simulate and test in a comprehensive manner. Modern software tools can be used at each stage to create conceptual designs, simulate part geometries, analyze key parameters, and generate motion paths for efficient manufacturing. This paper presents a set of comprehensive procedures and tools that can easily be incorporated into product design and manufacturing from early design through analysis. They consider assembly and disassembly factors up to and including the creation of a working prototype. Due to environmental regulations, designers must think about the product life cycle, recycling and reuse aspects from the very beginning. There is a continuing need for more efficient and rapid design processes which can best be driven by better tools and techniques