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Sin resume

CANMET Gasifier Liner Coupon Material Test Report

This report provides detailed test results consisting of test data and post-test inspections from Task 1 ''Cooled Liner Coupon Development and Test'' of the project titled ''Development of Technologies and Capabilities for Coal Energy Resources--Advanced Gasification Systems Development (AGSD)''. The primary objective of this development and test program is to verify that ceramic matrix composite (CMC) liner materials planned for use in an advanced gasifier pilot plant will successfully withstand the environments in a commercial gasifier. Pratt & Whitney Rocketdyne (PWR) designed and fabricated the cooled liner test assembly article that was tested in a slagging gasifier at CANMET Energy Technology Center (CETC-O) in Ottawa, Ontario, Canada. The test program conducted in 2006 met the objective of operating the cooled liner test article at slagging conditions in a small scale coal gasifier at CETC-O for over the planned 100 hours. The test hardware was exposed to at least 30 high temperature excursions (including start-up and shut-down cycles) during the test program. The results of the testing has provided valuable information on gasifier startup and required cooling controls in steady state operation of future advanced gasifiers using similar liners. The test program also provided a significant amount of information in the areas of CMC materials and processing for improved capability in a gasifier environment and insight into CMC liner fabrication that will be essential for near-term advanced gasifier projects

Lot-to-lot Variability of BN Grades for Space Electric Propulsion Applications

Historically, several grades of hot pressed hexagonal boron nitride have been used for space electric propulsion applications. This study investigates the material properties of a selection of commercially available boron nitride grades including HP, M26, M, BNXX, and Shapal Hi-M. This work complements data which was presented at JANNAF 2018. The grades selected for this study are of interest because their available billet size is sufficient for space electric propulsion. This research investigates a range of material properties, tailored and focused on enhancing performance, reliability, and economics of electric propulsion thrusters. This work builds upon previous efforts by studying lot-to-lot variability of some of the properties of interest. Coefficient of friction, moisture absorption, moisture sensitivity, hot press directionality, flexural strength, compression strength, elastic modulus, thermal conductivity, thermal emissivity, thermal expansion, density, X-ray diffraction phase, microstructure, and chemical composition were all investigated across two lots of materials to help guide the selection of advanced ceramics. Variability between lots is the critical concern of the study

Coordinated Regulation of Intestinal Functions in C. elegans by LIN-35/Rb and SLR-2

LIN-35 is the sole C. elegans representative of the pocket protein family, which includes the mammalian Retinoblastoma protein pRb and its paralogs p107 and p130. In addition to having a well-established and central role in cell cycle regulation, pocket proteins have been increasingly implicated in the control of critical and diverse developmental and cellular processes. To gain a greater understanding of the roles of pocket proteins during development, we have characterized a synthetic genetic interaction between lin-35 and slr-2, which we show encodes a C2H2-type Zn-finger protein. Whereas animals harboring single mutations in lin-35 or slr-2 are viable and fertile, lin-35; slr-2 double mutants arrest uniformly in early larval development without obvious morphological defects. Using a combination of approaches including transcriptome profiling, mosaic analysis, starvation assays, and expression analysis, we demonstrate that both LIN-35 and SLR-2 act in the intestine to regulate the expression of many genes required for normal nutrient utilization. These findings represent a novel role for pRb family members in the maintenance of organ function. Our studies also shed light on the mechanistic basis of genetic redundancy among transcriptional regulators and suggest that synthetic interactions may result from the synergistic misregulation of one or more common targets

Implementing Peer Review Programs: A Twelve Step Model

Nationally, universities and colleges are expressing increased interest in peer review of teaching in response to public calls for accountability from academe. Further motivation comes from within campuses themselves as they respond to an increasingly non-traditional student body. Based on our experience with a peer observation program at California State University-Dominguez Hills, we identified twelve steps for planning and implementing a peer review process. In this article we discuss each of the twelve steps, presenting a rationale and sharing our experiences

The Social Network of Early American Architecture: A Network Analysis of Early Architectural Training In and Out of the Lowcountry

The contents of this thesis contain research conducted over a 9-month span surrounding the nature of architectural education in the late American Colonial Period, progressing into the Early Republic. Themes such as early European influences, 17th and 18th century art and architecture schools of Dublin, Ireland and Paris, France, and early American drafting schools/apprenticeship societies are analyzed. This paper, first, seeks to document the scholarly dialogue surrounding the ways in which early American architectural practitioners were educated, and in what ways this training was manifest in their physical designs. With a timeframe of approximately 1770 to 1830, 23 practitioners (brick layers, masons, carpenters, architects, military engineers, plaster workers, etc.) and 31 buildings were researched and analyzed. These individuals and built works were catalogued, providing raw data to be extrapolated into a networking software which conveys linkages between different entries. This paper will identify the intricate network of architects, builders, and designers that either taught, trained, or were influenced in some pertinent manner in the late colonial and early republic field of architecture. Additionally, the research highlights connectivity between buildings and people. This study will contribute to the larger dialogue by adding a visual, meta perspective to a field which has been more singularly focused on specific biographies and particular aspects of the early American field

Assessment of lamellar tearing

Information on lamellar tearing is summarized and related to proposed ASME Code requirements. Lamellar tearing is characterized as a complex phenomenon related to poor short transverse ductility and through-thickness strain. The material, welding, and design variables that affect lamellar tearing are shown to be complex and interrelated. The commonly reported tests for assessing material susceptibility are described, with the controversy over their validity being carefully detailed. Although the use of a nondestructive test such as ultrasonic examination is most desirable, a widely applicable test method does not appear to be available. Of the destructive tests, the short transverse tensile reduction-of-area currently offers the most applicable means of assessing material susceptibility. However, because of the importance of matrix toughness, the short transverse Charpy V-notch test should be considered for use as an additional test if acceptance limits are developed. The ultrasonic detection of lamellar tears is susceptible to interpretation errors, which can make it overly conservative and lead to unnecessary repairs. The repair of tears is described as costly, difficult, and sometimes ineffective. Current design requirements appear to preclude any failures during static and fatigue service loads. However, without improvement of short transverse ductility, certain dynamic service loads could cause lamellar tearing failures. Two alternate design paths are recommended to prevent tearing during fabrication or service loading. The current and proposed ASME requirements dealing with lamellar tearing are reviewed and recommendations are made