2,814 research outputs found
Turbine blade tip durability analysis
An air-cooled turbine blade from an aircraft gas turbine engine chosen for its history of cracking was subjected to advanced analytical and life-prediction techniques. The utility of advanced structural analysis techniques and advanced life-prediction techniques in the life assessment of hot section components are verified. Three dimensional heat transfer and stress analyses were applied to the turbine blade mission cycle and the results were input into advanced life-prediction theories. Shortcut analytical techniques were developed. The proposed life-prediction theories are evaluated
Component-specific modeling
Accomplishments are described for a 3 year program to develop methodology for component-specific modeling of aircraft hot section components (turbine blades, turbine vanes, and burner liners). These accomplishments include: (1) engine thermodynamic and mission models, (2) geometry model generators, (3) remeshing, (4) specialty three-dimensional inelastic structural analysis, (5) computationally efficient solvers, (6) adaptive solution strategies, (7) engine performance parameters/component response variables decomposition and synthesis, (8) integrated software architecture and development, and (9) validation cases for software developed
Influence of Metabolism on Epigenetics and Disease
Chemical modifications of histones and DNA, such as histone methylation, histone acetylation, and DNA methylation, play critical roles in epigenetic gene regulation. Many of the enzymes that add or remove such chemical modifications are known, or might be suspected, to be sensitive to changes in intracellular metabolism. This knowledge provides a conceptual foundation for understanding how mutations in the metabolic enzymes SDH, FH, and IDH can result in cancer and, more broadly, for how alterations in metabolism and nutrition might contribute to disease. Here, we review literature pertinent to hypothetical connections between metabolic and epigenetic states in eukaryotic cells
GaN directional couplers for integrated quantum photonics
Large cross-section GaN waveguides are proposed as a suitable architecture to
achieve integrated quantum photonic circuits. Directional couplers with this
geometry have been designed with aid of the beam propagation method and
fabricated using inductively coupled plasma etching. Scanning electron
microscopy inspection shows high quality facets for end coupling and a well
defined gap between rib pairs in the coupling region. Optical characterization
at 800 nm shows single-mode operation and coupling-length-dependent splitting
ratios. Two photon interference of degenerate photon pairs has been observed in
the directional coupler by measurement of the Hong-Ou-Mandel dip with 96%
visibility.Comment: 4 pages, 5 figure
Structural analysis demonstration of constitutive and life models
The overall objective of this program is to demonstrate the applicability of NASA-developed advanced constitutive and life damage models for calculating cyclic structural response and crack initiation in selected components of reusable space propulsion systems. The computer model resulting from this program will enable the user to produce an accurate life prediction of hot gas path, life limiting components of propulsion systems such as the space shuttle main engine (SSME). Previously developed computer models addressing constitutive modeling and life damage will be combined in an advanced finite element analysis to generate a sophisticated baseline life prediction program. A material data base will be established for the constitutive and life models parametrically involving temperature, strain range, strain rate, mean strain/stress, and dwell time. The verified computer program will be used to accomplish the life predictions of three SSME critical components as evidence of the model functionality
Who Gives a Trump? Evidence of Framing Effects in Tax Policy
We use a framed survey to measure how associating the name “Trump” with the Tax Cuts and Jobs Act (TCJA) affects people’s satisfaction of said Act. Our research included 72 participant clients from a Volunteer Income Tax Assistants (VITA) program, who were asked to provide baseline data regarding political affiliation and attitudes prior to having tax returns completed. We find that using the name “Trump” with people who self-identify as Republican results in more satisfaction with the Act, whereas, for people with who do not self-identify as Republican, association with the name “Trump” does not precipitate stronger or weaker satisfaction with the Act
Organic residue analysis of Egyptian votive mummies and their research potential
YesVast numbers of votive mummies were produced in Egypt during the Late Pharaonic, Ptolemaic, and Roman
periods. Although millions remain in situ, many were removed and have ultimately entered museum
collections around the world. There they have often languished as uncomfortable reminders of antiquarian
practices with little information available to enhance their value as artefacts worthy of conservation or
display. A multi-disciplinary research project, based at the University of Manchester, is currently
redressing these issues. One recent aspect of this work has been the characterization of natural products
employed in the mummification of votive bundles. Using gas chromatography–mass spectrometry and the
well-established biomarker approach, analysis of 24 samples from 17 mummy bundles has demonstrated
the presence of oils/fats, natural waxes, petroleum products, resinous exudates, and essential oils. These
results confirm the range of organic materials employed in embalming and augment our understanding of
the treatment of votives. In this first systematic initiative of its kind, initial findings point to possible trends in
body treatment practices in relation to chronology, geography, and changes in ideology which will be
investigated as the study progresses. Detailed knowledge of the substances used on individual bundles
has also served to enhance their value as display items and aid in their conservation.RCB is supported by a PhD studentship from the Art and Humanities Research Council (43019R00209). L.M. and S.A.W. are supported by a Leverhulme Trust Research Project Award (RPG-2013-143)
The invisible hand: designing curriculum in the afterward
This paper diffracts a curriculum design workshop via online collaboration of a collective emerging from that event. Through the workshop, involving theory, conceptual art, writing, photography and curriculum planning, and the subsequent sharing of words and images, we move beyond interrogating designs for future subjects to asking how the pedagogical imagination composes both the material and immaterial, the corporeal and incorporeal, within ecologies continually transforming in the process of making. We complicate ‘delivery’ or ‘conduit’ metaphors of education and perceive ‘design’ in co-compositions of human and nonhuman elements, resisting stasis, resisting closure. This workshop paper positions design in the realm of the artist–activist, rather than that of the bureaucrat–technician, and shifts intentionality beyond the invisible and controlling hand of humanism, as curriculum design we might do in the afterwards, rejecting instrumentalism
Mutations in AKAP5 Disrupt Dendritic Signaling Complexes and Lead to Electrophysiological and Behavioral Phenotypes in Mice
AKAP5 (also referred to as AKAP150 in rodents and AKAP79 in humans) is a scaffolding protein that is highly expressed in neurons and targets a variety of signaling molecules to dendritic membranes. AKAP5 interacts with PKA holoenzymes containing RIIα or RIIβ as well as calcineurin (PP2B), PKC, calmodulin, adenylyl cyclase type V/VI, L-type calcium channels, and β-adrenergic receptors. AKAP5 has also been shown to interact with members of the MAGUK family of PSD-scaffolding proteins including PSD95 and SAP97 and target signaling molecules to receptors and ion channels in the postsynaptic density (PSD). We created two lines of AKAP5 mutant mice: a knockout of AKAP5 (KO) and a mutant that lacks the PKA binding domain of AKAP5 (D36). We find that PKA is delocalized in both the hippocampus and striatum of KO and D36 mice indicating that other neural AKAPs cannot compensate for the loss of PKA binding to AKAP5. In AKAP5 mutant mice, a significant fraction of PKA becomes localized to dendritic shafts and this correlates with increased binding to microtubule associated protein-2 (MAP2). Electrophysiological and behavioral analysis demonstrated more severe deficits in both synaptic plasticity and operant learning in the D36 mice compared with the complete KO animals. Our results indicate that the targeting of calcineurin or other binding partners of AKAP5 in the absence of the balancing kinase, PKA, leads to a disruption of synaptic plasticity and results in learning and memory defects
Constraints on a second planet in the WASP-3 system
There have been previous hints that the transiting planet WASP-3 b is
accompanied by a second planet in a nearby orbit, based on small deviations
from strict periodicity of the observed transits. Here we present 17 precise
radial velocity measurements and 32 transit light curves that were acquired
between 2009 and 2011. These data were used to refine the parameters of the
host star and transiting planet. This has resulted in reduced uncertainties for
the radii and masses of the star and planet. The radial-velocity data and the
transit times show no evidence for an additional planet in the system.
Therefore, we have determined the upper limit on the mass of any hypothetical
second planet, as a function of its orbital period.Comment: Accepted for publication in The Astronomical Journa
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