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User interface development and software environments : the Chiron-1 system
User interface development systems for software environments have to cope with the broad, extensible and dynamic character of such environments, must support internal and external integration, and should enable various software development strategies. The Chiron-1 system adapts and extends key ideas from current research in user interface development systems to address the particular demands of software environments. Important Chiron-1 concepts are: separation of concerns, dynamism, and open architecture. We discuss the requirements on such user interface development systems, present the Chiron-1 architecture and a scenario of its usage, detail the concepts it embodies, and report on its design and prototype implementation
2-C-Cyclohexyl-2,3-O-isopropylideneerythrofuranose
In the title compound, C13H22O4, the acetonide ring adopts an envelope conformation with one of the O atoms as the flap atom, whereas a twisted conformation is found for the furanose ring. Centrosymmetric eight-membered {⋯OCOH}2 synthons involving the hydroxy H and acetonide O atoms are found in the crystal structure. These are linked into a supramolecular chain in the a-axis direction via C—H⋯O contacts
2,3-O-Isopropylidene-3-C-phenylerythrofuranose
The title compound, C13H16O, comprises two fused five-membered rings. Each ring has an envelope conformation, with the ether O atom in the furanose ring, and the CMe2 atom in the acetonide ring as the flap atoms. In the crystal, centrosymmetrically related molecules associate via hydroxy–ether O—H⋯O hydrogen bonds and the resulting dimers are linked into a supramolecular chain with a flattened topology via C—H⋯Ohydroxy contacts, and aligned in the a-axis direction
Di-tert-butyl (2R,3R)-2-{[(2E)-3-(4-acetyloxy-3-methoxyphenyl)prop-2-enoyl]oxy}-3-hydroxybutanedioate
In the title molecule, C24H32O10, one tert-butyl ester group is folded towards the central benzene ring while the other is directed away. The acetyl group is almost perpendicular to the benzene ring to which it is connected [C—C—O—C torsion angle = 90.4 (12)°]. The conformation about the ethene bond [1.313 (7) Å] is E. The atoms of the benzene ring and its attached ester group and part of the hydroxy tert-butyl ester side chain are disordered over two sets of sites in a 50:50 ratio. Linear supramolecular chains along the a axis mediated by hydroxy–carbonyl O—H⋯O hydrogen bonds feature in the crystal packing. The same H atom also partakes in an intramolecular O—H⋯O interaction
2-(2-Methylnaphtho[2,1-b]furan-1-yl)acetic acid
In the title molecule, C15H12O3, the two six-membered and one five-membered fused-ring system is almost planar and the CH2C(=O)OH residue is essentially orthogonal to it. In the crystal structure, centrosymmetric dimers are formed via the carboxylic acid {⋯O=C—O—H}2 synthon
Methyl 2-(5-bromo-2-methylnaphtho[2,1-b]furan-1-yl)acetate
The three fused six-, six- and five-membered rings in the title compound, C16H13BrO3, are coplanar, the CH2C(=O)OCH3 residue being twisted out of this plane [dihedral angle = −26.9 (4)°]. Centrosymmetric dimers are found in the crystal structure stabilized by C—H⋯O interactions involving the furan O atom
RSRM Segment Train Derailment and Recovery
On May 2, 2007, a freight train carrying segments of the space shuttle's solid rocket boosters derailed in Myrtlewood, Alabama, after a rail trestle collapsed. The train was carrying Reusable Solid Rocket Motors (RSRM) 98 center and forward segments (STS-120) and RSRM 99 aft segments (STS-122). Initially, it was not known if the segments had been seriously damaged. Four segments dropped approximately 10 feet when the trestle collapsed and one of those four rolled off the track onto its side. The exit cones and the other four segments, not yet on the trestle, remained on solid ground. ATK and NASA immediately dispatched an investigation and recovery team to determine the safety of the situation and eventually the usability of the segments and exit cones for flight. Instrumentation on each segment provided invaluable data to determine the acceleration loads imparted into each loaded segment and exit cone. This paper details the incident, recovery plan and the team work that created a success story that ended with the safe launch of STS120 using the four center segments and the launch of STS122 using the Aft exit cones assemblies
On the Evolution Equation for Magnetic Geodesics
In this paper we prove the existence of long time solutions for the parabolic
equation for closed magnetic geodesics.Comment: In this paper we prove the existence of long time solutions for the
parabolic equation for closed magnetic geodesic
1,4-Di-tert-butyl (2R,3R)-2-({(2E)-3-[4-(acetyloxy)phenyl]prop-2-enoyl}oxy)-3-hydroxybutanedioate
The title compound, C23H30O9, has an approximate T-shape with the tert-butyl ester groups lying either side of the benzene ring. The acetyl group is almost perpendicular to the benzene ring to which it is connected [C—C—O—C torsion angle = −106.7 (3)°]. The conformation about the C=C double bond [1.331 (4) Å] is E. Linear supramolecular chains along the a axis mediated by hydroxy–carbonyl O—H⋯O hydrogen bonds feature in the crystal packing. The same H atom is also involved in an intramolecular O—H⋯O interaction
Shallow Rupture Propagation of Pleistocene Earthquakes Along the Hurricane Fault, UT, Revealed by Hematite (U-Th)/He Thermochronometry and Textures
The material properties and distribution of faults above the seismogenic zone promote or inhibit earthquake rupture propagation. We document the depths and mechanics of fault slip along the seismically active Hurricane fault, UT, with scanning and transmission electron microscopy and hematite (U-Th)/He thermochronometry. Hematite occurs as mm-scale, striated patches on a \u3e10 m2 thin, mirror-like silica fault surface. Hematite textures include bulbous aggregates and cataclasite, overlain by crystalline Fe-oxide nanorods and an amorphous silica layer at the slip interface. Textures reflect mechanical, fluid, and heat-assisted amorphization of hematite and silica-rich host rock that weaken the fault and promote rupture propagation. Hematite (U-Th)/He dates document episodes of mineralization and fault slip between 0.65 and 0.36 Ma at ∼300 m depth. Data illustrate that some earthquake ruptures repeatedly propagate along localized slip surfaces in the shallow crust and provide structural and material property constraints for in models of fault slip
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