Mechanical testing of advanced coating system, volume 1

The Electron Beam Physical Vapor Deposition (EBPVD) coating material has a highly columnar microstructure, and as a result it was expected to have very low tensile strength. To be able to fabricate the required compression and tensile specimens, a substrate was required to provide structural integrity for the specimens. Substrate and coating dimensions were adjusted to provide sufficient sensitivity to resolve the projected loads carried by the EBPVD coating. The use of two distinctively different strain transducer systems, for tension and compression loadings, mandated two vastly different specimen geometries. Compression specimen and tensile specimen geometries are given. Both compression and tensile test setups are described. Data reduction mathematical models are given and discussed in detail as is the interpretation of the results. Creep test data is also given and discussed

Manual for an International Trade Data Base on the IBM Computer of the Hungarian Academy of Sciences

This manual has been prepared to allow IIASA economists to access an international trade data base stored on the IBM computer at the Hungarian Academy of Sciences in Budapest. It describes the contents of the data base and the capabilities of the data-handling program, and explains how the data base may be accessed from IIASA via the Gateway system. It is hoped that the information made available in this way will be useful in the work on economic structural change currently in progress at IIASA

C2_2H observations toward the Orion Bar

C$_2$H is one of the first radicals to be detected in the interstellar medium. Its higher rotational transitions have recently become available with the Herschel Space Observatory. We aim to constrain the physical parameters of the C$_2$H emitting gas toward the Orion Bar. We analyse the C$_2$H line intensities measured toward the Orion Bar CO$^+$ Peak and Herschel/HIFI maps of C$_2$H, CH, and HCO$^+$, and a NANTEN map of [CI]. We interpret the observed C$_2$H emission using radiative transfer and PDR models. Five rotational transitions of C$_2$H have been detected in the HIFI frequency range toward the CO$^+$ peak. A single component rotational diagram gives a rotation temperature of ~64 K and a beam-averaged C$_2$H column density of 4$\times$10$^{13}$ cm$^{-2}$. The measured transitions cannot be explained by any single parameter model. According to a non-LTE model, most of the C$_2$H column density produces the lower-$N$ C$_2$H transitions and traces a warm ($T_{\rm{kin}}$ ~ 100-150 K) and dense ($n$(H$_2$)~10$^5$-10$^6$ cm$^{-3}$) gas. A small fraction of the C$_2$H column density is required to reproduce the intensity of the highest-$N$ transitions ($N$=9-8 and N=10-9) originating from a high density ($n$(H$_2$)~5$\times$10$^6$ cm$^{-3}$) hot ($T_{\rm{kin}}$ ~ 400 K) gas. The total beam-averaged C$_2$H column density in the model is 10$^{14}$ cm$^{-2}$. Both the non-LTE radiative transfer model and a simple PDR model representing the Orion Bar with a plane-parallel slab of gas and dust suggest, that C$_2$H cannot be described by a single pressure component, unlike the reactive ion CH$^+$, which was previously analysed toward the Orion Bar CO$^+$ peak. The physical parameters traced by the higher rotational transitions ($N$=6-5,...,10-9) of C$_2$H may be consistent with the edges of dense clumps exposed to UV radiation near the ionization front of the Orion Bar.Comment: Proposed for acceptance in A&A, abstract abridge

Physical and chemical differentiation of the luminous star-forming region W49A - Results from the JCMT Spectral Legacy Survey

The massive and luminous star-forming region W49A is a well known Galactic candidate to probe the physical conditions and chemistry similar to those expected in external starburst galaxies. We aim to probe the physical and chemical structure of W49A on a spatial scale of ~0.8 pc based on the JCMT Spectral Legacy Survey, which covers the frequency range between 330 and 373 GHz. The wide 2x2 arcminutes field and the high spectral resolution of the HARP instrument on JCMT provides information on the spatial structure and kinematics of the cloud. For species where multiple transitions are available, we estimate excitation temperatures and column densities. We detected 255 transitions corresponding to 60 species in the 330-373 GHz range at the center position of W49A. Excitation conditions can be probed for 16 molecules. The chemical composition suggests the importance of shock-, PDR-, and hot core chemistry. Many molecular lines show a significant spatial extent across the maps including high density tracers (e.g. HCN, HNC, CS, HCO+) and tracers of UV-irradiation (e.g. CN and C2H). Large variations are seen between the sub-regions with mostly blue-shifted emission toward the Eastern tail, mostly red-shifted emission toward the Northern clump, and emission peaking around the expected source velocity toward the South-west clump. A comparison of column density ratios of characteristic species observed toward W49A to Galactic PDRs suggests that while the chemistry toward the W49A center is driven by a combination of UV-irradiation and shocks, UV-irradiation dominates for the Northern Clump, Eastern tail, and South-west clump regions. A comparison to a starburst galaxy and an AGN suggests similar C2H, CN, and H2CO abundances (with respect to the dense gas tracer 34CS) between the ~0.8 pc scale probed for W49A and the >1 kpc regions in external galaxies with global star-formation.Comment: Proposed for acceptance in A&A, abstract abridge

Report from ionospheric science

The general strategy to advance knowledge of the ionospheric component of the solar terrestrial system should consist of a three pronged attack on the problem. Ionospheric models should be refined by utilization of existing and new data bases. The data generated in the future should emphasize spatial and temporal gradients and their relation to other events in the solar terrestrial system. In parallel with the improvement in modeling, it will be necessary to initiate a program of advanced instrument development. In particular, emphasis should be placed on the area of improved imaging techniques. The third general activity to be supported should be active experiments related to a better understanding of the basic physics of interactions occurring in the ionospheric environment. These strategies are briefly discussed

Heterogeneity of the Tumor Vasculature: The Need for New Tumor Blood Vessel Type-Specific Targets

Therapies directed against VEGF-A and its receptors are effective in treating many mouse tumors but have been less so in treating human cancer patients. To elucidate the reasons that might be responsible for this difference in response, we investigated the nature of the blood vessels that appear in human and mouse cancers and the tumor “surrogate” blood vessels that develop in immunodeficient mice in response to an adenovirus expressing $VEGF-A^{164}$. Both tumor and tumor surrogate blood vessels are heterogeneous and form by two distinct processes, angiogenesis and arterio-venogenesis. The first new angiogenic blood vessels to form are mother vessels (MV); MV arise from preexisting venules and capillaries and evolve over time into glomeruloid microvascular proliferations (GMP) and subsequently into capillaries and vascular malformations (VM). Arterio-venogenesis results from the remodeling and enlargement of preexisting arteries and veins, leading to the formation of feeder arteries (FA) and draining veins (DV) that supply and drain angiogenic vessels. Of these different blood vessel types, only the two that form first, MV and GMP, were highly responsive to anti-VEGF therapy, whereas “late”-formed capillaries, VM, FA and DV were relatively unresponsive. This finding may explain, at least in part, the relatively poor response of human cancers to anti-VEGF/VEGFR therapies, because human cancers, present for months or years prior to discovery, are expected to contain a large proportion of late-formed blood vessels. The future of anti-vascular cancer therapy may depend on finding new targets on “late” vessels, apart from those associated with the VEGF/VEGFR axis

Three-jet cross sections in hadron-hadron collisions at next-to-leading order

We present a new QCD event generator for hadron collider which can calculate one-, two- and three-jet cross sections at next-to-leading order accuracy. In this letter we study the transverse energy spectrum of three-jet hadronic events using the kT algorithm. We show that the next-to-leading order correction significantly reduces the renormalization and factorization scale dependence of the three-jet cross section.Comment: 4 pages, 4 figures, REVTEX

Dynamics explorer interdisciplinary scientist investigations

This document is a final report on research activities and accomplishments that occurred during the funding period of 10-1-90 through 1-30-94. The focus of our interdisciplinary investigation during the Dynamics Explorer Mission was on the complex coupling processes that tap the magnetic-storm energy, stored in the ring current particle reservoir, and transport this energy into the subauroral, midlatitude and even equatorial ionospheric regions. The transport of energy through the inner magnetosphere and into the underlying ionospheric regions is a critical element in our understanding of the impact of solar and magnetic disturbances on upper atmospheric and ionospheric regions equatorward of the auroral zone

Report from upper atmospheric science

Most of the understanding of the thermosphere resulted from the analysis of data accrued through the Atmosphere Explorer satellites, the Dynamics Explorer 2 satellite, and observations from rockets, balloons, and ground based instruments. However, new questions were posed by the data that have not yet been answered. The mesosphere and lower thermosphere have been less thoroughly studied because of the difficulty of accessibility on a global scale, and many rather fundamental characteristics of these regions are not well understood. A wide variety of measurement platforms can be used to implement various parts of a measurement strategy, but the major thrusts of the International Solar Terrestrial Physics Program would require Explorer-class missions. A remote sensing mission to explore the mesosphere and lower thermosphere and one and two Explorer-type spacecraft to enable a mission into the thermosphere itself would provide the essential components of a productive program of exploration of this important region of the upper atomsphere. Theoretical mission options are explored