1,180 research outputs found
Global energetic neutral atom (ENA) measurements and their association with the Dst index
We present a new global magnetospheric index that measures the intensity of the Earth\u27s ring current through energetic neutral atoms (ENAs). We have named it the Global Energetic Neutral Index (GENI), and it is derived from ENA measurements obtained by the Imaging Proton Spectrometer (IPS), part of the Comprehensive Energetic Particle and Pitch Angle Distribution (CEPPAD) experiment on the POLAR satellite. GENI provides a simple orbit-independent global sum of ENAs measured with IPS. Actual ENA measurements for the same magnetospheric state look different when seen from different points in the POLAR orbit. In addition, the instrument is sensitive to weak ion populations in the polar cap, as well as cosmic rays. We have devised a method for removing the effects of cosmic rays and weak ion fluxes, in order to produce an image of “pure” ENA counts. We then devised a method of normalizing the ENA measurements to remove the orbital bias effect. The normalized data were then used to produce the GENI. We show, both experimentally and theoretically the approximate proportionality between the GENI and the Dst index. In addition we discuss possible implications of this relation. Owing to the high sensitivity of IPS to ENAs, we can use these data to explore the ENA/Dst relationship not only during all phases of moderate geomagnetic storms, but also during quiescent ring current periods
Investigation of DC-8 nacelle modifications to reduce fan-compressor noise in airport communities. Part 2 - Design studies and duct-lining investigations, May 1967 - October 1969
Modifications to reduce fan-compressor noise level of DC-8 aircraft - Part
TeV Gamma Ray Emission from Southern Sky Objects and CANGAROO Project
We report recent results of the CANGAROO Collaboration on very high energy
gamma ray emission from pulsars, their nebulae, SNR and AGN in the southern
sky. Observations are made in South Australia using the imaging technique of
detecting atmospheric Cerenkov light from gamma rays higher than about 1 TeV.
The detected gamma rays are most likely produced by the inverse Compton process
by electrons which also radiate synchrotron X-rays. Together with information
from longer wavelengths, our results can be used to infer the strength of
magnetic field in the emission region of gamma rays as well as the energy of
the progenitor electrons. A description of the CANGAROO project is also given,
as well as details of the new telescope of 7 m diameter which is scheduled to
be in operation within two years.Comment: 5 pages, 1 figure, LaTeX 2.09 with aipproc.sty & epsfig.sty, to
appear in proceedings of the 4th Compton Symposium, Williamsburg, 199
Detection of Gamma Rays of Up to 50 TeV From the Crab Nebula
Gamma rays with energies greater than 7 TeV from the Crab pulsar/nebula have
been observed at large zenith angles, using the Imaging Atmospheric Technique
from Woomera, South Australia. CANGAROO data taken in 1992, 1993 and 1995
indicate that the energy spectrum extends up to at least 50 TeV, without a
change of the index of the power law spectrum. The observed differential
spectrum is \noindent between 7 TeV and 50 TeV. There is no apparent
cut-off. The spectrum for photon energies above 10 TeV allows the maximum
particle acceleration energy to be inferred, and implies that this unpulsed
emission does not originate near the light cylinder of the pulsar, but in the
nebula where the magnetic field is not strong enough to allow pair creation
from the TeV photons. The hard gamma-ray energy spectrum above 10 TeV also
provides information about the varying role of seed photons for the inverse
Compton process at these high energies, as well as a possible contribution of
-gamma rays from proton collisions.Comment: 19 pages, 4 figures, LaTeX2.09 with AASTeX 4.0 maros, to appear in
Astrophys. J. Let
Distillation of Liquid Xenon to Remove Krypton
A high performance distillation system to remove krypton from xenon was
constructed, and a purity level of Kr/Xe = was
achieved. This development is crucial in facilitating high sensitivity low
background experiments such as the search for dark matter in the universe.Comment: 15 pages, 11 figure
Phase I study of TP300 in patients with advanced solid tumors with pharmacokinetic, pharmacogenetic and pharmacodynamic analyses
Background: A Phase I dose escalation first in man study assessed maximum tolerated dose (MTD), dose-limiting toxicity (DLT) and recommended Phase II dose of TP300, a water soluble prodrug of the Topo-1 inhibitor TP3076, and active metabolite, TP3011.
<p/>Methods: Eligible patients with refractory advanced solid tumors, adequate performance status, haematologic, renal, and hepatic function. TP300 was given as a 1-hour i.v. infusion 3-weekly and pharmacokinetic (PK) profiles of TP300, TP3076 and TP3011 were analysed. Polymorphisms in CYP2D6, AOX1 and UGT1A1 were studied and DNA strand-breaks measured in peripheral blood mononuclear cells (PBMCs).
<p/>Results: 32 patients received TP300 at 1, 2, 4, 6, 8, 10, 12 mg/m2. MTD was 10 mg/m2; DLTs at 12 (2/4 patients) and 10 mg/m2 (3/12) included thrombocytopenia and febrile neutropenia; diarrhea was uncommon. Six patients (five had received irinotecan), had stable disease for 1.5-5 months. TP3076 showed dose proportionality in AUC and Cmax from 1--10 mg/m2. Genetic polymorphisms had no apparent influence on exposure. DNA strand-breaks were detected after TP300 infusion.
<p/>Conclusions: TP300 had predictable hematologic toxicity, and diarrhea was uncommon. AUC at MTD is substantially greater than for SN38. TP3076 and TP3011 are equi-potent with SN38, suggesting a PK advantage
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