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A document review to characterize Atomic International SNAP fuels shipped to INEL 1966--1973
This report provides the results of a document search and review study to obtain information on the spent fuels for the following six Nuclear Auxiliary Power (SNAP) reactor cores now stored at the Idaho National Engineering Laboratory (INEL): SNAP-2 Experimental Reactor, SNAP-2 Development Reactor, SNAP-10A Ground Test Reactor, SNAP-8 Experimental Reactor, SNAP-8 Development Reactor, and Shield Test Reactor. The report also covers documentation on SNAP fuel materials from four in-pile materials tests: NAA-82-1, NAA-115-2, NAA-117-1, and NAA-121. Pieces of these fuel materials are also stored at INEL as part of the SNAP fuel shipments
Conservative evaluation of the uncertainty in the LAGEOS-LAGEOS II Lense-Thirring test
We deal with the test of the general relativistic gravitomagnetic
Lense-Thirring effect currently ongoing in the Earth's gravitational field with
the combined nodes \Omega of the laser-ranged geodetic satellites LAGEOS and
LAGEOS II.
One of the most important source of systematic uncertainty on the orbits of
the LAGEOS satellites, with respect to the Lense-Thirring signature, is the
bias due to the even zonal harmonic coefficients J_L of the multipolar
expansion of the Earth's geopotential which account for the departures from
sphericity of the terrestrial gravitational potential induced by the
centrifugal effects of its diurnal rotation. The issue addressed here is: are
the so far published evaluations of such a systematic error reliable and
realistic? The answer is negative. Indeed, if the difference \Delta J_L among
the even zonals estimated in different global solutions (EIGEN-GRACE02S,
EIGEN-CG03C, GGM02S, GGM03S, ITG-Grace02, ITG-Grace03s, JEM01-RL03B, EGM2008,
AIUB-GRACE01S) is assumed for the uncertainties \delta J_L instead of using
their more or less calibrated covariance sigmas \sigma_{J_L}, it turns out that
the systematic error \delta\mu in the Lense-Thirring measurement is about 3 to
4 times larger than in the evaluations so far published based on the use of the
sigmas of one model at a time separately, amounting up to 37% for the pair
EIGEN-GRACE02S/ITG-Grace03s. The comparison among the other recent GRACE-based
models yields bias as large as about 25-30%. The major discrepancies still
occur for J_4, J_6 and J_8, which are just the zonals the combined
LAGEOS/LAGOES II nodes are most sensitive to.Comment: LaTex, 12 pages, 12 tables, no figures, 64 references. To appear in
Central European Journal of Physics (CEJP
Eosinophils Are Important for Protection, Immunoregulation and Pathology during Infection with Nematode Microfilariae
Eosinophil responses typify both allergic and parasitic helminth disease. In helminthic disease, the role of eosinophils can be both protective in immune responses and destructive in pathological responses. To investigate whether eosinophils are involved in both protection and pathology during filarial nematode infection, we explored the role of eosinophils and their granule proteins, eosinophil peroxidase (EPO) and major basic protein-1 (MBP-1), during infection with Brugia malayi microfilariae. Using eosinophil-deficient mice (PHIL), we further clarify the role of eosinophils in clearance of microfilariae during primary, but not challenge infection in vivo. Deletion of EPO or MBP-1 alone was insufficient to abrogate parasite clearance suggesting that either these molecules are redundant or eosinophils act indirectly in parasite clearance via augmentation of other protective responses. Absence of eosinophils increased mast cell recruitment, but not other cell types, into the broncho-alveolar lavage fluid during challenge infection. In addition absence of eosinophils or EPO alone, augmented parasite-induced IgE responses, as measured by ELISA, demonstrating that eosinophils are involved in regulation of IgE. Whole body plethysmography indicated that nematode-induced changes in airway physiology were reduced in challenge infection in the absence of eosinophils and also during primary infection in the absence of EPO alone. However lack of eosinophils or MBP-1 actually increased goblet cell mucus production. We did not find any major differences in cytokine responses in the absence of eosinophils, EPO or MBP-1. These results reveal that eosinophils actively participate in regulation of IgE and goblet cell mucus production via granule secretion during nematode-induced pathology and highlight their importance both as effector cells, as damage-inducing cells and as supervisory cells that shape both innate and adaptive immunity
Evaluation of Needle Exchange Programs
Needle exchange programs exist in every major population area in the United States and in many other countries. Some operate legally under emergency health decrees issued by local departments of health, with the stated intention of risk reduction through the removal of used injection equipment from use by injection drug users. It is theorized that this results in a reduced transmission of human immunodeficiency virus, hepatitis, and, possibly, other blood-borne diseases. Needle exchange programs also offer access to drug treatment programs for the participants. It is a difficult but necessary task to evaluate these programs. This article examines examples of evaluations attempted in the past and discusses the challenges of such evaluations. Experimental evaluations, economic program analysis, legal aspects, and risk–benefit assessment along with ethical aspects are considered. An outline of program evaluation is proposed. Needle exchange programs offer an opportunity to encourage risk reduction and to offer counseling and access to health care for individuals at high risk. It is essential that such programs demonstrate their effectiveness. Assumptions of efficacy are insufficient for health care in the twenty-first century
A mathematical and computational review of Hartree-Fock SCF methods in Quantum Chemistry
We present here a review of the fundamental topics of Hartree-Fock theory in
Quantum Chemistry. From the molecular Hamiltonian, using and discussing the
Born-Oppenheimer approximation, we arrive to the Hartree and Hartree-Fock
equations for the electronic problem. Special emphasis is placed in the most
relevant mathematical aspects of the theoretical derivation of the final
equations, as well as in the results regarding the existence and uniqueness of
their solutions. All Hartree-Fock versions with different spin restrictions are
systematically extracted from the general case, thus providing a unifying
framework. Then, the discretization of the one-electron orbitals space is
reviewed and the Roothaan-Hall formalism introduced. This leads to a exposition
of the basic underlying concepts related to the construction and selection of
Gaussian basis sets, focusing in algorithmic efficiency issues. Finally, we
close the review with a section in which the most relevant modern developments
(specially those related to the design of linear-scaling methods) are commented
and linked to the issues discussed. The whole work is intentionally
introductory and rather self-contained, so that it may be useful for non
experts that aim to use quantum chemical methods in interdisciplinary
applications. Moreover, much material that is found scattered in the literature
has been put together here to facilitate comprehension and to serve as a handy
reference.Comment: 64 pages, 3 figures, tMPH2e.cls style file, doublesp, mathbbol and
subeqn package
Proposed host galaxies of repeating fast radio burst sources detected by CHIME/FRB
We present a search for host galaxy associations for the third set of
repeating fast radio burst (FRB) sources discovered by the CHIME/FRB
Collaboration. Using the ~1 arcmin CHIME/FRB baseband localizations and
probabilistic methods. We identify potential host galaxies of two FRBs,
20200223B and 20190110C at redshifts of 0.06024(2) and 0.12244(6),
respectively. We also discuss the properties of a third marginal candidate host
galaxy association for FRB 20191106C with a host redshift of 0.10775(1). The
three putative host galaxies are all relatively massive, fall on the standard
mass-metallicity relationship for nearby galaxies, and show evidence of ongoing
star formation. They also all show signatures of being in a transitional
regime, falling in the "green valley" which is between the bulk of star-forming
and quiescent galaxies. The plausible host galaxies identified by our analysis
are consistent with the overall population of repeating and non-repeating FRB
hosts while increasing the fraction of massive and bright galaxies. Coupled
with these previous host associations, we identify a possible excess of FRB
repeaters whose host galaxies have M_u - M_r colors redder than the bulk of
star-forming galaxies. Additional precise localizations are required to confirm
this trend.Comment: 11 pages, submitted to AAS journal
The ves hypothesis and protein misfolding
Proteins function by changing conformation. These conformational changes, which involve the concerted motion of a large number of atoms are classical events but, in many cases, the triggers are quantum mechani-
cal events such as chemical reactions. Here the initial quantum states after
the chemical reaction are assumed to be vibrational excited states, something
that has been designated as the VES hypothesis. While the dynamics under
classical force fields fail to explain the relatively lower structural stability of
the proteins associated with misfolding diseases, the application of the VES hy-
pothesis to two cases can provide a new explanation for this phenomenon. This explanation relies on the transfer of vibrational energy from water molecules to proteins, a process whose viability is also examined
Localizing FRBs through VLBI with the Algonquin Radio Observatory 10 m Telescope
The Canadian Hydrogen Intensity Mapping Experiment (CHIME)/FRB experiment has detected thousands of fast radio bursts (FRBs) due to its sensitivity and wide field of view; however, its low angular resolution prevents it from localizing events to their host galaxies. Very long baseline interferometry (VLBI), triggered by FRB detections from CHIME/FRB will solve the challenge of localization for non-repeating events. Using a refurbished 10 m radio dish at the Algonquin Radio Observatory located in Ontario Canada, we developed a testbed for a VLBI experiment with a theoretical λ/D ≲ 30 mas. We provide an overview of the 10 m system and describe its refurbishment, the data acquisition, and a procedure for fringe fitting that simultaneously estimates the geometric delay used for localization and the dispersive delay from the ionosphere. Using single pulses from the Crab pulsar, we validate the system and localization procedure, and analyze the clock stability between sites, which is critical for coherently delay referencing an FRB event. We find a localization of ∼200 mas is possible with the performance of the current system (single-baseline). Furthermore, for sources with insufficient signal or restricted wideband to simultaneously measure both geometric and ionospheric delays, we show that the differential ionospheric contribution between the two sites must be measured to a precision of 1 × 10-8 pc cm-3 to provide a reasonable localization from a detection in the 400-800 MHz band. Finally we show detection of an FRB observed simultaneously in the CHIME and the Algonquin 10 m telescope, the first non-repeating FRB in this long baseline. This project serves as a testbed for the forthcoming CHIME/FRB Outriggers project
Comprehensive Bayesian analysis of FRB-like bursts from SGR 1935+2154 observed by CHIME/FRB
The bright millisecond-duration radio burst from the Galactic magnetar SGR
1935+2154 in 2020 April was a landmark event, demonstrating that at least some
fast radio burst (FRB) sources could be magnetars. The two-component burst was
temporally coincident with peaks observed within a contemporaneous short X-ray
burst envelope, marking the first instance where FRB-like bursts were observed
to coincide with X-ray counterparts. In this study, we detail five new radio
burst detections from SGR 1935+2154, observed by the CHIME/FRB instrument
between October 2020 and December 2022. We develop a fast and efficient
Bayesian inference pipeline that incorporates state-of-the-art Markov chain
Monte Carlo techniques and use it to model the intensity data of these bursts
under a flexible burst model. We revisit the 2020 April burst and corroborate
that both the radio sub-components lead the corresponding peaks in their
high-energy counterparts. For a burst observed in 2022 October, we find that
our estimated radio pulse arrival time is contemporaneous with a short X-ray
burst detected by GECAM and HEBS, and Konus-Wind and is consistent with the
arrival time of a radio burst detected by GBT. We present flux and fluence
estimates for all five bursts, employing an improved estimator for bursts
detected in the side-lobes. We also present upper limits on radio emission for
X-ray emission sources which were within CHIME/FRB's field-of-view at trigger
time. Finally, we present our exposure and sensitivity analysis and estimate
the Poisson rate for FRB-like events from SGR 1935+2154 to be
events/day above a fluence of
during the interval from 28 August 2018 to 1 December 2022, although we note
this was measured during a time of great X-ray activity from the source.Comment: 22 pages, 6 figures, 4 tables. To be submitted to Ap
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