5,922 research outputs found
Hans Bethe: The Nuclear Many Body Problem
We discuss the work of Hans Bethe and others in formulating a theoretical
foundation for the nuclear shell model. Written for a general audience, this
article describes the evolution from Brueckner's reaction matrix theory to the
Moszkowski-Scott separation method and ultimately to the Reference Spectrum
method of Bethe, Brandow, and Petschek. We also discuss connections with the
recently developed low momentum nucleon-nucleon interactions.Comment: 25 pages, 15 figures, In "Hans Bethe and His Physics" (World
Scientific, Singapore, 2006
Weighing up risk factors for pneumonia: the role of mental illness and benzodiazepine use.
Oral Sources and PRC History: Best and Worst Practices
After grappling with such methodological dilemmas of finding interviewees, building trust, and recording or transcribing conversations, scholars of PRC history face different challenges as they shift from field research to the writing stage: how to present oral testimonies on the written page, and how to integrate oral history with textual sources. Drawing on the author\u27s experience conducting more than one hundred interviews about the rural-urban divide, the aftermath of accidents, and the Tiananmen Square protests of 1989, this paper offers practical advice about:- When to name names and when to protect anonymity;- How to track down interview subjects mentioned in written sources;- How to balance the scholarly impulse to frame and condense oral testimonies with the benefits of letting interviewees speak for themselves;- Which types of written sources most fruitfully complement oral histories. In addition to discussing the author\u27s own discoveries and mistakes, the paper also highlights the contributions and shortcomings of other recent works that draw on oral testimonies
Statistical Image Reconstruction for High-Throughput Thermal Neutron Computed Tomography
Neutron Computed Tomography (CT) is an increasingly utilised non-destructive
analysis tool in material science, palaeontology, and cultural heritage. With
the development of new neutron imaging facilities (such as DINGO, ANSTO,
Australia) new opportunities arise to maximise their performance through the
implementation of statistically driven image reconstruction methods which have
yet to see wide scale application in neutron transmission tomography. This work
outlines the implementation of a convex algorithm statistical image
reconstruction framework applicable to the geometry of most neutron tomography
instruments with the aim of obtaining similar imaging quality to conventional
ramp filtered back-projection via the inverse Radon transform, but using a
lower number of measured projections to increase object throughput. Through
comparison of the output of these two frameworks using a tomographic scan of a
known 3 material cylindrical phantom obtain with the DINGO neutron radiography
instrument (ANSTO, Australia), this work illustrates the advantages of
statistical image reconstruction techniques over conventional filter
back-projection. It was found that the statistical image reconstruction
framework was capable of obtaining image estimates of similar quality with
respect to filtered back-projection using only 12.5% the number of projections,
potentially increasing object throughput at neutron imaging facilities such as
DINGO eight-fold
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Proposition 6 and Local Debt Levels in Texas
The Kay Bailey Hutchison Center for Energy, Law, and Busines
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Water Protectionism Hurts the Economies of Fast-Growing Regions
The Kay Bailey Hutchison Center for Energy, Law, and Busines
An evaluation of the educational program of the Springfield, Vermont, High School.
Thesis (Ed.D.)--Boston University
Vita.
Includes bibliographical references (leaves 435-440)
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