A Gamma Ray Burst with a 220 Microsecond Rise Time and a Sharp Spectral Cutoff

The Gamma Ray Burst GRB920229 has four extreme and unprecedented properties; a rise in brightness with an e-folding time scale of $220 \pm 30 \mu s$, a fall in brightness with an e-folding time scale of $400 \pm 100 \mu s$, a large change in spectral shape over a time of $768 \mu s$, and a sharp spectral cutoff to high energies with $\Delta E/E = 18$. The rapid changes occur during a spike in the light curve which was seen 0.164 s after the start of the burst. The spectrum has a peak $\nu F_{\nu}$ at 200 keV with no significant flux above 239 keV, although the cutoff energy shifts to less than 100 keV during the decay of the spike. These numbers can be used to place severe limits on fireball models of bursts. The thickness of the energy production region must be smaller than $\sim 66 km$, ejected shells must have a dispersion of the Lorentz factor of less than roughly 1% along a particular radius, and the angular size of the radiation emission region is of order 1 arc-minute as viewed from the burst center. The physical mechanism that caused the sharp spectral cutoff has not been determined.Comment: 20 pages, 3 figures, Submitted to ApJ

Quotient groups of the fundamental groups of certain strata of the moduli space of quadratic differentials

In this paper, we study fundamental groups of strata of the moduli space of quadratic differentials. We use certain properties of the Abel-Jacobi map, combined with local surgeries on quadratic differentials, to construct quotient groups of the fundamental groups for a particular family of strata.Comment: 43 pages, 7 figures. Version 2: Minor typos fixed, Section 3 removed and may now be found in arXiv:0804.043

LG MS 038 Frances Peabody Papers Finding Aid

Description: Frannie Peabody was one of Maine\u27s leading AIDS activists. Best known in Maine and nationally for her exceptional leadership in the AIDS epidemic, she also gave significant service on historic preservation, child welfare, and gay rights issues. She was a founder of Portland’s The AIDS Project and of the Frannie Peabody Center (formerly Peabody House), as well as of Greater Portland Landmarks. The Papers contain Peabody\u27s personal papers, including her work with The AIDS Project and bereavement counseling. Date Range: 1981-1999 Size of Collection: 24.5 ft

Evaluation of the thermal performance of an innovative prefabricated natural plant fibre building system

Energy efficient new and retrofit building construction relies heavily on the use of thermal insulation. A focus on the environmental performance of current construction materials with regards to both embodied energy and energy in-use has resulted in a growing interest in the use of natural fibre insulation materials. The results of heat flow meter thermal conductivity tests on a range of straw samples of different densities are presented. The innovative use of straw in the development of a prefabricated straw-bale panel and the results of guarded hot-box testing are presented. In common with most building materials, there is a degree of uncertainty in the thermal conductivity due to the influences of temperature, moisture content and density; however, from evaluation of a range of the literature and experimental data, a value of 0.064 W/m·K is proposed as a representative design value for straw bales at the densities used in building construction. Computer simulation and experimental testing suggest that the overall heat transfer coefficient ( U-value) for the complete prefabricated panel is approximately 0.178 W/m2·K. This article also briefly discusses the use of this innovative unit in a highly instrumented test building constructed at the University of Bath. Practical application: Knowledge of the thermal properties of building materials is necessary for evaluation of energy performance of the building envelope and appraisal of retrofit fabric improvements. The presentation of robust data for the thermal properties of straw will be of interest to designers developing projects employing this natural fibre insulation material. </jats:p

Seventeenth century northern noble widows : a comparative study

This thesis is presented in part fulfilment of the Degree of Doctor of Philosophy at the University of Huddersfield. This thesis aims to explore the lives of seventeenth century noble widows in the north of England. The issues investigated include the demographics of widowhood, economics of widowhood, charitable activities, noble widows and the law, social networks surrounding widows and widows' political interests. Each of these subjects forms a chapter, where widows' contribution to each sphere through the seventeenth century is explored and assessed. The work also covers wider issues which affected women prior to and during marriage as they were also relevant to widowhood. Therefore it has been necessary to widen the scope of research from analyzing women's lives after the deaths of their husbands. Similarly, the geographical scope of the research, whilst basically entrenched in the north of England, extends in response to the variety of widows' experiences. The research has required examination of primary source material generated by widows such as letters, diaries, estate records and account books from institutions such as the British Library and private libraries such as that at Chatsworth. The second aim of this thesis is to examine more recent attitudes towards seventeenth century noble widows, encompassing the writings of nineteenth century historians and contemporary authors. The subject of this study is an under researched area and the thesis highlights the importance of the only part of a noblewoman's life that was lived as an independent individual. By scrutinising the secondary source material, challenging and criticizing general arguments proposed by other writers, debate upon the subject should be increased and new ideas expressed. Despite the social, legal, economic and political changes which took place throughout the seventeenth century, noble widows remained influential figures within the contexts of family, household and society as they exploited legal loopholes or accepted conventions in order to further their individual aims. This study advances the understanding of women's history by focussing on a neglected aspect of the subject, provides a new viewpoint for regional history and stimulates ideas for further academic debate.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Gamma-ray bursts have millisecond variability

We have performed searches for isolated flares and for steady flickering in the initial ∼ 1 s of gamma-ray burst light curves on the microsecond to millisecond timescales. Two bursts among our sample of 20 revealed four isolated flares with timescales from 256 to 2048 μs. A wavelet analysis for our sample showed low-level flickering for all bursts on timescales from 256 μs to 33 ms, with the majority of bursts containing rise times faster than 4 ms and 30% having rise times faster than 1 ms. These results show that millisecond variability is common in classical bursts and not some exceptional activity by a possibly separate class of bursts. These fast rise times can be used to place the following severe limits on burst models. (1) The characteristic thickness of the energy generation region must be less than 1200 km along the line of sight. (2) The angular size of the gamma-ray emission region as subtended from the central source must be less than 42″. (3) The expanding ejecta must have a range of Lorentz factors along a radius line with a dispersion of less than roughly 2%. (4) Within the external shock scenario, the characteristic dimension of the impacted cloud must be smaller than 16 AU on average. (5) Within the collimated jet scenario, the collimation angle must be smaller than 42″

What does economic evaluation mean in the context of children at the end of their life?

The ‘conventional framework’ of economic evaluation, the comparative public sector healthcare costs and quality adjusted life year (QALY) of two or more interventions, has become synonymous with commissioning decisions in many countries. However, while useful as a framework in guiding value-based decisions, it has limited relevance in areas such as end of life care in children and young people, where the costs fall across multiple stakeholders and QALY gains are not the primary outcome. This paper makes the case that the restricted relevance of the ‘conventional framework’ has contributed to the inconsistent and varied provision of care in this setting, and to the knock-on detrimental impact on children nearing the end of their lives as well as their families. We explore the challenges faced by those seeking to conduct economic evaluations in this setting alongside some potential solutions. We conclude that there is no magic bullet approach that will amalgamate the ‘conventional framework’ with the requirements of a meaningful economic evaluation in this setting. However, this does not imply a lack of need for the summation of the costs and outcomes of care able to inform decision makers, and that methods such as impact inventory analysis may facilitate increased flexibility in economic evaluations

The Ursinus Weekly, October 27, 1952

Students and old timers enjoy varied activities: Ellie Unger crowned queen of Varsity Club dance; 724 wins golden trophy for best dorm decorations • 21 degrees conferred at Founders Day exercises: Helfferich, Lauer receive Doctor of Laws degrees; Vice President gives speech stressing college history • Ursinus, U. P. form program for engineers • Fraternities gave parties; Rushing starts this week • College fills blood quota • German Club holds meeting; Plans for year\u27s activities • Senior carnival, dance to be this weekend • Dr. Witmer receives Doctor of Pedagogy degree from F&M • Business Administration Club to hear advertising rep. • Y work day, chat to be Sat., Wed. • IRC hears librarian speak on Philippines • Miller, Pancoast to debate • Girls begin rushing today • WSGA changes frosh drug rules • Frosh women in booster group set up 15, 20 cent poster rates • Movie to be shown in S-12, Fri. • Lantern holds meeting • French Club to meet • Editorials: Let\u27s do something • Typical American family • Letters to the editor • Square dance to be Nov. 8 • Chi Alpha alters constitution • Liberals have free speech • Students attend Eisenhower press conference in Phila. • Pre-meds to hear Wagner • Married • Chess Club loses • And if it isn\u27t gov\u27nuh Jones back from Meddie England • Knull and Burger mates throughout ship\u27s tour on sea • New look, new hours, new food bring new life to the Supply • Albright beats third team • Lafayette booters hand Bears first defeat, 5-1 • Bears win 6-0 on Maliken\u27s last second TD: Grizzly Bears victorious in second straight game; Goal line stand saves Old Timers Day gridiron thriller • Girls drop hockey game to Beaver, 4-3 • Bakermen win over grads • West Chester is defeated, 7-2 • Canterbury Club to meethttps://digitalcommons.ursinus.edu/weekly/1503/thumbnail.jp