16 research outputs found
The Magellanic Stream, High-Velocity Clouds and the Sculptor Group
The Magellanic Stream is a 100\deg x 10\deg filament of gas which lies within the Galactic halo and contains ~ 2 x 10^8 \Msun of neutral hydrogen. We present data from the HI Parkes All Sky Survey (HIPASS) in the first complete survey of the entire Magellanic Stream and its surroundings. We also present a summary of the reprocessing techniques used to recover large-scale structure in the Stream. The Stream properties revealed include: bifurcation along the main Stream filament; dense, isolated clouds which follow the entire length of the Stream; head-tail structures; and a complex filamentary web at the head where gas is being freshly stripped away from the Small Magellanic Cloud and the Bridge. Debris which appears to be of Magellanic origin extends out to 20\deg from the main Stream filaments. The large number of elongated Stream clouds suggests the presence of shearing motions within the Stream, arising from tidal forces or interaction with the tenuous Galactic halo. Clouds along the sightline to the less distant half of the Sculptor Group, show anomalous properties. We argue that these clouds represent halo material, and are not distant Sculptor Group clouds. This result has significant implications for the hypothesis that there might exist distant, massive HVCs within the Local Group. (abridged
Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae
We systematically surveyed period variations of superhumps in SU UMa-type
dwarf novae based on newly obtained data and past publications. In many
systems, the evolution of superhump period are found to be composed of three
distinct stages: early evolutionary stage with a longer superhump period,
middle stage with systematically varying periods, final stage with a shorter,
stable superhump period. During the middle stage, many systems with superhump
periods less than 0.08 d show positive period derivatives. Contrary to the
earlier claim, we found no clear evidence for variation of period derivatives
between superoutburst of the same object. We present an interpretation that the
lengthening of the superhump period is a result of outward propagation of the
eccentricity wave and is limited by the radius near the tidal truncation. We
interpret that late stage superhumps are rejuvenized excitation of 3:1
resonance when the superhumps in the outer disk is effectively quenched. Many
of WZ Sge-type dwarf novae showed long-enduring superhumps during the
post-superoutburst stage having periods longer than those during the main
superoutburst. The period derivatives in WZ Sge-type dwarf novae are found to
be strongly correlated with the fractional superhump excess, or consequently,
mass ratio. WZ Sge-type dwarf novae with a long-lasting rebrightening or with
multiple rebrightenings tend to have smaller period derivatives and are
excellent candidate for the systems around or after the period minimum of
evolution of cataclysmic variables (abridged).Comment: 239 pages, 225 figures, PASJ accepte
Pequena história da ideia de fetiche religioso: de sua emergência a meados do século XX
A ideia de fetiche religioso, fruto do encontro afro-europeu na costa da Guiné há cerca de quatro séculos percorreu um longo caminho, desde seu uso por viajantes e comerciantes, passando pela sua apropriação pela filosofia iluminista, sua radicalização e popularização no positivismo e no evolucionismo, até ser criticada, entrar em declínio e ser considerada estéril pela antropologia modernista. O objetivo deste artigo é lançar uma luz sobre tal trajetória, não de maneira desinteressada, mas dentro de um contexto contemporâneo de reavaliação da ideia de fetiche enquanto ferramenta heurística, o que sugere uma paralela reavaliação da história do conceito
Insights into collaboration at the project level: Complexity, social interaction and procurement mechanisms
Drawing upon relevant concepts in organizational social theory (becoming ontology and processual view of complexity), and adopting an interpretative approach to studying organizational phenomena, this paper aims to make a contribution to the understanding of social processes in multi-organizational settings defined as 'construction projects'. The study takes a critical view on the claimed advantages of non-conventional, innovative project procurement strategies as integration-enhancing mechanisms at the project level. Taking a swimming pool construction project governed by an innovative procurement procedure known as 'two-stage tender' as a case in point, the paper evaluates the extent to which better project team integration has been achieved in this context. Two major concerns emerged from the case study analysis: (1) two-stage tendering is an incomplete solution to tensions, adversarial culture and a lack of genuine cooperation over time; and (2) there is a need for facilitating mechanisms of a different nature to support and sustain collective situated learning and shared understanding of longer-term benefits of collaborative work. Based on the theoretical considerations and the interpretation of the empirical accounts, the paper proposes and refines a conceptual framework for understanding the complexity of construction projects as social settings. In the light of this framework, alternative concepts and skills for enhanced collaborative interaction among participating parties in this kind of social setting are suggested. © 2005 Taylor & Francis
Practical Asymmetric Synthesis of an Edivoxetine·HCl Intermediate via an Efficient Diazotization Process
A convergent
synthesis of (<i>S</i>)-(4-benzylmorpholin-2-yl)(morpholino)methanone
methanesulfonate (<b>1</b>), a key regulatory starting material
for edivoxetine·HCl, was developed at Eli Lilly & Company.
This novel synthesis utilizes d-serine as the source of chirality,
which is preserved throughout the synthesis. Key features include
the development of a scalable diazotization process to produce (<i>S</i>)-epoxy acid <b>7</b>, which was optimized to improve
the process safety profile. The final (<i>S</i>)-morpholino
acid intermediate <b>11</b> was converted to the title compound
using T3P with >99.9% purity in 75% yield. Life cycle analysis
of
the new route revealed a 69% reduction in global warming potential
(GWP) for solvent usage relative to the prior route of manufacture