5,553 research outputs found

    Problem-Based Cooperative Learning

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    Dickens and the unreal city : the metropolitan symbolism of the mystery story

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    London is not only a backdrop in the novels of Charles Dickens. Its workings both conceal truth of various sorts from characters and push it into the open. This thesis claims that it is the primary symbolic means by which Dickens dramatizes the conflict between concealment and revelation which provides the driving force of his fiction. The first chapter discusses how the city extrapolates the gothic motif of the haunted castle - a built environment which attempts to cut off connections with the rest of the world, leading to a state of atrophy and death. The second particularly explores urban squalor as evidence that human relationships have been obscured and that death is the result. Chapter three explores the kind of concealments and deaths effected by London and explains that the regenerative revelation required as an antidote to them is both social and religious in character. Dickens conceptualizes it as a participation in a familial system of love relationships originating in God's love for his children. The fourth and fifth chapters deal with two parts of London's organisation that bring knowledge inexorably to light, the detective police force and the railway network. They are part of a city that hides truth and brings it to light according to a carefully laid plan. Chapters six and seven consider two sub-symbols, the Thames and the crowd, that reflect the city's dual role in bringing both death and regeneration, both concealment and discovery. Characters' immersion in these brings about a death to their old identity and often a re-emergence into a new identity, based on the scheme of interconnections, that is both a revelation and an induction into new life. The mysteries worked out by Dickens's symbolic London are therefore an imaginative engagement with Christianity as a mystery religion, promising revelatory regeneration through surrender to death in the modern world

    A survey of diffuse interstellar bands in the Andromeda galaxy: optical spectroscopy of M31 OB stars

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    We present the largest sample to-date of intermediate-resolution blue-to-red optical spectra of B-type supergiants in M31 and undertake the first survey of diffuse interstellar bands (DIBs) in this galaxy. Spectral classifications, radial velocities and interstellar reddenings are presented for 34 stars in three regions of M31. Radial velocities and equivalent widths are given for the 5780 and 6283 DIBs towards 11 stars. Equivalent widths are also presented for the following DIBs detected in three sightlines in M31: 4428, 5705, 5780, 5797, 6203, 6269, 6283, 6379, 6613, 6660, and 6993. All of these M31 DIB carriers reside in clouds at radial velocities matching those of interstellar Na I and/or H I. The relationships between DIB equivalent widths and reddening (E(B-V)) are consistent with those observed in the local ISM of the Milky Way. Many of the observed sightlines show DIB strengths (per unit reddening) which lie at the upper end of the range of Galactic values. DIB strengths per unit reddening are found (with 68% confidence), to correlate with the interstellar UV radiation field strength. The strongest DIBs are observed where the interstellar UV flux is lowest. The mean Spitzer 8/24 micron emission ratio in our three fields is slightly lower than that measured in the Milky Way, but we identify no correlation between this ratio and the DIB strengths in M31. Interstellar oxygen abundances derived from the spectra of three M31 H II regions in one of the fields indicate that the average metallicity of the ISM in that region is 12 + log[O/H] = 8.54 +- 0.18, which is approximately equal to the value in the solar neighbourhood

    Finding a state in a haystack

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    We consider the problem to single out a particular state among 2n2^n orthogonal pure states. As it turns out, in general the optimal strategy is not to measure the particles separately, but to consider joint properties of the nn-particle system. The required number of propositions is nn. There exist 2n!2^n! equivalent operational procedures to do so. We enumerate some configurations for three particles, in particular the Greenberger-Horne-Zeilinger (GHZ)- and W-states, which are specific cases of a unitary transformation For the GHZ-case, an explicit physical meaning of the projection operators is discussed.Comment: 11 page

    Students’ Successes and Challenges Applying Data Analysis and Measurement Skills in a Fifth-Grade Integrated STEM Unit

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    An understanding of statistics and skills in data analysis are becoming more and more essential, yet research consistently shows that students struggle with these concepts at all levels. This case study documents some of the struggles four groups of fifth-grade students encounter as they collect, organize, and interpret data and then ultimately attempt to draw conclusions or make decisions based on these data. The activities in which the students engaged were part of an integrated science, technology, engineering, and mathematics (STEM) unit that had students collecting and analyzing data both in the context of learning science concepts and in the context of evaluating prototypes for an engineering design challenge. Students were observed to struggle in a variety of ways, specifically having difficulty (1) properly using certain measurement devices, (2) coordinating quantitative data with the phenomenon being measured, and (3) properly interpreting the significance of variation, uncertainty, and error in the data. Implications for teaching and curriculum design are addressed

    Small magellanic cloud-type interstellar dust in the milky way

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    It is well known that the sight line toward HD 204827 in the cluster Trumpler 37 shows a UV extinction curve that does not follow the average Galactic extinction relation. However, when a dust component, fore-ground to the cluster, is removed, the residual extinction curve is identical to that found in the SMC within the uncertainties. The curve is very steep and has little or no 2175 A bump. The position of HD 204827 in the sky is projected onto the edge of the Cepheus IRAS bubble. In addition, HD 204827 has an IRAS bow shock, indicating that it may be embedded in dust swept up by the supernova that created the IRAS bubble. Shocks due to the supernova may have led to substantial processing of this dust. The HD 204827 cloud is dense and rich in carbon molecules. The 3.4 ÎĽm feature indicating a C-H grain mantle is present in the dust toward HD 204827. The environment of the HD 204827 cloud dust may be similar to the dust associated with HD 62542, which lies on the edge of a stellar wind bubble and is also dense and rich in molecules. This sight line may be a Rosetta Stone if its environment can be related to those in the SMC having similar dust
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