3,450 research outputs found

    Collections for people: museums' stored collections as a public resource

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    Collections in UK museums grew enormously in the latter half of the 20th century yet museum collections, mostly maintained at public expense, are perceived as an underused resource. The Museums Association’s 2005 report, Collections for the Future1, together with press comments and books such as Treasures on Earth (2002)2 and Fragments of the World (2005)3, brought this issue into sharp focus. Collections for People set out to understand the scale of museum stored collections, and the main parameters of their access and use: • What is the size and nature of collections as a resource? How are they distributed, geographically and among different types of museum? • How much are different types of collection used by people other than museum staff? What sort of people use collections? What do they use them for: research, teaching and learning, creative activities, visits for enjoyment such as store tours? • How do users perceive this service? Do museums actively market collections access? Do they publicise what is in their collections? • How do museums facilitate collections use? What are the factors associated with greater use of collections? What do museums see as the barriers to more use

    Comparison of submillimeter and ultraviolet observations of neutral carbon toward Zeta Ophiuchi

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    We have observed the ^3P_1 → ^3P_0 ground state transition of C_I emission toward ζ Oph. We compare this observation with predictions made from Copernicus ultraviolet absorption measurements of the population of the ^3P_1 level and with millimeter wave observations of CO

    Development of carbon dioxide laser doppler instrumentation detection of clear air turbulence

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    The analytical, experimental, and developmental aspects of an airborne, pulsed, carbon dioxide laser-optical radar system are described. The laser detects clear air turbulence and performs Doppler measurements of this air-motion phenomenon. Conclusions and recommendations arising from the development of the laser system are presented

    The abundances of atomic carbon and carbon monoxide compared with visual extinction in the Ophiuchus molecular cloud complex

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    We have observed emission from the 492 GHz lines of C I toward six positions in the Ophiuchus molecular cloud complex for which accurate visual extinctions are available. We find that the column density of C I increases with A_v to greater than 2 x 10^(17) cm^(-2) at 100 mag, the column-averaged fractional abundance reaches a peak of about 2.2 x 10^(-5) for A_v in the range 4-11 mag and the column-averaged abundance ratio of C I to CO decreases with A_v from about 1 at 2 mag to greater than ~0.03 at 100 mag. These results imply that, while C I is not the primary reservoir of gaseous carbon even at cloud edges, its fractional abundance remains high for at least 10 mag into the cloud and may be significant at even greater depths

    Chlorine in dense interstellar clouds - The abundance of HCl in OMC-1

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    We report the first detection of a chlorine-bearing molecular species in the interstellar medium via emission from the J = 1 → 0 transition of HCl at 625.9 GHz toward OMC-1. The relative strengths, widths, and velocities of the resolved hyperfine components are consistent with moderate optical depth emission originating from dense, quiescent molecular cloud material (V_(LSR) = 9 km s^(-1)). The overall emission strength implies a fractional abundance of f(HCl/H_2) ~ (0.5-5.0) x 10^(-8), depending on the density of the emitting region. This is approximately an order of magnitude below previous theoretical estimates and a factor of 3-30 below the cosmic abundance of Cl. Recent laboratory work suggests that the lowered fractional abundance of HCl is caused by a combination of depletion onto grains with gas-phase loss processes such as the reaction of HCl with C^+

    First detection of the ground-state J_K = 1_0 → 0_0 submillimeter transition of interstellar ammonia

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    The J_K = 1_0 → 0_0 transition of ammonia at 572.5 GHz has been detected in OMC-1 from NASA's Kuiper Airborne Observatory. The central velocity of the line (V_(LSR)≈ 9 km s^(-1)) indicates that it originates in the molecular cloud material, not in the hot core. The derived filling factor of ≳ 0.09 in a 2' beam implies a source diameter of ≳ 35" if it is a single clump. This clump area is much larger than that derived from observations of the 1_1 inversion transition. The larger optical depth in the 1_0 → 0_0 transition (75-350) can account for the increased source area and line width as compared with those seen in the 1_1 inversion transition

    First detection of the ground state JK = 1 sub 0 going to 0 sub 0 submillimeter transition of interstellar ammonia

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    The JK = 1 sub 0 approaching O sub 0 transition of ammonia at 572.5 GHz was detected in OMC-1 from NASA's Kuiper Airborne Observatory. The central velocity of the line (VLSR approximately = 9 km/s) indicates that it originates in the molecular cloud material, not the hot core. The derived filling factor of approximately 0.09 in a 2' beam implies a source diameter of approximately 35" if it is a single clump. This clump area is much larger than that derived from observations of the sub 1 inversion transition. The larger optical depth in the 1 sub 0 approaching 0 sub 0 transition (75-350) can account for the increased source area and linewidth as compared with those seen in the 1 sub 0 inversion transition

    A Multi-Generational Workplace Perspective: The Phenomenon of the Millennial African Immigrant Woman in Corporate America

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    This research and capstone explore how the experiences of Ghanaian and Nigerian first andsecond-generation immigrant women in the U.S. workplace differ from their Black American counterparts. This research specifically focuses on the experiences of millennials (born between 1981 – 1996), Black, women, who had at least three years of work experience. Through interviews including first andsecond-generation Ghanaian and Nigerian women and multi-generational Black American women, the capstone examines issues that include the stereotype threat, emotional tax, and the model minority myth. With the growth in the Black immigrant population over the last century, it is imperative that companies realize the nuanced differences present in these groups (Kposowa, 2002). Many of the women who participated in this study mentioned instances where stereotype threat and emotional tax negatively affected their workplace experiences. In all ten interviews, each woman had at least one instance where she felt that her race played in part in her workplace treatment. All the women felt as though they had to be acutely aware of how they presented themselves in the workplace. There were, however, slight differences in their workplace and educational social experiences, depending on whether they were Black American, or a first or second-generation Ghanaian or Nigerian millennial, immigrant, woman

    HCl Absorption Toward Sagittarius B2

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    We have detected the 626 GHz J = 1 → 0 transition of hydrogen chloride (H^(35)Cl) in absorption against the dust continuum emission of the molecular cloud Sagittarius B2. The observed line shape is consistent with the blending of the three hyperfine components of this transition by the velocity profile of Sgr B2 observed in other species. The apparent optical depth of the line is t ≈ 1, and the minimum HCl column density is 1.6 x 10^(14) cm^(-2) A detailed radiative transfer model was constructed which includes collisional and radiative excitation, absorption and emission by dust, and the radial variation of temperature and density. Good agreement between the model and the data is obtained for HCl/H_2 ~ 1.1 x 10^(-9). Comparison of this result to chemical models indicates that the depletion factor of gas-phase chlorine is between 50–180 in the molecular envelope surrounding the SgrB2(N) and (M) dust cores

    Ground-based searches for interstellar H_(2)D^+

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    We present ground-based searches for the 1_(10) - 1_(11) line of interstellar H_(2)D^(+) at 372 GHz which are more sensitive than those obtained from the Kuiper Airborne Observatory by factors of 3-4 for extended sources and by more than two orders of magnitude for compact sources. The line was not detected in a variety of interstellar clouds, including NGC 2264 toward which a possible detection had been suggested previously. The inferred H_(2)D^(+) abundance limits of 10^(-10) - 10^(-11) are still consistent with, but approach the abundances predicted by chemical models. Simultaneous observations of the DCO^(+) 3-2 and N_(2)H^(+) 4-3 lines have been used to place additional limits on the H_(3)^(+) abundance, and suggest 10^(-11) < x(H_(3)^(+))< 10^(-9). The N_(2)H^(+) data also indicate that for NGC 2264, but perhaps not for the other sources, gas-phase N_2 contains a substantial fraction of the available nitrogen in the cloud
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