1,215 research outputs found
Development and testing of an image tube camera and spectrograph Final report
Image tube camera and spectrograph for observing artificial auror
Development and testing of an image tube camera and spectrograph Quarterly progress report, period ending 31 Mar. 1969
Electron beam field mapping with aid of image tube cameras and spectrometer
Cost model relationships between textile manufacturing processes and design details for transport fuselage elements
Textile manufacturing processes offer potential cost and weight advantages over traditional composite materials and processes for transport fuselage elements. In the current study, design cost modeling relationships between textile processes and element design details were developed. Such relationships are expected to help future aircraft designers to make timely decisions on the effect of design details and overall configurations on textile fabrication costs. The fundamental advantage of a design cost model is to insure that the element design is cost effective for the intended process. Trade studies on the effects of processing parameters also help to optimize the manufacturing steps for a particular structural element. Two methods of analyzing design detail/process cost relationships developed for the design cost model were pursued in the current study. The first makes use of existing databases and alternative cost modeling methods (e.g. detailed estimating). The second compares design cost model predictions with data collected during the fabrication of seven foot circumferential frames for ATCAS crown test panels. The process used in this case involves 2D dry braiding and resin transfer molding of curved 'J' cross section frame members having design details characteristic of the baseline ATCAS crown design
V4332 Sagittarii revisited
The eruption of V4332 Sgr discovered in February 1994 shows striking
similarities to that of V838 Mon started in January 2002. The nature of these
eruptions is, however, enigmatic and unclear. We present new photometric and
spectroscopic data on V4332 Sgr obtained in April-May 2003 at the SAAO. The
obtained spectrum shows an unusual emission-line component superimposed on an
early M-type stellar spectrum. The emission-line spectrum is of very low
excitation and is dominated by lines from neutral elemets (NaI, FeI, CaI) and
molecular bands (TiO, ScO, AlO). We also analyse all the observational data,
mainly photometric measurements, available for V4332 Sgr. This allows us to
follow the evolution of the effective temperature, radius and luminosity of the
object since February 1994 till 2003. We show that the observed decline of
V4332 Sgr can be accounted for by a gravitational contraction of an inflated
stellar envelope. The combined optical and infrared photometry in 2003 shows
that apart from the M-type stellar component there is a strong infrared excess
in the KLM bands. This excess was absent in the 2MASS measurements done in 1998
but was probably starting to appear in K in 1999 when the object was observed
in the DENIS survey. We interpret the results in terms of a stellar merger
scenario proposed by Soker & Tylenda. The infrared excess is likely to be due
to a disc-like structure which is either of protostellar nature or has been
produced during the 1994 eruption and stores angular momentum from the merger
event.Comment: 11 pages, 5 figures, accepted in Astronomy & Astrophysic
A Mixed-Methods Analysis of Coercive Control and COVID-19 Stress Among Black Women Experiencing Intimate Partner Violence During the COVID-19 Pandemic
Objective: During times of crises, women are at elevated risk for intimate partner violence (IPV), but extant discourse fails to consider how this landscape amplifies disparities for Black women. This study examined the prevalence and associations of COVID-19 pandemic–specific coercive control and COVID-19–related stress among Black women experiencing IPV. Methods: Fifty-five Black women reporting past-year IPV participated in a prospective cohort study in 2020 and completed surveys on pandemic-specific coercive control, COVID-19–related stress, and sociodemographic characteristics. A subset of 15 participants completed semi-structured interviews in 2021. We conducted multivariable regression analyses to examine associations between coercive control and stress. We used interpretive phenomenological analysis to contextualize women’s experiences of coercive control and stress during the pandemic. Results: In the past 3 months, 76% (42 of 55) of women had a partner blame them for exposing them to COVID-19, 74% (41 of 55) had a partner minimize their pandemic concerns, and 52% (29 of 55) had a partner prevent them from getting a COVID-19 test. A higher average of pandemic-specific coercive control was associated with greater severity of COVID-19–related traumatic stress (b [SE] = 0.033 [0.009]; P =.001) and socioeconomic consequences related to COVID-19 (b [SE] = 0.019 [0.008]; P =.03). We identified 3 superordinate themes that illustrated Black women’s experiences: (1) coercive control, (2) pandemic-driven shifts in relational context, and (3) women’s structural and psychosocial stressors. Conclusions: Experiencing coercive control during the pandemic interfered with Black women’s engagement in preventive behaviors, which exacerbated distress. Intersectional public health efforts should address sociostructural and relational factors to prevent coercive control and stress among Black women experiencing IPV
Comparison of multiple methods for identification of hyperprolactinemia in the presence of macroprolactin
Macroprolactin is a large, heterogeneous form of prolactin with limited bioavailability. Detection of macroprolactin by different immunoassays varies widely. The objectives of this study were to determine the immunoreactivity of macroprolactin by the Ortho Clinical Diagnostics Vitros ECi prolactin immunoassay, establish the most effective method for interpreting the prolactin concentration after PEG-precipitation, and correlate the clinical features of hyperprolactinemia with the presence of macroprolactin
Triggered massive-star formation on the borders of Galactic HII regions. IV- Star formation at the periphery of Sh2-212
Aims: We wish to establish whether sequential star formation is taking place
at the periphery of the Galactic HII region Sh2-212.
Methods: We present CO millimetre observations of this region obtained at the
IRAM 30-m telescope to investigate the distribution of associated molecular
material. We also use deep JHK observations obtained at the CFHT to study the
stellar content of the region, and radio observations obtained at the VLA to
look for the presence of an ultra-compact (UC) HII region and for maser
emission.
Results: In the optical, Sh2-212 is spherically symmetric around its central
exciting cluster. This HII region is located along a molecular filament. A
thin, well-defined half ring of molecular material surrounds the brightest part
of the HII region at the rear and is fragmented. The most massive fragment
(~200 solar masses) contains a massive young stellar object displaying a
near-IR excess; its spectral energy distribution indicates a high-mass
(~14solar masses), high-temperature (~30000K), and high-luminosity (~17000
solar luminosities) source. This object ionizes a UC HII region.
Conclusions: Sh2-212 is a good example of massive-star formation triggered
via the collect and collapse process. The massive YSO observed at its periphery
is a good candidate for a massive star formed in isolation.Comment: 12 pages, 14 figures. To be published in A&
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