1,227 research outputs found
Measured optical absorption coefficients for uranium plasmas
Absolute emissivities of uranium plasmas in gas driven shock tub
Development of a spectroscopic shock tube
Gas spectroscopic tube and component equipment instrumentation for radiative transfer experiment
Bistatic LIDAR experiment proposed for the shuttle/tethered satellite system missions
A new experiment concept has been proposed for the shuttle/tethered satellite system missions, which can provide high resolution, global density mappings of certain ionospheric species. The technique utilizes bistatic LIDAR to take advantage of the unique dual platform configuration offered by these missions. A tuned, shuttle-based laser is used to excite a column of the atmosphere adjacent to the tethered satellite, while triangulating photometic detectors on the satellite are employed to measure the fluorescence from sections of the column. The fluorescent intensity at the detectors is increased about six decades over both ground-based and monostatic shuttle-based LIDAR sounding of the same region. In addition, the orbital motion of the Shuttle provides for quasi-global mapping unattainable with ground-based observations. Since this technique provides such vastly improved resolution on a synoptic scale, many important middle atmospheric studies, heretofore untenable, may soon be addressed
“I Feel Like It’s One of Those Things that Everyone Feels the Same Way About, No One Wants to Discuss It”: A Qualitative Examination of Female College Students’ Pap Smear Experience
The purpose of this study was to examine female college students’ Pap smear experience and communication with their provider before, during, and after the exam. In fall 2019, 158 female college students completed an online survey with closed and open-ended questions. Open-ended responses from participants reporting a previous Pap smear (n=36) were qualitatively analyzed to generate themes to explain female college students’ Pap smear experience and communication behavior with their provider before, during, and after the exam. The main themes identified included: Uncomfortable, Low Patient Engagement, Provider Support, and Provider Trust. Female college students overwhelmingly reported discomfort around the exam and were unaware of how to communicate with their provider; however, participants reported satisfaction with their care when the provider offered support and guidance. Findings suggest a need to develop strategies to address discomfort and enhance female college students’ communication skills with providers concerning the Pap smear exam
Influence of Equatorial Diatom Processes on Si Deposition and Atmospheric CO(2) Cycles at Glacial/Interglacial Timescales
The causes of the glacial cycle remain unknown, although the primary driver is changes in atmospheric CO(2), likely controlled by the biological pump and biogeochemical cycles. The two most important regions of the ocean for exchange of CO(2) with the atmosphere are the equatorial Pacific and the Southern Ocean ( SO), the former a net source and the latter a net sink under present conditions. The equatorial Pacific has been shown to be a Si(OH)(4)-limited ecosystem, a consequence of the low source Si(OH)(4) concentrations in upwelled water that has its origin in the SO. This teleconnection for nutrients between the two regions suggests an oscillatory relationship that may influence or control glacial cycles. Opal mass accumulation rate (MAR) data and delta(15)N measurements in equatorial cores are interpreted with predictions from a one- dimensional Si(OH)(4)-limited ecosystem model (CoSINE) for the equatorial Pacific. The results suggest that equatorial Pacific surface CO(2) processes are in opposite phase to that of the global atmosphere, providing a negative feedback to the glacial cycle. This negative feedback is implemented through the effect of the SO on the equatorial Si(OH)(4) supply. An alternative hypothesis, that the whole ocean becomes Si(OH)(4) poor during cooling periods, is suggested by low opal MAR in cores from both equatorial and Antarctic regions, perhaps as a result of low river input. terminations in this scenario would result from blooms of coccolithophorids triggered by low Si(OH)(4) concentrations
Factors Associated with Standing Desk Use in the Workplace: Implications for Workplace Health Promotion Programs and Interventions
The purpose of this study was to explore what sociodemographic, psychosocial, and behavioral factors were associated with standing desk use in the workplace among full-time non-instructional staff at a large, public university in the south-central United States. Data were collected using an online survey in Spring 2019 that contained items to assess sociodemographic variables, psychosocial factors, physical activity, and standing desk use. Participants (n = 381) were predominantly female (79.1%), white (91.7%), and 23.9% used a standing desk. In the binary logistic regression model, sedentary behavior awareness (OR = 1.11; 95% CI:1.04,1.18), self-efficacy (OR = 1.06; 95%CI:1.03,1.10), and salaried staff classification (OR = 1.99; 95%CI:1.19,3.34) were significantly associated with standing desk use (R2 = 0.16; p \u3c .001). Findings from this study not only identify important psychosocial factors that may be targeted in future standing desk-based interventions but also highlight specific subgroups of employees that should be targeted in intervention recruitment
Experimental constraints on a dark matter origin for the DAMA annual modulation effect
A claim for evidence of dark matter interactions in the DAMA experiment has
been recently reinforced. We employ a new type of germanium detector to
conclusively rule out a standard isothermal galactic halo of Weakly Interacting
Massive Particles (WIMPs) as the explanation for the annual modulation effect
leading to the claim. Bounds are similarly imposed on a suggestion that dark
pseudoscalars mightlead to the effect. We describe the sensitivity to light
dark matter particles achievable with our device, in particular to
Next-to-Minimal Supersymmetric Model candidates.Comment: v4: introduces recent results from arXiv:0807.3279 and
arXiv:0807.2926. Sensitivity to pseudoscalars is revised in light of the
first. Discussion on the subject adde
A pulsed, mono-energetic and angular-selective UV photo-electron source for the commissioning of the KATRIN experiment
The KATRIN experiment aims to determine the neutrino mass scale with a
sensitivity of 200 meV/c^2 (90% C.L.) by a precision measurement of the shape
of the tritium -spectrum in the endpoint region. The energy analysis of
the decay electrons is achieved by a MAC-E filter spectrometer. To determine
the transmission properties of the KATRIN main spectrometer, a mono-energetic
and angular-selective electron source has been developed. In preparation for
the second commissioning phase of the main spectrometer, a measurement phase
was carried out at the KATRIN monitor spectrometer where the device was
operated in a MAC-E filter setup for testing. The results of these measurements
are compared with simulations using the particle-tracking software
"Kassiopeia", which was developed in the KATRIN collaboration over recent
years.Comment: 19 pages, 16 figures, submitted to European Physical Journal
- …