145 research outputs found
The Range Safety Problem, A Thorn In The Flesh
The range safety problem is truly a thorn in the flesh to the user of the missile test ranges. The range user has one objective in mind: to get his missile off the ground and successfully complete his test objectives. Any thing that interferes with that objective is, to him, an evil he can do without. Range Safety has often been considered such an evil - albeit a necessary one. Possibly a misunderstanding of the problem is the basis for this feeling. This paper endeavors to present the problem in its proper perspective by defining the problem and presenting the means used by the Range Safety Division of the ranges to assess, control and/or eliminate the risks involved in a missile flight. It starts by describing a typical flight, defines the problem, describes how the problem is controlled, and how it is qualitatively measured.
This paper is limited to flight safety, i.e., that period which commences with liftoff of the missile. Pad safety and ground safety (e.g., propellant handling) are not d i scussed.
The discussions herein are general insofar as possible. When it becomes necessary to be specific, examples are chosen from the AFETR, since we are more familiar with the operating procedures and philosophies of that range. They are, however, typical of all U.S. test ranges.
We have tried throughout this report to differentiate between range safety as a function of the range, and Range Safety as a personification of that function in the Range Safety Division by means of capital letters
Metal-insulator-metal nanoresonators - Strongly confined modes for high surface sensitivity
Photonic and plasmonic refractive index sensors are able to detect increasingly smaller refractive index changes and concentrations of clinically relevant substances. They typically exploit optical resonances and aim to maximise the field overlap with the analyte in order to achieve high sensitivity. Correspondingly, they operate on the basis of maximizing the bulk sensitivity, which favours spatially extended modes. We note that this strategy, counter-intuitively, is not necessarily suitable for detecting biomolecules and one should focus on the surface sensitivity instead. Here, we show that by confining light tightly in metal-insulator-metal (MIM) nanoresonators, the surface sensitivity is significantly increased despite a clear decrease in bulk sensitivity. In particular, we experimentally show the operation of third order MIM resonators which support both extended surface plasmon polariton (SPP) modes and localized MIM modes. We are able to demonstrate that the MIM mode has a sensitivity of 55 nm/RIU to a 10 nm layer, which is approximately twice as high as that of the SPP mode. Overall, our work emphasizes the importance of the surface sensitivity over the more commonly used bulk sensitivity and it shows a novel approach for improving it. These insights are highly relevant for the design of next generation optical biosensors
The Radial Extent and Warp of the Ionized Galactic Disk. I. A VLBA Survey of Extragalactic Sources Toward the Anticenter
We report multifrequency Very Long Baseline Array observations of twelve
active galactic nuclei seen toward the Galactic anticenter. All of the sources
are at |b| < 10 degrees and seven have |b| < 0.5 degrees. Our VLBA observations
can detect an enhancement in the angular broadening of these sources due to an
extended H II disk, if the orientation of the H II disk in the outer Galaxy is
similar to that of the H I disk. Such an extended H II disk is suggested by the
C IV absorption in a quasar's spectrum, the appearance of H I disks of nearby
spiral galaxies, and models of Ly-alpha cloud absorbers and the Galactic
fountain. We detect eleven of the twelve sources at one or more frequencies;
nine of the sources are compact and suitable for an angular broadening
analysis. A preliminary analysis of the observed angular diameters suggests
that the H II disk does not display considerable warping or flaring and does
not extend to large Galactocentric distances (R >~ 100 kpc). A companion paper
(Lazio & Cordes 1997) combines these observations with those in the literature
and presents a more comprehensive analysis.Comment: 19 pages, LaTeX2e with AASTeX macro aaspp4, accepted for publication
in ApJS, Vol. 115, 1998 April; Figures 1, 3, and 4 included, for figures of
individual sources see
http://astrosun.tn.cornell.edu/students/lazio/Anticenter/anticenterI.htm
Daily modulation due to channeling in direct dark matter crystalline detectors
The channeling of the ion recoiling after a collision with a WIMP in direct
dark matter crystalline detectors produces a larger scintillation or ionization
signal than otherwise expected. Channeling is a directional effect which
depends on the velocity distribution of WIMPs in the dark halo of our Galaxy
and could lead to a daily modulation of the signal. Here we compute upper
bounds to the expected amplitude of daily modulation due to channeling using
channeling fractions that we obtained with analytic models in prior work. After
developing the general formalism, we examine the possibility of finding a daily
modulation due to channeling in the data already collected by the DAMA/NaI and
DAMA/LIBRA experiments. We find that even the largest daily modulation
amplitudes (of the order of 10% in some instances) would not be observable for
WIMPs in the standard halo in the 13 years of data taken by the DAMA
collaboration. For these to be observable the DAMA total rate should be 1/40 of
what it is or the total DAMA exposure should be 40 times larger. The daily
modulation due to channeling will be difficult to measure in future
experiments. We find it could be observed for light WIMPs in solid Ne, assuming
no background.Comment: 29 pages, 15 figures. v3: version accepted by PRD. Minor corrections
made, corrected Eq. 12 and 13 and Figs. 2, 3.a, and 4.a, corrected Eqs. 27-38
by a factor of 2, added the observability condition for solid N
Fandubbing
This chapter provides an overview of fandubbing, understood largely as a phenomenon encompassing a myriad of dubbing practices undertaken by amateur or non-expert users. The focus is placed on its origins, evolution and characteristics, and on the motivations of those involved in these underexplored fandom-related practices. This is achieved drawing on Bañosâ research on this topic, on the few academic publications dealing with this phenomenon, and on non-academic sources providing useful insight into these practices and revealing the point of view of the creators of fandubs. The chapter also highlights the differences between fandubs and official dubbing, and identifies areas of future research
Admission decisions following contact with an emergency mental health assessment and intervention service.
AIMS: To define the demographic and clinical profile of individuals referred to an emergency mental health assessment team. To identify factors associated with being admitted to inpatient psychiatric services or not admitted following an emergency assessment. BACKGROUND: Crisis resolution and home treatment services are being developed across the UK, targeted towards people with severe mental health problems, who would otherwise require hospitalization. Further information about people presenting to an emergency mental health assessment service may clarify the skills that are required to deliver effective crisis resolution and home treatment services. METHOD: Over a six-month period referrals to, and admission decisions by, an emergency mental health assessment team were recorded. Measures used were the Health of the Nation Outcome Scale and the Crisis Triage Rating Scale. Age, sex and postcode data were recorded. Postcode data were used to identify the Townsend Deprivation Index for each individual. Reasons given for the referral were categorized. A preliminary descriptive analysis was performed for all people referred. The Demographic and clinical characteristics of referrals admitted and not admitted were then compared. A multivariate logistic regression was performed in order to investigate the possible impact of demographic and clinical characteristics on admission status. RESULTS: A total of 375 individuals were referred. Forty-eight (12.8%) were admitted. Higher referral rates were significantly associated with more deprived areas of the city. Referrers most frequently identified suicide risk as the reason for referral, followed by deterioration of an existing serious mental health problem. The mean Health of the Nation Outcome Scale score of all people referred was 10.5. Those admitted had a significantly greater mean Health of the Nation Outcome Scale score than those not admitted. The mean Crisis Triage Rating Scale score of all people referred was 11.0. Those admitted had a significantly lower (worse) mean Crisis Triage Rating Scale score than those not admitted. Individuals with lower Crisis Triage Rating Scale scores tended to have a higher (more deprived) Townsend index scores. Crisis Triage Rating Scale and Health of the Nation Outcome Scale scores were significantly negatively correlated. Conclusions. Crisis resolution and home treatments need to target areas of greatest deprivation. Social interventions will be important. Presentations related to suicide risk are likely to be common. The Crisis Triage Rating Scale may be a useful brief alternative to Health of the Nation Outcome Scale. RELEVANCE TO CLINICAL PRACTICE: This study highlights the valuable role of mental health nurses in frontline emergency mental health care in particular mental health nurses skills in conducting a risk assessment in an emergency
Solitary and cnoidal wave scattering by a submerged horizontal plate in shallow water
Solitary and cnoidal wave transformation over a submerged, fixed, horizontal rigid plate is studied by use of the nonlinear, shallow-water Level I Green-Naghdi (GN) equations. Reflection and transmission coefficients are defined for cnoidal and solitary waves to quantify the nonlinear wave scattering. Results of the GN equations are compared with the laboratory experiments and other theoretical solutions for linear and nonlinear waves in intermediate and deep waters. The GN equations are then used to study the nonlinear wave scattering by a plate in shallow water. It is shown that in deep and intermediate depths, the wave-scattering varies nonlinearly by both the wavelength over the plate length ratio, and the submergence depth. In shallow water, however, and for long-waves, only the submergence depth appear to play a significant role on wave scattering. It is possible to define the plate submergence depth and length such that certain wave conditions are optimized above, below, or downwave of the plate for different applications. A submerged plate in shallow water can be used as a means to attenuate energy, such as in wave breakers, or used for energy focusing, and in wave energy devices
âUnboxingâ videos: co-construction of the child as cyberflĂąneur
This paper draws on data from a study of a four-year-old child, Gareth, in his first year of formal schooling in England. The aim of the study was to identify the nature of Gareth's literacy practices across home and school spaces. The focus for this paper is an analysis of one aspect of Gareth's home digital literacy practices: his repeated viewings at home of âunboxingâ videos on YouTube. These include videos that feature the unpacking of commercial products. It is argued that the child viewer/reader is co-constructed in these practices as cyberflĂąneur and that this mode of cultural transmission is a growing feature of online practices for this age group in the twenty-first century. The paper addresses issues concerning young children's online practices and their relationship to material culture before analysing the growth of interest in peer-to-peer textual production and consumption in the digital age
Constraints on dark matter models from a Fermi LAT search for high-energy cosmic-ray electrons from the Sun
During its first year of data taking, the Large Area Telescope (LAT) onboard
the Fermi Gamma-Ray Space Telescope has collected a large sample of high-energy
cosmic-ray electrons and positrons (CREs). We present the results of a
directional analysis of the CRE events, in which we searched for a flux excess
correlated with the direction of the Sun. Two different and complementary
analysis approaches were implemented, and neither yielded evidence of a
significant CRE flux excess from the Sun. We derive upper limits on the CRE
flux from the Sun's direction, and use these bounds to constrain two classes of
dark matter models which predict a solar CRE flux: (1) models in which dark
matter annihilates to CREs via a light intermediate state, and (2) inelastic
dark matter models in which dark matter annihilates to CREs.Comment: 18 pages, 8 figures, accepted for publication in Physical Review D -
contact authors: Francesco Loparco ([email protected]), M. Nicola Mazziotta
([email protected]) and Jennifer Siegal-Gaskins ([email protected]
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