SBASI: Actuated pyrotechnic time delay initiator

A precision pyrotechnic time delay initiator for missile staging was developed and tested. Incorporated in the assembly is a single bridgewire Apollo standard initiator (SBASI) for initiation, a through-bulkhead-initiator to provide isolation of the SBASI output from the delay, the pyrotechnic delay, and an output charge. An attempt was made to control both primary and secondary variables affecting functional performance of the delay initiator. Design and functional limit exploration was performed to establish tolerance levels on manufacturing and assembling operations. The test results demonstrate a 2% coefficient of variation at any one temperature and an overall 2.7% coefficient of variation throughout the temperature range of 30 to 120 F. Tests were conducted at simulated operational altitude from sea level to 200,000 feet

Compact steep-spectrum sources from the S4 sample

We present the results of 5-GHz observations with the VLA A-array of a sample of candidate Compact Steep Spectrum sources (CSSs) selected from the S4 survey. We also estimate the symmetry parameters of high-luminosity CSSs selected from different samples of radio sources, and compare these with the larger sources of similar luminosity to understand their evolution and the consistency of the CSSs with the unified scheme for radio galaxies and quasars. The majority of CSSs are likely to be young sources advancing outwards through a dense asymmetric environment. The radio properties of CSSs are found to be consistent with the unified scheme, in which the axes of the quasars are observed close to the line of sight, while radio galaxies are observed close to the plane of the sky.Comment: accepted for publication in mnras; 8 pages, figure 1 with 21 images, and two additional figures; 2 table

Investigating deaf children’s plural and diverse use of sign and spoken languages in a super diverse context.

This paper examines the meaning of plurality and diversity with respect to deaf children’s sign and spoken language exposure and repertoire within a super diverse context. Data is drawn from a small-scale project that took place in the North of England in a Local Authority (LA) site for deaf education. The project documented the language landscape of this site and gathered five individual case studies of deaf children to examine their plural and diverse language practices at home and at school. Analysis of the language landscape and case studies from this context is undertaken in order to define and exemplify deaf children’s language plurality and diversity in terms of context and individual experience. Concepts of repertoire are explored with particular reference to the unique type of translanguaging that the plural use of sign and spoken languages affords.Implications of these preliminary insights are discussed in terms of the development of methodologies that are sensitive to the particular translanguaging practices of deaf children, and approaches to pedagogy that are appropriately nuanced and responsive to deaf children’s language plurality and diversity

The ‘total cost of publication’ in a hybrid open-access environment: Institutional approaches to funding journal article-processing charges in combination with subscriptions

As open-access (OA) publishing funded by article-processing charges (APCs) becomes more widely accepted, academic institutions need to be aware of the ‘total cost of publication’, comprising subscription costs plus APCs and additional administration costs. This study analyses data from 23 UK institutions covering the period 2007 to 2014 modelling the total cost of publication (TCP). It shows a clear rise in centrally-managed APC payments from 2012 onwards, with payments projected to increase further. As well as evidencing the growing availability and acceptance of OA publishing, these trends reflect particular UK policy developments and funding arrangements intended to accelerate the move towards OA publishing (‘Gold’ OA). Whilst the mean value of APCs has been relatively stable, there was considerable variation in APC prices paid by institutions since 2007. In particular, ‘hybrid’ subscription/OA journals were consistently more expensive than fully-OA journals. Most APCs were paid to large ‘traditional’ commercial publishers who also received considerable subscription income. New administrative costs reported by institutions varied considerably. The total cost of publication modelling shows that APCs are now a significant part of the TCP for academic institutions, in 2013 already constituting an average of 10% of the TCP (excluding administrative costs)

High resolution structural characterisation of laser-induced defect clusters inside diamond

Laser writing with ultrashort pulses provides a potential route for the manufacture of three-dimensional wires, waveguides and defects within diamond. We present a transmission electron microscopy (TEM) study of the intrinsic structure of the laser modifications and reveal a complex distribution of defects. Electron energy loss spectroscopy (EELS) indicates that the majority of the irradiated region remains as $sp^3$ bonded diamond. Electrically-conductive paths are attributed to the formation of multiple nano-scale, $sp^2$-bonded graphitic wires and a network of strain-relieving micro-cracks

Bench-to-bedside review: The value of cardiac biomarkers in the intensive care patient

The use of cardiac biomarkers in the intensive care setting is gaining increasing popularity. There are several reasons for this increase: there is now the facility for point-of-care biomarker measurement providing a rapid diagnosis; biomarkers can be used as prognostic tools; biomarkers can be used to guide therapy; and, compared with other methods such as echocardiography, the assays are easier and much more affordable. Two important characteristics of the ideal biomarker are disease specificity and a linear relationship between the serum concentration and disease severity. These characteristics are not present, however, in the majority of biomarkers for cardiac dysfunction currently available. Those clinically useful cardiac biomarkers, which naturally received the most attention, such as troponins and B-type natriuretic peptide, are not as specific as was originally thought. In the intensive care setting, it is important for the user to understand the degree of specificity of these biomarkers and that the interpretation of the results should always be guided by other clinical information. The present review summarizes the available biomarkers for different cardiac conditions. Potential biomarkers under evaluation are also briefly discussed

Four-dimensional light shaping: manipulating ultrafast spatio-temporal foci in space and time

Spectral dispersion of ultrashort pulses allows simultaneous focusing of light in both space and time creating so-called spatio-temporal foci. Such space-time coupling may be combined with existing holographic techniques to give a further dimension of control when generating focal light fields. It is shown that a phase-only hologram placed in the pupil plane of an objective and illuminated by a spatially chirped ultrashort pulse can be used to generate three dimensional arrays of spatio-temporally focused spots. Exploiting the pulse front tilt generated at focus when applying simultaneous spatial and temporal focusing (SSTF), it is possible to overlap neighbouring foci in time to create a smooth intensity distribution. The resulting light field displays a high level of axial confinement, with experimental demonstrations given through two-photon microscopy and non-linear laser fabrication of glass

Designing Performer Training: Digital Encounters with Things and People

This article investigates how digital technologies can be used to enhance the relational aspects of performer training. Saner and Robinson reflect on a practice as research project, Enactive Encounters, where they use poor technology and everyday objects to create participatory learning environments. The teacher- student relationship is challenged and transformed into playful interactions between participants through enactive encounters that aim to embody different aspects of specific training practices. Keywords: digital training, relational pedagogy, enactivism

Planar polymer waveguides with a graded-index profile resulting from intermixing of methacrylates in closed microchannels

Graded-index waveguides are known to exhibit lower losses and considerably larger bandwidths compared to step-index waveguides. The present work reports on a new concept for realizing such waveguides on a planar substrate by capillary filling microchannels (cladding) with monomer solution (core). A graded-index profile is obtained by intermi xing between the core and cladding material at the microchannel interface. To this end, various ratios of methyl methacrylate (MMA) and octafluoropentyl methacrylate (OFPMA) were evaluated as starting monomers and the results showed that the polymers P50:50 (50:50 MMA:OFPMA) and P0:100 (100% OFPMA) were suitable to be applied as waveguide core and cladding material respectively. Light guiding in the resulting P50:50/P0:100 waveguides was demonstrated and the refractive-index profile was quantified and compared with that of conventional step-index waveguides. The results for both cases were clearly different and a gradual refractive index transition between the core and cladding was found for the newly developed waveguides. Although the concept has been demonstrated in a research environment, it also has potential for upscaling by employing drop-on-demand dispensing of polymer waveguide material in pre-patterned microchannels, for example in a roll-to-roll environment