Relative equilibria for the generalized rigid body

This paper gives necessary and sufficient conditions for the (n-dimensional) generalized free rigid body to be in a state of relative equilibrium. The conditions generalize those for the case of the three-dimensional free rigid body, namely that the body is in relative equilibrium if and only if its angular velocity and angular momentum align, that is, if the body rotates about one of its principal axes. For the n-dimensional rigid body in the Manakov formulation, these conditions have a similar interpretation. We use this result to state and prove a generalized Saari’s Conjecture (usually stated for the N-body problem) for the special case of the generalized rigid body

A single case study of articulatory adaptation during acoustic mimicry

The distribution of fine-grained phonetic variation can be observed in the speech of members of welldefined social groups. It is evident that such variation must somehow be able to propagate through a speech community from speaker to hearer. However, technological barriers have meant that close and direct study of the articulatory links of this speaker-hearer chain has not, to date, been possible. We present the results of a singlecase study using an ultrasound-based method to investigate temporal and configurational lingual adaptation during mimicry. Our study focuses on allophonic variants of postvocalic /r/ found in speech from Central Scotland. Our results show that our informant was able to adjust tongue gesture timing towards that of the stimulus, but did not alter tongue configuration

Articulatory insights into language variation and change: preliminary findings from an ultrasound study of derhoticization in Scottish English

<p>Scottish English is often cited as a rhotic dialect of English. However, in the 70s and 80s, researchers noticed that postvocalic /r/ was in attrition in Glasgow (Macafee, 1983) and Edinburgh (Romaine, 1978; Johnston and Speitel 1983). Recent research (Stuart-Smith, 2003) confirms that postvocalic /r/ as a canonical phonetically rhotic consonant is being lost in working-class Glaswegian speech. However, auditory and acoustic analysis revealed that the situation was more complicated than simple /r/ vs. zero variation. The derhoticized quality of /r/ seemed to vary socially; in particular male working class speakers often produced intermediate sounds that were difficult to identify. It is clear that although auditory and acoustic analysis are useful, they can only hint at what is going on in the vocal tract. A direct articulatory study is thus motivated.</p> <p>Instrumental phonetic studies that examine the vocal tract during the production of sustained rhotic consonants and in laboratory-based studies of American English /r/ have identified a complex relationship between articulation and acoustics, including articulatory differences with minimal acoustic consequences (starting with Delattre and Freeman, 1968). In other words, different gestural configurations can be used to generate a canonically rhotic consonant. A pilot study (Scobbie and Stuart-Smith, 2006) using Ultrasound Tongue Imaging (UTI) with a Scottish vernacular speaker revealed something rather different: the occurrence of a strong articulatory retroflex tongue motion, which generated little or no rhotic acoustic consequences because it was timed to occur after phonation had ceased, before pause. This tongue motion was found in a speaker who was weakly rhotic. Thus we may have a situation in which acoustic differences with a sociolinguistic function have, in some prosodic contexts, imperceptible articulatory differences in tongue position, though timing will vary. The situation of language variation and change in Scotland means that an articulatory/acoustic study is likely to give very different results to similar studies of rhotic speakers in the USA (Mielke, Twist, and Archangeli, 2006), and be particularly relevant to understanding social variation.</p> <p>Ultrasound is non-invasive and portable and therefore has great potential as an instrumental method for studying aspects of socially stratified variation: articulatory data can be physically collected in every-day social settings. However the technique requires refinement for effective use in recording locations outside the laboratory (e.g. in school, at home), and the potential impact of using the equipment on speech is not known. Gick (2002) suggest methods for fieldwork, but we are not aware of any study which attempts to quantify the effects of the technique on vernacular speakers.</p> <p>Ultrasound is non-invasive and portable and therefore has great potential as an instrumental method for studying aspects of socially stratified variation: articulatory data can be physically collected in every-day social settings. However the technique requires refinement for effective use in recording locations outside the laboratory (e.g. in school, at home), and the potential impact of using the equipment on speech is not known. Gick (2002) suggest methods for fieldwork, but we are not aware of any study which attempts to quantify the effects of the technique on vernacular speakers.</p&gt

Dequantisation of the Dirac Monopole

Using a sheaf-theoretic extension of conventional principal bundle theory, the Dirac monopole is formulated as a spherically symmetric model free of singularities outside the origin such that the charge may assume arbitrary real values. For integral charges, the construction effectively coincides with the usual model. Spin structures and Dirac operators are also generalised by the same technique.Comment: 22 pages. Version to appear in Proc. R. Soc. London

The weld-brazing metal joining process

Superior mechanical properties were obtained in metal joints weld-brazed between faying surfaces. Weld-braze applications and advantages are listed

Uso de los ciclos de aprendizaje para la enseñanza de destrezas de razonamiento científico y de sistemas conceptuales

This paper deals with an important tool in science education, learning cycles. The author covers this topic through a historical perspective about their origins, a theoretical position about their use (covering the nature of declarative and procedural knowledge and the constructive process of formation of concepts and the relationship of the latter with conceptual change), and concludes with a description of the three types of learning cycles and their accomplishment of improving students' declarative and procedural knowledge. The examples along the text are specially devoted to biology

Thermally isolated deployable shield for spacecraft

A thermally isolated deployable shield for spacecraft is provided utilizing a plurality of lattice panels stowable generally against the craft and deployable to some fixed distance from the craft. The lattice panels are formed from replaceable shield panels affixed to lattice structures. The lattice panels generally encircle the craft providing 360 degree coverage therearound. Actuation means are provided from translating the shield radially outward from the craft and thermally isolating the shield from the craft. The lattice panels are relatively flexible, allowing the shield to deploy to variable diameters while retaining uniform curvature thereof. Restraining means are provided for holding the shield relatively tight in its stowed configuration. Close-out assemblies provide light sealing and protection of the annular spaces between the deployed shield and the crafts end structure

Double trouble: the impact of multimorbidity and deprivation on preference-weighted health related quality of life - a cross sectional analysis of the Scottish Health Survey

<b>Objective</b> To investigate the association between multimorbidity and Preference_Weighted Health Related Quality of Life (PW_HRQoL), a score that combines physical and mental functioning, and how this varies by socioeconomic deprivation and age.<p></p> <b>Design</b> The Scottish Health Survey (SHeS) is a cross-sectional representative survey of the general population which included the SF-12, a survey of HRQoL, for individuals 20 years and over.<p></p> <b>Methods</b> For 7,054 participants we generated PW_HRQoL scores by running SF-12 responses through the SF-6D algorithm. The resulting scores ranged from 0.29 (worst health) to 1 (perfect health). Using ordinary least squares, we first investigated associations between scores and increasing counts of longstanding conditions, and then repeated for multimorbidity (2+ conditions). Estimates were made for the general population and quintiles of socioeconomic deprivation. For multimorbidity, the analyses were repeated stratifying the population by age group (20--44, 45--64, 65+).<p></p> <b>Results</b> 45% of participants reported a longstanding condition and 18% reported multimorbidity. The presence of 1, 2, or 3+ longstanding conditions were associated with average reductions in PW_HRQoL scores of 0.081, 0.151 and 0.212 respectively. Reduction in scores associated with multimorbidity was 33% greater in the most deprived quintile compared to the least deprived quintile, with the biggest difference (80%) in the 20--44 age groups. There were no significant gender differences.<p></p> <b>Conclusions</b> PW_HRQoL decreases markedly with multimorbidity, and is exacerbated by higher deprivation and younger age. There is a need to prioritise interventions to improve the HRQoL for (especially younger) adults with multimorbidity in deprived areas

The platinum nuclei: concealed configuration mixing and shape coexistence

The role of configuration mixing in the Pt region is investigated. For this chain of isotopes, the nature of the ground state changes smoothly, being spherical around mass $A\sim 174$ and $A\sim 192$ and deformed around the mid-shell N=104 region. This has a dramatic effect on the systematics of the energy spectra as compared to the systematics in the Pb and Hg nuclei. Interacting Boson Model with configuration mixing calculations are presented for gyromagnetic factors, $\alpha$-decay hindrance factors, and isotope shifts. The necessity of incorporating intruder configurations to obtain an accurate description of the latter properties becomes evident.Comment: Accepted in Physical Review

Compendium of NASA Langley reports on hypersonic aerodynamics

Reference is made to papers published by the Langley Research Center in various areas of hypersonic aerodynamics for the period 1950 to 1986. The research work was performed either in-house by the Center staff or by other personnel supported entirely or in part by grants or contracts. Abstracts have been included with the references when available. The references are listed chronologically and are grouped under the following general headings: (1) Aerodynamic Measurements - Single Shapes; (2) Aerodynamic Measurements - Configurations; (3) Aero-Heating; (4) Configuration Studies; (5) Propulsion Integration Experiment; (6) Propulsion Integration - Study; (7) Analysis Methods; (8) Test Techniques; and (9) Airframe Active Cooling Systems