Nitric Oxide and Oxygen Air-Contamination Effects on Extinction Limits of Non-Premixed Hydrocarbon-Air Flames for a HIFiRE Scramjet

Unique nitric oxide (NO) and oxygen air-contamination effects on the extinction Flame Strength (FS) of non-premixed hydrocarbon (HC) vs. air flames are characterized for 7 gaseous HCs, using a new idealized 9.3 mm straight-tube Opposed Jet Burner (OJB) at 1 atm. FS represents a laminar strain-induced extinction limit based on cross-section-average air jet velocity, Uair, that sustains combustion of a counter jet of gaseous fuel just before extinction. Besides ethane, propane, butane, and propylene, the HCs include ethylene, methane, and a 64 mole-% ethylene / 36 % methane mixture, the writer s previously recommended gaseous surrogate fuel for HIFiRE scramjet tests. The HC vs. clean air part of the work is an extension of a May 2008 JANNAF paper that characterized surrogates for the HIFiRE project that should mimic the flameholding of reformed (thermally- or catalytically-cracked) endothermic JP-like fuels. The new FS data for 7 HCs vs. clean air are thus consolidated with the previously validated data, normalized to absolute (local) axial-input strain rates, and co-plotted on a dual kinetically dominated reactivity scale. Excellent agreement with the prior data is obtained for all 7 fuels. Detailed comparisons are also made with recently published (Univ. Va) numerical results for ethylene extinction. A 2009-revised ethylene kinetic model (Univ. Southern Cal) led to predicted limits within approx. 5 % (compared to 45 %, earlier) of this writer s 2008 (and present) ethylene FSs, and also with recent independent data (Univ. Va) obtained on a new OJB system. These +/- 5 % agreements, and a hoped-for "near-identically-performing" reduced kinetics model, would greatly enhance the capability for accurate numerical simulations of surrogate HC flameholding in scramjets. The measured air-contamination effects on normalized FS extinction limits are projected to assess ongoing Arc-Heater-induced "facility test effects" of NO production (e.g., 3 mole-%) and resultant oxygen depletion (from 21 to 19.5 %), for testing the "64/36" surrogate fuel in Langley s Arc-Heated Scramjet Test Facility for HIFiRE engine designs. The FS results show a generally small (< 4 %) "nitric oxide enhancement" effect, relative to clean air, for up to 3 % NO (freestream Mach number up to 7 in Arc Jet testing). However, a progressively large "oxygendeficiency weakening" effect develops. For 3 % NO, a net weakening of 26 % in FS is derived for the "64/36" fuel vs. air. The corresponding net weakening for pure ethylene is 20 %. A number of practical recommendations regarding facility test effects are offered

Comparing non-invasive surveying techniques for elusive, nocturnal mammals: a case study of the West European hedgehog (Erinaceus europaeus)

Monitoring changes in populations is fundamental for effective management. The West European hedgehog (Erinaceus europeaus) is of conservation concern in the UK because of recent substantial declines. Surveying hedgehogs is, however, problematic because of their nocturnal, cryptic behaviour. We compared the effectiveness of three methods (infra-red thermal camera, specialist search dog, spotlight) for detecting hedgehogs in three different habitats. Significantly more hedgehogs were detected, and at greater distance, using the camera and dog than the spotlight in amenity grassland and pasture; no hedgehogs were detected in woodland. Increasing ground cover reduced detection distances, with most detections (59.6%) associated with bare soil or mown grass; the dog was the only method that detected hedgehogs in vegetation taller than the target species’ height. The additional value of surveying with a detection dog is most likely to be realised in areas where badgers (Meles meles), an intra-guild predator, are and/or where sufficient ground cover is present; both would allow hedgehogs to forage further from refuge habitats such as hedgerows. Further consideration of the effectiveness of detection dogs for finding hedgehogs in nests, as well as developing techniques for monitoring this species in woodland, is warranted

Assessing wellbeing at school entry using the strengths and difficulties questionnaire: professional perspectives

&lt;p&gt;Background: Emotional and behavioural disorders in early childhood are related to poorer academic attainment and school engagement, and difficulties already evident at the point of starting school can affect a child’s later social and academic development. Successful transfer from pre-school settings to primary education is helped by communication between pre-school staff and primary school teachers. Typically, in Scotland, pre-school establishments prepare individual profiles of children before they start school around the age of five years, highlighting their strengths and development needs, for transfer to primary schools. There is, however, no consistent approach to the identification of potential social, emotional and behavioural problems. In 2010, in one local authority area in Scotland, the Strengths and Difficulties Questionnaire (SDQ) was introduced for children about to start school as a routine, structured, component of the transition process to help teachers plan support arrangements for classes and individual children. The SDQ assesses emotional, conduct, hyperactivity/ inattention and peer-relationship problems as well as pro-social behaviour. In order to be an effective means of communicating social and emotional functioning, the use of instruments such as the SDQ needs to be practicable. Finding out the views of pre-school education staff with experience of assessing children using the SDQ was, therefore, essential to establish its future utility.&lt;/p&gt; &lt;p&gt;Aim: The purpose of this study was to explore the views of pre-school education staff about assessing social and emotional wellbeing of children at school entry using the SDQ. The objectives were to examine the opinions of pre-school workers about completing the SDQ and to elicit their thoughts on the value of doing this and their perceptions of the usefulness of the information collected.&lt;/p&gt; &lt;p&gt;Method: Pre-school establishments were approached using a purposive sampling strategy in order to achieve a mix of local authority (n=14) and ‘partnership’ establishments (n=8) as well as different socio-economic areas. Semi-structured interviews (n=25) were conducted with pre-school head teachers (n=14) and child development officers (n=11) in order to explore the process of completing the SDQ along with perceptions of its value. The interviews were transcribed verbatim and analysed thematically.&lt;/p&gt; &lt;p&gt;Results: In general, staff in pre-school establishments viewed the use of the SDQ positively. It was seen as a chance to highlight the social and emotional development of children rather than just their academic or educational ability. Most felt that the SDQ had not identified anything they did not already know about a child. A minority, nevertheless, suggested that a previously unrecognised potential difficulty was brought to light, most commonly emotional problems. Completing the SDQ was felt to be relatively straightforward even though the staff felt under pressure from competing priorities. Concerns were, however, raised about the potential of labelling a child at an early stage of formal education.&lt;/p&gt; &lt;p&gt;Conclusion: The findings from this small scale study suggest that, from the point of view of pre-school education staff, it is feasible to assess children systematically for social and behavioural problems as part of the routine transition process at school entry.&lt;/p&gt

A randomised controlled trial of blood pressure self-monitoring in the management of hypertensive pregnancy. OPTIMUM-BP:A feasibility trial

Objective: To assess the feasibility of a blood pressure self-monitoring intervention for managing pregnancy hypertension. Study design: OPTIMUM-BP was an unmasked randomised controlled trial comparing a self-monitoring of blood pressure (SMBP) intervention versus usual care for the management of pregnancy hypertension. Women with chronic (CH) or gestational hypertension (GH) from 4 UK centres were randomised (2:1) intervention to control. Self-monitoring involved daily home blood pressure (BP) measurements, with recording via study diary or telemonitoring. Clinicians were invited to use the home readings in clinical and antihypertensive titration decisions. Main outcomes: The primary outcomes were recruitment, retention, adherence and persistence with the intervention. Results: Women from four UK centres were randomised: 158/222 (71%) of those approached agreed, comprising: 86 women with chronic hypertension (55 SMBP, 31 control) and 72 with gestational hypertension (49 SMBP, 23 control) of whom outcome data were available from 154 (97%) and were included in the analysis. The median (IQR) number of days with home BP readings per week were 5.5 (3.1–6.5) for those with chronic hypertension and 6.1 (4.5–6.7) with gestational hypertension. Participants persisted with the intervention for 80% or more of their time from enrolment until delivery in 86% (43/50) and 76% (38/49) of those with chronic and gestational hypertension respectively. Recorded clinic and study BPs were similar for both groups. Conclusions: This is the first randomised investigation of BP self-monitoring for the management of pregnancy hypertension and indicates that a large RCT would be feasible.</p

Celebrity abuse on Twitter: the impact of tweet valence, volume of abuse, and dark triad personality factors on victim blaming and perceptions of severity

Celebrities are increasingly utilizing social media platforms to establish their brand and interact with their fan base, but in doing so they often become the targets of online abuse. While such abusive acts are known to cause severe consequences in the general population little is known about how celebrity abuse is perceived by observers. This study investigated observers' impressions of the severity of online abuse on Twitter, the blame attributed to celebrities for the abuse they received, and the role of the dark triad of observers' personality factors (Machiavellianism, narcissism, and psychopathy) in these decisions. We manipulated celebrity tweet content (negative, neutral, positive) and the volume of abusive comments (high, low) the tweets received. Celebrities received more blame the more negative their initial tweet was, and incidents were perceived as least severe following a negative tweet with a high volume of abuse. Observer impressions were influenced by their dark triad personality factors. Following negative tweets, as observer narcissism increased, victim blame increased and perceived severity decreased. Following positive tweets, as observer psychopathy increased, perceived severity decreased. Results are discussed in the context of the Warranting Theory of online impression formation and the ramifications for celebrity social media use are explored

Crystal engineering urea organic acid hydrogen bonded networks with solvent inclusion properties

Eleven structurally similar materials based on hydrogen bonded networks of N-phenylurea and 5-nitroisophthalic acid have been engineered where nine have interesting solvent inclusion and guest release properties.</p

A photometric and spectroscopic study of NSVS 14256825: the second sdOB+dM eclipsing binary

We present an analysis of UBVR$_{\rm C}$I$_{\rm C}$JH photometry and phase-resolved optical spectroscopy of NSVS 14256825, an HW Vir type binary. The members of this class consist of a hot subdwarf and a main-sequence low-mass star in a close orbit ($P_{\rm orb} ~ 0.1$ d). Using the primary-eclipse timings, we refine the ephemeris for the system, which has an orbital period of 0.11037 d. From the spectroscopic data analysis, we derive the effective temperature, $T_1 = 40000 \pm 500$ K, the surface gravity, $\log g_1 = 5.50\pm0.05$, and the helium abundance, $n(\rm He)/n(\rm H)=0.003\pm0.001$, for the hot component. Simultaneously modelling the photometric and spectroscopic data using the Wilson-Devinney code, we obtain the geometrical and physical parameters of NSVS 14256825. Using the fitted orbital inclination and mass ratio (i = 82\fdg5\pm0\fdg3 and $q = M_2/M_1 = 0.260\pm0.012$, respectively), the components of the system have $M_1 = 0.419 \pm 0.070 M_{\odot}$, $R_1 = 0.188 \pm 0.010 R_{\odot}$, $M_2 = 0.109 \pm 0.023 M_{\odot}$, and $R_2 = 0.162 \pm 0.008 R_{\odot}$. From its spectral characteristics, the hot star is classified as an sdOB star.Comment: 8 pages, 7 figures, accepted for publication in MNRA

Language and social/emotional problems identified at a universal developmental assessment at 30 months

Non peer reviewedPublisher PD

NSVS06507557; a low-mass double-lined eclipsing binary

In this paper we present the results of a detailed spectroscopic and photometric analysis of the V=13$^m$.4 low-mass eclipsing binary NSVS 06507557 with an orbital period of 0.515 d. We obtained a series of mid-resolution spectra covering nearly entire orbit of the system. In addition we obtained simultaneous VRI broadband photometry using a small aperture telescope. From these spectroscopic and photometric data we have derived the system's orbital parameters and determined the fundamental stellar parameters of the two components. Our results indicate that NSVS 06507557 consists of a K9 and an M3 pre-main-sequence stars with masses of 0.66$\pm$0.09 \Msun and 0.28$\pm$0.05 \Msun and radii of 0.60$\pm$0.03 and 0.44$\pm$0.02 \Rsun, located at a distance of 111$\pm$9 pc. The radius of the less massive secondary component is larger than that of the zero-age main-sequnce star having the same mass. While the radius of the primary component is in agreement with ZAMS the secondary component appers to be larger by about 35 % with respect to its ZAMS counterpart. Night-to-night intrinsic light variations up to 0$^m$.2 have been observed. In addition, the H$_{\alpha}$, H$_{\beta}$ lines and the forbidden line of [O{\sc i}] are seen in emission. The Li{\sc i} 6708 \AA absorption line is seen in most of the spectra. These features are taken to be the signs of the classic T Tauri stars' characteristics. The parameters we derived are consistent with an age of about 20 Myr according to the stellar evolutionary models. The spectroscopic and photometric results are in agreement with those obtained by theoretical predictions.Comment: 21 pages, 9 figures. Accepted by MNRA

CoRoT photometry and high-resolution spectroscopy of the interacting eclipsing binary AU Mon

Analyses of very accurate CoRoT space photometry, past Johnson V photoelectric photometry and high-resolution \'echelle spectra led to the determination of improved and consistent fundamental stellar properties of both components of AU Mon. We derived new, accurate ephemerides for both the orbital motion (with a period of 11.113d) and the long-term, overall brightness variation (with a period of 416.9d) of this strongly interacting Be + G semi-detached binary. It is shown that this long-term variation must be due to attenuation of the total light by some variable circumbinary material. We derived the binary mass ratio $M_{\rm G}/M_{\rm B}$ = 0.17\p0.03 based on the assumption that the G-type secondary fills its Roche lobe and rotates synchronously. Using this value of the mass ratio as well as the radial velocities of the G-star, we obtained a consistent light curve model and improved estimates of the stellar masses, radii, luminosities and effective temperatures. We demonstrate that the observed lines of the B-type primary may not be of photospheric origin. We also discover rapid and periodic light changes visible in the high-quality residual CoRoT light curves. AU Mon is put into perspective by a comparison with known binaries exhibiting long-term cyclic light changes.Comment: Accepted for publication in MNRA