A high frequency boundary element method for scattering by a class of nonconvex obstacles

In this paper we propose and analyse a hybrid numerical-asymptotic boundary element method for the solution of problems of high frequency acoustic scattering by a class of sound-soft nonconvex polygons. The approximation space is enriched with carefully chosen oscillatory basis functions; these are selected via a study of the high frequency asymptotic behaviour of the solution. We demonstrate via a rigorous error analysis, supported by numerical examples, that to achieve any desired accuracy it is sufficient for the number of degrees of freedom to grow only in proportion to the logarithm of the frequency as the frequency increases, in contrast to the at least linear growth required by conventional methods. This appears to be the first such numerical analysis result for any problem of scattering by a nonconvex obstacle. Our analysis is based on new frequency-explicit bounds on the normal derivative of the solution on the boundary and on its analytic continuation into the complex plane.

'Hey little rich boy, take a good look at me': punk, class and British oi!

This article looks at the controversial music genre Oi! in relation to youth cultural identity in late 1970s and early 1980s Britain. By examining the six compilation albums released to promote Oi! as a distinct strand of punk, it seeks to challenge prevailing dismissals of the genre as inherently racist or bound to the politics of the far right. Rather, Oi! – like punk more generally – was a contested cultural form. It was, moreover, centred primarily on questions of class and locality. To this end, Oi! sought to realize the working-class rebellion of punk’s early aesthetic; to give substance to its street-level pretentions and offer a genuine ‘song from the streets’.

British working-class household composition, labour supply, and commercial leisure participation during the 1930s

The early twentieth century constituted the heyday of the ‘breadwinner–homemaker’ household, characterized by a high degree of intra-household functional specialization between paid and domestic work according to age, gender, and marital status. This article examines the links between formal workforce participation and access to resources for individualized discretionary spending in British working-class households during the late 1930s, via an analysis of household leisure expenditures. Leisure spending is particularly salient to intra-household resource allocation, as it constitutes one of the most highly prioritized areas of individualized expenditure, especially for young, single people. Using a database compiled from surviving returns to the Ministry of Labour's national 1937/8 working-class expenditure survey, we examine leisure participation rates for over 600 households, using a detailed set of commercial leisure activities together with other relevant variables. We find that the employment status of family members other than the male breadwinner was a key factor influencing their access to commercial leisure. Our analysis thus supports the view that the breadwinner–homemaker household was characterized by strong power imbalances that concentrated resources—especially for individualized expenditures—in the hands of those family members who engaged in paid labour.

Sunlit fractions on urban facets: impact of spatial resolution and approach

The extent of the surface area sunlit is critical for radiative energy exchanges and therefore for a wide range of applications that require urban land surface models (ULSM), ranging from human comfort to weather forecasting. Here a computational demanding shadow casting algorithm is used to assess the capability of a simple single-layer urban canopy model, which assumes an infinitely long rotating canyon (ILC), to reproduce sunlit areas on roof and roads over central London. Results indicate that the sunlit roads areas are well-represented but somewhat smaller using an ILC, while sunlit roofs areas are consistently larger, especially for dense urban areas. The largest deviations from real world sunlit areas are found for roofs during mornings and evenings. Indications that sunlit fractions on walls are overestimated using an ILC during mornings and evenings are found. The implications of these errors are dependent on the application targeted. For example, (independent of albedo) ULSMs used in numerical weather prediction applying ILC representation of the urban form will overestimate outgoing shortwave radiation from roofs due to the overestimation of sunlit fraction of the roofs. Complications of deriving height to width ratios from real world data are also discussed.

An operationally simple sonogashira reaction for an undergraduate organic chemistry laboratory class

An operationally simple, reliable, and cheap Sonogashira reaction suitable for an undergraduate laboratory class that can be completed within a day-long (8 h) laboratory session has been developed. Cross-coupling is carried out between 2-methyl-3-butyn-2-ol and various aryl iodides using catalytic amounts of bis-(triphenylphosphine)palladium(II) dichloride, with copper(I) iodide as a cocatalyst, in triethylamine at room temperature, so a range of products can be prepared within a single group and results compared. The coupling itself is usually complete within 1.5 h and is easily monitored by TLC, leaving up to 6 h for purification and characterization. Purification is by “mini flash column chromatography” through a plug of silica encased in the barrel of a plastic syringe, so the procedure is amenable to large class sizes.

Home in British working-class fiction

Offering new readings of working-class writing that focus on the home as a key emotional and material site in writing by working-class authors from the Edwardian period through to the mid-1990s. With close readings of The Ragged Trousered Philanthropists, works by D. H. Lawrence, Ethel Carnie Holdsworth, Ellen Wilkinson, Lewis Grassic Gibbon, Walter Brierley, Alan Sillitoe, John Braine, Nell Dunn, Sam Selvon, Sid Chaplin, Buchi Emecheta, Pat Barker, Jeanette Winterson, James Kelman and many others. The book demonstrates the importance of ideas of home and its narrative representation to the making and expression of class feeling and identity.

Demonstrating distinction at ‘the lowest edge of the black-coated class’: the family expenditures of Edwardian railway clerks

Families at the bottom end of the Edwardian white-collar income spectrum demonstrated middle-class status through observable consumption, at the cost of squeezing other expenditures, including ‘necessities’. This had negative economic impacts, lowering living standards due to inefficiently high budget shares for positional goods. Drawing on the work of Pierre Bourdieu, we examine how railway clerks sought to demonstrate ‘distinction’ from manual workers through certain conspicuous expenditures and how this strategy was progressively undermined by falling real incomes over the Edwardian period.

Distribution of lipids in the grain of wheat (cv Hereward) determined by lipidomic analysis of milling and pearling fractions

Lipidomic analyses of milling and pearling fractions from wheat grain were carried out to determine differences in composition which could relate to the spatial distribution of lipids in the grain. Free fatty acids and triacylglycerols were major components in all fractions, but the relative contents of polar lipids varied, particularly lysophosphatidyl choline and digalactosyldiglyceride, which were enriched in flour fractions. By contrast, minor phospholipids were enriched in bran and offal fractions. The most abundant fatty acids in the analysed acyl lipids were C16:0 and C18:2 and their combinations, including C36:4 and C34:2. Phospholipids and galactolipids have been reported to have beneficial properties for bread making, while free fatty acids and triacylglycerols are considered detrimental. The subtle differences in the compositions of fractions determined in the present study could therefore underpin the production of flour fractions with optimised compositions for different end uses.

Perfective marking in L2 Mandarin: agreement with inherent lexical aspect or the derived Sentential Aspectual class?

This study evaluates the differing claims of the Aspect Hypothesis (Anderson & Shirai 1996) and the Sentential Aspect Hypothesis (Sharma & Deo 2009) for perfective marking by L1 English learners of Mandarin. The AH predicts a narrow focus on inherent lexical aspect (the verb and predicate) in determining the use of the perfective marker le, whilst the SAH suggests that – subject to L1 influence – perfective marking agrees with the final derived aspectual class of the sentence. To test these claims data were collected using a controlled le-insertion task, combined with oral corpus data. The results show that learners’ perfective marking patterns with the sentential aspectual class and not inherent lexical aspect (where these differ), and that overall the sentential aspectual class better predicts learners’ assignment of perfective marking than lexical aspect.

A new calibrated sunspot group series since 1749: statistics of active day fractions

Although the sunspot-number series have existed since the mid-19th century, they are still the subject of intense debate, with the largest uncertainty being related to the "calibration" of the visual acuity of individual observers in the past. Daisy-chain regression methods are applied to inter-calibrate the observers which may lead to significant bias and error accumulation. Here we present a novel method to calibrate the visual acuity of the key observers to the reference data set of Royal Greenwich Observatory sunspot groups for the period 1900-1976, using the statistics of the active-day fraction. For each observer we independently evaluate their observational thresholds [S_S] defined such that the observer is assumed to miss all of the groups with an area smaller than S_S and report all the groups larger than S_S. Next, using a Monte-Carlo method we construct, from the reference data set, a correction matrix for each observer. The correction matrices are significantly non-linear and cannot be approximated by a linear regression or proportionality. We emphasize that corrections based on a linear proportionality between annually averaged data lead to serious biases and distortions of the data. The correction matrices are applied to the original sunspot group records for each day, and finally the composite corrected series is produced for the period since 1748. The corrected series displays secular minima around 1800 (Dalton minimum) and 1900 (Gleissberg minimum), as well as the Modern grand maximum of activity in the second half of the 20th century. The uniqueness of the grand maximum is confirmed for the last 250 years. It is shown that the adoption of a linear relationship between the data of Wolf and Wolfer results in grossly inflated group numbers in the 18th and 19th centuries in some reconstructions.

Authenticity and performance of class in British factual TV series

The chapter characterises British ‘Reality TV’ as a hybrid of factual and fictional television genres, as signaled by the more accurate genre designation ‘structured reality’ television. From the 1990s onwards, in order to develop programmes that are attractive to audiences and inexpensive to produce, programme makers have focused on hybrids of dramatic and documentary modes. This chapter argues that many recent Reality TV programmes privilege soap opera’s emphasis on character, storyline and performance. This affects the ways that class authenticity is understood, undermining factual programmes’ usual claim to legitimacy based on reference to a pre-existing reality, and transforming hierarchies that separate highly-valued from low-valued types of programme.