A review of urban roughness sublayer turbulence

It is becoming increasingly important that we can understand and model flow processes in urban areas. Applications such as weather forecasting, air quality and sustainable urban development rely on accurate modelling of the interface between an urban surface and the atmosphere above. This review gives an overview of current understanding of turbulence generated by an urban surface up to a few building heights, the layer called the roughness sublayer (RSL). High quality datasets are also identified which can be used in the development of suitable parameterisations of the urban RSL. Datasets derived from physical and numerical modelling, and full-scale observations in urban areas now exist across a range of urban-type morphologies (e.g. street canyons, cubes, idealised and realistic building layouts). Results show that the urban RSL depth falls within 2 – 5 times mean building height and is not easily related to morphology. Systematic perturbations away from uniform layouts (e.g. varying building heights) have a significant impact on RSL structure and depth. Considerable fetch is required to develop an overlying inertial sublayer, where turbulence is more homogeneous, and some authors have suggested that the “patchiness” of urban areas may prevent inertial sublayers from developing at all. Turbulence statistics suggest similarities between vegetation and urban canopies but key differences are emerging. There is no consensus as to suitable scaling variables, e.g. friction velocity above canopy vs. square root of maximum Reynolds stress, mean vs. maximum building height. The review includes a summary of existing modelling practices and highlights research priorities

Is modern marriage a bargain? Exploring perceptions of pre-nuptial agreements in England and Wales

types: ArticleAuthors' pre-print version archived with permission of the publisher. Final version published by Jordan; available at http://www.jordanpublishing.co.uk/online-services/family-lawDrawing on data from a recent national and follow-up study exploring attitudes towards binding pre-nuptial agreements at a time when the Law Commission was considering law reform, this article considers what might be gained and lost in family law terms by their introduction. Looking at the tensions between providing autonomy to agree arrangements at the outset of a marriage and achieving fairness between the parties at the point of divorce, questions were framed in the study to consider views on the socio-legal and psychological issues surrounding a move towards making pre-nuptial agreements binding. In particular, it explored whether we are ready culturally to use pre-nuptial agreements and any perceived limit to their acceptability. In addition, were there situations where pre-nuptial agreements were considered more or less appropriate for those entering marriage? How might they affect the commitment involved in marriage? More generally, in the light of the study’s findings, the article examines the implications of a legal and moral shift away from a paternalistic court redistribution of assets at the point of divorce towards an approach based on enforcement of a pre-maritally determined private contract, and concludes by considering what sort of a bargain it would be acceptable for modern marriage to become

Legal assumptions, cohabitants' talk and the rocky road to reform

types: ArticleAuthors' pre-print version archived with permission of the publisher. Final version published by Jordan; available at http://www.jordanpublishing.co.uk/online-services/family-lawThis article assesses recent proposals for the reform of cohabitation law by drawing on two interdisciplinary empirical studies. The first, sponsored by the Ministry of Justice included a survey (n=102) of people who had accessed the ‘Living Together Campaign’ website, investigating legal awareness, attitudes to cohabitation law and financial practices. The second, funded by the Nuffield Foundation, included a nationally representative survey (n=3197) investigating attitudes towards marriage, cohabitation and their legal and financial consequences. Each survey was followed up with semi-structured interviews which explored financial practices, processes of decision-making, understandings of commitment, awareness of and attitudes to current cohabitation law and possible law reform. In the analysis, we considered cohabitants’ practices alongside attitudes to their legal position and the links between finances, commitment and different ‘types’ of cohabitation were considered alongside demographic differences in order to explore the legal needs of diverse groups of cohabitants. We concluded that cohabitants in both projects fitted a typology comprising: Ideologues, Romantics, Pragmatists and Uneven couples and we considered the current proposals for legal reform in the light of this typology

Neutron Shielding Optimization Studies

The IsoDAR sterile-neutrino search calls for a high neutron flux from a 60 MeV proton beam striking a beryllium target, that flood a sleeve of highly-enriched 7Li, the beta-decay of the resulting 8Li giving the desired neutrinos for the veryshort-baseline experiment. The target is placed very close to an existing large neutrino detector; all such existing or planned detectors are deep underground, in low-background environments. It is necessary to design a shielding enclosure to prevent neutrons from causing unacceptable activation of the environment. GEANT4 is being used to study neutron attenuation, and optimising the layers of shielding material to minimize thickness. Materials being studied include iron and two new types of concrete developed by Jefferson Laboratory, one very light with shredded plastic aggregate, the other with high quantities of boron. Initial studies indicate that a total shielding thickness of 1.5 meters produces the required attenuation factor, further studies may allow decrease in thickness. Minimising it will reduce the amount of cavity excavation needed to house the target system in confined underground spaces

The Living Together Campaign - An investigation of its impact on legally aware cohabitants

Research Report to the Ministry of Justice, UK.This is a summary of the findings of a short study carried out between January and September 2006 into the behaviour and attitudes of a group of ‘legally aware’ cohabitants/former cohabitants and intending cohabitants who had accessed The Living Together Campaign (LTC)’s website on the legal position of cohabiting couples - http://www.advicenow.org.uk/livingtogether. ‘Legally aware’ cohabitants are defined here as those cohabitants who do not believe in the ‘common law marriage myth’ and thus are aware by having accessed the LTC website or by prior knowledge that they do not have the same rights as married couples.Ministry of Justice, UK

Observations of the morning development of the urban boundary layer over London, UK, taken during the ACTUAL project

The study of the boundary layer can be most difficult when it is in transition and forced by a complex surface, such as an urban area. Here, a novel combination of ground-based remote sensing and in situ instrumentation in central London, UK, is deployed, aiming to capture the full evolution of the urban boundary layer (UBL) from night-time until the fully-developed convective phase. In contrast with the night-time stable boundary layer observed over rural areas, the night-time UBL is weakly convective. Therefore, a new approach for the detection of the morning-transition and rapid-growth phases is introduced, based on the sharp, quasi-linear increase of the mixing height. The urban morning-transition phase varied in duration between 0.5 and 4 h and the growth rate of the mixing layer during the rapid-growth phase had a strong positive relationship with the convective velocity scale, and a weaker, negative relationship with wind speed. Wind shear was found to be higher during the night-time and morning-transition phases than the rapid-growth phase and the shear production of turbulent kinetic energy near the mixing-layer top was around six times larger than surface shear production in summer, and around 1.5 times larger in winter. In summer under low winds, low-level jets dominated the UBL, and shear production was greater than buoyant production during the night-time and the morning-transition phase near the mixing-layer top. Within the rapid-growth phase, buoyant production dominated at the surface, but shear production dominated in the upper half of the UBL. These results imply that regional flows such as low-level jets play an important role alongside surface forcing in determining UBL structure and growth

Nurses’ contributions to the resolution of ethical dilemmas in practice

Background: Complex and expensive treatment options have increased the frequency and emphasis of ethical decision making in healthcare. In order to meet these challenges effectively we need to identify how nurses contribute the resolution of these dilemmas. Aims: To identify the values, beliefs and contextual influences that inform decision making. To identify the contribution made by nurses in achieving the resolution of ethical dilemmas in practice. Design: An interpretive exploratory study was undertaken, eleven registered acute care nurses, working in a district general hospital in England were interviewed, using semi-structured interviews. In-depth content analysis of the data was undertaken via NVivo coding and thematic identification. Participants and context: Participants were interviewed about their contribution to the resolution of ethical dilemmas within the context of working in an acute hospital ward. Participants were recruited from all settings working with patients of any age and any diagnosis. Ethical considerations: Ethical approval was obtained from local the National Research Ethics Committee Findings: Four major themes emerged: ‘Best for the patient’, ‘Accountability’, ‘collaboration and conflict’ and ‘concern for others’. Moral distress was also evident in the literature and findings, with moral dissonance recognised and articulated by more experienced nurses. The relatively small, single site sample may not account for the effects of organisational culture on the results; the findings suggested that professional relationships were key to resolving ethical dilemmas. Discussion Nurses use their moral reasoning based on their beliefs and values when faced with ethical dilemmas. Subsequent actions are mediated though ethical decision making frames of reference including deontology, consequentialism, the ethics of care and virtue ethics. Nurses use these in contributing to the resolution of these dilemmas. Nurses require the skills to develop and maintain professional relationships for addressing ethical dilemmas and to engage with political and organisational macro and micro decision making. Conclusion: Nurses’ professional relationships are central to nurses’ contributions to the resolution of ethical dilemma

Radar studies of the vertical distribution of insects migrating over southern Britain: the influence of temperature inversions on nocturnal layer concentrations

Insects migrating over two sites in southern UK (Malvern in Worcestershire, and Harpenden in Hertfordshire) have been monitored continuously with nutating vertical-looking radars (VLRs) equipped with powerful control and analysis software. These observations make possible, for the first time, a systematic investigation of the vertical distribution of insect aerial density in the atmosphere, over temporal scales ranging from the short (instantaneous vertical profiles updated every 15 min) to the very long (profiles aggregated over whole seasons or even years). In the present paper, an outline is given of some general features of insect stratification as revealed by the radars, followed by a description of occasions during warm nights in the summer months when intense insect layers developed. Some of these nocturnal layers were due to the insects flying preferentially at the top of strong surface temperature inversions, and in other cases, layering was associated with higher-altitude temperature maxima, such as those due to subsidence inversions. The layers were formed from insects of a great variety of sizes, but peaks in the mass distributions pointed to a preponderance of medium-sized noctuid moths on certain occasions