Subgrade geology beneath railways in Manchester

It is not sufficient to identify fine-grained soils, only, as locations for potential subgrade problems as could be done using a traditional 2D geological map. More information is required about the geological structure, lithological variability, mineralogy, moisture content and geotechnical properties of the soil, much of which can be supplied by modern 3D geospatial databases. These databases can be interrogated at key depths to show the wide variability of geological materials and conditions beneath the ground surface. Geological outcrop and thickness of bedrock an superficial deposits (soils), plus the permeability and water table level are predicted from the Manchester geospatial model that is based on 6500 borehole records. Geological sections along railway routes are modelled and the locations of problem soils such as alluvium, till and glaciolacustrine deposits at outcrop and shallow subcrop are identified. Spatial attribution of geotechnical data and simple methods to recast sections in engineering geological terms are demonstrated

Study of the radiation hardness of CsI(Tl) scintillation crystals

This paper is devoted to the study of a degradation of CsI(Tl)crystals scintillation characteristics under irradiation with gamma-quanta at the uniformly distributed absorbed dose up to 3700 rad. The sample set consisted of 25 crystals of 30 cm long having a truncated pyramid shape and 30 rectangular crystals of the same length. A large difference in the light output deterioration caused by the radiation was observed for the samples of the same shape. A substantial dependence of the average light output loss from the sample shape is seen as well. On the other hand, the crystals from the same ingot behave very similarly under irradiation

Energy radiation of moving cracks

The energy radiated by moving cracks in a discrete background is analyzed. The energy flow through a given surface is expressed in terms of a generalized Poynting vector. The velocity of the crack is determined by the radiation by the crack tip. The radiation becomes more isotropic as the crack velocity approaches the instability threshold.Comment: 7 pages, embedded figure

Lubricating Bacteria Model for Branching growth of Bacterial Colonies

Various bacterial strains (e.g. strains belonging to the genera Bacillus, Paenibacillus, Serratia and Salmonella) exhibit colonial branching patterns during growth on poor semi-solid substrates. These patterns reflect the bacterial cooperative self-organization. Central part of the cooperation is the collective formation of lubricant on top of the agar which enables the bacteria to swim. Hence it provides the colony means to advance towards the food. One method of modeling the colonial development is via coupled reaction-diffusion equations which describe the time evolution of the bacterial density and the concentrations of the relevant chemical fields. This idea has been pursued by a number of groups. Here we present an additional model which specifically includes an evolution equation for the lubricant excreted by the bacteria. We show that when the diffusion of the fluid is governed by nonlinear diffusion coefficient branching patterns evolves. We study the effect of the rates of emission and decomposition of the lubricant fluid on the observed patterns. The results are compared with experimental observations. We also include fields of chemotactic agents and food chemotaxis and conclude that these features are needed in order to explain the observations.Comment: 1 latex file, 16 jpeg files, submitted to Phys. Rev.

Women’s mental health during pregnancy: A participatory qualitative study

Background/objectives: British public health and academic policy and guidance promotes service user involvement in health care and research, however collaborative research remains underrepresented in literature relating to pregnant women’s mental health. The aim of this participatory research was to explore mothers’ and professionals’ perspectives on the factors that influence pregnant women’s mental health. Method: This qualitative research was undertaken in England with the involvement of three community members who had firsthand experience of mental health problems during pregnancy. All members of the team were involved in study design, recruitment, data generation and different stages of thematic analysis. Data were transcribed for individual and group discussions with 17 women who self-identified as experiencing mental health problems during pregnancy and 15 professionals who work with this group. Means of establishing trustworthiness included triangulation, researcher reflexivity, peer debriefing and comprehensive data analysis. Findings: Significant areas of commonality were identified between mothers’ and professionals’ perspectives on factors that undermine women’s mental health during pregnancy and what is needed to support women’s mental health. Analysis of data is provided with particular reference to contexts of relational, systemic and ecological conditions in women’s lives. Conclusions: Women’s mental health is predominantly undermined or supported by relational, experiential and material factors. The local context of socio-economic deprivation is a significant influence on women’s mental health and service requirements

Clastic Polygonal Networks Around Lyot Crater, Mars: Possible Formation Mechanisms From Morphometric Analysis

Polygonal networks of patterned ground are a common feature in cold-climate environments. They can form through the thermal contraction of ice-cemented sediment (i.e. formed from fractures), or the freezing and thawing of ground ice (i.e. formed by patterns of clasts, or ground deformation). The characteristics of these landforms provide information about environmental conditions. Analogous polygonal forms have been observed on Mars leading to inferences about environmental conditions. We have identified clastic polygonal features located around Lyot crater, Mars (50°N, 30°E). These polygons are unusually large (> 100 m diameter) compared to terrestrial clastic polygons, and contain very large clasts, some of which are up to 15 metres in diameter. The polygons are distributed in a wide arc around the eastern side of Lyot crater, at a consistent distance from the crater rim. Using high-resolution imaging data, we digitised these features to extract morphological information. These data are compared to existing terrestrial and Martian polygon data to look for similarities and differences and to inform hypotheses concerning possible formation mechanisms. Our results show the clastic polygons do not have any morphometric features that indicate they are similar to terrestrial sorted, clastic polygons formed by freeze-thaw processes. They are too large, do not show the expected variation in form with slope, and have clasts that do not scale in size with polygon diameter. However, the clastic networks are similar in network morphology to thermal contraction cracks, and there is a potential direct Martian analogue in a sub-type of thermal contraction polygons located in Utopia Planitia. Based upon our observations, we reject the hypothesis that polygons located around Lyot formed as freeze-thaw polygons and instead an alternative mechanism is put forward: they result from the infilling of earlier thermal contraction cracks by wind-blown material, which then became compressed and/or cemented resulting in a resistant fill. Erosion then leads to preservation of these polygons in positive relief, while later weathering results in the fracturing of the fill material to form angular clasts. These results suggest that there was an extensive area of ice-rich terrain, the extent of which is linked to ejecta from Lyot crater

Propagation and Structure of Planar Streamer Fronts

Streamers often constitute the first stage of dielectric breakdown in strong electric fields: a nonlinear ionization wave transforms a non-ionized medium into a weakly ionized nonequilibrium plasma. New understanding of this old phenomenon can be gained through modern concepts of (interfacial) pattern formation. As a first step towards an effective interface description, we determine the front width, solve the selection problem for planar fronts and calculate their properties. Our results are in good agreement with many features of recent three-dimensional numerical simulations. In the present long paper, you find the physics of the model and the interfacial approach further explained. As a first ingredient of this approach, we here analyze planar fronts, their profile and velocity. We encounter a selection problem, recall some knowledge about such problems and apply it to planar streamer fronts. We make analytical predictions on the selected front profile and velocity and confirm them numerically. (abbreviated abstract)Comment: 23 pages, revtex, 14 ps file

Interrogating trans and sexual identities through the conceptual lens of translocational positionality

This article explores the confluence of trans identity and sexuality drawing on the concept of translocational positionality. In this discussion, a broad spectrum of gendered positionalities incorporates trans identity which, in turn, acknowledges normative male and female identities as well as non-binary ones. It is also recognised, however, that trans identity overlaps with other positionalities (pertaining to sexuality, for example) to shape social location. In seeking to understand subject positions, a translocational lens acknowledges the contextuality and temporality of social categories to offer an analysis which recognises the overlaps and differentials of co-existing positionalities. This approach enables an analysis which explores how macro, or structural, contexts shape agency (at the micro-level) and also how both are mediated by trans people's multiple and shifting positionalities. In this framing, positionality represents a meso layer between structure and agency. Four case studies are presented using data from a qualitative study which explored trans people's experiences of family, intimacy and domestic abuse. We offer an original contribution to the emerging knowledge-base on trans sexuality by presenting data from four case studies. We do so whilst innovatively applying the conceptual lens of translocational positionality to an analysis which considers macro, meso and micro levels of influence

Access to infertility consultations: what women tell us about it?

The main objective of the present paper is to evaluate the perception of women concerning the barriers and access to infertility consultations. Socio cultural and economic access to infertility consultations is detached and three municipalities of the northwest of Portugal were chosen as an example of a peripheral country. A quantitative/qualitative study was done with 60 women. Three dimensions were evaluated: geographic and structural and functional access; economic access; and sociocultural access. The main barriers were mainly identified in the last two dimensions. The economic access was the less well evaluated by women being the cost of treatment (medication, and concentration of costs in a short period) difficult to bear. This can justify a greater involvement of the Portuguese Government, by developing policies for the reimbursement of part of the costs. Also, some changes in structural and functional access must be done with special regard to the separation of the infertility consultations from the reproductive medicine section. The setting of the teams, with a follow-up by the same team of health professionals is also needed