Bending of rectangular plates subject to non-uniform pressure distributions relevant to containment structures

Rectangular planform silos are often used where there is need for simple construction or space restrictions. The flexibility of the flat plate walls leads to a horizontal variation in wall pressure across each wall, with much reduced pressures at the mid‐side. There is a clear and systematic relationship between the wall flexural stiffness relative to the stiffness of the stored solid and the pressure pattern on the wall which is now well proven. Since the centre of each wall is subject to significantly reduced pressures, it may be expected that the bending moments in the wall will much lower, permitting the use of a thinner wall. In turn, the thinner wall is then more flexible and leads to a further redistribution of the pressures. This paper is the first to examine the structural consequences of these pressure changes. The horizontal variation of the wall pressure is well captured by a hyperbolic form, with much reduced mid‐side pressures and raised corner pressures, characterised by a single parameter “alpha” that determines the strength of this redistribution. This parameter α is naturally dependent on the relative wall and solid stiffness. In this study, the value of α is varied between the uniform pressure condition α = 0 and a high value (α=3). The highest values occur when a stiff solid is stored in a silo with very flexible walls. Wall plates of different aspect ratio are investigated representing conditions in a square or rectangular silo. The finite element predictions show that great savings can be made in the design of these structures by exploiting the reduced deflections and reduced stresses that arise when realistic patterns of pressure are adopted. The results presented here are suitable for transformation into design rules for the Eurocode standards EN 1993‐1‐7 [1] and EN 1993‐4‐1 [2]

Physical modelling applied to infrastructure development

The physical modelling conference series has served as a primary means of sharing practise and disseminating current research in experimental geotechnics. Each conference highlights the trends, techniques and direction of current research. This paper summarises contributions to the 9th International Conference on Physical Modelling in Geotechnics from researchers broadly in the field of infrastructure development. This themed paper aims to identify innovative approaches to geotechnical problems, advances in experimental techniques and equipment in order to address new research questions and future trends in infrastructure research that might feature more significantly in future conferences. Some reflection on past conference proceedings is included with the hope that the community appreciates the scale of our achievements since the first conference in the series

The centrality of the trinity. Exploring the significance for christians, catechists and deacons

‘The mystery of the Most Holy Trinity is the central mystery of Christian faith and life ... the source of all the other mysteries of faith, the light that enlightens them.’ This passage from the teaching of the Catechism of the Catholic Church (CCC) (234) on the profession of faith identifies the core principles and underlying recognition of Catholics regarding belief in a triune God – one God existent in three Persons: Father, Son and Holy Spirit. In addressing the people of Ephesus, St. Ignatius of Antioch (also known as Theophorus) said, faithful Christians were ‘being stones of the temple of the Father, prepared for the building of God the Father, and drawn up on high by the instrument of Jesus Christ, which is the cross, making use of the Holy Spirit as a rope, while your faith was the means by which you ascended, and your love the way which led up to God.’ (Ignatius of Antioch, 2014, loc. 4027.) St. Ignatius goes on to say, ‘the Holy Spirit does not speak His own things, but those of Christ, and that not from himself, but from the Lord’. The point St. Ignatius was making is that the three Persons of the triune God are integrally connected, and it is through the grace of the three-in-One that salvation is gained. Hence, the Trinity is the core of the Christian faith, but from the very beginning the faithful relied on metaphor to explain and help others understand how Three could be On

Dry Powder Intranasal Oxytocin for Treatment of Postpartum Hemorrhage in the Developing World

Complications related to pregnancy and child birth claim nearly 800 women’s lives each day. This tragedy is compounded by the fact that the vast majority of these deaths are preventable. However, ninety-nine percent of maternal deaths occur in the developing world where basic medical services and supplies are typically scarce. Postpartum hemorrhage (PPH; excessive bleeding after child birth), accounts for nearly 25% of maternal deaths globally, and is an especially acute concern in resource-scarce settings. The pharmacological treatment recommended for PPH by the World Health Organization, oxytocin, is incompatible with regions where reliable refrigeration is unavailable. Typically formulated as an aqueous solution for injection, oxytocin rapidly loses efficacy at room temperature via chemical degradation. In the present work, we explore the feasibility of adapting oxytocin from its standard injectable solution form to a dry powder formulation for intranasal administration. A preclinical evaluation reveals an impressive 12% bioavailability (relative to intramuscular injection) with sufficiently rapid onset for treatment of PPH. Moreover, in-vitro characterization confirmed good physical and chemical stability, offering hope that dry powder oxytocin formulations for intranasal delivery may be a viable option for treatment of PPH in the developing world

Rectangular steel silos: Finite element predictions of filling wall pressures

The pressures exerted on the walls of rectangular planform steel flexible-walled silos by several different stored granular bulk solids are investigated using a validated finite element model that has been used in several previous studies. These pressures and the state of stress in the bulk solid are explored for a range of silo geometries and stored bulk solids. The results show that the horizontal pressure distribution across a silo wall is generally not uniform. This demonstrates that widely used theories may be adequate for stiff concrete silos, are far from suited to flexible-walled steel silos, and the differences can be used to produce much lighter structures. These findings match previously published experimental and analytical results for square planform silos where much larger pressures develop in the corners. The present analyses show that rectangular silos differ from those of square section, in that the mean pressure and degree of pressure variation is different on the two walls. The mechanisms causing these changes are investigated. The results further demonstrate that relatively small changes in the properties of a stored solid can produce significant changes in the pressure magnitudes and patterns, and hence greatly influence the silo structural design. The paper concludes that existing design guidance is seriously deficient and leads to metal silos that are considerably more expensive than is necessary

A Rancièrian consideration of the formal and informal learning and knowledge of grassroots community activists

As inequality grows, with the gap between rich and poor widening, education is regularly proposed as a way to tackle this disparity and to offer people a way out of poverty. The more educated people are, the wealthier and happier they are expected to be. Education policies and practice aim to improve people and their lives in order to improve society, business and the economy. Societal problems tend to be seen as learning problems which individuals are expected to solve through their own learning. If individuals do not take action to gain qualifications, the disadvantages they face are considered justifiable. With the emphasis on formal education and qualifications, what we learn informally is not recognised and valued and nor, it seems, are the people who have learned most of what they know informally. This research explored the value of informal learning, alongside formal learning, in a context in which people work towards a particular goal. Community activism was identified as a suitable context. Using a Constructivist Grounded Theory approach, nine community activists from around Scotland were interviewed. This methodology, along with the work of Michel Foucault and Jacques Rancière, facilitated an investigation of the topic by encouraging an openness to what participants said in the interviews and also how they said it. Three research questions guided the generation and analysis of the data. These considered how people positioned themselves in relation to learning and knowledge, what they learned and the role of both formal and informal learning in bringing about change in communities. While it is not unusual to find Foucault employed in such research, it is less common for Rancière to provide an analytical lens. Doing so here has proved very productive in highlighting the need to perceive people, education and equality differently. If we are to solve the problem of inequality through education, we need to be able to see that problem differently. The problem is often presented as a gap in attainment. Using Rancière, we can conceive instead of a dividing line. On one side of the line is that which can be counted as knowledge and those who are considered to know and think. On the other, there is nonsense and those who do not know or think – those who are excluded and whose knowledge is discounted. While policy reform after policy reform has not succeeded in reducing the gap, work which seeks to breach the dividing line might have more success in working towards a more equal world. The examples from the participants in this study indicate how this might be achieved through claiming the right to speak and be heard