Effect of serviceability limits on optimal design of steel portal frames

The design of hot-rolled steel portal frames can be sensitive to serviceability deflection limits. In such cases, in order to reduce frame deflections, practitioners increase the size of the eaves haunch and / or the sizes of the steel sections used for the column and rafter members of the frame. This paper investigates the effect of such deflection limits using a real-coded niching genetic algorithm (RC-NGA) that optimizes frame weight, taking into account both ultimate as well as serviceability limit states. The results show that the proposed GA is efficient and reliable. Two different sets of serviceability deflection limits are then considered: deflection limits recommended by the Steel Construction Institute (SCI), which is based on control of differential deflections, and other deflection limits based on suggestions by industry. Parametric studies are carried out on frames with spans ranging between 15 m to 50 m and column heights between 5 m to 10 m. It is demonstrated that for a 50 m span frame, use of the SCI recommended deflection limits can lead to frame weights that are around twice as heavy as compared to designs without these limits.

From Francis Hutcheson to James McCosh: Irish Presbyterians and Defining the Scottish Philosophy in the Nineteenth Century

This article examines the disputes amongst Irish Presbyterians about the teaching of moral philosophy by Professor John Ferrie in the college department of the Royal Belfast Academical Institution in the early nineteenth century and the substantive philosophical and theological issues that were raised. These issues have largely been ignored by Irish historians, but a discussion of them is of general relevance to historians of ideas as they illuminate a series of broader questions about the definition and development of Scottish philosophy. These are represented in the move from two philosophers who had strong connections with Irish Presbyterianism—Francis Hutcheson, the early eighteenth-century moral sense philosopher and theological moderate from County Down, and James McCosh, nineteenth-century exponent of modified Common Sense philosophy at Queen's College Belfast and a committed evangelical. In particular, this article addresses three important themes—the definition and character of ‘the Scottish philosophy’, the relationship between evangelicalism and Common Sense philosophy, and the process of development and adaptation that occurred in eighteenth-century Scottish thought during the first half of the nineteenth century.

Optimal design of cold-formed steel portal frames for stressed-skin action using genetic algorithm

This paper describes a stressed-skin diaphragm approach to the optimal design of the internal frame of a cold-formed steel portal framing system, in conjunction with the effect of semi-rigid joints. Both ultimate and serviceability limit states are considered. Wind load combinations are included. The designs are optimized using a real-coded niching genetic algorithm, in which both discrete and continuous decision variables are processed. For a building with two internal frames, it is shown that the material cost of the internal frame can be reduced by as much as 53%, compared with a design that ignores stressed-skin action.

Happy hour followed by hangover: financing the UK brewery industry, 1880-1913

In the last 15 years of the nineteenth century c.300 British brewers incorporated and floated securities on the stock market. Subsequently, in the 1900s, the industry suffered a long-lived hangover. In this paper, we establish the stylised facts of this transformation and estimate the gains enjoyed by brewery investors during the boom as well as the losses suffered by investors during the bust of the 1900s. However, not all brewery equity shares suffered alike. We find that post-1900 performance correlates positively with capital-market discipline and good corporate governance and negatively with family control, but does not correlate with indebtedness.

Large scale test of a novel back-pass non-perforated unglazed solar air collector

This paper describes large scale tests conducted on a novel unglazed solar air collector system. The proposed system, referred to as a back-pass solar collector (BPSC), has on-site installation and aesthetic advantages over conventional unglazed transpired solar collectors (UTSC) as it is fully integrated within a standard insulated wall panel. This paper presents the results obtained from monitoring a BPSC wall panel over one year. Measurements of temperature, wind velocity and solar irradiance were taken at multiple air mass flow rates. It is shown that the length of the collector cavities has a direct impact on the efficiency of the system. It is also shown that beyond a height-to-flow ratio of 0.023m/m³/hr/m², no additional heat output is obtained by increasing the collector height for the experimental setup in this study, but these numbers would obviously be different if the experimental setup or test environment (e.g. location and climate) change. An equation for predicting the temperature rise of the BPSC is proposed.

Control of wild rubber extraction in the forests of northeast India, 1850-1880

This paper uses the history of rubber extraction to explore competing attempts to control the forest environments of Assam and beyond in the second half of the nineteenth century. Forest communities faced rival efforts at environmental control from both European and Indian traders, as well as from various centres of authority within the Raj. Government attempts to regulate rubber collection were undermined by the weak authority of the Raj in these regions, leading to widespread smuggling. Partly in response to the disruptive influence of rubber traders on the frontier, the Raj began to restrict the presence of outsiders in tribal regions, which came to be understood as distinct areas outside British control. When rubber yields from the forests nearest the Brahmaputra fell in the wake of intensive exploitation, India's scientific foresters demanded and from 1870 obtained the ability to regulate the Assamese forests, blaming indigenous rubber tapping strategies for the declining yields and arguing that Indian rubber could be ‘equal [to] if not better' than Amazonian rubber if only tappers would change their practices. The knowledge of the scientific foresters was fundamentally flawed, however, and their efforts to establish a new type of tapping practice failed. By 1880, the government had largely abandoned attempts to regulate wild Indian rubber, though wild sources continued to dominate the supply of global rubber until after 1910.

Calvinist Absolutism: Archbishop James Ussher and Royal Power

Archbishop James Ussher's manuscript notebooks allow us to observe the making of a Calvinist absolutist and to orientate the archbishop's beliefs about royal power within European Reformed thought as a whole. By 1643, Ussher was preaching a polished and complete theory of absolute royal power, and it is possible to track the development of this political theory forward from his undergraduate days in the 1590s. Throughout his life Ussher engaged anxiously with Reformed theologians abroad, who generally favored limited rather than absolute monarchy. Nevertheless, Ussher shared with these Reformed colleagues both an antipathy to aspects of Aristotelian politics and a commitment to the divine institution of royal power. Finally, despite Ussher's hostility to Laudian innovations in the Irish Church, his heartfelt political beliefs made him a firm supporter of Stuart absolutism throughout the Three Kingdoms.

Essays on James Clarence Mangan: The Man in the Cloak

This volume explores the extraordinary literary achievement of James Clarence Mangan (1803-1849), increasingly recognised as one of the most important Irish writers of the nineteenth century and a crucial influence on later writers such as W.B. Yeats and James Joyce. It is the first collection of essays to focus on Mangan, and features articles by leading scholars in the field (including Jacques Chuto and David Lloyd) as well as contributions from acclaimed contemporary writers, Paul Muldoon and Ciaran Carson. The collection expands existing fields of debate--translation, the supernatural, intertextuality, nationalism, romanticism-- and introduces new ones: Mangan's afterlife in the English literary canon, cosmopolitanism and Weltliteratur, antiquity and futurity, nineteenth-century spiritualism and magical thinking. 'The man in the cloak', one of Mangan's favourite pseudonyms, is still a a resonant soubriquet for a writer who has eluded sustained critical attention, and this volumes restores him to his proper place in European and British, as well as Irish literary history.