Assessing initial embodied energy in UK non-domestic construction projects

There is an increasing need to reduce energy consumption to tackle the adverse effects of climate change. The UK government has established numerous directives and policies to encourage carbon dioxide (CO2) emission and energy reduction within the non-domestic sector. However these measures are primarily focused towards reducing operational energy (i.e. energy used during building occupier activity), largely overlooking initial embodied energy. The trend towards reduced operational energy consumption due to energy efficient design is leading initial embodied energy to become a more significant part of project life cycle energy. Initial embodied energy relates to the energy use during the material, transportation and construction phases up to project practical completion, which is of keen interest to contractors due to their significant role in project procurement and delivery. Opportunities to address project life cycle energy are typically identified through a Life Cycle Assessment (LCA). However at present there is little validated data, no coherent method for data capture and limited incentive for project stakeholders to address initial embodied energy consumption. In response, this research project presents a contractor s practical approach towards assessing initial embodied energy consumption within UK non-domestic construction projects. An action research methodological approach enabled the assessment and potential reduction of initial embodied energy to be explored within a large principal contractor through five research cycles which included diagnosing and action planning, action taking, evaluating and specified learning. A comprehensive framework is designed to highlight the significance of initial embodied energy consumption relative to specific construction packages, activities and sub-contractors. This framework is then explored within three UK non-domestic construction projects (i.e. two industrial warehouses and one commercial office). Capturing information from live projects enables practical challenges and opportunities inherent when addressing initial embodied energy consumption to be identified. A series of contractor current practices are reviewed, and subsequently improved, to enhance their compliance with the framework requirements. The findings emphasise the importance of material phase impacts, especially construction packages which primarily contain steel and concrete-based materials (i.e. ground and upper floor, external slab and frame). The importance of project type, site area, building lifespan and waste consumption are also recognised to reduce initial embodied energy consumption. The framework provides a practical approach for initial embodied energy assessment which can readily be adopted to help highlight further opportunities to reduce energy consumption. The research project concludes by presenting a number of recommendations for consideration by the construction industry and associated stakeholders, along with requirements for future research

Some Applications of Generalized Beam Theory

Generalised Beam Theory (GBT) has been developed by Professor R Schardt and his colleagues at the University of Darmstadt in Germany. The definitive reference at the present time is a recent German text(1) which describes the first-order theory. For the analysis of cold-formed sections, second-order theory may be required and this is less well documented. This paper will attempt to describe the principles involved and illustrate them by means of some practical examples. GBT unifies the conventional theories for the analysis of prismatic thin-walled structural members within a consistent notation. It then extends them into new territory. Conventional beam theory identifies four fundamental modes of deformation, namely extension, bending about two principal axes and torsion. These may be referred to as the rigid-body modes because they do not involve any distortion of the cross-section. Higher-order modes also exist but these involve cross-section distortion together with transverse bending. In first-order theory, all modes are orthogonal. This means that they are uncoupled and can be considered separately before their effects are combined. In second-order theory, the modes may become coupled but their orthogonal nature ensures that the coupling is minimised so that important results can often be obtained by a trivial calculation involving a single mode. GBT is a big subject with many ramifications and a full treatment is not possible within the confines of a single paper. No attempt will, therefore, be made to derive the basic equations and attention will be confined to explanation and application

XPS and STM studies of the oxidation of hydrogen chloride at Cu(100) surfaces

The dissociative chemisorption of HCl on clean and oxidized Cu(100) surfaces has been investigated using x-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM). Whereas the dissociation of HCl at the clean surface is limited to the formation of a (√ 2 × √ 2)-R45° Cl(a) monolayer, the presence of surface oxygen removes this barrier, leading to chlorine coverages up to twice that obtained at the clean surface. Additional features in the STM images that appear at these coverages are tentatively assigned to the nucleation of CuCl islands. The rate of reaction of the HCl was slightly higher on the oxidized surface but unaffected by the initial oxygen concentration or the availability of clean copper sites. Of the two distinct domains of adsorbed oxygen identified at room temperature on the Cu(100) surfaces, the (√ 2 × √ 2)-R45° structure reacts slightly faster with HCl than the missing row (√ 2 × 2 √ 2)-R45° O(a) structure. The results address the first stages in the formation of a copper chloride and present an interesting comparison with the HCl/O(a) reaction at Cu(110) surfaces, where oxygen also increased the extent of HCl reactions. The results emphasize the importance of the exothermic reaction to form water in the HCl/O(a) reaction on copper

The Analysis of Restrained Purlins Using Generalised Beam Theory

A paper presented at the Eleventh Speciality Conference in 1992(1) introduced the Generalized Beam Theory (GBT) and illustrated its use. It was used in ftrst-order analyses t0 calculate the stress distribution in a cross section takeing account of cross section distortion, and in second-order bifurcation problems to calculate the critical buckling load of a free cross section subject to axial load. Subsequent papers(2,3) have given more detailed information on the basis of GBT and used its second-order facilities to investigate the buckling of sections under both uniform and non-uniform bending moment. This paper extends the use of GBT to consider the behaviour of a cross section which is elastically restrained continuously along its length. A typical application of this facility is in the analysis of a purlin which receives both lateral and torsional restraint from the sheeting which it supports. The paper illustrates how the basic equations of GBT can be used to calculate the buckling load of an elastically restrained cross section taking account of interaction between the different buckling modes. Using this estimate of the buckling load, an assessment of the collapse load of a restrained section can be made using the interaction formulae of Eurocode 3(4) to allow for both buckling and yielding

Structural behaviour of copper chloride catalysts during the chlorination of CO to phosgene

The interaction of CO with an attapulgite-supported Cu(II)Cl2 catalyst has been examined in a micro-reactor arrangement. CO exposure to the dried, as-received catalyst at elevated temperatures leads to the formation of CO2 as the only identifiable product. However, phosgene production can be induced by a catalyst pre-treatment where the supported Cu(II)Cl2 sample is exposed to a diluted stream of chlorine. Subsequent CO exposure at ~ 370°C then leads to phosgene production. In order to investigate the origins of this atypical set of reaction characteristics, a series of x-ray absorption experiments were performed that were supplemented by DFT calculations. XANES measurements establish that at the elevated temperatures connected with phosgene formation, the catalyst is comprised of Cu+ and a small amount of Cu2+. Moreover, the data show that unique to the chlorine pre-treated sample, CO exposure at elevated temperature results in a short-lived oxidation of the copper. On the basis of calculated CO adsorption energies, DFT calculations indicate that a mixed Cu+/Cu2+ catalyst is required to support CO chemisorption

Practical guide for x-ray photoelectron spectroscopy: applications to the study of catalysts

X-ray photoelectron spectroscopy (XPS) has become a standard tool for the study of catalytic materials over the last two decades, and with the increasing popularity of turnkey XPS systems, the analysis of these types of materials is open to an even wider audience. However, increased accessibility leads to an increase in the number of new or inexperienced practitioners, leading to erroneous data collection and interpretation. Over many years of working on a wide range of catalytic materials, the authors have developed procedures for the planning and execution of XPS analysis and subsequent data analysis, and this guide has been produced to help users of all levels of expertise to question their approach toward analysis and get the most out of the technique and avoiding some common pitfalls

The pinprick approach: Whitehall’s top-secret anti-communist committee and the evolution of British covert action strategy

This article examines Great Britain’s approach to covert action during the formative years of British Cold War intelligence operations, 1950–1951. Rather than shy away from such activity in the wake of the failure in Albania in the late 1940s, the British increased the number of operations they pursued. This was the start of a coherent strategy regarding covert activity that can be conceptualized as the “pinprick” approach. The strategy was overseen by a highly secretive Whitehall body, the Official Committee on Communism, which in effect became the government’s covert action committee. This article uses the commission’s recently declassified papers for the first time to assess the merits of this approach

‘Getting Back Into the Swing of Things’: A Qualitative Study Into Barriers and Facilitators to Golf Participation for Stroke Survivors

This paper draws on interviews with four stroke survivors (age range = 52–68 years), who participated in a six week ‘Get-into-Golf’ program and four coaches with experiences of delivering disability golf sessions, to examine the barriers and facilitators to golf participation. Findings indicate a positive response from participants, who referred to the social and physical benefits of the program that was perceived to promote independence. The results also highlight that considerations in regards to format, equipment, cost, access and overall awareness should be borne in mind for golf programs among people with disabilities. Golf clubs could employ this framework to help facilitate the participation of people with physical limitations. It is argued that opportunities to promote golf as a lifelong physical activity among people with disabilities may be missed in clubs where personnel are unsure of the barriers and facilitators to participation outlined here