A marginal abatement cost curve for material efficiency accounting for uncertainty

Comparing costs of measures to mitigate greenhouse gas is challenging as there are many competing notions of costs, and uncertainties associated with cost estimates. In addition, there are many different types of mitigation measures, from supply-side investment solutions to demand-side efficiency improvements, which may interact, risking double-counting of abatement potentials. This paper presents a novel, transparent methodology for building a marginal abatement cost curve that allows abatement costs and potentials to be compared. This curve improves over existing methods as it allows for abatement measures to be pursued in parallel, takes into account the interplay between abatement measures and captures data on cost uncertainty. The method is applied to build the first bottom-up marginal abatement cost curve for greater material efficiency steel use in the UK. This curve is demonstrated via four material efficiency measures which do not require large changes in final uses of products: reusing steel beams in construction, specifying optimal lightweight beams in construction, choosing smaller cars and specifying high strength steel car bodies. The results show that these strategies could reduce UK steel demand and associated global emissions by approximately 12%. 17% of this potential would be viable at the Department for Business, Energy \& Industrial Strategy (BEIS) 2030 carbon price for policy appraisal (79£/tCO2) taking into account emissions savings associated with steel demand only. Once use-phase emissions savings are taken into account this share increases to 60%. These results can be traced directly back to underlying assumptions regarding costs and emissions allocations

A new method to estimate the lifetime of long-life product categories

Increased recycling and reuse rates are a central part of the objectives laid out by the COP21. Nonetheless, the practical implementation of what has been called the circular economy, as well as its true potential are not easily established. This is because the impact and implementation time scales of any intervention depend on knowing the lifetime of products, which is frequently unknown. This is particularly true in construction, responsible for 39% of worldwide emissions, 11% of which are embodied. Most MFA models will simply assume a range of plausible life expectancies when bottom-up data is lacking (e.g. for buildings). In this work, we propose a novel method of identification using the high quality but highly aggregated trade data available, and use it to establish a “mortality curve” for buildings and other long-lasting products. This identification method is intended to provide more reliable inputs to existing MFA models. It is widely applicable due to the general availability of the underlying data. Using it on UK trade data, we identify product classes at 1 year for packaging/home scrap, one around 10 years for vehicles/equipment, and around 50 years for construction. The identification approach was then validated using classical approaches using bottom up data for vehicles

Options to make steel reuse profitable: An analysis of cost and risk distribution across the UK construction value chain

Although steel reuse has been identified as an effective method to reduce the carbon and energy impact of construction, it is in effect only a marginal practice. A detailed analysis of the costs and risks of reuse in practice in the uk is lacking. We found that although there is a sufficient spread between the price of steel scrap and new steel, this difference cannot be captured by the demolition contractors. Rather, reused steel is somewhat more expensive than new elements, except in certain circumstances such as when the reused elements are available from a nearby site, or when testing elements can be avoided. Further, we show that neither the costs of steel reuse, nor the risks, nor its benefits are spread equitably throughout the construction industry supply chain: most of the substantial and capital-intensive changes required for the widespread adoption of steel reuse are concentrated on steelwork contractors and stockists. Based on this analysis, we suggest helping the emergence of a specialised stockist.This research was supported by Innovate UK, project ‘Supply Chain Integration for structural steel reuse’, ref. 132106; EPSRC Material demand reduction: NMZL/112, RG82144, EPSRC reference: EP/N02351X/1

Real and perceived barriers to steel reuse across the UK construction value chain

© 2017 Elsevier B.V. Although steel reuse has been identified as an effective method to reduce the carbon and energy impact of construction, its occurrence is shrinking in the UK. This can be partly explained by the many barriers which have been identified in the literature, but a detailed analysis of how these barriers affect different parts of the supply chain is still lacking. We show that there is a contrast between perceived higher costs and time required to employ reused steel and the assessments of realised projects. Using a novel ranking method inspired from the field of information retrieval (tf-idf), we have analysed interviews of actors across the supply chain to determine the acuteness of the perception of each barrier. We show that demolition contractors, stockists, and fabricators face specific barriers which each need to be addressed at their level. This is in contrast with more generic barriers present throughout the value chain which we show are probably more perception than reality. Finally, we suggest how supply chain integration could facilitate reuse and make it economically viable at scale

Regularity and optimisation practice in steel structural frames in real design cases

Large amounts of energy and carbon are embodied in the frames of buildings, making efficient structural design a key aspect of reducing the carbon footprint of buildings. Similarly to a previous study which analysed real structures had observed that the unused mass of steel framed building could amount to nearly 46 % of the total mass due to over-specification of the sections, we find a value of 36 %. We observe that this value correlates with the design method, with software-aided design bringing significant improvements and with the design stage, where most of the optimisation seem to occur between the preliminary and tender stage. We find that neither the regularity of the structure nor the cost, independent of the measure used, correlate with the mean utilisation ratio (ur). Conversely, we observe an apparent reluctance to design beams above a 0.8 capacity ur. This reluctance explains most of the unused mass in buildings. The rest of unused mass consists in cores, trimmers and ties (6 %), some of which bear loads not captured in this analysis but are otherwise necessary for stability reasons, and in edge secondary beams (3 %) which design is constrained, and should not necessarily be considered as ‘unused’ mass

Fission yeast Pcp1 links polo kinase-mediated mitotic entry to γ-tubulin-dependent spindle formation

The centrosomal pericentrin-related proteins play pivotal roles in various aspects of cell division; however their underlying mechanisms remain largely elusive. Here we show that fission-yeast pericentrin-like Pcp1 regulates multiple functions of the spindle pole body (SPB) through recruiting two critical factors, the γ-tubulin complex (γ-TuC) and polo kinase (Plo1). We isolated two pcp1 mutants (pcp1-15 and pcp1-18) that display similar abnormal spindles, but with remarkably different molecular defects. Both mutants exhibit defective monopolar spindle microtubules that emanate from the mother SPB. However, while pcp1-15 fails to localise the γ-TuC to the mitotic SPB, pcp1-18 is specifically defective in recruiting Plo1. Consistently Pcp1 forms a complex with both γ-TuC and Plo1 in the cell. pcp1-18 is further defective in the mitotic-specific reorganisation of the nuclear envelope (NE), leading to impairment of SPB insertion into the NE. Moreover pcp1-18, but not pcp1-15, is rescued by overproducing nuclear pore components or advancing mitotic onset. The central role for Pcp1 in orchestrating these processes provides mechanistic insight into how the centrosome regulates multiple cellular pathways

Integrand reduction of one-loop scattering amplitudes through Laurent series expansion

We present a semi-analytic method for the integrand reduction of one-loop amplitudes, based on the systematic application of the Laurent expansions to the integrand-decomposition. In the asymptotic limit, the coefficients of the master integrals are the solutions of a diagonal system of equations, properly corrected by counterterms whose parametric form is konwn a priori. The Laurent expansion of the integrand is implemented through polynomial division. The extension of the integrand-reduction to the case of numerators with rank larger than the number of propagators is discussed as well.Comment: v2: Published version: references and two appendices added. v3: Eq.(6.11) corrected, Appendix B updated accordingl

Scaling Patterns for QCD Jets

Jet emission at hadron colliders follows simple scaling patterns. Based on perturbative QCD we derive Poisson and staircase scaling for final state as well as initial state radiation. Parton density effects enhance staircase scaling at low multiplicities. We propose experimental tests of our theoretical findings in Z+jets and QCD gap jets production based on minor additions to current LHC analyses.Comment: 36 pages, 16 figure

On the Integrand-Reduction Method for Two-Loop Scattering Amplitudes

We propose a first implementation of the integrand-reduction method for two-loop scattering amplitudes. We show that the residues of the amplitudes on multi-particle cuts are polynomials in the irreducible scalar products involving the loop momenta, and that the reduction of the amplitudes in terms of master integrals can be realized through polynomial fitting of the integrand, without any apriori knowledge of the integral basis. We discuss how the polynomial shapes of the residues determine the basis of master integrals appearing in the final result. We present a four-dimensional constructive algorithm that we apply to planar and non-planar contributions to the 4- and 5-point MHV amplitudes in N=4 SYM. The technique hereby discussed extends the well-established analogous method holding for one-loop amplitudes, and can be considered a preliminary study towards the systematic reduction at the integrand-level of two-loop amplitudes in any gauge theory, suitable for their automated semianalytic evaluation.Comment: 26 pages, 11 figure

The breast feeding mother and xenon anaesthesia: four case reports. Breast feeding and xenon anaesthesia

<p>Abstract</p> <p>Background</p> <p>Four nursing mothers consented to anaesthesia for urgent surgery only on condition that their ability to breast feed would not be impaired.</p> <p>Methods</p> <p>Following induction of general anaesthesia with propofol and remifentanil, 65-69% xenon supplemented with remifentanil was used as an inhalational anaesthetic for maintenance.</p> <p>Results</p> <p>After finishing surgery the women could be extubated between 2:52 and 7:22 minutes. The women were fully alert just minutes after extubation and spent about 45 minutes in the recovery room before discharge to a regular ward. They resumed regular breast feeding some time later. The propofol concentration in the blood was measured after 0, 30, 90, and 300 minutes and in the milk after 90 and 300 minutes. Just 90 minutes after extubation, the concentration of propofol in the milk was limited (> 3 mg/l) so that pharmacological effects on the babies were excluded after oral intake. Also, no traces of xenon gas were found in the maternal milk at any time. After propofol induction and maintenance of anaesthesia with xenon in combination with a water-soluble short-acting drug like remifentanil, the concentration of propofol in maternal milk is low (> 3 mg/l 90 min after anesthesia) and harmless after oral intake.</p> <p>Conclusions</p> <p>These results, as well as the rapid elimination and absence of metabolism of xenon, are of great interest to nursing mothers. General anaesthesia with propofol for induction only, combined with remifentanil and xenon for maintenance, has not yet been described in breast feeding mothers.</p