Unlocking Plant-level Resource Efficiency Options: A Unified Exergy Measure

AbstractIn this research we propose a physical measure of resource efficiency, based on exergy, which combines energy and material flows in a single dimensionless metric, bounded by 0 and 1. The inclusion of materials in the efficiency metric makes it possible to compare a wide range of industrial devices and processes, and even different sectors, using a consistent framework. Resource efficiencies for steel-making processes were computed as an example and were found to range from 10.0% in sinter plants to72.1% in coke ovens. A unified resource efficiency measure helps identify the drivers of resource consumption and reveal opportunities to reduce carbon emissions

Exergy: A universal metric for measuring resource efficiency to address industrial decarbonisation

© 2019 Institution of Chemical Engineers To achieve agreed targets for reducing global carbon emissions, industry must become more resource-efficient. To this end, two viable strategies exist: energy efficiency and material efficiency. Despite the inherent interdependence of energy and materials in industrial processes, policy and industry treat these two strategies as isolated pursuits, which provides only a partial insight into potential gains from resource efficiency. To resolve this disconnect, we review 34 resource efficiency metrics from the literature and evaluate their effectiveness at driving the sector's low-carbon transition. We then evaluate five selected resource efficiency metrics, in more detail, against the RACER evaluation methodology, using the criteria: Relevance, Acceptance, Credibility, Easiness and Robustness. The results point to the effectiveness of employing a Resource Efficiency metric based on the thermodynamic concept of exergy. Exergy-based Resource Efficiency metrics score highest in Relevance and Robustness, traits which are inherent to the metric and cannot be changed. However, exergy efficiency scores lower for Acceptance, indicating further advocacy is required for it to be accepted as a mainstream measure of resource efficiency. More work is required to provide simple guides, training and software tools, to facilitate wider use of exergy efficiency in the resource efficiency narrative. We hope that this paper, is a first step towards demystifying exergy and will spur further discussion about the use of exergy-based metrics for measuring Resource Efficiency

Ambiguity helps: classification with disagreements in crowdsourced annotations

Imagine we show an image to a person and ask her/him to decide whether the scene in the image is warm or not warm, and whether it is easy or not to spot a squirrel in the image. For exactly the same image, the answers to those questions are likely to differ from person to person. This is because the task is inherently ambiguous. Such an ambiguous, therefore challenging, task is pushing the boundary of computer vision in showing what can and can not be learned from visual data. Crowdsourcing has been invaluable for collecting annotations. This is particularly so for a task that goes beyond a clear-cut dichotomy as multiple human judgments per image are needed to reach a consensus. This paper makes conceptual and technical contributions. On the conceptual side, we define disagreements among annotators as privileged information about the data instance. On the technical side, we propose a framework to incorporate annotation disagreements into the classifiers. The proposed framework is simple, relatively fast, and outperforms classifiers that do not take into account the disagreements, especially if tested on high confidence annotations

Leveraging material efficiency as an energy and climate instrument for heavy industries in the EU

Material efficiency is indispensable to reaching agreed targets for industry's energy and carbon emissions. Yet, in the EU, the energy- and emissions-saving potentials of this strategy continue to be framed as secondary outcomes of resource-related policies. Understanding why material efficiency has been overlooked as an energy/climate solution is a prerequisite for proposing ways of changing its framing, but existing studies have failed to do so. This paper fills this gap by triangulating interviews, policy documents and three policy theories: namely, historical and rational choice institutionalism, and multiple streams framework. Factors discouraging material efficiency as an energy and climate strategy include: difficulties in reframing the prevailing rationale to pursue it; the inadequacy of monitored indicators; the lack of high-level political buy-in from DG Energy and Clima; the ETS policy lock-in; uncoordinated policy management across Directorates; the lack of a designated industry lobby. Policy solutions are proposed. Before 2030, these are limited to minor amendments, e.g. guidance on embodied energy calculations or industry standards. Post-2030, more radical interventions are possible, such as introducing new fiscal drivers, re-designing the ETS emissions cap or benchmarks for allowances. This evidence suggests that the transition to a low-carbon industry will require Member State- and industry-level action.Emerson Electric co

A comparison of location of acute symptomatic vs. 'silent' small vessel lesions

Background: Acute lacunar ischaemic stroke, white matter hyperintensities, and lacunes are all features of cerebral small vessel disease. It is unclear why some small vessel disease lesions present with acute stroke symptoms, whereas others typically do not. Aim: To test if lesion location could be one reason why some small vessel disease lesions present with acute stroke, whereas others accumulate covertly. Methods: We identified prospectively patients who presented with acute lacunar stroke symptoms with a recent small subcortical infarct confirmed on magnetic resonance diffusion imaging. We compared the distribution of the acute infarcts with that of white matter hyperintensity and lacunes using computational image mapping methods. Results: In 188 patients, mean age 67 ± standard deviation 12 years, the lesions that presented with acute lacunar ischaemic stroke were located in or near the main motor and sensory tracts in (descending order): posterior limb of the internal capsule (probability density 0·2/mm3), centrum semiovale (probability density = 0·15/mm3), medial lentiform nucleus/lateral thalamus (probability density = 0·09/mm3), and pons (probability density = 0·02/mm3). Most lacunes were in the lentiform nucleus (probability density = 0·01–0·04/mm3) or external capsule (probability density = 0·05/mm3). Most white matter hyperintensities were in centrum semiovale (except for the area affected by the acute symptomatic infarcts), external capsules, basal ganglia, and brainstem, with little overlap with the acute symptomatic infarcts (analysis of variance, P < 0·01). Conclusions: Lesions that present with acute lacunar ischaemic stroke symptoms may be more likely noticed by the patient through affecting the main motor and sensory tracts, whereas white matter hyperintensity and asymptomatic lacunes mainly affect other areas. Brain location could at least partly explain the symptomatic vs. covert development of small vessel disease

More three-point correlators of giant magnons with finite size

In the framework of the semiclassical approach, we compute the normalized structure constants in three-point correlation functions, when two of the vertex operators correspond to heavy string states, while the third vertex corresponds to a light state. This is done for the case when the heavy string states are finite-size giant magnons with one or two angular momenta, and for two different choices of the light state, corresponding to dilaton operator and primary scalar operator. The relevant operators in the dual gauge theory are Tr(F_{\mu\nu}^2 Z^j+...) and Tr(Z^j). We first consider the case of AdS_5 x S^5 and N = 4 super Yang-Mills. Then we extend the obtained results to the gamma-deformed AdS_5 x S^5_\gamma, dual to N = 1 super Yang-Mills theory, arising as an exactly marginal deformation of N = 4 super Yang-Mills.Comment: 14 pages, no figure

Use of Non-Steroidal Anti-Inflammatory Drugs That Elevate Cardiovascular Risk: An Examination of Sales and Essential Medicines Lists in Low-, Middle-, and High-Income Countries

PMCID: PMC3570554This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Correlation functions of three heavy operators - the AdS contribution

We consider operators in N=4 SYM theory which are dual, at strong coupling, to classical strings rotating in S^5. Three point correlation functions of such operators factorize into a universal contribution coming from the AdS part of the string sigma model and a state-dependent S^5 contribution. Consequently a similar factorization arises for the OPE coefficients. In this paper we evaluate the AdS universal factor of the OPE coefficients which is explicitly expressed just in terms of the anomalous dimensions of the three operators.Comment: 49 pages, 3 figures; v.2 references corrected; v3: corrected discussion in section 5, results unchange

Control data, Sankey diagrams, and exergy: Assessing the resource efficiency of industrial plants

Studies analysing the resource use of industrial production are often performed at highly aggregated levels, e.g. yearly across industry sectors. Conversely, the remit of work performed at the operational level is limited to the management of energy or concerned with aspects such as safety or reliability, both of which fail to consider material efficiency options at that scale. This gap is filled by applying the concept of exergy to the disaggregated time-scales and scopes typical of real-time operations. Our tool measures the resource efficiency of processes and visually traces the use of both energy and materials from available control data. This is exemplified through the case study of a Tata Steel basic oxygen steelmaking plant, where resource flows are visualised using Sankey diagrams. An analysis of the resource efficiency variations across batches and days for a period of 30 days - over 900 batches - show the plant's inefficiencies primarily arise from the converter process, the resource efficiency of which varies from 87.4% to 93.7%. By recovering material and energy by-products, and reducing fuel inputs we estimate that 7% of the total exergy input can be saved or further utilised. About 60% of these improvements arise from energy-related measures. The remaining 40% emanates from reductions in material use, a contribution which would be missed if using conventional energy metrics. This approach makes three contributions. First, it gives industry a single metric of resource efficiency that can jointly measure the system-level performance of material and energy transformations. Second, it provides a new picture of the plant's operational resource use. Third, it allows managers to have more detailed information on resource flows and thus helps place material-efficiency improvements on an equal footing to energy efficiency. This, therefore, provides a clearer picture of where interventions can deliver the greatest efficiency gains.This research is funded by Emerson Electric co. This study was supported by Tata Steel UK

Wave functions and correlation functions for GKP strings from integrability

We develop a general method of computing the contribution of the vertex operators to the semi-classical correlation functions of heavy string states, based on the state-operator correspondence and the integrable structure of the system. Our method requires only the knowledge of the local behavior of the saddle point configuration around each vertex insertion point and can be applied to cases where the precise forms of the vertex operators are not known. As an important application, we compute the contributions of the vertex operators to the three-point functions of the large spin limit of the Gubser-Klebanov-Polyakov (GKP) strings in $AdS_3$ spacetime, left unevaluated in our previous work [arXiv:1110.3949] which initiated such a study. Combining with the finite part of the action already computed previously and with the newly evaluated divergent part of the action, we obtain finite three-point functions with the expected dependence of the target space boundary coordinates on the dilatation charge and the spin.Comment: 80 pages, 7 figures, v2: typos and minor errors corrected, a reference added, v3: typos and a reference corrected, published versio