Simplified models for heating system optimisation using a thermal-electrical analogy

The well-known electrical analogy for thermal modelling is based on the observation that Fourier's equation for one dimensional heat transfer takes the same form as Ohm's law. This provides a system for creating and resolving complex heat transfer problems using an established set of physically-based laws. The present article illustrates the concept for adjacent rooms in a modern university building, and investigates some of the modelling issues involved. The electrical analogy is chosen so that the models can be extended and used for future research into demand-side control of multiple buildings on the university network, requiring a fast computation time. For illustrative purposes, the present article is limited to a relatively straightforward two-room system, for which the modelling equations are conveniently represented and solved using MATLAB-SIMULINK. The coefficients of this model are estimated from data using standard nonlinear optimisation tools. For comparison, the article also develops an equivalent multiple-input Transfer Function form of the model. Finally, suggestions are made for the inclusion of occupancy estimates in the model

A thermal-electrical analogy model of a four-floor building with occupancy estimation for heating system control

The well-known electrical analogy for thermal modelling is based on the observation that Fourier's equation for one dimensional heat transfer takes the same form as Ohm's law. This provides a system for creating and resolving complex heat transfer problems using an established set of physically-based equations. In this article, such a model is developed and evaluated for a four-floor modern university building. The model is represented in state space form for optimisation and simulation purposes. The electrical analogy is chosen so that the model can be extended and used for future research into distributed, demand-side control of multiple buildings on the university network, requiring a fast computation time. The estimation of occupancy, representing a significant internal heat source, is also investigated. Here, wifi usage and return CO2 data are combined in novel manner to improve the model response

Association Between Gabapentin Receipt for Any Indication and Alcohol Use Disorders Identification Test-Consumption Scores Among Clinical Subpopulations With and Without Alcohol Use Disorder.

BACKGROUND: Current medications for alcohol use disorder (AUD) have limited efficacy and utilization. Some clinical trials have shown efficacy for gabapentin among treatment-seeking individuals. The impact of gabapentin on alcohol consumption in a more general sample remains unknown. METHODS: We identified patients prescribed gabapentin for ≥180 consecutive days for any clinical indication other than substance use treatment between 2009 and 2015 in the Veterans Aging Cohort Study. We propensity-score matched each gabapentin-exposed patient with up to 5 unexposed patients. Multivariable difference-in-difference (DiD) linear regression models estimated the differential change in Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) scores during follow-up between exposed and unexposed patients, by baseline level of alcohol consumption and daily gabapentin dose. Analyses were stratified by AUD history. Clinically meaningful changes were a priori considered a DiD ≥1 point. RESULTS: Among patients with AUD, AUDIT-C scores decreased 0.39 points (95% confidence interval [CI] 0.05, 0.73) more among exposed than unexposed patients (p < 0.03). Potentially clinically meaningful differences were observed among those with AUD and exposed to ≥1,500 mg/d (DiD 0.77, 95% CI 0.15, 1.38, p < 0.02). No statistically significant effects were found among patients with AUD at doses lower than 1,500 mg/d or baseline AUDIT-C ≥4. Among patients without AUD, we found no overall difference in changes in AUDIT-C scores, nor in analyses stratified by baseline level of alcohol consumption. CONCLUSIONS: Patients exposed to doses of gabapentin consistent with those used in clinical trials, particularly those with AUD, experienced a greater decrease in AUDIT-C scores than matched unexposed patients

Electrochemical Benzylic C(sp3)−H Acyloxylation

[Image: see text] The development of sustainable C(sp(3))–H functionalization methods is of great interest to the pharmaceutical and agrochemical industries. Anodic oxidation is an efficient means of producing benzylic cations that can undergo subsequent in situ nucleophilic attack to afford functionalized benzylic products. Herein, we demonstrate the suitability of carboxylic acids as nucleophiles to yield benzylic esters. This method employs a series of secondary benzylic substrates and functionalized carboxylic acids and is demonstrated on a gram scale in flow

Strong position-dependent effects of sequence mismatches on signal ratios measured using long oligonucleotide microarrays

<p>Abstract</p> <p>Background</p> <p>Microarrays are an important and widely used tool. Applications include capturing genomic DNA for high-throughput sequencing in addition to the traditional monitoring of gene expression and identifying DNA copy number variations. Sequence mismatches between probe and target strands are known to affect the stability of the probe-target duplex, and hence the strength of the observed signals from microarrays.</p> <p>Results</p> <p>We describe a large-scale investigation of microarray hybridisations to murine probes with known sequence mismatches, demonstrating that the effect of mismatches is strongly position-dependent and for small numbers of sequence mismatches is correlated with the maximum length of perfectly matched probe-target duplex. Length of perfect match explained 43% of the variance in log₂signal ratios between probes with one and two mismatches. The correlation with maximum length of perfect match does not conform to expectations based on considering the effect of mismatches purely in terms of reducing the binding energy. However, it can be explained qualitatively by considering the entropic contribution to duplex stability from configurations of differing perfect match length.</p> <p>Conclusion</p> <p>The results of this study have implications in terms of array design and analysis. They highlight the significant effect that short sequence mismatches can have upon microarray hybridisation intensities even for long oligonucleotide probes.</p> <p>All microarray data presented in this study are available from the GEO database <abbrgrp><abbr bid="B1">1</abbr></abbrgrp>, under accession number [GEO: GSE9669]</p

Collaboration in the Semantic Grid: a Basis for e-Learning

The CoAKTinG project aims to advance the state of the art in collaborative mediated spaces for the Semantic Grid. This paper presents an overview of the hypertext and knowledge based tools which have been deployed to augment existing collaborative environments, and the ontology which is used to exchange structure, promote enhanced process tracking, and aid navigation of resources before, after, and while a collaboration occurs. While the primary focus of the project has been supporting e-Science, this paper also explores the similarities and application of CoAKTinG technologies as part of a human-centred design approach to e-Learning

Terrestrial organic carbon storage in a British moorland

Accurate estimates for the size of terrestrial organic carbon (C) stores are needed to determine their importance in regulating atmospheric CO2 concentrations. The C stored in vegetation and soil components of a British moorland was evaluated in order to: (i) investigate the importance of these ecosystems for C storage and (ii) test the accuracy of the United Kingdom's terrestrial C inventory. The area of vegetation and soil types was determined using existing digitized maps and a Geographical Information System (GIS). The importance of evaluating C storage using 2D area projections, as opposed to true surface areas, was investigated and found to be largely insignificant. Vegetation C storage was estimated from published results of productivity studies at the site supplemented by field sampling to evaluate soil C storage. Vegetation was found to be much less important for C storage than soil, with peat soils, particularly Blanket bog, containing the greatest amounts of C. Whilst the total amount of C in vegetation was similar to the UK national C inventory's estimate for the same area, the national inventory estimate for soil C was over three times higher than the value derived in the current study. Because the UK's C inventory can be considered relatively accurate compared to many others, the results imply that current estimates for soil C storage, at national and global scales, should be treated with caution

Computational Fluid Dynamics and Data-Based Mechanistic Modelling of a Forced Ventilation Chamber

The research behind this article ultimately concerns control system robustness and optimisation for the regulation of temperatures in multiple buildings that are linked to a controllable external heating supply network. Lancaster University campus is being used as a case study, for which the building management system provides data. Nonetheless, situations arise when it is difficult or expensive to obtain suitable data for specific rooms or buildings and, in such cases, computational fluid dynamics (CFD) models are utilised to investigate relevant heat transfer phenomena. Such models can be limited by their complexity and they are inappropriate for model-based control design. Hence, the present article investigates a hybrid approach based on both CFD and data-based mechanistic (DBM) models. DBM models are obtained initially from statistical analysis of observational time-series but are only considered credible if they can be interpreted in physically meaningful terms. A laboratory forced ventilation chamber is used to investigate the modelling issues arising and to make recommendations relating to the wider project. The chamber is first discretised into finite volumes and the associated Navier--Stokes equations are solved to determine the physical properties of each zone. The model responses are compared with experimental data and analysed using the DBM approach