313 research outputs found

    Operational Effectiveness in Use fo BAS

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    The effectiveness of BAS in controlling building systems is seen to reside in conjoint man machine function. In an emerging industry paradigm, data is extracted from the BAS and used for analytics that inform enhanced operations. This processing may include a mash up with data from other sources, such as energy meters. KPI metrics and Building ReTuning, an on going commissioning process, are suggested as important ways to guide operators in training and subsequent understanding and use of data intensive tools. Short case studies of work in progress on two CUNY campuses are provided

    Operational Effectiveness in Use fo BAS

    Get PDF
    The effectiveness of BAS in controlling building systems is seen to reside in conjoint man machine function. In an emerging industry paradigm, data is extracted from the BAS and used for analytics that inform enhanced operations. This processing may include a mash up with data from other sources, such as energy meters. KPI metrics and Building ReTuning, an on going commissioning process, are suggested as important ways to guide operators in training and subsequent understanding and use of data intensive tools. Short case studies of work in progress on two CUNY campuses are provided

    Conformational and Structural Relaxations of Poly(ethylene oxide) and Poly(propylene oxide) Melts: Molecular Dynamics Study of Spatial Heterogeneity, Cooperativity, and Correlated Forward-Backward Motion

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    Performing molecular dynamics simulations for all-atom models, we characterize the conformational and structural relaxations of poly(ethylene oxide) and poly(propylene oxide) melts. The temperature dependence of these relaxation processes deviates from an Arrhenius law for both polymers. We demonstrate that mode-coupling theory captures some aspects of the glassy slowdown, but it does not enable a complete explanation of the dynamical behavior. When the temperature is decreased, spatially heterogeneous and cooperative translational dynamics are found to become more important for the structural relaxation. Moreover, the transitions between the conformational states cease to obey Poisson statistics. In particular, we show that, at sufficiently low temperatures, correlated forward-backward motion is an important aspect of the conformational relaxation, leading to strongly nonexponential distributions for the waiting times of the dihedrals in the various conformational statesComment: 13 pages, 13 figure

    Serotonin and corticosterone rhythms in mice exposed to cigarette smoke and in patients with COPD:implication for COPD-associated neuropathogenesis

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    The circadian timing system controls daily rhythms of physiology and behavior, and disruption of clock function can trigger stressful life events. Daily exposure to cigarette smoke (CS) can lead to alteration in diverse biological and physiological processes. Smoking is associated with mood disorders, including depression and anxiety. Patients with chronic obstructive pulmonary disease (COPD) have abnormal circadian rhythms, reflected by daily changes in respiratory symptoms and lung function. Corticosterone (CORT) is an adrenal steroid that plays a considerable role in stress and anti-inflammatory responses. Serotonin (5-hydroxytryptamine; 5HT) is a neurohormone, which plays a role in sleep/wake regulation and affective disorders. Secretion of stress hormones (CORT and 5HT) is under the control of the circadian clock in the suprachiasmatic nucleus. Since smoking is a contributing factor in the development of COPD, we hypothesize that CS can affect circadian rhythms of CORT and 5HT secretion leading to sleep and mood disorders in smokers and patients with COPD. We measured the daily rhythms of plasma CORT and 5HT in mice following acute (3 d), sub-chronic (10 d) or chronic (6 mo) CS exposure and in plasma from non-smokers, smokers and patients with COPD. Acute and chronic CS exposure affected both the timing (peak phase) and amplitude of the daily rhythm of plasma CORT and 5HT in mice. Acute CS appeared to have subtle time-dependent effects on CORT levels but more pronounced effects on 5HT. As compared with CORT, plasma 5HT was slightly elevated in smokers but was reduced in patients with COPD. Thus, the effects of CS on plasma 5HT were consistent between mice and patients with COPD. Together, these data reveal a significant impact of CS exposure on rhythms of stress hormone secretion and subsequent detrimental effects on cognitive function, depression-like behavior, mood/anxiety and sleep quality in smokers and patients with COPD

    Kilocalorie labelling in the out-of-home sector: an observational study of business practices and consumer behaviour prior to implementation of the mandatory calorie labelling policy in England, 2022

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    Background: Regulations mandating kilocalorie (kcal) labelling for large businesses in the out-of-home food sector (OHFS) came into force on 6th April 2022 as a policy to reduce obesity in England. To provide indicators of potential reach and impact, kcal labelling practices were studied in the OHFS, and customer purchasing and consumption behaviours prior to implementation of the mandatory kcal labelling policy in England. Methods: From August-December 2021, large OHFS businesses subject to the kcal labelling regulations were visited prior to regulations coming into force on 6th April 2022. 3308 customers were recruited from 330 outlets and collected survey information on the number of kcal purchased and consumed by customers, customers’ knowledge of the kcal content of their purchases, and customers noticing and use of kcal labelling. In a subset of 117 outlets, data was collected on nine recommended kcal labelling practices. Results: The average number of kcals purchased (1013 kcal, SD = 632 kcal) was high with 69% of purchases exceeding the recommendation of a maximum of 600 kcal per meal. Participants underestimated the energy content of their purchased meals by on average 253 kcal (SD = 644 kcals). In outlets providing kcal labelling in which customer survey data was collected, a minority of customers reported noticing (21%) or using (20%) kcal labelling. Out of the 117 outlets assessed for kcal labelling practices, 24 (21%) provided any in-store kcal labelling. None of the outlets met all nine aspects of recommended labelling practices. Conclusions: Prior to implementation of 2022 kcal labelling policy, the majority of sampled OHFS large business outlets in England did not provide kcal labelling. Few customers noticed or used the labels and on average customers purchased and consumed substantially more energy than recommended in public health guidelines. The findings suggest that reliance on voluntary action for kcal labelling implementation failed to produce widespread, consistent, and adequate kcal labelling practices

    A critical assessment of methods for the intrinsic analysis of liquid interfaces: 2. density profiles

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    Substantial improvements in the molecular level understanding of fluid interfaces have recently been achieved by recognizing the importance of detecting the intrinsic surface of the coexisting condensed phases in computer simulations (i.e., after the removal of corrugations caused by capillary waves) and by developing several methods for identifying the molecules that are indeed located at the boundary of the two phases. In our previous paper [J. Phys. Chem. C 2010, 114, 11169], we critically compared those methods in terms of reliability, robustness, and computation speed. Once the intrinsic surface of a given phase is detected, various profiles, such as the density profiles of the components, can be calculated relative to this intrinsic surface rather than to the macroscopically planar Gibbs dividing surface. As a continuation of our previous study, here we present a detailed and critical comparison of various methods that can be used to calculate intrinsic density profiles once the full set of truly interfacial molecules has been identified. Two of the methods, the Fourier function and the Voronoi tessellation, are already described in the literature; two other methods, the covering surface and the triangular interpolation, are newly proposed algorithms; one method, the modified grid-based intrinsic profile (GIP) method, is an improvement over an existing procedure. The different methods are again compared in terms of accuracy and computational cost. On the basis of this comparison, we propose a fast and accurate protocol to be routinely used for intrinsic surface analyses in computer simulations

    A critical assessment of methods for the intrinsic analysis of liquid interfaces. 1. surface site distributions

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    Substantial progress in our understanding of interfacial structure and dynamics has stemmed from the recent development of algorithms that allow for an intrinsic analysis of fluid interfaces. These work by identifying the instantaneous location of the interface, at the atomic level, for each molecular configuration and then computing properties relative to this location. Such a procedure eliminates the broadening of the interface caused by capillary waves and reveals the underlying features of the system. However, a precise definition of which molecules actually belong to the interfacial layer is difficult to achieve in practice. Furthermore, it is not known if the different intrinsic analysis methods are consistent with each other and yield similar results for the interfacial properties. In this paper, we carry out a systematic and detailed comparison of the available methods for intrinsic analysis of fluid interfaces, based on a molecular dynamics simulation of the interface between liquid water and carbon tetrachloride. We critically assess the advantages and shortcomings of each method, based on reliability, robustness, and speed of computation, and establish consistent criteria for determining which molecules belong to the surface layer. We believe this will significantly contribute to make intrinsic analysis methods widely and routinely applicable to interfacial systems

    Point-of-choice kilocalorie labelling practices in large, out-of-home food businesses: a preobservational versus post observational study of labelling practices following implementation of The Calorie Labelling (Out of Home Sector) (England) Regulations 2021.

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    BACKGROUND AND OBJECTIVES: On 6 April 2022, the UK government implemented mandatory kilocalorie (kcal) labelling regulations for food and drink products sold in the out-of-home food sector (OHFS) in England. Previous assessments of kcal labelling practices in the UK OHFS found a low prevalence of voluntary implementation and poor compliance with labelling recommendations. This study aimed to examine changes in labelling practices preimplementation versus post implementation of mandatory labelling regulations in 2022. METHODS: In August-December 2021 (preimplementation) and August-November 2022 (post implementation), large OHFS businesses (250 or more employees) subject to labelling regulations were visited. At two time points, a researcher visited the same 117 food outlets (belonging to 90 unique businesses) across four local authorities in England. Outlets were rated for compliance with government regulations for whether kcal labelling was provided at any or all point of choice, provided for all eligible food and drink items, provided per portion for sharing items, if labelling was clear and legible and if kcal reference information was displayed. RESULTS: There was a significant increase (21% preimplementation vs 80% post implementation, OR=40.98 (95% CI 8.08 to 207.74), p<0.001) in the proportion of outlets providing any kcal labelling at point-of-choice post implementation. Only 15% of outlets met all labelling compliance criteria post implementation, with a minority of outlets not presenting labelling in a clear (33%) or legible (29%) way. CONCLUSION: The number of large businesses in the OHFS providing kcal labelling increased following the implementation of mandatory labelling regulations. However, around one-fifth of eligible outlets sampled were not providing kcal labelling 4-8 months after the regulations came into force, and the majority of businesses only partially complied with government guidance. More effective enforcement may be required to further improve kcal labelling practices in the OHFS in England. PREREGISTRATION: Study protocol and analysis strategy preregistered on Open Science Framework (https://osf.io/pfnm6/)

    Molecular dynamics simulation of the early stages of the synthesis of periodic mesoporous silica

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    We present results of detailed atomistic modeling of the early stages of the synthesis of periodic mesoporous silica using molecular dynamics. Our simulations lead to the proposal of a mechanism that validates several previous experimental and modeling studies and answers many controversial issues regarding the synthesis of mesoporous silicas. In particular, we show that anionic silicates interact very strongly with cationic surfactants and, significantly adsorb on the surface of micelles, displacing a fraction of previously bound bromide counterions. This induces an increase in micelle size and also enhances silica condensation at the micelle surface. The presence of larger silica aggregates in solution further promotes the growth of micelles and, by binding to surfactant molecules in different micelles, their aggregation. This work demonstrates the crucial role played by silica in influencing, by way of a cooperative templating mechanism, the structure of the eventual liquid-crystal phase, which in turn determines the structure of the porous material
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