63 research outputs found
An epidemiological approach to simulation-based analysis of large building stocks
This paper describes a novel approach to building stock energy modelling: Individual building simulation models are autogenerated for each building in the stock, and the resulting set of virtual buildings is selectively sampled, simulated and analysed in much the same way that an epidemiologist might study a population through surveys and statistical analysis. A conceptual and software framework is described, along with initial case study results for a London borough
Demand Relief and Weather Sensitivity in Large California Commercial Office Buildings
A great deal of research has examined the
weather sensitivity of energy consumption in
commercial buildings; however, the recent
power crisis in California has given greater
importance to peak demand. Several new loadshedding
programs have been implemented or
are under consideration.
Historically, the target customers have been
large industrial users who can reduce the
equivalent load of several large office buildings.
While the individual load reduction from an
individual office building may be less
significant, there is ample opportunity for load
reduction in this area.
The load reduction programs and incentives
for industrial customers may not be suitable for
commercial building owners. In particular,
industrial customers are likely to have little
variation in load from day to day. Thus a robust
baseline accounting for weather variability is
required to provide building owners with
realistic targets that will encourage them to
participate in load shedding programs
Comments on Non-Commutative Phenomenology
It is natural to ask whether non-commutative geometry plays a role in four
dimensional physics. By performing explicit computations in various toy models,
we show that quantum effects lead to violations of Lorentz invariance at the
level of operators of dimension three or four. The resulting constraints are
very stringent.Comment: Correction of an error in the U(1) and U(N) calculation leads to
stronger limits than those given previously Clarifying comments and reference
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Using SPARK as a Solver for Modelica
Modelica is an object-oriented acausal modeling language that is well positioned to become a de-facto standard for expressing models of complex physical systems. To simulate a model expressed in Modelica, it needs to be translated into executable code. For generating run-time efficient code, such a translation needs to employ algebraic formula manipulations. As the SPARK solver has been shown to be competitive for generating such code but currently cannot be used with the Modelica language, we report in this paper how SPARK's symbolic and numerical algorithms can be implemented in OpenModelica, an open-source implementation of a Modelica modeling and simulation environment. We also report benchmark results that show that for our air flow network simulation benchmark, the SPARK solver is competitive with Dymola, which is believed to provide the best solver for Modelica
Is there evidence for cosmic anisotropy in the polarization of distant radio sources?
Measurements of the polarization angle and orientation of cosmological radio
sources may be used to search for unusual effects in the propagation of light
through the universe. Recently, Nodland and Ralston (astro-ph/9704196) have
claimed to find evidence for a redshift- and direction-dependent rotation
effect in existing data. We re-examine these data and argue that there is no
statistically significant signal present. We are able to place stringent limits
on hypothetical chiral interactions of photons propagating through spacetime.Comment: 17 pages, including 7 figures. (Arithmetic error corrected, fixing
value of chi^2
Optical Activity of a Neutrino Gas
For photons that propagate through a gas of neutrinos with a non-zero
chemical potential, the left-handed and right-handed polarization modes acquire
different dispersion relations. This is due to the CP and CPT-odd terms induced
by such a background on the photon self-energy. We present a detailed
calculation of this effect, which does not depend on any physical assumptions
beyond those of the standard electroweak model. Some possible cosmological and
astrophysical implications of our results are considered in several contexts,
including the recent discussions regarding the rotation of the plane of
polarization of electromagnetic waves over cosmological distances.Comment: latex, axodra
Brain inflammation is accompanied by peripheral inflammation in Cstb(-/-) mice, a model for progressive myoclonus epilepsy
Progressive myoclonus epilepsy of Unverricht-Lundborg type (EPM1) is an autosomal recessively inherited childhood-onset neurodegenerative disorder, characterized by myoclonus, seizures, and ataxia. Mutations in the cystatin B gene (CSTB) underlie EPM1. The CSTB-deficient (Cstb(-/-)) mouse model recapitulates key features of EPM1, including myoclonic seizures. The mice show early microglial activation that precedes seizure onset and neuronal loss and leads to neuroinflammation. We here characterized the inflammatory phenotype of Cstb(-/-) mice in more detail. We found higher concentrations of chemokines and pro-inflammatory cytokines in the serum of Cstb(-/-) mice and higher CXCL13 expression in activated microglia in Cstb(-/-) compared to control mouse brains. The elevated chemokine levels were not accompanied by blood-brain barrier disruption, despite increased brain vascularization. Macrophages in the spleen and brain of Cstb(-/-) mice were predominantly pro-inflammatory. Taken together, these data show that CXCL13 expression is a hallmark of microglial activation in Cstb(-/-)mice and that the brain inflammation is linked to peripheral inflammatory changes, which might contribute to the disease pathology of EPM1.Peer reviewe
Connecting the sustainable development goals by their energy inter-linkages
The United Nations' Sustainable Development Goals (SDGs) provide guide-posts to society as it attempts to respond to an array of pressing challenges. One of these challenges is energy; thus, the SDGs have become paramount for energy policy-making. Yet, while governments throughout the world have already declared the SDGs to be 'integrated and indivisible', there are still knowledge gaps surrounding how the interactions between the energy SDG targets and those of the non-energy-focused SDGs might play out in different contexts. In this review, we report on a large-scale assessment of the relevant energy literature, which we conducted to better our understanding of key energy-related interactions between SDGs, as well as their context-dependencies (relating to time, geography, governance, technology, and directionality). By (i) evaluating the nature and strength of the interactions identified, (ii) indicating the robustness of the evidence base, the agreement of that evidence, and our confidence in it, and (iii) highlighting critical areas where better understanding is needed or context dependencies should be considered, our review points to potential ways forward for both the policy making and scientific communities. First, we find that positive interactions between the SDGs outweigh the negative ones, both in number and magnitude. Second, of relevance for the scientific community, in order to fill knowledge gaps in critical areas, there is an urgent need for interdisciplinary research geared toward developing new data, scientific tools, and fresh perspectives. Third, of relevance for policy-making, wider efforts to promote policy coherence and integrated assessments are required to address potential policy spillovers across sectors, sustainability domains, and geographic and temporal boundaries. The task of conducting comprehensive science-to-policy assessments covering all SDGs, such as for the UN's Global Sustainable Development Report, remains manageable pending the availability of systematic reviews focusing on a limited number of SDG dimensions in each case
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Testing rapmod: Can a portable scanner collect exisitng building data and create an energy model faster and more accurately than a human
The paper describes the testing of a portable scanning system (RAPMOD), which is worn like a backpack and allows the user to walk through a building to collect essential energy-related data. From this walkthrough, the system collects data required for an energy model of the building using laser scanners, infrared scanners and cameras and converts these data into .idf format for use in EnergyPlus. The energy model includes the geometry of interior and exterior surfaces, window U-values, lighting levels, equipment levels and occupancy for each room. RAPMOD will be extended to include HVAC recognition in a subsequent phase of development. The main goal is to reduce the cost and skill level required to create energy simulation models for deep retrofit assessments, energy audits and retro commissioning for existing buildings through rapid and accurate energy model creation
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