6,328 research outputs found

    Sizing guidelines for grid-connected decentralised energy storage systems: single house application

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    Nowadays, the existing hierarchical, centrally controlled power grid faces new challenges due to the increase penetration of renewable sources, the need of implementing demand side management and the 2020 and 2050 environmental targets. A promising concept which can successfully contribute to addressing the environmental concerns and energy challenges of the 21st century is the grid-connected decentralised energy systems that embed significant amount of renewable generation and allow reverse power flow from distribution grids into the transmission network. Despite their benefits, decentralised energy storage systems are not yet widely spread due to several implementation and designing barriers. The design obstacle which is being addressed in this study includes the determination of the optimal size of the energy storage system components in terms of battery size and rating of the power converter for a single house application. In order to generalise the findings, 9 different real houses were considered. Thus, the most financially beneficial battery and power converter combination for 9 existing UK houses with installed PV roof-top system were identified in this study

    The effect of including power converter losses when modelling energy storage systems: a UK domestic study

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    Energy storage systems (ESS) are seen as an increasingly important technology for managing electrical distribution systems, and there is now much research into both the underlying technologies of these systems, and their “optimum” management especially for applications within a single household. Optimum management usually depends on many factors and assumptions, for example what should be optimized (self-consumption of local renewable resources, consumer cost, peak reduction), prediction of local generation and load patterns, and the assumptions concerning the operation of the ESS itself. This paper aims to quantify one of the usual assumptions made (especially by non-electrical engineers) i.e. that the assumption that the power converter in the ESS is 100% efficient does not lead to substantial errors in the ESS performance and cost-benefit analysis. Three different ESS power converter models have been created and their behaviour as part of a house based ESS management system over a one year period has been analysed using five different control approaches, a variety of battery and solar panel sizes and employing a time of use tariff (Economy 7). By observing the ESS charging pattern through the year and monitoring of the annual electricity cost along with the system’s losses for the household, relationships between the battery and PV size, the control algorithms, the electricity cost and the system losses were created

    Model of Centauro and strangelet production in heavy ion collisions

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    We discuss the phenomenological model of Centauro event production in relativistic nucleus-nucleus collisions. This model makes quantitative predictions for kinematic observables, baryon number and mass of the Centauro fireball and its decay products. Centauros decay mainly to nucleons, strange hyperons and possibly strangelets. Simulations of Centauro events for the CASTOR detector in Pb-Pb collisions at LHC energies are performed. The signatures of these events are discussed in detail.Comment: 19 pages, LaTeX+revtex4, 14 eps-figures and 3 table

    Physics at Very Small Angles with CASTOR at CMS

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    CASTOR is a small (56 cm diameter) quartz-tungsten Cerenkov calorimeter covering the small angles 0.2-0.6 deg (5.2<="eta"<=6.4) in CMS, a major experiment at the LHC. Particularly with heavy-ion reactions a substantial fraction of the total reaction energy goes into this large "eta" region. CASTOR will function as a part of CMS and also as an independent detector to search for special types of events in the far-forward region. It is divided into 16 azimuthal sectors, each with 18 longitudinal segments to allow identification of particles by their energy-loss profiles. The most forward segments are smaller to better characterize electromagnetic events

    Being a member of an energy community: assessing the financial benefits for end-users and management authority

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    Since 2011, in the context of sustainable development, UK government has been encouraging individuals to work as groups, and now, more than 5,000 community led projects are sprouted across the country, since more than 50% of the UK citizens had expressed their interest to get involved with energy communities if they can potentially reduce their electricity cost. The aim of this study is to quantify the financial benefits for end-users and energy management authority when an energy community is settled up. By simulating possible operating scenarios and by observing and assuming a cost effective power flow/exchange between the individuals, the communal energy storage and the power grid, the finances of each scenario were quantified. Consequently, the electricity cost for the end-users and the incomes for the management authority were monitored and the most financially suitable community energy storage along with the PV penetration were identified

    Sleep alterations in the course of aging environmental inputs

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    My research projects include the investigation of effects of different environmental factors on sleep and the circadian clock in the course of aging (such as light levels, exercise, diet and pharmacological substances including caffeine and diazepam). Investigating thebeneficial or adverse effects in the course of aging provides significant insights that could accelerate, hinder or ameliorate parts of the aging process allowing for a healthier and longer life span.Chronic consupmtion of high-caloric diet, eventually leading to obesity, alters the sleep homeostasis as well as the sleep architecture denoting a potentially enhanced aging phenotype.In addition to dietary preferences, light levels particularly at night significantly affect sleep and the sleep electroencephalogram across a wide age span, impactingthe sleep regulatory system as well as the brain integrity.Factors that induce beneficial effects include exercise and caffeine intake. Long-term exercise was able to lead to a younger brain phenotype across all ages while caffeine generally ameliorated sleep health.LUMC / Geneeskund

    Light particle spectra from 35 MeV/nucleon 12C-induced reactions on 197Au

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    Energy spectra for p, d, t, 3He, 4He, and 6He from the reaction 12C+197Au at 35 MeV/nucleon are presented. A common intermediate rapidity source is identified using a moving source fit to the spectra that yields cross sections which are compared to analogous data at other bombarding energies and to several different models. The excitation function of the composite to proton ratios is compared with quantum statistical, hydrodynamic, and thermal models

    Establishment of performance-based seismic design factors for precast concrete floor diaphragms

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    This paper presents an analytical study used to establish design factors for a new seismic design methodology for precast concrete floor diaphragms. The design factors include diaphragm force amplification factors Ψ and diaphragm shear overstrength factors Ωv

    Revisiting UV/optical continuum time lags in AGN

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    In this paper, we present an updated version of our model (KYNXiltr) which considers thermal reverberation of a standard Novikov-Thorne accretion disc illuminated by an X-ray point-like source. Previously, the model considered only two cases of black hole spins, and assumed a colour correction factor fcol=2.4f_{\rm col} = 2.4. Now, we extend the model to any spin value and colour correction. In addition, we consider two scenarios of powering the X-ray corona, either via accretion, or external to the accretion disc. We use KYNXiltr to fit the observed time lags obtained from intense monitoring of four local Seyfert galaxies (NGC 5548, NGC 4395, Mrk 817, and Fairall 9). We consider various combinations of black hole spin, colour correction, corona height, and fraction of accretion power transferred to the corona. The model fits well the overall time-lags spectrum in these sources (for a large parameter space). For NGC 4593 only, we detect a significant excess of delays in the U-band. The contribution of the diffuse BLR emission in the time-lags spectrum of this source is significant. It is possible to reduce the large best-fitting parameter space by combining the results with additional information, such as the observed Eddington ratio and average X-ray luminosity. We also provide an update to the analytic expression provided by Kammoun et al., for an X-ray source that is not powered by the accretion process, which can be used for any value of colour correction, and for two values of the black hole spin (0 and 0.998).Comment: Accepted for publication in MNRA