102,330 research outputs found

    Are you sitting comfortably? The political economy of the body

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    The aim of this paper is to examine the relationship between the mass production of furniture in modern industrial societies and lower back pain (LBP). The latter has proven to be a major cost to health services and private industry throughout the industrialised world and now represents a global health issue as recent WHO reports on obesity and LBP reveal. Thus far there have been few co-ordinated attempts to deal with the causes of the problem through public policy. Drawing upon a range of sources in anthropology, health studies, politics and economics, the paper argues that this a modern social problem rooted in the contingent conjuncture of natural and social causal mechanisms. The key question it raises is: what are the appropriate mechanisms for addressing this problem? This paper develops an analysis rooted in libertarian social theory and argues that both the state and the capitalist market are flawed mechanisms for resolving this problem. There remains a fundamental dilemma for libertarians, however. Whilst the state and the market may well be flawed mechanisms, they are the dominant ones shaping global political economy. To what extent can libertarians work within these structures and remain committed to libertarian goals

    Influence of the equivalent electric load strategy on energy demand forecasting

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    In recent years, interest in artificial intelligence has been increasing in the energy sector, with the aim of improving efficiency and decreasing overall consumption. Innovative methods such as pattern recognition, artificial neural networks or other machine learning methods are being investigated to improve the accuracy of forecasting. Moreover, a suitable operation strategy may improve the efficiency of energy systems. The electric equivalent load is an operation strategy proposed for systems where electricity and heat (or cooling) are requested simultaneously, and there is equipment such as a heat pump to cover the heating (or cooling) load. In this paper, the electric equivalent load is defined to cover both the electricity request of the user and the electricity consumption of the heat pump. Thus, the energy system follows the electric equivalent load to cover both electricity and heating/cooling requests. This study aims to analyse how the accuracy varies when forecasting energy requests (e.g. electricity and heat) separately with respect to forecasting directly the electric equivalent load. The results show that electric equivalent load forecasting averages the accuracy of electricity and heat, improving the operation system by decreasing the electricity demand from the grid and increasing energy production during peak hours

    Heating Industrial Buildings with Heat Pump Air Systems: Is It Always the Most Advantageous Option?

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    According to extant Italian legislation implementing the Renewable Energy Directive, the mandatory renewable quota for a new building is 60% referring to a single service (e.g., heating during winter) or to multiple services (e.g., heating during winter and air conditioning during summer), depending on which services are actually present. The obligation to satisfy this minimum value often leads heating and ventilation plant designers to provide heat pump systems in industrial buildings, typically air/water or direct expansion type coupled with air terminals (air heaters or ventilation units) or radiant floors. The question is: Is this always the most advantageous option for industrial buildings? A typical industrial building was modeled by Trnsys® in two different climates. Based on the calculated thermal heating loads, the condensing radiant tubes and heat pump coupled with the air heaters systems were analyzed through dynamic simulation, evaluating their performance from an energy, environmental impact, and economic point of view. The analysis carried out revealed that a heat pump system is not always the most advantageous solution depending on the climate, the characteristics of the building (less or more thermal insulation, which corresponds to existing buildings rather than new ones), and the size of the photovoltaics system eventually installed on the roof

    An innovative approach to design cogeneration systems based on big data analysis and use of clustering methods

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    In recent years, collecting energy consumption data is becoming easier and easier thanks to decreasing of cost of smart sensors. Moreover, capacity of analysis data using big data methods like machine learning and artificial intelligence is increasing. Such methods are expected to be useful to increase efficiency of energy systems. In this paper an innovative approach to design cogeneration systems based on big data analysis is developed. More specifically, a study on how cluster analysis could be applied to analyse energy consumption data is depicted. The aim of the method is to design cogeneration systems that suit more efficiently energy demand profiles, choosing the correct type of cogeneration technology, operation strategy and, if they are necessary, energy storages. In the first part of the paper, the methodology based on clustering to perform the analysis of the dataset is described. In the second part, a case study with cogenerators (a wood industry that requires low temperature heat to dry wood into steam-powered kilns) is analysed. An alternative cogeneration system is designed and proposed. Thermodynamics benchmarks are defined to evaluate differences between as-is and alternative scenarios. Results show that the proposed innovative method allows to choose a more suitable cogeneration technology compared to the adopted one, giving suggestions on the operation strategy in order to decrease energy losses and, consequently, primary energy consumption

    Reversible Heat Pump Coupled with Ground Ice Storage for Annual Air Conditioning: An Energy Analysis

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    During annual operation, a heat pump produces both heating and cooling effects, so it would be of great advantage to store one of the two to be then used when it is necessary. To do this, a seasonal energy storage is necessary. This paper presents results relative to the use of a ground ice thermal energy storage (I-TES) integrated with a reversible heat pump for annual air conditioning. The energy analysis is based on heating and cooling loads for a residential building located in Milan. In particular, the focus is on the most important parameters affecting the performance of both the whole system and the Ice Tank, which is the position and the thickness of the insulation layers and the shape of the ice tank. A biannual simulation of the system allows for a full description of the ice tank behavior during the charging and discharging processes. The main objective of the study is to suggest a first tentative procedure to design the I-TES integrated system with the best energy performance

    On the possibility of extending the Noro-Frenkel generalized law of correspondent states to nonisotropic patchy interactions

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    Colloidal systems (and protein solutions) are often characterized by attractive interactions whose ranges are much smaller than the particle size. When this is the case and the interaction is spherical, systems obey a generalized law of correspondent states (GLCS), first proposed by Noro and Frenkel (Noro, M. G.; Frenkel, D. J. Chem. Phys. 2000, 113, 2941). The thermodynamic properties become insensitive to the details of the potential, depending only on the value of the second virial coefficient B2 and the density ρ. The GLCS does not generically hold for the case of nonspherical potentials. In this Letter, we suggest that when particles interact via short-ranged small-angular amplitude patchy interactions (so that the condition of only one bond per patch is fulfilled), it is still possible to generalize the GLCS close to the liquid-gas critical point. © 2007 American Chemical Society.GR-F
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