1,721,320 research outputs found
Payoff for geothermal heat pumps using shallow ground heat exchangers
No full textA discounted cash flow analysis (DCFA) and a cost benefit analysis (CBA) have been implemented in order to nvestigate the economic aspects of ground coupled heat pump (GCHP) for space heating and cooling, in comparison to traditional condensing boiler (CB). The DCFA allows the analysis of investment costs, operating costs and savings of the two different systems in order to understand if the GCHP’s pay back periods (PBPs) period is more interesting than CB in coming years. The first financial model (DCFA) takes account for economic factors as prices, costs and growth, while the economic approach (CBA) include the carbon price into the calculation, considering the social costs of carbon dioxide emissions. The whole analysis is implemented adopting a parametric approach, in which all the economic terms are linked to energy labels, degree-days and energy mix ratios (EMRs), the latter obtained as ratio between the cost of electricity and natural gas paid by the householder. Relating to different EMRs, the PBPs are presented in matrixes in which energy labels and degree-days are the row/column variables, to confront the benefits of choosing between GSHP versus CB. The PBPs are also calculated with the introduction of the carbon price, so that some considerations about the environmental aspects are presented. The results show that all higher energy labels have a good profitability ratio between costs and payback periods and demonstrate that GCHP system does pay off
Economic performance of ground source heat pump: does it pay off?
No full textA DCF model (discounted cash flow model) is implemented in order to investigate the economic aspects of GSHP (ground source heat pump) for heating and cooling, in comparison to traditional CB (condensing boiler). The DCF model allows the analysis of investment costs, operating costs and revenues of the two different systems in order to understand if the GSHP outperform its conventional counterpart in coming years, explicitly taking account for factors as price/cost growth. The whole analysis is performed adopting a parametric approach, in which all the previous terms are linked to energy labels, degree-days and EMRs (Energy Mix Ratios), the latter obtained as ratio between the full unit cost of electricity and natural gas paid by the householder. Relating to different EMRs, the DPBPs (Discounted Pay Back Periods) are presented in decision support matrixes in which energy labels and degree-days are the row/column variables, to confront the benefits of choosing between GSHP versus CB. Some considerations are also presented in order to express the environmental aspects. The results show that all higher energy labels have a good profitability ratio between costs and payback periods and demonstrate that GSHP system does pay off. Lower labels become interesting when the EMR drops to 0,25 and the gas price goes up 0,70 €/Nm3
Analysis of building energy consumption through panel data: the role played by the economic drivers
No full textPolicy makers have realized that without significant increases in the energy efficiency and notable reductions
in the energy use of the household sector, it will be impossible to lower carbon dioxide emissions
and mitigate the risks of climate change at the global level. The energy demand in residential buildings is
influenced by several parameters, such as national economic growth, climate and weather, demographic
structure, and technological development. In this paper, we analyze the determinants of electricity and
natural gas consumptions in Italy during the period from 2004 to 2013. We provide estimates of price and
income elasticities of the demand for both the energy sources in the residential sector. The role played by
both energy price and household income is worth attention because it provides evidence for the occurrence
of the direct rebound effect. Therefore, the economic drivers of the energy demand are important
to improve the policies meant to reduce greenhouse gas emissions and contrast the global warming
Simplifying antiderivative antialiasing with lookup table integration
Full text linkAntiderivative Antialiasing (ADAA), has become a pivotal method for reducing aliasing when dealing with nonlinear function at audio rate. However, its implementation requires analytical computation of the antiderivative of the nonlinear function, which in practical cases can be challenging without a symbolic solver. Moreover, when the nonlinear function is given by measurements it must be approximated to get a symbolic description. In this paper, we propose a simple approach to ADAA for practical applications that employs numerical integration of lookup tables (LUTs) to approximate the antiderivative. This method eliminates the need for closed-form solutions, streamlining the ADAA implementation process in industrial applications. We analyze the trade-offs of this approach, highlighting its computational efficiency and ease of implementation while discussing the potential impact of numerical integration errors on aliasing performance. Experiments are conducted with static nonlinearities (tanh, a simple wavefolder and the Buchla 259 wavefolding circuit) and a stateful nonlinear system (the diode clipper)
Supramolecular catalysis by recognition-encoded oligomers: Discovery of a synthetic imine polymerase
No full textAll key chemical transformations in biology are catalysed by linear oligomers. Catalytic properties could be programmed into synthetic oligomers in the same way as they are programmed into proteins, and an example of the discovery of emergent catalytic properties in a synthetic oligomer is reported. Dynamic combinatorial chemistry experiments designed to study the templating of a recognition-encoded oligomer by the complementary sequence have uncovered an unexpected imine polymerase activity. Libraries of equilibrating imines were formed by coupling diamine linkers with monomer building blocks composed of dialdehydes functionalised with either a trifluoromethyl phenol (D) or phosphine oxide (A) H-bond recognition unit. However, addition of the AAA trimer to a mixture of the phenol dialdehyde and the diamine linker did not template the formation of the DDD oligo-imine. Instead, AAA was found to be a catalyst, leading to rapid formation of long oligomers of D. AAA catalysed a number of different imine formation reactions, but a complementary phenol recognition group on the aldehyde reaction partner is an essential requirement. Competitive inhibition by an unreactive phenol confirmed the role of H-bonding in substrate recognition. AAA accelerates the rate of imine formation in toluene by a factor of 20. The kinetic parameters for this enzyme-like catalysis are estimated as 1 × 10-3 s-1 for kcat and the dissociation constant for substrate binding is 300 μM. The corresponding DDD trimer was found to catalyse oligomerisation the phosphine oxide dialdehyde with the diamine linker, suggesting an important role for the backbone in catalysis. This unexpected imine polymerase activity in a duplex-forming synthetic oligomer suggests that there are many interesting processes to be discovered in the chemistry of synthetic recognition-encoded oligomers that will parallel those found in natural biopolymers. This journal i
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Retrofitting Hospitals: A Parametric Design Approach to Optimize Energy Efficiency
No full textDespite many progress have been done in the renovation of the existing stock, retrofitting hospitals and other strategic buildings still represent a very challenging issue both for their complex articulation and for the need to maintain acceptable operational level. The paper reports a research activity, run at the Department of Architecture in cooperation with S. Orsola Hospital in Bologna, aimed at investigating innovative strategies for retrofitting to meet the highest energy efficiency standards at national level. The main goal of the administration was to set a renovation plan-taking into account some limitations concerning the existing building features and the budget availabilities- A ble to remarkably reduce energy demand while creating the minimum disruption for end users. The starting position of the research was to preserve the historical image of the building while defining a strategy to insulate it from inside. The novelty of design approach lied in defining a basic working unit which was associated to the typical room of the stay division that was used to analyse the starting conditions (indoor comfort and environmental parameters) and simulate via software modelling the potential improvements. This led to define a step by step strategy that was translated into global intervention scenarios while the basic working unit was properly re-designed and validated. This approach allowed to define a parametric strategy able to predict the impacts of renovation on each floor, on each wing and on the system as a whole while assigning a specific unit cost and a reliable renovation timing
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