1,618 research outputs found
Nearly Zero Energy multi-functional Buildings - Energy and Economic evaluations
Building energy renovation is one of the pillars upon which the 2050 European low-carbon goals are based. Simultaneously, building energy renovation is widely recognized as the trump card for the new start of European economy. However, at present the renovation rate of the existing building is very low throughout Europe (approximately 1%) and investments in high performing buildings are generally mistrusted by stakeholders, due to their high capital costs.
In this context, this PhD thesis dedicated its efforts to investigate from the energy and financial perspective the consequences of buildings renovation in the European scene. Particularly, the research boundaries were delineated by focusing on non-residential, multi-functional buildings, that are nowadays poorly studied due to their heterogeneous nature.
In this view, the thesis’ contributions were addressed at three levels:
a) multi-functional buildings as archetypes to input in energy models for long-term energy analysis;
b) multi-functional buildings used to test the financial viability of energy efficiency projects, in view of reaching the nearly Zero Energy performance level. As these analyses necessarily require case studies, the attention was directed towards a specific type of multi-functional buildings, hotels;
c) multi-functional buildings as test-bed to assess the impact of co-benefits on the financial performances of energy efficiency projects. Once again, hotel buildings were selected for the development of the detailed analyses.
To include archetypes of multi-functional buildings in bottom-up building energy models, a new modelling method was proposed. The method provides a rationale for the classification of energy end-uses into typical and extra, so that the modeling problem is simplified and a coherent use of well-established Reference Buildings modelling methods is allowed.
Then, the focus of the research was narrowed to the hotel sector, which was found to lack of reliable energy performance benchmarks and effective performance-based greens labels. Case study buildings were object of energy and financial evaluations. On one side, real hotels were analyzed to test the application of the EU imposed cost-optimal methodology as a support tool to guide private investors’ investment decisions. On the other side, an Italian Reference Hotel was modelled and the cost-optimal methodology was applied to investigate the existing energy and financial gaps between cost-optimal and Nearly Zero Energy performance level in Italy. From both perspectives, findings converged to similar conclusions: high performing retrofit are not financially viable, if avoided energy costs are the only operational benefits accounted for.
Starting from these outcomes, the thesis investigated how valuation procedures could be exploited to make NZEB retrofit solutions appealing for private investors. Based on a literature review of the co-benefits of energy efficiency projects, 2 different strategies were pursued and tested on the Italian Reference Hotel. The first approach proposed to monetize co-benefits of energy efficiency interventions based on literature and to include them in the well-established cost-optimal methodology. Results highlighted that co-benefits related to the market appreciation of a retrofitted hotel can drastically change the perception of the financial convenience of an ambitious retrofit project. In the latter strategy, the issue of monetizing non-energy benefits was faced directly: a technique to value non-market goods was applied to monetize comfort. Findings proved that hotels guests’ willingness to pay for comfortable indoor conditions is higher than the hoteliers’ extra costs for providing them. Due to the context-dependent nature of co-benefits, the findings of the 2 applications do not represent generally applicable quantitative benchmarks. Nonetheless, they confirm the leading role that literature attribute to co-benefits in the success of energy efficiency projects
Public-Private health sector mix- way forward
The debate on Public-Private mix has been around in South Africa (SA) for the past ten years. The debate arose out of a realisation of the weaknesses in the public health parallel with the ever-increasing private sector worldwide. The concept has been referred to in different terminologies, public-private mix, public private partnerships (PPP), public private initiatives (PPI). This paper aims to stimulate further debate on the subject, in the light of changing policies and political thinking in the country. The paper presents findings and examples from other countries, based on a review of literature on the subject. The paper concludes that in SA there is a strong potential for public private mixing, but warns that the process should be carefully implemented. SA Fam Pract 2004;46(9): 5-
Evolution of magnetic fields and energetics of flares in active region 8210
To better understand eruptive events in the solar corona, we combine sequences of multi-wavelength observations and modelling of the coronal magnetic field of NOAA AR 8210, a highly flare-productive active region. From the photosphere to the corona, the observations give us information about the motion of magnetic elements (photospheric magnetograms), the location of flares (e.g., H, EUV or soft X-ray brightenings), and the type of events (H blueshift events). Assuming that the evolution of the coronal magnetic field above an active region can be described by successive equilibria, we follow in time the magnetic changes of the 3D nonlinear force-free (nlff) fields reconstructed from a time series of photospheric vector magnetograms. We apply this method to AR 8210 observed on May 1, 1998 between 17:00 UT and 21:40 UT. We identify two types of horizontal photospheric motions that can drive an eruption: a clockwise rotation of the sunspot, and a fast motion of an emerging polarity. The reconstructed nlff coronal fields give us a scenario of the confined flares observed in AR 8210: the slow sunspot rotation enables the occurence of flare by a reconnection process close to a separatrix surface whereas the fast motion is associated with small-scale reconnections but no detectable flaring activity. We also study the injection rates of magnetic energy, Poynting flux and relative magnetic helicity through the photosphere and into the corona. The injection of magnetic energy by transverse photospheric motions is found to be correlated with the storage of energy in the corona and then the release by flaring activity. The magnetic helicity derived from the magnetic field and the vector potential of the nlff configuration is computed in the coronal volume. The magnetic helicity evolution shows that AR 8210 is dominated by the mutual helicity between the closed and potential fields and not by the self helicity of the closed field which characterizes the twist of confined flux bundles. We conclude that for AR 8210 the complex topology is a more important factor than the twist in the eruption process
The influence of American economic policies on the business life of Puerto Rico.
Thesis (M.B.A)--Boston Universit
A laboratory guide in elementary biology with special reference to the biota of the West Indies
Thesis (M.A.)--Boston University This item was digitized by the Internet Archive
Here There Is No Plague : The Ideology and Phenomenology of AIDS in Gay Literature
This project considers the social movements, historical memory, and politics of health to trace the way the literature of the AIDS epidemic both documents and discloses the lived experiences of a community struggling in the midst of an epidemic. It focuses on the literature of AIDS, analyzing the underlying ideologies of AIDS and articulating a phenomenology of AIDS that goes beyond the feminist or queer ones already considered in current scholarship. I argue that the literature of AIDS reflects various ideological fantasies about AIDS that, depending on political preconceptions and ontologies of identity, must, out of necessity, exclude certain ideas in order for the fantasy to work. Through both Larry Kramer\u27s The Normal Heart and Tony Kushner\u27s Angels in America, I analyze how the ideological forces at work within the gay community are represented in the literature of the 1980s and 90s. My focus is on how, in the early days of the epidemic, these plays presented a specific ideological fantasy about AIDS, and my analysis identifies what things must be excluded or overlooked in order for the fantasies to properly function. Despite the extensive critical work focusing on the AIDS epidemic, there has not been a scholarly work that constructs a phenomenology of AIDS. And so, I move beyond current feminist and queer approaches to phenomenology to use Andrew Holleran\u27s novel The Beauty of Men and collection of essays Ground Zero to develop a phenomenology of AIDS. I argue that Holleran\u27s texts are less concerned with the political, historical, and ideological structures that brought about the AIDS epidemic and more concerned with how gay men lived within the disease---how they formed social/physical attachments to both people and places, and how their sensory experiences of the epidemic created their individual and collective subjectivities. The shared experience of AIDS becomes the foundation for the reemerging/restructuring gay subculture; in a phenomenological sense, the community gains an awareness/consciousness of who it is by examining more carefully what it no longer is. I conclude with an examination of 21 st century young adult gay fiction---specifically Boy Meets Boy by David Levithan and Hero by Perry Moore---and how they paint rosy portraitures of gay life beyond the coming out stage to the neglect of a complex sexuality that continuously redefines a queer individual\u27s place within the greater social, political, and cultural structure. Yet the presence---the memory---of AIDS looms over these texts, and the novels still contain the trace of what AIDS was/did to the gay community that came before them. By creating worlds without AIDS, these novels attempt to create a new version of a gay fantasia, one that counters the stark realities and oppressive ideological structures of the gay fantasia presented by Kushner in Angels in America.
Experiments on individual decision-making and information
This thesis is composed by three experiments that explore the role of information in individual
decision-making.
In Chapter 1 it is presented an experimental test of the contextual inference theory (Kamenica,2008). The experiment shows that the dimension of choice sets conveys payoff-relevant information in decision-making: even when options are not directly observable, the likelihood of finding an option that fits individual tastes can be inferred from the set size.
Information on the lenght of a product line is then shown to be relevant in individual decision making.
In Chapter 2 the decision-maker is presented with payoff irrelevant information: group-membership and others' behavior. The experiment test if and how these information affect individual decision of behaving ethically. The results provide evidence of the effectiveness of these information in shaping moral behavior.
Chapter 3 aims at going into the black box of information processing under uncertainty with an
eye-tracking experiment. The aim of this last chapter is to contribute to the understanding of the choice process under different dimensions of the choice sets (small and large), and its relation with the response time
Mathematical Modeling in Chemical Engineering: A Tool to Analyse Complex Systems
Mathematical modeling is an attempt to describe a slice of reality in mathematical terms.
In Chemical Engineering, mathematical modeling is used for simulation, control and optimization of a process and it is also a tool to design the industrial devices.
Mathematical modeling is a technique commonly in place also in both theoretical and experimental studies of chemical processes.
In the present chapter mathematical modelling applications to complex systems as a consequence of structure heterogeneity and involved various physical-chemical phenomena are presented. Particular attention will be focused on improving the quantitative understanding of the basic phenomena of a process that can come from the use of mathematical models.
Specific task is also demonstrating how, through the use of information coming from experimental investigations and simulations, it is possible checking on the validity of the assumptions made and fine tuning the predictive mathematical model capability.
The possibility of analyzing and quantifying the role played by each single step of the process is examined in order to define the relevant mathematical expressions. The latter allows getting useful indications about the impact of different operating conditions on the role of each single step and at the very end it gives indication about the efficiency of the process itself.
Next step focuses on the estimation of the significant parameters of the process. In complex systems the determination \u201ca priori\u201d of some parameters is not always feasible and they are therefore determined as a comparison of experimental and simulation data.
The final result is therefore the availability of a tool, the verified and validated (V&V) mathematical model, that can be used for simulation, process analysis, process control, optimization, design.
Specific reference will be made to the use of the proposed methodology on a system whose behaviour, on varying the agitation level, was quantified and validated against the results of an experimental investigation in a pilot plant.
A second application will allow to analyse the effect of transport phenomena in multi-phase heterogeneous systems in order to detect the conditions at which production plant efficiency is improved
Passivation of Grid-Following VSCs: A Comparison Between Active Damping and Multi-Sampled PWM
This article compares different strategies used to enhance the stability properties of grid-following voltage-source converters (VSCs). Because of digital delays, VSC admittance exhibits a nonpassive zone, which introduces negative damping and may destabilize the grid-connected operation. It is shown that typically used active damping (AD) strategies only bring positive impact up to a certain frequency, while deteriorating admittance properties around and above the Nyquist frequency. Multi-sampled pulsewidth modulation (MS-PWM) greatly extends the passive admittance region, using only a single-loop current controller. Experimental admittance measurements are performed on a single-phase VSC, up to twice the switching frequency. Subsequently, different grid-connected scenarios are tested to show that MS-PWM retains stable operation, where AD methods cause instability. This article also offers analytic modeling and experimental measurements of noise propagation for compared strategies. It is shown that derivative-based AD is not highly sensitive; however, MS-PWM offers additional noise suppression
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