846 research outputs found
Análise comparativa de modelos para estimativa de índices obtidos a partir de imagens de satélite.
Taming Strategy Logic: Non-Recurrent Fragments
Strategy Logic (SL for short) is one of the prominent languages for reasoning about the strategic abilities of agents in a multi-agent setting. This logic extends LTL with first-order quantifiers over the agent strategies and encompasses other formalisms, such as ATL* and CTL*. The model-checking problem for SL and several of its fragments have been extensively studied. On the other hand, the picture is much less clear on the satisfiability front, where the problem is undecidable for the full logic. In this work, we study two fragments of One-Goal SL, where the nesting of sentences within temporal operators is constrained. We show that the satisfiability problem for these logics, and for the corresponding fragments of ATL* and CTL*, is ExpSpace and PSpace-complete, respectively
Fractionnement et caractérisation des lixiviats de centres d'enfouissement technique de déchets ménagers: intérêt de la chromatographie liquide haute performance sur le gel d'exclusion stérique
L'ultrafiltration et la chromatographie d'exclusion stérique haute performance sont utilisées pour la séparation et la caractérisation des composés organiques présents dans les lixiviats de centres d'enfouissement technique de déchets ménagers. Le fractionnement de la matière organique est obtenu sur des colonnes type TSK PW, en élution eau pH 4 et eau-méthanol. La spectroscopie en UV-visible et en fluorescence, un détecteur évaporatif à diffusion de lumière sont utilisés pour la caractérisation des fractions. Cette méthode rapide de séparation associée à une multidétection permet une mise en évidence, dans les fractions issues de l'ultrafiltration, de composés organiques caractéristiques. Dans la fraction de poids moléculaires inférieurs à 1000 Daltons, trois familles sont détectées. Les substances humiques et les protéines sont les principaux groupes présents dans la fraction de poids moléculaires supérieurs à 10000 Daltons.Landfill leachates represent a source of organic pollution characterized by an important organic load, with high chemical oxygen demand in recent sanitary landfills and some organic compounds refractory to biodegradation. Several researchers have examined the organic matter in these landfill leachates. In addition to measuring parameters such as chemical and biological oxygen demands (COD and BOD) and UV-absorbance, different analytical techniques were applied: gas chromatography with flame ionization or mass detection; high performance liquid chromatography; infrared spectroscopy; nuclear magnetic resonance spectrometry; and elementary analysis. Raw leachates or samples after fractionation on Sephadex gel were characterized by ultrafiltration or adsorption on XAD resins.Conclusions from these earlier studies were as follows: - physico-chemical properties of leachates revealed not only a high organic pollution but also diversity and variability according to the age of the sanitary landfill and the climatic conditions; - gel permeation chromatography and ultrafiltration revealed two main fractions in the leachates: one with molecular weights below 1000 Daltons (Da), and another with molecular weights above 5000-10000 Da; - infrared spectroscopy and nuclear magnetic resonance spectrometry showed functional groups present in the humic and fulvic acid fractions of natural organic matter; - a varying number of peaks detected by gas chromatography with flame ionization or mass detection proved the complexity of the matrix. Few compounds were identified and quantified, with the exception of fatty acids. Moreover this technique was only applicable to molecules with low molecular weight.The purpose of the present work was to develop a new method of fractionation of organic matter in landfill leachates and to study their characterization and treatment biodegradation. Ultrafiltration, as a prefractionation step, divided the leachate into four fractions according to their molecular weight: above 10000 Da, from 10000 - 3000 Da, from 3000 - 1000 Da, and below 1000 Da. The second fractionation step was carried out using gel permeation chromatography. This technique has been was applied by earlier researchers for the characterization of landfill leachates, but at low pressure on Sephadex gels. In our study, we developed a high performance size-exclusion chromatography method using a polymer based TSK PW column, a hydrophilic cross-linked polyether. Three TSK G3000 PW columns and one G5000 PW column were tested with water at pH 4 with acetic acid and with a water/methanol mixture as mobile phases. This rapid method of separation, with short retention times, was coupled with on-line multidetection: UV-visible (254 nm - aromatic compounds), fluorescence spectroscopy (275/325 nm, protein-type molecules; 320/430 nm, humic-type molecules) and evaporative light scattering detection, ELSD. The ELSD allowed detection of all mineral and organic compounds that did not evaporate at the working temperature (45°C).The effect of the sodium chloride concentration on retention times was tested with eluants and columns. Secondary effects, often observed with size-exclusion chromatography, occurred with the gel chosen. The elution of sodium chloride solutions at different concentrations showed that the TSK PW gel bears electronegative charges, and that the density of these charges differs from one column to another. For the leachate we observed this influence: chromatograms obtained on two TSK G3000 columns were different for fractions with molecular weights below 1000 Da.The comparison of chromatograms obtained with the four detection methods provided information about the identity of the types of compounds present. For fractions with molecular weights below 1000 Da, separation was performed using a TSK G3000 PW column, with an eluant pH of 4 and a water-methanol mixture; three main families were detected. For fractions with molecular weights above 10000 Da, chromatographic separation was improved by elution with water/methanol (70/30) with TSK G5000 and G3000 columns in series; two main groups were identified, humic substances and protein-type compounds. The constituents of the two intermediate fractions with molecular weights between 10000 and 1000 Da were essentially humic substances, identified after separation on a TSK G3000 PW column with water-methanol (70/30) as the eluant
Mg and its alloys for biomedical applications: Exploring corrosion and its interplay with mechanical failure
The future of biomaterial design will rely on temporary implant materials that degrade while tissues grow, releasing no toxic species during degradation and no residue after full regeneration of the targeted anatomic site. In this aspect, Mg and its alloys are receiving increasing attention because they allow both mechanical strength and biodegradability. Yet their use as biomedical implants is limited due to their poor corrosion resistance and the consequential mechanical integrity problems leading to corrosion assisted cracking. This review provides the reader with an overview of current biomaterials, their stringent mechanical and chemical requirements and the potential of Mg alloys to fulfil them. We provide insight into corrosion mechanisms of Mg and its alloys, the fundamentals and established models behind stress corrosion cracking and corrosion fatigue. We explain Mgs unique negative differential effect and approaches to describe it. Finally, we go into depth on corrosion improvements, reviewing literature on high purity Mg, on the effect of alloying elements and their tolerance levels, as well as research on surface treatments that allow to tune degradation kinetics. Bridging fundamentals aspects with current research activities in the field, this review intends to give a substantial overview for all interested readers; potential and current researchers and practitioners of the future not yet familiar with this promising material. © 2017 by the authors. Licensee MDPI, Basel, Switzerland
Recombinant 60-kda Heat Shock Protein From Paracoccidioides Brasiliensis: Is It A Good Antigen For Serological Diagnosis Of Paracoccidioidomycosis?
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Paracoccidioides brasiliensis and P. lutzii are fungi that cause paracoccidioidomycosis (PCM), the most prevalent systemic mycosis in South America. For serological diagnosis, although 43-kDa glycoprotein (gp43) is regarded as highly specific for PCM, the occurrence of false negative reactions in sera from patients infected with P. lutzii suggests that preparation with only one antigen is not recommended. Heat shock proteins are feasible alternatives as a second antigen because they are often highly immunogenic. In this study, we evaluated the usefulness of recombinant 60-kDa heat shock protein from P. brasiliensis (rPbHsp60) for the serological diagnosis of PCM. Using western blotting assay, we observed that 77.3% of the sera from PCM patients were positive to rPbHsp60, with 90.9% positivity to recombinant gp43 (rgp43). More importantly, sera from healthy subjects had 27% positivity to rPbHsp60 and none to rgp43. When rPbHsp60 was used in ELISA, we did not observe significant differences between the reactions with sera from PCM patients and healthy subjects, while the difference was clearly evident when the antigen was rgp43. Furthermore, rPbHsp60 was recognized by sera from patients with histoplasmosis, aspergillosis, sporotrichosis or tuberculosis in an ELISA test. These results show that rPbHsp60 is not a good antigen for PCM diagnosis.504Sao Paulo Research Foundation (FAPESP) [2013/12278-3]FAPESP [2012/07924-0, 2009/03235-3, 2012/08552-0]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
Capillary rising damp in Venetian context : state of the art and numerical simulation
The fragility of Venice and its buildings are linked to the floods, observed since
ancient times and emphasized in recent years: the periodic sea level rise, accompanied by rising
damp, are the main causes of the alteration. In particular, the rising damp causes a series of
complex diseases in the historic buildings, such as physical decay, chemical or biological, with
loss of aesthetic and economic value. In addition, greater heat dispersion and reduced thermal
comfort can also occur in interior spaces, with consequent risks for human health. This is a sign
of “Sick Building Syndrome”. It is very important to develop models for assessing the
vulnerability of assets and to manage sustainable plans related to maintenance processes and
activities, satisfying the requirements of effectiveness and compatibility.Basing on numerical
models performed with the WUFI 2D software, the paper analyses the different behavior of rising
damp in relation to materials or masonry structures. In particular, the construction techniques
and typical materials used in Venetian buildings were investigated, such as clay brick walls, lime
plaster, Marmorino and Cocciopesto, adopted mainly to limit the capillary rise also caused by
the phenomenon of “acqua alta”
Retrofit of an Historical Building toward NZEB
Abstract The European Directive on Energy Efficiency in Buildings (Directive 2010/31/EU) has introduced the need to transform buildings to nearly zero energy (NZEB) by 2020. Existing buildings represent the major part of the building stock and an interesting challenge is to transfer it toward NZEB. Energy retrofit is even more significant in Italy, where existing buildings stock (mainly residential) is also historic, so it's subject to environmental constraints or architectural-artistic value, and it's influenced by specific regulations and methods of intervention for refurbishment. In this case, the challenge becomes even more important and concerns both the building shell and the systems: retrofitting introduces not originally present in the complex; retrofit is not covered in the maintenance, since it represents an upgrade, an adaptation of the building, specifically in relation to energy efficiency, but also, by extension, other functions / features pertaining to the environment and sustainability. A case study of a radical refurbishment of an historical building is Ca' S. Orsola in Treviso. It is ruled by the Historical and Architectural Veneto Regional Authority. The building has been transformed into a prestigious residential complex by a major renovation that was aimed primarily seismic and energy upgrading. The energy and environmental performance of building have been analyzed by numerical simulation and experimental measurement in the EBC IEA Annex 56 [1] context with the aim to verify that intervention strategies respect to the reduction of energy consumption, the minimization of CO 2 emissions and maximizing the use of sources of renewable energy
Renewable hydrogen supply chains: A planning matrix and an agenda for future research
Worldwide, energy systems are experiencing a transition to more sustainable systems. According to the Hydrogen Roadmap Europe (FCH EU, 2019), hydrogen will play an important role in future energy systems due to its ability to support sustainability goals and will account for approximately 13% of the total energy mix in the coming future. Correct hydrogen supply chain (HSC) planning is therefore vital to enable a sustainable transition, in particular when hydrogen is produced by water electrolysis using electricity from renewable sources (renewable hydrogen). However, due to the operational characteristics of the renewable HSC, its planning is complicated. Renewable hydrogen supply can be diverse: Hydrogen can be produced de-centrally with renewables, such as wind and solar energy, or centrally by using electricity generated from a hydro power plant with a large volume. Similarly, demand for hydrogen can also be diverse, with many new applications, such as fuels for fuel cell electrical vehicles and electricity generation, feedstocks in industrial processes, and heating for buildings. The HSC consists of various stages (production, storage, distribution, and applications) in different forms, with strong interdependencies, which further increase HSC complexity. Finally, planning of an HSC depends on the status of hydrogen adoption and market development, and on how mature technologies are, and both factors are characterised by high uncertainties. Directly adapting the traditional approaches of supply chain (SC) planning for HSCs is insufficient. Therefore, in this study we develop a planning matrix with related planning tasks, leveraging a systematic literature review to cope with the characteristics of HSCs. We focus only on renewable hydrogen due to its relevance to the future low-carbon economy. Furthermore, we outline an agenda for future research, from the supply chain management perspective, in order to support renewable HSC development, considering the different phases of renewable HSCs adoption and market development
proposal of a methodology for achieving a leed o m certification in historic buildings
Abstract Nowadays resources are running out quickly, it's necessary to consider how the construction industry influences the environment using different materials and sources during all the building's life cycle. For this reason, in every transformation phases it's necessary to consider concepts as sustainability and green buildings. These are diffused from hundreds kind of green assessment tools, developed to measure sustainability goals in building sector and to compare the project with possible best practices or other green buildings. In this background, the rating system LEED (Leadership in Energy and Environmental Design) aims to examine and classify buildings according to energetic and environmental requirements. The particular LEED O+M (Building Operations and Maintenance) is developed for existing buildings undergoing improvement work or little to no construction and is based on the operative and management aspects. The certification process results, at a first analysis, hard to follow due to the complexity of internal parameters and the documentation required. The paper consists in a methodology and in an univocal work program of LEED O+M, trying to obtain the minimum requested certification score with optimization of the technical resources and documents. This methodology has application in a case study of historic building: the Ca' Rezzonico Museum, in the center of Venice
Cost-Optimal measures for renovation of existing school buildings towards nZEB
Abstract The energy policies of the European Union (EU) encourage the member states to convert building stock into nearly Zero-Energy Buildings (nZEB) and national public authorities to adopt exemplary actions. Directive 2010/31/EU (EPBD recast) introduces the concept of nZEB as a building that has a very high energy performance and its energy need is covered to a very significant extent by energy from renewable sources (RES). Moreover the Directive refers to the cost-optimal methodology for fixing building energy requirements. This paper presents the results of the application of the cost-optimal methodology in a couple of existing school buildings located in the North East of Italy. The analysed buildings are a primary and a secondary schools that differ in construction period, in compactness ratio, in buildings envelope materials and systems. Several combinations of retrofit measures have been applied in order to derive cost-effective efficient solutions for retrofitting according to the methodology proposed by the project Annex56 "Cost Effective Energy & CO2 Emissions Optimization in Building Renovation". The cost-optimal level has been identified for each building and the best performing solutions have been selected considering a financial analysis and the application of "Conto Termico 2.0" government incentives. The results show the suitability of the proposed methodology to assess cost-optimality and energy efficiency in school building refurbishment. Moreover, this study shows different possibility providing the most cost-effective balance between costs and energy saving
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