Sistemi tecnologici innovativi di involucro per il recupero del patrimonio edilizio recente. L'edilizia scolastica nel Comune di Bologna

La ricerca è volta a presentare un nuovo approccio integrato, a supporto di operatori e progettisti, per la gestione dell’intero processo progettuale di interventi di riqualificazione energetica e architettonica del patrimonio edilizio recente, mediante l’impiego di soluzioni tecnologiche innovative di involucro edilizio. Lo studio richiede necessariamente l’acquisizione di un repertorio selezionato di sistemi costruttivi di involucro, come base di partenza per l’elaborazione di soluzioni progettuali di recupero delle scuole appartenenti al secondo dopoguerra, in conglomerato cementizio armato, prevalentemente prefabbricate. Il progetto individua procedimenti costruttivi ecocompatibili per la progettazione di componenti prefabbricati di involucro “attivo”, adattabile ed efficiente, da assemblare a secco, nel rispetto dei requisiti prestazionali richiesti dalle attuali normative. La ricerca è finalizzata alla gestione dell’intero processo, supportato da sistemi di rilevazione geometrica, collegati a software di programmazione parametrica per la modellazione di superfici adattabili alla morfologia dei fabbricati oggetto di intervento. Tali strumenti informatizzati CAD-CAM sono connessi a macchine a controllo numerico CNC per la produzione industrializzata degli elementi costruttivi “su misura”. A titolo esemplificativo dell’approccio innovativo proposto, si formulano due possibili soluzioni di involucro in linea con i paradigmi della ricerca, nel rispetto dei principi di sostenibilità, intesa come modularità, rapidità di posa, reversibilità, recupero e riciclo di materiali. In particolare, le soluzioni innovative sono accomunate dall’applicazione di una tecnica basata sull’assemblaggio di elementi prefabbricati, dall’adozione di una trama esagonale per la tassellazione della nuova superficie di facciata, e dall’utilizzo del medesimo materiale termico isolante, plastico e inorganico, riciclato ed ecosostenibile, a basso impatto ambientale (AAM - Alkali Activated Materials). Le soluzioni progettuali proposte, sviluppate presso le due sedi coinvolte nella cotutela (Università di Bologna, Université Paris-Est) sono affrontate secondo un protocollo scientifico che prevede: progettazione del sistema costruttivo, analisi meccanica e termica, sperimentazione costruttiva, verifica delle tecniche di messa in opera e dei requisiti prestazionali.

Evaluation of alkali flooding combined with intermittent flow in carbonate reservoir

The majority of carbonate reservoir is oil-wet, which is an unfavorable condition for oil production. Generally, the total oil recovery after both primary and secondary recovery in an oil-wet reservoir is low. The amount of producible oil by enhanced oil recovery techniques is still large. Alkali substances are proven to be able to reverse rock wettability from oil-wet to water-wet, which is a favorable condition for oil production. However, the wettability reversal mechanism would require a noneconomical aging period to reach the maximum reversal condition. An intermittent flow with the optimum pausing period is then combined with alkali flooding (combination technique) to increase the wettability reversal mechanism and as a consequence, oil recovery is improved. The aims of this study are to evaluate the efficiency of the combination technique and to study the parameters that affect this method. In order to implement alkali flooding, reservoir rock and fluid properties were gathered, e.g. interfacial tension of fluids, rock wettability, etc. The flooding efficiency curves are obtained from core flooding and used as a major criterion for evaluation the performance of technique. The combination technique improves oil recovery when the alkali concentration is lower than 1% wt. (where the wettability reversal mechanism is dominant). The soap plug (that appears when high alkali concentration is used) is absent in this combination as seen from no drop of production rate. Moreover, the use of low alkali concentration limits alkali loss. This combination probably improves oil recovery also in the fractured carbonate reservoirs in which oil is uneconomically produced. The results from the current study indicate that the combination technique is an option that can improve the production of carbonate reservoirs. And a less quantity of alkali is consumed in the process.

p300/CBP tyrosine phosphorylation in response to dna damage activated by c-Abl tyrosine kinase

The nuclear signaling that is triggered in response to DNA damage entails the recruitment and assembly of repair proteins and the induction of genes involved in the activation of cell cycle checkpoint, apoptosis or senescence. The extensive changes in chromatin structure underlying these processes suggest that chromatin-modifying enzymes could be relevant targets of DNA damage-activated signaling. The acetyltransferases p300 and CBP participate in DNA damage-activated responses, including local histone hyperacetylation, cell cycle regulation, and co-activation of DNA damage activated proteins, such as p53, p73 and BRCA1. However, the link between DNA damage and p300/CBP activation has not been identified.We have detected p300 tyrosine phosphorylation in response to DNA damage. We show that the DNA damage-activated cAbl tyrosine kinase enters the nuclei of cells exposed to genotoxic agents and phosphorylates p300 on a tyrosine residue within the bromodomain that is conserved in p300, CBP and many other bromodomain-containing proteins. Antibodies against tyrosine phosphorylated p300/CBP show a DNA damage-inducible nuclear staining, suggesting that p300 tyrosine phosphorylation is an event linking DNA damage and chromatin modifications.

Biomass Gasification - Process analysis and dimensioning aspects for downdraft units and gas cleaning lines

In such territories where food production is mostly scattered in several small / medium size or even domestic farms, a lot of heterogeneous residues are produced yearly, since farmers usually carry out different activities in their properties. The amount and composition of farm residues, therefore, widely change during year, according to the single production process periodically achieved. Coupling high efficiency micro-cogeneration energy units with easy handling biomass conversion equipments, suitable to treat different materials, would provide many important advantages to the farmers and to the community as well, so that the increase in feedstock flexibility of gasification units is nowadays seen as a further paramount step towards their wide spreading in rural areas and as a real necessity for their utilization at small scale. Two main research topics were thought to be of main concern at this purpose, and they were therefore discussed in this work: the investigation of fuels properties impact on gasification process development and the technical feasibility of small scale gasification units integration with cogeneration systems. According to these two main aspects, the present work was thus divided in two main parts. The first one is focused on the biomass gasification process, that was investigated in its theoretical aspects and then analytically modelled in order to simulate thermo-chemical conversion of different biomass fuels, such as wood (park waste wood and softwood), wheat straw, sewage sludge and refuse derived fuels. The main idea is to correlate the results of reactor design procedures with the physical properties of biomasses and the corresponding working conditions of gasifiers (temperature profile, above all), in order to point out the main differences which prevent the use of the same conversion unit for different materials. At this scope, a gasification kinetic free model was initially developed in Excel sheets, considering different values of air to biomass ratio and the downdraft gasification technology as particular examined application. The differences in syngas production and working conditions (process temperatures, above all) among the considered fuels were tried to be connected to some biomass properties, such elementary composition, ash and water contents. The novelty of this analytical approach was the use of kinetic constants ratio in order to determine oxygen distribution among the different oxidation reactions (regarding volatile matter only) while equilibrium of water gas shift reaction was considered in gasification zone, by which the energy and mass balances involved in the process algorithm were linked together, as well. Moreover, the main advantage of this analytical tool is the easiness by which the input data corresponding to the particular biomass materials can be inserted into the model, so that a rapid evaluation on their own thermo-chemical conversion properties is possible to be obtained, mainly based on their chemical composition A good conformity of the model results with the other literature and experimental data was detected for almost all the considered materials (except for refuse derived fuels, because of their unfitting chemical composition with the model assumptions). Successively, a dimensioning procedure for open core downdraft gasifiers was set up, by the analysis on the fundamental thermo-physical and thermo-chemical mechanisms which are supposed to regulate the main solid conversion steps involved in the gasification process. Gasification units were schematically subdivided in four reaction zones, respectively corresponding to biomass heating, solids drying, pyrolysis and char gasification processes, and the time required for the full development of each of these steps was correlated to the kinetics rates (for pyrolysis and char gasification processes only) and to the heat and mass transfer phenomena from gas to solid phase. On the basis of this analysis and according to the kinetic free model results and biomass physical properties (particles size, above all) it was achieved that for all the considered materials char gasification step is kinetically limited and therefore temperature is the main working parameter controlling this step. Solids drying is mainly regulated by heat transfer from bulk gas to the inner layers of particles and the corresponding time especially depends on particle size. Biomass heating is almost totally achieved by the radiative heat transfer from the hot walls of reactor to the bed of material. For pyrolysis, instead, working temperature, particles size and the same nature of biomass (through its own pyrolysis heat) have all comparable weights on the process development, so that the corresponding time can be differently depending on one of these factors according to the particular fuel is gasified and the particular conditions are established inside the gasifier. The same analysis also led to the estimation of reaction zone volumes for each biomass fuel, so as a comparison among the dimensions of the differently fed gasification units was finally accomplished. Each biomass material showed a different volumes distribution, so that any dimensioned gasification unit does not seem to be suitable for more than one biomass species. Nevertheless, since reactors diameters were found out quite similar for all the examined materials, it could be envisaged to design a single units for all of them by adopting the largest diameter and by combining together the maximum heights of each reaction zone, as they were calculated for the different biomasses. A total height of gasifier as around 2400mm would be obtained in this case. Besides, by arranging air injecting nozzles at different levels along the reactor, gasification zone could be properly set up according to the particular material is in turn gasified. Finally, since gasification and pyrolysis times were found to considerably change according to even short temperature variations, it could be also envisaged to regulate air feeding rate for each gasified material (which process temperatures depend on), so as the available reactor volumes would be suitable for the complete development of solid conversion in each case, without even changing fluid dynamics behaviour of the unit as well as air/biomass ratio in noticeable measure. The second part of this work dealt with the gas cleaning systems to be adopted downstream the gasifiers in order to run high efficiency CHP units (i.e. internal engines and micro-turbines). Especially in the case multi–fuel gasifiers are assumed to be used, weightier gas cleaning lines need to be envisaged in order to reach the standard gas quality degree required to fuel cogeneration units. Indeed, as the more heterogeneous feed to the gasification unit, several contaminant species can simultaneously be present in the exit gas stream and, as a consequence, suitable gas cleaning systems have to be designed. In this work, an overall study on gas cleaning lines assessment is carried out. Differently from the other research efforts carried out in the same field, the main scope is to define general arrangements for gas cleaning lines suitable to remove several contaminants from the gas stream, independently on the feedstock material and the energy plant size The gas contaminant species taken into account in this analysis were: particulate, tars, sulphur (in H2S form), alkali metals, nitrogen (in NH3 form) and acid gases (in HCl form). For each of these species, alternative cleaning devices were designed according to three different plant sizes, respectively corresponding with 8Nm3/h, 125Nm3/h and 350Nm3/h gas flows. Their performances were examined on the basis of their optimal working conditions (efficiency, temperature and pressure drops, above all) and their own consumption of energy and materials. Successively, the designed units were combined together in different overall gas cleaning line arrangements, paths, by following some technical constraints which were mainly determined from the same performance analysis on the cleaning units and from the presumable synergic effects by contaminants on the right working of some of them (filters clogging, catalysts deactivation, etc.). One of the main issues to be stated in paths design accomplishment was the tars removal from the gas stream, preventing filters plugging and/or line pipes clogging At this scope, a catalytic tars cracking unit was envisaged as the only solution to be adopted, and, therefore, a catalytic material which is able to work at relatively low temperatures was chosen. Nevertheless, a rapid drop in tars cracking efficiency was also estimated for this same material, so that an high frequency of catalysts regeneration and a consequent relevant air consumption for this operation were calculated in all of the cases. Other difficulties had to be overcome in the abatement of alkali metals, which condense at temperatures lower than tars, but they also need to be removed in the first sections of gas cleaning line in order to avoid corrosion of materials. In this case a dry scrubber technology was envisaged, by using the same fine particles filter units and by choosing for them corrosion resistant materials, like ceramic ones. Besides these two solutions which seem to be unavoidable in gas cleaning line design, high temperature gas cleaning lines were not possible to be achieved for the two larger plant sizes, as well. Indeed, as the use of temperature control devices was precluded in the adopted design procedure, ammonia partial oxidation units (as the only considered methods for the abatement of ammonia at high temperature) were not suitable for the large scale units, because of the high increase of reactors temperature by the exothermic reactions involved in the process. In spite of these limitations, yet, overall arrangements for each considered plant size were finally designed, so that the possibility to clean the gas up to the required standard degree was technically demonstrated, even in the case several contaminants are simultaneously present in the gas stream. Moreover, all the possible paths defined for the different plant sizes were compared each others on the basis of some defined operational parameters, among which total pressure drops, total energy losses, number of units and secondary materials consumption. On the basis of this analysis, dry gas cleaning methods proved preferable to the ones including water scrubber technology in al of the cases, especially because of the high water consumption provided by water scrubber units in ammonia adsorption process. This result is yet connected to the possibility to use activated carbon units for ammonia removal and Nahcolite adsorber for chloride acid. The very high efficiency of this latter material is also remarkable. Finally, as an estimation of the overall energy loss pertaining the gas cleaning process, the total enthalpy losses estimated for the three plant sizes were compared with the respective gas streams energy contents, these latter obtained on the basis of low heating value of gas only. This overall study on gas cleaning systems is thus proposed as an analytical tool by which different gas cleaning line configurations can be evaluated, according to the particular practical application they are adopted for and the size of cogeneration unit they are connected to.

An advanced analytical study on linseed oil paint binder

Drying oils, and in particular linseed oil, were the most common binding media employed in painting between XVI and XIX centuries. Artists usually operated some pre-treatments on the oils to obtain binders with modified properties, such as different handling qualities or colour. Oil processing has a key role on the subsequent ageing of and degradation of linseed oil paints. In this thesis a multi-analytical approach was adopted to investigate the drying, polymerization and oxidative degradation of the linseed oil paints. In particular, thermogravimetry analysis (TGA), yielding information on the macromolecular scale, were compared with gas-chromatography mass-spectrometry (GC-MS) and direct exposure mass spectrometry (DEMS) providing information on the molecular scale. The study was performed on linseed oils and paint reconstructions prepared according to an accurate historical description of the painting techniques of the 19th century. TGA revealed that during ageing the molecular weight of the oils changes and that higher molecular weight fractions formed. TGA proved to be an excellent tool to compare the oils and paint reconstructions. This technique is able to highlight the different physical behaviour of oils that were processed using different methods and of paint layers on the basis of the different processed oil and /or the pigment used. GC/MS and DE-MS were used to characterise the soluble and non-polymeric fraction of the oils and paint reconstructions. GC/MS allowed us to calculate the ratios of palmitic to stearic acid (P/S), and azelaic to palmitic acid (A/P) and to evaluate effects produced by oil pre-treatments and the presence of different pigments. This helps to understand the role of the pre-treatments and of the pigments on the oxidative degradation undergone by siccative oils during ageing. DE-MS enabled the various molecular weight fractions of the samples to be simultaneously studied, and thus helped to highlight the presence of oxidation and hydrolysis reactions, and the formation of carboxylates that occur during ageing and with the changing of the oil pre-treatments and the pigments. The combination of thermal analysis with molecular techniques such as GC-MS, DEMS and FTIR enabled a model to be developed, for unravelling some crucial issues: 1) how oil pre-treatments produce binders with different physical-chemical qualities, and how this can influence the ageing of an oil paint film; 2) which is the role of the interaction between oil and pigments in the ageing and degradation process.

Reactivity of activated electrophiles and nucleophiles: labile intermediates and properties of the reaction products

The main topic of my Ph.D. thesis is the study of nucleophilic and electrophilic aromatic substitution reaction, in particular from a mechanistic point of view. The research was mainly focused on the reactivity of superactivated aromatic systems. In spite of their high reactivity (hence the high reaction’s rate), we were able to identify and in some case to isolate -complexes until now only hypothesized. For example, interesting results comes from the study of the protonation of the supernucleophiles tris(dialkylamino)benzenes. However, the best result obtained in this field was the isolation and structural characterization of the first stables zwitterionic Wheland-Meisenheimer complexes by using 2,4-dipyrrolidine-1,3-thiazole as supernucleophile and 4,6-dinitrobenzofuroxan or 4,6-dinitrotetrazolepyridine as superelectrophile. These reactions were also studied by means of computational chemistry, which allowed us to better investigate on the energetic and properties of the reactions and reactants studied. We also discovered, in some case fortuitously, some relevant properties and application of the compounds we synthesized, such as fluorescence in solid state and nanoparticles, or textile dyeing. We decided to investigate all these findings also by collaborating with other research groups. During a period in the “Laboratoire de Structure et Réactivité des Systèmes Moléculaires Complexes-SRSMC, Université de Lorraine et CNRS, France, I carried out computational studies on new iron complexes for the use as dyes in Dye Sensitized Solar Cells (DSSC). Furthermore, thanks to this new expertise, I was involved in a collaboration for the study of the ligands’ interaction in biological systems. A collaboration with University of Urbino allowed us to investigate on the reactivity of 1,2-diaza-1,3-dienes toward nucleophiles such as amino and phosphine derivatives, which led to the synthesis of new products some of which are 6 or 7 member heterocycles containing both phosphorus and nitrogen atoms.