254 research outputs found
IMPLEMENTATION OF A GENETIC ALGORITHM FOR ENERGY DESIGN OPTIMIZATION OF LIVESTOCK HOUSING USING A DYNAMIC THERMAL SIMULATOR
No full textA Genetic Algorithm (GA) is an optimization process inspired to natural systems ability of surviving in many different environment through the mechanisms of natural selection and genetics. The pairing of GA-based optimization techniques with dynamic thermal models is a common and effective practice to find energy efficient design solutions.
In this paper a genetic algorithm with the ability to dialogue with a dynamic thermal model is implemented. The algorithm, coded in Matlab, works with populations of strings. Each string, that represent a complete design solution, is initially randomly generated by the GA and evaluated in terms of energy performances by the dynamic thermal simulator. A new population is then generated using three different GA stochastic operators, reproduction, crossover and mutation, by selecting, mixing and randomly modifying the fittest solutions of the previous generation. Each generation is evaluated by the thermal model and thus the fitness of the strings, that represent the energy efficiency of the design solutions, improves every cycle till eventually converge to the best solution. This whole methodology is well documented and applied in residential buildings design but can be easily extended to livestock housing. In this paper the algorithm is coded to be applied on a simple sheepfold model in order to optimize only passive design solutions
Optimization of thermal performances in livestock housing design solutions using Genetic Algorithms
No full textVarious design elements can affect the energy efficiency of buildings. Usually, parametric analysis doesn’t take into account the interactive effects between the different features in terms of building energy use. Genetic Algorithm (GA) based optimization approach relies on the evolutionary concept of natural selection to converge on an optimal solution and links together many parameters and several solutions. Many studies underline the effectiveness of coupling GA-based optimization techniques with dynamic thermal models in order to analyze energy efficiency design solutions. This methodology is well documented in residential buildings but so far few tries were made to extend this process to livestock housing and service facilities. In this paper, Genetic Algorithms are applied as an optimization tool to find suitable design solutions in terms of thermal performance. Initially, the GA generates a random population of design configurations, which are then evaluated using a dynamic thermal model to assess energy performances. The results from the simulations are used by the GA to generate, with an objective-oriented stochastic operator, a new set of possible configurations defined by better energy performances. Thus the algorithm guides the search, generation by generation, towards low-energy design solutions. The combined process is applied to a simple sheepfold model located in Mediterranean climate for a medium-size extensive enterprise. The study analyzes only passive design solutions, since livestock facilities, especially those serving extensive farming which are prevalent in Mediterranean areas, need low energy input to achieve thermal and lighting comfort, when an appropriate design of the building envelope and windows is adopted
L'erbario del Prof. Manlio Chiappini (1924-1998) in Herbarium CAG
No full textThe herbarium of Chiappini, held in Herbarium CAG of Cagliari University, is presented. Prof. Manlio Chiappini, who dead the 4th of january 1998, teached Botany at the Athenaeum of Cagliari from 1965 to 1987 and from 1965 to 1986 he was director of Botanical Institute and Botanical gardens of Cagliari University. From a research carried out in Herbarium CAG is shown that Chiappini’s herbarium is compound of 1262 exsiccata, referred to 630 specific and subspecific entities (about the 30% of Sardinian flora), of which 45 referred to endemic species (about the 20% of Sardinian flora) and that the Museum Herbarium CAG itself is depositary of a number of 4 species pointed out, by the Author himself, for the first time to Sardinia
Thick‐skinned tectonics in the external Apennines, Italy: New evidence from magnetic anomaly analysis
No full textWe discuss the tectonic implications of a new residual magnetic map of the Apennine
belt/Adriatic-Apulian foreland obtained by integrating ground and offshore data sets
[Chiappini et al., 2000a]. Negative anomalies are documented over the Adriatic-Apulian
foreland areas, whereas the external Apennine belt is characterized by a ubiquitous lowamplitude (<30 nT), long-wavelength positive anomaly. In the central northern Apennines, three 100 km wide more intense (100–200 nT) round-shaped anomalies are
superimposed to the long-wavelength feature. Finally, in the Tyrrhenian Sea and margins,
high-intensity, short-wavelength positive-negative couplets coincide with magmatic outcrops or bodies at shallow depth. The low-amplitude anomaly pattern over Italy
suggests that the magnetic basement beneath the Triassic evaporites is ubiquitously
incorporated in the external belt compressive fronts, implying a thick-skinned tectonic style for the external Apennines. The new residual magnetic map resolves the inconsistency between previous aeromagnetic data [AGIP SpA. Italia, 1981], which suggested a lack of basement involvement in the Apennine belt, and recent seismic data, which imaged deep reflectors penetrating the basement. Two magnetic models along NE-SW transects in the northern and southern Apennines suggest consistent structural styles. In the northern Apennines, positive anomalies roughly coincide with the external compressive fronts, although there are local second-order differences between the belt front and the edges of the anomaly. Here the magnetic data show that the basement rises southwestward along the thrust fronts from 6–7 km depth in the Adriatic foreland to 2–3 km depth in the axial belt, where some exploration wells have penetrated basement. Within the belt front, basement exhumation is inferred to occur along high-angle, low-displacement thrust faults inverting
preexisting normal faults. In the southern Apennines, a remarkable positive magnetic
anomaly is parallel with and tens of kilometers southwest of the belt front. Seismic data and oil wells show that the basement surface cannot be shallower in the belt than in the foreland. Therefore the observed magnetic anomaly is produced by strongly magnetic basement beneath the belt, likely an internal crustal wedge tectonically interposed between the Apulian carbonate sequences and basement.Published2290JCR Journalreserve
Development and testing of seismic regional discriminants
No full textThe routine process of the IMS data at the CTBTO International Data Center (IDC) is aimed at identifying in the seismological bulletins all the seismic events the source of which is certainly natural. This process, named screening out, is carried out on several tens of earthquakes per day. It is important that the methods used for the screening process are as reliable and efficient as possible, so as substantially reducing the number of suspicious events without classifying any explosion as natural events.
The principal identification method applied at the CTBTO IDC is based on the difference between the Ms magnitude, computed from the amplitude of the surface Rayleigh waves with period close to 20 s, and the mb magnitude computed from the amplitude of the body waves with period close to 1 s. The applicability of this method is, however, limited by the difficulty of detecting surface waves for events of low mb magnitudes, so as to allow the computation the Ms magnitude for such events, which are very numerous.
For CTBT verification, in case of events of small magnitude, the use of stations at regional distances from the epicenter, is crucial. In this context, another category of seismological screening, the so-called regional discriminants, can be applied. This method is based on the amplitudes of the surface waves (Lg) at much higher frequencies (8-12 Hz). Unfortunately, these high-frequency waves are not easily detectable, and the method requires regional calibration curves for each specific site, calibrations that are not available on a global scale.PublishedVienna (Austria)6A. Monitoraggio ambientale, sicurezza e territorioope
Il materiale numismatico di età antonina dal Tevere: alcune note
No full textLa ricerca ha preso avvio dalla pulitura, consolidamento e catalogazione di materiale inedito proveniente dal Tevere e riferibile agli anni 138-161.
L’analisi del materiale antonino proveniente dal Tevere ha consentito l’individuazione di alcuni importanti spunti sulla circolazione in questo periodo, quali per primo l’aumento - soprattutto nella seconda metà del regno di Antonino Pio - delle emissioni di sesterzi, forse legato ad un iniziale processo inflattivo, o alla sua liberalità, ma anche al pagamento delle truppe e alla cospicua e lunga emissione di monete in onore della Diva Faustina. Decisamente frequenti nel Tevere sono i dupondi/assi e gli assi, presenti in percentuali equivalenti; tale risultato potrebbe avvalorare l’ipotesi che l’accumulo nel tempo di materiale numismatico nel fiume sia dovuto soprattutto a perdite occasionali. Fra il materiale tiberino databile, decisamente scarse sono le emissioni del 138-139; un altro dato in netto contrasto con quanto finora rilevato.
Anche l’attenta analisi delle tipologie ha fatto emergere alcune nuove e interessanti prospettive.
Senza dubbio interessante è l’alta concentrazione di monete con al rovescio la figura di Annona su rovesci di assi emessi tra gli anni 152-154; tale frequenza potrebbe riferirsi alla notizia di una rivolta in Egitto proprio in quegli anni. Di notevole interesse è la presenza nel Tevere del sesterzio con Enea, Anchise e Ascanio al rovescio; il sesterzio è molto raro ed attestato in un unico rinvenimento, sempre in Italia. Anche in questo caso, forse, l’esclusiva attestazione a Roma e in Italia, benché rara, potrebbe voler intendere che questo tipo per tematica sia considerato più adatto ad una circolazione in queste aree, legate in maniera più profonda a questo mito.
Allo stesso modo è raro al di fuori della Britannia, dove è rinvenuto in massicce quantità, l’asse con la personificazione di questa provincia, emesso negli anni 153-155; i pur scarsi ed esigui ritrovamenti al di fuori della Britannia dove alcuni ritengono sia stato emesso e dove circola abbondantemente, fa pensare che possa trattarsi di monete arrivate in aree esterne a seguito delle frequentazioni e degli spostamenti dei possessori, forse mercanti, soldati o ex militari.
Altro dato emerso dall’analisi del materiale dal Tevere e sinora mai evidenziato è il carattere prevalentemente militare dei rovesci di Marco Aurelio; si tratta di un aspetto comune a tutta la sua monetazione e che risulta, al contrario, assente nella contemporanea monetazione di Antonino. Sembra difficile stabilire il motivo di una simile distinzione ed in particolare se tale differenziazione possa rispecchiare due diversi ruoli istituzionali ricoperti dall’Augusto e dal Cesare.
Per quanto riguarda l’esame del materiale riferibile alle Auguste bisogna innanzitutto rilevare la difficoltà di datazione delle emissioni delle due Faustine e, correlata a questo aspetto, la distinzione dei nominali delle loro coniazioni.
Sin qui le considerazioni emerse dall’analisi diretta del materiale dal Tevere; ma nel corso dell’indagine non si è potuto, ovviamente, prescindere dall’analisi di tutta la monetazione di Antonino Pio e dei suoi familiari, nel tentativo di evidenziare ulteriori aspetti di questo imperatore e del suo principato, tra continuità e discontinuità con Adriano.
Pur distaccandosi al momento dell’assunzione del principato dalla politica e dalla volontà del suo predecessore e padre adottivo, in molti aspetti del proprio principato Antonino si dimostra il continuatore della politica adrianea. Seguendo l’esempio del suo predecessore, Antonino ritiene opportuno portare avanti una politica diplomatica o di consolidamento, la cui più viva espressione sono la vasta attività di pacificazione e difesa dei confini, e la fortificazione e costruzione di limites. Come il padre adottivo, Antonino si preoccupa anche di celebrare la propria liberalità attraverso l’emissione dei tipi con la scena di elargizione rappresentata secondo la tradizionale iconografia del congiario degli imperatori precedenti e della nuova personificazione della Liberalitas, introdotta proprio da Adriano.
L’esigenza di un rinnovamento religioso e il ricorso ai concetti di esaltazione di Roma e celebrazione dei miti di fondazione che Antonino riprende per la serie monetale emessa in occasione del nono centenario della fondazione di Roma, erano vivi già al tempo di Augusto. Rispetto al passato, tuttavia, più spiccato è il ritorno alle origini, a quella religiosità tradizionale ed arcaica, come dimostrano le scelte tipologiche operate da Antonino per tali emissioni. La diffusione di tali tematiche della propaganda antonina si può cogliere nelle coniazioni in onore della Diva Faustina, sulle quali il concetto di Aeternitas trova più ampio sviluppo. Molto frequente è, infatti, nella monetazione della Diva il ricorso all’immagine della personificazione dell’Aeternitas e alla legenda AETERNITAS che accompagna le raffigurazioni di numerose dee e personificazioni.
Sembra evidente, pertanto, che nelle scelte tipologiche la monetazione antonina dimostri una propensione verso il nuovo, ma senza che questo significhi forti stravolgimenti ideologici o rivoluzioni. Numerosi temi e molti tipi sono ripresi dal precedente regno di Adriano, ma anche una buona parte del repertorio iconografico tradizionale viene ora riproposto, ma solamente dopo averlo reinterpretato e attualizzato. La monetazione della Diva ne è l’esempio più convincente: nelle sue emissioni ogni raffigurazione è sfruttata al massimo delle potenzialità espressive e da qui l’esigenza di molteplici varianti di uno stesso tipo non sempre facilmente identificabili. Una tale varietà può, senza dubbio, celare una complessità di pensiero e idee alla base della propaganda antonina che finora non era completamente emersa e che, al contrario, dovrebbe essere, in futuro, approfondita ed indagata, soprattutto alla luce dei nuovi studi che si stanno svolgendo e, pertanto, anche del proseguimento della pulitura, catalogazione e analisi del materiale tiberinoThe research started by cleaning, consolidation and cataloging of new material from the Tiber, and it refers to the years 138-161.
The analysis of the antonine material from the Tiber has allowed the identification of some important insights about the circulation of coins in this period, principally the increase - especially in the second half of the reign of Antoninus Pius - of emissions of sesterces. Definitely common from Tiber are Dupondi/Asses and As, which are present in equal percentage. Among the material from the Tiber, there are very low emissions of 138-139, another element in stark contrast to what has been detected.
Even the careful analysis of the types has revealed some new and interesting perspectives.
Certainly interesting is the high concentration of coins with, at the reverse, the figure of Annona on assi issued between the years 152-154, the frequency could refer to the news of a revolt in Egypt in those years. Of particular interest is the presence in the Tiber of sesterzi with Aeneas, Anchises and Ascanius in reverse; the sestertius is very uncommon and certificated in a single discovery in Italy.
Similarly it is rare outside of Britain, where it is found in massive quantities, the asse with the embodiment of this province, issued in the years 153-155, while the poor and small discoveries outside of Britain, where some consider it has been issued and where it has circulated abundantly, suggest that it may be coins coming in outdoor areas as a result of frequent movements of the holders, perhaps merchants, soldiers or former soldiers.
Another fact revealed by the analysis of material from the Tiber and so far never revealed,is the predominantly military nature of Marcus Aurelius, on the reverse, absent in the contemporary coinage of Antoninus.
Regarding the examination of the material refering to Augustaewe, we must note the difficulty of dating the emission of two Faustine, and, related to this issue, the distinction of their nominal coinage.
During the investigation it was not possible, of course, disregard the analysis of the whole coinage of Antoninus Pius and his family in an effort to highlight more aspects of the emperor and his princedom, between continuity and discontinuity with Hadrianus.
Typological choices in the Antoninus coinage showa a propensity towards the new, but without strong ideological upheavals or revolutions. Many themes and many types come from the reign of Hadrian, but also a good part of the traditional iconographic repertoire has now been presented again, but only after it has been re-interpreted and updated. The Diva’s coinage is the most convincing example: in its emissions each representation is exploited to maximum expressive potential and hence the need for multiple variants of the same type which are not always easily identifiable. This variety can, of course, hide a complexity of thought and ideas behind the Antoninus propaganda that has not been fully revealed yet and that, conversely, should be in the future deeply investigated, especially in light of new recent studies and, therefore, furtherance of cleaning, cataloging and analysis of the material from Tibe
Optimal Control Strategies for Composting Processes in Biocells with L1 −Type and L2 −Type Cost Objectives
No full textWe present a finite horizon optimal control problem for composting in biocell. The problem is based on a mathematical model, which describes the degradation of organic waste by an aerobic biomass. Solubilization of insoluble substrate and biomass decay phenomena are also taken into account. The degradation is controlled by monitoring the effects of oxygen concentration in the cell. The optimal strategy is determined by minimizing the total costs given by the final size of soluble substrate and the operating cost. We consider two different cases, where the operating cost is modeled by linear and quadratic function of the effort, respectively. It is shown that the total costs over the considered time interval are higher in the linear case than in the quadratic case. Moreover, when compared to the quadratic case, the linear case results in a higher reduction of soluble substrate concentration but it requires also a higher effort to control the degradation
Modern lattice Boltzmann methods for multiphase microflows
No full textDuring the last decade, the lattice Boltzmann (LB) method has captured an increasing attention as an efficient tool for the numerical simulation of complex fluids, particularly multiphase and multicomponent flows. In this paper, we revisit the basic features of two modern variants of LB models for non-ideal fluids, which offer promising perspectives for the numerical simulation of complex microflows. © 2011 The Author
Optical spectroscopy of TeO2–GeO2 glasses activated with Er3+ and Tm3+ ions
No full textThe optical and spectroscopic properties of Er3+- and Tm3+-activated germano-tellurite glasses of molar composition 90TeO2:
10GeO2 and 80GeO2:20TeO2, prepared by melt-quenching, have been studied. The refractive indices at three different wavelengths
in the visible and near infrared have been measured. The vibrational properties of the glasses were studied by Raman spectroscopy.
The Raman spectra indicate that the GeO2 and TeO2 components of the glasses do not mix well at the microscopic level. The spectroscopic
properties of the rare earth ions were investigated by absorption spectroscopy and time resolved photoluminescence. The
Er3+ 4I13/2 !4I15/2 transition shows a bandwidth of about 70 nm with a lifetime of about 3 ms. The 3H4 - 3F4 transition of Tm3+
ion has a bandwidth of 115 nm in the TeO2-based glass, and of 135 nm in the GeO2-based glass. The lifetime of 3H4 is less than
0.2 ms
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