1,573 research outputs found
I pigmenti pittorici: una risposta della chimica
No full textSono state effectuate misure non distruttive per la caratterizzazione del materiale pittorico e della tecnica di preparazione usata nel sarcofago di Paherienaset
Non destructive characterisation of several copper–based finds from different archaeological sites of Liguria (Italy)
No full textCaratterizzazione mediante metodi non distruttivi di alcuni reperti metallici liguri
Thermal, XRD and spectrophotometric study on artificially degraded woods
No full textThermogravimetry, differential thermal analysis, differential scanning calorimetry in oxygen flux were used to characterize two wood types: fir and chestnut woods. They were characterized by the peak temperatures of DTA, DTG and DSC curves and by the
different mass losses evaluated on the basis of the measured thermal data. The samples were woods in powder obtained during sawing. Complementary characterization of the woods was performed by estimating the crystallinity of cellulose by means of X-ray powder diffraction. In order to simulate the degradation of wet woods, fir and chestnut woods were put into deionised water and into artificial sea water for several weeks; some samples of woods contained Cu and Fe nails to ascertain the effect of these metals on the degradation process. The thermal and X-ray diffraction measurements were then performed on the wet woods, following the same previous procedure. X-ray fluorescence was used to investigate the penetration of metals into wood samples
Study of artificially degraded woods simulating natural ageing of archaeological findings
No full textSimulation of waterlogged archaeological woods was carried out by immersion of fir and chestnut wood samples into sea water at different
temperatures (room temperature and 40°C). The effects of metals in contact with woods were simulated by inserting in some
specimens of the two types of wood copper or iron nails, the most important metals from the archaeological point of view. The effects
of this ageing simulation on woods were studied by different characterization methods. At first we have performed gravimetric analyses,
controlling the mass increase of immersed wood in function of the time of immersion and the temperature of the bath. Then,
thermogravimetry, differential thermal analysis, differential scanning calorimetry in oxygen flux were used. The alteration of wood was
observed by means of the peak temperatures of DTA, DTG and DSC variation and by the mass losses observed during heating, evaluated
on the basis of the measured thermal data. The samples were woods powder obtained by milling. Complementary characterization
of the woods was performed by evaluating the crystallinity of cellulose by means of X-ray powder diffraction. The change in colour of
woods during ageing was checked by means of spectrophotometric measurements in the visible region.
X-ray fluorescence was used to investigate the penetration of metals into wood samples. An artificial ageing treatment with
NaOH and O3 was also performed.
Finally, a comparison between the effects of artificial alteration realised in our specimens and natural degradation observed in
archaeological woods, was performed
Caratterizzazione chimico fisica di legni bagnati e confronto con legni archeologici
No full textQuesto lavoro presenta una metodica per la diagnostica e la caratterizzazione di legni
bagnati basata sull’uso di alcune tecniche di indagine chimico fisica: diffrazione dei
raggi X (XRD), analisi termica differenziale (DTA) e termogravimetrica (TG), calorimetria
a scansione differenziale (DSC), misure di colore, spettroscopia infrarossa in
trasformata di Fourier (FTIR), fluorescenza dei raggi X (XRF). Castagno (hardwood) e abete
(softwood) sono stati i tipi di legno presi in esame per verificare tale metodica. I campioni di
castagno e abete, tal quali e dopo l’inserimento di chiodi metallici, sono stati immersi in acqua
deionizzata e acqua di mare sintetica a temperatura ambiente e a 40°C per effettuare una impregnazione
preliminare.
Il periodo di immersione è durato per tempi variabili ed al minimo per otto settimane. I chiodi
usati sono stati di ferro e rame, metalli molto diffusi in antichità. La penetrazione degli ioni
metallici è stata controllata tramite misure di fluorescenza dei raggi X.
Ogni settimana sono state eseguite misure di colore e di peso sui campioni e si è provveduto
alla sostituzione dell’acqua con altra fresca.
Dopo l’immersione, tramite operazioni di segatura e macinatura sono stati ottenuti campioni
polverizzati. La macinatura provoca, come noto, una diminuzione del grado di cristallinità della
cellulosa nei legni, ma non vi è alcun dato quantitativo circa tale effetto, che ci proponiamo
di valutare tramite un proseguimento della nostra ricerca. Lamacinatura è, comunque, necessaria
per ottenere campioni omogenei e misure riproducibili.
Le analisi diffrattometriche, termiche e calorimetriche hanno permesso di mettere in evidenza
l’effetto di degrado provocato sulle due specie lignee da parte dell’acqua di mare e dei metalli.
Per studiare il deterioramento del legno si è proceduto alla misura del grado di cristallinità dei
campioni tramite XRD tenendo in considerazione il picco principale della cellulosa (002) che
cade a circa 22,4° di 2θ. Sui legni archeologici è stata ripetuta la stessa serie di indagini e i risultati
sono stati confrontati con quelli ottenuti per i legni campione. Inoltre la spettroscopia infrarossa
in trasformata di Fourier (FTIR) è stata utilizzata quale ulteriore convalida dei confronti effettuati.
Infine, la sequenza delle reazioni di decomposizione termica è stata valutata tramite una serie
di prove condotte eseguendo combustioni parziali di campioni di abete a temperature via via
crescenti, comprese tra 225° e 350°C, in ambiente ossidante. I prodotti sono stati caratterizzati
mediante misure di perdita in peso e di cristallinità, che hanno permesso di individuare le principali
frazioni, amorfe o cristalline, coinvolte nei processi ossidativi
HVAC System Performance in Educational Facilities: A Case Study on the Integration of Digital Twin Technology and IoT Sensors for Predictive Maintenance
No full textThis research paper delves into the pivotal role of Digital Twin technology and Internet of Things (IoT) sensors in revolutionizing predictive maintenance for Heating, Ventilation, and Air Conditioning (HVAC) systems within educational environments, exemplified by a comprehensive case study at the "Papa Giovanni XXIII" school in Nichelino, Italy. Marking a significant departure from traditional Building Information Modeling (BIM) practices, Digital Twin technology introduces a real-time, dynamic representation of building systems, enabling proactive rectification of system
inefficiencies and failures to improve building performance, occupant well-being, and sustainability. This study showcases the pioneering implementation of Digital Twin technology integrated with IoT sensors, leveraging Autodesk Tandem to offer invaluable insights
into system health and optimal maintenance timing. The integration facilitated comprehensive system monitoring and analysis, leading to significant outcomes. Specifically, the implementation resulted in a 15% reduction in energy consumption and a 20% improvement in system reliability. Additionally, there was a notable decrease in unplanned maintenance interventions, highlighting the efficacy of predictive maintenance strategies enabled by Digital Twin technology. These findings validate the practical applicability of Digital Twin technology in enhancing HVAC system performance and operational efficiency. The study underscores the transformative potential of this digital leap in the construction sector's
ongoing evolution towards greater digitalization. By addressing technological complexities and substantial initial investments, this research paves the way for future advancements in smart building technologies, making a crucial contribution to the emerging discourse on Digital Twins in construction
Construction Safety and Efficiency: Integrating Building Information Modeling into Risk Management and Project Execution
No full textIn the evolving construction landscape, this study introduces a novel methodology leveraging Building Information Modeling (BIM) to revolutionize safety management across diverse projects. By transitioning from traditional, reactive approaches to a proactive, comprehensive framework, BIM’s integration into the design and execution phases enables the dynamic assessment and mitigation of risks, thereby enhancing workplace safety. Grounded in an extensive literature review and underscored by the implementation in two case studies—the Search for Hidden Particles (SHiP) experiment at CERN and the Basilica of Santa Croce’s façade maintenance in Florence—this research demonstrates BIM’s significant impact on reducing accidents, ensuring adherence to safety protocols, and streamlining project execution. Comparative analysis with traditional methods confirms BIM’s superiority in risk mitigation, safety outcomes, and project efficiency. Stakeholder feedback further validates the methodology’s effectiveness, marking a shift towards its broader adoption for safer, more efficient construction practices. Future directions suggest exploring BIM’s scalability, integration with emerging technologies, and long-term impacts on safety and sustainability, aiming for its standardization across the construction industry
Experience in the Management of Frontal Sinus Fractures
No full textInternational guidelines for frontal sinus fractures, dealing with the indication Of Surgical treatment, obliteration of the frontal sinus, drainage, and cranialization, may differ. In this work, we describe our experience with frontal traumas, analyzing indications, type of treatment, and outcomes by reviewing all data of 112 patients treated for frontal fractures at the Department of Maxillo-Facial Surgery, Universita degli studi di Roma Sapienza. We reviewed all clinical and surgical records of patients with traumatic frontal injury treated from 1997 to September 2008, Patients presenting displaced fractures of the anterior wall of the frontal sinus were treated through skin laceration, if existing, or through a coronal approach and fixed with rigid internal devices. Patients with fracture of the posterior wall of the frontal sinus underwent frontal sinus cranialization with galea pericranium pedicled flap to prevent eventful septic complications. Follow-up controls documented that 98 of 112 patients showed no neurologic impairment, no symptoms of cerebrospinal fluid leak, and no other complications after 6 months and I and 5 years when follow-up was possible. In the international literature, there is wide agreement about indications dealing with displaced fractures of the anterior wall, although there is a lively debate about posterior wall treatment. In Our 10-year experience, the protocol we carried out showed satisfying outcomes, in particular, on the morphofunctional recovery and aesthetic results
Cleft lip and palate: Technical strategies for the primary palatoplasty
No full textSurgical procedures in cleft lip and palate repair are continuously evolving. In the international literature, many guidelines exist dealing with different timings and surgical approaches. The authors present a technical strategy on primary palatoplasty and the guidelines for the surgical management of cleft lip and palate adopted by the Department of Maxillo-Facial Surgery of the Universita "La Sapienza" of Rome. This approach has been developed to allow a physiological facial growth and to preserve the essential main features of the stomatognathic system enclosing phonation and swallowing. Moreover, the authors present their own surgical technique for primary palate repair at 24 to 48 months with the galea-pericranium free flap
Caratterizzazione Archeometrica
No full textCaratterizzazione mediante tecniche non invasive di due opere pittoriche
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