FEW SHOT PHOTOGRAMETRY: A COMPARISON BETWEEN NERF AND MVS-SFM FOR THE DOCUMENTATION OF CULTURAL HERITAGE

3D documentation methods for Digital Cultural Heritage (DCH) domain is a field that becomes increasingly interdisciplinary, breaking down boundaries that have long separated experts from different domains. In the past, there has been an ambiguous claim for ownership of skills, methodologies, and expertise in the heritage sciences. This study aims to contribute to the dialogue between these different disciplines by presenting a novel approach for 3D documentation of an ancient statue. The method combines TLS acquisition and MVS pipeline using images from a DJI Mavic 2 drone. Additionally, the study compares the accuracy and final product of the Deep Points (DP) and Neural Radiance Fields (NeRF) methods, using the TLS acquisition as validation ground truth. Firstly, a TLS acquisition was performed on an ancient statue using a Faro Focus 2 scanner. Next, a multi-view stereo (MVS) pipeline was adopted using 2D images captured by a Mini-2 DJI Mavic 2 drone from a distance of approximately 1 meter around the statue. Finally, the same images were used to train and run the NeRF network after being reduced by 90%. The main contribution of this paper is to improve our understanding of this method and compare the accuracy and final product of two different approaches - direct projection (DP) and NeRF - by exploiting a TLS acquisition as the validation ground truth. Results show that the NeRF approach outperforms DP in terms of accuracy and produces a more realistic final product. This paper has important implications for the field of CH preservation, as it offers a new and effective method for generating 3D models of ancient statues. This technology can help to document and preserve important cultural artifacts for future generations, while also providing new insights into the history and culture of different civilizations. Overall, the results of this study demonstrate the potential of combining TLS and NeRF for generating accurate and realistic 3D models of ancient statues

COMPORTAMENTO SUPERPLASTICO DELLA LEGA DI MAGNESIO AZ31 PRODOTTA MEDIANTE “TWIN ROLL CASTING”

Le leghe di Magnesio hanno grandi potenzialità come materiali strutturali, soprattutto per applicazioni nel settore dei trasporti, per il loro basso peso specifico. La scarsa deformabilità a temperatura ambiente ne limita, tuttavia, l’impiego a componenti ottenuti prevalentemente per fusione. Studi recenti hanno evidenziato la possibilità di avere superplasticità in alcune leghe di magnesio, che sarebbero quindi utilizzabili in processi di formatura, per la produzione di componenti near-net-shape di forma complessa. È noto, tuttavia, che il comportamento superplastico è tipicamente rilevabile solo in materiali a microstruttura controllata (grano fine e stabile nel corso della deformazione), quando deformati a temperature e con velocità di deformazione opportune. In questo lavoro sono presentati i risultati di prove di trazione in regime di superplasticità, effettuate sulla lega di magnesio AZ31, prodotta mediante Twin Roll Casting (un processo di colata continua diretta all’interno di due cilindri controrotanti e raffreddati ad acqua) e successivamente laminata a caldo. Il materiale così trattato ha presentato un comportamento superplastico a temperature comprese tra 400 e 420 °C, con un valore massimo dell’allungamento a rottura del 370% a 400 °C e con velocità di deformazione di 1·10-3 s-1. Tali valori sono correlabili alla favorevole microstruttura a grani fini ed equiassici, che favorisce la deformazione controllata dal meccanismo di scorrimento a bordo grano (GBS), come confermato da analisi metallografiche e frattografiche condotte sui campioni deformati

STUDI DI OTTIMIZZAZIONE DEI TRATTAMENTI TERMICI SU UNA LEGA AL-SI PER USO AUTOMOBILISTICO

Oggetto di questo lavoro è lo studio di trattamenti termici sulla lega 87S1 (nome commerciale), derivata dalla A357, appositamente modificata per migliorare la sua formabilità allo stato semi-solido. Tale lega è particolarmente idonea ad essere formata attraverso il processo Rheocast per la produzione di componenti soprattutto automobilistici. Per la lega presa in esame le caratteristiche meccaniche migliori sono state ad oggi ottenute con il trattamento brevettato dal produttore, un trattamento T6 con solubilizzazione multistadio seguito da un invecchiamento. La finalità del presente studio è quella di valutare la possibilità di effettuare un trattamento termico più economico di quello proposto senza gravose conseguenze per le proprietà meccaniche. La lega è stata sottoposta a trattamenti termici, prove meccaniche ed indagini microstrutturali di microscopia ottica ed elettronica in scansione. Sono stati studiati diversi trattamenti termici, T5 e T6 non multistadio di durate inferiore rispetto a quello brevettato, ottenendo, in alcuni casi, risultati promettenti in termini di proprietà di interesse ingegneristico. In particolare si è osservato come un semplice trattamento termico di solubilizzazione a 500°C per 4 ore fosse in grado di garantire un buon compromesso fra resistenza meccanica e duttilità a temperatura ambiente

STUDIO COMPARATIVO DELL’AFFINAMENTO MICROSTRUTTURALE DURANTE TORSIONE-COMPRESSIONE E DOPO EQUAL-CHANNEL ANGULAR PRESSING

Tecniche di deformazione plastica severa, quali twist extrusion, deformazione ciclica, corrugate roll-bonding ed equal-channel angular pressing, applicate ai materiali metallici sono ormai giunte ad un livello di applicazione industriale. Si è ormai diffusa un’ampia letteratura che riguarda ogni aspetto di carattere microstrutturale e meccanico sulle differenti tecniche di deformazione plastica severa di interesse industriale applicate a materiali metallici ferrosi e non ferrosi (leghe di alluminio, titanio, magnesio). Questo studio ha l’obiettivo di esplorare le similitudini e le potenzialità di una tecnica di deformazione quale la torsionecompressione, la quale coinvolge costi ben più ridotti e probabilmente una più immediata fattibilità industriale, rispetto ad una delle tante altre tecniche già disponibili, nello specifico l’ECAP. Il confronto tra la torsione-compressione e l’ECAP è stato limitato ad una deformazione vera pari ad å=1 ed una deformazione uguale per la torsione-compressione, con =510-3s-1 in torsione, seguita dalla deformazione in compressione di =510-3s-1. Per tale studio è stata utilizzata una lega AA6103 Al-Mg-Si dopo ricottura. Le indagini microstrutturali sono state eseguite mediante microscopia elettronica in trasmissione e in luce polarizzata al microscopio ottico

Constitutional trisomy 8 as first mutation in multistep carcinogenesis: clinical, cytogenetic, and molecular data on three cases.

Three patients, with constitutional trisomy 8 mosaicism (CT8M), who developed a malignancy are reported. The diagnoses were refractory anaemia, acute lymphoblastic leukaemia, and idiopathic myelofibrosis. In the child with acute leukaemia, the CT8M was diagnosed at birth due to severe dysmorphisms and malformations; the other two patients showed a milder phenotype, and the CT8M was diagnosed only after the finding of trisomy 8 in neoplastic cells. The review of eight similar, previously reported cases and the clinical, cytogenetic, and molecular studies performed in our patients led us to make the following observations: (1) CT8M predisposes to neoplasms, preferentially to myelo- or lymphoproliferative diseases; (2) a gene dosage effect for glutathione reductase in red blood cells was seen in two of our patients; (3) the wide phenotypic variation of CT8M was confirmed: trisomy 8 in neoplastic cells of phenotypically near-normal cases may be misinterpreted as acquired; and (4) molecular studies suggested a postzygotic origin of the trisomy in our three cases, with the supernumerary chromosome being of paternal origin in one case and of maternal origin in the other two. We postulate that the trisomy 8 in neoplasms may often occur by mitotic nondisjunction in an early embryonic multipotent cell and that what is usually interpreted as an acquired trisomy 8 may in fact be CT8M. The constitutional trisomy 8 would act as a pathogenetically important first mutation in multistep carcinogenesis. Whenever trisomy 8 is found in malignancies, the patient should be reevaluated clinically to exclude CT8M, and CT8M patients should be monitored for the possible development of malignancies

Comparative Study Of High Temperature Workability OF ZM21 And AZ31 Magnesium Alloys

High temperature regime, 300-450?C for Mg-Al-Zn alloys, is currently used in primary processing, such as rolling and extrusion, as well as for secondary operation like forging. The knowledge of temperature and strain rate proper combination (processing window) as well as the microstructure evolution occurring during hot deformation clarifies the relationships between forming variables and final properties of components. Numerous data on AZ31 and few other Mg-Al alloys, produced by laboratory testing, are available in the scientific and technical literature. The ZM21, Mg-2Zn-1Mn, by contrast, is characterized by absolute lack of scientific data. In the alloy the addition of manganese, by suppressing the formation of beta phase, increases the solidus temperature that results in the larger processing window than in AZ31. The benefit requires extensive analysis aimed at optimizing the deformation variables that affect the microstructure refinement under dynamic and static recrystallization. The high-temperature plastic deformation and the microstructure evolution of the ZM21 were thus investigated in the temperature range between 200 and 500?C and results were analysed and compared with those of a conventional heat-treated AZ31

Personalizing Cancer Pain Therapy: Insights from the Rational Use of Analgesics (RUA) Group

Introduction: A previous Delphi survey from the Rational Use of Analgesics (RUA) project involving Italian palliative care specialists revealed some discrepancies between current guidelines and clinical practice with a lack of consensus on items regarding the use of strong opioids in treating cancer pain. Those results represented the basis for a new Delphi study addressing a better approach to pain treatment in patients with cancer. Methods: The study consisted of a two-round multidisciplinary Delphi study. Specialists rated their agreement with a set of 17 statements using a 5-point Likert scale (0 = totally disagree and 4 = totally agree). Consensus on a statement was achieved if the median consensus score (MCS) (expressed as value at which at least 50% of participants agreed) was at least 4 and the interquartile range (IQR) was 3–4. Results: This survey included input from 186 palliative care specialists representing all Italian territory. Consensus was reached on seven statements. More than 70% of participants agreed with the use of low dose of strong opioids in moderate pain treatment and valued transdermal route as an effective option when the oral route is not available. There was strong consensus on the importance of knowing opioid pharmacokinetics for therapy personalization and on identifying immediate-release opioids as key for tailoring therapy to patients’ needs. Limited agreement was reached on items regarding breakthrough pain and the management of opioid-induced bowel dysfunction. Conclusion: These findings may assist clinicians in applying clinical evidence to routine care settings and call for a reappraisal of current pain treatment recommendations with the final aim of optimizing the clinical use of strong opioids in patients with cancer

Thin Polymer Brush Decouples Biomaterial's Micro-/Nano-Topology and Stem Cell Adhesion

Surface morphology and chemistry of polymers used as biomaterials, such as tissue engineering scaffolds, have a strong influence on the adhesion and behavior of human mesenchymal stem cells. Here we studied semicrystalline poly(ε-caprolactone) (PCL) substrate scaffolds, which exhibited a variation of surface morphologies and roughness originating from different spherulitic superstructures. Different substrates were obtained by varying the parameters of the thermal processing, i.e. crystallization conditions. The cells attached to these polymer substrates adopted different morphologies responding to variations in spherulite density and size. In order to decouple substrate topology effects on the cells, sub-100 nm bio-adhesive polymer brush coatings of oligo(ethylene glycol) methacrylates were grafted from PCL and functionalized with fibronectin. On surfaces featuring different surface textures, dense and sub-100 nm thick brush coatings determined the response of cells, irrespective to the underlying topology. Thus, polymer brushes decouple substrate micro-/nano-topology and the adhesion of stem cells