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Deep Convolutional Framelets for Dose Reconstruction in Boron Neutron Capture Therapy with Compton Camera Detector
No full textBackground: Boron neutron capture therapy (BNCT) is an innovative binary form of radiation therapy with high selectivity towards cancer tissue based on the neutron capture reaction 10B(n, (Formula presented.) )7Li, consisting in the exposition of patients to neutron beams after administration of a boron compound with preferential accumulation in cancer cells. The high linear energy transfer products of the ensuing reaction deposit their energy at the cell level, sparing normal tissue. Although progress in accelerator-based BNCT has led to renewed interest in this cancer treatment modality, in vivo dose monitoring during treatment still remains not feasible and several approaches are under investigation. While Compton imaging presents various advantages over other imaging methods, it typically requires long reconstruction times, comparable with BNCT treatment duration. Methods: This study aims to develop deep neural network models to estimate the dose distribution by using a simulated dataset of BNCT Compton camera images. The models pursue the avoidance of the iteration time associated with the maximum-likelihood expectation-maximization algorithm (MLEM), enabling a prompt dose reconstruction during the treatment. The U-Net architecture and two variants based on the deep convolutional framelets framework have been used for noise and artifact reduction in few-iteration reconstructed images. Results: This approach has led to promising results in terms of reconstruction accuracy and processing time, with a reduction by a factor of about 6 with respect to classical iterative algorithms. Conclusions: This can be considered a good reconstruction time performance, considering typical BNCT treatment times. Further enhancements may be achieved by optimizing the reconstruction of input images with different deep learning techniques
Methane, Ethane, and Propane Detection Using a Quartz-Enhanced Photoacoustic Sensor for Natural Gas Composition Analysis
No full textA compact and portable gas sensor based on quartz-enhanced photoacoustic spectroscopy (QEPAS) for the detection of methane (C1), ethane (C2), and propane (C3) in natural gas (NG)-like mixtures is reported. An interband cascade laser (ICL) emitting at 3367 nm is employed to target absorption features of the three alkanes, and partial least-squares regression analysis is employed to filter out spectral interferences and matrix effects characterizing the examined gas mixtures. Spectra of methane, ethane, and propane mixtures diluted in nitrogen are employed to train and test the regression algorithm, achieving a prediction accuracy of ∼98%, ∼96%, and ∼93% on C1, C2, and C3, respectively. With respect to previously reported QEPAS sensors for natural gas analysis, the high prediction accuracy as well as the capability to discriminate and detect C3 within natural gas-like complex mixtures provided by the employment of partial least-squares regression mark significant improvements. Furthermore, these results enable an improved performance of the sensor for in situ, real-time, and online natural gas composition analysis
Tailored multiscale instabilities in a grid metamaterial
No full textIn this study, we investigate a plane metamaterial made up of a periodic grid of shear-deformable rods with rigid finite-size joints, subjected to a biaxial macro-stress state. We derive closed-form solutions for the stability domains by means of Floquet-Bloch theory. Remarkably, this analytical modeling enable us to determine how the size of the rigid joints yields to transition from macroscopic to microscopic critical modes (i.e. pattern transformation) for specific macro-stress states. We also examine a minimum weight problem for this class of metamaterials. The analytical model predictivity in describing multiscale instabilities is validated by comparisons with experimental findings and numerical analyses
Empowering spintronics with antiferromagnetic diodes: Spintronics
No full textA spintronic diode made from a W/Mn3Sn bilayer shows broadband rectification at frequencies up to 30 GHz
Learning from the Roman house. Dom Hans van der Laan: Experience-spaces and constructional analogies
No full textDom Hans van der Laan’s architecture and archetypal models as described in
his 1977 publication Architectonic Space aim to provide universal fundamentals,
with an ahistorical perspective. The only specific references are to Vitruvius and
Stonehenge. Nevertheless, research of Van der Laan’s archives and rare travel
diaries reveals a series of ancient historical references that can be uncovered,
from an early map of Rome to the study trip to Italy in 1969. Van der Laan dealt
with the theory of architectonic disposition in the CKA between 1968 and 1973,
after working on the plastic number and on architectonic form. The 1969 trip
to Italy and the first-hand visits to the ruins enabled him to confirm and further
develop his theories on architecture
Modeling Interferometric Optical Gyroscopes: An Experimentally Validated Approach
No full textInterferometric optical gyroscopes (IOGs) are critical for precise angular velocity measurements in aerospace and defense applications. Despite extensive advancements, accurately modeling IOGs remains a challenge due to complex noise sources and environmental disturbances. However, most existing models lack experimental validation, limiting their practical utility. Here, we show a numerical model validated using a fiber-optic gyroscope (FOG) integrating a 500-m-long polarization-maintaining coil. The model includes a comprehensive noise analysis, incorporating thermal noise, shot noise, and the Kerr effect. For square-wave and sine-wave modulation, we achieve an average discrepancy of less than 6% between numerical and experimental results. Our findings demonstrate that the gyro's static response is well predicted by the model across varying angular velocities. This work provides a fundamental framework for the design and optimization of IOGs, while also facilitating the development of complex models capable of accurately predicting the operation of advanced IOG-based navigation systems
An integrated methodology for supporting the design of 3D-printed building components
Get PDFL’industria delle costruzioni ad oggi è globalmente fra le più impattanti sull’ambiente. Uno sguardo al passato può farci interrogare su come si siano trasformati i sistemi abitativi e su come sopperire alle criticità attuali. Un fattore comune nelle architetture del passato è sempre stato ad ogni latitudine l’adattamento al clima e al contesto naturale. Per far fronte al caldo, al freddo, ai venti del sito in cui sarebbero sorte, le tipologie edilizie venivano adattate con specifiche forme e materiali il più delle volte reperiti localmente. È così che la trasformazione delle costruzioni attraverso i secoli ci ha restituito un panorama architettonico vario e distinto per ogni area della terra.
Questa tendenza è stata invertita a partire dalla seconda rivoluzione industriale quando la standardizzazione di tecniche costruttive ha preso il posto di metodi tradizionali e locali. L’uso del calcestruzzo armato si è diffuso ad ogni latitudine condizionando le forme architettoniche non più adattate ai contesti climatici. Per sopperire alle esigenze di natura termo-igrometrica degli ambienti interni si è fatto quindi ricorso agli impianti di condizionamento termico sempre più diffusi. Ciò ha reso plausibile che lo stesso edificio potesse essere costruito in qualunque parte del globo. Le conseguenze di questa attitudine possono essere annoverate fra le cause dell’attuale grande impatto del settore delle costruzioni sull’ambiente. Infatti, il minore uso di materiali locali; il maggiore consumo di materie prime; l’aumento dei trasporti di elementi costruttivi; il maggiore consumo energetico concorrono all’incremento delle emissioni. Un ulteriore aspetto irrimediabilmente trascurato nell’ultimo secolo è stato la varietà delle forme architettoniche e il corrispondente adattamento all’ambiente circostante.
Negli ultimi decenni il progresso tecnologico dell’industria delle costruzioni è stato molto lento se comparato ad altri settori industriali che hanno aumentato la propria produttività ed efficienza adottando tecnologie innovative. La stampa 3D è una tecnologia produttiva, già affermata in altri settori industriali, il cui interesse si è rapidamente diffuso per l’impiego nelle costruzioni rivelandosi una delle tecnologie più promettenti per innovare il settore. Le potenzialità riguardano la riduzione di costi, la riduzione dei consumi energetici, la riduzione di materiali di scarto, l’automatizzazione dei processi costruttivi riducendo i rischi per i lavoratori e le possibilità di errore, l’aumento della produttività e l’aumento dell’efficienza. Inoltre, la tecnologia di stampa 3D offre un maggiore grado di libertà per le forme architettoniche ossia forme curve e variabili nelle tre dimensioni possono essere realizzate facilmente rispetto a quanto permettano tecnologie tradizionali. Questa libertà architettonica potrebbe fornire una risposta alla ricerca di un approccio sostenibile alle costruzioni, in quanto consentirebbe di ritrovare un legame tra forme architettoniche e ambiente circostante.
Lo scopo principale del presente lavoro di tesi è esplorare le possibilità che la stampa 3D offre all'industria delle costruzioni. In particolare, studiando l'evoluzione della stampa 3D per l'edilizia sia dal punto di vista del mercato che dell'innovazione scientifica, sono stati evidenziati gli attuali limiti all'applicabilità diffusa della tecnologia di stampa 3D per la costruzione di edifici. Affinché la stampa 3D delle costruzioni diventi una tecnologia affermata infatti è necessario che i prodotti edilizi stampati risultino concorrenziali nel mercato esistente dal punto di vista delle performance. Per superare alcuni di questi limiti, la corrente trattazione propone un approccio metodologico di supporto alla progettazione di componenti edilizi basato sulla parametrizzazione di modelli digitali e sull’analisi iterativa delle prestazioni degli stessi per ottenere elementi di involucro adattabili a diverse condizioni al contorno e prefabbricabili con la tecnologia di stampa 3D. La metodologia proposta segue un processo iterativo di quattro fasi: I. sviluppo del design e modellazione parametrica; II. definizione dei criteri prestazionali e delle condizioni al contorno; III. simulazione delle prestazioni e identificazione dei parametri; IV. produzione con stampa 3D. In particolare, le prime tre fasi vengono ripetute fino a quando i parametri del modello vengono perfezionati per ottenere prestazioni ottimali nelle condizioni al contorno specificate.
L’approccio metodologico è stato impiegato in diverse applicazioni e relativi casi studio che nello specifico implementano la metodologia di base riguardo gli aspetti delle performance termiche, del riciclo di materiali come materie prime, della sostenibilità e degli impatti sull’ambiente dei processi costruttivi. Tra le diverse caratteristiche prestazionali (acustiche, strutturali, di impatto ambientale, di ciclo di vita, ecc.) che un componente edilizio deve soddisfare, i casi di studio in esame si concentrano sul soddisfacimento delle prestazioni termiche. Questa caratteristica è fondamentale per l'utilizzo effettivo dei prodotti edilizi progettati. Inoltre, le applicazioni hanno lo scopo di dimostrare la correlazione che può verificarsi tra la geometria e il percorso termico che influisce sulla trasmittanza totale di un involucro e quindi il vantaggio concreto che può derivare dall'uso della stampa 3D, che consente un elevato grado di libertà geometrica.
Un aspetto comune dei casi di studio sviluppati riguarda l'uso della stampa 3D come tecnologia per la prefabbricazione di componenti edilizi piuttosto che per la produzione in loco di edifici su larga scala, fornendo esempi di impiego.
Le applicazioni affrontate mirano a rendere sempre più automatizzato il processo di ottimizzazione dei parametri, in funzione delle condizioni al contorno. Partendo da un metodo iterativo manuale, che consiste nel modificare i parametri e poi ripetere le simulazioni, è stato sviluppato un flusso di lavoro che consente di effettuare simulazioni automatiche al variare dei parametri fino al raggiungimento dell'obiettivo.
Infine, l'approccio è stato adottato per un lavoro sperimentale di sviluppo e prototipazione di un sistema di involucro costituito da elementi cementizi prefabbricabili con stampa 3D. Una fase preliminare si è concentrata sulla modifica di una miscela cementizia per migliorarne le prestazioni in base ai requisiti di stampa. Inoltre, sono stati condotti test di stampa 3D per adattare la geometria iniziale e ottimizzarla rispetto ai requisiti della stampante impiegata. Infine, è stato realizzato il prototipo di un elemento in scala reale.To date, the construction industry is globally among the most impactful on the environment. A look into the past may lead to questioning about how housing systems have been transformed and how to cope with current critical issues. A common factor in past architectural styles for each location has always been the adaptation to the climate and the natural environment. To address the heat, cold, and winds of the site where they were to be built, building types were adapted with specific shapes and materials, often sourced locally. As a result, the transformation of constructions over the centuries has given a varied architectural landscape, unique to each region of the world.
This trend was reversed starting from the Second Industrial Revolution when standardized construction techniques replaced traditional and local methods. The use of reinforced concrete spread across all latitudes, influencing architectural forms, which were no longer adapted to the local climate. To meet the thermo-hygrometric requirements of indoor environments, increasingly widespread thermal conditioning systems were used. This made it possible for the same building to be constructed anywhere in the world. The consequences of this approach are among the causes of the current significant environmental impact of the construction sector. Indeed, the reduced use of local materials, increased consumption of raw materials, increased transportation of construction elements, and higher energy consumption all contribute to increased emissions. Another aspect that has been irreversibly neglected in the last century is the variety of architectural forms and their corresponding adaptation to the surrounding environment.
During recent decades, the technological progress of the construction industry has been very slow compared to other industrial sectors, which have increased productivity and efficiency by adopting innovative technologies. 3D printing is a production technology already established in other industrial sectors, and the interest in using such technology for construction has rapidly grown, proving to be one of the most promising technologies to innovate the construction sector. Its potential includes cost reduction, reduced energy consumption, lower material waste, automation of construction processes (thereby reducing risks for workers and the chance of errors), increased productivity, and greater efficiency. Moreover, 3D printing technology offers a greater degree of freedom in architectural forms, allowing curved and three-dimensional shapes to be realized more easily compared to traditional technologies. This architectural freedom could provide a solution to the search for a sustainable construction approach, as it would allow for a renewed connection between architectural forms and the surrounding environment.
The primary goal of this thesis is to explore the possibilities that 3D printing offers to the construction industry. Specifically, by studying the evolution of 3D printing in construction both from a market and scientific innovation perspective, the current limitations to the widespread applicability of 3D printing for building construction have been highlighted. For 3D printing to become an established technology in construction, the printed products must be competitive in terms of performance within the existing market. To overcome some of these limitations, this study proposes a methodological approach to support the design of building components, based on the parameterization of digital models and the iterative analysis of their performance. This allows for the creation of adaptable building elements suitable for different boundary conditions and prefabricated using 3D printing technology. The proposed methodology follows a four-phase iterative process: I. design development and parametric modelling; II. definition of performance criteria and boundary conditions; III. performance simulation and parameter identification; IV. production with 3D printing. In particular, the first three phases are repeated until the model's parameters are refined to achieve optimal performance under the specified conditions.
The methodological approach has been employed in various applications and related case studies that specifically implement the basic methodology regarding aspects of thermal performance, recycling of raw materials, sustainability, and the environmental impact of construction processes. Among the various performance characteristics (acoustic, structural, environmental impact, lifecycle, etc.) that a building component must meet, the case studies focus on fulfilling thermal performance requirements. This characteristic is crucial for the effective use of the designed building products. Additionally, the applications aim to demonstrate the correlation that can occur between geometry and the thermal path that affects the overall transmittance of an envelope, and thus the tangible advantage that can result from the use of 3D printing, which allows for a high degree of geometric freedom.
A common feature of the developed case studies is the use of 3D printing as a technology for the prefabrication of building components, rather than for the large-scale on-site production of buildings, providing examples of this use.
The applications aim to increasingly automate the parameter efficiency process based on boundary conditions. Starting from a manual iterative method, which involves modifying parameters and then repeating simulations, a workflow was developed to allow for automatic simulations as parameters vary until the goal is reached.
Finally, the approach was adopted for experimental work focused on the development and prototyping of an envelope system made of prefabricated cementitious elements using 3D printing. A preliminary phase focused on modifying a cementitious mix to improve its performance according to printing requirements. Additionally, 3D printing tests were conducted to adapt and optimize the initial geometry to meet the requirements of the employed printer. Ultimately, a full-scale prototype element was produced
Exploring Metabolic Shifts in Kidney Cancer and Non-Cancer Cells Under Pro- and Anti-Apoptotic Treatments Using NMR Metabolomics
Get PDFThis study investigates the metabolic responses of cancerous (RCC) and non-cancerous (HK2) kidney cells to treatment with Staurosporine (STAU), which has a pro-apoptotic effect, and Bongkrekic acid (BKA), which has an anti-apoptotic effect, individually and in combination, using 1H NMR metabolomics to identify metabolite markers linked to mitochondrial apoptotic pathways. BKA had minimal metabolic effects in RCC cells, suggesting its role in preserving mitochondrial function without significantly altering metabolic pathways. In contrast, STAU induced substantial metabolic reprogramming in RCC cells, disrupting energy production, redox balance, and biosynthesis, thereby triggering apoptotic pathways. The combined treatment of BKA and STAU primarily mirrored the effects of STAU alone, with BKA showing little capacity to counteract the pro-apoptotic effects. In non-cancerous HK2 cells, the metabolic alterations were far less pronounced, highlighting key differences in the metabolic responses of cancerous and non-cancerous cells. RCC cells displayed greater metabolic flexibility, while HK2 cells maintained a more regulated metabolic state. These findings emphasize the potential for targeting cancer-specific metabolic vulnerabilities while sparing non-cancerous cells, underscoring the value of metabolomics in understanding apoptotic and anti-apoptotic mechanisms. Future studies should validate these results in vivo and explore their potential for personalized treatment strategies
Integrating “nature” in the water-energy-food Nexus: Current perspectives and future directions
No full textA User Based HVAC System Management Through Blockchain Technology and Model Predictive Control
No full textThis paper introduces an innovative approach to designing a user-based Heating, Ventilation, and Air-Conditioning (HVAC) system management connected with the District Energy Management System. By classifying the users into dynamic energy consumption classes to reward energy efficiency and penalize excessive use, users can modify their behavior to pass to a less expensive and more virtuous consumption class. To this aim, a blockchain platform determines the rewards and penalties and, by a K-means clustering algorithm, categorizes users into respective groups. Then, a Class Follower Problem is formulated and solved by a Model Predictive Control (MPC) strategy integrated with a Long Short-Term Memory network as a predictive model. If the users follow the suggestions proposed by the controller, i.e., the thermostat set-points and the time intervals in which the HVAC system must be switched off or on, the users can be located in a more virtuous consumption class. A case study conducted within an energy district in Bari (Italy) shows how the proposed architectural framework tuned thermal regulation in intelligent buildings while concurrently achieving energy optimization