139 research outputs found
Ghost towns in the making. Addressing depopulation and marginalization in Piemontese mountain communities
No full textLAUREA MAGISTRALESebbene il titolo alluda al paranormale, questa tesi mette più in discussione gli aspetti tangibili di un luogo abbandonato. Lo studio si occupa delle ragioni del declino della popolazione, ma soprattutto di trovare il modo più adeguato per riorganizzare e riterritorializzare questi luoghi emarginati.
ci sono tre categorie di tipi di fantasmi identificati dai motivi dell’abbandono; città fantasma per disastro, città fantasma per pianificazione e focus dello studio sarà intorno alla terza categoria città fantasma per declino. Questa categoria di solito coinvolge un profilo urbano descritto come piccola città o villaggio che si stava comportando in modo accettabile con l’agricoltura, la pastorale o l’estrazione mineraria come attività economiche comuni. lo spopolamento è graduale e richiede più decenni, con ragioni specifiche legate all’esaurimento delle risorse, alla ricerca di opportunità di lavoro in città o come conseguenza dell’industrializzazione.
In Piemonte la maggior parte dei paesi fantasma erano borghi agrario / pastorali e vennero gradualmente abbandonati per una più redditizia promessa di vita in città o in conseguenza di danni strutturali dopo la seconda guerra mondiale.
L’anno 2020 ha visto uno stravolgimento della vita cittadina che è stata una ripercussione del decretato allontanamento sociale. Il regolamento di allontanamento sociale è stata progettata per ridurre la contaminazione attraverso il contatto diretto o indiretto, di conseguenza ha trasformato gli aspetti fisici, mentali, occupazionali, sociali e ambientali della vita delle persone. Queste mutate circostanze indicano miglioramenti pratici della pianificazione e progettazione delle comunità viventi. La pandemia ha già accelerato una serie di tendenze preesistenti nello spazio di lavoro digitale. Il mondo sta vivendo una crescente flessibilità nel mercato del lavoro che consentirà agli individui una maggiore libertà di scegliere il tipo di urbanità che meglio si adatta alle proprie esigenze.
Questa tesi cerca di recuperare i valori persi usando lo slancio e la leva del nuovo stile di vita costretto dalla quarantena.
In questo modello le città abbandonate subiranno un processo di rinnovamento e rigenerazione urbana per diventare sussidiarie residenziali, economiche ed ecologiche di un nucleo sociale ed economico; la città.Although the title alludes to the paranormal this thesis questions the tangible aspects of an abandoned place. The study is concerned with the reasons of population decline but most importantly with finding the most adaptable way to re-urbanize and reterritorialize these marginalized places.
There are three categories of ghost towns identified by the reasons of abandonment; ghost town by disaster, ghost town by planning and focus of the study will be around the third category ghost town by decline. This category usually involves an urban profile described as small town or village that was performing acceptably with agriculture, pastoral or mining as common economic activities. The depopulation is gradual and takes multiple decades , with specific reasons concerned with resource exhaustion, searching for job opportunities in the city or as a consequence of industrialization.
In Piemonte the majority of ghost towns where agrarian/pastoral villages and were gradually abandoned for a more lucrative promise of life in the city or as a consequence of structural damages after WWII.
The year of 2020 has seen a disrupted city life which was a repercussion of the decreed social distancing. The regulations of social distancing were designed to reduce the contamination through direct or indirect contact, as a consequence it has transformed the physical, mental, occupational, social and environmental aspects of people’s lives. These changed circumstances point to practical improvements of the planning and design of living communities. Already the pandemic has accelerated a range of pre-existing trends in the digital workspace. The world is experiencing an increasing flexibility within the labour market which will allow more freedom for individuals to choose the type of urbanity that best suits their preferred lifestyle.
This thesis seeks to salvage the lost values of depopulated alpine communities in piemonte using the momentum and the leverage of the new lifestyle compelled by the quarantine of 2020.
In this model the abandoned towns will undergo an urban renewal and regeneration process to be able to attract new residents and become more socially economically and ecologically viable
Numerical investigation of turbulent flow heat transfer and pressure drop of AL2O3/water nanofluid in helically coiled tubes
No full textPassive convective heat transfer enhancement can be achieved by improving the thermo-physical properties of the working fluid, changing flow geometry or both. This work presents a numerical study to investigate the combined effect of using helical coils and nanofluids on the heat transfer characteristics and pressure losses in turbulent flow regime. The developed computational fluid dynamics models were validated against published experimental data and empirical correlations. Results have shown that combining the effects of alumina (Al2O3) nanoparticles and tube coiling could enhance the heat transfer coefficient by up to 60% compared with that of pure water in straight tube at the same Reynolds number. Also, results showed that the pressure drop in helical coils using Al2O3 nanofluid for volume fraction of 3% was six times that of water in straight tubes (80% of the pressure drop increase is due to nanoparticles addition), while the effect of Reynolds number on the pressure drop penalty factor was found to be insignificant
Reinventing Llobregat river: a nature-based solutions approach for river regeneration
No full textLAUREA MAGISTRALEIl fiume Llobregat, una fonte d'acqua fondamentale per la vivace città di Barcellona, ha assistito a un graduale declino della sua salute ecologica nel corso degli anni. La rapida industrializzazione e l'ampio sviluppo delle infrastrutture di trasporto lungo le sue sponde, insieme al crescente impatto dei cambiamenti climatici, hanno eroso collettivamente la biodiversità del fiume. Questa tesi cerca di affrontare questo problema ambientale urgente proponendo una strategia olistica per ripristinare il fiume Llobregat e nutrire i suoi ecosistemi. Questa tesi cerca di utilizzare le soluzioni basate sulla natura e di sfruttare il loro potenziale, allineandole con gli Obiettivi di Sviluppo Sostenibile (SDGs) per rinvigorire il fiume Llobregat. Attraverso un approccio globale e interdisciplinare, aspira a far rivivere le sponde del fiume, alimentando la biodiversità e migliorando i servizi ecosistemici a beneficio sia dell'ambiente che della popolazione di Barcellona.
La ricerca si concentra non solo sui benefici ecologici del ripristino del fiume Lorgat, ma anche sul potenziale di miglioramento della qualità dell'acqua, sulla regolazione del microclima e sul miglioramento delle opportunità ricreative per la comunità locale. Inoltre, il progetto promette di favorire la resilienza alle sfide ambientali future e di facilitare la realizzazione degli SDG.The Llobregat River, a quintessential water source for the vibrant city of Barcelona, has witnessed a gradual decline in its ecological health over the years. The rapid industrialization and extensive transportation infrastructure development along its banks, coupled with the ever increasing impacts of climate change, have collectively eroded the river's biodiversity. This thesis endeavours to address this pressing environmental concern by proposing a holistic strategy for restoring the Llobregat River and nurturing its ecosystems. This thesis seeks to use Nature Based Solutions and harness their potential, aligning them with the Sustainable Development Goals (SDGs) to reinvigorate the Llobregat River. Through a Comprehensive and interdisciplinary approach, it aspires to revive the riverbank, nurturing biodiversity and enhancing ecosystem services for the benefit of both the environment and the people of Barcelona.
The research also focuses not only on the ecological benefits of restoring the Lorgat River, but there is also the potential for enhancing water quality, regulating micro climates, and improving recreational opportunities for the local community. Moreover, it holds the promise of fostering resilience to future environmental challenges and facilitating the realization of SDGs
Adaptive fringe: encourage permeability between the urban outskirts and urban center
No full textLAUREA MAGISTRALECon la continua accelerazione dell’urbanizzazione, lo sviluppo sostenibile è diventato cruciale per affrontare le sfide ambientali urbane. Al giorno d’oggi la continua crescita dei centri urbani sta minando gli equilibri che ci permettono di vivere su questo pianeta. Questa ricerca ha come punto di partenza il paese di Uboldo, in provincia di Varese, in Lombardia e usa metodi e strategie per sviluppare un potenziale inesplorato e promuovere uno stile di vita più sano. In questo contesto, l’importanza degli spazi verdi all’interno di aree urbanizzate è essenziale per arrivare al nostro scopo. Come risultato si otterrà un progetto nel suo insieme, il quale comprende tutte le scale, con un’implementazione sia a livello di tempo che di spazio.
Nella periferia di Uboldo in particolare vi è un problema di frammentazione, di fatti, l’attuale stato della frangia urbana si presenta fortemente separato, creando due mondi distanti sia fisicamente che metaforicamente, il mondo rurale ed il mondo urbano. Il paese, essendo prettamente di origine agricola, si presenta come l’occasione giusta al momento giusto per poter sperimentare un diverso approccio progettuale. Il valore aggiunto sarà dato dall’utilizzo nella strategia di un elemento come la Frangia Urbana, la quale è vista come strumento in grado di riportare un dialogo tra i due mondi. La creazione di interferenze faranno si che i due mondi si scontrino con il fine ultimo di creare un momento, nello specifico, un momento di complicità.
La diversificazione degli interventi insieme alla volontà di riportare alla luce i valori tangibili e intangibili porterà ad avere come risultato finale un insieme di paesaggi che non solo saranno preservati ma anche animati ed amplificati nel loro insieme.
Infine, la ricerca mira ad affrontare questa relazione profonda che esiste tra paesaggio naturale e centro città urbanizzato, offrendosi come punto di vista differente e lasciando indizi importanti per interventi che potrebbero essere fatti sul campo, contribuendo a rendere Uboldo una città dal quale diffondere idee e trasformandola in una città di riferimento sulla scena regionale e perchè no, in futuro, anche nazionale.With the continuous acceleration of urbanization, sustainable development has become crucial in addressing urban environmental challenges. The continuous growth of urban centers is undermining the balances that allow us to live on this planet. This research has as its starting point the town of Uboldo, in Varese Province, in Lombardy, use methods and strategies to develop an unexplored potential. In this context, the importance of green spaces within urbanized areas is essential to achieve our goal. As a result, the paper fits its goal on a city-wide scale and on its study as a whole.
In the periphery of Uboldo, the fragmentation is clearly visible. The actual state of the urban fringe creates a clear cut between these two worlds that do not meet, both physically and metaphorically, the rural and the urban world. As a medium size municipality within a mostly agrarian context, it is of great interest to experiment with a different approach in urban planning for the expansion of the city. The plus-value will be given by the use in the design strategy of an element such as the Urban Fringe, which is seen as a tool able to bring back a dialogue between these two worlds. The creation of interference will cause the two worlds to collide with the goal of creating a moment, or better, a bonding moment.
The diversification of the interventions altogether with the desire to bring back to light the tangible and intangible values will lead to the result of a set of landscapes that will not only be preserved but also animated and amplified as a whole. A set of strategies and interventions that, applied throughout time and space, will make Uboldo a town in which the quality of the urban environment and the quality of life of residents will be improved.
In the end, the research strives to address this deep relationship that exists between natural landscape and urbanized city center, offering itself as a different point of view and leaving important clues for interventions that could be done in the fields, contributing to make Uboldo a city from which to spread ideas and turn it into a reference city on the regional scene and why not, in the future, also national
Iron and hepatitis C: What can we learn from thalassemia major?
No full text[No abstract available]Alexander J, 2007, LIVER INT, V27, P268, DOI 10.1111-j.1478-3231.2007.01449.x; Di Bisceglie AM, 2000, HEPATOLOGY, V32, P135, DOI 10.1053-jhep.2000.8700; Herrera JL, 1999, AM J GASTROENTEROL, V94, P3571; Tsai NCS, 1997, AM J GASTROENTEROL, V92, P1831; VanThiel DH, 1996, HEPATO-GASTROENTEROL, V43, P155722
Unveiling the Intrinsic Catalytic Activities of Single‐Gold‐Nanoparticle‐Based Enzyme Mimetics
No full textUnveiling the Intrinsic Catalytic Activities of Single‐Gold‐Nanoparticle‐Based Enzyme Mimetics
No full textSimulating the impacts of lean practices on supply chain performance, in the context of Industry 4.0
No full textLAUREA MAGISTRALEL'attuale contesto della pianificazione della catena di fornitura (supply chain), che accompagna i progressi verso l'Industria 4.0, è caratterizzato da elevati livelli di incertezza sia nella domanda che nell'offerta, accorciando i cicli di vita dei prodotti, aumentando le richieste di personalizzazione dei prodotti e aumentando i rischi di interruzione. Mentre la maggior parte della recente letteratura sull'industria 4.0 sollecita intensamente l'adozione di analisi dei dati, Internet delle cose (IoT), sistemi autonomi, sistemi cyber-fisici (CPS) e intelligenza artificiale (AI) per ottenere migliori prestazioni della catena di fornitura e mitigare l'effetto frusta (bullwhip); questo studio cerca di indagare se pratiche a basso costo e di bassa complessità, come: riduzione della variabilità, riduzione dei tempi di installazione, riduzione delle dimensioni del lotto e maggiore frequenza di spedizione delle catene di approvvigionamento magre (lean supply chains), sono in grado di ottenere effetti simili sulle prestazioni della catena di approvvigionamento, in pieno, o almeno in parte.
Per essere in grado di studiare tali effetti, è stato sviluppato un modello di "simulazione di eventi discreti" di una catena di fornitura seriale a tre stadi, multiprodotto, con un alto livello di variabilità della domanda. Sono stati progettati ed eseguiti due esperimenti fattoriali, seguiti da analisi della varianza (ANOVA) delle uscite sperimentali. In un esperimento, le prestazioni della catena di approvvigionamento modellata sono state testate in base a diversi livelli di variabilità del processo, tempi di installazione, dimensioni dei lotti e frequenze di spedizione, mentre nel secondo, le prestazioni della catena di approvvigionamento sono state testate in base a diversi livelli interagenti di media dei tempi di elaborazione (o velocità di elaborazione) e variabilità dei tempi di elaborazione. I risultati hanno mostrato che la riduzione delle dimensioni del lotto ha grandi effetti sulla riduzione dell'inventario della catena di approvvigionamento totale, aumentando il livello del servizio clienti e riducendo l’effetto bullwhip. È stato riscontrato che la riduzione dei tempi di installazione riduce significativamente il tempo di consegna totale della supply chain. e riduce anche il tempo di ciclo dell'ordine del cliente; mentre aumentare la frequenza di spedizione ha avuto l'effetto di ridurre notevolmente il tempo di ciclo dell'ordine per il cliente. D'altra parte, la riduzione della variabilità dei tempi di elaborazione è sembrata significativa solo su due delle sei misure prestazionali osservate: il tempo di consegna totale della catena di approvvigionamento e la saturazione media delle fabbriche, diminuendole leggermente entrambe. Un'importante indicazione del primo esperimento era evidenziare l'importanza non solo dei singoli fattori, ma anche delle loro "interazioni", in quanto l'interazione tra il tempo di setup e la dimensione del lotto, in particolare, ha dimostrato di essere significativa su tutte gli indicatori di prestazione misurati. Inoltre, i risultati del secondo esperimento hanno sottolineato che, in un compromesso tra la riduzione dei rifiuti o le attività di miglioramento continuo che influenzano la media del processo e le attività che influenzano la variabilità, quelli che influenzano la media del processo dovrebbero essere fortemente favoriti.
Si è concluso che le pratiche di Lean SC possono avere notevoli ripercussioni sul miglioramento delle prestazioni della fornitura, se si riscontra un equilibrio o uno scambio ottimale tra tali pratiche, in linea con la struttura del mercato SC e gli obiettivi strategici. Gli esperimenti condotti con variabilità della domanda elevata e vari livelli di variabilità del tempo di elaborazione hanno mostrato che alcune pratiche snelle possono migliorare alcune prestazioni di SC e peggiorare altre prestazioni e altre pratiche lean hanno l'effetto opposto. È pertanto necessario ricercare il miglior equilibrio o compromesso tra tali pratiche, alla luce degli obiettivi competitivi delle imprese di SC.The current context of supply chain planning, accompanying the advancements towards Industry 4.0 is characterized by high levels of uncertainty in both supply and demand, shortening product life cycles, increasing demands for products customization, and increasing disruption risks. While most of the recent literature about Industry 4.0 intensively urges for the adoption of data analytics, the internet of things (IoT), autonomous systems, cyber-physical systems (CPS) and artificial intelligence (AI) to achieve better supply chain performances and mitigate the bullwhip effect; this study tries to investigate if low cost and low complexity practices, such as: variability reduction, setup time reduction, lot size reduction and higher shipping frequency of lean supply chains are able to achieve similar impacts on supply chain performances, in full, or at least in part.
To be able to investigate such effects, a ‘discrete-event simulation’ model, of a three-stage and multi-product serial supply chain with high level of demand variability, was developed. Two factorial experiments were designed and performed, followed by analysis of variance (ANOVA) of the experimental outputs. In one experiment, the performance of the modelled supply chain was tested under different levels of process variability, setup times, lot sizes and shipment frequencies, while in the second, the performance of the supply chain was tested under different interacting levels of processing time mean (or processing speed) and processing time variability. The results showed that lot size reduction have great effects on decreasing the total SC inventory, increasing the customer service level and decreasing the bullwhip effect. Setup time reduction was found to be significantly reducing the total SC lead time and also reducing the order cycle time of the customer; while increasing the shipping frequency had the effect of decreasing the order cycle time (OCT) for the customer remarkably. On the other hand, variability reduction of the processing times appeared only to be significant on two of the six performance measures observed: the total supply chain lead time, and the mean factories saturation, slightly decreasing both of them. An important indication of the first experiment was pointing out the importance, not only of single factors, but also their ‘interactions’, as the interaction between the setup time and the lot size, in particular, showed to be significant on all the measured performance indicators. Furthermore, results of the second experiment pointed out that, in a trade-off between waste reduction or continuous improvement activities that affect the process mean and activities that affect the variability, those who affect the process mean should be highly favored.
It was concluded Lean SC practices can have remarkable impacts on improving the supply performance, if the optimal balance or trade-off between those practices is found, in alignment with the SC market structure and strategic goals. The experiments performed under high demand variability and varying levels of processing time variability showed that some lean practices can improve some SC performances, while worsen other performances, and other lean practices have the opposite effect. It thus necessary to seek the best balance or trade-off between those practices, in the light of the competitive goals of the SC firms
The Current State of Artificial Intelligence on Detecting Pulmonary Embolism via Computerised Tomography Pulmonary Angiogram: A Systematic Review.
No full textCopyright: © 2025 The Author(s).
https://creativecommons.org/licenses/by-nc/4.0/Pulmonary embolism (PE) is a life-threatening condition with significant diagnostic challenges due to high rates of missed or delayed detection. Computed tomography pulmonary angiography (CTPA) is the current standard for diagnosing PE, however, demand for imaging places strain on healthcare systems and increases error rates. This systematic review aims to assess the diagnostic accuracy and clinical applicability of artificial intelligence (AI)-based models for PE detection on CTPA, exploring their potential to enhance diagnostic reliability and efficiency across clinical settings. A systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Excerpta Medica Database (EMBASE), Medical Literature Analysis and Retrieval System Online (MEDLINE), Cochrane, PubMed, and Google Scholar were searched for original articles from inception to September 2024. Articles were included if they reported successful AI integration, whether partial or full, alongside CTPA scans for PE detection in patients. The literature search identified 919 articles, with 745 remaining after duplicate removal. Following rigorous screening and appraisal aligned with inclusion and exclusion criteria, 12 studies were included in the final analysis. A total of three primary AI modalities emerged: convolutional neural networks (CNNs), segmentation models, and natural language processing (NLP), collectively used in the analysis of 341,112 radiographic images. CNNs were the most frequently applied modality in this review. Models such as AdaBoost and EmbNet have demonstrated high sensitivity, with EmbNet achieving 88-90.9% per scan and reducing false positives to 0.45 per scan. AI shows significant promise as a diagnostic tool for identifying PE on CTPA scans, particularly when combined with other forms of clinical data. However, challenges remain, including ensuring generalisability, addressing potential bias, and conducting rigorous external validation. Variability in study methodologies and the lack of standardised reporting of key metrics complicate comparisons. Future research must focus on refining models, improving peripheral emboli detection, and validating performance across diverse settings to realise AI's potential fully
New and renewable energy and environmental engineering
No full textThere is an acute scarcity of potable water in many parts of the world, and especially in most of the Middle East region. Important advances have been made in desalination technology but its wide application is restricted by relatively high capital and input energy costs, even when solar energy is used. Until recently, flat-plate solar collectors have usually been employed to distill water in compact desalination systems. Currently, it is possible to replace these collectors by the more advanced evacuated tube collectors, which are now available on the market at a similar price. The research which is concerned with the development of a novel small scale solar water desalination technology, consists of experimental and theoretical investigations of the operation of a multi stage solar still desalination system coupled with a heat pipe evacuated tube solar collector with an aperture area of about 1.7 m(^2). The multi stage still was tested to recover latent heat from the evaporation and condensation processes in each of its four stages. A number of experimental tests were carried out using a laboratory rig to investigate its water production capacity. Solar radiation (insolation) during a mid-summer day in the Middle East region was simulated by an array of 110 halogen flood lights. Computational Fluid Dynamics (CFD) modeling of the evaporation and condensation processes in one of the still's stages was conducted using FLUENT 6.2 software. The simulation results demonstrate the importance of the various parameters affecting the total production rate of the solar still and provide detailed information on the temperature distribution and condensate formation inside the solar still. However, it was found that the CFD technique at this stage does not provide accurate quantitative predictions and results obtained can be used only for qualitative analysis. Hence, the use of a lumped parameter mathematical model was preferred for analysis and design purpose. A lumped parameter model has been developed to describe the system's operation. It consists of a system of ordinary differential equations of energy and mass conservation written for each stage of the still. A MATLAB computer program was written to solve the system of governing equations to simulate the evaporation and condensation processes and the experimental results were used to validate numerical predictions. The experimental and theoretical values for the total daily distillate output were found to be closely correlated. The test results demonstrate that the system produces about 9 kg of clean water per day and has a distillation efficiency of 90%. The overall efficiency is 33% due to the presence of heat losses in the system. However, this level of efficiency is greater of that for conventional solar stills. Following the experimental calibration of the lumped parameter model, this was used for determination of rational design parameters of the still and it was demonstrated that the performance of the system could be considerably improved to produce 11 kg/m(^2) of water per day if the number of stages and evaporation area were 4 and 1 m(^2), respectively. A water quality analysis was performed for the distilled water and the levels of total dissolved solids, electrical conductivity and pH were well within the range defined by the World Health Organization guidelines for drinking water. An economic study was also conducted for the system and it was shown that the distilled water costs of 0.016 US$/litre with a payback period of 6 months in the Middle East region conditions. This research demonstrates, empirically and theoretically, the potential role in the field of solar desalination of the multistage solar still coupled to the evacuated tube solar collector. Not only is this system a promising new technology but it could prove to be particularly appropriate in remote and rural areas. Simultaneously this system also uses a completely clean energy source and contributes to tackling environmental pollution, global carbon emissions and climate change problems
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