930 resultados para new type AgInSbtTe phase change films
Resumo:
This dissertation is related to the studies of functionalized nanoparticles for self-assembly and as controlled drug delivery system. The whole topic is composed of two parts. In the first part, the research was conducted to design and synthesize a new type of ionic peptide-functionalized copolymer conjugates for self-assembly into nanoparticle fibers and 3D scaffolds with the ability of multi-drug loading and governing the release rate of each drug for tissue engineering. The self-assembly study confirmed that such peptide-functionalized amphiphilic copolymers underwent different self-assembly behavior. The bigger nanoparticles were more easily assembled into nanoparticle fibers and 3D scaffolds with larger pore size, while the smaller nanoparticle underwent faster self-assembly to form more compact 3D scaffolds with smaller porosity but more stable structure. Controlled release studies confirmed the ability of governing simultaneous release of different model drugs with independent release rate from a same scaffold. Cytotoxicity tests showed that all synthesized peptides, copolymers and peptide-copolymer conjugates were biocompatible with SW-620 cell lines and NIH3T3 cell lines. This new type of self-assembled scaffolds combined the advantages of peptide nanofibers and versatile controlled release of polymeric nanoparticles to achieve simultaneous multi-drug loading and controlled release of each drug, uniform distribution and flexibility of hydrogel scaffolds. The investigations in second part were first to design and synthesize organic biocide-loaded nanoparticles for low-leaching wood preservation using a cost-effective one-pot method to synthesize amphiphilic chitosan-g-PMMA nanoparticles loading with ~25-28 wt.% of the fungicide tebuconazole with particle size of ~100 nm diameter by FESEM. FESEM analysis confirmed efficient penetration of nanoparticles throughout the treated wooden stake with dimension of 19 × 19 × 455 mm^3. Leaching studies showed that biocide introduced into sapwood via nanoparticles leached only ~9% compared with the amount leached from tebuconazole solution-treated control, while soil jar tests showed that the nanoparticle-treated wood blocks were effectively protected from biological decay tested against G. trabeum, a brown rot fungus. Copper oxide nanoparticles with and without polymer stabilizers were also investigated to use as inorganic wood preservatives to clarify the factor affecting copper leaching from treated wood. Copper oxide nanoparticles with uniform diameters of ~10 nm and ~50 nm were prepared, and the leachates from southern pine sapwood treated with these nanoparticles were analyzed. It was found by TEM and EDS analysis that significant numbers of nanoparticles leached from the treated wood. The 50 nm nanoparticles leached slightly less than a soluble copper salt control, but 10 nm nanoparticles leached substantially more than the control. The effect of polymer stabilizers on nanoparticle leaching was also investigated. Results showed that polymer stabilizers increased leaching. The trends showed that nanoparticle size was a major factor in copper leaching.
Resumo:
Ce mémoire de recherche-création est accompagné du court métrage «Tala». Pour visionner en ligne : vimeo.com/ondemand/talapierphilippechevigny
Resumo:
As nuclear energy systems become more advanced, the materials encompassing them need to perform at higher temperatures for longer periods of time. In this Master’s thesis we experiment with an oxide dispersion strengthened (ODS) austenitic steel that has been recently developed. ODS materials have a small concentration of nano oxide particles dispersed in their matrix, and typically have higher strength and better extreme temperature creep resistance characteristics than ordinary steels. However, no ODS materials have ever been installed in a commercial power reactor to date. Being a newer research material, there are many unanswered phenomena that need to be addressed regarding the performance under irradiation. Furthermore, due to the ODS material traditionally needing to follow a powder metallurgy fabrication route, there are many processing parameters that need to be optimized before achieving a nuclear grade material specification. In this Master’s thesis we explore the development of a novel ODS processing technology conducted in Beijing, China, to produce solutionized bulk ODS samples with ~97% theoretical density. This is done using relatively low temperatures and ultra high pressure (UHP) equipment, to compact the mechanically alloyed (MA) steel powder into bulk samples without any thermal phase change influence or oxide precipitation. By having solutionized bulk ODS samples, transmission electron microscopy (TEM) observation of nano oxide precipitation within the steel material can be studied by applying post heat treatments. These types of samples will be very useful to the science and engineering community, to answer questions regarding material powder compacting, oxide synthesis, and performance. Subsequent analysis performed at Queen’s University included X-ray diffraction (XRD) and inductively coupled plasma optical emission spectrometry (ICP-OES). Additional TEM in-situ 1MeV Kr2+ irradiation experiments coupled with energy dispersive X-ray (EDX) techniques, were also performed on large (200nm+) non-stoichiometric oxides embedded within the austenite steel grains, in an attempt to quantify the elemental compositional changes during high temperature (520oC) heavy ion irradiation.
Resumo:
Mobile and wireless networks have long exploited mobility predictions, focused on predicting the future location of given users, to perform more efficient network resource management. In this paper, we present a new approach in which we provide predictions as a probability distribution of the likelihood of moving to a set of future locations. This approach provides wireless services a greater amount of knowledge and enables them to perform more effectively. We present a framework for the evaluation of this new type of predictor, and develop 2 new predictors, HEM and G-Stat. We evaluate our predictors accuracy in predicting future cells for mobile users, using two large geolocation data sets, from MDC [11], [12] and Crawdad [13]. We show that our predictors can successfully predict with as low as an average 2.2% inaccuracy in certain scenarios.
Resumo:
Fire has been always a major concern for designers of steel and concrete structures. Designing fire-resistant structural elements is not an easy task due to several limitations such as the lack of fire-resistant construction materials. Concrete reinforcement cover and external insulation are the most commonly adopted systems to protect concrete and steel from overheating, while spalling of concrete is minimised by using HPFRC instead of standard concrete. Although these methodologies work very well for low rise concrete structures, this is not the case for high-rise and inaccessible buildings where fire loading is much longer. Fire can permanently damage structures that cost a lot of money. This is unsafe and can lead to loss of life. In this research, the author proposes a new type of main reinforcement for concrete structures which can provide better fire-resistance than steel or FRP re-bars. This consists of continuous braided fibre rope, generally made from fire-resistant materials such as carbon or glass fibre. These fibres have excellent tensile strengths, sometimes in excess of ten times greater than steel. In addition to fire-resistance, these ropes can produce lighter and corrosive resistant structures. Avoiding the use of expensive resin binders, fibres are easily bound together using braiding techniques, ensuring that tensile stress is evenly distributed throughout the reinforcement. In order to consider braided ropes as a form of reinforcement it is first necessary to establish the mechanical performance at room temperature and investigate the pull-out resistance for both unribbed and ribbed ropes. Ribbing of ropes was achieved by braiding the rope over a series of glass beads. Adhesion between the rope and concrete was drastically improved due to ribbing, and further improved by pre-stressing ropes and reducing the slacked fibres. Two types of material have been considered for the ropes: carbon and aramid. An implicit finite element approach is proposed to model braided fibres using Total Lagrangian formulation, based on the theory of small strains and large rotations. Modelling tows and strands as elastic transversely isotropic materials was a good assumption when stiff and brittle fibres such as carbon and glass fibres are considered. The rope-to-concrete and strand-to-strand bond interaction/adhesion was numerically simulated using newly proposed hierarchical higher order interface elements. Elastic and linear damage cohesive models were used effectively to simulate non-penetrative 'free' sliding interaction between strands, and the adhesion between ropes and concrete respectively. Numerical simulation showed similar de-bonding features when compared with experimental pull-out results of braided ribbed rope reinforced concrete.
Resumo:
The paper is about the simulation of malfunctions in an onshore wind energy conversion system powered by a doubly fed induction generator with a two-level power converter, handling only the slip power. These malfunctions are analysed in order to be able to investigate the impact in the wind power system behaviour by comparison before, during and after the malfunctions. The malfunctions considered in the simulation includes are localized in the DC-link of the converter and in the phase change in rectifier.
Resumo:
The aim of this study was to characterize the reproductive seasonality during the period of one year in Saanen goats managed in southeastern Brazil These results endorse hormonal methods (estrus synchronization and induction of synchronized estrus) or natural (male effect, flushing or light treatment) more appropriate according to the time of year in the region. Saanen goats, managed under tropical climate in southeastern Brazil, have a breeding season set from March until mid-August with the transitional phase to the anestrus in September. It is extends to mid-December at the new one transition phase for the reproductive season in March.
Resumo:
El desarrollo tecnológico posibilita el desarrollo de la educación y de América Latina. Internet ha generado una universidad de nuevo tipo, impulsando un desarrollo cultural y social sin precedentes, que debe ser universal y equitativo con pleno respeto a la diversidad cultural y a los derechos humanos.AbstractThe technological development enables the development of education and development of Latin America. Internet has generated a University of new type, prompting an unprecedented social and cultural development that should be universal and fair, with full respect to the cultural diversity and human rights.
Resumo:
This thesis focuses on the dynamics of underactuated cable-driven parallel robots (UACDPRs), including various aspects of robotic theory and practice, such as workspace computation, parameter identification, and trajectory planning. After a brief introduction to CDPRs, UACDPR kinematic and dynamic models are analyzed, under the relevant assumption of inextensible cables. The free oscillatory motion of the end-effector (EE), which is a unique feature of underactuated mechanisms, is studied in detail, from both a kinematic and a dynamic perspective. The free (small) oscillations of the EE around equilibria are proved to be harmonic and the corresponding natural oscillation frequencies are analytically computed. UACDPR workspace computation and analysis are then performed. A new performance index is proposed for the analysis of the influence of actuator errors on cable tensions around equilibrium configurations, and a new type of workspace, called tension-error-insensitive, is defined as the set of poses that a UACDPR EE can statically attain even in presence of actuation errors, while preserving tensions between assigned (positive) bounds. EE free oscillations are then employed to conceive a novel procedure aimed at identifying the EE inertial parameters. This approach does not require the use of force or torque measurements. Moreover, a self-calibration procedure for the experimental determination of UACDPR initial cable lengths is developed, which consequently enables the robot to automatically infer the EE initial pose at machine start-up. Lastly, trajectory planning of UACDPRs is investigated. Two alternative methods are proposed, which aim at (i) reducing EE oscillations even when model parameters are uncertain or (ii) eliminate EE oscillations in case model parameters are perfectly known. EE oscillations are reduced in real-time by dynamically scaling a nominal trajectory and filtering it with an input shaper, whereas they can be eliminated if an off-line trajectory is computed that accounts for the system internal dynamics.
Resumo:
Changing or creating an organisation means creating a new process. Each process involves many risks that need to be identified and managed. The main risks considered here are procedural and legal risks. The former are related to the risks of errors that may occur during processes, while the latter are related to the compliance of processes with regulations. Managing the risks implies proposing changes to the processes that allow the desired result: an optimised process. In order to manage a company and optimise it in the best possible way, not only should the organisational aspect, risk management and legal compliance be taken into account, but it is important that they are all analysed simultaneously with the aim of finding the right balance that satisfies them all. This is the aim of this thesis, to provide methods and tools to balance these three characteristics, and to enable this type of optimisation, ICT support is used. This work isn’t a thesis in computer science or law, but rather an interdisciplinary thesis. Most of the work done so far is vertical and in a specific domain. The particularity and aim of this thesis is not to carry out an in-depth analysis of a particular aspect, but rather to combine several important aspects, normally analysed separately, which however have an impact and influence each other. In order to carry out this kind of interdisciplinary analysis, the knowledge base of both areas was involved and the combination and collaboration of different experts in the various fields was necessary. Although the methodology described is generic and can be applied to all sectors, the case study considered is a new type of healthcare service that allows patients in acute disease to be hospitalised to their home. This provide the possibility to perform experiments using real hospital database.
Resumo:
La presente trattazione concerne gli European long-term investment fund, disciplinati dal regolamento UE 2015/760 del 29 aprile 2015, meglio noti come ELTIF, di cui si è inteso indagare i molteplici aspetti che attengono all’operatività degli stessi, dalla genesi sino alla fase della liquidazione. Trattandosi di uno dei più recenti tasselli della composita disciplina europea del risparmio gestito, si è ritenuto opportuno anzitutto prendere le mosse dall’evoluzione della regolamentazione, domestica e comunitaria, della gestione collettiva del risparmio, la quale rappresenta la “cornice” normativa di riferimento entro cui si colloca il veicolo in discorso. Definito il percorso evolutivo della disciplina de qua, si è posta quindi l’attenzione sulla regolamentazione degli ELTIF che, pur migliorabile sotto diversi profili, rappresenta un significativo passo in avanti nel senso della costruzione dell’Unione dei mercati di capitali e del rilancio dell’economia europea. In particolare, l’indagine ha riguardato anzitutto i connotati della nuova fattispecie (carattere europeo, orizzonte temporale di lungo periodo, illiquidità). L’analisi dei tratti fisiognomici è stata funzionale non solo a verificare se essi, nella loro peculiarità, siano o meno idonei a definire un tipo a sé stante di prodotto, ma altresì a valutare in che termini essi producano un effetto conformativo sulla disciplina del prodotto stesso, specie con riferimento alla fase dell’investimento e del disinvestimento. Con l’intento di vagliare l’opportunità di interventi sul dato normativo che mirino ad accrescere l’attrattività degli ELTIF, si è volta quindi l’attenzione alla fase finale della vita del fondo, in quanto l’esiguità della disciplina dettata con riferimento alla liquidazione si espone ad applicazioni dubbie che, in larga parte, lasciano spazio all’autonomia regolamentare del prodotto e, dunque, all’applicazione di discipline nazionali disomogenee; e ciò specie con riferimento a una peculiare ipotesi di liquidazione promossa dagli investitori in conseguenza del mancato soddisfacimento della richiesta di rimborso avanzata.
Resumo:
Regular physical activity (PA) during childhood is associated with physical, mental, emotional and social health benefits. The constant practice of PA is considered one of the best buys available in public health. The World Health Organization (WHO) recommends to perform at least 60 minutes per day of moderate to vigorous PA for children and adolescents in order to obtain health benefits. However, globally, this level of PA is hardly achieved. Children and adolescent who do not reach the recommended levels of PA are defined as physically inactive and nowadays physical inactivity constitutes a new type of pandemic. For this reason, the WHO launched a global action plan addressing physical activity with a goal of reducing physical inactivity in children and youth. The plan also included recommendation to improve individual and community health and contribute to the social, cultural and economic development of all nations. Worldwide, children and adolescents spend a significant amount of time in school and for this reason the school represents a fundamental educational setting that can play a pivotal role increasing students’ PA. Opportunities to be physically active should not be considered purely in relation to when children attend physical education classes but also making physical activity available during the school day, such as physically active lessons, and multicomponent PA interventions. Since school-based PA interventions are quite numerous, the present thesis focused on interventions delivered during school hours and that integrate small doses of PA as part of routine instruction. This type of intervention is called “Active Breaks.” Active Breaks consists of brief 5–15 minutes sessions of PA led by teachers who introduce short bursts of PA into the academic lesson. In light of this the present thesis aims to evaluate the feasibility, efficacy and sustainability of an Active Breaks intervention targeting children to promote PA.
Resumo:
Lo studio mira ad individuare i passaggi salienti dell’evoluzione dello sport inteso come strumento di salute e benessere preventivo, per rinvenire le manifestazioni di questo concetto, con l’obiettivo precipuo di fare emergere l’ossatura legislativa in evoluzione su cui impostare la transizione del sistema delle attività motorie. Partendo dallo studio del dato normativo e giurisprudenziale e con un’ampia analisi dottrinale sullo sfondo, lo studio descrive l’evoluzione legislativa sul tema poggiandosi su considerazioni e risultati di indagini sociologiche e farmacologiche. La creazione della Società Sport e Salute S.p.a. e di un Dipartimento per lo sport ha permesso un’azione diretta al sostegno delle organizzazioni sportive di base e mirata alla promozione di piani per l’implementazione dei corretti stili di vita. Il d.lgs. 38/2021 contiene una serie di norme volte alla valorizzazione dell’importanza anche territoriale degli enti sportivi, che possono favorire questi e i loro partners privati nell’affidamento degli impianti. La nuova figura professionale del chinesiologo rappresenta lo strumento centrale per il rilancio degli enti sportivi, in quanto capace di organizzare nuovi servizi paralleli allo sport e fondamentali in ottica educativa preventiva. L’accresciuta rilevanza del concetto di work-life balance spinge le imprese alla creazione di nuove politiche di welfare per i lavoratori attraverso investimenti per la riqualificazione dell’impiantistica, in modo da favorire gli enti che li gestiscono collaborando per offrire maggiori servizi anche al territorio. Il legislatore ha creato uno strato normativo volto a permettere un’azione diretta dello Stato nella promozione dello sport sociale e volto all’implementazione dei corretti stili di vita. È ora possibile teorizzare un modello di ente che offra una nuova tipologia di servizi da erogare all’interno di moderni impianti, riqualificati grazie al supporto di imprese che vedono le associazioni sportive come presidi per la salute dei lavoratori, favorendo il benessere collettivo oltre che la propria immagine.
Resumo:
This thesis deals with the analysis and management of emergency healthcare processes through the use of advanced analytics and optimization approaches. Emergency processes are among the most complex within healthcare. This is due to their non-elective nature and their high variability. This thesis is divided into two topics. The first one concerns the core of emergency healthcare processes, the emergency department (ED). In the second chapter, we describe the ED that is the case study. This is a real case study with data derived from a large ED located in northern Italy. In the next two chapters, we introduce two tools for supporting ED activities. The first one is a new type of analytics model. Its aim is to overcome the traditional methods of analyzing the activities provided in the ED by means of an algorithm that analyses the ED pathway (organized as event log) as a whole. The second tool is a decision-support system, which integrates a deep neural network for the prediction of patient pathways, and an online simulator to evaluate the evolution of the ED over time. Its purpose is to provide a set of solutions to prevent and solve the problem of the ED overcrowding. The second part of the thesis focuses on the COVID-19 pandemic emergency. In the fifth chapter, we describe a tool that was used by the Bologna local health authority in the first part of the pandemic. Its purpose is to analyze the clinical pathway of a patient and from this automatically assign them a state. Physicians used the state for routing the patients to the correct clinical pathways. The last chapter is dedicated to the description of a MIP model, which was used for the organization of the COVID-19 vaccination campaign in the city of Bologna, Italy.
Resumo:
Aims: The present study focuses on the analysis of novelty emergence in classic Gloria Films with Rogers, Perls, and Ellis to understand how the same client formulated her own problem and if and how change occurred in those three sessions. Method: The Innovative Moments Coding System was applied to track innovative moments (IMs) and their themes. Results: The session with Rogers showed more diversity in disclosed problems and themes of IMs, as well as a higher proportion of reflection IMs. The session with Perls demonstrated a high proportion of protest IMs. The session with Ellis showed less innovation than other sessions. The changes found were based mostly on reflection and protest IMs in three sessions. Conclusion: Narrative innovations occurred in the three single sessions. The type of dominant innovation is consistent with the therapeutic model and the IMs model. The exploration of the IMs’ themes allowed a more precise identification of Gloria's new narrative positions and their development throughout those sessions.