Microstructural design through 3D Direct Ink Writing of CaO from various origins to enhance the carbon capture process

La fabricació additiva ha progressat de forma notable en els últims anys. En especial, la impressió 3D ha permès la utilització de ceràmics en una gran varietat d'aplicacions gràcies a l'habilitat d'aquesta tècnica per poder fabricar capa a capa geometries complexes. Entre aquestes aplicacions, l'ús de ceràmiques en l’energia, com per exemple en la fabricació de catalitzadors ha tingut resultats alentidors. Al mateix temps, la família dels ceràmics és cada cop més el centre de les investigacions en la captura de carboni (CC). Aquest treball de final de grau (TFG) ha estudiat l'òxid de calci (CaO) i la seva optimització per ser processat de forma correcta per impressió 3D. Això s'ha fet per crear estructures de geometria complexa mitjançant la tècnica de Direct Ink Writing (DIW, en anglès). El CaO s'ha obtingut a partir de closca d'ous. Durant el TFG s'ha pogut optimitzar el mètode de neteja d'aquest residu fins a arribar a pureses per sobre del 98% de CaO. Per fomentar l'estabilitat química i mecànica dels productes s'han sinteritzat materials amb fases inerts d'alúmina (Al2O3) i zircònia (3Y-ZrO2). La 3Y-ZrO2 utilitzada en aquest TFG també ha servit per donar una segona vida a un residu, en aquest cas, industrial. A més, s'ha trobat que la temperatura de sinterització dels materials basats en el CaO era de 800 °C. A aquesta temperatura es van sinteritzar diverses pastilles i es va analitzar la seva estabilitat química a temperatura ambient. Finalment, també es van realitzar diversos post-tractaments una vegada sinteritzada les mostres per evitar reaccions paràsites amb l'humitat ambiental. Com conclusió d'aquest TFG es va poder destacar que la sinterització de CaO amb una carburació posterior incompleta és el tractament que permet obtenir el material desitjat amb una major estabilitat tant química com mecànica, podent imprimir peces per la metodologia DIW i posteriorment sinteritzar-les.La fabricación aditiva ha evolucionado en los últimos años de forma más que notable. Entre esta, destaca la impresión 3D, que ha abierto un nuevo abanico de aplicaciones para la familia de los cerámicos debido a la posibilidad de fabricar geometrías complejas. Un claro ejemplo ha sido el uso de cerámicos en catalizadores con resultados muy favorables. Al mismo tiempo, los cerámicos centran cada vez más las investigaciones en torno a la captura de carbono (CC). Este trabajo de final de grado (TFG) ha estudiado la optimización del óxido de calcio (CaO) para ser procesado de forma correcta por impresión 3D. El objetivo de dicho estudio es poder crear estructuras de geometría compleja mediante la técnica de Direct Ink Writing (DIW, en inglés). El CaO se ha obtenido a partir de cáscara de huevo, la cual se ha podido optimizar su limpieza, llegando a purezas por encima del 98% de CaO. Para fomentar la estabilidad química y mecánica de este compuesto, se ha estudiado la adición de fases inertes de alúmina (Al2O3) y zirconia (3Y-ZrO2). La 3Y-ZrO2 utilizada provenía también de un residuo, en este caso industrial. Además, se ha encontrado que la temperatura de sinterización de los materiales basados en CaO es de 800 °C. A esta temperatura se sinterizaron varias pastillas y se analizó su estabilidad química a temperatura ambiente. También, para lograr mayor estabilidad química, se realizaron varios tratamientos tras el sinterizado, para evitar reacciones secundarias con la humedad ambiental. Como conclusión de este TFG se puede destacar que la sinterización de CaO seguida de una carburación incompleta es el tratamiento que permite obtener el material deseado con una mayor estabilidad tanto química como mecánica, y permitiendo imprimir y sinterizar piezas por la metodolgía DIW para la CC.Additive manufacturing has progressed notably in recent years. Notably, 3D printing of ceramics has unlocked a wide variety of applications due to the ability of this methodology to form complex geometries. Among these, the use of ceramics in catalysis has had promising results in research. At the same time, ceramics such as Calcium Oxide (CaO) have been every time more in the centre of research related to the carbon capture (CC) process. This degree thesis has studied the optimal CaO-based feedstock and processing for the correct 3D printing of scaffoldings by means of the Direct Ink Writing (DIW) technique for the CC process. Parting from eggshell waste, distinct feedstocks were synthesized to achieve the maximum carbonation-calcination efficiencies while maintaining adequate chemical and mechanical stability. To reduce impurities which could negatively affect carbon capture results, an optimal cleaning method for eggshell waste was found that achieved over 98% CaO purity. To increase stability, feedstocks with inert zirconia (3Y-ZrO2) and Alumina (Al2O3) phases were made. While commercial α-Al2O3 was bought, 3Y-ZrO2 from industrial waste was used. Next, the sintering temperature of CaO-based feedstocks was determined to be 800 °C. At this temperature, several pellets of each material were synthesized were sintered and their chemical stability analysed. Finally, to maintain mechanical stability, various post-sintering treatments were carried out to try to avoid secondary reactions with atmospheric humidity at room temperature. Ultimately, CaO synthesis with a posterior incomplete carbonation had the highest chemical and mechanical stability, from which a 3D printed scaffolding was successfully manufactured

Past Precedent Reconciling Established Multimedia Principles in 3D Virtual Learning Environments

This design case documents the inception, development, and installation of a virtual exhibit on ethical use of learning analytics (LA) for the Museum of Instructional Design (MID), hosted in Mozilla Hubs. Tension emerged as the design team attempted to negotiate established principles of multimedia design theory (see Mayer, 2014; Mayer & Fiorella, 2021; Richardson, 2014) within an emerging learning environment. A rapid prototyping model, combined with elements of critical museology and dialectics, allowed for ongoing formative evaluation of design fidelity. Exhibit artifacts consisted of scenarios illustrating the ethical ambiguities of LA; a data justice timeline pairing recent peer-reviewed articles on LA with significant contemporaneous milestones in data privacy; audio zones highlighting the dialectical dialogue between those who support LA use and those who advise caution; and a response wall for museum visitors to extend the discussion. Beyond application of multimedia design principles to artifacts, 3D spaces also demand consideration of space and movement flow. Lacking precedent, this exhibit design was guided by the Smithsonian’s (2018) recommendations for in-person exhibits. It is the intention of the design team that this design case highlights the need for a reconsideration of established multimedia theory when designing for emerging learning environments

Identifying the domains of context important to implementation science: a study protocol

Background There is growing recognition that “context” can and does modify the effects of implementation interventions aimed at increasing healthcare professionals’ use of research evidence in clinical practice. However, conceptual clarity about what exactly comprises “context” is lacking. The purpose of this research program is to develop, refine, and validate a framework that identifies the key domains of context (and their features) that can facilitate or hinder (1) healthcare professionals’ use of evidence in clinical practice and (2) the effectiveness of implementation interventions. Methods/design A multi-phased investigation of context using mixed methods will be conducted. The first phase is a concept analysis of context using the Walker and Avant method to distinguish between the defining and irrelevant attributes of context. This phase will result in a preliminary framework for context that identifies its important domains and their features according to the published literature. The second phase is a secondary analysis of qualitative data from 13 studies of interviews with 312 healthcare professionals on the perceived barriers and enablers to their application of research evidence in clinical practice. These data will be analyzed inductively using constant comparative analysis. For the third phase, we will conduct semi-structured interviews with key health system stakeholders and change agents to elicit their knowledge and beliefs about the contextual features that influence the effectiveness of implementation interventions and healthcare professionals’ use of evidence in clinical practice. Results from all three phases will be synthesized using a triangulation protocol to refine the context framework drawn from the concept analysis. The framework will then be assessed for content validity using an iterative Delphi approach with international experts (researchers and health system stakeholders/change agents). Discussion This research program will result in a framework that identifies the domains of context and their features that can facilitate or hinder: (1) healthcare professionals’ use of evidence in clinical practice and (2) the effectiveness of implementation interventions. The framework will increase the conceptual clarity of the term “context” for advancing implementation science, improving healthcare professionals’ use of evidence in clinical practice, and providing greater understanding of what interventions are likely to be effective in which contexts

A guide to using the Theoretical Domains Framework of behaviour change to investigate implementation problems

Background: Implementing new practices requires changes in the behaviour of relevant actors, and this is facilitated by understanding of the determinants of current and desired behaviours. The Theoretical Domains Framework (TDF) was developed by a collaboration of behavioural scientists and implementation researchers who identified theories relevant to implementation and grouped constructs from these theories into domains. The collaboration aimed to provide a comprehensive, theory-informed approach to identify determinants of behaviour. The first version was published in 2005, and a subsequent version following a validation exercise was published in 2012. This guide offers practical guidance for those who wish to apply the TDF to assess implementation problems and support intervention design. It presents a brief rationale for using a theoretical approach to investigate and address implementation problems, summarises the TDF and its development, and describes how to apply the TDF to achieve implementation objectives. Examples from the implementation research literature are presented to illustrate relevant methods and practical considerations. Methods: Researchers from Canada, the UK and Australia attended a 3-day meeting in December 2012 to build an international collaboration among researchers and decision-makers interested in the advancing use of the TDF. The participants were experienced in using the TDF to assess implementation problems, design interventions, and/or understand change processes. This guide is an output of the meeting and also draws on the a uthors' collective experience. Examples from the implementation research literature judged by authors to be representative of specific applications of the TDF are included in this guide. Results: We explain and illustrate methods, with a focus on qualitative approaches, for selecting and specifying target behaviours key to implementation, selecting the study design, deciding the sampling strategy, developing study materials, collecting and analysing data, and reporting findings of TDF-based studies. Areas for development include methods for triangulating data, e.g. from interviews, questionnaires and observation and methods for designing interventions based on TDF-based problem analysis. Conclusions: We offer this guide to the implementation community to assist in the application of the TDF to achieve implementation objectives. Benefits of using the TDF include the provision of a theoretical basis for implementation studies, good coverage of potential reasons for slow diffusion of evidence into practice and a method for progressing from theory-based investigation to intervention

Determinants of penetrance and variable expressivity in monogenic metabolic conditions across 77,184 exomes

Penetrance of variants in monogenic disease and clinical utility of common polygenic variation has not been well explored on a large-scale. Here, the authors use exome sequencing data from 77,184 individuals to generate penetrance estimates and assess the utility of polygenic variation in risk prediction of monogenic variants

In-situ estimation of ice crystal properties at the South Pole using LED calibration data from the IceCube Neutrino Observatory

The IceCube Neutrino Observatory instruments about 1 km3 of deep, glacial ice at the geographic South Pole using 5160 photomultipliers to detect Cherenkov light emitted by charged relativistic particles. A unexpected light propagation effect observed by the experiment is an anisotropic attenuation, which is aligned with the local flow direction of the ice. Birefringent light propagation has been examined as a possible explanation for this effect. The predictions of a first-principles birefringence model developed for this purpose, in particular curved light trajectories resulting from asymmetric diffusion, provide a qualitatively good match to the main features of the data. This in turn allows us to deduce ice crystal properties. Since the wavelength of the detected light is short compared to the crystal size, these crystal properties do not only include the crystal orientation fabric, but also the average crystal size and shape, as a function of depth. By adding small empirical corrections to this first-principles model, a quantitatively accurate description of the optical properties of the IceCube glacial ice is obtained. In this paper, we present the experimental signature of ice optical anisotropy observed in IceCube LED calibration data, the theory and parametrization of the birefringence effect, the fitting procedures of these parameterizations to experimental data as well as the inferred crystal properties.</p

Galactic Core-Collapse Supernovae at IceCube: “Fire Drill” Data Challenges and follow-up

The next Galactic core-collapse supernova (CCSN) presents a once-in-a-lifetime opportunity to make astrophysical measurements using neutrinos, gravitational waves, and electromagnetic radiation. CCSNe local to the Milky Way are extremely rare, so it is paramount that detectors are prepared to observe the signal when it arrives. The IceCube Neutrino Observatory, a gigaton water Cherenkov detector below the South Pole, is sensitive to the burst of neutrinos released by a Galactic CCSN at a level >10σ. This burst of neutrinos precedes optical emission by hours to days, enabling neutrinos to serve as an early warning for follow-up observation. IceCube\u27s detection capabilities make it a cornerstone of the global network of neutrino detectors monitoring for Galactic CCSNe, the SuperNova Early Warning System (SNEWS 2.0). In this contribution, we describe IceCube\u27s sensitivity to Galactic CCSNe and strategies for operational readiness, including "fire drill" data challenges. We also discuss coordination with SNEWS 2.0

All-Energy Search for Solar Atmospheric Neutrinos with IceCube

The interaction of cosmic rays with the solar atmosphere generates a secondary flux of mesons that decay into photons and neutrinos – the so-called solar atmospheric flux. Although the gamma-ray component of this flux has been observed in Fermi-LAT and HAWC Observatory data, the neutrino component remains undetected. The energy distribution of those neutrinos follows a soft spectrum that extends from the GeV to the multi-TeV range, making large Cherenkov neutrino telescopes a suitable for probing this flux. In this contribution, we will discuss current progress of a search for the solar neutrino flux by the IceCube Neutrino Observatory using all available data since 2011. Compared to the previous analysis which considered only high-energy muon neutrino tracks, we will additionally consider events produced by all flavors of neutrinos down to GeV-scale energies. These new events should improve our analysis sensitivity since the flux falls quickly with energy. Determining the magnitude of the neutrino flux is essential, since it is an irreducible background to indirect solar dark matter searches

TXS 0506+056 with Updated IceCube Data

Past results from the IceCube Collaboration have suggested that the blazar TXS 0506+056 is a potential source of astrophysical neutrinos. However, in the years since there have been numerous updates to event processing and reconstruction, as well as improvements to the statistical methods used to search for astrophysical neutrino sources. These improvements in combination with additional years of data have resulted in the identification of NGC 1068 as a second neutrino source candidate. This talk will re-examine time-dependent neutrino emission from TXS 0506+056 using the most recent northern-sky data sample that was used in the analysis of NGC 1068. The results of using this updated data sample to obtain a significance and flux fit for the 2014 TXS 0506+056 "untriggered" neutrino flare are reported