263134 research outputs found
Sort by
Closing the mind-body divide: physiotherapists as leaders in pain management in serious mental illness
No full textsponsorship: BS is supported by an NIHR Advanced Fellowship (NIHR301206) . (NIHR Advanced Fellowship|NIHR301206)status: Accepte
Anomaly Detection under Contaminated Data: A Weighted Iterative Refinement Framework for Health Monitoring
No full textReliable anomaly detection under data contamination remains a major challenge in Prognostics and Health Management, especially when degradation processes are gradual and clean training data are unavailable. This paper introduces a weighted iterative refinement framework with autoencoders for contaminated anomaly detection (WIRACAD) to address this problem. The method, which is based on reconstruction residuals, re-weights training samples across iterations in order to progressively reduce the influence of suspected anomalies. This continuous refinement improves the robustness of health indicator learning from contaminated time series. The proposed approach is evaluated on two public benchmarks: the NASA C-MAPSS dataset and the IMS Bearing dataset. Results show consistent improvements in key metrics related to degradation monitoring. In particular, the overal fit score and the monotonicty are improved when compared to baseline autoencoder training and recent refinement-based methods. These findings suggest that iterative sample weighting can enhance unsupervised anomaly detection with autoencoders in settings where data contamination is assumed.status: Published onlin
Studie van het Directe Magneto-elektrische Effect voor Geavanceerde Geheugentoepassingen
No full textMagnetic memories are presently intensely researched for embedded memory applications. Especially magnetic random-access memory (MRAM) has recently been started to be commercialized in consumer appliances and it can be expected that it will become broadly used in the near future. In such magnetic memories, the information is stored in the orientation of the perpendicular magnetization in a magnetic tunnel junction. The resistance of the tunnel junction is used to read the information whereas spin-transfer torque is used to write the information. To improve the performance of the cell and to open new application fields, both the read and write speed of the MRAM cells need to be improved without affecting the memory retention. To date, much research is being devoted to improving the write performance of MRAM cells using e.g. spin-orbit torques or voltage-controlled magnetic anisotropies. By contrast, rather little attention has been paid to the read performance of MRAM cells. To improve the read performance, the current resistance-based scheme using magnetic tunnel junctions needs to be replaced by a scheme that generates a direct electrical signal. In particular voltage-based schemes using magnetoelectric materials and compounds appear promising. In recent years, magnetoelectricity has seen a renaissance due to technological and theoretical progress. While the field is currently transitioning from basic science to applied device research, many open issues remain. Several different magnetoelectric material approaches exist. Multiferroics are materials that possess simultaneously ferroelectric and ferromagnetic properties and can therefore link magnetic information and voltage signals. Among multiferroics, magnetocapacitive materials show some promise to obtain voltage signals from the state of a nanomagnet. By contrast, the most efficient magnetoelectric systems are layered compounds consisting of piezoelectric and magnetostrictive materials, which couple magnetic and electric domains via strain. To date, studies of magnetoelectric compounds and magnetocapacitive materials have mainly focused on bulk and large-scale systems with very few reports on micrometer size devices. This thesis will thus focus on the study of such magnetoelectric systems in view of their utilization for MRAM read-out schemes. This will include the patterning and the characterization of relevant materials on the nanoscale as well as the design, fabrication, and characterization of suitable test device structures.status: Publishe
De rol van argon ets plasma samenstelling op ultradunne extreme ultraviolet resists
No full textState-of-the-art microchips can contain over a billion transistors with up to a hundred intricate layers forming complex circuits. The goal of advancing semiconductor fabrication is to produce increasingly smaller transistors, as this can improve the performance and reduce the power consumption of these chips. This fabrication process of these chips is highly complex, involving many steps starting from a silicon substrate. In this project, we focus on two steps in this fabrication process flow: photolithography (or lithography) and plasma etching. These are involved in making the intricate patterns in a chip. In lithography, a pattern from a template, known as a mask, is transferred using light to a photosensitive layer called photoresist (or resist), which is coated on top of the layer to be patterned. One of the main enablers for the miniaturization of transistors has been the improved resolution of patterning during lithography. By reducing the wavelength of light used during lithography, the diffraction-limited resolution can be improved, allowing the patterning of small features. Currently, the state-of-the-art lithography tools use light with a wavelength of 13.5 nm , referred to as extreme ultraviolet (EUV) light. With EUV lithography, sub-10 nm features can be printed in the resist. The next step after patterning the resist is to transfer it from the resist to the layer below. This is done via plasma etching. As the name states, plasma is used to remove (or etch) the regions of the layer that are not protected by the patterned resist creating the pattern transfer. During etching, it is important for the patterned resist to remain intact under plasma exposure for a successful pattern transfer. Typical plasmas used for etching contain ions, vacuum ultraviolet (VUV) photons, radicals, and electrons. One of the challenges with EUV lithography is that the resists used are ultrathin (<50 nm) and can undergo significant modification by these plasma species during etching. This can, in turn, complicate the pattern transfer process. In this context, it is valuable to study the interactions of plasma species with ultrathin resists, as this can help in resist design and etch process development.
The main goal of this project is to study the impact of argon plasma on ultrathin resists. Argon gas is commonly used in various etch chemistries for plasma etching. Here, we focus on the impact VUV photons and Ar+ ions, which are the main etching species present in an argon plasma, on ultrathin resists. To do this, we process the resist films under three different conditions: exposure to only VUV photons using a deuterium lamp, exposure to only Ar+ ions using an ion beam etch tool, and exposure to Ar plasma using an inductively coupled plasma etch tool. We then use different characterization techniques such as atomic force microscopy, ellipsometry, and infrared spectroscopy to study the physical and chemical changes occurring in these films after different exposures.
In the first part of this project, we studied the impact of argon plasma species on a 40 nm thick polymethylmethacrylate (PMMA) film. PMMA is a simple homopolymer and has been widely studied as a model photoresist. This made it an ideal first candidate to validate our testing methodology. We observed that VUV photons and Ar+ ions interact quite differently with PMMA. VUV photons penetrate the entire film, causing significant side chain degradation throughout the bulk. Ar+ ions mainly interact at the top of the film, creating a carbon-rich ion-modified layer while leaving the bulk pristine-like. For the plasma-exposed PMMA, both bulk modification from VUV photons and the formation of a top ion-modified layer are observed. These interactions result in additional synergistic effects, leading to substantial surface modification.
Next, we extended this methodology to a popular type of organic EUV resist called chemically amplified resists (CARs). Here, we investigated three different formulations of negative tone EUV CARs, differing in their polymer structure, along with PMMA as a reference resist. The etch rate of the resists was dependent on both their chemistry and starting thickness. Resists with aromatic groups and a high carbon to oxygen ratio showed higher etch resistance. Thinner PMMA shower lower etch rate compared to its thicker counterpart. This behavior was attributed to the attractive interaction between PMMA and the underlayer, which affects the film properties and further influences the etch rate. Similar to PMMA in the previous study, the CARs also showed the presence of an ion-modified carbonized layer at the top. The surface roughness evolution of the resists when exposed to full Ar plasma was complex. Multiple factors such as plasma heating, substrate effect, resist chemistry, and the initial thickness of the resist, are expected to influence this process. We also tested the validity of the Ohnishi number and ring parameter etch rate models for the resists and processing conditions used. Both models could predict the etch rate trends of the EUV CARs reasonably well.
In the final part of this project, we investigated the impact of Ar plasma species on a zinc-containing organometallic EUV resist called ZONE. Metal-containing hybrid resists are promising for EUV lithography due to their high EUV absorption cross-section, small molecular size, and good etch resistance. ZONE is composed of zinc-oximate molecules, and similar to the previous studies, we exposed it to VUV photons, Ar+ ions, and Ar plasma. VUV photons mainly affected the oxime ligand, causing degradation of the organic moieties in the resist and an increase in the refractive index. Ar+ ions, similar to previous results on PMMA and CARs, still appeared to modify only the top of the film. However, unlike in PMMA and CARs, no indication of carbonization was observed. The lack of carbonization was attributed to the absence of carbon-rich polymeric structures in ZONE. The thermal stability of ZONE was also tested by baking it on a hot plate to above 100 C. The thickness of ZONE decreased with baking, indicating that heating is also an important pathway for degradation. The plasma-exposed ZONE showed a significant loss of the ligand IR peaks, a substantial increase in the refractive index, and a distinct grainy surface. These findings strongly pointed to the formation of zinc oxide grains at the surface of the plasma-exposed ZONE. This formation of these grains was attributed to significant modification of the film surface due to the combined effects of Ar+ ions, VUV photons, and plasma heating.
In conclusion, over the course of multiple studies in this project, we have investigated the impact of VUV photons and Ar+ ions on ultrathin EUV resists during argon plasma etching. Our findings highlight the role of VUV photons in modifying the bulk properties of the resists, while Ar+ ions predominantly affect the surface. The complex interaction of these two modifications, along with additional factors like plasma heating, give rise to unique combined effects in Ar plasma, especially at the surface of the resist films. In addition to this, the importance of the starting thickness of these ultrathin films and the interfacial interactions with the underlayer have also been highlighted. The results from this study serve as an initial point for further exploration of plasma-resist interactions in EUV resists.status: Publishe
New 1,2,3-triazole-α-aminophosphonate acyclic nucleosides scaffold: Design, synthesis, docking studies and biological evaluation as potential <i>S. aureus</i> agents
No full textstatus: Accepte
De weg naar biorelevantere in vitro-systemen: een verbeterde voorspelling van het gedrag van orale geneesmiddelen in de gevoede toestand
No full textTo reliably predict human dose and pharmacokinetics of oral drugs as well as to assess the feasibility of product development for novel drug candidates, accurate measurements of intestinal drug solubility and permeability are urgently needed in preclinical development. This project aims to improve preclinical assays used for predicting the performance of oral drug compounds and products. For this purpose, the project will focus on the design, validation and implementation of optimized tools for solubility and permeability measurements in biorelevant conditions. This shall be achieved through the following work packages: (1) Improved understanding of the differences in drug solubility in simulated, animal and human intestinal fluids, (2) Design of species-relevant media for solubility and permeability determinations, (3) Development of preclinical tools to measure permeability of BCS IV compounds, and (4) Combined dissolution/permeability experiments to study formulation performance.status: Publishe
Godslastering en belediging van religieuze gevoelens heroverwogen: een pleidooi voor retorische beleefdheid
No full textThis dissertation examines the contested uses of Christian symbolism for non-religious purposes as capable of both evoking deeper meanings and provoking outrage. This dynamic emerges from the interplay between the symbol's inherent ambiguity, its resistance to complete appropriation, and the specific features of the surrounding public discourse. By investigating the reasons behind labelling unorthodox symbol-uses as blasphemy, the dissertation presents offence-giving, offence-taking, and even mere offence-witnessing as communicative acts that can be analyzed through the original lens of rhetorical civility. The research journey unfolds across five chapters: three offer hermeneutics of the key concepts - offence, civility, and blasphemy - while two synthesize these insights.
The first chapter explores the notion of offence too feelings, critiquing both overly demanding and restrictive notions of respect as its cure, found in policy frameworks. This sets the stage for a humble, yet promising approach advanced in the second chapter: rhetorical civility. By examining the intersections of civility, the care for the outward (or "the way it looks"), and religious character formation, the chapter articulates some principles of sensitive evocations of symbols mindful of their personal and communal significance.
The next chapter offers a wide-ranging portrayal of archetypical blasphemers and argues for a specifically theological engagement with blasphemy that resists secular (civil, aesthetic, political etc.) reductions. The idea of theological undesirability is introduced here to address both expressive and doctrinal concerns in labelling something as blasphemous. Blasphemy's potential to distort the references to divine and covenantal relationships between God and humanity is discussed here.
The penultimate chapter consolidates these explorations, emphasizing the affective, evaluative, and symbolic dimensions of offence as rhetorically compelling and capable of inspiring care-driven engagement. It frames offence-taking as an act of care, a symbolic expression of loyalty. Similarly, offence-giving can also arise from care: a commitment to ensuring a symbol's continued meaningfulness in changing contexts. Whereas the witnesses of offence are encouraged to care for truly inclusive spaces open to robust perspectives.
The final chapter offers an original deepening of the discussion on blasphemy. It distinguishes between the tropological, rhetorical, and theological dimensions of expressions that may appear blasphemous, urging caution in labeling them as such. Here, paramount blasphemy is framed as a counterpart to worship. The roles of offenders and the offended are refined as respectively symbols' appropriators and stewards, acknowledging passive and active aspects of these engagements. The simplistic hierarchies between insider and outsider perspectives are resisted here, while parallels in their interpretative efforts discourage both suppressive conformity and reckless provocation. A distinctive contribution here is delving into the relationship between sin and blasphemy, as well as the idea of God's impassibility that must not always preclude harm.
This work invites offence-givers, -takers, and -witnesses alike to engage in self- and other-exploration informed by care, symbolic literacy, and imaginative dialogue. Such engagement fosters a more hospitable public sphere, supports moral growth, and strengthens communal resilience. The vision presented here challenges both the uncritical vilification and the careless celebration of blasphemy, seeking instead to cultivate a public discourse that is sensitive, inclusive, and resistant to monocultural tendencies.status: Publishe
Unlocking Durable and Sustainable Zinc-Iodine Batteries via Molecularly Engineered Polyiodide Reservoirs
No full textZinc-iodine batteries (ZIBs) are promising candidates for safe and sustainable energy storage but are hindered by polyiodide shuttling, leading to rapid capacity decay and limited cyclability. In this work, we propose a "polyiodide reservoirs" concept, utilizing iodophilic covalent organic cages to confine polyiodide through multiple noncovalent interactions. By precisely engineering the nitrogen-active site densities around 3D cavities, these cages evolve from open to near-enclosed structure, achieving molecular-level polyiodide entrapment. The optimized superphane cage (18 N-active sites) enables a ZIB with 90.1% capacity retention after 4000 cycles at 5 C, even under extreme conditions (58.9 wt% iodine content within the cage and an iodine area loading of 3.7 mg cm-2 in the cathode). Importantly, the cage's solubility-driven regeneration capability retains 85.4% initial capacity over three reuse cycles. This work establishes covalent organic superphanes as a transformative platform for long-life ZIBs, offering a dual solution to shuttle suppression and electrode sustainability through structural confinement and dynamic recyclability.sponsorship: The authors sincerely acknowledge financial support from the National Natural Science Foundation of China (22371068 (Q.H.)), the Research Foundation-Flanders (1298323N), and the Shanghai Scientific and Technological Innovation Project (22520710100). J.H. acknowledges financial support from the Research Foundation-Flanders (FWO, Grant No. G983.19N and ZW15_09-G0H6316N), the Flemish government through long-term structural funding Methusalem (CASAS2, Meth/15/04) and the Moonshot cSBO project P2C (HBC.2019.0108), the Interne Fondsen KU Leuven through project C3/20/067, and the MPI as MPI fellow. The authors also acknowledge the technical support of standard spectroscopic analysis (e.g., nuclear magnetic resonance and high-resolution mass spectrometry) at Analytical Instrumentation Center of Hunan University, and the Supercomputing Center of Zhengzhou University for the support in DFT calculations. (National Natural Science Foundation of China, Shanghai Scientific and Technological Innovation Project|22520710100, Research Foundation-Flanders (FWO)|G983.19N, Research Foundation-Flanders (FWO)|ZW15_09-G0H6316N, Flemish government|CASAS2, Moonshot cSBO project P2C|HBC.2019.0108, Interne Fondsen KU Leuven|C3/20/067, 22371068, 1298323N)status: Publishe
