First-principles study of lithium-doped carbon clathrates under pressure

We present a theoretical study on the behavior under pressure of the two hypothetical C$_{46}$ and Li$_8$C$_{46}$ type-I carbon clathrates in order to bring new informations concerning their synthesis. Using \textit{ab initio} calculations, we have explored the energetic and structural properties under pressure of these two carbon based cage-like materials. These low-density meta-stable phases show large negative pressure transitions compared to diamond which represent a serious obstacle for their synthesis. However, we evidence that a minimum energy barrier can be reached close to 40 GPa, suggesting that the synthesis of the Li-clathrate under extreme conditions of pressure and temperature may be possible. Electronic band structure with related density of states behavior under pressure as well as the dependence of the active Raman modes with pressure are also examined

Rhombohedral calcite precipitation from CO2-H2O-Ca(OH)2 slurry under supercritical and gas CO2 media

The formation of solid calcium carbonate (CaCO3) from aqueous solutions or slurries containing calcium and carbon dioxide (CO2) is a complex process of considerable importance in the ecological, geochemical and biological areas. Moreover, the demand for powdered CaCO3 has increased considerably recently in various fields of industry. The aim of this study was therefore to synthesize fine particles of calcite with controlled morphology by hydrothermal carbonation of calcium hydroxide at high CO2 pressure (initial PCO2=55 bar) and at moderate and high temperature (30 and 90 degrees C). The morphology of precipitated particles was identified by transmission electron microscopy (TEM/EDS) and scanning electron microscopy (SEM/EDS). In addition, an X-ray diffraction analysis was performed to investigate the carbonation efficiency and purity of the solid product. Carbonation of dispersed calcium hydroxide in the presence of supercritical (PT=90 bar, T=90 degrees C) or gaseous (PT=55 bar, T=30 degrees C) CO2 led to the precipitation of sub-micrometric isolated particles (<1$\mu$m) and micrometric agglomerates (<5$\mu$m) of calcite. For this study, the carbonation efficiency (Ca(OH)2-CaCO3 conversion) was not significantly affected by PT conditions after 24 h of reaction. In contrast, the initial rate of calcium carbonate precipitation increased from 4.3 mol/h in the "90bar-90 degrees C" system to 15.9 mol/h in the "55bar-30 degrees C" system. The use of high CO2 pressure may therefore be desirable for increasing the production rate of CaCO3, carbonation efficiency and purity, to approximately 48 kg/m3h, 95% and 96.3%, respectively in this study. The dissipated heat for this exothermic reaction was estimated by calorimetry to be -32 kJ/mol in the "90bar-90 degrees C" system and -42 kJ/mol in the "55bar-30 degrees C" system

What's in a Message?

8 pagesInternational audienceIn this paper we present the first step in a larger series of experiments for the induction of predicate/ argument structures. The structures that we are inducing are very similar to the conceptual structures that are used in Frame Semantics (such as FrameNet). Those structures are called messages and they were previously used in the context of a multi-document summarization system of evolving events. The series of experiments that we are proposing are essentially composed from two stages. In the first stage we are trying to extract a representative vocabulary of words. This vocabulary is later used in the second stage, during which we apply to it various clustering approaches in order to identify the clusters of predicates and arguments—or frames and semantic roles, to use the jargon of Frame Semantics. This paper presents in detail and evaluates the first stage

Construction automatique d'un large corpus libre annoté morpho-syntaxiquement en français

National audienceCet article étudie la possibilité de créer un nouveau corpus écrit en français annoté morpho-syntaxiquement à partir d'un corpus annoté existant. Nos objectifs sont de se libérer de la licence d'exploitation contraignante du corpus d'origine et d'obtenir une modernisation perpétuelle des textes. Nous montrons qu'un corpus pré-annoté automatiquement peut permettre d'entraîner un étiqueteur produisant des performances état-de-l'art, si ce corpus est suffisamment grand

What's in a Message?

In this paper we present the first step in a larger series of experiments for the induction of predicate/argument structures. The structures that we are inducing are very similar to the conceptual structures that are used in Frame Semantics (such as FrameNet). Those structures are called messages and they were previously used in the context of a multi-document summarization system of evolving events. The series of experiments that we are proposing are essentially composed from two stages. In the first stage we are trying to extract a representative vocabulary of words. This vocabulary is later used in the second stage, during which we apply to it various clustering approaches in order to identify the clusters of predicates and arguments--or frames and semantic roles, to use the jargon of Frame Semantics. This paper presents in detail and evaluates the first stage

Harnessing GPT-3.5-turbo for Rhetorical Role Prediction in Legal Cases

We propose a comprehensive study of one-stage elicitation techniques for querying a large pre-trained generative transformer (GPT-3.5-turbo) in the rhetorical role prediction task of legal cases. This task is known as requiring textual context to be addressed. Our study explores strategies such as zero-few shots, task specification with definitions and clarification of annotation ambiguities, textual context and reasoning with general prompts and specific questions. We show that the number of examples, the definition of labels, the presentation of the (labelled) textual context and specific questions about this context have a positive influence on the performance of the model. Given non-equivalent test set configurations, we observed that prompting with a few labelled examples from direct context can lead the model to a better performance than a supervised fined-tuned multi-class classifier based on the BERT encoder (weighted F1 score of = 72%). But there is still a gap to reach the performance of the best systems = 86%) in the LegalEval 2023 task which, on the other hand, require dedicated resources, architectures and training

Rôle d'une base de connaissance dans SemIoTics, un système autonome contrôlant un appartement connecté

National audienceL'Internet des Objets représente une réalité de plus en plus concrète au fur et à mesure que se déploient de larges réseaux d'objets connectés. Ceux-ci ouvrent de larges perspectives d'applications, mais rencontrent des difficultés en terme d'interopérabilité, de configuration ou de passage à l'échelle. Ces probléma-tiques peuvent être traitées par le recours aux principes du web de données liées, d'où l'émergence d'ontologies dédiées aux applications de l'IoT, comme IoT-O, une ontologie pour l'IoT.Par ailleurs, une description en-richie des systèmes permet d'envisager leur configuration autonome : on parle alors d'autonomic computing. Ce papier présente SemIoTics, un système autonome reposant sur des bases de connaissance pour la gestion d'un appartement connecté. Nous présentons tout d'abord une vision générique d'une architecture de réseaux d'objets connectés qui permet de guider une analyse des travaux à l'interface du web sémantique et de l'IoT. Nous décrivons ensuite les deux bases de connaissances spécialisant IoT-O sur lesquelles s'appuie SemIoTics, et leur relation avec le dispositif expérimental. Enfin, la structure de ce système autonome de domotique est présenté en détails, et mis en relation avec l'architecture identifiée dans l'état de l'art

Implementing inter-professional patient-family centered plan of care meetings on an inpatient hospital unit

Inpatient plan of care meetings support efforts to encourage collaborative practice and patient-family centered care and result in an effective strategy to enhance communication and patient satisfaction. Clinical team members participated in patient/family centered plan of care meetings at a community hospital in a selected inpatient unit with full time hospitalist physicians. Quantitative data were gathered pre/post implementation from the external Hospital Consumer Assessment of Health Care Providers (HCAHPS) survey. HCAHPS data were collected independently, specifically for questions related to communication between patients, family members/guardians and the medical team and also the effects of care transition. There was a slow but steady upward trend in selected domains that reflected the standpoint of patients/families specific to patient communication and patient experience in care transition(s) during hospitalization. A greater upward trend was noted in the domain of communication with doctors. Qualitative data analysis revealed positive attitudes towards the plan of care meetings, and team members expressed concern regarding redundancy of information. Sharing amongst providers throughout the day identified a need for clearer criteria in patient selection for these meetings to maximize efforts and resources. A major concern was lack of direct feedback from the patient and family, the end users of the meetings. From this study, inter-professional collaboration in patient family centered care can be viewed as a positive aspect of efficient and innovative care delivery. More evidence-based research is needed to guide how inpatient hospital clinical care planning can be standardized to optimize the way in which patient family centered care can be supported by a collaborative coordinated effort among clinical team members. Experience Framework This article is associated with the Quality & Clinical Excellence lens of The Beryl Institute Experience Framework. (http://bit.ly/ExperienceFramework) Access other PXJ articles related to this lens. Access other resources related to this lens