A Model for Thermal Growth of Ultrathin Silicon Dioxide in O2 Ambient: A Rate Equation Approach

A new thermal oxidation model based on a rate equation approach with concentration dependent diffusion coefficient is proposed for ultrathin SiO2 for thicknesses of the order of 100 Å. The oxidation reaction of silicon is assumed to be dependent on the concentrations of unreacted silicon and oxygen. The results of oxide thickness versus oxidation time for various growth conditions and activation energies for diffusion coefficients are in agreement with various experimental data for O2 ambient

Bott--Kitaev periodic table and index theory

We consider topological insulators and superconductors with discrete symmetries and clarify the relevant index theory behind the periodic table proposed by Kitaev. An effective Hamiltonian determines the analytical index, which can be computed by a topological index. We focus on the spatial dimensions one, two and three, and only consider the bulk theory. In two dimensions, the $\mathbb{Z}$-valued invariants are given by the first Chern number. Meanwhile, $\mathbb{Z}_2$-valued invariants can be computed by the odd topological index and its variations. The Bott-Kitaev periodic table is well-known in the physics literature, we organize the topological invariants in the framework of KR-theory.Comment: 37 page

A Stochastic Model for Crystal-amorphous Transition in Low Temperature Molecular Beam Epitaxial Si(111)

Molecular beam epitaxial Si (111) grown below a certain temperature result in amorphous structure due to the limited surface mobility of atoms in finding correct epitaxial sites. In spite of many experimental and theoretical studies, the mechanism of crystal‐amorphous transition and its dynamics related to the growth conditions are not well understood. In this article, we present a theoretical model based on the formation of stacking fault like defects as a precursor to the amorphous transition of the layer. The model is simulated based on a stochastic model approach and the results are compared to that of experiments for temperatures in the range of 500–900 K and growth rate in the range of 0.1–3.0 Å/s. The agreement between our results and experimental observations is excellent

Existing and Evolving Bioethical Dilemmas, Challenges, and Controversies in Vascularized Composite Allotransplantation: An International Perspective From the Brocher Bioethics Working Group

Early results of hand and face transplants and other grafts such as those of uterus, penis, trachea, larynx, or abdominal wall have confirmed the potential for vascularized composite allotransplantation (VCA) to restore appearance, anatomy, function, independence, and social integration in patients suffering from devastating tissue deficits untreatable by conventional treatment options. Despite such promise, these novel and complex procedures face challenges and controversies that remain open to discussion and debate. Indeed, many barriers to clinical advancement and negative stakeholder perceptions still exist. The bioethical challenges surrounding VCA include but are not limited to justice and vulnerability of subjects, and their experiences with risks, benefits and outcomes, provider economy of fame, public awareness and attitudes toward transplantation, and policy and regulatory issues shaping progress of the field. The First International Workshop on Bioethical Challenges in Reconstructive Transplantation was organized by the Brocher Foundation in Hermance, Switzerland. VCA professionals representing teams from across the world examined bioethical issues in VCA related to standards for safety, efficacy, feasibility, privacy, confidentiality, and equitability. Key discussion topics from the workshop were included in a survey questionnaire implemented across VCA professionals attending the 13th Congress of International Society of VCA held in Salzburg, Austria. The insights from the Brocher workshop and International Society of VCA survey as presented here could help inform the future development of clinical practice and policy strategies in VCA to ensure value, accessibility, and acceptance of these procedures by potential donors, potential or actual recipients and their families, and providers and payers

VAST2015 Challenge Two: Event Analysis from Communication Data

Social Media is a very good example of a large communication network. Typically, most data generated by social media are embedded with spatiotemporal stamps which hold crucial information than can help law enforcement agencies analyze the intensity of a calamity or chaos. Currently, not much research is done in designing a visual analytics system that incorporates clustering methods to analyze communication patterns. This research seeks to develop an analysis tool that represents such diverse data sets in user-friendly visual forms, to provide insights into the data that will improve the efficiency of event analysis. To analyze this data we have employed a community detection algorithm that will help us group people together who exhibit similar behavior. To visualize these clusters and the relationships between each cluster we have used a force-directed graph which will help law enforcement officials interpret communication patterns and discover suspicious ones. Each cluster in the graph is colored distinctly and a list is also provided to display the people arranged in descending order of their communication frequencies with other people in the same cluster. This visualization allows users to find the most influential people in a group/cluster. The tool designed has been used to analyze the VAST 2015 Mini-Challenge 2 Data Set in order to detect some suspicious groups of individuals. Although this tool has been currently designed to analyze the VAST 2015 datasets, it can easily be modified to visualize other data sets such as twitter or any other similar social media source

Sensorimotor neural plasticity following hand transplantation measured with magnetoencephalography: A case study

This is a single case study that investigated brain connectivity (coherence) using Magnetoencephalography (MEG) in a twenty-four-year-old male who underwent hand transplantation of his right hand at 18 months after a traumatic injury. We examined the neuromagnetic fields of the whole brain during resting state. There is little research on brain reorganization and connectivity within the brain following transplantation, specifically, during resting state. Our findings revealed increased coherence within sensory cortices of the Default Mode Network (DMN) during the early phase of recovery while enhanced coherence in motor cortical regions became apparent in the later phase of recovery

A Few-Shot Approach to Dysarthric Speech Intelligibility Level Classification Using Transformers

Dysarthria is a speech disorder that hinders communication due to difficulties in articulating words. Detection of dysarthria is important for several reasons as it can be used to develop a treatment plan and help improve a person's quality of life and ability to communicate effectively. Much of the literature focused on improving ASR systems for dysarthric speech. The objective of the current work is to develop models that can accurately classify the presence of dysarthria and also give information about the intelligibility level using limited data by employing a few-shot approach using a transformer model. This work also aims to tackle the data leakage that is present in previous studies. Our whisper-large-v2 transformer model trained on a subset of the UASpeech dataset containing medium intelligibility level patients achieved an accuracy of 85%, precision of 0.92, recall of 0.8 F1-score of 0.85, and specificity of 0.91. Experimental results also demonstrate that the model trained using the 'words' dataset performed better compared to the model trained on the 'letters' and 'digits' dataset. Moreover, the multiclass model achieved an accuracy of 67%.Comment: Paper has been presented at ICCCNT 2023 and the final version will be published in IEEE Digital Library Xplor

Interface driven magnetoelectric effects in granular CrO2

Antiferromagnetic and magnetoelectric Cr2O3-surfaces strongly affect the electronic properties in half metallic CrO2. We show the presence of a Cr2O3 surface layer on CrO3 grains by high-resolution transmission electron microscopy. The effect of these surface layers is demonstrated by measurements of the temperature variation of the magnetoelectric susceptibility. A major observation is a sign change at about 100 K followed by a monotonic rise as a function of temperature. These electric field induced moments in CrO3 are correlated with the magnetoelectric susceptibility of pure Cr2O3. This study indicates that it is important to take into account the magnetoelectric character of thin surface layers of Cr2O3 in granular CrO2 for better understanding the transport mechanism in this system. The observation of a finite magnetoelectric susceptibility near room temperature may find utility in device applications.Comment: Figure 1 with strongly reduced resolutio

HEART RATE VARIABILITY PARAMETERS IN PATIENTS WITH ARTERIAL HYPERTENSION IN DEPENDENCE ON THE TYPE OF DAILY BLOOD PRESSURE PROFILE

Violation of functioning of the autonomic nervous system is an important factor in the formation and progression of arterial hypertension (AH). Abnormal nocturnal blood pressure (BP) reduction is regarded as an independent prognostic factor for cardiovascular complications in patients with AH. One of the possible factors that determine the violation of BP circadian rhythm can be imbalance of different parts of autonomic nervous system. The aim of our study was to study heart rate variability (HRV) in patients with AH, dependently of BP profile. 72 patients with AH were examined. Average age was 57 ± 11 years. All patients underwent ambulatory BP (ABPM) and ECG monitoring. To define the daily profile the nocturnal BP dip was quantified and for HRV evaluation the frequency analysis method was used. HRV changes in patients with AH present with reduced total power and with a violation in the ratio of the powers of very low, low and high frequencies, enhanced sympathycotension and influence of humoral factors. Violations of systolic BP (SBP) daily profile was mainly characterized by an increase in the power of low frequency waves, which indicates an intensification of sympathetic and decreased parasympathetic influences. Violations of diastolic BP (DBP) daily profile were mainly characterized by a relative increase in the power of very low frequency waves. The obtained results showed that in the management of patients with AH it is important not only to control the circadian SBP and DBP profiles, but the evaluation of HRV also