Improved graphene blisters by ultrahigh pressure sealing

Graphene is a very attractive material for nanomechanical devices and membrane applications. Graphene blisters based on silicon oxide micro-cavities are a simple but relevant example of nanoactuators. A drawback of this experimental set up is that gas leakage through the graphene-SiO2 interface contributes significantly to the total leak rate. Here we study the diffusion of air from pressurized graphene drumheads on SiO2 micro-cavities and propose a straightforward method to improve the already strong adhesion between graphene and the underlying SiO2 substrate, resulting in reduced leak rates. This is carried out by applying controlled and localized ultrahigh pressure (> 10 GPa) with an Atomic Force Microscopy diamond tip. With this procedure, we are able to significantly approach the graphene layer to the SiO2 surface around the drumheads, thus enhancing the interaction between them allowing us to better seal the graphene-SiO2 interface, which is reflected in up to ~ 4 times lower leakage rates. Our work opens an easy way to improve the performance of graphene as a gas membrane on a technological relevant substrate such as SiO2.Comment: pages 19, 4 figures + supplementary informatio

A LOCAL DIFFERENTIAL QUADRATURE METHOD WITH VARIABLE SHAPE MULTIQUADRICS: TESTS ON POISSON EQUATION AND FLUID DYNAMICS USING CONSISTENT CLOUD REFINEMENTS

A meshless Local Differential Quadrature Method for solving partial differential equations is presented in this paper. It is based in a point cloud discretization and local supports. A basis set of Multiquadric functions is employed for determining the weight coefficients in derivative approximations. Tests with the Poisson equation are presented for verifying the converge behavior of the method in Clouds with Unstructured Generation (CUG’s). A consistent refinement procedure for varying the multiquadric shape parameter between local supports is proposed. The method is finally applied for solving the classical benchmark problem of natural convection in a square cavity. Satisfactory results were obtained in comparison with the reference literature

A Visual Zooarchaeology Guide for Florida Artifacts

One key factor of archeology research is discovering the faunal bones at excavation sites and seeing what lived many years ago. Faunal remains are bones, hair, shells, and more, any piece of animal anatomy. Discovering the different types of bones at excavations in Florida can give archeologists a sense of the different species in this state that were utilized by humans in the past. This study is creating a visual guide and key for faunal bone artifacts in south Florida. The key will consist of photos of bone artifacts excavated in south Florida of different types of fish and other animals. Also, the key will describe the bones excavated so that people and scientists can know what the defining characteristics of different bones are. Creating this key will be helpful for any other researcher to teach how to identify archaeological bone

Privacy-preserving machine learning for healthcare: open challenges and future perspectives

Machine Learning (ML) has recently shown tremendous success in modeling various healthcare prediction tasks, ranging from disease diagnosis and prognosis to patient treatment. Due to the sensitive nature of medical data, privacy must be considered along the entire ML pipeline, from model training to inference. In this paper, we conduct a review of recent literature concerning Privacy-Preserving Machine Learning (PPML) for healthcare. We primarily focus on privacy-preserving training and inference-as-a-service, and perform a comprehensive review of existing trends, identify challenges, and discuss opportunities for future research directions. The aim of this review is to guide the development of private and efficient ML models in healthcare, with the prospects of translating research efforts into real-world settings.Comment: ICLR 2023 Workshop on Trustworthy Machine Learning for Healthcare (TML4H

LA BIOGRAFÍA ARQUITECTÓNICA: UNA ALTERNATIVA PARA CARACTERIZAR LOS ASENTAMIENTOS ILERGETES DURANTE LA ÉPOCA DE CONQUISTA

Resumen: La conquista de  la Península Ibérica, originó en el nordeste peninsular la hibridación cultural entre dos etnias bien diferenciadas, conocidas como los pueblos ibéricos y los romanos, cuya plasmación más impresionante se dio en los cambios arquitectónicos de los asentamientos indígenas a partir de época republicana.El objetivo de este trabajo ha sido analizar dichas alteraciones en las planimetrías originales, tomando como muestra cinco poblados ilergetes de las zonas de interior, repartidos entre tres comarcas actuales diferenciadas geográficamente.Sometiendo a examen   dichas estructuras se ha pretendido no sólo analizar los cambios funcionales y estructurales, sino también establecer una categorización mediante un eje cronológico y geográfico, ofreciendo una imagen lo más completa posible de las variaciones en los patrones de poblamiento desde  el siglo III a.C. hasta el cambio de Era, amén de los cambios coyunturales que acompañaron a este proceso