1,013 research outputs found

    Contamination due to memory effects in filtered vacuum arc plasma deposition systems

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    Thin film synthesis by filtered vacuum arc plasma deposition is a widely used technique with a number of important emerging technological applications. A characteristic feature of the method is that during the deposition process not only is the substrate coated by the plasma, but the plasma gun itself and the magnetic field coil and/or vacuum vessel section constituting the macroparticle filter are also coated to some extent. If then the plasma gun cathode is changed to a new element, there can be a contamination of the subsequent film deposition by sputtering from various parts of the system of the previous coating species. We have experimentally explored this effect and compared our results with theoretical estimates of sputtering from the SRIM (Stopping and Range of Ions in Matter) code. We find film contamination of order 10-4 - 10-3, and the memory of the prior history of the deposition hardware can be relatively long-lasting

    ANALYSIS OF THE ETCHING MECHANISMS OF TUNGSTEN IN FLUORINE-CONTAINING PLASMAS

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    Tungsten and polysilicon layers were etched in three different types of etching equipment, in different etching modes. Etch rates and wall profiles were determined. Partially etched tungsten layers were analyzed through Auger spectroscopy. Combining all these results, it was possible to determine the etch rate limiting subprocesses for tungsten etching. For most process conditions, the arrival of atomic fluorine at the wafer surface is the etch rate limiting mechanism. For other processes, the removal of products with low volatility is the limiting mechanism.14261971197

    Quasiparticle properties in a density functional framework

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    We propose a framework to construct the ground-state energy and density matrix of an N-electron system by solving selfconsistently a set of single-particle equations. The method can be viewed as a non-trivial extension of the Kohn-Sham scheme (which is embedded as a special case). It is based on separating the Green's function into a quasi-particle part and a background part, and expressing only the background part as a functional of the density matrix. The calculated single-particle energies and wave functions have a clear physical interpretation as quasiparticle energies and orbitals.Comment: 12 pages, 1 figure, to be published in Phys. Rev.

    m-Path:An easy-to-use and highly tailorable platform for ecological momentary assessment and intervention in behavioral research and clinical practice

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    In this paper, we present m-Path (www.m-Path.io), an online platform that provides an easy-to-use and highly tailorable framework for implementing smartphone-based ecological momentary assessment (EMA) and intervention (EMI) in both research and clinical practice in the context of blended care. Because real-time monitoring and intervention in people's everyday lives have unparalleled benefits compared to traditional data collection techniques (e.g., retrospective surveys or lab-based experiments), EMA and EMI have become popular in recent years. Although a surge in the use of these methods has led to a myriad of EMA and EMI applications, many existing platforms only focus on a single aspect of daily life data collection (e.g., assessment vs. intervention, active self-report vs. passive mobile sensing, research-dedicated vs. clinically-oriented tools). With m-Path, we aim to integrate all of these facets into a single platform, as it is exactly this all-in-one approach that fosters the clinical utility of accumulated scientific knowledge. To this end, we offer a comprehensive platform to set up complex and highly adjustable EMA and EMI designs with advanced functionalities, using an intuitive point-and click web interface that is accessible for researchers and clinicians with limited programming skills. We discuss the strengths of daily life data collection and intervention in general and m-Path in particular. We describe the regular workflow to set up an EMA or EMI design within the m-Path framework, and summarize both the basic functionalities and more advanced features of our software

    The food contaminant fumonisin B1 reduces the maturation of porcine CD11R1+ intestinal antigen presenting cells and antigen-specific immune responses, leading to a prolonged intestinal ETEC infection

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    Consumption of food or feed contaminated with fumonisin B1 (FB1), a mycotoxin produced by Fusarium verticillioides, can lead to disease in humans and animals. The present study was conducted to examine the effect of FB1 intake on the intestinal immune system. Piglets were used as a target and as a model species for humans since their gastro-intestinal tract is very similar. The animals were orally exposed to a low dose of FB1 (1 mg/kg body weight FB1) for 10 days which did not result in clinical signs. However, when compared to non-exposed animals, FB1-exposed animals showed a longer shedding of F4+ enterotoxigenic Escherichia coli (ETEC) following infection and a lower induction of the antigen-specific immune response following oral immunization. Further analyses to elucidate the mechanisms behind these observations revealed a reduced intestinal expression of IL-12p40, an impaired function of intestinal antigen presenting cells (APC), with decreased upregulation of Major Histocompatibility Complex Class II molecule (MHC-II) and reduced T cell stimulatory capacity upon stimulation. Taken together, these results indicate an FB1-mediated reduction of in vivo APC maturation

    Comparative study between wet and dry etching of silicon for microchannels fabrication

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    FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOIn this work we present a comparative study of two processes for the fabrication of an array of microchannels for microfluidics applications, based on integrated-circuit technology process steps, such as lithography and dry etching. Two different methods were investigated in order to study the resulting microstructures: wet and dry deep etching of silicon substrate. The typical etching depth necessary to the target application is 50 mu m.1093015FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO2016/09509-112. Conference on Advanced Fabrication Technologies for Micro/Nano Optics and Photonics3 a 5 de Fevereiro de 2019San Francisco, CA, Estados UnidosSPIE; Nanoscribe Gmb
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