4,338 research outputs found

    Possibilities for Flexible MEMS: Take Display Systems as Examples

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    Recrystallized parylene as a mask for silicon chemical etching

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    This paper presents the first use of recrystallized parylene as masking material for silicon chemical etch. Recrystallized parylene was obtained by melting parylene C at 350°C for 2 hours. The masking ability of recrystallized parylene was tested in HNA (hydrofluoric acid, nitric acid and acetic acid) solution of various ratios, KOH (potassium hydroxide) solution and TMAH (tetramethylammonium hydroxide) at different temperatures and concentrations. It is found that interface between parylene and the substrate can be attacked, which results in undercuts. Otherwise, recrystallized parylene exhibited good adhesion to silicon, complete protection of unexposed silicon and silicon etching rates comparable to literature data

    A High Sensitivity Three-Dimensional-Shape Sensing Patch Prepared by Lithography and Inkjet Printing

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    A process combining conventional photolithography and a novel inkjet printing method for the manufacture of high sensitivity three-dimensional-shape (3DS) sensing patches was proposed and demonstrated. The supporting curvature ranges from 1.41 to 6.24 × 10−2 mm−1 and the sensing patch has a thickness of less than 130 μm and 20 × 20 mm2 dimensions. A complete finite element method (FEM) model with simulation results was calculated and performed based on the buckling of columns and the deflection equation. The results show high compatibility of the drop-on-demand (DOD) inkjet printing with photolithography and the interferometer design also supports bi-directional detection of deformation. The 3DS sensing patch can be operated remotely without any power consumption. It provides a novel and alternative option compared with other optical curvature sensors

    Transformation of β-Ni(OH)2to NiO nano-sheets via surface nanocrystalline zirconia coating: Shape and size retention

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    Shape and size of the synthesized NiO nano-sheets were retained during transformation of sheet-like β-Ni(OH)2to NiO at elevated temperatures via nano-sized zirconia coating on the surface of β-Ni(OH)2. The average grain size was 6.42 nm after 600 °C treatment and slightly increased to 10 nm after 1000 °C treatment, showing effective sintering retardation between NiO nano-sheets. The excellent thermal stability revealed potential application at elevated temperatures, especially for high temperature catalysts and solid-state electrochemical devices

    Tetrahedral mesh improvement by shell transformation

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    Existing flips for tetrahedral meshes simply make a selection from a few possible configurations within a single shell (i.e., a polyhedron that can be filled up with a mesh composed of a set of elements that meet each other at one edge), and their effectiveness is usually confined. A new topological operation for tetrahedral meshes named shell transformation is proposed. Its recursive callings execute a sequence of shell transformations on neighboring shells, acting like composite edge removal transformations. Such topological transformations are able to perform on a much larger element set than that of a single flip, thereby leading the way towards a better local optimum solution. Hence, a new mesh improvement algorithm is developed by combining this recursive scheme with other schemes, including smoothing, point insertion and point suppression. Numerical experiments reveal that the proposed algorithm can well balance some stringent and yet sometimes even conflict requirements of mesh improvement, i.e., resulting in high-quality meshes and reducing computing time at the same time. Therefore, it can be used for mesh quality improvement tasks involving millions of elements, in which it is essential not only to generate high-quality meshes, but also to reduce total computational time for mesh improvement

    Localization and classification of paddy field pests using a saliency map and deep convolutional neural network

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    We present a pipeline for the visual localization and classification of agricultural pest insects by computing a saliency map and applying deep convolutional neural network (DCNN) learning. First, we used a global contrast region-based approach to compute a saliency map for localizing pest insect objects. Bounding squares containing targets were then extracted, resized to a fixed size and used to construct a large standard database called Pest ID. This database was then utilized for self-learning of local image features which were, in turn, used for classification by DCNN. DCNN learning optimized the critical parameters, including size, number and convolutional stride of local receptive fields, dropout ratio and the final loss function. To demonstrate the practical utility of using DCNN, we explored different architectures by shrinking depth and width and found effective sizes that can act as alternatives for practical applications. On the test set of paddy field images, our architectures achieved a mean Accuracy Precision (mAP) of 0.951, a significant improvement over previous methods

    Risk factors for fatal candidemia caused by Candida albicans and non-albicans Candida species

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    BACKGROUND: Invasive fungal infections, such as candidemia, caused by Candida species have been increasing. Candidemia is not only associated with a high mortality (30% to 40%) but also extends the length of hospital stay and increases the costs of medical care. Sepsis caused by Candida species is clinically indistinguishable from bacterial infections. Although, the clinical presentations of the patients with candidemia caused by Candida albicans and non-albicans Candida species (NAC) are indistinguishable, the susceptibilities to antifungal agents of these species are different. In this study, we attempted to identify the risk factors for candidemia caused by C. albicans and NAC in the hope that this may guide initial empiric therapy. METHODS: A retrospective chart review was conducted during 1996 to 1999 at the Veterans General Hospital-Taipei. RESULTS: There were 130 fatal cases of candidemia, including 68 patients with C. albicans and 62 with NAC. Candidemia was the most likely cause of death in 55 of the 130 patients (42.3 %). There was no significant difference in the distribution of Candida species between those died of candidemia and those died of underlying conditions. Patients who had one of the following conditions were more likely to have C. albicans, age ≧ 65 years, immunosuppression accounted to prior use of steroids, leukocytosis, in the intensive care unit (ICU), and intravascular and urinary catheters. Patients who had undergone cancer chemotherapy often appeared less critically ill and were more likely to have NAC. CONCLUSION: Clinical and epidemiological differences in the risk factors between candidemia caused by C. albicans and NAC may provide helpful clues to initiate empiric therapy for patients infected with C. albicans versus NAC

    Reassortment and Mutations Associated with Emergence and Spread of Oseltamivir-Resistant Seasonal Influenza A/H1N1 Viruses in 2005–2009

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    A dramatic increase in the frequency of the H275Y mutation in the neuraminidase (NA), conferring resistance to oseltamivir, has been detected in human seasonal influenza A/H1N1 viruses since the influenza season of 2007–2008. The resistant viruses emerged in the ratio of 14.3% and quickly reached 100% in Taiwan from September to December 2008. To explore the mechanisms responsible for emergence and spread of the resistant viruses, we analyzed the complete genome sequences of 25 viruses collected during 2005–2009 in Taiwan, which were chosen from various clade viruses, 1, 2A, 2B-1, 2B-2, 2C-1 and 2C-2 by the classification of hemagglutinin (HA) sequences. Our data revealed that the dominant variant, clade 2B-1, in the 2007–2008 influenza emerged through an intra-subtype 4+4 reassortment between clade 1 and 2 viruses. The dominant variant acquired additional substitutions, including A206T in HA, H275Y and D354G in NA, L30R and H41P in PB1-F2, and V411I and P453S in basic polymerase 2 (PB2) proteins and subsequently caused the 2008–2009 influenza epidemic in Taiwan, accompanying the widespread oseltamivir-resistant viruses. We also characterized another 3+5 reassortant virus which became double resistant to oseltamivir and amantadine. Comparison of oseltamivir-resistant influenza A/H1N1 viruses belonging to various clades in our study highlighted that both reassortment and mutations were associated with emergence and spread of these viruses and the specific mutation, H275Y, conferring to antiviral resistance, was acquired in a hitch-hiking mechanism during the viral evolutionary processes
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