1,721,119 research outputs found

    The Impact of Fused Filament Fabrication (FFF) Printing Profiles on 17-4 PH Green and Sintered Parts

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    The aim of this research is to characterize parts from innovative hybrid printing method for obtaining dense metal components using affordable fused filament fabrication (FFF). The introduction of Desktop Metal technology in 2015 really attracts an increase in industrial interest in the FFF printing of highly metal-filled filament. Even though FFF is a well-known process, there are not many studies on how to optimize the printing parameters for these feedstocks. The effects of the printing setting on producing high-quality green parts and enhancing the mechanical properties of the finished 17-4 PH metallic parts are investigated in this work. The influence of four printing profiles provided by a BASF plugin for Ultimaker Cura slicing software, obtained by combining different printing parameters is investigated. The ASTM E8 tensile test is used to determine the mechanical characteristics of the finished metal components. To identify differences in morphology, optical and scanning electron microscopy (SEM) observations are made on both sections of green and sintered samples. The effect of printing parameters on shrinkage and density are also taken into consideration. The findings demonstrate the importance of optimizing the printing of the green parts in order to produce full metal components that are both strong and dense

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Plasma deposition of amorphous SiC:H,F alloys from SiF4-CH4-H-2 mixtures

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    Fluorinated and hydrogenated amorphous silicon-carbon alloys (n-SiC:H,F) are produced by glow discharge decomposition of SiF4-CH4-H-2 mixture. Small amount of CH4 in SiF4-H-2 mixture are enough to produce silicon carbon alloys having optical gap ranging between 1.8 and 2.6 eV. Materials, having 1.95 eV band gap and exhibiting optoelectronic properties typical of state of art a-SiC:H, are deposited under plasma modulation conditions

    Morphological and structural study of plasma deposited fluorocarbon films at different thickness

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    The growth of fluorocarbon thin films has been obtained by continuous and modulated r.f. plasmas fed with C2F4. The kinetics surface morphology of the coatings has been investigated and analyzed on films of various thicknesses. Such a study has allowed the evolution of structures in size and shape to be followed. Specifically, it has been observed that modulated plasmas with the proper duty cycles (less than or equal to7%) lead to the formation of micrometer-long ribbon-shaped nanostructures. The precursors of the ribbons are nuclei that align into a spiral-mimic. Highly nanostructured films with an optimal thickness and ribbon density exhibit a super-water repellent surface with contact angles up to 170degrees. The surface roughness and smoothing of fluorocarbon films are strongly affected by the modulated and continuous plasmas, respectively

    What did we learn from new treatments in SMA? A narrative review

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    Spinal Muscular Atrophy (SMA) is a progressive neuromuscular disorder caused by SMN1 gene mutations, leading to inevitable motoneuronal degeneration. The introduction of disease modifying therapies has dramatically altered its natural history, shifting management from palliative to proactive approach. The new phenotypes and differences in treatment response and efficacy, are all contributing to reshape our understanding of the disease itself. This paper aims to analyze the lessons derived from the recent therapeutic advances, focusing on key aspects such as therapeutic windows, impact of early treatment and both disease progression and treatment efficacy modifiers. Ultimately, we also aim to give insights on new models of data analysis being explored to optimize patient trajectories and individualize treatment strategies. Our experience and the overall review of clinical trials and real-world data confirm that early treatment maximizes motor outcomes, especially when started in the pre-clinical phase of the disease. The significant clinical improvements in symptomatic type I infants treated at different ages has provided evidence of an expanded ‘therapeutic window’, previously reported as limited to the first few months after birth on the basis of neurophysiological findings. The available data also provide evidence that function at baseline, SMN2 copy number, and age at treatment all appear to represent critical determinants of response. The availability of long-term data is increasingly used to pilot new predictive models to support clinical decision-making and to adapt therapeutic goals based on patient-specific variables

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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