1,721,159 research outputs found
Water-soluble stabilizer for speckle pattern fabrication
No full textThis work aims to provide a quick solution for impressing a well-defined and repeatable speckle pattern on the surface of a material sample. The proposed technique is based on a water-soluble stabilizer on which the speckle pattern generated and optimized via computer is printed. To verify the application, a two-dimensional (2D) digital image correlation (DIC) system is employed to measure the full-range strain distribution at the macroscopic level during a tensile test on open-hole aluminum specimen. The experimental setup consists mainly of an action camera, a macro lens, and an open-source 2D DIC software. The measured data obtained from the DIC are compared to the other ones provided both from a traditional measurement method based on strain gauge and by a numerical simulation. The results indicate that the approach is both accurate and reliable to obtain stress-strain curves especially in the presence of plastic deformations
Preliminary results of FMCW radar measurements at 60GHz for ice build up detection on the surface of a composite panel
No full textRenewable energy sources have gained much attention due to the urge to get clean energy. Among the main options being studied, wind energy is a strong contender because of its reliability thanks to the maturity of the technology and relative cost competitiveness. In order to harvest wind energy more efficiently and to improve safety considerations, the wind turbines blades must be monitored regularly to ensure that they are in good condition. This is even truer in cold climate areas where, because of sub-zero temperatures and humid environment for larger periods of the year, icing represents a significant threat to the performance and durability of wind turbines. Therefore, a structural health monitoring (SHM) system is of primary importance. Recently, there has been a significant interest in employing high frequency radar imagery for Non-Destructive Testing (NDT) and Non-Destructive Evaluation (NDE). The main motivations for using this technology are: it allows penetration of most non-metal and non-polarized materials, it provides the ability for in-depth information, and the millimeter waves pose no health risk to the operator. The main goal of this research is to check the ability of a frequency-modulated continuous-wave (FMCW) radar in performing real-time ice detection onto a glass fibre plate when it works in the frequency band from 57-64 GHz. The technology effectiveness to achieve the aforesaid task is proved in a climatic chamber under controlled humidity and thermal conditions
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variations on the Author
Full text link“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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Use of flashlamp-pumped pulsed dye laser in the treatment of superficial vascular malformations and ulcerated hemangiomas
No full textA retrospective study of 502 patients treated with tunable flashlamp pulsed dye laser for superficial vascular malformations (433), ulcerated hemangiomas (65) and postinvolutional redness (4) is presented. Patients were treated in the period from June 1997 to March 2006, with follow-up ranging from six months to four years. The age of the patients ranged from three months to 80 years. Correlation between clinical response and patients' age, location of lesion and number of treatments were evaluated in groups of superficial vascular malformations, whereas healing rates of the ulceration were assessed in a series of hemangiomas. The result were judged to be excellent in 51%, good in 39%, fair in 7% and poor in 3% of patients with vascular malformations. Excellent ultimate outcome confirmed the clinical efficacy of the use of the pulsed dye laser in the treatment of dermal vascular malformations, which also appears to have good prospects in the management of hemangioma complication
Modeling organizational learning through intelligent agents based systems: an Ant Colony Optimization simulation model
No full text
On ultrasound propagation in composite laminates: advances in numerical simulation
Full text linkThe growing use of composite materials for aerospace applications has resulted in the need for quantitative methods to analyze composite components. Ultrasonic guided waves constitute the physical approach for nondestructive evaluation (NDE) and structural health monitoring (SHM) of solid composite materials, such as carbon fiber reinforced polymer (CFRP) laminates. Ultrasound based NDE methods are commonly used in the aerospace field, but ultrasonic wave behavior can be complicated by the presence of material anisotropy, complex geometries (e.g., highly curved parts, stiffeners, and joints) and complex geometry defects. Common defects occurring in aerospace composites include delaminations, porosity, and microcracking. Computational models of ultrasonic wave propagation in CFRP composites can be extremely valuable in designing practical NDE and SHM hardware, software, and methodologies that accomplish the desired accuracy, reliability, efficiency, and coverage. Physics based simulation tools that model ultrasonic wave propagation can aid in the development of optimized inspection methods and in the interpretation of NDE data. This paper presents a review of numerical methodologies for ultrasound and guided wave simulation in fiber reinforced composite laminates summarizing the relevant works to date, different methods, and their respective applications
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