139,452 research outputs found
The Major and Minor Relaxations in Polymeric Ni-Zn-Cu-Co Complex Nanocomposite Systems
No full textNanocrystalline polymeric complex (Ni0.5Zn0.4Cu0.1) ferrite substituted cobalt (Co) ferrite system has been synthesized by chemical co precipitation method. The dielectric properties of polymeric spinel ferrite system (Ni0.5Zn0.4Cu0.1Fe2O4)(x)(CoFe2O4)(1-x) have been investigated. Some of the dielectric parameters such as dielectric permittivity epsilon' and loss tangent (tan delta) were studied as a function of frequency in the range 1 Hz-1 MHz and of temperature in the range 230-410 K. Excessive dependency of dielectric properties on frequency and temperature with the presence of two relaxation mechanisms, which are called as major and minor, have been observed. From Argand diagram analysis alpha and Delta epsilon values for these two kinds of relaxation curves have been determined for all the samples in the measured temperatures. The reported dielectric properties are thought to be meaningful for future applications
Influence of microwave heating on quality parameters and chemical characteristics of Turkish olive oils
No full textMicrowave use has become quite common and microwave ovens are being used increasingly due to their fast heating technology. In this study, the effects of microwave heating on the deterioration of olive oil quality parameters like free fatty acidity, peroxide value, ultraviolet absorbance values (K232, K270) and also antioxidant compounds as chlorophyll and carotenoid content, alpha-tocopherol content, total phenolic content in addition oxidative stability and DPPH center dot radical scavenging activity which are related to chemical characteristics of Turkish olive oils, were investigated, at different times of the microwave treatment, in 2015/16. All analytical data were processed through univariate and multivariate data analysis (Principal Component Analysis). It was determined that heating time significantly influences quality parameters and chemical characteristics. This heating treatment produces significant losses in olive oil quality parameters and also in bioactive components. Therefore, heating time should be reduced to minimum to preserve olive oil nutritional content
Operation-dependent exergetic sustainability assessment and environmental analysis on a large tanker ship utilizing Organic Rankine cycle system
No full textThis study focuses on the novel perspective of marine ORC systems with a detailed marine diesel generator plant simulation integrated with an ORC system model to evaluate environmental impacts and energy efficiency increments by reducing the number or the load of generators by using the ORC system support during operation. It is aimed to analyze the fuel-saving potential and sustainability performance of the power generation plant of a tanker ship when an ORC is integrated. The thermodynamic system simulation determined the fuel consumption of the plant within two years regarding six operation modes. The results show that the optimum working fluid is R1336mzz (Z) for the evaporation pressure of 16 bar. Organic Rankine cycle system integration provided a total fuel-saving of 15% from diesel generators and the total fuel consumption of the vessel was reduced by 5.16%. The sustainability performance of the system was ensured with a novel operation-dependent approach that enhances the exergetic sustainability assessment by considering the operation modes of the vessel and the time spent on these operations for a certain time. The load reduction in the generators resulted in better sustainability performance and the operation-dependent indicators were affected by operations having more working hours.</p
Spatially-localized time dependent solutions including turbulence and their interactions in 2D Kolmogorov flow
No full textIn 2D Kolmogorov flow in small aspect ratio domains, spatially-localized solutions such as kink, traveling or time-dependent kink-antikink pars coexist. However, the conservation of the flow rate in the y direction strongly restrict combination of localized solutions and their positioning. We find that by adding a homogeneous flow U y their positioning is controlled and each of localized solutions including a spatially-localized chaos is isolated. Numerical results suggest that these isolated solutions can be elements constructing a whole flow
Characteristics of overlap region in high-Reynolds number turbulent channel flow
No full textDirect numerical simulation of the fully developed turbulent channel flows have been carried out at the Reynolds number based on the friction velocity and the channel half width, 2000, 4000 and 8000. A hybrid 10th order accurate finite difference scheme in the stream and spanwise directions, and a second-order scheme in the wall-normal direction is adapted as the spatial discretization method. We observed the plateau profiles in the indicator function corresponded to the von Karman constant. Furthermore, second peak of streamwise pre-multiplied spectra were appeared in the same wall normal height, 300 < y+ < 600, in case of Re = 4000. Nevertheless, the effects of the lager than the channel half height scale on the streamwise turbulent intensity are fixed contributions without dependence on Reynolds number. These results suggested that the new streamwise vortexes are formed between buffer layer and outer layer with increasing of Reynolds number
La 'circunstancia' de 'Herederos y Pretendientes
No full textIn June 2010, the Ortega y Gasset Foundation hosted a Conference about the “Spanish Philosophical Transition” in order to debate the book of Francisco Vázquez, La filosofía española. Herederos y Pretendientes. Una lectura sociológica (1963-1990), recently published. This paper is the author’s response to criticism raised in the Conference and to published reviews received by this book. First, the author summarized the argument of Herederos y pretendientes. Secondly he responds and takes into account the most important objections against the book’s hypothesis and methodology. Finally the author evaluates the favorable judgments received by the book and suggests the limits of the historian’s task.Fundación Ortega y Gasset-Marañó
Author self-citation in orthodontics is associated with author origin and gender.
No full textBACKGROUND
The aims of this bibliometric study were to determine author self-citation trends in high-impact orthodontic literature and to investigate possible association between self-citation and publication characteristics.
METHODS
Six orthodontic journals with the highest impact factor as ranked by 2017 Journal Citation Reports were screened for a full publication year (2018) for original research articles, reviews, and case reports. Eligible articles were scrutinized for article and author characteristics and citation metrics. Univariable and multivariable negative binomial regression was used to examine associations between self-citation incidence and publication characteristics.
RESULTS
Medians for author self-citation rate of the most self-citing authors and self-citations were 3.03% (range 0-50) and 1 (range 0-19), respectively. In the univariable analysis, there was no association between self-citation counts and study type (P = 0.41), article topic (P = 0.61), number of authors (P = 0.62), and rank of authors (P = 0.56). Author origin (P = 0.001), gender (P = 0.001) and journal (P = 0.05) were associated with self-citation counts and in the multivariable analysis only origin and gender remained strong self-citation predictors. Asian authors and females self-cited significantly less often than all other regions and male authors.
CONCLUSIONS
Authors in orthodontics do not self-cite at a frequency that suggests potential citation manipulation. Author origin and gender were the only variables associated with citations counts. More bibliometric research is necessary to draw solid conclusions about author self-citation trends in orthodontic literature
Overview of the Author Profiling Task at PAN 2013
No full text[EN] This overview presents the framework and results for the Author Profiling
task at PAN 2013. We describe in detail the corpus and its characteristics,
and the evaluation framework we used to measure the participants performance to
solve the problem of identifying age and gender from anonymous texts. Finally,
the approaches of the 21 participants and their results are described.The author profiling task @PAN-2013 was an activity of the WIQ-EI IRSES project (Grant No. 269180) within the FP 7 Marie Curie People Framework of the European Commission. We want to thank the Forensic Lab of the Universitat Pompeu Fabra Barcelona for sponsoring the award for the winner team. The work of the first author was partially funded by Autoritas Consulting SA and by Ministerio de Economía y Competitividad de España under grant ECOPORTUNITY IPT-2012-1220-430000. The work of the second author was in the framework the DIANA-APPLICATIONS-Finding Hidden Knowledge in Texts: Applications (TIN2012-38603-C02-01) project, and the VLC/CAMPUS Microcluster on Multimodal Interaction in Intelligent Systems. The work of fifth author was funded in part by the Swiss National Science Foundation (SNF) project "Mining Conversational Content for Topic Modelling and Author Identification (ChatMiner)" under grant number 200021_130208.Rangel, F.; Rosso, P.; Koppel, M.; Stamatatos, E.; Inches, G. (2013). Overview of the Author Profiling Task at PAN 2013. CLEF Conference on Multilingual and Multimodal Information Access Evaluation. 352-365. https://riunet.upv.es/handle/10251/46636S35236
Author Co-Citation Analysis (ACA): a powerful tool for representing implicit knowledge of scholar knowledge workers
No full textIn the last decade, knowledge has emerged as one of the most important and valuable organizational assets. Gradually this importance caused to emergence of new discipline entitled ―knowledge management‖. However one of the major challenges of knowledge management is conversion implicit or tacit knowledge to explicit knowledge. Thus Making knowledge visible so that it can be better accessed, discussed, valued or generally managed is a long-standing objective in knowledge management. Accordingly in this paper author co- citation analysis (ACA) will be proposed as an efficient technique of knowledge visualization in academia (Scholar knowledge workers)
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