187 research outputs found
Short-term electric load forecasting using computational intelligence methods
Accurate time series forecasting is a key issue to support individual and organizational decision making. In this paper, we introduce several methods for short-term electric load forecasting. All the presented methods stem from computational intelligence techniques: Random Forest, Nonlinear Autoregressive Neural Networks, Evolutionary Support Vector Machines and Fuzzy Inductive Reasoning. The performance of the suggested methods is experimentally justified with several experiments carried out, using a set of three time series from electricity consumption in the real-world domain, on different forecasting horizons
Crystallization kinetics as a sensitive tool to detect degradation in poly(lactide)/poly(ε-caprolactone)/ PCL-co-PC copolymers blends
Poly(lactide)/poly(ε-caprolactone) blends (PLA/PCL) with composition 80/20 (w/w%) are immiscible but biodegradable and therefore often studied in the literature. We have prepared 80/20 PLA/PCL blends with and without poly(ε-caprolactone)-co-poly(carbonate) copolymers (block and random). The blends were prepared both by melt extrusion and by solution blending. The concentration of PCL-co-PC copolymers added to the blends was 2 wt%. Compression molded sheets and solvent cast films were evaluated by GPC (Gel Permeation Chromatography), TGA (Thermogravimetric Analysis), SEM (Scanning Electron Microscopy), PLOM (Polarized Light Optical Microscopy) and DSC (Differential Scanning Calorimetry). Copolymer addition causes a reduction of molecular weight in melt mixed blends. In particular, the random copolymer (PCL-ran-PC) causes the highest molecular weight reduction, since it has lower thermal stability, as shown by TGA. PLOM experiments show that these degraded PLA chains in melt-mixed blends can nucleate and grow faster than similar but undegraded PLA chains in solution-mixed blends. As a result, the PLA phase within melt mixed blends containing PCL-co-PC copolymers shows a higher tendency to crystallize during both isothermal and non-isothermal DSC experiments. Upon molecular weight reduction in melt mixed blends containing copolymers, PLA chains have a higher mobility resulting in faster diffusion towards the growing crystal front. Our results show crystallization kinetic measurements, performed by PLOM or DSC, are useful tools to qualitatively detect molecular weight changes produced by degradation of PLA chains, when the molecular weight reduction is not large enough to decrease Tm values
Design and integration of WAAM technology and in situ monitoring system in a gantry machine
Wire arc additive manufacturing, WAAM, is a popular wire-feed additive manufacturing technology that creates components through the deposition of material layer-by-layer. WAAM has become a promising alternative to conventional machining due to its high deposition rate, environmental friendliness and cost-competitiveness. In this research work, an adaptation of a gantry machine with in-situ monitoring and a control system has been carried out, in order to expose the ability of the WAAM technology to fabricate complex-shaped parts. The retrofitting of the machine has been done in several layers called respectively hardware, control and software layers. For the validation of the implemented system, a stainless steel 316L demonstrator has been manufactured, and the required stages have been employed, including part design (CAD), process parameters selection, tool-path definition (CAM) and part manufacturing. This study has shown the feasibility of the adapted machine for additive manufacturing as a controlled process.The authors acknowledge the European Commission for support from project AMAZE (FP7-2012-NMP-ICT-FoF,
project 313781) and the Basque Government for support from project EUSK-ADDI (Etorgai 2014)
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The Rite of Passage and Digital Mourning in Fang Fang's Wuhan Diary
Using Van Gennep’s theory of Rite of Passage as its framework, this article examines the impact of Coronavirus (COVID-19) on Chinese culture as depicted through death and mourning in Wang Fang’s (penname Fang Fang) recently published Wuhan Diary: Dispatches from a Quarantined City. As part of the efforts to control the outbreak, the Chinese government took over the managing of the deceased, which triggered heated discussions on Chinese social media. Fang Fang’s diary, originally written as daily entries on Chinese social media platform Weibo, serves as a voice for those suffering during the pandemic, mediating between personal accounts, accounts of friends, family and those living in Wuhan during the pandemic. These flesh out how the virus has not only been disturbing for Chinese people’s lives but also disrupted the death rites and mourning rituals for those who have passed. Our article infuses a digital ontological reading with an anthropological twist that helps to understand how the diary mitigates the disturbances to mourning rituals inside and outside the confines of digital metaphysics. We argue that the digital diary mitigates these disruptions by allowing Chinese people to nourish their sorrow by identifying with the symbolic rites of passage and mourning rituals online at the heart of the COVID-19 pandemic in Wuhan. In doing so, this article examines three stages of rite of passage, including separation, liminality and integration as they unfold in the diary, through which discourses and subjectivities based on collective and individual traumatic experiences are built, as a form of digital mourning that could reconcile both the official and the alternative voices of anonymous narratives about the handling of this crisis
Unboxing the Chinese Blind Boxes among China's grown-up missing children: Probabilistic and elastic prosumption through mediated collection, exchange and resale of figurines
This paper situates the ‘Blind Box’ consumption, collection and prosumption practices in China within globalisation and the ‘media-mix’ fandom, which is to consume and resell media merchandise in opaque packages as probability goods. We re-centre the focus of fandom studies on the then much neglected ‘missing child’ and now the ‘emerging adult’ in a globalising world. We argue the Chinese emerging adult consumes, collects and resells Blind Boxes as a generative and agentic collection and fandom practice, defined as ‘probabilistic and elastic prosumption’ in a quasi-social and quasi-individual manner. We then critically examine and unpack the cultural production and meaning making process undertook by collectors who also accumulate sociality and form identity through affective and economic investments, mediated collection and exchange of figurines in a post-socialist and consumerist society
In vitro antiatherogenicity of extracts from Halimeda incrassata seaweed: antioxidant activity and smooth muscle cell migration studies
Aim: The aim of this work was to evaluate the in vitro atheroprotective potential of the seaweed Halimeda incrassata in smooth muscle cell migration and lipoprotein oxidation in relation to its antioxidant activity.
Material and methods: Antioxidant activity was determinate by DPPH• radical scavenging assay and ORAC method. The inhibitory effect of the aqueous extract on LDL oxidation mediated by Cu2+ ions was determinate by TBARS and conjugated diene quantification. The effect of the seaweed aqueous extract on smooth muscle cell migration was evaluated in MOVAS-1 mouse aortic smooth muscle cell.
Results: The inhibitory effect of the aqueous extract on lipoprotein oxidation mediated by Cu2+ was demonstrated. Seaweed extract caused dose-dependent inhibition of TBARS (IC50 = 0.8 mg/mL) and conjugated dienes formation. The seaweed had a high antioxidant activity in the assays performed. The activity could be related to the phenolic content of Halimeda incrassata.
Conclusions: In summary, the results of this study represent a further step in the characterization of the atheroprotective action of Halimeda incrassata and indicate the seaweed could be used for a nutraceutical and/or phytoterapeutic application.Objetivos: El objetivo de este trabajo fue evaluar el potencial ateroprotector in vitro del alga Halimeda incrassata en la migración de células de músculo liso de ratón y la oxidación de lipoproteínas en relación con su actividad antioxidante.
Material y métodos: La actividad antioxidante fue determinada mediante los métodos de inhibición de radicales DPPH y la Capacidad antioxidante total (ORAC). La actividad inhibitoria de la oxidación de LDL mediada por iones Cu2+ se determinó por la cuantificación de TBARS y dienos conjugados. El efecto del extracto acuoso sobre la migración de las células de músculo liso se evaluó en la línea de células de músculo liso aórtica de ratón MOVAS-1.
Resultados: Se demostró el efecto inhibidor del extracto sobre la oxidación de LDL mediada por Cu2+. El extracto del alga causa inhibición dosis-dependiente de la formación de TBARS (IC50 = 0,8 mg/mL) y dienos conjugados. Las algas tuvieron una alta actividad antioxidante en los ensayos realizados y podría estar relacionada con el contenido de compuestos fenólicos.
Conclusiones: Los resultados de este trabajo representan un paso más en la caracterización de la acción ateroprotectora de Halimeda incrassata y evidencian sus posibles aplicaciones como nutracéutico y/o fitofármaco.The research was funded by IFS grant
F/4897-1. Partial funding was also provided
by CIHR grant MOP24447, the Canadian
Research Chair award (D.B.) and a personal
grant from GSEP, offered by the Canadian
Bureau for International Education (A.C) and
CNPq- (Brasil)
Reducción de vibraciones en una rectificadora sin centros mediante la utilización de actuadores piezoelectricos
National audienceEn el presente artículo se describe la realización práctica de un sistema de reducción de vibraciones de chatter en una rectificadora sin centros, utilizando actuadores piezoeléctricos. El trabajo presentado complementa aquél de carácter teórico y generalista presentado en la pasada edición de este mismo congreso. Se describe la metodología seguida para la definición del tipo de control a utilizar y los criterios seguidos para definir la localización de los actuadores piezoeléctricos. El trabajo incluye la elaboración de un modelo para reflejar el comportamiento dinámico de la máquina para el rango de frecuencias de interés, dando así pie a la realización de distintas simulaciones que permitieron definir las características que deberían disponer los actuadores disponibles comercialmente. Se ha implementado una estrategia de control activo del amortiguamiento, utilizando controladores de realimentación proporcionales. Se presentan los resultados obtenidos en los ensayos de mecanizado una vez implantado el sistema en la máquina. Se ha conseguido un sistema que permite reducir los picos de resonancia de los modos que causan chatter, lo que causa un importante aumento del umbral de estabilidad de la máquina
Relación entre porosidad y propiedades mecánicas en tracción de aleaciones de aluminio de moldeo. Estado del conocimiento
Neuropathology of neurocutaneous melanosis: histological foci of melanotic neurones and glia may be undetectable on MRI
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