689 research outputs found
El reyezuelo, el cuervo y el dios céltico Lug : aspectos del dossier ibérico
Partimos de un dossier formado por testimonios muy heterogéneos antiguos, medievales o folclóricos analizados con una metodología estructural. El eje es la relación existente entre el reyezuelo y el cuervo por su pertinencia en la definición de espacios sagrados, relaciones entre hombres y dioses, jerarquías entre los hombres. Pero ambas aves se relacionan también, de forma específica, con el dios céltico Lug. Pero el culto a este dios no ha dejado muchas trazas expresas en la antigüedad, aunque si en las tradiciones insulares medievales. Se sostiene que tradiciones continentales sobre esas aves, y de forma particular concernientes a su relación con S. Vicente, pueden ser huellas más o menos transformadas de un antiguo culto a Lug. Como colofón se examinan testimonios icónicos pertinentes para este dossier y se muestra la importancia de los santuarios costeros localizados en toda la fachada atlántica desde el Cabo San Vicente hasta Bretaña y Gran Bretaña relacionados, se sugiere, con la cosmovisión y concepciones sobre el más allá célticas._______________________________Our starting point will be a very
heterogeneous dossier composed by
ancient, medieval or folkloric texts to
be studied with the aid of a structural
methodology. The main point is the
relationship between the wren and the
raven and its usefulness for the
definition of sacred spaces, the
relationships between men and gods,
and the hierarchies among men. Both
birds are also related to the Celtic god
Lug. The problem we must face is that
Lug in Antiquity is not a very well
known god, in opposite to the Irish and
Welsh medieval traditions. This paper
proposes that the continental traditions
about these birds, and in particular
those related to the Palaeo-Christian
Saint Vincent, can be more or less clear
traces of the ancient cult devoted to
Lug. Lastly, some images are examined
as pertinent to our dossier and the
interest and importance of the coastal
sanctuaries all along the Atlantic coast
is stressed, from Cape St. Vincent to
Brittany and Great Britain, all of them
related, as it is suggested, to the Celtic
world view and the Celtic ideas about
the Other World
Nanostructured nickel film deposition on carbon fibers for improving reinforcement-matrix interface in metal matrix composites
The issues in dispersing any form of carbon in metal matrix is the major problem in the field of metal matrix
composites with carbon reinforcement (MMCcr). The low wettability of carbon in molten metals and the
difference in density are some of the difficulties to obtain a good dispersion of carbon fibers in the matrix and,
as a consequence, an improvement of some critical properties for metals in a wide range of application
(mechanical properties, electrical properties, optical properties). For this reason, the aim of this work is to
obtain a metallic coated carbon fiber to enhance the interaction between the reinforcement and the matrix.
Moreover, also the density of carbon fibers could be adjusted depending on the thickness of the coating.
Electroless Nickel-Phosphorus Plating (ENP) is one of the candidate to be a coating technique to improve the
interaction between the carbon fibers and the metal matrix. Despite of its versatility in terms of complex
geometry of the substrate and homogeneity and adhesion of the coating, the presence of the phosphorus in
the alloy could create some problems with the metal matrix such as the formation of metal-phosphorus
products that can drastically decrease the mechanical properties of the composite. For this reason, in this
work, is presented a new way of Electroless Pure Nickel Plating (EPP) without any introduction of phosphorus
in the nickel coating. The dependence of the coating thickness and the density of the coated fibers were
studied under different plating parameters (temperature of the plating solution, deposition rate and plating
solution composition). All the samples were characterized with SEM and XRD and the thickness, density and
homogeneity were compared for all the samples obtained
Dumézil, Momigliano, Bloch, between politics and historiography
Discusión de la atribución al historiador de las religiones G. Dumézil (1898-1986) de ideas filo-nazis que se reflejarían en sus estudio
Lightweight metallic matrix composites. Development of new composites material reinforced with carbon structures
Carbon nano/micro-structures used as fillers in metallic lightweight alloys matrix composites are receiving considerable attention in scientific research and industrial applications. Aluminum and magnesium are the most studied light metals used as matrices in metal composites materials principally for their low density (respectively 2.7 g/cm3 and 1.7 g/cm3) and low melting temperature (around 660 °C for both metals). A good interaction between matrix and fillers is the first step to obtain an increase in bulk properties; furthermore, the manufacturing procedure of the composite is fundamental in terms of quality of fillers dispersion. In this work the influence of surface modifications for three classes of carbon fillers for aluminum and magnesium alloy (AZ63) as matrices is
studied. In particular, the selected fillers are short carbon micro fibres (SCMFs), carbon woven fabrics (CWF) and unidirectional yarn carbon fibres (UYFs). The surface modification was carried out by a direct coating of pure nickel on fibres. The electroless pure nickel plating was chosen as coating technique and the use of hydrazine as reducing agent has prevented the co-deposition of other elements (such as P or B). SEM and EDS analyses were performed to study the effect of surface modifications. The mechanical properties of manufactured composites were evaluated by four point flexural tests
according to ASTM C1161 (room temperature). Results confirm improved interactions
between matrix and fillers, and the specific interaction was studied for any chosen
reinforcement
Sedimentary facies and foraminiferal assemblages from Posidonia oceanica meadows of western Mediterranean Sea
Autoimmunity and otolaryngology diseases
Many systemic autoimmune diseases have otolaryngology manifestations that could represent a diagnostic challenge for clinicians, as they often constitute an early sign of an otherwise asymptomatic autoimmune condition and may lead to delayed diagnosis and treatment. In other cases, otolaryngology manifestations can be overlooked in patients with previously diagnosed autoimmune diseases. The pres- ence of concomitant conditions, the heterogeneity of studies available in the literature, and the lack of randomized trials are factors that may limit the prompt diagnosis of otolaryn- gology manifestations in systemic autoimmune diseases, with underestimation of the problem and undertreatment of the related condition
How I turned my kitchen in a lab during the pandemic and its (non-)icy outcomes
Unwanted icing has major safety and economic repercussions on human activities, affecting means of transportation, infrastructures, and consumer goods. Compared to the common deicing methods in use today, intrinsically icephobic surfaces can decrease ice accumulation and formation without any active intervention from humans or machines. However, such systems often require complex fabrication methods and can be costly, which limits their applicability.
In this study, we report the preparation and characterization of a series of slippery lubricant-infused porous surfaces (SLIPSs) realized by impregnating with silicone oil a candle soot layer deposited on double-sided 3M adhesive tape.
Despite the use of common household items, these SLIPSs showed anti-icing performance comparable to other systems described in the literature (ice adhesion < 20 kPa) and a good resistance to mechanical and environmental damages.
To improve the overall performances, we explored several design solution involving surface functionalization of the inner pores and the use of fluorinated lubricants.
The use of a flexible and functional substrate as tape allowed these devices to be stretchable without suffering significant degradation and highlights how these systems can be easily prepared and applied anywhere needed. In addition, the possibility of deforming the substrate can pave the way for the application of SLIPS technology in mechanical ice removal methodologies, drastically incrementing their performanc
Letter to the editor: autoimmune pathogenic mechanisms in Huntington’s disease
Letter to the Editor: Autoimmune pathogenic mechanisms in Huntington's disease
- …