Avangarda revizitată (I)

There is plain filiation between the atmosphere and the general configuration of the movements we call the historical Avant-Garde and the spirit of the revolutionary Romanticism. Literary theorists and critics brought it to the fore, both organically – insofar as the similarities between the two paradigms are spelled out by the dynamics of the history of sensibility and taste – and typologically, in its mythological and thematic redundancies, in reiterating acute polemical gestures and attitudes or in manifesting violence against tradition. This study aims to articulate the artistic and political duality defining these two artistic paradigms, by using comparative evaluation and by illustrating canonical notions such as subject, revolution, progress.

On the Electro-Mechanical Stability of Elastomeric Coaxial Fibers

The stability of cylindrical coaxial fibers made from soft elastomeric materials is studied for electro-static loadings. The general configuration considered is a three-component axisymmetric fiber having a conducting core bonded to a dielectric annulus in turn bonded to an outer conducting annular sheath. A voltage difference between the conducting components is imposed. The stresses and actuated elongation in the perfectly concentric fiber are analyzed, and the critical voltage at which stability of the concentric configuration is lost is determined via solution of the non-axisymmetric bifurcation problem. The role of the geometry and moduli contrasts among the components is revealed, and the sub-class of two-component fibers is also analyzed. The idealized problem of a planar layer with conducting surfaces that is bonded to a stiff substrate on one surface and free on the other exposes the importance of short wavelength surface instability modes.

Global monopole as a generator of a bulk-brane structure in Brans–Dicke bulk gravity

We investigate a braneworld model generated by a global monopole in the context of Brans–Dicke gravity. After solving the dynamical equations we found a model capable to alleviate the so-called hierarchy problem. The obtained framework is described by a hybrid compactification scheme endowed with a seven-dimensional spacetime, in which the brane has four non-compact dimensions and two curled extra dimensions. The relevant aspects of the resulting model are studied and the requirements to avoid the well known seesaw-like behavior are discussed. We show that under certain conditions it is possible to circumvent such a pathological behavior that characterizes most of the models that exhibit hybrid compactification. Lastly, we deepen our analysis by considering possible extensions of this model to a setup with multiple branes and orbifold-like extra dimension. For this, we compute the consistency conditions to be obeyed by this more general configuration as predicted by the braneworld sum rules formalism. This study indicates the possibility of exclusively positive brane tensions in the model.

A new species of the porcelain crab genus Petrolisthes from the Pacific coast of Panama, with taxonomic notes on closely related species (Decapoda: Anomura: Porcellanidae)

A new species of porcelain crab, Petrolisthes lazarus sp. nov., is described from the Pacific coast of Panama, based on two female specimens. The new species is morphologically most similar to another eastern Pacific species, P. crenulatus Lockington, 1878, especially in the general configuration of the carapace, chelipeds and ambulatory legs. However, P. lazarus sp. nov. can be separated from P. crenulatus by the differences in the proportions of the carapace, the shape of the frontal region of the carapace, and the setation pattern of the cheliped. In addition, P. lazarus sp. nov. and P. crenulatus appear to be allopatric, the latter species presently being known only from Mexico. Among other eastern Pacific taxa, P. lazarus sp. nov. may have some affinities with P. ortmanni Nobili, 1901 and P. lewisi (Glassell, 1936), from which it can be easily distinguished by the chelipeds lacking a dense field of setae on the outer (lateral) surface of the palm and with different proportions of some articles, especially the carpus. The four species can also be distinguished from each other by their diagnostic, although somewhat variable colour patterns.

Perovskite Structured Nanomaterials: An Advanced Key for Global Development of Nanotechnology

Starting with a history of the fundamental science, currently, the perovskite structures exemplify the extensive manifestation of crystal chemistry which is associated with the smart synthesis techniques to develop a new type of material. The perovskite structures exhibit the most efficient single accomplished ceramic host. Perovskite structured nanomaterials had originated from CaTiO3. They are made up by the assembling of distinct materialistic components and follow the general configuration ABX3. Perovskite type metal oxide nanomaterial shows a wide range of ferroelectric, piezoelectric, and pyroelectric properties along with numerous optoelectrical effects. They get the facility to the various advanced technical applications due to the excellency in their properties. The photocatalytic activity may be one of the plausible and impulsive applications of that very special type of materials. Most elements in the periodic table are able to take part in designing the perovskite-type materials. Perovskite structured nanoparticles (NPs) are applying rapidly for global development because of their higher responsiveness and degree of function, large surface area, size-dependent properties etc and unfold the new possibilities in the field of nanotechnology.

EXPERIMENTAL STUDY OF THE EFFECT OF THE WAKE GENERATED BY OSCILLATING GURNEY FLAP

The study of the turbulent near wake of an airfoil provided with flow control devices shows the flow configuration in such conditions and the starting vortices mechanism, while, the far wake offers information about the general performance of the model. The objective of the present work is to study the develop of the fluid-dynamic structures found in the NACA 4412 airfoil wake, as well as the development of the same structures when flow con-trol techniques are applied by means of a oscillating Gurney Flap place in the lower surface of the wing model, close to the trailing edge. Tests were per-formed at a given Reynolds numbers and the flow control system was set at different frequencies. In order to study the effect of the control mechanism on the wake, hot wire anemometry techniques were used. Two components of the velocity vector were measured - longitudinal and vertical - by means of a vertical array of three sensors acquiring simulta-neously. The intention is to quantify the flow general configuration at the airfoil wake for different test conditions. The velocity vectors will be analyzed, together with the turbulence intensity and integral scales.

DIAGNOSTICS OF DICHOTOMY TEETH IN ORTHODONTIC RELAPSE

Aim: increasing the effectiveness of diagnosis and further orthodontic-surgical treatment of various clinical forms of hyperdontia (supernumerary teeth) and preventing recurrence with the use of cone-ray computer tomography data in orthodontic practice. Materials and methods. The clinical case of patient (born in 2004) treatment is presented, with severe hyperdontia and retention of teeth that had little effect on the formation of the general configuration of occlusion. The patient's examination and treatment was carried out with the assistance of clinical, anthropometric and radiological data. The clinical method was to examine the patient and formulate a plan for further orthodontic therapy. The radiological method consisted of data analysis of cefalometry by Bjork, Steiner using a computer program and conducting a survey using a cone-ray computer tomography, followed by the use of these data in diagnosis and orthodontic treatment. Results. Following the clinical and radiological methods of examination and subsequent orthodontic surgery, the corresponding end results were obtained: 1. The localization and topography of supernumerary teeth as the causes of relapse of pathology with the help of data obtained with the help of CBCT. 2. Radiographic picture reflected on the sagital and axial re-formats of tomograms for the diagnosis of supernumerary teeth, is more informative than diagnostics by standard diagnostic protocols. 3. After analysis of the study data, a more meaningful protocol of surgical intervention is prescribed. 4. Implementation of the results of modern diagnostics significantly influenced on the final result of orthodontic treatment. Conclusions. Thus, in the process of corresponding work installed: – the availability of computer tomography data is crucial for objective and qualitative diagnosis and treatment of hypertension. – the general level of diagnostics during the intervention is significantly increased.