Effects of Orthogonal Rotating Electric Fields on Electrospinning Process

Electrospinning is a nanotechnology process whereby an external electric field is used to accelerate and stretch a charged polymer jet, so as to produce fibers with nanoscale diameters. In quest of a further reduction in the cross section of electrified jets hence of a better control on the morphology of the resulting electrospun fibers, we explore the effects of an external rotating electric field orthogonal to the jet direction. Through extensive particle simulations, it is shown that by a proper tuning of the electric field amplitude and frequency, a reduction of up to a $30 \%$ in the aforementioned radius can be obtained, thereby opening new perspectives in the design of future ultra-thin electrospun fibres. Applications can be envisaged in the fields of nanophotonic components as well as for designing new and improved filtration materials.Comment: 22 pages, 8 figure

Power cycling analysis of enameled aluminium winding wires connections pprepared with the use of SHARK-Al® type connectors

The article presents the research results of current cyclic thermal tests performed on enamelled aluminium wires connections, made with the use of a new type of Shark-Al quick-connectors. In particular, the main purpose of the conducted research was to analyse the effect of cyclic heating on the contact resistance change during the tests which allows to test the stability of the connections in simulated working conditions under current flow. Tests included a total of 300 thermal cycles, of which the first 200 were carried out to the 65 °C temperature measured in the connector at above the ambient temperature, and then additional 100 cycles were performed for the temperature of the connector at 140 °C (tolerance +5 °C). During the tests, the resistance of samples was monitored, which allowed to verify the correctness of performed connections

Power cycling analysis of enameled aluminium winding wires connections pprepared with the use of SHARK-Al® type connectors

The article presents the research results of current cyclic thermal tests performed on enamelled aluminium wires connections, made with the use of a new type of Shark-Al quick-connectors. In particular, the main purpose of the conducted research was to analyse the effect of cyclic heating on the contact resistance change during the tests which allows to test the stability of the connections in simulated working conditions under current flow. Tests included a total of 300 thermal cycles, of which the first 200 were carried out to the 65 °C temperature measured in the connector at above the ambient temperature, and then additional 100 cycles were performed for the temperature of the connector at 140 °C (tolerance +5 °C). During the tests, the resistance of samples was monitored, which allowed to verify the correctness of performed connections

Research on mechanical and electrical properties of enamel winding wires connections made with the use of SHARK-Al® technology

The results of the research that have been presented in this article include the analysis of basic exploitational properties of connections made with the use of new family of Shark-Al connectors, which are the first in the industry strictly dedicated for connecting the enamelled aluminium wires. In particular, the test results include the analysis of the contact resistance and tensile strength of connections prepared with the various types of connectors and various configurations of used enamelled wires. Results of this work enabled to verify the correctness of performed connecting process and also allowed to verify the connectors design

Research on mechanical and electrical properties of enamel winding wires connections made with the use of SHARK-Al® technology

The results of the research that have been presented in this article include the analysis of basic exploitational properties of connections made with the use of new family of Shark-Al connectors, which are the first in the industry strictly dedicated for connecting the enamelled aluminium wires. In particular, the test results include the analysis of the contact resistance and tensile strength of connections prepared with the various types of connectors and various configurations of used enamelled wires. Results of this work enabled to verify the correctness of performed connecting process and also allowed to verify the connectors design

Higher analogues of the discrete-time Toda equation and the quotient-difference algorithm

The discrete-time Toda equation arises as a universal equation for the relevant Hankel determinants associated with one-variable orthogonal polynomials through the mechanism of adjacency, which amounts to the inclusion of shifted weight functions in the orthogonality condition. In this paper we extend this mechanism to a new class of two-variable orthogonal polynomials where the variables are related via an elliptic curve. This leads to a `Higher order Analogue of the Discrete-time Toda' (HADT) equation for the associated Hankel determinants, together with its Lax pair, which is derived from the relevant recurrence relations for the orthogonal polynomials. In a similar way as the quotient-difference (QD) algorithm is related to the discrete-time Toda equation, a novel quotient-quotient-difference (QQD) scheme is presented for the HADT equation. We show that for both the HADT equation and the QQD scheme, there exists well-posed $s$-periodic initial value problems, for almost all \s\in\Z^2. From the Lax-pairs we furthermore derive invariants for corresponding reductions to dynamical mappings for some explicit examples.Comment: 38 page

Ecological regime shift preserved in the Anthropocene stratigraphic record

Palaeoecological data are unique historical archives that extend back far beyond the last several decades of ecological observations. However, the fossil record of continental shelves has been perceived as too coarse (with centennial-millennial resolution) and incomplete to detect processes occurring at yearly or decadal scales relevant to ecology and conservation. Here, we show that the youngest (Anthropocene) fossil record on the northern Adriatic continental shelf provides decadal-scale resolution that accurately documents an abrupt ecological change affecting benthic communities during the twentieth century. The magnitude and the duration of the twentieth century shift in body size of the bivalve Corbula gibba is unprecedented given that regional populations of this species were dominated by small-size classes throughout the Holocene. The shift coincided with compositional changes in benthic assemblages, driven by an increase from approximately 25% to approximately 70% in median per-assemblage abundance of C. gibba. This regime shift increase occurred preferentially at sites that experienced at least one hypoxic event per decade in the twentieth century. Larger size and higher abundance of C. gibba probably reflect ecological release as it coincides with an increase in the frequency of seasonal hypoxia that triggered mass mortality of competitors and predators. Higher frequency of hypoxic events is coupled with a decline in the depth of intense sediment mixing by burrowing benthic organisms from several decimetres to less than 20 cm, significantly improving the stratigraphic resolution of the Anthropocene fossil record and making it possible to detect sub-centennial ecological changes on continental shelves

Diffractive point sets with entropy

After a brief historical survey, the paper introduces the notion of entropic model sets (cut and project sets), and, more generally, the notion of diffractive point sets with entropy. Such sets may be thought of as generalizations of lattice gases. We show that taking the site occupation of a model set stochastically results, with probabilistic certainty, in well-defined diffractive properties augmented by a constant diffuse background. We discuss both the case of independent, but identically distributed (i.i.d.) random variables and that of independent, but different (i.e., site dependent) random variables. Several examples are shown.Comment: 25 pages; dedicated to Hans-Ude Nissen on the occasion of his 65th birthday; final version, some minor addition