On the location of poles for the Ablowitz-Segur family of solutions to the second Painlev\'e equation

Using a simple operator-norm estimate we show that the solution to the second Painlev\'e equation within the Ablowitz-Segur family is pole-free in a well defined region of the complex plane of the independent variable. The result is illustrated with several numerical examples.Comment: 8 pages, to appear in Nonlinearit

Y-System and Deformed Thermodynamic Bethe Ansatz

We introduce a new tool, the Deformed TBA (Deformed Thermodynamic Bethe Ansatz), to analyze the monodromy problem of the cubic oscillator. The Deformed TBA is a system of five coupled nonlinear integral equations, which in a particular case reduces to the Zamolodchikov TBA equation for the 3-state Potts model. Our method generalizes the Dorey-Tateo analysis of the (monomial) cubic oscillator. We introduce a Y-system corresponding to the Deformed TBA and give it an elegant geometric interpretation.Comment: 12 pages. Minor corrections in Section

Current noise in high Tc granular superconductors under non-stationary conditions of current and magnetic field

We present a set of experimental results concerning the power spectrum of current noise, detected on a granular high Tc superconductor submitted either to a slowly varying magnetic field or to a varying current intensity. Experiments were performed on a YBCO specimen suitably treated in order to weaken the weak links without affecting the oxygen content of grains. The weakening of the intergrain region allowed the use of very small magnetic fields and currents to induce the resistive transition of the specimen and to observe current noise. The induced noise is of the 1/f^2 type and will be interpreted in terms of two different models. One of the model is based on the enhancement of the noise due to the clustering of the resistive transition of the weak links, produced by correlation effects related to the strong nonlinearity of their Josephson type I-V characteristics. This model has been the object of a computer simulation based on a 3D-network of Josephson-like elements and seems suitable to explain the noise produced by current variation. The second model explains the excess noise as produced by discontinuous penetration of the magnetic flux inside the intergrain region. This discontinuity is related to the field screening effect of rings made of several superconducting weak links connecting different grains, which are alternatively broken and restored by the current induced during flux variation, and seems suitable to explain the larger noise produced by a varying magnetic field.Comment: 7 pages, 4 figures, conference contribution to "Fluctuations and Noise", Santa Fe, New Mexico 1-4 June 200

Carbonation and self-healing in concrete: Kinetic Monte Carlo simulations of mineralization

Industrial applications of carbonation such as self-healing and carbon capture and storage have been limited, due to a lack of reliable predictive models linking the chemistry of carbonation at the molecular scale to microstructure development and macroscopic properties. This work proposes a coarse-grained Kinetic Monte Carlo (KMC) approach to simulate microstructural evolution of a model cement paste during carbonation, along with evolution of pore solution chemistry and saturation indexes of solid species involved. The simulations predict the effective rate constants for Ca(OH)2 dissolution and CaCO3 precipitation as kCa(OH)2 = 2.20 × 10−5 kg/m3/s and kCaCO3 = 4.24 × 10−6 kg/m3/s. These values are directly fed to a macroscale reactive transport model to predict carbonate penetration depth. The rate constants from the molecular scale are used in a boundary nucleation and growth model to predict self-healing of cracks. Subsequently these results are compared with experimental data, and provide good agreement. This proposed multiscale approach can help understand and manage the carbonation of both traditional and new concretes, supporting applications in residual lifetime assessment, carbon capture, and self-healing

In situ and in vitro nutritional evaluation of rumen-protected lipids

Rumen-protected lipids are a class of products which is increasingly used in ruminant nutrition even if the results are not homogeneous. The different results may be due to different analytical or technological characteristics. Aim of this work was therefore to compare the in situ rumen behaviour of different soaps as well as their in vitro intestinal digestibility

Advances in biomimetic collagen mineralisation and future approaches to bone tissue engineering

With an ageing world population and ~20% of adults in Europe being affected by bone diseases, there is an urgent need to develop advanced regenerative approaches and biomaterials capable to facilitate tissue regeneration while providing an adequate microenvironment for cells to thrive. As the main components of bone are collagen and apatite mineral, scientists in the tissue engineering field have attempted in combining these materials by using different biomimetic approaches to favour bone repair. Still, an ideal bone analogue capable of mimicking the distinct properties (i.e., mechanical properties, degradation rate, porosity, etc.) of cancellous bone is to be developed. This review seeks to sum up the current understanding of bone tissue mineralisation and structure while providing a critical outlook on the existing biomimetic strategies of mineralising collagen for bone tissue engineering applications, highlighting where gaps in knowledge exist

Painleve I, Coverings of the Sphere and Belyi Functions

The theory of poles of solutions of Painleve-I is equivalent to the Nevanlinna problem of constructing a meromorphic function ramified over five points - counting multiplicities - and without critical points. We construct such meromorphic functions as limit of rational ones. In the case of the tritronquee solution these rational functions are Belyi functions.Comment: 33 pages, many figures. Version 2: minor corrections and minor changes in the bibliograph

Raw and extruded pea (Pisum sativum) and lupin (Lupinus albus var. Multitalia) seeds as protein sources in weaned piglets' diets: effect on growth rate and blood parameters

The 42 days trial was carried out using 140 piglets weaned at 28 days of age. The piglets were allocated according to weight and sex to the 5 dietary treatments with 7 replicates for each treatments (4 pens x 4 castrated males and 3 pens x 4 females). The piglets were fed according to the following experimental design: 1) control diet (CTR) with soybean meal (SBM) 44% c.p. as protein source; 2) CRT diets with 200 g/kg of raw pea (Pisum sativum) (RP); 3) CTR diet with 200 g/kg extruded pea (EP); 4) CRT diet with 170 g/kg raw lupin (Lupinus albusvar. Multitalia) (RL); 5) CTR diet with 170 g/kg of extruded lupin (EL). During the trial, animals were weighed at 0 - 21 and 42 days from the start of the trial. Feed intake was monitored and feed conversion ratio was calculated for the periods 0-21 d and 22-42 d. At the end of the trial, blood samples were taken for 14 animals for each dietary treatment (2 animals per replicate) and analysed for total protein, urea and liver activity (ALT, AST and ALP parameters). Average daily weight gain and feed intake did not differ according to dietary treatments whereas during the total experimental period (0-42 d), feed conversion ratio was higher for EP vsCTR diet (2.35 vs2.09, respectively; P <0.05). The growth rate for diets with extruded protein sources compared with diets containing the raw ingredients did not differ. Feed conversion ratio for the RP was numerically high- er than for the EP (2.35 vs2.16 and 2.76 vs2.32, respectively during 22-42 d and 0-42 d periods). Blood parameters did not show significant difference among dietary treatments except for higher total protein for CTR diet vsRL diet, EL and RP (67.3 vs62.2, 62.8 and 63.6 g/l, respectively; P<0.05) and urea that resulted the highest with CTR diet vsRL and RL (4.7 vs3.7 and 3.8 mmol/l respectively; P<0.05)

Along-the-net reconstruction of hydropower potential with consideration of anthropic alterations

Even in regions with mature hydropower development, requirements for stable renewable power sources suggest revision of plans of exploitation of water resources, while taking care of the environmental regulations. Mean Annual Flow (MAF) is a key parameter when trying to represent water availability for hydropower purposes. MAF is usually determined in ungauged basins by means of regional statistical analysis. For this study a regional estimation method consistent along-the-river network has been developed for MAF estimation; the method uses a multi-regressive approach based on geomorphoclimatic descriptors, and it is applied on 100 gauged basins located in NW Italy. The method has been designed to keep the estimates of mean annual flow congruent at the confluences, by considering only raster-summable explanatory variables. Also, the influence of human alterations in the regional analysis of MAF has been studied: impact due to the presence of existing hydropower plants has been taken into account, restoring the "natural" value of runoff through analytical corrections. To exemplify the representation of the assessment of residual hydropower potential, the model has been applied extensively to two specific mountain watersheds by mapping the estimated mean flow for the basins draining into each pixel of a the DEM-derived river network. Spatial algorithms were developed using the OpenSource Software GRASS GIS and PostgreSQL/PostGIS. Spatial representation of the hydropower potential was obtained using different mean flow vs hydraulic-head relations for each pixel. Final potential indices have been represented and mapped through the Google Earth platform, providing a complete and interactive picture of the available potential, useful for planning and regulation purpose