Search results for "often"
showing 10 items of 88 documents
Effect of additives on the structural organization of asphaltene aggregates in bitumen
2019
Abstract Bitumens are composite materials whose complex organization hinders the rational understanding of their relationships between composition, structure and performances. So, research attempting to shed more light in this field is required. In this work Wide Angle X ray Scattering (WAXS) has been used to explore the influence of six opportunely chosen additives on the bitumen structure with the aim to ultimately correlate the findings with the bitumen performances. Diagnostic fingerprints have been observed in the WAXS profile: asphaltenes form stuck of about 18 A and constituted by about 6 asphaltene units on average. Such stucks are, in turn, organized at higher levels of complexity …
Investigation of a tunnel pasteurizer for “Nocellara del Belice” table olives processed according to the “Castelvetrano method”
2014
The influence of pasteurization temperature and time of treatment on the flesh firmness and the evolution of microbial communities was studied for table olives Cv. Nocellara del Belice, packed in glass jars and processed with a tunnel pasteurizer. The experiment was first carried out on the laboratory level in order to select the optimal combination of pasteurization time/temperature so as to obtain the proper balance between the consistency of the pulp and the microbiological quality of the final product. Pasteurization at industrial scale was then carried out in a tunnel pasteurizer applying the treatment at 75 °C for 8 min in the thermal center of the jars. Besides flesh firmness and mic…
CH of masonry materials via meshless meso-modeling
2014
In the present study a multi-scale computational strategy for the analysis of masonry structures is presented. The structural macroscopic behaviour is obtained making use of the Computational Homogenization (CH) technique based on the solution of the boundary value problem (BVP) of a detailed Unit Cell (UC) chosen at the meso-scale and representative of the heterogeneous material. The smallest UC is composed by a brick and half of its surrounding joints, the former assumed to behave elastically while the latter considered with an elastoplastic softening response. The governing equations at the macroscopic level are formulated in the framework of finite element method while the Meshless Meth…
Cultural institutions as agents of urban and community regeneration in the (post-)pandemic city. The case of the «Laboratorio Zen Insieme» in Palermo
2022
Although all cities in the world have been affected by the COVID-19 pandemic, its impacts on the territories, yet to be understood, are unevenly distributed, revealing extremely varied imbalances depending on the places. However, it is clear that the virus and its variants have aggravated pre-existing socio-spatial inequalities, creating new ones and bringing attention back to those implications between space, planning, public health and citizenship that are at the origins of contemporary urbanism. In a reference framework in which the crisis is globalized but unequal and in the absence of a welfare system capable of responding to the urgencies of the most marginalized social contexts and g…
Half-width plots, a simple tool to predict peak shape, reveal column kinetics and characterise chromatographic columns in liquid chromatography: Stat…
2013
Peak profiles in chromatography are characterised by their height, position, width and asymmetry; the two latter depend on the values of the left and right peak half-widths. Simple correlations have been found between the peak half-widths and the retention times. The representation of such correlations has been called half-width plots. For isocratic elution, the plots are parabolic, although often, the parabolas can be approximated to straight-lines. The plots can be obtained with the half-widths/retention time data for a set of solutes experiencing the same kinetics, eluted with a mobile phase at fixed or varying composition. When the analysed solutes experience different resistance to mas…
Broadband dielectric spectroscopy of PbMg1/3Nb2/3O3–PbSc1/2Nb1/2O3 ceramics
2010
Abstract Broadband dielectric spectroscopy results of various ordered and disordered (1 − x)Pb(Mg1/3Nb2/3)O3–(x)Pb(Sc1/2Nb1/2)O3 (PMN–PSN) ceramics are investigated in the temperature range from 80 K to 300 K and frequency range from 20 Hz to 2 THz. Dielectric dispersion is very broad and in the ferroelectrics case (x = 1, 0.95) consists of two parts: low-frequency part caused by ferroelectric domains and higher frequency part caused by soft mode. The relaxational soft mode exhibits pronounced softening close to phase transition temperature, as it is typical for order–disorder phase transitions. By substituting Sc3+ by Mg2+ in PMN–PSN ceramics relaxation slows down, and for relaxors (x = 0.…
Comment on “Molybdenum sound velocity and shear modulus softening under shock compression”
2015
In this Comment we discuss recent results presented by Nguyen et al. on shock compressed molybdenum up to 438 GPa [Phys. Rev. B 89, 174109 (2014)]. The aim of Nguyen's article is to show that there is no phase transition near 210 GPa. We propose instead an interpretation of their data that this material shows the onset of partial melting along the Hugoniot at $240(20)\phantom{\rule{0.28em}{0ex}}\mathrm{GPa}$, which is evident from abrupt changes in the pressure dependence of the shear modulus. This interpretation may solve the significant controversy in the melting slopes derived from shock and static experiments.
Improving on numerical simulations of nonlinear CMB anisotropies
2015
An Adaptative-Particle-Particle-Particle-Mesh code (HYDRA) plus a ray-tracing procedure was used in [1] to perform an exhaustive analysis of the weak lensing anisotropy. Other nonlinear Cosmic Microwave Background anisotropies, such as the Rees-Sciamaand the Sunyaev-Zel.dovicheffects are also being studied by using the same tools. Here we present some advances in our study of these nonlinear anisotropies. The primary advance is due to the use of better simulations with greater particle densities and appropriate softening, although other parameters have also been adjusted to get better estimates. Thus, we improve on a previous paper [2] where the Rees-Sciamaeffect was studied with Particle-M…
Softening Transitions with Quenched 2D Gravity
1996
We perform extensive Monte Carlo simulations of the 10-state Potts model on quenched two-dimensional $\Phi^3$ gravity graphs to study the effect of quenched connectivity disorder on the phase transition, which is strongly first order on regular lattices. The numerical data provides strong evidence that, due to the quenched randomness, the discontinuous first-order phase transition of the pure model is softened to a continuous transition.
Local softening of information geometric indicators of chaos in statistical modeling in the presence of quantum-like considerations
2013
In a previous paper (C. Cafaro et al., 2012), we compared an uncorrelated 3D Gaussian statistical model to an uncorrelated 2D Gaussian statistical model obtained from the former model by introducing a constraint that resembles the quantum mechanical canonical minimum uncertainty relation. Analysis was completed by way of the information geometry and the entropic dynamics of each system. This analysis revealed that the chaoticity of the 2D Gaussian statistical model, quantified by means of the Information Geometric Entropy (IGE), is softened or weakened with respect to the chaoticity of the 3D Gaussian statistical model due to the accessibility of more information. In this companion work, we…