Stability Analysis for Complex Rotational Flow

Based on the earlier developed mathematical model of the complex flow due to the double rotations in two perpendicular directions, the stability analysis is performed in the paper. The Navier-Stokes equations are derived in the coordinate system rotating around the two perpendicular different axes, the vertical one of them is arranged on some distance from the other axis of rotation, the horizontal axis is directed along the tangential line to the circle of the vertical rotation. The two centrifugal and Coriolis forces create the unique features in high oscillating flow, with localities of the stretched liquid, due to their action varying by the circumferential cylindrical coordinate in the channel flow. Stability analysis for the complex rotational flow under double rotations creating strongly varying mass forces and stretching of the liquid is considered at first

Concrete Silos: Failures, Design Issues and Repair/Strengthening Methods

Current silo analysis and design methods developed from Janssen’s theory focus mainly on the flow of the granules inside the silo by assuming that the overall silo structure is infinitely rigid. A silo structure during discharge is technically a time varying mass dynamic problem, where the properties of the overall silo structure and the discharge rate and material properties also contribute to the development of the load. The physics of a silo system requires equilibrium between the granules inside the silo, the silo structure as a whole and the surrounding air. The established scientific principles and experimental data require fulfilling such equilibrium to accurately predict the dynamic loads during discharge. This correspondence explains how the equilibrium between the granules inside the silo, the silo structure as a whole and the surrounding air can be achieved to better predict and control the dynamic loads generated by the silo discharge process.

Quantum motion, coherent states and geometric phase of a generalized damped pendulum

In this work, we analyze the quantum dynamics of a generalized pendulum with a time-varying mass increasing exponentially and constant gravitation. By using Lewis–Riesenfeld invariant approach and Fock states, we solve the time-dependent Schrödinger equation for this system and write its solutions in terms of solutions of the Milne–Pinney equation. We also construct coherent states for the quantized pendulum and use both Fock and coherent states to investigate some important physical proprieties of the quantized pendulum such as eigenvalues of the angular displacement and momentum, their quantum variances as well as the respective uncertainty principle. Finally, we derive the geometric, dynamical and Berry phases for the time-dependent generalized pendulum.

Hazelnut products traceability through Isotope Ratio Mass Spectrometry approach

<p>The geographical origin of hazelnuts products is nowadays a relevant aspect of high-quality food characterization. Isotope Ratio Mass Spectrometry (IRMS) could play a key role in origin discrimination. The present study aims to assess the geographical provenience of Italian roasted hazelnuts and paste of hazelnuts, by analysing relative isotopic ratios of carbon, nitrogen, and oxygen, through Elemental Analyzer – and Thermal Conversion – Isotope Ratio Mass Spectrometry. Method development is performed by evaluating test samples repeatability, considering 15 replicates measurements on the same day, reproducibility, considering 30 replicates measurements on two different days, and robustness, considering 30 replicates measurements, varying mass parameter. Preliminary outcomes highlight reproducible and robust results, having acceptable standard deviation values (from 0.07 to 0.3). One-way ANOVA test demonstrates a significant statistical difference between Italian and Georgian hazelnut test samples (ca. 1 δ of difference). A Design of Experiment, for training and validation sets building, is prepared, taking into account factors as harvesting year, variety, processing, and percentage of the peel. A total of n=30 processed hazelnuts lots, from Italy, Turkey, Georgia, and Azerbaijan, are going to be analysed for origin evaluation. Despite further analysis are still in progress, this strategy could potentially be the election method for a lot of food chain traceability since food isotopic abundances reflect ground and climate-related features, typical of precise locations. Moreover, this approach consists of limited or even inexistent sample preparation and provides for high sensitivity.</p>