D. V. S. J. Prasanna kumar and Dr. A.V.Krishna Prasad
The geomagnetic data plays a important role in understanding the evolutionary process of Earth’s magnetic field, as it provides necessary information for near-surface exploration, unexploded explosive ordnance detection, and so on. To reconstruct the geomagnetic data, this project presents a geomagnetic data reconstruction method based on machine learning techniques. The traditional linear approaches are prone to time inefficiency and involves high labor cost, while the proposed approach has a significant improvement. In this project, three classic machine learning models, support vector machine, random forests, and gradient boosting were built. And, a deep learning algorithm, recurrent neural network, was explored to further improve the performance. The proposed learning methods were used to specify a continuous regression hyperplane from a training data. The specified regression hyperplane is a mapping of the relation between the missing data and the surrounding intact data. Then, the trained method, were used to build the missing geomagnetic data for validation, and they can be used for reconstructing further collected new field data. Finally, numerical experiments were derived. The results shows that the performance of our proposed methods was more accurate in comparison with the traditional linear learning method, as the reconstruction accuracy was increased by approximately 10%∼20%.
With the increasing popularity of extreme conditioning programmes, athletes and patients are searching for new, engaging, high-intensity, total-body workouts. The sport of Hooverball is increasingly used as a workout. First devised in the USA in 1929 to keep President Hoover physically fit, Hooverball has experienced increasing popularity in the past 15 years. The game is scored like tennis and played like volleyball, with players throwing and catching a heavy medicine ball over a volleyball net. Players use complex, multi-joint, explosive movements, featuring torsion, flexion and extension to absorb the forces involved. This paper reports a case of a Hooverball player who presented with a knee injury. The paper also reviews the origins of the sport, and its increase in popularity related to the increasing prominence of extreme conditioning programmes. A literature review, and common Hooverball-related injuries, are presented. Clinical recommendations are set out for patient safety, injury prevention and game coverage, including a prehabilitation strategy for players prior to engaging in this revived and growing sport. LAY ABSTRACT With the increasing popularity of “extreme conditioning” exercise programmes, players and patients are searching for new and engaging high-intensity, total-body workouts. This report examines the case of Hooverball, a revived workout. First invented in the USA in 1929 to keep President Hoover physically fit, Hooverball has experienced an increase in popularity over the past 15 years. The game is scored like tennis and played like volleyball, but instead of striking a lightweight ball, players throw and catch a heavy medicine ball over a volleyball net. In order to absorb the impact and return a medicine ball over the net, players use complex, multi-joint, explosive movements. This paper reviews the origins of the sport and its increase in popularity related to the increasing prominence of extreme conditioning programmes. Clinical recommendations are set out for patient safety, injury prevention and game coverage, including a prehabilitation strategy for players prior to engaging in this revived and growing sport.
Derek K. Schwanz, A. Villa, M. Balasubramanian
et al.
We report on a novel approach to synthesize cubic-phase fast ionic conducting garnet-type solid state electrolytes based on Bi doped Li7La3Zr2O12 (LLZO). Bi aliovalent substitution into LLZO utilizing the Pechini processing method is successfully employed to synthesize Li7-xLa3Zr2-xBixO12 compounds. Ionic conductivities up to 2.0 x 10-4 S/cm are achieved in structures not fully densified. Cubic phase Li6La3ZrBiO12 powders are generated in the temperature range from 650 °C to 900 °C in air. In contrast, in the absence of Bi and under identical synthesis conditions, the cubic garnet phase of Li7La3Zr2O12 is not formed below 700 °C while a transformation to the tetragonal phase is observed at 900 °C for the un-doped compound. The critical role of Bi in lowering the formation temperature of the garnet cubic phase and the improvements in ionic conductivity is investigated in this work through microstructural studies and AC impedance measurements. We ascribe the effect of Bi doping in achieving these remarkable improvements to significant enhancements at lower temperatures in the kinetics of the solid-state reaction resulting in explosive grain growth and densification of the garnet. Moreover, XAS is utilized to identify the specific atomic site where Bi is incorporated in the LLZO garnet crystalline structure.
Abstract Metal nitrates are widely used as oxidizers and in light-producing compositions in both civilian and military explosive applications. In this work we have explored the isomorphous divalent metal nitrates M(NO3)2 (M = Sr, Ba) by using dispersion-corrected density functional theory methods. The equilibrium results calculated with Grimme (G06) (for Sr(NO3)2) and Ortmann-Bechstedt-Schmidt (for Ba(NO3)2) functionals reproduced the experimental lattice parameters. We present the effect of cations on the lattice dynamical properties conjointly with their elastic and thermodynamic properties. The linear response approach within density functional perturbation theory was used to calculate the zone-center vibrational frequencies, phonon dispersion relation, and phonon density of states. The infrared spectrum of these compounds in their fundamental state is studied in the whole 0–1500 cm−1 range, and is critically analyzed in the light of previous experimental investigations. We observed that most of the high-frequency vibrational modes emerge because of the NO3 group. The calculated phonon dispersion curves do not show any vibrational anomaly, confirming the dynamical stability of the compounds in the cubic ( P a 3 ¯ ) phase. The calculated shear anisotropic factors of 1.8 and 2.1 for Sr(NO3)2 and Ba(NO3)2, respectively, indicate that both crystals studied possess considerable mechanical anisotropy. As the thermal behavior of these materials could play a key role in the growth of sustainable smoke compositions, thermodynamic properties such as the entropy, Debye temperature, heat capacity, and enthalpy were calculated. The results reveal that the compounds are thermodynamically stable up to 750 K. This work demonstrates that Sr(NO)2 and Ba(NO3)2 can be reliably used in pyrotechnics as they possess considerable thermal conductivity, leading to a high burn rate. The results presented in this work could open a way to understand the lattice dynamics of materials of this type and could provide necessary input from the pyrotechnic applicability point of view, which would help experimental researchers in the future.
We present a formalization of a so-called paraconsistent logic that avoids the catastrophic explosiveness of inconsistency in classical logic. The paraconsistent logic has a countably infinite number of non-classical truth values. We show how to use the proof assistant Isabelle to formally prove theorems in the logic as well as meta-theorems about the logic. In particular, we formalize a meta-theorem that allows us to reduce the infinite number of truth values to a finite number of truth values, for a given formula, and we use this result in a formalization of a small case study.
Explosive evaporation of a superheated liquid is a relevant hazard in the process industry. A vessel rupture during storage, transport or handling may lead to devastating blast effects. In order to assess the risk associated with this hazard or to design protective measures, an accurate prediction model for the blast generated after vessel rupture is needed. For this reason a fundamental understanding of the effects of a boiling liquid expanding vapor explosion (BLEVE) is essential. In this paper, we report on a number of well-defined BLEVE experiments with 40-l liquid CO2 bottles. The existing inertia-limited BLEVE model has been validated by its application to these experiments. Good qualitative agreement between model and experiment was found, while quantitatively the results provide a safe estimate. Possible model improvements taking into account the finite rate of evaporation are described. These comprise phenomena such as bubble nucleation and growth rate, and the two-phase flow regime. Suggestions for improved experiments are given as well.