Stage-Discharge Prediction for Converging Compound Channels with Narrow Floodplains

Momentum transfer between a main channel and side floodplains tends to increase the floodplain shear and decrease the main channel shear. The increase and decrease in shear are greatly influenced when a compound channel has nonprismatic floodplains. In converging compound channels, water flow on the floodplain crosses over water flow in the main channel, resulting in increased interactions and momentum exchanges. An experimental analysis concerning the distribution of shear stress in the main channel and the floodplain for both prismatic and nonprismatic compound channels under different overbank flow conditions are performed. New equations are developed for predicting boundary shear stress distribution for a compound channel with the nonprismatic flood plain. Using these expressions the stage-discharge relationships for both prismatic and nonprismatic compound channels of lower width ratios are successfully estimated. The efficiency of the models is verified by applying natural river data sets

Magnetic properties of triangular lattice antiferromagnets Ba3RB9O18 (R = Yb, Er)

Frustration, spin correlations and interplay between competing degrees of freedom are some of the key ingredients that underlie exotic states with fractional excitations in quantum materials. Rare-earth based two dimensional magnetic lattice wherein crystal electric field, spin-orbit coupling, anisotropy and electron correlation between rare-earth moments offer a new paradigm in this context. Herein, we present crystal structure, magnetic susceptibility and specific heat accompanied by crystal electric field calculations on the polycrystalline sample of Ba3RB9O18 (R = Yb, Er) in which R3+ ions form a perfect triangular lattice without anti-site disorder. The localized R3+ spins show neither long-range order nor spin-glass state down to 1.9 K in Ba3RB9O18. Magnetization data reveal a pseudospin Jeff = 1/2 ( Yb3+) in the Kramers doublet state and a weak antiferromagnetic interaction between Jeff = 1/2 moments in the Yb variant. On the other hand, the effective moment {\mu}eff = 8.8 {\mu}B was obtained from the Curie-Weiss fit of the low-temperature susceptibility data of Er variant suggests the admixture of higher crystal electric field states with the ground state. The Curie-Weiss fit of low-temperature susceptibility data for Er system unveils the presence of a relatively strong antiferromagnetic interaction between Er3+ moments compared to its Yb3+ analog. Ba3ErB9O18 does not show long-range magnetic ordering down to 500 mK. Furthermore, our crystal electric field calculations based on magnetization data of Ba3ErB9O18 suggest the presence of a small gap between the ground and first excited Kramers doublets. The broad maximum around 4 K in magnetic specific heat in zero-field is attributed to the thermal population of the first CEF excited state in Ba3ErB9O18, which is consistent with our CEF calculations

Magnetism and field-induced effect in a spin-orbit entangled Jeff = 1/2 honeycomb lattice

The interplay between spin-orbit coupling, frustration-induced anisotropic magnetic interaction, and spin correlations can lead to novel states with exotic excitations in rare-earth-based quantum magnets. Herein, we present the crystal structure, magnetization, electron spin resonance (ESR), specific heat, and nuclear magnetic resonance (NMR) experiments on the polycrystalline samples of Ba9Yb2Si6O24 in which Yb3+ ions form a perfect honeycomb lattice without detectable anti-site disorder. Magnetization data reveal antiferromagnetically coupled spin-orbit entangled Jeff = 1/2 degrees of freedom of Yb3+ ions in the Kramers doublet state where the Curie-Weiss temperature is - 2.97 K, as obtained from the low-temperature magnetic susceptibility data. The ESR measurements reveal that the first excited Kramers doublet is 32.3(7) meV above the ground state. The specific heat results suggest the presence of an antiferromagnetic phase transition at 2.26 K. The long-range antiferromagnetic order is completely suppressed upon the application of magnetic field and a field-induced disordered state is observed in an applied magnetic field of 2.5 T, which is also confirmed by NMR measurements. Furthermore, the NMR spin-lattice relaxation rate reveals the presence of a field-induced gap that is attributed to the Zeeman splitting of Kramers doublet state in this quantum material. Our experiments suggest the presence of a phase transition and short-range spin correlations appearing well above the antiferromagnetic phase transition temperature and a field-induced disordered state in this spin-orbit entangled Jeff =1/2 rare-earth magnet on a honeycomb lattice

Dynamics of Logamediate and Intermediate Scenarios in the Dark Energy Filled Universe

We have considered a model of two component mixture i.e., mixture of Chaplygin gas and barotropic fluid with tachyonic field. In the case, when they have no interaction then both of them retain their own properties. Let us consider an energy flow between barotropic and tachyonic fluids. In both the cases we find the exact solutions for the tachyonic field and the tachyonic potential and show that the tachyonic potential follows the asymptotic behavior. We have considered an interaction between these two fluids by introducing a coupling term. Finally, we have considered a model of three component mixture i.e., mixture of tachyonic field, Chaplygin gas and barotropic fluid with or without interaction. The coupling functions decays with time indicating a strong energy flow at the initial period and weak stable interaction at later stage. To keep the observational support of recent acceleration we have considered two particular forms (i) Logamediate Scenario and (ii) Intermediate Scenario, of evolution of the Universe. We have examined the natures of the recent developed statefinder parameters and slow-roll parameters in both scenarios with and without interactions in whole evolution of the universe.Comment: 28 pages, 20 figure

An uncommon cause for a common fracture - Commentary

Aim: Mandibular angle fracture is one of the common fractures which a maxillofacial surgeon faces, which has a variable etiology. The aim of this commentary is to present a rare case of a mandibular angle fracture caused by heavy bite force and amplified by the wedging action of impacted mandibular third molar in a 29-year-old male patient. This is a first case report in the literature as per our knowledge, where a strong bite force caused a mandibular angle fracture, during heavy weight lifting in the gymnasium. Conclusion: The consequent fracture was reduced with an open reduction and internal fixation under local anaesthesia. An unusual case of a mandibular angle fracture with a very uncommon etiology of heavy bite force has been presented here with its management. Clinical Significance: This commentary discusses the relationship between the normal bite force, force required to fracture the mandible, and how a fracture of this kind can affect a person involved in non-contact sports

First report of Champsodon capensis Regan, 1908 (Champsodontidae) from East coast of India

The gaper Champsodon capensis Regan, 1908 is reported for the first time from the east coast of India on the basis of 3 specimens (55 – 72 mm standard length) collected from Deshpran fishing harbor, West Bengal. Identification of the species is confirmed by ventral scale patterns on chin, breast, and abdomen. Earlier, this species was reported only from Andaman-Nicobar waters of India and the present finding report further range extension of the species to the northern part of the Bay of Bengal. This paper provides a detailed description of the species along with the comparison with other Champsodon species

Experimental signatures of quantum and topological states in frustrated magnetism

Frustration in magnetic materials arising from competing exchange interactions can prevent the system from adopting long-range magnetic order and can instead lead to a diverse range of novel quantum and topological states with exotic quasiparticle excitations. Here, we review prominent examples of such emergent phenomena, including magnetically-disordered and extensively degenerate spin ices, which feature emergent magnetic monopole excitations, highly-entangled quantum spin liquids with fractional spinon excitations, topological order and emergent gauge fields, as well as complex particle-like topological spin textures known as skyrmions. We provide an overview of recent advances in the search for magnetically-disordered candidate materials on the three-dimensional pyrochlore lattice and two-dimensional triangular, kagome and honeycomb lattices, the latter with bond-dependent Kitaev interactions, and on lattices supporting topological magnetism. We highlight experimental signatures of these often elusive phenomena and single out the most suitable experimental techniques that can be used to detect them. Our review also aims at providing a comprehensive guide for designing and investigating novel frustrated magnetic materials, with the potential of addressing some important open questions in contemporary condensed matter physics

Numerical modeling of converging compound channel flow

This paper presents numerical analysis for prediction of depth-averaged velocity distribution of compound channels with converging flood plains. Firstly, a 3D Computational Fluid Dynamics model is used to establish the basic database under various working conditions. Numerical simulation in two phases is performed using the ANSYS-Fluent software. k-ω turbulence model is executed to solve the basic governing equations. The results have been compared with high-quality flume measurements obtained from different converging compound channels in order to investigate the numerical accuracy. Then Artificial Neural Network are trained based on the Back Propagation Neural Network technique for depth-averaged velocity prediction in different converging sections and these test results are compared with each other and with actual data. The study has focused on the ability of the software to correctly predict the complex flow phenomena that occur in channel flows

SR9009 administered for one day after myocardial ischemia-reperfusion prevents heart failure in mice by targeting the cardiac inflammasome

Reperfusion of patients after myocardial infarction (heart attack) triggers cardiac inflammation that leads to infarct expansion and heart failure (HF). We previously showed that the circadian mechanism is a critical regulator of reperfusion injury. However, whether pharmacological targeting using circadian medicine limits reperfusion injury and protects against HF is unknown. Here, we show that short-term targeting of the circadian driver REV-ERB with SR9009 benefits long-term cardiac repair post-myocardial ischemia reperfusion in mice. Gain and loss of function studies demonstrate specificity of targeting REV-ERB in mice. Treatment for just one day abates the cardiac NLRP3 inflammasome, decreasing immunocyte recruitment, and thereby allowing the vulnerable infarct to heal. Therapy is given in vivo, after reperfusion, and promotes efficient repair. This study presents downregulation of the cardiac inflammasome in fibroblasts as a cellular target of SR9009, inviting more targeted therapeutic investigations in the future