Dissipative Charged Fluid in a Magnetic Field

We study the collective excitations in a dissipative charged fluid at zero chemical potential when an external magnetic field is present. While in the absence of magnetic field, four collective excitations appear in the fluid, we find five hydrodynamic modes in presence of magnetic field. This implies that the magnetic field splits the degeneracy between the transverse shear modes. Using linear response theory, we then compute the retarded response functions. In particular, it turns out that the correlation between charge and the energy fluctuations will no longer vanish, even at zero chemical potential. By use of the response functions, we also derive the relevant Kubo formulas for the transport coefficients.Comment: 6 page

Magneto-Transport in a Chiral Fluid from Kinetic Theory

We argue that in order to study the magneto-transport in a relativistic Weyl fluid, it is needed to take into account the associated quantum corrections, namely the side-jump effect, at least to second order. To this end, we impose Lorentz invariance to a system of free Weyl fermions in the presence of the magnetic field and find the second order correction to the energy dispersion. By developing a scheme to compute the integrals in the phase space, we show that the mentioned correction has non-trivial effects on the thermodynamics of the system. Specifically, we predict the form of the negative magnetoresistance in the system from the enthalpy density in equilibrium. Then in analogy with Weyl semimetal, in the framework of the chiral kinetic theory and under the relaxation time approximation, we explicitly compute the magneto-conductivities, at low temperature limit ($T\ll \mu$). We show that the conductivities obey the set of Ward identities which follow from the generating functional including the Chern-Simons part.Comment: 39 pages, 1 figure, 1 table, v2: journal version; references adde

COMPARISON OF VARIOUS MEASUREMENT TECHNIQUES FOR CHARACTERIZING THE HYDRODYNAMICS OF GAS-SOLID FLUIDIZED BEDS

There are various techniques to characterize the hydrodynamic of fluidized beds. Nowadays, sensor development is widely used to determine the hydrodynamic state of a fluidized bed to improve control and safety of the operation of such reactors. The objective of this study was to compare the advantages and disadvantages of the intrusive and novel non-intrusive techniques. The measurement techniques investigated in this work were vibration of the bed, acoustic emission and pressure. Extensive measurements were carried out at different superficial gas velocities with different particle sizes. Vibration and acoustic emissions were recorded at 25 KHz for 30 s using accelerometer and microphone, respectively. Pressure fluctuation signals were also collected at a sampling frequency of 400 Hz. These measurements were used for investigating the changes in the flow structure, specifically the flow regime transitions. The recorded signals were processed using wavelet analysis and statistical tools. It was shown that the variation of standard deviation, skewness and kurtosis of vibration signals against superficial gas velocity of the bed obey the same trend for different techniques. Results indicated that analyzing the vibration and acoustic signals can be considered as effective non intrusive techniques to characterize the hydrodynamics of gas-solid fluidized beds and in some cases they show better prediction of the hydrodynamic parameters

Hydrodynamic excitations in hot QCD plasma

We study the long wavelength excitations in rotating QCD fluid in the presence of an external magnetic field at finite vector and axial charge densities. We consider the fluctuations of vector and axial charge currents coupled to energy and momentum fluctuations and compute the SO(3) covariant dispersion relations of the six corresponding hydrodynamic modes. Among them, there are always two scalar chiralmagnetic- vortical-heat (CMVH) waves; in the absence of a magnetic field (vorticity) these waves reduce to chiral-vortical-heat (CVH) [chiral-magnetic-heat (CMH)] waves. While CMVH waves are a mixture of CMH and CVH waves, they have generally different velocities compared to the sum of velocities of the latter waves. The other four modes, which are made out of scalar-vector fluctuations, are mixed soundAlfven waves. We show that when the magnetic field is parallel with the vorticity, these four modes are the two ordinary sound modes together with two chiral Alfven waves propagating along the common direction of the magnetic field and vorticity

The effect of aminoguanidine on sperm motility and mitochondrial membrane potential in varicocelized rats

Objective(s): Increased levels of nitric oxide (NO) in the testicular veins of people suffering from varicocele have already been reported. However, the role of NO-synthase (NOS) isozymes and their inhibitors have not been extensively studied. We aimed to evaluate the inhibitory effects of aminoguanidine (AG), on sperm motility, vitality, and mitochondrial membrane potential (MMP) in varicocelized rats. Materials and Methods: Twenty fore male Wister rats were divided into control, sham, varicocele, and treatment groups. Varicocele and treatment groups underwent partial ligation of left renal vein. Rats in the sham group underwent the same procedures as the varicocele group with the exception of vein ligation. 10 weeks after varicocele induction, sperm parameters were evaluated in all groups. The treatment group received 50 mg/kg AG injection daily for 10 weeks after which they were sacrificed prior to assessment of the parameters. Sperm viability and MMP were assessed by flow cytometry using propidium iodide (PI) and rhodamine 123 (Rh123), respectively. Results: The results of this study show a decrease in sperm viability, motility and MMP in the varicocele group compared with the other groups. After AG injection, we observed that all the parameters were significantly enhanced in the treatment group compared with the other groups. Rh123 staining revealed a positive relation between MMP and sperm motility, whereas PI staining showed a positive relation between sperm motility and viability. Conclusion: The findings of our study show that AG improves sperm motility and MMP, and thus, might be useful in the management of varicocele-related infertility. © 2016, Mashhad University of Medical Sciences. All rights reserved