Foliations on the tangent bundle of Finsler manifolds

Let M be a smooth manifold with Finsler metric F,and let T M be the slit tangent bundle of M with a generalized Riemannian metric G,which is induced by F.In this paper,we prove that (i) (M,F) is a Landsberg manifold if and only if the vertical foliation F V is totally geodesic in (T M,G);(ii) letting a:= a(τ) be a positive function of τ=F 2 and k,c be two positive numbers such that c=2 k(1+a),then (M,F) is of constant curvature k if and only if the restriction of G on the c-indicatrix bundle IM (c) is bundle-like for the horizontal Liouville foliation on IM (c),if and only if the horizontal Liouville vector field is a Killing vector field on (IM (c),G),if and only if the curvature-angular form Λ of (M,F) satisfies Λ=1-a 2/R on IM (c).     

Killing vector fields of horizontal Liouville type

On a slit tangent bundle endowed with a Riemannian metric of Sasaki–Finsler type, we introduce two vector fields of horizontal Liouville type and prove that these vector fields are Killing if and only if the base Finsler manifold is of positive constant curvature. In the special case of one of them, we show that if it is Killing vector field then the base manifold is Einstein–Finsler manifold.     

Optical interferometry method for the study of density variation in the nanosecond pulsed Nd:YAG laser interaction with aluminum

An interferometer-based technique has been used to determine the change in the refractive index induced by a Q-switched Nd–YAG laser (λ=532 nm and pulse duration 6 ns) on an aluminum target under atmospheric air pressure. The average density changes in front of the target irradiated by two laser pulse energy were observed for different focusing conditions. An Abel inversion technique is also presented for calculating three-dimensional density distributions in cylindrical coordinates.     

Higher Dimensional Spherically Symmetric Expanding Wormholes in Einstein’s Gravity

We present (n+1)-dimensional expanding structures in a cosmological background. Due to the expansion of spacetime the throat of wormholes enlarge with time. These solutions are examined in the Einstein’s framework. A general linear relation between diagonal elements of an anisotropic energy-momentum tensor is assumed and the spherically symmetric structures are obtained. Solutions include naked singularity and expanding wormholes in an open universe. The traversibility of wormhole solutions is explored and we find that they are basically traversable. Finally, we consider the corresponding energy-momentum tensor properties and specially take into account the standard energy conditions.     

Development of a new correlation to calculate permeability for flows with high Knudsen number

Flows with high Knudsen number play a prominent role in many engineering applications. The present study is an effort toward the simulation of flow with high Knudsen number using modified lattice Boltzmann method(LBM) through a porous medium in a channel. The effect of collision between molecules and solid walls, which is required to accurately simulate transition flow regime, is taken into account using a modified relaxation time. Slip velocity on the wall, which is another significant difficulty in simulating transition flow regime, is captured using the slip reflection boundary condition(SRBC). The geometry of porous medium is considered as in-line and staggered. The results are in good agreement with previous works. A new correlation is obtained between permeability, Knudsen number and porosity for flows in transition flow regimes.     

The Impacts of Different Biological Treatments on the Transformation of Explosives Waste Contaminated Sludge

The dinitrotoluene isomers 2,4 and 2,6-dinitrotoluene (DNT) represent highly toxic, mutagenic, and carcinogenic compounds used in explosive manufacturing and in commercial production of polyurethane foam. Bioremediation, the use of microbes to degrade residual DNT in industry wastewaters, represents a promising, low cost and environmentally friendly alternative technology to landfilling. In the present study, the effect of different bioremediation strategies on the degradation of DNT in a microcosm-based study was evaluated. Biostimulation of the indigenous microbial community with sulphur phosphate (2.3 g/kg sludge) enhanced DNT transformation (82% transformation, from 300 g/L at Day 0 to 55 g/L in week 6) compared to natural attenuation over the same period at 25 °C. The indigenous microbial activity was found to be capable of transforming the contaminant, with around 70% transformation of DNT occurring over the microcosm study. 16S rDNA sequence analysis revealed that while the original bacterial community was dominated by Gammaproteobacteria (30%), the addition of sulphur phosphate significantly increased the abundance of Betaproteobacteria by the end of the biostimulation treatment, with the bacterial community dominated by Burkholderia (46%) followed by Rhodanobacter, Acidovorax and Pseudomonas. In summary, the results suggest biostimulation as a treatment choice for the remediation of dinitrotoluenes and explosives waste.     

Pyrrolizidine Alkaloids-Free Extract from the Cell Culture of Lithospermum officinale with High Antioxidant Capacity

The benefits of Lithospermum officinale has encouraged people to continue using its extract (CAS 90063-58-4) in both medicinal and cosmetic industries despite the fact that chemical analysis confirms the presence of pyrrolizidine alkaloids (PAs) in the extract. While the cultivation of L. officinale takes, at least, 2 years to produce usable crops, its callus culture proliferated 8.3 times with 4.9-fold biomass in less than 30 days under the applied conditions in this study. Under the applied conditions, the cell extract contained no toxic PAs while phenylpropanoid pathway was active toward phenolic acids formation not toward naphthoquinone derivatives. Rosmarinic acid was produced as the main constituent. Total phenolic content and antioxidant capacity of the proliferated cell extracts were similar to those of the extracts of the natural plant tissues, in particular from the root. These results support the idea that the extract of L. officinale cells can be a reliable substitute for the extract of the natural plant tissues.

     

High-sensitive amperometric hydrazine sensor based on chemically synthesized zinc nitroprusside nanoparticle-supported carbon ceramic electrode

Zinc nitroprusside (ZnNP) nanoparticles were fabricated at the surface of zinc powder-doped carbon ceramic electrode (CCE) by a chemical derivatization process. This modified electrode was characterized by scanning electron microscopy, atomic force microscopy and cyclic voltammetry techniques. The charge transfer rate constant (k _s) and charge transfer coefficient (α) were calculated for the electron exchange reaction of the ZnNP thin film. The ZnNP nanoparticle-modified CCE (ZnNP|CCE) showed good electrocatalytic activity toward hydrazine oxidation. The limit of detection (S/N = 3) and sensitivity were found to be 0.16 µM and 0.21 µA/µM, respectively. The mechanism of hydrazine electrooxidation at the electrode surface was studied. Finally, the ZnNP|CCE was successfully used for the determination of trace amount of hydrazine in different spiked and real samples.