Tissue distribution of perfluorinated chemicals in harbor seals (Phoca vitulina) from the Dutch Wadden Sea

Perfluorinated acids (PFAs) are today widely distributed in the environment, even in remote arctic areas. Recently, perfluorooctane sulfonate (PFOS) has been identified in marine mammals all over the world, but information on the compound-specific tissue distribution remains scarce. Furthermore, although longer perfluorinated carboxylic acids (PFCAs) are used in industry and were shown to cause severe toxic effects, still little is known on potential sources or their widespread distribution. In this study, we report for the first time on levels of longer chain PFCAs, together with some short chain PFAs, perfluorobutane sulfonate (PFBS) and perfluorobutanoate (PFBA), in liver, kidney, blubber, muscle, and spleen tissues of harbor seals (Phoca vitulina) from the Dutch Wadden Sea. PFOS was the predominant compound in all seal samples measured (ranging from 89 to 2724 ng/g wet weight); however, large variations between tissues were monitored. Although these are preliminary results, it is, to our knowledge, the first time that PFBS could be found at detectable concentrations (2.3 +/- 0.7 ng/g w wt) in environmental samples. PFBS was only detected in spleen tissue. PFCA levels were much lower than PFOS concentrations. The dominant PFCA in all tissues was PFNA (perfluorononanoic acid), and concentrations generally decreased in tissues for all other PFCA homologues with increasing chain length. No clear relationship between PFOS levels in liver and kidney was observed. Furthermore, hepatic PFDA (perfluorodecanoic acid) levels increased with increasing body length, but in kidney tissue, PFDA levels showed an inverse relationship with increasing body length. These data suggest large differences in tissue distribution and accumulation patterns of perfluorinated compounds in marine organisms.     

Hall and ion slip effects on MHD laminar flow of an elastico‐viscous (Walter's‐B) fluid

We investigated the magnetohydrodynamic (MHD) laminar flow of an elastico‐viscous electrically conducting (Walter's‐B) fluid through a circular cylinder or pipe, loosely packed with a porous material subjected to Hall and ion‐slip effects. The innovation of the study is to consider the entire flow domain without boundary layer approximation in the governing equations. Fully developed solutions of the velocity and pressure drop are obtained making use of perturbation approximation and computationally discussed with reference to flow governing parameters. It is quite exciting that the elastic parameter almost reduces the speed of the liquid in the center of the channel and then continuously expands into the cylinder. For engineering interest, we found the analytical solution and then computationally discussed for skin friction. The occurrence of a magnetic field and a porous matrix gives a fairly uneven flow between the pipes. Elasticity and suction are resistant to experience greater skin friction and are therefore useful for controlling flow separation. A porch has been made to include studies of non‐Newtonian fluids with Hall and ion‐slip effects due to the vast number of possible engineering applications, like power generators, MHD accelerators, refrigeration coils, electric transformers, and heating elements.     

Mechanical,Thermal, and Interfacial Characterization of Randomly Oriented Short Sisal Fibers Reinforced Epoxy Composite Modified with Epoxidized Soybean Oil

Short sisal fibers were reinforced in epoxidized soybean oil (ESO) modified toughened epoxy blends to improve the mechanical and thermo mechanical properties. Tensile modulus and tensile strength of the composite with 15 wt% sisal fiber were found to be increased as compared with bio-based epoxy blend. From DTG analysis, rate of degradation peak is found to be shifted to higher temperature revealing enhanced thermal stability of composite over base matrix. Dynamic mechanical analysis predicted higher storage modulus and higher glass transition temperature of bio-based epoxy composite. Scanning electron micrographs showed strong fiber-matrix adhesion. Contact angle measurement reveals the hydrophilic character of bio-based epoxy composite     

Densitometric quantification for the validation of decolorization of Disperse Orange ERL by lichen Parmelia sp.

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Effects of Cattaneo–Christov heat flux analysis on heat and mass transport of Casson nanoliquid past an accelerating penetrable plate with thermal radiation and Soret–Dufour mechanism

In this analysis, the effect of Catteneo–Christov model on heat alongside mass transport magnetohydrodynamics of a Casson nanoliquid with thermal radiation and Soret–Dufour mechanism is considered. The fluid flow is considered through porous media as the thermophysical attributes such as viscosity along with thermal conductivity are considered to be constant. Suitable similarity transformations were employed on the governing coupled flow equation to yield total differential equations (ODE). An accurate and newly developed spectral method called spectral homotopy analysis method (SHAM) was employed to provide solution to the simplified equations. The numerical method of homotopy analysis method (HAM) is SHAM. SHAM portrays the division of nonlinear equations into linear as well as nonlinear parts. The findings in this study show that an increment in the Casson parameter is seen to elevate the velocity plot at the wall and lessen the velocity far away from the plate. An increase in the Brownian motion and thermophoresis term is observed to speed up the local skin friction coefficient.     

Evaluation of mechanical properties of hybrid Al7009 nanocomposite

ABSTRACT

Hybrid nanocomposites are prepared by Al7009 aluminum alloy as base material,graphite and nano magnesium oxide (MgO) as reinforcements. Stir casting processes are used for preparation of hybrid nanocomposite, the percentage of graphite is fixed at 1 wt.% and nano magnesium oxide is varied for 1%, 2%, and 3% by weight and the specimens are named as A (pure), B (1% graphite and 1% MgO), C (1% graphite and 2% MgO), and D (1% graphite and 3% MgO). Evaluation of mechanical properties such as compressive strength, hardness, density, and impact strength behavior of hybrid Al7009 nano aluminum composites are analyzed. From the experimental results, the compressive strength and hardness of hybrid nanocomposite increases up to 2% wt of nano MgO particles and then the value decreases for 3% wt of nano MgO particles. Density increases from the specimens A to C with an increase in percentage of reinforcement in the matrix phase and then it decreases for specimen D. With respect to toughness highest value of 4.4 Jis obtained for sample D and the increase in percentage was 62.9 when compared to sample A, it was 37.5% when compared to specimen B and 12.8% when compared to specimen C.     

Rapid characterisation of brown and white rot degraded chir pine and rubberwood by FTIR spectroscopy

Pinus roxburghii (chir pine) and Hevea brasiliensis (rubberwood) were degraded by brown-rot (Polyporus meliae) and white-rot (Trametes versicolor and Trametes hirsuta) fungi. The modification in the chemical structure of degraded wood was monitored by FTIR spectroscopy. In wood decayed by brown rot, there was a progressive increase in the lignin content, which is evident from increase in the relative intensities of lignin associated bands and a corresponding decrease in the intensities of carbohydrate bands. In contrast, there was a decrease in the lignin content of white rot decayed wood. Both the white rots used in this study showed preferential degradation of lignin, which is indicated by a reduction in relative intensities of lignin associated bands.