Peristaltic motion of Sisko fluid in an inclined asymmetric tapered channel with nonlinear radiation

Peristaltic pumping of Sisko fluid through the non-uniform asymmetric channel is addressed. Main motivations are given to nonlinear radiation and inclined magnetic field. The perturbation technique and lubrication approach are utilized for development of governing problems and solutions. Resulting equations are solved for velocity, temperature, pressure and stream function. Trapping phenomenon is also observed. Variation of pertinent parameters is plotted and illustrated physically. The larger inclination of the magnetic field leads to a rise in velocity. Moreover, the size of trapping bolus tends to reduce and finally disappears for the larger fluid parameter. To our knowledge, such attempt for linear radiation and without inclined magnetic field does not exist even for both symmetric and asymmetric channels. Further it should be noted that problem remains nonlinear even after utilizing long wavelength and low Reynolds number assumptions.

     

Microbial transformation of oleanolic acid by Fusarium lini and alpha-glucosidase inhibitory activity of its transformed products

The biotransformation of a pentacyclic triterpene, oleanolic acid (1), with Fusarium lini afforded two oxidative metabolites, 2alpha,3beta-dihydroxyolean-12-en-28-oic acid (2), and 2alpha,3beta,11beta-trihydroxyolean-12-en-28-oic acid (3). Metabolite 3 was found to be a new compound. The structures were characterized on the basis of spectroscopic studies. These metabolites exhibited a potent inhibition of alpha-glucosidase enzyme.     

Synthesis and characterization of new soluble and thermally stable poly(ester-imide)s derived from N-[3,5-bis(N-trimellitoyl)phenyl]phthalimide and various bisphenols

A new dicarboxylic acid chloride (2) bearing three preformed imide rings was synthesized by treating N-(3,5-diaminophenyl)phthalimide with trimellitic anhydride followed by refluxing with thionyl chloride. A novel family of aromatic poly(ester-imide)s with inherent viscosities of 0.27-0.35 dl g⁻¹ were prepared from 2 with various bisphenols such as resorcinol (3a), hydroquinone (3b), 2,2′-dihydroxybiphenyl (3c), 4,4′-dihydroxybiphenyl (3d), bisphenol-A (3e), 2,2′-dimethyl-4,4′-dihydroxybiphenyl (3f), 1,5-dihydroxynaphthalene (3g), 2,7-dihydroxynaphthalene (3h), and 2,2′-dihydroxy-1,1′-binaphthyl (3i) by high-temperature solution polycondensation in nitrobenzene using pyridine as hydrogen chloride quencher. All of the resulted polymers were fully characterized by FT-IR and NMR spectroscopy and elemental analyses. The poly(ester-imide)s exhibited excellent solubility in some polar organic solvents. From differential scanning calorimetry, the polymers showed glass-transition temperatures between 259 and 353 °C. Thermal behaviors of the obtained polymers were characterized by thermogravimetric analysis and the 10% weight loss temperatures of the poly(ester-imide)s were found to be in the range between 451 and 482 °C in nitrogen. Furthermore, crystallinity of the polymers was estimated by means of wide-angle X-ray diffraction.     

Geological and radiological studies of the Mount Arafat, Mekkah, Saudi Arabia

Mount Arafat is a sacred place for Muslims. It has been classified as a granodiorite rock which mainly consists of feldspar and quartz, muscovite, etc. During the Hajj and Umra, Muslims visit this holly place and stay there for some time. In order to study the geology and thermal history as well as to assess the radiological hazards due to the presence of primordial radionuclides, systematic studies using petrographic, fission track dating and γ-spectrometric (HPGe) techniques were carried out. Our study yielded fission track age of 9.13 ± 1.05 Ma of the Mount Arafat granodiorite. Rifting, magmatism, volcanism and sea floor spreading that resulted in the formation of Red Sea seems may have altered the original age of the Arafat granodiorite under study to 9.13 ± 1.05 Ma. Measured radioactivity concentrations due to ²²⁶Ra, ²³²Th and ⁴⁰K were found to be 10.75 ± 3.92, 29.21 ± 4.34 and 664.49 ± 7.45 Bq kg^?1, respectively. From the measured radioactivity, gamma index (Iγ) and radium equivalent (Ra_eq) were calculated as 0.402 and 103.23 Bq kg^?1 whereas outdoor external dose (D_out) and annual effective dose (E_out) were estimated to be 40.30 nGyh^?1 and 0.045 mSvy^?1 respectively. All the above mentioned values are well below the recommended limits. The Mount Arafat thus does not pose any radiological health hazard to the general public.     

Ion-Temperature-Gradient-Driven Modes with Nonthermal Electron Distributions in Bi-ion Dusty Magnetoplasma

The effect of nonthermal distributions of electrons on ion-temperature-gradient (ITG)-driven drift modes in the presence of tiny dust particles for bi-ion magneto plasmas is investigated. The dynamics of bi-ions and dust particles is considered for the study of low-frequency (less than the gyrofrequencies of dust and ions) ITG mode. A new dispersion relation is derived and analyzed numerically as well as analytically. Three different distributions for nonthermal electrons (Kappa, q, and Cairns distribution) are used. It is found that the presence of nonthermal electrons in bi-ion dusty magnetoplasma reduces the growth rate of the ITG instability. These results should be useful for laboratory and space plasmas where nonthermal electrons and dust is always present.     

Structural characterization of a mixed-ligand complex of copper(II) with 1,10-phenanthroline and the <Emphasis Type="Italic">m</Emphasis>-aminobenzoate ion

A new copper(II) complex of 1,10-phenanthroline (C1₂H₈N₂) and the meta-aminobenzoate ion (m-amb; C₇H₆NO ₂ ^? ), having the formula Cu(C₁₂H₈N₂)(C₇H₆NO₂)Cl?0.5H₂O, is prepared and characterized by elemental analysis, IR spectroscopy, and single crystal X-ray diffraction. The structure is built up from monomeric units in which the coordination environment around the metal ion is a square plane arising from a bidentate 1,10-phenanthroline molecule, a monodentate m-amb anion, and a chloride ion. A very long (Cu–N = 2.856(5) Å) bond to the nitrogen atom of an adjacent m-amb ion generates [101] polymeric chains in the crystal. The crystal structure is consolidated by N–H???O and O–H???O hydrogen bonds and C–H???O, C–H???Cl, and aromatic π–π stacking interactions. Crystal data: C₁₉H₁₅ClCuN₃O_2.5, M _r = 424.33, monoclinic, P2₁/n (No. 14), a = 9.8200(5) Å, b = 10.9291(7) Å, c = 16.3803(9) Å, β = 105.293(3)°, V = 1695.74(17) ų, Z = 4, R(F) = 0.043, wR(F ²) = 0.122.     

Nanofibrous Scaffolds with Biomimetic Composition for Skin Regeneration

Applied Biochemistry and Biotechnology - Treatments of skin injuries caused by trauma and diseases are among the most considerable medical problems. The use of scaffolds that can cover the wound...