Area-selective growth of amorphous carbon nanofibers via catalytic decomposition of polyimide thin film

A dense layer of amorphous carbon nanofibers was fabricated by pyrolyzing a thin film of polyimide using a monolayer of gold nanoparticles as a catalyst.     

Flavonoid profiling in three citrus varieties native to the Republic of Korea using liquid chromatography coupled with tandem mass spectrometry: contribution to overall antioxidant activity

A mixture of flavonoid components was isolated from the fruit peel of three varieties of citrus native to Republic of Korea, Citrus leiocarpa Hort. ex Tanaka (CLHT), Citrus aurantium L. (CAL) and Citrus erythrosa Hort. (CEH), via 70% methanol extraction followed by ethyl acetate elution over a silica gel cartridge. The flavonoid components of the mixture were analyzed via high‐performance liquid chromatography–tandem mass spectrometry (HPLC‐MS/MS) in positive‐ion mode and a comparison of the reported data. Among 17 characterized components, two flavanones, four flavones and two coumarin derivatives in the fruit peel of the three varieties were identified for the first time. The individual characterized components were quantified via HPLC‐UV. The flavanones dominated in CAL, whereas the flavones prevailed in CLHT and CEH. The antioxidant activity of the flavonoid mixture of the fruit peel was determined via DPPH^?, ABTS^?+ and reducing power assays. The antioxidant activity of CEH and CAL was greater than that of CLHT. Copyright © 2011 John Wiley & Sons, Ltd.     

On convergence,asymptotic behaviour and computational algorithm of generalized exponential integral functions arising in a radiative transfer

In this paper, we investigate uniform convergence of the generalized exponential integral functions (GEI) arising in the study of radiative transfer in a two-dimensional planar-medium and anisotropic scattering in a multidimensional medium. Using the uniform convergence, we study the properties and asymptotic behaviour of the GEI functions. We also give an efficient algorithm for the computations of the values of the GEI functions.     

HOLDITCH THEOREM FOR THE CLOSED SPACE CURVES IN LORENTZIAN 3-SPACE

In this article, we give the area formula of the closed projection curve of a closed space curve in Lorentzian 3-space L3. For the 1-parameter closed Lorentzian space motion in L3, we obtain a Holditch Theorem taking into account the Lorentzian matrix multiplication for the closed space curves by using their othogonal projections onto the Euclidean plane in the fixed Lorentzian space. Moreover, we generalize this Holditch Theorem for noncollinear three fixed points of the moving Lorentzian space and any other fixed point on the plane which is determined by these three fixed points.     

Path Integral Quantization of a Spinning Particle

Barut's classical model of the spinning particle having external dynamical variables x and p and internal dynamical variables and z is taken into account. The path integrations over holomorphic spinors and z are discussed. This quantization gives the kernel of the relativistic particles with higher spin as well as the Dirac electron. The Green's function of the spin-n/2 particle is obtained.     

Synthesis and crystal structure of bis[2-[N-(2-chlorophenyl)formimidayl]-1-naphtholato]-(6Cl)copper(II)

The title compound, bis[2-[N-(2-chlorophenyl)formimidayl]-1-naphtholato]-(6Cl) copper(II), [Cu(C₁₇H₁₁NOCl)₂] (1) was synthesized and its crystal structure was determined. The Compound 1 is monoclinic, space group P2 ₁/c with a = 9.146(3) Å, b = 18.724(3) Å, c = 16.230(2) Å, β = 96.46(1)°, V = 2761.8(11) ų, Z = 4, D _c = 1.503 g cm^?3, μ(Mo Kα) = 1.020 mm^?1, R = 0.0606 for 2361 reflections [I > 2σ(I)]. In the title compound, the Cu atom is coordinated by an N₂O₂ donor set from the imine-phenol ligand in a slightly distorted square planar coordination geometry, with the two phenolate O atoms being deprotonated. The Cu–O bond lengths are 1.878(4) and 1.889(4) Å, the Cu–N bond lengths are 1.980(5) and 1.985(5) Å. The angles O1–Cu–N1 and O2–Cu–N2 are 90.96(19) and 90.72(19)°, respectively.     

Numerical Study of Heat Transfer in a Rectangular Channel with Porous Covering Obstacles

A numerical study is performed to analyze steady laminar forced convection in a channel in which discrete heat sources covered with porous material are placed on the bottom wall. Hydrodynamic and heat transfer results are reported. The flow in the porous medium is modeled using the Darcy–Brinkman–Forchheimer model. A computer program based on control volume method with appropriate averaging for diffusion coefficient is developed to solve the coupling between solid, fluid, and porous region. The effects of parameters such as Reynolds number, Prandtl number, inertia coefficient, and thermal conductivity ratio are considered. The results reveal that the porous cover with high thermal conductivity enhances the heat transfer from the solid blocks significantly and decreases the maximum temperature on the heated solid blocks. The mean Nusselt number increases with increase of Reynolds number and Prandtl number, and decrease of inertia coefficient. The pressure drop along the channel increases rapidly with the increase of Reynolds number.     

Natural convection heat transfer in enclosures with conducting multiple partitions and side walls

The flow and heat transfer in enclosures with conducting multiple partitions and side walls were numerically analyzed. Side walls were kept at isothermal conditions, while top and bottom walls were insulated. Employing control volume approach, a computer program based on SIMPLE algorithm was developed. Computations were carried out to investigate the effects of Rayleigh number, number of partitions and cavity aspect ratios on the heat transfer rate. The mean Nusselt numbers were calculated from computed temperature fields. It was observed that, the mean Nusselt number decreases with increasing partition number. It is inversely proportional to (1+N) for N≤4. For all partition numbers, the mean Nusselt number increases with increasing Rayleigh number. On the other hand, the cavity aspect ratio does not affect the mean Nusselt number to a considerable extent for considered aspect ratios in this study.