Rheological behaviour of emulsions of avocado and watermelon oils during storage

Rheological properties of emulsions made out of avocado pulp and watermelon seed oils with whey protein concentrate were determined during different storage periods. The oils, as well as the emulsions behaved like non-Newtonian liquids, having shear-thinning characteristics. Both oils showed moderate shear-thinning characteristics as the flow behaviour indices were between 0.86 and 0.88. The shear-rate/shear-stress data could be adequately fitted (r = 0.997–0.999) to a common rheological equation, e.g. the power-law model. Avocado pulp oil was markedly more viscous than was watermelon seed oil which was also evident from the higher apparent viscosity and consistency index values.     

Synthesis,structural and optical characterization of ZrO2 core–ZnO@SiO2 shell nanoparticles prepared using co-precipitation method for opto-electronic applications

Nanocrystalline Zirconia (ZrO₂) and Zinc oxide (ZnO) as well as Silica (SiO₂) coated ZrO₂ core–shell structures were synthesized by both Co-precipitation and seeded polymerization technique. The phase analysis and the core–shell structure formation were confirmed by X-ray diffraction (XRD), FESEM and high resolution transmission electron microscopy (HRTEM) analysis. The existence of SiO₂ on ZrO₂@ZnO was characterized by FT-IR measurement. UV–Vis study reveals coating of ZnO over Zirconia shows red shift in the absorption spectra. Photoluminescence studies show the non-monotonous variation in luminescence behavior of these core–shell nanoparticles. This investigation explains that the interfacial effect between the core (ZrO₂) and the shell materials (ZnO and SiO₂) can be exploited to tune the optical properties of the material. This implies that we can envisage the core–shell materials as potential candidates for optical–electronic devices.     

Basis arrays and successive packing for M-D interleaving

In this paper, we first present a novel concept of 2-D basis interleaving array (also referred to as basis array for short). That is, an m × m interleaved array is said to be a basis array if the shortest distance among all pairs of elements in each of the so-called m-equivalent sets within the m × m array reaches the maximum. It is shown that this maximum is given by ${\lfloor \sqrt{2m} \rfloor}$ and an m × m basis array can be constructed by using a simple cyclic translation method. The previously developed concept of successive packing is then generalized in the sense that it can be applied to any basis array to generate an interleaved array with a larger size. Except that optimality cannot be guaranteed, the concept of basis arrays and successive packing are extended to M-D cases. It is shown that for any M ?? 2, the proposed technique can spread any error burst of block size ${m_{1}^{k} \times m_{2}^{k} \times \cdots \times m_{M}^{k}}$ within an ${ m_{1}^{n} \times m_{2}^{n} \times \cdots \times m_{M}^{n}}$ array (1 ?? k ?? n?1) so effectively that the error burst can be corrected with some simple random error-correcting code (provided the error-correcting code is available). It is shown that important prior results in M-D interleaving such as the t-interleaved array based approach by Blaum et al. and the successive packing approach by Shi and Zhang now become special cases of the framework based on basis arrays and successive packing, proposed in this paper.     

Fracture toughness of foams with tetrakaidecahedral unit cells using finite element based micromechanics

Fracture toughness of open-cell foams consisting of tetrakaidecahedral unit cells is predicted by simulating crack propagation using a finite element (FE) based micromechanical model. The inputs to the model are the geometric parameters required to model the repeating unit cell and tensile strength of the foam ligament or strut. Cracks are created by removing certain number of cells pertaining to a crack length. The FE model consists of a local micro-scale region surrounding the crack tip. For an assumed stress intensity factor, the displacements along the boundary of the local model are calculated based on linear elastic fracture mechanics for orthotropic materials. The stresses in the ligaments ahead of the crack tip calculated from this micro-model in conjunction with the tensile strength of the strut material are used to predict fracture toughness. A parametric study with different micro-model sizes and different crack lengths is performed to check for convergence of predicted Mode-I, Mode-II and mixed mode fracture toughness values. The effect of applying rotations as additional boundary conditions along with translational displacement boundary conditions on the predicted fracture toughness values is also studied.     

FDM analysis for MHD flow of a non-Newtonian fluid for blood flow in stenosed arteries

A computational model is developed to analyze the effects of magnetic field in a pulsatile flow of blood through narrow arteries with mild stenosis, treating blood as Casson fluid model. Finite difference method is employed to solve the simplified nonlinear partial differential equation and an explicit finite difference scheme is obtained for velocity and subsequently the finite difference formula for the flow rate, skin friction and longitudinal impedance are also derived. The effects of various parameters associated with this flow problem such as stenosis height, yield stress, magnetic field and amplitude of the pressure gradient on the physiologically important flow quantities namely velocity distribution, flow rate, skin friction and longitudinal impedance to flow are analyzed by plotting the graphs for the variation of these flow quantities for different values of the aforesaid parameters. It is found that the velocity and flow rate decrease with the increase of the Hartmann number and the reverse behavior is noticed for the wall shear stress and longitudinal impedance of the flow. It is noted that flow rate increases and skin friction decreases with the increase of the pressure gradient. It is also observed that the skin friction and longitudinal impedance increase with the increase of the amplitude parameter of the artery radius. It is also found that the skin friction and longitudinal impedance increases with the increase of the stenosis depth. It is recorded that the estimates of the increase in the skin friction and longitudinal impedance to flow increase considerably with the increase of the Hartmann number.     

Solution Processing Route to Multifunctional Titania Thin Films: Highly Conductive and Photcatalytically Active Nb:TiO2

This paper reports the synthesis of highly conductive niobium doped titanium dioxide (Nb:TiO₂) films from the decomposition of Ti(OEt)₄ with dopant quantities of Nb(OEt)₅ by aerosol‐assisted chemical vapor deposition (AACVD). Doping Nb into the Ti sites results in n‐type conductivity, as determined by Hall effect measurements. The doped films display significantly improved electrical properties compared to pristine TiO₂ films. For 5 at.% Nb in the films, the charge carrier concentration was 2 × 10²¹ cm^?3 with a mobility of 2 cm² V^–1 s^–1 . The corresponding sheet resistance is as low as 6.5 Ω sq^–1 making the films suitable candidates for transparent conducting oxide (TCO) materials. This is, to the best of our knowledge, the lowest reported sheet resistance for Nb:TiO₂ films synthesized by vapour deposition. The doped films are also blue in colour, with the intensity dependent on the Nb concentration in the films. A combination of synchrotron, laboratory and theoretical techniques confirmed niobium doping into the anatase TiO₂ lattice. Computational methods also confirmed experimental results of both delocalized (Ti⁴⁺) and localized polaronic states (Ti³⁺) states. Additionally, the doped films also functioned as photocatalysts. Thus, Nb:TiO₂ combines four functional properties (photocatalysis, electrical conductivity, optical transparency and blue colouration) within the same layer, making it a promising alternative to conventional TCO materials.     

功能梯度类金刚石薄膜的脉冲激光制备

长期以来 ,高质量的纯类金刚石薄膜的成功制备一直受其巨大内部压应力的阻碍 ,因为这种压应力导致严重的附着问题。厚度大于 50 0nm的类金刚石薄膜中的压应力常使薄膜与基体剥离。作者采用功能梯度的设计概念 ,应用准分子脉冲激光沉积方法 ,成功制备了厚度超过 1 0 μm的高质量类金刚石薄膜。薄膜中的SP3碳原子含量超过 6 0 %。纳米硬度测试表明 ,薄膜的弹性模量高达 50 0GPa ,纳米硬度高达 6 0GPa ,薄膜与基体间附着良好。证明功能梯度的设计概念可以用于制备较厚的超硬类金刚石薄膜。     

光纤传输电视伴音的二次调制技术

本文简述光纤传输电视伴音的二次调制技术的基本原理,并对实现二次调制的实际电路进行了详细分析。     

钢渣桩在湿陷性黄土地基中的应用探讨

通过钢渣桩在湿陷性黄土中的静荷载试验、土压力测试等试验结果的基础上,对钢渣桩复合地基、桩间土和钢渣单桩的p-s曲线以及其各自的承载力和相应的沉降量进行了分析,探讨了附加应力沿深度变化规律;研究了桩间土承载力、桩土应力比和桩土荷载比的变化规律,对钢渣单桩和碎石桩以及钢渣桩复合地基和石灰粉煤灰桩复合地基等的承载力特性进行了对比分析;对单桩施工影响范围和施工时地基隆起量进行了观测。