Clustering of heavy particles in vortical flows: a selective review

Heavy particles in a turbulent flow tend to leave regions of high vorticity and cluster into regions of high strain. The consequences of such clustering have been studied in a variety of situations over the past few decades, and this problem has seen several review papers already. Our objectives in this paper are three-fold. (i) We introduce the reader to the basic ideas, and explain why the problem is interesting. (ii) Using an N-vortex system we present an interesting case where particles are attracted to the vicinity of vortices. A new scaling for the critical Stokes number of attraction is obtained. (iii) We review a number of papers, which are related to cloud physics in this context.     

Double-hierarchy hesitant fuzzy linguistic information-based framework for green supplier selection with partial weight information

Neural Computing and Applications - Green supplier selection (GSS) is a crucial issue in green supply chain management. CAPS indicate that industries spend yearly USD 25 million per procurement,...     

Performance of zinc phosphate coatings obtained by cathodic electrochemical treatment in accelerated corrosion tests

The formation of zinc phosphate coating by cathodic electrochemical treatment and evaluation of its corrosion resistance is addressed. The corrosion behaviour of cathodically phosphated mild steel substrate in 3.5% sodium chloride solution exhibits the stability of these coatings, which lasts for a week's time with no red rust formation. Salt spray test convincingly proves the white rust formation in the scribed region on the painted substrates and in most part of the surface on unpainted surface. The protective ability of the zinc corrosion product formed on the surface of the coated steel is evidenced by the decrease in the loss in weight due to corrosion of the uncoated mild steel, when it is galvanically coupled with cathodically phosphated mild steel. Potentiodynamic polarization curves reveal that E_corr shifts towards higher cathodic values (in the range of −1000 to −1100 mV versus SCE) compared to that of uncoated mild steel and conventionally phosphated mild steel substrates. The i_corr value is also very high for these coatings. EIS studies reveal that zinc dissolution is the predominant reaction during the initial stages of immersion. Subsequently, the non-metallic nature of the coating is progressively increased due to the formation of zinc corrosion products, which in turn enables an increase in corrosion resistance with increase in immersion time. The zinc corrosion products formed may consist of zinc oxide and zinc hydroxychloride.     

Enhanced visible light responsive photocatalysis by ZnO:Mg/RGO nanocomposites

Mg and RGO activated ZnO nanocomposites were prepared using a low-cost soft chemical method. As per the structural studies the samples exhibit wurtzite structure of ZnO with hexagonal crystal system. No secondary phases were observed. The photocatalytic activity of the prepared samples were assessed through the degradation of cationic dyes, methylene blue (MB) and malachite green (MG) under visible light irradiation. The studies revealed that the ZnO:Mg/RGO nanocomposite exhibits enhanced photocatalytic as well as antibacterial behavior compared to bare ZnO. The optical, structural and surface morphological studies support the reports on the photocatalytic and antibacterial activities of the synthesized samples.     

Application of digital image correlation method to biogel

This study adopts the digital image correlation (DIC) method to measure the mechanical properties under tension in agarose gels. A second polynomial stress–strain equation based on a pore model is proposed in this work. It shows excellent agreement with experimental data and was verified by finite element simulation. Evaluation of the planer strain field by DIC allows measurement of strain localization and Poisson's ratio. At high stresses, Poisson's ratio is found to exceed the standard assumption of 0.5 which is shown to be a result of pore water leakage. Local failure strains are found to be approximately twice those determined by crosshead displacements. Viscous properties of agarose gels are investigated by performing the tensile tests at various loading rates. Increases in loading rate do not cause much difference in the shape of stress–strain curves, but result in increases in ultimate stress and strain. POLYM. ENG. SCI., 50:1585–1593, 2010. © 2010 Society of Plastics Engineers     

Tuning violet to green emission in luminomagnetic Dy,Er co-doped ZnO nanoparticles

This paper discusses the synthesis of undoped ZnO, 2?mol% Dy doped ZnO, 2?mol% Er doped ZnO and 1?mol% Dy,Er co-doped ZnO nanoparticles by simple combustion technique and the characterization of their structural, morphological, magnetic and optical properties by X-ray diffraction (XRD), X-Ray Photoelectron Spectroscopy(XPS), Field Emission Scanning Electron Microscope (FESEM), High Resolution Transmission Electron Microscope (HRTEM), Diffuse Reflectance Spectroscope (DRS), Vibrating Sample Magnetometer (VSM) and Photoluminescence(PL). All samples are of hexagonal wurzite type structure which was found from XRD analysis. The effects of annealing on morphology and luminescence emission wavelengths were noticed in FESEM and PL, respectively. As-prepared sample displayed spherical morphology and annealed co-doped sample showed interwoven hexagonal stacking like morphology. VSM revealed the room temperature ferromagnetism in doped samples. The photoluminescence under the UV and IR excitations was observed in experiment. The as-prepared samples had violet region emission at the 325?nm excitation. The annealed samples had green region emission under the same excitation. Due to the annealing effect, the enhancement of upconversion luminescence intensity in co-doped sample in green (535?nm) and red (665?nm) regions was observed at the 980?nm excitation.     

Radical Roles for RAGE in the Pathogenesis of Oxidative Stress in Cardiovascular Diseases and Beyond

Oxidative stress is a central mechanism by which the receptor for advanced glycation endproducts (RAGE) mediates its pathological effects. Multiple experimental inquiries in RAGE-expressing cultured cells have demonstrated that ligand-RAGE interaction mediates generation of reactive oxygen species (ROS) and consequent downstream signal transduction and regulation of gene expression. The primary mechanism by which RAGE generates oxidative stress is via activation of NADPH oxidase; amplification mechanisms in the mitochondria may further drive ROS production. Recent studies indicating that the cytoplasmic domain of RAGE binds to the formin mDia1 provide further support for the critical roles of this pathway in oxidative stress; mDia1 was required for activation of rac1 and NADPH oxidase in primary murine aortic smooth muscle cells treated with RAGE ligand S100B. In vivo, in multiple distinct disease models in animals, RAGE action generates oxidative stress and modulates cellular/tissue fate in range of disorders, such as in myocardial ischemia, atherosclerosis, and aneurysm formation. Blockade or genetic deletion of RAGE was shown to be protective in these settings. Indeed, beyond cardiovascular disease, evidence is accruing in human subjects linking levels of RAGE ligands and soluble RAGE to oxidative stress in disorders such as doxorubicin toxicity, acetaminophen toxicity, neurodegeneration, hyperlipidemia, diabetes, preeclampsia, rheumatoid arthritis and pulmonary fibrosis. Blockade of RAGE signal transduction may be a key strategy for the prevention of the deleterious consequences of oxidative stress, particularly in chronic disease.     

Thermomechanical behavior of single crystalline tantalum in the static and dynamic regime

This paper reports the thermomechanical behavior of single crystalline tantalum (Ta) in the [1 0 0] and [1 1 0] orientations. Mechanical testing was carried out at low and high strain rates using a Kolsky bar together with the simultaneous recording of the specimen’s temperature by means of an infrared detector. The results show a marked difference in terms of flow curve and strain hardening between the two orientations, irrespective of the strain-rate. Similarly, the thermomechanical behavior, namely the efficiency of the thermomechanical conversion at high strain-rates (β_int), is observed to be different for each orientation. A comparison of the present results with those obtained for pure polycrystalline Ta (Rittel et al., 2007) reveals some similarity of flow curves with the [1 0 0] orientation. By contrast, the [1 1 0] orientation is observed to possess β_int characteristics that are similar to those of the polycrystalline material. These results are presented and discussed, thus completing the overall experimental characterization of this material in order to enable the simulation and validation of the dynamic behavior of polycrystalline Ta on the basis of its single-crystal characteristics.     

Influence of Annealing Temperatures on Structural and Magnetic Properties for Cr-Based Inverse Heusler Alloy Nanoparticles

Journal of Superconductivity and Novel Magnetism - The Cr2FeAl inverse-based Heusler alloy nanoparticle was synthesized using mechanical alloy method. The as-prepared sample was annealed at various...