Analysis of lead molybdate and lead tungstate synthesized by a sonochemical method

Lead molybdate and lead tungstate nanoparticles were successfully synthesized by a sonochemical method for 1 h. XRD patterns showed the body-centered tetragonal structures of PbMoO₄ and PbWO₄, and were in accordance with those of the simulation and JCPDS software. Calculated lattice parameters are a = b = 5.4233 Å and c = 12.1253 Å for PbMoO₄, and 5.4570 Å and 12.0995 Å for PbWO₄. They are in accordance with those of the corresponding JCPDS software. TEM images show that the particles were 29.09 ± 5.22 nm and 21.05 ± 2.68 nm for PbMoO₄ and PbWO₄, respectively. Raman and FTIR vibrations were investigated to identify a definite existence of the structures.     

Thermal conductivity of Al2O3/water nanofluids

A considerable number of studies can be found on the thermal conductivity of nanofluids in which Al₂O₃ nanoparticles are used as additives. In the present study, the aim is to measure the thermal conductivity of very narrow Al₂O₃ nanoparticles with the size of 5 nm suspended in water. The thermal conductivity of nanofluids with concentrations up to 5 % is measured in a temperature range between 26 and 55 °C. Using the experimental data, a correlation is presented as a function of the temperature and volume fraction of nanoparticles. Finally, a sensitivity analysis is performed to assess the sensitivity of thermal conductivity of nanofluids to increase the particle loading at different temperatures. The sensitivity analysis reveals that at a given concentration, the sensitivity of thermal conductivity to particle loading increases when the temperature increases.     

Simple bead injection-flow injection system for the determination of copper.

We demonstrate the extended application of a simple bead injection-flow injection system with a modified simple colorimetric detection unit for the determination of low amount of Cu2+ in samples of different matrices (water and supplement tablet samples) with minimal sample pretreatment by employing ammonium pyrrolidinedithiocarbamate (APDC) reagent.     

Microwave-assisted synthesis and optical property of CdMoO4 nanoparticles

Microwave-assisted synthesis is a novel method used to synthesize CdMoO₄ nanoparticles in propylene glycol. The effects of reaction time and microwave power on phase, morphologies, and optical properties of CdMoO₄ nanoparticles were studied, using X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and UV-visible spectroscopy. The present analyses proved that these crystalline powders were scheelite-type tetragonal structured CdMoO₄, with the crystallite size of 14-20 nm, and 4.51-4.73 eV band gaps, controlled by the synthetic conditions.     

MRI and 1H MRS evaluation for the serial bile duct changes in hamsters after infection with Opisthorchis viverrini

A 3 T MR scanner was used to investigate the relationship between the alteration of bile duct lesions and the hepatic metabolic changes in hamsters infected with Opisthorchis viverrini by using 3 T MRI and ¹H MR spectroscopy. Animals were divided into control and infected groups. Five normal hamsters were used as control; fifty-five hamsters were infected with O. viverrini to induce bile duct lesions and hepatic metabolic changes. T2-weighted image sequence in three orthogonal planes were conducted by MRI scans. Single-voxel ¹H MRS was performed to obtain the relative choline-to-lipid ratios. The livers and bile ducts were excised for the histologic examination. The progression of bile duct changes by histology and metabolic changes in O. viverrini infected hamsters were co-investigated. In the O. viverrini-infected group, the T2-weighted images revealed the time-dependent intra- and extra-hepatic duct dilatations in the liver. The mean (± SD) choline-to-lipid ratios were 0.11 ± 0.035 in the control group, whereas the ratio in the infected group increased significantly with the progression of time. Histologic grading of hepatic inflammation and fibrosis were correlated well with the MRI grading (Spearman rank correlation test; r = 0.746 and p < 0.001). The control group showed no dilatation of the bile ducts and showed normal liver patterns. Noninvasive technique, MRI and ¹H MRS can demonstrated and applied to evaluate not only the inflammation-related fibrosis in the small bile ducts but also the metabolic changes in the liver induced by O. viverrini infection. A significant increase in the choline-to-lipids ratios were observed in parallel with the time-course of infection. O. viverrini infected in human is detected by stool examination. Hepatobiliary morbidity is detected and followed up by ultrasonography. MRI and MRS can be used in conjunction with ultrasonography for evaluation of progression of the disease.     

Effect of magnetic field on laminar forced convective heat transfer of MWCNT–Fe3O4/water hybrid nanofluid in a heated tube

Journal of Thermal Analysis and Calorimetry - A numerical investigation is carried out to assess the hydrothermal performance of a water-based hybrid nanofluid containing both Fe3O4 (magnetite)...     

An experimental investigation on the heat transfer characteristics of closed-loop pulsating heat pipe with graphene–water nanofluid

Journal of Thermal Analysis and Calorimetry - The heat transfer performance of a closed-loop pulsating heat pipe (CLPHP) having 2.2&nbsp;mm inner diameter is experimentally studied at different...     

Microwave-assisted hydrothermal synthesis of BiOCl/Bi2WO6 nanocomposites for the enhancement of photocatalytic efficiency

Research on Chemical Intermediates - In this research, BiOCl/Bi2WO6 nanocomposites were successfully synthesized by a microwave-assisted hydrothermal method. Phase, morphology and optical...     

Postbuckling behavior of variable-arc-length elastica connected with a rotational spring joint including the effect of configurational force

This paper aims to study the behavior of a variable-arc-length (VAL) elastica subjected to the end loading, where a rotational spring joint is placed within the span length of the elastica. One end of the elastica is rested on the pinned support while the other end is placed into the sleeve support. The length of the elastica can be fed into the system through sleeve support by the end thrust where the effect of configurational force has been considered. A rotational spring joint is located within the span length of the elastica. From the equilibrium equations, moment–curvature expression, geometric relations, and boundary conditions, the closed-form solution in terms of elliptic integral of the first and second kinds can be demonstrated. The results obtained from elliptic integral method are validated with those from the shooting method and they are in excellent agreement. In order to interpret the behavior of the elastica, load–deflection curves and equilibrium shapes are established. Interesting features of the results are demonstrated. Particularly, when the stiffness of the spring joint becomes zero, the secondary buckling and the multiple equilibrium shapes can be captured in which the stable equilibrium shapes can be evaluated by using the vibration analysis. For a low value of the stiffness of the spring joint, the elastica has a possibility to exhibit the hardening behavior. When the stiffness of the spring joint becomes large, the elastica shows the softening behavior and its shape is identical to a single portion of VAL elastica.