Investigation of Crystal Structure,Electrical and Magnetic Properties of Spinel Mn-Cd Ferrite Nanoparticles

Journal of Inorganic and Organometallic Polymers and Materials - Cd1 ? xMnxFe2O4 (x?=?0, 0.25, 0.5, 0.75, 1) spinel ferrite nanoparticle samples were synthesized...     

Adsorption behavior of Co(II) and Ni(II) from aqueous solutions onto titanate nanotubes

Adsorption of Co²⁺ and Ni²⁺ from aqueous solutions onto titanate nanotubes (TNTs) synthesized by hydrothermal method in single and binary systems was investigated. The prepared TNTs were completely characterized showing very high surface area compared to previous studies (320 m²/g). The high surface area showed very good optimum removal conditions compared with previous studies (60 min contact time, 0.1 g TNTs dose at pH 5 and room temperature) with high adsorption capacity compared with previous studies as well as conventional adsorbent. Langmuir and Freundlich isothermal models were fitted during this study and Dubinin–Kaganer–Radushkevich isotherms showed physisorption with exclusion of ion exchange mechanism. Pseudo first and second-order kinetics were studied showing more fitting to pseudo second-order equation. Binary system and calculation of separation coefficient showed high ability for Co²⁺ adsorption by TNTs than Ni⁺² in binary system.     

Immobilisation of TiO2-nanoparticles on sewage sludge and their adsorption for cadmium removal from aqueous solutions

In this study, pure TiO₂-nanoparticles and TiO₂/sewage sludge (TS) as biomass material were synthesised via a sol–gel method. The adsorption potential of nanosized TiO₂ and TS for removal of Cd(II) was investigated in a batch system. The prepared adsorbents were characterised using X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The XRD analysis showed that pure TiO₂ is in amorphous phase before calcination and in anatase phase at annealing temperature of 400 °C. TiO₂/sewage sludge that calcined at 400 °C (TS⁴⁰⁰) was found to be the best adsorbent for cadmium removal from aqueous solution. Kinetic and isotherm studies were carried out by considering the parameters, pH, initial concentration and contact time. The optimum pH value for Cd(II) adsorption onto TS⁴⁰⁰ was found to be 6. Langmuir isotherm showed better fit than Freundlich isotherm and the maximum adsorption capacity was found to be 29.28 mg/g which is higher than that of many other adsorbents reported in literature. The sorption kinetic data were well fitted with a pseudo-second-order model. These results demonstrated that TS⁴⁰⁰ was readily prepared and is the promising and effective solid material for the removal of Cd(II) from aqueous solutions.     

Structural and mechanical properties characterization of barium strontium titanate (BST) ceramics

Ba_(1-x)Sr_(x)TiO₃ ceramics, where x?=?0.05, 0.10, 0.15, and 0.20, were prepared by solid state reaction technique. X-ray diffraction analysis confirmed the formation of single phase perovskite structures. Mechanical properties such as ultrasonic attenuation, longitudinal wave velocity, and longitudinal elastic modulus were studied by an ultrasonic pulse echo technique at 2 MHz. Investigations of ceramic microstructures and mechanical properties showed its dependence on composition and sintering time. Increasing of Sr content, x, resulted in a decrease in bulk density and ultrasonic attenuation and an increase in velocity and modulus. Also, size of crystallites and c/a ratio were found to decrease with increasing of x, and increased with increasing of sintering time. High temperature ultrasonic studies showed, in addition to Curie phase transition, two relaxation peaks and its origin was investigated. The acquired structural and mechanical results were correlated and discussed.     

Some hydrolases in human schistosomiasis with special reference to arylsulfatase B

Among many tested enzymes, lipase was found to be the one most affected by schistosomiasis in human serum, where it is increased eightfold. Arylsulfatases A and B and aspartyl protease displayed a significant decrease in the serum, while other enzymes showed a significant increase. α‐Amylase and Leucine aminopeptidase were significantly increased and arylsulfatase B showed a significant decrease. Arylsulfatase B from a patient's leucocytes did not show either changed kinetic behaviour or temperature‐dependent conformational changes. These results indicate that the diminished activity of this enzyme may be attributed to an opposing mechanism of regulation.     

Development of Cd-doped Co Nanoparticles Encapsulated in Graphite Shell as Novel Electrode Material for the Capacitive Deionization Technology

Nano-Micro Letters - Because of the low energy requirement and the environmentally safe byproducts, the capacitive deionization water desalination technology has attracted the attention of many...     

Chromatographic identification of oil and amino acid constitutents in kernels of some almond varieties

The physical and chemical properties of the oils of eight almond varieties are presented. Oils of these varieties showed similar qualitative data concerning the lipid classes separated by thin layer-chromatography. Triglycerides comprised the majority of the total lipid extract, while mono-and diglycerides were found in traces. Gas chromatographic analysis of the methyl esters of the fatty acids revealed that the unsaturated fatty acids contribute 70–90% of the total fatty acids present in the samples. The saturated acids, however, were found in a relatively low concentration (7.0–23.6%), and even a lower percentage of arachidic acid is reported. In addition to the five fatty acids identified, another five unknown acids were separated and their retention times were recorded. One of the unknowns, with a retention time of 2.45 min, is believed to be palmitoleic acid. Eleven free amino acids-were separated, identified, and quantitatively determined. Aspartate, asparagine, glutamate, and leucine have major existence. Although the presence of hydroxyproline is unusual in plant materials, it was found among the free amino acids in almond kernels.     

Effect of ultra-high molecular weight polyethylene thickness on contact mechanics in total knee replacement

One of the important design parameters in current knee joint replacements is the thickness of the ultra-high molecular weight polyethylene (UHMWPE) tibial insert, yet there is no clear definition of the upper limit of the 'thick' polyethylene insert. Using one design knee implant and subjecting it to the physiological loads encountered throughout the gait cycle, measurements of the lengths of contact imprints generated were compared with the corresponding theoretical predictions for different insert thicknesses under the same applied load. Multiple regression analysis was applied to test whether the dimensions of contact imprints are influenced by UHMWPE thickness. Good agreement was obtained between the theoretical predictions and the experimental measurements of the dimensions of contact imprints when the knee was at 60 degrees flexion. Therefore, it was possible to estimate the contact pressure at the articulating surface using the theoretical model. Contact imprint dimensions increased with increasing applied load. Statistical analysis of the experimental data revealed that, at 0 degree flexion, the overall imprint dimensions increased as the UHMWPE thickness increased from 8 to 20 mm. However, the increment was not significant when the thickness subinterval 10-15 mm was considered. Furthermore, at 60 degrees flexion, thickness was not a significant factor for the overall imprint dimensions. No evidence was found from the data to suggest that an increment in polyethylene thickness over 10 mm would significantly reduce the contact imprint dimensions. These findings suggest that thicker inserts can be avoided, as they require unnecessary bone resection.     

Removal of persistent tartrazine dye by photodegradation on TiO2 nanoparticles enhanced by immobilized calcinated sewage sludge under visible light

TiO₂ nanoparticles on calcined sewage sludge (TiO₂/sludge) were prepared by the sol-gel method and were fully characterized. The photocatalytic efficiency of TiO₂/sludge was evaluated by tartrazine dye degradation by halide lamp. TiO₂/sludge exhibited a high photocatalytic oxidation efficiency (more than 90%) of tartrazine compared with naked TiO₂ (less than 20%) due to the synergy effect of sewage sludge. The optimization of experimental conditions was 0.5 g/l TiO₂/Sludge, pH 8 with 50 mg/l tartrazine dye. The addition of sewage sludge to TiO₂ improves the efficiency of dye mineralization. The prepared catalyst showed easier separation and effective reuse.     

Dielectric properties and polarizability of molybdenum tellurite glasses

The dielectric behaviour of the [TeO₂]_1–x [MoO₃] _x , x=0.2, 0.3 and 0.45 mol%, glassy system is reported for the temperature range 300–573 K and the frequency range of 0.1–10 kHz. Both the static and high frequency dielectric constants for these binary tellurite glasses decrease with increasing MoO₃ content. The temperature dependence of the dielectric constants of these glasses are positive. The frequency dependence of the dielectric constant identifies a frequency dependence which does not show a flattening at low frequency. The room temperature static dielectric polarizability is discussed in terms of the MoO₃ concentration. The temperature dependence of the dielectric constant has been analysed in terms of the temperature changes of both volume and polarizability and also a volume change of the polarizability.