Structural,optical and electrical properties of Ce0.8Sm0.2-xErxO2-δ (x = 0–0.2) Co-doped ceria electrolytes

This study examined the effects of samarium and erbium co-doping on the structural, optical, and electrical properties of ceria (CeO₂). Ceramic (Ce_0.8Sm_0.2-xEr_xO_2-δ; x?=?0, 0.05, 0.10, 0.15, 0.20) electrolytes were synthesized via sol-gel assisted citric acid–nitrate combustion and calcined at 850?°C for 5?h. The calcined electrolytes possessed a cubic fluorite crystal structure without impure phases. The direct band gap of the calcined electrolytes increased as the erbium content increased and the lowest band gap was obtained for Ce_0.8Sm_0.2O_2-δ (SDC) electrolyte. The calcined electrolyte powders were subsequently pressed into cylindrical pellets by uniaxial die pressing, and the pellets were sintered at 1400?°C for 5?h. The sintered densities of the pellets were measured with Archimedes’ method. The relative density of Ce_0.8Sm_0.1Er_0.1O_2-δ co-doped ceria electrolyte was higher than those of singly doped ones, and these findings were further confirmed through field emission scanning electron microscopy. Electrochemical impedance spectroscopy indicated that the conductivity of erbium-doped ceria increased as the samarium content increased. The maximum total ionic conductivity was observed in Ce_0.8Sm_0.1Er_0.1O_2-δ co-doped electrolyte. However, the singly doped SDC electrolyte exhibited the highest ionic conductivity of 13.12 mS/cm and the lowest activation energy of 0.580?eV at 600?°C among all other Ce_0.8Sm_0.2-xEr_xO_2-δ co-doped ceria electrolytes.     

Vascular endothelial growth factor: An important molecular target of curcumin

The discovery of Vascular Endothelial Growth Factor (VEGF), the key modulator of angiogenesis, has triggered intensive research on anti-angiogenic therapeutic modalities. Although several clinical studies have validated anti-VEGF therapeutics, with few of them approved by the U.S. Food and Drug Administration (FDA), anti-angiogenic therapy is still in its infancy. Phytochemicals are compounds that have several metabolic and health benefits. Curcumin, the yellow pigment derived from turmeric (Curcuma longa L.) rhizomes, has a wide range of pharmaceutical properties. It has also been shown to inhibit VEGF by several studies. In this review, we elaborate the effect of curcumin on VEGF and angiogenesis and its therapeutic application.     

Immune modulation by curcumin: The role of interleukin-10

Cytokines are small secreted proteins released by different types of cells with specific effects on cellular signaling and communication via binding to their receptors on the cell surface. IL-10 is known to be a pleiotropic and potent anti-inflammatory and immunosuppressive cytokine that is produced by both innate and adaptive immunity cells including dendritic cells, macrophages, mast cells, natural killer cells, eosinophils, neutrophils, B cells, CD8⁺ T cells, and T_H1, T_H2, and T_H17 and regulatory T cells. Both direct and indirect activation of the stress axis promotes IL-10 secretion. IL-10 deregulation plays a role in the development of a large number of inflammatory diseases such as neuropathic pain, Parkinson's disease, Alzheimer's disease, osteoarthritis, rheumatoid arthritis, psoriasis, systemic lupus erythematosus, type 1 diabetes, inflammatory bowel disease, and allergy. Curcumin is a natural anti-inflammatory compound able to induce the expression and production of IL-10 and enhancing its action on a large number of tissues. In vitro and in pre-clinical models curcumin is able to modulate the disease pathophysiology of conditions such as pain and neurodegenerative diseases, bowel inflammation, and allergy, but also of infections and cancer through its effect on IL-10 secretion. In humans, at least one part of the positive effects of curcumin on health could be related to its ability to enhance IL-10 -mediated effects.     

Reuse of glass waste in the manufacture of ceramic tableware glazes

Today, various studies are carried out to spread the understanding of sustainability. The sustainability of production processes gains importance in corporate areas. In this study, the use of glass waste instead of frit used in glaze compositions in the ceramic industry was evaluated. The chemical and physical properties of glass wastes on samples were examined. The glaze formulations were prepared using 3%, 5%, and 8% by weight of glass waste instead of frit. Glass wastes were added to glaze compositions and 12 different glaze formulation studies were carried out. Transparent, Opaque, and Matte test glazes were prepared with glass waste added glaze formulations, and these glazes were applied to ceramic bodies. SEM (scanning electron microscope) analysis of standard glaze and glass waste added glazes was performed to determine the microstructural and morphological characterizations. Also, surface whiteness, brightness, L*a*b values, glaze flows, harcort test results, and final water absorption values were compared. As a result of the studies, it has been determined that it is appropriate to use 3% glass waste by weight instead of the frit in the production of ceramic tableware.     

A New Energy-Aware Cluster Head Selection Algorithm for Wireless Sensor Networks

Wireless Personal Communications - Wireless Sensor Networks (WSN) always need energy due to the areas they are used. The use of sensors is quite wide, and in some of the places, it is very...     

Integrated acoustic echo and noise suppression in modulation domain

The quality of speech transmission in mobile communication systems deteriorates due to the presence of background noise and acoustic echo. The background noises are the disturbances from the surroundings and acoustic echo is induced due to the reverberation of loudspeaker signal in the near end environment. In conventional acoustic echo suppression setup, the echo path effect is modelled either in time or in frequency domain, and to cancel the echo, a replica of the echo is created by estimating the echo path response adaptively in the corresponding domain. Recently, the modulation domain analysis, which captures the human perceptual properties, is widely being used in speech processing. Modulation domain conveys the temporal variation of the acoustic magnitude spectra which acts as an information bearing signal. In this work, a novel integrated system for acoustic echo and noise suppression in the modulation domain is developed. So far, no work in this context in modulation domain has been found as reported. An efficient method for modelling the echo path and estimating the echo in the modulation domain is introduced and implemented. The effects of echo and noise are suppressed using the modulation spectral manipulation and the performance of the proposed system is found to be better than other conventional integrated systems.     

THE EFFECT OF MATTALOPORHYRINS ON ASPHALT OXIDATION. II. THE EFFECT OF VANADYL CHELATES FOUND IN PETROLEUM

ABSTRACT

Four selected asphalts were blended with zero to five wt. percent of fractions rich in vamady cheltes prepared from two crude oils. The mixture was -coated in a teflon -support, and the whole was heated in an oven at. 113±2°C for 24 hours. The mixture then was analyzed for increases ketone, acid and anhydride functions.

in general, functions rich in vanady ponphyrims tended to promote asphalt oxidation, particularly as measured by increase in kentones. Corelation of vanadyl ponphyrim concentration with asphalt oxidation is observed to the direct only if asphalts are mixed with varying amounts of the same fraction derived from the same crude Possible reasons for this phenomenon are discussed in terms of oxidation susceptibility of aspha1ts, the importance of molecular associations, and the relative catalytic activities of metallaporphyrins and other metal chelates