Fibrous spherical Ni-M/ZSM-5 (M: Mg,Ca, Ta,Ga) catalysts for methane dry reforming: The interplay between surface acidity-basicity and coking resistance

A highly active and robust fibrous spherical ZSM-5-supported nickel catalyst with different promoters (Mg, Ca, Ta, Ga) have been synthesised by microemulsion method for dry reforming of methane (DRM). The structural framework provided by the unique fibrous spherical ZSM-5 aided confinement of Ni particles. Catalytic activity was improved by homogenous distribution of surface acid-basic sites, thereby reducing the propensity of coke deposition. Bimetallic Ni-Ta catalyst produced the highest CH₄ and CO₂ conversions at 93% and 98%, respectively, with H₂/CO ratio closer to unity (0.97). The nature of acid sites and bimetallic Ni-Ta synergism amplified interaction of catalyst components, resulting in improved interaction with the reactants, thus impeding metal sintering and coke deposition. Consequently, the Ni-Ta/FZSM-5 catalyst shows long-term activity (80 hours) for the DRM reaction at 800°C.     

Removal of Congo Red from Aqueous Solutions by Spent Black Tea as Adsorbent

Herein we present spent black tea as an adsorbent for the removal of Congo red dye from aqueous solutions. The effects of various parameters such as pH, time, temperature, adsorbent dosage and adsorbate dosage on dye adsorption were investigated. Batch experiments were conducted using different amount of adsorbent material (2.5–1000 mg) at varying amounts of adsorbate (5–500 mg/L) at 35°C and different pH (1–13). A maximum dye removal of >80% was achieved with an adsorbent dose of 100 mg, adsorbate concentration of 5 mg/L under pH range of 6 within 5 min at room temperature. The experimental data were modeled by Langmuir, Freundlich and Temkin isotherms and conforms to both Langmuir and Freundlich isotherms but not to Temkin isotherm. The proposed spent black tea can be effectively used as a low cost adsorbent for the removal of Congo red dye.     

A review of retinal blood vessels extraction techniques: challenges,taxonomy, and future trends

Pattern Analysis and Applications - The visual exploration of retinal blood vessels assists ophthalmologists in the diagnoses of different abnormalities of the eyes such as diabetic retinopathy,...     

LiFi cross-connection node model using whispering gallery mode of light in a microring resonator

Microsystem Technologies - A free space cross-connection of the optical signals using an optical micro/nano-electro-mechanical system(OMEMS/ONEMS) is designed and simulated using the commercial...     

A diagnostic prediction model for chronic kidney disease in internet of things platform

Multimedia Tools and Applications - Chronic Kidney Disease (CKD) is being typically observed as a health threatening issue, especially in developing countries, where receiving proper treatments are...     

Tailoring the Silica Amount in Stabilizing the Tetragonal Phase of Zirconia for Enhanced Photodegradation of 2-Chlorophenol

Topics in Catalysis - A simple microwave method was employed to prepare silica-doped mesoporous zirconia nanoparticles, SiO2/ZrO2 (SiZr) catalysts under various Si amount and then characterized by...     

Rutin Modulates MAPK Pathway Differently from Quercetin in Angiotensin II-Induced H9c2 Cardiomyocyte Hypertrophy

Rutin is a flavonoid with antioxidant property. It has been shown to exert cardioprotection against cardiomyocyte hypertrophy. However, studies regarding its antihypertrophic property are still lacking, whether it demonstrates similar antihypertrophic effect to its metabolite, quercetin. Hence, this study aimed to investigate the effects of both flavonoids on oxidative stress and mitogen-activated protein kinase (MAPK) pathway in H9c2 cardiomyocytes that were exposed to angiotensin II (Ang II) to induce hypertrophy. Cardiomyocytes were exposed to Ang II (600 nM) with or without quercetin (331 μM) or rutin (50 μM) for 24 h. A group given vehicle served as the control. The concentration of the flavonoids was chosen based on the reported effective concentration to reduce cell hypertrophy or cardiac injury in H9c2 cells. Exposure to Ang II increased cell surface area, intracellular superoxide anion level, NADPH oxidase and inducible nitric oxide synthase activities, and reduced cellular superoxide dismutase activity and nitrite level, which were similarly reversed by both rutin and quercetin. Rutin had no significant effects on phosphorylated proteins of extracellular signal-related kinases (ERK1/2) and p38 but downregulated phosphorylated c-Jun N-terminal kinases (JNK1/2), which were induced by Ang II. Quercetin, on the other hand, had significantly downregulated the phosphorylated proteins of ERK1/2, p38, and JNK1/2. The quercetin inhibitory effect on JNK1/2 was stronger than the rutin. In conclusion, both flavonoids afford similar protective effects against Ang II-induced cardiomyocyte hypertrophy, but they differently modulate MAPK pathway.     

Dynamic viscoelastic behavior of polypropylene/polybutene-1 blends and its correlation with morphology

In this study the rheology, morphology, and interfacial interaction of polypropylene (PP)/polybutene-1 (PB-1) blends in different percentages of PB-1 are investigated. The morphology of cryo-fractured surfaces of samples was studied by scanning electron microscopy (SEM). The SEM images showed a droplet-matrix structure in all range of compositions and the size of dispersed phase increased proportionally with PB-1 content. The miscibility of blends at various compositions is evaluated by viscoelastic parameters determined by dynamic oscillation rheometry in the linear viscoelastic region. A distinct Newtonian plateau at low frequencies is observed and the variations of complex viscosity (η*) against angular frequency (ω) for all blends are in agreement with Cross model. The complex viscosity of samples at various percentages of PB-1 showed the log-additivity mixing rule behavior in low frequencies and positive-negative deviation behavior (PNDB) at high shear rates. The phenomena such as decrease in the sensitivity of storage modulus to shear rate in the terminal region, the deviation of Cole–Cole plots from the semi-circular shape, and the tail in relaxation spectrums at high relaxation times are the evidences of two phase heterogenous morphology. The effect of time–temperature on the phase behavior is studied and the interfacial tension between matrix and dispersed phase was evaluated by using emulsion theoretical models. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effect of Viscosity Increasing Agent and Electrolyte Concentration on the Release Rate of Theophylline from a HPMC Based Sustained Release Capsules

Sustained release (SR) granules (250-650∼) containing theophylline were prepared using hydroxypropyl methylcellulose (HPMC) as a rate retarding polymer. The effect of variable ionic strength and viscosity increasing agent on the theophylline release rate have been investigated. Irrespective of dissolution media the theophylline release kinetics was found to be dependent on square root of time. Thc Higuchian release rate (K) was found to increase exponentially with the increase in ionic strength of the dissolution fluid. An opposite effect was observed with the viscosity increasing agent sodium carboxy methyl cellulose (Na-CMC) in the dissolution fluid. The release rate dccreased linearly with the increase of Na-CMC concentration in the dissolution fluid.