Experimental Investigation on the Performance of a Solar Still Using SiO2 Nanoparticles /Jatropha curcas L

Silicon - Now, enticing systematic civic since everywhere the world is used in green synthesis and benefit of the simple is eco-friendly with an emergent method of producing nanoparticles (NPs)....     

1-[2-(1-Cyclobutylpiperidin-4-yloxy)-6,7-dihydro-4H-thiazolo[5,4-c]pyridin-5-yl]propan-1-one: a Histamine H3 Receptor Inverse Agonist with Efficacy in Animal Models of Cognition

A series of chemical optimizations, which was guided by in vitro affinity at histamine H₃ receptor (H₃R), modulation of lipophilicity, ADME properties and preclinical efficacy resulted in the identification of 1-[2-(1-cyclobutylpiperidin-4-yloxy)-6,7-dihydro-4H-thiazolo[5,4-c]pyridin-5-yl]propan-1-one ( 45 e ) as a potent and selective (K_i=4.0 nM) H₃R inverse agonist. Dipsogenia induced by (R)-α-methylhistamine was dose dependently antagonized by 45 e , confirming its functional antagonism at H₃R. It is devoid of hERG and phospholipidosis issues. Compound 45 e has adequate oral exposures and favorable half-life in both rats and dogs. It has demonstrated high receptor occupancy (ED₈₀=0.22 mg/kg) and robust efficacy in object recognition task and, dose dependently increased acetylcholine levels in brain. The sub-therapeutic doses of 45 e in combination with donepezil significantly increased acetylcholine levels. The potent affinity, selectivity, in vivo efficacy and drug like properties together with safety, warrant for further development of this molecule for potential treatment of cognitive disorders associated with Alzheimer's disease.     

Defect-mediated optical properties of Fe-substituted TiO2 nanoparticles

Here, sol–gel derived Fe–TiO₂ anatase nanoparticles with varying concentrations of Ti_(1–x)Fe_xO₂ (x = 0%, 1%, 5%, 10%) were prepared. The structural, morphological, and optical properties of prepared samples were studied. X-ray diffraction (XRD) patterns show the formation of pure anatase phase. The mean crystallite size of Fe–TiO₂ decreases with increase in the concentration of Fe. Fourier transform infrared spectroscopy (FTIR) spectra confirmed the presence of Ti–O vibrational band for all the samples. In Raman spectrum, peak broadening and red shifting linked with Eg ∼144 cm^–1 divulge the Fe substitution at Ti sites into host lattice structure. Photoluminescence (PL) spectra verified nine peaks related to near band-edge emission and various defect states. The UV–vis diffuse reflectance spectra represent redshift and reduction in the bandgap energy. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) investigations show that the size of the grains decreases with increase in Fe doping concentration. The study shows that Fe-doped TiO₂ anatase phase nanoparticles are suitable for photocatalytic activity and solar cell applications.     

Partial replacement of carbon black with graphene in natural rubber/butadiene rubber based tire compound: Investigation of critical properties

Journal of Polymer Research - In this study, we prepared graphene oxide-based styrene/acrylic elastomeric disks (GSAE) from sugarcane bagasse/ferrocene (GO) and styrene/acrylic emulsion (SAE) to...     

Interrogating the catalytic mechanism of nanoparticle mediated Stille coupling reactions employing bio-inspired Pd nanocatalysts

To address issues concerning the global environmental and energy state, new catalytic technologies must be developed that translate ambient and efficient conditions to heavily used reactions. To achieve this, the structure/function relationship between model catalysts and individual reactions must be critically discerned to identify structural motifs responsible for the reactivity. This is especially true for nanoparticle-based systems where this level of information remains limited. Here we present evidence indicating that peptide-capped Pd nanoparticles drive Stille C-C coupling reactions via Pd atom leaching. Through a series of reaction studies, the materials are shown to be optimized for reactivity under ambient conditions where increases in temperature or catalyst concentration deactivate reactivity due to the leaching process. A quartz crystal microbalance analysis demonstrates that Pd leaching occurs during the initial oxidative addition step at the nanoparticle surface by aryl halides. Together, this suggests that peptide-based materials may be optimally suited for use as model systems to isolate structural motifs responsible for the generation of catalytically reactive materials under ambient synthetic conditions.     

Effects of mixing sequence on peroxide cured polypropylene (PP)/ethylene octene copolymer (EOC) thermoplastic vulcanizates (TPVs). Part. II. Viscoelastic characteristics

The effects of mixing sequence on the dynamic viscoelastic characteristics of peroxide cured polypropylene (PP)/ethylene octene copolymer (EOC) based TPVs were studied both in solid and melt states. When a peroxide is added to PP-EOC blends, two major competing reactions take place simultaneously: crosslinking in the EOC phase and degradation in the PP phase by ß-chain scission. Three different mixing sequences were employed. They are as follows: (a) preblending method—melt mixing of PP and EOC followed by dynamic vulcanization (b) phase mixing method—curative master batch of EOC added in molten PP and (c) split addition method—preblending procedure followed by addition of half part of PP. Solid state viscoelastic properties were studied by using dynamic mechanical thermal analysis (DMTA). Melt state viscoelastic properties were studied by dynamic strain sweep at 180 °C in Rubber Process Analyser (RPA 2000). The results indicate that both solid and melt state viscoelastic characteristics are strongly influenced by sequence of mixing. A good correlation is observed between the particle size of crosslinked EOC and the dynamic storage modulus obtained from the melt rheological experiments. Furthermore, the shortcomings of dynamic mechanical analyses in evaluating the properties of the TPVs are also critically discussed.     

Scalable synthesis of aligned carbon nanotubes bundles using green natural precursor: neem oil

Practical application of aligned carbon nanotubes (ACNTs) would have to be determined by a matter of its economical and large-scale preparation. In this study, neem oil (also named Margoaa oil, extracted from the seeds of the neem--Azadirachta indica) was used as carbon source to fabricate the bundles of ACNTs. ACNTs have been synthesized by spray pyrolysis of neem oil and ferrocene mixture at 825°C. The major components of neem oil are hydrocarbon with less amount of oxygen, which provided the precursor species in spray pyrolysis growth of CNTs. The bundles of ACNTs have been grown directly inside the quartz tube. The as-grown ACNTs have been characterized through Raman spectroscopy, scanning and transmission electron microscopic (SEM/TEM) techniques. SEM images reveal that the bundles of ACNTs are densely packed and are of several microns in length. High-resolution TEM analysis reveals these nanotubes to be multi-walled CNTs. These multi-walled CNTs were found to have inner diameter between 15 and 30 nm. It was found that present technique gives high yield with high density of bundles of ACNTs.     

A review of the antioxidant potential of medicinal plant species

Some researchers suggest that two-thirds of the world's plant species have medicinal value; in particular, many medicinal plants have great antioxidant potential. Antioxidants reduce the oxidative stress in cells and are therefore useful in the treatment of many human diseases, including cancer, cardiovascular diseases and inflammatory diseases. This paper reviews the antioxidant potential of extracts from the stems, roots, bark, leaves, fruits and seeds of several important medicinal species. Synthetic antioxidants such as butylated hydroxytoluene (BHT) and butylated hydroxylanisole (BHA) are currently used as food additives, and many plant species have similar antioxidant potentials as these synthetics. These species include Diospyros abyssinica, Pistacia lentiscus, Geranium sanguineum L., Sargentodoxa cuneata Rehd. Et Wils, Polyalthia cerasoides (Roxb.) Bedd, Crataeva nurvala Buch-Ham., Acacia auriculiformis A. Cunn, Teucrium polium L., Dracocephalum moldavica L., Urtica dioica L., Ficus microcarpa L. fil., Bidens pilosa Linn. Radiata, Leea indica, the Lamiaceae species, Uncaria tomentosa (Willd.) DC, Salvia officinalis L., Momordica Charantia L., Rheum ribes L., and Pelargonium endlicherianum. The literature reveals that these natural antioxidants represent a potentially side effect-free alternative to synthetic antioxidants in the food processing industry and for use in preventive medicine.     

Theory of quasi-reversible charge transfer admittance on finite self-affine fractal electrode

Response of an electrode under finite charge transfer rate is strongly influenced by morphological and electrochemical heterogeneity of the surface. Here, we developed a theoretical model for quasi-reversible charge transfer admittance of a random finite fractal electrode. These random heterogeneities are characterized by their roughness power spectrum. The power spectrum of the finite fractal roughness is approximated in terms of a power-law function for the intermediate wave numbers (spatial frequency components in roughness). The mathematical expression for the admittance response of a finite fractal electrode depends on diffusion length , charge transfer resistance (R_CT) and its fractal morphological characteristics. Fractals are characterized by the fractal dimension (D_H) and the surface roughness amplitude (μ), but finite fractals includes two lateral cutoff lengths. These lengths are the smallest length of roughness (?) and the lateral correlation length (L). The impedance of the electrode shows three frequency regimes, viz., (i) low frequency region, which has a classical Warburg impedance, (ii) anomalous Warburg behavior for intermediate frequency and their phase angle, ?(ω) > 45°, and (iii) high frequency impedance is controlled by charge transfer kinetics, and its phase angle follows the constraint: 0 ≤ ?(ω) < 45°. Finally, we can say that finite fractal model accounts for fractal as well as nonfractal roughnesses of the electrode, and it strongly influences the admittance response.     

Determination of Binder Decomposition Kinetics for Specifying Heating Parameters in Binder Burnout Cycles

The decomposition kinetics of poly(vinyl butyral) binder from barium titanate multilayer ceramic capacitors with platinum metal electrodes were analyzed by thermogravimetric analysis as a function of the heating rate. The activation energy and pre-exponential factor for the decomposition kinetics were determined from two types of integral equations, from the Redhead method, and from the variation in heating rate method. The accuracy of the kinetic parameters determined from these methods was then evaluated for describing the observed rate of binder decomposition. Although the individual models yielded very different kinetic parameters, all were capable of describing the experimental data within ±15% accuracy. The kinetic parameters were then used in a coupled transport and kinetic model for describing the buildup of pressure within the ceramic green body as a function of the heating cycle. A methodology based on calculus of variations was also developed to predict the minimum duration for the binder burnout cycle.