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[3+2] regioselective annulation reaction of 2-arylidene-1,3-indandiones towards synthesis of spirocyclopentenes: understanding the mechanism of γ-attack vs. α-attack using DFT …
No full textA regioselective [3+2] cyclisation reaction between 2-arylidene-1,3-indanedione and ethyl 2,3-butadienoate catalysed by triphenylphosphine has been demonstrated to synthesize functionalised spirocyclic cyclopentenes. The reaction tolerated various electron-rich and electron-deficient arylsubstituted 2-arylidene-1,3-indanediones with high to excellent chemical yields (up to 99%) and moderate to good regioselectivity (up to 5 : 1). DFT studies have also been carried out to understand the
regioselective nature of this reaction. The results of Frontier molecular orbital calculations and the activation energy (Ea) favour the formation of compound 3a via g-attack compared to that of 4a via a�attack
Development of Banana/Coir Natural Fibers Reinforced Polypropylene Hybrid Composites: The Effect of MA-g-PP (Maleic Anhydride Grafted Polypropylene) on Mechanical Properties and Thermal properties
No full textBanana/Coir fiber reinforced polypropylene hybrid composites was formulated by using twin screw extruder and injection molding machine. Specimens were prepared untreated and treated B/C Hybrid composites with 4% and 8% of MA-g-PP to increase its compatibility with the polypropylene matrix. Both the without MA-g-PP and with MA-g-PP B/C hybrid composites was utilized and three levels of B/C fiber loadings 15/5, 10/10 and 5/15 % were used during manufacturing of B/C reinforced polypropylene hybrid composites. In this work mechanical
performance (tensile, flexural and impact strengths) of untreated and treated (coupling agent) with 4% and 8% of MA-g-PP B/C fibers reinforced polypropylene hybrid composite have been investigated. Treated with MA-g-PP B/C fibers reinforced specimens explored better mechanical properties compared to untreated B/C fibers reinforced polypropylene hybrid composites. Mechanical tests represent that tensile, flexural and impact strength increases with increase in concentration of coupling agent compared to without coupling agent MA-g-PP hybrid composites. B/C fibers reinforced polymer composites exhibited higher tensile, flexural and impact strength at
5% of Banana fiber, 15% of Coir fiber in the presence of 8% of MA-g-PP compared to 4% of MAg-PP and untreated hybrid composites. The percentage of water absorption in the B/C fibers reinforced polypropylene hybrid composites resisted due to the presence of coupling agent MA-gPP and hermogravimetry analysis (TGA) also has done
Removal of lead from aqueous solution using chemically modified green algae as biosorbent: optimization and kinetics study
No full textThe present research aims to elucidate the effect of lactic acid concentration on the extractability and physicochemical properties of cobia (Rachycentron canadum) skincollagen. The cobia skin acid-soluble collagen (ASC) was isolated using different con- centrations of lactic acid (0.5 M and 1.0 M) and characterized on its extractability and physicochemical properties. The extract using 0.5 M lactic acid gives a higher
yield compared to using 1.0 M lactic acid. The moisture, protein, fat, and ash con-tent of cobia skin ASC extracted using 0.5 M was higher than extracted using1.0 M lactic acid. The functional group present in both extracts was amide A, amide I, and
amide III. Both extracts at different lactic acid concentrations showed decreasing on relative viscosity with temperature increased. Thus, different extractability and physicochemical properties of cobia skin ASC extracts exhibits based on the lactic
acid concentration and it would produce collagen with multi potential application
Coumarin-chalcone hybrids targeting insulin receptor: Design, synthesis, anti-diabetic activity, and molecular docking
Get PDFFour series of thirteen new coumarin-chalcone hybrids (DPCU 1–13, DPCT 1–13, DCCU 1–13 and DCCT 1–13) were designed and synthesized using Biginelli synthesis, Pechmann condensation, Acetylation, and ClaisenSchmidt reactions. Synthesized compounds were tested for insulin receptor in silico docking studies (PDB ID:1IR3); DCCU 13 and DCCT 13 derivatives received the lowest docking score; Streptozocin (STZ) and Nicotinamide (NA) induced type II diabetes was tested for their anti-diabetic activity in rats. In vivo tests suggested that fasting blood glucose levels of animals treated with DCCU 13 (30 mg/kg body weight) and DCCT 13 (30 mg/kg body weight) were significantly and moderately suppressed, respectively, relative to fasting blood
glucose levels of diabetic control animals. Similarly, therapy with DCCU 13 and DCCT 13 attenuated oxidative stress parameters such as lipid peroxidation (MDA), superoxide dismutase (SOD) and increased the glutathione (GSH) in the liver and pancreas in a dose-dependent manner. In comparison, therapy with DCCU 13 (30 mg/kg body weight) mitigated alterations in the histological architecture of the liver and pancreatic tissue. These results indicated that the hybrids DUUC 13 and DCCT 13 at 30 mg/kg had an anti-hyperglycemic and antioxidant impact on STZ + NA mediated type II diabetes in rats. Further detailed work could be required to determine the precise mode of action of the anti-diabetic behavior of hybrids
Eco-Friendly Sustainable Poly(benzoxazine-co-urethane) with Room-Temperature-Assisted Self-Healing Based on Supramolecular Interactions
Get PDFABSTRACT: This work is an attempt to develop bio-based eco�friendly poly(benzoxazine-co-urethane) [poly(U-co-CDL-aee)]
materials using cardanol-based benzoxazines (CDL) and hexam�ethylene diisocyanate (HMDI) to check their self-healing ability and thermal properties. CDL monomers were synthesized using cardanol, amino ethoxyethanol (aee) or 3-aminopropanol (3-ap), and paraformaldehyde through the Mannich reaction. Later, CDL�aee or CDL-3-ap monomers were copolymerized with a urethane precursor (HMDI), followed by ring-opening polymerization
through thermal curing. The thermal properties of poly(U-co�CDL) were evaluated by differential scanning calorimetry (DSC)
and thermogravimetric analysis (TGA). The self-healing behavior
of the bio-based poly(U-co-CDL) was checked by applying a mild
external pressure. The results revealed that the developed poly(U-co-CDL) showed repeatable self-healing ability due to
supramolecular hydrogen-bonding interactions. Further, the self-healing ability of poly(U-co-CDL) was studied using density
functional theory (DFT). From the above results, the developed material with superior self-healing ability can be used in the form of
self-healing coatings and composites for various applications with extended shelf-life and reliabilit
Stereoselective synthesis of (-)-Tetrahydropyrenophorol
No full textAbstract: Tetrahydropyrenophorol, an interesting macrodiolide was isolated from the plant Fagonia cretica. The total synthesis of (-)-1-tetrahydropyrenophorol was achieved in an elegant and linear manner from readily accessible racemic epoxide. The archetypal reactions include regioselective opening of epoxide,
Sharpless asymmetric dihydroxylation, and Mitsunobu cyclodimerization to construct the requisite 16-membered bis-lactone. The synthetic approach demonstrated here is very simple and can be used for the syntheses of related compounds an economic and highly stereoselective wa
Synthesis and structural characterization of the formato bridged Cu( ii ) cubane: Crystallographic evidence of atmospheric CO 2 fixation as formate in a tertranuclear Cu(II) cluster
No full textABSTRACT
Flexible electronic devices entail highly transparent and conducting electrodes with excellent adherent and mechanically robust properties along with excellent
bendability. Here, we report the development of transparent and conducting electrodes comprising silver nanowires (AgNWs) and amorphous-titanium oxide (a-TiOx) nanocomposite thin films. The AgNWs and a-TiOx nanocom�posite thin films were deposited by a wire bar coating process, a scalable and
high throughput procedure. PXRD analysis confirmed the crystalline and amorphous nature for AgNWs and TiOx thin film, respectively. FE-SEM and HRTEM analyses revealed the core–shell nature of the composite where AgNWs and a-TiOx acted as core and shell, respectively. Even after three-layer coating of
AgNWs-a-TiOx nanocomposite thin films, high transparency (* 77%) in the visible region (400–800 nm) and a sheet resistance of 23 X/sq were observed. Furthermore, tape peel off tests were conducted for AgNWs and AgNWs-a-TiOx nanocomposite, which displayed high adherence for the three-layer coated
AgNWs-a-TiOx nanocomposite as compared with AgNWs alone. The formation of AgNWs-a-TiOx core–shell structure enhances the intra-particle binding and network formation of AgNWs. The preliminary studies highlight that the developed AgNWs-a-TiOx nanocomposite thin films have great potential as transparent electrodes for realizing scalable cost-effective flexible electronic
device
Efficiency and economic optimization of shell and tube heat exchanger using bacteria foraging algorithm
No full textShell and tube heat exchanger (STHE) is widely used in the industries for various purposes due to its capacity to with�stand pressure. STHE has the drawback of more cost and lower efciency. Many existing methods involve in applying the
optimization technique to decrease the cost of the system. Existing method has the lower efciency in the optimization
due to the random initialization and poor convergence. This research applies the bacteria foraging algorithm (BFA) to
increase the efciency and decrease the cost of the STHE system. The BFA has the advantages of the faster convergence
and the global search approach to increase the performance in design. The proposed BFA is evaluated in the two case
studies and compared with the existing method. The proposed BFA in multi-objective optimization of STHE has the total
cost of 41,464 €, while existing method has the total cost of 41,913 €. The proposed BFA method also achieved high heat
efciency coefcient of 1089, and the existing method has 1031.47
Comparative performance and emission studies of the CI engine with Nodularia Spumigena microalgae biodiesel versus different vegetable oil derived biodiesel
No full textBiodiesel is a renewable diesel fuel that can be burned in any unmodifed diesel engine at any concentration. Biodiesel
from Nodularia Spumigena microalgae produced by transesterifcation is used in the present study. Methyl esters of
algae have been prepared after successful extraction of biomass in an open pond cultivation system. Biodiesel was
blended with diesel fuel with the volumetric ratios of 10% (A10) and 20% (A20). The experiments were conducted on a
constant speed (1500 rpm), 4-stroke diesel engine ftted with diesel particulate flter (DPF) at a fuel injection pressure
of 180 bar. Methyl esters of Karanja oil, Rice Bran oil, and Castor oil were also tested in the same engine for comparison.
BSFC values increased with increase in Biodiesel blend percentage in diesel. However, K20 and A20 showed fuel economy by 5.51% and 10.06% in comparison to diesel. The emissions of CO and HC with fuel A20 are decreased by 65.77% and 53.33% respectively. The NOx emission showed an increasing trend with the blending of algae methyl esters in diesel. The presence of DPF is credited for signifcant reduction of PM emissions. The results predicted that the usage of algae
blends could be supported, although there is a slight reduction in engine performance and an increase in NOx emissions
Mechanical and thermal characterization of chickenRaches/sawdust reinforced hdpe hybrid composites
No full textThis project emphasized on the wastage which can be recycled and gives a better product which can stop spoiling the
environment. In our country, there are so many different types of waste products, which will come from different
categories like factories, farms and houses. Among them two fibers such as neem saw dust, chicken feather rachis and
HDPE granules are chosen. These materials are combined to prepare granules by using single screw extruder and
strand pelletizer machines so that 7 compositions with different ratios are prepared using those granules. They are 80H10CF-10SD, 80H-5CF-15SD, 80H-15CF-5SD, 80H:20CF, 70H:30CF,70H:30SD and 80H:20SD. For those samples
Mechanical Properties using MFI and Specific Gravity tests, thermal properties using TGA and DSC tests and Optical
properties using FTIR testings for all samples will be determined. The above ratio samples are having better mechanical, thermal and optical characteristics when compared to individual fibre materials