Catalytic activity of MnTUD-1 for liquid phase oxidation of ethylbenzene with tert-butyl hydroperoxide

Manganese was incorporated into silica matrix of TUD-1 using tetraethylene glycol (TEG) as the template. Three samples with Si/Mn ratio of 115, 44 and 18 were prepared and characterized by various techniques. MnTUD-1 is shown to be mesoporous with tetrahedrally coordinated Mn when Si/Mn?=?115; and nano-particles of manganese oxides are visible at higher loading of manganese (Si/Mn?=?44 and 18). The catalytic activity of MnTUD-1 was explored in the liquid-phase oxidation of ethylbenzene with tert-butylhydroperoxide (TBHP) as oxidant. Influence of various reaction parameters such as time, Si/Mn ratio, oxidant and solvent were studied. Finally the catalytic activity also compared with well-known microporous and mesoporous catalysts like MnAlPO-5, Mn containing MCM-41, MCM-48 and SBA-15.     

Unprecedented vibration damping with high values of loss modulus and loss tangent, exhibited by cement-matrix graphite network composite

This paper reports a material with unprecedented vibration damping ability, as shown by high values of both the loss tangent (vibration amplitude decay rate) and the loss modulus (energy dissipation ability, equal to the product of the storage modulus and the loss tangent) under flexure at 0.2 Hz at room temperature. The loss modulus (7.5 GPa) exceeds that of any previously reported material, including the best metal-based material, which suffers from a low loss tangent. The loss tangent (0.81) is comparable to or exceeds that of any previously reported material, including rubber, which suffers from a low loss modulus. This material is a cement-matrix graphite network composite containing 8 vol.% graphite and made by compressing a mixture of cement particles and exfoliated graphite, which binds by mechanical interlocking, followed by curing in water. The graphite network structure is supported by microscopy and the low electrical resistivity of the composite (0.04 Ω cm perpendicular to the compression direction and 0.5 Ω cm in the compression direction). The composite is much more conductive than the most conductive cement-matrix composite containing a conductive admixture. The high loss tangent is attributed to the graphite network, while the high storage modulus is attributed to the cement matrix.     

Electrical and magnetic properties of poly(<Emphasis Type="Italic">m</Emphasis>-phenylenediamine)/NiFe<Subscript>2</Subscript>O<Subscript>4</Subscript> nanocomposites

Poly(m-phenylenediamine) (PmPD)/NiFe₂O₄ nanocomposites were synthesized by in situ oxidative polymerization containing two different ratios of NiFe₂O₄ nanoparticles (10 and 20%). Dielectric studies of PmPD/NiFe₂O₄ nanocomposites were carried out at different temperature and frequency. Dielectric constants of PmPD/NiFe₂O₄ nanocomposites vary with the concentration of NiFe₂O₄ nanoparticles. Magnetic measurements of NiFe₂O₄ nanoparticles and PmPD/NiFe₂O₄ nanocomposites showed that they have ferromagnetic behaviour at room temperature. The XRD patterns of PmPD/NiFe₂O₄ nanocomposites are confirming the incorporation of NiFe₂O₄ nanoparticles into PmPD polymer. Room temperature Mössbauer spectrum of NiFe₂O₄ nanoparticles demonstrated that the Fe is in 3+ oxidation state with cubic structure. The SEM image of PmPD shows sphere like morphology. TGA suggest that thermal stability of PmPD/NiFe₂O₄ nanocomposites is greater than PmPD.     

Ketoconazole‐conjugated ZnO nanoparticles based semi‐solid formulation and study their impacts on skin disease

In this study, the ketoconazole‐conjugated zinc oxide (ZnO) nanoparticles were prepared in a single‐step approach using dextrose as an intermediate compound. The physical parameters confirmed the drug conjugation with ZnO and their size was around 70–75 nm. The drug loading and in vivo drug release studies indicated that the –CHO group from the dextrose increase the drug loading up to 65% and their release kinetics were also studied. The anti‐fungal studies indicated that the prepared nanoparticles exhibit strong anti‐fungal activity and the minimum concentration needed is 10 mg/ml. The nanoparticles loaded semi‐solid gel was prepared using carbopol, methylparaben, propyl paraben and propylene glycol. The in vitro penetration of the ketoconazole‐conjugated nanoparticles was studied using the skin. The results indicated that the semi‐solid gel preparations influenced the penetration and also favoured the accumulation into the skin membrane. The veterinary clinical studies indicated that the prepared gel is highly suitable for treatment of Malassezia.Inspec keywords: II‐VI semiconductors, skin, biomedical materials, antibacterial activity, wide band gap semiconductors, drug delivery systems, nanomedicine, drugs, diseases, gels, nanofabrication, nanoparticles, zinc compounds, biomembranes, veterinary medicineOther keywords: strong anti‐fungal activity, propyl paraben, propylene glycol, semisolid gel preparations, skin membrane, veterinary clinical studies, semisolid formulation, skin disease, ketoconazole‐conjugated zinc oxide nanoparticles, single‐step approach, physical parameters, drug conjugation, drug loading, release kinetics, dextrose, in vivo drug release studies, carbopol, methylparaben, in vitro penetration, Malassezia, ZnO     

Effect of deposition time on optical, structural and photoluminescence properties of Cd0.6Co0.4S thin films by chemical bath deposition method

Cd_0.6Co_0.4S thin films have been deposited successfully on glass plates using chemical bath deposition method at 80° C by changing the time of deposition as a controlling parameter from 10 to 30 h. X-ray diffraction measurement shows the Co substitution of cadmium sulphide (CdS) system with hexagonal structure having the average crystalline between 1.79 and 2.13 nm. Energy dispersive X-ray spectrum reveals the presence of Co in the Cd–S lattice. The change in lattice parameters is demonstrated by the crystal size, bond length, micro-strain and the quantum confinement effect. The band gap energy is varied from 2.44 to 2.66 eV by changing the deposition times from 10 to 30 h which is useful to design a suitable window material in fabrication for solar cells. The presence of functional groups and the chemical bonding is confirmed by Fourier transform infrared spectra. The presence and the major blue shift of strong blue and red bands were demonstrated by photoluminescence spectra. The intensive emission properties of the Cd_0.6Co_0.4S thin films show a great potential for use as nano-scaled optoelectronic intensive light emitters under different deposition time.     

Effect of formulated zimmu (Allium cepa L. × Allium sativum L.) extract in the management of grain mold of sorghum

BACKGROUND: The in vitro antifungal activity of zimmu (Allium cepa L. × Allium sativum L.) extract against Aspergillus flavus Link., Fusarium moniliforme Sheld, Curvularia lunata (Wakker) Boedijn and Alternaria alternata (Fr.) Keissler, the fungi associated with grain mold of sorghum, was evaluated. An emulsifiable concentrate (EC) formulation of zimmu extract was prepared and its efficacy in controlling grain mold was tested under field conditions. RESULTS: The leaf extract of zimmu exhibited strong antifungal activity against A. flavus, F. moniliforme, C. lunata and A. alternata and caused in vitro fungal growth inhibition of 73.3%, 71.1%, 70.0% and 74.4%, respectively. Foliar application of zimmu formulation 50 EC at 3 mLL^?1 (v/v) concentration 60, 75 and 90 days after sowing significantly reduced the incidence of grain mold and increased the grain weight and grain hardness. A significant reduction in the aflatoxin B1 content in sorghum grains was observed when sorghum plants were sprayed with zimmu formulation 50 EC at 0.3% concentration. Western blot analysis revealed that a thaumatin‐like protein (TLP) a molecular mass of 23 kDa that cross‐reacted with zeamatin antiserum was expressed at higher levels in sorghum grains after treatment with zimmu formulations. CONCLUSION: The leaf extract of zimmu exhibited antifungal activity against sorghum grain mold fungi. The formulated zimmu extract was significantly effective in reducing the grain mold incidence in sorghum under field conditions. This formulated zimmu extract offers a novel alternative for eco‐friendly management of grain mold of sorghum. Copyright © 2007 Society of Chemical Industry     

Studies on antimicrobial and wound healing applications of gauze coated with CHX–Ag hybrid NPs

In this study, chlorhexidine (CHX)–silver (Ag) hybrid nanoparticles (NPs) coated gauze was developed, and their bactericidal effect and in vivo wound healing capacities were tested. A new method was developed to synthesise the NPs, wherein Ag nitrate mixed with sodium (Na) metaphosphate and reduced using Na borohydride. Finally, CHX digluconate was added to form the hybrid NPs. To study the antibacterial efficacy of particles, the minimal inhibition concentration and biofilm degradation capacity against Gram‐positive and Gram‐negative bacteria was studied using Escherichia coli and Staphylococcus aureus. The results indicated that the NP inhibited biofilm formation and was bactericidal as well. The gauze was doped with NPs, and its wound healing property was evaluated using mice model. Results indicated that the wound healing process was fastened by using the NPs gauze doped with NPs without the administration of antibiotics.Inspec keywords: nanomedicine, nanoparticles, wounds, silver, cellular biophysics, biomedical materials, nanofabrication, microorganisms, antibacterial activityOther keywords: NPs gauze, antimicrobial wound healing applications, hybrid NPs, chlorhexidine–silver hybrid nanoparticles, CHX, coated gauze, bactericidal effect, minimal inhibition concentration, biofilm degradation capacity, Gram‐negative bacteria, wound healing property, wound healing process, in vivo wound healing capacities, Staphylococcus aureus, Escherichia coli, antibiotics administration, Na borohydride, Ag nitrate mixing, sodium metaphosphate, CHX digluconate, NP inhibited biofilm formation, Ag     

Synthesis and properties of polytriazoleimide containing anthracene,pyridine and 1, 2, 3‐triazole groups and their nanocomposites with titanium dioxide

A novel anthracene, pyridine and 1, 2, 3‐triazole containing diamine was synthesized by copper catalyst 1, 3‐dipolar cycloaddition of azides and alkynes groups (Click reaction). A series of polytriazoleimide (PTAI) nanocomposites were successfully prepared by condensation polymerization between the synthesized diamine monomer and commercially available pyromellitic dianhydride with different weight percentage of titanium dioxide (TiO₂). The structure of the monomer and polymer were confirmed by the fourier transform infrared and nuclear magnetic resonance spectroscopy. The synthesized PTAI is readily soluble in common polar solvents. The PTAIs naocomposites exhibited high thermal stability, the temperature corresponding to a 5% weight loss in the range of 495°C–555°C, excellent flame retardancy (char yield were found to be in the range of 48.1–66.4) and high glass transition temperature (T_g) at (267°C–294°C). Furthermore incorporation of TiO₂ into the PTAI matrix significantly improve the dielectric constant (2.70–4.75 at 1MHz) and dielectric loss (0.06–0.46 at 1 MHz). POLYM. ENG. SCI., 59:129–138, 2019. © 2018 Society of Plastics Engineers     

Causality between energy consumption and output growth in the Indian cement industry: An application of the panel vector error correction model (VECM)

The aim of this paper is to examine the existence and direction of the causal relationship between energy consumption and output growth in the Indian cement industry for the period 1979–80 to 2004–05. The most recently developed panel unit root, a heterogeneous panel cointegration and panel-based error correction model, is applied within a multivariate framework. The empirical results confirm a positive, long-run cointegrated relationship between output and energy consumption when heterogeneous state effects are taken into account. We also found a long-run, bi-directional relationship between energy consumption and output growth in the Indian cement industry for the study period, implying that an increase in energy consumption directly affects the growth of this sector and that growth stimulates further energy consumption. These empirical findings imply that energy consumption and output are jointly determined and affect each other. The empirical evidence also suggests the implementation of energy conservation policies oriented toward improving energy-use efficiency to avoid any negative impacts of the conservation policies on the growth of this industry.     

A performance comparison of trained multilayer perceptrons andtrained classification trees

The important differences between multilayer perceptrons and classification trees are considered. A number of empirical tests on three real-world problems in power-system load forecasting, power-system security prediction, and speaker-independent vowel recognition are presented. The load-forecasting problem, which is partially a regression problem, uses past trends to predict the critical needs of future power generation. The power-security problem uses the classifier as an interpolator of previously known states of the system. The vowel-recognition problem is representative of the difficulties in automatic speech recognition caused by variability across speakers and phonetic context. In all cases even with various sizes of training sets, the multilayer perceptron performed as well as or better than the trained classification trees. It is therefore concluded that there is not enough theoretical basis to demonstrate clear-cut superiority of one technique over the other