Palladium‐nanoparticle intercalated vermiculite for selective hydrogenation of α,β‐unsaturated aldehydes

Palladium nanoparticles were generated in the interlamellar region of swelling 2:1 type vermiculite clay using an adsorption excess isotherm. An adsorption excess isotherm was constructed for vermiculite after exchanging the exchangeable Na⁺ ions in the interlamellar region using a binary liquid mixture (ethanol:toluene). Based on adsorption excess isotherm, 1% w/w palladium was intercalated into the interlamellar space of vermiculite. The Pd‐intercalated vermiculite was characterized by X‐ray diffraction, transmission electron microscopy and atomic absorption spectroscopy. The 1% w/w Pd‐intercalated vermiculite was tested for its catalytic activity towards selective hydrogenation reactions involving some α,β‐unsaturated carbonyl compounds using a pulse reactor and its catalytic activity was compared with commercial 1% Pd/C. The intercalated catalyst was found to be very selective towards the desired product of unsaturated alcohols. Copyright © 2007 Society of Chemical Industry     

Tracing enteric viruses in the European berry fruit supply chain

In recent years, numerous foodborne outbreaks due to consumption of berry fruit contaminated by human enteric viruses have been reported. This European multinational study investigated possible contamination routes by monitoring the entire food chain for a panel of human and animal enteric viruses.     

Characterization of UHF RFID tags fabricated directly on convex surfaces by pad printing

The possibility of pad printing in RFID tag antenna manufacturing is investigated. Passive UHF RFID tags were printed on flat and on convex surfaces with two different polymer thick-film silver inks. The effect of the ink and substrate material properties on tag antenna performance was examined. The goal was to provide information which is needed in adapting the pad-printing technique in RFID tag manufacture. The results show that pad printing is suitable for tag manufacturing on flat and on convex surfaces. The curvature of the substrate did not significantly affect the tag performance. It was more important to take into consideration other substrate properties, ink characteristics, morphology, and printing parameters. The best practice is to take these matters into consideration in the initial tag design process to ensure proper tag performance at the desired frequency.     

Magneto-transport properties of Fe-doped LSMO manganites

Magneto-transport measurements have been performed on La_0.67Sr_0.33Mn_1−xFe_xO₃ (x = 0.0, 0.05 and 0.07) manganites synthesized by solid state route. The overall nature of AC susceptibility is found to be frequency independent. With the substitution of Mn by Fe, the transport properties dramatically change suppressing the double-exchange interaction. This in turn weakens the ferromagnetism and consequently decreases the paramagnetic to ferromagnetic transition temperature (T_c). However, DC electrical resistivity of the samples show board hump at metal-insulator transition temperature (T_MI) in contrary with sharp transition at T_c and T_MI < T_c indicating decoupling of electrical and magnetic properties. Resistivity behavior of these samples can be well explained by the consideration of bond percolation model which is basically developed from effective approximation method.     

Apatite formability of boron nitride nanotubes

This study investigates the ability of boron nitride nanotubes (BNNTs) to induce apatite formation in a simulated body fluid environment for a period of 7, 14 and 28 days. BNNTs, when soaked in the simulated body fluid, are found to induce hydroxyapatite (HA) precipitation on their surface. The precipitation process has an initial incubation period of ～ 4.6 days. The amount of HA precipitate increases gradually with the soaking time. High resolution TEM results indicated a hexagonal crystal structure of HA needles. No specific crystallographic orientation relationship is observed between BNNT and HA, which is due to the presence of a thin amorphous HA layer on the BNNT surface that disturbs a definite orientation relationship.     

Microstructural evolution and fracture toughness of plasma sprayed CNT reinforced Yttria-stabilized Hafnia coating

Yttria (8 wt%)-stabilized hafnia (YSH) and carbon nanotubes (CNTs) (1 wt%) reinforced yttria-stabilized hafnia (YSHC) coatings were fabricated on alumina substrate using atmospheric plasma spray technique. Raman spectra confirmed the survival of CNTs in plasma sprayed YSHC coating and indicated about graphitization of CNTs. Whereas, the FE-SEM micrograph infers the presence of few 2-D graphene platelet-like structure in plasma sprayed YSHC coating. Addition of 1 wt% CNTs has significantly increased the densification of YSH coating from 86% to 92%, whereas average hardness and elastic modulus increased by ~57% and ~16%, respectively. A phenomenal increase of ~125% in relative fracture toughness was observed in YSHC coating, which is attributed to three major factors viz. (a) Enhanced densification (b) High fraction of fully melted regions and (c) Various toughening mechanisms, like CNTs pull out, CNTs braiding, graphene splat wrapping, CNTs anchoring.     

Comprehensive studies on polyethylenimine filled polypropylene and its potential application in carbon dioxide sequestration

Polypropylene (PP) was blended with branched polyethylenimine (PEI) with the aim to prepare blends having CO₂ adsorption property. The CO₂ adsorption properties will be conferred due to the presence of variety of amine functionality in PEI. PEI contains primary, secondary as well as tertiary amine groups. Before testing CO₂ adsorption, PP–PEI blends were characterized using variety of techniques, for example, differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis, scanning electron microscopy, and polarized light optical microscopy. In this work, we have studied in detail both compatibilized as well as noncompatibilized blends of PP and PEI. The compatibilization was achieved via addition of maleic anhydride grafted PP. Finally, all the compatibilized as well as noncompatibilized blends were studied for CO₂ adsorption. The compatibilized blends showed better thermal, mechanical as well as CO₂ adsorption properties as compared to the noncompatibilized blends. POLYM. ENG. SCI., 59:2092–2102, 2019. © 2019 Society of Plastics Engineers     

Prenatal exposure to the fluoride containing psychiatric drug fluoxetine and anti-oxidative alterations in the neonatal rat brain

Fluoride is a key ingredient of many psychiatric drugs like fluoxetine (Prozac^®, Fluoxetine^®). Pregnant women frequently use this drug as they suffer from depression and anxiety disorders during this period. Fluoxetine is able to reach the fetus through the placenta and passes to the newborn through milk. In the present study, female Wistar rats were treated with 5, 10, and 20 mg/L fluoxetine (containing 94% fluorides) from pregnancy day 10 to day 20. After delivery, the levels of the enzymatic antioxidants in the brain of their offspring at postnatal day 2 were measured. The results showed that, in all fluoxetine exposed groups compared with the control group, there was a significant decrease (P < 0.01) in the glutathione, catalase, glutathione S-transferases and potassium and a non- significant increase (P > 0.05) in the activity of malondialdehyde and creatine kinase. The results suggest that fluoxetine may be a developmental neurotoxicant due to presence of fluoride hence must be used carefully during pregnancy.     

The effect of seasonal variation on automated land cover mapping from multispectral airborne laser scanning data

Multispectral airborne laser scanning (MS-ALS) sensors are a new promising source of data for automated mapping methods. Finding an optimal time for data acquisition is important in all mapping applications based on remotely sensed datasets. In this study, three MS-ALS datasets acquired at different times of the growing season were compared for automated land cover mapping and road detection in a suburban area. In addition, changes in the intensity were studied. An object-based random forest classification was carried out using reference points. The overall accuracy of the land cover classification was 93.9% (May dataset), 96.4% (June) and 95.9% (August). The use of the May dataset acquired under leafless conditions resulted in more complete roads than the other datasets acquired when trees were in leaf. It was concluded that all datasets used in the study are applicable for suburban land cover mapping, however small differences in accuracies between land cover classes exist.