A New Alternative for Obtaining Nanocrystalline Bioactive Coatings: Study of Hydroxyapatite Deposition Mechanisms by Cold Gas Spraying

The present article is intended to study the deposition mechanisms of bioactive hydroxyapatite (HA) particles by means of Cold Gas Spraying (CGS). A comparison of the deposition on two different substrates (Ti6Al4V and Al7075T6) and different particle sizes is presented. Although this is a more specific deposition technique for ductile materials, it is here shown that, in certain conditions, ceramic deposition is possible despite the inherent low ductility. The resulting internal structure and the features at the particle–substrate interface are discussed in view of Transmission Electron Microscopy examinations of a Focused Ion Beam lift‐out prepared sample. Mainly, under shock compressive loading, the porous sintered powder proceeds through pore collapse, fragmentation and densification as well as grain refinement. The process is described through different plastic mechanisms in ceramics. This opens a new alternative route to produce nanocrystalline HA coatings through a cost‐effective process.     

Cu(In,Ga)Se2 solar cell grown on flexible polymer substrate with efficiency exceeding 17%

Development of a Cu(In,Ga)Se₂ thin film solar cell on a polyimide film with a conversion efficiency of 17.1%, measured under standard test conditions at the European Solar Test Installation (ESTI) of the Joint Research Centre (JRC) of the European Commission, Ispra, is reported. The drastic improvement from the previous record of 14.1% efficiency is attributed to a more optimized compositional grading, better structural and electronic properties of the absorber layer as well as reduced reflection losses. Basic film and device properties, which led to the improvement in the efficiency record of flexible solar cells are presented for the new process and compared to the old process. Copyright © 2011 John Wiley & Sons, Ltd.     

Tribological Behavior of Deagglomerated Active Inorganic Nanoparticles for Advanced Lubrication

The tribological behavior of novel, deagglomerated, and active molybdenum disulfide (MoS₂) nanoparticles as additives in paraffin oil is presented. In a novel approach, the MoS₂ nanoparticles were activated by their intercalation with organic molecules, particularly triglycerides (canola oil) and lecithin (source of phosphorus). A four-ball tribological test setup was used to measure the wear scar diameter, the coefficient of friction, and the extreme pressure properties of such formulated paraffin oils. The results showed significant influence of this uniquely designed MoS₂ nanostructured additive on the coefficient of friction (0.07), the wear scar diameter, and the extreme pressure (315 kg) properties of the paraffin oil. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive x-ray spectroscopy (EDS) were also used for investigating size, the surface morphology, and the elemental composition of the nanoengineered lubricant. The characterization revealed a particle size less than 100 nm and the elemental composition analysis of the wear track showed the presence of Mo, S, and P in the tribofilm, explaining the observed improvements in the tribological properties.     

Non-destructive flavour evaluation of red onion (Allium cepa L.) Ecotypes: An electronic-nose-based approach

This work reports preliminary results on the potential of a metal oxide sensor (MOS)-based electronic nose, as a non-destructive method to discriminate three “Tropea Red Onion” PGI ecotypes (TrT, TrMC and TrA) from each other and the common red onion (RO), which is usually used to counterfeit. The signals from the sensor array were processed using a canonical discriminant function analysis (DFA) pattern recognition technique. The DFA on onion samples showed a clear separation among the four onion groups with an overall correct classification rate (CR) of 97.5%.     

Rheological Studies During Submerged Citric Acid Fermentation by Aspergillus niger in Stirred Fermentor Using Apple Pomace Ultrafiltration Sludge

Rheological profile studies for apple pomace ultrafiltration sludge (APS) broth with filamentous fungus, Aspergillus niger NRRL-567 during citric acid (CA) fermentation are reported for the biomass developed in a 7.5 l bench scale fermentor. CA bioproduction of 23.67?±?1.0 g/l APS and 40.34?±?1.98 g/l APS was obtained in control (120 h) and in treatment with inducer, MeOH 3% (v/v), respectively, after 132 h of fermentation by A. niger NRRL 567. The rheological properties of the fermentation broth including pellets were analyzed. The control demonstrated non-Newtonian pseudoplastic behaviour due to more filamentous growth. However, in treatment supplemented with inducer (methanol), pellet form was observed during fermentation with less viscous non-Newtonian broths. The power law model was followed with good confidence of fit (77.8–88.9%) throughout the fermentation in treatment with MeOH as an inducer. However, power law was followed with moderate fit of confidence (65.3–75.9%) at the beginning of fermentation until 48 h and later followed a good confidence of fit (75.9–88.2%) until 144 h of fermentation in control. Important rheological changes occurred in the broth during maximal CA production phase along with increase in biomass in the pelleted mycelium form.     

Calcium carbonate (CaCO3) nanoparticle filled polypropylene: Effect of particle surface treatment on mechanical,thermal, and morphological performance of composites

The present study was aimed to see the effect of surface treatment on nanocomposites with different fatty acids (stearic acid and oleic acid) having two different coupling agents (titanate and silane). Nanocomposites were prepared via melt mixing in Haake 90 twin screw extruder. The characterization of nanocomposites had been carried out using various advance analytical techniques such as dynamic mechanical analysis, thermogravimetric analysis, heat distortion temperature, melt flow index, and scanning electron microscopy. The strength and stiffness were also improved with the incorporation of maleic‐anhydride grafted ethylene propylene rubber in PP/Nano‐CaCO₃ nanocomposites. The tensile, flexural, and impact strength properties of PP/MA‐g‐EPR/treated‐CaCO₃ and untreated nanocomposites were determined. These studies revealed that stearic acid treated nanofiller filled composites had better properties than those of untreated and oleic acid treated nanofiller filled composites. The SEM studies demonstrated that the dispersion and distribution of Nano‐CaCO₃ (nCaCO₃) particles within the polypropylene matrix were dependent on the nature of surface treating agents. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Novel aromatic and aromatic–aliphatic poly(thiourea‐amide)s for the extraction of toxic heavy metal ions

A series of novel aromatic and aromatic–aliphatic diamines [isophthaloyl bis(3‐(3‐aminophenyl)thiourea), terephthaloyl bis(3‐(3‐aminophenyl)thiourea), adipoyl bis(3‐(3‐aminophenyl)thiourea), sebacoyl bis(3‐(3‐aminophenyl)thiourea)] were synthesized starting from the dinitro compounds. Spectroscopic and elemental analyses were carried out for the structure elucidation of the monomers. Three series of poly(thiourea‐amide)s (PTAMs) bearing C?S groups were prepared through the condensation of new diamines with the diacid chlorides such as isophthaloyl, terephthaloyl and adipoyl chloride. The ensuing PTAMs were characterized using FTIR, ¹H‐NMR and ¹³C‐NMR techniques. Physical properties of the polymers such as solution miscibility, crystallinity, solution viscosity, molecular weight, and thermal properties were measured. Consequently, good organosolubility of these polymers was experiential in amide solvents as DMAc, DMF, DMSO and NMP. Moreover, PTAMs exhibited η_inh in the range of 0.92–1.56 dL/g and GPC measurements revealed M_w around 607 × 10²‐851 × 10². DSC served to envisage the glass transition temperatures (T_g) of poly(thiourea‐amide)s located between 232 and 258°C and the initial decomposition temperatures (T₀) probed by thermogravimetry were in the range of 305–419°C. Structure‐property relationship of these polymers was also studied. Eventually, solid?liquid extraction tests of the selected poly(thiourea‐amide)s systems revealed excellent results because these polymers show nearly 100% elimination of lead and mercury cations from water media. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Performance analysis of flexible multirecess hydrostatic journal bearing operating with micropolar lubricant

This paper presents the analytical study of the effect of the bearing shell flexibility on the performance of multirecess hydrostatic journal bearing system operating with micropolar lubricant. The modified Reynolds equation for the flow of micropolar lubricant through constant flow valve‐compensated hydrostatic journal bearing has been solved by finite element technique based on Galerkins method, and the resulting elastic deformation in the bearing shell due to fluid‐film pressure has been determined iteratively, in which the deformation coefficient accounts for the bearing shell flexibility. The computed results suggest that the influence of the micropolar effect on bearing performance characteristics is significantly affected by the bearing shell flexibility. Copyright © 2012 John Wiley & Sons, Ltd.     

Antioxidant effects of broccoli powder extract in goat meat nuggets

The antioxidant potential of broccoli powder extract (BPE) was determined and evaluated in goat meat nuggets at three different levels 1, 1.5 and 2%, compared with control and butylated hydroxyl toluene (100ppm BHT). Total phenolics in 5mg broccoli powder was higher (P<0.05) than 100ppm BHT. Free radical scavenging activity of 2.25mg and 3mg broccoli powder was found similar to 50 and 100ppm BHT. Reducing power of 10mg broccoli powder was comparable to the 100ppm BHT. Incorporation of 1.5 and 2% BPE decreased (P<0.05) the pH value of the products. Total phenolics in product with 2% BPE was similar to BHT nuggets. Chroma value of products with 1.5 and 2% BPE was lower (P<0.05) than control and BHT nuggets. Thiobarbituric acid reactive substances number of BPE nuggets was lower (P<0.05) than control throughout the storage. Thus 2% BPE can be used as natural antioxidant in goat meat nuggets without affecting product acceptability.     

Quality characteristics of low-fat chicken nuggets: effect of common salt replacement and added bottle gourd (Lagenaria siceraria L.)

BACKGROUND: There is growing demand for the meat products having healthier characteristics. In an endeavour to develop low‐salt, low‐fat and high‐fibre chicken nuggets an investigation was carried out to observe the effects of partial replacement (40%) of sodium chloride in pre‐standardised low‐fat chicken nuggets (Control, 20 g kg^?1 NaCl) with a salt substitute blend as well as incorporation of bottle gourd (Lagenaria siceraria L.) in the resulting low‐salt, low‐fat products at three different levels, i.e. 50, 75 and 100 g kg^?1 (Treatments, 12 g kg^?1 NaCl) on the various quality attributes. RESULTS: Sodium chloride replacement decreased (P < 0.01) emulsion and product pH, cooking yield, moisture, ash, yellowness, hue value and textural properties. pH values, moisture and dietary fibre increased (P < 0.01) while cooking yield, % protein, textural properties and total cholesterol were decreased with the incorporation of bottle gourd in low‐salt, low‐fat nuggets. Sensory attributes of the product were not affected with salt replacement; however, inclusion of bottle gourd at higher levels decreased (P < 0.05) flavour and texture scores. CONCLUSION: The results suggest that low‐salt, low‐fat and high‐fibre chicken nuggets can be developed with the use of a salt substitute blend and bottle gourd without affecting their acceptability. Copyright © 2012 Society of Chemical Industry