Suripeddi Srinivas^a , Akshay Gupta^b,*, Ashish Kumar Kandoi^b

Frontiers in Heat and Mass Transfer, Vol.5, pp. 1-12, 2014, DOI:10.5098/hmt.5.21

Abstract The present work deals with the flow and thermal analysis of nanofluid in the wavy channels. The governing flow equations are solved numerically using CFD package assuming single phase approach. To study the effect of the concentration and size variation of the nanoparticle, the concentration and size are varied from 0% - 5% and 25 nm - 100 nm respectively over the Reynolds number range of 250-1500 for Au-water nanofluid. The effect on heat transfer enhancement because of corrugation of wavy channel is analyzed on four different shapes (sinusoidal, triangular, trapezoidal and square) channels. The More >

Alicia Mujica-Garcia^1,2, Iván Navarro-Baena¹, José Maria Kenny^1,2, Laura Peponi^2,*

Journal of Renewable Materials, Vol.2, No.1, pp. 23-34, 2014, DOI:10.7569/JRM.2013.634130

Abstract The main aim of this research is the production of different biopolymeric fi bers by electrospinning and the determination of the optimum working parameters for each polymer analyzed. In particular, three different biopolymers have been studied: poly(lactic acid) (PLA), poly(ε-caprolactone) (PCL) and a synthesized poly(ester-urethane) based on a synthesized PLA-b-PCL-b-PLA tri-block copolymer. This research is focused on the analysis of the infl uence of the processing parameters, such as the concentration and fl ow-rate of the polymer solution and the applied voltage, as well as the physico-chemical properties of the polymers used, on the fi More >

A. Pizzi^1,2,*, C. Zollfrank³, X. Li¹, M. Cangemi¹, A. Celzard⁴

Journal of Renewable Materials, Vol.2, No.3, pp. 230-234, 2014, DOI:10.7569/JRM.2014.634114

Abstract Protein rigid foams based on albumin coreacted with camphor and an aldehyde were converted into silicon carbide (SiC) foams. This was carried out by putting albumin-derived template foams in contact with silicon compounds in liquid phase and calcinating the mix obtained at a relatively low temperature of 500°C to eliminate the protein and leave the SiC foam. The transformation was followed by scanning electron microscopy (SEM) from the natural albumin foams to the gel obtained by infi ltrating them with tetraethyl orthosilicate (TEOS) and to the appearance of the SiC foams after calcination. X-ray diffraction More >

M.C. Lagel¹, A. Pizzi^1,2, S. Giovando³, A. Celzard⁴

Journal of Renewable Materials, Vol.2, No.3, pp. 220-229, 2014, DOI:10.7569/JRM.2014.634113

Abstract With the depletion of fossil resources, tannin extracts can be a natural alternative to some synthetic products. Hydrolysable chestnut tannin extracts have been used to partially replace phenol in PF resins for phenolic rigid foams. Phenol-formaldehyde-chestnut tannin (PFT) phenolic foams were initially made from copolymerized PFT resins of different molar ratio. The PFT foams so prepared were tested for thermal conductivity, these being slightly worse than that of pure PF foams; and for mechanical and water absorption, these two properties being better than those of pure PF foams. Indeed, PF resins represent an important part More >

M.C. Lagel^1,*, A. Pizzi^1,2, S. Giovando³

Journal of Renewable Materials, Vol.2, No.3, pp. 207-219, 2014, DOI:10.7569/JRM.2014.634111

Abstract Natural hydrolysable chestnut tannin extracts used to partially substitute phenol in Phenol-Formaldehyde (PF) resins for phenolic rigid foams were analysed by matrix-assisted desorption ionization time of fl ight (MALDI-TOF) mass spectrometry. PF only, chestnut only and PF-chestnut copolymerised oligomer types and distribution were determined. MALDI-TOF analyses of a PF control resin (with the same molar ratio) and of chestnut tannin extracts were performed in order to identify the peaks of molecular weights corresponding to copolymers of chestnut tannins with phenol and formaldehyde. More >

A. Sauget^1,*, X. Zhou¹, A. Pizzi^1,2

Journal of Renewable Materials, Vol.2, No.3, pp. 186-200, 2014, DOI:10.7569/JRM.2013.634138

Abstract Glyoxal and glutaraldehyde are two viable alternatives to formaldehyde for the preparation of tanninresorcinol-aldehyde adhesive but lead to less resistant glue joint. Tannin-resorcinol-glyoxal (TRG1) and tannin-resorcinol-glutaraldehyde (TRG2) resins have been prepared and analyzed by matrix-assisted laser desorption/ionization time of fl ight (MALDI-ToF) spectrometry to understand the chemical process behind the pre-curing of these resins and possibly the causes of this lower resistance. The analysis showed that TRG resins are not a simple mix of resorcinol-aldehydes oligomers and fl avonoids, but a much more complex combination of various species including tannin-aldehydes and tannin-resorcinol oligomers. More >

M.C. Basso^1,2, S. Giovando³, A. Pizzi^2,4,*, M.C. Lagel^2,3, A. Celzard⁵

Journal of Renewable Materials, Vol.2, No.3, pp. 182-185, 2014, DOI:10.7569/JRM.2013.634137

Abstract Condensed fl avonoid tannin foams were obtained under alkaline conditions. This entailed the elimination of furfuryl alcohol from these formulations, as under alkaline conditions, foam preparation could not rely on the heat generated by the self-condensation of furfuryl alcohol, which occurs only under strongly acidic conditions. The approach used to formulate the alkaline foam was: (i) the total elimination of furfuryl alcohol from the formulation, (ii) coupled with the use of an aldehyde hardener different from formaldehyde (for environmental reasons) and (iii) the application of moderate heat to allow foaming. These were not tannin/ furanic More >

A. Sauget^1,*, X. Zhou¹, A. Pizzi^1,2

Journal of Renewable Materials, Vol.2, No.3, pp. 173-181, 2014, DOI:10.7569/JRM.2013.634128

Abstract Tannin-resorcinol-formaldehyde (TRF) resin shows a good compatibility with natural fl ax fi bers and yields composite materials of good mechanical properties when using paraformaldehyde as a hardener. Different formulations, curing parameters and processes such as high-temperature curing in press or spray-drying have been explored in order to adapt this resin to composite manufacturing and to improve the properties of this new material. Additional testing has been performed on the TRF resin by thermomechanical analysis to observe its reactivity at different pH and with the use of different hardeners. More >

Gul B¹, M Islam², S Ahmad³, S Gul¹

Phyton-International Journal of Experimental Botany, Vol.83, pp. 415-421, 2014, DOI:10.32604/phyton.2014.83.415

Abstract The effect of fire on growth and nutritive value of Saccharum griffithii Munro ex Boiss-ravennae (Linn.) Murr. hybrid, a low palatable perennial grass in the semi-arid region of the highlands of Balochistan, Pakistan, was evaluated during 2008 and 2009. Prescribed fire treatments were applied in February 2008 and 2009 at the dormant stage of vegetation. Different growth parameters (tiller height, tiller number/plant), forage production (fresh, dry) and nutritive value (crude protein, ash) were compared with control (unburnt) plots. Fire increased the number of tillers, and the fresh and dry forage production in both years. Fire also More >

Qian J^1,2, Z Wang¹, Z Liu¹, W Kuang^1,2, CA Busso³

Phyton-International Journal of Experimental Botany, Vol.83, pp. 407-414, 2014, DOI:10.32604/phyton.2014.83.407

Abstract Understanding the changes in the total bud bank, and its contribution to community regeneration, in response to grassland enclosure to livestock grazing, is crucial for grassland management. Despite its importance, the contribution of the total bud bank and that of different bud types to community regeneration as a whole have been rarely explored. The vegetative offspring recruited from different bud types was investigated in grasslands having different enclosure durations to livestock grazing on a typical steppe of Inner Mongolia, China. Total vegetative offspring density was significantly higher (p<0.05) under continuous grazing than in fenced grasslands,… More >