Microstructure and mechanical properties of ternary mortars with brick powder,glass powder,slag, fly ash,and limestone

The objective of this research is to study the effects produced by ternary binders which combine the addition of waste brick powder with fly ash, limestone, ground granulated blast furnace slag or waste glass powder in the microstructure and mechanical properties of mortars. In these ternary binders, the ordinary Portland cement was partially replaced by 10% of waste brick powder and 10% of another of the abovementioned additions. Mortars prepared with ordinary Portland cement without additions were also prepared. The microstructure was characterized with mercury intrusion porosimetry, electrical resistivity, and thermogravimetric analyses. Ultrasonic pulse velocity, compressive and flexural strengths were also determined. Mortars made using ternary binders with two active additions showed higher pore refinement and higher electrical resistivity at 250 days. Furthermore, their compressive strength and ultrasonic pulse velocity were relatively similar or even higher than that noted for reference specimens.     

Microparticles based on hydrophobically modified chitosan as drug carriers

In this work, a hydrophobically modified (HM) chitosan derivative was prepared by covalent linkage of C₁₂ groups to the chitosan backbone. HM‐chitosan microparticles were prepared according to an emulsification‐solvent evaporation method and naltrexone (NTX) was used as a model drug. For comparison, unmodified chitosan and poly lactic‐co‐glycolic acid (PLGA) microparticles were also tested as carriers for NTX. HM‐chitosan formed viscous semi‐dilute solutions, suggesting a high level of chain entanglements and hydrophobic associations. HM‐chitosan microparticles generally showed higher production yield and encapsulation efficiency, as compared with chitosan and PLGA. The burst release shown by chitosan microparticles was significantly reduced when using the HM‐chitosan derivative. An enhanced control of drug release was observed over at least 50 days. PLGA particles demonstrated inferior controlled release properties as compared to HM‐chitosan subsequent to the initial release stage. These results revealed the potential of hydrophobic modification of chitosan as a means to improve the stability and sustained delivery properties of the polymer. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40055.     

Influence of the processing parameters and composition on the thermal stability of PLA/nanoclay bio‐nanocomposites

Poly(lactic acid) (PLA) is one the most promising bio‐based and biodegradable polymer. However, its low thermal stability limits the range of applications and complicates its transformation via the most industrial common processes. The novelty of this work is studying the thermal stability of PLA and PLA/clay nanocomposites during use, as a function of the composition and using a wide range of extrusion and injection moulding processing parameters. To improve the thermal stability of the PLA, laminar silicates containing different organomodifications have been added (Cloisite 20A and Cloisite 30B). The results show that the processing conditions and composition define the morphology of the bio‐nanocomposites, which plays key role in defining final thermal properties of the material. In general, clays improve the thermal stability of the processed material, increasing the degradation temperature and decreasing the degradation rate under a wide range of processing conditions. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40747.     

Influence of Reaction Conditions on the Settling Behavior of Liquid-Liquid Dispersions

The settling behavior of liquid-liquid dispersions at ambient temperature and pressure is well investigated. However, little is known about the settling behavior of those systems at high pressure and high temperature. In this work, a novel stainless steel settling cell is presented, enabling investigations on liquid-liquid settling behavior at high pressures up to 130 bar. The settling behavior of a promising CO₂ hydrogenation reaction system is investigated by sequentially determining influences of dissolved CO₂, side components, and temperature.     

Short-Term Immune Responses of Gilthead Seabream (Sparus aurata) Juveniles against Photobacterium damselae subsp. piscicida

Photobacteriosis is a septicaemic bacterial disease affecting several marine species around the globe, resulting in significant economic losses. Although many studies have been performed related to the pathogen virulence and resistance factors, information regarding the host defence mechanisms activated once an infection takes place is still scarce. The present study was designed to understand innate immune responses of farmed juvenile gilthead seabream (Sparus aurata) after Photobacterium damselae subsp. piscicida (Phdp) infection. Therefore, two groups of seabream juveniles were intraperitoneally injected with 100 µL of PBS (placebo) or 100 µL of exponentially growing Phdp (1 × 10⁶ CFU/mL; infected). The blood, plasma, liver, and head kidney of six fish from each treatment were sampled immediately before infection and 3, 6, 9, 24 and 48 h after infection for the broad screening of fish immune and oxidative stress responses. Infected animals presented marked anaemia, neutrophilia and monocytosis, conditions that are correlated with an increased expression of genes related to inflammation and phagocytic activity. Similar studies with different fish species and bacteria can be useful for the definition of health biomarkers that might help fish farmers to prevent the occurrence of such diseases.     

Comparative performance of carbon nanotube and nanoclay on thermal properties and flammability behavior of amorphous polyamide/SEBS blend

Multiwall carbon nanotubes (CNT) or montmorillonite clay (MMT-30B) were added to a poly(hexamethylene isophthalamide-co-terephthalamine) (an amorphous polyamide - aPA) and styrene-ethylene/butylene-styrene graphitized with maleic anhydride (SEBS) blend, in different concentrations, in order to investigate the morphology, thermal properties and flammability behavior. Different nanoparticle localizations in the phase blend were observed through transmission electronic microscopy. CNT nanoparticles are localized in SEBS phase, and MMT-30B nanoparticles in aPA phase. No significant changes were observed on transition temperatures and thermal stability with both nanoparticle additions. However, a slight increase on storage modulus for clay nanocomposites and a slight reduction for carbon nanotube nanocomposites were observed, due to their different phase localizations. Regarding flammability, CNT nanocomposites showed better performance as a flame retardant when compared to samples with MMT-30B. Although the MMT-30B nanocomposites could not be classified according to the UL-94 criteria, no dripped flaming particles were observed, due to the a char barrier formation on the polymer surface. The CNT nanocomposites were classified according to the UL-94 criteria as V-2. The CNT's selective localization on the SEBS phase decreases its heat-release rate, but no interconnected network structure was formed in the matrix to suppress the dripping flaming particles.     

Effect of finishing and ageing time on quality attributes of loin from the meat of Holstein–Fresian cull cows

The effects of finishing time, (T0 = 0, T1 = 30 and T2 = 60 days), on Holstein–Friesian cull cows (n = 18) and post-mortem ageing, (1, 7, 14, 21, 35 and 42 days), under vacuum conditions of Longissimus thoracis (LT) muscles were investigated. The objective of this research was to study how finishing feeding (based on a commercial concentrate and corn silage), following a pasture period of 90 days, affected carcass and meat quality. Ageing time effect was also evaluated on the main quality attribute of added value pieces, such as “striploin of ox” from cull cows. Finishing treatment affected intramuscular fat content (IMF), moisture percentage, water-holding capacity (WHC), colour parameters and shear force of meat at 24 h post-mortem, whereas ageing time enhanced meat tenderness, when this was measured by two textural tests, Warner–Braztler (WB) and textural profile analysis (TPA). A minimum shear force was achieved at 7 and 14 days of ageing for T1 and T2, respectively. No differences (P > 0.05) could be found in colour parameters from 7 to 42 days. The results show that a finishing time of two months is very beneficial, due to the increase in meat fatness, improved overall carcass quality and luminosity (L*). Furthermore, 14 ageing days were sufficient to improved tenderness. Ageing time did not have an effect on lipid oxidation (P > 0.05) and this leads us to conclude that meat shelf life exceeded 42 days under vacuum conditions’.     

The effect of environmental conditions on nutritional quality of cherry tomato fruits: evaluation of two experimental Mediterranean greenhouses

BACKGROUND: The aim of this study was to examine how different environmental factors (temperature, solar radiation, and vapour‐pressure deficit [VPD]) influenced nutritional quality and flavour of cherry tomato fruits (Solanum lycopersicum L. cv. Naomi) grown in two types of experimental Mediterranean greenhouses: parral (low technology) and multispan (high technology). RESULTS: Fruits were sampled three times during 3 years (2004, 2005 and 2006): at the beginning, middle and end of the fruit production period. Values for temperature, solar radiation, and VPD peaked in the third sampling in both greenhouses; values were higher in the parral‐type greenhouse, triggering abiotic stress. This stress reduced the accumulation of lycopene and essential elements, augmenting the phytonutrient content and the antioxidant capacity of tomatoes. During the third sampling, sugars were increased while organic acid content diminished, producing tomatoes with a sweeter‐milder flavour. The parral greenhouse produced tomatoes with higher phenolic compounds and ascorbic acid contents, together with a greater antioxidant capacity, without showing differences in flavour parameters. CONCLUSION: The higher phytonutrients content and antioxidant activity during the environmental stress, more pronounced in parral than multispan greenhouse, together with the sweeter‐milder flavour, conferred a notable nutritional benefit, which considerably improved the nutritional and organoleptic quality of these tomatoes. Copyright © 2010 Society of Chemical Industry