Improvement of fuel properties of cottonseed oil methyl esters with commercial additives

The low temperature operability and oxidative stability of cottonseed oil methyl esters (CSME) were improved with four anti‐gel additives as well as one antioxidant additive, gossypol. Low temperature operability and oxidative stability of CSME was determined by cloud point (CP), pour point (PP), cold filter plugging point (CFPP), and oxidative stability index (OSI). The most significant reductions in CP, PP, and CFPP in all cases were obtained with Technol®, with the average reduction in temperature found to be 3.9 °C. Gunk®, Heet®, and Howe's® were progressively less effective, as indicated by average reductions in temperature of 3.4, 3.0, and 2.8 °C, respectively. In all cases, the magnitude of CFPP reduction was greater than for PP and especially CP. Addition of gossypol, a polyphenolic aldehyde, resulted in linear improvement in OSI (R² = 0.9804). The OSI of CSME increased from 5.0 to 8.3 h with gossypol at a concentration of 1000 ppm.     

Incorporation of active nano-hybrids into poly(ε-caprolactone) for local controlled release: Antifibrinolytic drug

The antifibrinolytic drug trans-4-(aminomethyl)cyclohexanecarboxylate (tranexamic anions) was intercalated by anion exchange into Mg/Al layered double hydroxide (LDH). The hybrid, of formula [Zn_0.65Al_0.35(OH)₂]Trx_0.24(CO₃)_0.055 × 1.5H₂O, was characterized by chemical and thermal analyses and X-ray powder diffraction.Different amounts of the hybrid material were incorporated into poly(ε-caprolactone) by high energy ball milling technique and processed as films. The composite materials were analyzed by X-ray diffractometry, thermogravimetry and FT-IR spectroscopy to clarify the filler-polymer structural organization. An investigation of the mechanical properties of the composite showed an improvement of mechanical parameters, in particular the elastic modulus, when compared to of the pristine polymer. Thus, the inorganic component, even in small quantities, beside acting as a reservoir of active molecular anions, can improve the physical properties.A new method for the quantitative determination of tranexamic anions by infrared spectroscopic analysis was proposed and the release process of the tranexamic anions from the composite into a physiological solution was monitored. The release consisted of two stages: a first stage, very rapid as a burst, in which a small fraction of intercalated drug was released and of a second stage over longer time, much slower than the first.The composites are very promising in the preparation of new hybrid polymeric materials to be used for the molecular delivery of drugs in topical applications, as suture threads or medicate scaffolds.     

Does photoelectrocatalysis by TiO2 work?

BACKGROUND: This paper examines TiO₂ photoelectrocatalysis (PEC), a process that increases the efficiency of TiO₂ photocatalysis (PC) by applying a potential to separate the UV‐generated charge carriers whose recombination typically limits photonic efficiencies of conventional photocatalysis. RESULTS: Four representative photoelectrocatalytic reactions, nitrophenol oxidation, oxalate degradation, E. coli inactivation and dye decolouration were considered. For all four, a small applied potential raised the rate of pollutant removal by TiO₂ electrodes. Because the improvements were probably insufficient to make PEC technologically viable except in niche applications, rates of pollutant removal by PEC and by PC using TiO₂ particle dispersions were directly compared. PEC rates were not significantly larger than rates of PC by dispersions. CONCLUSION: Discussions of the implications of these conclusions focus on whether PEC is currently limited by reactor design (irradiation geometry, or mass transfer) or by electrode materials. It is inferred that the performance of present electrodes is not limited significantly by mass transfer constraints. Since the choice of electrode materials (sol–gel or thermal electrodes) has been shown to influence PEC efficiency, recent results on titania nanotubes (TNT) are reviewed. It is concluded that the enhancement factors—the PEC:PC ratio—of TNT electrodes are no higher than those of conventional materials. Copyright © 2011 Society of Chemical Industry     

Manipulating the taste-related composition of strawberry fruits (Fragaria × ananassa) from different cultivars using deficit irrigation

Demand and, consequently, production of strawberry fruits has increased over the past few years and, as a result, the water abstractions for cultivation of this fruit have risen considerably. To limit the amounts of water used for several horticultural crops, water deficit irrigation (DI) has been seen as a potential alternative for new cultivation systems. DI in strawberry fruits is generally associated with reduction in berry size and yield; however, a recent study demonstrated that DI on strawberry can increase the concentration of some taste- and health-related compounds in fruits from cv. Elsanta. Hence, the aim of the present study was to further corroborate such findings and to assess the response (and variability) among different strawberry cultivars (namely Christine, Elsanta, Florence, Sonata and Symphony) to imposed water-DI conditions. Water-DI affected both fruit physiology and biochemistry. Nevertheless, the response to drought stress was different for each of the cultivars tested. Plants from cvs. Elsanta, Sonata and Symphony showed a greater reduction in berry size, accompanied by a significant increase in dry matter content for fruit harvested from DI-treated plants. Concomitant to this, and where dry matter was increased, the concentrations of sugars and some acids were generally higher in DI-derived fruit. In contrast, cvs. Florence and Christine did not show significant variations in berry weight or any of the target analytes measured when grown under the conditions imposed in this study. The results presented herein suggest that reducing water irrigation between flower initiation and fruit harvest may be a viable technique for increasing the concentrations of taste-related compounds in cvs. Elsanta, Sonata and Symphony and it may not have a negative impact on overall fruit size of cvs. Christine and Florence.     

Searching for differences in race: Is there evidence for preferential detection of other-race faces?

Previous research has suggested that like animal and social fear-relevant stimuli, other-race faces (African American) are detected preferentially in visual search. Three experiments using Chinese or Indonesian faces as other-race faces yielded the opposite pattern of results: faster detection of same-race faces among other-race faces. This apparently inconsistent pattern of results was resolved by showing that Asian and African American faces are detected preferentially in tasks that have small stimulus sets and employ fixed target searches. Asian and African American other-race faces are found slower among Caucasian face backgrounds if larger stimulus sets are used in tasks with a variable mapping of stimulus to background or target. Thus, preferential detection of other-race faces was not found under task conditions in which preferential detection of animal and social fear-relevant stimuli is evident. Although consistent with the view that same-race faces are processed in more detail than other-race faces, the current findings suggest that other-race faces do not draw attention preferentially. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bioinspired pressure actuated adhesive system

We developed a dry synthetic adhesive system inspired by gecko feet adhesion that can switch reversibly from adhesion to non-adhesion with applied pressure as external stimulus. Micropatterned polydimethylsiloxane (PDMS) surfaces with pillars of 30 μm length and 10 μm diameter were fabricated using photolithography and moulding. Adhesion properties were determined with a flat probe as a function of preload. For low and moderate applied compressive preloads, measured adhesion was 7.5 times greater than on flat controls whereas for high applied preloads adhesion dropped to very low values. In situ imaging shows that the increased preload caused the pillars to deform by bending and/or buckling and to lose their adhesive contact. The elasticity of PDMS aids the pillar recovery to the upright position upon removal of preload enabling repeatability of the switch.     

Potential use of chemical cues for colony-mate recognition in the big brown bat,Eptesicus fuscus

Bats should benefit from recognition of their roost-mates when colonies form stable social units that persist over time. We used Y-maze experiments and gas chromatography–olfactometry (GC-O) to evaluate whether female big brown bats Eptesicus fuscus (Chiroptera: Vespertilionidae) use chemical cues to distinguish among conspecifics. In dual-choice Y-maze experiments, females chose the scent of another female from their own roost over a conspecific female from a different roost in a majority of trials. Analysis of total body odors using GC-O suggests that individuals from a given colony may share a more common odor signature with roost-mates than with non-roost-mate conspecifics. Using four principle components derived from 15 odor variables, discriminant function analysis correctly assigned most individuals to the correct colony.     

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