Sustainable Oxidative Cleavage of Vegetable Oils into Diacids by Organo-Modified Molybdenum Oxide Heterogeneous Catalysts

Exploiting vegetable oils to produce industrially valuable diacids via an eco‐friendly process requires an efficient and recyclable catalyst. In this work, a novel catalytic system based on organo‐modified molybdenum trioxide was synthesized by a green hydrothermal method in one simple step, using Mo powder as precursor, hydrogen peroxide, and amphiphilic surfactants cetyltrimethylammonium bromide (CTAB) and tetramethylammonium bromide (TMAB) as capping agents. The synthesized materials were first characterized by different techniques including XRD, SEM, TGA, and FT‐IR. Interestingly, various morphologies were obtained depending on the nature of the surfactants and synthetic conditions. The synthesized catalysts were employed in oxidative cleavage of oleic acid, the most abundant unsaturated fatty acid, to produce azelaic and pelargonic acids with a benign oxidant, H₂O₂. Excellent catalytic activities resulting in full conversion of initial oleic acid were obtained, particularly for CTAB‐capped molybdenum oxide (CTAB/Mo molar ratio of 1:3) that gave 83 and 68% yields of production of azelaic and pelargonic acids, respectively. These are the highest yields that have been obtained for this reaction by heterogeneous catalysts up to now. Moreover, the CTAB‐capped catalyst could be conveniently separated from the reaction mixture by simple centrifugation and reused without significant loss of activity up to at least four cycles.     

Structured Estolides: Control of Length and Sequence

Using ester-forming reactions such as carbodiimide coupling and a modified Yamaguchi symmetrical anhydride method, a variety of estolides based on 17-hydroxy oleic and 17-hydroxy stearic acid have been prepared. These hydroxy fatty acids are produced in good yields from hydrolysis of sophorolipids, which are in turn derived from fermentation of fats and oils. Since the estolides are formed one unit, or ester bond, at a time, their length and sequence can be precisely controlled. The key to this control is the use of protecting groups at either the carboxylic or hydroxy end of the starting hydroxy fatty acids. Two mono-protected dimers, for example, when combined in a fragment-condensation approach, give a tetramer with no “contamination” from estolides of other lengths. This methodology opens the way to functionalized estolides, and several variants were prepared: hybrid estolides, containing non-fatty acid moieties such as amino acids; polymerizable estolides, containing a norbornene unit; and non-linear estolides that extend from a branched core such as glycerol or pentaerythritol. With the benzoyl chloride-mediated symmetrical anhydride method, yields for individual coupling steps ranged from 75 to 93%. Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the US Department of Agriculture.     

Civil Liabilities for Unsafe Foods in Bangladesh and Australia: A Comparative Perspective on Consumer Protection

The statutory laws concerning food safety, which allow the consumers affected by unsafe foods to claim compensation for their loss or damage in Bangladesh, are flawed in several respects. These flaws are argued to have harmful impacts on consumer protection. The ineffective legislation in the absence of application of the common law principles of negligence has left the consumers virtually helpless in securing remedies for their injuries. This article endeavors to critically examine the ambiguities and shortcomings in the Consumer Rights Protection Act 2009 (Bangladesh) looking through the prisms of the Australian Consumer Law 2010 and relevant case law from major common law jurisdictions. It discovers a number of weaknesses in the legislation of Bangladesh and provides specific suggestions for strengthening the civil liability provisions from the perspective of consumer protection by preventing their contraventions and providing adequate compensation.     

2-Fatty Acrylic Acids: New Highly Derivatizable Lipophilic Platform Molecules

This paper reports the incorporation of an alpha-methylene unit into fatty acid skeletons. Since the new olefin is conjugated with the carboxylate, it is susceptible to 1,4-(Michael) additions. We have used multifunctional thiols and amines for additions at the methylene. The resulting products possess clusters of functionality grouped at one end of a hydrophobic tail. These structural patterns will be of use in the design of new types of bio-based surfactants and polymers. One particularly promising pattern of functionality that can be obtained through oxidation and reduction chemistry is a 2-fatty 1,2,3-propanetriol, or a lipophilized glycerol moiety.     

Reductionin Listeria monocytogenes,Salmonella enterica and Escherichia coli O157:H7 in vitro and on tomato by sophorolipid and sanitiser as affected by temperature and storage time

Increased consumption of produce by consumers has been attributed to perceived health benefits of postharvest produce. Pathogen control is crucial because periodic occurrences and contamination of tomato and leafy greens have exacerbated food safety risks for consumers. We investigated the effects of temperatures (5 and 25 °C), storage time (30 min and 24 h) for inactivation of Listeria monocytogenes, Salmonella enterica and Escherichia coli O157:H7 by sophorolipid (SL‐p) produced fermentatively using palmitic acid as a co‐substrate at different concentrations in vitro. Reduction in pathogenic bacteria on grape tomato by SL‐p, sanitiser (Lovit) and combinations of SL‐p and sanitiser was determined. Temperature and storage time significantly (P < 0.05) affected pathogen inactivations by SL‐p as pathogen reductions were greater at 25 °C and 24 h than at 5 °C and 30 min of storage. L. monocytogenes was the most sensitive to SL‐p treatment as reductions of 5 log relative to untreated controls were attained at 0.12% of SL‐p. Significant reductions in S. enterica (1.91–3.85 logs) and E. coli O157:H7 (0.87–4.09 logs) were recorded at 2–5% of SL‐p. Lower populations of Salmonella and E. coli O157:H7 were inactivated than L. monocytogenes. On grape tomato, pathogen populations inactivated increased at higher SL‐p levels at 25 °C. Sanitiser and sanitiser + SL‐p reduced bacterial populations on tomato by 5.29–5.76 logs and 0.71–3.3.66 logs, respectively. These results imply the interactions of temperature, storage time and SL‐p significantly (P < 0.05) affected pathogen strain reductions. The combination of SL‐p with sanitiser led to synergistic effect on E. coli O157:H7, but not L. monocytogenes and S. enterica.     

When does length cause the word length effect?

The word length effect, the finding that lists of short words are better recalled than lists of long words, has been termed one of the benchmark findings that any theory of immediate memory must account for. Indeed, the effect led directly to the development of working memory and the phonological loop, and it is viewed as the best remaining evidence for time-based decay. However, previous studies investigating this effect have confounded length with orthographic neighborhood size. In the present study, Experiments 1A and 1B revealed typical effects of length when short and long words were equated on all relevant dimensions previously identified in the literature except for neighborhood size. In Experiment 2, consonant–vowel–consonant (CVC) words with a large orthographic neighborhood were better recalled than were CVC words with a small orthographic neighborhood. In Experiments 3 and 4, using two different sets of stimuli, we showed that when short (1-syllable) and long (3-syllable) items were equated for neighborhood size, the word length effect disappeared. Experiment 5 replicated this with spoken recall. We suggest that the word length effect may be better explained by the differences in linguistic and lexical properties of short and long words rather than by length per se. These results add to the growing literature showing problems for theories of memory that include decay offset by rehearsal as a central feature. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Membrane as Solid∕Liquid Separator and Air Diffuser in Bioreactor

A bench-scale pilot plant was operated to evaluate the potential of using microfiltration hollow fiber membrane modules as an air diffuser and solid∕liquid separator in an alternate cycle within a bioreactor treating domestic wastewater. Two modules capable of air backwashing were immersed in a bioreactor. Compressed air backwashing and filtration by suction were effected alternatively. The experimental results reveal that application of the air backwashing technique to submerged membrane modules is capable of not only declogging the membranes but also of aerating the mixed liquor. Thus, better filtration flux rate and aeration without a separate aeration device were attained simultaneously. It was also noted that the introduction of an anoxic zone enhanced the removal of nitrogen. In addition, operation at low hydraulic retention time with high sludge concentration and the absence of a sedimentation tank indicate considerable savings on the plant area.     

Error probability of fast frequency hopping spread spectrum withBFSK modulation in selective Rayleigh and selective Rician fadingchannels

The performance of noncoherent reception in fast frequency hopped spread-spectrum (FFH-SS) communication systems operating through noisy, fading multipath channels is investigated. Systems operating with binary frequency-shift keying (BFSK) modulation and noncoherent demodulation are examined under the assumption of very slow fading. These analyses demonstrate the frequency hopping benefits in selective channels. Expressions are derived for the bit error rate in the context of selective Rayleigh and selective Rician fading channels, as a function of channel and system parameters     

Influence of Silicification on the Structural and Biological Properties of Buffer‐Mediated Collagen Hydrogels

A buffer‐mediated gelation route for collagen hydrogels that allows the formation of homogeneous composite and hybrid materials with various silica sources (i.e., colloidal silica and soluble silicates) at high concentration (up to 25 × 10^?3 M ) is described. Most significant improvement in rheological properties and proliferation of primary adult human dermal fibroblasts was obtained for the silicate‐based hybrid materials. A similar trend was observed in composite materials incorporating 14 nm SiO₂ nanoparticles, although to a much lesser extent, whereas larger colloids (80 and 390 nm) did not significantly impact mechanical stability and cell behavior. Modification of 80 nm particles surface with amine groups weakens the collagen‐mineral interface, resulting in the decrease of material stability and leading to particle aggregation during the course of cell proliferation experiments.     

Surge characteristics of a twisted pair

We used the method of moments (MoM), which is a numerical electromagnetic field computation method, to study the surge characteristics of twisted pair single‐phase electric power lines. The results show that wires stranded with less than several turns per meter have almost the same surge characteristics as parallel lines, but the surge impedance decreases in tens of % when the number of strands increases. To verify the simulation results, we measured the surge characteristics of a model line of twisted pair experimentally, and there is good accordance between them. It is possible to simulate the surge in twisted pair covered with polymer dielectric insulators by MoM. Moreover, we studied the surge characteristics of twisted pair which is inserted into a metal tube. According to the results, the effect of the strand is smaller than that in free space without the metal pipe. There are two propagation modes in common mode: fast surge and slow surge. Few influences of the number of strands on the surge velocity occur in the fast propagation surge, but the increase of the surge impedance and the slowdown of the propagation speed are caused by twining in the slow propagation mode. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(3): 1–9, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20737