Hydrogenation of unsaturated fatty acid methyl esters with diimide from hydroxylamine-ethyl acetate

Methyl esters of 10-undecenoic, oleic, linoleic and castor oil fatty acids were hydrogenated with hydroxylamine-ethyl acetate reagent under nitrogen, without change in position and configuration of double bonds. The fatty acid ester was also found to participate in the generation of diimide. No hydrazide was formed.     

Preparation and surface-active properties of the sodium soaps,mono- and diethanolamides and diol and triol sulfates of cycloaliphatic C21 Di- and C22 Tricarboxylic acids

Cycloaliphatic C₂₁ di- and C₂₂ tricarboxylic acids were prepared by the Diels-Alder reaction of dehydrated castor oil (DCO) fatty acids (containing 48% conjugated and 42% nonconjugated dienes) with acrylic and fumaric acids, respectively. The reaction temperature, time, catalyst concentration, and mole ratio of reactants were varied to get maximum yields of the di- and tricarboxylic acids. The unreacted DCO fatty acids were removed from the products by partition between aqueous methanol and n-hexane. The products were converted to methyl esters and characterized as the substituted cyclohexene derivatives before and after dehydrogenation with Pd/C in xylene, hydrogenation with Pd/C in decalin and oxidation with periodate-permanganate reagent and by mass and proton nuclear magnetic resonance spectrometry. The acids were converted to sodium soaps, mono- and diethanolamides and the corresponding diol and triol sulfates, and the resulting products were evaluated for their surface-active properties. The sodium soaps showed better calcium tolerance and poorer foaming power than sodium oleate. The diethanolamides were inferior to lauroyl diethanolamide in wetting and emulsifying power. The monoethanolamides were better than the respective diethanolamides and lauroyl diethanolamide in wetting property. The diol and triol sulfates were poorer in wetting and emulsifying ability and better in calcium tolerance than sodium lauryl sulfate.     

A bubbling bed model for elutriation of fine particles

A model for elutriation of fine particles from a bubbling dense fluidised bed is developed, assuming that fine particles percolate into the bubble along with the through flow gas and move into the freeboard along with the bubble. Particles whose terminal velocity is less than the superficial gas velocity are considered to elutriate out of the freeboard. The equations developed are compared with some recent data and agreement is good.     

Reduction of unsaturated fatty acids and fatty alcohols with diimide from hydroxylamine-ethyl acetate

Hydroxylamine has been recently found to react with ethyl acetate to generate diimide in situ. This reaction was used to reduce 10-undecenoic, oleic, linoleic, stearolic, concentrates of ricinoleic, cyclopentene and cyclopropene fatty acids (FA), dehydrated castor oil FA, 10-undecen-1-ol, oleyl alcohol and castor fatty alcohols. Unsaturated FA and their corresponding alcohols reacted in a similar manner. Terminally unsaturated, cyclopropene and cyclopentene FA were more reactive than oleic acid, which, in turn, was more reactive than hydroxymonoenoic acids. Conjugated dienoic FA reduced faster than nonconjugated dienoic acids. Partial hydrogenation using this reagent is particularly advantageous in determining geometry and the position of double bonds in the polyunsaturated FA, as it can be carried out in the absence of oxygen or oxidizing agents unlike hydrazine reductions.     

Laboratory Thin-Film Encapsulation of Air-Sensitive Organic Semiconductor Devices

We present an approach, which is compatible with both glass and polymer substrates, to in-laboratory handling and intra-laboratory shipping of air-sensitive organic semiconductors. Encapsulation approaches are presented using polymer/ceramic and polymer/metal thin-film barriers using commercially available materials and generally available laboratory equipment. A technique for depositing an opaque vapor barrier, a transparent vapor barrier, and an approach to storing and shipping air-sensitive thin-film organic semiconductor devices on both polymer and glass substrates are presented. Barrier performance in air was tested using organic light-emitting diodes (OLEDs) as test devices. The half-life performance of OLEDs on plastic substrates in air exceeded 700 h, and that on glass exceeded 500 h. Commercially available heat-seal barrier bag systems for device shipping and storage in air were tested using a thin film of metallic calcium to test water permeation. More than four months of storage of a metallic calcium film in a heat-sealed foil bag was demonstrated in the best storage system. These approaches allow for the encapsulation of samples for longer duration testing and transportation than otherwise possible.     

Coded excitation for infrared non-destructive testing of carbon fiber reinforced plastics

This paper proposes a Barker coded excitation for defect detection using infrared non-destructive testing. Capability of the proposed excitation scheme is highlighted with recently introduced correlation based post processing approach and compared with the existing phase based analysis by taking the signal to noise ratio into consideration. Applicability of the proposed scheme has been experimentally validated on a carbon fiber reinforced plastic specimen containing flat bottom holes located at different depths.     

The effect of deferoxamine on ciprofibrate-induced hepatocarcinogenesis in the rat

A 74-year-old woman was hospitalised for pleuro-pneumonia of the right base. The chest x-ray showed the presence of a right paratracheal opacity which persisted during the course of the infectious episode. A computed tomographic scan of the thorax showed a voluminous anterior mediastinal mass which compressed the trachea without invading it. Surgical excision enabled the ablation of a tumour which was haemorrhagic and the histological examination established a diagnosis of cystic parathyroid adenoma. At anytime did the patient present either clinical symptoms or biochemical signs suggesting primary hyperparathyroidism.     

Development challenges under the Clean Development Mechanism (CDM)—Can renewable energy initiatives be put in place before peak oil?

The “Sustainable Development” aspect of the Clean Development Mechanism (CDM) under the Kyoto Protocol is examined, with regard to its current impact on crucial developmental issues.     

Bayesian networks for supporting query processing over incomplete autonomous databases

As the information available to naïve users through autonomous data sources continues to increase, mediators become important to ensure that the wealth of information available is tapped effectively. A key challenge that these information mediators need to handle is the varying levels of incompleteness in the underlying databases in terms of missing attribute values. Existing approaches such as QPIAD aim to mine and use Approximate Functional Dependencies (AFDs) to predict and retrieve relevant incomplete tuples. These approaches make independence assumptions about missing values—which critically hobbles their performance when there are tuples containing missing values for multiple correlated attributes. In this paper, we present a principled probabilistic alternative that views an incomplete tuple as defining a distribution over the complete tuples that it stands for. We learn this distribution in terms of Bayesian networks. Our approach involves mining/“learning” Bayesian networks from a sample of the database, and using it to do both imputation (predict a missing value) and query rewriting (retrieve relevant results with incompleteness on the query-constrained attributes, when the data sources are autonomous). We present empirical studies to demonstrate that (i) at higher levels of incompleteness, when multiple attribute values are missing, Bayesian networks do provide a significantly higher classification accuracy and (ii) the relevant possible answers retrieved by the queries reformulated using Bayesian networks provide higher precision and recall than AFDs while keeping query processing costs manageable.