Application of factorial design in optimization of anion exchange resin based methylation of vegetable oil and fats

A simple, rapid and fairly selective method for the preparation of fatty acid methyl esters (FAMEs) based on anion exchange resin Amberlite IRA-904 catalyzed transesterification of vegetable oil/fat with iodomethane has been described. The vegetable oil and animal fats used were sunflower oil, palm oil, vanaspati (hydrogenated vegetable oil), olive oil, tallow and butter. A Plackett–Burman factorial experimental design was used as a multivariate strategy for the evaluation of the effects of varying several variables at once. The effects of five different variables amount of resin, strength of sodium hydroxide, volume of iodomethane, heating time and temperature of thermostatic water bath, on the yield of fatty acid methyl esters (FAMEs) have been investigated. From these studies, certain variable showed up as significant, and they were optimized by a using 2³ + star central composite design, which involved 16 experiments. The best conditions for transesterification reaction were as follows: amount of resin 2 g, strength of sodium hydroxide 0.25 N, volume of iodomethane 400 µl, heating time 2 min at 70 °C. A standard IUPAC method was used to prepare FAMEs from vegetable oil/fats for comparative purpose. Finally samples of oil/fat obtained from both methods were analysed by Gas liquid chromatography. Analytical results for the FAMEs by resin based proposed method, and conventional IUPAC method showed a good agreement, thus indicating the possibility of using Amberlite IRA-904 based transesterification instead of intensive treatments inherent with the conventional time-consuming methods.

Industrial relevance

Fatty acids are the main components of edible oil and fats, therefore determination of fatty acid composition is so far one of the important parameters for quality evaluation and nutritional value determination of edible oil and fats. The analysis of fatty acid is usually carried out by Gas liquid chromatography (GLC) after conversion of volatile fatty acid methyl esters (FAME) although other ester may be prepared for specific purpose.The endeavor of present work was to improve the FAMEs preparation method, proposing the development of anion exchange resin Amberlite IRA-904 based transesterification of edible oil/fat with iodomethane as alkylating reagent. The present method besides being rapid and reproducible avoids the use of classical saponification, washing of esters and solvent extraction step.     

Lowpass digital filters with linear phase

A method of synthetising lowpass recursive digital filters is given in the letter. The method relies on the properties of orthogonal functions on the z plane and the impulse response of an ideal lowpass linear phase filter. Considerable saving in computation and storage appears to have been achieved by this method compared with the nonrecursive (with window functions) truncation method.     

Semiconductor Laser in Distributed Optical Feedback Regime

Wireless Personal Communications - In this work, we first analyse the behaviour of semiconductor laser in the presence of weak-to-moderate feedback from a single (lumped) and double external cavity...     

On sequential watermark detection

This paper introduces a new watermark detection paradigm based on sequential hypothesis testing. It is shown that this framework leads to significantly faster watermark detection compared with more commonly used detectors. Fundamental issues such as joint design of watermark encoding and detection are addressed within this framework. Theoretical results are validated through experiments. On an average, the proposed framework can detect watermarks 70% faster than popular detectors. We believe that this could potentially have significant impact on many applications such as video watermark detection and searching for watermarks in a large database of digital contents.     

On ordering color maps for lossless predictive coding

Linear predictive techniques perform poorly when used with color-mapped images where pixel values represent indices that point to color values in a look-up table. Reordering the color table, however, can lead to a lower entropy of prediction errors. In this paper, we investigate the problem of ordering the color table such that the absolute sum of prediction errors is minimized. The problem turns out to be intractable, even for the simple case of one-dimensional (1-D) prediction schemes. We give two heuristic solutions for the problem and use them for ordering the color table prior to encoding the image by lossless predictive techniques. We demonstrate that significant improvements in actual bit rates can be achieved over dictionary-based coding schemes that are commonly employed for color-mapped images.     

"Eyewitness researchers as experts in court: responsive to change in a dynamic and rational process": Comment.

Responds to the comments by M. L. McCullough (see record 2002-12932-018) on the original article (see record 2001-17140-001) which discussed eyewitness testimony. The current author states that McCullough's commentary rests on a foundation of assumptions that were both na?ve and erroneous. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reinstating the Purpose of Planning within New Zealand's Resource Management Act

This paper reviews recent changes in the direction of planning in New Zealand within the framework of the Resource Management Act (RMA). It is argued that the RMA enacted in 1991 is potentially a progressive planning statute. Its legislative intent embraces sustainability ethical values and norms as a basis for decision making in the context of a property owning democracy. However, the potential of the Act has been compromised during the last 10 years by attempts by the previous government and New Right interest groups to force a narrower interpretation of the Act's purpose as stated in Section 5. These attempts have been challenged by recent Court decisions.     

Time saving modified BCR sequential extraction procedure for the fraction of Cd, Cr, Cu, Ni, Pb and Zn in sediment samples of polluted lake

The mobility, availability and persistence of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in contaminated lake sediment samples were evaluated by means of sequential extraction scheme, proposed by the Community Bureau of Reference protocol (BCR). The metal content in the extracts was measured by atomic absorption spectrometry. The precision and accuracy of the proposed procedure were evaluated by using a certified reference material BCR 701. The maximum recoveries for heavy metals (HMs) were observed for all three steps of BCR protocol at 32h total shaking period instead of previously reported 51h, with p>0.05. The lixiviation tests (DIN 38414-S4) were used to evaluate the leaching of HMs from sediment samples and it was observed that levels of water extractable HMs were low as compared to those values obtained by acid-soluble fraction of the BCR protocol.     

Effect of Silicone Nano,Nano/Micro and Nano/Macro‐Emulsion Softeners on Color Yield and Physical Characteristics of Dyed Cotton Fabric

The study of silicone nano‐emulsions and softeners to alter physical properties of undyed cotton fabric has recently gained a substantial interest. However, systematic investigation of silicon nano‐emulsion softeners on dyed cotton fabric has not so far been conducted. This paper deals with the application of silicone nano‐, micro‐, and macro‐emulsion softeners, and combinations of nano/micro and nano/macro, on dyed cotton fabric. We report the effect of silicon nano/micro‐ and nano/macro‐emulsion softeners on color yield and physical characteristics of dyed cotton fabric. All bleached fabrics were dyed with CI Reactive Black 5 and then treated with known concentrations of silicone softeners by the pad‐dry method. The silicone nano‐emulsion was combined with micro‐ and macro‐emulsion softeners using blending ratios of nano/micro (1:1) and nano/macro (1:1). Treated fabrics were compared in terms of physical properties such as fabric handling, wrinkle recovery angle, bending length, abrasion resistance and tensile strength. The color changes were evaluated by color yield (K/S) values and total color difference (ΔE_cmc). The results revealed that the silicon nano‐emulsion had better physical properties than micro‐, macro‐ and combination nano/micro‐ and nano/macro‐emulsion softeners. Among all treated samples, nano‐emulsion softeners showed better ΔE_cmc values. Scanning electron microscopy analysis suggests that the fiber morphology of treated fabrics was very smooth and uniform.