A Novel Low Complexity Technique for Minimization of PAPR in Multicarrier-CDMA Systems Using Peaks Comparison and Subgroups Samples Scaling

Wireless Personal Communications - Excessive peak to average power ratio (PAPR) of the communicated signal is a serious problem of the multicarrier-CDMA system. Most popular PAPR minimization...     

On the reducibility of centrosymmetric matrices — Applications in engineering problems

The structure inherent to the centrosymmetric matrices is exploited to obtain factorization results leading to significant computational savings in many engineering applications. Several interesting properties of the matrices are discussed with a view toward algorithm computational complexity. It is shown that the multiplicative complexity involved in the process of principal component (eigen-value/eigenvector) extraction, and in the evaluation of the determinant and inverse of such matrices, can be reduced by nearly 75% by employing the results presented here. The theory presented hereunifies andgeneralizes previous computationally efficient results onseveral specialized generalized centrosymmetric matrices; for example, the class of symmetric centrosymmetric (or doubly symmetric) matrices is shown to be a special case of the class of centrosymmetric matrices, and since the results obtained here are applicable over the field of complex numbers, the factorization results available for centrosymmetric matrices are readilyextended to the complex field. The centrosymmetric matrices play an important role in a number of areas such as pattern recognition, antenna theory, mechanical and electrical systems, and quantum physics. Specific examples of pattern recognition feature selection, a uniform linear antenna array, vibration in structures, and the quantummechanical oscillator are discussed to demonstrate that the theory developed here has a wide range of applications. In addition, certain specialized cases of the centrosymmetric matrices have, in the past, proved their indisputable usefulness in the areas of communication theory, digital filters, linear systems, linear prediction, and speech analysis.Research supported by NSERC Grant A0912.     

A novel approach for evaluation of polymeric interface materials for chemical sensors using alternate indirect methods

The heart of a chemical sensor based on bulk or surface acoustic wave devices is a polymer‐coated piezoelectric substrate that selectively sorbs and concentrates the target analyte vapors. The development of such sensors often necessitates the screening and evaluation of suitable polymeric interface materials meeting the specified sensitivity and selectivity toward the analytes of interest. The magnitude and dynamics of sorption–desorption of the vapors in the polymer and the extent of polymer–vapor interactions largely determine the performance of a sensor. The standard protocol used for the purpose is rather tedious, involving the generation and calibration of individual analyte vapors, with stringent control on temperature, humidity, and test parameters. This article outlines four different alternative techniques based on mass uptake of the analyte vapors, on its partitioning in polymers, or both, which in combination can determine the characteristics of an interface material used for coating a piezoelectric substrate in acoustic wave‐based chemical sensors. These methods were applied to poly(ethylene maleate), a representative interface material. The analytes ranged from volatile organic chemicals to sarin—a chemical warfare agent—and its simulant, dimethyl methylphosphonate. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3428–3432, 2004     

Rats fed linseed oil in microemulsion forms enriches the cardiac sarcoplasmic reticulum lipids with docosahexaenoic acid and lower calcium transport

The effect of feeding rats with whey protein or lipoid microemulsion of n-3 rich linseed oil (LSO), and n-6 rich sunflower oil (SNO) compared to native or microemulsion forms of each oil for 60 days on fatty acid composition, Ca²⁺Mg²⁺ ATPase, Ca²⁺ uptake and membrane fluidity of rat cardiac sarcoplasmic reticulum (SR) were assessed. Rats consuming LSO in lipoid microemulsion showed higher levels of ALA (18:3, n-3) conversion to DHA (22:6, n-3) when compared to rats given LSO in native form. Compared to all other dietary treatments, the alterations in the n-6/n-3 PUFA composition of SR of rats given LSO in lipoid microemulsion effected the greatest changes in Ca²⁺Mg²⁺ ATPase activity and Ca²⁺ uptake which effectively reduced Ca²⁺ transport. Therefore, the LSO in lipoid microemulsion confers similar heart healthy fatty acid compositional and calcium transport changes and potentially anti-arrhythmic effects similar to fish oils.     

Utilization and value addition of copper tailing as an extender for development of paints

The present study deals with characterization of copper tailing waste, test for possibilities of hazards and its potential reuse as an extender in paints. The waste is a siliceous material containing aluminum oxide, iron oxide and sulphate in significant concentrations. In the primary stage waste is acidic in nature, which makes it unsuitable for paint. This acidity is removed from the waste by simple sieving and grinding. The prepared mass was characterized for basic properties of an extender like oil absorption, specific gravity, pH, etc. Toxicity studies were also conducted in term of leaching of heavy metals by standard techniques (USEPA using TCLP). Properties of the prepared paint's film in terms of hardness, adhesion, resistance to abrasion, resistance to impact, resistance to corrosion (under humidity and salt fog), etc. were evaluated and compared with a similar formulation of conventional extender and found satisfactory. Results from the experiments indicated that developed extender is environmentally clean and cost-effective.     

Effect of blending and lipase catalyzed interesterification reaction on the cholesterol lowering properties of palm oil with rice bran oil in rats

The effect of feeding blended and interesterified oils containing palm oil (PO) and rice bran oil (RBO) on serum and liver lipids was evaluated in rats. The PO and RBO were blended to contain saturated, monounsaturated and polyunsaturated fatty acids in the proportion of 1:1.5:1. The blended oil was subjected to transesterification reaction using immobilized lipase, lipozyme IM‐RM. Rats were fed a diet containing blended or interesterified oils for 8 weeks. Rats fed PO showed significantly higher levels of cholesterol in serum and liver as compared to those given RBO, blended oil of PO with RBO or interesterified oil. Rats fed blended oils showed a significant decrease in serum cholesterol by 51% compared to rats fed PO. Feeding interesterified oil to rats resulted in decrease in serum cholesterol by 56% compared to rats fed PO, which was 10% lower compared to that observed in rats given blended oil. The present study indicated that a combination of PO with RBO can significantly lower serum lipids in rats as compared to those given diet containing PO alone.     

Uptake of α-Linolenic Acid and Its Conversion to Long Chain Omega-3 Fatty Acids in Rats Fed Microemulsions of Linseed Oil

The present work was designed to prepare linseed oil (LSO) microemulsion and explore the possibility of enhancing the uptake and utilization of α-linolenic acid (ALA) present in LSO. The bioavailability of encapsulated LSO as against native oil was monitored in rats by measuring the uptake in vitro using the intestinal everted sac model and in-vivo administration of microemulsions of LSO to rats for a period of 30?days. Microemulsions were prepared by using different binding materials such as gum acacia, whey protein and lipoid. When LSO was encapsulated with gum acacia, whey protein and lipoid, the levels of ALA uptake into intestinal sacs was increased by 6, 17 and 28?% as compared to oil given without encapsulation. EPA and DHA were not observed in the oil absorbed by intestinal everted sacs when given as emulsions with gum acacia or whey protein. When LSO was given as microemulsions with lipoid, EPA?+?DHA was observed in oil absorbed by intestinal sacs. Similarly when LSO was given as a lipoid emulsion by intubation to rats, the EPA and DHA in serum lipids were found to be 41 and 34?μg/ml, respectively while rats given LSO without encapsulation contained EPA and DHA at 9.1 and 8.8?μg/ml, respectively. Similar changes in omega-3 fatty acid content in liver lipids were observed when LSO was given as a microemulsion with lipoid. This study indicated that ALA was taken up and metabolized to long chain omega-3 PUFA when given as microemulsion with lipoid.     

Performance of Reduced State S–T Trellis Coded MC-CDMA Systems

In this paper, performance of reduced state space-time trellis coded multi carrier code division multiple access (STTC-MC-CDMA) system is evaluated and compared with the performance of original state STTC-MC-CDMA system. The optimum decoding scheme, i.e., maximum likelihood sequence estimation is employed which uses Viterbi algorithm for decoding STTC code. To simplify the implementation of the STTC decoder, the number of states is reduced by reducing the constraint length of the STTC encoder using generating function technique. In this technique, the generator matrix of STTC code is minimized to reduce the number of states of S–T trellis decoder. It is observed that the performance loss in terms of frame error rate of the reduced state STTC-MC-CDMA system is negligible compared to the original state STTC-MC-CDMA system. It is also noted that by using the reduced state technique the STTC decoder can be made faster since it is having lower computational complexity.     

Microbial inactivation by high pressure processing: principle,mechanism and factors responsible

Food Science and Biotechnology - High-pressure processing (HPP) is a novel technology for the production of minimally processed food products with better retention of the natural aroma, fresh-like...