Profiles of carotenoids during post-climacteric ripening of some important cultivars of banana and development of a dry product from a high carotenoid yielding variety

Since vitamin A deficiency is prevalent in many developing countries, we sought to focus research on local, affordable and well-accepted sources of provitamin A carotenoids. As dessert bananas are consumed fresh round the year and processed as products, this study investigated whether post-climacteric biochemical changes are linked to carotenoid degradation in four Indian varieties, one commercial (Cavendish, AAA), one Red banana (genome AAA) and two locally-important ones (genome AAB). Despite large differences in their ripening characteristics, textural loss was lesser in AABs than AAAs. High levels of carotenoids (21.0 μg/g FW), β-carotene (9.14 μg/g FW) and α-carotene (9.32 μg/g FW) were found in Red banana accounting for retinol activity equivalent of 114 μg/100 g FW. The carotenoid levels were lower in two local varieties and lowest in Cavendish, with no post-climacteric loss. Dry grits, prepared using Red banana pulp, milk powder and sugar, retained about 70% carotenoids and appeared useful in confectionaries.     

The suppression of eicosanoid synthesis by peritoneal macrophages is influenced by the ratio of dietary docosahexaenoic acid to linoleic acid

The efficacy of docosahexaenoic acid (DHA) in suppressing eicosanoic synthesis by peritoneal macrophagesin vivo was influenced by the relative amount of dietary DHA when linoleic acid (LA) was held constant. Increasing DHA from 0 to 37% of the fatty acids in diets containing 10 weight % fat (of which LA was 40%) caused an eleven-fold increase in the DHA content of macrophages. Limited retroconversion of DHA to eicosapentaenoic acid was observed. Macrophages in animals consuming DHA synthesized significantly lower amounts of leukotriene E₄, prostaglandin E₂ and 6-keto prostaglandin F_1α in vivo upon stimulation with zymosan. The maximum inhibition of eicosanoid synthesis was observed when the dietary DHA/LA ratio was 0.16 and no further inhibition occurred when the ratio was increased up to 0.81.     

A Rectangular SRR Switched Slotted Microstrip Patch for Frequency Diversity Application

Planar antenna with a specific resonant mode is essential to meet the diversity demand for wireless communication. This paper presents modeling and experimental validation of a microstrip antenna design in which multiple resonant frequencies are excited based on different negative permeability response of the rectangular split ring resonator (SRR). The antenna geometry consists of a slotted patch with split ring resonator loaded between its two arms. The patch was fabricated on FR-substrate of relative permittivity ε_r?=?4.4, and has a size of 30.5 mm?×?34 mm. In the antenna desing, PIN diodes connect the outer ring and inner ring resonator of the SRR to the adjacent arms of the patch. Under various bias conditions, quad-band resonance was observed at 2.07 GHz, 2.11 GHz, 2.31 GHz, and 2.46 GHz. The measured S₁₁ results are found comparable to the simulated data, and demonstrate proper functioning of the proposed antenna with stable gain and radiation patterns.     

Enzymatic acidolysis in hexane to produce n−3 or n−6 FA-enriched structured lipids from coconut oil: Optimization of reactions by response surface methodology

Response surface methodology is a statistical design that helps one to determine optimal conditions for an enzyme-catalyzed reaction by performing a minimal number of experiments. This methodology was adapted for modifying coconut oil TAG by using lipase-catalyzed acidolysis in hexane to incorporate n−3 or n−6 PUFA. FFA obtained after hydrolysis of cod liver oil and safflower oil were used as acyl donors. Immobilized lipase, Lipozyme IM60, from Rhizomucor miehei was used for catalyzing the reaction. The reaction conditions—substrate molar ratio, incubation time, and temperature—were optimized. The experimental data were fitted to a response function based on the central composite rotatable design. The optimal conditions generated from models indicated that maximal incorporation of n−3 PUFA occurred at a 1∶4 molar ratio of TAG/FFA when incubation was carried out for 34 h at 54°C. Similarly, maximal incorporation of n−6 FA was predicted at a 1∶3 molar ratio of TAG/FFA when incubated for 48.5 h at 39°C. Experiments conducted at optimized conditions predicted by the equation obtained from response surface methodology yielded structured lipids with 13.65 and 45.5% of n−3 and n−6 FA, respectively. These values agreed well with that predicted by the model. The reactions were also scaled up to 100 g levels in batch reactors with the incorporation level of n−3 and n−6 fatty acids agreeing closely with that observed when the reactions were carried out at lab scale (100 mg). These studies indicated that response surface methodology is a useful tool in predicting the conditions for incorporating desired levels of specific FA during the synthesis of structured lipids.     

Speech recognition with improved support vector machine using dual classifiers and cross fitness validation

In this research, a new speech recognition method based on improved feature extraction and improved support vector machine (ISVM) is developed. A Gaussian filter is used to denoise the input speech signal. The feature extraction method extracts five features such as peak values, Mel frequency cepstral coefficient (MFCC), tri-spectral features, discrete wavelet transform (DWT), and the difference values between the input and the standard signal. Next, these features are scaled using linear identical scaling (LIS) method with the same scaling method and the same scaling factors for each set of features in both training and testing phases. Following this, to accomplish the training process, an ISVM is developed with best fitness validation. The ISVM consists of two stages: (i) linear dual classifier that finds the same class attributes and different class attributes simultaneously and (ii) cross fitness validation (CFV) method to prevent over fitting problem. The proposed speech recognition method offers 98.2% accuracy.     

Lipid composition and prostaglandin synthesis in mouse lung microsomes: Alterations following the ingestion of menhaden oil

Three groups of male mice were fed a normal diet or a semisynthetic diet containing either 10% hydrogenated coconut oil (CO group) or 10% menhaden oil (MO group) for two wk. The synthetic diet altered the fatty acid composition of lung microsomal lipids. Mice ingesting menhaden oil contained greater amounts of eicosapentaenoic acid (20∶5 n−3), docosapentaenoic acid (22∶5 n−3) and docosahexaenoic acids (22∶6 n−3) and decreased amounts of n−6 fatty acids such as arachidonic and adrenic. Synthesis of prostaglandin E₂ and prostaglandin F_2α from exogenous arachidonic acid was significantly depressed in n−3 fatty acid-enriched lung microsomes. These studies indicated that dietary fish oil not only alters the fatty acid composition of lung microsomes but also lowers the capacity of lungs to synthesize prostaglandins from arachidonic acid.     

Modelling and analysis of resource scheduling in restructured power systems considering wind energy uncertainty

Concerns over rapid transformation of global climate patterns resulted in wide deployment of renewable energy sources especially wind energy. However, intermittent nature of wind energy makes resource scheduling aspect of system operator more complex. The emerging deregulation policies have added to the complexity of scheduling problem. Therefore, treating and scheduling of wind energy on deterministic basis would result in non-optimal energy dispatch and increased operation cost over scheduling horizon. This paper focuses on optimal scheduling methodology of wind energy in day ahead market (DAM) considering expected costs due to wind uncertainty in real time (RT) spot market under deregulated market structure. This paper introduces various possible costs, namely, spot market compensation cost, additional reserve cost and rescheduling cost applicable to deviation in scheduled power from DAM to spot market. The costs can be derived from front-end information of DAM, historical and statistical estimate of RT market conditions. The effectiveness of proposed methodology is examined using IEEE 30 bus system with thermal and wind energy generators. In addition, sensitivity analysis is performed to examine the effect of incentive margin on DAM scheduling. Simulation results are presented, discussed and affirmed the effectiveness of proposed scheduling methodology.     

Effect of Heating Rates on the Synthesis of Al2O3–SiC Composites by the Self-Propagating High-Temperature Synthesis (SHS) Technique

Various aspects of in situ formation of Al₂O₃–SiC composites by the self-propagating high-temperature synthesis (SHS) technique have been investigated using thermal analyses (TG/DTA) of a powder mixture (4Al, 3SiO₂, 3C) and pellets in an argon atmosphere at different heating rates. Both the reaction initiation and peak temperatures are found to increase with the heating rates. At lower heating rates, the powder samples do not reveal any exothermic peak possibly because of poor reactivity and sluggish exothermic reaction. The appearance of exothermic peaks in the DTA plots after melting of aluminum indicates reduction of silica by liquid aluminum. Conversion of aluminum is found to decrease marginally with an increase in heating rates. The apparent activation energy of the process compares well with the interdiffusion activation energy of silicon and oxygen, indicating that oxygen diffusion in Si formed at the reaction front may be the rate-controlling factor for this SHS process. From SEM studies it appears that the formation of SiC whiskers is through liquid-phase mass transfer.     

Design,simulation and fabrication of LTCC-based microhotplate for gas sensor applications

Microsystem Technologies - This paper presents the design, simulation and fabrication of LTCC-based isothermally interconnected microhotplate. A thermal electric finite element analysis is used to...