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Microwave Treatment (microwave + treatment)
Selected AbstractsA Combined Process of In Situ Functionalization and Microwave Treatment to Achieve Ultrasmall Thermal Expansion of Aligned Carbon Nanotube,Polymer Nanocomposites: Toward Applications as Thermal Interface MaterialsADVANCED MATERIALS, Issue 23 2009Wei Lin Ultrasmall thermal expansion of aligned carbon nanotube,epoxy composites at temperatures below and above the glass transition is achieved by a novel combined process of in situ functionalization and microwave treatment. Carbon nanotube,polymer interfacial bonding is the key to the reduced thermal expansion, enhanced storage modulus, and improved thermal conductivity. [source] Effect of different cooking methods on the antioxidant activity of some vegetables from PakistanINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2008Bushra Sultana Summary The effects of different cooking methods (boiling, frying and microwave cooking) on the antioxidant activity of some selected vegetables (peas, carrot, spinach, cabbage, cauliflower, yellow turnip and white turnip) were assessed by measuring the total phenolic contents (TPC), reducing power and percentage inhibition in linoleic acid system. TPC (gallic acid equivalents g/100 g of dry weight) and reducing power of the methanolic extracts of raw-, microwaved-, boiled- and fried vegetables ranged 0.333,2.97, 0.52,2.68, 0.48,2.08, 1.00,2.02 and 0.391,2.24, 0.822,1.10, 0.547,1.16, 0.910,4.07, respectively. The level of inhibition of peroxidation ranged 71.4,89.0, 66.4,87.3, 73.2,89.2 and 77.4,91.3%, respectively. Antioxidant activity of the vegetables examined was appreciably affected because of varying cooking treatments. TPC of vegetables, generally, decreased by boiling, frying and microwave cooking. There was a significant (P < 0.05) increase in reducing power as a result of frying. However, boiling and microwave cooking did not affect reducing power. Inhibition of peroxidation increased by boiling and frying, whereas, in contrast it was decreased by microwave cooking. The results of the present investigation showed that all the cooking methods affected the antioxidant properties of the vegetables; however, microwave treatment exhibited more deleterious effects when compared with those of other treatments. Thus an appropriate method might be sought for the processing of such vegetables to retain their antioxidant components at maximum level. [source] Changes in the fatty acid composition of vegetable oils in model doughs submitted to conventional or microwave heatingINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 4 2003Francesco Caponio Summary An experimental investigation ascertained the variation of the contents of saturated, unsaturated and polyenoic fatty acids, as well as of the trans -isomers of unsaturated fatty acids, in different vegetable oils (virgin olive oil, refined sunflower, refined peanut) submitted to either conventional or microwave heating. The results obtained showed that heat treatment causes a worsening of the nutritional quality of the fatty fraction. As a consequence, the contents of unsaturated and polyenoic fatty acids decreased, with greater variations in the oils heated by microwave than by a conventional oven, while the saturated fatty acid contents did not change substantially. The heat treatments also caused an increase in the trans -isomers of unsaturated fatty acids and this was more evident after microwave treatment. [source] Microwave-Assisted Solvothermal Synthesis of Copper Indium Diselenide PowdersJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2010Chung-Han Lee Copper indium diselenide (CuInSe2) powders were successfully synthesized using the microwave-assisted solvothermal process at 200°C within a short time. The reaction time for preparing single-phased CuInSe2 was significantly shortened with the developed microwave treatment. The microwave field enhanced the mobility of the reactants, thereby resulting in an accelerated reaction rate. CuSe was the major intermediate product during these reactions and the CuInSe2 phase was gradually formed as the reaction temperature and time were increased. The prepared powders exhibited plate-like and spherical shapes, and the fraction of plate was increased with increasing reaction time. The solvothermal route combined with the microwave heating system was found to significantly promote the formation of plate-like particles. [source] Synthesis of Hydrated Aluminum Sulfate from Kaolin by Microwave ExtractionJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2000Seong Soo Park The feasibility of extracting alumina from kaolin via a microwave extraction process was investigated by comparing reaction times, reaction temperatures, and acid concentrations under microwave treatment with the same factors under conventional thermal extraction. The maximum amount of alumina extracted from kaolin under conventional processing at 90°C for 240 min with 1M H2SO4 was 99.9%; the same amount of alumina was extracted under microwave processing at 90°C for 120 min with 1M H2SO4. [source] Electrophoretic patterns of microwaved and ,-irradiated beef liver proteinsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 10 2001S Farag Abstract The effects of ,-irradiation treatments (2.5, 5 and 10,kGy) and microwaves generated from an oven at low and defrost power settings for 0.5, 1 and 2,min on the total proteins and protein patterns of beef liver immediately after treatment and during frozen storage (,18,°C) for different periods were studied. Chemical analyses indicated that the protein content of beef liver was reduced after exposure to ,-radiation or microwaves and also during frozen storage. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) was used to illustrate the changes in protein bands of different molecular weights and their percentages before and after exposure to gamma and microwave radiation. The main effect of ,-radiation on the protein patterns of beef liver was the disappearance of some high-molecular-weight protein bands and the development of other bands characterised by moderate and low molecular weights. This finding indicates the degradation of beef liver proteins by ,-irradiation. In contrast, microwave treatment caused an increase in the levels of high-molecular-weight protein bands with a concomitant decrease in low-molecular-weight protein bands. This phenomenon demonstrates the polymerisation of low-molecular-weight proteins under the influence of microwaves. © 2001 Society of Chemical Industry [source] Rapid preparation of cyanobacterial DNA for real-time PCR analysisLETTERS IN APPLIED MICROBIOLOGY, Issue 1 2008J.P. Rasmussen Abstract Aims:, To develop a rapid preparation method for real-time PCR analysis of cyanobacteria from cultures or field samples. Methods and Results:, Field samples and cultures containing Anabaena circinalis, Cylindrospermopsis raciborskii or Microcystis aeruginosa were subjected to three cell disruption treatments: (i) heating during thermocycling, (ii) microwave irradiation in the presence of detergent and (iii) probe sonication. Treated samples were directly added to the PCR reaction and analysed on two different real-time devices. A statistically significant difference was evident in the cycle thresholds for each of the treatments in all but one culture and one environmental sample, sonication and microwave treatments performing better than direct addition. The microwave treatment was also compared to the Qiagen DNA Mini kit and performance was equivalent when treated samples were analysed as above. Conclusions:, Whilst microwave treatment was slightly less effective than probe sonication across all samples, it was more amenable to processing multiple samples and significantly better than heat treating the sample during thermocycling. Significance and Impact of the Study:, The microwave method described here is a simple, rapid and effective preparation method for cyanobacterial DNA that can be easily deployed in the field, making the most of the speed and flexibility offered by fixed and portable real-time PCR devices. [source] Preparation and Characterization of Microwave-treated Carboxymethyl Chitin and Carboxymethyl Chitosan Films for Potential Use in Wound Care ApplicationMACROMOLECULAR BIOSCIENCE, Issue 10 2005Panya Wongpanit Abstract Summary: CM-chitin and CM-chitosan films were successfully crosslinked by microwave treatment. Crosslinking of the microwave-treated CM-chitin films involved mainly the carboxylate and the secondary alcohol groups, while crosslinking of microwave-treated CM-chitosan films involved the carboxylate and the amino groups. In addition, the crystallinity of CM-chitin increased with increasing microwave treatment time, whereas an increase in the crystallinity of the microwave-treated CM-chitosan films was not observed. At a similar percentage of weight loss, the crosslinking of either CM-chitin or CM-chitosan films by microwave treatment required much less stringent condition when compared with the crosslinking by autoclave treatment. Based on both direct and indirect cytotoxicity assays, the cytotoxicity of the microwave-treated CM-chitin films was negative, while that of the microwave-treated CM-chitosan films was positive. Human fibroblasts adhered on the surface of microwave-treated CM-chitosan films much better than on the surface of microwave-treated CM-chitin films. Total amount of protein synthesis of living NHGF cells that were cultured on chitin, microwave-treated CM-chitin, chitosan, microwave-treated CM-chitosan films. [source] PCR detection of Fusarium oxysporum f.sp. gladioli race 1, causal agent of Gladiolus yellows disease, from infected cormsPLANT PATHOLOGY, Issue 1 2000De Haan Fusarium oxysporum f.sp. gladioli (FOG) race 1 infects both large- and small-flowered Gladiolus cultivars. Race 2 isolates infect only small-flowered cultivars but can be present as epiphytes on large-flowered plants. When 160 arbitrary 10-mer oligonucleotide primers were tested on FOG by PCR to find RAPD markers specific for race 1, the RAPD primer G12 amplified two discriminating DNA fragments, AB (609 bp) and EF (1196 bp), in race 1 isolates only. Both fragments were cloned and sequenced. Two pairs of race 1-specific primers for multiplex PCR were designed. Tests of 112 F. oxysporum isolates by PCR showed that, in almost all cases, race 1 isolates of vegetative compatibility group 0340 could be distinguished with these primers. Seven putative race 1 isolates did not react in multiplex PCR; hybridization studies with labelled AB and EF DNA fragments showed that these isolates belong to separate groups. A bioassay was developed to detect corms that were latently infected with FOG race 1. Gladiolus corms were homogenized and incubated for 5 days at 28°C in a semiselective medium to induce growth of Fusarium. Cultivated mycelium was isolated and subjected to the developed multiplex PCR after standard DNA isolation or disruption by microwave treatment. [source] IMPACT OF MICROWAVE BLANCHING ON THE FLAVOR OF ROASTED PEANUTSJOURNAL OF SENSORY STUDIES, Issue 4 2006ANDRIANA V. SCHIRACK ABSTRACT Microwave blanching of peanuts was proposed as an attractive alternative to traditional techniques of blanching, because of energy and time savings. However, the occurrence of a processing-related off-flavor has been reported. This study examined the effect of processing factors during microwave blanching on the MC and sensory characteristics of the peanuts. The peanuts reached a range of internal temperatures during microwave blanching treatments between 4 and 11 min. A total offnote attribute was introduced to the peanut lexicon and was used successfully to differentiate the effects of microwave treatments. The microwave-associated off-flavor was related (but not identical) to cardboardy/stale flavor, and was related inversely to the positive flavor attributes roasted peanutty, sweet aromatic and sweet taste. Peanuts reaching the highest internal temperatures and greatest moisture losses during blanching exhibited the most total offnote flavor; however, temperatures as high as 113C did not produce significantly increased total offnote intensity. [source] Rapid preparation of cyanobacterial DNA for real-time PCR analysisLETTERS IN APPLIED MICROBIOLOGY, Issue 1 2008J.P. Rasmussen Abstract Aims:, To develop a rapid preparation method for real-time PCR analysis of cyanobacteria from cultures or field samples. Methods and Results:, Field samples and cultures containing Anabaena circinalis, Cylindrospermopsis raciborskii or Microcystis aeruginosa were subjected to three cell disruption treatments: (i) heating during thermocycling, (ii) microwave irradiation in the presence of detergent and (iii) probe sonication. Treated samples were directly added to the PCR reaction and analysed on two different real-time devices. A statistically significant difference was evident in the cycle thresholds for each of the treatments in all but one culture and one environmental sample, sonication and microwave treatments performing better than direct addition. The microwave treatment was also compared to the Qiagen DNA Mini kit and performance was equivalent when treated samples were analysed as above. Conclusions:, Whilst microwave treatment was slightly less effective than probe sonication across all samples, it was more amenable to processing multiple samples and significantly better than heat treating the sample during thermocycling. Significance and Impact of the Study:, The microwave method described here is a simple, rapid and effective preparation method for cyanobacterial DNA that can be easily deployed in the field, making the most of the speed and flexibility offered by fixed and portable real-time PCR devices. [source] Characterization of oil sands naphthenic acids treated with ultraviolet and microwave radiation by negative ion electrospray Fourier transform ion cyclotron resonance mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 21 2010John V. Headley Naphthenic acids (NAs) are concentrated in oil sand process water (OSPW) as a result of caustic oil sands extraction processes. There is considerable interest in methods for treatment of NAs in OSPW. Earlier work has shown that the combination of ultraviolet (UV) and microwave treatments in the laboratory was effective in reducing the concentration of classical NAs. Here we apply Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to further characterize NAs treated with (a) UV (254,nm) in the presence of TiO2 catalyst; and/or (b) microwave irradiation (2.45,GHz). FT-ICR MS was used to characterize the NA fraction before and after treatment. Acidic oxygen-containing classes were most abundant in all samples whereas other heteroatomic classes were least abundant or not present in some samples. For example, the SO2 -containing species were absent in UV- or combined UV- and microwave-treated samples. The O2 class was dominant in all samples, indicative of NAs. However, samples treated with UV and microwave radiation have a lower relative abundance of other heteroatomic classes. We observed O2, S1O2, O3, S1O3, O4, O5, and O6 classes, whereas the species with relatively high On content, namely, the O3, O5, and O6 classes, were present only in UV- and microwave-treated samples. The relatively high On content is consistent with oxidation of the parent acids in treated samples. There may thus be potential implications for environmental forensics. For example, the monitoring of the ratio of SO2:O2 or tracking the relative abundances of O2, O3, O4, O5, and O6 classes may provide insights for distinguishing naturally derived oil sands components from those that are process-related in aquatic environments. Copyright © 2010 John Wiley & Sons, Ltd. [source] | ||||||||||||||||