• Applied Chemistry for Engineering
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• v.31 no.2
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• pp.208-214
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• 2020

In this study, the characteristics and mechanism of microwave-assisted drying were investigated to improve the efficiency of the storage and extraction of biomass through the removal of moisture from plant cell Taxus chinensis. The efficiency of microwave-assisted drying increased with increasing microwave power. When the experimental data were fitted to typical drying kinetic models, the page and modified Page models were the most appropriate. The microwave-assisted drying was determined to be a spontaneous endothermic process, and randomness increased during the drying process. The effective diffusion coefficient (3.445 × 10^-9~7.163 × 10^-7 ㎡/s) and mass transfer coefficient (3.1529 × 10^-5~1.2895 × 10^-2 m/s) increased with increasing microwave power. The small Biot number (0.3890~0.7198) indicated that the mass transfer process was externally controlled.

• Journal of the Korean Ceramic Society
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• v.41 no.11
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• pp.804-811
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• 2004

We have studied microwave extraction process of boric acid from one of calcium borate ores, colemanite. Calcium and boron have separated by addition of sulfuric acid, and calcium has been separated out as calcium sulfate. It was possible to extract boron with the smaller amount of sulfuric acid and with short heating time in microwave heating compared to conventional heating process. The products of boric acid was the same purity and thermal characteristic, but smaller in particle size.

• Korean Journal of Microbiology
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• v.38 no.2
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• pp.103-106
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• 2002

Direct PCR from intact fungal cells is not readily suitable to all fungi mainly because of difficulties in rupturing the cell walls. Microwave irradiation has been proven to be useful in fungal DNA extraction protocol. Here we describe a fast template preparation method for PCR amplification from Aspefillus nidulans conidiospores using microwave irradiation. We optimized the duration far microwave irradiation, and the amount of template DNA for PCR. Amplification from samples prepared in this manner was so efficient that we could get PCR products with size enough to identify transformants. We believe that this is a time-saving procedure for screening true transformants of A. nidulans.

• ETRI Journal
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• v.38 no.1
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• pp.70-80
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• 2016

This paper addresses the problem of robust waveform design for distributed multiple-radar systems (DMRSs) based on low probability of intercept (LPI), where signal-to-interference-plus-noise ratio (SINR) and mutual information (MI) are utilized as the metrics for target detection and information extraction, respectively. Recognizing that a precise characterization of a target spectrum is impossible to capture in practice, we consider that a target spectrum lies in an uncertainty class bounded by known upper and lower bounds. Based on this model, robust waveform design approaches for the DMRS are developed based on LPI-SINR and LPI-MI criteria, where the total transmitting energy is minimized for a given system performance. Numerical results show the effectiveness of the proposed approaches.

• Journal of Energy Engineering
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• v.21 no.4
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• pp.325-338
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• 2012

Currently, there are the technologically urgent needs of fabricating the hyper coal (HC) based on the approach to extracting mainly effective organics from low rank coals (LRCs), because some industrial countries pursue global sustainability dealing with hot issues such as local energy supply security as well as global warming. In this study, as of the fabrication of clean HCs via LRCs upgrading, we comprehensively review the R&D status of two solvent extraction technologies, namely, Ohm heating (OH) and microwave irradiation (MI) extraction processes on the basis of the performance indicator such as a HC extraction yield.

• KSBB Journal
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• v.27 no.3
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• pp.177-185
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• 2012

Inonotus obliquus mushroom, which is a fungus belonging to Hymenochaetaceae family, is known to grow on birth trees in colder northern climates and to be a fungal parasite that draws nutrients out of living trees rather than from the ground. For the separation of protein-bound polysaccharide (PBP) from the culture broth and mycelium of Inonotus obliquus, three well known extraction methods namely hot water, ultrasound and microwave were used. The best extraction conditions to separate the PBP (64.94 mg/g) from mycelium by microwave were found to be for 1 hour and $150^{\circ}C$. The possibility for concentration of extracted PBP solution by using membrane was also studied. The extracted PBP solution was concentrated effectively by using an ultrafiltration membrane and the molecular weight cut off (MWCO) is 30 KDa. It was observed that a concentration by the ultrafiltration membrane is essential not only for the development of clean separation technology but also for enhanced production of PBP. As a result, we have shown that PBP in the final concentrated solution showed approximately 10 times higher than that in the crude solution by application of the developed separation systems. The separation yield of PBP was about 89.79% by gel filtration of purification steps and the purified product was confirmed to be PBP by using FT-IR.

• Journal of Environmental Science International
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• v.19 no.3
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• pp.379-387
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• 2010

Sediments of Little Scioto (LS) River in Ohio was contaminated by poor disposal of creosote from Baker Wood Creosoting Facility. Among the primary compounds of creosote, Polycyclic Aromatic Hydrocarbons (PAHs) are the most common ingredient PAHs are known for toxic, carcinogenic and mutagenic compounds. There are many difficulties to remove the PAHs in nature environment because their characteristics are having a less water-solubility, volatile and low mobility properties as increasing the molecular weight. The generation of hydroxyl radicals (${\cdot}OH$) and hydrogen peroxide ($H_2O_2$) forms as well as high temperature (5000 K) and pressure (1000 atm) by a physico-chemical effects of ultrasound during a cavitation collapse can promote the degradation and desorption of PAHs in sediment And it can also produces shock wave and microjets which are able to change the size and surface of particle in solid-liquid system as one of physical effects. Therefore, we explored to understand the role of particle size, the effect of elimination for PAHs concentration by ultrasound and optimize the conditions for ultrasonic treatment. The condition of various size of particles (> $150{\mu}m$, < $150{\mu}m$) and solid-liquid ratio (12.5g/L, 25g/L) for the treatment was considered and ultrasonic power (430 W/L) with liquid - hexane extraction and microwave extraction method were applied after ultrasound treatment.

• Journal of Microbiology and Biotechnology
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• v.17 no.5
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• pp.847-852
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• 2007

This study investigated an efficient method for the extraction of astaxanthin from the red yeast Xanthophyllomyces dendrorhous. The extraction process comprised three steps: 1) cultivating the yeast; 2) treating the yeast culture suspension with microwaves to destroy the cell walls and microbodies; and 3) drying the yeast and extracting the astaxanthin pigment using ethanol, methanol, acetone, or a mixture of the three as the extraction solvent. Ultimately, various treatment tests were performed to determine the conditions for optimal pigment extraction, and the total carotenoid and astaxanthin contents were quantified. A frequency of 2,450 MHz, an output of 500 watts, and irradiation time of 60 s were the most optimum conditions for yeast cell wall destruction. Furthermore, optimal pigment extraction occurred when using a cell density of 10g/l at $30^{\circ}C$ over 24 h, with a 10% volume of ethanol.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2003.04a
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• pp.118-121
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• 2003

• Korean Journal of Food Science and Technology
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• v.28 no.5
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• pp.814-821
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• 1996

An attempt was made to determine the effects of drying methods including shady air drying, presteamed and shady air drying, microwave drying, and freeze drying on the volatile flavor components of Capsella bursapastoris. Essential oils from the samples were isolated by Simultaneous steam distillation-extraction (SDE) method using diethyl ether as solvent. Concentrated samples were analyzed by gas chromatography (GC) and combined gas chromatography-mass spectrometry (GC-MS). Respective 30, 18, 29, and 26 volatile flavor components were identified in shady air dried samples, presteamed and shady air dried samples, microwave dried samples, and freeze dried samples. The kinds and amounts of volatile flavor components evidently depended upon the drying methods. Trimethyl sulfide was regarded as the most abundant component in shady air dried samples, dimethyl trisulfide in presteamed and shady air dried samples, and phytol in microwave or freeze dried samples.