• Korean Journal of Soil Science and Fertilizer
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• v.6 no.4
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• pp.221-226
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• 1973

In order to investigate the silica effect of insufficient wollastonite to the official standard (above than 15% of suluble silica (N/2 HCl) on rice plant as silica fertilizer, 9 kinds of wollastonites and slag were adopted to examine the amount of silica absorbed by rice straw during growing period, and soluble silica of wollastonites extracted by 7 buffer solutions were compared with silica content in rice straw. Crystalls of ingredient in wollastonite ores were identified by X-ray diffractometer. The results were that silica content of rice plant at growing stages were increased as same ratio of soluble silica. content in wollastonite. Wollastonite containing more than 10% of souble silica (N/2 HCl) could be applied as fertilizer because absorbed amount of silica by rice plant from them are higher than from slag which contained 30% of soluble silica. Wollastonite powder mixed with impure ores in which soluble silica could not be extracted had the same effect on silica absorption of straw as wollastonite powder which contained conformable amount of soluble silica. The soluble silica of wollastonite extracted by buffer solutions (2% citric acid, N. NaOAc, N. $NH_4OAc$, Petermann solution, 0.1M. EDTA, and Hot water) had high significant relation to silica content in rice straw, but soluble silica extracted N/2 hydrochloric acid solutilon, also, had deep relation to them in rice straw. The adequate solution to extract silica from wollastonites is N/2 hydrochloric acid solution because its extracted silia amount is much higher than other solution (about one hundred times) and can be determined by gravimetric analysis. X-ray diffraction pattern would identify qualitatively purity of wollastonite, and large amount of soluble silica was extracted from wollastonite which was appeared to be weathered.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.9
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• pp.1388-1398
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• 2015

Quality Function Deployment (QFD) is the most complete and comprehensive method for translating what customers need from a product. This study utilized QFD to develop sauces made from Gochujang and to determine how to fulfill international customers' requirements. A customer survey and expert opinion survey were conducted from May 13 to August 22, 2014 and targeted 220 consumers and 20 experts in the U.S. and China. Finally, a total of 208 (190 consumers and 18 experts) useable data were selected. The top three customer requirements for Gochujang sauces were identified as fresh flavor (4.40), making better flavor (3.99), and cooking availability (3.90). Thirty-three engineering characteristics were developed. The results from the calculation of relative importance of engineering characteristics identified that 'cooking availability', 'free sample and food testing', 'unique concept', and 'development of brand' were the highest. The relative importance of engineering characteristics, correlation, and technical difficulties are ranked, and this result could contribute to the development Korean sauces based on customer needs and engineering characteristics.

• Archives of design research
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• v.18 no.4 s.62
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• pp.105-118
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• 2005

Housing environment for human beings has been diversified and more convenient due to the development of high technology and civilization brought by industrialization in the 20th century. In the 21st century, how to overcome the ecological limit of biased development-centered advancement, that is, how to preserve and hand over a clean and healthy 'sustainable environment' to our next generations has been one of the most-talked about issues. Environmental symbiosis means a wider range of environmental harmony from micro-dimensional perspective to macro one. The three goals of a environmentally friendly house are to preserve global environment, to harmonize with the environment around, and to offer a healthy and comfortable living environment. From the point of view of environmental symbiosis, houses should be designed to save energy and natural resources for preservation of global environment, to collect such natural energy resources as solar heat and wind force, to recycle waste water, and recycle and reduce the amount of the waste matter. Now, the environmentally-friendly house became a new social mission that is difficult to not only challenge but also realize without conversion to a new paradigm, ecologism.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.6
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• pp.670-680
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• 2010

A low power single-chip CMOS receiver for 60 GHz mobile application are proposed in this paper. The single-chip receiver consists of a 4-stage current re-use LNA with under 4 dB NF, Cgs compensating resistive mixer with -9.4 dB conversion gain, Ka-band low phase noise VCO with -113 dBc/Hz phase noise at 1 MHz offset from 26.89 GHz, high-suppression frequency doubler with -0.45 dB conversion gain, and 2-stage current re-use drive amplifier. The size of the fabricated receiver using a standard 0.13 ${\mu}m$ CMOS technology is 2.67 mm$\times$0.75 mm including probing pads. An RF bandwidth is 6.2 GHz, from 55 to 61.2 GHz and an LO tuning range is 7.14 GHz, from 48.45 GHz to 55.59 GHz. The If bandwidth is 5.25 GHz(4.75~10 GHz) The conversion gain and input P1 dB are -9.5 dB and -12.5 dBm, respectively, at RF frequency of 59 GHz. The proposed single-chip receiver describes very good noise performances and linearity with very low DC power consumption of only 21.9 mW.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.4
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• pp.506-512
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• 2003

Peach wine was fermented at $25^{\circ}C$ for 2 weeks using Saccharomyces cerevisiae KCCM 12224, aged at 15$^{\circ}C$ for 14 weeks, and its physicochemical and microbiological changes were investigated. The viable bacterial cell numbers, 1.4$\times$10$^3$ CFU/mL at the beginning of fermentation, increased to 2.8$\times$10$^{6}$ CFU/mL after 2 weeks, but decreased to 7.0$\times$10$^3$ CFU/mL after 14 weeks. The viable yeast cell numbers were changed from 3.4$\times$10$^2$ CFU/mL to 2.4$\times$10$^{7}$ CFU/mL during fermentation, and decreased to 4.0$\times$10$^4$ CFU/mL after aging. Turbidity total sugar content, reducing sugar content, solid content and b value of peach wine decreased during fermentation but acidity, alcohol content, L and a value increased. Most physicochemical properties except alcohol content and reducing sugar content were not changed significantly during aging. When peach wine was filtered through 0.45 ${\mu}{\textrm}{m}$ nitrocellulose membrane followed by various ultrafiltration membranes with different molecular weight cut-off values, Biomax 100K membrane, with 79 liter/$m^2$/h (LMH) of initial flux, was suitable for ultrafiltration process of peach wine. These membrane filtration treatments resulted in complete removal of microorganisms and decrease in turbidity and alcohol content without changes in other chemical properties. The physicochemical properties of peach wine were not changed and any microorganisms were not found during the storage at 3$0^{\circ}C$ for 12 Weeks.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.11
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• pp.1562-1568
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• 2011

We studied the amounts of trans fatty acids and saturated fatty acids in child-favored foods. Confectioneries, breads, donuts and hamburgers were included in this study. The total fatty acid content and the amount of each type of fatty acid were determined by gas chromatography with a flame-ionized detector. Confectioneries were shown to have the highest content of crude fat. The mean content was 24.2${\pm}$6.9 (range: 4.6~41.1) g/100 g food. The mean content of crude fat in donuts, bread and hamburgers was 23.9${\pm}$5.8 (range: 14.1~39.5) g/100 g food, 15.7${\pm}$7.9 (range: 1.4~30.0) g/100 g food, and 9.5${\pm}$3.4 (range: 4.5~18.5) g/100 g food, respectively. Bread had the most trans fatty acids at 1.3 g/100 g food. This result inferred that manufacturers have tried to reduce the trans fat content. The mean content of saturated fatty acids in confectioneries, donuts, bread, and hamburgers was 11.6${\pm}$4.8 (range: 2.0~22.7) g/100 g food, 11.2${\pm}$4.0 (range: 4.8~23.2) g/100 g food, 6.9${\pm}$4.1 (range: 0.6~15.4) g/100 g food, 3.0${\pm}$1.0 (range: 1.0~5.8) g/100 g food, respectively. This content depended on crude fat. The composition of fatty acids varied according to the oil and fat used in the manufacturing process of each food, and the natural content. Foods that were fried in vegetable oil tended to be especially low in saturated fat.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.12
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• pp.1640-1646
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• 2008

In the current food sanitation regulation, food additives are under controlled by the Food Code. The naturally derived preservatives such as benzoic acid and propionic acid can be naturally carried over or produced as metabolites during manufacturing process such as fermentation. To monitor naturally formed benzoic acid and propionic acid levels, a total of 145 samples were classified into berries (prune, cranberry), functional foods (propolis liquid, ginseng product), vinegars (vinegar-based drink, vinegar beverage, vinegar), and salted and pickled products (olive, pickled cucumber, salted/pickled product) and analyzed by HPLC-PDA and GC-FID. From the results, benzoic acid and propionic acid were each detected and identified in 144 samples and 64 samples respectively. The amount of benzoic acid ranged from $4.1{\sim}478.4\;ppm$ in cranberry, from $49.7{\sim}491$ in propolis liquid, and from $2.5{\sim}10.2\;ppm$ in ginseng, and other tested samples contained very small quantity. Also, the amount of propionic acid ranged from $179.8{\sim}951.9\;ppm$ (av. 553.6 ppm) in vinegar (persimmon vinegar 100%), which was the highest level among fermented foods, from $13.7{\sim}247.0$ ppm in propolis liquid, from $2.0{\sim}180.7\;ppm$ in vinegar-based drink, and from $1.6{\sim}76.6\;ppm$ in olive. Vinegar beverage and pickled cucumber each showed 24 and 18 ppm of propionic acid; in contrast, propionic acid was not detected in prune, cranberry, ginseng, and picked/salted products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.12
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• pp.1769-1775
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• 2016

Aerial parts (leaves and stems) of radish are usually discarded due to the distinct undesirable flavors associated with inappropriate preparations, despite their many health benefits. In this study, we examined the role of extrusion process in the removal of off-flavors and elevation of antioxidant activity in radish (Raphanus sativus L.) leaves and stems. To optimize the extrusion conditions, we changed the barrel temperature (110, 120, and $130^{\circ}C$), screw speed (150, 200, 250, and 300 rpm), and moisture content (20, 25, and 30%). The polyphenol and flavonoid contents significantly increased in extruded radish leaves and stems (ER) under optimum extrusion conditions ($130^{\circ}C$, 250 rpm, and 20%). Under extrusion conditions, we compared off-flavors (as amount of sulfur-containing compound) levels between ER and non-extruded radish leaves and stems (NER) by an electronic nose. A total of six peaks (sulfur-containing compound) were similarly detected in both ER and NER, whereas the ER showed reduced off-flavors. Levels of glucosinolate (${\mu}g/g$), which can be hydrolyzed into off-flavors during mastication or processing, were significantly decreased in the ER. From these results, extrusion processing can be an effective method to increase anti-oxidant activity and removal of off-flavors in radish leaves and stems.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.4
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• pp.79-93
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• 1984

The dissolved air flotation(DAF) has been shown to be efficient process for the removal of algae ftom water. The efficiency of DAF can be affected by the volume ratio of pressurized liquid to sample, the pressure pressurized liquid, the contact time, the appropriate coagulant and its amount, the water temperature, the turbulence of reactor, the bubble size and rising velocity etc. The purpose of this paper is to compare the practical bubble rising velocity with the theoretical one, to investigate the adhesion phenomenon of bubbles and floc, and the influence of bubble size and velocity upon the process. The results through theoretical review and experimental investigation are as follows: Ives' equation is more suitable than Stokes' equation in computation of the bubble rising velocity. The collection of bubble and algae floc is convective collection type and resulted from absorption than adhesion or collision. The treatment efficiency is excellent when the bubble sizes are smaller than $l00{\mu}m$, and the turbulence of reactor is small. In the optimum condition of continuous type DAF the volume ratio of pressurized liquid to sample is 15%, the contact time in reactor is 15 minutes, the pressure of pressurized liquid is $4kg/cm^2$ and the distance from jet needle to inlet is 30cm.

• Journal of Life Science
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• v.24 no.10
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• pp.1046-1054
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• 2014

Beta-1,3-glucanase is widely used in various biotechnological and industrial processes, with over-production required to enable versatile utilization. We examined the overexpression of ${\beta}$-1,3-glucanase (EXGA) from Aspergillus oryzae using ${\delta}$-sequence-mediated integration. We constructed $pRS{\delta}$-exgA and $pRS{\delta}K$-exgA plasmids for integration of the EXGA gene into various chromosomes of Saccharomyces cerevisiae. These plasmids contain the ADH1 promoter for constitutive expression, a signal sequence (exoinulinase signal sequence [INU1 s.s]) for secretory production, and a ${\delta}$-sequence for integration of ${\beta}$-1,3-glucanase. The $pRS{\delta}$-exgA plasmid was transformed into the S. cerevisiae $BY4742{\Delta}exg1$ strain, and ${\beta}$-1.3-glucanase was stably overexpressed and secreted. Another plasmid, $pRS{\delta}K$-exgA, was introduced into the S. cerevisiae $BY4742{\Delta}exg1$ (YKY082) strain, and overexpression of ${\beta}$-1,3-glucanase was examined by inducible integration under geneticin selection. The activity of ${\beta}$-1,3-glucanase increased in accordance with a rise in the geneticin concentration, with 0.8 mg/ml of geneticin suitable for overexpression of ${\beta}$-1,3-glucanase. Subsequently, $pRS{\delta}K$-exgA was repeatedly transformed for sequential ${\delta}$-integration. The activity of ${\beta}$-1,3-glucanase reached about 0.063 unit/ml/$OD_{600}$, 0.095 unit/ml/$OD_{600}$, 0.131 unit/ml/$OD_{600}$ and 0.165 unit/ml/$OD_{600}$ by the first, second, third, and fourth round of integration, respectively. According to the increase in the activity of ${\beta}$-1,3-glucanase by sequential ${\delta}$-integration, the copy number (integration rate) of the EXGA gene also increased in various chromosomes. These results suggest that recombinant ${\beta}$-1,3-glucanase activity can be sequentially increased by repeated ${\delta}$-sequence integration.