• Journal of Plant Biology
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• v.24 no.1
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• pp.31-45
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• 1981

The purpose of this study aimed to study effects of fire on vegetation and soil properties after the first growing season in Mt. Chiak. 1. With the basis of importance value of species in each stand, status of species was assessed for three categories; Increaser species, Decreaser species, and Neutral species. 2. Biomass was 2.2 times higher on burned area than unburned. This indicates that biomass was remarkably increased after fire. 3. To evaluate similarity, coefficients of similarity among communities were obtained, and correlation coefficients were also estimated. These indices showed that burned and unburned community were markedly different.. $B_1$-stand and $B_1$-stand appeared most similar to each other among stands. 4. Species diversity was greater in burned than unburned stands. 5. Soil pH value and organic matter content in burned area were significantly higher than those in unburned area. However, soil water content was lower in burned area. There was no effect of burning on soil pH value and water content at 15~20 cm depth of soil. 6. All chemical compositions except sodium were much higher in soil surface. The decreases in sodium levels at surface were probably resulted from the rapid leaching due to the increased solubility and decreased capacity for adsorption of sodium in comparison with potassium or calcium. Among chemical compositions of soil amount of nitrogen showed least difference between the burneb and unburned surfaces soil.

• Polymer(Korea)
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• v.36 no.2
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• pp.229-234
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• 2012

This paper studied the effects of the content and the orientation of the disk shape fillers on the modulus of PP composites. The experimental results were compared with the theoretical calculations which included the three dimensional ellipsoids and analyzed by two aspect ratios, ${\rho}_{\alpha}=a_1/a_3$and ${\rho}_{\beta}=a_1/a_2$proposed by Lee and his researchers. Mica and talc were used as disk shape fillers in the composites. The shapes of mica and talc were observed by SEM and aspect ratios were statistically calculated. For the case of mica, the average aspect ratios were ${\rho}_{\alpha}=13.5$ and ${\rho}_{\beta}=1.8$, and for the case of talc, they were ${\rho}_{\alpha}=3.8$ and ${\rho}_{\beta}=1.4$. Also, the effects of two aspect ratios and the content of filler on the mechanical properties were studied: For 30 wt% of mica, $E_{11}$ increased up to about 2.7 times, and for the other case of talc, $E_{11}$ increased up to about 2.3 times, respectively.

• Journal of Adhesion and Interface
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• v.18 no.1
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• pp.13-24
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• 2017

In this study, nanoparticles which encapsulated hydrophobic antimicrobial compounds with 50wt% of payload and 70%of solid content were prepared. These nanoparticles could be dispersed at water as well as various medium. Water dispersible organic-inorganic (O-I) hybrid nanoparticles were first prepared using alkoxysilane-functionalized amphiphilic polymer precursors through a conventional sol-gel process. Hydrophobic antimicrobial compound, Eugenol encapsulated nanoparticles were prepared using these O-I hybrid nanoparticles through a new nanoprecipitation process. The effect of various preparation on the size of nanoparticles, amount of payload, antimicrobial activity, and release rate of encapsulated compounds was investigated. All eugenol-encapsulated O-I nanoparticles regardless of preparation condition showed the same minimal inhibitory concentration (MIC) (50mg/ml) and 99% of antimicrobial activity for every strain. Their antimicrobial activity could maintain longer than two weeks. Especially, eugenol-encapsulated O-I nanoparticles prepared using tetraethoxysilane (TEOS) exhibited the highest payload (50wt%) and the lowest release rate which was owing to higher inorganic content in the O-I nanoparticles. And these O-I nanoparticles dispersed in hexanediol (HD) showed the highest antimicrobial activity and solid content (70wt%) because HD acted as a solvent as well as a antimicrobial agent.

• Food Science and Preservation
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• v.23 no.7
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• pp.1042-1049
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• 2016

This study was conducted to investigate and compare the characteristics of acetic acid fermentation in detoxified Rhus verniciflua vinegar (DRV) produced by different yeast strains. The DRVs were prepared by static acetic acid fermentation using six different yeast strains (Saccharomyces cerevisiae Fermivin, Pichia kudriavzerii N77-4, Hanseniaspora pountiae HP1-2, Candida tropicalis Y447, Wickerhamomyces anomalus N43-8, and Pichia kluyveri Frootzen). Alcohol content of the S. cerevisiae Fermivin fermented DRV was highest 16.07%. Among the yeast strain DRVs, there were significant differences in alcohol content, but all alcohol levels were 11%. Moreover, there were differences in pH and titratable acidity of the DRVs. The organic acid content of the DRVs ranged from 35.88 to 55.49 mg/mL and there were significant differences among the yeast strain DRVs. Essential free amino acids, particularly glutamic acid, alanine, leucine and valine, were detected in each of the 6 DRVs. Electronic nose analysis revealed that three different volatile chemical patterns were present in the 6 DRVs. The results indicate that yeast strains with different characteristics can produce vinegars with different characteristics.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.171-177
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• 2005

Nutritional compositions and antioxidative activity of Kabocha squash (Cucurvita maxima Duch) as health food were compared with those of pumpkin (Cucurvita moschata Duch). Kabocha squash had higher soluble solids and twofold harder flesh than pumpkin. Crude protein, crude lipid and total amino acid contents of Kabocha squash were higher than those of pumpkin. Major free sugar in Kabocha squash was sucrose, and its content were 2.1 times higher than that of pumpkin. Major organic acids of Kabocha squash and pumpkin were succinic and malic acid, respectively. Kabocha squash had higher amounts of vitamins $A,\;B_1,\;B_2,\;C$ and C than pumpkin, while both showed similar mineral contents except for iron. Contents of Total pectin and hydrochloric acid soluble pectin of Kabocha squash were 17.00 and 7.37 g/100 g AIS, respectively. In pumpkin, total pectin content was 25.14 g/100 g AIS, and water soluble pectin content was higher than those of other pectin fractions. Contents of carotenoid in Kabocha squash and pumpkin were 285.91 and 24,62 mg% d.b., respectively. Kabocha squash had higher electron-donating radical-scavenging activity, SOD-like activity and nitrite-scavenging effect than pumpkin.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.1
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• pp.71-80
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• 2004

This study was conducted to investigate the effects of the type and application season of animal manure (AM) on herbage productivity, efficiency of nitrogen utilization in mixed grassland. Main plots were the types of AM, such as cattle feedrot manure (CFM), swine manure fermented with sawdust (SMFWS) and cattle slurry (CS). Subplots were the seasons of AM application. such as application in autumn or in spring as single dressing. and application in autumn and spring as a 50:50 split dressing. The results obtained where summarized as follows ; 1. Herbage productivity and nutritive value were hardly influenced by type and application season of AM. 2. Nitrogen efficiency of CFM and CS was lower than that of SMFWS. 3. Organic matter (OM) content in the soil was not significantly different by the type and application season of AM. OM content among AM treatments was the highest with CFM and the lowest with CS. 4. Nitrogen content of the soil was hardly influenced by the type and application season of AM and not affected by the interaction between the type and application season of AM.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.4
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• pp.423-430
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• 2011

This study was carried out to examine the nutritive values and quality of agricultural bag (AG-BAG) silage manufactured with corn grown in reclaimed paddy field of Sukmoon at Dangjin Province in Korea. The cultivars of silage corn used in this experiment 1 were both Kwangpyungok and P32B33. The fertilizer were applied with the amounts of customary applications (200 kg N/ha, 150 kg $P_2O_5$/ha and 150 kg $K_2O$/ha). The content of moisture in corn AG-BAG silage ranged from 68 to 79%. The pH in corn AG-BAG silage stages ranged from 3.49 to 3.65 and was not influenced by the harvest time. The contents of crude protein (CP) in corn AG-BAG silage decreased with delayed harvest time. However, the contents of ADF (acid detergent fiber) and NDF (neutral detergent fiber) increased. The content of lactic acid increased with delayed harvest time, but the content of acetic acid decreased. Therefore, we suggest that the system of AG-BAG silage can improve the quality of corn silage and be one of the economical and effective methods to manufacture corn silage.

• Korean Journal of Food Science and Technology
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• v.19 no.4
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• pp.338-345
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• 1987

The Physicochemical properties of six varieties of domestic orange and orange juices which were grown and produced in Korea, were analyzed their qualities, including taste evaluation based on the amount and the ratio of sugar and acid The physicochemical properties of mandarin were as follows soluble solid $10{\sim}11^{\circ}$ Bx, total acidity $0.76{\sim}1.20%$ ratio of sugar and acid $7.9{\sim}13.8$. Sugars of orange are mainly composed of sucrose, glucose, fructose. The sucrose content of mandarin was a little higher than that of sweet orange. The organic acids in orange were mainly citrate and malate. The content of these two acid in oranges were 0.8-1.4%. Mandarin type oranges tastes more sour than sweet orange. Hesperdin existed 30.8-67.5mg% in oranges. Naringin, one of the bitter components. was not detected in both varieties. The optimum sweetness and acid content were determined based on the results of sensory evaluation.

• Korean Journal of Food Science and Technology
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• v.52 no.2
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• pp.113-118
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• 2020

We investigated the quality characteristics and antioxidant capacities of Korean commercial yogurt. Twenty commercial yogurt samples exhibited a pH of 4.05-4.51, titratable acidity of 0.80-1.45%, viable counts of 6.65-9.39 log CFU/g, and total phenolic content of 0.71-2.92 mg gallic acid equivalent/g dry weight (dw). Lactic acid was the major organic acid detected by HPLC with UV detection, and its content was 5.4 times and 46.5 times higher than that of malic acid and citric acid, respectively. The tested commercial yogurt samples exhibited antioxidant potential (1.62-8.95 mM trolox equivalent/g, dw) measured based on scavenging activities of DPPH and ABTS radicals. The average antioxidant potentials of commercial set yogurt containing fruit syrup were significantly (p<0.05) higher than that of cream and plain yogurt. A positive linear correlation was observed between the total phenolic content and the antioxidant capacities, suggesting that phenolic components are likely to contribute significantly to the antioxidant potential of commercial yogurt.

• The Korean Journal of Food And Nutrition
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• v.18 no.4
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• pp.302-308
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• 2005

To examine the difference in each ingredient between the yeast strain and two raspberry kinds (Rubus crataegifolius Bunge(RCB), Rubus coreanus Miquel(RCM)) in the making of raspberry wine, five active dry yeasts were selected. Regarding the RCM ethanol content, the raspberry wine fermented by Lalvin Wl5 was the highest, while those fermented by Prise de Mousse were the lowest. The pH of the RCM was $3.58\~3.63$, and Montrachet was the highest one of total acidity. In the case of nonflavonoid phenols, the RCM fermented by Montrachet was the highest one, and in the case of flavonoid phenol and total phenol, the RCM fermented by Epernay II was the highest. The content of organic acid in RCM were highest in the following order: citric acid > oxalic acid > malic acid, and tartaric acid was not detected at all. The average content of malic acid in RCM after malolactic fermentation was reduced by almost $65.5\%$, and the RCM fermented by Prise de Mousse, after malolactic fermentation, was $73.3\%$. This latter was the highest, while the RCM fermented by Epernay II was the lowest, at $59.1\%$.