• Korean Journal of Food Science and Technology
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• v.53 no.5
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• pp.593-600
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• 2021

In this study, the vacuum distillation process for producing non-alcoholic red wine was optimized via response surface methodology. As a result of optimizing the responses (alcohol content, yield) for independent variables (operating time, boiling point, and temperature difference), 1% alcohol content and 81.15% yield were obtained at an operating time of 24.5 min, boiling point of 65℃, and temperature difference of 8℃. To investigate the physicochemical and sensory properties, non-alcoholic wines with different boiling points (bp 25℃, bp 45℃, and bp 65℃) and a blended wine (4.2% of control wine added) were prepared. As the boiling point increased, the alcohol content decreased, and CI (color intensity) and Hue increased. Blended wine exhibited the highest value and bp 65℃ showed the lowest value in terms of sensory properties. In conclusion, distillation at a low boiling point and blending control wine could be used to prepare non-alcoholic wine with a high preference.

• Korean Journal of Ecology and Environment
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• v.55 no.2
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• pp.156-166
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• 2022

Understanding the characteristics of reservoir water quality is fundamental in reservoir ecosystem management. The water quality of reservoirs is affected by various factors including hydro-morphology of reservoirs, land use/cover, and human activities in their catchments. In this study, we classified 83 major reservoirs in South Korea based on nine physicochemical factors (pH, dissolved oxygen, chemical oxygen demand, total suspended solid, total nitrogen, total phosphorus, total organic carbon, electric conductivity, and chlorophyll-a) measured for five years (2015~2019). Study reservoirs were classified into five main clusters through hierarchical cluster analysis. Each cluster reflected differences in the water quality of reservoirs as well as hydromorphological variables such as elevation, catchment area, full water level, and full storage. In particular, water quality condition was low at a low elevation with large reservoirs representing cluster I. In the comparison of eutrophication status in major reservoirs in South Korea using the Korean trophic state index, in some reservoirs including cluster IV composed of lagoons, the eutrophication was improved compared to 2004~2008. However, eutrophication status has been more impaired in most agricultural reservoirs in clusters I, III, and V than past. Therefore, more attention is needed to improve the water quality of these reservoirs.

• Applied Chemistry for Engineering
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• v.19 no.1
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• pp.122-128
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• 2008

We evaluated the relationship between the multiplication of heterotrophic microorganisms and physicochemical factors in the final discharged sewage water from J municipal waste water treatment plants. Dissolved organic carbon (DOC) was the most crucial factor influencing multiplication of heterotrophic plate counts (HPC) among the water quality variables selected. Degrading bacteria, such as proteolytic bacteria, lipholytic bacteria, starch degrading bacteria, cellulolytic bacteria, and pectinolytic bacteria, were monitored to understand the condition of nutrients in finished sewage effluent. The percentages of lipid and protein combined occupied 81% in finished sewage water. The multiplication of HPC showed the highest value in August. The formation of trihalomethane (THM) was low in the finished discharge water during chlorine disinfection, which was $71{\mu}/L$ (which was less than $100{\mu}/L$- the standard of drinking water quality) with 10 mg/L of chlorine during 15 min.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.6
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• pp.394-398
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• 2014

We fabricated the electrolyte-dielectric-metal (EDM) sensor on the base of AAO (anodic aluminum oxide) template with variation of the anodizing temperature. When a surface is immersed or created in an aqueous solution, a discontinuity is formed at the interface where such physicochemical variables as electrical potential and electrolyte concentration change significantly from the aqueous phase to another phase. Because of the different chemical potentials between the two phases, charge separation often occurs at the interfacial region [1]. This interfacial region, togeter with the charged surface, is usually known as the electrical double layer (EDL) [2]. The structural and electrochemical properties of AAO sensor were investigated for applications in capacitive pH sensors. To change the thickness of the AAO template, the anodizing temperature was varied from $5^{\circ}C$ to $20^{\circ}C$, the thickness of the AAO template invreased from 300 nm to 477 nm. The pH sensitivity of sensors with the anodizing temperature of $20^{\circ}C$ showed the highest value of 56.4 mV/pH in the pH range of 3 to 11. The EDM sensor with the anodizing temperature of $20^{\circ}C$ exhibited the best long-term stability of 0.037 mV/h.

• Journal of Korean Orthopaedic Sports Medicine
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• v.4 no.1
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• pp.6-11
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• 2005

Injury of articular cartilage can be classified into acute injury and chronic degenerative osteoarthritis Acute mechanical trauma on articular cartilage causes injuries that are divided into three distinct types based on the depth of injury: microdamage, chondral fracture, osteochondral fracture and each type has different potential of healing response and long-term prognosis. Articular cartilage undergoes degradation in response to a number of stimuli and eventually degenerative osteoarthritic changes will progress. The extent of initial injury to the articular cartilage is the most important factor affecting the long-term outcome of the healing response and other variables such as the size of lesion, site, age, activity level, obesity, limb alignment are also important factors. In this review, the pathophysiology that occurs within articular cartilage after different injuries and the effect of nonsurgical treatment mainly in physicochemical aspect and biological aspect will be discussed.

• Korean Journal of Ecology and Environment
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• v.38 no.2 s.112
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• pp.261-270
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• 2005

Biological control agents (BCA; algicidal bacterium Xantobacter autotrophycus) plus casitone media, strongly changed physicochemical variables, standing crops of phytoplankton and microcystin-LR phytoplankton in 100-L mesocosm constructed in a small hexagonal pond (3.5 m ${\times}$ 5 m). No M. aeruginosa showed by 8 days, and 60% of total standing crops of phytoplanktons were decreased by the BCA treatment. BCA treatment also induced a strong decline of cellular extracted microcystin-LR (MCLR) and a remarkable increase of dissolved MCLR with the decrement in standing crops of cyanobacteria. In addition, BCA strongly increased all nutrients, but new outbreak of phytoplanktons hardly showed in the experimental mesocosm. The field application of BCA to controling the cyanobacterial bloom in large lakes and reservoirs is not relevant due to high concentration of nutrients and toxins. Thus, a further study is needed to diminish the adverse effects after BCA treatment for water quality preservation.

• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.561-566
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• 1994

The kinds of kochujang were discriminated by using their organic acid compositions, GC peak areas of volatile concentrates and flavor intensity determined by sensory evaluation. Tested kochujang were 51 kinds of traditional kochujang and 10 kinds of industry-produced kochujang in the market. The traditional kochujang included 20 kinds of Sunchang kochujang prepared with glutinous rice, 11 kinds of Boeun kochujang prepared with barley and 20 kinds of Sachun kochujang prepared with wheat. Boeun kochujang was distinguished from other kinds of traditional and industry-produced kochujang by using canonical discriminant analysis for the compositions of organic acids. Among organic acids, lactic acid was the most contributing variable for the discrimination of various kochujang. Traditional and industry-produced kochujang could be classified into 4 groups by using discriminant analysis for GC peak areas. The peak number 2, 4, 8 and 11 were found to be highly contributing variables for the discrimination of kochujang by using stepwise discriminant analysis. Industry-produced kochujang was discriminated from traditional kochujang by using canonical discriminant analysis for the intensity of 8 kinds of flavor property. The taste 'umami' was found to be the most contributing variable for the discrimination of kochujang.

• Restorative Dentistry and Endodontics
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• v.41 no.4
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• pp.246-254
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• 2016

Objectives: The aim of this investigation was to give insights into the impact of carbohydrate-electrolyte drinks on the likely capacity of enamel surface dissolution and the influence of human saliva exposure as a biological protective factor. Materials and Methods: The pH, titratable acidity (TA) to pH 7.0, and buffer capacity (${\beta}$) of common beverages ingested by patients under physical activity were analyzed. Then, we randomly distributed 50 specimens of human enamel into 5 groups. Processed and natural coconut water served as controls for testing three carbohydrate-electrolyte drinks. In all specimens, we measured surface microhardness (Knoop hardness numbers) and enamel loss (profilometry, ${\mu}m$) for baseline and after simulated intake cycling exposure model. We also prepared areas of specimens to be exposed to human saliva overnight prior to the simulated intake cycling exposure. The cycles were performed by alternated immersions in beverages and artificial saliva. ANOVA two-way and Tukey HDS tests were used. Results: The range of pH, TA, and ${\beta}$ were 2.85 - 4.81, 8.33 - 46.66 mM/L and 3.48 - $10.25mM/L{\times}pH$, respectively. The highest capacity of enamel surface dissolution was found for commercially available sports drinks for all variables. Single time human saliva exposure failed to significantly promote protective effect for the acidic attack of beverages. Conclusions: In this study, carbohydrate-electrolyte drinks usually consumed during endurance training may have a greater capacity of dissolution of enamel surface depending on their physicochemical proprieties associated with pH and titratable acidity.

• Journal of Ecology and Environment
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• v.34 no.2
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• pp.223-235
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• 2011

Juncus effusus is mostly found in freshwater wetlands and is widely used for landscaping and creating artificial wetlands due to its high ecological value. J. effusus tends to dominate during the early stage (3-10 years) of the second succession in abandoned paddy fields. This study focused on the environmental characteristics of J. effusus to create habitat for an endangered species, Nannopya pygmaea, which lives in wetlands dominated by J. effusus. Considering the distribution of J. effusus and N. pygmaea, 63 quadrats at eight wetlands were investigated between May and June 2006 during the critically dry period. Fifty-three species from 28 families co-occurred with J. effusus, and Persicaria thunbergii was the most abundant (63.5%). The optimal ranges of distribution (ORD) for the water variables were water depth, -2 to 10 cm; dissolved oxygen, 0.99-3.55 mg/kg, conductivity (CON), 23.40-115.40 ${\mu}s/cm$, total dissolved solid, 12.53-57.60 mg/L; pH, 5.00-6.87; $K^+$, 0.11-1.46 mg/L; $Ca^{2+}$, 1.53-5.85 mg/L; $Na^+$, 3.16-7.47 mg/L; $Mg^{2+}$, 0.11-1.96 mg/L; $NO_3$-N, < 0.001-0.072 mg/L; $NH_4$-N, 0.005-0.097 mg/L; and $PO_4$-P, 0.006-0.047 mg/L. ORDs for the soil variables were water content, 1.05-2.96%; loss-on ignition method (LOI), 5.07-7.81%; CON, 23.70-59.70 ${\mu}s/cm$; pH, 4.40-5.16; extracted (e) $K^+$, 4.34-15.73 cmol/kg; $eCa^{2+}$, 31.56-191.56 cmol/kg; $eNa^+$, < 0.01-2.61 cmol/kg; eMg, 0.04-19.82 cmol/kg; $eNO_3$-N, 0.514-1.175 mg/kg; $eNH_4$-N, 0.033-0.974 mg/kg, $ePO_4$-P, 0.491-11.552 mg/kg; total nitrogen, 0.016-0.200%; and total carbon, 1.06-2.37%. The appearance of rush during early succession indicated relatively lower levels of these physicochemical parameters, and that ORDs should be maintained for the J. effusus community.

• Korean Journal of Microbiology
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• v.51 no.2
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• pp.133-140
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• 2015

We have examined the correlation between the physicochemical and microbiological environment variables for the different layers of oak forest soil in Mt. Gyeryong, Korea. The result shows that there is a high correlation in the environment variables between the soil parameters of the fermented (F) layer and humus (H) layer. In particular, the pH level in the F layer shows a high correlation with C and N, while the various organic acids of the H layer turns out to be closely correlated with soil bacteria density. As we evaluated phylogenetic characteristics of bacterial populations by DGGE analysis with DNA extracted. Total of 175 bands including 43 bands from litter (L) layer, 42 bands from F layer, 43 bands from H layer and 47 bands from rhizosphere (A) layer were selected as the major DGGE band of oak forest soil. Based on the 16S rRNA gene sequences, 175 DGGE bands were classified into 32 orders in 7 phylum. The heat map was analyzed in order to compare the quantity of the base sequences of each order and based on the clustering of the different layers of oak forest soil, the result confirms that the F layer and H layer belong to a different cluster from that of L layer and A layer. Furthermore, it also showed that approximately 50% of the total microbial population in different layers is ${\alpha}$-proteobacteria, which indicates that they belong to the dominant system group. In particular, Rhizobiales, Burkholderiales and Actinobacteriales were observed in all the seasons and layers of oak forest soil, which confirms that they are the indigenous soil bacterial community in oak forest soil.