• Journal of Ginseng Research
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• v.26 no.4
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• pp.191-195
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• 2002

In this study, we like to examine whether Panax ginseng water extract (PGWE) exerts antidiabetic activities in prevention and treatment modes in multiple low dose (MLD) streptozotocin (STZ) (20 mg/kg i.p injection for 5 days) induced diabetic SD rats. In the prevention mode,150 mg/kg of GRWE was administered intraperitoneally with STG for 3 weeks, and this group is called CO 150. In the treatment mode, we started to administer the same dose of PGWE on day 8 and for 3 weeks, and this group is called POST150. PGWE exerted significant hypoglycemic activities in both prevention (normal control, 97 ${\pm}$ 6 mg/dl; diabetic control, 331${\pm}$23; CO150, 211${\pm}$37) and treatment groups (normal control, 128${\pm}$4 mg/dl; diabetic control, 392${\pm}$33: POST150, 263${\pm}$44). Of great importance is the fact that plasma insulin levels in both groups were markedly increased as compared to the diabetic control (normal control,428.7${\pm}$62.1 pg/dl; diabetic control, 167.0${\pm}$91.7; CO150, 377.6${\pm}$68.7 in prevention mode, and in treatment mode normal control 417.9${\pm}$84.6 pg/dl; diabetic control, 166.1${\pm}$104.7; POST150, 315.2${\pm}$47.4). Blood glucose levels were closely associated with plasma insulin levels, and this result may suggest that PGWE showed the activity to enhance insulin secretion as well as preventing destruction of pancreatic islet cells. Food and water intakes were also determined at the last week of treatment i n both groups. Characteristic symptoms of diabetes were significantly improved in both groups. In the prevention mode, water intake (ml/rat/day) in normal control was increased from 30.6${\pm}$1.5 to 122.2${\pm}$3.4 in diabetic control rats. In the CO150-treated group, water intake was dramatically reduced to 68.3${\pm}$4.4 (p<0.001 vs. diabetic control). In the treatment mode, POST-treated group also reduced the water intake from 128.9${\pm}$2.2 to 113.3${\pm}$1.7. Taken together, our data suggest that PGWE showed comparable antidiabetic activities in prevention and treatment modes. Therefore, PGWE may have a potential as a prophylactic as well as therapeutic agent fur type 2 diabetes mellitus (T2DM).

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.10
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• pp.656-661
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• 2011

The amount of water resources that can be used tend to be decreased gradually. In contrast, the rapidly increasing water consumption is a problem that need to be addressed. Renovation and equipment replacement to improve energy efficiency and to reduce expenditure for building usage is required. But the excessive initial investment cost and the prolonged of pay back period may be uneconomical choice. Water usage for cleaning the toilet bowl accounts for 27%of the total water usage. Water-saving valve that can select the amount of water for cleaning toilet bowl can be reduced expenditure. After installing water-saving valve, analysed the economic effects. Water-saving valves compared with flush valves, and researched the amount of water usage. Then analyzed for the economic effects. Water-saving valve was used 5.6 ${\ell}$/time for cleaning toilet bowl. In contrast, flush valve was consumed 8.4 ${\ell}$/time. Water-saving valve's water-saving rate was 33.3%. The initial payback period for Water-saving valve was 459.5 days. By a small investment in water saving valve, the economic benefits can be obtained.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.12
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• pp.782-790
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• 2011

Typical temperature control methods of a cooler for machine tools are hot-gas bypass and compressor variable speed control. The hot-gas bypass system has been widely used to control the cooler temperature in many general industrial fields. On the contrary, the compressor variable speed control is focused on special fields such as aerospace and high precision machine tools which need high precision control. The variable speed control system usually has two control variables such as target temperature and superheat. In other words, the variable speed control system is basically multi-input multi-output(MIMO) system. In spite of MIMO system, the proportional integral derivative(PID) feedback control methodology that based on single-input single-output (SISO) system is generally used for designing the variable speed control system. Therefore, it is inevitable to describe transfer functions for dynamic behaviors of every controlled variables and decide the PID gains with tremendous iteration process. Moreover, the designed PID gains do not provide optimum system performances. To solve these problems, high performance controller design method based on a state space model is suggested in this paper. An optimum controller is designed to minimize both control errors and energy inputs. This method was more simple to describe dynamic behaviors and easier to design the cooler controller which is MIMO system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.708-715
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• 2016

This study examined the effects of an extract of Dendropanax morbifera on blood pressure, Angiotensin II, Angiotensin Converting Enzyme, Aldosterone, and lipid levels of spontaneously hypertensive rats. The groups were as follows: Control group, Hypertension control group, Water extract treated group, Ethanol extract treated group, n- hexane fraction treated group, Ethyl acetate fraction treated group, n- butanol fraction treated group, and Water fraction treated group. The blood pressure, and Angiotensin II, and Angiotensin Converting Enzyme, and Aldosterone levels were lower in the Ethyl acetate fraction treated group than in the hypertension control group. The change in blood pressure was lower in the Water extract treated group, Ethyl acetate fraction treated group, Ethanol extract treated group, n- hexane fraction treated group, and n- butanol fraction treated group than the hypertension control group. The concentration of Angiotensin II was lower in the Ethyl acetate fraction treated group, Ethanol extract treated group, n- hexane fraction treated group, and n- butanol fraction treated group than the hypertension control group(p<0.05). The level of Angiotensin Converting Enzyme was lower in the Ethyl acetate fraction treated group, Ethanol extract treated group, n- hexane fraction treated group, and n- butanol fraction treated group than the hypertension control group. The concentration of Aldosterone was lower in the Ethyl acetate fraction treated group, and n- butanol fraction treated group than the hypertension control group(p<0.05). In addition, the concentration lower in the Water extract treated group, Ethanol extract treated group, n- hexane fraction treated group than the hypertension control group. Overall, the effect of the Dendropanax morbifera extracts might be useful as anti-hypertensive, and functional food agents.

• Journal of Korean Society of Forest Science
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• v.102 no.4
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• pp.571-577
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• 2013

This study was carried out to establish the construction guidelines of soil erosion control structures for a restoration of mountain stream with analysis of water quality around constructed soil erosion control structures in mountain streams. Water pH of the Uidong valleys in Bukhansan (Mt.) was similar between the constructed soil erosion control structures of lower stream areas [pH 6.53(6.25~6.82)] and the non-constructed areas of upper stream areas [pH 6.32(5.73~6.90)]. Mean concentration of dissolved oxygen was also similar between the constructed soil erosion control structures of lower steam areas [10.2 mg/L(9.9~10.4 mg/L)] and the non-constructed areas of upper stream areas [10.3 mg/L (9.6~10.6 mg/L)]. Mean electric conductivity was similar between the lower [$63.9{\mu}S/cm$ ($32.6{\sim}120.4{\mu}S/cm$)]a nd the upper stream areas [$62.2{\mu}S/cm$ ($40.3{\sim}89.5{\mu}S/cm$)]. Mean concentration of anions was also similar between the lower [15.94 mg/L (3.43~7.98 mg/L)] and the upper stream areas [14.51 mg/L (2.56~4.29 mg/L)]. Water pH of the Honggei valleys in Sancheong-gun was similar between the lower [pH 6.86(6.50~7.10)] and the upper stream areas [pH 6.89(6.61~7.12)]. Mean concentration of dissolved oxygen was also similar between the lower [11.9 mg/L(11.5~12.3 mg/L)] and the upper stream areas [12.2 mg/L (11.6~12.6 mg/L)]. Mean electric conductivity was similar between the lower [$633.4{\mu}S/cm$ ($31.6{\sim}34.6{\mu}S/cm$)] and the upper stream areas [$32.7{\mu}S/cm$ ($31.4{\sim}34.3{\mu}S/cm$)]. Mean concentration of anion was also similar to both stream areas [1.0 mg/L (0.1~2.2 mg/L)]. Water quality in the Uidong and the Honggei valleys was not significantly different between the constructed soil erosion control structures of lower stream areas and the non-constructed areas of upper stream areas. It will be needed to study the time-series analysis of water quality before and after the construction of soil erosion control structure the restoration of mountain streams because the water quality in mountain streams could be affected during the construction processes of structures.

• Korean Journal of Dental Materials
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• v.44 no.1
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• pp.61-68
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• 2017

This study evaluated the effects of various cleaning methods on the shear bond strength of zirconia ceramics after saliva contamination. Eighty zirconia disk specimens were divided into 8 groups. All groups were treated with one coat of MDP primer. All specimens (except the negative control) were contaminated with human saliva on the zirconia surface. The positive control went through the bonding procedure immediately after contamination without any cleaning procedure. With the exception of control groups, the remaining six groups were rinsed with water and either applied with MDP recoating (WATER+MDP) or without MDP recoating (WATER). While some were cleaned with a Ivoclean with MDP recoating (IVOCLEAN+MDP) or not applied with MDP recoating(IVOCLEAN), others were cleaned with a 1% NaOCl solution with MDP recoating (NaOCl+MDP) or without MDP recoating (NaOCl). The shear bond strength of all specimens were measured after being stored in distilled water at $37^{\circ}C$ for 24 hours. The data was analyzed statistically by an analysis of ANOVA, Tukey's post hoc test and Student's t-test was used to compare the shear bond strength according to the re-coating of MDP after the cleaning procedure. The positive control group showed the lowest shear bond strength value, and the WATER group and NaOCl group showed no significant difference when compared to the positive control group. The IVOCLEAN group showed significantly higher shear bond strength when compared to Water group and NaOCl group but not with the group of negative control. After rinsing with water or the NaOCl solution, the comparison of the single coating of MDP and re-coating of MDP showed different shear bond strengths but there was no significant difference to the negative control. After rinsing with Ivoclean, there was no significant difference to the negative control regardless of the recoating of MDP. In conclusion, the shear bond strength was affected by the cleansing procedure and Ivoclean was found to be effective regardless of the re-coating of MDP. When water or the NaOCl solution is used to remove surface contaminants, the re-coating of MDP provides a positive effect on cementation.

• Journal of Life Science
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• v.24 no.5
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• pp.543-548
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• 2014

Aquifer recharge and recovery is a technology used to ensure a stable supply of clean water. During the process, river water is injected into a soil aquifer and stored. The stored water is then recovered and used to produce drinking water. It is important to understand quality improvement of the injected water while it is stored in the aquifer. In the present study, a lab-scale column reactor containing saturated-zone soil was employed to mimic an aquifer. The reactor was used to investigate microbial removal of nitrate that is a major inorganic contaminant detected in the Nakdong River. The reactor was introduced with river water that contained nitrate at concentrations (5.07, 6.81, 8.27, and 11.07 mg $NO_3{^-}/l$) detected downstream of the Nakdong River in the past 2 years. The nitrate concentrations decreased during the introduced water is retained in the reactor. Effluent from the reactor contained 1.49 mg $NO_3{^-}/l$ or less and had an average pH of 7.98 regardless of the nitrate concentrations of the influent. However abiotic control reactor showed similar nitrate-concentrations in its influent and effluent. Considering the result of abiotic control, the decreased nitrate concentration observed in the test column suggested that microorganisms in saturated-zone soil removed nitrate in the river water introduced into the reactor. Results of this study will be used to better understand microbial improvement of water quality in aquifer recharge and recovery technology.

• Journal of Bio-Environment Control
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• v.5 no.1
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• pp.65-70
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• 1996

Water potential which is an physical chemistry and thermodynamic indicator expressed water status of plant root, stem and fruit could be use as a useful indicator for growth control of hydroponically grown muskmelon plant. Linear relationship was observed between EC and water potential of nutrient solution, consequently increment of EC related to the decreasing water potential and resulted with the alteration of water potential and solute potential of upper leaves. Rapid reduction in growth was observed in over 5${\mu}{\textrm}{m}$ of Cu concentration in the media and same tendency was recorded in the shoot fresh weight, root dry weight and chlorophyll content. Increment of Cu concentration in the nutrient solution leads to lower the growth rate and then the water potential of upper leaves. Turgor pressure was not affected the growth of hydroponically grown muskmelon and also Cu concentration of nutrient solution was not recognized the direct relationship to the growth characteristics of muskmelon. These results demonstrated that water potential of nutrient solution can be use as an useful indicator for water physiological comparison of plant growth in hydroponically grown muskmelon.

• The Korean Journal of Nuclear Medicine
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• v.27 no.1
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• pp.123-129
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• 1993

Chitosan is known to be one of the natural chelating agents. It is derived from chitin which is a cellulose-like biopolymer distributed widely in nature, especially in shellfish, insects, fungi, and yeast. There are two forms of chitosans, water soluble and insoluble, The purpose of the present study is to investigate whether water soluble chitosan can be applied to reduce the bioabailability of radios-trontium in foods. We compared the effect of water soluble and insoluble chitosans on the absorption of ingested radiostrontium ($^{85}Sr$). Three percent water soluble and insoluble chitosan solutions were given orally, and immediately after $^{85}SrCl_2$ ($0.2{\mu}Ci$) was administered to rats using a orogastric tube. In one group water soluble chitosan solution was given for additional 4 days. And in control group no chitosan was given. Each group consisted of 6 rats. The whole-body retention of $^{85}Sr$, determined by in vivo counting method, was lower in water soluble chitosan group than that of water insoluble chitosan group and that of control. Urinary excretion of $^{85}Sr$ in chitosan-treated rats was higher than that of control. And 5 day ingested group of water soluble chitosan showed least whole body retention of $^{85}Sr$. In conclusion water soluble chitosan was more effective in reducing bioavailability of ingested radiostrontium in the gastrointestinal tract than insoluble chitosan.

• Journal of the East Asian Society of Dietary Life
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• v.14 no.1
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• pp.47-53
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• 2004

The characteristics of dough and the quality of white pan bread with 0∼1.5％ $\pi$-water were investigated. The fermentation volume and weight of the white pan bread with $\pi$-water (0.1％, 0.5％, 1.0％, 1.5％) was higher than that of the control. The volume of white pan bread with $\pi$-water (0.1％, 1.0％, 1.5％) was higher than that of the control. Color L value of crust with $\pi$-water increased from 34.98 to 36.38∼41.36 and increased from 34.32 to 34.90∼43.33 after 3 days. Color a value increased from 14.78 to 14.99∼16.75. The hardness of the white pan bread increased from 29011.0 g/㎤ to 18681.7∼43551.2 g/㎤ as the added amount of $\pi$-water increased. The overall acceptability score of white pan bread was the highest with 0.1％ $\pi$-water.