• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1134-1144
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• 2018

Cetane Number is one of the quality standard for diesel, which assesses the compatibility of ignition quality of diesel compression in diesel engines. Cetane number must be upper 52 to keep the recent diesel quality standards. It is known that if cetane number is high, there will be shorter ignition delay periods than being lower. On the other hands, if cetane number is too high that exceeds the quality standard, there will increase the air pollution and decrease of the fuel efficiency because incomplete combustion. In South Korea, various methods are being used to measure the cetane number such as cetane number that used CFR engine, cetane index from calculate density and distillation temperature and derived cetane number to make up for CFR engine that ignition delay in high temperature is implemented. In this study will be conducted by collecting the diesel from the major oil companies, and try to analyze the correlation between the different methods of cetane number with various factors. At the results of this study, it was shown that the cetane index is high then cetane engine and derived cetane number. therefore it will be necessary to additional research for out of cetane number quality standards.

• Journal of Korea Water Resources Association
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• v.53 no.12
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• pp.1193-1201
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• 2020

This study aims to develop a regression model that estimates a low-flow index that can be applied to ungauged basins. A total of 30 midsized basins in South Korea use long-term runoff data provided by the National Integrated Water Management System (NIWMS) to calculate average low-flow, average minimum streamflow, and low-flow index duration and frequency. This information is used in the correlation analysis with 18 basin factors and 3 climate change factors to identify the basin area, average basin altitude, average basin slope, water system density, runoff curve number, annual evapotranspiration, and annual precipitation in the low-flow index regression model. This study evaluates the model's accuracy by using the root-mean-square error (RMSE) and the mean absolute error (MAE) for 10 ungauged, verified basins and compares them with the previous model's low-flow calculations to determine the effectiveness of the newly developed model. Comparative analysis indicates that the new regression model produces average low-flow, attributed to the consideration of varied basin and hydrologic factors during the new model's development.

• Tuberculosis and Respiratory Diseases
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• v.86 no.2
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• pp.111-119
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• 2023

Background: The objective of this study was to investigate whether alcohol consumption might affect the quality of life (QOL), depressive mood, and metabolic syndrome in patients with obstructive lung disease (OLD). Methods: Data were obtained from the Korean National Health and Nutrition Examination Survey from 2014 and 2016. OLD was defined as spirometry of forced expiratory volume in 1 second/forced vital capacity <0.7 in those aged more than 40 years. QOL was evaluated using the European Quality of Life Questionnaire-5D (EQ-5D) index. Patient Health Questionnaire-9 (PHQ-9) was used to assess the severity of depressive mood. Alcohol consumption was based on a history of alcohol ingestion during the previous month. Results: A total of 984 participants with OLD (695 males, 289 females, age 65.8±9.7 years) were enrolled. The EQ-5D index was significantly higher in alcohol drinkers (n=525) than in non-alcohol drinkers (n=459) (0.94±0.11 vs. 0.91±0.13, p=0.002). PHQ9 scores were considerably lower in alcohol drinkers than in non-alcohol drinkers (2.15±3.57 vs. 2.78±4.13, p=0.013). However, multiple logistic regression analysis showed that alcohol consumption was not associated with EQ-5D index or PHQ-9 score. Body mass index ≥25 kg/m², triglyceride ≥150 mg/dL, high-density lipoprotein <40 mg/dL in men and <50 mg/dL in women, and blood pressure ≥130/85 mm Hg were significantly more common in alcohol drinkers than in non-alcohol drinkers (all p<0.05). Conclusion: Alcohol consumption did not change the QOL or depressive mood of OLD patients. However, metabolic syndrome-related factors were more common in alcohol drinkers than in non-alcohol drinkers.

• Journal of Korean Medicine for Obesity Research
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• v.14 no.2
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• pp.63-71
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• 2014

Objectives: This study was designed to investigate the correlation between Sasang constitution and dyslipidemia and the possibility that Sasang constitution can be a risk factor of dyslipidemia. Methods: This study was a retrospective cross-sectional study based on chart review. Seventeen thousand sixty-nine charts which were collected from May 2007 to June 2010 in International Healthcare Service Center, Kyung Hee University Medical Center, were reviewed for the study. Fifteen thousand two hundred fifty charts including Sasang constitutional diagnosis and lipid profiling were selected and we examined the correlation between Sasang constitution and dyslipidemia. Results: After adjusted for body mass index, the levels of total cholesterol and triglyceride were highest in Taeeum group, and lowest in Soeum group. High-density lipoprotein was highest in Soeum group, and lowest in Taeeum group. After adjusted for age, sex, and body mass index, the odds ratios for 'high triglyceride' were 1.716 (1.411~2.087) in Soyang group and 2.021 (1.650~2.475) in Taeeum group compared to Soeum group. The odds ratio for 'high low-density lipoprotein' was 1.229 (1.006~1.501) in Soyang group compared to Soeum group. The odds ratios for 'low high-density lipoprotein' were 1.195 (1.033~1.381) in Soyang group and 1.414 (1.212~1.649) in Taeeum group compared to Soeum group. Conclusions: The lipid profiles and dyslipidemic risk differed across constitutional types, showing constitution type-specific patterns, so that we could infer the possibility that Sasang constitutional types can be a risk factor of dyslipidemia.

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.708-712
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• 2012

Ionic liquids (ILs) existing as liquid state at room temperature are composed of a immense heterocyclic cation and inorganic anion which is smaller than cation's size. Thus, the species of cation and anion as well as the length of alkyl group on the cation have influence on their physical properties. Their outstanding properties such as non-volatility, thermal stability and wide range of electrochemical stability make these materials excellent candidates for green solvent which can substitute the conventional organic solvents. In this study, ILs based on imidazolium cation have been synthesized such as 1-butyl-3-methylimidazolium bromide ([BMIM][Br]), 1-butyl-3-methylimidazolium chloride ([BMIM] [Cl]), 1-butyl-3-methylimidazolium iodide ([BMIM][I]), and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][$BF_4$]). The density, viscosity, refractive index, heat capacity and ionic conductivity of [BMIM][Br], [BMIM][I], and [BMIM] [$BF_4$] were measured over range of temperature of 293.2 to 323.2 K. The density and refractive index values of [BMIM][I] were the highest among three ILs and the viscosity values of [BMIM][Br] were the highest among three ILs. The heat capacities [BMIM][$BF_4$] were higher than those of [BMIM][Br]. The ionic conductivities of [BMIM][$BF_4$] were higher than those of [BMIM][I].

• Spatial Information Research
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• v.22 no.4
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• pp.49-58
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• 2014

Natural disasters of large scale such as typhoon, heat waves and snow storm have recently been increased because of climate change according to global warming which is most likely caused by greenhouse gas in the atmosphere. Increase of greenhouse gases concentration has caused the augmentation of earth's surface temperature, which raised the frequency of incidences of extreme weather in northern hemisphere. In this paper, we present spatial analysis of future typhoon genesis based on IPCC AR5 RCP 8.5 scenario, which applied latest carbon dioxide concentration trend. For this analysis, we firstly calculated GPI using RCP 8.5 monthly data during 1982~2100. By spatially comparing the monthly averaged GPIs and typhoon genesis locations of 1982~2010, a probability density distribution(PDF) of the typhoon genesis was estimated. Then, we defined 0.05GPI, 0.1GPI and 0.15GPI based on the GPI ranges which are corresponding to probability densities of 0.05, 0.1 and 0.15, respectively. Based on the PDF-related GPIs, spatial distributions of probability on the typhoon genesis were estimated for the periods of 1982~2010, 2011~2040, 2041~2070 and 2071~2100. Also, we analyzed area density using historical genesis points and spatial distributions. As the results, Philippines' east area corresponding to region of latitude $10^{\circ}{\sim}20^{\circ}$ shows high typhoon genesis probability in future. Using this result, we expect to estimate the potential region of typhoon genesis in the future and to develop the genesis model.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.2
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• pp.150-160
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• 2017

Atopic dermatitis (AD) is a chronic inflammatory skin disease. It is characterized by eczematous lesions, skin dryness, and pruritus. The existing treatment drugs for AD have side effects, especially if the drugs are taken for extended periods. Therefore, new alternative therapies are necessary. The aim of this study was to investigate the combined effects of curcumin administration and LED irradiation on AD. AD-like lesions were induced in BALB/c mice by repeated application of 1-chloro-2,4-dinitrobenzene (DNCB) to the shaved skin of the ear and neck. Thirty male BALB/c mice were divided into five groups: vehicle, DNCB, curcumin, LED, and curcumin+LED groups. Curcumin (0.1 g/kg/day) was administrated repeatedly during a period of 14 days (experimental period) and 630 nm LED irradiation ($5J/cm^2/day$) was performed in the acryl box once a day for 10 days, after inducing AD-like lesions via DNCB application. The severity of AD-like lesions was evaluated during the experimental period, using a modified SCORAD index. Both ear and neck skin tissues were examined histologically for epidermal thickness, mast cell, eosinophil counting, and dermal collagen density. Epidermal cell proliferation and apoptosis were detected using immunohistochemistry and TUNEL, respectively. These were all reduced in SCORAD index, epidermal thickness, collagen density, number of mast cell and eosinophil in dermis, and number of proliferating cell and apoptotic cell in epidermis by curcumin administration and 630 nm LED irradiation. Moreover, all parameters were significantly lower in the curcumin+LED group compared with the curcumin group and LED group. These results suggest that the combined therapy of curcumin and LED is more effective than a single treatment. We recommend that this can be a feasible alternative therapy to manage AD.

• Journal of Korean Neurosurgical Society
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• v.61 no.4
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• pp.494-502
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• 2018

Objective : The loosening of pedicle screws (PS) is one of the frequent problems of spinal surgery in the patients with osteoporosis. Previous studies had revealed that intermittent injection of teriparatide could reduce PS loosening by improving bone mass and quality when their patients took parathyroid hormone for a considerable duration before surgery. However, although the teriparatide is usually used after spine surgery in most clinical situations, there was no report on the efficacy of teriparatide treatment started after spine surgery. The purpose of this retrospective study was to examine the efficacy of teriparatide treatment started immediately after lumbar spinal surgery to prevent pedicle screw loosening in patients with osteoporosis. Methods : We included 84 patients with osteoporosis and degenerative lumbar disease who underwent transforaminal interbody fusion and PS fixation and received parathyroid hormone or bisphosphonate (BP) postoperatively. They were divided into teriparatide group (daily injection of $20{\mu}g$ of teriparatide for 6 months, 33 patients, 172 screws) and BP group (weekly oral administration of 35 mg of risedronate, 51 patients, 262 screws). Both groups received calcium (500 mg/day) and cholecalciferol (1000 IU/day) together. The screw loosening was evaluated with simple radiographic exams at 6 and 12 months after the surgery. We counted the number of patients with PS loosening and the number of loosened PS, and compared them between the two groups. Clinical outcomes were evaluated using visual analog scale (VAS) and Oswestry disability index (ODI) preoperatively, and at 12 months after surgery. Results : There was no significant difference in the age, sex, diabetes, smoking, bone mineral density, body mass index, and the number of fusion levels between the two groups. The number of PS loosening within 6 months after surgery did not show a significant difference between the teriparatide group (6.9%, 12/172) and the BP group (6.8%, 18/272). However, during 6-12 months after surgery, it was significantly lower in the teriparatide group (2.3%, 4/172) than the BP group (9.2%, 24/272) (p<0.05). There was no significant difference in the number of patients showing PS loosening between the teriparatide and BP groups. The teriparatide group showed a significantly higher degree of improvement of the bone mineral density (T-score) than that of BP group (p<0.05). There was no significant difference in the pre- and post-operative VAS and ODI between the groups. Conclusion : Our data suggest that the teriparatide treatment starting immediately after lumbar spinal fusion surgery could reduce PS loosening compared to BP.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.9 no.3
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• pp.93-105
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• 2004

Spatio-temporal distribution patterns of the major dominant species were assessed from bimonthly monitoring of macrotidal flat in Cheokjeon, Incheon, Korea between September 1990 and July 1992. Overall, macrofauna comprised a total of 111 species, 25,491 inds.136 ㎡. The result of Le Bris index, dominance ranking of the lead-ing species showed that the top 15 species accounting for 74.8% (19,072 inds.) of total density. In Cheokjeon tidal flat, some species were especially habitat-restricted such as genus Nephtys (Annelids; Polychaetes) and Mac-rophthalmus (Crustaceans; Decapods). Based on the density data, the five dominant species were the polychaetes Het-eromastus filiformis, the bivalves Mactra veneriformis and Solen strictus, the brachyurans Macrophthalmus japonicus, the holothuriodeans Protankyra bidentata. The results of one-way ANOVA, mean value of H. filiformis and M. ven-eriformis did not show significant changes with tidal elevation and sediment composition (p>0.05). But, other species (S. strictus, M. japonicus and P. bidentata) showed significant variations (p<0.001). In conclusion, these indicate significant spatial fluctuation with tidal elevation and sediment characteristics in some species.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.7
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• pp.492-497
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• 2014

This study investigated removal characteristics of organic matters in pretreatment and reverse osmosis (RO) membrane processes for seawater desalination. Also, the influence of the changes in characteristics of organic matters on the membrane fouling was assessed. The pretreatment processes included dual media filtration (DMF), pressurized membrane filtration (MF), and submerged membrane filtration (SMF). Turbidity, UV absorption at 254 nm, dissolved organic carbon, size exclusion chromatography (SEC), fluorescence excitation emission matrix (FEEM), and transparent exopolymer particles (TEP) in raw and processed waters were analyzed. Ions and minerals were not removed by any pretreatment process tested, but were removed over 99% through the RO membrane process. Hydrophobic organics, which can play major role in organic membrane fouling, were relatively readily removed compared with hydrophilic ones. Membrane based pretreatment such as MF and SMF exhibited better removals of organics than conventional DMF. As the levels of organics in pretreated water decreased, the silt density index (SDI) decreased. MF treated water exhibited the lowest SDI value; this is possibly due to the lowest TEP ($0.1-0.4{\mu}m$) concentrations.