• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.123-125
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• 2011

Pre-foaming that has been used in this study is using to control and guarantee quality, but the optimum mix proportion and regulation are not definite. Therefore, this study investigated properties of foamed concrete according to concentrations of foaming agent to improve usability of foamed concrete. Synthetic foaming agent such as AES(Alkyl Ether Sulfate) and AOS(Alpha Olefin Sulfonate) are used to make foam with 1, 3, and 5% concentrations. We found that the flow of foam concrete increases when foam concentration is high and AES is more flowable than AOS. Density and compressive strength increase when foam concentration is low.

• Journal of Nutrition and Health
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• v.31 no.7
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• pp.1130-1138
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• 1998

The objective of this study was to investigate the relationship between changes in body temperature, adiposity and sympathoadrenal activity in normal weight female college students, eating an instant-noodle lunch in a laboratory setting at ambient temperatures of 22-24.8$^{\circ}C$. Preprandial epinephrine(EPI) concentration, as an indicator of adrenal activity, was inversely and significantly correlated with body weight, body mass index(BMI), and waist girth. Changes in pre- and postprandial EPI concentrations showed positive correlations with % body fat, fat mass, waist girth, hip girth, and waist/hip girth ratio(WHR). The preprandial norepinephrine (NE) concentration was negatively correlated with recovery time from the peak postprandial core temperature to the meal-start core temperature(RTST). However, the NE concentration, an indicator of sympathetic neural activity, was not related to anthropometric measurements in normal weight young women. In conclusion, adrenal activity was negatively associated with adiposity and central body fat distribution. Sympathetic activity was related to body temperature regulation capacity after a meal, but was not related to adiposity in normal weight young women. (Korean J Nutrition 31(7) 1130-1138, 1998)

• Reproductive and Developmental Biology
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• v.34 no.3
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• pp.271-274
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• 2010

This study was conducted to investigate the survival rate of frozen-thawed spermatozoa in equine by glycerol concentration and freezing speed Two stallions (1 Thoroughbred-13 year old and 1 Arab-7 year old) bred in Korea Racing authority was examined for 1 times in a couple of weeks. Semen was collected by condom method standing heated mare and were centrifuged 650 g for 15 min. and isolated the seminal plasma. Thick fraction of semen was diluted EDTA-Lactose-egg yolk diluents to 1:1 and contained in 0.5 ml straw as $6{\sim}14{\times}10^7\;cells/ml$. Final concentrations of glycerol were 3, 5 and 7% in cryopreseved diluents and added 4 times for 2 hours equilibration. For the freezing, equilibrated straws were located 3 or 5 em above $LN_2$ gas for 5 or 10 min. Survival rates of pre-frozen sperm were $65.0{\pm}13.2%$, $68.3{\pm}10.4%$, $66.7{\pm}11.5%$ and post-frozen were $53.3{\pm}23.1%$, $45.0{\pm}15.0%$, $50.0{\pm}18.0%$ in 3, 5, 7% glycerol concentration, respectively. There was no difference between glycerol concentrations. Survival rates of frozen-thawed sperm on freezing speed were $36.7{\pm}10.4%$, $40.0{\pm}7.1%$, $30.0{\pm}13.2%$ at 3 cm-5 min and $33.3{\pm}11.5%$, $31.7{\pm}2.9%$, $21.7{\pm}10.4%$ at 3 cm-10 min in 3, 5, 7% glycerol concentration, respectively. Survival rates of frozen-thawed sperm on freezing speed were $43.3{\pm}15.3%$, $32.0{\pm}17.9%$, $22.3{\pm}15.7%$ at 5cm-5 min and were $47.5{\pm}15.0%$, $43.3{\pm}12.6%$, $48.3{\pm}15.3%$ at 5cm-10 min in 3, 5, 7% glycerol concentration, respectively. There were significantly different between groups (p<0.05). These results suggest that glycerol concentration did not affect cryopreservation of stallion semen within 3~7% but freezing speed affects. In our experiment, the best cryopreservation condition was at 5 cm above $LN_2$ gas for 10 min for pre-freezing and 7% of glycerol concentration. These results lead to commercial AI with frozen-thawed stallion semen.

• Journal of Periodontal and Implant Science
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• v.36 no.3
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• pp.653-659
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• 2006

Oral malodor may cause a significant social or psychological handicap to those suffering from it. Oral malodor has been correlated with the concentration of volatile sulfur compounds (VSC) produced in the oral cavity. Specific bacteria identified in the production of VSC have been reported and many of these bacteria are commonly suspected periodontal pathogens. The aim of this study was to estimate the change of the VSC concentration after periodontal treatment, Twenty subjects with probing depth $(PD)\;{\geq}5mm$ (experimental group) and 20 subjects with PD<5mm (control group) participated. VSC concentration measurement was made with gas chromatography. VSC concentration was measured at pre-treatment, 2 weeks after scaling and 1 month after periodontal treatment(root planning and flap operation). Maximum probing depth and bleeding on probing(BOP) were also examed at pretreatment and 1 month after periodontal treatment, The conclusions were as follow: 1. In the experimental group VSC concentration and CH3SH/H2S ratio were higher than control group. (p<0.05) 2. Both VSC concentration and CH3SH/H2S ratio showed decrease after periodontal treatment, But only CH3SH/H2S ratio after 1 month periodontal treatment was statistically significantly different from pre-treatment. (p<0.05) 3. CH3SH/H2S ratio tended to be on increase according to maximum probing depth and bleeding on probing. Periodontal disease could be a factor that caused oral malodor and oral malodor could be decreased after periodontal treatment.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.3
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• pp.37-43
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• 2016

Various mechanical and chemical pretreatment methods including alkali treatment, pre-beating, enzyme treatment and oxidation treatment have been used to reduce the production energy of the microfibrillated cellulose (MFC). Among them, alkali swelling can be helpful to reduce the energy consumption because the internal bonding between fibrils could be weakened. In this study, dimethyl sulfoxide (DMSO) was used as a cosolvent to improve alkali pretreatment efficiency and the effects of NaOH concentration during NaOH-DMSO swelling on changes in fiber characteristics of softwood bleached kraft pulp (SwBKP) were elucidated. For alkali treatment in H2O-DMSO solvents, fiber length were decreased with increasing NaOH concentration while fiber width, curl and WRV were increased. WRV began to increase at 8% NaOH solution. In addition, above 8% concentration of NaOH, crystalline structure of pulp fibers converted from cellulose II to cellulose III by DMSO cosolvent. Comparing the previous results with this study, it was shown that DMSO cosolvent could promote swelling of pulp fibers and thus reduce NaOH concentration for the maximum swelling of fibers.

• Child Health Nursing Research
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• v.12 no.2
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• pp.196-203
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• 2006

Objectives: This study was conducted to test whether stretching helps high school students recover from their fatigue and improve concentration. Method: The method of this study adopted a nonequivalent control group with pre-test and post-test designs. The period of data collection was from November to December in 2004. The 135 subjects were randomly selected from two high schools in Ulsan : one school as control group(n=66) and the other school as an experimental group(n=69). The experimental group had stretching for 10 minutes before the start of their fifth period class, five times a week(once a day) 4weeks of period, but the control group did not do. Result: After stretching, the students' level of fatigue in the experiment group was immensely reduced (t=4.75, p<.001). After the stretching, the concentration level of the experimental group increased vastly compared to the control group (t=3.35, p≤.005). Conclusion: Stretching is useful to reduce fatigue and improve concentration of high school students. This study recommended that stretching, which is not limited by high physical techniques, or specific time or spaces would help high school students' health, since they do not exercise regularly and are tired physically and mentally.

• Journal of the Korean Society of Tobacco Science
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• v.32 no.2
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• pp.88-94
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• 2010

The ether extract(EE) of leaf tobacco contains diverse compounds such as lipid, resinoid, paraffin hydrocarbons and pigments. Although the correlation of EE concentertion with leaf tobacco has not been established clearly, it is known that in some concentration range, EE concentration of leaf tobacco exerts good influence on the quality of tobacco. Recently, The American Oil Chemist's Society introduced new method(Am 5-04; AOCS, 2009) to determine EE concentration by AT15 extractor. This method is based on extraction with organic solvent at relatively high temperature and pressure, which significantly reduces the extraction time and ensures safety. The aim of this study is to optimize analytical condition of AOCS method for analyzing EE concentration of leaf tobacco. When sample pre-drying time and extraction time of XT15 were set to 3 hour and 30 minute and 30 minute respectively, EE concentration obtained from AOAC method. Statistical analysis(T-test) showed that there is no difference(P>0.05) between EE concentrations from two methods.

• Journal of Life Science
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• v.19 no.5
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• pp.625-632
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• 2009

The purpose of this study was to examine the effect of exercise training on nitric oxide (NO) levels, mean arterial pressure (MAP), blood pressure (BP), and heart rate (HR) in college students. 5 subjects were randomly assigned to two experimental groups; an aerobic training group (ATG) and a resistance training group (RTG). In aerobic training, based on measured maximum oxygen consumption rate, 70% exercise intensity was applied and conducted for 60 min. In resistance training, 70% of 1-RM was performed for 90 min. Blood sampling was conducted 3 times during resting state, post-exercise, and after 30 minutes of recovery. The results are as followed. For the post training values of $VO_2max$, % body fat and MAP, there were significant differences in the ATG compared to pre training (p<0.05). However, there were no differences in the RTG between pre and post training. NO increased post training, during rest and at the end of exercise compared to pre training in the ATG (p<0.05). Also, the HR decreased in post training at the end of exercise (p<0.05), however, there were no significant differences in SBP and DBP between pre and post training in the ATG. The HR, SBP and DBP did not change at all in post training compared to pre training in the RTG. In conclusion, an increase in the production of Nitric Oxide (NO) concentration and $VO_2max$, decrease of body fat% and physiological variables (HR, BP, MAP) were shown to be more effective in aerobic training (AT) than resistance training (RT).

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.5
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• pp.453-467
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• 2012

Usage of underground space is increasing at metropolitan city. More than 90% of flood damages have occurred at downtown of metropolitan cities. In order to prevent and/or minimize the flood-induced damage, an underground rainwater detention cavern was proposed to be built underneath existing structures. As for underground caverns to be built for flood control, multi-caverns will be mostly adopted rather than one giant cavern because of stability problem. Because of the stress concentration occurring in the pillars between two adjacent caverns, the pillar-stability is the Achilles' heel in multi-caverns. So, a new pillar-reinforcing technology was proposed in this paper for securing the pillar-stability. In the new pillar-reinforcing technology, reinforced materials which are composed of a steel bar and PC strands are used by applying pressurized grouting, and then, by applying the pre-stress to the PC strands and anchor body. Therefore, this new technology has an advantage of utilizing most of the strength that the in-situ ground can exert, and not much relying on the pre-cast concrete structure. The main effect of the pressurized grouting is the increase of the ground strength and more importantly the decrease of stress concentration in the pillar; that of the pre-stress is the increase of the ground strength due to the increase of the internal pressure. In this paper, ground reinforcing effects were verified the stress change in pillar is obtained by numerical analysis at each construction stage. From these results, the effects of pressurized grouting and pre-stress are verified.

• Advances in Traditional Medicine
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• v.6 no.3
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• pp.186-195
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• 2006

The present study was carried out to determine the involvement of opioid and non-opioid receptor and the effect of pH and enzymes on the recently reported antinociceptive activity of aqueous extract of Corchorus olitorius (AECO) leaves using the abdominal constriction test. The extract was prepared by soaking the dried powdered leaves of Corchorus (C.) olitorius in distilled water overnight, and the supernatant obtained was considered as a stock solution with 100% concentration/ strength. The extract, administered subcutaneously in the concentrations/ strength of 10, 50 and 100%, was found to show a significant concentration-independent antinociception. The 50% concentration AECO were further used to study on the above mentioned parameters. The extract exhibited: significant (P < 0.05) decreased in activity when pre-treated (s.c.) against 10 mg/kg naloxonazine, bicuculine (10 mg/kg), phenoxybenzamine (10 mg/kg), 10 mg/kg pindolol, and 5 mg/kg mecamylamme, but not 10 mg/kg naltrindole, 10 mg/kg atropine, respectively; significant (P < 0.05) decreased in activity after pre-treatment against 10% a-amylase, but not 1 % protease or 10% lipase and; significant (P < 0.05) decreased in activity after exposure to alkaline condition (pH between 9 and 13) while maintaining the activity at acidic condition, respectively. The C. olitorius leaves antinociception, which involved, at least in part, activation of $\mu-opioid,\;\alpha-and\;\beta-adrenergic$, and nicotinic receptors, was found to decrease under alkaline condition and in the presence of $\alpha-amylase$.