• Tunnel and Underground Space
• /
• v.16 no.6 s.65
• /
• pp.526-535
• /
• 2006

An experimental study was carried out on a reduced scale tunnel model to grasp the behavioral feature of fire-induced smoke in the long tunnels. Based on Froude modeling, the 1/50 scaled tunnel model (20 m long) was constructed by acrylic tubes and paraffin gas was released inside the tunnel to simulate the 20 MW fire-induced smoke. me test results show, that after approximately 2 minutes of fire generation, was descended from the tunnel ceiling through the decrease of buoyancy, then it was symmetrically propagated about 90 meters for 4 minutes before jet fans were operated. The smoke was effectively controlled when the jet fans were operated and an air stream velocity was getting closed to reach a critical velocity (the minimum air velocity that requires to suppress the smoke spreading against the longitudinal ventilation flow during the tunnel fire situations). It was also found out that a range of smoke was spreaded about 3 meters from the origin of fire but the range was not propagated to the escape direction anymore. The early stage of the In operation, however, showed that the smoke was hardly controlled. It means that the operation of emergency ventilation system has many dangerous factors such as an intercepting breathing zone.

• Restorative Dentistry and Endodontics
• /
• v.24 no.1
• /
• pp.147-155
• /
• 1999

The purpose of this study was to investigate the effect of phosphoric acid concentration on the movement of 2-hydroxyethylmethacrylate(HEMA) from bonding resin - resin composite combination through dentin in vitro. Freshly extracted human third molar teeth were divided into four groups each of 10 teeth. A closed chamber with 1 ml distilled water was attached to the CEJ of each tooth. An occlusal cavity of 4mm diameter & remaining dentin thickness of 1.0-1.5mm was prepared in each tooth. Dentin was treated with 10% phosphoric acid gel for 15 seconds. 32% phosphoric acid gel for 15 seconds, or with 35% phosphoric acid gel for 15 seconds. A control group not treated with acid gel was also prepared. The cavities were rinsed, dried and then treated with the HEMA-containing All-Bond 2 primer & bonding resin which was light-cured for 10 seconds. The cavities were then restored with Z100 composite resin(shade:A3.5:3M Dent. Prod. USA) & light cured for 30 seconds. Water samples were retrieved from the chambers over a time course (4.32, 14.4, 43.2, 144 & 432 minutes ; 1, 3 & 10 days) and analyzed by high performance liquid chromatography. The results were as follows. 1. HEMA was detected in the pulp chambers of all teeth from 4.32 minutes after resin placement The highest rate of release was in the first sample period (0-4.32 min) & rate of release declined exponentially thereafter. 2. No significant differences were found for mean release rate for HEMA over a time course among the four groups (p>0.05). 3. The diffusion rate was significantly (p<0.05) less for 10% phosphoric acid gel than 32% phosphoric acid gel at the second sample period(4.32-14.4 min). 4. No significant differences were found for cumulative HEMA diffusion among the four groups at 10 days(p>0.05) and mean total(cumulative) release at 10 days for all groups was in the 9 - 16 nmol range. 5. The cumulative release was significantly (p<0.05) less for 10% phosphoric acid gel than 32% phophoric acid gel at the third(14.4-43.2 min) & fourth(43.2-144 min) sample period.

• Biomolecules & Therapeutics
• /
• v.11 no.4
• /
• pp.249-256
• /
• 2003

Pyroligneous liquid(PL) is produced by carbonizing Oak in 350-40$0^{\circ}C$. It is traditionally used for treating stress-related disorder, hepatic disease, immune disorder, G-I disorder and inflammatory disease. The aim of this study is to investigate anti-stress effects of PL. The experiments were performed with the use of young(9 weeks of age) male rats of SD strain and the male ICR mice (20-25 g). Animals of the normal group were not exposed to any stress and the control group were exposed to stress. The rats of the Ginseng, diazepam(BZ) and PL supplementary group were orally administered once a day 100 g of Ginseng extract-kg body weight, 5 mg of BZ/kg body weight and 1 ml of PL100 g body weight and then exposed to stress. The mice of the Ginseng, BZ and PL supplementary group were given water containing 100 g of Ginseng extract/100 ml potable water, 5 mg of BZ/kg 100 ml of drinking water and 10 ml of PL/100 ml of drinking water and exposed to stress. Animals were given materials for 7 days after stabilizing them, and then were given supplementary materials for 5 days with stress. They were stressed by immobilization for 30 minutes and then the animals were exposed to electroshocks for 5 minutes. We recorded stress-related behavioral changes of experimental animals by stressing them using the Etho-vision system and measured the levels of corticosterone in blood While stress suppressed locomotor activity of animals, PL-supplementation partially blocked the stress effect of locomotion in rats and mice, and also partially blocked stress-induced behavioral changes such as freezing, burrowing, smelling and rearing activity in rats and freezing, grooming, tailing and rearing in mice. The staying time of stressed rats and mice in open area decreased and in closed area it increased relatively in elevated plus maze test. However, these changes also partially were blocked by PL-supplementation. PL-supplementation decreased levels of blood corticosterone increased by stress in rats. These results suggest that PL protects partially the living organism from stress attack in some cases.

• Physical Therapy Korea
• /
• v.11 no.3
• /
• pp.11-18
• /
• 2004

This study is aimed at investigating the influence of different quantitative knowledge of results on the measurement error during lumbar proprioceptive sensation training. Twenty-eight healthy adult men participated and subjects were randomly assigned into four different feedback groups(100% relative frequency with an angle feedback, 50% relative frequency with an angle feedback, 100% relative frequency with a length feedback, 50% relative frequency with a length feedback). An electrogoniometer was used to determine performance error in an angle, and the Schober test with measurement tape was used to determine performance error in a length. Each subject was asked to maintain an upright position with both eyes closed and both upper limbs stabilized on their pelvis. Lumbar vertebrae flexion was maintained at $30^{\circ}$ for three seconds. Different verbal knowledge of results was provided in four groups. After lumbar flexion was performed, knowledge of results was offered immediately. The resting period between the sessions per block was five seconds. Training consisted of 6 blocks, 10 sessions per one block, with a resting period of one minute. A resting period of five minutes was provided between 3 blocks and 4 blocks. A retention test was performed between 10 minutes and 24 hours later following the training block without providing knowledge of results. To determine the training effects, a two-way analysis of variance and a one-way analysis of variance were used with SPSS Ver. 10.0. A level of significance was set at .05. A significant block effect was shown for the acquisition phase (p<.05), and a significant feedback effect was shown in the immediate retention phase (p>.05). There was a significant feedback effect in the delayed retention phase (p<.05), and a significant block effect in the first acquisition phase and the last retention phase (p<.05). In conclusion, it is determined that a 50% relative frequency with a length feedback is the most efficient feedback among different feedback types.

• Journal of The Korean Dental Society of Anesthesiology
• /
• v.1 no.1 s.1
• /
• pp.26-31
• /
• 2001

The wide deep penetrating wound of maxillofacial region should be early closed under emergency general anesthesia for the prevention of complications of bleeding, infection, shock & residual scars. But, if the emergency general anesthesia wound be impossible because of pneumoconiosis, obstructive pulmonary disease & hypovolemic shock, early primary closure should be done under local anesthesia by use of much amount of the anesthetic solution. The maximum dose of dental lidocaine (2% lidocaine with 1 : 100,000 epinephrine) is reported to 7 mg/kg under 500 mg (13.8 ampules) in normal adult. But the maximum permissible dose of dental lidocaine can be changed owing to the general health, rapidity of injection, resorption, distribution & excretion of the drug. The blood level of overdose toxicity is above $4.0{\mu}g/ml$ in central nervous & cardiovascular system. The injection of dental lidocaine 1-4 ampules is attained to the blood level of $1{\mu}g/ml$ in normal healthy adult. The duration of anesthetic action in the dental 2% lidocaine hydrochloride with 1 : 100.000 epinephrine is 45 to 75 minutes and the period to elimination is about 2 to 4 hours. Therefore, authors selected the following anesthetic methods that the first injection of 6 ampules is applied into the deeper periosteal layer for anesthetic action during 1 hour, the second injection into the deeper muscle & fascial layer, the third injection into the superficial muscle and fascial layer, the fourth injection into the proximal skin & subcutaneous tissue and the fifth final injection into the distal skin & subcutaneous tissue. The total 26-28 ampules of dental lidocaine were injected into the wound as the regular time interval during 5-6 hours, but there were no systemic complications, such as, agitation, talkativeness, convulsion and specific change of vital signs and consciousness.

• The Journal of Korean Physical Therapy
• /
• v.26 no.5
• /
• pp.365-371
• /
• 2014

Purpose: The aim of this study is to examine the effects of training in vestibular sensory stimulation on balance and gait of stroke patients. Methods: Twenty patients were randomly assigned to either the experimental group (n=10) or the control group (n=10). Patients in the experimental group received rotational stimulation training, vertical-horizontal stimulation training, gait training on a flat surface with vestibular sensory stimulation, and gait training on soft ground with vestibular sensory stimulation. Patients in the control group received general treadmill gait training. The intervention was applied four times per week, 25 minutes each time, for a period of four weeks. We measured Berg Balance Scale (BBS), Biodex Balance System, Timed up to Go (TUG) test and Dynamic Gait Index (DGI) to evaluate balance and gait ability. Results: BBS differed significantly in both groups between before and after the intervention (p<0.05) and changes in BBS after the intervention differed between the two groups (p<0.05). According to the Biodex Balance System test result, only the experimental group showed significant changes in balance in the conditions of static eyes open (SEC), dynamic eyes open (DEO), and dynamic eyes closed (DEC) (p<0.05). TUG test results differed significantly between prior to and after the training in both the experimental group and the control group (p<0.05) and changes in TUG after the intervention differed significantly between the two groups (p<0.05). DGI results showed significant change after the intervention in the experimental group only (P<0.05). Conclusion: Training in vestibular sensory stimulation was effective in improving static-dynamic balance and gait ability of stroke patients.

• Physical Therapy Korea
• /
• v.8 no.3
• /
• pp.43-52
• /
• 2001

This study was designed to determine the effect of ankle taping and short period of walking on the treadmill on the range of motion (ROM) and proprioception at the ankle joint. Twenty healthy male subjects (mean age=24.2 yr) participated in this study. Goniometry and videotape replaying method were used to measure the ankle ROM. Passive sagittal and frontal plane motions were measured. The difference in degree between the stimulus point and the reproduced point was defined as an angular error. The measurements were performed at four different phases: pre-taping (PRT), post-taping immediately (POT), post-5 minute walking with taping (P5M), and post-10 minute walking with taping (P10M). The ankle of dominant limb was taped by a certified athletic trainer using a closed basket weave technique. Participants walked on the treadmill at 2.5 mph. The results showed that the mean of the sagittal plane motion at PRT, POT, P5M, and P10M was 53.0, 30.5, 36.2, and 40.2 degrees, respectively. The frontal plane motion at PRT, POT, P5M, and P10M was 33.6, 13.9, 15.7, and 18.6 degrees, respectively. The angular error at PRT, POT, P5M, and P10M was 5.5, 1.6, 1.8, and 1.9 degrees, respectively. After 10 minutes of walking, the sagittal plane motion and frontal plane motion was increased by 9.7 and 4.7 degrees compared with POT, respectively. The proprioception was significantly improved after the application of ankle taping. Both the restriction of frontal plane motion and proprioception improvement at the ankle joint may contribute to ankle stability during walking.

• Journal of Gastric Cancer
• /
• v.15 no.4
• /
• pp.278-285
• /
• 2015

Purpose: Gastric submucosal tumors (SMTs) located very close to the esophagogastric junction (EGJ) are a challenge for gastric surgeons. Therefore, this study reports on the experience of using endoscopic and laparoscopic full-thickness resection (ELFR) with laparoscopic two-layer suturing in such tumors. Materials and Methods: Six patients with gastric SMTs very close to the EGJ underwent ELFR with laparoscopic two-layer suturing at Kyungpook National University Medical Center. With the patient under general anesthesia, the lesser curvature and posterior aspect adjacent to the EGJ were meticulously dissected and visualized using a laparoscopic approach. A partially circumferential full-thickness incision at the distal margin of the tumor was then made using an endoscopic approach under laparoscopic guidance. The SMT was resected using laparoscopic ultrasonic shears, and the gastric wall was closed using two-layer suturing. Thereafter, the patency and any leakage were checked through endoscopy. Results: All the ELFR procedures with laparoscopic two-layer suturing were performed successfully without an open conversion. The mean operation time was $139.2{\pm}30.9$ minutes and the blood loss was too minimal to be measured. The tumors from four patients were leiomyomas, while the tumors from the other two patients were gastrointestinal stromal tumors with clear resection margins. All the patients started oral intake on the third postoperative day. There was no morbidity or mortality. The mean hospital stay was $7.7{\pm}0.8$ days. Conclusions: ELFR with laparoscopic two-layer suturing is a safe treatment option for patients with an SMT close to the EGJ, as major resection of the stomach is avoided.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.36 no.5
• /
• pp.408-412
• /
• 2010

Introduction: This study examined the depth of sedation and the usefulness of the monitoring tool in determining the level of sedation in patients undergoing third molars extraction under conscious sedation with midazolam. Materials and Methods: Twenty two patients undergoing third molars extraction at the department of Oral and Maxillofacial surgery, Ewha Womans Mokdong Hospital from February 2010 to April 2010 were analyzed. All patients were classified as American Society of Anesthesiologist (ASA) class I and had no contraindications tosedation. The bispectral index was recorded continually during surgery using a bispectral monitor. The initial sedation was accomplished using a 3 mg bolus of midazolam followed by a 2 mg bolus of midazolam until the level of sedation, at which the patient’s eyes were closed or the subject was responsive only to loud or repeated calling of their name, was reached. All subjects were surveyed with a postoperative questionnaire to evaluate the level of sedation. Results: The bispectral index (BIS) decreased approximately 5 minutes after midazolam administration, but increased at the local anesthesia injection and odontomy procedure. The amnestic effect was shown effectively in the early stages of surgery. Conclusion: Conscious sedation with intravenous midazolam is effective in achieving the effect of anxiolysis, analgesia and amnesia. The BIS is an objective and useful means of assessing the depth of sedation.

• KEPCO Journal on Electric Power and Energy
• /
• v.8 no.1
• /
• pp.43-48
• /
• 2022

Although the distribution system has been structured as complicated as a mesh in the past, the connection points for each line are always kept open, so that it is operated as a radial distribution system (RDS). For RDS, the line utilization rate is determined according to the maximum load on the line, and the utilization rate is usually kept low. In addition, when a fault occurs in the RDS, a power outage of about 3 to 5 minutes occurs until the fault section is separated, and the healthy section is transferred to another line. To improve the disadvantages of the RDS, research on the construction of a networked distribution system (NDS) that linking multiple lines is in progress. Compared to the RDS, the NDS has advantages such as increased facility utilization, load leveling, self-healing, increased capacity connected to distributed generator, and resolution of terminal voltage drop. However, when a fault occurs in the network distribution system, fault current can flow in from all connected lines, and the direction of fault current varies depending on the fault point, so a high-precision fault current direction determination method and high-speed communication are required. Therefore, in this paper, we propose an accurate fault current direction determination method by comparing the peak value polarity of the fault current in the event of a fault, and a communication-based protection coordination method using this method.