• Journal of ILASS-Korea
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• v.16 no.3
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• pp.134-139
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• 2011

Recent research has focused on engine combustion technology as well as application of after-treatment in order to comply with emission regulation. However, it is much more efficient way to control emissions from engine itself and furthermore research on engine control will provide the direction of after-treatment technology in future. Furthermore, emission standard regulation for passenger diesel vehicles has been stringent compared to others and nano-particles will be included in EURO6 regulation in Europe and similar emission standard will be introduced in Korea. A 3.0 liter high speed diesel engine equipped with by CRDI system of 160MPa injection pressure, and an intake/exhaust system of V type 6 cylinder turbo-intercooler was applied. The injection duration and injection quantity, pilot injection types which are related to CRDI and air/fuel ratio control applied by EVGT were changed simultaneously. Standard experiment procedure constituted dilution apparatus and CPC system to collect nano-particles and these test results were compared with regulated materials of CO, HC, NOx and investigated their relations and characteristics of nano-particles.

• Journal of ILASS-Korea
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• v.12 no.1
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• pp.30-37
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• 2007

Dimethyl ether (DME) as an alternative fuel for compression ignition engine was investigated by measuring spray development processes, injection rate profiles, engine performance, and exhaust emission characteristics. The results of DME fueled engine were compared with those obtained by fueled with diesel. The experimental results showed that DME has approximately 0.03ms shorter injection delay and higher maximum injection rate than those of diesel fuel at a constant injection pressure of 50MPa. The spray visualization indicates that DME has shorter spray tip penetration due to its low density and faster evaporation. The combustion characteristics of DME operated engine provided faster ignition delay and three times shorter combustion duration. It is believed that the better evaporation and atomization characteristic of DME contributes the faster combustion. At all operating condition, soot emission was not detected due to the clean combustion of DME.

• Journal of Veterinary Clinics
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• v.5 no.1
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• pp.37-42
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• 1988

The effect of yohimbine HCI(0.25mg / kg) on xylazine(0.15mg /kg) induced depression of rumen motility was investigated by means of electromyography of luminal wall in korean native goats. Yohimbine was administrated 5 min pre-xylazine injection, 5 min and 15 min after xylazine injection. The duration of lumen motility in cases of xylazine alone administration, yohimbine administration 5 min pre-xylazine injection, 5 min post-xylazine, and 15 min post-xylazine was 47-64, 36-40, 28-29, and 15-17 min, respectively. It is demonstrated that lumen contractions were inhibited by xylazine and the inhibition was most rapidly reversed by the administration of yohimbine 15 min after xylazine injection in which goat was completely sedated.

• The Korean Journal of Pain
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• v.7 no.2
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• pp.231-237
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• 1994

Epidural steroid injection is a treatment for low back pain which allows smaller doses with less risk of side effects and longer duration of relief than systemic administration. From 1 June 1992 to 31 January, 1994, 1 mg/kg of triamcinolone diacetate in 8 ml of lidocaine 1% was administered 56 times to 33 patients who complained of low back pain. Results of epidural steroid injection provided effectiveness in treating various low back pain diseases except postlaminectomy syndrome. However there are no gains about repeated epidural steroid injection.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.6
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• pp.76-84
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• 2001

Generally fuel injection system using solenoid have some problems between control signal and mechanical movement like as time lag. Main purpose of the present study is to help the design optimization of GDSI for real engine application. We have adopted two different solenoid driving circuit, namely saturation and pick-hold type and have investigated experimentally the current, needle force, needle opening duration and injection quantity. The pick-hold type driving circuit surpassed a saturation type in the response time and pression control of injection quantity. Accordingly, Using characterization data of operating factors such as time constant, driving force and so on, can be evaluated and adjusted to obtain an optimum injector performance.

• Archives of Plastic Surgery
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• v.36 no.3
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• pp.283-288
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• 2009

Purpose: Frey's syndrome is a common complication after parotid surgery and characterized by gustatory sweating and flushing in the periauricular area during meals. Although a variety of methods have been proposed to prevent this postoperative problem but they have been unsatisfactory. In this article, therefore, botulinum toxin A was used to treat nine patients with Frey's syndrome and its duration effect after injection was investigated. Methods: Nine patients became the object of study about the effect of botulinum toxins as treatment of Frey's syndrome. Age of patients ranged from 25 to 78 years (mean, 43.7 years). Six of nine patients had both symptoms of gustatory sweating and flushing. And the others had only gustatory sweating symptom. Using Minor starch iodine test, the affected skin area was detected, and it was marked by $1cm^2$ sized grid appearance. After application of EMLA cream on the gustatory sweating area, botulinum toxin A was injected intracutaneously into the affected skin area ($2.5U/cm^2$). Patients were followed up from six to fifteen months (mean, about 12 months) and asked about improvement of their symptoms. Results: The treatement with botulinum toxin A took effective within two days after injection. Six months after injection, gustatory sweating disappeared completely in all patients, and five of six patients who had gustatory flushing improved in their symptom. Last follow-up, no patients complained of recurrent gustatory sweating and flushing except one. One patient, seven months after initial injection, was retreated with botulinum toxin A because of recurrence, and the result was successful. The duration of the effect after botulinum toxin A treatment was ranged from seven to thirteen months. One patient in our series experienced the upper eyelid weakness as adverse effect, but it improved spontaneously. Conclusion: Local injection of botulinum toxin A is an effective, safe and long - lasting method for treatment of Frey's syndrome. Hereafter, however, additional study will be required to evaluate the duration effect of botulinum toxin A according to frequency in use and dosage.

• Journal of ILASS-Korea
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• v.6 no.2
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• pp.16-21
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• 2001

This paper describes the macroscopic behavior and atomization characteristics of the high-pressure gasoline swirl injector in direct-injection gasoline engine. The global spray behavior of fuel injector was visualized by shadowgraph technique. The atomization characteristics of gasoline spray such as mean diameter and mean velocity of droplets were measured by the phase Doppler particle analyzer system. The macroscopic visualization and experiment of particle measurement on the fuel spray were investigated at 7 and 10 MPa of injection pressure under different spray cone angle. The results of this work show that the geometry of injector was more dominant over the macroscopic characteristics of spray than the fuel injection pressure and injection duration. As for the atomization characteristics, the increase of injection pressure resulted in the decrease of fuel droplet diameter and the atomization characteristics differed as to the spray cone angle. The most droplets had under $25{\mu}m$ diameter and for the large droplets(upper $40{\mu}m$) as the spray grew the atomization presses were very slow. Comparison results between the measured droplet distribution and the droplet distribution functions revealed that the measured droplet distribution is very closed to the Normal distribution function and Nukiyama-Tanasawa's function.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.2
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• pp.97-103
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• 2010

The four combustion stages in a diesel engine have close correlation among them. Especially, the ignition delay period has significant effect on the following combustion stage. And the period is also one of inevitable combustion processes in the diesel engine. For example, the diesel knocking is a well-known phenomenon due to the long ignition delay period. The interval of the ignition delay period is affected by the mixture formation process in the cylinder. However, in the case of the D.I. diesel engine, the available duration to make the mixture formation of air-fuel is very short. In addition, the means of the mixture formation mainly depends on the injection characteristics and properties of the fuel. It is difficult to make complete mixture. Therefore, an early stage of combustion is violent, which leads to the weakness of noise and vibration. In this study, using the visible engine, we measured the ignition delay period by photo sensor which detect occurrence of flame and presented the factors of the injection characteristics such as kinds of injection system, the injection pressure and the injection timing. The relation between the ignition delay period and cylinder pressure diagram which was concurrently obtained was also estimated.

• Archives of Plastic Surgery
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• v.36 no.5
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• pp.654-659
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• 2009

Purpose: A botulinum toxin type A (BoNT - A) injection has been used as a noninvasive management for lower face contouring since 2000. The aim of this study was to compare reduction rate of lower face width for a longtime according to repeated Botox$^{(R)}$ injections on masseter muscles for lower face contouring procedure. Methods: Forty - five patients were analyzed for single session of Botox$^{(R)}$ injection and 13 patients were evaluated for repeated Botox$^{(R)}$ injections for over two years. Single injection group was tracked regular intervals at 1, 3, 6, 10, 12 months after injection, and repeated injection group was measured at every injection time. Twenty - five to thirty units of Botox$^{(R)}$ was injected into each masseteric muscle at five to six points at the prominent portions of the mandibular angle. Standardized frontal view of digital photographs were analyzed by Adobe Photoshop$^{(R)}$ (version CS3) to measure an reduction rate of lower face width. Results: Reduction rate was 3.7%, 6.9%, 6.2%, 4%, 4% at 1, 3, 6, 10, 12 months post injection each other in single injection group. However, more than 8% reduction rate was found in repeated injection group persistently for more than two years. Conclusion: This study shows that effective duration of Botox$^{(R)}$ injection for lower face contouring is expected to continue over one year clinically. Moreover, repeated injections maintained lower reduction rate consistently for a long time. Therefore, repeated injections on masseter muscles at regular intervals are most effective procedure for lower face contouring.

• Journal of Dental Anesthesia and Pain Medicine
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• v.15 no.4
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• pp.201-205
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• 2015

Background: This prospective, randomized, double-blind, clinical study was conducted to compare the effects of 4% articaine with 1:100,000 epinephrine (A100) and 4% articaine with 1:200,000 epinephrine (A200) on the vital signs and onset and duration of anesthesia in an inferior alveolar nerve block (IANB). Methods: In the first appointment, an IANB was performed by injecting A100 or A200 in 1 side of the mouth (right or left) randomly in patients referred for extraction of both their first mandibular molars. In the second appointment, the protocol was repeated and the other anesthetic solution was injected in the side that had not received the block in the previous session. Systolic and diastolic blood pressures (SBP and DBP) and pulse rate were measured during and 5 min after the injection. The onset and duration of anesthesia were also evaluated. Data were analyzed using t-test and Mann-Whitney U-test, and p-value was set at 0.05. Results: SBP and pulse rate changes were slightly more with A100; however, DBP changes were more with A200, although the differences were not significant (P > 0.05). There were no statistically significant differences in the parameters evaluated in this study. The onset and duration of anesthesia, and the changes in SBP, DBP, and pulse rate during and 5 min after the injection were the same in both the groups. Conclusions: For an IANB, A200 and A100 were equally efficient and successful in producing the block. Epinephrine concentration did not influence the effects of 4% articaine.