• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.2
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• pp.125-134
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• 2015

This is the third paper on the combustion characteristics of the landfill gas in a constant volume combustion chamber for a large displacement volume commercial engine. It is the first in this series to discuss the effects of the torch device on combustion. The results show that an optimum orifice ratio exists regardless of the torch volume, and a few adverse effects on the combustion are observed for an excessively small orifice ratio. In addition, the torch ignition decreases the initial burn duration, and the decrease in the heat transfer caused by this decreased duration contributes to an increase in the peak combustion pressure. Finally, the torch mostly plays a positive role in shortening the main burn duration when the combustion condition is worsened by a lower methane fraction. Yet, the torch decreases the initial burn duration rather than the main burn as the methane fraction increases.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.6 s.261
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• pp.514-521
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• 2007

This study focused on the effects of the $CO_2$ gas concentration in fresh charge and induction air temperature on the combustion characteristics of homogeneous charge compression ignition with dimethyl ether (DME) fuel, which was injected at the intake port. Because of adding $CO_2$ in fresh charge, start of auto-ignition was retarded and bum duration became longer. Indicated combustion efficiency and exhaust gas emission were found to be worse due to the incomplete combustion. Partial burn was observed at the high concentration of $CO_2$ in fresh charge with low temperature of induction air. However, indicated thermal efficiency was improved due to increased expansion work by late ignition and prolonged bum duration. Start of auto-ignition timing was advanced with negligible change of burn duration, as induction air temperature increased. Burn duration was mainly affected by oxygen mole concentration in induction mixture. Bum duration was increased, as oxygen mole concentration was decreased.

• Journal of the Korean Burn Society
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• v.24 no.1
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• pp.7-13
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• 2021

Purpose: Currently, the most recommended method for burn first aid is the cool running water for 20 minutes (CRW20). If CRW20 is not practicable, cooling dressing products with tea tree oil are used as substitutes. In this study, we analyze the effect of various burn first aids, including CRW20, cooling products, on the treatment period. Methods: This study was conducted on patients who suffered burns and visited Hangangsoo Hospital from March 2019 to March 2020. The study conducted in a retrospective method. The duration of treatment was analyzed by dividing the experimental group. Results: The treatment period was shortened when first aid was given (P<0.001). Cold water, ice, and ice packs resulted in reduced treatment periods (P<0.001, P=0.004). The treatment period was reduced when cooling dressing products were used in all groups (P=0.041). The implementation of first aid has reduced the duration of burn treatment. This means that cooling helps burn treatment. CRW20 did not show statistically meaningful results. This is the result of a failure to fully control the temperature and time of tap water. In addition, the change in temperature of tap water according to season, the use of water is higher than that of animal testing, and the general lack of information on proper burn first aid may have affected. Conclusion: The treatment period was statistically significantly reduced in the group that performed first aid. Among the various first aid methods, cold water and ice reduced the treatment period.

• Archives of Plastic Surgery
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• v.41 no.4
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• pp.317-324
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• 2014

Background Burn infliction techniques are poorly described in rat models. An accurate study can only be achieved with wounds that are uniform in size and depth. We describe a simple reproducible method for creating consistent burn wounds in rats. Methods Ten male Sprague-Dawley rats were anesthetized and dorsum shaved. A 100 g cylindrical stainless-steel rod (1 cm diameter) was heated to $100^{\circ}C$ in boiling water. Temperature was monitored using a thermocouple. We performed two consecutive toe-pinch tests on different limbs to assess the depth of sedation. Burn infliction was limited to the loin. The skin was pulled upwards, away from the underlying viscera, creating a flat surface. The rod rested on its own weight for 5, 10, and 20 seconds at three different sites on each rat. Wounds were evaluated for size, morphology and depth. Results Average wound size was $0.9957cm^2$ (standard deviation [SD] 0.1845) (n=30). Wounds created with duration of 5 seconds were pale, with an indistinct margin of erythema. Wounds of 10 and 20 seconds were well-defined, uniformly brown with a rim of erythema. Average depths of tissue damage were 1.30 mm (SD 0.424), 2.35 mm (SD 0.071), and 2.60 mm (SD 0.283) for duration of 5, 10, 20 seconds respectively. Burn duration of 5 seconds resulted in full-thickness damage. Burn duration of 10 seconds and 20 seconds resulted in full-thickness damage, involving subjacent skeletal muscle. Conclusions This is a simple reproducible method for creating burn wounds consistent in size and depth in a rat burn model.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3282-3287
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• 2007

Lean combustion is one of the most promising method for increasing engine efficiency and reducing the exhaust emission from SI gas engines. Due to the possibility of partial burn and misfire, however, under lean burn operation, stable flame kernel formation and fast burn rate are needed to guarantee a successful subsequent combustion. Experiment data were obtained on a single-cylinder CNG fueled SI engine to investigate the effect of direct injection, spark timing and variation of injection timing. Experimental results show that lean burn limit is ${\lambda}$=1.3 with port injection, and expansion of lean burn limit ${\lambda}$=1.4 with direct injection method, due to increase of turbulence intensity in cylinder and stratified charge. Combustion duration in lean region is improved by using the variation of injection timing.

• Journal of Trauma and Injury
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• v.22 no.2
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• pp.227-232
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• 2009

Purpose: Numerous experimental studies have shown the benefits of treating thermal burns by cooling. Nevertheless, few studies have shown the clinical effect of cooling therapy on thermal burns. This study aimed to identify the clinical effect of immediate cooling therapy. Methods: The research was conducted as a retrospective, case-control study. All patients had thermal injuries characterized as a superficial second-degree burn. In the cooling group, 14 patients had first-aid cooling therapy delivered by either parents, caregivers, general practitioners, local hospitals, and/or Myongji hospital. Included in the study were 22 control patients who were not treated with any cooling therapies. Other clinical factors, such as age, sex, cause of burn injury, and burn area (Total Body Surface Area %), were taken into consideration. The duration of treatment was defined as the time from the occurrence of the injury to the presence of complete re-epithelialization, as confirmed by two surgeons. Results: The duration of treatment in the cooling group was significantly less than that the control group (p<0.05). Conclusion: Cooling therapy as an initial emergent treatment is clinically effective for superficial second-degree burn injuries.

• Archives of Plastic Surgery
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• v.36 no.5
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• pp.578-582
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• 2009

Purpose: In extensive deep burn of the lower limb, due to less amount of soft tissue, bone is easily exposed. When it happens, natural healing or reconstruction with skin graft only is not easy. Local flap is difficult to success, because adjacent skins are burnt or skin grafted tissues. Muscle flap or free flap are also limited and has high failure rate due to deep tissue damage. The authors acquired good outcome by performing one - stage operation on bone exposed soft tissue defect with AlloDerm$^{(R)}$(LifeCell, USA), an acellular dermal matrix producted from cadaveric skin. Methods: We studied 14 bone exposed soft tissue defect patients from March 2002 to March 2009. Average age, sex, cause of burn, location of wound, duration of admission period, and postoperative complications were studied. We removed bony cortex with burring, until conforming pinpoint bone bleeding. Then rehydrated AlloDerm$^{(R)}$(25 / 1000 inches, meshed type) was applicated on wound, and thin split thickness(6 ~ 8 / 1000 inches) skin graft was done at the immediately same operative time. Results: Average age of patients was 53.6 years(25 years ~ 80 years, SD = 16.8), and 13 patients were male(male : female = 13 : 1). Flame burn was the largest number. (Flame burn 6, electric burn 3, contact burn 4, and scalding burn 1). Tibia(8) was the most affected site. (tibia 8, toe 4, malleolus 1, and metatarsal bone 1). Thin STSC with AlloDerm$^{(R)}$ took without additional surgery in 12 of 14 patients. Partial graft loss was shown on four cases. Two cases were small in size under $1{\times}1cm$, easily healed with simple dressing, and other two cases needed additional surgery. But in case of additional surgery, granulation tissue has easily formed, and simple patch graft on AlloDerm$^{(R)}$ was enough. Average duration of admission period of patients without additional surgery was 15 days(13 ~ 19 days). Conclusion: AlloDerm$^{(R)}$ and thin split thickness skin graft give us an advantage in short surgery time and less limitations in donor site than flap surgery. Postoperative scar is less than in conventional skin graft because of more firm restoration of dermal structure with AlloDerm$^{(R)}$. We propose that AlloDerm$^{(R)}$ and thin split thickness skin graft could be a solution to bone exposured soft tissue defects in extensive deep burned patients on lower extremities, especially when adjacent tissue cannot be used for flap due to extensive burn.

• Aerospace Engineering and Technology
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• v.13 no.1
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• pp.96-107
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• 2014

Korea Aerospace Research Institute has a plan to launch experimental lunar orbiter in 2017, and lunar orbiter and lander in 2020. In the mission planning phase, LOI(Lunar Orbit Insertion) maneuver strategy should be designed using finite burn model because on-board propulsion system of lunar orbiter in finite burn type. LOI maneuver plan and amount of required ${\Delta}V$ using finite burn model depend on the spacecraft attitude at burn, a type of propellant, thrust level and burn timing. This paper describes the LOI maneuver of lunar orbiter of foreign space agency and then comes up with the LOI maneuver plan of Korean lunar orbiter. Adequate thrust level and burn duration of Korean lunar orbiter also present by performing simulation.

• Journal of Korean Academy of Rural Health Nursing
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• v.1 no.1
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• pp.40-48
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• 2006

Purpose: This study was done to identify the experience of stress and burn-out in caregivers of patients with senile dementia. Method: To evaluate the degree of stress and burn-out in caregivers of patients with senile dementia, 64 caregivers and matched to 64 patients with senile dementia at a Primary Health Care Post in South Kyung Sung Province were selected. The study was carried out from March 6 to March 30, 2001. Data on the degree of dementia in the patients was measured by the MMSE-K (Mini-Mental State Examination-Korea) and caregiver characteristics such as, sex, age, marital status, educational level, job, socioeconomic status, religion, number in family, relationship with patient, duration of care, and chronic disease in caregiver were collected by direct interview with a questionnaire. Results: Of 64 patients with senile dementia, 15.6% were classified as mild dementia (MMSE score 20-24) and 84.4%, as severe dementia. There were no significant characteristics of caregivers associated with the degree of stress and burn-out experience. The degree of burn-out in these caregivers of patients with severe dementia (mean value 94.3) was significantly higher than the 81.4 for those caring for patients with mild dementia (p<0.05). However, the degree of stress was not significantly related with the degree of dementia. The proportion experiencing severe burn-out (above score 4) was 54.7% in the physical domain, 90.6% in the emotional domain, and 73.4% in psychiatric domain, respectively. Conclusion: The above findings suggest that the degree of stress and burn-out experienced by caregivers of patients with senile dementia are high. Also the degree of burn-out experienced by in caregivers of patients with severe dementia was higher than for those caring for patients with mild dementia.

• Journal of the Korean Burn Society
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• v.23 no.2
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• pp.31-36
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• 2020

Purpose: Scar contracture influence the outcome of burn patients significantly. This study aims to investigate the feasibility of robot-assisted training for the lower extremity rehabilitation of burn patients. Methods: This pilot study was conducted on 7 burn patients for 8 weeks between January 2019 and November 2019. Two of 7 patients withdrew from this study because one had skin abrasion on the legs which thigh fastening devices were applied on and the other was not participate in the assessment at 4 weeks after training. Final 5 patients received gait training with SUBAR^® and numeric rating scale (NRS), 6-minutes walking test, and range of motion in flexion and extension of knee and ankle joint were evaluated before training, 4 weeks and 12 weeks after training. Results: The subjects had a mean age of 51.8±98 years, mean total burn surface area of 30.8±13.7%, mean duration from injury to 1^st assessment of 102.8±39.3 days. Anyone of 5 patients did not have musculoskeletal or cardiovascular side effects such as increased or decreased blood pressure or dizziness. The significant improvement in NRS, gait speed, and range of motion in knee extension and ankle plantarflexion after robotic training (all P<0.05). Conclusion: Robot-assisted training could be feasible for the rehabilitation of burn patients and it could improve muscle strength and range of motion in lower extremities, and gait function.