• 대한기계학회논문집B
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• 제28권2호
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• pp.160-166
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• 2004

Combustion using oxygen enriched air is known as a technology which can increase flame stability as well as thermal efficiency due to improving the burning rate. Lift-off, blowout limit and flame length were examined as a function of jet velocity, coflow velocity and OEC(Oxygen Enriched Concentration). Blowout limit of the flame below OEC 25% decreased with increase of coflow velocity, but the limit above OEC 25% increased inversely. Lift-off height decreased with increase of OEC. In particular, lift-off hardly occurred in the condition above OEC 40%. Flame length of the flames above OEC 40% was increased until the blowout occurred. Great flame stability was obtained since lift-off and blowout limit significantly increased with increase of OEC.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.326-331
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• 2003

Combustion using oxygen enriched air is known as a technology which can increase flame stability as well as thermal efficiency due to improvement of the burning rate. Lift-off, blowout limit and flame length were examined as a function of jet velocity, coflow velocity and OEC(Oxygen Enriched Concentration). Blowout limit of the flame below OEC 25% decreased with coflow velocity, but the limit above OEC 25% increased inversely. Lift-off height decreased with increase of OEC. Especially lift-off hardly occurred in the condition above OEC 40%. Flame length of the flames above OEC 40% was increased until the blowout occurred. Flame stability became improved since lift-off and blowout limit increased much with increase of OEC.

• Archives of Plastic Surgery
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• 제34권5호
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• pp.599-604
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• 2007

Purpose: Blowout fractures of the orbit are common sequelae to blunt facial trauma and now increasing in number due to automobile accidents, violence and industrial disasters. There are some reports of diagnosis and treatment of this fracture, but detailed data provided in overall aspects are very few. We analysed extensive data to provide guide line of blowout fracture patients care. Methods: We retrospectively studied 387 orbital blowout fracture patients who had been followed up at least 3-6 months. Their hospital records were reviewed according to causes, fracture site, operation methods, and follow up results, etc. Results: The ratio of males to females was 7 : 3 and fractures were most often seen in the 20-29 age group. 180(47%) patients had medial orbital wall fractures, 155(40%) patients had floor fractures and 52(13%) patients had a combination of orbital floor and medial wall fractures. The highest associated bone fracture was the nasal bone(37%). The open reduction was done in the 324 patients(83.7%) and insertion materials were used in the 249 patients(77%). Total 45 patients(14%) complained of residual diplopia and 26 patients(8%) kept mild enophthalmos. 24 patients(7%) showed some restriction of extraocular muscle movements. Conclusion: We broadly surveyed the information of blow out fracture patients and believe that this study provides important prognostic information that can be of benefit to both patient and surgeon during preoperative counseling and postoperative analysis of orbital blowout fractures.

• 대한두개안면성형외과학회지
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• 제11권1호
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• pp.7-12
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• 2010

Purpose: 'White-eye blowout' fracture is often occur in young patients and defined as blow out fracture with little or no clinical sign of soft tissue trauma such as edema, ecchymosis, but with marked motility restrictions in vertical gaze. In this conditions, immediate operation is essential. We reported the clinical investigation study of these cases about clinical symptoms and radiologic findings and introduce our experiences about immediate operations in 'white-eye blowout' fractures. Methods: From January 2008 to December 2009, nine pediatric patients who were diagnosed as pure white-eye blowout fractures were involved this study. Patients with other facial bone fractures or with poor general medical condition were excluded. In all cases, we performed immediate operation within 48 hours. Results: All patients had diplopia, vertical gaze restriction or systemic symptoms. Six patients had nausea, vomiting and syncope caused by oculocardiac reflex. In all patients, preoperative symptoms were improved after immediate operation. There were no postoperative complications such as infection, hematoma or wound dehiscence. Conclusion: When we meet the young patients with history of periocular trauma, with little or no soft tissue trauma signs, but with marked vertical gaze restriction or general symptoms caused by oculocardiac reflex, we should immediately examine by facial bone computed tomography and refer the patient to ophthalmologist for ophthalmic evaluations. If patient is diagnosed as orbital floor fracture with entrapped muscle or soft tissue, the earlier surgical reduction get better clinical outcomes.

• 대한두개안면성형외과학회지
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• 제19권2호
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• pp.102-107
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• 2018

Background: Nasal fracture and orbital blowout fracture often occur concurrently in cases of midface blunt trauma. Generally, these multiple fractures treatment is surgery, and typically, the nasal bone and orbit are operated on separately. However, we have found that utilizing a transconjunctival approach in patients with concurrent nasal bone fracture and orbital blowout fracture is a useful method. Methods: The participants in the present study included 33 patients who visited the Plastic Surgery outpatient department between March 2014 and March 2017 and underwent surgery for nasal fracture and orbital blowout fracture. We assessed patients' and doctors' satisfaction with surgical outcomes after indirect open reduction via a transconjunctival approach for the treatment of nasal bone fracture with associated orbital blowout fracture. Results: According to the satisfaction scores, both patients and doctors were satisfied with transconjunctival approach. Conclusion: We presented here that our method enables simultaneous operation of nasal fracture accompanied by orbital blowout fracture, rather than treating the two fractures separately, and it allows precise reduction of the nasal fracture by direct visualization of the fracture site without any additional incisions or difficult surgical techniques. Also, by preventing the use of excessive force during reduction, this method can minimize damage to the nasal mucosa, thereby reducing the incidence of nasal bleeding.

• Archives of Plastic Surgery
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• 제40권6호
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• pp.721-727
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• 2013

Background One of the main concerns in orbital blowout fracture repair is a narrow operation field, due mainly to the innate complex three dimensions of the orbit; however, a deep location and extensive area of the fracture and soft tissue edema can also cause concern. Swelling of the orbital contents progresses as the operation continues. Mannitol has been used empirically in glaucoma, cerebral hemorrhage, and orbital compartment syndrome for decompression. The authors adopted mannitol for the control of intraorbital edema and pressure in orbital blowout fracture repair. Methods This prospective study included 108 consecutive patients who were treated for a pure blowout fracture from January 2007 to October 2012. For group I, mannitol was administered during the operation. Under general anesthesia, all patients underwent surgery by open reduction and insertion of an absorbable mesh implant. The authors compared postoperative complications, the reoperation rate, operation time, and surgical field improvement between the two groups. Results In patients who received intraoperative administration of mannitol, the reoperation rate and operation time were decreased; however, the difference was not statistically significant. The total postoperative complication rates did not differ. Panel assessment for the intraoperative surgical field video recordings showed significantly improved vision in group I. Conclusions For six years, mannitol proved itself an effective, reliable, and safe adjunctive drug in the repair of orbital blowout fractures. With its rapid onset and short duration of action, mannitol could be one of the best methods for obtaining a wider surgical field in blowout fracture defects.

• Journal of Trauma and Injury
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• 제22권1호
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• pp.97-102
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• 2009

Purpose: Blunt trauma can cause a wide range of ocular injuries. This study was performed to describe the prevalence of severe intraocular injuries (SIOI) and their correlation with the severity of blunt orbital trauma. Methods: We retrospectively analyzed 117 eyes of 107 patients with orbital wall fractures who visited the emergency room at Konyang University Hospital from July 2006 to June 2008. Clinical features such as age, sex, causes of injury, revised trauma score (RTS), type of orbital wall fractures were recorded. The patients were divided into two groups: blowout fracture with severe intraocular injuries (SIOI) and blowout fracture without SIOI. We compared the clinical and the injury-related characteristics between two groups and analyzed the SIOS-related factors. Results: Among the 107 patients (117 eyes) with blowout fractures, 29 (27.1%) patients with 32 eyes (25.6%) had complicated severe intraocular injuries. Retrobulbar hemorrhage (14.5%), hyphema (13.7%), traumatic optic nerve injury (4.3%), and sustained loss of visual acuity (4.3%) were the most common SIOI disorders. A logistic regression analysis revealed that loss of visual acuity (odds ratio = 4.75) and eyeball motility disorder (odds ratio=7.61) were significantly associated with SIOS. Conclusion: We suggest that blowout fracture patients with loss of visual acuity or eyeball motility disorder are mostly likely to have severe intraocular injuries, so they need an ophthalmologic evaluation immediately.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권4호
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• pp.292-300
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• 2004

Orbital blowout fractures are common consequence to blunt periorbital trauma. Pure orbital blowout fractures first occur at the weakest point of the orbital wall. Computed tomography(CT) is recognized to be the best imaging technique to evaluate orbital fractures. The extent and location of a blowout fractures in the CT scan were noted to have an effect on the clinical outcome. In the early posttraumatic period, the presence of significant enophthalmos is difficult to detect because of orbital edema. Early surgical intervention may improve the ultimate outcome because open reconstruction becomes more difficult if surgery is delayed. In this study, we evaluated isolated blowout fractures of the orbital floor by region-of-interest measurements from CT scans and their relationship to ophthalmologic findings. Six patients of the medial orbital wall fractures, eleven patients of the inferior orbital wall fractures, nineteen of the medial and the inferior orbital wall fractures confirmed by CT scan, were evaluated. The area of fracture and the volume of the displaced orbital tissue were determined from CT scan using linear measurements. Each of the calculated values for the area and the volume were compared with the degree of the enophthalmos, the diplopia, and the eyeball movement limitation to determine whether there was any significant relationship between them. The fracture area and the volume of the herniated orbital tissue were significantly positively correlated with the enophthalmos and the ocular motility limitation and not correlated with the diplopia. For the enophthalmos of 2mm or greater, the mean fracture area was 3.55{\pm}1.25cm^2$ and the volume of the herniated orbital tissue was $1.74{\pm}0.97cm^3$; for less than 2mm enophthalmos, $1.43{\pm}0.99cm^3$ and $0.52{\pm}0.49cm^3$, respectively. The enophthalmos of 2mm can be expected with $2.92cm^2$ of the fracture area and $1.40cm^3$ of the herniated orbital tissue. In conclusion, the enophthalmos of 2mm or more, which is a frequent indication for surgery. It can be expected when area of fracture is $2.92cm^2$ or more, or the volume of herniated orbital tissue is $1.40cm^3$ or more. And the CT scan using linear measurements has an application in the assessment of patients with blowout fractures and provides useful information in the posttraumatic evaluation of orbital fractures.

• Archives of Plastic Surgery
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• 제34권6호
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• pp.719-723
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• 2007

Purpose: Blowout fracture can lead to functional impairments and esthetic deformities such as impairment of ocular movement, diplopia, visual loss and enophthalmos. The object of this study is to present a classification and its analysis according to the computed tomographic scan in blowout fractures. We classified blow out fractures into three types according to the anatomical location of fracture, the size of the bone defect and the degree of periosteal injury by using the computed tomography scan. Each progress and complications were analyzed more than mean 1 year. Methods: Among the 155 cases during 4 years, there were 11 cases of medial orbital wall fracture, 97 cases of inferior orbital wall fracture, 47 cases of combined type. The mean age of patients was 31.2 years, ranged from 8 to 84 years. Results: According to our classification, surgical treatments through the nasoendoscopic approach, the subciliary approach, the transconjunctival approach or their combinations were performed in 116 patients, and conservative treatments were done in 46 patients. Presurgical clinical findings of diplopia, impairment of ocular movement, enophthalmos of more than 2 mm were present in 62 patients. After surgical treatment, clinical findings were remained in 7 patients. Conclusion: We think that our classification according to computed tomographic scan is helpful for the indication and it may decrease the complications such as impairment of ocular movement, diplopia, visual loss and enophthalmos.

• 한국연소학회지
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• 제14권2호
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• pp.26-31
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• 2009

Adding small amounts of air to the fuel is used in many commercial combustors to avoid sooty flame. But partially premixed jet flame has lower blowout velocity, $u_{b.o}$, than nonpremixed one. Increasing blowout limit would be one of the key factors to develope highly intense compact combustion devices. Swirling flow enhances fuel and air mixing and induces a highly turbulent recirculation zone, which helps flame stabilization. It was known that NOx emission decreases with swirl on the proper range of swirl number. And it was shown that the flame interaction in multiple jets also increases $u_{b.o}$ owing to the internal recirculation and reduces NO emission. If the effects of swirl and flame interaction are combined together in partially premixed flame, both $u_{b.o}$ increasement and NOx emission reduction could be achieved. Blowout limits of partially premixed interacting propane flame in the swirling air coflow are investigated experimentally. The results show that the flame is not extinguished up to the experimental limits, 210 m/s, at the swirl number of 0.32 and $X_{F,o}$ = 0.46.