• Nuclear Engineering and Technology
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• v.55 no.12
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• pp.4637-4641
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• 2023

For nuclear decommissioning applications, a study was conducted to investigate the feasibility of using a laser for long-distance cutting in complex structures. Cutting tests were performed on stainless steel plates with thicknesses ranging from 10 mm to 30 mm at distances of 300 mm-700 mm from the laser head, using a laser power of 6 kW. Remarkably, the 10 mm and 20 mm thick stainless-steel plates were successfully cut at a distance of 700 mm from the head. Based on the trends observed in the results, it is anticipated that these thicknesses could also be cut at distances of approximately 1 m. Similarly, the 30 mm thick stainless-steel plate was effectively cut at a distance of 500 mm from the head. To evaluate the amount of secondary waste generated, the kerf width was measured. Due to the long-distance cutting, the average kerf width ranged from 6 mm to 16 mm. Despite the wider kerf width, long-distance cutting holds promise for efficiently handling hard-to-reach targets in nuclear decommissioning scenarios.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.06a
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• pp.122-126
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• 2001

Magnetic hard disk drive is continually being pushed to reduce head-disk spacing for higher recording densities. The current minimum spacing between the air-bearing slider and disk has been reduced to under 15 nm. In this work, it was investigated if flying height could be lowered under the height of laser bumps. With the reduction of the spinning speed, the flying height was decreased under the height of laser bumps. When a head swept between landing zone and data zone, the head-disk impact was monitored using AE and friction signals. It is demonstrated that magnetic hard disk drive could be operated without tribological failures under the height of laser bumps.

• 대한두경부종양학회:학술대회논문집
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• 2003.11a
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• pp.221-221
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• 2003

• Proceedings of the Optical Society of Korea Conference
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• 1989.02a
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• pp.36-38
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• 1989

We have developed Magnetic Pulse Compression System to realize repetitive excimer laser excitation. The principle of this system is to use the large change in permiability owing to the nolinear characteristics of ferro-magnetic material (Metglas2605s-2 metal ribon). Prior to the laser operation, the MPC system was tested with a dummy load (5$\Omega$) and laser head. Laser head has a discharge volume of 1.0 (w) x 2.0 (h) x 20.0(1) cm. This MPC system compressed a 6.2us (FWHM), 80 A pulse into a 0.4us(FWHM), 1.3kA pulse.

• Medical Lasers
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• v.9 no.1
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• pp.79-83
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• 2020

This paper reports a case of type 1 posterior glottic stenosis in a 60-year-old woman that was misdiagnosed as bronchial asthma. The patient was intubated at another hospital after ingesting herbicide and extubated seven days later. Although her voice changed, she had not received treatment at that time. She visited a local internal medicine clinic when her condition deteriorated to the point of dyspnea, but several months of treatment for bronchial asthma failed to improve her symptoms. Upon admission to the author's hospital, a laryngoscopic examination revealed a type 1 posterior glottic stenosis, which was removed surgically using a CO₂ laser.

• Korean Journal of Head & Neck Oncology
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• v.25 no.1
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• pp.18-23
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• 2009

Objectives : In $CO_2$ laser surgery for supraglottic cancer, neck dissection is generally done in second stage. We investigated simultaneous neck dissection with primary resection could be available in laser supraglottic surgery. Material and Methods : We analyzed 13 patients with supraglottic cancer who were treated with transoral supraglottic laryngectomy and simultaneous neck dissection from 2001 to 2007. Tumor stage, extent of laser surgery, histological results, survival rate, local control rate, complications, and functional results were reviewed. Results : 5-year local control rate, survival rate and disease specific survival rate from the neck was 100%, 69.9%, 100% respectively. Tracheotomy was done in all 13 cases. One patient had a long tracheotomy indwelling (191 days). In the rest of 12 patients average decanulation time was 7.4 days(1-22 days). Nasogastric tube was inserted in 5 cases, and average oral intake was possible in 3.5 days(1-16 days). Average hospital days was 29.7 days. There was no serious complication associated with neck dissection. Conclusion : Simultaneous neck dissection with primary laser resection for supraglottic cancer is oncologic sound and can be performed without significant surgical morbidity.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.30 no.1
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• pp.53-56
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• 2019

The optimal treatments of carcinoma in situ of glottis include radiotherapy, laser surgery and vertical partial laryngectomy. Conventional surgical treatments need general anesthesia and radiotherapy has several complications. Recently, the effectiveness of 532 nm potassium titanyl phosphate (KTP) laser has been proven and widely used in vocal fold diseases even some cases of vocal fold dysplasia. A patient with difficult laryngeal exposure underwent fiberoptic laryngeal laser surgery using KTP laser under local anesthesia, showed improved voice outcome and the glottic lesion was removed successfully without local recurrence and regional metastasis 18 months after surgery.

• Korean Journal of Head & Neck Oncology
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• v.31 no.2
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• pp.74-77
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• 2015

A lingual thyroglossal duct cyst(LTGDC) is a rare congenital anomaly that account for only 0.5% to 2% of total thyroglossal duct cyst. LTGDC is frequently associated with respiratory problem in infants and pharyngeal foreign body sensation or dysphagia in adults. Because of its location and characteristics, lingual thyroid, dermoid cyst, and vallecular cyst should be included in differential diagnosis. Standard treatment for thyroglossal duct cyst is sistrunk's operation, but in terms of LTGDC, because of its location and cosmetic reasons, different kinds of treatments such as electrical cauterization, $CO_2$ laser, Robort surgery via transoral approach have been introduced. Recently authors encountered 21 years old woman with LTGDC and the mass was removed successfully via transoral approach using $CO_2$ laser. We report the clinical course with review of the literature.

• Korean Journal of Head & Neck Oncology
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• v.23 no.1
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• pp.58-62
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• 2007

Schwannoma is a benign well-encapsulated tumors arising from the sheath of Schwann cell of the peripheral motors, sensory, and cranial nerves, but not from the optic and olfactory nerves. Since it is relatively common in the head and neck region, it should be included in the differential diagnosis of head and neck tumor. However, reports of laryngeal involvement have rarely appeared in the literature. We have experienced a 50-year old woman and 39-year old woman with history of progressive voice change. We recognized a benign mass at the false cord area with the telelaryngoscope and CT. The tumors were successfully removed by transoral CO2 laser resection without tracheotomy.

• Medical Lasers
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• v.10 no.3
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• pp.170-175
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• 2021

Background and Objectives Cisplatin is an important chemotherapy drug for the treatment of head and neck cancer. Interstitial laser treatment (ILT) has cosmetic utility and is very important for maintaining the function of the head and neck after cancer treatment. This study examined the synergistic effects of locally injected cisplatin-epigel and high fever induced by an interstitial potassium titanyl phosphate (KTP) laser treatment on a xenografted human Heinz squamous cell carcinoma. Materials and Methods SNU-1041 (107 cells/0.1 ml) cells were xenografted into the back of nude mice by subcutaneous injection. The ILT group (n = 10) was treated with a KTP laser (1 J/mm³) through a cylindrical diffuser tip inserted into the tumor, monitoring the temperature at 43-45℃. In the combined treatment group (n = 10), local hyperthermia was induced by intratumoral injection of 100-200 ㎍ of cisplatin into a collagen-based gel carrier (cisplatin-epigel), which was released slowly four hours before ILT. After four weeks of follow-up, the treated tumors were evaluated for tumor remission and volume change. Results Eight (80%) of the combined group showed complete tumor remission at the four-week follow-up, whereas only three (30%) of the ILT group showed remission (30%) (p < 0.01). Conclusion The current study has shown the synergistic effects of a local cisplatin injection and high fever from ILT on a xenografted human Heinz squamous cell carcinoma.