• 한국세라믹학회지
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• 제53권5호
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• pp.469-477
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• 2016

The application of nanomaterials for electrodes of intermediate temperature solid oxide fuel cells (SOFC) is introduced. In conventional SOFCs, the operating temperature is higher than 1073 K, and so application of nanomaterials is not suitable because of the high degradation rate that results from sintering, aggregation, or reactions. However, by allowing a decrease of the operating temperature, nanomaterials are attracting much interest. In this review, nanocomposite films with columnar morphology, called double columnar or vertically aligned nanocomposites and prepared by pulsed laser ablation method, are introduced. For anodes, metal nano particles prepared by exsolution from perovskite lattice are also applied. By using dissolution and exsolution into and from the perovskite matrix, performed by changing $P_{O2}$ in the gas phase at each interval, recovery of the power density can be achieved by keeping the metal particle size small. Therefore, it is expected that the application of nanomaterials will become more popular in future SOFC development.

• Nuclear Medicine and Molecular Imaging
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• 제40권2호
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• pp.132-140
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• 2006

Well-differentiated thyroid cancer is the most common endocrine malignancy with an increasing incidence. Most patients with well-differentiated thyroid caner have a favorable prognosis with high survival rate. While surgery and radioiodine therapy is sufficient treatment for the majority of patients with differentiated thyroid cancer, a minority of these patients experiences progressive, life-threatening growth and metastatic spread of the disease. Because there is no prospective controlled study to evaluate the differences of management of thyroid cancer, it is hard to choose the best treatment option. And there are still lots of controversies about the management of this disease, such as surgical extent, proper use of radioiodine for remnant ablation and therapy, use of rhTSH instead of withdrawal of thyroid hormone, long-term follow-up strategy, thyroglobulin as a tumor marker, etc. In this review, recent data related to these conflicting issues and recent advances in diagnosis, radioiodine therapy and long-term monitoring of well-differentiated thyroid cancer are summarized.

• Medical Lasers
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• 제9권2호
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• pp.126-133
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• 2020

Recurrent respiratory papillomatosis (RRP) is a benign tumor that occurs in the respiratory tract, especially in the larynx. The etiology of RRP is human papillomavirus (HPV). According to the age of occurrence, RRP is divided into childhood-onset and adult-onset types. Generally, childhood-onset RRP shows a high recurrence rate and diffuse involvement in the respiratory tract. Adult-onset RRP is more localized and appears more frequently as a solitary lesion. It may be the result of sexual transmission or the proliferation of latent HPV infections. At present, the treatment of choice for RRP is CO₂ laser ablation. In addition, pulse dye laser or KTP (KTiOPO: potassium-titanyl-phosphate) lasers are also used. Non-surgical adjuvant therapies can be applied in cases requiring repetitive surgery or with diffuse extensions. This review will introduce the clinical features of RRP and various treatment options including lasers.

• Archives of Metallurgy and Materials
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• 제65권4호
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• pp.1371-1375
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• 2020

A superior SiC based thermal protection coating process for carbon composite, which can be especially effective in a hot oxidizing atmosphere, was established in this study. A multi-coating process based on a combination of Chemical Vapor Reaction (CVR) and Chemical Vapor Deposition (CVD) was developed. Various protective coating layers on carbon composite were tested in hot oxidizing surroundings and the test results verified that the thermal ablation rate could be dramatically reduced down to 3.8% when the protective multi-coating was applied. The thermal protection mechanism of the coating layers was also investigated.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.421.1-421.1
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• 2016

We studied indium-doped zinc oxide (IZO) film grown by atomic layer deposition (ALD) as transparent conductive oxide (TCO). A variety of TCO layer, such as ZnO:Al (AZO), InSnO2(ITO), Zn (O,S) etc, has been grown by various method, such as ALD, chemical vapor deposition (CVD), sputtering, laser ablation, sol-gel technique, etc. Among many deposition methods, ALD has various advantages such as uniformity of film thickness, film composition, conformality, and low temperature deposition, as compared with other techniques. In this study, we deposited indium-doped zinc oxide thin films using diethyl[bis(trimethylsilyl)amido]indium [Et2InN(TMS)2] as indium precursor, DEZn as zinc precursor and H2O as oxidant for ALD and investigated the optical and electrical properties of IZO films. As an alternative, this liquid In precursor would has several advantages in indium oxide thin-film processes by ALD, especially for low resistance indium oxide thin film and high deposition rate as compared to InCp, InCl3, TMIn precursors etc. We found out that Indium oxide films grown by Et2InN(TMS)2 and H2O precursor show ALD growth mode and ALD growth window. We also found out the different growth rate of Indium oxide as the substrate and investigated the effect of the substrate on Indium oxide growth.

• 천문학회보
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• 제39권2호
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• pp.78.1-78.1
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• 2014

An ionization front (IF) surrounding an H II region is a sharp interface through which a cold neutral gas makes transition to a warm ionized phase by absorbing UV photons from central massive stars. We investigate the structure and instability of a plane-parallel D-type IF threaded by magnetic fields parallel to the front. We find that magnetic fields increase the maximum propagation speed of the IFs, while reducing the expansion factor, defined as the density ratio of neutral to ionized phases. IFs become unstable to distortional perturbations due to gas expansion across the fronts, exactly analogous to the Darrieus-Landau instability of ablation fronts in terrestrial flames. The growth rate of the IF instability is proportional linearly to the perturbation wavenumber as well as the upstream flow speed. The IF instability is stabilized by gas compressibility and becomes completely quenched when the front is D-critical. The instability is also stabilized by magnetic pressure when the perturbations propagate in the direction perpendicular to the fields. When the perturbations propagate in the direction parallel to the fields, on the other hand, it is magnetic tension that reduces the growth rate, completely suppressing the instability when ${\beta}$ < 1.5, with ${\beta}$ denoting the square of the ratio of the sound speed to the Alfven speed in the pre-IF region. When the front experiences an acceleration, the IF instability cooperates with the Rayleigh-Taylor instability to make the front more unstable. We discuss potential effects of IF instability on the evolution and dynamics of IFs in the interstellar medium.

• 한국레이저가공학회지
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• 제13권1호
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• pp.11-15
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• 2010

Indium tin oxide (ITO) provides high electrical conductivity and transparency in the visible and near IR (infrared) wavelengths. Thus, it is widely used as a transparent electrode for the fabrication of liquid crystal displays (LCDs) and organic light emitting diode displays (OLRDs), photovoltaic devices, and other optical applications. Lasers have been used for removing coating on polymer substrate for flexible display and electronic industry. In selective removal of ITO layer, laser wavelength, pulse energy, scan speed, and the repetition rate of pulses determine conditions, which are efficient for removal of ITO coating without affecting properties of the polymer substrate. ITO coating removal with a laser is more environmentally friendly than other conventional etching methods. In this paper, pattering of ITO film from polymer substrates is described. The Yb:KGW femtosecond laser processing system with a pulse duration of 250fs, a wavelength of 1030nm and a repetition rate of 100kHz was used for removing ITO coating in air. We can remove the ITO coating using a scanner system with various pulse energies and scan speeds. We observed that the amount of debris is minimal through an optical and a confocal microscope, and femtosecond laser pulses with 1030nm wavelength are effective to remove ITO coating without the polymer substrate ablation.

• Transactions on Electrical and Electronic Materials
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• 제8권6호
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• pp.246-249
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• 2007

A triple-band antenna was developed and fabricated by LDS(Laser Direct Structuring) process. The effects of the plating rate and heat treatment condition were investigated and the gains of fabricated antennas were measured at various frequencies. The laser irradiated surface shows clearly that there are prominence and depression. It shows anchoring effect between a plating material and ablation surface. The plating rate was decreased when the plating material is exhausted in the solution. This solution needs to refreshed by the new aid solution. The copper plating thickness is decreased with the increase of heat treatment temperature in the same time but it does not change other condition. The gain of LDS antenna showed higher than the generally processed antenna. This result was related with practical use of the dimension and effective dielectric constant.

• Nuclear Engineering and Technology
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• 제56권9호
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• pp.3914-3924
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• 2024

The release source term of radioactivity becomes a critical foundation for emergency response and accident consequence assessment after a nuclear accident Rapidly and accurately inverting the source term remains an urgent scientific challenge. Today source term inversion based on meteorological data and gamma dose rate measurements is a common method. But gamma dose rate actually includes all nuclides information, and the composition of radioactive nuclides is generally uncertain. This paper introduces a novel nuclear accident source term inversion model, which is Improve Snow Ablation Optimizer-Sensitivity Analysis Pruning Extreme Learning Machine (ISAO-SAELM) model. The model inverts the release rates of 11 radioactive nuclides (I-131, Xe-133, Cs-137, Kr-88, Sr-91, Te-132, Mo-99, Ba-140, La-140, Ce-144, Sb-129). It does not require the use of the physical field of the reactor to obtain prior information and establish a dispersion model. And the robustness is validated through noise analysis test. The mean absolute errors of the release rates of 11 nuclides are 15.52 %, 15.28 %, 15.70 %, 14.99 %, 14.85 %, 15.61 %, 15.96 %, 15.42 %, 15.84 %, 15.13 %, 17.72 %, which show the significant superiority of ISAO-SAELM. ISAO-SAELM model not only achieves notable advancements in accuracy but also receives validation in terms of practicality and feasibility.

• 대한두경부종양학회지
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• 제19권1호
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• pp.41-46
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• 2003

Background and Objectives: Surgical ablation of tumors in the oral cavity and the oropharynx results in a three dimensional defect because of the needs to resect the adjacent area for the surgical margin. Although a variety of techniques are available, radial forearm free flap has been known as an effective method for this defect, which offers a thin, pliable, and relatively hairless skin and a long vascular pedicle. We report the clinical results of our 54 consecutive radial forearm free flaps used for oral cavity and oropharynx cancers. Materials and Methods: We reviewed the medical records of patients who were offered intraoral reconstruction with a radial forearm free flap after ablative surgery for oral cavity and oropharyngeal cancers from August 1994 to February 2003 and analyzed surgical methods, flap survival rate, complication, and functional results. Among these, 20 cases were examined with modified barium swallow to evaluate postoperative swallowing function and other 8 cases with articulation and resonance test for speech. We examined recovery of sensation with two-point discrimination test in 15 cases who were offered sensate flaps. Results: The primary sites were as follows : mobile tongue (18), tonsil (17), floor of mouth (4), base of tongue (2), soft palate (2), retromolar trigone (3), buccal mucosa (1), oro-hypopharynx (6), and lower lip (1). The paddles of flaps were tailored in multilobed designs from oval shape to tetralobed design and in variable size according to the defects after ablation. This procedures resulted in satisfactory flap success rate (96.3%) and showed good swallowing function and social speech. Eight of 15 cases (53.3%) who had offered sensate flap showed recovery of sensation between 1 and 6 postoperative months (average 2.6 month). Conclusion: The reconstruction with radial forearm free flap might be an excellent method for the maximal functional results after ablative surgery of oral cavity and oropharyngeal cancers that results in multidimensional defect.