• Journal of the Korean Ceramic Society
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• v.41 no.9
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• pp.677-683
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• 2004

Nd:LLM (Nd:LiLa(MoO$_4$)$_2$) single crystals for the laser host material were grown by the Czochralski method. The Nd:LLM grown single crystals cracked easily, and the reasons of cracks are generally related with phase transition, incongruent melting, chemical heterogeneity of composition, geometric thermal structures of imbalance and growth direction. We confirmed that phase transition is not observed by TG-DTA thermal analysis, and the XRD analysis revealed congruent melting in our products. It was confirmed that the volatilization of Li$_2$O composition is the important reason of chemical heterogeneity. The geometric thermal profile of the resistance furnace of our own design was controlled with a crucible height. Also, Nd:LLM crystal affected growth direction, and was the best quality in case of (101) growth direction. The distribution and effective distribution coefficient of Nd$^{3+}$ ion were accomplished by PIXE analysis.s.

• Resources Recycling
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• v.27 no.1
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• pp.38-44
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• 2018

A large amount of Nd-Fe-B magnet scraps are generated during magnet manufacture process. In this study, selective chlorination of the rare earth elements by hydrogen chloride gas which obtained from the pyrolysis of polyvinyl chloride (PVC) was investigated. In thermogravimetric analysis, drastic weight loss was occurred at about 500 K and 710 K. At the isothermal experiments, the weight loss reaches about 30% above 673 K. XRD patterns characterized that after each experiments, ${\alpha}$-Fe, Nd oxychloride, Nd chloride, and Fe chlorides were formed, and the leaching residues remain only ${\alpha}$-Fe. The yields of Nd, Dy, and Fe for the isothermal experiment were increased with temperature and peaked at 873 K. As PVC ratio increased, the yields of Nd, Dy and Fe were also increased.

• Journal of Oral Medicine and Pain
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• v.30 no.4
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• pp.465-473
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• 2005

The purpose of this study was to evaluate the desensitizing effects of a Nd:YAG laser (Sunlase, SUNRISE Technologies, Inc., USA) irradiation on cervically exposed hypersensitive dentine. 45 patients was irradiated with pulsed Nd:YAG laser (1.5 W, 20 Hz, 75 mJ/pulse, 4 minutes) as the experimental group, 27 patients was mock irradiated as the control group. The degree of sensitivity to the thermal and tactile stimuli were determined qualitatively with an evaporative stimulus defined as two times air blast at a distance of 3 mm from each site to be tested and with a mechanical stimulus as a slightly scratching the cervical site with a dental explorer. A qualitative registration of the degree of discomfort was determined according to a numerical pain scale(NPS) in an 11-point scale in which 0= "no pain" and 10="most excruciating pain imaginable". Recordings were assessed before treatment, immediately after, 1 and 2 weeks after treatment. Pain tolerance threshold and pulp vitality were evaluated with electric pulp tester before and immediately after treatment. 1. Desensitizing of hypersensitive dentine with Nd:YAG laser irradiation was more effective than that with mock irradiation. 2. The placebo effect of mock irradiation was recognized for severe sensitive teeth($NPS\;{\geqq}\;6$), but not for moderate sensitive teeth(NPS < 6). 3. Laser irradiation did not affect the pain tolerance threshold and pulp vitality of the hypersensitive teeth. 4. Desensitizing effect of laser irradiation for the hypersensitive teeth had been continuing at least 2 weeks. It was concluded that desensitizing of hypersensitive dentine with a Nd:YAG laser is effective and the maintenance of the positive result was more prolonged than the placebo effect.

• Korean Journal of Crystallography
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• v.9 no.1
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• pp.48-52
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• 1998

The new Nd3Ba5Co4O15 phase was synthesized with Nd2O3, BaCO3, and Co3O4 by solid state reaction at 1200℃ with intermittent grinding. The crystal structure of Nd3Ba5Co4O15 has been refined on X-ray diffraction powder data by means of Rietveld method. The starting model was based on the Nd3.43Ba4.42Co2.23Al1.77O15 structure. The crystal system was hexagonal, space group P63mc(186), a=11.629(3) Å, c=6.842(2) Å. Final R values were Rwp=0.097 and Rp=0.068. The structure consists of clusters of CoVICoIV3O15 in which a CoVI octahedron shares corners with 3CoIV tetrahedra.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.29 no.1
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• pp.25-31
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• 2023

Background: In this study, the abductor hallucis activity and medial longitudinal arch angle were compared by performing four exercises, namely the short foot exercise, the short foot exercise with 2^nd~5^th toe extension, the short foot exercise with 2^nd~5^th toe extension with a load of 1kt on the sole, and the short foot exercise with 2^nd~5^th toe extension with a load of 2kg on the sole. Methods: Four short foot exercises as described above were performed by 20 healthy adult males and females. The abductor hallucis activity and medial longitudinal arch angle were measured and analyzed by surface electromyography and the Kinovea software program. Results: The short foot exercise with 2^nd~5^th toe extension, short foot exercise with 2^nd~5^th toe extension with a load of 1kg on the sole, and the short foot exercise with 2^nd~5^th toe extension with a load of 2kg on the sole showed significantly higher abductor hallucis activity than the short foot exercise alone. Among these, the short foot exercise with the 2^nd~5^th toe extension was the most effective. All exercises showed a significantly decreased medial longitudinal arch angle post-exercise than pre-exercise, and the short foot exercise with the 2^nd~5^th toe extension showed a significantly decreased medial longitudinal arch angle compared to the other three exercises. Conclusion: It is believed that the short foot exercise with the 2^nd~5^th toe extension can be proposed as an effective exercise that can replace the short foot exercise alone.

• Journal of Sericultural and Entomological Science
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• v.45 no.1
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• pp.10-17
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• 2003

This study was carried out to analyze physicochemical characteristics of sericin cocoon from silkworm, Bombyx mori. The degumming loss increased with increasing treatment time up to 2 hr, and temperature up to 130$^{\circ}C$. At 130$^{\circ}C$, degumming loss of Nd-s jam and Nd$\^$H/ jam were 100% while that of Baegok jam was 24%. Nd-s jam and Baegok jam ha high glycine content of 29.1∼46.3 mol% where as Nd$\^$H/ jam had high serine content of 32.6 mol%. Thermal denaturation temperatures were found at 218$^{\circ}C$ for Nd-s jam, 216$^{\circ}C$ for Nd$\^$H/ jam, and 218$^{\circ}C$ for Baegok jam. Before degumming, crystallinities obtained by FT-IR analysis were 44.3, 43.7, and 59.9% for Nd-s jam, Nd$\^$H/ jam, and Baegok jam respectively. After degumming, crystallinity increased to 61.8% for Baegok jam. Before degumming, crystallinitics obtained from XRD were 35.9, 33.5, and 47.2%, for Nd-s jam, Nd$\^$H/ jam, and Baegok jam. After degumming, crystallinity increased to 49.8% for Baegok jam. The molecular weight of Nd$\^$H/ jam were 9,417 in 1 hr, 3,744 in 2 hr, 4,944 in hr, and 3,910 in 6 hr.

• The Journal of Korean Academic Society of Nursing Education
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• v.6 no.1
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• pp.77-91
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• 2000

Recent changes in health problems as well as the health delivery system demand expanding nursing roles to improve quality care and at the same time provide cost-effective health services. Nursing leaders of the future will be expected to be excellent care givers who are well prepared as researchers and managers and administrators. The purpose of developing an ND program is to train nursing leaders for the future. The program objective are to demonstrate the role as 1) an advanced practitioner who will provide theory based practice 2) a researcher and manager The target population of the ND program is as follows : 1) Nurses with a BSN degree who are seeking to advance on the career ladder 2) Non-nursing BS, BA graduates who are seeking nursing as a second career 3) Transfer students who are mature and motived to be nursing leaders It is believed that the ND program would meet the diverse needs for potential students, for their role in nursing and the health delivery system and create a meaning and challenging position in the profession of nursing. A task force team was organized to develop the ND program and its activities are as follows; 1) Information on ND programs were collected from 3 universities and reviewed 2)An advanced education needs assessment was completed and it was found that 87.6% of the subjects responded positively about advanced degree work. 3) A tentative curriculum for an ND program was developed. It is a great challenge to develop a new program for nursing however, it is also our task and responsibility to further the development of nursing.

• Journal of the Korean Magnetics Society
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• v.6 no.2
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• pp.80-85
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• 1996

An externally applied magnetic field during annealing the $Nd_{2}Fe_{14}B/Fe_{3}B$ based spring magnet was found to enhance the exchange coupling between the hard and soft magnetic grains. More than 30 % increase in remanence values for melt-spun $Nd_{4}Fe_{73.5}Co_{3}(Hf_{1-x}-Ga_{x})B_{18.5}$(x=0, 0.5, 1.0) alloys was resulted from uniform distribution of $Fe_{3}B$, $\alpha$-Fe as well as $(Nd_{2}Fe_{14}B)$, and also from reduced grain size of those phases by 20 %. The result also showed that there is an optimum grain size exhibiting a high coercivity value which will be discussed in terms of previously simulated exchange coupling parameter.

• Proceedings of the Optical Society of Korea Conference
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• 1988.06a
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• pp.1-8
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• 1988

상용 가공용 Nd:YAG 레이저의 특성 및 제원 을 분석하고 설계 시 고려하여야 할 thermal lensing 효과의 영향에 따른 출력특성의 제한에 대하여 기술하였으며 이를 토대로 200W급의 Nd:YAG 레이저를 설계하였다.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.4
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• pp.532-537
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• 2003

Statement of the problem : IPS Empress ceramic has been used as one of a esthetic restorative material since it's development, but the broad application of IPS Empress ceramic to clinical prosthodontic field has been limited by its high material cost. Purpose : This study was investigated to evaluate the hardness and fracture toughness after recycling of the IPS Empress ceramic. Material and methods : Reused specimens of IPS Empress were fabricated with repeated pressing. The hardness(Vickers hardness) and fracture toughness of 1st, 2nd and 3rd pressed specimens were measured with Digital Micro Hardness Tester(Model MXT70, Matsuzawa Seiki Co., Ltd, Tokyo, Japan). The obtained data were analyzed using SPSS(Ver 9.5). Result : The mean value of the hardness in the 1st, 2nd and 3rd pressed Empress were $6.23{\pm}0.48MPa,\;5.50{\pm}0.25MPa$, and $5.70{\pm}0.42MPa$. The hardness of the 1st pressing ceramic was higher than those or the 2nd and 3rd pressed ceramics(P<0.05). Hardness of the 3rd pressed ceramic was greater than that of the 2nd pressed ceramic. but there was no significant difference of hardness between those two(P>0.05). The mean value of the fracture toughness was $1.71{\pm}0.16MPam^{1/2}$ in 1st pressed ceramic, $1.78{\pm}0.10MPam^{1/2}$ in 2nd pressed and $1.73{\pm}0.14MPam^{1/2}$ in 3rd pressed IPS ceramic. Fracture toughness of the 2nd pressed ceramic was the highest and that of the 1st pressed ceramic was the lowest. There was no significant difference of fracture toughness among them(P>0.05). Conclusion : Hardness of the 2nd and 3rd pressed IPS Empress ceramics were lesser than that of 1st pressed IPS Empress ceramic(P<0.05), but there was no significant changes of fracture toughness among them(P>0.05).