• Journal of applied mathematics & informatics
• /
• v.41 no.1
• /
• pp.155-165
• /
• 2023

We consider circular Rayleigh problem of hydrodynamic stability which deals with linear stability of axial flows of an incompressible iniviscid homogeneous fluid to axisymmetric disturbances. For this problem, we obtained two parabolic instability regions which intersect with Batchelor and Gill semi-circle under some condition. This has been illustrated with examples. Also, we derived upper bound for the amplification factor.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.17 no.2
• /
• pp.277-282
• /
• 2017

Nickel germanide (NiGe) is one of the most promising alloy materials for source/drain (S/D) of Ge MOSFETs. However, NiGe has limited thermal stability up to $450^{\circ}C$ which is a challenge for fabrication of Ge MOSFETs. In this paper, a novel method is proposed to improve the thermal stability of NiGe using Co interlayer. As a result, we found that the thermal stability of NiGe was improved from $450^{\circ}C$ to $570^{\circ}C$ by using the proposed Co interlayer. Furthermore, we found that current-voltage (I-V) characteristic was improved a little by using Co/Ni/TiN structure after post-annealing. Therefore, NiGe formed by the proposed Co interlayer that is, Co/Ni/TiN structure, is a promising technology for S/D contact of Ge MOSFETs.

• Journal of the Korean Society of Physical Medicine
• /
• v.12 no.4
• /
• pp.19-28
• /
• 2017

PURPOSE: The purpose of this study was to describe the Proprioceptive Neuromuscular Facilitation (PNF) Intervention strategy applied International Classification of Functioning, Disability and Health (ICF) Tool about strength, range of motion, scapular stability, pain and function of shoulder for patients with adhesive capsulitis. METHODS: The data was collected by patient with adhesive capsulitis. The patient was a 50-year-old male diagnosed with right shoulder with adhesive capsulitis. We applied the PNF Intervention strategy applied ICF Tool to patient with adhesive capsulitis. PNF interventions were consisting of such as combination of isotonic and stabilizing reversal technique and various positions. PNF interventions were applied, such as those aiming at decreasing pain and disability and increasing range of motion and function for the four weeks. Parameters of result were collected for strength, range of motion, scapular stability, pain and function of shoulder using the hand held dynamometer, goniometer, lateral scapula slide test, and shoulder pain and disability index, respectively. RESULTS: Clinical benefits were observed the patient with adhesive capsulitis for strength, range of motion, scapular stability, pain, and function of shoulder. The patient with adhesive capsulitis improved strength, range of motion, scapular stability, pain, and function of shoulder. CONCLUSION: Patient reported improved strength, range of motion, scapular stability, pain, and function of shoulder after intervention.

• Geomechanics and Engineering
• /
• v.19 no.2
• /
• pp.179-191
• /
• 2019

Based on the effective stress principle, a new formula for shear strength of unsaturated soil is derived under the general nonlinear Mohr-Coulomb (M-C) strength criterion to improve the classical strength criterion of unsaturated soil. Meanwhile, the simple irrigation model under steady seepage is adopted to obtain the distribution of the matrix suction or the degree of saturation (DOS) above the groundwater table in the slope. Then, combined with the improved strength criterion of unsaturated soil and the simple irrigation model under steady seepage, the limit equilibrium (LE) solutions for the unsaturated slope stability are established according to the global LE conditions of the entire sliding body with assumption of the stresses on the slip surface. Compared to the classical strength criterion of unsaturated soil, not only the cohesion soil but also the internal friction angle is affected by the matric suction or the DOS in the improved strength criterion. Moreover, the internal friction angle related to the matric suction has the nonlinear characteristics, particularly for a small of the matric suction. Thereafter, the feasibility of the present method is verified by comparison and analysis on some slope examples. Furthermore, stability charts are also drawn to quickly analyze the unsaturated slope stability.

• Journal of Ocean Engineering and Technology
• /
• v.34 no.2
• /
• pp.55-65
• /
• 2020

A review of the 2nd generation of intact stability by the International Maritime Organization is performed. The main issues with the new stability criteria are reviewed. In particular, the physical background and related mathematical formulations of the pure loss of stability and parametric roll are summarized. Based on a literature review, benchmark calculation results for 17 different types of ships are discussed, and the final results are in excellent agreement with our physical expectations. Some relatively serious design problems are found in the application of the new stability criteria to sample ships built in Korea, and possible technical solutions are proposed, which have to be improved in the coming years.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.45 no.7
• /
• pp.996-1000
• /
• 2016

Effects of copigments (succinic acid, $Cu^{2+}$, ascorbic acid, sucrose, and pH) on stability of anthocyanin extracted from black beans (Glycine max Merrill.) were investigated during storage for 8 days at 4 and $40^{\circ}C$. Succinic acid improved stability of anthocyanin by 7~15% compared to the non-treatment group at $40^{\circ}C$. $Cu^{2+}$ maintained stability of anthocyanin by about 100% for 8 days at $4^{\circ}C$. Ascorbic acid reduced stability of anthocyanin by 64~72% of non-treatment at $40^{\circ}C$. Sucrose treatment did not significantly affect stability compared to the control. The lower pH improved stability of anthocyanin. Stability at pH 1 was improved by 81~87% compared to that at pH 7. These results show that temperature, organic acid, and pH were effective in improving storage stability of anthocyanin from black beans.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.18 no.spc
• /
• pp.21-36
• /
• 2020

With respect to spent nuclear fuels, disposal containers and bentonite buffer blocks in deep geological disposal systems are the primary engineered barrier elements that are required to isolate radioactive toxicity for a long period of time and delay the leakage of radio nuclides such that they do not affect human and natural environments. Therefore, the thermal stability of the bentonite buffer and structural integrity of the disposal container are essential factors for maintaining the safety of a deep geological disposal system. The most important requirement in the design of such a system involves ensuring that the temperature of the buffer does not exceed 100℃ because of the decay heat emitted from high-level wastes loaded in the disposal container. In addition, the disposal containers should maintain structural integrity under loads, such as hydraulic pressure, at an underground depth of 500 m and swelling pressure of the bentonite buffer. In this study, we analyzed the thermal stability and structural integrity in a deep geological disposal environment of the improved deep geological disposal systems for domestic light-water and heavy-water reactor types of spent nuclear fuels, which were considered to be subject to direct disposal. The results of the thermal stability and structural integrity assessments indicated that the improved disposal systems for each type of spent nuclear fuel satisfied the temperature limit requirement (< 100℃) of the disposal system, and the disposal containers were observed to maintain their integrity with a safety ratio of 2.0 or higher in the environment of deep disposal.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.19 no.6
• /
• pp.61-66
• /
• 2020

For simple and repetitive transport tasks in limited spaces such as in factories, it is more efficient to use mobile robots instead of human workers. For this reason, the reliance on mobile robots is increasing due to the increased implementation of smart factories. Currently, the structural design of the Mecanum wheel is required to ensure the stability of the moving robot since it is used for the transport of not only small products but also large products. In this paper, to improve the stability and durability of the Mecanum wheel, ways to improve the structure of the Mecanum wheel are presented. Then, using the Castigliano theorem, the structural stability is reviewed through the deflection on existing and improved structures.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.10 no.4
• /
• pp.260-264
• /
• 2010

In this paper, Ni silicide is formed on boron cluster ($B_{18}H_{22}$) implanted source/drains for shallow junctions of nano-scale CMOSFETs and its thermal stability is improved, using vacuum annealing. Although Ni silicide on $B_{18}H_{22}$ implanted Si substrate exhibited greater sheet resistance than on the $BF_2$ implanted one, its thermal stability was greatly improved using vacuum annealing. Moreover, the boron depth profile, using vacuum post-silicidation annealing, showed a shallower junction than that using $N_2$ annealing.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.21 no.12
• /
• pp.1130-1134
• /
• 2008

Thermal and electrochemical properties were discussed with tris(2,4,6-trimethoxyphenyl)Phosphine (TTMPP) as a flame retradant additive for Li-ion battery. TTMPP showed excellent thermal stability with charged cathodes. Addition of 1 wt.% of the additive to the electrolyte improved the thermal stability without damaging the performance of the battery. The oxygne evolution reaction delayed nearly by $60^{\circ}C$. The capacity retention ratio in cycle life tests of the battery with 1 wt.% TTMPP was slightly improved comparing to the no additive cells.