• Journal of the Korean Society for Heat Treatment
• /
• v.29 no.2
• /
• pp.51-55
• /
• 2016

The P/M processing of titanium aluminide using amorphous TiAl is developed by which it is possible to overcome inherent fabricability problems and to obtain a fine microstructure. A high quality amorphous TiAl powder produced by reaction ball milling shows clear glass transition far below a temperature at the onset of crystallization in differential scanning calorimetry above a heating rate of 0.05 K/s. We obtained a fully dense compact of amorphous TiAl powders, encapsulated in a vacuumed can, via viscous flow by hot isostatic pressing (HIP). Isothermally annealing of HIP'ed amorphous compact under a pressure of 196 MPa shows a progressive growth of ${\gamma}-TiAl$ phase with ${\alpha}2$ ($Ti_3Al$), which is characterized by increasing sharpness of X-ray peaks with temperature. Fully dense HIP'ed compact of titanium aluminide TiAl shows a high hardness of 505 Hv, suggesting strengthening mechanisms by sub-micron sized grain of ${\gamma}-TiAl$ and particle-dispersion by second phase constituent, ${\alpha}2$.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.6
• /
• pp.1032-1041
• /
• 2010

The comparative influence of two nanoparticles [viz., superparamagnetic iron oxide nanoparticles (SPION) and nanobarium titanate (NBT)] upon the in vitro and in situ low-density polyethylene (LDPE) biodegradation efficiency of a potential polymer-degrading microbial consortium was studied. Supplementation of 0.01% concentration (w/v) of the nanoparticles in minimal broth significantly increased the bacterial growth, along with early onset of the exponential phase. Under in vitro conditions, ${\lambda}$-max shifts were quicker with nanoparticles and Fourier transform infrared spectroscopy (FTIR) illustrated significant changes in CH/$CH_2$ vibrations, along with introduction of hydroxyl residues in the polymer backbone. Moreover, simultaneous thermogravimetric-differential thermogravimetry-differential thermal analysis (TG-DTG-DTA) reported multiple-step decomposition of LDPE degraded in the presence of nanoparticles. These findings were supported by scanning electron micrographs (SEM), which revealed greater dissolution of the film surface in the presence of nanoparticles. Furthermore, progressive degradation of the film was greatly enhanced when it was incubated under soil conditions for 3 months with the nanoparticles. The study highlights the significance of bacteria-nanoparticle interactions, which can dramatically influence key metabolic processes like biodegradation. The authors also propose the exploration of nanoparticles to influence various other microbial processes for commercial viabilities.

• Journal of Pharmacopuncture
• /
• v.11 no.2
• /
• pp.13-19
• /
• 2008

Objectives To investigate the therapeutic effects of intravenous cultivated wild ginseng(Panax ginseng C.A. Meyer) pharmacopuncture(CWGP) in treating patients with non-small cell lung cancer(NSCLC). Design Prospective case series. Setting This study was conducted at the East-West Cancer Center of Dunsan Oriental Hospital, Daejeon University. Patients Two non-small cell lung cancer patients. Intervention Two non-small cell lung cancer patients were injected CWGP(20mL/day) mixed with 0.9% normal saline(100mL) intravenously. Each patient received a total of 16 and 9 cycles, respectively. One cycle is composed of 14 days. Outcome Measures The effect of intravenous CWGP was measured by scanning with computed tomography(CT) after every 2 cycle and Positron emission tomography- computed tomography(PET/CT) after every 6 cycles. Response and progression was evaluated using the Response Evaluation Criteria in Solid Tumors(RECIST) Committee classification of complete response(CR), partial response(PR), progressive disease(PD) and stable disease(SD). Results They were treated with intravenous CWGP for 8 and 5 months respectively. time later, each tumor remains stable disease(SD). Conclusion These cases may give us a possibility that intravenous CWGP offers potential benefits for non-small cell lung cancer patients.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.11 no.2
• /
• pp.89-100
• /
• 1993

This paper is a study on the earth volume calculation using CAD and LISP(LIST Processing) in the route alignment. The utility enlargement in the industry field and the considerable progress of computer make the automatic design and manufacture for the development of CAD/CAM/CAE technique possible, and the automatic design of civil engineering works is continuously progressive. In this study we are intend to improve an effect of civil engineering work by the automatic earth volume calculation in route alignment. This paper aims to construct the automatic design system of civil engineering work and the procedures; (1) The programming of the self-scanning program of the land information introducing Digital Terrain Model concept in the map (2) Systematic algorithm construction using LISP and grafting CAD system (3) Automatic design and calculation of the mass curve and earth volume.

• Journal of Korean Neurosurgical Society
• /
• v.49 no.5
• /
• pp.296-298
• /
• 2011

Spinal intradural cysticercosis is a rare manifestation of neurocysticercosis. We report a unique patient who showed visual symptoms and normal imaging of the brain caused by isolated spinal neurocysticercosis. A 59-year-old male patient was admitted to the emergency unit with a history of severe headache and progressive blurred vision. Brain computed tomographic scanning and magnetic resonance imaging showed normal cerebral anatomy without hydrocephalus. The fundoscopic evaluation by an ophthalmologist showed bilateral papilledema. Perimetry studies revealed visual field defects in both eyes. With the diagnosis of pseudotumor cerebri, a lumbar tap was attempted; however, we could not drain the cerebrospinal fluid in spite of appropriate attempts. Lumbar magnetic resonance imaging revealed multilevel intraspinal lesions that were confirmed histologically to be neurocysticercosis. An intraoperative lumbar puncture revealed an increased opening pressure and cytochemical analysis showed elevated cerebrospinal fluid protein level. The headache resolved immediately after surgery. However, the visual symptoms remained and recovered only marginally despite antihelminthic medications after six months of operation.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.29 no.3
• /
• pp.191-199
• /
• 1993

In order to analysis creep characteristics and elastic recovery of the high-tech fibers for fishing gear materials, creep and elasticity tests were carried out on netting twines made of nylon, kevlar 29 and techmilon respectively. After creep tests, the rupture surface of raw materials was observed by scanning electron microscope(SEM). The results obtained are as follows: 1. Netting twines were arranged in order of creep rupture time as follow: techmilon, kevlar 29, nylon. The creep progressive pace was the fastest in techmilon. 2. In order of the creep elongating, netting twines were arranged as follows: nylon, techmilon, kevlar 29. 3. The rupture time T sub(r) decreased almost linearly with the increase of applied load L on the log-log scaled graph. The empirical equations computed for kevlar 29 and techmilon are as follows: T sub(r kevlar 29)=1.9512$\times$1037L super(-15.773). T sub(r techmilon)=2.7146$\times$1016L super(-6.831). 4. It was observed by SEM that creep was progressed in all netting twines. The difference of rupture morphology was recognized clearly in tensile and creep tests. 5. In order of the elastic recovery, netting twines were arranged as follows: techmilon, kevlar 29, nylon.

• Korean Journal of Microbiology
• /
• v.24 no.3
• /
• pp.197-203
• /
• 1986

Morphology and ultrastructure of protoplast fusion mode in Streptomyces lavendulae were studied by scanning and transmission electron microscopy. The isolated protoplasts were stable in some degree in hypertonic solution except that several protoplasts showed irregular morphology. Fusion events were occurred as follows; contact zone, fusion zone and separation zone were appeared sequentially. After formation of the separation zone, cytoplasm and DNA from both parents were mixed eventually. In the contact zone, two menbranes were still separated by electron transparent space. The contact zone changed to fusion zone by formation of fusion membrane that phospholipid molecules of two membranes were rearranged. Thereafter, nonmembraneous separation zone was formed by disappearance of fusion membrane. These changes were characterized by successive changes in typical membrane structure in fusion areas and by a progressive loss of bispherical shape.

• Investigative Magnetic Resonance Imaging
• /
• v.20 no.4
• /
• pp.259-263
• /
• 2016

Primary diffuse large B-cell lymphoma of the seminal vesicle is an extremely rare disorder, with only two cases reported in the English literature. Here, we present imaging findings of a case of primary diffuse large B-cell lymphoma of the seminal vesicle. On transrectal ultrasonography, the mass presented as a 3.0-cm-sized heterogeneous, hypoechoic lesion in the right seminal vesicle. Computed tomography (CT) revealed a mass with rim-like enhancement in the right seminal vesicle. On magnetic resonance imaging (MRI), the tumor showed iso-signal intensity on T1-weighted images and heterogeneously intermediate-high signal intensity on T2-weighted images. The tumor showed rim-like and progressive enhancement with non-enhancing portion on dynamic scanning. Diffusion restriction was observed in the mass. On fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET/CT) imaging, a high standardized uptake value (maxSUV, 23.5) by the tumor was noted exclusively in the right seminal vesicle.

• Tribology and Lubricants
• /
• v.37 no.5
• /
• pp.179-188
• /
• 2021

Reputed for their low friction coefficient and wear protection effect, diamond-like carbon (DLC) materials are considered amongst the most important lubricant coatings for tribological applications. In this framework, this investigation aims to elucidate the effect of a few operating parameters, such as applied stress and sliding amplitude on the friction lifetime of DLC coatings. Fretting wear tests are conducted using a 12.7 mm radius counterpart of 52100 steel balls slid against a substrate of the same material coated with a 2 ㎛ thickness DLC. Approximately, 5 to 57 N force is applied, generating a maximum Hertzian contact pressure of 430 to 662 MPa, corresponding to the applied force. The coefficient of friction (CoF) generates three regimes, first a running-in period regime, followed by a steady-state evolution regime, and finally a progressive increase of the CoF reaching the steel CoF value, as an indicator of reaching the substrate. To track the wear scenario, interrupted tests are performed with analysis combining scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), 3D profilometer and micro-Raman spectroscopy. The results show two endurance values: one characterizing the coating failure (Nc₁), and the other (Nc₂) indicating the friction failure which is situated where the CoF reaches a threshold value of μ_th = 0.3 in the third regime. The Archard energy density factor is used to determine the two endurance values (Nc₁, Nc₂). Based on this approach, a master curve is established delimitating both the coating and the friction endurances.

• Korean Journal of Culture and Social Issue
• /
• v.15 no.3
• /
• pp.359-375
• /
• 2009

This study developed a program that integrated MBSR-K and progressive muscular relaxation for the health and well-being of patients with chronic pain, and proved its effectiveness by studying 40 chronic pain patients. This program used nature of mind, body scanning meditation, breath meditation, mindfulness meditation, Hatha yoga and progressive muscular relaxation to ease chronic pain. Whenever negative feelings and emotions such as fear, anxiety, and pain occurred, the program focused on those emotions and observed the outcome. This program, which was based on the results of the preceding studies, was composed of eight courses. Major findings of the study are as follows: First, the meditation group that was composed of patients with chronic pain had significant decrease of physical symptoms compared to the control group. Second, to confirm the outstanding features of the participating patients with chronic pain that brought change in the effect of the program, characteristics of clients were analysed. Third, the program factor that influenced the effectiveness of the treatment process was evident when the training was performed twice a week rather than having once a week of training and second week for homework.