• Journal of the Korean Vacuum Society
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• v.13 no.2
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• pp.86-91
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• 2004

Transiton-metal gallides attract wide interest as a candidate for high-temperature structural materials. In a wide composition range, in which it was known that Co-Ga alloy have CsCl (B2) crystallographic structure, a systematic study on the correlation between physical properties and electronic structures of Co-gallides was performed. $Co_{l-x}Ga$ $_{x}$ alloys ($0.35\leq$x$\leq0.55$) were prepared by arc-melting method and were annealed at $1000 ^{\circ}C$ for 48hour to increase the homogeneity. In this composition range all the prepared alloys have the CsCl (B2) structure. The chemical states and the electronic structure were studied by using x-ray photoemission spectroscopy (XPS), and x-ray absorption near-edge structure (XANES), and exhibit different physical properties depending on the composition. During the annealing, a significant oxidation has happened and all the oxygen atoms are incorporated with the Ga atoms to form a $Ga_2O_3$ phase. In a view point of electronic structure, the $Co_{l-x}Ga$ $_{x}$ alloys were formed by the Ga(p) - Co(d) hybridization.

• Korean Journal of Radiology
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• v.1 no.2
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• pp.65-72
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• 2000

Objective: To compare the efficacy of suprapapillary and transpapillary methods of transhepatic biliary metallic stent placement in malignant biliary strictures and to specify the indications of each method applied. Materials and Methods: Stents were placed in 59 patients. Strictures were categorized as type A (within 3 cm of the ampulla, n = 27), type B (over 3 cm from ampulla, n = 7), type C (within 3 cm of the bending portion, n = 9), or type D (over 3 cm above the bending portion, n=16). The stenting method was suprapapillary in 34 cases and transpapillary in 25. The rates of initial and long-term patency and of early recurrence were compared. Results: Initial patency rates for the suprapapillary and transpapillary methods were 1/7 (14.3%) and 20/20 (100%) respectively for type A (p < 0.0001), 4/5 (80.0%) and 2/2 for type B, 3/7 (42.9%) and 2/2 for type C, and 15/16 (93.8%) and 0/0 for type D. Early recurrence rates were 7/30 (23.3%) using the suprapapillary method and 4/29 (13.8%) using the transpapillary method (p = 0.51). The long-term patency rate did not differ significantly according to either type (p = 0.37) or method (p = 0.62). Conclusion: For good initial patency, the transpapillary method is recommended for strictures of the distal extrahepatic duct near the ampulla and just above the bending portion. Long-term patency is not influenced by the stenting method employed.

• Biotechnology and Bioprocess Engineering:BBE
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• v.3 no.2
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• pp.71-77
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• 1998

The strain of Serratia marcescens QM B1466 produces selectively large amount of chitinolytic enzymes (about 1mg/L medium). Enzymatic hydrolysis of chitin to N-acetyl-${\beta}$-D-glucosamine (NAG) was performed with a system consisting of two hydrolases (chitinase and chitobiase) produced by optimization of a microbial host consuming chitin particles. For the development of Large-scale biological process for the production of NAG from chitinaceous waste, the selection and optimization of a microbial host, particle size of crab/shrimp chitin sources and initial induction time using chitin as a sole carbon source on chitinase/chitobiase production and NAG production were examined. Crab-shell chitin(1.5%) treated by dilute acid and , ball-milled with a normal diameter less than 250m gave the highest chitinase activity over a 7 days culture. Crude chitinase/ chitobiase solution obtained in a 10 L fed-batch fermentation showed a maximum activities of 23.6 U/mL and 5.1 U/mL, respectively with a feeding time of 3 hrs, near pH 8.5 at 30$^{\circ}C$.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.14 no.4
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• pp.265-273
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• 2002

In this paper, wave absorbing characteristics of a horizontal submerged punching plate are investigated throughout the calculation and the experiment. The punching plate with the array of circular holes can force the flow to separate and to form eddies of high vorticity and cause significant energy loss. As an analytic tool, the linear water wave theory and the eigenfunction expansion method is applied. Darcy's law that the normal velocity of the fluid passing through the punching plate is linearly proportional to the pressure difference between two sides of the punching plate is assumed. The proportional constant called the porous coefficient is deeply dependent to the porosity. To obtain the relationship between the porosity and the porous coefficient the systematic model test for the punching plates with 6 different porosities is conducted at 2-dimensional wave tank. It is found that the porous coefficient is linearly proportional to the porosity(b=57.63P-0.9717). It is also noted that the optimal porosity value is near P=0.1 and the optimal range of submergence depth is $d/h\\leq0.2$ within entire frequency range.

• Journal of muscle and joint health
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• v.20 no.3
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• pp.214-224
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• 2013

Purpose: The purpose of this study was to identify the differences in preference for terminal care between hospitalized patients and nurses. Methods: A cross-sectional descriptive design was used in 79 patients and 107 nurses. The data were collected from August to October 2011, using the Preference for Care near the End of life Scale - Korean Version (PCEOL-K) with 5-point scale of 26 items. The reliability of the tool was Cronbach's ${\alpha}=.74$. Results: The mean score (SD) of PCEOL-K's sub-dimensions in nurses' priority was: (a) pain $3.70{\pm}0.63$, (b) spirituality $3.63{\pm}0.61$, (c) family $3.40{\pm}0.70$, (d) autonomous decision making $2.30{\pm}0.66$, and (e) decision making by healthcare professionals $2.14{\pm}0.64$. In patients' priority, the $M{\pm}SD$ score of each sub-dimension was: (a) pain $3.86{\pm}0.65$, (b) family $3.83{\pm}0.57$, (c) decision making by healthcare professionals $3.37{\pm}0.85$, (d) spirituality $3.01{\pm}0.80$, and (e) autonomous decision making $2.43{\pm}0.63$. Results indicated significant differences between nurses and patients regarding decision making by healthcare professionals (t=-11.28, p<.001), family (t=-4.66, p<.001), and spirituality (t=5.71, p<.001). Conclusion: The PCEOL-K of patients was higher than nurses'. A terminal care program for hospitalized patients at the end of life should be planned according to the results of PCEOL-K in nurses and patients.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.5 s.108
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• pp.461-475
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• 2006

In this paper, it is described about the tri-band mobile antenna system design to provide broadband multimedia and direct broadcasting services using goo-stationary Koreasat 3, simultaneously operated in Ka/K/Ku band. The radiating part of the antenna system with a fan beam characteristic in the elevation plane is composed of the quasi-offset dual shaped reflector and the tri-band feeder. The tri-band feeder is also composed of the Ka/K dual band feeder with the protruding dielectric rod, the circular polarizer, the ortho-mode transducer and the circular-polarized Ku band feed array. Especially, the Ka/K dual band circular polarizer was realized firstly using the comb-type structure. For fast satellite-tracking on the movement, the Ku band feed array has the structure of the $2{\times}2$ active phased array which can make electrical beams. And, the circular-polarized characteristic in the feed array was improved by $90^{\circ}$ rotating arrangement of four radiating elements polarized circularly by a $90^{\circ}$ hybrid coupler, respectively. Four beam forming channels to make electrical beams at Ku band are divided into the main beam channel and the tracking beam channel in the output, and noise temperature characteristics of each channel were analyzed on the basis of the contributions of internal sub_units. From the fabricated antenna system, the output power at $P_{1dBc}$ of Ka_Tx channel was measured more than 34.1 dBm and the measured noise figures of K/Ku_Rx channels were less than 2.4 dB and 1.5 dB, respectively, over the operating band. The radiation patterns with co- and cross-polarization in the tri-band were measured using a near-field measurement in the anechoic chamber. Especially, Ku radiation patterns were measured after correcting each initial phase of active channels with partial radiation patterns obtained from the independent excitation of each channel. The antenna gains measured in Ka/K/Ku band of the antenna system were more than 39.6 dBi, 37.5 dBi, 29.6 dBi, respectively. And, the antenna system showed good system performances such as Ka_Tx EIRP more than 43.7 dBW and K/Ku_Rx G/T more than 13.2 dB/K and 7.12 dB/K, respectively.

• Journal of the Korean Magnetics Society
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• v.20 no.5
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• pp.173-177
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• 2010

The electronic structure of charge-density-wave (CDW) system $CeTe_2$ has been investigated by using angle-resolved photoemission spectroscopy (ARPES). The clearly dispersive band structures are observed in the measured ARPES spectra, indicating the good quality of the single-crystalline sample employed in this study. The four-fold symmetric patterns are observed in the constant energy (CE) mappings, indicating the $2{\times}2$ lattice deformation in the Te(1) sheets. The observed CE images are similar to those of $LaTe_2$, suggesting that Ce 4f states have the minor contribution to the CDW formation in $CeTe_2$. This study reveals that the carriers near the Fermi level should have mainly the Te(1) 5p and Ce 5d character, that the Te(1) 5p bands contribute to the CDW formation, and that the Ce 5d bands cross the Fermi level even in the CDW state.

• Development and Reproduction
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• v.10 no.2
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• pp.85-92
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• 2006

Progesterone(P4) is an important intermediate in the synthesis of androgens and estrogens. Furthermore, P4 itself plays a crucial role in ovulation, atresia and luteinization, and is essential for the continuation of early pregnancy in all mammalian species. In spite of the hormone's physiological importance, the exact action mechanism(s) of P4 in mammalian ovary has not been fully understood yet. In this context, a decades-long controversy regarding the identity of receptors that mediate non-genomic, transcription-independent cellular responses to P4 is presently attracting huge scientific interests. P4 may exert its action in mammalian ovary by several ways: 1) the well-documented genomic pathway, involving hormone binding to so-called classic cytosolic receptor(PGR) and subsequent modulation of gene expression by the ligand-receptor complex as transcription factor. 2) pathways are operating that do not act on the genome, therefore refered to as non-genomic actions. The prominent characteristics of the non-genomic P4 actions are: (i) rapid, (ii) insensitive to transcription inhibitors, (iii) transduced by membrane associated molecules. In particular, the non-genomic P4 actions could be mediated by: (a) classic genomic P4 receptor(PGR) that localizes at or near the plasma membrane, (b) a family of membrane progestin receptors(MPR $\alpha$, MPR $\beta$ and MPR $\gamma$), (c) progesterone receptor membrane component I(PGRMC1), and (d) a membrane complex composed of serpine I mRNA binding protein(SERBP1). The present review summarized these rapid signaling pathways of P4 in the mammalian ovary.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.7
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• pp.1373-1380
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• 1992

The local cyclic strain distribution near the crack tip has been investigated by the fine Dot Grid Strain Measurement Method, which had been suggested strain measurement method to resolve experimental difficulties by authors. It has been found that the magnitude of the local cyclic strain distribution(.DELTA..epsilon.$_{eq}$ )near a crack tip has been varied by the applied cyclic load level and material, but the shape of the local cyclic strain distribution near the crack tip has been experimentally scrarcely altered : that is .DELTA..epsilon.$_{eq}$ = .DELTA.A.f(.theta.). $r^{-1}$ . Consequently, the local cyclic strain field near the crack tip could be favorably characterized by a single parameter fatigue strain intensity factor .DELTA.A. In addition, with the viewpoint that .DELTA.A depends on material and load level, .DELTA.A has been applied to evaluate the fatigue crack propagation rate and usefulness of the result has been considered. As a result, it has been ascertained that .DELTA.A has been a useful parameter to evaluate the fatigue crack propagation rate.

• Korean Journal of Environmental Agriculture
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• v.21 no.3
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• pp.178-188
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• 2002

Constructed wetlands typically cost less to build and operate, and require less energy than standard mechanical treatment technology but they have similar performance to centralized wastewater treatment plants. Therefore, they were constructed especially many in rural areas, where are small villages but not industries. Plantless column tests were performed to investigate the possibility on using zeolite as a filter medium of constructed wetland for the wastewater treatment. Removal efficiency was $COD_{Cr}$ 94.63% T-P 41.41% and $NH_4^+-N$ 99.75% at hydraulic load 314 $L/m^2{\cdot}d$ and filtering height 100 cm filled with a zeolite mixture. This zeolite mixture consisted of 1 : 1 by volume of zeolites in the diameter range of 0.5 to 1 mm and 1 to 3 mm. Accordingly, hydraulic load 314 $L/m^2{\cdot}d$ was considered as optimal. Three zeolite mixtures were used to determine the optimal mixing ratio by volume of a zeolite (A) in the diameter range of 0.5 to 1 mm to a zeolite (B) in the diameter range of 1 to 3 mm 1 : 3, 1 : 1 and only B in A to B by volume were tested at hydraulic load 314 $L/m^2{\cdot}d$ and filtering height 100 cm $COD_{Cr}$ removal efficiency was more than 89% at mixing ratios of 1 : 3 and 1 : 1 in A to B. That of T-P ranged 56.42 to 58.72% and, that of T-N and $NH_4^+-N$ was 87% and 99% regardless of mixing ratios of two zeolites. Removal efficiency was lower at the column filled with only B. Removal efficiency was better at Inter medium filled with mixing ratio 1 : 1 in A to B than with the other mixing ratios. Thus, it was found that the mixture of mixing ratio 1 : 1 in A to B was appropriate far Inter medium of constructed wetland Removal efficiency was higher in down-flow than in up-flow, and all contaminants were removed most in 20 cm filter height near feeding area.