• Journal of the Korean housing association
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• v.20 no.5
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• pp.31-39
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• 2009

The purpose of this study was to find out the residents' consciousness of the unit plan on condominium apartment and to contribute to develop a condominium apartment unit plan in Daejeon City. This research was performed by a questionnaire survey method, 464 data was collected from apartment residents lived in about $85\;m^2$ unit with 3 rooms and the apartments was limited to the complexes within 1-4 years of the length of building at Yuseong-gu and Seo-gu. By analyzing those data, findings are as follows: 1) Residents thought living room, kitchen and bathroom were importment space in a unit plan. They needed a storage function in an entrance and a intermediate room, and Anbang(mater bedroom) so did. 2) L-DK plan type was very popular and the type of front DK with L on the floor plan was preferred. This was unique results. 3) Sub-kitchen was needed for a refrigerator of Kimchi, the location of it was related to a main kitchen and a utility. the third room was needed for library, home office and storage space. 3) Bath-tub in An-bang and showe-booth in public bathroom was preferred. This was same to the popular trend of Korean condominium apartment. 4) The enlargment remodeling of balcony was showed livingroom balcony or personal bedrooms at the time of occupancy. They needed the balcony near a kitchen or an utility to equip a storage facility. Additionally, residents were preferred to their taste rather than a choice of interior concept package services.

• Journal of Powder Materials
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• v.24 no.1
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• pp.6-10
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• 2017

This study investigates the main growth mechanism of InP during InP/ZnS reaction of quantum dots (QDs). The size of the InP core, considering a synthesis time of 1-30 min, increased from the initial 2.56 nm to 3.97 nm. As a result of applying the proposed particle growth model, the migration mechanism, with time index 7, was found to be the main reaction. In addition, after the removal of unreacted In and P precursors from bath, further InP growth (of up to 4.19 nm (5%)), was observed when ZnS was added. The full width at half maximum (FWHM) of the synthesized InP/ZnS quantum dots was found to be relatively uniform, measuring about 59 nm. However, kinetic growth mechanism provides limited information for InP / ZnS core shell QDs, because the surface state of InP changes with reaction time. Further study is necessary, in order to clearly determine the kinetic growth mechanism of InP / ZnS core shell QDs.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.53-53
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• 2011

As the dimension of Cu interconnects has continued to reduce, its resistivity is expected to increase at the nanoscale due to increased surface and grain boundary scattering of electrons. To suppress increase of the resistivity in nanoscale interconnects, alloying Cu with other metal elements such as Al, Mn, and Ag is being considered to increase the mean free path of the drifting electrons. The formation of Al alloy with a slight amount of Cu broadly studied in the past. The study of Cu alloy including a very small Al fraction, by contrast, recently began. The formation of Cu-Al alloy is limited in wet chemical bath and was mainly conducted for fundamental studies by sputtering or evaporation system. However, these deposition methods have a limitation in production environment due to poor step coverage in nanoscale Cu metallization. In this work, gap-filling of Cu-Al alloy was conducted by cyclic MOCVD (metal organic chemical vapor deposition), followed by thermal annealing for alloying, which prevented an unwanted chemical reaction between Cu and Al precursors. To achieve filling the Cu-Al alloy into sub-100nm trench without overhang and void formation, furthermore, hydrogen plasma pretreatment of the trench pattern with Ru barrier layer was conducted in order to suppress of Cu nucleation and growth near the entrance area of the nano-scale trench by minimizing adsorption of metal precursors. As a result, superconformal gap-fill of Cu-Al alloy could be achieved successfully in the high aspect ration nanoscale trenches. Examined morphology, microstructure, chemical composition, and electrical properties of superfilled Cu-Al alloy will be discussed in detail.

• Journal of Electrochemical Science and Technology
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• v.2 no.4
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• pp.187-192
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• 2011

Photoelectrochemical performances of ZnO electrodes are enhanced by coupling with cobalt-based catalyst (CoPi) in phosphate electrolyte (pH 7). For this study, hexagonal pillar-shaped ZnO nanorods are grown on ZnO electrodes through a chemical bath deposition, onto which CoPi is deposited with different photodeposition times (10-30 min). A scanning electron microscopic study indicates that CoPi deposition does not induce any change of ZnO morphology and an energy-dispersive X-ray spectroscopic analysis shows that inorganic phosphate ions (Pi) exist on ZnO surface. Bare ZnO electrodes generate the current of ca. $0.36mA/cm^2$ at a bias potential of 0.5 V vs. SCE, whereas ZnO/CoPi (deposited for 10 min) has ca. 50%-enhanced current ($0.54mW/cm^2$) under irradiation of AM 1.5G-light ($400mW/cm^2$). The excess loading of CoPi on ZnO results in decrease of photocurrents as compared to bare ZnO likely due to limited electrolyte access to ZnO and/or CoPi-mediated recombination of photogenerated charge carriers. The primary role of CoPi is speculated to trap the photogenerated holes and thereby oxidize water into molecular oxygen via an intervalency cycle among Co(II), Co(III), and Co(IV).

• Resources Recycling
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• v.4 no.3
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• pp.26-31
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• 1995

The leaching characteristics of manganese nodules were investigated in dilute hydrochloric acid solution using copper malie as a reductant. Thc capper matte has been found to be an effective reductant for exhacting morc than 96% of Mn, 95% of Ni, 91% of Ca, 88% of Cu and 36% of Fe when leached in 2.5 M HCI at 70$^{\circ}$C for 2hr. The dissolutions of Mu, Co, and Ni depend on thc amaunt of added cappcr matte. 7he ratin of liquid and solid is an important [actor on the extraction of metals during leaching The dissolution af Mn, Co, Ni and Cu incrcascd w~th the increase in temperalure of leachant. The leaching rates of Mn, Co, NI and Cu from manganese nodule m the presznce of copper matte is limited by bath thc surface chemical reaction and pare diffusion processes. Thc activation energies far Mn. Co: Ni and Cu were 17. 61, 12.8, 17.2 and 57.88 KcaUmol, rcspcctively.

• Korean Journal of Materials Research
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• v.22 no.7
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• pp.335-341
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• 2012

Recently, the demand for the miniaturization of printed circuit boards has been increasing, as electronic devices have been sharply downsized. Conventional multi-layered PCBs are limited in terms their use with higher packaging densities. Therefore, a build-up process has been adopted as a new multi-layered PCB manufacturing process. In this process, via-holes are used to connect each conductive layer. After the connection of the interlayers created by electro copper plating, the via-holes are filled with a conductive paste. In this study, a desmear treatment, electroless plating and electroplating were carried out to investigate the optimum processing conditions for Cu via filling on a PCB. The desmear treatment involved swelling, etching, reduction, and an acid dip. A seed layer was formed on the via surface by electroless Cu plating. For Cu via filling, the electroplating of Cu from an acid sulfate bath containing typical additives such as PEG(polyethylene glycol), chloride ions, bis-(3-sodiumsulfopropyl disulfide) (SPS), and Janus Green B(JGB) was carried out. The desmear treatment clearly removes laser drilling residue and improves the surface roughness, which is necessary to ensure good adhesion of the Cu. A homogeneous and thick Cu seed layer was deposited on the samples after the desmear treatment. The 2,2'-Dipyridyl additive significantly improves the seed layer quality. SPS, PEG, and JGB additives are necessary to ensure defect-free bottom-up super filling.

• Korean Journal of Dental Materials
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• v.43 no.1
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• pp.43-50
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• 2016

The aim of this study was to investigate the effect of multiwall carbon nanotube functionalized with carboxyl group (MWCNT-COOH) on the mechanical properties of dental glassionomer cement (GIC). MWCNT-COOH was prepared by the acid oxidative method. The MWCNT-COOH was incorporated into a commercial GIC powder or liquid at 0.5 wt% or 1.0 wt%. The net setting time of the cements was measured in accordance with ISO 9917 (Dental water-based cement). Specimens for compressive strength ($4mm{\varphi}{\times}6mm$), diametral tensile strength ($6mm{\varphi}{\times}4mm$) and flexure strength with modulus ($2mm{\times}2mm{\times}25mm$) were prepared by mixing with the cement liquid and kept in water bath of $(37{\pm}1)^{\circ}C$. Mechanical tests were conducted in 1 d, 7 d, and 14 days at a cross-head speed of 1 mm/min. Compressive strength of GIC mixed with 0.5 wt% MWCNT-COOH increased significantly at 7 d. However, overall mechanical properties of GIC modified with MWCNT were not significantly increased with a delayed setting time, in comparison with control cement. Overall results indicated that the MWCNT/GIC composite cements showed a limited strengthening effect for dental glassionomer cement.

• The Korean Journal of Nuclear Medicine
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• v.7 no.2
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• pp.1-12
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• 1973

The most commonly used methods for determining thyroxine binding globulin(TBG) concentration as the total thyroxine-binding capacity utilize electrophoretic seperation of serum. Although technically simple, the electrophoretic method is time consuming and is limited in the number of samples which can be run in a single assay. The author presented a single $T_4$ load ion exchange resin method as an approach to simplify the technique as with clinical practicability and results were analyzed. For construction of the standard curves, serum mixtures were diluted with barbital buffer.which effectively blocked $T_4$-binding to TBPA. For each serum dilution, a constant amount of $T_4-^{125}I$ and increments of unlabelled $T_4$ were added. After incubation in water bath, resin beads were dispensed to the samples which binded all $T_4$ not bound to TBG. The radioactivity in the supernatant was counted in the gamma scintillation counter. Each standard curve was plotted from the percent counts in the supernatant and total $T_4$ in each tube. Unknown samples were diluted to 1:40 and ran at a single $T_4$ loading concentration, and the TBG capacity of the samples was able to be read on the standard isobars. The following results were obtained. 1) Mean and standard deviation for TBG capacity in normal population was $28.6{\pm}5.09{\mu}g\;T_4/100ml$. 2) $24.9{\pm}3.87{\mu}g\;T_4/100ml$ in hyperthyroidism showed low TBG capacity comparing to normal population.(p<0.025) 3) $31.0{\pm}2.40{\mu}g\;T_4/100ml$ in hypothyroidism showed high TBG capacity tendency comparing to normal population. 4) Reversed correlationship existed between TBG capacity and $T_3$ resin uptake(r=-0.624), TBG capacity and serum $T_4$ value (r=-0.859), and TBG capacity and free thyroxine index(r=-0.623). The author assumes that this method of assay is considerably simpler in instrumentation and technique than any other assays traditionally being used, and seems to be more practical for routine clinical laboratory use.

• Archives of Pharmacal Research
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• v.27 no.6
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• pp.646-652
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• 2004

The objective of this study was to determine the acute effect of trimetazidine (TMZ) on the pre-fatigue, fatigue and post-fatigue contractile characteristics and tension-frequency relationships of isolated rat diaphragm muscle. Muscle strips were taken from the ventral-costal aspects of the diaphragm muscle of rats killed by decapitation. The muscle strips were suspended in organ baths containing Krebs solution, with a gas mixture of 95% $O_2$ and 5% $CO_2$ at $37^{\circ}C$ and pH 7.35-7.45. After determining the thermoregulation and optimum muscle length the muscles were subjected to direct supramaximal stimulation with 0.05 Hz frequency square pulses for periods of 0.5 msec to obtain control values. After adding $5{\times}10^{-6}{\;}and{\;}5{\times}10^{-5}$ M trimetazidine solution to the respective bath media, the contractile parameters of the muscles were recorded. The contractile parameters were also recorded for both the trimetazidine and tri-metazidine-free media after application of the high frequency fatigue protocols. Later, the tension-frequency relationship was determined by applying stimulating pulses of 10, 20, 50 and 100 Hz to the muscle strips. Whilst the twitch tension obtained from the $5{\times}10^{-6}{\;}and{\;}5{\times}10^{-5}$ M trimetazidine media showed numerical increases compared to that of the controls, these were not statistically significant (p>0.05). The contraction time exhibited a dose dependent increase (p<0.001), whilst the contraction and relaxation rates did not differ significantly. The isometric contraction forces obtained with the different stimulating frequencies showed a significant increase in the tetanic contraction only at 100 Hz (p<0.05). A comparison of the pre- and post-fatigue twitch tensions in the trimetazidine media showed the post- fatigue twitch tensions to be significantly higher than those of the pre-fatigue contraction forces (p<0.05). In the $5{\times}10^{-6}{\;}and{\;}5{\times}10^{-5}$ M trimetazidine media the increases in the post-fatigue contraction force were 22 and 30%, respectively. These results demonstrated that in isolated rat diaphragm muscle, TMZ significantly limited the mechanical performance decrease during fatigue. It is our opinion that trimetazidine contributed to the observed fatigue tolerance by eliminating the factors of fatigue, due to preservation of intracellular calcium homeostasis, provision of the ATP energy levels needed by ATPase dependent pumps and especially by keeping the intracellular pH within cer-tain limits.

• The Korean Journal of Physiology
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• v.15 no.2
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• pp.91-96
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• 1981

The wormwood is one of the plants which occur widely throughout the world. Though the precise data on the entire chemical composition of mugwort leaves are not available, the major principles which have been found so far include inulin, alkaloid, thujon, sesquiterpene and several vitamins. Santonin, a parasiticide, is one of the glucosides extracted from the limited species of wormwood. It has long been known in herb medicine that the plants of this family has not only strong hemostatic, analgesic and parasiticidal actions but also therapeutic effects for diarrhea, stomachache and asthma. In recent pharmaceutical botany the wormwood is introduced to have antipyretic and astringent actions also. The mugwort(Artemisia asiatica Nakai) is the most common species of wormwood that occurs in Korea. The usage of this edible leaves of mugwort is rather various. It is used not only for wormwood bath but also as forage, moxa and medicinal agents. Recently Kim et al reported from their study on the effect of mugwort on the motility of isolated intestine of rabbits that tonus and motility were markedly enhanced by mugwort but this effect of mugwort on intestinal motility was almost completely blocked by atropine suggesting that activity of mugwort was exerted through its cholinergic effect. It was the findings of Kim et al that prompted the authors to do the present experiment. The present study was undertaken to investigate effects of mugwort(Artemisia asiatica Nakai) juice on the respiration and blood pressure in cats. And also studied was the mechanism of depressor action of Artemisia asiatica Nakai Juice (AAJ). The results obtained are as follows; 1) It was observed that mean arterial blood pressure and heart rate were decreased markedly by AAJ. Following administration of 0.15 ml/kg and 0.3 ml/kg AAJ into cats the maximum depressor responses observed were $77.5{\pm}2.2\;mmHg$ and $94.0{\pm}3.7\;mmHg$ respectively. 2) Depressor responses to AAJ were blocked markedly by atropine whereas the responses were not affected by propranolol and dibenamine. Therefore it is strongly inferred that depressor action of AAJ results mainly from its cholinergic effect. This inference was further substantiated by the fact that heart rate change which invariably accompanies depressor responses to AAJ was almost completely abolished by atropinization. 3) After administration of AAJ into cats frequency of respiration was markedly increased while depth of respiration decreased during first 2-3 seconds.