• Journal of Korean Ophthalmic Optics Society
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• v.16 no.1
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• pp.31-40
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• 2011

Purpose: This study was performed to investigate the actual state about ultrasonic cleaning of soft contact lenses in local optical shops and evaluate the removal effect of protein deposit on soft contact lenses with different lens containers by ultrasonic cleaner for eyeglasses. Methods: The actual state about ultrasonic cleaning of soft contact lenses was surveyed in total 75 local optical shops in Seoul, Korea. The cleaning efficacy of different lens containers was compared by measuring the protein remained on ocufilcon D contact lenses after washing by an ultrasonic cleaner for eyeglasses. The changes on surfaces and wetting angles of ocufilcon D contact lenses by repeat ultrasonication were further investigated. Results: The main purpose to use ultrasonic cleaners in local optical shops was rapid cleaning. The ultrasonic cleaning efficacy of ocufilcon D contact lenses with glass containers was little higher than it with plastic containers, but was not significantly different. The changes on surfaces and wetting angles of ocufilcon D contact lenses in a plastic lens container by repeat ultrasonication such as 30 and/or 60 times were shown. Conclusions: There was not significant difference in cleaning efficacy between glass and plastic lens containers. However, repeat cleaning with ultrasonic cleaner for eyeglasses would be carefully considered since some significant changes in the parameters of lens surface and wetting angles were detected by repeat ultrasonification even when lens containers were used for ocufilcon D contact lens during ultrasonictions.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.3
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• pp.341-349
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• 2017

Blood decontamination is an important factor in success of the orthodontic bracket. The purpose of this study is to evaluate the shear bond strength affected by blood decontamination. The shear bond strength was measured on blood decontamination before and after primer photopolymerization. And the adhesive remnants type and surface patterns was evaluated under scanning electron microscopy. A total of 50 human premolars were prepared. Group I was attached using conventional resin-acid etching method as control group. Group II and III were blood contaminated before curing primer and groups IV and V were blood contaminated after curing primer. Group II and IV were treated only with cotton pellet and Groups III and V were treated with cotton pellet after water washing. The mean shear bond strengths were in the order of groups I, V, III, II, and IV. In scanning electron micrographs group III and V showed more uniform surface than group II and IV. The ARI was significantly different between the control group and the experimental groups (p <0.05).

• Asian Journal of Atmospheric Environment
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• v.6 no.4
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• pp.268-274
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• 2012

To perform quick measurements of black carbon (BC) particles deposited on foliar surfaces of forest tree species, we investigated an optical method for measuring the amount of BC extracted from foliar surfaces and collected on quartz fiber filters. The seedlings of Fagus crenata, Castanopsis sieboldii, Larix kaempferi and Cryptomeria japonica were exposed to submicron BC particles for one growing season (1 June to 7 December 2009). At the end of the growing season, the leaves or needles of the seedlings were harvested and washed with deionized water followed by washing with chloroform to extract the BC particles deposited on the foliar surfaces. The extracted BC particles were collected on a quartz fiber filter. The absorption spectrum of the filters was measured by spectrophotometer with an integrating sphere. To obtain the relationship between the absorbance of the filter and the amount of BC particles on the filter, the amount of BC particles on the filter was determined as that of elemental carbon (EC) measured by a thermal optical method. At wavelengths below 450 nm, the absorption spectrum of the filter showed absorption by biological substances, such as epicuticular wax, resulting in the low coefficient of determination ($R^2$) in the relationship between the amount of EC on the filter ($M_{EC}$, ${\mu}g\;C\;cm^{-2}$ filter area) and the absorbance of the filter. The intercept of the regression line between $M_{EC}$ and the absorbance of the filter at 580 nm ($A_{580}$) was closest to 0. There was a significant linear relationship between the $A_{580}$ and $M_{EC}$ ($R^2$=0.917, p<0.001), suggesting that the amount of BC particles collected on the filter can be predicted from the absorbance. This optical method might serve as a simple, fast and cost-effective technique for measuring the amount of BC on foliar surfaces.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.348-348
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• 2011

Carbon nanotube (CNT) field effect transistors and sensors use CNT as a current channel, of which the resistance varies with the gate voltage or upon molecule adsorption. Since the performance of CNT devices depends very much on the CNT/metal contact resistance, the CNT/electrode contact must be stable and the contact resistance must be small. Depending on the geometry of CNT/electrode contact, it can be categorized into the end-contact, embedded-contact (top-contact), and side-contact (bottom-contact). Because of difficulties in the sample preparation, the end-contact CNT device is seldom practiced. The embedded-contact in which CNT is embedded inside the electrode is desirable due to its rigidness and the low contact resistance. Fabrication of this structure is complicated, however, because each CNT has to be located under a high-resolution microscope and then the electrode is patterned by electron beam lithography. The side-contact is done by depositing CNT electrophoretically or by precipitating on the patterned electrode. Although this contact is fragile and the contact resistance is relatively high, the side-contact by far has been widely practiced because of its simple fabrication process. Here we introduce a simple method to embed CNT inside the electrode while taking advantage of the bottom-contact process. The idea is to utilize a eutectic material as an electrode, which melts at low temperature so that CNT is not damaged while annealing to melt the electrode to embed CNT. The lowering of CNT/Au contact resistance upon annealing at mild temperature has been reported, but the electrode in these studies did not melt and CNT laid on the surface of electrode even after annealing. In our experiment, we used a eutectic Au/Al film that melts at 250$^{\circ}C$. After depositing CNT on the electrode made of an Au/Al thin film, we annealed the sample at 250$^{\circ}C$ in air to induce eutectic melting. As a result, Au-Al alloy grains formed, under which the CNT was embedded to produce a rigid and low resistance contact. The embedded CNT contact was as strong as to tolerate the ultrasonic agitation for 90 s and the current-voltage measurement indicated that the contact resistance was lowered by a factor of 4. By performing standard fabrication process on this CNT-deposited substrate to add another pair of electrodes bridged by CNT in perpendicular direction, we could fabricate a CNT cross junction. Finally, we could conclude that the eutectic alloy electrode is valid for CNT sensors by examine the detection of Au ion which is spontaneously reduced to CNT surface. The device sustatined strong washing process and maintained its detection ability.

• Parasites, Hosts and Diseases
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• v.23 no.2
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• pp.269-284
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• 1985

The metabolism of Entamoeba histolytica would be affected by various environmental factors, and alteration of the environment was known to afEect the fine structure of 5. histolytica. The present study was designed electronmicroscopically to investigate the ultrastructure and enzyme activities in the aEonic and conventional strains of 5. histolytica. The trophozoites of axenically cultivated HK-9 strain and conventional YS-27 and YS-49 strains of 5. histolytica were collected and liKed with 4% paraformaldehyde/0.1M cacodylate buffier(pH 74), After washing them by centrifugation, 1% warm agar was added in the sediment. Solidified agar with the trophozoites was cut into $lmm^3$ cubes, and incubated in the various substrates to observe enzyme activities. Then, the specimen was post-fixed with 3% glutaraldehyde/0.1M cacodylate buffer (PH 7.4) and 1% osmium tetroBide/0.1M cacodylate buffier (pH 7.4) , dehydrated in ascending ethanol series and embedded in epoxy resin. These were sectioned on an ultramicrotome and observed with a transmission electronmicroscope. The procedures for the observation of the fine structure were same as the above, except for the incubation in the substrate. The sections were stained with uranyl acetate and lead citrate. For the observation of the surface of the amoebae, scanning-electronmicroscopy was carried out. The results obtained in the present study are summarized as follows: 1. The fuzzy coat around double-layered plasma membrane of 5. histolytica was more irregularly and densely distributed in the conventional strains (YS-27, YS-49 strains) than in the axonic strain (HK-9 strain). 2. The endosomes, button bodies and chromatin material were surrounded by a double-layered nuclear membrane having scattered nuclear fores. The paranuclear body, mono- or double-layered vacuoles, vacuolar membrane whorls, rosette-like cylindrical bodies, aggregation of cylindrical bodies and helical bodies were found in the cytoplasm of the amoebae. Helical bodies and glycogen granules were generally abundant, while a few smooth endoplasmic reticula were observed in the cytoplasm. 3. Alkaline phosphatase activity was mainly demonstrated in the plasma membrane, limiting membranes of vacuoles and smooth endoplasmic reticula. ATPase activity was observed in the nucleus, limiting membranes of vacuoles and vacuolar membrane whorls. 4. Acid phosphatase activity was commonly demonstrated in the limiting membranes an contents of vacuoles, Iysosome-like organelles, plasma membrane and the button bodies in the nucleus. The activity was more weakly demonstrated in the HK-9 strain than in the other conventional strains of 5. histolytica. No peroBidase activity was observed in the amoeba strains employed in the present study. 5. With a scanning electron-microscope, no distinct structural differences were observed between the amoeba strains. All the trophozoite forms of the amoebae showed crater-like depressions and rugged features on the outer surface.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.2
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• pp.79-85
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• 2018

A two-way pump can reduce costs by draining and circulating water out and into the drum of the washing machine using a single motor whereas a conventional one-way pump uses two motors for doing the same function. However, when the water is drained through the drainage outlet in the two-way pump casing, a backward or inhalation flow occurs and the water flows to the circulation outlet. Likewise, when the water is circulated, the backward flow or inhalation makes the water flow to the drainage outlet. In this study, design optimization of the two-way pump casing is performed to maximize its performance while improving backward flow and inhalation occurring inside of the pump casing. For this, design variables of the pump casing that mainly affect the performance of the pump such as flow rate and torque of the motor were selected through the analysis of mean. Using response surface models for the performances, the ratio of the flow rate to the torque was maximized with satisfying the constraints for the back flow and inhalation through design optimization.

• Journal of Korean Society on Water Environment
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• v.31 no.5
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• pp.523-532
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• 2015

Hydrocyclone is widely used in industry, for its simple design, high capacity, low maintenance and low operational cost. The objective of this study is to develop hydrocyclone coagulation and filtration system. The system is made of hydrocyclone ballasted coagulation with polyaluminium chloride silicate (PACS) and upflow filter to treat micro particles in urban storm runoff. Roadside sediment particles (< $200{\mu}m$) was mixed with tap water to make various turbid suspensions to simulate urban storm runoff. The filter cartridge was filled with polyethylene media system and ran 1hr per everyday and total operation time were 8.19hrs and backwashing everyday after end of operation. The operation condition of flowrate was $8.2{\sim}11.9m^3/day$ (mean $10.1m^3/day$) and surface overflow rate (SOR) based on filter surface area was $45.5{\sim}65.9m^3/m^2/day$ (mean $55.7m^3/m^2/day$). The range of PACS dosage concentration was 14.0~31.5 mg/L. As the results of operation, the range of removal efficiency of turbidity, SS were 81.0~95.8% (mean 89.5%) 81.8~99.0% (mean 91.4%), respectively. An increase of filtration basin retention time brought on increased of removal efficiency of turbidity and SS, and increase of SOR brought on decreased of removal efficiency. During the first flush in urban area, storm runoff have an high concentration of SS (200~600 mg/L) and the filtration bed becomes clogged and decreased of removal efficiency. Backwashing begins when the drainage pipe valve at the filtration tank bottom is completely open (backwashing stage 1). Backwashing stage 2 was using air bubbles and water jet washing the media for 5 mins and open the drainage valve. After backwashing stage 1, 2, 61.83~64.04%, 18.53~27.51% of SS loading was discharged from filtration tank, respectively. Discharged SS loading from effluent was 7.12~14.79% and the range of residual SS loading in fliter was 2.26~5.00%. The backwashing effects for turbidity, SS were 89.5%, 91.4%, respectively. The hydrocyclone coagulation and filtration with backwashing system, which came out to solve the problems of the costly exchange filter media, and low efficiency of removing micro particles of filter type nonpoint treatment devices, is considered as an alternative system.

• 한국문화재보존과학회:학술대회논문집
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• 2004.10a
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• pp.15-24
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• 2004

The Seokgatap pagoda composed of mainly alkali granite and other minor pink-feldspar granite, fine-grained granite, granodiorite, diorite, gabbro, and tuff. Despite the small loss and damage derived from joints, its peel-off and exfoliation are serious enough to cause the heavy deterioration on the stone surface. The chemical and petrological weathering has partly replaced the original rock-forming minerals with clay minerals and iron oxyhydroxides. Based on the petrogenesis, rock materials of the pagoda is very similar to rocks of Dabotap pagoda and the Namsan granite in the Gyeongju. The central fart of the pagoda has sunken highly, which caused all the corners to split and the structural transformation to become worse. The reverse V-shaped gaps between the materials have broken stones filled in a coarse way. The iron plates inserted between the upper flat stone laid on other stones and tile pagoda body in the north and east side has been exposed in the air and corroded, discoloring of the adjacent stones. The overall diagnosis of the Seokgatap pagoda is the deteriorated functions of the stone materials, which calls for a long-term monitoring and plans to reinforce the stone surfaces. But the main body including the pagoda roof stone needs washing on a regular basis, and the many different cracks should be fixed with glue by using the fillers or hardeners designed for stone cultural properties after removing the cement mortar. In case of the replacement of the stone materials with new stones, it's necessary to examine the pagoda for the center of gravity and support intensity of the materials. The structural stability of the pagoda can be attained by taking a reinforce measure in geotechnical engineering and making a drainage. The ground humidity, which has aggravated weathering and structural instability, should be resolved by setting up a humidity reduction facility. The contamination of lichens and bryophyte around the pagoda and on the surface is serious. Thus biochemical treatments should be given too in order to prevent further biological damages and remove the vegetation growing on the discontinuous planes.

• Journal of Haehwa Medicine
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• v.13 no.2
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• pp.187-196
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• 2004

Now many sustitution and false articles is used in korea instead of shanyao. To use shanyao correctly, we will make a quilitative certificational plan of shanyao to investigate all of lieraturea, records and documents. And we could reach conclusions as folloews. 1) Source About a source of shanyao, though korea and china has a each other source, we think there is no problem in use of both. 2) Process In our country producing shanyao as medical use is a 'duanma', we can divide into peeling and non-peeling, drying at bulks and at briquets, steaming shanyao and fresh shanyao. Regardless of existence for peeling and steaming, a distributing shanyao is received a proper judgment. Like this result was expressed by insufficiency of standards about medical components or indicating components. We detected a reminding S02 more than 10 ppm. And this expresses that there ia a problum at a drying method. To suggest proper processing methods, a standard of quility will have to be made which the existence of peeling, difference of quility between 'changma' and 'duanma', drying method and exudation test with cutted thickness are adaptable. Besides, 'maoshanyao' and 'guangshanyao' of china is processed by various methods which decrease a medical effect such as too much soaking shanyao in water, steaming with a sulfur, too much peeling, So we must process shanyao like the next methods. (1) When harvesting, dig deeply not to cut off roots. (2) Not to peel, wash shanyao in a washing machine. (3) Dry to 50-60% degree at sunny place or drying machine. (4) To be easy for drying and exudation, cut off a thick piece with 5 mm (5) Dry perfectly at ding machine. 3) Quality3) Quality (1) Functional standards It is not Proper that 'guangshanyao' is used in china because it has a problem with quility on process of working, If they did not soak shanyao in water or heat with steam, it is the real situation that they cannot cutt off shanyao evenly. In conclusion, shanyao must be heavy, powdery with a perfectly non-peeling surface, section surface is yellow-white color, unequal and has no holes. (2) Physicochemical standards It is the real situation that we can not distinguish into quility of shanyao with established test because various workings which decrease medical effects is used. Therefore we suggest a testing standard of S02 which is used in bleaching. And testing standards relatived with decrease of medical effects must be established at once. It must that Dry on loss is less than 14.0%, content of ash is less than 6.0%. Content of acid-nonsoluble ash is less than 0.5%. Contens of heavy metal has to detect less than 30 ppm and there is no reminding agricultural medince.

• Current Research on Agriculture and Life Sciences
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• v.31 no.3
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• pp.193-199
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• 2013

This study dyed rayon fabric using loess as a natural colorant. To obtain the optimal dyeing conditions, various dyeing conditions were examined (temperature, pH, time, and concentration). The color fastness was evaluated using standard washing and rubbing fastness tests. The results were as follows: The loess powder particle size ranged from 0.4 to $1.7{\mu}m$ with a distribution range of 1.1 to $1.4{\mu}m$, representing a fine and uniform manufactured loess powder. The loess component analysis showed a large amount of silicon dioxide and aluminum oxide. TheFT-IR spectra showed that the ammonium group in the rayon fabric produced N-H banding at $1,540cm^{-1}$. The highest K/S value for the rayon fabric was obtained when the pH was 8.0, and this value increased rapidly with a longer dyeing time and when increasing the loess concentration to 30% (w/v). Pre-treatment with a soybean solution produced the highest K/S value for the rayon fabric with a loess concentration of 30% (w/v). The SEM analysis showed a higher amount of loess adhered to the rayon fabric surface when increasing the loess concentration. However, pre-treatment with a cationic agent and soybean solution resulted in a much higher attachment of loess to the fabric surface. Thus, the experimental results showed that using a cationized fabric and pre-treatment with a soybean solution are more effective when dyeing rayon fabric with loess than when using only loess.