• The korean journal of orthodontics
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• v.22 no.1
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• pp.123-131
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• 1992

This study was done to evaluate the changes of enamel surface by interproximal stripping and recovery of it by polishing. The number of 34 1st premolars which had extracted for orthodontic treatment were selected as samples. Interproximal stripping was performed by hand with metal strip and strip placer (Dentaurum Co., Germany) and low speed handpiece with diamond disk (Superdiaflex, Germany). Polishing was performed by hand with plastic strip (3M Col) and low speed handpiece with whip-mix, DCPA (Dicalcium Phosphate, Anhydrous, $CaHPO_4$) powder and Sof-lex (3M Co. U.S.A.) polishing kit. Each groups were examined under the scanning electron microscope (JEOL Co., JSM-840A, Japan) and the following results were obtained: 1. The stripped group performed by metal strip and diamond disk altogether showed deep furrow on the enamel surface as wide as about $10{{\mu}m}$. 2. There could be seen more irregular scratched line in the group stripped by metal strip than that by diamond disk. 3. The polished group performed by plastic strip and DCPA powder showed slight smoothening of the edge of stripped furrow on the enamel surface without relation to the stripping method. 4. The polished group performed by Sof-lex progressive polishing kit could not avoid the formation of the furrows on the enamel surface according to the particle size without relation to the stripping method. 5. The polished group performed by the superfine polishing wheel, the final stage of Sof-lex polishing method showed shallow scratched line as wide as within about $2{{\mu}m}$ on the enamel surface without relation to the stripping method. 6. The interproximal stripped enamel surface could not recover its original surface texture by any kind of polishing methods.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.1
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• pp.94-98
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• 1982

To understand the growth pattern of ginseng plant under shading, the vertical distribution of leaf area, leaf area index (LAI) and specific leaf weight (SLW) and changes in light intensity as affected by planting position were investigated in 3 to 5 years old ginseng plant populations. Light intensity was vertically lowest at about 10cm above the ground and became low at the rear planting position in 3-year-old population. When culturing bed (96cm in width) were divided into three parts at intervals of 32cm from front to rear, the leaf area in 3-year-old population was largest in middle 1/3 part of planting bed. Light intensity affected the SLW positively, but LAI showed no distinct difference among planting positions. The light environment of 4-year-old population was worse than that of 3-year-old population and leaf area and LAI differed greatly among planting positions. In 5-year-old population, leaf dry weight and leaf area of furrow part (that is, the amount of leaves protruded from the plants which were planted in 1st, 2nd or 3rd lines into the furrow) increased. The dry weights of leaves and stem increased considerably as plant became aged, and were distributed mainly in upper layer.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.370-378
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• 2003

MFD (Make up Film Deterioration) is a gradual deterioration of applied make up and is a common problem experienced by most foundation users. Our investigation revealed that for 64% of all make up users MFD is their greatest consern is using foundations. Known that the primary cause of MFD is sebum secretion. We observed that the length of time prior to onset of MFD in people who produce high level of sebum varies significantly from person to person. This suggests that other factors besides quantity of sebum production can affect MFD. Control over this factor would, we believe, be key to developing longer-lasting makeups. We studied the relationship between MFD and skin surface conditions. Our study revealed that furrows on the skin surface affect MFD significantly. Sebum reaches the skin surface from sebaceous glands and flows along furrow on the skin. If there are many deep furrows, it takes longer for sebum to overflow. But if the furrows are few or shallow, sebum quickly overflows and spreads over the skin surface where it can degrade the make up film. Therefore even when the volume of sebum produced is the same, the rate of MFD will be different depending on the number and shape of the furrows. A longer-lasting foundation could be produced by matching personal skin condition, but this would be very difficult because individual variations in texture are very large. Therefore we approached the problem by attempting to impose sebum resistance in under make up and foundation. We have developed two new materials and make up products based on our theory. A new fluoroalkyl acrylate-methacrylates copolymer designed for incorporation in under make up is extremely sebum resistant and sweat proof. Another new acrylate polymer designed for inclusion in foundation absorbs sebum and changes to a solid. Usage tests confirm it is possible to reduce MFD by using under make up and foundation which incorporate our new materials to cover where skin furrows are few or shallow

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.1009-1020
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• 1996

Direct-seeded rice can have comparable yield with transplanted rice if its inherent problems can be solved. It is a labor-saving technology and can significantly reduce production cost because seedling nursery , pulling , and transplanting are omitted. Turnaround time between cropping is reduced hence the possibility of a third annual crop. But direct-seeded rice is very vulnerable to pest attack (by birds, rats, and golden snails), desiccation, weed infestation, and prone to lodging resulting to unstable crop establishment and inconsistent yield. These problems can be solved by anaerobic seeding (sowing pre-germinated seeds under the soil). It requires precise seed placement into the soil to optimize its benefits. We developed a four-row anaerobic direct seeder (US $ 200 commercial price) for this purpose . It consist of a structural framework mounted with a drum -hopper metering device, flotation type drivewheels, spring-loaded and adjustable furrow closers, and furrow open rs, and a plastic rainguard. It can sow in line pre-germinated seeds into the soil thus permitting the use of mechanical weeders for a chemical-free weed control. Its performance was comparable with the Japanese two-row anaerobic seeder (costing US$400) in terms of seed placement and crop establishment. It was tested with five cultivars. Seeding rate varied from 38 kg/ha to 80kg/ha. Crop establishment ranged from 64 to 99 percent while grain yield varied from 3.0 t/ha to 5.4t/ha. A six-row anaerobic seeder was also developed and adapted to a powertiller for increased capacity , field efficiency , and easier operation. The anaerobic seeder is useful to farmers shifting to direct seeding to reduce rice production cost and to researchers conducting agronomic studies in direct-seeded rice. Blueprint of the machine is available free of charge from IRRI.

• ALGAE
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• v.39 no.2
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• pp.75-96
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• 2024

Rhodomonas (Cryptophyceae) and species assigned to this genus have undergone numerous taxonomic revisions. This also applies to R. marina studied here as it was originally assigned as a species of Cryptomonas and later considered a variation of R. baltica, the type species. Despite being described more than 130 years ago, R. marina still lacks a comprehensive characterization. Light and electron microscopy were employed to delineate a strain from western Greenland. The living cells were 18 ㎛ long and 9 ㎛ wide, elliptical in shape with a pointed to rounded posterior and truncated anterior in lateral view. Two sub-equal flagella emerged from a vestibulum, where also a furrow extended. In transmission electron microscopy, the furrow was associated with a tubular gullet and the pyrenoid embedded in a deeply lobed chloroplast. The chloroplast contained DNA in perforations and was surrounded by starch grains. A tubular nucleomorph was enclosed within the pyrenoid matrix. In scanning electron microscopy, the inner periplast consisted of rectangular plates with rounded edges and posteriorly these were replaced by a sheet-like structure. The water-soluble pigment was Crypto-Phycoerythrin type I (Cr-PE 545). A phylogenetic inference based on SSU rDNA confirmed the identity of strain S18 as a species of Rhodomonas as it clustered with congeners but also Rhinomonas, Storeatula, and Pyrenomonas. These genera formed a monophyletic clade separated from a diverse assemblage of other cryptophyte genera. To further explore the phylogeny of R. marina a concatenated phylogenetic analysis based on the SSU rDNA-ITS1-5.8S rDNA-ITS2-LSU rDNA region was performed but included only closely related species. The secondary structure of nuclear internal transcribed spacer 2 was predicted and compared to similar structures in related species. Using morphological and molecular signatures as diagnostic features the description of R. marina was emended.

• Animal Systematics, Evolution and Diversity
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• v.17 no.2
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• pp.185-190
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• 2001

Two vermiculture earthworms, Eisenia andrei Bouche, 1972 and Perionyx excavatus Perrier, 1872 are newly recorded to Korean fauna. E.andrei has no pale stripe on the intersegmental furrow zone and P.excavatus has clitellum in xiii-xvi. Descriptions of the species are provided in this paper, including illustrations of the ventral view, male pore region, and spermathecae.

• Korean Journal of Veterinary Research
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• v.34 no.4
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• pp.679-686
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• 1994

The development of esophagus in fetuses between 60, 90, 120 days of gestation and neonates of Korean native goats was investigated by light, scanning electron microscopy. The results were summarized as follows; 1. The esophageal wall appeared to be differentiated into the epithelium, lamina propria, tunica muscularis and tunica adventitia at 60 days of gestation. The esophageal epithelium was stratified cuboidal at 60 days, being transformed into stratified squamous epithelium at 90 days, and completely transformed into squamous epithelium an 120 days. 2. In scanning electron microscopy, the longitudinal furrows and ridges appeared on the epithelium of the esophagus of the fetuses at 60 days of gestation. The longitudinal furrow became deeper and microplicae appeared in 90-day-old fetuses. The transverse and longitudinal folds appeared on the epithelial surface of esophagus and the esophageal epithelium started to be keratinized in the neonates.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11b
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• pp.154-161
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• 2000

A series of soil bin experiment was carried to investigate the effects of rotary blade shape, rotational direction of rotary blade, number of blade and soil cutting disk blade on the characteristics of partial tillage. Among the three types of rotary blades, rotary blade for cultivator was considered to be proper for partial tillage of direct seeder considering the torque requirements and ratio of soil breaking. There is no need to attach so many blades to the rotary shaft. Four rotary blades were enough for efficient partial tillage by rotary tiller. Though soil cutting disk blade assisted the better formation of seedbed furrow, attachment of the soil cutting disk blade increased torque requirements.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.1041-1044
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• 1996

The plastic-film-covered hill planter is a new-type seeding machine, including tow types which are mounted by 11kw and 40 kw tractors. It is made up of fertilizing , plastic-film covering perforating film and hole seeding, soil sealing apparatus, and can work at 5-7kw/h. The plastic-film covering and seeding of cotton, corn and soybean can all use this machine. The plastic-film-covered hill planter is mainly composed of plastic film covering unit, drum-type hill-drop unit and furrow coverer, some other types are also equipped with fertilizer drill unit. It can do combined work of covering plastic film , sowing , plastic film perforating , soil covering at one time, and it is suitable to the covering plastic film as well as planting of the grandulated crops, such as cotton , corn, soybean and so on.

• Magazine of the Korean Society of Agricultural Engineers
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• v.35 no.4
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• pp.31-38
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• 1993

For efficient irrigation of structured horiculture and upland crops, a new technique of drip irrigation using the turbo-tape for Autumn Chinese cabbage was developed. The turbo-tape worked well, and based on this study The following results were obtained ; 1. The emission uniformity of the turbo-tape was very good with a uniformity coefficient of 92.5%. 2. Starting point of irrigation at 80% of the wilting point was better than at the wilting point itself. 3. The irrigation amounts for the Autumn Chinese cabbage cultured ranged 315 to 470mm depending upon the irrigation methods, turbo-tape irrigation method could conserve irrigation water about 37% compared to the furrow irrigation method. 4. Average yields were 2, 430g when the starting point of irrigation was at the wilting point, while 2, 680g when it was at 80% of the wilting point.