• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.6 no.6
• /
• pp.468-472
• /
• 2005

In order to prevent adhering of molten glass on a mold wall, the wall is swabbed with lubricant oil before forming. However, the swabbing process can be removed from the entire processes of the glass forming if the mold wall is made of a porous sintered material. The purpose of the present study is to manufacture a sintered material(having a sintered density of $85{\~}90\%$)which is the most appropriate into. plane material for a glass mold. For the research, SUS310L-based coarse powder (${\~}150{\mu}m$) and SUS420J2-based fine powder ($40{\~}50{\mu}m$) were used for the compact materials, and effects of compaction pressure and sintering condition(atmosphere, temperature) were investigated. The results obtained were as fellows. (1) By means of solid phase sintering, a desired sintering density could not be achieved in any case when using a 310L-based powder having a large particle size. (2) When sintering green compacts(compaction pressure of $2ton/cm^2$) in a commercial vacuum furnace(at $1300^{\circ}C$ for 2 hours), the sintered compacts had densities of $6.2g/cm^3(79\%)$ for 310L + 0.03$\%$B, $6.6g/cm^3 (86\%)$ for 420J2, $7.3g/cm^3(95\%)$ for 420J2+(0.03)$\%$B, and $7.6g/cm^3(99\%)$ for 420j2+(0.06)$\%$B, respectively. As a result, it is regarded that sintered compacts having a desired porosity may be achieved by vacuum sintering the 420J2-based powder (low pressure compaction) and the 310L+0.03$\%$B-based powder (high pressure compaction).

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.305-305
• /
• 2017

Seoritae with green cotyledons refers to Korean native black beans harvested when the frost falls because the maturity is late. It is one of the beans preferred by consumers because of its softness and high sugar content. Because of late maturity, if the agricultural work is delayed by weather or agricultural schedule in green cotyledon black soybean (Seoritae), it affects seriously harvest and yield of soybeans. The aim of this study was to investigate the marginal seeding period on June 30, July 10 and July 20 in Cheongju and Jecheon area in Korea to produce stable soybean yield. The yields of green cotyledon black soybean as seeding date in Cheongju area are as follows: Seolitae (Yeoncheon), Seoltae (Goesan) and Seoritae (Gogseong), which increased by 23%, 56%, 23% and 40%, respectively, compare to July 10th to June 30th. As soybean sowing is delayed, the quality of soybean seeds has decreased due to the increase of immature seeds and fungal damaged seeds. The contents of anthocyanin in Cheongju area a functional substance of soybeans, was high on July 20 for Heukcheong, on June 30 for Seolitae (Yeoncheon), on July 10 for Seoritae (Goesan). The yields of Heukcheong and Seolitae (Yeoncheon) in Jecheon area were increased by 5% and 17%, respectively, compare to July 10th to June 30th, while Seolite (Goesan) and Seolite (Gogseong) were high in yields on June 30th. Similarly in Cheongju area, as the sowing period is delayed, the number of immature and mold damaged seeds in Jecheon area increased. The contents of anthocyanin in Jecheon area was high on July 10 for Heukcheong, on June 30 for Seolitae (Yeoncheon) and Seolitae (Goesan). From the above results, Sowing marginal date of green cotyledon black soybeans (Seolitae) in Cheongju area increased 30% in sowing on July 10 and increased 2% in sowing on July 20 compared to June 30. And Sowing marginal date of green cotyledon black soybeans (Seolitae) in Jecheon area increased 2% in July 10 compared to June 30, and the yield decreased rapidly on July 20. We have identified the seeding time limit of green cotyledon black bean in Chungbuk province. It will be possible to provide a variety of crop selection after double cropping of farmers. And by knowing the yield and seed quality of soybean according to sowing date, farmers will observe appropriate sowing period of soybeans for high quality. From the viewpoint of consumers, functional substances of Seoritae will meet the desire for health.

• Mycobiology
• /
• v.31 no.2
• /
• pp.74-80
• /
• 2003

Isolates of Trichoderma spp. collected from Pleurotus ostreatus and P. eryngii beds, which included loosened substrate compactness and development of green colour, were grouped into three species. The occurrence of different species of Trichoderma was as T. cf. virens(70.8%), T. longibrachiatum(16.7%) and T. harzianum(12.5%). The conidia of Trichoderma spp. were ellipsoidal, obovoid and phialides were bowling pins, lageniform and the length of phialides was $3.5{\sim}10.0{\times}1.3{\sim}3.3{\mu}m$. Phialides of T. cf. virens and T. harzianum were tending clustered, but it was solitary disposition in T. longibrachiatum. T. cf. virens was characterized by predominantly effuse conidiation, sparingly branched, and fertile to the apex and it was penicillate type. RAPD analysis could detect variability amongst three different species of Trichoderma using two newly designed URP-primers. However, intra-specific variation could not be detected in all the isolates except for rDNA sequence data classified Trichoderma isolates into three distinct groups representing three species. The profiles of rDNA sequences of isolates representing a species showed high similarity in T. cf. virens and T. harzianum. However, there was a variation in rDNA sequences of isolates representing T. longibrachiatum. The results of present study reveals that molecular techniques of RAPD and rDNA sequencing can greatly aid in classification based on morphology and precise identification of fast evolving species of Trichoderma.

• Research in Plant Disease
• /
• v.9 no.4
• /
• pp.217-220
• /
• 2003

A severe fruit rot of Persimmon (Diospyros kaki cv: Fuyu) was occurred during the storage and transport that infected with blue mold in Sweet Persimmon Experiment Station, Gyeongsangnam-do Agricultural Research and Extension Services, Korea. Fruit surfaces were infected with the fungus first and the colonized fungus formed mycelial mats. From the point of infection, fruits become collapsed and mostly ruptured. The pathogenic fungus from infected fruits was isolated and cultured on PDA. Colony color of the fungus was white at frist than became green on Malt Extract Agar and Czapek Yeast Extract Agar. Conidia were ellipsoid subglobose and 2.6${\sim}$3.8 ${\times}$ 2.4${\sim}$3.8 ${\mu}m$ in size. Stipes were 86${\sim}$320 ${\times}$ 2.8${\sim}$4.3 ${\mu}m$ in size. Rami were 7.5${\sim}$32.6 ${\times}$ 2.6${\sim}$4.2 ${\mu}m$ in size, Ramuli were 12.4${\sim}$14.8 ${\times}$ 3.2${\sim}$3.8 ${\mu}m$ in size, Metulae were 8.9${\sim}$13.6 ${\times}$ 2.8${\sim}$4.6 ${\mu}m$ in size. Phialides were ampulliform, 8.2${\sim}$12.4 ${\times}$ 2.3${\sim}$3.6 ${\mu}m$ in size. Based on the cultural and mycological characteristics and pathogenecity test on host plants, the fungus was identified as s, This is the first report on the blue mold of Persimmon (Diospyros kaki) caused by P. crustosum in Korea.

• Research in Plant Disease
• /
• v.12 no.3
• /
• pp.290-293
• /
• 2006

A fruit rot of sweet persimmon(Diospyros kaki cv. 'Fuyu') that infected with blue mold was found during the storage and transport in Jinju Gyeongnam Province, Korea. Fruit surfaces that infected with the fungus were formed water soaked lesion at first then gradually colonized with the fungus and formed mycelial mats. From the point of infection, fruits become sunken and mostly ruptured. The pathogenic fungus was isolated from infected fruits and cultured on potato dextrose agar. The colonies of the pathogenic fungi were white at frist then became greyish green on malt extract agar. Conidia were ellipsoidal and $2.6{\sim}3.8{\times}2.4{\sim}3.8{\mu}m$ in size. Phialides were ampulliform, verticilate of 3-7, $8.0{\sim}9.2{\times}2.0{\sim}3.0{\mu}m$ in size. Metulae were verticils of 2-4, smooth, $9.0{\sim}12.6{\times}3.0{\sim}4.6{\mu}m$ in size. Ramuli were groups 1-3, smooth, $11.0{\sim}17.6{\times}2.3{\sim}3.0{\mu}m$ in size. Rami were groups 1-2, $7.5{\sim}32.6{\times}2.6{\sim}4.2{\mu}m$ in size. Stipes were septate, smooth, thin walled, $56{\sim}302{\times}2.8{\sim}4.0{\mu}m$ in size. Penicilli were mostly quaterverticillate. Based on the cultural and mycological characteristics as well as pathogenicity test on host plants, the fungus was identified as Penicillium expansum. This is the first report on the blue mold of sweet persimmon(Diospyros kaki) caused by P. expansum in Korea.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.8 no.1
• /
• pp.73-78
• /
• 2005

It was aimed to promote Cyrtomium falcatum as a material for interior landscape by validating it indoor adaptability in the indoor environment, especially irrigation times, soil treatment and drainage level. Irrigation times were 2 times per week and 7 times per week. Soil treatment and drainage level were carried out drainage-peatmoss : vermiculite : perlite=1 : 1 : 1(D-PVP), peatmoss : vermiculite : perlite=1 : 1 : 1(PVP), drainage-saprolite : leaf mold=1 : 1(D-SL) and saprolite : leaf mold=1 : 1(SL). 1. Top of growth was better with irrigation 7 times per week than irrigation 2 times per week but indoor adaptability was decreased and shown yellowish green. 2. In case of soil treatment, growth was better with saprolite : leaf mold=1 : 1 but indoor growth adaptability was decreased than peatmoss : vermiculite : perlite=1 : 1 : 1. 3. Plant height and blade length were increased under non-drainage treatment but indoor adaptability, number of new fronds and number of sporophyll were decreased under drainage treatment, regardless of irrigation times and soil treatment. 4. Photosynthetic rate(Pn) was the highest in the drainage-peatmoss : vermiculite : perlite=1 : 1 : 1 treatment of irrigation 2 times per week and was the lowest in the saprolite : leaf mold=1 : 1 treatment of irrigation 7 times per week.

• Food Science and Preservation
• /
• v.15 no.6
• /
• pp.791-795
• /
• 2008

In order to establish the method to prepare and use the sulfur dioxide gas generating agent in low temperature storage of grape fruits, the $SO_2$ generation capacity from various sulfite compounds was investigated, and the method to regulate $SO_2$ gas generation and to detect the gas was developed. The conidial germination and mycelium growth of Botrytis cinerea which causes gray mold disease during grape fruit storage was completely inhibited at the $SO_2$ gas concentration of 400 ppm and 3200 ppm, respectively. Sodium hydrosulfite generated the most amount of $SO_2$ gas among the investigated 5 different sulfite or bisulfite compounds. By adjusting the number of pinholes on packaging film of the compound or by adding pH adjusting agent, e.g. citric acid or phosphates, it was possible to regulate the amount and duration of $SO_2$ gas generation from the compound. Because malachite green was quantitatively discolored by $SO_2$ gas, the solution or impregnated paper with the compound could be practically utilized as a indicator detecting $SO_2$ gas. Finally, when Muscat Bailey A grape was stored at low temperature with $SO_2$ gas generating agent, the disease incidence was reduced after storage.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.411.1-411.1
• /
• 2014

This study evaluates the utility of an antibacterial microneedle composed of green tea extract (GT) and hyaluronic acid (HA), for the efficient delivery of GT. These microneedles have the potential to be a patient-friendly method for the conventional sustained release of drugs. In this study, a fabrication method using a mold-based technique to produce GT/HA microneedles with a maximum area of ${\sim}60mm^2$ with antibacterial properties was used to manufacture transdermal drug delivery systems. Fourier transform infrared (FTIR) spectrometry was carried out to observe the potential modifications in the microneedles, when incorporated with GT. The degradation rate of GT in GT/HA microneedles was controlled simply by adjusting the HA composition. The effects of different ratios of GT in the HA microneedles were determined by measuring the release properties. In HA microneedles loaded with 70% GT (GT70), a continuous higher release rate were sustained for 72 h. The in vitro cytotoxicity assays demonstrated that GT/HA microneedles are not generally cytotoxic to chinese hamster ovary cells (CHO-K1), human embryonic kidney cells (293T), and mouse muscle cells (C2C12), which were treated for 12 and 24 h. Antimicrobial activity of the GT/HA microneedles was demonstrated by ~95% growth reduction of gram negative [Escherichia coli (E. coli), Pseudomonas putida (P. putida) and Salmonella typhimurium (S. typhimurium)] and gram positive bacteria [Staphylococcus aureus (S. Aureus) and Bacillus subtilis (B. subtilis)], with GT70. Furthermore, GT/HA microneedles reduced bacterial growth in the infected skin wound sites and improved skin wound healing process in rat model.

• Restorative Dentistry and Endodontics
• /
• v.26 no.2
• /
• pp.180-187
• /
• 2001

The structure of current guides is largely illogical and without any rational use of color ordering. The shade guides are generally made of plastic (rather than the actual composite material) and do not accurately depict the true shade. translucency. or opacity of the composite resin after polymerization. To solve this problem, information based on evaluations of natural teeth and material that use the same method and experimental conditions is necessary. The present investigation measured the color of natural maxillary anterior teeth in vivo and compared the results with those of composite resins. 269 Korean subjects were selected for this study. Intact central incisor. lateral incisor. and canine were selected. The clinical crowns were free of caries or restorations. The middle site of the coronal portion on the labial surface of the tooth was measured by Chroma Meter. The five light activated. resin-based materials (Amelogen, Denfil, Elitefil, Spectrum, Z100) were used in this study. Resin composite was condensed into plastic mold with a diameter of 8mm and a thickness of 4mm. pressed between glass plates to flatten the surfaces. and polymerized using a Visilux II visible light activation unit. The surfaces were polished sequentially on wet sandpaper. Color measurements of each specimen were accomplished by Chroma Meter. A computer program that compares each tooth color with each composite resin color was written and the minimum CIELAB color difference ($\Delta$E$^*$) between tooth and each material was calculated. Under the conditions of this study: 1. Teeth tend to become darker with advancing age. 2. Canines were darker. more yellow. and less green than incisors. 3. The teeth from the women were lighter. more green. and less yellow than the male teeth. 4. In general. composite resins were lighter. more green. and less yellow than teeth. Deficiencies were noted in Hues in YR range. 5. Mean color differences between the five composite resin products and teeth were detectable to the naked eye($\Delta$E$^*$>1.0). 6. In comparing the mean $\Delta$E$^*$ values of materials. Spectrum showed the least followed by Z100, Elitefil, Amelogen, Denfil in increasing order.

• Journal of the Korean institute of surface engineering
• /
• v.34 no.6
• /
• pp.568-574
• /
• 2001

Mixed powders of Fe + 0.7% C, Fe + 0.7% C + 1.6% Cu, and Fe + 0.7% C + 0.3% MnS were pressed in a mold so that the green-compact densities were 6.3, 6.5, 6.7, and 6.9 g/㎤, respectively. Then, the compacts were sintered at $1125^{\circ}C$ for 30 minutes and subsequently steam treated at $600^{\circ}C$ for 60 minutes. From the results, it was found that the overall properties of the steam-treated compacts, such as the weight gain of the sintered compacts, the diffusion of oxides into the sintered compacts, the surface hardness, and the formation of surface oxide layer, were primarily influenced by the density of the compacts and the oxides that were formed on the surface of the compacts by the steam treatment.