• International Journal of Industrial Entomology and Biomaterials
• /
• v.30 no.2
• /
• pp.81-85
• /
• 2015

Recently, many researchers have studied silk sericin because of its high water retention, good wound healing, good cyto-compatibility, and blood-glucose- and cholesterol-lowering effects. Although sericin film can be used in wound dressing and cosmetic packs, its poor mechanical properties have prevented its use in industrial fields. In the present study, sericin was obtained from different silkworm varieties, and the effect of silkworm variety on the structure and properties of sericin was examined. Except for a small difference in serine content, no significant difference in sericin was noted among the silkworm varieties. In addition, silkworm variety almost had no effect on solution viscosity, implying that it does not influence the molecular weight of sericin. Mechanical properties of sericin film were strongly affected by silkworm variety. Wonwon 126 showed the best mechanical properties, while N74 and Geumgwangju displayed the worst properties.

• Journal of the Korean Ceramic Society
• /
• v.46 no.1
• /
• pp.102-107
• /
• 2009

This study has been focused on an effective surface finishing method combining ELID (ELectrolytic In-process Dressing) and MAP (Magnetic Assisted Polishing) for the nano-precision mirror grinding of glass-lens molding mould. ELID grinding is an excellent technique for mirror grinding of various advanced metallic or nonmetallic materials. A polishing process is also required for elimination of scratches present on ELID grinded surfaces. MAP has been used as polishing method due to its high polishing efficiency and superior surface quality. It also presents some techniques for achieving the nanometer roughness of the hard material such as WC-Co, which are extensively used in precision tooling material.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.4 no.3
• /
• pp.12-24
• /
• 1995

Various surface grinding experiments using resin bonded diamond abrasive wheels are carried out for tungsten carbide materials in order to minimize the damage on the ground surface and to purse the precise dimension compared to conventional grinding machine. When grinding quality is constant, theoretical grinding effect is changed according to the speed of workpiece. Accordingly, grinding forces, which are Fn, Ft, were analyzed for the machining processes of tungsten-carbide material to obtain optimum grinding conditions. Brief investigation is carried out to decrease the dressing efficiency of resinoid bonded diamond grinding wheel to grind tungsten-carbide. Truing is also carried out to provide a desired shape on a wheel or to correct a dulled profile. High quality in dimensional accuracy and surface are often required as a structural components, therefore 3-points bending test is carried out to check machining damage on the ground surface layer, which in one of sintered brittle material. From this experimental study, some useful machining data and information to determine proper machining condition for grinding of tungsten-carbide materials are obtained.

• International Journal of Precision Engineering and Manufacturing
• /
• v.1 no.2
• /
• pp.61-66
• /
• 2000

In this paper, we discuss the machining characteristics of HDD glass. Glass is now being used globally as a data storage device, Such glasses are usually machined by lapping by this technique requires a long machining time, resulting in low productivity, For this reason, we examine the possibility of EILD grinding in HDD glass workpieces, A move to ELID grinding may result in substantial cost reduction. Our purpose is to investigate the grinding characteristics of HDD glass in ELID grinding. The bonding materials for fixing the abrasives of cast iron, cobalt and bronze are applied, and grinding conditions such as rotation speed and feeding are varied. Results show that with the use of ELID, mirror surfaces can be achieved with high efficiency.

• Journal of the Korea Furniture Society
• /
• v.24 no.4
• /
• pp.345-349
• /
• 2013

Yellow poplar is well known commercial hardwood species in the world because of its availability, rapid growth, large size, excellent form, early natural pruning, and the good working quality of the wood. Therefore, yellow poplar (Liriodendron tulipifera L.) has been adopted in South Korea for decades ago, and its cultivating the saplings and silvicultural system have been studied. However, yellow poplar is still embroiled in controversy for utilization of use and worth. This species has not only advantages such as lower weight, light color, and higher machinability and bending processing, but also has disadvantages which are bad smell and different colors on heartwood and sapwood. In this study, the objective was that use of yellow poplar board as furniture materials by drying and painting process. Thirty years old yellow poplar was cut and dried for 7 days by high-frequency dryness. Adjustment of color tone to walnut color was conducted with multiple colorants and various number of spread times. Uniform color of yellow poplar on heartwood and sapwood was accomplished by applying 1 time stain (green), 2 times transparent primer, 1 time middle-painting (walnut), and 2 times top-painting (walnut) in sequentially. The painted yellow poplar board was used to manufacture table and dressing table. During the furniture manufacture process, no critical issues were occurred on part of jointing and painting. This painting method may be useful data for future use of yellow poplar as furniture materials.

• Polymer(Korea)
• /
• v.35 no.6
• /
• pp.553-557
• /
• 2011

Poly(vinyl alcohol) (PVA)/waterborne polyurethane (WBPU)/montmorillonite clay (MMT) nanocomposite nanofibers were prepared using electrospinning technique of aqueous solutions. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction and thermal gravimetric analyzer were used to characterize the morphology and properties of the nanocomposite nanofibers. Since PVA, WBPU and MMT are hydrophilic, non-toxic and biocompatible materials, these nanocomposite nanofibers can be used for filter and medical industries as wound dressing materials, antimicrobial filters, etc.

• Restorative Dentistry and Endodontics
• /
• v.44 no.3
• /
• pp.32.1-32.13
• /
• 2019

Calcium hydroxide (CH) is the gold-standard intracanal dressing for teeth subjected to traumatic avulsion. A common complication after the replantation of avulsed teeth is root resorption (RR). The current review was conducted to compare the effect of CH with that of other intracanal medications and filling materials on inflammatory RR and replacement RR (ankylosis) in replanted teeth. The PubMed and Scopus databases were searched through June 2018 using specific keywords related to the title of the present article. The materials that were compared to CH were in 2 categories: 1) mineral trioxide aggregate (MTA) and endodontic sealers as permanent filling materials for single-visit treatment, and 2) Ledermix, bisphosphonates, acetazolamide, indomethacin, gallium nitrate, and enamel matrix-derived protein (Emdogain) as intracanal medicaments for multiple-visit management of avulsed teeth prior to the final obturation. MTA can be used as a single-visit root filling material; however, there are limited data on its efficacy due to a lack of clinical trials. Ledermix and acetazolamide were comparable to CH in reducing RR. Emdogain seems to be an interesting material, but the data supporting its use as an intracanal medication remain very limited. The conclusions drawn in this study were limited by the insufficiency of clinical trials.

• Journal of the Korean Applied Science and Technology
• /
• v.11 no.2
• /
• pp.39-54
• /
• 1994

I am going to survey major topics relating to the title by analyzing the following statistical data. 1 : Global trend of production and import of oil and relating materials 2 : Global trend of major oil production 3 : Capacity of Japanese factory for oil production 4 : Situation of mechanical expression based on raw materials 5 : Change of production amounts of Oil products 6 : Oil production of each items 7 : Imported amounts of oil products 8 : Vegetable oil meals, production, import and global trend 9 : Production of mayonnaise, dressing and edible processing oils 10 : Intake of nutrients, supply of lipids, and consumption of oils 11 : Global production of oleochemicals 12 : Sales amount of oleochemicals 13 : Capacities of fatty acid and fatty alcohol factories 14 : Oleochemical production in 1995 15 : Oleochemical procuction in asia 16 : Production of surfactants for industrial use 17 : Sales amount of detergents and washing materials 18 : Production of soap and synthetic detergent in Japan 19 : Consumption of soap. detergent, and synthetic detergent 20: Relation beween synthetic detergent production and popularization 21 : Biodegradability of soft detergent

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.12
• /
• pp.6504-6513
• /
• 2013

The result can be summarized as follows. First, the following periodically changing characteristics were examined:roof form(gambrel/hipped-flat-gable), structure of roof and wall(wood-framed-cement masonry-RC-Light iron framed), roof material(thatched-tiled-slate-cement/steel sheet-asphalt/sandwich panel/mortar water-proofing), wall material(clay plaster/lime plastered-dressing tile/bricks-painting on the cement plastering-native stone dressing/siding/tile), fence material(masonry of stone and cement bricks), and courtyard materials(clay and concrete). Secondly, the regionally changing characteristics of those elements, rural housing structure, roof form, roof structure material, wall finishing material, fence and courtyard material in the outer space, differed according to the location of rural housing, i.e.north, middle, south region. The changing characteristics of both the roof structure and wall structure are similar to those of the three regions.

• Journal of the Korean Society of Costume
• /
• v.62 no.7
• /
• pp.205-219
• /
• 2012

The purpose of this study is to develop comfortable patient gown for spinal surgery patients. The results of the survey confirmed inconveniences and problems with the current gown, and a new gown style was recommended. The recommended changes addressed design, pattern, and materials. The final experimental design for the top of the new patient gown is a wrap style that moves the center opening of the gown to the side and enables patients to control the length of the sleeves by attaching two snaps. The cutting line is aligned with the back brace location, and the issue of repeated bunching of the gown material by the brace was solved by substituting 100% knitted structure fiber. The sleeve length can be adjusted with snaps on the sleeve cap and hem. When lifting up the gown for treatment on specific areas of the body, doctors open the edge of the right side of the gown in order to lift up the top. The bottom of the new patient gown was made from 100% cotton knitted structure fiber, and it enables patients to control the length of pants by attaching two snaps on the side. The results of an on-site dressing suitability evaluation and a flexibility evaluation with respect to dressing/undressing indicated that the new patient gown was much better received than the existing gowns (A and B). Our hypothesis regarding new patient gowns was supported in both the fit and design categories.