• Journal of Dental Rehabilitation and Applied Science
• /
• v.25 no.2
• /
• pp.157-169
• /
• 2009

The aim of this study was to evaluate effect of implant abutment screw coating treatment on joint stability, investigating mechanical properties of these. For this study used $ExFeel^{(R)}$ external hexed implant system and $15mm{\times}1mm$ discs. Experimental group was $1{\mu}m$ TiN, TiCN, TiC coated abutment screws and discs. To know mechanical property, i evaluated adhesion strength, surface hardness, using disc, corrosion test using screw. The results were as follows : rotation angle of coated screws increased than that of non-coated screw because of lower friction coefficient, especially TiC coated screw group had the largest value, but removal torque decreased in all coated screws (p<0.05). Torque loss before and after fatigue test was the smallest in TiC-coated screws, and the largest in non-coated screws (p<0.05), and there was no statistically significant difference between dry condition and wet condition of screws because of higher surface hardness and lower friction coefficient. From the above results, TiN, TiCN, TiC coating group had high abrasion resistance, especially TiC coated group which had low torque-consuming, high rotation angle as low friction coefficient will be considered to influence on implant abutment screw joint stability positively.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.38 no.1
• /
• pp.67-76
• /
• 2020

This study aims to elicit criteria regarding reassessment and designation of linear scenic sites henceforth. The results are as follows; First, based on the documents from the Cultural Properties Protection Committee of Korea, 23 out of 113 scenic sites in Korea were drawn, and their linear characteristics were categorized into four types including valleys, paths, rivers, and ridges. The linear scenic sites provide certain features in terms of sequence and direction, which results in the similar utilization among the sites which share the linear similarity. Second, the 23 sites mentioned above were intensely examined on the basis of six criteria for linear scenic sites through FGI, focus group interview. The criteria consist of six elements involving core resource(12), lot number(8), unclear(8), management path(5), ridge(4), basin(3). Third, the Cultural Heritage Administration has prioritized core resource since 2010, when designating a scenic site, whereas it tended to consider lot number as priority prior to 2010. It is thought that the authority gave consideration to issues related to private ownership of property in the scenic sites and the purpose of designation. Fourth, scenic sites are generally designated in accordance with the boundary of core resource, and in most cases, there are buffer zones alongside the core resource.

• Polymer(Korea)
• /
• v.30 no.5
• /
• pp.445-452
• /
• 2006

In this study, we investigated interaction of Schwann cells (SCs) with various cell-adhesive coated polymer surface. We used cell-adhesives that like a fibronectin (FN), fibrinogen(FG), laminin(LM), vitronectin (VN), poly-D-Iysine (PDL), and poly-L-Iysine (PLL) to coat PLGA film surface and evaluated the surface property of coated or not PLGA films by measurement of water contact angle and ESCA. SCs were cultured on coated or non-coated PLGA film surface, and then examined the cell adhesion and proliferation by cell count and SEM observation. Cell count results revealed initial cell adhesion related to protein adsorption on PLGA surface. In addition, serum content in media related to cell proliferation rate. In this result, we recognized that adhesion and proliferation of SCs were affected by specific cell-adhesives. In these results, we recognized that is important to provide the suitable surface environment according to cell types and culture condition for improvement of cell adhesion and proliferation.

• Polymer(Korea)
• /
• v.35 no.1
• /
• pp.30-34
• /
• 2011

In this study, the effects of the electron beam irradiation on the thermal behavior and the abrasion properties of the glass fiber reinforced nylon 12 was investigated. The electron beam irradiation was carried out over a range of irradiation dose from 100 to 600 kGy with additive crosslinking agents such as triallyl cyanurate (TAC), triallyl isocyanurate (TAIC) and trimethylolpropane trimethacrylate (TMPTMA) for enhancing the crosslinking effects. The gel contents were increased dramatically above 200 kGy. It was verified that the degree of crosslinking depends on the radiation dose. The decreases of the melting temperature and the area of endothermic peak were observed as increasing the absorbed dose in the results of DSC analysis. The enhanced thermal stability was confirmed by the increases of decomposition temperature by electron beam irradiation. Furthermore, the negative deviations of the abrasion loss and the abrasion coefficients confirmed the improvement of the abrasion properties of irradiated nylon 12, as evidenced by SEM observation on the abrasion surfaces. The addition of the crosslinking agents to nylon 12 during effectively improved the thermal behavior and the abrasion properties of nylon 12 by the electron beam irradiation.

• Food Science and Preservation
• /
• v.8 no.4
• /
• pp.469-474
• /
• 2001

Chemical composition of the water extract of three different kinds of bamboos was investigated to access nutritive sources. Bamboo stalks and leaves were extracted massively and concentrated to 3°Brix, and crude protein and fat contents of the extracts were respectively 0.56∼0.69% and 0.28∼0.58%. Main mineral contents of the extracts were K, P and Mg in order, and those were the highest in Wangdae stalks. In free sugar analysis of the extracts, Maengjongjuk stalks contained 1.1% sucrose, Somdae stalks contained 0.51% fructose and Wangdae stalks contained 0.6% glucose as the highest level. Organic acid contents of the extracts showed high level in acetic and malic acid which were 54.0 and 44.2mg% in extracts of Wangdae stalks respectively. Among amino acids, aspartic acid was contained the highest level in stalk extracts, and their concentrations were 42.2, 39.9 and 34.6mg% in Wangdae, Somdae and Maengjongjuk respectively. In leaf extracts, glutamic acid concentrations were higher than the other amino acids, and those were 19.3, 18.5 and 15.7mg% in Maengjongjuk, Wangdae and Somdae, respectively.

• Food Science and Preservation
• /
• v.24 no.7
• /
• pp.934-941
• /
• 2017

The objective of this study was to investigate the effect of corrugated packaging coated with aluminum (Al) on quality characteristics of red paprika during storage at $25^{\circ}C$. Characteristics such as weight loss, hardness, total phenolic content, antioxidant activities, polygalacturonic acid (PG) activity, and oxidative enzyme activities (polyphenol oxidase and peroxidase activities) of paprikas, packed in corrugated packaging with or without Al-coating were compared as a function of storage time. Al coating inside of corrugated box was found to inhibit PG activity, resulting in prevention of weight loss and maintenance of hardness of paprika during storage, compared to the control sample. This may be due to Al coating treatment that enhance moisture-proof property and hinder gas transmission of corrugated packaging. Furthermore, paprika in Al-coated-corrugated packaging was lower in oxidative enzyme activities than the control, which caused higher total phenolic content and antioxidant activities during storage. As a results, the Al coated-corrugated packaging can be used as a functional packaging material to extend the shelf-life and improve the storage quality of paprika by preventing their respiration and transpiration.

• Food Science and Preservation
• /
• v.24 no.5
• /
• pp.576-584
• /
• 2017

With the goal of developing a new functional fermentation milk using green tea powder (GP), milk was fermented with direct vat set (DVS) starter culture containing Streptococcus salivarius subsp. thermophilus, Lactobacillus paracasei and L. delbrueckii subsp. bulgaricus. We investigated fermentation characteristics and antioxidative activities of fermented milk supplemented with different concentrations (0.5, 1, 2, 3%) of GP. All samples were evaluated for pH, total acidity, viable cell count, and sugar contents. The pH of all samples decreased during fermentation, and the final pH ranged from 4.35 to 4.51. The acidity increased during fermentation, after the fermentation was completed, the titratable acidity was 0.8 to 1.1%. And viable cell count of all samples increased during fermentation, and the final viable cell count was 8.57 to 8.89 log CFU/mL. The sugar content decreased as the fermentation proceeded and finally reached 12 to $13^{\circ}Brix$. And increasing GP, decreased brightness and increased yellowness. Increasing GP concentration added to milk, improved DPPH free radical scavenging activity and ferric ion reducing activity of fermentation milk. The fermentation milk kept their pH, total acidity and viable cell counts standard of fermentation milk during the storage period at $4^{\circ}C$. These findings confirmed the possibility of development of the novel functional fermentation milk through the investigation of the quality characteristics of the fermentation milk added with GP.

• Journal of the Korean Magnetics Society
• /
• v.22 no.3
• /
• pp.109-115
• /
• 2012

NeFeB anisotropy bonded magnet has proposed a new paradigm of weight reduction of small motors by replacing the conventional ferrite permanent magnets with its high magnetic property of 25 MGOe during last five years. It has also advanced by leaps and bounds in the field of motor industry for automobiles and electric power tools. And it has led a new innovation of fifty percent weight lightening compared to its current motors by correctly focusing on fuel performance improvement through weight lightening that automobile industry chased. There was, however, another price skyrocketing in 2011 after China had announced its export regulation in rare earth materials in July, 2010. And this price change has an extensive impact on the industries that consume rare earth magnets. This environmental change has caused technical challenge to improve the performance by using least amount of rare earth elements in NdFeB anisotropy bonded magnets, and led to make a new technical approach to a new applied field. In this article, we will show how each nation deals with this industrial issue, and introduce development trend and application of anisotropic NdFeB bonded magnets, so-called MAGFINE made by Aichi Steel Corp.

• Korean Journal of Food Science and Technology
• /
• v.37 no.6
• /
• pp.905-911
• /
• 2005

Physical properties and compositions of dietary fiber sources (DFS) from peels of Asian pear fruit, Hosui, Niitaka and Chuwhangbae, were examined at different growth stages, young, unripe, and ripe fruits, to investigate their use as functional ingredients. Total dietary fiber (TDF) contents of DFS prepared from peels of three cultivars at three stages were high, 74.00-88.38%, with most being insoluble dietary fiber. Total phenolic compound contents of DFS were 1.64-4.46mg/g, with those of Niitaka and Chuwhangbae increasing with growth stages. Density of DFS from young fruit was significantly lower than those from unripe and ripe fruits (p<0.05), because particle size of DFS increased with growth stages within cultivars. Water-holding capacity (WHC) and oil absorption were 3.11-6.03g water/g solid and 1.98-2.57g oil/g sample, respectively. Young fruits, which showed lowest WHC value, had highest oil absorption value. Particle size of DFS had significant correlation with density, WHC, and oil absorption (p<0.05). Physical properties of DFS were mainly influenced by cellulose and uronic acid.

• Korean Journal of Food Science and Technology
• /
• v.30 no.3
• /
• pp.665-671
• /
• 1998

Protein-bound polysaccharides (PBP) were extracted from the mycellia of Lentinus edodes SR-1, and their anti-tumor activities and immunopotentiating properties were observed. The amounts of PBP needed to extend the doubling time twofold (1 unit) were found to be 1 mg for mouse leukemic cells $P_{388}\;and\;L_{1210}$; 4.4, 3.6 and 6.6 for bowel cancer cells, HCT-48, HRT-18, HT-29 respectively; and 2.6 mg for liver cancer cell, Hep G2. When $P_{388}\;and\;L_{1210}$ were treated with 4 mg of PBP, more than 90% of the cell number were reduced in 48 hours. However, 9 mg of PBP and 72 hrs of incubation time were needed to obtain the same effect for HRT-18, HT-29, and Hep G2. The significant reduction of cell size was observed as the amount of PBP and the incubation time increased. Mice spleen weight and plaque forming cell number increased when the cancer cells were treated with PBP.