• Restorative Dentistry and Endodontics
• /
• v.32 no.2
• /
• pp.111-120
• /
• 2007

The purpose of this study is to evaluate the effects of surface treatment and composition of reinforcement material on fracture strength of fiber reinforced composite inlay bridges. The materials used for this study were I-beam, U-beam TESCERA ATL system and ONE STEP(Bisco, IL, USA). Two kinds of surface treatments were used; the silane and the sandblast. The specimens were divided into 11 groups through the composition of reinforcing materials and the surface treatments. On the dentiform, supposing the missing of Maxillary second pre-molar and indirect composite inlay bridge cavities on adjacent first pre-molar disto-occlusal cavity, first molar mesio-occlusal cavity was prepared with conventional high-speed inlay bur. The reinforcing materials were placed on the proximal box space and build up the composite inlay bridge consequently. After the curing, specimen was set on the testing die with ZPC. Flexural force was applied with universal testing machine (EZ-tester; Shimadzu, Japan). at a cross-head speed of 1 mm/min until initial crack occurred. The data was analyzed using one-way ANOVA/Scheffes post-hoc test at 95% significance level. Groups using I-beam showed the highest fracture strengths (p<0.05) and there were no significant differences between each surface treatment (p>0.05) Most of the specimens in groups that used reinforcing material showed delamination. 1. The use of I-beam represented highest fracture strengths (p<0.05) 2. In groups only using silane as a surface treatment showed highest fracture strength, but there were no significant differences between other surface treatments (p>0.05). 3. The reinforcing materials affect the fracture strength and pattern of composites inlay bridge. 4 The holes at the U-beam did not increase the fracture strength of composites inlay bridge.

• Korean journal of applied entomology
• /
• v.47 no.3
• /
• pp.217-226
• /
• 2008

Development of T. urticae was studied on the leaves of eggplant grown in hydroponics with potash contents of 0 mM, 2 mM, 6 mM, and 12 mM. As the levels of potash increased, that of nitrogen decreased and that of P, K, Mg increased in the plant. While contents of crude protein and fiber decreased, those of ash and sugar increased. Carbohydrate content was the highest at 2 mM. Water contents increased as those of potash increased with the exception at 0 mM. Biomass was the heaviest as 552.7 g at 6 mM and the lightest at 0 mM. Leaf thickness and the content of chlorophyll increased as the content of potash increased. Laboratory leaf disc tests provided with various potash levels revealed that feeding and oviposition preferences of T. urticae were high at 6 mM and 12 mM, respectively. Ratio of damaged leaf by naturally occurring T. urticae on eggplants of 99 days post-transplant in the greenhouse was the highest at 6 mM. Development of immature stages of T. urticae shortened as the levels of potash increased with a less tendancy in male than in female. No differences were detected in adult longevity and oviposition period but the number of eggs laid was the most as 84.7 at 6 mM and the least as 40.6 at 0 mM. There were no differences in the rate of egg hatch and the ratio of sex. $R_o,\;r_m,\;and\;{\lambda}$ were the highest at 6 mM and the lowest at 0 mM. T and Dt were the lowest at 6 mM and the highest at 0 mM. There was a descending trand of T. urticae developmet when levels of potash either gets high or low in the hydroponics.

• Korean Journal of Agricultural Science
• /
• v.18 no.2
• /
• pp.164-179
• /
• 1991

Korean agriculture has encountered two problems. One is internal income disparity between rural and urbarn area and the other is external Uruguay Round trade problems as an abolition of direct and indirect import barriers, reduction in export subsidies and to reduce internal price supports. These problems will be brought severe farm problems such as decreasing farm household income and repressing agricultural growth in the near future. Considering the above inevitable facts Korean government has implemented several development projects such as rural industrial area development project, rural special production area development project, leisuresight seeing farm development project, traditional food development project, unskilled labor training project for off-farm employment and so on, to increase farm household income through off-farm income increase. This study was mainly concentrated on the identification of operational problems and post evaluation of the rural special production area development projects which aimed at increasing non-farm incomes and giving employment opportunity for rural farmers in small factories processing regional special farm products and mine products. The main findings and problems to be solved for the successful project implementation are as followed ; 1. Total number of the special production area development projects as of the end of 1991 was amount to 138, and total number of farm household participated were estimated at 2,079, and total amount of off-farm income per farm household was reached to 3,011 thousand won. 2. The total number of processed special products have increased from 21 items in 1981 to 56 items in 1991. On the other hand the total number of farm household participated in the projects have decreased from 2,518 to 2,079 during same period. 3. Total amount of investment for the projects has increased from 1,429 million won in 1981 to 24,760 million won in 1991 but the rate of G'T loan of the total investment has reduced from 24.5% to 5.2% during same period. 4. 138 special production area development project are classified into 6 kinds of commodity groups such as 19 of general industrial good production areas, 52 of folks-industrial art objects production areas, 39 of food processing areas, 9 of fiber and texstile processing areas, 18 of agricultural and fishery inputs processing areas and 1 of stone processing area. 5. The total production value in 1990 was estimated 20,169 million won of which export was amount to 2,627 million won. 6. The finacial rate of return of the UNGOK KUGIJA Tea processing Project operated by UNGOK coops and BAKSAN ginseng tea processing project were estimated at 45.4% (B/C Ratio=1.17, NPV=152.5 million won) and 17.7% (B/C Ratio=1.12, NPV=120.2 million won) respectively. 7. More favorite terms and condition of the loan including collateral problems have to be given to farmers participated. Heavy investment and G'T subsidy policies should be started for the successful project implementation anf farm household income increase. 8. To expand market demand of the rural special goods G'T have to provide special program of TV or other mass media for commodity propaganda and the total cost concerned must be supported by G'T subsidy. 9. The special farm products as GUGUJA,MOSI'Ramie', Ginseng. SOGOKJU,HEMP,Mushroom.DUGYUNJU and Chesnut processing projects have to be propelled and expanded for off-farm income increase in Chung Nam Province. 10. Direct operational pattern of the special production area by coops is more favorable to farmers and recommendable considering with off-farm income increase and market demand creation throughout Korea. 11. In rural area, special organizations for project appraisal are not exist. Accordingly special training program, project appraisal, formulation and preparation for civil servants concerned have to be prepared for project selection and sound implementation under limited budget and financial support.

• Journal of Ginseng Research
• /
• v.32 no.4
• /
• pp.324-331
• /
• 2008

Introduction : Korean red ginseng has been shown to have an preventive effect on atheroma formation and enhancing effect on nitric oxide synthesis in endothelial cell inducing vasodilatation. However, there are few studies showing the effect of Korean red ginseng on blood pressure and vascular(endothelial) pathologic changes together. We designed this study to show changes of blood pressure and vascular pathologic findings with Korean red ginseng administration compared with Chinese red ginseng and control for 3 months in rats. Materials and methods : We studied the in vitro hypotensive effect and effect on vascular pathologic changes of Korean red ginseng compared with Chinese red ginseng and control. Rats were randomly assigned to three groups(Korean red ginseng, Chinese red ginseng and control) and evaluated by blood pressure and aortic vascular(endothelial) pathologic changes monthly during 3-month administration. All results were analyzed by paired T-test, ANOVA and post-hoc. Results : Blood pressure lowering effect was noted on Korean red ginseng and Chinese red ginseng compared to control. Especially, in Korean red ginseng group, hypotensive effect was showed in first and second month, but, in Chinese red ginseng group, it was just noted in first month. In case of vascular(aortic endothelial) pathologic finding, endothelial wall thickening and elastic fiber tearing were noted in Chinese red ginseng group compared with Korean red ginseng group and control with statistical significance.(p<0.05) Discussion : These results suggested Korean red ginseng could have more hypotensive effect and maintenance rather than Chinese red ginseng. And the difference of hypotensive effect between Korean red ginseng and Chinese red ginseng might has some association with difference of vascular pathologic findings in each group. However, further evaluation and research of other mechanism will be needed to convince this hypothesis.

• Journal of Apiculture
• /
• v.32 no.3
• /
• pp.139-146
• /
• 2017

Floral scent emitted from many plants is the critical factors for pollinator attraction and defense for adaptation in environments. The fragrance components of flowers are different in composition by geographical origins, climate factors and the development stages of flowers. In the present study, we investigated the volatile-floral compounds in flowers of Robinia pseudoacacia L. and defined the chemical contribution for flowering periods. The volatile compounds analysis was performed by gas chromatography with mass selective detector after solid phase microextraction (SPME). We reported different compositional features of fragrance compounds according to flowering periods. The abundant compounds identified in stage 1 were ${\alpha}$-pinene (66.80%) and ${\beta}$-pinene (26.53%). Those of the stage 2 were (Z)-${\beta}$-ocimene (37.57%), ${\alpha}$-pinene (15.16%), benzaldehyde (16.63%), linalool (12.13%). The volatiles of stage 3 comprised an abundance of (Z)-${\beta}$-ocimene (64.94%), ${\alpha}$-pinene (9.84%), linalool (8.92%), benzaldehyde (1.71%). Leaf volatiles were distinct from those in the reproductive plant parts by their high relative amount of (E)-${\beta}$-ocimene (23.50%) and (Z)-3-Hexenyl acetate (27.87%). Differences in flower scents of the different stages and leaves are discussed in light of biochemical constraints on volatile chemical synthesis and of the role of flower scent in evolutionary ecology of R. pseudoacacia.

• Journal of Animal Science and Technology
• /
• v.51 no.5
• /
• pp.369-378
• /
• 2009

Protein fractionation was evaluated from whole crop silages of rye (RS), wheat (WS), triticale (TS), oat (OS), barley (BS), and rice straw silage (RSS), and in vitro trial was carried out to examine the effect of silage and extraction of soluble protein on fermentation characteristics, total gas production and degradation. Soluble protein of silages was extracted with borate-phosphate buffer, and fermentation characteristics, gas production and degradation of silages were estimated by incubating anaerobically the mixed solution of strained rumen fluid and artificial saliva (1:1, v/v) containing dried and ground silages placed in nylon bag at $39^{\circ}C$ up to 48h. Soluble protein (SP) content was lowest for RSS as 2.11% in total CP compared to those for other silages. Highest A fraction (NPN) was observed from RS (74.33% of total CP) while those from TS and RSS were relatively low (48%). B2 fraction was relatively higher for RS, RSS and WS than for TS and BS. $B_3$ fraction was lowest in WS among silages. C fraction (27.07) in RSS was higher than in other silages (1.40~9.93%). pH in incubation solution was increased (P<0.01~P<0.001) for extracted silages up to 12h but decreased (P<0.01) at 48h for non-extracted ones. Contents of ammonia-N (P<0.001) and total VFA (P<0.01~P<0.001) were higher for non-extracted silages than for extracted ones. Acetate proportion was increased (P<0.001) in buffer extracted silages while those of propionate and butyrate were decreased (P<0.001) up to 24h incubation. Increased (P<0.001) total gas production was obtained from non-extracted silages up to 12h while gas production was increased (P<0.01) in extracted ones thereafter. In vitro degradation of dry matter and CP was increased (P<0.001) in non-extracted silages but that of neutral detergent fiber was increased (P<0.001) in extracted ones without difference among silages. Difference in mean values of degradability for each silage prior to- and post extraction with borate buffer, however, was not found among silages. It may be concluded that high NPN content of silages may reduce the protein availability in silages and borate buffer soluble components in silages can stimulate the early stage of fermentation.