SiAlON ceramics are used as ceramic cutting tools for heat-resistant super alloys (HRSAs) due to their excellent fracture toughness and thermal properties. They are manufactured from nitride and oxide raw materials. Mixtures of nitrides and oxides are densified via liquid phase sintering by using gas pressure sintering. Rare earth oxides, when used as sintering additives, affect the color and mechanical properties of SiAlON. Moreover, these sintering additives influence the cutting performance. In this study, we have prepared Ybm/3Si12-(m+n)Alm+nOnN16-n (m = 0.5; n = 0.5, 1.0) ceramics and manufactured SiAlON ceramics, which resulted in different colors. In addition, the characteristics of the sintered SiAlON ceramics such as fracture toughness and microstructure have been investigated and results of the cutting test have been analyzed.

파이로프로세싱의 전해환원공정에서 생산된 금속전환체의 조성은 전해정련공정 운전의 중요한 운전변수인 용융염 중 UCl3 의 농도변화에 영향을 미친다. 따라서, 본 연구에서는 금속전환체에 함유된 TRU와 RE 원소의 함량 및 금속전환체에 동반 되어 전해정련 전해조에 유입될 수 있는 Li2O 농도가 전해정련 전해조의 UCl3 농도 변화에 미치는 영향을 검토하였다. 금속 전환체의 TRU 원소와 RE 원소의 농도만을 고려하였을 때 전해정련 운전 batch 수 증가에 따라 UCl3 농도가 감소하였다. 전 해정련 1 campaign(20 batch)를 운전하기 위해서는 UCl3를 3회 이상 추가 보충해야 함을 알 수 있었다. 한편, 금속전환체에 동반되어 전해정련 전해조에 유입되는 Li2O의 유입량 증가에 따라 UCl3 농도 감소의 영향이 크게 나타났으며, 이에 따라 운전 가능 batch 수가 급격히 감소하게 되어 전해정련 운전에 중요한 운전 변수임을 보여주었다. 이러한 결과는 전해정련 운전 중 UCl3 농도 유지를 위해 금속전환체에 포함된 TRU 및 RE 원소뿐만 아니라 금속전환체에 동반되어 유입될 가능성이 있는 Li2O의 영향도 고려하여 전해정련 운전모드를 설정하여야 함을 보여주었다.

In this paper, we investigate to determine quality characteristics, fatty acid composition and cytotoxic effect of extracts and fractions from whole Lycopus lucidus Turcz. roots. Additionally, we evaluated cytotoxic activity against the growth of human fibrosarcoma cells (HT-1080) and human gastric adenocarcinoma (AGS), human colon cancer cell (HT-29) lines using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Acetone+methylene chloride (A+M) and methanol (MeOH) extracts from L. lucidus Turcz. were obtained through solvent extraction. Then we further fractionated both extracts with n-hexane, 85% aq. MeOH, n-butanol (n-BuOH) and water. In fatty acid composition, L. lucidus Turcz. contained 33.2% of 18:1n-9 and 1.81% of 18:3n-3, respectively. The incorporation of treatment with A+M and MeOH extracts and n-hexane, 85% aq. MeOH, n-butanol (n-BuOH) and water fractions dose-dependently increased cytotoxicity against the growth of HT-1080 and AGS, HT-29 cancer cells (p<0.05). The A+M extract had a higher inhibitory effect on the growth of all cancer cells in comparison to MeOH extract. Among the fractions, the 85% aq. MeOH and n-hexane fractions showed a higher inhibitory effect after proliferating the three cancer cells. These results suggest that the 85% aq. MeOH and n-hexane fractions have a potential to inhibit the growth of human cancer cell lines.

본 연구는 평창지역의 산지에서 목초 파종시기가 초지의 연차별 식생 및 생산성에 미치는 영향을 구명하고 평창지역의 산지초지 조성에 적합한 피종시기를 설정하고자 2015년 8월부터 2017년 10월까지 평창군에 위치한 서울대학교 국제농업기술대학원의 산지에서 수행되었다. 처리는 총 4처리로 T1: 8월 13일 파종 T2: 8월 27일 파종, T3: 9월 10일 파종, T4: 9월 24일 파종이었다. 월동 후 초지 식생구성을 보면 T1과 T2까지는 목초 식생비율이 98%이상으로 높은 식생밀도를 보였지만 T3이후부터는 급격하게 감소하였다. 분얼의 경우 T1과 T2에서 4.4개 이상으로 양호하였지만 T3이후에는 급격하게 감소하였다. 이러한 초기 월동률의 차이는 이후 목초의 식생 및 생산성에 큰 영향을 주었다. 연차별 식생변화를 보면 T1과 T2의 경우 목초 비율이 81%이상으로 우수하였지만 T4의 경우 상대적으로 불량하였다. 전체 건물 수량의 경우 T2와 T1이 각각 9,042 kg ha-1 와 8,845 kg-1 로 우수하게 나타났지만 T4의 경우 5,086 kg ha-1 로 건물 생산성이 상대적으로 낮게 나타났다. 결과를 종합해보면 평창지역에서 8월 말까지 파종을 완료 한 경우 목초 월동이 향상되었으며 이는 식생이나 생산성 측면에서 유리하게 나타났다.

This study was conducted to investigate effect of feeding beet pulp on reproductive performance, colostrum composition and microbiological characteristics in sows. A total of 12 sows(Landrace×Yorkshire) were randomly allotted three dietary treatments at gestating 90 days. The diets were prepared by adding 0, 5 and 10% of the beet pulp in basal diets. The pigs fed 5% beet pulp showed higher litter size than the 0 and 10% beet pulp treatments, although there was not significant among the treatments. Similarly, birth and 21days weight in piglet were not different among the treatments. In colostrum fat, protein, lactose, citric acid, solid, ffa, true protein were ranged to reference values, but not difference among the treatments. E.coli of feces was lower(P<0.01) in the 5% beet pulp than the 0 and 10% beet pulp treatments. But no effect was observed on Lactobacilli of feces among dietary treatments. These our results indicate the beet pulp has no significant effect of reproductive performance and colostrum composition in sows. But, 5% level beet pulp is effective for reduction of intestinal pathogenic microorganisms.

The objective of this study was to investigate the suitable method for rapid establishment of grassland according to forage species, mixed pastures and installation of mesh at 35 degree angle of cutting area in the middle region of Korea. In agronomic characteristics after wintering, vegetation coverage of Tall fescue(TF) was 74% in monoculture, which was the highest among 3 forage crops. Meanwhile average vegetation coverages of monoculture and mixed pasture were 67 and 92% in treated of mesh, which were 4 and 18% higher than untreated of mesh, respectively. In botanical composition, TF of monoculture and Orchardgrass(OG) and TF oriented mixed were indicated over 94% forage coverage. Meanwhile forage coverages Kentucky bluegrass(KBG) and Red top(RT) of monoculture and Perennial ryegrass(PRG) oriented mixture were 89, 81 and 92% in treated of mesh, which were 7, 6 and 5% higher than untreated of mesh, respectively. In forage productivity, dry matter yield(DMY) of TF(12,537kg/ha) and KBG(11,897kg/ha) of monoculture were significant(p<0.05) higher than RT(9,604kg/ha). Meanwhile DMY of OG(12,227kg/ha), TF(12,823kg/ha) and PRG(11,871kg/ha) oriented mixed were not significant difference(p>0.05). In forage quality of monoculture, in the first year, crude protein of KBG was 13.6%, which was the highest among 3 forage species. Also neutral detergent fiber(NDF) of TF was 56.5%, which was the lowest among 3 forage species. In mixed pasture, in the second year, NDF and acid detergent fiber of PRG oriented mixed were 56.5 and 34.3%, respectively, which was the lowest among 3 mixed pasture. In conclusion, forage species TF was more suitable on initial rootage and continuous forage coverage, OG and TF oriented mixed were more suitable on continuous forage coverage. Also the installation of mesh showed positive effects on initial rootage and maintain forage ratio.

This experiment was carried out to determine the effect of organic fertilizer and seed mixture on productivity, botanical composition and forage quality in middle areas(Geumsan, 250m sea level) pasture. Total six experimental pastures (orchardgrass, timothy and tall fescue based seed mixture and with or without organic fertilizer) were established in autumn, 2014 and evaluated productivity and agronomic characteristics from 2015 to 2016. Plant heigh was higher in orchardgrass based mixture and orchardgrass and tall fescue based mixture were higher in 2nd harvest. There was not found the significant difference among treatment(P<0.05) in dry matter (DM) content. Botanical composition in 1st harvest was higher weed portion in orchardgrass based mixture and legumes was disappeared at 3rd harvest in all treatments. Fresh and dry matter yield was higher in 2nd year than 1st year. In 1st year, orchardgrass based mixture with organic fertilizer plot was the highest(P<0.05) DM yield, but tall fescue based mixture with organic fertilizer was the highest in 2nd year. Content of crude protein (CP) was the highest in tall fescue based mixture and Timothy based mixture showed low in ADF (acid detergent fiber) and NDF (neutral detergent fiber) content. But the content if in virto dry matter digestibility was higher than others. In 2nd year, the nutritive value of 2nd and 4th harvested grasses were higher and average RFV (relative feed value) value was the highest at 4th harvest. According to this result, orchardgrass and tall fescue based mixture would be recommendable for farm who considering productivity and timothy based mixture would be recommendable for considering forage quality in middle areas of Korea.