Post-uniform elongation and tensile fracture mechanisms of Fe-18Mn-0.6C-xAl twinning-induced plasticity steels

Yu, Ha-Young,Lee, Sang-Min,Nam, Jae-Hoon,Lee, Seung-Joon,Fabrè,gue, Damien,Park, Myeong-heom,Tsuji, Nobuhiro,Lee, Young-Kook Elsevier 2017 Acta materialia Vol.131 No.-

<P>The objective of the present study was to elucidate the complicated interrelationship between necking, post-uniform elongation (e(pu)), strain rate sensitivity (SRS), fracture mechanism and Al concentration in Fe-18Mn-0.6C-xAl twinning-induced plasticity steels. Many tensile tests were conducted for in- and ex situ observations of necking, fracture surfaces, crack propagation and the density and size of micro-voids with the assistance of a high-speed camera and X-ray tomographic equipment. The addition of Al increased epu, SRS and reduction ratios in dimension of the neck part of tensile specimens, and also changed fracture mode from quasi-cleavage to ductile fracture at the edge part. The quasi-cleavage surface of Al-free specimen was induced by edge and side cracks occurring along grain boundary junctions and twin boundaries within the edges and side surfaces where local deformation bands meet. The ductile-fracture surface of 1.5 %Al-added specimen was formed by the coalescence of micro-voids. While the side-to-middle crack propagation occurred in Al-free and 1 %Al-added specimens due to side cracks, the middle-to-side crack propagation was observed in 1.5 %Al-added specimen. The Al-free specimen had the larger size of the 20 largest voids compared to the 1.5 %Al-added specimen despite its lower void density and local strain due to the accelerated growth of voids near the tips of side cracks. Evaluating the negligible epu of Al-free specimen by SRS is not deemed to be reasonable due to its inappreciable necking and side cracks. The improvement of epu in 1.5 %Al-added specimen is primarily due to disappearance of edge and side cracks. (C) 2017 Acta Materiali a Inc. Published by Elsevier Ltd. All rights reserved.</P>

Accumulation of Dietary Conjugated Linoleic Acid (CLA) in Silkworm, Bombyx mori

Chung-Gyoo Park,Seck-Jong Kim,Nam-Gue Ha,Bong-Il Choi,Yeong-Lae Ha 한국식품영양과학회 2001 Preventive Nutrition and Food Science Vol.6 No.1

Conjugated linoleic acid (CLA) exhibits potent anti-carcinogenic and other biological activities in several animal models. We report here that dietary CLA, chemically synthesized from corn oil, accumulates in silkworm, Bombyx mori, which is used as a therapeutic agent for diabetes in Korea and Japan. Mulberry leaves treated with 0.1 or 10% CLA in ethanol were supplied to silkworms from the end of the 3rd instar to the 3rd day of the 5th instar. Fresh mulberry leaves or leaves treated with 10% corn oil in ethanol were fed as a check treatment. The amount of total lipids in the larval body ranged from 17.4 to 19.1 ㎎/g of body tissue, which was not significantly affected by the source of the diets. No CLA was found in the control silkworms. But the level of CLA significantly increased to 83.5 ㎎/g of fat, when fed with mulberry leaves treated with 10% CLA. Only trace amounts of CLA were detected in the larvae reared with check leaves and 0.1% CLA-treated leaves. Mulberry leaves treated with corn oil or CLA were not palatable to the larvae, resulting in a reduction of larval weight. These results suggest that silkworms containing CLA in body lipids could be produced by dietary CLA.

Accumulation of Dietary Conjugated Linoleic Acid (CLA) in Silkworm, Bombyx mori

Park, Chung-Gyoo,Kim, Seck-Jong,Ha, Nam-Gue,Park, Bong-Il,Ha, Yeong-Lae The Korean Society of Food Science and Nutrition 2001 Preventive Nutrition and Food Science Vol.6 No.1

Conjugated linoleic acid (CLA) exhibits potent anti-carcinogenic and other biological activities in several animal models. We report here that dietary CLA, chemically synthesized from corn oil, accumulates I silkworm, Bombyx mori, which is used as therapeutic agent for diabetes in Korea and Japan. Mulberry leaves treated with 0.1 or 10% CLA in ethanol were supplied to silkworms from the end of 3rd instar to the 3rd day of the 5th instar. Fresh mulberry leaves or leaves treated with 10% corn oil in ethanol were fed as a check treatment. the amount of total lipids in the larval body ranged from 17.4 to 19.1mg/g of body tissue, which was not significantly affected by the source of the diets. No CLA was found in the control silkworms. But the level of CLA significantly increased to 83.5 mg/g of fat, when fed with mulberry leaves treated with 10% CLA. Only trace amounts of CLA were detected in the larvae reared with check leaves and 0.1% CLA-treated leaves. Mulberry leaves treatd with corn oil or CLA were not palatable to the larvae, resulting in a reduction of larval weight. These results suggest that silkworms containing CLA in body lipids could be producted by dietary CLA.

雜蠶 人工飼料育 및 桑葉育 飼育에 關한 硏究

崔周鎬,文炳圓,河南圭 진주산업대학교 농업기술연구소 1994 農業技術硏究所報 Vol.7 No.-

晋州産業大學校 有蠶實驗室에서 1993年 8月부터 10月까지 大成蠶, 富農蠶, 白屋蠶을 供試品種으로 하여 稚蠶 人工飼料育 및 桑葉育에 의한 生育 및 收量을 比較 究明하고자 本 試驗을 實施하여 그 結果를 要約하면 다음과 같다. 1. 經過日數는 人工飼料育에서 桑葉育보다 2일 程度 길었다. 2. 人工飼料育에 비하여 桑葉育이 1萬頭 收繭量은 1.2∼2.8kg 程度 많았으며, 1ℓ當 고치의 數는 桑葉育에서 4∼8個 程度, 品種間에는 富農蠶이 적은 傾向이었다. 3. 全繭重 및 繭層重은 桑葉育에서 무거운 傾向이었으며, 繭層比率은 비슷한 傾向이었으나 白玉蠶은 桑葉育에 비하여 人工飼料育에서 낮았다. 4. 繭長 및 繭幅은 암·수 共히 桑葉育에서 길거나 넓었다. 5. 화용비율은 人工飼料育에서 높았으며, 品種間에 있어서는 白玉蠶이 높은 傾向이었다. The purpose of this study is to examine the growth and the cocoon yield of the artificial diet group and the mulberry leaf diet group. The subjects of experiment were Te-sung-jam, Bu-nong-jam and Peck-ock-jam. The study was conducted from August to October, 1993 in the Jam-breeding plot of Chinju National University. 1. The larva progression term of the artificial diet group was 2 days longer than the mulberry leaf diet group. 2. The 20,000 head cocoon yield of the mulberry leaf diet group was larger than that of the artificial diet group. The number of cocoon in the mulberry leaf diet group was 4-8. Bu-nong-jam tended to be relatively small. 3. The cocoon weight and cocoon layer weight tended to be heavier in the mulberry leaf diet plot. The percentage of cocoon layer weight was almost the same, but the artificial diet group was lower than that of the mulberry leaf diet in Peck-ock-jam. 4. The cocoon length and width of both was longer and wider than those of the others. 5. The paration rate of both was longer and wider than that of the others. 6. The paration rate of the artificial diet group was high, of the three jams. Peck-ock-jam tended to be high.

누에의 齡別 人工飼料飼育에 관한 性狀比較試驗

崔周鎬,文柄圓,河南圭 진주산업대학교 농업기술연구소 1995 農業技術硏究所報 Vol.8 No.-

1994年 8月부터 9月까지 白玉蠶, 大成蠶을 供試品種으로하여 누에의 齡別 人工飼料育에 의한 生育 및 數量을 比較 糾明하고자 본 試驗을 實施하여 그 結果를 要約하면 다음과 같다. 1. 經過日數에 있어서 壯蠶期의 葉質不良으로 因하여 全齡 人工飼料育의 5齡 經過日數가 1日 5時間 짧았으며 全齡經過에서도 4時間 程度 짧았다. 2. 化용比率에 있어서는 人工飼料에 의한 飼育期間이 길수록 높아 人工 飼料에 의한 飼育에서 蠶作이 安定되었다. 3. 全繭重은 人工飼料에 의한 飼育期間이 길수록 가벼운 傾向이었으나 특히 全齡 人工飼料育에 比하여 4齡 人工飼料育에 있어서 顯著하게 낮았다. 4. 單繭重에 있어서는 人工飼料飼育 期間이 길수록 가벼운 傾向으로 全齡 人工飼料育에 있어서 顯著하게 낮았다. 5. 繭層比率에 있어서도 人工飼料에 의한 飼育期間이 길수록 낮은 傾向이었다. The purpose of this experiment the growth and yield of cocoons bred by artificial feed at each instar period. The period of experiment was from August until September 1994. And the experimental subjects were Paekok-jam and Taesung-jam. The results obtained are as follows: As to the number of passage days, because of the bad quality of mulberry leaf, the number of the fifth-instar-period passage days was 1 day and 5 hours short in the artificial-feed bred cocoon at total instar period. The total-instar-period passage was also 4 hours short. The pupation rate was higher according as the artificial-feed-breeding period was long. So the artificial feed enabled more stable cocoon breeding. The total cocoon weight was lighter according as the artificial-feed-bred period was long. Especially, it was markedly light in the fourth-instar-period artificial-feed-bred cocoons. The silk weight was lighter according as the artificial-feed-bred period was long. And it was outstandingly light in the total-instar-period artificial-feed-bred cocoons. The percentage of cocoon layer weight was also lower according as the artificial-feed-bred period was long.

Accumulation of Dietary Conjugated Linoleic Acid (CLA) in Silkworm, Bombyx mori

Choi Bong-Il,Park Chung-Gyoo,Kim Seck-Jong,Ha Nam-Gue,Ha Yeong-Lae 한국응용곤충학회 2000 한국응용곤충학회 학술대회논문집 Vol.2000 No.1