슈퍼오스테나이트계 스테인리스강 GTA 용접부의 용접 적층 및 입열에 따른 공식 부식 특성

고대환(Dae-Hwan Ko),박영일(Young-Il. Park),신용택(Yong-Taek Shin) 대한용접·접합학회 2020 대한용접·접합학회지 Vol.38 No.6

This study investigated the corrosion characteristics of weldments on superaustenitic stainless steels for various heat inputs and numbers of welding passes during gas tungsten arc welding(GTAW). The heat input was changed to 0.7 or 1.4 kJ/mm and the weldment microstructure and chemical composition were analyzed. The weldment corrosion resistance was evaluated by potentiodynamic polarization, and the critical pitting temperature (CPT) was determined. The CPT dropped from 85 to 55 ℃ with both increasing heat input and number of welding passes. The microstructural and chemical compositional analyses revealed that the Mo segregated and precipitated in the interdendritic region, and that the Mo content in the dendritic core was lower than that in the surrounding area. The Mo content decreased when the pitting corrosion initiated. The precipitate content and dendrite core size both increased, and the pitting corrosion resistance decreased with both increasing heat input and number of welding passes.

산간지방 야초(野草) 및 잡관목(雜灌木)의 사료화에 관한 연구

맹원재,최일,이순복,고대환 한국낙농학회 1989 韓國酪農學會誌 Vol.11 No.4

본 실험은 산간지대에서 생육하는 아카시아, 싸리 및 칡을 시기별로 1987년 6월 8일부터 10월 12일까지 10회 예취하여 암모니아 gas를 건물 기준으로 0, 2, 4, 6% 처리하여 시료로 사용하였다. 분석항목은 in vitro 건물 소화율, 에너지 함량 평가 등으로 산야초의 반추가축조사료원으로서의 가치를 규명하기 위해서 실시하였으며 실험결과는 아래와 같다. 1. 전체 평균 조단백질 함량은 아카시아, 싸리 및 칡이 각각 21.93, 20.54, 20.38%로 별 차이가 없었으며, 조지방 함량은 아카시아에 있어 5차 예취까지는 점진적으로 증가하는 경향이었으나 싸리 및 칡에 있어서는 일관성 있는 변화를 볼 구 없었다. 조섬유 함량은 전체적으로 4차 예취시까지는 증가하는 경향이었고, 칡에서 19.57%로 가장 높았다. 2. NDF 함량은 각 산야초간에 큰 차이가 없었고, ADF 함량은 싸리가 다소 높은 경향이었다. Cellulose함량은 칡이 17.35%로 아카시아와 싸리보다 높았고, NDS 함량도 같은 추세였다. Hemicellulose 함량은 아카시아가 다소 높았다. 3. In vitro 건물 소화율은 전체적으로 암모니아 처리 수준에 따른 변화는 없었고, 각 처리구에서 공히 아카시아, 싸리, 칡 순으로 소화율이 높은 경향이었다. 4. 에너지 함량은 5차 예취시까지는 증가하다가 그후로는 감소하는 경향이었고, TDN(%), DE(Kcal/g), ME(Kcal/g) 각각 아카시아, 싸리, 칡 순으로 높았다. The change of the chemical components, dry matter digestibilities and energy value of wild legumes treated with anhydrous ammonia (Robinia pseudo acacia, Lespedeza bicolor, Pueria thunbergiana) grown in the mountainous area, Kangwon-do province was determined by the advanced stage of maturity (1987. 6.8 - 1987. 10.12) divided by 10 cutting times. Samples were dried at 70℃ for 24 hr. and ground to pass a 1 mm screen. The results obtained were as follows: 1. The crude protein of wild legumes were ranged 20.38% - 21.93% and had not a difference among the legumes. The crude fat content with Robinia pseudo acacia was linearlyincreased by 5th stage of maturity, but no change was observed with the others. The highest content of crude fiber (19.57%) was observed with Pueria thunberginana. 2. The NDF were not different among the wild legumes and ADF content of Lespedeza bicolor were slightly higher than the other legumes. Cellulose with Pueria thunbergiana (17.35%) were also higher than the others and NDS had a similiar tendency. Hemicellulose with Robinia pseudo acacia were slightly higher than the other wild legumes. 3. The in vitro dry matter digestibilities were not differentiated by the level of anhydrous ammonia treatment. Overall means of digestibilities were increased by Robinia pseudo acacia, Lespedeza bicolor, Pueria thunbergiana, orderly. 4. The energy values were increased by 5th stage of maturity and then decreased by until 10th stage. TDN(%), DE(Kcal/g), and ME(Kcal/g) were increased by Robinia pseudo acacia, Lespedeza bicolor, Pueria thunbergiana, orderly.

부존(賦存) 사료자원 활용에 관한 연구 : I. 옥수수대의 사료가치 증진 방안 I. Nutritive Value of Corn Stover

맹원재,최일,이순복,장문백,고대환 한국낙농학회 1990 韓國酪農學會誌 Vol.12 No.3

옥수수대는 lignin含量이 낮고 粗蛋白質 含量이 높으며 可消化 營養素 總量도 고간류에 비해 높다. 또한 옥수수대의 效率的 利用은 부족한 조사료의 확보와 더불어 農家副産物의 活用이라는 測面에서도 매우 重要한 課題이다. 따라서 本 實驗은 암모니아 및 알칼리를 處理하여 蛋白質 含量을 增加시키거나 消化率을 높이고, 鷄糞을 處理하여 사일리지로 제조하여 사료로 이용시 옥수수대에 不足한 營養素 供給 및 利用 效果를 糾明하고자 實施하였다. 1. 無處理 corn stover에 비해 ammonia處理時는 粗蛋白質 含量이 約 2.5倍 增加되었다. 그 외의 處理區에서는 粗蛋白質 含量 變化에 있어 큰 差異를 나타내지 않았다. 2. NDF含量은 ammonia處理와 鷄糞處理 사일리지에서 他 處理區보다 낮은 수준을 보여주었다. ADF含量은 無處理와 알칼리 處理區 間에는 差異가 없었고, 鷄糞處理 사일리지區와 ammonia處理區 보다는 높은 傾向을 나타내었다. Cellulose 含量은 ammonia 處理時에 가장 높았고, 鷄糞處理 사일리지區에서 다른 처리보다 낮은 水準을 나타내었다. 3. NDS(Neutral Detergent Soluble) 含量은 ammonia處理 corn stover와 鷄糞處理 사일리지區에서 높았으며, hamicallulose含量은 옥수수 사일리지區에서 가장 높은 수준을 보여주었다. 4. 乾物 消化率은 알칼리 處理와 ammonia 處理時에 가장 높았으며, 粗蛋白質 消化率은 ammonia 處理와 鷄糞을 添加한 區에서 높은 水準을 보여주었다(P<0.05). NDF 消化率은 알칼리 處理와 옥수수 사일리지區가 無處理와 ammonia 處理, 그리고 鷄糞處理區보다 多小 높은 傾向을 보여주었다. ADF 消化率은 ammonia 및 鷄糞添加區가 다른 區에 비해서 多小 떨어짐을 나타내었다. Cellulose消化率은 各區間에 큰 차이를 나타내지는 않았으나, 알칼리 處理區와 옥수수 사일리지에서 多小 높은 趨勢였다. 5. TDN 含量은 알칼리 및 ammonia處理 corn stover에서 他處理區보다 約 10% 정도 높았으며, DE價와 ME價도 알칼리 및 ammonia 處理 corn stover에서 類似한 傾向을 보여 주었다. Corn stover contains relatively lower lignin than other crop residues, but is high in crude protein and total digestible nutrients. And improving the nutritive value of corn stover is very important work on security of roughage and practical use of agricultural by-products as ruminant feed. Therefore, this experiment was conducted to study the effect of ammonia, alkali and poultry manure treatment of corn stover on change of chemical composition, in vitro digestibility and energy content. The results obtained were as follows: 1. The crude protein content of ammonia treated corn stover was 2.5 times higher than untreated corn stover, but no difference was observed with the others. 2. The NDF content of ammonia and poultry manure treated corn stover-were lower than the others. The ADF content were not different between the untreated and alkali treated corn stover, and lower value were observed with poultry manure and ammonia treatments. The highest content of cellulose was observed with ammonia treated corn stover. Cellulose with poultry manure treatment was slightly lower than the others. 3. The higher NDS content were observed with ammonia and poultry manure treatment. The highest content of hemicellulose was observed with corn silage. 4. The highest dry matter and crude protein digestibilities were observed with ammonia treated corn stover (P < 0.05). The NDF digestibilities with alkali treated corn stover and corn silage were slightly higher than ammonia and poultry manure treatments. ADF and cellulose digestibilities with alkali treated corn stover and corn silage were higher than other treatments. 5. TDN with alkali and ammonia treated corn stover were 10% higher than other treatments, and DE and ME value were had a similar tendency.

우 난포란(卵胞卵)의 체외성숙(體外成熟)에 관한 연구 : II. 발정우혈청(發精牛血淸) , 우난포액(牛卵胞液) 및 난구세포(卵丘細胞)가 난포란의 체외성숙과 체외수정(體外受精)에 미치는 영향 II. Effects of Estrus Bovine Serum , Bovine Follicular Fluid and Matured Cumulus Cells on In Vitro Maturation and Fertilization of Follicular Oocytes

윤산현,박세필,박태균,고대환,정길생 한국낙농학회 1989 韓國酪農學會誌 Vol.11 No.3

本 硏究는 發精牛血淸, 牛卵胞液 및 成熟卵丘細胞가 牛卵胞卵의 體外成熟과 體外受精에 미치는 效果를 調査하였으며 그 結果는 다음과 같다. 1. 發精牛血淸 50%와 成熟卵丘細胞를 添加한 m-TALP 培養液에 있어서의 卵胞卵의 成熟率은 63.7%로서 이는 基礎培養液 및 100% 發精牛血淸에 있어서의 成熟率인 40.2% 및 47.3%보다 有意하게(P<0.05) 높았다. 2. m-TALP 培養液에 牛卵胞液 50%와 成熟卵丘細胞을 添加했을 때의 卵胞卵의 成熟率은 70.5%로서 이는 基礎培養液에 있어서의 38.3%나, 100% 牛卵胞液에 있어서의 50.7%보다 有意하게(P<0.05) 높았다. 3. 發精牛血淸이나 牛卵胞液이 添加된 m-TALP 培養液에서 成熟卵丘細胞와 함께 同伴培養에 의해 成熟된 卵胞卵의 體外受精率은 22.3∼43.2%였는데 이 成績은 基礎培養液의 11.6∼17.2%보다 有意하게(P<0.01) 높았으며, 특히 25% 發精牛血淸과 25% 牛卵胞液을 添加한 培養液에서 成熟된 卵胞卵의 體外受精率은 43.2%로서 가장 높았다. These experiments were carried out to investigate the effects of estrus bovine serum(EBS), bovine follicular fluid(BFF) and matured cumulus cells(MCC) on in vitro maturation and fertilization of bovine follicular oocytes. The ovaries and testes were obtained from slaughtered Holstein cow and bulls respectively. The follicular oocytes surrounded with cumulus cells were recovered by aspirating the follicular fluid from the visible follicles of diameter 2-6 ㎜ and the semen were prepared from bull's epididymal cauda. The follicular oocytes were cultured in m-TALP medium containing EBS, BFF or/and MCC for 32h in a incubator with 5% CO_2 in air at 38℃, and then matured oocytes were again cultured for 24h, with 5×10^5/㎖ motile sperm capacitated in the BO medium containing 5㎎/㎖ BSA and 2.5㎜ caffein. The results obtained in these experiments were summarized as follow: 1. The maturation rate of the follicular oocytes, 63.7%, obtained from the m-TALP medium supplemented with 50% EBS and MCC was significantly higher (P<0.05) than that from basic medium (40.2%) or from 100% EBS medium (47.3%). 2. The maturation rate of the follicular oocytes cultured in m-TALP medium supplemented with 50% BFF and MCC was 70.5%. This value was significantly higher (P<0.05) than 38.3% of basic medium or 50.7% of 100% BFF medium. 3. The fertilization rates of the follicular oocytes matured in the m-TALP medium supplemented with EBS, BFF or/and MCC were ranged from 22.3% to 43.2%, and those values were significantly higher (P<0.01) than that of the follicular oocytes matured in basic medium. The highest fertilization rate, 43.2%, was obtained from m-TALP medium supplemented with EBS and BFF by 25% respectively.