• 제목/요약/키워드: liquid paraffin

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金屬이온結合性 高分子킬레이트에 關한 硏究 (Studies on Polymer Chelates Binding with Metallic Ions)

  • 최규석;신세건;최길현;김문걸
    • 대한화학회지
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    • 제21권1호
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    • pp.60-66
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    • 1977
  • m-Phenylenediamine(以下 MPD로 略함)과 resorcinol(以下 RES로 略함)을 몰比를 달리하면서 포름알데히드와 酸化觸媒 존재하에서 反應시켜 生成되는 附加共縮合型 樹脂를 流動파라핀을 사용하여 서스펜젼重合시켜 60∼80 mesh의 粒狀重合體를 合成하고 이를 精製한후 5, 10, 15, 20, $25{\%}$의 水酸化 나트륨 水溶液으로 처리한후, 原樹脂와 이들 알칼리 處理樹脂의 金屬이온들에 대한 吸着性을 檢討하였다. $Cd^{2+}$이온에 대한 흡착성은 原樹脂보다 水酸化나트륨水溶液을 처리한 경우 현저히 吸着性은 向上되지만 MPD : RES의 몰比 가 增加함에 따라 原樹脂의 경우와는 달리 減少하는 경향을 나타내며 $Pb^{2+}와\;Al^{3+}$이온들은 알칼리처리로 吸着能增加와 더불어 MPD : RES의 몰比가 2 : 1에서 最大値를 나타내며 $Ca^{2+}$이온의 경우는 MPD : RES의 몰比가 1 : 1에서 최대치를 나타내고 있다. $Mg^{2+}과\;Co^{2+}$이온들은 거의 類似한 傾向을 나타내어 MPD : RES의 몰比增加와 더불어 吸着能은 減少하는 傾向을 나타낸다. $Hg^{2+}$이온의 경우는 特異하며 MPD : RES의 몰比가 減少함에 따라 吸着能은 현저히 增加하는 경향을 나타내어 窒素含宥킬레이트와의 結合性이 强한 一般性과 잘 一致하고 있다. 이 系의 樹脂들은 輕金屬 이온(例 $Ca^{2+},\;Mg^{2+}$) 들보다 重金屬이온(例 $Cd^{2+},\;Hg^{2+}$)들에 對한 吸着力이 현저히 優秀하다.

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Comparison of carcass and meat quality traits between lean and fat Pekin ducks

  • Ding, Si-Ran;Li, Guang-Sheng;Chen, Si-Rui;Zhu, Feng;Hao, Jin-Ping;Yang, Fang-Xi;Hou, Zhuo-Cheng
    • Animal Bioscience
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    • 제34권7호
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    • pp.1193-1201
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    • 2021
  • Objective: According to market demand, meat duck breeding mainly includes 2 breeding directions: lean Pekin duck (LPD) and fat Pekin duck (FPD). The aim of the present study was to compare carcass and meat quality traits between 2 strains, and to provide basic data for guidelines of processing and meat quality improvement. Methods: A total of 62 female Pekin ducks (32 LPDs and 30 FPDs) were slaughtered at the age of 42 days. The live body weight and carcass traits were measured and calculated. Physical properties of breast muscle were determined by texture analyzer and muscle fibers were measured by paraffin sections. The content of inosine monophosphate (IMP), intramuscular fat (IMF) and fatty acids composition were measured by high-performance liquid chromatography, Soxhlet extraction method and automated gas chromatography respectively. Results: The results showed that the bodyweight of LPDs was higher than that of FPDs. FPDs were significantly higher than LPDs in subcutaneous fat thickness, subcutaneous fat weight, subcutaneous fat percentage, abdominal fat percentage and abdominal fat shear force (p<0.01). LPDs were significantly higher than FPDs in breast muscle thickness, breast muscle weight, breast muscle rate and breast muscle shear force (p<0.01). The muscle fiber average area and fiber diameter of LPDs were significantly higher than those of FPDs (p<0.01). The muscle fiber density of LPDs was significantly lower than that of FPDs (p<0.01). The IMF of LPDs in the breast muscle was significantly higher than that in the FPDs (p<0.01). There was no significant difference between the 2 strains in IMP content (p>0.05). The polyunsaturated fatty acid content of LPDs was significantly higher than that of FPDs (p<0.01), and FPDs had higher saturated fatty acid and monounsaturated fatty acid levels (p<0.05). Conclusion: Long-term breeding work resulted in vast differences between the two strains Pekin ducks. This study provides a reference for differences between LPD and FPD that manifest as a result of long-term selection.