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축산식품중(畜産食品中)의 Cholestrerol에 관(關)한 고찰(考察)

  • Han, Seok-Hyeon
    • Proceedings of the Korean Society for Food Science of Animal Resources Conference
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    • 1995.11a
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    • pp.1-48
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    • 1995
  • 식생활은 인간 생활의 주체이고 먹는다는 것은 그 수단이다. 그중 중요한 하나의 명제는 인간이 놓여진 여러 환경에서 어떻게 건강을 유지하고 그 개체가 소유하고 있는 능력을 최대치까지 생리적으로 성장 발전시킴과 동시에 최대한 수명을 연장시키기 위한 식물 섭취방법을 마이크로 레벨까지 해명하는데 있다. 인간은 일생동안 엄청난 양의 음식물을 먹는다(70세 수명일 경우 200만 파운드 즉 체중의 1,400배). 그러나 먹기는 먹되 자신의 건강과 장수를 위하여 어떤 음식을 어떻게 선택하여 어떻게 먹어야 하는 문제가 매우 중요하다. 최근 우리나라도 국민 소득이 늘면서 식생활은 서구화 경향으로 기우는 듯하다. 공해를 비롯한 수입식품 등 여러 가지 문제점이 제기됨에 따라 자연식과 건강식을 주장하는 소리가 높이 일고 있다. 그중에는 축산 식품이 콜레스테롤 함량이 다른 식품에 비하여 높게 함유하고 있다는 것으로 심혈관질환의 주범인양 무차별 강조하는 나머지 육식공포 내지는 계란 등의 혐오감 마저 불러 일으키는 경향까지 있는 듯하다. 따라서 본논고에서는 축산식품중의 콜레스테롤 함량수준이 과연 성인병의 주범인지 아니면 다른 지방산과 관련해서 올바르게 평가하고 그 문제점과 대책을 개관해 보고 요약하면 다음과 같다. 1. 사람은 유사이래 본능적으로 주변의 식물이나 동물의 고기를 먹고 성장하여 자손을 증식시키고 어느 사이에 늙으면 죽음을 맞이 하는 싸이클을 반복하면서 기나긴 세월동안 진화를 하여 오늘날의 인간으로서의 자태를 이루었다. 유인원과 같은 인류의 선조들은 수렵을 통해 육식을 많이 하였을 것이므로 인간은 원래 육식동물이 아닐까? 구석기시대의 유물을 보면 많은 뼈가 출토되고 “얄타미라”나 “라스코” 동굴벽화가 선명하게 묘사되고 있다. 2. 우리나라 선조 승구족의 일파가 백두산을 비롯한 만주 송화강 유역에 유입되면서 수렵과 목축을 주요 식품획득의 수단으로 식품문화권을 형성하면서 남하하여 한반도 민족의 조상인 맥족(貊族)으로 맥적(貊炙)이라고 하는 요리(오늘날의 불고기)를 먹었다는 기록이 있다. 3. 인간의 수명을 1900년대로 거슬러 올라가서 뉴질랜드가 세계최장수국(호주는 2위)로서 평균수명은 남자 58세, 여자 69세인 반면 일본과 한국은 당시 남자 36세, 여자 37세이던 것이 일본은 1989년에 이르러 세계 최장수국으로 등장했으나 1990년 당시 뉴질랜드${\cdot}$호주 등은 목축 및 밀(小麥) 생산국가였기 때문이라는 것과 일본은 오늘날 합리적인 식생활 국가라는 것을 간과해서는 안된다. 4. 우리나라 10대 사망원인중 (1994년도) 뇌혈관질환이 1위, 교통사고 2위, 암이 3위 순위로서 연령별로는 10~30대의 불의의 사고(교통사고), 40~60대는 암, 70대 이상은 뇌혈관질환이 가장 많다. 구미${\cdot}$일 7개국 정상국가들은 심질환 사망이 가장 높다. 5. 식생활의 변화에 있어서 우리나라는 주식으로 섭취해 왔던 곡류는 70년 대비 94년에는 0.7배 감소된 반면 육류 5배, 계란 2.4배, 우유는 무려 29.3배 증가되었다. 식생활 패턴이 서구화 경향으로 바뀌는 것 같다. 6. 71년도 우리나라의 지질섭취량은 국민 1인당 1일 평균 13.1g에 섭취에너지의 5.7%수준이었으나 92년도에는 34.5g으로서 총에너지 섭취량의 16.6%에 달하고 총섭취 지방질중 동물성 섭취 비율은 47%를 차지 한다. 국민 평균 혈청콜레스테롤 농도는 80년에 비해 88년에는 11%가 증가되었고 80년에 210mg/dl 이상 되는 콜레스테롤 혈증인 사람의 비율이 5%에서 88년에는 23%로 크게 증가했다. 7. 세계 정상국가들의 단백질 즉 축산식품의 섭취는 우리나라보다 적게는 2배, 많게는 6~7배 더 섭취하고 90년도 우리나라의 지질섭취량은 일본의 1/3수준에 불과하다. 8. 콜레스테롤은 인체를 비롯한 모든 동물체에 필수적으로 분포하고 있는 것으로 체내 존재하고 있는 총량은 90~150g, 이중 혈청콜레스테롤은 4%(6g)를 차지하고 있음에도 불구하고 이 아주 적은 콜레스테롤에 일희일비(一喜一悲) 논쟁은 60~70년 끄러오고 있다. 9. 콜레스테롤의 생체내 기능으로서는 (1) 세포벽의 지지물질 (2) 신경세포 보호막물질 (3) 담즙산의 합성 (4) 비타민 D의 합성 (5) 임신시에 반듯이 필요한 분자 (6) 기타 여러 가지 기능을 수행하는 것으로 필수적인 물질이다. 10. 우리가 식이를 통해서 섭취 콜레스테롤을 550mg정도를 섭취한다고 하더라도 이 정도의 양은 배설 소모되는 양과 거의 맞먹는 양이다. 피부와 땀샘에서 소실되는 양만도 100~300mg에 달하기 때문에 미국농무성에서 섭취량을 300mg로 제한하는 것은 무의미하다. 11. 콜레스테롤 운반체로서의 지단백질은 그 밀도가 낮은 것으로부터 킬로미크론(chylomicron), 초저밀도 지단백질(VLDL), 저밀도 지단백질(LDL) 및 고밀도 지단백질(HDL)으로 나누는데 LDL은 혈청콜레스테롤 중 약 70%, HDL은 약20%를 함유한다. 12. 혈중 콜레스테롤 수준에 영향을 미치는 요인을 열거하여 보면 다음과 같다. 1) 음식을 통해서 섭취되는 콜레스테롤 중 단지 10~40%정도가 흡수되고, 체내에서 합성되는 콜레스테롤이 증가할수록 식이콜레스테롤은 실제 혈청콜레스테롤 수준에 거의 영향을 미치지 않으므로 식이중함량에 대하여 공포를 느끼고 기피할 필요가 없다. 2) 고도불포화지방산, 단가불포화지방산, 포화지방산의 비 즉 P/M/S의 비가 균형되도록 권장한다. 3) 동맥경화를 비롯한 성인병의 원인이 되는 혈전증에는 EPA의 양을 높여줌으로서 성인병을 예방할 수 있다. 4) 오메가6지방산 아라키도닉산과 오메가3지방산인 EPA로 유도되는 에이코사에노이드 또는 프로스타노이드는 오메가6와 3지방산을 전구체로 하여 생합성되는 중요한 생리활성 물질이다. 5) 사람은 일반적으로 20세에서 60세까지 나이를 먹어감에 따라 혈중 콜레스테롤 수준이 증가하고 60세 이후부터는 일정한 수준을 유지하며 심장보호성 HDL-콜레스테롤은 감소하는 반면에 죽상경화성 LDL콜레스테롤은 증가한다. 6) 높은 HDL콜레스테롤 수준이 심장병 발생 위험요인을 감소시키는 기능을 갖고 있기 때문에 좋은 HDL이라 부르고, LDL은 나쁜 콜레스테롤이라 부르기도 하는데, 이것은 유전적 요인보다도 환경적 요인이 보다 큰 영향을 미친다. 7) 이것은 생활 형태와 영양섭취상태를 포함해서 개인적 생활패턴에 영향을 받는다. 8) 많은 실험에서 혈중 콜레스테롤 상승은 노년의 가령(加齡)에 적응하기 위한 자연적 또는 생리적인 세포의 생화학적이고 대사적인 기능을 위해 필수적일 수 있다는 것을 간과해서는 안될 것이다. 이 점으로 미루어 노년의 여성들을 위한 콜레스테롤 농도를 200mg/dl이 가장 알맞은 양이 아닌 듯하다. 9) 스트레스는 두가지 모양으로 유발되는데 해로은 스트레스(negative), 이로운 스트레스(positive)로서 긴장완화는 혈중 콜레스테롤 농도를 10% 떨어진다. 10) 자주 운동을 하는 사람들은 혈중 HDL콜레스테롤치가 운동을 하지 않는 사람보다 높다. 육체적인 운동의 정도와 혈중 HDL콜레스테롤 농도와는 정비례한다. 11) 흡연은 지방을 흡착시키므로 혈전증의 원이이 되며 혈관속의 HDL농도를 감소시킨다. 12) 에너지의 과잉섭취에 의한 체중 증가느 일반적으로 지단백질대사에 영향을 미치고, 간에서는 콜레스테롤 과잉 생산과 더불어 VLDL콜레스테롤의 LDL콜레스테롤 혈증을 나타냄으로 운동과 더불어 비만이 되지 않도록 하여야 한다. 13. 콜레스테롤 함량에 대한 조절기술 1) 식품의 우열을 평가할 때 단순히 동물성 또는 식물성 식품으로 분류해서 총괄적으로 논한다는 것은 지양되어야 한다. 이것은 그 식품에 함유하고 있는 지방산의 종류에 따라서 다르기 때문이다. 2) 인체의 원할한 기능 유지를 위해서는 P /M /S비율 뿐만 아니라 섭취 지방질의 오메가6 /오메가3계 지방산의 비율이 모두 적절한 범위에 있어야 하며 한두가지 지방산만이 과량일 때는 또 다른 불균형을 일으킬 수 있다는 점을 알아야 한다. 3) 닭고기는 오메가6지방산 함량을 높이기 위하여 사료중에 등푸른 생선이나 어분이나 어유를 첨가하여 닭고기는 첨가수준에 따라 증가됨을 알 수 있다. 4) 오늘날 계란내의 지방산 조성을 변화시켜 난황내의 오메가 3계열 지방산 함량을 증가시킨 계란의 개발이 활발해졌다. 14. 계란 콜레스테롤에 대한 소비자들의 부정적 인식을 불식시키고자 계란의 클레스테롤 함량을 낮추는 과제가 등장하면서 그 기술개발이 여러모로 시도되고 있으나 아직 실용 단계에 이르지 못했다. 15. 계란의 콜레스테롤 문제에 대한 대책으로서 난황의 크기를 감소시키는 방법에 대한 연구도 필요하다. 16. 계란 중 콜레스테롤 함량 분석치는 표현 방식에 따라서 소비자들을 혼란시킬 가능성이 있다. 또한 과거에는 비색법으로 분석했으나 오늘날은 효소법으로 분석하면 분석치에 상당한 차이가 있다. 17. 소비자의 요구를 만족시키고 버터 소비를 촉진시키기 위해 콜레스테롤을 감소시키는 물리적${\cdot}$생물학적 방식이 제안되어 있으나 현장적용이 가능한 것은 아직 없다. 18. 우리나라에서 이미 시판되고 있는 DHA우유가 선보였고 무콜레스테롤 버터의 경우 트란스(trans)형 지방산에 관해서는 논란의 여지가 많을 것이다. 끝으로 국가 목표의 하나는 복지사회 건설에 있고 복지국가 실현에는 국민 기본 욕망의 하나인 식생활 합리화가 선행되어야 한다. 소득이 늘고 국가가 발전해감에 따라 영양식${\cdot}$건강식 및 기호식을 추구하게 됨을 매우 당연한 추세라 하겠다. 우리의 식생활이 날로 향상되어 지난날의 당질 위주에서 점차 축산물쪽으로 질적 개선이 이루어진다는 것은 고무적임에 틀림없다. 이 축산물을 통한 풍요로운 식의 문화를 창출하면서 건강과 장수 그리고 후손에 이르기까지 번영하고 국가 경쟁력 강화에 심혈을 기우려야 할 때이다.

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Tetralogy of Fallot Associated with Pulmonary Atresia and Major Aortopulmonary Collateral Arteries -Comparison between the different surgical approaches- (폐동맥폐쇄와 주대동맥폐동맥혈관부행지를 동반한 활로씨사징증 -다양한 외과적 치료접근의 비교-)

  • 이정렬;양지혁;김용진;노준량
    • Journal of Chest Surgery
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    • v.32 no.5
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    • pp.471-479
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    • 1999
  • Background: Patients with tetralogy of Fallot(TOF), pulmonary atresia(PA) and major aortopulmonary collateral arteries(MAPCAs) have been managed by heterogenous surgical strategies. We have taken 5 different surgical approaches to this lesion. In this study, relative advantages and disadvantages of each strategy were discussed by analyzing our surgical results. Material and Method: Between January 1986 and June 1998, 50 patients aged 1 to 177(39${\pm}$31) months at a various morphologic spectrum of this lesion were treated at our institution. The groups, which were classified according to the initial approaches, consisted of one-stage unifocalization(A-1, n=9), staged unifocalization(A-2, n=11), right ventricle to pulmonary artery connection(RV-PA)(B-1, n=11), one-stage RV-PA plus unifocalization (B-2, n=11), and one-stage definitive repair(C, n=8). Morphologic charateristics, operative mortalities, and probabilities of definitive repair were compared between the groups and the causes of death, complications and the follow-up results were described. Result: Mean ages at the first operation were 57${\pm}$18(A-1), 42${\pm}$48(A-2), 18${\pm}$14(B-1), 52${\pm}$55(B-2), and 32${\pm}$34(C) months (p<0.05). Mean numbers of MAPCAs were least in group C (A-1=4.3${\pm}$1.0, A-2=4.5${\pm}$1.3, B-1=4.1${\pm}$1.9, B-2=4.1${\pm}$1.6, C=3.4${\pm}$1.8 : p<0.05). The ratios of the direct and the indirect MAPCAs in each group were not different between the grousps (A-1=91%/9%, A-2=78%/22%, B-1=80%/20%, B-2=80%/20%, C=81%/19% : p>0.05). Nineteen patients had more than 1 dependent MAPCAs. True pulmonary arteries were not present 13 patients and they were confluent in 29. A total of 101 operations were performed. Operative mortalities of initial procedures were 33%(3/9, A-1), 18%(2/11, A-2), 0%(0/11, B-1), 36%(5/11, B-2) and 13%(1/8, C) (p<0.05). Percentages of the definitive repair among the patients of each group were 22%(2/9, A-1), 18%(2/11, A-2). 45%(5/11, B-1), 27%(4/11, B-2), and 100%(8/8, C)(p<0.05). Hypoxic respiratory and cardiac failure(6), hypoxic encephalopathy(2) and sepsis(4) were the major causes of death. Phrenic nerve palsy occured in 5 patients. Thirty-one patients among the survivals have been followed up for a mean duration of 74${\pm}$42(3-145) months. One and five year actuarial survival rates were 73% and 73 %. Conclusion: In conclusion, Right ventricle to pulmonary artery connection used in patients with TOF/PA/MAPCA as an inital procedure appeared to be highly successful in enhancing the chance of satisfactory definitive repair without the significant surgical risks. One-stage total repair at an ealier age group could be performed safely with the resonable outcomes. Unifocalization approach, whether it was performed in a single stage or in the multiple stages, resulted in the high operative mortality and the lowest chance of definitive repair, however more tailored selection of the patients and the long follow-up is mandatory to prove the usefulness of this approach.

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Analysis of stress distribution of tooth restored with metal-ceramic crown covering abfraction lesion according to its finish line location under occlusal load (금속도재관으로 수복된 Abfraction lesion이 있는 치아에 가해지는 교합력의 응력 분포 분석)

  • Kim, Jee-Hwan;Yoon, Chol-Wook;Kim, Taehyeon;Kim, Han-Sung;Woo, Dae-Gon;Lee, Keun-Woo;Shim, June-Sung
    • The Journal of Korean Academy of Prosthodontics
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    • v.52 no.4
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    • pp.305-311
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    • 2014
  • Purpose: When the full veneer crown was treated in the tooth with abfraction lesion due to various causes, the prognosis of it may be compromised according to the location of the finish line, but there is few study about the location of its buccal finish line. The purpose of this study was to investigate the effect of location of the finish line of the full veneer crown on stress distribution of the tooth with abfraction lesion. Materials and methods: The two dimensional finite element model was developed to express tooth, surrounding tissue and full veneer crown. The stress distribution under eccentric 144 N occlusal load was analyzed using finite element analysis. The location of finish line was set just at the lower border of the lesion (Group 0), 1 mm (Group 1) and 2 mm (Group 2) below the lower border of the lesion. Results: In the Group 0, von Mises stress was concentrated at the finish line and the apex of the lesion. Also, the stress at the bucal finish line propagated to the lingual side. In the Group 1 and Group 2, stress distribution was similar each other. Stress was concentrated at the apex of lesion, but the stress at the buccal finish line did not propagate to the lingual side. That implied decrease of the possibility of horizontal crown fracture. Conclusion: Full veneer crown alleviated the stress concentrated at the apex of the abfraction lesion, when the finish line of full veneer crown was set below the lower border of abfraction lesion.

Evaluation of Dose Change by Using the Deformable Image Registration (DIR) on the Intensity Modulated Radiation Therapy (IMRT) with Glottis Cancer (성문암 세기조절 방사선치료에서 변형영상정합을 이용한 선량변화 평가)

  • Kim, Woo Chul;Min, Chul Kee;Lee, Suk;Choi, Sang Hyoun;Cho, Kwang Hwan;Jung, Jae Hong;Kim, Eun Seog;Yeo, Seung-Gu;Kwon, Soo-Il;Lee, Kil-Dong
    • Progress in Medical Physics
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    • v.25 no.3
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    • pp.167-175
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    • 2014
  • The purpose of this study is to evaluate the variation of the dose which is delivered to the patients with glottis cancer under IMRT (intensity modulated radiation therapy) by using the 3D registration with CBCT (cone beam CT) images and the DIR (deformable image registration) techniques. The CBCT images which were obtained at a one-week interval were reconstructed by using B-spline algorithm in DIR system, and doses were recalculated based on the newly obtained CBCT images. The dose distributions to the tumor and the critical organs were compared with reference. For the change of volume depending on weight at 3 to 5 weeks, there was increased of 1.38~2.04 kg on average. For the body surface depending on weight, there was decreased of 2.1 mm. The dose with transmitted to the carotid since three weeks was increased compared be more than 8.76% planned, and the thyroid gland was decreased to 26.4%. For the physical evaluation factors of the tumor, PITV, TCI, rDHI, mDHI, and CN were decreased to 4.32%, 5.78%, 44.54%, 12.32%, and 7.11%, respectively. Moreover, $D_{max}$, $D_{mean}$, $V_{67.50}$, and $D_{95}$ for PTV were increased or decreased to 2.99%, 1.52%, 5.78%, and 11.94%, respectively. Although there was no change of volume depending on weight, the change of body types occurred, and IMRT with the narrow composure margin sensitively responded to such a changing. For the glottis IMRT, the patient's weight changes should be observed and recorded to evaluate the actual dose distribution by using the DIR techniques, and more the adaptive treatment planning during the treatment course is needed to deliver the accurate dose to the patients.

A study anxiety of mothers who have hospitalized ill children Focusing on the comparison of korean mothers with multicultural family mothers (입원 환아 어머니의 불안에 관한 연구: 한국인 어머니와 다문화가정 어머니 비교를 중심으로)

  • Oh, Jae-Woo;Moon, Young-Sook
    • Journal of Digital Convergence
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    • v.10 no.6
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    • pp.311-319
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    • 2012
  • This study, by grasping the degree of anxiety of Korean mothers and multicultural family mothers because of their hospitalized children, was aimed to arrange the basic data for developing the program to help the mothers of Korea and multicultural family reduce the anxiety happening due to the hospitalization of their children and adapt to their environment. Methods: The subjects of the study were a total of 200 people composed of 100 multicultural family mothers, and 100 Korean mothers respectively whose children were hospitalized in the pediatric department of K university hospital located in Daejeon City. And the period of data collection was from Aug 1, 2010 to Aug 31, 2010.As a study tool, the measuring tool of Kim Jeong Taek(1978), which STAI of Sielberger(1972) was adapted to Koreans, was used.The collected data was analyzed using SPSS WIN 12.0. Results. A result of the state anxiety of the Korean mothers with that of the multicultural family mothers of the inpatient children, Korean mothers 2.11, multicultural family mothers 2.17, result of temperament anxiety showed Korean mothers 2.09, multicultural family mothers 1.94. As a result of comparing the anxiety of the Korean mothers with that of the multicultural family mothers of the inpatient children, there was no difference between groups in both temperament anxiety and state anxiety. In a situation of anxiety, when there was no explanation of the treatment or therapy, both Korean mothers and multicultural family mothers showed the severe anxiety. In the degree of anxiety according to the general characteristics of the mothers of the inpatient children, there was not a statistically significant result in anxiety according to general characteristics of the inpatient children of korean family mothers, there was a significant difference in state anxiety according to the state of average monthly income in Korean mothers(P<.05), however, there was a significant one in temperament anxiety in the course of perceiving a test method in multicultural family mothers(P<.05). In the degree of anxiety according to the general characteristics of the mothers of the inpatient children, there was a significant difference in state anxiety according to the state of average monthly income in Korean mothers(P<.05), however, there was a significant one in temperament anxiety in the course of perceiving a test method in multicultural family mothers(P<.05). Conclusion: Through the results of the study above, no matter what socio-demographic characteristics of the mothers of the inpatient children are, regardless of the general characteristics of the inpatient children, it was found out that most of mothers felt anxiety.

Growth and Yield Components Responses to Delayed Planting of Soybean in Southern Region of Korea (남부지역 콩 만파에 따른 품종별 생육 및 수량반응)

  • Park, Hyeon-Jin;Han, Won-Young;Oh, Ki-Won;Kim, Hyun-Tae;Shin, Sang-Ouk;Lee, Byong-Won;Ko, Jong-Min;Baek, In Youl
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.59 no.4
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    • pp.483-491
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    • 2014
  • Double cropping system including paddy field soybean is widely adopted nationwide, due to rise in market price and its higher income than paddy field rice. Sowing date of soybean as a second crop is being delayed depending on first crop's growth period and harvesting time. Due to the increased temperature in October and delayed first frost date, soybean could be harvested without frost damage even in late-plating. Therefore, selection of soybean cultivar which is appropriate for this environment is very important. The effect of sowing date and genotype of soybean on growth and yield was investigated for three planting dates (June 20, July 5, and July 20) with ten cultivars developed for soy-pate production, to figure out plant development and yield pattern in delayed planting. As planting date is delayed, plant height and pod number was decreased and this pattern was more clearly detected in mid-late maturity cultivars. Hundred-seed weight did not show significant changes even in late planting, due to compensations between yield components. Yield reduction of July 20 in contrast to that of June 20 showed that Nampung (9.6%) showed the least yield decline. Maximum yield was achieved from Daepung, Taekwang, and Uram among other soybean cultivars in late planting. Shortening of growth period was strongly detected in reproductive stage while length of vegetative stage was regularly maintained in both early and mid-late maturity cultivars.

Study on Strain Measurement of Agricultural Machine Elements Using Microcomputer (Microcomputer를 이용(利用)한 농업기계요소(農業機械要素)의 Strain 측정(測定)에 관(關)한 연구(硏究))

  • Kim, Kee Dae;Kim, Tae Kyun;Kim, Soung Rai
    • Korean Journal of Agricultural Science
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    • v.8 no.1
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    • pp.90-96
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    • 1981
  • To design more efficient agricultural machinery, the accurately measuring system among many other factors is essential. A light-beam oscillographic recorder is generally used in measuring dynamic strain but it is not compatible with the extremely high speed measuring system such as 1,000 m/s, also is susceptable to damage due to vibration while using the system in field. The recorder used light sensitive paper for strip chart recording. The reading and analysis of data from the strip charts is very cumbersome, errorneous and time consuming. A microcomputer was interfaced with A/D converter, microcomputer program was developed for measuring, system calibration was done and the strain generated from a cantilever beam vibrator was measured. The results are summarized as follows. 1. Microcomputer program was developed to perform strain measuring of agricultural machine elements and could be controled freely the measuring intervals, no. of channels and no. of data. The maximum measuring speed was $62{\mu}s$. 2. Calibration the system was performed with triangle wave generated from a function generator and checked by an oscilloscope. The sampled data were processed using HP 3000 minicomputer of Chungnam National University computer center the graphical results were triangle same as input wave and so the system have been out of phase distorsion and amplitude distorsion. 3. The strain generated from a cantilever beam vibrator which has free vibration period of 0.019 second were measured by the system controlled to have l.0 ms of time interval and its computer output showing vibration curve which is well filted to theoretical value. 4. Using microcomputer on measuring the strain of agricultural machine elements could not only save analyzing time and recording papers but also get excellent adaptation to field experiment, especially in measurement requiring high speed and good precision.

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Conversion of an Anaerobic Digester to Thermophilic Range (혐기성소화조(嫌氣性消和槽)의 고온(高溫)에로의 전환(轉換))

  • Chang, Duk;Chung, Tai Hak
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.6 no.4
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    • pp.21-28
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    • 1986
  • Conversion of anaerobic mesophilic digestion to thermophilic range has been investigated using a synthetic sludge. When temperature was raised at a rate of 2, 1, and $0.5^{\circ}C$ per day with continuous feeding, a lower reaction rate was observed with a high rate of temperature change. Although methane fermentation ceased completely for an digesters at thermophilic temperature, acid fermentation continued. Methane fermentation was never achieved even with neutralization during 6 months of resting. The methane formers were completely inactivated by the temperature shock and accumulation of volatile acids due to continuous feeding, while the acid formers lost biological activity quickly, but gradually acclimated to a high temperature. When temperature was raised without feeding, successful thermophilic digestion was achieved with 1 day of resting at thermophilic temperature at a rate of $1^{\circ}C$ per day, and also achieved with 20 days of resting at a direct increase. Conversion to a thermophilic range is easily achieved with resting. A short period of resting is required at a low rate of temperature increase, while a long period of resting enough to balance methane formers with acid fermers makes a conversion possile when temperature is raised at a high rate. Soured thermophilic digesters were recovered after seeding of mesophilic sludges, and sludge seeding could be a good method of start-up, conversion, or recovery of a thermophilic digester. Significant amount of thermophiles seemed to be present in the mesophilic digesters.

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Limiting Nutrients for Phytoplankton Growth in the Seomjin River Estuary as Determined by Algal Bioassay Experiment (생물검정실험에 의한 섬진강 하구역 식물플랑크톤 성장의 제한영양염 평가)

  • Kwon Kee Young;Kim Chang Hoon;Kang Chang Keun;Moon Chang Ho;Park Mi Ok;Yang Sung Ryull
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.35 no.5
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    • pp.455-461
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    • 2002
  • limiting nutrients for phytoplankton were determined by dissored inorganic nitrogen/phosphorous (DIN/DIP) in situ and algal bioassay experiment in the Seomjin River estuary during a study period from March 1999 to October 2001. DIN/DIP ranged from 14.7 to 681.1 during the study period. DIN/DIP was over 16 at the upper and middle estuarine region where salinity was lower than 25 psu and chlorophyll a concentration was high, probably indicating P-limitation in this region while the ratio was less than 16 at the high saline (> 25 psu) region, reflecting the supply of DIP from Gwangyang Bay and thereby indicating N-limitation at the lower estuarine region. These results suggested that the spatial distribution of DIN/DIP in the study region was controlled by the high supply of phosphate from Gwangyang Bay, the low input from Seomjin River and the active uptake by phytoplankton within the estuarine system. The bioassay experiments using Skeletonema costatum, Thalaasiosira rotula and in situ phytoplankton assemblage displayed relatively higher growth of phytoplankton in the P-added culture media, indicating P-limitation. This result was well consistent with the spatial distribution of inorganic nutrients. S. costatum showed a rapid adaptation to the low salinity compared to other phytoplankton species. This phenomenon seemed to account for the strong (> $90\%$ in total cell number) S. costatum bloom in autumn in this estuary. Moreover, although phytoplankton growth rate was higher in the P-added culture media at the end of culture experiment of in situ phytoplankton, the fast growth in the trace metal-added media at the beginning of the experiment suggested a possibility of limitation by other micro-nutrients such as trace metal and vitamin etc.

ORAL HEALTH BEHAVIORS OF MOTHERS AND DENTAL CARIES IN CHILDREN FROM MULTICULTURAL FAMILIES (다문화가족 어머니의 구강건강행동과 자녀의 치아우식경험에 관한 연구)

  • Lee, Hye-Lim;Lee, Kwang-Hee;La, Ji-Young;An, So-Youn;Kim, Yun-Hee
    • Journal of the korean academy of Pediatric Dentistry
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    • v.39 no.2
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    • pp.111-119
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    • 2012
  • The objectives of this study were to evaluate oral health status of children in multicultural families and compare oral health behaviors of multicultural mothers with those of ordinary Korean families. The mothers' social characters, oral health behaviors and oral health status of children were investigated so that the data from this study can be utilized in developing programs for oral health care promotion especially designed for multicultural families. The subjects were 135 pairs of multicultural mothers and their children who participated in the community programs in suburban areas of Ik-san city and 168 pairs of ordinary Korean mothers and their children residing in Ik-san city. The results were as follows : 1. The dft index and dfs index of multicultural subjects were 4.17 and 6.67, respectively, while ordinary Korean subjects were found to have 2.69 and 4.63($p$ <0.05). 2. The frequency of tooth brushing per day of children from multicultural families was lower than that of children from ordinary Korean families($p$ <0.01). 3. The ratio of practice of oral health behaviors of mothers from multicultural families was lower than that of mothers from ordinary Korean families($p$ <0.01). Tooth brushing instructions were the most frequently carried out by multicultural mothers, which was followed by teaching the importance of oral health, restriction of carbohydrates, and dental check-ups. Significant correlations were not detected between mothers'oral health behaviors and children's dental caries experiences($p$ >0.05).