육성돈에서 Phytase 첨가가 Extrusion 한 쌀겨의 P 이용성에 미치는 영향

김영길,김인호,손중천,김은주,권기범,문태현 한국영양사료학회 1999 韓國營養飼料學會誌 Vol.23 No.3

본 시험은 육성돈에 있어 extrusion된 쌀겨에 대한 P의 이용성과 extrusion된 쌀겨에 phytase를 첨가하므로서 P의 이용성에 미치는 영향을 구명하고자 영양소 소화 시험을 실시하였다. Extrusion된 쌀겨와 extrusion된 쌀겨에 phytase을 첨가한 구간의 비교는 phytase의 첨가에 의해 건물 소화율이 약간 증가하는 경향을 보였다(P<0.04). N 소화율은 쌀겨구 보다는 extrusion된 쌀겨구에서 약간의 증가를 보였다(P<0.07). Ca(P<0.06)과 P(P<0.01)의 소화율은 모두 extrusion된 쌀겨에 phytase의 첨가수준이 다를 경우 500 unit보다는 1,000 mini에서 더 좋은 효과를 보였다. 분 중 P 배설량(2.72g/d vs 3.89g/d)은 extrusion된 쌀겨보다는 extrusion된 쌀겨에 phytase을 첨가하므로서 줄어들었다(P<0.08). 또한 phytase의 첨가수준이 증가할수록 P의 축적량이 증가함을 알 수 있었다(P<0.04). 한편 Ca 섭취량, 배설량 및 축적량은 모든 처리구 간에 통계적인 유의성을 찾아볼 수 없었다. 그러나 최종 Ca 축적량은 쌀겨에 비해 extrusion된 쌀겨의 경우 15%가 향상되었다(6.64g/d vs 5.77g/d). An experiment was conducted to determine the effects of microbial phytase and feed processing on production and phytate P utilization of pigs. Four crossbred barrows with average initial body weight of 30㎏ were used in 24-d metabolism experiment(4 x 4 latin square) to determine the effect of extruded rice bran and phytase supplementation on nutrient utilization. Digestibility of DM in pigs fed extruded rice bran with phytase improved compared to that in pigs fed extruded rice bran(P<0.04). N digestibility was greater for extruded rice bran than rice bran(P<0.07). However, there was no effect of phytase supplementation to extruded rice bran. Digeshbilities of Ca(P<0.06) and P(P<0.01) were greatest for extruded rice bran with phytase 1,000 unit. Fecal excretion of P(2.72g/d vs 3.89g/d) was less for extruded rice bran with phytase than without phytase(P<0.08). Also, when phytase supplementation was increased in diet, there was increased P retention(P<0.04). There were no treatment effects intake, excretion and retention of Ca. However, Ca retention improved by 15% in extruded rice bran compared to rice bran(6.44g/d vs 5.77g/d).

지하철의 사상사고 및 운전장애 분석에 관한 연구

이동훈,목연수,장성록,권혁무,윤원영,옥영석,최용석,배동철 한국산업안전학회 1999 한국안전학회지 Vol.14 No.3

The purpose of this study is to analyze death injuries and operation troubles of urban transit. No difference was shown in death rates between Line 1 of Pusan urban transit and Line 5, 7, and 8 of Seoul metropolitan transit. And relief time by another train did not depend upon the number of crews. We concluded that thorough inspection and preventive maintenance of trains and facilities are necessary for safe and timely service of urban transit.

조사료의 종류가 홀스타인 송아지 유선의 발달 , 반추위 돌기 및 성장률에 미치는 영향

조광근,최윤재,박영우,윤연화,한영근,윤상기,권웅기 한국영양사료학회 1999 韓國營養飼料學會誌 Vol.23 No.6

본 연구는 홀스타인 송아지에 대한 세 종류의 조사료가 유선조직, 반추위 유두, 번식성적 및 성장률에 미치는 영향을 조사하기 위하여 실시하였다. 출생 후 4일된 송아지(42.9±0.9㎏) 24두를 무작위로 선발하여 출생 후 4∼44일까지 전유를 급여하다가 45일에 그룹 1은 볏짚, 그룹 2는 오차드 그래스, 그룹 3은 알괄파를 급여하였다. 또한 유선조직과 반추위의 발달을 측정하기 위하여 3, 9, 18개월령에 도달하였을 때 각 처리구의 송아지를 1마리씩 도살하였다. 알팔파를 급여한 그룹 3은 다른 처리구에 비하여 중체율이 높았으며, 그룹 2는 영양소 이용률과 번식성적이 높은 경향을 나타내었다. 반추위의 무게는 3개월령 도달시에는 그룹 3이 가장 무거웠으나, 9개월과 18개월령 도달시에는 그룹 2에서 가장 무거운 것으로 나타났다. 반추위의 유두 수는 유두의 성장과 함께 일반적으로 감소하는 경향을 나타내어 유두의 길이와 유두 수와는 서로 상대적인 관계를 나타내었다. 유선의 기능적 활성을 나타내는 RNA/DNA 함량은 3개월 시에는 그룹 3이 가장 낮은 경향을 보였으나 9, 18개월 시에는 반대로 가장 높은 경향으로 나타났으며, 유선세포의 크기를 나타내는 protein/DNA 함량은 18개월 시에 그룹 2가 가장 높은 경향을 보였다. 결론적으로 본 연구에서 볏짚은 반추위의 초기 발달을 촉진하고 알팔파와 오차드그래스는 성장과 번식성적을 증가시키며 또한 초기에 유선의 발달을 촉진시키는 것으로 나타났다. Twenty-four Holstein calves were used to evaluate the effects of three different forages on growth and reproductive performances, and ruminal papillary and mammary developments. Four-day-old Holstein calves weighing 42.9±0.9 ㎏ were randomly assigned to three forage groups of rice straw (group 1), orchard grass hay (group 2), and alfalfa (group 3). All calves received whole milk from day 4 through day 44. At 45 days of age, the animals were assigned at random to one of the three dietary treatments. When calves reached the ages of 3, 9, and 18 months, one calf in each group was sacrifced for evaluation of ruminal and mammary tissue developments. Calves of group 3 gained more body weight than those of other groups, while group 2 showed an effective nutrient utilization and reproduction performance. At 3 months, the stomach weight of group 3 was the highest, however, group 2 provided the highest stomach weight at 9 and 18 months. A remarkable reduction in papillae number was observed in the rumens of all 3- to 9-month-old heifers. A decrease in number of these papillae was observed in all groups exhibiting papillary growth. There was a reciprocal relationship between the number and the length of ruminal papillae. Among the 3-month-old calves, the functional activity (RNAI DNA contents) of the mammary glands of group 3 was lower than those of other groups, whereas the trend was opposite for 9- and 18-month-old heifers. The size of mammary cell (protein / DNA contents) was the greatest for group 2 at 18 months of age. The results suggest that rice straw stimulated earlier development of rumen. Alfalfa and orchard grass improved the growth, reproduction performance, and earlier development of mammary glands.

무가압 침투법에 의해 제조된 Al/BN 복합재료의 미세조직과 인장성질

조수연,이건배,심호섭,허성우,유황룡,권훈 대한금속재료학회(대한금속학회) 2000 대한금속·재료학회지 Vol.38 No.12

Spontaneous infiltration and strengthening behaviors were analyzed in terms of microstructures and tensile properties of Al/BN composite fabricated by pressureless infiltration technique, compared with control alloy without BN fabricated by the same method. The Mg₃N₂ formed by the reaction of Mg vapor and nitrogen gas, which coated the particles in the powder bed, is believed to induce spontaneous infiltration through a great enhancement of wetting via the following reaction, Mg₃N₂+ 2Al→2AlN + 3Mg. This was identified by the finding of AlN particle layers on the surfaces of old Al particles in the powder bed, which contacted with the infiltrating melt. In addition, unreacted Mg₃N₂ was observed outside the composite, where the Al melt directly did not come into contact. Fine AlN particles formed in-situ resulted in a significant strengthening even in the control alloy with no addition of BN. In the composite reinforced with BN, additional AlN was formed by the interfacial reaction of the BN and Al melt as well as AlN by the in-situ reaction. Consequently, both the BN particles and the additional AlN particles formed by the interfacial reaction led to a further strengthening in the composite, as compared to control alloy strengthened by the AlN particles formed in-situ.

HVOF 용사법으로 제조된 TiC-Fe 합금 코팅층의 내마모 특성에 미치는 열처리 영향

김문철,박찬경,진현우,김현민,최상준,권순주 대한금속재료학회(대한금속학회) 2000 대한금속·재료학회지 Vol.38 No.1

The physical soundness, microhardness and wear properties of the thermally sprayed TiC-Fe wear-resistant coatings have been investigated. Thermally sprayed coatings were fabricated by HVOF and the subsequent heat-treatments were carried out at temperatures ranging from 800℃ to 1000℃ in either vacuum or air for 30 minutes. The wear resistance of the as-sprayed TiC-Fe alloy coatings was found to be better than that of Cr₃C₂-NiCr alloy coatings and similar to that of WC-Co coatings. In addition, the wear resistance and hardness of the coating were improved by the following heat-treatment in vacuum(∼10^(-3)torr). The maximum improvement in wear resistance and microhardness was about 20 and 30%, respectively by the heat-treatment performed at 900℃ in vacuum, while the heat-treatment in air deteriorated the wear property due to oxidation. It has been revealed, from TEM and Mo¨ssbauer studies, that the improved wear resistance in the heat treated coating was mainly caused by the hardness increase associated with martensitic transformation. However, no improvement in the wear resistance of the TiC-Fe coatings heat-treated in air seemed to be caused by the residual stress due to the oxidation of Fe matrix.

실리콘고무의 가교제 변화에 의한 유전특성

권병휘,이성일,홍진웅,이준웅,이원재 한국고무학회 1987 엘라스토머 및 콤포지트 Vol.22 No.1

The characteristic of the dielectric relaxation in silicone rubbers were studied in the frequency range of 1×10²∼3×10^6 ㎐ at the temperature range of 30℃∼170℃. As the results of the study, it has been confirmed that the silicone rubber containing the cross-linking agents of 2,5-bis(tert-butylperoxy)-2,5-dimethyl hexane exhibit the dissipation spectra of two kind(α, β dissipation) due to the siloxane and methyl groups. Particularly, the maximum value of dielectric loss spectra of silicone rubber combinning the cross-linking agents of 0.7phr to 1.0phr are on the increasing in high frequency region, but the specimen of above 1.0phr become smaller again The energy and the entropy of activation on the molicular motion obtained 18.32㎉/mole and 1.48㎈/mole·deg in measuring condition respectively.

최근의 금형 표면기술 현황

김성완,이구현,남기석,권식철,백운승 한국열처리공학회 2000 熱處理工學會誌 Vol.13 No.2

순 AI 과 순 Cu 의 진동 특성에 미치는 시편 크기의 영향

장충근,권혁무,박헌범 대한금속재료학회(대한금속학회) 2001 대한금속·재료학회지 Vol.39 No.4

The vibration properties of the pure Al plate and pure Cu plate, 12 ㎜ wide and 164∼254 ㎜ long, were investigated by cantilever beam and RFDA to get the following results. (1) The results by cantilever beam method and RFDA show that the resonance frequency decreases as the specimen length increases or the thickness decreases. (2) When measuring the vibration by the cantilever beam method, the vibration damping coefficients are stable at the specimen with 184 ㎜ or higher length. (3) When measuring the vibration damping coefficient by the cantilever beam method, the mean vibration damping ratio of Al specimen 1.6∼0.8 ㎜ thick is 3.1×10^(-2) and 4.0×10^(-2) in Cu specimen of 2.0∼1.2 ㎜ (4) When measuring the vibration damping properties by the RFDA, vibration damping coefficients are similar regardless of the length and thickness of a specimen and the mean vibration damping ratios of Al and Cu were 2.1×10^(-2) and 2.7×10^(-2), respectively. (5) As a result of (3) and (4), The relationship, between the vibration damping ratio measured by the cantilever beam method and it by the RFDA was founded as g_s=(δ_o/δ_r)×(1/1.5).

배추흰나비 변태에 따른 중추신경계의 형태학적 변화

이봉희,심재원,윤혜련,권도우 고려대학교 한국곤충연구소 1992 昆蟲硏究誌 Vol.18 No.1

배추흰나비 변태에 따른 중추신경계의 형태학적 변화. 이봉희, 심재원, 윤혜현, 권도우 (순천향대학교 자연광학대학 생물학과), 昆蟲硏究誌. 18 : 55 ~ 62, 1992. 곤충 변태에 따른 중추신경계의 형태학적 변화가 배추흰나비(Pieris rapae)5령유충, 1일용, 2일용, 그리고 1일성충에서 조사되었다. 변태에 따라 중추신경계는 인접 신경절사이의 신경삭(nerve connective)이 짧아지거나 길어졌고 인접 신경절사이의 신경삭이 완전히 제거되어 신경절끼리 융합하기도 하였다. 또한 대부분의 신경절내에서도 큰 변화가 수반되었다. 이와같은 중추신경계의 형태학적 변화는 중추신경계의 길이가 상당히 짧아지는 것이 가장 큰 특징이었다. 중추신경계의 길이 감소는 전 변태기 동안 일어났지만 특히 5령유충 중추신경계는 변태기간 동안 계속 길이가 감소하여 1일성충에서는 48%가 감소되어 있었다. 신경절은 또한 서로 융합하여 특히 thoracic neuron center와 abdominal neuron center를 형성하였다. thoracic neuron center는 1일용과 2일용 사이의 변태기간 동안 제1과 제2 복부신경절이 먼저 융합하고 이어서 2일용 이후의 용기에서의 변태기간 동안 융합된 제 1, 2 복부신경절이 제 2와 제 3 흉부신경절과 융합되어있는 제 7과 제8복부신경절은 1일성체로 되는 용기의 변태기간동안 제6복부신경절과 융합하여 abdominal neuron center를 형성하였다. 중추 신경계를 구성하는 모두 13개의 신경절은 주로 용기의 변태기간 동안 구조적으로 분화하여 성충의 중추신경계를 형성하였다. The morphological changes occurring in the central nervous system of Pieris rapae have been investigated during metamorphosis from the fifth instar larva to the 1-day-old adult. These changes consist of (1) shortening or lengthening of the connectives between the neighbouring ganglia, (2) fusion of adjacent ganglia, and (3) sizable changes within the various ganglia. A considerable shortening of the central nervous system occurs through the metamorphic periods which were investigated in this experment; in particular when the fifth instar larva changes to the prepupa and the 1-day-old pupa to the 2-day-old pupa. The 48% of total length of the central nervous system of the fifth instar larva decreases in the 1-day-old adult. The 1st and 2nd dbdominal ganglia fuse completely during a metamorphic period between the 1-day-old pupa and 2-day-old pupa. The fused 1st and 2nd abdominal ganglia fuse again with the 2nd and 3rd thoracic ganglia between the 2-day-old pupa and the 1-day-old adult, forming the thoracic neuron center. The previously fused 7th and 8th abdominal ganglia in the fifth instar larva fuse completely with the 6th abdominal ganlion between the 2-day-old pupa and the 1-day-old adult, forming the abdominal neuron center. The extensive differentiaton of the various ganglia, especially cerebral ganglion, occurs mostly during the pupal stages.

LDPE 에서 발생된 전기트리에 수반된 내부 부분방전 펄스 해석

박영국,임기조,강성화,권순석,신태수 한국산업안전학회 1999 한국안전학회지 Vol.14 No.1

전력용 케이블은 전선로의 지중화 추세에 따라 사용이 증가하고 있다. 케이블 절연체의 경우 장기간의 전압인가에 의해 열화 및 절연파괴 된다. 전력용 케이블의 절연파괴시 발생하는 사회/경제적 문제는 매우 심각한 것으로 알려져 있다. 절연체의 열화에 영향을 주는 요인은 매우 복잡하지만 그중에서도 전기트리 열화에 의한 파괴는 비교적 두꺼운 고체 유전체인 경우에 절연파괴 사고의 주된 원인이 되고 있다. 전기트리의 개시나 진전시 부분방전이 발생하므로 부분방전의 검출에 의해 전기트리의 발생 및 진전 양상을 관측할 수 있고 부분방전의 해석에 의해 절연재료의 잔여 수명을 예측할 수 있다. 본 논문에서는 고전압 전력용 케이블 절연재로써 광범위하게 사용되고 있는 저밀도 폴리에틸랜 시편에서의 전기트리 진전 양상을 비파괴 진단 기법에 의하여 검출하고자 내분 부분방전을 관측/해석하였다. The correlation between propagation of electrical tree and internal partial discharges is discussed. We use specimens with needle-plane electrode system made of LDPE(Low Density Polyethylene), observed inception and propagation of electrical tree by optical microscope and investigated the characteristics of the partial discharge (PD) pulses accompanying with propagation of electrical tree. In the specimens with needle-shaped void, the tree propagates branch type. The length of the tree has good linear relation with average discharge power of PD pulses. In the specimens without needle-shaped void, the tree grows bush type tree. The correlation between the area of the tree and the average discharge power of PD pulses has linear relation.