• Journal of Life Science
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• v.16 no.6
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• pp.890-897
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• 2006

The purpose of this study is to investigate the effects of BCAA and additional OKG or albumin supplementation on energy metabolism and hormone changes in prolonged submaximal exercise. The subjects of this study were 5 male college students, and they took participated in each experiment. In each experiment (control, BCAA, BCAA+OKG, BCAA+albumin), the subject ran for 90 minutes on the treadmill. Blood was drawn and analyzed as glucose, FFA, ammonia, growth hormone, insulin, cortisol, $T_3$, and $T_4$. The obtained results were analyzed via two-way repeated ANOVA using SPSS program. A value of p<.05 was considered statistically significant. The concentration of glucose was the lowest in the BCAA supplement group, and there was significant difference between times of exercise (p<.05). In concentration of FFA, there was a significant difference between times of exercise and supplemented groups (p<.05). The concentration of blood ammonia was the lowest in the BCAA+albumin supplement group, and was the highest in the BCAA supplement group. Concentration of growth hormone, cortisol, $T_3$ and $T_4$ were increased as exercise progressed and decreased after all exercise. But concentration of insulin was decreased as exercise progressed. In these results, BCAA and additional OKG or albumin supplement with BCAA may make better effect to the increasing energy generation and inhibiting protein degradation during prolonged submaximal exercise.

• Magazine of the Korean Society of Agricultural Engineers
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• v.22 no.3
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• pp.60-74
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• 1980

Soil-cement mixtures involve problems in it's durability in grain size distribution and mineral composition of the used soils as well as in cement content, compaction energy, molding water content, and curing. As an attempt to solve the problems associated with durability of weathered granite soil with cement treated was investigated by conducting tests such as unconfined compression test, it's moisture, immers, wet-dry and freeze-thaw curing, mesurement of loss of weight with wet-dry and freeze-thaw by KS F criteria and CBR test with moisture curing on the five soil samples different in weathering and mineral composition. The experimental results are summarized as follows; The unconfined compressive strength was higher in moisture curing rather than in the immers and wet-dry, while it was lowest in freeze-thaw. Decreasing ratio of unconfined compressive strength in soil-cement mixtures were lowest in optimum moisture content or in the dry side rather than optimum moisture content with freeze-thaw. The highly significant ceofficient was obtained between the cement content and loss of weight with freeze-thaw and wet-dry. It was possible to obtain the durability of soil-cement mixtures, as the materials of base for roads, containing above 4 % of cement content, above 3Okg/cm$_2$ of unconfined compressive trength with seven days moisture curing or 12 cycle of freeze-thaw after it, above 100% of relative unconfined compressive strength, 80% of index of resistance, below 14% of loss of weight with 12 cycle of wet-dry and above 1. 80g/cm$_2$ of dry density.

• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.1
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• pp.43-48
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• 1998

No-tillage silage corn with legume hairy vetch(Vicia villosa Roth, HV) has renewed interest in supply of mineral N, soil erosion control at sloping land and weed control by cover of HV killed. This study was conducted to monitor concentration of soil mineral N ($NO_3^-$ -N + $NH_4^+$-N) and to find out variation of growth, yield and N uptake of silage corn according to quantity of HV cover; HV-removed, 1X-HV, 2X-HV at field of Crop Experiment Station in 1996. HV groM in early spring decreased the mineral N of soil depth 7.5 -22cm before corn seeding. But, killed HV cover increased the concentration of soil mineral N at surface soil (0-7.5cm) up to 45.4mglkg at early growth stage of corn. Dry matter(Dh4) of corn at harvest was lower in W-removed than in Okg FNlha. But DM and N uptake of corn at harvest were increased by quantity of HV-cover increasing liom HV-removed to 2X-HV. Hairy vetch could substitute N fertilizer for silage corn by N mineralized h m HV killed, but reduced early growth and N uptake of corn before silk by reducing soil mineral N of plow layer.

• Journal of The Korean Society of Grassland and Forage Science
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• v.7 no.2
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• pp.109-112
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• 1987

This experiment was to study the effects of soil compaction and artificial pore space on the shoot density of tall fescue (Festuca arundinacea Schreb.). Tall fescue subjected to compaction treatments with control, 10, 20 and 40 kg power roller, used for two times bi-weekly during six months. Artificial pore space treatments were control, 13.5, 37.5 and 84.5% at 0-lOcm depth, respectively. 1. Soil compaction increased soil hardness and soil bulk density.2. Compaction level of lOkg (soil hardness 2.5kg/$cm^3$) showed the highest shoot density than that of other treatments. 3. Artificial pore space was positive significant correlated (p<0.01) with shoot density. 4. When over the 37.5% of total pore space could be mainternance for high shoot density after the soil compacted.

• Asian Journal of Turfgrass Science
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• v.3 no.2
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• pp.77-82
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• 1989

This experiment was carried out to determine the value of turfgrass clippings as a source of protein for animal feed. Levels of crude protein(CP) and in vitro dry matter digestibility(JVDMD) were determined for Korean lawngrass (Zoysia Japonica Steud.) under three levels of nitrogen fertilizer ( 0 , 350 and 700kg ha year and three levels of mowing interval between cuts (lO, 20, and 30 days). Sampling was done on the three-year old turffield on which nitrogen and mowing treatments were Imposed. Clippings were collected after mowing, and CP levels were calculated from a measurement of total N(CP = N >< 6.25) l)y Auto-analyser system-2 procedure and IVDMD by Maeng's method which was partly modified with Tilley and Terry's procedure. With the increased nitrogen legime the CP content of leaf clippings varied from 6.6 to 13.6% and that Of stem clippings from 4 to 10.3%. The CP levels of clippings were directly proportional to the N fertilization rate. The highest CP content was recorded in early July when it was 14.1% at 35OkgN ha -and I 18.l%kgN ha-1 with 10-wcek mowing interval. Mowing interval had little effect on the CP content in both leaf and stem clippings. The level of IVDMD in the Korean lawngrass clippings varied with mowing interval. The highest level measured was 47%, hut this varied during the growing season and occurred in the following order : early summer > summer > fall. This experiment has shown that Korean lawngrass clippings can he helpful source of protein for use in some animal feeds and that a high concentration of CP can occur depending upon N fertllizer and that of I VDM I) upon mowing practices.

• Journal of the KSME
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• v.44 no.1
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• pp.27-27
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• 2004

미국 국방부 소속 육군차량사업부(National A Automotive Center)는 대체에너지를 이용한 군용 차량 개발을 위해 Michigan 주 Rochester Hills에 위치한 E Energy Conversion Devices(ECD) 사와 일부 기술 개발 에 대한 기술 제휴를 한다고 발표했다. 국방부는 태양전 지와 수소를 연료로 사용하는 대체에너지 차량을 개발하 기 위해 ECD에 1단계 연구에 필요한 연구비를 지원했다. 이번 연구에는 연료전지를사용한차량개발을위해 5 500,$\omega$0달러가 투자되는데, Texaco Ovollic Hydrogen S Systems(TOHC)의 고체 휴대용 수소 연료와 채충천 (refueling) 시스탬이 주요 개발 목표로 설정됐다. ECD의 역할은 최근 개발된 Toyota Prius에 시범 적으로 장착된 저압 고체형 수소 저장 시스템의 기술을 군용 차량에 알맞게 전환시키는 것이다. TOHC와 ECD가 개발한 고체형 수소 보관 시스댐은 고압을 요구하는 연료전지 차량의 수소 저 장 시스템이 갖고 있는 많은 문제점들을 해결할 수 있을 것으로 기대되는 연료전지를 이용한 엔진 개발 중 최신 기술이다. 특히 전투 상황에서 차량이 폭발하기 쉬운 수소 저장 탱크를 장착한 채 전 장으로간다는 것은적에게 노출 될 경우자살과마찬가지인 치명적인 피해를 입을수 있다. 이 프로젝트의 개요를 살펴보면, 수소 저장 시스템은 적어도 약 lOkg의 수소를 적은 용적 내에 낮은 압력에서 안전하게 고체 상태로 저장할 수 있다. 이 고체 저장 용기는 하루에 두 번 1.7kg의 수소를 10분 이내에 재급유할 수 있다. 수소는대부분고압가스형태나저온액체 형태로보관된다. 기체나액체 형태의 수소는 연료전 지에 사용되기에는 적합하지 않은 점이 많다. Ovonie 수소 저장 방법은 수소를 저압 고체 형태 ( (metal hydride)로 보관하는 방법으로, 고압 기체나 저온 액체가 갖고 있는 많은 문제점들을 해결 할수있다. 그림을 참조하면 고체 형태의 수소 보관 방법이 다른 보관 방법에 비교해 단위 체적당 최고 6배 많은수소질량을보관할수 있다. 이 고체 형태의 보관방법은수소가적절한합금과평형 압력 이 상의 환경에 놓일 경우 합금에 홉착되는 현상을 이용하고 있다. 수소를 흡수한 합금은 새로운 특성 을 가진 metal hydride로 변하게 된다. 이 과정 에서 열이 부산물로 발생한다. 반대로 수소를 metal hydride로부터 분리시키기 위해서는 합금을 가열해야 한다.

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.2
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• pp.121-126
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• 1996

To investigate the effects of potassium($K_2O$) fertilization levels on the dry matter(DM) yield, nutrition yield, and $K_2O$ efficiency of forages in mixed sward of alfalfa-grasses, a field experiment arranged by randomized complete block design with five treatments(0, 60, 120, 180 and 240kg $K_2O$/ha) was conducted at National Livestock Research Institute in Suwon, September, 1990 to February, 1993. During two years, average DM yields of forage increased as $K_2O$ fertilization level was increased, but no significant difference was found between DM 10,617kg of $K_2O$180kgha and DM 10,845kg of $K_2O$ 240kg/ha. Crude protein and energy productivity of forages increased as $K_2O$ fertilization level was increased, and the increasing degree was highest between $K_2O$ 120kg and 180kg/ha fertilization. With increasing $K_2O$ fertilization, mineral contents tended to increase in K and WCa+Mg equivalent ratios, to decrease in Mg, but not to be regular in the other elements. Efficiency of $K_2O$ was relatively high at $K_2O$ 180kgha fertilization, which produced DM 12.2kg, net energy lactation 67.3M.J, starch equivalent 6.2kStE and total digestible nutrients 7.6kg per Ikg $K_2O$. Therefore, potassium($K_2O$) fertilization levels must be applied with I8Okg/ha for a reasonable management in mixed sward of alfalfa-grasses.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.3
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• pp.293-304
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• 1997

A field experiment was conducted at the forage experimental plots, Seoul National University, Suweon h m 1995 to 1996 to determine the effect of legume residues as a N source and N fertilizer on corn (Zea mays L.) silage yield, N uptake, and availability of inorganic N in the soil. Corn was grown following (i) red clover (Trifolium pratense L.), (ii) crimson clover (Trifolium incarnatum L.), (iii) alfalfa (Medicago sativa L.) and (iv) winter fallow. The plots were split into two rates of fertilizer N (0 and 90kg Nlha) in a split-plot experimental plan. Compared with fallow treatment, legumes depleted soil water in the surface 15cm at corn planting by 17 to 26%. As a result, corn emergence was markedly delayed with legume residues by 8 to 11 days. Corn silage DM yield was significantly reduced in the presence of legume residues by 2.0 to 3.4 and 1.5 to 2.5 tonlha compared with winter fallow treatment at 0 and 90kg fertilizer Nlha, respectively, but no significant difference in the corn DM yield was found between legume residue treatments. There was an overall tendency for increased corn yields with 90kg fertilizer Nlha compared to Okg fertilizer Nlha, although not all yield increases were significantly greater. The corn yield response to applied N suggests that a source of N from legume residues was not sufficient for a succeeding corn crop. There was significantly more N (P

• Journal of Embryo Transfer
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• v.12 no.3
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• pp.307-313
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• 1997

Experiments were conducted to assess the effect of quality and viability of bovine blastocysts derived from in-vitro culture(IVC) of in vitro matured and fertilized(IVM-IVF) oocytes during their transport 2 hours. Follicular oocytes were collected form ovaries obtained at a slaughterhouse and were cultured for 24 hours in TCM-199. The IVM oocytes were fertilized in vitro with caudal epididymis spermatozoa. Fertilized oocytes were cultured for 7 to 9 days, and embryos that developed to the blastocyst stage were used for the experiment. The blastocysts, packed in straws with storage medium that consisted TCM-199 with HEPES equilibratd in air and supplemented with 10% FCS were transported at 39~(2.0 h). The quality of blastocysts was assessed and ranked as A(excel-lent), B(Good), fair or poor after transportation. The percentages of A and B grade blastocysts after transport duration for < 1 hours(97.7%) were similar to the result from transport duration for 1~2 hours (92.9%) and 2~3 hours(89.6%), but significantly(P<0.05) higher than transpot duration for 3~4 hours(76.3%). The percentages of A and B grade blastocysts after transport duration for two hours from developed blastocyst at 7day(100%) and 8day(85.0%) were higher 9day(96.6%) and >9day (40.0%). And early to expanded blastocyst produced in vitro were transferred to recipient cow by additional embryos at 7 and 8th day after AI. Three of them were pregnant to term and produced four twin calves, and two calves was premature birth. The gestation lengths of male to female and female to female twin were 282 and 281 days, respectively. And birth weight of twin calves were male to female(22.Skg) and female to female twin(20.3Okg), respectively.

• Nuclear Engineering and Technology
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• v.50 no.2
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• pp.246-252
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• 2018

A series of simulated reactivity-initiated accident (RIA) tests on irradiated fully recrystallized boiling water reactor Zircaloy-2 cladding has been performed by means of the expansion-due-to-compression (EDC) test method. The EDC method reproduces fuel pellet-clad mechanical interaction (PCMI) conditions for the cladding during RIA transients with respect to temperature and loading rates by out-of-pile mechanical testing. The tested materials had a large variation in burnup and hydrogen content (up to 907 wppm). The results of the EDC tests showed variation in the PCMI resistance of claddings with similar burnup and hydrogen content, making it difficult to clearly identify ductile-to-brittle transition temperatures. The EDC-tested samples of the present and previous work were investigated by light optical and scanning electron microscopy to study the influence of factors such as azimuthal variation of the Zr-hydrides and the presence of hydride rims and radially oriented hydrides. Two main characteristics were identified in samples with low ductility with respect to hydrogen content and test temperature: hydride rims and radial hydrides at the cladding outer surface. Crack propagation and failure modes were also studied, showing two general modes of crack propagation depending on distribution and amount of radially oriented hydrides. It was concluded that the PCMI resistance of irradiated cladding under normal conditions with homogenously distributed circumferential hydrides is high, with good margin to the RIA failure limits. To further improve safety, focus should be on conditions causing nonfavorable hydride distribution, such as hydride reorientation and formation of hydride blisters at the cladding outer surface.