• 한국건설순환자원학회논문집
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• 제8권4호
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• pp.562-570
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• 2020

본 연구에서는 단위중량 2,000kg/㎥ 이하의 고강도 시멘트 복합체 제조기술 및 기초 물성을 탐구한다. 선행연구에서 제시한 초고성능콘크리트의 배합에서 잔골재를 경량 재료인 솔리드 버블과 경량잔골재로 치환하여 경량 고강도 시멘트 복합체를 제조기술을 제안한다. 솔리드 버블을 혼입한 시멘트 복합체는 밀도 2.0g/㎤ 이하에서 재령 28일 강도 116MPa~141MPa의 고강도 발현이 가능한 것으로 나타났다. 경량잔골재를 사용하는 경우 솔리드 버블을 혼입한 시멘트 복합체보다 역학적 성능이 떨어지는 것으로 나타났다. 배합표상에서 계산된 단위용적중량과 경화된 시멘트 복합체의 밀도가 큰 차이를 보이지 않았으며, 이는 배합표상에서 계산된 단위용적중량을 통해 경화된 시멘트 복합체의 밀도를 추정할 수 있는 것을 보여준다.

• 한국초지조사료학회지
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• 제9권3호
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• pp.135-140
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• 1989

This experiment was to study the relationship between shoot and root system in perennial ryegrass at different stages of growth. The results are summarized as follows; 1. The dry weight of shoot was significantly correlated with the dry weight of root at both stages of growth. 2. The yield components of shoot and root systems were changed by the stages of growth. Thus, the dry weights of shoot and root were positive correlated with the number of tillers and roots at 60 days after sowing. But, the dry weights of shoot and root were positive correlated with the dry weight of root, the dry weight of tiller, length of plant and length of root at 90 days after sowing. 3. Maprirna variety was obtained a higher dry weights of shoot and root at 60 days after sowing, but, Alta variety was obtained at 90 days after sowing, respectively. 4. The dry weight of shoot was positive correlated with leaf area at both stages of growth. 5. The dry weight of shoot was significantly negative correlated with specific leaf weight at 60 days after sowing, but positive correlated with specific leaf weight at 90 days afikr sowing. 6. The dry weight of root was smcantly positive correlated with leaf area at 60 days after sowing, but not recognized at 90 days after sowing.

• Animal Bioscience
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• 제37권5호
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• pp.839-851
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• 2024

Objective: The main goal of our current study was to improve the growth curve of meat animals by decreasing the birth weight while achieving a finishing weight that is the same as that before selection but at younger age. Methods: Random regression model was developed to derive various selection indices to achieve desired gains in body weight at target time points throughout the fattening process. We considered absolute and proportional gains at specific ages (in weeks) and for various stages (i.e., early, middle, late) during the fattening process. Results: The point gain index was particularly easy to use because breeders can assign a specific age (in weeks) as a time point and model either the actual weight gain desired or a scaled percentage gain in body weight. Conclusion: The point gain index we developed can achieve the desired weight gain at any given postnatal week of the growing process and is an easy-to-use and practical option for improving the growth curve.

• 한국초지조사료학회지
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• 제12권4호
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• pp.226-231
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• 1992

This experiment was carried out to estimate the dry matter accumulation using growth analysis in spring growth of perennial ryegrass varieties grown under space planting conditions, based on the data of previous paper9'. The results obtained were as follows: 1. Growth parameters of leaf area ratio(LAR), specific leaf area(SLA) and leaf weight ratio(LWR) were recognized siginificant differences between varieties. But, specific leaf area(SLA), leaf weight ratio (LWR) and relative tiller appearance rate(RTAR) were recognized significant differences between growth stages. Specific leaf area(SLA) was significant difference for the interaction of variety Xgrowth stage. 2. The relative growth rate of biological yields(BYRGR) indicated significantly positive correlations with relative growth rate of shoot(RGR) and root(RWGR), and net assimilation rate(NAR) as affected by the varieties and growth stages. 3. The relative growth rate of biological yields(BYRGR) indicated significantly positive correlation with nct assimilation rate(NAR) in all varieties. Leaf area ratio(LAR) had significantly positive correlation with specific leaf area(SLA) in all varieties, but shows a significant negative correlation with leaf weight ratio(LWR) of Maprima variety. 4. The relative growth rate of biological yields(BYRGR) indicated significantly positive correlations with the absolute growth rates of yield components.

• Environmental Analysis Health and Toxicology
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• 제21권4호
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• pp.349-355
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• 2006

Dextromethorphan hydrobromide (DXM) has been widely used as a nonopioid antitussive drug with low toxicity and low potential for drug dependency. DXM is a psychotropic drug since 2003 in our country. This study was performed to investigate the immunotoxicity induced by abuse of DXM. Mice were orally exposed to DXM dissolved in saline as concentration of 30, 60, and 120 mg/kg b.w. before (day-2) or after (day+2) immunization (OVA-antigen, day 0). Thereafter, we measured the increased rate of body weight, relative weight of organ (thymus, spleen, liver, kidney) and OVA-specific IgM level in sera. In addition, mouse splenocytes were exposed to various concentration of DXM $(0.001{\sim}100{\mu}M)$ and cultured with B cell mitogen (LPS) and splenocytes proliferations (SP) were measured by MTT-assay. Thymus-weight were slightly changed on day 9 after administration of DXM, but body-, spleen-, liver-, and kidney-weight were not different between control group and DXM-treated group. SP to LPS were significantly decreased at high concentration $(100{\mu}M)$ when compared with controls. When DXM was administered before or after immunization with OVA-antigen, OVA-specific IgM levels were significantly lowered in a dose-dependent manner. These results indicate that DXM nay depress the primary humoral immune response to the initial antigenic challenge.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1998년도 가을 학술발표회논문집
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• pp.410-413
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• 1998

Since early of 1980's, high. performance fiber has been developed by processing of ultrahigh molecular weight polyethylene(UHMWPE). UHMWPE fibers have high strength high modulus and excellent impact properties due to the strong C-C bond. Furthermore, the specific gravity of UHMWPE fibers is less than 1.0g/$\textrm{cm}^2$, which makes it possible to produce composites that combine good mechanical properties with low specific mass. (omitted)

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2010년도 춘계학술대회 논문집
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• pp.219-220
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• 2010

• 한국작물학회지
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• 제46권2호
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• pp.89-94
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• 2001

Sword bean belongs to the subgenus Canavalia in the genus Canavalia. White and reddish varieties in sword bean were tested to obtain the basic information for improving the yield, quality, and cultural environments through the quantitative growth analysis. Growing plants were sampled at intervals of 10 days from 20 days after sowing. Whole plant weight increased during the period of 11-20 days after sowing in both varieties. The weight of each organ between two varieties increased similarly except leaf area. Whole plant weight changed more close to pod weight than any other characters. The leaf areas of both varieties increased from 50 days after sowing, var. white displayed S type curved line but var. reddish displayed slow S type curved line. The SGR of whole plant weight in both varieties had 3 maxima and 2 minima, 3 maxima and first minimum were shown at the same period but the second minimum was shown at different period. Both varieties showed bimodal curved line. All SGR of each organ and leaf area were shown the 2 maxima and 1 minimum in both varieties. The changes of SLA and LAR were not remarkable between two varieties but these were united together with the maximum of whole plant weight and root weight. ULWR and ULWR were shown similar in both varieties. Reddish variety was more prosperous in early growth stage than white variety because SLA, LAR and LWR were high. In surplus weight, both varieties increased rapidly during the period of 111-120 days after sowing that was applicable to the maximum SGR of pod weight. Surplus weight of var. white increased markedly during the same period comparing those of var. reddish.

• 한국패류학회지
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• 제32권2호
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• pp.103-109
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• 2016

본 연구는 3년산 북방전복의 해상가두리의 먹이공급비율에 따른 성장 및 생존율을 조사하여, 미역과 다시마등의 천연먹이의 적정 공급율을 제안하여 북방전복 성패의 생산성 향상을 유도하고자 실시하였다. 먹이공급율은 실험전복 어체중량을 기준으로 일간공급율 (daily feeding rate, DFR) 5, 10, 15, 20% (5 DFR, 10 DFR, 15 DFR, 20 DFR) 를 설정하여, 해상가두리에서 2반복으로 13개월간 실시하였다. 해상가두리에서 사육한 전복 (최초 수용 시 평균각장 $73.77{\pm}11.27mm$) 성장에서 각장과 각폭의 성장율 (growth rate, GR), 일간성장율 (daily growth rate, DGR) 및 특수생장율 (specific growth rate, SGR) 과 체중의 증중률 (weight gain, WG), 일간증중률 (daily weight gain, DWG) 및 특수증중률 (specific weight gain, SWG), 그리고 생존율에서 5 DFR이 유의적으로 높았다 (P < 0.05). 생존율은 모든 실험구가 유의적 차이가 없었으며, 30%이하로 나타났다. 따라서 3년산 북방전복을 해상가두리에서 사육 시 미역, 다시마 등의 생먹이의 일간 공급율은 어체중량의 5-10%에서 공급되는 것이 성장에 유리하지만, 생존율을 향상 시킬 수 있는 다각적 검토가 필요하다.

• KSBB Journal
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• 제5권3호
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• pp.235-240
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• 1990

Pseudomonas elodea 에 의한 Gellan gum생산시 이에 관련된 기초자료를 얻기 위하여 회분식 및 연속식 발효를 하였다. 회분식 배양의 결과로부터 비성장 속도는 $0.16hr^-^1$이었으며 72시간 배양후의 점도는 4500cp, 생성물 농도 0.7g dry weught/100g broth, 및 생산성은 0.08g dry weight/1/hr이었다. 연속식 배양을 통하여 최적 탄소원과 질소원의 농도비(3.0mg-carbon/mg-nitrogen)를 결정하였으며 Gellan gum의 최대 생성속도는 희석율 $0.14hr^-^1$에서 0.6g dry weight/l/hr이었다. 이러한 조건에서 각종 metabolic paeameter값을 계산하였다. 또한 배양액의 유변학적 특성은 Casson equation에 잘 부합됨을 확인하였고, 배양액의 점도와 산소전달계수를 측정하여 고점도 배양시 산소전달의 장애현상을 조사하였다.