• 한국세라믹학회지
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• 제41권3호
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• pp.235-242
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• 2004

원재료로서 Si, NH$_4$Cl, NaN$_3$, NaCl을 사용하고 SHS법을 이용하여 $\alpha$-Si$_3$N$_4$ 분말을 제조하였다. NH$_4$Cl과 NaN$_3$는 첨가제로서, NaCl은 희석제로서 사용되었고 반응기내 최초 $N_2$ 압력은 60 atm이었다. $\alpha$-Si$_3$N$_4$분말을 제조함에 있어, 첨가제의 종류와 조성, 희석제의 첨가량에 따른 반응성 및 생성물의 특성을 조사하였는데, 우선 $\alpha$-Si$_3$N$_4$ 분말의 제조를 위한 최적의 반응계를 조사하였고, 최적의 반응계에서 최적의 조성을 확립하였다. 최적의 반응계는 Si-$N_2$-additive(NH$_4$C+NaN$_3$)-diluent(NaCl)이었고, 이때 최적의 조성은 38wt%Si+22.5wt%NH$_4$Cl+27.5wt%NaN$_3$+l2wt%NaCl이었다. 이 조건에서 생성된 최고 $\alpha$-Si$_3$N$_4$의 분율은 96.5wt%이었으며 생성된 분말의 입형은 길이가 약 10 $mu extrm{m}$이고 직경이 약 1 $\mu\textrm{m}$인 일방향으로 길게 성장한 부정형의 fiber 형태였다.

• Corrosion Science and Technology
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• 제3권3호
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• pp.112-117
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• 2004

This work investigated the material properties of Ni-P-B alloy electrodeposits obtained from a Ni sulfamate bath as a function of the contents of the P and B sources($H_3PO_3$ and dimethyl amine borane complex(DMAB), respectively) with/without additives. Chemical composition, residual stress, microstructure and micro hardness were investigated using ICP(inductively coupled plasma) mass spectrometer, flexible strip, XRD, TEM and micro Vickers hardness tester, respectively. From the results of the compositional analysis, it was observed that P and B are incorporated competitively during the electrodeposition and the sulfur from the additive is codeposited into the electrodeposit. The measured residual stress value increased in the order of Ni, Ni-P, Ni-B and Ni-P-B electrodeposits indicating that boron affects the residual tensile stress greater than phosphorus. As the contents of the alloying element sources of P and B increased, crystallinity and the grain size of the electrodeposit decreased. The effect of boron on crystallinity and grain size was also relatively larger than the phosphorus. It can be explained that the boron with a smaller atomic radius contributes to the increase of residual stress in the tensile direction and the larger restraining force against the grain growth more significantly than the phosphorus with a larger atomic radius. Introduction of an additive into the bath retarded crystallization and grain growth, which may be attributed to the change of the grain growth kinetics induced by the additive adsorbed on the substrate and electrodeposit surfaces during electrodeposition.

• 한국자기학회지
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• 제16권4호
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• pp.201-205
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• 2006

$(Ni_{0.2}Cu_{0.2}ZnO_{0.2})_{1.02}(Fe_{2}O_{3})_{0.98}$의 기본 조성에 첨가제 $Bi_2O_3$와 $ZrO_2$ 첨가량과 소결 온도를 변화시켜 시편의 전자기적 특성 및 미세 구조를 조사하였다. 그 결과 XRD pattern을 통하여 완전한 spinel 구조를 가짐을 확인 할 수 있었으며 소결 온도와 첨가제의 양의 증가에 따라 소결 밀도, 입자 크기가 증가 하였으며, 소결 온도가 증가하고 첨가제의 양이 감소할수록 시편의 투자율이 크게 관찰되었다. 또한, $Bi_2O_3$의 첨가가 입자의 크기와 투자율 변화등 전자기적 특성에 더욱 더 많은 영향을 미치는 것으로 조사되었다.

• 한국전기전자재료학회논문지
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• 제13권5호
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• pp.402-410
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• 2000

The electrical properties and stability of Pr$_{6}$/O$_{11}$-based ZnO wvaristors consisting of ZnO-Pr$_{6}$/O$_{11}$-CoO-Dy$_{2}$/O$_{3}$ based ceramics were investigated in the Dy$_{2}$/O$_{3}$ additive content range o 0.0 to 2.0 mol%. The density was nearly constant 5.62 g/cm$^3$corresponding to 97% of theoretical density as Dy$_{2}$/O$_{3}$ additive content increases up to 0.5 mol%. However the density decreased as Dy$_{2}$/O sub 3/ additive content is further additive content. Pr$_{6}$/O$_{11}$-based ZnO varistors doped with 0.5mol% Dy$_{2}$/O$_{3}$ exhibited a good nonlinearity, which is 37.76 in the nonlinear exponent and 5.36 $mutextrm{A}$ in the leakage current. And they exhibited very stress (0.80 V$_{1mA}$/9$0^{\circ}C$/12h)+(0.85 V$_{1mA}$/115$^{\circ}C$/12h)+(0.95 V$_{1mA}$/1$25^{\circ}C$/12h). Consequently it was estimated that ZnO-0.5 mol% Pr$_{6}$/O$_{11}$-1.0 mol% CoO-0.5 mol% Dy$_{2}$/O$_{3}$ based ceramics will be sufficiently used as a basic composition to develop the advanced Pr$_{6}$/O$_{11}$-based ZnO varistors in the future.he future.uture.he future.

• Asian-Australasian Journal of Animal Sciences
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• 제14권5호
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• pp.624-630
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• 2001

Two experiments on the effects of molasses additive on cassava tops silage quality to its feed intake and digestibility by growing Holstein$\times$local crossbred heifers were carried out. Sixteen plastic bags of one meter diameter and two meters length were allocated in a $2{\times}2$ factorial design with four replicates in the ensiling study, with and without the molasses additive and with two storage times (2 and 3 months). The silage produced in the first experiment was used in the feed intake and digestibility study. Six crossbred Holstein heifers, 160-180 kg live weight, were randomly allocated in a $3{\times}2$ change-over design to three treatments: Guinea grass ad libitum, 70% of grass ad libitum with a supplement of non-molasses cassava silage ad libitum, and 70% of grass ad libitum with a supplement of molasses cassava silage ad libitum. Ensiling was shown to be a satisfactory method for preservation of cassava tops. The HCN content was significantly reduced from $840mg\;kg^{-1}$ to 300 or $130mg\;kg^{-1}$, depending on storage period. The tannin content was not significantly changed. Molasses additive resulted in lower pH, Crude Protein (CP), NDF and higher DM content but did not otherwise affect chemical composition. The voluntary feed intake per 100 kg live weight of the heifers was 2.59, 2.65 and 2.91 kg DM of Guinea grass, non-molasses cassava tops silage and molasses cassava tops silage diet, respectively. Crude protein intake was significantly improved in the cassava tops silage diets. The apparent digestibility of DM, OM, CP, NDF and ADF decreased with the silage supplement diets. No significant difference in digestibility was found between the non-molasses and molasses silage diets. The digestibility coefficient of DM, OM, CP, NDF, ADF in non-molasses cassava tops silage and molasses cassava tops silage was 49.4, 52.1, 45.81, 36.6, 27.7 and 49.7, 51.9, 47.55, 28.1, 19.5, respectively. It is concluded that cassava tops can be preserved successfully by ensiling and that cassava tops silage is a good feed resource for cattle.

• 한국유기농업학회지
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• 제25권3호
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• pp.569-586
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• 2017

We inoculated a spent mushroom substrate from Flammulina velutipes (SMSF) with a microbial additive and assessed the effects on chemical composition, ruminal fermentation parameters, and total-tract nutrient digestibility. In Exp. 1, three cannulated Hanwoo steers were used in an in situ trial to determine the degradation kinetics of dry matter (DM) and crude protein (CP). In Exp. 2, three Hanwoo steers were randomly assigned to experimental diets according to a $3{\times}3$ Latin square for a 3-week period (2 weeks for adaptation and 1 week for sample collection). Experimental diets included the control diet (3.75 kg/d formulated concentrate mixture + 1.25 kg/d rice straw), SMSF diet (3.19 kg/d formulated concentrate mixture + 1.25 kg/d rice straw + 0.56 kg/d SMSF), and inoculated SMSF (ISMSF) diet (3.19 kg/d formulated concentrate mixture + 1.25 kg/d rice straw + 0.56 kg/d ISMSF). The chemical composition of ISMSF did not differ from that of SMSF. Microbial additive inoculation decreased pH (P<0.05) and improved preservation for SMSF. The percentages of DM, neutral detergent fiber (NDF), and acid detergent fiber (ADF) in ISMSF were slightly lesser than those in SMSF. Ruminal fermentation characteristics and total-tract nutrient digestibility were not affected by diet. Overall, microbial additive inoculation improved preservation for SMSF and may allow improved digestion in the rumen; however, the total digestible nutrients (TDN) of SMSF and ISMSF diets were slightly lesser than the control diet. The ISMSF can be used as an alternative feedstuff to partially replace formulated concentrate feed.

• Fisheries and Aquatic Sciences
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• 제23권4호
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• pp.7.1-7.8
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• 2020

Background: To minimize the use of antibiotics and to obtain a more sustainable fish culture and aquaculture industry, development of alternative natural source of immunostimulant to replace antibiotic in aquafeed is highly needed. Objective: Dietary inclusion effect of yacon (YC), ginger (GG), and blueberry (BB) on growth, body composition, and disease resistance of black rockfish against Vibrio anguillarum was compared to ethoxyquin (EQ). Methods: Four hundred eighty juvenile (an initial weight of 4.2 g) fish were randomly distributed into 12 of 50 L flowthrough tanks (forty fish per tank). Four experimental diets were prepared; the control (Con) diet with 0.01% EQ inclusion, and YC, GG, and BB diets at 1% each additive inclusion. Each additive was included into the experimental diets at the expense of wheat flour. Each diet was assigned to triplicate tanks of fish and hand-fed to satiation twice daily for 8 weeks. At the end of 8-week feeding trial, 20 fish from each tank fish were artificially infected by intraperitoneal injection with 0.1 mL of culture suspension of pathogenic V. anguillarum containing 3.3 × 10⁶ cfu/mL respectively. Fish were monitored for the following 8 days after V. anguillarum infection and dead fish were removed every 6 h for the first 4 days and 12 h for the rest of the study. Results: Weight gain, specific growth rate (SGR), and feed efficiency ratio (FER) of fish fed the YC diet was higher than those of fish fed all other diets. However, feed consumption, protein efficiency ratio, and protein retention was not affected by dietary additive. Moisture, crude protein, and crude lipid content of the whole body of fish were affected by dietary additive. Analysis of the Kaplan-Meier survival curves showed that survival of fish fed the YC, BB, and GG diets was higher than the Con diet. Conclusion: Oral administration of YC can improve not only weight gain, SGR, and FER of black rockfish, but lower mortality of rockfish at occurrence of V. anguillarum.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 제35회 춘계학술대회
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• pp.111-119
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• 2002

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1071-1074
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• 2006

Fabrication and investigation of composite made of graphite, SiC, mullite and aluminum as the additive are the aim of this project. Aluminum acts as an anti-oxidant. SiC is a non-metallic anti-oxidant that increases composite strength. Different compositions with influent percents of aluminum have been selected to determine product specifications by XRD, SEM and STA methods. Results show that the composition of 40wt% graphite-20% SiC- 20% mullite-20% aluminum is a more robust and occurs at elevated temperatures than other graphite combustion composites.

• 한국가금학회지
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• 제48권2호
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• pp.51-58
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• 2021

지방산 조성은 고기의 풍미에 영향력 있는 중요한 경제 형질 중 하나이며, 다양한 유전자들의 효과가 알려져 있다. 본 연구는 한국 재래닭의 지방산 조성에 유의적인 영향을 미치는 것으로 조사된 6개의 후보 유전자들(DEGS1, ELOVL6, FABP3, FABP4, FASN, SCD)의 51개 SNP 조합에 대한 추가적인 분석결과로, 선행연구를 통하여 확인된 SNP 조합들이 가지는 상위성 효과에 대하여 조사하였다. 본 연구를 통하여 매우 다양한 유형의 SNP 조합들이 한국 재래닭의 지방산 조성에 영향을 미치는 것으로 확인되었으며, 추후에 지방산 조성과 같은 다유전자성 형질들을 실제 육종 프로그램에 활용하기 위해서는 이러한 분석이 이루어져야 될 것으로 생각된다. 본 연구 결과는 한국 재래닭의 육질, 특히 지방산 조성의 개선을 위한 유전학적인 정보를 제공할 수 있을 것으로 생각된다.