• 한국전기전자재료학회논문지
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• 제27권1호
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• pp.14-17
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• 2014

In this study, lead-free Piezoelectric $(Na_{0.47}K_{0.47}Sr_{0.03}Ca_{0.03})(Nb_{0.94}Ti_{0.06})O_3$-0.1 $MnO_2$ ceramics were fabricated using mixed oxide method and the effects of various sintering temperature on the structural and electrical properties were investigated. For the $(Na_{0.47}K_{0.47}Sr_{0.03}Ca_{0.03})(Nb_{0.94}Ti_{0.06})O_3$-0.1 $MnO_2$ (NKN-SCT-$MnO_2$) ceramics sintered at temperatures of $1,025{\sim}1,100^{\circ}C$. The results indicated that all specimens were perovskite single phase formation without any second phase. It has been shown that relative density is increased to increasing sintering temperature. When the sintered temperature at $1,075^{\circ}C$, highest sintered density and maximum value of $4.45g/cm^3$. Average grain size is increased to increasing sintering temperature. The electromechanical coupling factor, dielectric constant, dielectric loss, d33 and curie temperature at the sintering temperature $1,075^{\circ}C$ of NKN-SCT-$MnO_2$ specimens were 0.22, 511, 0.033, 103 and $380^{\circ}C$, respectively.

• Asian-Australasian Journal of Animal Sciences
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• 제15권9호
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• pp.1334-1340
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• 2002

A 4 week experiment was designed to study the effects of replacing corn with Chinese brown rice or adding different amylase in brown rice basal diet on growth performance and apparent fecal digestibilities of nutrients in growing pigs. One hundred and eight cross-bred pigs (Duroc${\times}$Landrace${\times}$Large White), weighing an average of $18.35{\pm}0.12kg$, were randomly assigned to 6 treatments with 6 replications per treatment. Diet in treatment 1 was corn-soybean meal basal diet, and in treatment 2, 3 and 4, corn was replaced by brown rice on rates of 33.3%, 66.7% and 100% respectively on the basis of treatment 1. And diets in treatment 5 and 6 were similar to treatment 4 except two kinds of amylases, glucoamylase and ${\alpha}$-amylase, were added respectively. The brown rice used in this experiment was husked from one kind of early, long grain, non-glutinous rice (ELGNR, indica rice) in southern China. The results indicated that there was a slight improvement in growth performance of pigs in brown rice treatments (p>0.05). The blood urea nitrogen value in treatment 2 was lower than that in treatment 1 (p<0.05). The differences of apparent fecal digestibilities of most nutrients were significant (p<0.05) except CP. Digestibilities of GE, OM and DM in treatment 4 were the best and digestibility of crude fat in treatment 5 appeared best (p<0.05). Contrast results between treatment 1 and treatment 2 to 4 indicated that the digestibility of GE, OM and DM increased significantly with the replacing rates of brown rice (p<0.05). Contrast results between treatment 4 and 5 indicated that adding glucoamylase in brown rice diet increased growth performance slightly (p>0.05) but not for digestibilities. This experiment shows a positive effect of brown rice on growth performance, especially on nutrient digestibility.

• Asian-Australasian Journal of Animal Sciences
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• 제25권8호
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• pp.1132-1137
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• 2012

Objective of this experiment was to evaluate the effect of partial substitution of barley grain with bread by-product (BB) on performance of Awassi ewes and their lambs. Forty Awassi ewes rearing single lambs were randomly allotted into four experimental diets containing various levels of BB. The experimental diets contained 0 (BB0), 10 (BB10), 15 (BB15), and 20% (BB20) of BB on dietary dry matter (DM). The study lasted for eight weeks, in which the first week was used as an adaptation period and seven weeks of data collection. Ewes and their lambs were penned individually where they were fed their lactating diets ad libitum. Ewes and lambs body weights were measured at the beginning and at the end of the experiment. However, milk production and composition were evaluated biweekly. Feeding BB had no effect (p>0.05) on dry matter (DM), organic matter (OM), and crude protein (CP) intakes. However, neutral detergent fiber (NDF) intake was the lowest (p<0.05) for the BB20 and BB15 diets followed to BB10 diet (i.e., 640, 677, 772 g/d, respectively) while the highest NDF intake was for the BB0 diet (i.e., 825 g/d). Similarly, NDF intake decreased linearly (p<0.001) as the BB content increased. Acid detergent fiber (ADF) intake was highest (p<0.05) for the BB0 and BB10 diets (425 and 416 g/d, respectively) followed by the BB15 and BB20 diets (359 and 342 g/d, respectively). Moreover, a linear (p<0.001), quadratic (p = 0.04), and cubic (p = 0.04) effects were observed in ADF intake among diets. Nutrient digestibility was similar among different diets. Bread by-product had no effect (p>0.05) on ewes body weight change and on lamb performance (i.e., weaning body weight and average daily gain). Similarly, no differences (p>0.05) were observed either in milk production or composition by the BB substitution. Inclusion of BB reduced feed cost by 9, 14, and 18% for the BB10, BB15, and BB20 diets, respectively. No differences were observed in milk efficiency (DM intake: milk production; p>0.05) among diets. However, cost of milk production ($US/kg milk) was the lowest (p<0.05) in the diet containing BB20. Results of the present study indicate that feeding bread by-product up to 20% of the diet DM had no effect on performance of Awassi ewes and their lambs and reduced feed cost.

• Asian-Australasian Journal of Animal Sciences
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• 제22권7호
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• pp.993-1004
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• 2009

Three experiments were conducted to determine the effects of non-ionic surfactant (NIS) supplementation on ruminal fermentation, nutrient digestibility and performance of beef steers fed high-roughage diets. The objective of experiment 1 was to investigate the effects of NIS supplementation on in vitro ruminal fermentation of cultures administered with corn and barley as grain substrate and rice straw and timothy hay as roughage substrate. The in vivo ruminal fermentation, nitrogen balance and digestibility of nutrients were also examined with steers fed a high-roughage diet in experiment 2. The aim of experiment 3 was to determine the responses to NIS of growing steers fed a high-roughage diet. In experiment 1, ammonia nitrogen concentration for NIS supplementation was higher (p<0.05) than for the control with all substrates. However, concentrations of total volatile fatty acid (VFA), acetate, butyrate and valerate of the incubated roughage substrates, rice straw and timothy hay, were higher (p<0.05) for NIS supplementation than for the control whereas VFA concentrations in the cultures of corn and barley were unaffected. These results indicated that effects of NIS on ruminal fermentation are diet dependent, specifically on roughage sources. In experiment 2, ruminal pH of steers supplemented with NIS was lower (p<0.05) than the control. Ruminal concentrations of ammonia nitrogen, acetate, total VFA and urinary concentrations of purine derivatives were increased (p<0.05) by NIS supplementation. In experiment 3, supplementation of NIS increased (p<0.05) intakes of total feed and corn silage, average daily gain, and feed efficiency of growing steers although they varied depending on supplementation level. Due to the roughage-specific feature of NIS effects, NIS appears to enhance ruminal fermentation of fibrous parts of feeds and, consequently, performance of steers fed a high-roughage diet.

• Asian-Australasian Journal of Animal Sciences
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• 제30권11호
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• pp.1563-1567
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• 2017

Objective: The influence of substituting steam-flaked corn (SFC) for dry rolled corn (DRC) on feedlot cattle growth performance and dietary net energy when cattle are allowed either ad libitum or 2-h restricted access to the finishing diet was evaluated. Methods: Treatment effects were tested using 96 crossbred steers ($251{\pm}2kg$) during the initial 56 d of the finishing phase. Cattle were blocked by weight and randomly assigned within blocks to 16 pens (4 pens/treatment). Bunk space was sufficient (41 cm/head) to allow all steers access to the feed bunk at the same time. Treatments consisted of two finishing diets containing (dry matter basis) 77.1% corn grain processed by dry rolling (density = 0.50 kg/L) or steam flaking (density = 0.36 kg/L). Cattle were fed twice daily at 06:00 and 14:00 h, allowing for approximately 5% residual. In the case of restricted feeding, steers were allowed access to feeders for 1 h following each feeding, after which residual feed was withdrawn. Results: There were no treatment interactions on dry matter intake (DMI), average daily gain (ADG), gain efficiency (G:F), or dietary net energy (NE). Restricting feed access time reduced (p<0.01) feed intake, and hence, ADG. Substitution of SFC for DRC increased (p<0.01) ADG, feed efficiency (G:F), and estimated dietary NE, without affecting DMI. Based on tabular net energy of maintenance ($NE_m$) value (2.18 Mcal/kg) for DRC, the estimated $NE_m$ value for SFC using the replacement technique, averaged 2.44 Mcal/kg; an improvement of 10.7%. The ratio of observed-to-expected dietary NE was not affected by feed access time. Conclusion: Substitution of SFC for DRC in finishing diets for feedlot cattle enhanced ADG, gain efficiency, and the NE value of the diet. Although restriction of feed access time depressed DMI and ADG, it did not affect the comparative benefit of steam flaking toward enhancement of ADG, G:F, and dietary NE.

• 한국재료학회지
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• 제15권6호
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• pp.413-418
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• 2005

Perovskite $Pb(Ni_{1/3}Nb_{2/3})O_3-Pb(Zr,Ti)O_3[PNN-PZT]$ ceramics were synthesized by conventional ceramic processing technique. In order to modify piezoelectric properties for sensor application in this system, NiO addition was considered to provide $Ni^{+2}$ as an acceptor, which was known to occupy with B site in the structure. The effect of NiO addition up to $8\;mol\%$ on the following piezoelectric properties as well as sintering properties was investigated. When NiO added more than $1\;mol\%$, average grain size was decreased and second phase was found to form. Moreover, the second phase caused decrease in relative dielectric constant $(\varepsilon_{33}T/\varepsilon0)$, electro-mechanical coupling factor $(k_p)$, and piezoelectric charge constant $(d_{33})$, while increasing mechanical quality factor $(Q_m)$. When $1\;mol\%$ NiO was added, density, dielectric properties and piezoelectric properties were abruptly increased.

• 한국재료학회지
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• 제10권7호
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• pp.464-470
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• 2000

스폰지 티타늄으로부터 수산호-탈수소화법(HDH)법으로 제조된 부말에 고상탈산법(DOSS)을 적용시켜 만든 산소 농도 범위 1980~8450 ppm, 입경 $25\mu\textrm{m}$ 내외의 불규칙 티타늄 분말의 성형 및 소결성을 조사하였다. 250MPa의 가압력으로 냉간압축성형한 결과, 성형밀도는 69.0%~62.3% 범위 내에 있었고 산호함량 증가에 따라 직선 또는 완만하게 감소하였다. 이러한 경향은 티타늄 분말의 경도변화로 설명할 수 있었다. 최고 7%까지의 차이를 보였던 성형밀도에도 불구하고 $1100^{\circ}C$에서 2시간동안 소결한 결과, 산소함량에 무관하게 소결밀도는 90.5$\pm$0.5%를 보였으며, 결정립의 크기는$60\mu\textrm{m}$ 내외의 균일하였고, 가공크기 및 분포도 유사하였다. 소결체의 경도에 미치는 산소의 영향은 실험범위 내에서 VHN(sintered)=135.5+64.3$\times$(wt%$O_2$)의 실험식을 얻었다. 소결체의 파단면 관찰한 결과, 연성에서 취성파괴로의 천이는 소결체에의 산소함량이 2987~5582ppm 사이에서 일어나는 것으로 나타났다.

• 한국제4기학회지
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• 제7권1호
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• pp.69-91
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• 1993

한반도 서해안의 금강하구와 연안 조간대 및 황해 동부 대륙붕에서 채취된 76개의 표층퇴적물 시료에 대하여 Al, Fe, Na, K, Mg, Ca, Ti, Mn 등 9개 주성분원소와 Sr, Ba, V, Cr, Co, Ni, Cu, Zn 등 8개 미량 금속원소, 그리고 유기탄소 함량과 탄산염 함량 등의 화학성분을 분석하여 퇴적물의 지구화학적 특성을 연구하였다. 분석된 원소들의 함량은 K과 Ba을 제외하곤 지각의 평균함량에 비해 전반적으로 낮게 나타났으며, K과 Ca 등을 제외한 대부분 원소의 함량이 퇴적물 입도와 관련성을 보였다. 연구지역 내에서 퇴적물의 화학성분 함량은 퇴적환경 이나 위치에 따라 서로 다른 특성을 나타내었으며, 세립퇴적물의 경우 금강하구의 퇴적물에서 상대적으로 높은 Mn, Co, Ni의 함량이, 그리고 황해중앙이토에서는 높은 Fe, Na, K, Mg, Ca, V의 함량이 특징으로 나타났다. 한편. 원소함량을 Al함량으로 나눈 함량비의 공간적 분포로부터는 황해중앙이토에서 Fe, Mg, V, Ni, Cu, Zn 등이, 그리고 한반도 연안에서는 K, Mn, Ba, Sr 등이 높아지는 경향이 나타났다. 이렇게 분석된 세립퇴적물 지화학 특성의 지역적 차이, Al에 대한 함량비의 분포경향, 지각 평균함량을 기준한 원소의 농축비, 특정 광물분포의 영향, 오염의 가능성 등 제반 사항들을 종합적으로 검토하여 본 연구지역에 유입되는 한반도 기원 세립물질과 중국 기원 세립물질을 구분할 수 있는 지화학적 지표로서 각각 Mn과 Mg-V이 제시되었다.

• 한국수산과학회지
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• 제43권6호
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• pp.723-734
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• 2010

To understand temporal variations in geochemical characteristics of intertidal surface sediments around Byeonsan Peninsula (in the middle of the western coast, Korea) after the construction of Saemanguem dyke, the sedimentation rate and various geochemical parameters, including mean grain size (Mz), water content (WC), ignition loss (IL), chemical oxygen demand (COD), and acid volatile sulfide (AVS), were measured along four transects (A.D lines) at monthly intervals from February 2008 to March 2009. The average monthly sedimentation rate ranged from -5.3 to 3.8 mm/month (mean $-0.8{\pm}2.7\;mm$/month), which showed an erosion-dominated environment in the lower part of the intertidal zone. In addition, surface sediments were eroded in summer and autumn, but were deposited in spring and winter. The Mz of surface sediments ranged from -0.8 to $3.4{\varnothing}$ (mean $2.8{\pm}0.5{\varnothing}$), indicating that the surface sediments consist of coarser sediments (sand and slightly gravelly sand). The Mz of surface sediments did not show large monthly and/or seasonal variations, although the sedimentation rates of surface sediment showed large seasonal variation. This may be due to lateral shifting and effective dispersion of surface sediments by wind, tide, and longshore current. The concentrations of IL and COD in the surface sediments ranged from 0.2 to 2.9% (mean $1.4{\pm}0.4%$) and from 0.2 to $18.5\;mgO_2$/g-dry (mean $3.9{\pm}3.4\;mgO_2$/g-dry), respectively, which were slightly higher in spring than in the other seasons. This may be related to spring blooms of phytoplankton in seawater and/or benthic microalgae in surface sediments. On the other hand, no AVS concentrations were detected in surface sediments at any of the sampling stations during the study period.

• 한국작물학회지
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• 제57권2호
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• pp.166-170
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• 2012

본 연구는 신간척지에서 벼 기계이앙재배시 염 피해가 적으면서 안정적인 쌀수량 확보를 위하여 모 종류를 어린모, 치묘, 중묘, 폿트묘로 새로 조성된 간척지인 새만금 계화포장에 이앙하여 수행한 내용을 요약하면 다음과 같다. 1. 2년 평균 토양염농도는 이앙전 0.16%에서 환수후 이앙 직후에는 0.04%로 낮아졌다. 2. 모 종류별 출수기는 폿트묘 이앙이 8월 14일인데 비해중묘이앙은 2일, 치묘이앙은 3일, 어린모이앙은 5일 늦게 출수되었다. 3. 도복관련형질에서 중묘이앙이 도복지수가 가장 높아 포장도복 역시 중묘이앙이 반도복 정도 되었다. 4. 수량구성요소를 보면 이앙모 종류별 등숙비율과 현미천립중은 비슷하였고, 주당수수는 치묘>어린모>폿트묘>중묘이앙 순으로 많았으며, 쌀수량은 어린모=치묘>폿트묘>중묘이앙 순으로 많았다. 5. 이앙모 종류별 쌀 품질에서 완전립비율은 치묘>중묘=어린모>폿트묘 순으로 높았고, 아밀로스함량과 단백질 함량은 이앙모 종류간 차이가 없었다. 결론적으로 새로 조성된 간척지에서 벼를 기계이앙재배할 때 안정적인 쌀 수량 확보를 위한 적정 이앙모는 어린모와 치묘가 적합하다고 판단된다.