• 한국초지조사료학회지
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• 제18권3호
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• pp.205-216
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• 1998

유휴논토양에서 reed canary grass를 재배하였을 때 액상구비의 단기간(3년간) 시용효과를 조사하였으 며, 그 결과를 요약하면 다음과 같다. 1. 모든 예취빈도에서 1993년의 건물수량이 다른 재배년도보다 많았다. 2. 액상구비의 시용수준별 평균 건물수량은 3회 예취구의 360 kg $ha^{-1}\;yr^{-1}$ 수준에서 13.10 ton $ha^{-1}$, 4회 예취구의 360~480 kg $ha^{-1}\;yr^{-1}$ 수준에서 12.50~12.83 ton $ha^{-1}$ 5회 예취구의 450~600 kg $ha^{-1}yr^{-1}$ 수준에서 12.52~12.56 ton $ha^{-1}$로 유의하게 많았다. 3. 건물생산 효율(kg DM $kg^{-1}$ N)은 액상구비의 시용수준과 예취빈도가 높을수록 낮아지는 경향이었다. 3회 예취구의 90 kg $ha^{-1}\;yr^{-1}$ 수준에서 15.2 kg, 4회 예취구의 120 kg $ha^{-1}\;yr^{-1}$ 수준에서 19.8 kg, 5회 예취구의 150 kg $ha^{-1}\;yr^{-1}$ 수준에서 10.0 kg을 나 내어 건물생산 효율이 가장 높았다. 4. 예취번초별 상대수량은 3회 예취구의 2번초가 38.1%, 4회 예취구의 3번초가 41.8%, 5회 예취구의 4번초가 30.1%로 가장 높았다. 5. 액상구비의 경제적 시용수준의 범위는 연간 평균 3회 예취구에서 261.0~304.6 kg $ha^{-1}\;yr^{-1}$, 4회 예취구에서 205.8~302.9 kg $ha^{-1}\;yr^{-1}$, 5회 예취구에서 303.8~354.4 kg $ha^{-1}\;yr^{-1}$로 추정되었고 이때 얻어지는 한계수량은 3회 예취구에서 11.5~12.1 ton $ha^{-1}$, 4회 예취구에서 10.4~11.5 ton $ha^{-1}$, 5회 예취구에서 11.1~11.6 ton $ha^{-1}$으로 추정되었다. 6. 예취번초의 경제적 시용수준의 범위는 3회 예 취구에서 67.9~95.0 kg $ha^{-1}$, 4회 예취구에서 14.3~119.8 kg $ha^{-1}$, 5회 예취구에서 50.9~125.2 kg $ha^{-1}$였다. 7. 건물수량에 대한 액상구비의 시용효과가 가장 높았던 예취빈도는 3회 예취구였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.385-388
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• 1997

As the environmental regulations become stricter, new machining technologies are being developed which takes envi ronmenta 1 aspects into account . Since cut t ing oi I has some impact on environment. many researches are being carried out to minimize the use of cutting oi I. The methods for minimizing cutting oil usage includes the following techniques: I ) Cooling of tools and work piece. 2) Useage of compressed cooling air for the removal of chip. 3) Minimal useage of environment-friendly vegetable cutt:ngoiI for lubrication between chip and tools. Since the turning machine is continuous, tools are under constant thermal load and tool wear increases as the lubricative performance degrades. Also surface roughnesses have a direct influence on turning. In order to examine the characteristics of turningmachining, this work investigates experimentally the degree of tool wear and characteristics of surface roughness in relation to machining conditions, supply methods, and cooling methods.

• 한국초지조사료학회지
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• 제16권2호
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• pp.139-146
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• 1996

An experiment was canied out to investigate how to effect the application of nitrogen, phosphate and potassium on the vegetation and dry matter yield in the mixed sward of Ladino clover and crabgrass(Digitaria sanguinalis [L.] Scop.). The experimental sward was consisted of eight plots of non-application, K, P, PK, N, NK, NP and NPK. These plots were sown with seeds mixture of Ladino clover 5.0kg/ha and crabgrass 17.5kg/ha on 17 April 1976 in the forage experimental field of Kangwon National University, Chunchon, Korea, and were cut three times from 6 July to 4 October 1976.

• Journal of information and communication convergence engineering
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• 제5권3호
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• pp.215-218
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• 2007

In this paper, amorphous semiconductor and insulator thin film are etched using reactive ion etcher. At that time, we experiment in various RIE conditions (chamber pressure, gas flow rate, rf power, temperature) that have effects on quality of thin film. The using gases are $CF_4,\;CF_4+O_2,\;CCl_2F_2,\;CHF_3$ gases. The etching of a-Si:H thin film use $CF_4,\;CF_4+O_2$ gases and the etching of $a-SiO_2,\;a-SiN_x$ thin film use $CCl_2F_2,\;CHF_3$ gases. The $CCl_2F_2$ gas is particularly excellent because the selectivity of between a-Si:H thin film and $a-SiN_x$ thin film is 6:1. We made precise condition on dry etching with uniformity of 5%. If this dry etching condition is used, that process can acquire high yield and can cut down process cost.

• 한국생산제조학회지
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• 제19권3호
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• pp.381-387
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• 2010

This paper presents a study of the influence of fixed pressure in turning. The effect of roundness error and diameter deformation were studied with respect to the fixed pressure applied inside the cylindrical work piece made by boring tool in CNC lathe. The boring tool used in this study is a tungsten carbide coated. The material of workpiece is SM45C and the machining method is dry cutting. Cutting conditions as cutting speed, feed rate and depth of cut are constant. Finally, the change of fixed pressure had influence on the roundness error and diameter deformation.

• 한국초지조사료학회지
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• 제7권2호
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• pp.71-78
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• 1987

본 실험은 파종방법, 배수화도 및 여름철 예취관리가 오차드그라스 채초지의 목장건물수량, 고사물량, 초지의 잡초발생 및 피복율에 미치는 영향을 조사하기 위하여 심험설계는 주구를 조파와 산파로 하고 세구를 배수랑호구와 배수불랑구로 하였으며, 세세구는 장마전 예취구와 장마후 예취구를 두어 세세구 배치 3반후으로 하여 1983년 9월부터 1984년 10월까지 실시하였던바 얻어진 결과는 다음과 같다. 1. 초지의 목장건물수량은 1회 예취시에는 처리간에 차이가 없었으나 2회와 3회 예취시에는 장마전 예취구가 장마후 예취구에 비하여 수량이 높았고 ($P{\le}0.01$) 3회예취시에는 조파구가 산파구에 비하여 수량이 높았다. $P{\le}0.05$. 2. 목장의 고사물량은 2회예취시에만 발생하였는데 장마전 예취구에서는 발생하지 않았는데 반해 장마후 예취구에서는 배수랑호구와 배수불랑구에서 총 목장수량에 대하여 각각 24%와 35%의 고사물량이 발생하였다. 3. 잡초발생은 1회, 2회예취시에는 거의 없었으나 3회 예취시부터 다량발생하였는데 산파구가 조파구에 비하여 높았고 ($P{\le}0.05$) 장마후 예취구가 장마전 예취구에 비하여 월등이 높았다. $P{\le}0.01$. 4. 목장의 피복율은 1회 예취율에는 거의 100%로 차이가 없었으나 2회 및 3회 예취후에는 장마전 예취구가 장마후 예취구에 비하여 매우 높은 수준을 보였으며 ($P{\le}0.01$) 조파는 산파에 비하여 높았으나 유의차는 없었다. 또한 각 처리구의 월동전식생 피복율은 장마전 예취구는 장마후 예취구에 비해 오차드그라스의 구성비율은 높았고 잡초 및 나지의 구성비율은 낮았다. 5. 본 실험결과로 미루어보아 오차드그라스채초지의 2회 예취는 장마전에 실시하고 조파를 함으로서 잡초발생을 크게 줄일 수 있을 것으로 생각된다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제10권6호
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• pp.68-74
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• 2005

고농도 비소 오염토양에 대한 fold규모 연속 토양세척공정의 적용 가능성을 평가하기 위해 경상남도 D광산 광미 혼합토양에 대하여 적용하였다. 초기 비소오염 농도는 $321\pm32 mg/kg$ dry soil 이었으며 pilot규모 실험에서 도출된 기본 운전조건을 적용한 결과, 세척된 토양의 잔류 비소농도는 2.03 mg/kg dry soil로서 $99\%$의 높은 제거효율을 나타내었다. 경제성 및 효율성을 개선하기 위하여 세척제의 농도, cut-off size, 진탕비를 조절하며 운전한 결과, 토양세척 공정 운전시 원활한 운전관리와 처리단가 등을 고려한 최적의 운전조건은 1) 각 단계의 세척제 농도 0.2M HCl-1.0M HCl-1.0M NaOH, 2) cut-off size 0.15mm(sieve $\sharp$100), 3) 진탕비 1:3으로 처리한 결과 세척된 토양의 잔류 비소농도는 2.03mg/kg이었으며 세척유출수 처리에서는 형성된 Hoc의 과포화로 인한 침전방해가 발생하지 않는 pH 6이 (33 ppb) 최적의 처리조건으로 판단되었다. 최종 배출된 청정자갈 및 토양, 티ter cake에 대하여 TCLP법을 적용한 용출실험 결과, 각각 1.04, ND, 0.07 mg/L 모두 용출비소 농도기준(5 mg/L)을 만족하며, 탈수슬러지의 함수율$(48\%)$도 폐기물관리법의 슬러지 수분함량 기준$(85\%)$을 만족하여 매립처리가 가능함을 알 수 있었다. 따라서 본 연구의 field 규모 연속 토양세척공정은 고농도 비소 오염부지의 정화를 위한 기술로 적용 가능함을 확인할 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제33권8호
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• pp.1242-1251
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• 2020

Objective: The 3×3 factorial arrangement was used to investigate if either high water-soluble carbohydrates (WSC) cultivars or suitable time of day that the grass cut could improve nutrient values and in vitro fermentation characteristics. Methods: The 3 cultivars were mowed at 3 diurnal time points and included a benchmark WSC ryegrass cultivar 'Premium', and 2 high WSC cultivars AberAvon and AberMagic, which contained, on average, 157, 173, and 193 g/kg dry matter (DM) of WSC, and 36.0, 36.5, and 34.1 g/kg DM of N during 7th regrowth stage, respectively. The fermentation jars were run at 39℃ with gas production recorded and sampled at 2, 5, 8, 11, 14, 17, 22, 28, 36, and 48 h. The rumen liquid was collected from 3 rumen fistulated cows grazing on ryegrass pasture. Results: High WSC cultivars had significantly greater WSC content, in vitro DM digestibility (IVDMD) and total gas production (TGP), and lower lag time than Premium cultivar. Methane production for AberMagic cultivar containing lower N concentration was marginally lower than that for AberAvon and Premium cultivars. Grass cut at Noon or PM contained greater WSC concentration, IVDMD and TGP, and lower N and neutral detergent fiber (NDF) contents, but CH₄ production was also increased, compared to grass cut in AM. Meanwhile, the effects of diurnal cutting time were influenced by cultivars, such as in vitro CH₄ production for AberMagic was not affected by cutting time. The IVDMD and gas production per unit of DM incubated were positively related to WSC concentration, WSC/N and WSC/NDF, respectively, and negatively related to N and NDF concentrations. Conclusion: These results imply either grass cut in Noon or PM or high WSC cultivars could improve nutrient values, IVDMD and in vitro TGP, and that AberMagic cultivar has a slightly lower CH₄ production compared to AberAvon and Premium. Further study is necessary to determine whether the increase of CH₄ production response incurred by shifting from AM cutting to Noon and/or PM cutting could be compensated for by high daily gain from increased WSC concentration and DM digestibility.

• ALGAE
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• 제18권2호
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• pp.129-134
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• 2003

In order to examine the effects of deep seawater (mesopelagic water in the broad sense) on the growth of macroalgae, the growth and nutrient uptake (nitrate and phosphate) of Ulva sp. (Ulvophyceae, Chlorophyta) were investigated by cultivation in deep seawater (taken from 687 m depth at Yaizu, central Japan, in August 2001), surface seawater (taken from 24 m depth), and a combination of the two. Culture experiments were carried out in a continuous water supply system and an intermittent water supply system, in which aerated 500-mL flasks with 4 discs of Ulva sp. (cut sections of ca. 2 $cm_2$) were cultured at 20$^{\circ}C$ water temperature, 100 $\mu$mol photons $m^{-2}{\cdot}s^{-1}$ light intensity, and a 14:10 light:dark cycle. Nutrient uptake by Ulva sp. was high in all seawater media in both culture systems. The frond area, dry weight, chlorophyll a content, dry weight per unit area, and chlorophyll a content per unit area of Ulva sp. at the end of the experimental period were the highest in deep seawater and the lowest in surface seawater in both culture systems. These values, except for dry weight per unit area and chlorophyll a content per unit area, for each seawater media in the intermittent water supply system were higher than those in the continuous water supply system. We conclude that not only deep seawater as the culture medium but also the seawater supply system is important for effective cultivation of macroalgae.

• 한국초지조사료학회지
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• 제11권2호
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• pp.97-101
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• 1991

This experiment was carried out to determine the effect of pure mineral nitrogen fertilization on dry matter yield and the amounts of advisable mineral nitrogen on grassland according to its age at the "Federal Institue for Agriculture in the Alps" in Austria. The results obtained were as follows: 1. With only PK-fertilizing average dry matter yields per year were progressively declined during the period of the studies. Compared with the relatively younger grassland(1st-5th year) the DM-yields were decreased by 35% in older grassland (11th-final year). 2. Due to the less reduction of DM-yields by mineral nitrogen application according to the age of grassland. With N-fertilizing the reduction of DM-yields in relatively older grassland was less than that of younger grassland by 11-21%. 3. At 4-and 5-cut systems the nitrogen amounts for the highest marginal yield(the "most efficient" Ndressing rate) per ha and year were distinctly declined in the relatively older grassland. 4. Required efficiencies of mineral nitrogen were not influenced by the age of grassland.he age of grassland.