• 제목/요약/키워드: 15-nitrogen

검색결과 2,686건 처리시간 0.035초

Corrosion and Nanomechanical Behaviors of 16.3Cr-0.22N-0.43C-1.73Mo Martensitic Stainless Steel

  • Ghosh, Rahul;Krishna, S. Chenna;Venugopal, A.;Narayanan, P. Ramesh;Jha, Abhay K.;Ramkumar, P.;Venkitakrishnan, P.V.
    • Corrosion Science and Technology
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    • 제15권6호
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    • pp.281-289
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    • 2016
  • The effect of nitrogen on the electrochemical corrosion and nanomechanical behaviors of martensitic stainless steel was examined using potentiodynamic polarization and nanoindentation test methods. The results indicate that partial replacement of carbon with nitrogen effectively improved the passivation and pitting corrosion resistance of conventional high-carbon and high- chromium martensitic steels. Post-test observation of the samples after a potentiodynamic test revealed a severe pitting attacks in conventional martensitic steel compared with nitrogen- containing martensitic stainless steel. This was shown to be due to (i) microstructural refinement results in retaining a high-chromium content in the matrix, and (ii) the presence of reversed austenite formed during the tempering process. Since nitrogen addition also resulted in the formation of a $Cr_2N$ phase as a process of secondary hardening, the hardness of the nitrogen- containing steel is slightly higher than the conventional martensitic stainless steel under tempered conditions, even though the carbon content is lowered. The added nitrogen also improved the wear resistance of the steel as the critical load (Lc2) is less, along with a lower scratch friction coefficient (SFC) when compared to conventional martensitic stainless steel such as AISI 440C.

Optimization of main factors using response surface method for the enhanced production of hGM-CSF from transgenic Nicotiana tabacum cell suspension cultures

  • Lee, Ki-Yong;Lee, Sang-Yoon;Kim, Dong-Il
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2003년도 생물공학의 동향(XIII)
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    • pp.351-355
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    • 2003
  • Screening 실험을 통하여 결정된 주요인자인 sucrose, nitrogen, 배양온도로 인자의 최적수준을 결정하는 표면반응법중 하나인 Box-Behnken design을 수행하였다. 각 인자의 상관관계를 통하여 sucrose는 90 g/L, nitrogen은 41 mM, 온도는 $22^{\circ}C$가 최적수준으로 결정이 되었으며 확인실험을 통하여 대조구보다 세포생장이 증가하였을 뿐만 아니라 hGM-CSF의 생산도 약 2배 정도 증가되었음을 확인하였다. 이것은 고농도의 sucrose로 인해 배지내로의 hGM-CSF의 분비가 촉진되었기 때문이며 또한 저온으로 인해 분비된 hGM-CSF를 분해하는 protease 활성이 감소되었기 때문인 것으로 사료된다.

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질소시비 수준이 Italian Ryegrass의 질산염 축적에 미치는 영향 (Effects of Nitrogen Fertilization on Nitrate Accumulation in Italian Ryegrass)

  • 정완태;최기춘;윤창;송채은;전우복
    • 한국초지조사료학회지
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    • 제17권2호
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    • pp.135-140
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    • 1997
  • This study was conducted to investigate the effect of levels of nitrogen fertilizer on the nitrate accumulation in Italian ryegrass. Italian ryegrass was grown at the experimental field, College of Agriculture, Chonnam National University, Kwangju from September, 29, 1987 to June, 24, 1988. The experiment was arranged as a randomized complete block design with three treatment(2.5, 7.5 and 15kg-NIlOa). The results obtained are summarized as follow; Nitrate nitrogen content of the stem, leaves and whole was increased as increasing nitrogen fertilizer(P< 0.05). Total nitrogen content in the leaves was much higher than that of stem, and not significance among the levels of nitrogen fertilizer. Total water soluble carbohydrate content in stem was higher than that in the leaves and decreased after cutting as increasing nitrogen fertilizer(P < 0.05)

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액화질소에 의한 간흡충 피낭유충의 살충에 대한 연구 (Larvicidal Action of Liquid Nitrogen against. Metacercariae of Clonorchis sinensis)

  • 송수복
    • Parasites, Hosts and Diseases
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    • 제25권2호
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    • pp.123-128
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    • 1987
  • The author investigated the larvicidal action of liquid nitrogen against the metacercariae of Clonorchis sinensis, with an observation on the freshness and change of taste in the flesh of fishes. The results obtained were as follows: 1. The metacercariae in the mesh of Pseudorasbora parve, which were treated with liquid nitrogen ($-192^{\circ}C$), were not killed within 10 seconds, but completely killed over 30 seconds. In comparison, the metacercariae in the flesh of p. parka kept in a refrigerator ($-12^{\circ}C$) were killed only in 84% in 10-hour exposure group. 2. The freezing speed of fishes by liquid nitrogen was 4 min.(') and 15 seconds(") for Cyprinus carpio, 1'22" for Carassius carassius and only $30^{\circ}C$ for Pseudorasbora larva. 3. As for the freshness and taste of raw fresh water fishes, they were not deteriorated after the treatment with liquid nitrogen. 4. In animal infection experiment of C. sinensis metacercariae after freezing, they were found not infective after they were treated with liquid nitrogen. From the results, it is inferred that the treatment of fresh water fishes for longer than 30 seconds with liquid nitrogen is helpful to reduce the possibility of C, sinensis infection without alteration of the freshness and taste of fishes.

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혼합유박 시용량 및 시용시기가 토양환경과 미질에 미치는 영향 (Effect of Application Time and Rate of Mixed Expeller Cake on Soil Environment and Rice Quality)

  • 양창휴;류철현;김병수;박우균;김재덕;정광용
    • 한국토양비료학회지
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    • 제41권2호
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    • pp.103-111
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    • 2008
  • 벼 재배시 유기질비료에 의한 질소비료 대체를 위하여 혼합유박의 적정 시용량 및 시용시기를 구명코자 전북통에서 동진1호를 공시하여 2년 동안 시험한 결과를 요약하면 다음과 같다. 시험 후 토양화학성 중 유기물 함량은 표준시비에 비하여 혼합유박 기비 100%구에서 높은 반면에 총질소 함량은 가장 낮았으며 유효인산 함량은 혼합유박 대체 시용량이 적을수록 높았다. 또한 표준시비구에 비하여 혼합유박 시용구에서 유기물 함량이 높았고, 유효인산, 총질소 함량 및 양이온치환용량은 혼합유박 시용시기가 늦을수록 낮아지는 경향을 나타냈으며 치환성양이온은 큰 변화가 없었다. 토양 중 무기태질소 함량은 혼합유박 시용량이 많을수록 높은 경향으로 수확기 무기태질소는 기비 70%, 50% 시용구에서 거의 용출이 완료되었으며 질소 $110kg\;ha^{-1}$를 혼합유박으로 전량 기비로 시용하였을 경우 시비질소의 무기태질소 함량은 시용시기가 늦을수록 많았으나 생육후기로 갈수록 낮아지는 경향을 보였다. 생육시기별 SPAD 측정치는 표준시비에 비하여 혼합유박 대체 시용량이 많을수록 높은 경향을 나타냈고, 생육중기까지는 혼합유박 시용구에서 표준시비구보다 짙은 반면에 생육후기에는 기비 70%, 50% 시용구에서 옅었으며 혼합유박 시용시기가 늦을수록 생육전반에 걸쳐 짙은 경향을 나타냈다. 또한 시비질소 흡수량은 혼합유박 대체 시용량이 많을수록 많았고 성숙기에는 기비 50% 시용구에서 표준시비구보다 흡수량이 적었으며 질소이용률은 기비 70% 시용구에서 가장 높았다. 혼합유박 시용시기가 이앙 전 10~15일 시용구에서 시비질소 흡수량이 가장 많았고 시용시기가 빠를수록 적어졌으며 질소이용률도 같은 경향이었다. 쌀 수량은 표준시비구($5.18Mg\;ha^{-1}$) 대비 기비 50% 시용구에서는 대등하였으나, 기비 70%, 100% 시용구에서 수수 및 영화수 확보가 많아 4% 증수되었고, 유박 시용구에서 2~5% 증수되었으며 특히 이앙 전 15~10일 시용구에서 높았다. 또한 시용시기가 늦을수록 간장과 수장이 길었고 수수와 영화수확보가 많았으나 등숙비율은 낮아지며 현미 천립중은 큰 차이를 나타내지 않았다. 현미의 외관적 품질 중 완전립 비율은 기비 100% 시용구에서 가장 낮았고, 완전미 비율은 기비 70%, 50% 시용구에서 높았으며 현미 중 단백질 함량은 혼합유박 시용으로 적은 경향을 나타냈다. 결론적으로 평야지 보통논의 혼합유박 적정 시용량 및 시용시기는 기비 70%, 이앙 전 10~15일 시용으로 판단되었다.

이화학적 특성과 질소 안정동위원소비를 활용한 강우시 가축사육 밀집 지역의 하천 수질 영향 평가 (River Water Quality Impact Assessment in an Intensive Livestock Farming Area During Rainfall Event using Physicochemical characteristics and Nitrogen Stable Isotopes)

  • 류홍덕;백운일;김선정;김덕우;김찬식;김민섭;신동석;이재관;정유진
    • 한국환경과학회지
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    • 제28권1호
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    • pp.7-18
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    • 2019
  • This study aimed to assess the impact of livestock excreta discharged from an Intensive Livestock Farming Area (ILFA) on river water quality during a rainfall event. The Bangcho River, which is one of the 7 tributaries in the Cheongmi River watershed, was the study site. The Cheongmi River watershed is the second largest area for livestock excreta discharge in Korea. Our results clearly showed that, during the rainfall event, the water quality of the Bangcho River was severely deteriorated due to the COD, $NH_4-N$, T-N, $PO_4-P$, T-P, and heavy metals (Cu, Zn, and Mn) in the run-off from nearby farmlands, where the soil comprised composted manure and unmanaged livestock excreta. In addition, stable isotope analysis revealed that most of nitrogen ($NH_4-N$ and $NO_3-N$) in the run-off was from the ammonium and nitrate in the livestock excreta. The values of ${\delta}^{15}N_{NH4}$ and ${\delta}^{15}N_{NO3}$ for the Bangcho River water sample, which was obtained from the downstream of mixing zone for run-off water, were lower than those for the run-off water. This indicates that there were other nitrogen sources upstream river in the river. It was assumed from ${\delta}^{15}N_{NH4}$ and ${\delta}^{15}N_{NO3}$ stable isotope analyses that these other nitrogen sources were naturally occurring soil nitrogen, nitrogen from chemical fertilizers, sewage, and livestock excreta. Therefore, the use of physicochemical characteristics and nitrogen stable isotopes in the water quality impact assessment enabled more effective analysis of nitrogen pollution from an ILFA during rainfall events.

휴폭 및 이른 봄 질소시용이 이탈리안 라이그라스의 생육특성과 종자수량에 미치는 영향 (Effects of Drill Widths and Nitrogen Application Levels in Early Spring on the Growth Characteristics and Seed Productivity of Italian Ryegrass (Lolium multifloum Lam.))

  • 최기준;정의수;임용우;임영철;김기용;성병렬;박근제
    • 한국초지조사료학회지
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    • 제22권3호
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    • pp.221-226
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    • 2002
  • 이탈리안 라이그라스의 생육특성 및 종자 생산성을 조사하기 위하여 축산기술연구소 초지 사료과 시험포장에서 2000년부터 2001년까지 실시하였다. 시험구 배치는 휴폭(15, 30, 45cm) 및 이른 봄 질소시용량(50, 75, 100kg/㏊)을 조합한 분할 구배치 3반복으로 설계되었다. 생육특성 중에서 도복저항성은 휴폭이 45cm로 넓고 이른 봄 질소시용량이 50kg/㏊로 적을 때 높게 나타났고, 줄기의 수는 휴폭이 45cm 보다는 15 또는 30cm에서 많은 경향이었으며, 나머지 생육특성은 비슷하였다. 종자수량 구성요소에 있어서 단위면적당 이삭 수는 휴폭이 좁음에 따라서 많은 경향이었으나, 이삭의 길이와 1000립중은 휴폭이 넓음에 따라서 보다 길고 무거운 경향이었으며, 등숙율은 휴폭 30cm와 질소비료 50kg/㏊ 조합에서 가장 높았다. 또한 종자 수량은 휴폭 30cm와 이른 봄 질소시용량 50kg/㏊ 조합에서 가장 높은 수량을 나타내었다.

큰느타리버섯 배지 질소함량 및 온도조건별 선도연장효과 (The effect of nitrogen contents in media and cultivation temperature on freshness prolongation in Pleurotus eryngii)

  • 문지영;김정한;최종인;정구현;권희민;하태문
    • 한국버섯학회지
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    • 제18권4호
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    • pp.339-343
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    • 2020
  • 본 연구는 수출용 큰느타리버섯의 선도 유지 및 저장성 증대를 위한 배지 적합 질소함량과 생육온도 조건을 설정하고자 하였다. 배지 질소함량 1.5%, 1.8%, 2.1%, 2.4% 및 생육온도 15℃, 12℃, 9℃ 조건별로 자실체의 생육특성, 수확 후 냉장저장기간 동안의 가스농도, 자실체 품질변화를 조사하였다. 대 직경과 중량은 생육온도와 관계없이 질소함량이 높아질수록 증가하는 경향을 보였으며 병당 중량은 12℃, T-N 2.4% 조건에서 149.5 g으로 가장 높았다. 갓 색은 배지 질소함량과 관계없이 온도가 낮아질수록 색도(L)가 낮아져 갓 색이 진해졌다. 저장기간에 따른 봉지 내 가스농도 변화는 9℃, T-N 2.1% 조건에서 산도 농도가 가장 오래 유지되었다. 달관조사에 의한 자실체 품질평가에서 배지 질소함량에 따른 차이는 나타나지 않았고 저장기간 28일까지 이취, 변색, 부패 정도는 15℃와 9℃가 유사하게 나타났다.

크리핑 벤트그라스 훼어웨이에서 관수회수.예지물과 질소시비수준이 엽조직 및 토양 질소함유량에 미치는 효과 (A Three-year Study on the Leaf and Soil Nitrogen Contents Influenced by Irrigation Frequency, Clipping Return or Removal and Nitrogen Rate in a Creeping Bentgrass Fairway)

  • 김경남;로버트쉬어만
    • 아시안잔디학회지
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    • 제11권2호
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    • pp.105-115
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    • 1997
  • Responses of 'Penncross' creeping bentgrass turf to various fairway cultural practices are not well-established or supported by research results. This study was initiated to evaluate the effects of irrigation frequency, clipping return or removal, and nitrogen rate on leaf and soil nitrogen con-tent in the 'Penncross' creeping bentgrass (Agrostis palustris Huds.) turf. A 'Penncross' creeping bentgrass turf was established in 1988 on a Sharpsburg silty-clay loam (Typic Argiudoll). The experiment was conducted from 1989 to 1991 under nontraffic conditions. A split-split-plot experimental design was used. Daily or biweekly irrigation, clipping return or removal, and 5, 15, or 25 g N $m-^2$ $yr-^1$ were the main-, sub-, and sub-sub-plot treatments, respectively. Treatments were replicated 3 times in a randomized complete block design. The turf was mowed 4 times weekly at a l3 mm height of cut. Leaf tissue nitrogen content was analyzed twice in 1989 and three times in both 1990 and 1991. Leaf samples were collected from turfgrass plants in the treatment plots, dried immediately at 70˚C for 48 hours, and evaluated for total-N content, using the Kjeldahl method. Concurrently, six soil cores (18mm diam. by 200 mm depth) were collected, air dried, and analyzed for total-N content. Nitrogen analysis on the soil and leaf samples were made in the Soil and Plant Analyical Laboratory, at the University of Nebraska, Lincoln, USA. Data were analyzed as a split-split-plot with analysis of variance (ANOVA), using the General Linear Model procedures of the Statistical Analysis System. The nitrogen content of the leaf tissue is variable in creeping bentgrass fairway turf with clip-ping recycles, nitrogen application rate and time after establishment. Leaf tissue nitrogen content increased with clipping return and nitrogen rate. Plots treated with clipping return had 8% and 5% more nitrogen content in the leaf tissue in 1989 and 1990, respectively, as compared to plots treated with clipping removal. Plots applied with high-N level (25g N $m-^2$ $yr-^1$)had 10%, 17%, and 13% more nitrogen content in leaf tissue in 1989, 1990, and 1991, respectively, when compared with plots applied with low-N level (5g N $m-^2$ $yr-^1$). Overall observations during the study indicated that leaf tissue nitrogen content increased at any nitrogen rate with time after establishment. At the low-N level treatment (5g N $m-^2$ $yr-^1$ ), plots sampled in 1991 had 15% more leaf nitrogen content, as compared to plots sampled in 1989. Similar responses were also found from the high-N level treatment (25g N $m-^2$ $yr-^1$ ).Plots analyzed in 1991 were 18% higher than that of plots analyzed in 1989. No significant treatment effects were observed for soil nitrogen content over the first 3 years after establishment. Strategic management application is necessary for the golf course turf, depending on whether clippings return or not. Different approaches should be addressed to turf fertilization program from a standpoint of clipping recycles. It is recommended that regular analysis of the soil and leaf tissue of golf course turf must be made and fertilization program should be developed through the interpretation of its analytic data result. In golf courses where clippings are recycled, the fertilization program need to be adjusted, being 20% to 30% less nitrogen input over the clipping-removed areas. Key words: Agrostis palustris Huds., 'Penncross' creeping bentgrass fairway, Irrigation frequency, Clipping return, Nitrogen rate, Leaf nitrogen content, Soil nitrogen content.

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만경강 하천토양에서 노랑꽃창포의 생장특성과 질소·인 제거효과 (Growth Characteristics and Removal Effect of Nitrogen and Phosphoric Acid of Iris pseudoacorus at Waterway Soils of Mangyeong River)

  • 서병수;최수민;박우진;박종민
    • 한국환경복원기술학회지
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    • 제7권5호
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    • pp.57-65
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    • 2004
  • This study was carried out to measure the growth and photosynthesis of Iris pseudoacorus, the reduction rate of nitrogen(T-N) and phosphoric acid($P_2O_5$) from soils, and the increase rate of two substance into plants which cultivated at waterway soils of different concentration of two substance. The results are summarized as follows; 1. The contents of nitrogen and phosphoric acid at waterway soils of Mangyeong river showed the highest level in the around Samrye railway bridge where was located in the downstream and sewage of stock raising flowed in 2. The Iris pseudoacorus which cultivated at waterway soils showed the leaf and root growth of 43~50 and 9~13cm, respectively. And the growth was higher in the waterway soils contained high level of nitrogen The rate of photosynthesis was $3.5-5.9{\mu}mol\;m^{-2}s^{-1}$ ranges and this rate increased from the end of June to August and then decreased. The rate of photosynthesis was higher in waterway soils contained high nitrogen regardless of seasons. 4. The Iris pseudoacorus removed nitrogen and phosphoric acid from waterway soils about 19~21% and 13~15%, respectively. The Iris pseudoacorus was effective to remove nitrogen more than phosphoric acid. And the waterway soil which included high concentration of two substance showed highly removal 5. The results of Iris pseudoacorus vegetation in the waterway soils showed that nitrogen and phosphoric acid of inside plant increased with 0.2-1.0% and 0.01-0.10% ranges, respectively. The contents of nitrogen and phosphoric acid in plants were increase in the soils of higher contents of nitrogen and phosphoric acid, and the rate of increase of nitrogen and phosphoric acid was higher at roots than leaves.