• Nuclear Engineering and Technology
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• 제54권6호
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• pp.1962-1971
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• 2022

The liquid lead-lithium (Pb-17Li) blanket has many applications in fusion reactors due to its good tritium breeding performance, high heat transfer efficiency and safety. The compatibility of liquid Pb-17Li alloy with the structural material of blanket under magnetic field is one of the concerns. In this study, corrosion experiments China low activation martensitic (CLAM) steel and 316L steel were carried out in a forced convection Pb-17Li loop under 1.0 T magnetic field at 480 ℃ for 1000 h. The corrosion results on 316L steel showed the characteristic with a superficial porous layer resulted from selective leaching of high-soluble alloy elements and subsequent phase transformation from austenitic matrix to ferritic phase. Then the porous layers were eroded by high-velocity jet fluid. The main corrosion mechanism of CLAM steel was selective dissolution-base corrosion attack on the microstructure boundary regions and exclusively on high residual stress areas. CLAM steel performed a better corrosion resistance than that of 316L steel. The high Ni dissolution rate and the erosion of corroded layers are the main causes for the severe corrosion of 316L steel.

• Journal of Plant Biology
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• 제5권2호
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• pp.6-12
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• 1962

For the comparison with the previous paper (4) the present report deals with the absorption and metabolism of urea and other nitrogen ions in barley seedling absorbed through root. 1. The amount of nitrate in barley treated with urea reach it peak on the 8th day. NO3 on the 4th, NH4 on the 6th or 8th, respectively. 2. The ammonia content in urea group reaches its peak on the 6th day but other groups on the 4th day. The present data in the urea group show to shorten 4 days compared with that of the previous paper(4). 3. the content of total amide from the present data aare gradully increased on all of the groups during this experiment. These are agreement with the result of the previous paper (4). 4. the alcohol solution nitrogen in the urea gorup shows the similar tendency to the NaNO3 group but reaches it peak 2 days later than in the (NH4)2SO4 group. 5. The content of total nitrogen in the urea series has the lowest amount at the beginning while the richest from the 4th day after. These would be explained on that the absorption of urea is delayed and the PH in the urea solution does not change, so called "physiological neutrality". The author should like express his sincere thanks to Prof. M.J.Lee of Seoul National University for his valuable advices.e advices.

• Nuclear Engineering and Technology
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• 제52권9호
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• pp.1955-1962
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• 2020

In a sudden shutdown of primary pump or coolant loss accident in a marine nuclear power plant, the primary flow decreases rapidly in a transition process from forced circulation (FC) to natural circulation (NC), and the lower flow enters the steam generator (SG) causing reverse flow in the U-tube. This can significantly compromise the safety of nuclear power plants. Based on the marine natural circulation steam generator (NCSG), an experimental loop is constructed to study the characteristics of reverse flow under middle-temperature and middle-pressure conditions. The transition from FC to NC is simulated experimentally, and the characteristics of SG reverse flow are studied. On this basis, the experimental loop is numerically modeled using RELAP5/MOD3.3 code for system analysis, and the accuracy of the model is verified according to the experimental data. The influence of the flow variation rate on the reverse flow phenomenon and flow distribution is investigated. The experimental and numerical results show that in comparison with the case of adjusting the mass flow discontinuously, the number of reverse flow tubes increases significantly during the transition from FC to NC, and the reverse flow has a more severe impact on the operating characteristics of the SG. With the increase of flow variation rate, the reverse flow is less likely to occur. The mass flow in the reverse flow U-tubes increases at first and then decreases. When the system is approximately stable, the reverse flow is slightly lower than obverse flow in the same U-tube, while the flow in the obverse flow U-tube increases.

• 한국정보통신학회논문지
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• 제17권6호
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• pp.1306-1311
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• 2013

차량 운전자는 안전을 위해 항상 자신의 차량의 상태를 점검하고 파악하는 것이 필수이다. 운전자가 자동차의 상태를 알려고 하면 자동차 네트워크인 OBD-II와 연결되는 OBD-II 커넥터를 이용하여 자동차 실시간 제어 데이터를 이용해 자동차의 상태를 알 수 있다. 하지만 OBD-II의 데이터를 가져오는 커넥터는 스마트 디바이스(스마트폰, 블랙박스, EDR등)에 연결되는 통신 연결 방식이 각각 다르다. 차량 운전자가 스마트 디바이스를 다른 장치(안드로이드->아이폰, 아이폰->안드로이드 등)으로 바꾸게 되면 커넥터 또한 바뀌어서 새로 구매를 해야 하는 불편함이 존재 한다. 본 논문은 이러한 단점을 보완 하고자 각 장치에서 대부분 사용되어 지는 Bluetooth와 Wifi, WCDMA 모듈을 통합하여 사용자가 1개의 리더기 만으로도 어느 장치에서든지 OBD-II네트워크에서 자동차 실시간 제어 데이터를 알 수 있는 OBD-II 네트워크의 리더를 위한 통합 하드웨어를 구현 하였다.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 추계국제학술대회
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• pp.91-93
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• 2003

It has been estimated that the equivalent of approximately $US 50 billion has been spent on research on the behavior and fate of pesticides in the environment since Rachel Carson published “Silent Spring” in 1962. Much of the resulting knowledge has been summarized explicitly in computer algorithms in a variety of empirical, deterministic, and probabilistic simulation models. These models describe and predict the transport, degradation and resultant concentrations of pesticides in various compartments of the environment during and after application. In many cases the known errors of model predictions are large. For this reason they are typically designed to be “conservative”, i.e., err on the side of over-prediction of concentrations in order to err on the side of safety. These predictions are then compared with toxicity data, from tests of the pesticide on a series of standard representative biota, including terrestrial and aquatic indicator species and higher animals (e.g., wildlife and humans). The models' predictions are good enough in some cases to provide screening of those compounds which are very unlikely to do harm, and to indicate those compounds which must be investigated further. If further investigation is indicated a more detailed (and therefore more complicated) model may be employed to give a better estimate, or field experiments may be required. A model may be used to explore “what if” questions leading to possible alternative pesticide usage patterns which give lower potential environmental concentrations and allowable exposures. We are currently at a maturing stage in this research where the knowledge base of pesticide behavior in the environmental is growing more slowly than in the past. However, innovative uses are being made of the explosion in available computer technology to use models to take ever more advantage of the knowledge we have. In this presentation, current developments in the state of the art as practiced in North America and Europe will be presented. Specifically, we will look at the efforts of the ‘Focus’ consortium in the European Union, and the ‘EMWG’ consortium in North America. These groups have been innovative in developing a process and mechanisms for discussion amongst academic, agriculture, industry and regulatory scientists, for consensus adoption of research advances into risk management methodology.

• 정보관리학회지
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• 제5권1호
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• pp.53-78
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• 1988

The purpose of this study is to verify the factors determining core journals in a field based upon the results of the citation analysis of the journals in the field of Korean History(KH). In order to verify the determinant factors, dividing the articles of the KH journals into their novelty and author's seniority, the following hypotheses were established. Hypothesis 1: When a KH journal publishes more articles on prehistoric and ancient eras than others, the journal will have higher chance to be included in the core journals. Hypothesis 2: When a KH journal publishes more articles by senior researchers than others, the journal will have higher chance to be included in the core journals. To achieve the purpose, the cited articles found in the two sample journals, namely, Backsan Hakbo and Hanguksa Yongu were analysed during the past 20 years from 1962 to 1981. Applying the Hirst's Discipline Impact Factor method to the the study, Historical Science Impact Factor(HSIF) on the samples itself and the historical era dealt with in the articles and the seniority of the authors during every five-year period. Based upon thr present study to ver~fy the two hypotheses, the following conclusions have been reached. 1) Tht. most influencing sublect mattcr era or1 thix liSIF of the lo~lrual is arranged in prehistoric arid ancient, Koryo, Chosun, recent era, and the others by order of era. 2 ) Clial~g~~lg a fringe or semicore journal u~to a core j ~ u r n a l , very IISIF' 011 it> article e r a 1s grown up arrd prcllistoric a ~ ~ d ancierlt era:. are, s p c c ~ a l l ~ , incr.eased high relatively. Char~ging a core journal int:~ a fr~ngr or semicort. journal, t.very IISIF ti dropped and prel~istc~ric and ancieut taras arc, fallen sharp relatively. 3) The most irlflr~encin~ s~niority 011 the t1SII- of ihc journal I. the senior.., written or1 prehistoric and ancient eras. Above all, the senilir'b HSIF olr prehistoric anti anclent e r a s a r e most ~nfluencing the cliangi~rg of the core journal into the fringe ur bemicore. .i) flypothesis fl is no1 vcrif~ed i r t general. T l ~ e rt, lative connections bet wee^^ the senior's HSIF 011 each era and tht, ~ l ~ a l ~ g i t l g of the tort. ji1ur.tia1 arc \:er~fied in part hut r~ot in the wliole. 5) 'The reason why the 11SIF or1 prehistori~. arid ar~cic~nt e r a s is higl~er than others can be assumed becaltic the new <, xcavations a r r contit~ued actively i l l the prrsr.llt as to the relics arid remains or1 that eras. Accordingly, the HSIF' r i l l thr 11ew 3ubject matter l~ke arcl~acmlogy trends to grow up greatly. Bctween the senior's and juriior's JISIE', junior'.; is higl~er than s., nior's except ancient e r a . That reason can be assumed bccausr Iunlorb t r j to solve the ex~sting problems thr~urglr their ow11 new viewpoints and sights. So, i t should be studied whether the 11SlF on the artic1t.s of the new subject matters and viewpoirrts is influenced to the changing of the core jorlrnal or not.

• 한국식품과학회지
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• 제42권5호
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• pp.586-592
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• 2010

미국의 영양사협회(32)에서는 설탕에서 얻은 열량을 전체 섭취량의 10-15%까지로 유지할 것을 권장하고 있고, WHO(33)에서는 전체 섭취 열량의 10% 이하로 권장하고 있다. 서구사회에서 뿐만 아니라 우리나라에서도 설탕 섭취량은 꾸준히 증가하고 있는데, 성인 1인 1일 당류 공급량은 1962년 4.8 g에서 1987년 41.9 g, 2003년 57.4 g으로 나타났으며(34), 2007년 한국인의 1일 평균 설탕 섭취량은 100 g, 총 섭취량의 20%로 권장량의 두 배 이상으로 점차 증가되고 있다(35). 그러나 본 실험에서 사용된 스테비아의 당도는 설탕의 200배 이상이나 칼로리는 설탕의 90분의 1에 불과하여 설탕의 대체제로서 가능성이 충분할 것으로 보여진다. 이에 본 연구는 스테비아 잎 추출물 보강이 고지방식이로 비만이 유도된 C57BL/6J mice에서 항비만 효과를 알아보고자 하였다. 실험동물은 정상 대조군(NC), 고지방 대조군(HC), 고지방식이+스테비아 잎 추출물 투여군(HLSV, 1 mL/kg/day), 고지방식이+스테비오사이드 투여군(HSS, 1 mL/kg/day) 4군으로 나누어 사육하였으며, 연구결과는 다음과 같다. 체중증가량은 스테비아 잎 추출물 투여군(HLSV)에서 고지방 대조군(HC)과 비교 시 유의적으로 감소하였으나, 스테비오사이드 투여군(HSS)은 고지방 대조군(HC)비교 시 감소하는 경향을 보였고 유의적 차이는 없었다. 부고환지방은 스테비아 잎 추출물 투여군(HLSV)과 스테비오사이드 투여군(HSS)에서 고지방 대조군(HC) 보다 유의적으로 감소하였고, 등지방은 스테비아 잎 추출물 투여군(HLSV)에서 유의적으로 감소하였다. 혈중 및 간중 중성지방은 스테비아 잎 추출물 투여군(HLSV)이 고지방 대조군(HC)보다 유의적으로 감소하였으며, 스테비오사이드 투여군(HSS)은 고지방 대조군(HC)에 비해 혈중 중성지방이 유의적으로 감소하였다. 혈중 카르니틴 중 NEC의 농도는 고지방 대조군(HC) 보다 스테비아 잎 추출물 투여군(HLSV)과 스테비오사이드 투여군(HSS)에서 유의적으로 증가하였으며 혈중 ASAC와 간중 acyl/free carnitine은 고지방 대조군(HC)과 비교 시 스테비아 잎 추출물 투여군(HLSV)과 스테비오사이드 투여군(HSS)에서 증가하는 경향을 보였다. 지질대사와 관련한 체내 mRAN 발현정도를 측정한 결과 ACS mRNA 발현 수준은 고지방대조군(HC)과 비교 시 스테비아 추출물 투여군(HLSV)와 스테비오사이드 투여군(HSS)에서 증가하는 경향을 보였으며 특히, 스테비오사이드 투여군(HSS)에서 유의적으로 증가하였다. PPAR${\alpha}$ mRNA발현 수준은 고지방대조군(HC)과 비교 시 스테비아 추출물 투여군(HLSV)와 스테비오사이드 투여군(HSS)에서 유의적으로 증가하였으며, CPT-I mRNA 발현 수준은 고지방대조군(HC)과 비교 시 스테비아 추출물 투여군(HLSV)이 유의적으로 증가하였다. ACC mRNA 발현 수준은 정상대조군(NC)과 비교 시 고지방대조군(HC)에서 유의적으로 증가하였고, 스테비아 추출물 투여군(HLSV)은 고지방 대조군(HC)과 비교 시 유의적으로 감소하였으나 스테비오사이드 투여군(HSS)은 차이가 없었다. 결과적으로 스테비아 잎 추출물은 스테비오사이드에 비하여 체내 지질대사개선에 더 효과적인 것으로 보였으며 이는 스테비아의 다양한 phytochemical에 의한 것으로 보여진다. 따라서 이러한 결과는 스테비아가 비만을 치료하거나 예방하는데 효과적으로 활용될 수 있는 가능성을 보여주었다.

• 천문학회지
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• 제28권1호
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• pp.31-43
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• 1995

We present UBVRI CCD photometry of the Type Ie supernova SN 19941 in M51 which was discovered on April 2, 1994 (UT). UBVRI CCD photometry of SN 1994 I were obtained for the period of the first two months from April 4, 1994, using the Seoul National University Observatory 60 cm telescope. The light curves of SN 19941 show several interesting features: (a) SN 19941 reaches the maximum brightness at B-band on April 8.23 (B = 13.68 mag), at V-band on April 9.10 (V = 12.89 mag), and at I-band on April 10.32 (I = 12.48 mag); (b) The light curves around the maximum brightness are much narrower than those of other types of supernovae; (c) The light curves after the peak decline more steeply than those of other types of supernovae; and (d) The colors get redder from $(V-R){\approx}0.2 mag ((V - I){\approx} 0.3 mag, (B - V){\approx}0.7 mag)$ on April 4 to $(V-R){\approx}0.6 mag ((V-1){\approx}0.9 mag, (B-V){\approx}1.3 mag)$ on April 18. Afterwards (V - R) colors get bluer slightly $(by\~0.005 mag/day)$, while (V-I) colors stay almost constant around $(V-1){\approx}1.0 mag$. The color at the maximum brightness is (B-V)=0.9 mag, which is $\~1$mag redder than the mean color of typical Type la supernovae at the maximum brightness. The light curves of SN 1994I are similar to those of the Type Ie supernova SN 1962L in NGC 1073. Adopting the distance modulus of $(m-M)_0 = 29.2 mag$ and the reddening of E(B - V) = 0.45 mag [Iwamoto et al. 1994, preprint for ApJ], we derive absolute magnitudes at the maximum brightness of SN 1994I, Mv(max) = -17.7 mag and MB(max) = -17.4 mag. This result shows that SN 1994I was $\~2$mag fainter at the maximum brightness compared with typical Type Ia supernovae. A narrower peak and faster decline after the maximum in the light curve of SN 1994I compared with other types of supernovae indicate that the progenitor of SN 1994I might be a lower mass star compared with those of other types of supernovae.

• 한국산림과학회지
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• 제4권1호
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• pp.9-13
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• 1965

Powdery mildew of Ailanthus altissima Sw. was first reported by J.S. Park in Korea, 1961. According to his report, this disease was found on the leaves of this tree species collected in Jeongup, 1957, and in Taejon, 1958. He described morphological characters of this pathogen and described also that the causal fungus may be closely related with Phyllactinia corylea. This disease which appears dusty grayish yellow molds under surface of leaves was collected again by the author in Kwangju, 1962. The present works were undertaken to make clear the species of causal fungus by means of the morphology and pathogenecity. According to the following results, the pathogen was identified as Phyllactinia corylea (Pers.) Karst. Morphological characters of the fungus Mycelia persistent or more or less evanescent; matured conidia solitary, aseptate, short-clavate to clavate to clavate, hyaline or yellowish, granulate, $44.6-89.2{\times}9.3-24.2{\mu}$, average $64.8-17.8{\mu}$ in size; conidiophores elongate clavate or columnar, hyaline, 2-3 septate, $122.8-346.0{\times}3.7-7.4{\mu}$, average $208.8{\times}6.3{\mu}$; per-thecia usually scattered, rarely gregarious, dark brown to black, depressed globose to globose, $223.2-297.6{\mu}$, average $267.8{\mu}$ in diameter; appendages 12-19, usually 15 in number, hyaline, straight, needle-shaped, sharply pointed at the apex and bulbous at the base, aseptate, $93.0-310.0{\times}5.0-8.0{\mu}$, average $173.3{\times}6.4{\mu}$ in size; asci elongate ellipsoidal to broadly clavate, hyaline, more or less stalked, 8-13 in number, $68.5-76.6{\times}26.1-34.2{\mu}$, average $71.4{\times}29.0{\mu}$ in size; ascospores 2-4, usually 2 in number, hyaline or yellowish, aseptate, ellipsoidal or ovate, $27.7-34.2{\times}14.7-17.9{\mu}$, average $25.5{\times}13.9{\mu}$ in size. Pathogenicity of the fungi In order to make clear the species of the fungus and the pathogenic differences of Phyllactinia fungi which are collected around the contaminated area and seemed to be related to Ailanthus powdery mildew, some inoculation experiments were performed. 1. Cross inoculation to several tree species with their pathogen: Tested materials; Phyllactinia in question on Ailanthus altissima Sw. Ph. fraxini (DC.) Homma. On Alnus firma S. et Z. Ph. moricola (P. Henn.) Homma on morus alba L. According to the results of the experiments, the reactions were all negative with the exception of the original hosts of tested fungi. 2. Inoculation to Picrasma ailanthoides Planch. : The appearance of symptom on the leaves of P. ailanthoides is not distinct, but more or less mycelial growth. Therefore, under the optimal condition in glass chamber, it may be possible to success artificially.

• 한국토양비료학회지
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• 제1권1호
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• pp.13-26
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• 1968

수도(水稻)에 대(對)한 인산(燐酸) 및 질소질(窒素質) 비료(肥料)의 효용에 관(關)하여 $N^{15}$ 및 $P^{32}$ 동위원소(同位元素)를 이용(利用)한 일련(一聯)의 국제적(國際的) 공동연구(共同硏究)가 IAEA 주관하(主管下)에 FAO의 지원(支援)으로 1962년(年)부터 6개년간(個年間)에 실시(實施)되었는데 본대학(本大學)은 1963년(年) 이래(以來) 이 공동연구(共同硏究)에 참가(參加)하였으며, 그 시험결과(試驗結果)를 요약(要約)하면 다음과 같다. 1. 과석(過石)은 전량(全量)을 이앙시(移秧時) 기비(基肥)로써 표면살시(表面撒市) 하거나 표층시용(表層施用)하는 것이 비효가 가장 컸다. 2. 과석(過石)을 분시(分施)한거나 생육(生育) 후기(後期)에 시용(施用)하면 수량(收量)에는 별(別)로 영향(影響)하지 않았으나 그것의 흡수율(吸收率)은 다소(多少) 저하(低下)되었다. 3. 우리나라 시험지(試驗地)의 유효인산함량은 대체(大體)로 60ppm 이상(以上)으로서 인산질(燐酸質) 비료(肥料)의 흡수율(吸收率)은 10% 내외(內外)이었으며 인산시용량(燐酸施用量)의 증가(增加)에 따른 흡수이용율(吸收利用率) 및 수량(收量)의 변화(變化)는 타국(他國)에 비(比)해 작았다. 4. 질소질(窒素質) 비료(肥料)는 생육성기(生育盛期)에 시용(施用)하는 경우 흡수율(吸收率)이 높으나 수량(收量)의 증가(增加)를 위(爲)하여서는 기비(基肥)로서의 시용(施用)이 유리(有利)하였다. 5. 질소질(窒素質) 비료(肥料)는 지중(地中) 5cm 깊이에 조시(條施)하는 경우 흡수율(吸收率) 및 수량(收量)이 가장 높았고 분시(分施)의 효과는 뚜렷하지 않았으며 이는 시용량(施用量)이 60kgN/ha로써 다소(多少) 적었기 때문으로 생각된다. 6. 우리나라 시험지(試驗地)에서의 질소흡수율(窒素吸收率)은 대체(大體)로 40% 내외(內外)이었고 질소반응(窒素反應)은 타국(他國)에 비(比)해 현저(顯著)한편이였으며 질소질(窒素質) 비료(肥料)의 시용방법(施用方法)의 차이(差異)에 따른 흡수율(吸收率) 및 수량(收量)의 차이(差異)도 현저(顯著)하였다. 7. 질소질(窒素質) 비료(肥料)의 흡수율(吸收率)은 인산(燐酸)의 시용방법(施用方法)에 영향(影響)을 받지 않았으나 인산(燐酸)의 흡수율(吸收率)은 질소(窒素)의 시용방법(施用方法)에 따라서는 다소간(多少間) 차이(差異)가 있었다. 8. 질소질(窒素質) 비료중(肥料中) 류안(硫安)과 요소(尿素)의 비효는 동등(同等)하였으며, nitrate 태(態) 비료(肥料)는 ammonia 태(態) 비료(肥料)보다 비효가 현저(顯著)히 낮았다. 9. 질소인산(窒素燐酸) 화성비료(化成肥料) 중(中) Ammo-Phos B는 류안(硫安)보다 비효가 다소(多少) 컸으며 이앙시(移秧時)에 기비(基肥)로 시용(施用)하는것이 효과적이었고 Nitric phosphate은 비효가 현저(顯著)히 낮았다.