• Title/Summary/Keyword: Heat-Treatment-Free

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Study on the feasibility of metallic saggar for synthesizing NCM cathode active materials-I (NCM 계 양극활물질 합성용 금속질 내화갑 가능성 연구-I)

  • Yong Il Park;Ji Hun Jung;Sung Hyun Woo;Jung Heon Lee;Hyeong-Jun Kim
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.34 no.3
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    • pp.103-107
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    • 2024
  • In this study, nickel, a pure metal material, was proposed as a saggar for synthesizing NCM [Li(NixCoyMnz)O2] cathode active material. Nickel is known as a metal that is resistant to oxidation and has a high melting point. Nickel is one of the main components of NCM cathode material and was expected to be free from problems with contamination from saggar during cathode material synthesis. We sought to confirm the possibility of nickel as a saggar for synthesizing NCM cathode active materials. When a Ni metal crucible and Ni0.8Co0.1Mn0.1(OH)2 (NCM 811) precursor material were reacted at 900℃ for a long time, the change in the reaction layer on the surface of the crucible over time was analyzed. The nickel crucible reaction layer formed during heat treatment at 900℃ was nickel oxide, and is thought to have been created by simultaneous oxygen diffusion from the cathode precursor oxide and reaction with oxygen in the atmosphere. The change in thickness of the oxide layer appears to slow down after 480 hours, which suggests that the rate of oxygen diffusion from the precursor is reduced. It remained combined without falling out of the crucible until 480 hours. However, it was confirmed that the oxide layer falls off after 720 hours, so it is thought that it can be used as saggar for NCM synthesis only for a certain period of time.

Effect of ${\alpha}-Amylase$ Treatment of Brown Rice(Goami) Alcohol Fermentation By-Product (현미(고아미) 알코올발효 부산물의 ${\alpha}-amylase$처리 효과)

  • Woo, Seung-Mi;Kim, Tae-Young;Yeo, Soo-Hwan;Kim, Sang-Burm;Kim, Mi-Hyun;Woo, Sang-Chel;Jeong, Yong-Jin
    • Food Science and Preservation
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    • v.14 no.6
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    • pp.617-623
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    • 2007
  • To utilize the non-heat treated alcoholic by-products of brown rice(Goami) as food sources, the quality characteristics change according to the treatment conditions of ${\alpha}-amylase$ were evaluated. It resulted that the increase of hydrolysis temperature correspondingly increased the soluble solids, total dietary fiber and total sugar in the by-products of Goami, and the highest reducing sugar content was observed at $80^{\circ}C$. The free amino acids contents were tended to slowly decrease by the hydrolysis temperature more than $70^{\circ}C$, and the highest content of oligosaccharides were detected at the hydrolysis temperature of $80^{\circ}C$. The soluble solid according to the ${\alpha}-amylase$ concentration resulted to increase with the increase of the enzyme concentration and the total dietary fiber revealed similarly showing approximately 0.65%. The high content of reducing sugars was observed at the enzyme concentration around 0.08%(v/w). Total sugars and oligosaccharides contents tend to increase as the concentration of enzyme increased, and the content of oligosaccharides acquired at the enzyme concentration more than 0.10%(v/w) maintained to show rather similar contents. The soluble solids and total dietary fiber by hydrolysis time were found to show 6.66% and 0.65%, respectively at more than 60 min of hydrolysis, and the reducing sugars and total sugars were found to be 3,600 and 4,800 mg% in all treatment groups showing no significant difference. The content of oligosaccharides was increased with the increase of hydrolysis time, and the content was similar at more than 90 min of hydrolysis by ranging around 2,100 mg%. Based upon these results, the by-products of Goami are expected to be used as various food sources showing the highest dietary fiber and oligosaccharides contents by the hydrolysis at $80^{\circ}C$ for 90 min with the addition of 0.10%(v/w) of ${\alpha}-amylase$.

Effects of Salt Treatment on Yield and Physiological Characteristics of Flag Leaf at Heading Stage in Winter Barley (보리 출수기 염처리가 수량 및 지잎의 생리적 특성에 미치는 영향)

  • 최원열;김영민;박종환
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.47 no.6
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    • pp.409-412
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    • 2002
  • This research was conducted to obtain the fundamental data on salt injury and different responses among cultivars in winter barley (Hordeum vulgare L.). Salts did not affect yield components including number of panicles, stem length, grain number per ear and grain yield while reduced stem dry weight and thousand seed weight significantly with increasing concentrations of salt from 60 to 180 mM. NaCl had less injury effect on barley straw dry weight and thousand seed weight than did $MgSO_4$. Chlorophyll content and relative turgidity in flag leaf were reduced when treated with both salts, while free proline in the salt-treated leaf was increased. Content of proline in salt-treated barley was about 10 folds compared to the control. Based on yield components and physiological traits of flag leaf, the tolerance to salt injury was the greatest in Baegdong, followed by Dongbori#1, Mogpo#55, and Gangbori. The results suggested that salt- stressed barley at reproductive stage had higher free proline content, and that special management in this stage must be considered because salt stress at heading stage affect flag leaf growth as well as yield components Harmfully.

COATED PARTICLE FUEL FOR HIGH TEMPERATURE GAS COOLED REACTORS

  • Verfondern, Karl;Nabielek, Heinz;Kendall, James M.
    • Nuclear Engineering and Technology
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    • v.39 no.5
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    • pp.603-616
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    • 2007
  • Roy Huddle, having invented the coated particle in Harwell 1957, stated in the early 1970s that we know now everything about particles and coatings and should be going over to deal with other problems. This was on the occasion of the Dragon fuel performance information meeting London 1973: How wrong a genius be! It took until 1978 that really good particles were made in Germany, then during the Japanese HTTR production in the 1990s and finally the Chinese 2000-2001 campaign for HTR-10. Here, we present a review of history and present status. Today, good fuel is measured by different standards from the seventies: where $9*10^{-4}$ initial free heavy metal fraction was typical for early AVR carbide fuel and $3*10^{-4}$ initial free heavy metal fraction was acceptable for oxide fuel in THTR, we insist on values more than an order of magnitude below this value today. Half a percent of particle failure at the end-of-irradiation, another ancient standard, is not even acceptable today, even for the most severe accidents. While legislation and licensing has not changed, one of the reasons we insist on these improvements is the preference for passive systems rather than active controls of earlier times. After renewed HTGR interest, we are reporting about the start of new or reactivated coated particle work in several parts of the world, considering the aspects of designs/ traditional and new materials, manufacturing technologies/ quality control quality assurance, irradiation and accident performance, modeling and performance predictions, and fuel cycle aspects and spent fuel treatment. In very general terms, the coated particle should be strong, reliable, retentive, and affordable. These properties have to be quantified and will be eventually optimized for a specific application system. Results obtained so far indicate that the same particle can be used for steam cycle applications with $700-750^{\circ}C$ helium coolant gas exit, for gas turbine applications at $850-900^{\circ}C$ and for process heat/hydrogen generation applications with $950^{\circ}C$ outlet temperatures. There is a clear set of standards for modem high quality fuel in terms of low levels of heavy metal contamination, manufacture-induced particle defects during fuel body and fuel element making, irradiation/accident induced particle failures and limits on fission product release from intact particles. While gas-cooled reactor design is still open-ended with blocks for the prismatic and spherical fuel elements for the pebble-bed design, there is near worldwide agreement on high quality fuel: a $500{\mu}m$ diameter $UO_2$ kernel of 10% enrichment is surrounded by a $100{\mu}m$ thick sacrificial buffer layer to be followed by a dense inner pyrocarbon layer, a high quality silicon carbide layer of $35{\mu}m$ thickness and theoretical density and another outer pyrocarbon layer. Good performance has been demonstrated both under operational and under accident conditions, i.e. to 10% FIMA and maximum $1600^{\circ}C$ afterwards. And it is the wide-ranging demonstration experience that makes this particle superior. Recommendations are made for further work: 1. Generation of data for presently manufactured materials, e.g. SiC strength and strength distribution, PyC creep and shrinkage and many more material data sets. 2. Renewed start of irradiation and accident testing of modem coated particle fuel. 3. Analysis of existing and newly created data with a view to demonstrate satisfactory performance at burnups beyond 10% FIMA and complete fission product retention even in accidents that go beyond $1600^{\circ}C$ for a short period of time. This work should proceed at both national and international level.

Physicochemical and sensory properties of Yakhobak (Cucurbita maxima subsp. maxima) paste under different high pressure heating conditions (가열조건에 따른 약호박(Cucurbita maxima subsp. maxima) 페이스트의 이화학적 관능적 품질특성)

  • Park, Bo-Ram;Choi, Su-Jeong;Kim, Na-Jeong;Han, Gui-Jung;Kim, Ha-Yun
    • Food Science and Preservation
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    • v.24 no.1
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    • pp.44-51
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    • 2017
  • For the production of Yakhobak (Cucurbita maxima subsp. maxima) paste under various heating conditions, we steamed Yakhobak for roughly 20 min, followed by heating under high pressure treatment for 0 min (HHP0), 20 min (HHP20), 40 min (HHP40), and 60 min (HHP60). The physicochemical and sensory characteristics were subsequently investigated. Generally, no significant difference was observed in organic acid content and sensory characteristics score between Yakhobak paste treated with and without high-pressure heating. However, there was a significant difference in color value, soluble solids, and free sugar content. The L value for color of the group HHP0, untreated control Yakhobak paste (no high-pressure heating), decreased as time increased from 20 min to 60 min, with L values of 44.33, 44.25, and 42.86, respectively. The b value for the color of Yakhobak paste also decreased, showing a significant difference. Soluble solids and free sugar (fructose, glucose, sucrose) contents of the high-pressure heat-treated groups HHP20, HHP40, and HHP60 decreased compared with untreated group HHP0. Organic acid composition of Yakhobak paste included citric acid, malic acid, and fumaric acid, and the major organic acid was malic acid. Sensory score of HHP40 was the highest among all experimental groups in terms of overall preference, but there was no significant difference.

Effect of titanium powder on the bond strength of metal heat treatment (티타늄 파우더가 금속의 열처리 시 결합강도에 미치는 영향)

  • Kim, Sa-Hak;Kim, Wook-Tae
    • Journal of Dental Rehabilitation and Applied Science
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    • v.33 no.2
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    • pp.71-79
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    • 2017
  • Purpose: Ni-Cr alloy does not contain Beryllium, causing the metal compound to form oxides in the furnace but by using Titanium as a chemical catalyst the forming of the oxides can be controlled, and by controlling the impurities formed on the metal surface, the possibility of the Ni-Cr alloy bond strength being increased can be analysed. Materials and Methods: Titanium was used as a chemical catalyst in the porcelain for the oxidation of beryllium-free metal (Ni-Cr) alloy. The T1 group, which does not use Titanium power as a chemical catalyst is a reference model for comparison. The T2 group and T3 group used 10 g and 20 g of Titanium power, respectively. They are fabricated to observe the shear bond strength and surface properties. There was no significance when One-way ANOVA analysis/Tukey Honestly Significant Difference Test was conducted for statistical analysis among groups (P > 0.05). Results: Results of measuring the three-point flexural bond strength of the Ni-Cr alloy and thickness of the oxide film. Experiment T3 using 20 g Titanium chemical catalyst: $39.22{\pm}3.41MPa$ and $6.66{\mu}m$, having the highest bond strength and thinness of oxide film. Experiment T2 using 10 g Titanium chemical catalyst: $34.65{\pm}1.39MPa$ and $13.22{\mu}m$. Experiment T1 using no Titanium chemical catalyst: $32.37{\pm}1.91MPa$ and $22.22{\mu}m$. Conclusion: The T2 and T3 experiments using Titanium chemical catalyst showed higher bond strength for the Ni-Cr alloy and lower thickness of oxide film than experiment T1, and the titanium catalyst being able to increase bond strength was observed.

Quality Changes in Red Ginseng Extract during High Temperature Storage (열처리(熱處理)에 의한 홍삼(紅蔘)엑기스의 성분변화(成分變化))

  • Choi, Jin-Ho;Kim, Woo-Jung;Yang, Jae-Won;Sung, Hyun-Soon;Hong, Soon-Keun
    • Applied Biological Chemistry
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    • v.24 no.1
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    • pp.50-58
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    • 1981
  • The influence of high temperature storage on the chemical composition and color intensity of the concentrated red ginseng extract(RGE) was investigated. The concentrated RGE was prepared by extraction of red ginseng tails with water and concentrated under reduced pressure. Changes in free sugars, saponin patterns and brown color intensity were measured during 96 hours of heat treatment at various temperature. A decrease in the contents of glucose, fructose and sucrose was resulted as the brown color intensity increased during the storage. The sugar contents and color intensity showed rapid initial change followed by slowing down at higher temperature. A significant relationship was found between sugar content and browning rate. The saponin pattern measured by high performance liquid chromatography, particularly in the region of protopanaxtriol, was also affected significantly. The peak heights of ginsenoside -Re and $-Rg_1$ were decreased while those of ginsenoside $-Rg_2$ and -Rh group were increased.

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Convenient Nucleic Acid Detection for Tomato spotted wilt virus: Virion Captured/RT-PCR (VC/RT-PCR) (Tomato spotted wilt virus를 위한 간편한 식물바이러스 핵산진단법: Virion Captured/RT-PCR (VC/RT-PCR))

  • Cho Jeom-Deog;Kim Jeong-Soo;Kim Hyun-Ran;Chung Bong-Nam;Ryu Ki-Hyun
    • Research in Plant Disease
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    • v.12 no.2
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    • pp.139-143
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    • 2006
  • Virion captured reverse transcription polymerase chain reaction (VC/RT-PCR) could detect plant virus quickly and accurately. In the VC/RT-PCR, no antibody is needed unlike immuno-captured RT-PCR (IC/RT-PCR) which had been improved method of RT-PCR for plant viruses, and virus nucleic acids can be obtained easily within 30minutes by property of polypropylene PCR tube which is hold and immobilized viral particles on its surface. For the virion capture of Tomato spotted wilt virus (TSWV), the extraction buffer was tested. The optimum macerating buffer for TSWV was 0.01M potassium phosphate buffer, pH 7.0, containing 0.5% sodium sulfite. The viral crude sap was incubated for 30 min at $4^{\circ}C$. The virions in the PCR tubes were washed two times with 0.01M PBS containing 0.05% Tween-20. The washed virions were treated at $95^{\circ}C$ immediately for 1 min containing RNase free water and chilled quickly in the ice. Disclosed virions' RNAs by heat treatment were used for RT-PCR. Dilution end point of $10^{-5}$ from plant's crude sap infected with TSWV showed relatively higher detection sensitivity for VC/RT-PCR. During multiple detection using two or more primers, interference was arisen by interactions between primer-primer and plant species. The result of multiplex RT-PCR was influenced by combinations of primers and the kind of plant, and the optimum extraction buffer for the multiplex detection by VC/RT-PCR should be developed.

Studies on Sclerotium rolfsii Sacc. isolated from Magnolia kobus DC. in Korea (목련(Magnolia kobus DC.)에서 분리한 흰비단병균(Sclerotium rolfsii Sacc.)에 관한 연구)

  • Kim Kichung
    • Korean journal of applied entomology
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    • v.13 no.3 s.20
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    • pp.105-133
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    • 1974
  • The present study is an attempt to solve the basic problems involved in the control of the Sclerotium disease. The biologic stranis of Sclerotium rolfsii Sacc., pathogen of Sclerotium disease of Magnolia kobus, were differentiated, and the effects of vitamins, various nitrogen and carbon sources on its mycelial growth and sclerotial production have been investigated. In addition the relationship between the cultural filtrate of Penicillium sp. and the growth of Sclerotium rolfsii, the tolerance of its mycelia or sclerotia to moist heat or drought and to Benlate (methyl-(butylcarbamoy 1)-2-benzimidazole carbamate), Tachigaren (3-hydroxy-5-methylisoxazole) and other chemicals were also clarified. The results are summarizee as follows: 1. There were two biologic strains, Type-l and Type-2 among isolates. They differed from each other in the mode of growth and colonial appearance on the media, aversion phenomenon and in their pathogenicity. These two types had similar pathogenicity to the Magnolia kobus and Robinia pseudoacasia, but behaved somewhat differently to the soybaen and cucumber, the Type-l being more virulent. 2. Except potassium nitrite, sodium nitrite and glycine, all of the 12 nitrogen sources tested were utilized for the mycelial growth and sclerotial production of this fungus when 10r/l of thiamine hydrochloride was added in the culture solution. Considering the forms of nitrogen, ammonium nitrogen was more available than nitrate nitrogen for the growth of mycelia, but nitrate nitrogen was better for sclerotia formation. Organic nitrogen showed different availabilities according to compounds used. While nitrite nitrogen was unavailable for both mycelial growth and sclerotial formation whether thiamine hydrochlioride was added or not. 3. Seven kinds of carbon sources examined were not effective in general, as long as thiamine hydrochloride was not added. When thiamine hydrochloride was added, glucose and saccharose exhibited mycelial growth, while rnaltose and soluble starch gave lesser, and xylose, lactose, and glycine showed no effect at all,. In the sclerotial production, all the tested carbon sources, except lactose, were effective, and glucose, maltose, saccharose, and soluble starch gave better results. 4. At the same level of nitrogen, the amount of mycelial growth increased as more carbon Sources were applied but decreased with the increase of nitrogen above 0.5g/1. The amount of sclerotial production decreased wi th the increase of carbon sources. 5. Sclerotium rolfsii was thiamine-defficient and required thiamine 20r/l for maximun growth of mycelia. At a higher concentration of more than 20r/l, however, mycelial growth decreased as the concentration increased, and was inhibited at l50r/l to such a degree of thiamine-free. 6. The effect of the nitrogen sources on the mycelial growth under the presence of thiamine were recognized in the decreasing order of $NH_4NO_3,\;(NH_4)_2SO_4,\;asparagine,\;KNO_3$, and their effects on the sclerotial production in the order of $KNO_3,\;NH_4NO_3,\;asparagine,\;(NH_4)_2SO_4$. The optimum concentration of thiamine was about 12r/l in $KNO_3$ and about 16r/l in asparagine for the growth of mycelia; about 8r/l in $KNO_3$ and $NH_4NO_3$, and 16r/l in asparagine for the production of sclerotia. 7. After the fungus started to grow, the pH value of cultural filtrate rapidly dropped to about 3.5. Hereafter, its rate slowed down as the growth amount increased and did not depreciated below pH2.2. 8. The role of thiamine in the growth of the organism was vital. If thiamine was not added, the combination of biotin, pyridoxine, and inositol did not show any effects on the growth of the organism at all. Equivalent or better mycelial growth was recognized in the combination of thiamine+pyridoxine, thiamine+inositol, thiamine+biotin+pyridoxine, and thiamine+biotin+pyridoxine+inositol, as compared with thiamine alone. In the combinations of thiamine+biotin and thiamine+biotin+inositol, mycelial growth was inhibited. Sclerotial production in dry weight increased more in these combinations than in the medium of thiamine alone. 9. The stimulating effects of the Penicillium cultural filtrate on the mycelial growth was noticed. It increased linearly with the increase of filtrate concentration up to 6-15 ml/50ml basal medium solution. 10. $NH_4NO_3$. as a nitrogen source for mycelial growth was more effective than asparasine regardless of the concentration of cultural filtrate. 11. In the series of fractionations of the cultural filtrate, mycelial growth occured in unvolatile, ether insoluble cation-adsorbed or anion-unadsorbed substance fractions among the fractions of volatile, unvolatile acids, ether soluble organic acids, ether insoluble, cation-adsorbed, cation-unadsorbed, anion-adsorbed and anion-unadsorbed. and anion-un-adsorbed substance tested. Sclerotia were produced only in cation-adsorbed fraction. 12. According to the above results, it was assumed that substances for the mycelial growth and sclerotial formation and inhibitor of sclerotial formation were include::! in cultural filtrate and they were quite different from each other. I was further assumed that the former two substances are un volatile, ether insotuble, and adsorbed to cation-exchange resin, but not adsorbed to anion, whereas the latter is unvolatile, ether insoluble, and not adsorbed to cation or anion-exchange resin. 13. Seven amino acids-aspartic acid, cystine, glysine, histidine, Iycine, tyrosine and dinitroaniline-were detected in the fractions adsorbed to cation-exchange resin by applying the paper chromatography improved with DNP-amino acids. 14. Mycelial growth or sclerotial production was not stimulated significantly by separate or combined application of glutamic acid, aspartic acid, cystine, histidine, and glysine. Tyrosine gave the stimulating effect when applied .alone and when combined with other amino acids in some cases. 15. The tolerance of sclerotia to moist heat varied according to their water content, that was, the dried sclerotia are more tolerant than wet ones. The sclerotia harvested directly from the media, both Type-1 and Type-2, lost viability within 5 minutes at $52^{\circ}C$. Sclerotia dried for 155 days at$26^{\circ}C$ had more tolerance: sclerotia of Type-l were killed in 15 mins. at $52^{\circ}C$ and in 5 mins. at $57^{\circ}C$, and sclerotia of Type-2 were killed in 10 mins. both at $52^{\circ}C$ or $57^{\circ}C$. 16. Cultural sclerotia of both strains maintained good germinability for 132 days at$26^{\circ}C$. Natural sclerotia of them stored for 283 days under air dry condition still had good germinability, even for 443 days: type-l and type-2 maintained $20\%$ and $26.9\%$ germinability, respectively. 17. The tolerance to low temperature increased in the order of mycelia, felts and sclerotia. Mycelia completely lost the ability to grow within 1 week at $7-8^{\circ}C$> below zero, while mycelial felts still maintained the viability after .3 weeks at $7-20^{\circ}C$ below zero, and sclerotia were even more tolerant. 18. Sclerotia of type-l and type-2 were killed when dipped into the $0.05\%$ solution of mercury chloride for 180 mins. and 240 mins. respectively: and in the $0.1\%$ solution, Type-l for 60 mins. and Type-2 for 30 mins. In the $0.125\%$ uspulun solution, Type-l sclerotia were killed in 180 mins., and those of Type-2 were killed for 90 mins. in the$0.125\%$solution. Dipping into the $5\%$ copper sulphate solution or $0.2\%$ solution of Ceresan lime or Mercron for 240 mins. failed to kill sclerotia of either Type-l or Type-2. 19. Inhibitory effect on mycelial growth of Benlate or Tachi-garen in the liquid culture increased as the concentration increased. 6 days after application, obvious inhibitory effects were found in all treatments except Benlate 0.5ppm; but after 12 days, distingushed diflerences were shown among the different concentrations. As compared with the control, mycelial growth was inhibited by $66\%$ at 0.5ppm and by $92\%$ at 2.0ppm of Benlate, and by$54\%$ at 1ppm and about $77\%$ at 1.5ppm or 2.0ppm of Tachigaren. The mycelial growth was inhibited completely at 500ppm of both fungicides, and the formation of sclerotia was checked at 1,000ppm of Benlate ant at 500ppm or 1,000ppm of Tachigaren. 20. Consumptions of glucose or ammonium nitrogen in the culture solution usually increased with the increment of mycelial growth, but when Benlate or Tachigaren were applied, consumptions of glucose or ammonium nitrogen were inhibited with the increment of concentration of the fungicides. At the low concentrations of Benlate (0.5ppm or 1ppm), however, ammonium nitrogen consumption was higher than that of the ontrol. 21. The amount of mycelia produced by consuming 1mg of glucose or ammonium nitrogen in the culture solution was lowered markedly by Benlate or Tachigaren. Such effects were the severest on the third day after their treatment in all concentrations, and then gradually recovered with the progress of time. 22. In the sand culture, mycelial growth was not inhibited. It was indirectly estimated by the amount of $CO_2$ evolved at any concentrations, except in the Tachigaren 100mg/g sand in which mycelial growth was inhibited significantly. Sclerotial production was completely depressed in the 10mg/g sand of Benlate or Tachigaren. 23. There was no visible inhibitory effect on the germination of sclerotia when the sclerotia were dipped in the solution 0.1, 1.0, 100, 1.000ppm of Benlate or Tachigaren for 10 minutes or even 20 minutes.

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