• Title/Summary/Keyword: 경시변화

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Studies on the Salt Movement of Upland Soil in Reclaimed Tidal Land (간척지(干拓地) 밭토양(土壤)의 염류이동(鹽類移動)에 관(關)한 연구)

  • Lee, Jong-Sik;Kim, Jong-Gu;Yoo, Chul-Hyun;Kang, Jong-Gook;Kim, Ho-Jung
    • Korean Journal of Soil Science and Fertilizer
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    • v.24 no.1
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    • pp.28-34
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    • 1991
  • This study was carried out to investigate the salt movement in upland soils in reclaimed region (Kye-Hwa Do). The results obtained were summarized as follows : 1. The cation content in ground water increased during time course. but in the case of land-surface water the content was variable, and $K^+$ was lower than that of $Na^+$ and $M^{+2}$. At the L. S. P(Low salinity plot) under rainproof condition, the salinity was directly proportional to soil water content, but at the H. S. P (High salinity plot) the tendency was no reversed. 3. In condition of rainproof, the amount of available phosphorous was higher at the H. S. P than at the L. S. P. 4. Positive correlation was obtained between the soil water content and available phosphorous content at the rainfall plot, but there was no significance at the surface soil of the rainproof plot. 5. SAR (Sodium adsorption ratio) and anion ($Cl^-$, $SO_4{^{2-}}$) contents in soil were repressed in the order of black vinyl>white vinyl>rice straw>control.

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Studies on Management of Effective Temperature and Humidity in Greenhouse at Summer Season (하절기 효율적인 하우스 온도 습도 관리에 관한 연구)

  • 우영회;남윤일;송천호;김형준;김동억
    • Journal of Bio-Environment Control
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    • v.3 no.1
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    • pp.58-65
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    • 1994
  • It is necessary to effective temperature and humidity management for normal growth of crops in protected cultivation during the summer season. Because the highest temperature of vinyl house inhibit normal growth of crop and decrease of crop production or marketability in summer season. Finally, the vinyl house was impossible some crop cultivation in summer season. This study was conducted to investigate effective and economic method for temperature drop in protected cultivation during the summer season. 1. In medium size vinyl house(5$\times$13$\times$3m), the effect of temperature drop appeared the highest in treatment of shading with aluminium thermal curtain+fog system+ventilation with fan. The effect of temperature drop was about 1$0^{\circ}C$ lower than outer air temperature and about 4$^{\circ}C$ lower than outer soil temperature. 2. The effect of temperature drop according to shading with aluminium thermal curtain+fog system+ventilation with fan during the highest temperature of summer season Jul., 20 to Aug., 21 was appeared about 8$^{\circ}C$ lower than outdoor above ground(1.2m) and about 7$^{\circ}C$ lower than outdoor surface ground. 3. The changes of solar radiation during a day according to shading with aluminium thermal curtain+ventilation with fan and shading with black curtain+ventilation with fan treatments was appeared respectively about 29.3%, 32.5% of outdoor solar radiation a fine day and respectively about 27.4%, 31.8% of outdoor solar radiation a cloudy day.

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Effect of Sodium in Artificial substrate on the Growth, Gas Exchange and Leaf Water Status of Cucumber (Cucumis sativa L.) and Korea Melon(Cucumis melo L.) (상토에 함유된 Na함량이 오이와 참외의 생육, 광합성 및 잎의 수분상태에 미치는 영향)

  • Seo, Young-Jin;Kim, Jong-Su;Kim, Chan-Yong;Park, So-Deuk;Park, Man
    • Korean Journal of Soil Science and Fertilizer
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    • v.41 no.3
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    • pp.177-183
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    • 2008
  • Sodium is known to reduce a plant growth and yields. However, the relationships between physiological response of seedling and salinity stress caused by growing media are not well understood yet. We conducted experiments to investigate change of some parameters including Na, EC, moisture content in media under different air temperature ($15^{\circ}C$, $25^{\circ}C$), and the response of fruit-vegetables such as cucumber, oriental melon on saline conditions originated from horticultural substrate. Volumetric moisture content of media at $15^{\circ}C$ was 70%, but at $25^{\circ}C$ was decreased by 45% within 22 hrs, showing below optimal matric potential, approximately. During reaction time, the increase of Na concentration was significantly greater in saline substrate than in control. The decrease rate of Na concentration according to supplying irrigation water was higher in saline substrate than in control. $CO_2$ assimilation rate and transpiration rate of Korea melon grown in low temperature were decreased with a Na/cation ratio in hydroponic solution. Water saturation deficit was also increased significantly at $15^{\circ}C$ as compare to $25^{\circ}C$. Saline stress during nursery stage induced a reduction of seedling quality, growth and cucumber yield. The results suggest that the relationship between uncontrolled Na uptake of seedling from saline substrate and meteological condition is responsible for saline stress.

Change of Soil Microbial Populations after Forest Fire (산불 발생 후 토양 미생물의 밀도 변화)

  • 박동진;육연수;김종진;이상화;김창진
    • Korean Journal of Microbiology
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    • v.35 no.1
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    • pp.78-81
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    • 1999
  • The change of soil microbial populations was studied at the burnt areas of Mt. Jirisan in Hddong-Gun, Kyungsangnam-Do, where the fire had occurred on Oct. 21 in 1997. On the first day of the fireextinguished, the microbial density (CFUIg dry soil) was investigated at the surface, 5 cm, 10 cm, 20cm, and 30 cm depth of soils. Bacteria at the surface and 5cm depth of burnt sites were estimatedwith the low density level of $10^2$ CFW/g soil comparing to the $10^6$ CFUIg soil of the neighboring unburntsites. Actinomycetes of burnt sites were completely disappeared at the surface, and were estimatedwith the low density level of $10^3$ CFUig soil at thc 5 cm depth comparing to the 10"CFUigsoil at the depth of unburnt sites. Fungi wcrc not isolated at the surface and 5 cm depth at all.However, the rarest lire was not found to decrease the microbial populalions at the lower depths than10 cm. In addilion, the recovery or soil microbial populations following the fire was bimonthly investigatedat the surrace and 5 cm depth. Most of microbial densities at the burnt sites were greatlyincreased two months after the fire, being enough to he compared with the neighboring unburnt sites.However, actinomycetes only at the surface of burnt sites still were estimated the low density level of$10^4$ CFUig soil 4 months after the fire comparing to the $10^6$CFIg soil of unburnt sites.TEX>CFIg soil of unburnt sites.

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Studies on peptides during soybean-koji preparation -part I Peptides formation during soybean-koji preparation- (콩고오지 제조중(製造中)의 peptide에 관(關)한 연구(硏究) -제1보(第一報) 콩고오지 제조중(製造中)의 peptide의 소장(消長)-)

  • Kim, Ze-Uook
    • Applied Biological Chemistry
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    • v.6
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    • pp.79-87
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    • 1965
  • The contents of insoluble protein nitrogen, water soluble protein nitrogen anti peptides' nitrogen were determined of the samples which were taken in seven and half hours intervals during soybean-koji preparation to study changes of soybean protein, and the contents of total nitrogen and amino nitrogen were measured for the fractions resulting from molecular sieving by using Dowex 50 having various cross linkages for the peptides from soybean-koji extracts. As the results of the studies, The followings were obtained: 1. The contents of insoluble protein nitrogen and peptides' nitrogen are fairy constant at the earlier stage, where the former decreased and the latter increased markedly as mycelia grow, then rate of the decreases and the increases of them become lower at later stage after sporulation. The contents of water soluble protein are also constant at the earlier stage until covering of mycelia over the koji and increased since then until the stage of sporulation and then decreased at the later stage. 2. The amount of peptides nitrogen in each fraction obtained by the molecular sieving was almost constant at the earlier stage and the values in fractions of X-16, X-12, X-8. X-4 and X-2 increased considerably together as mycelia grow. Then the values in the fractions showed almost plateaux, after sporulalion, where the effluent fraction showed markedly increased values throughout mycelia growth.

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A preliminary study to determine the order of the latent fingerprint deposition on thermal paper - A short term study - (감열지상 잠재지문의 남겨진 순서결정에 대한 예비적 연구 - 단기연구 -)

  • Lim, Dong-A;Ok, Yun-Seok;Heo, Bo-Reum;Choi, Sung-Woon
    • Analytical Science and Technology
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    • v.30 no.5
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    • pp.279-286
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    • 2017
  • Determination of the order of latent fingerprints deposition on the surface of thermal paper, often found in crime scenes, is related to the study of time course and aging of fingerprints and can provide additional information in criminal investigations. A preliminary study was performed to determine the deposition order of fingerprints left with two different conditions of deposition pressure and time (in seconds) after 1 day intervals for 7 days on thermal paper (receipt and fax thermal paper) using an iodine fuming method. The resultant images of the visualized fingerprints were analyzed with densitometric image analysis to measure the changes in the areas of the ridges, which can be correlated to the deposition order. No significant variation was found with the different types of thermal paper. The average areas of the friction ridges increased gradually or were similar to the values from day 1 for 3 days, and then a continual decrease was shown from day 4 through day 7. The area values from day 6 and day 7 were less than half of those from day 1. Furthermore, the test with overlapped fingerprints showed the possibility of differentiation between fingerprints that are 1-3 and 6-7 days old based on the clarity visible to the naked eye. Additional experiments with the deposition conditions can prove that the current method is valuable for the determining the order of fingerprint deposition on thermal paper.

Stability of Lipids in Ramyon (deep fat fried instant noodle) -I. Oxidative Changes in the Ramyon Lipids during Storage- (라면 유지(油脂)의 안전성(安定性)에 관한 연구(硏究) -(I) 시험저장중(試驗貯藏中) 라면유지(油脂)의 산패(酸敗)에 대(對)하여-)

  • Cheigh, Hong-Sik;Kwon, Tai-Wan
    • Korean Journal of Food Science and Technology
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    • v.4 no.4
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    • pp.259-264
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    • 1972
  • Oxidative changes of the Ramyon lipids were studied under three experimental storage conditions. Ramyon was 1) exposed to fluorescent light irradiation at $25^{\circ}C$, 2) incubated in the dark at $40^{\circ}C$ and 3) irradiated with ultra-violet light at $25^{\circ}C$. In the study, changes in acid value, peroxide value, carbonyl value, TBA number, fatty acid composition and iodine value were determined with the lipids extracted from the Ramyon samples in intervals for a period of 20 weeks. Acid value, peroxide value, and TBA number of the samples under fluorescent light irradiation and $40^{\circ}C$ incubation increased slightly during storage, while a sharp increase of those values were noticed with the samples of ultra-violet light irradiation. Especially, the TBA number of the Ramyon lipid under ultra-violet light irradiation markedly increased within 10 weeks and then decreased. With this change in TBA number, however, the bound form of malonaldehyde increased gradually. During the storage under $40^{\circ}C$ incubation, and ultra·violet irradiation for 10 weeks, the content of linoleic and linolenic acids decreased, while palmitic and stearic acids increased. However, only small changes were noticed in iodine value of the samples. On the other hand, oxidative rancid odor appeared at the end of 16 weeks storage under fluorescent light irradiation and $40^{\circ}C$ incubation, while it took only 4 weeks with the sample stored under ultra-violet irradiation.

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Effects of Yeast Addition as Starter on Fermentation of Kimchi (효모 Starter 의 첨가가 김치발효에 미치는 영향)

  • Kim, Hye-Ja;Kang, Sang-Mo;Yang, Cha-Bum
    • Korean Journal of Food Science and Technology
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    • v.29 no.4
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    • pp.790-799
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    • 1997
  • The purpose of this study is to investigate the effects of yeast addition as starter on kimchi fermentation. The strains used as starter were Saccharomyces sp. YK-17 and Saccharomyces fermentati YK-19 isolated from kimchi, grew under anaerobic condition and low temperature, which showed the acid and base resistances. Chemical and microfloral changes, as well as the sensory properties of starter added kimchi during fermentation were compared with the control fermented without starter. The acidity of kimchi juice was lower and pH was higher in starter added kimchi than the control. Particularly addition of S. fermentati YK-19 prolonged the optimally fermented period (pH 4.0, acidity $0.6{\sim}0.8%$) up to more than 63%. The content of lactic acid, the major non-volatile organic acid in kimchi, was increased rapidly followed by S. sp. YK-17 and S. fermentati YK-19 group. The microfloral changes were found a little different among the samples. Among the microorganisms, Leuconostoc sp. and Lactobacillus sp. showed highest change, and Streptococcus sp. and Pediococcus sp. showed ralatively low change. The growth of Lactobacillus sp. which was the main acidifing microorganism was inhibited by starter addition, particularly by S. fermentati YK-19. The sensory characteristics of acidic and moldy flavor were significantly reduced by the addition, while fresh flavor was increased in starter added group.

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Effects of Paecilomyces tenuipes Water Extract on the Alcohol Metabolism of Rats (눈꽃동충하초 물추출물이 흰쥐의 알코올대사에 미치는 영향)

  • Kim, Ji-Myung;Park, Jae-Hwan;Kim, Mi-Kyung;Chun, Hyang-Sook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.3
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    • pp.396-400
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    • 2008
  • The effect of Paecilomyces tenuipes water extract (PTWE) on the alcohol metabolism was examined on rats. PTWE of 0, 30, 100 mg/kg body weight was administrated orally to the rats 30 min before oral treatment of 3 g/kg body weight of alcohol. Blood alcohol and acetaldehyde concentrations were measured 0.5, 1, 3, 6, 9 hr after alcohol treatment. Hepatic alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ADH), microsomal ethanol oxidizing system (MEOS) activities were measured 9 hr after alcohol treatment. There were no differences in blood alcohol concentrations and area under the curve (AUC) of alcohol. PTWE decreased acetaldehyde concentration and there were significant differences after 6 hr in 30 mg/kg PTWE and after 3 and 9 hr in 100 mg/kg PTWE, respectively. In particular, 100 mg/kg PTWE decreased AUC of acetaldehyde by 44%. However, there were no changes in the hepatic ADH, ALDH, and MEOS activities.

Evaluation of Tightness of Proximal tooth Contact on Implant Prostheses (임프란트 보철수복물에서의 인접치간 접촉강도의 평가)

  • Kim, Sang-Pil;Jung, J-Hyun;Kang, Dong-Wan;Oh, Sang-Ho
    • Journal of Dental Rehabilitation and Applied Science
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    • v.24 no.4
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    • pp.371-379
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    • 2008
  • The aim of this study was to evaluate the tightness of proximal tooth contact(TPTC) using a novel device at rest state on implant prostheses. Ten healthy young adults with class I normal occlusion consented to participate in the study and twenty patients were restored with a total 20 single-implant crowns in the left maxillary and mandibular second molars for 10 single-implant crowns, respectively. Test area were divided by 4 groups. UM describes the contact between the upper natural left first molar and natural second molar; LM the contact between the lower natural left first molar and natural second molar; IUM the contact between the upper natural left first molar and implant second molar and ILM the contact between the lower natural left first molar and implant second molar. The TPTC was measured at rest state in each area. The mean TPTC of the UM, LM, IUM and ILM was 1.48(${\pm}0.44$) N, 1.78(${\pm}0.40$) N, 1.14(${\pm}0.37$) N and 1.30(${\pm}0.32$) N respectively. These results indicate that the TPTC was less between natural tooth and implant prosthesis than between natural teeth.