• Title/Summary/Keyword: Regrowth

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Controlling Bacterial Regrowth Potential by the Limitation of Nutrients in Drinking Water (영양원의 제한에 의한 수돗물에서의 세균재증식능 억제)

  • Oh, Jung-Woo
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.4
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    • pp.431-437
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    • 2005
  • In this study, the profiles of the bacterial regrowth of indigenous bacteria in tap water and Pseudomonas fluorescence P17 were investigated for cases when carbon (glucose), and/or nitrogen ($NO_3^-$-N), and/or phosphorus ($PO_4^{3-}$-P) were added below sufficient nutrient concentration (SNC) and when carbon sources (glucose and acetate) and nitrogen sources ($NH_4^+$-N and $NO_3^-$-N) were added together. The bacterial regrowth was decreased with limitation of nutrients, and were lowered relatively in the sample, which plural nutrients were limited. In addition, phosphate might be the effective nutrient to control the bacterial regrowth in drinking water because the bacterial regrowth was significantly decreased by the limitation of phosphate. In contrast, the bacterial regrowth was retarded with increasing the concentration of $NO_3^-$-N. For simultaneously adding carbon(glucose or acetate) and nitrogen sources ($NH_4^+$-N and $NO_3^-$-N), the regrowth counts appeared highly in the condition, for both glucose and acetate. And, the regrowth was increased with increasing $NH_4^+$-N concentration as a nitrogen source.

Effect of GA, IAA, Kinetin on Plant Regrowth of Sorghum(Sorghum vulgare Per.) and Pearlmillet (Pennisetum typhoides Stapf.) after Cut (지베레린, 오옥신, 카이네틴 처리가 수수 및 진주조의 재생에 미치는 영향)

  • 서종호;이호진
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.37 no.2
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    • pp.141-148
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    • 1992
  • Field experiment was carried out to investigate the effect of plant growth regulator (PGR); IAA, GA, Kinetin to regrowth of sorghum and pearlmillet according to variety and plant growth stage. Kinetin application after cut increased tiller number and decreased dry weight of regrowth, but its application on sorghum stubble in water stress increased tiller number and leaf elongation rate, consequently increased regrowth dry weight. GA application reduced tiller production in both species, but tiller formation in pearlmillet was decreased more than in sorghum by promoting leaf elongation of old tiller. Nonstructural carbohydrate (NSC) of stubble during regrowth was consumed less at anthesis than at stem elongation stage because of senescence of tiller primordia. GA treatment reduced NSC content more than other PGR in both plant species, by consuming reserve NSC and stimulating rapid elongation of old tiller after cut. Dry matter increase during regrowth had high correlation with tiller number and tiller elongation a week after cut, while it did not have any correlation with NSC at cutting stage or with consumption of NSC during regrowth. Therefore, regrowth in sorghum and pearmillet must depend upon activity of tiller primordia more than upon amount of reserved NSC.

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Analysis of Data Spectral Regrowth from Nonlinear Amplification

  • Amoroso, Frank;Monzingo, Robert A.
    • Journal of Communications and Networks
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    • v.1 no.2
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    • pp.81-85
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    • 1999
  • The regrowth of OQPSK power spectral sidelobes from AM/AM and AM/PM amplifier nonlinearity is analyzed. The time-domain expression for amplifier output shows how spectral re-growth will depend on the cubic coefficient of the Taylor's series of the amplifier nonlinearity as well as input amplitude ripple. Closed form spectrum calculations show that the spectral sidelobes produced by AM/PM take the same form as those produced by AM/AM. The rate of growth of AM/PM sidelobes is, however, not as great as for AM/AM.

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The Inactivation and Microbial Regrowth Inhibition of Heterotrophic and Nitrifying Bacteria by Chloramination (클로라민 소독에 의한 종속영양세균과 질산화세균의 불활성화 및 재성장 억제)

  • 조관형;김평청;우달식;조영태
    • Journal of Environmental Science International
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    • v.10 no.3
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    • pp.247-252
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    • 2001
  • This study was performed to evaluate the inactivation and microbial regrowth of heterotrophic and nitrifying bacteria using chloramine as a secondary disinfectant for drinding water distribution system. Three sets of the three reactors filled with the $Cl_2/NH_3-N$ ratio of 3:1, 4:1, and 5:1 were used in these experiments. Chloramine concentration were applied to each set of the reactors with $1mg/\ell$,\;2mg/\ell\;and\;3mg/\ell$, respectively. For the set with elapsed time and reached to zero level after 7 days. Heterotrophic bacteria remarkably increased and nitrification through the experimenatal period (21 day). Furthermore the regrowth of heterotrophic bacteria and nitrification were not found. More than $2mg/\ell$ of chloramine with $Cl_2/NH_3-N$ ratio of 3:1, the nitrification could be inhibited by 2 days of contact time.

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An Experimental Study on the Effects of Sineungyangjin-Dan Applied to the Treatment of Alopecia (脫毛에 應用되는 神應養眞丹의 效能에 關한 實驗的 硏究)

  • Kim, So-Yeong;Kim, Jung-Ho;Chae, Byeong-Yun
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.4 no.1
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    • pp.43-58
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    • 1991
  • In order to verify the effect of Sineungyangjin-Dan on alopecia, I experimented the hair regrowth of the normal mice and of the high butter diet-pretreated mice by feeding each group of mice a certain amount of ethanol extract of Sineungyangjin-Dan and water extract and thus obtained the results as follow; 1. The ethanol extract of Sineungyangjin-Dan was proved to promote the hair regrowth of the hair-removed normal mice. 2. 360mg/kg ethanol extract of Sineungyangjin-Dan was proved to have the effect of promoting hair regrowth by restraining the increase of free cholesterol and triglyceride but by helping the increase of free fatty acid in skin. As a result of the above study Sineungyangjin-Dan was proved to have the effect of promoting hair regrowth.

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Changes in Non-Structural Carbohydrate Contents and Amylolytic Enzymes Activities during Regrowth after Cutting in Medicago sativa L. (알팔파 예취후 재생시 비구조탄수화물 함량 및 전분 분해 효소활력의 변화)

  • Tae Hwan, Kim;Byung Ho, Kim
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.41 no.5
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    • pp.542-550
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    • 1996
  • An experiment with alfalfa (Medicago sativa L.) plants was designed to investigate the changes in non-structural carbohydrate (NSC) contents and the activities of amylolytic enzymes during a regrowth period following defoliation. Sampling from hydroponic grown-plants were carried out at intervals during 24 days of regrowth. Shoot regrowth was very slow during the first 10 days and root growth was depressed after defoliation. Defoliation induced a great decrease in both total sugar and starch contents in taproots during the first 10∼14 days. A major recovery of NSC occurred from day 15. Averaged over sampling dates, the activity of exo-amylase was about 400-fold higher than that of endo-amylase. Exo-amylase activity in defoliate plants slightly increased until day 6 (maximum level) and then decreased. Endo-amylase rapidly increased for the first 4 days after defoliation and slightly increased afterwards to a maximum on day 24. These results showed that increase in amylolytic enzyme activity in taproots coincided with the time of starch utilization during regrowth and that indicated it plays an important role in starch degradation.

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Comparison of Bacterial Regrowth on Plant- and Coal-based Granular Activated Carbon (식물계활성탄과 석탄계활성탄에서의 세균재생장 비교)

  • 이동근;박성주;하배진;하종명;이상현;이재화
    • KSBB Journal
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    • v.19 no.2
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    • pp.104-109
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    • 2004
  • Activated carbon has been used in water treatment, because they strongly adsorb organic material including contaminant. Water purifier usually use activated carbon, and bacterial regrowth on that could induce many problems. Model columns, packed with coal- and plant-based granular activated carbon (GAC), were operated with rechlorinated tap water to compare the degree of bacterial regrowth on different GACs. GAC columns decreased the concentration of total organic carbon and chlorine, while they are not good for the decrease of ions. Breakthrough of bacteria were occurred after eight days of operation, and reached 1.1 ${\times}$ 10$^3$ CFU/mL on coal based GAC and 6.2 ${\times}$ 10$^2$ CFU/mL on coconut based one. Bacterial activities on GAC were between 15.35 ∼ 29.06 $\mu\textrm{g}$ INT-formazan/g-GAC/h. Bacterial concentration and activities were higher in coal based GAC than coconut based one. Bacterial regrowth on GAC was clarified and regrowth effect of coal-based GAC was higher than that of coconut-based one.

Acidification of pig slurry effects on ammonia and nitrous oxide emissions, nitrate leaching, and perennial ryegrass regrowth as estimated by 15N-urea flux

  • Park, Sang Hyun;Lee, Bok Rye;Jung, Kwang Hwa;Kim, Tae Hwan
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.3
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    • pp.457-466
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    • 2018
  • Objective: The present study aimed to assess the nitrogen (N) use efficiency of acidified pig slurry for regrowth yield and its environmental impacts on perennial ryegrass swards. Methods: The pH of digested pig slurry was adjusted to 5.0 or 7.0 by the addition of sulfuric acid and untreated as a control. The pig slurry urea of each treatment was labeled with $^{15}N$ urea and applied at a rate of 200 kg N/ha immediately after cutting. Soil and herbage samples were collected at 7, 14, and 56 d of regrowth. The flux of pig slurry-N to regrowth yield and soil N mineralization were analyzed, and N losses via $NH_3$, $N_2O$ emission and $NO_3{^-}$ leaching were also estimated. Results: The pH level of the applied slurry did not have a significant effect on herbage yield or N content of herbage at the end of regrowth, whereas the amount of N derived from pig slurry urea (NdfSU) was higher in both herbage and soils in pH-controlled plots. The $NH_4{^+}-N$ content and the amount of N derived from slurry urea into soil $NH_4{^+}$ fraction ($NdfSU-NH_4{^+}$) was significantly higher in in the pH 5 plot, whereas $NO_3{^-}$ and $NdfSU-NO_3{^-}$ were lower than in control plots over the entire regrowth period. Nitrification of $NH_4{^+}-N$ was delayed in soil amended with acidified slurry. Compared to non-pH-controlled pig slurry (i.e. control plots), application of acidified slurry reduced $NH_3$ emissions by 78.1%, $N_2O$ emissions by 78.9% and $NO_3{^-}$ leaching by 17.81% over the course of the experiment. Conclusion: Our results suggest that pig slurry acidification may represent an effective means of minimizing hazardous environmental impacts without depressing regrowth yield.

Comparative nitrogen use efficiency of urea and pig slurry for regrowth yield and nutritive value in perennial ryegrass sward

  • Park, Sang Hyun;Lee, Bok Rye;Cho, Won Mo;Kim, Tae Hwan
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.4
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    • pp.514-522
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    • 2017
  • Objective: The study aimed to assess the N use efficiency (NUE) of pig slurry (in comparison with chemical fertilizer) for each regrowth yield and annual herbage production and their nutritive value. Methods: Consecutive field experiments were separately performed using a single application with a full dose of N (200 kg N/ha) in 2014 and by four split applications in 2015 in different sites. The experiment consisted of three treatments: i) control plots that received no additional N, ii) chemical fertilizer-N as urea, and iii) pig-slurry-N with five replicates. Results: The effect of N fertilization on herbage yield, N recovery in herbage, residual inorganic N in soil, and crude protein were significantly positive. When comparing the NUE between the two N sources (urea and pig slurry), pig slurry was significantly less effective for the earlier two regrowth periods, as shown by lower regrowth dry matter (DM) yield, N amount recovered in herbage, and inorganic N availability in soil at the 1st and 2nd cut compared to those of urea-applied plots. However, the effect of split application of the two N sources was significantly positive at the last two regrowth periods (at the 3rd and 4th cut). The two N sources and/or split application had little or no influence on neutral detergent fiber (NDF) content, acid detergent fiber (ADF) content, and in vitro DM digestibility, whereas cutting date was a large source of variation for these variables, resulting in a significant increase in in vitro DM digestibility for the last two regrowth periods when an increase in NDF and ADF content occurred. Split application of N reduced the N loss via nitrate leaching by 36% on average for the two N sources compared to a single application. Conclusion: The pig slurry-N was utilized as efficiently as urea-N for annual herbage yield, with a significant increase in NUE especially for the latter regrowth periods.

Effect of Bensulfuron-methyl on Bud Sprout and Regrowth from Growth Cessation in Eleocharis kuroguwai (올방개 괴경(塊莖)의 맹아(萌芽)와 재생후(再生後) 생육(生育)에 미치는 Bensulfuron-methyl 의 영향(影響))

  • Shin, H.S.;Chun, J.C.;Lee, C.K.
    • Korean Journal of Weed Science
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    • v.12 no.1
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    • pp.1-7
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    • 1992
  • The experiment was conducted to investigate effects of bensulfuron-methyl{methyl 2-((((((4,6-dimethoxypyrimidin-2-yl)amino)carbony)amino)sulfonyl)methyl)benzoate}on bud sprouting, percent regrowth, and regrowth from growth cessation in Eleocharis kuroguwai. Application of bensulfuron-methyl resulted in sprouts of two of three lateral buds in addition to the apical bud of E. kuroguwai. With bensulfuron-methyl the culms elongated from the sprouted buds were killed soon after emergence. However, the buds remained biologically active. During the period of growth cessation the tuber buds respired in a minimum rate, but respiration began to increase with regrowth. At regrowth increase in the respiration was greater in the lateral buds than in the apical bud. Days required to regrowth was 35 days in the suppressed apical bud when applied at the rate of 51 g a. i. ha bensulfuron-methyl, while the suppressed lateral buds sprouted first and second required 29 and 28 dyas, respectively. After regrowth number of new culms was two to three times greater in the lateral buds than in the apical bud.

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