• 제목/요약/키워드: Pre-concentration

검색결과 1,162건 처리시간 0.024초

Efficacy of Different Seed Kernels against Root Knot Nematode Meloidogyne incognita in Mulberry

  • Chowdary, N.B.;Mukherjee, Sanchayita
    • International Journal of Industrial Entomology and Biomaterials
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    • 제6권2호
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    • pp.133-138
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    • 2003
  • Five seed kernel namely, Neem (Azadirachta indica A. Juss.), Pongamia (Pongamia glabra L. Pierre), Tamarind (Tamarindus indica L.), Mahua (Madhuca indica Gmel.) and Shikakai (Acacia cancinna De.) were tested against hatching of eggs and larval mortality of Meloidogyne incognita causing root knot disease in mulberry along with Furadan (Carbofuran) and Bionema (a bioformulation developed from Verticillium chlamydosporium) for comparison. Results revealed that highest hush-up of hatching was observed in Neem (77.40%) and Pongamia (75.99%) seed kernel extracts at 100% concentration over the check. Similarly, highest larval mortality was observed in Neem and Pongamia by 76.00% and 74.50%, respectively at 100% concentration after 72 hrs of exposure period. Pot culture studies revealed that pre-application of seed kernel powders (20 days before inoculation of nematode) found to be more effective in controlling the root knot disease than post application. In pre application of seed kernel powders, maximum reduction of root knots was observed in case of Neem seed kernel powder (54.85%) followed by Pongamia (51.9%). Similar trend was also observed in reduction of egg masses/plant and nematode population /250 cc soil. Rest of the seed kernel extracts was found to be less effective in suppression of hatching, enhancing the larval mortality and controlling the root knot disease. However, application of Furadan and Bionema tested for the comparison were found to be more effective than seed kernel powders. The generated information seems to be useful in developing an ecofriendly integrated approach for the control of root knot nematode disease in mulberry.

후박나무껍질을 이용한 견직물의 염색성 (Dyeability of Silk Fabrics with Machilus thunbergii Cortex)

  • 한미란;이정숙
    • 한국의류학회지
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    • 제34권5호
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    • pp.866-872
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    • 2010
  • This study investigates the methods of the natural dyeing of silk fabrics with Machilus thunbergii cortex extract. After the dyeing of silk with a Machilus thunbergii cortex extract, the dyeability of the Machilus thunbergii cortex extract was evaluated with the dyeing time, concentration, temperature, the numbers of repeated dyeing, the pH of the dyebath, the changes of the K/S value, and surface colors by the methods of mordanting and color fastness. The effective dyeing conditions with silk fabrics were at a concentration of 120g/L, the dyeing temperature at $80^{\circ}C$, and the dyeing time for one hour ten minutes. The effective number of repeated dyeing was three times. The dyeing operation was carried out in a neutral dyebath of pH 7. The K/S value was higher in most of the pre-mordants (except the Sn mordant) and a high K/S value was shown in the copper pre-mordant. The colors of the silk fabrics with Machilus thunbergii cortex were of various brown shades. The color difference was distinct when using the Fe-mordant and the colorfastness of all the dyed samples was low; however, the dry cleaning fastness was excellent at the 4-5 grade.

Herbicidal Activity of $\delta$-aminolevulinic Acid on Several Plants as Affected by Application Methods

  • Chon, Sang-Uk
    • 한국작물학회지
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    • 제48권1호
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    • pp.50-55
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    • 2003
  • Herbicidal activity of $\delta$-aminolevulinic acid(ALA), an intermediate for the biosynthesis of tetrapyrroles such as chlorophyll, heme, bacteriochlorophyll, and vitamin $\textrm{B}_{12}$ analogues, was examined to determine the variation in phytotoxic potential against different plant species as affected by different application methods. Seed-soaking treatment, ALA at low concentrations did not affect shoot and root lengths of test plants while at highest concentration reduced them by 20 to 30%. Alfalfa showed the most tolerant response to ALA in both pre- and post-emergence application, and followed by rice. When applied with pre-emergence, cotyledons of Chinese cabbage were severely bleached with 0.5 mM of ALA at 24 hrs after application, and root growth of rice, barnyard grass, and alfalfa was significantly inhibited with increasing of concentration. With post-emergence application, ALA at 2 to 4 mM reduced shoot and root growths of Chinese cabbage and barnyard grass completely. Herbicidal effects of ALA were more enhanced in the treatment combined with 2,2-dipyridyl sthan single application in barnyard grass and Chinese cabbage. The results suggest that alfalfa was the most tolerant to ALA among the tested plants, and that post-emergence application of ALA exhibited greatest photodynamic activity against tested plants.

Adsorptive Removal of Phosphate Ions from Aqueous Solutions using Zirconium Fumarate

  • Rallapalli, Phani B.S.;Ha, Jeong Hyub
    • 공업화학
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    • 제31권5호
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    • pp.495-501
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    • 2020
  • In this study, zirconium fumarate of metal-organic framework (MOF-801) was solvothermally synthesized at 130 ℃ and characterized through powder X-ray diffraction (PXRD) analyses and porosity measurements from N2 sorption isotherms at 77 K. The ability of MOF-801 to act as an adsorbent for the phosphate removal from aqueous solutions at 25 ℃ was investigated. The phosphate removal efficiency (PRE) obtained by 0.05 g/L adsorbent dose at an initial phosphate concentration of 60 ppm after 3 h was 72.47%, whereas at 5 and 20 ppm, the PRE was determined to be 100% and 89.88%, respectively, after 30 min for the same adsorbent dose. Brunauer-Emmett-Teller (BET) surface area and pore volume of the bare MOF-801 sample were 478.25 ㎡/g and 0.52 ㎤/g, respectively, whereas after phosphate adsorption (at an initial concentration of 60 ppm, 3 h), the BET surface area and pore volume were reduced to 331.66 ㎡/g and 0.39 ㎤/g, respectively. The experimental data of kinetic (measured at initial concentrations of 5, 20 and 60 ppm) and isotherm measurements followed the pseudo-second-order kinetic equation and the Freundlich isotherm model, respectively. This study demonstrates that MOF-801 is a promising material for the removal of phosphate from aqueous solutions.

과망간산칼륨 용액에서 화학적으로 형성된 AZ31B 마그네슘 합금의 피막 특성평가 (Characteristics of Films Formed on AZ31B Magnesium Alloy by Chemical Oxidation Process in Potassium Permanganate Solution)

  • 김민정;김형찬;윤석영;정우창
    • 한국표면공학회지
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    • 제44권2호
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    • pp.44-49
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    • 2011
  • The films formed on AZ31B magnesium alloy were prepared from alkaline solution composed of potassium permanganate and sodium hydroxide. The immersion tests were carried out at the different concentration of sodium hydroxide and pre-treatment method in 5 minute. The morphology and the phase composition of the film were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The corrosion behavior of the film in 5.0% NaCl solution was evaluated using potentiodyanmic polarization. Open circuit potential in developing film was examined with time. The thin and transparent film was mainly composed of MgO and $Mg(OH)_2$. The film with the best corrosion resistance was obtained at $70^{\circ}C$ bath temperature, 1.6 M concentration of sodium hydroxide and chemical pre-treatment.

Effects of electronic energy deposition on pre-existing defects in 6H-SiC

  • Liao, Wenlong;He, Huan;Li, Yang;Liu, Wenbo;Zang, Hang;Wei, Jianan;He, Chaohui
    • Nuclear Engineering and Technology
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    • 제53권7호
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    • pp.2357-2363
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    • 2021
  • Silicon carbide is widely used in radiation environments due to its excellent properties. However, when exposed to the strong radiation environment constantly, plenty of defects are generated, thus causing the material performance downgrades or failures. In this paper, the two-temperature model (2T-MD) is used to explore the defect recovery process by applying the electronic energy loss (Se) on the pre-damaged system. The effects of defect concentration and the applied electronic energy loss on the defect recovery process are investigated, respectively. The results demonstrate that almost no defect recovery takes place until the defect density in the damage region or the local defect density is large enough, and the probability of defect recovery increases with the defect concentration. Additionally, the results indicate that the defect recovery induced by swift heavy ions is mainly connected with the homogeneous recombination of the carbon defects, while the probability of heterogeneous recombination is mainly dependent on the silicon defects.

청소년 흡연자를 위한 금연건강캠프의 효과 (The Effects of a Smoking Cessations Health Camp among Adolescent Smokers)

  • 백경신;권영숙
    • 동서간호학연구지
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    • 제16권2호
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    • pp.105-112
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    • 2010
  • Purpose: This study was aimed at evaluating the effects of a smoking cessations health camp on levels of expiratory Carbon Monoxide concentration, self-efficacy, smoking knowledge and nicotine dependence among adolescents smokers. Methods: This research uitlized a one group pre-test post-test design. The smoking cessations health camp was developed after considering cognitive and behavioral aspects and was provided for two days and one night. The number of subjects was 31 high school students. Data were analyzed using descriptive analysis and paired t-test. Results: As compared to a pre-test, the average score of expiratory CO concentration and nicotine dependence were significantly lower and the average score of smoking knowledge was significantly higher in a post-test. An increase in the mean score of self-efficacy was not statistically significant. Conclusion: These results suggest that this smoking cessations health camp can provide teen smokers with the insightful antismoking information and an opportunity for anti-smoking practices. Therefore, this smoking cessations health camp can be effective and useful for adolescent smokers in other school settings.

Single-stranded DNA Enhances the Rate of Product Release During Nucleotide Hydrolysis Reaction by T7 DNA Helicase

  • Kim, Dong-Eun;Jeong, Yong-Joo
    • Bulletin of the Korean Chemical Society
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    • 제27권10호
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    • pp.1618-1622
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    • 2006
  • Bacteriophage T7 gp4A' is a ring-shaped hexameric DNA helicase that catalyzes duplex DNA unwinding using dTTP hydrolysis as an energy source. To investigate the effect of single-stranded DNA (ssDNA) on the kinetic pathway of dTTP hydrolysis by the T7 DNA helicase complexed with ssDNA, we have first determined optimal concentration of long circular M13 single-stranded DNA and pre-incubation time in the absence of $Mg^{2+}$ which is necessary for the helicase-ssDNA complex formation. Steady state dTTP hydrolysis in the absence of $Mg^{2+}$ by the helicase-ssDNA complex provided $k_{cat}$ of $8.5\;{\times}\;10^{-3}\;sec^{-1}$. Pre-steady state kinetics of the dTTP hydrolysis by the pre-assembled hexameric helicase was monitored by using the rapid chemical quench-flow technique both in the presence and absence of M13 ssDNA. Pre-steady state dTTP hydrolysis showed distinct burst kinetics in both cases, indicating that product release step is slower than dTTP hydrolysis step. Pre-steady state burst rates were similar both in the presence and absence of ssDNA, while steady state dTTP hydrolysis rate in the presence of ssDNA was much faster than in the absence of ssDNA. These results suggest that single-stranded DNA stimulates dTTP hydrolysis reaction by T7 helicase by enhancing the rate of product release step.

수소 첨가가 예혼합 메탄 화염의 NOx 생성에 미치는 영향 (Hydrogen Enrichment Effects on NOx Formation in Pre-mixed Methane Flame)

  • 김한석;안국영
    • 한국수소및신에너지학회논문집
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    • 제18권1호
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    • pp.75-84
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    • 2007
  • The effects of hydrogen enrichment to methane on NOx formation have been investigated with swirl stabilized pre-mixed hydrogen enriched methane flame in a laboratory-scale pre-mixed combustor(nominally of 5,000 kcal/hr). The hydrogen enriched methane fuel and air were mixed in a pre-mixer and introduced to the combustor through different degrees of swirl vanes. The flame stability was examined for different amount of hydrogen addition to the methane fuel, different combustion air flow rates and swirl strengths by comparing equivalence ratio at the lean flame limit. The hydrogen addition effects and swirl intensity on the combustion characteristics of pre-mixed methane flames were examined using gas analyzers, and OH chemiluminescence techniques to provide information about species concentration of emission gases and flowfield. The results of NOx and CO emissions were compared with a diffusion flame type combustor. The results show that the lean stability limit depends on the amount of hydrogen addition and the swirl intensity. The lean stability limit is extended by hydrogen addition, and is reduced for higher swirl intensity at lower equivalence ratio. The addition of hydrogen increases the NOx emission, however, this effect can be reduced by increasing either the excess air or swirl intensity. The NOx emission of hydrogen enriched methane premixed flame was lower than the corresponding diffusion flame under the fuel lean condition.

초음파가 폐활성 슬러지의 혐기성 소화에 미치는 영향(I) -초음파 및 알칼리 전처리를 이용한 폐활성 슬러지의 가용화- (Effect of Sonification on the Ananerobic Digestion of Waste Activated Sludge(I) -Disintegration of Waste Activated Sludge Using Ultrasonic and Alkaline Pre-treatments-)

  • 한선기;이채영
    • 유기물자원화
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    • 제17권1호
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    • pp.96-102
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    • 2009
  • 본 연구에서는 혐기성 소화 성능 향상을 위해 초음파 및 알칼리 전처리에 의한 폐활성 슬러지의 가용화 효과를 조사하였다. 초음파 및 알칼리 전처리는 세포벽의 파괴로 인하여 모세관 흡입 시간을 증가시킬 뿐만 아니라 상등액의 용존성 화학적 산소요구량, 단백질 및 탁도 농도를 증가키는 것으로 나타났다. 알칼리와 초음파 전처리를 병행한 슬러지 가용화가 초음파 전처리만을 수행한 경우에 비해 용존성 화학적 산소요구량과 단백질 증가가 높은 것으로 나타났다. 알칼리와 초음파 전처리를 동시에 수행한 경우 폐활성 슬러지의 고형물 농도 증가에 따라 가용화 효율이 감소하는 것으로 조사되었다.