• Title/Summary/Keyword: Mixed solution

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Changes of Nitrogen Uptake, Growth and Activities of Nitrogen Metabolizing Enzymes by Different Source of Nitrogen in Tobacco (담배에서 질소 형태에 따른 흡수 양상 및 생육과 질소대사 효소의 활성 변화)

  • 이상각;심상인;강병화;배길관
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.42 no.5
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    • pp.515-521
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    • 1997
  • Tobacco plant was grown for 40 days hydroponically in nutrient solutions composed of different forms of nitrogen, like NO$_3$$^{[-10]}$ -N, NH$_4$$^{+}$-N, and a mixed formulation of NO$_3$$^{[-10]}$ -N and NH$_4$$^{+}$-N. Uptake response, nitrate reductase, and glutamine synthetase activity at growth stage were investigated to understand the basic knowledge of nitrogen metabolism. The better growth of shoot and root was observed in the mixed nutrient solution than NO$_3$$^{[-10]}$ -N or NH$_4$$^{+}$-N, alone. The plant growth in NH$_4$$^{+}$-N nutrient solution was poor due to ammonium toxicity. The pH of nutrient solution containing NO$_3$$^{[-10]}$ -N increased up to 40 days after transplanting. But the pH of solution containing NO$_3$$^{[-10]}$ -N decreased drastically to 3.42 at 20 days after transplant. The pH in the mixed formulation dropped to pH 3.64 at 30 days after transplant and showed re-increase. It is assumed that nitrogen of NH$_4$$^{+}$-N form was taken up preferentially at early stage and NO$_3$$^{[-10]}$ -N form was taken up preferentially at middle stage in the treatment with the mixed solution. The result indicates that the relative proportion of nitrogen forms affected the uptake patterns at each growth stages. The contents of chlorophyll and soluble protein were high with the mixed solution. Total nitrogen content was the highest in NH$_4$$^{+}$-N solution and the content also increased by the application of the mixed type of nitrogen. The amount of nitrate in leaves was high in NO$_3$$^{[-10]}$ -N treatment and the amount of ammonium was high in NH$_4$$^{+}$-N treatment. The activity of nitrate reductase or glutamine synthetase was highest in the leaves grown in mixed nutrient solution than in those with any other single of nitrogen form.

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Mixed H_2/H_{\infty}$ controller design algorithm for robust performance optimization (견실성능 최적화를 위한 혼합 H_2/H_{\infty}$ 제어기설계 알고리즘)

  • 김종해;방경호;박홍배
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.5
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    • pp.10-16
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    • 1996
  • In this paper, we consider a generalized mixed H_2/H_{\infty}$ output feedback problem. It is finding an internally stabilizing controller that minimizes a mixed $H_{2}$/ $H_{performance}$ measure. We show that a generalized mixed H_2/H_{\infty}$ system with two exogenous inputs and two controlled signals is transformed into auxiliary system with two exogenous inputs and one controlled signal. The two systems have equivalent performance. Therefore, a complete solution of generalized mixed H_2/H_{\infty}$ output feedback problem is achieved by existing results of mixed H_2/H_{\infty}$ control theory.

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Mode Decomposition of Three-Dimensional Mixed-Mode Cracks using the Solution for Penny-Shaped Crack

  • Kim, Young-Jong;Cho, Duk-Sang
    • International Journal of Precision Engineering and Manufacturing
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    • v.2 no.3
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    • pp.11-18
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    • 2001
  • A simple and convenient method of analysis for obtaining the individual stress intensity factors in a three-dimensional mixed mode crack is proposed. The procedures presented here are based on the path independence of J integral and mutual or two-state conservation integral, which involves two elastic fields. The problem is reduced to the determination of mixed mode stress intensity factor solutions in terms of conservation integrals involving known auxiliary solutions. Some numerical examples are presented to investigate the effectiveness and applicability of the method for a three-dimensional penny-shaped crack problem under mixed mode. This procedure is applicable to a three-dimensional mixed mode curved crack.

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Study on Solution Polymerization Behaviors by Mixed Aluminium Compound Catalysts (알루미늄 화합물 혼합촉매계의 L-lactide 용액중합 특성 연구)

  • Yoo, Ji-Yun;Kim, Da-Hee;Ko, Young-Soo
    • Polymer(Korea)
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    • v.36 no.5
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    • pp.593-598
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    • 2012
  • Solution polymerization behaviors of L-lactide using single and mixed aluminium catalyst systems were studied. Triisobutylaluminium (TIBA) was a reference catalyst for mixing. For the $Al(O-i-Pr)_3$/TIBA catalytic systems, the molecular weight of the resulting polylactide (PLA) decreased as the composition of $Al(O-i-Pr)_3$ increased. The higher molecular weight shoulder was revealed in their GPC curve. At TIBA of 80 mol% a bimodal GPC curve was shown. The conversion in the trimethylaluminium (TMA)/TIBA catalysts system decreased as the composition of TMA in the mixed catalyst increased. The conversion in the trioctylaluminium (TOA)/TIBA catalysts system decreased as the composition of TOA in the mixed catalyst increased. The unimodal molecular weight distribution was observed with the TOA/TIBA catalyst systems. The Al compounds-mixed catalyst could produce a higher molecular weight shoulder in the GPC curve.

Analysis of $NO_X$ Conversion Reaction using Platinum supported on Alumina (알루미나에 담지된 플라티늄을 이용한 $NO_X$의 전환반응에 미치는 요인 분석)

  • Ahn, Beom-Shu
    • Journal of the Korean Applied Science and Technology
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    • v.22 no.2
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    • pp.168-174
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    • 2005
  • Aluminum tri-butoxide was mixed with the water/ethanol solution and then chloroplatinic acid was added to the solution. The solution was dried at $100^{\circ}C$ for 15hrs to remove the solvent and water then it was calcined at $500^{\circ}C$. The catalyst was activated with a gas mixture. During the activation, the temperature was increased from $150^{\circ}C$ to $500^{\circ}C$. The necessary amount of urea was dissolved in 50mL water and injected. Aqueous urea solution was then mixed with the feed gas stream. At low temperatures, nitrogen containing compounds of urea decomposition are used as reductants in the reducton of $NO_X$. However at high temperatures the nitrogen containing compounds are oxidized to NO and $NO_2$ by oxygen instead of being used in the reduction. The activity of the catalyst was dependent on urea concentration in the feed stream when there was not adequate water vapor in the feed. The maximum conversion was shifted from $250^{\circ}C$ to $150^{\circ}C$ when water concentration was increased from 2 to 17%. It seems that the maximum temperature shifts to lower temperatures because the hydrolysis rate of HNCO increases with water, resulting in higher amounts of $NH_3$.

Adsorption Characteristics by Synthesized Goethite in the Mixed Solution Systems of Phosphate, Sulfate, and Copper Ions (합성 Goethite에 의한 인산이온, 황산이온 및 구리이온의 혼합용액에서의 흡착특성)

  • 감상규;이동환;이민규
    • Journal of Environmental Science International
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    • v.12 no.10
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    • pp.1055-1060
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    • 2003
  • Adsorption on goethite of individual component from a solution containing phosphate, sulfate, or copper ion was investigated. Competitive adsorption in the binary and ternary solution systems composed of phosphate, sulfate, and copper ions was also investigated. In competitive adsorption systems with phosphate and sulfate ions, the presence of phosphate ion reduced the adsorption of sulfate ion largely. On the other hand, the presence of sulfate ion caused only a small decrease in phosphate adsorption. This result suggests that phosphate ion is a stronger competitor for adsorption on goethite than sulfate ion, which is consistent with the higher affinity of phosphate for the surface compared to sulfate ion. Compared to the results from single-sorbate systems, adsorption of copper ion in the binary system of sulfate ion and copper ion was found to be enhanced in the presence of sulfate ion. Addition of sulfate ion to the binary system of copper ion and phosphate ion resulted in a small enhancement in copper sorption. This result implies that the presence of sulfate ion promotes adsorption of the ternary complex FeOHCuSO$_4$. The adsorption isotherms could be well described by the Langmuir adsorption equation.

New Mathematical Model and Parallel Hybrid Genetic Algorithm for the Optimal Assignment of Strike packages to Targets (공격편대군-표적 최적 할당을 위한 수리모형 및 병렬 하이브리드 유전자 알고리즘)

  • Kim, Heungseob;Cho, Yongnam
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.4
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    • pp.566-578
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    • 2017
  • For optimizing the operation plan when strike packages attack multiple targets, this article suggests a new mathematical model and a parallel hybrid genetic algorithm (PHGA) as a solution methodology. In the model, a package can assault multiple targets on a sortie and permitted the use of mixed munitions for a target. Furthermore, because the survival probability of a package depends on a flight route, it is formulated as a mixed integer programming which is synthesized the models for vehicle routing and weapon-target assignment. The hybrid strategy of the solution method (PHGA) is also implemented by the separation of functions of a GA and an exact solution method using ILOG CPLEX. The GA searches the flight routes of packages, and CPLEX assigns the munitions of a package to the targets on its way. The parallelism enhances the likelihood seeking the optimal solution via the collaboration among the HGAs.

The effect of high-temperature on foamed concrete

  • Canbaz, Mehmet;Dakman, Hafid;Arslan, Baris;Buyuksungur, Arda
    • Computers and Concrete
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    • v.24 no.1
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    • pp.1-6
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    • 2019
  • Within the scope of this study, the foam solution was prepared by properly mixing sulfonate based foam agent with water. Furthermore, this solution was mixed with the mixture of fine sand, cement, and water to produce foamed concrete. The mixture ratios which are the percentage of foam solution used in foam concrete were chosen as 0, 20, 40 and 60% by vol. After these groups reached 28 days of strength, they were heated to 20, 100, 400 and $700^{\circ}C$ respectively. Afterward, high-temperature effects on the foamed concrete were obtained by employing physical and mechanical properties tests. Additionally, SEM (scanning electron microscope) and EDX (energy-dispersive X-ray spectroscopy) tests were employed to analyze the microstructure, and ${\mu}-CT$ (micro computed tomography) images were used to reconstruct 3-D models of the heat-treated specimens. Then, these models are analyzed to examine the void structures and the changes in these structures due to the high temperatures. The study has shown that the void structures reduce the high-temperature effects and the foam solution could be mixed with concrete up to 40 % by vol. where the high strength of foamed concrete is non-mandatory.