• Title/Summary/Keyword: $N_2$

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Effects of $\textrm{NO}_3$-N:$\textrm{NH}_4$-N Ratio and Elevated $\textrm{CO}_2$ on Growth and Quality of Lactuca sativa L. in Nutrient Film Technique (NFT재배에서 $\textrm{CO}_2$ 시용과 배양액의 $\textrm{NO}_3$:$\textrm{NH}_4$비율이 결구상추의 생육 및 품질에 미치는 영향)

  • 원선이;조영렬;이용범
    • Journal of Bio-Environment Control
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    • v.5 no.2
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    • pp.120-130
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    • 1996
  • Crisphead lettuce(Lactuca sativa L.) was grown in NFT to investigate the effects of NO$_3$-N and NH$_4$-N ratio in nutrient solution and elevated $CO_2$ treatment in the crisphead lettuce growth. This experiment has been conducted under three different ratios of NO$_3$-N:NH$_4$-N(100:0, 75:25, 50:50) with two $CO_2$ concentration (control, 1500ppm ). The results are as follows; 1. In the case of not controlling pH and EC in nutrient solution, pH was gradually increased in NO$_3$-N:NH$_4$-N=100:0 treatment but rapidly decreased in the nutrient solution 2. Daily changes of NO$_3$-N and NH$_4$-N were observed without controlling the nutrient solution. In the treatments of NO$_3$-N:NH$_4$-N ratios were 75:25 and 50:50, NO$_3$-N absorption rates were 27.7% and 26.1%, while NH$_4$-N absorption rates were 87.9% and 71.2%, respectively. 3. There was little differences in total nitrogen of leaves. However phosphorus, potassium, calcium and magnesium contents were highly shown in the treatment of $CO_2$ 1500ppm and 100:0 ratio of NO$_3$-N:NH$_4$-N. 4. Higher $CO_2$ assimilation rate was shown in plants grown under $CO_2$ 1500ppm and 100:0 ratio of NO$_3$-N:NH$_4$-N. It dropped significantly with the increase of NH$_4$- N rates in nutrient solution. 5. Fresh weight, leaf number, root length and root weight of crisphead lettuce were far better in the treatment of $CO_2$ 1500ppm and 100:0 ratio of NO$_3$-N:NH$_4$-N. Growth differences by $CO_2$ elevation were not shown in other NO$_3$-N:NH$_4$-N treatments. 6. The highest nitrate contents of leaves were shown in NO$_3$-N single treatment but shown the lowest vitamin C contents. Nitrate contents of leaves were decreased by $CO_2$ but the effect was slight treatment.

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Embedding Algorithms among $2^{2n-k}\times2^k$ Torus and HFN(n,n) ($2^{2n-k}\times2^k$ 토러스와 HFN(n,n)의 상호 임베딩)

  • Kang, Min-Sik;Kim, Jong-Seok;Lee, Hyeong-Ok;Heo, Yeong-Nam
    • Proceedings of the Korea Information Processing Society Conference
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    • 2002.11a
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    • pp.111-114
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    • 2002
  • 임베딩은 어떤 연결망이 다른 연결망 구조에 포함 혹은 어떻게 연관되어 있는지를 알아보기 위해 어떤 특정한 연결망을 다른 연결망에 사상하는 것으로, 특정한 연결망에서 사용하던 여러 가지 알고리즘을 다른 연결망에서 효율적으로 이용할 수 있도록 한다. 본 논문에서는 $2^{2n-k}\times2^k$ 토러스를 HFN(n,n)에 연장율 3, 밀집율 4 로 임베딩 가능함을 보이고, HFN(n,n)을 $2^{2n-k}\times2^k$ 토러스에 연장율 O(N)으로 임베딩됨을 보인다($N=2^n$).

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Cylization Reaction of 2 (2', 2'-diethoxy ethyl) Aminobenzamide derivatives (II) (2(2',2'-디에톡시 에틸)아미노벤즈아미드 유도체의 고리화반응(II))

  • Yoo, Hee-Weon;Lee, Jin-Wha;Suh, Myung-Eun
    • YAKHAK HOEJI
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    • v.33 no.4
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    • pp.246-252
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    • 1989
  • 2-Amino-1-N-methyl benzamide, 2-N-benzyl amino benzamide, 2-N-phenyl amino benzamide of 2-amino benzamide derivatives were reacted with ${\alpha}-bromo$ acetaldehyde diethyl acetal in basic condition. 2-N-alkylated products were prepared from 2-amino-1-N-methyl benzamide and 2-N-phenyl amino benzamide. 1-N-benzyl-1.4-benzodiazepin-5-one was prerpared from 2-N-benzyl aminobenzamide via intramolecular cyclization. However, 2-amino-1-N-methyl benzamide with sodium amide did not react to 1.4-benzodiazepin-5-one derivative but 3-methyl-quinazoline-2.4-dione was obtained.

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WEAK AND STRONG CONVERGENCE TO COMMON FIXED POINTS OF NON-SELF NONEXPANSIVE MAPPINGS

  • Su, Yongfu;Qin, Xiaolong
    • Journal of applied mathematics & informatics
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    • v.24 no.1_2
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    • pp.437-448
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    • 2007
  • Suppose K is a nonempty closed convex nonexpansive retract of a real uniformly convex Banach space E with P as a nonexpansive retraction. Let $T_1,\;T_2\;and\;T_3\;:\;K{\rightarrow}E$ be nonexpansive mappings with nonempty common fixed points set. Let $\{\alpha_n\},\;\{\beta_n\},\;\{\gamma_n\},\;\{\alpha'_n\},\;\{\beta'_n\},\;\{\gamma'_n\},\;\{\alpha'_n\},\;\{\beta'_n\}\;and\;\{\gamma'_n\}$ be real sequences in [0, 1] such that ${\alpha}_n+{\beta}_n+{\gamma}_n={\alpha}'_n+{\beta'_n+\gamma}'_n={\alpha}'_n+{\beta}'_n+{\gamma}'_n=1$, starting from arbitrary $x_1{\in}K$, define the sequence $\{x_n\}$ by $$\{zn=P({\alpha}'_nT_1x_n+{\beta}'_nx_n+{\gamma}'_nw_n)\;yn=P({\alpha}'_nT_2z_n+{\beta}'_nx_n+{\gamma}'_nv_n)\;x_{n+1}=P({\alpha}_nT_3y_n+{\beta}_nx_n+{\gamma}_nu_n)$$ with the restrictions $\sum^\infty_{n=1}{\gamma}_n<\infty,\;\sum^\infty_{n=1}{\gamma}'_n<\infty,\; \sum^\infty_{n=1}{\gamma}'_n<\infty$. (i) If the dual $E^*$ of E has the Kadec-Klee property, then weak convergence of a $\{x_n\}$ to some $x^*{\in}F(T_1){\cap}{F}(T_2){\cap}(T_3)$ is proved; (ii) If $T_1,\;T_2\;and\;T_3$ satisfy condition(A'), then strong convergence of $\{x_n\}$ to some $x^*{\in}F(T_1){\cap}{F}(T_2){\cap}(T_3)$ is obtained.

Atmospheric CO2 enrichment reduces wheat nitrate utilization and enhances soil N2O emissions

  • Hu, Shuijin
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.4-4
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    • 2017
  • Atmospheric carbon dioxide enrichment ($eCO_2$) often increases soil nitrous oxide ($N_2O$) emissions, but the underlying mechanisms are not fully understood. Emerging evidence suggests that $eCO_2$ alters plant N preference in favor of ammonium ($NH_4{^+}-N$) over nitrate ($NO_3{^-}-N$). Yet, whether and how this attributes to the enhancement of $N_2O$ emissions has not been investigated. We examined the effects of $eCO_2$ on soil $N_2O$ emissions in the presence of two N forms ($NH_4{^+}-N$ or $NO_3{^-}-N$), using wheat (Triticum aestivum L.) as a model plant. Our results showed that N forms dominated $eCO_2$ effects on plant and microbial N utilization, and thus soil $N_2O$ emissions. Elevated $CO_2$ significantly increased the rate and the sum of $N_2O$ emissions by three to four folds when $NO_3{^-}-N$, but not $NH_4{^+}-N$, was supplied. Enhanced $N_2O$ emission was related to the reduced plant $NO_3{^-}-N$ uptake in wheat. We propose a new conceptual model in which $eCO_2$-inhibition of plant $NO_3{^-}-N$ uptake and/or $CO_2$-enhancement of soil labile C enhances the N and/or C availability for denitrifiers and increases the intensity and/or the duration of $N_2O$ emissions. Together, these findings suggest that to enhance plant N use efficiency and reduce $N_2O$ emission, crop breeding and management need to consider altered plant preference of N sources under future $CO_2$ scenarios.

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SOME NEW IDENTITIES CONCERNING THE HORADAM SEQUENCE AND ITS COMPANION SEQUENCE

  • Keskin, Refik;Siar, Zafer
    • Communications of the Korean Mathematical Society
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    • v.34 no.1
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    • pp.1-16
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    • 2019
  • Let a, b, P, and Q be real numbers with $PQ{\neq}0$ and $(a,b){\neq}(0,0)$. The Horadam sequence $\{W_n\}$ is defined by $W_0=a$, $W_1=b$ and $W_n=PW_{n-1}+QW_{n-2}$ for $n{\geq}2$. Let the sequence $\{X_n\}$ be defined by $X_n=W_{n+1}+QW_{n-1}$. In this study, we obtain some new identities between the Horadam sequence $\{W_n\}$ and the sequence $\{X_n\}$. By the help of these identities, we show that Diophantine equations such as $$x^2-Pxy-y^2={\pm}(b^2-Pab-a^2)(P^2+4),\\x^2-Pxy+y^2=-(b^2-Pab+a^2)(P^2-4),\\x^2-(P^2+4)y^2={\pm}4(b^2-Pab-a^2),$$ and $$x^2-(P^2-4)y^2=4(b^2-Pab+a^2)$$ have infinitely many integer solutions x and y, where a, b, and P are integers. Lastly, we make an application of the sequences $\{W_n\}$ and $\{X_n\}$ to trigonometric functions and get some new angle addition formulas such as $${\sin}\;r{\theta}\;{\sin}(m+n+r){\theta}={\sin}(m+r){\theta}\;{\sin}(n+r){\theta}-{\sin}\;m{\theta}\;{\sin}\;n{\theta},\\{\cos}\;r{\theta}\;{\cos}(m+n+r){\theta}={\cos}(m+r){\theta}\;{\cos}(n+r){\theta}-{\sin}\;m{\theta}\;{\sin}\;n{\theta},$$ and $${\cos}\;r{\theta}\;{\sin}(m+n){\theta}={\cos}(n+r){\theta}\;{\sin}\;m{\theta}+{\cos}(m-r){\theta}\;{\sin}\;n{\theta}$$.

Theoretical Study of the Structures and Binding Energies of Ca+-(CO)n and Ca+-(CO2)n (n=1,2) (Ca+-(CO)n과 Ca+-(CO2)n (n=1,2)의 구조와 결합에너지에 대한 이론 연구)

  • Park, Gil-Soon;Sung, Eun-Mo
    • Journal of the Korean Chemical Society
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    • v.53 no.3
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    • pp.272-278
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    • 2009
  • The optimized structures and vibrational frequencies for $Ca^+-(CO)_n$ and $Ca^+-(CO_2)_n$ (n=1,2) complexes were calculated with MP2 and B3LYP methods employing 6-311++G(2d,p) basis sets. Also the binding energies were investigated for all complexes to compare the stabilities. For $Ca^+-(CO)_n$ C-bonded complexes are more stable than O-bonded complexes. Two stable conformations, linear and $C_{2v}$ form, are possible for $Ca^+-(CO)_2$ complexes and the $C_{2v}$ form is more stable than the linear form. $Ca^+-(CO_2)_2$ also has two possible conformations and linear form has slightly lower energy than $C_{2v}$ form.

MINIMAL QUADRATIC RESIDUE CYCLIC CODES OF LENGTH $2^{n}$

  • BATRA SUDHIR;ARORA S. K.
    • Journal of applied mathematics & informatics
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    • v.18 no.1_2
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    • pp.25-43
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    • 2005
  • Let F be a finite field of prime power order q(odd) and the multiplicative order of q modulo $2^{n}\;(n>1)\;be\; {\phi}(2^{n})/2$. If n > 3, then q is odd number(prime or prime power) of the form $8m{\pm}3$. If q = 8m - 3, then the ring $R_{2^n} = F[x]/ < x^{2^n}-1 >$ has 2n primitive idempotents. The explicit expressions for these primitive idempotents are obtained and the minimal QR cyclic codes of length $2^{n}$ generated by these idempotents are completely described. If q = 8m + 3 then the expressions for the 2n - 1 primitive idempotents of $R_{2^n}$ are obtained. The generating polynomials and the upper bounds of the minimum distance of minimal QR cyclic codes generated by these 2n-1 idempotents are also obtained. The case n = 2,3 is dealt separately.

On Comaximal Graphs of Near-rings

Development of Selective GaN etching Process for p-GaN/AlGaN/GaN E-mode FET Fabrication (p-GaN/AlGaN/GaN E-mode FET 제작을 위한 선택적 GaN 식각 공정 개발)

  • Jang, Won-Ho;Cha, Ho-Young
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.24 no.2
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    • pp.321-324
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    • 2020
  • In this work, we developed a selective etching process for GaN that is a key process in p-GaN/AlGaN/GaN enhancement-mode (E-mode) power switching field-effect transistor (FET) fabrication. In order to achieve a high current density of p-GaN/AlGaN/GaN E-mode FET, the p-GaN layer beside the gate region must be selectively etched whereas the underneath AlGaN layer should be maintained. A selective etching process was implemented by oxidizing the surface of the AlGaN layer and the GaN layer by adding O2 gas to Cl2/N2 gas which is generally used for GaN etching. A selective etching process was optimized using Cl2/N2/O2 gas mixture and a high selectivity of 53:1 (= GaN/AlGaN) was achieved.