• Korean Journal of Soil Science and Fertilizer
• /
• v.24 no.3
• /
• pp.171-176
• /
• 1991

Field experiment was conducted to investigate the seasonal change in inorganic nitrogen content in grassland soil profile after urea application. Urea was applied at the levels of 0 (0N), 14 (14N), and 28 (28N) Kg N per 10a. Soil samples were taken at every 20 cm interval upto 100 cm soil depth in spring (May 26), summer (July 27), and autumn (October 18) and analysed for total and inorganic nitrogen ($NH_4-N$ and $NO_3-N$). The results obtained are as follows ; 1. In spring, the $NH_4-N$ content of ON treatment was higher than $NO_3-N$ content both in surface and subsoil. The urea application increasing both $NH_4-N$ and $NO_3-N$ contents in the surface soils and these contents decreased with soil depth. 2. In summer, increase in urea application rate elevated the $NO_3-N$ content in soil profile of 0 to 100cm and the content reached upto 42 ppm in the 28N treatment. 3. The seasonal difference in $NH_4-N$ content between summer and autumn was insignificant throughout soil profile. Soil $NO_3-N$ content in autumn were 7 and 14 ppm for 14N and 28N respectively, showing very low values compared with that of summer. 4. The ratio of inorganic nitrogen to total nitrogen increased with soil depth and with urea application rates.

• Journal of the Korean Applied Science and Technology
• /
• v.35 no.3
• /
• pp.643-653
• /
• 2018

This study was investigated the mechanism of action of n-6/n-3 fatty acid ratio on the metabolic partitioning of blood glycerolipids by in vivo monitoring technique in hyperlipidemic animal model rats. The ratio of cholesteryl 14C-oleate metabolized in the liver of total glycerolipids was lower in the order of n-6/n-3 ratios of 4:1, 15:1, 30:1 and control group (p<0.05). The secretion amount of phospholipid was higher in the order of n-6/n-3 ratio 4:1, 15:1, 30:1 than the control (p<0.05). The secretion amount of triglyceride was lower in especially 4:1, in order of n-6/n-3 4:1, 15:1 and 30:1 compared with the control. The ratio of phospholipid partitioning to total glycerolipid was high in orfer of n-6/n-3 ratio 4:1, 15:1, 30:1 and control (p<0.05). The triacylglycerol partitioning (%) via liver was higher 72.97, 75.93, 78.12% in n-6/n-3 4;1, 15:1, 30:1, respectively than the control of 82.25%, according to increased n-6/n-3 (p<0.05). The phospholipid partitioning (%) was lower 25.15, 18.87, 18.15% in n-6/n-3 4;1, 15:1, 30:1, respectively, compared to control 11.04%, according to increased n-6/n-3 (p<0.05).

• Journal of the Korean Chemical Society
• /
• v.20 no.1
• /
• pp.73-86
• /
• 1976

Four unreported derivatives of N-arylsulfonylbenzamide and six derivatives of N-arylsulfonylbenzimidothiophenyl ester were prepared. These were; p-methyl-N-(arylsulfonyl)benzamide, m-methyl-N-(arylsulfonyl)benzamide, m-nitro-N-(arylsulfonyl)benzamide, p-methoxy-N-(arylsulfonyl)benzamide, p-methyl-N-(arylsulfonyl)benzimidothiophenyl esters, p-chloro-N-(arylsulfonyl)benzimidothiophenyl ester, m-methyl-N-(arylsulfonyl)benzimidothiophenyl ester, p-nitro-N-(arylsulfonyl)benzimidothiophenyl ester, m-nitro-(arylsulfonyl)benzimidothiophenyl ester and p-methoxy-N-(arylsulfonyl)benzimidothiophenyl ester. The rate constants of the hydrolysis of N-arylsulfonylbenzimidothiophenyl esters were determined by ultraviolet spectrophotometry at various pH and rate equations which can be applied over a wide pH range were obtained. From the rate equation and substituent effects, one can conclude that above pH 11, the hydrolysis of N-arylsulfonylbenzimidothiophenyl esters are initiated by the attack of hydroxide ion, however, below pH 9, started by the addition of a water molecule on the azomethine group. At pH 9∼11, the competitive reaction between a water molecule and hydroxide ion is anticipated to occur.

• Journal of the Korean Magnetics Society
• /
• v.22 no.5
• /
• pp.157-161
• /
• 2012

Magnetism at the interfaces of rocksalt structured half-metals, NaN and CaN were investigated by use of the first-principles band calculations. The electronic structures for the simple interface and mixed interface systems were calculated by the FLAPW (full-potential linearized augmented plane wave) method. From the calculated number of electrons in muffin-tin spheres of each atom, we found, for the simple interface system, that the magnetic moment of the N atom in the CaN (NaN) side is increased (decreased) compared to those of inner N atoms. For the mixed interface system, the magnetic moments of the interface N atoms are similar to the averaged value for the inner N atoms in CaN and NaN side. Among four interface N atoms, the N atom connected to Na atoms in the upper and down layers has the largest magnetic moment and that connected to Ca atoms has the smallest. The number of p electrons in each N atom and the calculated density of states explain well the above situation.

• Honam Mathematical Journal
• /
• v.44 no.1
• /
• pp.135-145
• /
• 2022

This paper aims to investigate characterizations on parameters k₁, k₂, k₃, k₄, k₅, l₁, l₂, l₃, and l₄ to find relation between the class of 𝓗(k, l, m, n, o) hypergeometric functions defined by $$5_F_4\[{\array{k_1,\;k_2,\;k_3,\;k_4,\;k_5\\l_1,\;l_2,\;l_3,\;l_4}}\;:\;z\]=\sum\limits_{n=2}^{\infty}\frac{(k_1)_n(k_2)_n(k_3)_n(k_4)_n(k_5)_n}{(l_1)_n(l_2)_n(l_3)_n(l_4)_n(1)_n}z^n$$. We need to find k, l, m and n that lead to the necessary and sufficient condition for the function zF([W]), G = z(2 - F([W])) and $H_1[W]=z^2{\frac{d}{dz}}(ln(z)-h(z))$ to be in 𝓢^*(2^-r), r is a positive integer in the open unit disc 𝒟 = {z : |z| < 1, z ∈ ℂ} with $$h(z)=\sum\limits_{n=0}^{\infty}\frac{(k)_n(l)_n(m)_n(n)_n(1+\frac{k}{2})_n}{(\frac{k}{2})_n(1+k-l)_n(1+k-m)_n(1+k-n)_nn(1)_n}z^n$$ and $$[W]=\[{\array{k,\;1+{\frac{k}{2}},\;l,\;m,\;n\\{\frac{k}{2}},\;1+k-l,\;1+k-m,\;1+k-n}}\;:\;z\]$$.

• Journal of Bio-Environment Control
• /
• v.5 no.2
• /
• pp.120-130
• /
• 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.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.4
• /
• pp.466-475
• /
• 2005

Docosahexaenoic acid (22:6n-3, DHA) is highly enriched in membrane of brain and retina, and plays an important role in maintaining an optimal function of the central nervous system. We investigated the effect of n-3 fatty acid deficiency on rat brain, retina and liver fatty acyl composition at two different ages (3 wks and 15 wks) under DHA deficient condition. Rat pups born to dams fed a diet with $3.1\%$ of total fatty acids as $\alpha-linolenic$ acid (LNA) were fed using an artificial rearing system either an n-3 deficient (n-3 Def) or n-3 adequate (n-3 Adq) diet. Both diets contained $17.1\%$ linoleic acid (LA) but the n-3 Adq diet also contained $3.1\%$ LNA. Rats consuming the n-3 Def diet showed a lower brain $(50\%\;in\;13\;wks\;and\;70\%\;in\;15\;wks,\;p<0.05)$ and retinal $(50\%\;in\;13\;wks\;and\;63\%\;in\;15\;wks,\;p<0.05)$ DHA than those on the n-3 Adq diet, which was largely compensated for by an increase in docosapentaenoic acid (22:5n-6, DPAn-6). In the liver of the n-3 Def group, the percentage of DHA decreased by $97\%$ at 3 wks of age with an apparent increase in DPAn-6 relative to the n-3 Adq group (p<0.05), while there was a $65\%$ lower liver DHA in n-3 Def group at 15 wks of age than the n-3 Adq group (p<0.05). Liver arachidonic acid (20:4n-6, AA) was increased at 3 wks of age but decreased at 15 wks of age in the n-3 Def group compared with n-3 Adq group (p<0.05). In conclusion, the replacement of DHA by DPAn-6 in brain and retina fatty acid composition may be related to the suboptimal function in spatial learning, memory and visual acuity. This artificial rearing method presents a first generation model for n-3 deficiency that is similar to the case of human nutrition that commonly employed two generation model.

• Bulletin of the Korean Mathematical Society
• /
• v.36 no.4
• /
• pp.799-808
• /
• 1999

We investigate when the .product of two smooth manifolds admits a weakly Lagrangian embedding. Assume M, N are oriented smooth manifolds of dimension m and n,. respectively, which admit weakly Lagrangian immersions into $C^m$ and $C^n$. If m and n are odd, then $M\;{\times}\;N$ admits a weakly Lagrangian embedding into $C^{m+n}$ In the case when m is odd and n is even, we assume further that $\chi$(N) is an even integer. Then $M\;{\times}\;N$ admits a weakly Lagrangian embedding into $C^{m+n}$. As a corollary, we obtain the result that $S^n_1\;{\times}\;S^n_2\;{\times}\;...{\times}\;S^n_k$, $\kappa$>1, admits a weakly Lagrang.ian embedding into $C^n_1+^n_2+...+^n_k$ if and only if some ni is odd.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2003.03a
• /
• pp.105-105
• /
• 2003

InGaN/GaN MQW 구조는 청색 및 녹색 범위의 밴드 갭을 가지는 반도체로 최근 LED 및 LD 제조 등에 이용되고 있다. InGaN/GaN MQW은 InGaN와 GaN의 최적 성장온도의 중간온도에서 실행된다. InGaN와 GaN는 최적 성장온도의 차이가 크므로 중간온도에서 성장 시에 많은 결함이 생긴다. 성장온도가 높으면 InN가 분해되고 낮을 경우에는 질소의 결핍이 일어난다. 최적성장온도의 선택이 매우 중요한 문제로 주목되었다. Si 도핑으로 중간온도 성장 시에 형성되는 결함을 감소시키고 광학적 특성을 향상시킨다고 보고되었다. 그러나, Si 도핑효과에 대한 구체적이고 체계적인 연구는 부족한 실정이다. MQWs 구조의 GaN 장벽층에 미치는 성장온도와 Si 도핑 효과를 이해하기 위해서는 고온에서 성잠시킨 GaN박막(HT-GaN) 위에 중간온도에서 성장된 GaN 에피층(IT-GaN)의 구조에 관한 연구가 선행되어야한다. 본 연구에서는 HT-GaN 위에 성장된 GaN 에피층에 미치는 성장 온도와 Si 도핑 효과에 관해 연구하였다.

• BMB Reports
• /
• v.34 no.3
• /
• pp.225-229
• /
• 2001

Besides a variety of quinones, purified bovine liver quinone reductase catalyzed the reduction of N,N-p-nitrosoaniline to N,N-dimethyl-p-phenylenediamine. The formation of N,N-dimethyl-p-phenylenediamine was identified by TLC, GC, GC-MS and NMR. Quinone reductase can utilize either NADH or NADPH as a source of reducing equivalents. The apparent Km for 1,4-benzoquinone and N,N-dimethyl-p-nitrosoaniline was 1.64 mM and 0.22 mM, respectively The reduction of N,N-dimethyl-p-nitrosoaniline was almost entirely hampered by dicumarol or Cibacron blue 3GA, potent inhibitors of mammalian quinone reductase. During the bovine liver quinone reductase-catalyzed reduction of N,N-dimethyl-p-nitrosoaniline, benzoquinonediiminium ion was produced.