• Korean Journal of Soil Science and Fertilizer
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• v.50 no.6
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• pp.574-587
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• 2017

Excessive application of nitrogen (N) fertilizer to support switchgrass growth for bioenergy production may cause adverse environmental effects. The objective of this study was to determine optimum N application rate to increase biomass yield of switchgrass and to reduce adverse environmental effects related to N. Switchgrass was planted in May 2008 and biomass yield, N uses of switchgrass, nitrate ($NO_3$) leaching, and nitrous oxide ($N_2O$) emission were evaluated from 2010 through 2011. Total N removal significantly increased with N rate despite the fact that yield did not increased with above $56kg\;N\;ha^{-1}$ of N rate. Apparent nitrogen recoveries were 4.81 and 5.48% at 56 and $112kg\;N\;ha^{-1}$ of N rate, respectively. Nitrogen use efficiency decreased into half with increasing N rate from 56 to $112kg\;N\;ha^{-1}$. Nitrate leaching and $N_2O$ emission were related to N use of switchgrass. There was no significant difference of cumulative $NO_3$ leaching between 0 and $56kg\;N\;ha^{-1}$ but, it significantly increased at $112kg\;N\;ha^{-1}$. There was no significant difference of cumulative $N_2O$ emission among N rates in crest, but it significantly increased at $112kg\;N\;ha^{-1}$ in toe. Excessive N application rate (above $56kg\;N\;ha^{-1}$) beyond plant requirement could accelerate $NO_3$ leaching and $N_2O$ emission in switchgrass field. Overall, $56kg\;N\;ha^{-1}$ might be optimum N application rate in reducing economic waste on N fertilizer and adverse environmental impacts.

• Journal of Veterinary Clinics
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• v.31 no.4
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• pp.293-297
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• 2014

Swine influenza is an acute respiratory disease prevalent in pig-growing areas worldwide. In total, 518 gilt and sow serum samples and 14 litters (66 samples) of aborted fetuses from 37 farms (average of 14 serum samples per farm) in Gyeongbuk Province were collected between September 2010 and May 2011. All samples were examined for antibodies to swine influenza virus (SIV) H1N1 and H3N2 using enzyme-linked immunosorbent assay (ELISA). The seropositive rates of gilt and sows were 59.8% (310/518) for SIV H1N1, 78.8% (408/518) for H3N2, and 55.6% (288/518) for both subtypes tested. The rate of aborted fetuses was 13.6% (9/66) for H1N1, 9.1% (6/66) for H3N2, and 9.1% for both subtypes. The seroprevalence for H1N1 in gilts and sows was 46.6% (69/148) and 65.1% (241/370), respectively, and that for H3N2 was 78.4% (116/148) and 78.9% (292/370), respectively.

• Bulletin of the Korean Chemical Society
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• v.30 no.6
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• pp.1293-1296
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• 2009

A new series of N-substituted 2-n-butyl-3-fluoropyrroles were prepared by a simple one-pot reaction designed of retrosynthesis. $\alpha,\alpha-Difluoro-\gamma-iodo-\gamma$-(trimethylsilyl)propyl n-butyl ketone, a component precursor molecule to 2-n-butyl-3-fluoropyrroles, was prepared with Cu(0) catalyst. It reacted with various primary amines to yield N-substituted 2-n-butyl-3-fluoropyrroles. The products were synthesized via a one-pot reaction scheme between $\alpha,\alpha-Difluoro-\gamma-iodo-\gamma$-(trimethylsilyl) propyl n-butyl ketone and primary amines in excess ( $\geq$ 5 molar equivalence), which eliminate the need of KF required in obtaining n-butyl-1H-3-fluoropyrrole. The yield of products depended reversely on spatial bulkness around N-binding carbon.

• Journal of Korean Society on Water Environment
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• v.22 no.3
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• pp.482-491
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• 2006

The anaerobic ammonium oxidation (ANAMMOX) from substrates with various $NO_2-N$ and $NH_4-N$ concentationes, which were generated from piggery waste was accomplished by using anaerobic granular sludge as seeding sludge. As the result of operation, when $NO_2-N/NH_4-N$ ratios of ANAMMOX influent were 0.6~1.5, $NO_2-N/NH_4-N$ removal ratios were exhibited 1.19~2.07 (average 1.63). The higher influent $NO_2-N/NH_4-N$ ratios resulted in higher $NO_2-N/NH_4-N$ removal ratios by ANAMMOX. It means that $NO_2-N$ concentration is very important factor in ANAMMOX. Specific ammonium removal rate was constantly as $0.03{\sim}0.04gNH_4-N/g$ VSS-day at $35^{\circ}C$ while it was $0.01gNH_4-N/g$ VSS-day at $20{\sim}30^{\circ}C$. Thus, in order to reduce the effluent N concentration, either an increase of ANAMMOX reactor HRT or more biomass accumulation at the optimal temperature can be considered.

• Honam Mathematical Journal
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• v.41 no.1
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• pp.67-87
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• 2019

The main aim of this study is to characterize new classes of multicone graphs which are determined by their adjacency spectra, their Laplacian spectra, their complement with respect to signless Laplacian spectra and their complement with respect to their adjacency spectra. A multicone graph is defined to be the join of a clique and a regular graph. If n is a positive integer, a friendship graph $F_n$ consists of n edge-disjoint triangles that all of them meet in one vertex. It is proved that any connected graph cospectral to a multicone graph $F_n{\nabla}F_n=K_2{\nabla}nK_2{\nabla}nK_2$ is determined by its adjacency spectra as well as its Laplacian spectra. In addition, we show that if $n{\neq}2$, the complement of these graphs are determined by their adjacency spectra. At the end of the paper, it is proved that multicone graphs $F_n{\nabla}F_n=K_2{\nabla}nK_2{\nabla}nK_2$ are determined by their signless Laplacian spectra and also we prove that any graph cospectral to one of multicone graphs $F_n{\nabla}F_n$ is perfect.

• Toxicological Research
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• v.14 no.2
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• pp.177-181
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• 1998

Dithiocarbamate and mixed disulfide containing allyl functions were designed and synthesized as putative chemopreventive agents, i.e. N,N-diallyldithiocarbamate (DATC) and S-(N,N-diallyldithiocarbamoyl)-N-acetylcysteine (AC-DATC). DATC and AC-DATC were administered and the activities of cytosolic glutathione S-transferase (GST), glutathione reductase (GR) and microsomal N-nitrosodiethylamine (NDEA) deethylase were assayed in order to test the effects of these organosulfur com-pounds on the detoxification and metabolic activation system of NDEA. The amounts of hepatic glutathione (GSH and GSSG) was also determined. The administration of DATC to rats led to an increase in the activity of GR and to an inhibition of CYP2E1-mediated NDEA deethylation. AC-DATC induced the activity of GR and GST, increased the hepatic GSH content and inhibited the rate of NDEA deethylation. The level of GSSG was decreased as a consequence of the increased activity of GR. These effects may contribute to possible antimutagenic and anticarcinogenic action of the dithiocarbamates investigated.

• Honam Mathematical Journal
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• v.34 no.4
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• pp.519-531
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• 2012

Let ${\sigma}_s(N)={\sum}_{d{\mid}N}d^s$. Next, the convolution sums ${\sum}_{k<N/3}{\sigma}_1(3^mk){\sigma}_1(2^n(N-3k))$, ${\sum}_{<N/3}{\sigma}_1(2^mk){\sigma}_1(3^n(N-3k))$, etc., are evaluated for all $N{\in}\mathbb{N}$ with $m$, $n{\in}\mathbb{N}{\cup}\{0\}$.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.6C
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• pp.751-762
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• 2004

In this paper, we propose the method to derive new GRM(Generalized Reed-Muller) coefficients for each 2$^n$ polarities using Triangle cell. As the existing methods to generate GRM coefficients, there are Green's method to operate transform matrix with a given RM coefficient and Besslich's method to get other polarities using basic transfer matrices repeatedly. In this paper, Triangle cell is defined so as to obtain GRM coefficients efficiently. After arranging 2$^n$ given RM coefficients of a first row of Triangle cell, sequence modulo sum is peformed in parallel to low column by a fixed numerical formula. To prove the efficiency of proposed arithmetic method, it is compared with Besslich’s method. As the compared result, to calculate GRM coefficients of all polarities to n input variables, Besslich’s method needs 2$^n$$^{-1}$ ${\times}$(2$^n$-1) two-input Ex-ORs and the proposed method needs 2${\times}$(the number of Ex-ORs for n-1 variables)+3$^n$$^{-1}$ for the same system complexity - (lo $g_2$$^n$) $T_{X}$./.

• Journal of the Korean Institute of Telematics and Electronics
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• v.19 no.6
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• pp.52-54
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• 1982

p·Si-전해질 접합을 전해질로 6N H2SO4, 6N H2SO4(Ti3+), 6N H2SO4(Ti4+), 6N H2SO4(Ti4+/Ti3+)을 사용하여 만들었다. 이들 전해질중 6N H2SO4(Ti4-/Ti3+)을 사용할 때 p·Si 광음극이 안정하게 동학하며 높은 광전 감도를 가지고 있었다. p·Si-electrolyte junction are prepared by using p·Si photocatode in four different electrolytes such as 6N H2SO4, 6N H2SO4(Ti3+), 6N H2SO4(Ti4+), 6N H2SO4(Ti4+/Ti3+) respectively. Among those electrolytes 6N H2SO4(Ti4-/Ti3+) shows very good results, in which p·Si photocathode is stable.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.2
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• pp.315-318
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• 2016

In this paper, we present a new preimage attack on MJH, a double-block-length block cipher-based hash function. Currently, the best attack requires $O(2^{3n/2})$ queries for the 2n-bit MJH hash function based on an n-bit block cipher, while our attack requires $O(n2^n)$ queries and the same amount of memory, significantly improving the query complexity compared to the existing attack.