A study of nerve agent model organophosphonate binding with manganese-A₂B-corrole and -A₂B₂-porphyrin systems

Kim, K.,Kim, I.,Maiti, N.,Kwon, S.J.,Bucella, D.,Egorova, O.A.,Lee, Y.S.,Kwak, J.,Churchill, D.G. Pergamon Press 2009 Polyhedron Vol.28 No.12

Herein the synthesis and binding studies of novel trans-A<SUB>2</SUB>B-corrole and trans-A<SUB>2</SUB>B<SUB>2</SUB>-porphyrin derivatives are presented in comparing manganese(III)-organophosphonate (OP) binding (e.g., M<SUP>n+</SUP>←O?PR(OR)<SUB>2</SUB>) capabilities. H<SUB>3</SUB>(PFP-VC) [PFP-VC=5,15-di(pentafluorophenyl)-10-(3-vinylphenyl)corrolate] was synthesized by way of literature procedures and was characterized by a variety of 2-D NMR spectroscopic techniques and single-crystal X-ray diffraction. These compounds represent the first example of 3-vinyl-phenyl-containing meso-substituted corroles or porphyrins. Mn(PFP-VC) (3) was treated separately with (CH<SUB>3</SUB>CH<SUB>2</SUB>O)<SUB>2</SUB>P?O(C<SUB>3</SUB>H<SUB>6</SUB>NMe<SUB>2</SUB>), (C<SUB>4</SUB>H<SUB>9</SUB>O)<SUB>2</SUB>P?O(Me), (C<SUB>2</SUB>H<SUB>5</SUB>O)<SUB>2</SUB>P?O(CH<SUB>2</SUB>COCH<SUB>3</SUB>), (CH<SUB>3</SUB>CH<SUB>2</SUB>O)<SUB>2</SUB>P?O(Me), to give 1:1 adducts, as determined by UV-Vis spectroscopy (Job Plot), giving a red shift; Ph<SUB>3</SUB>P?O, was also found to bind, but very weakly. The trans-A<SUB>2</SUB>B<SUB>2</SUB>-porphyrin analogue Mn(PFP-VP) (4) was also prepared by way of a literature procedure; related binding studies gave 1:1 organophosphonate-Mn(PFP-VP) adducts (Job Plot). A clean blue shift occurred for the Mn-porphyrins at higher organophosphonate loadings (K<SUB>a</SUB> values: 6.7 (0.9)-11.9 (0.4)M<SUP>-1</SUP>). DFT geometry optimizations of O?P(OMe)<SUB>2</SUB>Me binding and formal Mn-O or P-O cleavage products in the unsubstituted neutral Mn-corrolato and -porphyrinato systems with a range of metal-based spin states revealed greatest stability in formal phosphoryl oxygen binding (energies: 11-13kcal/mol) for the Mn-corrole (singlet); the Mn-porphyrin (sextet) was also quite stable.

Excluded vertex-minors for graphs of linear rank-width at most k

Jeong, J.,Kwon, O.j.,Oum, S.i. Academic Press 2014 European journal of combinatorics : Journal europ& Vol.41 No.-

Linear rank-width is a graph width parameter, which is a variation of rank-width by restricting its tree to a caterpillar. As a corollary of known theorems, for each k, there is a finite obstruction set O<SUB>k</SUB> of graphs such that a graph G has linear rank-width at most k if and only if no vertex-minor of G is isomorphic to a graph in O<SUB>k</SUB>. However, no attempts have been made to bound the number of graphs in O<SUB>k</SUB> for k≥2. We show that for each k, there are at least 2<SUP>Ω(3^k)</SUP> pairwise locally non-equivalent graphs in O<SUB>k</SUB>, and therefore the number of graphs in O<SUB>k</SUB> is at least double exponential. To prove this theorem, it is necessary to characterize when two graphs in O<SUB>k</SUB> are locally equivalent. A graph is a block graph if all of its blocks are complete graphs. We prove that if two block graphs without simplicial vertices of degree at least 2 are locally equivalent, then they are isomorphic. This not only is useful for our theorem but also implies a theorem of Bouchet (1988) stating that if two trees are locally equivalent, then they are isomorphic.

Combustion properties of gaseous CH₄/O₂ coaxial jet flames in a single-element combustor

Kim, T.Y.,Choi, S.,Kim, H.K.,Jeung, I.S.,Koo, J.,Kwon, O.C. Butterworths [etc.] ; Elsevier Science Ltd 2016 Fuel Vol.184 No.-

Fundamental combustion properties of gaseous methane (CH<SUB>4</SUB>)/oxygen (O<SUB>2</SUB>) coaxial jet flames in a single-element combustor are experimentally evaluated as a preliminary step for subsequent studies of injection at very low temperature or using liquid O<SUB>2</SUB> for CH<SUB>4</SUB>/O<SUB>2</SUB> bipropellants, recently appearing to be the oncoming liquid bipropellant. A combustion chamber with quartz windows, a single shear coaxial injector and an exhaust nozzle on the downstream of the chamber is considered for the present study. Focusing on the measurements of the ignition and combustion stability limits of the coaxial jet flames in the chamber, flame visualization is also conducted by OH<SUP>*</SUP> chemiluminescence, schlieren imaging and direct imaging. Results show the ignition limits restricted than the combustion stability limits. Flame behaviors are largely classified into two, the stably attached flame and the oscillating, liftoff (near-blowout) flame. Due to cooling effects on the wall of the chamber, stably liftoff flame is not observed. The stability of the flame is greatest at fuel-rich condition (based on the injected amounts of CH<SUB>4</SUB> and O<SUB>2</SUB>). From the flame visualization flame thickness is found to be smaller than the injector lip thickness and insensitive to injection conditions. The laminar-flow behavior near the injector exit due to the strong burning of pure O<SUB>2</SUB> is observed even for high Reynolds numbers (Re). The flame visualization also exhibits the recirculating O<SUB>2</SUB> that enhances burning in the combustor through the reaction with the outer fuel jet. The results of ignition limits, combustion stability limits and flame visualization can be used as a database for researches of modeling the gaseous CH<SUB>4</SUB>/O<SUB>2</SUB> jet flames in the combustion chamber.

장기 저장연료의 열안정성 및 연료접촉 고무오링의 수명예측 연구

정근우(K. W. Chung),홍진숙(J. S. Hong),김영운(Y. W. Kim),한정식(J. S. Han),정병훈(B. H. Jeong),권태수(T. S. Kwon),서동욱(D. O. Suh),성민준(M. J. Sung),권영일(Y. I. Kwon) 한국트라이볼로지학회 2018 한국윤활학회지(윤활학회지) Vol.34 No.5

Thermal deterioration of fuel due to long-term storage influences engine performance and causes malfunctions. Fuel stability is usually evaluated via heat resistance and thermal stability during a brief heat shock at high temperature; storage stability in this scenario means that there is very little change in the quality of the fuel during long-term storage. In addition, rubber-based products such as oil seals, O-rings, and rubber hoses can influence the quality of the fuel. When these rubber products are in contact with fuel, they can swell, mechanically weaken, and occasionally crack, thus leaking low molar weight rubber and additives including plasticizer and antioxidant into the fuel to degrade its properties and shorten its useful lifetime. This study determines the thermal stabilities of three kinds of synthetic fuels by evaluating their low temperature kinematic viscosities, chemical composition changes via GC analyses, gross heat of combustion, and color changes. We evaluate the compression set of O-rings by immersing one NBR and two FKM rubber O-rings in the three synthetic fuel samples in airtight containers at variable storage temperatures for six months; from this, we estimate the lifetimes of the O-rings using the Power law model. There were very little changes in the chemical compositions and gross heat of combustion after six months of the experiment. The lifetimes are thus dependent on the materials of the rubber products, and in particular, the FKM O-ring was calculated to have a theoretical lifetime of 200 to 5,700 years. These results indicate that the synthetic fuels maintain their physical properties even after long-term storage at high temperatures, and the FKM O-ring is suitable for long-term sealing of these fuels.

Effects of CO₂ addition on flame extinction in interacting H₂-air and CO-air premixed flames

Jung, S.W.,Park, J.,Kwon, O.B.,Kim, Y.J.,Keel, S.I.,Yun, J.H.,Lim, I.G. Butterworths [etc.] ; Elsevier Science Ltd 2014 Fuel Vol.136 No.-

The effects of CO<SUB>2</SUB> addition on the downstream interactions of H<SUB>2</SUB>-air and CO-air premixed flames were investigated. Flame stability diagrams mapping the extinction limits for various fuel concentrations as functions of the strain rate were developed for the downstream interactions between H<SUB>2</SUB>-air and CO-air premixed flames with 0-20% CO<SUB>2</SUB> addition. Of particular concern was the impact of the chemical reactions of the additional CO<SUB>2</SUB> on the flame extinction characteristics. The results showed that CO<SUB>2</SUB> addition suppressed the flammable regions appreciably and decreased the critical strain rate, opening up the lean extinction boundary. For highly stretched interacting flames, two flammable island regions on the maps were combined into one when 10% or 20% CO<SUB>2</SUB> was added to either the H<SUB>2</SUB>-air or CO-air premixed mixtures. The chemical reactions of the additional CO<SUB>2</SUB> were significant, especially for high strain rate flames, while the effect of the radiative heat loss of the additional CO<SUB>2</SUB> was minor, even for low strain rate flames. Such chemical reactions were determined by competition between the reaction steps for the consumption and production of HCO and the reverse reaction of CO+OH=CO<SUB>2</SUB>+H with the reaction step of H+O<SUB>2</SUB>→O+OH, an indicator of the overall reaction rate for the H atoms. This resulted in a weakened interacting flame. Such chemical reactions of the additional CO<SUB>2</SUB> were examined in detail to describe the flame characteristics.

자돈 및 육성돈에 있어 α-1,6-galactosidase와 β-1,4-mannanase의 사료내 첨가가 성장 및 영양소 소화율에 미치는 영향

권오석,김인호,이상환,홍종욱,김지훈,문태현,이지훈 한국동물자원과학회 2003 한국축산학회지 Vol.45 No.2

본 연구는 양돈사료내 대두박 항영양인자인 α-galactosides와 galatomannan의 분해를 유도하는 α-1,6-galactosidase와 β-1,4-mannanase의 사료 내 첨가가 자돈 및 육성돈의 성장과 영양소 소화율에 미치는 영향을 조사하기 위하여 실시하였다. 시험 1은 개시시 체중 10.57±0.30㎏의 3원 교잡종 자돈 60두를 공시하였으며, 시험설계는 옥수수-건조유청-대두박 위주의 사료에 NRC (1998)의 영양소 요구량에 따라 처리한 대조구 (CON), 대조구 사료내 복합효소제를 0.1% 첨가한 처리구로 하였다. 사양시험기간동안, 일당증체량에 있어서는 대조구와 비교하여 EC0.1 처리구가 높은 것으로 평가되었으나 유의적인 차이는 보이지 않았다. 그러나 사료효율에 있어서는 대조구와 비교하여 EC0.1 처리구가 유의적으로 높게 평가되었다 (P<0.05). 건물과 질소 소화율에 있어서 대조구와 비교하여 처리구가 향상된 것으로 조사되었다 (P<0.05). 시험 2는 개시시 체중 22.30±0.45㎏의 3원 교잡종 육성돈 36두를 공시하였으며, 시험설계는 옥수수-대두박 위주의 사료에 NC (1998)의 영양소 요구량에 따라 처리한 대조구 (AME, adequate ME diet), 대조구 사료내 복합효소제를 0.1% 첨가한 처리구 (AME+EC0.1, Adequate ME diet + 0.1% 복합효소제), 대조구 사료에서 대사에너지 함량을 4% 낮춘 사료에 복합효소제를 0.1% 첨가한 처리구 (LME+EC0.1, Low ME diet + 0.1% 복합효소제)로 하였다. 총 30일간의 사양시험 기간동안, 일당증체량에 있어서는 AME 처리구와 비교하여 복합효소제 처리구가 유의적인 성장율이 높은 것으로 조사되었다 (P<0.05). 건물 및 질소 소화율에 있어서는 AME 처리구와 비교하여 복합효소제 첨가구가 유의적으로 높게 평가되었다 (P<0.05). 결론적으로, 자돈 및 육성돈 사료에 복합효소제의 첨가는 성장능력 및 영양소 소화율을 향상시키는 것으로 사료된다. For the Exp. I, a total of sixty pigs (10.57±0.30㎏ average initial body weight) were used in a 15-d growth assay to determine the effect of dietary α-1,6-galactosidase and β-1,4-mannanase on growth performance and nutrient digestibility. Dietary treatments included 1) CON (corn-dried whey-SBM based diet), 2) EC0.1 (CON diet + 0.1% enzyme complex of α-1,6-galactosidase and β-1,4-mannanase). Through the entire experimental period, gain/feed of pigs fed EC0.1 diet was higher (0.43 vs 0.52) than that of pigs fed CON diet (P<0.05). Pigs fed EC0.1 diet showed significant (P<0.05) improvement in dry matter (74.82% vs 82.41%) and nitrogen (70.59% vs 77.88%) digestibilities compared to pigs fed CON diet. For the Exp. 2, a total of thirty six pigs (22.30±0.45㎏ average initial body weight) were used in a 30-d growth assay to determine the effects of dietary α-1,6-galactosidase and β-1,4-mannanase in low energy diet on growth performance and nutrient digestibility. Dietary treatments included 1) AME (adequate ME diet), 2) AME+EC0.1 (AME diet + 0.1% enzyme complex) and LME+EC0.1 (low ME diet + 0.1% enzyme complex). Through the entire experimental period, average daily feed intake of pigs fed enzyme complex supplemented diets was higher than that of pigs fed CON diet (P<0.05). Also, pigs fed AME+EC0.1 diet showed significant (P<0.05) increase in ADFⅠ (1,401g vs 1,733g) compared to pigs fed CON diet. Pigs fed enzyme complex supplemented diet showed significant (P<0.05) improvement in dry matter and nitrogen digestibilities compared to pigs fed CON diet. In conclusion, the results obtained from these feeding trials suggest that the supplementation of α-1,6-galactosidase and β-1,4-mannanase was an effective means for improving growth performance and dry matter and nitrogen digestibilities in nursery and growing pigs.

열산화된 알루미늄이 첨가된 Tin black filter를 가지는 메탄센서

권오식,황숙이,심창현,임채근,방영일,김봉철,허증수,류기홍,이덕동 경북대학교 센서기술연구소 2002 센서技術學術大會論文集 Vol.13 No.1

경상북도 구미지역의 산성강우의 화학적 특성에 관한 연구

권오일,류성규,서길수 嶺南大學校 工業技術硏究所 1994 工業技術硏究所論文集 Vol.22 No.2

In this study the quantities of the inorganic ions in the precipitation of the area Gumi in Kyongbook Province were analyzed. The sampling period of the study was between January and May of 1994. Anion concentrations were determined by ion chromatography. Cation concentrations were analyzed by Atomic Absorption Spectroscopy and Induced Copper Plasma. The avrage pH of the rain was 4.99 in the Kongdan area, and 6.18 in the Wonpyong area. And the ratio of anion/cation were about 1.0.

이유자돈, 육성돈 및 비육돈에 있어 게르마늄흑운모의 급여 효과

권오석,김인호,홍종욱,이상환,정연권,민병준,이원백,손경승 한국동물자원과학회 2003 한국축산학회지 Vol.45 No.3

시험 1은 게르마늄흑운몰르 자돈 사료에 첨가하였을 때 자돈의 사료에 첨가하였을 때 자돈의 성장 및 영양소 소화율에 미치는 영향을 평가하고자 실시하였다. 공시동물은 평균 체중 15.09±0.18kg의 3원 교잡종자돈 60두를 공시하여 28일간 실시하였다. 시험설계는 기초사료에 게르마늄흑운모 무첨가구(CON; basal diet), 기초자료에 게르마늄흑운모 0.1%(GB0.1), 0.3%(GB0.3), 0.6%(GB0.6), 1.0%(GB1.0) 첨가구로 5개 처리로 하였다. 전체 사양시험 기간동안, 일당증체량과 사료효율에 있어서는 처리구간에 유의적인 차이를 보이지 않았다. 시험 2는 육성돈 사료내 게르마늄흑운모의 항생제 대체효과를 평가하기 위하여 실시하였다. 공시동물은 평균 체중이 32.47±0.90kg인 3원 교잡종 육성돈 54두를 공시하여 35일간 실시하였다. 시험설계는 기초사료에 항생제 무첨가구(NC; basal diet), 항생제 첨가구(PC; basal diet + 200ppm CTC), 게르마늄흑운모를 0.3% 첨가구 (GB0.3; basal diet + 0.3% germanium biotite)의 3개 처리로 하였다. 사양시험 기간동안, 일당증체량에 있어서 NC 처리구와 비교하였을 때 GB0.3 처리구의 성장율이 각각 17%(358 vs 451, g/d), 14% (385 vs 438, g/d) 높았다(p<0.05). 일당사료섭취량에 있어서 NC 처리구와 비교하여 PC 처리구와 GB0.3 처리구가 유의적으로 높았다(p<0.05). 사료효율에 있어서도 NC 처리구와 비교하여 GB0.3 처리구가 유의적으로 비교하여 GB0.3 처리구가 유의적으로 높았다(0.323 vs 0.332) (p<0.05). 외관상 건물과 질소 소화율에 있어서 NC 처리구와 비교하여 PC 처리구와 GB0.3 처리구가 유의적으로 높았다(P<0.05). 시험 3은 비육돈 사료내 게르마늄흑운모의 첨가가 성장, 영양소 소화율, 혈장 성상, 등지방두께 그리고 분내 암모니아 가스 농도에 미치는 영향을 평가하기 위하여 실시하였다. 공시동물은 평균 체중이 78.56±1.32kg인 비육돈 72두를 공시하였다. 시험설계는 기초사료에 게르마늄흑운모 무첨가구(CON; basal diet), 기초사료에 게르마늄흑운모 1.0% (BG1.0), 3.0%(GB3.0) 첨가구로 3개 처리로 하였다. 사양시험 기간동안, 일당증체량에서는 GB1.0 처리구가 대조구와 GB3.0 처리구와 비교하여 유의적으로 높았으며 (P<0.05), 일당사료섭취량에 있어서는 대조구가 GB3.0보다 유의적으로 높았다(P<0.05). 사료효율에 있어서는 GB 첨가구가 대조구와 비교하여 유의적으로 높게 조사되었다(P<0.05). 혈장내 Total-cholesterol 함량 변화는 대조구와 비교하여 게르나늄흑운모 첨가구가 유의적으로 감소하였다(P<0.05). 또한 LDL+ VLDL-cholesterol 함량 변화도 대조구와 비교하여 게르마늄흑운모 첨가구가 유의적으로 감소하였다(P<0.05). 혈장내 HDL-cholesterol 함량에 있어서는 대조구와 비교하여 게르마늄흑운모 첨가구가 유의적으로 증가하였다(P<0.05). 등지방 두께에 있어서는 대조구와 비교하여 GB1.0 처리구가 5.4% (27.19 vs 25.71mm)의 감소를 보였고, GB3.0 처리구가 대조구와 비교하여 16.1% (27.19 vs 22.81mm)로 유의적인 감소하였다 P<0.05). 게르마늄흑운모의 분내 암모니아 가스 농도에 미치는 영향에 있어서는, 대조구와 비교하여 GB1.0 처리구가 64.1% (17.00 vs 6.10mg/kg), GB3.0 처리구가 61.8% (17.00 vs 6.50mg/kg) 유의적으로 감소하였다. (P<0.05). 결론적으로, 양돈사료내 게르마늄흑운모를 첨가하였을 경우, 자돈에 있어서는 성장에 영향을 미치지 않는 것으로, 사료되며, 육성도에 있어서는 항생제 대체효과를 갖는 것으로 나타난다. 또한, 비육돈의 성장능력을 향상키시는 것으로 판단되며, 혈중 Total 및 LDL+VLDL-chole-sterol 함량을 감소시키며, HDL-cholesterol 함량을 증가시키는 것으로 판단된다. 또한 등지방 두께가 감소되며, 분내 암모니아 가스 농도가 감소하는 것으로 나타났다. In Exp. 1, this study was conducted to determine the effect of dietary germanium biotite on growth performance and nutrient digestibility in nursery pigs. A total of sixty crossbred pigs (initial body weight 15.09±0.18㎏) were used in this experiment. This study was carried out for 28 days. The five treatments were control (CON; basal diet), GB0.1 (basal diet + germanium biotite 0.1%), GB0.3 (basal diet+ germanium biotite 0.3%), GB0.6 (basal diet + germanium biotite 0.6%) and GB1.0 (basal diet + germanium biotite 1.0%). For overall period, ADG and Gain/feed were not significantly different among the treatments. In Exp. 2, a study was conducted to evaluate the effect of germanium biotite as a substitute for antibiotics in growing pigs. A total of fifty five crossbred pigs (initial body weight 32.47±0.9㎏) were used in this experiment. The three treatments were negative control (NC: basal diet without antibiotic), positive control (PC: basal diet + 200ppm CTC) and GB0.3 (basal diet + germanium biotite 0.3%). Pigs fed PC (17%, 385 vs 451 g/d) and GB0.3 (14%, 385 vs 438 g/d) diets grew faster(P<0.05) than pigs fed NC diet. Pigs fed PC and GB0.3 diets resulted higher(P<0.05) ADFI than pigs fed CON diet. However, pigs fed GB0.3 diet had improved gain/feed compared to pigs fed NC diet(P<0.05). Apparent digestibility of DM and N by pigs fed PC and GB0.3 diets were greater(P<0.05) than those by pigs fed NC diet. In Exp. 3, a study was conducted to determine the effect of dietary germanium biotite on growth performance, plasma characteristics, backfat thickness and fecal ammonia gas concentration in finishing pigs. A total of seventy-two finishing pigs (initial body weight 78.56±1.32㎏) were used in this experiment. The treatments included 1) Control (CON; basal diet) 2) GB1.0 (basal diet + germanium biotite 1.0%), 3) GB3.0 (basal diet + germanium biotite 3.0%). Pigs fed GB1.0 diet grew faster than pigs fed CON diet and GB0.3 diet (P<0.05). Also, pigs fed CON diet showed higher(p<0.05) ADFI than pigs fed GB3.0diet. Pigs fed GB diets had improved gain/feed compared to pigs fed CON diet(P<0.05). Total and VLDL concentrations in plasma of pigs fed GB diets treatments were significantly decreased compared to those in pig fed CON diet(P<0.05). However, HDL-cholesterol concentration in plasma of the pig was significantly increased compared to those in pigs fed CON diet (P<0.05). Pigs fed CON diet exerted higher(P<0.05) backfat thickness than pigs fed GB1.0 (5.4%, 27.19 vs 25.71㎜) and GB3.0 (16.1%, 27.19 vs 22.81㎜) diets. Feces from CON treatment were higher in fecal ammonia gas concentration than faces from pigs fed GB1.0 (64.1%, 17.00 vs 6.10㎎/㎏) and GB3.0 (61.8%, 17.00 vs 6.50㎎/㎏) treatments(P<0.05). In conclusion, the results suggest that the dietary addition of germanium biotite into diets for nursery pigs did not affect growth performance. The results also suggest the possibility of germanium biotite to replace antibiotic in diets for growing pigs. In finishing pigs, dietary supplementation of germanium biotite was an effective means for improving growth performance and for decreasing Total-and LDL+VLDL-plasma cholesterols, backfat and fecal ammonia gas concentration.

돼지에 있어 성장 , 영양소 소화율 및 사료비용에 관한 옥수수의 적정 입자도

김인호,이상환,홍종욱,권오석 한국동물자원과학회 2001 한국축산학회지 Vol.43 No.2

Two experiments were conducted to determine the optimum particle size of corn for growth performance, nutrient digestibility in pigs and cost effectiveness for the fine grinding. In Exp. 1, 72 nursery pigs(Duroc × Yorkshire × Landrace, average initial body weight 12.36±0.59㎏) were blocked by initial weight with weight and with six pigs per pen and six pens per treatment. The corn was ground in a hammermill through either screen opening of 3㎜(fine particle) or 4.5㎜(coarse particle). For 28 d, pigs fed fine corn diet were higher(P$lt;0.05) in average daily gain(ADG) than those fed coarse one, whereas no significant difference in average daily feed intake(ADFI) was found between the dietary treatments. Gain/feed and DM and N digestibility of pigs fed the fine corn diet were significantly improved compared to those of pigs fed the coarse corn diet(P$lt;0.05). In Exp. 2, a total of 48 finishing pigs(Duroc × Yorkshire × Landrace, average initial body weight 47.54±0.69㎏) were used in a 28 d growth assay. The corn was ground in a hammermill through either screen opening of 3㎜(fine particle) or 6㎜(coarse particle). During the experimental period, ADG, ADFI and G/F were not significant different between the treatments(P$gt;0.05). DM and N digestibility and intake of digestible nutrients were greater for pigs fed the fine corn diet than those fed the coarse one(P$lt;0.05). Also, pigs fed the fine corn diet had decreased fecal nutrient excretion compared to those fed the coarse com diet(P$lt;0.05). Total feed cost per ㎏ of weight gain was higher(921 vs 84l won) in the coarse group than in the fine one. In conclusion. fine particle size of com resulted in greater growth performance and nutrient digestibility than coarse particle size of corn in nursery and finishing pigs.