• Macromolecular Research
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• v.12 no.3
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• pp.316-321
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• 2004

We have performed copolymerizations of ethylene with 1-hexene using various ansa-metallocene compounds in the presence of the non-coordinative [CPh$_3$][B(C$\_$6/F$\_$5/)$_4$ion pair as a cocatalyst. The metallocenes chosen for this study are isospecific metallocene diamide compounds, rac-(EBI)Zr(NMe$_2$)$_2$ [1, EBI = ethylene-l ,2-bis(1-indenyl)], rac-(EBI)Hf(NMe$_2$)$_2$ (2), rac-(EBI)Zr(NC$_4$H$\_$8/)$_2$ (3), and rac-(CH$_3$)$_3$Si(1-C$\_$5/H$_2$-2-CH$_3$-4-$\^$t/C$_4$H$\_$9/)2 Zr(NMe$_2$)$_2$ (4), and syndiospecific metallocene dimethyl compounds, ethylidene(cyclopentadienyl)(9-fluorenyl) ZrMe$_2$ [5, Et(Flu)(Cp )ZrMe$_2$] and isopropylidence (cyclopentadienyl)(9-fluorenyl)ZrMe$_2$ [6, iPr(Flu)(Cp)ZrMe$_2$]. The copolymerization rate decreased in the order 4 ＞1-3＞2 ＞5＞6. The reactivity of I -hexene decreased in the order 2 ＞6＞1- 3-5＞ 4. We characterized the microstructure of the resulting poly(ethylene-co-l-hexene) by $\^$l3/C NMR spectroscopy and investigated various other properties of the copolymers in detail.

• Bulletin of the Korean Chemical Society
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• v.28 no.2
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• pp.336-338
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• 2007

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.12
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• pp.1781-1784
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• 2001

We have examined the influence of antisense oligo deoxynucleotide (ODN) of IGFBP-2 on tissue IGFBP-2 gene expression in chicks. Antisense IGFBP-2 ODN was directly injected into the liver or cerebroventricle. Control birds were injected with vehicle. The hepatic IGFBP-2 gene expression was decreased to approximately 30% of the control at 2 h after injection of antisense ODN. In the brain of chickens injected with antisense ODN, IGFBP-2 mRNA level did not change after 2 h of injection and decreased to approximately 60% of the control after 6 h of injection. These results showed that the expression of IGFBP-2 gene in the liver and brain was successfully suppressed by administrating antisense ODN and that hepatic IGFBP-2 gene expression was quickly suppressed by antisense ODN compared with the brain.

• Journal of the Korean Mathematical Society
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• v.54 no.5
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• pp.1505-1519
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• 2017

Assume that M is an R-module where R is a commutative ring. A proper submodule N of M is called a weakly 2-absorbing primary submodule of M if $0{\neq}abm{\in}N$ for any $a,b{\in}R$ and $m{\in}M$, then $ab{\in}(N:M)$ or $am{\in}M-rad(N)$ or $bm{\in}M-rad(N)$. In this paper, we extended the concept of weakly 2-absorbing primary ideals of commutative rings to weakly 2-absorbing primary submodules of modules. Among many results, we show that if N is a weakly 2-absorbing primary submodule of M and it satisfies certain condition $0{\neq}I_1I_2K{\subseteq}N$ for some ideals $I_1$, $I_2$ of R and submodule K of M, then $I_1I_2{\subseteq}(N:M)$ or $I_1K{\subseteq}M-rad(N)$ or $I_2K{\subseteq}M-rad(N)$.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.167.2-167.2
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• 2014

In this work, ZnO shell on mesoporous $SiO_2$ ($ZnO/SiO_2$) was prepared by atomic layer deposition (ALD). Diethylzinc (DEZ) and $H_2O$ were used as precursor of ZnO shell. $ZnO/SiO_2$ sample was characterized by X-ray diffraction (XRD), N2 sorption isotherms, X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FT-IR). $ZnO/SiO_2$ showed higher adsorption capacity of MB than that of bare mesoporous $SiO_2$ and the adsorption capacities of $ZnO/SiO_2$ could be regenerated by UV exposure through the photocatalytic degradation of the adsorbed MB. This system could be used for removing organic dye from water by adsorption and reused after saturation of adsorption due to its photocatalytic regeneration.

• Journal of the Korean Chemical Society
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• v.13 no.1
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• pp.16-24
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• 1969

Ni, Co, Zn, Cd, Mn, Mg, Ca, Sr, Ba 등의2가 금속과 U(VI) 및 V(IV)의 이온이 만드는 $MCup_2$ 조성의 cupferrates 착화합물에 관하여, 그 용해도가 좋은 dioxane-$H_2O$, methanol-$H_2O$, ethanol-$H_2O$ 및 2-propanol-$H_2O$의 혼합용매를 사용하여, 그들의 몰분율을 변화시키면서 제 1, 제 2 및 전체의 열역학적인 안정도상수를 전위차적정법에 의하여 측정하고, 안정도 상수와 유기용매의 몰분율에 관한 실험식을 얻었다. 한편 분광광전법에 의하여 가능한 cupferrates의 전체 안정도 상수를 측적하여 이들과 비교하였다. 2가 금속 cupferrates의 안정도상수는 위에 적은 금속의 순서로 감소하고, 이들의 log $K_1$은 log $K_2$보다 크지만, U(VI)과 V(IV)의 cupferrates는 log $K_1$$K_2$여서 1:1과 1:2 착화합물 사이에 구조 변화가 있는듯하다. 몰분율이 영인 점에서의 안정도상수는 금속 cupferrates의 수용액에서의 용해반응의 평형상수에 해당하며, 금속의 착화합물의 안정도상수와 용해도와는 무관하고, K<$10^5$인 cupferrates에 관해서는 분광전법을 적용하기 어렵다.

• Journal of the Korean Chemical Society
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• v.33 no.4
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• pp.371-378
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• 1989

Kinetics of the substitution reaction of [pt[dien]X]$^+$(X = $Cl^-$, $Br^-$, $I^-$) with NO2- in aqueous solution were investigated by a spectrophotometric method at $20-35^{\circ}C$ and 1-1500 bars. The rates of these reactions were increased with raising temperature and pressure. The relative reactivities of replaceable ligands in [pt[dien]X]$^+$ follow the order ($Cl^-$ > $Br^-$ > $I^-$). Activation volumes (${\mid}{\Delta}V^{\neq}{\mid}$) were large negative values and decreased with raising temperature. First ($k_1$) and second($k_2$) order rate constants of these reactions were determined at $25^{\circ}C$ and both $k_1$ and $k_2$ were increased with raising pressure and activation volumes (${\Delta}{V_1}^{\neq}$, ${\Delta}{V_2}^{\neq}$) for the $k_1$ and $k_2$ path were large negative values respectively. The $k_1$ and $k_2$ of these reactions were determined at 1 bar and these values were increased with raising temperature. Activation parameters of $k_1$ and $k_2$ path were determined, therefore it can be inferred frp, these results that the substitution reactions of [pt[dien]X]$^+$ with ${NO_2}^-$ proceed through on associative (A) mechanism independent of a leaving groups and reaction paths.

• Korean journal of applied entomology
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• v.53 no.3
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• pp.247-260
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• 2014

To identify the species of Trichogramma occurring in the corn fields of Korea as egg parasitoids of Ostrinia furnacalis, we sequenced the full-length of ITS2 nuclear rDNA from 112 parasitoids collected during this study. As a reference to distinguish species, we also retrieved full-length ITS2 sequences of 60 Trichogramma species from the NCBI GenBank database. On the basis of the size and 3'terminal sequence pattern of the ITS2 sequences, the Trichogramma samples collected in this study were divided into three groups (K-1, -2, and -3). Evolutionary distances (d) within and between groups based on ITS2 sequences were estimated to be ${\leq}0.005$ and ${\geq}0.080$, respectively. In the net average distance between groups or species, the d value between K-1 and T. ostriniae, K-2 and T. dendrolimi, and K-3 and T. confusum was the lowest, with values of 0.016, 0.001, and 0.002, respectively. In the phylogenetic tree, K-1 and K-2 were clustered with T. ostriniae and T. dendrolimi, respectively. However, K-3 was clustered with three different species, namely, T. confusum, T. chilonis, and T. bilingensis. NCBI BLAST results revealed that parasitoids belonging to K-1 and K-2 showed 99% identity with T. ostriniae and T. dendrolimi, respectively. Parasitoids in K-3 collected from Hongcheon showed 99-100% identity with T. confusum and T. chilonis, and one parasitoid in K-3 collected from Gochang had 98% identity with T. bilingensis, T. confusum, and T. chilonis. On the basis of these results, we infer that the species of Trichogramma collected in this study are closely related to T. ostriniae (K-1) and T. dendrolimi (K-2). However, it was not possible to distinguish species of K-3 using the ITS2 sequence alone.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.1
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• pp.55-62
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• 2012

The present paper investigates the performance of the KOH aqueous solution as an absorbent to capture carbon dioxide ($CO_2$). The chemical absorption was carried out according to consecutive reactions that are generated in the order of $K_2CO_3$ and $KHCO_3$. The overall absorption was completed with following the physical absorption. When the absorption was conducted with the KOH as the limiting reactants in batch a reactor, $K_2CO_3$ production rate was the 1st order reaction for $OH^-$. However, $KHCO_3$ generation reaction was independent of the $CO_3^{2-}$ concentration and the rate was calculated to be $0.18gCO_2/min$ for all KOH absorbents, which is the same value of the reaction rate using $K_2CO_3$ aqueous solution as the absorbents. The overall $CO_2$ capture ratio of the 5% KOH absorbent was estimated to be 19% and the individual value in section 1 and 2 was 57 and 12%, respectively. The amount of $CO_2$ absorbed in the solution was very slightly less than the theoretical value, which was ascribed to the side reaction that produces $K_2CO_3{\cdot}KHCO_3{\cdot}1.5H_2O$ during the reaction and the consequent diminish in $CO_2$ absorption in the KOH solution.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1517-1522
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• 2012

Anion effects on structures of $Cd^{II}$ complexes containing 2,2'-bipyridine (2,2'-bpy) ligands have been studied, and compared with $Zn^{II}$-(2,2'-bpy) complexes. For each anion, different structures have been obtained in both $Zn^{II}$-(2,2'-bpy) and $Cd^{II}$-(2,2'-bpy). Polymeric structures of $Cd^{II}$-2,2'-bpy complexes can be produced by hydrogen bonding interactions as shown in $Zn^{II}$-2,2'-bpy complexes. In addition, the bigger size of a $Cd^{II}$ ion gives higher coordination numbers forming variety of structures, and it makes that chlorides can act as bridging ligands to form a one-dimensional structure. The compound $\mathbf{5}$ catalyzed efficiently the transesterification of a variety of esters with methanol, while the rest of the compounds have displayed very slow conversions. In addition, the emission bands of complexes $\mathbf{1}$, $\mathbf{2}$, $\mathbf{4}$, and $\mathbf{6}$ are blue-shifted compared to the corresponding ligand 2,2'-bpy, whereas $\mathbf{3}$ and $\mathbf{5}$ showed the similar emission observed for the ligand.