• Title/Summary/Keyword: ${\sigma}$-ideal

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Consumer Intention to Purchase Domestic/Foreign Brand Jeans;Beliefs, Attitude, and Individual Characteristics. (국내 및 외국 상표 청바지의 구매의도에 따른 평가기준에 대한 신념과 추구이미지 및 의복태도의 차이연구)

  • 고애란
    • Journal of the Korean Society of Clothing and Textiles
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    • v.18 no.2
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    • pp.263-272
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    • 1994
  • The purpose of this study was to identify factors that might distinguish those who have a high level of Intention to purchase each of domestic, foreign designer and national brand jeans from those who have a low intention in terms of evaluative criteria belief, ideal jeans image and clothing altitude. The sample consisted of 198 male and 197 female students from five universities in Seoul. The questionnnaire consisted of 50 seven-point semantic differential scales dealing with evaluative criteria and ideal jeans image, beliefs about and intention to purchase domestic, foreign designer and foreign national brand jeans and 25 Likert type clothing attitude scales. Based on a series of t-tests the results showed that color and design were the most influencing factor among the evaluative criteria belief, regardless of brand type, while durability, accessory, sewing were the least. Sexy image, brand consciousnees and fashion interest were the important factor that distinguish high intention to purchase group fro)m low intention to purchase group.

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Two Anhydrous Zeolite X Crystal Structures, $Pd_{18}Ti_{56}Si_{100}Al_{92}O_{384} and Pd_{21}Tl_{50}Si_{100}Al_{92}O_{384}$

  • Yun, Bo Yeong;Song, Mi Gyeong;Lee, Seok Hui;Kim, Yang
    • Bulletin of the Korean Chemical Society
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    • v.22 no.1
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    • pp.30-36
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    • 2001
  • The crystal structures of fully dehydrated $Pd^{2+}$ - and $TI^{+}$ -exchanged zeolite X, $Pd_{18}TI_{56}Si_{100}Al_{92}O_{384}(Pd_{18}TI_{50-}X$, a = $24.935(4)\AA$ and $Pd_{21}TI_{50}Si_{100}Al_{92}O_{384}(Pd_{21}TI_{50-}X$ a = $24.914(4)\AA)$, have been determined by single-crystal X-ray diffraction methods in the cubic space group Fd3 at $21(1)^{\circ}C.$ The crystals were prepared using an exchange solution that had a $Pd(NH_3)_4Cl_2\;:TINO_3$ mole ratio of 50 : 1 and 200 : 1, respectively, with a total concentration of 0.05M for 4 days. After dehydration at $360^{\circ}C$ and 2 ${\times}$$10^{-6}$ Torr in flowing oxygen for 2 days, the crystals were evacuated at $21(1)^{\circ}C$ for 2 hours. They were refined to the final error indices $R_1$ = 0.045 and $R_2$ = 0.038 with 344 reflections for $Pd_{18}Tl_{56-}X$, and $R_1$ = 0.043 and $R_2$ = 0.045 with 280 reflections for $Pd_{21}Tl_{50-}X$; I > $3\sigma(I).$ In the structure of dehydrated $Pd_{18}Tl_{56-}X$, eighteen $Pd^{2+}$ ions and fourteen $TI^{+}$ ions are located at site I'. About twenty-seven $TI^{+}$ ions occupy site II recessed $1.74\AA$ into a supercage from the plane of three oxygens. The remaining fifteen $TI^{+}$ ions are distributed over two non-equivalent III' sites, with occupancies of 11 and 4, respectively. In the structure of $Pd_{21}Tl_{50-}X$, twenty $Pd^{2+}$ and ten $TI^{+}$ ions occupy site I', and one $Pd^{2+}$ ion is at site I. About twenty-three $TI^{+}$ ions occupy site II, and the remaining seventeen $TI^{+}$ ions are distributed over two different III' sites. $Pd^{2+}$ ions show a limit of exchange (ca. 39% and 46%), though their concentration of exchange was much higher than that of $TI^{+}$ ions. $Pd^{2+}$ ions tend to occupy site I', where they fit the double six-ring plane as nearly ideal trigonal planar. $TI^{+}$ ions fill the remaining I' sites, then occupy site II and two different III' sites. The two crystal structures show that approximately two and one-half I' sites per sodalite cage may be occupied by $Pd^{2+}$ ions. The remaining I' sites are occupied by $TI^{+}$ ions with Tl-O bond distance that is shorter than the sum of their ionic radii. The electrostatic repulsion between two large $TI^{+}$ ions and between $TI^{+}$ and $Pd^{2+}$ ions in the same $\beta-cage$ pushes each other to the charged six-ring planes. It causes the Tl-O bond to have some covalent character. However, $TI^{+}$ ions at site II form ionic bonds with three oxygens because the super-cage has the available space to obtain the reliable ionic bonds.

The Crystal and Molecular Structure of 25,26,27,28-Tetrnacetoxy[4]Arene${\cdot}$Monohydrate (25,26,27,28-테트라아세트오키시[4]에렌${\cdot}$일수화물의 결정 및 분자구조)

  • Choong Tai Ahn;Kwanghyun No
    • Journal of the Korean Chemical Society
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    • v.37 no.3
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    • pp.344-350
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    • 1993
  • 25,26,27,28-Tetraacetoxycalix[4]arene·monohydrate is orthorhombic, space group Pbca with a = 14.979(4), b = 15.154(4), c = 27.890(3) ${\AA}$, Z = 8, V = 6330.6 ${\AA}^{-3}$, D$_c$ = 1.28 $g{\cdot}cm^{-3}$, (Mo K${\alpha}$) = 0.71069 ${\AA}$, ${\mu}$ = 0.86 cm$^{-1}$, F(000) = 2600, and R = 0.069 for 3376 unique observed reflections with I > 1.0 ${\sigma}$(I). The structure was solved by direct methods and refined by cascade diagonal least-squares refinement. All the C-H bond lengths(= 0.96 ${\AA}$), the methyl groups and the methylene groups are fixed and refined as the rigid groups with ideal geometry. The macrocycle exists in the 1,3 alternate conformation (by Conforth) making the angles of 110.7, 684, 113.7 and 68.8$^{\circ}$ between the benzene rings and the methylenic mean plane, and four each acetoxy groups are twisted away from their own benzene rings with the angles of 68.2, 97.6, 78.9 and 71.3$^{\circ}$, respectively. The relative dihedral angles between two opposite side of the benzene rings are 135.6$^{\circ}$ for the rings (1) and (3) and 135.2$^{\circ}$ for (2) and (4). A water molecule which has nearly the same height of the methylenic plane of the macrocycle in the c-axis, is located within the distances of 2.942(5) ${\AA}$ from the O(8) atom of the carbonyl group and 2.901 ${\AA}$ from, another O(2)(1/2-x, -1/2+y, z). The shortest contact between the molecule is 3.193 ${\AA}$ from the O(4) to the C(3)(1/2+x, 1/2-y,-z).

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