• 제목/요약/키워드: Chair structure

검색결과 68건 처리시간 0.028초

피록시캄의 용매 비의존 결정구조 (The Solvent-Independent Structure of Piroxicam)

  • 김봉희;서일환;지옥인;서종명;서정진
    • Journal of Pharmaceutical Investigation
    • /
    • 제18권4호
    • /
    • pp.209-215
    • /
    • 1988
  • The three-dimensional structures of piroxicam crystallized from two different solvents, toluene and toluene/hexane mixture respectively, are proved identical: $C_{15}H_{13}N_3O_4S,\;M\;=\;331.35$, monoclinic, a = 7.128(1), b = 15.146(2), c = 13.956(2) ${\AA},\;{\beta}=\;97.33(1)^{\circ},\;V\;=\;1494.37{\AA}^{3},\;Dx\;=\;1.472\;g/cm^{3},\;Z\;=\;4,\;space\;group\;P2_{1}/c,\;Mo\;K{\alpha}(\lambda=\;0.71073\;{\AA})$, F(000) = 688, T = 295 K, R = 0.0611 for 1993 unique observed reflections. The thiazine ring exhibits a half chair conformation. An amide group is involved in an intramolecular hydrogen bond to the hydroxy group, O(17)-H(17)${\cdots}O(15){\AA}$. The molecule is planar within 2 ${\AA}$ with the interplanar angle $127.9(4)^{\circ}$ between pyridine and benzene rings. A molecular chain parallel to [011] is formed by two intermolecular hydrogen bonds N(16)-H(6)${\cdots}O(11)$ and C(6)-H(6)${\cdots}O(11)$, and the molecular chains are held together by van der Waals forces.

  • PDF

Crystal Structure of 3-[4-(2-Ethoxy-2-phenylethyl)-1-piperazinyl]-2-methyl-1-phenyl-1-propanone (Eprazinone) dihydrochloride, $C_{24}H_{32}N_2O_2$·2HCl

  • Euisung Kim;Hyun Song;Choong-Souh Yun;Hyun-So Shin
    • Bulletin of the Korean Chemical Society
    • /
    • 제12권4호
    • /
    • pp.371-373
    • /
    • 1991
  • The crystal structure of eprazinone dihydrochloride, $C_{24}H_{32}N_2O_2$${\cdot}$2HCl, has been determined from 2102 independent reflections collected on an automated Nonious CAD-4 diffractometer using graphite-monochromated $Mo-K\alpha$ radiation. The crystals are monoclinic, space group P$2_1$/n, with unit cell dimensions a=11.381(2), b=28.318(2), c=7.840(1) $\AA$, $\beta=92.45(2)^{\circ}$, ${\mu}=2.37$ c$m^{-1}$, F(000)=968, and Z=4. Final R value is 0.071 for independent 2102 observed reflections. The molecule assumes an extended conformation. The piperazine ring has a normal chair conformation and the four carbon atom are planar with a maximum displacement of 0.004 $\AA$ for C(18) atom. The two chloride ions are hydrogen bonded to the two piperazine nitrogen atoms [N(14)${\cdot}{\cdot}{\cdot}$Cl(1); 2.986(6) $\AA$ N(17)…Cl(2); 3.084(8) $\AA$].

Theoretical Investigation on the Structure, Detonation Performance and Pyrolysis Mechanism of 4,6,8-Trinitro-4,5,7,8-tetrahydro -6H-furazano[3,4-f]-1,3,5-triazepine

  • Li, Xiao-Hong;Zhang, Rui-Zhou;Zhang, Xian-Zhou
    • Bulletin of the Korean Chemical Society
    • /
    • 제35권5호
    • /
    • pp.1479-1484
    • /
    • 2014
  • Based on the full optimized molecular geometric structures at B3LYP/cc-pvtz method, a new designed compound, 4,6,8-trinitro-4,5,7,8-tetrahydro-6H-furazano[3,4-f ]-1,3,5-triazepine was investigated in order to look for high energy density compounds (HEDCs). The analysis of the molecular structure indicates that the seven-membered ring adopts chair conformation and there exist intramolecular hydrogen bond interactions. IR spectrum and heat of formation (HOF) were predicted. The detonation velocity and pressure were evaluated by using Kamlet-Jacobs equations based on the theoretical density and condensed HOF. The bond dissociation energies and bond orders for the weakest bonds were analyzed to investigate the thermal stability of the title compound. The results show that $N_1-N_6$ bond is the trigger bond. The crystal structure obtained by molecular mechanics belongs to $Pna2_1$ space group, with lattice parameters Z = 4, a = 15.3023 ${\AA}$, b = 5.7882 ${\AA}$, c = 11.0471 ${\AA}$, ${\rho}=2.06gcm^{-3}$. In addition, the analysis of frontier molecular orbital shows the title compound has good stability and high chemical hardness.

르 꼬르뷔지에와 알바 알토의 가구디자인 특성 비교 연구 (A Study on Comparing Characteristics of Le Corbusier′s Furniture Design with Alvar Aalto′s)

  • 이진영
    • 한국실내디자인학회논문집
    • /
    • 제13권5호
    • /
    • pp.162-172
    • /
    • 2004
  • Architects and designers of the 20th Century made various efforts to establish new design languages reflecting the changes of society, the times, and environment. They used furniture, especially chairs, as controversial items of aesthetic value, society and ideology. Le Corbusier and Alvar Aalto are furniture designers as well as architects, who adopted this ‘spirit of the times’ actively and have greatly contributed to modernism. This study will help us to understand the diversity of design since modernism, by comparing these two designers' furniture design. It also covers the common factors In modern furniture design, and analyses their individuality and likeness In design. The following is a comparison of furniture design by Le Corbusier and Alvar Aalto. Le Courbusier linked International design and Aalto linked Rational design and Organic concept design to their furniture, just as they did in their architecture. They were able to establish the base of modern furniture design by adapting new concepts and pursuing humanism. In structure, Le Corbusier's furniture Is simple and proportional. It demonstrates a sophisticated geometric composition, mechanical beauty. On the other hand, Aalto rationally linked nature with human requirements and his furniture is organic and in harmony with geometric structure. In function, Le Corbusier's furniture is standardized and prefabricated. He designed for the user so they could choose to use the furniture efficiently to suit their needs. In comparison with Le Corbusier, Aalto Invented the ‘Stacking Chair’ which allows a more effective use of space and reflected the structure of the human body to improve the user's comfort. In materials and techniques, Le Corbusier used new materials like metal or leather, and attempted new ways such as welding, prefabrication, and standardization for production. On the contrary, Alto mainly used birch, which is the traditional material in Finland, and tried new bent wood techniques and joining methods.

『미생』에 나타난 신체 행위소 구조의 이중성에 관한 고찰 - 장그래를 중심으로 (On a "duality" of the Corps-actant structure in Misaeng: with Jang Geurae as the central figure)

  • 송태미
    • 기호학연구
    • /
    • 제57호
    • /
    • pp.211-255
    • /
    • 2018
  • 본 논문은 한때 "노동"을 주제로 한 공론의 장에서 이슈가 되었던 웹툰 "미생"의 '다시 읽기'를 시도하였다. 주인공 장그래의 행위소 구조가 갖는 이중적 성격이 텍스트 전체에 이중적 구조를 부여하며 이는 기존 담론의 장에서 이야기되지 않았던 텍스트 의미를 발견토록 해준다는 것이 우리의 독서 가설이었다. 이는 아즈마 히로키가 그의 포스트모던 문학론에서 이야기한 '탈이야기적 캐릭터' 개념에 기초한 생각이다. 우리는 본 가설을 확인하기 위해 파리학파의 주축을 이루는 기호학자 퐁타뉴의 이론을 적용하여 작품을 분석하였다. 장그래는 발화체 층위의 주체 '캐릭터'와 발화 층위의 주체 '플레이어'로 분열된 이원적 행위소 구조를 보인다. 인물의 이러한 특징을 고려하면 본 작품은 발화체 주체와 발화 주체 간의 '연동/탈연동' 관계를 메타 픽션의 양식으로 보여주는 텍스트로 해석될 수 있다. 캐릭터 층위에서 장그래는 "결핍(현동화)"의 현존양식을 보이지만 플레이어 층위에서 장그래는 "무력감(가능화)"의 현존양식을 보인다. 그의 신체성 또한 이원적 성격을 보이는데 이를 신체-행위소 모델로 나타내면, 캐릭터 층위에서 장그래는 육적 자아와 동일성-자기가 결합된 행위소로, 플레이어 층위에서는 주로 내부수용적 지각을 담당하는 육적 자아와 자기성-자기가 결합된 행위소로 이해될 수 있다. 전자가 주로 '역할'로서 움직이며 외부수용적 지각을 담당한다면 후자는 주로 '태도'로서 움직이며 내부수용적 지각을 담당한다. 이 해리적 성격으로 인해 장그래의 두 '자기'는 환경이 요구하는 가치 체계와 개인의 독자성 사이에서 큰 갈등을 겪지 않고 가치의 재조정을 유도한다. 이는 환경과 '자기' 사이의 갈등을 겪으며 고뇌하는 다른 등장인물들과 뚜렷한 대비를 이룬다. 실효성이 의심되는 규범을 습관적으로 받아들이면 관례가 되지만 문제 제기를 하면 규범 체계는 업데이트될 수 있다. 본 작품의 한 축에는 관례 속에 매몰되어 자기를 잃어버린 인물들이 있고 다른 한 축에는 기존 규범을 해체시키고 체계를 업데이트하는 방식 외에 달리 살 수 없는 장그래가 있다. 장그래는 가치 포화의 시대, 공동체적 가치 공유가 불가능한 이 시대에 개인이 가질 수 있는 여러 가능한 현존양식 가운데 하나를 보여주는 인물이며 이러한 행위소 구조는 또한 발화체 주체보다 발화 주체에 더욱 감정이입하는 오늘날의 독자와 소통한다.

Guided endodontics: a case report of maxillary lateral incisors with multiple dens invaginatus

  • Ali, Afzal;Arslan, Hakan
    • Restorative Dentistry and Endodontics
    • /
    • 제44권4호
    • /
    • pp.38.1-38.8
    • /
    • 2019
  • Navigation of the main root canal and dealing with a dens invaginatus (DI) is a challenging task in clinical practice. Recently, the guided endodontics technique has become an alternative method for accessing root canals, surgical cavities, and calcified root canals without causing iatrogenic damage to tissue. In this case report, the use of the guided endodontics technique for two maxillary lateral incisors with multiple DIs is described. A 16-year-old female patient was referred with the chief complaint of pain and discoloured upper front teeth. Based on clinical and radiographic findings, a diagnosis of pulp necrosis and chronic periapical abscess associated with double DI (Oehler's type II) was established for the upper left lateral maxillary incisor (tooth #22). Root canal treatment and the sealing of double DI with mineral trioxide aggregate was planned for tooth #22. For tooth #12 (Oehler's type II), preventive sealing of the DI was planned. Minimally invasive access to the double DI and the main root canal of tooth #22, and to the DI of tooth #12, was achieved using the guided endodontics technique. This technique can be a valuable tool because it reduces chair-time and, more importantly, the risk of iatrogenic damage to the tooth structure.

Neo-inositol 및 Scyllo-inositol의 結晶 및 分子 構造 (The Crystal and Molecular Structures of Neo-inositol and Two Forms of Scyllo-inositol)

  • Yeon, Younghee
    • 한국결정학회지
    • /
    • 제12권3호
    • /
    • pp.150-156
    • /
    • 2001
  • Nea-inositol is triclinic P???, with a =4.799(1), b=6.520(1), c=6.505(1) Å, α=70.61(1), β=69.41(1), γ=73.66(1)°, Z=1, molecular symmetry ???. Scyllo-inositol, from A, is monoclinic, P2₂/c, with a=5.089(1), c=11.948(2)Å, β=116.98(2)°, Z=2, molecular symmetry ???. Form B is triclinic, P???, with a=6.725(1), b=6.797(1), c=8.635(2)° Å, α=95.45(2), β=99.49(2), γ=99.19(2)°, Z=2, molecular symmetry ???. This crystal structure is pseudo-monoclinic, having two centrosymmetrical molecules with the almost identical conformation and orientation in the crystal lattice. The molecules have the expected chair conformations with puckering parameters of Q=0.609(2)Å for n대, 0.581(2)Å for Scyllo-A, and 0.566(2) Å for Scyllo-B. The bond lengths and angles are normal, C-C, 1.505 to 1.531 8A, C-O, 1.415 to 1.440 Å, C-C-C, 108.2 to 112.9°. The molecules are linked by systems of finite and infinite chains of hydrogen bonds.

  • PDF

강의실용 의자 일체형 책상 접이구조 설계방안에 관한 연구 (A Study on the Structure Design for the Desk Chair of the Folding Desk type in the Lecture)

  • 김덕유;김평경;전의식
    • 한국산학기술학회:학술대회논문집
    • /
    • 한국산학기술학회 2008년도 추계학술발표논문집
    • /
    • pp.430-432
    • /
    • 2008
  • 학교와 같이 대단위 교육을 수행하는 곳에서 필수적으로 사용되는 것은 강의실 의자이다. 소비자 중심적인 시대적 변화에 따라 많은 제품들이 다양한 소비자의 요구가 반영되어 출시되고 있으나, 강의실 의자는 아직 이러한 요구가 받아들여지지 않거나 무시되고 있다. 강의실에서 학생들이 가장 불편해 하는것은 자신의 신체치수에 적합하지 않는 강의실 의자이다. 따라서 본 연구에서는 다양한 신체치수를 반영할 수 있는 가변형 강의실용 의자를 개발하고자 한다. 신체치수는 앉은키와 체형을 고려하여 앉고 일어서는데 불편함이 없도록 책상 접힘과 의자와의 거리조절이 가능하고, 사람의 신장에 따라 높낮이 조절이 가능한 구조로 설계하여 기존의 평균책상 사이즈에 구애받지 않고 사용자의 신체구조에 따라 자유롭게 조절시켜 장시간 의자에 앉아 있을 때 불편함을 개선하고 불균형한 자세 등을 교정시켜 줌으로써, 학업 시 바른 자세를 유도하며 학업능률을 향상시킬 것으로 기대한다.

  • PDF

Salicylaldehyde-4-morpholinothiosemicarbazone의 결정 및 분자구조 (The Crystal and Molecular Structure of Salicylaldehyde-4-morpholinothiosemicarbazone)

  • 구정회;김훈섭;안중태
    • 대한화학회지
    • /
    • 제21권1호
    • /
    • pp.3-15
    • /
    • 1977
  • Salicylaldehyde-4-morpholinothiosemicarbazone, $C_{12}H_{15}O_2N_3S$, 결정은 직각비등축정계에 속하며 공간군은 $Pna2_1$이다. 단위세포에는 4개의 분자가 포함되면 세포 길이는 a = 11.85(5), b = 15.45(5), c = 7.18(3)${\AA}$이다. 농도는 multiple-film equi-inclination Weissenberg 사진으로부터 3차원적 농도 데이타를 얻어 목측법에 의하여 측정하였다. 결정구조는 Patterson 및 Fourier법으로 해명하였으며 구조의 정밀화는 block-diagonal 최소자승법으로 하였으며 R값은 1064개의 반사에 대하여 0.11이었다. 몰포린 고리는 의자형이며 1분자내의 몰포린 고리와 황원자를 제외한 원자들은 대략 한 평면을 이룬다. 수산화기의 산소원자는 질소원자와 2.67${\AA}$의 거리로 $O-H{\cdot}{\cdot}{\cdot}N$형 수소결합을 하고 있고 분자간에는 van der Waals 접촉으로 연결되어 있다.

  • PDF

The sphenopalatine vein: anatomical study of a rarely described structure

  • Joe Iwanaga;Eric Pineda;Yusuke Miyamoto;Grzegorz Wysiadecki;Samir Anadkat;R. Shane Tubbs
    • Anatomy and Cell Biology
    • /
    • 제56권2호
    • /
    • pp.200-204
    • /
    • 2023
  • Although in counterpart, the sphenopalatine artery (SPA), has been well described in the medical literature, the sphenopalatine vein (SPV) has received scant attention. Therefore, the present anatomical study was performed. Additionally, we discuss the variations, embryology, and clinical significance of the SPV. Adult cadaveric specimens underwent dissection of the SPV. In addition, some specimens were submitted for histological analysis of this structure. The SPV was found to drain from the sphenoidal sinus and nasal septum. Small tributaries traveled through the nasal septum with the posterior septal branches of the SPA and nasopalatine nerve. The SPA and SPV were found to travel through the sphenopalatine foramen and another tributary was found to perforate the medial plate of the pterygoid process and to connect to the pterygoid venous plexus which traveled lateral to the medial plate of the pterygoid process. The vein traveled through the posterior part of the lateral wall of the nasal cavity with the posterior lateral nasal branches of the SPA and the lateral superior posterior nasal branches of the maxillary nerve. To our knowledge, this is the first anatomical study on the SPV in humans. Data on the SPV provides an improved anatomical understanding of the vascular network of the nasal cavity. Developing a more complete picture of the nasal cavity and its venous supply might help surgeons and clinicians better manage clinical entities such as posterior epistaxis, cavernous sinus infections, and perform endoscopic surgery with fewer complications.