• Title/Summary/Keyword: Ring-expansion

Search Result 112, Processing Time 0.034 seconds

Cases of Tracheopathia Osteochondroplastica in German shepherd (German shepherd에서 발생한 기관 골.연골형성증)

  • 한정희;김준기;서강문
    • Journal of Veterinary Clinics
    • /
    • v.17 no.1
    • /
    • pp.129-133
    • /
    • 2000
  • Based on pathological findings, 5 German shepherds, revealed a mean age of 7.6 years, showing no clinical signs were diagnosed as tracheopathia osteochondroplastica(TOC). Grossly, multiple small-sizecd nodules, appeared as cobble-stones, on the cartilage rings situated in the anterior trachea and the mucosal surface of the epiglottis were showed. Numerous tiny nodules were scattered on the pleural surface of the lung. The vascular walls of the heart were irregular and coarse apearance with calcification. Histopathologically, nodules in the trachea represented an irregular expansion of the underlying tracheal ring with protrusion into the submucosa and consisted of proliferated and calcified cartilage and bone with marrow spaces containing numbers of hematopoietic cells. Pulmonary calcinosis and calcification of the vascular walls of the heart were observed. Our observations suggested that TOC arises form eccondroses and exostoses of the tracheal cartilage rings.

  • PDF

A Study on Removing the Magnetic Impurity in a Power Plant Line (발전소 배관 내부유체의 자성 이물질 제거에 관한 연구)

  • Choi, Yoon-Hwan;Kim, Oh-Kuen;Suh, Yong-Kweon
    • The KSFM Journal of Fluid Machinery
    • /
    • v.6 no.4 s.21
    • /
    • pp.45-49
    • /
    • 2003
  • This work focuses on eliminating tiny particles from the coolant in a nuclear pipe line by using a permanent magnet on the exterior surface of the pipe. This method have some merits compared with the currently applied methods and is expected to be applied to most of the pipe lines in the nuclear plant. For instance in this method, a ring is attacked to the exterior surface of the pipe, so that it does not affect the inflows directly. Further, the cost needed in the initial build-up of the facility is low.

Rearrangement of Benzyl-type Radical in Corona Discharge of 2,6-Dichlorotoluene

  • Yoon, Young-Wook;Lee, Seung-Woon;Lee, Sang-Kuk
    • Bulletin of the Korean Chemical Society
    • /
    • v.31 no.9
    • /
    • pp.2479-2482
    • /
    • 2010
  • Using a pinhole-type glass nozzle equipped for a corona-excited supersonic expansion (CESE), precursor 2,6-dichlorotoluene seeded in a large amount of inert carrier gas helium was discharged to produce jet-cooled but electronically excited benzyl-type radicals. The visible vibronic emission spectrum was recorded with a long-path monochromator to observe vibronic bands in the $D_1{\rightarrow}D_0$ electronic transition of benzyl-type radicals. The spectral analysis revealed the generation of not only the 2,6-dichlorobenzyl radical as a typical product, but also the o-chlorobenzyl radical as an unexpected species, which indicates the possible molecular rearrangement in eliminating a chlorine atom from the benzene ring. A possible mechanism is proposed for the formation of the o-chlorobenzyl radical from the precurs or in the gas phase.

A STUDY ON ELASTO-PLASTIC ANALYSIS OF SPHERICAL SHELL BY RIGID ELEMENT METHOD(I) - Theoretical Consideration on Elasto-Plastic Analysis of Spherical Shell - (강체요소법에 의한 구형쉘의 탄소성해석에 관한 연구( I ) - 구형쉘의 탄소성 해석에 관한 이론적 고찰 -)

  • 권택진;한상율;서삼열;박강근
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 1988.10a
    • /
    • pp.18-23
    • /
    • 1988
  • This study on the elasto-plastic analysis of spherical shell by rigia element method is classified into two parts : (1) theoretical consideration on elasto-plastic analysis of spherical shell, (2) elastic and elasto-plastic analysis of spherical shell with the open stiff ring. In 1982, Y. Tsuboi proposed the new analytical method which is called the rigid element method, for analyzing the elasto-plastic behavior of wall-type precast concrete structures by applying the concepts of rigid bodies-sprins model (i.e., when structures reach their ultimate state of leading, they may be yield, collapsed ana crushed into pieces, and each part or piece of structures mar move like a rigid body.). In this paper, for improvement and expansion this rigid element method, it is proposed the adaptation equation of rectangular-shaped spherical element and rectangular-shaped spherical bending element developed by present authors, and the analytical procedure for the elastic and the elasto-plastic increment method of structures.

  • PDF

Study on Slice Sensitivity Profile and Reconstruction Resolution on Helical CT System (Helical CT 시스템에 있어 Slice Sensitivity Profile과 Reconstruction Resolution에 관한 연구)

  • Yoon, Han-Sik
    • Journal of radiological science and technology
    • /
    • v.20 no.1
    • /
    • pp.15-20
    • /
    • 1997
  • Unlike conventional CT scan, the helical CT scan uses continuous rotating CT equipment with a slip ring to move the patient's coach at a constant speed while continuously scanning. Slice sensitivity profiles in the Z-position(SSPz) using the conventional X-ray CT have a shape similiar to a rectangular wave, which slightly spreads out into plains below the mountain. However, in the helical CT, with an expansion of the base, the rectangular shape collapses and a mouatain-like shape can be seen. We need to investigate the fellowing factors in helical CT scanning;the ability to scan along the axis of the body, effective slice width, slice shape and the precision of coach velocity, Helical scanning with sprial X-ray track is different from the conventional scanning in terms of the principle of image reconstruction performed. We believe that the problems in helical scanning can be solved by understanding new the special parameters such as the bed moving speed and the interval of image reconstruction.

  • PDF

Effect of 9-Amino-1, 2, 3, 4-tetrahydroacridine on $CCl_4$-Induced Liver Injury in Rats (흰쥐의 사염화탄소로 유도된 간손상에 미치는 9-Amino-1, 2, 3, 4-tetrahydroacridine의 영향)

  • Shin Hea-Soon;Cho Eun-Jung
    • Environmental Analysis Health and Toxicology
    • /
    • v.21 no.1 s.52
    • /
    • pp.87-92
    • /
    • 2006
  • This study was done to investigate the protective effect of novel 9-amino-1, 2, 3, 4-tetrahydroacridine derivatives on the hepatoprotective effect intoxicated rats induced by carbon tetrachloride ($CCl_4$). A series of currently derivatives of 9-amino-1, 2, 3, 4-tetrahydroacridine have been prepared through the alkly substitution or the ring expansion for the treatment of the Alzheimer's disease. The activities of aminotransferase (aspartate and alanine) and contents of alkaline phosphatase, triglyceride and glutathione S-transferase in 9-amino-1, 2, 3, 4-tetrahydroacridine derivatives pretreated rats were significantly decreased compared to the only carbon tetrachloride treated rats but the contents of cholesterol were increased compared to the only $CCl_4$ treated rats. The result indicated that 9-amino-1, 2, 3, 4-tetrahydroacridine derivatives showed hepatoprotective effect in $CCl_4$ treated rats.

Inhibitory Effects of of Tacrine Derivatives on Activity of Prostanoids Biosynthesis Prostaglandin Biosynthesis: A Potential Use for Degenerative Brain Disease Treatment (퇴행성 뇌질환 치료제 Tacrine 유도체의 프로스타글란딘 생합성 억제효과)

  • Shin Hea Soon
    • YAKHAK HOEJI
    • /
    • v.49 no.1
    • /
    • pp.103-108
    • /
    • 2005
  • Tacrine analogues for degenerative brain disease treatments have been designed. A series of diazaanthrine derivatives as novel analogues of tacrine has been prepared through the alkyl substitution and the ring expansion. They were expected to retain anti-inflammatory activity by inhibition of prostaglandin production with reduction of side effect as the selective prostaglandin synthase inhibitor. Prostaglandin synthase expression is associated with the deposition of beta-amyloid protein in neuritic plaques in brain inflammation. Therefore selective prostaglandin synthase blockade is important for the prevention and treatment of alzheimer's disease. To evaluate inhibitory effect of prostaglandin synthase, synthetic tacrine derivatives were screened with accumulation of prostaglandin biosynthesis by lipopolysaccharide in aspirin-treated murine macrophage cell. Most of synthetic compounds have shown significant prostaglandin synthase activities in vitro screening with $84.3{\sim}33.6\%$ inhibition of the prostaglandin $E_2$ production at $10\;{\mu}g/ml$.

Conversion of 1,3-Thiazolidines to Dihydro-1,4-thiazine by Chlorinolysis

  • Lee, Wha-Suk;Mah, He-Duck;Nam, Kee-Dal;Kang, Soon-Bang
    • Bulletin of the Korean Chemical Society
    • /
    • v.13 no.1
    • /
    • pp.83-87
    • /
    • 1992
  • The ring expansion of 1,3-thiazolidines 4 derived from ${\beta}$-ketoacid derivatives to the corresponding dihydro-1,4-thiazines 1 by using the action of chlorine on 4 has been achieved. In the chlorinolysis unisolable sulfenyl chlorides 5 may be formed from chlorosulfonium ions 11 by ${\beta}$-elimination involving carbonyl activated methylene hydrogens. Addition of sulfenyl chloride to the internal double bond appears to form probable thiiranium ions 14, which in turn gave 1 with loss of acidic proton. Imminium ions 15 could be hydrolyzed easily to give enol 8. As a side reaction, dihydrothiazine that was formed was further chlorinated to produce dichlorides 16 which were rearranged readily to the chloromethyl compounds 10.

RELATIVE CLASS NUMBER ONE PROBLEM OF REAL QUADRATIC FIELDS AND CONTINUED FRACTION OF $\sqrt{m}$ WITH PERIOD 6

  • Lee, Jun Ho
    • East Asian mathematical journal
    • /
    • v.37 no.5
    • /
    • pp.613-617
    • /
    • 2021
  • Abstract. For a positive square-free integer m, let K = ℚ($\sqrt{m}$) be a real quadratic field. The relative class number Hd(f) of K of discriminant d is the ratio of class numbers 𝒪K and 𝒪f, where 𝒪K is the ring of integers of K and 𝒪f is the order of conductor f given by ℤ + f𝒪K. In 1856, Dirichlet showed that for certain m there exists an infinite number of f such that the relative class number Hd(f) is one. But it remained open as to whether there exists such an f for each m. In this paper, we give a result for existence of real quadratic field ℚ($\sqrt{m}$) with relative class number one where the period of continued fraction expansion of $\sqrt{m}$ is 6.

2-absorbing δ-semiprimary Ideals of Commutative Rings

  • Celikel, Ece Yetkin
    • Kyungpook Mathematical Journal
    • /
    • v.61 no.4
    • /
    • pp.711-725
    • /
    • 2021
  • Let R be a commutative ring with nonzero identity, 𝓘(𝓡) the set of all ideals of R and δ : 𝓘(𝓡) → 𝓘(𝓡) an expansion of ideals of R. In this paper, we introduce the concept of 2-absorbing δ-semiprimary ideals in commutative rings which is an extension of 2-absorbing ideals. A proper ideal I of R is called 2-absorbing δ-semiprimary ideal if whenever a, b, c ∈ R and abc ∈ I, then either ab ∈ δ(I) or bc ∈ δ(I) or ac ∈ δ(I). Many properties and characterizations of 2-absorbing δ-semiprimary ideals are obtained. Furthermore, 2-absorbing δ1-semiprimary avoidance theorem is proved.