• Korean Journal of Crystallography
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• v.9 no.2
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• pp.92-95
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• 1998

The structure of bis(isocyanto-N)nickel (II) complex, [Ni(L)(NCO)2] (L: 2,5,9,12-tetramethyl-1,4,8,11-tetraazacyclotetradecane), is centrosymmetric and the central nickel has an axially elongated octahedral geometry with two nitrogen atoms of the isocyanate ligand.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.5 no.4
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• pp.121-128
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• 1996

In order to examine spindle deformation characteristics that affects the performance of dynmic cutting acuracy due to tool weight variation in a experimental spindle. thermal deformation value of operrative spindle by the axial displacement and the radial run out was measured according to the rise of spindle temperature through the laps of operation time and the change of rotational speed under the tool weight variation. A qualitative summary is as follows ; 1) The results show that the tool weight affcets the spindle temperature variation in a experimental spindle. 2) Radial run out and axial displacement was measured according to the rise of the spindle temperature and the performance of dynamic cutting accuracy was affected by the tool weight variation. 3) Axial displacement is 1.3 times larger than the radial run out in a experimental spindle conditions. 4) Axial displacement is continuously elongated when the tool weight is repeatly exchanged since the spindle themal deformaion, however, when the same tool weight is used. the displacement is still constant.

• Journal of the Korea Safety Management & Science
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• v.4 no.2
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• pp.223-235
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• 2002

This paper presents some indirect physical evidences indicating that reduced friction occurs in an economical cryogenic machining process, in which LN2 is applied selectively in well-controlled jets to the localized cutting zone. These evidences include cutting force components, tool wear rate and chip morphology. LN2 reduced the tool wear rate to a great extent and elongated the tool life up to four times compared to emulsion cooling. The friction reduction was further reflected in larger shear angle and less secondary deformation in the chip microstructures. This study also found that the effectiveness of LN2 lubrication depends on the approach how LN2 is applied.

• Journal of Plant Biology
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• v.14 no.2
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• pp.7-10
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• 1971

Haploid cell obta-ined from microspores of Solanum nigrum were cultured on two kinds of medium, "Callus-inducing medium" and "Differentiation medium", in order to conduct histological studies of callus and examine differentiation of plantlets. On the callus-inducing medium the calli grew rapidly. The bulk of callus mass was light brown colored "Wet callus" covered on the surface with thin layers of rough and gleaming "White callus". The wet callus was consisted of parenchyma and meristematic tissues, while the white callus had no meristematic tissues. Large parenchyma cells, by successive divisions, became multicellular or poly nucleate cells which developed later to be meristematic tissues. The calli embedded on the differentiation medium quickly turned to dark brown color. Plantlets, however, came out later from these blackened callus mass. In the callus sectioned about ten weeks after imbedding on the differentiation medium, radially elongated tissue, concentric tissue, epidermis, tracheid-like structure, and plant jprimordia were observed.ure, and plant jprimordia were observed.

• Journal of Plant Biology
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• v.36 no.1
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• pp.29-34
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• 1993

Observation was made on early ontogeny of vascular cambium in the cotyledonary node of Pinus koraiensis seedling in order to clarify the cambial ontogeny of the node which was hardly elongated. In transverse view, the derivatives by the early periclinal divisions at the outer region of the procambial strands differentiated to protophloem with establishing a certain degree of radial seriations. Later, some cells in the central region of the procambial strands begin divide periclinally, eventually the cells, differentiate gradually to the vascular cambium. In tangential view, early procambium is consisted of homogeneous short cells with transverse end walls which are tansformed into the long cells and short cells gradually. The long cells continue intrusive growth and the short cells repeat transverse division. Finally, the long and short cells differentiated to cambial fusiform initials and ray initials respectively. In tangential section, the differentiation pattern of cambial initials resembles that of the stem of Ginkgo biloba. But in transverse view, the characteristics in the origin of vascular cambium of the cotyledonary node resembles that of root. The vascular cambium in cotyledonary node is completed after eleven prophylls were formed.

• Animal cells and systems
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• v.15 no.1
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• pp.63-72
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• 2011

A new species belonging to the genus Cyclopinoides Lindberg, 1953 (Cyclopinidae) is described from three beaches in Korea and Japan, as the first record of the genus from the Pacific. Among five species currently recognized in the genus, the new species resembles C. schulzi Herbst, 1964 from the Red Sea in sharing the character combination of 20-segmented antennule and stumpy caudal rami. However, C. orientalis n. sp. differs from it by relatively longer caudal rami (2.5-2.8 times as long as wide in female and about 1.6-1.8 times in male, while less than 2 times in female and about 1.3 times in male of C. schulzi), and by the transformation of an outer distal spine to a slender seta on the distal exopodal segment of leg 4. Moreover, C. orientalis n. sp. is discernible from C. schulzi in having a pyriform copulatory tube (against elongated tubular style in C. schulzi). A key to the species hitherto known in the genus is provided.

• Journal of the Korean Ceramic Society
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• v.44 no.7
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• pp.354-357
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• 2007

The nitriding and post-sintering behavior of silicon powder compact containing sintering additives of 2.3 wt% and 7 wt% were investigated in this study. Regardless of the liquid phase content, elongated large grains of a typical morphology evolved in the post-sintered specimens. Phase analysis revealed a complete phase transformation into ${\beta}-Si_3N_4$ in both porous systems. Oxynitride second phases (mellilite) precipitated in the latter, while those were free in the former containing less amount of liquid phase. The post-sintering condition that yielded a favorable microstructure for a filter application was achieved when the specimens were soaked at $1800^{\circ}C$ for 2 h. It was found that the thermal conductivity of porous $Si_3N_4$ ceramics is dominated by the porosity more than this factor is influenced by the addition of $Al_2O_3$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.05a
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• pp.59-62
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• 1994

Tact Electrical conductivity. optical absorption spectra of poly(p-phenylene vinylene) and their dependence on stretching are discussed in detail. The conductivity in the parallel direction to the stretching is higher over one order in magnitude than that in the perpendicular direction to the stretching is higher over one order in magnitude than that in the perpendicular direction to the stretching. The photocurrent spectrum for the ligh polarized parallel to the chain direction is much enhanced in lower photon energy compared with that for the light polarized perpendicular to that direction. The result may be originated in the difference of energies which is needed to photogenerate carriers wi th the light polarized parallel and perpendicular to the chain stretched direction.

• The Korean Journal of Pain
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• v.26 no.2
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• pp.169-172
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• 2013

Eagle's syndrome is a disease without a clear lesion that is associated with repeated episodes of pharyngalgia, odynophagia, the sensation of a foreign body in the pharynx, tinnitus, and otalgia in which patients displaying these types of symptoms must be given a differential diagnosis. It is known to be characterized by styloid process elongation or increasing compression to adjacent anatomical structures through stylohyoid ligament calcification. In serious cases, continuous pressure to the carotid artery can lead to a stroke. Diagnosis is confirmed through clinical symptoms, radiological findings, and physical examinations. The most common type of treatment consists of a surgical excision of elongated styloid process. Nonetheless, this study presents a case of treating Eagle's syndrome with conservative management.

• The Korean Journal of Cytopathology
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• v.4 no.1
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• pp.70-73
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• 1993

Giant cell tumor(GCT) occurs very unusually in the rib(less than 1% of GCT). We present the cytologic features of GCT of the rib. It showed multiple cellular clusters composed of characteristic, benign looking osteoclast-like multinucleated giant cells and fibroblast-like mononuclear cells. The multinucleated giant cells contained numerous nuclei (average, 30 to 40 per cell, which were closely packed. The nuclei in giant cells were remarkably uniform and round to oval. The mononuclear, neoplastic stromal cells were elongated and spindle-shaped. There was no cytologically malignant portion in the tumor.