• Journal of the Korean Chemical Society
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• v.10 no.2
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• pp.67-75
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• 1966

Four kinds of clays from Sinyewon mine which is located in Chungchoungnam-Do district and two kinds of Japanese clays (Gairome, Kibushi) were selected and studied on the fundamental properties of these clays and those which are refined by the elutriation method. Chemical analysis, grading analysis such as refractoriness, specific gravity, color, fired color and plasticity, particle size distribution, various thermal tests, X-ray diffraction analysis and electron microscopic survey were carried out on these clays. The comparison of domestic clays with Japanese clays was made. 1. In chemical composition and physical properties, these four kinds of Sinyewon clays are almost similar to each other and also to Gairome and Kibushi clays. In refractoriness, Gairome and Kibushi clays have relatively high value such as SK 34 and 35, while Sinyewon clays have the value of about SK 32. Especially Sinyewon clay B has the low refractoriness (SK 18) and plasticity. Refined clays have the tendency of somewhat higher value than crude ones in refractoriness. 2. When burnt up to $900^{\circ}C$, the coefficients of contraction of Sinyewon clays were under 1.5%, Gairome under 1.3%, Kibushi under 3.0%. Only Sinyewon clay B showed expansion (1.0%) instead of contraction. 3. X-ray diffraction analysis and electron micrography showed that all of four Sinyewon clays and two Japanese clays are mainly composed of poorly crystallized kaolin, containing small amount of halloysite, sericite and considerable amount of quartz and feldspar. Sinyewon clay B contains especially large amount of quartz and feldspar. In general, it has been found out that the refined clays were free from large amount of iron oxide, quartz and feldspar.

• Journal of the Korean Ceramic Society
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• v.33 no.3
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• pp.277-284
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• 1996

The water test results indicated that the impurities had detrimetal effect on the wear resistance of silicon nitride and the effects were getting severe as the temperature increased. Especially when Ca existed as an impurity the detrimental effects was the most severe. These results were resulted from the fact that impurities lowered the mechanical properties of the grain boundary phase of silicon nitride. The wear test results of glass/glass-ceramic specimens having a similar composition to the grain boundary phase of silicon nitride revea-led that the specimen containing CaO showed the lowest wear resistance. The existence of Fe and Ca at the grain boundary phase assisted forming a grain boundary phase with relatively low refractoriness. Therefore at a given wear condition the removal of deformed layer would be easier. The results showed that the glass phases could be modified by heat-treatment and this modification improved tribological characteristics of the silicon nitride.

• Journal of the Korean Ceramic Society
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• v.17 no.1
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• pp.13-19
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• 1980

Mineral identifications on halloysite in Hadong-Sancheong area and the halloysite bearing clay ii Yeoju, Yesan and Hampyeong-Muan area are carried out by the method of X-ray diffraction, electron microscopy and DTA. Chemical composition of the above minerals are analyzed by means of X-ray-fluorescence. Refractoriness are also measured by refractoriness tester. A standard diagram for quantitative analysis of halloysite is given.

• Korean Journal of Biological Psychiatry
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• v.8 no.1
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• pp.140-146
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• 2001

In clinical setting, treatment-refractoriness, medication induced tardive dyskinesia and amenorrhea in chronic schizophrenia are frequently problematic. However, there are few guideline solving these problem available to clinicians. The goal of this study was collecting clinical data on clinical effectiveness and predictors of response of switching to olanzapine. We attempted to switch to olanzapine from risperidone and clozapine in chronic 31(risperidone 17, clozapine 14) schizophrenia and schizoaffective disorder patients suffering from sustained symptoms, weekly blood monitoring, medication induced tardive dyskinesia and amenorrhea. Previous antipsychotics dosage was gradually decreased for 2 or 3weeks, at the same time olanzapine dosage was gradually increased. At baseline, after 1 week, after 2 weeks and after 4 weeks we checked Brief Psychiatric Rating Scale, Clinical Global Impression Scale, Sympson-Angus Rating Scale, Barnes Akathisia Rating Scale and followed up after 12 months. Successful switch after 4 weeks was achieved in 25 patients(clozapine 9(64.2%), risperidone 16(94.1%)). Overall, mean BPRS and CGI scores increased significantly. Successful maintenance after 12 months was achieved in 17 patients(clozapine 5(35.7%), risperidone 12(70.5%)). Overall, mean BPRS and CGI scores increased significantly too. Switching to olanzapine from other atypical antipsychotics is recommendable in chronic schizophrenia with treatment refractoriness and drug induced side effect.

• Molecules and Cells
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• v.39 no.7
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• pp.573-579
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• 2016

During copulation, male Drosophila transfers Sex Peptide (SP) to females where it acts on internal sensory neurons expressing pickpocket (ppk). These neurons induce a post-mating response (PMR) that includes elevated egg-laying and refractoriness to re-mating. Exactly how ppk neurons regulate the different aspects of the PMR, however, remains unclear. Here, we identify a small subset of the ppk neurons which requires expression of a pre-mRNA splicing factor CG3542 for egg-laying, but not refractoriness to mating. We identify two CG3542-ppk expressing neurons that innervate the upper oviduct and appear to be responsible for normal egg-laying. Our results suggest specific subsets of the ppk neurons are responsible for each PMR component.

• Journal of the Korean Ceramic Society
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• v.18 no.4
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• pp.229-236
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• 1981

This study deals with the high temperature (600-135$0^{\circ}C$) properties of Kaolin-Phosphate-Water systems. Phosphoric acid, mono aluminum phosphate, mono ammonium phosphate, the mixture of phosphoric acid and mono aluminum phosphate, and the mixture of phosphoric acid and mono ammonium phosphate were used to characterize the M.O.R of the systems with to quantity of phosphates and firing temperature. Firing shrinkage, creeptest, DTA, TGA, and X-ray diffraction patterns were also measured in order to investigate the factors of strengthening. The resules of the experiments are as follows: 1. Linear shrinkage of kaolin-phosphate systems become larger as the firing temperature rise, and generally in the firing temperature of $600^{\circ}C$ and 100$0^{\circ}C$ the test pieces with phosphate binder show larger then Kaolin-Water system in linear shrinkage and reversed trends were found at 120$0^{\circ}C$ and 135$0^{\circ}C$. 2. Cold M.O.R. of kaolin-phosphate systems show higher trends in strength as the firing temperature rise. Comparing M.O.R. of test pieces after firing at 135$0^{\circ}C$, the mixture of phosphoric acid-mono aluminum phosphate, and phosphoric acid mono ammonium phosphate systems show higher strength than kaolin-mono aluminum phosphate system which widely used, and it shows highest strength when the mole ratio of phosphoric acid and mono ammonium phosphate is 1:1 among the test pieces of kaolin-phosphate systems. 3. The refractoriness of kaolin-phosphate systems are more deteriorated than Kaolin-Water system, and generally, the more addition of phosphate, the lower the refractoriness, however in the range of 4-8% phosphate addition, the difference of the fusion temperature is about 7$0^{\circ}C$. 4. The test pieces of T1 and T2 in creep test were same or even higher than kaolin-water system when 6% of phosphoric acid-mono ammonium phosphate was added to kaolin. 5. In case where the phosphoric acid-mono ammonium phosphate was added to kaolin in mole ratio 1:1 the cold M.O.R., after firing at 135$0^{\circ}C$, refractoriness and $T_2$ in creep test show better results than kaolin-mono-aluminum phosphate system which is widely used. 6. Phosphoric acid and mono ammonium phosphate react with kaolin in temperature over 100$0^{\circ}C$, and it forms aluminum phosphate.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.7 no.1
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• pp.78-82
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• 2004

Henoch-$Sch{\ddot{o}}nlein$ purpura (HSP) is a vasculitis of the small vessels in skin, joints, gastrointestinal (GI) tract and kidney. GI symptoms occur in up to 85% of patients and may lead to severe problems such as intussusception, obstruction, and perforation. GI symptoms may not be easily controlled, showing refractoriness to the conventional corticosteroid therapy. Although GI involvements of HSP are acute, and self-limited in most instances, they may cause fatal results in some unusual cases. In such conditions all the possible therapeutic modalities should be considered. We report two cases of severe small bowel involvement of HSP. One case presented with severe abdominal pain showing refractoriness to corticosteroid, but improved with IV immunoglobulin therapy. In the second case, HSP with transmural infarction in the small bowel could be cured with surgical intervention.

• Journal of the Korean Ceramic Society
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• v.31 no.3
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• pp.275-281
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• 1994

Mullite ceramics have recently been utilized as ceramic gas filters for high-temperature treatment of solid wastes due to their low thermal expansion coefficient and high refractoriness under load. In this experiment, mechanical, thermal and microstructural properties of porous mullite ceramics, which were used as carriers and high-temperature gas filters in food industry, were investigated as a function of starting raw materials. Porous mullite ceramics showed different microstructures depending on their starting materials. The specimen M2 had excellent resistance to thermal spalling and high mechanical strength. The average pore size varied from 0.3 ${\mu}{\textrm}{m}$ to 16.6 ${\mu}{\textrm}{m}$, and porous mullite ceramics fabricated by thermal decomposition of Al(OH)3 had very large pores and broad distribution of pore size.

• Journal of the Korean Ceramic Society
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• v.11 no.1
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• pp.19-22
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• 1974

The andalusite that can be found in mica shist near YunChun deposits were studied by means of an optical microscope, X-ray diffraction, thermal analysis of DTA and TGA, chemical analysis and refractoriness test to find out an appropriate method of concentration and purification for the utilization as a raw material of high alumina refractories, with the results: 1. The andalusite are has chiefly contained andalusite, muscovite and biotitei in addition to small amounts of chlorite, kyanite, disapore, quartz, alumandite adn pyrite, which vary from sample to sample. 2. Most of andalusite have occurred as light-red colored columns which are estimated to be an average of 4 by 0.5m/m in length. 3. Samples of andalusite which were dressed by cobbing and hand picking in the deposits have contained an average of 42% andalusite.

• Journal of the Korean Ceramic Society
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• v.12 no.3
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• pp.3-7
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• 1975

The usefulness of the domestic shale contained chiastolite as additive were investigated. Crude mixed minerals were separated into shale and chiastolite. Refractory body added simple component or multiple components as additives was obtained when firing at 125$0^{\circ}C$ for each body. Compressive strength, refractories, apparent sp. gr., water absorption, corrosion test by slag, hot linear expansion were measured and X-ray diffraction analysis was observed. As the result of study, refractory body contained separated minerals as additives showed slightly increasing in refractoriness, lowering in sintering effect, the excellent effect for corrosion resistance by acidic slag. With more containing separated minerals, hot linear expansion for the body can be decreased.