• Journal of Korea Foundry Society
• /
• v.38 no.4
• /
• pp.75-81
• /
• 2018

This study examined the effect of the CaMgSn ternary phase on the aging response of the Mg-Sn-Zn alloy. The results revealed that the CaMgSn ternary phase formed in rod-like or needle-like shapes in Mg-3Zn-0.3Ca-xSn (x=1.5, 3, and 5 wt%) alloys and its size decreased as the Sn content increased from 1.5 wt% to 5 wt%. The Mg-3Zn-0.3Ca-5Sn alloy with a relatively fine CaMgSn phase was subjected to solution heat treatment and an aging process. Both the Mg-5Sn-3Zn-0.3Ca and Mg-5Sn-3Zn (base alloy) alloys had similar peak hardness values throughout all aging temperatures but the time-to-peak hardness in the Mg-5Sn-3Zn-0.3Ca alloy was 24-36 hours-earlier than that in the base alloy. Precipitates in the Mg-5Sn-3Zn-0.3Ca alloy were more refined than those in the Mg-5Sn-3Zn alloy and were mostly formed on basal planes. The $Mg_2Sn$ phase formed in either plate-like or rod-like shapes in the Mg-5Sn-3Zn alloy, whereas block-shaped $Mg_2Sn$ particles also formed in the Mg-5Sn-3Zn-0.3Ca alloy.

• Journal of Korea Foundry Society
• /
• v.31 no.5
• /
• pp.284-287
• /
• 2011

Microstructures and tensile properties at ambient and elevated temperatures were studied by substituting RE for Sr in Mg-6%Al-(3-X)%RE-X%Sr alloys (X = 0~3). With increasing Sr content, $Al_4Sr$ phase with lamellar morphology was newly introduced at interdendritic regions, with a gradual extinction of needle-shaped $Al_4RE$. The Mg-6%Al-3%Sr alloy shows dendritic grains and interdendritic eutectic phases containing bulky Mg-Al-Sr and lamellar $Al_4Sr$ with more continuous manner. The substitution of Sr for RE provided higher YS, UTS and creep resistance at $175^{\circ}C$, which indicates that Sr would be more beneficial in tensile properties and creep resistance at elevated temperature than RE for the Mg-Al based casting alloys.

• Journal of Veterinary Clinics
• /
• v.37 no.4
• /
• pp.208-212
• /
• 2020

A 6-year-old castrated male Russian Blue cat was presented for evaluation of dyschezia. Abdominal ultrasound revealed hyperechoic nodules in both kidneys, heterogeneous mass in abdomen, and extensive mesenteric thickening with multiple hypoechoic nodules. Computed tomography showed multiple hypodense lesions in both kidneys and diffuse nodular infiltration around the mesentery. Fine needle aspirates (FNA) acquired under ultrasound guidance from the mesentery consisted of large lymphocytes which have round to irregular nuclei with granular chromatin, prominent nucleoli and a small amount of basophilic cytoplasm. Polymerase chain reaction (PCR) for antigen receptor gene rearrangement result of FNA sample revealed a T-cell malignancy. The cat died from acute renal failure after 1 cycle of modified Madison-Wisconsin L-CHOP protocol. Postmortem examination revealed bilaterally enlarged lumpy-bumpy shaped kidneys. Histopathologic examination showed an infiltration of malignant lymphocytes into the renal parenchyma and mesentery. Immunohistochemical staining of the renal sample displayed a negative expression of CD3, PAX5, MUM-1, and CD79. The clinical features and prognosis of the cat with renal lymphoma with mesenteric lymphomatosis have been described in this report.

• Korean Journal of Materials Research
• /
• v.11 no.2
• /
• pp.115-119
• /
• 2001

The electrical properties of heavily drawn bundled Cu- Nb filamentary microcomposite wires were examined and correlated with the microstructural changes caused by thermomechanical treatments. The cross sectional shape of Nb filaments in wires fabricated by bundling and drawing appear straight or slightly curved. The different shape of Nb filaments is attributed to the break- up and cylinderization of Nb filaments during the bundling process at high temperatures. The resistivity of Cu-Nb microcomposites is predominantly controlled by electron scattering at Cu-Nb interfaces. The decrease of the conductivity below the annealing temperature of $400^{\circ}C$ is due to the increasing contribution of the scattering associated with coherency strains of needle- shaped precipitates. The slight decrease of the resistivity ratio (${\rho}_{295K}/{\rho}_{75K}$) is also due to the precipitation of Nb atoms. The increase in conductivity in Cu-Nb microcomposites at an annealing temperature of 50$0^{\circ}C$ is due to the coarsening and spheroidization of Nb filaments.

• The Journal of Pediatrics of Korean Medicine
• /
• v.35 no.3
• /
• pp.53-66
• /
• 2021

Objective The purpose of this study is to evaluate whether herbal bath shortens the duration of pediatric fever. Methods Databases, such as Medline, EMBASE, Cochrane library, OASIS, KISS, KMBASE, CNKI, Wanfang Med Online were used to search randomized controlled trials. Those trials that included children younger than 18-year-old were evaluated for the clinical efficacy of herbal bath in fever by analyzing 'body temperature (BT) drop start time' and 'time to return to normal BT'. Results 12 studies or 1306 participants were analyzed in the study. When applying herbal bath in combination with the controlled treatment, 'BT drop start time' was decreased by 0.11 hours, and 'time to return to normal BT' was decreased by 10.94 hours compared to the controlled group. When comparing herbal bath with tepid bath, 'time to return to normal BT' was reduced by 8.19 hours in herbal bath group. In regards to safety, 3 studies out of 12 studies mentioned about its adverse events: 2 studies did not have any adverse events, and a minor needle-shaped bleeding had occurred in one of the studies. Conclusion Use of herbal bath as a treatment of fever in children was associated with shortened duration of fever. However, cautious interpretation is necessary due to its limited safety data.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.16 no.4
• /
• pp.479-490
• /
• 2018

The granite melting concept, which was suggested by Gibb's group for the closing of a deep borehole, was experimentally checked for KURT granite. The granite melting experiments were performed in two pressure conditions of atmospheric melting with certain inorganic additives and high pressure melting formed by water vaporization. The results of atmospheric tests showed that KURT granite started to melt at a lower temperature of $1,000^{\circ}C$ with NaOH addition and that needle shaped crystals were formed around partially melted crystals. In high pressure tests, vapor pressure was increased by adding water with maximum pressure of about 400 bars. KURT granite was partially melted at $1,000^{\circ}C$ when vapor pressure was low. However, it was not melted at vapor pressures higher than 200 bars. Therefore, it was determined that high pressure with a small amount of water vapor more effectively decreased the melting point of granite. Meanwhile, high temperature and high pressure vapor caused severe corrosion of the reactor wall.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.4 no.2
• /
• pp.148-156
• /
• 1994

Three composition in the system of $YO_{1.5}-BaO-CuO$ were grown using a cold crucible (skull) melting technique with a 50 kW R.F. induction generator operating at 4 MHz as the power source. The starting materials were prepared by conventional ceramic powder processing methods, loaded into the skull, and melted at about $1200^{\circ}C$. For this study, compositions near the $YBa_2Cu_3O_X$ region were selected. The growth rates used ranged from 4 cm/hr to 0.25 cm/hr. The relation between the microstructures and the starting composition of each ingot was determined using metallograph, X-ray diffraction, and energy dispersive X-ray analysis. Both $YBa_2Cu_3O_X$ and $Y_2BaCuO_5$ needle-shaped crystals, aligned with the growth direction, were formed in the $CuO-BaCuO_2$ eutectic matrix of the $YBa_2Cu_7O_x and YBa_5Cu_{11}O_x$ ingot.

• Clinical Endoscopy
• /
• v.56 no.4
• /
• pp.490-498
• /
• 2023

Background/Aims: Post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP) is the most common and serious complication of endoscopic retrograde cholangiopancreatography. To prevent this event, a unique precutting method, termed opening window fistulotomy, was performed in patients with a large infundibulum as the primary procedure for biliary cannulation, whereby a suprapapillary laid-down H-shaped incision was made without touching the orifice. This study aimed to assess the safety and feasibility of this novel technique. Methods: One hundred and ten patients were prospectively enrolled in this study. Patients with a papillary roof size ≥10 mm underwent opening window fistulotomy for primary biliary access. In addition, the incidence of complications and success rate of biliary cannulation were evaluated. Results: The median size of the papillary roof was 6 mm (range, 3-20 mm). Opening window fistulotomy was performed in 30 patients (27.3%), none of whom displayed PEP. Duodenal perforation was recorded in one patient (3.3%), which was resolved by conservative treatment. The cannulation rate was high (96.7%, 29/30 patients). The median duration of biliary access was 8 minutes (range, 3-15 minutes). Conclusions: Opening window fistulotomy demonstrated its feasibility for primary biliary access by achieving great safety with no PEP complications and a high success rate for biliary cannulation.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.21 no.5
• /
• pp.117-124
• /
• 2017

In this study, to evaluate the setting time, compressive strength and drying shrinkage of ordinary Portland cement and Portland blast-furnace slag cement mortar with 0, 10, 20, 30 wt.% alpha-calcium sulfate hemihydrate. As a results, as the replacement ratio of alpha-calcium sulfate hemihydrate increased, the initial setting time of ordinary Portland cement and Portland blast-furnace slag cement mortar was faster. In addition, the compressive strength decreased with increasing replacement ratio of alpha-calcium sulfate hemihydrate in both ordinary Portland cement mortar and Portland blast-furnace slag cement mortar. The strength development of Portland blast-furnace slag cement mortar with alpha-calcium sulfate hemihydrate was effective than that of ordinary Portland cement mortar. On the other hand, in the case of the mortar with alpha-calcium sulfate hemihydrate, it was confirmed that shrinkage deformation was reduced at the early age by growth pressure of needle-shaped ettringite crystals produced by incorporation of alpha-calcium sulfate hemihydrate. However, the effect of inhibiting shrinkage deformation of mortar with alpha-calcium sulfate hemihydrate was not significant as the age passed. Therefore, it is considered that the alpha-calcium sulfate hemihydrate is useful as a construction material.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.12 no.5
• /
• pp.240-246
• /
• 2002

$TiO_2$ films on soda-lime-silica glasses were prepared by spin coating-pyrolysis process using titanium naphthenate as a starting material. As-deposited films were pyrolyzed at $500^{\circ}C$ for 10 min in air and annealed at 500, 550 and $600^{\circ}C$ for 30 min in air. Crystallinity of the film was investigated by X-ray diffraction analysis. A field emission-scanning electron microscope and an atomic force microscope were used for characterizing the surface morphology and the surface roughness of the film. After annealing at 550 and $600^{\circ}C$, the X-ray diffraction patterns consist of only anatase peak. Films annealed at 500 and $550^{\circ}C$ exhibited flat surfaces. While with the increase in annealing temperature to $600^{\circ}C$, the $TiO_2$ film showed abnormal growth of three-dimensional needle-shaped grains. For all samples, high transmittance, above 90 % at 500 nm, was obtained at visible range. To investigate photocatalytic properties, IR absorbance associated with the C-H stretching vibrations of a thin solution-cast film of stearic acid under 365 nm (2.4 mW/$\textrm{cm}^2$) UV irradiation was estimated.