• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.30 no.6
• /
• pp.220-225
• /
• 2020

Gallium oxide nano-powder, the key starting material for IGZO target, is fabricated by gas phase synthesis using a new apparatus consist of reaction, transportation, and collection parts. As a result of gallium metal evaporation above 1150℃, Ga2O3 nano-powders, are successfully synthesized. The SEM images of the synthesized powders displace the spherical shaped powders without severe agglomeration. X-ray diffraction and PSA analysis show that the higher temperature at the reaction part results in the better crystallinity and larger powder size of the synthesized Ga2O3. To see the applicability to IGZO target, Ga2O3 nano-powders synthesized at 1250℃ are mixed with indium oxide and zinc oxide (In2O3 : Ga2O3 : ZnO = 1 : 1 : 1), and then sintered at 1400~1500℃. The highest sintered density of 5.83 g/㎤ (= 91 % of relative density) is achieved when sintered at 1450℃, showing better sinterability compared to the commercially available Ga2O3 powder, which has 5.61 g/㎤ of sintered density at the same condition.

• Journal of Korea Association of Health Promotion
• /
• v.2 no.3
• /
• pp.73-96
• /
• 2004

Along with a development of medical technology, a variety of tests, such as laboratory tests, x-ray and endoscopies are being used in health screening tests. As the tests determine the quality of health screening, test items and methods should be carefully selected. This study was to get hold of the test items of major health screening programs in Korea Most of the health screening programmes focused upon detection of risk factors and diagnosis of life - style related diseases (diabetes, hypertension, cardiovascular diseases, hypercholesterolemia, overweight, drinking, smoking, cerebrovascular diseases, osteoporosis) ,cancers (stomach, cervix, lung, breast, liver, colon, prostate, ovary, pancreas, thyroid, esophagus) , infectious diseases (hepatitis, tuberculosis, sexually-transmitted diseases, parasites) , chronic obstructive respiratory diseases, chronic renal diseases (bacteriuria hematuria, proteinuria) , anemia, glaucoma, hearing loss, Alzheimer disease, stress, early psychiatric diseases. The health screening tests were basic physical examination, basic laboratory tests (CBC, urinalysis, liver function tests, lipid tests, glucose, HbAlc, uric acid, electrolytes, serological tests (HBsAg, HBs-Ab, HCV-Ab, HIV-Ab, VDRL) EKG, x-ray (chest PA, CT) , endoscopy (gastroscopy, colonoscopy) , sonography(abdomen, thyroid, pelvis, breast) ,cytology (cervix) , bone density, tumor markets (NMP22, alpha-FP, CEA, CA-19-9, CA12S, PSA) and eye tests. Advanced technologies, like CT, PET, MRI, MRT/Angio, molecular testings) were widely used in hospital health screening programmes .In summary, a variety of tests were utilized in health screening in Korea. Those tests were utilized by stages or according to sex and age in most of health screening programmes, however a few program used tests to excess disregarding health screening subjects.

• Journal of Korea Association of Health Promotion
• /
• v.2 no.1
• /
• pp.9-25
• /
• 2004

Along with a development of medical technology, a variety of tests, such as laboratory tests, x-ray and endoscopies are being used in health screening tests. As the tests determine the quality of health screening, test items of major health screening program in Korea. Most, of the health screening programmes focused upon detection of risk factors and diagnosis of life-style related diseases(diabetes, hypertension, cardiovascular diseases, hypercholesterolemia, overweight, drinking, smoking, cerebrovascular diseases, osteoporosis), cancers(stomach, cervix, lung, breast, liver, colon, prostate, ovary, pancreas, thyroid, esophagus), infections diseases(hepatitis, tuberculosis, sexually-transmitted diseases, parasites), chronic obstructive respiratory diseases, chronic renal diseases(bacteriuria, hematuria, proteinuria), anemia, glaucoma, hearing loss, Alzheimer disease, stress and earlypsychiatric diseases. The health screening tests were basic physical examination, basic laboratory tests( CBC, urinalysis, liver function tests, lipid tests, glucose, HbA1c, uric acid, electrolytes, serological tests(HBsAg, HBs-Ab, HCV-Ab, HIV-Ab, VDRL) EKG, x-ray(chest PA, CT) endoscopy(gastroscopy, colonoscopy), sonography (abdomen, thyroid, pelvis, breast), cytology(cervix), bone density, tumor markers(NMP22, alpha-FP, CEA, CA-19-9, CA125, PSA and eye tests. Advanced technologies, like CT, PET, MRI, MRI/Angio, molecular testing were widly used in hospital based health screening programmes. In summary, a variety of tests were untilized in health screening in Korea. Those tests were utilized by stages or according to sex and age in most of health screening programmes, however a few programs used tests excessvely disregarding health screening subjects.

• Korean journal of applied entomology
• /
• v.19 no.4 s.45
• /
• pp.228-233
• /
• 1980

The infection rate of soybean black root rot disease caused by Calonectria crotalariae was about $14\%$. The isolated fungi from the infected soybean roots and stems were Calonectria crotalariae, Fusarium solani, F. roseum, Phomopsis sojae, Pythium aphanidermatum, Rhizoctonia solani and Macrophomina sp. Among them, C. crotalariae was the most virulent pathogen under the laboratory conditions. Mycelial growth and microsclerotial formation were good on PSA containing 1000cc of water, 100g of potato and 20g of sugar. Mycelial growth, sporulation and microsclerotial formation were good on sterilized root. Perithecial formation was better in the dark condition than in the light. Survival of macroconidia was not available between $0\~25\%$ soil water content. Microsclerotia and mycelium in infected plant debris were survived for 4 months at to $8\%\;50\%$ soil water content. The plant height, when inoculated with $1.2\%$ inoculum density, reached approximately half of uninoculated plants. Disease severity was much higher at nonsterilized soil than completely sterilized soil. It was determined that the host range of this pathogen includes soybean, peanut, green bean and red bean.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.27 no.1
• /
• pp.57-63
• /
• 2017

High-purity ${\beta}-SiC$ powders for SiC single-crystal growth were synthesized by direct carbonization. The use of high-purity raw materials to improve the quality of a SiC single crystal is important. To grow SiC single crystals by the PVT method, both the particle size and the packing density of the SiC powder are crucial factors that determine the sublimation rate. In this study, we tried to produce high-purity ${\beta}-SiC$ powder with large particle sizes and containing low silicon by introducing a milling step during the direct carbonization process. Controlled heating improved the purity of the ${\beta}-SiC$ powders to more than 99 % and increased the particle size to as much as ${\sim}100{\mu}m$. The ${\beta}-SiC$ powders were characterized by SEM, XRD, PSA, and chemical analysis to assess their purity. Then, we conducted single-crystal growth experiments, and the grown 4H-SiC crystals showed high structural perfection with a FWHM of about 25-48 arcsec.

• Journal of Korea Association of Health Promotion
• /
• v.2 no.2
• /
• pp.215-230
• /
• 2004

Along with a development of medical technology, a variety of tests, such as laboratory tests, x-ray and endoscopies are being used in health screening tests. As the tests determine the quality of health screening, test items and methods should be carefully selected. This study was to get hold of the test items of major health screening programs in Korea. Most of the health screening programmes focused upon detection of risk factors and diagnosis of life-style related diseases(diabetes, hypertension, cardiovascular diseases, hypercholesterolemia, overweight, drinking, smoking, cerebrovascular diseases, osteoporosis) ,cancers(stomach, cervix, lung, breast, liver, colon, prostate, ovary, pancreas, thyroid, esophagus), infectious diseases (hepatitis, tuberculosis, sexually-transmitted diseases, parasites),chronic obstructive respiratory diseases, chronic renal diseases(bacteriuria, hematuria, proteinuria), anemia, glaucoma, hearing loss, Alzheimer disease, stress, early Psychiatric diseases. The health screening tests were basic physical examination, basic laboratory tests(CBC, urinalysis, liver function tests, lipid tests, glucose, HbAlc, uric acid, electrolytes, serological tests(HBsAg, HBs-Ab, HCV-Ab, HIV-Ab, VDRL) EKG, x-ray(chest PA, CT), endoscopy (gastroscopy, colonoscopy) , sonography(abdormen, thyroid, pelvis, breast) , cytology(cervix) ,bone density, tumor markers(NMP22, alpha-FP, CEA, CA-19-9, CA12S, PSA) and eye tests. Advanced technologies, like CT, PET, MIRI, MIRI/Angio, molecular testings) were widely usedin hospital health screening programmes. In summary, a variety of were utilized by stages or programmes, however a few subjects. tests were utilized in health screening in Korea. Those tests according to sex and age in most of health screening program used tests to excess disregarding health screening subject.

• Journal of the Korean Ceramic Society
• /
• v.43 no.12 s.295
• /
• pp.764-767
• /
• 2006

Ni/YSZ $(Y_2O_3-stabilized\;ZrO_2)$ composite as an electrode component for High Temperature Electrolysis (HTE) was fabricated by mechanical alloying method using Ni and YSZ powders. Characterization of the synthesized composite was investigated with various analysis tools, including XRD, SEM and PSA, and a self-supporting planar unit cell prepared with the Ni/YSZ composite was prepared to study the electrochemical reactions for the production of hydrogen. The Ni/YSZ cermet is composed of crystalline Ni and YSZ, in a sub-micro scale, and has an even distribution without aggregated particles. In addition, under an electrochemical reaction, the unit cell showed an $H_2$ evolution rate from steam of 14 Nml/min and $600mA/cm^2$ of current density at the electrode.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.19 no.4
• /
• pp.589-609
• /
• 2017

This study carried out the density and energy dispersive X-ray spectroscopy and particle size analysis which are the physical characteristics of coal dust by collecting samples of coal dust in the five domestic mines to control the coal dust through ventilation in the workplace for coal mining in the country. This will contribute to a more comfortable working environment by understanding the physical characteristics of the coal dust which is derived from any hard coal produced domestically. In particular, the result of PSA analysis showed that the size of coal dust sample for this study ranged from $0.007{\sim}88.614{\mu}m$ were the particles less than $3.5{\mu}m$, the size range responsible for pneumoconiosis. To observe the flow of coal dust collected on the wind speed, the fallout of coal dust produced by the wind tunnel for the wind was measured and the particle size analysis of coal dust fallout was carried out. In addition, airborne dust is measured according to the mine velocity by using a multi-stage Anderson sampler in the mine where fine dust is generated in a large amount and the wind speed is found out to control the coal dust below $3.5{\mu}m$. In addition, natural ventilation pressure of A mine was calculated to prevent over design of the main fan.

• Particle and aerosol research
• /
• v.11 no.1
• /
• pp.9-19
• /
• 2015

This study investigated the effects of ball mill operation condition on the morphology of raw powders in the dry-type milling process using three types of ball mills traditional ball mill, stirred ball mill and planetary ball mill. Furthermore, since spherical powders offer the best combination of high hardness and high density, the optimum milling condition to produce sphere-shaped powders was studied. The applied rotation speed ranged from 200rpm (low rotation speed) to 700rpm (high rotation speed). The used ball size ranged from 1mm to 5mm. The metal powder morphology was studied using SEM, XRD and PSA. The aimed spherical powders could be obtained under the optimum experimental conditions: traditional ball mill(200rpm, 1mm ball), planetary ball mill (500rpm, 1mm ball) and also planetary ball mill (700rpm, 1 and 3 mm ball). The results show to the development of new material using spherical type copper powder/CNT composites for air-craft and automotive applications.

• The Korean Journal of Mycology
• /
• v.6 no.2
• /
• pp.25-30
• /
• 1978

Present experiments were conducted to determine the possibility of cultivation of 9 edible wild species selected among the higher fungi growing in Korea. In the investigation on the mycelial growth according t6o the different media, the mycelial growth of Coprinus comatus was fast on the CSA medium, when malt extract was added to the basal medium PSA, the mycelial of Lapista nuda and Auricularia auricula-judae was fast in growth and density. In the spawning, the mycelial growth of Pholiota squarrosa on the oak tree's sawdust, Pleurotus cornucopiae on the broad-leaves' sawdust, and Coprinus comatus on the compost was respectably fast and also it shown to be possibility of artificial cultivation owing to their carporphore budding when Coprinus comatus and Lepiota alborubescens cultivated on the rice straw, Auricularia auriculajudae and Pleurotus cornucopiae on the sawdust of the popla and Pholiota squarrosaon the sawdust of the oak tree.