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Pressure Wave and Fluid Velocity in a Bend-Mode Inkjet Nozzle with Double PZT Actuators

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Journal of Thermal Science 2013年第1期22卷 29-35页

作者： Sungu Kim Jaeyong Sung myeong ho Lee Graduate School Dept.of Mechanical EngineeringSeoulTech Dept.of Mechanical and Automotive Engineering SeoulTech

A new concept of bend-mode inkjet nozzle with double PZT (lead zirconate titanate) actuators has been designed and fabricated in the present study. Then the pressure wave and fluid velocity at the nozzle exit have been investigated. The complex pressure behavior inside the channel was solved numerically based on the narrow channel acoustic theory. The two PZTs attached to a rectangular channel were actuated sequentially by setting the waveforms of each PZT to be center-aligned with various pulse widths. As a result, the double PZT actuation is superior to the single PZT actuation in view of strong momentum force and fast dissipation of residual pressure. The maximum fluid velocity at the nozzle exit is observed when the respective pulse widths equal to their optimum pulse widths. The numerical results are supported by the experimental results with the fabricated inkjet device by measuring the speed of meniscus just out of the nozzle.

关键词： double PZT actuators inkjet nozzle narrow channel theory pressure wave sequential actuation

Oxidative coupling of methane over LaAlO3 perovskite catalysts prepared by a co-precipitation method: Effect of co-precipitation pH value

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Journal of Energy Chemistry 2019年第8期28卷 1-8,I0001页

作者： Yujin Sim Jihoon Yoo Jeong-myeong Ha Ji Chul jung Department of Chemical Engineering Myongji UniversityYongin 17058 Republic of Korea Clean Energy Research Center Korea Institute of Science and TechnologySeoul 02792 Republic of Korea

Oxidative coupling of methane(OCM) was conducted over LaAlO3X catalysts that were prepared by a coprecipitation method using different co-precipitation pH values(X = 6–10). The aim is to investigate the effect of p H values on the catalytic activity of La AlO3 catalysts in this reaction. The results showed that the co-precipitation pH value affected greatly on the formation of chemical species of precipitate precursors in the co-precipitation step, leading to different phases of the finally obtained LaAlO3 *** the co-precipitation pH value increased up to 8, the lanthanum-related phases such as La2 O3 and La(OH)3 were gradually formed as by-products, preventing the formation of LaAlO3 perovskite crystalline structure and facilitating the formation of oxygen vacancies on catalyst surface. however, at pH value of9 or higher, the lanthanum content in the precipitate precursor was increased greatly. Not LaAlO3 perovskite but lanthanum-related phases were developed as main phases, reducing their catalytic activities in this reaction. Among LaAlO3 catalysts, the one prepared at pH = 8 showed the highest C2 yield due to its well-developed oxygen vacancies and electrophilic lattice oxygen. Therefore, the co-precipitation pH value strongly affected the LaAlO3 catalyst activity in OCM reaction. A precious pH control should be required to prepare various perovskite catalysts for the OCM.

关键词： LaAlO3 Perovskite Oxidative coupling of methane Co-precipitation pH value

Gastric choriocarcinoma admixed with an α-fetoprotein-producing adenocarcinoma and separated adenocarcinoma

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World Journal of Gastroenterology 2009年第40期15卷 5106-5108页

作者： Bang Wool Eom So-Youn jung hongman Yoon myeong-Cherl Kook Keun Won Ryu Jun ho Lee Young-Woo Kim Center for Gastric Cancer National Cancer Center

We report a case of gastric choriocarcinoma admixed with an α-fetoprotein (AFP)-producing adeno-carcinoma. A 70-year-old man was hospitalized for gastric cancer that was detected during screening by esophagogastroduodenoscopy (EGD). Initial laboratory data showed the increased serum level of AFP and EGD revealed a 5-cm ulcerofungating mass in the greater curvature of the gastric antrum. The patient underwent radical subtotal gastrectomywith D2 lymph node dissection and Billroth gastrojejunostomy. Histopathological evaluation confirmed double primary gastric cancer: gastric choriocarcinoma admixed with an AFP-producing adenocarcinoma and separated adenocarcinoma. At 2 wk postoperatively, his human chorionic gonadotropin and AFP levels had reduced and six cycles of adjuvant chemotherapy were initiated. No recurrence or distant metastasis was observed at 4 years postoperatively.

关键词： α-fetoproteins Adenocarcinoma Choriocarcinoma Stomach neoplasms

Recognition of Association Between Blood Stasis Syndrome and Traumatic Injury among Doctors of Korean Medicine:A Cross-Sectional Observation Study

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Chinese Journal of Integrative Medicine 2018年第4期24卷 254-259页

作者： Jeeyoun jung Mi Mi Ko Ju Ah Lee myeong Soo Lee Korean Medicine Fundamental Research Division Korea Institute of Oriental Medicine Clinical Research Division Korea Institute of Oriental Medicine

Objective： To investigate the diagnostic indicators and herbal treatments for blood stasis syndrome（BSS） patients with traumatic injuries and to identify the association between BSS and traumatic injury in Korea. Methods： Two-hundred and four patients with traumatic injury were recruited from the Gangnam and Daejeon branches of Jaseng hospital of Oriental Medicine between June 2014 and December 2014. Two independent doctors of Korean medicine（DKMs） determined the diagnosis of BSS or non-BSS based on the subjects＇ signs and symptoms. The scores assigned to BSS symptoms and DKMs＇ reasons for diagnosing BSS in patients with traumatic injury were investigated. Both medication and herbal prescription records from a 3-month period were collected for all patients diagnosed with BSS by both DKMs. Results： A total of 169 of 204（82.8%） patients received consistent diagnosis related to BSS by two DKMs. Among them, 54.4%（92 cases） were diagnosed with BSS, and 45.6%（77 cases） were not diagnosed with BSS. DKMs most frequently cited symptoms of recent traumatic injury as justifications for BSS diagnoses, and also selected pain-related indicators such as abdominal pain, sharp pain and nocturnal pain as important reasons in diagnosing BSS. In addition, an inconsistency in the pattern identification theory with respect to traumatic injury was observed. Although only 92 cases（54.4%） of patients were diagnosed with BSS, 77.6% of them were prescribed decoctions for BSS. Conclusions： DKMs considered traumatic injury could cause BSS, and utilized decoction for BSS in patients with traumatic injury without confirming a diagnosis of BSS because they assumed the main symptoms or pathologies of traumatic injury to be closely related to BSS.

关键词： blood stasis syndrome Korean medicine traumatic injury herbal medicine diagnosis pattern identification

Inter-observer Reliability of Indicators and Decision of Pattern Identification Using Diagnostic Flowchart with Traditional Korean Medicine

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Chinese Journal of Integrative Medicine 2017年第5期23卷 338-344页

作者： Ju Ah Lee Jeeyoun jung Mi Mi Ko myeong Soo Lee Korean Medicine Fundamental Research Division Korea Institute of Oriental Medicine Daejeon 305-811 Republic of Korea Clinical Research Division Korea Institute of Oriental Medicine Daejeon 305-811 Republic of Korea

Objective： To evaluate the consistency of patterns and pattern identification（PI）, and the improvement in the diagnosis of blood stasis after the standard operating procedures（SOPs） were enhanced by using a diagnostic flowchart. Methods： A total of 358 subjects who were admitted by the Jaseng hospital of Korean Medicine between June 2013 and December 2014 were included in the study. Each patient was independently diagnosed by two experts from the same department. In 2014, the SOPs included the use of a diagnostic flowchart for each indicator. Inter-observer consistency was assessed by simple percent agreement and by the kappa and AC1 statistics. Results： The improvements in inter-observer agreement for the indicators（for al patients） and PI were greater in 2014 than in 2013. In 2013, the j-value measure of agreement between the two experts ranged from ＂poor＂（κ=–0.051） to ＂good＂（κ=0.968）. The AC1 measure of agreement between the experts was generally high for the indicators and ranged from –0.010 to 0.978. In most cases, agreement was considerably lower when it was assessed by the j-values compared with the AC1 values. In 2014, the j-value measure of agreement on the indicators（for the subjects） general y ranged from poor to good, with the values ranging from –0.007 to 0.994. Moreover, the AC1 measure of agreement between the experts was general y high for al of the indicators and ranged from ＂moderate＂（AC1=0.408） to ＂excel ent＂（AC1=0.996）. Conclusions： In four examinations, there was moderate agreement between the clinicians on the PI indicators of blood stasis. To improve clinician consistency（e.g., in the diagnostic criteria used）, it is necessary to analyse the reasons for inconsistency and to improve clinician training.（Trial registration No. KCT0000916）

关键词： blood stasis inter-observer reliability pattern identification traditional Chinese medicine traditional Korean medicine

Concept study of measuring gravitational constant using superconducting gravity gradiometer

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Chinese Physics B 2018年第8期27卷 130-135页

作者： Xing Bian ho jung Paik Martin Vol Moody University of Chinese Academy of Sciences Beijing 100049China Technical Institute of Physics and Chemistry Chinese Academy of SciencesBeijing 100190China Department of Physics University of MarylandCollege ParkMaryland 20742USA

Newton＇s gravitational constant G is the least known fundamental constant of nature. Since Cavendish made the first measurement of G with a torsion balance over two hundred years ago, the best results of G have been obtained by using torsion balances. however, the uncorrected anelasticity of torsion fibers makes the results questionable. We present a new method of G measurement by using a superconducting gravity gradiometer constructed with levitated test masses, which is free from the irregularities of mechanical suspension. The superconducting gravity gradiometer is rotated to generate a centrifugal acceleration that nulls the gravity field of the source mass, forming an artificial planetary system. This experiment has a potential accuracy of G better than 10 ppm.

关键词： gravitational constant superconducting gravity gradiometer artificial planetary system

Formation Mechanism of Chunky Graphite and Its Preventive Measures

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Journal of Materials Science & Technology 2008年第3期24卷 289-295页

作者： Hideo Nakae Sanghoon jung ho-Chul Shin Department of Materials Science and Engineering Waseda University National Institute of AIST Corporate Res.and Dev.Div. Hyundai.Kia Motors

The formation mechanism of chunky graphite has been reviewed and studied. The study consisted of a unidirectional solidification method, a small droplet method and a furnace cooling method. Four kinds of iron samples were prepared, namely, the pure Fe-C, Fe-C-S, Fe-C-Ce and Fe-C-Si-Ce alloys, and three kinds of nickel samples, namely the Ni-C, Ni-C-S and Ni-C-Mg alloys. The results of the unidirectional solidification of the Ni-C alloys showed that spheroidal graphite is not observed in the continuous solidified region, in which only flake-like graphite is observed, while spheroidal graphite is usually observed in the quenched liquid region. The existence of spheroidal graphite in the solidified phase is recognized only in the discontinuous growth mode of the Ni-C-Mg alloy solidified at 150 mm/h. This means that the spheroidal graphite is directly crystallized from the melt and entrapped by the flake-like chunky graphite that is formed by the continuous growth mode. In the small droplet method, a small piece of the Fe-C or Fe-C-Ce sample was melted on a pure graphite plate then cooled at a different cooling rate in a He-3%H2 atmosphere. The graphite in the Fe-C-Ce alloy is usually spherical. Nevertheless, the graphite morphology of the final solidified area changed from spherical to chunky and chunky to ledeburite with an increase in the cooling rate. This means that the chunky graphite is formed in the residual liquid region by the solidification into Fe-graphite system. The sample was cooled in a furnace, and the graphite morphology changes from spherical to chunky and chunky to ledeburite with the decrease in the Si content. These phenomena can be confirmed by the cooling curves of these samples.

关键词： Chunky graphite Spheroidal graphite Solidification Cooling curve

Application of Thermodynamic Database to Corrosion of ZrO_(2) Containing Submerged Entry Nozzle in Steel Continuous Casting Process

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China's Refractories 2024年第2期33卷 10-15页

作者： In-ho jung Department of Materials Science and Engineering Seoul National UniversitySeoul 08826South Korea Research Institute of Advanced Materials Seoul National UniversitySeoul 08826South Korea

The CALPHAD thermodynamic databases are very useful to analyze the complex chemical reactions happening in high temperature material *** FactSage thermodynamic database can be used to calculate complex phase diagrams and equilibrium phases involving refractories in industrial *** this study,the FactSage thermodynamic database relevant to ZrO_(2)-based refractories was reviewed and the application of the database to understanding the corrosion of continuous casting nozzle refractories in steelmaking was presented.

关键词： thermodynamic database ZrO_(2)containing submerged entry nozzle continous casting

Fossil-Winged Fruits of Fraxinus(Oleaceae) and Liriodendron(Magnoliaceae) from the Duho Formation,Pohang Basin,Korea

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Acta Geologica Sinica(English Edition) 2009年第5期83卷 845-852页

作者： Seung-ho jung Seong-Joo LEE Department of Geology Kyungpook National UniversityDaegu 702-701Korea

A total of 16 specimens of fossil-winged fruits were found from the Middle Miocene marine deposits, Duho Formation, Pohang Basin, Korea. They were identified into two structurally different groups： 15 specimens into a winged fruit of Fraxinus, and one specimen of Liriodendron. The most samaras （13 specimens） were identified as Fraxinus oishii, which is characterized by narrowly ovate or ovate-elliptic shapes that are 2.7-3.6 cm in length and 0.7-1 cm in width （i/w ratio=3.4-4）. The apexes of the Fraxinus oishii samara are round or slightly emarginated, and a seed of the samara is always located at the base, of which the general shape is narrow rhombic-ellipsoidal. The seed is 1.2-2 cm long and 0.5-0.7 cm wide. Two specimens are different from the samara of Fraxinus oishii. They have a 6.6 length/width ratio （3.3 cm long and 0.5 cm wide）, and thus, are temporarily classified into the Fraxinus sp. One specimen was recognized as a winged seed of Liriodendron meisenense. The wing is broadly lanceolate to elliptic in shape, has a smooth, acute apex, and is approximately 3 cm long and 0.7 cm wide. Samaras of Fraxinus oishii and Liriodendron meisenense were early reported from the Middle Miocene deposits from North Korea, but these specimens are the first discovery in South Korea. Further study of the Duho Formation may connect flora relationships between North and South Korea.

关键词： winged fruits Fraxinus Liriodendron Middle Miocene Pohang Basin Korea