[특강Ⅲ]Tooth Formation: Development, Evolution and Regeneration

YiPing Chen 대한체질인류학회 2002 대한체질인류학회 학술대회 연제 초록 Vol.45 No.-

Numerical analysis of the mixing of two electrolyte solutions in an electromagnetic rectangular micromixer

Yiping Chen,김창녕 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.60 No.-

This study numerically examines the mixing performance of a new magneto-hydrodynamic (MHD) mixer for two different electrolyte solutions under a uniform magnetic field. The electrodes deposited on the duct wall with different voltages induce the current, creating Lorentz force under a uniform magnetic field, which makes the fluids move for pumping and mixing without additional pumps. Differently from previous designs, the proposed micro-mixer works as a simultaneous micro-pump and micro-mixer with the electrodes distributed peripherally in a screw-driving manner on the walls. The highest mixing index of 0.999 is obtained, which indicates the micromixer can achieve a highly-efficient mixing performance.

Fabrication, Densification and Thermionic Emission Property of Lanthanum Hexaboride

Yiping Yu,Song Wang,Wei Li,Hongmei Chen,Zhaohui Chen 대한금속·재료학회 2018 ELECTRONIC MATERIALS LETTERS Vol.14 No.5

An effective way to improve sintering densification of LaB6was proposed and confirmed experimentally. Firstly, LaB6nanopowders with a cube-like shape of ~ 94.7 nm were fabricated by molten salt synthesis route at 800 °C for 1 h. Then,LaB6bulk material of 98% density was prepared by hot pressing sintering of as-synthesized LaB6nanopowders under1800 °C/50 MPa/30 min. The acquired LaB6bulk material had a work function of 2.87 eV and exhibited an excellentthermionic emission property. The saturation emission current density at 1500 and 1600 °C reached 37.4 and 44.3 A/cm2,respectively.

Numerical analysis of the mixing of two electrolyte solutions in an electromagnetic rectangular micromixer

Chen, Yiping,Kim, Chang Nyung THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2018 JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY -S Vol.60 No.-

<P><B>Abstract</B></P> <P>This study numerically examines the mixing performance of a new magneto-hydrodynamic (MHD) mixer for two different electrolyte solutions under a uniform magnetic field. The electrodes deposited on the duct wall with different voltages induce the current, creating Lorentz force under a uniform magnetic field, which makes the fluids move for pumping and mixing without additional pumps. Differently from previous designs, the proposed micro-mixer works as a simultaneous micro-pump and micro-mixer with the electrodes distributed peripherally in a screw-driving manner on the walls. The highest mixing index of 0.999 is obtained, which indicates the micromixer can achieve a highly-efficient mixing performance.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A new electromagnetic micromixer for the mixing of two electrolyte solutions

Yiping Chen,Xiaowen Fan,김창녕 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.12

A novel magneto-hydrodynamic (MHD) micro-mixer is proposed in this current study, and performed is the numerical analysis of the mixing features of two different electrolyte solutions in this device with the uniformly applied magnetic field. This fluidic device is designed in a minimized size, with mixing and pumping functions. In this device, there exist two or three curved-walled regions responsible for mixing or pumping, and three or four rectangular ducts for the inflow-, middle-, and outflow-channels. The current, induced from two different electrodes applying different electric potentials, is coupled with the applied magnetic field, yielding Lorentz force to propel the two solutions to mix. Within the mixer, the fluid is directed to flow along the curved surface in the curved-walled regions, and to move forward to the outlet. CFX code is utilized to analyze the flow characteristics. This study investigates the mixing efficiency in diverse cases with different voltages of the electrodes and with different geometries of the mixing region. The results testify that the novel mixer shows higher mixing performance when higher input voltages (absolute value) are applied to the electrodes of the mixing region, when the input voltages (absolute value) applied to the electrodes of the pumping region is lower, and when more mixing regions are adopted.

Family History, Tobacco Smoking, and Risk of Ischemic Stroke

Mengyu Fan,Jun Lv,Canqing Yu,Yu Guo,Zheng Bian,Songchun Yang,Ling Yang,Yiping Chen,Feifei Li,Yaoming Zhai,Ping Wang,Junshi Chen,Zhengming Chen,Lu Qi,Liming Li 대한뇌졸중학회 2019 Journal of stroke Vol.21 No.2

Background and Purpose Both genetic factors and smoking are associated with ischemic stroke (IS) risk. However, little is known about the potential interaction of these factors. We aimed to assess whether smoking and a positive family history interact to increase the risk of IS. Methods The nationwide prospective study recruited 210,000 men and 300,000 women in 2004 to 2008 at ages 30 to 79 years. During 9.7 years of follow-up, we documented 16,923 and 20,656 incident IS cases in men and women without major chronic diseases at baseline, respectively. Multivariable Cox regression models were used to examine associations between family history and IS. Likelihood ratio tests were used to test the smoking-family history interactions on IS. Results About 67.8% (n=135,168) of men ever smoked regularly compared with 2.7% (n=7,775) of women. Among men, a significant interaction between family history and smoking on IS was observed (P for interaction=0.03), with more pronounced association between family history and IS among ever-regular smokers (hazard ratio [HR], 1.21; 95% confidence interval [CI], 1.16 to 1.27) than among never-smokers (HR, 1.11; 95% CI, 1.01 to 1.23). The association between family history and IS among ex-smokers after more than 10 years of cessation (HR, 1.01; 95% CI, 0.85 to 1.20) appeared similar to that among never-smokers. Among women, a similar but not significant interaction between family history and smoking on IS was observed. Ever-regular smokers who had a family history of stroke had the highest risk of IS. Conclusions Among Chinese men, the association of family history with IS was accentuated by smoking, and such accentuation tended to be lowered by cessation.

Bonding Strength of Conductive Inner-Electrode Layers in Piezoelectric Multilayer Ceramics

Yiping Wang,Ying Yang,Bingjin Zheng,Jing Chen,Jinyi Yao,Yun Sheng 한국전기전자재료학회 2017 Transactions on Electrical and Electronic Material Vol.18 No.4

Multilayer ceramics in which piezoelectric layers of 0.90 Pb(Zr0.48Ti0.52)O3 -0.05 Pb(Mn1/3Sb2/3)O3 -0.05 Pb(Zn1/3Nb2/3)O3(0.90PZT-0.05PMS-0.05PZN) stack alternately with silver electrode layers were prepared by an advanced low-temperatureco-fired ceramic (LTCC) method. The electrical properties and bonding strength of the multilayers were associated with theinterface morphologies between the piezoelectric and silver-electrode layers. Usually, the inner silver electrodes are fabricatedby sintering silver paste in multi-layer stacks. To improve the interface bonding strength, piezoelectric powders of0.90PZT-0.05PMS-0.05PZN with an average particle size of 23 μm were added to silver paste to form a gradient interface. SEMobservation indicated clear interfaces in multilayer ceramics without powder addition. With the increase of piezoelectricpowder addition in the silver paste, gradient interfaces were successfully obtained. The multilayer ceramics with gradientinterfaces present greater bonding strength as well as excellent piezoelectric properties for 30~40 wt% of added powder. Onthe other hand, over addition greatly increased the resistance of the inner silver electrodes, leading to a piezoelectric behaviorlike that of bulk ceramics in multilayers.

Mechanism and Application of NMOS Leakage with Intra-Well Isolation Breakdown by Voltage Contrast Detection

Chen, Hunglin,Fan, Rongwei,Lou, Hsiaochi,Kuo, Mingsheng,Huang, Yiping The Institute of Electronics and Information Engin 2013 Journal of semiconductor technology and science Vol.13 No.4

An innovative application of voltage-contrast (VC) inspection allowed inline detection of NMOS leakage in dense SRAM cells is presented. Cell sizes of SRAM are continual to do the shrinkage with bit density promotion as semiconductor technology advanced, but the resulting challenges include not only development of smaller-scale devices, but also intra-devices isolation. The NMOS leakage caused by the underneath n+/P-well shorted to the adjacent PMOS/N-well was inspected by the proposed electron-beam (e-beam) scan in which VC images were compared during the in-line process step of post contact tungsten (W) CMP (Chemical Mechanical Planarization) instead of end-of-line electrical test, which has a long response time. A series of experiments based on the mechanism for improving the intra-well isolation was performed and verified by the inline VC inspection. An optimal process-integration condition involved to the tradeoff between the implant dosage and photo CD was carried out.

Mechanism and Application of NMOS Leakage with Intra-Well Isolation Breakdown by Voltage Contrast Detection

Hunglin Chen,Rongwei Fan,Hsiaochi Lou,Mingsheng Kuo,Yiping Huang 대한전자공학회 2013 Journal of semiconductor technology and science Vol.13 No.4

An innovative application of voltage-contrast (VC) inspection allowed inline detection of NMOS leakage in dense SRAM cells is presented. Cell sizes of SRAM are continual to do the shrinkage with bit density promotion as semiconductor technology advanced, but the resulting challenges include not only development of smaller-scale devices, but also intra-devices isolation. The NMOS leakage caused by the underneath n+/P-well shorted to the adjacent PMOS/N-well was inspected by the proposed electron-beam (e-beam) scan in which VC images were compared during the in-line process step of post contact tungsten (W) CMP (Chemical Mechanical Planarization) instead of end-of-line electrical test, which has a long response time. A series of experiments based on the mechanism for improving the intra-well isolation was performed and verified by the inline VC inspection. An optimal process-integration condition involved to the tradeoff between the implant dosage and photo CD was carried out.

Bonding Strength of Conductive Inner-Electrode Layers in Piezoelectric Multilayer Ceramics

Wang, Yiping,Yang, Ying,Zheng, Bingjin,Chen, Jing,Yao, Jinyi,Sheng, Yun The Korean Institute of Electrical and Electronic 2017 Transactions on Electrical and Electronic Material Vol.18 No.4

Multilayer ceramics in which piezoelectric layers of $0.90Pb(Zr_{0.48}Ti_{0.52})O_3-0.05Pb(Mn_{1/3}Sb_{2/3})O_3-0.05Pb(Zn_{1/3}Nb_{2/3})O_3$ (0.90PZT-0.05PMS-0.05PZN) stack alternately with silver electrode layers were prepared by an advanced low-temperature co-fired ceramic (LTCC) method. The electrical properties and bonding strength of the multilayers were associated with the interface morphologies between the piezoelectric and silver-electrode layers. Usually, the inner silver electrodes are fabricated by sintering silver paste in multi-layer stacks. To improve the interface bonding strength, piezoelectric powders of 0.90PZT-0.05PMS-0.05PZN with an average particle size of $23{\mu}m$ were added to silver paste to form a gradient interface. SEM observation indicated clear interfaces in multilayer ceramics without powder addition. With the increase of piezoelectric powder addition in the silver paste, gradient interfaces were successfully obtained. The multilayer ceramics with gradient interfaces present greater bonding strength as well as excellent piezoelectric properties for 30~40 wt% of added powder. On the other hand, over addition greatly increased the resistance of the inner silver electrodes, leading to a piezoelectric behavior like that of bulk ceramics in multilayers.