Effects of ZrO₂-La₂O₃ co-addition on the microstructural and optical properties of transparent Y₂O₃ ceramics

Zhu, Lin-Lin,Park, Young-Jo,Gan, Lin,Go, Shin-Il,Kim, Ha-Neul,Kim, Jin-Myung,Ko, Jae-Woong Elsevier 2017 CERAMICS INTERNATIONAL Vol.43 No.11

<P><B>Abstract</B></P> <P>Commercial Y<SUB>2</SUB>O<SUB>3</SUB> powder was used to fabricate Y<SUB>2</SUB>O<SUB>3</SUB> ceramics sintered at 1600°C and 1800°C with concurrent addition of ZrO<SUB>2</SUB> and La<SUB>2</SUB>O<SUB>3</SUB> as sintering aids. One group with different contents of La<SUB>2</SUB>O<SUB>3</SUB> (0–10mol%) with a fixed amount of 1mol% ZrO<SUB>2</SUB> and another group with various contents of ZrO<SUB>2</SUB> (0–7mol%) with a fixed amount of 10mol% La<SUB>2</SUB>O<SUB>3</SUB> were compared to investigate the effects of co-doping on the microstructural and optical properties of Y<SUB>2</SUB>O<SUB>3</SUB> ceramics. At low sintering temperature of 1600°C, the sample single doped with 10mol% La<SUB>2</SUB>O<SUB>3</SUB> exhibits much denser microstructure with a few small intragranular pores while the samples with ZrO<SUB>2</SUB> and La<SUB>2</SUB>O<SUB>3</SUB> co-doping features a lot of large intergranular pores leading to lower density. When the sintering temperature increases to 1800°C, samples using composite sintering aids exhibit finer microstructures and better optical properties than those of both ZrO<SUB>2</SUB> and La<SUB>2</SUB>O<SUB>3</SUB> single-doped samples. It was proved that the grain growth suppression caused by ZrO<SUB>2</SUB> overwhelms the acceleration by La<SUB>2</SUB>O<SUB>3</SUB>. Meanwhile, 1mol% ZrO<SUB>2</SUB> acts as a very important inflection point with regard to the influence of additive concentration on the transmittance, pore structure and grain size. The highest in-line transmittance of Y<SUB>2</SUB>O<SUB>3</SUB> ceramic (1.2mm in thickness) with 3mol% of ZrO<SUB>2</SUB> and 10mol% of La<SUB>2</SUB>O<SUB>3</SUB> sintered at 1800°C for 16h is 81.9% at a wavelength of 1100nm, with an average grain size of 11.2µm.</P>

Fabrication of transparent Y₂O₃ ceramics with record-high thermal shock resistance

Zhu, Lin-Lin,Park, Young-Jo,Gan, Lin,Kim, Ha-Neul,Ko, Jae-Woong,Kim, Hai-Doo Elsevier 2018 Journal of the European Ceramic Society Vol.38 No.11

<P><B>Abstract</B></P> <P>Sintering-additive-free fine-grained highly transparent Y<SUB>2</SUB>O<SUB>3</SUB> ceramics featuring record-high thermal shock resistance were fabricated using commercial powders via vacuum pre-sintering (1375–1550 °C) followed by hot-isostatic pressing (1450 °C). The sample pre-sintered at 1450 °C provides the optimum microstructure for post HIPing, which resulted in a grain size of 0.64 μm. The transmittance, microhardness and fracture toughness of the thus HIPed sample are 80.8% at 1100 nm and 65.5% at 400 nm (1.2 mm thick), 8.0 ± 0.02 GPa and 1.00 ± 0.06 MPa m<SUP>1/2</SUP>, respectively. The thermal conductivity increases from 13.1 to 16.5 W/m/K with increasing vacuum pre-sinterin Proc. SPIE-Int. Soc. Opt g temperature from 1450 to 1550 °C. This hybrid sintering method realized high thermal conductivity and high strength simultaneously. Consequently, the thermal shock resistance of the HIPed specimen vacuum pre-sintered at 1450 °C in this work is the highest ever reported to the best of our knowledge, which makes the developed material a promising candidate for high-power laser host and IR dome.</P>

Bio-inspired Fabrication of Cu-Ni Coatings onto Mercerized Flax Fabric by Electroless Plating

Lin Zhu,Hang Zhao,Bijian Lan,Lei Hou,Siyi Bi,Yumeng Xu,Yinxiang Lu 한국섬유공학회 2020 Fibers and polymers Vol.21 No.2

This research mainly prepared a bio-friendly electromagnetic interference (EMI) shielding fabric, and discussed the influence of the grammage (i.e. 120 g/m2, 160 g/m2 and 210 g/m2, etc) of fabric substrate on the preparation of metalbased EMI shielding conductive fabric by electroless plating. A series of steps involved mercerization, dopamine (DoPA) modification, Ni0 seeding and electroless copper-nickel (Cu-Ni) plating were carried out to fabricate ideal EMI shielding fabric. The prepared Cu-Ni fabric endowed relatively high EMI shielding effectiveness (SE) (34.80-42.00 dB) ranging from 30 to 4500 MHz, which made it a huge potential in the field of wearable EMI shielding. Moreover, another discovery was that a relative higher grammage may lead to a lower total metal loading. Furthermore, Fourier transformation infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) measurements were conducted to verify the introduction of functional groups in mercerization, modification and activation procedures. The crystalline phases and morphologies of resulting Cu-Ni coatings were characterized by X-ray diffraction (XRD) and field emission-scanning electron microscopy (FE-SEM) measurements. The atomic ratio (at.%) of Cu and Ni in the sample was determined by Energy Dispersive X-ray Spectroscopy (EDX) measurements. Overall, the Cu-Ni alloy fabric prepared in this research met the requirements of health, coating lining and EMI shielding.

Target engagement of ginsenosides in mild cognitive impairment using mass spectrometry-based drug affinity responsive target stability

Zhu, Zhu,Li, Ruimei,Qin, Wei,Zhang, Hantao,Cheng, Yao,Chen, Feiyan,Chen, Cuihua,Chen, Lin,Zhao, Yunan The Korean Society of Ginseng 2022 Journal of Ginseng Research Vol.46 No.6

Background: Mild cognitive impairment (MCI) is a transitional condition between normality and dementia. Ginseng is known to have effects on attenuating cognitive deficits in neurogenerative diseases. Ginsenosides are the main bioactive component of ginseng, and their protein targets have not been fully understood. Furthermore, no thorough analysis is reported in ginsenoside-related protein targets in MCI. Methods: The candidate protein targets of ginsenosides in brain tissues were identified by drug affinity responsive target stability (DARTS) coupled with label-free liquid chromatography-mass spectrometry (LC-MS) analysis. Network pharmacology approach was used to collect the therapeutic targets for MCI. Based on the above-mentioned overlapping targets, we built up a proteineprotein interaction (PPI) network in STRING database and conducted gene ontology (GO) enrichment analysis. Finally, we assessed the effects of ginseng total saponins (GTS) and different ginsenosides on mitochondrial function by measuring the activity of the mitochondrial respiratory chain complex and performing molecular docking. Results: We screened 2526 MCI-related protein targets by databases and 349 ginsenoside-related protein targets by DARTS. On the basis of these 81 overlapping genes, enrichment analysis showed the mitochondria played an important role in GTS-mediated MCI pharmacological process. Mitochondrial function analysis showed GTS, protopanaxatriol (PPT), and Rd increased the activities of complex I in a dose-dependent manner. Molecular docking also predicted the docking pockets between PPT or Rd and mitochondrial respiratory chain complex I. Conclusion: This study indicated that ginsenosides might alleviate MCI by targeting respiratory chain complex I and regulating mitochondrial function, supporting ginseng's therapeutic application in cognitive deficits.

Tube Voltage, DNA Double-Strand Breaks, and Image Quality in Coronary CT Angiography

Lin Zhu Xiao,Zhou Fan,Schoepf U. Joseph,Pillai Balakrishnan,Zhou Chang Sheng,Quan Wei,Bao Xue Qin,Lu Guang Ming,Zhang Long Jiang 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.8

Objective: To evaluate the effects of tube voltage on image quality in coronary CT angiography (CCTA), the estimated radiation dose, and DNA double-strand breaks (DSBs) in peripheral blood lymphocytes to optimize the use of CCTA in the era of low radiation doses. Materials and Methods: This study included 240 patients who were divided into 2 groups according to the DNA DSB analysis methods, i.e., immunofluorescence microscopy and flow cytometry. Each group was subdivided into 4 subgroups: those receiving CCTA only with different tube voltages of 120, 100, 80, or 70 kVp. Objective and subjective image quality was evaluated by analysis of variance. Radiation dosages were also recorded and compared. Results: There was no significant difference in demographic characteristics between the 2 groups and 4 subgroups in each group (all p > 0.05). As tube voltage decreased, both image quality and radiation dose decreased gradually and significantly. After CCTA, γ-H2AX foci and mean fluorescence intensity in the 120-, 100-, 80-, and 70-kVp groups increased by 0.14, 0.09, 0.07, and 0.06 foci per cell and 21.26, 9.13, 8.10, and 7.13 (all p < 0.05), respectively. The increase in the DNA DSB level in the 120-kVp group was higher than those in the other 3 groups (all p < 0.05), while there was no significant difference in the DSBs levels among these latter groups (all p > 0.05). Conclusion: The 100-kVp tube voltage may be optimal for CCTA when weighing DNA DSBs against the estimated radiation dose and image quality, with further reductions in tube voltage being unnecessary for CCTA.

Fabrication and characterization of highly transparent Y₂O₃ ceramics by hybrid sintering: A combination of hot pressing and a subsequent HIP treatment

Zhu, Lin-Lin,Park, Young-Jo,Gan, Lin,Kim, Ha-Neul,Ko, Jae-Woong,Kim, Hai-Doo Elsevier 2018 Journal of the European Ceramic Society Vol.38 No.9

<P><B>Abstract</B></P> <P>We succeeded in the optimization of highly transparent Y<SUB>2</SUB>O<SUB>3</SUB> ceramics with a submicrometer grain size approximately 0.6 μm by hot pressing (1300–1550 °C) and a subsequent HIP (1450 °C) treatment using commercial Y<SUB>2</SUB>O<SUB>3</SUB> powders as starting powders and ZrO<SUB>2</SUB> as a sintering additive. The optimum microstructure for the HIP treatment was prepared by hot pressing at a temperature as low as 1400 °C for 3 h with a relative density of 99.3%. The thus HIP-treated specimen showed the best transmittance (2 mm thick) ever reported of 83.4% and 78.3% at 1100 and 400 nm, respectively. Specifically, the transmittance using this hybrid sintering method improved substantially in the visible range compared to that of the counterpart using hot pressing only. A simulation of the transmittance based on the Beer-Lambert law and Mie scattering theory has proved that this improvement is mainly due to the elimination of nanopores below 15 nm in size.</P>

Bilateral Thoracodorsal Neuromas: A Cause of Persistent Breast Pain after Bilateral Latissimus Dorsi Breast Reconstruction

Zhu, Lin,Batdorf, Niles J,Meares, Annie L,Sukov, William R.,Lemaine, Valerie Korean Society of Plastic and Reconstructive Surge 2015 Archives of Plastic Surgery Vol.42 No.4

GPR12 Selections of the Metabolites from an Endophytic Streptomyces sp. Asociated with Cistanches deserticola

Lin, Zhen-Jian,Lu, Xiao-Ming,Zhu, Tian-Jiao,Fang, Yu-Chun,Gu, Qian-Qun,Zhu, Weiming 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.9

An endophytic Streptomyces sp. (AC-2) was isolated from the root of Cistanches deserticola Y.C.Ma.. Chemical investigations of the culture broth of AC-2 afforded fifteen compounds including K1115 A (1), tyrosol (2), phenylethylamine derivatives (3, 4), cyclic dipeptides (5-8), nucleosides and their aglycones (9-13), N-acetyltryptamine (14), and pyrrole-2-carboxylic acid (15). Only tyrosol can promote an increase of intracellular cAMP special on GPR12 transfected cells, such as CHO and HEK293, which means it may be a possible ligand for GPR12.

Thermal Stability and Fracture Toughness of Epoxy Resins Modified with Epoxidized Castor Oil and Al₂O₃ Nanoparticles

Zhu, Lin,Jin, Fan-Long,Park, Soo-Jin Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.8

This study examined the effects of the epoxidized castor oil (ECO) and $Al_2O_3$ content on the thermal stability and fracture toughness of the diglycidylether of bisphenol-A (DGEBA)/ECO/$Al_2O_3$ ternary composites using a range of techniques. The thermal stability of the composites was decreased by the addition of ECO and $Al_2O_3$ nanoparticles. The fracture toughness of the composites was improved significantly by the addition of ECO and $Al_2O_3$ nanoparticles. The composite containing 3 wt % $Al_2O_3$ nanoparticles showed the maximum flexural strength. Scanning electron microscopy (SEM) revealed tortuous cracks in the DGEBA/ECO/$Al_2O_3$ composites, which prevented deformation and crack propagation.

An improved horizontally reversible plow design based on virtual assembly semantics and constraint

Lin Zhu,Shuang-Shuang Peng,Yin-Yin Qi,Xi Cheng,Wen-Feng Zhang,Liang-Yuan Xu,De-Quan Zhu 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.1

There exit model errors in the constructed Horizontally reversible plough (HRP) structure through Interference check technique (ICT). This is basically due to missing parts and geometric interference and, hence, has significantly adverse effects in improving HRP. In thispaper an improved design to refine the three dimensional (3D) model of HRP is implemented by using Virtual assembly technology(VAT). To achieve this, the authors propose a combined virtual assembly semantics and constraint for assembly planning and simulationof HRP in the commercial software, e.g., SolidWorks. First, the assembly planning of HRP was captured with a semantics-based model,including spatial position, assembly orientation, type and parameters of the semantic entities; secondly, the assembly simulation of HRPwas performed by using constraint-based VAT, e.g. component grasping, moving and releasing; finally, the obtained HRP model wasverified through ICT again. The results demonstrate that not any model error exists in the refined 3D HRP model any longer and thatsemantics and constrain based VAT can support the interactive operation more effectively and accurately than those with geometric constraints. This technique was previously used for HRP model. Based on the refined 3D HRP model, the design improvement of Remotecylinder base (RCB), an important component of HRP, will be forthcoming in a future paper.