Cu addition and its role in thermoelectric properties and nanostructuring in the series compounds (InSb)nCum

J.L. Cui,Y.M. Yan,H. Fu,X.J. Zhang,Y.L. Gao,Y. Deng 한국물리학회 2012 Current Applied Physics Vol.12 No.1

We have performed a comparative investigation of the series compounds (InSb)nCum to assess the roles of Cu addition on the thermoelectric properties and nanostructuring in bulk InSb. Detailed temperature dependent transport properties including electrical conductivity, the Seebeck coefficient, and thermal conductivity are presented. The Seebeck coefficients of In20Sb20Cu (m:n ¼ 1:20) are increased by 13percent in magnitude if compared to those of InSb, which is responsible for the 22 percent enhancement in the highest ZT value at 687 K. Although the magnitudes of kL are larger than those of InSb over the entire temperature range, a remarkable reduction in lattice thermal conductivities (kL) was observed with measuring temperature elevation. Such changes are mainly due to the precipitation of a large number of Cu9In4 nanoparticles with the size of smaller than 5 nm, dispersed in the matrix observed using high resolution transmission electron microscopy (HRTEM) images.

Metal bonding strength in low-temperature processed titanium using atomic force microscopy with single-wall carbon nanotube tip

Choi, E. M.,Cui, Y. H.,Kwon, S. H.,Kim, A. R.,Choi, H. S.,Lee, S. J.,Pyo, S. G. John Wiley Sons, Ltd 2014 Physica Status Solidi. Rapid Research Letters Vol.8 No.2

We report the development of a Ti-Ti bonding process at a low bonding temperature below 200 degrees C using chemically surface-activated Ti thin films and a reliable evaluation method for measuring the Ti-Ti bond strength by means of atomic force microscopy (AFM). Using Ti as an interlayer enables void-free bonding because Ti exhibits fast diffusion and oxide solubility. On the other hand, wafer bonding is an important processing step for 3D circuit integration that requires a high reliability of the process. However, the reliability of bonding-strength values obtained by employing conventional measurement devices is limited by comparably large measurement errors and restricted the availability of suitable sample material. In this study, the use of AFM to measure the bonding strength is proposed. The interfacial bonding properties depend on the Ti deposition parameters. A bonding temperature of 200 degrees C was found to be appropriate for the development of a low bonding temperature wafer-bonding process. The pretreatment methods like plasma activation and chemical activation at 200 degrees C result in a Ti bonding strength of approximately 8.22 J/m(2), sufficient for applications in 3D circuit integration. ((c) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

An etched stainless steel wire/ionic liquid-solid phase microextraction technique for the determination of alkylphenols in river water

Cui, M.,Qiu, J.,Li, Z.,He, M.,Jin, M.,Kim, J.,Quinto, M.,Li, D. Pergamon Press ; Elsevier Science Ltd 2015 Talanta Vol.132 No.-

In this study, a stainless steel wire/ionic liquid-solid phase microextraction technique was developed for the direct extraction of APs from water samples. Some parameters were optimised, such as selection of the substrate and ILs, extraction time, extraction temperature, stirring rate and sample pH, etc. The experimental data demonstrated that the etched stainless steel wire was a suitable substrate for IL-coated SPME. The coating was prepared by directly depositing the ILs onto the surface of the etched stainless steel wire, which exhibited a porous structure and a high surface area. The [C<SUB>8</SUB>MIM][PF<SUB>6</SUB>] IL exhibited maximum efficiency with an extraction time of 30min, and the aqueous sample was maintained at 40<SUP>o</SUP>C and adjusted to pH 2 under stirring conditions. The enrichment factor of the IL coating for the four APs ranged from 1382 to 4779, the detection limits (LOD, S/N=3) of the four APs ranged from 0.01 to 0.04ng mL<SUP>-1</SUP> and the RSD values for purified water spiked with APs ranged from 4.0 to 11.8% (n=3). The calibration graphs were linear in the concentration range from 0.5 to 200ng mL<SUP>-1</SUP> (R<SUP>2</SUP>>0.9569). The optimised method was successfully applied for the analysis of real water samples, and the method was suitable for the extraction of APs from water samples.

Catalytic assistance of ultrasound for manganese removal by waste oyster shells

Cui, M.,Jang, M.,Na, S.,Lee, S.,Khim, J. Academic Press 2013 Journal of environmental management Vol.115 No.-

The catalytic assistance of ultrasound (designated as US) for the removal of Mn(II) by oyster shells (designated as OS) was investigated with respect to major parameters such as pH, initial Mn(II) concentration, and US power density. The kinetic data of Mn(II) removal by the combination of oyster shells and ultrasound (OS/US) was fitted by the first-order kinetic model. Results show that the rate constant of the OS/US system was in the range 3.1-54.5 x 10<SUP>-2</SUP> min<SUP>-1</SUP>, which is about 130 times higher than that of the homogeneous oxidation of Mn(II) by O<SUB>2</SUB>, and was about two times higher than that of commercial surrogate materials (CaO and CaCO<SUB>3</SUB>) associated with US under the same operational condition. The US power densities for the OS/US system and the log-scale of the first-order rate constants showed a linear positive correlation with a slope of 0.042. X-ray diffraction, and Fourier transform infrared analyses revealed that the dissolved Mn(II) was oxidized into Mn<SUB>2</SUB>O<SUB>3</SUB> or MnO<SUB>2</SUB>, as well as precipitated in the form of MnCO<SUB>3</SUB> by OS/US.

Removal of dissolved Zn(II) using coal mine drainage sludge: Implications for acidic wastewater treatment

Cui, M.,Jang, M.,Cannon, F.S.,Na, S.,Khim, J.,Park, J.K. Academic Press 2013 Journal of environmental management Vol.116 No.-

The mechanism for the removal of Zn(II) by using coal mine drainage sludge (CMDS) was investigated by spectroscopic analysis and observations of batch tests using model materials. Zeta potential analysis showed that CMDS<SUB>25</SUB> (dried at 25 <SUP>o</SUP>C) and CMDS<SUB>550</SUB> (dried at 550 <SUP>o</SUP>C) had a much lower isoelectric point of pH (pH<SUB>IEP</SUB>) than either goethite or calcite, which are the main constituents of CMDS. This indicates that the negatively charged anion (sulfate) was incorporated into the structural networks and adsorbed on the surface of CMDS via outer-sphere complexation. The removal of Zn(II) by CMDS was thought to be primarily caused by sulfate-complexed iron (oxy)hydroxide and calcite. In particular, the electrostatic attraction of the negatively charged functional group, FeOH-SO<SUB>4</SUB><SUP>2-</SUP>, to the dissolved Zn(II) could provide high removal efficiencies over a wide pH range. Thermodynamic modeling and Fourier transform infrared spectroscopy (FT-IR) demonstrated that ZnSO<SUB>4</SUB> is the dominant species in the pH range 3-7 as the sulfate complexes with the hydroxyl groups, whereas the precipitation of Zn(II) as ZnCO<SUB>3</SUB> or Zn<SUB>5</SUB>(CO<SUB>3</SUB>)<SUB>2</SUB> (OH)<SUB>6</SUB> through the dissolution of calcite is the dominant mechanism in the pH range 7-9.6.

Residual static strength of cracked concrete-filled circular steel tubular (CFCST) T-joint

M.J. Cui,Y.B. Shao 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.18 No.4

Concrete-filled circular t steel tubular joints (CFSTJs) in practice are frequently subjected to fluctuated loadings caused by wind, earthquake and so on. As fatigue crack is sensitive to such cyclic loadings, assessment on performance of CFSTJs with crack-like defect attracts more concerns because both high stress concentration at the brace/chord intersection and welding residual stresses along weld toe cause the materials in the region around the intersection to be more brittle. Once crack initiates and propagates along the weld toe, tri-axial stresses in high gradient around the crack front exist, which may bring brittle fracture failure. Additionally, the stiffness and the load carrying capacity of the CFSTJs with crack may decrease due to the weakened connection at the intersection. To study the behaviour of CFSTJs with initial crack, experimental tests have been carried out on three full-scale CFCST T-joints with same configuration. The three specimens include one uncracked joint and two corresponding cracked joints. Load-displacement and load-deformation curves, failure mode and crack propagation are obtained from the experiment measurement. According to the experimental results, it can be found that he load carrying capacity of the cracked joints is decreased by more than 10% compared with the uncracked joint. The effect of crack depth on the load carrying capacity of CFCST T-joints seems to be slight. The failure mode of the cracked CFCST T-joints represents as plastic yielding rather than brittle fracture through experimental observation.

An Arabidopsis R2R3-MYB transcription factor, AtMYB20, negatively regulates type 2C serine/threonine protein phosphatases to enhance salt tolerance

Cui, M.H.,Yoo, K.S.,Hyoung, S.,Nguyen, H.T.K.,Kim, Y.Y.,Kim, H.J.,Ok, S.H.,Yoo, S.D.,Shin, J.S. North-Holland Pub ; Elsevier Science Ltd 2013 FEBS letters Vol.587 No.12

We have characterized the function of a plant R2R3-MYB transcription factor, Arabidopsis thaliana MYB20 (AtMYB20). Transgenic plants overexpressing AtMYB20 (AtMYB20-OX) enhanced salt stress tolerance while repression lines (AtMYB20-SRDX) were more vulnerable to NaCl than wild-type plants. Following NaCl treatment, the expressions of ABI1, ABI2 and AtPP2CA, which encode type 2C serine/threonine protein phosphatases (PP2Cs) that act as negative regulators in abscisic acid (ABA) signaling, were suppressed in AtMYB20-OX but induced in AtMYB20-SRDX. The electrophoretic mobility shift assay results revealed that AtMYB20 binds to the promoter regions containing the MYB recognition sequence (TAACTG) and an ACGT core element of ABI1 and AtPP2CA. These findings suggest that AtMYB20 down-regulates the expression of PP2Cs, the negative regulator of ABA signaling, and enhances salt tolerance.

Probabilistic dynamic analysis of truss structures

J. J. Chen,J.W.Che,H.A.Sun,H.B.Ma,M.T.Cui 국제구조공학회 2002 Structural Engineering and Mechanics, An Int'l Jou Vol.14 No.6

Radiation promotes invasiveness of non-small-cell lung cancer cells through granulocyte-colony-stimulating factor

Cui, Y-H,Suh, Y,Lee, H-J,Yoo, K-C,Uddin, N,Jeong, Y-J,Lee, J-S,Hwang, S-G,Nam, S-Y,Kim, M-J,Lee, S-J Macmillan Publishers Limited 2015 Oncogene Vol.34 No.42

Despite ionizing radiation (IR) is being widely used as a standard treatment for lung cancer, many evidences suggest that IR paradoxically promotes cancer malignancy. However, its molecular mechanisms underlying radiation-induced cancer progression remain obscure. Here, we report that exposure to fractionated radiation (2 Gy per day for 3 days) induces the secretion of granulocyte-colony-stimulating factor (G-CSF) that has been commonly used in cancer therapies to ameliorate neutropenia. Intriguingly, radiation-induced G-CSF promoted the migratory and invasive properties by triggering the epithelial–mesenchymal cell transition (EMT) in non-small-cell lung cancer cells (NSCLCs). By irradiation, G-CSF was upregulated transcriptionally by β-catenin/TCF4 complex that binds to the promoter region of G-CSF as a transcription factor. Importantly, irradiation increased the stability of β-catenin through the activation of PI3K/AKT (phosphatidylinositol 3-kinase/AKT), thereby upregulating the expression of G-CSF. Radiation-induced G-CSF is recognized by G-CSFR and transduced its intracellular signaling JAK/STAT3 (Janus kinase/signal transducers and activators of transcription), thereby triggering EMT program in NSCLCs. Taken together, our findings suggest that the application of G-CSF in cancer therapies to ameliorate neutropenia should be reconsidered owing to its effect on cancer progression, and G-CSF could be a novel therapeutic target to mitigate the harmful effect of radiotherapy for the treatment of NSCLC.

A continuous pilot-scale system using coal-mine drainage sludge to treat acid mine drainage contaminated with high concentrations of Pb, Zn, and other heavy metals

Cui, M.,Jang, M.,Cho, S.H.,Khim, J.,Cannon, F.S. Elsevier Scientific Pub. Co 2012 Journal of hazardous materials Vol.215 No.-

A series of pilot-scale tests were conducted with a continuous system composed of a stirring tank reactor, settling tank, and sand filter. In order to treat acidic drainage from a Pb-Zn mine containing high levels of heavy metals, the potential use of coal-mine drainage sludge (CMDS) was examined. The pilot-scale tests showed that CMDS could effectively neutralize the acidic drainage due to its high alkalinity production. A previous study revealed that calcite and goethite contained in CMDS contributed to dissolutive coprecipitation and complexation with heavy metals. The continuous system not only has high removal efficiencies (97.2-99.8%), but also large total rate constants (K<SUB>total</SUB>, 0.21-10.18h<SUP>-1</SUP>) for all heavy metals. More specifically, the pilot system has a much higher Zn(II) loading rate (45.3gm<SUP>-3</SUP>day<SUP>-1</SUP>) than other reference systems, such as aerobic wetland coupled with algal mats and anoxic limestone drains. The optimum conditions were found to be a CMDS loading of 280gL<SUP>-1</SUP> and a flow rate of 8Lday<SUP>-1</SUP>, and the necessary quantity of CMDS was 91.3gL<SUP>-1</SUP>day<SUP>-1</SUP>, as the replacement cycle of CMDS was determined to be 70 days.