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Zinc plating using the principle of sacrificial anode is used to prevent steel corrosion. Pure zinc plating has some problems and Zn-Mn alloy plating has been studied as one of the measures to increase the corrosion resistance. Zn-Mn alloy plating can be applied to automotive parts requiring high corrosion resistance despite high plating cost. In this study, Zn-Mn alloy plating was electrodeposited in acidic chloride solution. The effects of electrolytic conditions on the composition of the alloy plating in the chloride bath were investigated. As the current density increased, the Zn content decreased and the Mn content increased. As the temperature of the electrolyte increased, the Zn content decreased and the Mn content increased.

We experimentally investigate the cross-plane figure of merit (ZT) for an Al2O3/ZnO (AO/ZnO) superlattice film by measuring cross-plane electrical and thermal conductivity and Seebeck coefficient using the 3-ω method and an in-house Seebeck coefficient measurement system recently developed for 300–500 K and examine how ZT factors depend on the AO layer inside the AO/ZnO superlattice film using measured thermoelectric properties. The AO/ZnO superlattice film exhibited maximum power factor of ∼276.2 μW/m K2 with low thermal conductivity (∼0.31 W/m K), producing ZT ≥ 0.45 at 500 K, which is approximately 2,650% improvement compared with an undoped ZnO film (∼0.017). The enhanced ZT performance of the AO/ZnO superlattice film can be explained by enhanced phonon scattering at the interface and minority carrier blocking at the interfacial barrier due to the AO layer, suggesting that the interfacial AO layer is important to enhance ZT in oxide-based films. These results open new applications for micro- or nanosc...

We report on the electrical properties of natural p-type GeSe nanoflakes, which were mechanically exfoliated from GeSe single crystals by the polydimethylsiloxane (PDMS) stamp method, using a back-gate field effect transistor (FET) measured in a vacuum probe station at room temperature. In this study, we used two contact metals, including Au and Cr metals, as the Ohmic contacts to the GeSe nanoflake FETs, resulting in an Ohmic behavior with the Au contacts, with a total resistance of 5.5 × 106 Ω. We also found that the 40-nm-thick GeSe nanoflake FET exhibits clear p-type semiconductor behavior with a field-effect mobility of ∼1.0 × 10–3 cm2/(V · s) and a current on/off ratio of ∼104 at room temperature.

School of materials Science and engineering, Inha University, Incheon 402-751, Korea(Received March 13, 2015 ; revised April 27, 2015 ; accepted April 28, 2015)AbstractNickel is a commercially important and versatile element in electroplating. The applications of nickel elec-troplating fall into three main categories: decorative, functional and electroforming. In decorative applications,electroplated nickel is most often applied in combination with electrodeposited chromium. Nickel is depositedon surfaces to improve corrosion and wear resistance or modify magnetic and other properties. Electroformingis electroplating applied to the fabrication of products of various kinds. Nickel is deposited onto a substrateand then removed from it to create a part made entirely of nickel. In this study, mechanical property ofNi electrodeposits in various manufacturing condition such as temperature, current density, pH and electrolytecontent, was investigated to understand effect of electrolysis condition on mechanical property. Vickers hardnessincreased as the temperature and pH increased and current density and electrolyte content decreased andpH increased. The results were explained by cathode overvoltage and hydrogen evolution.

In this study, in order to increase surface ability of hardness and corrosion of magnesium alloy, anodizingand sealing with nano-diamond powder was conducted. A porous oxide layer on the magnesium alloy was successfullymade at 85 o C through anodizing. It was found to be significantly more difficult to make a porous oxide layer in themagnesium alloy compared to an aluminum alloy. The oxide layer made below 73 o C by anodizing had no porous layer.The electrolyte used in this study is DOW 17 solution. The surface morphology of the magnesium oxide layer wasinvestigated by a scanning electron microscope. The pores made by anodizing were sealed by water and aqueous nano-diamond powder respectively. The hardness and corrosion resistance of the magnesium alloy was increased by the anod-izing and sealing treatment with nano-diamond powder.Keywords: Magnesium, Anodizing, Sealing Treatment, Nano-diamond powder ·······························································································································································································································

School of materials science and engineering, Inha University, Incheon 402-751, Korea(Received June 10, 2014 ; revised June 15, 2014 ; accepted June 22, 2014)AbstractIn this study, in order to improve corrosion resistance and wear resistance of aluminum, surface treatmentwas made by anodizing with oxalic acid solution and sealing with nano-diamond powder. Average size ofnano-diamond powder was 30nm. Anodizing with oxalic acid made many pores in the aluminum oxide layer.Pore size and oxide thickness were investigated by scanning electron microscope (SEM). Pore size increasedas temperature increased and voltage increased. It was possible to make oxide layer with pore diameter morethan 50 nm. Oxide thickness increased as temperature and voltage and treatment time increased. Oxide layerwith above 10µm thickness was made. Aluminum oxide layer with many pores was sealed by water withnano-diamond powder. Surface morphology was investigated by SEM. After sealing treatment with nano-diamond powder, corrosion resistance, wear resistance and hardness increased.

The addition of cyclo propane carbonyl (cpc) to chromium electroplating bath resulted in a chromium deposit which had greatly improved mechanical properties compared to conventional chromium deposits in condition of heat treatment at high temperature. The as-deposited layers had a Vicker`s hardness of about 1170, which is comparable to that of conventional chromium plating deposits. With annealing, the hardness goes through a maximum of 1650 at . Generally speaking, the hardness of conventional plating decreases monotonically with heat treatment. X-ray diffraction show that annealing up to above causes formation and growth of chromium crystallites and that chromium carbides form at above temperature.

In this study, electrolytic copper powders were consolidated by high-pressure torsion process (HPT) which is the most effective process to produce bulk ultrafine grained and nanocrystalline metallic materials among various severe plastic deformation processes. The bulk samples were manufactured by the HPT process at 2.5 GPa and 1/2, 1 and 10 turns. After 10 turns, full densification was achieved by high pressure with shear deformation and ultrafine grained structure (average grain size of 677 nm) was observed by electron backscatter diffraction and a scanning transmission electron microscope.

Anthocyanins, which are bioactive phytochemicals, are widely distributed in plants and especially enriched in tart cherries. Based on previous observations that tart cherry anthocyanins and their respective aglycone, cyanidin, can inhibit cyclooxygenase enzymes, we conducted experiments to test the potential of anthocyanins to inhibit intestinal tumor development in Apc(Min) mice and growth of human colon cancer cell lines. Mice consuming the cherry diet, anthocyanins, or cyanidin had significantly fewer and smaller cecal adenomas than mice consuming the control diet or sulindac. Colonic tumor numbers and volume were not significantly influenced by treatment. Anthocyanins and cyanidin also reduced cell growth of human colon cancer cell lines HT 29 and HCT 116. The IC(50) of anthocyanins and cyanidin was 780 and 63 microM for HT 29 cells, respectively and 285 and 85 microM for HCT 116 cells, respectively. These results suggest that tart cherry anthocyanins and cyanidin may reduce the risk of colon cancer.

The cluster variation method (CVM) based on the octahedron and tetrahedron approximation was applied to the calculation of γ(TiAl, L10)/α 2(Ti3Al, D019) phase equilibrium in the Ti-Al-X (X=V, Mn, Nb, Cr, Mo, Ni, and Co) systems. The antiphase boundary (APB) energy, the long-range order (LRO) parameter, and the substitution behavior of the γ(TiAl, L10) were calculated. The results of calculations were in good agreement with the data determined experimentally.

The 〈100〉, 〈111〉 and 〈110〉 textures of copper electrodeposits obtained from copper sulfate baths changed to the 〈100〉, 〈100〉 and 〈 $$\sqrt {\text{3}} 10$$ 〉 textures, respectively, after recrystallization. The textures of chromium electrodeposits obtained from the standard Sargent bath remained unchanged after recrystallization. The results are in agreement with the prediction of the strain energy release maximization model, in which the recrystallized grains orient themselves so that their minimum elastic modulus direction can be parallel to the absolute maximum internal stress direction due to dislocations in the non-recrystallized grains.

The mechanisms underlying tumor dormancy have been elusive and not well characterized. We recently published an experimental model for the study of human tumor dormancy and the role of angiogenesis, and reported that the angiogenic switch was preceded by a local increase in VEGF-A and basic fibroblast growth factor. In this breast cancer xenograft model (MDA-MB-436 cells), analysis of differentially expressed genes revealed that heat shock protein 27 (HSP27) was significantly up-regulated in angiogenic cells compared with nonangiogenic cells. The effect of HSP27 down-regulation was further evaluated in cell lines, mouse models, and clinical datasets of human patients with breast cancer and melanoma. Stable down-regulation of HSP27 in angiogenic tumor cells was followed by long-term tumor dormancy in vivo. Strikingly, only 4 of 30 HSP27 knockdown xenograft tumors initiated rapid growth after day 70, in correlation with a regain of HSP27 protein expression. Significantly, no tumors escaped from dormancy without HSP27 expression. Down-regulation of HSP27 was associated with reduced endothelial cell proliferation and decreased secretion of VEGF-A, VEGF-C, and basic fibroblast growth factor. Conversely, overexpression of HSP27 in nonangiogenic cells resulted in expansive tumor growth in vivo. By clinical validation, strong HSP27 protein expression was associated with markers of aggressive tumors and decreased survival in patients with breast cancer and melanoma. An HSP27-associated gene expression signature was related to molecular subgroups and survival in breast cancer. Our findings suggest a role for HSP27 in the balance between tumor dormancy and tumor progression, mediated by tumor–vascular interactions. Targeting HSP27 might offer a useful strategy in cancer treatment.