Influence of tool plunge depth and welding distance on friction stir lap welding of AA5454-O aluminum alloy plates with different thicknesses

AA5454-O aluminum alloy plates with thicknesses of 1.4 and 1.0 mm were friction-stir-lap-welded (FSLWed).The influences of the tool plunge depth and welding distance on surface appearance,macrostructure and mechanical properties of the FSLWed plates were experimentally investigated.The tensile shear load of the FSLWed plates was compared with that of the adhesive-bonded plates.Defect-free FSLWed zones were successfully obtained in all the tool plunge depths and the welding distances.The FSLWed zones exhibited the relatively smooth surface morphologies.Under all the FSLWed conditions,the FSLWed zone exhibited higher average hardness than the base metal.In addition,the upper plate exhibited a higher average hardness than the lower plate,although there was no special tendency in spite of the change in the tool plunge depth and the welding distance.The maximum tensile shear load of the FSLWed plates was much higher than that of the adhesive-bonded aluminum alloy plate.Especially,under the FSLW condition of the plunge depth of 1.8 mm and the welding distance of 40 mm,the tensile shear load of the FSLWed plate reached a level about 41% greater than that of the adhesive-bonded aluminum alloy plate.In addition,the maximum tensile shear load of the FSLWed plate was increased with the increase of the welding distance.     

Hybrid functional IrO2-TiO2 thin film resistor prepared by atomic layer deposition for thermal inkjet printheads

IrO₂-TiO₂ thin films were prepared by atomic layer deposition using Ir(EtCp)(COD) and titanium isopropoxide (TTIP). The resistivity of IrO₂-TiO₂ thin films can be easily controlled from 1 500 to 356.7 μωcm by the IrO₂ intermixing ratio from 0.55 to 0.78 in the IrO₂-TiO₂ thin films. The low temperature coefficient of resistance(TCR) values can be obtained by adopting IrO₂-TiO₂ composite thin films. Moreover, the change in the resistivity of IrO₂-TiO₂ thin films was below 10% even after O₂ annealing process at 600 °C. The step stress test results show that IrO₂-TiO₂ films have better characteristics than conventional TaN_0.8 heater resistor. Therefore, IrO₂-TiO₂ composite thin films can be used as a heater resistor material in thermal inkjet printhead.     

Determination of global failure pressure for tubes with two parallel cracks

The 40% of wall thickness criterion, which has been used as a plugging rule is applicable only to a single cracked steam generator tubes. In the previous studies performed by the authors, several failure prediction models were introduced to estimate the plastic collapse pressures of steam generator tubes containing two adjacent parallel axial through‐wall cracks. These models were applied preliminarily for thin plates with two parallel through‐wall cracks and the crack opening displacement (COD) base model was selected as the optimum one. The objective of this study is to verify the applicability of the proposed failure prediction model for real steam generator tubes with two parallel axial through‐wall cracks. For this purpose, a series of plastic collapse tests and finite element analyses have been carried out for the steam generator tubes with two machined parallel axial through‐wall cracks. Thereby, it was proven that the proposed failure prediction model can be used for estimating the global failure pressure quite well. Also, interaction effects between two adjacent cracks were assessed through additional finite element analyses to investigate the effect on the global failure behaviour.     

Universally composable one-time signature and broadcast authentication

This paper analyzes trusted network connect (TNC) protocols within the universally composable (UC) framework. We propose the first TNC model in the UC framework by first designing the TNC ideal functionality FTNC, the EAP ideal functionality FEAP and the EAP-TNC ideal functionality FE-PA. Then, we construct a trusted network connect protocol named TK-TNC that UC-realizes FTNC in the (FEAP, FE-PA)- hybrid model. Subsequently, we perform a security analysis on protocol D-H PN given in the TCG specification an...     

Properties of casein micelles cross-linked by transglutaminase

Factors affecting the cross-linking of milk proteins by transglutaminase (TGase) were studied. Cross-linking of caseins in bovine skim milk was optimal over a very wide pH range. The role of micellar calcium phosphate (MCP) in maintaining the integrity of TGase-treated casein micelles was studied by incubating skim milk with 0.01% (w/v) TGase at 30°C for 1–24 h, followed by removal of MCP from untreated or TGase-treated milk by acidification and dialysis. The protein content and profile of the samples were determined by Kjeldahl and SDS-PAGE, respectively. Whey proteins in unheated milk were not susceptible to TGase-induced cross-linking. The higher level of sedimentable protein in MCP-free TGase-treated milk than in MCP-free control milk indicated that TGase treatment partially prevented disintegration of the micelle on removal of MCP, probably due to extensive intramicellar TGase-induced cross-linking of casein molecules which led to the formation of sedimentable covalently bonded casein aggregates.     

AKT regulates IL-1β-induced proliferation and activation of hepatic stellate cells

Background: Activated hepatic stellate cells (HSCs) are closely involved in the initiation, perpetuation, andresolution of liver fibrosis. Pro-inflammatory cytokine levels are positively correlated with the transition from liverinjury to fibrogenesis and contribute to HSC pathophysiology in liver fibrosis. Methods: In this study, we investigatedthe effect of the pro-inflammatory cytokine interleukin (IL)-1β on the proliferation and signaling pathways involvedin fibrogenesis in LX-2 cells, an HSC cell line, using western blotting and cell proliferation assays. Results: IL-1βincreased the proliferation rate and α-smooth muscle actin (SMA) expression of LX-2 cells in a dose-dependentmanner. Within 1 h after IL-1β treatment, c-Jun N-terminal kinase (JNK), p38, and nuclear factor-κB (NF-κB)signaling was activated in LX-2 cells. Subsequently, protein kinase B (AKT) phosphorylation and an increase in α-SMA expression were observed in LX-2 cells. Each inhibitor of JNK, p38, or NF-κB decreased cell proliferation, AKTphosphorylation, and α-SMA expression in IL-1β-treated LX-2 cells. Conclusion: These results indicate that JNK,p38, and NF-κB signals converge at AKT phosphorylation, leading to LX-2 activation by IL-1β. Therefore, the AKTsignaling pathway can be used as a target for alleviating liver fibrosis by the inflammatory cytokine IL-1β.     

Improvement in classification accuracy of stainless steel alloys by laser-induced breakdown spectroscopy based on elemental intensity ratio analysis

Laser-induced breakdown spectroscopy(LIBS) is a useful technique for accurate sorting of metal scrap by chemical composition analysis.In this work,a method for intensity-ratiobased LIBS classification of stainless steel applicable to highly fluctuating LIBS signal conditions is proposed.The spectral line pairs for intensity ratio calculation are selected according to elemental concentration and upper levels of emission lines.It is demonstrated that the classification accuracy can be significantly improved from that of full-spectra principal component analysis or intensity-based analysis.The proposed method is considered to be suited to an industrial scrap sorting system that requires minimal maintenance and low system price.     

Effect of process parameters on electrical, optical properties of IZO films produced by inclination opposite target type DC magnetron sputtering

IZO films were deposited onto PET substrate at room temperature with the inclined opposite target type DC magnetron sputtering equipment, in which a sintered oxide IZO target (doped with 10% ZnO, packing density of 99.99%) was used. The effects of total sputtering pressure and film thickness on IZO films properties were studied. All the films produced at room temperature have a amorphous structure, irrespective of the total sputtering pressure and film thickness. A resistivity of the order of 10⁻⁴ Ω·cm was obtained for IZO films deposited at lower pressure (film thickness of 190 nm). The resistivity of IZO films deposited at room temperature depends on film thickness and shows a minimum at a thickness of 530 nm.     

Effect of hydro co-extrusion on microstructure of duo-cast Al 3003/Al 4004 clad materials

The effects of hydro co-extrusion on the microstructure changes of aluminum hybrid duo-cast Al 3003/Al 4004 clad materials were studied. The specimen of duo-cast Al 3003/Al 4004 clad materials was in circle shape, and was composed of Al 3003(outside) and Al 4004(inside) materials. The specimen was extruded by the hydro co-extrusion equipment. The manufacturing conditions of the specimen were 423 K in temperature and 5 in extrusion ratio. The dimensions of the specimen were 80 mm in diameter of the Al 4004 material and 35 mm in thickness of the Al 3003 material before the hydro co-extrusion process, and 30 mm in diameter and about 5 mm in thickness after the extrusion process, respectively. The microstructure and the hardness for two specimens were investigated. The hardness value of cross section in the duo-cast Al 3003/Al 4004 clad materials before the extrusion process was increased in form of the parabola toward the center. However, after the extrusion process, it was almost constant in the portion of Al 4004 material. Lots of big voids above 1 mm in diameter in the specimen existed in the interfacing region of Al 3003 and Al 4004 materials before the extrusion process. These big voids disappeared after the process of hydro co-extrusion.     

Neural connectivity inference with spike-timing dependent plasticity network

Knowing the connectivity patterns in neural circuitry is essential to understand the operating mechanism of the brain,as it allows the analysis of how neural si...