Mechanical Properties and Microstructure of Thin Plates of A6061 Wrought Aluminum Alloy Using Rheology Forging Process with Electromagnetic Stirring

We propose the possibility of fabricating A6061 thin plates using the rheology forging process. Electromagnetic stirring (EMS) is used to fabricate a semi-solid slurry. A thin plate is formed by injecting the slurry into the forging die. When the punch speed used to compress the slurry is low, turbulent flow occurs. When the punch speed is high, laminar flow occurs, and the solid and liquid phases move simultaneously. For a pressure of 150 MPa or below, incomplete filling behavior and cracks occur. For a pressure of 200 MPa or above, a durable formed product can be obtained. However, the differences between the mechanical properties according to the application of EMS and pressure are slight. The microstructure of the slurry without EMS has an unclear distinction between the liquid phase and solid phase. However, the microstructure of the thin plates formed by using this slurry has a clear distinction between the liquid and solid with respect to the spheroid shapes. The tensile strength and elongation for a thin plate formed with a punch speed of 300 mm/s and pressure of 250 MPa with EMS slurry are 169 MPa and 11.0 pct, respectively. After T6 heat treatment, the tensile strength improves to 305 MPa.     

Semiconductor performance of rare earth gadolinium-doped aluminum–zinc oxide thin film

Rare earth element gadolinium-doped aluminum–zinc oxide(Gd–AZO) semiconductor thin film material was deposited on both silicon and glass substrate by radio frequency(RF) sputtering at room temperature.Electrical properties and microstructure of Gd–AZO thin film were mainly modulated by altering O2 partial pressure(OPP) during the RF sputtering process.Scanning electron microscope(SEM) and X-ray diffraction(XRD) test were carried out to uncover the microstructure variation trend with the sputtering OPP,and amorphous structure which is beneficial to large mass industry manufacture was also demonstrated by the XRD pattern.Transmittance in visible light spectrum implies the potential application for Gd–AZO to be used in transparent material field.Finally,bottom gate,top contact device structure thin film transistors(TFTs) with Gd–AZO thin film as the active channel layer were fabricated to verify the semiconductor availability of Gd–AZO thin film material.Besides,the Gd–AZO TFTs exhibit preferable transfer and output characteristics.     

Commercial process for mass production of synthetic natural gas through the adiabatic reactors: operational characteristics of a 50‐kW pilot‐plant,influence of steam,and CO2

In synthetic natural gas (SNG) reaction process, the water gas shift (WGS) reaction and methanation reaction take place simultaneously, and an insufficient supply of steam might deactivate the catalyst. In this study, the characteristics of the methanation reaction with a commercial catalyst and using a low [H₂]/[CO] mole ratio in SNG synthesis are evaluated. The reaction characteristics at various possible process parameters are evaluated varying different process parameters such as the [H₂O]/[CO] mole ratio, [H₂]/[CO] mole ratio, flow of different % CO₂, and reaction temperature. Temperature profiles on catalyst bed are monitored as a function of the [H₂O]/[CO] mole ratio, [H₂]/[CO] mole ratio, and flow of different % CO₂. Through a lab‐scale optimization process, suitable optimum conditions are selected and in the same condition a 50‐kW pilot‐scale SNG production process through adiabatic reactors is carried out. The pilot scale SNG reaction is stable through overnight and the CO conversion efficiency and CH₄ selectivity are 100% and 97.3%, respectively, while the maximum CH₄ productivity is 0.654 m³/kg_cat · h. Copyright © 2016 John Wiley & Sons, Ltd.     

A mixed phase lanthanum vanadate in situ induced by graphene oxide/graphite carbon nitride for efficient photocatalytic hydrogen generation

A mixed phase LaVO₄ with high dispersion was in situ induced and implanted in graphene oxide-graphite carbon nitride composite. The obtained nanocomposite (GO–C₃N₄–LaVO₄) showed high and stable photocatalytic activity for hydrogen evolution, which significantly benefited from the improved charge separation and light absorption in the special composite photocatalyst as evidenced by UV–vis spectra, fluorescence spectrum, photocurrent response and electrochemical impedance. The fabrication strategy of mixed phase LaVO₄ in the GO-C₃N₄ provides a new idea for constructing cheap and active organic-inorganic semiconductor photocatalysts for hydrogen generation.     

Broadband circularly polarized patch antenna with gap‐coupled feed and resistor loading

A broadband circularly polarized patch antenna with suspended structure is proposed. The suspended patch has a bow‐tie structure and a gap‐coupled feed. By connecting a resistor load to another gap‐coupled feed port at the opposite position, a wide impedance and axial ratio (AR) bandwidths are obtained. The proposed design has a very simple antenna structure with an impedance bandwidth of 44.5% and a 3‐dB AR bandwidth of 33.8%, respectively. The results show that the bandwidth of the patch antenna is successfully broadened using the suspended configuration, gap‐coupled feed, and resistor loading. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:587–593, 2014.     

Optimal and Elastic Energy Trading for Green Microgrids: a two-Layer Game Approach

Mobile Networks and Applications - Energy trading mechanism for microgrids has an inherent two-layer architecture, in which the energy trading at the first layer is between a microgrid aggregator...     

Colloidal synthesis of Gd<Superscript>3+</Superscript> doped ZrO<Subscript>2</Subscript> based dielectrics and their structural and electrochemical property studies

Solution processed wide band gap dielectrics have nowadays started to receive renewed interest for practical application in semiconductor electronics. In this regard, undoped and gadolinium (Gd) doped zirconia (ZrO₂) nanocrystallites were colloidally processed and their potential for dielectric applications has been demonstrated. X-ray diffraction measurements revealed the effective crystallization of nanostructures and the successful substitution of Gd ions into the cubic ZrO₂ matrix. The particulate-like characteristics of undoped and Gd doped ZrO₂ nanostructures were examined through the electron microscopes, which hardly revealed any difference among them. The optical band gap of ZrO₂ nanostructures was determined to be around 4.64–4.80 eV from the absorbance measurements. The potential of Gd doped ZrO₂ nanostructures for dielectric functions were evaluated through electrochemical impedance spectroscopic measurements. The improved capacitance values estimated from the Nyquist plots suggests the potential of the investigated materials for low power and low voltage electronic applications.