Thin reduced graphene oxide interlayer with a conjugated block copolymer for high performance non-volatile ferroelectric polymer memory

Polymer ferroelectric-gate field effect transistors (Fe-FETs) employing ferroelectric polymer thin films as gate insulators are highly attractive as a next-generation non-volatile memory. For minimizing gate leakage current of a device which arises from electrically defective ferroelectric polymer layer in particular at low operation voltage, the materials design of interlayers between the ferroelectric insulator and gate electrode is essential. Here, we introduce a new solution-processed interlayer of conductive reduced graphene oxides (rGOs) modified with a conjugated block copolymer, poly(styrene-block-paraphenylene) (PS-b-PPP). A FeFET with a solution-processed p-type oligomeric semiconducting channel and ferroelectric poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) insulator exhibited characteristic source–drain current hysteresis arising from ferroelectric polarization switching of a PVDF-TrFE insulator. Our PS-b-PPP modified rGOs (PMrGOs) with conductive moieties embedded in insulating polymer matrix not only significantly reduced the gate leakage current but also efficiently lowered operation voltage of the device. In consequence, the device showed large memory gate voltage window and high ON/OFF source–drain current ratio with excellent data retention and read/write cycle endurance. Furthermore, our PMrGOs interlayers were successfully employed to FeFETs fabricated on mechanically flexible substrates with promising non-volatile memory performance under repetitive bending deformation.     

Optimum step length selection rule in modified HL–RF method for structural reliability

This paper presents the implementation concepts of a step length selection rule in a modified Hasofer-Lind and Rackwitz-Fiessler (HL–RF) method in order to improve its performance. Several step length selection rules in the context of structural reliability were studied and implemented in order to make the modified HL–RF method more robust and efficient. It has been demonstrated that a variant of Goldstein's rule, which is popularly known as the Armijo rule, is one of the most efficient step length selection rules. It is observed in this study that a proper step length selection rule will not only make the algorithm more robust but also improves the other parameters such as efficiency, capacity, etc. An iterative procedure, which enables systematic implementation into a computer program has been given. Several case studies have been taken from the literature to demonstrate and validate the proposed algorithm. A general-purpose software has been developed to solve a variety of structural reliability problems including those, which are complex and non-linear. In addition, non-normal distributions, such as lognormal, extreme value distributions, etc., are incorporated in this software.     

Fabrication of zinc‐loaded hollow glass microspheres (HGMs) for hydrogen storage

The greatest challenge for a feasible hydrogen economy lies on the production of pure hydrogen and the materials for its storage with controlled release at ambient conditions. Hydrogen with its great abundance, high energy density and clean exhaust is a promising candidate to meet the current global challenges of fossil fuel depletion and green house gases emissions. Extensive research on hollow glass microspheres (HGMs) for hydrogen storage is being carried out world‐wide, but the right material for hydrogen storage is yet underway. But many other characteristics, such as the poor thermal conductivity etc. of the HGMs, restrict the hydrogen storage capacity. In this work, we have attempted to increase the thermal conductivity of HGMs by ZnO doping. The HGMs with Zn weight percentage from 0 to 10 were prepared by flame spheroidization of amber‐colored glass powder impregnated with the required amount of zinc acetate. The prepared HGMs samples were characterized using field emission‐scanning electron microscope (FE‐SEM), environmental SEM (ESEM), high‐resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy and X‐ray diffraction (XRD) techniques. The deposition of ZnO on the microsphere walls was observed using FE‐SEM, ESEM and HRTEM which was further confirmed using the XRD and ultraviolet–visible absorption data. The hydrogen storage studies done on these samples at 200 °C and 10‐bar pressure for 5 h showed that the hydrogen storage increased when the Zn percentage in the sample increased from 0 to 2%. The percentage of zinc beyond 2, in the microspheres, showed a decline in the hydrogen storage capacity. The closure of the nanopores due to the ZnO nanocrystal deposition on the microsphere surface reduced the hydrogen storage capacity. The hydrogen storage capacity of HAZn2 was found 3.26 wt% for 10‐bar pressure at 200 °C. Copyright © 2015 John Wiley & Sons, Ltd.     

Acidogenic hydrogen production from wastewater: Process analysis with the function of influencing parameters

Current communication reports the application of kinetic models viz., modified Gompertz, modified Logistic, Ratkowsky and Andrew model to study the acidogenic hydrogen (H₂) production along with volatile fatty acids (VFA) production and substrate degradation from various wastewater (dairy, distillery, chemical and designed synthetic wastewater) using mixed consortia. Influence of fermentation time was specifically evaluated by modified Gompertz and modified Logistic models on H₂ and VFA production. Influence of system redox condition on process was evaluated by Ratkowsky and Andrew models. The modified Gompertz model showed best fit for H₂ production as well as substrate degradation while modified Logistic model showed good acceptability with VFA production. The Andrew model describes both H₂ and VFA production with respect to system redox condition relatively well. This information provides an understanding of the process behavior, which can help in the design and upscaling of the process for efficient H₂ production. Copyright © 2015 John Wiley & Sons, Ltd.     

太阳能电池生产线中新型等离子体刻蚀机刻蚀工艺探讨

介绍了一种新型等离子体刻蚀机的使用条件,通过对各种参数变化的组合实验,得到了最佳工艺数据.利用该刻蚀机生产的电池片刻蚀效果好,刻蚀后经检测,电池片漏电流小,并联电阻大,提高了电池片的综合性能指标.     

Emission and performance study emulsified orange peel oil biodiesel in an aspirated research engine

This study paves the way on reducing smoke emission and NO_x emissions of research diesel engine by detailing the effect of water addition in biodiesel. Fuel samples were prepared with different concentrations of water in orange peel oil biodiesel (94% waste orange peel oil biodiesel + 4% water + 2% Span 80 (WOPOBDE1) and 90% waste orange peel oil biodiesel + 8% water + 2% Span 80 (WOPOBDE2). Span 80 was employed as a nonionic surfactant, which emulsifies water in biodiesel. Experimental results revealed that the nitrogen oxides and smoke emission of orange peel oil biodiesel emulsion were reduced by 11%–19% and 3%–21%, respectively, compared to that of neat orange peel oil biodiesel (WOPOBD). In addition, the introduction of orange peel oil–water emulsions in the diesel engine considerably reduced the emissions of unburned hydrocarbons and carbon monoxide. The overall hydrocarbon emission of WOPOBDE2 was 12.2% lower than that of WOPOBD and 16.3% lower than that of diesel. The overall CO emission of WOPOBDE2 was 17% lower than that of base fuel (WOPOBD) and 21.8% lower than that of diesel. Experimental results revealed that modified fuel had higher brake thermal efficiency and lower brake specific fuel consumption than that of base fuel at all engine brake power levels.     

替换机械式开关的单IC基电子电路

简单廉价电路使用一个低成本按键开关就可以触发电源的开关.该电路可替换更高价格及外形较大的按键式机械开关.按键开关触发一个单稳电路.