Comparative Study of HgCdTe Etchants: An Electrical Characterization

A comparative study of wet etchants for both molecular beam epitaxy (MBE) and liquid phase epitaxy (LPE) grown n- and p-type samples was performed using capacitance–voltage (C–V) characteristics and surface recombination velocity (SRV) extracted from photoconductive decay (PCD) measurements. Different wet etchants were divided in two categories, (i) where bromine is a direct reagent in the etching solution and (ii) where bromine is a byproduct after reaction among different reagents. Negative shift of the flat-band voltages were observed for both n- and p-type samples treated with second category of etchants. A decrease in minority carrier lifetimes and an increase in the surface recombination velocities were also observed for the n-type samples treated with second category of etchants.     

Kinetic effects of silica nanoparticles on thermal and radiation stability of polyolefins

The effects of γ-irradiation as the accelerated degradation procedure were analyzed for the evaluation of material stability. Low density polyethylene, polypropylene and ethylene–propylene terpolymer were studied in formulations with SiO₂ nanoparticles (2 and 5 wt%) or as neat materials. High energy irradiation (up to 100 kGy) has revealed a faster increase in the absorption of carbonyl band in comparison with the corresponding change in hydroperoxide band. The three studied materials present increased oxidation rates as the received energy transferred from incidental rays is enhancing, because the thermal regime of degradation depends on the structural characteristics, namely initial number of tertiary carbon atoms and unsaturation level. The fate of hydroperoxides as oxidation initiators is discussed.     

Microstructure,Surface Characterization,and Electrochemical Behavior of New Ti-Zr-Ta-Ag Alloy in Simulated Human Electrolyte

Metallurgical and Materials Transactions A - A new Ti-20Zr-5Ta-2Ag alloy was elaborated and characterized regarding its microstructure, its native passive film composition and thickness, its...     

C60 Dimers Revisited

Several dimers: C₁₂₀, C₁₄₀, C₁₃₀ and their oxygen-containing derivatives as well as some oligomers or polymers of the well known spherical fullerenes have been synthesized so far. Some of the formulas attributed to such compounds represent the first steps in a more complex fate leading to trivalent capped tubulenes. Such a way could even be followed by functionalized fullerenes. A detailed network transformation is given for C₆₀ and its mono- and di-epoxy derivatives. Semiempirical calculations support the presented findings.     

Synthesis of CuGa2O4 nanoparticles by precursor and self-propagating combustion methods

Copper gallate spinels, CuGa₂O₄, have been synthesized by two wet chemical routes: precursor method and self-propagating combustion involving a glycine-nitrate system. All complex precursors have been characterized by chemical analysis, infrared spectroscopy (IR), ultraviolet visible spectroscopy (UV–vis), electron paramagnetic resonance spectroscopy (EPR), thermal analysis and scanning electron microscopy (SEM). The copper gallate spinel oxides have been further investigated by X-ray diffraction (XRD), SEM, IR, UV–vis, magnetic measurements and EPR. The crystallite size of the copper gallate was found about 280 Å.     

Tailoring porphyrins and chlorins for self-assembly in biomimetic artificial antenna systems

There is much diversity in the way in which photosynthetic organisms harvest sunlight. In chromophore-protein complexes, an exact orientation of pigments by the protein matrix ensures an efficient stepwise energy transfer to the reaction center where charge separation occurs. The charge separation and subsequent electron transfer steps are, however, very similar in all organisms, proving that there must exist a common ancestor. The architectural principle of chromophore-protein complexes is too complicated to be replicated in artificial light-harvesting devices. A simpler principle employs self-assembling chromophores that early green photosynthetic bacteria use in their chlorosomal antenna systems. Efforts in mimicking this self-assembly algorithm with fully synthetic pigments are presented. The fact that, as in the natural system, after self-assembly, concentration quenching is not operating due to the very orderly manner in which the chromophores are positioned lends hope for applications in artificial devices, such as hybrid solar cells.     

Solution‐processed and low‐temperature metal oxide n‐channel thin‐film transistors and low‐voltage complementary circuitry on large‐area flexible polyimide foil

High‐performance solution‐based n‐type metal oxide thin‐film transistors (TFTs), fabricated directly on polyimide foil at a post‐annealing temperature of only 250 °C, are realized and reported. Saturation mobilities exceeding 2 cm²/(Vs) and on‐to‐off current ratios up to 10⁸ are achieved. The usage of these oxide n‐type TFTs as the pixel drive and select transistors in future flexible active‐matrix organic light‐emitting diode (AMOLED) displays is proposed. With these oxide n‐type TFTs, fast and low‐voltage n‐type only flexible circuitry is demonstrated. Furthermore, a complete 8‐bit radio‐frequency identification transponder chip on foil has been fabricated and measured, to prove that these oxide n‐type TFTs have reached already a high level of yield and reliability. The integration of the same solution‐based oxide n‐type TFTs with organic p‐type TFTs into hybrid complementary circuitry on polyimide foil is demonstrated. A comparison between both the n‐type only and complementary elementary circuitry shows the high potential of this hybrid complementary technology for future line‐drive circuitry embedded at the borders of flexible AMOLED displays.     

Sensor‐fault tolerance using robust MPC with set‐based state estimation and active fault isolation

In this paper, a sensor fault‐tolerant control scheme using robust model predictive control (MPC) and set‐theoretic fault detection and isolation (FDI) is proposed. The robust MPC controller is used to control the plant in the presence of process disturbances and measurement noises while implementing a mechanism to tolerate faults. In the proposed scheme, fault detection (FD) is passive based on interval observers, while fault isolation (FI) is active by means of MPC and set manipulations. The basic idea is that for a healthy or faulty mode, one can construct the corresponding output set. The size and location of the output set can be manipulated by adjusting the size and center of the set of plant inputs. Furthermore, the inputs can be adjusted on‐line by changing the input‐constraint set of the MPC controller. In this way, one can design an input set able to separate all output sets corresponding to all considered healthy and faulty modes from each other. Consequently, all the considered healthy and faulty modes can be isolated after detecting a mode changing while preserving feasibility of MPC controller. As a case study, an electric circuit is used to illustrate the effectiveness of the proposed scheme. Copyright © 2016 John Wiley & Sons, Ltd.     

Resource scheduling based on energy consumption for sustainable manufacturing

The paper proposes an agent-based approach for measuring in real time energy consumption of resources in job-shop manufacturing processes. Data from industrial robots is collected, analysed and assigned to operation types, and then integrated in an optimization engine in order to estimate how alternating between makespan and energy consumption as objective functions affects the performances of the whole system. This study focuses on the optimization of energy consumption in manufacturing processes through operation scheduling on available resources. The decision making algorithm relies on a decentralized system collecting data about resources implementing thus an intelligent manufacturing control system; the optimization problem is implemented using IBM ILOG OPL.