Microstructure of the deep level defect E1/E2 in 6H silicon carbide (Abstract)

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An accurate account of mass loss during cheese ripening described using the reaction engineering approach (REA)-based model

Cheese ripening is an important step in cheese making for modifying surface and curd properties. Due to physical, chemical and biological changes, mass loss usually occurs during the process. Although these changes are essential for developing the texture and flavour of cheese, mass loss decreases product yields. A reliable mathematical model is used to quantify mass loss during cheese ripening so that the processing conditions can be fine-tuned to achieve the desirable throughput. In this study, for the first time, the reaction engineering approach (REA)-based model is applied to model the cheese ripening. The study shows that the REA-based model is accurate to model cheese ripening of Camembert and French smear cheese. In addition, the REA is able to model the cheese ripening under time-varying environmental conditions. For this purpose, the equilibrium activation energy is evaluated according to the corresponding humidity and temperature in each period, while the same relative activation energy for ripening under constant environmental conditions is implemented. The REA is a simple yet effective approach to model the simultaneous heat and mass transfer process accompanied by chemical and biological reactions. Considering its effectiveness, the REA can be applied in industrial settings for predicting mass loss during cheese ripening

Experimental study and modeling of the influence of screw dislocations on the performance of Au/n-GaN Schottky diodes

The influence of screw dislocations on the performance of Au/n-GaN Schottky diodes was investigated. The current-voltage (I-V) characteristics of the diodes fabricated on different GaN templates grown by metallorganic chemical vapor deposition on sapphire substrates were studied. It was shown that these dislocations result in the lowering of the barrier height in the localized regions.published_or_final_versio

Improved performance by using TaON/SiO2 as dual tunnel layer in Charge-Trapping nonvolatile memory

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Deep level transient spectroscopy study of particle irradiation induced defects in n-6H-SiC (Abstract)

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Spatial distribution of carrier concentration in un-doped GaN film grown on sapphire (Abstract)

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Acceptors in undoped gallium antimonide

Undoped GaSb materials were studied by temperature dependent Hall (TDH) measurements and photoluminescence (PL). The TDH data reveals four acceptor levels (having ionization energies of 7meV, 32meV, 89meV and 123meV) in the as-grown undoped GaSb samples. The 32meV and the 89meV levels were attributed to the GaSb defect and the VGa-related defect. The Ga Sb defect was found to be the important acceptor responsible for the p-type nature of the present undoped GaSb samples because of its abundance and its low ionization energy. This defect was thermally stable after the 500°C annealing. Similar to the non-irradiated samples, the 777meV and the 800meV PL signals were also observed in the electron irradiated undoped GaSb samples. The decrease of the two peaks' intensities with respect to the electron irradiation dosage reveals the introduction of a non-radiative defect during the electron irradiation process, which competes with the transition responsible for the 777meV and the 800meV PL peaks.published_or_final_versio

Identification of regions in a spray dryer susceptible to forced agglomeration by CFD simulations

Agglomeration during spray drying improves the rehydration and flow properties of produced powders. However, tools for predicting agglomeration are rare. In this work a rigorous mapping approach incorporating number density and stickiness state of particles was developed for CFD simulations, which identifies different zones prone to coalescence and agglomeration inside a spray dryer. This approach was found to be quick, informative, reasonably accurate and resource efficient, as it bypasses the modelling of collision phenomena. The predictions were validated with experimental data of particle size distribution and SEM analyses of the powder morphology performed on samples produced in a lab-scale counter current spray dryer with varying two-nozzle- configurations. For the investigated dryer, the optimum nozzle configuration to achieve effective agglomeration was successfully identified and configurations yielding size enlargement dominated by coalescence could be distinguished. The developed method is generic and hence can be applied to find suitable location and angle for multiple atomization as well as fine returns in industrial practice to achieve controlled agglomeration. This study forms the fundament of a rigorous CFD model for agglomeration, which along with the findings from this study will allow the agglomeration phenomenon to be better understood and thus attain more efficient design, scale-up and operation of spray dryers

Dynamic Functions of RhoA in Tumor Cell Migration and Invasion

RhoA is one of the more extensively studied members of the Rho family of small GTPase where it is most readily recognized for its contributions to actin-myosin contractility and stress fiber formation. Accordingly, RhoA function during cell migration has been relegated to the rear of the cell where it mediates retraction of the trailing edge. However, RhoA can also mediate membrane ruffling, lamellae formation and membrane blebbing, thus suggesting an active role in membrane protrusions at the leading edge. With the advent of fluorescence resonance energy transfer (FRET)-based Rho activity reporters, RhoA has been shown to be active at the leading edge of migrating cells where it precedes Rac and Cdc42 activation. These observations demonstrate a remarkable versatility to RhoA signaling, but how RhoA function can switch between contraction and protrusion has remained an enigma. This review highlights recent advances regarding how the cooperation of Rho effector Rhotekin and S100A4 suppresses stress fiber generation to permit RhoA-mediated lamellae formation

Deep level transient spectroscopic study of neutron-irradiated n-type 6H-SiC

A study of neutron-irradiated n-type 6H-SiC using deep level transient spectroscopy was presented. 100- 1600°C isochronal annealing was performed on the as-irradiated samples with each of the annealing steps to investigate the thermal annealing behavior. Thermal generation of deep levels NE1- NE4 at annealing temperatures above 1400°C was observed.published_or_final_versio