Diffused junction p+−n solar cells in bulk GaAs—II: Device characterization and modelling

The photovoltaic characteristics of p⁺-n junction solar cells fabricated on bulk GaAs by an open tube diffusion technique are presented in detail. Quantum efficiency measurements were analyzed and compared to computer simulations of the cell structure in order to determine material parameters such as diffusion length, surface recombination velocity and junction depth. From the results obtained it is projected that proper optimization of the cell parameters can increase the efficiency of the cells to close to 20%.     

A parabolic reflector with asymmetric low sidelobes

A technique for generating low sidelobes on one side of the main lobe for a parabolic reflector antenna is presented. The reflector system that generates such an asymmetric sidelobe pattern consists of a central parabola with two sections of offset parabolas situated at the top and bottom of the central parabola. By adjusting the positions and dimensions of the side reflectors, considerable suppression of the first few sidelobes can be obtained. Further, by similar adjustments it is possible to achieve suppression of sidelobes on both sides of the main beam, though this suppression is relatively less. The technique, though explained in detail with reference to a cylindrical geometry, is extended for a paraboloid of revolution. The analysis program utilized for the optimization of the side reflectors is based on physical optics current integration.     

Thermodynamics study of liquid Cu−Mg alloys by vapor pressure measurements

Metallurgical and Materials Transactions B -     

Rheological properties of rennet casein-whey protein gels prepared at different mixing speeds

The rheological properties at small (oscillatory shear) and large (uniaxial compression) deformations of heat-induced gels (80 °C for 20 min, pH 7.3) containing 25% rennet casein (RCN), 2.5% disodium phosphate and 0%, 2.3% or 6.3% of whey protein isolate (WPI) were measured for samples cooked in a torque-rheometer at mixing speeds within a range of 20–200 rpm (shear rates: ∼15–230 s⁻¹). In addition, microstructure analyses were performed, separately staining RCN and WPI, by Confocal Scanning Laser Microscopy (CSLM). Both small and large deformation tests indicated that increasing addition of WPI prior to the cooking process of RCN resulted in gels exhibiting higher storage and deformability moduli than WPI-free samples. Increasing shear rates during cooking also affected the rheological properties of RCN–WPI gels, and stronger gels were formed as the shear rate during cooking was increased. Despite the data dispersion among replicates, the effect of shear rate on gel strength were evident for RCN gels with 6.3% WPI and relatively clear for gels with 2.3% WPI; however, the trend was uncertain for WPI-free RCN gels. Possible explanations for this observation are that when increasing WPI levels in the presence of RCN and heat, disulfide-thiol exchange reactions between denatured WPI and κ-casein (κ-CN) are increased and possibly promoted by shear rate, resulting in stronger and more cross-linked gel structure. CSLM results were not conclusive to support this hypothesis.     

Quality Characteristic and Shelf Life Studies of Deep-Fried Snack Prepared from Rice Brokens and Legumes By-Product

Legumes and cereal by-product flours were formulated into six of deep-fried snacks, which were evaluated for their physicochemical and sensory properties. Shelf life was analyzed for chemical parameters including: moisture gain, free fatty acid (FFA), and peroxide value (PV) at time intervals of 5 days along with organoleptic evaluation at the beginning and after 5, 10, 15, 20, 25, and 30 days of storage at room temperature (29 ± 2.0 °C) and relative humidity (67 ± 2.5%). A strong negative correlation (−0.83) was observed between the bulk density and the expansion ratio of the products. During storage moisture gain, FFA and PV increased linearly (R ² > 0.92). The results of organoleptic evaluation of all six fried snacks showed that there was no consistent pattern for sensory attributes. The maximum shelf life of the products was 24 days under the storage conditions studied.     

Performance assessment of PID and IMC tuning methods for a mixing process with time delay

A flow process with time delay has been considered for modeling and control. A dilute solution of sodium chloride is used as tracer and an online conductivity measurement unit as sensor and recorder. The objective of the current study is to design control algorithms and present corresponding robust control analysis for the process. The control methodologies considered are (i) conventional PID control and (ii) internal model control (IMC). The control structures are comparatively analyzed using standard robustness measures for stability and performance. Of the two control algorithms, conventional PID and IMC, IMC exhibits faster settling time, no overshoot, better set-point tracking and disturbance rejection, and good robust performance than the PID control scheme.     

Effective Big Data Retrieval Using Deep Learning Modified Neural Networks

Mobile Networks and Applications - In big data, the information retrieval (IR) embraces the discovery of documents from a compilation of dataset which are related to the user query. Usually, the...     

Glycocalyx‐Like Hydrogel Coatings for Small Diameter Vascular Grafts

Novel biological vascular conduits, such as decellularized tissue engineered vascular grafts (TEVGs) are hindered by high thrombogenicity. To mimic the antithrombogenic surface of native vessels with a continuous glycosaminoglycan layer that is present on endothelial cells (ECs), a hyaluronic acid (HA) modified surface is established, to effectively shield blood platelets from collagen‐triggered activation. Using the amine groups present on 4 mm diameter decellularized TEVGs, a continuous HA hydrogel coating is built via a bifunctional thiol‐reactive cross‐linker, thereby avoiding nonspecific collagen matrix cross‐linking. The HA hydrogel layer recreates a luminal wall, “hiding” exposed collagen from the bloodstream. In vitro blood tests show that adhered platelets, fibrinogen absorption, and fibrin formation on HA‐coated decellularized TEVGs are significantly lower than on uncoated decellularized TEVGs. The HA surface also inhibits macrophage adhesion in vitro. HA‐coated decellularized syngeneic rat aortae (≈1.5 mm diameter), and TEVGs in rat and canine models, respectively, are protected from aggressive thrombus formation, and preserve normal blood flow. Re‐endothelialization is also observed. HA‐coated TEVGs may be an off‐the‐shelf small‐diameter vascular graft with dual benefits: antithrombogenic protection and promotion of endothelium.