Fast response ultraviolet Ga-doped ZnO based photoconductive detector

A metal-semiconductor-metal photoconductive detector was fabricated using high quality Ga-doped ZnO film epitaxially grown onto alumina substrate by spray pyrolysis. The photocurrent increases linearly with incident power density for more than two orders of magnitude. Reflectance and photocurrent measurements were carried out to study optoelectronic properties of Ga-doped ZnO thin film. Both spectra are consistent with each other showing good response in UV than visible region. Peak responsivity of about 1187 A/W at 5 V bias for 365 nm light was obtained in UV region.     

Composite polymeric microsponge-based long-acting gel formulation for topical delivery of mupirocin

Topical delivery of medicaments in a controlled manner is still a promising area of research. Drug-containing dammar gum-ethyl cellulose composite microsponge loaded gel formulation (D-MSPG) was developed for controlled topical delivery of mupirocin. The drug-loaded microsponges (D-MSPs) were formulated by the quasi-emulsion solvent diffusion method and were evaluated for morphology, particle size distribution, entrapment efficiency, thermal properties, and crystallinity. The optimized D-MSPs (entrapment efficiency 91.5 ± 4.0% and particle size of 55.15 ± 2.9 μm) were dispersed in carbopol 934 gel (D-MSPG). The final product was characterized for pH, viscosity, texture, spreadability, consistency, syneresis, in vitro drug release, and ex vivo skin penetration study. A comparative study with marketed formulation was performed. For optimized gel formulation (G4), drug content was 104.19 ± 1.68%, and drug release was 84.19% after 24 h. The pH of the optimized gel was observed to be 6.05 ± 0.04. Viscosity of the optimized gel formulation was found to be 1212.15 ± 434.85 mPa-s at 50 s⁻¹. The steady-state flux (J) in ex vivo skin permeation was observed to be 53.96 μg cm⁻² h⁻¹ and the permeability coefficient was 2.69 cm/h for the optimized gel formulation. According to the findings, the D-MSPG-based formulation strategy can act well to prolong the topical delivery of mupirocin or similar drug molecules.     

Spin synthesis of monolayer of SiO2 thin films

The highly ordered monolayer of submicron size silica (SiO₂) particles (235 nm) is developed on p-silicon by using three-step spin-coating in colloidal suspension, which has significant potential in various applications. The influence of three-step spin speeds, spinning time, acceleration time between different steps, concentration of SiO₂ particles in the solution, solution quantity, and the ambient humidity (relative humidity) on the properties of monolayer SiO₂ are studied in order to achieve a large area monolayer film. A relatively high surface coverage and uniform monolayer film of SiO₂ particles in the range of 85%-90% are achieved by appropriate control of the preparative parameters. We conclude that this method can be useful in industrial applications, because of the fabrication speed, surface coverage and cost of the process.     

Robust stability of nonlinear model predictive control based on extended Kalman filter

This work deals with state estimation and process control for nonlinear systems, especially when nonlinear model predictive control (NMPC) is integrated with extended Kalman filter (EKF) as the state estimator. In particular, we focus on the robust stability of NMPC and EKF in the presence of plant-model mismatch. The convergence property of the estimation error from the EKF in the presence of non-vanishing perturbations is established based on our previous work [1]. In addition, a so-called one way interaction is shown that the EKF error is not influenced by control action from the NMPC. Hence, the EKF analysis is still valid in the output-feedback NMPC framework, even though there is no separation principle for general nonlinear systems. With this result, we study the robust stability of the output-feedback NMPC under the impact of the estimation error. It turns out the output-feedback NMPC with EKF is Input-to-State practical Stable (ISpS). Finally, two offset-free strategies of output-feedback NMPC are presented and illustrated through a simulation example.     

Placement and routing in 3D integrated circuits

Three-dimension technologies offer great promise in providing improvements in the overall circuit performance. Physical design plays a major role in the ability to exploit the flexibilities offered in the third dimension, and this article gives an overview of placement and routing methods for FPGA- and ASIC-style designs. We describe CAD techniques for placement and routing in 3D ICs, developed under our 3D analysis and design optimization framework. These approaches address a dichotomy of design styles, both FPGA and ASIC. The factors that are important in each style are different, so that a one-size-fits-all approach is impractical, and therefore, we present separate approaches for 3D physical design for each of these technologies. Hence, our FPGA placement method uses a two-step optimization process that minimizes inter-tier vias first, followed by further optimization within and across tiers. In contrast, the ASIC flow uses cost function weighting to discourage, but not minimize, inter-tier crossings.     

Synthesis of cyclic carbonates from carbon dioxide and epoxides using alkali metal halide supported liquid phase catalyst

Using combination of Mn–Co transition metal species with N-hydroxyphthalimide as a catalyst for one-step oxidation of cyclohexane with molecular oxygen in acetic acid at 353 K can give more than 95% selectivity towards oxygenated products with adipic acid as a major product at a high conversion (ca. 78%). A turnover number of 74 for this partial oxidation are also recorded.     

Palladium/Carbon Catalyzed Hydrogen Transfer Reactions using Magnesium/Water as Hydrogen Donor

Results on nonlinear phenomenon (NLP) in the liquid phase hydrogenation of methyl benzoylformate (MBF) and pyruvaldehyde dimethyl acetal (PA) on chiral Pt-cinchona catalyst are reported for the first time (enantiomeric excess 90–95%). The new data support the conclusions of the NLP studies on ethyl pyruvate (EP) and ketopantolactone (KPL). Namely, the order of the adsorption strengths of the parent cinchona alkaloids are: CD > CN > QN ~ QD and the results of the NLP measurements indirectly verify the so-called 1:1 model of enantioselection. The new data, however, call attention to a new, substrate and modifier dependent phenomenon, which necessitates further experiments for a better understanding of the mechanism of the Orito reaction.     

Studies on Dehydration of Sapota (Achras zapota)

Sapota (Achras zapota) is a tropical fruit found in several parts of India. It is one of the most popular fruits besides mango, custard apple, and several others. Once ripe, it needs to be consumed within a couple of days due to the highly perishable nature of this exquisite fruit variety. The best way to increase the shelf-life is through the process of dehydration of peeled sapota. In the present study, the convective air drying of sapota pulp was carried out and compared with low-temperature drying techniques such as heat pump-assisted drying and freeze drying. The sapota paste was dried in a convective dryer to study the effect of operating parameters such as air temperature and air velocity. In addition, the effect of additives such as oat and wheat fibers and the paste thickness on drying was also studied. The critical analysis of dehydrated sapota was carried out in terms of water activity, sugar content, color, and rehydration ratio. The drying data were analyzed using Page's model and Newton's model on the basis of root mean square error (RMSE), reduced χ square (χ²) and correlation coefficient (R²).