In Situ Ophthalmic Gel of Ciprofloxacin Hydrochloride for Once a Day Sustained Delivery

This article focuses on preparation and evaluation of a once a day ophthalmic delivery system for ciprofloxacin hydrochloride based on the concept of pH-triggered in situ gelation. The in situ gelling system involves the use of polyacrylic acid (Carbopol® 980NF) as a phase transition polymer, hydroxypropyl methylcellulose (Methocel® K100LV) as a release retardant, and ion exchange resin as a complexing agent. Ciprofloxacin hydrochloride was complexed with ion exchange resin to avoid incompatibility between drug and polyacrylic acid. The developed formulation was stable, and nonirritant to rabbit eyes and in vitro drug release was found to be around 98% over a period of 24 hours.     

Computational fluid dynamics modeling of hydrogen production in an autothermal reactor: Effect of different thermal conditions

A numerical model was developed and validated to simulate and improve the reforming efficiency of methane to syngas (CO+H₂) in an autothermal reactor. This work was undertaken in a 0.8 cm diameter and 30 cm length quartz tubular reactor. The exhaust gas from combustion at the bottom of reactor was passed over a Ru/γ-Al₂O₃ catalyst bed. The Eddy Dissipation Concept (EDC) model for turbulence-chemistry interaction in combination with a modified standard k-? model for turbulence and a reaction mechanism with 23 species and 39 elementary reactions were considered in the combustion model. The pre-exponential factors and activation energy values for the catalyst (Ru) were obtained by using the experimental results. The percentage of difference between the predicted and measured mole fractions of the major species in the exhaust gas from combustion and catalyst bed zones was less than 5.02% and 7.73%, respectively. In addition, the results showed that the reforming efficiency, based on hydrogen yield, was increased with increase in catalyst bed’s thermal conductivity. Moreover, an enhancement of 4.34% in the reforming efficiency was obtained with increase in the catalyst bed wall heat flux from 0.5 to 2.0 kW/m².     

Experimental and modeling of CO2 capture by dry sodium hydroxide carbonation

In this work, CO₂ capture from the air using dry NaOH sorbents has been studied. The influences of the main operating parameters such as temperature, air humidity, and NaOH loading on the CO₂ removal rate have been experimentally investigated using Taguchi method. The results revealed that the appropriate value of the temperature to maximize the rate was in the range of 35–45 °C. A multilayer artificial neural network (ANN) was also used to model the process in order to find the optimal conditions. A procedure reported in the literature was modified and applied to design the ANN model. The model predictions were validated by conducting some more experiments. The experimental results proved the accuracy of the model to predict the optimal conditions. The effects of NaOH particle size and multiple carbonation cycles have also been investigated.     

Spatial Mode Division Multiplexing for High Speed Optical Coherent Detection Systems

Spatial mode-division multiplexing is emerging as a potential solution to further increasing optical fiber capacity and spectral efficiency. We report a dual-mode, dual-polarization transmission method based on mode-selective excitation and detection over a two-mode fiber. In particular, we present 107 Gbit/s coherent optical OFDM (CO-OFDM) transmission over a 4.5 km two-mode fiber using LP01 and LP11 modes in which mode separation is performed optically.     

FTIR-ATR Spectroscopy Based Metabolite Fingerprinting as A Direct Determination of Butter Adulterated With Lard

Adulteration of butter with cheaper animal fats, such as lard, has become an issue in recent years. A simple and rapid analytical method of attenuated total reflectance in Fourier transform infrared spectroscopy was developed in order to determine the lard content in butter. The multivariate calibration of partial least square model for the prediction of adulterant was developed for quantitative measurement. The model yielded the highest regression with the correlation coefficient (R²) = 0.999, its lowest root mean square error estimation = 0.0947, and its root mean square error prediction = 0.0687, respectively. Cross validation testing evaluates the predictive power of the model. Partial least square model to be effective as their intercept of R²Y and Q²Y were 0.08 and –0.34, respectively.     

Effects of post-drying methods on pomelo fruit peels

Process conditions of alkali refining, bleaching, and deodorization of crude chufa oil extracted from chufa (Cyperus esculentus L.) tubers grown in Korea were optimized to obtain an edible grade vegetable oil. The overall scope of refining conditions was similar to other vegetable oils. The degumming process, however, could be omitted since phospholipids were removed during alkalirefining and bleaching processes. RBD (alkali-refined, bleached, and deodorized) chufa oil fully satisfied Korean quality standards for edible vegetable oil. Chufa oil contained a high level of oleic acid, along with palmitic acid and linoleic acid. Physicochemical properties of chufa oil were similar to olive oil. The order of oxidative stability of chufa oil was crude>deodorized>degummed>refined>bleached oil. RBD chufa oil was virtually colorless and bland tasting, and was considered suitable for edible purposes.     

A multi-criteria decision-making approach to solve the product mix problem with interval parameters based on the theory of constraints

The product mix problem is one of the most important problems in production systems. Several algorithms to determine the product mix under the theory of constraints have been developed. Most of the previous works focused on one bottleneck (dominant bottleneck) and considered the product mix problem with exact data. In this paper, all bottlenecks are used in order to determine the aggregated priority of each product, and a multi-criteria decision-making approach is proposed for product mix problem with interval parameters. The proposed approach involves bottlenecks identification, determination of the production priority and the weights vector of bottlenecks, application of interval TOPSIS to calculate the aggregated priority of each product, and use of reducing and increasing process to improve the production plan. At the end, a numerical example is presented to illustrate the procedure of the proposed approach. The results obtained from the computational study have shown that the proposed algorithm is an effective approach to solve the product mix problem.