Search results

The purpose of this investigation is the evaluation of the inhibitive performance of a new “gemini” surfactant in the series of bis‐quat: N, N, N′, N″, N″‐pentamethyl diethyleneamine‐N, N″‐di‐[tetradecylammonium bromide] on the corrosion of iron in 1 M HCl by gravimetric, potentiodynamic and electrochemical impedance measurements. The effect of the temperature on the corrosion behavior of iron in 1 M HCl without and with inhibitor is studied in the temperature range (298‐333 K). This work also attempts to correlate thermodynamic and kinetic parameters with the inhibition effect.

The inhibition efficiency of gemini synthesized is investigated by weight loss, potentiodynamic polarization and impedance spectroscopy methods.

The synthesized gemini bis‐quat acted as a good inhibitor in 1 M HCl, and inhibition efficiency increased with inhibitor concentration and temperature. Polarization curves showed that the surfactant was a mixed‐type inhibitor in hydrochloric acid. Impedance spectroscopy measurements showed that the inhibitor acted through the formation of a multilayer film at the iron surface. The adsorption of inhibitor on the iron surface obeyed the Langmuir adsorption isotherm equation. The inhibition effect was satisfactorily explained by both thermodynamic and kinetic parameters.

The adsorption of surfactants in the metal surface can markedly change the corrosion resisting property of the metal. So the study of the relation between the adsorption and corrosion inhibition is of a great importance. This was the first attempt to study the inhibition properties of gemini surfactants at the host laboratory.

“A knowledge of different literatures is the best way to free one's self from the tyranny of any of them.” Jose Marti, Cuban writer, poet and statesman.

The authors present the application of the López-Fresno approach in designing an integrated management system (IMS) for an aviation company to the development of an IMS in a government-run organization responsible for the medical evaluation of work disabilities. The purpose of this paper is to share the design process, with the intention of showing that this approach is applicable to other sectors and proposing generalization and applicability strategies to other smaller government entities.

The study involves two phases. Phase I applies the López-Fresno approach to design a basic IMS-I and ends with a European Foundation for Quality Management (EFQM) evaluation, whose suggestions were taken into consideration for the final design of IMS-II during phase II. The data were obtained from the organization's own functioning. There was a significant degree of personal involvement by the authors, external consultants and members of the management committee in areas ranging from the approach itself to the various components analyzed.

The approach led to a better use of human and material resources and produced various advances in both internal and external communication and significant progress in employee motivation in their dealings with users and stakeholders.

The study offers guidelines and recommendations for designing an IMS adapted to small, compact, administrative organizations that operate with stakeholders with highly disparate outlooks and interests, with different quality levels, in a context related to competitiveness and economic development.

This study aims to develop sweet chestnut incorporated corn-based extrudates by the optimization of process conditions.

The independent process variables for extrusion (blend ratio, barrel temperature, screw speed and feed moisture) were investigated to govern their impact on reliant variables, namely, bulk density, specific mechanical energy, water absorption index, water solubility index, color and hardness. Product and system responses were significantly (p < 0.05) affected by the independent variables. Experimental design with quadratic models experienced a high coefficient of determination (R² = 0.99).

Numerical optimization for the development of extrudates resulted in optimum conditions having corn flour: sweet chestnut flour (80:20), barrel temperature (120°C), screw speed (340 rpm) and feed moisture (12%). Fat, moisture and protein contents of the developed extrudates using optimum conditions were significantly (p < 0.05) lower compared to raw materials – corn and sweet chestnut. The packaging of extrudates in aluminum laminates revealed shelf stability of three months at room temperature without deterioration of quality.

Nutritionally rich sweet chestnut extruded products would be an exclusive option to already existing snacks in the market and can facilitate a new sphere in extruded product sector.