Microwave synthesis and spectroscopic studies of some complex compounds as pigments and their applications in paints

Metal complex pigments have been widely used for various applications such as pigments in coatings. This work presents the use of microwave technique (Green chemistry) for the synthesis of new copper(II), nickel(II), iron(III), and chromium(III) Schiff base complexes derived from metal salts and Schiff base ligand. Also, the microwave technique was used in the synthesis of Schiff base ligand which is derived from selected amine, namely methoxy-tolidine, and selected aldehyde, namely 2-hydroxynaphthaldehyde. The prepared ligand and metal complex pigments were characterized by elemental analysis, NMR, spectral UV–Vis, infrared, and thermal gravimetric analysis. The physical and mechanical properties and corrosion resistance of dry paint films were also examined. The obtained results revealed that the prepared metal complex pigments showed excellent mechanical and corrosion resistance.     

Improving Design Coordination for Building Projects. I: Information Model

Detailed design of building projects is a complex multidisciplinary process highly dependent upon effective aggregation of individual designs to produce a coherent set of final design documents. Throughout the detailed design process, changes are frequently introduced and need to be properly managed among the various members of the design team. This paper presents an information model for storing design information, recording design rationale, and managing design changes. The proposed model is built around a central library of generalized building components that can be used to describe a complete building project hierarchy. Each component allows the designer to store desired performance criteria and related design rationale. Each component is also sensitive to its own changes and automatically communicates such changes to affected parties through preset communication paths. The model, as such, provides improved design coordination and control over changes, thus helping to increase the consistency and productivity of the overall design process. Conceptual details of the model are described in this paper, and model implementation into a collaborative design system is presented in a companion paper.     

Hydrodynamics and flow regime transition study of trickle bed reactor at elevated temperature and pressure

The hydrodynamics in a trickle bed reactor (TBR) in non-ambient conditions are studied for air-water and air-acetone (pure organic liquid of low surface tension) systems. A flow map experiments for air-water and air-acetone systems are performed in a pilot plant reactor of 0.05 m i.d. and 1.25 m height. It has been demonstrated from the experimental results that the pressure drop tends to increase with increasing superficial gas and liquid velocity and reactor pressure, while it tends to decrease with increasing bed temperature. The results also show that the dynamic liquid holdup increases with increasing liquid velocity and decreases with increasing superficial gas velocity, reactor pressure and bed temperature. The dynamic liquid holdup and pressure drop values are obviously higher than those measured for air-water system at the same fluid fluxes, reactor pressure and bed temperature due to the surface tension effects. For higher reactor pressure and temperature, the trickle to pulse transition boundary shifts towered higher superficial velocities of both gas and liquid.     

Environmental impact assessment of bioplastics production from agricultural crop residues

Clean Technologies and Environmental Policy - Bioplastics are alternatives of conventional petroleum-based plastics. Bioplastics are polymers processed from renewable sources and are biodegradable....     

Real time evaluation of DWT-based high impedance fault detection in EHV transmission

It is possible to capture the required travelling wave information contained in fault transients using wavelet transform. This paper presents practical real time testing for the high impedance fault (HIF) detection algorithm based on real time accidents data. The proposed scheme is implemented for HIF detection in extra high voltage transmission lines. The classifier is based on an algorithm that uses recursive method to sum the absolute values of the high frequency signal generated over one cycle and shifting one sample. Characteristics of this scheme are analyzed by extensive real time studies that clearly reveal that this technique can accurately detect HIFs in the EHV transmission lines within only half a cycle from the instant of fault occurrence. The reliability of this scheme is not affected by different fault conditions such as fault distance and fault inception angle.     

Localized pulses exhibiting a missilelike slow decay

We investigate the quasi-missile behavior of known localized wave solutions, such as the modified power spectrum and splash pulses. We demonstrate that source-free localized waves can exhibit slow decay rates analogous to Wu's missile solutions, which are characterized by an amplitude decay rate slower than 1/R over an unlimited range. When excited from a finite aperture, the missilelike decay is not exhibited by all localized waves showing such behavior in the source-free situation. On the other hand, localized wave missiles generated from a finite aperture have peaks that exhibit quasi-missile decay. In an extended intermediate range between the near- and the far-field regions, these pulses decay at a rate slower than 1/R before switching to the usual 1/R decay.     

Application of Plackett–Burman screening design to the modeling of grafted alginate–carrageenan beads for the immobilization of penicillin G acylase

Grafted alginate–carrageenan beads were used to immobilize the industrial enzyme penicillin G acylase (PGA). Sixteen factors were screened with the Plackett–Burman design (PBD) to test their significance on the gel beads formation and enzyme immobilization process. The results of PBD showed a wide variation of 30‐fold in the amount of immobilized penicillin G acylase (iPGA) from 11.9 to 354.16 U/g of beads; this reflected the importance of the optimizing process. Among the 16 tested factors, only 3 were proven to be significant. These factors were the enzyme buffer pH (N), enzyme soaking time (Q) with the gel beads, and enzyme concentration (P). The Pareto chart revealed that both Q and P exerted significant positive effects on the amount of iPGA, whereas N had a negative effect. We recommend further study to optimize only these three significant, distinctive enzyme factors. The PGA covalent attachment to the gel beads were proven by Fourier transform infrared spectroscopy, elemental analysis, and NaCl and reusability tests. The best gel bead formula succeeded in the immobilization of 354.16 U/g of beads and proved to be reusable 14 times, retaining 84% of the initial enzyme activity. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40295.     

Estimation in step-stress accelerated life tests for the exponentiated exponential distribution with type-I censoring

The step-stress accelerated life tests allow the experimenter to increase the stress levels at fixed times during the experiment. The lifetime of a product at any level of stress is assumed to have an exponentiated distribution, whose baseline distribution is a general class of distributions which includes, among others, Weibull, compound Weibull, Pareto, Gompertz, normal and logistic distributions. The scale parameter of the baseline distribution is assumed to be a log-linear function of the stress and a cumulative exposure model holds. Special attention is paid to an exponentiated exponential distribution. Based on type-I censoring, the maximum likelihood estimates of the parameters under consideration are obtained. A Monte Carlo simulation study is carried out to investigate the precision of the maximum likelihood estimates and to obtain the coverage probabilities of the bootstrap confidence intervals for the parameters involved. Finally, an example is presented to illustrate the two discussed methods of bootstrap confidence intervals.     

A prediction system for assessing customer affordability of whole life cycle cost in defence industry

The manufacturing, delivery and support of service contracts in defence aerospace industry require a high financial investment. It is essential that the customer has the financial ability to procure and support the contract from the conceptual and manufacturing phase to the end of the project given the budget constraints. The aim of this paper is to identify the factors that affect customer affordability of defence contracts and develop a customer affordability assessment framework which is implemented as a software prototype system. Two major quantitative factors and twelve qualitative factors were identified, out which seven factors (identified as the major factors) were included within the customer affordability system. Following the identification of factors and development of measures for each, suggested actions to improve customer affordability were also proposed. The research methodology combined both case study and literature review approach with industrial collaboration in the customer affordability system development. The customer affordability system was validated through collaboration with industrial partners and a case study from defence sector and the results showed that the customer affordability system was capable of providing a good assessment of customer affordability.