Application of Taylor series in obtaining the orthogonal operational matrix

In this research first we explicitly obtain the relation between the coefficients of the Taylor series and Jacobi polynomial expansions. Then we present a new method for computing classical operational matrices (derivative, integral and product) for general Jacobi orthogonal functions (polynomial and rational). This method can be used for many classes of orthogonal functions.     

W-CDMA capacity and planning issues

Third generation (3G) mobile networks are due to become reality in the next few years as governments world-wide start to auction or `release' new spectrum to new and existing cellular operators. A major differentiation of 3G over second generation networks is the provision of multiple-data-rate services, higher spectrum efficiency and greater flexibility of the air interface. This paper addresses FDD W-CDMA planning and capacity estimation issues. As well as addressing the planning steps, link budgets and simplistic uplink capacity estimation the paper goes into more detail on simulation methods and considerations. Finally an example W-CDMA network, based on realistic site locations in central London, is provided. Capacity estimations are given with some indications of network stability and operating points     

Exploring the dynamics of project management office and portfolio management co-evolution: A routine lens

This paper addresses a recurrent topic of organizational project management (OPM) research: Project Management Offices (PMOs) are perceived to be instrumental in implementing strategy through portfolios of projects, but empirical evidence also shows that PMOs are often short-lived and their value is hard to quantify. We argue that an explanation may lie in the processes of co-evolution that PMOs undergo over time in interaction with organizational capabilities and context. We adopt an innovative research frame in the context of OPM research, using process theories of change and routines as a lens to investigate the co-evolution of PMO and Portfolio Management. A conceptual framework is suggested and we use an empirical case study to test and refine it. We discuss the theoretical implications of the findings and highlight the contributions made in supporting, adding, articulating and contrasting extant literature. We conclude the paper underlining paths for further researches.     

Tin(II)-quercetin complex: Synthesis, spectral characterisation and antioxidant activity

The complex formation between quercetin (Q) and stannous chloride (SnCl₂·2H₂O) was studied using UV-visible, IR and ¹H NMR spectroscopic techniques. Spectroscopic data suggest that Q can chelate stannous cations through both 3-hydroxy-4-carbonyl and the 3′,4′-dihydroxyl (catechol) chelation sites. The antioxidant activity of the complex was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis 3-ethylbenzothiazoline-6-sulphonic acid (ABTS) diammonium salt and ferric reducing antioxidant power (FRAP) methods. It was shown that radical scavenging activity and ferric reducing potential of free Q was decreased after chelation of stannous cation.     

Investigation of CNT modification of epoxy resin in CFRP strengthening systems

The use of carbon fiber‐reinforced polymers (CFRPs) to reinforce old structures has become popular in recent years. In this study, the chemical structure of the epoxy resin used as the bonding agent in the CFRP strengthening system was modified by dispersing multi‐walled carbon nanotubes (MWCNTs) in order to improve the performance of the strengthening system. Composites were fabricated with different mixing orders employing the solvent‐assisted dispersion method and ultrasonic mixing. Thermogravimetric analysis, dynamic mechanical analysis, and tensile tests were conducted to investigate the effect of CNT dispersion and fabrication method on the thermal and mechanical properties of epoxy composite. In addition, the temperature‐dependent tensile behavior of fabricated composites was studied by performing tensile tests at elevated temperatures. The morphology of CNT/epoxy composites was characterized using scanning electron microscopy (SEM). Fourier transform infrared (FTIR) was also used to show the influence of solvent on the molecular structure of composites. Based on the experimental results, the decomposition temperature of the epoxy resin was heightened by 15°C as a result of solvent‐assisted dispersion of nanotubes. However, the glass transition temperature (T_g) was slightly reduced due to the solvent effect. FTIR analysis revealed that the solvent negatively affects the curing process of epoxy composite. A considerable enhancement was recorded in the tensile properties as a result of CNT infusion. This was attributed to the homogeneous dispersion of nanotubes which was shown by SEM images. Using solvent to disperse nanotubes led to the reduction of tensile strength of the epoxy composite at elevated temperature due to the lower T_g. POLYM. COMPOS. 37:1021–1033, 2016. © 2014 Society of Plastics Engineers