New oil modified acrylic polymer for pH sensitive drug release:experimental results and statistical analysis

We report results of an experimental study, complemented by detailed statistical analysis of the experimental data, on the development of a more effective control method of drug delivery using a pH sensitive acrylic polymer. New copolymers based on acrylic acid and fatty acid are constructed from dodecyl castor oil and a tercopolymer based on methyl methacrylate, acrylic acid and acryl amide were prepared using this new approach. Water swelling characteristics of fatty acid, acrylic acid copolymer and tercopolymer respectively in acid and alkali solutions have been studied by a step-change method. The antibiotic drug cephalosporin and paracetamol have also been incorporated into the polymer blend through dissolution with the release of the antibiotic drug being evaluated in bacterial stain media and buffer solution. Our results show that the rate of release of paracetamol getss affected by the pH factor and also by the nature of polymer blend. Our experimental data have later been statistically analyzed to quantify the precise nature of polymer decay rates on the pH density of the relevant polymer solvents. The time evolution of the polymer decay rates indicate a marked transition from a linear to a strictly non-linear regime depending on the whether the chosen sample is a general copolymer (linear) or a tercopolymer (non-linear). Non-linear data extrapolation techniques have been used to make probabilistic predictions about the variation in weight percentages of retained polymers at all future times, thereby quantifying the degree of efficacy of the new method of drug delivery.

Travelling waves in a complex Ginzburg-Landau equation with time-delay feedback

One of the simplest ways to create nonlinear oscillations is the Hopf bifurcation. The spatiotemporal dynamics observed in an extended medium with diffusion (e.g., a chemical reaction) undergoing this bifurcation is governed by the complex Ginzburg-Landau equation, one of the best-studied generic models for pattern formation, where besides uniform oscillations, spiral waves, coherent structures and turbulence are found. The presence of time delay terms in this equation changes the pattern formation scenario, and different kind of travelling waves have been reported. In particular, we study the complex Ginzburg-Landau equation that contains local and global time-delay feedback terms. We focus our attention on plane wave solutions in this model. The first novel result is the derivation of the plane wave solution in the presence of time-delay feedback with global and local contributions. The second and more important result of this study consists of a linear stability analysis of plane waves in that model. Evaluation of the eigenvalue equation does not show stabilisation of plane waves for the parameters studied. We discuss these results and compare to results of other models.

Sustainable business:key issues

Sustainable Business: Key Issues is the first comprehensive introductory-level textbook to address the interface between environmental challenges and business solutions to provide an overview of the basic concepts of sustainability, sustainable business, and business ethics. The book introduces students to the background and key issues of sustainability and suggests ways in which these concepts can be applied in business practice. Though the book takes a business perspective, it is interdisciplinary in its nature and draws on knowledge from socio-economic, political, and environmental studies, thereby providing a practical and critical understanding of sustainability in the changing paradigm of global business. It goes beyond the conventional theories of sustainability and addresses critical issues concerned with population, consumption and economic growth. It discusses realistic ways forward, in particular the Circular Economy and Cradle to Cradle frameworks. The book is both a theoretical and practical study guide for undergraduate and postgraduate international students of broad areas of sustainability, teaching ways to recognize opportunities for innovation and entrepreneurship at the intersection of environmental, economic, ethical, and social systems. It takes a strategic approach in applying the power of business methods and policy to address issues of global importance such as climate change, poverty, ecosystem degradation and human rights. This textbook is essential reading for students of business, management and sustainability courses. It is written in an engaging and accessible style, with each chapter including case studies, discussion questions, end of chapter summaries and suggestions for further reading.