Graft copolymers of poly(methyl methacrylate) backbone and poly(propylene oxide-b-ethylene oxide) branches

Summary Two mono-functional macromonomers of poly (propylene oxide-b-ethylene oxide) were synthesized by reaction with methacryloyl chloride. The macromonomers have the same molecular weight and ratio of ethylene oxide and propylene oxide sequences. The reactive methacrylate group can be linked to the ethylene oxide (BuPPOPEO) or to the propylene oxide (BuPEOPPO). These macromonomers showed self-gelling in one week even at low temperature and under a dry atmosphere. Graft copolymers were obtained by reaction of these macromonomers with methyl methacrylate upon free-radical initiation and they were characterized by GPC, VPO, IR and ¹H NMR spectra.     

Mesoscopic analysis of networks with genetic algorithms

The detection of communities is an important problem, intensively investigated in recent years, to uncover the complex interconnections hidden in networks. In this paper a genetic based approach to discover communities in networks is proposed. The algorithm optimizes a simple but efficacious fitness function able to identify densely connected groups of nodes with sparse connections between groups. The method is efficient because the variation operators are modified to take into consideration only the actual correlations among the nodes, thus sensibly reducing the search space of possible solutions. Experiments on synthetic and real life networks show the ability of the method to successfully detect the network structure.     

DRYING OF SOLIDS: THE INFINITE SLAB CONDITION

ABSTRACT

Fourier's second law was solved using convective boundary conditions without considering the shrinkage of the solid. The solutions for a finite and an infinite slab were compared to determine the dimensions for a slab to be considered as infinite. The solutions obtained for Bi = 0.1 and Bi = 100 correspond to heat and mass transfer-controlled processes, respectively, during drying. The results show that the finite slab cannot be considered as infinite, even for R²/R¹ > 20. The relative error obtained when the finite slab was assumed to be infinite was not significant for small Fourier numbers, but it increased as the Fourier number increased; errors were also higher for higher Biot numbers. When the numerical solution of a drying model was obtained for finite and infinite slabs, significant differences in drying kinetics and temperature evolution were observed.     

An investigation of the effectiveness of gender mainstreaming as a means of integrating the needs of women and men into spatial planning in the United Kingdom

This paper discusses the incidence of gender mainstreaming, and the extent to which it is proving an effective means of facilitating the incorporation of the needs of women, and men, in the operation of the spatial planning system in the United Kingdom. The paper is illustrated by a study undertaken for the Royal Town Planning Institute (RTPI) on the scope and nature of gender mainstreaming within local spatial planning departments. It also draws on a review of national planning guidance documents and other research in which the author is involved, on gender, ethnicity, diversity and disability.Key concepts are defined and misgivings discussed. The emphasis upon women's needs within the concept of gender, and the need to prioritise gender within the equalities and diversity agendas, are explained. The gendered nature of the built environment is outlined. The problem has long been identified by adherents of the women and planning movement. But policy change has proved elusive. Gender mainstreaming has been welcomed as a means of achieving change. But the process has proved conceptually problematic, of questionable efficacy and difficult to implement.The research incorporated an investigation of the extent to which gender is being mainstreamed into planning policy and practice. The effects of European Union directives and United Kingdom government equality initiatives upon national, regional and local planning level mainstreaming activities were investigated. A range of local planning authorities was chosen to provide case studies that showed the different approaches adopted. A qualitative approach was used to tease out those factors that inhibit or enable the mainstreaming process. Although equalities mainstreaming programmes are widespread within local authorities, the majority are generic rather than specifically gendered in emphasis. They are primarily concerned with personnel and procedural matters rather than spatial policy issues. The majority of planning authorities manifest limited understanding of either gender considerations or the process of mainstreaming. Nevertheless, a significant minority of authorities was found where progress is underway. However, progress is hampered by lack of central government policy direction and statutory support.A ‘Gender Mainstreaming Toolkit’ was developed to facilitate the process. It is concluded that this is likely to prove ineffective unless fundamental changes take place within the planning system. In order to achieve effective gender mainstreaming, the following prerequisites are identified: conceptual clarity, stronger policy guidance and legal support at central government level, educational change, and organisational and procedural changes within local planning authorities.     

Kinetic Release of Theophylline from Hydrophilic Swellable Matrices

The objective of this research was to evaluate the effect of hydroxypropylmethylcellulose (HPMC; Methocel K4M Premium) level and type of excipient on theophylline release and to attempt to predict the drug release from hydrophilic swellable matrices. Formulations containing theophylline anhydrous (10% w/w), Methocel K4M Premium (10%, 30%, and 40% w/w), different diluents (Lactose Fast Flo, Avicel PH-101, and Emcompress), and magnesium stearate (0.75% w/w) were prepared by direct compression at a target weight of 450 mg ± 5% and target hardness of 7 kp to 10 kp. It was found that, as the percentage of polymer in all formulations increased from 10% to 30% or 40%, the drug release decreased. However, there was no significant difference in drug release between formulations containing 30% polymer and formulations containing 40% polymer. At low levels of polymer, the drug release is controlled by the type of diluent used. Avicel PH-101 formulation gave the highest release, while its corresponding Emcompress formulation gave the lowest release. Formulations containing 30% or 40% polymer gave the same release profiles irrespective of the type of diluent used. In all cases, replacement of a portion of Methocel K4M Premium with any diluent resulted in increase of theophylline release. In addition, this investigation demonstrated that the drug release from hydrophilic swellable matrices can be predicted using only a minimum number of experiments.     

Cytocompatible polyurethanes from fatty acids through covalent immobilization of collagen

Two different polyurethanes synthesized from two triols derived from undecenoic acid (PU1) and oleic acid (PU2) fatty acids were functionalised with Collagen type I via plasma treatment aimed at obtaining novel biomaterials with improved biological properties. Scanning Electron Microscopy, X-ray photoelectron spectroscopy, optical microscopy, colorimetric titration methods and contact angle measurements confirmed the surface changes at each stage of treatment, both in terms of morphology and chemical composition. The results for osteoblastic cells (MG63) cultured in vitro proved that PUs modified with collagen had better cytocompatibility that the control PUs. In particular, PU2 displays higher cytocompatibility.