Concept of cleaner production in Vojvodina

The Autonomous Province of Vojvodina is an autonomous province in Serbia, containing about 27% of its total population according to the 2002 Census. It is located in the northern part of the country, in the Pannonia plain. The importance of sector of the environment protection becomes even larger and observable, especially with respect of the strategic determination of Government of the AP of Vojvodina, the Republic of Serbia on the association with the European economic area (EEA) and joining with the states – members of the European Union (EU). Restitution of the concept of the cleaner production (CP) significantly helps to companies and the responsible persons (especially in the domain of industry) to harmonize their business activities with law demands concerning the environment protection, as well as to improve their processes and the process sequences. This makes a starting base for the obtaining of the integrated license for the installations that are included in a list of installations that have to obtain an integrated licenses (some 250 installations), on the basis of the Law on the integrated prevention and control of pollution of Vojvodina, the Republic of Serbia, for which the dead point is the year 2015.     

Kinetic model of a Diels–Alder reaction in a molten state: thermal and viscoelastic behaviour

Polymer Bulletin - Information on the reaction kinetics in the melt is a valuable prerequisite for a successful application of self-healing ability to benzoxazine-based thermosetting resins. The...     

Post polymerisation hypercrosslinking of styrene/divinylbenzene poly(HIPE)s: Creating micropores within macroporous polymer

Porous copolymers of styrene and divinylbenzene (DVB) were prepared by emulsion templating using high internal phase emulsions (HIPEs) as precursors for monoliths. The ratio of monomers was varied in order to obtain samples with different degrees of crosslinking and different amounts of unreacted vinyl groups originating from DVB. PolyHIPE monoliths were subjected to reswelling and treatment with a radical initiator. Significant enlargement of the amount of meso- and micropores in the material was found resulting in a substantial increase of BET surface area, up to 7.2 times compared to untreated polyHIPEs. The treated PolyHIPE monoliths retained the open macroporous morphology typical of polyHIPE materials. Solid state ¹³C NMR experiments were used to determine the amount of unreacted vinyl groups in polyHIPE samples, both before and after the hypercrosslinking treatment.     

Sustainability performance evaluation in industry by composite sustainability index

The growing importance of sustainable development as a policy objective has initiated a debate about those suitable frameworks and tools useful for policy makers when making a sustainable decision. Composite indicators (CIs) aggregate multidimensional issues into one index, thus providing comprehensive information. However, it is frequently argued that CIs are too subjective, as their results undesirably depend on the normalization method, a specific weighting scheme, and the aggregation method of sub-indicators. This article applies different combinations of normalization, weighting, and aggregation methods for the assessment of an industrial case study, with the aim of determining the best scheme for constructing CIs. The applied methodology gradually aggregates sustainable development indicators into sustainability sub-indices and, finally, to a composite sustainability index. The normalization methods included in this analysis are: minimum–maximum, distance to a reference, and the percentages of annual differences over consecutive years. Equal weightings, the ‘benefit of the doubt’ approach, and budget allocation process were used for determining the weights of individual indicators and sustainability sub-indices. The linear, geometric, and non-compensatory multi-criteria approaches (NCMCs) were used as aggregation methods. The NCMC is modified to fit the two-level aggregation, then to sub-indices, and finally to a composite sustainable index. Also, a penalty criterion is introduced into the evaluation process with the aim of motivating the company to move towards sustainable development. The results are analyzed by variance-based sensitivity analysis. According to the results the recommended scheme for CIs’ construction is: distance to a reference–benefit of the doubt–linear aggregation.     

Formal apparatus for measurement of lightweight protocols

Lightweight protocols are an important topic in the area of computer communications. With the proliferation of security services not only ordinary communication protocols, but also cryptographic protocols, i.e. security services, have become a subject of research into possible appropriate lightweight solutions. At first glance it may seem surprising, but the evidence suggests that there is a permanent need for lightweight protocols. And this need is ever increasing, due to the gap between desktop (and other ordinary computing devices) and mobile wireless devices that have inherently limited resources. However, the notion of lightweight protocol has not been formally addressed in the literature, which is the purpose of this paper. A formal model that can be used to evaluate lightweight properties of protocols is presented and the appropriate metrics are introduced. Despite the fact that the model and the metrics target weak processing devices, they can be deployed for ordinary computing environments and may present a methodology for evaluation of lightweight cryptographic protocols in standardization processes.     

An approach for concurrent evaluation of technical and social aspects of software development methodologies

The paper presents an approach for evaluation of software development methodologies (SDM) that considers the aspects of a SDM’s social adoption and technical efficiency. It builds on existing evaluation models used in the field of SDM. Case study approach was used to validate the model in four software development organisations. In all four cases the management confirmed that the model provided valuable new insights into adoption and efficiency of the companies’ SDM.     

The structure and properties of acrylic‐polyurethane hybrid emulsions and comparison with physical blends

Aqueous acrylic‐polyurethane hybrid emulsions were prepared by semibatch emulsion polymerization of a mixture of acrylic monomers (butyl acrylate, methyl methacrylate, and acrylic acid) in the presence of polyurethane dispersion. Equivalent physical blends were prepared by mixing acrylic emulsion and polyurethane dispersion. The weight ratio between acrylic and polyurethane components varied to obtain different emulsion properties, microphase structure, and mechanical film properties of hybrid emulsions and physical blends. Particle size and molecular mass measurements, scanning electron microscopy, glass transition temperature, and rheological measurements performed characterization of the latex system. The mechanical properties were investigated by measuring tensile strength and Koenig hardness of dried films. The experimental results indicate better acrylic‐polyurethane compatibility in hybrid emulsions than in physical blends, resulting in improved chemical and mechanical properties. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 67–80, 2000     

On the Analysis of an EFG Method Under Large Deformations and Volumetric Locking

This work investigates a modified element-free Galerkin (MEFG) method when applied to large deformation processes. The proposed EFG method enables the direct imposition of the essential boundary conditions, as a result of the kronecker delta property of the special shape functions, constructed in the neighborhood of the essential boundary. The plasticity model assumes a multiplicative decomposition of the deformation gradient into an elastic and a plastic part and considers a J ₂ elasto-plastic constitutive relation that accounts for a nonlinear isotropic hardening. The constitutive model is written in terms of the rotated Kirchhoff stress and of the conjugate logarithmic strain measure. A total Lagrangian formulation is considered in order to improve the computational performance of the proposed algorithm. Here, aspects related to the volumetric locking are numerically investigated and an F-bar approach is considered. Some numerical results are presented, under axisymmetric and plane strain assumption, in order to attest the performance of the proposed method.     

Differential scanning calorimetric examination of melamine–formaldehyde microcapsules containing decane

The main objective of this study was to investigate the composition of microcapsules and the degree of curing of melamine–formaldehyde (MF) resin, which formed a shell of microcapsules, by the use of differential dynamic calorimetry (DSC). For this purpose, decane was chosen as core material. The microencapsulation of decane with MF resin was carried out at different temperatures and pH values. The temperature and pH value were kept constant during the process. The composition of the microcapsules and the degree of curing of the shell material were studied during and after the microencapsulation process. DSC analysis, in combination with scanning electron microscopy analysis, was revealed as an effective tool for the investigation of the microencapsulation process with MF resin. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011