Toxicological Patterns of Multicomponent Polymer Systems

Development of new polymer systems (PS) based on thermo-active resins is important not only from a chemical viewpoint but also because of the opportunity for programmable changing their properties and subsequent application in clinical practice. Some chemical features of a new composition for a multicomponent polymer system (MPS) based on hydrophilized unsaturated polyester resin (HUPR) are presented. Strength parameters of several resins of different compositions are examined. The analysis of the acute oral toxicity of these resins in white Wistar rats proves that they are low toxic. These PS do not demonstrate any harmful effects on human skin after the predicting irritation and sensitization tests using epicutaneous samples. Their main advantages include preliminary water-solubility and capacity to incorporate water, good dilution into water and resin water dispersions, porosity, low relative mass, high strength indices, improved ecological features, thin-founding capacity, good relief impressions in combination with high adhesion ability towards wet surfaces. A wide MPS usage in the manufacture of orthopedic plaster dressings, prostheses, splints, insoles, positive-sample dental imprints, and casts is recommended

Business Value Is not only Dollars - Results from Case Study Research on Agile Software Projects

Business value is a key concept in agile software development. This paper presents results of a case study on how business value and its creation is perceived in the context of agile projects. Our overall conclusion is that the project participants almost never use an explicit and structured approach to guide the value creation throughout the project. Still, the application of agile methods in the studied cases leads to satisfied clients. An interesting result of the study represents the fact that the agile process of many projects differs significantly from what is described in the agile practitioners’ books as best practices. The key implication for research and practice is that we have an incentive to pursue the study of value creation in agile projects and to complement it by providing guidelines for better client’s involvement, as well as by developing structured methods that will enhance the value-creation in a project

Experiences in using practitioner's checklists to evaluate the industrial relevance of requirements engineering experiments

Background: A grand challenge for Requirement Engineering (RE) research is to help practitioners understand which RE methods work in what contexts and why. RE researchers recognize that for an RE method to be adopted in industry, RE practitioners should be able to evaluate the relevance of empirical studies to their practice. One possible approach to relevance evaluation is the set of perspective-based checklists proposed by Kitchenham et al. Specifically, the checklist from the practitioner's perspective seems to be a good candidate for evaluating the relevance of RE studies to RE practice. However, little is known about the applicability of this checklist to the RE field. Moreover, this checklist also requires a deeper analysis of its reliability. Aim: We propose a perspective-based checklist to the RE community that allows evaluating the relevance of experimental studies in RE from the practitioner's/consultant's viewpoint. Method: We followed an iterative design-science based approach in which we first analyzed the problems with a previously published checklist and then developed an operationalized proposal for a new checklist to counter these problems. We performed a reliability evaluation of this new checklist by having two practitioners apply the checklist on 24 papers that report experimental results on software requirements specifications' comprehensibility. Results: We report first-hand experiences of practitioners in evaluating the relevance of primary studies in RE, by using a perspective-based checklist. With respect to the reliability of the adjusted checklist, 9 of out 19 questions show an acceptable proportion of agreement (between two practitioners). Conclusions: Based on our experience, the contextualization and operationalization of a perspective-based checklist helps to make it more useful for the practitioners. However, to increase the reliability of the checklist, more reviewers and more discussion cycles are necessary

Agile Requirements Prioritization: What Happens in Practice and What Is Described in Literature

[Context & motivation] Requirements (re)prioritization is an essential mechanism of agile development approaches to maximize the value for the clients and to accommodate changing requirements. Yet, in the agile Requirements Engineering (RE) literature, very little is known about how agile (re)prioritization happens in practice. [Question/problem] To gain better understanding of prioritization practices, we analyzed the real-life processes as well as the guidance that the literature provides. We compare the results of a literature research with the results of a multiple case study that we used to create a conceptual model of the prioritization process. We set out to answer the research question: “Which concepts of agile prioritization are shared in practice and in literature and how they are used to provide guidance for prioritization.” [Results] The case study yielded a conceptual model of the inter-iteration prioritization process. Further, we achieved a mapping between the concepts from the model and the existing prioritization techniques, described by several authors. [Contribution] The model contributes to the body of knowledge in agile RE. It makes explicit the concepts that practitioners tacitly use in the agile prioritization process. We use this for structuring the mapping study with the literature and plan to use it for analyzing, supporting, and improving the process in agile projects. The mapping gives us a clear understanding of the 'deviation' between the existing methods as prescribed in literature and the processes we observe in real life. It helps to identify which of the concepts are used explicitly by other authors/ methods