The present paper presents a physical prototype that simulates the response of a single degree of freedom dynamic system, equipped with a novel semi-active vibration control device. This device comprises two superelastic NiTi elements working in phase opposition and aims to prevent deck unseating in simply supported bridges, during a seismic excitation. The special design of this device allows to avoid problems related to stress–relaxation phenomena and material degradation because of cyclic loading that have been observed in similar passive dissipation devices. The proposed design uses a strategy that permits the continuous adapting of the accumulated stress in the NiTi wires, on the basis of the response of the device to external excitations. Although unloaded, the NiTi elements remain strain/stress free, preventing stress–relaxation phenomena. With the occurrence of a dynamic excitation, a cumulative strain/stress process in the superelastic wires is initiated, enabling higher martensite transformation ratios and therefore increasing the damping capacities of the system while keeping the stresses in the wires inside a narrower superelastic window. The strain/stress accumulation in the superelastic wires is a direct result of the motion of the structure itself, with no need for external energy input.

The use of agar-based biomaterials for the development of emerging areas, such as tissue engineering or ‘smart materials’ production has recently gained great interest. Understanding how these gel-forming polysaccharides self-organise in aqueous media and how these associations can be tuned to meet the specific needs of each application is thus of great relevance. As an extension of previous pioneering research concerning the application of the microwave-assisted extraction (MAE) technique in the recovery of native (NA) and alkali-modified (AA) agars, this article focuses on the different molecular assemblies assumed by these novel NA and AA when using different MAE routes. The molecular architectures in dilute (5, 10, 50 and 100 mg mL
1) and concentrated (1.5% (w/w)) aqueous media were imaged by AFM and cryoSEM, respectively. Relevant structural and physicochemical properties were investigated to support the microscopic data. Different extraction routes led to polysaccharides with unique properties, which in turn resulted in different molecular assemblies. Even at 5 mg mL
1, AFM images included individual fibers, cyclic segments, aggregates and local networks. At higher polymer concentrations, the structures further aggregated forming multilayer polymeric networks for AA. The more compact and denser 3D networks of AA, imaged by cryoSEM, and their higher resistance to large deformations matched the 2D-shapes observed by AFM. Depending on the nature of the AA chains, homogeneous or heterogeneous growth of assemblies was seen during network formation. The obtained results support well the view of double helix formation followed by intensive double helix association proposed for agar gelation.

n/a

Non-catalytic cellulosomal carbohydrate-binding modules (CBMs) are responsible for increasing the catalytic efficiency of cellulosic enzymes by selectively putting the substrate (a wide range of poly- and oligosaccharides) and enzyme into close contact. In the present work we carried out an atomistic rationalization of the molecular determinants of ligand specificity of a family 11 CBM from thermophilic C. thermocellum (CtCBM11), based on a NMR and molecular modeling approach. We have determined the NMR solution structure of CtCBM11 at 25 and 50 ºC and derived information on the residues of the protein involved in ligand recognition and on the influence of the length of the saccharide chain on binding. We obtained models of the CtCBM11/cellohexaose and CtCBM11/cellotetraose complexes by docking in accordance with the NMR experimental data. Specific ligand/protein CH-π and Van der Waals interactions were found to be determinant for the stability of the complexes and for defining specificity. Using the order parameters derived from backbone dynamics analysis in the presence and absence of ligand and at 25 and 50 ºC, we determined that the protein’s backbone conformational entropy is slightly positive. This data in combination with the negative binding entropy calculated from ITC studies supports a selection mechanism where a rigid protein selects a defined oligosaccharide conformation.

A novel porous polymer-ionic liquid composite with poly(2-hydroxyethyl methacrylate) (PHEMA) and 1-butyl-3-methylimidazolium hexafluorophosphate (BMIPF6) has been synthesized by γ-irradiation without heat or chemical initiators. The products can be reversibly converted into organogels. The composites are potential candidates for electrochemical applications. The use of γ-radiation can be a simple and versatile alternative way to obtain these materials.

A rapidly changing market leads to software systems with highly volatile requirements. In many cases, new demands in software can often be met by extending the functionality of systems already in operation. By modularizing volatile requirements that can be altered at the client’s initiative or according to market demands, we can build a stepping-stone for management of requirements change. The volatility must be managed in a way that reduces the time and costs associated with updating a system to meet the new requirements. In this chapter, we present an approach for handling volatile concerns during early life cycle software modeling. The key insight is that techniques for aspect-oriented software development can be applied to modularize volatility and to weave volatile concerns into the base software artifacts.

Purpose - The main objective of this paper is to identify and rank a set of performance measures using the Interpretive Structural Modeling (ISM) approach to support the automotive supply chain performance evaluation.
Design/methodology/approach - The paper develops a framework to analyze the interactions among a suggested set of performance measures using the {ISM} approach. To identify the contextual relationships among the suggested measures, five experts from the automotive industry were consulted.
Findings - Using the {ISM} approach the performance measures were clustered attending to their driving and dependence power. Inventory level and lead time are the two performance measures at the bottom level of the hierarchy, implying higher driving power. Also, operational costs, business wastage, environmental costs, delivery time and customer satisfaction are identified as autonomous measures. This means that they are relatively disconnected from the other suggested performance measures. It is also observed that the cash-to-cash cycle is a weak driver but strongly dependent on the other performance measures.
Practical implications - The proposed approach gives managers a better understanding on mutual influences of performance measures (driving performance measures) and also those measures which are most influenced by others (dependent performance measures). Using {ISM} managers can get insight on the order and direction of complex relations among the suggested performance measures. This kind of information is strategic for managers could identify which performance measures they should concentrate on, and how they can manage the tradeoffs between them.
Originality/value - This paper highlights the deployment of {ISM} as a manager' decision support tool in the identification and ranking of a set of performance measures to make part of a supply chain performance measurement system.

The advancement of CMOS technology led to the integration of more complex functions. In the particular of wireless transceivers, integrated LC tanks are becoming popular both for VCOs and integrated filters [1]. For RF applications the main challenge is still the design of integrated inductors with the maximum quality factor. For that purpose, tapered, i.e., variable width inductors have been proposed in the literature. In this paper, analytical expressions for the determination the pi-model parameters, for the characterization of variable width integrated inductors are proposed. The expressions rely exclusively on geometrical and technological parameters, thus granting the rapid adaptation of the model to different technologies. The results obtained with the model are compared against simulation with ASITIC, showing errors below 10%. The model is then integrated into an optimization procedure where inductors with a quality factor improvement in the order of 20-30% are obtained, when compared with fixed width inductors.

The notion of service-enhanced product brings new perspectives for value creation and differentiation in manufacturing. The existence of complex and highly customized products, the inclusion of business services that add value to the product typically require the collaboration of multiple stakeholders. It is natural that each stakeholder has its own set of values and preferences and as a result, conflicts among them might emerge due to some values misalignment. Therefore, the Value System Alignment assessment should be included when selecting partner for the formation of long-term collaborative networks for the operation and management of the product life-cycle. This paper presents the implementation of a Value System alignment assessment model, as a component of the cloud-based collaborative environment designed to support a mix of collaborative enterprise networks involved in the solar energy sector.

Progressive scaling of CMOS technology towards nanoscale regime enables the design of highly integrated systems for the wireless communications market. As technology continues to scale, the variability in process parameters may cause significant deviations in device behaviour. The complexity of designing spiral inductors has lead to the development of multi-objective optimization based design methodologies yielding the generation of Pareto-optimal surfaces. However, the variability of the process parameters is usually ignored, yielding the selection of ideally optimal solutions in detriment of quasi-optimal solutions that may prove to be better, should the robustness against process parameter variation be accounted for. We propose the generation of an extended Pareto front containing both optima and quasi-optima solutions. Finally information on the robustness to process parameter variations, is used for electing the best design solutions.The evaluation of the extended set of sub-optima solutions requires methods capable to find the set of local optima, since solutions that are close to each other in the performance index space may be very distant in the design parameter space.

Transport properties of natural (noncompressed) cork were evaluated for water and ethanol in both vapor and liquid phases. The permeability for these permeants has been measured, as well as the sorption and diffusion coefficients. This paper focuses on the differences between the transport of gases' relevant vapors and their liquids (water and ethanol) through cork. A transport mechanism of vapors and liquids is proposed. Experimental evidence shows that both vapors and liquids permeate not only through the small channels across the cells (plasmodesmata), as in the permeation of gases, but also through the walls of cork cells by sorption and diffusion as in dense membranes. The present study also shows that cork permeability for gases was irreversibly and drastically decreased after cork samples were exposed to ethanol or water in liquid phase.