Neuro-fuzzy TSK network for calibration of semiconductor sensor array for gas measurements

The neuro-fuzzy network applying Takagi-Sugeno-Kang (TSK) fuzzy reasoning for the calibration of the semiconductor sensor array is developed in this paper. The structure, as well as the learning algorithm of the neuro-fuzzy network, is presented and tested on the example of estimation of the concentration of gas components in the gaseous mixture (so-called artificial nose problem). The results of numerical experiments are presented and discussed.     

Effects of solvents on characteristics of crystalline lactose extracted in ternary and quaternary systems

In a technique referred to as lactose extractive crystallisation, a volatile solvent was added to a solution of lactose dissolved in water. As this second solvent was miscible in water, its presence in the saturated or supersaturated lactose solution would reduce the lactose solubility and hence lactose crystals were formed and grew in the ternary system lactose–ethanol–water. It was found that selecting ethanol as a second solvent could produce needle-shaped crystals having the lowest median size of 8 μm, and β-lactose content up to 60% at 60 °C. On the other hand, using two miscible solvents, one non-volatile and one volatile, such as by adding ethanol to the ternary system, lactose–water–glycerol, crystals having large needle-like or trapezoidal shape and β-lactose content up to 90% could be made at 70 °C. The triangle diagram comparing the solubility of lactose in the glycerol and ethanol aqueous solutions at equilibrium and at different temperatures is presented for the first time. Based on this diagram, it is suggested that the weight ratios of two solvents used and reaction temperatures could be manipulated to produce lactose crystals with different characteristic properties.     

Crystal Structures of a Bioactive 6′‐Hydroxy Variant of Sisomicin Bound to the Bacterial and Protozoal Ribosomal Decoding Sites

Parasitic infections recognized as neglected tropical diseases are a source of concern for several regions of the world. Aminoglycosides are potent antimicrobial agents that have been extensively studied by biochemical and structural studies in prokaryotes. However, the molecular mechanism of their potential antiprotozoal activity is less well understood. In the present study, we have examined the in vitro inhibitory activities of some aminoglycosides with a 6′‐hydroxy group on ring I and highlight that one of them, 6′‐hydroxysisomicin, exhibits promising activity against a broad range of protozoan parasites. Furthermore, we have conducted X‐ray analyses of 6′‐hydroxysisomicin bound to the target ribosomal RNA A‐sites in order to understand the mechanisms of both its antibacterial and antiprotozoal activities at the molecular level. The unsaturated ring I of 6′‐hydroxysisomicin can directly stack on G1491, which is highly conserved in bacterial and protozoal species, through π–π interaction and fits closer to the guanidine base than the typically saturated and hydroxylated ring I of other structurally related aminoglycosides. Consequently, the compound adopts a lower energy conformation within the bacterial and protozoal A‐sites and makes pseudo pairs to either A or G at position 1408. The A‐site‐selective binding mode strongly suggests that 6′‐hydroxysisomicin is a potential lead for the design of next‐generation aminoglycosides targeting a wide variety of infectious diseases.     

Fabrication and in vitro evaluations with osteoblast-like MG-63 cells of porous hyaluronic acid-gelatin blend scaffold for bone tissue engineering applications

In this study, hyaluronic acid–gelatin (HyA–Gel) scaffolds were prepared with HyA:Gel ratios of 15:85, 50:50, and 85:15 with the goal of obtaining a porous biocompatible scaffold for bone tissue engineering applications. Scanning electron microscopy and Fourier-transform infrared spectroscopy were done to characterize the morphological orientations of the scaffolds. The biocomposite structure was highly porous and the pores in the scaffolds were interconnected. The compressive strength of the scaffold was 7.39 ± 0.2 MPa for the HyA–Gel when fabricated at a ratio of 15:85. To assess the biocompatibility and cell behavior on the HyA–Gel biocomposite, the proliferation of MG-63 osteoblast cell on the scaffolds was examined using the MTT assay, optical microscopy, and confocal microscopy. Collagen type I and osteopontin expression of cells cultured on the scaffolds were examined using immunoblotting. The scaffolds fabricated with a 15:85—HyA:Gel ratio showed excellent biocompatibility, good mechanical properties, and high porosity, which suggest that the highly porous scaffold holds great promise for use in bone tissue engineering applications.     

Aqueous Extended-Surfactant Based Method for Vegetable Oil Extraction: Proof of Concept

The use of hexane to extract vegetable oil from oilseeds is of growing concern due to hexane’s environmental impact and because of worker exposure concerns. The goal of our work is to demonstrate that the aqueous extended-surfactant-based method is a viable alternative for vegetable oil extraction. In our method, ground oilseeds were dispersed in the aqueous surfactant solution, allowing the oil to be liberated from the seeds as a separate phase from the aqueous phase. The impact of pH, shaking intensity, shaking time and seed to liquid ratio on oil yield are presented. Extended-surfactants are a new type of surfactant with propoxylate (PO) and/or ethoxylate (EO) groups inserted between the hydrophilic head and the hydrophobic alkyl chain of the surfactant molecule. This unique structure of extended-surfactants enables them to produce ultralow interfacial tension with vegetable oils. We have found that at low aqueous concentrations (less than 0.3 wt%), extended-surfactant solutions are able to produce ultralow interfacial tension between aqueous extraction and vegetable oil phases. At optimum condition (seed to liquid ratio of 1–5, 30 min extraction at 150 shakes/min and 30 min centrifugation at 2,170×g) we achieved 93–95% extraction efficiency for peanut and canola oils at 25 °C. The oil quality produced from the aqueous extended-surfactant-based method was found to be comparable or even superior to that obtained from hexane-based extraction, further demonstrating the viability of aqueous extended-surfactant based extraction.     

Neuro-fuzzy network for flavor recognition and classification

This paper presents the neuro-fuzzy Takagi-Sugeno-Kang (TSK) network for the recognition and classification of flavor. The important role in this process fulfills the self-organizing process used for the creation of the inference rules. The self-organizing neurons perform the role of clustering data into fuzzy groups with different membership values (the preprocessing stage). Applying the automatic control of clusters, we have the optimal size of the TSK network. The developed measuring system has been applied for the recognition of flavor of different brands of beer. The fuzzy neural network is used for processing signals obtained from the semiconductor sensor array. The results of numerical experiments have confirmed the excellent performance of such solutions.     

How to create flow experience in exergames? Perspective of flow theory

Exergames are popular computer applications. However, exergaming literature has insufficiently explained the formulation of user-experienced flow and what user needs may facilitate such a formulation, indicating a gap. To fill the gap, this study adopts the flow theory to construct a framework and examines how enjoyment and challenge impact the creation of flow, and how users’ need for achievement and need for exercise may facilitate it. We recruited 583 participants who were asked to play exergames and complete a survey. The analytical results indicate that exercise enjoyment is positively linked to flow, while the need for exercise strengthens such a link. Moreover, challenge is positively linked to flow, and the need for achievement strengthens that link. This study is the first using the flow theory to explain the process by which exergamers experience flow.     

A Survey of QoS-aware Routing Protocols for the MANET-WSN Convergence Scenarios in IoT Networks

Wireless Personal Communications - Wireless Sensor Network (WSN) and Mobile Ad hoc Network (MANET) have attracted a special attention because they can serve as communication means in many areas...     

A case for centrally controlled wireless sensor networks

In this article we present the Intelligent, Manageable, Power-Efficient and Reliable Internetworking Architecture (IMPERIA), a centrally managed architecture for large-scale wireless sensor networks (WSNs). We discuss the advantages of a centralized management over distributed approaches and derive our design by rigorously minimizing the amount of state information on individual sensor nodes and all sources of message collision during network operations. The result is a clustered multi-hop TDMA protocol that globally synchronizes the network and collects data at ultra-low power consumption.We present the end-to-end architecture and detail the algorithms we developed for (a) efficient network topology discovery and link quality estimation, (b) combined routing and clustering for pre-defined basestations, and (c) the scheduling of the medium access for multi-cluster and multi-channel data collection.IMPERIA has been implemented on TinyOS and IBM’s Mote Runner and successfully deployed in applications for vibration sensing as well as datacenter energy management. This article summarizes the performance results from simulations, laboratory experiments, and deployment measurements that support our design decisions.     

Strength-based topology optimisation of plastic isotropic von Mises materials

Conventionally, topology optimisation is formulated as a non-linear optimisation problem, where the material is distributed in a manner which maximises the stiffness of the structure. Due to the nature of non-linear, non-convex optimisation problems, a multitude of local optima will exist and the solution will depend on the starting point. Moreover, while stress is an essential consideration in topology optimisation, accounting for the stress locally requires a large number of constraints to be considered in the optimisation problem; therefore, global methods are often deployed to alleviate this with less control of the stress field as a consequence. In the present work, a strength-based formulation with stress-based elements is introduced for plastic isotropic von Mises materials. The formulation results in a convex optimisation problem which ensures that any local optimum is the global optimum, and the problems can be solved efficiently using interior point methods. Four plane stress elements are introduced and several examples illustrate the strength of the convex stress-based formulation including mesh independence, rapid convergence and near-linear time complexity.