A low-noise front-end for multiplexed ENG recording using CMOS technology

Multi-electrode cuffs have been proposed as a means for the parallel recording of naturally-occurring neural signals. Compared to a conventional tripole cuff providing a single channel signal, additional information about the velocity and direction of nerve signals can be extracted from the multi-electrode recordings. Moreover, interference suppression is improved and overall power consumption reduced, as the analysis shows. In this paper a new recording system is proposed, each channel of which consists of a low-noise preamplifier employing lateral bipolar transistors to provide an impedance match to the tissue and a path to ground for the switching currents of a single high-gain amplifier, which is multiplexed between the channels. The proposed system provides low-noise, low-power operation and practically identical channel gains and is suitable for integration in a larger CMOS-based system.     

5G Based on Cognitive Radio

Both the cognitive radio (CR) and the fifth generation of cellular wireless standards (5G) are considered to be the future technologies: on one hand, CR offers the possibility to significantly increase the spectrum efficiency, by smart secondary users (CR users) using the free licensed users spectrum holes; on the other hand, the 5G implies the whole wireless world interconnection (WISDOM—Wireless Innovative System for Dynamic Operating Megacommunications concept), together with very high data rates Quality of Service (QoS) service applications. In this paper, they are combined together into a “CR based 5G”. With this aim, two novel ideas are advanced: the 5G terminal is a CR terminal and the CR technology is chosen for WISDOM concept. Thus, the 5G takes CR flexibility and adaptability and makes the first step through a commercial and tangible form.     

Integrity and cell-monolayer permeability of chitosan nanoparticles in simulated gastrointestinal fluids

The objective of this study was to assess the integrity and intestinal permeability of chitosan nanoparticles (CNPs) in simulated gastrointestinal fluids (SGIF). The cell-associated and transported chitosan was quantified and visualized after incubation of the CNPs with Caco-2 cell monolayer with/without SGIF treatment. In order to establish the role of proteins in the SGIF, CNPs were incubated with 4 proteins having different isoelectric points (pI). CNPs incubated with the fluids did not attach to the cell monolayer in contrast to the intact CNPs. Negatively-charged protein formed the complex with CNPs leading to particle size increase, but protected CNPs from disintegration. In contrary, positively-charged protein interacted with cross-linker causing disintegration of CNPs. CNPs incubated with the fluids did not attach to the cell monolayer in contrast to the intact CNPs. The results suggested that the surface charges of CNPs and proteins play a critical role in structural changes of CNPs in biological environment.     

A Distributed Energy-Aware Routing Protocol for Underwater Wireless Sensor Networks

The design of routing protocols for Underwater Wireless Sensor Networks (UWSNs) poses many challenges due to the intrinsic properties of underwater environments. In this paper we present DUCS (Distributed Underwater Clustering Scheme), a new GPS-free routing protocol that does not use flooding techniques, minimizes the proactive routing message exchange and uses data aggregation to eliminate redundant information. Besides, DUCS assumes random node mobility and compensates the high propagation delays of the underwater medium using a continually adjusted timing advance combined with guard time values to minimize data loss. The theoretical and simulation studies carried out demonstrate its effectiveness.     

The Dependence of Energy Dissipation on the Elastic Energy Density of Friction Pairs in Hard Coating Films

The influence of different pairs on the energy dissipation of a given hard coating during fretting has been discussed. Based on the view of the competition between the elastic and plastic deformations in a fretting experiment, it suggests that the energy dissipation rate is proportional to the elastic energy density of pairs. This trend is in agreement with the reported experimental data. For comparison, hardness of pairs is used as the index to relate the antiwear properties of a DLC film against different pairs. It is obvious that the elastic energy density of pairs is more appropriate to predict the antiwear properties of the DLC film against different pairs.     

The Growth of Thin Lubricating Films of Plant Oils

The extreme conditions of high pressure and shear imposed in a lubricated sliding contact could influence tribochemical reactions that could occur over long sliding distances and time scales, possibly leading to changes in both friction and film thickness. Experiments conducted with 12 plant oils reveal for the first time, that thin lubricating films of some plant oils can grow to thicknesses much greater than what is predicted from either elastohydrodyamic theory or their adsorbed molecular heights. Some films grew as much as 25 times in thickness (unrefined canola oil), while others remained roughly unchanged (flaxseed and olive oil), or grew slightly and then collapsed during the test (safflower oil). The absence of a loss in film thickness and the viscoelastic-like behavior of the film when speeds are reduced to zero, support the view that polymerization could be the main mechanism of film growth. However, the lack of correlation between the degree of unsaturation and the film growth rate suggests that other mechanisms could also be at work.