Preparation of functionalized lignin beads from oak wood alkaline lignin

Alkaline lignin extracted from oak wood cooperage wastes was chemically modified to prepare beads by suspension polymerization on water without the use of organic solvents. These beads were macroporous and swelled in hydrophilic solvents. They were functionalized under microwaves to be used as scavenging agents in winery applications. The beads prepared by this approach have the advantage of being more acceptable by winemakers than synthetic polymer supports previously reported. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013     

Evaluation of Shewhart time-between-events-and-amplitude control charts for correlated data

In recent years, several techniques based on control charts have been developed for the simultaneous monitoring of the time interval T and the amplitude X of events, known as time-between-events-and-amplitude (TBEA) charts. However, the vast majority of the existing works have some limitations. First, they usually focus on statistics based on the ratio $\frac{X}{T}$, and second, they only investigate a reduced number of potential distributions, that is, the exponential distribution for T and the normal distribution for X. Moreover, until now, very few research papers have considered the potential dependence between T and X. In this paper, we investigate three different statistics, denoted as Z₁ , Z₂ , and Z₃ , for monitoring TBEA data in the case of three potential distributions (gamma, normal, and Weibull), for both T and X, using copulas as a mechanism to model the dependence. An illustrative example considering times between machine breakdowns and associated maintenance illustrates the use of TBEA control charts.     

Dimensional soft tissue thermal injury analysis using transmission line matrix (TLM) method

The skin is sensitive to temperature change and the effect may not be significant while the temperature at the surface is below 44°C. However, higher surface temperatures (above 44°C) will further incur time burning and carbonization so that irreversible damage may happen. An investigation of the heating intensity and the duration of the exposure to the heating source suggested that when the surface temperature is greater than 51°C, the exposure time required to destroy the epidermis is so short that trans‐epidermal necrosis may occur. In this paper, we present one‐ and two‐dimensional numerical models based on transmission line matrix (TLM) method for a quantitative prediction of skin burn injury resulting from the exposure of the skin surface to a high temperature heat source. Transient temperatures are numerically estimated by solving the Pennes' bioheat equation, and the damage function denoting the extent of burn injury is calculated using the Arrhenius assumptions for protein damage rate. The TLM model is used to analyse the effects of exposure time and geometrical dimensions of mutlilayered skin, on the transient temperature distribution and damage extension. TLM results showed good agreement with other numerical sources, suggesting that TLM modelling can be used as a tool for an effective thermal diagnostic of burn injuries. Copyright © 2008 John Wiley & Sons, Ltd.     

A high performances CMOS CCII and high frequency applications

In this paper, we propose an improved translinear based CCII configuration. Heuristic algorithm is used for optimal sizing regarding static and dynamic performances. PSPICE simulations for AMS 0.35 μm CMOS technology show that the current and voltage bandwidths are respectively 2.6 GHz and 3.9 GHz, and the parasitic resistance at port X (R _X ) has a value of 18 Ω for a control current of 100 μA. The improved configuration is used as a building block into high frequency design applications: a current controlled oscillator and a tunable fully integrable band pass filter. The oscillator frequency can be tuned in the range of [290–475 MHz] by a simple variation of a DC current. The central frequency of the band pass filter can be varied in the range of [1.22–1.56 GHz] and the quality factor vary in the range [8–306] with a simple variation of a DC current.     

TLM simulation of microwave hybrid sintering of multiple samples in a multimode cavity

Microwave heating technology is a powerful mean to ensure successful sintering of ceramic materials. In sintering experiments, low loss insulators, conductors and high‐loss ceramics are microwaved so as to get optimal mechanical and structural properties. It is known that low‐loss ceramic materials such alumina and zirconia exhibit long waiting time before reaching a critical coupling temperature at which microwaves can be readily absorbed. On the other hand, some ceramics such as silicon carbid have a high loss factor and therefore can be used as a process stimulus for microwave sintering of microwave transparent ceramics. Furthermore, successful sintering experiments often require the use of carefully designed insulating structure in order to minimize thermal gradients caused by heat loss from surfaces. All these problems have led to the introduction of microwave hybrid heating (MHH) schemes using higher dielectric loss susceptors, insulation or coating. Since MHH depend mainly on human expertise, the optimization of sintering experiments will certainly benefit from numerical simulations. The transmission line matrix (TLM) is used to study two MHH schemes where both a susceptor and an insulating matrix were, respectively, used as process stimulus for microwave heating of multiple alumina samples within a three‐dimensional multimode cavity. The effects of such MHH schemes and target settings on electric field distribution and power absorption rates are reported in this paper. Copyright © 2003 John Wiley & Sons, Ltd.     

Retention of cadmium ions from aqueous solutions by poly(ammonium acrylate) enhanced ultrafiltration

Cadmium removal from aqueous solution by polyelectrolyte enhanced ultrafiltration (PEUF) with relatively low transmembrane pressure was investigated at varying conditions of polyelectrolyte and cadmium concentrations, transmembrane pressure, ionic strength and pH. The poly(ammonium acrylate), with two average molecular weights (8000 and 15 000 Da) were used as polyelectrolyte. Flux declines during ultrafiltration of polyelectrolyte solutions. An effort has been made to evaluate these resistances independently at different operating conditions. The hydraulic membrane resistance is higher for processing solutions of PAmA₈ than solutions of PAmA₁₅. The study of ionic strength effect demonstrates that it decreases the retention of cadmium ions and increases the permeate flux. More than 99% of cadmium was retained for a NaNO₃ feed concentration less than 5 × 10⁻² mol L⁻¹. The pH effect study on the cadmium recovery revealed a maximum retention around 98% for pH 4.     

The antioxidant status and oxidative stability of muscle from lambs receiving oral administration of Artemisia herba alba and Rosmarinus officinalis essential oils

The effect of the dietary supplementation to lambs of essential oils (EOs) from rosemary (Rosmarinus officinalis) and artemisia (Artemisia herba alba) on the antioxidant status of muscle and on meat oxidative stability was studied. Eighteen Barbarine lambs were divided into 3 groups and for 95 days received oat hay and concentrates. One group (C) was not supplemented, while the other two groups received 400 mg/kg of EOs from rosemary (R400) or artemisia (A400). Both EOs possessed antioxidant properties and their oral administration improved the reducing and radical scavenging capacity of the muscle compared to the C treatment (P < 0.01). Nevertheless, supplementing EOs did not exert protection against lipid oxidation and did not affect the colour stability in meat over 7 days of aerobic storage.     

An automated sensor nodes’ speed estimation for wireless sensor networks

Wireless sensor networks (WSNs) have become more and more notorious thanks to their numerous advantages. But, some of the WSN weaknesses, inherent to sensor nodes’ particularities (low memory, finite battery, etc.), make these networks vulnerable especially for some particular scenarios such as nodes’ mobility which alters the correct network functioning and completely compromises its normal behavior. Thus, we propose in this paper a novel mobility prediction model called the general Bayesian-based mobility prediction (G-BMP) model where sensor nodes’ speed values are derived based on a Bayesian inference paradigm and upon the occurrence of “expired links” and “non-expired links” events. Moreover, to make the implementation of G-BMP possible on sensor devices, we introduce some simplifications during the computation and the transmission of speed distributions. The evaluation of G-BMP using python illustrates the accuracy of the model in deriving the correct speed values in a timely manner. We also compare the performance of G-BMP to the native BMP model that only considers the expired link events when updating the nodes’ speed distributions. The results show that the convergence to real speed values within sensor nodes is faster with G-BMP than that with the native BMP model. In addition, all the simulations illustrate the accuracy of the simplifications used to reduce the overhead generated by the frequent exchange of speed distributions.     

Novel Enhanced LoRaWAN Framework for Smart Home Remote Control Security

Wireless Personal Communications - A smart home interconnects every object of our living space to the Internet. Based on various technologies and standards, many device suppliers propound an...