Reliability‐based estimation of the survival of Listeria monocytogenes in chorizos

Reliability analysis is especially important when critical decisions are to be made involving potentially severe adverse consequences such as foodborne illness. Owing to uncertainty associated with the parameters controlling survival of Listeria monocytogenes in chorizo (a Mexican‐style sausage), the time needed to reduce the count by a certain number (n) of logs (t_nD) is probabilistic. In this paper the first‐order second‐moment (FOSM) method based on Taylor series expansion is used to derive the expected value and standard deviation of t_nD as function of the operating conditions (random variables) affecting survival, namely initial water activity (a_w0) of the sausage batter, storage temperature (T) and airflow velocity (F), along with their uncertainties characterised by their means and coefficients of variation. For any given n the derived t_nD probability distribution enables one to determine an estimate of t_nD for any desired level of reliability or confidence level, such as 50% (median value), 95%, 99%, etc. Among the conclusions drawn were: (i) the variability associated with T and F has a minor effect on estimating uncertainty in t_nD, whereas the reliability of t_nD estimation is greatly influenced by the uncertainty in a_w0; and (ii) the uncertainty in a_w0 has the greatest impact when a_w0 of the sausage formulation exceeds 0.90. The approach used and discussed in this paper can be applied to any survival/inactivation study to incorporate the effect of uncertainty in the various extrinsic and intrinsic parameters on the survival kinetics of the pathogen in a food system under evaluation. Copyright © 2006 Society of Chemical Industry     

Thermal and thermoelastic properties of fast extrusion furnace (FEF) carbon black loaded SBR vulcanizates

The effect of FEF carbon black as filler on the thermal capacity c, diffusivity a, and thermal conductivity λ, of styrene butadiene rubber (SBR) composites in the temperature range 300–420 K was studied. The filler strongly increases the thermal diffusivity, whilst strongly decreasing the thermal capacity and the thermal conductivity (except at high FEF content ≥80 phr). The influence of the filler on the thermoelastic behaviour of the same composites was also investigated. It was found that the thermoelastic temperature change (ΔT) increased with carbon black concentration as well as the entropy change per unit extension.     

Cotton Seed Oil Oxidation Catalysed by Amino Acids and Albumin in Aqueous and Non-Aqueous Media

The oxidation of refined cotton seed oil catalysed by various α-amino acids and albumin have been studied in aqueous and non-aqueous media. Cysteine, phenylalanine and albumin possessed pro-oxidant effect in cotton seed oil in aqueous and non-aqueous media. Serine exhibited pro-oxidant activity in aqueous media and minor anti-oxidant effect in non-aqueous media. The effectiveness of the amino acids on cotton seed oil oxidation was in the following descending order in both aqueous and non-aqueous media: cysteine > phenylalanine > serine. The pro-oxidant effect in aqueous media might be due to the predominant presence of the protonated amino nitrogen. Whilst, amino acid-metal complex might be responsible for the pro-oxidant effect in non-aqueous media.     

Chemical factors affecting soiling and soil release from cotton-containing durable press fabric. VIII. Grafting of polyester/cotton blend fabrics with carboxyl-containing polymer

Fabric samples of polyester/cotton blend were graft copolymerized to different levels (add-ons) with poly(acrylic acid) and poly(methacrylic acid) using the mutual γ-irradiation technique and the Fe²⁺–H₂O₂ redox system, respectively. The copolymers so obtained were given durable press treatments with and without conventional nonionic softener using DMDEU as the crosslinking agent. The susceptibility of the copolymers before and after crosslinking to aqueous and nonaqueous oily soiling and their ability to release the soils were examined. It was found that hydrophilization of the surface of polyester/cotton blend through grafting with the said carboxyl-containing polymers brings about a significant improvement in the resistance of the blend to aqueous and nonaqueous oily soil particularly after crosslinking in presence of nonionic softener. A certain improvement in the ease of oily soil removal could be achieved by grafting. The opposite holds true for aqueous soil release. Soiling and soil release depends on the magnitude and method of grafting, medium of soiling, as well as the formulation of crosslinking treatments. The effect of grafting on some properties of the blend fabric before and after crosslinking was also examined.     

Progress and challenges in sustainability,compatibility, and production of eco-composites: A state-of-art review

Owing to economic and environmental benefits, new generations of materials/commodities follow “from waste to wealth” strategy. Recently, there has been a huge upsurge in research on the development of eco-composites using recycled plastic polymers and agro-residues because the eco-composites satisfy the stringent environment regulations and are cost-effective. Herein, we present a detailed review on the potential use of several types of natural fillers as an efficient reinforcement for recycled plastic polymers. In particular, the characterization of different categories of eco-composites according to their morphological, physical, thermal, and mechanical properties is extensively reviewed and their results are analyzed, compared, and highlighted. Furthermore, a framework to produce functional eco-composites, which includes functionalization of ingredients, critical issues on microstructural parameters, processing, and fabrication methods, is outlined and supported with sufficient data from the literature. Finally, the review outlines the emerging challenges and future prospects of eco-composites to be addressed by interested researchers to bridge the gap between research and commercialization of such a class of material. Overall, the acquired knowledge will guide researchers, scientists, and manufacturers to plan, select, and develop various forms of eco-composites with enhanced properties and optimized production processes.     

A dynamic video watermarking algorithm in fast motion areas in the wavelet domain

In this paper, we propose a video watermarking algorithm which embeds different parts of a single watermark into different shots of a video under the wavelet domain. Based on a Motion Activity Analysis, different regions of the original video are separated into perceptually distinct categories according to motion information and region complexity. Thus, the localizations of the watermark are adjusted adaptively in accordance with the human visual system and signal characteristics, which makes them perceptually invisible and less vulnerable to automated removal. In addition, contrary to traditional methods where the watermark remains at a fixed position on the screen, the watermark moves along with moving objects and thus motion artefacts can be avoid. The multi-frame based extraction strategy ensures that the watermark can be correctly recovered from a very short segment of video. Individual frames extracted from the video also contain watermark information. Experimental results show that the inserted watermark is not only less perceptible but also robust against common video processing attacks.     

Micro-engineered first wall tungsten armor for high average power laser fusion energy systems

The high average power laser program is developing an inertial fusion energy demonstration power reactor with a solid first wall chamber. The first wall (FW) will be subject to high energy density radiation and high doses of high energy helium implantation. Tungsten has been identified as the candidate material for a FW armor. The fundamental concern is long term thermo-mechanical survivability of the armor against the effects of high temperature pulsed operation and exfoliation due to the retention of implanted helium. Even if a solid tungsten armor coating would survive the high temperature cyclic operation with minimal failure, the high helium implantation and retention would result in unacceptable material loss rates. Micro-engineered materials, such as castellated structures, plasma sprayed nano-porous coatings and refractory foams are suggested as a first wall armor material to address these fundamental concerns. A micro-engineered FW armor would have to be designed with specific geometric features that tolerate high cyclic heating loads and recycle most of the implanted helium without any significant failure. Micro-engineered materials are briefly reviewed. In particular, plasma-sprayed nano-porous tungsten and tungsten foams are assessed for their potential to accommodate inertial fusion specific loads. Tests show that nano-porous plasma spray coatings can be manufactured with high permeability to helium gas, while retaining relatively high thermal conductivities. Tungsten foams where shown to be able to overcome thermo-mechanical loads by cell rotation and deformation. Helium implantation tests have shown, that pulsed implantation and heating releases significant levels of implanted helium. Helium implantation and release from tungsten was modeled using an expanded kinetic rate theory, to include the effects of pulsed implantations and thermal cycles. Although, significant challenges remain micro-engineered materials are shown to constitute potential candidate FW armor materials.     

Optimal placement of multiple STATCOM for voltage stability margin enhancement using particle swarm optimization

This paper proposes an approach for optimal placement of STATic synchronous COMpensator (STATCOM) in power systems. The approach is based on the simultaneous application of particle swarm optimization (PSO) and continuation power flow (CPF) to improve voltage profile, minimizing power system total losses, and for maximizing system loadability with respect to the size of STATCOM. Simulation results show the suitability of the PSO technique in finding multiple optimal solutions to the problem with reasonable computational effort. The installation of the STATOCM on these buses can increase the system voltage stability margin. The proposed technique is examined on the IEEE57 bus test system.