Effect of adsorbed metal ions and buffer nature on IgG separation from human plasma by column chromatography using an ion exchange resin,Amberlite IRC‐718

Fractionation of human plasma on ion exchanger resin was performed on Amberlite IRC‐718 saturated with metal ions. Depletion of human immunoglobulin G was carried out by column chromatography using Tris‐HCl, pH 7 at different concentrations. Results showed that, when Cu⁺² and Ni⁺² were adsorbed on the resin, one or two fractions of purified IgG were obtained, respectively. Whereas Fe⁺² and Zn⁺², both retain IgG and serum albumin or serum albumin alone. Furthermore, the Ni⁺²‐resin retention of serum proteins is too strong that the use of 700 mMTris‐HCl cannot liberate any other proteins than nonadsorbed serum albumin. In conclusion, this investigation demonstrates that immobilized metal ion affinity chromatography with Cu²⁺, Ni²⁺, and Fe²⁺ immobilized on Amberlite IRC‐718 has the potential to be developed as part of a process to purify IgG out of untreated human plasma as acceptable adsorption and elution levels of IgG could be achieved. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and characterization of open‐cell foams for sound absorption with rotational molding method

Foams with open‐cell structures have improved sound absorption abilities over conventional closed‐cell foams. One technique to optimize the acoustic abilities of open‐cell foams is to control their cellular properties through the manipulation of processing parameters. This article presents a novel process to synthesize open‐cell polymeric foams for acoustic applications. The process combined rotational foam molding and particulate leaching to produce foams with open‐cell networks that are desirable for acoustic absorption. Open‐cell foams with open‐porosity of about 0.90 were successfully fabricated with this combined foaming process. Effects of processing parameters on the cellular and acoustic properties of the foam samples were examined and discussed. On the basis of the results from the study, the cellular and acoustic properties of the foam fabricated from the proposed method can be controlled through the use of different salt particle sizes in the process. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

Distribution of the solvent-extractable organic compounds in fine (PM1) and coarse (PM1-10) particles in urban, industrial and forest atmospheres of Northern Algeria

The distribution of the solvent-extractable organic components in the fine (PM₁) and coarse (PM_1-10) fractions of airborne particulate was studied for the first time in Algeria. That was done during October 2006 concurrently in a big industrial district, a busy urban area, and a forest national park located in Algiers, Boumerdes, Blida, respectively, which are the three biggest provinces of Northern Algeria. Most of the organic matter identified in both particle size ranges consisted of n-alkanes and n-alkanoic acids, with minor contributions coming from polycyclic aromatic hydrocarbons (PAHs), nitrated polycyclic aromatic hydrocarbons (NPAHs), oxygenated PAHs, and other polar compounds (e.g., caffeine and nicotine). The potential emission sources of airborne contaminants were reconciled by combining the values of n-alkane carbon preference index (CPI) and selected diagnostic ratios of PAHs, calculated in both size ranges. The mean cumulative concentrations of PAHs reached 3.032 ng m^− 3 at the Boumerdes site, urban, 80% of which (i.e. 2.246 ng m^− 3) in the PM₁ fraction, 6.462 ng m^− 3 at Rouiba-Réghaia, industrial district, (5.135 ng m^− 3 or 80% in PM₁), and 0.512 ng m^− 3 at Chréa, forested mountains (0.370 ng m^− 3 or 72% in PM₁). Similar patterns were shown by all organic groups, which resulted overall enriched in the fine particles at the three sites. Carcinogenic and mutagenic potencies associated to PAHs were evaluated by multiplying the concentrations of “toxic” compounds times the corresponding potency factors normalized vs. benzo(a)pyrene (BaP), and were found to be both acceptable.     

FPGA-Based Efficient Design Approaches for Large Size Two’s Complement Squarers

This paper presents two optimized design approaches of two’s complement large size squarers using embedded multipliers in FPGAs. The realization of one of the approaches is based on Baugh–Wooley’s algorithm and the other one is a new sign-extension technique. To achieve efficient implementation, a set of optimized schemes for the realization of multi-level additions of the partial products is proposed. The squarers are implemented for operands of sizes ranging from 20 to 128 bits targeting Xilinx’ Spartan-3 using the ISE 8.1 synthesis and implementation tool, and from 38 to 128 bits targeting Altera’s Stratix II using the Quartus II 6.0 synthesis and implementation tool. The comparisons indicate that our proposed approaches offer substantial area savings and delay reduction. Using the Baugh–Wooley-based approach, the average saving in LUTs is close to 50% with an average delay reduction in the range of 13% to 20%. With the new sign extension approach, the area saving ranges from 54% to 70%, while the delay is reduced by approximately 25%. Embedded block usage for both approaches with different tools is reduced by 38% compared with the standard schemes.     

Thermal buckling analysis of laminated composite beams using hyperbolic refined shear deformation theory

In this article, thermal buckling of laminated composite beams, based on hyperbolic refined shear deformation theory, presented for the first time, is formulated using the principle of minimum total potential energy. Navier’s analytical solution is derived to analytically solve the differential equations and the thermal critical buckling is presented in closed-form solution. The effects of temperature distribution, length to thickness ratio, modulus ratio, and thermal expansion coefficient ratio on thermal buckling of isotropic, orthotropic and laminated composite beams are investigated. The accuracy of the numerical model is verified by comparison with the available results in the literature.     

A mix method of knowledge capitalization in maintenance

This paper deals with knowledge capitalization in maintenance especially in diagnosis and repair of industrial equipments. The goal is to propose a method of knowledge capitalization in order to develop a decision support system for maintenance operators. The knowledge capitalization cycle was adopted as the underlying principle. It consists of four principal steps: detect, preserve, capitalize and actualize the strategic knowledge. Different knowledge management tools and methods that can be used in the cycle are reviewed. We propose a mix method of knowledge capitalization in maintenance. This method integrates a representation and a reasoning model both completing each other and suitable to represent and manipulate the domain knowledge. The knowledge representation model using unified modelling language (UML) diagram proposes different domain models based on maintenance analysis to guide the domain expertise. The reasoning model uses the case-based reasoning which allows the manipulation of represented domain knowledge. Finally, the method is implemented on the pallet transfer system Sormel in the context of Proteus e-maintenance platform.     

Intrusion detection and tolerance: A global scheme

Protecting implemented security mechanisms and trusting their output (e.g. log files) when the host, under which they are deployed, is compromised, is among the major challenges that have to be faced. To fulfil this need, recent advances in security have considered the design of storage-based intrusion detection system, which detect intrusions by looking at the low-level disk requests patterns. However, these systems neither tolerate intrusions, nor do they distinguish whether the disk requests are generated by legitimate or malicious processes; and consequently, they generate a lot of false negative and positive alerts. In this paper, we present a Cooperative Intrusion Detection and Tolerance System, called CIDTS, which takes advantage of the information that are available at the network, host operating system, and storage level to better detect intrusion attempts in their early stages, even when the host is compromised. To allow cooperation, the disk communication interface that transports requests between the storage level and the host level is extended to forward information about the processes that generate the request. The paper also provides intrusion tolerance capabilities and provides techniques to support investigation activities. Copyright © 2007 John Wiley & Sons, Ltd.     

WHOMoVeS: An optimized broadband sensor network for military vehicle tracking

With the advance of sensing technologies and their applications, advanced sensor networks are gaining increasing interest. For certain sensitive applications, heterogeneous sensors can be deployed in the monitored space to ensure scalability, high-speed communication, and long network lifetime. Hybrid sensor networks have capabilities to combine the use of both resource-rich and resource-impoverished sensor nodes. This paper proposes a heterogeneous broadband sensor network architecture for military vehicle tracking. Powerful sensor devices with good bandwidth and energy capabilities are used as a communication backbone while energy sensors are used to track moving targets. Copyright © 2007 John Wiley & Sons, Ltd.     

Poly(4-vinylpyridine isopentyl bromide) as inhibitor for corrosion of pure iron in molar sulphuric acid

The effect of poly(4-vinylpyridine isopentyl bromide) (P4VPIPBr) in three degrees of quaternisation (6, 18 and 79%) on the corrosion of pure iron in molar sulphuric acid is investigated by potentiodynamic, polarisation resistance and weight loss measurements. The inhibition efficiency (E%) of P4VPIPBr increases with its concentration to attain 100% around 5×10⁻⁶ M. E% values obtained from the various methods are in good agreement. Polarisation measurements show also that the compound acts as a cathodic inhibitor and adsorbs on the pure iron surface according to the Frumkin adsorption isotherm model.