RIP – A robust IP access architecture

This research is of the view that only tightly coordinated work among security components as we know them today including firewalls, traffic analysis modules, intrusion detection systems, antivirus remediation systems, etc., is likely to take us closer to a more effective solution against some security threats. A structured Robust IP (RIP) access architecture is described and its components are analyzed through the use of a proof of concept testbed. Examples of the use of RIP and the heuristics it implements are evaluated. We also compare RIP performance to existing work. We show that there are currently some tradeoffs that need to be made between accuracy and responsiveness. We believe that this collaborative communication style between the components represents a significant step in the direction of self-defending networks and innovation in the area.     

An orchestration approach for unwanted Internet traffic identification

A simple examination of Internet traffic shows a wide mix of relevant and unwanted traffic. The latter is becoming increasingly harmful to network performance and service availability, while often consuming precious network and processing resources. Coordinated attacks, such as distributed denial-of-services (DDoS), large-scale scans, and worm outbreaks, occur in multiple networks simultaneously and become extremely difficult to detect using an individual detection engine. This paper presents the specification of a new orchestration-based approach to detect, and, as far as possible, to limit the actions of these coordinated attacks. Core to the proposal is a framework that coordinates the receiving of a multitude of alerts and events from detectors, evaluates this input to detect or prove the existence of anomalies, and consequently chooses the best action course. This framework is named Orchestration-oriented Anomaly Detection System (OADS). We also describe an OADS prototype implementation of the proposed infrastructure and analyze initial results obtained through experimentation with this prototype.     

Polysaccharide-based nanoparticles formation by polyeletrolyte complexation of carboxymethylated cashew gum and chitosan

Polyelectrolyte complex nanoparticles of chitosan and carboxymethyl cashew gum (CMCG) were prepared with CMCG with two different degrees of substitution (DS = 0.16 and 0.36). The effects of polymer concentration, molar mixing ratio (n ⁺/n ⁻) and mixing order of reactants on particle size distribution and zeta potential were investigated. Nanoparticle structure was elucidated by Fourier transform spectroscopy. Particle size of CH/CMCG DS = 0.16 dispersions was smaller than with DS 0.36 for all n ⁺/n ⁻ ratio investigated. Particle size smaller than 200 nm was obtained when CMCG with DS = 0.16 was used for particle formation. The polydispersity index values were small when CMCG DS 0.36 was used. Increasing the concentration of CMCG led to larger particle size. Zeta potential values for almost all molar mixing ratios were found to be positive (10–32 mV).     

Direct Observation of Austenite Reversion During Aging of 18Ni (350 Grade) Maraging Steel Through In-Situ Synchrotron X-Ray Diffraction

Metallurgical and Materials Transactions A - Austenite reversion in Fe–Ni alloys plays a significant role in determining their mechanical properties. Increasing the austenite content in these...     

Oxidized Cashew Gum Scaffolds for Tissue Engineering

In the last few years, several strategies have been proposed to fabricate scaffolds for tissue engineering (TE) applications; however, they are based on harsh and time‐consuming techniques. The choice for natural polymers such as cashew gum (CG) allows to circumvent the demands of biocompatibility and degradability of TE systems. In this work, CG, a polysaccharide derived from Anacardium occidentale trees, is functionalized with aldehyde groups through periodate oxidation. The resultant oxidized cashew gum (CGO) is mixed with gelatin (GE) to yield a covalently crosslinked hydrogel. CGO/GE sponges are obtained by employing a freeze‐drying methodology to the previously obtained hydrogels. The mechanical properties, swelling ability, and porosity of the GE/CGO sponges are tuned by using CGO with different degrees of oxidation. The resultant sponges can maintain high levels of water absorption and recover their initial mechanical properties after cyclic compression. Moreover, these porous and mechanically robust devices can support the adhesion and proliferation of cells, which can envision their application for the regeneration of soft tissues.     

Propranolol in mitral stenosis during sinus rhythm

Patients with early symptomatic mitral stenosis usually suffer from pulmonary congestion on the basis of left atrial and pulmonary venous hypertension. They are often in sinus rhythm, and cardiac output is usually well maintained. Symptoms occur most often when heart rate, cardiac output, or both are increased. In this study, intravenous propranolol administered to patients with pure mitral stenosis in sinus rhythm resulted in significant reductions in mitral diastolic gradient (-7.1 mm. Hg +/- 1.6 SED), mean pulmonary wedge pressure (--6.9 mm. Hg +/- 1.2) and mean pulmonary artery pressures (--9.0 mm. Hg +/- 1.2). This was due to simultaneous reduction of heart rate (--13.0 beats/minute +/- 2.6 and cardiac output (--0.5 L./minute +/- 0.2). A small associated reduction of left ventricular systolic pressure (--5.1 mm. Hg +/- 2.6) was not accompanied by adverse clinical effects. A potential role for propranolol in medical management of pure mitral stenosis in the presence of sinus rhythm is suggested.     

Morphological studies of the modified materials: Low-density polyethylene/poly(acrylic acid)/europium(III) and low-density polyethylene/poly(acrylic acid)/uranyl ion

The morphology of low-density polyethylene (LDPE) modified by in situ sorption and thermal polymerization of acrylic acid (AA) in the matrix was examined. The microstructure of the LDPE/poly(acrylic acid) (PAA) materials after Eu³⁺ and UO ion exchange was investigated. The phase behavior of these materials was analyzed using X-ray diffraction, scanning electron microscopy (SEM), and thermal measurements (DSC). The X-ray dif-fraction studies showed that PAA is located at amorphous region of the matrix. The LDPE/PAA surface, as investigate by SEM, was apparently homogeneous before and after Eu³⁺ and UO ion exchange, respectively. Two T_g values were found for the LDPE/PAA material before and after Eu³⁺ ion exchange. Also, three and four T_g values were found for LDPE/PAA after UO ion exchange depending on the amount of UO in the modified matrix. This indicates microphase domains in the LPDE/PAA-, LPDE/PAA/Eu³⁺-, and LPDE/PAA/UO -modified materials, although a lack of visible phase separation in the micrographs was observed. © 1996 John Wiley & Sons, Inc.     

On the use of a self organising map as feature compressor in the building of calibration models: Application to FTIR-spectrophotometry

Considerable attention has been given to strategies for variable selection in spectroscopic analysis. Here we introduce a different approach, the self organising map as a feature compressor, which also helps reducing the dimensionality of the problem. The method is straightforward and does not need previous knowledge about the regions of the spectra that contain relevant variables or information, so it applies generally. We coupled the method to multiple linear regression, partial component analysis and partial least squares and used it to quantitatively analyse 2-component liquid samples using FTIR spectroscopy. The predicted concentrations of the species within the mixture were extremely accurate (the correlation coefficients of estimated versus real concentrations were 0.997 and 0.995 for methanol and p-xylene, respectively). Furthermore, when applying the feature compression step, calibration models become more stable since they are able to better estimate a concentration not present in the training set.     

Deposition of selenium thin layers on gold surfaces from sulphuric acid media: Studies using electrochemical quartz crystal microbalance, cyclic voltammetry and AFM

In this paper we report here new considerations about the relationship between the mass and charge variations (m/z relationship) in underpotential deposition (UPD), bulk deposition and also in the H₂Se formation reaction. Nanogravimetric experiments were able to show the adsorption of H₂SeO₃ on the AuO surface prior to the voltammetric sweep and that, after the AuO reduction, 0.40 monolayer of H₂SeO₃ remains adsorbed on the newly reduced Au surface, which was enough to gives rise to the UPD layer. The UPD results indicate that the maximum coverage with Se_ads on polycrystalline gold surface corresponds to approximately 0.40 monolayer, in good agreement with charge density results. The cyclic voltammetry experiments demonstrated that the amount of bulk Se obtained during the potential scan to approximately 2 Se monolayers, which was further confirmed by electrochemical quartz crystal microbalance (EQCM) measurements that pointed out a mass variation corresponding of 3 monolayers of Se. In addition, the Se thin films were obtained by chronoamperometric experiments, where the Au electrode was polarized at +0.10 V during different times in 1.0 M H₂SO₄ + 1.0 mM SeO₂. The topologic aspects of the electrodeposits were observed in Atomic Force Microscope (AFM) measurements. Finally, in highly negative potential polarizations, the H₂Se formation was analyzed by voltammetric and nanogravimetric measurements. These finding brings a new light on the selenium electrodeposition and point up to a proposed electrochemical model for molecule controlled surface engineering.