Machine learning techniques to predict sensitive patterns to fault attack in the Java Card application

Fault attack represents one of the serious threats against Java Card security. It consists of physical perturbation of chip components to introduce faults in the code execution. A fault may be induced using a laser beam to impact opcodes and operands of instructions. This could lead to a mutation of the application code in such a way that it becomes hostile. Any successful attack may reveal a secret information stored in the card or grant an undesired authorisation. We propose a methodology to recognise, during the development step, the sensitive patterns to the fault attack in the Java Card applications. It is based on the concepts from text categorisation and machine learning. In fact, in this method, we represented the patterns using opcodes n-grams as features, and we evaluated different machine learning classifiers. The results show that the classifiers performed poorly when classifying dangerous sensitive patterns, due to the imbalance of our data-set. The number of dangerous sensitive patterns is much lower than the number of not dangerous patterns. We used resampling techniques to balance the class distribution in our data-set. The experimental results indicated that the resampling techniques improved the accuracy of the classifiers. In addition, our proposed method reduces the execution time of sensitive patterns classification in comparison to the SmartCM tool. This tool is used in our study to evaluate the effect of faults on Java Card applications.     

Inhibition of asphaltene flocculation in light crude oil: effect of pressure,temperature and inhibitor concentration

Abstract

In this study, a light crude oil sample was taken from Hassi Messaoud field to characterize its physicochemical properties. The asphaltene flocculation onset was determined in the dead oil by Flocculation Titrimeter equipment. The petroleum resins have been extracted from the same crude oil and tested as an inhibitor of asphaltene flocculation then their efficiency has been studied at different conditions of pressure and temperature. The results point out that the extracted resins may have two different effects on the onset point depending upon the operator conditions and the concentration of the added resins to crude oil.     

Diversité floristique des mares temporaires de la région d’Annaba (Nord-Est Algérien)

Nine wetlands in Annaba region (North East of Algeria) were the subject of floristic inventories during three years (2014–2016). We have revealed the presence of five types of temporary ponds in which Ranunculus aquatilis L is dominant. The studied flora is rich and diversified. It comprises 190 species and 143 genera belonging to 58 botanical families. These species were either strictly subservient to humid zones or transgressive from terrestrial environments. This flora is characterized by a big proportion of rare and / or threatened taxa (11.05%). The composition of global biological spectra shows the dominance of therophytes, with 99 taxa (52.11%). The majority of the listed species belong to the Mediterranean phytochronic species. Eighteen taxa belonged to the endemic category. The preservation of this exceptional biodiversity, threatened in the short term, urgently requires phytoecological studies and relevant protection measures.     

Diversity‐Oriented Synthesis of Diol‐Based Peptidomimetics as Potential HIV Protease Inhibitors and Antitumor Agents

Peptidomimetic HIV protease inhibitors are an important class of drugs used in the treatment of AIDS. The synthesis of a new type of diol‐based peptidomimetics is described. Our route is flexible, uses d ‐glucal as an inexpensive starting material, and makes minimal use of protection/deprotection cycles. Binding affinities from molecular docking simulations suggest that these compounds are potential inhibitors of HIV protease. Moreover, the antiproliferative activities of compounds 33 a , 35 a , and 35 b on HT‐29, M21, and MCF7 cancer cell lines are in the low micromolar range. The results provide a platform that could facilitate the development of medically relevant asymmetrical diol‐based peptidomimetics.     

Chemical composition and insecticidal properties of Origanum glandulosum (Desf.) essential oil from Algeria

BACKGROUND: To find natural compounds with insecticidal properties which could be an alternative to synthetic insecticides, oregano essential oil was tested against the insect Rhizopertha dominica devastating stored cereals. RESULTS: Oregano oils were isolated by steam distillation, analysed by gas chromatography and gas chromatography–mass spectrometry and investigated for their insecticidal activities against Rhizopertha dominica. Contact and fumigant toxicities of global oil and three of its fractions recovered respectively after 2 h and after 0–2.5, 2.5–5 and 5–10 min of extraction were tested using the filter paper method. Eighteen components, representing 92.6% of the oil, were identified. The major components were thymol (38.8%), carvacrol (32.9%), p‐cymene (7.9%) and γ‐terpinene (5.1%). Toxicity tests showed that insect mortality increases with the concentration used (0.39%, 0.78%, 1.56%, 3.12% and 6.24%V). For all concentrations, the contact effect of global oil and fraction F₂ was better than the fumigant effect. Whereas fractions F₁ and F₃ were more toxic by fumigation for concentrations lower or equal to 1.56%, their contact effect was more significant for concentrations higher than 1.56%. CONCLUSION: These results suggest that oregano oil has important insecticidal properties and may be useful as a natural grain protectant against Rhizopertha dominica to replace synthetic insecticides. Copyright © 2008 Society of Chemical Industry     

Sulfate removal from aqueous solutions by hydrous iron oxide in the presence of heavy metals and competitive anions : Macroscopic and spectroscopic analyses

Sulfate removal from aqueous solutions by hydrous iron oxide freshly prepared in the presence of some heavy metals cations and some anions has been investigated in batch systems by varying the pH and concentrations of various ions. Infrared spectroscopic analyses have been performed to characterize the effect of these ions on the mechanism of sulfate interaction with the surface of the hydrous oxide.The results of macroscopic studies show that in the binary systems, copper and zinc ions inhibit the sulfate removal at pH higher than 5.5. In the presence of oxalate and phosphate ions, significant competitive effects are observed contrary to acetate ions.The IR spectra of the solids obtained show that among the studied ions, only phosphate ions have an effect on the sulfate interaction with the surface of the oxide. In their presence, the formation of outer sphere complex is more probable.     

Investigation of characteristic and performance of polyvinyl chloride ultrafiltration membranes modified with silica-oriented multi walled carbon nanotubes

The complicated and dynamic nature of membrane fouling is one of the most challenging issues that need to be addressed to obtain an efficient membrane. In this work, silica-oriented multiwalled carbon nanotubes (Si-MWCNTs) are synthesized by the sol–gel method and characterized using several analytical techniques. Novel polyvinyl chloride (PVC) ultrafiltration membranes are fabricated by incorporation of Si-MWCNT nanoparticles at varying loading levels (0–2 wt%) using the phase inversion method. Membrane morphology, chemical composition, thermal behavior, crystallinity, roughness, hydrophilicity, and mechanical strength are characterized and filtration performance is tested to compare the results with those of pristine PVC membranes. The results reveal that the addition of 0.5% Si-MWCNT nanoparticles into the casting solution exhibits the highest flux (400 L/m²h), sodium alginate (SA) rejection rate (96%), and flux recovery ratio (93%) due to having the highest hydrophilicity, an improved structure, and surface properties revealed by surface morphology and bulk property analysis. Furthermore, the results of dynamic mechanical and nanoindentation analyses confirm that mechanical properties such as hardness, Young's modulus, and stiffness of the pristine membrane are significantly improved by the addition of Si-MWCNT nanoparticles.     

Numerical Analysis of Turbulent Forced Convection of Nanofluid Flow over a Heated Shallow Cavity

This work presents a numerical investigation of turbulent forced convection of a nanofluid over a heated cavity in a horizontal duct. Heat transfers in separated flows are frequently encountered in engineering applications, such as: heat exchangers, axial and centrifugal compressor blades, gas turbines blades, and microelectronic circuit boards. Thus, it is very essential to understand the mechanisms of heat transfer in such regions in order to enhance heat transfer. Different volume fractions of nanoparticles are presented in the base fluid and different types of nanoparticles are used. The objective of this study is to check the effect of nanofluid on heat transfer in such a configuration. Numerical simulations are performed for pure water and four nanofluids (Cu, CuO, Ag, and Al₂O₃). The results are analyzed through the thermal and dynamical fields with a particular interest to the skin friction coefficient and Nusselt number evolutions. The average Nusselt number increases with the volume fraction of nanoparticles for the whole tested range of Reynolds number. A correlation of average Nusselt number versus Reynolds number and volume fraction of each type of nanoparticles over the cavity wall is proposed in this paper.