Defining and computing a value based cyber-security measure

In earlier work, we presented a value based measure of cybersecurity that quantifies the security of a system in concrete terms, specifically, in terms of how much each system stakeholder stands to lose (in dollars per hour of operation) as a result of security threats and system vulnerabilities; our metric varies according to the stakes that each stakeholder has in meeting each security requirement. In this paper, we discuss the specification and design of a system that collects, updates, and maintains all the information that pertains to estimating our cybersecurity measure, and offers stakeholders quantitative means to make security-related decisions.     

Synthesis and physical properties of new oxide AgMnO<Subscript>2</Subscript>

A novel oxide AgMnO₂ was prepared from LiMnO₂ via Ag⁺ → Li⁺ exchange in the eutectic melt AgNO₃-KNO₃. It crystallizes in a monoclinically distorted unit cell (SG C2/m) caused by the Jahn-Teller (J-T) ion Mn³⁺ (3d ⁴). The structure was refined by isotypy with the crednerite CuMnO₂. There are two long axial Mn–O of 264.2(0) pm and four equatorial bonds of 192.7(3) pm and Mn–O–Mn adjoining (83.07°) are bent below the ideal angle. The thermal variation of the magnetic susceptibility (χ/T ⁻¹) obeys a Curie-Weiss law with manganese in a trivalent, high spin (HS) state accommodated in elongated MnO₆ octahedra (14.8%). Direct coupling between Mn³⁺ involves negative exchange interactions through long-range antiparallel moments with a temperature θ _p = −436 K and a magnetic moment of 5.26 μ_B/Mn³⁺ slightly larger than the spin only moment. The title oxide is stable in air up to ∼680 °C before it decomposes into metal silver. It displays a semi-conducting behavior with an activation energy of ∼0.45 eV, characteristic of a conduction by low mobility polarons between Ag^+/2+ where nearly all polarons are bonded. The photoelectrochemical properties of AgMnO₂ have been investigated by photocurrent technique in 1 M KOH. The cathodic photocurrent J _ph provides unambiguous evidence of p-type character attributed to oxygen insertion (0.025 oxygen by formula unit) as required by the charge compensating mechanism. The valence band is made up of Ag−4d wave functions positioned at ∼5.14 eV below vacuum. A comparison with CuMnO₂ was also reported.     

Groundwater interaction in the coastal environment: hydrochemical,electrical and seismic approaches

The heterogeneous Plio-Quaternary coastal aquifer of the Mamora Basin is the most significant reservoir of Morocco. It is composed of sandstones, conglomerates, limestones and more or less argillaceous sands. The increase in the requirements for water in this area requires further information on the relations between the geometry of the aquifer and the salinity of the water. A hydrochemical analysis was undertaken and highlighted three zones of high mineralization. A geophysical approach allowed the determination of the principal aquifer levels, the localization of the various types of water (fresh, brackish and salt) and the geometry of the aquifer base. The results obtained by these two approaches provide a better image of the phenomena governing the groundwater flows and their interactions      

Thermal behavior and energy saving analysis of a flat with different energy efficiency measures in six climates

This article aims at studying the impact of many construction parameters of a flat on its energy performance and thermal comfort. The studied parameters are: the envelope thermal insulation, the orientation, the floor level, the ground coupling, the roof and the external walls absorption coefficient and the controlled mechanical ventilation. The TRNSYS based numerical study is performed in six different climates ranging from cold to desert one. The numerical model has been validated against experimental results obtained from summer and winter long term monitoring campaigns of the flat located in the Marrakech city, Morocco. The apartment’s heating and cooling loads as well as thermal discomfort indexes are calculated for the possible eleven configurations combining the studied parameters. The results show that high thermal insulation of the walls leads to an apparent summer overheating with an increase in the flat’s total thermal load by up to 18% in all the considered climates, except for the cold one. It was found that the walls’ light thermal insulation resulting from the cavity wall technique is sufficient to reach an acceptable level of thermal comfort thus preventing summer overheating. Similarly, thermal insulation of the slab-on-grade floor was found to perform an increase in thermal load for hot and moderate climates by at least 67%. The best combination of all the studied energy efficiency measures for each climate conditions was evaluated via comparison to a reference case that represents the actual apartment.     

A striking observation on the fluorescence of a twisted intramolecular charge transfer (TICT) molecule used to probe polymer dynamics in the bulk state

An anomalous effect on the twisted intramolecular charge transfer (TICT) phenomenon of 4-(N,N-dimethylamino) benzonitrile (DMABN) dissolved in elastomers such as poly(propylene oxide), poly(ethylene oxide) has been observed. Under irradiation, the normal fluorescence of DMABN in these matrices has been found to increase strongly while the emission arising from the TICT state decreases slightly.     

Kinetic of CO2 absorption and carbamate formation in aqueous solutions of diethanolamine

The absorption rates of CO₂ into aqueous solutions of Diethanolamine (DEA) with varying concentrations from 0.2 to 4M and temperature range from 293 to 323 K were measured by using a laboratory stirred reactor. The CO₂ partial pressure was varied in a range that the reaction would occur in pseudo first order regime. Experimental data were analyzed and the kinetic parameters associated with the reaction were determined. The activation energy for the deprotonation of the intermediate zwitterion was estimated at about 11.4 kcal/mol. The contribution of carbamate formation to the overall absorbed CO₂ was experimentally evaluated and found to be of the order of 100%.