SFG and DFG investigation of Au(111), Au(210), polycrystalline Au,Au–Cu and Au–Ag–Cu electrodes in contact with aqueous solutions containing KCN and 4-cyanopyridine

We report on potential-dependent in situ SFG and DFG spectroscopy carried out at Au(111), Au(210), polycrystalline Au, Au–Cu and Au–Ag–Cu electrodes in contact with aqueous solutions containing CN⁻ and 4-cyanopyridine (4CP). Spectroelectrochemical work was complemented by cyclic voltammetry. The chief stress has been placed on systematising and quantifying the interaction between 4CP and CN⁻ and the attending effects on the vibrational and electronic structures of the interface. The voltammetric behaviour of the investigated electrodes, modified by the addition of 4CP to the CN⁻ electrolyte, denote changes in the CN⁻ adsorption characteristics and effects of the adsorbed CN⁻ layer on the electrodic reactivity of 4CP. The differences among the investigated electrodes can be explained in terms of their respective degrees of atomic packing or with alloying effects on the stability of adsorbed CN⁻. The potential-dependent spectra have been analysed quantitatively with a model for the second order non linear susceptibility accounting for vibrational and electronic effects. The spectral changes induced by addition of 4CP denote interaction of the aromatic with the electrode through the CN⁻ monolayer. The non-resonant contribution yields information on the effects of 4CP on the fine structure of the bound electron density of states.     

Determination of the vapor pressures of select polychlorinated dibenzo-p-dioxins and dibenzofurans at 75-275 °C

Vapor pressures were determined for several polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) at 75-275 °C, extending the available literature data to more relevant temperature regions and providing the first experimental data for 2,3,7-trichlorodibenzo-p-dioxin (2,3,7-TriCD). A modification of the effusion technique, based upon controlling the diffusion of the target compound and subsequent high resolution gas chromatography/low resolution mass spectrometry (HRGC/LRMS) analysis, was proven comparable to other accepted methods for determining the vapor pressures of semi-volatile organic compounds (SVOCs). Vapor pressures for octachlorodibenzo-p-dioxin (OCDD) and octachlorodibenzofuran (OCDF) were in excellent agreement with those reported in literature. The application of the current method for the vapor pressure determinations of eight polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/PCDFs) in the extended temperature range (up to 275 °C) is reported. The extension of the vapor pressures to such temperatures, unprecedented for the PCDDs/Fs, is important for vapor-particle partitioning modeling in regions relevant to PCDD/F formation and control. Estimates for the melting temperatures and enthalpies of sublimation and vaporization are also reported, the latter for which no experimentally determined values have been found in the literature. The use of the method to deliver reproducible, trace concentrations (ppt-ppb) of targets was applied to the calibration of the jet-REMPI/TOFMS as an online detector for low chlorinated PCDDs/Fs.     

Application of the cross entropy method to the GLVQ algorithm

This paper discusses an alternative approach to parameter optimization of well-known prototype-based learning algorithms (minimizing an objective function via gradient search). The proposed approach considers a stochastic optimization called the cross entropy method (CE method). The CE method is used to tackle efficiently the initialization sensitiveness problem associated with the original generalized learning vector quantization (GLVQ) algorithm and its variants. Results presented in this paper indicate that the CE method can be successfully applied to this kind of problem on real-world data sets. As far as known by the authors, it is the first use of the CE method in prototype-based learning.     

Eliminating Selective Dropping Attack in Mobile Ad Hoc Network

Wireless Personal Communications - In this paper, we propose a new reputation approach, called I-WD (improved WatchDog). We attempt to eliminate selective dropping attack that ensue when malicious...     

Multi-contact vertical ladder climbing with an HRP-2 humanoid

We describe the research and the integration methods we developed to make the HRP-2 humanoid robot climb vertical industrial-norm ladders. We use our multi-contact planner and multi-objective closed-loop control formulated as a QP (quadratic program). First, a set of contacts to climb the ladder is planned off-line (automatically or by the user). These contacts are provided as an input for a finite state machine. The latter builds supplementary tasks that account for geometric uncertainties and specific grasps procedures to be added to the QP controller. The latter provides instant desired states in terms of joint accelerations and contact forces to be tracked by the embedded low-level motor controllers. Our trials revealed that hardware changes are necessary, and parts of software must be made more robust. Yet, we confirmed that HRP-2 has the kinematic and power capabilities to climb real industrial ladders, such as those found in nuclear power plants and large scale manufacturing factories (e.g. aircraft, shipyard) and construction sites.     

In Vitro Determination of the Antifungal Activity of Artemisia campestris Essential Oil from Algeria

The chemical composition of the essential oil isolated from the aerial parts of Artemisia campestris from Algeria and its antifungal activity against 10 filamentous fungal strains were investigated. The A. campestris essential oil was obtained in a yield of 0.71% (v/w). The major constituents of the oil were α-pinene (18.65%), β-pinene (16.78%), β-myrcene (17.34%), and germacrene D (10.34%). Our study showed that A. campestris essential oil was a potent antifungal agent against some pathogenic fungal species. Fusarium graminearum was the most sensitive strain to A. campestris essential oil with minimal inhibitory concentration and minimal fungicidal concentration values of 1.25 µL/mL (v/v). The essential oil also exhibited a strong fungicidal activity against the tested fungi, except for Penicillium citrinum, P. viridicatum, and Aspergillus niger (MFC >20 µL/mL). Our findings suggested the application of A. campestris essential oil as a biofungicide in order to reduce the dependence on synthetic fungicides and ensure food safety and quality.     

Effect of thermal insulation using leather and carpentry wastes on thermal comfort and energy consumption in a residential building

In this work, we investigate the effect of the thermal insulation by leather wastes (wet-blue chrome shavings and buffing dust) and carpentry wastes (wood shavings and sawdust) on the energy consumption of a model building using the average climatic data of the city of Casablanca (Morocco). For this study, we used the dynamic thermal simulation tool “TRNSYS 16” which predicts the thermal behavior of building and systems associated with it. Using this software, we evaluated the effect of the above material wastes on thermal comfort and building energy consumption. The type and the thickness of the materials were considered as variants to choose the better solution. The average temperatures of building supposed thermally insulated compared to those obtained without insulation clearly show the thermal insulation ability of tested materials during the cold and warm periods of the year. Increasing the thickness of the insulator makes locals increasingly comfortable. Because of their performance, leather and carpentry wastes can compete with conventional insulating materials such as polystyrene and cork.     

Application of dimensional analysis and regression tools to estimate swell pressure of expansive soil in Tebessa (Algeria)

Bulletin of Engineering Geology and the Environment - In the Tebessa area, the nature of geological formations in the subsurface is influenced considerably the superstructures built on them by the...     

Inactivation of E. coli and Pseudomonas aeruginosa by electrochloration under bipolar pulsed polarization

This work is devoted to the biocides effects by electrochlorination under a pulsated bipolar polarization (PBP) of low potentials (− 1 V/cm to + 1.6 V/cm). Two working electrodes were used, one in platinum and the other in AISI 430 stainless steel, in two different electrolytes: sterilized distilled water and 0,9N sterilized NaCl solution, contaminated by E. Coli or by Pseudomonas Aeruginosa. The inactivation of these bacteria was established under the action of three biocide treatments: E.F (Electric Field); the combination of E.F and Active Chlorine (A.C) and the combination of E.F, A.C and Ions in Solutions (I.S). The synergistic effect of these treatments leads to a high efficiency in disinfection. The results showed that the total inactivation of the E. Coli stain is reached in half a minute, while that of P. aeruginosa is reached in 20 min. The use of an economic stainless steel electrode allowed us to observe that, for pulsate frequencies higher than 10³ s^− 1, the formation of active chlorine increased whereas the corrosion speed decreased.     

Mechanistic relationships among PCDDs/Fs, PCNs, PAHs, CIPhs, and CIBzs in municipal waste incineration

An extensive investigation was conducted to understand polychlorinated dibenzo-p-dioxin and furan (PCDD/F) formation mechanisms and their relationship with other organic compounds. PCDD/F, chlorophenols (CIPhs), chlorobenzenes (CIBzs), polyaromatic hydrocarbons (PAHs), and polychlorinated naphthalenes (PCNs) were analyzed in the boiler exit gases of a field-scale municipal solid waste incinerator under various operating conditions. The TEQ value and the concentration of target compounds changed with incinerator operating conditions. Low mass PAHs and 246-triCIPh increased dramatically during shut downs; the latter was associated with increased 1368- and 1379-TeCDD. A strong correlation was observed between PCNs and PCDFs and adjacent PCNs homologue group were closely related to each other. This suggested that PCN formation is related with chlorination/dechlorination mechanisms similar to PCDFs. PCDDs were related with most of the CIPhs and the high chlorinated benzenes. Most of target compounds except PAHs had a positive correlation (R2 > 0.5) with TEQ and half of them showed a good relationship (R2 > 0.8) with PCDDs/Fs toxic equivalency (TEQ).