Combining scanning probe microscopy and x-ray spectroscopy

A new versatile tool, combining Shear Force Microscopy and X-Ray Spectroscopy was designed and constructed to obtain simultaneously surface topography and chemical mapping. Using a sharp optical fiber as microscope probe, it is possible to collect locally the visible luminescence of the sample. Results of tests on ZnO and on ZnWO4 thin layers are in perfect agreement with that obtained with other conventional techniques. Twin images obtained by simultaneous acquisition in near field of surface topography and of local visible light emitted by the sample under X-Ray irradiation in synchrotron environment are shown. Replacing the optical fibre by an X-ray capillary, it is possible to collect local X-ray fluorescence of the sample. Preliminary results on Co-Ti sample analysis are presented.     

周期性输入组分和扫气在改善钯膜反应器甲烷部分氧化制氢中的作用(英文)

The partial oxidation of methane under periodic operation over Ni/γ-Al2O3 catalyst was investigated in a Pd-membrane reactor.The effects of key parameters such as the inlet composition and the sweeping gas on methane conversion and the hydrogen recovery are numerically established with two periodic input functions.In order to analyze the effect of the inputs modulation,the reaction was performed under low steam to methane ratio at a moderate temperature and pressure.It was obtained that to achieve process intensification is to operate the process in a periodic way.The main results show that the periodic input functions can improve the performance of the process compared to the optimal steady state operation.Moreover,there is an optimum amplitude of manipulated inputs leads to a maximum of hydrogen recovery.It is noteworthy that the comparison between the predicted performance via the sinusoidal and the square ways show that the better average performance was obtained with the square way.     

The SemSPM approach: fine integration of WS-SecurityPolicy semantics to enhance matching security policies in SOA

The lack of semantics in WS-SecurityPolicy standard hampers the effectiveness of matching security policies. To resolve this problem, we present a semantic approach for matching Web service security policies. The approach consists in the transformation of WS-SP into an OWL-DL ontology and the definition of a set of rules which automatically generate semantic relations that can exist between the provider and requestor security requirements. We show how these relations lead to more correct and refined matching of security policies. We also describe the implementation details of our approach and its validation through a real-world use case.     

Construction and Testing of an Innovative Concrete Bridge Deck Totally Reinforced with Glass FRP Bars: Val-Alain Bridge on Highway 20 East

The Val-Alain Bridge, located in the Municipality of Val-Alain on Highway 20 East, crosses over Henri River in Québec, Canada. The bridge is a slab-on-girder type with a skew angle of 20° over a single span of 49.89?m and a total width of 12.57?m. The bridge has four simply supported steel girders spaced at 3,145?mm. The deck slab is a 225-mm-thick concrete slab, with semi-integral abutments, continuous over the steel girders with an overhang of 1,570?mm on each side. The concrete deck slab and the bridge barriers were reinforced with glass fiber reinforced polymer (GFRP) reinforcing bars utilizing high-performance concrete. The Val-Alain Bridge is the Canada’s first concrete bridge deck totally reinforced with GFRP reinforcing bars. Using such nonmetallic reinforcement in combination with high-performance concrete leads to an expected service life of more than 75?years. The bridge is well instrumented with electrical resistance strain gauges and fiber-optic sensors at critical locations to record internal strain data. Also, the bridge was tested for service performance using calibrated truckloads. Design concepts, construction details, and results of the first series of live load field tests are presented.     

Changes on essential oil composition of coriander (Coriandrum sativum L.) fruits during three stages of maturity

The essential oils composition of coriander (Coriandrum sativum L.) fruits obtained by hydrodistillation was studied at three stages of maturity by GC–FID and GC–MS. Essential oil yields showed marked increase during maturation process and forty one compounds were identified. Geranyl acetate (46.27%), linalool (10.96%), nerol (1.53%) and neral (1.42%) were the main compounds at the first stage of maturity (immature fruits). At the middle stage, linalool (76.33%), cis-dihydrocarvone (3.21%) and geranyl acetate (2.85%) were reported as the main constituents. Essential oils at the final stage of maturity (mature fruits) consist mainly on linalool (87.54%) and cis-dihydrocarvone (2.36%). Additionally, accumulation of monoterpene alcohols and ketones was observed during maturation process of coriander fruit.     

Overview and investigation of the planned dynamic voltage restorer for autonomous electrical grid: Case of Adrar,south of Algeria

This paper provides an overview and study of diesel power plant (DPP) map, configuration and design in Ain-Belbel Adrar (Situated in south of Algeria) which was constructed as basis to feed the costumers by electricity in this isolated village. Its capacity of electrical production is 5 MW; this power covers the energy demand of customers connected to the electrical distribution network. First, a brief introduction of the evolution of Algeria's electrical energy consumption and power plants installed in the south is presented, followed by studies of theoretical and experimental data. Several experimental works based on simulation and primary data from field measurement are presented to show the performance of the interconnection of Diesel power plant through 15 kV distribution line to improve electrical power supply. In power system voltage sag is considered to be the most common and serious power quality issue, Due to electrical disturbances occurred through autonomous networks such as voltage sags, swells and outages in 15 kV Ain-Belbel city feeder distribution system a dynamic voltage restorer is proposed to diminish the impact of voltage perturbation in this area. DVR should inject the equivalent dropped voltage as a reflection of active power and energy into the distribution system. However, the capability of energy storage is considered how the injection energy can be minimized and the load voltage can be close to the pre-fault voltage.     

An invariant observer for a chemostat model

In this paper, we tackle the problem of designing an invariant observer for a chemostat model with adjustable and robust convergence. The main idea of the paper is to build a new class of observers for chemostat model using hidden symmetries. The effectiveness of the proposed observer is shown through simulations.     

Composition of peel essential oils from four selected Tunisian Citrus species: Evidence for the genotypic influence

The peel essential oils from four selected Tunisian Citrus species: sweet orange (Citrus sinensis Osbeck), mandarin (Citrus reticulata Blanco); sour orange (Citrus aurantium L.) and pummelo (Citrus grandis Osbeck), cultivated under the same pedoclimatic and cultural conditions have been analysed by gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS). The essential oils content ranged from 1.06% to 4.62% (w/w) in pummelo and mandarin, respectively. The qualitative and quantitative analysis led to the identification of 70 components in all oil samples. The analysed oils consist mainly in monoterpene hydrocarbons (97.59–99.3%), with limonene (92.52–97.3%) and β-pinene (1.37–1.82) being the major constituents. The remaining chemical classes were weakly represented (<1%). Both qualitative and quantitative differences between oil samples have been observed and numerous components have been proposed as marker compounds. Since the influence of different environmental factors has been eliminated, the observed chemical variability between the studied species and cultivars seems likely to results from the genetic variability.     

Effect of Temperature on the Solubility of CO2 in Bread Dough

Dough expansion during fermentation is caused by CO₂ production by yeast, and its transfer from liquid state in the dough liquor to gaseous phase in the gas cells. The liquid-gas equilibrium is controlled by the solubility of CO₂ in the dough and by the Henry coefficient. The solubility of CO₂ in bread dough was measured for different temperatures with a specific device based on the evolution of the pressure during fermentation at constant volume. The measurements range from 15 to 40°C. Data obtained was extrapolated to 0 and 50°C. Values were found between 1.6 × 10^?5 and 5 × 10^?6 g CO₂ kPa^?1 g^?1 LPD, at 0 and 50°C, respectively (LPD: Liquid Phase of Dough).