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1.
Explicit boundary dissipative conditions are given for the exponential stability in -norm of one-dimensional linear hyperbolic systems of balance laws over a finite interval, when the matrix is marginally diagonally stable. The result is illustrated with an application to boundary feedback stabilisation of open channels represented by linearised Saint–Venant–Exner equations. 相似文献
2.
Magatte Diagne Mamadou Gueye Anicet Dasilva Loic Vidal Adams Tidjani 《Journal of Materials Science》2006,41(21):7005-7010
Nanocomposites of polypropylene-graft-maleic anhydride/clay were prepared by melt blending in an extruder mixer. The nanoscale dispersion of the clay in the polymer was analysed by wide-angle X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results of XRD and TEM showed that the nanocomposites obtained were a kind of intercalated-delaminated structures side by side with different dominant states, depending on the clay used and on the processing conditions. The consequences of photo-oxidation on the thermal stability and fire retardant properties of the nanocomposites were investigated using thermogravimetric analysis and cone calorimetry tests. It appeared that this degradation dramatically affected the important properties of the nanocomposites. A loss of thermal stability and fire retardant performance was observed. This was ascribed to scission reactions that occurred during the oxidative degradation prior to thermal and fire tests. 相似文献
3.
The study assessed the causal effects of NERICA adoption on rice yields and income, using country-wide data of 600 rice farmers
in The Gambia. To control for differences in socio-demographic and environmental characteristics of adopters and non-adopters
and enable a causal interpretation of NERICA adoption on the variables of interest, the study used the counterfactual outcome
framework to control for such differences. The results, based on observed sample estimates, showed significant differences
in rice yields and income between the NERICA adopters and non-adopters. Further, the results of the framework, based on the
Local Average Treatment Effect (LATE) estimates, which allowed a causal interpretation, showed that NERICA adoption significantly
increased average rice yields and annual income of small-scale rice farmers by 157 kg per hectare and $148, respectively. 相似文献
4.
In vivo intestinal perfusion was used to follow the absorption of three different choline glycerophospholipids (CGP) in guinea
pig. These included 1-[3H]palmitoyl-2-acyl-sn-glycero-3-phosphocholine (diacyl-GPC), 1-[3H]-O-hexadecyl-2-acyl-sn-glycero-3-phosphocholine (alkylacyl-GPC) and 1,2-di-O-hexadecyl-sn-glycero-3-phospho-[3H]-choline (dialkyl-GPC). About 80% of diacyl-GPC was absorbed within 4 hr, compared to 60% of alkylacyl-GPC and 30% of dialkyl-GPC.
The radioactivity disappearing from the perfusion fluid was recovered in intestinal lipids, mostly triacylglycerol, free fatty
acid and CGP from diacyl-GPC, CGP from alkylacyl-GPC and dialkyl-GPC. These results indicated that the nonhydrolyzable substrate
dialkyl-GPC was much less absorbed, whereas diacyl-GPC, which released over 80% of [3H]palmitic acid in the perfusion fluid, displayed the highest absorption rate. The intermediate picture observed for alkylacyl-GPC
suggested the possible involvement of a phospholipase A2, which was detected in the entire intestinal tract. This enzyme was further found to concentrate in villus cells, where it
is localized in the brush border membrane, as shown using two different subcellular fractionation procedures. These data suggest
a possible role of this new enzyme in the digestion of alimentary phospholipids. 相似文献
5.
Christophe Brun Pierre‐Henri Elchinger Guillaume Nonglaton Cheikh Tidiane‐Diagne Raluca Tiron Aurélie Thuaire Didier Gasparutto Xavier Baillin 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(33)
Metallic conductive nanowires (NWs) with DNA bundle core are achieved, thanks to an original process relying on double‐stranded DNA alignment and physical vapor deposition (PVD) metallization steps involving a silicon substrate. First, bundles of DNA are suspended with a repeatable process between 2 µm high parallel electrodes with separating gaps ranging from 800 nm to 2 µm. The process consists in the drop deposition of a DNA lambda‐phage solution on the electrodes followed by a naturally evaporation step. The deposition process is controlled by the DNA concentration within the buffer solution, the drop volume, and the electrode hydrophobicity. The suspended bundles are finally metallized with various thicknesses of titanium and gold by a PVD e‐beam evaporation process. The achieved NWs have a width ranging from a few nanometers up to 100 nm. The electrical behavior of the achieved 60 and 80 nm width metallic NWs is shown to be Ohmic and their intrinsic resistance is estimated according to different geometrical models of the NW section area. For the 80 nm width NWs, a resistance of about few ohms is established, opening exploration fields for applications in microelectronics. 相似文献
6.
MH Sy O Diarra M Diagne MM Diouf P Sene S Diouf 《Canadian Metallurgical Quarterly》1996,39(4-5):208-212
Lunotriquetral coalition is a congenital carpal anomaly rarely discovered in a white population. In the black population, most cases have concerned blacks in America, Australia and South Africa. In the Sub-Saharia area, in Senegal, the authors, after 8 incidental cases, report 32 lunotriquetral coalitions collected in 20 patients. This retrospective study comparatively analysed 361 X-rays of the wrist performed between February 1989 and July 1992 in the Orthopaedic and Traumatologic Center (CTO) in Dakar. The bony coalition was bilateral in 12 patients and unilateral in the other 8 cases. The complete form (type III) was the most frequent (46.8%). In the bilateral forms, 5 patients presented this complete form. Lunotriquetral coalition was associated, in absence of congenital abnormalities, with a synovial cyst of the wrist (2 cases), scaphoid fracture (1 case), non-union of a scaphoid fracture (1 case) and osteoarthritis of the wrist (2 cases). After review of the literature, the authors discuss racial factors, anatomo-radiographic forms and associated injuries. 相似文献
7.
Doudou Diagne Motonobu Goto Tsutomu Hirose 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1996,65(1):29-38
The simultaneous removal and concentration of carbon dioxide present in ambient air were carried out by a dual refluxed Pressure Swing Adsorption (PSA) process with intermediate feed inlet position. The feed inlet position divides each column into rectifying and stripping sections from which enriched and lean gases can be simultaneously produced. A simple isothermal model with negligible axial dispersion and pressure drops through the PSA beds was developed to investigate the effects of various combinations of the operating variables and to analyze semi-quantitatively the effects of the main characteristic parameters such as the dimensionless feed inlet position (ZR/LT) and the stripping-reflux ratio (Rr). A good agreement between the model prediction and the experimental results was obtained. Moreover, an optimum feed inlet position was found and it corresponded to a position where the carbon dioxide mole ratio in the feed flux and that in the upstream flux leaving the stripping section were equal. The carbon dioxide mole ratio in the enriched product (YE) as well as that in the lean product (YL) were strongly dependent on the ratio of feed/enriched product flow rates (QF/QE) and the ratio of feed/lean product flow rates (QF/QL). Although the pressure ratio (Pa/Pd) was crucially important for the separation performance, a smaller value of Rr was sufficient to reach a performance which is unattainable in conventional PSA processes. 相似文献
8.
Fabien Prgaldiny Franois Krummenacher Birahim Diagne Franois Pêcheux Jean‐Michel Sallese Christophe Lallement 《International Journal of Numerical Modelling》2006,19(3):239-256
This paper presents a new compact model for the undoped, long‐channel double‐gate (DG) MOSFET under symmetrical operation. In particular, we propose a robust algorithm for computing the mobile charge density as an explicit function of the terminal voltages. It allows to greatly reduce the computation time without losing any accuracy. In order to validate the analytical model, we have also developed the 2D simulations of a DG MOSFET structure and performed both static and dynamic electrical simulations of the device. Comparisons with the 2D numerical simulations give evidence for the good behaviour and the accuracy of the model. Finally, we present the VHDL‐AMS code of the DG MOSFET model and related simulation results. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
9.
Polyelectrolyte and silver nanoparticle modification of microfiltration membranes to mitigate organic and bacterial fouling 总被引:1,自引:0,他引:1
Diagne F Malaisamy R Boddie V Holbrook RD Eribo B Jones KL 《Environmental science & technology》2012,46(7):4025-4033
Membrane fouling remains one of the most problematic issues surrounding membrane use in water and wastewater treatment applications. Organic and biological fouling contribute to irreversible fouling and flux decline in these processes. The aim of this study was to reduce both organic and biological fouling by modifying the surface of commercially available poly(ether sulfone) (PES) membranes using the polyelectrolyte multilayer modification method with poly(styrenesulfonate) (PSS), poly(diallyldimethylammonium chloride) (PDADMAC), and silver nanoparticles (nanoAg) integrated onto the surface as stable, thin (15 nm) films. PSS increases the hydrophilicity of the membrane and increases the negative surface charge, while integration of nanoAg into the top PSS layer imparts biocidal characteristics to the modified surface. Fouling was simulated by filtering aqueous solutions of humic acid (5 and 20 mg L(-1)), a suspension of Escherichia coli (10(6) colony-forming units (CFU) mL(-1)), and a mixture of both foulants through unmodified and modified PES membranes under batch conditions. Filtration and cleaning studies confirmed that the modification significantly reduced organic and biological fouling. 相似文献
10.
In order to be competitive, telecommunications service providers need new technologies that facilitate the rapid introduction of validated services in a cost-effective manner. Service engineering is a new discipline in which the telecommunications sector addresses the technologies and engineering processes required for service creation. Concurrent with these studies the development of applications in the Internet shows a new way to design telecommunications services based on the mobile agent paradigm. This brings new concepts that fit the requirements of service engineering. Therefore merging the approaches enables improvement of the service creation process. We illustrate this by presenting a framework for the formal design of telecommunications services using mobile agent technology complemented with formal methods. The contribution of this work is twofold. First, it relies on the Reference Model of Open Distributed Processing (RM-ODP) and shows how to adapt its concepts to agent orientation. Second, it provides agent-based service designers with validation and verification tools to state the quality of their specifications 相似文献