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111.
Load balancing is a crucial factor in IPTV delivery networks. Load balancing aims at utilizing the resources efficiently, maximizing the throughput, and minimizing the request rejection rate. The peer-service area is the recent architecture for IPTV delivery networks that overcomes the flaws of the previous architectures. However, it still suffers from the load imbalance problem. This paper investigates the load imbalance problem, and tries to augment the peer-service area architecture to overcome this problem. To achieve the load balancing over the proposed architecture, we suggest a new load-balancing algorithm that considers both the expected and the current load of both contents and servers. The proposed load-balancing algorithm consists of two stages. The first stage is the contents replication according to their expected load, while the second stage is the content-aware request distribution. To test the effectiveness of the proposed algorithm, we have compared it with both the traditional Round Robin algorithm and Cho algorithm. The experimental results depict that the proposed algorithm outperforms the two other algorithms in terms of load balance, throughput, and request rejection rate. 相似文献
112.
Hiba Messaoudi Fayçal Djazi Mohamed Litim Bahadır Keskin Maamar Slimane Djillali Bekhiti 《Journal of Adhesion Science and Technology》2020,34(20):2216-2244
AbstractCorrosion inhibitors based on environmentally friendly and harmless products are currently being studied and developed. The corrosion inhibition properties of caffeine (1,3,7-trimethylxanthine) on copper corrosion in aqueous chloride solution (3.5?wt.% NaCl) are analysed here using stationary and transient electrochemical methods, and a theoretical study based on density functional theory is carried out. Caffeine is a very competitive compared to the chemical inhibitors that are often used for copper protection. Electrochemical and impedance experiments reveal that the protective efficiency of caffeine reaches a value of 96% at a concentration of 10?2?mol L?1. Based on these results, the Langmuir model appears to be the best representation of the adsorption of caffeine onto the copper surface. Scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy and X-ray diffraction (XRD) were used to determine the surface morphology and the chemical composition of the copper surface in chloride media, in the absence and presence of caffeine. The results show the development of a mechanism of corrosion inhibition. In order to confirm the correlation between the inhibitory effect and the molecular structure of caffeine, quantum chemical parameters are used to calculate its electronic properties. 相似文献
113.
Mohamed Zerrougui Mohamed Darouach Latifa Boutat-Baddas Harouna Souley Ali 《International Journal of Control, Automation and Systems》2014,12(3):590-598
In this paper, we consider the H ∞ filters design for singular bilinear systems. The approach is based on the parameterized solution of a set of constrained Sylvester equations. The exponential convergence and l 2 gain attenuation problems are solved by using the bounded real lemma, which leads to linear matrix inequalities (LMI) formulation. Finally, a detailed design procedure is given for the estimation of the states of a flexible joint robot, which demonstrates the effectiveness of the proposed method. 相似文献
114.
Mahesh Gupta Yogesh Jaluria Valentinas Sernas Mohamed Esseghir Tai H. Kwon 《Polymer Engineering and Science》1993,33(7):393-399
The univariant element, Q1 P0, and the multivariant elements, QP0 and R P0, are compared for the numerical simulation of the flow in extrusion dies. The pressure distribution obtained by using the Q1 P0 element was found to be afflicted with the checkerboard pressure mode. On the other hand, the multivariant elements, Q P0 and R P0, gave accurate and physically reasonable velocity and pressure distributions. The computed values of the pressure drop across extrusion dies matched well with the pressure drop determined experimentally. 相似文献
115.
The effect of the N-linked glycans on structural features and physicochemical functions of soybean β-conglycinin homotrimers 总被引:2,自引:0,他引:2
Nobuyuki Maruyama Mohamad Ramlan Mohamed Salleh Koji Takahashi Kazuhiro Yagasaki Hideyuki Goto Naho Hontani Shuko Nakagawa Shigeru Utsumi 《Journal of the American Oil Chemists' Society》2002,79(2):139-144
β-Conglycinin is a trimeric protein consisting of three subunits, α,α′,and β, which are N-glycosylated. The α and α′ subunits
contain extension regions in addition to core regions common to all subunits. We purified homogeneous trimers consisting of
only α, α′, or β from mutant soybean cultivars containing β-conglycinin lacking one or two subunits: α homotrimers from an
α′-lacking mutant, α′ homotrimers from an α-lacking mutant, and β homotrimers from an α-and α′-lacking mutant. Structural
features and physicochemical functions of the three homotrimers were examined and compared with those of recombinant homotrimers
having no N-linked glycans. The native homotrimers have secondary structures very similar to those of the recombinant ones.
In analogy with the recombinant homotrimers, the native ones exhibit different thermal stabilities from one another (β>α′>α),
and the native α and α′ homotrimers exhibit better solubility, emulsifying ability, and heat-induced association than the
native β homotrimer. Further, the N-linked glycans contribute to solubilities of the three subunits at low ionic strength
(μ=0.08) and to the emulsifying ability of the native β homotrimer. N-Linked glycans also prevent heat-induced associations
of the native α and α′ homotrimers but do not contribute to the secondary structure and the thermal stability of β-conglycinin. 相似文献
116.
Wheat gluten (10 g) was crosslinked (XL) using 10 units of transglutaminase. Different blends of XL gluten and poly(lactic acid) (PLA) were mixed in a Brabender mixer at 180°C for 10 min. Neat PLA and blends were analyzed using modulated DSC (MDSC). Neat PLA displayed a glass transition (Tg) and exothermic (Cry) followed by endothermic (Mel) transitions. The profile showed a Tg of 0.46 J/g/°C, Cry with 29.9 J/g, whereas Mel exhibited 28.7 J/g. XL wheat gluten displayed one Tg with 0.45 J/g/°C. Samples were subjected to repeated heating and cooling cycles to show the level of compatibility between the two polymers. The activation energy (Ea) and pre‐exponential factor (Z) were determined according to Borchardt and Daniels (B/D) kinetics approach. The blends showed increased Ea values with an increase in the amount of XL gluten. In the presence of 5 and 20% XL gluten, the Ea of PLA increased from 150 to 200 kJ/mol, respectively. A higher number of cycles caused an increase in Ea. The Tg temperature of different PLA/XL gluten blends can be predicted by Gordon–Taylor equation and its modified forms. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 相似文献
117.
In Gulf countries, most power plants are co-generation power desalting plants (CPDP) that generate electric energy and also produce fresh water through the desalination of seawater. This paper provides detailed technical and economical analyses to evaluate a new generation of dual purpose technology that includes the integration of reverse osmosis (RO) processes with existing thermal desalination processes and power generation (triple hybrid system) at Layyah plant, Sharjah, UAE. Hybridization of sweater reverse osmosis (SWRO) and the multi-stage flash (MSF) technology was considered to improve the performance of latter and reduce the cost of the produced water. Moreover, “idle” power in winter (seasonal surplus of unused power) was mainly utilized by RO to further reduce the cost of the hybrid system for six months of the year. Spinning reserve was also used to further reduce the cost of the proposed hybrid system. Integration ofthe three processes of MSF, MED, and RO desalination technologies could be made at different levels through which the resulting of water cost will depend on the selected configuration and the cost of materials of construction, equipment, membrane, energy, etc. Thus, the capital and annual operating costs were calculated for all potential alternatives for various plant capacities. It was found that for all plant capacities, integrated hybrid systems resulted in most cost effective solution. For example, at a capacity of 50 MIGD, the present worth of the cost was calculated to be 588.7, 443.2, and 380 million US$ for MSF, MED, and hybrid RO systems, respectively. 相似文献
118.
Abdellatif Mohamed Mila P. Hojilla-Evangelista Steve C. Peterson Girma Biresaw 《Journal of the American Oil Chemists' Society》2007,84(3):281-288
Barley protein isolate (BPI) was extracted in 0.015 N NaOH in a 10:1 ratio solvent:flour and was precipitated by adjusting
the pH to 4.5 and freeze-dried. The thermal properties of BPI were determined using modulated differential scanning calorimetry
(MDSC). BPI with 4% moisture content exhibited a glass transition (T
g) with 140 °C onset, 153 °C middle, and 165 °C end temperatures and a ΔC
p of 0.454 J/g per °C. The high moisture content sample (50%) showed a T
g at 89, 91, or 94 °C and 0.067 ΔC
p. Acetylation had no apparent effect on the foaming and emulsifying properties of protein from barley flour but exhibited
the least-stable foam among BPI samples. Foaming capacities of both barley protein isolates were ∼12% less than that of acid-precipitated
soy protein isolate reported in the literature. Acetylated BPI showed the highest surface hydrophobicity compared to the other
samples. The surface-tension test confirmed that unmodified and modified BPI possessed surface activity. BPI phosphorous oxycloride-crosslinked
was the most effective in lowering the surface tension of aqueous NaCl, while the crosslinked BPI was the least effective.
The G′ value of BPI suspension was greater than G″ at all frequencies from 0.1 to 100 rad/s. The strain value at which linear behavior ceased and nonlinear behavior began
ranged from 3 to 10%.
Names are necessary to report factually on available data; however, the United States Department of Agriculture (USDA) neither
guarantees nor warrants the standard of the product, and the use of the name by the USDA implies no approval of the product
to the exclusion of others that may also be suitable. 相似文献
119.
Ghurmallah H. Al‐Ghamdi E. David Sudol Victoria L. Dimonie Mohamed S. El‐Aasser 《应用聚合物科学杂志》2006,101(5):3479-3486
Miniemulsion copolymerization of styrene/n‐butyl acrylate was investigated as a means of encapsulating hydrophilic titanium dioxide (TiO2) in a film‐forming polymer. Dispersion studies of the TiO2 were first carried out to determine the choice of stabilizer, its concentration, and the dispersion process conditions for obtaining stable TiO2 particles with minimum particle size. Through screening studies of various functional stabilizers and shelf‐life stability studies at both room and polymerization temperatures, Solsperse 32,000 was selected to give relatively small and stable TiO2 particles at 1 wt % stabilizer and with 20–25 min sonification. The subsequent encapsulation of the dispersed TiO2 particles in styrene/n‐butyl acrylate copolymer (St/BA) via miniemulsion polymerization was carried out and compared with a control study using styrene monomer alone. The lattices resulting from the miniemulsion encapsulation polymerizations were characterized in terms of the encapsulation efficiencies (via density gradient column separations; DGC) and particle size (via dynamic light scattering). Encapsulation efficiencies revealed that complete encapsulation of all of the TiO2 by all of the polymer was not achieved. The maximum encapsulation efficiencies were 79.1% TiO2 inside 61.7% polystyrene and 63.6% TiO2 inside 38.5% St/BA copolymer. As the density of the particles collected from the DGC increased from one layer to another, both the average particle size and the number of the TiO2 particles contained in each latex particle increased. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3479–3486, 2006 相似文献
120.
This study examined the individual and simultaneous adsorption of SO{in{itx}} (SO{in{it2}}) and NO{in{itx}} (NO-NO{in{it2}})
on activated carbon prepared from waste palm shell. The adsorption process was examined in a fixed bed reactor at low temperatures
(100\2-300\dgC). For individual adsorption without any catalytic activation, SO{in{itx}} showed good adsorption whereas NO{in{itx}}
was very much poor. In the simultaneous adsorption of SO{in{itx}} and NO{in{itx}}, SO{in{itx}} showed greater adsorption affinity
than NO{itx}. For palm shell activated carbon (PSAC) impregnated with metal catalyst (Ni and Ce) the concentration adsorbed
profile showed that the amount of SO{in{itx}} adsorbed decreased regularly, while the amount of the adsorbed NO{in{itx}} increased
irregularly. The properties of the pure and impregnated PSAC were analyzed by BET, SEM and EDX. These investigations indicated
that PSAC impregnated with metal catalyst is the determining factor in the adsorption of SO{in{itx}} and NO{in{itx}} simultaneously.
Supported financially by Yayasan FELDA, Malaysia (Grant No. 6050075) 相似文献