Solubilization of Phenanthrene and Fluorene in Equimolar Binary Mixtures of Gemini/Conventional Surfactants

abstract This study deals with the enhanced solubilization of polycyclic aromatic hydrocarbons (PAHs) such as phenan-threne (PHE) and fluorene (FLR) in a pure cationic gemini (G6) and three conventiona...     

Numerical and experimental analysis of natural convection flow boiling of water in internally heated vertical annulus

Numerical and experimental analysis of natural convection subcooled boiling flow in a high aspect ratio narrow vertical annulus operating at atmospheric pressure is carried out. The computational model is developed using RPI wall boiling model. The annular gap is 3.5?mm and aspect ratio is 352. A new empirical relation for nucleation site density is developed for the present geometrical configuration and implemented in the Fluent code with the help of user-defined function (UDF). The results from the numerical analysis are then compared with the experimental results which show excellent agreement. The wall superheat is found to be maximum at the point of boiling incipience which increases with heat input. The wall temperature shows a gradual decrease in the boiling region. The average heat transfer coefficient increases almost linearly for both subcooled and saturated boiling region.     

Sargassum swartzii extracts ameliorate memory functions by neurochemical modulation in a rat model

Food Science and Biotechnology - Recently, considerable attention has been paid to drug exploration from natural sources for treating memory loss, a major manifestation of various neurodegenerative...     

An approach to locational marginal price based zonal congestion management in deregulated electricity market

Congestion of transmission line is a vital issue and its management pose a technical challenge in power system deregulation. Congestion occurs in deregulated electricity market when transmission capacity is not sufficient to simultaneously accommodate all constraints of power transmission through a line. Therefore, to manage congestion, a locational marginal price (LMP) based zonal congestion management approach in a deregulated electricity market has been proposed in this paper. As LMP is an economic indicator and its difference between two buses across a transmission line provides the measure of the degree of congestion, therefore, it is efficiently and reliably used in deregulated electricity market for congestion management. This paper utilizes the difference of LMP across a transmission line to categorize various congestion zones in the system. After the identification of congestion zones, distributed generation is optimally placed in most congestion sensitive zones using LMP difference in order to manage congestion. The performance of the proposed methodology has been tested on the IEEE 14-bus system and IEEE 57-bus system.     

Utilization of ZSM-5/MCM-41 composite as FCC catalyst additive for enhancing propylene yield from VGO cracking

A micro-mesoporous ZSM-5/MCM-41 composite molecular sieve (ZM13) was synthesized and tested as an FCC catalyst additive to enhance the yield of propylene from catalytic cracking of vacuum gas oil (VGO). The catalytic performance of the additive was assessed using a commercial equilibrium USY FCC catalyst (E-Cat) in a fixed-bed micro-activity test unit (MAT) at 520?°C and various catalyst/oil ratios. MCM-41, ZSM-5 and two ZSM-5/MCM-41 composites were systematically characterized by complementary techniques such as XRD, BET, FTIR and SEM. The characterization results showed that the composites contained secondary building unit with different textural properties compared to pure ZSM-5 and MCM-41. MAT results showed that the VGO cracking activity of E-Cat did not decrease by using these additives. The highest propylene yield of 12.2 wt% was achieved over steamed ZSM-5/MCM-41 composite additive (ZM13) compared with 8.6 wt% over conventional ZSM-5 additive at similar gasoline yield penalty. The enhanced production of propylene over composite additive was attributed to its mesopores that suppressed secondary and hydrogen transfer reactions and offered easier transport and accessibility to active sites. Gasoline quality was improved by the use of all additives except MCM-41, as octane rating increased by 6?C12 numbers.     

Seismic Behavior of As-Built, ACI-Complying, and CFRP-Repaired Exterior RC Beam-Column Joints

In this paper, the efficiency and effectiveness of carbon-fiber-reinforced polymer (CFRP) sheets for upgrading the shear strength and ductility of a seismically deficient exterior beam-column joint were studied and compared with an American Concrete Institute (ACI)-based design joint specimen. One as-built joint specimen, representing the preseismic code design and construction practice for joints and one ACI-based design joint specimen, satisfying the seismic design requirements of the current code of practice were cast. The as-built specimen was used as baseline (control) specimen. These two specimens (i.e., the as-built control and the ACI-based specimens) were subjected to cyclic lateral load histories to induce damage equivalent to damage expected from a severe earthquake. The damaged control specimen was then repaired by filling its cracks with epoxy and externally bonding CFRP sheets to the joint, the beam, and part of the column regions. This specimen was identified as the repaired specimen. The repaired specimen was subjected to a similar cyclic lateral load history, and its response history was recorded. The response histories of the as-built control, the repaired, and the ACI-based design specimen were then compared. The test results demonstrated that externally bonded CFRP sheets can effectively improve both the shear strength and the deformation capacity of seismically deficient and damaged beam-column joints to a state comparable to the ACI-based design joint.     

Durability of LDPE nanocomposites with clay,silica, and zinc oxide II. weatherability of the nanocomposites

Three LDPE nanocomposites based on the nanoscale fillers, montmorillonite clay, silica, and zinc oxide were studied to determine if the reinforcement they imparted was accompanied by any change in the weatherability of the nanocomposite. Changes in weathering behavior were monitored in samples exposed to natural weathering outdoors over a period of 24 months of exposure. Because of superior light‐shielding afforded by the high specific surface area of nanofillers a stabilization effect might be anticipated. Alternatively chemical effects may enhance weatherability. In all three nanocomposites studied, the weatherability compared to unfilled LDPE did not significantly change due to the presence of 5 wt% of the nanofillers. The efficient reinforcement afforded by the nanofillers is not accompanied by a loss or enhancement in durability of the material. POLYM. COMPOS., 34:1878–1883, 2013. © 2013 Society of Plastics Engineers     

HYDROMAGNETIC UNSTEADY RIVLIN-ERICKSEN THIRD-GRADE FLOW FOR STOKES' SECOND PROBLEM

In this article, the flow of an unsteady third-grade Rivlin-Ericksen fluid on an oscillating plate is discussed. The magnetic lines of force act perpendicular to the flow field. Several interesting features of the flow are obtained. The physical interpretation of the second-grade parameters, third-grade parameters, oscillating frequency, and magnetohydrodynamic parameters are examined graphically and then are deduced to already known results in the literature.     

Effect of Trapping on Vortices in Plasma

Microscopic trapping of electrons is considered in one- and two-dimensional potential wells (shallow and deep) and its effect on vortex formation is investigated by deriving modified Hasegawa Mima (HM) equations. Inhomogenieties in the number density and magnetic field are taken into account. The modified HM equations are analysed by considering bounce frequencies of the trapped particles. Solitary vortices are obtained via Kortweg deVries (KdV) type of equations and both exact and Sagdeev potential solutions are obtained. In general it is observed that trapping produces stronger non-linearities and this leads to the modification of the original HM equation.