Static load-balanced routing for slimmed fat-trees

Slimmed fat-trees have recently been proposed and deployed to reduce costs in High Performance Computing (HPC) clusters. While existing static routing schemes such as destination-mod-k (D-mod-k) routing are load-balanced and effective for full bisection bandwidth fat-trees, they incur significant load imbalance in many slimmed fat-trees. In this work, we propose a static load balanced routing scheme, called Round-Robin Routing (RRR$RRR$), for 2$2$- and 3$3$-level extended generalized fat-trees (XGFTs), which represent many fat-tree variations including slimmed fat-trees. RRR$RRR$ achieves near perfect load-balancing for any such XGFT in that links at the same level of a tree carry traffic from almost the same number of source–destination pairs. Our evaluation results indicate that on many slimmed fat-trees, RRR$RRR$ is significantly better than D-mod-k for dense traffic patterns due to its better load-balancing property, but performs worse for sparse patterns. We develop a combined routing scheme that enjoys the strengths of both RRR$RRR$ and D-mod-k by using RRR$RRR$ in conjunction with D-mod-k. The combined routing is a robust load-balanced routing scheme for slimmed fat-trees: it performs similar to D-mod-k for sparse traffic patterns and to RRR$RRR$ for dense patterns.     

Optimization of a tubular nylon 6 reactor with radial gradients

Optimal jacket-fluid temperature profiles for tubular Nylon 6 reactors (in the presence of radial gradients of temperature and concentration) have been obtained using an algorithm based on the continuous minimum principle developed for a distributed parameter system. A gradient search technique has been devised and implemented for obtaining these optimal profiles. The optimal temperature profiles are found to be at the maximum permissible temperature, T_max, at the beginning of the reactor and then slowly decrease to the minimum permissible temperature, T_min, near the end of the reactor. The effect of varying several parameters is also studied. The desired value of the chain length and the reaction time are found to be the parameters which effect the optimal profiles most significantly.     

Simulation and optimization of the continuous tower process for styrene polymerization

The continuous tower process, a popular industrial process for the manufacture of polystyrene, was simulated and optimized. A kinetic model for the thermal polymerization of styrene, which takes into account the Trommsdorff effect and the volume change accompanying the reaction, was developed. This was used to formulate model equations for the continuous flow stirred tank reactor (CSTR) and plug flow reactor (several sections) in the tower process. The model can predict monomer conversion, number‐ and weight‐average molecular weights, polydispersity index (PDI), and temperature at various locations in the unit, under specified operating conditions. Multiobjective optimization of this process was also carried out, for which an adaptation of a genetic algorithm (GA) was used. The two objectives were maximization of the final monomer conversion and minimization of the PDI of the product. The conversion in the CSTR was constrained to lie within a desired range, and polymer having a specified value of the number‐average molecular weight was to be produced. The optimal solution was a unique point (no Pareto sets were obtained). The optimal solutions indicated that the tower process is operated under near‐optimal conditions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 775–788, 2004     

Effect of Benzheterazoles on the Micellar Behavior of Sodium Dodecylsulfate in Dimethylsulfoxide: A Conductometric and Spectroscopic Approach

In this article, we report intermolecular interactions in terms of the effect of benzfused heterocyclic compounds, i.e., 2-thioureidobenzimidazole and 2-thioureidobenzoxazole (0.00, 0.01, and 0.05 mol kg⁻¹), on the micellization behavior of sodium dodecylsulphate (SDS) (1–52 mmol kg⁻¹) in dimethylsulphoxide (DMSO) at different temperatures (293.15–313.15 K) through conductometric and spectroscopic investigations. The variation of specific conductance with SDS concentration has been utilized to estimate the critical micelle concentration ( CMC). The above-performed techniques infer that the presence of additives results in a decrease in the CMC values. Various standard thermodynamic parameters such as free energy change (), enthalpy change (), and entropy change () of micellization have been determined using the temperature dependence of CMC. The above calculated parameters and also UV–visible and fluorescence spectroscopy have been used to obtain information regarding the various interactions between the compounds and surfactant aggregates. In addition, an attempt has also been made to examine the minimum inhibitory concentration (MIC) of the heterocompounds, which indicates the effectiveness of these compounds against fungus growth at a particular concentration. These synthetic heterocyclic compounds find increasing applications in material science, medicinal chemistry, and biochemistry due to their antifungal and antioxidant properties.     

Superconducting Performance,Structure, Microstructure,and Trapped Field of Top-Seeded Melt-Processed Bulk Y<Subscript>3</Subscript>Ba<Subscript>5</Subscript>Cu<Subscript>8</Subscript>O<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>

The sintering temperature for the production of Y₃Ba₅Cu₈O₁₈ (Y-358) preform powders synthesized in sol-gel spontaneous combustion technique was optimized. A large single-grain bulk Y-358 crystal was fabricated employing a top-seeded melt-growth technique utilizing the optimally sintered preform powders (i.e., at 900 ^°C for 12 h). Structural, microstructural, elemental, and magnetic properties were investigated by means of X-ray diffraction, scanning electron microscopy, and SQUID, respectively. The structural characterization indicated that the sample is highly textured in (00l) direction. The Y-358 phase fractions were estimated in both preform powders and bulk sample using Rietveld refinement. The onset of superconducting transition is observed at 92.5 K, and the curve is very sharp indicative of the high quality of the produced bulk sample. The field dependence of critical current density (J_c) was determined at 77 K, and the self-field J_c was found to be ～26 kA/cm². A magnetic field of 0.27 T was trapped by the sample at 77 K.     

A novel quantum-inspired evolutionary view selection algorithm

A data warehouse (DW) is designed primarily to meet the informational needs of an organization’s decision support system. Most queries posed on such systems are analytical in nature. These queries are long and complex, and are posed in an exploratory and ad-hoc manner. The response time of these queries is high when processed directly against a continuously growing DW. In order to reduce this time, materialized views are used as an alternative. It is infeasible to materialize all views due to storage space constraints. Further, optimal view selection is an NP-Complete problem. Alternately, a subset of views, from amongst all possible views, needs to be selected that improves the response time for analytical queries. In this paper, a quantum-inspired evolutionary view selection algorithm (QIEVSA) that selects Top-K views from a multidimensional lattice has been proposed. Experimental comparison of QIEVSA with other evolutionary view selection algorithms shows that QIEVSA is able to select Top-K views that are comparatively better in reducing the response times for analytical queries. This in turn aids in efficient decision making.     

Thermoreversible nanoethosomal gel for the intranasal delivery of Eletriptan hydrobromide

The objective of the current study was to formulate and characterize thermoreversible gel of Eletriptan Hydrobromide for brain targeting via the intranasal route. Ethosomes were prepared by 3² factorial design with two independent variables (concentration of soya lecithin and ethanol) and two response variables [percent entrapment efficiency and vesicle size (nm)] using ethanol injection method. Formulated ethosomes were evaluated for preliminary microscopic examination followed by percent drug entrapment efficiency, vesicle size analysis, zeta potential, polydispersibility index and Transmission electron microscopy (TEM). TEM confirms spherical morphology of ethosomes, whereas Malvern zeta sizer confirms that the vesicle size was in the range of 191 ± 6.55–381.3 ± 61.0 nm. Ethosomes were incorporated in gel using poloxamer 407 and carbopol 934 as thermoreversible and mucoadhesive polymers, respectively. Ethosomal gels were evaluated for their pH, viscosity, mucoadhesive strength, in vitro drug release and ex vivo drug permeation through the sheep nasal mucosa. Mucoadhesive strength and pH was found to be 4400 ± 45 to 5500 ± 78.10 dynes/cm² and 6.0 ± 0.3 to 6.2 ± 0.1, respectively. In-vitro drug release from the optimized ethosomal gel formulation (G4) was found to be almost 100 % and ex vivo permeation of 4980 µg/ml with a permeability coefficient of 11.94 ± 0.04 × 10^?5 cm/s after 24 h. Histopathological study of the nasal mucosa confirmed non-toxic nature of ethosomal gels. Formulated EH loaded ethosomal thermoreversible gel could serve as the better alternative for the brain targeting via the intranasal route which in turn could subsequently improve its bioavailability.     

Enhancement of heat transfer by water–Al2O3 and water–TiO2 nanofluids jet impingement in cooling hot steel surface

Two different nanofluids, namely water–Al₂O₃ and water–TiO₂, were impinged in the form of jet on hot steel surface to remove high heat flux, and their performance was compared. The dimension of the test steel sample was 120 mm × 120 mm and 4 mm thickness. Four K-type thermocouples were embedded on the bottom surface of the plate to measure the transient temperature distribution. The time-temperature data were recorded by the help of a data acquisition system (make: CHINO, model: KR2000), and the results were analysed by ZAILA application software. Effect of impinging nanofluids with weight concentrations of 0.01%, 0.03%, 0.05% and 0.07% Al₂O₃ and TiO₂ nanoparticles on heat transfer from the hot surface was tested. The surface heat transfer coefficient (HTC) was computed from the time-temperature history recorded during experimentation. Experimental results revealed that addition of nanoparticles to the base fluid (water) surprisingly enhanced the heat transfer rate and HTC as expected. The heat transfer rate increased up to certain limit of nanoparticle concentrations, and then declined. Application of nanofluids for the steel strip cooling was found very effective in terms of heat transfer phenomena as compared to the conventional fluid cooling methods.     

An anisotropic propagation technique for synthesizing hyperbranched polyvillic gold nanoparticles

Of late, many synthesis processes have been studied to develop irregular nano-morphologies of gold nanostructures for biomedical applications in order to increase the efficacy of nanoparticle theranostics, tune the plasmonic absorbance spectra, and increase the sensitivity of biomolecule detection through surface enhanced Raman spectroscopy. Here we report, a novel, non-seed mediated versatile single pot synthesis method capable of producing hyperbranched gold “nano-polyvilli” with more than 50–90 branching nanowires propagating from a single origin within each structure. The technique was capable of achieving precise tuning of the branch propagation where the branching could be controlled by varying the duration of incubation, temperature, and hydrogen ion concentration.

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Effect of different acid oxidation on morphology,dispersion and optical band-gap of multi-walled carbon nanotubes

In this paper the effect of different acid oxidation on morphology, dispersion and optical band gap of multi-walled carbon nanotubes (CNTs) is reported. Oxidation of CVD synthesized MWCNTs were carried out in 8M HNO₃, 8M H₂SO₄, 8M HNO₃/H₂O₂ and 8M H₂SO₄/HNO₃. Oxidized nanotubes sample were characterized by XRD, SEM, FT-IR, TGA, UV-Vis spectroscopy and Raman analysis. Oxidized-nanotubes show a lower shift in XRD peak and an increase in d-spacing, which implies deterioration of MWNTs. New peaks in FT-IR spectra of oxidized-nanotube samples at around 1742 cm^?1 confirms the presence of carbonyl groups. Optical bandgap, molar absorptivity coefficient is estimated for pristine and oxidized nanotubes sample using UV-Vis spectroscopy data and Tauc plot. It is observed that optical bandgap decreases on oxidation and lowest bandgap 2.92 eV is observed for H₂SO₄ treated MWNTs. The information on the optical bandgap of the MWNTs is of great importance for the development of optoelectronic devices.