GAPSO-SVM: An IDSS-based Energy-Aware Clustering Routing Algorithm for IoT Perception Layer

Wireless Personal Communications - With the emergence of Internet of Things (IoT) having large scale and generating huge amount of data, Intelligent Decision Support Systems (IDSSs) have attracted...     

Prediction of mass transfer coefficients in a pulsed disc and doughnut extraction column

A study of the mass transfer performance for a pulsed disc and doughnut extraction column has been presented for a range of operating conditions. The mass transfer performance has been investigated for both directions of mass transfer. This study has examined the mass transfer coefficients which has incorporated the effects of back‐mixing in the continuous phase. The effect of operating variables including pulsation intensity and dispersed and continuous phase velocities on volumetric overall mass transfer coefficient has been investigated. The experiments showed that mixer‐settler, transition and emulsion regimes exist in the column depending on the pulse characteristics. In the present work, effective diffusivity is substituted for molecular diffusivity in the Gröber equation for estimation of overall mass transfer coefficients. The enhancement factor is determined experimentally and there from a single empirical correlation is derived for prediction of enhancement factor in terms of Reynolds number, holdup and Eötvös number for all operating regimes and each mass transfer direction. The experimental results are in very good agreement with the values calculated by the proposed equation. © 2011 Canadian Society for Chemical Engineering     

Isolation and Identification of Current Biosurfactant-Producing Microbacterium maritypicum ABR5 as a Candidate for Oily Sludge Recovery

Biosurfactants have a wide range of applications in different areas, including petroleum microbiology and environmental biotechnology. In this study, removing and recovering oil from oily sludge using microbactan-producing bacteria have been investigated. The best biosurfactant-producing isolate was obtained from a petroleum reservoir and was identified by 16S rDNA analysis as Microbacterium maritypicum ABR5. Its 16S rDNA sequence was deposited in GenBank, NCBI under the accession number MK100468. Chemical analysis using thin-layer chromatography and Fourier Transform Infrared confirmed that the produced biosurfactant was glycolipoprotein. The strain reduced surface tension from 72 to 34.6 mN m⁻¹. The addition of 5 mg L ZnO nanoparticles to the biosurfactant-producing medium showed no bacterial toxicity effect and raised the emulsification index to 25.7%. Higher concentrations of ZnO nanoparticles, such as 10 and 100 mg L, decreased the bacterial growth rate and biosurfactant production. The mixing of M. maritypicum ABR5 culture medium and oily sludge increased the oil recovery from oily sludge by up to 70% after 5 days of incubation. This is the first report of biosurfactant production by a newly identified strain, M. maritypicum ABR5, isolated from a petroleum reservoir. We proposed that the isolated biosurfactant-producing strain could be considered an economical asset for oil recovery from oily sludge in the petroleum industry and environmental biotechnology.     

Multi-objective exergy-based optimization of a continuous photobioreactor applied to produce hydrogen using a novel combination of soft computing techniques

This work was aimed at proposing a flexible and reliable framework based on combination of three soft computing techniques, i.e., artificial neural network, genetic algorithm, and fuzzy systems for multi-objective exergetic optimization of continuous photobiohydrogen production process from syngas by Rhodospirillum rubrum bacterium. To this end, artificial neural network (ANN) coupled with fuzzy clustering method (FCM) to model exergetic outputs on the basis of input variables. The outputs of modeling system were then fed into a novel optimization approach developed by hybridizing additive linear interdependent fuzzy multi-objective optimization (ALIFMO) and the elitist non-dominated sorting genetic algorithm (NSGA-II). The optimization was carried out to minimize the normalized exergy destruction and maximize the rational and process exergetic efficiencies, simultaneously. The solutions of the proposed approach were also compared with conventional fuzzy multi-objective optimization procedure with independent objectives. Overall, the modeling system predicted the exergetic parameters of photobioreactor with a coefficient of determination higher than 0.90. Furthermore, the optimization approach suggested syngas flow rate of 13.35 mL/min and agitation speed of 383.34 rpm as the best operational condition by considering the preferences of process exergy efficiency, rational exergy efficiency, and normalized exergy destruction, respectively. This condition could yield the normalized exergy destruction of 1.56, process exergetic efficiency of 21.66%, and rational exergetic efficiency of 85.65%. The obtained results showed the superiority of the proposed approach over the conventional fuzzy method in optimizing the complex biofuel production systems.     

Application of eddy current nondestructive method for determination of surface carbon content in carburized steels

Apart from traditional application of nondestructive eddy current technique for detection of discontinuities, the method has been recently used to determine physical and metallurgical properties of steel parts. In the present research the application of eddy current method for determination of surface carbon of steel parts in gas carburizing process has been studied. The relation between the surface carbon content and various parameters such as impedance, phase angle and voltage has been established. Besides the effect of carbon content of the impedance plain has been investigated. The study shows that the best relation (R²=0.91) can be achieved using phase angle.     

Growth response of human coronary smooth muscle cells to angiotensin II and influence of angiotensin AT1 receptor blockade

BACKGROUND: Adolescents and young adults are four times more likely to be victims of sexual assault than women in all other age groups. In the vast majority of these cases, the perpetrator is an acquaintance of the victim. Date rape is a subset of acquaintance rape where nonconsensual sex occurs between two people who are in a romantic relationship. METHODS: We conducted a MEDLINE and Current Concepts search for articles relating to date rape and then systematically reviewed all relevant articles. RESULTS: Lifetime prevalence of date or acquaintance rape ranges from 13% to 27% among college-age women and 20% to a high of 68% among adolescents. Demographic characteristics that increase vulnerability to date rape include younger age at first date, early sexual activity, earlier age of menarche, a past history of sexual abuse or prior sexual victimization, and being more accepting of rape myths and violence toward women. Other risk factors include date-specific behaviors such as who initiated, who paid expenses, who drove, date location and activity, as well as the use of alcohol or illicit drugs such as flunitrazepam (Rohypnol). Alcohol use that occurs within the context of the date can lead to: the misinterpretation of friendly cues as sexual invitations, diminished coping responses, and the female's inability to ward off a potential attack. CONCLUSIONS: Longitudinal research designs are needed to further our understanding of sexual violence among adolescents and young adults and the most effective ways to eliminate it. Understanding and comparing research findings would be easier if consensus regarding the definitions of date rape, sexual aggression, and sexual assault was obtained. Finally, primary and secondary date and acquaintance rape prevention programs must be developed and systematically evaluated.     

Experimental study of AlGaAs/GaAs HBT device design for powerapplications

An experimental study of AlGaAs/GaAs heterojunction bipolar transistor (HBT) device design for optimizing key DC and RF performance parameters relevant to power device applications is reported. The design of the collector, base, and base-emitter junction is investigated for improved power device performance, and novel device structures are presented. Device scaling effects and the extent to which air-bridged interconnect can reduce parasitics in large power devices are also explored. Power HBTs employing some of the optimized design features have achieved a power output of 1.2 W (4 W/mm) with 43% power-added efficiency at 10 GHz     

Innovative piled raft foundations design using artificial neural network

Studying the piled raft behavior has been the subject of many types of research in the field of geotechnical engineering. Several studies have been conducted to understand the behavior of these types of foundations, which are often used for uniform loading on the raft and piles with the same length, while generally the transition load from the upper structure to the foundation is non-uniform and the choice of uniform length for piles in the above model will not be optimally economic and practical. The most common method in identifying the behavior of piled rafts is the use of theoretical relationships and software analyses. More precise identification of this type of foundation behavior can be very difficult due to several influential parameters and interaction of set behavior, and it will be done by doing time-consuming computer analyses or costly full-scale physical modeling. In the meantime, the technique of artificial neural networks can be used to achieve this goal with minimum time consumption, in which data from physical and numerical modeling can be used for network learning. One of the advantages of this method is the speed and simplicity of using it. In this paper, a model is presented based on multi-layer perceptron artificial neural network. In this model pile diameter, pile length, and pile spacing is considered as an input parameter that can be used to estimate maximum settlement, maximum differential settlement, and maximum raft moment. By this model, we can create an extensive domain of results for optimum system selection in the desired piled raft foundation. Results of neural network indicate its proper ability in identifying the piled raft behavior. The presented procedure provides an interesting solution and economically enhancing the design of the piled raft foundation system. This innovative design method reduces the time spent on software analyses.     

Interpretation of small and intermediate strain characteristics of Hostun sand for various stress states

Small and intermediate strain properties of soils are key parameters to assess ground motion characteristics during an earthquake and other dynamic events. These properties are affected by various parameters. Among them, the effect of anisotropic stress state on the soil specimen is interest of investigation in this paper. Experiments were carried out using the modified resonant column device at Ruhr Universität Bochum on dry Hostun sand with relative density of 35%-95%. The results show the significant effect of density and anisotropic stress states on the small strain properties, G_max, of Hostun sand. At intermediate strain level, the results show the significant effect of anisotropic stress state on the shear stiffness and damping ratio. In addition, it is concluded that the effect of compression stress component on the small and intermediate strain properties is more significant than the effect of the deviatoric stress component. At the end, the paper shows the successful application of stress-based approach to describe G(γ) and η(γ) in Hostun sand subjected to the isotropic and anisotropic stress states.     

Generation of high-average-power ultrabroad-band infrared pulses

This paper summarizes the results of analytical and numerical studies on a novel technique that is capable of providing high average power ultra broadband radiation that extends from approximately 2 to 16 μm. Such a spectrum has several potential applications, including telecommunications and remote sensing. Additional attractive features of the new source are its anticipated compact size, light weight, ruggedness, and affordable cost. The technique is based on the interaction of a beat wave with a nonlinear medium. The beat wave is formed from the mixing of two CO₂ laser beams with closely spaced wavelengths, such as 9.5 and 9.6 μm. The discrete ultrabroad-band spectrum is generated in a nonlinear optical medium by the self-phase modulation process, a third-order nonlinearity. The long-wavelength portion of the spectrum, i.e., from 5 to 16 μm is produced directly from the interaction of the beat wave with a GaAs crystal. The short-wavelength portion of the spectrum is produced from the interaction of a frequency-doubled beat wave with a GaAs crystal following the chirping of the pulse by a different GaAs crystal and its subsequent optimal compression by a thin sapphire slab