Search results for: particle-in cell simulation
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 8300

Search results for: particle-in cell simulation

3710 Drift-Wave Turbulence in a Tokamak Edge Plasma

Authors: S. Belgherras Bekkouche, T. Benouaz, S. M. A. Bekkouche

Abstract:

Tokamak plasma is far from having a stable background. The study of turbulent transport is an important part of the current research and advanced scenarios were devised to minimize it. To do this, we used a three-wave interaction model which allows to investigate the occurrence drift-wave turbulence driven by pressure gradients in the edge plasma of a tokamak. In order to simulate the energy redistribution among different modes, the growth/decay rates for the three waves was added. After a numerical simulation, we can determine certain aspects of the temporal dynamics exhibited by the model. Indeed for a wide range of the wave decay rate, an intermittent transition from periodic behavior to chaos is observed. Then, a control strategy of chaos was introduced with the aim of reducing or eliminating the weak turbulence.

Keywords: wave interaction, plasma drift waves, wave turbulence, tokamak, edge plasma, chaos

Procedia PDF Downloads 544
3709 Numerical and Experimental Investigation of Air Distribution System of Larder Type Refrigerator

Authors: Funda Erdem Şahnali, Ş. Özgür Atayılmaz, Tolga N. Aynur

Abstract:

Almost all of the domestic refrigerators operate on the principle of the vapor compression refrigeration cycle and removal of heat from the refrigerator cabinets is done via one of the two methods: natural convection or forced convection. In this study, airflow and temperature distributions inside a 375L no-frost type larder cabinet, in which cooling is provided by forced convection, are evaluated both experimentally and numerically. Airflow rate, compressor capacity and temperature distribution in the cooling chamber are known to be some of the most important factors that affect the cooling performance and energy consumption of a refrigerator. The objective of this study is to evaluate the original temperature distribution in the larder cabinet, and investigate for better temperature distribution solutions throughout the refrigerator domain via system optimizations that could provide uniform temperature distribution. The flow visualization and airflow velocity measurements inside the original refrigerator are performed via Stereoscopic Particle Image Velocimetry (SPIV). In addition, airflow and temperature distributions are investigated numerically with Ansys Fluent. In order to study the heat transfer inside the aforementioned refrigerator, forced convection theories covering the following cases are applied: closed rectangular cavity representing heat transfer inside the refrigerating compartment. The cavity volume has been represented with finite volume elements and is solved computationally with appropriate momentum and energy equations (Navier-Stokes equations). The 3D model is analyzed as transient, with k-ε turbulence model and SIMPLE pressure-velocity coupling for turbulent flow situation. The results obtained with the 3D numerical simulations are in quite good agreement with the experimental airflow measurements using the SPIV technique. After Computational Fluid Dynamics (CFD) analysis of the baseline case, the effects of three parameters: compressor capacity, fan rotational speed and type of shelf (glass or wire) are studied on the energy consumption; pull down time, temperature distributions in the cabinet. For each case, energy consumption based on experimental results is calculated. After the analysis, the main effective parameters for temperature distribution inside a cabin and energy consumption based on CFD simulation are determined and simulation results are supplied for Design of Experiments (DOE) as input data for optimization. The best configuration with minimum energy consumption that provides minimum temperature difference between the shelves inside the cabinet is determined.

Keywords: air distribution, CFD, DOE, energy consumption, experimental, larder cabinet, refrigeration, uniform temperature

Procedia PDF Downloads 91
3708 Analytical Approximations of the Differential Elastic Scattering Cross-Sections for Slow Electrons and Positrons Transport in Solids: A Comparative Study

Authors: A. Bentabet, A. Aydin, N. Fenineche

Abstract:

In this work, we try to determine the best analytical approximation of differential cross sections, used generally in Monte Carlo simulation, to study the electron/positron slowing down in solid targets in the energy range up to 10 keV. Actually, our comparative study was carried out on the angular distribution of the scattering angle, the elastic total and the first transport cross sections which are the essential quantities used generally in the electron/positron transport study by using both stochastic and deterministic methods. Indeed, the obtained results using the relativistic partial wave expansion method and the backscattering coefficient experimental data are used as criteria to evaluate the used model.

Keywords: differential cross-section, backscattering coefficient, Rutherford cross-section, Vicanek and Urbassek theory

Procedia PDF Downloads 554
3707 Acrylamide-Induced Acute Nephrotoxicity in Rats

Authors: Keivan Jamshidi, Afshin Zahedi

Abstract:

Acrylamide (ACR) has been shown to cause neurotoxic effects in humans and neurotoxic, genotoxic, reproductive, and carcinogenic effects in laboratory animals. To investigate the nephrotoxic effect of Acrylamide (ACR), 50 adult male rats (Wistar, approximately 250 g) housed in polycarbonate boxes as 5 per each, and randomly assigned in 5 groups including 4 exposure groups as A, B, C, and D groups of rats (10 rats per exposure group., total) and were exposed to 0.5, 5, 50, 100 mg/kg ACR per day×11days i.p. respectively. The remaining 10 rats were housed in group (E) as control group. Control rats received daily i.p. injections of 0.9% saline (3ml/kg). On day 12, four rats, were randomly selected, perfused , dissected and proper samples were collected from their kidneys. Results of histopathological studies based on H&E technique did show no morphologic changes in kidneys of rats belong to groups A, B and E, while moderate to severe morphologic changes including glomerular hypercellularity, global pattern of proliferative glomerulonephritis, occupation of capsular space, tubular cell swelling and hyaline cast formation, were observed in different stained sections obtained from the kidneys of rats belong to group, C, and D. This finding, beside neurotoxic, reproductive and carcinogenic effects, seems to indicate for the first time another important aspect of toxic effect of ACR, i.e., acute nephrotoxicity.

Keywords: acrylamide, nephrotoxicity, glomerulonephritis, rats

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3706 Simulation and Study of the Effect of Paint Mineral Coating on Energy Saving

Authors: A. A. Azemati, H. Hosseini

Abstract:

By using an adequate paint in buildings, energy consumption can be decreased. In this research, a range of wall paints in different climatic conditions has been investigated to observe its effect on energy consumption. In the current study, the researchers have investigated the effect of different parameters including climatic condition, absorption coefficient, and thermal loads on paint coating. In order to study these effects, heating and cooling loads of a typical building with different color paints have been calculated. The effect of building paint in different climatic condition was studied and a comparison was drawn between paints and painting coats with inorganic micro particles in temperate climate to obtain optimized energy consumption.

Keywords: climate, energy consumption, inorganic, painting coats

Procedia PDF Downloads 280
3705 Impact of Mass Customization for 3D Geographic Information Systems under Turbulent Environments

Authors: Abdo Shabah

Abstract:

Mass customization aims to produce customized goods (allowing economies of scope) at lower cost (to achieve economies of scale) using multiple strategies (modularization and postponement). Through a simulation experiment of organizations under turbulent environment, we aim to compare standardization and mass customization of services and assess the impact of different forms of mass customization (early and late postponement) on performance, quality and consumer satisfaction, on the use of modular dynamic 3D Geographic Information System. Our hypothesis is that mass customization performs better and achieves better quality in turbulent environment than standardization, but only when using early postponement strategies. Using mixed methods study, we try to confirm our hypothesis.

Keywords: mass customization, postponement, experiment, performance, quality, satisfaction, 3D GIS

Procedia PDF Downloads 444
3704 Proposing an Architecture for Drug Response Prediction by Integrating Multiomics Data and Utilizing Graph Transformers

Authors: Nishank Raisinghani

Abstract:

Efficiently predicting drug response remains a challenge in the realm of drug discovery. To address this issue, we propose four model architectures that combine graphical representation with varying positions of multiheaded self-attention mechanisms. By leveraging two types of multi-omics data, transcriptomics and genomics, we create a comprehensive representation of target cells and enable drug response prediction in precision medicine. A majority of our architectures utilize multiple transformer models, one with a graph attention mechanism and the other with a multiheaded self-attention mechanism, to generate latent representations of both drug and omics data, respectively. Our model architectures apply an attention mechanism to both drug and multiomics data, with the goal of procuring more comprehensive latent representations. The latent representations are then concatenated and input into a fully connected network to predict the IC-50 score, a measure of cell drug response. We experiment with all four of these architectures and extract results from all of them. Our study greatly contributes to the future of drug discovery and precision medicine by looking to optimize the time and accuracy of drug response prediction.

Keywords: drug discovery, transformers, graph neural networks, multiomics

Procedia PDF Downloads 133
3703 A Hybrid Method for Determination of Effective Poles Using Clustering Dominant Pole Algorithm

Authors: Anuj Abraham, N. Pappa, Daniel Honc, Rahul Sharma

Abstract:

In this paper, an analysis of some model order reduction techniques is presented. A new hybrid algorithm for model order reduction of linear time invariant systems is compared with the conventional techniques namely Balanced Truncation, Hankel Norm reduction and Dominant Pole Algorithm (DPA). The proposed hybrid algorithm is known as Clustering Dominant Pole Algorithm (CDPA) is able to compute the full set of dominant poles and its cluster center efficiently. The dominant poles of a transfer function are specific eigenvalues of the state space matrix of the corresponding dynamical system. The effectiveness of this novel technique is shown through the simulation results.

Keywords: balanced truncation, clustering, dominant pole, Hankel norm, model reduction

Procedia PDF Downloads 591
3702 Optimization Principles of Eddy Current Separator for Mixtures with Different Particle Sizes

Authors: Cao Bin, Yuan Yi, Wang Qiang, Amor Abdelkader, Ali Reza Kamali, Diogo Montalvão

Abstract:

The study of the electrodynamic behavior of non-ferrous particles in time-varying magnetic fields is a promising area of research with wide applications, including recycling of non-ferrous metals, mechanical transmission, and space debris. The key technology for recovering non-ferrous metals is eddy current separation (ECS), which utilizes the eddy current force and torque to separate non-ferrous metals. ECS has several advantages, such as low energy consumption, large processing capacity, and no secondary pollution, making it suitable for processing various mixtures like electronic scrap, auto shredder residue, aluminum scrap, and incineration bottom ash. Improving the separation efficiency of mixtures with different particle sizes in ECS can create significant social and economic benefits. Our previous study investigated the influence of particle size on separation efficiency by combining numerical simulations and separation experiments. Pearson correlation analysis found a strong correlation between the eddy current force in simulations and the repulsion distance in experiments, which confirmed the effectiveness of our simulation model. The interaction effects between particle size and material type, rotational speed, and magnetic pole arrangement were examined. It offer valuable insights for the design and optimization of eddy current separators. The underlying mechanism behind the effect of particle size on separation efficiency was discovered by analyzing eddy current and field gradient. The results showed that the magnitude and distribution heterogeneity of eddy current and magnetic field gradient increased with particle size in eddy current separation. Based on this, we further found that increasing the curvature of magnetic field lines within particles could also increase the eddy current force, providing a optimized method to improving the separation efficiency of fine particles. By combining the results of the studies, a more systematic and comprehensive set of optimization guidelines can be proposed for mixtures with different particle size ranges. The separation efficiency of fine particles could be improved by increasing the rotational speed, curvature of magnetic field lines, and electrical conductivity/density of materials, as well as utilizing the eddy current torque. When designing an ECS, the particle size range of the target mixture should be investigated in advance, and the suitable parameters for separating the mixture can be fixed accordingly. In summary, these results can guide the design and optimization of ECS, and also expand the application areas for ECS.

Keywords: eddy current separation, particle size, numerical simulation, metal recovery

Procedia PDF Downloads 78
3701 Development and Characterization of Bio-Tribological, Nano- Multilayer Coatings for Medical Tools Application

Authors: L. Major, J. M. Lackner, M. Dyner, B. Major

Abstract:

Development of new generation bio- tribological, multilayer coatings, opens an avenue for fabrication of future high- tech functional surfaces. In the presented work, nano- composite, Cr/CrN+[Cr/ a-C:H implanted by metallic nanocrystals] multilayer coatings have been developed for surface protection of medical tools. Thin films were fabricated by a hybrid Pulsed Laser Deposition technique. Complex microstructure analysis of nano- multilayer coatings, subjected to mechanical and biological tests, were performed by means of transmission electron microscopy (TEM). Microstructure characterization revealed the layered arrangement of Cr23C6 nanoparticles in multilayer structure. Influence of deposition conditions on bio- tribological properties of the coatings were studied. The bio-tests were used as a screening tool for the analyzed nano- multilayer coatings before they could be deposited on medical tools. Bio- medical tests were done using fibroblasts. The mechanical properties of the coatings were investigated by means of a ball-on-disc mechanical test. The microhardness was done using Berkovich indenter. The scratch adhesion test was done using Rockwell indenter. From the bio- tribological point of view, the optimal properties had the C106_1 material.

Keywords: bio- tribological coatings, cell- material interaction, hybrid PLD, tribology

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3700 Across-Breed Genetic Evaluation of New Zealand Dairy Goats

Authors: Nicolas Lopez-Villalobos, Dorian J. Garrick, Hugh T. Blair

Abstract:

Many dairy goat farmers of New Zealand milk herds of mixed breed does. Simultaneous evaluation of sires and does across breed is required to select the best animals for breeding on a common basis. Across-breed estimated breeding values (EBV) and estimated producing values for 208-day lactation yields of milk (MY), fat (FY), protein (PY) and somatic cell score (SCS; LOG2(SCC) of Saanen, Nubian, Alpine, Toggenburg and crossbred dairy goats from 75 herds were estimated using a test day model. Evaluations were based on 248,734 herd-test records representing 125,374 lactations from 65,514 does sired by 930 sires over 9 generations. Averages of MY, FY and PY were 642 kg, 21.6 kg and 19.8 kg, respectively. Average SCC and SCS were 936,518 cells/ml milk and 9.12. Pure-bred Saanen does out-produced other breeds in MY, FY and PY. Average EBV for MY, FY and PY compared to a Saanen base were Nubian -98 kg, 0.1 kg and -1.2 kg; Alpine -64 kg, -1.0 kg and -1.7 kg; and Toggenburg -42 kg, -1.0 kg and -0.5 kg. First-cross heterosis estimates were 29 kg MY, 1.1 kg FY and 1.2 kg PY. Average EBV for SCS compared to a Saanen base were Nubian 0.041, Alpine -0.083 and Toggenburg 0.094. Heterosis for SCS was 0.03. Breeding values are combined with respective economic values to calculate an economic index used for ranking sires and does to reflect farm profit.

Keywords: breed effects, dairy goats, milk traits, test-day model

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3699 Analysis of Roll-Forming for High-Density Wire of Reed

Authors: Yujeong Shin, Seong Jin Cho, Jin Ho Kim

Abstract:

In the textile-weaving machine, the reed is the core component to separate thousands of strands of yarn and to produce the fabric in a continuous high-speed movement. In addition, the reed affects the quality of the fiber. Therefore, the wire forming analysis of the main raw materials of the reed needs to be considered. Roll-forming is a key technology among the manufacturing process of reed wire using textile machine. A simulation of roll-forming line in accordance with the reduction rate is performed using LS-DYNA. The upper roller, fixed roller and reed wire are modeled by finite element. The roller is set to be rigid body and the wire of SUS430 is set to be flexible body. We predict the variation of the cross-sectional shape of the wire depending on the reduction ratio.

Keywords: textile machine, reed, rolling, reduction ratio, wire

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3698 Modeling of Nanocomposite Films Made of Cloisite 30b- Metal Nanoparticle in Packaging of Soy Burger

Authors: Faranak Beigmohammadi, Seyed Hadi Peighambardoust, Seyed Jamaledin Peighambardoust

Abstract:

This study undertakes to investigate the ability of different kinds of nanocomposite films made of cloisite-30B with different percentages of silver and copper oxide nanoparticles incorporated into a low-density polyethylene (LDPE) polymeric matrix by a melt mixing method in order to inhibit the growth of microorganism in soy burger. The number of surviving cell of the total count was decreased by 3.61 log and mold and yeast diminished by 2.01 log after 8 weeks storage at 18 ± 0.5°C below zero, whilst pure LDPE did not has any antimicrobial effect. A composition of 1.3 % cloisite 30B-Ag and 2.7 % cloisite 30B-CuO for total count and 0 % cloisite 30B-Ag and 4 % cloisite 30B-CuO for yeast & mold gave optimum points in combined design test in Design Expert 7.1.5. Suitable microbial models were suggested for retarding above microorganisms growth in soy burger. To validation of optimum point, the difference between the optimum point of nanocomposite film and its repeat was not significant (p<0.05) by one-way ANOVA analysis using SPSS 17.0 software, while the difference was significant for pure film. Migration of metallic nanoparticles into a food stimulant was within the accepted safe level.

Keywords: modeling, nanocomposite film, packaging, soy burger

Procedia PDF Downloads 286
3697 Non-Linear Control Based on State Estimation for the Convoy of Autonomous Vehicles

Authors: M-M. Mohamed Ahmed, Nacer K. M’Sirdi, Aziz Naamane

Abstract:

In this paper, a longitudinal and lateral control approach based on a nonlinear observer is proposed for a convoy of autonomous vehicles to follow a desired trajectory. To authors best knowledge, this topic has not yet been sufficiently addressed in the literature for the control of multi vehicles. The modeling of the convoy of the vehicles is revisited using a robotic method for simulation purposes and control design. With these models, a sliding mode observer is proposed to estimate the states of each vehicle in the convoy from the available sensors, then a sliding mode control based on this observer is used to control the longitudinal and lateral movement. The validation and performance evaluation are done using the well-known driving simulator Scanner-Studio. The results are presented for different maneuvers of 5 vehicles.

Keywords: autonomous vehicles, convoy, non-linear control, non-linear observer, sliding mode

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3696 Development and Evaluation of Novel Diagnostic Methods for Infectious Rhinotracheitis of Cattle

Authors: Wenxiao Liu, Kun Zhang, Yongqing Li

Abstract:

Bovine herpesvirus 1, a member of the genus Variellovirus of the subfamily Alphaherpesvirinae, has caused severe economic cost to the bovine industry. In this study, BoHV-1 glycerol protein gD was expressed in insect cells, and the purified gD was immunized in the Balb/C mice to generate monoclonal antibodies. Based on hybridoma cell fusion techniques, 20 monoclonal antibodies against Bovine herpesvirus 1 have been obtained. Further, mAb 3F8 with neutralizing activity and gD were applied to develop a blocking enzyme-linked immunosorbent assay (Elisa) for detecting neutralizing antibodies against BoHV-1, which shows a significant correlation between the blocking Elisa and VNT. The sensitivity and specificity of the test were estimated to be 94.59% and 93.42%, respectively. Furthermore, antibody pairing tests revealed that mAb 1B6 conjugated to fluorescence microspheres was used as the capture antibody, and mAb 3F9 was used as the detectable antibody to establish the immunochromatographic assay (ICS). The ICS was conducted to detect BoHV-1 in bovine samples with high sensitivity, specificity, and good stability. Clinical sample testing revealed that the results of ICS and real-time PCR have a coincidence rate of 95.42%. Our research confirmed that the ICS is a rapid and reliable method for the diagnosis of BoHV-1. In conclusion, our results lay a solid foundation for the prevention and control of BoHV-1 infection.

Keywords: bovine disease, BoHV-1, ELISA, ICS assay

Procedia PDF Downloads 60
3695 Effect of Gel Concentration on Physical Properties of an Electrochromic Device

Authors: Sharan K. Indrakar, Aakash B. Prasad, Arash Takshi, Sesha Srinivasan, Elias K. Stefanakos

Abstract:

In this work, we present an exclusive study on the effect of the feeding ratio of polyaniline-based redox-active gel layer on electrical and optical properties of innovative electrochromic devices (ECs). An electrochromic device consisting of polyaniline (PANI) has a redox-active gel electrolyte placed between two conducting transparent fluorine-doped tin oxide glass substrates. The redox-active composite gel is a mixture of different concentrations of aniline (monomer), a water-soluble polymer poly (vinyl alcohol), hydrochloric acid, and an oxidant. The EC device shows the color change from dark green to transparent for the applied potential between -0.5 V to +2.0 V. The coloration and decoloration of the ECs were tested for electrochemical behavior using techniques such as cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). The optical transparency of the EC devices was examined at two different biasing voltage conditions under UV-visible spectroscopic technique; the result showed 65% transmittance at 564 nm and zero transmittance when the cell was biased at 0.0 V and 2.0 V, the synthesized mol fraction gel was analyzed for surface morphology and structural properties by scanning electron microscopy and Fourier transformer spectroscopy.

Keywords: electrochromic, gel electrolyte, polyaniline, conducting polymer

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3694 Synthesis of Biostabilized Gold Nanoparticles Using Garcinia indica Extract and Its Antimicrobial and Anticancer Properties

Authors: Rebecca Thombre, Aishwarya Borate

Abstract:

Chemical synthesis of nanoparticles produces toxic by-products, as a result of which eco-friendly methods of synthesis are gaining importance. The synthesis of nanoparticles using plant derived extracts is economical, safe and eco-friendly. Biostabilized gold nanoparticles were synthesized using extracts of Garcinia indica. The gold nanoparticles were characterized using UV-Vis spectrophotometry and demonstrated a peak at 527 nm. The presence of plant derived peptides and phytoconstituents was confirmed using the FTIR spectra. TEM analysis revealed formation of gold nanopyramids and nanorods. The SAED analysis confirmed the crystalline nature of nanoparticles. The gold nanoparticles demonstrated antibacterial and antifungal activity against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Aspergillus niger and Pichia pastoris. The cytotoxic activity of gold nanoparticles was studied using HEK, Hela and L929 cancerous cell lines and the apoptosis of cancerous cells were observed using propidium iodide staining. Thus, a simple and eco-friendly method for synthesis of biostabilized gold nanoparticles using fruit extracts of Garcinia indica was developed and the nanoparticles had potent antibacterial, antifungal and anticancer properties.

Keywords: cytotoxic, gold nanoparticles, green synthesis, Garcinia indica, anticancer

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3693 Design and Performance Optimization of Isostatic Pressing Working Cylinder Automatic Exhaust Valve

Authors: Wei-Zhao, Yannian-Bao, Xing-Fan, Lei-Cao

Abstract:

An isostatic pressing working cylinder automatic exhaust valve is designed. The finite element models of valve core and valve body under ultra-high pressure work environment are built to study the influence of interact of valve core and valve body to sealing performance. The contact stresses of metal sealing surface with different sizes are calculated and the automatic exhaust valve is optimized. The result of simulation and experiment shows that the sealing of optimized exhaust valve is more reliable and the service life is greatly improved. The optimized exhaust valve has been used in the warm isostatic pressing equipment.

Keywords: exhaust valve, sealing, ultra-high pressure, isostatic pressing

Procedia PDF Downloads 294
3692 Solid Particles Transport and Deposition Prediction in a Turbulent Impinging Jet Using the Lattice Boltzmann Method and a Probabilistic Model on GPU

Authors: Ali Abdul Kadhim, Fue Lien

Abstract:

Solid particle distribution on an impingement surface has been simulated utilizing a graphical processing unit (GPU). In-house computational fluid dynamics (CFD) code has been developed to investigate a 3D turbulent impinging jet using the lattice Boltzmann method (LBM) in conjunction with large eddy simulation (LES) and the multiple relaxation time (MRT) models. This paper proposed an improvement in the LBM-cellular automata (LBM-CA) probabilistic method. In the current model, the fluid flow utilizes the D3Q19 lattice, while the particle model employs the D3Q27 lattice. The particle numbers are defined at the same regular LBM nodes, and transport of particles from one node to its neighboring nodes are determined in accordance with the particle bulk density and velocity by considering all the external forces. The previous models distribute particles at each time step without considering the local velocity and the number of particles at each node. The present model overcomes the deficiencies of the previous LBM-CA models and, therefore, can better capture the dynamic interaction between particles and the surrounding turbulent flow field. Despite the increasing popularity of LBM-MRT-CA model in simulating complex multiphase fluid flows, this approach is still expensive in term of memory size and computational time required to perform 3D simulations. To improve the throughput of each simulation, a single GeForce GTX TITAN X GPU is used in the present work. The CUDA parallel programming platform and the CuRAND library are utilized to form an efficient LBM-CA algorithm. The methodology was first validated against a benchmark test case involving particle deposition on a square cylinder confined in a duct. The flow was unsteady and laminar at Re=200 (Re is the Reynolds number), and simulations were conducted for different Stokes numbers. The present LBM solutions agree well with other results available in the open literature. The GPU code was then used to simulate the particle transport and deposition in a turbulent impinging jet at Re=10,000. The simulations were conducted for L/D=2,4 and 6, where L is the nozzle-to-surface distance and D is the jet diameter. The effect of changing the Stokes number on the particle deposition profile was studied at different L/D ratios. For comparative studies, another in-house serial CPU code was also developed, coupling LBM with the classical Lagrangian particle dispersion model. Agreement between results obtained with LBM-CA and LBM-Lagrangian models and the experimental data is generally good. The present GPU approach achieves a speedup ratio of about 350 against the serial code running on a single CPU.

Keywords: CUDA, GPU parallel programming, LES, lattice Boltzmann method, MRT, multi-phase flow, probabilistic model

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3691 Efficacy Enhancement of Hydrophobic Antibiotics Employing Rhamnolipid as Biosurfactant

Authors: Abdurrahim A. Elouzi, Abdurrauf M. Gusbi, Ali M. Elgerbi

Abstract:

Antibiotic resistance has become a global public-health problem, thus it is imperative that new antibiotics continue to be developed. Major problems are being experienced in human medicine from antibiotic resistant bacteria. Moreover, no new chemical class of antibiotics has been introduced into medicine in the past two decades. The aim of the current study presents experimental results that evaluate the capability of bio surfactant rhamnolipid on enhancing the efficacy of hydrophobic antibiotics. Serial dilutions of azithromycin and clarithromycin were prepared. A bacterial suspension (approximately 5 X 105 CFU) from an overnight culture in MSM was inoculated into 20 ml sterile test tube each containing a serial 10-fold dilution of the test antibiotic(s) in broth with or without 200 mgL-1 rhamnolipid. The tubes were incubated for 24 h with vigorous shaking at 37°C. Antimicrobial activity in multiple antibiotic-resistant gram-negative bacteria pathogens and gram-positive bacteria were assessed using optical density technique. The results clearly demonstrated that the presence of rhamnolipid significantly improved the efficiency of both antibiotics. We hypothesized that the addition of rhamnolipid at low concentration, causes release of LPS which results in an increase in cell surface hydrophobicity. This allows increased association of cells with hydrophobic antibiotics resulting in increased cytotoxicity rates.

Keywords: hydrophobic antibiotics, biosurfactant, rhamnolipid, azithromycin, clarithromycin

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3690 Metagenomics Features of The Gut Microbiota in Metabolic Syndrome

Authors: Anna D. Kotrova, Alexandr N. Shishkin, Elena I. Ermolenko

Abstract:

The aim. To study the quantitative and qualitative colon bacteria ratio from patients with metabolic syndrome. Materials and methods. Fecal samples from patients of 2 groups were identified and analyzed: the first group was formed by patients with metabolic syndrome, the second one - by healthy individuals. The metagenomics method was used with the analysis of 16S rRNA gene sequences. The libraries of the variable sites (V3 and V4) gene 16S RNA were analyzed using the MiSeq device (Illumina). To prepare the libraries was used the standard recommended by Illumina, a method based on two rounds of PCR. Results. At the phylum level in the microbiota of patients with metabolic syndrome compared to healthy individuals, the proportion of Tenericutes was reduced, the proportion of Actinobacteria was increased. At the genus level, in the group with metabolic syndrome, relative to the second group was increased the proportion of Lachnospira. Conclusion. Changes in the colon bacteria ratio in the gut microbiota of patients with metabolic syndrome were found both at the type and the genus level. In the metabolic syndrome group, there is a decrease in the proportion of bacteria that do not have a cell wall. To confirm the revealed microbiota features in patients with metabolic syndrome, further study with a larger number of samples is required.

Keywords: gut microbiota, metabolic syndrome, metagenomics, tenericutes

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3689 Synchronous Generator in Case Voltage Sags for Different Loads

Authors: Benalia Nadia, Bensiali Nadia, Zezouri Noura

Abstract:

This paper studies the effects of voltage sags, both symmetrical and unsymmetrical, on the three-phase Synchronous Machine (SM) when powering an isolate load or infinite bus bar. The vast majority of the electrical power generation systems in the world is consist of synchronous generators coupled to the electrical network though a transformer. Voltage sags on SM cause speed variations, current and torque peaks and hence may cause tripping and equipment damage. The consequences of voltage sags in the machine behavior depends on different factors such as its magnitude (or depth), duration , the parameters of the machine and also the size of load. In this study, we consider the machine feeds an infinite bus bar in the first and the isolate load using symmetric and asymmetric defaults to see the behavior of the machine in both case the simulation have been used on SIMULINK MATLAB.

Keywords: power quality, voltage sag, synchronous generator, infinite system

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3688 Mimicking of Various ECM Tangible Cues for the Manipulation of Hepatocellular Behaviours

Authors: S. A. Abdellatef, A. Taniguchi, Namiki, Tsukuba, Ibaraki

Abstract:

The alterations in the physicochemical characteristics of bio-materials are renowned for their impact in cellular behaviors. Surface chemistry and substratum topography are separately considered as mutable characteristics with deep impact on the overall cell behaviors. In our recent work, we examined the manipulation of the physical cues on hepatic cellular behaviors. We have proven that the geometrical or dimensional characteristics of nano features are essential for the optimum hepatocellular functions. While here, the collective impact of both physical and chemical cues on hepatocellular behaviors was investigated. On which RGD peptide was immobilized on a TiO2 nano pattern that imitates the hierarchically extend collagen nano fibrillar structures. The hepatocytes morphological and functional changes induced by simultaneously combining the diversified cues were investigated. TiO2 substrates that integrate nano topography with the adhesive peptide motif (RGD) had showed an increase in the hepatocellular functionality to the maximum extent. While a significant enhancement in expression of these liver specific markers on RGD coated surfaces were observed compared to uncoated substrates regardless of topography. Consequently in depth understanding of the relationship between various kind of cues and hepatocytes behaviors would be a paving step in the application of tissue engineering and bio reactor technology.

Keywords: biomaterial, tiO2, hepG2, RGD

Procedia PDF Downloads 387
3687 Fast Terminal Synergetic Converter Control

Authors: Z. Bouchama, N. Essounbouli, A. Hamzaoui, M. N. Harmas

Abstract:

A new robust finite time synergetic controller is presented based on recently developed synergetic control methodology and a terminal attractor technique. A Fast Terminal Synergetic Control (FTSC) is proposed for controlling DC-DC buck converter. Unlike Synergetic Control (SC) and sliding mode control, the proposed control scheme has the characteristics of finite time convergence and chattering free phenomena. Simulation of stabilization and reference tracking for buck converter systems illustrates the approach effectiveness while stability is assured in the Lyapunov sense and converse Lyapunov results involving scalar differential inequalities are given for finite-time stability.

Keywords: dc-dc buck converter, synergetic control, finite time convergence, terminal synergetic control, fast terminal synergetic control, Lyapunov

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3686 Decreased Autophagy Contributes to Senescence Induction in HS68 Cells

Authors: Byeal-I Han, Michael Lee

Abstract:

Ageing is associated with an increased risk of diseases such as cancer, and neurodegenerative disorders. Increased autophagy delays ageing and extends longevity. In this study, we investigated the role of autophagy in longevity using human foreskin fibroblast HS68 cells, in which a senescence-like growth arrest can be induced. In particular, cellular senescence is manifested by the irreversible cell cycle arrest, and may contribute to the ageing of organisms. The senescence state was measured with staining for senescence-associated β-galactosidase (SA-β-gal) activity that represents a sensitive and reliable marker to quantify senescent cells. We detected a significantly increased percentage (%) of SA-β-gal positive cells in HS68 cultures at passage 40 (63%) when compared with younger ones at passage 15 (0.5%). As expected, HS68 cells at passage 40 exhibited much lower proliferation rate than cells at passage 15. The basal levels of LC3 were measured by immunoblotting showing a comparison of LC3-I and LC3-II levels at 3 age-points in serially passaged HS68 cells. LC3-II/LC3-I ratio at different passage levels relative to β-actin levels of each band confirmed that cells at passage 34 showed lower conversion of non-autophagic LC3-I to autophagic LC3-II than the cells at passage 16. Furthermore, Cyto-ID autophagy assay also revealed that late passage cells showed lower autophagy than the early passage cells. Together, our findings suggest that senescence induction might be associated with decreased autophagy.

Keywords: ageing, autophagy, senescence, HS68

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3685 Optimization of Flexible Job Shop Scheduling Problem with Sequence-Dependent Setup Times Using Genetic Algorithm Approach

Authors: Sanjay Kumar Parjapati, Ajai Jain

Abstract:

This paper presents optimization of makespan for ‘n’ jobs and ‘m’ machines flexible job shop scheduling problem with sequence dependent setup time using genetic algorithm (GA) approach. A restart scheme has also been applied to prevent the premature convergence. Two case studies are taken into consideration. Results are obtained by considering crossover probability (pc = 0.85) and mutation probability (pm = 0.15). Five simulation runs for each case study are taken and minimum value among them is taken as optimal makespan. Results indicate that optimal makespan can be achieved with more than one sequence of jobs in a production order.

Keywords: flexible job shop, genetic algorithm, makespan, sequence dependent setup times

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3684 Computational Fluid Dynamics of a Bubbling Fluidized Bed in Wood Pellets

Authors: Opeyemi Fadipe, Seong Lee, Guangming Chen, Steve Efe

Abstract:

In comparison to conventional combustion technologies, fluidized bed combustion has several advantages, such as superior heat transfer characteristics due to homogeneous particle mixing, lower temperature needs, nearly isothermal process conditions, and the ability to operate continuously. Computational fluid dynamics (CFD) can help anticipate the intricate combustion process and the hydrodynamics of a fluidized bed thoroughly by using CFD techniques. Bubbling Fluidized bed was model using the Eulerian-Eulerian model, including the kinetic theory of the flow. The model was validated by comparing it with other simulation of the fluidized bed. The effects of operational gas velocity, volume fraction, and feed rate were also investigated numerically. A higher gas velocity and feed rate cause an increase in fluidization of the bed.

Keywords: fluidized bed, operational gas velocity, volume fraction, computational fluid dynamics

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3683 Simplified Analysis on Steel Frame Infill with FRP Composite Panel

Authors: HyunSu Seo, HoYoung Son, Sungjin Kim, WooYoung Jung

Abstract:

In order to understand the seismic behavior of steel frame structure with infill FRP composite panel, simple models for simulation on the steel frame with the panel systems were developed in this study. To achieve the simple design method of the steel framed structure with the damping panel system, 2-D finite element analysis with the springs and dashpots models was conducted in ABAQUS. Under various applied spring stiffness and dashpot coefficient, the expected hysteretic energy responses of the steel frame with damping panel systems we re investigated. Using the proposed simple design method which decides the stiffness and the damping, it is possible to decide the FRP and damping materials on a steel frame system.

Keywords: numerical analysis, FEM, infill, GFRP, damping

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3682 Effects of Pressure and Temperature on the Extraction of Benzyl Isothiocyanate by Supercritical Fluids from Tropaeolum majus L. Leaves

Authors: Espinoza S. Clara, Gamarra Q. Flor, Marianela F. Ramos Quispe S. Miguel, Flores R. Omar

Abstract:

Tropaeolum majus L. is a native plant to South and Central America, used since ancient times by our ancestors to combat different diseases. Glucotropaeolonin is one of its main components, which when hydrolyzed, forms benzyl isothiocyanate (BIT) that promotes cellular apoptosis (programmed cell death in cancer cells). Therefore, the present research aims to evaluate the effect of the pressure and temperature of BIT extraction by supercritical CO2 from Tropaeolum majus L. The extraction was carried out in a supercritical fluid extractor equipment Speed SFE BASIC Brand: Poly science, the leaves of Tropaeolum majus L. were ground for one hour and lyophilized until obtaining a humidity of 6%. The extraction with supercritical CO2 was carried out with pressures of 200 bar and 300 bar, temperatures of 50°C, 60°C and 70°C, obtained by the conjugation of these six treatments. BIT was identified by thin layer chromatography using 98% BIT as the standard, and as the mobile phase hexane: dichloromethane (4:2). Subsequently, BIT quantification was performed by high performance liquid chromatography (HPLC). The highest yield of oleoresin by supercritical CO2 extraction was obtained pressure 300 bar and temperature at 60°C; and the higher content of BIT at pressure 200 bar and 70°C for 30 minutes to obtain 113.615 ± 0.03 mg BIT/100 g dry matter was obtained.

Keywords: solvent extraction, Tropaeolum majus L., supercritical fluids, benzyl isothiocyanate

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3681 Integrated Power Saving for Multiple Relays and UEs in LTE-TDD

Authors: Chun-Chuan Yang, Jeng-Yueng Chen, Yi-Ting Mai, Chen-Ming Yang

Abstract:

In this paper, the design of integrated sleep scheduling for relay nodes and user equipments under a Donor eNB (DeNB) in the mode of Time Division Duplex (TDD) in LTE-A is presented. The idea of virtual time is proposed to deal with the discontinuous pattern of the available radio resource in TDD, and based on the estimation of the traffic load, three power saving schemes in the top-down strategy are presented. Associated mechanisms in each scheme including calculation of the virtual subframe capacity, the algorithm of integrated sleep scheduling, and the mapping mechanisms for the backhaul link and the access link are presented in the paper. Simulation study shows the advantage of the proposed schemes in energy saving over the standard DRX scheme.

Keywords: LTE-A, relay, TDD, power saving

Procedia PDF Downloads 503