Showing papers by "Congrès International d'Architecture Moderne published in 2014"

Usefulness of Multiparental Populations of Maize (Zea mays L.) for Genome-Based Prediction

Abstract: The efficiency of marker-assisted prediction of phenotypes has been studied intensively for different types of plant breeding populations. However, one remaining question is how to incorporate and counterbalance information from biparental and multiparental populations into model training for genome-wide prediction. To address this question, we evaluated testcross performance of 1652 doubled-haploid maize (Zea mays L.) lines that were genotyped with 56,110 single nucleotide polymorphism markers and phenotyped for five agronomic traits in four to six European environments. The lines are arranged in two diverse half-sib panels representing two major European heterotic germplasm pools. The data set contains 10 related biparental dent families and 11 related biparental flint families generated from crosses of maize lines important for European maize breeding. With this new data set we analyzed genome-based best linear unbiased prediction in different validation schemes and compositions of estimation and test sets. Further, we theoretically and empirically investigated marker linkage phases across multiparental populations. In general, predictive abilities similar to or higher than those within biparental families could be achieved by combining several half-sib families in the estimation set. For the majority of families, 375 half-sib lines in the estimation set were sufficient to reach the same predictive performance of biomass yield as an estimation set of 50 full-sib lines. In contrast, prediction across heterotic pools was not possible for most cases. Our findings are important for experimental design in genome-based prediction as they provide guidelines for the genetic structure and required sample size of data sets used for model training.

Neospora caninum infection during early pregnancy in cattle: how the isolate influences infection dynamics, clinical outcome and peripheral and local immune responses

Abstract: This work studies the influence of Neospora caninum intra-species diversity on abortion outcome, infection dynamics in terms of parasite dissemination and peripheral-local immune responses in pregnant cattle. Animals were intravenously inoculated at day 70 of pregnancy with 107 tachyzoites of two isolates showing marked differences in virulence in vitro and in pregnant mouse models: Nc-Spain7, a high virulence isolate, and Nc-Spain8, a low-to-moderate virulence isolate. After inoculation, pregnancy was monitored, and dams were culled when foetal death was detected. Foetal mortality occurred in all infected heifers between days 24 and 49 post-infection (pi), however, it was detected sooner in Nc-Spain7-infected animals (median day = 34) than those inoculated with Nc-Spain8 (median day = 41) with a trend towards significance (P < 0.11). Similar histological lesions were observed in placentomes and in most of the foetuses from the two infected groups. However, parasites were more frequently detected in the placenta and foetuses by PCR and in the foetal brain by immunohistochemistry in Nc-Spain7-infected animals. Specific antibodies were detected starting at day 13 post-infection in all infected cattle, with higher IgG levels in Nc-Spain7-infected group. IFN-γ and IL-4 profiles also varied between infected groups in PBMC stimulation assays. Infected animals showed significant increases in their cytokine mRNA levels (IFN-γ, IL-4, IL-10, IL-12p40 and TNF-α) in the caruncle at time of foetal death. Differences between the infected groups were also observed for cytokine profiles. These results demonstrate the influence of the N. caninum isolate on foetal death outcome, infection dynamics and immune responses in cattle.

Cold tolerance in two large maize inbred panels adapted to European climates

Abstract: 34 pags., 5 tabl. The definitive version is available at: https://www.crops.org/publications/cs

Investigation of PAH and other hazardous contaminant occurrence in recycled tyre rubber surfaces. Case-study: restaurant playground in an indoor shopping centre

Abstract: The objective of this case study was to investigate the presence of polycyclic aromatic hydrocarbons (PAHs) and other hazardous organic chemicals in a recycled tyre playground surface (in an indoor restaurant of a shopping centre with limited ventilation). This study also aimed at underlining both the volatilisation of these compounds in the vapour phase above the sample and the partial leaching of contaminants from the playground surface to the runoff and cleaning water put in contact with the sample. Playground samples were extracted with ethyl acetate using ultrasonic energy followed by GC-MS analysis. In addition, the same samples were analysed by HS-SPME to study the volatilisation and the transfer of those organic compounds. The analysis confirmed the presence of a large number of hazardous substances. Thus, 14 of the 16 studied PAHs were identified in the extracts (including the considered most toxic PAH, benzo[a]pyrene) and nine of them were also detected in the vapour phase. Besides, nine PAHs we...

Hot isostatic pressing of single-crystal nickel-base superalloys: Mechanism of pore closure and effect on Mechanical properties

Abstract: Pore annihilation was investigated in the single-crystal nickel-base superalloy CMSX-4. HIP tests at 1288 °C/103 MPa were interrupted at different times, then the specimens were investigated by TEM, metallography and density measurements. The kinetics of pore annihilation was determined. The pore closure mechanism was identified as plastic deformation on the octahedral slip systems. A model describing the kinetics of pore closure has been developed on the base of crystal plasticity and large strain theory. Mechanical tests with the superalloy CMSX-4 and the Ru-containing superalloy VGM4 showed, that HIP significantly increases the fatigue life at low temperatures but has no effect on creep strength.

Numerical evaluation of conformal mapping and its inverse for unbounded multiply connected regions

Abstract: A boundary integral equation method for numerical evaluation of the conformal mapping and its inverse from unbounded multiply connected regions onto five canonical slit regions is presented in this paper. This method is based on a uniquely solvable boundary integral equation with the adjoint generalized Neumann kernel. This method is accurate and reliable. Some numerical examples are presented to illustrate the effectiveness of this method.

Analysis of different high production volume chemicals and their chlorination by-products in waters by ultrasound-assisted emulsification–microextraction

Abstract: Ultrasound-assisted emulsification–microextraction (USAEME) demonstrated its applicability for the analysis in waters of 2-phenylphenol (PP), 4-tert-butylphenol (TBP), benzothiazole (BTZ) and piperonyl butoxide (PBO), belonging to different chemical families, and all of them characterised by its high production volume. In the developed USAEME procedure, compounds were extracted in chloroform from 10 mL of water sample during only 5 min. The addition of derivatising reagents has been studied as part of the optimisation process. The optimised procedure provided an efficient and exhaustive extraction with the advantage that the extract was ready for GC analysis. The method was validated using real environmental water samples, obtaining recoveries between 68 and 111%, RSD values ≤10%, and limits of quantification at the sub-ng per millilitre level (0.004–0.072 μg L−1). The application of the method to the determination of the targets in different environmental waters showed their presence in most samples.In a...

Stall Margin Improvement in Three-Stage Low Pressure Compressor by Use of Slot Type Casing Treatments

Abstract: The Central Institute of Aviation Motors (CIAM) has been engaged in the development of methods and technologies extending the range of stable operation for GTE axial compressors on the basis of systematic experimental and theoretical investigations of processes before and after flow disturbances for many years. The general sources of experimental data were stage models of various types. They are first supersonic stages with 0.3–0.45 hub ratio and subsonic stages with 0.75 hub ratio, as well as high-loaded stages with low aspect ratio.As a result of these investigations, a structural configuration of the casing treatment (CT) was designed to prevent local flow separation on flow passage surfaces of a compressor stage.The CT structure includes the following components:- Slotted spacer installed above the inlet rotor section;- Attached ring covering the slotted spacer.An approximate procedure for selecting the optimal CT geometric parameters and their interrelations was developed for CT designing. Using this procedure, special investigations were completed and detected the CT effects on operation of the axial compressor.These effects are:- Effect of air back and forward leakage through slots between the blade tips and the inlet rotor section;- Effect of stall deceleration in the stage flow passage;- Pulsation damping at the stage tip when flowing around the CT slotted spacer.Based on this methodology, CT prototypes were developed and tested in various single-stage and multi-stage compressors. As an example of CT advantages, we can show test results for a three-stage low-pressure compressor (LPC) designed by CIAM.The LPC in take-off conditions provides the following design parameters:- Pressure ratio: 3.4;- Corrected tip speed: 418 m/s;- Stall margin: 20% … 21% within 0.5–1.0 corrected RPM.According to experimental investigations, the use of CT results in a considerable increase in LPC stall margin without losses in other design parameters. Additionally, the results of 3D viscous flow calculation are shown for compressor performance analysis.Copyright © 2014 by ASME

Mathematical modeling of flows in wind turbines with a vertical axis

Abstract: Flow in the rotors of wind turbines with a vertical axis of the Darrieus-Savonius type and their combinations is considered within the framework of the Navier-Stokes equations, in the two-dimensional formulation. A parametric investigation of the Darrieus rotor characteristics is carried out. For all configurations the dependence of the moment and power coefficients on the specific speed of the rotor is calculated. The possibility of the Darrieus rotor self- starting from the state of rest is investigated. The effect of nonmonotonicmoment variation for the Darrieus-type rotor is studied for the specific speeds of 0.5 to 1. A combined design of the Darrieus-Savonius rotor is considered to solve the problems due to a small moment of the Darrieus rotor during the start.

The partitioning technique of directed cyclic graph for task assignment problem

Abstract: The scheduling and mapping of task graph to processors is considered to be the most crucial NP-complete in parallel and distributed computing systems. In this paper, the theoretical graph application using simple partitioning technique is presented to assign a number of tasks onto two processors. This paper addresses a directed-weighted cyclic graph. The effort is to reduce the graph onto directed acyclic graph. A Kernighan-Lin algorithm is applied to obtain the partition of tasks. Combining the technique of reduction and partitioning lead to an efficient graph-mapping concept.

Numerical and Experimental Analysis of Radial Clearance Influence on Rotor and Stator Clocking Effect by Example of Model High Loaded Two Stage Compressor

Abstract: It is ascertained that optimization of bladed rows clocking positions is an effective tool for control of bladed rows unsteady interaction in a multistage turbo machine and could be used equally in refinement and in compressor design stages [1–3].Up to now the clocking effect issue of highly loaded rotors in compressor stages was not investigated due to growing design complexity of the experimental facility. The issue concerning tip clearances value influence on rotor and stator clocking effects was not studied as well.In the frames of this work a two stage compressor (HPC2 with the designed pressure ratio π* = 3.7 [4]) with a unique design was developed to investigate influence of tip clearance values on rotor and stator clocking effect. In order to realize the clocking effect the HPC2 compressor has the following parameters: numbers of stator blades are identical for all stators and equal to ZIGV = ZS1 = ZS2 = 68; number of R1 blades is two times less than of R2: ZR2 = 56, ZR1 = 28.This work studies HPC2 compressor performances at 3 R1 and R2 tip clearances — dtip = 0.5mm – nominal clearance, 0.75mm, and 1.0 mm – increased clearance. Clocking effects of stators and rotors are tested at 0.5mm and 0.75mm tip clearances for two values of corrected rotational speeds — n = 0.7 and 0.88. As shown, variations in max. efficiency from maximum to minimum when changing the clocking position both the stator and the rotor reach Δη*ad≈0.008÷0.012 at dtip = 0.5mm or Δη*ad≈0.007÷0.008 at dtip = 0.75mm.For more detailed analysis of the tip clearance influence on rotor and stator clocking effect a mathematical model of HPC2 was developed on base of through flow 3D viscous unsteady flow computations in the HPC2 compressor rows [3–4]. In full unsteady statement the calculation domain includes the following number of blade rows: IGV = 2, R1 = 1, S1 = 2, R2 = 2; S2 = 2.Copyright © 2014 by ASME

Experimental and numerical investigation of jet flap interaction effects

Abstract: The influence of the wing and flaps geometry on the flow field and acoustic radiation of the jet are experimentally and numerically investigated. The azimuth non-uniformity of jet acoustic field was experimentally defined with a help of far-field microphones, flow field within the jet was measured using PIV technique and numerically calculated with a help high resolution combined RANS/ILES method. The jet flaps interaction (JFI) effects was experimentally and numerically investigated at facility under modeling of real by-pass nozzle configuration and outflow parameters. The comparison between measured flow-field and noise of a jet shows that JFI excess noise is mainly related to jet deformation and increasing of velocity gradients and turbulence within jet which are induced by tip flap vortexes.

Blood flow through a stenosed artery bifurcation under the effects of gravity

Abstract: Circulatory system in human body is built up by network of blood vessels which includes numerous bifurcations. This study presents the influences of bifurcation geometry under the effects of gravity and an irregular stenosis. Along the studied vessel, blood is treated as an incompressible Newtonian fluid. In this paper, an unsteady two-dimensional nonlinear model is developed, where significant gravity term are added to the governing equations. The selected numerical method for the problem is the Marker and Cell (MAC) method based on finite difference approximations. The governing equations are discretized to uniform staggered grids before developing the algorithm in Matlab software. Furthermore, successive-over-relaxation (S.O.R.) method is used to solve the Poisson equation of pressure. Then, pressure-velocity corrector is implied to improve accuracy of the results obtained. The results are presented graphically.

An insight into the science of unstructured meshes in computer numerical simulation

Abstract: Computer numerical simulation is a beneficial tool for studying various domains of knowledge. Among the steps in the whole process of numerical simulation is the generation of unstructured meshes. Since the unstructured meshes are usually generated using automatic software, the fundamental knowledge of the unstructured meshes is often neglected. This paper highlighted some useful insights into the unstructured meshes in numerical simulation for several application domains, such as the radiative heat transfer problem, ocean modelling and biomedical engineering. It also reviewed some fundamental concepts and frameworks for element generation in producing unstructured meshes, particularly the Delaunay triangulation and advancing front techniques.

Linear-time heuristic partitioning technique for mapping of connected graphs into single-row networks

Abstract: In this paper, a model called graph partitioning and transformation model (GPTM) which transforms a connected graph into a single-row network is introduced. The transformation is necessary in applications such as in the assignment of telephone channels to caller-receiver pairs roaming in cells in a cellular network on real-time basis. A connected graph is then transformed into its corresponding single-row network for assigning the channels to the caller-receiver pairs. The GPTM starts with the linear-time heuristic graph partitioning to produce two subgraphs with higher densities. The optimal labeling for nodes are then formed based on the simulated annealing technique. Experimental results support our hypothesis that GPTM efficiently transforms the connected graph into its single-row network.

Free vibration of symmetric angle-ply laminated circular cylindrical shells

Abstract: Free vibration of symmetric angle-ply laminated circular cylindrical shells is studied using Spline approximation. The equations of motions in longitudinal, circumferential and transverse displacement components, are derived using Love's first approximation theory. The coupled differential equations are solved using Spline approximation to obtain the generalized eigenvalue problem. Parametric studies are performed to analyse the frequency response of the shell with reference to the material properties, number of layers, ply orientation, length and circumferential node number and different boundary conditions.

A New Homotopy Analysis Method for Approximating the Analytic Solution of KdV Equation

Abstract: In this study a new technique of the Homotopy Analysis Method (nHAM) is applied to obtain an approximate analytic solution of the well-known Korteweg-de Vries (KdV) equation. This method removes the extra terms and decreases the time taken in the original HAM by converting the KdV equation to a system of first order differential equations. The resulted nHAM solution at third order approximation is then compared with that of the exact soliton solution of the KdV equation and found to be in excellent agreement.

Numerical Investigations of Tonal Noise of Counter-Rotating Open Rotors:

Abstract: In the work are presented the results of a three dimensional computational analysis of tonal noise of two counter-rotating open rotors. The analysis was performed using 3DAS (3 Dimensional Acoustics Solver) CIAM in-house solver, designed for three dimensional calculation of turbomachinery tone noise generation, propagation and radiation in the near and the far acoustic fields. The results of the computations were compared with the results of experiments performed in the wind tunnel of Central Aerohydrodynamic Institute (TsAGI), Russia, within the project DREAM (Validation of radical engine architecture systems) of European Seventh Framework Programme (FP7). The comparison showed satisfactory correspondence between directivity diagrams for the tone noise on combinational harmonics.

Development challenges of distributive propulsion systems for advanced aeroplanes

Abstract: Purpose – This paper aims to consider main challenges of development of advanced architectures of propulsion systems, i.e. distributed propulsion systems (DPS). Design/methodology/approach – This paper is a comparative analysis of different types of DPS. Findings – Mechanical driving DPS seems as more feasible in near-term outlook, and turboelectric and full electric DPS are imagined feasible in mid- and far-term outlook. Research limitations/implications – Additional comprehensive numerical and experimental researches are needed to approve the efficiency of DPS. Practical implications – Possible impact of installation of DPS on aeroplane fuel efficiency are shown. Originality/value – Application of DPS on long-range aeroplanes is new a engineering solution, which may allow to meet future advanced efficiency goals.

Efficiency assessment of HPS for advanced airliners using different fuels

Abstract: Purpose – The purpose of the conducted investigations is assessment of performance improvement of hybrid gas-turbine engine (HGTE) based on solid oxide fuel cell (SOFC) using cheaper and environmental alternative fuels (AF) such as liquid methane and propane – butane mixture (propane – butane). This paper also assessed the efficiency of mid-flight propulsion system (PS) based on HGTE for advanced short – medium hall aircrafts (SMHA) of 2025 (with level of parameters corresponding to technologies of 2025-2030 time period). Design/methodology/approach – According to purposes of this paper, following are conducted: Analysis of properties of conventional and advanced aviation fuels, updating of architectures and parameters of energy system of HGTE based on SOFC using different fuels (kerosene, methane and propane – butane). Examination of rational architectures and updating of possible design parameters of HGTE using different types of fuel. Assessment of efficiency of PS with HGTE using different fuels under...

Rotation of the thrust vector of a two-dimensional nozzle by means of displacing the critical surface

Abstract: The method of thrust vector deflection by means of displacing the critical surface of a nozzle is numerically and experimentally investigated. The displacement is realized at the expense of extending rotatable walls, or deflectors, into the flow; in this case, one of the edges of the critical surface is displaced from the throat onto the deflector surface. Two nozzle configurations, with short and long deflectors, are studied. The thrust vector deflection angles and the nozzle thrust coefficients are determined in the thrust vector deflection regime. For the configuration with long deflectors the angle of rotation of the thrust vector amounts to 30° and is determined by the effect of jet ejection toward the opposite wall, similar with the Coanda effect.

Stochastic growth logistic model with aftereffect for batch fermentation process

Abstract: In this paper, the stochastic growth logistic model with aftereffect for the cell growth of C. acetobutylicum P262 and Luedeking-Piret equations for solvent production in batch fermentation system is introduced. The parameters values of the mathematical models are estimated via Levenberg-Marquardt optimization method of non-linear least squares. We apply Milstein scheme for solving the stochastic models numerically. The effciency of mathematical models is measured by comparing the simulated result and the experimental data of the microbial growth and solvent production in batch system. Low values of Root Mean-Square Error (RMSE) of stochastic models with aftereffect indicate good fits.

Approximate Calculation of Channel Flows under Force and Energy Actions

Abstract: Gasdynamic channel flows under force and energy actions are considered. An approximate method is proposed for solving the gasdynamic equations that describe these flows. Themethod includes the separation of an “active” flow volume in which the integral electric force and applied power, whose densities are assumed to be uniform, are concentrated and the numerical integration of the system of hydrodynamic equations over the entire channel (in laminar and turbulent variants) with the piecewise constant force and energy sources obtained. The results of experimental investigation are presented for the flow that arises after two accessories mounted on the opposite walls of the vertical rectangular channel of constant cross-section, which create a dielectric barrier discharge (DBD actuators). This flow is numerically simulated using the method developed. On the basis of the method proposed the flow characteristics are determined for a model subsonic diffuser on whose lower wall, immediately in front of the separation zone, the DBD actuator is mounted. The efficiency of this accessory in reducing the gasdynamic losses is demonstrated.

Comprehensive approach to comparative efficiency evaluation of HPS for helicopters

Abstract: Purpose – The purpose of the work is to carry out analysis of the possibilities and estimation of electric drive efficiency for rotors of helicopter propulsion systems (PS). Design/methodology/approach – Methodology and comprehensive multidisciplinary technology for efficiency estimation of conventional and unconventional architectures PS on rotorcraft system level at preliminary design phase were developed. Findings – Application of the approach allow to carry out analysis of hybrid (based on gas turbine and piston engines) and full electrical PS for superlight-, light- and medium-size helicopters. Practical implications – It was shown what level of electrical technologies improvement may provide positive effect of the using of hybrid and full electrical helicopter PS of different architectures. Originality/value – Close matching of helicopter and engine design and calculation aspects, as well as possibilities to use the external (experimental) performances of engine components, whole PS and helicopter a...

Development of integrated model for continuous berth allocation problem and quay crane scheduling with non crossing constraint

Abstract: High efficiency of port operation is required to succeed in the competition between port container terminals. Berth Allocation and Quay Crane Scheduling are the most important part in container terminal operations. The integrated model is formulated as a MIP problem with the objective to minimize the sum of the dwell times, where a vessel's dwell time is measured between arrival and departure including both times waiting to be berthed and servicing time while berthed. The construction of suitable mathematical model is formulated by considering various practical constraints.

Approximate Analytical Solutions of KdV and Burgers’ Equations via HAM and nHAM

Abstract: This article presents a comparative study of the accuracy between homotopy analysis method (HAM) and a new technique of homotopy analysis method (nHAM) for the Korteweg-de Vries (KdV) and Burgers' equations. The resulted HAM and nHAM solutions at 8th-order and 6th-order approximations are then compared with that of the exact soliton solutions of KdV and Burgers' equations, respectively. These results are shown to be in excellent agreement with the exact soliton solution. However, the result of HAM solution is ratified to be more accurate than the nHAM solution, which conforms to the existing finding.