Showing papers by "Arts et Métiers ParisTech published in 2004"
TL;DR: In this paper, three synthetic and complementary viticultural climatic indices (potential water balance of the soil, heliothermal conditions over the growing cycle, and night temperature during maturation) validated as descriptors, are used: dryness index (DI), which corresponds to the potential water balance, and cool night index (CI), an index developed as an indicator of night temperature conditions during maturity.
582 citations
TL;DR: The role of fungi in biological weathering has attracted a lot of interest as discussed by the authors, although the role of bacteria (Eubacteria, Archaea) has largely been neglected, until recently, however, fungi has become an increasingly important focus of biogeochemical research.
Abstract: No rock at the Earth's surface escapes weathering. This process is the primary source of all the essential elements for organisms, except nitrogen and carbon. Since the onset of terrestrial life, weathering has been accelerated under the influence of biota. The study of biological weathering started at the end of the 19th century. Although the role of bacteria (Eubacteria, Archaea) has attracted a lot of interest, until recently the role of fungi has largely been neglected. More recently, however, fungal weathering has become an increasingly important focus of biogeochemical research.
310 citations
TL;DR: The stereoradiographic 3D-reconstruction method allows for a significant reduction of the whole reconstruction time, with regard to previously described methods, and was found to be comparable to the accuracy of previous methods.
207 citations
TL;DR: Numerical results for long time integration in the scalar case show that the MP one-step approach gives the best results compared to sever multistate schemes, including WENO schemes.
207 citations
TL;DR: PCR amplification, sequencing and phylogenetic analysis of nodA gene sequences revealed the monophyletic character with the possible exception of photosynthetic Bradyrhizobium, despite high sequence diversity, and indicated that the spread and maintenance of nodulation genes within the Bradyrnobia genus occurred through vertical transmission, although lateral gene transfer also played a significant role.
197 citations
TL;DR: To investigate and understand the genetic and physiological basis of drought tolerance in barley, differentially expressed sequence tags (dESTs) and candidate genes for the drought response were mapped in a population of 167 F8 recombinant inbred lines derived from a cross between “Tadmor” (drought tolerant) and “Er/Apm’ (adapted only to specific dry environments).
Abstract: Drought limits cereal yields in several regions of the world and plant water status plays an important role in tolerance to drought. To investigate and understand the genetic and physiological basis of drought tolerance in barley, differentially expressed sequence tags (dESTs) and candidate genes for the drought response were mapped in a population of 167 F8 recombinant inbred lines derived from a cross between “Tadmor” (drought tolerant) and “Er/Apm” (adapted only to specific dry environments). One hundred sequenced probes from two cDNA libraries previously constructed from drought-stressed barley (Hordeum vulgare L., var. Tokak) plants and 12 candidate genes were surveyed for polymorphism, and 33 loci were added to a previously published map. Composite interval mapping was used to identify quantitative trait loci (QTL) associated with drought tolerance including leaf relative water content, leaf osmotic potential, osmotic potential at full turgor, water-soluble carbohydrate concentration, osmotic adjustment, and carbon isotope discrimination. A total of 68 QTLs with a limit of detection score ≥2.5 were detected for the traits evaluated under two water treatments and the two traits calculated from both treatments. The number of QTLs identified for each trait varied from one to 12, indicating that the genome contains multiple genes affecting different traits. Two candidate genes and ten differentially expressed sequences were associated with QTLs for drought tolerance traits.
157 citations
TL;DR: In this paper, two different woven glass-aramid-fibre/epoxy laminates were subjected to water immersion ageing followed by instrumented low velocity impact testing, and the impacted plates were retested statically in compression to determine residual strength for assessment of damage tolerance.
150 citations
TL;DR: Microsequencing of peptides generated by trypsic digestion of bassiacridin confirmed that it is a novel molecule and showed that it exhibits a probably limited similarity with a chitin binding protein from yeast.
148 citations
TL;DR: In this paper, an extensive study has been performed to investigate the tool-wear mechanisms of CBN cutting tools in finish turning of the following hardened steels: X155CrMoV12 (AISI D2) cold work steel, X38 CrMoV5 (A ISI H11) hot work steel.
141 citations
TL;DR: The integrator delay zero (IDZ) model presented by Litrico and Fromion is a simple way to model a canal for control purposes that extends the classical Integrator Delay model as discussed by the authors.
Abstract: The integrator delay zero (IDZ) model presented by Litrico and Fromion is a simple way to model a canal for control purposes that extends the classical integrator delay model. This analytical model gives a very good frequency domain approximation of the Saint-Venant transfer matrix for a pool possibly in backwater conditions. The present paper shows how this model can be used to model an irrigation canal for control design. The IDZ model is analyzed and its accuracy evaluated in the frequency and time domain on two ASCE test canals for high and low flow conditions.
136 citations
TL;DR: The present study shows that the congeneric parasites speciating within one host tend to occupy niches within hosts differing at least in one niche parameter, which can be mainly explained by sympatric intrahost speciation events that seem to be correlated to strict host specificity.
Abstract: Dactylogyrus species (Dactylogyridae: Monogenea) are a group of monogenean gill parasites that are highly specific to freshwater fish of the family Cyprinidae. Dactylogyrus species were sampled from 19 cyprinids and one percid collected in Europe. Using partial 18S rDNA and ITS1 sequences, a phylogeny of 51 Dactylogyrus species was reconstructed to investigate the patterns of parasite speciation and diversification. Three main Dactylogyrus lineages were recognized from all phylogenetic trees, that is, analysis of 18S rDNA alone and combined 18SrDNA and ITS1. The first lineage associates the Dactylogyrus species of Cyprinus carpio and Carassius auratus of the Cyprininae; the second associates Dactylogyrus species of the Gobioninae, Pseudorasbora parva of the Rasborinae, and Ctenopharyngodon idella of the Cyprininae; and the third associates Dactylogyrus species of the Leuciscinae and Alburninae and Barbus barbus of the Cyprininae. Our results suggest that the genus Dactylogyrus is of quite recent origin and that these three lineages separated from each other in a very short period of time. Host subfamily mapping onto the parasite tree inferred from analysis of the combined dataset showed that the Cyprininae could be plesiomorphic hosts for Dactylogyrus. Dactylogyrus parasites would have secondarily colonized the Percidae and representatives of the Leuciscinae, Alburninae, Gobioninae, and Rasborinae. Comparison of host and parasite phylogenetic relationships indicated that a very high number of parasite duplications occurred within two of the three Dactylogyrus lineages. Dactylogyrus diversification can be mainly explained by sympatric intrahost speciation events that seem to be correlated to strict host specificity. Moreover, the present study shows that the congeneric parasites speciating within one host tend to occupy niches within hosts differing at least in one niche parameter.
TL;DR: One of the most significant results was the identification and generation of material that out performed the best local standards in the three participating North African countries; the selected lines have now entered local breeding programmes.
Abstract: A review is presented of genetic strategies deployed in a 3-yr project on drought tolerance in barley. Data were collected on genetic, physiological and agronomic traits in non-irrigated and irrigated field trials in Egypt, Morocco and Tunisia. A wide range of barley germplasm (developed from African and European cultivars, adapted landraces and wild barleys) was tested, and positive traits were found in each gene pool. The contrasting environments of the three North African countries had major effects on plant/genotype performance. Genetic effects were also detected, as were genotype x environment interactions. A range of strategies were deployed to investigate the physiology and genetics of quantitative traits associated with field performance. Quantitative trait locus (QTL) analysis was performed using backcross lines, recombinant inbred lines and doubled haploid mapping populations. A detailed genetic map was generated in the Tadmor x (ER/Apm) recombinant inbred lines, an important mapping population specifically developed by ICARDA (Centre for Agricultural Research in Dry Areas) and CIMMYT (International Maize and Wheat Improvement Center) to study drought. Quantitative trait loci (QTLs) for grain yield and other important morphological and physiological traits were also identified in a population of doubled haploids derived from F 2 BC 1 plants from a cross between a cultivar and a wild barley accession. Significantly, the wild parental line was found to contribute a number of positive alleles for yield. Effects of major developmental genes could explain many of the responses observed. QTLs were found to cluster around major genes controlling flowering time (sghl), plant stature (sdw1 and ari-e.GP) and ear type (vrs1), and it is highly likely that the associations represent pleiotropic effects. Some QTLs were associated with candidate genes such as dehydrins and rubisco activase. One of the most significant results was the identification and generation of material that out performed the best local standards in the three participating North African countries; the selected lines have now entered local breeding programmes. The strategies adopted provided information on physiological traits, genotypes and genetic markers that could be used for marker-assisted selection. Target QTLs and their associated genetic markers may be deployed in marker assisted selection programmes to match crop phenology to the field environment.
TL;DR: In this article, the applicability of the Iosipescu and off-axis test methods for the shear characterization of clear wood was investigated, and it was shown that the IOSIPescu test gives lower and upper bounds of shear strengths, whereas the Off-Axis test gives only a lower bound.
Abstract: In this work, the applicability of the Iosipescu and off-axis test methods for the shear characterization of clear wood was investigated. Wood of maritime pine (Pinus Pinaster Ait.) was used. Iosipescu shear tests were carried out for oriented specimens in the three natural symmetry planes of wood (LR, LT and RT planes), whereas off-axis tests were performed only in the LR and LT planes. Finite element analyses were conducted in order to access the stress and strain fields in the test section of the specimens. It was found that the Iosipescu and off-axis tests provide different shear moduli values. It was also shown that the Iosipescu test gives lower and upper bounds of shear strengths, whereas the off-axis test gives only a lower bound, directly from the measured loads.
TL;DR: In this article, an approach to predict high cycle fatigue behavior of shot-peened parts based on the multi-axial high-cycle fatigue criteria of Crossland and Dang Van was presented.
TL;DR: In this paper, the effect of adding pozzolan or sawdust in lateritic soil bricks on the thermal properties of bricks was investigated. But, the results of the experiments were limited.
TL;DR: It is suggested that identification of the QTL of parameters of response curves provides a promising alternative for dealing with the genetic variability of adaptive traits.
Abstract: Quantitative genetics of adaptive traits is made difficult by the genotypexenvironment interaction. A classical assumption is that QTLs identified in both stressed and control conditions correspond to constitutive traits whereas those identified only in stressed treatments are stress-specific and correspond to adaptive traits. This hypothesis was tested by comparing, in the same set of experiments, two ways of analysing the genetic variability of the responses of maize leaf growth to water deficit. One QTL detection was based on raw phenotypic traits (length and width of leaf 6) of 100 recombinant inbred lines (RILs) in four experiments with either well-watered or stressing conditions in the field or in the greenhouse. Another detection followed a method proposed recently which consists of analysing intrinsic responses of the same RILs to environmental conditions, determined jointly over several experiments. QTLs of three responses were considered: (i) leaf elongation rate per unit thermal time in the absence of stress, (ii) its response to evaporative demand in well-watered plants, and (iii) its response to soil water status in the absence of evaporative demand. The QTL of leaf length differed between experiments, but colocalized in seven cases out of 13 with QTLs of the intrinsic leaf elongation rate, even in experiments with stressing conditions. No colocalization was found between QTLs of leaf length under water deficit and QTLs of responses to air or soil water status. By contrast, QTLs of leaf width colocalized in all experiments, regardless of environmental conditions. The classical method of identifying the QTL of constitutive versus adaptive traits therefore did not apply to the experiments presented here. It is suggested that identification of the QTL of parameters of response curves provides a promising alternative for dealing with the genetic variability of adaptive traits.
TL;DR: It is shown that the ethylene signal transduction pathway could be involved in the control of VvADH2 expression in grapevine berries and in cell suspensions, and new aspects of the expression control of a ripening-related gene in a non-climacteric fruit are opened.
Abstract: Although grape berries have been classified as non-climacteric fruits, ongoing studies on grape ethylene signalling challenge the role of ethylene in their ripening. One of the significant molecular changes in berries is the up-regulation of ADH (alcohol dehydrogenase, EC 1.1.1.1) enzyme activity at the inception of fruit ripening and of VvADH2 transcript levels. This paper shows that the ethylene signal transduction pathway could be involved in the control of VvADH2 expression in grapevine berries and in cell suspensions. The induction of VvADH2 transcription, either in berries at the inception of ripening or in cell suspensions, was found to be partly inhibited by 1-methylcyclopropene (1-MCP), an inhibitor of ethylene receptors. Treatment of cell suspensions with 2-chloroethylphosphonic acid (2-CEPA), an ethylene-releasing compound, also resulted in a significant increase in ADH activity and VvADH2 transcription under anaerobiosis, showing that concomitant ethylene and anaerobic treatments in cell suspensions could result in changes in VvADH2 expression. All these results associated with the presence in the VvADH2 promoter of regulatory elements for ethylene and anaerobic response, suggest that the ethylene transduction pathway and anaerobic stress could be, in part, involved in the regulation of VvADH2 expression in ripening berries and cell suspensions. These data open new aspects of the expression control of a ripening-related gene in a non-climacteric fruit.
15 May 2004-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, a micromechanical model based on a self-consistent formulation has been applied to describe the elastic-viscoplastic behavior of steels with different microstructures in a wide range of strain rates.
Abstract: A micromechanical model based on a new and non-conventional self-consistent formulation has been applied to describe the elastic-viscoplastic behavior of steels with different microstructures in a wide range of strain rates. Good agreement between experimental and model predictions is found concerning the behavior of a ferritic single-phase interstitial free steel (IF) during quasi-static and dynamic tensile loadings. Due to the introduction of key physical parameters in the mathematical model, a good description is obtained of the differences observed between the constitutive behaviors of IF, high-strength low alloy (HSLA) and dual-phase (DP450, DP500 and DP600) steels. These differences concern strength, strain hardening as well as strain rate sensitivity.
TL;DR: This is the first evaluation of sucrose and trigonelline contents involving 14 species and six new taxa not yet botanically characterised and found that C. canephora could be improved through both compounds by crosses with Coffea eugenioides.
TL;DR: In this article, the authors present results on the variation in density and shrinkage of banana during its drying, considering that the variation of the product volume was equal to the volume of the evaporated water.
25 Jul 2004-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, the authors used X-ray diffraction to determine the kinetics of transformation at various temperatures and found that at low temperatures, the retained austenite transforms into martensite very rapidly, whereas the transformation is much slower at high temperatures.
Abstract: The mechanical behavior of transformation induced plasticity (TRIP) steels depends on the martensitic transformation of the retained austenite. The studied material is a three-phase TRIP steel with ferrite base containing less than 1% of bainite and 8% of retained austenite. Tensile tests were performed at various temperatures ranging from −60 to +120 °C. X-ray diffraction was used to determine the kinetics of transformation at various temperatures. First results show that at low temperatures, the austenite transforms into martensite very rapidly, whereas the kinetics of transformation are much slower at high temperatures. The stress state in the austenite at room temperature was also obtained by X-ray diffraction. After pre-strain, it is noticed that retained austenite is in tension probably due to the carbon content which is more important in austenite than in ferrite.
TL;DR: In this article, a kinetic model for polymer thermal oxidation derived from the standard mechanistic scheme, in which initiation is only due to (uni and bimolecular) hydroperoxide decomposition, has been elaborated.
TL;DR: In this paper, a model is developed to analyze the heat transfer and temperature distribution in rotary tool turning of hardened 52100 steel (58 HRC) using the moving heat source theory of conduction and employs the finite element method (FEM) for its solution.
Abstract: This paper addresses modeling of the tool temperature distribution in self-propelled rotary tool (SPRT) machining of hardened steels Since tool life is significantly influenced by cutting temperatures, a model is developed to analyze the heat transfer and temperature distribution in rotary tool turning of hardened 52100 steel (58 HRC) The model is based on the moving heat source theory of conduction and employs the finite element method (FEM) for its solution The model is experimentally verified through measurements of the cutting tool temperature distribution using an infrared camera under different cutting conditions Finally, both rotary and equivalent fixed tool cutting processes are compared in terms of cutting tool temperatures generated
TL;DR: In this article, a material direction-dependent constitutive model for large deformations for isotropic and anisotropic rubber-like materials was formulated, where the material directions have simply been chosen using regular solid geometry.
TL;DR: It was found that a one-level change in the instrumentation limit may have a significant effect on spine alignment and correction and three alternative surgical strategies were investigated.
Abstract: The Cotrel–Dubousset (CD) scoliosis surgery was simulated for 10 patients with idiopathic scoliosis using a 3D finite element model (FEM) of the patient’s entire spine. The geometry of the FEM was extracted from a 3D stereo-radiographic reconstruction, and mechanical properties were personalized using lateral bending films. Finally, each step of the CD correction was simulated and results were compared with the post-operative 3D stereo-radiographic reconstruction. The whole procedure was applied for 10 patients, and quantitative comparison was performed between post-operative spine configuration and predicted configuration. For all patients, mean differences between post-operative measurements and predicted values of vertebral rotation were estimated at 58 (max: 138) and those for linear position at 6 mm (max: 12 mm). Furthermore, intermediate steps of surgery simulation were consistent with the literature. Then, for one scoliotic patient, the model was used to investigate three alternative surgical strategies. It was found that a one-level change in the instrumentation limit may have a significant effect on spine alignment and correction.
TL;DR: The C-NEM technique provides a description of integration cells that allows the use of the stabilized conforming nodal integration (SCNI) scheme instead of Gauss integration to enhance computational efficiency and accuracy.
Abstract: In this paper a new extension of the mesh-free natural element method (NEM) is presented. In this approach, coined as constrained natural element method (C-NEM), a visibility criterion is introduced to select natural neighbours in the computation of the shape functions. The computation of these shape functions is based on a modified, constrained Voronoi diagram. With this technique, some difficulties inherent to this method in non-convex domains are avoided and the analysis of problems involving cracks or discontinuities are now easily performed. As the NEM satisfies the Kronecker delta property, the imposition of essential boundary conditions is trivial, unlike other mesh-free methods. The C-NEM technique provides a description of integration cells that allows the use of the stabilized conforming nodal integration (SCNI) scheme instead of Gauss integration to enhance computational efficiency and accuracy. Two numerical examples in elastostatics are reported to evaluate the potential of the proposed technique in highly non-convex geometries, like a crack, through which the solution becomes discontinuous.
TL;DR: Using a B-spline representation for splines with knots seen as free variables, the approximation to data by splines improves greatly and is comparable with other more sophisticated techniques and is very attractive for a small number of variables.
TL;DR: A simulated data‐based comparison of six of the most cited methods in the literature of the last 20 years to estimate the parental contributions in the genetic pool of an admixed population of honeybee populations finds no method is always better or worse than all others.
Abstract: Several methods have been developed to estimate the parental contributions in the genetic pool of an admixed population. Some pair-comparisons have been performed on real data but, to date, no systematic comparison of a large number of methods has been attempted. In this study, we performed a simulated data-based comparison of six of the most cited methods in the literature of the last 20 years. Five of these methods use allele frequencies and differ in the statistical treatment of the data. The last one also considers the degree of molecular divergence by estimating the coalescence times. Comparisons are based on the frequency at which the method can be applied, the bias and the mean square error of the estimation, and the frequency at which the true value is within the confidence interval. Eventually, each method was applied to a real data set of variously introgressed honeybee populations. In optimal conditions (highly differentiated parental populations, recent hybridization event), all methods perform equally well. When conditions are not optimal, the methods perform differently, but no method is always better or worse than all others. Some guidelines are given for the choice of the method.
TL;DR: In this article, the authors tried to explain why isotactic polypropylene (PP) is stiffer than high density polyethylene (HDPE) despite the fact that this latter is more crystalline and that its crystallites are stiffier than PP ones.
01 Nov 2004
TL;DR: In this article, a vector control of an n-phase permanent magnet synchronous machine with trapezoidal waveform back EMF has been studied, where the first and third harmonics are used to produce torque.
Abstract: This paper deals with a vector control of n-phase permanent magnet synchronous machine. To use control algorithms already developed for sine-wave 3-phase machines, the spectrum of back electromotive force (EMF) must contain only odd 2k+1 harmonics which verify the following inequality, 1 /spl les/ 2k+1 < n. In an experimental vector control of a 5-phase drive, two usual algorithms of sine-wave 3-phase machine are thus used to supply a machine with trapezoidal waveform back EMF. In this case, the first and third harmonics are used to produce torque: the other harmonics, and particularly the 7/sup th/ one, induce effects as torque ripples and parasitic currents.