Paris Model Research Articles

Damage mechanism of a nodular cast iron under the very high cycle fatigue regime

Fatigue behaviour in the very high cycle regime (VHCF) of 10 10 cycles were investigated with a cast iron (GS51) under ultrasonic fatigue test system (20 kHz) in ambient air at room temperature with a stress ratio R = −1. The influence of frequency was examined by comparing similar data generated on conventional servo hydraulic test systems. An advanced, high-speed, and high-sensitivity infrared imaging system was used to measure the temperature changes during ultrasonic fatigue test at various load levels caused by internal damping due to a very high frequency cycling. The temperature field on the surface specimen was determined by using a non-destructive measurement technique called infrared pyrometer. An infrared camera made up of a matrix of 320 × 240 detectors was used. The S-N curves obtained show that fatigue failure occurred beyond 10 9 cycles, fatigue limit does not exist for the cast iron and there is no evidence of frequency effect on the test results. A detailed study on fatigue specimens subjected to ultrasonic frequency shows that the temperature evolution of the cast iron specimen is very evident, the temperature increased just at the beginning of the test, the temperature increased depending on the maximum stress amplitude. Under the current test conditions, the high cycle fatigue (VHCF) behaviour of the cast iron exhibited a typical fatigue crack growth process, that is, fatigue initiation takes place always at the surface graphite or subsurface void; the distinctive stable fatigue crack growth zone can be found around the fatigue crack initiation site, the change of fatigue initiation site from surface to subsurface is associated with the complex effects of applied maximum stress level, surface condition. Under lower stress amplitude and high cycle condition, surface graphite fatigue initiation is predominantly depended on cyclic stress amplitude; subsurface void fatigue initiation is determined by maximum cyclic stress. In the process of small crack propagation, the temperature in local plastic zone increase very sharply. The temperature field of ultrasonic fatigue specimen can be changed with the cooling condition; internal heating can accelerate surface fatigue crack initiation and propagation. Fatigue properties in VHCF regime were studied for cast iron (GS51) at 20 kHz frequency and for the first time, crack initiation and propagation stages were analyzed using a high-sensitivity infrared camera. The new Paris's model for fish eye formation in the gigacycle fatigue were also confirmed by this study.

The Invention of the Model: Artists and Models in Paris, 1830 1870

In 1856, the energetic Léon de Laborde (diplomat, traveller, conservator and writer), suggested a nineteenth-century version of outsourcing as one solution to France's artistic ills. In Laborde's opinion, French painters and sculptors were making do with a sorry selection of artists' models. Socially and even ethnically inferior (Jewish models were supposedly abundant), the lowly origins of these service workers in Parisian studios infected their every painted or chiselled representation. A work of art was supposed to transport the viewer, not leave her with the uncomfortable realization that many a former labourer or prostitute had been immortalized on canvas or in marble. An eagerness to strike ‘affected poses’ made this awareness more grating. The strength of Laborde's allergy to mugging bears out the relevance of Michael Fried's work to Waller's concern for ‘the praxis of the pose’. In addition, Paul Duro, drawing on Marc Gotlieb's study of Ernest Meissonier, has recently underlined the extraordinary measures taken by the latter at mid-century in staging the model via a set of re-imagined Naturalist practices. Laborde's exasperation thus reflected widespread contemporary concerns about the status of the model. Laborde however, was moved to wonder if the representatives of ‘beautiful races’ — Italy received reverential mention, although his menu was global — could don the attire of Achilles or Venus with greater verisimilitude.

Validation of the Arya and Paris Water Retention Model for Brazilian Soils

The Arya and Paris (AP) model predicts soil water retention curves from soil particle‐size distribution (PSD) data based on the similarity between these two functions. The AP model estimates pore radius (ri) from the radius (Ri) of spherical particles by scaling pore length with a parameter α. This paper evaluates the performance of the AP model with representative Brazilian soil types using three constant α values: α = 1.38, 0.938 (literature values), and 0.977, (obtained in the present work); and a α‐variable approach, where α is determined as a function of soil water content (θ). The study was performed with 104 soil samples collected in three sites. The soil PSD curves were obtained with an automatic soil particle analyzer based on the attenuation of γ‐ray by dispersed soil particles falling in a liquid medium and the soil water retention were measured with tension table and Richard chamber methods. The best mathematical representation of the α = f(θ) relationship was obtained with a first‐order exponential decay equation [α = 0.947 + 0.427exp(−θ/0.129)] that provided values of α in the range from 1.37 (θ = 0 m3 m−3) to 0.96 (θ = 0.6 m3 m−3). The root mean square deviation values of estimated and measured θ were 0.062 m3 m−3 for α = f(θ), 0.073 m3 m−3 for α = 0.977, 0.080 m3 m−3 for α = 0.938, and 0.136 m3 m−3 for α = 1.38. Therefore, for these set of soils the α‐variable approach and the constant ones using 0.977 and 0.938 presented the best estimation for the soil water retention relationships.

Models of set theory with definable ordinals

A DO model (here also referred to a Paris model) is a model Open image in new window of set theory all of whose ordinals are first order definable in Open image in new window. Jeffrey Paris (1973) initiated the study of DO models and showed that (1) every consistent extension T of ZF has a DO model, and (2) for complete extensions T, T has a unique DO model up to isomorphism iff T proves V=OD. Here we provide a comprehensive treatment of Paris models. Our results include the following:

Analogue (plaster) modelling and synthetic seismic representation of hangingwall fault

The complex structuring associated with ramp-flat-ramp extensional master faults, as well as the strain pattern in the hanging-wall fault block of such faults, have been analysed with the help of analogue Plaster of Paris models. This analysis shows that the shallow-dipping master fault commonly develops several fault branches due to either asperity bifurcation or hanging-wall and footwall splaying, and that the deeper parts of steeper early generation faults are sometimes cut by younger faults. This generates a very complex fault pattern in the deeper part of the hanging-wall fault block. Based on the analogue models, the possibility of generating synthetic reflection seismograms by the use of simple modelling techniques (ray tracing and finite-difference models) has been investigated. It is concluded that the two methods produce significantly different results in terms of resolution and noise. The ray-tracing method resulted in a highly idealized image that can be viewed as the end product after an idealized processing sequence in that no noise, no multiples or other artefacts are incorporated. Furthermore, all reflections are in the correct position and are displayed with the correct amplitude in each case. Although the result can be used as a good reference for what can be obtained by simple seismic modelling, the weak aspect of this method is obviously the over-simplified and unrealistically ‘clean’ image presented. A more ‘realistic’ reflection seismic image is obtained in cases where the synthetic seismogram is generated by the finite-difference method. However, the structural features stand out with less clarity, and it is less likely that the interpreter of this section would be able to identify the two master fault planes or to distinguish the complex structural pattern in the deep part of the hanging-wall fault block.

More about the comparison of local and non-local NN interaction models

The effect of non-locality in the NN interaction with an off-energy shell character has been studied in the past in relation with the possibility that some models could be approximately phase-shifts equivalent. This work is extended to a non-locality implying terms that involve an anticommutator with the operator p 2. It includes both scalar and tensor components. The most recent “high accuracy” models are considered in the analysis. After studying the deuteron wave functions, electromagnetic properties of various models are compared with the idea that these ones differ by their non-locality but are equivalent up to a unitary transformation. It is found that the extra non-local tensor interaction considered in this work tends to re-enforce the role of the term considered in previous works, allowing one to explain almost completely the difference in the deuteron D-state probabilities evidenced by the comparison of the Bonn-QB and Paris models for instance. Conclusions for the effect of the non-local scalar interaction are not so clear. In many cases, it was found that these terms could explain part of the differences that the comparison of predictions for various models evidences but cases where they could not were also found. Some of these last ones have been analyzed in order to pointing out the origin of the failure.

Posing the "Belle Juive": Jewish Models in 19th-Century Paris

Posing the "Belle Juive": Jewish Models in 19th-Century Paris

Design of Porous Media for Optimal Gas and Liquid Fluxes to Plant Roots

AbstractThe selection of plant growth media remains an empirical endeavor often focusing on available materials rather than on the physical principles that govern water retention and flow. Apparent water‐ and O2‐induced stresses affecting plant growth experiments in microgravity (10−3–10−6 g0) have prompted the need for refinement of selection criteria for optimal growth media. The objective of this work was to develop a comprehensive approach for selecting the physical characteristics of plant growth media that optimize the dynamic availability of liquids and gases to plant roots. Physically based models describing the relationship between content and fluxes of liquids and gases were written in terms of media parameters and were used to cast a multi‐objective optimization problem. Plant physiological target values, growth container design, and other system considerations provided constraints for the optimization problem. The optimized media parameters designated a pore‐size distribution (psd) that is scaled to a corresponding particle‐size distribution (PSD) by inversion of the Arya and Paris model. The iterative process resulted in an average scaling of psd to PSD and led to the synthesis of an optimal medium. Sand and glass bead mixtures were well matched to the optimized media characteristics resulting from the optimization procedure. This methodology is amenable to horticultural, greenhouse, and research applications where optimal porous media design is of value.

Some aspects of fatigue crack growth retardation behaviour following tensile overloads in a strucutural steel : Shuter, D.M. and Geary, W. Fatigue Fract. Eng. Mater. Struct. (1996) 19 (2–3), 185–199

Fatigue crack growth behaviors of cold-rolled dual phase steels with different microstructures were investigated at room temperature. The ferrite–martensite dual-phase microstructure was obtained by intercritical annealing. Fatigue crack growth (FCG) behaviors were described by both the Paris model and a new exponential model; fatigue fractography and surface morphology near the fracture were arrested by scanning electron microscopy (SEM); the relationship between macroscopic and microcosmic FCG rate was analyzed quantificationally. The results showed that both the models can be used to describe the fatigue crack growth rate of the samples rather well; fatigue striations and secondary cracks were observed in the fracture surface at stable expanding region (II), while the fracture at rapid expanding region (III) combined dimple and quasi-cleavage morphology; the roughness of fracture surface and the degree of secondary cracking increased with an increase in martensite content, leading to a higher threshold value. Moreover, the changes of microcosmic FCG rate were smoother than that of the macroscopic FCG rate.

Experimental corrections of simplified methods for predicting water retention curves in clay-loamy soils from particle-size determination

The Arya and Paris model for predicting soil water retention curves from particle-size distribution data is a commonly accepted method for rigid soils with medium grain size but limitations to its application for fine textured soils occur, due to the dominant role of internal structure in such soils. Moving from the consideration that simplified models for determining soil hydraulic characteristics may be usefully adopted to reduce laboratory investigation costs, in this study an attempt is made to extend the Arya-Paris formulation to clay-loamy soils by means of an experimental calibration function which takes into account the effective soil water retention behaviour. The methodology is based on an inversion procedure of the Arya-Paris model from observed values of water retention and potential during evaporation processes on undisturbed soil columns. It has been found that the resulting calibration function is typical for each soil and it substantially improves the prediction of the soil water retention curve from textural information.

Are all models of the NN interaction independent of each other?

Abstract Models of the NN interaction are most often considered as independent of each other, and it is generally believed that experiments could allow one to discriminate them. It has, however, been shown that there may be some relationship between models designed to be used in momentum and configuration spaces. This relationship is expressed by a unitary transformation. Its consequences for the charge and quadrupole deuteron form factors were investigated in the case of the π-exchange contribution to the NN interaction. For this interaction, the Bonn (Q b ) and Paris models were considered as representative models of momentum and configuration spaces respectively. The above work is extended to the ϱ-exchange contribution on the one hand and to the deuteron magnetic form factor and the form factor for deuteron electrodisintegration near threshold on the other hand. Sensitivity to various inputs is discussed.

L'embellie parisienne à la Belle Époque : l'invention d'un modèle de consommation

The Paris Belle Epoque lull: inventing a consumption model, François Caron. The economic dynamism of Paris at the time of the Belle Epoque was based both on the development of sectors linked to the second industrialization (electricity, the chemical industry, automobiles) and to the renewal of traditional industries (the garment industry, cosmetics, jewelry) centered on luxury goods and benefiting from a skilled workforce. The rise of factories located in the suburbs led to the reorganization of urban space around these new activities. The progress of hygiene and the development of mass transportation paralleled the general rise of standards of living and increasing access to comfort. With the spread of movies, leisure activities, travel as well as fashion thanks to the departement stores, this dynamism brought about a deep change in consumption habits. It was also fortered by a dynamic entrepreneurial class capable of responding to demand by adapting production and distribution techniques to the social diversity of Paris. Contrary to the pessimistic vision of a "blocked society", a Paris model of "industrial achievement" thus developed, marking the entry of the capital into the consumption society, and an example to the other metropolises of the industrialized world.

A Simple Method for Predicting the Spatial Distribution of Soil Hydraulic Properties

AbstractWe developed a method to calculate the statistical distribution of a scaling factor from soil‐water retention curves. The method consists of measuring the particle‐size distribution by laser scattering, computing soil water retention curves using the Arya and Paris model, and calculating a scale factor for each function. The method was tested by comparing measured and predicted soil‐water retention curves. The advantage of this method is in its simplicity and ease of use. The applicability of the method to a given soil texture depends on the verification of the calculated soil‐water retention functions.

Zoologische Gärten in Stadtkultur und Wissenschaft im 19. Jahrhundert

AbstractThe foundation and administration of European Zoological gardens in the 19th century is analized. It is significant of such new institutions, that they are founded in the large cities, and that most of the founders looked at the great models in Paris and London, which are described first. Further it is shown that the change from princely menageries to public Zoological Gardens is caused both by common interests in people's education and pleasure and by scientific aims which leaded to choose the name Zoological “garden” in analogy to botanical gardens. It seems to be characteristic of such public institutions created by citizens in the 19th century that they are mostly supported by commercial or scientific local societies. This is exemplified by describing the administration of the Zoological gardens of Berlin (1841), Frankfurt (1856) and Hamburg (1863), which initiated also research for acclimatization of wild animals.

Fatigue models for Al alloys

The Paris and Collipriest models of fatigue crack growth have been applied to experimental data on Al alloys. A pivot point, common to all the tests carried out on the same material, has been shown to exist when the Paris model is adopted. A mobile pivot, which is a function of the load ratio R, is suggested to exist using the Collipriest model on different sets of Al alloy experimental data. Pairs of parameters, A and B, as defined in this paper, can characterize the fatigue crack propagation behaviour of each alloy, irrespective of the load ratio R.

An examination of cyclic grain boundary migration and cavitation in an Al3Mg solid solution alloy: Raman, V. and Langdon, T.G. Acta Metall. Feb. 1989 37, (2), 725–737

The purpose of this study was to analyze the microstructure of lath martensite in 0.1C–1.1Si–1.7Mn (wt.%) steel and its effect on mechanical properties and fracture behavior. The microstructure was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and electron back scattering diffraction (EBSD). Charpy V-notch impact samples and compact tension (CT) samples were used to investigate the Charpy impact properties and fatigue crack growth behavior of the steel, respectively. The propagation of cleavage crack and fatigue crack were analyzed to figure out the effective grain size. The results showed that the typical hierarchical lath martensite structure contained prior austenite grains, packets, blocks and laths; packet size and block width were positively correlated to prior austenite grain size, while lath width was maintained at about 0.29 μm. Yield strength was related to prior austenite grain size, packet size and block width, and obeyed Hall–Petch relationship. Grain refinement was effective in improving the resistance to cleavage fracture by introducing barriers to crack propagation; packet boundaries and block boundaries hold similar ability to impede the propagation of crack. Paris model can well describe the FCG behavior of the investigated steel. Block width governs the effective grain size for strength, toughness and fatigue crack propagation.

Fish-eye fracture in high-cycle fatigue at elevated temperatures: Kanazawa, K., Sato, M., Kimura, M. and Nishijima, S. J. Soc. Mater. Sci., Jpn. Dec. 1988 37, (423), 1423–1428 (in Japanese)

The purpose of this study was to analyze the microstructure of lath martensite in 0.1C–1.1Si–1.7Mn (wt.%) steel and its effect on mechanical properties and fracture behavior. The microstructure was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and electron back scattering diffraction (EBSD). Charpy V-notch impact samples and compact tension (CT) samples were used to investigate the Charpy impact properties and fatigue crack growth behavior of the steel, respectively. The propagation of cleavage crack and fatigue crack were analyzed to figure out the effective grain size. The results showed that the typical hierarchical lath martensite structure contained prior austenite grains, packets, blocks and laths; packet size and block width were positively correlated to prior austenite grain size, while lath width was maintained at about 0.29 μm. Yield strength was related to prior austenite grain size, packet size and block width, and obeyed Hall–Petch relationship. Grain refinement was effective in improving the resistance to cleavage fracture by introducing barriers to crack propagation; packet boundaries and block boundaries hold similar ability to impede the propagation of crack. Paris model can well describe the FCG behavior of the investigated steel. Block width governs the effective grain size for strength, toughness and fatigue crack propagation.

Application of Fractal Mathematics to Soil Water Retention Estimation

AbstractIn this paper, we present an analysis correlating the fitting parameter α in the Arya and Paris (1981) soil water retention model to physical properties of the soil. Fractal mathematics are used to show that α is equal to the fractal dimension of the pore trace and expresses a measure of the tortuosity of the pore trace. The fractal dimension of the particle‐size distribution can be easily measured and related to the α parameter of the Arya and Paris model. By suggesting a physical significance of the coefficient, the universality of the model is greatly improved. Soil water retention data, estimated strictly from particle‐size distributions, are proven to match measured data quite well. The fractal dimension of pore traces range from 1.011 to 1.485 for all but one soil tested.

Comparison of a Laboratory Procedure and a Textural Model for Predicting In Situ Soil Water Retention

AbstractA physico‐empirical model proposed by L.M. Arya and J.F. Paris in 1981 for predicting the soil moisture characteristic curve using particle size and bulk density data was compared with a commonly used laboratory method using undisturbed core samples and a pressure plate extractor, for precision in estimating in situ water retention measured with paired neutron probe and tensiometer installations. An empirical factor for the Arya and Paris (A&P) model was found to average close to the value (α = 1.38) proposed by its authors. Values for this experiment were different between texture classes. Loam and silt loam values were constant, while values for soils of sand, loamy sand, and sandy loam texture were nonconstant. The empirical factor was calibrated for (i) loam and coarse loam; (ii) silt loam; and (iii) sand, loamy sand, and sandy loam texture groups. The sandy soil values required linear calibration as a function of soil water potential. Results for the calibrated A&P model compared well, overall, with laboratory determinations on soils ranging in texture from sand to loam and silt loam. Laboratory estimates were slightly better for A and B horizon materials, while A&P estimates were better for C horizons. Error for estimation of field volumetric water content using A&P and lab methods was approximately twice the error for estimation of θ using a second field neutron‐tensiometer installation within one meter of the first field apparatus.

The origins of the psychological experiment as a social institution.

The psychological experiment involves a set of institutionalized role patterns that have evolved historically. This evolution can be studied by analyzing published experimental reports. From the beginning, there were two models for the social structure of the psychological experiment, the Leipzig and the Paris model. The latter emerged in the context of work on experimental hypnosis and in- volved a rigid social differentiation between experi- menter and subject. By contrast, the Leipzig model involved the interchangeability of experimenter and subject roles. American investigators adopted both these models but also introduced more impersonal and less intensive relations between experimenters and subjects. Some implications of the multimodal origins of experimental situations are discussed. Whatever else it may be, the psychological experi- ment is clearly a social institution that has flourished in certain societies and that implies patterns of social regulations that closely circumscribe the relationships of those who participate in it. The investigative situations in which knowledge about human psy- chology is gathered are highly institutionalized and involve a generally accepted distribution of role expectations among the participants, a clearly un- derstood status differential, and an elaborate set of rules governing the permissible interactions among the role incumbents. The sizable literature devoted to various aspects of the social psychology of the psychological exper- iment (e.g., Adair, 1973; Jung, 1982; Rosenthal & Rosnow, 1975; Silverman, 1977) has paid virtually no attention to the history of the social features of the psychological experiment. Apart from Schultz's (1970) recognition of the fact that there is a history to the use of human subjects in psychological re- search, there has been no systematic attempt to uncover this history. Because the rules of scientific experimentation prescribe the preparation of a formal account of the proceedings for publication, the literature in psycho- logical journals contains much material that throws light on historically changing social practices. Of course, published experimental articles mainly con-