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Polymer nanocomposites find diverse applications in the aerospace, automobile and electronic industries due to good corrosion resistance, high specific strength and excellent processing ability. However, the production of complex and larger parts typically requires welding technology. In this research, fused filament fabrication technique was used to prepare polypropylene nanocomposite reinforced with graphene nanoplates. The polypropylene/graphene nanocomposites were then joined using the friction stir welding. Afterward, different analyses such as thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy, tensile testing and hardness testing were applied to examine the effects of the process parameters on the microstructure and mechanical properties of the nanocomposite. The results of thermal analysis indicated that the addition of graphene nanoplates improved the melting point and crystallinity percentage of the polypropylene nanocomposite. Mechanical characterization of the welded samples indicated that the increase of rotational speed from 500 to 750 rpm enhanced the tensile strength of weld joint, while it reduced the hardness. Moreover, an increase in the welding speed from 10 to 30 mm/min resulted in a reduction in the tensile strength and an improvement in the hardness. The highest tensile strength of the weld was obtained by addition of 1 wt% graphene to polypropylene, whereas the hardness of the weld was maximized by addition of 2 wt% graphene. Nevertheless, the desirable combination of the process parameters for simultaneous enhancement of tensile strength and hardness was achieved by rotational speed of 667 rpm, welding speed of 16 mm/min and graphene content of 1.5 wt%.

ESA’s PLATO mission aims the detection and characterization of terrestrial planets around solar-type stars as well as the study of host star properties. The noise-to-signal ratio (NSR) is the main performance parameter of the PLATO instrument, which consists of 24 Normal Cameras and 2 Fast Cameras. In order to justify, verify and breakdown NSR-relevant requirements the software simulator PINE was developed. PINE models the signal pathway from a target star to the digital output of a camera based on physical models and considers the major noise contributors. In this paper, the simulator’s coarse mode is introduced which allows fast performance analyses on instrument level. The added value of PINE is illustrated by exemplary applications.

In recent years, escalating cost of generating electricity, substantial investments with the purpose of building power plants, and environmental pollution related to the power generation have underlined the importance of optimal power supply and demand management. Given that, by employing Long-range Energy Alternatives Planning (LEAP) software, the present study set out to optimize the energy system of Iran through two model capabilities, namely electric sector optimization and simulation. To do so, the energy system was initially evaluated by optimizing Iran's demand for electricity by the Demand Side Management (DSM) scenario. Then, Iran's electricity sector was optimized to generate electricity at the lowest cost by setting emission roof with different scenarios, especially the Optimized scenario. The social cost and GHG emission were evaluated in both steps. The prospective social costs of the electricity generation sector based on Optimized and DSM scenarios were calculated to be 5.1 and 4.8 Billion U.S. Dollars in 2035. Regarding the environmental results of the study, the emission rates of pollutants based on Optimized and DSM scenarios were reported to be144 and 429 $${\mathrm{MtCO}}_{2}$$ for the same year.

Grouping of earthquakes into distinct clusters is applied to improve mechanism identification and pattern recognition for active seismicity in a region. One of the important issues concerning earthquake data clustering is determining the optimum number of clusters (ONC) at the early stages of algorithms. In this paper a robust method based on K-nearest neighbor search (KNNS) is presented to achieve three goals: improving output accuracy, improving output stability, and adding the ability to weight the features used in ONC determination. By introducing a new formula, the proposed method utilizes the error calculated for clustered data based on the similarity between the members in each cluster. An outlier attenuation algorithm is also used to improve the performance of the method. Both the Krzanowski–Lai Index (KLI) and the silhouette coefficient (SC), as two conventional methods, were used to compare the results and evaluate the performance. Experiments on synthetic data sets verified the effectiveness of the method, with considerable differences found. The clustering of a real earthquake catalogue related to the seismogenic province of Zagros in Persia using our proposed methodology suggests using 13-cluster analysis for clustering based on the spatiotemporal features with the same weights, and seven-cluster analysis for a case where priority is given only to the spatial parameters of the epicenters. Under the same circumstances, the KLI and SC methods suggest three and 18 clusters, respectively. The results of the experiments on synthetic data sets indicate that the proposed method is quantitatively more stable and more accurate than the other two methods.

We evaluate the frequency difference between standard stellar models and models patched with 3D hydrodynamical models across the Teff–g plane. It allows us to constrain frequency corrections for surface effect. The coefficients in the correction functionals are thus provided as functions of effective temperature and surface gravity.

Friction stir welding as one of the modern methods of solid-state welding of steel sheets and aluminum is a highly regarded industry. In these studies, the experimental design and response surface methodology were used. Optimization of experimental conditions and results which are compared with good agreement between the results was observed. The mechanical properties and ductility of welded plates under optimal conditions were studied. Microhardness testing, metallography, tensile testing, and limiting dome height were used to investigate the mechanical properties and formability limit diagram attached, respectively. The results showed that the heat-affected zone is very small and narrow and not easily distinguished from the base metal. In all tests, the failure of the dome height limit in the area was chaos. In all samples welded with the optimal parameters, tensile failure occurred in the base metal region. Turbulence in the region confirms the presence of WC particles. Experimental design and response surface methodology could introduce an optimal state, and the creation of common defects in the FSW process can prevent the binding strength of the guarantee. But due to the lack of proper stirring in the perturbation area in the samples welded with non-optimized parameters, the strength of the connection is not suitable, and samples were broken from the SZ region.

The development of space-borne missions has significantly improved the quality of the measured spectra of solar-like oscillators. Their $p$-mode line profiles can now be resolved, and the asymmetries inferred for a variety of stars other than the Sun. However, it has been known for a long time that the asymmetries of solar $p$-modes are reversed between the velocity and the intensity spectra. Understanding the origin of this reversal is necessary in order to use asymmetries as a tool for seismic diagnosis. For stars other than the Sun, only the intensity power spectrum is sufficiently resolved to allow for an estimation of mode asymmetries. We recently developed an approach designed to model and predict these asymmetries in the velocity power spectrum of the Sun and to successfully compare them to their observationally derived counterparts. In this paper we expand our model and predict the asymmetries featured in the intensity power spectrum. We find that the shape of the mode line profiles in intensity is largely dependent on how the oscillation-induced variations of the radiative flux are treated, and that modelling it realistically is crucial to understanding asymmetry reversal. Perturbing a solar-calibrated grey atmosphere model, and adopting the quasi-adiabatic framework as a first step, we reproduce the asymmetries observed in the solar intensity spectrum for low-frequency modes. We conclude that, unlike previously thought, it is not necessary to invoke an additional mechanism (e.g. non-adiabatic effects, coherent non-resonant background signal) to explain asymmetry reversal. This additional mechanism is necessary, however, to explain asymmetry reversal for higher-order modes., Comment: 9 pages, 4 figures. Accepted for publication in A&A

Measuring the stellar rotation of one of the components in eclipsing binaries (EBs) or planetary systems is a challenging task. The difficulty is mainly due to the complexity of analyzing, in the same light curve, the signal from the stellar rotation mixed with the transit signal of a stellar or sub-stellar companion, like a brown dwarf or planet. There are many methods to correct the long-term trend of the light curve. However, the correction often erases the signal of the stellar rotation from spots crossing the visible stellar disk and other weaker signals like planets. In this work, we present the DiffeRencial flUx Method of cuTting Off biNariES (DRUM TONES) to identify the signal of the binary transits and disentangle it from stellar rotation planet signals. We present our technique with applications to EBs from CoRoT, Kepler, Kepler K2 and TESS missions. We also applied our method to simulated synthetic EB from the PLATO mission. Our method shows good agreement in the determination of stellar rotation periods for few observed targets from last space missions, as well it is naturally useful for future European missions, such as PLAnetary Transits and Oscillations of stars (PLATO)., 21 pages, 10 figures, accepted to be published on The Experimental Astronomy (May 14, 2020)

In this paper, we aim to develop a predictive model for solar radial $p$-mode line profiles in the velocity spectrum. Unlike the approach favoured by prior studies, this model is not described by free parameters and we do not use fitting procedures to match the observations. Instead, we use an analytical turbulence model coupled with constraints extracted from a 3D hydrodynamic simulation of the solar atmosphere. We then compare the resulting asymmetries with their observationally derived counterpart. We find that stochastic excitation localised beneath the mode upper turning point generates negative asymmetry for $\nu < \nu_\text{max}$ and positive asymmetry for $\nu > \nu_\text{max}$. On the other hand, stochastic excitation localised above this limit generates negative asymmetry throughout the $p$-mode spectrum. As a result of the spatial extent of the source of excitation, both cases play a role in the total observed asymmetries. By taking this spatial extent into account and using a realistic description of the spectrum of turbulent kinetic energy, both a qualitative and quantitative agreement can be found with solar observations perfoemed by the GONG network. We also find that the impact of the correlation between acoustic noise and oscillation is negligible for mode asymmetry in the velocity spectrum., Comment: 26 pages (19 without appendices), 14 figures. Accepted for publication in A&A

This research aimed to investigate the role of socio-economic variables on the prices of land and housing in the city of Mashhad. From the results of the measured socio-economic variables of citizens, the highest coefficient was obtained by districts 1 and 9, while districts 5 and 3 had the lowest value. The existence of a positive and direct relationship between socio-economic variables of the residents and land and housing prices, and the significance of the test (at the level of 95%) were approved. The results of the impact of socio-economic variables on land and housing prices, using path analysis, showed that the variables of income, occupational status, and educational level had the highest effect on the price of land and housing, while variables of family size and history of residence had the lowest impact on the price. Furthermore, the coefficient of determination (0.780) obtained from path analysis diagram showed that 78% of the total changes of the dependent variable (the price of land and housing) were explained by the analytical model.

Despite the vital role of electricity in human life, the energy supply process produces all kinds of pollutants such as solid wastes. Unfortunately, due to the lack of specific charge of administration, lack of legal and statutory criteria for effective control, and lack of supervising organizations, in Iran the industrial wastes couldn’t be managed well. The quantity and quality of waste of power plants have been investigated, and then a questionnaire was sent to all stations. The results showed that the use of Mazut fuel and gas oil will increase the rate of wastes. In thermal-gas power plants, due to the consumption of natural gas and lack of water consumption in the production cycle, less wastes have been produced than the other thermal power plants. To determine and explain the factors affecting the production of waste in power plants, an interview was held in the presence of 40 experts in the field of power plant wastes, and after determining the factors affecting the rate of wastes in power...

Nowadays, oil platform's moorings failure one of the most important challenges of the drilling industry in deep seas for the establishment and stability of the platform during operation. The behavior of these moorings plays an important role in the preservation of the platform with interaction by waves and environmental forces. In this regard a sample of non-classical Spar Truss platform was analyzed using Moses software in the Caspian Sea. Also hydrodynamic analysis of mooring system based on three-dimensional diffraction method was used; this analysis is based on time dependent and six degrees of freedom motion. Therefore response amplitude operator (RAO) of platform moorings was obtained by incident wave. The effect of removing a platform mooring was studied. The results indicate a high gradient change in Surge Movement. Also the results of this study can be used as a benchmark for spar platforms design in Caspian sea.

The research hereby introduces a novel approach to reduce tooth bending stress using a parametric numeric simulation. This Finite Element Method (FEM) is used to determine optimal design variables for an asymmetric root profile of a helical gear defined by a rational cubic Bezier curve. The gear is first modelled using a machine design software and later implemented into a 3D computer aided design (CAD) package to modify the root spline geometry using a script. A nonlinear relationship exists between the design variables and tooth bending stress. Additionally, certain trends exist between the design variables to exhibit a more optimal root profile. The simulation results show that the proposed method is feasible as the general optimization process results in significant bending stress reduction. The numerical simulation demonstrates that bending stress can be reduced by as much as 10.75% by the proposed approach.

Context.Space observations by the CoRoT andKeplermissions have provided a wealth of high-quality seismic data for a large number of stars from the main sequence to the red giant phases. One main goal of these missions is to take advantage of the rich spectra of solar-like oscillations to perform precise determinations of stellar characteristic parameters. To make the best of such data, we need theoretical stellar models with a precise near-surface structure since a near-surface structure of a solar-like star has significant influence on solar-like oscillation frequencies. The mixing-length parameter is a key factor to determine the near-surface structure of stellar models. In current versions of the convection formulations used in stellar evolution codes, the mixing-length parameter is a free parameter that needs to be properly specified.Aims.We aim at determining appropriate values of the mixing-length parameter,α, to be used consistently with the adopted convection formulation when computing stellar evolution models across the Hertzsprung–Russell diagram. This determination is based on 3D hydrodynamical simulation models.Methods.We calibratedαvalues by matching entropy profiles of 1D envelope models with those of hydrodynamical 3D models of solar-like stars produced by the CO5BOLD code. For such calibration, previous works concentrated on the classical mixing-length theory (MLT). We also analyzed full spectrum turbulence (FST) models. To construct the atmosphere in the 1D models, we used the Eddington grayT(τ) relation and that with the solar-calibrated Hopf-like function.Results.For both MLT and FST models with a mixing lengthl = αHp, calibratedαvalues increase with increasing surface gravity or decreasing effective temperature. For the FST models, we carried out an additional calibration using anα*value defined asl = rtop − r + α*Hp, top, whereα*is found to increase with surface gravity and effective temperature. We provide tables of the calibratedαvalues across theTeff–log g plane for solar metallicity. By computing stellar evolution with varyingαbased on our 3Dαcalibration, we find that the change from solarαto varyingαshifts evolutionary tracks particularly for the FST model. As for the correspondence to the 3D models, the solar Hopf-like function generally gives a photospheric-minimum entropy closer to a 3D model than the EddingtonT(τ). The structure below the photosphere depends on the adopted convection model. However, we cannot obtain a definitive conclusion about which convection model gives the best correspondence to the 3D models. This is because each 1D physical quantity is related via an equation of state (EoS), but it is not the case for the averaged 3D quantities. Although the FST models withl = rtop − r + α*Hp, topare found to give the oscillation frequencies closest to the solar observed frequencies, their acoustic cavities are formed with compensatory effects between deviating density and temperature profiles near the top of the convective envelope. In future work, an appropriate treatment of the top part of the 1D convective envelope is necessary, for example, by considering turbulent pressure and overshooting.

Due to the development of cities as well as rapid population growth, urban traffic is increasing nowadays. Hence, to improve traffic flow, underground structures such as metro, especially in metropolises, are inevitable. This paper is a research on the twin tunnels Of Isfahan's metro between Shariaty station and Azadi station from the North towards the South. In this study, simultaneous drilling of subway's twin tunnels is simulated by means of Finite Difference Method (FDM) and FLAC 3D software. Moreover, the lowest distance between two tunnels is determined in a way that the Law of Super Position could be utilized to manually calculate the amount of surface subsidence, resulted by drilling two tunnels, by employing the results of the analysis of single tunnels without using simultaneous examination and simulation. In this paper, this distance is called "effective distance". For this purpose, first, the optimum dimensions of the model is chosen and then, five models with optimum dimensions will be analyzed separately, each of which in three steps. The results of analyses shows that the proportions (L/D) greater than or equal 2.80, the Law of Super Position can be applied for prediction of surface subsidence, caused by twin tunnels' construction

The CoRoT and Kepler missions have provided high-quality measurements of the frequency spectra of solar-like pulsators, enabling us to probe stellar interiors with a very high degree of accuracy by comparing the observed and modeled frequencies. However, the frequencies computed with 1D models suffer from systematic errors related to the poor modeling of the uppermost layers of stars. These biases are what is commonly named the near surface effect. The dominant effect is related to the turbulent pressure that modifies the hydrostatic equilibrium and thus the frequencies. This has already been investigated using grids of 3D RMHD simulations, which also were used to constrain the parameters of the empirical correction models. However, the effect of metallicity has not been considered so far. We study the impact of metallicity on the surface effect across the HR diagram, and provide a method for accounting for it when using the empirical correction models. We computed a grid of patched 1D stellar models with the stellar evolution code CESTAM in which poorly modeled surface layers have been replaced by averaged stratification computed with the 3D RMHD code CO5BOLD. We found that metallicity has a strong impact on the surface effect: keeping T_eff and log g constant, the frequency residuals can vary by up to a factor two. Therefore, the influence of metallicity cannot be neglected. We found that a correct way of accounting for it is to consider the surface Rosseland mean opacity. It allowed us to give a physically-grounded justification as well as a scaling relation for the frequency differences at nu_max as a function of T_eff, log g and kappa. Finally, we provide prescriptions for the fitting parameters of the correction functions. We show that the impact of metallicity through the Rosseland mean opacity must be taken into account when studying and correcting the surface effect., Comment: 15 pages, 7 figures. Accepted for publication in A&A

Over the past few years, the pace of fossil fuel consumption has witnessed an accelerating trend across the world which has been really noticeable especially for the power generation sector. With regard to its global importance, the environment must be also preserved and emissions of pollutants and greenhouse gases (GHGs) as well as environmental costs need to be moderated. Given the urgency of energy preservation and environmental issues, the process of electricity generation should be evaluated. Accordingly, elimination of conditions along with prediction of energy consumption and pollutant emissions have been performed through energy simulation and modeling software tools, e.g., Long-range Energy Alternatives Planning System (LEAP). The energy consumption in thermal power plants for 2035 is estimated to be 209.7, 153.5, and 132.0 Bcm respectively for Reference (REF), Efficiency based on 5-Year National Development Plan (E5P), and Efficiency similar to UK (EUK) scenarios using efficiency improvement scenario of thermal power plants in Iran. GHG emissions for 2035 are thus predicted by 456.8 MtCO2-eq for the REF scenario, and 332.6 and 285.1 MtCO2-eq for the E5P and the EUK ones, respectively. Environmental costs for electricity generation system will also diminish via applying scenarios in this sector and its least amount, that is, US$835.8 million is related to the EUK scenario. Accomplishing goals such as better preservation of fossil resources and the environment will be consequently facilitated through improved efficiency and effectiveness of consumption of energy resources. To meet the objectives of environmental preservation, it is suggested to completely implement development plans and also make attempts to promote the technology of thermal power plants in Iran similar to that in developed countries. This study also compares the findings with those reported in recently published investigations.

Asteroseismology allows us to probe stellar interiors. Mixed modes can be used to probe the physical conditions in red giant cores. However, we still need to identify the physical mechanisms that transport angular momentum inside red giants, leading to the slow-down observed for the red giant core rotation. Thus large-scale measurements of the red giant core rotation are of prime importance to obtain tighter constraints on the efficiency of the internal angular momentum transport, and to study how this efficiency changes with stellar parameters. This work aims at identifying the components of the rotational multiplets for dipole mixed modes in a large number of red giant oscillation spectra observed by Kepler. Such identification provides us with a direct measurement of the red giant mean core rotation. We compute stretched spectra that mimic the regular pattern of pure dipole gravity modes. Mixed modes with same azimuthal order are expected to be almost equally spaced in stretched period. The departure from this regular pattern allows us to disentangle the various rotational components and therefore to determine the mean core rotation rates of red giants. We obtained mean core rotation measurements for 875 red giant branch stars. This large sample includes stars with a mass as large as 2.5 $M_{\odot}$, allowing us to test the dependence of the core slow-down rate on the stellar mass. This work on a large sample allows us to refine previous measurements of the evolution of the mean core rotation on the red giant branch. Rather than a slight slow down, our results suggest rotation to be constant along the red giant branch, with values independent on the mass., Comment: 14 pages, 14 figures, 4 tables, submitted to A&A

We have developed a new automated method intended to perform the simultaneous - and thus more consistent - measurement of both the seismic indices characterizing the oscillations and the parameters characterizing the granulation signature of red-giant stars. This method, called MLEUP, takes advantage of the Maximum Likelihood Estimate (MLE) algorithm combined with the parametrized representation of red giant pulsation spectra following the Universal Pattern (UP). Its performances have been tested on Monte Carlo simulations for observation conditions representative of CoRoT and Kepler data. These simulations allowed us to determine, calibrate and propose correction for the biases on the parameter estimates as well as on the error estimates produced with MLEUP. Finally, we applied MLEUP to CoRoT and Kepler data. In total, MLEUP yields seismic indices for 20,122 red giant stars and granulation parameters for 17,109 of them. These data have been made available in the Stellar Seismic Indices database (http://ssi.lesia.obspm.fr/)., Comment: accepted for publication in Astronomische Nachrichten, 27 pages

A leap forward has been performed due to the space-borne missions, MOST, CoRoT and Kepler. They provided a wealth of observational data, and more precisely oscillation spectra, which have been (and are still) exploited to infer the internal structure of stars. While an adiabatic approach is often sufficient to get information on the stellar equilibrium structures it is not sufficient to get a full understanding of the physics of the oscillation. Indeed, it does not permit one to answer some fundamental questions about the oscillations, such as: What are the physical mechanisms responsible for the pulsations inside stars? What determines the amplitudes? To what extent the adiabatic approximation is valid? All these questions can only be addressed by considering the energy exchanges between the oscillations and the surrounding medium. This lecture therefore aims at considering the energetical aspects of stellar pulsations with particular emphasis on the driving and damping mechanisms. To this end, the full non-adiabatic equations are introduced and thoroughly discussed. Two types of pulsation are distinguished, namely the self-excited oscillations that result from an instability and the solar-like oscillations that result from a balance between driving and damping by turbulent convection. For each type, the main physical principles are presented and illustrated using recent observations obtained with the ultra-high precision photometry space-borne missions (MOST, CoRoT and Kepler). Finally, we consider in detail the physics of scaling relations, which relates the seismic global indices with the global stellar parameters and gave birth to the development of statistical (or ensemble) asteroseismology. Indeed, several of these relations rely on the same cause: the physics of non-adiabatic oscillations., 90 pages, 36 pages, lectures notes, Ecole Evry Schatzman 2014 : asteroseismology and next generation stellar models, 28 Sep-3 Oct 2014 Roscoff (France)

In the framework of the SPACEInn project, a Stellar Seismic Indices (SSI - http://ssi.lesia.obspm.fr/) database was developed in order to provide the scientific community with oscillations and granulation signatures for a large set of red-giant type stars. For this purpose, we have developed the method MLEUP able to extract simultaneously the seismic indices (the equidistance Δv , the frequency v max and the height H env of the maximum oscillation power) and granulation parameters (the e-folding time τeff and the variance of the integrated brightness fluctuations σ2 ). This method has been tested in terms of precision and accuracy, using Monte Carlo simulations. Then we applied it to all stars observed by CoRoT and all long-cadence Kepler lightcurves. In total, we yield seismic indices and granulation parameters for about 5,000 stars for CoRoT and more than 13,000 for Kepler . In this paper, we focus on the main results for both seismic indices Δv and v max as well as for the stellar parameters (mass, radius and luminosity) seismically inferred. Then, in the perspective of Gaia, we discuss about the possibility to derive other seismic quantities like e.g. a seismic effective temperature.

Seismic observations have shown that a number of evolved stars exhibit low-amplitude dipole modes, which are referred to as depressed modes. Recently, these low amplitudes have been attributed to the presence of a strong magnetic field in the stellar core of those stars. We intend to study the properties of depressed modes in evolved stars, which is a necessary condition before concluding on the physical nature of the mechanism responsible for the reduction of the dipole mode amplitudes. We perform a thorough characterization of the global seismic parameters of depressed dipole modes and show that these modes have a mixed character. The observation of stars showing dipole mixed modes that are depressed is especially useful for deriving model-independent conclusions on the dipole mode damping. Observations prove that depressed dipole modes in red giants are not pure pressure modes but mixed modes. This result invalidates the hypothesis that the depressed dipole modes result from the suppression of the oscillation in the radiative core of the stars. Observations also show that, except for the visibility, the seismic properties of the stars with depressed modes are equivalent to those of normal stars. The mixed nature of the depressed modes in red giants and their unperturbed global seismic parameters carry strong constraints on the physical mechanism responsible for the damping of the oscillation in the core. This mechanism is able to damp the oscillation in the core but cannot fully suppress it. Moreover, it cannot modify the radiative cavity probed by the gravity component of the mixed modes. The recent mechanism involving high magnetic field proposed for explaining depressed modes is not compliant with the observations and cannot be used to infer the strength and the prevalence of high magnetic fields in red giants., accepted in A&A

The Stellar Seismic Indices database (hereafter SSI) has been developed within the SPACEInn project funded under the UE Seventh Framework Programme (FP7). This data base aims at providing stellar seismic indices of solar-like oscillating stars as well as other stellar indices such as the main characteristics of stellar granulation. These indices are extracted using an automatic method, which is able to derive simultaneously the seismic and granulation parameters. This method was applied to almost all Kepler long-cadence light-curves and to almost all CoRoT targets observed in the faint fields. A total of about 320 000 targets have been analyzed, among which seismic indices and granulation parameters have been extracted for about 18 000 redgiants. In this article, we present the data base content, its interface, as well as some illustrative results.

This paper proposes a particle-based modeling method for predicting the constitutive behavior of textiles when subjected to various compressive loading conditions. The method, which is demonstrated for stacked layers of plain woven textiles, utilizes discrete mechanics as an alternative to traditional continuum mechanics. Fibers are modeled as a series of conjoined points, and their configurations are determined mechanistically using a modified Metropolis algorithm and inter-particle strain energy terms. The implementation presented in this paper enables intricate geometric modeling of textiles at microscopic, mesoscopic and macroscopic scales. It also enables extensive mechanical modeling of the textiles, from first principles, as they are loaded upon manufacturing of typical technical textile structures. While this paper focuses on the compaction behavior of weaves, the modeling method is readily adaptable to the analysis of shear, bending, buckling, punching, relaxation and other loading scenarios applied on a wide array of different textile types. These scenarios will be demonstrated in forthcoming publications. Comparative data from in silico and in situ testing shows excellent agreement. Results demonstrate an improvement in simulation accuracy over prior comparable modeling techniques. The method presented here successfully predicts the actual behavior of yarns, single-layer and double-layer textile stacks in compaction.

Space-borne missions CoRoT and Kepler have provided a rich harvest of high-quality photometric data for solar-like pulsators. It is now possible to measure damping rates for hundreds of main-sequence and thousands of red-giant. However, among the seismic parameters, mode damping rates remain poorly understood and thus barely used for inferring the physical properties of stars. Previous approaches to model mode damping rates were based on mixing-length theory or a Reynolds-stress approach to model turbulent convection. While able to grasp the main physics of the problem, those approaches are of little help to provide quantitative estimates as well as a definitive answer on the relative contribution of each physical mechanism. Our aim is thus to assess the ability of 3D hydrodynamical simulations to infer the physical mechanisms responsible for damping of solar-like oscillations. To this end, a solar high-spatial resolution and long-duration hydrodynamical 3D simulation computed with the ANTARES code allows probing the coupling between turbulent convection and the normal modes of the simulated box. Indeed, normal modes of the simulation experience realistic driving and damping in the super-adiabatic layers of the simulation. Therefore, investigating the properties of the normal modes in the simulation provides a unique insight into the mode physics. We demonstrate that such an approach provides constraints on the solar damping rates and is able to disentangle the relative contribution related to the perturbation of the turbulent pressure, the gas pressure, the radiative flux, and the convective flux contributions. Finally, we conclude that using the normal modes of a 3D numerical simulation is possible and is potentially able to unveil the respective role of the different physical mechanisms responsible for mode damping provided the time-duration of the simulation is long enough., Accepted in A&A, 15 pages, and 13 figures

Ramsar area is located across and between Alborze Mountain and Caspine Sea in North of Iran. About 30 spas are located south of the Ramsar and Sadatshar town. They are almost in between 20 to 70 m elevation. Paleozoic, Mesozoic and Tertiary rocks and alluvial deposit are exposed around the Ramsar area. In tertiary, acidic Plutonism was active and intrusion into the Paleozoic and Cenozoic formations. Quaternary and Alluvium deposits are exposed and extending on the Jurassic formations in Ramsar plain and have thickness lower than 10 m in show springs. The annual precipitation in the Ramsar region is 976 mm. There has not any proper Thermal spring management in Ramsar area yet. This could post some serious problem on improper management of Thermal spring sites, where its environment has been put into jeopardy. This study aims to provide a way to classify the Thermal springs in Ramsar area. The result of this study help in the classification of Thermal spring sites for official planning improvement of administration and sustainable development of natural resources of the area. The study makes use of the Department of Applied Geosciences in Islamic Azad University. GIS data of a total of 9 Thermal springs in the attempt to set up a classification system of Thermal springs in Ramsar area. These data include surface temperature, conductivity, alkalinity, acidity, TDS, pH values, H2S, Ca, Cl, Fe, K, Mg, Mn, Na, SiO2, SO4 contents, their locations, usages and other relevant information. The surface temperature of Thermal springs are between 19oC – 65oC and Na-K-Cageothermometer shows estimated reservoir temperature range from 25 o C – 195 o C. Most of the water from these Thermal springs is relatively turbidness and their composition is sodium choloride. The Thermal springs in this area generally exhibit high SiO2 and Na content; strong smell of sulfur. In addition, there are 9 Thermal springs that show high concentration of Cl, Ca, Na, K and Mg. There are three major criteria used in the classification system in this study, temperature, pH and their usage. On the basis of temperature, there are three classes of Thermal springs in Ramsar area: hyper thermal spring (10 %, 50-99o C); thermal spring (80%, 30-50o C). There is one class achieved on the basis of pH values: all of Thermal springs exhibit weak acids. There are 4 types of usage classification: swimming pools, Tourism, space heating and drying of organic materials.

The most enigmatic problems with the nearly 200 salt domes pierced in the Persian Gulf and in the Zagros Mountain Ranges (ZMR) in southern Iran, a unique morphology in the world, have been the matter of this study, which is based on a combination of field work, enhancement of satellite and aerial photographs etc. In the ZMR, structural anomalies are frequently associated with similar facies distribution patterns. In the eastern portion of the region, emergent salt plugs of Infra-Cambrian age exhibit the same alignment patterns. Such trends bear no apparent genetic relationship to the Tertiary folding responsible for the present Zagros fold belt, but rather indicate their affinity with linear basement features which are readily observable on Land sat imagery and aerial photographs. Bending of anticlines in the competent cover rock, combined with minor strike-slip faults and horizontal displacements of parts of folded structures, strongly point to the presence of these basement faults. The salt plugs, which have pierced cover rocks of up to 10000 m thick, are distributed on the Arabian Platform along regional basement faults. The area of diapir outcrops is bounded by the Oman Line to the east and by the Kazerun fault to the west. Pieces of the basement have been brought up to the surface on some of the salt domes. The fragments were transported by rotational ascent of the Hormuz Salt Formation to the present and former land surfaces. The recognition of features related to basement tectonics and realization of their implication in the control and modification of geological processes are important adjuncts to the search for hydrocarbon accumulations in this region. To our best knowledge, data of basement faults in the study area are scarce. Therefore, this study was carried out to determine basement faults and their relation to salt dome distribution. Considering the fold axes bending, the trend of the salt plugs and also the distribution of epicenters of the last century, n umerous new basement faults are introduced in this paper.

CoRoT and Kepler observations of red giants reveal a large variety of spectra of nonradial solar-like oscillations. So far, we understood pretty well the link between the global properties of the star (radius, mass, evolutionary state) and the properties of the oscillation spectrum (Δν, νmax, period spacing). We are interested here in the theoretical predictions of two other components of a power spectrum, the mode linewidths and heights. The study of the energy of the oscillations is of great importance to predict the peak parameters in the power spectrum. We will discuss circumstances under which mixed modes are detectable for red-giant stellar models from 1 to 2 M⊙, with emphasis on the effect of the evolutionary status of the star along the red-giant branch on theoretical power spectra.

The CoRoT satellite is revolutionizing the photometric study of massive O-type and B-type stars. During its long runs, CoRoT observed the entire main sequence B star domain, from typical hot β Cep stars, via cooler hybrid p- and g-mode pulsators to the SPB stars near the edge of the instability strip. CoRoT lowers the sensitivity barrier from the typical mmagprecision reached from the ground, to the µ mag-level reached from space. Within the wealth of detected and identified pulsation modes, relations have been found in the form of multiplets, combination of frequencies, and frequency- and period spacings. This wealth of observational evidence is finally providing strong constraints to test current models of the internal structure and pulsations of hot stars. Aside from the expected opacity driven modes with infinite lifetime, other unexpected types of variability are detected in massive stars, such as modes of stochastic nature. The simultaneous observation of all these light curve characteristics implies a challenge for both observational asteroseismology and stellar modelling (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

This paper investigates the prediction of the constitutive behavior of textiles subjected to in-plane shear loading, using a particle-based modelling method. Plain weave textiles where the fibers are represented as a series of conjoined particles were modelled using discrete mechanics, as an alternative to traditional continuum mechanics. The configurations of individual fibers were obtained from first principles, using a modified Metropolis algorithm to minimize the strain energy terms. A series of simulations replicating articulated frame in-plane shear tests were performed in order to characterize the in-plane shear behavior of woven textiles. The paper discusses the effects of varying boundary conditions at fiber ends upon the application of a displacement field, and of varying iteration parameters for particle positions towards lower levels of strain energy. Load-displacement curves were derived from the simulations; displacement fields, locking angles and shear stresses were also quantified. The results of simulations and experiments performed on woven textiles subjected to in-plane shear showed good agreement, and improvements in accuracy over other modelling techniques.

International audience; Context: The estimate of solar-like oscillation properties, such as their frequencies, amplitudes and lifetimes, is challenging because of their low amplitudes and will benefit from long and uninterrupted observing runs. The space telescope CoRoT allows us to obtain high-performance photometric data over a long and quasi continuous period. Among its main targets are stars for which we expect solar-like oscillations. Aims: HD 181420, an F2 main sequence star, has been observed by CoRoT during its first long run covering about 156 days. With this unprecedently high-quality set of data, our aim is to derive the p-mode parameters that can be used to probe the stellar interior. Methods: The CoRoT data obtained on HD 181420 is analysed using a classical Fourier approach for the search for the p mode signature. The p-mode parameters are then derived using global fitting of the power spectrum by a Lorentzian model, as used widely in the solar case. Results: From the p-mode frequencies, the mean value of the large spacing is estimated to be 75 {mu Hz}. The p-mode amplitudes are slightly less than 4 ppm with a line width of about 8 {mu Hz} at the maximum of the p modes. The inclination angle is estimated to be around 45 °. The large mode line-width combined with the observed mode spacing make it difficult to identify the l=2 modes and to estimate the rotational splitting. We explore two scenarios for the identification of the modes.

We search for new variable B-type pulsators in the CoRoT data assembled primarily for planet detection, as part of CoRoT's Additional Programme. We aim to explore the properties of newly discovered B-type pulsators from the uninterrupted CoRoT space-based photometry and to compare them with known members of the Beta Cep and slowly pulsating B star (SPB) classes. We developed automated data analysis tools that include algorithms for jump correction, light-curve detrending, frequency detection, frequency combination search, and for frequency and period spacing searches. Besides numerous new, classical, slowly pulsating B stars, we find evidence for a new class of low-amplitude B-type pulsators between the SPB and Delta Sct instability strips, with a very broad range of frequencies and low amplitudes, as well as several slowly pulsating B stars with residual excess power at frequencies typically a factor three above their expected g-mode frequencies. The frequency data we obtained for numerous new B-type pulsators represent an appropriate starting point for further theoretical analyses of these stars, once their effective temperature, gravity, rotation velocity, and abundances will be derived spectroscopically in the framework of an ongoing FLAMES survey at the VLT., Comment: 22 pages, 30 figures, accepted for publication in A&A