Flow-based approach for holistic factory engineering and design

The engineering of future factories requires digital tools along life cycle phases from investment planning to ramp-up. Manufacturers need scientific-based integrated highly dynamic data management systems for the participative and integrated factory planning. The paper presents a new approach for the continuously integrated product design, factory and process planning, through a service-oriented architecture for the implementation of digital factory tools. A first prototype of the digital factory framework has been realised by a comprehensive scenario for factory, equipment and process planning. The phases of factory operation and equipment maintenance are integrated, as well. The enabling technologies, grid computing and workflow management, which supports the comprehensive and integrated engineering of products, factory and processes are shortly introduced

An energetic approach in thermomechanical fatigue for silicium molybden cast iron

The purpose of this paper is to define a low cycle fatigue criterion in order to predict the failure of engineering structures. The major problem in defining a predictive fatigue criterion is that it should be applicable for structures submitted to complex multiaxial thermo-mechanical loadings but should be identifiable from simple experiments on specimens. After a short critical review of the principal criteria used in low cycle fatigue it will be shown that the dissipated energy per cycle permits a correlation of isothermal and anisothermal results obtained on silicon molybdenum cast iron in the case of specimens and also on structures

THE PRODUCTIVITY OF SOME WHEAT VARIETIES IN THE SOIL AND CLIME CONDITIONS FROM SOUTH-WESTERN ZONE OF MEHEDINTI COUNTY

The researches aimed the comparative study of some winter wheat varieties in conventional cropping system in the conditions of reddish preluvosoil from Vanju Mare, on a 400 ha surface for a better knowing of their features in order to recommend them for cropping. During two years (2016 – 2017) there have been cropped the following wheat crop kinds: Glossa – romanian variety and two austrian varieties: Balaton and Astardo.Regarding the yield obtained by Glossa variety, it recorded an average of 6.100 kg/ha and Balaton and Astardo varieties, an average yield of 7200 kg/ha. The high yield recorded by austrian varieties is due to the fact that they belong to Premium group, very productive, very tolerant to drought and with high ecological plasticity, with good winter resistance, high tillering capacity, highly receptive to fertilizers and superior as quality. The biologic potential is very high, reaching 11.000 kg/ha. The protein content of the wheat grain depends on the following factors: the variety, the cropping technology (irrigation, fertilization) and the soil and clime conditions. Good protein content determines a good baking quality. Among the technological factors, the fertilization is the most important that increases the protein content of the wheat kernels. The wet gluten content and the falling index are favorably influenced by the nitrogen fertilizer applying. There is recommended the cropping of wheat varieties that have a high production capacity, with a good resistance to the main risk factors of the clime, with tolerance to the main foliar diseases, with superior quality indicators from different maturity classes

Asymptotic results for renewal risk models with risky investments

We consider a renewal jump-diffusion process, more specifically a renewal insurance risk model with investments in a stock whose price is modeled by a geometric Brownian motion. Using Laplace transforms and regular variation theory, we introduce a transparent and unifying analytic method for investigating the asymptotic behavior of ruin probabilities and related quantities, in models with light- or heavy-tailed jumps, whenever the distribution of the time between jumps has rational Laplace transform

Sonographic Wrist Measurements and Detection of Anatomical Features in Carpal Tunnel Syndrome

INTRODUCTION: This study compares anatomical findings at wrist level in patients with known carpal tunnel syndrome (CTS) and controls by ultrasonography (US). MATERIAL AND METHODS: Wrist-US investigations of 28 consecutive patients with 38 diagnosed, idiopathic CTS were compared to 49 healthy volunteers without history of CTS. Internal wrists dimensions, the presence of flexor muscle bellies in the carpal tunnel, and cross-sectional area of the median nerve were analyzed. The findings were correlated to gender, age, and BMI. RESULTS: US demonstrated a square internal carpal tunnel configuration in CTS patients compared to controls (P < 0.001). Patients with CTS showed a trend towards the presence of flexor muscles bellies in the carpal tunnel (odds ratio 1.77, 95% CI 0.337-8.33). CTS was present in women with higher BMI (P = 0.015). CONCLUSION: US allowed detection of specific anatomical features at wrist level in CTS patients. This observation may enable--following confirmation in larger prospective studies--risk evaluation for CTS development

Thomas-Fermi Calculations of Atoms and Matter in Magnetic Neutron Stars II: Finite Temperature Effects

We present numerical calculations of the equation of state for dense matter in high magnetic fields, using a temperature dependent Thomas-Fermi theory with a magnetic field that takes all Landau levels into account. Free energies for atoms and matter are also calculated as well as profiles of the electron density as a function of distance from the atomic nucleus for representative values of the magnetic field strength, total matter density, and temperature. The Landau shell structure, which is so prominent in cold dense matter in high magnetic fields, is still clearly present at finite temperature as long as it is less than approximately one tenth of the cyclotron energy. This structure is reflected in an oscillatory behaviour of the equation of state and other thermodynamic properties of dense matter and hence also in profiles of the density and pressure as functions of depth in the surface layers of magnetic neutron stars. These oscillations are completely smoothed out by thermal effects at temperatures of the order of the cyclotron energy or higher.Comment: 37 pages, 17 figures included, submitted to Ap

Optical alignment and spinning of laser-trapped microscopic particles

Light-induced rotation of absorbing microscopic particles by transfer of angular momentum from light to the material raises the possibility of optically driven micromachines. The phenomenon has been observed using elliptically polarized laser beams or beams with helical phase structure. But it is difficult to develop high power in such experiments because of overheating and unwanted axial forces, limiting the achievable rotation rates to a few hertz. This problem can in principle be overcome by using transparent particles, transferring angular momentum by a mechanism first observed by Beth in 1936, when he reported a tiny torque developed in a quartz waveplate due to the change in polarization of transmitted light. Here we show that an optical torque can be induced on microscopic birefringent particles of calcite held by optical tweezers. Depending on the polarization of the incident beam, the particles either become aligned with the plane of polarization (and thus can be rotated through specified angles) or spin with constant rotation frequency. Because these microscopic particles are transparent, they can be held in three-dimensional optical traps at very high power without heating. We have observed rotation rates in excess of 350 Hz.Comment: 4 pages, 4 figure

Effect of sting size on the wake of a sphere at subcritical Reynolds numbers

Vortex shedding and turbulent motion in the wake of a sphere that is supported using a streamwise-aligned cylindrical sting are investigated at a subcritical Reynolds number of Re=3800, using high speed particle image velocimetry. The mechanism by which the presence of a sting of increasing diameter relative to the diameter of the sphere influences the wake, in terms of both the small-scale shear instability and the larger wake instability, is explored and brie y compared with the two-dimensional analog of the splitter plate introduced into a cylinder wake. The difficulties associated with obtaining converged statistics, along with the effect of free stream turbulence and sphere vibrations are detailed. An understanding of the mechanism by which the blockage, or interference, arising from the presence of the sting influences cross-wake communication and downstream development is a necessary precursor to studies of active control of the wake using surface actuation on a sting-mounted sphere

Concomitant endocarditis and spondylodiscitis due to coagulase-negative Staphylococci and a review of the literature

Background: Coagulase-negative staphylococci (CoNS) are part of the normal skin flora. Although CoNS are generally considered as low pathogenic microorganisms, they can cause serious infections, particularly in the context of foreign body material. Case report: Here we present two cases of concomitant infectious endocarditis and spondylodiscitis; one caused by S. epidermidis, the other by S. haemolyticus. Additionally, we reviewed the literature for previously reported cases of concomitant endocarditis and spondylodiscitis due to CoNS. Conclusion: In patients with back pain and a cardiac device in situ, CoNS should be considered as causative pathogens for possible endocarditis and/or spondylodiscitis, and should not be regarded as contamination.</p

The strange physics of low frequency mirror mode turbulence in the high temperature plasma of the magnetosheath

International audienceMirror mode turbulence is the lowest frequency perpendicular magnetic excitation in magnetized plasma proposed already about half a century ago by Rudakov and Sagdeev (1958) and Chandrasekhar et al. (1958) from fluid theory. Its experimental verification required a relatively long time. It was early recognized that mirror modes for being excited require a transverse pressure (or temperature) anisotropy. In principle mirror modes are some version of slow mode waves. Fluid theory, however, does not give a correct physical picture of the mirror mode. The linear infinitesimally small amplitude physics is described correctly only by including the full kinetic theory and is modified by existing spatial gradients of the plasma parameters which attribute a small finite frequency to the mode. In addition, the mode is propagating only very slowly in plasma such that convective transport is the main cause of flow in it. As the lowest frequency mode it can be expected that mirror modes serve as one of the dominant energy inputs into plasma. This is however true only when the mode grows to large amplitude leaving the linear stage. At such low frequencies, on the other hand, quasilinear theory does not apply as a valid saturation mechanism. Probably the dominant processes are related to the generation of gradients in the plasma which serve as the cause of drift modes thus transferring energy to shorter wavelength propagating waves of higher nonzero frequency. This kind of theory has not yet been developed as it has not yet been understood why mirror modes in spite of their slow growth rate usually are of very large amplitudes indeed of the order of |B/B0|2~O(1). It is thus highly reasonable to assume that mirror modes are instrumental for the development of stationary turbulence in high temperature plasma. Moreover, since the magnetic field in mirror turbulence forms extended though slightly oblique magnetic bottles, low parallel energy particles can be trapped in mirror modes and redistribute energy (cf. for instance, Chisham et al. 1998). Such trapped electrons excite banded whistler wave emission known under the name of lion roars and indicating that the mirror modes contain a trapped particle component while leading to the splitting of particle distributions (see Baumjohann et al., 1999) into trapped and passing particles. The most amazing fact about mirror modes is, however, that they evolve in the practically fully collisionless regime of high temperature plasma where it is on thermodynamic reasons entirely impossible to expel any magnetic field from the plasma. The fact that magnetic fields are indeed locally extracted makes mirror modes similar to "superconducting" structures in matter as known only at extremely low temperatures. Of course, microscopic quantum effects do not play a role in mirror modes. However, it seems that all mirror structures have typical scales of the order of the ion inertial length which implies that mirrors evolve in a regime where the transverse ion and electron motions decouple. In this case the Hall kinetics comes into play. We estimate that in the marginally stationary nonlinear state of the evolution of mirror modes the modes become stretched along the magnetic field with k||=0 and that a small number the order of a few percent of the particle density is responsible only for the screening of the field from the interior of the mirror bubbles