A new creep model directly using tabulated test data and implemented in ansys

Nowadays plastics are increasingly used in highly stressed structures in all kinds of constructions. The time dependency, the so-called viscosity, is a crucial part of the material behavior of plastics. A typical form of viscosity is creep. Creep is the increase of deformation under constant load. In the FE-simulation creep behavior is usually described by creep law functions. The commercial software provide many creep law functions depending on time, stress, strain, temperature and multiple material parameters. To run a creep simulation, the user must define all the parameters which requires a certain effort. Curve-fitting procedures might be of help, the results, however, often are not precise enough. For these reasons, we introduce our new creep model doing the similar job as the creep law functions but being able to directly use the tabulated data of the creep tests without curve-fitting procedures. In this paper, we use the model to create a 3D stress-creep strain-time surface based on the tabulated data like isochronous curves, which is represented by bicubically blended Coons patches to provide a good convergence due to their differentiability. This creep model supports strain hardening, which shows more realistic behavior when the load changes significantly during the simulated proces

A multi-protein receptor-ligand complex underlies combinatorial dendrite guidance choices in C. elegans.

Ligand receptor interactions instruct axon guidance during development. How dendrites are guided to specific targets is less understood. The C. elegans PVD sensory neuron innervates muscle-skin interface with its elaborate dendritic branches. Here, we found that LECT-2, the ortholog of leukocyte cell-derived chemotaxin-2 (LECT2), is secreted from the muscles and required for muscle innervation by PVD. Mosaic analyses showed that LECT-2 acted locally to guide the growth of terminal branches. Ectopic expression of LECT-2 from seam cells is sufficient to redirect the PVD dendrites onto seam cells. LECT-2 functions in a multi-protein receptor-ligand complex that also contains two transmembrane ligands on the skin, SAX-7/L1CAM and MNR-1, and the neuronal transmembrane receptor DMA-1. LECT-2 greatly enhances the binding between SAX-7, MNR-1 and DMA-1. The activation of DMA-1 strictly requires all three ligands, which establishes a combinatorial code to precisely target and pattern dendritic arbors

Scalar Gravity and Higgs Mechanism

The role that the auxiliary scalar field $\phi$ played in Brans-Dicke cosmology is discussed. If a constant vacuum energy is assumed to be the origin of dark energy, then the corresponding density parameter would be a quantity varying with $\phi$; and almost all of the fundamental components of our universe can be unified into the dynamical equation for $\phi$. As a generalization of Brans-Dicke theory, we propose a new gravity theory with a complex scalar field $\phi$ which is coupled to the cosmological curvature scalar. Through such a coupling, the Higgs mechanism is naturally incorporated into the evolution of the universe, and a running density of the field vacuum energy is obtained which may release the particle standard model from the rigorous cosmological constant problem in some sense. Our model predicts a running mass scale of the fundamental particles in which the gauge symmetry breaks spontaneously. The running speed of the mass scale in our case could survive all existing experiments.Comment: 6 page

A note on the connection between nonextensive entropy and hh-derivative

In order to study as a whole the major part of entropy measures, we introduce a two-parameter non-extensive entropic form with respect to the \textit{h}-derivative which generalizes the conventional Newton-Leibniz calculus. This new entropy, $S_{h,h'}$, is proved to describe the non-extensive systems and recover several types of the well-known non-extensive entropic expressions, such as the Tsallis entropy, the Abe entropy, the Shafee entropy, the Kaniadakis entropy and even the classical Boltzmann\,--\,Gibbs one. As a generalized entropy, its corresponding properties are also analyzed.Comment: 6 pages, 1 figur

Time Series Analysis For Effect Of Vaccines On Pneumonia Or Gastrointestinal Disorders In Brazil

It is important for public health professionals to understand the effects of vaccine introduction and compare different types of vaccinations. This study will focus on understanding the pre and post vaccination effects of two different infectious diseases: pneumonia and gastrointestinal disorders. One of approaches of getting the accurate estimate of vaccine impact is by comparing rates or trends of the targeted disease in the years after introduction with rates of trend in the year before introduction using a time-series analysis. Specifically, in this study, the synthetic controls method implements an approach to estimating the causal effect of a designed intervention on a time series. With this new approach, potential comparison time series are combined into a composite and are used to generate a counterfactual estimate, which can be compared with the time series of interest, which are effect of vaccines on pneumonia or gastrointestinal disorders after the intervention. After conducting time series analysis on five different regions of Brazil and in national level, this study finds that the introduction of pneumonia vaccine in five regions of Brazil results in a significant increasing in case prevented and decreasing in observed cases compared to synthetic control estimated cases. However, unlike pneumonia vaccine, introduction of gastrointestinal disorder vaccine is not significantly effective for certain region of Brazil in both age groups

Biological hot spots and the accumulation of marine dissolved organic matter in a highly productive ocean margin

Concentrations of dissolved organic carbon (DOC) and major biochemicals (amino acids and carbohydrates) were measured during five cruises (2009–2010) to the Louisiana margin in the northern Gulf of Mexico. Concentrations of amino acids and carbohydrates were elevated at mid-salinities and were indicative of plankton production of dissolved organic matter (DOM) in surface waters. Hot spots of two compositionally distinct types of labile DOM were identified based on the relative abundances of amino acids and carbohydrates. Amino acid-rich hot spots occurred sporadically in regions of high phytoplankton biomass and were mostly observed between dusk and dawn, reflecting a grazing source. In contrast, carbohydrate-rich hot spots were more widespread and were often found in nutrient-poor waters, indicating the production of carbon-rich DOM associated with nutrient limitation. Major biochemical indicators and bioassay experiments indicated labile DOM comprised a relatively small fraction of the DOC. Most DOM was degraded and had a semi-labile nature. Substantial accumulations of marine (plankton-derived) DOC were observed in surface waters, particularly at mid-salinities during the summer. Microbial alteration of marine DOC and nutrient limitation of microbial utilization of carbon-rich DOM appeared largely responsible for the accumulation of DOC. The reservoir of accumulated marine DOC in the shelf surface mixed layer ranged from 0.11 Tg C to 0.23 Tg C, with the lowest and highest values occurring during winter and summer. Substantial cross-shelf export of semi-labile marine DOM occurred during the summer and provided a major carbon and energy subsidy to microbial food webs in offshore waters.We are grateful to Steven E. Lohrenz and Wei-Jun Cai for providing the opportunity to participate in the GulfCarbon cruises. We appreciate the sampling assistance by Leanne Powers and the crews of the R/V Cape Hatteras and the R/V Hugh Sharp. We thank the anonymous reviewers for their comments and suggestions. This research was funded by a grant from the U.S. National Science Foundation (0850653 to RB) and by the 111 Project of China (B13030 to SKL). (0850653 - U.S. National Science Foundation; B13030 - 111 Project of China

Link between K-absorption edges and thermodynamic properties of warm-dense plasmas established by improved first-principles method

A precise calculation that translates shifts of X-ray K-absorption edges to variations of thermodynamic properties allows quantitative characterization of interior thermodynamic properties of warm dense plasmas by X-ray absorption techniques, which provides essential information for inertial confinement fusion and other astrophysical applications. We show that this interpretation can be achieved through an improved first-principles method. Our calculation shows that the shift of K-edges exhibits selective sensitivity to thermal parameters and thus would be a suitable temperature index to warm dense plasmas. We also show with a simple model that the shift of K-edges can be used to detect inhomogeneity inside warm dense plasmas when combined with other experimental tools