14 research outputs found
Reconstruction of Tesla micro-valve using topological sensitivity analysis
In this paper, we deal with topology optimization attributed to the non stationary Navier-Stokes equations. We propose an approach where we analyze the sensitivity of a shape function relating to a perturbation of the flow domain. A numerical optimization algorithm based on topological gradient method is built and applied to the 2D Tesla micro valve reconstruction. Some numerical results confirm the efficiency of the proposed approach
Level Structure of S of Astrophysical Importance in the Reaction P()S
International audienceLevel structure of the proton-unbound 30S states, just above the proton threshold 4394.9(7) keV, is important to understand the αp and rp processes, as it plays a crucial role in the calculation of the 26Si(α, p) and 29P(p, γ) reaction rates. The spin-parity assignments of 30S strongly determine the thermonuclear 29P(p, γ) 30S reaction rate at temperatures characteristic of explosive hydrogen burning in classical novae and type I X-ray bursts. Specifically, the rate had been previously predicted to be dominated by two low-lying, levels in the Ex = 4.7–4.8 MeV region, with spin and parity assignments of 3+ and 2+. Several experiments were performed to study the structure of 30S. The 30S Jπ values were inferred from also a comparison to the known decay schemes of the corresponding mirror states in 30Si. We present, in this paper, results for levels in 30S that are used for the 29P(p, γ) rp reaction rate calculation. The positive- and negative- parity states have been calculated using the (0+1)~ω PSDPF interaction, which is charge-independent Hamiltonian. The γ-decay lifetimes of 30S and reduced electromagnetic transition strengths were also calculated. Based on experimental information on the 30S energy spectrum as well as a comparison to the T = 1 isobaric analogue states in 30Si and 30P, the levels of excited states that are used to determine the 29P(p, γ) 30S reaction rate are proposed
Determination of Methadone in Biological Samples Using Liquid Phase Microextraction with Back Extraction Combined with LC
A global look at time : a 24-country study of the equivalence of the Zimbardo Time Perspective Inventory
In this article, we assess the structural equivalence of the Zimbardo Time Perspective Inventory (ZTPI) across 26 samples from 24 countries (N = 12,200). The ZTPI is proven to be a valid and reliable index of individual differences in time perspective across five temporal categories: Past Negative, Past Positive, Present Fatalistic, Present Hedonistic, and Future. We obtained evidence for invariance of 36 items (out of 56) and also the five-factor structure of ZTPI across 23 countries. The short ZTPI scales are reliable for country-level analysis, whereas we recommend the use of the full scales for individual-level analysis. The short version of ZTPI will further promote integration of research in the time perspective domain in relation to many different psycho-social processes
Association of creatin kinase B and peroxiredoxin 2 expression with age and embryo quality in cumulus cells
The purpose of this study was to identify age-related oocyte or embryo markers suitable for non-invasive analysis, as women over 38 years of age experience diminished pregnancy and ovulation rates. We used real-time quantitative PCR to examine the gene expression profiles in cumulus cells acquired from older and younger age groups. We selected 11 genes involved in three functions that directly affect cellular aging: cell cycle control, apoptosis, and metabolism. CKB and PRDX2 were up-regulated in women older than 38 years, and the expression of these genes in cumulus cells was associated with embryo quality. In good-quality embryos, CKB expression was higher in the cumulus cells acquired from both older and younger age groups than in poor-quality embryos. These potential relationships among cumulus cell gene expression, oocyte quality, and age may expand our understanding of oogenesis and embryo development. CKB and PRDX2 may serve as biomarkers or therapeutic targets for the developmental potential of oocytes