Mcgeetierney8937
The compactability of an asphalt mixture is related to the heating temperature of the materials, but the heating temperature of reclaimed asphalt pavement (RAP) is limited by the production process of hot-in-plant recycled mixtures. To choose a reasonable heating temperature for RAP according to the compactability, the compaction energy ratio (CER) obtained from the Superpave gyratory compactor compaction curve was developed. The CERs of fourteen kinds of asphalt mixtures made with different RAPs were compared, all of which were different in type, content, and heating temperature. The results indicated that CER is an effective energy index to evaluate the workability of a bituminous mixture, and it considers both the accumulated energy after each gyration and the number of gyrations. It was also found that increasing the heating temperature of the RAP cannot always improve the workability of the recycled mixture, because the higher heating temperature caused more hard-aged bitumen to be blended with soft virgin bitumen during the mixing process. At the same RAP heating temperature, increasing the RAP content made it more difficult to compact the mixture, especially for RAPs with styrene-butadiene-styrene (SBS) modified bitumen, and the recycled mixtures with SBS-modified bitumen were more difficult to compact than those with nonmodified bitumen.Interference-fit riveting is one of the most widely used mechanical joining ways in aircraft assembly. The fatigue performance of riveted joints has a significant impact on the service life and reliability of aircraft. In this paper, the fatigue performance of the riveted lap joints with various rivet diameters and pitches are studied based on stress distribution analysis under tensile load. First, a theoretical model of the riveted lap joint under tensile load is developed by using the spring-mass model. The rivet-load stress, bypass stress, and interference stress around the riveted hole are analyzed. Then, the finite element (FE) model of riveted lap joints are established. The influence of rivet diameter and pitch on stress distribution around the riveted hole are discussed. Finally, the fatigue tests are conducted with riveted lap joint specimens to verify the theoretical model and FE results, and a good agreement is observed. Based on the simulation and experimental results, a good combination of structural parameters of the riveted lap joint is found which can optimize the stress distribution around the riveted hole and improve the fatigue life of the riveted lap joint.The performance of the brewer's yeast Saccharomyces cerevisiae to remove metal ions from four batch systems, namely Zn(II), Zn(II)-Sr(II)-Cu(II), Zn(II)-Ni(II)-Cu(II), and Zn(II)-Sr(II)-Cu(II)-Ba(II), and one real effluent was evaluated. Yeast biosorption capacity under different pH, temperature, initial zinc concentration, and contact time was investigated. The optimal pH for removal of metal ions present in the analyzed solution (Zn, Cu, Ni, Sr, and Ba) varied from 3.0 to 6.0. The biosorption process for zinc ions in all systems obeys Langmuir adsorption isotherm, and, in some cases, the Freundlich model was applicable as well. The kinetics of metal ions biosorption was described by pseudo-first-order, pseudo-second-order, and Elovich models. Thermodynamic calculations showed that metal biosorption was a spontaneous process. The two-stage sequential scheme of zinc ions removal from real effluent by the addition of different dosages of new sorbent allowed us to achieve a high efficiency of Zn(II) ions removal from the effluent. FTIR revealed that OH, C=C, C=O, C-H, C-N, and NH groups were the main biosorption sites for metal ions.Natural tanzanites usually show strongly trichroic coloration from violet to blue, and brown colors in different directions. However, this characteristic is easily changed to violet-blue dichroism after heat treatment. Moreover, the cause of color modification after heating is still controversial. A few researchers have previously suggested that trace amounts of either vanadium or titanium substituted in aluminum site should be the main determinant of color after the heat treatment. Alteration of either V3+ to V4+ or Ti3+ to Ti4+ may relate to light absorption around 450-460 nm, which is the main cause. GSK1325756 molecular weight UV/vis/NIR absorption spectroscopy and X-ray absorption spectroscopy (XAS), a utility of synchrotron radiation, were applied for this experiment. As a result, the violet-blue absorption band (centered around 450-460 nm) as well as green absorption band (centered around 520 nm) were obviously decreased along the c-axis after heating, and XAS analysis indicated the increasing of the oxidation state of vanadium. This result was well supported by the chemical composition of samples. Consequently, vanadium was strongly suggested as the significant coloring agent in tanzanite after heat treatment.A self-designed Ti-35421 (Ti-3Al-5Mo-4Cr-2Zr-1Fe wt%) titanium alloy is a new type of low-cost high strength titanium alloy. In order to understand the hot deformation behavior of Ti-35421 alloy, isothermal compression tests were carried out under a deformation temperature range of 750-930 °C with a strain rate range of 0.01-10 s-1 in this study. Electron backscatter diffraction (EBSD) was used to characterize the microstructure prior to and post hot deformation. The results show that the stress-strain curves have obvious yielding behavior at a high strain rate (>0.1 s-1). As the deformation temperature increases and the strain rate decreases, the α phase content gradually decreases in the α + β phase region. Meanwhile, spheroidization and precipitation of α phase are prone to occur in the α + β phase region. From the EBSD analysis, the volume fraction of recrystallized grains was very low, so dynamic recovery (DRV) is the dominant deformation mechanism of Ti-35421 alloy. In addition to DRV, Ti-35421 alloy is more likely to occur in continuous dynamic recrystallization (CDRX) than discontinuous dynamic recrystallization (DDRX).We aimed to determine the usual intake of total fat, fatty acids (FAs), and their main food sources in a representative cohort of the Spanish pediatric population aged 1 to less then 10 years (n = 707) who consumed all types of milk and an age-matched cohort who consumed adapted milk over the last year (including follow-on formula, toddler's milk, growing-up milk, and fortified and enriched milks) (n = 741) who were participants in the EsNuPI study (in English, Nutritional Study in the Spanish Pediatric Population). Dietary intake, measured through two 24 h dietary recalls, was compared to the European Food Safety Authority (EFSA) and the Food and Agriculture Organization of the United Nations (UN-FAO) recommendations. Both cohorts showed a high intake of saturated fatty acids (SFAs), according to FAO recommendations, as there are no numerical recommendations for SFAs at EFSA. Also, low intake of essential fatty acids (EFAs; linoleic acid (LA) and α-linolenic acid (ALA)) and long-chain polyunsaturated fatty acids (LC-PUFA) of the n-3 series, mainly docosahexaenoic acid (DHA) were observed according to EFSA and FAO recommendations.