We present the results of the first X-ray gratings spectroscopy observations of a planetary nebula (PN), the X-ray-bright, young BD+303639. We observed BD+303639 for a total of 300 ks with the Chandra X-ray Observatory’s Low Energy Transmission Gratings in combination with its Advanced CCD Imaging Spectrometer (LETG/ACIS-S). The LETG/ACIS-S spectrum of BD+303639 is dominated by H-like resonance...

We explore the effects on nucleosynthesis in Type II supernovae of various parameters (mass cut, neutron excess, explosion energy, progenitor mass) in order to explain the observed trends of the ironpeak element abundance ratios ([Cr/Fe], [Mn/Fe], [Co/Fe] and [Ni/Fe]) in halo stars as a function of metallicity for the range −4 ≤ [Fe/H] ≤ −2.5. [Cr/Fe] and [Mn/Fe] decrease with decreasing [Fe/H]...

We present the results of the first X-ray gratings spectroscopy observations of a planetary nebula (PN), the X-ray-bright, young BD+303639. We observed BD+303639 for a total of 300 ks with the Chandra X-ray Observatory’s Low Energy Transmission Gratings in combination with its Advanced CCD Imaging Spectrometer (LETG/ACIS-S). The LETG/ACIS-S spectrum of BD+303639 is dominated by H-like resonance...

achillea tenuifolia lam. (asteraceae) afforded a dichloromethane fraction from which three known compounds β-sitosterol (compound1), 5-hydroxy, 4',6,7– trimethoxy flavone (salvigenin compound 2), and methyl-gallate (compound 3) were isolated for the first time. the structure of isolated compounds was elucidated by different spectroscopic methods. applying the molar-ratio method, the comple...

Human serum albumin (HSA) is involved physiologically in heme scavenging; in turn, heme-albumin (HSA-heme-Fe) displays globin-like properties. Here, the allosteric effect of ibuprofen and warfarin on the local atomic structure around the ferric heme-Fe (heme-Fe(III)) atom of HSA-heme-Fe (HSA-heme-Fe(III)) has been probed by Fe-K edge X-ray absorption spectroscopy (XAS). The quantitative analysi...

Oxygen fugacity in metal-bearing systems controls some fundamental aspects of the geochemistry of the early Earth, such as the FeO and siderophile trace element content of the mantle, volatile species that influence atmospheric composition, and conditions for organic compounds synthesis. Redox and metal-silicate equilibria in the early Earth are sensitive to oxygen fugacity (fO(2)), yet are poo...

The impact of anthropogenic sound on marine mammals is difficult to assess, especially for species without available audiograms. There are currently no audiograms for any species of mysticete because of their size and, in many cases, their endangerment status. Consequently, insight into the hearing range of all mysticete species comes from indirect sources such as vocalization recordings. In co...

This research presents an investigation into the numerical simulation of a flexible thin plate using Finite Difference (FD) and Finite Element (FE). Based on the FD method, an appropriate model of a thin plate was derived and its corresponding natural frequencies were estimated. Then, FE modeling of the plate system was implemented using the ANSYS software and the corresponding modes of vibrati...

The characteristic of effective properties of physical processes in heterogeneous media is a basic modeling and computational problem for many applications. As standard numerical discretization of such multiscale problems (e.g. with classical finite element method (FEM)) is often computationally prohibitive, there is a need for a novel computational algorithm able to capture the effective behav...

It is the purpose of this work to investigate whether it is feasible to develop Finite Element (FE) models that take into account the geometric differences between the lumbar vertebrae of patients. It is also the purpose of this work to determine whether or not such patient specific differences affect the results of the FE analysis in such a significant way that they should be considered in fut...