Precessing Jets and Molecular Outflows: A 3-D Numerical Study

We present 3-D numerical hydrodynamical simulations of precessing supersonic heavy jets to explore how well they serve as a model for generating molecular outflows from Young Stellar Objects. The dynamics are studied with a number of high resolution simulations on a Cartesian grid (128x128x128 zones) using a high order finite difference method. A range of cone angles and precession rates were included in the study. Two higher resolution runs (256x256x256 zones) were made for comparison in order to confirm numerical convergence of global flow characteristics. Morphological, kinematical and dynamical characteristics of precessing jets are described and compared to important properties of straight jets and also to observations of YSOs. In order to examine the robustness of precessing jets as a mean to produce molecular outflows around Young Stellar Objects, ``synthetic observations'' of the momentum distributions of the simulated precessing jets are compared to observations of molecular outflows. It is found that precessing jets match better the morphology, highly forward driven momentum and momentum distributions along the long axis of molecular outflows than do wind-driven or straight jet-driven flow models.Comment: Accepted by ApJ, 31 pages, using aasms.sty, Also available in postscript with figures via a gzipped tar file at ftp://s1.msi.umn.edu/pub/afrank/3DJet/3DJet.tar.gz . For information contact [email protected]

Oblique MHD cosmic-ray modified shocks: Two-fluid numerical simulations

We present the first results of time dependent, two-fluid, cosmic-ray (CR) modified, MHD shock simulations. The calculations were carried out with a new numerical code for 1-D ideal MHD. By coupling this code with the CR energy transport equation we can simulate the time-dependent evolution of MHD shocks including the acceleration of the CR and their feedback on the shock structures. We report tests of the combined numerical method including comparisons with analytical steady state results published earlier by Webb, as well as internal consistency checks for more general MHD CR shock structures after they appear to have converged to dynamical steady states. We also present results from an initial time dependent simulation which extend the parameter space domain of previous analytical models. These new results support Webb's suggestion that equilibrium oblique shocks are less effective than parallel shocks in the acceleration of CR. However, for realistic models of anisotropic CR diffusion, oblique shocks may achieve dynamical equilibrium on shorter timescale than parallel shocks

The impending medical revolution in haemophilia care: one patient’s view

The history of haemophilia care has been fraught with extreme successes and epic failures. The development of plasma-derived concentrates made prophylactic treatment and home care possible, but the unintended consequences were devastating for a generation and only abated with the emergence of recombinant products. Now with the arrival of longer-acting factor concentrates and the potential offered by gene therapy, further improvements in medical and social outcomes are possible. But these new treatment approaches raise challenging ethical and moral issues that society must be prepared to confront

Primitive ideals in rational, nilpotent Iwasawa algebras

Given a $p$-adic field $K$ and a nilpotent uniform pro-$p$ group $G$, we prove that all primitive ideals in the $K$-rational Iwasawa algebra $KG$ are maximal, and can be reduced to a particular standard form. Setting $\mathcal{L}$ as the associated $\mathbb{Z}_p$-Lie algebra of $G$, our approach is to study the action of $KG$ on a Dixmier module $\widehat{D(\lambda)}$ over the affinoid envelope $\widehat{U(\mathcal{L})}_K$, and to prove that all primitive ideals can be reduced to annihilators of modules of this form.Comment: 44 pages, 5 section

See man

2018 Spring.Includes bibliographical references.My research asks a series of questions about how societal pressures sculpt male cultural roles in the United States. What components constitutes being a man? How have the constructed ideologies adopted by Americans affected my livelihood? How do the patriarchal structures in place shape my world view? Being a white, heterosexual male who fits within the privileged patriarchal systems of the United States, I feel a calling and obligation to utilize my voice to expose the toxic effects these systems have had on me and the rest of the American population. Toxic forms of masculinity are creating displacement, marginalization, and oppression of large groups of Americans. My work is an investigation aiming to unveil and exploit the effects of the ideologies of Christianity, nationalism and capitalism, and how these ideologies reinforce the toxic hegemonic masculine engine. The focus of my practice is to create and incorporate coded symbols and non-traditional painting materials as metaphors for stereotyped manliness

The Blessings of Being God\u27s People: Election in the Book of Isaiah

Over the years, the doctrine of election, or God choosing a people, has been a highly debated topic. Two thousand years of church history can attest to that, and even today churches split over disagreements about the topic. To begin to gain a clearer understanding of this doctrine, one must set aside common presuppositions, expectations, and even the understanding in church history. Often, election is seen as a New Testament doctrine. However, it is important to remember that the Old Testament forms the background for the New Testament and is often quoted in New Testament passages. Isaiah is heavily relied upon in the New Testament and therefore it is a good choice for a study of Old Testament texts on this topic. It is important in such a study to read the Old Testament texts without anachronistically injecting New Testament teachings. Isaiah 41:8-20; 43:1-13,19-21; 44:1-5; 49:1-7 each contain the Hebrew root ,בחר meaning “to choose,” which is clearly tied to election theology in the Old Testament. Further, these four passages are all in the same section of Isaiah. In addition, these passages contain quite a bit of Exodus imagery, in which God maintains his faithfulness to his chosen people, Israel, even when they sin and turn their backs on him. In this way, the Exodus imagery highlights the chosen status of Israel. Thus, the fact that this small section of Isaiah has such a concentration of passages containing בחר and election imagery from Exodus indicates that it is a good place to look to begin to understand what the Old Testament has to say about election, specifically what being chosen by God meant for Israel