The application of interactive graphics to large time-dependent hydrodynamics problems

A written companion of a movie entitled "Interactive Graphics at Los Alamos Scientific Laboratory" was presented. While the movie presents the actual graphics terminal and the functions performed on it, the paper attempts to put in perspective the complexity of the application code and the complexity of the interaction that is possible

Verleden boven Water Erfgoed, identiteit en binding in de IJsselmeerpolders

Legene, S. [Promotor]Kolen, J.C.A. [Copromotor

Pionieren in Poort: de culturele constructie van Almere

Museologist Simon Knell stated recently that museums are performativespaces in which identity is presented in the form of myths. The following articleapplies Knell’s approach to a recent museological project of museum ‘DePaviljoens’ in Almere (Netherlands): Pioneering in Poort. It is shown how museological authority is used in the construction of a cultural identity in a placewhere it is not yet self-evident: a recent housing estate. Through the use of aperformance combining history, culture and modern art an attempt is made inthis recently reclaimed land to provide the polder city Almere and its inhabitantswith a collective identity

Culturing Glioblastoma Cancer Stem Cells

Glioblastoma multiforme is a malignant tumor that grows in the human brain. Patients diagnosed with Glioblastomas (GBM) require very extensive and invasive treatment that includes surgery, chemotherapy, and radiation. Although these treatments are effective for other types of cancer, the rate of recurrence for Glioblastomas are extremely high. After being diagnosed, patients survive an average of 12-15 months afterwards (Ogura, et. al.,). The believed reason for this rate are the Glioblastoma stem cells present in the tumor prior to treatment. These stem cells are essentially identical to Glioblastoma cells that make up the bulk of the tumor, however, they have certain characteristics that allow them to have resistance to cancer treatments. It is difficult to identify stem cells because they are relatively rare and there is an absence of markers to identify them, increasing the difficulty to study them. Stem cells also show continual cell genesis in the central nervous system resulting in the production of functional progeny, allowing for the return of the malignant Glioblastoma tumor (Identification and Characterization of Neural Stem Cells: Why is this so darned difficult?, 2010). Current research in this subject has become especially pressing since there is a promise of a cure for Glioblastomas through STEM cells. Research with STEM cells in order to decrease its resistance to radiation is the main focus. Therefore, through this project we hoped to contribute some understanding and insight for better treatment options for GBMs.B.A. (Bachelor of Arts

Color-superconductivity in the strong-coupling regime of Landau gauge QCD

The chirally unbroken and the superconducting 2SC and CFL phases are investigated in the chiral limit within a Dyson-Schwinger approach for the quark propagator in QCD. The hierarchy of Green's functions is truncated such that at vanishing density known results for the vacuum and at asymptotically high densities the corresponding weak-coupling expressions are recovered. The anomalous dimensions of the gap functions are analytically calculated. Based on the quark propagator the phase structure is studied, and results for the gap functions, occupation numbers, coherence lengths and pressure differences are given and compared with the corresponding expressions in the weak-coupling regime. At moderate chemical potentials the quasiparticle pairing gaps are several times larger than the extrapolated weak-coupling results.Comment: 14 pages, 9 figures; v2: one reference adde

A luminosity monitor for the A4 parity violation experiment at MAMI

A water Cherenkov luminosity monitor system with associated electronics has been developed for the A4 parity violation experiment at MAMI. The detector system measures the luminosity of the hydrogen target hit by the MAMI electron beam and monitors the stability of the liquid hydrogen target. Both is required for the precise study of the count rate asymmetries in the scattering of longitudinally polarized electrons on unpolarized protons. Any helicity correlated fluctuation of the target density leads to false asymmetries. The performance of the luminosity monitor, investigated in about 2000 hours with electron beam, and the results of its application in the A4 experiment are presented.Comment: 22 pages, 12 figures, submitted to NIM

Boron enrichment in Martian clay

We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration

WKB Across Caustics: The Screened-WKB Method

We present a new methodology, based on the WKB approximation and Fast Fourier Transforms, for the evaluation of wave propagation through inhomogeneous media. This method can accurately resolve fields containing caustics, while still enjoying the computational advantages of the WKB approximation, namely, the ability to resolve arbitrarily high-frequency problems in computing times which are orders-of-magnitude shorter than those required by other algorithms presently available. For example, the proposed approach can simulate with high accuracy (with errors such as e.g. 0.1\%--0.001\%) the propagation of 5 cm radar signals across two-dimensional configurations resembling atmospheric ducting conditions, spanning hundreds of kilometers and millions of wavelengths in electrical size, in computing times of a few minutes in a single CPU core. [Preliminary version]Comment: 13 pages, 14 figure

Investigation of the Spark channel of Electrical Discharges Near the Minimum Ignition Energy

In this work, we investigate the expansion of the hot gas kernel and pressure wave induced by electrical discharges near the minimum ignition energy experimentally by means of a schlieren setup and numerically through one-dimensional simulations. The effects of discharge energy and energy density on the expansion are discussed. Via comparison of experimental values with numerical simulations, an estimate of the overall losses of the discharge is presented