53 research outputs found
Spectrum and Wave Functions of Excited States in Lattice Gauge Theory
We suggest a new method to compute the spectrum and wave functions of excited
states. We construct a stochastic basis of Bargmann link states, drawn from a
physical probability density distribution and compute transition amplitudes
between stochastic basis states. From such transition matrix we extract wave
functions and the energy spectrum. We apply this method to lattice
gauge theory. As a test we compute the energy spectrum, wave functions and
thermodynamical functions of the electric Hamiltonian and compare it with
analytical results. We find excellent agreement. We observe scaling of energies
and wave functions in the variable of time. We also present first results on a
small lattice for the full Hamiltonian including the magnetic term.Comment: Lattice 2008 conferenc
Coherent diffraction of single Rice Dwarf virus particles using hard X-rays at the Linac Coherent Light Source
Single particle diffractive imaging data from Rice Dwarf Virus (RDV) were recorded using the Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS). RDV was chosen as it is a wellcharacterized model system, useful for proof-of-principle experiments, system optimization and algorithm development. RDV, an icosahedral virus of about 70 nm in diameter, was aerosolized and injected into the approximately 0.1 mu m diameter focused hard X-ray beam at the CXI instrument of LCLS. Diffraction patterns from RDV with signal to 5.9 angstrom ngstrom were recorded. The diffraction data are available through the Coherent X-ray Imaging Data Bank (CXIDB) as a resource for algorithm development, the contents of which are described here.11Ysciescopu
Coherent soft X-ray diffraction imaging of coliphage PR772 at the Linac coherent light source
Single-particle diffraction from X-ray Free Electron Lasers offers the potential for molecular structure determination without the need for crystallization. In an effort to further develop the technique, we present a dataset of coherent soft X-ray diffraction images of Coliphage PR772 virus, collected at the Atomic Molecular Optics (AMO) beamline with pnCCD detectors in the LAMP instrument at the Linac Coherent Light Source. The diameter of PR772 ranges from 65â70ânm, which is considerably smaller than the previously reported ~600ânm diameter Mimivirus. This reflects continued progress in XFEL-based single-particle imaging towards the single molecular imaging regime. The data set contains significantly more single particle hits than collected in previous experiments, enabling the development of improved statistical analysis, reconstruction algorithms, and quantitative metrics to determine resolution and self-consistency
Retracted: A survey of jundishapur medical sciences university students viewpoints in Ahvaz considering the effective components in the marketing process of libraries based on the principles of marketing mix (9P's model)
This article was withdrawn and retracted by the Journal of Fundamental and Applied Sciences and has been removed from AJOL at the request of the journal Editor in Chief and the organisers of the conference at which the articles were presented (www.iccmit.net). Please address any queries to [email protected]
Single-particle structure determination by X-ray free-electron lasers: Possibilities and challenges
Single-particle structure recovery without crystals or radiation damage is a
revolutionary possibility offered by X-ray
free-electron
lasers, but it involves formidable experimental and data-analytical
challenges. Many of these difficulties were encountered during the development of
cryogenic
electron
microscopy of biological systems. Electron microscopy of
biological entities has now reached a spatial resolution of about 0.3ânm, with a rapidly
emerging capability to map discrete and continuous conformational changes
and the energy landscapes of biomolecular machines. Nonetheless, single-particle imaging
by X-ray
free-electron
lasers remains important for a range of applications, including the
study of large âelectron-opaqueâ objects and time-resolved examination of key biological
processes at physiological temperatures. After summarizing the state of the art in the
study of structure and conformations by cryogenic
electron
microscopy, we identify the primary opportunities and challenges facing
X-ray-based single-particle approaches, and possible means for circumventing them
Unconstrained melting inside a sphere
This paper presents both numerical and experimental investigations on unconstrained melting of phase change material (PCM) using n-octadecane inside a spherical container. Experimental studies are performed for three different wall temperatures of the container at 35 °C, 40 °C and 45 °C with the PCM at an initial sub-cooling of 1 °C below the melting temperature. Numerical simulations are performed for axisymmetric melting of PCM inside a sphere using the Fluent 6.3 software. After validating the numerical results with the experimental data, the effect of shell diameter on melting at different Stefan numbers is studied numerically. The results indicate that the melting rate is high at the beginning of melting due to perfect contact between the hot shell and solid PCM. The melting rate reduces with progressing time when a layer of molten PCM is formed between the shell and solid PCM. After this stage, the effect of conduction heat transfer diminishes and restricted to the bottom of sphere where the solid PCM sinks. At both sides of the sphere, convection heat transfer in the liquid PCM becomes the dominant mode for melting
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