Application of the Hughes-LIU algorithm to the 2-dimensional heat equation

An implicit explicit algorithm for the solution of transient problems in structural dynamics is described. The method involved dividing the finite elements into implicit and explicit groups while automatically satisfying the conditions. This algorithm is applied to the solution of the linear, transient, two dimensional heat equation subject to an initial condition derived from the soluton of a steady state problem over an L-shaped region made up of a good conductor and an insulating material. Using the IIT/PRIME computer with virtual memory, a FORTRAN computer program code was developed to make accuracy, stability, and cost comparisons among the fully explicit Euler, the Hughes-Liu, and the fully implicit Crank-Nicholson algorithms. The Hughes-Liu claim that the explicit group governs the stability of the entire region while maintaining the unconditional stability of the implicit group is illustrated

Chronic Progressive External Ophthalmoplegia Is Associated with a Novel Mutation in the Mitochondrial tRNA(Asn) Gene

Chronic progressive external ophthalmoplegia (CPEO) is caused by a decreased oxidative phosphorylation (OXPHOS) activity due to large-scale deletions of the mitochondrial genome in 50 % of the patients. The deletions encompass structural OXPHOS genes as well as tRNA genes, required for their expression so that the pathogenesis could be due to the deleted OXPHOS subunits or to an impaired mitochondrial translation. We have analyzed the mitochondrial genome of a patient presenting with CPEO for single base substitutions and discovered a novel heteroplasmic mutation in the tRNAAsn gene at position 5692 that converts a highly conserved adenine into a guanine. This mutation is unique because it is located at the transition of the anticodon loop to the anticodon stem and it leads to an additional base pair, thus reducing the number of loop-forming nucleotides from seven to five. Our findings suggest that CPEO can be caused by a single base substition in a mitochondrial tRNA gene so that the mitochondrial protein synthesis becomes the rate limiting step in OXPHOS fidelity

Progression of myopathology in Kearns-Sayre syndrome

We report on the progression of myopathology by comparing two biopsies from a patient with a Kearns-Sayre-Syndrome. The first biopsy was taken in 1979 and showed 10% ragged-red fibers. Myopathic changes were slight including internal nuclei and fiber splitting in 10% of the fibers. Electron microscopy revealed typical mitochondrial abnormalities with regard to number and shape. In 1989 a second biopsy was performed for an extended analysis of mitochondrial DNA. This time less than 5% of all fibers were ragged-red. Severe myopathic changes could be detected which so far has rarely been reported in mitochondrial cytopathy

Film calibration for the Skylab/ATM S-056 X-ray telescope

The sensitometry and film calibration effort for the Skylab/ATM S-056 X-ray telescope is summarized. The apparatus and procedures used are described together with the two types of flight film used, Kodak SO-212 and SO-242. The sensitometry and processing of the flight film are discussed, and the results are presented in the form of the characteristic curves and related data. The use of copy films is also discussed

Bright Points and Subflares in UV Lines and in X-Rays

We have analysed an active region which was observed in Halpha (MSDP), UV lines (SMM/UVSP), and in X rays (SMM/HXIS). In this active region there were only a few subflares and many small bright points visible in UV and in X rays. Using an extrapolation based on the Fourier transform we have computed magnetic field lines connecting different photospheric magnetic polarities from ground-based magnetograms. Along the magnetic inversion lines we find 2 different zones: 1. a high shear region (less than 70 degrees) where subflares occur 2. a low shear region along the magnetic inversion line where UV bright points are observed

Multiferroic and magnetoelectric properties of Pb0.99[Zr0.45Ti0.47(Ni1/3Sb2/3)0.08]O3–CoFe2O4 multilayer composites fabricated by tape casting

A 2-2 type multiferroic composite device encompassing three CoFe2O4 (CFO) layers confined between four Pb0.99[Zr0.45Ti0.47(Ni1/3Sb2/3)0.08]O3 (PZT) layers was fabricated by tape casting. X-ray diffraction data showed good chemical compatibility between the two phases, whereas Scanning Electron Microscopy imaging also revealed an intimate contact between CFO and PZT layers. Under an applied electric field of 65 kV/cm, this multilayer device shows a saturated polarisation of 7.5 C/cm2 and a strain of 0.12%, whereas under a magnetic field of 10 kOe it exhibits a typical ferromagnetic response and a magnetic moment of 33 emu/g. These devices can be electrically poled, after which they exhibit magnetoelectric coupling