Local projection finite element stabilization for the generalized Stokes problem

We analyze pressure stabilized finite element methods for the solution of the generalized Stokes problem and investigate their stability and convergence properties. An important feature of the method is that the pressure gradient unknowns can be eliminated locally thus leading to a decoupled system of equations. Although stability of the method has been established, for the homogeneous Stokes equations, the proof given here is based on the existence of a special interpolant with additional orthogonal property with respect to the projection space. This, makes it a lot simpler and more attractive. The resulting stabilized method is shown to lead to optimal rates of convergence for both velocity and pressure approximations

Pre- and post-processing for Cosmic/NASTRAN on personal computers and mainframes

An interface between Cosmic/NASTRAN and GIFTS has recently been released, combining the powerful pre- and post-processing capabilities of GIFTS with Cosmic/NASTRAN's analysis capabilities. The interface operates on a wide range of computers, even linking Cosmic/NASTRAN and GIFTS when the two are on different computers. GIFTS offers a wide range of elements for use in model construction, each translated by the interface into the nearest Cosmic/NASTRAN equivalent; and the options of automatic or interactive modelling and loading in GIFTS make pre-processing easy and effective. The interface itself includes the programs GFTCOS, which creates the Cosmic/NASTRAN input deck (and, if desired, control deck) from the GIFTS Unified Data Base, COSGFT, which translates the displacements from the Cosmic/NASTRAN analysis back into GIFTS; and HOSTR, which handles stress computations for a few higher-order elements available in the interface, but not supported by the GIFTS processor STRESS. Finally, the versatile display options in GIFTS post-processing allow the user to examine the analysis results through an especially wide range of capabilities, including such possibilities as creating composite loading cases, plotting in color and animating the analysis

Similarity between the primary and secondary air-assisted liquid jet breakup mechanism

we report an ultrafast synchrotron x-ray phase contrast imaging study of the primary breakup mechanism of a coaxial air-assisted water jet. We demonstrate that there exist great similarities in the phenomenology of primary breakup with that of the secondary breakup. Especially, a membrane-mediated breakup mechanism dominates the breakup process for a wide range of air speeds. This finding reveals the intrinsic connections of these two breakup regimes and has deep implications on the unified theoretical approach in treating the breakup mechanism of high speed liquid jet.Comment: 15 pages, 4 figure

Perturbation method in the theory of nonlinear oscillations

Perturbation expansions for nonlinear oscillations based on Lie transform

Web-based bioinformatic resources for protein and nucleic acids sequence alignment

DNA sequencing is the deciphering of hereditary information. It is an indispensable prerequisite for many biotechnical applications and technologies and the continual acquisition of genomic information is very important. This opens the door not only for further research and better understanding of the architectural plan of life, but also for future clinical diagnosis based on the genetic data of individuals. Bioinformatics can be broadly defined as the creation and development of advanced information and computational techniques for problems in biology. More narrowly, bioinformatics is the set of computing techniques used to manage and extract useful information from the DNA/RNA/protein sequence data being generated (at high volumes) by automated techniques (e.g., DNA sequencers, DNA microarrays) and stored in large public databases (e.g., GenBank, Protein DataBank). Certain method for analyzing genetic/protein data has been found to be extremely computationally intensive, providing motivation for the use of powerful computers. The advent of the Internet and the World Wide Web (WWW) has substantially increased the availability of information and computational resources available to experimental biologists. This review will describe the current on-line resources available, including protein and nucleic acids sequence alignment. Key words: Sequence alignment, DNA, Protein, ClustalW, FASTA. African Journal of Biotechnology Vol. 2 (12), pp. 714-718, December 200

Bioinformatic tools and guideline for PCR primer design

Bioinformatics has become an essential tool not only for basic research but also for applied research in biotechnology and biomedical sciences. Optimal primer sequence and appropriate primer concentration are essential for maximal specificity and efficiency of PCR. A poorly designed primer can result in little or no product due to non-specific amplification and/or primer-dimer formation, which can become competitive enough to suppress product formation. There are several online tools devoted to serving molecular biologist design effective PCR primers. This review intends to provide a guide to choosing the most efficient way to design a new specific-primer by applying current publicly available links and Web services. Also, the purpose here is to provide general recommendations for the design and use of PCR primers. (African Journal of Biotechnology: 2003 2(5): 91-95