An automatic image analysis system for RLGS films

The RLGS (Restriction Landmark Genome Scanning) method was originally developed as a powerful method for enabling viewing of thousands of restriction landmarks. It offers a tool for obtaining information about genetic loci, with a single RLGS profile displaying approximately 2000 restriction landmarks as spots. One of the most useful applications is RLGS spot mapping, which allows the efficient, low-cost construction of the genetic map of any organism. However, analyses of the profiles depend mainly on human visual observation and are tedious and laborious. Although several commercially available image analyzing systems for profile comparison have been examined, they cannot be used for the RLGS spot mapping system owing to the background characteristics of the RLGS profiles, unsatisfactory rates of correspondence, and inefficient correction of informative genetic data. We therefore developed a novel automatic image analysis system for RLGS spot mapping, using an original algorithm based on the binary image transferred from the original RLGS profile. This system was employed for identifying non-polymorphic and parental strain-specific polymorphic spots of the F1 mouse profile and yielded efficient initial screening of RLGS profiles.     

Synthesis of nanocomposite thin films based on the Mo-Si-C ternary system and compositional tailoring through controlled ion bombardment

A major advantage of sputtering processes compared to evaporation processes is the possibility of synthesizing films that replicate the composition of the source (target) material,particularly in the case of alloy targets. This is related to the unique feature of sputtering, viz, formation of an “altered layer” which facilitates reproduction of the target composition in the thin film. An exciting and novel area of research deals with the synthesis of nanocomposite thin films by sputtering composite targets. In this article, the feasibility of depositing a composite thin film based on the Mo-Si-C temary system through RF magnetron sputtering of a MoSi₂+XSiC target, and the possibility of modifying the film composition by controlled ion bombardment (i.e., “ion plating” or “bias sputtering”), will be discussed. In this context, the role of the sputter yields for Mo, Si, and C will be examined with respect to the ability to vary the composition of as-deposited films. In addition, the modifications which were required to sputter a 58.4-mm-diameter composite target (produced inhouse, by different synthesis reactions) using a 127×381-mm Vac Tec cathode will be discussed. Details of Auger electron spectroscopy (AES) scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses of the as-deposited films will be presented.     

Cracking of brittle films on elastic substrates

An analysis is presented that relates the crack spacing in a brittle film on an elastic substrate to the stress in the film, its thickness and fracture toughness. This analysis differs from an earlier one presented by one of the authors in that it considers the effect of a sequential, rather than a concerted, propagation of cracks, and predicts a larger crack spacing. The validity of the present analysis was confirmed by experimental results from a model system consisting of epitaxial PrBa₂Cu₃O_7−x films on SrTiO₃ substrates. The experimentally observed relationship between the crack spacing and the film thickness was in excellent agreement with the theory.