A nondestructive study of the internal structure and compositional gradient of dissimilar metal-alloy welds through energy-resolved neutron imaging is described in this paper. The ability of neutrons to penetrate thick metal objects (up to several cm) provides a unique possibility to examine samples which are opaque to other conventional techniques. The presence of Bragg edges in the measured n...

Corrosion in pipe work is a major problem. While most plants have reliable information on most equipment, the least data available is always with respect to their piping. Significant portions of plant piping and pipelines are insulated or buried and hence, even external corrosion cannot be readily observed. Ultrasonic guided waves in the pipe wall provide an attractive solution as the waves are...

Hypergraphic matroids were de ned by Lorea as generalizations of graphic matroids. We show that the minimum cut (co-girth) of a multiple of a hypergraphic matroid can be computed in polynomial time. It is well-known that the size of the minimum cut (co-girth) of a graph can be computed in polynomial time. For connected graphs, this is equivalent to computing the co-girth of the circuit matroid....

Girth pairs were introduced by Harary and Kovács [Regular graphs with given girth pair, J. Graph Theory 7 (1983) 209–218]. The odd girth (even girth) of a graph is the length of a shortest odd (even) cycle. Let g denote the smaller of the odd and even girths, and let h denote the larger. Then (g, h) is called the girth pair of the graph. In this paper we prove that a graph with girth pair (g, h...

A method to construct girth-12 (3,L) quasi-cyclic lowdensity parity-check (QC-LDPC) codes with all lengths larger than a certain given number is proposed, via a given girth-12 code subjected to some constraints. The lengths of these codes can be arbitrary integers of the form LP, provided that P is larger than a tight lower bound determined by the maximal element within the exponent matrix of t...

It is well known that 3–regular graphs with arbitrarily large girth exist. Three constructions are given that use the former to produce non-Hamiltonian 3–regular graphs without reducing the girth, thereby proving that such graphs with arbitrarily large girth also exist. The resulting graphs can be 1–, 2– or 3–edge-connected depending on the construction chosen. From the constructions arise (nai...

With fossil fuels being phased out and growing global interest in a hydrogen economy, there is demand for re-purposing existing pipelines transportation of gas. However, embrittlement (HE) can limit pipeline steel’s performance. In this study, the effect on mechanical properties an X60 base metal (polygonal ferrite/pearlite) its girth weld (acicular was measured with novel slow strain rate tens...

In the automotive industry, a barrier to widespread implementation of friction stir welding (FSW) for aluminum joining is the perceived need for high cost, custom capital machinery. The reason for this perception is that the FSW process requires relatively large forces that commonly used automation machinery (e.g. an industrial robot) has difficulty producing. Further complicating the issue, is...

Marine fungi are an understudied group of eukaryotic microorganisms characterized by unresolved genealogies and unstable classification. Whereas DNA barcoding via the nuclear ribosomal internal transcribed spacer (ITS) provides a robust and rapid tool for fungal species delineation, accurate classification of fungi is often arduous given the large number of partial or unknown barcodes and misid...

An evaluation of reproductive performance, behavior, immunity and ergonomics was conducted for two common sow housing systems: the girth tether and crate. Littermate Yorkshire × Landrace gilts were randomly assigned to either the crate or girth tether system and they remained in that treatment for two consecutive pregnancies and lactations. A total of 171 matings resulted in 141 litters (82.4% ...