The expansion of molten aluminum foam was studied to determine flow mechanisms in the cellular melt. The structure of the foaming melt evolved through a series of deformation stages before the foam stabilized and solidified. Changes in cell geometry during foam expansion were observed at different positions within the mold cavity and analyzed to determine flow mechanisms. The deformation patter...

A concept for the casting of metallic fuels pins containing low vapor pressure materials is presented and discussed. The important physics of this concept include the mass transport of americium from the melt, the induction heating and stirring of the melt, plus the casting of long slender fuel rods. This paper discusses and presents preliminary modeling results for the casting of long, slender...

As is well known, the extrusion rate of polymers from a cylindrical tube or slit (a "die") is in practice limited by the appearance of "melt fracture" instabilities which give rise to unwanted distortions or even fracture of the extrudate. We present the results of a weakly nonlinear analysis which gives evidence for an intrinsic generic route to melt fracture via a weakly nonlinear subcritical...

The present invention is directed to a method for powder coating a metal substrate using a low-melt polyamic acid (PAA) polymer that readily imidizes to polyimides. These low-melt PAAs have been shown to be useful in resins applied as powder coatings to metal surfaces. The resin includes an end-capping material capable of providing crosslinking functionality to at least one end of the low-melt ...

used pet bottles disposal is an unsolved environmental problem, and there are many efforts for finding an applicable solution for it. many researches have showed that the degradation rate of the polymers increase with the smaller size of fibers. this work was carried out to convert used pet bottles into nanofibers by melt-electrospinning method. uncolored, washed and chipped pet bottles and the...

buchitic glassy rocks appear within the skarn of contact metamorphic aureole of feshark intrusive complex situated 30 km northeast of isfahan. intrusive complex is a multistage intrusion . noritic gabbro is the first inttrusion which is invaded later on by a granitic melt. granitic melt has metasomatically altered the gabbro and as a consequence a suite of hybrid rocks like monzogabbro, monzodi...

A novel method for the synthesis of a new class of thermotropic liquid crystalline polymers has been developed: it proceeds via a polyaddition reaction involving diepoxy-containing mesogene groups and a monoamine (aniline). The reaction between the epoxy ring and the primary amine produces an intermediate containing a secondary amine which undergoes further reaction with an epoxy ring of anothe...

one of the most important hydrological time series task is to determine if there is any trend in the data and how to achieve stationarity when there is nonstationarity behavior in data. detecting trend and stationarity in hydrological time series may help us to understand the possible links between hydrological processes and global climate changes. in this study yearly, monthly and daily stream...

Lavas from the Puʻu ʻŌʻō eruption of Kīlauea Volcano are thought to partially bypass the shallow magma reservoir beneath the volcano's summit, and thus, provide a relatively direct “window” to the mantle. Here we use high-precision U-series isotope measurements of Puʻu ʻŌʻō lavas (1985–2001) to investigate the timing and mechanism of melt transport within the Hawaiian mantle plume. The lavas di...

In typical solidification processes the flow of molten metal is usually regarded as an unavoidable phenomenon potentially affecting the morphology of dendritic growth. Fundamental understanding of such flow is thus important for predicting and controlling solidification microstructures. This paper presents numerical simulations on the evolution of dendritic microstructures with melt convection....