A two part study utilizing polyoxymethylene (POM) was undertaken to investigate a three stage process (Melt-Extrusion/Annealing/Uniaxial-Stretching) (MEAUS) employed to produce microporous films. In this first part, three POM resins (D, E & F) were melt-extruded into tubular films (blowup ratio; BUR = 1), where resin D has a higher weight average molecular weight (Mw) than resin E but both poss...

Objectives. The object of this study was to examine whether college-intending, low-income high school graduates are particularly susceptible to having their postsecondary education plans change, or even fall apart, during the summer after high school graduation. College access research has largely overlooked this time period. Yet, previous research indicates that a sizeable share of low-income ...

A study utilizing isotactic poly(4-methyl-1-pentene) (PMP) was undertaken to investigate a three stage process (melt-extrusion/annealing/uniaxial-stretching) (MEAUS) employed to produce microporous films. The results of this study will be reported in the course of two papers. In this first part, three PMP resins were melt-extruded into tubular films (blowup ratio; BUR = 1), where the resins eac...

Isotactic polypropylenes (iPP) with different melt flow indexes (MFI) were used to fabricate nanocomposites (NCs) with 10 wt % loadings of multi-wall carbon nanotubes (MWCNTs) using ultrasound-assisted extrusion methods to determine their effect on the morphology, melt flow, and electrical properties of the NCs. Three different types of iPPs were used with MFIs of 2.5, 34 and 1200 g/10 min. Fou...

We report laboratory determinations of the shear resistance to sliding melting ice with entrained particles over a hard, impermeable surface. With higher particle concentrations and larger particle sizes, Coulomb friction at particlebed contacts dominates and the shear stress increases linearly with normal load. We term this the sandy regime. When either particle concentration or particle size ...

A bedload trap in the riverbed provided direct quantitative measurement of debris-transport rate in the East Fork River, Wyoming, a basin of 466 km(2) drainage area. Traction load moves only during the spring snow melt season. Data collected in three spring runoff seasons during which a peak flow of 45 m(3)/s occurred showed that transport rate is correlated with power expenditure of the flowin...

[1] Phase equilibrium experiments on primitive Miocene olivine leucitite (Bb-107) from the Qiangtang terrane of the Tibetan Plateau were performed from 1.0 to 2.2 GPa and 1270 to 1440 C. The composition is multiply saturated with olivine and clinopyroxene from 1.2 to 2.2 GPa and 1340 C under nominally anhydrous conditions. Phase assemblages in the experiments have been used to model the effects...

full factorial experimental design (23) for the evaluation of slurry ethylene polymerization in the presence of an industrial ticl4/mgcl2 ziegler-natta catalyst was employed. the following parameters were used as independentvariables: al/ti molar ratio, reaction temperature and hydrogen partial pressure. the total polymerization pressure was 9 bar. catalyst activity, mfi (melt flow index) and m...

The existence of partial melt is frequently invoked to explain geophysical anomalies such as low seismic wave velocity and high electrical conductivity. I review various experimental and theoretical studies to evaluate the plausibility of this explanation. In order for a partial melt model to work, not only the presence of melt, but also the presence of appropriate amount of melt needs to be ex...