BACKGROUND Native American tribes, as sovereign nations, are exempt from state tobacco excise taxation, and self-govern on-reservation activity in the USA. Under Federal law, state excise taxes are owed by non-members purchasing tobacco on tribal land, but states are limited in how they enforce or collect these taxes. This study highlights the various policy approaches that states have taken to...

PurposeTo examine the pandemic response plans of institutes higher education (i.e., colleges and universities), including COVID-19 prevention, enforcement, testing strategies.MethodData from largest public (n = 50) private US were collected October 30 to November 20, 2020.ResultsMost 93) offered some in-person teaching in Fall 2020 semester; most adopted masking (100%) physical distancing (99%)...

Solid Freeform Fabrication (SFF) refers to a class of rapid manufacturing process that builds parts by incremental material deposition and fusion of thin 2-1/2 dimensional layers. Over this past decade, SFF has taken the manufacturing industry to new heights. However, parts produced by SFF processes exhibit a stair-step surface texture due to the presence of 2-1/2 dimensional layers and exhibit...

Fine reactive alumina powders have a significant impact on the properties of refractories at high temperatures. Except for hydration cement and in situ reactions, performance castables is also correlated with sintering alumina. The characteristics fine produced by various manufacturers are quite different. This work aims to investigate comprehensive influence powder behaviour powders. Three typ...

For a unital C*-algebra A, which is equipped with a spectral triple (A,H,D) and an extension T of A by the compacts, we construct a two parameter family of spectral triples (At,K,Dα,β) associated to T . Using Rieffel’s notation of quantum Gromov-Hausdorff distance between compact quantum metric spaces it is possible to define a metric on this family of spectral triples, and we show that the dis...

Powder compaction technology has advanced significantly over the past decades and is considered as an alternative lower-cost process to machining, casting, stamping, forging and other similar metal-working technologies. Feedstock preparation is considered a vital step in producing parts through the powder route because any inhomogeneity within the powder mass would cause inhomogeneous density d...

TiSi2/SiC composites are promising materials for high temperature applications. The synthesis of these by metal infiltration is an interesting method that not still mastered. This study aims at identifying the thermodynamic and kinetic processes involved during capillary liquid silicon or Si-Ti molten alloys in porous compacts. Three cases were examined to produce dense materials: 1) TiSi2 pure...