The effect of tungsten erosion, transport, and redeposition on the operation of dispenser hollow cathodes was investigated in detailed examinations of the discharge cathode inserts from 8200 h and 30 352 h ion engine wear tests. Erosion and subsequent redeposition of tungsten in the electron emission zone at the downstream end of the insert reduce the porosity of the tungsten matrix, preventing...

Halloysite nanotubes (HNTs) were investigated as a platform for tunable nanoparticle composition and enhanced opacity in poly(methyl methacrylate) (PMMA) bone cement. Halloysite has been widely used to increase the mechanical properties of various polymer matrices, in stark contrast to other fillers such as barium sulfate that provide opacity but also decrease mechanical strength. The present w...

A barium enema is a diagnostic and therapeutic procedure commonly used for colon and rectum problems. Rectal perforation with extensive intra- and/or extraperitoneal spillage of barium is a devastating complication of a barium enema that leads to a significant increase in patient mortality. Due to the low number of reported cases in recent scientific literature and the lack of experience with t...

BACKGROUND The aim of this study is evaluating the correlation of postprandial fullness with chronic gastritis or rapid inflow of gastric content into duodenum, based on double-contrast barium X-ray imaging. METHODS 253 healthy subjects who underwent upper gastrointestinal barium X-ray examination were analyzed. Chronic gastritis was judged from mucosal atrophy and hypertrophic thickened fold...

The compounds BaLn(2)Se(4) (Ln = rare-earth metal = lanthanide = Er, Tm and Yb), namely barium di(erbium/thulium/ytterbium) tetraselenide, crystallize in the orthorhombic space group Pnma in the CaFe(2)O(4) structure type. In this structure type, all atoms possess m symmetry. The Ln atoms are octahedrally coordinated by six Se atoms. A three-dimensional channel structure is formed by the corner...

INTRODUCTION THAT THE history of attempts aimed at introducing barium salts into medicine is both long and chequered is doubtless due to the highly beneficial yet also exceedingly poisonous qualities that were attributed to these compounds. The development of their use reveals an optimism in their healing powers as baseless as it was dangerous; and that more people did not succumb through the e...

We describe a case of bilateral inhalation of barium in an infant following a barium swallow for investigation of dusky spells associated with feeds. A bronchoscopy subsequently revealed the presence of a mid-tracheal tracheo-esophageal cleft. To date, little has been reported on barium aspiration in children and there is no consensus for management. We review the literature on barium aspiratio...

Crystal structures of HgBa2CaCu206 + ~ (Hg1212 ) and HgBa2Ca2Cu308 + a (Hg1223 ) have been determined on single crystals at room temperature conditions by X-ray diffraction techniques. Both tetragonal specimens are isomorphous with compounds in the T1-Ba-Ca-Cu-O system. We observe excess oxygen in both samples on two sites near the z=0 plane: at (1⁄200) and close to (1⁄2, 0.4, 0) but no oxygen ...

A fast ferroelectric phase shifter controlled by an electric field bias is being investigated for high-power fast RF phase shifters to be used for vector modulation. Such a device could find applications in particle accelerators, allowing vector control of the RF power divided and delivered to accelerating cavities from a power amplifier. Bulk ferroelectric materials, particularly those based o...