Manufacture and measurement of combinatorial libraries of dielectric ceramics: Part II. Dielectric measurements of Ba1−xSrxTiO3 libraries

Applying combinatorial methods to materials science offers the opportunity to accelerate the discovery of more efficient dielectric ceramics. High-throughput methods have the potential to investigate the effects of a wide range of dopants on the dielectric properties, and to optimise existing systems, encouraging the short innovation cycles that the communications technology industry requires. The London University Search Instrument (LUSI) is a fully automated, high-throughput combinatorial robot that has the potential capability to produce large numbers of sintered bulk ceramic samples with varying composition in 1 day, as combinatorial libraries on alumina substrates. Ba_1−xSr_xTiO₃ (BST) libraries were produced by LUSI as a proof-of-principle, with x = 0–1 in steps of 0.1, and fired to 1350 and 1400 °C for 1 h. Part I of this paper described the manufacture and physical characterisation of BST libraries, showing a regular change in composition with x across the libraries. In this second part, the dielectric properties of BST libraries produced by LUSI are assessed at frequencies between 100 Hz and 1 MHz, and at temperatures between 150 and 500 K. Local piezoelectric properties were also characterised by scanning probe microscope (SPM). All measurements showed evidence of a clear functional gradient varying with x across the library, with measured _r corresponding to expected values for BST.     

Heterogeneous distribution of chain mobility in nascent UHMWPE in the less entangled state

The structure of chain entanglements in the solid state is important for revealing the relationship of structure and properties of polyolefin. In this work, low-field solid-state ¹H NMR is used to study the chain dynamics of ultra-high molecular weight polyethylene (UHMWPE) in the solid state. It has been found that the relaxation distribution, analyzed by a multi-exponential inversion program, is an effective method to characterize the heterogeneous chain mobility. It is evidenced from the results that the UHMWPE in a less entangled state presents an obviously heterogeneous distribution of chain mobility in the non-crystalline phase, corresponding to its heterogeneous distribution of entangled points. In comparison, the commercial UHMWPE with a large number of entanglements shows a much more uniform mobility of the non-crystalline components. This heterogeneous distribution of chain mobility becomes even more critical after annealing the samples below the melting point, especially for the less entangled UHMWPE.     

Numerical Studies of Features of Wing Flow in the Buffeting Mode

Technical Physics Letters - A numerical method for solving the Reynolds equations for the problem of the flow around a rectangular wing in the buffeting mode is validated and the flow around an...     

On Feasibility of Population Inversion Between the Quantum Confinement Levels in Quantum Wells Under Interband Photoexcitation

Journal of Infrared, Millimeter, and Terahertz Waves - We discuss a possibility of achieving population inversion and the associated generation of stimulated terahertz radiation employing...     

A New Method for Removing and Binding Th(IV) and Other Radionuclides by In Situ Formation of a Sorbent Based on Fibrous Cerium(IV) Hydrogen Phosphate in Liquid Media

A novel method was suggested for removing Th(IV) and other radionuclides from liquid media. The method consists in formation of the sorbent, fibrous cerium(IV) hydrogen phosphate, directly in the aqueous solution. The sorbent shows the highest performance in the removal of Th(IV). The sorbent can also serve as a host material for the subsequent Th(IV) disposal.     

Hepatic manifestations of Wilson's disease: frequency and pattern in Saudi patients

Seven symptomatic patients with Wilson's disease have so far been diagnosed at King Khalid University Hospital (KKUH), Riyadh, over the last six years. On family screening, another three asymptomatic patients were found to be affected. Five of the symptomatic patients had clinical features of liver disease on initial presentation and was preceded by renal dysfunction in another patient. The remaining patient presented with neurological features. Six patients had Kayser-Fleisher ring. Abnormal liver function tests were found in half of the patients. Ceruloplasmin was reduced in 7 of 10 patients. Serum copper and urinary copper estimations were most useful diagnostic laboratory tests. Morphological alteration was found in all 9 patients who had a percutaneous liver biopsy. All patients were treated initially with D-penicillamine and clinical response was noted in seven, of whom one developed neurological manifestations while receiving the treatment. D-penicillamine was replaced by zinc sulfate in 3 patients who developed thrombocytopenia. The data suggest that Wilson's disease may not be rare in Saudi Arabia. For early detection and prompt treatment, the disease should be suspected under appropriate clinical circumstances especially in young patients with liver diseases. Close relatives of such index patients should be routinely screened.     

The mechanisms of uncognizable perception controlling human behavior

The task of the study was to determine the influence of emotional-motivational sphere on the phenomenon of out-of-logic mental activity. An accepted in the laboratory model of the recognition of a hidden image double image pictures was used. Recorded multichannel EEG was analysed by the method of computation of coefficients of community elaborated in the laboratory. The results of computation were presented in a form of a stereometric map. The obtained results testify to the fact that the emotional-motivational processes influence the mechanism of the out-of-logic form of decision making. At the out-of-logic form of decision making a subjective evaluation of results dominates being reflected in the character of the spatial distribution of coefficient of community.     

Invasive malignant fibrous histiocytoma in a cow

An invasive malignant fibrous histiocytoma associated with the left cornual process, and causing lysis of the frontal bone, was diagnosed in a cow. The mass compressed the left cerebral hemisphere focally and extended into the frontal sinus and ethmoid and nasal turbinates. It was composed of pleomorphic to spindle-shaped cells with ultra-structural evidence of fibroblastic, myofibroblastic, and fibrohistiocytic differentiation. Trauma and chronic inflammation may be predisposing factors for development of neoplasia in cattle.     

An alpha-mercaptoacrylic acid derivative is a selective nonpeptide cell-permeable calpain inhibitor and is neuroprotective

Overactivation of calcium-activated neutral protease (calpain) has been implicated in the pathophysiology of several degenerative conditions, including stroke, myocardial ischemia, neuromuscular degeneration, and cataract formation. Alpha-mercaptoacrylate derivatives (exemplified by PD150606), with potent and selective inhibitory actions against calpain, have been identified. PD150606 exhibits the following characteristics: (i) Ki values for mu- and m-calpains of 0.21 microM and 0.37 microM, respectively, (ii) high specificity for calpains relative to other proteases, (iii) uncompetitive inhibition with respect to substrate, and (iv) it does not shield calpain against inactivation by the active-site inhibitor trans-(epoxysuccinyl)-L-leucyl-amido-3-methylbutane, suggesting a nonactive site action for PD150606. The recombinant calcium-binding domain from each of the large or small subunits of mu-calpain was found to interact with PD150606. In low micromolar range, PD15O6O6 inhibited calpain activity in two intact cell systems. The neuroprotective effects of this class of compound were also demonstrated by the ability of PD150606 to attenuate hypoxic/hypoglycemic injury to cerebrocortical neurons in culture and excitotoxic injury to Purkinje cells in cerebellar slices.