The crystal structure of LiMgAlD6 from combined neutron and synchrotron X-ray powder diffraction

LiMgAlH₆ is the intermediate phase when LiMg(AlH₄)₃ is heated. It contains 9.4 wt.% hydrogen, of which 4.8 wt.% is released during the decomposition step to MgH₂ and LiH. Deuterated LiMgAlD₆ was prepared by heat-treating LiMg(AlD₄)₃ at 130 °C. Powder neutron and synchrotron X-ray diffraction patterns were measured and the structure was refined using the Rietveld technique on both patterns simultaneously. LiMgAlD₆ crystallizes in the trigonal space group P321 with a = 7.9856(4) Å and c = 4.3789(3) Å. The structure consists of isolated AlD₆ octahedra connected through octahedrally coordinated Mg- and Li-atoms.     

UTRA/FDD RF Transceiver Requirements

Unified RF requirements are derived for an UMTS Terrestrial RadioAccess/Frequency Division Duplex (UTRA/FDD) compliant mobile transceiver. Aset of transceiver requirements are proposed with consideration to systemissues including duplex aspects. From these design-compatible requirements areproposed for each functional block in the transceiver.     

Model calculations on a flat-plate solar heat collector with integrated solar cells

A detailed physical model of a hybrid photovoltaic/thermal system is proposed, and algorithms for making quantitative predictions regarding the performance of the system are presented. The motivation for the present work is that solar cells act as good heat collectors and are fairly good selective absorbers. Additionally, most solar cells increase their efficiency when heat is drawn from the cells. The model is based on an analysis of energy transfers due to conduction, convection and radiation and predicts the amount of heat that can be drawn from the system as well as the (temperature-dependent) power output. Special emphasis is laid on the dependence of the fin width to tube diameter ratio. We attribute values to the model parameters, and show that hybrid devices are interesting concerning system efficiency as is also confirmed by previous experiments. Possible applications of such systems are also proposed.     

Acoustic beam position monitor for microanalysis of particles in the 10 nm range in a TEM-SCAN system

This paper describes the principle and use of a simple equipment which makes it possible to keep the electron beam in the centre of a small particle analysed by X-ray microanalysis in a STEM system. A deviation from the correct beam position introduced by drift or other deficiencies is monitored by an audible change in a sound frequency and corrected for by a convenient manual operation.     

Telset,the Finnish viewdata

The Telset system has been under development since 1975. Similar to Prestel, the system's database, for example, has the same three-way division into News-Telset, Home Telset and Business Telset as the UK system. The software is developed to run under the control of the RSX-11 V3 executive; the latter being a versatile real-time events. At the same time, however, the executive allows the system to carry out software development and run less urgent programs in parallel with the real-time application.     

Interpretation and code generation based on intermediate languages

The possibility of supporting high level languages through intermediate languages to be used for direct interpretation and as intermediate forms in compilers is investigated. An accomplished project in the construction of an interpreter and a code generator using one common intermediate form is evaluated. The subject is analysed in general, and a proposal for an improved design scheme is given.     

Antineuraminidase serum antibodies in natural influenza A and immunization with influenza vaccines

Parallel HI and virus-elution-from-erythrocytes-inhibition (a simplified method for titration of neuraminidase antibody) tests were used for examinations of 1117 blood serum specimens from 440 adults and children under study, 5250 single serum specimens from healthy subjects from birth to 65 years of age, 38 paired serum specimens from children who experienced influenza A/Texas/1/77 disease in the epidemic of 1979-1980, and 590 paired serum specimens from subjects immunized with influenza vaccines. In 7%-23% of influenza patients and immunized subjects antibody rise was observed to only one of the influenza A virus surface antigens, hemagglutinin or neuraminidase. The protective activity of antibody to influenza A virus neuraminidase was as good as that of antihemagglutinins. Both kinds of antibody interacted in protection against the disease. Antineuraminidase antibody was found to affect the decrease in severity of the infectious process in natural infection with influenza A. The formation of immunological memory in the system of synthesis of antihemagglutinins and antineuraminidase antibodies was shown to have features in common. The pattern of heterologous immune responses in immunized subjects and patients with influenza showed all antigenic varieties of neuraminidase N2 as well as neuraminidases N1 and N2 to share common cross-reacting determinants.     

Oscillation limits for weighted residual methods applied to convective diffusion equations

Convection–diffusion equations are difficult to solve when the convection term dominates because most solution methods give solutions which oscillate in space. Previous criteria based on the one-dimensional convection–diffusion equation have shown that finite difference and Galerkin (linear or quadratic basis functions) will not give oscillatory solutions provided the Peclet number times the mesh size (Pe Δx) is below a critical value. These criteria are based on the solution at the nodes, and ensure that the nodal values are monotone. Similar criteria are developed here for other methods: quadratic Galerkin with upwind weighting, cubic Galerkin, orthogonal collocation on finite elements with quadratic, cubic or quartic polynomials using Lagrangian interpolation, cubic or quartic polynominals using Hermite interpolation, and the method of moments. The nodal values do not oscillate for collocation or moments methods with Hermite cubic polynomials regardless of the value of Pe Δx. A new criterion is developed for all methods based on the monotonicity of the solutions throughout the domain. This criterion is more restrictive than one based only on the nodal values. All methods that are second order (Δx²) or better in truncation error give oscillatory solutions (based on the entire domain) unless Pe Δx is below a critical value. This value ranges from 2 for finite difference methods to 4·6 for Hermite, quartic, collocation methods.     

Cu exposure under field conditions coselects for antibiotic resistance as determined by a novel cultivation-independent bacterial community tolerance assay

Environmental reservoirs of antibiotic resistance are important to human health, and recent evidence indicates that terrestrial resistance reservoirs have expanded during the antibiotic era. Our aim was to study the impact of Cu pollution as a selective driver for the spread of antibiotic resistance in soil. Bacteria were extracted from a well-characterized soil site solely contaminated with CuSO? more than 80 years ago and from a corresponding control soil. Pollution-induced bacterial community tolerance (PICT) to Cu and a panel of antibiotics was determined by a novel cultivation-independent approach based on [3H]bromodeoxyuridine (BrdU) incorporation into DNA and by resistance profiling of soil bacterial isolates on solid media. High Cu exposure selected for Cu-tolerant bacterial communities but also coselected for increased community-level tolerance to tetracycline and vancomycin. Cu-resistant isolates showed significantly higher incidence of resistance to five out of seven tested antibiotics (tetracycline, olaquindox, nalidixic acid, chloramphenicol, and ampicillin) than Cu-sensitive isolates. Our BrdU-PICT data demonstrate for the first time that soil Cu exposure coselects for resistance to clinically important antibiotics (e.g., vancomycin) at the bacterial community-level. Our study further indicates that Cu exposure provides a strong selection pressure for the expansion of the soil bacterial resistome.