[en] An overview of new electricity trading arrangements in the UK and the mechanism of licence-exempt generation under the New Electricity Trading Arrangements (NETA) is presented as a collection of bullet point lists. The key elements of the new trading arrangements (eg energy accounts and imbalance mechanisms), contracts between generators and suppliers, the basic elements of NETA, the concept of licence-exempt generation, exemptible generation and BM units, aggregation and consolidation, tools for imbalance risk management such as meter volume reallocation notification (MVRN) and energy contract volume notification (ECVN), the operation of MVRNs and ECVNs, tools for licence-exempt generation, allocation of imbalance risks, and contact details for NETA programme support are covered by these summary lists

[en] Laminar flow instability (LFI) is a rarely encountered phenomenon, occurring in gaseous heated channels with high exit-to-inlet temperature ratios and a laminar Reynolds Number at the channel exit, as may be experienced in a nuclear rocket. Analytical techniques were developed and programmed for parametric evaluation that had been previously validated by comparison with available experimental data. The four types of transients associated with LFI are described in terms of the governing equations. Parametric evaluations of solid core prismatic and particle bed fuel configurations were made to determine their sensitivities to LFI from temperature ratio, flow rate, orificing, transition Reynolds Number, pressure level, presence of an exit sonic nozzle, power density and heat flux shape. The flow rate at the point of neutral stability and the growth rate of the excursive transient are calculated. The full power design point and the cooldown phases of operation were both evaluated

[en] Differential cross sections for the reaction D+H₂→HD+H were measured with a novel crossed molecular beam technique, in which a pulse of energetic D atoms is formed by 193 nm photolysis of D₂S and crossed with a pulse of H₂ at a variable intersection angle. Speed distributions of the product HD, measured by time-of-flight to a mass spectrometer detector, show clearly resolved peaks for v = 0 and v = 1 at center-of-mass scattering angles near 180⁰, for an initial relative kinetic energy of 0.95 eV. Analysis of the data by computer simulation of the experiment yields a v = 0/v = 1 population ratio of 5.1, and average rotational energies of 0.26 eV in V = 0 and 0.11 eV in v = 1

[en] Several families of multivariable, biorthogonal, partly continuous and partly discrete, Wilson polynomials are presented. These yield limit cases that are purely continuous in some of the variables and purely discrete in the others, or purely discrete in all the variables. The latter are referred to as the multivariable biorthogonal Racah polynomials. Interesting further limit cases include the multivariable biorthogonal Hahn and dual Hahn polynomials

No abstract available

[en] The concept of tissue-maximum ratios (TMR) as a basis of dose computations has posed problems when applied to the whole range of clinically used megavoltage beams. Another problem is the definition of scatter-maximum ratio (SMR) which assumes a value of zero at the depth of maximum dose. This paper describes new methods of measuring collimator and phantom scatter correction factors. The definitions of TMR and SMR are modified in order to compute phantom scatter at any depth, including depth of maximum dose. The revised concept is basic and general enough that it can be applied to x-ray beams of any energy, fields of any shape and isocentric as well as non-isocentric modes of treatment

[en] The in vitro precipitation of the metastable CaCO₃ phases aragonite and vaterite in the presence of leucine is investigated. Under normal conditions, the production of CaCO₃ via the hydrolysis of urea method favours the formation of regular needle-like aragonite crystals, with very minor quantities of vaterite and calcite. However in the presence of leucine, aragonite forms highly branched structures and the vaterite yield is increased, forming flower-like clusters composed of nano-thin sheets. Both the degree of aragonite branching and the occurrence, regularity of shape and number of vaterite 'petals' increases with leucine concentration. The two phases exhibit different variations in their crystallographic parameters with increasing concentration, while the molecular structure appears unaffected.

[en] 1. Determination of Metal Residues in Active Pharmaceutical Ingredients According to Current Legislation by Using XRF Spectrometry. Safety and efficacy of pharmaceuticals are two fundamental issues of importance in drug therapy. Therefore, the determination of potential impurities in different stages of the manufacturing processes, and especially in the final product, is necessary to prevent potential risk to human health. Metals can be introduced in the active pharmaceutical ingredients (API) through different sources (raw materials, reagents, catalysts, reactors, etc) and, consequently, they are potential impurities in the drug substances and are routinely monitored. 2. Application of XRF Spectrometry in Phytoremediation Activities Around Mining Areas. In the last decade, the use of plants for the stabilization (phytostabilization) and clean-up (phytoremediation) of metal contaminated environments has gained popularity among government agencies worldwide, as alternate or complementary cost-effective non-invasive technology to the engineering based remediation methods. In view of the considerable number of analyses necessary in phytoremediation and plant biology studies, it is important that the analytical procedures used for elemental determination in plant tissues should be fast and cheap, with simple sample preparation, and of adequate accuracy and precision. Last years, we have developed several analytical methodologies, using diverse configurations of XRF spectrometers (EDXRF, WDXRF, HE-P-EDXRF), to determine elemental composition of vegetation grown in mining areas. Recently, in collaboration with a research group from the Department of Chemical Engineering, Agriculture and Food Technology of the University of Girona (Spain), we have studied the possibilities and limitations of a low-cost benchtop energy dispersive X ray fluorescence (EDXRF) instrument to be employed as analytical technique for studying the potential use of sunflowers (Helianthus annuus) for the phytoremediation of an abandoned Pb/Zn mining area located at the North East of Spain. 3. Compositional Characterization of Ancient Coins by Means of XRF Instrumentation. During the last years, amongst other activities, the Laboratory of X ray Analytical Applications (LARX) has been involved in the analytical applications of XRF spectrometry in the field of Cultural Heritage objects. In the last two years, within the framework of a joined project between LARX and the Catalonian Numismatic Department (GNC) at the National Museum of Fine Arts of Catalonia (MNAC, Barcelona) were undertaken

[en] Rectified diameters and albedo estimates of 1517 main-belt asteroids selected from IRAS and the Mid-Course Space Experiment asteroid photometry catalogs are derived from updated infrared thermal models, the Standard Thermal Model and the Near-Earth Asteroid Thermal Model (NEATM), and Monte Carlo simulations, using new Minor Planet Center compilations of absolute magnitudes (H values) constrained by occultation- and radar-derived parameters. The NEATM approach produces a more robust estimate of albedos and diameters, yielding albedos of p_v (NEATM mean) =0.081 ± 0.064. The asteroid beaming parameter (η) for the selected asteroids has a mean value of 1.07 ± 0.27, and the smooth distribution of η suggests that this parameter is independent of asteroid properties such as composition. No trends in η due to size-dependent rotation rates are evident. Comparison of derived values of η as a function of taxonomic type indicates that the beaming parameter values for S- and C-type asteroids are identical within the standard deviation of the population of beaming parameters.

[en] The effects of elevated concentrations of atmospheric tropospheric ozone (O₃) on DNA damage in five trembling aspen (Populus tremuloides Michx.) clones growing in a free-air enrichment experiment in the presence and absence of elevated concentrations of carbon dioxide (CO₂) were examined. Growing season mean hourly O₃ concentrations were 36.3 and 47.3 ppb for ambient and elevated O₃ plots, respectively. The 4th highest daily maximum 8-h ambient and elevated O₃ concentrations were 79 and 89 ppb, respectively. Elevated CO₂ averaged 524 ppm (+150 ppm) over the growing season. Exposure to O₃ and CO₂ in combination with O₃ increased DNA damage levels above background as measured by the comet assay. Ozone-tolerant clones 271 and 8L showed the highest levels of DNA damage under elevated O₃ compared with ambient air; whereas less tolerant clone 216 and sensitive clones 42E and 259 had comparably lower levels of DNA damage with no significant differences between elevated O₃ and ambient air. Clone 8L was demonstrated to have the highest level of excision DNA repair. In addition, clone 271 had the highest level of oxidative damage as measured by lipid peroxidation. The results suggest that variation in cellular responses to DNA damage between aspen clones may contribute to O₃ tolerance or sensitivity. - Ozone tolerant clones and sensitive Populus tremuloides clones show differences in DNA damage and repair.