A Note on CH3OD Spectra, Ground-State Energies and FIR Laser Assignments

Literature data on the CO-stretching and the ground-state torsion-rotation spectra of the CH₃OD isotopic species of methanol have been exploited to extrapolate the ground-state energies to higher J through use of ground-state combination differences derived from the CO-stretching wavenumbers. In particular, the J-dependence has been extended and better defined for the difficult |K| = 0 to 2 E energy level sequences, which are strongly affected by molecular asymmetry. The pattern of the J-dependence is found to be qualitatively well reproduced by a simple 11 × 11 Hamiltonian model incorporating ΔK = ±1 and ±2 off-diagonal asymmetry matrix elements. The results suggest partial reassignment of certain CO-stretching subbands, and the K = 8 and 9 A subbands have been newly identified through clues from reported far-infrared laser (FIRL) emission. Transition combination loops support a number of FIRL line assignments previously proposed, but show that the FIRL system pumped by the 9R(4) CO₂ line must be reassigned.     

The impact of EU policies on energy use in and the evolution of the UK built environment

Energy use in buildings is influenced by a variety of factors in complex ways. Historically, in the UK the efficiency of energy use in buildings has not been a major consideration in their design. Now policy concern with climate change is changing this, because buildings have come to be perceived as the locus of energy use with the highest cost-effective energy savings potential. In the UK, the energy efficiency of the building stock is rather low. The paper focuses largely on energy use in the UK's existing building stock and the two main European Union Directives which affect it: the Energy Performance in Buildings Directive and the Energy Services Directive. The Directives are complex, and there are a number of supporting programmes set up by the European Commission to aid their implementation. Even so, they have been implemented in differing ways in different European countries, and implementation remains patchy. The Directives have the potential to be a major influence on the evolution of the UK's built environment, but their effect will depend on the details of the Directives’ implementation and enforcement, many of which are not yet clear.     

The use of 18O as a tracer to study the growth mechanisms of oxide scales

A nuclear technique for the determination of ¹⁸O concentration as a function of depth is described. Examples are given of the application of this technique to studies of growth mechanisms of oxide scales.     

Formation of acetaldehyde from threonine by lactic acid bacteria.

Group N streptococci were found to cleave threonine to form acetaldehyde and glycine. Threonine aldolase, the enzyme catalysing this reaction, was found in all strains except Streptococcus cremoris Z8, an organism which had been shown previously to have a nutritional requirement for glycine. The enzyme was strongly inhibited by glycine and cysteine. The inhibition showed characteristics of allosteric inhibition and was pH-dependent. Inhibition by glycine, but not by cysteine, was highly specific. Analogues and derivatives of cysteine which contained a thiol group and a free amino group inhibited the activity of threonine aldolase. The presence of a carboxyl group was not necessary for inhibition. The cleavage of threonine by whole-cell suspensions was stimulated by either an energy source to aid transport or by rendering the cells permeable to substrate with oleate. Threonine did not appear to be degraded by enzymes other than threonine aldolase, as threonine dehydratase activity was low and NAD- and NADP-dependent threonine dehydrogenases were absent.