Development of fuel cell electrodes, Electrode improvement and life testing, tasks 1 and 3 Final report, 30 Jun. 1966 - 30 Apr. 1968

Volt-ampere characteristics improvement and life testing of electrodes for hydrogen oxygen fuel cell

Professionalism and the Millbank Tendency: The Political Sociology of New Labour's employees

This article analyses party employees, one of the most under-researched subjects in the study of British political parties. We draw on a blend of quantitative and qualitative data in order to shed light on the social and political profiles of Labour Party staff, and on the question of their professionalisation. The latter theme is developed through a model derived from the sociology of professions. While a relatively limited proportion of party employees conform to the pure ideal-type of professionalism, a considerably greater number manifest enough of the core characteristics of specialisation, commitment, mobility, autonomy and self-regulation to be reasonably described as 'professionals in pursuit of political outcomes'

17O NMR study of q=0 spin excitations in a nearly ideal S=1/2 1D Heisenberg antiferromagnet, Sr2CuO3, up to 800 K

We used 17O NMR to probe the uniform (wavevector q=0) electron spin excitations up to 800 K in Sr2CuO3 and separate the q=0 from the q=\pm\pi/a staggered components. Our results support the logarithmic decrease of the uniform spin susceptibility below T ~ 0.015J, where J=2200 K. From measurement of the dynamical spin susceptibility for q=0 by the spin-lattice relaxation rate 1/T_{1}, we demonstrate that the q=0 mode of spin transport is ballistic at the T=0 limit, but has a diffusion-like contribution at finite temperatures even for T << J.Comment: Submitted to Phys. Rev. Lett. 4 pages, 4 figure

Recruitment, growth and mortality of an Antarctic hexactinellid sponge, Anoxycalyx joubini.

Polar ecosystems are sensitive to climate forcing, and we often lack baselines to evaluate changes. Here we report a nearly 50-year study in which a sudden shift in the population dynamics of an ecologically important, structure-forming hexactinellid sponge, Anoxycalyx joubini was observed. This is the largest Antarctic sponge, with individuals growing over two meters tall. In order to investigate life history characteristics of Antarctic marine invertebrates, artificial substrata were deployed at a number of sites in the southern portion of the Ross Sea between 1967 and 1975. Over a 22-year period, no growth or settlement was recorded for A. joubini on these substrata; however, in 2004 and 2010, A. joubini was observed to have settled and grown to large sizes on some but not all artificial substrata. This single settlement and growth event correlates with a region-wide shift in phytoplankton productivity driven by the calving of a massive iceberg. We also report almost complete mortality of large sponges followed over 40 years. Given our warming global climate, similar system-wide changes are expected in the future

Flipping for Food: The Use of a Methane Seep by Tanner Crabs (Chionoecetes tanneri)

Methane seep habitats are widespread chemosynthesis-based ecosystems that span continental margins and interact with surrounding marine systems. With many of these habitats occurring below 200 m, seeps can serve as an important source of nutrients in otherwise food limited deep-sea environments. However, the potential for marauding megafauna to assimilate seep derived nutrition has been difficult to quantify. Here, we provide the first evidence of a commercially harvested species, Chionoecetes tanneri (tanner crab), assimilating chemosynthetic production. Although bulk isotope analysis of C. tanneri tissue indicated no quantifiable incorporation of seep-derived carbon or sulfur (mean δ13C, −18.5‰; mean δ34S, 19.5‰), depletions in 13C (δ13C as light as −38.8‰) were noted in fatty acid (FA) compounds. In addition, diagnostic biomarkers for seep bacteria, including 16:1ω6 and 18:1ω8c FA's, were found to have been assimilated by C. tanneri. Futher supporting a trophic link between the seep and the C. tanneri, seep associated bacteria and archaea were, in certain cases, the dominant taxa in the gut contents of the crabs. This work provides the first insights into a link between seep production and deep-sea ecosystem services, specifically fisheries production. In addition, it reveals a methodological bias that could exist in some trophic studies where bulk isotopes under-represent the role of seep nutrition in the diet of marauding animals

Development of Silicon-Modified 48 Wt. % U-Al Alloys for Aluminum Plate-Type Fuel Elements

The casting procedures, mechanical working characteristics, composite fuel plate fabrication, and fuel element assembly methods for a nominal 48 wt.% U- 3 wt.% Si -AP alloy are examined. It was found that localized clad thinning, resulting from dogboning'' of the fuel alloy, is essentially eliminated in composite Plates when this alloy is used in combination with 5154 Al frames and 1100 Al covers. However, fuel component dimensions are difficult to maintain within commonly accepted tolersnces in the brazing prccess because of the marked differences in the thermal expansion of the fuel alloy and the containment materials. The mechanical properties, irradiation studies, corrosfon testing, pneumatic pressure testing, and chemical reprocessing of the Si-modified alloy are also discussed. (auth

Polyamine stress at high pH in Escherichia coli K-12

BACKGROUND: Polyamines such as spermine and spermidine are required for growth of Escherichia coli; they interact with nucleic acids, and they bind to ribosomes. Polyamines block porins and decrease membrane permeability, activities that may protect cells in acid. At high concentrations, however, polyamines impair growth. They impair growth more severely at high pH, probably due to their increased uptake as membrane-permeant weak bases. The role of pH is critical in understanding polyamine stress. RESULTS: The effect of polyamines was tested on survival of Escherichia coli K-12 W3110 in extreme acid or base (pH conditions outside the growth range). At pH 2, 10 mM spermine increased survival by 2-fold, and putrescine increased survival by 30%. At pH 9.8, however, E. coli survival was decreased 100-fold by 10 mM spermine, putrescine, cadaverine, or spermidine. At pH 8.5, spermine decreased the growth rate substantially, whereas little effect was seen at pH 5.5. Spermidine required ten-fold higher concentrations to impair growth. On proteomic 2-D gels, spermine and spermidine caused differential expression of 31 different proteins. During log-phase growth at pH 7.0, 1 mM spermine induced eight proteins, including PykF, GlpK, SerS, DeaD, OmpC and OmpF. Proteins repressed included acetate-inducible enzymes (YfiD, Pta, Lpd) as well as RapA (HepA), and FabB. At pH 8.5, spermine induced additional proteins: TnaA, OmpA, YrdA and NanA (YhcJ) and also repressed 17 proteins. Four of the proteins that spermine induced (GlpK, OmpA, OmpF, TnaA) and five that were repressed (Lpd, Pta, SucB, TpiA, YfiD) show similar induction or repression, respectively, in base compared to acid. Most of these base stress proteins were also regulated by spermidine, but only at ten-fold higher concentration (10 mM) at high pH (pH 8.5). CONCLUSION: Polyamines increase survival in extreme acid, but decrease E. coli survival in extreme base. Growth inhibition by spermine and spermidine requires neutral or higher pH. At or above pH 7, spermine and spermidine regulate specific proteins, many of which are known to be regulated by base stress. High pH amplifies polyamine stress; and naturally occurring polyamines may play an important role in base stress

63Cu NQR evidence of dimensional crossover to anisotropic 2d regime in S= 1/2 three-leg ladder Sr2Cu3O5

We probed spin-spin correlations up to 725 K with 63Cu NQR in the S= 1/2 three-leg ladder Sr2Cu3O5. We present experimental evidence that below 300 K, weak inter-ladder coupling causes dimensional crossover of the spin-spin correlation length \xi from quasi-1d (\xi ~ 1/T) to anisotropic 2d regime (\xi \~ exp[2\pi\rho_{s}/T], where 2\pi\rho_{s} = 290 +/- 30 K is the effective spin stiffness). This is the first experimental verification of the renormalized classical behavior of the anisotropic non-linear sigma model in 2d, which has been recently proposed for the striped phase in high T_{c} cuprates.Comment: 4 pages, 3 figure

Development of high-temperature ferromagnetism in SnO2 and paramagnetism in SnO by Fe doping

We report the development of room-temperature ferromagnetism in chemically synthesized powder samples of Sn1−xFexO2 (0.005≤ x ≤0.05) and paramagnetic behavior in an identically synthesized set of Sn1−xFexO. The ferromagnetic Sn0.99Fe0.01O2 showed a Curie temperature TC=850 K, which is among the highest reported for transition-metal-doped semiconductor oxides. With increasing Fe doping, the lattice parameters of SnO2 decreased and the saturation magnetization increased, suggesting a strong structure-magnetic property relationship. When the Sn0.95Fe0.05O2 was prepared at different temperatures between 200 and 900 °C, systematic changes in the magnetic properties were observed. Combined Mössbauer spectroscopy and magnetometry measurements showed a ferromagnetic behavior in Sn0.95Fe0.05O2 samples prepared at and above 350°C, but the ferromagnetic component decreased gradually as preparation temperature approached 600 °C. All Sn0.95Fe0.05O2 samples prepared above 600 °C were paramagnetic. X-ray photoelectron spectroscopy, magnetometry, and particle induced x-ray emission studies showed that the Fe dopants diffuse towards the surface of the particles in samples prepared at higher temperatures, gradually destroying the ferromagnetism. Mössbauer studies showed that the magnetically ordered Fe3+ spins observed in the Sn0.95Fe0.05O2 sample prepared at 350 °C is only ~24% of the uniformly incorporated Fe3+. No evidence of any iron oxide impurity phases were detected in Sn1−xFexO2 or Sn1−xFexO, suggesting that the emerging magnetic interactions in these systems are most likely related to the properties of the host systems SnO2 and SnO, and their oxygen stoichiometry

Measuring Positive Childhood Experiences: Testing the structural and predictive validity of the Health Outcomes from Positive Experiences (HOPE) framework

OBJECTIVE: Positive childhood experiences (PCEs), that occur within secure and nurturing social environments, are fundamental to healthy physical, socio-emotional, and cognitive development. However, reliable measures of these experiences are not yet widely available. We used data from the Longitudinal Study of Australian Children (LSAC) to empirically represent and psychometrically evaluate three primary domains of PCEs defined within the Health Outcomes from Positive Experiences (HOPE) framework, specifically: (1) nurturing and supportive relationships; (2) safe and protective environments and; (3) constructive social engagement and connectedness. METHODS: LSAC is a nationally representative cohort that has followed young Australians from birth since 2004. LSAC data were used to represent the three primary HOPE-PCEs domains (0-11 years) across four interrelated PCEs constructs: (1) positive parenting, (2) trusting and supportive relationships, (3) supportive neighbourhood and home learning environments, and (4) social engagement and enjoyment. Confirmatory factor analysis was used to test the proposed four-factor structure. Predictive validity was examined through associations with mental health problems and academic difficulties at 14-15 years. RESULTS: The four-factor structure was supported by empirical data at each time point. Higher exposure to PCEs across each domain was associated with lower reporting of mental health problems (β=-0.20 to -2.05) and academic difficulties (β=-0.01 to -0.13) in adolescence. CONCLUSIONS: The four LSAC-based HOPE-PCEs have sufficient internal coherence and predictive validity to offer a potentially useful way of conceptualizing and measuring PCEs in future cohort studies and intervention trials aiming to enhance understanding of, and mitigate the negative impacts of, adverse childhood experiences