Thermal conductivity of gaseous and liquid hydrogen

Normal and para-hydrogen conductivity measurements at temperatures from 200 to 17 deg K, at densities up to 2.6 times critical density, and at pressures to 15 MN/sq m are made. Using new calorimeter, data are analyzed as functions of density at fixed temperatures and of temperature at fixed densitie

Private Standardization in Public International Lawmaking

The interplay between market forces and legal compulsion is as old as the Code of Ur-Nammu, yet the financial incentives for social conformity have never been more patent. In what may be its most ambitious effort yet, the International Organization for Standardization (ISO) recently launched the International Standard ISO 26000:2010 (ISO 26000) on social responsibility (SR), a new voluntary standard providing guidance to any organization on good practices in SR.2 ISO 26000 provides wide-ranging guidance on areas of social and environmental conduct that are relevant to public policy and regulation. The single ISO-branded package offers a new product that markets publicly developed legal norms for commercial use. It operates through a system of voluntary compliance based on market reputation for SR and is largely delinked from public regulatory mechanisms. This Article explores the emerging role of private international standardization in addressing, on a global scale, public interests and issues traditionally addressed through international public law and policy. It assesses the advantages and limitations of such private action, using the development and launch of ISO 26000 as an example. The Article assesses the purpose for and process of developing ISO 26000. It reviews the factors that motivated ISO\u27s decision to develop such a standard and examines the search for legitimacy and accountability in the multistakeholder process leading to its final submission to ISO member bodies for a vote. The analysis focuses in particular on the interaction between private and public actors, including governments and international organizations, and specifically on ISO\u27s cooperation with the International Labour Organization (ILO), the specialized U.N. agency whose mandate is to establish and supervise international labor standards, one of the subjects with which ISO 26000 was integrally concerned

Encoding monotonic multiset preferences using ci-nets1

CP-nets and their variants constitute one of the main AI approaches for specifying and reasoning about preferences. CI-nets, in particular, are a CP-inspired formalism for representing ordinal preferences over sets of goods, which are typically monotonic. Considering also that goods often come in multisets rather than sets, a natural question is whether CI-nets can be used more or less directly to encode preferences over multisets. We here provide some initial ideas about this by Ąrst presenting a straight-forward generalisation of CI-nets to multisets with bounded multiplicities, which we show can be eiciently reduced to CI-nets. Second, we sketch a proposal for a further generalisation which allows for encoding preferences over multisets with unbounded multiplicities, yet characterise reasoning in this framework in terms of the Ąrst. We Ąnally show a potential use of our generalisation of CI-nets for personalization in a recent system for evidence aggregation

Heat flux microsensor measurements and calibrations

A new thin-film heat flux gage has been fabricated specifically for severe high temperature operation using platinum and platinum-10 percent rhodium for the thermocouple elements. Radiation calibrations of this gage were performed at the AEDC facility over the available heat flux range (approx. 1.0 - 1,000 W/cu cm). The gage output was linear with heat flux with a slight increase in sensitivity with increasing surface temperature. Survivability of gages was demonstrated in quench tests from 500 C into liquid nitrogen. Successful operation of gages to surface temperatures of 750 C has been achieved. No additional cooling of the gages is required because the gages are always at the same temperature as the substrate material. A video of oxyacetylene flame tests with real-time heat flux and temperature output is available

Post-critical set and non existence of preserved meromorphic two-forms

We present a family of birational transformations in $CP_2$ depending on two, or three, parameters which does not, generically, preserve meromorphic two-forms. With the introduction of the orbit of the critical set (vanishing condition of the Jacobian), also called ``post-critical set'', we get some new structures, some "non-analytic" two-form which reduce to meromorphic two-forms for particular subvarieties in the parameter space. On these subvarieties, the iterates of the critical set have a polynomial growth in the \emph{degrees of the parameters}, while one has an exponential growth out of these subspaces. The analysis of our birational transformation in $CP_2$ is first carried out using Diller-Favre criterion in order to find the complexity reduction of the mapping. The integrable cases are found. The identification between the complexity growth and the topological entropy is, one more time, verified. We perform plots of the post-critical set, as well as calculations of Lyapunov exponents for many orbits, confirming that generically no meromorphic two-form can be preserved for this mapping. These birational transformations in $CP_2$, which, generically, do not preserve any meromorphic two-form, are extremely similar to other birational transformations we previously studied, which do preserve meromorphic two-forms. We note that these two sets of birational transformations exhibit totally similar results as far as topological complexity is concerned, but drastically different results as far as a more ``probabilistic'' approach of dynamical systems is concerned (Lyapunov exponents). With these examples we see that the existence of a preserved meromorphic two-form explains most of the (numerical) discrepancy between the topological and probabilistic approach of dynamical systems.Comment: 34 pages, 7 figure

Green Currents for Meromorphic Maps of Compact K\"ahler Manifolds

We consider the dynamics of meromorphic maps of compact K\"ahler manifolds. In this work, our goal is to locate the non-nef locus of invariant classes and provide necessary and sufficient conditions for existence of Green currents in codimension one.Comment: Statement of Theorem 1.5 is slightly improved. Proposition 5.2 and Theorem 5.3 are adde

Interfacial charge rearrangement and intermolecular interactions: Density-functional theory study of free-base porphine adsorbed on Ag(111) and Cu(111)

We employ dispersion-corrected density-functional theory to study the adsorption of tetrapyrrole 2H-porphine (2H-P) at Cu(111) and Ag(111). Various contributions to adsorbate-substrate and adsorbate-adsorbate interactions are systematically extracted to analyze the self-assembly behavior of this basic building block to porphyrin-based metal-organic nanostructures. This analysis reveals a surprising importance of substrate-mediated van der Waals interactions between 2H-P molecules, in contrast to negligible direct dispersive interactions. The resulting net repulsive interactions rationalize the experimentally observed tendency for single molecule adsorption

Interpretation of x-ray absorption spectroscopy in the presence of surface hybridization

X-ray absorption spectroscopy (XAS) yields direct access to the electronic and geometric structure of hybrid inorganic-organic interfaces formed upon adsorption of complex molecules at metal surfaces. The unambiguous interpretation of corresponding spectra is challenged by the intrinsic geometric flexibility of the adsorbates and the chemical interactions with the interface. Density-functional theory (DFT) calculations of the extended adsorbate-substrate system are an established tool to guide peak assignment in X-ray photoelectron spectroscopy of complex interfaces. We extend this to the simulation and interpretation of XAS data in the context of functional organic molecules on metal surfaces using dispersion-corrected DFT calculations within the transition potential approach. For the prototypical case of 2H-porphine adsorbed on Ag(111) and Cu(111) substrates, we follow the two main effects of the molecule/surface interaction onto the X-ray absorption signatures: (1) the substrate-induced chemical shift of the 1s core levels that dominates in physisorbed systems and (2) the hybridization-induced broadening and loss of distinct resonances that dominate in more chemisorbed systems