Bestimmung der Harns?ure und der Xanthinbasen im Harn

Ohne Zusammenfassung     

Constructions for rotational near resolvable block designs

A (ν, k, k?1) near resolvable block design (NRBD) is r‐rotational over a group G if it admits G as an automorphism group of order (ν?1)/r fixing exactly one point and acting semiregularly on the others. We give direct and recursive constructions for rotational NRBDs with particular attention to 1‐rotational ones. © 2001 John Wiley & Sons, Inc. J Combin Designs 9: 157–181, 2001     

Transonic Hodograph Design Problems

The hodograph method is used to formulate several design problems in transonic flow using small-disturbance theory. Analytical and numerical methods give solutions to several optimum critical airfoil designs with different constraints on the tail angle. Special airfoil shapes flying at free-stream Mach number one are designed. The problem of constructing a shock-free body of revolution at subsonic speed but having a supersonic zone is formulated in the hodograph and solved numerically. Received 10 January 1997 and accepted 14 April 1997     

The theory of sharp first-order univalence criteria

A condition of the formf′ (D) ⊂R is calleda first-order univalence criterion if all functions for which it holds are univalent inD. By means of a careful analysis of the behavior of the corresponding extremal functions, we establish fundamental principles for a coherent theory of sharp criteria of this kind. In particular, we examine the relationship between three different concepts of sharpness and show how large classes of first-order univalence criteria which are sharp in a strong sense may be described in terms of the univalence properties of families of analytic functions depending on a finite number of parameters. This research was supported in part by the Chilean government through FONDECYT grant No. 0809-91.     

An inequality for Steklov eigenvalues for planar domains

Study of the zeta function associated to the Neumann operator on planar domains yields an inequality for Steklov eigenvalues for planar domains.This research was partially supported by the Natural Sciences and Engineering Research Council of Canada.     

Graph-distance convergence and uniform local boundedness of monotone mappings

In this article we study graph-distance convergence of monotone operators. First, we prove a property that has been an open problem up to now: the limit of a sequence of graph-distance convergent maximal monotone operators in a Hilbert space is a maximal monotone operator. Next, we show that a sequence of maximal monotone operators converging in the same sense in a reflexive Banach space is uniformly locally bounded around any point from the interior of the domain of the limit mapping. The result is an extension of a similar one from finite dimensions. As an application we give a simplified condition for the stability (under graph-distance convergence) of the sum of maximal monotone mappings in Hilbert spaces.

     

Many-body potential for point defect clusters in Fe-C alloys

Modeling the consequences of crystalline defects requires efficient interaction sampling. Empirical potentials can identify relevant pathways if the energetics and configurations of competing defects are captured. Here, we develop such a potential for an alloy of arbitrary point defect concentration, body-centered cubic alpha-Fe supersaturated in C. This potential successfully calculates energetically favored defects, and predicts formation energies and configurations of multicarbon-multivacancy clusters that were not attainable with existing potentials or identified previously via ab initio methods.     

Metal‐Doped Nitrogenated Carbon as an Efficient Catalyst for Direct CO2 Electroreduction to CO and Hydrocarbons

This study explores the kinetics, mechanism, and active sites of the CO₂ electroreduction reaction (CO2RR) to syngas and hydrocarbons on a class of functionalized solid carbon‐based catalysts. Commercial carbon blacks were functionalized with nitrogen and Fe and/or Mn ions using pyrolysis and acid leaching. The resulting solid powder catalysts were found to be active and highly CO selective electrocatalysts in the electroreduction of CO₂ to CO/H₂ mixtures outperforming a low‐area polycrystalline gold benchmark. Unspecific with respect to the nature of the metal, CO production is believed to occur on nitrogen functionalities in competition with hydrogen evolution. Evidence is provided that sufficiently strong interaction between CO and the metal enables the protonation of CO and the formation of hydrocarbons. Our results highlight a promising new class of low‐cost, abundant electrocatalysts for synthetic fuel production from CO₂.