Hamilton's law or Hamilton's principle: A response to Ulvi Yurtsever

The law of varying action and Hamilton's principle of classical mechanics are discussed. It is now clear that the law of varying action, introduced by Hamilton in his papers of 1834 and 1935, was never recognized by either the mathematicians or other scientists who followed him. Why this occurred is discussed in this paper.     

Understanding Complex Electrochemical Impedance Spectroscopy in Corrosion Systems Using in‐situ Synchrotron Radiation Grazing Incidence X‐ray Diffraction

The difficulty in interpreting electrochemical impedance spectroscopy (EIS) data has limited the potential of the method despite its utility as an electrochemical method for studies of electrode reactions and interfacial structures. Taking the test case of the carbon dioxide corrosion of carbon steel, in‐situ synchrotron radiation grazing incidence X‐ray diffraction (SR‐GIXRD) has been demonstrated to be a powerful technique for validating and understanding the interfacial structures associated with complex EIS data. Carbon dioxide corrosion was found to occur in several steps, which may only be surmised by EIS, but the use of SR‐GIXRD in conjunction with EIS has enabled the establishment of a link between EIS time constants and structural changes associated with the evolution of corrosion products with time. By comparison to previous studies by the authors and others in this field, this communication provides the first direct experimental evidence linking SR‐GIXRD surface compositional data to otherwise indistinctive EIS time constants.     

Design,synthesis and structural diversity in coordination polymers

The fundamental precept of crystal engineering is that all the information necessary for the design of a network is already stored in the molecular building blocks used. Coordination polymers represent an example of how crystal engineering has become a paradigm for the synthesis of new architectures and compositions. We report herein ten structures that are supramolecular isomers of one another. The structures are prepared from the same building blocks under mild reaction conditions. The modularity of coordination polymers imparts structural diversity that otherwise would not be possible.     

InclusiveK *0(890) and\bar K*^0 (890) production on beryllium byK − and π− at 175 GeV

The reactions \(K^ - Be \to {}^(\bar K^) *^0 (890)X,\pi ^ - Be \to {}^(\bar K^) *^0 (890)X\) , have been studied in a 175 GeV unseparated hadron beam in the kinematic range 0<x _F <1.0 andp _T ² <5 GeV². Integrated cross-sections and the dependence of the cross-sections on the longitudinal and transverse momentum are presented, together with quark counting rules predictions. The nuclear dependence ofK ^? fragmentation intoK ^*0(890) with respect to Feynmanx is investigated from hydrogen to beryllium.     

Analytical methodology to determine stable isotopically labelled and unlabelled theophylline in human plasma using capillary gas chromatography-mass spectrometry

A method is described for the simultaneous determination of [1,3-15N] theophylline and unlabelled theophylline in human plasma using gas chromatography-mass spectrometry. Plasma samples were subjected to extractive alkylation and the stable isotopically labelled and unlabelled forms of the drug were analysed as their N-pentafluorobenzyl derivatives on an SE-52 fused-silica capillary column. Quantitation was made by selected-ion monitoring employing as the internal standard 3-isobutyl-1-methylxanthine. The method has been used to study the absorption kinetics and bioavailability of a sustained release formulation of the drug when co-administered to human volunteers with a conventional formulation of the drug labelled with the stable isotope.     

Model independent constraints on leptoquarks from rare processes

We present model independent constraints on the masses and couplings to fermions ofB andL conserving leptoquarks. Such vector or scalar particles could have masses below 100 GeV and be produced at HERA; we list the generation dependent bounds that can be calculated from rare lepton and meson decays, meson-anti-meson mixing and various electroweak tests.     

Acoustic waves in a liquid with a bubble screen

In this work, certain peculiarities of the dynamics of pressure waves in a liquid containing bubbles are studied. The specification of a model of bubbly liquids with regard to acoustic damping of the bubbles is considered. Our theoretical results are compared with experimental ones.Received: 30 June 2002, Accepted: 2 February 2003, Published online: 11 June 2003