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Friction Generated Limit Cycles

This paper treats limit cycles caused by friction. The goal has been to explain phenomena that have been observed experimentally in mechatronic systems. Experiments have shown that oscillations of qualitatively different types can be obtained simply by changing controller specifications. Stiction is important in some cases but not in others. Necessary conditions for limit cycle are given for the c

Impact of electron beam quality on nonlinear harmonic generation in high-gain free-electron lasers

Nonlinear harmonic generation can be a very useful and important phenomenon for single-pass free-electron lasers (FELs) operating in the high-gain regime. Strong bunching at the fundamental wavelength and its associated higher harmonic content allow significant radiation at shorter wavelengths to be emitted without serious effects upon the output power at the fundamental. Here, we analyze the rela

Isomerisation of omega-hydroxyalkenes under hydroxycarbonylation conditions in palladium catalysed aqueous phase systems

The omega-hydroxyolefins 3-buten-1-ol, 3-buten-1-methyl-1-ol and 4-penten-1-ol were subjected to hydroxycarbonylation conditions in water in the presence of PdCL2(PhCN)(2) and 4-8 equiv. of water soluble tris(3-sodiumsulfonatophenyl)phosphine (TPPTS), or N-bis(N',N'-diethyl-2-aminoethyl)-4-aminomethylphenyl-diphenylphosphine (N3P). Under conditions of high conversion, the olefins primarily undergo

Excited States of the Proton Emitter 105Sb

Excited states in the proton emitter Sb-105 have been investigated for the first time. The nucleus was populated in the reaction Cr-50(Ni-58,1p2n). The GAMMASPHERE Ge-detector array was used together with Microball and the Neutron Shell for selection of the reaction channel. The experimental level scheme agrees well with results of a shell model calculation that uses realistic effective interactio

Free nanoscale sodium clusters studied by core-level photoelectron spectroscopy

Free sodium metal clusters have been studied by probing the Na 2p core level using x-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). The development of electronic structure with size has been studied and discussed in comparison with the atom, dimer, and solid. Information on cluster metallic properties, size, and temperature has been deduced from the XPS measurements. F

Antibody to a hepatitis C virus related protein among patients at high risk for hepatitis B

Anti-HCV prevalence in treated hemophiliacs, their heterosexual partners, intravenous drug addicts and homosexual men was studied. In hemophiliacs and many of the intravenous drug addicts, greater than or equal to 2 sera drawn 1-18 or 1-17 years apart were available. Anti-HCV testing was performed by ELISA (Ortho). Among patients with severe and moderate hemophilia A, 87% (98/112) were positive fo

Stock Rationing in a Continuous Review Two-Echelon Inventory Model

In this paper we consider a 1-warehouse, N-retailer inventory system where demand occurs at all locations. We introduce an inventory model which allows us to set different service levels for retailers and direct customer demand at the warehouse. For each retailer a critical level is defined, such that a retailer replenishment order is delivered from warehouse stock if and only if the stock level e

Peptide fusion tags with tryptophan and charged residues for control of protein partitioning in PEG-potassium phosphate aqueous two-phase systems

A partition study with peptides and recombinant proteins in poly(ethylene glycol)4000-potassium phosphate aqueous two-phase systems has been performed. The aim was to study to what extent the insertion of charged residues could affect protein partition in addition to the already observed effects of tryptophan residues. The model proteins used are based on a staphylococcal protein A derivative, Z,

An open and shut case

A powerful new NMR technique applied to the ubiquitous Ca2+ sensor, calmodulin, reveals significant conformational flexibility within each globular domain, which contributes to its ability to bind a wide range of targets. These measurements of residual dipolar couplings between nuclear spins demonstrate a fast and accurate method for pinpointing structural features that cannot be delineated reliab

Why is congenital dislocation of the hip still missed? Analysis of 96,891 infants screened in Malmo 1956-1987

During 1956 through 1987, 96,891 children have been screened for neonatal hip instability according to the tests of Ortolani and Barlow. In 1956 through 1972 only 4/58, 759 (0.07 permille) were missed, whereas during 1980 through 1987, 12/19, 398 (0.6 permille) were missed. This increase is not caused by any formal alteration of the screening programme. The screening has prevented a late diagnosis

En pilotstudie om arbete i kyla - frågeundersökning och fältstudie

En pilotstudie som innefattade en frågeundersökning på några arbetsplatser och en fältstudie på en av dessa arbetsplatser genomförde's under vintern 1997/98. Studien hade som syfte att sammanlänka laboratorieresultat med resultat under verkliga arbetsförhållanden och att kartlägga problem för individer vid utomhusarbete vintertid. Frågeformulären besvarade's av 43 hamnarbetare, mast- och teletekniDésirée Gavhed, Kalev Kuklane, Eva Karlsson, Ingvar Holmér. A pilot study on work in the cold - questionnaire survey and field study. Arbetslivsrapport 1999:4. A pilot study regarding work in cold conditions was performed during the winter period 1997-1998. The study comprised two parts, a questionnaire survey and a set of field measurements. The purpose of the study was to link laboratory studies

Resource allocation with wobbly functions

We consider resource allocation with separable objective functions defined over subranges of the integers. While it is well known that (the maximisation version of) this problem can be solved efficiently if the objective functions are concave, the general problem of resource allocation with functions that are not necessarily concave is difficult. In this article, we focus on a large class of probl

Tourism, Ecosystem Functions, and Human-Environmental Relations

The thesis aims at deconstructing the sustainable tourism paradigm: can tourism be "a global strategy for sustainable development", as the tourist industry claims? And will developing countries in particular profit from tourism development?To most international organizations and institutions (from the World Wide Fund for Nature to The World Bank), tourism, if carefully managed, is a positive, sust

Identification of Excited States in 61Ga: Mirror Nuclei in the Upper fp Shell

In the fusion-evaporation reaction Ca-40+Mg-24 at 104 MeV beam energy, excited states have been observed for the first time in the isotope Ga-31(61)30. The experimental setup comprised the Ge array CLARION, a recoil mass spectrometer and, in its focal plane, an ionization chamber. Five transitions in Ga-61 are identified, out of which a cascade of three transitions has been established by means of