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Size-selective procedures were developed for the preparation of fiber fractions of uniform size of chrysotile, crocidolite, amosite and glass. The raw material was first ground to a suitable fineness, then prescreened in a vibrating bed aerosol generator and finally suspended in liquids by ultrasonic agitation. Size-separation was then achieved by slow(More)
In structurally disordered solids, some atoms or small groups of atoms are able to quantum mechanically tunnel between two nearly equivalent sites. These atomic tunneling systems have been identified as the cause of various low-temperature anomalies of bulk glasses and as a source of decoherence of superconducting qubits where they are sparsely present in(More)
Parasitic two-level tunnelling systems originating from structural material defects affect the functionality of various microfabricated devices by acting as a source of noise. In particular, superconducting quantum bits may be sensitive to even single defects when these reside in the tunnel barrier of the qubit's Josephson junctions, and this can be(More)
In preparing fiber suspensions for biological applications, as well as in many analytical procedures, the fibers--e.g. asbestos and glass--often have to be mechanically diminished and ultrasonically treated. Such treatments may sometimes produce changes in the physical and chemical properties of the original fiber samples. Measurements have been made to(More)
Recent progress with microfabricated quantum devices has revealed that an ubiquitous source of noise originates in tunneling material defects that give rise to a sparse bath of parasitic two-level systems (TLSs). For superconducting qubits, TLSs residing on electrode surfaces and in tunnel junctions account for a major part of decoherence and thus pose a(More)
We report investigations of conductance fluctuations (with 1/f(alpha) power spectra) in doped silicon at low temperatures (T<20 K) as it is tuned through the metal-insulator transition (MIT) by changing the carrier concentration n. The scaled magnitude of noise, gamma(H), increases with decreasing T following an approximate power law gamma(H) approximately(More)
A sensitive and specific method is described for the determination of norgestomet in bovine plasma as low as 10 ppt with better than 83% average recovery and a relative standard deviation (RSD) of range 1-3%. Norgestomet is separated from the bulk of the endogenous substances in plasma by adsorption on a PrepSep C18 extraction column and elution with(More)
The possible physical and chemical changes that could occur in fibre samples subjected to milling and ultrasonication during their preparation for biological applications are discussed. Milling changes not only size distribution but also the shape and crystal structure of fibres; ultrasonication had no influence on crystal structure. Changes in size and(More)