2,047 research outputs found
Anemia and the Role of the Pharmacist
This home-study CPE has been developed to educate pharmacists and pharmacy technicians about the various types of anemia and their treatments
Human urine certified reference material CZ 6010: creatinine and toluene metabolites (hippuric acid and o-cresol) and a benzene metabolite (phenol)
A reference material for the biological monitoring of occupational exposure to toluene, benzene and phenol was prepared. O-cresol and hippuric acid (metabolites of toluene) are used for the biological monitoring of occupational exposure to toluene. Phenol, a metabolite of benzene, is used for the biological monitoring of exposure to benzene, but phenol can of course also be used as an indicator of exposure to phenol as well. The reference material (RM) used for the determination of these metabolites was prepared by freeze-drying pooled urine samples obtained from healthy persons occupationally exposed to toluene and those taking part in an inhalation experiment. Tests for homogeneity and stability were performed by determining urine concentrations of o-cresol, hippuric acid, creatinine and phenol. To investigate the stability of the RM, the urinary concentrations of o-cresol and phenol were monitored for eighteen months using GC and HPLC, while those of hippuric acid and creatinine were followed for five and six years, respectively, using HPLC. Analysis of variance showed that the concentrations did not change. The certified concentration values (and their uncertainties) of the substances in this reference material (phenol concentration c=6.46+/-0.58 mg l(-1); o-cresol concentration c=1.17+/-0.15 mg l(-1); hippuric acid concentration c=1328+/-30 mg l(-1); creatinine concentration c=0.82+/-0.10 g l(-1)) were evaluated via the interactive statistical programme IPECA
Deviations from plastic barriers in BiSrCaCuO thin films
Resistive transitions of an epitaxial BiSrCaCuO thin
film were measured in various magnetic fields (), ranging from 0
to 22.0 T. Rounded curvatures of low resistivity tails are observed in
Arrhenius plot and considered to relate to deviations from plastic barriers. In
order to characterize these deviations, an empirical barrier form is developed,
which is found to be in good agreement with experimental data and coincide with
the plastic barrier form in a limited magnetic field range. Using the plastic
barrier predictions and the empirical barrier form, we successfully explain the
observed deviations.Comment: 5 pages, 6 figures; PRB 71, 052502 (2005
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Generalised resultants, dynamic polynomial combinants and the minimal design problem
The theory of dynamic polynomial combinants is linked to the linear part of the dynamic determinantal assignment problems (DAP), which provides the unifying description of the dynamic, as well as static pole and zero dynamic assignment problems in linear systems. The assignability of spectrum of polynomial combinants provides necessary conditions for solution of the original DAP. This paper demonstrates the origin of dynamic polynomial combinants from linear systems, examines issues of their representation and the parameterisation of dynamic polynomial combinants according to the notions of order and degree, and examines their spectral assignment. Central to this study is the link of dynamic combinants to the theory of generalised resultants, which provide the matrix representation of the dynamic combinants. The paper considers the case of coprime set of polynomials for which spectral assignability is always feasible and provides a complete characterisation of all assignable combinants with order above and below the Sylvester order. A complete parameterisation of combinants and respective generalised resultants is given and this leads naturally to the characterisation of the minimal degree and order combinant for which spectrum assignability may be achieved, which is referred to as the dynamic combinant minimal design (DCMD) problem. An algorithmic approach based on rank tests of Sylvester matrices is given, which produces the minimal order and degree solution in a finite number of steps. Such solutions provide low bounds for the respective dynamic assignment control problems
Design and development of a coaxial cryogenic probe for precision measurements of the quantum hall effect in the ac regime
The quantum Hall effect is the basis for the realisation of the resistance and impedance units in the International System of units since 2019. This paper describes a cryogenic probe that allows to set graphene Hall devices in quantisation conditions in a helium bath (4.2 K) and magnetic fields up to 6 T, to perform precision measurements in the AC regime with impedance bridges. The probe has a full coaxial wiring, isolated from the probe structure, and holds the device in a TO-8 socket. First, characterization experiments are reported on a GaAs device, showing quantisation at 5.5 T. In the AC regime, multiple-series connections will be employed to minimize the residual error, quantified by electrical modelling of the probe
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