8,384 research outputs found
The Cobalt(II) Oxidotellurate(IV) Hydroxides Co₂(TeO₃)(OH)₂ and Co₁₅(TeO₃)₁₄(OH)₂
No full textPreviously unknown Co₂(TeO₃)(OH)₂ and Co₁₅(TeO₃)₁₄(OH)₂ were obtained under mild hydrothermal reaction conditions (210 °C, autogenous pressure) from alkaline solutions. Their crystal structures were determined from single-crystal X-ray diffraction data. Co₂(TeO₃)(OH)₂ (Z = 2, P (Formula presented.), a = 5.8898(5), b = 5.9508(5), c = 6.8168(5) Å, α = 101.539(2), β = 100.036(2), γ = 104.347(2)°, 2120 independent reflections, 79 parameters, R[F² > 2σ(F²)] = 0.017) crystallizes in a unique structure comprised of undulating ²∝[Co₂(OH)₆/₃O₃/₃O₂/₂O₁/₁]⁴⁻ layers. Adjacent layers are linked by TeIV atoms along the [001] stacking direction. Co₂(TeO₃)(OH)₂ is stable up to 450 °C and decomposes under the release of water into Co₆Te₅O₁₆ and CoO. Magnetic measurements of Co₂(TeO₃)(OH)₂ showed antiferromagnetic ordering at ≈ 70 K. The crystal structure of Co₁₅(TeO₃)₁₄(OH)₂ (Z = 3, R (Formula presented.), a = 11.6453(2), c = 27.3540(5) Å, 3476 independent reflections, 112 parameters, R[F² > 2σ(F²)] = 0.026) is isotypic with Co₁₅(TeO₃)₁₄F₂. A quantitative structural comparison revealed that the main structural difference between the two phases is connected with the replacement of F by OH, whereas the remaining part of the three-periodic network defined by [CoO₆], [CoO₅(OH)], [CoO₅] and [TeO₃] polyhedra is nearly unaffected. Consequently, the magnetic properties of the two phases are similar, namely being antiferromagnetic at low temperatures
Prevalence of HCV infection in health care workers of a UK dental hospital
No full textTo determine the prevalence of hepatitis C virus (HCV) antibodies in a group of dental health care workers (DHCW)
Nonlinear formulations and improved randomized approximation algorithms for multiway and multicut problems
No full textCover title.Includes bibliographical references (p. 21-22).D. Bertsimas, C. Teo and R. Vohra
Myocardial ischemia, pancreatitis and ERCP
No full textIan C. Roberts-Thomson, Edward Teo and Kurt C. Roberts-Thomso
Response of a TeO(2) bolometer to alpha particles
No full textTeO(2) crystals are used as bolometers in experiments searching for Double Beta Decay without emission of neutrinos. One of the most important issues in this extremely delicate kind of experiments is the characterization of the background. The knowledge of the response to a particles in the energy range where the signal is expected is therefore a must. In this paper we report the results on the response function of a TeO(2) bolometer to alpha's emitted by (147)Sm dissolved in the crystal at the growth phase. A Quenching Factor of (1.0076 +/- 0.0005) is found, independent of the temperature in the investigated range. The energy resolution on a peaks shows a standard calorimeter energy dependence: sigma[keV] = (0.56 +/- 0.02) circle plus (0.010 +/- 0.002) root E[keV]. Signal pulse shape shows no difference between alpha and beta/gamma particles
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