19,711 research outputs found

    Free radical formation during machining and fracture of polymers

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    Electron paramagnetic resonance measurements of free radical formation during cutting and grinding of polymer

    The phenomenology of electric dipole moments in models of scalar leptoquarks

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    We study the phenomenology of electric dipole moments (EDMs) induced in various scalar leptoquark models. We consider generic leptoquark couplings to quarks and leptons and match to Standard Model effective field theory. After evolving the resulting operators to low energies, we connect to EDM experiments by using up-to-date hadronic, nuclear, and atomic matrix elements. We show that current experimental limits set strong constraints on the possible CP-violating phases in leptoquark models. Depending on the quarks and leptons involved in the interaction, the existing searches for EDMs of leptons, nucleons, atoms, and molecules all play a role in constraining the CP-violating couplings. We discuss the impact of hadronic and nuclear uncertainties as well as the sensitivities that can be achieved with future EDM experiments. Finally, we study the impact of EDM constraints on a specific leptoquark model that can explain the recent BB-physics anomalies.Comment: Published versio

    Influence of particle size and structure of ZrO2 on microstructure development and dielectric constant of PbZr0.5Ti0.5O3

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    The synthesis of PbZr0.5Ti0.5O3 ceramics from the raw materials was reinvestigated in order to find relations in the characterizations for the products in various stages of the preparation procedure. Techniques used were particle size measurements, X-ray powder diffractometry, density and dielectric constant measurements and scanning electron microscopy. The results show, that the particle size and structure of ZrO2 determine the inhomogeneity, expressed as xt/xr, of the calcination product. An inhomogeneous calcination product sintered at relatively low temperatures results in an inhomogeneous ceramic of low density. Using high sintering temperatures and long periods of time an inhomogeneous calcination product converts into a dense (>97%) and homogeneous ceramic

    Paramagnetic resonance effect in viscoelastic materials Annual progress report, 1 Jan. - 31 Dec. 1968

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    Electron paramagnetic resonance investigation of fracture in viscoelastic material

    Influence of electrode geometry and NLLS fit analysis of I-V measurements in a three-electrode cell

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    The analysis of electrode polarisation (I-V) measurements of oxygen electrodes on δ-Bi2O3-based solid electrolytes is complicated by an ohmic polarisation correction which is of the order of the electrode resistance. The analysis can be performed with a NLLS fit technique, which includes this correction resistance, Ru, as adjustable parameter. By an appropriate choice of the electrode geometry the factor Ru can be minimized

    The electrochemical influence and oxygen exchange properties of mixed conducting electrode materials on solid oxide electrolytes

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    Electrolyte electrode materials combinations of Er2O3 stabilized Bi2O3 and mixed i.e. both electronic and ionic conducting materials are investigated in order to lower electrode polarization losses and operating temperatures of electrochemical sensors, pumps and SOFC reactors made of them. 18O exchange rates are correlated with exchange current densities

    Continuous Intracranial Pressure Monitoring in Patients with Brain Injury: Technique and Application

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    Continuous ICP monitoring using the hollow screw technique has proven itself simple, safe, and reliable. The obvious advantage of continuous ICP monitoring is to provide early warning of developing mass lesions before clinical signs appear and to assess the effectiveness of therapy directed at brain edema. Its most important use, however, may be that it permits the use of depressant medications in these patients. Many of these patients have a marked tendency toward hyperthermia, severe hyperventilation, and erratic blood pressure swings. These tendencies can be most difficult to control with conventional treatment regimens. By sedating these patients, however, it is easy to override these tendencies with a respirator, a simple heat exchange mattress, and patient positioning. In many of these patients, all of the intracranial compensatory mechanisms for the maintenance of brain metabolism have been maximally taxed

    Simlandscape: serious gaming in participatory spatial

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    In an attempt to improve support for contemporary spatial planning practice, Simlandscape has been developed. In this document the development of Simlandscape as ¿serious game¿ in digital form is described. In its current state, Simlandscape exists in two methodological forms; as an analogue game and as a planning support system using GIS for research and design. The game focuses on simulation of plan processes and on the resulting transformation of areas involved. Players interact with an analogue area model. The planning support system focuses on design and evaluation of plan scenarios and the data handling and presentation accompanying this process. A major challenge now is to integrate, upgrade and digitize components of the analogous game with the planning support system. Several interesting components (practical and scientific) of this project are identified and are discussed

    Misreporting of energy and micronutrient intake estimated by food records and 24 hour recalls, control and adjustment methods in practice

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    In order to assess nutritional adequacy, valid estimates of nutrient intake are required. One of the main errors in dietary assessment is misreporting. The objective was to review the extent, nature and determinants of misreporting in dietary assessment, how this affects reported intakes of micronutrients and how this is identified and measured, and to identify the best ways of dealing with misreporting when interpreting results. A systematic literature search was conducted for studies of misreporting of dietary intake in adults by 24 hour recalls or by estimated or weighed food records, published up to March 2008. Thirty-seven relevant studies were identified. Possible causes of misreporting were identified. Methods most used to identify misreporting were the Goldberg cut-off (46 % studies) and the doubly labelled water technique (24 % studies). The magnitude of misreporting of energy intake was similar in all three dietary assessment methods. The percentage of under-reporters was about 30 % and energy intake was underestimated by approximately 15 %. Seven papers presented usable data for micronutrient intake. Absolute intakes of Fe, Ca and vitamin C (the three micronutrients addressed in all papers) were on average 30 % lower in low-energy reporters (LER) than that in non-LER and, although results were not consistent, there was a tendency for micronutrient density to be higher in LER. Excluding underreporters or using energy adjustment methods for micronutrient intakes is discussed. Residual method of energy adjustment seems to be a good tool for practice to decrease an influence of misreporting when interpreting results of studies based on food records and 24 hour recall

    Bismuth oxide based ceramics with improved electrical and mechanical properties: Part II. Structural and mechanical properties

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    Coprecipitation as a method of preparation for bismuth oxides based ceramics yields relatively strong and machineable materials in comparison with the solid state reaction. Compositions within the system (1−x)Bi2O3|xEr2O3 containing up to twenty five mole percent of erbium oxide show a slow transition on heating at 900 K from a cubic to a hexagonal (rhombohedral) phase. The resulting hexagonal phase is stable up to 1000 K where it transforms back to the cubic phase. Long term heating at 775 K causes formation of traces of ∝ - bismuth oxide in these samples, but the material itself remains cubic. Compositions containing thirty mole percent of erbium oxide do not show any such changes and hence are suitable for application purposes
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