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Unlike metals where dislocations carry strain singularity but no charge, dislocations in oxide ceramics are characterized by both a strain field and a local charge with a compensating charge envelope. Oxide ceramics with their deliberate engineering and manipulation are pivotal in numerous modern technologies such as semiconductors, superconductors, solar cells, and ferroics. Dislocations facilitate plastic deformation in metals and lead to a monotonous increase in the strength of metallic materials in accordance with the widely recognized Taylor hardening law. However, achieving the objective of tailoring the functionality of oxide ceramics by dislocation density still remains elusive. Here a strategy to imprint dislocations with {100}<100> slip systems and a tenfold change in dislocation density of BaTiO3 single crystals using high‐temperature uniaxial compression are reported. Through a dislocation density‐based approach, dielectric permittivity, converse piezoelectric coefficient, and alternating current conductivity are tailored, exhibiting a peak at medium dislocation density. Combined with phase‐field simulations and domain wall potential energy analyses, the dislocation‐density‐based design in bulk ferroelectrics is mechanistically rationalized. These findings may provide a new dimension for employing plastic strain engineering to tune the electrical properties of ferroics, potentially paving the way for advancing dislocation technology in functional ceramics. [ABSTRACT FROM AUTHOR]

Aim: Examine perceptions of nurses who obtained a recognised nursing qualification in Germany about the integration of internationally qualified nurses (IQN) in the German nursing workforce. Design: Qualitative interview study. Methods: Semi‐structured interviews with 21 state‐qualified nurses who had graduated from a German nursing program were conducted either face‐to‐face or by telephone. Nurses were selected using the purposive sampling method. Additionally, to reach a sufficient sample size, snowball sampling was applied. Each interview was pseudonymized and transcribed. Transcripts were coded according to Qualitative Content Analysis with data structured into themes and sub‐themes. The study was reported according to the Consolidated Criteria for Reporting Qualitative Studies (COREQ) checklist for qualitative research. Results: Two main themes including sub‐themes were identified: (a) Enabling Factors to Workplace Integration: motivated nursing team, structured orientation program, support by a preceptor, additional practical skills and specific language training and (b) Barriers to Workplace Integration: lack of language proficiency, cultural differences, othering and racism/discrimination. The findings of the study suggest that working in a diverse workplace can be challenging, it is therefore important for successful integration to recognise not only the experiences of IQN but also the perceptions of nurses who work with internationally qualified peers. No patient or public contribution. Registration number: The study has been prospectively registered (27 June 2019) at the German Clinical Trial Register (REDACTED). [ABSTRACT FROM AUTHOR]

Piezoceramics are widely‐used in high‐power applications, whereby the material is driven in the vicinity of the resonance frequency with high electric fields. Evaluating material's performance at these conditions requires the consideration of inherent nonlinearity, anisotropy, and differences between individual vibration modes. In this work, the relation between electromechanical properties at large vibration velocity and the utilized vibration mode is investigated for a prototype hard piezoceramic. The nonlinear behavior is determined using a combined three‐stage pulse drive method, which enables the analysis of resonant and antiresonant conditions and the calculation of electromechanical parameters. The deviations of coupling coefficients, compliances, and piezoelectric coefficients at high‐power drive were found to be strongest for the transverse length vibration mode. Differences in the mechanical quality factors were observed only between the planar and transverse length modes, which were rationalized by the different strain distribution profiles and the contribution of different loss tensor components. In addition, the influence of the measurement configuration was investigated and a correction method is proposed. The differences between vibration modes are further confirmed by heat generation measurements under continuous drive, which revealed that the strongest heat generation appears in the radial mode, while transverse and longitudinal length modes show similar temperature increase. Piezoceramics are widely‐used in high‐power applications, whereby the material is driven in the vicinity of the resonance frequency with high electric fields. Evaluating material's performance at these conditions requires the consideration of inherent nonlinearity, anisotropy, and differences between individual vibration modes. In this work, the relation between electromechanical properties at large vibration velocity and the utilized vibration mode is investigated for a prototype hard piezoceramic. The nonlinear behavior is determined using a combined three‐stage pulse drive method, which enables the analysis of resonant and antiresonant conditions and the calculation of electromechanical parameters. The deviations of coupling coefficients, compliances, and piezoelectric coefficients at high‐power drive were found to be strongest for the transverse length vibration mode. Differences in the mechanical quality factors were observed only between the planar and transverse length modes, which were rationalized by the different strain distribution profiles and the contribution of different loss tensor components. In addition, the influence of the measurement configuration was investigated and a correction method is proposed. The differences between vibration modes are further confirmed by heat generation measurements under continuous drive, which revealed that the strongest heat generation appears in the radial mode, while transverse and longitudinal length modes show similar temperature increase. [ABSTRACT FROM AUTHOR]

Compositional engineering with a focus on structural phase transitions has been considered as the most important approach for enhancement of the functional properties of ferroelectric materials due to the critical fluctuation of physical properties. Of special interest are electric-field-induced phase transitions, which can terminate in a liquid-vapor-type critical point with a strong enhancement of functional properties. Whereas the critical point in liquid-vapor space considers changes in temperature and pressure, the critical point in this study is placed in electric field-temperature diagrams. In single crystals, temperature and electric field of a critical point are sharply defined and therefore not appealing for practical applications. However, in ceramics, it is demonstrated that the orientational dependence of the critical point leads to a broadened temperature and electric field range. The presence of a diffuse critical point in ceramics provides a conceptually novel approach for the enhancement of functional properties, such as piezoelectric and electrocaloric (EC) responses, as validated here on the example of the 0.75Bi1/2Na1/2TiO3-0.25SrTiO3 lead-free relaxor ferroelectric ceramics. The realization of a broad criticality range will further facilitate the development of the piezoelectric and EC materials and provide an alternative concept to manipulate the functional properties by application of an electric field. [ABSTRACT FROM AUTHOR]

Myocardial accumulation of GBR 12909 showed monophasic exponential kinetics with a half-life of 93 min. The disposition followed a three-phasic exponential time-course with half-lives of 1.1, 17 and 98 min., respectively, which was interpreted as three-compartment kinetics. The drug accumulated 430 times in the myocardium at steady-state with 8, 30 and 61% of the drug amount referable to a central, superficial and two deeper myocardial drug pools. GBR 12909 produced concentration dependent (range 0.01 to 12400 nM) biphasic negative inotropic and chronotropic effects. The inhibitory Em-values with regard to contraction velocity were 42 and 105% with corresponding EC50-values of 29 and 688 nM and the related Hill-exponents were 0.6 and 1.1, respectively. Frequency and contraction amplitude related inhibitory Em-values were of similar size. Apparent dynamic steady states developed within about 17 min. Very marked monophasic negative dromotropic effects were observed with computer-derived inhibitory Em-values related to the electrocardiographic PQ- and QRS-intervals exceeding 100%. The frequency-corrected QTc-interval showed an initial increase of 10% but decreased to about 20% below control level at the highest two drug concentrations. Coronary flow-rate increased about 30% and then gradually decreased to near the control value. Oxygen consumption only decreased at the three highest concentrations. Our findings seem compatible with the view that GBR 12909 may possibly act in the myocardium as a membrane-stabilizer which causes inhibition of Na+- and Ca++-influx over sarcolemma. Intracellular inhibition of Ca++-liberation from organelles and other calcium depots also seems possible. [ABSTRACT FROM AUTHOR]

Unlike metals where dislocations carry strain singularity but no charge, dislocations in oxide ceramics are characterized by both a strain field and a local charge with a compensating charge envelope. Oxide ceramics with their deliberate engineering and manipulation are pivotal in numerous modern technologies such as semiconductors, superconductors, solar cells, and ferroics. Dislocations facilitate plastic deformation in metals and lead to a monotonous increase in the strength of metallic materials in accordance with the widely recognized Taylor hardening law. However, achieving the objective of tailoring the functionality of oxide ceramics by dislocation density still remains elusive. Here a strategy to imprint dislocations with {100}<100> slip systems and a tenfold change in dislocation density of BaTiO3 single crystals using high‐temperature uniaxial compression are reported. Through a dislocation density‐based approach, dielectric permittivity, converse piezoelectric coefficient, and alternating current conductivity are tailored, exhibiting a peak at medium dislocation density. Combined with phase‐field simulations and domain wall potential energy analyses, the dislocation‐density‐based design in bulk ferroelectrics is mechanistically rationalized. These findings may provide a new dimension for employing plastic strain engineering to tune the electrical properties of ferroics, potentially paving the way for advancing dislocation technology in functional ceramics. [ABSTRACT FROM AUTHOR]

Piezoceramics are widely‐used in high‐power applications, whereby the material is driven in the vicinity of the resonance frequency with high electric fields. Evaluating material's performance at these conditions requires the consideration of inherent nonlinearity, anisotropy, and differences between individual vibration modes. In this work, the relation between electromechanical properties at large vibration velocity and the utilized vibration mode is investigated for a prototype hard piezoceramic. The nonlinear behavior is determined using a combined three‐stage pulse drive method, which enables the analysis of resonant and antiresonant conditions and the calculation of electromechanical parameters. The deviations of coupling coefficients, compliances, and piezoelectric coefficients at high‐power drive were found to be strongest for the transverse length vibration mode. Differences in the mechanical quality factors were observed only between the planar and transverse length modes, which were rationalized by the different strain distribution profiles and the contribution of different loss tensor components. In addition, the influence of the measurement configuration was investigated and a correction method is proposed. The differences between vibration modes are further confirmed by heat generation measurements under continuous drive, which revealed that the strongest heat generation appears in the radial mode, while transverse and longitudinal length modes show similar temperature increase. Piezoceramics are widely‐used in high‐power applications, whereby the material is driven in the vicinity of the resonance frequency with high electric fields. Evaluating material's performance at these conditions requires the consideration of inherent nonlinearity, anisotropy, and differences between individual vibration modes. In this work, the relation between electromechanical properties at large vibration velocity and the utilized vibration mode is investigated for a prototype hard piezoceramic. The nonlinear behavior is determined using a combined three‐stage pulse drive method, which enables the analysis of resonant and antiresonant conditions and the calculation of electromechanical parameters. The deviations of coupling coefficients, compliances, and piezoelectric coefficients at high‐power drive were found to be strongest for the transverse length vibration mode. Differences in the mechanical quality factors were observed only between the planar and transverse length modes, which were rationalized by the different strain distribution profiles and the contribution of different loss tensor components. In addition, the influence of the measurement configuration was investigated and a correction method is proposed. The differences between vibration modes are further confirmed by heat generation measurements under continuous drive, which revealed that the strongest heat generation appears in the radial mode, while transverse and longitudinal length modes show similar temperature increase. [ABSTRACT FROM AUTHOR]