Dielectric relaxation and charged domain walls in (K,Na)NbO3-based ferroelectric ceramics

We report on the evidence of significant contribution of charged domain walls to low frequency dielectric permittivity in KNN ferroelectric ceramics in the frequency range 10-106 Hz. The effect has been attributed to the Maxwell-Wagner-Sillars relaxation.The equipment of the Ural Center for Shared Use "Modern nanotechnology" UrFU was used

The 2018 revision of the standard IEC 61400-24 : lightning protection of wind turbines

The first edition of the standard IEC 61400-24, Wind Generator Systems – Part 24 Lightning Protection, was issued in June 2010, and the scope was to reflect the experiences and technical understanding of lightning protection of wind turbines by manufacturers, certification organizations, research institutes and universities. It presented background statistical information on lightning damage to wind turbines, and it provided guidance on lightning protection best practices. Since then, the wind power industry has further developed towards even larger onshore and offshore wind turbines and into a mature industry. This is the background for the current draft of the 2018 revision of the IEC 61400-24, which transforms the 2010 edition into an evolution of the previous issued standard based on improved technical experience and expertise

Carcinoma de células renales: estadificación prequirúrgica por tomografía computada y su analogía con la anatomía patológica Renal cell carcinoma: preoperative staging by computed tomography and its analogy to pathology

Objetivo. Evaluar la correlación entre la estadificación preoperatoria de los carcinomas de células renales usando tomografía computada y los resultados anatomopatológicos de la pieza operatoria. Materiales y Métodos. Se llevó a cabo un estudio retrospectivo entre los años 2005 y 2011, tomando un total de 40 pacientes con diagnóstico presuntivo de carcinoma de células renales (CCR) del Servicio de Urología, que habían sido sometidos a nefrectomía total o parcial. Se compararon diferentes parámetros del estudio imagenológico (tomografía computada) y anatomopatológico de cada paciente y se evaluó qué reciprocidad existía entre la estadificación pre y posoperatoria según el TNM. Resultados. Los datos obtenidos mediante el estudio anatomopatológico de la pieza operatoria mostraron 28 lesiones limitadas al riñón (estadios T1 y T2), 3 lesiones con extensión perirrenal y a la vena renal (estadio T3a), 7 lesiones con compromiso de la vena cava (estadio T3b) y 2 lesiones con extensión más allá de la fascia de Gerota (estadio T4). Se encontró una fuerza de concordancia casi perfecta entre la estadificación tomográfica y anatomopatológica (kappa = 0,87) con respecto al criterio T del TNM. Sólo 2 T1b (por estudio anatomopatológico) fueron sobrediagnosticados como T2 (según tomografía computada) y 2 T3b (según estudio anatomopatológico) se subdiagnosticaron como T3a (según tomografía computada). Conclusión. La tomografía computada proporciona una buena delimitación y caracterización del carcinoma de células renales. El nivel de concordancia con el patrón de referencia más fiable (anatomía patológica) resultó casi perfecto (k = 0,87) para la estadificación del estadio T.Objective. To evaluate the correlation between the preoperative staging of renal cell carcinoma by computed tomography (CT) and histopathologic results of the surgical specimen. Materials and Methods. A retrospective study has been carried out in a total of 40 patients from our urology department with suspected diagnosis of renal cell carcinoma (RCC) who had undergone total or partial nephrectomy between 2005 and 2011. We compared different parameters of imaging (CT) and pathological studies of each patient and assessed the reciprocal relationship between pre-and postoperative staging according to TNM. Results. Data obtained by pathological examination of the resected specimen showed 28 lesions limited to the kidney (stages T1 and T2), 3 lesions with perirenal extension and renal vein (stage T3a), 7 lesions with involvement of the vena cava (stage T3b) and 2 lesions with extension beyond Gerota's fascia (stage T4). We found an almost perfect strength of agreement between tomographic and pathologic staging (kappa = 0.87), with respect to T of the TNM criteria. Only two T1b (by pathological study) were overdiagnosed as T2 (by computed tomography) and two T3b (by pathological study) were underdiagnosed as T3a (by CT). Conclusion. Computed tomography provides a good delineation and characterization of renal cell carcinoma. The level of agreement with the most reliable reference standard (pathological study) was almost perfect (k = 0.87) for the staging of T stage