1,666 research outputs found
Early methodist experience: some prototypical accounts
A great many 20th century studies of 18th century Methodism concern John Wesley himself,
and even those which promise to tell you about early Methodist beliefs and activities often
turn out to be largely based on Wesley’s alone. Few have concerned themselves with the
humble folk who followed him. Yet it is impossible properly to understand even why Wesley
himself believed and behaved in the way he did without taking account of the minds and
desires of his disciples
Pregnancy-associated breast cancer - Special features in diagnosis and treatment
For obvious psychological reasons it is difficult to associate pregnancy - a life-giving period of our existence with life-threatening malignancies. Symptoms pointing to malignancy are often ignored by both patients and physicians, and this, together with the greater difficulty of diagnostic imaging, probably results in the proven delay in the detection of breast cancers during pregnancy. The diagnosis and treatment of breast cancer are becoming more and more important, as the fulfillment of the desire to have children is increasingly postponed until a later age associated with a higher risk of carcinoma, and improved cure rates of solid tumors no longer exclude subsequent pregnancies. The following article summarizes the special features of the diagnosis and primary therapy of pregnancy-associated breast cancer with particular consideration of cytostatic therapy
Reflection on multilayer mirrors beam profile and coherence properties
The main advantage of Bragg reflection from a multilayer mirror as a monochromator for hard X rays, is the higher photon flux density because of the larger spectral bandpass compared with crystal lattice reflection. The main disadvantage lies in the strong modulations of the reflected beam profile. This is a major issue for micro imaging applications, where multilayer based monochromators are frequently employed to deliver high photon flux density. A subject of particular interest is the origin of the beam profile modifications, namely the irregular stripe patterns, induced by the reflection on a multilayer. For multilayer coatings in general it is known that the substrate and its surface quality significantly influence the performance of mirrors, as the coating reproduces to a certain degree the roughness and shape of the substrate. This proceedings article reviews recent experiments that indicate potential options for producing wave front preserving multilayer mirrors, as well as new details on the particular mirrors our group has extensively studied in the pas
Magnetic field-assisted solidification of W319 Al alloy qualified by high-speed synchrotron tomography
Magnetic fields have been widely used to control solidification processes. Here, high-speed synchrotron X-ray tomography was used to study the effect of magnetic fields on solidification. We investigated vertically upward directional solidification of an Al-Si-Cu based W319 alloy without and with a transverse magnetic field of 0.5 T while the sample was rotating. The results revealed the strong effect of a magnetic field on both the primary α-Al phase and secondary β-Al5FeSi intermetallic compounds (IMCs). Without the magnetic field, coarse primary α-Al dendrites were observed with a large macro-segregation zone. When a magnetic field is imposed, much finer dendrites with smaller primary arm spacing were obtained, while macro-segregation was almost eliminated. Segregated solutes were pushed out of the fine dendrites and piled up slightly above the solid/liquid interface, leading to a gradient distribution of the secondary β-IMCs. This work demonstrates that rotating the sample under a transversal magnetic field is a simple yet effective method to homogenise the temperature and composition distributions, which can be used to control the primary phase and the distribution of iron-rich intermetallics during solidification
Instability of liquid Cu films on a SiO2 substrate
We study the instability of nanometric Cu thin films on SiO2 substrates. The metal is melted by means of laser pulses for some tens of nanoseconds, and during the liquid lifetime, the free surface destabilizes, leading to the formation of holes at first and then in later stages of the instability to metal drops on the substrate. By analyzing the Fourier transforms of the SEM (scanning electron microscope) images obtained at different stages of the metal film evolution, we determine the emerging length scales at relevant stages of the instability development. The results are then discussed within the framework of a long-wave model. We find that the results may differ whether early or final stages of the instability are considered. On the basis of the interpretation of the experimental results, we discuss the influence of the parameters describing the interaction of the liquid metal with the solid substrate. By considering both the dependence of dominant length scales on the film thickness and the measured contact angle, we isolate a model which predicts well the trends found in the experimental data.Fil: Gonzalez, Alejandro Guillermo. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Fisica Arroyo Seco; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Tandil. Centro de Investigaciones en FÃsica e IngenierÃa del Centro de la Provincia de Buenos Aires; ArgentinaFil: Diez, Javier Alberto. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Fisica Arroyo Seco; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Tandil. Centro de Investigaciones en FÃsica e IngenierÃa del Centro de la Provincia de Buenos Aires; ArgentinaFil: Wu, Yueying. University of Tennessee. Department of Materials Sciences and Engineering; Estados UnidosFil: Fowlkes, Jason D.. Oak Ridge National Laboratory. Center for Nanophase Materials Sciences; Estados UnidosFil: Rack, Philip D.. University of Tennessee. Department of Materials Sciences and Engineering; Estados Unidos. Oak Ridge National Laboratory. Center for Nanophase Materials Sciences; Estados UnidosFil: Kondic, Lou. New Jersey Institute of Technology. Department of Mathematical Sciences; Estados Unido
Liquid-State Dewetting of Pulsed-Laser-Heated Nanoscale Metal Films and Other Geometries
Metal films of nanoscale thickness, deposited on substrates and exposed to laser heating, provide systems that involve several interesting multiphysics effects. In addition to fluid mechanical aspects associated with a free boundary setup, other relevant physical effects include phase change, thermal flow, and liquid-solid interactions. Such films are challenging to model, in particular because inertial effects may be relevant, and large contact angles require care when considering the long-wave formulation. Applications of nanoscale metal films are numerous, and the materials science community is actively pursuing more complex setups involving templated films and substrates, bimetallic films and alloys, and a variety of elemental film geometries. The goal of this review is to discuss our current understanding of thin metal film systems, while also providing an overview of the challenges in this research area, which stands at the intersection of fluid mechanics, materials science, and thermal physics.Fil: Kondic, Lou. New Jersey Institute of Technology; Estados UnidosFil: Gonzalez, Alejandro Guillermo. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigaciones en FÃsica e IngenierÃa del Centro de la Provincia de Buenos Aires. - Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Tandil. Centro de Investigaciones en FÃsica e IngenierÃa del Centro de la Provincia de Buenos Aires. - Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones CientÃficas. Centro de Investigaciones en FÃsica e IngenierÃa del Centro de la Provincia de Buenos Aires; ArgentinaFil: Diez, Javier Alberto. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigaciones en FÃsica e IngenierÃa del Centro de la Provincia de Buenos Aires. - Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Tandil. Centro de Investigaciones en FÃsica e IngenierÃa del Centro de la Provincia de Buenos Aires. - Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones CientÃficas. Centro de Investigaciones en FÃsica e IngenierÃa del Centro de la Provincia de Buenos Aires; ArgentinaFil: Fowlkes, Jason D.. University of Tennessee; Estados UnidosFil: Rack, Philip. University of Tennessee; Estados Unido
Luminescence Properties of Thin Film Ta2 Zn3 O8 and Mn Doped Ta2 Zn3 O8
Blue luminescence from TaZZn30g and green luminescence from Mn doped TaZZn30g has been observed under low voltage cathodoluminescent excitation, In this article , the luminescence mechanisms of TaZZn30g and Mn doped TaZZn30 g are discussed in detail. The results suggest that the intrinsic blue luminescence of TaZZn30g results from a metal-to-ligand transition, whereas the green luminescence of Mn doped TaZZn30g results from the Mn 4T 1-6A I transition. The suppression of the blue intrinsic luminescence in Mn doped TaZZn30g suggests that efficient energy transfer from the host material to the Mn occurs. This energy transfer phenomenon is also discussed by comparing the photoluminescence excitation spectra of both thin film materials. Finally, the relative efficiency versus voltage and current density is demonstrated and discussed pertaining to field emission device operation
Competition between collapse and breakup in nanometer-sized thin rings using molecular dynamics and continuum modeling
We consider nanometer-sized fluid annuli (rings) deposited on a solid substrate and ask whether these rings break up into droplets due to the instability of Rayleigh-Plateau-type modified by the presence of the substrate, or collapse to a central drop due to the presence of azimuthal curvature. The analysis is carried out by a combination of atomistic molecular dynamics simulations and a continuum model based on a long-wave limit of Navier-Stokes equations. We find consistent results between the two approaches, and demonstrate characteristic dimension regimes which dictate the assembly dynamics.Fil: Nguyen, Trung Dac. Oak Ridge National Laboratory; Estados UnidosFil: Fuentes-Cabrera, Miguel. Oak Ridge National Laboratory; Estados UnidosFil: Fowlkes, Jason D.. Oak Ridge National Laboratory; Estados UnidosFil: Diez, Javier Alberto. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de FÃsica Arroyo Seco; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: González, Alejandro G.. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de FÃsica Arroyo Seco; ArgentinaFil: Kondic, Lou. New Jersey Institute Of Technology; Estados UnidosFil: Rack, Philip D.. Oak Ridge National Laboratory; Estados Unido
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