Search

For a system of a nano-sized Ni-Cu multilayer on a Ni substrate and hydrogen gas, many experimental results suggest an anomalous heat release that may be caused by low-energy nuclear reactions in condensed matter. In this paper, to clarify the structural change of the Ni-Cu multilayer with increasing temperature up to 900°C in an atmosphere with and without hydrogen, an in-situ X-ray diffraction (XRD) study using synchrotron radiation was performed for a system of 6 × {Ni(14 nm)/Cu(2 nm)}/α-SiO2(10 nm)/Si wafer (0.5 mm). The surface morphology observation and elemental analysis for the samples after the XRD measurements were performed using electron microscopy analyses. The XRD peaks from Ni were observed up to 600°C and satellite peaks were observed at 300–600°C, which indicates that the initial multilayer structure with a sharp interface was maintained up to approximately 600°C regardless of the atmosphere. After the temperature had increased to 900°C, the initial Ni-Cu multilayer became a single-layer of Ni-Cu alloy with the nominal composition when the system was heated in an atmosphere containing hydrogen; in a hydrogen-free atmosphere, it became a modified Ni-Cu multilayer, where the thickness of the Cu layer decreased to half of the initial value, and many particles were randomly distributed on the surface. For the Ni-Cu multilayer system, a baking pre-treatment at high temperatures in a hydrogen-free environment is considered advantageous to stimulate the anomalous heat effect if we assume that hydrogen diffusion through the bimetallic interface is one of the key factors that induce anomalous heat generation.

Abstract Background SPECT-derived dose estimates in tissues of diameter less than 3× system resolution are subject to significant losses due to the limited spatial resolution of the gamma camera. Incorporating resolution modelling (RM) into the SPECT reconstruction has been proposed as a possible solution; however, the images produced are prone to noise amplification and Gibbs artefacts. We propose a novel approach to SPECT reconstruction in a theranostic setting, which we term SPECTRE (single photon emission computed theranostic reconstruction); using a diagnostic PET image, with its superior resolution, to guide the SPECT reconstruction of the therapeutic equivalent. This report demonstrates a proof in principle of this approach. Methods We have employed the hybrid kernelised expectation maximisation (HKEM) algorithm implemented in STIR, with the aim of producing SPECT images with PET-equivalent resolution. We demonstrate its application in both a dual 68Ga/177Lu IEC phantom study and a clinical example using 64Cu/67Cu. Results SPECTRE is shown to produce images comparable in accuracy and recovery to PET with minimal introduction of artefacts and amplification of noise. Conclusion The SPECTRE approach to image reconstruction shows improved quantitative accuracy with a reduction in noise amplification. SPECTRE shows great promise as a method of improving SPECT radioactivity concentrations, directly leading to more accurate dosimetry estimates in small structures and target lesions. Further investigation and optimisation of the algorithm parameters is needed before this reconstruction method can be utilised in a clinical setting.

The spin Seebeck effect (SSE) converts thermally induced magnetization dynamics in magnetic materials to spin currents, but is so far an inefficient process. Here, the authors achieved resonant enhancement of the SSE voltage 700% larger than previously observed in Y3Fe5O12 by tuning the magnon lifetime via doping in $${{\rm{Lu}}}_{2}{{\rm{BiFe}}}_{4}{{\rm{GaO}}}_{12}$$ Lu2BiFe4GaO12 .