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In order to decrease ash deposition and hot corrosion in Waste-to-Energy plants, it is necessary to understand mechanisms of the ash deposition and the corrosion, and to develop new solutions. In this study, an adhesion force between an ash pellet and an alloy specimen were firstly measured to investigate the increase mechanisms of the ash deposition and the corrosion, using a tensile testing machine with an electrical furnace. Second, mass loss of the alloy specimens was measured as hot corrosion tests based on Japanese Industrial Standards. Third, phenomenon on the interface was evaluated with production amount of molten salts which were calculated by thermodynamic equilibrium. As a result, the adhesion force and the mass loss of all specimens increased with the interface temperature, and there was exact materials dependency, which indicated that a high chromium content design to improve corrosion resistance was valid also for decrease of the ash adhesion. Moreover, it was observed that mass loss of the alloy specimens with the ash sample collected from an actual boiler had a temperature dependence, and molten salts and accelerated oxidation induced by chlorides attacked the alloy specimens. In addition, generation of HCl gas and molten salts with temperature increase was confirmed with the thermodynamic equilibrium calculations. Judging from these results, starting temperature of the adhesion could be correspond to one which the alloy started to be severely corroded.

The influence of the sidewall damage on the thermal stability factor (Δ) of quad-interface magnetic tunnel junctions (quad-MTJs) was investigated through a string method-based micromagnetic simulation. The quad-MTJs consist of a reference layer/MgO-barrier/CoFeB/middle-MgO/CoFeB/MgO-cap, which has four CoFeB/MgO interfaces to enhance the interfacial perpendicular magnetic anisotropy for large Δ. Experimentally obtained magnetic parameters at room temperature [e.g., saturation magnetization (Ms), stiffness constant (As), interfacial perpendicular magnetic anisotropy constants (Ki), and exchange coupling (Jex)] in blanket multilayer films of the quad-MTJs were used in micromagnetic simulation. The influence of the sidewall damage on the quad-MTJs, which is difficult to be analyzed in the experimental way, was investigated. The quad-MTJs without damaged layers having relatively higher Ki show the split of the energy barrier into two, resulting in a decrease in Δ. When the decrease in magnetic anisotropy energy (Eani) is more than the increase in the static magnetic energy (Esta), the antiferromagnetically (AF) coupled state of two free layers is formed at the midpoint to minimize the total energy (Eall). This causes the split of the energy barrier. The sidewall damage plays a role in lowering Ki in each layer, consequently avoiding the formation of the AF state. Note that the value of Δ with the sidewall damage, which shows the unified energy barrier, is comparable to non-damaged Δ, which shows the split of the energy barrier; these quad-MTJs have the same volume of free layers.

Some ash particles in municipal and industrial waste adhere to heat exchanger tube surfaces, which causes problems such as heat-transfer inhibition, high temperature corrosion and low utilization in Waste-to-Energy (WtE) plants. The objective of this study is to develop new surface treatment materials and techniques which can decrease the ash deposition and the corrosion, and to provide further understanding of ash deposition mechanisms for various metal surfaces in WtE plants. First, the adhesion force between an ash pellet, which was made of ash sampled from a WtE plant, and an alloy specimen was measured to investigate the mechanisms that increase ash deposition. Second, the adhesion interfaces of the specimens were analyzed after the adhesion force measurement. The result was that the adhesion forces of all specimens increased with the interface temperature, and there was a clear temperature dependency on the force. The adhesion force of the ash pellet to stainless steel AISI 430 and 304 were larger than to 310S or to a surface-modified AISI 304 due to a lower Cr content. In particular, there was a correlation between Ni + Cr content in the surface of the alloy specimens and the adhesion force. Moreover, the analysis of AISI 304 with SEM-EDS have shown that the active oxidation involved in interface reactions. In addition, analysis of the adhesion interface and the thermodynamic equilibrium calculation supported the results of the adhesion measurements. Specifically, results of the calculations were that partial pressure of Fe-chloride gases are higher than that of Ni or Cr-chloride gases.

In solid-fuel fired boilers, ash deposition on heat-transfer surfaces can cause operational problems. It is important to predict ash-deposition properties based on the ash composition of the solid fuel in advance. However, general prediction methods do not always agree with actual ash deposition under conditions of actual combustion. In this study, we first developed a new sampling system that can collect ash particles during the combustion of mixed bituminous coal samples in a boiler; the composition of the sampling ash was evaluated, and the composition that affect ash-deposition properties were identified. Next, the ash composition of the coal samples was evaluated as a mineral with CCSEM. These results were summarized in order to identify which mineral particles were strongly related to ash-deposition properties, and a new prediction method for ash deposition based on the actual combustion state was investigated. The main conclusions were drawn as follows: (1) Iron was condensed in the early-stage ash deposition of the secondary superheater tube area, and there were differences in the amount of iron between the sampling-ash deposition and the ash in the bituminous coal. (2) The amount of iron in the ash deposition could be predicted with high accuracy by using the amount of included iron oxide, pyrite, Fe-Si (iron silicate), and pyrrhotite. (3) The method developed in this study can be applied to boilers with various solid fuels such as coal, woody biomass, and/or waste. This will contribute to improving the prediction accuracy of ash-deposition properties.

The influence of magnetic damages at the sidewall of perpendicular magnetic tunnel junctions (p-MTJs), which are the core devices of spin-transfer-torque magnetoresistive random-access memory (STT-MRAM), is discussed based on the thermal stability factor, Δ, double-logarithmic plot of normalized switching energy barrier, E, and saturation magnetization, Ms, and their exponential slope, n. Δ was calculated using the string method under the simulation conditions of domain wall motion switching. n increased with the increasing thickness of the damaged layer of the sidewall. Notably, the sidewall damage can be explained by the reduction in Ms and exchange stiffness constant, As, rather than the interfacial perpendicular anisotropy. The findings of this study are important for controlling and improving the process damage in the mass production of p-MTJs in STT-MRAM.

Abstract Comprehensive crystal structural study is performed for BiFeO3 (BFO) film grown on KTaO3 (KTO) substrate using transmission electron microscopy (TEM) and x-ray diffraction (XRD). Nano-beam electron diffraction (NBED) combined with structure factor calculation and high resolution TEM images clearly reveal that the crystal structure within BFO thin film is rhombohedral BFO, i.e., bulk BFO phase. Epitaxial relationship found by NBED indicates the BFO film grows in a manner that minimizes lattice mismatch with KTO. It further suggests BFO film is under slight biaxial tensile stress (~0.35%) along in-plane direction. XRD reveals BFO lattice is under compressive stress (~1.6%), along out-of-plane direction as a result of the biaxial tensile strain applied along in-plane direction. This leads to Poisson’s ratio of ~0.68. In addition, we demonstrate (1) why hexagonal notation rather than pseudocubic one is required for accurate BFO phase evaluation and (2) a new XRD method that shows how rhombohedral BFO can readily be identified among other phases by measuring a rhombohedral specific Bragg’s reflection.

We report a histologically pure stage 1 seminoma with an elevated human chorionic gonadotropin (hCG). A 38 year-old man was referred for the evaluation of the left testicular swelling. He showed an elevated serum hCG level of 25,265 mIU/ml with normal a fetoprotein and lactate dehydrogenase. Imaging showed heterogeneous tumor without any metastatic lesions. We conducted 4 courses of chemotherapy before detecting hCG nadir. The final pathological report showed pure seminoma with syncytiotrophoblastic cells but no choriocarcinoma components. The patient remains disease free until present time. The case raised several questions regarding diagnosis and treatment strategy for bulky testicular seminoma.

Background and study aims: Intramucosal vascular density differs between differentiated and undifferentiated type gastric carcinomas. This study aimed to evaluate the microvascular density characteristics of these two types of carcinoma using magnifying endoscopy with narrow-band imaging (ME-NBI). Patients and methods: In total, 42 differentiated and 10 undifferentiated types were evaluated. The microvessels observed using ME-NBI were extracted from stored still images and the microvascular density in the two carcinoma types was analyzed. Histological vascular density in resected specimens was also evaluated using CD34 immunostaining. Results: There were significant differences between the microvascular density in the differentiated and undifferentiated types of carcinoma (10.02 ± 4.72 % vs 4.02 ± 0.40 %; P

The 10 at.% Co-substituted BiFeO3 films (of thickness 50 nm) were successfully prepared by radio frequency (r.f.) magnetron sputtering on SrTiO3 (100) substrates with epitaxial relationships of [001](001)Co-BiFeO3//[001](001)SrTiO3. In this study, a single phase Co-substituted BiFeO3 epitaxial film was fabricated by r.f. magnetron sputtering. Sputtering conditions such as Ar, O2 gas pressure, annealing temperature, annealing atmosphere, and sputtering power were systematically changed. It was observed that a low Ar gas pressure and low sputtering power is necessary to suppress the formation of the secondary phases of BiOx. The Co-substituted BiFeO3 films were crystalized with post-annealing at 600 °C in air. The process window for single phase films is narrower than that for pure BiFeO3 epitaxial films. By substituting Fe with Co in BiFeO3, the magnetization at room temperature increased to 20 emu/cm3. This result suggests that Co-substituted BiFeO3 films can be used in spin-filter devices.

Although nephroblastoma is the commonest renal tumor of childhood, it is rare in adults. In cases of predominantly epithelial type occurring in adulthood, it might be difficult to distinguish it from papillary renal cell carcinoma and metanephric adenoma. Here, we report three cases of adult epithelial nephroblastoma in 24-, 76-, and 21-year-old females. Histologically, the tumors were composed of papillotubular architectures of small and uniform tumor cells with high nucleocytoplasmic ratio without blastemal element. Immunohistochemically, the tumor cells were positive for WT-1 and CD57 but negative for AMACR, which was helpful to exclude the possibility of papillary renal cell carcinoma. Metanephric adenoma is a benign tumor, which can be distinguished by the observation of the cellular atypism and growth pattern. However, nephroblastoma with predominant epithelial element mimics the malignant counterpart of metanephric adenoma, that is, “metanephric adenocarcinoma.”

We have investigated the magnetic and electrical properties of iron nitride films containing both amorphous matrices and nanocrystalline grains. It is found that both the number and the size of the grains in the amorphous matrix increase as the film thickness increases. The grain is confirmed to have an epsilon-Fe3N structure and the grain size varies in the range of 10–300 nm. The saturation magnetization and the coercivity increase as the number and the size of the grains increase. The electrical resistivity of the iron nitride films is higher than that of the iron film. It is considered that the amorphous matrices cause the high resistivity in the iron nitride films.