Ion implantation through nanometer-scale apertures (nano-apertures) is a promising method to precisely position ions in silicon matrices, which is a requirement for next generation electronic and ...quantum computing devices. This paper reports the application of atom probe tomography (APT) to investigate the three-dimensional distribution of germanium atoms in silicon after implantation through nano-aperture of 10 nm in diameter, for evaluation of the amount and spatial distribution of implanted dopants. The experimental results obtained by APT are consistent with a simple simulation with consideration of several effects during lithography and ion implantation, such as channeling and resist flow.
Fe segregation are evident at the interface between β-Nb precipitates and α-Zr matrix by atom probe tomography (APT). Defects are observed at the interface by positron annihilation spectroscopy. It ...is also suggested that Fe was segregated to a concentration of several tens of percent at a local region at the interface, which is approximately one order of magnitude higher than APT and difficult to observe directly even using APT. Display omitted
Impurity segregation at the interface between β-Nb precipitates and α-Zr matrix in Zr-2.5wt.%Nb alloy was investigated by complementary analysis with positron annihilation spectroscopy (PAS) and atom probe tomography (APT). Fe segregation and Fe-decorated defects were found at the interface. PAS also suggested that Fe was segregated to a concentration of several tens of percent at a local region at the interface, which is approximately one order of magnitude higher than APT and difficult to observe directly even using APT.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
SUMMARY
The recent anatomical studies of the esophagus showed that submucosal longitudinal lymphatic vessels connect to the superior mediastinal and the paracardial lymphatics and lymphatic routes to ...periesophageal nodes originate from the muscle layer. Using clinical data for lymph node metastasis, we verify these anatomical bases to clarify the rational areas of lymph node dissection in esophageal cancer surgery. Analysis was performed on 356 consecutive patients who underwent esophagectomy with three‐field dissection. Patients were divided into those with tumor limited within the submucosal layer and those with tumor invading or penetrating the muscle layer. Frequency of node metastasis was compared according to supraclavicular, upper mediastinum, mid‐mediastinum, lower mediastinum, perigastric and celiac areas. In patients with tumor limited to the submucosal layer, node metastasis was more frequent in the upper mediastinum and perigastric area than the mid‐ or lower mediastinum. Even in patients with tumor located in the lower esophagus, node metastasis was more frequent in the upper mediastinum than the mid‐mediastinum or lower mediastinum. In patients with tumor located in the mid‐esophagus, node metastasis was more frequent in the supraclavicular area than the mid‐mediastinum or lower mediastinum. In patients with tumor invading or penetrating the muscle layer, node metastasis in the mid‐ and lower mediastinum increased dramatically, but was still less frequent than those in the upper mediastinum or the perigastric area. Postoperative survival curves did not differ among the involved areas. The most predictive factor associated with lymph node metastasis for postoperative survival was not the area of involved nodes, but the number of involved nodes by multivariate analyses. These clinical results verify recent anatomical observations. The lack of difference in survival rates among the involved areas suggests that these areas should be staged equivalently. For adequate nodal staging, the upper mediastinum should be dissected for the lower esophageal tumor and supraclavicular areas should be dissected for the mid‐esophageal tumor even in patients with tumor limited to within the submucosal layer.
Full text
Available for:
BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
The microstructures and the hardness of stainless steel weld overlay cladding of reactor pressure vessels subjected to neutron irradiation at a dose of 7.2×1019ncm−2 (E>1MeV) and a flux of ...1.1×1013ncm−2s−1 at 290°C were investigated by atom probe tomography and by a nanoindentation technique. To isolate the effects of the neutron irradiation, we compared the results of the measurements of the neutron-irradiated samples with those from a sample aged at 300°C for a duration equivalent to that of the irradiation. The Cr concentration fluctuation was enhanced in the δ-ferrite phase of the irradiated sample. In addition, enhancement of the concentration fluctuation of Si, which was not observed in the aged sample, was observed. The hardening in the δ-ferrite phase occurred due to both irradiation and aging; however, the hardening of the irradiated sample was more than that expected from the Cr concentration fluctuation, which suggested that the Si concentration fluctuation and irradiation-induced defects were possible origins of the additional hardening.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Two kinds of 9Cr-2W steels with and without the addition of 0.1 wt% Si were irradiated with neutrons up to a fluence of 4.8 × 1023 n/m2 at 563 K. Precipitates, dislocation loops, radiation-enhanced ...nano-clusters and radiation-hardening were studied using advanced electron microscopy and micro-hardness test. Si reduced the number density of dislocation loops, and therefore the extent of radiation-hardening decreased. It also favored the formation of silicide-like nano-clusters. In this study, the role of Si in neutron irradiated 9Cr-2W steels is discussed, and then extended to nano-clusters and irradiation-hardening.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In this study, we investigated the evaporation of carbon monoxide (CO) from silicon melt during crystal growth by evaluating the carbon concentrations in the crystals using photoluminescence (PL) ...spectroscopy. In order to achieve greater carrier lifetimes in magnetic-field-induced Czochralski (MCZ) silicon for high-power insulated-gate bipolar transistor (IGBT) devices, we focused on the reduction of carbon impurities in MCZ silicon, that act as heterogeneous nucleation sites for oxygen precipitates. To obtain MCZ silicon with a carbon concentration lower than that of floating-zone (FZ) silicon, it is necessary to prevent the back-diffusion of CO from the hot graphite components into the melt and promote CO evaporation from the melt. By promoting CO evaporation, we managed to grow 6-in. CZ silicon crystals with a carbon concentration lower than 1.0×1014atoms/cm3 at a solidified fraction of 80%.
•Evaporation of CO from silicon melt during crystal growth was investigated.•CO evaporation dominates CO incorporation upon increasing Ar flow rate.•CZ–Si, with a lower carbon content than FZ–Si, was grown by promoting CO evaporation.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The effect of thermal aging on microstructural changes in stainless steel submerged arc weld-overlay cladding of reactor pressure vessels was investigated using atom probe tomography (APT). In ...as-received materials subjected to post-welding heat treatments (PWHTs), with a subsequent furnace cooling, a slight fluctuation of the Cr concentration was observed due to spinodal decomposition in the δ-ferrite phase but not in the austenitic phase. Thermal aging at 400°C for 10,000h caused not only an increase in the amplitude of spinodal decomposition but also the precipitation of G phases with composition ratios of Ni:Si:Mn=16:7:6 in the δ-ferrite phase. The degree of the spinodal decomposition in the submerged arc weld sample was similar to that in the electroslag weld one reported previously. We also observed a carbide on the γ-austenite and δ-ferrite interface. There were no Cr depleted zones around the carbide.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Summary
Introduction
To provide target values for the manufacturers’ survey of the Japanese Society for Laboratory Hematology (JSLH), accurate standard data from healthy volunteers were needed for ...the five‐part differential leukocyte count. To obtain such data, JSLH required an antibody panel that achieved high specificity (particularly for mononuclear cells) using simple gating procedures. We developed a flow cytometric method for determining the differential leukocyte count (JSLH‐Diff) and validated it by comparison with the flow cytometric differential leukocyte count of the International Council for Standardization in Haematology (ICSH‐Diff) and the manual differential count obtained by microscopy (Manual‐Diff).
Methods
First, the reference laboratory performed an imprecision study of JSLH‐Diff and ICSH‐Diff, as well as performing comparison among JSLH‐Diff, Manual‐Diff, and ICSH‐Diff. Then two reference laboratories and seven participating laboratories performed imprecision and accuracy studies of JSLH‐Diff, Manual‐Diff, and ICSH‐Diff. Simultaneously, six manufacturers’ laboratories provided their own representative values by using automated hematology analyzers.
Results
The precision of both JSLH‐Diff and ICSH‐Diff methods was adequate. Comparison by the reference laboratory showed that all correlation coefficients, slopes and intercepts obtained by the JSLH‐Diff, ICSH‐Diff, and Manual‐Diff methods conformed to the criteria. When the imprecision and accuracy of JSLH‐Diff were assessed at seven laboratories, the CV% for lymphocytes, neutrophils, monocytes, eosinophils, and basophils was 0.5~0.9%, 0.3~0.7%, 1.7~2.6%, 3.0~7.9%, and 3.8~10.4%, respectively. More than 99% of CD45 positive leukocytes were identified as normal leukocytes by JSLH‐Diff.
Conclusions
When JSLH‐Diff method were validated by comparison with Manual‐Diff and ICSH‐Diff, JSLH‐Diff showed good performance as a reference method.
Full text
Available for:
BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
We present a microstructural study of a surveillance test specimen from a reactor pressure vessel steel of a Russian-type nuclear reactor after neutron irradiation, post-irradiation annealing and ...re-irradiation, using atom probe tomography (APT) and positron annihilation spectroscopy (PAS). The APT results showed the formation of Cu-rich solute nano-clusters (CRCs) during the initial irradiation and their subsequent coarsening during annealing. After re-irradiation, new CRCs have been observed. The irradiation-hardening almost recovered during annealing. However, by re-irradiation, hardening comparable to that by the initial irradiation was observed. The hardening due to the CRCs formed during the initial irradiation, estimated using the Russell–Brown model, was almost the same as that observed. However, the estimated hardening after the re-irradiation was about half of the measured one. The other hardening is attributed to the newly formed MDs by the re-irradiation, which was evidenced by PAS.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Radiation-induced segregation (RIS) of solute atoms at a grain boundary (GB) in 304 stainless steel (SS), neutron-irradiated to a dose of 24dpa at 300°C in the fuel wrapper plates of a commercial ...pressurized water reactor, was investigated using laser-assisted atom probe tomography (APT). Ni, Si, and P enrichment and Cr and Fe depletion at the GB were evident. The full-width at half-maximum of the RIS region was ∼3nm for the concentration profile peaks of Ni and Si. The atomic percentages of Ni, Si, and Cr at the GB were ∼19%, ∼7%, and ∼14%, respectively, in agreement with previously-reported values for neutron-irradiated SS. A high number density of intra-granular Ni–Si rich precipitates formed in the matrix. A precipitate-denuded zone with a width of ∼10nm appeared on both sides of the GB.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
