Development of atom probe specimen preparation techniques for specific regions in steel materials

More elaborated specimen preparation techniques for atom probe analysis were developed using a focused ion beam with a sample lift-out system so as to expand the application field in steel materials. The techniques enable atom probe analysis of sample steel at site-specific regions of interest. The preferable form of the needle specimen was provided by electrostatic field calculation using a finite element method. The new techniques were applied to the observation of a bainite-ferrite interface in a low carbon steel, and atomic-scale partitioning and segregation of alloying elements at the phase interface were directly observed in three dimensions.     

Expression of tropomyosin alpha 4 chain is increased in esophageal squamous cell carcinoma as evidenced by proteomic profiling by two-dimensional electrophoresis and liquid chromatography-mass spectrometry/mass spectrometry

To identify proteins associated with esophageal carcinogenesis, we performed protein profiling of 16 esophageal squamous cell carcinomas (ESCCs) and paired noncancerous tissues by 2-DE and MS/MS. In cancerous tissues, three spots showed significant up-regulation in the amount of protein, while eight spots were significantly down-regulated. The identities of the spots were determined by PMF with LC-MS/MS and were confirmed by immunoblotting. The up-regulated proteins were tropomyosin alpha 4 chain, transgelin, and pyruvate kinase. The down-regulated proteins were serum albumin precursor, isoforms of annexin A1, tropomyosin beta chain, 14-3-3 protein sigma, and isoforms of serotransferrin precursor. In all 16 cases, up-regulation of the tropomyosin alpha 4 chain was confirmed by immunoblotting. Localization of the tropomyosin alpha 4 chain in ESCC cells and adjacent fibroblasts was confirmed by immunohistochemistry.     

High‐luminance 1.8‐mm‐pixel‐pitch CNT‐FED for ubiquitous color character displays

Abstract— A high‐luminance 1.8‐mm‐pixel‐pitch CNT‐FED for color character displays has been developed. The display panel has 32 × 256 color pixels, and the subpixel size is 0.6 × 1.8 mm. The display panel can provide good visibility when installed even in outdoor locations. The power consumption is low enough for the display to be battery driven. The practical application is the display of important messages regarding the evacuation from disaster areas, even under emergent no‐power conditions similar to the messages on vending machines.     

Ultra-sensitive high-speed density measurement of the “piston effect” in a critical fluid

In order to conduct a detailed investigation of the piston effect, the peculiar heat transportation phenomenon in critical fluids, an ultra-sensitive high-speed density measurement system was developed using a very thin heater, a sensitive interferometer and a large-capacity high-speed data acquisition system. As the first step of the investigation, an experiment was conducted to measure the velocity of sound in CO2 near its critical point. Short heat pulses suppressing the disturbance of natural convection were applied to a small cell filled with almost-critical CO2 fluid and were detected by the measurement system. Because the pulses propagated through the cell at the velocity of sound and were reflected several times between the cell walls, the velocity could be precisely determined by measuring the time intervals between successive reflections. The resulting velocity profile versus temperature showed good agreement with theoretical prediction and numerical simulations. This result validated the density measurement system, and it is considered that the measurement system will be a very effective tool for further studies on critical phenomena with the aid of numerical simulation.     

Improving the creep properties of 9Cr-3W-3Co-NbV steels and their weld joints by the addition of boron

New ferritic steels with a controlled addition of boron have been developed recently for ultrasuper-critical fossil power plants. These steels possess excellent creep resistance compared to conventional steels like P91, P92, P122, etc., and this has been attributed to the delay in coarsening of the carbides during creep owing to partial replacement of carbon by boron in these carbides. However, the susceptibility of the weld joints of the boron-containing ferritic steels to type IV cracking, which significantly brings down the rupture life of the weld joints, has not been investigated so far. In the present work, the creep properties of recently developed 9Cr-3W-3Co-NbV steels with boron contents varying from 47 to 180 ppm and of their weld joints have been studied. Creep tests were carried out at 923 K in the stress range of 140 to 80 MPa. Specimens were examined for particle coarsening using field-emission scanning electron microscopy, and the boron content in the precipitates was estimated using field-emission auger electron spectroscopy (FE-AES). The grain size of the parent metal and the heat-affected zone (HAZ) were estimated using electron backscattered pattern (EBSP) imaging. Results showed that the creep properties of the steels with 90 and 130 ppm boron and of their weld joints are superior to those of the P92 steels and its weld joints. Further, no weld joints exhibited type IV cracking. No significant coarsening of the carbides was observed, not only in the parent metal but also in the HAZ of the steels with ≥90 ppm of boron. In addition to the delay in carbide coarsening, the large prior-austenite grain size of the parent metal and the absence of a conventional fine-grained HAZ (FGHAZ) in the weld joints also seem to have a beneficial effect on improving the creep properties of these steels and their weld joints.     

Solutions for the Portfolio Selection Problem with Interval and Fuzzy Coefficients

In this paper we consider portfolio selection problem with interval and fuzzy objective function coefficients as a kind of multiple objective problems including uncertainties. For this problem two kinds of efficient solutions are introduced: possibly efficient solution as an optimistic solution, necessarily efficient solution as a pessimistic solution. Investigating the properties of two efficiency conditions by means of preference cones and feasible region, we discuss that the two kinds of solutions can be identified with the sets of combinations of lower or upper bounds of intervals. This revised version was published online in June 2006 with corrections to the Cover Date.     

Membrane formation via phase separation induced by penetration of nonsolvent from vapor phase. I. Phase diagram and mass transfer process

The isothermal phase diagram for poly(vinylidene fluoride)/dimethyl formamide/water system was derived. The binodal and spinodal were calculated based on the Flory–Huggins theory and the calculated binodal was approximately in agreement with the experimental data of the cloud points. The isothermal crystallization line was also obtained according to the theory of melting point depression. Mass transfer of the three components during membrane formation by the precipitation from the vapor phase has been analyzed. During this process, phase separation of the polymer solution is induced by the penetration of water vapor in the solution. The calculated result on the changes of the cast film weights indicated the good agreement with the experimental data. The time‐course of the polymer concentration profile in the film was calculated for various cases of different humidity of the vapor phase and different initial polymer concentration. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 159–170, 1999     

Role of Palatine Tonsil and Epipharyngeal Lymphoid Tissue in the Development of Glomerular Active Lesions (Glomerular vasculitis) in Immunoglobulin A Nephropathy

Hematuria is an essential symptom of immunoglobulin A nephropathy (IgAN). Although the etiology of hematuria in IgAN has not been fully elucidated, it is thought that the rupture of the glomerular basement membranes caused by intra-capillary leukocyte influx, so-called glomerular vasculitis, is the pathological condition responsible for severe hematuria. Glomerular vasculitis are active lesions that exist in the glomeruli of acute phase IgAN and it is important because it is suspected to make the transition to segmental glomerular sclerosis (SGS) as a repair scar lesion in the chronic phase, and the progression of SGS would eventually lead to glomerular obsolescence. Worsening of hematuria concomitant with acute pharyngitis is common in patients with IgAN; therefore, elucidating the relationship between the immune system of Waldeyer’s ring, including the palatine tonsil and epipharyngeal lymphoid tissue, and the glomerular vasculitis may lead to understanding the nature of IgAN. The epipharynx is an immunologically activated site even under normal conditions, and enhanced activation of innate immunity is likely to occur in response to airborne infection. Hyperactivation of innate immunity via upregulation of Toll-like receptors in the interfollicular area of the palatine tonsil and epipharyngeal lymphoid tissue, followed by enhanced fractalkine/CX3CR1 interactions, appears to play an important role in the development of glomerular vasculitis in IgAN. As latent but significant epipharyngitis is present in most patients with IgAN, it is plausible that acute upper respiratory infection may contribute as a trigger for the innate epipharyngeal immune system, which is already upregulated in a chronically inflamed environment. Given that epipharyngitis and its effects on IgAN are not fully understood, we propose that the so-called “epipharynx–kidney axis” may provide an important focus for future research.     

Effect of surface treatment of pitch-based carbon fiber on mechanical properties of polyethernitrile composites

The effect of surface treatment of pitch-based carbon fiber on a new engineering thermoplastic resin, polyethernitrile, was investigated. Pitch-based carbon fiber (CF) was treated in two separate oxidizing solutions. In the first method, a nitric acid solution was used as an oxidizing agent. In the second method, a hydrogen peroxide solution was used. Both methods demonstrated that each of these solutions was a satisfactory oxidizing agent for the pitch-based CF. These treated fibers were combined with polyethernitrile polymer by the powder impregnation method, and unidirectional laminates were obtained. Improvements in both interlaminar shear strength and transverse flexural strength were achieved. The laminates fabricated from the treated CF maintained the same longitudinal flexural strength as laminates from the untreated control. In addition, scanning electron micrographs of composite fracture surfaces also showed excellent bonding of the treated fiber.     

A novel utility‐interactive electrical energy storage system making use of electrical double‐layer capacitors and an error tracking mode PWM converter

A novel electrical energy storage system interacting with a commercial ac network was designed and experimentally evaluated. It consists of an ac/dc converter modulated by a constantly sampled PWM scheme called Error Tracking Mode and electrical double‐layer capacitors paralleled by monitor circuits. The ac ratings are 100 V, 500 W, and 1.0 power factor. The storage capacity is designed to be 500 Wh. Since the voltage of the capacitor bank decreases to one‐fourth with discharge, a reversible step‐down chopper is inserted between the bank and the ac/dc converter. ac/dc converter efficiencies of 95.6 and 95.8% were obtained in rectifier operation and inverter operation, respectively. The average switching frequencies were set between 10.4 and 11.2 kHz for all operating conditions. Chopper efficiencies of 94.6% and 93.1% were measured in the charge and discharge modes, respectively. The storage efficiency of the capacitor bank was 89.8%. This novel utility‐interactive energy storage system has demonstrated good and rapid performance. © 2000 Scripta Technica, Electr Eng Jpn, 133(2): 52–62, 2000