Application of steel channels as stiffeners in bolted moment connections

This paper proposes a stiffening method to meet some architectural needs. This method uses bolted channels as alternatives to both continuity and doubler plates in bolted moment-resistant beam-to-column connections. The present study investigates the performance of channels as stiffeners to: increase yield load in the tension zone of connection, gradually increase overall moment capacity of connection, and avert shear failure of the column web panel zone. We conducted experiments to examine the tension region of the connection loaded from T-stubs. The moment capacity of full connection was predicted by considering T-stub idealization and shear effects on the column web panel. T-stub tensile behavior and overall connection behavior were also monitored using three-dimensional finite element simulations in ANSYS simulation software because this problem is three-dimensional in nature. Effects of geometrical and material non-linearities on interaction among connecting members should be clarified. This study showed marked strength improvement in connection by use of channels. The performance of channel stiffeners was examined through comparison of results.     

Study on degradation process of polymer electrolyte by solution analysis

Degradation process of Nafion which is one of the polymer electrolyte generally used for polymer electrolyte membrane fuel cell was investigated by solution analysis and structural analysis of eluted species. Nafion degraded by gamma-ray irradiation and heat treatment was immersed in distilled water and the solutions were analyzed using ion chromatograph, total organic carbon (TOC) analyzer, and inductively coupled plasma atomic emission spectrometer (ICP-AES). The solutions after the Fenton reaction were also analyzed with the same methods. Proton, sulfide ion, fluorine ion and organic carbon were eliminated into the solution, and their ratio was changed depending on the degradation method. To determine the eliminated species to the solution, structural analysis of concentrated dissolved species was performed using FT-IR. As the results, the initial process of degradation was detected sensitively in solution analysis compared with membrane analysis, and difference of the degradation process under different conditions was clearly observed. It was also found that new functional group COOH was formed in the eliminated species. These results showed that solution analysis are very simple yet powerful methods to elucidate the degradation process, which can also be applied to actual fuel cell operation to track minute changes in the polymer electrolyte.     

Characteristic transfer function matrix-based linear feedback control system analysis and synthesis

In this article, the concept of control system synthesis via a method using the characteristic transfer function matrix (CTFM), is explained. Then, the formal definition of CTFM and the associated concept of connectivity are presented. Next, CTFM-based control system analysis and synthesis are discussed, together with the derivation of the necessary and sufficient conditions for the realisation of a proper controller. A summary of the design procedure is presented and three design examples are introduced, in order to illustrate this procedure. Finally, the main conclusions to the work are presented.     

An analysis of limit cycle and velocity history in Mazda’s <Emphasis Type="Italic">keiretsu</Emphasis>

This article proposes the use of limit cycle theory and velocity history as effective tools for analyzing the behavior of members of an organized network. Specifically, the limit cycle and velocity history of firms in the Kansai Yokokai, one of the three major groups of suppliers that constitute Mazda’s keiretsu, are examined using a new analytical approach. Based on the data obtained, the organizational behavior of the suppliers is subsumed into four categorical patterns, each of which is related to the limit cycle and velocity history. The research implications, as well as the weakness of the limit cycle, are also discussed.     

Ultrasound-assisted capillary microreactor for aqueous–organic multiphase reactions

A simple capillary microreactor was tested as a potential reactor to carry out a multiphase reaction. The hydrolysis of benzyl chloride in a biphasic system was investigated. The capillary microreactor was irradiated by 28 kHz ultrasound at different temperatures, capillary lengths and phase flow rates. It was found that the combination of microreactor technique and the ultrasound irradiation provides a promising protocol for process intensification. Under sonication conditions, higher conversions were obtained compared to silent conditions. The presence of ultrasound has affected the multiphase slug size and promoted better internal circulation within these slugs. Similar reactivities were noticed at higher temperature for both sonication and silent conditions.     

Development of novel PZT thin films for active sliders based on head load/unload on demand systems

 Micromachined active sliders based on head load/unload on demand systems is an interesting concept technology for ultra-high magnetic recording density of more than 100 Gb/in². The active sliders that we proposed use PZT thin films as a microactuator and control the slider flying height of less than 10 nm. It is necessary to develop high performance microactuators in order to achieve active sliders operating at very low applied voltage. This paper describes the development of novel PZT thin films for active sliders. The sol–gel fabrication process for PZT thin films is developed and the fundamental characteristics for the PZT thin films are investigated. It is confirmed that the PZT thin films have good ferroelectric properties. Furthermore, novel thin film microactuators are proposed. The feature is that the sol–gel PZT thin films (thickness 540 nm) are deposited on the sputtered PZT thin films (thickness 300 nm) fabricated on bottom Pt/Ti electrodes. Therefore, the novel thin films consist of a thermal SiO₂ layer and the sputtered and sol–gel PZT thin films layers sandwiched with upper Pt and bottom Pt/Ti electrodes on a Si slider material. Fabricating the diaphragm microactuator, the piezoelectric properties for the novel composite PZT thin films are studied. As a result, the piezoelectric strain constant d ₃₁ for the novel PZT thin films is identified to be 130 × 10⁻¹² m/V. This value is higher than conventional monolithic PZT thin films and it is found that the novel composite PZT thin films have the good piezoelectric properties. This suggests the feasibility of realizing active sliders operating at lower voltage under about 10 V. Received: 22 June 2001/Accepted: 17 October 2001     

Acute kidney injury in a postpartum woman with paroxysmal nocturnal hemoglobinuria: A case report and literature review

Paroxysmal nocturnal hemoglobinuria is a rare clonal hematopoietic stem cell disorder characterized by intravascular hemolysis, hemoglobinuria, and inflammatory thrombotic state. Intravascular hemolysis in paroxysmal nocturnal hemoglobinuria (PNH) can lead to acute and chronic renal injury through hemoglobin‐mediated toxicity. A 32‐year‐old pregnant woman with myelodysplastic syndrome was admitted to our hospital with severe preeclampsia. Shortly after an urgent caesarean section, she became obtunded and showed signs of acute kidney injury (AKI) with anuria, severe intravascular hemolysis, and hypermagnesemia. She was diagnosed with PNH with a positive Ham test and flow cytometry analysis. Renal magnetic resonance imaging revealed decreased signal intensity in the renal cortex due to hemosiderin deposition. Hemodialysis, plasma exchange, and administration of corticosteroids ameliorated her clinical condition and renal function. This case illustrates that careful management is required to prevent postpartum AKI in pregnant women with PNH.     

Verification of insulation tests for traction motors

More than 30,000 thousand dc motors are used by the Japan Railway group companies alone as traction motors for railway vehicles. Insulation breakdown of armatures is one of the most important problems in traction motors. Therefore, various insulation tests are carried out for each motor in overhaul. The methods for insulation tests were determined more than 30 years ago. As insulating materials and the method to compose these materials have progressed in recent years, it is important to research what kinds of insulation tests are suitable for traction motors. We estimated the effects of various insulation tests by carrying out insulation breakdown tests for more than 150 motors. This paper describes the results of the study. © 1999 Scripta Technica. Electr Eng Jpn, 129(2): 90–97, 1999     

A saturable tissue-angiotensin I converting enzyme (ACE) binding model for the pharmacokinetic analysis of imidapril, a new ACE inhibitor, and its active metabolite in human

In order to obtain a rational explanation and analytical method of the unique pharmacokinetic behaviors of imidapril and imidaprilat in human, a new pharmacokinetic model was designed by introducing a saturable-reversible angiotensin I converting enzyme (ACE)-imidaprilat binding process and a linear imidapril-imidaprilat conversion process. According to the new model, six differential equations were given which considered the mass balance of both compounds in each component. Various pharmacokinetic parameters were estimated by the simultaneous curve fitting method using the plasma concentration data and the urinary excretion data of imidapril and imidaprilat in a multiple dosing study of healthy human volunteers. To validate the value of each parameter, this pharmacokinetic model was also applied to analyze the various plasma concentration data of both compounds in the single dosing studies with four different dosages, 2.5,5, 10, and 20 mg. Excellent curve fitting was obtained in every case, suggesting that the proposed pharmacokinetic model is applicable for predicting the plasma concentrations of imidapril and imidaprilat under various dosage conditions of clinical use.     

CD40 ligation prevents neonatal induction of transplantation tolerance

To investigate the consequences of CD40 engagement on the neonatal induction of transplantation tolerance, BALB/c mice were injected at birth with (A/J x BALB/c) F1 spleen cells together with activating anti-CD40 mAb and grafted 4 wk later with A/J skin. Whereas A/J allografts were accepted in mice neonatally injected with F1 cells and control Ab, they were acutely rejected in mice injected with F1 cells and anti-CD40 mAb. Neonatal administration of anti-CD40 mAb resulted in enhanced anti-A/J CTL activity, increased IFN-gamma, and decreased IL-4 production by donor-specific T cells in vitro. Experiments using anti-cytokine mAb and IFN-gamma-deficient mice demonstrated that CD40 ligation prevents neonatal allotolerance through an IFN-gamma- and IL-12-dependent pathway. Finally, we found that newborn T cells express less CD40L than adult T cells upon TCR engagement. Taken together these data indicate that insufficiency of CD40/CD40L interactions contribute to neonatal transplantation tolerance.