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This study investigated the local preliminary hardening of ferrite near ferrite–martensite interfaces in dual-phase (DP) steel. Geometrically necessary dislocations (GNDs), generated in the case of interfacial misfit between different phases, may cause preliminary hardening around such interfaces. Firstly, finite-element simulations of nanoindentations were conducted using an ideal cylindrical DP model without preliminary hardening around the ferrite–martensite interface. The simulations indicated gradually decreasing nano-hardness with increasing distance from the ferrite–martensite interface. Second, nano-hardness measurements of ferrite near the ferrite–martensite interface were performed for laboratory-made DP steel containing 10 vol.% martensite. The measurements were consistent with the simulation without preliminary hardening around the interface. That is, interfacial preliminary hardening of ferrite was not indicated by our measurements. The GND density, which has been reported to cause preliminary hardening around the interface, supported this result. The density on ferrite was increased around the interface, but the area was very small compared with the nanoindentation size. We conclude that another hardening mechanism, e.g., GND accumulation under a high strain gradient around the interface, acts as a microstructural local strengthening factor in DP steel deformation.

In this study, finite element simulations synchronized with in-situ tensile tests have identified microstructural damage models in a 600 MPa grade dual-phase steel with 10% martensite volume fraction. Firstly, in-situ tensile tests have been carried out on a double-notched, flat-plate, tensile specimen. These experiments have shown that the damage in this steel is dominated, up to moderate tensile strains, by fracture of the martensite islands and decohesion at the martensite/ferrite interfaces. Secondly, FE simulations have been conducted, by using 2.5D meshes that were adjusted to the real shape of the martensite islands, as revealed by the micrographs. The ductile fracture of the martensite was described by a three-parameter fracture envelope defined by Bao and Wierzbicki, where the equivalent strain to fracture is expressed as function of the stress triaxiality. The stiffness of the ferrite/martensite interfaces has been described by a four-parameter cohesive model of Xu-Needleman type. The comparison of the experimentally determined sequence of damage events with the FE simulations has allowed adjusting the damage parameters of the model and validating them up to equivalent plastic strains exceeding locally 0.60. After determination of the damage parameters, the event sequence of martensite fracture and ferrite/martensite decohesion, as well as the pattern of the strain localization in the ferrite phase, were quite satisfactorily predicted by the FE simulations. Furthermore, the results obtained have shown that the martensite fracture and the interface decohesion have a significant influence on the stress and strain partitioning between the two phases, and hence also on the pattern and intensity of the strain localization and on the void growth and coalescence during the subsequent deformation stages.

In this study, the effects of shearing clearance and shearing angle on stretch-flange formability are investigated. The saddle-type forming test is adopted for this investigation. A notch-type shearing line, which comprises straight and circular arcs, is used for this test. The results show that stretch-flange formability is improved in narrow clearances. This tendency is different from that obtained by the hole expansion test, wherein stretch-flange formability is improved in large clearances. This improvement might be caused by the increase in the area of the fractured surface in narrow clearances. Generally, the larger the fractured surface, the smaller the work hardening on a sheared edge. Furthermore, the investigation reveals the existence of an optimum shearing angle for excellent stretch-flange formability. FE simulation shows that the optimum shearing angle increases hydrostatic stress in materials during shearing. Compressive stress across the material thickness is mainly affected by shearing angle. The result of the analysis suggests that the optimum shearing angle increases the area of the fractured surface to improve stretch-flange formability.

Oxidation of 2-hydroxy-9,10-dialkynylanthracenes resulted in highly regioselective dimerization to furnish metastable dearomatized 1,4-diketones rather than stable aromatic diols. The 1,4-diketones were converted to oxahelicenes, which exhibited strong fluorescence both in solution and solid state as well as chiroptical properties.

This study proposes separation control investigation using a Dielectric Barrier Discharge (DBD) plasma actuator on a NACA0015 airfoil over a wide range of Reynolds numbers. The airfoil was a two dimensional NACA0015 wing model with chord length of 200mm. Reynolds numbers based on the chord length were ranged from 252,000 to 1,008,000. A plasma actuator was installed at the leading edge and driven with AC voltage. Burst mode (duty cycle) actuations, in which nondimensional burst frequency F+ was ranged in 0.1–30, were applied. Time-averaged pressure measurements were conducted with angles of attack from 14deg to 22deg. The results show that initial flow fields without an actuation can be classified into three types; 1) leading edge separation, 2) trailing edge separation, and 3) hysteresis condition between 1) and 2), and the effect of burst actuation is different for each above initial condition.

A kriging-based genetic algorithm called efficient global optimization (EGO) was employed to optimize the parameters for the operating conditions of plasma actuators. The aerodynamic performance was evaluated by wind tunnel testing to overcome the disadvantages of time-consuming numerical simulations. The proposed system was used on two design problems to design the power supply for a plasma actuator. The first case was the drag minimization problem around a semicircular cylinder. In this case, the inhibitory effect of flow separation was also observed. The second case was the lift maximization problem around a circular cylinder. This case was similar to the aerofoil design, because the circular cylinder has potential to work as an aerofoil owing to the control of the flow circulation by the plasma actuators with four design parameters. In this case, applicability to the multi-variant design problem was also investigated. Based on these results, optimum designs and global design information were obtained ...

In this study, we numerically analyzed the effects of martensite elongation (i.e., fibering) and banding on the macroscopic stress-strain curves and microscale damage evolution in dual-phase (DP) steels using three-dimensional finite element analyses to obtain insights into designing more ductile, higher-strength DP steels. Representative volume elements (RVEs) composed of equiaxed, elongated, and banded martensite grains embedded within a ferrite matrix were employed for the simulations. A modified Voronoi diagram technique was applied to generate these virtual martensite grains in the RVEs. The analyses revealed that equiaxed martensite concentrated strain in certain parts of the ferrite phase, whereas martensite elongation caused a homogenous strain concentration in the ferrite phase, which, in turn, acted as a newly generated hard phase. Therefore, the tensile strength was lower than for equiaxed grains. On the other hand, martensite banding did not decrease the ferrite strain concentration, but induced a high degree of strain partitioning in the martensite grains. This behavior resulted in remarkably high yield stresses over the entire strain region, including at the peak values. Martensite elongation also resulted in a high degree of damage in the martensite grains. Nevertheless, the elongated martensite bands exhibited smooth surfaces with few concavities. These bands prevented damage concentration during martensite elongation and banding, in contrast to the case for the banding of the equiaxed martensite grains.

Dehydrative coupling between indoles and isatins provided indolylindolinones in good yields as novel dyes with wide-range absorption due to intramolecular charge-transfer interactions. The HOMO and...

The purpose of the research is to develop the method of designing and manufacturing a sensitivity-adjustable three component force balance utilized in a wind tunnel experiment. This paper describes the characteristics of the force balance and its application to wind tunnel testing. In this study, an oval-shape force balance is newly introduced and the characteristics are investigated by FEM analysis and force balance calibration. Also, the validity of the force balance is investigated in a wind tunnel experiment. As a result, the sensitivity of the oval-shape force balance can be adjusted by changing the aspect ratio and aerodynamic forces can be measured in a wind tunnel experiment using it. In conclusion, we can develop the sensitivity-adjustable force balance by applying oval shape and the force balance can be used in a wind tunnel experiment. It is recommended that the strain gauge position and its paste procedure be still improved.

Efficient global optimization (EGO), based on the expected improvement maximization of the Kriging model, is a suitable optimization method for designs based on time-consuming evaluations such as computational fluid dynamics. However, the original formulation of EGO can find only one additional sample point after an initial sample point is acquired for the initial Kriging model construction. Therefore, the efficiency of EGO is decreased even if the designer is able to evaluate several designs using a large parallel computer because additional samples can only be obtained sequentially through the additional sampling process. In this study, a multiple additional sampling method is proposed to improve the efficiency of the additional sampling process in EGO while maintaining the performance of exploration based on EI maximization. The design performance of EGO with MAS is investigated by solving a test problem first, and then an airfoil design problem, which is a single objective problem. The results are compared with the original EGO in terms of the convergence of the objective function and the diversity of the design variables. According to these problems, the proposed method acquires optimum solutions as effectively as the original EGO, while the diversity of the solutions is improved. In addition, the total design time can be reduced compared with the original EGO in a parallel computational environment.

Dehydrative coupling between indoles and isatins provides indolylindolinones as novel dyes with wide-range absorption due to intramolecular charge-transfer interactions.

The advantage in the thrust performance of the trielectode (TED) plasma actuator with serrated electrode edge was investigated. The trielectrode actuators have an additional exposed electrode, to which high DC voltage is applied, on the opposite edge of the buried electrode of the exposed AC electrode of SDBD plasma actuator. To prevent the uneven distributions of the discharge, the intentional dent that is evenly spaced on the exposed electrode was introduced. In this research, the induced body force of the TED plasma actuator was investigated on quiescent air by measuring thrust of the induced jet. A timeresolved PIV was used to acquire a velocity field in the quiescent air to measure the induced jet structure. To clarify the performance improvement mechanism, discharge plasma and flow field were numerically simulated. From the results of the thrust measurement, it is confirmed that the serrated TED plasma actuator enhances the thrust compared to the straight-edge TED plasma actuator especially at high DC voltage regimes. The absolute thrust attained 82.7mN/m, which was about 2.1 times larger than the straight-edge TED actuator and 17.5 times larger than the standard SDBD plasma actuator at the same conditions. The power efficiency became twice of the straight-edge TED plasma actuator and more than six times better than the SDBD plasma actuator at the same time. The PIV analysis clearly show that the serrated TED plasma actuator generate a uniform pattern of facing jet from both of the electrode for the positive DC voltage case, because of the uniform generation of the plasma from the sawtooth vertexes. For the negative DC voltage case, the uniformity of the induced flow was not improved.

This paper deals with the three-dimensional attitude control of an underactuated satellite equipped with thrusters whose force directions are fixed to the satellite. First, the necessary number of thrusters for the satellite’s attitude control is discussed utilizing the Minkowski-Farkas theorem. Then, using the wzparameters for a satellite’s attitude expression, this paper proposes a nonholonomic attitude controller which is effective for any satellite regardless of its moment of inertia. Numerical simulation demonstrates the effectiveness of the proposed controller. Furthermore, the efficiency of the controller for different thruster positions is also discussed.

This paper proposes a feedback control technique for the in-plane motion of a satellite equipped with two thrusters, whose force directions are fixed to the satellite. Such systems have second-order nonholonomic constraints due to the fixed force directions, and moreover their thruster forces are restricted to be unilateral. To control the satellites' global position and orientation, this paper develops a tracking controller to a designed invariant manifold based on the Lyapunov's second method. The developed controller is effective to control the satellite's global motion, even when the model parameters include some range of errors. Simulation results are shown to demonstrate the effectiveness of the developed controller.

This study focuses on the aerodynamic performance of the supersonic biplane at the low-speed region. The performance was evaluated and discussed through Computational Fluid Dynamics (CFD) and Experimental Fluid Dynamics (EFD). The result of the CFD simulation was compared with the experimental result to validate the simulation and confirmed to be reliable. Therefore, the CFD results were employed to derive the aerodynamic performance coupled with the theoretical equations. In the wind tunnel experiment, the three-component force measurement was conducted to obtain lift, drag and pitching moment coefficients. The wake survey was conducted to measure the drag in detail. The results proved the low-speed aerodynamic performance of the supersonic biplane can be described by the classical ``general biplane theory'' reasonably well.

One of the most critical technical issues with regard to supersonic commercial transportation is the sonic boom that occurs during supersonic cruising flight, which causes impulsive noise on the ground. The “supersonic biplane theory” has been proposed to reduce the sonic boom. Shock wave interaction and cancellation between the wings of a supersonic biplane can be realized at a specific design Mach number, but does not work at off-design values. Here, the low-speed aerodynamic performance, as off-design performance, of a baseline supersonic biplane was investigated and discussed using experimental and computational fluid dynamics approaches. The thin airfoil stall characteristics of a supersonic biplane were shown to be caused by the stall of both upper and lower wings at an angle of attack of 20°. Although there was leading flow separation of the upper wing at lower angles of attack, the stall of the lower wing was suppressed by interference with the upper wing. The lift of the lower wing was almost dominant to produce the lift of the supersonic biplane in the low-speed range. However, the lower wing caused greater drag than the upper wing at higher angles of attack.

Tri-electrode plasma actuator (TED-PA), which has a third electrode with high DC voltage, can generate stronger jet than that of conventional two-electrode type plasma actuator. However, the behavior of the jet in TED-PA is unexpected; the induced jet is deflected upward. To clarify the jet deflection mechanism and performance improvement mechanism of TED-PA, discharge plasma and flow field is numerically simulated based on the three-fluid plasma model and the incompressible Navier-Stokes equations with the body force term, respectively. The results show the jet deflection appears in both cases of negative and positive DC voltage; a rightward jet from the AC electrode and a leftward jet from the DC electrode are generated and the collision of the two jets generate the upward jet. The jet becomes stronger by the DC electrode due to two factors; the negative body force generation around the DC electrode and the positive body force enhancement around the AC electrode. The negative force generation around the DC electrode results from the drift motion of the positive ions in the positive DC voltage case, and on the other hand, that of the negative ions in the negative DC voltage case. The positive force enhancement around the AC electrode is due to the electric field intensification by the DC voltage.

The prognosis of stage IV malignant rhabdoid tumor of the kidney (MRTK) has been extremely poor. However, a combination of ICE (ifosfamide, carboplatin, and etoposide) and VDCy (vincristine, doxorubicin, and cyclophosphamide) was recently reported to be effective for metastatic MRTK. We describe a 21-month-old girl with stage IV MRTK who was successfully treated with ICE, VDCy, and radiotherapy. She remained well, without recurrence, 24 months after diagnosis. Alternating therapy with ICE and VDCy might become a standard regimen for stage IV MRTK, although further study is required to confirm its effectiveness.

This paper deals with attitude control of planar space robots, whose conservation of the angular momentum leads to a non-integrable constraint (: nonholonomic constraint) . Although most of previous works on feedback control for nonholonomic systems are developed for Chained (or Power) form, the space robot has singular configuration in transformation to the chained system. This paper seeks possibility of feedback control using manifolds, instead of an invariant manifold usually constructed through numerical integration for non-chained systems. The relation between the type of the manifold and behavior of the state variables are investigated in detail, and some conditions of the manifold are specified. Also, behavior of the state variables of space robots is verified numerically.

Background. Non-heart-beating donors (NHBDs) are not yet acceptable in orthotopic liver transplantation (OLTX) because of the high frequency of primary graft nonfunction. In this study, we aimed to develop a new predictive method of graft viability in OLTX from NHBDs. Materials and methods. (1) Pigs were subjected to 15 min of hepatic ischemia and reperfusion (I/R). (2) Porcine OLTX was performed using grafts obtained from NHBDs subjected to in situ warm ischemia (0, 30, and 60 min). During both operations, hepatic hypoxanthine levels were measured by a microdialysis method. Results. In the I/R model, hypoxanthine accumulated during ischemia and decreased after reperfusion, whereas marked xanthine and uric acid production were observed after reperfusion. In the NHBDs model, all of the 0-min group, 6 of 13 pigs in the 30-min group, and 1 of 6 pigs in the 60-min group survived more than 7 days. Significant increases of hypoxanthine levels were seen dependent on warm ischemic time. In the 30-min group, hypoxanthine levels were significantly higher in the pigs that died than in those that survived, and correlated with aspartate aminotransferase, lactate dehydrogenase, and adenosine triphosphate levels of recipients. Histological examination revealed that graft injury was severe in the pigs with higher hypoxanthine levels. Conclusions. It is suggested that hepatic microdialysate hypoxanthine levels during warm ischemia in NHBDs were correlated with graft viability in the recipient. By using of this technique, prediction of the graft viability may be possible during donor operation.

Background. Recently, a novel inhibitor of inducible nitric oxide synthase, ONO-1714, was developed. We evaluated the effect of ONO-1714 on a critical warm I/R model of the pig liver. Methods. Pigs were subjected to 180 min of hepatic warm I/R under the extracorporeal circulation. We investigated the time course of changes in the serum NO2− + NO3− (NOx), the cellular distribution of endothelial and inducible nitric oxide synthase, thrombocyte-thrombi, and nitrotyrosine by immunohistochemistry. The hepatic tissue blood flow (HTBF) was measured continuously using a laser-Doppler blood flowmeter. Results. ONO-1714 at 0.05 mg/kg improved the survival rate from 54 (control group) to 100%. The serum NOx levels in the ONO-1714 group were significantly lower than those in the control group at 1, 1.5, 2, 3, and 6 hr after reperfusion. The serum aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) levels of the ONO-1714 group were significantly lower than the control group, and the HTBF of the ONO-1714 group was significantly higher than the control group. The formation of thrombocyte-thrombi and nitrotyrosine after reperfusion was significantly lower in the ONO-1714 group. Conclusions. These results indicated that ONO-1714 improved the survival rates and attenuated I/R injury in a critical hepatic warm I/R model of the pig. ONO-1714 will be beneficial for hepatectomy or liver transplantation in the clinical field.

The flow control performance of the pulse-actuated plasma actuator and their mechanism was investigated. To clarify the flow mechanism of the separation control on a circular cylinder when pulsed plasma actuator is applied, the characteristics of the induced jet and their influence on the separated flow were separately examined. The characteristics of the induced jet from the pulsed plasma actuator were examined from the results of jet thrust measurement and high-speed Schlieren flow visualization. The effect of the frequency of pulsed plasma actuator on the flow separation on a circular cylinder model is examined in the viewpoint if aerodynamic force and the flow field measured with time-resolved PIV at the low speed wind tunnel test. For the induced jet analysis, the strength of the induced jet is found to be widely varied with the modulation frequency. When the modulation frequency is high, over 250Hz, the thrust of the induced jet increases with the modulation frequency increased. For the separation control test, the drag is significantly dropped with increasing the modulation frequency. From these results, it turns out that the enhancement of the induced jet generated from plasma actuator in high modulation frequency regime is the main cause of the enhancement of drag reduction performance.

An interferon-gamma (IFN-gamma)-inducing molecule (OK-PSA) has been purified from OK-432 by an affinity chromatographic technique performed on cyanogen bromide-activated Sepharose 4B-bound TS-2 monoclonal antibody, which neutralizes IFN-gamma-inducing activity of OK-432. OK-PSA has striking anti-tumor activity in vivo and in vitro. In the current study, the liposomes were used to improve the delivery of the agent (OK-PSA) to effector cells and to increase the therapeutic effect. Significantly less OK-PSA encapsulated into liposomes (Lipo-OK-PSA) than OK-PSA alone (1/100 or less of OK-PSA alone) was required to induce IFN-gamma, tumor necrosis factor-alpha (TNF-alpha), TNF-beta, interleukin-1 beta (IL-1 beta), natural killer, and lymphokine-activated killer activities by human peripheral blood mononuclear cells and mouse spleen cells. Furthermore, higher levels of these activities were detected in peripheral blood mononuclear cells and mouse spleen cells treated with Lipo-OK-PSA than in those treated with OK-PSA. All of these activities induced by Lipo-OK-PSA were almost completely neutralized by anti-asialo-GM1 antibody and complement (p < 0.001). In in vivo experiments, Lipo-OK-PSA elicited striking anti-tumor activity on syngeneic Meth-A tumor-bearing and colon 26-bearing BALB/c mice and on salivary gland tumor-bearing nude mice far better than did OK-PSA. Furthermore, high levels of natural killer and lymphokine-activated killer activities and a significant increase in the number of cells positive for asialo-GM1, IFN-gamma, TNF-alpha, or IL-1 beta were detected in the spleen cells derived from the animals given Lipo-OK-PSA compared with those given saline. These findings clearly indicate that OK-PSA plays an important role in the anti-tumor efficiency of OK-432, and that, for the most part, liposome encapsulation of this molecule markedly accelerates its effect mediated by asialo-GM1-positive cells (mainly natural killer cells).

血管吻合をより短時間で容易に施行できる器械吻合器VCSクリップを豚肝移植における肝動脈吻合において使用し, その有用性を検討した. 体重21～29kgの豚18頭に同所性肝移植を施行した. 肝動脈吻合はレシピエントとドナーの総肝動脈 (直径約3mm) の端端吻合で, 4点に支持糸をかけてその間をVCSクリップSサイズを約3～4針ずつ合計12～16針かけることで行った. 肝動脈吻合は顕微鏡を使用せず可能で, 吻合に要した時間は全例で20分以内であった. 術後3日目以上生存した豚は18頭中14頭 (77.8%) で, その内で1頭 (7.1%) のみに術後10日目に肝動脈血栓が生じたが, 全体の動脈の開存率は92.9%で解剖所見においても狭窄などは認めなかった. 術後45, 90日まで長期生存させた豚においても成長に伴った問題点はなかった. VCSクリップは肝動脈吻合を容易にし, 吻合時間を短縮させたので, 臨床においても使用すべき有用な器材であると考えられた.

肝切除後の血中アポ蛋白Bを測定し, 術後肝機能の評価としての有用性を検討した. 1997年1月から1998年6月までの当科で施行された肝切除症例のうち, 術前・術後にアポ蛋白Bと総ビリルビン (T. Bil), albumin, ICG15分, lectin-cholesterol acyl transferase (LCAT), prealbuminの各値を測定し, その解析が可能と判断された32例を対象とした. 施行した術式の内訳は肝部分切除6例, 肝亜区域切除8例, 1区域切除4例, 2区域切除14例であった. 全症例が耐術し肝不全の発症はなかった. 術式間で術後アポ蛋白Bの推移に有意差はなかった. 術後7日目のアポ蛋白BとLCAT, prealbumin, T. Bilとはそれぞれ有意な相関を認め (r=0.847, r=0.665, r=-0.442), ICG15分およびalbuminとは有意な相関はなかった. 以上よりアポ蛋白Bは肝切除後の肝機能回復の有用な指標になると思われた.

An 81-year-old man was seen at the hospital because of abdominal distention and severe constipation. An elastic hard tumor was palpable by the digital examination and it was downward with an increase in abdominal muscular pressure. Barium enema showed an intussusception of the sigmoid colon and made it release successfully. Total colonoscopy showed two tumors (Ip, Is) in the rectum, two (type 2, Ip) in the sigmoid colon, one (Ip) in the descending colon, one (Is) in the transverse colon and two (Ip, Is) in the ascending colon. Three of them were diagnosed as adenocarcinoma in their biopsy specimen. We performed low anterior resections for them and local resection for the other tumors under colonoscopy during operation. Pathohistological examination revealed adenocarcinamas in four lesions, with different depth of invasion each other (m, sm. mp, and ss). Other lesions were tubular or tubulo-villous adenoma with cellular atypia ranging from moderate to prominent.It has recently been reported that the hereditary factor seems to be involved in the etiology of multiple colorectal cancer. It is important to interview the patient about their family history and several gene analysis would be required for the patient with risk factors. In the case of multiple colorectal cancers, it is sometimes difficult to decide the extent of colectomy; partial or total colectomy in the number of lesions. Intraoperative colonoscopy is convenient and supportive technique in determining more adequate partial colectomy in the patients with low number of lesions.