Detection of total assist and sucking points based on pulsatility of a continuous flow artificial heart: in vitro evaluation

We investigated the basic characteristics of the pulsatility of motor current with an in vitro mock circuit that consists of a sac-type pulsatile pump (simulating the natural left ventricle), three reservoirs, and our mixed flow pump (MFP). There are three alternatives at the inlet of the MFP: 1) the left atrium (LA), 2) the left ventricle (LV), and 3) both (LALV). The motor current waveform was monitored. The pump speed of the MFP was changed from 0 to 7,000 rpm. We calculated the index of motor current amplitude (ICA), which was obtained from the amplitude of the motor current waveform divided by the simultaneous mean value. The ICA plotted against the pump speed had a peak point (t-point) that highly corresponded with the turning point from partial to total left heart assistance. The ICA also had a second specific point (s-point) that corresponded with the beginning of severe sucking. In LV and LALV aortic bypass, t- and s-points could clearly be detected. In LA aortic bypass, however, early and severe sucking occurred, and t- and s-points were not manifest. These data suggest that the assist status of continuous flow artificial heart can be estimated by detecting the t- and s-points.     

Fabricating microgrooves with varied cross-sections by electrodischarge machining

A two-step electrodischarge machining method was proposed for fabricating microgrooves with varied cross-sections on hard materials. Firstly, tungsten tool electrodes were shaped by wire electrodischarge grinding, and then the resulting tool electrodes were used to electrodischarge machine microgrooves on stainless steel. Preliminary experimental results showed that, in the first step, a sharp tool electrode with surface roughness of 0.3 µmRa could be achieved, and the surface roughness of the resulting groove was 0.16 µmRa in the second step. Voltage strongly affects the machining speed. A high voltage (>70 V) was preferable for improving the material removal rate. However, significant tool wear took place when using a high condenser capacitance at high voltages. To suppress tool wear, a high voltage and a small capacitance should be used. As test pieces, microgrooves having rectangular, triangular, circular and semi-closed cross-sections were fabricated.     

Identification of a novel nuclear localization signal in Sam68

Landmarks in the development of treatment of retinal detachment include the recognition of the significance of retinal breaks that resulted in the distinction between rhegmatogenous retinal detachment (RRD) and exudative retinal detachment, the development of indirect ophthalmoscopy and scleral depression that allow better visualization of the peripheral area of the retina and better identification of retinal breaks, the recognition of the need to seal all retinal breaks, and the realization that vitreous traction is the major underlying cause of retinal tears and RRD. Scleral buckling procedures combine retinopexy to provide a scar around retinal breaks to seal them and scleral indentation to neutralize vitreous traction; they provided the first effective treatment of RRD. As surgeons gained experience with scleral buckling, they became aware that some RRDs, particularly those with fixed folds and/or a funnel configuration, often could not be repaired using this approach. It was thought that excessive vitreous traction was at fault, and the condition was called "massive vitreous retraction."     

Inverse Solidification Induced by Active Janus Particles

Crystals melt when thermal excitations or the concentration of defects in the lattice is sufficiently high. Upon melting, the crystalline long‐range order vanishes, turning the solid to a fluid. In contrast to this classical scenario of solid melting, here a counter‐intuitive behavior of the occurrence of crystalline long‐range order in an initially disordered matrix is demonstrated. This unusual solidification is demonstrated in a system of passive colloidal particles accommodating chemically active defects—photocatalytic Janus particles. The observed crystallization occurs when the amount of active‐defect‐induced fluctuations (which is the measure of the effective temperature) reaches critical value. The driving mechanism behind this unusual behavior is purely internal and resembles a blast‐induced solidification. Here, the role of “internal micro‐blasts” is played by the photochemical activity of defects residing in the colloidal matrix. The defect‐induced solidification occurs under non‐equilibrium conditions: the resulting solid exists as long as a constant supply of energy in the form of ion flow is provided by the catalytic photochemical reaction at the surface of active Janus particle defects. The findings could be useful for the understanding of the phase transitions of matter under extreme conditions far from thermodynamic equilibrium.     

Leaching behavior of heat-treated waste ash

The leaching behavior of heat-treated waste ash was studied to verify the possibility of the thermal treatment of waste incineration ash in existing incinerators and boiler combustion chambers. The influence of temperature, oxygen concentration and treatment time on the leaching behaviors of harmful heavy metals, especially lead (Pb) and chromium(VI) (Cr (VI)) were studied to clarify effective treatment conditions to suppress leaching. By examining the leaching behavior of Pb and Cr from ash heat-treated under various conditions, it was found that leaching can be suppressed by heat-treating the ash under conventional combustion conditions of around 900-1000 °C at 5-10% oxygen concentration. The leaching behaviors of Pb and Cr (VI) from real ash with different particle sizes and from model samples were also investigated in detail to find an effective method to suppress Pb leaching. It was found that the formation and growth of gehlenite (SiO₂·2CaO·Al₂O₃) in the ashes led to the decrease in the amount of Pb leaching. Therefore it was considered that the addition of an inorganic matrix with a high silica content that can promote gehlenite growth in the ash, for example, coal ash or waste glass is effective to suppress of Pb leaching.     

Mineralization of bisphenol A (BPA) by anodic oxidation with boron-doped diamond (BDD) electrode

Anodic oxidation of bisphenol A (BPA), a representative endocrine disrupting chemical, was carried out using boron-doped diamond (BDD) electrode at galvanostatic mode. The electro-oxidation behavior of BPA at BDD electrode was investigated by means of cyclic voltammetric technique. The extent of degradation and mineralization of BPA were monitored by HPLC and total organic carbon (TOC) value, respectively. The results obtained, indicate that the BPA removal at BDD depends on the applied current density (Iappl), initial concentration of BPA, pH of electrolyte and supporting medium. Galvanostatic electrolysis at BDD anode cause concomitant generation of hydroxyl radical that leads to the BPA destruction. The kinetics for the BPA degradation follows a pseudo-first order reaction with a higher rate constant 12.8x10(-5) s(-1) for higher Iappl value 35.7 mA cm(-2), indicating that the oxidation reaction is limited by Iappl control. Complete mineralization of BPA was achieved regardless of the variables and accordingly the mineralization current efficiency was calculated from the TOC removal measurements. Considering global oxidation process, the effect of supporting electrolytes has been discussed in terms of the electro generated inorganic oxidants. The better performance of BDD anode was proved on a comparative study with Pt and glassy carbon under similar experimental conditions. A possible reaction mechanism for BPA degradation involving three main aromatic intermediates, identified by GC-MS analysis, was proposed.     

Evolvable Reasoning Hardware: Its Prototyping and Performance Evaluation

In this paper, we propose evolvable reasoning hardware and its design methodology. In the proposed design methodology, case databases of each reasoning task are transformed into truth tables, which are evolved to extract rules behind the past cases through a genetic algorithm. Circuits for the evolvable reasoning hardware are synthesized from the evolved truth-tables. Parallelism in each task can be embedded directly in the circuits through the direct hardware implementation of the case databases. We developed the evolvable reasoning hardware prototype using Xilinx Virtex FPGA chips and applied it to the English-pronunciation-reasoning (EPR) task. The evolvable reasoning hardware for the EPR task was implemented with 270K gates, achieving an extremely high reasoning speed of less than 300 ns/phoneme. It also achieved a reasoning accuracy of 82.1% which is almost the same accuracy as NETTalk in neural networks and MBRTalk in parallel AI.     

TEM analysis of high temperature annealed W nanostructure surfaces

Helium plasma irradiation and electron heating experiments were conducted using tungsten in the divertor simulator NAGDIS-II. Helium plasma irradiation to tungsten led to the formation of nanostructures on the surface, while the nanostructures were annihilated after the potential of the specimen was changed to positive for several 10 min so that electrons irradiated the sample without ion irradiation. The specimens were analyzed in detail by transmission electron microscope with the help of focused ion beam technique. It is revealed that the helium nano-bubbles still remained even after the nanostructures were disappeared from the surface. Porosity of the nanostructured tungsten was measured from the TEM images.     

Preparation and properties of biocomposites composed of sorbitol‐based epoxy resin,pyrogallol–vanillin calixarene,and wood flour

The reaction of pyrogallol (PG) and vanillin (VN), both of which are derived from plant resources, in the presence of p‐toluenesulfonic acid gave PG–VN calixarene (PGVNC) mainly composed of guaiacyl pyrogallol[4]arene. After sorbitol polyglycidyl ether (SPE) was mixed with PGVNC in tetrahydrofuran at an optimized epoxy/hydroxy ratio 1/2.65, the obtained SPE/PGVNC solution was mixed with wood flour (WF), prepolymerized at 150°C, and subsequently compressed at 190°C for 3 h to give SPE–PGVNC/WF biocomposites with WF content 0–20 wt%. The tan δ peak temperature of SPE–PGVNC was 148.1°C, which was much higher than that of the SPE cured with petroleum‐based phenol novolac (SPE–PN) at an optimized epoxy/hydroxy ratio 1/1. Although tan δ peak temperature slightly decreased with increasing WF content, the storage moduli of the SPE–PGVNC/WF biocomposites in the rubbery state at more than 150°C were much higher than those of SPE–PGVNC and SPE–PN. Also, the tensile modulus and strength for SPE–PGVNC/WF increased with increasing WF content. Field emission‐scanning electron microscopy analysis of the biocomposites revealed that WF is tightly incorporated into the crosslinked epoxy resins. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers