Tensile elongation measurement device with in-plane bimorph actuation mechanism

This paper describes the development of a bimorph-actuated twin-probe device utilized for uniaxial tensile test to measure tensile elongation of a film specimen. The device consists of two sets of microscale cantilever probes with piezoresistive sensor to detect the position of two gauge marks on a specimen, and multiple pairs of bimorph actuators to produce in-plane motion for scanning those marks. By Joule's heating, the bimorph actuators connecting two cantilever probes are able to move along the tensile direction. When those probes climb the gauge marks having convex line structure, the sensor signals originating from the piezoresistive effect are output by the cantilever's deflection. The elongation of a tensile specimen can be calculated from the moving velocity of cantilever probes and the time difference between two sensor signals. The performance of the device produced through conventional micromachining technologies was investigated. Elongation of single-crystal silicon (SCS) film specimen was measured during uniaxial tensile loading. The mean Young's modulus of 165.1 GPa which was measured by using the device was in good agreement with the analytical value. The proposed bimorph-actuated twin-probe device would be useful for measuring elongation of a film specimen during the tensile test.     

iTRAQ-Based Proteomic Analysis of APP Transgenic Mouse Urine Exosomes

Alzheimer’s disease (AD) is a common dementia disease in the elderly. To get a better understanding of the pathophysiology, we performed a proteomic analysis of the urine exosomes (U-exo) in AD model mice (J20). The polymer precipitation method was used to isolate U-exo from the urine of 3-month-old J20 and wild-type (WT) mice. Neuron-derived exosome (N-exo) was isolated from U-exo by immunoprecipitation. iTRAQ-based MALDI TOF MS/MS was used for proteomic analysis. The results showed that compared to WT, the levels of 61 and 92 proteins were increased in the J20 U-exo and N-exo, respectively. Gene ontology enrichment analysis demonstrated that the sphingolipid catabolic process, ceramide catabolic process, membrane lipid catabolic process, Aβ clearance, and Aβ metabolic process were highly enriched in U-exo and N-exo. Among these, Asah1 was shown to be the key protein in lipid metabolism, and clusterin, ApoE, neprilysin, and ACE were related to Aβ metabolism and clearance. Furthermore, protein–protein interaction analysis identified four protein complexes where clusterin and ApoE participated as partner proteins. Thus, J20 U-exo and N-exo contain proteins related to lipid- and Aβ-metabolism in the early stages of AD, providing a new insight into the underlying pathological mechanism of early AD.     

Coal gasification using a molten iron bath

A coal gasification process using a molten iron bath as reactor has been developed by Sumitomo Metals. Pulverized coal is blown onto this molten iron together with oxygen and steam as gasification agents. Tests using a pilot plant having a capacity of 60 t (coal) day^?1, has shown that a sulphur-free carbon monoxide and hydrogen-rich gas can be generated at high coal conversion efficiency.     

Development of weatherproof mobile impulse voltage generator and its application to experiments on nonlinearity of grounding resistance

This paper describes a newly developed impulse voltage generator (IG). It has the following features: (1) The IG consists of three components (a 1.6 MV unit, a 1.4-MV unit and a base box); this facilitates mounting on 10-ton trucks, therefore making it easier to move to a test field. (2) Capacitors, discharge gaps and a control unit are enclosed in fiber-reinforced plastics, making it possible to use the IG in all weather. (3) The IG can generate several ten kA when a load is a few ten Ω. (4) Composition of the circuits for lightning/switching impulse voltage/current tests can be easily done by changing the damping and discharge resistance cassettes. Control and data acquisition are made by personal computer. For IG application during an outdoor test, this paper presents the characteristics of resistances of a 77-kV substation grounding and a concrete pole when applying a high impulse current. The resistances are dependent on the crest value of the applied current.     

Behavior of nitrogen and phosphorus during batch aerobic digestion of waste activated sludge—continuous aeration and intermittent aeration by control of DO

The purpose of this study is to find the behavior of nitrogen and phosphorus during aerobic digestion. Waste activated sludge samples from a municipal wastewater treatment plant were digested under 30 days batch operation, aerating continuously and intermittently. If the cycle time of intermittent aeration was decided so that the DO in a digestion tank did not become zero, the reduction rate of sludge solids and the behavior of nitrogen and phosphorus in the intermittent aeration were similar to those in the continuous aeration. The percentage of biomass nitrogen (phosphorus) in the initial total nitrogen (phosphorus) decreased and finally became 20% (30%). Forty per cent of the initial MLSS remained finally. On the other hand, the percentage of liquid phase nitrogen (phosphorus) increased during digestion and reached 60% (70%). It is considered that considerable portion of the initial total nitrogen (phosphorus) remains in liquid phase after aerobic digestion under sufficient supply of oxygen. Contents of nitrogen and phosphorus in residual biomass increased a little and decreased thereafter. Also, contents of them in reduced biomass increased monotonously.     

Changes in liver fatty acid unsaturation after partial hepatectomy in the rat

The purpose of this study was to assess changes in the degree of fatty acid unsaturation in rat liver after partial hepatectomy. This is the first study in which liver fatty acid unsaturation has been analyzed over a long period of regeneration until day 28 after operation. The relationship between changes in unsaturation and fatty acid composition in the regenerating liver were also investigated in this study. Proton nuclear magnetic resonance spectroscopy revealed significantly elevated levels of unsaturation with a maximum on day 5 after partial hepatectomy, compared with untreated controls (11.72±0.55 vs. 11.05±0.26%, P<0.05). No significant changes in unsaturation were found in day 1 regenerating liver, which is rich in absolute amounts of fatty acids. Based on gas-liquid chromatography, the relative amounts of oleic acid (18∶1n−9) and linoleic acid (LA; 18∶2n−6) were increased, while polyunsaturated fatty acids such as arachidonic acid (20∶4n−6) and docosahexaenoic acid (DHA; 22∶6n−3) were decreased on day 1. On the other hand, on day 5 of regeneration, while most fatty acids were returning to their preoperative control levels, only DHA was higher than the control value (7.69±0.58 vs. 5.57±0.37%, P<0.001). The high levels of unsaturation on day 5 were found to be partly due to the increase in DHA. The findings suggest that some significant signals are transmitted during the regeneration process owing to alterations in the membrane structure by the high levels of fatty acid unsaturation and the increase in DHA levels on day 5 after partial hepatectomy.     

Transient response of new type of varactor diode having multilayer structure

The transient response of a new type of varactor diode consisting of a semiconductor multilayer structure has been calculated by 2-dimensional time-dependent computer simulation. The simulated results show that the transient time of such a diode is somewhat larger than that of the conventional one with the same material parameters and diode dimensions.     

Ultimate strain of stiffened steel box sections under bending moment and axial force fluctuations

The influence of axial force fluctuations on the ductility of short steel cylinders has been previously reported by the authors, together with a proposal for a design formula that takes this influence into account. The present paper describes a similar investigation for stiffened short steel box columns. Elastoplastic large-displacement analysis of parametric short steel box columns is carried out and the bending behavior under constant and fluctuating axial forces is compared. The maximum value of axial force fluctuation is taken to be the same as the axial force magnitude in the constant axial force case. It is found that ductile capacity corresponding to the post-peak region of the bending behavior is improved to different degrees depending on the magnitude and amount of fluctuation of the axial force, a finding that is similar to that for short steel cylinders. Design formulae for failure strain taking this improvement into account are proposed for two different limit states and their validity is demonstrated through numerical analysis.     

Application of genetic algorithm to optimization of buckling restrained braces for seismic upgrading of existing structures

A systematic methodology is proposed for determining the optimal cross-sectional areas of buckling restrained braces used for the seismic upgrading of structures against severe earthquakes. Single-objective and multi-objective optimization problems are formulated. The objective for the former is cost and those for the latter are cost and damage. The constraint is the minimum structural performance required. A genetic algorithm is employed to solve both types of problem. Performance is estimated by conducting nonlinear dynamic analysis. A preliminary procedure based on static analysis is adopted to improve the search efficiency. Both approaches are applied to the strengthening of a multi-storey frame.