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Continuous wet granulation using a twin-screw granulator has attracted much interest in the pharmaceutical industry. The physical properties of granules prepared through the twin-screw granulation process depend on the several factors, such as screw and barrel geometries, operating conditions, and formulations of raw materials. In particular, it is known that the fill level in a twin-screw granulator and the binder additive ratio have an impact on the twin-screw granulation process. In this study, mutual effects of the two major factors on the granulation process was investigated experimentally and numerically. By combining the experimental and numerical analyses, a prediction model of the granule growth rate was proposed. The proposed model demonstrated that the granule growth rate was determined by the total energies (compressive and shear directions) and the index of granulation. [ABSTRACT FROM AUTHOR]

The microstructure changes in the precipitation hardening copper alloys during the thermal process after deformation are known to exhibit complex behavior due to the simultaneous progress of various phenomena such as precipitation, recovery, recrystallization, and grain growth. Understanding the mechanism is an important issue for designing the heat treatment processes. In this study, the microstructure changes in the Cu–Co–P alloy during thermal process after a deformation was numerically simulated based on the N model coupled with the dislocation recovery model, where the interaction between dislocations and precipitation behavior was focused. As a result, the following peculiar phenomena were calculated: The fcc–Co formation and the Co2P precipitation on dislocations take place simultaneously in the Cu–0.32 at％Co–0.21 at％P–0.11 at％Sn alloy. The Co particles are left inside the bulk Cu matrix in the recovery process of dislocations, and then the Co particles are re–dissolved into matrix phase. The following mechanism was proposed to explain this peculiar behavior. Since the Co particles in the bulk matrix left by the dislocation recovery have high interfacial energy, they redissolve into the matrix phase to release this energy. Furthermore, the decrease in Co concentration in the matrix phase due to the Co2P precipitation on the dislocation accelerates the Co particle re–dissolution. [ABSTRACT FROM AUTHOR]

In this study, transient analysis of flexible body motion with time-varying length is conducted using dimensionless finite element model (FEM). First, the equation of motion for a flexible body with large deformation, displacement and time-varying length is derived by VFE-ANCF, which variable-domain finite element model (VFE), a model expresses length change, applied to absolute nodal coordinate formulation (ANCF), known as an effective nonlinear finite element method in dynamic flexible body simulation. Then the equation of motion in dimensionless form is derived using dimensionless variables defined by time-varying length of the flexible body as a representative length and a representative time considering the longitudinal frequency of the flexible body. The system is converted into the system that length of flexible body is always constant by using this representative length. So, this method avoids the problems with analysis accuracy and calculation cost when the length becomes shorter and the natural frequency increases. Furthermore, the numerical results clarify the mechanism of flexible body motion with time-varying length.

Faceted macrostep formed at equilibrium is demonstrated based on numerical calculations using the tensor network method and the Monte Carlo method. The adopted model is a lattice model where the surface roughness excitations and the step-step attractive energy (Snt) are taken into consideration. We calculated Snt-T and p-T faceting diagrams for faceted macrosteps where T is the temperature, and p is the surface slope for an inclined surface. Applying the faceting diagrams to Si(113)+(114) surfaces, the step-step attractive energy is approximately 123 meV. We also discuss elementary step attachment/detachment processes to/from the faceted macrostep near equilibrium. [ABSTRACT FROM AUTHOR]

High efficiency coal fired power plants are expected to operate at a certain rate due to low generated electricity costs. In coal fired power plants, coal mills are important machinery that pulverize the coal and supplies the coal powder to the boiler. To protect the bearings from coal dust, seal air is added. The seal air is supplied from one air compressor to each position of several coal mills at a target power station. An imbalance in its flowrate can lead to coal mill failures, thereby affecting the operation of coal fired power plants. In order to diagnose any problems with the operation of a coal mill immediately after maintenance, the heater method was used to measure the seal air at five locations from the outside of the supply pipes. The heater method is possible to measure the flow rate of compressed air and steam in the pipes from the outside of the pipes without any modification of the pipes, and has previously been applied to the measurement of cooling air flow in gas turbines. In the present case, three pipes out of five measuring points have curvature, so that a numerical analysis was carried out to verify whether the heater method is valid. Due to the effects of the corona disaster and other work, the measurement schedule at the power station was restricted and the installation, measurement and removal of instruments at five locations was carried out in a period of five days. As a result, it was confirmed that the seal air flowrate at each of the coal mill locations was normal value and that there were no problems with operation.

A system for recovery of methane hydrate from the deep ocean floor has not been established. As one possible recovery system, a gas-lift system was investigated. Experiments were performed with a gas-lift system of 5 m height and 100 mm in diameter to determine the relationship between injected gas quantity and pumped water quantity. Vertical flow in the gas-lift pipe was calculated with a compressible one-dimensional two-fluid model to analyze flow in the recovery pipe of methane hydrate from the deep ocean floor. Basic equations were mass conservation equations and momentum conservation equations of each phase, the relation of volume fractions and the state equation of the gas phase. The calculation showed that optimal gas injection depths exist. Thus, the gas-lift system can be economically effective the recovery of methane hydrate from the deep ocean floor. Abstract A system for recovery of methane hydrate from the deep ocean floor has not been established. As one possible recovery system, a gas-lift system was investigated. Experiments were performed with a gas-lift system of 5 m height and 100 mm in diameter to determine the relationship between injected gas quantity and pumped water quantity. Vertical flow in the gas-lift pipe was calculated with a compressible one-dimensional two-fluid model to analyze flow in the recovery pipe of methane hydrate from the deep ocean floor. Basic equations were mass conservation equations and momentum conservation equations of each phase, the relation of volume fractions and the state equation of the gas phase. The calculation showed that optimal gas injection depths exist. Thus, the gas-lift system can be economically effective the recovery of methane hydrate from the deep ocean floor. [ABSTRACT FROM AUTHOR]

Directional reflectance and transmittance against a bulk of the aluminum-doped zinc oxide (AZO) and scattering phase functions were evaluated to demonstrate the effectiveness of Blender, open-source software for the 3D computer graphics, as a generic method to conduct the raytracing simulation. In order to rigorously express the reflection, refraction, and transmission at the interface between vacuum and AZO, which has a complex refractive index, the behavior of the ray at the interface was modified, introducing shaders developed by several scripts written in the open shading language (OSL). Moreover, the relative intensity of reflected and transmitted rays were observed using a fisheye camera. The preset shaders in Blender could not express directional reflectance correctly for high incident angles; however, the directional reflectance using the shader from the OSL script superposed on the theoretical solution that is derived from Fresnel's equation. In addition, the shader from the script could express the absorption in a medium with an extinction coefficient; thus, the transmittance matched to the solution derived from Lambert-Beer's law. These scripts also exhibited correct results for the analysis of the film that shows multiple reflections. Moreover, the scattering phase functions defined by the script approximately corresponded to that of the isotropic and Rayleigh scattering. [ABSTRACT FROM AUTHOR]

Magnetic flux leakage testing to compensate for the visual inspection in the inspection of the wire ropes has been studied. In recent years, it has become possible to improve the damage detection accuracy by using a device which utilizes the hall effect and magnetoresistance effect due to the development of semiconductor technology. Detection of the small damage also became possible. However, since the noise of measurement data is contained much when inspecting the wire ropes, it is difficult to detect a very small damage. Cause of noise depends on the configuration of the eccentric and the strands and the strands of the rope. Eccentricity of the rope has been demonstrated in previous studies to contribute to the noise. However, the noise due to strands and strands of the ropes is an evaluation of only the magnitude of the magnetic flux density. Thus, discussion of the direction of the magnetic flux is not performed. In this paper, the effect of noise caused by the strand is evaluated by experiment and numerical analysis. Furthermore, we verified whether useful in reducing noise due to strands of the rope by the sensor's angle. Therefore, it was found that there is due to strands of the rope as cause of noise. It showed that it is possible to noise reduction by matching the detected angle of the sensor with twist angle of the strand.

Origami structures with curved creases (curved origami structures) have gained extensive attention in several fields. It is well-known that self-locking is one of characteristics of the curved origami structure. When the self-locking occurs, its shape is fixed without external forces. On the view of computer-aided design for the curved origami structure, many studies have focused on computational modeling methods of its shape. However, there are few methods to evaluate mechanical characteristics of the curved origami structures and to simulating folding behavior from unfolded state to folded state with occurring self-locking. Therefore, this study proposes a new computational modeling method for the curved origami structure. In the proposed method, truss elements are applied to creases modeling in finite element analysis and the self-locking is simulated using stepwise forced displacements. To clarify availability of the proposed method, design and simulation problems of origami grippers which are curved origami structures with occurring self-locking are investigated. Through this investigation, feasibility of origami grippers is also discussed.

On-chip microdroplet-based electroporation is a newly developed process that enables droplet electroporation in a microfluidic device. If the process is to be realized at low cost, the electrode pair should be installed on the same plane. On the other hand, the electrode pair is installed as parallel plates in electroporation process with ordinary cuvettes. When the electroporation process is converted to a microfluidic device, the effect of electrode placement must be investigated because the electrode placement pattern is different from that of conventional electroporation. Therefore, numerical analysis of cell membrane perforation in micro rectangular channels was performed to support the design of an on-chip microdroplet-based electroporation system. The calculated geometry was given a state in which one cell was located in the center of the droplet. Since membrane perforation by a voltage pulse is a 1 μs time scale phenomenon, a numerical method was applied in which the electric field formation and membrane perforation are calculated in the same time step. The current conservation equation and the asymptotic Smoluchowski equation were coupled by the transmembrane voltage to calculate the time dependence. The calculation results showed that the position of high pore density on the cell membrane was slightly shifted compared to the case of electroporation by cuvette, but the position was almost ideal. And the pore density, electric field strength and transmembrane voltage distribution on the membrane showed accurate perforation locations and mechanisms. In addition, numerical analysis was also performed on the ideal parallel plane electrode assuming electroporation with a cuvette. It was shown that although the parallel planar electrode enables more efficient electroporation, the same planar electrode can also perforate the cell membrane at almost the same position. Finally, based on the results of 81 different calculations, the transitions in pore density and transmembrane voltage when cell is translocated are shown. The computing software COMSOL Multiphysics 5.4 on Windows OS was used on the workstation HP Z8 (CPU: Intel Xeon Gold 6128×2, Main memory: 96 GB).

It is important to understand characteristics of rocking vibration related to overturning small structures inside buildings. In order to understand the overturning of the structure due to rocking vibration by numerical analysis, numerical analysis considering energy loss in a collision and duration of collision is performed by using a quadrilateral hysteresis loop characteristics in which repulsive force is a function of speed. In case that the restitution coefficient is constant and sine wave is used as an input wave, it is good agreement between experiment and numerical analysis response waveforms of rocking vibration in stationary process. However, it is not good agreement in nonstationary process. And it is not good agreement between experiment and numerical analysis response waveforms of rocking vibration using seismic ground motion as an input wave. On the other hand, in case that the restitution coefficient is considering energy loss in a collision and duration of collision, sine wave is used as an input wave, it is good agreement between experiment and numerical analysis response waveforms of rocking vibration in nonstationary process. Also it is good agreement using seismic ground motion as an input wave. From these results, numerical analysis for rocking vibration considering energy loss in a collision and duration of collision is effective using a quadrilateral hysteresis loop characteristics in which repulsive force is a function of speed. And it is effective for this model to understand overturning behavior of small structures in earthquake.

In case pressurized water or vapor leaks from a failed heat transfer tube in a steam generator of a sodium-cooled fast reactor, a high-velocity, high-temperature, and corrosive jet with sodium-water chemical reaction may cause tube failure propagation. In this study, a numerical analysis method to predict the occurrence of tube failure propagation by overheating rupture was developed to expand an application range of an existing computer code. This method consists of the elemental analysis models for a sodium-side temperature distribution formed by a reacting jet, water-side thermal hydraulics, heat transfer of a tube, and tube failure by internal pressure. To evaluate event progress at a shortest computation time, the elemental analysis models of this code were constructed from the experimental data, semi-theoretical correlations, or one-dimensional equations. Applicability of the method was investigated through the computation of an experiment on water vapor discharging in liquid sodium. In this experiment, one tube for water vapor discharging and the 91 target tubes were placed in a liquid sodium pool. Temperature of the target tubes increased by the effect of the reacting jet in this computation. Some of the target tubes near the initial water leak resulted in overheating rupture as with the experimental result. This computation demonstrated that the proposed method could predict the occurrence of overheating rupture and provide conservative results.

In this paper, heat transfer characteristics and the pressure drop response of sandwich structures containing open-cell core were studied by using numerical simulation. The effect of micro-architecture and cell size of the unit cell on these characteristics were investigated by changing relative density of the models. In this paper, three types of open-cell were analyzed. There is a trade-off relationship between the heat transfer characteristics and the pressure drop response. These factors are the direction of thermal paths, surface area size and internal flow state. Also, these factors can be controlled without changing the relative density when the cell size is changed and the aspect ratio is equal. In order to clarify the characteristics of the open-cell, the open-cell were compared with two types of closed-cell as representative of other cores in terms of two dimensionless numbers (Nusselt number and friction factor). As a result, it was confirmed that the open-cell has high superiority in applications requiring light weight and high heat transfer characteristics.

Micro bubbles measuring tens of micrometers or less in diameter have recently been paid much attention. Swirl-type, pressurizing dissolution, and perforated plate methods have been proposed for micro bubble generation. The swirl-type method can generate micro bubbles even under low-pressure power in a simple structure. The enlarged inlet diameter of the swirl chamber can reduce the average bubble diameter. This study examined the effect of the swirl chamber inlet diameter on the flow around chamber outlet in a swirl-type micro bubble generator by numerical analysis. The Inlet diameter of the swirl chamber was changed to 30 mm, 60 mm, and 90 mm, the flow velocity distribution and the wall shear stress around the chamber outlet were calculated. As a result, when the inlet diameter of the swirl chamber was enlarged, it was clarified that the circumferential flow velocity and the wall shear stress around the chamber outlet increased, which reduced the average bubble diameter. [ABSTRACT FROM AUTHOR]

Hoeffding probability inequality has been known as the best theoretical way for evaluating the upper bound of upper probability about the average of some random variables based on limited stochastic properties such as the expectation, variance and codomain in each random variable. In this study, based on Hoeffding probability inequality, we address a numerical analysis procedure for improving the performance to evaluate the upper bound of upper probability about the average of some random variables. [ABSTRACT FROM AUTHOR]

In recent years, a system with rigid and extremely flexible components (hereinafter called “SREF”) are often employed for satellite systems in order to realize various vast structures in orbit, and flexible components are made of strings, membrane and so on. In general, flexible component of such a system has two states, one is the state with tensional force and the other is without tensional force. Therefore, state transition of the system arises depending on its configuration, and then careful treatments are required for the analysis of such a system, because number of the combination of state increases dramatically depending on the number of mass and flexible component. Eventually, such an increase of components results in the computational difficulty in the analysis of such a system. Authors have found analogy between the state transition of the SREF and contact problem described by linear complementary problem which was developed by Pfeiffer et al., thus similar procedure can be employed for the analysis of the motion of SREF. In this paper, considering such an analogy and introducing some assumptions, state transition problems for SREF are formulated as liner complementarity problem and effective analysis method for dynamic behavior for SREF is proposed. In order to show the validity of the proposed method, some numerical analyses are performed and physical interpretations of the obtained results are discussed. Furthermore, comparison of the numerical analysis between experimental results shows the validity and advantage of the proposed method.

In this study, we intended to predict bearing temperature of oil bath tilting bearings with high degrees of accuracy, and developed a more detailed formula estimating mixing temperature at the inlet of the oil film on the pad. In order to consider the complicated flow in terms of the fluid and heat between pads, we precisely solved the conservation laws of the flow and energy at the control volume adding effects of rise of temperature due to agitation loss and leak between the shaft and the seal, and we got the accurate temperature of the mixing inlet oil. Moreover, we measured the bearing temperature distributions under various conditions with a test bearing bored 280mm in diameter to validate the analysis. Eventually, we got the following conclusions. (1) Compared with the analysis using the conventional model, the proposed model can reduce the errors of the oil film temperature distribution by one third. (2) In terms of prediction of the mixing inlet temperature that affects degrees of precision of the oil film distribution, the proposed model can improve 2 oC of variability and 10 oC of average errors, compared with He's model, and it found the fact that the method can improve the accuracy of the calcuration of bearing temperature. (3) The proposed model can predict temperature at the evaluation point within -8.6~+5.4 oC.

In this study, vibration characteristics of a single-degree-of-freedom linear oscillator with the fractional order derivative are examined in terms of the critical damping over a wide range of the order of the fractional derivative by using numerical analysis. Two types of the definitions of the critical damping used in the previous studies are considered. It is shown that (i) the critical viscoelastic damping ratio changes according to the order of the fractional derivative and its minimum value for both types of the critical damping is less than 1; (ii) no critical viscoelastic damping ratio is observed in a certain range of the order; (iii) the difference in the existence of the critical damping between the oscillators with the derivative of order 1/3 and 2/3 is caused by the change of the behavior of a component of the response corresponding to one of the roots of the characteristic polynomial for the oscillator. Finally, the impulse response characteristics are classified into three classes depending on the order of the fractional derivative and viscoelastic damping ratio of the oscillator.

This paper presents an experimental and analytical investigation of the thermal characteristics in a layer of exothermic powder mixture that is utilized in body warmers, hot compresses, thermotherapy, etc. The research objective is to develop a manufacturing method that enables the exothermic temperature to be controlled in order to prevent cases of low-temperature burns. The exothermic powder mixture generally comprises metal powder, catalyst powder, and vermiculite particle absorbing some saline solution. The exothermic powder mixture is put into a mini-autoclave, and then placed in a constant temperature bath after the atmosphere inside the mini-autoclave has been replaced with pure oxygen. The degradation of oxygen pressure inside the mini-autoclave shows that the reaction rate of corrosion depends on the reaction temperature, the volume of the saline solution, and the conversion of iron powder into oxide, in addition to the ambient oxygen concentration; a correlation is suggested for the reaction rate. The variation over time of the temperature distribution in a layer of the exothermic powder mixture is evaluated analytically using this empirical correlation for the reaction rate, and compared with the experimental results. In the analysis, the mass, momentum, energy and oxygen component equations are solved numerically for a layer of the exothermic powder mixture, which is regarded as a porous medium. The analysis does not predict the temperature distribution accurately, but the analytical and experimental results are in accordance qualitatively.

Since the great east Japan earthquake in 2011, renewable energy is turned into importance. Hydro power is one of most important energies because it is not affected by weather condition and possible to generate steady quantity electric power, so it could be base load power. These days low head hydro power generation is going to increase, because it is easy to be set irrigation channel and agricultural waterway. We have developed water turbines appropriately for low head open channels to effectively utilize the hydro power energy. To improve the performance of the turbine, it is necessary to determine the free surface flow patterns around the turbine. We selected the undershot cross-flow water turbines which could apply to various sizes of channel and flow rate. Because we removed the turbine casing and guide vane, free surface flow patterns of the undershot cross-flow water turbine are very complex. We have researched free surface flow patterns around the turbines using both experiment and numerical analysis. We modified the apparatus system, and could measure mechanical friction loss of bearing. We introduced more precise computational grid of numerical analysis. So it was possible to specify more precise flow patterns near the runner. Time-averaged velocity distribution at inner or outer circumference of runner was almost consistent. As rotational speed increased, volume of cross-flow decreased and that of reversal flow increased. In generating torque and power of turbine, the most significant kind of flow was second stage cross-flow, and the most dominant component of flow was angular momentum. We estimated the torque and power of the turbine based on moment-of-momentum equation, and these results were consistent well with those of calculation.

Two driving systems in which a circuit breaker is driven synchronously and sequentially by two devices which are connected with relatively long hydraulic pipes were investigated. Numerical analysis method of pipe flow, which is modeled by lumped parameter system, was compared with theoretical solutions modeled by using distributed parameter system. It was confirmed that proper results could be obtained by the numerical method. Hydraulic transmission and operating time of two driving system were investigated by using the numerical method and measurement. Dimensions of the connecting pipe and other hydraulic constants influence the motion time of two devices. Particularly, the different length of connecting pipe at asymmetrical arrangement has much influence. The synchronous driving system suppresses the time difference of two operating devices by symmetrical arrangement and appropriate dimensions of connection pipe. The sequential driving system which uses dashpot pressure gives us stable delay time under the change of conditions and makes it possible to adjust the range of delay time by using hydraulic volume and restrictor.

The warp deformation behavior for various viscoelastic four-layer laminated structure consisting of epoxy resin, printed board and steel which modeled electronic devices caused by a series of thermal load from heating to cooling was examined by experiment and viscoelastic stress analysis based on linear viscoelastic theory. As a result, it was clarified that the warp deformation behavior of laminated structure containing resin was influenced by thickness and viscoelastic properties of epoxy resin and printed board such as modulus of longitudinal elasticity and thermal expansion coefficient depending on temperature and time, and that the warp deformation behavior of viscoelastic four-layer laminated structure was determined by the balance between flexural rigidity of laminated structure and bending moment caused with the thermal expansion or shrinkage of constituent materials. The warp deformation behavior of laminated structure containing resin could be predicted in general by analysis in consideration of the characteristic of viscoelasticity.

Armored fighting vehicles with Mine Resistant Ambush Protected (MRAP) designed to counter Improvised Explosive Devices (IEDs) have recently attracted special interest. This paper describes dynamic response of the shock absorption seat to blast load. Mathematical models have been developed to predict the effects of the blast load on the seat-passenger system. We propose a hook-spring mechanism which consists of two springs (a hook-spring and a cushion spring). The hook spring (stiffer spring) supports the seat and the human passenger under normal operation. When the seat and passenger receive the blast force, they lose contact with the spring. After that, the cushion spring (softer spring) supports them. The influence of the hook-spring mechanism seat on blast load is confirmed by numerical simulations and experiments.

Smoothed particle hydrodynamics (SPH) is a particle method for analyzing physical problems. But this method has numerical problems when treating multilayer problems and free surface. In this report we propose equations to treat multilayer heat conduction problems and normalized equations to avoid the edge effect which is caused by the lack of particles at the free surface. Numerical results, in the case of 1 layer heat conduction model has good agreement with results of difference method. Numerical results in the case of 2 layer heat conduction model, where the ratio of heat conductivity of 2 layer is changed from 5 to 50 shows that normalized equations are effective to treat multilayer heat conduction problems.

A railway collision at a level crossing of the Hakodate line of JR Hokkaido occurred on January 29, 2010. The details of this accident can be obtained in the railway accident investigation report published by the Japan Transport Safety Board. Based on this railway accident investigation report, numerical simulations of the level crossing collision were conducted in order to investigate a correlation between the injury rate of passengers and the deceleration history during collision. New modeling methodologies and initial conditions derived from accident details were adopted and also in order to obtain accuracy of numerical simulations, analysis models of the cab end structure and the interface structure between cars in the train were validated by quasi-static compression tests. Since the numerical simulation shows good correlation in the deformations of the cab structure and a situation of scattered parts of the railway obstacle, this paper finally demonstrates the deceleration history of each car body of the relevant train set in the level crossing collision. In regards to the maximum value of the integration of the deceleration history: MID, it was found that 7.4m/s occurs at the leading car, which had the most injuries, and it appears that exceeding 4m/s results in increase of rate of injuries above 50%. Regarding injury parameters, values at forward facing seats are lower than the half of the criteria of FMVSS208 but values at the seat of the fore end of the cabin exceed the criteria. It is estimated that injury parameters at the seat of the fore end of the cabin are within the criteria if MID is kept under 6m/s.

Failure mechanism of composite laminates with impact damage subjected to compression was studied using finite element analysis. The impact damage was modeled as a double-spiral-damage which consisted of fan-shaped delaminations and matrix cracks. Cohesive element was used to simulate the damage growth. First, the damage growth before the unstable propagation of the damage was discussed from the results of static implicit analysis. Next, the failure process of laminate was analyzed by a dynamic explicit analysis. The damage grew in the transverse direction to the compressive load due to the through-thickness local buckling of the damaged area. Unstable propagation of the damage accompanying large load drop occurred suddenly after the small stable growth of the damage. The transverse damage sizes of all delaminations tended to become in equal size.

This paper presents a numerical analysis of adhesion contact due to meniscus between a sphere and a flat considering the elastic deformation of the contacting surfaces. Analytical model and basic equations for numerical analysis are explained first. Meniscus contact characteristics are presented for a 2-mm-radius glass contact on a magnetic disk coated with submonolayer mobile lubricant, and 2-μm and 20-nm-radius asperity contacts on mobile and bonded lubricant layer with a low elasticity. It was found that the sphere-flat contact with submonolayer liquid meniscus shows Derjaguin-Muller-Toporov theory-like behavior to Johnson-Kendall-Roberts theory-like one as the mobile layer thickness decreases from 1 nm to 0.3 nm. There is a critical liquid film thickness below which the meniscus length becomes zero so that the meniscus liquid cannot be transferred to the mating surface. This numerical method can be used for the rigorous analysis of various meniscus adhesion contact problems. Some of the experimental adhesion characteristics between a glass sphere and a magnetic disk are discussed from the aspect of the calculated results of elastic meniscus contact.

This paper reports on the behavior of shock triple points on the detonation wave propagating in the rectangular tube, which is obtained from the experimental observation and numerical analysis. Used gas mixtures are the equimolar gas mixture of acetylene and oxygen in the experiment, and the stoichiometric hydrogen and oxygen in the numerical analysis. However, if there are the specific number of shock triple points in the tube, the numerical analysis using finite difference method which is composed of semi-implicit MacCormack TVD scheme can reproduce the propagation behavior obtained by experiment. Therefore, the propagation mode of detonation is identified by geometry of emission points and emission trajectories of the experimental observation. And then, the detailed propagation mechanism of its detonation which is difficult to observe in the experiment has been revealed.

We have theoretically investigated the properties of the stress wave propagation which is caused by a longitudinal impact of a cylindrical bar by a one-dimensional model. In the present study, the effects of the boundary condition and material nonlinearity of the bar are taken into account. An exponential function is chosen as the constitutive equation in order to realize that the one-dimensional model possesses some useful properties for the analysis. A governing equation which describes the behaviors of the stress wave is derived from the one-dimensional model. Since the governing equation is complicated, some mathematical techniques are applied in order to analyze the behaviors of the stress wave. As a result, it is shown that the stress wave, which can propagate through the cylindrical bar of semi-infinite length and that of finite length, is derived exactly from the governing equation. Moreover, the behaviors of the stress wave are shown analytically.

In this study, compactification (improvement of the light receiving density) and reduction of the directivity (dependence property for the sun position) are tried to improve the efficiency of the photovoltaics using Light Received Analysis Algorithm of a Plant Shoot (LAPS). The LAPS is a method of analysis to check the form of a plant shoot that has high light receiving density by numerical analysis using GA. A big scale plant needs big energy for maintenance and growth. A characteristic of the big scale plant is to have a branch structure. Thus, it means that a branch structure is necessary to get big energy by the solar cell module simulating a plant shoot. However, conventional LAPS was not able to express the branch structure so far. Therefore L-system is applied to LAPS. The purpose of this paper is to elucidate the influence that the branch structure gives to light receiving density. The analysis is carried out under sunshine condition of the summer solstice and the winter solstice in Sapporo, Hokkaido, and used a ginkgo for the shape of the leaf. As results, solar cell modules with the branch structure of a plant shoot optimized for sunshine condition of the summer solstice and the winter solstice were obtained. As the number of leaves increased, the solar cell module with the branch structure of a plant shoot came to have higher light receiving density than that of the solar cell module without the branch structure of a plant shoot. From this, it is confirmed that the branch structure increases the light receiving density of a plant with many leaves.

In recent years, various networks have come to exist in our surroundings. This not only includes examples such as the internet and airline routes that can be thought of as networks; protein interactions are also networks. A network is defined as an arrangement of nodes (points) and links (lines). An "economic network design problem" can be discussed by assuming that a vertex is an economic player and that a link represents some connection between economic players. An economic player can mean an individual, an association, a city, a nation and so forth. A connection between economic players signifies items such as a transport link, a telecommunication net or an economic regional alliance. In this paper, an "economic network design problem" is modeled based on Jackson and Wolinsky's connections model, and the utility function of the network is defined. In the field of economics, generally, the game theory approach is adopted for analysis of network formation. However, we encounter difficulties when a network has many heterogeneous nodes. Therefore, we suggest that the optimization of an "economic network design problem" can be solved using evolutionary computation. As an example of an "economic network design problem," we consider an optimization problem of a network between regions in West Japan. In addition, the priority of the network maintenance is clarified via the optimum network obtained in the simulation. [ABSTRACT FROM AUTHOR]

The constitutive relation of core concrete for concrete-filled CFRP-steel tubular columns is put forward based on modified constitutive relation of core concrete of concrete-filled steel tube, and a commercial ANSYS FE software is employed for the simulation of the relation of stress and strain of concrete-filled CFRP-steel tubular short columns with axial compression. An experimental investigation was performed on 12 specimens, including 8 concrete-filled CFRP-steel tubes and 4 concrete-filled steel tubes. Numerical analysis results curves are consistent with the test data, which proves that the provided constitutive relation of. concrete is fit for the concrete-filled CFRP-steel tubular short columns with axial compression. [ABSTRACT FROM AUTHOR]

Based on the premise of the first-order cumulated generating series with the character of exponential growth, the background value of grey model is improved by the predictor-correcting technique to enhance the prediction precision of grey model. The numerical experimental results show that the precision and adaptability of the grey model are improved effectively. Finally, energy demand is predicted up to 2015 using the improved model coupling with the equal dimension rolling mechanism. The forecasting result indicates that energy demand will reach up to 3. 19 billion tons of coal equivalent (BTCE) in 2010 and 3. 63 BTCE in 2015, respectively, and it will present the huge challenge in terms of the safety of energy supply. [ABSTRACT FROM AUTHOR]