Trapezoidal Pattern Research Articles

연성파괴조건을 사용한 용융탄산염 연료전지용 쉴디드 슬롯 플레이트의 성형 공정 유한요소 해석

The shielded slot plates for a molten carbonate fuel cell(MCFC) have a sheared corrugated trapezoidal pattern. In the FEM simulations for the production of the shielded slot plate, the user material subroutine VUMAT in the commercial FEM software ABAQUS was used to implement a ductile fracture criterion. The critical damage value for the ductile fracture criterion was determined by comparing the experimental results of the shearing process with the simulation results. Using the ductile fracture criterion, the FEM simulation of the three-dimensional forming process of the shielded slot plate was conducted. The effects of the shearing process on the forming process were examined through FEM simulation and experiments. The forming simulation of nine unit cells was conducted. Using the simulation results of the forming process, the deformed shape after springback was calculated. The experimental result shows good agreement with the simulation.

Analysis and Experiment of Residual Load Sway Suppression in Rotary Crane Systems Using Simple Trajectory for Horizontal Boom Motion

To suppress two-dimensional load sway caused by the horizontal boom motion of a rotary crane, both horizontal and vertical boom motions are generally used. However, it would be more energy efficient and safer if a control scheme is developed that only used horizontal boom motion, eliminating the need for any vertical boom motion. In addition, if we can suppress load sway without the need to measure it, reduction in the cost of sensors can be achieved. Furthermore, use of simple velocity trajectory patterns such as a trapezoidal velocity pattern and an S-curve acceleration/deceleration pattern, which are widely used in industrial automation systems, may provide costeffective implementation of controllers. This study examines the analytical conditions for a simple S-curve trajectory of horizontal boom motion to suppress residual load sway without sensing it. Numerical simulation and experimental results demonstrate the effectiveness of the proposed conditions.

S-Curve Trajectory Generation for Residual Load Sway Suppression in a Rotary Crane System Using Only Horizontal Boom Motion

Generally, both horizontal and vertical boom motion must be used to suppress the load sway caused by horizontal boom motion of a rotary crane. However, it would be less energy intensive and also safer if a control scheme could be developed that only used horizontal boom motion, i.e., without the need for any vertical boom motion. In addition, if load sway can be suppressed without measuring it, reduction in sensor cost can be achieved. Furthermore, employing simple velocity trajectory patterns such as trapezoidal and S-curve patterns, which are widely used in industrial automation systems, may provide cost effective controller implementation. This study presents a simple S-curve trajectory generation method for rotary crane motion that can suppress residual load sway using only horizontal boom motion without load sway sensing. Numerical simulations and experimental results demonstrate the effectiveness of the proposed method.

Optimal discount time for seasonal products with trapezoidal type price and time sensitive demand pattern

The trapezoidal type demand rate with respect to time allows three-phase variation, representing the growth, the steady and the decline phases of demand with respect to time commonly experienced by most seasonal products during their life cycle in the market. It is well observed that a temporary discount on selling price provides significant increment in demand rate for seasonal products. Temporary price discount is an integral part of sales promotion scheme. In this paper we investigate in which time phase a temporary discount on selling price may be given to maximize the profit per unit time. Mathematical models are developed to find some important characteristics of discount starring time. Numerical examples are provided to illustrate the results of proposed models.

High-speed 3D surface profilometry employing trapezoidal phase-shifting method with multi-band calibration for colour surface reconstruction

This paper presents a new optical measurement method employing a HSI (hue, saturation and intensity) colour model to form trapezoidal structured patterns for morphology reconstruction of a measured object at high speed. Profilometry on objects having non-monochromatic surfaces is considered as one of the remaining challenges most faced by the currently existing structured-light projection methods since the surface reflectivity to red, green and blue light may vary significantly. To address this, an innovative colour calibration method for a hue component is developed to determine the accurate reflectivity response of the measured surface. The trapezoidal colour pattern is calibrated to compensate the hue-shifted quantity induced by the reflective characteristics of the object's surface. The developed method can reconstruct precise 3D surface models from objects by acquiring a single-shot image, which can achieve high-speed profilometry and avoid in situ potential measurement disturbances such as environmental vibration. To verify the feasibility of the developed methodology, some experiments were conducted to confirm that the measurement accuracy can be controlled within 2.5% of the overall measurement range and the repeatability of 3.0% within ±3σ can be achieved.

Molecular dynamics study on the effects of stamp shape, adhesive energy, and temperature on the nanoimprint lithography process

Molecular dynamics simulations of nanoimprint lithography (NIL) were performed to investigate the effects of three critical process parameters in NIL: stamp shape, adhesive energy between the stamp and polymer film, and imprint temperature. The proposed simulation model of the NIL process consists of an amorphous SiO 2 stamp with a line pattern, an amorphous poly(methylmethacrylate) film, and a Si substrate under the periodic boundary condition in the horizontal direction to simulate a real NIL process imprinting periodical line patterns. The behavior of polymer deformation and the effects of adhesion on pattern transfer were investigated by observing the deformation process, calculating the imprint and separation forces, and analyzing the density and stress distribution inside the polymer film. In addition, their dependency on the process parameters is also discussed with reference to the changes in pattern shape, adhesive energy between the stamp and polymer atoms, and imprint temperature of the polymer film. During the imprint process, the rectangular pattern shows inferior cavity filling and higher stress concentration compared to trapezoidal and triangular patterns because it requires much larger flow and deformation of the polymer film. Low imprint temperature also produces high stress concentration and large imprint force due to the lower fluidity of polymer film. In the separation process, the rectangular pattern generates the largest separation force and causes the most serious defects of the transferred pattern and even the polymer film, while the triangular pattern shows the most satisfactory pattern transfer. In addition, the adhesive energy between the stamp and the polymer film also strongly influences the adhesion between the stamp and the polymer film. Low adhesive energy reduces the separation force of the stamp and transferred pattern defects, and therefore enhances the quality of pattern transfer.

The impact of two-product joint lifecycles on capacity planning of remanufacturing networks

Abstract Capacity planning in the reverse channel of closed-loop supply chains (CLSCs) involves complex issues due to the different lifecycles of product offerings in combination with the variability regarding product usage time, quality level of used products and return patterns. (Georgiadis, P., Vlachos, D., Tagaras, G., 2006. The impact of product lifecycle on capacity planning of closed-loop supply chains with remanufacturing. Production and Operations Management 15; 514–527) developed a system dynamics (SD) model to study a CLSC with remanufacturing for a single product which incorporates a dynamic capacity modeling approach. We extend this SD model for two sequential product-types under two alternative scenarios regarding the market preferences over the product-types; in the first scenario, the market is considered showing no preferences, while in the second scenario, the demand over a product-type can be satisfied only by providing units of the specific type. We study how the joint lifecycles of two product-types, entry time of the second product-type to the market and used product return patterns affect the optimal policies regarding expansion and contraction of collection and remanufacturing capacities. The results of extensive numerical investigation are tested for their statistical significance using analysis of variance (ANOVA). In the first scenario, the results show that the system performs best when the two lifecycles form a trapezoid pattern for total demand while in the second scenario, when the two lifecycles form a triangular pattern.

High Speed 3-D Surface Profilometry using HSI Color Model and Trapezoidal Phase-Shifting MethodHochgeschwindigkeits-3D-Oberflächenprofilometrie mit HSI-Farbmodell und Trapez-Phasenverschiebungsmethode

Abstract To achieve high-speed profilometry and avoid in-field vibration disturbances, high-speed 3-D surface profilometry using an innovative HSI color model and trapezoidal phase-shifting method has been developed to detect the morphology of measured objects at a high speed. By employing novel phase-shifting trapezoidal color fringe patterns, the method can reconstruct precise 3-D surface models by single one-shot image. Some industrial measurements were conducted to confirm that the measurement accuracy reached to 2.5% of the overall measurement range and the repeatability of 3.0% within ±3σ was achieved.

Wedge-Shaped Excision and Modified Vertical Mattress Suture Fully Buried in a Multilayered and Tensioned Wound Closure

A successful deep multilayered wound suture should provide a firm tension-relieving closure, good wound-edge eversion, hemostasis, and minimal intradermal extraneous materials. However, this is not always achieved with a single standard technique. The authors describe their modification of a wound closure method that can rapidly and reliably achieve these results. A wedge-shaped excision was adopted to obtain a trapezoid pattern transect, after which a modified fully buried vertical mattress suture technique was used to close the wound. These techniques were compared with the standard excision and suture techniques used for the same patient at different times after surgery. The wedge-shaped excision can facilitate good wound-edge eversion, and the modified fully buried vertical mattress suture can provide firm tension relief and optimal apposition. Compared with conventional excision and suture techniques, the described techniques brought about a better outcome in terms of hypertrophic scar prevention. The described modified technique seems to be more efficient than conventional procedures used to prevent hypertrophic scar formation.

ER stress protects from retinal degeneration

The unfolded protein response (UPR) is a specific cellular process that allows the cell to cope with the overload of unfolded/misfolded proteins in the endoplasmic reticulum (ER). ER stress is commonly associated with degenerative pathologies, but its role in disease progression is still a matter for debate. Here, we found that mutations in the ER-resident chaperone, neither inactivation nor afterpotential A (NinaA), lead to mild ER stress, protecting photoreceptor neurons from various death stimuli in adult Drosophila. In addition, Drosophila S2 cultured cells, when pre-exposed to mild ER stress, are protected from H(2)O(2), cycloheximide- or ultraviolet-induced cell death. We show that a specific ER-mediated signal promotes antioxidant defences and inhibits caspase-dependent cell death. We propose that an immediate consequence of the UPR not only limits the accumulation of misfolded proteins but also protects tissues from harmful exogenous stresses.

Numerical study on fluid-flow characteristics of peristaltic pump

Flow characteristics in a peristaltic pump, which can be applied to Micro Total Analysis Systems (μ-TAS), were numerically investigated. For the present computational analysis, we assumed a simple sinusoidal wave pattern to simulate the peristaltic motion of flexible channel wall and applied the Immersed Boundary method to the treatment of the wall boundary. The effects of the parameters such as the amplitude and velocity of the peristaltic motion upon the flow characteristics and pump performance were evaluated in the present paper. Saw-toothed or trapezoidal wall patterns were also calculated to examine the potentiality of the pumping flow rate increase.

Geometric aspects of AFM imaging

A geometric study of image generation in the AFM is reported. The relationship of an AFM waveform to the surface morphology being examined is determined, allowing for the influence of the radius and the vertex and obliquity angles of the tip. AFM calibration procedures are proposed and experimentally validated on trapezoidal surface patterns. Methods are described for direct measurement of linear dimensions, including linewidth, on the basis of original and differentiated AFM waveforms.

Abnormal Maxillary Trapezoid Pattern in Human Fetal Cleft Lip and Palate

To elucidate abnormal growth patterns of human fetal maxillae with cleft lip and palate (CLP). A total of 71 fetal maxillae with CLP were obtained from aborted human fetuses. Dimensions of the maxillary trapezoid (MT), formed by the maxillary primary growth centers (MxPGC), were taken from radiographic images. The CLP dimensions were compared with maxillary trapezoid dimensions of normal fetuses from a previous study (Lee et al., 1992). Cleft lip subjects without a cleft palate, unilateral cleft lip-alveolar cleft or cleft palate (UCL+A/UCLP), and bilateral cleft lip-alveolar cleft or cleft palate (BCL+A/BCLP) displayed abnormal MT patterns. MT abnormalities were most marked in the BCL+A/BCLP cohort. The MT growth of prenatal CLP maxillae was severely arrested, resulting in abnormal MT shape on palatal radiograms. BCL+A/BCLP subjects had a more protruded nasal septum than subjects with other types of CLPs, while UCL+A/UCLP subjects showed severe deviation of the protruded nasal septum toward the noncleft side. Cleft lip-only subjects also exhibited abnormal MT growth. MT is primarily involved in CLPs, so that the MT shape could be utilized as a sensitive indicator for the analysis of maxillary malformation in different types of CLPs.

Effects of cycle patterns of accelerated crucible rotation technique (ACRT) on the flows, interface, and segregation in vertical Bridgman crystal growth

The accelerated crucible rotation technique (ACRT) has been used extensively in crystal growth for the control of flow and segregation. However, the amelioration of the spin-up and spin-down flows for a favorable growth has not yet been fully understood. In this study, we investigate several ACRT schemes and discuss their effects on the flow, interface morphology, and solute segregation during the vertical Bridgman growth of succinonitrile (SCN) containing acetone. Both numerical simulation and visualization experiments are conducted. In addition to the triangular and trapezoidal patterns, stair-up, stair-down, and pulse schemes are proposed for a better flow and mixing control without much interface deformation. For all the ACRT schemes investigated here, the simulated results are in good agreement with the observed ones.

The dependency of the crack growth rate on the loading pattern and temperature in stress corrosion cracking of strain-hardened 316L stainless steels in a simulated BWR environment

The stress corrosion cracking (SCC) growth rate of a warm-rolled (WR) 316L stainless steel contoured double cantilever (CDCB) specimen was measured in high purity water at various temperatures and under various loading patterns. An alternating current potential drop (ACPD) technique was used to monitor the crack growth kinetics throughout the tests. The fracture surface exhibited typical intergranular SCC characteristics. Depending on the test conditions, three kinds of crack growth kinetics, i.e., increasing with time then becoming steady, being constant during the whole period, decreasing with time then becoming steady, were identified and are described. The steady state crack growth rate (CGR) values are used to quantify the effects of the loading pattern and the environmental temperature. A moderate increase in the crack growth rate was encountered by employing periods of unloading and reloading to form a trapezoidal loading pattern and the enhancement factor was found to depend on the holding time and the times for unloading and reloading. It was found that the crack growth is thermally activated; however, the apparent activation energy is not constant but seems to be greater at higher temperatures. Several types of temperature-dependent crack growth kinetics are proposed based on the rate-determining step for the crack growth. The present experimental results can be rationalized by considering multiple element processes such as aqueous mass transport and solid-state mass transport in the crack growth. The cracking mode, the temperature dependence of the crack growth rate, and the transient crack growth behavior for WR 316L SS after changing the environmental temperature are quite similar to those for a cold-worked(CW) 316L SS tested in the same environment, despite their different absolute crack growth rate values. The effect of yield strength on CGR is more significant at lower temperatures and the apparent activation energy for the crack growth rate seems to be lower in the material with a higher yield strength. Time-lag crack growth behavior was found at points during several test steps on WR 316L SS, for example, just after in situ pre-cracking and after increasing or decreasing the temperature, which is quite consistent with the results obtained with CW 316L SS. The importance of in situ monitoring of the crack growth for obtaining steady state crack growth rates is emphasized, especially for those steps for which a nonlinear crack growth period occurs after changing the test condition.

617 ステッピングモータで駆動される3自由度半導体ウエハ搬送ロボットの軌道追従制御

This study deals with the trajectory tracking control of a three-degree-of-freedom semiconductor wafer transfer robot driven hybrid stepping motors. The desired trajectory of the end of the robot is set to be a straight line, and the desired posture of the third link is constant. The high-precision control of the hybrid stepping motor is executed with the microstep drive technique. The desired joint angle is obtained by the microstep technique and the trajectory planning based on the inverse kinematics. The desired trajectories with the fourth-order polynomial and the trapezoidal velocity pattern are used as the desired trajectory of the end of the third link. From the numerical calculation results and the experimental results, it is confirmed that the trajectory tracking control of the three-degree-of-freedom semiconductor wafer transfer robot can be successfully executed by the present high-precision control system with microstep drive technique.

Computer design of combinatorial shadow mask for ternary composition spread library

A simple rotational shadow masking system has been designed by computer simulation for application to the fabrication of a ternary composition spread material library. A mask plate is stencilled off a right triangle pattern and a trapezoid pattern. This can define the thickness gradient of films deposited from three different sources along the axes between the tops and the mid-points of bottom lines of a triangle on a substrate surface. Optimizing the angles of the triangle and trapezoid patterns and regulating the rates of mask moving, the computer simulation predicts that the film thickness of each component varies linearly from one mono-layer at the top to zero at the bottom. This process enables the construction of a ternary phase diagram by repeating the film deposition sequence. This prediction has been mathematically derived in this study.

環境調和型石炭利用システム共同実証事業，選炭技術に係る実証事業（中国），実証運転の成果について 脱硫・脱灰性能に優れた選炭技術

This model project had been carried out since 1997 Japanese fiscal year (JFY) to 2001 JFY by the subsidy from New Energy and Industrial Technology Development Organization (NEDO) in order to demonstrate the effect of the new coal preparation technology system on de-ashing and de-sulfurizing of high-sulfur raw coal. The system consists of "VARI-WAVE" air-pulsated jig, high-shear mixer, flotation cells, tailing thickener, pressure filter, central control facility and so on, with the throughput of 450 thousand ton per annum. The demonstration operation had been conducted since November 2001 to March 2002, at Jinjia Coal Preparation Plant, Panjiang Coal & Electric Power (Group) Co. Ltd., Guizhou Province, People's Republic of China. High sharpness of separation was obtained by "VARI-WAVE" air-pulsated jig owing to the trapezoidal pattern of water pulsation. Flotation of semi-anthracitic coal with low floatability was realized by use of high-shear mixer in advance. Also new type pressure filter has been operated with no trouble. By the demonstration operation, target values (de-sulfurizing ratio, de-ashing ratio and yield) stated in the Basic Agreement signed by Japanese and Chinese governments had been all verified.

A Hybrid Design Method of Velocity Patterns and Container Shapes in Straight Line Level Transport System of 2-Dimiensional Liquid Container.

This paper presents a method to degign the optimum container shape and the appropriate velocity patterns considering the damping of sloshing in liquid container transfer. The slope angle of sidewall of a container is selected to suppress the amplitude of sloshing. Further, the shaped velocity pattern reduces the residual sloshing after the end of acceleration or deceleration of transfer by using a preshaping method. The sloshing phenomena are numerically analyzed by a boundary element method (BEM). The trapezoidal velocity patterns and the optimum container shapes are studied through BEM simulations for various slope angles of the sidewall of the container. In terms of a golden section method, which is a unidimensional search technique, the optimum shape of the container and the trapezoidal velocity pattern were determined by minimizing the maximum amplitude of sloshing under the restriction such as the volume of liquid and the length of free surface of the liquid.

TECHNICAL NOTES: SPRINKLER APPLICATION PATTERN SHAPE AND SURFACE RUNOFF

Water application ratetime distribution patterns for many field irrigation data sets follow a trapezoidal pattern.The shape of the trapezoid influences the magnitude of potential surface runoff (surface storage plus actual runoff). Thereare scenarios in which the trapezoidal pattern produces more estimated potential runoff than the commonly used ellipticalpattern and other scenarios in which it yields less potential runoff. Water application patterns must be defined for eachsprinkler technology.