Model of glow discharge between an electrolytic anode and a metal cathode

High Temperature - The results of the numerical simulation of the glow discharge between the pin cathode and the electrolytic anode are presented. The electron concentration distribution for the...     

Establishment and Characterization of Immortalized Miniature Pig Pancreatic Cell Lines Expressing Oncogenic K-RasG12D

In recent decades, many studies on the treatment and prevention of pancreatic cancer have been conducted. However, pancreatic cancer remains incurable, with a high mortality rate. Although mouse models have been widely used for preclinical pancreatic cancer research, these models have many differences from humans. Therefore, large animals may be more useful for the investigation of pancreatic cancer. Pigs have recently emerged as a new model of pancreatic cancer due to their similarities to humans, but no pig pancreatic cancer cell lines have been established for use in drug screening or analysis of tumor biology. Here, we established and characterized an immortalized miniature pig pancreatic cell line derived from primary pancreatic cells and pancreatic cancer-like cells expressing K-ras^G12D regulated by the human PTF1A promoter. Using this immortalized cell line, we analyzed the gene expression and phenotypes associated with cancer cell characteristics. Notably, we found that acinar-to-ductal transition was caused by K-ras^G12D in the cell line constructed from acinar cells. This may constitute a good research model for the analysis of acinar-to-ductal metaplasia in human pancreatic cancer.     

Investigation of interfacial slip in immiscible polymer blends

In this study, we investigated an interfacial slip phenomenon occurring in immiscible polymer blends. We chose a binary polymer blend in which the interaction parameter, χ, between the component polymers is high, and thus the interface is thin and entanglement is weak. It was observed that the negative viscosity deviation (NVD) of the blends is large, which might be attributable to interfacial slippage between the interfaces. It was also observed that incorporation of a compatibilizer in the blends significantly reduced the NVD, via suppression of interfacial slip due to increased interfacial strength. We carried out a specially designed experiment to verify that interfacial slip is indeed responsible for the NVD. We prepared several blend samples having different phase sizes ranging from 50 ∼ 5 μm, and evaluated the shear stress vs. shear rate relationships of the samples using a capillary rheometer. We observed that the viscosities of the samples decreased as the phase sizes decreased, which is strong evidence of the occurrence of interfacial slip.     

Exploring Nanomechanical Behavior of Silicon Nanowires: AFM Bending Versus Nanoindentation

Despite many efforts to advance the understanding of nanowire mechanics, a precise characterization of the mechanical behavior and properties of nanowires is still far from standardization. The primary objective of this work is to suggest the most appropriate testing method for accurately determining the mechanical performance of silicon nanowires. To accomplish this goal, the mechanical properties of silicon nanowires with a radius between 15 and 70 nm (this may be the widest range ever reported in this research field) are systematically explored by performing the two most popular nanomechanical tests, atomic force microscopy (AFM) bending and nanoindentation, on the basis of different analytical models and testing conditions. A variety of nanomechanical experiments lead to the suggestion that AFM bending based on the line tension model is the most appropriate and reliable testing method for mechanical characterization of silicon nanowires. This recommendation is also guided by systematic investigations of the testing environments through finite element simulations. Results are then discussed in terms of the size‐dependency of the mechanical properties; in the examined range of nanowire radius, the elastic modulus is about 185 GPa without showing significant size dependency, whereas the nanowire strength dramatically increases from 2 to 10 GPa as the radius is reduced.     

Effect of initial microstructure on mechanical properties in warm caliber rolling of high carbon steel

In this study, the effect of initial microstructure on change of mechanical properties was investigated by warm caliber rolling (WCR) of high carbon steel. Experiments were carried out with two different kinds of initial microstructures of pearlite and tempered martensite at the temperature of 500 °C. For comparison, the microstructure of austenite phase obtained from the conventional hot rolling at the temperature of 900 °C up to about 83% of the accumulative reduction in area was assumed to be a reference case. It was found that the WCR provided better mechanical properties in terms of strength and toughness compared to the conventional hot rolling based on experimental results of micro-hardness, tension, and Charpy impact tests. The improvement of strength and toughness was attributed to smaller ferrite grain and dispersed cementite particles with smaller interspacing aligned to the rolling direction after the WCR owing to field emission scanning electron microscopy. The investigated WCR might be useful in obtaining the high strength material with better toughness without adding new alloying elements for industrial applications according to the present investigation.     

Efficient Implementation of a Pseudorandom Sequence Generator for High‐Speed Data Communications

A conventional pseudorandom sequence generator creates only 1 bit of data per clock cycle. Therefore, it may cause a delay in data communications. In this paper, we propose an efficient implementation method for a pseudorandom sequence generator with parallel outputs. By virtue of the simple matrix multiplications, we derive a well‐organized recursive formula and realize a pseudorandom sequence generator with multiple outputs. Experimental results show that, although the total area of the proposed scheme is 3% to 13% larger than that of the existing scheme, our parallel architecture improves the throughput by 2, 4, and 6 times compared with the existing scheme based on a single output. In addition, we apply our approach to a 2×2 multiple input/multiple output (MIMO) detector targeting the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) system. Therefore, the throughput of the MIMO detector is significantly enhanced by parallel processing of data communications.     

The ZEUS forward plug calorimeter with lead–scintillator plates and WLS fiber readout

A Forward Plug Calorimeter (FPC) for the ZEUS detector at HERA has been built as a shashlik lead–scintillator calorimeter with wave length shifter fiber readout. Before installation it was tested and calibrated using the X5 test beam facility of the SPS accelerator at CERN. Electron, muon and pion beams in the momentum range of 10–100 GeV/c were used. Results of these measurements are presented as well as a calibration monitoring system based on a ⁶⁰Co source.     

Spheroidization of medium carbon steel fabricated by continuous shear drawing

This study was undertaken to propose a method of continuous shear drawing (CSD) for industrial applications to steel-wire manufacturing. The study compared the spheroidization behavior of medium carbon steel processed by CSD to that processed via conventional drawing. Microstructural observation revealed that the use of the CSD method was effective for deforming the pearlite colonies, resulting in wavy pearlitic cementites without noticeable cracks on the surface. After annealing treatment at a subcritical temperature of 973 K for 1 h, the CSD-deformed sample exhibited a uniform microstructure with a number of fine globular cementites that was greater in extent than that by drawing; this result was mainly due to the easy spheroidization triggered by the CSD strain.     

Queue management based duty cycle control for end-to-end delay guarantees in wireless sensor networks

In this paper, we propose an analytical method for duty cycle adaptation in wireless sensor networks so that delay requirement is guaranteed while power consumption is minimized. The proposed method, named Dual-QCon, provides a formal method for stabilizing controller design based on queue management in order to control both duty cycle and queue threshold according to changing network conditions. Dual-QCon also provides a delay notification mechanism in order to determine an appropriate queue threshold of each node according to the application-dependent and time-varying delay requirements. Based on control theory, we analyze the adaptive behavior of the proposed method and derive conditions for system stability. Asymptotic analysis shows that Dual-QCon guarantees end-to-end delay requirement by controlling parameters of local nodes. Simulation results indicate that Dual-QCon outperforms existing scheduling protocols in terms of delay and power consumption.