Noncontact optical fiber coating removal technique with hot air stream

We will discuss a novel noncontact removal technique of optical fiber coating in continuous and uninterrupted manner with hot air stream. We observed the mean breaking tensile strengths of the optical fibers coated with the UV-cured protective polymer and stripped using noncontact removal method were 5.6 and 5.1 GPa, respectively. A high-speed camera with 10 000 frames/s frame rates was used to observe the sequential steps of the explosion and vaporization of optical fiber coating materials.     

制作在不锈钢薄膜衬底上的柔性电子图书显示器

2005年10月,LG.PhilipsLCD和EInk公司联合推出了一款10.1in的SVGA反射式柔性有源矩阵光电显示器,该显示器成功地制作在一个薄薄的不锈钢薄膜衬底上。该产品原型在外观上和手感上与真实的纸张极为相似,非常薄且轻,并且具有宽视角和高对比度。     

Effect of Yarn Type and Twist Factor on Air Permeability,Absorbency, and Hand Properties of Open-end and Ring-spun Yarn Fabrics

The paper investigates the effects of yarn type, i.e. open-end yarn (OE) and ring-spun yarn (RS) and the twist factors of the warp (W) and filling (F) of the OE yarns on the permeability to air and moisture and the hand properties of various test fabrics woven from both OE and RS yarns. A comparison is made of the effect of yarn types and various twist levels of warp and filling of the OE yarns on the air permeability, absorbency, coefficient of friction and flexural rigidity of fabrics woven from such yarns.

It is intended that future studies will explore a wider range of twist levels and different yarn types than those investigated on this initial exercise.     

Phase of acoustic impedance and performance of standing wave thermoacoustic coolers

Investigations on the relations between the phase angle of the acoustic impedance at the driver piston and the system performance of a standing wave thermoacoustic cooler were performed. The system performance measured at a fixed acoustic power showed that the coefficient of performance of the standing wave thermoacoustic cooler increases as the phase angle increases when the stack temperature span is relatively low. The results were consistent with the simulation results obtained from DELTAE, a computer code based on linear thermoacoustic theory. Analysis on the temperature profiles along the stack showed that the cooling efficiency (COP) of the system could be decreased or increased as the phase angle of the acoustic impedance at the driver piston changes depending on the stack temperature spans. This paper was recommended for publication in revised form by Associate Editor Yeon June Kang Insu Paek received the B.S. degree in Mechatronics Engineering from Kangwon National University, Chuncheon, Korea, in 1997, the M.S. degree in Mechanical Engineering from the University of Texas at Austin, USA, in 2000, and the Ph. D. degree in Mechanical Engineering from Purdue University, West Lafayette, USA, in 2005. He worked as a postdoctoral researcher in Purdue University and McGill University in 2006 and 2007. He is currently a faculty member in the Department of Mechatronics Engineering, Kangwon National University, Chuncheon, Korea. His research interests include thermoacoustic cooling and power generation, solar heat driven absorption cooling., and wind power. Luc Mongeau received the B.S. and M.S. degrees in mechanical engineering from the University of Montreal, QC, Canada, in 1984 and 1986, respectively, and the Ph. D. degree in Acoustics from Pennsylvania State University, University Park, USA, in 1990. He is currently a professor in the Department of Mechanical Engineering at McGill University, Montreal, QC, Canada. He has published over 50 archival journal publications on various topics related to acoustics and noise control. His research activities are in the flow and turbomachinery noise areas, as well as in the areas of voice production, and thermoacoustic refrigeration. James E. Braun received the B.S. degree in Mechanical Engineering from the University of Massachusetts, USA, in 1976, and the M.S. and Ph. D. degrees in Mechanical Engineering from the University of Wisconsin, Madison, USA, in 1980 and 1988, respectively. He is currently a professor in the Department of Mechanical Engineering, Purdue University, West Lafayette, USA. Professor Braun’s research combines the use of computer modeling, optimization, and experiments to study and improve the performance of thermal systems. He has published over 140 papers. Professor Braun is currently an associate editor for the international journal of HVAC&R Research. Shin You Kang received the B.S. and M.S. degrees in the Department of Mechanical Design from Seoul National University, Seoul, Korea, in 1982, and 1986, respectively. He then received the Ph.D. in Mechanical Engineering at the same university in 1992. Professor Kang is currently a professor in the Department of Mechatronics Engineering, Kangwon National University, Chuncheon, Korea. His research interests include mechanical structure design, crash analysis, optimal design, computational structure analysis and evaluation.     

Effects of annealing on the damage morphologies in BF 2 + ion implanted (1 0 0) silicon

The effects of annealing on the damage morphologies and impurity redistributions in BF ₂ ⁺ ion implanted (1 0 0) silicon were studied using secondary ion mass spectrometry (SIMS), transmission electron microscopy (TEM) and Rutherford backscattering (RBS) ion beam channelling technique. An amorphized silicon layer and a heavily-damaged crystal layer containing a high density of point-defect clusters, are formed on the silicon wafer by the ion implantation. SIMS depth profiles of both boron and fluorine are almost Gaussian distribution. Both furnace annealing and rapid thermal annealing cause recrystallization of the amorphized layer and formation of dislocation loop bands out of the point defects. SIMS depth profiles for both impurities show anomalous double peaks at the same depths. These facts suggest that the primary peak is due to the peak of the Gaussian distribution and the secondary peak due to the gettering effects of residual dislocation loop band.     

An advanced compiler framework for non-cache-coherentmultiprocessors

The Cray T3D and T3E are non-cache-coherent (NCC) computers with a NUMA structure. They have been shown to exhibit a very stable and scalable performance for a variety of application programs. Considerable evidence suggests that they are more stable and scalable than many other shared-memory multiprocessors. However, the principal drawback of these machines is a lack of programmability, caused by the absence of the global cache coherence that is necessary to provide a convenient shared view of memory in hardware. This forces the programmer to keep careful track of where each piece of data is stored, a complication that is unnecessary when a pure shared-memory view is presented to the user. We believe that a remedy for this problem is advanced compiler technology. In this paper, we present our experience with a compiler framework for automatic parallelization and communication generation that has the potential to reduce the time-consuming hand-tuning that would otherwise be necessary to achieve good performance with this type of machine. From our experiments, we learned that our compiler performs well for a variety of applications on the T3D and T3E and we found a few sophisticated techniques that could improve performance even more once they are fully implemented in the compiler     

Leaky mode directional coupler for prism coupling interconnection

A leaky mode directional coupler was fabricated with its beam shaped into a Gaussian-like profile and was experimentally demonstrated for suppressing the diffraction of an out-coupled beam. The demonstrated coupler consists of a multilayered waveguide with six layers that are embedded in a symmetric slab waveguide. The out-coupled beam profile was measured to be shaped into a Gaussian function by using the prism coupling method. There was an excellent agreement between the measured and theoretically predicted coupling angles, and it was also confirmed that the diffraction was suppressed.     

Residual stresses in a doubly clad fiber with depressed innercladding (DIC)

Thermal and mechanical stresses developed in concentric three-layered optical fiber-core, and inner and outer cladding, have been thoroughly studied for various concentrations of dopants and geometric structures. In order to examine the parametric results of thermal stresses in preforms, the stresses were measured with a polariscope. The results agreed well with the theoretical calculations. The thermal stresses were calculated for three temperature ranges in which the glass in each layer has a different thermal expansion coefficient. The mechanical stresses were studied considering the normal stress in the molten neck down region and its development with time. In order to include the time dependence of the stress below softening point, Maxwell's one dimensional viscoelasticity was applied. In a parametric study, the analyzes were carried out based on the fiber parameters such as relative index difference, ratio of clad to core, and depressed relative index difference. With an increase of core index above the silica, the thermal stresses in core increased linearly, but the depressed inner clad does not affect the stresses in core. From the parametric studies and modeling it was found that when the depressed inner cladding (DIC) layer has a large cross-section or high dopant concentration, the mechanical stress in core change from compression to tension