On the synergy between electrical and photonic switching

This article focuses on the values of electrical switching vs. photonic switching in the context of telecom transport networks. In particular, we show that the requirement of providing agility at the optical layer in the face of traffic forecast uncertainties is served better through photonic switching. On the other hand, some of the network-level functions, such as fast protection, subwavelength aggregation, and flexible client connectivity, require electrical switching. We further argue that additional values are achieved with hybrid photonic and electrical switching, which do not exist when either of these options is used in isolation.     

Bandpass filters with reconfigurable transmission zeros using varactor-tuned tapped stubs

In this letter, bandpass filters with one or two tunable transmission zeros are proposed. The reconfigurable transmission zeros are implemented through varactors in combination with tapped quarter-wavelength stubs. Based on mixed mode simulations including EM simulation and circuit simulation, the proposed filters were designed and fabricated on low-cost FR4 board. The measurement results verified the design concepts.     

Towards intelligent dressing

The aim of this article is to state the principles of an intelligent monitoring and control system for the grinding machine, comprising the dressing process as well as grinding stability.     

Self-oscillating dimmable electronic ballast

This paper presents a simple alternative for an electronic ballast operating in self-sustained oscillating mode with dimming capability for fluorescent lamps. A simple modification in one of the gate drivers side circuit allows the lamp to dim without compromising the simplicity, reliability, and low cost which characterize the self-oscillating electronic ballast (SOEB). A qualitative analysis is presented to explain the behavior of the proposed self-oscillating electronic ballast with dimming feature. In addition, the stability and the key equations for the design are derived using the extended Nyquist criterion and describing function method. Experimental results from two 40-W electronic ballasts are presented to demonstrate the performance and to validate the analysis carried out.     

Microchemical Engineering: Components,Plant Concepts User Acceptance – Part I

Over the last five years, many activities have focused on the unexploited field of carrying out reactions on small scales. Due to the rapid development of new components, this paper deals with recent developments only in a compressed form. An important point is the analysis of possible plant concepts for microreactors and whether these are a sensible option. Due to the enormous difference in size between the microchannels and the fluid periphera of possible components this is not just a technical question. It touches on the microtechnology concept as a whole. The direction in which the field should be developed and which measures can be taken to influence its development are questions that are addressed here with respect to the big industrial interest in microreactors.     

A military perspective on small unmanned aerial vehicles

In recent years, advancements in three technology areas, microelectronics, MEMS sensors, and GPS receivers, have allowed small UAVs to overcome critical deficiencies and become practical for insertion into the military mainstream. The maturation and commercialization of these technologies have resulted in readily available components that have decreased in both size and cost, to the point where truly low-cost, highly capable, small UAVs are possible. In particular, inertial devices such as MEMS accelerometers and angular rate sensors, pressure sensors, and magnetometers have reached the point where they are reliable, accurate, and affordable. These devices allow the determination of vehicle state with the precision required to enable autonomous flight. In addition, advanced microelectronic devices, such as digital signal processors, field programmable gate arrays, and microcontrollers have enabled sophisticated flight control functions, including fully autonomous flight using GPS waypoints. In combination, these advances have allowed small UAVs such as Pointer, Raven, and Dragon Eye to move into full-scale production and continue to allow the progression of UAVs into smaller and smaller packages. To address several of the deployment issues connected with small UAVs, a gun-launched version, along with the underpinning technologies, is under development. This device represents a clear departure from conventional UAVs with several clear advantages; however, it also contains severe design challenges, as well as test and evaluation dilemmas. An option of this type is envisioned not as a replacement for conventional small UAVs but rather as an augmenting capability.     

镍层耐硝酸腐蚀性测试——一种简单的预先探测ENIG镍层“黑盘”现象的测试方法

随着更加精细的SMT、BGA等表面贴装技术的运用,化学沉镍金(ENIG)作为线路板最终表面处理得到了越来越广泛的应用,同时可怕的“黑盘”现象也随之更广泛地“流行”起来,直接导致贴装后元器件焊接点不规则接触不良。为了贯彻执行最好的流程控制和采取有效的预防措施,了解这种焊接失败的产生机理是非常重要的,及早的观测到可能发生“黑盘”现象的迹象变得同样关键。本文介绍了一种简单的预先探测ENIG镍层“黑盘”现象的测试方法-镍层耐硝酸腐蚀性测试,这种测试可以用于作为一种常规的测试方法监测一般化学沉镍溶液在有效使用寿命范围内新鲜沉积的镍层的质量。利用Weibull概率统计分析在不同的金属置换周期(MTO)下镍层的可靠性能表现。结合试验结果得出了一个镍层耐硝酸腐蚀性的判定标准。     

Changes in the gaseous H2S barrier properties of damaged silicate coated nylon 6 films

The damage imposed on SiO _x deposited nylon 6 films as a result of abrasion with a cotton cloth and Gelboflex testing was examined by evaluating the rate at which copper plates, which were enveloped by the damaged films, were corroded by H₂S. Abrasion with a cotton cloth caused some micro-cracking of the SiO _x layer and the permeation rate of H₂S approached that of the uncoated nylon 6 film. Damage to the SiO _x layer by twisting and crushing progressed gradually with the number of Gelboflex test cycles and correspondingly the corrosion rate of the copper plates increased. Comparison of the corrosion rates of the copper plates kept in the pouches made of various commercial films with those obtained for the damaged SiO _x deposited nylon 6 films showed a clear relationship between the H₂ permeation rate of the films and the corrosion rate of the copper plates by H₂S.