ESD phenomena in GMR heads in the manufacturing process of HDD and GMR heads

It is well known that giant magnetoresistive (GMR) heads used for hard disk drives (HDD) are very sensitive to electrostatic discharge (ESD). In this paper, we describe a method of categorizing ESD damage modes from a standpoint of magnetic influences on the heads as observed by quasi-static test (QST) characteristics as well as electromagnetic characteristics like off-track profiles. In addition, we report an example of GMR stack interlayer diffusion which is one type of hard ESD damage. We also present an example of ESD damage that happened in an actual production process and its preventive measures as guidelines.     

Immobilization of glucose oxidase on nonwoven fabrics with bombyx mori silk fibroin gel

The enzyme glucose oxidase (GOD) was immobilized on the nonwoven fabrics, which have excellent properties in diffusivity of substrates, mechanical strength, and handling, with Bombyx mori silk fibroin gel. The nonwoven fabrics of silk fibroin, viscose rayon, poly-ethyleneterephthalate, 6-nylon, and polypropylene with activated surface by fluoline treatment were used. The stabilities of GOD to heat or pH changes were much improved by the immobilization as well as the case of the GOD immobilized in the silk fibroin membrane. Among nonwoven fabrics, silk fibroin was the most excellent support material for the immobilization of GOD although all nonwoven fabrics used here are able to be used as the support materials. The increase of the sensitivity was observed when the glucose sensor was made with the GOD immobilized on nonwoven silk fabrics as four times compared with the case of the GOD immobilized in the silk fibroin membrane.     

Elastic small deflection analysis of annular sector Mindlin plates

An analytical method is developed for the bending response of annular sector Mindlin plates with two radial edges simply supported, and exact solutions are presented in the form of Levy-type series. Several different boundary conditions on the two circular edges are considered, viz. simply supported-simply supported, clamped-clamped and free-free. Numerical results for the case of uniform loading are presented to indicate the effect of shear deformation on the deflections and stress resultants at various points in the plate. Twisting stress couple and transverse shear stress resultant distributions along and near the edges of the plate are illustrated graphically, and the principal differences between the results predicted by Mindlin's plate theory and classical thin plate theory are discussed in detail. Results obtained with the present exact analysis may serve as references for approximate solutions and, especially, as a ‘shear locking’ test for thick plate finite element analysis.     

Modeling And Solving An Engine Intake Manifold With Turbo Charger For Predictive Control

In this paper, we build the intake manifold model of an engine with a turbo charger and develop a high speed calculation algorithm for model‐based predictive control in real time. The model is built according to the analysis of its thermodynamic and hydrodynamic characteristics and the sampled experiment data. The model equations are presented as a set of differential equations with condition selection (bifurcation) on the right hand side. The switching surface is divided into two parts, sliding and crossing. The sliding mode on the switching surface is analyzed in detail, and a calculation algorithm is proposed to remove illegal crossing caused by the numerical errors on this surface. Also, the control formula and the condition guiding the bifurcation between these two parts are demonstrated. Using this method, we can solve this model over the entire region of input throttle angles, the stability is greatly increased, and the calculation time is greatly reduced for real time control systems.     

Co-based superstructured nitride alloy films: characteristics andapplications for high frequency heads

Co-based superstructured films composed of 25-nm-thick non-nitride and nitride layers were prepared by N₂ reactive RF sputtering. The films have high 4πM_s=13 kG, a high permeability μ=3000, and a high thermal stability of the magnetic properties. Magnetic heads composed of laminated superstructured films insulated with SiO₂ films were developed for high-frequency operations. The heads show excellent recording capability for narrow gap recording with metal tapes and high reproduction characteristics at frequencies over 10 MHz. They achieve an increase of more than 4 dB in normalized output when compared with conventional laminated-type amorphous film heads. The superstructured nitride film heads are expected to be used in next-generation VCRs, which operate with higher density recording and wider frequency bands     

The Effects of Thermoelectric Film Thickness on Performance of In-Plane Thermoelectric Modules

We fabricated in-plane thermoelectric modules (4?mm?×?4?mm) on a 4-??m-thick substrate using a vacuum deposition process through a shadow mask. In this study, a thermoelectric p?Cn pair was established using multilayered films of p and n thermoelectric thin films and an insulator film with a hole at the center. The output power was 58?nW at 443?K using the multilayered microgenerator. We discuss the effects of device thickness on the efficiency of the microgenerator to increase the output electric power. We evaluated the output power of the in-plane thermoelectric generator with a substrate using a one-dimensional heat conduction model, and it was found to depend on the thickness of the thermoelectric film. If the thermoelectric film is very thin, the power factor is more important than the nondimensional figure of merit, ZT. Metal thin films with high power factor are more efficient than semiconductors with low power factors even though their thermal conductivities are high. When the thermoelectric thin film is thick, ZT should be higher for larger output power of the device.     

Simple Salt‐Coordinated n‐Type Nanocarbon Materials Stable in Air

After more than three decades of molecular and carbon‐based electronics, the creation of air‐ and thermally stable n‐type materials remains a challenge in the development of future p/n junction devices such as solar cells and thermoelectric modules. Here a series of ordinary salts are reported such as sodium chloride (NaCl), sodium hydroxide (NaOH), and potassium hydroxide (KOH) with crown ethers as new doping reagents for converting single‐walled carbon nanotubes to stable n‐type materials. Thermoelectric analyses reveal that these new n‐type single‐walled carbon nanotubes display remarkable air stability even at 100 °C for more than 1 month. Their thermoelectric properties with a dimensionless figure‐of‐merit (ZT) of 0.1 make these new n‐type single‐walled carbon nanotubes a most promising candidate for future n‐type carbon‐based thermoelectric materials.     

基于无线传感器网络和ICA的桥梁诊断系统

为桥梁的日常维护开发了-个桥梁诊断系统.其所用的技术包括:无线传感器网络、信号处理和桥梁结构分析等技术.通过无线传感器网络收集由外力所产生的振动数据,这些外力包括:风、水流、驶过的车辆等.然后用独立成分分析(ICA)和频谱分析方法来分析所收集的数据以提取桥梁的特征频率.这个系统可以识别桥梁的老化和腐蚀等现象.因此,这个诊断系统可以用来评估桥梁的健康状况,然后根据实际情况考虑进行一个全面的修理和加固.已经用此诊断系统在日本福冈北九州市的小仓青岚桥进行了现场实验,成功地提取了该桥的桥墩的特征频率.