关于Semigroups of Linear Operators and Applications to Partial Differential Equations的两个注解

基礎講座 電気泳動(Electrophoresis)

This chapter introduces the finite element method (FEM) as a tool for solution of classical electromagnetic problems. Although we discuss the main points in the application of the finite element method to electromagnetic design, including formulation and implementation, those who seek deeper understanding of the finite element method should consult some of the works listed in the bibliography section.

Introduction to the Finite Element Method

The etch rates for 317 combinations of 16 materials (single-crystal silicon, doped, and undoped polysilicon, several types of silicon dioxide, stoichiometric and silicon-rich silicon nitride, aluminum, tungsten, titanium, Ti/W alloy, and two brands of positive photoresist) used in the fabrication of microelectromechanical systems and integrated circuits in 28 wet, plasma, and plasmaless-gas-phase etches (several HF solutions, H/sub 3/PO/sub 4/, HNO/sub 3/+H/sub 2/O+NH/sub 4/F, KOH, Type A aluminum etchant, H/sub 2/O+H/sub 2/O/sub 2/+HF, H/sub 2/O/sub 2/, piranha, acetone, HF vapor, XeF/sub 2/, and various combinations of SF/sub 6/, CF/sub 4/, CHF/sub 3/, Cl/sub 2/, O/sub 2/, N/sub 2/, and He in plasmas) were measured and are tabulated. Etch preparation, use, and chemical reactions (from the technical literature) are given. Sample preparation and MEMS applications are described for the materials.

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Etch rates for micromachining processing

Any device which senses information such as shape, texture, softness, temperature, vibration or shear and normal forces, by physical contact or touch, can be termed a tactile sensor. The importance of tactile sensor technology was recognized in the 1980s, along with a realization of the importance of computers and robotics. Despite this awareness, tactile sensors failed to be strongly adopted in industrial or consumer markets. In this paper, previous expectations of tactile sensors have been reviewed and the reasons for their failure to meet these expectations are discussed. The evolution of different tactile transduction principles, state of art designs and fabrication methods, and their pros and cons, are analyzed. From current development trends, new application areas for tactile sensors have been proposed. Literature from the last few decades has been revisited, and areas which are not appropriate for the use of tactile sensors have been identified. Similarly, the challenges that this technology needs to overcome in order to find its place in the market have been highlighted.

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A review of tactile sensing technologies with applications in biomedical engineering

Fluid film characteristics and shaft material damping form an interesting combination in rotor dynamic applications. Under certain conditions, a rotor which is unstable due to the damping, can be stabilized with the proper choice of fluid film bearings as supports. On the other hand, increasing the material damping in the rotor shaft can attenuate stress fluctuations in the rotors supported by fluid film bearings. The influence of the above combination on the stability of rotor bearing systems is investigated using a Jeffcot rotor with significant material damping and supported by fluid film bearings in the rotor dynamic model. The results indicate that under certain conditions, the interaction of the above two factors can be gainfully utilized in the design of rotor bearing systems. 8 refs.

Stability of rotors under the combined influence of fluid film bearing characteristics and shaft material damping

This paper presents evidence of the influence of the state of stress on anisotropic etching of (100) oriented Si in KOH water solution. External load is applied to strips of Si which modifies the initial internal stress state actually generated by a patterned SiO2 masking film. Results obtained for circular patterns indicate that the etch patterns on the strips subjected to negative and positive stresses are different from each other and are different from strips which have not been subjected to external loads. These observations indicate that the etching process is influenced by the presence of stresses in the silicon. A technique to analyze the stress is proposed. The resulting variations of etched features with applied stress is significant.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Influence of the stress state in silicon on the anisotropic etching process

Cantilever-based piezoelectric energy harvesters have been utilized as structures to extract mechanical energy from the ambient mechanical vibrations and transfer it into the electrical output. In ...

Analysis of bimorph piezoelectric beam energy harvesters using superconvergent element

Output-only modal testing is an effective technique to identify the modal parameters of structural systems under ambient or operational conditions and has potential applications in civil, mechanical, and aerospace engineering. It may effectively be used for model validation, model updating, quality control, and health monitoring through the determination of modal characteristics of the structures. This approach to modal testing has great potential for ground and on-orbit modal testing of space hardware, especially for flexible structures such as membrane payloads where the operating and ambient excitations, such as firing of AC thrusters and ambient thermal shock, are difficult or impossible to measure. The main objective of this work is to conduct analytical and experimental study on output-only modal testing and to demonstrate its potential application to effectively extract modal parameters of an on-orbit satellite appendage.

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Analytical and Experimental Study Using Output-Only Modal Testing for On-Orbit Satellite Appendages

Incinerated metal particles such as gold, silver, copper and iron are administered as internal medicines in the Indian systems of medicine, Siddha and Ayurveda, respectively. We studied the structure, composition and properties of the Incinerated Silver (IAg) particles (Veli parpam/Rajata bhasma) as well as their spectra and localisation in cancer cells (HeLa, A549 and HCT 116). The average crystallite size, particle size, and hydrodynamic diameter were found to be 54.6 nm, 300 nm to 1.7 m, and 530 nm-1.1 m, respectively. The particles have a negative surface charge with a zeta potential of -22.87±1.34 mV. The IAg particles are made up of Ag, Ca, Fe, Hg and other trace elements. Further, their subcellular properties and locations were analysed in cancer cell lines. The preliminary results obtained from the SEM and hyperspectral imaging show the uptake of the IAg particles and aggregates.

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Rama B. Bhat

Papers

Stability of rotors under the combined influence of fluid film bearing characteristics and shaft material damping

Influence of the stress state in silicon on the anisotropic etching process

Analysis of bimorph piezoelectric beam energy harvesters using superconvergent element

Analytical and Experimental Study Using Output-Only Modal Testing for On-Orbit Satellite Appendages

Study of Incinerated Silver Used in Indian Traditional Medicine Systems