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.

/pdf/etch-rates-for-micromachining-processing-29z80ltijs.pdf

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.

/pdf/a-review-of-tactile-sensing-technologies-with-applications-12ul5smpoy.pdf

A review of tactile sensing technologies with applications in biomedical engineering

This paper deals with the in-plane vibration of circular annular disks under combinations of different boundary conditions at the inner and outer edges. The in-plane free vibration of an elastic and isotropic disk is studied on the basis of the two-dimensional linear plane stress theory of elasticity. The exact solution of the in-plane equation of equilibrium of annular disk is attainable, in terms of Bessel functions, for uniform boundary conditions. The frequency equations for different modes can be obtained from the general solutions by applying the appropriate boundary conditions at the inner and outer edges. The presented frequency equations provide the frequency parameters for the required number of modes for a wide range of radius ratios and Poisson's ratios of annular disks under clamped, free, or flexible boundary conditions. Simplified forms of frequency equations are presented for solid disks and axisymmetric modes of annular disks. Frequency parameters are computed and compared with those available in literature. The frequency equations can be used as a reference to assess the accuracy of approximate methods.

https://downloads.hindawi.com/archive/2010/501902.pdf

Frequency Equations for the In-Plane Vibration of Circular Annular Disks

A biocompatible polydimethylsiloxane (PDMS) biomicrofluidic platform is designed, fabricated and tested to study protuberance growth of single plant cells in a micro-vitro environment. The design consists of an inlet to introduce the cell suspension into the chip, three outlets to conduct the medium or cells out of the chip, a main distribution chamber and eight microchannels connected to the main chamber to guide the growth of tip growing plant cells. The test cells used here were pollen grains which produce cylindrical protrusions called pollen tubes. The goal was to adjust the design of the microfluidic network with the aim to enhance the uniformly distributed positioning of pollen grains at the entrances of the microchannels and to provide identical fluid flow conditions for growing pollen tubes along each microchannel. Computational fluid analysis and experimental testing were carried out to estimate the trapping efficiencies of the different designs.

Optimization of flow assisted entrapment of pollen grains in a microfluidic platform for tip growth analysis.

Machinability is one of the important properties of a material. It is about cutting the material with maximum metal removal, in shortest time, with best surface finish while having maximum tool life. The high quality of surface finish is very important in order to face the required accuracy and marketing needs. In this paper we present a technique for modeling a machining process of Alumic-79 with 2 and 4-flutes cutting head. In this paper, optimum parameters, which are feed rate, spindle speed and depth of cut, are found for 2-flutes and 4-flutes cutting head to obtain a high quality surface finish.

A technique for fuzzy logic modeling of machining process

Electrically controlled swash plate axial piston pumps with conical cylinder blocks are recently used in the industry in view of their superior performance. Several studies have been carried out to study the characteristics of such novel pump mechanism. In these studies, partial mathematical modeling is conducted relevant to the points discussed. In the present study, a comprehensive pump mathematical model is developed and experimentally validated. The model could be used as a design tool in order to fully exploit the advantages of the new design.

Modeling of Swash Plate Axial Piston Pumps With Conical Cylinder Blocks

A semi-active control strategy for suspension systems of passenger cars is presented employing Magnetorheological (MR) dampers. The vehicle is modeled with seven DOFs including the, roll pitch and bounce of car body, and the vertical motion of the four tires. In order to design an optimal controller based on the actuator constraints, a Linear-Quadratic Regulator (LQR) is designed. The design procedure of the LQR consists of selecting two weighting matrices to minimize the energy of the control system. This paper presents a hybrid optimization procedure which is a combination of gradient-based and evolutionary algorithms to choose the weighting matrices with regards to the actuator constraint. The optimization algorithm is defined based on maximum comfort and actuator constraints. It is noted that utilizing the present control algorithm may significantly reduce the vibration response of the passenger car, thus, providing a comfortable ride. Keywords—Full car model, Linear Quadratic Regulator, Sequential Quadratic Programming, Genetic Algorithm

Rama B. Bhat

Papers

Frequency Equations for the In-Plane Vibration of Circular Annular Disks

Optimization of flow assisted entrapment of pollen grains in a microfluidic platform for tip growth analysis.

A technique for fuzzy logic modeling of machining process

Modeling of Swash Plate Axial Piston Pumps With Conical Cylinder Blocks

Ride Control of Passenger Cars with Semi-active Suspension System Using a Linear Quadratic Regulator and Hybrid Optimization Algorithm