There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

The Design and Analysis of Experiments

International Journal of Computer and Applications

Humidity measurement is one of the most significant issues in various areas of applications such as instrumentation, automated systems, agriculture, climatology and GIS. Numerous sorts of humidity sensors fabricated and developed for industrial and laboratory applications are reviewed and presented in this article. The survey frequently concentrates on the RH sensors based upon their organic and inorganic functional materials, e.g., porous ceramics (semiconductors), polymers, ceramic/polymer and electrolytes, as well as conduction mechanism and fabrication technologies. A significant aim of this review is to provide a distinct categorization pursuant to state of the art humidity sensor types, principles of work, sensing substances, transduction mechanisms, and production technologies. Furthermore, performance characteristics of the different humidity sensors such as electrical and statistical data will be detailed and gives an added value to the report. By comparison of overall prospects of the sensors it was revealed that there are still drawbacks as to efficiency of sensing elements and conduction values. The flexibility offered by thick film and thin film processes either in the preparation of materials or in the choice of shape and size of the sensor structure provides advantages over other technologies. These ceramic sensors show faster response than other types.

/pdf/humidity-sensors-principle-mechanism-and-fabrication-q8mq7scozc.pdf

Humidity Sensors Principle, Mechanism, and Fabrication Technologies: A Comprehensive Review

Zinc oxide (ZnO) nanowires have been synthesized using thermal evaporation approach on quartz (SiO2) substrates in nitrogen atmosphere with a mixture of milled ZnO and graphite powder as reactants. Ohmic behavior has been obtained for both Ag and Au/Ag contact to ZnO nanowires. The samples were re-examined after annealing at 300degC, 400degC and 500degC. The optimum annealing temperature for obtaining minimum resistance of Ag and Au/Ag contact with ZnO nanowires are 400degC and 300degC respectively. The contact is dominated by Metal-Zinc bonds rather than Metal-Oxygen bonds which cause the formation of ohmic behavior.

Study of the contact properties of ZnO nanowires with Ag and Au/Ag

In this study, a three-way approach in designing a piezoelectrically actuated valveless micropump based on MEMS bulk micromachining fabrication process has been presented. The designed piezoelectrically actuated valveless micropump (PAVM) is analyzed using the fluid-structure interaction method to accurately predict the working behavior of the micropump based on the fluid, structural and piezoelectric equations. The fluid-structure dynamic effects should be taken into account in detail, since it is not enough to understand the intended functions individually due to the increasing demands for accuracy. In view of that, a coupled-field electro-mechanical-fluidic model of the PAVM has been simulated using MemFSI, a fluidstructure interaction (FSI) solver available in CoventorWare software package. Results obtained from the simulations are compared with analytical studies for verification purposes.

/pdf/design-simulations-of-mems-micropump-by-3d-fluid-structure-2oqs1tbb6k.pdf

Design Simulations of MEMS Micropump by 3D Fluid-Structure Interaction Analysis

In this paper we report an optimization of metal quality of planar MEMS electromagnetic coil through thermal annealing process. The study aims to see the effects of annealing process on the quality of metal layer deposited on localized p-type silicon regions. Two annealing process parameters namely isothermal (annealing under time variations in constant temperature) and isochronal (annealing under temperature variations at constant time) were performed on metal contact on highly doped Si substrate and characterized using transfer length method method by measuring the specific contact resistance źC of the metal traces. The measurement results showed that the annealing process have significant influence on physical and electrical characteristics of the metal layer. Analysis showed that the quality of metal layer was significantly improved through the annealing process after treatment at temperature variations between 425---550 °C. An optimum annealing at 525 °C for 15 min was observed and the contact resistance can be reduced significantly up to 400 %. The results also showed that the surface roughness improves while metal contact resistance decreases 40 times when the metal is annealed for more than 10 min. The planar coil structure was designed to reduce the device density of a compact magnetic micro-sensor system.

Enhancement of metal coil quality on selective p-silicon based planar electromagnetic coil by thermal annealing process

This report presented a 2D model for electroosmotic (EOF) aqueous fluid flow analysis along nanochannels connecting two reservoirs. The model uses the Navier-Stokes equations with electroosmotic velocity boundary condition at nanochannel wall. Zeta potential of the wall surface is varied and the influences on the velocity profile are observed for various channel height. Shear stress rate near the nanochannel entrance of different width has also been investigated. The magnitude velocity lies on the magnitude of zeta potential or the surface charge of the wall. The increased charged on the solid wall, also increased the velocity flow. The decreased height of channel helps to increase the flow velocity along it. The maximum and minimum flow velocities are recorded at channel height of 50nm and 250nm respectively with 35% difference. At all simulated channel height, the flow at the entrance of nanochannel is increased and formed a peak velocity but it will decrease and become uniform at the position far from the channel wall. The shear stress at the reservoir-nanochannel edge is increased with the decreased of channel height due to low aspect ratio of reservoir-channel dimension.

Effect of zeta potential variation in single phase flow characteristics of a rectangular nanochannel

The harmonic modes of movable proof-mass of differential capacitive accelerometer plays an important role in design. Another modes except main mode must be minimized to avoid uncertainty value of capacitance. In this paper, we tried to optimize the differential capacitive accelerometer using the variation of the length of finger attached at the proof mass. The length of finger varies from 40 /spl mu/m to 240 /spl mu/m with the variation of the width of proof-mass from 10 /spl mu/m to 40 /spl mu/m. The results have shown that the need to choose the length of finger for minimizing the effect of harmonic modes is as greater than 140 /spl mu/m assuming the external forces distributed in the interval of 0 to 1 MHz.

Burhanuddin Yeop Majlis

Papers

Study of the contact properties of ZnO nanowires with Ag and Au/Ag

Design Simulations of MEMS Micropump by 3D Fluid-Structure Interaction Analysis

Enhancement of metal coil quality on selective p-silicon based planar electromagnetic coil by thermal annealing process

Effect of zeta potential variation in single phase flow characteristics of a rectangular nanochannel

The optimization of mechanical harmonic modes of the 75 g balanced weight distribution capacitive accelerometer