No abstract

No abstract

KEY WORDScapacitive micromachined ultrasonic transducer, fabrication, image sensor, ultrasonography Capacitive micromachined ultrasonic tranducers (cMUTs) have recently emerged as an alternative to conventional piezoelectric transducers. They offer many advantages in terms of bandwidth, fabrication of layer arrays, efficiency, and sensitivity. This research presents the principles of operation, fabrication process steps, and application of the capacitive micromachined ultrasound transducer. The study also demonstrates in detail the collapse voltage design parameter of a cMUT membrane. Several important applications are presented to show the feasibility of using cMUTs which are demonstrated by imaging examples in immersion and air due to the cMUT capability of producing large bandwidth (123% fractional bandwidth) and lower impedance mismatch. Finally, the advantages of three-dimensional echographic images based on moving ultrasound linear array its technique are discussed in detail and compared with those of two-dimensional optical hand geometry. ª

Abstract. Mobile Ad Hoc Network (MANET) is a set of mobile nodes that communicate with each other to configure an immediate network without utilizing any of infrastructure, the centralized access point or centralized administration in multiple hop manner. There are a lot of routing protocols have been proposed in MANET which are different from each other in the performance and the mechanism. Therefore, the performance study of those protocols in different scenarios is needed. This paper presents the performance comparison between Dynamic Source Routing (DSR), Ad hoc on demand distance Vector Routing (AODV) as reactive routing protocols and Destination Sequenced Distance Vector (DSDV) as a proactive routing protocol to precisely determine which protocol is more effective. Network Simulator (NS) version 2.35 has used to simulate and evaluate the performance of these protocols in terms of the packet delivery ratio, average throughput, average end-to-end delay, and packet loss ratio with respect to the variable number of nodes.

An extensive review of optical fiber sensors and the most beneficial applications is presented in this chapter. Although electrical sensing technologies have been successfully deployed in countless applications, the introduction of optical sensing, engineers and scientists can now perform measurements that were previously impractical or, in some cases, impossible with conventional electrical sensors. At present, many real-world applications already use both approaches to combine both benefits. The inherent advantages of fiber optic sensors such as lightweight, small size, passive, low attenuation, immunity to electromagnetic interference (EMI), wide bandwidth and environmental ruggedness were heavily used to offset their major disadvantages of high cost. Thus Fiber optic sensors (FOSs) have boosted the utility and demand for optical sensors in various military, industry and social fields. FOSs show reliable and rigid sensing tasks over conventional electrical and electronic sensors.

No abstract

No abstract

No abstract