Luminescent Ions in Advanced Composite Materials for Multifunctional Applications

From the Ground Up-Materials Science in Singapore.

Over the past few years, silicon micromachining has become a well-established technology. This development was promoted by the expectation that new types of sensors and actuators can be fabricated at low cost. Very early, attempts were made to realize acoustic sensors by the use of micromachining. Only now, the first commercial silicon microphones are available. This paper presents an overview of the technology and discusses different principles to build silicon microphones. There are acoustic sensors, e.g., the capacitive silicon microphone, which are designed by downscaling classical transducers. As opposed to this, there are new types of sensors, making use of novel transduction principles, or of the possibility to integrate active elements on the silicon substrate. The focus of this paper is on the following principles: the capacitive microphone in either single-chip or two-chip design, the piezoelectric microphone with organic or ceramic piezolayer, the piezoresistive microphone utilizing monocrystalline or polycrystalline silicon, the optical microphone based on modulating light propagation in a micromechanical waveguide, and the FET microphone, consisting of an acoustically modulated field-effect transistor. Each transducer will be discussed briefly, including the typical technological process necessary for its design.

This review article presents a comprehensive analysis of recent advancements in sound insulating materials, focusing on the characterization of material types and their properties from 2015 to 2024. It examined the application of various natural and synthetic materials, including fibrous, porous, composite, polymeric, and advanced materials, in architectural and environmental acoustics. A systematic search in the Scopus database identified relevant articles that were classified according to the material types and their inherent properties. The analysis covered key aspects such as thermal, mechanical, chemical, and physical characteristics, and their impact on sound insulation performance. Unlike previous studies that focused on classic materials or single aspects, this review used analytical and database tools to identify recent research trends. This review highlights the development of advanced and sustainable materials for noise reduction that address challenges in both building acoustics and environmental sound pollution.

From the Classical Scheme to Asmart/Functional Materials System: A Generic Transformation of Advanced Materials Technologies

New advanced composite materials have recently been of great interest. Especially, many researchers have studied on nano/micro composites based on matrix filled with nano-particles, nano-tubes, nano-wires and so forth, which have outstanding characteristics on thermal, electrical, optical, chemical and mechanical properties. Therefore, the need of numerical approach for design and development of the advanced materials has been recognized. In this paper, finite element analysis based on multi-resolution continuum theory is carried out to predict the anisotropic behavior of nano/micro composites based on damage mechanics with a cell modeling. The cell modeling systematically evaluates constitutive relationships from microstructure of the composite material. Effects of plastic anisotropy on deformation behavior and damage evolution of nano/micro composite are investigated by using Hill's 48 yield function and also compared with those obtained from Gurson-Tvergaard-Needleman isotropic damage model based on von Mises yield function.

An overview of the effect of stirrer design on the mechanical properties of Aluminium Alloy Matrix Composites fabricated by stir casting

This document has been prepared by the Professional Staff of High Technology Engineering Services, Inc. (HTES) for fiscal year (FY) 1993. Work was performed for various aspects of mechanical design and analysis, materials development and properties quantification, nuclear environment performance, and engineering program prioritization. The tasks enumerated in the subcontract, attachment B are: 1. Assist in preparation of final R&D report for SDC detector development. 2. Subcontractor shall make contributions to the development of innovative processes for the manufacture of quasi- isotropic, enhanced thermal conductivity compression molded advanced composite materials. 3. Perform finite element analysis as it relates to the Superconducting Super Collider Silicon Tracking System, both mechanical and thermal, of very thin section advanced composite materials. 4. Subcontractor shall perform technical studies, reviews, and assessments of the current program for advanced composites materials processing and testing. 5. Subcontractor shall attend meetings and discussions as directed by MEE-12 technical representative. Unfortunately during the course of FY93, technical and financial challenges prevailed against the aggressive goals set for the program. In point of fact, less than 25% of the contract value was able to be expended due to technical delays and programmatic funding cuts. Also, contracting difficulties with the SSC Lab and financial burdens at Los Alamos totally stopped progress on the subject subcontract during the whole of FY94. This was a great blow to me and the HTES, Inc. technical staff. Despite the negative influences over the years, significant progress was made in materials properties quantification and development of essential research and development documentation. The following brief report and attendant appendices will address these achievements.

A review of cost estimating for advanced composite materials applications

We present the architecture and design of a general purpose robotics development kit, called X10ABOT, which aims to facilitate the rapid development of robotic solutions to a wide variety of problems. Robotics kits of this sort are usually aimed at casual hobbyists and children, and as a result, usually have severe limitations in the number of sensors and actuators that they can manage. In contrast, X10ABOT is: modular (new functionality is added through standard daughter boards), scalable (up to 16 sensors and actuators on each of up to 112 hardware modules), and extensible (module software can be upgraded to support new types of sensors and actuators). We have also designed a generic port, capable of handling several types of sensors; and we have done similarly for the actuators. The system is still under active development, but we present preliminary results to show how the system would allow its user to readily add extra actuators to a creation, with minimal configuration information required, and relatively little impact on the preexisting user code.

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<div class="htmlview paragraph">Advanced materials including metal matrix, ceramic metal matrix and other composites/metals are critical to numerous applications associated with the development of next-generation aircraft architectures whose goal is to produce aerospace platforms that are more cost efficient, safe and reliable. The wide variety of advanced materials used in aerospace construction creates significant challenges for existing material characterization technologies. Photon Induced Positron Annihilation and related technologies are currently being used to assess fatigue, thermal degradation, creep, and embrittlement in aircraft components composed of advanced composite and metal alloy materials from initial manufacture through failure, thereby providing a new reliability assessment tool for pre- and post-mission component evaluations and likelihood-of-failure assessments.</div>

The interest in finding reliable and highly sensitive sensors for water quality control has grown recently empowered by the explosion of cutting-edge technologies such as nanotechnologies, optoelectronics, and computing on one hand and by the increasing need for more secure control of water quality on the other hand. This book highlights a number of modern topics in the field of biosensing particularly for water sensing in which the signal is enhanced, starting from surface enhanced spectroscopies using plasmonic structures such as Raman scattering (SERS), infrared enhanced absorption (SEIRA), and surface enhanced fluorescence (SEF). The SPR enhanced detection is highlighted in two chapters and addressed using signal processing and the use of color of solutions as a result of modification of the LSPR properties of nanoparticles. Porous materials are another field of research where the enhancement is achieved due to the increasing the area- to-volume ratio. Good examples are the two emerging fields of porous Si and sculptured thin films prepared by the oblique deposition technique. One of the long standing problems is bacteria detection in water which is addressed thoroughly with emphasis on the problems usually encountered in detecting large bioentities. Features: • Includes a wide selection of topics that can be adopted for advanced undergraduate and graduate courses in nanoscience and nanotechnology, biotechnology, materials science and engineering, physics, and chemistry unlike most specialized texts on nanoscience • Includes concentrated topics not existed in any other book such as enhanced signal detection in plasmonic sensors • Provides a unique multidisciplinary approach needed for the teaching of nanoscale science with the selection of authors from different disciplines.

Maintaining bone geometric and structural integrity is a necessity for normal mobility. After fracture, bone disease or other conditions resulting in skeletal loss or compromise, porous materials offer the possibility for near faultless replacement of the normal bone material. Ceramics, and to a lesser extent, metals, are the predominant porous materials currently used in bone engineering. This latter term is used as a blanket term for orthodontics, orthopedics and related fields in which the replacement of bone is either required or selectively chosen. Because bone is a porous material, there is a physiological rationale for the use of porous materials in its replacement. Moreover, porous bone implant material is advantageous for the early incorporation of the implant into or apposed to the bony tissue surrounding it. There is, however, a difference in the size and extent of the bone and implant porosities for optimal bone incorporation of the material. This review intends to clarify both the nature of and reason for this difference. Accordingly, a review of the principal types of porous materials (organics, ceramics, metals, metallorganics and organoapatites and composites) used in bone engineering will be provided. This will springboard a consideration of the important engineering considerations of material property matching, machining and forming, corrosion and biocompatibility, fatigue and lifecycle, coating, and interfacial properties. The importance of matching the porous material to the particular bone engineering application will then be discussed. In providing this review, the authors hope to bring an appreciation of the complexity of the field to the fore, while also demonstrating how much has already been accomplished due to the efforts of many research groups. The ultimate porous bone implant, perhaps, is yet to be designed; however, there is reason to believe that such a material is not long in coming. We hope to demonstrate some possible pathways to this material. Outline The paper is constructed as follows.

This paper presents an overview of ISIS Canada's development and application of fiber optic sensing systems in a variety of civil infrastructure projects. Three types of fiber optic sensors have been utilized in ISIS projects-to-date: fiber Bragg gratings (FBGs), Fabry-Perot sensors, based on measuring displacement between two fibers; and a new sensor called a `long gauge (LG)', which employs a low coherence interferometry technique to measure deformations over gauge lengths ranging from 10 cm to 40 m. Details on the operation of the LG system are described below. Applications of the FBG and LG sensors are given for several ISIS projects that also involved the rehabilitation and strengthening of concrete structures using advanced composite materials.

Charge density (CD) studies by Maximum Entropy Method (MEM) (Sakata & Sato, 1990) from x-ray diffraction data have been widely applied to solve problems and questions in materials science during past two decades. Encapsulations of metal atoms (Takata et al, 1995), gas molecules, as well as protein molecules in the materials have been visualized as MEM CDs. The MEM CD technique is now regarded as a sophisticated technique for visualization in atomic scale. Electrostatic potential (EP) and electric field (EF) from x-ray diffraction data using MEM have been developed in 2006 (Tanaka et al, 2006). The EP & EF successfully applied to ferroelectric material PbTiO3 and a charge ordered manganite system. The method has huge potential in materials science since interaction in the non-atomic region can be visualized experimentally. One of the promising target for EP & EF analysis is host-guest systems, such as porous coordination polymers (PCPs), zeolites, clathrates as well as endohedral metallofullerenes[3]. In the case of host-guest systems, the guest atom(s) or molecule(s) are located in spatially wider sites in comparison to other type of materials. Therefore the detailed structural information in the spatially wider sites is one of the most important issues. In the present study, I present an application of MEM EP & EF analysis to host-guest related system, icosahedral B12 cluster materials and hydrogen adsorbed PCP. The EP studies clearly visualize doping sites in B12 based superconductor and adsorption sites in PCP. The EF enables us to estimate quantitative interaction from host to guest. The quantitative evaluation really bridges between experiment and theory in materials science.