Hexagonal ferrites: A review of the synthesis, properties and applications of hexaferrite ceramics

In order to enable optical systems to operate with a high degree of compactness and reliability it is necessary to combine large number of optical functions in small monolithic structures. A development, somewhat reminiscent of that that took place in Integrated Electronics, is now beginning to take place in optics. The initial challenge in this emerging field, known appropriately as "Integrated Optics", is to demonstrate the possibility of performing basic optical functions such as light generation, coupling, modulation, and guiding in Integrated Optical configurations. The talk will review the main theoretical and experimental developments to date in Integrated Optics. Specific topics to be discussed include: Material considerations, guiding mechanisms, modulation, coupling and mode losses. The fabrication and applications of periodic thin film structures will be discussed.

Integrated optics

Electrophoretic deposition (EPD) is attracting increasing attention as an effective technique for the processing of biomaterials, specifically bioactive coatings and biomedical nanostructures. The well-known advantages of EPD for the production of a wide range of microstructures and nanostructures as well as unique and complex material combinations are being exploited, starting from well-dispersed suspensions of biomaterials in particulate form (microsized and nanoscale particles, nanotubes, nanoplatelets). EPD of biological entities such as enzymes, bacteria and cells is also being investigated. The review presents a comprehensive summary and discussion of relevant recent work on EPD describing the specific application of the technique in the processing of several biomaterials, focusing on (i) conventional bioactive (inorganic) coatings, e.g. hydroxyapatite or bioactive glass coatings on orthopaedic implants, and (ii) biomedical nanostructures, including biopolymer–ceramic nanocomposites, carbon nanotube coatings, tissue engineering scaffolds, deposition of proteins and other biological entities for sensors and advanced functional coatings. It is the intention to inform the reader on how EPD has become an important tool in advanced biomaterials processing, as a convenient alternative to conventional methods, and to present the potential of the technique to manipulate and control the deposition of a range of nanomaterials of interest in the biomedical and biotechnology fields.

https://royalsocietypublishing.org/doi/pdf/10.1098/rsif.2010.0156.focus

Electrophoretic deposition of biomaterials

With an ageing population, war, and sports related injuries there is an ever-expanding requirement for hard tissue replacement such as bone. Engineered artificial scaffold biomaterials with appropriate mechanical properties, surface chemistry and surface topography are in a great demand for enhancing cell attachment, cell growth and tissue formation at such defect sites. Most of these engineering techniques are aimed at mimicking the natural organization of the bone tissues and thereby create a conducive environment for bone regeneration. As the interaction between the cells and tissues with biomaterials at the tissue–implant interface is a surface phenomenon, surface properties play a major role in determining both the biological response to implants and the material response to the physiological condition. Hence surface engineering of biomaterials is aimed at modifying the material and biological responses through changes in surface properties while still maintaining the bulk mechanical properties of the implant. Therefore, there has been a great thrust towards development of Ca–P-based surface coatings on various metallic and nonmetallic substrates for load bearing implant applications such as hip joint prosthesis, knee joint prosthesis and dental implants. Typical coating methodologies like ion beam assisted deposition, plasma spray deposition, pulsed laser physical vapor deposition, magnetron sputtering, sol–gel derived coatings, electrodeposition, micro-arc oxidation and laser deposition are extensively studied at laboratory scale. In the present article, attempts are made to give an overview of the basic principles behind the coating techniques as well as advantageous features such as bioactivity and biocompatibility associated with these coatings. A strong emphasis will be given on laser-induced textured and bioactive coatings obtained by the author's research group [A. Kurella, N.B. Dahotre, Journal of Biomedical Applications 20 (2005) 5–50; A. Kurella, N.B. Dahotre, Acta Biomaterialia 2 (2006) 677–688; A. Kurella, N.B. Dahotre, Journal of Minerals, Metals and Materials Society (JOM) 58 (2006) 64–66; A. Kurella, N.B. Dahotre, Journal of Materials Science: Materials in Medicine 17 (2006) 565–572; P.G. Engleman, A. Kurella, A. Samant, C.A. Blue, N.B. Dahotre, Journal of Minerals, Metals and Materials Society (JOM) 57 (2005) 46–50; R. Singh, A. Kurella, N.B. Dahotre, Journal of Biomaterials Applications 21 (2006) 46–72; S.R. Paital, N.B. Dahotre, Biomedical Materials 2 (2007) 274–281; S.R. Paital, N.B. Dahotre, 2009, Acta Biomaterialia, doi:10.1016/j.actbio.2009.03.004 ; R. Singh, N.B. Dahotre, Journal of Materials Science: Materials in Medicine 18 (2007) 725–751.]. Since cells are sensitive to topographical features ranging from mesoscale to nanoscale, formation of these features by both pulsed and continuous wave Nd:YAG laser system will be highlighted. This can also be regarded as advancement towards third generation biomaterials which are bioinert, bioactive and which once implanted will stimulate cell adhesion, proliferation and growth at the interface. Further, an overview of various bio-implants and bio-devices and materials used for these kinds of devices, performance factors such as mechanical and corrosion behavior and surface science associated with these materials are also explained. As the present article is aimed at describing the multidisciplinary nature of this exciting field it also provides a common platform to understand this subject in a simple way for students, researchers, teachers and engineers in the fields ranging from medicine, dentistry, biology, materials science, biomedicine, biomechanics to physics.

Calcium phosphate coatings for bio-implant applications: Materials, performance factors, and methodologies

Friction stir welding/processing of metals and alloys: A comprehensive review on microstructural evolution

Superparamagnetic magnetite nanoparticles (MNP) of about 10 nm were designed with proper physico-chemical characteristics by an economic, biocompatible chemical coprecipitation of Fe2+ and Fe3+ in an ammonia solution, for hyperthermia applications. Synthetic methodology has been developed to get a well dispersed and homogeneous aqueous suspension of MNPs. Citric acid was used to stabilize the magnetite particle suspension, it was anchored on the surface of freshly prepared MNPs by direct addition method. Carboxylic acid terminal group not only render the particles more water dispersible but also provides a site for further surface modification. The naked MNPs are often insufficient for their stability, hydrophilicity and further functionalization. To overcome these limitations, citric acid was conjugated on the surface of the MNPs. The microstructure and morphology of the nanoparticles were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), and the interaction between citric acid and MNPs were characterized by Fourier transform infrared spectroscopy (FTIR), whereas the magnetic properties were investigated by vibrating sample magnetometry (VSM). Magnetic measurement revealed that the saturation magnetization of the nanoparticles was 74 emu/g and the nanoparticles were superparamagnetic at room temperature. We also have analyzed the potential of these particles for hyperthermia by determination of the specific absorption rate, the temperature increase (ΔT) of the particles was 37oC. These ferrofluids with high self-heating capacity are a promising candidate for cancer hyperthermia treatment.

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Citrate capped superparamagnetic iron oxide nanoparticles used for hyperthermia therapy

Packaging materials strongly affect the effectiveness of an electronic packaging system regarding reliability, design, and cost. In electronic systems, packaging materials may serve as electrical conductors or insulators, create structure and form, provide thermal paths, and protect the circuits from environmental factors, such as moisture, contamination, hostile chemicals, and radiation.Electronic Packaging Materials and Their Properties examines the array of packaging architecture, outlining the classification of materials and their use for various tasks requiring performance over time. Applications discussed include:interconnectionsprinted circuit boardssubstratesencapsulantsdielectricsdie attach materialselectrical contactsthermal materialssoldersElectronic Packaging Materials and Their Properties also reviews key electrical, thermal, thermomechanical, mechanical, chemical, and miscellaneous properties as well as their significance in electronic packaging.

Sirus Javadpour

Papers

Citrate capped superparamagnetic iron oxide nanoparticles used for hyperthermia therapy

Electronic Packaging Materials and Their Properties

Electrophoretic deposition of natural hydroxyapatite on medical grade 316L stainless steel

The effect of milling speed on the structural properties of mechanically alloyed Fe–45%Ni powders

Investigating the effect of holding duration on the microstructure of 1.2080 tool steel during the deep cryogenic heat treatment