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

Deep cryogenic heat treatment is assumed as a supplementary heat treatment performed on steels before the final tempering treatment to enhance the wear resistance and hardness of the steels. In this study, the effects of the deep cryogenic heat treatment on the wear behavior and corrosion resistance of the 1.2080 tool steel were studied using the wear testing machine and polarization and impedance spectroscopy tests. Moreover, the microstructural changes of the deep cryogenically treated samples were clarified via the scanning electron microscope (SEM) and X-ray diffraction testing machine. The results showed that the deep cryogenic heat treatment eliminated the retained austenite and made a more uniform carbide distribution with higher percentages. Beyond this, it was clarified that the deep cryogenic heat treatment increased the hardness and improved the wear behavior of the 1.2080 tool steel, as well as decreasing the corrosion resistance, due to the higher chromium carbides produced during the deep cryogenic heat treatment.

http://journal.issiran.com/article_18526_40405ef35d963ca17d3fa6d1d7c668dc.pdf

Investigating the Effect of the Deep Cryogenic Heat Treatment on the Mechanical Properties and Corrosion Behavior of 1.2080 Tool Steel

In this work, the microwave assisted aluminothermic reduction of molybdenite (MoS2) was first demonstrated, and then the reaction was optimized using different processing parameters. A self-sustainable combustion front was readily induced in a compressed stoichiometric mixture of MoS2 and Al using microwave ignition. However, the reduction reaction (3MoS2 + 4Al = 3Mo + 2Al2S3) could not be fully completed mainly due to the rapid progress of the combustion front and insufficient available Al to fully reduce MoS2. A leaching process in HCl was also adapted to remove the Al2S3 byproduct and unreacted aluminum. Moreover, the effect of compaction pressure, excess Al and mechanical activation was further investigated to optimize the aluminothermic reduction reaction. Adding excess Al over the stoichiometric ratio shifted the reaction toward producing more Mo metal with lower retained MoS2. While the effect of compaction pressure on the reaction products was found to be negligible, it could affect the ignition temperature and the propagation rate of the combustion front. Mechanical activation had two crucial effects on the aluminothermic reduction of MoS2: decreasing the ignition temperature and increasing the reaction progression. A mechanically activated MoS2/Al powder mixture, which was prepared by 30 min ball milling with 0.5 mol excess Al and compressed at 70 MPa, exhibited the best overall efficiency for aluminothermic reduction of MoS2 to produce Mo metal. 

Effect of processing parameters on the microwave assisted aluminothermic reduction of molybdenite

Purpose: Magnetic hyperthermia is a treatment method based on eddy currents, hysteresis, and relaxation mechanisms of magnetic nanoparticles (MNPs). MNPs such as Fe3 O4 have the ability to generate heat under an alternating magnetic field. Heat sensitive liposomes (Lip) convert from lipid layer to liquid layer through heat generated by MNPs and can release drugs. Methods: In this study, different groups of doxorubicin (DOX), MNPs and liposomes were evaluated. The MNPs were synthesized by co-precipitation method. The MNPs, DOX and a combination of MNPs and DOX were efficiently loaded into the liposomes using the evaporator rotary technique. Magnetic properties, microstructure, specific absorption rate (SAR), zeta potential, loading percentage of the MNPs and DOX concentration in liposomes, in vitro drug release of liposomes were studied. Finally, the necrosis percentage of cancer cells in C57BL/6J mice bearing melanoma tumors was assessed for all groups. Results: The loading percentages of MNPs and concentration of DOX in the liposomes were 18.52 and 65% respectively. The Lip-DOX-MNPs at the buffer citrate solution, showed highly SAR as the solution temperature reached 42°C in 5 minutes. The release of DOX occurred in a pH-dependent manner. The volume of tumor in the therapeutic groups containing the MNPs significantly decreased compared to the others. Numerical analysis showed that the tumor volume in mice receiving Lip-MNPs-DOX was 9.29% that of the control and a histological examination of the tumor section showed 70% necrosis. Conclusion: The Lip-DOX-MNPs could be effective agents which reduce malignant skin tumors growth and increase cancer cell necrosis.

/pdf/liposome-fe3-o4-doxorubicin-mediated-treatment-of-melanoma-2lx6b6o2.pdf

Liposome-Fe3 O4-Doxorubicin Mediated Treatment of Melanoma Tumors

/pdf/cationic-albumin-modified-magnetite-nanoparticles-for-1779zkn21e.pdf

Cationic albumin modified magnetite nanoparticles for localized delivery of sodium methotrexate

http://scientiairanica.sharif.edu/article_21665_62d493413ca56ee3e24709ccc626f8e1.pdf

Sirus Javadpour

Papers

Investigating the Effect of the Deep Cryogenic Heat Treatment on the Mechanical Properties and Corrosion Behavior of 1.2080 Tool Steel

Effect of processing parameters on the microwave assisted aluminothermic reduction of molybdenite

Liposome-Fe3 O4-Doxorubicin Mediated Treatment of Melanoma Tumors

Cationic albumin modified magnetite nanoparticles for localized delivery of sodium methotrexate

Modeling the CO gas response of PEDOT:PSS/Fe(salen) thin film for a gas sensor