Advanced Materials Research Research Articles

Electrical Characterization of Al/Ta2O5/Al Structures Grown by Electron Beam Deposition

Electrical Characterization of Al/Ta2O5/Al Structures Grown by Electron Beam Deposition I.S. Yahiaa,b,∗ and A.A.M. Farag Department of Physics, Center of Excellent for Advanced Materials Research, Faculty of Science, King Khalid University, P.O. Box 9004, Abha, Saudi Arabia Nano-Science&Semiconductor Labs., Physics Department, Faculty of Education, Ain Shams University Roxy, Cairo, Egypt Thin Film Laboratory, Department of Physics, Faculty of Education, Ain Shams University, Roxy, Cairo, Egypt

Novel nano-rough polymers for cartilage tissue engineering

This study presents an innovative method for creating a highly porous surface with nanoscale roughness on biologically relevant polymers, specifically polyurethane (PU) and polycaprolactone (PCL). Nanoembossed polyurethane (NPU) and nanoembossed polycaprolactone (NPCL) were produced by the casting of PU and PCL over a plasma-deposited, spiky nanofeatured crystalline titanium (Ti) surface. The variables used in the process of making the spiky Ti surface can be altered to change the physical properties of the spiky particles, and thus, the cast polymer substrate surface can be altered. The spiky Ti surface is reusable to produce additional nanopolymer castings. In this study, control plain PU and PCL polymers were produced by casting the polymers over a plain Ti surface (without spikes). All polymer surface morphologies were characterized using both scanning electron microscopy and atomic force microscopy, and their surface energies were measured using liquid contact angle measurements. The results revealed that both NPU and NPCL possessed a higher degree of nanometer surface roughness and higher surface energy compared with their respective unaltered polymers. Further, an in vitro study was carried out to determine chondrocyte (cartilage-producing cells) functions on NPU and NPCL compared with on control plain polymers. Results of this study provided evidence of increased chondrocyte numbers on NPU and NPCL compared with their respective plain polymers after periods of up to 7 days. Moreover, the results provide evidence of greater intracellular protein production and collagen secretion by chondrocytes cultured on NPU and NPCL compared with control plain polymers. In summary, the present in vitro results of increased chondrocyte functions on NPU and NPCL suggest these materials may be suitable for numerous polymer-based cartilage tissue-engineering applications and, thus, deserve further investigation.

Materials and surface engineering to control bacterial adhesion and biofilm formation: A review of recent advances

Bacterial adhesion to surfaces and subsequent biofilm formation are a leading cause of chronic infections and biofouling. These processes are highly sensitive to environmental factors and present a challenge to research using traditional approaches with uncontrolled surfaces. Recent advances in materials research and surface engineering have brought exciting opportunities to pattern bacterial cell clusters and to obtain synthetic biofilms with well-controlled cell density and morphology of cell clusters. In this article, we will review the recent achievements in this field and comment on the future directions.

Theoretical Analysis and Computational Simulation of Advanced Structured Materials

Structured materials may be broadly classified as comprising a single phase with an underlying topology ormultiple phases in a mixture [1]. Examples include porous materials [2–5], multilayers [6, 7], and functionally graded [7–9] and composite materials [10]. Structures can vary in size, typically from macro[2] down to meso-, micro-, and nanoscales [3, 11–13], and may also be hierarchical [12, 13]. Some structured materials comprise both topology and multiple phase mixtures at different length scales [3, 10], for example, metal matrix composite foams. In all cases, advanced structured materials are designed to have exceptional properties [7–9, 12, 13] that cannot be achieved by conventional materials, for example, very high toughness, specific stiffness, multifunction [3, 4], and so forth. The knowledge and understanding of these supermaterials rely not only on advanced characterization and processing techniques, but also on progress in theoretical analyses and computational simulations. Experimentalmeasurements are truly important in developing, characterizing, and understanding advanced materials. However, they are usually very expensive and time consuming. As the material properties and performance usually depend on the interplay of many parameters and factors, it is quite difficult to understand how each of them affects the properties and performance and which one is most important. Consequently, it is difficult to obtain the global picture about how each of the parameters and factors affects the material performance only from experimental measurements.With the advancement of computer hardware and computational software, simulations (i.e., numerical experiments) play an increasingly important role in scientific research of advanced materials and structures. Compared to real experimental measurements, computer simulations are not only faster, but also more economic. Moreover, computer simulations could help us understand in detail how each of the parameters and factors affects the properties and performance of advanced materials and hence which of these are most important. The same applies to the design of advanced materials. For example, theoretical analyses and computational simulations could guide the design of mechanical and geometrical properties of nanostructured hierarchical honeycombs and open-cell foams so that they are size dependent, tunable, and controllable [3, 12, 13]. Multilayer materials [6–9] can be designed to have extremely good thermal resistance, in addition to goodmechanical strength, stiffness, and ductility. It may also be possible to design and synthesize biological materials that have mechanical properties similar to those of natural materials [5, 10]. This special issue focuses mainly on theoretical analyses and computational simulations of advanced structuredmaterials including high-performance cements, shape memory alloys, nanostructured composites, and multilayered materials.Wehope that readerswill find in this special issue not only accurate data/results and up-to-date reviews on the relevant research areas, but also useful guidance on important areas for further research work.

Short communication: selective cytotoxicity of curcumin on osteosarcoma cells compared to healthy osteoblasts

Curcumin is a natural phenolic compound extracted from the plant Curcuma longa L. In previous studies, curcumin has been shown to have anticancer, antioxidant, and anti-inflammatory effects. In this study, the cytotoxicity of different concentrations (5, 10, 25, 50, 75, and 100 μM) of curcumin dissolved in dimethyl sulfoxide was compared between MG-63 osteosarcoma and healthy human osteoblast cells. Consequently, the viability of osteosarcoma cells was less than 50% at a concentration of 10 μM compared to the control sample without curcumin, but healthy osteoblast cells had at least 80% viability throughout all the concentrations tested. The results demonstrated that MG-63 osteosarcoma cells were much more sensitive in terms of cytotoxicity to curcumin, while the healthy human osteoblasts exhibited a higher healthy viability after 24 hours of curcumin treatment. Therefore, this study showed that at the right concentrations (5 μM to 25 μM), curcumin, along with a proper nanoparticle drug delivery carrier, may selectively kill bone cancer cells over healthy bone cells.

Showcase for advanced materials research in the UK

Showcase for advanced materials research in the UK

Advanced Materials World Congress, Turkey

We are glad to organise Advanced Materials Word Congress (AMWC, http://www.amwc2013.org/) together with the International Association of Advanced Materials (www.iaamonline.org) and hosted by the Ä°zmir Institute of Technology in the beautiful coastal town ÇeÅŸme, Turkey at Altinyunus Hotel ÇeÅŸme during 16-19 September, 2013. The goal of congress is to provide a global platform for researchers and engineers coming from academia and industry to present their research results and activities in the field of materials science and engineering with a special attention on interdisciplinary research of advanced materials. The conference will provide opportunities for the delegates to exchange their face-to-face novel ideas and experiences with the international experts during plenary & invited talks, oral presentations and poster sessions. We will set up ten sessions with keynote forum, panel discussion and project negotiation. The full article of presentations will be published in the special issue of Advanced Materials Letters.

A Bibliometric Analysis of the Performance of Advanced Materials Research from 2005 to 2012

This paper presents a detailed chronological survey of paper published in the journal titledAdvanced Materials Researchfrom 2005 to 2012. An analysis of the research performance according to publication output, country, institute, classification code and controlled vocabulary used. Results showed that China published about 85% of total publications, and School Of Mechanical Engineering And Automation, Northeastern University was the most productive institute. In addition, results also showed that manufacture, building materials, design, civil engineering and construction equipment were the most frequently used controlled vocabularies

Adjusting the Electronic and Optical Properties of Mesoporous MCM-41 Materials by Ti Doping

The objectives of this thesis are to understand the electronic structures of oxides and oxynitrides for photocatalytic water splitting, examine the Casimir interaction between oxides, and explore possible approach to bridge the Casimir force and material properties for advanced material research. The studies were performed in the framework of the density functional theory, many-body perturbation theory, i.e, the GW approximation and Bethe-Salpeter equation, as well as the Casimir-Lifshitz approach.The thesis consists of two sets of results. In the first part (papers I-VI), the electronic structures of oxynitrides, i.e., ZnO-GaN and ZnO-InN, with different compositions and local structures have been studied. The oxynitrides reduce the band-gap energies significantly compared to the binary counterparts, enabling the oxynitrides to act as visible light active photocatalysts. Formation of cluster--like structures further reduces the band-gap and delocalizes the valence bands, benefiting higher optical absorption. Furthermore, the energy levels between oxynitride and water were aligned using a surface model adapted from semiconductor heterostructure.In the second part (papers V-IX), the electronic structures of oxides as well as the Casimir interactions have been examined. In particular, we investigated the differences of optical and electronic properties between SnO2 and TiO2 polymorphs in terms of band-edge characters and electron-phonon coupling. In addition, we synthesized a mesoporous material possessing two types of pore structures (one is hexagonal ordered with pore diameter of 2.60 nm and the other is disordered with pore diameter of 3.85 nm). The pore framework contains four-coordinated titanium and oxygen vacancies, verified by both experimental measurements and density-functional theory calculations. Utilizing the predicted properties of the materials, we studied the Casimir interactions. A stable equilibrium of Casimir force is achieved in planar geometry containing a thin film and porous substrates. Both the force and equilibrium distance are tuned through modification of the material properties, for instance, optical properties and porosity. Furthermore, we adapted this concept to study the interactions between gas bubbles and porous SiO2 in water. A transition from repulsion to attraction is predicted, which highlights that the bubbles may interact differently at different surface regions.

Microstructural Characterization and Hardness Evaluation of Friction Stir Welded Composite AA6061-4.5Cu-5SiC (Wt.%)

Recent developments in advanced materials research have led to the emergence of new materials having features like low density, high strength to weight ratio, excellent mechanical properties, heat and corrosion resistance. In friction stir welding (FSW), a non-consumable rotating welding tool is used to generate the frictional heat and plastic deformation of the material in the welding zone, which is in the solid state. The advantages of FSW as compared to the fusion welding are high joint strength, less defect weld, uniform distribution of grain structure in the weld zone and low power consumption. AA6061with 4.5 % weight of copper and 5 % weight of SiC composite material has been prepared to conduct experiment and carry out characterization, evaluation of the mechanical properties. Micro-structural characterization of the weld zone is carried out by scanning electron microscope (SEM). Evaluation of hardness was also carried out across the weld zone. A successful method for FSW of AA6061-4.5(wt.%) Cu-5(wt.%) SiC has been developed. Defence Science Journal, 2013, 63(4), pp.429 -434 , DOI:http://dx.doi.org/10.14429/dsj.63.4869

Comparison between an Advanced Numerical Simulation of Sheet Incremental Forming Using Adaptive Remeshing and Experimental Results

Recently, new sheet metal forming technique, incremental forming has been introduced. It is based on using a single spherical tool, which is moved along CNC controlled tool path. During the incremental forming process, the sheet blank is fixed in sheet holder. The tool follows a certain tool path and progressively deforms the sheet. Nowadays, numerical simulations of metal forming are widely used by industry to predict the geometry of the part, stresses and strain during the forming process. Because incremental forming is a dieless process, it is perfectly suited for prototyping and small volume production [1, 2]. On the other hand, this process is very slow and therefore it can only be used when a slow series production is required. As the sheet incremental forming process is an emerging process which has a high industrial interest, scientific efforts are required in order to optimize the process and to increase the knowledge of this process through experimental studies and the development of accurate simulation models. In this paper, a comparison between numerical simulation and experimental results is realized in order to assess the suitability of the numerical model. The experimental investigation is realized using a three-axis CNC milling machine. The forming tool consists in a cylindrical rotating punch with a hemispherical head. A subroutine has been developed to describe the tool path from CAM procedure. A numerical model has been developed to simulate the sheet incremental forming process. The finite element code Abaqus explicit has been used. The simulation of the incremental forming process stays a complex task and the computation time is often prohibitive for many reasons. During this simulation, the blank is deformed by a sequence of small increments that requires many numerical increments to be performed. Moreover, the size of the tool diameter is generally very small compared to the size of the metal sheet and thus the contact zone between the tool and the sheet is limited. As the tool deforms almost every part of the sheet, small elements are required everywhere in the sheet resulting in a very high computation time. In this paper, an adaptive remeshing method has been used to simulate the incremental forming process. This strategy, based on adaptive refinement and coarsening procedures avoids having an initially fine mesh, resulting in an enormous computing time. Experiments have been carried out using aluminum alloy sheets. The final geometrical shape and the thickness profile have been measured and compared with the numerical results. These measurements have allowed validating the proposed numerical model.

Advanced Materials World Congress (AMWC)

We are glad to announce Advanced Materials Word Congress (AMWC, http://www.amwc2013.org/) together with the International Association of Advanced Materials (www.iaamonline.org) and hosted by the Ä°zmir Institute of Technology in the beautiful coastal town ÇeÅŸme, Turkey at Altinyunus Hotel ÇeÅŸme during 16-19 September, 2013. The goal of congress is to provide a global platform for researchers and engineers coming from academia and industry to present their research results and activities in the field of materials science and engineering with a special attention on interdisciplinary research of advanced materials. The conference will provide opportunities for the delegates to exchange their face-to-face novel ideas and experiences with the international experts during plenary & invited talks, oral presentations and poster sessions. We will set up ten sessions with keynote forum, panel discussion and project negotiation. The full article of presentations will be published in the special issue of Advanced Materials Letters.

Nanorods of Cobalt Oxide: Study on its Morphology with Varied Sonication Time

Nanomaterials research has become a major attraction in the field of advanced materials research in the area of Physics, Chemistry, and Materials Science. Biocompatible and chemically stable magnetic metal oxide nanoparticles have biomedical applications that includes drug delivery, cell and DNA separation, gene cloning, magnetic resonance imaging (MRI). This research is aimed at the fabrication of magnetic cobalt oxide nanoparticles using a safe, cost effective, and easy to handle technique that is capable of producing nanoparticles free of any contamination. Nanostructured Cobalt oxide powder was prepared by sonication method using ultrasonicator. Effect of sonication for different time intervals, on the morphology of cobalt oxide nanostructures was extensively studied. The morphology of the nanorods were very much affected by the sonication time, it was found that with an increase in sonication time, the length of the nanorods seem to considerably increase at the same time an agglomeration effect comes in to action and the rods form bundle like structures. These cobalt oxide nanorods were characterized using X-ray Diffraction characterization (XRD) and it revealed a cubic structure. Weight percentage of cobalt oxide was confirmed by thermo gravimetric analysis (TGA).

Hydrothermal evolution, optical and electrochemical properties of hierarchical porous hematite nanoarchitectures.

Hollow or porous hematite (α-Fe2O3) nanoarchitectures have emerged as promising crystals in the advanced materials research. In this contribution, hierarchical mesoporous α-Fe2O3 nanoarchitectures with a pod-like shape were synthesized via a room-temperature coprecipitation of FeCl3 and NaOH solutions, followed by a mild hydrothermal treatment (120°C to 210°C, 12.0 h). A formation mechanism based on the hydrothermal evolution was proposed. β-FeOOH fibrils were assembled by the reaction-limited aggregation first, subsequent and in situ conversion led to compact pod-like α-Fe2O3 nanoarchitectures, and finally high-temperature, long-time hydrothermal treatment caused loose pod-like α-Fe2O3 nanoarchitectures via the Ostwald ripening. The as-synthesized α-Fe2O3 nanoarchitectures exhibit good absorbance within visible regions and also exhibit an improved performance for Li-ion storage with good rate performance, which can be attributed to the porous nature of Fe2O3 nanoarchitectures. This provides a facile, environmentally benign, and low-cost synthesis strategy for α-Fe2O3 crystal growth, indicating the as-prepared α-Fe2O3 nanoarchitectures as potential advanced functional materials for energy storage, gas sensors, photoelectrochemical water splitting, and water treatment.

Nonwetting “white graphene” films

Nonwetting (superhydrophobicity) is currently of great interest in advanced materials research for self-cleaning applications, although it has been a well-known phenomenon in nature (e.g. in lotus leaves) for a long time. Aiming at widening the potential applications of synthetic superhydrophobic films, we have used a noncatalytic chemical vapor deposition method to prepare superhydrophobic films consisting of boron nitride (BN) nanosheets, also known as “white graphenes”. A mixture of boron (B) and boron trioxide (B2O3) powder was used as a new precursor to grow such nano-rough films. The peculiar surface topography of the films induced a nonwetting behavior which was manifested by the picking up of external particles through water droplets rolling on their surface. The nonwetting tendency of the films is explained based on the interactions of the dipole moments of polar water molecules and BN nanosheets.

Trends in Patents of Enzymatic Biomarkers for Early Detection of Bacteria

Delayed or improper diagnosis of bacterial infection can result in sepsis, serious, and often deadly or inflammatory response. Thus, there is a need for a simple assay that can detect low levels of bacteria, which are faster and sensitive in order to provide data for establish treatment decisions in a clinically relevant time frame. Advances in materials research and molecular biology play an important role in understand and development the best way for bacterial diagnosis kits and methods to reach specific targets from the cellular metabolism such as particular enzymes. Recent changes in the diagnostic methods are using simple techniques especially focus to distinguish enzymatic reactions, dependent on substrate and biochemical allowing the bacteria presence detection by very fast reactions. This review highlights the state-ofart in patents of enzymatic biomarkers for early detection of bacteria based-on nanostructures chromogenic or fluorogenic. Keywords: Bacteria, chromogenic, diagnosis, early detection, enzymatic biomarkers, fluorogenic, Nanostructures, nanodevices, Enzyme-substrates, Coumarin derivatives

Trends in Patents of Enzymatic Biomarkers for Early Detection of Bacteria

Delayed or improper diagnosis of bacterial infection can result in sepsis, serious, and often deadly or inflammatory response. Thus, there is a need for a simple assay that can detect low levels of bacteria, which are faster and sensitive in order to provide data for establish treatment decisions in a clinically relevant time frame. Advances in materials research and molecular biology play an important role in understand and development the best way for bacterial diagnosis kits and methods to reach specific targets from the cellular metabolism such as particular enzymes. Recent changes in the diagnostic methods are using simple techniques especially focus to distinguish enzymatic reactions, dependent on substrate and biochemical allowing the bacteria presence detection by very fast reactions. This review highlights the state-ofart in patents of enzymatic biomarkers for early detection of bacteria based-on nanostructures chromogenic or fluorogenic. Keywords: Bacteria, chromogenic, diagnosis, early detection, enzymatic biomarkers, fluorogenic, Nanostructures, nanodevices, Enzyme-substrates, Coumarin derivatives

The influence of smoke on the THz imaging

The influence of smoke on THz imaging was examined. We tested experimentally a passive THz camera - TS4 from ThruVision Systems Ltd. The camera detects natural human radiation at a frequency of 0.25THz. The distance camera-target could be 3-15 meters. Moreover, Time Domain Spectroscopy was used to investigate the influence of the amount of smoke on transmission in the (0.1 ÷ 2.5)THz range. Full Text: PDF References H. Zhao, Advanced Materials Research 490-495 (2012). CrossRef L. Yun-Shik, Principles of Terahertz Science and Technology (Springer 2008).CrossRef M. Sypek, M. Makowski, E. Hérault, A. Siemion, A. Siemion, J. Suszek, F. Garet, J.L. Coutaz, "Highly efficient broadband double-sided Fresnel lens for THz range", Optics Letters 37 (12) (2012) CrossRef N. Palka, "THz Reflection Spectroscopy of Explosives Measured by Time Domain Spectroscopy", Acta Physica Polonica A 120 (4) (2011). CrossRef N. Palka, M. Szustakowski, T. Trzcinski, M. Mozdzonek, Photonics Letters of Poland 3 (2) (2011). CrossRef ThruVision System Ltd., website: http://www.truvision.com Teraview Ltd., website: http://www.teraview.com

ChemInform Abstract: Isolation and Structure Determination of Three New Sesquiterpenoids from Achillea millefolium.

Umar Farooqa, Afsar Khana, Saleha Suleman Khanb, Shazia Iqbalc, Rizwana Sarwara, Sher Bahadar Khand, and Viqar Uddin Ahmadd a Department of Chemistry, COMSATS Institute of Information Technology, Abbottabad-22060, Pakistan b H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan c Department of Chemistry, Kohat University of Science and Technology, Kohat-26000, Pakistan d Center of Excellence for Advanced Materials Research and Chemistry Department, Faculty of Science, King Abdulaziz University, P. O. Box 80203, Jeddah 21589, Saudi Arabia

Antiferroquadrupole order and magnetic field induced octupole in CeB6

Takeshi Matsumura,1,2,* Takumi Yonemura,1 Keisuke Kunimori,1 Masafumi Sera,1,2 Fumitoshi Iga,3 Tatsuya Nagao,4 and Jun-ichi Igarashi3 1Department of Quantum Matter, AdSM, Hiroshima University, Higashi-Hiroshima 739-8530, Japan 2Institute for Advanced Materials Research, Hiroshima University, Higashi-Hiroshima 739-8530, Japan 3Faculty of Science, Ibaraki University, Mito, Ibaraki 310-8512, Japan 4Faculty of Engineering, Gunma University, Kiryu, Gunma 376-8515, Japan (Received 1 February 2012; revised manuscript received 1 May 2012; published 14 May 2012)