1Mechanical Design and Materials Department, Faculty of Energy Engineering, Aswan University, Egypt
2Department of Mechanical Engineering, College of Engineering, University of Sharjah, UAE
Cost-effective and highly active electro catalysts for alcohols electro oxidation reaction are of great importance in order to widespread the commercial feasibility of fuel cell technology. However, the commercial validity of alcohols fuel cells is significantly hindered owing to the high cost of the noble metal catalysts and concurrent activity degradation. Herein, were report the design of nitrogen doped nickel oxide-porous carbon hybrid as a potential solution to this long standing issue. The embedding of conductive carbon dots into the hierarchal nano architecture is expected to play the decisive role in promoting the electro catalytic performance towards methanol and glycerol electro oxidation and enable better utilization exposed electroactive sites. As a result, the synthesized hybrid show exceptional activity for both methanol and glycerol oxidation reaction due to the synergy of Ni3+/Ni2+ active sites and carbon dots as over 80,000 s which is largely attributed to the strong mutual interactions of well as nitrogen species. In addition, the hybrid reveals remarkable durability under periodic reactivation components leading to fast electrocatalysis and unprecedented durability for methanol oxidation reaction (MOR).
Biography:
Prof. Khalil is currently working as a professor and head of the Mechanical Engineering Department at the University of Sharjah. After graduating from Minia University, Faculty of Engineering, in 1990, he worked for three years in Sugar and Integrated Industries Company (SIIC) as a planning and follows up engineer. In July, 1995, he moved from SIIC to work as a demonstrator in Faculty of Energy Engineering, Aswan University, Egypt. In 1996 he completed his Master Degree. In 1998 he was accepted into the Trans-Century Training Program for Talents by the Ministry of Education of China and the Ministry of Higher Education of Egypt as a scholarship student to complete his Ph. D degree. He earned PhD in 2002. He was promoted to Assistant Professor in 2002. He got an opportunity for Postdoc fellowship in Chonbuk National University (CBNU), South Korea from 2004-2005. He was later selected through the Long-Term Foreign Faculty Program for another 2 years in the same University. In 2008, he has been appointed as Associate Professor in Faculty of Engineering, King Saud University. He has published more than 100 ISI papers of international standard with high impact factor in addition to 3 patent and two book chapters. He is also running more than five funded projects. He has promoted to the rank of full professor in both Saudi Arabia and Egypt in 2011.
University Clermont Auvergne, institut Pascal, France
Thanks to its biodegradability and biocompatibility, chitosan (CS) has great potential to be used in bone tissue engineering and drug delivery. Nevertheless, scaffolds made of CS, must be porous to be used in these biomedical applications. Pore size and interconnectivity between pores have an influence on the foam properties like mechanical strength and cell adhesion. However, when foaming occurs in batch, as the gas comes from the sky of the vessel the control of the density and the pore size distribution will be difficult. The present work aims to study the foaming ability of CS solution alone and with hydroxyapatite (Hap)/ Tetraethylorthosilicate (TEOS) under steady state flow conditions.
A jacketed Narrow Annular Gap Unit (NAGU) system was used for continuous foaming study. CS mixtures and gas were introduced at the bottom of the unit. Mixture flow rate was maintained at 30 ml/min. To obtain foam with different density, gas flow rate was changed from 10 to 70 mL/min. Temperature was maintained constant by the circulation of glycol solution in the jacketed unit. Foaming experiments were carried out using a CS solution and Tween 20 as foaming agent. The experiments were investigated with CS alone or in the presence of Hap and/or TEOS as source of calcium and silice respectively. The influence of operating conditions: gas/liquid flow rates, rotation speed on the density and porosity of final material were studied. The aim is to afford a sample process permitting to obtain reproducible biomaterial with a desired porosity and density for bone and tissular regeneration. Samples were collected for foams analysis (density, bubbles sizes distribution) and freeze dried for mechanical and porosity analysis (DMA, SEM). It was shown that continuous foaming process could be efficiently used to generate new biomaterial with controlled density/porosity as ceramic-like foam.
Biography:
Doctor Cédric DELATTRE is an associate professor in Biochemistry at Institut Pascal UMR CNRS 6602, France since 2012. He built his experience in biochemistry both in international academic institution (Picardie Jules Verne University, France; Vellore Institute of Technology, India) and industrial Setting (Greentech, France). His expertise areas include chemical/synthetic biochemistry, poly- and oligosaccharides biochemistry, enzymology technologies (development of immobilized enzyme for industrial reactor), functional biomaterial including design and development of bioactive polysaccharides, biorefinery, green chemistry. He is author of 62 scientific papers in international peer-reviewed journals, 5 book chapters, 9 international patents, 41 oral presentations in international conferences, h-index 20.
Professor, Department of Physics, University of Oslo, Norway and Department of Materials Science and Engineering, KTH Royal Institute of Technology, Sweden
Emerging Cu-based materials are explored to benefit from the energetically high-lying Cu d-state in combination with low effective mass of the minority carriers. Materials with higher functionality open for ultrathin devices and thereby less raw material usage. In this talk, we discuss the details in the optoelectronic properties of emerging Cu-based chalcogenides, like for instance Cu2(Sn,Ge)S3, Cu3Sb(S,Se)3, Cu3Bi(S,Se)3, and Cu2XSnS4 (X = transition metal atom), theoretically analyzed by employing hybrid functionals within the density functional theory. For example, we demonstrate that the band-gap energy Eg of CuSb(Se,Te)2 can be optimized for high energy conversion in ultrathin photovoltaic devices, and that the alloys then exhibit excellent optical properties, especially for tellurium rich CuSb(Se1-xTex)2. This is explained by multi-valley band structure with flat energy dispersions, mainly due to the localized character of the Sb/Bi p-like conduction band states. Still the effective electron mass is reasonable small for CuSbTe2. The absorption coefficient α(ω) for CuSb(Se1-xTex)2 is at ħω = Eg + 1 eV as much as 5–7 times larger than α(ω) for traditional thin-film absorber materials. Auger recombination does limit the efficiency if the carrier concentration becomes too high, and this effect needs to be suppressed. However with high absorptivity, the alloys can be utilized for extremely thin inorganic solar cells with the maximum efficiency ηmax ≈ 25% even for film thicknesses d ≈ 50–150 nm, and the efficiency increases to ~30% if the Auger effect is diminished. The results help to understand fundamental physics of the Cu-based compounds in order to design and optimize very thin solar-energy devices.
References: Persson J. Appl. Phys. 107, 053710 (2010); Chen et al., J. Appl. Phys. 112, 103708 (2012); Crovetto, et al., Sol. Energy Mat. Sol. Cells 154, 121 (2016).
Biography:
Clas Persson, graduated in materials science at Linköping University in 1999. Post doctorate at National Renewable Energy Laboratory, USA, thereafter assistant professor 2004 at KTH Royal Institute of Technology, Stockholm. Since 2011, professor at Department of Physics, University of Oslo in Norway and at the same time, since 2007, associate professor at KTH. His research involves first-principles atomistic modeling of semiconductors for clean energy technologies, and also code development for analyzing materials. He has over 200 publications as collaborative works together with more than 250 researchers at 90 research groups world-wide, and he has supervised twenty post doctors and research students.
Department of Chemistry, Kenyatta University, Kenya
Chlorine added to drinking water as a disinfectant is a concern of this generation. This is because chlorine reacts with dissolved organic compounds to form polychlorinated complexes that are carcinogenic. Available methods for the removal of chlorine and chlorinated compounds include adsorption, precipitation, electrolysis and ozonation, but some result in the generation of more toxic compounds. This study explored the use of zero-valent bimetals Fe/Zn for the degradation of chlorinated compounds in water which did not generate toxic by-products. The zero-valent bimetallic material was anchored on a polystyrene waste material as a green method of cleaning the environment. It was prepared through nitration, amination, complexation and reduction. The resulting solid material was characterised using Fourier transform infrared (FTIR). The material was also characterised using XPS which confirmed the presence of metals anchored on the material through complexation. The metals were also found to be present upon reduction to zero valence and even after the degradation process of the chlorinated organic compounds. It was then applied for the removal process. Optimization parameters such initial halideconcentration, effect of time and bimetal dosage variation were established using synthetic water samples. It was found that the substrate-anchored ZVB material had a degradation capacity of 4.532, 5.362 and 4.513 μmol l-1 for 1,2-dichloroethane, 2-chloro-2-methylpropane and 1-chlorobutane, respectively. The material was then applied on real samples sourced from Nairobi. Quantification of chlorine was done using potentiometric methods and the results confirmed that the degradation was first order. The degradation capacities were found to be 2.37±0.01, 3.55±0.01 and 3.72±0.01 in that order.
Keywords: Polystyrene. Chlorination. Zero-valent bimetals. Degradation. Reduction
Biography:
Isaac Mwangi pursued a HND analytical chemistry course in the Kenya Polytechnic and then a masterʼs degree course at Kenyatta University. He later progressed for a PhD course at the University of Johannesburg. Isaac undertook a postdoctoral research fellowship in that University before returning to Kenyatta University to resume his duties. He is now a Lecturer in the department of chemistry.
Research Summary: Isaac Mwangi is a dynamic scholar with a wealth of experience in teaching and research and is actively involved in supervision of graduate and postgraduate students in research projects in the field of Physical, Applied and Analytical chemistry. His projects are geared towards improvement of the quality of life for various groups of people. His diverse research interests include among others farming in dry and soilless media plus purification of water and sanitation.
American University in Dubai, UAE
Biomechanics is interested in uncovering the link between the structure (nanoscale to milli-scale) of a biological tissue (morphology and histology) to external forces. From a mechanical stand point, properties of these tissues must be determined where an interest is given to load-bearing tissues, bones and connective soft tissues. Collagen fiber-reinforced soft tissues are known to exhibit a complex mechanical behavior that can be separated into a passive response (elastic and inelastic) and an active response (chemical factors, growth and remodeling). In this context, we discuss a behavior law (Holzapfel et al. 2002) that models the mechanical passive behavior of the arterial wall and the related parameter identification problem.
It is widely accepted that the instantaneous response (elastic) of collagen fiber-reinforced soft tissues is fairly modelled by employing the hyperelastic theory. As for Long term inelastic response of the tissue, the theory of viscoelasticity gives good results. However, viscoelasticity raises the challenge as the mathematical formulation of a behavior law will lead to a highly non-linear system with many material parameters to be identified. Fung (2002) proposed the quasi-linear viscoelasticity (QLV) theory after observing that certain connective tissues exhibit a strain-rate insensitive response. QLV resides uses a multitude of classical viscoelastic elements (spring and dampers) to cover the insensitivity spectrum of the tissue. This formulation reduces the complexity of the system but leaves us with many material parameters to be identified. Hence, we propose a new parameter identification approach where the formulation of the problem accounts for the strain-rate insensitivity of soft issues. It is then solved using genetic algorithms. Consistent parameter identification results are obtained despite the non-linearity of these mechanical models.
Biography:
Dr. Nizar Harb is an assistant professor of mechanical engineering at the American University in Dubai since fall 2015. He received his Ph.D. in Mechanics in 2013 from the University of Technology of Belfort-Montbeliard, and also M.Sc in mechanical engineering and design in 2008. His thesis works led to developing novel numerical tools in the context of inverse identification of biomechanical parameters. In 2014, he was assistant professor of mechanical engineering at Higher Engineering School of Mechanics and Aerotechnics (ENSMA), Poitiers, France and was part of research institute Pprime (CNRS).
His main field of research is non-linear solid mechanics, biomechanics, metaheuristic optimization and numerical modeling.
Department of Materials Science, Indian Association for the Cultivation of Science, India
The discovery of Graphene in the beginning of this century, apart from all its superlative properties, marked the beginning of a new class of 2D materials that have been emerging with far reaching potential applications. In spite of all its superlative physical properties, pure Graphene has some serious drawbacks, such as absence of band gap, that limits its usage in devices. 2D nanosheets analogous to graphene, such as h-BN, III-IV-V nanosheets phosphorene, layered transition metal dichalcogenide (MX2, M=TM, X=S, Se, Te) etc. exhibit band gaps that can be tailored by varying the number of layers, by cutting nanoribbons along Zigzag or Armchair edges, by heterostructuring or by chemical functionalization. For example, there is an interesting manifestation of quantum size effect on the electronic behavior of layered VX2 as a function of the number of layers. Many of these quasi-2D TMDCʼs, grown epitaxially on metallic or semiconducting substrates, result in lattice matched / mismatched heterostructures with different kinds of bonding ranging from weak Van der Waals bonding to relatively stronger ionic/covalent bonding. Physical and chemical properties of such overlayers often get modulated by the sub-surface layers of the corresponding substrates, leading to manifestation of new properties. In this talk, I shall discuss how density functional theory (DFT) based first principles simulation can be used in designing different classes of 2D materials and also to functionalize these for various applications in materials science, catalysis and device physics. Finally, I shall highlight the increasing relevance of combining machine learning and combinatorial techniques with DFT data base on 2D and quasi-2D materials.
Biography:
Dr. G.P. Das is a condensed matter physicist and a materials scientist working as a senior professor in the Indian Association for the Cultivation of Science in Kolkata, India. His research interests span a wide cross-section encompassing electronic structure and properties of various kinds of alloys, interfaces, clusters, and nanostructured materials. He has been working on spintronics materials, hydrogen storage materials, two dimensional nanostructures beyond graphene, and various quantum structures. He served as visiting scientist in several institutes abroad viz. Max Planck Institute Stuttgart (Germany), Virginia Commonwealth University, Richmond (USA), Institute of Materials Research, Sendai (Japan), University of New South Wales (Australia).
Mechanical Power Engineering Department, Faculty of Engineering, Cairo University, Egypt
This paper considered lubricating journal bearings with ferro fluids which are widely used now to overcome many difficult problems such as sealing, thermal effects, and damping problems. Ideally when a journal bearing is installed the axis of the journal and the axis of the bush are parallel. Nevertheless, in practice, this ideal condition rarely exists, and the shaft tends to suffer from some degree of misalignment while rotating inside the bush. Misalignment could cause overheating, wear, vibration and eventually failure. A pressure differential equation is used for journal bearing lubricated by Ferro fluid taking into consideration that the misalignment of the shaft is considered in magnitude as well as direction with respect to the bearing boundaries. It is found the bearing performance characteristics can be enhanced by using Ferro fluid and the problems caused by misalignment may be significantly reduced by the proper selection of the magnetic field model and the careful choice of design parameters of the model used The analysis reveals that the magnetic force is able to decrease the side leakage and the frictional forces arise due to misalignment of the journal axis
Biography:
Dr. Zeinab Safar is Emeritus Professor of Mechanical Engineering Department at Cairo University; she had her B.S. degree from Cairo University, M.S. degree and Ph.D from University of Pittsburgh, USA. In addition to Cairo University Dr Safar worked in many universities as visiting professor such as University of California Berkeley, Aachen University and the American University in Cairo. She has more than 80 publications in the areas of Tribology, Energy, and Environment in International Journals and Conferences. Dr. Safar has received the Change Agent Award from ABI and the Community Research Prize from Cairo University. She is a member of the Board of the Electricity Holding Company and the National Committee of Women in Science and Technology in the Academy of Scientific Research.
Istituto Italiano di Tecnologia, Italy
In the last years we introduced different 3D nanostructures and devices for managing the electromagnetic field at the nanoscales through the generation of surface plasmons polaritons. Firstly, we will briefly revise our past achievements concerning 3D plasmonic nanostructures and their applications to bio-sensing. Secondly, we will show our recent achievements and future perspectives of plasmonic nanopores for next generation sequencing of DNA and protein (European Project FET-Open “Proseqo”, GA N°687089). In the final part we will present the exploitation of 3D nano-devices in combination with CMOS arrays for intracellular recording of action potentials in mammalian neurons and intracellular delivery of biomolecules, genic materials and nanoparticles. Also, the active interaction of the cell membrane with such 3D devices will be discussed. The developed platform may enable significant advances in the investigation of the neuronal code, development of artificial retinas and low-cost in-vitro platforms devoted to the pharmacological screening of drugs for the central nervous system. As future perspective we will also discuss potential application of our system for the investigation of electrical activities of plant roots that in the near future may revolutionize plant biology. This project is supported by the European Community through the IDEAS grant program
(“Neuroplasmonics”, GA N° 616213).
Biography:
Francesco De Angelis is currently Senior Scientist at the Italian Institute of Technology and Supervisor of Nanostructure Facility (clean room). He leads the Plasmon technology Unit (about 25 members) and his main expertise relies on micro and nano-optical devices for biomedical applications. He currently holds an IDEAS-ERC Consolidator grant whose aim is to develop radically new interfaces between electrical/optical devices and neuronal networks. He published more than 100 papers on peer-review impacted journals; total impact factor > 700; H index = 36, citation=5000.
Director, Center for Research in Advanced Sensing Technologies & Environmental Sustainability (CREATES), Department of Chemistry, State University of New York at Binghamton, USA
Research into anisotropic nanomaterials has significantly increased due to their potential applications in cancer cell imaging, surface enhanced Raman scattering, sensors, optical contrast agent, photochemical cancer therapy among other applications. Anisotropic nanomaterials are a class of materials whose structures, properties, and functions are direction-dependent. This presentation will focus on the use of poly (pyromelliticdianhydride-p-phenylene diamine) (PPDD) as a reducing & stabilizing agent, immobilization matrix, and directional template for the synthesis of anisotropic silver nanoparticles (AgNPs). It will also discuss a new physical insight into the mechanisms of directional templating of anisotropic nanoparticles based on diffusion limited aggregate model and coalescence growth mechanism. Molecular dynamics (MD) simulations and density functional theory (DFT) calculations were performed to provide insight into possible conformation of PPDD monomer. Anisotropic (non-spherical) peanut-shaped, nanorods and dendritic nanostructures were prepared in situ using varying concentrations of precursors from 0.1% w/v to 1.0 % w/v within PPDD matrix. The PPDD served as the reducing and directional template, thus enforcing preferential orientation. The mechanism of formation and growth of the polymer-mediated anisotropic nanoparticles was confirmed using transmission electron microscopy (TEM), UV-vis near-infrared absorption spectra (UV-vis-NIR), and X-ray diffraction (XRD).
1University Center BELHADJ Bouchaïb, Algeria
2Laboratoire Materiaux (LABMAT) Ecole Nationale Polytechnique (ENP), Algeria
Information on electronic distribution of the valence band and deep levels on In2O3 is very necessary to predict its applications in technological fields. We adopt the computational simulation based on GGA (Generalized Gradient Approximation) and mBJ (modified Becke Johnson) approximations using the Wien2K program to obtain the electron distribution. The valence band involves the hybridization of the s and p states of the indium chemical species and the oxygen in the range 6eV to 0eV. The characteristics related to these states s and p are very discriminated from other characteristics located at low energies linked to the d states of indium in the range 13 eV to 11eV. The calculation results allow us to predict the interband transition. Moreover, the distribution of electrons around the cation (indium) and the anion (oxygen) allows us to determine the ionic character of the chemical bond in the compound In2o3. We confirm these results using AES (Auger Electron Spectroscopy) and EELS (Electron Energy Loss Spectroscopy) electronic spectroscopy characterization methods.
Keywords: GGA and mBJ approximations; In2O3; AES and EELS spectroscopy.
Institut des Sciences, Centre Universitaire BELHADJ Bouchaib dʼAin Témouchent, Algeria
The full potential linearized augmented plane wave (FP-LAPW) method within density functional theory [1] is applied to study, for the first time, the structural and electronic properties of CaFI and to compare them with CaFCl and CaFBr, all compounds belonging to the tetragonal PbFCl structure group with space group P4/nmm. We used the generalized gradient approximation (GGA) [2] based on exchange–correlation energy optimization to calculate the total energy and also the Engel–Vosko GGA formalism, which optimizes the corresponding potential for band structure calculations. Ground state properties such as the lattice parameters, c/a ratio, bulk modulus, pressure derivative of the bulk modulus and cohesive energy are calculated as well as the optimized internal parameters, by relaxing the atomic position in the force directions. The variations of the calculated interatomic distances and angles between different atomic bonds are discussed. CaFCl was found to have a direct band gap at 5 whereas CaFBr and BaFI have indirect band gaps. From these computed bands, all three materials are found to be insulators having band gaps of 6.28, 5.46 and 4.50 eV, respectively. We also calculated the valence charge density and the total density of states at equilibrium volume for each compound. The results are in reasonable agreement with the available experimental data.
Department of Physics, University of Karachi, Pakistan
The origin of ferromagnetism in dilute magnetic semiconductors remains an issue of debate [1]. Two main scenarios are discussed: acceptor induced holes in the host valence band and holes in an impurity band. Experimental evidence for the existence of an impurity band based on optical properties has been presented [2], though later studies suggest that the data are consistent with the valence band model [3]. Support for an impurity band scenario is also obtained from resonant tunneling experiments on quantum well structures [4]. Two other recent studies, one based on channeling in combination with magnetization, transport, and magneto-optical experiments [5], the other on hard X-ray photoemission [6], have come to different conclusions: the first one supporting an impurity band model in which the location of the Fermi level within the impurity band plays a crucial role in determining the Curie temperature (TC), the second emphasizing the coexistence of coupling mechanisms in the impurity band and host valence band models. It is clear that further reliable experimental work is needed to clarify the situation and provide directions for systematic procedures to find the optimally stabilized ferromagnetic state.
Our recent work on Mn-doped GaAs has revealed new unexpected features, including a spin polarized energy band with strong in-plane dispersion, extending slightly above the VBM of GaAs. Very surprisingly, similar observations are made above and below the Curie temperature of (Ga,Mn)As (typically 70K for as-grown samples). Since the band structures of the para- and ferromagnetic states are predicted to be distinctly different [7], even if the exchange splitting is very small [3], this result is not compatible with the currently accepted view of (Ga,Mn)As. The combined information gathered so far indicates that there exists a ferromagnetic surface layer on (Ga,Mn)As even at room temperature.
References
[1] N. Samarth, Nature Materials 11, 360 (2012)
[2] K. S. Burch et al., Phys. Rev. Letters 97, 087208 (2006)
[3] T. Jungwirth et al., Phys. Rev. Letters 105, 227201 (2010)
[4] S. Ohya, K. Tanaka, and M. Tanaka, Nature Physics 7, 342 (2011)
[5] M. Dobrowolska et al., Nature Materials 11, 444 (2012)
[6] A.X. Gray et al., Nature Materials 11, 957 (2012)
[7] K. Sato et al., Rev. Mod. Phys. 82, 1633 (2010).
1Materials, Loughborough University, UK
2Institut für Metallkunde und Metallphysik, RWTH Aachen University, Germany
This paper will re-consider the basic aspects of solid state classical heterogeneous nucleation theory. In particular it will show how recent experimental work that has been able to estimate grain boundary triple junction line energy can be used to supplement the understanding of the energy balance operating during nucleation. This implies that the energy of the newly created interface needs to be recalculated, assuming that the additional line energy of the line surrounding the precipitate in the plane of the boundary is taken into account. Examples will be given of the application of this revised approach to GB precipitate nucleation of cap-shaped particles of chromium carbide in nickel based alloys. It will be shown that original assumed values of the precipitate-matrix interfacial energy for this transformation have to be revised downward for critical nucleus sizes of less than about 10nm.
Biography:
Professor Roy Faulkner (Loughborough Materials Ltd) has been involved with nuclear reactor materials research for almost three decades. He was employed as a consultant to UKAEA, Harwell from 1980-90, and has led are search group interested in nuclear reactor materials at Loughborough University since 1990, with funding support from Rolls Royce Naval Marine, EDF, Magnox, EPSRC, and Oak Ridge National Laboratories. His interests are in breeder blanket ferritic ODS steel development for fusion, radiation-induced grain boundary segregation of P in Pressure vessel steels, and radiation induced chromium depletion in austenitic steels. Non-irradiation based interests, but still relevant to the current project proposal, are thermally induced chromium depletion modeling and experimental validation in Alloys 600 and 690, modeling and validation of micro structural evolution in ferritic and austenitic steels, and nickel base alloys, and its relation to creep and fracture toughness properties in these alloys. His overall mission is to provide, by modelling, a better understanding of micro structural changes occurring in high alloy steels and nickel based alloys in irradiation and high temperature environments. This mission is supported by a strong experimental expertise in high resolution microscopy techniques, most of which are available in the Loughborough Materials Characterisation Centre. He is Past-President of the East Midlands Metallurgical Society, Chairman of the IOM3 Publications Committee, and past Chairman of the IOM3 Younger Members Committee. He is also Past-Chairman of the Midlands Microanalysis Group.
Politehnica University of Bucharest, Romania
The new generation ductile iron with up to 6.0% Si exhibits a fully ferritic matrix, which is solution strengthened by silicon. Outstanding advantages of these grades result in their strongly increasing demand, especially in the automotive industry. The strength of ferritic irons is improved or the instability of a mixed ferritic-pearlitic matrix could be replaced with more predictable and controllable ferritic grades. Because of the combination of a high strength and good elongation it is possible to decrease the wall thickness (light weight construction); the hardness and tensile strength is homogenous over the wall thickness. The machining cost is decreased. More than 4.0%Si enhances performance at elevated temperatures by stabilizing the ferritic matrix and forming a silicon-rich surface layer, which inhibits oxidation. Molybdenum additions up to 2%, to more than 3.5%Si, give superior mechanical properties at high temperatures and improved resistance to oxidation. More than 3.0%Si increases the corrosion resistance.
Experiments studied the solidification pattern of three ductile iron compositions [2.5%Si; 4%Si and 4%Si-1.6%Mo], by thermal analysis technique. Wedge samples having a different cooling modulus [ASTM A367] and rapidly graphite nodularity testing samples were also produced. Despite that silicon favours chunky graphite formation, effective inoculation decreased the sensitivity to form a dark coloured porous region in the thermal centre of Si-alloyed ductile iron and limited it in Si-Mo ductile irons. Alloying with silicon reduced the carbides sensitiveness for the entire solidification cooling rate range in both un-inoculated and inoculated irons. Without inoculation a supplementary Mo addition drastically decreased the beneficial effect of Si on undercooling. It was found that inoculation is important for high-Si but particularly so for Si-Mo alloyed irons, requiring a high efficiency inoculation procedure.
Biography:
Iulian Riposan is a Professor of Materials Science and Engineering in POLITEHNICA University of Bucharest, Romania; He published more than 300 scientific papers [published in 32 countries]; 35 Papers at American Foundry Society (AFS) / Ductile Iron Society Conferences; 22 Papers at World Foundry Congresses; 16 Papers at World Conferences on Cast Irons; 35 Romanian Patents; AFS International Member; Award of Romanian Science Academy; 2012 American Foundry Society Scientific Merit Award “for advancing the knowledge of the cast iron industry through extensive research and for generously sharing his knowledge and expertise with the industry”;BEST PAPER AWARDS: 63rd World Foundry Congress; 106th and 107th American Foundry Society Congresses.
1Department of Applied Science and Technology, Politecnico di Torino, Italy
2National Research Council (CNR) of Italy, Istituto di Chimicadella Materia Condensata e di Tecnologie per lʼEnergia (ICMATE), Italy
The intermetallic alloy Ti-48Al-2Cr-2Nb is used for fabrication of low pressure turbine blades, because itʼs good mechanical properties, low density and oxidation resistance at high temperature. However, the alloy application is still limited by significant oxidation above 850 °C. A thin AlTiN ceramic coating of about 3 μm, applied by magnetron spattering, can improve the surface oxidation resistance of this intermetallic alloy. The objective of this work is to investigate the integrity and oxidation resistance of TiAlN coating after thermal cycling under oxidizing atmosphere at temperatures up to 850°C and 950°C. Thermal cycling was performed in a burner rig specifically designed to simulate the operating conditions of turbine engine components.
Biography:
Oxana Ostrovskaya graduated in chemical technology of refractory non-metal and silicate materials at Belgorod Shukhov State Technological University (Russian Federation) in 2003, and she received her M.S. Degree in Materials Science and Technology from Politecnico di Torino (Italy) in 2014. At present, she is a Ph.D student in Materials Science and Technology at “Politecnico di Torino”, Italy. Currently, her researches focus on Intermetallic Alloys with or within thin protective coating for aerospace applications. Oxana Ostrovskaya co-authored 3 paper articles.
Department of Civil, Structural & Environmental Engineering, Trinity College, The University of Dublin, Ireland
Spectral losses due to limited spectral response represent a fundamental limit to the maximum efficiency achievable by the solar cell. Low energy photons are not absorbed by the solar cell, while high energy photons are not used efficiently and energy is lost via thermalization. Also the dependency on direct normal irradiance (DNI) limits the application of photovoltaic technology in building integrated photovoltaic (BIPV) for climate where diffuse solar radiation is dominate. The potential exists to increase solar cell efficiency by making better use of short wavelength light and concentrating solar radiation using static concentrator. One way to do this is to use a luminescent materials to down shift high energy photons to lower energy photons through energy downshifting and simultaneously concentrating solar radiation. The conversion of the high energy photons to lower energy phones before they interact with the solar cell refer to as luminescent down shifting layer (LDS) and when the energy downshifting combined with solar energy concentration, itʼs known as Luminescent Solar Concentrators (LSC). The LSCs were proposed with the potential of reducing the cost of solar electrical power generation and LDS with the potential of increasing the solar cell efficiency. LSC and LDS suffer from self-absorption, escape cone losses, and scattering losses at higher concentrations of luminescent species hence undermining the efficiency of the device. Some of these losses could be significantly reduced if it were possible to guide the emission directionally and decrease the luminescent species concentration without compromising the total emission in device. A novel approach was proposed to utilize metal nanoparticles with the objective of counteracting these optical loss mechanisms. In this technology, plasmonic coupling between luminescent species and metal nanoparticles has been exploited, resulting in significant enhancement in absorption and fluorescence emission of luminescent species. First, the optimum luminescence species concentration in polymer was established. Subsequently, plasmonic coupling with MNP was introduced and optimum plasmonic coupling determined. The plasmonic interaction was manipulated through variation of the spacing between the luminescence species and MNP and of the surface plasmon resonance (SPR) frequency of MNP. The spacing was controlled by the relative concentration distribution of luminescence species and MNPs. The SPR resonance was determined by controlling the size and shape of the MNPs. Optimised plasmonically enhanced luminescence devices were fabricated and the performance of these devices was experimentally tested on different PV solar cells through optical and electrical characterization. The results have shown significant enhancement in absorption, fluorescence emission and electrical output of PV/plasmonic devices.
Biography:
Dr. Hind Ahmed is a graduate of the prestigious Graduate Studies Program at the Singularity University, NASA AMES, California, USA. She has a strong background in Mathematics, Physics and Engineering with the focus in the area of solar energy research. She holds an Honourʼs degree in Physics, a Postgraduate Diploma in Mathematical Sciences, a Master degree in Material Physics, a Professional Master in Micro/Nano Electromechanical System and a PhD in Physics. She is currently working as a senior research fellow in the Solar Energy Applications group in Trinity College Dublin under ERC Starter grant ‘ʼPlasmonic Enhancement and Directionality of Emission for Advanced Luminescent Solar Devices (PEDAL)ʼʼ which involves the design, development, characterisation and fabrication of large scale plasmonic luminescent down shifting devices for enhancing the efficiency of solar cells.
Centre de Sciences Nucleaires et de Sciences de la Matiere, CNRS-University Paris-Sud, France
Uranium dioxide (UO2) is much-used nuclear fuel over the world especially in light water reactor. It is subjected to significant restructuring processes during its operating life in the reactor core. Although it is well established that uranium dioxide does not become amorphous under irradiation, UO2 exhibits a defective structure, whose specific microstructure depends on several parameters (e.g. local burnup, local temperature, irradiation conditions, nuclear and electric stopping, and incorporated impurities). In particular, a zone located at the peripheral region of the nuclear fuel pellet (100-200 μm extension) submitted to extreme irradiation conditions, leading to grain subdivision and pore formation, – referred to as the High Burnup Structure (HBS) – focuses attention on the role played by the various parameters either in a separate or in a combined way on the solid destabilization. The main objective of this investigation is to understand the formation mechanisms of the HBS structure and the behavior of a material under irradiation. This goal is achieved experimentally by using a very simplified model - urania single crystals - irradiated with low-energy ions to examine the contributions of ballistic damage and of implanted species to the formation of the HBS structure. Crystals were alternatively (i) implanted at increasing fluence steps with 500-keV Xe or La ions (soluble and insoluble species in UO2, respectively) at 773 K (the temperature at the periphery of the fuel) and (ii) characterized in situ by Rutherford Backscattering Spectrometry in Channeling geometry (RBS/C) and in situ Transmission Electron Microscopy (TEM). Two important steps in the disordering kinetics of the solid were established and they were interpreted in terms of the transition from the formation of isolated defects to extended defects at a low dpa number, and due to the aggregation of impurities when their concentration reaches a critical threshold. This second step was solely observed for the insoluble specie.
Biography:
Yara Haddad is graduated from Jordan University of Science and Technology, Jordan, with a bachelor degree in Nuclear Engineering. Later she completed Master degree in nuclear engineering (M2) in the field of nuclear power design from ENSTA, Paris and she is completing her Ph.D. in physics, in particular physics of materials at University Paris-Sud with an expected degree date of December 2017.
1Kenyatta University, School of Pure and Applied Science, Kenya
2Kenyatta University, School of Medicine, Kenya
3Jomo Kenyatta University of Agriculture and Technology, School of Agriculture, Kenya
Untreated waste water is used for growing of vegetables in small scale urban farming. Vegetables grown or irrigated with untreated wastewater may contain high levels of antibiotics residues that are detrimental to health. Sulfamethoxazole (SMX) is an antibiotic, administered in the management of pneumocystis carinii pneumonia, pneumocystis jiroveci pneumonia, toxaplasmosis and genitourinary tract infections in HIV-AIDS patients or in cases of oral thrush infections. It is cheap and readily available over the counter even through self-prescription for management of upper respiratory tract and genitourinary tract infections. The drug is also administered to poultry and livestock as a growth promoter, prophylactic and to control microbial infections. Its presence in vegetables could induce microbial resistance and minimize drug sensitivity. The concentration of sulfamethoxazole in untreated wastewater and vegetables collected during the dry season from various sites in Ruai and Njiru from small scale urban farms along Ngong River was determined. The samples for sulfamethoxazole residues underwent solvent extraction pre-analysis and the extracts were then analyzed using high performance liquid chromatography. The untreated waste water and vegetables were found to have sulfamethoxazole residues.
Keywords: Wastewater Sulfamethoxazole Vegetables Human Health.
Department of Electronic Engineering, Jeju National University, Republic of Korea
In general, the polymer thin film is formed through a solution process to be fabricated as optical devices or electronic devices. Therefore, the solvent is removed through heat treatment to complete the solid state thin film. However, the surface roughness of the amorphous polymer is kept low, but in the case of the crystalline or semicrystalline polymer, the surface becomes very rough as the crystallization increases. In general, the thicker the film, the greater the roughness becomes. It is necessary to minimize the surface roughness since it adversely affects subsequent processes carried out on the polymer thin film having such a rough surface.
In this paper, we describe a method of forming a ferroelectric thin film of semicrystalline and reducing the surface roughness by solution process and plasma process, respectively. The solution process was a double coating method. Through the plasma process, dry etching with appropriate process variables was used. As a result, more flat surface than the initial state was obtained. It is expected that the method presented here will be very helpful for improving the performance of organic optoelectronic devices.
Acknowledgement: This research was financially supported by The Project Management Center Cultivating Smart Grid & Clean Energy Manpowers (CK-1), JNU
Biography:
Ms. Hyo In Jin is an undergraduate student at Jeju National University in Korea, and her research interests are semiconductor devices and processes. Prof. Dr Woo Young Kim is an assistant professor at Jeju National University in Korea. His research fields include applications of ferroelectric polymer and graphene process.
Department of Electronic Engineering, Jeju National University, Republic of Korea
The ferroelectric material is a material that forms a spontaneous polarization by an electric field or voltage applied from the outside, and is widely applied to a nonvolatile memory device because it maintains a polarization state even when an external stimulus is removed. The polarization of the ferroelectric does not cause polarization reversal below a certain threshold voltage (coercive voltage), but polarization reversal gradually occurs when the voltage exceeds the coercive voltage. Therefore, the coercive voltage is an important criterion for determining the operating voltage in a ferroelectric memory or a switching device.
This paper deals with the coercive voltage of a ferroelectric capacitor with two ferroelectric capacitors with different thicknesses. The hysteresis curve was measured by varying the area of the two capacitors. As a result, it was confirmed that the coercive voltage can be modulated according to the area ratio of the two capacitors. Using a ferroelectric with this structure would be advantageous for fabricating devices with arbitrary coercive voltages.
Biography:
Mr. Jin San Kim is an undergraduate student at Jeju National University in Korea, and his research interests are semiconductor devices, programming and circuit design. Prof. Dr Woo Young Kim is an assistant professor at Jeju National University in Korea. His research fields include applications of ferroelectric polymer and graphene process.
Acknowledgement: This research was financially supported by The Project Management Center Cultivating Smart Grid & Clean Energy Manpowers (CK-1), JNU.
Department of Electronic Engineering, Jeju National University, Republic of Korea
A multi-bit memory is a memory capable of storing two or more data in one memory cell. In the case of a ferroelectric memory, a voltage variable type multi-bit memory device has been proposed so far. The polarization of the ferroelectric is represented by the average value of the dipole moments inside the thin film, which can be changed by the voltage or electric field applied in the external stimulus. Therefore, it is theoretically possible to store states corresponding to all polarization values from positive residual polarization to negative residual polarization. However, when implemented as an integrated circuit due to process errors and voltage fluctuations, the number of data that can be stored is limited due to reliability. In this paper, we propose a memory cell with twocapacitors of two different thicknesses. Because of the different thicknesses of the capacitors, the variability of polarization due to voltage variation and process error is minimized. The ferroelectric used is a ferroelectric polymer.
In addition, various process methods of the proposed structure will be mentioned. The first is the combination of the polymer film patterning and transferring, the second is the patterning and double coating of the polymer thin film, and the third is the same performance by using only the photosensitive polymer film without patterning the ferroelectric polymer film. Particularly, the third demonstration method will be more useful because it does not use vacuum equipment, it improves multi-bit memory productivity and compatibility with large area printing and printing process.
Biography:
Mr. Seong Cheol Moon is an undergraduate student at Jeju National University in Korea, and his research interests are semiconductor memorydevices. Prof. Dr Woo Young Kim is an assistant professor at Jeju National University in Korea. His research fields include applications of ferroelectric polymer and graphene process.
Acknowledgement: This research was financially supported by The Project Management Center Cultivating Smart Grid & Clean Energy Manpowers (CK-1), JNU.
Department of Electronic Engineering, Jeju National University, Republic of Korea
Graphene is a material consisting of a single layer of carbon atoms, known to have excellent mechanical and electrical properties. In particular, the adjustment of the doping concentration by chemical adsorption or electrical gating is a very useful method for varying the conductivity of graphene. Graphene can be used as a memory element if this conductivity can be adjusted to more than two states and its adjusted conductivity can be maintained. In this paper, we will demonstrate a memory device that can memorize the conductivity of graphene by grafting ferroelectric polymer with memory characteristics.
The graphene memory demonstrated in this paper was fabricated by stacking a graphene - ferroelectric composite film. Since the device can be manufactured only in a desired place, the use amount of the graphene can be reduced, and the type of the substrate may not be affected. In addition, the surface of the ferroelectric polymer layer was modified to improve the memory characteristics. It is expected to be applicable to future flexible and transparent memory devices.
Biography:
Mr. Seung Hyeon Kim is an undergraduate student at Jeju National University in Korea, and his research interests are memory devices and processes. Prof. Dr Woo Young Kim is an assistant professor at Jeju National University in Korea. His research fields include applications of ferroelectric polymer and graphene process.
Acknowledgement: This research was financially supported by The Project Management Center Cultivating Smart Grid & Clean Energy Manpowers (CK-1), JNU.
Department of Electronic Engineering, Jeju National University, Republic of Korea
Recently, studies on the improvement of the integration degree of memory devices using ferroelectric polymers have been actively conducted. Methods of increasing integration include horizontal physical scaling, storing multiple bits in a single memory cell, and building a stacked structure.
Among them, multi-bit memory is a useful concept to increase the memory capacity with using the existing processes because it can increase the integration degree without reducing the horizontal physical length. In this paper, we point out the problems of the conventional ferroelectric multi - bit memory integration method and propose a multi - bit memory device structure which can improve the degree of integration by using the stacked structure and verify its operation. In addition, the proposed architecture is robust against interference when integrated.
Acknowledgement: This research was financially supported by The Project Management Center Cultivating Smart Grid & Clean Energy Manpowers (CK-1), JNU
Biography:
Mr. Uichang Lee is an undergraduate student at Jeju National University in Korea, and his research interests are semiconductor devices and circuit design. Prof. Dr Woo Young Kim is an assistant professor at Jeju National University in Korea. His research fields include applications of ferroelectric polymer and graphene process.
Department of Chemistry, University of Sharjah, UAE
Polyacrylamides constitute a class of polymers that can entirely dissolve or swell in water to form a solution or hydrogel respectively. Free radical polymerization of acrylamide monomer, using both solution and inverse-emulsion polymerization, was applied to produce polyacrylamide with various molecular weights. This investigation was focused on the production of polymers with different molecular weights, depending on monomer to initiator ratio. Experimental conditions were designed to produce high molecular weight polymers that can be used in stabilization of sand dunes in the arid regions. Synthesized polyacrylamide samples were characterized using Gel Permeation Chromatography and solution viscosity in order to determine the molecular weights and molecular weights distribution. The rheological behavior was also investigated in different polymer concentrations and at various temperatures using Brookfield Rheometer. Lab-scale wind tunnel was used to determine the stability of the sand before and after treatment with the polymer. Compressive stress-strain test was also used to establish the mechanical behavior of the polymer-sand composite under controlled compressive load up to failure. The results showed that the use of high molecular weight polymer gave excellent mechanical and thermal stability.
1Department of Biology, Faculty of Science, University of Hail, Saudi Arabia
2Department of Food Processing, Faculty of Engineering, University of Elemam Elmahadi, Sudan
The present study was conducted to investigate the production of ethanol from sorghum grains (Feterita) and evaluation of its quality. Proximate chemical composition in terms of protein, crude fiber, moisture, ash, oil and carbohydrate contents were determined in sorghum grains and malted grains flours. The results indicated that sorghum grains flour contained 12.7% protein, 1.6% crude fiber, 5.3% moisture, 1.8% ash, 2.7% oil and 76.1% carbohydrate. On the other hand, malted grains flour contained 13.1% protein, 1.7% crude fiber, 5.5% moisture, 2% ash, 2.8% oil and 74.9% carbohydrate. Malt and pure enzymes (α-amylase and amyloglucosidase) were used to convert the starch to fermentable sugars. The yield of ethanol in fermented mash was 13% in the malt and 16% as a result of using pure enzymes. The ethanol volume produced from sorghum grains by malt and pure enzymes was 33 and 35ml, respectively. The purity, density and viscosity of resulted ethanol were 95%, 0.83 gm / ml and 0.99cip, respectively.
Biography:
Prof. Abdel Moneim has been awarded his PhD in 2001 and pursued a postdoctoral fellowship at the University of Kobe, Japan. He is an expert in Food Science and Technology, his main concern is food microbiology. Prof. Abdel Moneim has authored a large number of articles in reputed journals and has been invited to different international conferences. He published many books in the area of food science and technology. He is a member of many national and international academic associations.
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