Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), Taiwan
Imaging Atmospheric Cherenkov Telescopes have revealed more than 100 TeV sources along the Galactic Plane, around 45 per cent of them remain unidentified. However, radio observations revealed that dense molecular clumps are associated with 67 per cent of 18 unidentified TeV sources. In this talk, we propose that an electron-positron magnetospheric accelerator emits detectable TeV gamma-rays when a rapidly rotating black hole enters a gaseous cloud. Since the general-relativistic effect plays an essential role in this magnetospheric lepton accelerator scenario, the emissions take place in the direct vicinity of the event horizon, resulting in a point-like gamma-ray image. We demonstrate that their gamma-ray spectra have two peaks around 0.1 GeV and 0.1 TeV and that the accelerators become most luminous when the mass accretion rate becomes about 0.01 per cent of the Eddington rate. We compare the results with alternative scenarios such as the cosmic-ray hadron scenario, which predicts an extended morphology of the gamma-ray image with a single power-law photon spectrum from GeV to 100~TeV.
Biography:
Kouichi Hirotani investigated plasma phenomena in strong gravitational field around black holes and neutron stars. He awarded the DSc degree from Nagoya University on his research on general relativistic magnetohydrodynamic accretion onto rotating black holes. After that, He studied the gamma-ray emissions from pulsar magnetospheres by developing a numerical code that solves the set of stationary Maxwell-Boltzmann equations in National astronomical observatory in Japan, NASA/GSFC in the USA, MPI-Kernphysik in Heidelberg, Germany, and ASIAA in Taiwan. He applied the same method to black-hole magnetospheres and am investigating very high energy emissions from the direct vicinity of the event horizon.
Firat University, Turkey
Shape memory alloys are stimulus responsive materials to the external conditions, and exhibit a peculiar property called shape memory effect, Shape memory effect is initiated by cooling and stressing material, and activated on heating and cooling following the initiated processes. Shape memory behaviour of shape memory materials is evaluated by the structural changes in crystallographic level. Shape memory effect is governed by successive structural transformations; thermal induced and stress induced martensitic transformations, in atomic and crystallographic basis. Thermal induced martensitic transformation occurs with cooperative movements of atoms by means of shear-like mechanism on cooling from parent austenite phase region. Product martensite phase occurs as martensite variants in self-accommodated manner with lattice invariant shears on the {110}-type close packed planes of austenite matrix. Therefore, 24 martensite variants occur in different orientations. Thermal induced martensite occurs as twinned martensite, and the twinned structures turn into detwinned structures by means of stress-induced martensitic transformation by stressing the material in the martensitic condition. Shape memory alloys can be easily deformed through variant reorientation or detwinning process. Therefore, martensite is called soft phase and austenite is also called hard phase. Shape memory effect is activated thermally on heating and cooling after first cooling and stressing processes, this behaviour can be called thermoelasticity. Shape memory alloys exhibit another property called superelasticity, which occurs by only mechanically stressing and releasing at a constant temperature in parent phase region. This is result of stress induced martensitic transformation, at which stress strain curves follow different ways on heating and releasing. This result refers to energy dissipation.
Copper based alloys exhibit this property in metastable β-phase region. Lattice invariant shears are not uniform in these alloys, and the ordered parent phase structures martensitically undergo the non-conventional long-period layered structures on cooling. The long-period layered structures can be described by different unit cells depending on the stacking sequences on the close-packed planes of the ordered lattice. In the present contribution, x-ray and electron diffraction studies were carried out on two copper based CuZnAl and CuAlMn alloys. These alloy samples have been heat treated for homogenization in the β-phase fields. X-ray diffraction profiles and electron diffraction patterns reveal that both alloys exhibit super lattice reflections inherited from parent phase due to the displacive character of martensitic transformation. X-ray diffractograms taken in a long time interval show that diffraction angles and intensities of diffraction peaks change with the aging time at room temperature, and this result leads to the rearrangement of atoms in diffusive manner.
Keywords: Shape memory effect, martensitic transformations, thermoelasticity, thermoelasticity, lattice twinning and detwinning.
Biography:
Dr. Adiguzel graduated from Department of Physics, Ankara University, Turkey in 1974 and received PhD- degree from Dicle University, Diyarbakir-Turkey. He studied at Surrey University, Guildford, UK, as a post doctoral research scientist in 1986-1987, and studied on shape memory alloys. He worked as research assistant, 1975-80, at Dicle University and moved to Firat University, Elazig, Turkey in 1980. He became professor in 1996, and he has already been working as professor. He published over 50 papers in international and national journals; He joined over 100 conferences and symposia in international and national level as participant, invited speaker or keynote speaker with contributions of oral or poster. He served the program chair or conference chair/co-chair in some of these activities. In particular, he joined in last four years (2014 - 2017) over 30 conferences as Keynote Speaker and Conference Co-Chair organized by different companies. He supervised 5 PhD and 3 M.Sc- theses.
Dr. Adiguzel served his directorate of Graduate School of Natural and Applied Sciences, Firat University, in 1999-2004. He received a certificate awarded to him and his experimental group in recognition of significant contribution of 2 patterns to the Powder Diffraction File – Release 2000. The ICDD (International Centre for Diffraction Data) also appreciates cooperation of his group and interest in Powder Diffraction File.
Universitat of Barcelona, Spain
Institute of Nano-science and Nanotechnology (IN2UB)
The Blood-Brain-Barrier (BBB) is the tight membrane that protects our brain and represents the major hindrance to the use of chemotherapeutic agents for brain tumors.
Recently it has been showed by in vitro and in vivo studies that the adsorption of apolipoprotein E4 (ApoE4) on lipid nanoparticles (NPs) produces a protein corona that enhances the BBB-crossing, improving brain NP accumulation 3-fold compared to undecorated particles. Therefore, it is possible to increase the ability to cross the BBB for engineered NPs carrying a loose layer of proteins. Nevertheless, the NP-protein corona composition––and, as a consequence, the cellular biological response to the NP––change over time as a consequence of the competition among the plasma proteins once the NP is in the blood stream, as we showed.
In collaboration with experimental groups, we develop a multiscale approach for the study of bio-membranes, proteins, NPs and nanomaterials in aqueous solution oriented to applications to the BBB crossing for oncological treatments. We model the kinetics of NP interaction with proteins, of proteins with water, and of water with membranes and nanomaterials, with the aim of finding how to optimize the NP-protein corona formation to cross the BBB.
We will describe our recent results by all-atom simulations and coarse-grained models, e.g. showing that the water-membrane interface has a structural effect at ambient conditions that propagates further than the often-invoked 1 nm length scale and that the translational and rotational dynamics of water molecules is strongly determined by their local distance to the membrane so that we can identify the existence of an interface between the first hydration shell, partially made of hydration water bound to the membrane, and the next shells entirely made of unbound hydration water. These results could drastically affect the kinetics of the protein-corona, determining the fate of NPs during the BBB crossing.
Fudan University, China
Near-interface colloidal monolayers have often been used as model systems for research on hydrodynamics in biophysics and microfluidic systems. Using optical microscopy and multiparticle tracking techniques, the correlated diffusion of particles is experimentally measured in colloidal monolayers near a water-air interface. It is found that the characteristic lengths χǁ and χ⊥ of such a colloidal monolayer are anisotropic in these two perpendicular directions. The former (χǁ) is equal to the Saffman length of the monolayer and reflects the continuous nature of the system in the longitudinal direction. The latter (χ⊥) is a function of both the Saffman length and the radius of the colloids and reflects the discrete nature of the system in the transverse direction. This discovery demonstrates that the hydrodynamics intrinsically follow different rules in these two directions in this system.
Keywords: Hydrodynamics, liquid interface, colloid, characteristic lengths.
Biography:
Wei Chen completed his Ph.D and he working as a associate professor in Fudan University. His research interests are Philosophy of logic, philosophy of language; legal logic; argumentation theory and critical thinking; analytical Marxism; philosophy of the internet.
Universidad del Turabo, USA
Detection of ionizing radiation is crucial in different fields including energy, national security, biological and nuclear research, and other applications. In general, the systems for the detection of ionizing radiation usually have one or several of the following drawbacks: incapability to produce stable signals, expensive and complicated manufacturing processes, operation at low or very low temperatures, low sensitivity or even voluminous size, as is the case of Geiger counters. Single Walled Carbon Nanotubes (SWNTs) have attracted much interest for the design of advanced nanodevices, due to its excellent mechanical, optical, thermal properties and electrical conductivity. Among the possible applications, these materials can be successfully used as efficient ionizing radiation sensors. For this purpose, the critical steps in the design and fabrication of devices are focused on the growth of SWNTs into controlled architectures and onto appropriate substrates. In this research we report a method for the treatment of the silicon substrates with TiN and a mixture of Co and Mo salts as catalyst precursor for the synthesis of carbon nanotubes. XPS and AFM results show an appropriate distribution of the catalyst precursors on the Si surface. SWNTs obtained by this procedure have been used for the manufacture of a sensor prototype. As a result, this research shows the first data obtained when the prototype is exposed to increasing doses of radiation.
Biography:
Kenneth Fontanez graduated from an associate degree in Mechanical Engineering. He is a research student in Universidad del Turabo in Puerto Rico currently pursuing a bachelorʼs degree in chemistry with a record of 3 different investigations as well as an internship in Universidad Autonoma de Madrid (UAM).
Ronin Institute, USA
The fundamental nature of intrinsic inertia is interrogated within the conventional basis, relating the Landauʼs (1976) extraction of Galilean frame with no ambiguity made on Machian type.
Biography:
Bishal Banjara is an Independent researcher and Research scholar at Ronin Institute. A detail of my work and about my planning could be overviewed here at https://www.researchgate.net/profile/Bishal_Banjara as well in http://ronininstitute.org/research-scholars/bishal-banjara/.
National University of Kyiv, Ukraine
This paper deals with consideration of a new nuclear reaction type on 159Tb with a bound dineutron in the outgoing channel. The dineutron as a particle consisting of the two bound neutrons has been the target of scientific hunt for 70 years, since the very first publication of Colby and Little in Phys. Rev. in 1946. For decades a neutron-only nucleus was considered physically impossible. This paper presents results of experiments that report on the first statistically significant observation of an exotic state of nucleons, the long-sought dineutron, with conclusion that emission of the dineutron takes place in (p,2n+n) and (n,2n) nuclear reactions on 159Tb and represents a new type nuclear reaction in the output channel. The explanation of these experimental results is based on theoretical paper of Migdal from 1972 when the dineutron was predicted theoretically as a bound state of the two neutrons emitted from the nucleus through the mechanism of binding the two neutrons in one single particle near the surface, but outside a heavy nucleus such as 157Dy or 158Tb. Such a formation is possible due to the strong nuclear force from a heavy nucleus holding the two neutrons in close proximity for certain time. The dineutron is difficult to acquire and detect; therefore this problem has been solved by identifying a residual nucleus in the output channel of corresponding nuclear reaction. The dineutron may be only the very first evidence for existence of low nucleon bound systems composed of two or even three identical nucleons.
Biography:
Prof. Igor Kadenko has completed his PhD from Kiev State University, USSR/Ukraine and lately defended his doctoral thesis in Institute for Nuclear Researches, National Academy of Sciences of Ukraine. He is the Director of International Nuclear Safety Center of Ukraine and Head of Department of Nuclear Physics and Engineering of Taras Shevchenko National University of Kyiv, a leading educational organization in Ukraine. He has published more than 160 papers in reputed journals in fields of nuclear physics, high energy physics and nuclear engineering.
1National Institute for Laser, Plasma and Radiation Physics, Romania
2University Politehnica of Bucharest, Romania
3Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering, Romania
Bimetallic nanostuctures have the potential to become the new generation candidates for applications in catalysis, electronics, optoelectronics, biosensors, and surface-enhanced Raman Spectroscopy (SERS). The bimetallic nanocrystals could have additional properties over the single metal components.
This work presents the optimization process that was used in the fabrication of large area biplasmonic substrates employing picosecond laser pulses and a digital galvano scanner. Our aim was to achieve large area homogeneous substrates while having a good and predictable signal amplification by SERS effect. Silver thin films with different thickness were deposited on optical polished substrates and then irradiated with λ=1064 nm wavelength laser pulses with 8 ps pulse duration and 500 kHz repetition rate. Various laser fluences and laser irradiation speeds were employed in our experiments in order to optimize the Laser-induced periodic surface structures (LIPSS).
The results will be presented comparatively for laser processed bimetallic Al-Ag and raw Aluminium substrates.
Biography:
Mr. Andrei Stochioiu graduated Polytechnic University of Bucharest in 2017. His specialty is Electronics. From 2018 he is working as research assistant at Center for Advanced Laser Technologies (CETAL), National Institute for Laser, Plasma and Radiation Physics, Romania. His main research subject implies Raman Spectroscopy and its related applications.
The University of New South Wales, Australia
The generation of slow light by transient spectral hole-burning technique has been reported, based on the ground state population storage in the spin level of R1 line of Ruby at 2.1 K under low magnetic field. The population of these spin levels were then optically modulated and investigated the effect of slow light as well. The transient hole-burning involves the depletion of the ground state leading to a highly populated excited state by single frequency laser excitation. This lead to a hole in the absorption spectrum when readout by a laser. The experiments were conducted by burning hole at the R1 (±3/2) line ( 4A2 to 2E transition) of a 7.3 mm Czochralski grown ruby (30ppm) in a magnetic field of Bǁc = 8.8 mT. The observed delay was 13.4 ns correspond to a group velocity value of c/550. Besides, the spin level population of the R1 (±3/2) line was enhanced by applying a strong pump signal at R1 (±1/2) line and measured the delay of 37 ns corresponds to the group velocity of c/1523.
Biography:
Muhammed Ajmal Pallithadathil Nazer is a PhD student at the University of New south Wales Canberra since September 2015. His research is mainly focused on the generation of slow and fast light by spectral hole-burning in transition metal and rare earth ion doped systems. He holds master degree in opto-electronics and laser technology from Cochin University in India and bachelors in Electronics and communication engineering from Kerala University, India. He has experience in nanotechnology and the development of high power solid-state laser as well. He was an Assistant Professor and presently hold the position of webmaster in IEEE ACT section, Australia. He has attended several conferences in which he published three conference papers and presented four posters in his career.
University of Zaragoza, Spain
In this communication, two different statistical problems are presented under a same paradigm. Two discrete time operators governing the evolution of two different statistical problems, one of them that models the random trading of a collectivity of free economic agents and another one that models the classical problem of an ideal gas. The equilibrium distributions for both problems are the Exponential wealth distribution for the economic system and the Gaussian velocity distribution for the ideal gas. The motivation and the derivation of these models that can be seen as a discrete time alternative or extensions of the continuous Boltzmann equation are explained. (These works were made in collaboration with J.L. Lopez [ESAIM Proceedings, 36, 189-196, 2012] and E. Shivanian [Physica A, 391, 2600-2607, 2012], respectively).
Biography:
Ricardo Lopez-Ruiz, M.S., Ph.D., works as an Associate Professor in the Department of Computer Science and Systems Engineering, Faculty of Science, University of Zaragoza, Spain. He also serves as an Associate Researcher in Complex Systems at the School of Mathematics, University of Zaragoza, Spain. He has published over one hundred papers in journals, proceedings and books and he has presented about thirty talks at various meetings and conferences. His areas of interest include statistical complexity and nonlinear models, chaotic maps and applications, multi-agent systems, and econo-physics.
City College of the City University of New York, USA
Prior experimental results have shown that Type II Weyl semimetals have a Hall effect in the absence of a magnetic field. Therefore, we set out to investigate the electrical and thermal Hall conductivity of Type II Weyl semimetals. We found that Type II Weyl semimetals have a Nernst effect, as well as electrical and thermal Hall conductivity. We studied the linear response due to the electric field, thermal metric sensor and the momentum at the nodes, the latter acting as an axial anomaly. These three fields composed from the metric sensor, the axion momentum field and the electrical field determine the electrical and thermal Hall conductivity and Nernst effect. These findings represent the realization of the triangle diagram where the three fields are the axion momentum field, electric field and the metric sensor. Thus, we have shown that in type II Weyl semi-metals there is a quantum effect in the absence of a magnetic field.
1Poona College, India
2Abeda Inamdar College, India
Solar energy is turning out to be the most reliable energy source with its abundance and availability. Solar cells are thus assuming significance in the changing scenario. The efficiency of the solar cells is the most challenging factor in fabricating them. Attempts are made to improve the efficiency while capping costs and other environmental effects. Gratzel et al showed some promise in solar energy conversion by utilizing dye-sensitized solar cell (DSSC). Natural dye-sensitized solar cells (NDSSC), are also gaining importance for having good light harvesting pigments.. In our present work, we have used curcumin and aminothymoquinone as natural dyes. Both these dyes have good phototoxicity for bacterial film which shows promise against environment degradation. Electron transfer capability of these dyes changes with different solvents. It contains trace elements and most important form of calcium which is ionic calcium. The UV-Vis spectroscopy also yielded expected results which are described in the paper. Also curcumin has good anchoring with TiO2 semiconductors. The morphology surface roughness, absorption characteristics were studied. The cellsʼ photovoltaic cell performance was tested with standard illumination. For curcumin short-circuit current density (Jsc), open circuit voltage(Voc), Fill factor and Effeciency are 0.187 mA/cm2, 0.30V,0.36, 0.0259 % and for Aminothymoquinone it is, 2.27 mA/cm2. 0.54V 0.48, 0.71% respectively. The antioxidant properties of these dyes increase the scope for them (with different solvents) to be used in DSSC
Universidad de Guanajuato, Mexico
In this work, it was synthesized and characterized Lithium Borate Glasses doped with rare earths in different concentrations and containing Silver nanoparticles. The rare earths employed were Dy3+ and Yb3+. The Scanning Electron Microscope (SEM) show the formation of Silver nanoparticles, absorption spectra of the samples show the presence of bands in 420nm and 450nm associated with the SNP (Plasmon effect), and 750nm, 800nm, 875nm, 1098nm and 1278nm belonging to the Dy3+ and one large peak in 976nm belonging to the Yb3+. Emission spectra show two prominent bands in 480nm, 574nm, and one faint band in 665nm, all bands under 364nm pumping, and the fluorescence in the 550nm and 590nm spectral range enhanced two times. The TL response to UV irradiation was studied, the glow curve shows significant dependence of the TL intensity with the increment of the SNP in the samples.
Keywords: Thermolumninescence, Glasses, Silver nanoparticles
1University of Kent, UK
2University of Bristol, UK
Recent muon-spin relaxation experiments have found broken time-reversal symmetry (TRS) in a number of superconductors which from other points of view (such as specific heat, penetration depth, sensitivity to impurities etc.) appear to be conventional. We propose a novel superconducting groundstate where Josephson currents flow spontaneously between distinct, but symmetry-related, siteswithin a unit cell. Such Loop Josephson Current (LJC) state break TRS without the need for triplet, inter-site, or inter-orbital pairing i.e. they are compatible with a conventional BCS-type pairing mechanism. The Josephson currents result from a non-trivial phase difference between the on-site pairing potentials on different sites appearing spontaneously at the superconducting critical temperature. We show explicitly how such instability emerges in the Ginzburg-Landau theory of a simple toy model. We estimate the size of the resulting spontaneous magnetization and find it to be consistent with many existing experiments. We discuss the crystal symmetry requirements and apply our theory to the recently discovered family of TRS-breaking, but otherwise seemingly conventional, family of superconductors Re6X (X=Zr, Hf, Ti), showing the possibility of a LJC instability
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