Day 1 :
Keynote Forum
Shuji Nakamura
University of California Santa Barbara, USA
Keynote: The invention of high efficient blue LEDs and future lighting
Time : 09:00-09:30
Biography:
Shuji Nakamura was born on May 22, 1954 in Ehime, Japan. He obtained B.E., M.S., and Ph.D. degrees in Electrical Engineering from the University of Tokushima, Japan in 1977, 1979, and 1994, respectively. He joined Nichia Chemical Industries Ltd in 1979. In 1988, he spent a year at the University of Florida as a visiting research associate. He is the 2014 Nobel Laureate in Physics for the invention of efficient blue light-emitting diodes, which has enabled bright and energy-saving white light sources. Prof. Nakamura received the 2014 Order of Culture Award in Japan. Since 2000, he has been a professor of Materials and Electrical & Computer Engineering at the University of California, Santa Barbara. He holds more than 200 US patents and over 300 Japanese patents. He has published over 550 papers in his field. Prof. Nakamura is the Research Director of the Solid State Lighting & Energy Electronics Center and The Cree Chair in Solid State Lighting & Displays. He co-founded Soraa, Inc. in 2008, which operates vertically integrated fabrication facilities in California’s Silicon Valley and Santa Barbara.
Abstract:
In 1970's and 80’s, an efficient blue and green light-emitting diodes (LED) were the last missing elements for solid-state display and lighting technologies due to the lack of suitable materials. By that time, III-nitride alloys was regarded the least possible candidate due to various "impossible" difficulties. However, a series of unexpected breakthroughs in 1990's totally changed people's view angle. Finally, the first high efficient blue LEDs were invented and commercialized simultaneously in 1993. Nowadays, III-nitride-based LEDs have become the most widely used light source in many applications. The LED light bulbs are more than ten times efficient than incandescent bulb, and they last for 50 years. At their current adoption rates, by 2020, LEDs can reduce the world’s need for electricity by the equivalent of nearly 60 nuclear power plants. The history of the invention of blue LED and future lighting will be described.
Keynote Forum
Yukio Tomozawa
University of Michigan, USA
Keynote: Masses of black hole merger for the gravitational waves, GW150914
Time : 09:30 -10:00
Biography:
Yukio Tomozawa obtained D.Sc. in 1961 from Tokyo University. He was Assistant Researcher at Tokyo University (1956) and at Tokyo University of Education (1957-1959) - Member at the Institute for Advanced Study, Princeton, NJ (1964-1966). He was Assistant Professor, Associate Professor, Professor and Emeritus Professor at the University of Michigan, USA. He found that the Schwarzschild metric does not fit the data of time delay experiment in the field of general relativity. He has introduced a physical metric which fits the data. It was constructed with the constraint that the speed of light on the spherical direction is unchanged from that in vacuum. This modification changes the way we understand the nature of gravity drastically. In particular, the nature of compact objects, neutron stars and black holes, is very different from that described by the Schwarzschild metric. It also explains the dark energy, supernova explosion and high energy cosmic ray emission from AGN (Active Galactic Nuclei), massive black holes.
Abstract:
The author starts from the experimental test of General Relativity on time delay in the solar system by Shapiro et al. The most recent experiment using the Cassini satellite attained an 1 in 10^5 accuracy level. This indicates that the Schwarzschild metric is not a correct metric and the correct metric is the author’s physical metric, in which the speed of light on the spherical direction is constrained to be the value in vacuum. This is a conceptually natural assumption, since the spherical direction is perpendicular to the radial direction which is the direction of the gravity. In this new metric, the size of compact objects, neutron stars and black holes, becomes 2.60 times larger than that of the Schwarzschild radius and is called the extended horizon. The temperature of compact objects is found to be very high, as is evidenced from the existence of highly ionized atoms in the X-ray measurement of compact objects. In this metric, both the point source and a constant density distribution, the internal solution inside the extended horizon is shown to be a repulsive gravitational force, while the gravity outside the extended horizon remains attractive. The repulsive nature of gravity inside the extended horizon is the source for the supernova explosion as well as the reason for high energy cosmic rays generated from AGN, Active Galactic Nuclei, which are massive black holes. Using the physical metric in General Relativity, the author suggests that the masses of the merging black holes which produced the gravitational waves in LIGO, GW150914, must be reduced by a factor of 2.60. The masses of the merging black holes are 11.2 (+1.5, -1.5) M_{⊙} and 13.8 (+1.9, -1.5) M_{⊙} and the final mass of the resulting black hole is 23.8 (+1.5, -1.5) M_{⊙}. These masses of the merging black holes are consistent with the observed values of black hole masses.
Keynote Forum
Alejandro Martin Sanchez
University of Extremadura, Spain
Keynote: Spectrometric characterization techniques applied to artworks belonging to the historic and cultural heritage
Time : 10:00 -10:30
Biography:
Alejandro Martin Sanchez is currently working at the University of Extremadura, Spain. He has completed his studies at the Autonomous University of Madrid, Spain. He was the Head of the Physics Department for 12 years. He has published more than 100 papers in the most reputed journals about environmental radioactivity and nuclear physics.
Abstract:
The development and application of the spectrometric techniques to the cultural heritage provides an increasingly knowledge of human behavior. X-ray fluorescence (XRF), X-ray diffraction (XRD), Raman spectrometry, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) among others have become very useful for the application to the characterization of pigments used in artworks, such as paintings, frescos, rupestrian pictures, sculptures, vellum inks, etc. In this work, some results obtained by a portable XRF device, assembled in our laboratory a few years ago, are presented. This technique identifies the chemical elements forming the surface shells of a sample and is neither destructive nor aggressive i.e., samples are not damaged in the analysis procedure nor previous treatment is necessary. Characterization of pigments coming from a wide range of material such as glazed ceramic pots, rock art, modern paintings, ancient parchment and Roman rests were studied with XRF. Extremadura is a region were the Roman culture has a prevalent importance and some places are now included in the World Cultural Heritage catalogue by UNESCO. In the case of pieces coming from the recent found Roman theater of Medellin (Badajoz, Spain) and from a near noble house, results from XRD and SEM techniques were also used to clarify the materials used in the buildings and in their decoration. All the techniques used help to classify and catalogue the corresponding artworks and they have been revealed as very useful tools for archeologists and curators in their works.
Keynote Forum
Chong Wei Xu
Verizon Communications, USA
Keynote: Scientific philosophy to unified physics
Time : 10:30 -11:00
Biography:
ChongWei Xu, a Chief Architect at Verizon Communications USA, focus on dialectical nature of philosophy and sciences is to uncover topological framework of the universe, to develop a full intrinsic structure of the entire elementary particles, to derive the duality principles of spacetime manifolds, to present the unified physics under a horizon topology, and to heuristically demonstrate the origin of physical states. Since 2013, he has demonstrated the enlightenments of groundbreaking theories in Particle Physics and Unified Physics.rnMr. Xu holds the BS and first MS degrees in physics from Ocean University of China and Tongji University, and the second MS degree in electrical and computer engineering from University of Massachusetts.
Abstract:
The keynote speech presents philosophical overview of scientific methodology and essential achievements in our recent groundbreaking: Unified Field Theory. A critical reevaluation of our knowledge and vision is the start of a new way to a new era, the revolution of Unified Physics and the return of philosophy. Our generation has been furnished with groundwork enlightenment of the demonstrated theories of our universe: Space time topology of physical and virtual existences, revealing scientific truth for all physics according to concise, systematic, philosophical and mathematical principles. The applications of the evolutionary processes to contemporary theoretical physics derive a complete picture of the principal equations, important assumptions, empirical equations and essential laws for both classical and modern physics including quantum mechanics’, thermodynamics, electromagnetism, general relativity, gravity and classic dynamics. The year 2015, therefore, bids farewell to an intellectual age of classical physics defined by mathematical empiricism from Newton's Mechanics of 1687 to Einstein’s Relativity of 1915 and from Quantum Theory of 1920s to contemporary physics.
- Track 1: Physics
Track 2: Condensed Matter Physics
Location: Salon 3
Chair
Shuji Nakamura
University of California Santa Barbara, USA
Co-Chair
Guang-Lin Zhao
Southern University and A&M College, USA
Session Introduction
George Rawitscher
University of Connecticut, USA
Title: Revival of the phase-amplitude description of a quantum-mechanical wave function
Time : 11:20-11:45
Biography:
George Rawitscher received his BS degree in Physics and Mathematics at the University of Sao Paulo, Brazil in 1949, and his PhD in Physics from Stanford University in 1956. After serving as the faculty at Yale University, he moved to the University of Connecticut where he taught for more than 40 years as Full Professor. He is now Research Professor at the University of Connecticut since 2009, continuing to do research, and is presently co-authoring a book on spectral computational methods.
Abstract:
The Phase-Amplitude (Ph-A) description consists in writing the wave function as Ï•(r)), where y is the amplitude and Ï• the phase. Both functions vary slowly with the distance r, and hence should be easier to calculate than the highly oscillatory function . In 1930, W. E. Milne established the second order differential equation for y(r), which unfortunately is non-linear, and hence cumbersome to solve with the conventional finite difference methods. In 1962, M. J. Seaton and G. Peach demonstrated an iterative solution of Milne's equation, and in 2015 and 2016 the present author improved the iterative method by making use of a modern spectral expansion procedure of y(r) in terms of Chebyshev polynomials. The method is very economical and fast, as will be shown. One drawback of the iterative method is that it does not converge in the vicinity of the turning points. It is possible that this difficulty can be overcome by considering an alternative third order linear differential equation which may propagate the solution across the turning points. Attempts to solve this equation numerically will be described. If successful, that may represent an important advance for the Ph-A description.
Guang-Lin Zhao
Southern University and A&M College, USA
Title: The puzzle of anomalous isotope effect in high and low Tc superconductors
Time : 11:45-12:10
Biography:
Guang-Lin Zhao has completed two doctorate programs; first Doctor of Science degree in Low Temperature and Solid State Physics at the Institute of Physics, Chinese Academy of Sciences, Beijing, China and second PhD degree in Condensed Matter Physics at Iowa State University, Ames, Iowa, USA. He is currently a Professor of Physics at Southern University and A&M College, Louisiana, USA. He has published more than 100 research papers in reputed research journals and has been serving as a manuscript referee for nineteen professional research journals.
Abstract:
Superconductors have zero electrical resistance and expulsion of magnetic fields below a critical temperature Tc. They can carry electric current without any energy loss and have many applications. However, understanding superconductivity is a great challenge. Especially, anomalously small isotope effect in some high Tc superconductors such as YBa2Cu3O7 (YBCO) created a great challenge for understanding. To solve the puzzle, a new methodology is implemented by integrating first-principles calculations of electronic structures of the materials into the theory of many-body physics for superconductivity. The aim is to seek a unified methodology to study the electronic and superconducting properties of the materials. It is demonstrated from first-principles that the extended saddle point singularities in the electronic structure of some high and low Tc superconductors such as YBCO, Nb3Sn, Zr, strongly correlate with the anomalous isotope effect in these superconductors. Some guidance for finding new high Tc superconductors will also be discussed.
Firouzeh Sabri
Universtiy of Memphis, USA
Title: Effect of triboluminescent and thermographic phosphor powders on the thermal, mechanical, and optical properties of elastomeric composite materials
Time : 12:10-12:35
Biography:
Firouzeh Sabri completed PhD in 2002 from the Cavendish Laboratory-Microelectronics and Semiconductor Physics Group. She has completed a Post-doctoral fellowship at NIH/NIDCD in biophysics and a second Post-doctoral fellowship in Polymer Chemistry at UF, Gainesville. She is an Associate Professor and the Director of the MemphisCRESH summer research internship program, at the Universtiy of Memphis. She is the recipient of the 2008 APS Hildred Blewett Award. She is the founder of the Bio, Nano, and Space Materials Laboratory at UoM.
Abstract:
In this study, photoluminescent, triboluminescent, and thermal response of elastomer-encapsulated thermographic phosphor powders and triboluminescent powders were investigated and will be reported. The effect of the additives at concentration levels of 5, 15, and 50% on the mechanical, thermal, and optical properties of Sylgard-184 elastomer was investigated, at room temperature and compared with the behavior of the neat polymer. Furthermore, the effect of polymer encapsulation on the emission and excitation characteristics of the powders was also investigated and fully characterised. Composite polymer samples containing different concentrations of select powders were prepared by combining Sylgard-184 (10:1 base to cross-linker ratio) with the approriate powder, mixed gradually, and then completely outgassed at room temperature and fully cured at 100 C for 1 hr. The results demonstrated a non-linear relationship between the powder concentration and the output intensity. The composite samples were also created in thin films by implementing a spin-coating technique before the outgassing and curing stage. The results of the dropcasting method were compared with the spincoated samples and fully characterised. Results of the mechancial, thermal, and, optical properties of all composite samples will be reported.
Biography:
A thickness dependence study of polymer based light-emitting diodes spanning from 31 nm to 3 um shows that devices with micron-thick films of semiconducting polymers (ten times thicker than the standard devices) had the best performance, which is exceptionally thick for PLEDs. The efficiency of 47cd/A is higher than the theoretical prediction according to spin statistics. Transient studies reveals that high current density introduced by the Ohmic hole injection of MoO3 at anode promote triplet-triplet annihilation and results in delayed electroluminescence. Hence, singlet formation is no longer 25%, but actually approaching 40%. This research shows the power of interface engineering in making efficient single layer devices, which has been the Holy Grail for the organic electronics community. This is very important for industrialization of this technology - e.g. in lighting, where the reduced manufacturing tolerances make large area manufacturing far more practical. This work represents a literal step change in the previous requirement that PLEDs be very thin and proved to be the model system for the study of polymer based LEDs.
Abstract:
A thickness dependence study of polymer based light-emitting diodes spanning from 31 nm to 3 um shows that devices with micron-thick films of semiconducting polymers (ten times thicker than the standard devices) had the best performance, which is exceptionally thick for PLEDs. The efficiency of 47cd/A is higher than the theoretical prediction according to spin statistics. Transient studies reveals that high current density introduced by the Ohmic hole injection of MoO3 at anode promote triplet-triplet annihilation and results in delayed electroluminescence. Hence, singlet formation is no longer 25%, but actually approaching 40%. This research shows the power of interface engineering in making efficient single layer devices, which has been the Holy Grail for the organic electronics community. This is very important for industrialization of this technology - e.g. in lighting, where the reduced manufacturing tolerances make large area manufacturing far more practical. This work represents a literal step change in the previous requirement that PLEDs be very thin and proved to be the model system for the study of polymer based LEDs.