The Department of Physics of the School of Science and Engineering of Ateneo de Manila University cordially invites you to a Ph.D. in Physics Dissertation Defense by Amante T. Ama on Wednesday, May 6, 2:00 PM (ONLINE). His dissertation is entitled, “Radially polarized Bessel beams,” under the supervision of Raphael A. Guerrero, Ph.D. His dissertation panel members are Dr. Alvie Astronomo (PNRI), Dr. Joel Maquiling (Physics), Dr. Jose Mario Diaz (Chemistry), Dr. Ramon Delos Santos (Physics).
Abstract
A radial polarizer prepared by growing a thickness-constrained spherulite from an oleoresin polymer is presented. As an insert between crossed linear polarizers, the fabricated device is used to alter the intensity profile of an incident zero-order Bessel beam. Radially polarized output beams have an intensity profile with a pronounced singularity at the center. Beams may be rotated by a simple reorientation of the crossed polarizers. Experimental results with our radial polarizer correspond to a transformation of the Bessel beam order from l = 0 to l = 2.
The Department of Physics of the School of Science and Engineering of Ateneo de Manila University cordially invites you to a Ph.D. in Physics Dissertation Defense by Dominic P. Guana on Wednesday, November 6, 2019, 5:30 PM at Faura Hall, Room F-106. His dissertation is entitled, “Generation of a Zeroth-order Elliptical Bessel Beam with a Deformable Annular Slit,” under the supervision of Raphael A. Guerrero, Ph.D. His dissertation panel members are Dr. Alvie Astronomo (Philippine Nuclear Research Institute), Dr. Marienette Vega (UP Diliman), Dr. Jose Mario Diaz (Chemistry), and Dr. Ramon Delos Santos (Physics).
Abstract. Elliptical Bessel beams are produced from an elastomeric annular slit under applied strain. Generated beams are observed to possess a self-healing property and are quasi-resilient to diffraction in the far-field. A Fourier transform approach effectively predicts the elliptical Bessel beam profile for large propagation distances. The results obtained in this study could potentially contribute to advancements in atom optics, matter-wave microscopy, ultrafast volume structuring and quantum communications.
The Solid Earth Dynamics / Upper Atmosphere Dynamics Laboratory of Manila Observatory and the Department of Physics of the School of Science and Engineering of Ateneo de Manila University cordially invites you to the talk “Environmental Sounding for Earth-Space Environment Science” by Dr. Terrence Bullet on Wednesday, 23 October 2019, 10;00-11:00 AM at Heyden Hall, Manila Observatory. Dr. Terrence Bullet is a Research Associate of the University of Colorado Cooperative Institute for Research in Environmental Sciences (CIRES) and the Chief Engineer of the World Data Center A Ionosonde Program.
Abstract
The ionosphere is a layer of ionized plasma created by solar Ultraviolet light, at a height of 60km to over 1000 km. As an ionized plasma, the ionosphere strongly interacts with radio waves, allowing long distance shortwave radio communication and disrupting radio waves between satellites and the ground, such as the GPS navigation system in everyone’s phone. The ionosphere is also an easily detectable trace plasma in the Earth’s thermosphere, the upper layer of the atmosphere through which all energy entering or leaving Earth must pass.
Ionosondes are radar instruments that measure the ionosphere. They are the first radar systems, dating back to the 1920’s. The Manila Observatory has operated such an instrument since the 1950’s. A new digital receiver ionosonde is just installed at Manila Observatory. This new instrument, the Vertical Incidence Pulse Ionosphere Radar or VIPIR, is built for scientific discovery and is used in the US, South America, Japan, Korea and Antarctica.
About the Speaker
Dr. Terrence (Terry) Bullett
Research Associate, University of Colorado Cooperative Institute for Research in Environmental Sciences
Chief Engineer, World Data Center A Ionosonde Program
My primary career interest is making observations with ionosondes and their application to solve scientific and engineering problems of radio wave propagation in the ionosphere and to study space weather and space climate. Over the last 30 years, I have installed or upgraded almost three dozen ionosondes around the world.
I started this adventure at the University of Massachusetts Lowell, where I obtained my BS in Electrical Engineering (1984), MS in Radar Systems Engineering, and eventually my Doctorate of Engineering by measuring ionosphere plasma motions with ionosondes. I was hired by the US Air Force Research Laboratory in 1989 and soon lead their ionosonde program. This afforded me to experience all aspects of ionospheric sounding, including instrument design, antenna design, installation, operation, data analysis, and use of real time data for applications such as HF propagation and ionospheric forecasting. I also obtained familiarity with numerous other ionosphere sensing techniques, including space-based sensors, space-based beacons, ground based radars and especially sounding rockets. I have supported 12 sounding rocket launches with ionosonde data.
In 2000 I started and lead a project to create a new generation ionosonde with modern technology. This has developed into the Vertical Incidence Pulsed Ionospheric Radar (VIPIR) which first operated in 2006 at Wallops Island, USA. This MF-HF radar is oriented toward research and discovery. With 20 instruments now operating and another 10 in various planning stages, the discoveries from the owners of these instruments are just starting to be published.
In 2007, I joined the World Data Center ionosphere group as Chief Engineer, where I now work in cooperation with NOAA, promoting real time space weather and long term space climate data collection worldwide.
My current interests include operating and improving a small network of ionosondes in the US, improving the quality of data from all types of ionosondes, antenna design, preservation of the long-term climate record of ionosonde observations, real time international data exchange, multi-sensor ionospheric studies, open source software development and teaching the next generation of ionosonde scientists. I am a General class radio amateur operating under the call sign W0ASP in the US and HL2JDM in Korea.
My recent volunteer efforts include being the Chief Scientist for the Radio Astronomy program at the Little Thompson Observatory in my home town of Berthoud, Colorado. This all-volunteer group teaches astronomy to all ages. Our radio telescope has measured the temperature around the black home at the center of our galaxy.
Top: Dr. Terry Bullet, Dr. Justin Mabie, and Clint Bennett installing an ionosonde receiver. Botom left: Dr. Terry Bullett with the ionosonde computer. Bottom right: Ionosphere Research Building at Manila Observatory.
The Department of Physics of the School of Science and Engineering of Ateneo de Manila University cordially invites you to a Ph.D. in Physics Dissertation Defense by Rayno Vic B. Janayon on October 21, 2019, 5:00 PM at Faura Hall, Room F-106. His thesis is entitled, “Laser irradiation of Vigna Radiatia L. (Mung Bean) at two wavelengths: effects on seedling development,” under the supervision of Raphael A. Guerrero, Ph.D. His dissertation panel members are Roland Caballar, Ph.D. ( Quirino Memorial Medical Center), Ramon Delos Santos, Ph.D. (Physics), Joel Maquiling, Ph.D. (Physics), and Vivian Panes, Ph.D. (Biology) .
Abstract. The use of lasers in agriculture has led to improved growth and development of crops and vegetables, increasing production and ensuring food security. In this study, two laser sources operating at wavelengths of 632.8 nm (He-Ne) and 488 nm (Ar+) are used in examining the effects of coherent, low-power, continuous wave exposure on the development of mung bean (Vigna radiata L.) at an early stage. Pre-sowing laser irradiation of seeds leads to an improvement of mung bean seedling characteristics, with increased values of hypocotyl length (an increase of up to 22.5%), root length (an increase of up to 28.8%), and seedling mass (a maximum increase of 29.2%). Measured parameters between seedlings from laser-irradiated seeds and from control samples are statistically different at a level of significance equal to 0.05. For both laser wavelengths, an optimal exposure time of 2 minutes is determined for enhanced growth of mung bean seedlings. The findings of this dissertation research may be used to facilitate an increase in Philippine mung bean production.
The Department of Physics of the School of Science and Engineering of Ateneo de Manila University cordially invites you to an open talk entitled High Energy Efficiency Solid-State Optoelectronic Devices based on III-Nitride Semiconductor Materials by Dr. Ryan G. Banal to be held at F106, Faura Hall, Ateneo de Manila University on Friday, 20 September 2019. 5:00 PM,
Abstract
The use of conventional light sources such as incandescent bulbs and fluorescent lamps for general lighting and sodium vapor and halogen lamps for street lighting are still being widely used in the Philippines. These conventional light sources consume not only large amount of energy (high-power consumption), they are also less efficient and have short lifetime. They therefore contribute to the high energy consumption and huge economic losses. With an increasing energy demand due to high population growth and economic activities amidst the depletion of non-renewable energy resources, there is a need to utilize our energy resources effectively and efficiently.
In this presentation, I will discuss the various benefits of using high-efficiency optoelectronic devices for solid-state lighting. These device technologies include light-emitting diodes (LEDs) and laser diodes (LDs). The important breakthroughs in this research area will be introduced, including the important role of the III-Nitride semiconductor materials, which are aluminum nitride (AlN), gallium nitride (GaN), indium nitride (InN) and their ternary alloys (AlGaN and InGaN) for the realization of these technologies. The author’s contribution to the advancement of scientific knowledge in this research area will also be presented. Finally, the current challenges and future research directions using these semiconductor materials will be discussed.
About the Speaker
Dr. Ryan G. Banal is a DOST Balik Scientist Program awardee. He obtained his Doctor of Engineering degree at Electronics Science and Engineering, Kyoto University, Japan. He is currently an assistant manager at Sumitomo Electric Industries, Inc. at Itami-shi, Japan. He is an expert in AIGaN/AIN/InN electronic device manufacturing through chemical vapor deposition (CVD) processes, and semiconductor characterization.
Department of Physics
3/F Faura Hall, Ateneo de Manila University, Katipunan Ave., Loyola Heights, Quezon City, 1108 Philippines
Tel No.: (632) 426-6001 loc. 5690/5691
Fax No.: (632) 426-1043
E-mail Address:
physics at admu dot edu dot ph.
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