Interview with Dr. Chetan Dhital

In our effort to highlight Nepali physicists, we are inviting recent physics-PhD graduates. We congratulate Dr. Chetan Dhital for defending his PhD in Physics. Presenting a brief interview with him.

First of all, thank you Nabin jee for your time and effort.

Q. Please tell us about yourself. (Nepal School, Masters experience and travel to PhD institutions. Did you teach? Also any links, personal websites, and a photo etc.)

I was born in Bahundangi, a remote village in Jhapa, Nepal. I passed SLC from a government school near my village. When I passed SLC, my goal was to become a B.Sc. teacher so I joined I. Sc. in MMAM Campus Biratnagar where I finished both I. Sc. and B.Sc. After finishing B.Sc., I taught in a boarding high school for about 1 year. During that one year I changed my mind and went to Kathmandu to study M. Sc. in physics. I started to realize the beauty and importance of physics during those four years of my Master study. After finishing M.Sc, I taught undergraduate physics courses in Damak Multiple Campus Damak, Jhapa Nepal for about 3 years. In 2008, I got the opportunity to come to Boston College for pursuing Ph.D. in physics.

Q. Could you please describe your PhD research in plain English.  

My work during Ph.D is more about the fundamental physics which may not have direct immediate application. I worked mainly on two systems (1) Oxides of Iridium (2) Iron based superconductors. My work is focused in understanding different exotic electronic/magnetic phases in these materials by measuring electrical transport, magnetization and neutron scattering techniques.

Wait: why exotic?

In a hand waving argument, if one tries to confine charged particles in a small volume then charges experience mutual electric repulsion which blocks their movement resulting in an insulator so called Mott insulator. If the charges are allowed to stay inside a larger volume, they can avoid strong repulsion and may result in conducting states if the volume (band) is half filled. This is main theme of conventional band theory. In a solid the charged particles are electrons and the volume is the orbital occupied by electrons. If we believe the above picture and take the particular examples of Sr₃Ru₂O₇ and Sr₃Ir₂O₇, we should expect more metallic behavior in Sr₃Ir₂O₇ than that in Sr₃Ru₂O₇ because 5d orbitals of iridium are more extended than 4d orbitals of ruthenium. But the reality is opposite i.e Sr₃Ir₂O₇ is insulator and Sr₃Ru₂O₇ is a metal. In fact most of the oxides containing iridium in its 4⁺ valence state show such deviation from conventional wisdom. This is why they are exotic. Here the major player is spin-orbit interaction strength in iridates which is not just a perturbation term as in 3d compounds. Thus iridates (oxides of iridium) host many exotic quantum phases like spin liquid, quantum spin ice, Mott-insulators etc. We map out the electronic/magnetic phase behavior some typical doped and parent iridates. Regarding the second project, the key question in high temperature superconductivity is the mechanism responsible for superconductivity. In iron-based superconductors, the superconducting transition is always preceded by crystal and magnetic structural transition. My study is focused in understanding the structural and magnetic phase behavior of the electron doped superconducting system via neutron scattering.

Q. What are the social applications of your research/ short-term or long-term impact of your research to the society?

As I already mentioned, they may not have direct social impact. However, as we know transition metal oxides are also called functional materials, which have very good thermal and chemical stability allowing their use over a wide range of temperature and different chemical environments. In fact modern day electronics are based on transition metal oxide devices. The properties of these oxides are governed by the interplay of different competing energy scales. More players mean more ways of tuning the properties of these functional materials.
I think I do not have to say anything about the social/economic impact of high temperature superconductor (I wish we had room temperature superconductor) in this fast paced world where we are severely lacking our energy demand. But, to know the superconductivity better, one has to know ‘what was there at high temperature that becomes superconductor at low temperature’. My research is about “what was at high temperature”?

Q. How was your graduate school experience? (Specifically in terms of preparations towards your PhD, awards etc. Which skill(s) in particular you needed to sharpen, skills that you already had from previous institutions etc.)

In my view, the graduate study in USA is more student centered and practical. However, the courses we took in Master level especially the solid-state physics courses were very helpful. For my case, the graduate study period was satisfactory. I had the opportunity to perform several experiments in different national laboratories around the world. I think the productivity depends up on several factors such as your devotion and interest in the work, your relation with PhD advisor, your field of study etc.
In my case, there was a good combination of all these factors. I was awarded with GMAG student dissertation award from American Physical Society. This award is given every year for 2 or 3 graduate students working in magnetism who are going to graduate within September of that year. The student has to be a member of GMAG unit in APS and should be nominated by his advisor. There are some other awards that are also included in the following link.
http://www.aps.org/units/gmag/newsletters/upload/february14.pdfI also authored/coauthored about 16 peer reviewed journals which can be found in the following link:
http://scholar.google.com/citations?user=hEbr_o4AAAAJ&hl=enIf you are working in Neutron scattering then there is a website for Neutron scattering society of America which provides information about awards and conferences.http://neutronscattering.org/

Q. Please share few useful tips that you wish you were told when you applied for PhD.

To be honest, I was not fully aware of American style when I applied for graduate program. I used to write email to office secretary rather than professors or graduate advisor, which was a big mistake. Here, one can directly write to graduate advisor without any hesitation. Nowadays, the access to internet is easier than the time I applied, so one can easily find the departments that match with his research interest. Although our interest does not always work, however, I would suggest giving priority to those departments where your research interests match.  If you have two options, then money should not be the primary factor for decision-making. Furthermore, familiarize yourself with some common programs like matlab, origin, mathematica, igor etc before coming here. I think there should be a computational course at least in master level physics.

Q. Where do you want to be in the next 5 years? What are your hobbies, and spare time activities?

For the next step, I am joining as a postdoctoral research associate in Oak Ridge National Laboratory.  My next step is to give a shot for research faculty in suitable graduate schools (You miss 100% of the shots you don’t take,). If that doesn’t work, I want to stay in some suitable research and development department. However, I like to say “it is life”.
If you have kids then definition of spare time becomes vague. However, if I have time then I know how to watch basketball, soccer and cricket. I also enjoy watching comedy programs and movies and of course Nepal and world news.

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Presenting in Machine Learning Conference in NYAS today

Creating High-Resolution Climate Meteorological Forecasts by Application of Machine Learning Techniques

Nabin Malakar, PhD, Emmanuel Ekwedike, BS, Barry Gross, PhD, Jorge Gonzalez, PhD, and Charles Vorosmatry, PhD

The City College of New York, New York, New York, United States;

In order to study the effects of global climate change on a regional scale, the low resolution GCM forecast data needs to be intelligently adapted (downscaled) so that it can be injected into high resolution models such as terrestrial ecosystems. Our study region is the North East domain [{35N, 45N} x {-85W,-65W}]. In particular, we focus on High and Low temperature extremes within the Daymet data set, while the low resolution climatology (at 0.5 deg) MET data are obtained from the The Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP) climatology forecast database.  Although the injection of regional Meteorological Models such as Weather Research and Forecasting (WRF) can be attempted where the GCM conditions and the forecasted land surface properties are encoded into a future time slices, this approach is extremely computer intensive. We present a two-step mechanism by using low resolution meteorological data including both surface and column integrated parameters, and then by combining high resolution land surface classification parameters to improve on purely interpolative approaches by using machine learning techniques. 

Application of Machine-Learning for Estimation of PM2.5 by Data Fusion of Satellite Remote Sensing, Meteorological Factors, and Ground Station Data

Lina Cordero, MS, Nabin Malakar, PhD, Yonghua Wu, PhD,  Barry Gross, PhD,  Fred Moshary, PhD

Optical Remote Sensing Laboratory, CCNY, New York, New York, United States;

Particulate matter with dimension less than 2.5 micrometers (PM2.5) can have adverse health effects. These particles can enter into the blood streams via lungs, reach vital organs and cause serious damages by oxidative inflammations. We present our latest progress in obtaining correct estimates of PM2.5 on regional scale by using machine learning techniques. Specifically, we apply a neural network method for better describing the non-linear conditions surrounding the PM2.5-MODIS AOD while at the same time investigating dependencies on additional factors or seasonal changes.  In our local test, we find very good agreement of the neural network estimator when AOD, PBL, and seasonality are ingested (R~0.94 in summer). Next, we test our regional network and compare it with the GEOS-CHEM product. In particular, we find significant improvement of the NN approach with better correlation and less bias in comparison with GEOS-CHEM. We also show that further improvements are obtained if additional satellite information and land surface reflection, is included. Finally, comparisons with Community Multi-scale Air Quality Model (CMAQ) PM2.5 are also presented.

Using NN techniques to ingest Meteorological Weather Satellite data in support of Defense Satellite Observations

Crae Sosa, BS, Gary Bouton, MS, Sam Lightstone, MS, Nabin Malakar, PhD,  Barry Gross, PhD and Fred Moshary, PhD

The City College of New York, New York, New York, United States;

The need to observe thermal targets from space is crucial to monitoring both natural events and hostile threats. Satellites must choose between high spatial resolution with high sensitivity and multiple spectral channels. Defense satellites ultimately choose high sensitivity with a small number of spectral channels. This limitation makes atmospheric contamination due to water vapor a significant problem which can not be determined from the satellite itself. For this reason, we show how it is possible to ingest meteorological satellite data using NN to allow for the compensation of water absorption and re-emssion in near-real time

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To Aspiring students looking into a PhD program

It is nice to hear about your aspirations for a PhD. I wish you all the best!

Since my background is in physics, do not be surprised if my information turns out to be different.

I recommend that you start with the following:
1. TOEFL, GRE, subject GRE requirements.
2. A short list of universities that you would like to go, and why?

Seniors and professors may be your resources for your way into these.
3. Learn about the required supporting documents such as letter of recommendation, copies of original transcripts, application fees etc to the office of graduate admission.

Once you have figured these requirements, you will know a lot on how to proceed.

Then the usual way is to send in the applications, and supporting documents. Do inquire to the admission office to learn about the appropriate procedure.

All the best! 

The following links might be useful:

http://www.nabinkm.com/2008/12/tips-for-nepali-students-applying-to.html

http://www.nabinkm.com/2012/05/student-j-1-visa-usa-international.html

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Interview with Dr. Narayan Chapagain

We are presenting an interview with Dr. Narayan Chapagain. His successful journey from the remote village of Syangja to USA has taken another leap to Nepal. He has returned to the Associate Professor of Physics position in the Tribhuvan University, with international exposure, experience and a great motivation to uplift the research activities in Nepal. He is recipient of the prestigious NASA heliophysics Jack Eddy Postdoctoral Fellowship award and author of several research papers and books.


0. Congratulations on being elected the editor of NPS. Could you please tell us a little bit about yourself? (Where did you grow up, where and when you studied etc.) Your research interest and website/URL/Linkedin etc.

Thanks Nabin ji.
I was born in a remote village from Syangja district. I had to move around 5 hours walking distance away from my village for elementary and middle school. I completed my high school from Palpa district. For the college education, I moved to Kathmandu and I completed my I.Sc. and B.Sc from Trichandra College and M.Sc. in Physics from the Central Department of Physics, Tribhuvan University. Since then, I joined as a faculty member in Physics at Patan M. Campus. I got a scholarship to study Post Graduate Courses in Space and Atmospheric Sciences organized by Centre for Space Science and Technical Education in Asia and the Pacific (CSSTE-AP) affiliated to the United Nations. I completed my Postgraduate Diploma from Physical Research Laboratory (PRL), Ahmedabad, and Master in Technology (M.Tech.) in Space and Atmospheric Sciences from Andhra University, India in 2003. In 2005, I moved to United States to peruse my further education and completed my Ph.D. in Space Physics in 2011 from Utah State University, UT, USA. I won the very prestigious Jack-Eddy Postdoctoral Fellowship Award sponsorship by NASA Living With a Star Helliophysics Program in a host institute at the Department of Electrical and Computer Engineering at University of Illinois at Urbana-Champaign, USA. After my two years of postdoctoral research experiences, I returned to my home institute, Tribhuvan University, Nepal in 2013 and I have been continuing my faculty position as an associated professor in Physics.

During my M.Sc., I was involved in theoretical research work in Plasma Physics while in my M.Tech. degree, I worked on analysing the ozone data over Kathmandu measured by both ground- and space-based observations. My present research is focused on electrodynamics of thermosphere-ionosphere, especially low-latitude ionospheric irregularities and its coupling effects on neutral dynamics. I have used optical imaging data, radar and satellite observations and modelling works as well. The webpage indicating of my activities are as follows:
url:
http://www.vsp.ucar.edu/Heliophysics/post-about-participating.shtml
http://airglow.csl.illinois.edu/People/Narayan

1. How did you decide to study physics? Did anyone, in particular, influence you?

Physics was one of my favourite subjects during my I.Sc. classes. My determination to study Physics as my future career intensely augmented during my B.Sc. course when I became only one to pass the Physics subject in B.Sc first year among the hundreds of students from Trichandra campus by acquiring highest score in Physics throughout the country. So, my interest studying physics ought to be seeded during my I.Sc. class that became animated during my B.Sc. course.

2. What strategies did you use to be successful in college?

Education system in Nepal is quite different compared to the education system from abroad. Student’s overall quality or success is primarily determined by their percentage acquired in the annual exam. Students, who attend regular classes and intensively prepare their final exam during a couple of months, can secure a good percentage. This is the trend of most of the students in Nepal. However, I usually tried to understand the subjects in depth and think analytically and realize practically in our common sense. In addition, I used to balance my time between academics and my social life; I think that is the most important eminence required to be a successful student.

3. You have a long teaching experience. How was your experience in becoming formal student again during the PhD?

As I moved to US for my Ph.D. after 13 years of teaching experiences, I was wondering that how could I adopt as a fresh student in the university. When I joined to the university, I found many adult undergraduate and graduate students. In US, adult students also used to go to university after their job retirements or family settlements. So, I never felt any hesitation as becoming a PhD formal student and I easily adopted with the education system in US. I always used to keep me busy to prepare homework, exams and research works. In recognition of my outstanding academic performances, I was honoured by several prestigious awards and scholarships from the university.

4 What have you found to be the roughest aspect of being a physicist, if any?

I think, sometimes this can happen in the research project. When one puts an immense effort to a research project with a lot of investment of times and funding, but these all efforts will be useless if a proper result is not obtained. On the other hand, sometimes a genuine research result may not be accepted for the publication due to the biasness of the different group interest. I think this is the saddest part in this profession; however, occurrences of such cases may be very rare.

5. You are also a recipient of the prestigious Jack Eddy Postdoctoral Fellowship Award from the UCAR Visiting Scientists Program. Could you please share the experience?

Jack Eddy Postdoctoral Fellowship is a very prestigious award organized by University Corporation of Atmospheric Research (UCAR) visiting scientist program and sponsored by NASA Living With a Star Heliophysics program. The stringent selection criteria for this fellowship include outstanding research accomplishments, publications, the quality of research proposal and its impact on future research in space physics. I am proud to mention that I am one of only three recipients of this award in a global competition.

6. Do you have a favorite research paper (written by yourself or somebody else)? Could you please suggest the practical applications of your research outcomes?

There are my several favorite research papers that report on the dynamics of low-latitude ionospheric irregularities. I would like to mention one of my research papers that explains climatology of post-sunset equatorial spread F using radar observations. This paper was listed among the top five most popular papers in Space Physics published in Journal of Geophysical Research (JGR) by American Geophysical Union (ACU). The paper reports the seasonal and solar cycle variation on onset of ionospheric irregularities heights and times that is significantly important to determine the altitude of the satellite path in which GPS signal will be disrupted due to the fluctuations of radio signal that passes through the ionosphere. Improving our knowledge and understanding of the drivers of this day-to-day variability is a very active area of research in the Space Weather program and Aeronomy community due to its importance for both civilian and military communications and transportation. As space-based technologies become increasingly intertwined into our day-to-day lives and national security, it becomes paramount to understand how they can be disrupted. For example, when plasma in the ionosphere between a satellite and a receiver is turbulent, the transmitted signals scintillate similar to the twinkling of starlight as it traverses through the turbulent atmosphere. This scintillation poses a problem for a receiver, which can lose the ability to track that signal. Additionally, the structures in the ionosphere can degrade navigation solutions obtained from the Global Positioning System (GPS) beyond expected accuracies, adversely affecting technologies that rely on this system. Simulations indicate that the dynamic response can be forecasted a few days ahead, suggesting the possibility of ionospheric irregularity prediction given the right set of observations.

7. As the editor of NPS, could you please share your future plan?

So far NPS is not able to publish any standard journal of physics. My first plan is to publish NPS journal biannually and working toward peer review journal publication. To achieve this goal, we have to develop the dynamics website of NPS to publish the articles online. For this purpose, we need a financial support and expertise in the field of physics. We have a huge numbers of high skilled Nepalese Physicists around the globe, especially from USA. I believe that they are ready to contribute NPS whenever needed. So I am planning to make a proper environment and network to get a full cooperation from all physicists. I would like to propose a plan to collect financial support for NPS activities with a motto that “One-dollar per month for NPS”. A small contribution from single member will collectively make a great strength of the contribution to conduct NPS activities. I also request all Physicists around the globe to provide their feedback, suggestions and collaboration to make the NPS journal publications as a peer review.

8. What are the current challenges in Nepal for research activities? Are there short-term and long-term items, which could address the challenges?

There are several factors that affect research activities in Nepal. The current education system including elementary school to college is not suitable to prepare the students and faculties to involve in the research works. Our teaching methodology does not focus to develop the creativity skills of the students that is very crucial to generate the interest of the students in the research field. We don’t have adequate facilities and funding to carry out the research projects for the undergraduate and graduate students. The institutes responsible for research funding under the umbrella of Nepal Government, such as University Grant Commission (UGC), Nepal Academy of Science and Technology (NAST), and Tribhuvan University are suffering from politicization. The leaders of these institutes are generally appointed on the basis of their political thought rather than their academic performances. So, they are directly influenced from the political leaders and they cannot function aptly to strengthen the research activities. As a short-term plan, we have to encourage the students and faculties to make involvement in the research projects by creating a proper environment as well as providing the financial support. I believe that the universities should lead the research activities by making clear and transparent policy. Professors should be appointed and promoted on the basis of their research grants awarded, publication records, and serving as an adviser to the students for their research projects. The research institutes and universities should be autonomous and keep them out of political influences so that highly qualified and visionary leadership can get the opportunity to lead the institutes who can develop national and international collaboration for the research projects. In long term policy, structure and organization of the education system in Nepal should be changed in such a way that the students and faculties will be highly encouraged to involve in the research projects.
Perhaps, most problematic for research activities in developing nations like Nepal is the brain drain. Leaders, planners, and administrators have less interest in national development as their entire families are migrating. Nowadays, every elite and middle class family from Nepal dreams to send their children abroad for further education or training. We are heading towards a situation where there will be scarcity of intellectual minds within the country. When a society’s best and brightest people move away in pursuit of better opportunities, the country will suffer from the lack of skilled manpower for its development. Skilled and well-trained manpower is very important for the research activities and for the overall development of the country. This issue can be addressed only when there is political stability and some prospects for economic prosperity. We can initiate a project to reverse the flow by doing campaigns to lure Nepali professionals back to Nepal on short and long-term internships.

9. Sir, would you like to add anything else?

I would like to share that I am back to Nepal from United States after my PhD and Postdoctoral research experience with having a robust commitment to contribute to our nation in the field of Physics on teaching and research projects. Our huge number of high skilled manpower in Physics has been dispersed around the world, while many of them are also holding a prominence status. I would like to request to all Nepalese Physicist around the globe to contribute to our motherland in research works by their academic and financial supports. We can conduct collaborating research projects by making involvement of our manpower including students from Nepal and also by proper utilization of our resources. A small support from an individual member will collectively be a great contribution to our country that can change our society significantly.

Updates on Work, bibliography

Here are the latest in the line of my work at CCNY:

Bias Correction of high resolution MODIS Aerosol Optical Depth in urban areas using the Dragon AERONET Network N Malakar, M Oo, A Atia, B Gross, F Moshary AGU 2013 Oral Presentation in A31K (SWIRL_DA)

Injection Of Meteorological Factors Into Satellite Estimates Of Surface PM2.5 N Malakar, L Cordero, Y Wu, B Gross, M Ku 2013 EMEP Conference (www.nyserda.ny.gov/emep-2013), Albany, NY

Assessing satellite based PM2. 5 estimates against CMAQ model forecasts L Cordero, N Malakar, Y Wu, B Gross, F Moshary, M Ku SPIE Remote Sensing, 88900U-88900U-15, Germany

Ingesting MODIS land surface classification into AOD retrievals AA Atia, A Picon, N Malakar, B Gross, F Moshary SPIE Remote Sensing, 888707-888707-11, Germany

Assessment Of Pm2. 5 Retrievals Using A Combination Of Satellite AOD and WRF PBL heights in Comparison to WRF/CMAQ Bias Corrected Outputs L Cordero, N. Malakar, Y Wu, B Gross, F Moshary 2013 CMAS Conference, NC, USA

Regional estimates of ground level Aerosol using Satellite Remote Sensing and Machine-Learning Nabin Malakar, A. Atia, B. Gross, F. Moshary, S. Ahmed, and D. Lary AMS 2014, Atlanta, GA, USA

A Regional NN estimator of PM2.5 using satellite AOD and WRF meteorology measurements Lina Cordero, N. Malakar, D. Vidal, R. Latto, B. Gross, F. Moshary, and S. Ahmed AMS 2014, Atlanta, GA, USA

Use of NN based approaches to create high resolution climate meteorological forecasts Nabin Malakar,  B. Gross, J. E. Gonzalez, P. Yang, and F. Moshary AMS 2014, Atlanta, GA, USA

Assessing Surface PM2.5 Estimates Using Data Fusion of Active and Passive Remote Sensing Methods L Cordero, N Malakar,  Y Wu, B Gross, M Ku, British Journal of Environment and Climate Change 3 (4), 547-565, 2013 DOI : 10.9734/BJECC/2013/7668