Category Archives: News

Super-Terminal Raindrops Verified

Warp-Speed Raindrops

It’s a rain race out there. In the meteorological equivalent of breaking the light-speed barrier, new research shows that the smaller droplets in a rainstorm often surpass what appears to be the speed limit for rain.

“What surprised us was not so much seeing the superterminal drops,” says physicist and co-author Raymond Shaw of MTU, “but seeing the deeper, compelling patterns.” He explains that as rain falls harder, the fraction of superterminal, or speeding, small drops increases.

Read more at Science Magazine, by Phil Berardelli. This article was posted on June 12, 2009.

Geophysical Research Letters 2014
Geophysical Research Letters 2014

Further evidence for super-terminal raindrops
M. L. Larsen1, A. B. Kostinski and A.R. Jameson
DOI: 10.1002/2014GL061397

A network of optical disdrometers (including laser precipitation monitors and a 2-dimensional video disdrometer) was utilized to determine whether the recent reports of “super-terminal” raindrops were spurious results of drop breakup occurring on instrumentation. Results unequivocally show that super-terminal raindrops at small (less than 1 mm) sizes are ubiquitous, are measurable over an extended area, and appear in every rain event investigated.

Read more at Geophysical Research Letters, published by Wiley Online Library in 2014.

Confirmed: Some raindrops fall faster than they should

Five years ago, scientists reported that raindrops, especially small ones, often fall through the air much faster than they should. Some researchers have suggested that these “super-terminal” raindrops (ones traveling more than 30% faster than their terminal velocity, at which air resistance prevents further acceleration due to gravity) were fragments of larger drops that had splattered off the team’s instruments, with the smaller bits retaining the speed the larger drop had before it struck the instrument. But new research hints that the speedier-than-expected drops are the result of natural processes—and that, moreover, they make up a substantial fraction of rainfall.

Read more at Science Magazine, by Sid Perkins. This article was posted on August 26, 2014.

Physics Picnic Thursday

super-8-houghtonPhysics Department Picnic and Social
Where: Houghton City Park (same location as last yr)
Located by the Super 8 Motel
When: Thursday, August 28th, 2014, at 11:30 AM
Who: Everyone – Faculty, Staff, Graduate Students,
Undergraduate Students and Families etc.

Need a ride or directions: contact Diana or Taana, Room 118 Fisher, 7-2086

2014 Physics Picnic

Kamal Dhungana Research

Kamal Dhungana Research
Schematic diagram of a fluorinated boron nitride nanotube based spin filter device.

Fluorinated boron nitride nanotube as an ideal spin filter

Advisor: Dr. Ranjit Pati

Understanding the electronic structure and the transport property of nano scale materials is of fundamental importance, since these materials are the ultimate candidates for the future of nano technology. Several nano materials, such as quantum dots, semiconducting nano-wires, and organic molecules, have been explored both theoretically and experimentally as the components of electronic circuitry over the last two decades. Among several interesting nano materials, metal free magnetic nano materials are found to be very enticing due to the presence of magnetism in the absence of magnetic ions. Traditionally, the magnetism comes from partially occupied d and f states in the materials; however, this understanding is not always true since s and p states are found to contribute to the magnetism in the metal free magnetic materials. The main advantage of these materials is their high Curie temperature; as a result, they can be utilized in room temperature spin-electronics (spintronics). Recently, using a first-principles approach, we have demonstrated that the fluorinated boron nitride nanotube (BNNT), which is a metal-free magnetic entity, can be used as an excellent spin filter. All majority spin carriers are almost completely blocked while passing through the fluorinated BNNT channel, allowing only the minority spin carriers to pass. We have shown that the long range ferromagnetic spin ordering in fluorinated BNNTs occurs at a temperature much above room temperature.

For more information, please visit my webpage: http://www.phy.mtu.edu/~kbdhunga

By Kamal B. Dhungana

Reference:

Kamal B. Dhungana, Ranjit Pati, Fluorinated Boron Nitride Nanotube Quantum Dots: A Spin Filter. J. Am. Chem. Soc., 2014, 136, 11494–11498. 

Interview on “Superior” Supercomputer

Computational StructureAny university involved in compute-intensive research would love to have a supercomputer at its disposal. Michigan Technological University is one of the fortunate ones to have a super-fast machine accessible by the entire research community on campus. The computer is known as “Superior” and we sat down with Gowtham S., Director of Research Computing at the University, to hear more about it.

insideHPC: The system’s installation just had its one year anniversary. What are some of the current projects that are harnessing all of this power?

Gowtham S.: Modeling the circulation and particle transport in the Great Lakes system, multi scale modeling of advanced materials and structures, nanostructured materials for electronics, biosensing and human health implications, and unsupervised learning in Big Data and social networks are some of the on going projects that use the power of Superior. Here is the complete listing of all 30 projects.

These projects have produced nearly two dozen publications as well, and several proposals are underway for even more projects. That makes us quite happy.

Read the full interview at insideHPC.

This interview refers to three projects within the Department of Physics.

  • Physics, Johana Chirinos, Investigations in ultra-high-energy cosmic ray physics
  • Physics, Ranjit Pati, Computational study of charge and spin transport in nano-scale junctions from first-principles
  • Physics, Ravindra Pandey, Computational studies of nanostructured materials for electronics, biosensing and human health implications