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

Proposals in Progress for July 14, 2014

PI Claudio Mazzoleni (Physics) and Co-PIs Lynn Mazzoleni (Chem), Raymond Shaw (Physics) and Will Cantrell (Physics), “Azores Integrated Measurements (AIM): Free Tropospheric and Marine Boundary Layer Aerosol Properties at the Eastern North Atlantic Permanent ARM Facility and the Pico Mountain Observatory, Azores,” US Department of Energy.

PI Dongyan Zhang (Physics) and Co-PIs Nazmiye Yapici (Physics) and Jim Baker (IEE), “High Brightness Fluorescence Reagents for Biomedical Applications,” NSF.

PI John Diebel (IIE) and Co-PI Yoke Khin Yap (Physics), “High Brightness Fluorescence Biosensors and Chemosensors,” University of Michigan/MIIE.

Read more at Tech Today.

In Memoriam: Robert Mount

Robert Mount
Robert Mount

Professor Emeritus Robert H. “Bob” Mount, a longtime member of the physics faculty, passed away July 2 at his home in Hancock. He was 86 years old.

Mount came to Michigan Tech in 1954 from Cleveland Cliffs Iron Co., where he was employed as the chief geologist. He retired from the University in 2000. For much of his career, he taught introductory physics courses. “His 46 years of service is the second-longest in department history—the longest being James Fisher,” said physics professor Bryan Suits.

His colleagues remember Mount as health conscious. “His extensive early-morning exercise routine was very important to him,” Suits said. “He would retire early so he could get up at 3 or 4 a.m. to do his workout. Hence, he often passed when it came to attending the department’s evening events—they were past his bedtime.”

Professor Don Beck also remembered his physical fitness—and his motorcycle, which he rode to campus whenever weather permitted. “He was an amiable colleague,” said Beck, “and he had an extensive collection of college-level books that he managed to fit into one of our smallest offices.”

Mount donated most of that collection to the Society of Physics students upon his retirement. “Fourteen years later, those books are still in the undergrad physics room and are consulted and used on a regular basis, sometimes even by grad students and professors,” said Professor Raymond Shaw.

Professor Robert Nemiroff remembers Mount as a cheerful sort, before and after his retirement. “He always seemed in good spirits and had kind words or a humorous story for me, and I would expect for his students as well,” he said.

Mount was also an animal lover with a big heart, said Professor Jacek Borysow. “Bob took all the ugliest dogs from the animal shelter and took care of them,” he said. “I think there were times when he had something like six dogs, and they all had missing legs, ears or tails, and they were very old.”

Mount served in the army at the end of World War II and went on to earn a bachelor’s degree from Ohio State University and an MS in Geophysics from Michigan Tech.

Bob is survived by his children, Becky, Nancy, Rob and Jeff (Elyssa), and his grandchildren, Rachel and Gabe. He is also survived by his pets, Peppy, Kitsalee, Linky and Mama, his devoted and adoring lap cat.

Mount’s body will be cremated, and no public visitation or service will be held. O’Neill-Dennis Funeral Home is assisting the family with arrangements.

From Tech Today.

Please feel free to leave comments on your experiences with Bob Mount.