Akron Phy sics Club


Archive 2010   
 
 

                     
2010       
January  Peter Tandy - Quarks and Gluons: Known Unknowns and Unknown Knowns 
February Mahmoud Assaad - The Lunar Land Rover Tire 
March
James Carroll - Everything You Wanted To Know About Nuclear Isomers - but Were Afraid to ask 
April Charles Rosenblatt - Dancing Fluids In Artificailly Controlled Gravity 
May Rama Gorla - The Development of the Airplane from the Wright Brothers to the Present Time 
September Sheila G. Bailey - The Future of Space Photovoltaics 
October Daniel Fleisch - The Science of the Renaissance 
November Clare Rimnac - Engineering the Natural History of Total Joint Replacements 

 

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Akron Physics Club

Newsletter

Meeting Announcement: MONDAY, January 25, 2010 - TANGIER, 6:00 PM



Speaker for our first meeting of the year is: Dr. Peter C. Tandy, Professor of Physics, Kent State University, who has previously served in such capacities as Director of the University’s Center for Nuclear Research and as Vice-President for Research. Dr. Tandy is an authority on nuclear physics. The title of his January presentation is:

QUARKS AND GLUONS

KNOWN UNKNOWNS AND UNKNOWN KNOWNS

Providing a touch of some of the new perspectives he hopes to leave with us, Dr. Tandy reminds us that inside atomic nuclei are protons and neutrons — and inside them are only quarks and gluons. Their properties and the way they interact are very strange; but what does this have to do with everyday life? It is known that about 98% of the mass of any everyday object (such as our bodies), comes not from the mass of these quarks and gluons but from their motion and their mutual interaction. This “unknown known” is well understood by specialists in the underlying field theory, but it’s not more widely known.

Another unknown known is the fact that the interaction of quarks and gluons gets progressively weaker as they get closer together; however, there are well-known aspects of the quark-gluon description of matter (e.g., one cannot dislodge a quark or a gluon) that no one knows how to prove from the underlying theory.

So how can one work with a theory that has never been solved exactly?

 

Minutes, January 25, 2010

  After a dinner of chicken breast with mushroom sauce, Chairman Ernst von Meerwall inquired about visitors to the meeting – and Tom Brooker introduced his and Marie’s guest, Philip Thomas of the University of Akron’s Music Department, an accomplished pianist who has given concerts all over the world. And Ernst was then pleased to welcome back, to a round of applause, our Webmaster, John (a.k.a Jonah) Kirszenberg, who missed the last meeting while being relieved of a tumor that was excised at Akron General. John looked great.

  The introductions were followed by a treasurer’s report by our talented Treasurer, Dan Galehouse, who reminded us that we began the evening with $348.60. Then, with neither an electronic nor a mechanical calculator, he lucidly explained how, after collecting from the regulars and paying Tangier, including accounting for guests, we finished the evening with cash assets of $334.60 ­– barely enough to attract thieves to the Tangier parking decks.

  Dan’s gratifying report was followed by Program Chairman Sam Fielding-Russell, who reviewed the list of speakers we can look forward to for the rest of the 2009-2110 season that he has arranged for us:

03 22 10 Prof. Jeff Carroll of Youngstown State Physics Department
04 26 10 Prof. Chuck Rosenblatt (CWRU) Magnetic Levitation of Fluids
05 24 10 Rama Gorla (KSU) Development of Aircraft – From the Wright Bros to the Present.

  Ernst then called on Bob Erdman, the Akron Physics Club’s representative on ACESS, the Akron Council of Engineering and Scientific Societies. Bob will be judging a Science Fair in that regard this weekend. And he indicated that he will be contributing ACESS news for this APC Newsletter in the future.

  Which brought us to the reason for our gathering. Ernst introduced our speaker, Dr. Peter Tandy, Professor of Physics, Kent State University – whose areas of research include theoretical hadron physics, strong interaction physics, and nuclear/particle physics. His presentation was entitled “Quarks and Gluons: Known Unknowns and Unknown Knowns,” a combination of words, he pointed out, first articulated by the infamous Donald Rumsfeld.

  Dr. Tandy began by defining the scale of the very small particles that are his field: The size of a molecule is in the range of 10–9 meters; its atoms are an order of magnitude lower, 10–10 m; their nucleus is 10–14 m; inside the nucleus, nucleons (protons and neutrons) are 10–15 m; and flying around inside them, quarks are 10–18 m (the same size as surrounding electrons).

  In the abstract he provided about his talk, Dr. Tandy reminded us that “inside atomic nuclei are protons and neutrons – and inside them are only quarks and gluons. Their properties and the way they interact are very strange; but what does this have to do, he asked, with everyday life? Answer: It is known that about 98% of the mass of any everyday object (such as our bodies), comes not from the mass of these quarks and gluons [like photons, gluons are without mass] but from their motion and their mutual interaction This unknown known is well understood by specialists in the underlying field theory, but it’s not more widely known. The mass generation,” he said, “is due to broken symmetry.”

  Another unknown known, he pointed out, is the fact that the interaction of quarks and gluons gets progressively weaker as they get closer together. Proving this mathematically earned its discoverers the Nobel Prize in 2004; however, there are well-known aspects of the quark-gluon description of matter (e.g., one cannot dislodge a quark or a gluon) that no one knows how to prove from the underlying theory. So how can one work with a theory that has never been solved exactly? For the remainder of his talk, Dr. Tandy proceeded to answer this question. Since 98% of the mass of one’s body (or anything else) is an unknown known, the origin of the mass in the remaining 2% becomes a known unknown.

  Our speaker’s slides included an aerial view of the U.S.’s Jefferson Laboratory, a relatively small early tool that was used to study these and other questions. And we then saw some great interiors of its successor, CERN’s new Large Hadron Collider on the French-Swiss border near Geneva – including an animation of the path of the particles as they are first accelerated in a relatively small circle, which is tangent to a larger surrounding circle to be further sped up, before being released in opposite directions into the 17-kilometer circumference of the gigantic outer circular tube at very high energies (i.e., 100,000 Newtons) reaching velocities close to the speed of light before colliding and delivering a blizzard of data.

  Results of tests at accelerator facilities to date have resulted in the conception of a “new subatomic periodic table” made up of elementary particles and their interactions. It includes mesons, gluons, photons, leptons, the six “colors” of quarks, as well as their antiparticles, “and all that,” our speaker explained as he presented a graphic in which the elementary particles are represented by of 16 stacked cubes, with six quarks occupying two thirds of the top two lines, whose fourth places are filled by “force carriers,” a photon and a gluon. The bottom two lines are six leptons, terminated by bosons, Z and W.

  Unhappily, your secretary’s Olympus (Radio Shack) recorder failed to record Dr. Tandy’s speech [I now know why!] and when he sent his slides via e-mail, we ran into a variety of problems: First, AOL found 29.8 MB too big a package to accept. And when our speaker went to the trouble of splitting his package in two, only some of the thumbnail icons are willing to open (probably because my aging Mac doesn’t have Keynote); however, Webmaster John Kirszenberg translated enough of them for me to compose this piece. So, in conclusion, I am reduced to reproducing some provocative aphorisms of elementary particle physics:

  Nucleons are bound states of three quarks. Quarks and leptons are currently regarded as elementary (e.g., structureless). Mesons are structurally the simplest hadrons. Hadrons are bound states of two (mesons) or three (baryons) quarks/gluons. Interactions between particles are mediated through gauge fields (gluons, photons, gauge bosons). The current state of comprehension of particle interactions mainly involves Quantum Chromodynamics, the theory of how quarks and gluons interact with themselves and each other. But QCD, the pillar of the standard model, is only the starting point for addressing the problems yet unsolved: one of our speaker’s slides quotes the NSAC Long-Range Plan as stating, “Connecting he observed properties of nucleons with the underlying QCD is one of the central problems of modern science.”

  There, obviously, is more to elementary particle physics than the standard model.

  With apologies for this abbreviated edition,

Jack Gieck

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Akron Physics Club

Newsletter

Meeting Announcement: MONDAY, February 22, 2010 - TANGIER, 6:00 PM



Speaker for our February meeting is: Dr. Mahmoud Assaad of Goodyear’s, who will be telling us about his company’s development of

THE LUNAR LAND ROVER TIRE

. . . or, as he calls it in a lighter vein, “Man and Moon – From Romancing with Lyrics to Exploring with Rovers and Crashing with Probes.” His presentation reviews the use of numerical modeling in the development of a non-pneumatic tire for Lunar Rover Vehicles, and the ability to predict the soil-tire interaction of the geometric shape of the tire, its tread, the resultant spring rate, and even its load-deflection curve.

 

Minutes, February 22, 2010

  After an excellent dinner of what Founder, Lucky Charlie (III), characterized as "a very nice, tasty slab of roast beef in a little sauce/gravy, with roasted potatoes," Chairman Ernst von Meerwall asked who had brought whom for the first time – to which Bob Erdman responded that he had brought student Tracy Parsons; and Crit Ohlemacher (welcomed back!) introduced his student daughter Lydia.

  Ernst then called on Treasurer Dan Galehouse for an estimate of our wealth – to which our Mr. Moneybags (a.k.a. Mr. Moneybox) responded with the intimate details (“done by arithmetic”) of how we achieved a gain in our net funds from $334.60 to $340.00 for the evening.

  Then, switching to his Jekyllian side, Dr. Dan reminded us of our program about the infamous claim of “Cold Fusion” several years ago. Well, as it turns out, Dan had found a paper (by Luis Alvarez) published in Physical Review in 1957, claiming that bits of lithium/ deuterium combinations actually do fuse when impacted by cosmic rays – albeit at a rate of occurrence that could never be a practical source of power. And a second Galehouse discovery (on Google) was a review by philosopher David Harriman of a rare book, Quantum Mechanics and the Theory of Elementary Waves, by Lewis Little, which claims that this work constitutes a local theory that contradicts quantum mechanical experiments. Dan will make his sources available to anyone (18 and over?) who asks.

  Which brought us to the time for Program Chairman Sam Fielding-Russell to review our remaining programs he had managed to assemble for our spring calendar. They are:

04 26 10 Prof. Chuck Rosenblatt (CWRU) Magnetic Levitation of Fluids
05 24 10 Rama Gorla (KSU) 'Development of Aircraft – From the Wright Bros to the Present.

  At which point Ernst invited Bob Erdmann to report anything new on his role as our club’s respresentative in ACESS. Bob indicated that he had attended a board meeting, and he exuded praise for the science fair he had been invited to. Following which Ernst reminded us that by next month, Founder Charlie will be asking for nominations for officers for the following year. Know ye that present positions are not permanent! [Especially this one!)

  Which brought us to the introduction of our speaker, Dr. Mahmoud Assaad of Goodyear’s Innovation Center, who grew up in Lebanon, where he received his undergraduate degree before coming to Iowa State University [excellent engineering school even in the1940s, when it was still Iowa State College of Agriculture and Mechanic Arts!]. It was at Iowa State that Dr. Assaad earned his PhD in engineering science and mechanics as well as a minor in mathematics, before coming to Goodyear in 1983, where he earned 45 patents while developing the product that was the subject of his presentation: “The Lunar Land Rover Tire,” – or (as he sagaciously displayed on the screen), “Man and Moon – From Romancing with Lyrics to Exploring with Rovers, and Crashing with Probes.” As he pointed out romancing the moon goes back to ancient cultures, where it sometimes figured in the local religion.

  It was in the 1970s, only a couple of years after astronauts actually landed on the Moon that a vehicle to operate on the Moon’s surface was planned. When NASA began preparing a list of 52 primary requirements, the development of its tires was No. 2 on the priority list.

  It sounds very natural for NASA to have selected Goodyear, America’s largest rubber company, to develop a tire for its Lunar Rover – a tire capable of traveling over the unpredictable surface of the Moon. But a tire for such a purpose could not be made of rubber, which is shatteringly brittle at temperatures barely three degrees Kelvin. In fact nearly all elastomeric options would probably be destroyed by the naked, unfiltered ultraviolet. So the solution to achieving a flexible tire having a spring rate, frictional characteristics and other properties capable of driving the vehicle’s wheels while cushioning its instruments and its driver would be to make the product out of wire mesh— a woven-wire torus having a structure resembling a large-diameter arterial stent knitted into the shape of a doughnut. The first generation would use steel piano wire.

  The tire would be designed to fit 32-34 inch wheels and it would have to operate over a wide range of loads from 57 to 550 pounds at speeds of 10-12 mph. At the low end of the loading scale, it would be necessary to penetrate the soil sufficiently to develop traction with (solar) powered wheels; moreover, one of rover designs involved lifting each wheel (and its axle) with a crane-like geometry that permitted the vehicle to “walk.“ This was the challenge accepted by our speaker.

  For an engineer who developed mechanical rubber products beginning on the drawing board (having first done some modest calculations), then making a single-cavity mold and heading to the physical testing laboratory with experimental samples in several compounds, the accomplishments that our speaker achieved entirely with mathematical models seems mind-numbing. These included developing shapes from equations involving circles, ellipses, octagons(!), bent diamonds, and other shapes we saw on the screen.

  After developing his theoretical mathematical models, Dr. Assaad was then able to predict how they would react to forces not only in the vertical mode (their load-deflection characteristics), but also laterally, longitudinally, torsionally, and evenpredicting their soil interaction as the open wire structure penetrated the soil, which was found to cover the range of coarse to talc, the last having the consistency of flour. (Soil samples had been measured by astronauts who carried instruments and returned samples – which would permit Case Western Reserve University to analyze their size, shape, and relative quantities, and to prepare “Moon soil.”

  Our speaker’s audience believed him when he declared that his calculations were “computationally intensive.“ Some detail about the resulting initial product (from a NASA/Goodyear website) follows:

  “Four major components comprised the LRV tire's design: mesh, tread, inner-frame and hub. The mesh was woven out of piano wire to provide a soft, springy surface to contour to the ground and provide good ride quality. The tread was made from a series of metal strips intended to protect the mesh from impact while providing increased contact area for floatation in soft soil. The inner-frame, comprised of a relatively rigid metal structure, prevented the mesh from over-deforming during impact, while the hub held the mesh and frame together as well as connected the wheel assembly to the rover.

  “Before the wire mesh could be woven, 3,000 feet of wire had to be custom-crimped and cut into 800 pieces. A handloom was designed to weave the crimped wires into a rectangle measuring approximately 100 inches long and 25 inches wide. Sides of the mesh cylinder were pulled down and clamped to a circular jig, roughly the size of a wheel hub, to give the mesh the shape of a tire. Then the jig and mesh were heat-treated to relieve residual stress from the wire. The end result was a tire that looked like the skeleton of an Earth tire. The approach worked because each tire was only required to support about 60 pounds of weight (on the Moon, the equivalent of 360 pounds on Earth) and be used initially for a maximum of 75 miles.”

  Our speaker treated us to a PowerPoint slide show picturing a variety of tire designs that have been built, including Russian (which had spikes) and Chinese offerings. All were similar in concept, and most proved to have similar performance and durability. One included a “bump stop” to protect the vehicle if the outer structure of the tire failed; another had plates linked in a pantograph geometry. We even saw the tire used on the Mars vehicle. And we also saw how the vehicle and its tires were fitted into the landing module.

  When the Lunar Rover vehicle was first conceived, a list of 52 primary requirements was prepared, the development of successful tires was No. 2 in the priority list. From what we heard (and have seen on television on both the Moon and Mars) that objective has been accomplished.

Jack Gieck

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Akron Physics Club

Newsletter

Meeting Announcement: MONDAY, March 22, 2010 - TANGIER, 6:00 PM



Speaker for our March meeting is: Dr. James J. (Jeff) Carroll Professor of Physics and Astronomy at Youngstown State University, about whom the university says, “Dr. Carroll is one of the world’s leading researchers into the application of low-energy photonuclear reactions to the production clean nuclear energy from isomers, isotopes that are in effect ‘nuclear batteries.’ With over a decade of experience and more than forty refereed publications, he has given invited presentations to the National Academy of Sciences, the Defense community, and the Undersecretary for Science of the Department of Energy, as well as numerous conference talks.” The title of his talk is:

EVERYTHING YOU WANTED TO KNOW ABOUT

NUCLEAR ISOMERS – BUT WERE AFRAID TO ASK

About which our speaker further explains, “Isomers are familiar to some, unknown to many, yet have proved to be valuable in understanding nuclear physics and in the future may be used for (many) applications.” His talk will describe why isomers exist, why they are important and how the YSU Isomer Physics Project is adding to the body of nuclear data related to isomers.


Minutes, March 22, 2010

  Chairman Ernst being in Oregon for an APS meeting, the APC meeting was opened by long-time vice-chair Darrell Reneker, who said he was delighted to do so because “it gives him something to do!” Darrell then displayed a yellow sheet of paper, which, he claimed were his notes on what Ernst had offered in the way of order and guidance for a meeting – including the occasional line, “Smart Alec Comments,” an instruction and entreaty that Darrell filled to perfection!

  When he called for “first time attendees, Bill Dunn introduced his wife Carroll – but we should add that Brent Sisler of ACESS also graced us with his attendance. And when he asked Treasurer Dan Galehouse for a report on our wealth, Dr. Dan, lightning calculator that he is, emitted his shortest summary on record, disclosing that we had gained $8.00 for the evening [cheers heard], resulting in a new balance of $348.60. But in his alternate role as scholarly researcher (featuring esoteric Google entries) Dan announced that he had obtained, through an interlibrary loan from an Indiana archive, a copy of the book he had mentioned last time. Our Newest Middle, he reported, was “obviously written by a crackpot, which is why there are no other copies.” But typically, it has attracted comments by philosophers, which can also be found on Google.

  The next item in our notoriously short business meetings was Sam Fielding Russell’s report as Program Chairman – a job from which he is retiring after years of outstanding programs (thank you, Sam!). He reminded us that we have only two meetings left, the first of which is previewed above. And the last one until fall, on May 24,th will be Prof. Rama Gorla of Kent State University, who will be speaking on “The Development of the Aircraft – From the Wright Bros to the Present Time.”

  At which time our Nominating Committee Chair (and Founder) Charlie Wilson announced the really good news that Charles Lavan, speaker for two of our really great presentations, has agreed to accept Sam’s portfolio as Program Chairman. At the next meeting, Charlie advised, he recognizes that he is obligated to come up with a full list of nominations – for which he will appreciate volunteers, especially for the role of Assistant Secretary. ­

  Our ACESS rep Bob Erdman thanked Brent Sisler for visiting and reported that he had gone to the last joint ACESS/American Chemical Society meeting, where the speaker was from the Akron History Museum; and the subject was the study of (and sometimes the rebuilding of) bones in archaeological digs in northern Ohio. Bob had also attended a couple of science fairs.

  Which brought the meeting to the reason we came. It was the time for introduction of our speaker, Dr. James J. (Jeff) Carroll, Professor of Physics and Astronomy at Youngstown State University, about whom his university says, “Dr. Carroll is one of the world’s leading researchers into the application of low-energy photonuclear reactions to the production of clean nuclear energy from isomers.” The title of is talk was thus, not surprisingly, “Nuclear Isomers – or How I Learned How to Stop Worrying and Love Nuclear Physics,” (with apologies to Stanley Kubrick), a.k.a. “Everything You Wanted to Know About Nuclear Isomers ­ but Were Afraid to ask.

  Dr. Carroll began by defining his terms, beginning with “clean” – by which he meant releasing nuclear energy without leaving quantities of radioactive byproducts in the wake of reactions. We’re not talking about chemical reactions in above titles, nor chemical isomers (compounds having the same molecular formula, but with their atoms arranged in a different configuration). We’re speaking about different energies in the pattern of the neutron and protons making up the atomic nucleus.

  The conventional approach to generating nuclear energy has been to release some of the binding energy that holds a nucleus together. Dr. Carroll displayed a curve of the elements beginning with hydrogen on the left, ascending in order of increasing atomic weight (and decreasing binding energy) as the nuclei become more stable. These lighter elements are capable of fusion, ­the kind that occurs in the interior of stars. The curve peaks at nickel/iron (where the atomic nuclei are most stable, and thus have the least amount of energy available). As the curve descends, the atomic nuclei getting bigger as they move toward Uranium and beyond, the elements become increasingly capable of fission. However, the energy state (and half-life) varies significantly between isotopes of the same element.

  Nuclei change from one state to another by exchanging energy and angular momentum with the environment, typically in the form of electromagnetic radiation (a gamma ray). However, the decay of some nuclear states is inhibited since they have such different angular momentum compared with states at lower energy. For example, if the element merely glows, photons are inefficient in carrying large amounts of angular momentum.

  On the screen, our speaker illustrated angular momentum with the analogy of a rotating bicycle wheel, where the mass of and speed of the tire (an aphorism for the rotating shells of neutrons and protons) determine the angular moment and the strength of the gyroscopic effects. Isomers can have substantially different half-lives. At present, thirty-two nuclear isomers are known that have half-lives greater than a day, with the most extreme cases existing in isotopes with mass numbers near 180. For example, the isomer tantalum 180 lives at least 10 to the 16th years, while the isomer hafnium 178 has a half-life of only 31 years, but stores more than 1.2 X 10 to the 9th Joules/gram. For comparison, the (chemical) energy content of gasoline is on the order of 4 X 10 to the 4th Joules/gram.

  Utilizing an oval of electromagnets Dr. Carroll’s YSU Isomer Project has the objective of determining if there are isomers containing a large amount of energy to which, by adding additional energy, can boost the angular momentum of the particles in the nucleus – pushing the isomer into a more excited state, thereby causing it to decay to a lower level, and releasing a significant amount of energy in the process. Ideally, with the continuous input of energy, a collection of such isomers would continuously degrade one level at a time, changing from one isomer to another as the “fuel” depletes to its ground state – hopefully at a controlled rate. In addition to the extensive work done in YSU’s X-Ray Effects Lab, our speaker’s team has carried out experiments in cooperation with the Atomic Energy Commission.

  So far, the project has identified five new isomers, the longest one having a half-life of 20 minutes. Other half-lives vary from a few seconds to 10 minutes. The ultimate goal is to develop what has been called a “nuclear battery” i.e., a source that can be shut off when it is not needed, but having a reasonable “shelf life,” after which it could be restarted.

  Being in the field he is, Jeff couldn’t resist putting an image of George W. Bush (and Jimmy Carter) on the screen, their visages intimately associated with the caption, “NUCULAR.” He added that, to be honest, he should have added Bill Clinton, who was guilty of uttering the oral outrage at least once. [Actually, it can get worse. One of my fifth-grade teachers in St. Louis, displaying a picture on a wall chart, taught us that the dot in the center of a cell is its “NUCULOUS.” None of the above three (being younger than I am) were in that class, but it’s obviously a virus that’s been with us for a long time.]

Jack Gieck

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Akron Physics Club

Newsletter

Meeting Announcement: MONDAY, April 26, 2010 - TANGIER, 6:00 PM



Speaker for our April meeting is: Dr. Charles Rosenblatt Professor of Physics and Astronomy and Micromolecular Science at Case Western Reserve University. The title of his talk is:

DANCING FLUIDS IN ARTIFICIALLY CONTROLLED GRAVITY

About which our speaker says, “Most people are first drawn to liquid crystals by their beautiful optical textures: stars, curves, splotches, and zig-zags, all in a palette of colors rivaling the most ostentatious paintings of modern art.” But Dr. Rosenblatt’s interests are considerably more sophisticated, involving the microgravity of fluids:

“Using a ‘Faraday’ magnet, which is capable of generating a uniform magnetic force over a region of several cubic centimeters, we are able to apply an upward force on a fluid that exactly cancels out the downward gravitational force. In this talk I will examine the use of magnetic levitation for studies of fluids, with particular emphasis on “liquid bridges” and the Rayleigh-Taylor instability. Liquid bridges are regions of liquid that span the gap between two or more solid supports, and have applications in fields ranging from materials purification to biological respiration.”


Minutes, April 26, 2010

  Chairman Ernst von Meerwall called the meeting to order as we were finishing our meals. It was noted that there were 22 present for this meeting. He recognized particularly the 4 Univ. of Akron Polymer Science graduate students of Prof. Darrell Reneker who were present tonight to hear our invited speaker, Prof. Charles Rosenblatt.

  Treasurer Dan Galehouse gave his report of our club finances. I didn't catch the precise figures, but I'm guessing that the current balance is not greatly different from what Dan reported at our March meeting (some $400+) – far too little to interest any bank to hold it for us as a deposit. Thank you, Dan.

  Chairman Ernst asked for a report on the health of our long-time Club Secretary, Jack Gieck, who was unable to be with us this time. Charlie Wilson said that he had met with Jack that day. Jack had recently been hospitalized for what appeared to be a stroke. Jack was in good spirits, but was not up to attending and doing the minutes this time. Fortunately, Jack lent his neat little recorder to Charlie, so the meeting could be recorded. Charlie fervently hoped that someone would step up and do the minutes this time. (No such luck.)

  Chairman Ernst then noted that while it had been hoped that the annual election of Akron Physics Club officers could be conducted this evening, our meeting was already running quite late, and our invited speaker, Prof. Charles Rosenblatt, had an urgent need to leave the meeting by 8:30 pm. Therefore, Chairman Ernst suggested that the election could reasonably be postponed until the May meeting. This seemed a sensible thing to do.

  Therefore, it is intended that the following nominations will be made appropriately at the May, 2010, meeting, and that the elections also will be conducted then:

2010 -11 Officer Nominations for Akron Physics Club

Chairman: Ernst von Meerwall

Vice Chairman: Darrell Reneker

Program Chairman: Charles Lavan

To assist Charles Lavan, to the extent he wishes to be assisted as Program Chair: Informal Program Consultants (Five or more):
Sam Fielding-Russell, Leon Marker, Bob Hirst,
Wiley Youngs, Claire Tessier

Secretary: Jack Gieck

Back-up Secretaries (3 or more VOLUNTEERS needed):
Jerry Potts, ______?______?_______? !

Treasurer: Dan Galehouse
Back-up Treasurer: Bob Erdman

Nametag Marshals: Bob Erdman & Dave Sours

Webmaster: Jonah Kirszenberg

Liaisons with ACESS: Bob Erdman & Dan Galehouse

Reservations Secretary: Charlie Wilson

This summarizes the very limited number of nominations that have been received.
All persons listed here have advised us that they are willing to serve.

===========================================================================================

  It is still quite necessary for us to find some Back-up Secretaries for our long-serving and most excellent Secretary Jack Gieck, whose health is currently somewhat frail --- but who continues to actually enjoy doing the Minutes he does so well. Volunteers would be very much appreciated --- to help Jack occasionally, as needed, for the good of the Club.

===========================================================================================

  Then Chairman Ernst introduced our invited speaker, Dr. Charles Rosenblatt, Professor of Physics and Macromolecular Science at Case Western Reserve University. He completed his undergraduate degree in 1974 at MIT and his Ph.D. at Harvard in 1978. He has been on the CWRU Physics faculty for the past 23 years. He has many professional interests, particularly liquid crystals and also the microgravity of fluids. It was the latter he discussed this evening.

  The title of Dr. Rosenblatt’s presentation was Dancing fluids in Artificially Controlled Gravity; and he made a convincing case that it is most interesting to study the microgravity of fluids.

  Using a mid-size iron-core laboratory electromagnet, with pole faces that are decidedly non-parallel and, in fact, deliberately rounded and shaped so as to generate a uniform upward magnetic force (rather than a uniform magnetic field) above a region of several cubic centimeters, it is possible to apply an upward force on a small sample of a paramagnetic fluid (a chemical compound of a magnetic metal) that exactly cancels out the downward gravitational force.

  Water droplets, for example, in this special region of a magnetic field may be easily provided with a sufficient concentration of a paramagnetic salt, e.g. manganese chloride, to make the net force on them zero, or perhaps slightly upward or downward – and thus readily controllable by the experimenter, who simply adjusts the strength of the magnetic field appropriately. For all practical purposes, the fluid becomes weightless – and the surface tension of the droplets may then assume greatly enhanced importance.

  Dr. Rosenblatts’s talk reported the use of magnetic levitation for studies of several fluids, with particular emphasis on “liquid bridges” and the “Rayleigh-Taylor instability.” Liquid bridges are regions of liquid that span the gap between two or more solid supports, and have applications in fields ranging from materials from purification to biological respiration. Important examples include the fluid in the lungs, oil in porous rock, and water that wets a fabric.

  By studying the fluids in an effectively zero-gravity environment, information can be obtained about fluid stability, surface tension and dynamics, as demonstrated by one of our speaker’s experiments: It involved a pair of small co-linear aluminum rods with a water droplet suspended between their ends (in a region of "zero gravity"). A short movie showed what happened to this liquid bridge as the separation of the rods was slowly increased until the droplet stretched out, narrowing in diameter, and eventually broke into two smaller droplets, one adhering to each rod.

  Another type of experiment demonstrating the “Rayleigh-Taylor instability,” involved the instability that occurs when one places a dense fluid, e.g. water, atop an immiscible fluid of lesser density, e.g., an oil. Normally this is unstable, and the heavier fluid will eventually sink to the bottom. But one can stabilize this configuration by use of magnetic levitation of the heavier (paramagnetic) fluid. On turning off the magnetic field, instability reoccurs, and the heavier fluid falls through the lighter fluid in a complex but interesting way, that has been recorded by moving pictures. The “Rayleigh-Taylor instability occurs in many places in nature, including exploding supernovae, inertial confinement in nuclear fusion processes for energy production, and – closer to home – in vinegar-and-oil salad dressing! After a brief discussion period, limited by Professor Rosenblatt’s time constraints, the meeting adjourned at 8:30 pm.

Charlie Wilson & Associates

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Akron Physics Club

Newsletter

Meeting Announcement: May 24, 2010 - TANGIER, 6:00 PM



Speaker for May, our last meeting before our summer recess is Prof. Rama Gorla of Kent State University, who will be speaking on

THE DEVELOPMENT OF THE AIRPLANE
FROM
THE WRIGHT BROTHERS TO THE PRESENT TIME

A Professor of Mechanical Engineering at Cleveland State University, Dr. Gorla is also the Editor-in-Chief of the International Journal of Fluid Mechanics Research and Associate Editor of five Journals: International Journal of Turbo and Jet Engines, Applied Mechanics and Engineering Journal, Journal of MHD and Plasma Research, Journal of Mechanics of Continua and Mathematical Sciences and the Journal of Pure and Applied Physics. Dr. Gorla has published over 350 technical papers in refereed journals and contributed several book chapters in Encyclopedia of Fluid Mechanics – in which field he is a nationally recognized authority.

Somehow, despite these massive literary contributions, he has found the time to accumulate two awards for teaching excellence. Dr. Gorla’s current research is sponsored by NASA and by the Air Force Office of Scientific Research.


Minutes, May 24, 2010

  Appropriately, the last meeting of the 2009-2010 Season attracted our largest audience on record (37), saluting the 20th anniversary of the second generation of Akron Physics Club. The swelled attendance included several members of the Cleveland Astronomical Society – visitors with whom our Webmaster, John Kirszenberg (an ardent astronomer himself) shares our website in return for theirs: http://clevelandastronomicalsociety.org  

  Chairman Ernst von Meerwall invited them to identify themselves, and they turned out to be Bob and Ingrid Sledz, Jeanne Bishop, and Tom Benson. They extended an invitation for any of us to come to any of their meetings (calling for a reservation first if we want to participate in the buffet); and Ernst returned the invitation.

  Our Chairman then called on our faithful Treasurer, Dan Galehouse, for an assessment of our wealth. Dan reported that the swelled attendance for the evening had resulted in an uncomfortable gain of $19.00, bringing our new balance to $371.60. Then, however, when he actually counted the amount of cash on hand, the Akron Physics Club experienced its first incidence of metaphysics, the polyethylene-polypropylene moneybox had somehow gained $5.00!

  This event brought it to be time for our annual election, presided over by the club’s founder and former Chairman, Charlie Wilson. To repeat his collection of nominees announced at the last meeting (who, not surprisingly, were all elected), it was noted that Sam Fielding-Russell, who brought us three years of excellent programs, would be replaced by our new Program Chair, Charles (Chuck) Lavan – who gave us two outstanding programs of his own before becoming an officer of the club. The new list:

2010 -11 Officers for Akron Physics Club

 Chairman  Ernst von Meerwall
 Vice Chairman                         Darrell Reneker
 Program Chairman  Charles Lavan 
 To be assisted by Consultants Sam Fielding-Russell, Leon  Marker, Bob Hirst, Wiley Youngs, and Claire Tessier
 Secretary  Jack Gieck
 Assistant Secretary  Bob Erdman and Charlie Wilson
 Treasurer  Dan Galehouse
 Assistant Treasurer  Bob Erdman
 Nametag Marshals  Bob Erdman & Dave Sours
 Webmaster  John (aka Jonah) Kirszenberg
 Liaison with ACESS  Bob Erdman & Dan Galehouse

  Chairman Ernst announced that there will be a meeting of the officers during the summer (which has since been scheduled for July 19 at 11:30 AM at the University Club).

  At this point our Chairman introduced our speaker, Prof. Rama Gorla. Distinguished Research Professor of Mechanical Engineering at Cleveland State University, Dr. Gorla is also the Editor-in-Chief of the International Journal of Fluid Mechanics Research and Associate Editor of five Journals: International Journal of Turbo and Jet Engines, Applied Mechanics and Engineering Journal, Journal of MHD and Plasma Research, Journal of Mechanics of Continua and Mathematical Sciences and the Journal of Pure and Applied Physics. Dr. Gorla has published over 350 technical papers in refereed journals and contributed several book chapters in the Encyclopedia of Fluid Mechanics – in which field he is an internationally recognized authority.

  Somehow, despite these massive literary contributions, Dr. Gorla has found the time to accumulate two awards for teaching excellence. His current research is sponsored by NASA, and by the Air Force Office of Scientific Research. His topic for the evening was The Development of the Airplane from the Wright Brothers to the Present Time (AKA, Aerodynamics of the Airplane, from Subsonics to Hypersonics).

  Early aviation pioneers, our speaker said, realized they had several problems to solve if they were to achieve powered flight: A lightweight, high lift, low drag structure, a lightweight, powerful motor, and an efficient propeller. In the early 1890s, German aeronautical engineer Otto Lilienthal, had made major advances in gliders, on which he made a number of flights, but he was killed in an accident in 1896. Hiram Maxim actually built a powered flying machine in 1894, of which our speaker showed us an image (one of 194 visuals in his presentation!). The machine weighed 6000 lb, and was powered by two steam engines driving 18-foot propellers – which had flat surfaces and square-cut ends. (It never flew.)

  Our speaker then switched his attention to the Wright Brothers, accompanying his lecture with scores of images from a collection he had received as a gift from a group to whom he had spoken [more about public sources for these later]. He showed us their bicycle shop, their early experiments with kites, and the building of their first glider (which had a 32-foot wingspan) in 1902, which cost them about $15.00 – exclusive of their own intensive labor. After testing it in their homemade wind tunnel (which generated a 30 mph breeze) the brothers took their glider to Kitty Hawk in 1903, where if flew for a few seconds.

  Dr. Gorla showed us some the Wrights’ crude facilities at Kitty Hawk that they used for their glider experiments, as well as an early equation they used for lift, relating it to wing area, velocity, and drag, the significance of lift-to-drag ratio, as well as something called the Smeaton coefficient, which helped them eventually achieve flight – as did improvements in their wind tunnel (of which we saw photos).

  When they began working on powered flight, the key factors became weight, thrust, lift, and drag. Their first engine was a 4-cylinder design that weighed about 100 lb and generated 8 horsepower. Its propeller was an innovation, Dr. Gorla said. Other experimenters at the time (e.g., Maxim and Langley) had been using flat surfaced, square-end models, which had an efficiency of about 25%. The Wright Brothers fourth propeller design was contoured, and had an efficiency of 66%. We have all seen photos of the pair of these turning in opposite directions. The brothers had also worked on the shape of the wing tips by the time they made their four famous flights (the longest one 59 seconds) at Kitty Hawk on December 17, 1903 (which our speaker didn’t mention). By 1904, they had a model that would fly for 35 minutes – above the treetops. This prompted them to approach the Army with the goal of making airplanes for military purposes, but the Army wasn’t yet interested; however, the military’s attitude had obviously changed by 1909, when the U.S. Army Signal Corps offered $25,000 for a craft that could fly 40 mph, carry two people, and carry enough fuel to travel 125 miles.

  The Wrights had built seven models between 1907 and 1909, and they demonstrated their entry at Fort Meyer, Virginia in 1909. Orville flew their “Model A” on a 10-mile round trip at 42.5 mph, for which he earned a bonus of $5000 for the extra 2.5 mph – making the final purchase price $30,000. The following year, their Model B, which was the first one having a single elevator on the rear, also had its skids supplemented by a pair of wheels. In 1911, Galbraith Perry flew the Wrights’ Model Ex across the United States. It took him 49 days. Dr. Gorla showed us a number of their successive models, including a Model G Aeroboat in 1913, designed by Grover Leoning under Orville’s supervision. The Model G was the first one with an enclosed fuselage.

  After reviewing in some detail the effects of body and wing shape and angle on lift and drag and even the effect of viscosity of the medium (and their relation to everything from experimental solar vehicles to the dimples on golf balls), Dr. Gorla switched our attention a century forward with a cavalcade of slides of military aircraft, as well as several hypersonic models ­­– some of which had a maximum velocity of Mach 3, others Mach 5, and a missile, built for NASA, which could travel seven times the speed of sound.

  Curiously, he never mentioned the Wrights’ principal competitor, Glenn Curtiss, inventor of ailerons on his first airplane, the June Bug, built in cooperation with Alexander Graham Bell in 1908. (These wing flaps were copied by the Wrights in their 1915 Model K, after a lawsuit that had lasted for years. The Wrights’ eventually won, claiming that their patent on controlled wing twisting covered Curtiss’s innovation.)

  Interestingly, like the Wright Brothers, Curtiss’s inventive career began with building bicycles – but later motorcycles, one of which he raced at 137 mph. By1904 he was building engines for dirigibles. In 1910 he won a $10,000 prize by flying one of his planes from Albany to New York City in two hours. And in 1911, his company, the Curtiss Airplane and Motors Corp., began building planes for the Navy, after demonstrating that they could land on and take off from ships. In 1929, his company merged with the Wright Brothers’ firm, becoming Curtiss-Wright. By the end of World War II the company had become the largest manufacturer of aircraft in the United States.

  And about that collection of Wright Brothers photographs, one of our visitors from the Cleveland Astronomical Society gave your secretary the magic code: “Ohiolink.” (Just Google it.) One gem to be found is a photo of their glider at Kitty Hawk launching off what is perhaps a 16-foot cliff with one of the brothers clinging to the bottom.

Jack Gieck

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Akron Physics Club

Newsletter

Meeting Announcement: MONDAY, September 27, 2010 - TANGIER, 6:00 PM



Speaker for our first meeting of our new season (just five days after the Autumnal Equinox) will be Dr. Sheila G. Bailey, Senior Research Physicist at NASA’s Glen Research Center.

Dr. Bailey will be talking to us about:

THE FUTURE OF SPACE PHOTOVOLTAICS

Dr. Bailey has been a senior physicist working in photovoltaics at NASA Glenn Research Center for 25 years. Her most recent projects include nanomaterials and nanostructures for space photovoltaics, quantum wire III-V solar cells and quantum dot alpha-voltaics. She has authored or co-authored over 165 journal and conference publications, 9 book chapters and she has earned two patents. She was the chair of the 4th World Conference on Photovoltaic Energy Conversion in 2006 and is executive vice president of the Lewis Engineers and Scientists Association. She was awarded the NASA Exceptional Service Medal for her work in space photovoltaics and was inducted into the Ohio Women’s Hall of Fame in 2003 by then Governor Taft.


Minutes, September 27, 2010

  Twenty one people attended, including our speaker and two students, who were introduced by Darrell Renneker and Dave Sours.

  Chairman Ernst von Meerwall called the meeting to order, mentioning that Jack Geick, who has been Secretary for many years, is still recuperating, and is hoping to attend meeting when able.

  Bob Erdman is now Secretary, as well as liaison to ACESS, the Akron Society of Engineering and Scientific Societies. He reported that other scientific organizations who use the Tangier are having similar concerns to ours about the long-term viability of this meeting space. They are not serving the public on most nights, so they require a 20-person minimum, since they call in staff specifically for the meeting. We plan to keep abreast of the situation.

  The Dan Galehouse, Treasurer, assured us that money coming in and going out is all in order and in Tupperware box. We have $280.21 left after paying for dinners tonight and the new recorder belonging to the club [used to generate these notes, costing $91.06]. In response to a question, Dan stated the Student Dinner Fund amount remaining is $61.00.

  Charles Lavan, Program Chair, solicited ideas for future programs. Dan Fleisch of Wittenburg Physics Department will be the October speaker. His topic will be physics in the Renaissance. Clair Rimnak, Associate Dean of research at Case Western Reserve University will talk about the physics of Musculo-skeletal systems. See meeting announcements for specific information. More later on future programs.

  Chairman Ernst opened a discussion on the value of talks on methods of teaching physics. Contact Ernst via email with your comments. He also requested email responses related the thoughts of George Boehm in a communication to us.

  Ernst turned over the introduction of our speaker to Charles Lavan, program chair, who introduced our speaker, Dr. Sheila Bailey, a leader in photovoltaic research and developments whom Charles has known for years. She has authored 9 book chapters, over 165 papers on the topic and 2 patents, in addition to chairing international conferences on photovoltaics. She was educated in the U.S. and after receiving her PhD in England did her post-doctoral work in Australia. She was affiliated with Baldwin-Wallace College for 27 years where she received the Faculty Excellence award, has been awarded the NASA exceptional Service Award for her work on space photovoltaics, and has been involved with numerous international technical committees. She was inducted into the Ohio Women’s Hall of Fame.

  Dr. Bailey discussed The Future of Space Photovoltaics. Her focus at NASA for many years has been looking at space power systems, for the space station, space vehicles and also for planes. Recently she has been involved in ground-based renewable energy systems as part of the “green” initiative by the U.S. Government. This led a new 2kW photovoltaic power system at the NASA Glenn Research Center, and 2 wind generators.

  Modern solar cells were originally developed by Bell Labs in the early 1950s. The first products utilizing solar cells were experimental “almost toys”. After the Russian battery-powered Sputnik, in 1957, the U.S. launched Vanguard One, powered by solar cells. It lasted 6 years. Alternative systems utilized batteries which lasted for 2 hours. Thus the solar cell market was born.

  Mars rovers utilize solar cells. So does the Space station. Future plans for activity on the moon and on Mars would both utilize solar cells. They are useful for powering space travel toward or away form the sun, within in the limitations of the one-over-R-squared relationship between energy and distance form the sun.

  The space station is now fully functional, utilizing 262,400 silicon solar cells to power it. Dr. Bailey passed around a sample. These cells were designed based on technology of the early 1980s, using a boron-doped p-type base, with a small amount of phosphorous doped into it, making an n on p cell, covered with a glass layer that will withstand solar wind, space radiation, protons and neutrons in space. The assembly is only 0.2 mm thick. Dr. Bailey showed us a complete solar panel as is used on the space station. The connections had to be coated because the plastic connectors were eroded by atomic oxygen in space. The space station power system, monitored at NASA Glenn, is large enough to power about 55 houses.

  Today improvement in solar arrays and structures have been developed. The Phoenix Lander that went to Mars uses a Cu-In-Ga-diSelenide on polyimide solar cell. The Deep Space 1 probe utilizes an 8:1 concentrator array, utilizing a fresnel lens, about 0.5cm wide. These and space station arrays are sent up collapsed, and expand in place in orbit.

  Cell efficiencies on the ground are better than in space, due to the spectrum shift toward blue. The cells now of choice are triple-junction cells that are 32% efficient on the ground, 30% efficient in space; a significant improvement over the 6% efficiency of the solar cells based on 1980s technology. In today’s cell, the short wavelengths are absorbed by the top cell, and most other wavelengths by the intermediate cell, and the long wavelengths by the Germanium cell on the bottom.

  If monolithic amorphic cells could be grown reliably without defects, efficiencies could be significantly improved over the present 30%. This technology has not yet been perfected. Dilute nitrides have been considered, but they too are difficult to grow. Splitters that split the incident radiation into different wavelength bands that can be matched to solar cells optimized for that range of wavelengths.

  Quantum-confined devices have the most promise in Dr. Bailey’s mind. This is an area she has been working on recently. Another issue for any type or array is the total cost, part of which is related to weight. It costs $10,000 to put 1 pound in to space. So lighter is better. It costs about $1000 per watt to put a power system into space. Even with the multi-cell structures, it is felt that it will not be possible to get more than 35% efficiency, combining all the techniques discussed above.

  The quantum-confined devices utilize quantum dots in the middle of a cell, reducing the energy required for an electron to hop between shells in the atom, making the cell able to utilize a wider band of wavelengths. The quantum dots are selected to be of a size such that an electron can hop from the valence band to an intermediate band [provided by the quantum dots] and then to the valence band. This permits utilizing more of the spectrum, since it is not necessary to match the solar cell band gap. It is only required that the energies only to be less than the band gap, not matched to it. This would enhance the end-of-life efficiency.

  They are working on growing quantum dots of about 5 nm diameter. 45% efficiency is predicted for only 1 band [layer] in space, 50% on the ground using this technique. They have grown In-As dots. Using different size dots, you can tune to different wavelengths. Added layers provide higher efficiency, but each layer introduces an additional strain. It looks like this structure can be developed into a workable high-efficiency cell, using multiple layers of quantum dots. Some projections indicate up to 100 layers may be possible. So far 40-layer cells have successfully built. Further doping is also being experimented with, using Si doping in the dots. One of the issues is that there seems to be better radiation resistance utilizing the quantum dots. Another issue being experimented with is collection at the side of the cell, not on the main cell plates. This could further improve efficiency.

  As more is learned about nanostructures and materials are further developed, solar cell efficiency and reliability in space will be improved.

In response to questions, Dr. Bailey commented that:
* Many laboratories are working on the quantum-dot solar cells, such as Imperial College London, and the Frauenhofer Institute in Germany.
* Another direction is to attempt to reduce the cost per watt of power systems significantly below the present $1000/watt cost of a space power system.
* Carbon fiber may replace copper as a connection material. There are construction and reliability problems.
* Higher voltage arrays coupled with built-in inverters to directly provide ac may help efficiencies. But arcing can be a problem.

  We thanked the speaker for her excellent presentation.

  Submitted by Bob Erdman, [the new] Secretary.

  Please send comments to This email address is being protected from spambots. You need JavaScript enabled to view it.

  

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Akron Physics Club

Newsletter

Meeting Announcement: MONDAY, October 25, 2010 - TANGIER, 6:00 PM



Speaker for the meeting will be Dr. Daniel Fleisch, Professor of Physics, Wittenberg University, whose presentation is entitled The Science of the Renaissance.

He will present examples from the renaissance era of difficulties at the interface between science and religion. But the full story is more subtle and more interesting than the traditional account. As it was obstructing the spread of the Copernican worldview, the Church was simultaneously funding an ambitious program of astronomical research. As part of that program, several of the great cathedrals of Europe were converted into solar observatories containing the most advanced astrometric instruments of the era.

In this presentation, Prof. Fleisch will explain why and how the Church was following these seemingly contradictory paths, illustrated with pictures of the recently restored meridian line in the Basilica of Santa Maria degli Angeli in Rome. He will also share his (at times amusing) experiences with the development, publication, and delivery of his line of Student’s Guides from Cambridge University Press.

Dan Fleisch is an Associate Professor in the Department of Physics at Wittenberg University, where he specializes in electromagnetics and space physics. He is the author of A Student's Guide to Maxwell's Equation [!]and is co-author of the textbook, Electromagnetics with Applications – plus dozens of articles in refereed journals. That his teaching style is unique was illustrated in an interview in which he admitted that “I do have a bit of a reputation at my university for doing whatever it takes to help a student understand physics. For example, I once rented an ice-hockey rink and paid some professional hockey players to accelerate, turn sharply, and shoot the puck while students measured their motion using video cameras and a radar gun.


Minutes, October 25, 2010

BUSINESS MEETING:

  28 People attended the meeting, including one new guest and two students who were with us last month. Jack Gieck returned after illness, and Alan Gent joined us this time. Charley Wilson’s son Will from Canada joined as us well. We were glad to see them all again.

  Dan Galehouse, Treasurer, reported that $268.45 was in the treasury after last meeting. A net gain of $9 from today’s meeting leaves $277.45 in our Rubbermaid treasury.

  Chairman Ernst von Meerwall thanked Bob Erdman for taking over the Secretary position. Bob appreciated the credit.

  Charles Lavan, Program Chair, reported that Clair Rimnac will talk next month about the physics of musculoskeletal material [See separate announcement]. There is no meeting in December. Dr. Dan Galehouse will talk in February on the Pauli Exclusion principle. Charles is working on speakers for 2011, including possibly Owen Lovejoy.

INTRODUCTION OF TONIGHT’S SPEAKER:

  Charles Lavan then introduced Dr. Dan Fleisch from Wittenberg University, tonight’s speaker. Charles heard of him through listening to Stewart McClain on Canadian Broadcasting who was interviewing him. We are very pleased Dr. Fleisch made space in his busy schedule to drive up here from Springfield Ohio to present this discussion. He has won many awards, and invites students to his home for “quality circle” discussions in order to assure his classes are the best possible learning experiences. He is known for very demonstrative and interesting physics experiments which the students enjoy. Details of his extensive experience are in announcements issued previously for this meeting, including his book: A Student’s guide to Maxwell’s Equations. He said he appreciates people who lead a “life of the mind” and encourages his students in this direction.

NOTES ON Dr. FLEISCH’S TALK:

VIEWS OF THE UNIVERSE:

  Around 150 AD, the view of the universe was primarily that developed by Claudius Ptolemaeus. It was a geocentric [meaning earth-centric] view, with the moon, sun and planets and further out “the firmament” [all the stars in the heavens] revolving around the earth.

  They noticed “retrograde motion” in epicycles, whereby the planets move one way with respect to the background stars, then reverse. The actual point around which everything rotated was recognized as not being the earth, but a point near the earth.

  Copernicus had a heliocentric view of the universe, with the sun at the center. Planets out to Saturn were identified. These were still assumed to be in circular orbits. No one had yet identified Uranus in 1550AD, although it was visible the naked eye. Copernicus felt that this view could be considered heresy, and did not want it published, but it finally was published in 1543. Gingrich from Harvard wrote a book about this called “The Book Nobody Read”. He found many copies belong to other Scientists of the time with extensive notes in their copies, indicating that the scientific community of the day referred to it extensively.

  So between 150AD and 1550AD, there was mounting evidence that the models being used may not be correct.

  Galileo heard of the telescope invented in Holland, and put his own together. He was the first to use the telescope to look at the night sky. He identified that the orbit predicted by Copernicus may be more correct than the geocentric view, that the moon and sun are not smooth spheres, and that other planets, such as Jupiter, had moons. Galileo published “Siderius Nuncius”, [the Starry Gazetteer], in both Latin and in Italian.

  This famously got him into trouble with the Roman office of the Inquisition. They referenced Giordano Bruno, who was burned at the stake for his view that stars looked like suns far away, and they probably have planets around them too, and perhaps people on the planets. Such ideas were not at all popular with the Roman leaders, leading to Bruno’s demise. So Galileo said he would not hold these ideas, nor teach nor write about the Copernicus system or his aforementioned beliefs.

  When a new Pope was installed, whom Galileo knew, he published a “hypothetical dialogue” with Simplicico, a church man, having weak arguments for the old geocentric view, and two others, a proponent of Copernicus’ ideas, with strong arguments, and a “straw man” impartial person who commented on the validity of this latter view. In 1532, Galileo was 70 years old. He was tried for publishing these ideas, and sentenced to house arrest, in a farm house near Florence, a short distance from where his daughter was in a convent.

MEASUREMENTS USED TO DEFINE CALENDARS:

  Easter is defined as the first Sunday after the first full moon after the vernal equinox [which is the first day of spring]. From one vernal equinox to the next is a solar year, 365.2433 days. New moons are 29.53059 days apart [a synodic month]. In the Council of Nicea, 325 AD, it was agreed that the year will be 365.25 days, with a leap year every 4 years. The difference between 365.25 and the actual 365.2433 days is about 11 minutes per year. This meant that by 800 AD, the ides of March was occurring on the 17th of March, not the 15th, as it was supposed to be, and this lack of accuracy was a big problem because the church calendar needs to be known forever. The start of the new moon every month was referenced to the half moon and the full moon times, which defined the ides of March on the 15th.

  They wanted to do some actual measurements to confirm these calculations. They used a large pinhole camera, built into Santa Maria degli Angeli e dei Martiri Basilica in Rome to do this. It projected the sun through a small hole onto the floor. A trough of water was used to assure the floor was level, where they plotted the meridian line of the sun, identifying the summer and winter solstice and spring and fall equinox. This was done at the time Galileo was under house arrest. Using a telescope, the North Star can also be viewed through another hole in the wall of this church, in the daytime, since all outside light is blocked. The walls of Diocletian baths, built 1800 years before, were used as the basis of this church. Due to the age of this wall, it did not settle further. The southern exposure of this wall was important to being able to get sunlight all year long. The church was designed by Michael Angelo. It is at the end of Via Nationale in Rome.

  Dr. Fleisch explained the celestial sphere as an extension of the earth’s spherical axes: That is, the north-south axis extends beyond the earth into celestial space, and there is a celestial equator, an extension in all east-west directions of the earth’s equator. When standing on the earth, say at 40 degrees latitude, a tangent plane can be drawn to this point, which will intersect the celestial sphere, defining the horizon. From this reference, the North Star is at the same angle above the horizon as the latitude at which the plane is drawn. Circumpolar stars are close enough to the north celestial pole that they are always above the horizon, rotating around the North Star; other stars in the lower latitudes rise and set above the horizon defined by the tangent plane on the earth at the observer’s position. Zenith is the position directly overhead of the observer. All stars are sufficiently far away that there is no parallax error due to different positions on earth. In the summer, the sun has a higher zenith than in the winter, but it is always in the south. In the Renaissance and even in Ptolemaeus’s time, all these things were understood.

  Using the pinhole camera in the Santa Maria degli Angeli e dei Martiri Basilica, they compared the diameter of the sun at winter solstice and summer solstice to show that the Keplarian system of elliptical orbits was more accurate than the Ptolemaic system using circular orbits. They also accurately predicted the motion of the North Star within about 1 minute of arc over the 300 years since the meridian line was installed. Their projections go out to the year 2500. These projections back in the 1700s indicate a very sophisticated understanding of astronomy, and they are still accurate today. These topics are very thoroughly described in a book entitled The Sun and the Church, Harvard press, 1999. Other meridian lines in Paris and Bologna are referenced in the Book.

IN RESPONSE TO QUESTIONS, Dr. Fleisch commented as follows:

* The height of the pinhole was determined by the available length of space for the meridian line. A plumb line was dropped from the hole to locate the start of the line.
* The size of the hole was about 1cm, large enough to get a reasonable amount of light, and not so small that light diffraction occurs.
* A lot of material related to Galileo was burned by the church. His daughter’s letters indicate he was a good father and a kind man.
* Dr. Fleisch worked with John Kraus at Ohio State on his book Elctromagnetics [I took electromagnetics courses from Dr. Kraus around 1960, using an earlier edition of this book], and through this got involved with Maxwell’s equations. Much of Maxwell’s notes were on the back of student’s exams.

SOME OF Dr. FLEISCH’S PUBLISHING EXPERIENCES

  He approached Cambridge Press with the idea of Student’s Guide to Maxwell’s Equations, costing under $30, with podcasts explaining every page, and internet links for homework. The interview room he waited in had pictures of past books they have published by Isaac Newton, Albert Einstein, Steven Hawking, and many others icons of physics. It was a humbling experience. Once they accepted his book, they said it would be about 9 months before they reprinted it. But Amazon.com gave it very good reviews. After 2 years, they are on the 8th printing. Cambridge decided to print some in the US.

  On Christmas Eve December 2008, his ratings suddenly declined. He noticed a review on Amazon.com saying 40 pages were missing from the reviewer’s copy of the book, and he could not give it as a gift. Dr. Fleisch flew to Ottawa, drove to the Reviewer’s house, and stood at his door on Christmas day. Dr. Fleisch asked him “do you want paperback or hardback”. Dr. Fleisch replaced his copy, then flew back home. NPR ran a story on his trip. Stewart McClain of Canadian Broadcasting gave the first award for doing crazy but wonderful things to an American to Dr. Fleisch, because he heard the NPR report about this Christmas trip.

  We thanked the speaker for his fascinating presentation. He hopes to bring some students to our February meeting to hear about the Pauli Exclusion Principle, and said we are welcome to visit anytime anyone is in Springfield [OH].

  I have a copy of the PowerPoint slides for the talk, which Dr. Fleisch said could be forwarded to anyone interested.

  Submitted by Bob Erdman, Secretary. Thanks to Ernst von Meerwall for his improvements. Please send comments or questions to This email address is being protected from spambots. You need JavaScript enabled to view it.

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Akron Physics Club

Newsletter

Meeting Announcement: MONDAY, November 22, 2010 - TANGIER, 6:00 PM



Engineering the Natural History of
Total Joint Replacements
Clare M. Rimnac, Ph.D.

Departments of Mechanical and Aerospace Engineering and Orthopaedics
Case Western Reserve University
Cleveland, OH

Total joint replacements for the hip and knee are typically composed of a metallic component articulating against a plastic (ultra high molecular weight polyethylene) component. A significant long-term complication in total joint replacement is loosening, which has been linked to the biological response invoked by debris generated from wear of the polyethylene component. New, highly crosslinked formulations of polyethylene that are very resistant to the generation of wear debris have been introduced into clinical use. Clinical findings support that wear is greatly reduced in total hip replacements using highly crosslinked polyethylenes. However, structural fracture of these devices is a concern, due to a reduction in ductility and static and cyclic fracture resistance of these materials. Thus, there is a need to be able to prospectively predict the propensity for fracture for current and new component total hip and total knee replacement designs that make use of both traditional and highly crosslinked polyethylene formulations.

We have taken a comprehensive approach to determining and influencing the “natural history” of polyethylene components in total joint replacements, through: 1) evaluation of in vivo performance of retrieved polyethylene components to identify factors affecting wear damage and fracture; 2) identification of failure mechanisms leading to wear damage; 3) determination of static and cyclic mechanical properties of polyethylene; and, 4) prediction of the effects of changes in design variables on structural performance. Progress and findings in these on-going areas of investigation will be presented.

Clare Rimnac is the Wilbert J. Austin Professor of Engineering and Associate Dean of Research of the Case School of Engineering at Case Western Reserve University in Cleveland, Ohio, USA. Previously, she was Chair of Mechanical and Aerospace Engineering. She also holds secondary appointments in Biomedical Engineering and Orthopaedics. Prof. Rimnac received her B.S. in Metallurgy and Materials Science from Carnegie-Mellon University in 1978, and her M.S. in 1980 and Ph.D. in 1983 in Metallurgy and Materials Engineering from Lehigh University. Prior to her faculty appointment at CWRU in 1996, she was a Scientist in the Department of Biomechanics at The Hospital for Special Surgery in New York City. Prof. Rimnac’s research is funded by the NIH, orthopaedic industries, and private foundations, including the Musculoskeletal Transplant Foundation. Her research is directed towards orthopaedic biomechanics, with a focus on implant retrieval analysis, mechanical behavior and modeling of materials used in total joint replacements, and damage and fracture behavior of bone tissue. She has published more than 95 peer-reviewed articles and book chapters. Among other honors, Prof. Rimnac has served on two NIH study sections, is the recipient of an American Academy of Orthopaedic Surgeons Kappa Delta Award, two Hip Society Awards, and a Knee Society Award. She was a Deputy Editor for the Journal of Bone and Joint Surgery and is currently the President of the Orthopaedic Research Society.


Minutes, November 22, 2010

BUSINESS MEETING MINUTES:

  20 People attended the meeting. Dan Galehouse, Treasurer, reported that we gained $1.00 in the treasury from this meeting, thus our balance went from $277.45 to $278.45.

  Mike Dowell, Chair of ACESS reported that over 200 people attended the ACESS Award Banquet. Dan Galehouse and Bob Erdman, our liaisons to ACESS were among the attendees. 60 awards were presented to outstanding high school students as well as about 15 scholarships and grants valued at up to a few thousand dollars.

  Charles Lavan, Program Chair, reported that Dr. Owen Lovejoy will not be in this area until spring. In January, Dr. Michael Fisch will talk about the KSU Electron Beam facility in Middlefield OH, which is in Amish country. In February, our own Dr. Dan Galehouse will discuss the Pauli Exclusion Principle. In March, Dr. Klaus Fritsch from John Carroll will present a discussion on sonoluminescense. [Note: This did not work out. In March, we will Have Dr. Steven Hauck II from CWRU talking about the MESSENGER PROGRAM and geophysics of planetary structures.] In April, Kumar Pallei will discuss ultrasound physics in medical applications, and in May Dr. Owen Lovejoy from KSU will update us on Ardi and Bipedalism. [Information has been updated since the November meeting.]

INTRODUCTION OF THE SPEAKER:

  Charles Lavan then introduced Dr. Clare Rimnac, the Wilbert J. Austin Professor of Engineering and Associate Dean of Research of the Case School of Engineering at Case Western Reserve University in Cleveland. Previously, she was Chair of Mechanical and Aerospace Engineering. She also holds secondary appointments in Biomedical Engineering and Orthopaedics. Prof. Rimnac has degrees in Metallurgy and Materials Science and Materials Engineering. Prior to her faculty appointment at CWRU in 1996, she was a Scientist in the Department of Biomechanics at The Hospital for Special Surgery in New York City. Prof. Rimnac has published more than 95 peer-reviewed articles and book chapters. Among other honors, Prof. Rimnac has served on two NIH study sections, is the recipient of an American Academy of Orthopaedic Surgeons Kappa Delta Award, two Hip Society Awards, and a Knee Society Award. She was a Deputy Editor for the Journal of Bone and Joint Surgery and is currently the President of the Orthopaedic Research Society.

SUMMARY OF Dr. RIMNAC’S PRESENTATION:

  Total hip replacements [THR] and total knee replacements [TKR] are the most frequently reported types of musculo-skeletal impairments. About 600,000 of each were reported in 2005. Dr. Rimnac's work can also be used for other joints, such as shoulder and great toe replacements. Typically the cartilage and/or bone surfaces become diseased or fractured, requiring a total replacement. Replacements are typically made of metal articulated against plastic parts. The modern types of replacements first appeared in 1963. Prior to then, the metallurgy was highly susceptible to fracture. Coefficients of friction of replacement parts using plastic and metal have about ten times higher coefficient of friction than the natural components. This creates more bone loss than normal. The replacement components do show wear and tear, but over 90% are not rejected by the body and last for more than 10 years. Failures can occur due to problems such as fractures, loosening, repeated dislocations, and loss of bone material [osteolysis].

  Dr. Rimnac’s focus has been on commonly-used Ultra-High Molecular Weight Polyethylene [UHMWP] components, with a molecular weight of over 2 million. The work particularly focused on minimizing the debris from the plastic. Once the metallurgy was working well, the plastic properties became an important issue in the 70s and 80s. The success of the replacement is dependent on the patient’s weight, activity, bone strength, soft tissue balance of ligaments, etc., and the surgeon’s success at properly positioning and aligning the structures to provide appropriate range of motion, etc. In Dr. Rimnac’s laboratory, artificial joints removed from patients are analyzed to determine wear and other issues. They analyze about 100 hip or knee replacements annually. She showed pictures of various kinds of damage analyzed. Case Western Reserve University [CWRU] is attractive for this work because of the combined medical and engineering disciplines. Her work is shared with other research establishments in order to get a comprehensive view of all issues involved.

  Cobalt and chromium are the most commonly used metals, with some molybdenum for the components. These are easy to cast and have better wear resistance than titanium/vanadium which is sometimes used. “Bone Grout” is used to cement the bone to the components. This sets up in about 12-15 minutes. Another method is design porous surfaces on the metal, so the bone grows into the metal. Today’s UHMWP has a typical molecular weight of 4 to 6 million. To sterilize it, gamma radiation is used. This generates cross-linking, and also generates free radicals, esters, acids and other unwanted substances and can create cracks and delamination in the plastic which can persist for years. Today inert packaging is often used so the plastic parts are not exposed to oxidation. This addresses the issue of components becoming more oxidized as they sit on the shelf.

  As the replacement wears, small particles are generated from the frictional wear. About 100 million small particles per day can be generated, as a result of the operation of hip joints a few million times a year. Significant force is involved, about 3 times body weight if standing on one leg, 5-6 times body weight if going up stairs. These small particles end up inside of cells, particularly “macrophage cells” which take in debris. After many years, this in turn generate osteoplasts which remove bone tissue, making the joint “wobbly” or loose. This accelerates wear and bone loss. Normally osteoplasts remove bone tissue, and osteoblasts rebuild it. In this case, the osteoplast activity exceeds the osteoblast activity, resulting in net bone loss. The cross-linking resulting from radiation increases the wear resistance but also makes the material more brittle. This is aggravated if more free radicals are present. This represents a trade-off between wear resistance and fractures resulting from brittleness. Today the process used is basically to cross-link with radiation, then remove free radicals. This can be done above [called re-melt] or below of the melt point [called annealing]. Future work will focus on crack reduction, and methods of developing better brittleness indicators in new design.

  Dr. Rimnac handled many questions during the talk, some of which are included in the above summary. If you want more detail on these topics, a copy of the slides for this talk is available by contacting me at This email address is being protected from spambots. You need JavaScript enabled to view it.

Submitted by Bob Erdman, Secretary.