ACS New York Section

High School Teachers Topical Discussion Group


2008 Annual Report



JANUARY 2008 MEETING

Dr. Stephen Gould, U.S. Environmental Protection Agency, <Gould.Stephen@epamail.epa.gov>, “Introduction to Corrosion: What it is, why it is of such concern, and some of the places it occurs in everyday life.”

         On January 11, 2008, Dr. Stephen Gould <gould.stephen@epamail.epa.gov> spoke about types of corrosion associated with iron, aluminum, and copper. By addressing problems corrosion can cause, methods of prevention, and demonstrations that highlight aspects of the corrosion process, Dr. Gould provided an observation-based approach to examining corrosion and its influence in industry.
         The term “corrosion” is derived from the Latin corrodere, meaning “to gnaw away,” and NACE International defines it as “the deterioration of a material, usually a metal, that results from a reaction with the environment.” A metal may lose electrons and go into solution as an ion, or, if no moisture is present, may share electrons with oxygen or sulfur in its surrounding environment. Although often viewed as a gradual process, in many cases it occurs rapidly: for example, when sodium is cut it initially appears shiny, but a beige coating forms within seconds of exposure to oxygen as the oxide forms.
         To demonstrate the tarnishing (corrosion) of silver, let a hard-boiled egg sit at room temperature overnight, remove the shell, cut it in half, remove the yolk, place on a silver try, cut side in contact with the silver, forming a dome. The dome traps the hydrogen sulfide gas (a product of decay from the egg-white) forming silver sulfide (silver tarnish). Because silver is less active than sodium, though, it releases ions to a lesser extent in solution and takes longer to visibly corrode—about an hour.
         Probably the most common notion of corrosion is rust, which proves not only a cosmetic problem but also an obstacle in construction and gasoline storage. It caused the collapse of the Silver Bridge along the Ohio River that led to 46 deaths, and underground gas tank corrosion contaminated half the water supply in Santa Monica, CA. In fact, a 2002 study by the Federal Highway Administration concluded that in the U.S. corrosion costs owners of structures, manufacturers of products, and suppliers $276 billion per year—three percent of the GDP.
         Dr. Gould modeled a demonstration that strikingly shows the early stages of rusting. A nail is placed in a hot solution of gel (like agar or Knox gelatin) and pure NaCl. (Kosher, not table salt; read the list of ingredients on the label.) When the solution has cooled to room temperature, phenolphthalein in isopropyl alcohol and potassium ferricyanide are added. This gel mixture is poured into a Petri dish, and an iron nail is place in the dish. As rusting occurs, a blue precipitate (Prussian blue pigment, potassium ferriferrocyanide) forms around the tip and head of the nail where iron is oxidizing and going into the gel; and phenolphthalein will turn bright pink elsewhere along the nail where excess electrons reduce oxygen to form hydroxide ions. Corrosion begins at the tip and head, the highly stressed parts, and the gel keeps the products of the reaction separate.
         A few methods of corrosion prevention were also described. Metal can be coated with polyurethane or wax (as is used in museums on armor), or an alloy can be used (as in weathering steel, which forms a dense and adherent run that shields the underlying iron from further corrosion). In fact, the Iron Pillar of Delhi has not rusted in 1600 years, possibly due to five times the customary phosphorous content; and New York City manholes that contain two to four percent silicon or carbon are shielded by products formed during and after casting that retard further oxidation.
        Additionally, a common preventative innovation is cathodic protection, in which a more active, “sacrificial” metal serves as an anode to resupply the “valuable” metal with electrons. The metals must be bathed in an electrolyte, so cathodic protection is conveniently used to protect underground tanks, pipelines and hulls of ships. A dramatic demonstration for this principle is comparing corrosion of steel wool in a 3% salt solution to corrosion when magnesium and steel wool are immersed in a 3% salt solution—in the second case, steel wool remains unchanged as the magnesium corrodes.
        Unlike in iron, corrosion in aluminum results in formation of a transparent, adherent protective aluminum oxide coating that protects the underlying metal from further corrosion. However, chloride can destroy this coating—if a drop of copper sulfate is placed on aluminized Mylar, no visible corrosion occurs, but if salt crystals are added to the copper sulfate, the Mylar quickly wears away. The specific mechanism by which chloride attacks the aluminum oxide is still debated: chloride may break bonds at the surface, it may penetrate gaps in the coating, or absorption and ion displacement may lead to corrosion.
        Of the eight major types of corrosion (uniform corrosion, galvanic corrosion, crevice corrosion, pitting corrosion, intergranular corrosion, selective leaching (dealloying), erosion corrosion, and stress corrosion cracking), crevice corrosion is most associated with aluminum. It commonly occurs in aluminum screws as threads corrode due to restricted flow of corrosion products and difference in the environment and electrolyte concentrations inside and outside the screw crevices. This can be especially problematic because it results in loose screws, thus posing a safety hazard.
        The final metal Dr. Gould discussed was copper, which forms an attractive light-green patina when it corrodes. The most widely known example of this is the Statue of Liberty—although people were wary when it began turning green, it is now difficult to imagine the statue any other way. The color change took twenty years, but now formulations used by artists and architects can shorten the time required for patination; and environmental factors also contribute to speed. For instance, patination occurs more slowly in Hawaii than in other parts of the world because it is inhibited by sulfur in volcanoes; and if a copper bar is repeatedly rubbed, a patina will not form.
        Because of pitting corrosion in copper pipes, many homeowners have experienced frustrating pinhole leaks. Ironically, these may have been the result in part of EPA attempts to reduce lead and turbidity, leading to subtle changes in water chemistry. One focus of current research is how to prevent corrosion in pipes used to transport ethanol. It is also essential to explore corrosion-resistant materials for storing nuclear waste and for selecting building materials, and increased experimentation and understanding will enable this type of exploration in the future.
Chem Club Vice President Lew Malchick announced that the American Chemical Society is seeking volunteers for the weekend of May 17-18 to perform demos and foster discussion among participants in its Mid-Atlantic Regional Meeting (MARM) at Queensborough Community College. The Sunday program will be similar to the Chem Club’s annual “demo derby.” Those interested in presenting can find more information by visiting <www.marmacs.org> and by contacting Lew <bt_quant@yahoo.com>.


FEBRUARY 2008 MEETING


Dr. David W. Hogg, Associate Professor, Center for Cosmology and Particle Physics, Dept. of Physics, NYU <david.hogg@nyu.edu>, “Massive Data Sets in Astrophysics Including Sloan Digital Sky Survey.”

        Dr. David W. Hogg was unable to speak at the February 8 meeting due to illness, so Dr. John Roeder led an activity called “Jumping on the Moon,” part of an Active Physics course that is appropriate for all levels. The objective was to determine how high a person could jump on the Moon based on the height they can jump on Earth, and the discussion that ensued generated unique problem solving approaches.
        The National Academy of Sciences promotes the idea that students’ prior experiences enable their future learning, so Dr. Roeder recommended speculating about the question at hand before obtaining experimental data. The key fact to remember is that the Moon’s gravitational force is one-sixth that of Earth. Common conjecture was that on the Moon, the average person could jump to six times the height they reach on earth.
        However, examining the scenario more closely exposed another layer of the problem. When a person jumps, he first crouches the “ready distance,” reaching the “ready” position. He then extends his legs again, reaching the “launch” position. Finally, he travels the “peak distance” and reaches the highest point in his trajectory, the “peak” position. Regardless of the gravitational pull of his surroundings, his leg muscles will exert a relatively constant amount of energy each time he jumps. On Earth, much of that energy is used in order to overcome his gravitational mass and as he moves from the “ready” position to the “launch” position. In contrast, the Moon has a weaker gravitational pull, so not as much of the energy he exerts must be used to overcome inertia, and more of it can be converted to the kinetic energy that propels him the peak distance. As a result, a person on the Moon actually jumps more than six times the height of his jump on Earth.
        This concept can also be described using formulas that enable students to calculate the height of their jumps on the Moon based on their jump heights on Earth: The work done by a jumper equals the increase in his gravitational potential energy, which can be expressed as Mass x the gravitational field of the planet x (peak distance – ready distance). Because the work done is the same on the Moon and on Earth, the expression using Earth’s gravitational field can be equated to the expression using the Moon’s:
Mass x gravitational field of Earth x (peak distance on Earth – ready distance) = Mass x gravitational field of Moon x (peak distance on Moon – ready distance).  Mass and ready distance are the same on Earth and the Moon, and the ratio of Earth’s gravitational field to the Moon’s is 6:1, so dividing by the Moon’s gravitational field generates the useful form of the equation: 6 x (peak distance on Earth – ready distance) = peak distance on Moon – ready distance.
        Dr Roeder directed participants in taking measurements of their own jump heights (using a measuring tape and masking tape markers; all measurements are from the floor to the jumpers waist, the presumed center of mass) to gain a full understanding of this formula’s use. A more familiar example of the principle being investigated is a swimmer’s ability to jump higher in a pool than on land. Once students understand this concept, they can explore other aspects of the Active Physics program; for example, the program incorporates a “challenge” to introduce topics, like the task of inventing a game that can be played on the moon. Related discussions that might arise include the difference between falling motion on Earth and on the moon, the way the moon’s gravitational conditions can be simulated on Earth to test the game’s effectiveness, and the process by which one can plot and compare trajectories on the Earth and the Moon.
        Chem Club President Lew Malchick also announced a few upcoming events that are open to anyone interested: the Science Council of New York City is looking for volunteers to present on April 12 at Stuyvasent High School; the American Chemical Society seeks volunteers to present at a forum (similar to the Chem Club “demo durby”) that it will host on Sunday, May 18 at Queensborough Community College; and a meeting to be held at Columbia U Faculty House on February 26 will feature an AMNH associate curator discussing the chemistry of meteorites. Elections for the Chemistry Club board will be held in March, and the Chemistry and Physics Clubs are searching for a reasonably-priced, handicapped-accessible location for the annual awards dinner and welcome suggestions. In addition, UFT Science committee listserv users are encouraged to post anything of interest to the scientific community, like resources or questions.


MARCH 2008 MEETING

Dr. Julie Nucci, Director of Education Programs, Cornell Center for Nanoscale Systems,<jn28@cornell.edu>, “Getting a Charge out of Light.”

        At the March 14 meeting, Dr. Julie Nucci from the Cornell University Center for Nanoscale Systems, <jn28@cornell.edu>, delivered a presentation entitled “Getting a Charge out of Light: the Physics of Solar Cells.” This discussion of energy needs, solar energy supply, the physics of solar cells, and first, second, and third generation solar technology served as a comprehensive explanation of the working and possible uses of photovoltaic cells.
        Dr. Nucci began by stressing the motivation for developing solar cells: not only does reliance on fossil fuels for energy increase carbon dioxide emissions associated with global warming, but it also shows a lack of sophistication—why burn organic material for energy when astounding advancements in fields like microelectronics, informational technology, space exploration, biotechnology, and nanotechnology open revolutionary possibilities? Humans’ instantaneous yearly averaged consumption rate is 13 TW (1012watts), and assuming a world population of nine billion and energy conservation, by 2050 annual energy consumption is projected to reach 30 TW; but solar energy could potentially capture around 600 TW at any time. When compared with the mere two to four TW extractable energy that can be obtained from wind power, less than two TW power from ocean currents, and five to seven TW from biomass if all cultivable land were used, this figure shows the vast potential of solar technology to supply global energy needs.
         Solar energy can be divided into three categories: solar electric, which converts solar energy into electricity using the photovoltaic effect; solar heat, which uses a concentrator dish to achieve high temperatures or to split water molecules for H2; and solar fuel, which uses specialized cells to convert light into biofuels. The opportunity each of these three areas provides can be expressed as availability divided by current usage, and since photovoltaic energy is extremely available but only currently constitutes .015% of the world’s energy supply, it is the most opportune.
        The main obstacle inhibiting widespread use of this technology is its high cost of implementation due to the amounts of hardware required: over $0.30 per kW/h. Growth rate of global PV production is approximately 30% per year, and every time production doubles, it becomes 20% less expensive, but the current rate of growth will not serve global needs by 2050. Researchers are therefore seeking a fundamental change in the current technology to lower costs and improve efficiency.
        To introduce solar physics, Dr. Nucci used a mechanical analog in which a ball rolls down a hill that represents potential energy, and a “bubble” (or anti-ball) is propelled up the hill. Because an absence of electrons moves towards an area of higher energy, a charge separation occurs and produces voltage. In other words, when solar radiation interacts with matter, the atoms absorb photons and electrons can jump the gap to the conduction band.
        The voltage of a solar cell depends on the position of two bands. In semiconductors, silicon being the one most commonly used in solar cells, there is a small gap between the bands. The size of the gap decreases when the semiconductor is heated and its molecules move more quickly, which explains why semiconductors are better conductors at high temperatures. In the solar cell, a current is produced when electrons flow from the positively charged band to the negatively charged one. In intrinsic silicon, 1.1 electron volts are required to propel an electron to the opposite band.
        However, silicon’s valence of four makes it a poor conductor unless doping is performed—impurities like phosphorus (the n-type) and boron (the p-type) are added to the crystal. Phosphorous’ valence of five provides extra electrons, and boron’s valence of three creates holes that can be filled by flowing electrons. If the p-type and n-type are joined, an LED results—the chemical potential (Fermi level) must equilibrate, band bending occurs as a voltage gradient forms, carriers and holes move, and light is emitted. This is like a solar cell running in reverse.
        The voltage produced depends on the gap between bands, and also on the doping used. A famous analysis by Schockley and Queisser in 1961 attempted to determine efficiency in the solar cell assuming a single p-n junction, one electron hole per incoming proton, the thermal relaxation of electron-hole pairs, and illumination with unconcentrated sunlight. With these conditions, 30% efficiency is theoretically possible.
        Dr. Nucci also discussed three generations of solar design. In the first generation, silicon is used because the semiconductor industry can easily make it, but it is expensive and ranges from 6% to 41% efficiency. The second generation includes organic cells like dye-sensitized (mimicking photosynthesis), small molecule, and polymer solar cells; but the drawback of these is that they degrade. The third generation is a new approach and includes tandem cells and hot carrier cells, which are not yet mastered—the fundamental obstacles is that the energy being tapped degrades in 1014 of a second—but the idea of using quantum dots is also a new possibility.
        Although there is still much to be done in solar cell research, the developments Dr. Nucci described show the bright future of the field. Recommended sources for additional reading included Peter Wvertel’s Physics of Solar Cells, Jenny Nelson’s Physics of Solar Cells, and Antonio Luque Steven Hegedus’ Handbook of Photovoltaics.

APRIL 2008 MEETING

        “Demo Derby,” an evening of non-stop demonstrations (5-8 minutes max.) If you want to participate, just bring your demo, clean-up equipment and safety apparel. Write your name on the board. Remember, its quick, quick, quick. You’re not teaching, just showing what can be demonstrated in the classroom.   The April meeting is the annual “Demo Derby” featuring easy-to-do demonstrations with minimum equipment by members of the Chemistry Teachers’ Club of New York and the Physics Teachers Club.  The demonstrators in order of appearance were: Rudy Jones, Joan Laredo-Liddell, Judith Exler, Bob Capalbo, Myra Hauben, Jean Delfiner, Fred Newman, Mike Spalding, Steve Gould, Al Delfiner, and Jack DePalma.



SEPTEMBER 2008 MEETING


Gail Horowitz, Dept. of Chemistry, Yeshiva University, <ghorowit@yu.edu>, 212-960-5400 x6863, “Using the Digital Resources of the Journal of Chemical Education.”

        The invited speaker, Gail Horowitz, was unable to attend the September meeting to present on “Using the Digital Resources of the Journal of Chemical Education,” so the evening was spent discussing a variety of academic resources available to chemistry and physics teachers. Joan Laredo-Liddell, Al Delfiner, Jean Delfiner, Chris Ward, and Bob Cabalbo led the dialogue by recommending science-related events, print resources, demonstrations, and videos. Louis Pataki provided his laptop with NYU wireless access to the Internet.
        Mrs. Laredo-Liddell showed the two awards that the American Chemical Society’s New York Section (ACS NYS) received at the ACS Aug 2008 convention in Philadelphia for the work the NYS did in 2007 when she was section chair. For teachers interested in forming a Chemistry Club at their HS, the ACS offers a thick 3-ring binder with suggestions and resources. It is free for the asking. Check ACS.org on the Internet.
        The ACS NYS Brooklyn Subsection and St. Joseph’s College, Brooklyn, invites student researchers to enter their 14th Annual High School Poster Session on October 19 to present their work and to compete for one of four cash prizes. More information can be obtained at the college website <www.sjcny.edu/page.php/prmID/251> or email <JRehmann@sjcny.edu.
        The New York Hall of Science, Flushing, NY, the ACS NYS and the Pepsi-Cola Company are again cosponsoring student run demonstrations for National Chemistry Week at the museum on Oct. 25. If you and your students want to participate, contact David Sherman at <David.Sherman@pepsi.com>. Free parking and free admission for workers.
        Mrs. Laredo-Liddell suggested some publications that teachers should consider purchasing for personal and classroom use. A class set of Chem Matters, an ACS magazine published 4 times a year for HS students, and National Chemistry Week materials can be ordered through the ACS. Two intriguing books, “The Science of Chocolate” by Stephen T. Beckett. RSC Publishing – UK, ISBN: 978-0-85404-970-7 and “Molecules of Murder: Criminal Molecules and Classic Cases” by John Emsley, RSC Publishing – UK, ISBN: 978-0-85404-965-3, can be found on Amazon.com.
        Teachers who seek access to the Journal of Chemical Education without paying high fees to become a full ACS member can alternatively pay $40 to become a member of the Division of Chemical Education, which permits access to part of the JCE. “The Chemical Adventures of Sherlock Holmes” by Thomas Waddell & Thomas Rybolt, is a compilation of articles that appeared in the Journal of Chemical Education (1989 - 2004) is a volume containing stories that serve as a fun way to teach concepts like stoichiometry—it can be purchased through JCE.
        Mrs. Laredo-Liddell raffled off a year’s subscription to JCE. It was won by Bibiana Almache, Bronx Health Sciences High School
Mrs. Delfiner presented another important publication: the revised NYC K-12 Science Safety Manual, which came out in June 2008. Principals are responsible for ensuring that teachers abide by the manual’s guidelines, and students and parents should also sign an included contract. Although the manual is a lengthy, 135 pages, it is divided into chemistry, physics, Earth science, and biology sections, so teachers can focus on the section pertaining to their subject. A PDF version of the manual is available on-line. (See next article: Required Reading ... .)
        Mrs. Laredo-Liddell and Mr. Cabalbo also introduced a few quick demos. Mrs. Laredo-Liddell showed that the Hoberman “Switch Pitch,” a plastic ball that switches colors when tossed (interactive demo at www.hoberman.com/fold/Switchpitch/switchpitch.htm). It is a great way to visually explain concepts like activation energy and isomers. Another highlight was Mr. Cabalbo’s demo of surface tension. He replaced the metal seal on a Mason jar (available at most houseware stores) with a piece of window screen and then filled the jar with water through the screen. When he inverted the filled jar; some air entered and a little water leaked out and then stopped. Ambient air pressure plus surface tension on the screen balanced the pressure of the mass of water plus the reduced air pressure in the jar. Tipping the jar allows air to enter and water to leave. Straighten the jar so that water again covers the screen and the leaking stops.
       Mr. Ward generated a discussion when he raised the issue of developing effective practical sections for chem and physics Regents exams.
     Lewis Malchick found it and Mr. Delfiner showed a website run by the University of Nottingham called “Periodic Videos” (www.periodicvideos.com). This gem of a site contains short (1-4 minute) video clips for each element on the periodic table. The segments include properties, demos and amusing comments. They are updated regularly.


OCTOBER 2008 MEETING


Christopher Ward, Hommocks School, Mamaroneck, NY 10543, <Ward@mamkschools.org>, “Using Video Interactively in the Classroom.”

        Chris Ward < Ward@mamkschools.org >and WNET employee Toni Scheflin <schetli@thirteen.org> presented the educational resources that are available to teachers via < http://vital.thirteen.org >, a website sponsored by WNET and WLIW21 networks (more commonly known as Channel 13 and Channel 21). These resources include short video clips demonstrating scientific concepts, interactive flash media, standards guidelines, and lesson plans to accompany the media.
        Mr. Ward and Ms. Scheflin focused primarily on use of the site’s video resources. The typical length of a segment is three to five minutes, as the educational developers chose the most informative sections of longer videos. For each video, there are also corresponding “Questions for Discussion,” NY State and National Science Education “Standards,” and “Background Essay” tabs that can help teachers structure lessons using the videos. These features enable teachers to use video within the context of a traditional, discussion-based lesson.
        The site also allows teachers to create a “group” and to share “folders” of favorite links to videos and notes with any other teacher who joins that group. Teachers can also create a group with a folder of media, create a second account to give their students, and have students access the media from home. (Use the “Save to a Folder” option after navigating to the page of a useful segment.)
Mr. Ward has created a group for Chem Club members, which includes links to four “high-impact” videos in each of four subject areas: biology, chemistry, Earth science, and physics. It can be accessed by selecting “My Groups”‡ “Join A Group” and inputting the Group ID Number, 3878, into the search box.
        Mr. Ward demonstrated possible ways to use the site’s content as a springboard for classroom discussion. He stressed that one key benefit to showing short segments is that you can pause the video at any point to emphasize target questions and ideas. You can also play a video without sound and have a student narrate. These practices keep the viewing interactive and help keep students focused on the targeted concepts.
        Mr. Ward concluded by summarizing major components of putting these videos to use via his recommended method. Teacher preparation includes considering learning objectives, considering resources, previewing the segments, selecting “pause points” and “focus questions,” and planning post-viewing activities. To prepare students, teachers should ask thought provoking questions, prepare kids for segmented viewing, discuss major points covered in the clip, present relevant vocabulary, and list key concepts. The discussion should impress upon students that they are responsible for extracting information from the video.
        Ms. Scheflin said that Thirteen will host a professional development conference on the “celebration of teaching and learning” on Friday, March 6 and Saturday, March 7, 2009. There is a small fee for participation in the conference, and more information can be accessed at <www.thirteencelebraton.org>.

NOVEMBER 2008 MEETING

David Maiullo, Physics Support Specialist, Department of Physics and Astronomy, Rutgers the State University of NJ, 136 Frelinghuysen Road, Piscataway, NJ 08854, <Maiullo@physics.rutgers.edu>, 732-445-3872, “Physics Demonstrations as Theater.”

        David Maiullo, Physics Support Specialist, Rutgers University, presented a series of nearly 40 physics demonstrations. The presentation included both simple classics and less commonly seen demos.
        Mr. Maiullo began by discussing certain techniques for making demonstrations effective and exciting teaching tools. For example, he stressed the importance of finding out the limitations and available resources of the facility in which the demos will be performed (gas, water, electricity, sight lines, lighting possibilities, etc.). He also noted a few crucial do’s and don’ts for giving a demo show: do’s included using familiar devices, incorporating audience participation, and changing only one parameter during each demo, and don’ts included rushing, repeating failing demos, and being esoteric.

Ten particularly dramatic demonstrations were the following:
Table Cloth and Dishes – Dishes, a water-filled vase, and a candle were placed on a table that had been covered with a smooth, hem-less tablecloth. The cloth was then quickly yanked downward (to keep the force horizontal), but because of the inertia of the objects on the table, they remained almost perfectly in place.

Fire Extinguisher Cart - Conservation of momentum – Mr. Maiullo sat on a four-wheeled cart with a large CO2 fire extinguisher. When he discharged the fire extinguisher, he, the cart and the extinguisher were propelled in the direction opposite the stream of effluent.

Greek Waiter’s Tray - Water in glass swung in a circle – A wine glass filled with water was placed in the center of a tray, which was suspended by three cables. The tray was swung in a full circle over Mr. Maiullo’s head, but because of the centrifugal force, the glass remained on the tray, and no water was spilled.

Density: Diet vs. Classic Coke – A can of Diet Coke and a can of Classic Coke were placed in a tank of water. The Diet Coke floated—small air pocket in can. In contrast, the Classic Coke sank due—same air pocket but corn syrup more dense than water.. When Mr. Maiullo added salt to the tank, the density of the solution increased, so both cans floated.

Pressure of Atmosphere – A 55-gallon drum was evacuated using a vacuum pump, and it imploded with a dramatic, loud sound.

Fluid in Motion – A cylindrical garbage can had rubber stretched over one end, and a large hole cut out of the bottom. The can was filled with smoke with a commercial fog machine (atomized glycerin sprayed over a heating element) and held horizontally. When the rubber membrane was then struck , a ring of smoke was sent from the opening on the other end to the back of the room. The propelling force could be felt.

Flame Tube – A metal tube approximately 10 cm in diameter and 1.5 m long, with one end sealed by a loud speaker and the other end attached to a propane tank, and with a row of small holes along its length, was used to visually demonstrate sound waves. The tube was filled with propane, the gas escaping from the small holes was lit and the flame height adjusted to 2 cm. When the speaker emitted sound, a standing wave was established, and the height of the flames varied, correlating with the sound pressure at that point in the tube, enabling the audience to visualize a sound wave. When the frequency of the sound was increased, there were visibly a greater number of nodes and peaks.

Breaking Glass with Sound – A glass beaker was placed in a protective chamber and subjected to a variable frequency sound. When the sound frequency matched the beaker’s resonant frequency, the beaker shattered.

Magnet in Tube – Mr. Maiullo demonstrated eddy currents by dropping a small but very strong magnet into an open-ended thick walled copper tube. As eddy currents slowed the magnet’s downward motion, it appeared to “float” through the tube.

Bed of Nails – In a grand finale, Mr. Maiullo laid down on a beds of nails and placed a second bed of nails on his chest. He then had an audience member stand on top of the second bed. Because there were enough nails on the bed, the total force was distributed so that the force applied each nail was too small to do any harm.

Two resource sites for demo ideas, PIRA and the TAP-L listserv, can be accessed at:
 <http://physicslearning.colorado.edu/PiraHome/Resources.htm> and <http://www.eskimo.com/~billb/>, respectively. Mr. Maiullo also encouraged audience members to email him with further questions about any of the demos performed; his address is Maiullo@physics.rutgers.edu. Finally, he mentioned that Rutgers 10th Anniversary Faraday Christmas Children’s Lectures will be given at the Rutgers Physics Lecture Hall, 136 Frelinghuysen Road, Piscataway, NJ at 7:00 PM on December 12, 13, and 14.


DECEMBER 2008 MEETING

Dr. Jin Kim Montclair, Assistant Professor, Polytechnic University, Brooklyn, NY, <jmontcla@poly.edu>, “Bio Related Polymers.”

        Jin Kim Montclare, Assistant Professor, Polytechnic University, presented her lab’s research on bio-related polymers. The first part of this research aims to artificially engineer catalysts that could degrade plastic waste, and the second part involves designing artificial proteins for therapeutic use. The two projects could potentially ameliorate the problems of limited petroleum feed stocks and lack of “environmentally benign” solutions to waste accumulation.
        The study focuses on the group of biocatylists known as cutinases, which fungal plant pathogens excrete in order to burrow holes in leaves. The most commonly researched type is F. solani cutinase (FsC), a compound used in industry to modify fabrics. However, Dr. Montclair’s team seeks to expand the range of cutinases used for research and has focused on aspergillus oryzae cutinase (AoC), which has been used in Japan to ferment tsaki and tofu. The amino acid sequences of the two types of cutinases are 50% similar.
The team sought to identify the crystalline structure and to test the function of AoC in order to better understand its potential uses in industry and bioengineering. To examine the AoC’s secondary structure, the team compared its disulfide bonds, surface charge distribution, and hydrophobic surface distribution with those of FsC. Computer imaging revealed that AoC has one additional disulfide bond, but the active sites of the two proteins had the same stereostructure; so they can catalyze the same types of reactions. AoC also was found to have a slightly different area and charge distribution, and a more hydrophobic active site.
        To compare the functions of AoC an FsC, the team investigated rates of enzyme activity for PNP substrates using each catalyst. (These substrates were used because their decomposition is easy to monitor—solutions turn a yellow color.) It found that FsC prefers the p-nitrophenyl acetate (PNPA) substrate to p-nitrophenyl butyrate (PNPB) or p-nitrophenyl heptanoate (PNPH), while Aoc works fastest on PNPB and PNPH.
        The team also conducted a thermoactivity comparison, incubating the catalysts at a number of temperatures, comparing the heat capacities of the enzymes, and seeing what happened when the enzymes were denatured by heating and subsequently cooled. It found that AoC was more thermostable, that there was no difference in the two enzymes’ heat capacities, and that after being denatured, AoC can more effectively return to its original structure than FsC can.
         In the second part of the research, Dr. Montclare’s team used its knowledge of nature’s polymers (polysaccharides, proteins, and nucleic acids) to experiment with controlling a compound’s chain length, sequence, and stereochemistry in order to construct a new polymer. Unlike conventional polymers, protein polymers are not necessarily one monomer repeated multiple times; they can be comprised of a discrete set of monomers repeated multiple times. So the team experimented with arranging alpha helices (obtained from the cartilage oligomeric matrix protein, COMP) and beta spirals (obtained from elastin) to determine whether the orientation of the blocks and the number of blocks influence the self-assembly and structure of the constructed proteins.
         The methods for this part of the study included cloning a protein using restriction enzymes, purifying the proteins, incubating the proteins with Vitamin D, and mutating the amino acids into alanine to note the mutation’s effects on the secondary and tertiary structure of the enzymes. By using dynamic light scattering of the elastin monomer, the team compared the characteristics of proteins formed from Elastin-COMP, COMP-Elastin, and Elastin-COMP-Elastin blocks and found that the orientation of the fusion made a difference in the enzymes’ behaviors.
The team is currently collaborating with the NYU Dental School to explore ways that the synthesized proteins could be used in tissues. Since they bind to Vitamin D, it is possible that they could be used to facilitate bone generation.
         Prior to Dr. Montclare’s presentation, Christine Constantinople, a PhD candidate at Columbia University, announced that she is working with graduate students who are available to host a number of workshops in schools. Topics include discussions on bioethical problems in research; a “reverse science fair” in which students “judge” learning stations put on by university undergraduates, graduate students, post-docs, and faculty; and brain awareness days on which human brains, animal brains, and a spinal cord are brought to elementary and high schools for a hands-on exploration of the nervous system. For more information, email Ms. Constantinople at <cmc2229@columbia.edu>.
 

Submitted by: Jean Delfiner, Co-chair
High School Teachers Topical Group

207 Lincoln Place
Eastchester, NY 10709-2005
914-961-8882/FAX 914-771-6669
JADelfiner@verizon.net
Date:    November 29, 2008