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Monday Morning Memo

Here's a brief synopsis of what's going on this week in regards to Physics... and beyond.

Posted by Jill Ackerman at 8:35AM   |  Add a comment

Tuesday, November 27, 2012

Seminar Series: Please join us for a talk with Biophysicist Rebecca Metzler of Colgate University

Barnacles are animals consisting of a soft creature inside a hard outer shell, similar to a lobster or crab, except the outer shell of a barnacle is securely stuck to a surface with an extraordinary cement that sticks to a wide range of surfaces and hardens underwater. The barnacle outer shell and cement are biominerals, composite materials consisting of a mixture of proteins, which consist of amino acids, and minerals, which in barnacles are largely calcium carbonate. The remarkable ability of the barnacle’s cement to harden underwater, unlike man-made adhesives, has been the focus of barnacle research in the past five years. We approached this question by exploring the composition and structure of barnacle cement through the use of the synchrotron based techniques x-ray absorption near edge structure (XANES) spectroscopy and x-ray photoemission electron microscopy (X-PEEM).

Examination of both fully mineralized and fully demineralized barnacle cement made it possible for us to determine that barnacle cement consists of a thick proteinaceous matrix intermixed with calcium carbonate crystals. Carbon K-edge XANES spectra extracted from the demineralized and mineralized cement show drastic differences between the two samples, indicating the formation of bonds between the organic and mineral components of barnacle cement in vivo. Structurally, the calcium carbonate crystals are randomly oriented and consist largely of calcite, as revealed by oxygen K-edge polarization-dependent imaging contrast (PIC) mapping and calcium L-edge XANES spectroscopy. Surprisingly, in addition to the calcite crystals found within the barnacle cement, hints of amorphous calcium carbonate, the transient pre-cursor to more stable forms of calcium carbonate, were also detected. These preliminary results provide an exciting and novel view of barnacle cement that may provide important information into its material properties.

12:10 CNS 204

Pizza and refreshments provided for $1. Please bring your own cup. Reuse, Reduce Recycle.

Friday, November 30, 2012

You are invited to join the Ithaca College Department of Physics for a Public Viewing of the night sky at the Clinton B. Ford Observatory.

8:00 PM - 10:00 PM Friday November 30, 2012

To attend a Public Night:
Just show up at the vehicle 'turn around' in front of the entrances of Smiddy Hall and CHS (F lot side).  A shuttle van will make regular runs to convey people up to the observatory and back down. Please note that there is NO parking available up at the observatory and that the access road is NOT lighted. For your own safety, please do not walk up.

Bad Weather Plan:
The "go/no-go" decision for any public night will be made at 3:30 pm on the scheduled date. Our web page and the recorded message at the observatory will be updated shortly thereafter to reflect the decision for that evening. So if you check our website or call the observatory at 607-274-3012 after 4:00 pm you will get the final decision for that evening.

Visit Our Website
/briotta/observatory/index.html


Posted by Jill Ackerman at 2:12PM   |  Add a comment

Tuesday, November 6, at 12:10 PM in CNS 204

Physics Fall Seminar Series:

Join us as Britt Scharringhausen gives a talk on: Probing the Vertical Structure of Saturn's F Ring through Ring-Plane Crossings

Saturn's narrow, dusty F ring lies just outside the main rings.  It is difficult to observe from Earth, except during a ring-plane crossing, when the rings are viewed edge-on. The Earth passes through Saturn's ring plane only about every 15 years. In a ring-plane crossing observed by Hubble Space Telescope in August 1995, an asymmetry in brightness between the east and west sides of the rings was observed.  We have shown that the inclination of the F ring relative to the main rings caused the asymmetry, because the F ring unevenly obscures the east and west side of the main rings. This discovery afforded an opportunity to measure the vertical thickness of the F ring, which we found to be 13 +/- 7 km.  Since 2004, the F ring has been observed extensively by the Cassini spacecraft.  The same techniques used to analyze the Earth ring-plane crossing can be applied to observations made during of crossings of the ring-plane by the Cassini spacecraft.  More rapid sampling allows us to probe the vertical structure of the F ring in even greater detail, and high-resolution images reveal details that are impossible to observe from Earth. 

Pizza and Refreshments will be available for $1. Please bring your own cup. Remember to Recycle, Reuse, Reduce.


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