Archived

CSULB Colloquium- Nov 6

PHYSICS COLLOQUIUM
California State University Long Beach
Monday, November 6, 2017
11:15 am in PH1-223
(Refreshments served at 10:45am in HSCl-224)
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Force Sensing by Bacteria
Prof. Albert Siryaporn
Department of Physics and Astronomy
Department of Biology & Biochemistry
University of California Irvine

My lab explores how bacteria detect and respond to mechanical forces. During the course of an infection, bacteria encounter a variety of mechanical forces such as adhesive forces during contact with the host cells that they infect and shear stresses in fluidic environments. We have developed a biophysical approach to explore how bacteria interpret mechanical cues to detect the presence of host cells and to guide the expansion of large bacterial populations within host organisms. In particular, we found that the pathogen Pseudomonas aeruginosa detects the presence of hosts using a mechano-sensitive mechanism, akin to a bacterial sense of touch. This response activates virulence and consequently P. aeruginosa, unlike other pathogens, relies on mechanical input rather than exclusively on chemical signals for infection. This model provides a long-sought explanation for understanding how P. aeruginosa can infect a broad range of hosts including humans, animals and plants. The ubiquity and diversity of mechanical forces in all aspects of a bacterium’s life have far-reaching consequences that we are just beginning to comprehend.

Adjunct Physics Instructors Wanted

The Division of Mathematics and Sciences of Rio Hondo College has an immediate need for an adjunct instructor for its instructional labs in the spring semester. One lab is for General Physics II: MW 12:50-2:15 pm; the other for Physics for Scientists and Engineers I: MW 4:00-5:25 pm. Classes begin on Jan. 29.

Apply at https://riohondo.peopleadmin.com/postings/773.

Lunch reservations for fall meeting are due

Please complete the online form immediately if you are interested in reserving a box lunch (Rubios burrito and sides) for this Saturday’s SCAAPT meeting at Saddleback College. Lunch orders are due November 1 by noon.

See the meeting page for complete details on the schedule, parking, and order of magnitude question.

CSULB Colloquium- Oct 30

PHYSICS COLLOQUIUM
California State University Long Beach
Monday, October 30, 2017
11:15 am in PH1-223
(Refreshments served at 10:45am in HSCl-224)
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What is a skyrmion?
Dr. Héctor Ochoa
Department of Physics and Astronomy
University of California, Los Angeles

This question was a recurrent in-joke with my wife to make fun of people who uses ostentatious jargon when talking about Physics. Paradoxically (or not), I have become the object of my diffusion past jokes with the passage of time. As an act of contrition, I will try to answer this question in  simple terms, providing  also a historical background. In short: a skyrmion is an emergent particle associated with a whirling configuration of a vectorial order parameter. It was originally proposed by Tony Skyrme as a candidate for hadronic matter back in the early 60’s. However, skyrmions have been more profusely discussed in different contexts of Condensed Matter Physics. I will pay special attention to the case of magnetism, where skyrmions appear as textures of the spin-density field stabilized by relativistic interactions in some materials that receive the name of chiral magnets. I will describe the intriguing dynamics of these objects, which mimics the motion of charged particles in the presence of a strong magnetic field, and how this can be manipulated by non-equilibrium torques induced, for example, by electronic currents. In the last part of the talk, I will discuss quantum-size effects and connections with the quantum Hall effect.

Fall Meeting schedule is posted

The complete schedule for the upcoming SCAAPT Fall Meeting is now posted on the SCAAPT website. There is still time to reserve a box lunch.
SCAAPT Fall Meeting
November 4, 2018
Saddleback College
Complete schedule of contributed and invited talks (plus information about parking).
We look forward to seeing old and new friends at this meeting.

 

CSULB Colloquium- Oct 23

PHYSICS COLLOQUIUM
California State University Long Beach
Monday, October 23, 2017
11:15 am in PH1-223
(Refreshments served at 10:45am in HSCl-224)
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Majorana Materializes
Prof. Jason Alicea
California Institute of Technology

In 1937 Ettore Majorana introduced the concept of what are now fittingly called Majorana fermions – fermionic particles that are their own antiparticles. Nowadays an active search for condensed-matter analogues of these elusive objects is well underway, motivated by both the prospect of revealing new facets of quantum mechanics and longer-term quantum computing applications. This talk will survey recent advances in this pursuit. In particular, I will describe strategies for “engineering” Majorana platforms from simple building blocks, preliminary experimental successes, and future milestones that reveal foundational aspects of Majorana physics directly relevant for quantum computation.

Lunch reservations for Fall Meeting

If you would like to reserve a box lunch for the November 4 meeting, please complete the online form by October 30. Lunches will be a burrito from Rubios, plus drinks.

(The complete meeting schedule will be posted soon!)

Exploring Your Universe at UCLA

Exploring Your Universe is UCLA’s annual science festival, educating and inspiring over 7,000 visitors each year! Launch bottle rockets, make comets, do chemistry and physics experiments, touch brains, see fossils, and much more! Exploring Your Universe will also offer planetarium shows, science talks, and telescope viewings! is free and appropriate for all ages!
SUNDAY, November 5, 2017
12:00 p.m. to 5:00 p.m.
Night-time activities until 8:00 p.m.
UCLA Court of Sciences
Please join us for this family-friendly day of science exploration at UCLA. Visit the event website for a full schedule and directions. Admission is free. All ages are welcome.

Parking is available for $12 in Lot 2 and Lot 8.

CSULB Colloquium- Oct 16

PHYSICS COLLOQUIUM
California State University Long Beach

Monday, October 16, 2017
11:15 am in PH1-223

(Refreshments served at 10:45am in HSCl-224)
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Scanning Tunneling Microscopy of Graphene:  Hydrogen Desorption and Nitrogen Doping
Prof. Li Gao
California State University, Northridge

Scanning tunneling microscopy (STM) can provide atomic-scale insights into the properties of materials. Functionalization of graphene with adsorbates or dopants is important toward its practical applications. In this talk, I will discuss our recent STM studies of hydrogen-passivated graphene and nitrogen-doped graphene. First, we investigated electron-stimulated desorption of hydrogen from the graphene/SiC(0001) surface at room temperature. Two different desorption processes were observed. We also found that the curvature of graphene dramatically affects hydrogen desorption. Second, we investigated the synthesis of nitrogen doped graphene on metals from a nitrogen-containing sole precursor azafullerene. Three different metal surfaces have been used, including Ru(0001), Cu(111), and Ir(111). Our results indicate that azafullerene is an effective sole precursor for the controlled synthesis of nitrogen-doped graphene, and the growth substrate strongly influences the synthesis process and doping properties.

Deadline for Fall Meeting Submissions is Oct. 13

Please consider submitting an abstract for a presentation or Show & Tell at our upcoming meeting (November 4 at Saddleback College). You need to complete the online submission form by October 13, for your presentation to be considered.