Thursday, February 27, 2014

Correlation dynamics and enhanced signals for the identification of serial biomolecules and DNA bases

Hot off the press! Recent publication by Dr. Haraldsen on correlation dynamics for the enhancement of electronic signals to identify serial biomolecules and DNA bases. Below is the abstract.

Nanopore-based sequencing has demonstrated a significant potential for the development of fast, accurate, and cost-efficient fingerprinting techniques for next generation molecular detection and sequencing. We propose a specific multilayered graphene-based nanopore device architecture for the recognition of single biomolecules. Molecular detection and analysis can be accomplished through the detection of transverse currents as the molecule or DNA base translocates through the nanopore. To increase the overall signal-to-noise ratio and the accuracy, we implement a new 'multi-point cross-correlation' technique for identification of DNA bases or other molecules on the single molecular level. We demonstrate that the cross-correlations between each nanopore will greatly enhance the transverse current signal for each molecule. We implement first-principles transport calculations for DNA bases surveyed across a multilayered graphene nanopore system to illustrate the advantages of the proposed geometry. A time-series analysis of the cross-correlation functions illustrates the potential of this method for enhancing the signal-to-noise ratio. This work constitutes a significant step forward in facilitating fingerprinting of single biomolecules using solid state technology.

The full paper can be found at

Tuesday, February 25, 2014

Research Corporation for Science Advancement Award goes to Dr. Adriana Banu!

Dr. Adriana Banu is one of the 2014 recipients of the Single-Investigator Cottrell College Science Award from the Research Corporation for Science Advancement to support her nuclear astrophysics research project entitled "Determination of Key Astrophysical Photonuclear Reaction Cross Section Towards Understanding the Origin of p-Nuclei". Several undergraduates from the Physics and Astronomy Department at JMU are heavily involved in the project!!!

Below is the abstract of the project:

The proposed research aims to contribute to enhancing the current state of fundamental knowledge on a forefront topic in nuclear astrophysics - the nucleosynthesis beyond iron of the rarest stable isotopes (the origin of the p-nuclei). More specifically, it is focused on constraining the origin of the p-nuclei through nuclear physics by investigating, as a first step, the cross section measurement of the 94Mo(g,n)93Mo reaction, a key photonuclear reaction for understanding the astrophysical p-process (the mechanism responsible for the origin of the p-nuclei). The experimentally unknown reaction cross section is proposed to be studied close to and above the neutron threshold with quasi-monochromatic photon beams at Duke University's High Intensity Gamma-ray Source (HIgS) facility, which is currently the most intense accelerator-driven g-ray source in the world. Total cross section measurements of the 94Mo(g,n)93Mo reaction with an energy threshold at 9.7 MeV will be performed at beam energies starting from above the neutron thresholds up to around 13 MeV in steps of 100 - 150 keV. A highly enriched target sample of the 94Mo isotope is required. Neutrons from the (g,n) reaction will be detected using an assembly of 4pi 3He proportional counters developed at Los Alamos National Laboratories and presently available at HIgS-Triangle University Nuclear Laboratory (TUNL). 

Sunday, February 16, 2014

CCTV Discussion Panel on the challenges for electric cars with Dr. Haraldsen

On Sunday February 16th 2014, Dr. Haraldsen (@JMU Physics) appeared on CCTV's World Insight to discuss the challenges that electric cars have to face. The major issues are cost, range, environmental savings. In the segment, it is discussed that, while the cost for some electric vehicles are becomes more reasonable for the average consumer, the range for the cheaper electric cars does not even come close to challenging conventional gasoline powered cars. Therefore, it is critical for research and development of more advanced battery technologies.

As for environmental savings, electric cars are highly dependent on the methods being used to produce electricity. Given that China, India, and the US are still very dependent on fossil fuels (coal, natural gas, and petroleum), the assertion that electric cars are zero emission is a fallacy. By charging your electric vehicle using coal and natural gas you are still producing massive amounts of carbon dioxide (CO2).

For example, the Tesla Model S ($70k - $100k) has the ability to travel around 255 miles on a single charge due to its large 85 kWh battery (initial charge). If you charge the Model S with electricity from coal (2.08 lbs. CO2/kWh), then you produce ~176 lbs. of CO2 and particulates. If you look at an average gasoline power vehicle with 30 mpg, then you use about 8.5 gallons of gasoline in a 255 mile trip. Given that gasoline, on average, produces 22 lbs. CO2/gallon, this gasoline powered vehicle will have released ~187 lbs of CO2 and particulates, which is about the same as the electric vehicle. If you have a Toyota Prius (~50 mpg), then that drops to 112 lbs. CO2 released. Furthermore, charging with natural gas (1.22 lbs. CO2/kWh) will help reduce the CO2 to 103 lbs., which puts it a slight bit better than the Prius. Therefore, if a country like China or the United States is serious about reducing carbon emissions, then there needs to be a planned move toward alternative, non-carbon producing power sources.

The main advantage of an electric car is that they are dependent on the source of electricity, and as the electric grid move toward more efficient and clearer energy sources, electric cars will become clearer as well.

Below are pictures from the discussion panel on CCTV News. Here is the video link for the discussion on electric cars.

Thursday, February 13, 2014

Collaboration paper accepted to Journal of Physical Chemistry Letters!

Our first collaboration paper between Dr. Costel Constantin's group and Dr. Patrick Hopkins' group (from UVa) has been accepted into the Journal of Physical Chemistry Letters (see reference below). In this paper, we measured the thermal conductivity of solid, water insoluble thin films of bovine serum albumin and myoglobin proteins.  The measurements preformed in the temperature range 77 - 296 K indicate an anharmonic coupling of vibrations that is contributing to thermal conductivity.  Our own undergraduate, Chester Szwejkowski, is also a co-author on this work and he will join (as a graduate student!) Patrick's lab this Fall of 2014.  We wish him GOOD LUCK!

B. M. Foley, C. S. Gorham, J. C. Duda, R. Cheaito, C. J. Szwejkowski, C. Constanin, B. Kaehr, P. E. Hopkins. "Protein Thermal Conductivity Measured in the Solid State Demonstrates Anharmonic Interactions of Vibrations in a Fractal Structure". accepted in JPCL 2014.