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Rodney S. Ruoff

Bio: Rodney S. Ruoff is an academic researcher from Ulsan National Institute of Science and Technology. The author has contributed to research in topics: Graphene & Graphene oxide paper. The author has an hindex of 164, co-authored 666 publications receiving 194902 citations. Previous affiliations of Rodney S. Ruoff include Texas State University & North Carolina State University.


Papers
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Journal Article
TL;DR: Carvalho et al. as mentioned in this paper investigated carbon isotope effects on the Raman spectra of graphene with different 13 C isotope concentrations and using different laser excitation energies, and showed that isotope substitution does not alter the electron and phonon dispersions near the K point of the graphene Brillouin zone.
Abstract: Citation Carvalho, Bruno R., et al. \"Probing carbon isotope effects on the Raman spectra of graphene with different [superscript 13]C concentrations. Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. A resonance Raman study of graphene samples with different 13 C isotopic concentrations and using different laser excitation energies is presented. The main Raman peaks (D, G, G * , and 2D) of graphene were measured and the dependence of their frequencies on the isotope atomic mass follows a simple harmonic oscillator relation. The G * and 2D double-resonance peak positions were measured as a function of the laser energy, and we observed that the slopes of the laser energy dependence are the same independently of isotope concentration. This result shows that isotopic substitution does not alter the electron and phonon dispersions near the K point of the graphene Brillouin zone. From the linewidth of G and 2D Raman peaks, we have also obtained a dependence of the phonon lifetime on the 13 C isotope concentration.

1 citations

Proceedings ArticleDOI
08 Jun 2014
TL;DR: In this paper, the authors demonstrate that graphene can strongly modulate the scattered light from Fano-resonant plasmonic metasurfaces, achieving a modulation depth of 1000% at around 7mm as the carrier concentration changes.
Abstract: We experimentally demonstrate that graphene can strongly modulate the scattered light from Fano-resonant plasmonic metasurfaces. The Modulation depth of 1000% is achieved at around 7mm as the graphene carrier concentration changes

1 citations

Proceedings ArticleDOI
09 Jun 2013
TL;DR: In this paper, the authors demonstrate theoretically and experimentally that electrically gated single-layer graphene can be used to inductively tune the infrared optical response of Fano-resonant meta-surfaces.
Abstract: We demonstrate theoretically and experimentally that electrically gated single-layer graphene can be used to inductively tune the infrared optical response of Fano-resonant meta-surfaces. The induced spectral shifts are used to extract graphene's electronic properties.

1 citations

Journal ArticleDOI
TL;DR: In this article , a study of the kinetics of dissolution of (100) and (110) single-crystal diamond plates in thin films of nickel (Ni) and cobalt (Co).
Abstract: We report a study of the kinetics of dissolution of (100) and (110) single-crystal diamond plates (“D(100)” and “D(110)”) in thin films of nickel (Ni) and cobalt (Co). This dissolution occurs at the metal–D(100) or metal–D(110) interface and was studied in the presence and also in the absence of water vapor at temperatures near 1000 °C. The single-crystal D(100) dissolves in Ni, and also in Co, in the temperature range 900–1050 °C. The dissolution is too slow to measure below 900 °C. In an argon (Ar) atmosphere (under an Ar(g) flow at 1000 sccm and 1 atm pressure, with no water vapor present in the reaction chamber) and at any temperature in the range 900–1050 °C, the metal film is rapidly saturated with dissolved carbon (C), thin graphite films form on the free metal surface and at the metal–D interface during heating at or above 650 °C, and the dissolution of the diamond then stops. For addition of water vapor, its partial pressure was controlled by using a water bubbler immersed in a constant temperature bath and Ar(g) was used as the carrier gas. We discovered two different regimes (I and II) for the kinetics of dissolution of D(100) and D(110), in which the rate-determining step was the removal of carbon atoms on the open metal surface (regime I, lower partial pressure of water vapor) or dissolution of diamond at the metal–diamond interface (regime II, higher partial pressure of water vapor) that yielded different Arrhenius parameters. Time-of-flight-secondary ion mass spectrometry depth profiles show the concentration gradient of C from a certain depth into the metal film surface down to the M–D(100) interface, and residual gas analyzer measurements show that the gas products formed in the presence of water vapor on the metal surface are CO and H2. It was found that the rate of dissolution of diamond in Co was higher than that in Ni for both D(100) and D(110) and for both regimes I and II, and possible reasons are suggested. We also found that D(111) could not be dissolved at the Ni/D(111) and Co/D(111) interface in the presence of water vapor (over the same range of sample temperatures). The reaction paths for dissolution of C at the M–D(100) or M–D(110) interface and for removal of C from the free surfaces of Ni and Co were assessed through density functional theory modeling at 1273 K.

1 citations

Book ChapterDOI
01 Jan 2003
Abstract: Carbon nanotubes, including both multi-walled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNTs), are fascinating low dimensional systems for studies in electronics and mechanics Their applications in nano-electronic or nano-mechanical systems have been suggested For example, ‘on-nanotube’ devices such as diode, bucky shuttle, or multiple terminal logic circuits have been treated by theory for electronic systems1, 2, 3, 4, and the use of nanotubes as nano-pistons, nanosyringes, and rotors for mechanical systems have also been modeled5, 6, 7

1 citations


Cited by
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Journal ArticleDOI
TL;DR: Owing to its unusual electronic spectrum, graphene has led to the emergence of a new paradigm of 'relativistic' condensed-matter physics, where quantum relativistic phenomena can now be mimicked and tested in table-top experiments.
Abstract: Graphene is a rapidly rising star on the horizon of materials science and condensed-matter physics. This strictly two-dimensional material exhibits exceptionally high crystal and electronic quality, and, despite its short history, has already revealed a cornucopia of new physics and potential applications, which are briefly discussed here. Whereas one can be certain of the realness of applications only when commercial products appear, graphene no longer requires any further proof of its importance in terms of fundamental physics. Owing to its unusual electronic spectrum, graphene has led to the emergence of a new paradigm of 'relativistic' condensed-matter physics, where quantum relativistic phenomena, some of which are unobservable in high-energy physics, can now be mimicked and tested in table-top experiments. More generally, graphene represents a conceptually new class of materials that are only one atom thick, and, on this basis, offers new inroads into low-dimensional physics that has never ceased to surprise and continues to provide a fertile ground for applications.

35,293 citations

01 May 1993
TL;DR: Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems.
Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

29,323 citations

28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal ArticleDOI
Changgu Lee1, Xiaoding Wei1, Jeffrey W. Kysar1, James Hone1, James Hone2 
18 Jul 2008-Science
TL;DR: Graphene is established as the strongest material ever measured, and atomically perfect nanoscale materials can be mechanically tested to deformations well beyond the linear regime.
Abstract: We measured the elastic properties and intrinsic breaking strength of free-standing monolayer graphene membranes by nanoindentation in an atomic force microscope. The force-displacement behavior is interpreted within a framework of nonlinear elastic stress-strain response, and yields second- and third-order elastic stiffnesses of 340 newtons per meter (N m(-1)) and -690 Nm(-1), respectively. The breaking strength is 42 N m(-1) and represents the intrinsic strength of a defect-free sheet. These quantities correspond to a Young's modulus of E = 1.0 terapascals, third-order elastic stiffness of D = -2.0 terapascals, and intrinsic strength of sigma(int) = 130 gigapascals for bulk graphite. These experiments establish graphene as the strongest material ever measured, and show that atomically perfect nanoscale materials can be mechanically tested to deformations well beyond the linear regime.

18,008 citations