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.

Intramolecular vibrational relaxation in 1,4 dioxane

Abstract: Intramolecular vibrational energy transfer in isolated gas phase molecules of dioxane has been studied by spectrally resolving the IR laser induced fluorescence from C–H stretch fundamentals, combination bands, and overtones in the region from 2800 to 3000 cm−1. By comparing the experimentally observed relative energy content of the IR active modes with that calculated from a statistical model it is concluded that substantial randomization of the energy initially deposited in the zeroth order optically excited state occurs. This statistical distribution differs from a thermal distribution due to fluctuations in the local state density. The energy content distribution is best described by the model if coupling over a range of 4 cm−1 is assumed. Dilution factors for the various C–H stretch modes were observed which vary from 0.018 to 0.13. These values are dependent on the rotational state excited. Collisional time dependent spectra of several relaxed modes are presented. The experiments are performed by ex...

Graphene-based Materials: Graphene and Graphene Oxide: Synthesis, Properties, and Applications (Adv. Mater. 35/2010)

Abstract: There is intense interest in graphene in fields such as physics, chemistry, and materials science, among others. Interest in graphene's exceptional physical properties, chemical tunability, and potential for applications has generated thousands of publications and an accelerating pace of research, making review of such research timely. Here is an overview of the synthesis, properties, and applications of graphene and related materials (primarily, graphite oxide and its colloidal suspensions and materials made from them), from a materials science perspective.

Probing carbon isotope effects on the Raman spectra of graphene with different C-13 concentrations

Abstract: Bruno R. Carvalho,1,* Yufeng Hao,2 Ariete Righi,1 Joaquin F. Rodriguez-Nieva,3 Luigi Colombo,4 Rodney S. Ruoff,2,5,6 Marcos A. Pimenta,1 and Cristiano Fantini1,† 1Departamento de Fisica, Universidade Federal de Minas Gerais, 30123-970 Belo Horizonte, MG, Brazil 2Department of Mechanical Engineering and the Materials Science and Engineering Program, The University of Texas at Austin, 1 University Station C2200, Austin, Texas 78712-0292, USA 3Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA 4Texas Instruments Incorporated, 13121 TI Boulevard, MS-365 Dallas, Texas 75243, USA 5Center for Multidimensional Carbon Materials, Institute for Basic Science (IBS), Ulsan 689-798, Republic of Korea 6Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea (Received 16 June 2015; published 8 September 2015)

Chemical Vapor Deposition Growth of Graphene and Related Materials

Abstract: Research on atomic layers including graphene, hexagonal boron nitride (hBN), transition metal dichalcogenides (TMDCs) and their heterostructures has attracted a great deal of attention. Chemical vapor deposition (CVD) can provide large-area structure-defined high-quality atomic layer samples, which have considerably contributed to the recent advancement of atomic-layer research. In this article, we focus on the CVD growth of various atomic layers and review recent progresses including (1) the CVD growth of graphene using methane and ethanol as carbon sources, (2) the CVD growth of hBN using borazine and ammonia borane, (3) the CVD growth of various TMDCs using single and multi-furnace methods, and (4) CVD growth of vertical and lateral heterostructures such as graphene/hBN, MoS2/graphite, WS2/hBN and MoS2/WS2.

Using coin cells for ultracapacitor electrode material testing

Abstract: The effects of compressive force and the addition of conductive fillers on ultracapacitor electrode performance measurements were studied. We have shown that the force exerted by typical battery coin cell components is inadequate, resulting in erroneous measurements of electrode performance. We further demonstrated that with modest modifications, coin cell measurements can equal those of specialized test fixtures and of packaged cells.

The rise of graphene

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.

Fast parallel algorithms for short-range molecular dynamics

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.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

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。

Measurement of the Elastic Properties and Intrinsic Strength of Monolayer Graphene

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.