Quantum Dynamics in Non-equilibrium Strongly Correlated Environments

We consider a quantum point contact between two Luttinger liquids coupled to a mechanical system (oscillator). For non-vanishing bias, we find an effective oscillator temperature that depends on the Luttinger parameter. A generalized fluctuation-dissipation relation connects the decoherence and dissipation of the oscillator to the current-voltage characteristics of the device. Via a spectral representation, this result is generalized to arbitrary leads in a weak tunneling regime.Comment: 4 pages, 1 figur

Structure and photoluminescence of helium-intercalated fullerite C₆₀

Intercalation of C₆₀ single crystals with helium was studied by powder x-ray diffractometry. It was established that the intercalation is a two-stage process, octahedral cavities are filled first and then tetrahedral ones, the chemical pressure being negative during both stages. For the first time low-temperature (5 K) photoluminescence spectra of helium-intercalated fullerite C₆₀ were studied. The presence of helium in lattice voids was shown to reduce that part of the luminescent intensity which is due to the emission of covalently bound pairs of C₆₀ molecules, the socalled "deep traps" with the 0-0 transition energy close to 1.69 eV. The mechanism of the effect of the intercalation with helium on the pair formation in fullerite C₆₀ is discussed

Asymptotic Analysis of Coagulation–Fragmentation Equations of Carbon Nanotube Clusters

The possibility of the existence of single-wall carbon nanotubes (SWNTs) in organic solvents in the form of clusters is discussed. A theory is developed based on abundletmodel for clusters describing the distribution function of clusters by size. The phenomena have a unified explanation in the framework of the bundlet model of a cluster, in accordance with which the free energy of an SWNT involved in a cluster is combined from two components: a volume one, proportional to the number of moleculesnin a cluster, and a surface one, proportional ton1/2. During the latter stage of the fusion process, the dynamics were governed mainly by the displacement of the volume of liquid around the fusion site between the fused clusters. The same order of magnitude for the average cluster-fusion velocity is deduced if the fusion process starts with several fusion sites. Based on a simple kinetic model and starting from the initial state of pure monomers, micellization of rod-like aggregates at high critical micelle concentration occurs in three separated stages. A convenient relation is obtained for <n> at transient stage. At equilibrium, another relation determines dimensionless binding energy α. A relation with surface dilatational viscosity is obtained

Experimental tests on fracture strength of nanotubes

A new experimental and post-analysis procedure to perform tensile-loading experiments on nanofibers, e.g., carbon nanotubes (CNTs) or nanowires, is presented. The procedure has been applied to multiwalled carbon nanotubes (MWCNTs). At this time, we consider the corresponding results on fracture strength (strain and Young's modulus) as preliminary, but these preliminary results strongly suggest the presence of defects in the tested nanotubes. Assuming defects like clusters of adjacent vacancies (e.g., atomistic blunt cracks) we tried to rationalize the preliminary experimental data by applying Quantized Fracture Mechanics (QFM). So far the experimental results are not sufficient to validate this approach, and the next step of this research is to obtain much more data, using our new methodology, to further test QFM, including possibly introducing atomistic defects of well-known size and shape in a controlled way

Comprehensive Evaluation of Algal Biofuel Production: Experimental and Target Results

Worldwide, algal biofuel research and development efforts have focused on increasing the competitiveness of algal biofuels by increasing the energy and financial return on investments, reducing water intensity and resource requirements, and increasing algal productivity. In this study, analyses are presented in each of these areas—costs, resource needs, and productivity—for two cases: (1) an Experimental Case, using mostly measured data for a lab-scale system, and (2) a theorized Highly Productive Case that represents an optimized commercial-scale production system, albeit one that relies on full-price water, nutrients, and carbon dioxide. For both cases, the analysis described herein concludes that the energy and financial return on investments are less than 1, the water intensity is greater than that for conventional fuels, and the amounts of required resources at a meaningful scale of production amount to significant fractions of current consumption (e.g., nitrogen). The analysis and presentation of results highlight critical areas for advancement and innovation that must occur for sustainable and profitable algal biofuel production can occur at a scale that yields significant petroleum displacement. To this end, targets for energy consumption, production cost, water consumption, and nutrient consumption are presented that would promote sustainable algal biofuel production. Furthermore, this work demonstrates a procedure and method by which subsequent advances in technology and biotechnology can be framed to track progress.Center for Electromechanic

Patch clamp technique: Review of the current state of the art and potential contributions from nanoengineering

The patch clamp technique permits high-resolution recording of the ionic currents flowing through a cell&apos;s plasma membrane. In different configurations, this technique has allowed experimenters to record and manipulate the currents that flow either through single ion channels or those that flow across the whole plasma membrane. Unfortunately, the conventional patch clamp method is laborious, requiring the careful fabrication of electrodes, skillful manipulation of the patch pipette towards a cell, and the clever design of electronics and apparatus to allow low-noise recordings. Advances in microfabrication offer promising technologies for high-throughput patch clamp recordings, particularly suitable for drug screening. This paper provides a review of the advances that have been made in the patch clamp technique over the years and considers where application of nanotechnology might provide significant contributions in the future

Exploration of the active center structure of nitrogen-doped graphene-based catalysts for oxygen reduction reaction

10.1039/c2ee21802jEnergy and Environmental Science577936-794