Sensitive Detection of Industrial Pollutants Using Modified Electrochemical Platforms.

Water pollution is nowadays a global problem and the effective detection of pollutants is of fundamental importance. Herein, a facile, efficient, robust, and rapid (response time < 2 min) method for the determination of important quinone-based industrial pollutants such as hydroquinone and benzoquinone is reported. The recognition method is based on the use of screen-printed electrodes as sensing platforms, enhanced with carbon-based nanomaterials.

Terahertz Absorber with Graphene Enhanced Polymer Hemispheres Array.

We propose an original technique for the fabrication of terahertz (THz) metasurfaces comprising a 3D printed regular array of polymer hemispheres covered with a thin conductive layer. We demonstrate that the deposition of a thin metal layer onto polymer hemispheres suppresses the THz reflectivity to almost zero, while the frequency range of such a suppression can be considerably broadened by enhancing the structure with graphene. Scaling up of the proposed technique makes it possible to tailor the electromagnetic responses of metasurfaces and allows for the fabrication of various components of THz photonics.

Laser Patterning of Aligned Carbon Nanotubes Arrays: Morphology, Surface Structure, and Interaction with Terahertz Radiation.

The patterning of arrays of aligned multi-walled carbon nanotubes (MWCNTs) allows creating metastructures for terahertz (THz) applications. Here, the strips and columns from MWCNTs vertically grown on silicon substrates are prepared using CO laser treatment. The tops of the patterned arrays are flat when the laser power is between 15 and 22 W, and craters appear there with increasing power.

Electromagnetic and optical responses of a composite material comprising individual single-walled carbon-nanotubes with a polymer coating.

The composites and thin films comprising individual single-walled carbon nanotubes with a polymer coating (p-CNTs) have been prepared and their electromagnetic responses have been studied in a wide range from low-frequency (25-10 Hz) up to the infrared region. In spite of the high volume fraction of the nanotubes (up to 3.3%), the polymer coating prevents direct p-CNT contacts and the formation of the percolation network in those composites, so that p-CNTs interact only via the electromagnetic coupling.

Electrical Permittivity and Conductivity of a Graphene Nanoplatelet Contact in the Microwave Range.

This paper investigates the electrical properties in the microwave range of a contact made by graphene nanoplatelets. The final goal is that of estimating the range of values for the equivalent electrical complex permittivity of a contact obtained by integrating low-cost graphene in the form of nanoplatelets (GNPs) into a high-frequency electrical circuit. To this end, a microstrip-like circuit is designed and realized, where the graphene nanoplatelets are self-assembled into a gap between two copper electrodes.

Carbon nanotube sponges as tunable materials for electromagnetic applications.

The microwave conductivity and permittivity of both single-walled and multi-walled carbon nanotube (SWCNT and MWCNT) sponges were measured while compressing the samples. Compression leads to a huge variation of the absorptance, reflectance, and transmittance of the samples. The dependence of the microwave conductivity on the sponge density follows a power-law relation with exponents 1.

Coherent anti-Stokes Raman scattering as an effective tool for visualization of single-wall carbon nanotubes.

Strong vibrational coherent anti-Stokes Raman scattering (CARS) signal was observed in single-wall carbon nanotubes (SWCNTs) having three different average diameters (about 0.8 nm, 1.1 nm and 1.

Flexible transparent graphene/polymer multilayers for efficient electromagnetic field absorption.

Thanks to its high electrical conductivity, a graphene plane presents a good shielding efficiency against GHz electromagnetic radiations. Several graphene planes separated by thin polymer spacers add their conductivities arithmetically, because each of them conserves the intrinsic properties of isolated graphene. Maximum absorption of radiations for frequency around 30 GHz is achieved with six separated graphene planes, which is the optimum number.

Multilayered graphene in K(a)-band: nanoscale coating for aerospace applications.

We report on the experimental study of electromagnetic (EM) properties of multilayered graphene in K(a)-band synthesized by catalytic chemical vapor deposition (CVD) process in between nanometrically thin Cu catalyst film and dielectric (SiO2) substrate. The quality of the produced multilayered graphene samples was monitored by Raman spectroscopy. The thickness of graphene films was controlled by atomic force microscopy (AFM) and was found to be a few nanometers (up to 5 nm).

Epoxy resin/carbon black composites below the percolation threshold.

A set of epoxy resin composites filled with 0.25-2.0 wt.

Microwave absorption properties of pyrolytic carbon nanofilm.

We analyzed the electromagnetic (EM) shielding effectiveness in the Ka band (26 to 37 GHz) of highly amorphous nanometrically thin pyrolytic carbon (PyC) films with lateral dimensions of 7.2 × 3.4 mm2, which consists of randomly oriented and intertwined graphene flakes with a typical size of a few nanometers.

Soft cutting of single-wall carbon nanotubes by low temperature ultrasonication in a mixture of sulfuric and nitric acids.

To decrease single-wall carbon nanotube (SWCNT) lengths to a value of 100-200 nm, aggressive cutting methods, accompanied by a high loss of starting material, are frequently used. We propose a cutting approach based on low temperature intensive ultrasonication in a mixture of sulfuric and nitric acids. The method is nondestructive with a yield close to 100%.

The effect of sample holder geometry on electromagnetic heating of nanoparticle and NaCl solutions at 13.56 MHz.

Electromagnetic absorption and subsequent heating of nanoparticle solutions and simple NaCl ionic solutions is examined for biomedical applications in the radiofrequency range at 13.56 MHz. It is shown via both theory and experiment that for in vitro measurements the shape of the solution container plays a major role in absorption and heating.

Phylogenetic diversity of T4-like bacteriophages in Lake Baikal, East Siberia.

Among the tailed phages, the myoviruses, those with contractile tails, are widespread and diverse. An important component of the Myoviridae family is the genus 'T4-like viruses'. The present study was aimed at elucidating the molecular diversity of T4-type bacteriophages in Lake Baikal by partial sequencing of g23 genes of T4-type bacteriophages.

Hyperthermic effect of multi-walled carbon nanotubes stimulated with near infrared irradiation for anticancer therapy: in vitro studies.

Unlabelled: It is proposed to use the novel paradigm of treating cancer with hyperthermic therapy using multi-walled carbon nanotubes (MWCNT) stimulated with near infrared (NIR) irradiation.

Aim: To establish the capacity of MWCNT stimulated with NIR irradiation to destroy Erlich ascitic carcinoma (EAC) cells.

Materials And Methods: EAC cells suspension was irradiated with NIR heating lamp with a wavelength of 0.

Matter coupling to strong electromagnetic fields in two-level quantum systems with broken inversion symmetry.

We demonstrate theoretically the parametric oscillator behavior of a two-level quantum system with broken inversion symmetry exposed to a strong electromagnetic field. A multitude of resonance frequencies and additional harmonics in the scattered light spectrum as well as an altered Rabi frequency are predicted to be inherent to such systems. In particular, dipole radiation at the Rabi frequency appears to be possible.

[Microbial community of the water column of the Selenga River-Lake Baikal biogeochemical barrier].

The microbial communities of the estuarine zone and the mixing zone of river and lake waters in the Selenga River estuary were studied using the fluorescence in situ hybridization (FISH) method. The microorganisms belonging to the phylogenetic group Gammaproteobacteria were found to predominate in the river estuary, constituting up to 17% of the total bacterial community. Among cultivable microorganisms, organotrophic bacteria were predominant (2040 CFU/ml) in this zone, which results in high rates of microbial production (6.

Dipole polarizability of onion-like carbons and electromagnetic properties of their composites.

Onion-like carbons (OLC) obtained by thermal transformation of nanodiamonds are agglomerates of multi-shell fullerenes, often covered by an external graphitic mantle. For the present work, elemental OLC units were constructed on the computer by coalescence of several two-layer fullerenes, in a structure similar to carbon peapods with a corrugated external wall. The electrical polarizability of such pod-of-peas fullerenes has been computed by a classical monopole-dipole atomistic theory.

Spontaneous decay of excited atomic states near a carbon nanotube.

The spontaneous decay process of an excited atom placed inside or outside a carbon nanotube is analyzed. Calculations have been performed for various achiral nanotubes. The effect of the nanotube surface is shown to increase the atomic spontaneous decay rate by up to 6 orders of magnitude compared with that of the same atom in vacuum.

[The evaluation of the late results of destruction of the atrioventricular junction in patients with drug-resistant atrial fibrillation].

Atrial fibrillation is a commonly seen form of disordered cardiac rhythm. Catheter-radio frequency ablation of the atrioventricular junction was found out to be an effective approach to control heart rate in continued drug-refractory cardiac fibrillation permitting the quality of the patients' life to be improved. The best results are achievable in patients presenting with chronic cardiac fibrillation.