46 research outputs found
Production operation of small petroleum enterprises in Tomsk region
Implementing resource-innovative strategy to develop Russian fuel-and-energy sector implies the promotion of small oil production enterprises developing fields with the reserves of less than 5 mln. tons. However, the efficiency of such enterprises, investigated on the example of Tomsk region (considering the indexes of oil extraction, growth of reserves, amount of capital expenditures and geological surveys), signifies the presence of definite tendencies. Consequently, management decisions concerning economic, organizational, financial and fiscal character should be taken in order to eliminate detrimental factors
High Temperature Treatment of Diamond Particles Toward Enhancement of Their Quantum Properties
Fluorescence of the negatively charged nitrogen-vacancy (NV-) center of diamond is sensitive to external electromagnetic fields, lattice strain, and temperature due to the unique triplet configuration of its spin states. Their use in particulate diamond allows for the possibility of localized sensing and magnetic-contrast-based differential imaging in complex environments with high fluorescent background. However, current methods of NV(-)production in diamond particles are accompanied by the formation of a large number of parasitic defects and lattice distortions resulting in deterioration of the NV(-)performance. Therefore, there are significant efforts to improve the quantum properties of diamond particles to advance the field. Recently it was shown that rapid thermal annealing (RTA) at temperatures much exceeding the standard temperatures used for NV(-)production can efficiently eliminate parasitic paramagnetic impurities and, as a result, by an order of magnitude improve the degree of hyperpolarization of(13)C via polarization transfer from optically polarized NV(-)centers in micron-sized particles. Here, we demonstrate that RTA also improves the maximum achievable magnetic modulation of NV(-)fluorescence in micron-sized diamond by about 4x over conventionally produced diamond particles endowed with NV-. This advancement can continue to bridge the pathway toward developing nano-sized diamond with improved qualities for quantum sensing and imaging
Fabrication Process Independent And Robust Aggregation Of Detonation Nanodiamonds In Aqueous Media
In the past detonation nanodiamonds (DNDs), sized 3–5 nm, have been praised for their colloidal stability in aqueous media, thereby attracting vast interest in a wide range of applications including nanomedicine. More recent studies have challenged the consensus that DNDs are monodispersed after their fabrication process, with their aggregate formation dynamics poorly understood. Here we reveal that DNDs in aqueous solution, regardless of their post-synthesis de-agglomeration and purification methods, exhibit hierarchical aggregation structures consisting of chain-like and cluster aggregate morphologies. With a novel characterization approach combining machine learning with direct cryo-transmission electron microscopy and with X-ray scattering and vibrational spectroscopy, we show that their aggregate morphologies of chain and cluster ratios and the corresponding size and fractal dimension distributions vary with the post-synthesis treatment methods. In particular DNDs with positive ζ-potential form to a hierarchical structure that assembles aggregates into large networks. DNDs purified with the gas phase annealing and oxidation tend to have more chain-like aggregates. Our findings provide important contribution in understanding the DND interparticle interactions to control the size, polydispersity and aggregation of DNDs for their desired applications
Carbon-Coated Nickel Nanoparticles: Effect on the Magnetic and Electric Properties of Composite Materials
Nickel nanoparticles coated with few layers of carbon have been embedded into the polydimethylsiloxane (PDMS) matrix in concentrations up to 11 vol %. Dielectric and magnetic properties of composite materials have been studied in wide frequency (20 Hz–1 MHz) and temperature (130–430 K) ranges. It was demonstrated that the temperature behavior of dielectric properties is determined by glass transitions in the PDSM matrix below 200 K and the Maxwell–Wagner relaxation above room temperature. The possibility of using fabricated composites on the basis of the PDMS matrix for producing a wide range of passive electromagnetic components, such as frequency-selective filters, wide-band detectors/sensors of a bolometric type, and even electromagnetic “black holes” is also discussed
Ultrasonic and dielectric studies of polymer PDMS composites with ZnO and onion-like carbons nanoinclusions
The ultrasonic and dielectric temperature investigations were performed in polydi-methylsiloxane (PDMS) with zinc oxide (ZnO) and onion-like carbon (OLC) nanocomposites. In the glass transition region, the ultrasonic velocity dispersion and large ultrasonic attenuation maxima were observed. The positions of ultrasonic attenuation peaks were slightly shifted to higher temperatures after doping PDMS with OLC and ZnO nanoparticles. The ultrasonic relaxation was compared to that of dielectric and such behaviour was described by Vogel-Fulcher law. The upshift of the glass transition temperature with addition of nanoparticles was confirmed by both methods. The additional increase of ultrasonic attenuation in composites doped with OLC and ZnO was observed at room temperature and such behaviour we attributed to ultrasound–nanofiller interaction in polymer matrix
NATO Advanced Research Workshop on Synthesis, Properties and Applications of Ultrananocrystalline Diamond
Ultrananocrystalline diamond (UNCD) is one of the important members of the triad of nanostructured carbons, which includes fullerenes and nanotubes. UNCD with characteristic sizes of primary particles less than 10 nm occurs in two forms: as a dispersed powder made by detonation techniques and as a chemical vapor deposited film. This book for the first time combines results of research pursued by the two communities of scientists, which up to now, have been working rather independently and largely unaware of the vast synergistic relationships existing between them. It is particularly noteworthy that much of the Russian work on disperse UNCD is available here in English for the first time. The outstanding experts in the two fields are represented in this volume discussing the basic theoretical concepts underlying the synthesis and characterization of these nanomaterials and describing progress that has been made in several areas of applications such as nanocomposites, selective adsorbents, colloidal suspensions, microabrasives, lubricants, quantum dots, cold-cathodes for UNCD particles and MEMS, biosensors, electrochemical, and nerve prostheses, high temperature, highly rectifying diodes, FET’s, thermoelectrics for UNCD films. This Proceedings volume will be of interest to a wide audience of scientists and engineers and serve as an introduction to an important and rapidly evolving field of nanoscience and nanomaterials; as a text for a special topics graduate course; or as a starting point for those interested in the development of new approaches to problems that have hitherto defied solution for lack of suitable materials