24 research outputs found
Modulation of activity of the suprachiasmatic nucleus neurons by orexigenic and anorexigenic regulators
Π Π°ΡΡΠ΅Ρ Π³ΠΈΠ΄ΡΠΎΠ΄ΠΈΠ½Π°ΠΌΠΈΠΊΠΈ ΠΏΠΎΡΠΎΠΊΠ° Π² ΡΠ»Π΅ΠΊΡΡΠΎΡΠΈΠΊΠ»ΠΎΠ½Π΅
To analyze the elektrocyclone flow hydrodynamic computer calculation using the finite element method (FEM) is applied. The geometry of the model corresponds to the laboratoryΒ Β elektrocyclone. k-Ξ΅-turbulence model is used for the computation. The system of equations is solved by SIMPLE algorithm. The calculation results give a pattern of the flow velocity distribution and flow lines in different sections. There is conclusion based on the results about elektrocyclone flow hydrodynamic.ΠΠ»Ρ Π°Π½Π°Π»ΠΈΠ·Π° Π³ΠΈΠ΄ΡΠΎΠ΄ΠΈΠ½Π°ΠΌΠΈΠΊΠΈ ΠΏΠΎΡΠΎΠΊΠ° Π² ΡΠ»Π΅ΠΊΡΡΠΎΡΠΈΠΊΠ»ΠΎΠ½Π΅ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ ΠΊΠΎΠΌΠΏΡΡΡΠ΅ΡΠ½ΡΠΉ ΡΠ°ΡΡΠ΅Ρ Ρ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ ΠΌΠ΅ΡΠΎΠ΄Π° ΠΊΠΎΠ½Π΅ΡΠ½ΡΡ
ΡΠ»Π΅ΠΌΠ΅Π½ΡΠΎΠ² (ΠΠΠ). ΠΠ΅ΠΎΠΌΠ΅ΡΡΠΈΡ ΠΌΠΎΠ΄Π΅Π»ΠΈ ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²ΡΠ΅Ρ Π»Π°Π±ΠΎΡΠ°ΡΠΎΡΠ½ΠΎΠΌΡ ΡΠ»Π΅ΠΊΡΡΠΎΡΠΈΠΊΠ»ΠΎΠ½Ρ. ΠΠ»Ρ ΡΠ°ΡΡΠ΅ΡΠΎΠ² ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½Π° k-Ξ΅-ΠΌΠΎΠ΄Π΅Π»Ρ ΡΡΡΠ±ΡΠ»Π΅Π½ΡΠ½ΠΎΡΡΠΈ. Π‘ΠΈΡΡΠ΅ΠΌΠ° ΡΡΠ°Π²Π½Π΅Π½ΠΈΠΉ ΡΠ΅ΡΠ°Π΅ΡΡΡ Ρ ΠΏΠΎΠΌΠΎΡΡΡ Π°Π»Π³ΠΎΡΠΈΡΠΌΠ° SIMPLE. Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ ΡΠ°ΡΡΠ΅ΡΠ° Π΄Π°ΡΡ ΠΊΠ°ΡΡΠΈΠ½Ρ ΡΠ°ΡΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ ΡΠΊΠΎΡΠΎΡΡΠ΅ΠΉ ΠΏΠΎΡΠΎΠΊΠ° ΠΈ Π»ΠΈΠ½ΠΈΠΉ ΡΠΎΠΊΠ° Π² ΡΠ°Π·Π»ΠΈΡΠ½ΡΡ
ΡΠ΅ΡΠ΅Π½ΠΈΡΡ
. ΠΠ° ΠΎΡΠ½ΠΎΠ²Π°Π½ΠΈΠΈ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠΎΠ² Π΄Π΅Π»Π°Π΅ΡΡΡ Π²ΡΠ²ΠΎΠ΄ ΠΎ Π³ΠΈΠ΄ΡΠΎΠ΄ΠΈΠ½Π°ΠΌΠΈΠΊΠ΅ ΡΠ»Π΅ΠΊΡΡΠΎΡΠΈΠΊΠ»ΠΎΠ½Π°. ΠΡΡΠ²Π»Π΅Π½ ΡΠ°ΠΊΡ, ΡΡΠΎ Π² Π±ΡΠ½ΠΊΠ΅ΡΠ΅ ΡΠ»Π΅ΠΊΡΡΠΎΡΠΈΠΊΠ»ΠΎΠ½Π° ΠΎΡΡΡΡΡΡΠ²ΡΠ΅Ρ Π²ΠΈΡ
ΡΠ΅Π²ΠΎΠ΅ Π΄Π²ΠΈΠΆΠ΅Π½ΠΈΠ΅, ΡΠ°ΠΊΠΆΠ΅ Π½Π΅Ρ ΡΠ°Π·Π²ΠΈΡΠΎΠ³ΠΎ ΡΠ΅ΡΠ΅Π½ΠΈΡ Π² ΠΎΠ±Π»Π°ΡΡΠΈ ΡΡΠ΅Π½ΠΎΠΊ, Π° Π½ΠΈΠΆΠ΅ Π²ΡΡ
Π»ΠΎΠΏΠ½ΠΎΠ³ΠΎ ΠΎΡΠ²Π΅ΡΡΡΠΈΡ ΡΠΊΠΎΡΠΎΡΡΡ ΠΏΠΎΡΠΎΠΊΠ° Π±Π»ΠΈΠ·ΠΊΠ° ΠΊ 0. ΠΡΠΎ Π±Π»Π°Π³ΠΎΠΏΡΠΈΡΡΠ½ΠΎ ΡΠΊΠ°Π·ΡΠ²Π°Π΅ΡΡΡ Π½Π° ΡΡΡΠ΅ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ ΠΎΡΠΈΡΡΠΊΠΈ, Ρ. ΠΊ. Π²ΡΡ
ΠΎΠ΄ΡΡΠΈΠΉ ΡΠΈΡΡΡΠΉ Π³Π°Π· Π½Π΅ ΡΠ²Π»Π΅ΠΊΠ°Π΅Ρ Ρ ΡΠΎΠ±ΠΎΠΉ ΠΎΡΠ΅Π²ΡΠΈΠ΅ ΡΠ°ΡΡΠΈΡΡ. ΠΡΠ²ΠΎΠ΄Ρ: 1) Π³ΠΈΠ΄ΡΠΎΠ΄ΠΈΠ½Π°ΠΌΠΈΠΊΠ° ΡΠ»Π΅ΠΊΡΡΠΎΡΠΈΠΊΠ»ΠΎΠ½Π° ΠΌΠΎΠΆΠ΅Ρ Π±ΡΡΡ ΠΎΠΏΠΈΡΠ°Π½Π° Ρ ΠΏΠΎΠΌΠΎΡΡΡ ΠΌΠ°ΡΠ΅ΠΌΠ°ΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΌΠΎΠ΄Π΅Π»ΠΈ ΠΈ ΡΠ°ΡΡΡΠΈΡΠ°Π½Π° Ρ ΠΏΠΎΠΌΠΎΡΡΡ ΠΠΠ; 2) ΠΏΠΎΡΠΎΠΊ Π² ΡΠ»Π΅ΠΊΡΡΠΎΡΠΈΠΊΠ»ΠΎΠ½Π΅, ΠΊΠ°ΠΊ ΠΈ ΠΎΠΆΠΈΠ΄Π°Π»ΠΎΡΡ, ΠΈΠΌΠ΅Π΅Ρ Π·Π°ΠΊΡΡΡΠ΅Π½Π½ΡΡ ΡΡΡΡΠΊΡΡΡΡ, ΡΠ³ΠΎΠ» Π·Π°ΠΊΡΡΡΠΊΠΈ Π·Π°Π²ΠΈΡΠΈΡ ΠΎΡ Π΄Π»ΠΈΠ½Ρ Π°ΠΊΡΠΈΠ²Π½ΠΎΠΉ Π·ΠΎΠ½Ρ; 3) ΠΊΠΎΠ½ΡΡΡΡΠΊΡΠΈΡ Π±ΡΠ½ΠΊΠ΅ΡΠ° ΠΎΠ±Π΅ΡΠΏΠ΅ΡΠΈΠ²Π°Π΅Ρ Π²ΡΡ
ΠΎΠ΄ ΠΎΡΠΈΡΠ΅Π½Π½ΠΎΠ³ΠΎ Π³Π°Π·Π° Π±Π΅Π· Π²ΠΎΠ²Π»Π΅ΡΠ΅Π½ΠΈΡ Π² Π½Π΅Π³ΠΎ ΡΠ»ΠΎΠ²Π»Π΅Π½Π½ΡΡ
ΡΠ°ΡΡΠΈΡ
Thermal Properties of Graphene, Carbon Nanotubes and Nanostructured Carbon Materials
Recent years witnessed a rapid growth of interest of scientific and
engineering communities to thermal properties of materials. Carbon allotropes
and derivatives occupy a unique place in terms of their ability to conduct
heat. The room-temperature thermal conductivity of carbon materials span an
extraordinary large range - of over five orders of magnitude - from the lowest
in amorphous carbons to the highest in graphene and carbon nanotubes. I review
thermal and thermoelectric properties of carbon materials focusing on recent
results for graphene, carbon nanotubes and nanostructured carbon materials with
different degrees of disorder. A special attention is given to the unusual size
dependence of heat conduction in two-dimensional crystals and, specifically, in
graphene. I also describe prospects of applications of graphene and carbon
materials for thermal management of electronics.Comment: Review Paper; 37 manuscript pages; 4 figures and 2 boxe
Isotope Effect in Thermal Conductivity of Polycrystalline CVD-Diamond: Experiment and Theory
We measured the thermal conductivity ΞΊ(T) of polycrystalline diamond with natural (natC) and isotopically enriched (12C content up to 99.96 at.%) compositions over a broad temperature T range, from 5 to 410 K. The high quality polycrystalline diamond wafers were produced by microwave plasma chemical vapor deposition in CH4-H2 mixtures. The thermal conductivity of 12C diamond along the wafer, as precisely determined using a steady-state longitudinal heat flow method, exceeds much that of the natC sample at T>60 K. The enriched sample demonstrates the value of ΞΊ(298K)=25.1Β±0.5 W cmβ1 Kβ1 that is higher than the ever reported conductivity of natural and synthetic single crystalline diamonds with natural isotopic composition. A phenomenological theoretical model based on the full version of Callaway theory of thermal conductivity is developed which provides a good approximation of the experimental data. The role of different resistive scattering processes, including due to minor isotope 13C atoms, defects, and grain boundaries, is estimated from the data analysis. The model predicts about a 37% increase of thermal conductivity for impurity and dislocation free polycrystalline chemical vapor deposition (CVD)-diamond with the 12C-enriched isotopic composition at room temperature