Fundamentals of crude oil and natural gas processing

This training manual includes term project methodical guide on the course "Fundamentals of crude oil and natural gas processing" in English. The main purpose of the training manual is to provide students the theoretical and methodological assistance at performance the term project on the course "Fundamentals of crude oil and natural gas processing". The manual contains the initial data and reference material needed to perform the calculations. The manual is intended for the students of speciality 6.050304 "Oil and gas production" in English

Accretion dynamics in the classical T Tauri star V2129 Oph

We analyze the photometric and spectroscopic variability of the classical T Tauri star V2129 Oph over several rotational cycles to test the dynamical predictions of magnetospheric accretion models. The photometric variability and the radial velocity variations in the photospheric lines can be explained by rotational modulation due to cold spots, while the radial velocity variations of the He I (5876 \AA) line and the veiling variability are due to hot spot rotational modulation. The hot and cold spots are located at high latitudes and about the same phase, but the hot spot is expected to sit at the chromospheric level, while the cold spot is at the photospheric level. Using the dipole+octupole magnetic-field configuration previously proposed in the literature for the system, we compute 3D MHD magnetospheric simulations of the star-disk system. We use the simulation's density, velocity and scaled temperature structures as input to a radiative transfer code, from which we calculate theoretical line profiles at all rotational phases. The theoretical profiles tend to be narrower than the observed ones, but the qualitative behavior and the observed rotational modulation of the H\alpha and H\beta emission lines are well reproduced by the theoretical profiles. The spectroscopic and photometric variability observed in V2129 Oph support the general predictions of complex magnetospheric accretion models with non-axisymmetric, multipolar fields.Comment: Accepted by Astronomy and Astrophysic

Fast Shocks From Magnetic Reconnection Outflows

Magnetic reconnection is commonly perceived to drive flow and particle acceleration in flares of solar, stellar, and astrophysical disk coronae but the relative roles of different acceleration mecha- nisms in a given reconnection environment are not well understood. We show via direct numerical simulations that reconnection outflows produce weak fast shocks, when conditions for fast recon- nection are met and the outflows encounter an obstacle. The associated compression ratios lead to a Fermi acceleration particle spectrum that is significantly steeper than the strong fast shocks commonly studied, but consistent with the demands of solar flares. While this is not the only acceleration mechanism operating in a reconnection environment, it is plausibly a ubiquitous one

Reconnecting Magnetic Flux Tubes as a Source of In Situ Acceleration in Extragalactic Radio Sources

Many extended extragalactic radio sources require a local {\it in situ\/} acceleration mechanism for electrons, in part because the synchrotron lifetimes are shorter than the bulk travel time across the emitting regions. If the magnetic field in these sources is localized in flux tubes, reconnection may occur between regions of plasma \be (ratio of particle to magnetic pressure) $<<1$, even though $\beta$ averaged over the plasma volume may be \gsim 1. Reconnection in low $\beta$ regions is most favorable to acceleration from reconnection shocks. The reconnection X-point regions may provide the injection electrons for their subsequent non-thermal shock acceleration to distributions reasonably consistent with observed spectra. Flux tube reconnection might therefore be able to provide $in\ situ$ acceleration required by large scale jets and lobes.Comment: 14 pages, plain TeX, accepted to Ap.J.Let

Conductivity, weak ferromagnetism and charge instability in α−MnS\alpha-MnS single crystal

The temperature dependence of resistivity, magnetization and electron-spin resonance of the $\alpha- MnS$ single crystal were measured in temperature range of $5 K < T < 550 K$. Magnetization hysteresis in applied magnetic field up to 0.7 T at $T=5 K, 77 K, 300 K$, irreversible temperature behavior of magnetization and resistivity were found . The obtained data were explained in terms of degenerate tight binding model using random phase approximation. The contribution of holes in $t_{2g}$ and $e_g$ bands of manganese ions to the conductivity, optical absorbtion spectra and charge instability in $\alpha -MnS$ were studied. Charge susceptibility maxima resulted from the competition of the on-site Coulomb interaction between the holes in different orbitals and small hybridization of sub-bands were calculated at $T=160 K, 250 K, 475 K$.Comment: 6 pages, 12 figure

The Use of Contact Heat Generators of the New Generation for Heat Production

We substantiated the need for searching for, and realization of, fundamentally new approaches, using more efficient physical, heat-mass-exchanging and aerodynamic processes, which will make it possible to improve energy effectiveness and ecological cleanliness of heat generation in the systems for individual and decentralized heat supply.For the heat supply to large cities and industrial regions, we examined the advantages of using highly efficient contact heat-generators of different types, which include compactness due to low metal consumption and, as a result, attractive price.It is proposed to use a heat-generator of contact type of the new generation, with the aid of which it was possible to solve a set of problems on the qualitative combustion of fuel and effective heat exchange of gases with the heated water. The use of tubular technology for the combustion of gas is its special feature. Due to it, quality heat exchanging characteristics are provided.In view of further studies, we presented the relevance of creating heat-generators with the use of highly effective hydrogen technologies, which will make it possible to devise the new energy paradigm of heat supply for residential areas and industrial zones through the possibility of accumulation of electrical energy and accumulation of hydrogen

Warps, bending and density waves excited by rotating magnetized stars: results of global 3D MHD simulations

We report results of the first global three-dimensional magnetohydrodynamic simulations of the waves excited in an accretion disc by a rotating star with a dipole magnetic field misaligned from the star's rotation axis (which is aligned with the disc axis). The main results are the following: (1) If the magnetosphere of the star corotates approximately with the inner disc, then we observe a strong one-armed bending wave (a warp). This warp corotates with the star and has a maximum amplitude between corotation radius and the radius of the vertical resonance. The disc's center of mass can deviate from the equatorial plane up to the distance of z_w\approx 0.1 r. However, the effective height of the warp can be larger, h_w \approx 0.3 r due to the finite thickness of the disc. Stars with a range of misalignment angles excite warps. However, the amplitude of the warps is larger for misalignment angles between 15 and 60 degrees. (2) If the magnetosphere rotates slower, than the inner disc, then a bending wave is excited at the disc-magnetosphere boundary, but does not form a large-scale warp. Instead, high-frequency oscillations become strong at the inner region of the disc. These are (a) trapped density waves which form inside the radius where the disc angular velocity has a maximum, and (b) inner bending waves which appear in the case of accretion through magnetic Raleigh-Taylor instability. These two types of waves are connected with the inner disc and their frequencies will vary with accretion rate. Bending oscillations at lower frequencies are also excited including global oscillations of the disc. In cases where the simulation region is small, slowly-precessing warp forms. Simulations are applicable to young stars, cataclysmic variables, and accreting millisecond pulsars.Comment: 26 pages, 25 figure