Thermal Gases Research Articles

Hydrocarbons from a volcanic area. Oil seeps in the Uzon caldera, Kamchatka

The isotope and hydrocarbon compositions of oil seeps in the caldera of Uzon Volcano were investigated. An experiment was conducted to simulate the thermal hydrolysis of biota in the hot springs of the caldera, which is considered as a source of carbon for the oil seeps. The same methods were applied to investigate petroleum condensate and thermal gases (CH4 and CO2) from a well in the Bogachevka field adjacent to the Uzon caldera. The measured carbon isotope composition of oils from the Uzon caldera (δ13C of −31.24 and −31.47‰) is typical of oils derived from biological materials of mostly bacterial origin. The low content of tricyclic terpanes, which is a qualitative oil maturity parameter, indicates that the oil maturity of the Uzon seeps is low. In the gas samples, the δ13C of CO2 ranges from −6.5 to −0.18‰ averaging approximately −2.8‰. The δ13C of methane is from −30.13 to −19.03‰ averaging approximately −24.0‰. A difference was detected between the isotopic fractionation characteristics of naphtides from the Uzon caldera and products of the thermal hydrolysis of biota. In turn, the isotopic fractionation characteristic of thermally hydrolyzed biota appeared to be similar to the proportion of the isotopic compositions of the respective fractions of Bogachevka oil. The identical isotopic diagrams of the Bogachevka oil and the hydrothermally transformed biota confirm the biogenic nature of the Bogachevka oil. Hydrocarbons from the Uzon caldera (Kamchatka) are mainly products of the hydrothermal transformation of the biomass of microorganisms and plant remains in the zone of thermal water circulation.

Development of equipment and technological schemes to reduce emissions of sugar factory

The state of utilization of steam and gas emissions in the sugar industry is analyzed. The significant emissions at low stimulation work to reduce them are stated. One reason for this situation is the lack of cost-effective recycling of heat and chemical potentials.One of the ways to reduce emissions is to intensify the work of saturation and sulfitation devices. Data of research of saturation device with the first stage of phase contact spray and subsequent bubble are presented. The implementation of saturation process in this unit allows increasing the utilization rate of CO2 by 20 ... 25 % and improving the quality of the juice.For deeper utilization of steam and gas emissions it is proposed technological scheme, which involves pretreating beet chips by exhaust sulfur burned and carbonated gases. Such treatment would allow on the one hand minimizing thermal pollution emissions and corrosive gases and, on the other hand utilizing the energy potential of the preparation of raw materials for extraction. The equipment for this treatment is available commercially or can be produced by the sugar factory itself.

Coherent spin-mixing dynamics in thermalRb87spin-1 and spin-2 gases

We study the non-equilibrium coherent spin mixing dynamics in ferromagnetic spin-1 and antiferromagnetic spin-2 thermal gases of ultracold $^{87}$Rb atoms. Long lasting spin population oscillations with magnetic field dependent resonances are observed in both cases. Our observations are well reproduced by Boltzmann equations of the Wigner distribution function. Compared to the equation of motion of spinor Bose-Einstein condensates, the only difference here is a factor of two increase in the spin-dependent interaction, which is confirmed directly in the spin-2 case by measuring the relation between the oscillation amplitude and the sample's density.

Geochemistry and origin of shallow gas in the Baise Basin, southern China

Abstract Many small and medium-sized Paleogene pull-apart basins in southern China contain an abundance of biogenic gas shows. Such shallow gas with biogenic characteristics has been thoroughly investigated only in Baise Basin. Hence, the research results from Baise Basin could serve as a model for the origin and characteristics of shallow gases in similar basins and areas in Southern China. There are ten gas fields with a total of proven reserves of 20 billion cubic meters discovered in Baise Basin. Three gas fields are located on the western and southern flank of the basin, and they are gas caps to heavy oil pools from depths between 600 m and 850 m. These accumulations contain dry biogenic gases, with C1/C1-5 exceeding 0.99, light δ13C1 (–76 to −54‰), and heavy δD1 (−218‰). Trace heavy gaseous hydrocarbons are strongly biodegraded (iC4/nC4>3). The other seven gas fields are located in the northern fault zone and the central Nakun uplift of the basin at depths between 300 m and 700 m. Gases are mainly unassociated and condensed gases. The condensed gases are depleted in 13C (δ13C1: −67 to −53.7‰, δ13C2: −52.3 to −36.1‰, δ13C3: −43.3 to −33.4‰), but wet with C1/C2+3 mostly less than 20, suggesting a mainly thermal origin at low maturity. The unassociated gases are dominated by methane, with C1/C2+3 ratio above 100, variable N2 (0 to 5.4%), and traces of CO2. The δ13C value of methane in the unassociated gases is between −76 to −60‰, and δD1 values from −248 to −213.7‰. These gases also contain isotopically light ethane with δ13C2 values of −64.5 to −42‰, which we infer to have originated from deeper horizons as a result of migration or diffusion from low-maturity thermal gases with light stable carbon isotopic compositions (C1/C2+3 <20, δ13C2 from −60‰ to −58‰). A similar thermal origin is inferred for the other heavy gaseous hydrocarbons. Formation water with the shallow gases of this basin is mainly NaHCO3-type with low TDS ranging from 1000 to 4500 ppm. The (HCO3+CO3)/Cl ratios range from 1.5 to 100, indicating a relative open hydrodynamic condition and the possible intrusion of meteoric water. These data indicate that early biogenic gas generated syndepositionally was probably not preserved, and that the current biogenic gas accumulation formed mainly as a result post-depositional of crude oil biodegradation in the western basin and coal biodegradation in the northern fault zone. Shallow gases in Baise Basin are mainly secondary biogenic gases, with an admixture of low maturity thermogenic gases from deeper horizons.

Thermal Ground State and Nonthermal Probes

The Euclidean formulation of SU(2) Yang-Mills thermodynamics admits periodic, (anti)self-dual solutions to the fundamental, classical equation of motion which possess one unit of topological charge: (anti)calorons. A spatial coarse graining over the central region in a pair of such localised field configurations with trivial holonomy generates an inert adjoint scalar fieldϕ, effectively describing the pure quantum part of the thermal ground state in the induced quantum field theory. Here we show for the limit of zero holonomy how (anti)calorons associate a temperature independent electric permittivity and magnetic permeability to the thermal ground state ofSU2CMB, the Yang-Mills theory conjectured to underlie the fundamental description of thermal photon gases.

Microscopic description of neutron emission rates in compound nuclei

The neutron emission rates in thermal excited nuclei are conventionally described by statistical models with a phenomenological level density parameter that depends on excitation energies, deformations and mass regions. In the microscopic view of hot nuclei, the neutron emission rates can be determined by the external neutron gas densities without any free parameters. Therefore the microscopic description of thermal neutron emissions is desirable that can impact several understandings such as survival probabilities of superheavy compound nuclei and neutron emissivity in reactors. To describe the neutron emission rates microscopically, the external thermal neutron gases are self-consistently obtained based on the Finite-Temperature Hartree-Fock-Bogoliubov (FT-HFB) approach. The results are compared with the statistical model to explore the connections between the FT-HFB approach and the statistical model. The Skyrme FT-HFB equation is solved by HFB-AX in deformed coordinate spaces. Based on the FT-HFB approach, the thermal properties and external neutron gas are properly described with the self-consistent gas substraction procedure. Then neutron emission rates can be obtained based on the densities of external neutron gases. The thermal statistical properties of $^{238}$U and $^{258}$U are studied in detail in terms of excitation energies. The thermal neutron emission rates in $^{238, 258}$U and superheavy compound nuclei $_{112}^{278}$Cn and $_{114}^{292}$Fl are calculated, which agree well with the statistical model by adopting an excitation-energy-dependent level density parameter. The coordinate-space FT-HFB approach can provide reliable microscopic descriptions of neutron emission rates in hot nuclei, as well as microscopic constraints on the excitation energy dependence of level density parameters for statistical models.

PRECIPITATION OF ENERGETIC NEUTRAL ATOMS AND INDUCED NON-THERMAL ESCAPE FLUXES FROM THE MARTIAN ATMOSPHERE

The precipitation of energetic neutral atoms, produced through charge exchange collisions between solar wind ions and thermal atmospheric gases, is investigated for the Martian atmosphere. Connections between parameters of precipitating fast ions and resulting escape fluxes, altitude-dependent energy distributions of fast atoms and their coefficients of reflection from the Mars atmosphere, are established using accurate cross sections in Monte Carlo simulations. Distributions of secondary hot atoms and molecules, induced by precipitating particles, have been obtained and applied for computations of the non-thermal escape fluxes. A new collisional database on accurate energy-angular dependent cross sections, required for description of the energy-momentum transfer in collisions of precipitating particles and production of non-thermal atmospheric atoms and molecules, is reported with analytic fitting equations. 3D Monte Carlo simulations with accurate energy-angular dependent cross sections have been carried out to track large ensembles of energetic atoms in a time-dependent manner as they propagate into the Martian atmosphere and transfer their energy to the ambient atoms and molecules. Results of the Monte Carlo simulations on the energy-deposition altitude profiles, reflection coefficients, and time-dependent atmospheric heating, obtained for the isotropic hard sphere and anisotropic quantum cross sections, are compared. Atmospheric heating rates, thermalization depths, altitude profiles of production rates, energy distributions of secondary hot atoms and molecules, and induced escape fluxes have been determined.

Flue-Gas Desulfurization Technology and its Equipment

The peak of power consumption will be brought by the rapid development of the industry. Thermal power is still the main component of electric energy at present. More and more attention has been paid on the atmospheric pollution caused by the thermal power plant in our country. The sulfur dioxide (SO2), one of the thermal power plant flue gases, is dangerous to the environment and human. Effective SO2 control technology can not only reduce the environmental pollution but also the sulfur can be recovered in order to conserve resources.

Simulation of Solar Organic Rankine Cycle System Using Turbocharger with Cycle Tempo and Environmentally Friendly Fluid

Organic Rankine cycle (ORC) is a modified rankine cycle with working fluids, of organic material (Refrigerant). Refrigerant pentane has low boiling point, therefore ORC can be used in power plant which uses low temperature resources, such as solar thermal exhausted gases and geothermal wells. Organic Rankine Cycle (ORC) is used to convert heat energy into mechanical energy or electricity generated by a low temperature of the hot sun. The working fluid used is HCR12, HCR22, HCR134a and Pentane. Simulations performed with an organic Rankine cycle temperature and pressure with cycle tempo program. By programming the simulation cycle tempo and got the result on the maximum power a turbine to the conditions of the working fluid Pentane to the input turbine T = 700C and pressure = 2 bar can generate 2.07 kW. Turbocharger is one of the alternatives in the energy conversion of the energy of motion into electrical energy. Turbocharger rotation will be used to turn a generator and converts the energy of motion into electrical energy.

Diffusion effects in gradient echo memory

We study the effects of diffusion on a $\Lambda$-gradient echo memory, which is a coherent optical quantum memory using thermal gases. The efficiency of this memory is high for short storage time, but decreases exponentially due to decoherence as the storage time is increased. We study the effects of both longitudinal and transverse diffusion in this memory system, and give both analytical and numerical results that are in good agreement. Our results show that diffusion has a significant effect on the efficiency. Further, we suggest ways to reduce these effects to improve storage efficiency.

Fischer–Tropsch Synthesis Conducted in Volcanic Reservoir Stone, An Important Factor Caused a Reversed Pattern of Carbon Isotopic for Natural Gases Developed in Deep Layers, Songliao Basin North East China

Two types of experiments of source rocks pyrolysis with volcanic reservoir rock and without one were conducted under hydrothermal condition and at 200 °C in gold tube system. The experiments result shows that there is a higher concentration of hydrocarbon gases generated in the experiment with rhyolite of reservoir stone and water than that with only water. Moreover, the hydrocarbon gases generated by experiments with rhyolite show a full reserved pattern of carbon isotope. This indicated that the FST reaction could happened between source rocks and volcanic reservoir rock at relatively low temperature. The numerical calculation for the carbon isotope of the gases from mixture between the gases from our FTS experiments and the typical organic hydrocarbon gases from deep layers of Songliao basin show that the contamination of a little FTS gas (&lt;5%, v/v) could cause the carbon isotope composition of thermal gases great variation. So, Fischer–Tropsch synthesis conducted in volcanic reservoir stone is an un-negligible factor caused the reversed pattern of carbon isotopic for natural gases developed in deep layers, Songliao Basin. This also indicated that the natural gases in deep layers of the basin are organic origin chiefly.

New experimental results of combined SO2 and NO removal from simulated gas stream by NaClO as low-cost absorbent

The experiments were performed in a magnetic stirrer reactor to study the simultaneous absorption of NO and SO2 using NaClO solution from simulated gas stream. The effects of various operating parameters viz., absorbent concentration, reaction temperature, initial SO2 and NO concentration and initial pH of NaClO solution on simultaneous removal of SO2 and NO were investigated in regard to coal-fired thermal power plant stack gases. The maximum removal efficiencies of SO2 and NO were observed as 100% and 92%, respectively at 313K, initial NaClO solution pH 5.8 and 0.01M NaClO concentration. The important rate governing steps with appropriate reaction mechanisms for simultaneous removal of SO2 and NO using NaClO as absorbent were also discussed.

Solubility of CO2 in aqueous strontium hydroxide

The present communication represents the experimental results on CO2 solubility in aqueous Sr(OH)2 as an innovative absorbent. The absorption experiments were carried out over the temperature range of 303.14–333.14K and CO2 inlet partial pressure range of 10.133–20.265kPa in the light of coal-fired thermal power plant stack gases using a bubble column. The concentration of Sr(OH)2 was varied from 12.548 to 26.08g Sr(OH)2/100g water. All parameters viz., CO2 inlet partial pressure, temperature and the absorbent concentration showed positive effects on CO2 solubility. The CO2 absorption in aqueous Sr(OH)2 was found to follow first order rate kinetics. The results showed that Sr(OH)2 can be an efficient absorbent for removal of CO2 due to the formation of useful product SrCO3 after absorption.

Mechanical–Thermal Properties and VOC Emissions of Natural-Flour-Filled Biodegradable Polymer Hybrid Bio-Composites

The mechanical–thermal properties and volatile organic compound (VOC) emissions of natural-flour-filled, biodegradable polymer bio-composites were investigated according to variation in porous inorganic filler types. At a porous inorganic filler content of 3%, the tensile and flexural strengths of the hybrid bio-composites were not significant changed. However, the coefficient of thermal expansion and thermal expansion of the bio-composites were slightly decreased. Furthermore, the incorporation of the porous inorganic materials into bio-composites slightly increased the E’ values of the hybrid bio-composites over the entire temperature range, although the tan δmax temperature (T g) of the hybrid bio-composites was not significantly changed. At a porous inorganic filler content of 3%, the various odor and VOC emissions of the hybrid bio-composites were significantly decreased because the various oxidation and thermal degradation gases of the natural flour and matrix were absorbed in the pore structures of the porous inorganic fillers and thereby prevented the migration into the final products.

Extracting density–density correlations from in situ images of atomic quantum gases

We present a complete recipe to extract the density–density correlations and the static structure factor of a two-dimensional (2D) atomic quantum gas from in situ imaging. Using images of non-interacting thermal gases, we characterize and remove the systematic contributions of imaging aberrations to the measured density–density correlations of atomic samples. We determine the static structure factor and report the results on weakly interacting 2D Bose gases, as well as strongly interacting gases in a 2D optical lattice. In the strongly interacting regime, we observe a strong suppression of the static structure factor at long wavelengths.

Cavity-enhanced Rayleigh scattering

We demonstrate Purcell-like enhancement of Rayleigh scattering into a single optical mode of a Fabry–Perot resonator for several thermal atomic and molecular gases. The light is detuned by more than an octave, in this case by hundreds of nanometers, from any optical transition, making particle excitation and spontaneous emission negligible. The enhancement of light scattering into the resonator is explained quantitatively as an interference effect of light waves emitted by a classical driven dipole oscillator. Applications of our method include the sensitive, non-destructive in situ detection of ultracold molecules.

Control of dipolar relaxation in external fields

We study dipolar relaxation in both ultra-cold thermal and Bose-condensed chromium atom gases. We show three different ways to control dipolar relaxation, making use of either a static magnetic field, an oscillatory magnetic field, or an optical lattice to reduce the dimensionality of the gas from 3D to 2D. Although dipolar relaxation generally increases as a function of a static magnetic field intensity, we find a range of non-zero magnetic field intensities where dipolar relaxation is strongly reduced. We use this resonant reduction to accurately determine the S=6 scattering length of chromium atoms: $a_6 = 103 \pm 4 a_0$. We compare this new measurement to another new determination of $a_6$, which we perform by analysing the precise spectroscopy of a Feshbach resonance in d-wave collisions, yielding $a_6 = 102.5 \pm 0.4 a_0$. These two measurements provide by far the most precise determination of $a_6$ to date. We then show that, although dipolar interactions are long-range interactions, dipolar relaxation only involves the incoming partial wave $l=0$ for large enough magnetic field intensities, which has interesting consequences on the stability of dipolar Fermi gases. We then study ultra-cold chromium gases in a 1D optical lattice resulting in a collection of independent 2D gases. We show that dipolar relaxation is modified when the atoms collide in reduced dimensionality at low magnetic field intensities, and that the corresponding dipolar relaxation rate parameter is reduced by a factor up to 7 compared to the 3D case. Finally, we study dipolar relaxation in presence of radio-frequency (rf) oscillating magnetic fields, and we show that both the output channel energy and the transition amplitude can be controlled by means of rf frequency and Rabi frequency.

Gas geochemistry of the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Implications for gas hydrate exploration in the Arctic

Gases were analyzed from well cuttings, core, gas hydrate, and formation tests at the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well, drilled within the Milne Point Unit, Alaska North Slope. The well penetrated a portion of the Eileen gas hydrate deposit, which overlies the more deeply buried Prudhoe Bay, Milne Point, West Sak, and Kuparuk River oil fields. Gas sources in the upper 200 m are predominantly from microbial sources (C 1 isotopic compositions ranging from −86.4 to −80.6‰). The C 1 isotopic composition becomes progressively enriched from 200 m to the top of the gas hydrate-bearing sands at 600 m. The tested gas hydrates occur in two primary intervals, units D and C, between 614.0 m and 664.7 m, containing a total of 29.3 m of gas hydrate-bearing sands. The hydrocarbon gases in cuttings and core samples from 604 to 914 m are composed of methane with very little ethane. The isotopic composition of the methane carbon ranges from −50.1 to −43.9‰ with several outliers, generally decreasing with depth. Gas samples collected by the Modular Formation Dynamics Testing (MDT) tool in the hydrate-bearing units were similarly composed mainly of methane, with up to 284 ppm ethane. The methane isotopic composition ranged from −48.2 to −48.0‰ in the C sand and from −48.4 to −46.6‰ in the D sand. Methane hydrogen isotopic composition ranged from −238 to −230‰, with slightly more depleted values in the deeper C sand. These results are consistent with the concept that the Eileen gas hydrates contain a mixture of deep-sourced, microbially biodegraded thermogenic gas, with lesser amounts of thermogenic oil-associated gas, and coal gas. Thermal gases are likely sourced from existing oil and gas accumulations that have migrated up-dip and/or up-fault and formed gas hydrate in response to climate cooling with permafrost formation.

The submarine hydrothermal system of Panarea (Southern Italy): biogeochemical processes at the thermal fluids - sea bottom interface

Among the submarine hydrothermal systems located off-shore the volcanic archipelago of the Eolian Islands (Southern Italy), the most active is located off the coasts of Panarea Island. Thermal waters, gases and sulphur deposits coexist at the sea bottom where hydrothermal fluids are released from both shallow and deep vents. The chemical and isotopic composition of the fluid phase shows the presence of a significant magmatic component and the physico-chemical conditions of the geothermal reservoir allow the release of reduced chemical species that are microbially mediated towards the production of organic carbon as a form of biochemical energy. Mi- croorganisms inhabiting this environment possess nutritional requirements and overall metabolic pathways ide- ally suited to such ecosystem that represents a clear example of the close connection between geosphere and biosphere. Microscopic examination of the white mat attached to rock surfaces showed the presence of Thio- thrix-like filamentous bacteria. Moderately thermophilic heterotrophic isolates were identified as strains of the genus Bacillus. Although the hydrothermal system of Panarea has to be considered a «shallow» system, it shows many characteristics that make it similar to the «deep» oceanic systems, giving a unique opportunity for improv- ing our knowledge on such an unexplored world by working at this easily accessible site.

Thermalization of incoherent nonlinear waves

The subject of incoherent nonlinear optics received a renewed interest since the first experimental demonstration of incoherent solitons in slowly responding photorefractive crystals. Several theories have been successfully developed to provide a detailed description of the dynamics of incoherent optical solitons. However, such theories leave unanswered the question regarding the long term evolution of a partially incoherent optical field propagating in a nonlinear medium. In analogy with kinetic gas theory, an incoherent optical field evolves, owing to nonlinearity, towards a thermodynamic equilibrium state. Wave turbulence theory describes the essential properties of this irreversible process of thermal wave relaxation to equilibrium. Such irreversible behavior is expressed by a H-theorem of entropy growth, whose origin is analogous to the celebrated Boltzmann’s H-theorem. In this review we analyze the thermalization of incoherent nonlinear optical fields in various circumstances. We shall begin with the simplest case where the optical field is ruled by the scalar NonLinear Schrodinger (NLS) equation. In this case wave thermalization is characterized by a condensation process of the optical field, whose thermodynamic properties are analogous to those of Bose-Einstein condensation, despite the fact that the considered optical wave is completely classical. We then study the thermalization of an ensemble of incoherent fields governed by the vector NLS equation. The influence of the relative intensity of the coupled fields reveals the existence of a process of coherence absorption: The condensation of the optical field is induced by the presence of another small-amplitude field, which absorbs almost all the noise of the system. Such a coherence absorption effect is shown to also occur in thermal quantum Bose gases. The influence of convection (group-velocity difference) on the thermalization process is also analyzed. A set of incoherent wave-packets is shown to irreversibly evolve towards an equilibrium state in which they propagate with an identical group-velocity. This velocity-locking effect has a thermodynamic origin and thus appears as a generic property of a system of incoherent nonlinear waves. The influence of a coherent coupling on wave thermalization leads to an unexpected process of spontaneous polarization of unpolarized incoherent light, without loss of energy. Finally, the influence of higher-order dispersion effects on optical thermalization is responsible for a dramatic spectral broadening phenomenon known as supercontinuum generation. This reveals that supercontinuum generation may be regarded as a consequence of the natural thermalization of an optical field to equilibrium. We finally show that the thermodynamic properties of incoherent nonlinear waves may be analyzed by means of the fundamental T dS equation of thermodynamics.