Foreign Gas Research Articles

Numerical evaluation of heat/mass transfer analogy for leading edge showerhead film cooling on a first-stage vane

A numerical study was conducted to evaluate the applicability of the heat/mass transfer analogy to leading edge film cooling on a first-stage vane. A typical showerhead configuration was taken into account, thus including four staggered rows of evenly spaced cylindrical holes, angled at 45° towards the tip. The investigation was carried out at low speed (isentropic exit Mach number of Ma2is = 0.2), inlet turbulence intensity of Tu1 = 1.6% and 13%, and three different blowing ratios (BR = 2.0, 3.0 and 4.0). Steady-state simulations were conceived to mimic the pressure sensitive paint (PSP) technique aiming to measure the adiabatic film cooling effectiveness (η) in the leading edge region, under a density ratio of DR = 1 and 1.5. With the mainstream flow assumed to be air at ambient temperature, the desired DR was obtained by injecting coolant as air at different temperature from the mainstream (namely, heat transfer approach) or as isothermal foreign gas (namely, mass transfer approach). Despite the dominant effect of the DR on η, results indicated that the heat/mass transfer properties of the coolant are to be considered when comparing film cooling performance, at matched BR conditions. At low inlet turbulence intensity, the heat/mass transfer analogy was found to be applicable only to the lowest BR of 2.0. Its validity was extended to the medium BR of 3.0, in case of DR = 1.5, provided that the leading edge is approached by high turbulence intensity flow.

The value of post-mortem computed tomography of burned victims in a forensic setting

ObjectivesFire deaths are challenging fatalities for forensic pathologists, as the main question of whether death was due to the fire or not needs to be answered. In this retrospective study, we assessed whether post-mortem computed tomography (PMCT) has an added value prior to a forensic autopsy of burned victims.MethodsFrom 2008 to 2016, a PMCT was performed in 50 burned corpses prior to a complete forensic autopsy. In retrospect, all 50 PMCT scans were systematically assessed by a forensically experienced radiologist, masked from the autopsy reports. Subsequently, the PMCT findings were compared with the autopsy reports.ResultsHeat fractures, contractions and destruction of extremities, subcutaneous emphysema and post-mortem gas collections were easier to detect by PMCT compared to autopsy. Alterations by penetrating and blunt trauma and the presence of foreign bodies were easy to detect by PMCT as well by autopsy. PMCT was, however, not successful in detecting signs of vitality during the fire, detection of superficial thermal injuries and to answer the main question of the forensic autopsy, which is to investigate the cause of death.ConclusionsPMCT prior to autopsy is a valuable add-on in the post-mortem forensic investigation of burned victims for detection of hidden signs of trauma, gas collections and foreign bodies. However, since PMCT cannot answer the two main questions in forensic examination—determining the cause of death and detecting signs of vitality during the fire—it cannot replace an autopsy.Key Points• Post-mortem CT (PMCT) in burned victims shows hidden signs of trauma.• Foreign bodies and gas collections can easily be detected.• Cause of death and vitality signs cannot be assessed by PMCT.

Shale Gas Production in the Post-Soviet Countries: First Results and Problems

This chapter considers the approaches and possibilities of exploration and use of shale gas in the countries of the former USSR. Many of them became interested in the results of the US “shale revolution” which opened the new stage in gas production. Some post-Soviet countries are eager by using shale gas to reduce their dependence on external deliveries, thus, attaining energy independence.The data on shale gas reserves in the post-Soviet countries are taken together; the preliminary results of energy policy in these countries concerning development of the shale gas deposits are presented; the first results of oil and gas company activities are analyzed.Of all post-Soviet countries, Ukraine was most active in this respect having declared about possessing the greatest shale gas reserves. Ukraine invited foreign oil and gas companies which showed interest in the shale deposits. But the shale gas production in Ukraine acquired political dimensions impeding the objective assessment of startup conditions and likely consequences of shale gas extraction for the people and natural environment. Shale gas was in the focus of attention of the authorities in Kazakhstan and Moldavia which considered this hydrocarbon resource as the significant factor for diversification of hydrocarbon supply and ensuring independence of the Russian gas. “Shale revolution” was not neglected in Russia which had to take into account the shale gas factor in the world energy balance adjusting its policy respectively. USA made attempt to push its shale contracts in Russia, thus, ensuring access to the Russian gas market. On the one hand, Russia remained indifferent to the shale boom and went on implementation of its pipeline projects, but, on the other hand, it does not waive off absolutely the potential of this hydrocarbon resource.In general, the post-Soviet countries regardless of the lack of a legislative base, technologies and unresolved environmental issues have shown certain interest in shale gas production.

EXPANSION OF INTERNATIONAL TRADE WITH RUSSIAN GAS FOR THE ACCOUNT OF ITS DIVERSIFICATION AND USE OF INNOVATIVE DIRECTIONS

The article is devoted to the gas export of the Russian Federation, as well as to the search for solutions to the problems arising in the process of foreign gas trading by Russian gas companies. It is specially noted that, as a serious shortcoming of gas exports from Russia, it is only one-pointedness to European countries (mainly to EU countries) and Turkey. In addition, it is pointed out that the supply of natural gas (GHG) from the Russian Federation is carried out with a few exceptions only through pipeline systems. All this puts Gazprom and a number of other Russian gas companies in greater dependence, both from direct European importers and from GHG transit countries. It will be possible to solve the problem of diversification and reliability of gas export to the far abroad of the Russian Federation only due to a certain transition to a new technological type of storage and transportation of NG – in liquefied state. In this case, Russian gas companies will be able to export LNG not only via pipelines to a limited number of countries, but also in the form of liquefied natural gas (LNG) by gas tanks to many countries of the world. This will expand the scale of gas trade to the size of oil trading operations. Russian gas companies and Gazprom, using innovative forms of trade in illegal volumes of LNG in the form of spot, futures and forward contracts, will be able to carry out more flexible trading operations and receive increased profits. At the same time, their dependence on European consumers of Russian pipeline PG and transit countries will decrease.

Foreign gas effect on the [formula omitted] optical transition of molecular oxygen under high pressure conditions

We aim to understand foreign gas effect on A-band of oxygen that is optical forbidden b1Σg+(v=0)←X3Σg-(v=0) transition. To measure the absorption of weak A-band, a high pressure absorption spectroscopy system was constructed. We found absorbance around A-band of O2/M (N2, CO2, SF6, Ne, Ar, Kr, Xe) gas mixture were larger than that of pure O2. This enhancement by foreign gases was discussed from a view point of heavy atom and polarizability effects under the light of the presented mechanism of the heavy atom effect. We performed quantitative analysis on the enhancement by noble gases, which are monoatomic molecules, as a foreign gas. The polarizability effect was examined by using SF6 as a foreign gas, which is a simple molecule with large polarizability.

Ultrasonic-Assisted Soldering of Low-Ag SAC Lead-Free Solder Paste at Low-Temperature

SAC0307 (Sn-0.3mass%Ag-0.7mass%Cu) lead-free solder pastes were used to complete Cu/Cu joint by ultrasonic-assisted. Effect of nano-Ni particles and temperature on the performance of joint by ultrasonic-assisted with lead-free solder paste were investigated. The experimental results have shown that interfacial IMC of joint with SACP were typical scallop-type, but the type of interfacial IMC were serrated and became smoother after added nano-Ni particles. The IMC thickness was not more than 6.00 μm and the IMC thickness of SACP joint was slightly thick comparing with SACPC joint at the same temperature. Interfacial IMC of SACP joint at 210℃ was mainly composed of a layer of thick Cu6Sn5 and thin Cu3Sn, and the concentration gradients of Cu and Sn in IMC were also obviously. The composition of IMC was Cu3Sn7 in SACPC joint at 210℃, there were no different and the composition was Cu42.5Sn57.5 whether nano-Ni particles were added at 240℃. The strength of two kinds of joints were increased first and then decreased with the increase of ultrasonic time at 210℃～220℃, but decreased in both joints at 240℃. The shear strength of SACP joint was only 31.59 MPa, but the shear strength of SACPC joint reached the peak value of 41.20 MPa at 5 s by ultrasonic-assisted at 210℃, were about 0.32 and 19.80 percent more than that of no ultrasonic-assisted. The shear strength of SACP joint and SACPC joint reached the peak value of 38.80 MPa and 41.96 MPa after ultrasonic vibration for 0 s at 240℃, but decreased to the minimum of 22.47 MPa and 21.11 MPa after ultrasonic-assisted at 5 s and 10 s, were about 42.09 and 49.69 percent less than that of no ultrasonic-assisted respectively. Ultrasound can help fill the solder seam to increase the shear strength, but slag inclusion and foreign gases would gather and grow up to lead decreasing of the shear strength at 210℃～220℃. Slag inclusion and foreign gases were wrapped into the seam and not easy to overflow under the liquid state in the liquidus nearby, would gather to the interface of IMC/solder and grow up to lead decreasing of the shear strength under the the ultrasonic vibration at 240℃. Nano-Ni particles also played a part in increasing the strength of joints.

Second Galicia? Poland's shale gas rush through historical lenses

Abstract Since the early 2000s, the exploitation of shale gas has radically modified the US energy scenario. In a number of European countries, the US boom has elicited questions about its repeatability in Europe. Among the staunchest supporters of the development of national shale-gas resources were Polish administrations, which grounded their activism in this domain in the language of energy security, autonomy vis-à-vis Russian gas, and in Poland's old oil history. The history of hydrocarbon exploration in the country dates back to the mid-nineteenth century, and is connected to the oil boom that occurred in the region of Galicia. While the boom was over by World War I, promising estimations made in recent years by several agencies about Poland's shale gas reserves have stirred hopes of a ‘second Galicia’. From 2007, the Polish government started assigning permits to both national and foreign gas companies. However, factors linked to legislation, geology and macroeconomics caused a premature end to hopes of Polish autonomy. After a reconstruction of the history of oil in Galicia and the constitution of the Polish oil and gas sector, this paper narrates the rise and fall of Poland's ‘affair’ with shale gas.

The Effect of Menisci on Kinetic Analysis of Evaporation for Molten Alkali Metal Salts (CsNO3, CsCl, LiCl, and NaCl) in Small Cylindrical Containers

Using isothermal thermogravimetric data of alkali metal salts (CsNO3, CsCl, LiCl, and NaCl), we conducted kinetic analysis on atmospheric evaporation to investigate the effect of meniscus on determining the condensation coefficient. In the process of evaporation into an atmospheric gas, molten salt decomposed at the interface between molten salt and an atmospheric gas reacts with chemical compositions of the atmospheric gas to be an equilibrium state. In this atmospheric evaporation, the interface shape of molten salts is affected by the container diameter and the contact angle at the container wall. In the analysis results, the formed concave/convex meniscus led to underestimating the condensation coefficient of molten salts. However, whether the values of the condensation coefficient of molten salts were affected by menisci, the range of the predicted values was still low from 10−3 to 10−5. This result means that the presence of the foreign gas (air and Ar) is a dominant parameter in determining the condensation coefficient of atmospheric evaporation.

LIDAR TS for ITER core plasma. Part III: calibration and higher edge resolution

Calibration, after initial installation, of the proposed two wavelength LIDAR Thomson Scattering System requires no access to the front end and does not require a foreign gas fill for Raman scattering. As already described, the variation of solid angle of collection with scattering position is a simple geometrical variation over the unvignetted region. The additional loss over the vignetted region can easily be estimated and in the case of a small beam dump located between the Be tiles, it is within the specified accuracy of the density. The only additional calibration is the absolute spectral transmission of the front-end optics. Over time we expect the transmission of the two front-end mirrors to suffer a deterioration mainly due to depositions. The reduction in transmission is likely to be worse towards the blue end of the scattering spectrum. It is therefore necessary to have a method to monitor such changes and to determine its spectral variation. Standard methods use two lasers at different wavelength with a small time separation. Using the two-wavelength approach, a method has been developed to determine the relative spectral variation of the transmission loss, using simply the measured signals in plasmas with peak temperatures of 4–6 keV . Comparing the calculated line integral of the fitted density over the full chord to the corresponding interferometer data we also have an absolute calibration. At the outer plasma boundary, the standard resolution of the LIDAR Thomson Scattering System is not sufficient to determine the edge gradient in an H-mode plasma. However, because of the step like nature of the signal here, it is possible to carry out a deconvolution of the scattered signals, thereby achieving an effective resolution of ∼ 1–2 cm in the outer 10–20 cm.

Ice crystal growth under the presence of krypton and methane at low temperature

To investigate the influence of foreign gas inclusion on the crystallization of ice, we studied the low-temperature (74 < T < 160 K) vacuum deposition of water molecules mixed with Kr or CH4 in a wide range of H2O/gas mixing ratios (0.004 < R < 4) by means of in-situ X-ray diffraction. When H2O vapor containing either Kr or CH4 was condensed onto a cold substrate, ice Ih crystals were found to grow below 130 K in a film of amorphous solid water (ASW), whereas pure H2O gas formed only ASW below 135 K. Small to moderate concentrations (R > 0.2) of Kr and CH4 enhance the formation of ice Ih and increase the crystal size, while at high foreign gas contents (R ⩽ 0.2) that may develop Kr or CH4 crystals below 92 K, the crystal size and relative amount of ice decrease strongly. The maximum ice Ih crystal size in the order of 200 nm was observed with either Kr or CH4 at 92 K for R = 0.2. We propose that Kr and CH4 induce the crystallization of ice by acting as a surfactant.

A Critical Appraisal of Nigeria’s Proposed Oil Industry Governance and Regulatory Framework: Implications for Foreign Oil Companies Operating in Nigeria.

An evaluation of Nigeria’s proposed oil industry governance and regulatory framework, and its implications for foreign oil and gas investors. It begins with an Examination of the evolution of the Petroleum Industry Governance Bill(PIGB) vis-a-vis an assessment of the proposed changes within the PIGB. This will be achieved by investigating how the re-structuring of the Nigerian National Petroleum Corporation(NNPC) will affect the existing joint ventures and the production sharing contracts held by the foreign oil and gas investors. More so, an attempt will also be made to determine whether the issue of change of laws may be deemed ‘tantamount to expropriation.’ Several questions will be raised regarding the manner in which International Investment law restricts the Host States regulatory autonomy and how tribunals have attempted to strike a balance between the issue of investment protection and the preservation of the host State regulatory autonomy: an issue which has become so difficult to resolve. And through these issues, disputes may arise, thus, the settlement of investment disputes shall be considered. It is noteworthy that, this dissertation is examining the draft of the PIGB as at present, because it might change.

Effects of Coolant Density, Specific Heat Capacity, and Biot Number on Turbine Vane Cooling Effectiveness

This paper describes the effects of coolant-to-mainstream density ratio and specific heat capacity flux ratio (the product of blowing ratio and specific heat capacity ratio) on the overall cooling effectiveness of high pressure (HP) turbine vanes. Experimental measurements have been conducted at correct engine-matched conditions of Mach number, Reynolds number, turbulence intensity, and coolant-to-mainstream momentum flux ratio. Vanes tested were fully cooled production parts from an engine currently in service. A foreign gas mixture of SF6 and Ar was selected for injection as coolant in the facility so that density and blowing ratios were also matched to the engine situation. The isentropic exponent of the foreign gas mixture coincides with that of air. Full-coverage surface maps of overall cooling effectiveness were acquired by an infrared (IR) thermography technique at a range of mainstream-to-coolant temperature ratios. Measurements were subsequently scaled to engine conditions by employing a new theory based on the principle of superposition and a recovery and redistribution temperature demonstrated in previous papers. It is shown that the two aerodynamically matched situations of air- and foreign-gas-cooled experiments give virtually the same effectiveness trends and patterns. Actual levels differ, however, on account of specific heat capacity flux ratio differences. The effect is described and quantified by a one-dimensional analytical model of the vane wall. Differences in Biot number with respect to engine conditions are discussed as they also influence the scaling of turbine metal temperatures.

Modelling an optimal foreign natural gas import scheme for China

Following China's pledge to mitigate GHG emissions, natural gas has become an important choice for promoting low-carbon development in the country. China has introduced natural gas-friendly policies to increase the penetration of natural gas into its total energy consumption, causing an increase in the demand for foreign natural gas in China. This study attempts to devise a foreign natural gas import scheme for China by constructing a mathematical programming model. Various aspects of energy security, such as diversification, lower dependency, supplier export capacity, minimizing the import cost, transport distance and political instability associated with each of the foreign natural gas suppliers, were incorporated in the decision-making model for a foreign natural gas import scheme for the years 2015–2020. The proposed model optimizes China's strategy by utilizing the existing capacity of the piped natural gas (PNG) infrastructure and gradually increasing the liquefied natural gas (LNG) supply from the top six suppliers in the world, i.e. Qatar, Malaysia, Australia, Nigeria, Indonesia, Trinidad & Tobago and Algeria. Furthermore, the analysis of the existing and planned LNG and PNG import infrastructure suggests that China will have more than enough import capacity to fulfil the demand for foreign natural gas in the country until 2020.

Nichtthrombotische Lungenembolien

The term nonthrombotic pulmonary embolism (NTPE) is defined as embolization of pulmonary arteries caused by foreign bodies (e. g. detached catheter fragments), biological substances (e. g. septic thrombus) or exogenous substances (e. g. gas). The frequency of NTPE is underestimated. Symptoms can cover the spectrum from undetectable to sudden death. In addition to mechanical obstruction of the pulmonary arteries, some NTPEs trigger an inflammatory cascade that causes deterioration of vascular, pulmonary and cardiac function. Radiological imaging in combination with the medical history of patients is sufficient to identify most NTPEs with certainty. The aim of this article is to make readers aware of the symptoms, frequency, relevance, classification, pathophysiology, laboratory findings and radiological findings of the most frequent forms of NTPE. The spectrum of forms presented here includes pulmonary embolisms due to foreign bodies (intravascular, intracorporeal and extracorporeal), amniotic fluid, endogenous tissue, fat, tumors, septic thrombi, hydatids, cement, metallic mercury, gas, silicone and particles.

Mexico Awards Its First Deepwater Blocks; What Comes Next?

Mexico’s historic public tender for its deepwater real estate resulted in the awarding of eight out of 10 blocks on offer. Held last December in Mexico City, the event marked the fourth and final auction of the country’s Round One, which reopened doors to foreign oil and gas investment for the first time since the country’s energy sector was nationalized almost 80 years ago. The awarded blocks went to 13 companies whose exploration and production operations are expected to generate around USD 34 billion over the next 15 years. The winning bids also committed to drill at least eight deepwater wells. All four blocks offered in the deep-water Perdido area were awarded, including two to Chinese Offshore Oil Corporation (CNOOC) and one to a consortium of Chevron, Pemex, and Inpex—Japan’s largest oil company. An additional four blocks in the Salina Basin were contracted to three different consortiums, including one formed by Statoil, BP, and Total. Another block encompassing a deep-water discovery known as the Trion field was awarded as a farmout agreement between BHP Billiton and Mexico’s state-owned oil company Pemex. BHP will acquire 60% of the project’s interest under the terms of the contract, which it won through a tie-breaking offer of a USD 624 million cash bonus to Mexico’s petroleum fund. BP was the losing bidder. Including the three previous onshore and shallow-water auctions, Mexico has awarded 39 exploration and production contracts to companies from nine foreign countries. In a press conference following the auction, the government said it expects to receive close to 60% of the combined profits from the eight blocks and the lone farmout. Mexican officials also said they are hoping the deepwater contracts eventually will yield 900,000 B/D of crude, a volume that would help stem the country’s declining production from existing fields. Government officials added that first production from Trion might be reached within 6 years, while it is expected that the other areas will need up to a decade to be developed. What’s Next? According to many observers, the production potential that the deep water holds for Mexico was the chief driver behind the country’s sweeping energy reforms that became law in 2013. But now that a number of the prime blocks have been allocated, what comes next? For the companies that have already signed offshore contracts, their next steps are likely to include the expansion of Mexico’s port facilities to accommodate the arrival of larger deepwater vessels and rigs. Some expect the small port town of Dos Bocas to become a deepwater hub because of its proximity to the southern Salina Basin blocks.

Detection of Ammonia and Phosphine Gas using Heterojunction Biomolecular Chain with Multilayer GaAs Nanopore Electrode

This paper presents Density Functional Theory and Non-Equilibrium Green’s Function based First Principles calculations to explore the sensing property of Adenine and Thymine based hetero-junction chins for Ammonia and Phosphine gas molecules. This modeling and simulation technique plays an important and crucial role in the fast growing semiconductor based nanotechnology field. The hetero-junction chain has been passed through the multi layer GaAs nanopore electrodes. It has been found that Current-Voltage characteristics of the bio-molecular chain highly depend during the foreign gas molecules adsorption. This Current-Voltage sensitivity has been raised upto 40 and 9.3 times with the presence of single Ammonia and Phosphine molecules respectively under the ultra low bias voltage application. Adsorption of single molecule Ammonia and Phosphine increases the conductivity of the heterogeneous bio-molecular chain at room temperature. The quantum ballistic transmission through the direct band gap semi-conductor material GaAs nanopore increases during the Ammonia and Phosphine gas adsorption by the heterogeneous chain. In this paper we attempt to present the molecular model sensor with circuit elements. The attractive potential of conductivity modulation suggests this heterogeneous bio-molecular chain as an application in future generation bio-sensor technology.

Prediction of marine shale gas production in South China based on drilling workload analysis

The marine shale gas resource in South China is abundant, but the existing conventional methods cannot meet the needs of predicting the future production development of shale gas. With the marine shale of the Lower Silurian Longmaxi Fm in this region as an example and based on its development potential, the development features of the existing shale gas resources were analyzed. It is considered that the Longmaxi shale gas accumulation zones in the Sichuan Basin and its neighboring areas contain resources of about 17.4 × 1012 m3 and recoverable resources of about 2.9 × 1012 m3. In particular, the shale gas above 3500 m underground is the main body for recent development targets, with a potential production scale about 300 × 108 m3. On this basis, the development features of foreign and domestic shale gas wells were studied and the drilling workload analytical method for the prediction of shale gas production was established: (1) the initial production of a single well can be used to characterize the productivity of the shale gas well, and its test production is approximate to its initial production. Due to the similarity of decline rate among shale gas wells, the single-well estimated ultimate recovery (EUR) value of a single well can be roughly speculated from its initial production, thus the production scale of a shale gas field can be speculated according to the analysis of drilling workload; (2) currently, the expected test production of South China marine shale gas is 17.6 × 104 m3/d, and the predicted single-well EUR value is roughly 1.5 × 108 m3. It is concluded that the marine shale gas in South China represents high initial production of a single well, high declining rate, longer production cycle and the drilling workload is closely related with the production of a shale gas field. Therefore, the analysis of drilling workload shows better applicability to the evaluation of shale gas production. Based on this method, the shale gas production of the Sichuan Basin and its neighboring area in 2020 was estimated to be about 200 × 108 m3.

COUNTRY IN MIDSTREAM

COUNTRY IN MIDSTREAM

043 - Better Thanthermodiluation: Validation of Foreign Gas Rebreathing for Noninvasive Measurement of Cardiac Output in Clinical Practice

043 - Better Thanthermodiluation: Validation of Foreign Gas Rebreathing for Noninvasive Measurement of Cardiac Output in Clinical Practice

Elements and gas enrichment laws of sweet spots in shale gas reservoir: A case study of the Longmaxi Fm in Changning block, Sichuan Basin

Identification of sweet spot is of great significance in confirming shale gas prospects to realize large-scale economic shale gas development. In this paper, geological characteristics of shale gas reservoirs were compared and analyzed based on abundant data of domestic and foreign shale gas reservoirs. Key elements of sweet spots were illustrated, including net thickness of gas shale, total organic carbon (TOC) content, types and maturity (Ro) of organic matters, rock matrix and its physical properties (porosity and permeability), and development characteristics of natural fractures. After the data in Changning and Weiyuan blocks, the Sichuan Basin, were analyzed, the geologic laws of shale gas enrichment were summarized based on the economic exploitation characteristics of shale gas and the correlation between the elements. The elements of favorable “sweet spots” of marine shale gas reservoirs in the Changning block and their distribution characteristics were confirmed. Firstly, the quality of gas source rocks is ensured with the continuous thickness of effective gas shale larger than 30 m, TOC > 2.0% and Ro = 2.4–3.5%. Secondly, the quality of reservoir is ensured with the brittle minerals content being 30–69%, the clay mineral content lower than 30% and a single lamination thickness being 0.1–1.0 m. And thirdly, the porosity is higher than 2.0%, the permeability is larger than 50 nD, gas content is higher than 1.45 m3/t, and formation is under normal pressure–overpressure system, which ensures the production modes and capacities. Finally, the primary and secondary elements that control the “sweet spots” of shale gas reservoirs were further analyzed and their restrictive relationships with each other were also discussed.