Stopping Gas Research Articles

Numerical model of interaction of a mobile lift chain with a main gas pipeline pipe in the process of repair work

The paper proposes an original design of a mobile lifting device for diagnosing and repairing support nodes of above-ground segments of gas pipelines without stopping gas transportation. When using such a device, the rollers of the lifting chain interact with the surface of the pipe, which can possibly cause additional stresses in the gas pipeline. At the first stage of studying this problem, a model of a typical gas pipeline overhead crossing for the Carpathian region was built and the maximum operating force that should be developed by the mobile lift during repair operations was determined. At the second stage, a finite-element model of the interaction of the mobile lift chain with the main gas pipeline pipe was built. The additional equivalent stresses arising from the contact of the rollers of the lifting chain with the pipe surface were estimated. Recommendations are given to ensure the safe operation of the gas pipeline when using a mobile lift for local lifting of the pipe above the support of above-ground segments of gas pipelines.

Utilizing innovative nanolime-geopolymer as a cement for gas wells

This paper is to introduce the formulation of the innovative nanolime-geopolymer NLGP and its application in gas wells as a replacement for the traditional cement. The new mix is composed of nanolime NL, fly ash, sodium hydroxide, and sodium silicate. The compressive strengths of NLGP are measured using different molarities, and ratios of its components to compare and evaluate the results. After that, a detailed profit study in USD will show the profitability of NLGP compared to other types of current cement and the possibility of its manufacturing. Also, a separate comparison to cement fly ash CF was done. Finally, the “deep water horizon” incident will be used as a case study to indicate the applicability of NLGP in such cases for stopping gas channeling which occurs due to cement job failure.

Development of a D–D neutron spectrum detector based on helium-3 proportional counter

Deuterium–deuterium (D–D) neutron spectrum diagnostics in tokamaks are a challenging task with current technologies. To address this issue, we designed and tested a fast and compact helium-3 proportional counter with a diameter of 2.5 cm and an effective length of 15 cm and using Kr as a stopping gas. The detector achieved a resolution of 96 keV for 2.406 MeV neutrons with a pulse shaping of 2 µs. Test results indicate that this detector has the potential to form a D–D neutron spectrometer for tokamaks, composed of detector arrays.

EUV debris mitigation using magnetic nulls

Next generation EUV sources for photolithography use light produced by laser-produced plasmas (LPP) from ablated tin droplets. A major challenge for extending the lifetime of these devices is mitigating damage caused by deposition of tin debris on the sensitive collection mirror. Especially difficult to stop are high energy (up to 10 keV) highly charged tin ions created in the plasma. Existing solutions include the use of stopping gas, electric fields, and magnetic fields. One common configuration consists of a magnetic field perpendicular to the EUV emission direction, but such a system can result in ion populations that are trapped rather than removed. We investigate a previously unconsidered mitigation geometry consisting of a magnetic null by performing full-orbit integration of the ion trajectories in an EUV system with realistic dimensions and optimize the coil locations for the null configuration. The magnetic null prevents a fraction of ions from hitting the mirror comparable to that of the perpendicular field, but does not trap any ions due to the chaotic nature of ion trajectories that pass close to the null. This technology can potentially improve LPP-based EUV photolithography system efficiency and lifetime and may allow for a different, more efficient formulation of buffer gas.

A New Relantioship for the Prediction of the Formation of Gas Hydrate in Fluids Petroleum

The presence of gas hydrates in natural gas extraction, transport and storage facilities, creates problems related to the blocking of flow pores in the productive layer, the clogging of pipelines and especially the increase in the delivery and pumping pressure of natural gas. This aspect usually leads to damage to oil structures by damaging them and especially by stopping gas supplies. The present work presents the history of the identification of natural gas hydrates present in nature as well as their nucleation conditions.
 Also, following the laboratory determinations, two new correlations could be made to indicate the pressure and temperature at the beginning of the nucleation of gas hydrates, starting from the determination of their specific gravity.
 The new correlations were compared with the laboratory data and with the existing correlations in the specialized literature, the results being close.
 Also, based on the observations of the formation of gas hydrates of some gases with a specific density between 0.6 and 1.0, it was possible to analyze the laboratory data with those obtained after running a new correlatios.

Energy Security of the European Union in the Context of Russian Aggression against Ukraine

Over the past decades, Russia has used the supply, ownership and control of energy resources as an instrument of its foreign policy to strengthen its political influence not only in the post-Soviet space, but also in the EU member states. During the unprovoked Russian aggression against Ukraine, Moscow used energy policy as an energy weapon (demanding to pay for gas in rubles; stopping gas supplies to certain EU member states, including Poland, Bulgaria, and Finland; reducing the volume of supplies through the Nord Stream pipeline; ignoring the capacities of the Ukrainian GTS; provoking an increase in gas prices), which resulted in an acute energy crisis in the European Union. This prompted the EU and national governments of its member states to make significant adjustments to their energy policies in order to overcome the crisis and prevent gas blackmail by European states as a manipulation to circumvent anti-Russian sanctions and political pressure to withdraw support for Ukraine. The purpose of the article is to study the problems of ensuring the energy security of the European Union and its member states in the context of the energy crisis caused by Russia's aggression against Ukraine. The article is aimed at studying the impact of Russian aggression on the EU's energy security, assessing the state of the Energy Union in 2022, and analyzing short-term and long-term strategies in the development of relevant supranational and national energy policies, mainly from a European perspective. Modern European national and supranational energy and climate strategies envisage postponing the phase-out of coal, oil, gas and nuclear power, while accelerating the deployment of renewable energy, improving energy efficiency and a mandatory commitment to increase energy storage. The European Union and its member states are overcoming the consequences of the energy crisis by developing and implementing national strategies, the REPowerEU plan, as well as a number of other measures to reduce energy prices and ensure security of supply. The REPowerEU plan is fully in line with the European Green Deal and includes measures to save energy, diversify and ensure security of supply, accelerate the deployment of renewable energy sources and a reasonable mix of investment and reform. The modernization of the EU's energy policy is aligned with the EU's long-term climate goals. The EU also supports new partnerships with neighboring countries, including Ukraine, to accelerate the global transition to green and fair energy.

How Nigeria Deals with Environmental Damages? An Environmental Legal Perspective

The paper carries out a review of the environmental problems associated with atmospheric pollution, air quality emissions and applicable control mechanisms in the detection and evaluation in the Niger Delta region of Nigeria in the light of global trends and best practices given the magnitude of gas flaring taking place in Nigeria’s Niger Delta daily. This is flowing from the findings that gas flaring continues to be a major health hazard to humanity, domestic and global environment. Also considered are the Challenges facing air quality and carbon management in Nigeria and the place of the ongoing National Space Research and Development Agency (NASRDA) funded research on air quality and carbon management and the recent release of the twin regulations of: the Flare Gas (Prevention Of Waste And Pollution) Regulations, 2018 and the Nigerian Gas Flare Commercialization Programme (NGFCP) by the Federal Government Of Nigeria aimed at stopping gas flares in the year, 2020. The paper adopts an admixture of the historical, comparative, the law and development and empirical approaches in appropriate cases.

A Reappraisal of the Environmental Problems of Atmospheric Pollution, Air Quality Emissions and Applicable Control Mechanisms in the Detection and Evaluation in the Niger Delta Region of Nigeria, Global Trends and Emerging Developments in the Light of

The paper carries out a review of the environmental problems associated with atmospheric pollution, air quality emissions and applicable control mechanisms in the detection and evaluation in the Niger Delta region of Nigeria in the light of global trends and best practices given the magnitude of gas flaring taking place in Nigeria’s Niger Delta daily. This is flowing from the findings that gas flaring continues to be a major health hazard to humanity, domestic and global environment. Also considered are the Challenges facing air quality and carbon management in Nigeria and the place of the ongoing National Space Research and Development Agency (NASRDA) funded research on air quality and carbon management and the recent release of the twin regulations of: the Flare Gas (Prevention Of Waste And Pollution) Regulations, 2018 and the Nigerian Gas Flare Commercialization Programme (NGFCP) by the Federal Government Of Nigeria aimed at stopping gas flares in the year, 2020. The paper adopts an admixture of the historical, comparative, the law and development and empirical approaches in appropriate cases. Keywords: Reappraisal, Environmental Problems, Atmospheric Pollution, Nuisance, Air Quality Emissions, Applicable Control Mechanisms, Detection, Evaluation, Niger Delta Region of Nigeria, Global Trends, Emerging Developments, The Flare Gas (Prevention of Waste and Pollution) Regulations, 2018. DOI : 10.7176/JLPG/92-17 Publication date: December 31 st 2019

Prospects of binary energy generation systems based on the joint use of traditional sources of energy and wave motion energy

Electricity consumption of offshore oil and gas drilling platforms is usually provided by gas generator installations. However, such installations are expensive in operation and emit significant amounts of carbon dioxide and nitrogen oxides. Electricity consumption from the main grid is the best option, but expensive for platforms located far from the coast and with limited environmental benefits, if not supported by environmentally friendly production. Offshore wave energy technology, which is currently being developed for deep-water areas, can be connected directly to the platforms and work in parallel with gas turbines. Wave power station will save fuel and reduce carbon dioxide emissions, while there is no need for a long and expensive connection to the coastal grids. Operational strategies and fuel savings and emissions, depending on the size of the wind farm, are quantified by the example of the offshore oil and gas platform in the Far East shelf. In this paper, an assessment is made of the prospects of using the approach of dual power generation systems, which in turn will provide a significant reduction in fuel consumption and emissions, especially if we consider starting and stopping gas turbines. The main task is to find the optimal work strategy that balances the number of starts and stops of gas turbines with dissipative energy and fuel economy.

A setup to develop novel Chemical Isobaric SEparation (CISE)

Gas catchers are widely used to thermalize nuclear reaction products and subsequently extract them for precision measurements. However, impurities in the inert stopping gas can chemically react with the ions and thus influence the extraction efficiency. So far, chemical reactions in the gas-catcher have not been investigated in detail. Therefore, we are currently building a new setup to develop Chemical Isobaric SEparation (CISE) with the aim to understand the chemistry inside the gas-catcher and to explore its potential as a new technique for separation of isobars. In this paper, we give a short description of the setup together with the ion transportation studies performed via ion-optics simulations.

Development of high-pressure multi-wire proportional chamber neutron detector for the China Spallation Neutron Source multipurpose reflectometer

As a multipurpose reflectometer device, the two-dimensional (2D) position resolution neutron detector with a 200 mm×200 mm effective area is developed for China Spallation Neutron Source (CSNS) in Dongguang, China. Due to the requirements for the specific parameters of the multipurpose reflectometer, it should be designed to have a more than 50% (@2 Å) detection efficiency, better than 2 mm position resolution and 3 times n/γ resolution ability during the whole operation period of 10 years. The high pressure multi-wire proportional chamber (MWPC) neutron detector filling 3He gas is used as a key detector. Some simulation results and the experimental results show that the optimized thickness of the neutron entrance window should be 9 mm with using the 7075 aluminum alloy, the high pressure chamber should be sealed by the aluminous ring and a gas mixture should be filled with 6 bar 3He+2.5 bar C3H8. The assembled detector can achieve a more than 54% (@2 Å) detection efficiency in the normal operation.With the 100 μm wide collimator slit, the position resolution for X-rays is about 0.235 mm. Therefore, the position resolution for neutron is about 1.4 mm when 2.5 bar propane is used as the stopping gas for proton and triton. In the chamber, the water vapor, the oxygen and the organic impurity gases will reduce the gas gain, cause the detector electrodes to break down and the detector to speed up aging. To solve the outgassing effect of the detector components and keep the stable operation, the recycled device is designed to have the purification function for the working gases. It could purify the working gas at a flow rate of 2 L/min to remove the oxygen, the water vapor and the organic impurity gases. The detector gain increases about 27% with the purification function. Finally, the n/γ resolution and 2D imaging ability of the detector are tested with the 252Cf neutron source in Institute of High Energy Physics, Chinese Academy of Sciences, the peak ratio of neutron to gamma is obtained to be above 5 from the energy spectra and the detecor has good 2D imaging ability. The performance of the high-pressure MWPC neutron detector could meet the requirements for the multipurpose reflectometer, and the detector will be mounted in the CSNS in this year.

Developments towards in-gas-jet laser spectroscopy studies of actinium isotopes at LISOL

To study exotic nuclides at the borders of stability with laser ionization and spectroscopy techniques, highest efficiencies in combination with a high spectral resolution are required. These usually opposing requirements are reconciled by applying the in-gas-laser ionization and spectroscopy (IGLIS) technique in the supersonic gas jet produced by a de Laval nozzle installed at the exit of the stopping gas cell. Carrying out laser ionization in the low-temperature and low density supersonic gas jet eliminates pressure broadening, which will significantly improve the spectral resolution. This article presents the required modifications at the Leuven Isotope Separator On-Line (LISOL) facility that are needed for the first on-line studies of in-gas-jet laser spectroscopy. Different geometries for the gas outlet and extraction ion guides have been tested for their performance regarding the acceptance of laser ionized species as well as for their differential pumping capacities. The specifications and performance of the temporarily installed high repetition rate laser system, including a narrow bandwidth injection-locked Ti:sapphire laser, are discussed and first preliminary results on neutron-deficient actinium isotopes are presented indicating the high capability of this novel technique.

Conceptional design of a novel next-generation cryogenic stopping cell for the Low-Energy Branch of the Super-FRS

The conceptual design of a next-generation cryogenic stopping cell (CSC) for the Low-Energy Branch (LEB) of the Super-FRS has been developed. It builds on advanced techniques implemented in the prototype version of the CSC, which has recently been commissioned as part of the FRS Ion Catcher with 238U projectile and fission fragments produced at 1000MeV/u. These techniques include cryogenic operation to ensure a high purity of the stopping gas and high-density operation enabled using an RF carpet with a small electrode structure size. The next generation CSC implements several novel concepts (e.g. perpendicular extraction) which lead to enhanced performance compared to the prototype CSC: (i) extremely short extraction times, (ii) higher rate capability, (iii) increased areal density without deteriorating extraction times, efficiencies or rate capability, (iv) minimized RF power, (v) precise range measurement of the ions and (vii) improved cleanliness of the CSC.

Production of exoctic fragments by photofission process combined with stopping gas cell at ELI-NP facility

Extreme Light Infrastructure Nuclear Physics (ELI-NP) facility is being built at Bucharest-Magurele, which then allow us to do research about nuclear physics using a new set of research tools: high power laser system and high brilliance gamma beams. One of day-one experiment proposed at this facility is to study the photofission of actinide by the high-intensity gamma beam through measurement of mass and beta decay. In addition, ternary fission will be also studied. In particular, the measurements of exotic neutron-rich nuclei produced by photofission, especially isotopes of refractory elements, is of great interest and requires the development of an IGISOL-type (Ion guide isotope separation online). In this report, we will present benchmark simulation of photofission rate and rates of related background processes.

Design, construction and cooling system performance of a prototype cryogenic stopping cell for the Super-FRS at FAIR

A cryogenic stopping cell for stopping energetic radioactive ions and extracting them as a low energy beam was developed. This first ever cryogenically operated stopping cell serves as prototype device for the Low-Energy Branch of the Super-FRS at FAIR. The cell has a stopping volume that is 1m long and 25cm in diameter. Ions are guided by a DC field along the length of the stopping cell and by a combined RF and DC fields provided by an RF carpet at the exit-hole side. The ultra-high purity of the stopping gas required for optimum ion survival is reached by cryogenic operation. The design considerations and construction of the cryogenic stopping cell, as well as some performance characteristics, are described in detail. Special attention is given to the cryogenic aspects in the design and construction of the stopping cell and the cryocooler-based cooling system. The cooling system allows the operation of the stopping cell at any desired temperature between about 70K and room temperature. The cooling system performance in realistic on-line conditions at the FRS Ion Catcher Facility at GSI is discussed. A temperature of 110K at which efficient ion survival was observed is obtained after 10h of cooling. A minimum temperature of the stopping gas of 72K was reached. The expertise gained from the design, construction and performance of the prototype cryogenic stopping cell has allowed the development of a final version for the Low-Energy Branch of the Super-FRS to proceed.

Lung re-inflation after one-lung ventilation for thoracic surgery: importance of clamping the dependent lung

To the Editor, Our thoracic surgeons routinely request that continuous positive airway pressure (CPAP) be applied to the nondependent (i.e., operated on) lung either to test the bronchial staple line after resection or to ensure lung reexpansion prior to chest closure. Although we generally use low airway pressure (i.e., 15 cm H2O), at times up to 30 cm H2O is needed to expand portions of the lung that have been chronically atelectatic. Application of these pressures to both lungs may result in the relatively compliant dependent lung receiving a greater proportion of the gas flow, which can increase its risk of volutrauma. In addition, prolonged inflation with relatively high pressures can excessively increase intrathoracic pressure and even result in a mediastinal shift, each of which can reduce venous return and lead to hypotension. In order to reduce these consequences, prior to applying the CPAP, we suspend ventilation and clamp the dependent lung lumen of the double-lumen endotracheal tube, thereby stopping gas flow to that lung. This measure not only protects the dependent lung from the high airway pressures, but also reduces the duration of CPAP application by expanding the non-dependent lung more rapidly, and thus decreases the risk of prolonged reduction in venous return. Although clamping the dependent lung prior to applying CPAP to the operative lung is not a novel technique, it has come to our attention that many anesthesiologists have not considered it. Indeed, residents who have come to our hospital for exposure to community anesthesia practice frequently note that this technique has not been taught in their training programs. Also, after observing the technique, they have expressed appreciation of its advantages. A potential objection to clamping flow to the dependent lung during a CPAP test is the potential to subjecting the patient to the risk of hypoxemia or hypercapnea. We have not found this been an issue, however. If anything, oxygen saturation improves as the alveoli are opened. Also, suspending ventilation for less than the minute it usually takes to re-expand the lung is unlikely to increase CO2 to any significant degree. Importantly, we have not observed hypotension during re-inflation using this lung-clamping CPAP technique. Despite the fact that there have been no clinical studies to determine that any one technique for lung re-expansion provides better results than any other, we think that this technique is a logical and relatively safe method to prevent potential volutrauma and/or hypotension.

Effects of Different Treatments on Properties of Biogas Fermentation with Ginger Skin

In order to obtain gas potential and characteristics of ginger skin in biogas fermentation as raw material, and explore effect of different treatments on properties of biogas fermentation with ginger skin. At the temperature of 30°C, biogas fermentations with ginger skin were treated in two ways (natural decay and mixed with pig manure). Experiments were respectively set five different treatments (direct fermentation, natural decay, adding pig manure after natural decay (TS content of pig manure / TS content of ginger skin were respectively 1:1, 2:1 and 3:1)). The results showed gas potential of ginger skin and total gas production were respectively 118.08ml/gTS and 320ml, after the 11th day, the fermentation was in a serious acidification, as a result of stopping gas production. The fermentations with ginger skin which went through natural decay and adding pig manure after natural decay can both eliminate acidification which caused by use of ginger skin directly, and conduce to the fermentation with ginger skin. The fermentation with ginger skin which went through natural decay had higher degradation rate of TS, total gas production, TS gas potential and methane content than fermentation with ginger skin directly.

CODED APERTURE THERMAL NEUTRON CAMERA WITH ASIC-BASED PAD READOUT

A new generation of coded aperture neutron imagers is being developed at Brookhaven National Laboratory. The detector of the camera is a position sensitive thermal neutron chamber. The new device is a 3 He -filled ionization chamber, which uses only anode and cathode planes. The anode is composed of an array of individual pads. The charge is collected on each of the individual 5 × 5 mm2 anode pads, (48 × 48 in total corresponding to a 24 × 24 cm2 sensitive area) and read out by application specific integrated circuits. The new design has several advantages for the field of coded aperture applications compared to the previous generation of wire-grid based neutron detectors. Among these are the rugged design, lighter weight and use of non-flammable stopping gas. The pad-based readout is event by event, thus capable of high count rates, and can perform data analysis and imaging on an event by event basis. The spatial resolution of the detector can be better than the pixel size by using charge sharing between adjacent pads. In this paper, we will report on the development and performance of the new, prototype pad-based neutron camera and present the first pad-based coded aperture images of thermalized neutron sources.

First experimental results of a cryogenic stopping cell with short-lived, heavy uranium fragments produced at 1000 MeV/u

A cryogenic stopping cell (CSC) has been commissioned with 238U projectile fragments produced at 1000 MeV/u. The spatial isotopic separation in flight was performed with the FRS applying a monoenergetic degrader. For the first time, a stopping cell was operated with exotic nuclei at cryogenic temperatures (70 to 100 K). A helium stopping gas density of up to was used, about two times higher than reached before for a stopping cell with RF ion repelling structures. An overall efficiency of up to 15%, a combined ion survival and extraction efficiency of about 50%, and extraction times of 24 ms were achieved for heavy α-decaying uranium fragments. Mass spectrometry with a multiple-reflection time-of-flight mass spectrometer has demonstrated the excellent cleanliness of the CSC. This setup has opened a new field for the spectroscopy of short-lived nuclei.

STRUCTURE AND EVOLUTION OF CIRCUMBINARY DISKS AROUND SUPERMASSIVE BLACK HOLE BINARIES

It is generally believed that gaseous disks around supermassive black hole (SMBH) binaries in centers of galaxies can facilitate binary merger and give rise to observational signatures both in electromagnetic and gravitational wave domains. We explore general properties of circumbinary disks by reformulating standard equations for the viscous disk evolution in terms of the viscous angular momentum flux F_J. In steady state F_J is a linear function of the specific angular momentum, which is a generalization of (but is not equivalent to) the standard constant \dot M disk solution. If the torque produced by the central binary is effective at stopping gas inflow and opening a gap (or cavity) in the disk, then the inner part of the circumbinary disk can be approximated as a constant F_J disk. We compute properties of such disks in different physical regimes relevant for SMBH binaries and use these results to understand the gas-assisted evolution of SMBH pairs starting at separations 10^{-4}-10^{-2} pc. We find the following. (1) Pile-up of matter at the inner edge of the disk leads to continuous growth of the torque acting on the binary and can considerably accelerate its orbital evolution compared to the gravitational wave-driven decay. (2) Torque on the binary is determined non-locally and does not in general reflect the disk properties in the vicinity of the binary. (3) Binary evolution depends on the past history of the disk evolution. (4) Eddington limit can be important in circumbinary disks even if they accrete at sub-Eddington rates at late stages of binary evolution. (5) Circumbinary disk self-consistently evolved under the action of the binary torque emits more power and has spectrum different from the spectrum of constant \dot M disk - it is steeper (\nu F_\nu\propto \nu^{12/7}) and extends to shorter wavelength, facilitating its detection.