Fill Gas Research Articles

Storage Control Philosophies for Gas Filling Stations at Biogas Plants

AbstractThe production of biomethane as a fuel is an opportunity for existing combined heat and power biogas plants. These plants are not necessarily located near access points to the natural gas grid and will need to store the produced biomethane on site. Fuel demand is not constant, and the anaerobic digestion plant can vary its production, ramp up compression, and store gas pre‐compression near ambient pressure or post‐compression in high‐pressure storage tanks. Compression is an energy‐intensive process, and some of the energy is lost when a storage tank compressed to 250 bar is connected to an empty fuel tank of a vehicle (30 bar). The aim of this work was to develop a method to identify reasonable and optimal tank sizes, volume splits, and starting pressures and provide two control philosophies for the filling station.

Development and integration of photonic Doppler velocimetry as a diagnostic for radiation driven experiments on the Z-machine.

Plasma density measurements are key to a wide variety of high-energy-density (HED) and laboratory astrophysics experiments. We present a creative application of photonic Doppler velocimetry (PDV) from which time- and spatially resolved electron density measurements can be made. PDV has been implemented for the first time in close proximity, ∼6 cm, to the high-intensity radiation flux produced by a z-pinch dynamic hohlraum on the Z-machine. Multiple PDV probes were incorporated into the photoionized gas cell platform. Two probes, spaced 4 mm apart, were used to assess plasma density and uniformity in the central region of the gas cell during the formation of the plasma. Electron density time histories with subnanosecond resolution were extracted from PDV measurements taken from the gas cells fielded with neon at 15 Torr. As well, a null shot with no gas fill in the cell was fielded. A major achievement was the low noise high-quality measurements made in the harsh environment produced by the mega-joules of x-ray energy emitted at the collapse of the z-pinch implosion. To evaluate time dependent radiation induced effects in the fiber optic system, two PDV noise probes were included on either side of the gas cell. The success of this alternative use of PDV demonstrates that it is a reliable, precise, and affordable new electron density diagnostic for radiation driven experiments and more generally HED experiments.

Mathematical Modeling & Engineering Design of Wastewater Treatment Unit for Al-Kut Gas Filling Company

New talented treatment method without chemicals and with minimum operational cost was performed to treat industrial waste water discharged by a hydrostatic test performed on the gas bottles maintenance workshops to reuse it. A common method by Tarleton and Wakeman was used to select the general treatment philosophy, The implementation of this study was carried out on three stages, water sample analysis, simulates the proposed preliminary design and detailed engineering designing for the first stage, a sample of waste water was brought from Al-Kut Gas Filling Company - maintenance section and tested for settling, aeration, and filtration. The experiments showed that the most of sediments were insoluble but rather than suspended in water and can be removed by settling. Furthermore, aeration test showed that concentrated Thiophene odor in water was removed at 50 C of water with diffused air bubbling. On the other hand, filtration of using 10 Micron filter paper was achieved to eliminate the rest of tiny sedimentation. Secondly, general dimension of equipment was calculated by engineering design equation according to qualitative and quantitative analyses of waste water. Accordingly, a set of experiments of simulation using ANSYS V19.0 and Eulerian – Eulerian as mathematical model were performed for the 3D two phase flow sedimentation tank with capacity of 5 m3/hr to find the optimum sedimentation performance by testing of the modifications on the tank geometry (baffle depth, distance between baffle and inlet, hooper). Simulation results showed that the optimum tank geometry (0.86 m Baffle depth with inclined part, 2.5m distance between baffle and inlet, hooper within V type geometry W=1.67m/0.29 m, D=1.03 m and tank dimension (L=10m, W=2.5, H=2.5 with slope angle = 2o) with 49.5 volume % in sediment layer with a minimum sediment layer height. 
 The third stage included an accomplishment of the Preliminary and detailed engineering design of the entire unit by SOLIDWORKS software to be ready for prototyping.

المتكامل في تحسين تقارير الاستدامة COSO تأثير الرقابة الداخلية وفقا لإطار لشركات النفط العراقية

The orientation towards preparing sustainability reports has become an urgent necessity that economic units bear in order to provide financial and non-financial information in a concise and reliable manner in order to meet the needs of stakeholders. The research aimed to evaluate the efficiency of internal control in accordance with the COSO framework and its role in improving sustainability reports, and to achieve research and testing objectives. His hypotheses, the questionnaire form that included preparing the modified sustainability reports was designed according to the represent the dependent variable, as well as an examination form in which the extent of the reliance of the internal control of companies. (COSO) to be representative of the explanatory (i.e., independent) variable. The research sample was represented in five oil companies (Middle Oil Company, Oil Products Distribution Company, Middle Refineries Company, Oil Pipelines Company and the General Company for Gas Filling and Services). The questionnaire was distributed to officials in various centers of the above mentioned companies' departments, including the Control and Audit Department and the Financial Commission. And the production department and the environment and safety department. The research found that there is an impact of internal control mechanisms based on the principles of the (COSO) framework in improving the preparation of sustainability reports according to (COSO).

Working Posture Analysis for Skid Tank Gas Filling Process Using Nordic Body Map and Rapid Entire Body Assessment Method

Working Posture Analysis for Skid Tank Gas Filling Process Using Nordic Body Map and Rapid Entire Body Assessment Method

Evolution and successful management of a large postvitrectomy macular hole

We report the successful closure of a large postvitrectomy macular hole by temporal extension of internal limiting membrane (ILM) peeling. A 25-year-old man underwent pars plana vitrectomy, ILM peeling, and perfluoropropane gas tamponade for optic pit with chronic macular schisis and outer lamellar hole. The macular schisis deroofed into a large, full-thickness macular hole postoperatively. Optical coherence tomography revealed the horizontally oval shape of the secondary macular hole (658 × 824 μ). The best-corrected visual acuity (BCVA) was 20/200. Since ILM had already been peeled and the macular hole was widest horizontally, we combined a repeat gas tamponade with temporal extension of the ILM rhexis. Closure of the large macular hole with no central defect was observed and documented after the gas fill of the vitreous cavity was reduced sufficiently. BCVA remained unchanged for the initial months but gradually improved to 20/63 by the final follow-up visit at 5 years. A simple horizontal extension of ILM peel - in line with the shape of the hole - with repeat gas tamponade successfully closed a large secondary macular hole with progressive visual improvement.

Intellectualization of Medium Pressure Environmental Protection Gas Filling Cabinet

Intellectualization of Medium Pressure Environmental Protection Gas Filling Cabinet

Influence of metallo-dielectric optical properties on thermal resistance and solar heat gain coefficient of multi-pane glazing systems in hot and cold climates

ABSTRACT The design of efficient windows and building facades in relation to their energy-saving potentials can be developed through an advanced computational modeling analysis, and thus an effective basis of comparison of the thermal performance of glazing systems can be realized. This study simulates the behavior of window systems that integrate partitioning radiant shades, where the latter are situated between typical glass panes comprising an insulated glazing unit. The partitioning shades comprise of spectrally selective metallo-dielectric coatings that modulate optical transmittance in the visible, infrared and mid-infrared regions. Wide variety of window configurations are studied, and the results are analyzed based on the system performance criteria of thermal resistance (R-value and U-value) and solar heat gain coefficient. The comparative performance assessment of single, double, triple and quadruple ‘pane’ glazing systems in relation to internal and external environmental conditions is presented. The effects of different parameters such as fill gas, inter-pane distance, pane thickness and optical properties of coatings on thermal behavior of the fenestration system are presented. Optimal design parameters for cold and hot climates are proposed; and the results show that it is possible to reduce up to 90% heat loss in winter for the most effective configuration.

Atmospheric Photoionization Detector with Improved Photon Efficiency: A Proof of Concept for Application of a Nanolayer Thin-Film Electrode.

Atmospheric photoionization is a widely applied soft ionization mechanism in gas sensing devices for the detection of volatile organic compounds in ambient air. Photoionization is typically induced by low-pressure Vacuum Ultraviolet (VUV) lamps with MgF2 or LiF lamp surface windows depending on the gas fill and the required wavelength transmission window. These lamps are known to exhibit gradually reduced VUV transmission due to hydrocarbon contamination. LiF surface windows are known to be especially problematic due to their hygroscopic nature, reducing VUV lamp lifetime to a mere 100 h, approximately. Here, we present a new design for the electrode of a photoionization detector based on thin-film technology. By replacing the commonplace metal grid electrode’s VUV lamp surface window with a chromium/gold thin film we obtain a doubling of photon efficiency for photoionization. Replacing the hygroscopic LiF lamp window surface with a metallic layer additionally offers the possibility to vastly increase operational lifetime of low-pressure Argon VUV lamps.

Combustion Characteristics According to the Chemical Composition of Land Fill Gas

This study was conducted using the existing ignition device to verify the effectiveness of LFG, a renewable energy source. The experimental method used a constant volume combustion chamber to check the flame propagation process and combustion pressure. The experiment was carried out by changing the fuel composition ratio of LFG in the range of LFG70 to LFG40. From the result, it was found that the methane combustion occurred smoothly in LFG70 during the flame propagation process, and that combustion progressed gradually over time. In the LFG60 and LFG50 regions, which are fuels with a high CO2 ratio, it was confirmed that the combustion slowed down and the brightness of the light decreased at the same time. In LFG40 with 40% of CH4, a misfire phenomenon in which combustion does not occur was discovered. For combustion pressure, the CH4 chemical composition of the LFG was lowered, which led to the combustion delay and the reduction of combustion pressure

Modelling and performance analysis of a recuperated gas turbine with low-Btu fuel

• A gas turbine model was estabilished considering recuperator, fuel, and generator. • The recuperator is the dominant component for thermal inertia of smallgas turbine. • 1-D heat soakage model was more proper for radial rotor than 0-D lumped model. • The thermal inertia and volume effect are good for gas turbine with sudden load change. • Overspeed in load shedding and surge in deceleration need to be studied case by case. Low-Btu fuels such as land fill gas and bio-gas are good alternatives to high priced natural gas. Due to the limited production of low-Btu fuel, small gas turbines are widely applied in such applications. For higher power efficiency at full and part load conditions, the small gas turbine is always equipped with a recuperator and a high-speed generator. Due to low shaft inertia, a small gas turbine’s speed response is quick. Therefore, for standard simple cycle gas turbine, control lags from instruments, actuators, thermal inertia, or volume effect may induce control instabilities during transient loading, and resulting in over speed, flow instabilities, and even mechanical failure. However, for recuperated engine burning low BTU fuel, other factors including the large volume of the combustor and recuperator, the thermal inertia of the rotor and recuperator, lags in the fuel valve lags, and efficiency changes caused by rectifiers of the high-speed generators could all induce visible changes and lags in the engine’s transient operations. This paper summarizes the influences of the gas turbine engine itself, the recuperator, and the high-speed generator in one model. It is believed that this is the first time that all these effects and interactions have been analysed together. Heat soakage, volume dynamics, recuperator transient characteristics, and the rectifier model were combined and tuned in detail to understand the separate effects. From the analysis of transient cases such as, load shedding and acceleration, conclusions are drawn made regarding overspeed and recovery time. The recuperator thermal inertia, low-Btu fuel, and combustor and recuperator volume effect interact with each other to produce more than three times larger overspeed or nearly five times more recovery time compared to a natural gas engine with recuperator. The fuel valve with a 0.02 s-time constant was found to be adequate even for the most severe case described in this paper. The recuperated gas turbine did not necessarily lead to lower compressor surge margin and should be investigated on a case-by-case basis. Rectifier system efficiency variation should be taken into account especially for the acceleration process. To convert a natural gas turbine engine into low-Btu gas turbine, the matching point of the gas turbine components needs to be carefully selected for efficiency, surge margin, and transient manoeuvre behaviour.

A Review on Municipal Solid Waste Disposal by Sanitary Landfilling Method

Over the years, the generation of municipal waste in India has increased significantly. Solid waste management has become an important issue due to poor waste management practices affect public health and urban services. Municipal waste generation increases with increasing population, urbanization and industrialization. Municipal solid wastes disposal is a stinging and widespread problem in many developed and developing countries, in both urban and rural areas. Municipal waste management solutions must be economically sustainable, technically feasible, social, legally acceptable and environmentally friendly. Sanitary landfilling is popular in most countries because of the due to its relatively low cost and low technical requirements This paper mainly review on need to dispose of municipal waste, sanitary land filling method of disposal of MSW, Evaluation of the impact of landfills on the environment such leachate, land fill gases (LFG), land fill fires (LFF), strategies for effective management of sanitary landfills and sustainable measures (reduce, reuse and recycle) to minimize the amount of waste that ends up in landfills. Keywords: Municipal solid waste, Sanitary landfill, leachate, land fill gases (LFG) and land fill fires (LFF).

Late-onset persistent corneal hydrops after crosslinking treated with 24% C3F8

Corneal hydrops can occur in an apparently stable cornea many years after crosslinking. This case describes the management of persistent hydrops unresponsive to conservative treatment. A 31-year-old woman presented with right acute corneal hydrops 9 years after crosslinking for keratoconus. No clear precipitant was identified, and corneal topography had been stable over the past 9 years. The right cornea demonstrated inferior hydrops with gross thickening of the stroma. The hydrops persisted and failed to resolve after 6 months, despite 2 intracameral 14% C3F8 gas injections and topical hypertonic saline. An intracameral concentration of 24% C3F8, with 65% fill of the anterior chamber was performed, with the gas partially released after day 3, resulting in resolution of the hydrops. Corneal hydrops after crosslinking is a rare phenomenon, but it is likely an underreported complication. The hydrops in this case was recalcitrant to conservative measures. An expansile concentration of intracameral C3F8 was used to achieve a full gas fill to tamponade the inferior Descemet tear. Close follow-up is required to monitor for intraocular pressure spikes and perform paracentesis as required.

Achieving record hot spot energies with large HDC implosions on NIF in HYBRID-E

HYBRID-E is an inertial confinement fusion implosion design that increases energy coupled to the hot spot by increasing the capsule scale in cylindrical hohlraums while operating within the current experimental limits of the National Ignition Facility. HYBRID-E reduces the hohlraum scale at a fixed capsule size compared to previous HYBRID designs, thereby increasing the hohlraum efficiency and energy coupled to the capsule, and uses the cross-beam energy transfer (CBET) to control the implosion symmetry by operating the inner (23° and 30°) and outer (44° and 50°) laser beams at different wavelengths (Δλ> 0). Small case to capsule ratio designs can suffer from insufficient drive at the waist of the hohlraum. We show that only a small amount of wavelength separation between the inner and outer beams (Δλ 1–2 Å) is required to control the symmetry in low-gas-filled hohlraums (0.3 mg/cm3 He) with enough drive at the waist of the hohlraum to symmetrically drive capsules 1180 μm in outer radius. This campaign is the first to use the CBET to control the symmetry in 0.3 mg/cm3 He-filled hohlraums, the lowest gas fill density yet fielded with Δλ> 0. We find a stronger sensitivity of hot spot P2 in μm per Angstrom (40–50 μm/Å wavelength separation) than observed in high-gas-filled hohlraums and previous longer pulse designs that used a hohlraum gas fill density of 0.6 mg/cm3. There is currently no indication of transfer roll-off with increasing Δλ, indicating that even longer pulses or larger capsules could be driven using the CBET in cylindrical hohlraums. We show that the radiation flux symmetry is well controlled during the foot of the pulse, and that the entire implosion can be tuned symmetrically in the presence of the CBET in this system, with low levels of laser backscatter out of the hohlraum and low levels of hot electron production from intense laser–plasma interactions. Radiation hydrodynamic simulations can accurately represent the early shock symmetry and be used as a design tool, but cannot predict the late-time radiation flux symmetry during the peak of the pulse, and semi-empirical models are used to design the experiments. Deuterium–tritium (DT)-layered tests of 1100 μm inner radius implosions showed performance close to expectations from simulations at velocities up to ∼360 km/s, and record yields at this velocity, when increasing the DT fuel layer thickness to mitigate hydrodynamic mixing of the ablator into the hot spot as a result of defects in the ablator. However, when the implosion velocity was increased, mixing due to these defects impacted performance. The ratio of measured to simulated yield for these experiments was directly correlated with the level of observed mixing. These simulations suggest that reducing the mixing, e.g., by improving the capsule defects, could result in higher performance. In addition, future experiments are planned to reduce the coast time at this scale, delay between the peak compression and the end of the laser, to increase the hot spot convergence and pressure. To reduce the coast time by several hundred ps compared to the 1100 μm inner radius implosions, HYBRID-E has also fielded 1050 μm inner radius capsules, which resulted in higher hot spot pressure and a fusion energy yield of ∼170 kJ.

Initial and volume recombination losses in gamma versatile ionization chamber VGIC for gamma ray dosimetry

A versatile gamma ionization chamber (VGIC) has been designed, developed and characterized, in order to study experimentally its characteristics according to the geometry of the electrodes, the volume and pressure of the filler gas for the design of a gamma sealed chamber. The tests were conducted under the IEC (International Electro-technical Commission). The results obtained in various nuclear tests of the characterization and calibration of the ionization chamber gamma VGIC developed at our laboratory were presented in this paper. Three irradiators were operated, irradiator intensive gamma (60Co: 1.25 MeV), medium intensive gamma (137Cs: 0.662 MeV) and low-intensity gamma (60Co). Saturation curves and linearity were identified and the operating range and the sensitivity of the chamber have been deducted. The current, voltage (I,V) characteristics of the chamber filled, with argon gas at 0.4 M pa pressure, for gamma ray irradiator sources were studied, the chamber was irradiated with gamma rays using different gamma sources. The plateau region is reached above 200 V and the detector operating voltage is found to be 600V. It is observed that in the plateau region the slope is constant with an increase in the exposure rate. The (1/I, 1/V) and (I, l/V2) characteristic curves reveal the presence of the initial and volume recombination losses. The volume recombination losses are found to be smaller than the initial recombination losses.

Two-Dimensional Gallium Sulfide Nanoflakes for UV-Selective Photoelectrochemical-type Photodetectors.

Two-dimensional (2D) transition-metal monochalcogenides have been recently predicted to be potential photo(electro)catalysts for water splitting and photoelectrochemical (PEC) reactions. Differently from the most established InSe, GaSe, GeSe, and many other monochalcogenides, bulk GaS has a large band gap of ∼2.5 eV, which increases up to more than 3.0 eV with decreasing its thickness due to quantum confinement effects. Therefore, 2D GaS fills the void between 2D small-band-gap semiconductors and insulators, resulting of interest for the realization of van der Waals type-I heterojunctions in photocatalysis, as well as the development of UV light-emitting diodes, quantum wells, and other optoelectronic devices. Based on theoretical calculations of the electronic structure of GaS as a function of layer number reported in the literature, we experimentally demonstrate, for the first time, the PEC properties of liquid-phase exfoliated GaS nanoflakes. Our results indicate that solution-processed 2D GaS-based PEC-type photodetectors outperform the corresponding solid-state photodetectors. In fact, the 2D morphology of the GaS flakes intrinsically minimizes the distance between the photogenerated charges and the surface area at which the redox reactions occur, limiting electron–hole recombination losses. The latter are instead deleterious for standard solid-state configurations. Consequently, PEC-type 2D GaS photodetectors display a relevant UV-selective photoresponse. In particular, they attain responsivities of 1.8 mA W–1 in 1 M H2SO4 [at 0.8 V vs reversible hydrogen electrode (RHE)], 4.6 mA W–1 in 1 M Na2SO4 (at 0.9 V vs RHE), and 6.8 mA W–1 in 1 M KOH (at 1.1. V vs RHE) under 275 nm illumination wavelength with an intensity of 1.3 mW cm–2. Beyond the photodetector application, 2D GaS-based PEC-type devices may find application in tandem solar PEC cells in combination with other visible-sensitive low-band-gap materials, including transition-metal monochalcogenides recently established for PEC solar energy conversion applications.

Development of a 3He Gas Filling Station at the China Spallation Neutron SourceSupported by the National Key Research and Development Program of China (Grant No. 2020YFA0406000), the Scientific Instrument Development Project of the Chinese Academy of Sciences (Grant No. 284(2018)), and the National Natural Science Foundation of China (Grant No. 11875265).

At the China Spallation Neutron Source (CSNS), we have developed a custom gas-filling station, a glassblowing workshop, and a spin-exchange optical pumping (SEOP) system for producing high-quality 3He-based neutron spin filter (NSF) cells. The gas-filling station is capable of routinely filling 3He cells made from GE180 glass of various dimensions, to be used as neutron polarizers and analyzers on beamlines at the CSNS. Performance tests on cells fabricated at our gas-filling station are conducted via neutron transmission and nuclear-magnetic-resonance measurements, revealing nominal filling pressures, and a saturated 3He polarization in the region of 80%, with a lifetime of approximately 240 hours. These results demonstrate our ability to produce competitive NSF cells to meet the ever-increasing research needs of the polarized neutron research community.

Optimization and Experimental Validation of Automotive Bulbs

In a vehicle, bulbs called the P-group are responsible for warning other drivers or pedestrians and they are known as signal bulbs. Signal bulbs have been used to emit warning and hazard signs in parts such as brake lights, direction indicator, hazard lights (night vision) as well as tail bulbs and car park alarms. There has been limited researches on the photometric characteristics of these lamps, but a review of these studies revealed that no detailed research has yet been done on optimizing these characteristics, and there is a scientific gap. In this study, factors affecting the service life and luminous flux were evaluated by using Taguchi design of experiments method. The results showed that the two factors of weight percent composition of bubble filling neutral gases and the volumetric efficiency of gases injected into the bubble had the most influence on the target parameters. Experimental results showed that the optimum composition of neutral gases injected into the bulb bubble can extend the bulb service life to approximately 341 h, which is three times the service life of a bulb with the inappropriate composition of fill gases. Then the optimum state of the service life and the luminous flux were determined to meet the reference standards. Although the service life and luminous flux parameters were able to reach 341 h and 513 lumens in the maximized state, however, in the optimum state with satisfying reference standards, the service life and luminous flux were 330 h and 463 lumens, respectively. Then, the bulb bubble filling with inert neutral gases and its effect on the bulb service life was investigated. The results showed that if the volumetric efficiency of gas injection increased from the normal 75%–100%, the service life of the test lamps would be improved by about 10%.

Developing "inverted-corona" fusion targets as high-fluence neutron sources.

We present experimental studies of inverted-corona targets as neutron sources at the OMEGA Laser Facility and the National Ignition Facility (NIF). Laser beams are directed onto the inner walls of a capsule via laser-entrance holes (LEHs), heating the target interior to fusion conditions. The fusion fuel is provided either as a wall liner, e.g., deuterated plastic (CD), or as a gas fill, e.g., D2 gas. Such targets are robust to low-mode drive asymmetries, allowing for single-sided laser drive. On OMEGA, 1.8-mm-diameter targets with either a 10-μm CD liner or up to 2 atm of D2-gas fill were driven with up to 18 kJ of laser energy in a 1-ns square pulse. Neutron yields of up to 1.5 × 1010 generally followed expected trends with fill pressure or laser energy, although the data imply some mix of the CH wall into the fusion fuel for either design. Comparable performance was observed with single-sided (1x LEH) or double-sided (2x LEH) drive. NIF experiments tested the platform at scaled up dimensions and energies, combining a 15-μm CD liner and a 3-atm D2-gas fill in a 4.5-mm diameter target, laser-driven with up to 330 kJ. Neutron yields up to 2.6 × 1012 were measured, exceeding the scaled yield expectation from the OMEGA data. The observed energy scaling on the NIF implies that the neutron production is gas dominated, suggesting a performance boost from using deuterium-tritium (DT) gas. We estimate that neutron yields exceeding 1014 should be readily achievable using a modest laser drive of ∼300 kJ with a DT fill.

Radiation hydrodynamical self-similar funnel jets

ABSTRACT Two-dimensional funnel flows driven by radiation pressure in the conical funnel formed by the critical accretion disc are examined using the self-similar treatment. The flow is assumed to be steady and axisymmetric, and other forces such as viscosity and magnetic fields are ignored. For various boundary conditions on the funnel wall at the disc surface, the self-similar solutions are found to be classified into three types: funnel-filled solutions, where the flow gas fills the whole region of the funnel; polar-hollow ones, where there appears a cavity around the polar axis, and unphysical ones in a sense that, e.g. the radiation energy density becomes negative. For the physically reasonable solutions, the flow gas generally concentrates to the funnel wall, and the flow density and the radiation energy density monotonically decrease from the funnel wall towards the polar axis, while the radial flux becomes negative near the polar axis. The vertical velocity increases towards the polar axis, while the vertical flux has often the maximum between the polar axis and the funnel wall. As a result, the present self-similar funnel jets are such a flow with a slow dense outer part and a fast rarefied inner part.