Gas Volume Research Articles

Gas and energy security in Germany and central and Eastern Europe

Russia's weaponization of gas supplies caused a shock to the energy security of Central and Eastern Europe in 2022. Countries responded by increasing alternative energy supplies and developing new natural gas supply routes, namely through increased LNG import capacity and new interconnectors. At the same time, market forces in the form of higher prices largely ensured an efficient allocation of scarce gas across the region and encouraged the necessary savings. We examine how gas flows to and within the region have been changing in the short- and medium-term and explore the role of renewable and nuclear energy as well as hydrogen in the long-term. We conclude that mitigating the effects of this shock requires the EU to prioritize policies that foster the integrity of its energy market. Government policies and higher fossil fuel prices will encourage the build-up of renewables, increasing energy security medium term. Only in combination with consistently high energy savings and the procurement and distribution of sufficient gas volumes from the global LNG market can Russian supplies be replaced. It is thus the interplay of supply and demand measures that allowed Central and Eastern Europe to withstand the extraordinary shock of 2022.

Rancang Bangun Sistem Monitoring Kebocoran Gas, Suhu, dan Kelembapan pada Dapur Berbasis Internet of Things Menggunakan Mikrokontroler Wemos D1 Mini

This research is about the design of a gas leak monitoring system, temperature, and humidity in an Internet of Things (IoT) based kitchen using a Wemos D1 Mini microcontroller. The system aims to overcome the problem of uncontrolled temperature and humidity that affect the quality of food, as well as the high risk of LPG gas explosion due to leakage. A gas leak monitoring system using MQ2 sensor, monitoring temperature and humidity values using DHT 11 sensor and microcontroller using Wemos D1 Mini. The MQ2 sensor will detect a gas leak from the volume of gas in the room. If the gas value in the room is 300 ppm, the buzzer will sound. The DHT 11 sensor will monitor the temperature and humidity percentage. Then the Wemos d1 mini will send the value to the BLYNK database and will be displayed in the application using Kodular. This research is expected to contribute to the field of IoT-based monitoring systems, improving the safety and comfort of the kitchen environment.

A Dual Mode Ultrasonic Method for Measuring Gas Volume Fraction in Two-Phase Slug Flows

A Dual Mode Ultrasonic Method for Measuring Gas Volume Fraction in Two-Phase Slug Flows

Why we should care about gas pockets in online adaptive MRgRT: a dosimetric evaluation.

Contouring of gas pockets is a time consuming step in the workflow of adaptive radiotherapy. We would like to better understand which gas pockets electronic densitiy should be used and the dosimetric impact on adaptive MRgRT treatment. 21 CT scans of patients undergoing SBRT were retrospectively evaluated. Anatomical structures were contoured: Gross Tumour Volume (GTV), stomach (ST), small bowel (SB), large bowel (LB), gas pockets (GAS) and gas in each organ respectively STG, SBG, LBG. Average HU in GAS was converted in RED, the obtained value has been named as Gastrointestinal Gas RED (GIGED). Differences of average HU in GAS, STG, SBG and LBG were computed. Three treatment plans were calculated editing the GAS volume RED that was overwritten with: air RED (0.0012), water RED (1.000), GIGED, generating respectively APLAN, WPLAN and the GPLAN. 2-D dose distributions were analyzed by gamma analysis. Parameter called active gas volume (AGV) was calculated as the intersection of GAS with the isodose of 5% of prescription dose. Average HU value contained in GAS results to be equal to -620. No significative difference was noted between the average HU of gas in different organ at risk. Value of Gamma Passing Rate (GPR) anticorrelates with the AGV for each plan comparison and the threshold value for GPR to fall below 90% is 41, 60 and 139 cc for WPLANvsAPLAN, GPLANvsAPLAN and WPLANvsGPLAN respectively. GIGED is the right RED for Gastrointestinal Gas. Novel AGV is a useful parameter to evaluate the effect of gas pocket on dose distribution.

Partial Differentiation and the Coefficient of Thermal Expansion: A Multivariable Calculus Activity Connecting with Chemistry

We describe the components and implementation of an activity for multivariable calculus featuring applications to the field of chemistry. This activity focuses on the isobaric thermal expansion coefficient found using partial differentiation of the volume of an ideal gas with respect to temperature as pressure is held constant. Broader goals of this activity include enhancing calculus conceptual understanding, encouraging further interdisciplinary study and exploration, and cultivating mathematicians and scientists with broader and deeper backgrounds.

Direct numerical simulation of bubble collision, bounce and coalescence in bubble-induced turbulence

A direct numerical simulation study has been carried out to better understand the dynamics of deformable bubbles in bubble-induced turbulence. A mathematical model for bubble collision, bounce and coalescence is developed based on the Volume-of-Fluid (VoF) method. A surface-tension-holding film thickness δc is introduced to determine whether the bubbles will coalesce or bounce after collision. Bubbly flows with the gas volume fractions αg=5.6% (low), 11.2% (medium) and 22.1% (high) are considered in the study. The DNS results show that the dissipation of turbulent kinetic energy in the cases under consideration takes place when the wavenumber κ is smaller than twice the wavenumber for the bubble diameter 2κd. The bubble-induced turbulence is anisotropic at the length scales close to the bubble diameter due to the elongated turbulent structures in the bubble-rising direction. The bubbles collide intensively with each other when they are in a cluster surrounded by the liquid with low pressure. Parallel clustering of bubbles is found when the gas volume fraction has a low or medium value. Three-dimensional clustering is found when the bubbles are densely populated. Two different mechanisms of bubble collision have been identified from the DNS results, termed parallel collision and vertical collision. Parallel collision is often observed when bubbles are sparsely populated. In a parallel collision, the relative velocity of the bubbles slows down as two bubbles approach each other due to the jet flow between them, while the relative velocity increases sharply after the bounce. In a vertical collision, by contrast, the relative velocity of bubbles accelerates as two bubbles approach each other, while it slows down during the collision. Vertical collisions occur when the bubbles are more densely populated. The numerical results also show the significant effects of δc on bubble coalescence.

Analysis of different Explosive substance

Explosive wing: An explosion is a chemical reaction which is basically exothermic in nature, the products get heated up to extremely high temperature and exert high pressure that shatters the confining walls. The explosion reactions are rapid, and are associated with oxidation reaction. Releasing heat, light and large volume of gas. Explosive material: Consists of chemical compounds or their mixture which when subjected to sudden shock (mechanical or thermal) get oxidised, Releases huge amount of energy in a extremely short period of time (which can be observed in the form of explosion)

Effect of Postoperative Trendelenburg Positioning in Reducing Shoulder Pain after Laparoscopic Cholecystectomy

Background and Objective: Shoulder pain is one of the most common complaints of patients after laparoscopic cholecystectomy, which seems to be closely related to the residual volume of carbon dioxide gas used during surgery. Therefore, this study was conducted with the aim of investigating the effect of Trendelenburg positioning after surgery in reducing shoulder pain in patients. Materials and Methods: This study was conducted as a randomized clinical trial in 58 patients who were eligible for laparoscopic cholecystectomy. Patients were enrolled in the study by simple random sampling and randomly assigned to supine (control) and Trendelenburg (intervention) positions. After complete awakening in the recovery room, the patients in the intervention group were placed in the Trendelenburg position (30 degrees), while the patients in the control group were placed in the supine position for 30 minutes. The level of pain was measured 6, 12, 24and 48 hours after completion of the procedure using the NRS scale. Data analysis was performed using SPSS version 24 software. Results: The results of this study show that there is a significant difference between the pain intensity 6, 12, 24and 48 hours after the end of the intervention between the two intervention and control groups (P >0.05). The pain in the intervention group is therefore lower than in the control group. Conclusion: As a simpleeffective, and inexpensive technique, the Trendelenburg position can reduce shoulder pain in patients undergoing laparoscopic cholecystectomy

Multi-criteria site selection workflow for geological storage of hydrogen in depleted gas fields: A case for the UK

Underground hydrogen storage (UHS) plays a critical role in ensuring the stability and security of the future clean energy supply. However, the efficiency and reliability of UHS technology depend heavily on the careful and criteria-driven selection of suitable storage sites. This study presents a hybrid multi-criteria decision-making framework integrating the Analytical Hierarchy Process (AHP) and Preference Ranking Organisation Method for Enrichment of Evaluations (PROMETHEE) to identify and select the best hydrogen storage sites among depleted gas reservoirs in the UK. To achieve this, a new set of site selection criteria is proposed in light of the technical and economic aspects of UHS, including location, reservoir rock quality and tectonic characteristics, maximum achievable hydrogen well deliverability rate, working gas capacity, cushion gas volume requirement, distance to future potential hydrogen clusters, and access to intermittent renewable energy sources (RESs). The framework is implemented to rank 71 reservoirs based on their potential and suitability for UHS. Firstly, the reservoirs are thoroughly evaluated for each proposed criterion and then the AHP-PROMETHEE technique is employed to prioritise the criteria and rank the storage sites. The study reveals that the total calculated working gas capacity based on single-well plateau withdrawal rates is around 881 TWh across all evaluated reservoirs. The maximum well deliverability rates for hydrogen withdrawal are found to vary considerably among the sites; however, 22 % are estimated to have deliverability rates exceeding 100 sm3/d, and 63 % are located within a distance of 100 km from a major hydrogen cluster. Moreover, 70 % have access to nearby RESs developments, with an estimated cumulative RESs capacity of approximately 181 GW. The results highlight the efficacy of the proposed multi-criteria site selection framework. The top five highest-ranked sites for UHS based on the evaluated criteria are the Cygnus, Hamilton, Saltfleetby, Corvette, and Hatfield Moors gas fields. The insights provided by this study can contribute to informed decision-making, sustainable development, and the overall progress of future UHS projects within the UK and globally.

A Pragmatic Approach to the Economic Assessment of Green Synthetic Methane Power in the Baltics

The synthesis of methane from hydrogen and carbon dioxide creates an energy resource that is suitable for long-term storage. Once this process is powered by renewable electricity, it produces a clean fuel for producing electricity and heat and supports large-scale renewable energy deployment, energy transition and climate change mitigation. This paper proposes a pragmatic approach to assessing the economic potential of synthetic methane-based power. Today, natural gas plays an important role in the Baltic region due to the existing infrastructure, which includes a transmission and distribution pipeline network, gas power plants and a large underground storage reservoir. Replacing natural gas with synthetic methane would fulfil carbon emission reduction ambitions. In this paper, we simulate electricity producers’ actions at market conditions and consider the generation portfolio in the Baltics and the interconnections with Scandinavia and Poland operating in the NORDPOOL electricity market. As a result of these calculations, we obtain the volume of the synthetic gas, the production costs, the volume of gas storage, the installed capacity of the gas power plant, and the investments required to ensure energy transition and system adequacy. These results are essential for the informed decisions made by policymakers, investors and system operators.

Harvesting of Dunaliella salina using electrocoagulation with helix electrode and producing HHO gas as promising Hydrogen fuel

<p>Biofuels obtained from renewable sources are the only alternative in the global economy from a sustainable point of view. Microalgae have shown tremendous potential as a major source of biomass production that can be used as biofuels. At the same time, gas hydrogen is a non-polluting energy source because it is produced from renewable sources. This study aims to analyze the harvesting efficiency of Dunaliella salina using electrocoagulation with a helix electrode and having HHO gas as hydrogen fuel. D salina harvesting using an EC reactor made of acrylic is done on a batch scale. Helix-shaped type 304 stainless steel is the cathode, and solid cylindrically-shaped Fe is the anode. The voltage set is 20 Volts, while the electrolysis time is varied between 1. 5. 10. 15. 20. 25 and 30 minutes. The harvesting efficiency of D salina using electrocoagulation with a helix electrode was the highest at 84.74%. The highest concentration of dissolved hydrogen gas was 1.753 ppm. The highest volume of HHO gas was 1978 mL resulting from a 30-minute electrocoagulation with a helix electrode, 20-volt voltage. Nanoscale glovaries are formed on the electrode through heterogeneous nucleation at the solid-liquid interface. After nucleation, the nanobubbles grow, and the buoyancy forces of the growing bubbles cause gas release from the cathode surface. This process continues until it causes many bubbles to produce 1978 mL HHO gas for 30 minutes. During the study, the convex HHO gas formed helped remove coagulated D salina floc through electro-flotation. When the time of D salina harvesting using electrocoagulation with a helix electrode significantly affects D salina harvesting efficiency, gas HHO volume, pH, and temperature, harvesting time has no significant effect on dissolved hydrogen gas concentration and ORP.</p>

A study for hydrogen evolution on Pt–MnCu electrocatalyst

Electrocatalysts to be used in electrolysis, which is one of the hydrogen production methods, are very important. The development of electrocatalysts is related to the internal structure of combinated more than one metal. In the present work, the graphite substrate is coated with manganez (C/Mn), manganez-copper (C/MnCu) and this surface is modified with platinum nanoparticles (C/MnCu–Pt) using the electrodeposition method. Prepared electrocatalysts are used for characterization, hydrogen evolution reaction (HER) and stability using cyclic voltammetry (CV), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), cathodic current-potential curves, electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA). Hydrogen gas is measured in a basic environment by establishing an experimental electrolysis setup on these electrocatalysts. Results showed that binary MnCu enhances the characteristic current density of Tafel curves, reduces the polarization resistance and enhances the hydrogen gas volume compared to graphite substrate and single Mn coating. Apart from that, much more effective results are obtained on the C/MnCu–Pt electrocatalyst. Namely, a very high exchange current density (io = 5.50 mA cm−2), a very low polarization resistance (3.2 Ω cm2) and a very low overpotential (50 mV) at 10 mA cm−2 are obtained on the C/MnCu–Pt electrocatalyst. In addition to high performance, C/MnCu–Pt electrocatalyst exhibits good stability in alkaline medium.

PSXII-27 Effect of Feed Additives in the Production of Greenhouse Gases

Abstract The mitigation of greenhouse gases is a strong trend in promoting the intensification of ruminant production through greater efficiency in the use of dietary energy. The objective of this study was to evaluate the effects of the inclusion of the NC Conf Engorda Greentech mineral mixture containing feed additives to replace the regular mineral mixture in corn-based substrates on the production of gases and methane. The experiment was carried out under anaerobic conditions using ANKOM Gas Pressure Monitor bottles at 39 ºC containing artificial saliva, ruminal fluid, and two grams of substrates from each treatment: (MI) Control, 1.62 g of corn and 0.38 g of mixture mineral; and (MM) 1.28 g of corn and 0.72 g of NC Conf Engorda Greentech (Suplemento Nutrição Animal) containing 0.326% of glucomannans, 0.253% of mannans, 0.200% monensin and 1x106· kg-1 UFC of Saccharomyces cerevisiae. Duplicate substrates and duplicate blanks were fermented for each treatment in two runs, with a total of four repetitions per treatment. The accumulated pressure resulting from the fermentation was measured automatically over 48 h using the Gas Monitor software connected to the ANKOM modules of each bottle. The conversion of pressure to gas volume was calculated as follows: Volume (mL) = 2.3932 + 3.4053 × pressure (R2 = 0.9146; n = 1.151). At the end of each run, a gas sample was collected from each bottle to measure methane concentration using gas chromatography. To obtain the methane production for every 100 mL of gas produced, the total volume of methane produced was multiplied by 100 and divided by the total gas production. Data were analyzed in a completely randomized design using analysis of variance (ANOVA) at α = 0.05. There was a 24.53% decrease in the total gas production in the MM treatment (64.79 mL) compared with the MI substrate (48.90 mL; P = 0.0084; Table 1). Methane production decreased from 46.5 to 14.91 mL in the presence of MM (P < 0.001). A reduction from 71.96 to 30.59 mL of methane was observed for every 100 mL of gas produced when feed additives were included (P < 0.001). The Saccharomyces cerevisiae strain is a precursor of mannans, which, like glucomannans, acts as a prebiotic, and together with monensin, influences the selection of the ruminal microbiota and modifies the volatile fatty acid profile, increasing the molar proportion of propionate, and consequently reducing methane production. The addition of the NC Conf Engorda Greentech mineral mixture with glucomannans, mannans, monensin, and Saccharomyces cerevisiae decreased the production of gases and methane in a corn-based substrate.

PSXIII-23 Effect of Methionine Inclusion in Mineral Mixture on Greenhouse Gas Production

Abstract The reduction in enteric methane production in cattle can have a rapid impact on global warming. Therefore, changes in the population of microorganisms in the rumen can significantly reduce the production of this greenhouse gas. This in vitro study aimed to evaluate the production of gases and methane with the inclusion of Suplemax mineral mixture containing methionine. The experiment was carried out under anaerobic conditions using ANKOM Gas Pressure Monitor bottles kept at 39 ºC containing artificial saliva, ruminal fluid, and two grams of a substrate from each treatment: (FE) Control, 1.75 g of Tifton hay 85 and 0.25 g of a mineral mix; and (FM) 1.75 g of hay and 0.25 g of Suplemax mineral mixture (Suplemento Nutrição Animal) containing 0.3% of methionine. Duplicate substrates and duplicate blanks were fermented for each treatment in two runs, with a total of four repetitions per treatment. The accumulated pressure resulting from the fermentation was measured automatically over 48 h using the Gas Monitor software connected to the ANKOM modules of each bottle. The conversion of pressure to gas volume was calculated as follows: Volume (mL) = 2.3932 + 3.4053 × pressure (R2 = 0.9146; n = 1.151). At the end of each run, a gas sample was collected from each bottle to measure methane concentration using gas chromatography. To obtain the methane production for every 100 mL of gas produced, the total volume of methane produced was multiplied by 100 and divided by the total gas production. Data were analyzed in a completely randomized design using analysis of variance (ANOVA) at α = 0.05. There was no significant effect on gas production with the inclusion of 0,3% of methionine (FE 37.77 mL vs FM 42.54 mL, P = 0.3175; Table 1). Methane production decreased from 22.74 to 18.15 mL (P = 0.0121) in the FM treatment compared with the FE treatment, representing a 20.18% decrease. Methane production for every 100 mL of gas decreased by 31.08% with the inclusion of methionine (FE 61.62 vs FM 42.47 mL, P = 0.0248). The inclusion of methionine in the mineral supplement contributes to a change in the molar proportion of short-chain fatty acids, increasing propiogenesis, that is considered a sink of hydrogen ions in the ruminal environment, which in turn inhibits methane production. Thus, the inclusion of Suplemax with hay reduced gas and methane production in vitro.

PSVII-30 Effect of mineral mixture containing HMTBa in hay-based substrate on methane production.

Abstract In grazing systems, cattle produce a high molar ratio of acetate, resulting in greater methane production and greater energy loss via gas production. Thus, the objective of this study was to evaluate in vitro gas production and methane concentration using a mineral mixture containing 0.4% HMTBa in a Tifton hay-based substrate. The experiment was carried out under anaerobic conditions using ANKOM Gas Pressure Monitor bottles kept at 39 ºC containing artificial saliva, ruminal fluid, and two grams of a substrate from each treatment: (FE) Control, 1.75 g of Tifton hay and 0.25 g of mineral mixture; and (FM) 1.75 g of Tifton hay and 0.25 g of Suplemax mineral mixture (Suplemento Nutrição Animal) containing 0.4% of HMTBa. Duplicate substrates and duplicate blanks were fermented for each treatment in two runs, with a total of four repetitions per treatment. The accumulated pressure resulting from the fermentation was measured automatically over 48 hours using the Gas Monitor software connected to the ANKOM modules of each bottle. The conversion of pressure to gas volume was calculated as follows: Volume (mL) = 2.3932 + 3.4053 × pressure (R2 = 0.9146; n = 1.151). At the end of each run, a gas sample was collected from each bottle to measure methane concentration using gas chromatography. To obtain the methane production for every 100 mL of gas produced, the total volume of methane produced was multiplied by 100 and divided by the total gas production. Data were analyzed in a completely randomized design using analysis of variance (ANOVA) at α = 0.05. Gas production was not affected by the inclusion of HMTBa (P = 0.3938), with an average of 54.14 mL (Table 1). There was a reduction in methane production from 25.41 to 20.05 mL with the addition of HMTBa (P = 0.0034), representing a decrease of 21.09%. There was a tendency to reduce methane production for each 100 mL of gas produced from 46.01 to 37.86 mL (P = 0.0889). Although HMTBa reduces the molar proportion of propionate, it is considered to be one of the main hydrogen users. In environments with a high concentration of H2 (above 1 mmol) and the presence of an anti-methanogen, the most favored path for using hydrogen is acetogenesis, which reduces methane production. Thus, the use of a mineral mixture containing 0.4% HMTBa in a Tifton-hay-based substrate reduced methane production in an in vitro assay.

PSXIII-24 Effect of Inclusion of Hay and Concentrate Containing Monensin and Methionine on in Vitro Methane Production

Abstract The objective of this study was to evaluate the effect of the inclusion of hay and Suplemento Total concentrate as a substitute for corn on gas production and methane concentration in vitro. The experiment was conducted under anaerobic conditions using bottles that simulate the ruminal environment (ANKOM Gas Pressure Monitor) containing artificial saliva, rumen liquid, and two g of substrates from each treatment: (MI) Control, 1.62 g of corn containing 9% of crude protein and 0.38 g of mineral mix and; (FMM) 1.02 g of Tifton 85 hay and 0.98 g of Suplemento Total concentrate (Suplemento Nutrição Animal) containing 13.5% of crude protein, 0.32% of monensin and 0.63% of methionine. Duplicate substrates and duplicate blanks were fermented for each treatment in two runs, with a total of four repetitions per treatment. The accumulated pressure resulting from the fermentation was measured automatically over 48 h using the Gas Monitor software connected to the ANKOM modules of each bottle. The conversion of the pressure to gas volume was calculated as follows: Volume (mL) = 2.3932 + 3.4053 × pressure (R2 = 0.9146; n = 1.151). At the end of each run, a gas sample was collected from each bottle to measure methane concentration using gas chromatography. To obtain the methane production for every 100 mL of gas produced, the total volume of methane produced was multiplied by 100 and divided by the total gas production. Data were analyzed in a completely randomized design using analysis of variance (ANOVA) at α = 0.05. Was observed 23.86% of increase in gas production (64.79 vs 80.25 mL, P = 0.0072), 45.53% reduction in total methane production (46.50 vs 25.33 mL, P < 0.001), and 56.07% reduction in methane production for every 100 mL of gas produced (71.96 vs 31.61 mL, P < 0.001) in the FMM treatment compared with the MM, respectively (Table 1). Improvement in the quality of the diet, as well as the use of monensin and methionine, increases the fermentation rate, which explains the increase in gas production. Linked to this, there is also a reduction in methane production by reducing the population of gram-positive bacteria, which are precursors of methanogenesis. Therefore, the inclusion of hay and Suplemento Total concentrate containing 0.32 percent of monensin and 0.63 percent of methionine in place of corn with mineral mixture increased gas production and reduced methane production in vitro.

Organosilicon-Based Thin Film Formation in Very High-Frequency Plasma Under Atmospheric Pressure

Owing to recent interest in the production of flexible devices, it is necessary to develop a more convenient approach in which silicon (Si) thin film transistors (TFTs) are fabricated directly onto the flexible substrates at low substrate temperatures. Unfortunately, the physical limitations of conventional plasma-enhanced chemical vapor deposition (PECVD) under low pressures becomes a critical obstacle. In this study, Si film deposition using PECVD under atmospheric pressure excited by very high-frequency electrical power was investigated to overcome this issue. Tetramethylsilane [Si(CH3)4] is used as a source gas that is much safer than silane (SiH4) gas. We investigated the effects of the reactive gas concentration and specific energy (the ratio of input power to unit volume of the reaction gas) on carbon incorporation into the resultant films. Based on the results, we discuss the possibility of forming Si films with sufficiently low carbon content, which is applicable to Si TFTs.

Enhanced flame‐retardant performance of rigid polyurethane foam by using APTES‐MMT and ATH mixed intumescent coatings

AbstractThe design of environment‐friendly fireproof rigid polyurethane foams (RPUFs) that completely prevent ignition or the spread of fires is important for energy conservation and emission reductions. In this paper, an intumescent flame‐retardant coating was prepared and coated onto the surface of a RPUF to improve its flame retardancy. Vertical combustion experiments (UL‐94) showed that, compared with the pure RPUF, a RPUF coated with the expansion coating successfully self‐extinguished without a droplet formed after ignitor removal. Thermogravimetric analyses showed that the expanded coating effectively increased the rate of carbon residue formation. Cone calorimetry showed that when the pigment‐to‐binder ratio was 3.5:1, with 5% modified montmorillonite, 6% aluminum hydroxide, and 4% titanium dioxide, the intumescent coating effectively reduced the heat release rate and total heat release of the RPUF. Remarkably, the smoke release rate and total exhaust gas volume showed that the expanded coating provided obviously enhanced smoke suppression. Therefore, the flame retardancy and toxic smoke suppression provided by the RPUF thermal insulation material is essential and very useful for healthy development of human society and the environment.

Chronic Sacral Nerve Stimulation Inhibits Visceral Hypersensitivity in Diarrhea–Predominant Irritable Bowel Syndrome Rats Model

ObjectiveSacral nerve stimulation (SNS) is emerging as a novel treatment for irritable bowel syndrome (IBS). However, its effects are limited, and the underlying mechanisms remain largely unknown. Materials and MethodsIn this study, rats were divided into three groups (n = 12 rats per group): 1) the SNS group; 2) the sham SNS group (the sham group for short); and 3) the control group. The SNS and sham groups were exposed to chronic and acute stress to establish an IBS model. Electrode implantation surgery was performed in rats with the IBS model. The SNS group received electrical stimulation for 30 minutes every day for seven days. Abdominal withdrawal reflex (AWR) was used to evaluate the effect of SNS on visceral sensitivity in diarrhea-predominant IBS (IBS-D) rats. The frequency domain of heart rate variability (HRV) was analyzed to assess the effect of SNS on regulating the autonomic function. The expression of transient receptor potential vanilloid 1 (TRPV1) in the colon, spinal cord, and hippocampus was detected by immunohistochemistry to explore the mechanism of SNS in IBS-D rats. ResultsCompared with the sham group, AWR scores were significantly decreased under different gas volumes of stimulation of 0.4, 0.6, and 0.8 ml for rectal distention in the SNS group (all p < 0.05). However, there was no significant difference <1.0 ml between the two groups (p > 0.05). Compared with the sham group, the frequency domain indexes of HRV were significantly altered. Normalized low-frequency power and low frequency-to-high frequency ratio were significantly decreased, and normalized high-frequency power was significantly increased in the SNS group (all p < 0.05). Moreover, the expression of TRPV1 in the spinal cord and colon in the SNS group was significantly decreased compared with the sham group (both p < 0.05). These results suggested that chronic SNS not only improved the visceral sensitivity and autonomic dysfunction but also decreased the expression of TRPV1 in the spinal cord-gut tissue in IBS-D rats. ConclusionChronic SNS was found to have an inhibitory effect on visceral hypersensitivity in IBS-D rats, providing experimental evidence for its potential clinical application in IBS.

Simulation study of hydrogen sulfide removal in underground gas storage converted from the multilayered sour gas field

A simulation study was carried out to investigate the temporal evolution of H2S in the Huangcaoxia underground gas storage (UGS), which is converted from a depleted sulfur-containing gas field. Based on the rock and fluid properties of the Huangcaoxia gas field, a multilayered model was built. The upper layer Jia-2 contains a high concentration of H2S (27.2 g/m3), and the lower layer Jia-1 contains a low concentration of H2S (14.0 mg/m3). There is also a low-permeability interlayer between Jia-1 and Jia-2. The multi-component fluid characterizations for Jia-1 and Jia-2 were implemented separately using the Peng-Robinson equation of state in order to perform the compositional simulation. The H2S concentration gradually increased in a single cycle and peaked at the end of the production season. The peak H2S concentration in each cycle showed a decreasing trend when the recovery factor (RF) of the gas field was lower than 70%. When the RF was above 70%, the peak H2S concentration increased first and then decreased. A higher reservoir RF, a higher maximum working pressure, and a higher working gas ratio will lead to a higher H2S removal efficiency. Similar to developing multi-layered petroleum fields, the operation of multilayered gas storage can also be divided into multi-layer commingled operation and independent operation for different layers. When the two layers are combined to build the storage, the sweet gas produced from Jia-1 can spontaneously mix with the sour gas produced from Jia-2 within the wellbore, which can significantly reduce the overall H2S concentration in the wellstream. When the working gas volume is set constant, the allocation ratio between the two layers has little effect on the H2S removal. After nine cycles, the produced gas’s H2S concentration can be lowered to 20 mg/m3. Our study recommends combining the Jia-2 and Jia-1 layers to build the Huangcaoxia underground gas storage. This plan can quickly reduce the H2S concentration of the produced gas to 20 mg/m3, thus meeting the gas export standards as well as the HSE (Health, Safety, and Environment) requirements in the field. This study helps the engineers understand the H2S removal for sulfur-containing UGS as well as provides technical guidelines for converting other multilayered sour gas fields into underground storage sites.