Increase In Pressure Research Articles

Сравнение мини-перкутанной нефролитотомии с супер-мини-перкутанной нефролитотомией: когортное исследование

Introduction. Over the past 20 years mini-percutaneous nephrolithotomy (mini-PCNL) is remaining an effective method non inferior to standard PCNL with lower rates of serious complication related to bigger nephrotomy tract size like bleeding. However, in comparison to standard PCNL miniPCNL diminishes visualization, leads to increase of intrarenal pressure (IRP), difficulties in stone fragments evacuation, and longer operative time. In 2016 Zeng has developed an innovative aspiration sheath. Novel modification of miniPCNL with suction was called superminiPCNL (SMP) [1]. We have modified this aspiration sheath. There is the lack of data regarding efficacy and safety of this innovative method. Objectives. The aim of the study is to compare efficacy and safety of miniPCNL with SMP using an innovative suction sheath in the treatment of kidney stone disease. Material and methods. Between September 2021 and March 2023, 140 underwent PCNL. Patient were divided into 2 groups 1:1, 70 patients in each group. MiniPCNL was used in control group, SMP using aspiration suction sheath – in intervention group. Operative time, stone-free rate (SFR), bleeding, postoperative complications were compared between two groups. Results. SFR didn`t significantly differ between the groups and was 91.3% and 98.4% respectively (p = 0.117). Mean operative time was less in SMP group with a mean shortening of the procedural time of 13 min (p < 0.001). Hemoglobin drop was comparable between the groups (p = 0.73). Fever was significantly less frequent in SMP group, 11.6% in miniPCNL vs. 1.6% in SMP group (p = 0.042). There were no serious complications (Clavien III and IV) in any group. Discussion. PSMP is not inferior to miniPCNL in terms of efficy and safety. Moreover, it leads to shorter operative ime, decreases complication rates, and thus is a preferable method of renal stone treatment. Keywords: Kidney stone disease, percutaneous nephrolithotomy, surgery, supermini-PCNL.

Study of Mechanical Properties of Different Hydrate Reservoirs

Based on the triaxial shear tests of mud sediments in the South China Sea, mud chalk-type sediments in the South China Sea, and sandy sediments in the Nankai Trough, Japan, at different hydrate saturation and enclosing pressures, the stress-strain relationships of hydrate-bearing clays, mud chalk-type soils, and sandy soils were analyzed. The test results show that:(1)The stress-strain curves of the South China Sea clay sediments show three stages of elasticity, plastic deformation and strain hardening, which are significantly different from those of the hydrate-free clays; the stress-strain relationships of the hydrate-containing clays before and after hydrate decomposition are significantly different, and the undrained strength of the clays decreases by up to 50% after hydrate decomposition compared with that before hydrate decomposition; the above results indicate that the presence of hydrate enhances the linkage or cementation between the clay particles. The above results indicate that the presence of hydrate enhances the linkage or cementation between the clay particles.(2)For the mechanical properties of the hydrate specimens of the muddy chalky sand type in the South China Sea, the hydrate endowment, effective stresses and pore pressures all have some influence on the strength and deformation properties. The inclusion of hydrate in the pore space enhances the shear expansion characteristics of the sediments. For the effect of effective stress on the mechanical properties of hydrate sediments, the increase of effective peritectic pressure reduces the strain softening properties of hydrate sediments. The destructive strength of the sediments increases with the increase of effective confining pressure.(3)For the hydrate specimens in the Nankai Trough of Japan under the same effective circumferential pressure conditions, with the increase of hydrate saturation, the stress-strain law of the sediments showed a tendency to transform from strain hardening to strain softening, and the morphology of sandy sediment axial strain-lateral strain curves was controlled by the factors of hydrate saturation, and the absolute value of the slope of the curves expressed the rule of change of the tangent Poisson's ratio.

Evaluation of the use of Antihypertensive Drugs in Outpatient Hypertension Patients at the Lasinrang Regional General Hospital, Pinrang Regency in 2023

Hypertension is a complex condition in which blood pressure is permanently above normal. Hypertension is an increase in systolic blood pressure of more than equal to 140 mmHg and diastolic more than equal to 90 mmHg. This study aims to identify how antihypertensive drugs are used in hypertensive patients at the Lasinrang Regional General Hospital, Pinrang Regency. This study is a non-experimental research with a descriptive design taken retrospectively. The sample in this study is all outpatients with a diagnosis of hypertension at the Lasinrang Regional General Hospital in 2023. The sampling technique used is purposive sampling. The sample of this study is medical record data on hypertension patients in 2023 which is adjusted to the inclusion criteria. The results of the study showed that from 83 samples consisting of 50 women and 33 men, all of which met the inclusion and exclusion criteria, and showed a prevalence of age that dominated around 58-65 years (49,40%). In the evaluation of drug use, outpatient hypertension patients at the Lasinrang Regional General Hospital, Pinrang Regency had an indication accuracy of 100%, 100% drug accuracy, and 100% dose accuracy.

ANALYSIS OF SOCIAL AND ECONOMIC DEVELOPMENT OF THE VOLOGDA REGION

The increase in sanctions pressure had a significant impact on the Vologda Region, which is one of the most economically affected regions of the Northwestern Federal District, due to its geographical location and significant orientation of the economy to the markets of unfriendly countries. The purpose of the study is to analyze the socio-economic development of the Vologda Region based on statistical data. It was revealed that the rate of socio-economic development of the Vologda Region is below the average values of the Northwestern Federal District, the main problem hindering the socio-economic development of the region is the low rate of diversification of the economy, lack of investment in innovation, lack of qualified personnel.

THE EU RESPONSE TO THE MASSIVE INFLUX OF DISPLACED PERSONS FROM UKRAINE IN 2022

Russia has been conducting military action against Ukraine since 24 February 2022, in violation of the prohibition on the threat or use of violence against the territorial integrity or independence of any state, which is one of the fundamental principles of modern international law. The Russian aggression has resulted in a sharp increase in migratory pressure on the EU. As a result, the Union launched a special temporary protection procedure for the first time in its history. As temporary protection is one of the instruments of the Common European Asylum System, this article begins with an analysis of its nature within EU asylum policy. The article’s next research question and objective relate directly to the EU’s response to the Russian act of aggression. They are relevant for clarifying the political context of the activation of temporary protection and, simultaneously, establishing the circumstances necessary for the activation of temporary protection in the light of Council Directive 2001/55/EC. This Directive and Council Implementing Decision 2022/382 determine the normative construction of the temporary protection 2022. These elements are its duration, the categories of beneficiaries, and the beneficiaries’ entitlements, which result in obligations for Member States. The analysis of these issues will determine to what extent temporary protection is a viable and effective measure of international protection for displaced persons from Ukraine.

Numerical simulation of mechanical properties and damage process of carbon nanotube concrete under triaxial compression and splitting conditions

To investigate the mechanical properties and failure processes of carbon nanotube concrete, a three-dimensional meso-scale finite element model of concrete was constructed. Using ABAQUS software, numerical simulations were conducted on concrete samples with different carbon nanotube concentrations under triaxial compression and splitting conditions. The results indicate that under splitting conditions, the failure of the specimens initially occurs along the loading direction from both ends, with few cracks and slow propagation. Subsequently, the cracks rapidly expand, penetrating the entire specimen, leading to the formation of a macro-fracture surface with a crack aligned with the loading direction. This failure mode manifests as a straight crack. At the same loading rate, the tensile strength of the specimens with different carbon nanotube concentrations increases to varying degrees during splitting failure, with a maximum increase of 45.10% to 4.15 MPa. nder triaxial compression conditions, the main failure mode of the specimens exhibits shear failure characteristics. As the confining pressure gradually increases, the failure angle of the specimens enlarges. Under low confining pressure, there are fewer wing-shaped tensile cracks at the shear failure surface of the specimens. As the confining pressure increases, irregular shear failures and multiple shear planes appear in the specimens, resulting in more complex failure modes. For specimens with the same carbon nanotube concentration, the triaxial compressive strength of carbon nanotube concrete specimens increases with increasing confining pressure. The triaxial compressive strengths of the specimens under confining pressures of 5 MPa, 10 MPa, 15 MPa, and 20 MPa are 90.48 MPa, 122.72 MPa, 137.22 MPa, and 172.65 MPa, with strength increases of 35.63%, 51.66%, and 90.81%, respectively.

Study on corrosion of Cr-containing steel under different CO2 partial pressures at high temperatures

To achieve the goal of "carbon peak " and "carbon neutral", CO2 injection in oilfields has become a major trend, but it also comes with the risk of CO2 corrosion on the pipe strings, particularly under high temperature and pressure (HTHP). This study utilizes a laboratory-made HTHP reactor to conduct corrosion tests on three commonly used chromium-containing steels (13Cr, S13Cr, and 25Cr) in oil fields under conditions of 200 °C and a total pressure of 70 MPa, with CO2 partial pressures of 10 MPa, 25 MPa, and 45 MPa respectively. The corrosion components, phase structure and three-dimensional morphology of the specimens are analyzed by SEM/EDS and other microscopic characterization means. Additionally, the critical safety factor after the casing pitting corrosion is calculated. The results indicates that under experimental conditions, the uniform corrosion rate of 13Cr decreases with the increase of CO2 partial pressure, while the uniform corrosion rate of S13Cr and 25Cr initially decreases and then increases with the rise of CO2 partial pressure. Moreover, with the increase of CO2 partial pressure, the pitting corrosion rate of specimens decreases. Under the action of Cl− in the medium solution, the passivation film on the surface of Cr-containing steel is damaged. The severity of pitting corrosion among the materials follows the order: 25Cr > 13Cr > S13Cr. The main elements responsible for severe corrosion are oxygen (O) and sulfur (S). When the depth of the corrosion pit reaches 2.06 mm, the critical internal pressure safety factor of the casing is reached.

Theoretical Kinetics of Radical-Radical Reaction NH2ṄH + ṄH2 and Its Implications for Monomethylhydrazine Pyrolysis Mechanism.

Significant discrepancies were observed between the experiments and the simulations for ṄH2 time-histories in monomethylhydrazine pyrolysis with the robust mechanism proposed by Pascal and Catoire. The rate of formation analyses for ṄH2 indicated the significance of the reaction NH2ṄH + ṄH2 = H2NN + NH3, which has not been well-defined. In this study, ab initio calculations were performed for the theoretical description of the NH2ṄH + ṄH2 chemistry. Most stationary points on the potential energy surface were quantified at the CCSD(T)/CBS//M06-2X/aug-cc-pVTZ level, and the multireference methods were employed for barrier-less reaction and some transition states. The temperature- and pressure-dependent rate coefficients were determined using classical and microcanonical variational transition state theories. Four primary reaction channels were identified as competitive: 1) The H atom abstraction reaction yielding N2H2(T) + NH3, dominating at 1350-3000 K across the 0.001-100 atm pressure range. 2) The H atom abstraction reaction forming N2H2(S) + NH3, dominating at 800-1350 K and competing with the processes of chemical activation and collisional stabilization below 800 K. 3) The chemical-activated reaction resulting in H2NN(S) + NH3, dominating below 800 K at 0.001 atm. 4) The collisional-stabilized recombination reaction leading to N3H5, becoming significant as pressure increases and dominating below 600 and 650 K at 1 and 100 atm, respectively. The implications of newly calculated NH2ṄH + ṄH2 kinetics for the monomethylhydrazine pyrolysis mechanism were evaluated, and updates were implemented. Sensitivity analyses indicated the necessity of additional research efforts to comprehend the dynamics of CH3NH2 unimolecular and N2H2 + ṄH2 reaction systems. The rate coefficients presented in this study can be employed to develop the chemical kinetic model of nitryl-containing systems.

Operation optimization of large-scale natural gas pipeline networks based on intelligent algorithm

With the expansion of natural gas pipelines into larger networks, there is a growing concern regarding energy consumption in the operations of pipeline systems. However, the intricate network structure and hydraulic properties pose challenges for operation optimization. In this paper, a Mixed Integer Nonlinear Programming model is proposed to optimize the steady-state operation of natural gas pipeline network, aiming to minimize the energy consumption of compressor units. The model incorporates constraints related to flow direction, flow balance, pressure drop in pipeline sections, and pressure increase at compressor stations. To solve the complex nonlinear model efficiently, a stochastic optimization algorithm that integrates particle swarm optimization and high-fidelity simulation is proposed. The case study is conducted on a large-scale natural gas pipeline network consisting of forty-three pipeline sections and four compressor stations. The optimal operation scheme is calculated, and the outlet pressures of each compressor are determined. The results demonstrate that the stochastic optimization algorithm proposed in this paper can reduce energy consumption by 21.23 % at most and 19.77 % on average during pipeline operation, which can provide guidance for the operation management of large-scale natural gas pipeline network.

Threshold Determination for Effective Water Injection in Coal Seams: Insights from Numerical Simulation

Coal seam water injection is the most basic and effective dust control technology used on the coal mining face. Numerical simulations are helpful for predicting the humidity range of coal seam water injection. The results can provide guidance for the field design of coal seam water injection process parameters. In order to understand the influence of coal seam water injection pressure and water injection time on the coal seam wetting effect, this paper uses the Fluent 17.0 software system to study the process parameters of the coal seam water injection seepage process under different conditions. It is found that in the process of coal seam water injection, with the increase in water injection pressure and the prolongation of water injection time, there is a specific threshold value for the change in coal seam permeability. Only when the water injection pressure and time increase to the threshold value will the permeability of the coal seam be significantly enhanced and the wetting effect improved. The pressure threshold of the mine is 15 MPa–20 MPa, and the time threshold is the first 42 h.

Study on the Spontaneous Combustion Law of Coal Body around a Borehole Induced by Pre-extraction of Coalbed Methane.

To address the challenges associated with the high gas content, high pressure, and low permeability coefficient in deep coal seams, strategies such as infilling boreholes and increasing the negative pressure of extraction are commonly implemented to alleviate issues related to coalbed methane extraction. However, long-term mining pressure can lead to the development of cracks in the coal seam near the borehole, thereby creating air leakage channels, which could potentially impact the oxygen supply during the extraction process. This leads to secondary disasters such as the spontaneous combustion of coal and gas explosions, considerably impacting the life and health of underground workers. To solve this issue, a thermal-fluid-solid coupling model for the working surface was constructed based on numerical simulation software, taking into account the multimechanism coupling effect of coal seam gas. The laws of coal oxidation and spontaneous combustion induced by coalbed methane extraction around boreholes were studied. The variation laws of the oxygen concentration, coal temperature, and oxidation heating zone around the borehole under different extraction conditions were simulated and analyzed. The findings demonstrate that the negative extraction pressure enables the gas to penetrate the fracture zone of the borehole, leading to an increase in the oxygen consumption rate and coal temperature around the borehole with an increase in negative extraction pressure. The coal gas leakage surrounding the borehole reduces as the sealing depth increases, and both the heating rate of coal and oxygen volume fraction show a downward trend. The fitting relationship between the negative pressure of drainage, depth of sealing, and temperature change in the coal body surrounding the boreholes was identified. It was determined that the negative pressure of 13 kPa for borehole drainage and a sealing depth >18 m are the optimal extraction parameters. The range of the oxidation zone and the position of the boundary line under this parameter were predicted, and the position function of the dangerous area of oxidation heating was defined. The research results have remarkable implications for the coordinated prevention and control of gas and coal spontaneous combustion in coalbed methane predrainage boreholes, as well as for efficient prevention and control of CO in on-site gas extraction boreholes, thus ensuring efficient and safe gas extraction.

Intelligent Ureteral Stent Placeable via Standard Procedure for Kidney Pressure Telemetry: An Ex-Vivo Study.

This paper reports the first telemetric ureteral stent compatible with common placement procedure, enabling wireless sensing and detection of ureteral obstruction and resultant kidney swelling known as hydronephrosis at an early stage. This sensor-integrated "intelligent" ureteral stent is prototyped via the design and fabrication approaches that raise the practicality of the device and tested in a harvested swine kidney-ureter model ex vivo. Leveraging a polymeric double-J stent and micro-electro-mechanical systems technology, the intelligent stent is built by embedding micro pressure sensors and a radiofrequency antenna, forming a resonant circuit that enables wireless kidney pressure monitoring in an operating frequency of 40-50MHz. The stent device is entirely packaged with Parylene-C for both biocompatibility and electrical insulation of the device in order to function in the real environment including urine, an electrically conductive liquid. A comparison between the results measured in in-vitro and ex-vivo settings show a good match in the sensitivity to applied pressure. In particular, the ex-vivo test in the kidney-ureter model pressurized with artificial urine in a cycled manner demonstrates wireless pressure tracking with a response of 1.3kHz/mmHg, over pressures up to 37mmHg that well covers a range of pressure increase known for chronic obstruction. This testing is enabled by the prototype placement into the ex-vivo model using the standard stenting technique and tools without noticeable functional degradation or failures, showing potential compatibility of the device with today's clinical need as a ureteral stent.

Hydrostatic Pressure‐Tuning of Opto‐Electronic and Thermoelectric Properties Half‐Heusler Alloy RhTiP With DFT Analysis

ABSTRACTUtilizing DFT along with Boltzmann transport theory, the structural, elastic, electrical, optical, and thermoelectric properties of half‐Heusler compound RhTiP have been calculated in principle to examine the pressure effect in the range of 0–40 GPa. As pressure increases, the volume and normalized lattice parameter decreased. In addition to satisfying the Born stability criterion, which ensured the compound RhTiP “natural stability,” the zero pressure elastic constants and the pressure‐dependent elastic constants are positive up to 40 GPa. The band structure computations guarantee the semiconductor nature of RhTiP, as demonstrated by the presence of electronic band gap of 1.035 eV at zero pressure. Using the Voigt‐Reuss‐Hill (VRH) averaging scheme under pressure, we have determined the values of this compound's bulk modulus , shear modulus , Young's modulus , Pugh ratio , Poisson's ratio , and anisotropy factor . Because the bulk modulus responds linearly to pressure, the material's hardness increases as pressure rises. Additionally, under pressures up to 40 GPa, the optical characteristics of RhTiP, including their reflectivity, absorptivity, conductivity, dielectric constant, refractive index, and loss function, were assessed and discussed. Furthermore, the thermoelectric properties are also studied for the materials and supports the tunning of pressure. This study provides a gateway to how the optoelectronic and transport properties of cubic RhTiP could be tuned by employing external pressure.

Mechanical properties and dynamic compression behaviour of basalt/polypropylene fibre-reinforced high-strength concrete

Concrete is a typical brittle material. Although it has excellent compressive performance, it can be damaged by dynamic loads such as explosions and impacts due to its poor tensile strength and cracking susceptibility. In an attempt to improve the impact resistance of concrete, a ∅100 × 50 split Hopkinson pressure bar was used to carry out impact tests on high-strength concrete (HSC) specimens with different volume contents (0.1%, 0.3% and 0.5%) of basalt fibre (BF) or polypropylene fibre (PPF) under three different impact pressures. The compressive strength, splitting tensile strength, flexural strength and dynamic compression performance of BF/PPF-reinforced HSC (C60) were studied. With an increase in impact pressure, increasing the volume content of fibre significantly improved the impact resistance of the concrete, due to the crack resistance and bridging effects of the fibre. The BF and PPF were found to be sensitive to the strain rate. Within a certain range of strain rate, the relationship between peak stress and strain rate was positively correlated. Dynamic stress–strain curves of concretes with optimal dosages of BF and PPF were obtained through dynamic compression tests.

The preliminary design of emergency core cooling scheme and loss-of-coolant accident analysis for Tsinghua high flux reactor

This paper proposes the preliminary emergency core cooling scheme for Tsinghua High Flux Reactor. According to the thermohydraulic characteristics of high flux reactors, forced circulation needs to be maintained by emergency pumps in the early stage. When the decay power is low enough, natural circulation between core and the reactor pool is initiated to remove the residual core heat. The sources of safety injection are accumulators and reactor pool. Accumulator injection can ensure core safety in the early stage and reactor pool injection can maintain long time stable forced circulation. To avoid emptying the reactor pool, the waterproof zone needs to be built. The waterproof zone consists of reactor pool and several finite volume dry pools. All pipelines and equipment in the reactor coolant system are placed in the dry pools. Once break accident occurs, the dry pool where the break is located can collect the leaked coolant. With the increase of break back pressure, the break flow is restricted. The current scheme is modeled by Relap5 and different size breaks at four locations (namely core inlet, core outlet, primary heat exchanger inlet and main pump inlet) are assumed. According to the response characteristics of the scheme, the accident process can be divided into five stages: non-shutdown stage, high-injection stage, low-injection stage, stable forced circulation stage and natural circulation stage. Critical heat flux predicted by Sudo CHF correlations is adopted as the primary safety criterion. Through analysis, a success path is found to maintain core safety for a wide range of loss-of-coolant accident scenarios.

Asuhan Keperawatan Keluarga pada Ny. S dengan Gangguan Sistem Kardiovaskular : Hipertensi di Desa Kalibuntu RT 02 RW 03 Kecamatan Losari Kabupaten Brebes

Hypertension is still one of the problems that exist in the community today. Ordinary people know hypertension as high blood pressure because this disease has a high increase in blood pressure outside normal limits (Marbun and Hutapea 2022). The purpose of this writing is to be able to make and apply Family Nursing Care to Mrs S with Cardiovascular System Disorders: Hypertension in Kalibuntu Village Rt 02 Rw 03 Losari District, Brebes Regency. This writing method uses a descriptive method with a nursing process approach study. The results of nursing care Clients often feel dizzy and headache, the back of the head feels heavy. Pain in the nape of the neck. Pain increases during activity and decreases when resting. Pain like being cut into pieces. Pain in the nape of the neck. Pain scale 4 (moderate pain). Pain is intermittent. The client said he knew about hypertension, but did not know in detail about what causes hypertension, signs and symptoms of hypertension, and how to prevent and treat complaints. The nursing diagnoses raised are acute pain and knowledge deficit. Interventions are carried out based on SIKI and implementation based on interventions that have been designed. In the evaluation of the two diagnoses there is one resolved diagnosis, namely knowledge deficit, partially resolved diagnoses, namely acute pain. The results of nursing care have no gaps with theory. Writing i

Research on the Biogas Production Mechanism of Mudstone in the Qaidam Basin under Different CO2 Pressures.

Mudstone, a class of sedimentary rocks rich in organic matter, possesses considerable potential for biogas production. Mudstones possess a rich biological origin, which is conducive to refining the mechanisms and enrichment patterns of biogenic gas reservoirs. This has significant theoretical and practical implications for guiding the exploration and development of Quaternary mudstone gas reservoirs. Furthermore, the Qaidam Basin is an excellent place for the geological storage of CO2 due to its rich petroleum reservoir conditions. Experimental research on biogas production under diverse CO2 pressure-mudstone-microorganism-water interactions is conducted to determine the biogas production mechanism of mudstone under different CO2 pressures during sequestration circumstances. According to the results: (1) under supercritical carbon dioxide conditions, there is a slight initial increase in biogas production, followed by a gradual decrease. The periods and peaks of gas production vary among the different reaction groups. As carbon dioxide pressure increases, the gas production cycle lengthens significantly, while the gas yield declines. (2) Siderite and secondary carbonate minerals have increased in the mudstone's mineral fraction both before and after biogas production, while clay mineral groups have decreased. Specifically, there was a notable drop in chlorite and kaolinite. (3) Microorganism species in the system were analyzed, and the results showed that there was a gap in each microorganism's ability to adapt to its surroundings, and the diversity and quantity of bacteria declined with increasing pressure. After carbon dioxide was fluxed, there was a considerable shift in the pattern of biogas generation, which consequently had a major impact on the alterations in mineral fractions.

Energy features of CO2-cycles during oxygen combustion of methanol

The PURPOSE of the work is to determine the mass-flow characteristics of working substances and energy indicators of an installation based on a CO2 cycle with a two-stage pressure increase (Allam cycle) during oxygen combustion of methanol.METHODS. A research methodology is presented in which the mass-flow characteristics of working substances are determined based on the reactions of combustion and synthesis of methanol and electrolysis of water. These reactions are basic for ensuring operational processes in the installation. The method is based on the molar ratios of substances participating in reactions under stoichiometric conditions. Using the thermodynamic parameters of the cycle being implemented and at a given installation power, the consumption of the working fluid, the share of carbon dioxide renewal in the cycle, the amount of methanol produced in the synthesis unit, the amount of fresh methanol, the amount of hydrogen produced in the water electrolysis unit and the amount of oxygen are determined, necessary to ensure fuel combustion processes. At the same time, the amount of commercial hydrogen is determined. Electricity consumption for own needs is determined using regulatory methods and data from equipment manufacturers.RESULTS. The article shows that with similar values of thermal efficiency of CO2 cycles based on oxygen combustion of methane and methanol, the amount of carbon dioxide removed from the cycle for disposal is 11% less. It has been shown that a CO2 cycle operating on methanol is capable of producing commercial hydrogen simultaneously with electricity generation. The specific electricity consumption for hydrogen production is 22% less than for its production without combination with the CO2 cycle.

Numerical study of the effects of loading parameters on high-energy gas fracture propagation in layered rocks with peridynamics

The objective of this study is to investigate the influence of loading parameters on the propagation pattern of high-energy gas fractures in layered rock formations. To this end, a peridynamic model for brittle rock accounting for material heterogeneity was proposed. The ability of the model to simulate dynamic fractures was validated through laboratory experiments, and the homogeneity coefficient for the critical elongation rate was calibrated. On this basis, a numerical model of high-energy gas fracturing in layered rocks containing interfaces was constructed. Simulations were conducted to analyse high-energy gas fracturing from cylindrical intact boreholes and perforated boreholes under varying loading parameters. The results indicate that as the loading rate increases, the number of radial fractures surrounding the borehole gradually increases, whereas the influence of in-situ stress on fracture propagation diminishes. When the loading rate is fixed, both an increase in the peak pressure and a decrease in the decay rate are conducive to enhancing the propagation length of fractures. The propagation speed of fractures significantly decreases when they reach an interface but recovers after they penetrate it. Fractures tend to penetrate an interface when the angle of approach is closer to a right angle, and the direction of fracture propagation can be controlled through a perforation design. These findings provide valuable insights into the selection and optimization of loading parameters for reservoir stimulation via high-energy gas fracturing.

Catastrophe Information Characteristics and Prevention Measures of Water Inrush in Tunnel Approaching Fault with Different Water Pressure

In order to ensure the safety of the tunnel approaching the fault and prevent water inrush disasters, and then take reasonable protective measures, a fault-tunnel-surrounding rock is established by using a three-dimensional (3D) discrete element numerical analysis method, which takes into account the fluid-structure coupling effect. Based on the method of control variables, the catastrophe information characteristics of displacement and water pressure of the surrounding rock of the tunnel face and the corresponding characteristics of changes before the occurrence of water inrush disasters were studied under different fault water pressures during the excavation of the tunnel approaching the water-rich fault. The results show that, during excavation at the same step, displacement and its magnitude in the surrounding rock escalate as fault water pressure increases. The maximum pressure of the water in the surrounding rock is also constantly increasing. As tunnel excavation progresses, at constant fault water pressure, longer excavation distances result in greater axial displacement of the surrounding rock mass and increased water pressure at corresponding positions within the surrounding rock, leading to higher magnitude increases. As excavation proceeds, the displacement and water pressure in the surrounding rock and the increase of its amplitude continue to increase. Pre-reinforcement grouting techniques and pipe umbrella support systems that are very effective protective measures can be determined by a comprehensive approach integrating advanced geological forecasting methods, real-time water pressure detection, and the analysis of stress-strain and seepage pressure field variations in the surrounding rock mass.