Internal Pressure Research Articles

Improving Human Resource Management in Increasingly Fast-Growing Businesses in Turbulent Times

Abstract The economy is currently experiencing developing conceptual instability and a flurry of views. This structure imposes external demands on businesses and, most importantly, on the people who operate as the enterprise’s main engine. The company’s top management has the primary responsibility for easing internal decision-making factors that are causing pressures to escalate. If this doesn’t happen, external pressures may become exponential internal pressures that ultimately lead to the company’s destruction as it finds itself at the cross-point of the pressures. The working perspective of the irrational and the bidirectional hierarchical relationships, as well as the interactions between technological evolution and human resource management, are all covered in this paper’s 360-degree view of a company’s productivity ecosystem. Additionally, we try to identify certain potential standard traps that might have an impact on the company’s medium- and long-term viability as well as short-term productivity.

A Minimally Invasive Robotic Tissue Palpation Device.

Robot-assisted minimally invasive surgery remains limited by the absence of haptic feedback, which surgeons routinely rely on to assess tissue stiffness. This limitation hinders surgeons' ability to identify and treat abnormal tissues, such as tumors, during robotic surgery. To address this challenge, we developed a robotic tissue palpation device capable of rapidly and non-invasively quantifying the stiffness of soft tissues, allowing surgeons to make objective and data-driven decisions during minimally invasive procedures. We evaluated the effectiveness of our device by measuring the stiffness of phantoms as well as lung, heart, liver, and skin tissues obtained from both rats and swine. Results demonstrated that our device can accurately determine tissue stiffness and identify tumor mimics. Specifically, in swine lung, we determined elastic modulus (E) values of 9.1 ± 2.3, 16.8 ± 1.8, and 26.0 ± 3.6 kPa under different internal pressure of the lungs (PIP) of 2, 25, and 45 cmH2O, respectively. Using our device, we successfully located a 2-cm tumor mimic embedded at a depth of 5 mm in the lung subpleural region. Additionally, we measured E values of 33.0 ± 5.4, 19.2 ± 2.2, 33.5 ± 8.2, and 22.6 ± 6.0 kPa for swine heart, liver, abdominal skin, and muscle, respectively, which closely matched existing literature data. Results suggest that our robotic palpation device can be utilized during surgery, either as a stand-alone or additional tool integrated into existing robotic surgical systems, to enhance treatment outcomes by enabling accurate intraoperative identification of abnormal tissue.

Comparative analysis of experimental and simulation results of composite circular tube

Abstract In this work, the internal pressure of the composite pipe is analysed and studied when transporting liquid or gas. The quasi-static hydraulic test is designed to simulate the internal pressure of the composite pipe. By using the ABAQUS finite element method, a numerical model of the composite pipe under hydraulic load is established. The strain curves and final failure modes of the test and simulation are compared to verify the feasibility of the finite element method model. Finally, the damage mechanism of the composite tube is analysed according to the numerical model, and it is found that the carbon fibre composite material has an important effect on the bearing capacity of the composite tube.

Lessons learned in migrating from one commercial genetics decision-support tool to another: Assessment of data integrity and utilization readiness.

e23232 Background: Rapid advancements in health information technology have greatly influenced how clinicians engage with patient health data. In the context of clinical genetics, the electronic health record (EHR) often contains a wide array of data to identify patients at elevated risk for hereditary cancer syndromes. However, these data often exist in multiple forms and disparate locations, which in the presence of numerous commercial EHR solutions, results in significant variations in how institutions codify genetic data. Furthermore, within an institution, there is often internal pressure to migrate from one support tool to another, necessitating a focus on data integrity during such a transition. Methods: Fred Hutchinson Cancer Center (Fred Hutch) is a large academic cancer care center associated with the University of Washington. Between July and December 2023, the Fred Hutch Clinical Cancer Genetics and Genetic Counseling Service migrated their family history database from commercial pedigree software, Progeny, to another commercial pedigree and decision-support tool, CancerIQ. Following completion of the data migration on more than 13,000 patient records, study team planned to review a total of 500 randomly selected patient charts in both support tools. Each chart was reviewed to determine: (1) the presence of genetic intake information, (2) the presence and results of genetic testing, if available, and (3) whether the patient met National Comprehensive Cancer Network (NCCN) criteria for testing. A chart was noted to be concordant between the two support tools if there was agreement in all three of the above. Results: So far, a total of 240 patient charts were reviewed between the two support tools. Of these, 226 (94.2%) were noted to be fully concordant. Of the 14 charts that were noted to be discordant, the distribution of the discordant data was: 5 charts differed on whether genetic testing had been ordered, 5 charts differed on the results of the testing (often omitting one or more variants), and 4 differed on whether the patient met NCCN criteria for testing. Conclusions: At our institution, there was high data integrity following migration from one commercial and pedigree-generating software solution to another. While these results can ease clinician concerns following such support tools transitions, it also highlights areas for improvement in how family and patient genetic data is recorded.

THERMODYNAMIC PROPERTIES OF TERNARY LIQUID MIXTURE OF TOCOPHEROL ACETATE WITH CHLOROFORM AND DIETHYL ETHER AT 293 K

The reported study, measured the ultrasonic velocity (u), density (ρ) and viscosity (η) of ternary liquid mixtures of α-Tocopherol acetate with chloroform and diethyl ether in the concentration range (0 to 0.1 M) at 293K. These experimental parameters can be used to calculate various thermodynamic parameters like free volume (Vf), internal pressure (πin), Vander-Wall Constant (b) and Gibbs free energy (∆G*) etc. to identify the strength of molecular interaction. The results so obtained support the formation of complex structure and molecular aggregation through intermolecular hydrogen bonding in the ternary liquid system of α -Tocopherol acetate with chloroform and diethyl ether.

Between Tradition and Pragmatism: Challenges for Latin America amid the Russia–Ukraine War

This article explores Latin America's response to the Russia–Ukraine War by navigating the delicate balance between tradition and pragmatism. Historically championing self‐determination and non‐intervention, the region faces challenges in coordinating responses due to ideological divisions. Analysing reactions from Brazil, Mexico, Nicaragua and Venezuela, the study reveals various responses, ranging from diplomatic neutrality to outright support. Economic dependencies, power dynamics and domestic priorities influence approaches. As Latin America struggles with internal challenges and external pressures, the study advocates a nuanced understanding of the role of the region in the evolving international order, emphasising the need for cohesive diplomatic strategies.

Considerations for the structural design of wind turbine towers: A practical application

AbstractAiming to achieve efficient structural performance, this article presents a methodology for the design of the shell structure and dimensioning of the connections of an S355J2 tubular steel tower with a height of 80 m, compatible with a SWT‐2.3‐93 wind turbine. The tower is made up of three segments, interconnected by flanged connections made of high‐strength steel. The analysis considers various load cases, taking into account stress and resistance in different directions, as well as designing connections using Petersen's theory, according to maximum strength and fatigue criteria. The results indicate that the circumferential stresses are nearly negligible compared with the resistant stresses, while the shear stress is significantly higher at the base due to the torsional moment. Meridional stress determines the stability of the structure, requiring consideration of internal pressure for safety. Maximum stress values range from 135.00 to 168.47 MPa, depending on the location along the tower height. Flanged connections meet the strength and fatigue criteria, with the first flange enduring 63.0% of the fatigue effect and the second, 39.7%. Therefore, the results provide reliable information and methodologies for tower design, contributing to the practical and efficient development of these structures.

Enhancing Mesopore Volume and Thermal Insulation of Silica Aerogel via Ambient Pressure Drying-Assisted Foaming Method.

Ambient pressure drying (APD) of silica aerogels has emerged as an attractive method adapting to large-scale production. Spring-back is a unique phenomenon during APD of silica aerogels with volume expansion after its shrinkage under capillary force. We attribute the intense spring-back at elevated drying temperatures to a dense structure formed on the surface and the formation of positive internal pressure. Furthermore, an APD-assisted foaming method with an in situ introduction of NH4HCO3 was proposed. NH4HCO3 decomposing at drying temperatures hastened the emergence of positive pressure, thereby increasing the expansion volume. Compared to the previous method, the porosity of silica aerogel increased from 82.2% to 92.6%, and mesopore volume from 1.79 cm3 g-1 to 4.54 cm3 g-1. By adjusting the amount of the silicon source, silica aerogels prepared by the APD-assisted foaming method generated higher volume expansion and lower thermal conductivity. After calcination to remove undecomposed ammonium salts, the hydrophobic silica aerogel with a density of 0.112 g cm-3 reached a mesopore volume of 5.07 cm3 g-1 and a thermal conductivity of 18.9 mW m-1·K-1. This strategy not only improves the thermal insulation properties, but also offers a significant advancement in tailoring silica aerogels with specific porosity and mesopore volume for various applications.

Promoting Sustainable Development of Organizations: Performance Pressure, Workplace Fun, and Employee Ambidextrous Innovation

In the context of an economic downturn, organizations need to continuously improve their performance requirements for employees, and in the macro environment of intensified competition, organizations need to continuously motivate employees to innovate in order to seize development opportunities. Flexibly adjusting to the internal pressure of an organization while ensuring organizational vitality can promote employee adaptive growth and achieve sustainable development in the organization. However, the impact of performance pressure on employee ambidextrous innovation is currently unknown. Based on this, this article explores the positive effects of performance pressure in influencing employee ambidextrous innovation through job involvement from the perspective of Affective Events Theory and uses workplace fun as a moderating variable in order to analyze the internal logic of long-term motivation for employee ambidextrous innovation in organizations. This article conducted a survey and analysis of 362 in-service employees in enterprises and institutions and found the following: (1) performance pressure has a significant positive impact on employee ambidextrous innovation; (2) job involvement plays a partial mediating role between performance pressure and exploratory innovation; (3) workplace fun has a moderating effect on the relationship between job involvement and exploitative innovation, and the higher the level of workplace fun, the stronger the positive impact of job involvement on exploitative innovation.

Numerical Analysis of Functionally Graded Material (FGM) Axisymmetric Cylinder under Transient Thermal Load and Variable Internal Pressure

Numerical Analysis of Functionally Graded Material (FGM) Axisymmetric Cylinder under Transient Thermal Load and Variable Internal Pressure

Pressure resistance characterisation of vascular networks embedded in carbon composites for high energy physics applications

In state-of-the-art tracking detectors, lightweight carbon composite structures support the pixel or micro-strip sensors and provide the main thermal path between the silicon and a network of metallic or plastic pipes containing a cooling fluid. Despite the good results obtained with this design approach, the challenges associated with future high energy physics (HEP) experiments demand even lighter and more efficient technologies. In this regard, replacing the existing piping with a network of channels directly embedded in the composite laminates represents a promising solution to improve the thermal coupling, which also offers additional gains in terms of mass and thermo-elastic stability.While some research has been devoted to assessing the mechanical and thermal performance of such laminates, limited information about their resistance to internal pressure is currently available in the literature. This lack of data constitutes an important obstacle for the use of vascular networks in future HEP applications, which the present paper aims to address.Experimental methods were used to investigate the pressure resistance of channels embedded in carbon composite laminates. Modified poly (lactic) acid (PLA) preforms were embedded in carbon-fibre epoxy laminates. A post-cure vaporization technique removed the PLA, thus producing plates with longitudinal channels. Destructive tests were conducted to determine the burst pressure of the plates depending on the lay-up and the cross-section geometry of the channels. Both circular and oblong channels were evaluated, and various reinforcement techniques were explored to enhance the pressure resistance of the laminates. Micro-graphic examinations and X-ray micro-computed tomography were employed to gain a better understanding of the microstructure and the failure mechanisms of the plates.Plates with circular channels measuring 1.75 mm in diameter, embedded in [0/90/0]S laminates and reinforced with 2 mm lay length fuzzy carbon fibre over-braids, achieved burst pressures exceeding 45 MPa. This result, which is approximately an order of magnitude greater than that obtained for the equivalent non-reinforced laminates, demonstrates the enormous potential of this technology for future particle detectors.

Post-buckling behavior of variable-arc-length elastica pipe conveying fluid including effects of self-weight and pressure variation

This paper investigated the post-buckling behaviors of a variable-arc-length (VAL) elastica pipe caused by internal transporting fluid motion, accounting for the effects of the self-weight and variation of internal fluid pressure. Both weak-form and strong-form formulations of the VAL elastica pipe were developed. The weak-form formulation was derived by the virtual work principle, and later solved using the nonlinear finite element method (FEM). The strong-form formulation was derived using equilibrium of the force and moment equations, the geometrical relationship of the differential pipe segment, and the energy conservation of the transported fluid. Because of the large displacement analysis, the variation in the internal pressure inside the pipe was considered, which was taken into account by energy conservation based on the Bernoulli principle. Then, the set of nonlinear governing first-order differential equations, corresponding to the two-point boundary value problem, was conveniently solved using the shooting optimization method (SOM). The numerical results obtained from the presented FEM and SOM analyses independently verified each other, with good agreement between these two methods. The parametric study considered the effects of gravity load (pipe and fluid self-weights) and internal fluid pressure on the post-buckling characteristics of the VAL pipe. The numerical results showed that without the pipe and internal fluid weights, the transporting fluid exerted an axial compressive force on the pipe, causing post-buckling phenomena. Beyond the critical state, the support rotation and the length of the VAL pipe increased as the internal fluid velocity decreased. Finally, by including the effect of self-weight, the mode exchange of the odd buckling modes (1st and 3rd modes) was found from the load-displacement path.

Limit state equation and failure pressure prediction model of pipeline with complex loading

Assessing failure pressure is critical in determining pipeline integrity. Current research primarily concerns the buckling performance of pressurized pipelines subjected to a bending load or axial compression force, with some also looking at the failure pressure of corroded pipelines. However, there is currently a lack of limit state models for pressurized pipelines with bending moments and axial forces. In this study, based on the unified yield criterion, we propose a limit state equation for steel pipes under various loads. The most common operating loads on buried pipelines are bending moment, internal pressure, and axial force. The proposed limit state equation for intact pipelines is based on a three-dimensional pipeline stress model with complex load coupling. Using failure data, we investigate the applicability of various yield criteria in assessing the failure pressure of pipelines with complex loads. We show that the evaluation model can be effectively used as a theoretical solution for assessing the failure pressure in such circumstances and for selecting appropriate yield criteria based on load condition differences.

High-energy computed tomography for inspection and monitoring of flexible riser

Flexible risers have been widely used in the offshore oil and gas industry and have many applications, such as production, gas lifting, or gas and water injection. The structure comprises several metal and polymer layers, which allow it to withstand a sizeable bending curve and high internal pressure. Therefore, guaranteeing the integrity of flexible risers throughout their useful life is extremely important. It requires developing and applying effective inspection and monitoring techniques, particularly emphasizing the tensile armor layers. This work evaluated the ability of the High-Energy Computed Tomography (CT) Technique to detect internal defects such as cracks, breaks, and fissures in the riser layers. A flexible riser sample of approximately 2 m in length and 281 mm in external diameter was scanned using a tomography system consisting of a 6 MeV Betatron and a set of 14-bit A-Si digital detectors. The images were acquired in 360° with angular steps of 2°. After acquisition, the images were reconstructed, and 3D models were built for qualitative and quantitative evaluation. Through the segmentation process, the metal layers of the flexible riser could be analyzed individually. Defects were found in the tensile armor layers, indicating ruptures and cracks and the onset of pitting. The results strongly suggest that computed tomography can be used as a non-destructive technique for inspecting flexible risers, with good efficiency in detecting defects, and that its application can be extended to field tests.

Probing thermodynamics of radiogenic helium and defects in δ-plutonium alloys and interactions with adsorbed environmental gases

Differential scanning calorimetry coupled with simultaneous evolved gas analysis (DSC-EGA) on aged δ-Pu samples shows that most radiogenic helium remains trapped within the Pu matrix at temperatures very close to, or slightly above, the melting temperature. Our results indicate that helium release from 50-year-old δ-Pu occurs as a burst just below the melting temperature (>0.994 Tm), with subsequent pressure oscillations as temperature increases. Subordinate quantities of H2 were also released along with helium. The helium emission tails off and ceases above ∼720 – 750°C. In a δ-Pu alloy aged 6 years, the initial helium burst occurs slightly above melting (∼1.015 – 1.042 Tm), with a discrete, larger helium spike occurring between 670 and 686°C. The proximity of helium release to the liquidus transition presented challenges in the deconvolution of overlapping process enthalpies, the liquidus endotherm, and the exotherm resulting from bubble collapse, annealing and gas expulsion. Helium’s strong affinity for vacancy binding in a 2He-vac configuration is predicted by Density Functional Theory (DFT) modeling. The measured stored energy associated with the He release events in a 50-year-old δ alloy is on the order of ∼10–11 J/g, which is significantly higher than stored energies measured in the sub-solidus regimes (∼2 J/g) that are related to the solid-state annealing of processing- and radiation-induced defects. This implies that aged δ Pu alloys have a remarkable resilience to accommodate the lattice strain produced by the internal pressure of the helium bubbles and provides further insight into the thermodynamic behavior of aged δ Pu.

Mechanical Modeling of Viscous Fluid Damper with Temperature and Pressure Coupling Effects

During long-duration dynamic loads, such as wind loads or seismic effects, the internal temperature and pressure of a damping cylinder escalate rapidly, which induce shifts in the mechanical attributes of viscous fluid dampers (VFDs). This study investigated the mechanical performance of VFD considering the coupling effects of temperature and pressure under long-duration loads. First, we analyzed the mechanical and energy-dissipation performances of the dampers based on the dynamic mechanical tests considering different loading frequencies, displacement amplitude, and loading cycles. The experimental results indicated that both temperature and pressure influenced the output of the dampers, and in the sealed environment of the damper pip, temperature and pressure exerted mutual influence. Furthermore, the relationship between the damping coefficient and temperature–pressure coupling effects was obtained. Subsequently, an improved mathematical model for the mechanical performance of a gap-type VFD was proposed by considering the macroscopic energy balance of the entire fluid within the damper. Finally, the accuracy of the mathematical model for VFD under long-duration dynamic loads was validated by comparing the computational results with the experimental data.

Research on bearing capacity and stability of deep-water novel combined wellhead based on experimental methods

The combined wellhead has the advantage of high bearing capacity and broad prospects for application in the construction of deep water surface wells; therefore, it is important to conduct relevant research to guide the construction of combined wellheads. The aim of this paper is to study the mechanical characteristics of the combined wellhead in the longitudinal direction and establish the method for real-time calculation of the bearing capacity of the combined wellhead taking into account the effects of installation. The variations of external wall pressure and internal soil pressure during installation and the waiting process of the combined wellhead were investigated by indoor experiments. The installation efficiency of the combined wellhead at different negative pressure conditions was also compared. The experimental results show that the pressure on the outer wall of the combined wellhead facility gradually increases as the depth of the combined wellhead facility increases, and the closer it is to the bottom, the greater the soil pressure. The pressure on the inner soil will increase rapidly during the installation process to almost the same level, while the pressure on the outer soil will increase slightly. During the waiting process of the combined wellhead, as the waiting time increases, the soil damaged during the installation process gradually recovers, and the external wall pressure gradually rises. Moreover, the pressure on the outer wall gradually increases, the pressure on the inner soil decreases slightly leveling off within about 24 h. An appropriate increase in suction pressure facilitates the installation of the combined wellhead, and approximately 2.0 L/min is the optimal option for installation. The computational model developed in this paper and the experimental measurements corroborate each other. These combined wellheads significantly improve the stability of deep water soft-soil well construction and provide a theoretical benchmark for developing oil, gas and hydration in deep water.

A Review Article on Fatigue Life Estimation of Miter Bend

The Efficiency of the piping system largely relies upon bends used to connect pipes. The piping system is at the highest risk due to stress concentrations at abrupt cross-sectional change, large support less valves, vibrations, and lack of the assessment of fatigue failure. Bends undergo different combine loads involving internal pressure, in plane cyclic loading, out of plane cyclic loading, dead weight along with different thermal conditions. Compared to straight pipe miter bend has more complex mechanical behavior and critical stress-strain locations due to its asymmetric shape and hence miter bend undergoes plastic failure in the form of collapse, ratcheting, and fatigue that leads to component failure at the end. This paper presents review for behavior of miter bend considering important fracture mechanics parameters such as limit and collapse load, local wall thinning, ratcheting, creep, and their effects on fatigue life. The review also tabulates all fatigue life equations used by researchers for predicting fatigue life. Topics for further research on miter bends such as out of plane loading, vibration induced fatigue and creep are also noted.

Combined effects of ignition position and hydrogen ratio on vented CH4/H2/air explosions

Experiments on the effects of ignition position and hydrogen ratio (χ) on the explosions of CH4/H2/air mixtures were experimentally investigated in a vented cylindrical vessel. Relevant experiments were conducted utilizing ignition sources situated at the rear (rear ignition), the center of the vessel (central ignition), or near the vent (front ignition) with χ varying from 0 to 1.0. Two types of cellular structures on the flame surface, owing to the diffusional-thermal instability and acoustically enhanced combustion, respectively, were observed, and the latter resulted in acoustic oscillations of the overpressure within the vessel and a unique overpressure peak p2 with amplitude sensitive to both ignition position and χ. The effects of ignition position and χ on the build-up of the internal pressure were not significant when χ ≤ 0.15. The maximum explosion overpressure in the vessel (pmax) under the explosions of rear and central ignitions (RI and CI) increased monotonically as χ was increased from 0.3 to 1.0, but a nonmonotonic trend was found in the explosions of front ignition (FI). CI could be regarded as the worst-case scenario when 0.45≤χ ≤ 1.0 except for χ = 0.7, because FI resulted in the highest pmax at χ = 0.7. A pressure peak outside the vent (pext) caused by the combustion expansion of the combustible cloud could be distinguished when χ ≥ 0.45 in the explosions of RI and CI. The amplitude of pext increased with an increase in χ. Rear ignition always led to the highest pext when χ > 0.6.

Analysis of load carrying performance for glass fiber reinforced thermoplastic composite pipe under different in-service conditions

Fiber reinforced thermoplastic composite pipe (FRTP) has advantages over traditional metallic counterparts for oil and gas transportation. During in-service the pipe is subjected to different mechanical loads including internal pressure, torsion, and bending. In this work, a special type of continuous glass fiber reinforced thermoplastic composite pipe (DN150-6.4 MPa) is analyzed by finite element method (FEM) under various complex service-in conditions. Stress and strain are investigated for different layers of FRTP to determine the extreme load capacity. Experimental analysis is conducted to validate proposed method. Combining the results from FEM and test, it is concluded that the ultimate internal pressure (burst pressure) of FRTP is 61.7 MPa, the ultimate axial tensile displacement is 66.4 mm, the maximum torsion angle is 71.5°, and the minimum bending radius 978.9 mm. Under different working conditions, the mechanical properties of the FRTP are still surplus under the given load. For the good agreement with experimental data, the FEM modeling can be guide for practical application of FRTP.